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1
Sanga, Alvin. "Superintendent Turnover in Guam." Thesis, Loyola Marymount University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10622159.
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Superintendent turnover has been rampant in the public school district in Guam, an unincorporated United States territory; there have been 18 superintendents since the 1981. This qualitative study aimed to identify and analyze potential factors affecting the superintendency in Guam. Social systems theory proposes a number of factors about the dynamics that define the relationship between an individual and a social system to help us understand the behavior of the individual within an organization. To triangulate the data, this study was comprised of individual interviews with Guam superintendents and content analysis of the Guam Public School Audit of 2009 and subsequent amendments made to board policies after the audit. Based on social systems theory, major findings suggest that superintendent turnover in Guam is influenced by the following: the Guam Education Board did not understand its roles and responsibilities and often micromanaged the superintendents; the budgetary process for the Guam Department of Education was stressful and problematic; and political pressures from the legislature and the governor encouraged superintendents to take other roles. Suggestions for improving stability within the superintendency of Guam were offered by former superintendents.
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Cruz, Felicity M. F. "Parents decisions regarding childcare: the Guam perspective." Thesis, University of Hawaii at Manoa, 2003. http://hdl.handle.net/10125/6931.
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Stephen, David V. M. "Progenic isonymy among the Chamorro of Guam." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/289753.
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This study examines several methodological issues pertaining to the application of isonymy techniques to a historical population located on the island of Guam in Micronesia. Since European contact the indigenous Chamorro population of Guam has undergone a series of precipitous population declines. The Spanish colonial administration imposed a dual surname system on the Chamorro. The surname information was compiled into a demographic database representing approximately 39,000 persons traced from late 19th century vital records. Analysis using the methods of isonymy was conducted on lineages established from the four parental surnames. Values were calculated from the progeny in the database, in effect focusing on the effective breeding population. Comparisons were made with inbreeding values obtained using other methods of surname analysis both for single and dual surname systems. In contrast to the paternal lineage, the values for the other lineages were influenced by their shallow temporal depth. The non-paternal lineages showed patterns of assortative mating reflecting choices of mate selection that have the potential to influence levels of inbreeding in the population.
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Salas, Marilyn Camacho. "The relationship between classroom participation structures and fourth-grade Guamanian students' reading comprehension." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185534.
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The purpose of this study was to explore the relationship between lesson interaction patterns and fourth-grade Guamanian students' reading comprehension. In the last decade, a variety of new approaches have emerged in the field of education that extend our ability to better understand the teaching-learning process. These approaches allow close and detailed examination of how teachers and their students interact in creating classroom settings, particularly as they refer to reading lessons. The present study continued the investigation of classroom participation structures and their relationship to reading comprehension in a multilingual and multicultural setting. Three reading discussion lessons were observed and audio- and videotaped in four, fourth-grade classrooms in Guam during the months of November 1989 to April 1990. Of the three discussion lessons, one was selected for in depth analyses. Students were in the Level 11 reading group of the Silver Burdette-Ginn Basal Reader Series. Teachers were instructed to teach their lessons according to their usual procedures. No attempt was made to alter delivery of instruction. From transcriptions of the audio- and videotapes, Mehan's (1979) procedures were used to describe turn-allocation and speech act procedures. In addition, retellings were analyzed utilizing the retelling profile developed by Mitchell and Irwin (1991). Although the study was conducted in schools with bilingual, multicultural and multilingual teachers and students, the participation structures found in these Guam classrooms appear no different from the participation structures found in most American classrooms. In terms of the questions being explored in this dissertation, sensitivity to the linguistic and cultural background of Guamanian students was not evident. The results of the qualitative and quantitative analyses of the data pointed to three major findings. First, variability existed in the participation structures found in the four, fourth-grade reading discussion lessons. Second, there were minimal differences in participation structures when teachers who adhered closely to basal reader material and instruction were compared with teachers who did not adhere as closely to basal reader material and instruction. Third, the study suggests that the participation structures found in the four, fourth-grade reading discussion lessons were related to the reading comprehension of these fourth-grade Guamanian students.
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Cruz, Anna Maria, and Anna Maria Cruz. "Patient Satisfaction with Nurse Practitioner Care on Guam." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/623005.
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Patient satisfaction has been identified as an indicator of quality care. There is no research on patient satisfaction with Nurse Practitioner (NP) care on Guam. Therefore, a cross sectional descriptive study was conducted to assess patient satisfaction with NP care at three primary care clinics on Guam. A convenience sample of patients 18 years and older, seen by an NP were invited to participate in completing the Nurse Practitioner Satisfaction Survey (NPSS). Data collection concluded after a one-month period (N = 108). Descriptive statistics, between group differences, and correlational analyses were conducted. Participation in the survey was voluntary and anonymity, confidentiality, and privacy were ensured. General patient satisfaction was very high for NP care on Guam. "My NP is caring" was the highest scoring item on the NPSS with a mean score of 4.43 (n=56). Participants selected the NP as providing the health education and care the patient found most satisfying. A statistically significant weak negative correlation between patient satisfaction and age and level of injury was found. Singles reported significantly higher patient satisfaction scores than widowers. Study limitations included the small sample size, convenience sampling, social desirability and selection bias. Caring is an essential tenet of NP care and patient satisfaction. Improving NP role clarity is vital to the continued success and growth of the NP profession. The value that NPs bring to primary care is substantiated by the high patient satisfaction levels consistently produced from studies across the globe. In order for NPs to significantly impact the primary care provider shortage all 50 states and the US territories must enact full practice authority (FPA).
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Torsch, Vicki L. "The elderly experience among the Chamorros of Guam /." Full-text version available from OU Domain via ProQuest Digital Dissertations, 1996.
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Stade, Ronald. "Pacific passages : world culture and local politics in Guam." Doctoral thesis, Stockholms universitet, Socialantropologiska institutionen, 1998. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-45875.
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Canos, Ronald A. S. "Mentoring Experience Perceptions of Career Changing Teachers on Guam." ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/4718.
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Teacher attrition continues to impact public schools that seek to retain teachers in the classroom and meet rising enrollment rates. The recruitment of experienced career changing professionals into the educational workforce is a viable option to address teacher shortages. In addition, while the use of mentorship may support teacher retention and job satisfaction for novice teachers, inconsistencies in mentoring practices have limited the effectiveness of mentoring programs and support systems. The problem of limited research that examines the needs of career changing teachers (CCTs) and their initial mentoring experiences was addressed in this study. The social learning theory and Maslow's hierarchy of needs frameworks were used in this phenomenological study to explore perceptions of 15 novice CCTs from the middle or high school levels, who had completed 1 to 5 years of teaching service. The research questions focused on CCTs' perceptions of their mentoring experience, and the support they needed as novice teachers. Data collected from 2 rounds of semistructured interviews were analyzed with a multilevel coding approach to identify patterns and emergent themes. Emergent themes revealed CCTs' experiences and skills as viable teaching candidates, perceptions of their mentoring experiences, and support and retention needs. The findings revealed CCTs' desire for support in mentorship availability and quality, improvement in instructional pedagogy, and the promotion of emotional resiliency and job satisfaction. Recommendations point to the need for mentorship as ongoing practice, the personalization of mentorship programs, and the leveraging of professional development practices to provide mentoring support. The major implications for social change are the improvement of mentoring program design and the implementation for the development and retention of highly effective teachers to impact student achievement.
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Dela, Cruz Cristina Maria B. "Existential Concerns of Individuals Living with Chronic Mental Illness in Guam." Antioch University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1372443327.
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Smith, Sarah Ann. "The Reproductive Lives of Chuukese Women: Transnationalism in Guam and Chuuk." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5311.
