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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.
131

Simulação numérica de um sensor de tomografia capacitiva para análise de escoamento bifásico ar-água / Numerical simulation of a capacitance tomography sensor for the buphasic flow air-water analysis

Barros, Tiago Rodrigues de 04 November 2011 (has links)
Orientador: Luiz Felipe Mendes de Moura / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T04:18:01Z (GMT). No. of bitstreams: 1 Barros_TiagoRodriguesde_M.pdf: 8532346 bytes, checksum: 17a941d128ad1bcad0846f1722bc6270 (MD5) Previous issue date: 2011 / Resumo: Este trabalho tem como objetivo a simulação numérica de um sensor de tomografia capacitiva elétrica, em função da permissividade elétrica relativa das fases presentes dentro da tubulação, com a finalidade de determinar a melhor geometria do sensor para a geração de imagem de escoamentos numa mistura bifásica ar-água, levando em consideração fluidos com efeito da condutividade nula. A simulação numérica do sensor de tomografia capacitiva é de crucial importância para o desenvolvimento de um tomógrafo capacitivo usado em aplicações específicas, como é o caso do monitoramento de escoamentos bifásicos. A tomografia capacitiva elétrica é uma tecnologia recente que vem se desenvolvendo desde o início de 1980, quando começou a ser utilizada para análise de processos industriais, principalmente em escoamentos multifásicos. Ela é utilizada para gerar uma imagem do interior da tubulação de acordo com a permissividade relativa das fases ali presentes, sendo atualmente o tipo de tomografia de processos mais utilizada. Após a determinação de algumas premissas do projeto como, o diâmetro da tubulação que foi simulada na horizontal, o comprimento dos eletrodos que seriam montados do lado externo da tubulação, as simulações bidimensionais foram realizadas para se obter o melhor espaçamento entre os doze eletrodos do sensor e a distância ideal da blindagem externa. Com as simulações tridimensionais, foi investigada a necessidade de utilização dos eletrodos de guarda, assim como, foi realizada a simulação da geometria final do sensor numa mudança dos componentes de ar para água no interior da tubulação. Os resultados obtidos neste trabalho permitiram determinar a geometria mais adequada do sensor para a situação proposta, assim como, obter o valor das capacitâncias para diferentes condições de escoamento. Os resultados das simulações tridimensionais apontaram as principais limitações de uma análise bidimensional / Abstract: This study was aimed to realize numerical simulations of a capacitive electrical tomography sensor, depending on the relative permittivity of the phases inside the pipe, in order to determine the best geometry of the sensor to generate the image of the flow in the air-water two-phase flow, taking into account the effect of conductivity zero in the fluids. Numerical simulation of the ECT sensor is of crucial importance to develop a capacitive tomograph used in specific applications such as monitoring biphasic flow. Electrical capacitance tomography is a new technology that has been developed since early 1980, when it began to be used in industrial processes, mainly in multiphase flows. It is used to generate an image from inside the pipe according to the relative permittivity of the phases present there, and is currently the type of process tomography procedures most commonly used. After the determination of some assumptions of the project as the diameter of the pipe that was simulated in the horizontal, the length of the electrodes that must be assembled outside the pipe, the two-dimensional simulations were performed to obtain the best spacing between the twelve electrodes of the sensor and the ideal distance of the outer shield. With the three-dimensional simulations, we investigated the necessity of use guard electrodes, as well as, it was realized the simulation of the final geometry of the sensor components in a change of air to water inside the pipe. The results of this study allow us to determine the most suitable sensor geometry for the proposed situation, as well as obtaining the value of capacitance for different flow conditions. The results of three-dimensional simulations showed the main limitations of a two dimensional analysis / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica
132

An evaluation of the MMPI-2 using South African pre-trial forensic patients prediction of criminal responsibility and assessment of personality characteristics

