• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 26
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 51
  • 19
  • 17
  • 11
  • 11
  • 10
  • 9
  • 8
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

The role of knowledge and importance of country-of-origin information in female consumers’ purchase intent of exotic crocodile leather accessories

Chambers, Hanri January 2017 (has links)
The study investigated the role of knowledge (objective knowledge and subjective knowledge) and the importance of country-of-origin in female consumers’ purchasing intent of exotic crocodile leather accessories. The study was conducted across South Africa and specifically concentrated on exotic crocodile leather accessories, which is a subset category in the luxury apparel industry. Consulta Research is a professional research company and was consulted to assist with the data collection. A quantitative descriptive approach was followed by developing an electronic survey design. Data was collected by using a selfadministrated online questionnaire, which was distributed by a research company. A crosssectional study was used to conduct the research. The data was collected by means of nonprobability convenient sampling. A total of 337 questionnaires were completed. Scales from previous research studies were adapted for the purpose of this study. The questionnaire was part of a bigger study and only five sections of the questionnaire were relevant to this specific study. Descriptive and association methods were used to analyse the data. Pearson correlation and Spearman correlation were used to analyse the data by means of relationships between variables. This study attempts to differentiate between consumers’ objective and subjective knowledge of luxury leather accessories. The construct objective knowledge was theoretically divided into intrinsic-related attributes and extrinsic-related attributes of the products of investigation. The relationship between objective knowledge and purchasing intent as well as the relationship between the importance of country-of-origin information and purchasing intent of exotic crocodile leather accessories was investigated. The findings regarding exotic crocodile leather accessories showed that females’ objective and subjective knowledge is limited, did not seem to find country-of-origin information important, had a weak purchase intent, and indicated that there was statistical significance only between the female consumers’ purchasing intent and their objective knowledge regarding the intrinsicrelated attributes of exotic crocodile leather accessories. The limitations of the study are that the results are based on non-probability convenience sampling, therefore the findings cannot be generalized to the whole South Africa, or to all the exotic leather industry markets for affluent consumers. One would have liked to have approached a population group that consisted of affluent respondents with an annual household income of more than R100 000. The study’s findings can contribute to the South African exotic crocodile leather industry and specifically to retailers, manufacturers, tanneries, and marketers. The findings and conclusions drawn in this study contribute to existing theory and could serve as the basis for future research in consumer behaviour, consumer science and the luxury exotic leather industry in South Africa. / Die studie het die rol van produk-kennis (objektiewe kennis en subjektiewe kennis) en die belangrikheid van inligting aangaande land-van-oorsprong in vroulike verbruikers se koopintensie met betrekking tot eksotiese krokodilleer-bykomstighede ondersoek. Die studie is regoor Suid-Afrika uitgevoer, en daar is spesifiek gekonsentreer op eksotiese krokodilleer-bykomstighede, wat ʼn sub-kategorie in die luukse klerebedryf uitmaak. Consulta Research is ʼn professionele navorsingsmaatskappy en is geraadpleeg om te help met die data-insameling. ʼn Kwantitatiewe deskriptiewe benadering is gevolg deur ʼn elektroniese opname-ontwerp te ontwikkel. Die data is ingesamel deur die gebruik van ʼn selftoegepaste aanlyn-vraelys, wat deur ʼn navorsingsmaatskappy versprei is. ʼn Dwarssneestudie is gebruik om die navorsing te doen. Die data is ingesamel deur middel van niewaarskynlikheids- gerieflikheid-steekproefneming. ʼn Totaal van 337 vraelyste is voltooi. Skale uit vorige navorsingstudies is aangepas vir die doeleindes van hierdie studie. Die vraelys het deel gevorm van ʼn groter studie en slegs vyf afdelings van die vraelys het betrekking op hierdie spesifieke studie. Pearson-korrelasie en Spearman-korrelasie is gebruik om die data deur middel van die verhoudings tussen veranderlikes te analiseer. Hierdie studie poog om te onderskei tussen die verbruikers se objektiewe en subjektiewe produk-kennis van luukse leer-produkte. Die produk wat genavors word se objektiewe kennis is teoreties onderverdeel in intrinsiek-verwante kenmerke en ekstrinsiek-verwante eienskappe. Die verhouding tussen objektiewe kennis en koopintensie, asook die verhouding tussen die belangrikheid van inligting aangaande die land-van-oorsprong en die koopintensie met betrekking tot eksotiese krokodilleer-bykomstighede is ondersoek. Die bevindinge met betrekking tot eksotiese krokodilleer-bykomstighede het getoon dat vroulike verbruikers beperkte objektiewe kennis en subjektiewe kennis beskik, blykbaar nie inligting aangaande land-van-oorsprong as belangrik beskou nie, ʼn swak koopintensie het, en het aangedui dat daar statistiese beduidendheid was slegs tussen die vroulike verbruikers se koopintensie en hul objektiewe kennis aangaande die intrinsiek-verwante eienskappe van eksotiese krokodilleer-bykomstighede. Die beperkinge van die studie is dat die resultate gebaseer was op nie-waarskynlikheidsgerieflikheidsteekproefneming, wat beteken dat die bevindings nie veralgemeen kan word na die hele Suid-Afrika nie, of na al die eksotieseleer-bedryfsmarkte vir welgestelde verbruikers nie. ʼn Mens sou graag ʼn populasiegroep wou kon bestudeer wat bestaan uit welgestelde respondente met ʼn jaarlikse huishoudelike inkomste van meer as R100 000. Die studie se bevindinge kan bydra tot die Suid-Afrikaanse eksotiese krokodilleerbedryf en spesifiek vir kleinhandelaars, vervaardigers, leerlooierye, en bemarkers. Die bevindinge en gevolgtrekkings in hierdie studie dra by tot bestaande teorie en kan dien as die basis vir toekomstige navorsing in verbruikersgedrag, verbruikerswetenskappe en die luukse, eksotiese leerbedryf in Suid-Afrika. / Dissertation (MSc)--University of Pretoria, 2017. / Consumer Science / MConsumer Science / Unrestricted
42