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Chuuk, one state of the Federated States of Micronesia (FSM), experiences significant transnational migration to the United States (U.S.), particularly to the Territory of Guam. This migration is facilitated by the Compact of Free Association (COFA), an agreement with several Micronesian countries previously under U.S. administration that allows for free movement of their citizens into the U.S. Although part of Micronesia, Guam's colonized residents resist an identity connected to rest of Micronesia. With very poor health outcomes, the Chuukese represent a political and social body of bodies that bring sickness, babies and increased costs to the Guam government without adequate compensation by their colonizer sanctioning the migration. In order to better understand why Chuukese women suffer disproportionately poor reproductive health outcomes as compared to the rest of Guam's residents, this multi-sited dissertation examines how Chuukese women's reproduction is constructed and conceptualized by women, their families, and their "home" and "host" communities, and how these meanings are mediated by transnational migrant experiences between Chuuk and Guam. Using a critical interpretive framework, this study utilized participant observation in the clinics and communities, interviews with health care workers, and in-depth life history interviews with fifteen Chuukese women. This dissertation situates Chuukese women's reproduction in the context of transnational migration through an analysis of social, economic and political processes, health and social services policies and practices, postcolonial migration and sociocultural meanings of reproduction for Chuukese women in both Chuuk and Guam.
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Storie, Monique. "All Fifty Kathousand Cousins: Chamorro Teachers Responding to Contemporary Children's Literature Set in Guam." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/145709.
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Grounded in Rosenblatt's transactional theory and Pacific literary theory, this qualitative case study looked at Chamorros teachers' responses to contemporary fiction books as a way of exploring cultural authenticity within a recently emerging genre of children's books. Nine teachers read and responded to eight books that presented a variety of character types, settings, and social issues related to the island of Guam. Guided by three research questions, this study explored what artifacts, images or depictions reflected the lived experiences of the contemporary Chamorro people. Data (transcripts of interviews, literature discussions and participant-generated artifacts) was collected from teachers in a professional development course on children's literature and from individual meetings. Using inductive analysis, the teachers' responses were examined for recurring themes, concepts and words that focused on their personal connections with the books, their cultural understandings, and their perceptions of the portrayal of the Chamorro culture. The teachers' connections drew attention to the ways in which they attempted to use their knowledge about the Chamorro culture to make sense of the stories they read. The teachers' responses to the stories demonstrated that they were making connections to those representations that emphasized and honored their Pacific identity, such as the extended family and how certain traditional practices symbolize the resiliency of the Chamorro people. They also demonstrated how rich cultural images served as prisms that revealed layers of cultural understandings. Finally, the teachers' responses revealed that their decisions regarding the authenticity of a book were mediated by their personal senses of culture as well as by a communal ideology. Not only does this study highlight culturally appropriate representations of the Chamorro people, it also sheds light on the relationship between cultural elements in a story and a culture's value system, and how these two influence the meaning that a reader finds within the story. By highlighting how readers home in on the subtleties of cultural depictions, this study demonstrates how the issue of cultural authenticity can best be understood as a complex matrix of cultural images, a community's value system and personal experiences.
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McCann, Sarah C. "Atmospheric influences on cave meteorology, Jinapsan Cave, Guam| A drip rate analysis." Thesis, Mississippi State University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1536130.
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Temperature, pressure, and relative humidity within Jinapsan Cave on Guam were compiled and analyzed over a five-month period to gain a better understanding of this environment. Temperatures within the cave hover around ~26°C with no apparent influences except the mean annual temperature, with humidity values over 90%. There is high fidelity between outside and internal air pressures indicating no pressure differential exists and pressure changes are a result of kinematic wave flow. A mild correlation exists between a cave speleothem's drip rate and outside pressure. The cave's tidal pool compared to oceanic tides show a lag of 1-2 hours and amplitude dampening. The tidal pool's temperature is 25.7°C, signifying no mass transfer of water occurs. Tropical cave studies are rare, but are important for paleoclimate research using cave speleothems as proxies. This study determined cave meteorological factors that affect speleothem development to allow for more accurate paleoclimate studies.
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Bevacqua, Michael Lujan. "Chamorros, ghosts, non-voting delegates GUAM! where the production of America's sovereignty begins /." Diss., [La Jolla] : University of California, San Diego, 2010. http://wwwlib.umi.com/cr/ucsd/fullcit?p3398029.
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Thesis (Ph. D.)--University of California, San Diego, 2010.Title from first page of PDF file (viewed May 5, 2010). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (leaves 447-492).
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Schulze, Dana Verfasser], and Reinhard [Akademischer Betreuer] [Meyers. "Leaving Russia's Backyard : GUAM and the Challenge of Integration / Dana Schulze ; Betreuer: Reinhard Meyers." Münster : Universitäts- und Landesbibliothek Münster, 2016. http://d-nb.info/1141233703/34.
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Santos, Robert D. (Robert David). "Faculty and Administrators' Job Preferential and Job Satisfaction Factors at the University of Guam." Thesis, University of North Texas, 1990. https://digital.library.unt.edu/ark:/67531/metadc331097/.
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Research into job preference and job satisfaction addresses the agreement between individual and institutional values leading to job choice and job satisfaction. This research assessed ten job preference and ten job satisfaction factors at the University of Guam. Ninety-one faculty members and 32 administrators completed a two-page paired-comparison questionnaire. Demographic data were also collected.
Factors' hierarchy and valence positions were reported and subjected to "PCSTATS" program to determine significance among pairs. Significant differences existed in three of the four hypotheses measuring the job preferential factors: advancement, benefits, company, co-workers, hours, pay, security, supervisor, type of work, and working conditions; and job satisfaction factors: good wages, job security, interesting work, tactful disciplining, in on things, working conditions, management loyalty, appreciation, promotion, and sympathetic understanding. Additional findings were made using post hoc analysis.
Results indicated that administrators perceived others' preferences to be (a) pay, (b) advancement, and (c) type of work while faculty chose (a) type of work, (b) pay, and (c) advancement. In job satisfaction administrators selected (a) promotion, (b) good wages, and (c) job security, while the faculty chose (a) interesting work, (b) good wages, and (c) promotion. Self job preference factors chosen by males and females were (a) type of work and (b) pay with (c) advancement and (c) co-workers, respectively. The top three self job satisfaction factors chosen by males and females were (a) interesting work, (b) good wages, and (c) promotion.
Disagreement is evident between groups. It is recommended that the findings be used in the selection and retention of faculty members at the University of Guam.
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Indalecio, Agnes Rose Espinosa. "Policies and practices of Chamorro cultural narratives in the community and schools of Guam." Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/284054.
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In this study, I use aspects of ethnography to explore the role of cultural narratives in the educational experiences and daily life of the Chamorro people. The major method of collecting the data used in this study included official documents, interviews, and written surveys. These different sets of data collection allowed me to cross-check the data to triangulate the evidence and to refine and validate the study. The Chamorro culture and language still exist. However, the majority of homes are practicing an Americanized lifestyle because of the influences from the United States since their invasion in the 1800s. There has been a shift from the teaching of the history, culture, language, values, and stories of the Chamorro people from the home to the school. Data show that informants agree that teachers across all disciplines should implement cultural narratives into their teaching. The University of Guam and the Guam Community College need to add courses specializing in the Chamorro culture and make this part of the requirements for earned degrees in Elementary, Secondary, and Special Education. Participants agree that cultural narratives support Chamorro values and should be visible in all public and private schools from kindergarten through higher education. The main conclusions include (1) Guam does not have a set written policy for Chamorro cultural narratives although it is an accepted and recognized part of the Chamorro curriculum, (2) the Chamorro cultural narratives should be emphasized more and expanded across the standard curriculum for all grade levels, K-12, (3) the community, the family and the school must work more collaboratively and find more innovative ways to maintain the language and culture of the Chamorro people, and (4) Chamorro narratives should be implemented in both public and private schools.
