Ukuphononongwa kwezaphuli-mthetho nokuzalana kwemixholo yenkangeleko kwincwadi ka L. K. Siwisa "Izimanga zalo mhlaba"
- Authors: Melane, Amanda Boniswa
- Date: 2006
- Subjects: Siwisa, L. K. -- Criticism and interpretation , Siwisa, L. K. Izimanga zalo mhlaba , Xhosa fiction -- History and criticism
- Language: Xhosa
- Type: Thesis , Masters , MA
- Identifier: vital:8471 , http://hdl.handle.net/10948/564 , http://hdl.handle.net/10948/d1011677 , Siwisa, L. K. -- Criticism and interpretation , Siwisa, L. K. Izimanga zalo mhlaba , Xhosa fiction -- History and criticism
- Description: Ubundlobongela buxhaphake okweentwala kubaThembu. Zininzi iindidi zobundlobongela ezithi ziqhubekeke apha ekuhlaleni. Abantu abathi bazibandakanye nobundlobongela, baphembelelwa ziimeko ezithile. Iimeko ezifana nokunqaba kwemisebenzi, izinga elinyukileyo lokusetyenziswa kweziyobisi nendlela athi umntu othile akhule ngayo. Ukuba ubani othile ukhule ngobusela, naye ulandela emkhondweni kanye abe lisela elibalaseleyo. Kwincwadi kaL. K. Siwisa ethi, “Izimanga zalomhlaba” kubhaqeka oku kulandelayo: Umntwana okhule ekhayeni lakhe kuetyenziswa iziyobisi naye wenza njalo akuba mkhulu. Imali eza ngobuqhinga nokuphela kwayo kuba lula. Ungumntu ebomini kufuneka utye ukubila kwebunzi lakho, uyeke ukufuna ukuvuna kodwa ungakhange ulime. Umntu kaloku uvuna loo nto athe wayilima. Apha ebomini zimisele ukwenza ubutyebi nelifa ngeli xesha usadla amazimba ukuze uphumelele. Xa ungumntu zimisele ukwanela, kule ndawo uMdali akubeke kuyo. Akufuneki ube ngumntu onentliziyo ende, unikwe isandla, wena ufune isandla kunye nengalo. Yonke le mikhwa ikukhokelela ekubeni ekugqibeleni wenze ubundlobongela. Ubundlobongela ke abubhatali koko busingisela kwantshabalala. Kula mabalana iyangqineka ngokuthi abonise iziphumo zobundlobongela ezifana nokuphulukana nobomi, ukuphelelwa zizinto zakho obunazo ngenxa yamaqhinga nobusela nokuphelela entolongweni. Kobu bundlobongela kukholisa ukubakho amaxhoba. Ngelishwa uninzi lwawo iba ngamabhinqa nabantwana.
- Full Text:
- Date Issued: 2006
- Authors: Melane, Amanda Boniswa
- Date: 2006
- Subjects: Siwisa, L. K. -- Criticism and interpretation , Siwisa, L. K. Izimanga zalo mhlaba , Xhosa fiction -- History and criticism
- Language: Xhosa
- Type: Thesis , Masters , MA
- Identifier: vital:8471 , http://hdl.handle.net/10948/564 , http://hdl.handle.net/10948/d1011677 , Siwisa, L. K. -- Criticism and interpretation , Siwisa, L. K. Izimanga zalo mhlaba , Xhosa fiction -- History and criticism
- Description: Ubundlobongela buxhaphake okweentwala kubaThembu. Zininzi iindidi zobundlobongela ezithi ziqhubekeke apha ekuhlaleni. Abantu abathi bazibandakanye nobundlobongela, baphembelelwa ziimeko ezithile. Iimeko ezifana nokunqaba kwemisebenzi, izinga elinyukileyo lokusetyenziswa kweziyobisi nendlela athi umntu othile akhule ngayo. Ukuba ubani othile ukhule ngobusela, naye ulandela emkhondweni kanye abe lisela elibalaseleyo. Kwincwadi kaL. K. Siwisa ethi, “Izimanga zalomhlaba” kubhaqeka oku kulandelayo: Umntwana okhule ekhayeni lakhe kuetyenziswa iziyobisi naye wenza njalo akuba mkhulu. Imali eza ngobuqhinga nokuphela kwayo kuba lula. Ungumntu ebomini kufuneka utye ukubila kwebunzi lakho, uyeke ukufuna ukuvuna kodwa ungakhange ulime. Umntu kaloku uvuna loo nto athe wayilima. Apha ebomini zimisele ukwenza ubutyebi nelifa ngeli xesha usadla amazimba ukuze uphumelele. Xa ungumntu zimisele ukwanela, kule ndawo uMdali akubeke kuyo. Akufuneki ube ngumntu onentliziyo ende, unikwe isandla, wena ufune isandla kunye nengalo. Yonke le mikhwa ikukhokelela ekubeni ekugqibeleni wenze ubundlobongela. Ubundlobongela ke abubhatali koko busingisela kwantshabalala. Kula mabalana iyangqineka ngokuthi abonise iziphumo zobundlobongela ezifana nokuphulukana nobomi, ukuphelelwa zizinto zakho obunazo ngenxa yamaqhinga nobusela nokuphelela entolongweni. Kobu bundlobongela kukholisa ukubakho amaxhoba. Ngelishwa uninzi lwawo iba ngamabhinqa nabantwana.
- Full Text:
- Date Issued: 2006
Ukuzotywa kwabalinganiswa ababhinqileyo abaziintloko kwiidrama zolwimi lwesiXhosa bezotywa ngababhali abasini sobuduna kwakunye nabo babhinqileyo
- Authors: Bukula, Andiswa
- Date: 2016
- Subjects: Xhosa literature -- Research Gender identity in literature , Gender nonconformity Women -- South Africa -- Drama
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/18431 , vital:28645
- Description: Eli phepha lithiywe “Ukuzotywa kwabalinganiswa ababhinqileyo, abazintloko kwidrama zolwimi lwesiXhosa, bezotywa ngababhali besini sobuduna nesini sobukhomokazi liza kube lijongene nendlela apho ababhali abasini esohlukileyo, abathi babazobe ngayo abalinganiswa abayintloko, abangamabhinqa kwizibhalo zabo zedrama zelwimi lwesiXhosa. Apha kuzobe kujongwe ingakumbi ababhali abasini sobuduna, ngenjongo yokuveza umba wokuba ababhali besini sobukhomokazi babazoba abalinganiswa ababhinqileyo nje ngabantu abangenamiqolo okuzimela ngaphandle kokuba kubekho indoda obomini babo. Aba babhali babazoba abalinganiswa ababhiqileyo phansti kwala ngcamango yokuba, apho umntu obhinqileyo ekumela afumaneke khona kusezimbizeni apho baphekela usapho lwabo rhoqo, ekucoceni umzi nasekukhuliseni abantwana, hayi enye into engaphaya koko. Ngoko ke eli phepha libhalwe ngenjongo yokuphelisa oku dodobalisa loo ngcamango. Baninzi kea bantu abaphikisana nale ndlela yaphotho lwamabhinqa ngamadoda abo, nangamanye amadoda nje jikilele, eli phepha lizobe lingqinelana nolo ninzi lwabantu abathi loo mpatho mbi yamabhinqa mayiphele, kuvezwe imeko yokuba kukho ulingano phakathi kwamabhinqa kunye nababt abasini sobukhomakazi. Int ethetha ukuba eli phepha lizakuti ligqithele lijonge kwaye liveze indlela apho kungati kuekho ulingwano phathi kwezini zimbini, nendlela apho uwonke wonke angakwazi ukuphila ngentlonipho omnye komnye kungekho zimpatho mbi, okanye sini sinesikhundla esiphakamileyo kunesinye.
- Full Text:
- Date Issued: 2016
- Authors: Bukula, Andiswa
- Date: 2016
- Subjects: Xhosa literature -- Research Gender identity in literature , Gender nonconformity Women -- South Africa -- Drama
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/18431 , vital:28645
- Description: Eli phepha lithiywe “Ukuzotywa kwabalinganiswa ababhinqileyo, abazintloko kwidrama zolwimi lwesiXhosa, bezotywa ngababhali besini sobuduna nesini sobukhomokazi liza kube lijongene nendlela apho ababhali abasini esohlukileyo, abathi babazobe ngayo abalinganiswa abayintloko, abangamabhinqa kwizibhalo zabo zedrama zelwimi lwesiXhosa. Apha kuzobe kujongwe ingakumbi ababhali abasini sobuduna, ngenjongo yokuveza umba wokuba ababhali besini sobukhomokazi babazoba abalinganiswa ababhinqileyo nje ngabantu abangenamiqolo okuzimela ngaphandle kokuba kubekho indoda obomini babo. Aba babhali babazoba abalinganiswa ababhiqileyo phansti kwala ngcamango yokuba, apho umntu obhinqileyo ekumela afumaneke khona kusezimbizeni apho baphekela usapho lwabo rhoqo, ekucoceni umzi nasekukhuliseni abantwana, hayi enye into engaphaya koko. Ngoko ke eli phepha libhalwe ngenjongo yokuphelisa oku dodobalisa loo ngcamango. Baninzi kea bantu abaphikisana nale ndlela yaphotho lwamabhinqa ngamadoda abo, nangamanye amadoda nje jikilele, eli phepha lizobe lingqinelana nolo ninzi lwabantu abathi loo mpatho mbi yamabhinqa mayiphele, kuvezwe imeko yokuba kukho ulingano phakathi kwamabhinqa kunye nababt abasini sobukhomakazi. Int ethetha ukuba eli phepha lizakuti ligqithele lijonge kwaye liveze indlela apho kungati kuekho ulingwano phathi kwezini zimbini, nendlela apho uwonke wonke angakwazi ukuphila ngentlonipho omnye komnye kungekho zimpatho mbi, okanye sini sinesikhundla esiphakamileyo kunesinye.
