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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.
41

Occurrence and Evaluation of White Spot Lesions in Orthodontic Patients: A Pilot Study

Franks, David January 2014 (has links)
Orthodontic treatment may cause an increase in the rate of enamel decalcification on tooth surfaces, producing White Spot Lesions (WSL). Orthodontic patients are at a higher risk for decalcification because orthodontic appliances retain food debris which leads to increased plaque formation. Dental plaque, an oral biofilm formed by factors including genetics, diet, hygiene, and environment, contains acid producing bacterial strains with a predominance of Mutans Streptococcus (MS). MS and others metabolize oral carbohydrates during ingestion, the byproducts of which acidify the biofilm to begin a process of enamel decalcification and formation of WSL. This study tests if patients in orthodontic treatment at Temple University can be used as subjects for further longitudinal study of WSL risk factors. Twenty patients between the ages of ten to eighteen after three months or greater of treatment were enrolled to determine if duration of treatment, hygiene, sense of coherence, obesity, diet frequencies, age and gender correlated with development of WSL. Of these, age is positively correlated with the number of untreated decayed surfaces. WSL and plaque levels may negatively correlate with increased brushing frequency and duration, while flossing frequency demonstrated a statistically significant negative correlation. This population may be suitable for further study because of its high incidence of WSL (75%), however difficulty in enrollment and patient attrition necessitates that future studies be modified. / Oral Biology
42

An ex post facto evaluation of the Philadelphia GunStat model

Sorg, Evan Thomas January 2015 (has links)
In January of 2012, Philadelphia Mayor Michael Nutter outlined the crime fighting measures that his administration would pursue during his second term as mayor. Included was a plan to introduce a multi-agency crime reduction program, which Philadelphia Police Commissioner Charles Ramsey and District Attorney Seth Williams would co-chair, called GunStat. GunStat was described as a collaborative effort to reduce gun violence through (1) identifying locations with a high incidence of violent crime, (2) pinpointing violent offenders responsible for these crimes, (3) focusing on arresting and prosecuting these offenders for crimes committed at these places, and (4) enhanced monitoring of offenders on probation and parole who are living and/or offending within these locations. In effect, GunStat was designed to target the right people (prolific, violent known offenders) at the right places (hot spots of violent crime). This dissertation is an in-depth, ex post facto evaluation of Philadelphia’s GunStat model as implemented over two phases and two years. It involved both a quasi-experimental research design which employed propensity score matching methods to generate comparisons, and a process-evaluation where several themes, including program implementation, were explored. The results here suggest that GunStat did not reduce crime relative to comparison locations. However, the qualitative data highlighted the importance of informal inter-agency networks that were developed during the course of the intervention, and suggested that GunStat put future collaborations on a solid footing. The implications for criminal justice policy, theory and evaluation design are discussed. / Criminal Justice
43

Correlation of early leafspot disease in peanut with a weather- dependent infection index

Jewell, Elspeth Lea January 1987 (has links)
Development of early leafspot, caused by Cercospora arachidicola Hori, was monitored on' Florigiant' peanut (Arachis hypogaea L.) at two field sites in Suffolk, Virginia. In one study, plants in 27-cm-diameter plots were inoculated with 20,000 conidia and inoculation dates were replicated in five randomized complete blocks. At location one in 1985 and 1986, lesions/leaf at two weeks after inoculation correlated significantly (P ≤ 0.05) with infection indices (IND) developed by the Virginia leafs pot advisory and hours of relative humidity (RH) ≥ 95%. At location two, correlations between lesions/leaf and IND as well as hours of RH ≥ 95% were significant in 1986, but not in 1985. Certain site specific factors were believed to have altered plant susceptibility to leafspot at this site in 1985. In another study, pots with greenhouse-grown peanut were placed between unsprayed rows of field plants, heavily colonized by C. arachidicola. Plants were removed after 3, 5, and 7 days of field exposure for six consecutive weeks in 1986 and returned to the greenhouse. Lesions/leaf at two weeks after initial exposure were correlated with IND values computed by five versions of the leaf spot advisory. Significant correlations were found between lesions/leaf on plants with field exposures of 5 and 7 days and cumulative IND values and hours of RH ≥ 90% and 95%. The low incidence of lesions resulting with field exposures of only 3 days coupled with a lack of significant correlations between disease and cumulative IND values for 3 days after inoculation in both studies suggests that infection processes require several days, and that fungicides may be applied to achieve disease control during this time. / M.S.
44