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Cruz, Teofila Sholing, and Teofila Sholing Cruz. "Breast Cancer Risk Perception, Knowledge, Attitudes, Beliefs and Screening Behaviors of Chamorro Women in Guam." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/626643.
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Background: Breast cancer is a serious public health issue in Guam and in the world. Chamorro women in Guam have the highest incidence and mortality rates of breast cancer among other ethnic groups of women living in Guam. Early detection reduces breast cancer morbidity and mortality. Little is known regarding factors associated with Chamorro women’s breast cancer screening behaviors.
Purpose: This qualitative descriptive study was designed to obtain a straight forward description of perspectives and insights of Chamorro women in Guam ages 45 – 65 years, about their breast cancer risk perception, knowledge, attitudes, beliefs and breast cancer screening behaviors.
Sample: A purposeful sample of 15 participants yielded broad insights and rich data regarding breast cancer risk perception, knowledge, attitudes, beliefs and breast cancer screening behaviors of Chamorro women. The sample size was determined by “data saturation”.
Methods: The researcher conducted four focus group interviews to gain broad insight using open-ended questions. Interviews were audio-recorded, transcribed and analyzed using qualitative content analysis.
Findings: Data analysis ascertained the following categories: risk perception, knowledge, attitudes, beliefs, behaviors including motivators, benefits and barriers towards breast cancer screening. Identified subcategories: perceived breast cancer risk as multiple family members’ diagnoses of breast cancer. Breast cancer knowledge was sparse with responses addressing not knowing about breast cancer, however, participants alluded that early detection towards breast cancer was the key to breast cancer screening. Cultural beliefs in suruhana/suruhano was not causing or treat cancer. Staying healthy by eating healthy foods and exercising were behaviors in living a healthy life as a breast cancer screening behavior. Screening motivators were knowing family or friends with breast cancer, mammogram reminders, and having a health insurance coverage. Overall there was a consensus of the benefits of mammogram and the need for early detection notwithstanding barriers such as painful mammograms, hurtful comments from health care providers.
Conclusion: Findings contributes to literature and future studies about Chamorro women breast cancer risk perception, knowledge, attitudes, beliefs and behaviors as well as motivators, benefits and barriers to breast cancer screening. The study contributes to nursing knowledge and practice in understanding breast cancer in women and their families within the social context as Chamorros.
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Crisson, Kevin, Jason Grammar, and Peter Leestma. "Sea water air conditioning (SWAC) at Naval Base Guam: cost-beneit analysis and acquisition strategy." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/44542.
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Approved for public release; distribution is unlimitedThe purposes of this research are to determine whether it is financially feasible and attractive to install sea water air conditioning (SWAC) at Naval Base (NB) Guam, which the Naval Facilities Engineering Command currently deems to be true; to develop an acquisition strategy that NB Guam would be able to use to procure a SWAC system; and to identify any environmental obstacles associated with installing a SWAC system at NB Guam. This includes environmental impact studies and potential long-term schedule effects of environmental research. This research provides the analytic underpinning for the SWAC-driven reduction of electricity consumption at a significant number of naval facilities, and it provides a significant contribution towards meeting the Secretary of the Navy’s renewable energy goals.
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Regis, Jamar. "Examining the Spatial and Temporal Variations in CO2 Partial Pressure in the Deep Vadose Zone Above Jinapsan Cave, Guam." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7904.
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Carbon dioxide is the primary driver of dissolution and precipitation reactions in epigene limestone caves. While much work has been conducted on CO2 dynamics involved in dissolution in the phreatic zone, less research has been conducted on vadose CO2 dynamics, especially in tropical caves developed in eogenetic limestones. In this study, we investigate spatial and temporal variation in pCO2 in the deep vadose zone of eogenetic limestone above Jinapsan Cave, located in northern Guam. Five years of carbonate chemistry data from three dripwater sites in Jinapsan Cave (Flatman, Station1, and Trinity) were used to model the theoretical pCO2 with which infiltrating waters had likely equilibrated along flow paths between the soil and the cave. Theoretical pCO2 essentially models the amount of CO2 that would need to be added to dripwaters that have degassed and become supersaturated with respect to calcite upon entering a lower CO2 cave void in order to return the water to equilibrium. Theoretical pCO2 values range from 10-2.8 to 10-1.8 atm among the three sites examined. These results were generally lower compared to similar studies in telogenetic and continental karst, which range from 10-3.7 to 10-0.96 atm. Theoretical pCO2 data from Jinapsan Cave have significant differences among the three drip sites, with the site closest to the entrance (Flatman) having the highest values and the farthest from the entrance (Trinity) having the lowest values; in addition, the values also have a great seasonal variability. Low theoretical pCO2 values in Jinapsan Cave’s dripwaters indicate that vadose zones in eogenetic limestone may be better ventilated, and hence have lower pCO2, than those in telogenetic limestone. The ventilation of the vadose zone is facilitated by high matrix porosity and permeability of eogenetic limestone and may be driven by barometric pressure changes or wind.
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Fanning, Jonathan. ""We flow like water"| Contemporary livelihoods and the partitioning of the self among the Chamorro of Guam." Thesis, Colorado State University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1590564.
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The Chamorros of Guam have experienced colonially-influenced change on spatial and temporal scales for nearly four-hundred and fifty years. They are continuously redefining their identity with respect to these changes, and within the power related discourses of colonialism. The adoption of a colonial understanding of "tradition" has alienated Chamorro from their perception of indigenous identity. A difference between a contemporary "livelihood" and a more traditional "way of life" is apparent, also considered to be a conflict between how a Chamorro "must" behave versus how a Chamorro "ought" to behave to maintain an indigenous identity. Lack of agency, the rise of individualism, and the institutionalization of Chamorro culture have compartmentalized Chamorro identity, and forced contemporary Chamorro to abandon that which is "traditional" in order to engage with a modern world.
This thesis explores these phenomena through a mixed-methods lens, employing participant observation, semi-structured, qualitative interviews, and surveys to explore the domains in which Chamorro draw meaning and personal and cultural identity. The village of Umatac, on the southern-end of Guam, is used as a study population, as the issue of identity formation and remaking is explored through the theoretical perspectives of cognitive anthropology, discursive formation, and place attachment.
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Stafford, Glen T. "Analysis of Department of Defense (DOD) transportation mode strategies for shipping fresh fruits and vegetables (FFV) to Guam." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA343442.
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Demeterio, Erlinda Luz T. "Relationships among selected demographic, business-related and life satisfaction characteristics of homebased and otherbased business owners in Guam /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487847761306605.
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Santana-Bendix, Manuel Alberto 1956. "Movements, activity patterns and habitat use of Boiga irregularis (Colubridae), an introduced predator in the island of Guam." Thesis, The University of Arizona, 1994. http://hdl.handle.net/10150/278430.
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Boiga irregularis has caused the extinction of several native vertebrate species on the island of Guam. Information on movement is critical to the management of the species. B. irregularis is active at night and spends daylight hours in secluded refuges (from 10 m up in the forest canopy to 1 m underground). There appears to be no preferences for any particular refuge type. Nighttime movement (distance) was related to distances between daytime refugia. The average net movement ranged from 26.9-97.7 m/day (N = 11). The maximum distance moved from the first daytime location following release to subsequent locations ranged from 142.8-1809.4 m. The activity area (minimum convex polygon) ranged from 1.9-99 ha; the cumulative activity area periodically increased and did not reach an asymptote. Direction of snake movements were random. The data suggest that Boiga lacks a defined activity area, and moves randomly and continuously searching for resources.