Measuring the Economic Value and Social Impact of Crocodile Tourism in Tarcoles, Costa Rica

Lemos, Ana 12 May 2017 (has links)
This thesis measures the economic value and social impact of tourism associated with crocodiles (Crocodylus acutus) in Tárcoles, Costa Rica. Crocodile tourism is unique compared to other tourism operations in Costa Rica because it is managed locally and has grown in an organic matter. Qualitative and quantitative data were collected from tourists and key informants who work, directly or indirectly, in crocodile tourism in the region. The results demonstrated that the economic benefits derived from nature-based tourism is an important strength and incentive for C. acutus conservation in Tárcoles. Bringing in an estimated USD 5,292,073.81 per year (estimated for 2014) in indirect sales, tourism is one of the main economic drivers and is central to the economic development of the region. Furthermore, understanding the social impacts of the tourism in Tárcoles is vital for ecosystem management and sustainability of the crocodile tourism industry.
43

South African female consumers' luxury value perceptions and needs for traceability information on exotic crocodile leather accessories

Jansen van Rensburg, Lize Tineke January 2017 (has links)
This study explored South African female consumers’ value perceptions as well as their needs for traceable information on exotic crocodile leather accessories. The Wiedmann, Hennigs and Siebels' Luxury Value Perception Scale (2007) and the Consumer Decision-making Process (Solomon & Rabolt, 2004:354) served as conceptual framework for the study. A questionnaire was distributed across South Africa and completed by willing participants. All participants were South African citizens, females of varyin g cultural backgrounds, including: African, Caucasian, Indian, Asian and Coloured individuals. The Consulta Research (Pty) Ltd used their extensive database of female consumers for sampling purposes. They managed to collect three hundred and thirty seven (337) completed and usable questionnaires. The Spearman's Correlation Coefficient, descriptive statistics, as well as exploratory factor analysis were used for data analysis. The results indicate that respondents to this questionnaire were not willing to pay marketrelated prices for exotic crocodile leather accessories. Findings of this study uncovered five luxury value perceptions as opposed to the four originally recognised by Wiedmann et al. (2007), namely Functional, Social, Financial, Individual gifts and Individual pleasure value perceptions. Of these luxury value perceptions, respondents indicated that the functional value perception was the most important to them. Traceable intrinsic and extrinsic-related attributes which can have an impact on decision-making by consumers were also explored. Results indicate that respondents found intrinsic-related attributes moderately important when deciding to purchase an exotic crocodile leather accessory. With regard to extrinsic-related product attributes, results indicate that most respondents found these extrinsic-related attributes moderately important. The notable exception was the position brand-holders held on child labour, which was indicated as important by most respondents. Results further indicated weak-positive, but statistically highly significant relationships between functional value perceptions and the importance of intrinsic-related as well as extrinsic-related information. Weak-positive, but statistically highly significant relationships were also conversely found between financial value perceptions and the importance of intrinsic and extrinsic-related information. There was a weak but statistically highly significant relationship between the individual giftvalue perception and the importance of extrinsic-related information as well as, conversely, a weak-positive statistically significant relationship between individual gift-value perceptions and the importance of intrinsic-related information. Purchase intent is an important determinant when consumers make decisions. Research results for this study have, however, indicated that respondents had a weak purchase intent for exotic crocodile leather accessories. Most respondents reported that they would never, at any time, buy an exotic crocodile leather accessory. Neither would they at some stage have the intention to buy an exotic crocodile leather accessory, or have a purchase interest for an exotic crocodile leather