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  • 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.
61

Efeito do ultrassom na extra??o e caracter?sticas do amido de car?-do-ar (Dioscorea bulbifera) / Effect Ultrasound on extraction and starch characteristics of yam (Dioscorea bulbifera)

Bernardo, Cristiany Oliveira 26 February 2016 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-10-13T11:27:52Z No. of bitstreams: 1 2011 - Cristiany Oliveira Bernardo.pdf: 1740458 bytes, checksum: ae55b89b5f70448972ad5987c95450b1 (MD5) / Made available in DSpace on 2016-10-13T11:27:52Z (GMT). No. of bitstreams: 1 2011 - Cristiany Oliveira Bernardo.pdf: 1740458 bytes, checksum: ae55b89b5f70448972ad5987c95450b1 (MD5) Previous issue date: 2016-02-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Among the different possibilities of use in the food industry, ultrasound can be considered an alternative to substitute or reduce the use of chemicals in extraction processes or modification of starches. When used in the extraction, enables higher purity of the obtained starch. The starch-the-air yam has physical characteristics desirable for applications such as thickening agent or disintegrating tablet formulations, for example, however, this extraction is hindered by the presence starch mucilage this tubercle. The aim of this study was to review the effect of ultrasound on the extraction and modification of several starches, evaluate their use in starch extraction of yam and its impact on characteristics this starch. After evaluating the chemical composition of tubers, previously washed, peeled and crushed in a blender. Then the crushed sample subjected to ultrasound. Different times (3, 6 to 9 minutes) and amplitudes (12, 40 and 68%) were evaluated by the Box Benker experimental design, furthermore evaluated the control treatment (0% amplitude) and ?T6? (15 minutes, 70% amplitude), totaling 7 treatments (T1, T2, T3, T4, T5, T6 and control). After sonication, the suspension was filtered and the extraction continued by successive washings, centrifugation and drying in an oven. After evaluating the performance of the extraction, the different treatments were characterized by analysis of chemical composition, instrumental analysis of color, scanning electron microscopy, optical microscopy, particle size, pattern of crystallinity, swelling power and solubility, paste clarity, paste properties and thermal properties and absolute density. There was increase in yield of 29,85% (control) to 32,09%, when used longer time and amplitude (15 min and 70% amplitude). The ultrasound caused damage to the surface of starch and reduced starch crystallinity peak, characterized as type B. Additionally, increased swelling power and consequently the paste viscosity of some treatments. However, 15 minutes, 70% amplitude (T6), reduced the swelling power, the paste viscosity and paste clarity and increased the setback. Therefore, despite the small increase in yield, when used ultrasound during extraction, damage was caused in the structure of starch, as well as changes in its physical and chemical characteristics / Dentre as diferentes possibilidades de utiliza??o na ind?stria de alimentos, o ultrassom pode ser considerado uma alternativa para substituir ou reduzir a utiliza??o de subst?ncias qu?micas em processos de extra??o ou modifica??o de amidos. Quando utilizado na extra??o, possibilita maior pureza do amido obtido. O amido de car?-do-ar possui caracter?sticas f?sicas desej?veis para aplica??es como agente espessante ou desintegrante em formula??es de comprimidos, por exemplo. No entanto, a extra??o desse amido ? dificultada pela presen?a de mucilagem nesse tub?rculo. O objetivo do presente estudo foi revisar o efeito do ultrassom na extra??o e modifica??o de diversos amidos, como milho, arroz, mandioca, batata, entre outros, avaliar sua utiliza??o na extra??o do amido de car?-do-ar e seu impacto sobre as caracter?sticas desse amido. Ap?s avaliar a composi??o centesimal do car?-do-ar, o mesmo foi lavado, descascados e triturados em liquidificador. Em seguida a amostra triturada foi submetida ao ultrassom. Diferentes tempos (3, 6 e 9 minutos) e amplitudes (12, 40 e 68%) foram avaliados por meio do planejamento experimental Box Benker. Al?m desses foram avaliados os tratamentos controle (0% amplitude) e T6 (15 minutos, 70% amplitude), totalizando 7 tratamentos (T1, T2, T3, T4, T5, T6 e controle). A extra??o prosseguiu por meio de filtra??o, lavagens sucessivas, centrifuga??o e secagem em estufa. Ap?s avaliar o rendimento da extra??o, os diferentes tratamentos foram caracterizados por meio das an?lises de composi??o centesimal, an?lise instrumental de cor, poder de inchamento e solubilidade, claridade de pasta, determina??o das propriedades t?rmicas e propriedades de pasta, padr?o de cristalinidade, microscopia eletr?nica de varredura, microscopia ?ptica, determina??o do tamanho de part?cula e densidade absoluta do amido. Houve aumento do rendimento de 29,85% (controle) para 32,09%, quando utilizado o maior tempo e amplitude (15 min e 70% amplitude). O ultrassom provocou danos na superf?cie do amido e reduziu os picos de cristalinidade do amido, caracterizados como tipo B. Al?m disso, aumentou o poder de inchamento e consequentemente a viscosidade de pasta de alguns tratamentos. No entanto, 15 minutos e 70% de amplitude (T6), do tratamento com ultrassom, reduziu o poder de inchamento, a viscosidade de pasta e a claridade de pasta e aumentou a tend?ncia ? retrograda??o. Dessa forma, apesar do pequeno aumento do rendimento quando utilizado o ultrassom durante a extra??o, danos foram provocados na estrutura desse amido, assim como altera??es das suas caracter?sticas f?sico-qu?micas.
62