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Anderson, Nancy L. "Thermal preferences, metabolic rate, and water flux of the Brown treesnake (Boiga irregularis) in the laboratory and on Guam /." The Ohio State University, 2002. http://wwwlib.umi.com/dissertations/fullcit/3039442.
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Murphy, Helen Elizabeth. "The influence of leaf canopy on seed and gum yield of guar (Cyamopsis tetragonoloba [L.] Taub.) /." [St. Lucia, Qld.], 1998. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16303.pdf.
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GASTONE, FRANCESCA. "Guar gum improves the stability and the mobility of iron microparticles for groundwater remediation." Doctoral thesis, Politecnico di Torino, 2014. http://hdl.handle.net/11583/2549542.
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Contaminated sites managements represents in Europe one of the most serious issues.
Recent data of the European Environmental Agency (EEA) shows how soil contamination due
to industry, garbage warehousing, mining and hydrocarbons tanks leakage represents one of
the most important threats to the environment [1].
The large volume of waste and the intense use of chemicals during past decades have
resulted in numerous contaminated sites across Europe. Contaminated sites could pose
significant environmental hazards for terrestrial and aquatic ecosystems as they are
important sources of pollution which may result in eco toxicological effects [2]. Emissions of
hazardous substances from local sources could deteriorate soil and groundwater quality. Soil
contamination is mainly located close to waste land-fills, industrial/commercial activities
diffusing heavy metals, oil industry, military camps, and nuclear power plants.
The objective of relevant EU policies is to achieve a quality of the environment applying
successful technologies. To this purpose, in the last decade EU have been financed numbers
of international, multi-partner EU projects; among them, the large scale research project
AQUAREHAB (FP7 ENV 2008.3.1.1.1.) , coordinated by VITO (Belgium) and involving 19
partners, started in May 2009 and lasted 56 months, until 2013. It aimed at developing
innovative rehabilitation technologies for soils, groundwater and surface waters
contaminated by a wide range of priority contaminants (nitrates, pesticides, chlorinated
compounds, aromatic compound, mixed pollutions, ecc.). These technologies have been
developed within 5 operative work packages (WP1-5) and the guidelines and approaches
developed have been extrapolated and applied, in WP8, to real polluted sites.
The work herein presented is included in the context of WP5 and WP8 of the AQUAREHAB
EU project, in which the group of Groundwater Engineering of the Polytechnic University of
Turin is involved; its goal is to develop and apply at the real scale an effective and costeffective in-situ rehabilitation technology based on the injection of micro-sized (100 nm-100
µm) zerovalent iron (MZVI) particles directly into a contaminated aquifer in order to create a
reactive zone which is able to treat both the plumeand the source of contamination.
Injectable MZVI particles are selected because they can overcome the major hindering
factors of the widely accepted ZVI based permeable reactive barriers (PRB) (impossibility to
treat the source of contamination and considerable excavation costs), due their high
reactivity against a wide range of contaminants thanks to their high specific surface area and
to lower costs, longer lifetime and easier handling in respect with nano-sized ZVI (NZVI)
particles. Nevertheless MZVI particles disperse in water are prone to gravitational instability
and, as a consequence, the resulting mobility is limited [3, 4]. To solve this problem, the use
of a stabilizing agent able to modify suspending fluid properties is required. In the recent
year the use of biopolymer demonstrated to be successful [5, 6] although a full
comprehension of interaction mechanisms with the porous media and a complete system
characterization is still missing.
In this work, in order to meet AQUAREHAB project requirements and to overcome
technology limitations, the use of MZVI suspended in a thickening polymer solution of guar
gum hydrocolloid is considered.
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Sanchez, Gil Yaritza M. "Characterization and rheological properties of Camelina sativa gum: interactions with xanthan gum, guar gum, and locust bean gum." Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/32789.
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Master of ScienceDepartment of Biological & Agricultural Engineering
Donghai Wang
Gums are water-soluble polysaccharides used in many industrial and food applications because of their functions such as thickening, gelling, emulsification, adhesion, and encapsulation. Interactions between gums are conducted to enhance functional properties of finished products and reduce processing costs. In this study, camelina gum, from the oil-seed plant Camelina sativa, is characterized by carbohydrate composition and morphological, thermal, and rheological properties. Interactions with xanthan gum, galactomannans guar gum, and locust bean gum (LBG) are also studied. Camelina gum is composed of arabinose, rhamnose, galactose, glucose, xylose and mannose; according to high-performance anion exchange chromatography analysis. Scanning electron microscopy and transmission electron microscopy images showed camelina gum with fibrillar structure and intermeshed network. Camelina gum solutions exhibited a shear thinning flow behavior in a range of concentrations (0.1% to 2.0% w/w) and shear rate (0.001 sˉ¹ to 3000 sˉ¹). Camelina gum is temperature independent at temperature ranges from 4 °C to 90 °C. The apparent viscosity increased as gum concentration increased. Mechanical properties of camelina gum demonstrated viscoelastic behavior with entangled molecular chains. Interaction of camelina gum with monovalent salt NaCl significantly reduced the viscosity of camelina gum solution at 1% when NaCl concentration increased. Camelina gum is soluble in water up to 60% ethanol content, in which the rheological properties do not significantly differ from camelina gum in water solution only. A synergy with xanthan and galactomannans was determined. All mixtures exhibited shear-thinning flow behavior, solid-like behavior at low frequencies, and liquid-like behavior at high frequencies. For camelina-galactomannans mixtures, synergistic interactions occurred in LBG-camelina mixtures at ratios of 1:1 and 3:1. For xanthan-camelina mixture, maximum synergy was observed at the ratio 1:1. Synergistic effects of gum mixtures suggest dependency on the ratios and chemical structures of the gums. The effect of temperature on apparent viscosity of mixtures is not significant. Results showed that camelina gum can be used for commercial applications.
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Al-Shehry, Jaber Mohammed. "EFFECT OF GUAR GUM ON VEGETABLE TRANSPLANT GROWTH." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275440.
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Husman, Stephen Herbert 1954. "IRRIGATION TIMING AND PLANTING DATE EFFECT ON GUAR SEED YIELDS." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275476.
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Dalisay, Francis Sapiandante. "Information use, attitude formation, and opinion expression concerning the U.S. military buildup on Guam the effects of colonial debt, pro-local stances, and conflict avoidance /." Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Dissertations/Spring2010/f_dalisay_020210.pdf.
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Thesis (Ph. D.)--Washington State University, May 2010.Title from PDF title page (viewed on June 4, 2010). "Edward R. Murrow College of Communication." Includes bibliographical references (p. 110-126).
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Barratt, Emma Elizabeth. "The isolation, purification and characterisation of an alkaline alpha-galactosidase from a thermophilic bacterial consortium." Thesis, Cranfield University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341047.
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Young, Niall William George. "The solution properties of hydrophobically modified guar gum derivatives." Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360604.
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Kellar, Debra Meridith Mokaren. "The Examination of Vehicle Related Flood Fatalities in the United State, Commonwealth of Puerto Rico and the U.S. territories of the Virgin Islands and Guam: 1995-2005." Kent State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=kent1290537007.
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Souther, Brandy Jolene. "The Effect of Xanthan Gum and Guar Gum on Enhancing the Quality and Preventing Lipid Rancidity in Yeast Bread Supplemented with Flaxseed." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/43920.