O ethos discursivo do PT e do DEM em spots da campanha eleitoral à Prefeitura de São Paulo em 2008

Ribeiro, Alice Pasqualina Vitorino 19 July 2011 (has links)
Made available in DSpace on 2016-04-28T18:22:20Z (GMT). No. of bitstreams: 1 Alice Pasqualina Vitorino Ribeiro.pdf: 619376 bytes, checksum: 0599de92976490379ead687927e4c28b (MD5) Previous issue date: 2011-07-19 / Based on the problematic Brazilian political relations, I analyze the political discourse during electoral campaign. The analyzed corpus constituted of spots exhibited on the TV during dispute of the São Paulo s town hall, in 2008, by Marta Suplicy (PT) and Gilberto Kassab (DEM) candidates. From procedure lecture based on French Discourse Analysis, as proposed by Maingueneau, and based in the relation between different discourse plans, with focuses on the ethos and cenography notions, the work aims to perceive the sense effects built in political discourses. The corpus constitution and analysis, use evidential paradigm (GINZBURG, 1991), whose proposal is like discourse analyst activity, which characterize fundamentally evidential description which become possible understand different discourse plans. Analyses realized perceive different cenographies. The ethos of candidates might be composed of several traces. DEM enterprise ethos meets traces as competence, informally and humor. PT ethos is more maternal , conservative and aggressive. The research possibility concluding which spots of electoral campaign tend an infantilization process of political discourse, campaign trivialization, with traces of humor, tendency that seeming confirm in the Republic presidential electoral campaign in 2010 / No âmbito de reflexões sobre a problemática das relações políticas no Brasil contemporâneo, analiso o discurso político em época de campanha eleitoral. O corpus analisado é constituído de spots veiculados na televisão por ocasião da disputa à Prefeitura de São Paulo, em 2008, pelas candidaturas de Marta Suplicy e Gilberto Kassab, dos partidos PT e DEM, respectivamente. A partir de procedimentos de leitura ancorados nos princípios da Análise do Discurso francesa (AD), sob a perspectiva de Dominique Maingueneau (1997, 2006, 2007, 2008, 2010), e com base na relação entre os diferentes planos do discurso, com ênfase nas noções de cenografia e ethos, o trabalho procura depreender os efeitos de sentido criados em discursos políticos. Para a constituição e análise do corpus, utilizo o método indiciário (GINZBURG, 1991), cuja proposta se assemelha à atividade do analista do discurso que se caracteriza fundamentalmente pela descrição de indícios que tornam possível a interpretação dos diversos planos do discurso. As análises realizadas permitem depreender diversas cenografias. O ethos de uma candidatura parece se compor de vários traços. O ethos empreendedor do DEM reúne traços como a competência, descontração e humor. O do PT apresenta um tom mais maternal , conservador e agressivo. A pesquisa permite concluir que os spots das campanhas eleitorais tendem a um processo de infantilização do discurso político, de banalização das campanhas, com traços de espetacularização pelo humor, tendência que talvez se possa confirmar na campanha eleitoral de 2010 à presidência da República
45

The crime in “turning a car from a tool for getting somewhere into a tool for unmistakably being somewhere.” : En hot spots-analys av hög och störande musik från fordon

Wilund, Lina January 2020 (has links)
I den här kvantitativa GIS studien har spatiala och temporala koncentrationer/hot spots gällande hög och störande musik från fordon studerats i syfte att undersöka dessa platsers kriminogenitet och gemensamma miljömässiga karaktär samt den sociala kontext som kan vara kopplat till problemet. Studiens resultat visade på tre stabila hot spots men att dessa inte gällde för övrig brottslighet. Platserna kunde därför inte bedömas som kriminogena utom gällande den störande musiken från fordon. Det gemensamma för dessa platser visades vara närheten till genomfartsleder, parkeringsplatser och bensinpumpar. Studien kommer fram till att syftet med att spela musiken inte är att störa andra, utan om att ha kul, hänga med likasinnade, skapa identitet och visa sin kultur genom att synas och höras. Och att valet av plats inte beror på något annat än att de är geografiskt och bekvämt belägna och har de egenskaperna och attribut som passar dessa sammankomster. / This quantitative paper contains a spatial and temporal GIS-analysis regarding hot spots of loud and disturbing music from vehicles, in order to investigate the criminogenic and environmental character of these occurrences, as well as the social context that may be linked to the problem. The results of the study showed three stable hot spots but also that these hot spots did not apply to other crime, the locations could therefore not be judged as criminogenic except for the disturbing music from vehicles. What these places had in common was the proximity to thoroughfares, parking lots and petrol pumps. The study concludes that the purpose of playing music loud is not to disturb others, rather having fun, hanging out with like-minded people, and creating identity and acting out culture by being seen and heard. And that the reason these events happen in these places is not due to anything other than that they are geographically and conveniently located, and they also have the necessary characteristics to suit such gatherings.
46

Covid-19 och alkoholförbudet : Hur har det påverkat polisen och våldet i Malmö? / Covid-19 and the alcohol restriction : How has it affected the police and the violence i Malmö?