The Effects of Message Matching in Climate Change Persuasion

Penner, Matthew R. 01 April 2019 (has links)
Public opinions of climate change are not consistent with the reality that climate change is occurring. Effective persuasive messages must be created to ensure that irreparable damage to the environment is prevented. This study investigated the cognitive processes that occur when an individual is exposed to a persuasive message regarding environmental concerns that is matched to an individual’s personality characteristics like right wing authoritarianism and purity. Messages on two environmental topics (solar panels and the Environmental Protection Agency) were created. Each topic was framed in multiple ways to test hypotheses about personality-based message matching. Participants completed a thought listing task after reading about each of the topics, and then indicated their attitudes toward the message topics. Participants were also asked to complete several individual difference scales. Reported attitudes were regressed on individual differences and message frame type in order to determine the effects of message matching on attitudes. While the results do not support a matching effect for purity, an effect of right wing authoritarianism was found after controlling for environmental apathy. This suggests that individual difference matching effects do exist, although they may be more complex than initially hypothesized.
63

Cultural Factors and Concepts of Pollution: Colorectal Cancer and Health Behaviors among Ashkenazi Jewish Women

Besterman-Dahan, Karen 23 October 2008 (has links)
The colorectal cancer (CRC) incidence in Ashkenazi Jews has been found to be highest of any ethnic group in the world (Feldman, 2001). It is currently unclear how culture and religion influence health behaviors of U.S. Ashkenazi Jews, as well as what other socio-cultural factors influence AJ women's attitudes towards CRC risk and screening practices. This study aimed at exploring and describing the cultural and religious influences on health behaviors and beliefs related to CRC in Ashkenazi Jewish women. Research participants included seven key informants (rabbis) and forty-two Ashkenazi Jewish women ages 50 and up. Methods included in-depth, qualitative interviews and focus groups. The study also utilized a demographic survey which included questions about baseline knowledge of colorectal cancer in Ashkenazi Jews, and a ten-item American Cancer Society's Questionnaire on Experiences with and Attitude toward CRC Screening. Participants were recruited from Tampa synagogues and community using non-probabilistic sampling. Results revealed only 5% of participants were aware of the increased prevalence of colorectal cancer in Ashkenazi Jews; still, most participants (88%) were up to date on colorectal cancer screening. Judaic purity laws did not resonate with many participants, and for those who did follow them, they did not take a view of bodily functions as being impure. A consistent description of a 'Jewish way' of looking at health emerged, involving both the push for education, which increases knowledge about and access to healthcare, as well as the core Jewish tenet of the infinite value of life. No significant differences were found among the screening practices of the three self-identified denominations, and only breast and cervical cancer screening were found to be significantly different between those who have ever had a CRC screening and those who have not. Recommendations highlight the need for future research in this area including larger samples, further exploring core Jewish tenets as related to health behaviors in this population, partnering with the Jewish community for interventions, and addressing ways to better track CRC incidence, mortality and screening in this population in order to raise awareness.
64

Hemicellulose Extraction From Agro-food Industrial Wastes And Its Apllication In Foods