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This study examined the effects of guar gum and xanthan gum on flax supplemented breads through objective and sensory testing. Breads containing flaxseed and gums were found to have a significantly (p<0.05) higher water activity than the control bread. Control bread was also found to have a higher (p<0.05) volume while flax breads containing guar gum had a significant (p<0.05) decrease in volume. Control bread and bread containing guar gum were significantly (p<0.05) harder in crumb texture. Breads with flax and xanthan gum displayed a significant (p<0.05) amount of springiness. While there was no significant (p>0.05) difference in peroxide values among bread samples, control bread had a lower (p<0.05) anisidine value indicating a decrease in hydroperoxide breakdown. While not significant (p>0.05), bread containing xanthan gum had a lower anisidine value than the other treatments. Sensory analysis found bread with both gums to be moister (p<0.05) and have a strong (p<0.05) yeasty aroma and fresher flavor. Control bread was found to have the least (p<0.05) yeasty aroma and taste significantly (p<0.05) less bitter but more stale.Master of Science
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Ma, Xiaodong. "Lyotropic ion effects in guar gum adsorption on various minerals." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31419.
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Adsorption of guar gum was studied on a number of oxide and clay minerals. The tests were performed as a function of salt concentration and pH from solutions of lithium, sodium, potassium, and cesium chlorides. The four salts allowed an assessment to be made of the significance of lyotropic ion phenomena in controlling the adsorption of the polysaccharide. The results showed that the adsorption of the polymer was independent of pH and acidity/basicity of the minerals. Therefore, no evidence of acid-base type of chemical interactions was observed and hydrogen bonding was suggested as the adsorption mechanism. It was also observed that the adsorption of guar gum on quartz, kaolinite and illite proceeded differently from lithium and sodium chloride solutions in comparison to potassium and cesium chlorides. In contrast, no significant effect of salt type and concentration was observed in guar gum adsorption on titania, hematite, and alumina. It was postulated that the presence or absence of an extensive hydration layer at the mineral-solution interface was the dominant factor and that the interfacial water created a barrier against guar gum adsorption. Therefore, the role of ions of a given lyotropic series is to destabilize the interfacial water structure and promote guar gum adsorption. On the other hand, the absence of an extensive hydration layer on titania, alumina, and hematite allowed guar gum to freely interact with the surfaces and thus no lyotropic ion effect was observed. Therefore, lyotropic ion effects are very strong only in the case of strongly hydrated quartz and, apparently, clay minerals. It was also shown that guar gum undergoes extensive aggregation in concentrated solutions of kosmotropic salts (LiCl and NaCl) while chaotropic potassium and cesium chlorides turned out to be very powerful solvents for the polymer. As a result, it can be postulated that individual guar gum molecules adsorb on minerals from concentrated KCl solutions, while entire guar gum aggregates adsorb from concentrated NaCl solutions. Such findings are of particular interest to potash flotation which is carried out in saturated salt solutions. It was stressed that any analysis of the adsorption results using traditional approaches and models must be performed with extreme caution since guar gum solutions are inherently heterogeneous due to the presence of undissolved, colloidal polymer aggregates.Applied Science, Faculty of
Mining Engineering, Keevil Institute of
Graduate
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Bergecliff, Terese. "Viscosity and Acid Stability in Low-fat Mayonnaise with Varying Proportions of Xanthan Gum and Guar Gum." Thesis, Linnéuniversitetet, Institutionen för kemi och biomedicin (KOB), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-57484.
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Mayonnaise is a mixture of egg yolk, vinegar, water, spices and 70-80% oil forming a semi-solid oil-in-water emulsion. When preparing a low-fat mayonnaise with an increased water content, thickening agents are required for increased viscosity and emulsion stability. The hydrocolloids xanthan gum and guar gum are sometimes used for this purpose and they act synergistically creating a viscosity increase. However, guar gum has poor acid stability, and because mayonnaise is an acidic product guar gum will eventually start to degrade causing a viscosity decrease and subsequent emulsion separation. Despite this fact, guar gum and xanthan gum are extensively used in mayonnaises today. The aim of this degree project was to explore how the synergy between guar gum and xanthan gum influences the viscosity of a low fat mayonnaise and whether high acidity will have an impact on the viscosity over a 4-week period. This was to examine if and if so, how a mayonnaise recipe can be modified to maintain a cost efficient product with the desired rheological properties in times of hydrocolloid price fluctuations. The study was conducted by preparing 15 mayonnaises with 50% fat, either at pH 3,5; 4 or 5 and a total of 0,6 % hydrocolloids with varying proportions of guar gum and xanthan gum. The mayonnaise samples were studied by measurements of viscosity, color changes and a visual comparison of their mayonnaise-like flow-properties compared to Hellmann’s Real Mayonnaise used as reference. The viscosity of the mayonnaises increased with increasing ratio of guar gum. On the other side, there were greater viscosity losses in mayonnaises with increasing ratio of guar gum 4 weeks after preparation compared to 4 days, with no apparent signs of correlation between higher acidity and hydrocolloid degradation. Mayonnaises with 20% xanthan gum and 80% guar gum had the texture most similar to the reference. In these low-fat mayonnaises, the use of more xanthan gum led to an undesired “slimy” texture and a lower viscosity – an important aspect if adjusting a low-fat mayonnaise recipe by increasing the ratio of xanthan gum. Because a commercial mayonnaise sometimes is consumed several months after manufacturing, that time frame is most likely required in order to fully measure how much the high acidity in mayonnaise will affect its viscosity. This project has shown a pattern where viscosity in the assessed mayonnaises starts to decrease a few weeks after preparation. However to find out exactly to what extent and how this would affect the overall product, and ultimately: if guar gum/xanthan gum combinations are suitable for long-term mayonnaise applications, further studies are required.Viskositet och syrastabilitet i majonnäs med låg fetthalt och olika proportioner av xantan och guarkärnmjöl Majonnäs är en blandning av äggula, vinäger, vatten, kryddor och 70-80% olja som bildar en semi-solid olja-i-vatten-emulsion. För att tillverka en lågfettsmajonnäs med högre vatteninnehåll behöver förtjockningsmedel tillsättas för viskositet och emulsionsstabilitet. Hydrokolloiderna xantangummi och guarkärnmjöl används ibland i detta syfte och de utövar en synergi som ger ökad viskositet. Dock har guarkärnmjöl dålig syrastabilitet och eftersom majonnäs är en sur produkt kommer guarkärnmjölet efter ett tag att brytas ned vilket leder till en viskositetsminskning och emulsionsseparation. Trots detta används guarkärnmjöl och xantangummi i stor utsträckning i majonnäser idag. Syftet med examensarbetet var att undersöka hur synergin mellan guarkärnmjöl och xantangummi påverkar viskositeten i en lågfettsmajonnäs och huruvida en hög syrahalt kommer att påverka viskositeten under en 4-veckorsperiod. Detta för att se om och i så fall hur ett majonnäsrecept kan modifieras för att erhålla en kostnadseffektiv produkt om priset på hydrokolloider växlar. För arbetet bereddes 15 majonnäser med 50% fetthalt, antingen med pH 3,5; 4 eller 5 och totalt 0,6% hydrokolloider med olika proportioner av guarkärnmjöl och xantangummi. Majonnäserna undersöktes genom mätning av viskositet, färgförändringar och en visuell jämförelse av deras majonnäsliknande flytegenskaper i förhållande till Hellmann’s Real Mayonnaise som användes som referens. Viskositeten i majonnäserna ökade med ökande halt guarkärnmjöl. Å andra sidan minskade viskositeten i högre grad med ökande halt guarkärnmjöl 4 veckor efter tillverkning jämfört med 4 dagar, men inga tydliga samband mellan högre syrahalt och nedbrytning av hydrokolloider syntes. Majonnäser med en blandning av 20% xantangummi och 80% guarkärnmjöl hade den konsistens som var mest lik referensen. I dessa försök med lågfettsmajonnäser ledde användandet av högre halt xantangummi till en oönskad ”slimig” textur och en lägre viskositet – en viktig aspekt om ett recept på lågfettsmajonnäs ska modifieras genom att öka halten xantangummi. Eftersom en kommersiell majonnäs ibland konsumeras flera månader efter tillverkning så är det troligtvis den tidsramen som krävs för att helt kunna mäta hur mycket den höga syrahalten i majonnäs kommer att påverka dess viskositet. Detta projekt har påvisat ett mönster där viskositeten i de analyserade majonnäserna börjar minska några veckor efter tillverkningen. Men för att få reda på exakt i vilken utsträckning och hur detta skulle påverka produkten i sin helhet, och i slutändan: om kombinationen med guarkärnmjöl och xantangummi är lämplig för majonnäser med lång hållbarhet krävs ytterligare studier.