Du Toit, Emile January 2004 (has links)
This study examines the utility of the MMPI-2 in predicting responsibility in pre-trial forensic patients, using a post hoc sample of 94 offenders from Sterkfontein Psychiatric Hospital in Gauteng. Firstly, the overall characteristics of the pre-trial forensic patients are discussed, following an analysis of demographic, clinical, criminal and MMPI-2 pre-trial data, as well as an overview of the Megargee typological classification of offenders. The sample is classified into Criminally Responsible (CR), Diminished Criminal Responsibility (DCR) and Not Criminally Responsible (NCR), and the CR and DCR groups are collapsed (CR/DCR) for many of the analyses when comparing them to the NCR group. Secondly, the variance of variables with responsibility is discussed, after examining one-way ANOVA’s of demographic, clinical, criminal and MMPI-2 variables, as well as an overview of high point pairs. Thirdly, discriminant analyses were conducted of demographic, clinical and MMPI-2 variables. When comparing the collapsed CR/DCR group to the NCR group, psychiatric diagnosis, presence of psychosis, the MMPI-2 Pa and Es scales, as well as race and substance abuse each had unique predictive power and created a substantial discriminative equation (F (6,70) = 45.732, p <0.0005) with a successful prediction rate of 96%. Using only MMPI-2 variables to predict responsibility showed significant unique contributions for the Pa, Es, MAC-R and Mf scales, with the BIZ scale not quite significant, and a fairly significant overall discriminant equation (F (5,73) = 6.474, p < 0.0005), with an overall successful prediction rate of 82%, with the MMPI-2 variables adding an additional 3% to the predictive power of the demographic and clinical variables. Similarly, when examining the more complex 3 group responsibility classification of CR, DCR and NCR, it was found that the demographic, clinical and MMPI-2 variables of psychiatric diagnosis, psychosis, race, substance abuse, and the Pa, Es and Ma scales all had significant contributions to a powerful discriminant analysis (F (14, 136) = 19.758, p < 0.0005) that was capable of correctly reclassifying almost 95% of the sample, and the MMPI-2 variables providing an increase in predictive power of 8%. Differences in responsible and not responsible pre-trial forensic patients are discussed, as well as the role of the MMPI-2 in assessing these differences, and the fact that it is highly likely that it adds more to the forensic assessment of responsibility than a 3% (CR/DCR versus NCR) or 8% (CR versus DCR versus NCR) increase in predictive power. Limitations of the study are discussed, together with recommendations for future research with the MMPI-2 for assessment of criminal responsibility. The suggestion is made that the MMPI-2 can become a valuable tool in South African forensic settings, not only in the assessment of responsibility and malingering, but also in the placement, management, follow-up and treatment of offenders, to maximize the limited resources in South Africa allocated for the rehabilitation of offenders, and minimize the risk of recidivism or rehospitalization.
133

Treatment Outcomes Related to EEG-Biofeedback for Chemical Dependency: Changes in MMPI-2™ (University of Minnesota) Personality Measures and Long Term Abstinence Rates

Callaway, Tonya Gayle 05 1900 (has links)
Peniston and Kulkosky (1989, 1990) demonstrated the effectiveness of alpha-theta EEG-Biofeedback (EEG-BFB) in treating inpatient alcoholics noting significant improvements in depression, psychopathology, serum β-endorphin levels, and abstinence rates. The present study is an extension of a previously unpublished replication of the Peniston EEG-BFB protocol with 20 chemically dependent outpatients (Bodenhamer-Davis, Callaway, & DeBeus, 2002). Fifteen subjects were "high risk for re-arrest" probationers. Data for the EEG-BFB group was collected from archival records. Subjects completed an average of 39 sessions (SD = 6.096), with 33 of those being EEG-BFB. Pre/post-treatment MMPI-2s™ (University of Minnesota) were collected and follow-up (4-11 years) data obtained (abstinence rates, re-arrests in some cases). Treatment effects were evaluated by comparing assessment data (pre/post) and documenting abstinence rates. Post-treatment MMPI-2 results were within normal limits, with several scales significantly reduced from baseline suggesting less psychopathology. Results were then compared to 20 subjects receiving standard addiction treatment (OT-CD group), but not EEG-BFB. OT-CD subjects completed a 2-week inpatient program followed by 18 outpatient sessions. Pre/post assessment and follow-up data was collected on the OT-CD group. The OT-CD group's post-assessment results showed three elevations (MMPI-2 scales 4/6/8), suggestive of characteriological problems. Post-MMPI-2 results of the two groups were compared via ANCOVAs. Findings indicated no significant differences between groups on targeted scales; however, there was a trend for the EEG-BFB group to have lower scores. Follow-up data was obtained on 13 EEG-BFB subjects. Results indicated 92% (n = 12) were sober, with 8% (n = 1) claiming significantly reduced alcohol intake. Probationer re-arrest and revocation rates were collected on the subset of probationers (n = 14 out of 15). The majority of the probationers (79%, n = 11) had not been re-arrested nor had their probation been revoked. Short-term follow-up information (35-131 days post-assessment), available at the time of writing, for the OT-CD group (N = 13) showed 85% (n = 11) were sober, with 15% (n = 2) relapsed. Limitations and implications of the study are discussed.
134

Heart Rate Variability at Rest and During Mental Stress in Patients With Coronary Artery Disease: Differences in Patients With High and Low Depression Scores