Yilmaz, Hilal 01 September 2012 (has links) (PDF)
Hemicellulose is a valuable component of agro-food industrial wastes. Although there are some potential usage areas of hemicelluloses such as drug manufacture, encapsulation, and emulsification in food processing plants, they are not extensively utilized. In this study, effective extraction methods of the hemicelluloses from agro-food industrial wastes (corn peels and sugar beet pulp) and their application as coating material for banana fruits were investigated. Firstly, the effects of raw material type, particle size, and extraction conditions (alkaline concentration, temperature, time) and methods (direct alkaline extraction, alkaline extraction after component removal, and acidic extraction method) on hemicellulose yields were investigated. Sugar beet pulp and corn wastes were used as raw material. Alkali extraction resulted in 40.2% pure extracts while acidic hydrolysis gave only 27.4% purity in the same extraction conditions. The optimal extraction conditions were found as 30&deg / C temperature, 10% NaOH, and 24 h time (64.3%). It was also observed that removal of constituents such as fat, protein, starch, and soluble sugar increased the purity of hemicellulose from 40.2 to 58.2% at the same conditions. After finding optimum hemicellulose yield for practicle use, it was used as edible coating material to prevent darkening of banana fruits and any quality losses. On the fourth day of storage at 4 &ordm / C, there was no detected fungal decay of coated bananas / however, 20% of uncoated bananas (control) were infected. Moreover, the control group lost 5.1% of total weight but coated samples with 1%, 1.5%, and 2% hemicellulose (HC) lost 3.6%, 3.3%, and 3.1% of their total weight, respectively. Hemicellulose coating also protected firmness of bananas (701.1 gf for coated and 509.6 gf for uncoated samples at the end of 4th day). Color was another important quality parameter and it was showed that lightness and yellowness of coated bananas were preserved with very little losses at the end of storage period while control samples turned brown at an unacceptable level. The results indicated that using both low alkaline concentration and low temperature allows to recover higher quality extracts. In addition, hemicellulose showed a characteristic of a good edible coating material for banana in order to preserve their visual acceptance and other quality parameters.
65

Evaluation of the purity and dispersion of single walled carbon nanotubes as potential pharmaceutical excipients

Bagonluri, Mukasa Tenyogtaa 14 May 2010
Single walled carbon nanotubes (SWNTs) are considered potential biomedical materials because of their flexible structure, hollow interior for fluidic transport, propensity for functionalization of the exterior walls, and biocompatibility. Research into exploiting these properties has focused on SWNTs as building blocks for novel drug-delivery systems, dosage forms, and biomedical substrates. However, the use of the internal nanochannels as conduits for trans-membrane drug delivery has not been explored. This research was initially designed to explore the latter.<p> It is postulated that due to their mechanical strength and the presence of an internal conduit, SWNTs can be used for nanofluidic transport. Using a magnetic field, the magnetically responsive SWNT are driven into intact stratum corneum, creating nanochannels, for trans-membrane drug delivery. Initial studies showed however that a bottleneck is the aggregation of SWNTs on the surface of stratum corneum. To achieve trans-membrane nanofluidic delivery, the SWNTs have to be well dispersed in an appropriate pharmaceutical medium, and the SWNT have to be of high purity. Similarly, the presence of impurities in SWNTs, and the dispersion state of these materials in pharmaceutical solvents may give an insight into the discrepancies in toxicity that is reported.<p> The purity of five commercially available SWNTs (AP-SWNT and P2-SWNT, from Carbon Solutions Inc, HMS-SWNT from Helix Materials, and NA-SWNT from Nanostructured and Amorphous Materials Inc. and CT-SWNT from ChepTubes Inc.) were analyzed by raman and electron dispersive x-ray spectroscopy (EDS) spectroscopy. Secondly, the dispersion states of SWNTs in various pharmaceutical solvents were evaluated by ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), dynamic light scattering (DLS), zeta potential, and Raman spectroscopy to identify potential agents for exfoliation of SWNTs in selected pharmaceutical solution.<p> SWNTs were dispersed in various solvents (water, propylene glycol [PG], dimethylsulfoxide [DMSO], and ethanol) as well as in 0.1% w/v aqueous solutions of anionic, cationic and neutral surfactants at a SWNT concentration of 0.1 mg/mL. SWNT suspensions described as dispersed yielded an evenly coloured suspension with no visible precipitate. The most stable dispersions were obtained with the gemini surfactants, which were confirmed by SEM observation of exfoliated SWNTs. Zeta (î) potential measurements of the fully dispersed SWNTs showed typical values of greater than +30 mV, while non-dispersed samples were less than +20 mV. SEM images of the dispersed solution showed the presence of exfoliated SWNTs compared to the aggregated SWNT clusters observed in non-dispersed systems. Raman spectra of dispersed SWNTs showed G-band peak shifts (to higher wavelengths), confirming the presence of exfoliated SWNTs.<p> Even though the purity of SWNT did not correlate with amount of SWNT in dispersion, exfoliation of bundled SWNTs was accompanied by an increase in UV absorbance of the dispersion, with maximum exfoliation determined by a relatively stable UV absorbance.<p> As pharmaceutical excipients, we have demonstrated that gemini surfactants are suitable dispersing agents for SWNTs, and shown that the dispersion of SWNT for gemini surfactants (12-3-12) is achieved below the critical micelle concentration. The dispersion of SWNT bundles into individual strands is the first crucial step towards their use in biological systems as drug carriers.
66