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Dziadkowiec, Joanna. "Guar Gum/Montmorillonite Nanocomposites and Their Potential Application in Drug Delivery." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/33441.
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Clays are ubiquitous near the Earth’s surface. Medicinal properties of these nontoxic minerals have been intuitively recognized since ancient times. Up till now, clays have been used in pharmaceutical formulations as active agents and excipients. Currently, there is an urgent need to seek advanced, functional materials with low environmental impact. Answering to that trend, clay-biopolymer nanocomposites were synthesized in this thesis and applied in a drug delivery system. In the first part of the thesis, Portuguese clay from a bentonite deposit in Benavila (Portugal) was collected from six sampling sites and characterized. The highest content of clay fraction, approximately 30%, was found in two of the sampling sites. After purification, the smectite-rich samples were analyzed with respect to clay content, mineralogical and chemical composition, physicochemical and mechanical properties. SEM-EDS revealed that the smectite present in the ore is montmorillonite with varying Fe content. This was also indicated by the means of XRD, XRF and FTIR. The Benavila sample, which was richest in smectite, as well as the sodium Wyoming montmorillonite from the Source Clay Repository (SWy-2) were successfully used to synthesize clay-biopolymer nanocomposites. The chosen biopolymers were the plant-extracted polysaccharides – neutral guar gum and its cationic form. The obtained materials were thoroughly characterized by XRD, TGA and NMR, and the intercalated structure was reported. The prepared nanocomposites were loaded with an anti-inflammatory drug ibuprofen and tested in an in-vitro release system. The drug-loaded materials were characterized with XRD, TGA and NMR. A membrane diffusion method was chosen as a dissolution testing strategy and the drug was quantified by UV-Vis spectroscopy. The materials exhibited improved properties as a noticeable reduction of release rate was achieved.
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Garcia, Vidal Claudio Andres. "Molecular weight effects in guar gum adsorption and depression of talc." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44116.
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The effect of the molecular weight of guar gum on adsorption, talc depression, and stability of talc suspensions was studied. Four guar gum samples of different molecular weights in the range from 0.162 MDa to 1.4 MDa were used. It was also found that the intrinsic viscosities of the guar gum samples were independent of the type of background solution (NaCl, KCl, distilled water).
The adsorption density of the tested guar gum samples on talc was measured from the same background solutions at pH 9. The floatability of fine talc particles as well as their stability towards aggregation in the presence of guar gum were simultaneously determined so a direct relationship between talc depression and talc flocculation/dispersion by guar gum could be established. It was found that the effect of the molecular weight of guar gum on the adsorption density was negligible. No effect of the background electrolyte on guar gum adsorption was observed. All four guar gum samples were found to be equally strong depressants of talc flotation without any clear relationship with their molecular weights. It was determined that an adsorption density equal to about 20% of the complete surface coverage was sufficient to completely depress talc floatability. All guar gum samples also exhibited strong flocculating capabilities towards the talc particles at lower polymer dosages. As determined from turbidity data, higher molecular weight guar gum samples were more powerful flocculants than lower molecular samples. Most importantly, the strongest depression of talc flotation and the most pronounced flocculation of talc were found to occur at the same dosage. Higher doses of the polymers kept the talc particles completely depressed while simultaneously causing gradual steric redispersion of the mineral. The dispersing capabilities of the polymers were a function of the molecular weight, with the lower molecular weight samples bringing about stronger dispersion than higher molecular weight samples.
It was concluded that a high molecular weight guar gum would be the best depressant, since such a polymer would strongly depress the flotation of talc while minimizing talc dispersion and subsequent mechanical entrainment in the flotation concentrate.
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Hurley, Samantha Jane. "The physico-chemical mechanisms underlying the physiological effects of non-starch polysaccharides: studies in ileostomy patients." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310783.
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Queiroz, Viviane Miceli Silva. "Estudo experimental do escoamento e da concentração de mistura no processo de filtração tangencial de suspensões macromoleculares." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-16102009-085558/.
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O processo de microfiltração tangencial com membranas tubulares inorgânicas e tubos microporosos, respectivamente de origem importada e nacional, foi investigado tendo-se como objeto de separação as misturas macromoleculares preparadas com os agentes polissacarídeos gomas Xantana e Guar em suspensão aquosa. São evidenciados neste processo os efeitos de sinergia compreendidos nas misturas elaboradas puras e em diferentes proporções, na concentração final de 1000 ppm. A investigação experimental acompanha o comportamento reológico de cada mistura ao longo do processo e os resultados foram investigados a partir de propriedades físico-químicas relevantes como: concentração de carbono orgânico total (Total Organic Carbon - TOC) e análise de absorbância no espectômetro de infravermelho. Resultados de TOC indicaram que em apenas um meio filtrante tubular microporoso (C1T+), o desempenho do processo na retenção dos polissacarídeos foi acima de 90%, em relação ao processo com a membrana comercial importada cuja retenção de TOC foi da ordem de 80%. De acordo com as análises de absorbância, conclui-se que as membranas com tamanho do poro nominal de 0,2 \'mü\'m e 0,4 \'mü\'m tiveram uma retenção mais eficiente do que os tubos microporosos em estudo. A temperatura foi um parâmetro significativo, pois a retenção, na maioria dos casos, foi maior na temperatura de 25ºC, independente da pressão e da velocidade média. Na análise dos procedimentos envolvendo cada mistura, foi constatada a boa sinergia entre as gomas, sem modificação de estrutura (formação de gel) ou fenômenos de superfície que impedissem o processo de microfiltração. A vazão transmembrana das misturas ficou limitada entre os máximos valores para mistura pura de Xantana e mínimos para Guar. Todas as misturas apresentaram comportamento pseudoplástico, sem mudanças na reologia, reforçando a adequada sinergia quanto a este aspecto.The present dissertation reports cross-flow microfiltration with national and imported inorganic tubular membranes and microporous tubes. The object of separation is the macromolecular mixtures prepared with polysaccharide agents Xanthan and Guar gum in aqueous solution. The process shows the synergism effects in pure and different mixture proportions, with 1000 ppm final concentration. The experiments established the rheologic behaviour of each mixture along the process and significant physical and chemical properties, such as Total Organic Carbon concentration (TOC) and absorbency analysis in infrared spectrometer were analyzed. TOC retention shows that only one microporous tubular filtering medium (C1T+) had better performance (retention 90%) than the imported commercial membrane (retention about 80%). Absorbency analysis show a better retention efficiency of membranes with pore size of 0,2 \'mü\'m and 0,4 \'mü\'m than microporous tube. The temperature was a significant parameter, as the better retention was obtained at 25ºC, independently of pressure and mean velocity. There is good synergism between Xanthan and Guar gums without structure modifications or surface phenomena that would impede the microfiltration process. The transmembrane flux of proportional mixtures has been limited between maximum values of pure Xanthan and minimum values of pure Guar mixtures. All mixtures have pseudoplastic behaviour, without changes in rheology, intensifying the good synergism.
