Thesis (M. Sc. (Computer Science))--Rhodes University, 2005.

A large number of people throughout the world have naturally kinky hair that may be very difficult to manage. These people often subject their hair to vigorous and harsh treatment processes in order to straighten it and hence make it more manageable. Hair braiding is a popular and fashionable trend amongst many people, in particular people of African descent. Braided hairstyles serve to preserve hair and protect it, and to give it time to rejuvenate after a period of harsh treatment. During the braiding process synthetic hair is attached to natural hair by weaving a length of the natural hair into one end of each braid. Other materials like wool or cotton may be use used to achieve different hairstyles and textures. Several strands of natural hair are used to secure each braid. The braids are normally left intact for a number of weeks or even months. Although braiding is a helpful African hair grooming practice, the process of taking down or detangling the braids is labor intensive and entails each braid being cut just below where the natural hair ceases and the natural hair being untangled from the braid using a safety pin, a needle or a fine toothed comb. The labor and long hours required to detangle braided hairstyles often results in braid wearers frustratingly pulling on their braided hair. This behavior inevitably destroys the hair follicle and leaves the hair damaged. According to a study conducted by the University of Cape Town’s dermatology department, braiding may be the root cause of traction alopecia (TA) amongst braid wearers. Traction alopecia is a form of alopecia, or gradual hair loss that is caused primarily by excessive pulling forces applied to the hair. The purpose of this current study was to investigate the factors, other than braid tightness, that affect the way and ease with which braids are detangled from the human hair. The study hypothesized that frictional forces present in braided hair were amongst these factors. It was hypothesized that introducing a lubricating formulation in the braids would allow for easier braid detangling. In order to decrease the prevalence of traction alopecia from braided hair, two hair strengthening actives were included in the test formulation. The study investigated the effects of the test formulations on braid detangling, hair friction and on the tensile strength of human hair. The study found that the method used did not pick up any significant differences between the braid detangling forces of treated braids when compared to the braid vi detangling forces of untreated hair. The same method used to measure braid detangling forces was able to show that there are variations in the braid detangling forces of different sections along the braid length. The method to measure braid detangling was based on the principles of hair combability measurements. The study also found that although the method used to measure braid detangling forces was unsuccessful in picking up significant differences in braid detangling forces of treated hair and untreated hair, the method used to measure the frictional forces of human hair showed that the frictional forces of hair treated with test formulations were significantly different than that of untreated hair. The method used to measure frictional forces was based on the capstan approach. The Capstan method measures the forces required to slide a weighted hair fibre over a curved surface of reference material. The interaction between the weighted fibre and the reference material simulates the movement of hair out of a braid ensemble in the braid detangling process. The optimum mixture with the minimum coefficient of friction, predicted a coefficient of friction of 0.61 ± 0.04. The optimum formulation was found to be one that contained 30% Cyclopentasiloxane , 0% PEG-12 Dimethicone, 10% 18-MEA, 29% water, 10% hair strengthening actives, 12.86% emulsifier combination and 8% other oils. The study also showed that including hair strengthening actives, such as hydrolysed proteins had significant effects in the tensile strength properties of chemically treated African hair.

Many computer graphics applications make use of virtual humans. Methods for modelling and rendering hair are needed so that hairstyles can be added to the virtual humans. Modelling and rendering hair is challenging due to the large number of hair strands and their geometric properties, the complex lighting effects that occur among the strands of hair, and the complexity and large variation of human hairstyles. While methods have been developed for generating hair, no methods exist for generating African hair, which differs from hair of other ethnic groups. This thesis presents methods for modelling and rendering African hair. Existing hair modelling and rendering techniques are investigated, and the knowledge gained from the investigation is used to develop or enhance hair modelling and rendering techniques to produce three different forms of hair commonly found in African hairstyles. The different forms of hair identified are natural curly hair, straightened hair, and braids or twists of hair. The hair modelling techniques developed are implemented as plug-ins for the graphics program LightWave 3D. The plug-ins developed not only model the three identified forms of hair, but also add the modelled hair to a model of a head, and can be used to create a variety of African hairstyles. The plug-ins significantly reduce the time spent on hair modelling. Tests performed show that increasing the number of polygons used to model hair increases the quality of the hair produced, but also increases the rendering time. However, there is usually an upper bound to the number of polygons needed to produce a reasonable hairstyle, making it feasible to add African hairstyles to virtual humans. The rendering aspects investigated include hair illumination, texturing, shadowing and antialiasing. An anisotropic illumination model is developed that considers the properties of African hair, including the colouring, opacity and narrow width of the hair strands. Texturing is used in several instances to create the effect of individual strands of hair. Results show that texturing is useful for representing many hair strands because the density of the hair in a texture map does not have an effect on the rendering time. The importance of including a shadowing technique and applying an anti-aliasing method when rendering hair is demonstrated. The rendering techniques are implemented using the RenderMan Interface and Shading Language. A number of complete African hairstyles are shown, demonstrating that the techniques can be used to model and render African hair successfully. / GNU Ghostscript 7.07

Intersectional analyses have made clear that Black women as a group fare far worse in employment outcomes than their race and gender counterparts. However, there is little research that examines differences among Black women. The purpose of this dissertation is to examine how Black women are perceived intra-intersectionally, or within the intersection of race and gender. Black women are not monolithic and it is important to illuminate how they are perceived differently from one another. This dissertation explores the effects of differences in skin tone and hair texture among Black women seeking a management position. It was hypothesized that Black women with lighter skin and/or straight hair would be characterized more positively than Black women with darker skin and/or kinky hair; this hypothesis was not supported. However, for negative characteristics, the hypothesis that Black women with darker skin would be characterized more negatively than Black women with lighter skin was confirmed. Further, it was found that hair texture significantly interacts with skin tone such that darker-skinned Black women with kinky hair were characterized more negatively than light-skinned women with kinky hair. There were no significant differences found between the skin tone and hair texture of Black women on salary offers, but there was a marginally significant skin tone effect for perceptions of success in that lighter-skinned Black women are perceived to be more successful than darker-skinned Black women. This study sheds light on the need to look at the intersection of both skin tone and hair texture in order to fully understand how negative stereotypes apply to Black women.

This thesis aims to allow the meanings engendered by various black hairstyle choices to emerge as discursive texts with which to further explore issues of black identity in post-apartheid South Africa. It seeks to identify what, if any, new discursive spaces and possibilities are operational in the post-apartheid capitalist context, and how identities are moulded by, and in tum, influence these possibilities. Operating within a discourse analytic approach, this research did not intend to establish fixed and generalisable notions of identity, but by unpacking the discursive baggage attached to historically loaded subjectivities it is concerned with reflecting identity as an ongoing and reflexive project. Entailing a diverse selection of texts, the analysis includes self-generated texts (stemming from interviews, a focus group and participant observation), and public domain texts (stemming from online and print media articles). Chapters 5 - 9 constitute the textual analysis. Using a consumer hair care product as a text, chapter 5 serves as an introduction to discourses surrounding black hair as a variously constructed object. This focus is concerned, more specifically, with the construction of black hair as a 'natural' object in chapter 6. Chapter 7 examines black hair gemonies and the " problematic classification and de/classification of class and consumer identities. Discourses pertaining to the construction and positioning of gendered and sexual subjectivities are explored in chapter 8. Finally, chapter 9 is concerned with the operations of discourses as they function to construct essentialised or hybrid conceptions of identity. The implications for black identity construction in post-apartheid South Africa are discussed in chapter 10 alongside a deconstruction of the research method and researcher positioning.