accessory. Finally, results show that there was a weak-positive, but statistically highly significant relationship between the importance of extrinsic-related product attributes and purchase intent. Results of this study make positive contributions towards the decision-making of various role players within the exotic crocodile leather accessory industry. Role players such as farmers, manufacturers, distributers, retailers and marketers can all benefit from the results. Based on the results of this study, recommendations for industry and future research are made. / Dié studie ondersoek Suid-Afrikaanse vroueverbruikers se waardepersepsies asook hul behoeftes aan navolgbare inligting oor eksotiese krokodilleerbykomstighede. Die Wiedmann, Hennigs and Siebels's Luxury Value Perception Scale (2007) en The Consumer Decisionmaking Process (Solomon & Rabolt, 2004:354) dien as die konseptuele raamwerk vir dié studie. 'n Vraelys is dwarsoor Suid-Afrika versprei en voltooi deur vrywillige deelnemers. Alle respondente was Suid-Afrikaanse burgers, vroue van 'n verskeidenheid etniese herkomste, waarby ingesluit: Afrikaan, Kaukasiese, Indiese, en kleurlingindividue. Consulta Research (Pty) Ltd het van hul uitgebereide databasis van vroueverbruikers in hul steekproef gebruik gemaak. Hulle het daarin geslaag drie om honderd sewe en dertig (337) voltooide en bruikbare vraelyste te bekom. Die Spearman’s Correlation Coefficient se beskrywende statistiek en oorsigtelike faktore-ontleding is gebruik in die data-analiese. Die bevindings dui daarop dat respondente op die vraelys nié bereid is om markverwante pryse te betaal vir eksotiese krokodilleer-bykomstighede nie. Verdere bevindings in dié studie het vyf luukse waardepersies blootgelê, teenoor die vier aangedui deur Wiedmann et al. (2007), naamlik: Funksionele, Sosiale, Finansiële, Individuele geskenke, en Individuele plesierwaardepersepsies. Van dié luuksewaardepersepsies het respondente aangedui dat die funksionele waardepersepsie vir hulle die belangrikste is. Opspoorbare en navolgbare intrinsieke of ekstrinsieke eienskappe wat 'n invloed kan hê op die besluitnemening deur verbruikers was matig-belangrik in die besluitproses vir die aankoop van 'n eksotiese krokodilleerbykomstigheid. Met betrekking tot ekstrinsieke produkeienskappe, dui resultate daarop dat respondente grootliks hierdie ekstrinsieke eieskappe ook as matig-belangrik geag het. Die opmerklike uitsondering is beleidstandpunte wat handelsmerkeienaars ten opsigte van kinderarbeid handhaaf en wat as belangrik deur respondente bejeën is. Resultate dui verder daarop dat swak-positiewe, maar 'n statisties hoogs belangrike verband bestaan tussen fuksionele waardepersepsies en intrinsiek-verwante asook ekstrinsiekeverwante beskouings. Verder is ook aangedui dat hoogs belangrike verbande tussen finaniële waardepersepsies, individuele geskenkwaardepersepsies en die belangrikheid van intrinsieke en ekstrinsieke inligting teenwoordig is. Daar was 'n swak, maar hoogs belangrike verband tussen die indivuele geskenkwaardepersepsie en die belangrikheid van ekstrinsieke-verwante inligting asook die omgekeerde statisties-belangrike, swak-positiewe verband tussen individuele geskenkwaardepersepsies en die belangrikheid van intrinsiek-verwante inligting word beklemtoon. Die aankoopvoorneme is 'n belangrike oorweging in verbruikers se besluitneming. Resultate in hierdie studie, dui egter daarop dat verbruikers 'n swak aankoopvoorneme vir eksotiese krokodilleerbykomstighede het. 'n Meerderheid van die respondente het aangedui dat hulle nooit 'n bykomstigheid van krokodilleer sal koop nie. Verder sal hulle in geen stadium enige voorneme koester om 'n krokoldilleerbykomstigheid aan te skaf of belangstel om só 'n produk te bekom nie. Laastens dui resultate op 'n swak-positiewe, maar statisties hoogsbetekenisvolle verband tussen die belangrikheid van ekstrinsieke produkeieskappe en koopvoorneme. Resulate van dié studie maak 'n positiewe bydrae tot die besluitneming van verskeie rolspelers binne die eksotiese krokodilleer-industrie. Rolspelers soos boere, vervaardigers, verspreiders, handelaars en bemarkers kan almal baat vind by dié bevindings. Sleutelwoorde: Vroueverbruiker van luukse bykomstighede; industrie vir luukse krolodilleerbykomstighede; luuksewaardepersepsies; intrinsieke produkeienskappe; ekstrinsieke produkeienskappe; aankoopvoorneme. / Dissertation (MSc)--University of Pretoria, 2017. / Consumer Science / MConsumer Science / Unrestricted
44