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Vallance, Charlene Elizabeth. "Intestinal cell proliferation and apoptosis : responses to dietary guar gum and cholesterol." Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287808.
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Koek, Mehmet Samil. "Heat processing of galactomannans." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312232.
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Martins, Tatiana dos Reis. "Microencapsulation of antitubercular drugs in a matrix of partially hydrolyzed guar gum, for application in tuberculosis treatment." Master's thesis, Instituto de Tecnologia Química e Biológica António Xavier. Universidade Nova de Lisboa, 2015. http://hdl.handle.net/10362/43588.
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Trabalho realizado na Universidade do AlgarveTuberculosis (TB), despite being a completely curable disease, has reemerged due to drug resistance and deadly synergism with HIV infection, which limit the success of its management. Lung tuberculosis is the main manifestation of TB. Thus, exploring the inhalable route for a local delivery of antitubercular drugs seems a promising therapeutic approach. Partially hydrolyzed guar gum (PHGG) is a strong candidate as matrix material for antitubercular drug carriers. This is mainly due to its affinity for macrophages, the hosts of mycobacteria, which is mediated by the binding of sugar units to macrophage surface receptors. In this work, PHGG-based microparticle formulations were produced by spray-drying, evaluated for cristallinity pattern (X-ray diffraction) and ability for drug association, and in vitro drug release profiles were determined. The cytotoxicity of microparticles was also evaluated (MTT and LDH release assays). Additionally, the therapeutic effect of drug-loaded microparticles was evaluated in vitro on macrophage-like cells infected with mycobacteria strains. The results showed that microparticles exhibited suitable properties for pulmonary delivery (aerodynamic diameter between 1 and 3 μm). A favorable cytotoxic profile was evidenced, as no overt toxicity was detected in representative respiratory cell lines (A549 and Calu-3 cells), although a mild toxic effect was observed in macrophage-like cells. The in vitro response of infected macrophages to drug-loaded PHGG microparticles was considered promising, as only 20% of mycobacteria remained viable upon a single treatment with microparticles. This thesis addresses macrophages as therapeutic target, unraveling the unique role of polysaccharides on pulmonary drug delivery in the ambit of tuberculosis therapy.
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Seddelmeyer, Laura M. "'On the edge of Asia': Australian Grand Strategy and the English-Speaking Alliance, 1967-1980." Ohio University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1399422337.
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Butler, Alan T. "The Descendants of Hurao: An Exploratory Study of Chamoru Rights Groups." Antioch University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1581359135361967.
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Moser, Poliana [UNESP]. "Comportamento reológico de gomas guar e xantana na presença de polióis." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/90748.
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Atualmente, os substitutos de açúcares têm ganhado destaque devido à crescente demanda do mercado mundial por alimentos que possuem baixo teor calórico e que atendam dietas específicas. Considerando que os componentes presentes nas formulações podem modificar as propriedades funcionais dos hidrocolóides, o objetivo deste trabalho foi estudar o comportamento reológico das gomas guar e xantana na presença de polióis. Soluções de goma guar (0,1, 0,5 e 1 %) e xantana (0,5 %) na presença de maltitol, sorbitol e xilitol nas concentrações de 10 à 40 % foram investigadas. O comportamento dessas misturas foi avaliado através de cisalhamento estacionário e oscilatório sob duas condições: em temperatura de 25 ºC e após o ciclo de congelamento e descongelamento. Em geral a adição dos polióis e o aumento de sua concentração elevaram a viscosidade aparente dos sistemas; somente para as soluções de guar 1 % com 40 % de poliol e xantana com 10 % de poliol a viscosidade foi reduzida. Os modelos Ostwald De Waelle e Herschel-Bulkley representaram satisfatoriamente o comportamento dos sistemas. Todas as soluções se mostraram pseudoplásticas e as soluções de guar 1 % com os polióis apresentaram tixotropia. As soluções de xantana com os polióis apresentaram tensão inicial para o escoamento. Os polióis também aumentaram os módulos dinâmicos (G’ e G’’) das soluções hidrocolóide/poliol, tornando os sistemas mais elásticos. Somente a solução de 10 % de sorbitol reduziu o valor de G’ da goma xantana, tornando o sistema menos consistente. Nas misturas de guar com 40 % de poliol, observou-se que o ângulo de fase apresentou valor ligeiramente inferior à 1 rad, com dependência da frequência, o que é característico de solução concentrada. A xantana pura possui características de solução...
Sugar substitutes have gained prominence because of the growing global market demand for foods that are low in calories and meet specific diets. Since the components present in the formulations may modify the functional properties of hydrocolloids, the aim of the present work was to study the rheological behavior of guar gum and xanthan in the presence of polyols. Solutions of guar gum (0,1, 0,5 and 1%) and xanthan (0,5%) in the presence of maltitol, sorbitol and xylitol at concentrations of 10 to 40% were investigated. The behavior of these mixtures was evaluated by steady and oscillatory shear under two conditions: at the temperature of 25 °C and after freezing and thawing cycle. In general, the addition of polyols and increasing their concentration increased the apparent viscosity of the systems; only for solutions of guar 1% with 40% polyol and xanthan with 10% polyol the viscosity was reduced. The Ostwald Waelle and Herschel-Bulkley models satisfactorily represented the behavior of systems. All solutions showed pseudoplastic behavior and guar solutions 1% with polyols showed thixotropy. Xanthan solutions with polyols showed yield stress to flow. Polyols also increased the dynamic modulus (G 'and G'') of hydrocolloid/polyol solutions, making systems more elastic. Only solution of sorbitol 10% reduced the value of G'of xanthan gum, making the system less consistent. For mixtures of guar with 40 % polyol, it was observed that the phase angle showed a value slightly lower than 1, with frequency dependence, which is characteristic of a concentrated solution. The pure xanthan has characterized concentrated solution in the presence of polyols and the value of δ was next to 0,5 rad, with little dependence on frequency, which characterizes weak gel. In solutions of guar and xanthan 0,5% polyols helped to preserve the... (Complete abstract click electronic access below)
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Moser, Poliana. "Comportamento reológico de gomas guar e xantana na presença de polióis /." São José do Rio Preto : [s.n.], 2012. http://hdl.handle.net/11449/90748.