Wideband phase-locked loops with high spectral purity for wireless communications

Lee, Kun Seok 05 July 2011 (has links)
The objective of this research is to demonstrate the feasibility of the implementation of wideband RF CMOS PLLs with high spectral purity using deep sub-micron technologies. To achieve wide frequency coverage, this dissertation proposed a 45-nm SOI-CMOS RF PLL with a wide frequency range to support multiple standards. The PLL has small parasitic capacitance with the help of a SOI technology, increasing the frequency tuning range of a capacitor bank. A designed and fabricated chip demonstrates the PLL supporting almost all cellular standards with a single PLL. This dissertation also proposed a third order sample-hold loop filter with two MOS switches for high spectral purity. Sample-hold operation improves in-band and out-of-band phase noise performance simultaneously in RF PLLs. By controlling the size of the MOS switches and control time, the nonideal effects of the MOS switches are minimized. The sample-hold loop filter is implemented within a 45-nm RF PLL and the performance is evaluated. Thus, this research provides a solution for wideband CMOS frequency synthesizers for multi-band, multi-mode, and multiple-standard applications in deep sub-micron technologies.
67

Evaluation of the purity and dispersion of single walled carbon nanotubes as potential pharmaceutical excipients

Bagonluri, Mukasa Tenyogtaa 14 May 2010 (has links)
Single walled carbon nanotubes (SWNTs) are considered potential biomedical materials because of their flexible structure, hollow interior for fluidic transport, propensity for functionalization of the exterior walls, and biocompatibility. Research into exploiting these properties has focused on SWNTs as building blocks for novel drug-delivery systems, dosage forms, and biomedical substrates. However, the use of the internal nanochannels as conduits for trans-membrane drug delivery has not been explored. This research was initially designed to explore the latter.<p> It is postulated that due to their mechanical strength and the presence of an internal conduit, SWNTs can be used for nanofluidic transport. Using a magnetic field, the magnetically responsive SWNT are driven into intact stratum corneum, creating nanochannels, for trans-membrane drug delivery. Initial studies showed however that a bottleneck is the aggregation of SWNTs on the surface of stratum corneum. To achieve trans-membrane nanofluidic delivery, the SWNTs have to be well dispersed in an appropriate pharmaceutical medium, and the SWNT have to be of high purity. Similarly, the presence of impurities in SWNTs, and the dispersion state of these materials in pharmaceutical solvents may give an insight into the discrepancies in toxicity that is reported.<p> The purity of five commercially available SWNTs (AP-SWNT and P2-SWNT, from Carbon Solutions Inc, HMS-SWNT from Helix Materials, and NA-SWNT from Nanostructured and Amorphous Materials Inc. and CT-SWNT from ChepTubes Inc.) were analyzed by raman and electron dispersive x-ray spectroscopy (EDS) spectroscopy. Secondly, the dispersion states of SWNTs in various pharmaceutical solvents were evaluated by ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), dynamic light scattering (DLS), zeta potential, and Raman spectroscopy to identify potential agents for exfoliation of SWNTs in selected pharmaceutical solution.<p> SWNTs were dispersed in various solvents (water, propylene glycol [PG], dimethylsulfoxide [DMSO], and ethanol) as well as in 0.1% w/v aqueous solutions of anionic, cationic and neutral surfactants at a SWNT concentration of 0.1 mg/mL. SWNT suspensions described as dispersed yielded an evenly coloured suspension with no visible precipitate. The most stable dispersions were obtained with the gemini surfactants, which were confirmed by SEM observation of exfoliated SWNTs. Zeta (î) potential measurements of the fully dispersed SWNTs showed typical values of greater than +30 mV, while non-dispersed samples were less than +20 mV. SEM images of the dispersed solution showed the presence of exfoliated SWNTs compared to the aggregated SWNT clusters observed in non-dispersed systems. Raman spectra of dispersed SWNTs showed G-band peak shifts (to higher wavelengths), confirming the presence of exfoliated SWNTs.<p> Even though the purity of SWNT did not correlate with amount of SWNT in dispersion, exfoliation of bundled SWNTs was accompanied by an increase in UV absorbance of the dispersion, with maximum exfoliation determined by a relatively stable UV absorbance.<p> As pharmaceutical excipients, we have demonstrated that gemini surfactants are suitable dispersing agents for SWNTs, and shown that the dispersion of SWNT for gemini surfactants (12-3-12) is achieved below the critical micelle concentration. The dispersion of SWNT bundles into individual strands is the first crucial step towards their use in biological systems as drug carriers.
68