Characterisation, toxicology and clinical effects of crocodile oil in skin products / by Telanie Venter.

Venter, Telanie January 2012 (has links)
Natural oils are regularly used in cosmetics and as treatment for numeral skin conditions (Nielsen, 2006:575). The natural products industry is a multibillion dollar industry and has grown tremendously over the past few years. Natural oils used in cosmetics contain a range of fatty acids which contribute to several valuable properties in cosmetic- and personal care products. Fatty acids are divided into saturated acids and unsaturated acids (Vermaak et al., 2011:920,922). Because of the popularity and wide diversity of skin care products, it is necessary to create products that will distinguish themselves from the rest of the commercial products. To include natural oils in skin care products is a new way to prevent skin ageing, as well as other dermatological conditions. In this study, a natural oil, namely crocodile oil was used. Crocodile oil is obtained from the fat of the Nile crocodile (Crocodylus niloticus). Crocodile oil has the same composition as human skin oil. It only differs with regard to the percentages of the ingredients present. Crocodile oil contains saturated and unsaturated fatty acids. Because of the similar composition as human skin oil, crocodile oil will rarely be allergenic when applied to human skin and therefore will be a very accepted and harmless product to use (Croc city, 2012). There are many claims of positive results when crocodile oil containing products have been used. It includes fading of freckles, treatment of acne and pimple marks, dark lines, wrinkles and laugh lines. It also includes vanishing of dark shadows, sun spots and other discolorations. It helps prevent discolorations from forming and makes the skin softer, brighter and more attractive. It also controls rashness and dryness (Croc city, 2012). Because of crocodile oil’s anti-ageing, anti-fungal and anti-bacterial effects claimed by crocodile oil suppliers, and due to the fact that little scientific data is available on crocodile oil, it was decided to investigate the claims. In this study, the aims and objectives were to use natural oil, namely crocodile oil, and investigate the fatty acid profile, anti-microbial and anti-fungal activity, anti-oxidant activity, toxicity studies, stability determination of crocodile oil lotion and clinical efficacy testing of the anti-ageing effects. To determine the fatty acid profile of crocodile oil, fatty acid methyl ester (FAME) analysis with gas chromatography were used. Identification of FAME peaks in the samples was made by comparing the relative retention times of FAME peaks from samples to those of reference standards. The composition of fatty acids in crocodile oil compared well to fatty acids found in human skin oil. Anti-microbial and anti-fungal tests were done by Envirocare Laboratories, North-West University, Potchefstroom. Staphylococcus aureus, Esterichia coli, Pseudomanas aeruginosa, Candida albicans, Brasiliensis, Propionibacterium acnes and Trichophyton rubrum cultures were used to determine the anti-microbial and anti-fungal activity of crocodile oil. Unfortunately no activity was observed. The anti-oxidant properties of crocodile oil and crocodile oil lotion were determined by using the most commonly used method for measuring Malondialdehyde (MDA) in biological samples, namely the thiobarbituric acid (TBA) test. This method is based on spectrophotometric quantification of the pink complex formed after reaction of MDA with two molecules of TBA. No anti-oxidant activity was observed in the oil or the lotion. Toxicity studies were performed by Dr. D. Goosen (BVSc Hons. Pret.) from Tswane University of Technology (Pretoria, South Africa). The studies showed that the lotion had no toxicity in the skin sensitisation, acute dermal toxicity and acute dermal irritation studies. To determine the stability of the crocodile oil lotion, the formulated products were store at 25 °C / 60% RH (relative humidity), 30 °C / 60% RH and 40 °C / 75% RH for 6 months in the original packaging as well as a glass container. The stability tests included pH, viscosity, visual appearance assessment, zeta-potential, droplet size and mass loss. The crocodile cream lotion was stable over the 6 months period in both containers. Clinical efficacy testing was performed at the CEL (Clinical Efficacy Laboratory) of the North-West University, Potchefstroom, South Africa. A short-term study over a period of 3 h was performed to investigate the hydrating effects of crocodile oil lotion. A long-term study over a period of 12 weeks was performed to examine the anti-ageing effects of crocodile oil lotion. An erythema study was also conducted to test the anti-erythema properties of crocodile oil lotion. Although the crocodile oil lotion as well as the placebo lotion showed an increase in skin hydration, there was no significant difference between the two treatments. Crocodile oil lotion also showed no anti-erythema properties. / Thesis (PhD (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013.
45