- Full Text:
- Date Issued: 2016
Ukuzotywa kwabalinganiswa abafunzele ukuzibulala kwimidlalo ekhethiweyo yesiXhosa
- Authors: Kondowe, Zandile Ziyanda
- Date: 2006
- Subjects: Acting -- Psychological aspects , Xhosa drama (Tragedy) -- History and criticism , Suicide in literature , Actors -- Psychology , Xhosa drama
- Language: Xhosa
- Type: Thesis , Masters , MA
- Identifier: vital:8473 , http://hdl.handle.net/10948/536 , Acting -- Psychological aspects , Xhosa drama (Tragedy) -- History and criticism , Suicide in literature , Actors -- Psychology , Xhosa drama
- Description: Olu phando lugqale kubalinganiswa abafunzele ukuzibulala kwimidlalo ekhethiweyo yesiXhosa. Kwisahluko sokuqala ngumkhombandlela wolu phando, intshayelelo, injongo yophando, ubume besifundo namagqabantshintshi ngentyila bomi zababhali endicaphule kwiincwadi zabo namagama angundoqo. Kwezinye izahluko ingcingane ezahlukeneyo nalapho endingabalula ekaFreud isayikho-analisisi ndinaba ngokubanzi kumabakala awabekileyo afana nokuzalwa, isini, odiphasi khompleksi nephupha nenxaxheba yakhe ekugubhululeni okuyimfihlakalo ngokuthi aphande ubomi bomntu obadlulayo ukuze kubenokunyangwa impixano ekuye ngaphakathi. Enye ingcingane esetyenzisiweyo yile ingokuzibulala nalapho kuphononongwa ukuba ngobani abazibulalayo, abaqinisekileyo ngokufa kwabo, ukuzibulala ngesivumelwano nembalelwano abazishiyayo xa umntu ezibulala. Kwezinye izahluko ndiyibeka icace intsusa neziphumo zokuzibulala kwamaxhoba, ndayiphicotha nendlela ekuxhatshazwe ngayo amalungelo abalinganiswa ngabazali babo kuba benyanzela le mitshato yebhaxa ngenjongo yokuzuza ikhazi ngentombi zabo, nayo imixholo enxulumene nolu phando ndiyicaphule imixholo efana neyothando noqhankqalazo nomxholo wokutshatiswa kwabantwana ngebhaxa. Isahluko sesihlanu ngumqukumbelo jikelele nophononongo ngolu phando.
- Full Text:
- Date Issued: 2006
- Authors: Kondowe, Zandile Ziyanda
- Date: 2006
- Subjects: Acting -- Psychological aspects , Xhosa drama (Tragedy) -- History and criticism , Suicide in literature , Actors -- Psychology , Xhosa drama
- Language: Xhosa
- Type: Thesis , Masters , MA
- Identifier: vital:8473 , http://hdl.handle.net/10948/536 , Acting -- Psychological aspects , Xhosa drama (Tragedy) -- History and criticism , Suicide in literature , Actors -- Psychology , Xhosa drama
- Description: Olu phando lugqale kubalinganiswa abafunzele ukuzibulala kwimidlalo ekhethiweyo yesiXhosa. Kwisahluko sokuqala ngumkhombandlela wolu phando, intshayelelo, injongo yophando, ubume besifundo namagqabantshintshi ngentyila bomi zababhali endicaphule kwiincwadi zabo namagama angundoqo. Kwezinye izahluko ingcingane ezahlukeneyo nalapho endingabalula ekaFreud isayikho-analisisi ndinaba ngokubanzi kumabakala awabekileyo afana nokuzalwa, isini, odiphasi khompleksi nephupha nenxaxheba yakhe ekugubhululeni okuyimfihlakalo ngokuthi aphande ubomi bomntu obadlulayo ukuze kubenokunyangwa impixano ekuye ngaphakathi. Enye ingcingane esetyenzisiweyo yile ingokuzibulala nalapho kuphononongwa ukuba ngobani abazibulalayo, abaqinisekileyo ngokufa kwabo, ukuzibulala ngesivumelwano nembalelwano abazishiyayo xa umntu ezibulala. Kwezinye izahluko ndiyibeka icace intsusa neziphumo zokuzibulala kwamaxhoba, ndayiphicotha nendlela ekuxhatshazwe ngayo amalungelo abalinganiswa ngabazali babo kuba benyanzela le mitshato yebhaxa ngenjongo yokuzuza ikhazi ngentombi zabo, nayo imixholo enxulumene nolu phando ndiyicaphule imixholo efana neyothando noqhankqalazo nomxholo wokutshatiswa kwabantwana ngebhaxa. Isahluko sesihlanu ngumqukumbelo jikelele nophononongo ngolu phando.
- Full Text:
- Date Issued: 2006
Ukuzotywa kwabalinganiswa ngokwesithako sobunzululwazi bume-ngqondo kwiincwadi zedrama ezikhethiweyo zesiXhosa, ngokweemeko zale mihla
- Authors: Bilatyi, Katy Nomthandazo
- Date: 2014
- Subjects: Xhosa drama Characters and characteristics in literature
- Language: Xhosa
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/9913 , vital:26632
- Description: Olu phando luza kugxila kuphononongo lobume bengqondo ephazamisekileyo yabalinganiswa, lujonga kananjalo izimo zabalinganiswa ngakumbi abatsha, indlela abacinga nabenza ngayo izinto. Olu phando luza kuphicotha obu bume bengqondo baba balinganiswa kusetyenziswa iincwadi zedrama ezilandelayo: uBuzani Kubawo, kaTamsanqa, uAmaza, kaQangule, uLiseza kutshona kaMbobo, u-Uthembisa noMakhaya kaMtywaku, Isikhwakhwa noBessie kaMtywaku kunye noNdiyekeni kaJongilanga. Olu thotho lweencwadi zedrama zikhethiweyo luza kusetyenziswa kwakhona ukubhentsisa ubungqondo-lukhuni lwababhali ekuzobeni abalinganiswa abatsha njengoongantweni nolwamvila lolu zobo kwindlela ulutsha oluziphethe ngayo. Olu phando lutshayelelwe ngesahluko sokuqala esiqulathe iingxaki zophando, iinjongo zophando, ukubaluleka kolu phando, okusele kubhaliwe ngophando olu, nalapho olu luza kwahluka khona. Isahluko sesibini sibonisa isithako sobuNzululwazi bume- ngqondo nezinye ezikhaphayo ezifana nenkcubeko apho kujongwa ukuba ingaba inkcubeko ayisetyenziswa na ngendlela ebangela ukuba abalinganiswa abatsha bazibone bekwimo emandla yoxinzelelo. Esi sithako senkcubeko sihambelana neso semo yokuziphatha apha kujongwa ukuba ingaba ukuziphatha kwaba balinganiswa batsha akuqhutywa yindlela uluntu olubabona ngayo bephenjelelwa nayindlela abazotywa ngayo ngababhali. Ezinye izithako ezikhapha esi sobume bengqondo seso sobudala apho kugxilwa kwindlela abajongelwa phantsi ngayo ngenxa yeminyaka yabo luluntu nabazali abaphela bebathathela izigqibo ezikhokelela kuxinzelelo nokuziphatha okungekuhle. Esokugqibela seso seOnomastiki apho kujongwa ukuba ingaba indlela abathiywe ngayo abalinganiswa ayinagalelo kusini na kwindlela oluziphethe ngayo ulutsha. Iimeko zoxinzelelo abazibhaqa bephantsi kwazo abatsha azibangelwa ngamagama abawanikiweyo na nekuye kulindeleke ukuba bawalandele ngenkani nokuba imeko ayivumi. Isahluko sesiThathu sakugxila kwizimo zabalinganiswa ze esesiNe sigxile kubalinganiswa nezigulo zengqondo.
- Full Text:
- Date Issued: 2014
- Authors: Bilatyi, Katy Nomthandazo
- Date: 2014
- Subjects: Xhosa drama Characters and characteristics in literature
- Language: Xhosa
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/9913 , vital:26632
- Description: Olu phando luza kugxila kuphononongo lobume bengqondo ephazamisekileyo yabalinganiswa, lujonga kananjalo izimo zabalinganiswa ngakumbi abatsha, indlela abacinga nabenza ngayo izinto. Olu phando luza kuphicotha obu bume bengqondo baba balinganiswa kusetyenziswa iincwadi zedrama ezilandelayo: uBuzani Kubawo, kaTamsanqa, uAmaza, kaQangule, uLiseza kutshona kaMbobo, u-Uthembisa noMakhaya kaMtywaku, Isikhwakhwa noBessie kaMtywaku kunye noNdiyekeni kaJongilanga. Olu thotho lweencwadi zedrama zikhethiweyo luza kusetyenziswa kwakhona ukubhentsisa ubungqondo-lukhuni lwababhali ekuzobeni abalinganiswa abatsha njengoongantweni nolwamvila lolu zobo kwindlela ulutsha oluziphethe ngayo. Olu phando lutshayelelwe ngesahluko sokuqala esiqulathe iingxaki zophando, iinjongo zophando, ukubaluleka kolu phando, okusele kubhaliwe ngophando olu, nalapho olu luza kwahluka khona. Isahluko sesibini sibonisa isithako sobuNzululwazi bume- ngqondo nezinye ezikhaphayo ezifana nenkcubeko apho kujongwa ukuba ingaba inkcubeko ayisetyenziswa na ngendlela ebangela ukuba abalinganiswa abatsha bazibone bekwimo emandla yoxinzelelo. Esi sithako senkcubeko sihambelana neso semo yokuziphatha apha kujongwa ukuba ingaba ukuziphatha kwaba balinganiswa batsha akuqhutywa yindlela uluntu olubabona ngayo bephenjelelwa nayindlela abazotywa ngayo ngababhali. Ezinye izithako ezikhapha esi sobume bengqondo seso sobudala apho kugxilwa kwindlela abajongelwa phantsi ngayo ngenxa yeminyaka yabo luluntu nabazali abaphela bebathathela izigqibo ezikhokelela kuxinzelelo nokuziphatha okungekuhle. Esokugqibela seso seOnomastiki apho kujongwa ukuba ingaba indlela abathiywe ngayo abalinganiswa ayinagalelo kusini na kwindlela oluziphethe ngayo ulutsha. Iimeko zoxinzelelo abazibhaqa bephantsi kwazo abatsha azibangelwa ngamagama abawanikiweyo na nekuye kulindeleke ukuba bawalandele ngenkani nokuba imeko ayivumi. Isahluko sesiThathu sakugxila kwizimo zabalinganiswa ze esesiNe sigxile kubalinganiswa nezigulo zengqondo.