An analysis of the social relations inwaste management : Two case studies on Somanya and Agormanya in Ghana

Kadfak, Alin January 2011 (has links)
This thesis presents the analysis of how the social relations shape the situation ofwaste management in developing countries. The towns of Somanya and Agormanya,which are both located in the Eastern Region of Ghana, have been selected as casestudies for this thesis. Qualitative research methods were applied to collect theinformation during the fieldwork. The thesis applies different social science concepts,such as the concept of community, gender relations, corruption and space, to analyzethe social relations among the actors within waste management in the two study areas.The thesis aims to look at waste management from a new perspective and seeks tofind better solutions to deal with the waste situation in developing countries.The results obtained from the empirical work presents the relationships of differentactors in the private space and in the public domain. Relationships between membersof the family are analyzed through concepts of gender and cultural structure withinthe private space. Social relations in the public space involve several actors, such astraditional leaders, local officers, the church community and private companies. Theconcepts of state, community and decentralization are applied to explain how theactors relate to each other in waste management.
69

An examination of the purity laws regarding childbirth and menstruation in Leviticus

Province, Diana. January 1994 (has links)
Thesis (M.A.)--Denver Conservative Baptist Seminary, 1994. / Includes bibliographical references (leaves 125-130).
70

Letters from the Goodwill Brothers of Basra : a medieval Islamic message of tolerance and pluralism

Fares, Michael James 31 July 2012 (has links)
“We would never accept the Japanese putting up a site next to Pearl Harbor. There's no reason for us to accept a mosque next to the World Trade Center.”Newt Gingrich said the above words in reference to the recent “ground-zero mosque debate”, a heated media controversy which surrounded plans for the Park 51 Islamic Community Center to open in downtown Manhattan on the 10th anniversary of the September 11th attacks. Assuming a necessary enmity between America and Islam, Gingrich’s claims seem rooted in the theory of a “Clash of Civilizations”. This theory envisions “the West” and “Islam” as diametrically opposed entities with no common values, and has become widely pervasive in informing much of post-9/11 America’s political and academic discourse. When chalked up against the social, cultural, and literary history of Islam, however, the Clash of Civilizations theory is a poor fit. For medieval Arabo-Islamic culture saw a vast rise of humanistic literature bearing a clear multi-civilizational influence. The Letters of the Goodwill Brothers of Basra constitute one of the most overlooked of these works. Composed by a group of 10th century Abbasid Muslim littérateurs, the 52 Letters draw parallels between the teachings of Islam and those of prior great wisdom traditions, including Indian and Ancient Greek wisdom, Judaism, and Christianity. Focusing on the way the Letters frame Islam in the context of perennial human wisdom, I show how this text is ultimately an irenic text aimed at promoting religious tolerance and cooperation in the tumultuous sectarian atmosphere of 10th century Abbasid Iraq. I argue ultimately that the irenic message of the Letters presents an alternative narrative to the Clash of Civilizations theory, a narrative of tolerance from the Islamic past by which our own society may benefit when it comes to the relationships between American Muslims and non-Muslims. / text

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