Sheffield, David, Krittayaphong, Rungroj, Cascio, Wayne E., Light, Kathleen C., Golden, Robert N., Finkel, Jerry B., Glekas, George, Koch, Gary G., Sheps, David S. 27 July 1998 (has links)
This study tested the hypothesis that coronary artery disease (CAD) patients with high depressed mood scores differ in sympatho-vagal balance during mental stress compared to patients with low depressed mood scores. Using electrocardiographic monitoring, heart variability data from spectral analysis and hemodynamic parameters were obtained prior to and during mental stress from 34 men and 7 women. A public speaking task was used as the mental stressor. Patients were grouped by a median split of their Minnesota Multiphasic Personality Inventory-Depression score. During mental stress, patients with higher depression scores had greater changes in peak heart rate (p < .05) and low frequency to high frequency power ratio (p < 0.05) than patients with lower scores suggesting a shift toward more sympathetic activity during mental stress. These findings may be related to the reported relation between depression and survival risk in patients with CAD.
135

The MMPI as a Predictor of Success Among Seminary Students

Cardwell, Sue Webb 01 August 1965 (has links)
Purpose of the study. Since the Minnesota Multiphasic Personality Inventory is the psychological test that is most widely used in seminaries in the United States, it was the purpose of this study (1) to establish norms for Christian Theological Seminary that could be compared with general norms and with the norms of two other studies, those of United Presbyterian and Southern California School of Theology seminarians, to help answer the question of how clergymen differ from non-clergymen and whether special norms need to be taken into consideration in the interpretation of MMPI protocols with seminary students; and (2) to see whether there are variables measured by the MMPI which can differentiate between effective an ineffective ministers and/or predict ministerial effectiveness as measured by (a) academic success as shown by grade point average for two semesters of seminary work, (b) ratings by the faculty and (c) ratings by fellow students, both using the Ministerial Effectiveness Rating Scale.
136

Validating the Rorschach Defense Scale by Examining Defensive Functioning in College Students

Esparza, Jana Scoville 05 1900 (has links)
This study attempted to provide validation for Lerner and Lerner's Rorschach Defense Scale by investigating the relationship between primitive defenses as measured by the Rorschach Defense Scale, level of object relations as measured by the Developmental Analysis of the Concept of the Object Scale, and characteristic defensive operations as assessed by the Minnesota Multiphasic Personality Inventory. One hundred and twenty undergraduates completed the Rorschach and MMPI, and the RDS and DACOS were applied to their Rorschach responses. The results show a significant positive correlation between use of primitive defenses and level of object relations development -and a significant negative correlation between the defense Projective Identification and MMPI scale 6 (Paranoia) elevation. Overall, these results did not support the validity of the RDS.
137

A 17-year Longitudinal Study of Spiritual Development and Psychological Correlates in a Sample of College Students

Bartz, Jeremy Daniel 21 September 2007 (has links) (PDF)
In 1984, 1987 and 2001 data were collected on a religiously devout group of college students in an effort to better understand the process of religious development and the relationship between religiosity and mental health. This study analyzes that data by examining the stability of two different religious development styles that were identified in 1984, the stability of religious motivations over the course of adulthood, and the relationship between devoutness and psychopathology. This study found that (a) the religious developmental styles did not remain consistent from 1984 to 2001, (b) the participants' religious motivations remained stable over the course of adulthood, and (c) these religiously devout individuals have consistently fallen within the normal range on measures of psychopathology and have demonstrated continual reduction in their scores on those measures. This Dissertation was later edited for journal publication. You can find that version here.
138

Structural Insight into Self-assembly of Coacervate-forming Polyesteramides

Liu, Xinhao 03 August 2022 (has links)
No description available.
139

Penicilli e Aspergilli associati al formaggio grana Approccio multifasico all'identificazione, fabbisogni ecologici e produzione di tossine / PENICILLIA AND ASPERGILLI ASSOCIATED TO GRANA CHEESE MULTIPHASIC IDENTIFICATION APPROACH, ECOLOGICAL NEEDS AND TOXINS PRODUCTION