- Full Text:
- Date Issued: 2014
Ukwowa mumwela nabangeli: transcendence, flight and inculturation in Zambian devotional artwork
- Authors: Mulenga, Aaron Samuel
- Date: 2020
- Subjects: Idols and images in art -- Zambia , Transcendence (Philosophy) in art , Christianity and culture -- Zambia , Flight in art , Christian art and symbolism -- Zambia , Representation (Philosophy) , Black people in art , Ethnicity in art , Group identity in art , Art and society -- Zambia , Yombwe, Laurence
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/146278 , vital:38511
- Description: With a focus on my artistic practice, this paper seeks to interrogate the tensions and overlaps in various representations of transcendence that have shaped my spirituality by interrogating how these have featured in Eurocentric Christian iconography and Zambian cultural practices, particularly cultural artefacts used for spiritual flight, housed in Zambian museums. Transcendence is understood by some as a change in a person’s physiological or psychological state that allows them to go beyond their experience of time, place or being. I understand transcendence to be the moment that one’s spirit is elevated beyond the limitations of their physical body. The use of Biblical text relating to flight will also be discussed as a comparative study to explore how transcendence through flight operates within Christianity and a Zambian cultural context. Furthermore, I shall interrogate how black artists (particularly Zambian), such as Laurence Yombwe, address the omission of black people from Christian iconography (which is predominantly depicted as white people). I aim to highlight the important role that representation plays in allowing for an individual to experience transcendence. I believe inculturation is a fitting solution to address some of the pitfalls in Christian iconography brought about due to the lack of representation of black people. Inculturation can be understood as an adaptation in the way the gospel of Jesus is preached to non-Christian cultures, and in turn, how these cultures influence the teachings of the gospel. Finally, I will explore how transcendence as a concept applies in my artworks and how the materials I use highlight this concept. Through my art, I grapple to combine what seem like disparate spiritual paradigms, arising from my culture and my faith. My artwork seeks to contribute to the work that particular artists (a majority of them black) are grappling with to correct the lack of representation of black people in Christian iconography. I will use the notion of inculturation as an avenue through which to interrogate the tensions I experience while exploring the concept of transcendence.
- Full Text:
- Date Issued: 2020
- Authors: Mulenga, Aaron Samuel
- Date: 2020
- Subjects: Idols and images in art -- Zambia , Transcendence (Philosophy) in art , Christianity and culture -- Zambia , Flight in art , Christian art and symbolism -- Zambia , Representation (Philosophy) , Black people in art , Ethnicity in art , Group identity in art , Art and society -- Zambia , Yombwe, Laurence
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/146278 , vital:38511
- Description: With a focus on my artistic practice, this paper seeks to interrogate the tensions and overlaps in various representations of transcendence that have shaped my spirituality by interrogating how these have featured in Eurocentric Christian iconography and Zambian cultural practices, particularly cultural artefacts used for spiritual flight, housed in Zambian museums. Transcendence is understood by some as a change in a person’s physiological or psychological state that allows them to go beyond their experience of time, place or being. I understand transcendence to be the moment that one’s spirit is elevated beyond the limitations of their physical body. The use of Biblical text relating to flight will also be discussed as a comparative study to explore how transcendence through flight operates within Christianity and a Zambian cultural context. Furthermore, I shall interrogate how black artists (particularly Zambian), such as Laurence Yombwe, address the omission of black people from Christian iconography (which is predominantly depicted as white people). I aim to highlight the important role that representation plays in allowing for an individual to experience transcendence. I believe inculturation is a fitting solution to address some of the pitfalls in Christian iconography brought about due to the lack of representation of black people. Inculturation can be understood as an adaptation in the way the gospel of Jesus is preached to non-Christian cultures, and in turn, how these cultures influence the teachings of the gospel. Finally, I will explore how transcendence as a concept applies in my artworks and how the materials I use highlight this concept. Through my art, I grapple to combine what seem like disparate spiritual paradigms, arising from my culture and my faith. My artwork seeks to contribute to the work that particular artists (a majority of them black) are grappling with to correct the lack of representation of black people in Christian iconography. I will use the notion of inculturation as an avenue through which to interrogate the tensions I experience while exploring the concept of transcendence.
- Full Text:
- Date Issued: 2020
Ultra-high precision diamond turning of advanced contact lens polymers
- Authors: Liman, Muhammad Mukhtar
- Date: 2020
- Subjects: Contact lenses , Electrostatic lenses Lenses -- Design and construction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46108 , vital:39496
- Description: Contact lens polymer-based materials are extensively used in the optical industry owing to their excellent corrosion resistance, the possibility of mass production and their ability to be processed without external lubrication. Owing to the fast growth in optical industries, contact lens (CL) requires high accuracy and a high surface quality. The demand for high-accuracy and minimal surface roughness drives the development of ultra-high precision machining technology with regard to single point diamond turning (SPDT). Ultra-high precision diamond turning is an advanced manufacturing technique employed in the machining of CLs owing to its capability of producing high optical surfaces with complex shapes and nanometric accuracy. Yet, even with the advances in ultra-high precision machining (UHPM), it is not continuously easy to achieve a highquality surface finish during polymers machining as the adhesion of the tool chip around the tool dictates the presence of electrostatic charges. The electrostatic charges encountered by a cutting tool when turning advanced CLs are important as they reflect the quality and condition of the tool, machine, fixture, and sometimes even the finished surface, which is responsible for tool wear and poor surface quality. This study investigates the role of cutting parameters, namely cutting speed, feed rate and depth of cut on surface roughness (Ra), electrostatic charge (ESC) and material removal rate (MRR), which determines machine economics and the quality of machining contact lens polymers. The experiments were mainly conducted on two different advanced polymeric materials: polymethyl methacrylate (PMMA) and Optimum Extreme (Roflufocon E) CLs. Experimentation was carried out on the Nanoform 250 ultra-grind turning machine with a monocrystalline diamond-cutting tool for machining the PMMA and Roflufocon E CL polymers, covering a wide range of machining parameters. Before conducting the experiments, a design of experiment was conducted according to the response surface methodology (RSM) that is based on the Box-Behnken Design (BBD). In addition, the research study focused on the determination of the optimum cutting conditions leading to minimum Ra and ESC as well as maximum productivity in the SPDT of the PMMA and Roflufocon E CL polymers, using a monocrystalline diamondcutting tool. The optimization was based on RSM together with the desirability function approach. In addition, a mathematical model was developed for Ra, ESC and MRR using a RSM regression analysis for PMMA and Roflufocon E CL polymers by means of Design Expert software. RSM allowed for the optimization of the cutting conditions for minimal Ra and ESC as well as maximal MRR, which provides an effective knowledge base for process parameters to enhance process performance in the SPDT of CL polymers. Furthermore, this study also deals with the development of Ra, ESC and MRR prediction models for the diamond turning of PMMA and Roflufocon E CL polymers, using the fuzzy logic based artificial intelligence (AI) method. The fuzzy logic model has been developed in terms of machining parameters for the prediction of Ra, ESC and MRR. To judge the accuracy and ability of the fuzzy logic model, an average percentage error was used. The comparative evaluation of experiments and the fuzzy logic approach suggested that the obtained average errors of Ra, ESC and MRR using the fuzzy logic system were in agreement with the experimental results. Hence, the developed fuzzy logic rules can be effectively utilized to predict the ESC, Ra and MRR of PMMA and Roflufocon E CL polymers in automated optical manufacturing environments for high accuracy and a reduction of computational cost. Moreover, owing to the brittle nature of optical polymers, the Roflufocon E CL polymer requires ductile-mode machining for improved surface quality. Molecular Dynamics (MD) simulation methods are thus applied to investigate the atomistic reaction at the tool/workpiece surface to clearly study and observe conditions occurring at nanometric scale in polymer machining. This research study is particularly concerned with the comparative analysis of experiments and a MD study of the Roflufocon E optical polymer nano cutting approach to the atomistic visualization of the plastic material flow at the tool/workpiece interface during cutting. The simulated MD acting force, machine stresses, and the temperature at the cutting region were evaluated to access the accuracy of the model. Hence, the nanomachining simulations were found to have a correlation to the experimental machining results.