Characterisation, toxicology and clinical effects of crocodile oil in skin products / by Telanie Venter.

Venter, Telanie January 2012 (has links)
Natural oils are regularly used in cosmetics and as treatment for numeral skin conditions (Nielsen, 2006:575). The natural products industry is a multibillion dollar industry and has grown tremendously over the past few years. Natural oils used in cosmetics contain a range of fatty acids which contribute to several valuable properties in cosmetic- and personal care products. Fatty acids are divided into saturated acids and unsaturated acids (Vermaak et al., 2011:920,922). Because of the popularity and wide diversity of skin care products, it is necessary to create products that will distinguish themselves from the rest of the commercial products. To include natural oils in skin care products is a new way to prevent skin ageing, as well as other dermatological conditions. In this study, a natural oil, namely crocodile oil was used. Crocodile oil is obtained from the fat of the Nile crocodile (Crocodylus niloticus). Crocodile oil has the same composition as human skin oil. It only differs with regard to the percentages of the ingredients present. Crocodile oil contains saturated and unsaturated fatty acids. Because of the similar composition as human skin oil, crocodile oil will rarely be allergenic when applied to human skin and therefore will be a very accepted and harmless product to use (Croc city, 2012). There are many claims of positive results when crocodile oil containing products have been used. It includes fading of freckles, treatment of acne and pimple marks, dark lines, wrinkles and laugh lines. It also includes vanishing of dark shadows, sun spots and other discolorations. It helps prevent discolorations from forming and makes the skin softer, brighter and more attractive. It also controls rashness and dryness (Croc city, 2012). Because of crocodile oil’s anti-ageing, anti-fungal and anti-bacterial effects claimed by crocodile oil suppliers, and due to the fact that little scientific data is available on crocodile oil, it was decided to investigate the claims. In this study, the aims and objectives were to use natural oil, namely crocodile oil, and investigate the fatty acid profile, anti-microbial and anti-fungal activity, anti-oxidant activity, toxicity studies, stability determination of crocodile oil lotion and clinical efficacy testing of the anti-ageing effects. To determine the fatty acid profile of crocodile oil, fatty acid methyl ester (FAME) analysis with gas chromatography were used. Identification of FAME peaks in the samples was made by comparing the relative retention times of FAME peaks from samples to those of reference standards. The composition of fatty acids in crocodile oil compared well to fatty acids found in human skin oil. Anti-microbial and anti-fungal tests were done by Envirocare Laboratories, North-West University, Potchefstroom. Staphylococcus aureus, Esterichia coli, Pseudomanas aeruginosa, Candida albicans, Brasiliensis, Propionibacterium acnes and Trichophyton rubrum cultures were used to determine the anti-microbial and anti-fungal activity of crocodile oil. Unfortunately no activity was observed. The anti-oxidant properties of crocodile oil and crocodile oil lotion were determined by using the most commonly used method for measuring Malondialdehyde (MDA) in biological samples, namely the thiobarbituric acid (TBA) test. This method is based on spectrophotometric quantification of the pink complex formed after reaction of MDA with two molecules of TBA. No anti-oxidant activity was observed in the oil or the lotion. Toxicity studies were performed by Dr. D. Goosen (BVSc Hons. Pret.) from Tswane University of Technology (Pretoria, South Africa). The studies showed that the lotion had no toxicity in the skin sensitisation, acute dermal toxicity and acute dermal irritation studies. To determine the stability of the crocodile oil lotion, the formulated products were store at 25 °C / 60% RH (relative humidity), 30 °C / 60% RH and 40 °C / 75% RH for 6 months in the original packaging as well as a glass container. The stability tests included pH, viscosity, visual appearance assessment, zeta-potential, droplet size and mass loss. The crocodile cream lotion was stable over the 6 months period in both containers. Clinical efficacy testing was performed at the CEL (Clinical Efficacy Laboratory) of the North-West University, Potchefstroom, South Africa. A short-term study over a period of 3 h was performed to investigate the hydrating effects of crocodile oil lotion. A long-term study over a period of 12 weeks was performed to examine the anti-ageing effects of crocodile oil lotion. An erythema study was also conducted to test the anti-erythema properties of crocodile oil lotion. Although the crocodile oil lotion as well as the placebo lotion showed an increase in skin hydration, there was no significant difference between the two treatments. Crocodile oil lotion also showed no anti-erythema properties. / Thesis (PhD (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013.
46