DECONTARDI, SIMONE 31 May 2017 (has links)
Recentemente, l’ocratossina A (OTA) è stata segnalata in formaggio grattugiato confezionato: si ritiene sia stata prodotta dallo sviluppo di alcuni funghi durante il periodo di maturazione. Gli studi presentati in questa tesi hanno avuto lo scopo di migliorare la conoscenza dei funghi, Aspergilli e Penicilli, associati al formaggio di tipo grana. Si è dunque provveduto alla loro identificazione tramite approccio multifasico, eseguendo anche prove ecologiche per definire i fabbisogni delle specie presumibilmente dominanti. Obiettivo finale sarà quello di predire il rischio di contaminazione da micotossine alle condizioni ambientali di stagionatura del prodotto. Aspergillus puulaauensis e alcune specie del genere Penicillium (P.crustosum and P. solitum) sono state rilevate con maggior frequenza, mentre non sono state rilevate nei campioni di crosta le specie P. nordicum e P. verrucosum. In ogni caso, le condizioni ambientali dei locali di maturazione (15-22°C; 72-88% UR) sono risultate favorevoli allo sviluppo di queste ultime, dando adito a preoccupazione circa una possibile contaminazione da OTA; tuttavia, il ruolo di altre specie micotossigene, ad esempio P. crustosum, non va sottovalutato. Le azioni di contrasto verso questi funghi micotossigeni dovrebbero, innanzitutto, ridurre l’inoculo presente nell’aria: l’ozono sembra efficace in tal senso; inoltre, l’utilizzo della luce blu potrebbe ridurre notevolmente la crescita fungina sulla superficie dei formaggi e delle scaffalature. Le informazioni fornite in questa tesi saranno utili ai produttori e agli altri operatori della filiera di questo prodotto, aiutandoli ad attuare una miglior gestione del rischio e a garantire un prodotto sicuro e di elevata qualità ai consumatori. / Ochratoxin A (OTA) was detected a few years ago in Italian packed grated cheese, and supposed to be produced by fungal growth during cheese ripening. The works managed and presented in this thesis aimed to improve knowledge about mycotoxigenic Aspergilli and Penicillia associated to Italian grana cheese. A multiphasic approach was applied for their identification and ecological trials were organised to define fungal needs of the expected dominant species. The objective was to predict the risk of mycotoxin contamination during the ripening condition of grana cheese. Aspergillus puulaauensis and some Penicillium spp (P.crustosum and P. solitum) were the prevalent species associated to grana cheese, while neither P. nordicum, nor P. verrucosum were detected in cheese rind. However, the environmental conditions of the ripening rooms (15-22°C; 72-88% RH) are favourable to P. nordicum and P. verrucosum, reinforcing concern about possible OTA contamination, but other mycotoxigenic species such as P. crustosum must not be neglected. Actions against those mycotoxigenic fungi should mainly reduce total inoculum in the environmental air: ozone is reported to be effective in this sense; moreover, blue light may significantly reduce fungal growth on cheese and shelves surfaces. Information provided therein will be useful for producers and stakeholders to perform a better risk management and guarantee a safe, high-quality product to consumers.
140

Modélisation du disque intervertébral

Etienne, Marjorie 15 July 2013 (has links)
La dégénérescence discale est généralement considérée comme le résultat de l'insuffisance chronique de la nutrition de ses cellules due à un déficit du renouvellement de la matrice extra-cellulaire. Des chargements mécanique excessifs et répétés sont parmi les principales causes créant des lésions dans les disques et à terme précipitent la dégénérescence discale. En modélisant le fonctionnement multi-physique du disque par un modèle quadriphasique couplé à un modèle métabolique des cellules, l'objectif de ce travail est d'aider à une meilleure compréhension du fonctionnement discal. Puis par une approche numérique, le lien entre sollicitation mécanique, nutrition et dégénérescence est étudié. Dans un premier temps, le disque a été représenté en 2D. L'effet d'un cycle nycthéméral simplifié sur les paramètres osmotico-mécaniques et nutritionnels du disque lombaire d'un sujet de corpulence normale et d'un sujet en surpoids ou portant des charges a alors été analysé. Dans un second temps, à travers une approche 3D, l'influence sur la fonction discale de mouvements rapides associés à la vie quotidienne, telles qu'une flexion, une flexion latérale et une rotation axiale, a été quantifiée. En outre, pour ces deux approches, une étude comparative a été réalisée afin d'étudier l'influence réelle de la convection par rapport à la diffusion dans le transport des nutriments. Ainsi, ce travail constitue une contribution à une meilleure compréhension de l'évolution spatiale et temporelle des nutriments et des paramètres osmotico- mécaniques du disque intervertébral, lorsque ce dernier est soumis à différents types de chargements. / Disc degeneration is generally regarded as the result of chronic insufficiency of cell nutrition due to a lack of renewal of the extracellular matrix. Excessive and repeated mechanical loads are among the leading causes of injury in the disc and eventually precipitate disc degeneration. By modeling the multi-physics functioning of the disc by a quadriphasic model coupled with a metabolic model, the aim of this work is to contribute to a better understanding of the disc functions. With a numerical approach, the relationship between mechanical stress, nutrition and degeneration is studied. The disc was first represented in 2D. The effect of a simplified circadian cycle on the osmotico-mechanical and nutritional parameters of lumbar disc of a normal weight and overweight (or carrying loads) subjects was then analyzed. After that, through a 3D approach, the influence of the disc function towards rapid movements such as bending, lateral bending and axial rotation was quantified. In addition to these two approaches, a comparative study was conducted to investigate the real influence of convection compared to diffusion in the transport of nutrients. This work contributed to a better understanding of the spatial and temporal evolution of nutrients and osmotico-mechanical parameters of the intervertebral disc when it is subjected to different loadings.

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