- Full Text:
- Date Issued: 2020
- Authors: Liman, Muhammad Mukhtar
- Date: 2020
- Subjects: Contact lenses , Electrostatic lenses Lenses -- Design and construction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46108 , vital:39496
- Description: Contact lens polymer-based materials are extensively used in the optical industry owing to their excellent corrosion resistance, the possibility of mass production and their ability to be processed without external lubrication. Owing to the fast growth in optical industries, contact lens (CL) requires high accuracy and a high surface quality. The demand for high-accuracy and minimal surface roughness drives the development of ultra-high precision machining technology with regard to single point diamond turning (SPDT). Ultra-high precision diamond turning is an advanced manufacturing technique employed in the machining of CLs owing to its capability of producing high optical surfaces with complex shapes and nanometric accuracy. Yet, even with the advances in ultra-high precision machining (UHPM), it is not continuously easy to achieve a highquality surface finish during polymers machining as the adhesion of the tool chip around the tool dictates the presence of electrostatic charges. The electrostatic charges encountered by a cutting tool when turning advanced CLs are important as they reflect the quality and condition of the tool, machine, fixture, and sometimes even the finished surface, which is responsible for tool wear and poor surface quality. This study investigates the role of cutting parameters, namely cutting speed, feed rate and depth of cut on surface roughness (Ra), electrostatic charge (ESC) and material removal rate (MRR), which determines machine economics and the quality of machining contact lens polymers. The experiments were mainly conducted on two different advanced polymeric materials: polymethyl methacrylate (PMMA) and Optimum Extreme (Roflufocon E) CLs. Experimentation was carried out on the Nanoform 250 ultra-grind turning machine with a monocrystalline diamond-cutting tool for machining the PMMA and Roflufocon E CL polymers, covering a wide range of machining parameters. Before conducting the experiments, a design of experiment was conducted according to the response surface methodology (RSM) that is based on the Box-Behnken Design (BBD). In addition, the research study focused on the determination of the optimum cutting conditions leading to minimum Ra and ESC as well as maximum productivity in the SPDT of the PMMA and Roflufocon E CL polymers, using a monocrystalline diamondcutting tool. The optimization was based on RSM together with the desirability function approach. In addition, a mathematical model was developed for Ra, ESC and MRR using a RSM regression analysis for PMMA and Roflufocon E CL polymers by means of Design Expert software. RSM allowed for the optimization of the cutting conditions for minimal Ra and ESC as well as maximal MRR, which provides an effective knowledge base for process parameters to enhance process performance in the SPDT of CL polymers. Furthermore, this study also deals with the development of Ra, ESC and MRR prediction models for the diamond turning of PMMA and Roflufocon E CL polymers, using the fuzzy logic based artificial intelligence (AI) method. The fuzzy logic model has been developed in terms of machining parameters for the prediction of Ra, ESC and MRR. To judge the accuracy and ability of the fuzzy logic model, an average percentage error was used. The comparative evaluation of experiments and the fuzzy logic approach suggested that the obtained average errors of Ra, ESC and MRR using the fuzzy logic system were in agreement with the experimental results. Hence, the developed fuzzy logic rules can be effectively utilized to predict the ESC, Ra and MRR of PMMA and Roflufocon E CL polymers in automated optical manufacturing environments for high accuracy and a reduction of computational cost. Moreover, owing to the brittle nature of optical polymers, the Roflufocon E CL polymer requires ductile-mode machining for improved surface quality. Molecular Dynamics (MD) simulation methods are thus applied to investigate the atomistic reaction at the tool/workpiece surface to clearly study and observe conditions occurring at nanometric scale in polymer machining. This research study is particularly concerned with the comparative analysis of experiments and a MD study of the Roflufocon E optical polymer nano cutting approach to the atomistic visualization of the plastic material flow at the tool/workpiece interface during cutting. The simulated MD acting force, machine stresses, and the temperature at the cutting region were evaluated to access the accuracy of the model. Hence, the nanomachining simulations were found to have a correlation to the experimental machining results.
- Full Text:
- Date Issued: 2020
Ultra-high precision grinding of BK7 glass
- Authors: Onwuka, Goodness Raluchukwu
- Date: 2016
- Subjects: Machining , Machine-tools -- Monitoring , Acoustic emission
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: http://hdl.handle.net/10948/5203 , vital:20820
- Description: With the increase in the application of ultra-precision manufactured parts and the absence of much participation of researchers in ultra-high precision grinding of optical glasses which has a high rate of demand in the industries, it becomes imperative to garner a full understanding of the production of these precision optics using the above-listed technology. Single point inclined axes grinding configuration and Box-Behnken experimental design was developed and applied to the ultra-high precision grinding of BK7 glass. A high sampling acoustic emission monitoring system was implemented to monitor the process. The research tends to monitor the ultra-high precision grinding of BK7 glass using acoustic emission which has proven to be an effective sensing technique to monitor grinding processes. Response surface methodology was adopted to analyze the effect of the interaction between the machining parameters: feed, speed, depth of cut and the generated surface roughness. Furthermore, back propagation Artificial Neural Network was also implemented through careful feature extraction and selection process. The proposed models are aimed at creating a database guide to the ultra-high precision grinding of precision optics.
- Full Text:
- Date Issued: 2016
- Authors: Onwuka, Goodness Raluchukwu
- Date: 2016
- Subjects: Machining , Machine-tools -- Monitoring , Acoustic emission
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: http://hdl.handle.net/10948/5203 , vital:20820
- Description: With the increase in the application of ultra-precision manufactured parts and the absence of much participation of researchers in ultra-high precision grinding of optical glasses which has a high rate of demand in the industries, it becomes imperative to garner a full understanding of the production of these precision optics using the above-listed technology. Single point inclined axes grinding configuration and Box-Behnken experimental design was developed and applied to the ultra-high precision grinding of BK7 glass. A high sampling acoustic emission monitoring system was implemented to monitor the process. The research tends to monitor the ultra-high precision grinding of BK7 glass using acoustic emission which has proven to be an effective sensing technique to monitor grinding processes. Response surface methodology was adopted to analyze the effect of the interaction between the machining parameters: feed, speed, depth of cut and the generated surface roughness. Furthermore, back propagation Artificial Neural Network was also implemented through careful feature extraction and selection process. The proposed models are aimed at creating a database guide to the ultra-high precision grinding of precision optics.
- Full Text:
- Date Issued: 2016
Ultra-high precision machining of contact lens polymers
- Authors: Olufayo, Oluwole Ayodeji
- Date: 2015
- Subjects: Contact lenses , Polymers
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3001 , vital:20385
- Description: Contact lens manufacture requires a high level of accuracy and surface integrity in the range of a few nanometres. Amidst numerous optical manufacturing techniques, single-point diamond turning is widely employed in the making of contact lenses due to its capability of producing optical surfaces of complex shapes and nanometric accuracy. For process optimisation, it is ideal to assess the effects of various conditions and also establish their relationships with the surface finish. Presently, there is little information available on the performance of single point diamond turning when machining contact lens polymers. Therefore, the research work undertaken herewith is aimed at testing known facts in contact lens diamond turning and investigating the performance of ultra-high precision manufacturing of contact lens polymers. Experimental tests were conducted on Roflufocon E, which is a commercially available contact lens polymer and on Precitech Nanoform Ultra-grind 250 precision machining. Tests were performed at varying cutting feeds, speed and depth of cut. Initial experimental tests investigated the influence of process factors affecting surface finish in the UHPM of lenses. The acquired data were statistically analysed using Response Surface Method (RSM) to create a model of the process. Subsequently, a model which uses Runge-Kutta’s fourth order non-linear finite series scheme was developed and adapted to deduce the force occurring at the tool tip. These forces were also statistically analysed and modelled to also predict the effects process factors have on cutting force. Further experimental tests were aimed at establishing the presence of the triboelectric wear phenomena occurring during polymer machining and identifying the most influential process factors. Results indicate that feed rate is a significant factor in the generation of high optical surface quality. In addition, the depth of cut was identified as a significant factor in the generation of low surface roughness in lenses. The influence some of these process factors had was notably linked to triboelectric effects. This tribological effect was generated from the continuous rubbing action of magnetised chips on the cutting tool. This further stresses the presence of high static charging during cutting. Moderately humid cutting conditions presented an adequate means for static charge control and displayed improved surface finishes. In all experimental tests, the feed rate was identified as the most significant factor within the range of cutting parameters employed. Hence, the results validated the fact that feed rate had a high influence in polymer machining. The work also established the relationship on how surface roughness of an optical lens responded to monitoring signals and parameters such as force, feed, speed and depth of cut during machining and it generated models for prediction of surface finishes and appropriate selection of parameters. Furthermore, the study provides a molecular simulation analysis for validating observed conditions occurring at the nanometric scale in polymer machining. This is novel in molecular polymer modelling. The outcome of this research has contributed significantly to the body of knowledge and has provided basic information in the area of precision manufacturing of optical components of high surface integrity such as contact lenses. The application of the research findings presented here cuts across various fields such as medicine, semi-conductors, aerospace, defence, telecom, lasers, instrumentation and life sciences.
- Full Text:
- Date Issued: 2015
- Authors: Olufayo, Oluwole Ayodeji
- Date: 2015
- Subjects: Contact lenses , Polymers
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3001 , vital:20385
- Description: Contact lens manufacture requires a high level of accuracy and surface integrity in the range of a few nanometres. Amidst numerous optical manufacturing techniques, single-point diamond turning is widely employed in the making of contact lenses due to its capability of producing optical surfaces of complex shapes and nanometric accuracy. For process optimisation, it is ideal to assess the effects of various conditions and also establish their relationships with the surface finish. Presently, there is little information available on the performance of single point diamond turning when machining contact lens polymers. Therefore, the research work undertaken herewith is aimed at testing known facts in contact lens diamond turning and investigating the performance of ultra-high precision manufacturing of contact lens polymers. Experimental tests were conducted on Roflufocon E, which is a commercially available contact lens polymer and on Precitech Nanoform Ultra-grind 250 precision machining. Tests were performed at varying cutting feeds, speed and depth of cut. Initial experimental tests investigated the influence of process factors affecting surface finish in the UHPM of lenses. The acquired data were statistically analysed using Response Surface Method (RSM) to create a model of the process. Subsequently, a model which uses Runge-Kutta’s fourth order non-linear finite series scheme was developed and adapted to deduce the force occurring at the tool tip. These forces were also statistically analysed and modelled to also predict the effects process factors have on cutting force. Further experimental tests were aimed at establishing the presence of the triboelectric wear phenomena occurring during polymer machining and identifying the most influential process factors. Results indicate that feed rate is a significant factor in the generation of high optical surface quality. In addition, the depth of cut was identified as a significant factor in the generation of low surface roughness in lenses. The influence some of these process factors had was notably linked to triboelectric effects. This tribological effect was generated from the continuous rubbing action of magnetised chips on the cutting tool. This further stresses the presence of high static charging during cutting. Moderately humid cutting conditions presented an adequate means for static charge control and displayed improved surface finishes. In all experimental tests, the feed rate was identified as the most significant factor within the range of cutting parameters employed. Hence, the results validated the fact that feed rate had a high influence in polymer machining. The work also established the relationship on how surface roughness of an optical lens responded to monitoring signals and parameters such as force, feed, speed and depth of cut during machining and it generated models for prediction of surface finishes and appropriate selection of parameters. Furthermore, the study provides a molecular simulation analysis for validating observed conditions occurring at the nanometric scale in polymer machining. This is novel in molecular polymer modelling. The outcome of this research has contributed significantly to the body of knowledge and has provided basic information in the area of precision manufacturing of optical components of high surface integrity such as contact lenses. The application of the research findings presented here cuts across various fields such as medicine, semi-conductors, aerospace, defence, telecom, lasers, instrumentation and life sciences.