The Iconography on Objects from the Kuntur Wasi Site / La iconografía en los objetos del sitio de Kuntur Wasi

Onuki, Yoshio 10 April 2018 (has links)
The archaeological materials associated with the Kuntur Wasi Temple in Cajamarca reveal rich iconographic representations. They are important for revealing the cosmology that gave meaning to the ceremonial activities of the temple, as well as the daily life of the people. This article presents a brief description of the characteristics of the stone sculpture and mural paintings found at Kuntur Wasi. It ascribes a meaning related to the myth and ritual of water and to the important role played by aquatic reptiles such as crocodiles, caimans or anacondas. / Los materiales asociados a los templos y tumbas del sitio de Kuntur Wasi, Cajamarca, contienen representaciones iconográficas que conviene analizar para entender mejor la cosmología que daba fundamento a las actividades ceremoniales en el templo y a las de la vida cotidiana del pueblo. El presente trabajo es un avance en tal sentido, pues resume las características de las representaciones figurativas en los monolitos y la pintura mural. El análisis revela que el templo de Kuntur Wasi encierra elementos que permiten descifrar el significado del mito y del culto al agua, así como del papel importante que tenía el reptil acuático —en forma de caimán, cocodrilo o anaconda— para este grupo social.
47

RealizaÃÃo de PrÃtica de FÃsica em Bancada e SimulaÃÃo Computacional para Promover o Desenvolvimento da Aprendizagem Significativa e Colaborativa / Realization of Pratical Physics Bench and Computer Simulation to promote the Development of the Collaborative and Meaningful Learning.