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Orientador: Vânia Regina Nicoletti TelisBanca: Caciano P. Zapata Noreña
Banca: Renato Alexandre Ferreira Cabral
Resumo: Atualmente, os substitutos de açúcares têm ganhado destaque devido à crescente demanda do mercado mundial por alimentos que possuem baixo teor calórico e que atendam dietas específicas. Considerando que os componentes presentes nas formulações podem modificar as propriedades funcionais dos hidrocolóides, o objetivo deste trabalho foi estudar o comportamento reológico das gomas guar e xantana na presença de polióis. Soluções de goma guar (0,1, 0,5 e 1 %) e xantana (0,5 %) na presença de maltitol, sorbitol e xilitol nas concentrações de 10 à 40 % foram investigadas. O comportamento dessas misturas foi avaliado através de cisalhamento estacionário e oscilatório sob duas condições: em temperatura de 25 ºC e após o ciclo de congelamento e descongelamento. Em geral a adição dos polióis e o aumento de sua concentração elevaram a viscosidade aparente dos sistemas; somente para as soluções de guar 1 % com 40 % de poliol e xantana com 10 % de poliol a viscosidade foi reduzida. Os modelos Ostwald De Waelle e Herschel-Bulkley representaram satisfatoriamente o comportamento dos sistemas. Todas as soluções se mostraram pseudoplásticas e as soluções de guar 1 % com os polióis apresentaram tixotropia. As soluções de xantana com os polióis apresentaram tensão inicial para o escoamento. Os polióis também aumentaram os módulos dinâmicos (G' e G'') das soluções hidrocolóide/poliol, tornando os sistemas mais elásticos. Somente a solução de 10 % de sorbitol reduziu o valor de G' da goma xantana, tornando o sistema menos consistente. Nas misturas de guar com 40 % de poliol, observou-se que o ângulo de fase apresentou valor ligeiramente inferior à 1 rad, com dependência da frequência, o que é característico de solução concentrada. A xantana pura possui características de solução... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Sugar substitutes have gained prominence because of the growing global market demand for foods that are low in calories and meet specific diets. Since the components present in the formulations may modify the functional properties of hydrocolloids, the aim of the present work was to study the rheological behavior of guar gum and xanthan in the presence of polyols. Solutions of guar gum (0,1, 0,5 and 1%) and xanthan (0,5%) in the presence of maltitol, sorbitol and xylitol at concentrations of 10 to 40% were investigated. The behavior of these mixtures was evaluated by steady and oscillatory shear under two conditions: at the temperature of 25 °C and after freezing and thawing cycle. In general, the addition of polyols and increasing their concentration increased the apparent viscosity of the systems; only for solutions of guar 1% with 40% polyol and xanthan with 10% polyol the viscosity was reduced. The Ostwald Waelle and Herschel-Bulkley models satisfactorily represented the behavior of systems. All solutions showed pseudoplastic behavior and guar solutions 1% with polyols showed thixotropy. Xanthan solutions with polyols showed yield stress to flow. Polyols also increased the dynamic modulus (G 'and G'') of hydrocolloid/polyol solutions, making systems more elastic. Only solution of sorbitol 10% reduced the value of G'of xanthan gum, making the system less consistent. For mixtures of guar with 40 % polyol, it was observed that the phase angle showed a value slightly lower than 1, with frequency dependence, which is characteristic of a concentrated solution. The pure xanthan has characterized concentrated solution in the presence of polyols and the value of δ was next to 0,5 rad, with little dependence on frequency, which characterizes weak gel. In solutions of guar and xanthan 0,5% polyols helped to preserve the... (Complete abstract click electronic access below)
Mestre
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Chityala, Pavan Kumar. "Evaluation of Xanthan/Enzymatically Modified Guar Gum Mixtures in Oil-in-Water Emulsions." TopSCHOLAR®, 2015. http://digitalcommons.wku.edu/theses/1528.
Full textAbstract:
Oil-in-water emulsions have wide range of applications in food industry because of their structure-forming properties, and as delivery systems of polyunsaturated fatty acids into foods. The thermodynamic instability of oil and water, and high susceptibility of unsaturated fatty acids to oxidation lead to physical and oxidative stability in oil-in-water emulsions. These instability processes are generally controlled by incorporating proteins and polysaccharides into oil-in-water emulsions. The objective of this study was to evaluate xanthan/enzymatically modified guar (XG/EMG) polysaccharides on the physical and oxidative stability of 2 wt% whey protein stabilized oil-in-water emulsions containing 20% v/v menhaden fish oil. Enzymatic modified guar gum was obtained by hydrolyzing native guar gum using α-galactosidase enzyme. Emulsions were prepared for guar gum (GG), xanthan gum (XG), xanthan/guar (XG/GG), and xanthan/enzymemodified guar (XG/EMG) gum mixtures using 0, 0.05, 0.1, 0.15, 0.2, and 0.3% gum concentrations. Emulsions were then evaluated for creaming, viscosity, particle size, and microstructure to evaluate the physical stability, and peroxide value, TBARS value and GC-MS solid phase micro extraction (SPME) experiments were performed to evaluate the oxidative stability. Emulsions containing XG/EMG gum mixtures exhibited better creaming stability and higher viscosity of all the emulsion types. However, XG/EMG gum concentrations did not affect the droplet size of the emulsions. The microstructures revealed decreased flocculation in emulsions with XG/EMG mixtures. The primary and secondary lipid oxidation measurements indicated that emulsions containing XG/EMG gum mixtures were more effective in preventing the lipid oxidation of all the emulsion types. From the results, it is evident that XG/EMG gum mixtures can be used as emulsifiers in oil-in-water emulsions to increase both physical and oxidative stability.
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Resende, Fabrício de Souza. "Efeito do congelamento sobre a microestrutura da massa do pão." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-04112011-151945/.
Full textAbstract:
A qualidade global da massa de pão congelada por um longo período é um desafio para indústria de panificação. O uso de diferentes técnicas pode ajudar a explicar os danos sofridos à massa de pão durante o congelamento e armazenamento congelado. A presença de água na forma de cristais de gelo foi vista como a principal causa de defeitos à estrutura da massa. Gomas guar e xantana foram incorporadas às massas para contornar os danos causados pelo congelamento. Das análises térmicas conduzidas em calorímetro de varredura diferencial foi possível quantificar a quantidade de gelo presente na massa. A adição de (0,125 a 0,250) g/100g de goma guar e de (0,214 e 0,250) g/100g de goma xantana diminuíram os valores de entalpia na massa ao longo do armazenamento congelado. A fração de gelo foi menor e mais estável nas massas contendo (0,125 e 0,250) g/100g de goma guar ou xantana. O valor da atividade de água diminuiu nas massas contendo goma guar e com níveis mais altos de goma xantana, após o ciclo de congelamento e descongelamento e 170 dias de armazenamento. Alterações na estrutura das massas foram medidas e visualizadas pela análise de textura e por microscopia eletrônica de varredura (MEV). Adição de goma xantana e principalmente de goma guar às massas aumentaram a resistência à extensão após 170 dias de armazenamento congelado. A extensibilidade não foi influenciada pela adição de gomas e manteve estabilidade nos períodos de armazenamento estudados. A MEV ajudou a explicar os danos causados à rede de glúten pelos cristais de gelo ao longo do armazenamento congelado. A massa sem gomas apareceu com pequenos danos na rede de glúten com 21 dias de armazenamento e estes danos aumentaram progressivamente por até 170 dias, mostrando um glúten menos contínuo, mais rompido e separado dos grânulos de amido. As massas contendo gomas minimizaram, mas não evitaram os danos causados ao longo do armazenamento congelado.The global quality of the frozen bread dough for long periods of frozen storage is the challenge to bakery industry. The use of different techniques could help to explain the damages caused in the frozen dough during the freezing and along frozen storage time. The presence of water as ice crystals was the main cause of damage on the dough structure. In order to minimize the freezing damages, guar and xanthan gums were incorporated in the dough. From thermal analysis by DSC technique, the amount of ice present in the dough was determined. The addition of (0.125 to 0.250) g/100g guar gum and (0.214 and 0.250) g/100g xanthan gum presented lower values of fusion enthalpy. The addition of (0.125 and 0.250) g/100g of guar gum decreased or stabilized the frozen water content, suggesting minimal damage on the dough structure along frozen storage time. The water activity in the dough samples with guar gum and higher quantities of xanthan gum decreased after the freezing-thawed cycle and after a period of frozen storage of 170 days. The incorporation of xanthan gum and mainly the incorporation of guar gum increased the maximum resistance of the dough after 170 days. The extensibility was not affected by addition of gums along frozen storage time. The MEV technical helped to explain the damaged dough structure caused by ice crystals along frozen storage time. Dough samples without gums presented structure damage only after 21 days and increased after 170 days, resulting in less continuous gluten, more disrupted and separated from starch granules. The doughs with gums suffered less damage in the gluten matrix, but did not avoid the problems caused by frozen storage.
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Lynn, Miriam Elen. "Enterocyte maturity influences adhesion by lactobacillus." Thesis, University of Newcastle Upon Tyne, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.481471.
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