- Full Text:
- Date Issued: 2015
Ultra-high precision machining of rapidly solidified aluminium (RSA) alloys for optics
- Authors: Odedeyi, Peter Babatunde
- Date: 2021-12
- Subjects: Mechatronics Surface roughness -- Measurement
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55921 , vital:54400
- Description: The advancement of ultra-precision is one of the most adaptable machining processes in the manufacturing of very complex and high-quality surface structures for optics, industrial, medical, aerospace and communication applications. Studies have shown that single-point diamond turning has an outstanding ability to machine high-quality optical components at a nanometric scale. However, in a responsive cutting process, the nanometric machinability of these optical components can easily be affected by several factors. The call for increasing needs of optical systems has recently led to the development of newly modified aluminium grades of non-ferrous alloys characterized by finer microstructures, defined mechanical and physical properties. To date, there has been a lack of sufficient research into these new aluminium alloys. In modern ultra-precision machining, the high demands for smart and inexpensive cutting tools are becoming more relevant in recent precision machines. In monitoring and predicting high-quality surface, cutting forces in single point diamond turning are believed to be as critical as other machining processes due to their potential effects on the quality of surface roughness. Undermining such an important factor is a compromise between the machining process's efficiency and the increased cost of production. Therefore, a comprehensive scientific understanding of the Nano-cutting mechanics is critical, particularly on modelling and analysis of cutting force, surface roughness, chip vii formation, acoustic emission, material removal rates, and molecular dynamic simulation of the rapidly solidified aluminium alloys to bridge the gap between fundamentals and industrial-scale application. The study is divided into three essential sections. First, the development of a force sensor. Secondly, investigation of the effect of cutting parameters (i.e., cutting speed, feed rate, and cutting depth) on cutting force, acoustic emission (AE), material removal rate (MRR), chip formation, Nose radius, and surface roughness (Ra), which play a leading role in the determination of machine productivity and efficiency of single-point diamond turning of rapidly solidified aluminium alloys. Thirdly, a 3-D molecular dynamic (MD) simulation of RSA 6061 is also carried out to further understand the nanometric mechanism and characterization of the alloy. The experiment was mainly conducted using Precitech Nanoform ultra-grind 250 lathe machines on three different advanced optical aluminium alloys materials; these are RSA 443, RSA 905, and RSA 6061. , Thesis (PhD) -- Faculty of Engineering, the Built Environment and Information Technology, School of Engineering, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Odedeyi, Peter Babatunde
- Date: 2021-12
- Subjects: Mechatronics Surface roughness -- Measurement
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55921 , vital:54400
- Description: The advancement of ultra-precision is one of the most adaptable machining processes in the manufacturing of very complex and high-quality surface structures for optics, industrial, medical, aerospace and communication applications. Studies have shown that single-point diamond turning has an outstanding ability to machine high-quality optical components at a nanometric scale. However, in a responsive cutting process, the nanometric machinability of these optical components can easily be affected by several factors. The call for increasing needs of optical systems has recently led to the development of newly modified aluminium grades of non-ferrous alloys characterized by finer microstructures, defined mechanical and physical properties. To date, there has been a lack of sufficient research into these new aluminium alloys. In modern ultra-precision machining, the high demands for smart and inexpensive cutting tools are becoming more relevant in recent precision machines. In monitoring and predicting high-quality surface, cutting forces in single point diamond turning are believed to be as critical as other machining processes due to their potential effects on the quality of surface roughness. Undermining such an important factor is a compromise between the machining process's efficiency and the increased cost of production. Therefore, a comprehensive scientific understanding of the Nano-cutting mechanics is critical, particularly on modelling and analysis of cutting force, surface roughness, chip vii formation, acoustic emission, material removal rates, and molecular dynamic simulation of the rapidly solidified aluminium alloys to bridge the gap between fundamentals and industrial-scale application. The study is divided into three essential sections. First, the development of a force sensor. Secondly, investigation of the effect of cutting parameters (i.e., cutting speed, feed rate, and cutting depth) on cutting force, acoustic emission (AE), material removal rate (MRR), chip formation, Nose radius, and surface roughness (Ra), which play a leading role in the determination of machine productivity and efficiency of single-point diamond turning of rapidly solidified aluminium alloys. Thirdly, a 3-D molecular dynamic (MD) simulation of RSA 6061 is also carried out to further understand the nanometric mechanism and characterization of the alloy. The experiment was mainly conducted using Precitech Nanoform ultra-grind 250 lathe machines on three different advanced optical aluminium alloys materials; these are RSA 443, RSA 905, and RSA 6061. , Thesis (PhD) -- Faculty of Engineering, the Built Environment and Information Technology, School of Engineering, 2021
- Full Text:
- Date Issued: 2021-12
Ultrafast Photodynamics of the Indoline Dye D149 Adsorbed to Porous ZnO in Dye-Sensitized Solar Cells
- Rohwer, Egmont, Richter, Christoph, Heming, Nadine, Strauch, Kerstin, Litwinski, Christian, Nyokong, Tebello, Schlettwein, Derck, Schwoerer, Heinrich
- Authors: Rohwer, Egmont , Richter, Christoph , Heming, Nadine , Strauch, Kerstin , Litwinski, Christian , Nyokong, Tebello , Schlettwein, Derck , Schwoerer, Heinrich
- Language: English
- Type: Article
- Identifier: vital:7326 , http://hdl.handle.net/10962/d1020576
- Description: We investigate the ultrafast dynamics of the photoinduced electron transfer between surface-adsorbed indoline D149 dye and porous ZnO as used in the working electrodes of dye-sensitized solar cells. Transient absorption spectroscopy was conducted on the dye in solution, on solid state samples and for the latter in contact to a I−/I3− redox electrolyte typical for dye-sensitized solar cells to elucidate the effect of each component in the observed dynamics. D149 in a solution of 1:1 acetonitrile and tert-butyl alcohol shows excited-state lifetimes of 300±50 ps. This signature is severely quenched when D149 is adsorbed to ZnO, with the fastest component of the decay trace measured at 150±20 fs due to the charge-transfer mechanism. Absorption bands of the oxidized dye molecule were investigated to determine regeneration times which are in excess of 1 ns. The addition of the redox electrolyte to the system results in faster regeneration times, of the order of 1 ns. , Original publication is available at http://dx.doi.org/10.1002/cphc.201200715
- Full Text: false
- Authors: Rohwer, Egmont , Richter, Christoph , Heming, Nadine , Strauch, Kerstin , Litwinski, Christian , Nyokong, Tebello , Schlettwein, Derck , Schwoerer, Heinrich
- Language: English
- Type: Article
- Identifier: vital:7326 , http://hdl.handle.net/10962/d1020576
- Description: We investigate the ultrafast dynamics of the photoinduced electron transfer between surface-adsorbed indoline D149 dye and porous ZnO as used in the working electrodes of dye-sensitized solar cells. Transient absorption spectroscopy was conducted on the dye in solution, on solid state samples and for the latter in contact to a I−/I3− redox electrolyte typical for dye-sensitized solar cells to elucidate the effect of each component in the observed dynamics. D149 in a solution of 1:1 acetonitrile and tert-butyl alcohol shows excited-state lifetimes of 300±50 ps. This signature is severely quenched when D149 is adsorbed to ZnO, with the fastest component of the decay trace measured at 150±20 fs due to the charge-transfer mechanism. Absorption bands of the oxidized dye molecule were investigated to determine regeneration times which are in excess of 1 ns. The addition of the redox electrolyte to the system results in faster regeneration times, of the order of 1 ns. , Original publication is available at http://dx.doi.org/10.1002/cphc.201200715
- Full Text: false
Ultrafast Photodynamics of the Indoline Dye D149 Adsorbed to Porous ZnO in Dye‐Sensitized Solar Cells
- Rohwer, Egmont, Richter, Christoph, Heming, Nadine, Strauch, Kerstin, Litwinski, Christian, Nyokong, Tebello, Schlettwein, Derck, Schwoerer, Heinrich
- Authors: Rohwer, Egmont , Richter, Christoph , Heming, Nadine , Strauch, Kerstin , Litwinski, Christian , Nyokong, Tebello , Schlettwein, Derck , Schwoerer, Heinrich
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242153 , vital:51006 , xlink:href="https://doi.org/10.1002/cphc.201200715"
- Description: We investigate the ultrafast dynamics of the photoinduced electron transfer between surface-adsorbed indoline D149 dye and porous ZnO as used in the working electrodes of dye-sensitized solar cells. Transient absorption spectroscopy was conducted on the dye in solution, on solid state samples and for the latter in contact to a I−/I3− redox electrolyte typical for dye-sensitized solar cells to elucidate the effect of each component in the observed dynamics. D149 in a solution of 1:1 acetonitrile and tert-butyl alcohol shows excited-state lifetimes of 300±50 ps. This signature is severely quenched when D149 is adsorbed to ZnO, with the fastest component of the decay trace measured at 150±20 fs due to the charge-transfer mechanism. Absorption bands of the oxidized dye molecule were investigated to determine regeneration times which are in excess of 1 ns. The addition of the redox electrolyte to the system results in faster regeneration times, of the order of 1 ns.
- Full Text:
- Date Issued: 2013
- Authors: Rohwer, Egmont , Richter, Christoph , Heming, Nadine , Strauch, Kerstin , Litwinski, Christian , Nyokong, Tebello , Schlettwein, Derck , Schwoerer, Heinrich
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242153 , vital:51006 , xlink:href="https://doi.org/10.1002/cphc.201200715"
- Description: We investigate the ultrafast dynamics of the photoinduced electron transfer between surface-adsorbed indoline D149 dye and porous ZnO as used in the working electrodes of dye-sensitized solar cells. Transient absorption spectroscopy was conducted on the dye in solution, on solid state samples and for the latter in contact to a I−/I3− redox electrolyte typical for dye-sensitized solar cells to elucidate the effect of each component in the observed dynamics. D149 in a solution of 1:1 acetonitrile and tert-butyl alcohol shows excited-state lifetimes of 300±50 ps. This signature is severely quenched when D149 is adsorbed to ZnO, with the fastest component of the decay trace measured at 150±20 fs due to the charge-transfer mechanism. Absorption bands of the oxidized dye molecule were investigated to determine regeneration times which are in excess of 1 ns. The addition of the redox electrolyte to the system results in faster regeneration times, of the order of 1 ns.