MÃrio Jorge Nunes Costa 25 January 2013 (has links)
nÃo hà / A avaliaÃÃo educacional brasileira, segundo o PISA, se reflete no quadro de desigualdades econÃmicas e sociais vivenciadas entre os hemisfÃrios norte e sul planetÃrios. A presente pesquisa objetiva investigar, de que maneira, a concepÃÃo e realizaÃÃo de uma atividade pedagÃgica colaborativa de experimentaÃÃo de bancada, apoiada por atividades pedagÃgicas de simulaÃÃo e modelagem computacional, pÃde contribuir para favorecer o desenvolvimento do processo de aprendizagem significativa. As atividades foram efetivadas enfatizando-se a construÃÃo e (re) significaÃÃo de conceitos de fÃsica, especificamente no tema eletricidade e circuitos elÃtricos. Foram inicialmente verificados os conhecimentos prÃvios dos alunos, atravÃs da aplicaÃÃo de questionÃrios de sondagem de conhecimentos. Em seguida, se realizaram aulas teÃricas, com foco na formaÃÃo de organizadores prÃvios. Em seguida, promoveram-se atividades fazendo uso pedagÃgico de software educacionais de simulaÃÃo e modelagem de circuitos de resistores elÃtricos, PhET e Crocodile, quando os alunos inter-relacionaram e/ou (re) significaram conceitos. Para tanto, vivenciaram e realizaram as mediÃÃes de grandezas elÃtricas e demais atividades propostas, sob a mediaÃÃo do presente Professor-Pesquisador. Numa etapa consecutiva, os alunos realizaram a prÃtica de experimentaÃÃo de bancada, relacionada ao mesmo tema anterior de circuitos elÃtricos, para (re) significar os conhecimentos dos alunos, partindo do estudo do brilho de lÃmpadas. Em todas as atividades laboratoriais, foram utilizados instrumentos de coleta de dados do tipo: gravaÃÃes de Ãudio e vÃdeo; respostas e relatos escritos pelos alunos nos roteiros das atividades de simulaÃÃo e modelagem computacional, atividade experimental de bancada e questionÃrios de sondagem de conhecimentos prÃvios e avaliaÃÃo da prÃtica pedagÃgica. A pesquisa classifica-se como qualitativa, exploratÃria e pesquisa-aÃÃo. No referencial teÃrico-metodolÃgico, destacam-se, como principais contribuiÃÃes, os pressupostos de: Dorneles, AraÃjo, Veit, no uso de software de simulaÃÃo e dificuldades de aprendizagem; Ribeiro et al., nos aspectos da integraÃÃo de laboratÃrios de experimentaÃÃo e simulaÃÃo, para facilitar o desenvolvimento da aprendizagem colaborativa, na qual destacam-se Ausubel, Novak e Valente; Moraes, Galiazzi e Okada, quanto ao mapeamento cognitivo da anÃlise textual discursiva; e Almeida, Prado e GÃes, quanto à anÃlise qualitativa de dados multidimensionais, com o uso do software CHIC. Sem perda de generalidade, a anÃlise dos dados de campo evidencia preliminarmente que: as atividades de simulaÃÃo e modelagem computacional contribuÃram para a formaÃÃo de organizadores prÃvios relativos a conceitos de eletricidade, leitura e interpretaÃÃo de medidas elÃtricas. Posteriormente, a atividade de experimentaÃÃo auxiliou os alunos a (re) significarem os conhecimentos de eletricidade e circuitos elÃtricos, as atividades de leitura, mediÃÃo e interpretaÃÃo de grandezas elÃtricas, auxiliando o desenvolvimento da aprendizagem significativa. A anÃlise dos resultados tambÃm revela indÃcios que, com a integraÃÃo entre as atividades de experimentaÃÃo de bancada e softwares de simulaÃÃo e modelagem computacional, os alunos, de forma colaborativa e minoritariamente cooperativa, (re) significaram e reelaboraram conhecimentos relativos a circuitos elÃtricos de resistores, porÃm, em determinados momentos, caracterizavam dificuldades de aprendizagem, pois nÃo conseguiam expressar suas concepÃÃes e argumentaÃÃes, de maneira a se apropriar corretamente dos conceitos de eletricidade.
48

Pollutants associated with mass mortality of Nile crocodiles (Crocodylus niloticus) in the Kruger National Park, South Africa / P.L. Booyens

Booyens, Paul Lodewyk January 2011 (has links)
The first of a series of mass mortalities of Nile crocodiles in the Olifants and Letaba rivers in the Kruger National Park (KNP) was reported in the winter of 2008. The present study investigated the levels and possible effects on eggshell thickness of inorganic elements and organic pollutants in Nile crocodile eggs from these rivers, and comparing them with eggs from a reference crocodile farm and a reference dam inside the KNP. The egg contents were analyzed for chlorinated organic compounds and brominated flame retardants. Eggshells and egg contents were analyzed for inorganic elements. The elemental concentrations in the eggshells and contents were low when compared with previous studies. The highest concentrations were found in the eggs from the reference crocodile farm. The eggs from the reference dam and the crocodile farm had thicker shells, and the eggs from the Olifants and Letaba rivers had thinner shells. Not all eggs in a female develop at the same rate, while eggshell formation presumably occurs at the same time for all eggs. As a result, the elemental profile of egg contents may differ between eggs of the same clutch, but less so for the shells. Weak or no associations were found between the elemental concentrations of the content and eggshells and eggshell thinning. A possible organic pollutant–induced eggshell thinning effect was found. The compounds found were not at levels that could have caused the mortalities, but may affect the sex ratios through endocrine disruption. Further studies are therefore required. / Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.
49

Pollutants associated with mass mortality of Nile crocodiles (Crocodylus niloticus) in the Kruger National Park, South Africa / P.L. Booyens