Persson, Jenny, Jangmalm, Lovisa January 2021 (has links)
Covid-19 har påverkat hela världen och fokus har legat på att minska smittspridningen. I Sverige har detta föranlett att ett alkoholförbud infördes i november 2020, vilket begränsat serveringsställens öppettider. Hur pandemin och dess förbud har påverkat brottsligheten är ett relativt outforskat område och det finns enligt författarnas kännedom ingen studie om alkoholförbudets effekter. Denna studie ämnar undersöka vilken påverkan som förbudet haft på polisens arbete på mikroplatser samt nivåerna av våld i offentlig miljö och antal omhändertaganden enligt LOB i Malmö stad. Studien har såväl en kvalitativ som kvantitativ ansats. Empirin har samlats in genom semistrukturerade intervjuer med fem poliser och anmälningsstatistik mellan 2017–2021 över våld i offentlig miljö och omhändertaganden enligt LOB. Resultaten visar att de intervjuade poliserna upplever att alkoholförbudet minskat folkmängden på mikroplatserna i nöjesmiljöer och att det föranlett såväl en förskjutning av arbetstider som resursförflyttning. De är även av uppfattningen att berusningsgraden och det offentliga våldet på mikroplatserna har minskat efter alkoholförbudet. Däremot visar statistiken att nivåerna över offentligt våld är oförändrade, vilket kan innebära att platsen för brottet förändrats. Enligt såväl de intervjuade poliserna som statistiken över antal genomförda LOB:ar har det efter alkoholförbudet skett en avsevärd minskning, jämfört med tidigare år. Alkoholförbudet tycks därmed ha inneburit att rutinaktiviteter förändrats och att våldet begås på andra platser än på de mikroplatser där polisen arbetar. För att kunna dra säkra slutsatser om pandemin och dess restriktioners påverkan på brottsligheten behövs studier som kan undersöka dess långsiktiga effekter. / Covid-19 has affected the entire world and the main focus has been on reducing the spread of the virus. An alcohol restriction policy was implemented in Sweden as of November 2020, which has limited the opening hours of serving establishments. How the pandemic and its restrictions has affected crime has not been widely examined and there are to the authors knowledge no studies about the effects of the alcohol restriction. This study aims to look into what impact the restriction has had on the work of the police at hot spots and the levels of public violence and the number of people taken into custody in accordance with LOB in the city of Malmö. The study has a qualitative and quantitative approach. The data was collected through semi-structured interviews with five police officers and statistics of reported levels of public violence between 2017-2021 and the number of people taken into custody in accordance with LOB. The results show that the interviewees experience that the alcohol restriction has reduced the amount of people at hot spots located in entertainment environments and caused their working hours to change and resources to relocate. They are also of the perception that the intoxication level and public violence at the hot spots has decreased after the alcohol restriction. On the contrary, no changes of the levels of public violence has been identified in the analyzed statistics, which can indicate that the violence has relocated. According to both the interviewees and statistics, the number of people taken into custody in accordance with LOB has significantly decreased after the alcohol restriction, compared to previous years. The alcohol restriction may have changed people’s routine activities and that the violence is committed at other locations than at the hot spots. Further studies are needed to be able to make certain conclusions about the long-term effects of the pandemic and its restrictions on crime.
47