- Full Text:
- Date Issued: 2013
Ultraprecision Diamond Turning of Monocrystalline Germanium
- Authors: Adeleke, Adeniyi Kehinde
- Date: 2021-04
- Subjects: Precision , Diamond Turning
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/44453 , vital:37835
- Description: Infrared lens production demands a surface with a high degree of accuracy and integrity. Surface roughness is a critical index of the measure of any product’s surface integrity. As a result of this, ultra-high machining technology has enjoyed extensive application, due to the continuous request for components within the range of 1 – 10nm roughness value. This technology has brought about the increased productivity and manufacture of quality products with a top-notch surface finish. Brittle materials such as germanium are hard to machine through the conventional processes such as lapping and polishing. Hence, the ultra-precision machining technology based on single point diamond turning (SPDT), is now been applied to machine germanium in the ductile mode, where material chip removal occurs by plastic deformation instead of a brittle fracture. During machining, selecting the optimal cutting conditions which includes cutting parameters and tool geometry, will not only improve productivity but ensure the minimisation of operating cost. In this research work, SPDT operation was used to conduct two experiments on a (monocrystalline germanium) workpiece. The first experiment was carried out using a diamond tool with a 1.5 mm nose radius, while the second experiment employed the use of a tool having a nose radius of 1.0 mm. A combination of machining parameters for each of the experimental runs were derived from a Box-Behnken method of design and the surface roughness was measured at each interval for both experiments with the aid of a Taylor Hopson PGI Dimension XL profilometer. Acoustic emission (AE) was also used as a quality sensing and tool-monitoring technique, to acquire signals and give indications of the expected surface roughness. Predictive models based on response surface methodology (RSM) and artificial neural networks (ANN), were developed for determining surface roughness. Optimisation was performed using RSM to determine the optimal set of machining factors, which results in optimal condition of the output response. Further investigations on the acquired signals were carried out using signal-processing techniques. Time-domain and time-frequency domain features acquired from the AE signals, together with the process parameters, were employed as input variables in the neural network design, having shown a good association with the surface roughness. ix Conclusively, it can be observed that the predictive model results and the experimental roughness measurements are in good agreement with each other. For accuracy and cost of computation, the RSM and ANN developed models for single-crystal germanium are compared using mean absolute error (MAE). , Thesis (M.Eng) -- Faculty of Engineering, the built environment & Information Technology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Adeleke, Adeniyi Kehinde
- Date: 2021-04
- Subjects: Precision , Diamond Turning
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/44453 , vital:37835
- Description: Infrared lens production demands a surface with a high degree of accuracy and integrity. Surface roughness is a critical index of the measure of any product’s surface integrity. As a result of this, ultra-high machining technology has enjoyed extensive application, due to the continuous request for components within the range of 1 – 10nm roughness value. This technology has brought about the increased productivity and manufacture of quality products with a top-notch surface finish. Brittle materials such as germanium are hard to machine through the conventional processes such as lapping and polishing. Hence, the ultra-precision machining technology based on single point diamond turning (SPDT), is now been applied to machine germanium in the ductile mode, where material chip removal occurs by plastic deformation instead of a brittle fracture. During machining, selecting the optimal cutting conditions which includes cutting parameters and tool geometry, will not only improve productivity but ensure the minimisation of operating cost. In this research work, SPDT operation was used to conduct two experiments on a (monocrystalline germanium) workpiece. The first experiment was carried out using a diamond tool with a 1.5 mm nose radius, while the second experiment employed the use of a tool having a nose radius of 1.0 mm. A combination of machining parameters for each of the experimental runs were derived from a Box-Behnken method of design and the surface roughness was measured at each interval for both experiments with the aid of a Taylor Hopson PGI Dimension XL profilometer. Acoustic emission (AE) was also used as a quality sensing and tool-monitoring technique, to acquire signals and give indications of the expected surface roughness. Predictive models based on response surface methodology (RSM) and artificial neural networks (ANN), were developed for determining surface roughness. Optimisation was performed using RSM to determine the optimal set of machining factors, which results in optimal condition of the output response. Further investigations on the acquired signals were carried out using signal-processing techniques. Time-domain and time-frequency domain features acquired from the AE signals, together with the process parameters, were employed as input variables in the neural network design, having shown a good association with the surface roughness. ix Conclusively, it can be observed that the predictive model results and the experimental roughness measurements are in good agreement with each other. For accuracy and cost of computation, the RSM and ANN developed models for single-crystal germanium are compared using mean absolute error (MAE). , Thesis (M.Eng) -- Faculty of Engineering, the built environment & Information Technology, 2021
- Full Text:
- Date Issued: 2021-04
Ultrasensitive detection of prostate-specific antigen using glucose-encapsulated nanoliposomes anti-PSA polyclonal antibody as detection nanobioprobes
- Mwanza, Daniel, Mfamela, Nololo, Adeniyi, Omotayo, Nyokong, Tebello, Mashazi, Philani N
- Authors: Mwanza, Daniel , Mfamela, Nololo , Adeniyi, Omotayo , Nyokong, Tebello , Mashazi, Philani N
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300268 , vital:57911 , xlink:href="https://doi.org/10.1016/j.talanta.2022.123483"
- Description: In this work, the preparation of glucose encapsulating nanoliposomes was achieved using two different lipid formulations, labelled as F1 and F2. Both formulations contained phosphatidylcholine (PC), oleylamido-4-butanoic acid (OABA) and in addition, F1 had cholesterol (CHO) while F2 contained cholesteroyl hemisussinate (CHEMS). These formulations were studied for their pH sensitivity and controlled release of encapsulated glucose for indirect detection of prostate-specific antigen (PSA) using sandwich immunoassay. As a signal generator, encapsulated glucose in nanoliposomes was quantified directly using the personal glucose meter (PGM) and colorimetrically using peroxidase property of horseradish peroxidase (HRP) enzyme and Pd|PdO as nanozymes. Controlled release of the encapsulated glucose was achieved using the pH effect or Triton-X 100 as a surfactant to destabilize the liposomal structure. The F2 formulation showed maximum controlled release at acidic phosphate buffer saline (PBS, pH 5.0). The concentration of encapsulated glucose was found to be high in F2 formulation and these were applied for the indirect detection of PSA. The limit of detection (LOD) values for PSA were found to be 53 fg mL−1, 64 fg mL−1 and 10 fg mL−1 when HRP, Pd|PdO and PGM were respectively used. The detection signal was linear over a wide concentration range for PSA including the clinical range of 4–10 ng mL−1. The HRP system showed low LOD value when compared with Pd|PdO nanozymes. PGM system gave lowest LOD values owing to the sensitivity of the system towards glucose. Pd|PdO nanozyme system showed good stability over a wide temperature up to 80 °C. PGM system required less reaction time (2 min), low reagents and results were readily generated in digital format.
- Full Text:
- Date Issued: 2022
- Authors: Mwanza, Daniel , Mfamela, Nololo , Adeniyi, Omotayo , Nyokong, Tebello , Mashazi, Philani N
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300268 , vital:57911 , xlink:href="https://doi.org/10.1016/j.talanta.2022.123483"
- Description: In this work, the preparation of glucose encapsulating nanoliposomes was achieved using two different lipid formulations, labelled as F1 and F2. Both formulations contained phosphatidylcholine (PC), oleylamido-4-butanoic acid (OABA) and in addition, F1 had cholesterol (CHO) while F2 contained cholesteroyl hemisussinate (CHEMS). These formulations were studied for their pH sensitivity and controlled release of encapsulated glucose for indirect detection of prostate-specific antigen (PSA) using sandwich immunoassay. As a signal generator, encapsulated glucose in nanoliposomes was quantified directly using the personal glucose meter (PGM) and colorimetrically using peroxidase property of horseradish peroxidase (HRP) enzyme and Pd|PdO as nanozymes. Controlled release of the encapsulated glucose was achieved using the pH effect or Triton-X 100 as a surfactant to destabilize the liposomal structure. The F2 formulation showed maximum controlled release at acidic phosphate buffer saline (PBS, pH 5.0). The concentration of encapsulated glucose was found to be high in F2 formulation and these were applied for the indirect detection of PSA. The limit of detection (LOD) values for PSA were found to be 53 fg mL−1, 64 fg mL−1 and 10 fg mL−1 when HRP, Pd|PdO and PGM were respectively used. The detection signal was linear over a wide concentration range for PSA including the clinical range of 4–10 ng mL−1. The HRP system showed low LOD value when compared with Pd|PdO nanozymes. PGM system gave lowest LOD values owing to the sensitivity of the system towards glucose. Pd|PdO nanozyme system showed good stability over a wide temperature up to 80 °C. PGM system required less reaction time (2 min), low reagents and results were readily generated in digital format.
- Full Text:
- Date Issued: 2022
Ultrasound-Triggered Release of 5-Fluorouracil from Soy Lecithin Echogenic Liposomes
- Ezekiel, Charles I, Bapolisi, Alain M, Walker, Roderick B, Krause, Rui W M
- Authors: Ezekiel, Charles I , Bapolisi, Alain M , Walker, Roderick B , Krause, Rui W M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183115 , vital:43913 , xlink:href="https://doi.org/10.3390/pharmaceutics13060821"
- Description: Colorectal cancer is the third most diagnosed cancer and the second leading cause of death. The use of 5-fluorouracil (5-FU) has been the major chemotherapeutic treatment for colorectal cancer patients. However, the efficacy of 5-FU is limited by drug resistance, and bone marrow toxicity through high-level expression of thymidylate synthase, justifying the need for improvement of the therapeutic index. In this study, the effects of ultrasound on echogenic 5-FU encapsulated crude soy liposomes were investigated for their potential to address these challenges. Liposomes were prepared by thin-film hydration using crude soy lecithin and cholesterol. Argon gas was entrapped in the liposomes for sonosensitivity (that is, responsiveness to ultrasound). The nanoparticles were characterized for particle size and morphology. The physicochemical properties were also evaluated using differential scanning calorimetry, Fourier transform infrared and X-ray diffraction. The release profile of 5-FU was assessed with and without 20 kHz low-frequency ultrasound waves at various amplitudes and exposure times. The result reveal that 5-FU-loaded liposomes were spherical with an encapsulation efficiency of approximately 60%. Approximately 65% of 5-FU was released at the highest amplitude and exposure time was investigated. The results are encouraging for the stimulated and controlled release of 5-FU for the management of colorectal cancer.