Booyens, Paul Lodewyk January 2011 (has links)
The first of a series of mass mortalities of Nile crocodiles in the Olifants and Letaba rivers in the Kruger National Park (KNP) was reported in the winter of 2008. The present study investigated the levels and possible effects on eggshell thickness of inorganic elements and organic pollutants in Nile crocodile eggs from these rivers, and comparing them with eggs from a reference crocodile farm and a reference dam inside the KNP. The egg contents were analyzed for chlorinated organic compounds and brominated flame retardants. Eggshells and egg contents were analyzed for inorganic elements. The elemental concentrations in the eggshells and contents were low when compared with previous studies. The highest concentrations were found in the eggs from the reference crocodile farm. The eggs from the reference dam and the crocodile farm had thicker shells, and the eggs from the Olifants and Letaba rivers had thinner shells. Not all eggs in a female develop at the same rate, while eggshell formation presumably occurs at the same time for all eggs. As a result, the elemental profile of egg contents may differ between eggs of the same clutch, but less so for the shells. Weak or no associations were found between the elemental concentrations of the content and eggshells and eggshell thinning. A possible organic pollutant–induced eggshell thinning effect was found. The compounds found were not at levels that could have caused the mortalities, but may affect the sex ratios through endocrine disruption. Further studies are therefore required. / Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.
50

Assessing the costs and benefits of water use for production and the potential of water demand management in the Crocodile Catchment of South Africa

Crafford, J.G. (Jacobus Gert) 23 July 2007 (has links)
In South Africa, precipitation is extremely variable and water is scarce. South Africa is also a country with great welfare needs. Challenging economic development targets and plans therefore need to be implemented successfully within the constraints of limited water supply and unreliable water availability. These economic development plans are underpinned by the development and growth of economic activities such as agriculture, mining, energy production and many types of small, medium and micro enterprises, which are some of the largest water using sectors in the economy. Within these activities, increased competition places pressure on water users to keep supplying their markets with competitively priced goods, while rising costs of new water supplies puts pressure on water users to allocate sufficient water to their production processes. These market forces and the relative scarcity of water as an economic production factor, impact on financial viability and imply that the economic efficiency of water use becomes increasingly important. The National Water Act of 1998 (NWA) is a legislative response to this situation, and promotes a radical shift towards efficiency and equity goals in water allocation. Water users who require water as an input to economic activities are consequently seriously revising their water use patterns in response to one of the major implications of the NWA and its related principal strategy: water demand management. Water demand management strives to adhere to the principles of equity, social justice, economic efficiency and environmental sustainability, which are central to the NWA. This study evaluates the costs and benefits of water use in order to simulate the effects of water demand management activities on a catchment economy. The results of a number of studies were combined to generate an economy-wide model: a Social Accounting Matrix (SAM), for the case study area and to simulate the direct and indirect effects of water demand management on the people, the economy and the natural environment in the area. Water demand management (WDM) is defined as consisting of two phases. In the first phase, goals of full cost recovery, improving water use efficiency and allocating water optimally are targeted. The second phase of WDM arrives when a situation of absolute water scarcity is reached within a catchment. In this phase water demand outweighs water supply and water has to be allocated according to its scarcity value. Water markets play a large role here. The SAM was used to simulate the direct and indirect impacts on the economy and the environment of a number of WDM related scenarios. Water e-allocation decisions and the effects of various WDM policy instruments, such as reduction of water use subsidies and increases in water tariffs were simulated. Unintended consequences of other environmental policies on water use, in this case, carbon tax, were explored. Water scarcity predictions were done, and some of the transaction costs involved in water trading was quantified. The study concludes with a discussion on the indirect effects on the economy, the environment and people of changes affecting the agricultural (including forestry) activities. The direct and indirect impacts of WDM policies on the economy and the environment, and the importance of environmental-economic models in water cost benefit modeling are also discussed. Implications for policy and management are highlighted. This study shows specifically how, through modelling various scenarios, policy decisions aimed at managing specific variables (e.g. water use, carbon emissions) have an economic and environmental impact much wider than the sector in which the policy was targeted for. Each scenario shows how a water transaction, or a change in subsidy in the agricultural (including forestry) sector, could impact on the output of other economic sectors, and therefore the economy as a whole. It is therefore evident that policy decisions, which are implemented at a macro level, and could have a major direct impact on a wider range of economic sectors, should be carefully considered as they could have large, undesirable, unintended consequences. / Dissertation (MSc (Agricultural Economics))--University of Pretoria, 2004. / Agricultural Economics, Extension and Rural Development / MSc (Agric) / unrestricted

Page generated in 0.4307 seconds