COPS ON DOTS DOING WHAT? THE DIFFERENTIAL EFFECTS OF POLICE ENFORCEMENT ACTIONS IN HOT SPOTS

Haberman, Cory P. January 2015 (has links)
Although hot spots policing has become one of the most promising policing strategies, the empirical evidence on the effectiveness of hot spots policing does not suggest what police should be doing in crime hot spots. To date, police enforcement actions – pedestrian investigations, traffic enforcement, and arrests – still dominate American policing. Yet empirical studies of these actions have not: focused on micro-geographic areas, employed multiple measures of police enforcement actions, or empirically compared the effectiveness of different enforcement actions. Given these gaps in the literature, a mixed-methods study sought to answer four research questions. (1) Do four police enforcement actions focused on offenders or potential offenders reduce violent crime in hot spots? The four police enforcement actions examined were pedestrian investigations, traffic enforcement events, quality of life arrests, and violent crime arrests. (2) Are any one of these four police enforcement actions more effective than the others? (3) When police commanders allocate resources to crime hot spots, what do police commanders think they are doing? (4) What are police commanders’ rationales for what they do in crime hot spots? The first two questions were answered using official data from the Philadelphia Police Department. A purposive sample of 169 high crime street blocks and intersections was drawn and longitudinal data analyses examined the effects of police enforcement actions on monthly violent crime counts from 2009 to 2013 (n = 10,140). Wald Tests were used to test for the differential effectiveness of the four enforcement actions. Qualitative methods answered the remaining two research questions. Field observations of crime strategy meetings (May, 2014 to August, 2014) and interviews with police commanders (November, 2014 to February, 2015) were conducted. The quantitative results found total enforcement and pedestrian stop levels in the previous or same month linked to higher expected monthly violent crime counts. The positive effect of pedestrian stops was significantly larger than the effects of traffic enforcement or quality of life arrests. Despite the positive relationship between police enforcement and violent crime, the qualitative results provided insight into what police commanders thought they were doing in crime hot spots. Three themes emerged from the qualitative data: (1) “locking down” crime hot spots, (2) disrupting high risk offenders, and (3) educating potential victims. Police commanders rationalized these beliefs with four explanations of their effectiveness: (1) making offenders “think twice”, (2) denying potential offenders and victims certain places in order to reduce crime opportunities, (3) getting high risk offenders “off the street”, and (4) target hardening. Drawing on theorizing for how police enforcement actions might actually link to higher levels of crime (Grabosky, 1996) and methodological concerns raised by Taylor (2015), five possible explanations for the observed positive relationships among police enforcement actions and violent crime are provided: (1) an anticipatory effect, (2) over-deterrence, (3) escalation, (4) unintended enticement and self-fulfilling prophecies, and (5) temporal scaling. The anticipatory effect explanation centers on the police correctly anticipating outbreaks of violent crime but violent crime still not being reduced due to (1) dosage, (2) the overuse of enforcement, (3) police legitimacy, (4) temporal displacement or two components the study’s design (5) imprecise measurement and (6) lack of a proper counterfactual. Additionally, police enforcement actions may inadvertently reduce guardianship though over-deterrence, escalate competition among rival offenders, or inform potential offenders of crimes they could or “should” be committing. Finally, the study’s temporal scale (i.e., months) may not be fine enough to capture the actual cycling of how increased enforcement actions produce lower violent crime levels. The qualitative data are drawn upon to possibly support these explanations. Additionally, the pros and cons of police commanders’ perspectives on the use and effectiveness of enforcement actions are discussed in context of the criminological theory and crime control literatures. Finally, the results are discussed in terms of their implications for crime control theory and policy. / Criminal Justice
48

Studium vlivu parametrů na pohyb elektrodových skvrn v modelu zhášecí komory elektrického přístroje / Study of arc root movement in a model of the LV quenching system

Fendrych, Martin January 2016 (has links)
Thesis focuses on the basic characteristics of plasma, problems about origin of electrode spots and electrodynamics force acts on the electric arc. In the practical part was realized and produced model of a LV quenching system. Using optical diagnostics was received necessary data to analyze the movement of the electrode spots. The movements of the electrode spots were analyzed in terms of value RMS current passing through the electric arc, value of absolute pressure model in the LV quenching system and distance from each electrode.
49

Investigação por meio de efeito SERS e SERRS dos sistemas híbridos formados pela interação da 3,6-bi-2-piridil-1,2,4,5-tetrazina e complexos de rutênio com ouro macroscópico e nanoparticulado / Investigation of SERS and SERRS effect of the Hybrid Systems made by the interaction of 3,6-bi-2-pyridyl-1,2,4,5-tetrazine and its ruthenium complexes with macroscopic and nanoparticle gold