- Full Text:
- Date Issued: 2021
- Authors: Ezekiel, Charles I , Bapolisi, Alain M , Walker, Roderick B , Krause, Rui W M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183115 , vital:43913 , xlink:href="https://doi.org/10.3390/pharmaceutics13060821"
- Description: Colorectal cancer is the third most diagnosed cancer and the second leading cause of death. The use of 5-fluorouracil (5-FU) has been the major chemotherapeutic treatment for colorectal cancer patients. However, the efficacy of 5-FU is limited by drug resistance, and bone marrow toxicity through high-level expression of thymidylate synthase, justifying the need for improvement of the therapeutic index. In this study, the effects of ultrasound on echogenic 5-FU encapsulated crude soy liposomes were investigated for their potential to address these challenges. Liposomes were prepared by thin-film hydration using crude soy lecithin and cholesterol. Argon gas was entrapped in the liposomes for sonosensitivity (that is, responsiveness to ultrasound). The nanoparticles were characterized for particle size and morphology. The physicochemical properties were also evaluated using differential scanning calorimetry, Fourier transform infrared and X-ray diffraction. The release profile of 5-FU was assessed with and without 20 kHz low-frequency ultrasound waves at various amplitudes and exposure times. The result reveal that 5-FU-loaded liposomes were spherical with an encapsulation efficiency of approximately 60%. Approximately 65% of 5-FU was released at the highest amplitude and exposure time was investigated. The results are encouraging for the stimulated and controlled release of 5-FU for the management of colorectal cancer.
- Full Text:
- Date Issued: 2021
Ultrastructural development in the corpus allatum of the adult worker honey bee
- Authors: Lloyd, Gerry Trevor
- Date: 1993
- Subjects: Bees -- Anatomy , Honeybee
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5792 , http://hdl.handle.net/10962/d1005480 , Bees -- Anatomy , Honeybee
- Description: The ultrastructure of the corpus allatum of the Cape worker honey bee has been examined in a systematic way during the first thirty days of adult life. Corpus allatum size in the Cape worker honey bee shows the age-dependent increase typical of the European worker honey bee, and in the Cape worker bee, the duration of increase is protracted. Analysis of ultrastructural development provides three indicators of metabolic status: mean mitochondrial size, "light and dark" cells, and extracted vacuoles. Significant fluctuations in mean mitochondrial size indicate a cyclical nature of cellular activity. New thought on the nature of "light and dark" cells proves that "dark" cells are almost certainly active in the process of JH biosynthesis, whilst "light" cells are definitely not active in JH biosynthesis. Extracted vacuoles found in corpus allatum cells during this study are thought to be remnants of lipid vacuoles, and the build up in number of these vacuoles is regarded as an indicator of reduced biosynthetic activity. Since the two indicators of decreased JH production ("light" cells and extracted vacuoles) co-exist with smaller mean mitochondrial size, larger mean mitochondrial size is taken as indicating increased levels of JH biosynthesis. Hence, fluctuations in mean mitochondrial size suggest cycles in the levels of JH production in individual corpora allata of the adult worker honey bee.
- Full Text:
- Date Issued: 1993
- Authors: Lloyd, Gerry Trevor
- Date: 1993
- Subjects: Bees -- Anatomy , Honeybee
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5792 , http://hdl.handle.net/10962/d1005480 , Bees -- Anatomy , Honeybee
- Description: The ultrastructure of the corpus allatum of the Cape worker honey bee has been examined in a systematic way during the first thirty days of adult life. Corpus allatum size in the Cape worker honey bee shows the age-dependent increase typical of the European worker honey bee, and in the Cape worker bee, the duration of increase is protracted. Analysis of ultrastructural development provides three indicators of metabolic status: mean mitochondrial size, "light and dark" cells, and extracted vacuoles. Significant fluctuations in mean mitochondrial size indicate a cyclical nature of cellular activity. New thought on the nature of "light and dark" cells proves that "dark" cells are almost certainly active in the process of JH biosynthesis, whilst "light" cells are definitely not active in JH biosynthesis. Extracted vacuoles found in corpus allatum cells during this study are thought to be remnants of lipid vacuoles, and the build up in number of these vacuoles is regarded as an indicator of reduced biosynthetic activity. Since the two indicators of decreased JH production ("light" cells and extracted vacuoles) co-exist with smaller mean mitochondrial size, larger mean mitochondrial size is taken as indicating increased levels of JH biosynthesis. Hence, fluctuations in mean mitochondrial size suggest cycles in the levels of JH production in individual corpora allata of the adult worker honey bee.
- Full Text:
- Date Issued: 1993
Ultraviolet specular reflectance, electronic absorption and the excitation of fluorescence in single crystals of anthracene
- Authors: Wright, W H
- Date: 1966
- Subjects: Anthracene crystals -- Fluorescence , Ultraviolet spectroscopy -- Absorption , Reflectance
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5544 , http://hdl.handle.net/10962/d1013366
- Description: From introduction: The Fluorescence Excitation Spectrum or anthracene is known to vary considerably with the age and condition or the crystal. This thesis represents an attempt to improve the understanding of these variations. To put the problem on a quantitative basis it was found necessary to know both the ultraviolet reflection and absorption spectra. Reports of the reflection spectrum appear to have been confined to the case of polarised incident light. In addition the reflectivity measurements are always reported for a freshly cleaved surface. For these reasons the reflectivity of anthracene for various conditions of the reflecting surface was measured with unpolarised light. These varying reflectivities were used to further knowledge of the chemical processes at the crystal surface, as well as being used directly in the calculation of fluorescence excitation spectra. Reflection spectra with a- and b- crystallographic axis polarisations were also obtained. Since such spectra are reported in the literature it was possible, by comparison, to conclude that the experimental methods used in this thesis yielded valid results. The polarised measurements were used to obtain optical constants for the crystal. In the interests of readability most of the complicated process of converting the reflectivities to optical constants is dealt with in three appendices to the thesis.
- Full Text:
- Date Issued: 1966
- Authors: Wright, W H
- Date: 1966
- Subjects: Anthracene crystals -- Fluorescence , Ultraviolet spectroscopy -- Absorption , Reflectance
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5544 , http://hdl.handle.net/10962/d1013366
- Description: From introduction: The Fluorescence Excitation Spectrum or anthracene is known to vary considerably with the age and condition or the crystal. This thesis represents an attempt to improve the understanding of these variations. To put the problem on a quantitative basis it was found necessary to know both the ultraviolet reflection and absorption spectra. Reports of the reflection spectrum appear to have been confined to the case of polarised incident light. In addition the reflectivity measurements are always reported for a freshly cleaved surface. For these reasons the reflectivity of anthracene for various conditions of the reflecting surface was measured with unpolarised light. These varying reflectivities were used to further knowledge of the chemical processes at the crystal surface, as well as being used directly in the calculation of fluorescence excitation spectra. Reflection spectra with a- and b- crystallographic axis polarisations were also obtained. Since such spectra are reported in the literature it was possible, by comparison, to conclude that the experimental methods used in this thesis yielded valid results. The polarised measurements were used to obtain optical constants for the crystal. In the interests of readability most of the complicated process of converting the reflectivities to optical constants is dealt with in three appendices to the thesis.
- Full Text:
- Date Issued: 1966
Ulwaluko kwa Xhosa: young Xhosa men's lived experiences in the context of traditional male initiation
- Authors: Siswana, Anele
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3271 , http://hdl.handle.net/10962/d1020840
- Description: This thesis explores the lived experiences of young amaXhosa men in relation to U!walukokwa Xhosa (traditional male initiation [TMI]) and its impact on their sense of masculinity. The conceptual framework of this study is located within African epistemology focusing on indigenous knowledge systems (IKS) in South Africa. The study aimed at enabling young amaXhosa men who had undergone TMI to reflect on their first-hand, personal accounts of Ulwa/ukokwa Xhosa and manhood. Six semistructured interviews and a follow up focus group discussion were held with 23-27 years old amaXhosa men residing in Joza Township in Grahamstown, Eastern Cape. Participants were identified through purposive sampling. The thesis reports on the following findings: (a) the significance of the place/location of initiation, and the guise of modernity; (b) feelings of anticipation experienced by the young men; (c) the theme on ubudoda(manhood) affirmation Ndiyindoda!; (d) the theme on the concealment of pain (perseverance); (e) the theme on respect for self and others and ubuntu;(f) Uzimelegeqe (independence and autonomy) and (g) social role and responsibility. The paper argues for the relevance of TMI as a significantrite of passage from boyhood to manhood among amaXhosa men.
- Full Text:
- Date Issued: 2016
- Authors: Siswana, Anele
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3271 , http://hdl.handle.net/10962/d1020840
- Description: This thesis explores the lived experiences of young amaXhosa men in relation to U!walukokwa Xhosa (traditional male initiation [TMI]) and its impact on their sense of masculinity. The conceptual framework of this study is located within African epistemology focusing on indigenous knowledge systems (IKS) in South Africa. The study aimed at enabling young amaXhosa men who had undergone TMI to reflect on their first-hand, personal accounts of Ulwa/ukokwa Xhosa and manhood. Six semistructured interviews and a follow up focus group discussion were held with 23-27 years old amaXhosa men residing in Joza Township in Grahamstown, Eastern Cape. Participants were identified through purposive sampling. The thesis reports on the following findings: (a) the significance of the place/location of initiation, and the guise of modernity; (b) feelings of anticipation experienced by the young men; (c) the theme on ubudoda(manhood) affirmation Ndiyindoda!; (d) the theme on the concealment of pain (perseverance); (e) the theme on respect for self and others and ubuntu;(f) Uzimelegeqe (independence and autonomy) and (g) social role and responsibility. The paper argues for the relevance of TMI as a significantrite of passage from boyhood to manhood among amaXhosa men.
- Full Text:
- Date Issued: 2016
Umabatha: global and local
- Authors: Wright, Laurence
- Date: 2004
- Language: English
- Type: text , article
- Identifier: vital:7032 , http://hdl.handle.net/10962/d1007364 , https://doi.org/10.1080/00138390408691324
- Description: preprint , There can be few shows that test the dimensions and pitfalls of 'globalised' theatre as thoroughly as Welcome Msomi's Umabatha. The worldwide success of the show, in box-office terms, can hardly be argued with. And yet, in its very conception, the vehicle is so riven by intrinsic cultural, theatrical, class and 'nationist' tensions that different audiences cannot but reap utterly different experiences, depending on their own cultural and intellectual inheritance.The show is an instance where theatre practice (sometimes) obfuscates political and aesthetic discourse, showing how easily cultures miss each other and fail to connect, and how easily specific historical, geographical and imperial associations are swamped by shallow 'globalised' audience response.
- Full Text:
- Date Issued: 2004
- Authors: Wright, Laurence
- Date: 2004
- Language: English
- Type: text , article
- Identifier: vital:7032 , http://hdl.handle.net/10962/d1007364 , https://doi.org/10.1080/00138390408691324
- Description: preprint , There can be few shows that test the dimensions and pitfalls of 'globalised' theatre as thoroughly as Welcome Msomi's Umabatha. The worldwide success of the show, in box-office terms, can hardly be argued with. And yet, in its very conception, the vehicle is so riven by intrinsic cultural, theatrical, class and 'nationist' tensions that different audiences cannot but reap utterly different experiences, depending on their own cultural and intellectual inheritance.The show is an instance where theatre practice (sometimes) obfuscates political and aesthetic discourse, showing how easily cultures miss each other and fail to connect, and how easily specific historical, geographical and imperial associations are swamped by shallow 'globalised' audience response.
- Full Text:
- Date Issued: 2004
Umabatha: Zulu play or Shakespeare translation?
- Authors: Wright, Laurence
- Date: 2009
- Language: English
- Type: text , article
- Identifier: vital:7062 , http://hdl.handle.net/10962/d1007426 , https://www.taylorfrancis.com/books/e/9781351963381/chapters/10.4324%2F9781315264219-12
- Description: preprint , There can be few recent theatrical productions in greater need of interpretative effort than Welcome Msomi’s Umabatha. From its inception debate has raged over the cultural status of the production: was it an authentic expression of Zulu culture, or a tacky piece of ‘blacksploitation’? – to use Russell Vandenbroucke’s term. Was the production pleasing evidence of Shakespeare’s universality, a gift to the colonies returning joyfully to the motherland with interest accruing? Could it perhaps be a case of Zulu culture triumphing over Shakespeare, native invention swamping and overwhelming a colonially-imposed ‘high culture’? Was the show performing ‘Africa’ for the world and, if so, was this the way Africa ought to be represented in the twentieth century? Or were we perhaps looking at a fetishized theatrical commodity, wrenched from any authentic cultural roots, and circulating aimlessly but profitably through a globalised theatrical cosmopolis? Such speculative questions – and there are many others – have regularly jostled each other in the bulky heritage of Umabatha’s reception history. The central problem underlying this chapter is whether it might not be possible to define a basis for a more objective response to some of them, so that the issues involved no longer rest quite so slackly in the realm of mere critical opinion.
- Full Text:
- Date Issued: 2009
- Authors: Wright, Laurence
- Date: 2009
- Language: English
- Type: text , article
- Identifier: vital:7062 , http://hdl.handle.net/10962/d1007426 , https://www.taylorfrancis.com/books/e/9781351963381/chapters/10.4324%2F9781315264219-12
- Description: preprint , There can be few recent theatrical productions in greater need of interpretative effort than Welcome Msomi’s Umabatha. From its inception debate has raged over the cultural status of the production: was it an authentic expression of Zulu culture, or a tacky piece of ‘blacksploitation’? – to use Russell Vandenbroucke’s term. Was the production pleasing evidence of Shakespeare’s universality, a gift to the colonies returning joyfully to the motherland with interest accruing? Could it perhaps be a case of Zulu culture triumphing over Shakespeare, native invention swamping and overwhelming a colonially-imposed ‘high culture’? Was the show performing ‘Africa’ for the world and, if so, was this the way Africa ought to be represented in the twentieth century? Or were we perhaps looking at a fetishized theatrical commodity, wrenched from any authentic cultural roots, and circulating aimlessly but profitably through a globalised theatrical cosmopolis? Such speculative questions – and there are many others – have regularly jostled each other in the bulky heritage of Umabatha’s reception history. The central problem underlying this chapter is whether it might not be possible to define a basis for a more objective response to some of them, so that the issues involved no longer rest quite so slackly in the realm of mere critical opinion.
- Full Text:
- Date Issued: 2009
Umemulo and Zulu girlhood: From preservation to variations of ukuhlonipha nokufihla (respect and secrecy)
- Authors: Mntambo, Londiwe Nompilo
- Date: 2021-04
- Subjects: Virginity , Zulu (African people) -- Rites and ceremonies , Zulu (African people) -- Social life and customs , Virginity -- Social aspects , Women, Zulu -- South Africa -- KwaZulu-Natal -- Social conditions , Women -- Social and moral questions
- Language: English , Zulu
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/178352 , vital:42932
- Description: This study examines evolving definitions of ukuziphatha kahle that historically relied on the preservation of virginity for Zulu girls, who participate in the umemulo ceremony that marks the transition from girlhood to womanhood. It examines notions of Zulu girlhood as understood through preservation - ukugcina isibaya sikaBaba - and through respectability and secrecy - ukuhlonipha nokufihla. The study analyses how conceptions of ukuziphatha kahle (good behavior) have evolved in the context of sexual rights in the performance of Zulu girlhood. It is located in the interdisciplinary literature of global girlhood studies, and African feminist lenses of womanhood and rites of passages. The study draws from 26 interviews with Zulu women who have gone through umemulo, elder women who facilitate virginity testing and umemulo; and female relatives of women who have gone through umemulo in Estcourt, Wembezi, Paapkalius Fountain, Ntabamhlophe and Cornfields in KwaZulu-Natal. This thesis contextualises umemulo and ukuziphatha kahle (good behaviour) in democratic South Africa. Umemulo is a ritual done for a Zulu girl whose behaviour is deemed to be good. While this is clear, what constitutes ukuziphatha kahle (good behaviour) is contested. On stricter terms, ukuziphatha kahle means to be intombi nto (a virgin). The interviews with women who went through umemulo show that most of them were not virgins at the time of the ritual. The elder and younger women expressed that ukuziphatha kahle for them goes beyond the girl’s virginity. Instead, they understand it as a girl who does not have a child, and who has shown respect and obedience to her parents and elders. Strikingly, the study shows an inter-generational collusion between the younger and elder women, who maintain the outward appearance of virginity of the girls who participate in umemulo. The study argues that there are variations of ukuhlonipha (respect), which in the rights context of democratic South Africa overlap into ukufihla (secrecy). Importantly, it is clear that the concept of being a good Zulu womanhood holds and remains important for Zulu girls and women. However, the ways in which Zulu women experience and perform this is complex. The findings show that while many Zulu girls want to be seen as performing accepted good Zulu womanhood, they do so in ways that allow them to enjoy their sexual rights and pleasure. This is not a tension. , Thesis (MA) -- Faculty of Humanities, Politial and International Studies, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mntambo, Londiwe Nompilo
- Date: 2021-04
- Subjects: Virginity , Zulu (African people) -- Rites and ceremonies , Zulu (African people) -- Social life and customs , Virginity -- Social aspects , Women, Zulu -- South Africa -- KwaZulu-Natal -- Social conditions , Women -- Social and moral questions
- Language: English , Zulu
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/178352 , vital:42932
- Description: This study examines evolving definitions of ukuziphatha kahle that historically relied on the preservation of virginity for Zulu girls, who participate in the umemulo ceremony that marks the transition from girlhood to womanhood. It examines notions of Zulu girlhood as understood through preservation - ukugcina isibaya sikaBaba - and through respectability and secrecy - ukuhlonipha nokufihla. The study analyses how conceptions of ukuziphatha kahle (good behavior) have evolved in the context of sexual rights in the performance of Zulu girlhood. It is located in the interdisciplinary literature of global girlhood studies, and African feminist lenses of womanhood and rites of passages. The study draws from 26 interviews with Zulu women who have gone through umemulo, elder women who facilitate virginity testing and umemulo; and female relatives of women who have gone through umemulo in Estcourt, Wembezi, Paapkalius Fountain, Ntabamhlophe and Cornfields in KwaZulu-Natal. This thesis contextualises umemulo and ukuziphatha kahle (good behaviour) in democratic South Africa. Umemulo is a ritual done for a Zulu girl whose behaviour is deemed to be good. While this is clear, what constitutes ukuziphatha kahle (good behaviour) is contested. On stricter terms, ukuziphatha kahle means to be intombi nto (a virgin). The interviews with women who went through umemulo show that most of them were not virgins at the time of the ritual. The elder and younger women expressed that ukuziphatha kahle for them goes beyond the girl’s virginity. Instead, they understand it as a girl who does not have a child, and who has shown respect and obedience to her parents and elders. Strikingly, the study shows an inter-generational collusion between the younger and elder women, who maintain the outward appearance of virginity of the girls who participate in umemulo. The study argues that there are variations of ukuhlonipha (respect), which in the rights context of democratic South Africa overlap into ukufihla (secrecy). Importantly, it is clear that the concept of being a good Zulu womanhood holds and remains important for Zulu girls and women. However, the ways in which Zulu women experience and perform this is complex. The findings show that while many Zulu girls want to be seen as performing accepted good Zulu womanhood, they do so in ways that allow them to enjoy their sexual rights and pleasure. This is not a tension. , Thesis (MA) -- Faculty of Humanities, Politial and International Studies, 2021
- Full Text:
- Date Issued: 2021-04