Melo, Vitor Hugo Soares de 10 May 2010 (has links)
A síntese e caracterização de sistemas hetero-híbridos gerados a partir da 3,6-bi-2-piridil-1,2,4,5-tetrazina (bptz) e interações com ouro nanoparticulado são abordados nesta tese. O bptz foi estudado por meio de métodos espectroscópicos e teóricos, focalizando principalmente o efeito SERS associado à adsorção em nanopartículas de ouro. O mecanismo de transferência de carga para metais macroscópicos foi transposto para a condição nanoparticulada, envolvendo ligações químicas entre bptz e as nanopartículas. Os complexos estudados possuem fórmula geral [LmRu(µ-bptz)RuLm]Xn, com “L” indicando os ligantes periféricos 5-cloro-1,10-fenantrolina (Clphen) ou 4’-(fenil)-2,2&#8217:6&#8217,2&#8221-terpirdina (ptpy) e “X” os contra-íons. Foram investigadas suas espectroeletroquímicas eletrônica e SERS, e as mudanças de perfil vibracional foram modeladas, incorporando o mecanismo de transferências de carga entre complexo e o ouro, além dos mecanismos ressonantes e eletromagnéticos / The synthesis and investigation of heterohybrid systems encompassing 3,6-bi-2-pyridyl-1,2,4,5-tetrazine (bptz) and its ruthenium complexes associated with gold nanoparticles are dealt with in this thesis. Bptz was characterized by spectroscopic and theoretical techniques, focusing on its SERS spectra after the adsorption onto nanoparticles. The charge transfer mechanism in the SERS spectra of macroscopic metals was transposed to the nanoparticle condition, assuming the formation of chemical bonds between bptz and the nanoparticles. Complexes of general formula [LmRu(µ--bptz)RuLm]Xn, “L” the peripheric ligants 5-chlorine-1,10-phenantroline or 4’-(phenyl)-2,2&#8217:6&#8217,2&#8221-terpyrdine (ptpy), and “X” counter-ions were also investigated, with special emphasis on their electronic and SERS spectroelectrochemistry. The changes in the vibrational profiles were successfully explained by the occurrence of charge transfer between the adsorbed complex and gold, in addition to the electromagnetic and resonance mechanisms.
50

Análise do comportamento termoelástico de um freio a tambor, utilizando o método dos elementos finitos / Analysis of the thermoelastic behavior of a drum brake, using the finite element method

Ribeiro, Gustavo dos Santos 15 July 2015 (has links)
O objetivo desse trabalho é apresentar o desenvolvimento de modelos numéricos baseados no método dos elementos finitos, para investigar o comportamento termoelástico, de um freio a tambor utilizado em veículos pesados. O acoplamento de fenômenos físicos e mecânicos durante o processo de frenagem é uma etapa fundamental para o projeto com foco em confiabilidade. A identificação de falhas potenciais decorrentes dos diferentes processos de frenagens, ainda na fase do projeto preliminar, permite o desenvolvimento de projetos mais robustos, incluindo reduções de tempo e nos custos de ensaios experimentais. Este trabalho apresenta o desenvolvimento e implementação de um modelo computacional baseado no comportamento termoelástico dos principais elementos mecânicos de um freio a tambor envolvidos no processo de frenagem. Foram consideradas três condições principais de análise: estática de corpos rígidos, estática de corpos flexíveis e dinâmica em regime permanente com corpos flexíveis. O objetivo é investigar e estimar valores de pressão de contato, cargas resultantes nos apoios, bem como obter o gradiente de temperatura e tensão devido à carga térmica em regiões de interesse. Essa análise pode melhorar o entendimento dos fenômenos envolvidos nos diferentes processos de frenagens, auxiliando as tomadas de decisões técnicas, principalmente na antecipação de falhas prematuras relacionadas com fadiga térmica e desgaste adesivo. / This work presents the development of a numerical model based on thermoelastic behavior of a drum brake applied to heavy vehicles. The coupling of physics and mechanical phenomena during the braking process represents an important phase in the design vehicle systems. The identification of potential failures during the braking processes, considering the preliminary design phase gives robustness to the design. This characteristic allows reducing the time and cost of experimental set-up. This work presents the development and preliminary results of a numerical model based on thermal-elastic behavior of an automotive drum brake. It was considered three main conditions for the analysis: rigid bodies statics, flexible bodies statics and flexible bodies steady state dynamic analysis. The main objective of this study is investigate and estimate the relationship between the design parameters, as strain, stress as well thermal loads and temperature gradient, in conditions of static and quasi-static steady state regime. The estimative of these parameters to support the technical decisions related to reliability design, mainly to anticipate failures arising to thermal fatigue and adhesive wear.

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