Using overlay test to evaluate fracture properties of field-aged asphalt concrete

Field material testing provides firsthand information on pavement conditions which are most helpful in evaluating performance and identifying preventive maintenance or overlay strategies. High variability of field asphalt concrete due to construction raises the demand for accuracy of the test. Accordingly, the objective of this study is to propose a reliable and repeatable methodology to evaluate the fracture properties of field-aged asphalt concrete using the overlay test (OT). The OT is selected because of its efficiency and feasibility for asphalt field cores with diverse dimensions. The fracture properties refer to the Paris’ law parameters based on the pseudo J-integral (A and n) because of the sound physical significance of the pseudo J-integral with respect to characterizing the cracking process. In order to determine A and n, a two-step OT protocol is designed to characterize the undamaged and damaged behaviors of asphalt field cores. To ensure the accuracy of determined undamaged and fracture properties, a new analysis method is then developed for data processing, which combines the finite element simulations and mechanical analysis of viscoelastic force equilibrium and evolution of pseudo displacement work in the OT specimen. Finally, theoretical equations are derived to calculate A and n directly from the OT test data. The accuracy of the determined fracture properties is verified. The proposed methodology is applied to a total of 27 asphalt field cores obtained from a field project in Texas, including the control Hot Mix Asphalt (HMA) and two types of warm mix asphalt (WMA). The results demonstrate a high linear correlation between n and −log A for all the tested field cores. Investigations of the effect of field aging on the fracture properties confirm that n is a good indicator to quantify the cracking resistance of asphalt concrete. It is also indicated that summer climatic condition clearly accelerates the rate of aging. The impact of the WMA technologies on fracture properties of asphalt concrete is visualized by comparing the n-values. It shows that the Evotherm WMA technology slightly improves the cracking resistance, while the foaming WMA technology provides the comparable fracture properties with the HMA. After 15 months aging in the field, the cracking resistance does not exhibit significant difference between HMA and WMAs, which is confirmed by the observations of field distresses.

A heuristic algorithm to generate test program sequences for moving probe electronic test equipment

The electronics industry, is experiencing two trends one of which is the drive towards miniaturization of electronic products. The in-circuit testing predominantly used for continuity testing of printed circuit boards (PCB) can no longer meet the demands of smaller size circuits. This has lead to the development of moving probe testing equipment. Moving Probe Test opens up the opportunity to test PCBs where the test points are on a small pitch (distance between points). However, since the test uses probes that move sequentially to perform the test, the total test time is much greater than traditional in-circuit test. While significant effort has concentrated on the equipment design and development, little work has examined algorithms for efficient test sequencing. The test sequence has the greatest impact on total test time, which will determine the production cycle time of the product. Minimizing total test time is a NP-hard problem similar to the traveling salesman problem, except with two traveling salesmen that must coordinate their movements. The main goal of this thesis was to develop a heuristic algorithm to minimize the Flying Probe test time and evaluate the algorithm against a "Nearest Neighbor" algorithm. The algorithm was implemented with Visual Basic and MS Access database. The algorithm was evaluated with actual PCB test data taken from Industry. A statistical analysis with 95% C.C. was performed to test the hypothesis that the proposed algorithm finds a sequence which has a total test time less than the total test time found by the "Nearest Neighbor" approach. Findings demonstrated that the proposed heuristic algorithm reduces the total test time of the test and, therefore, production cycle time can be reduced through proper sequencing.

New Method Based on the UNIFAC–VISCO Model for the Estimation of Ionic Liquids Viscosity Using the Experimental Data Recommended by Mathematical Gnostics

The viscosity of ionic liquids (ILs) has been modeled as a function of temperature and at atmospheric pressure using a new method based on the UNIFAC–VISCO method. This model extends the calculations previously reported by our group (see Zhao et al. J. Chem. Eng. Data 2016, 61, 2160–2169) which used 154 experimental viscosity data points of 25 ionic liquids for regression of a set of binary interaction parameters and ion Vogel–Fulcher–Tammann (VFT) parameters. Discrepancies in the experimental data of the same IL affect the quality of the correlation and thus the development of the predictive method. In this work, mathematical gnostics was used to analyze the experimental data from different sources and recommend one set of reliable data for each IL. These recommended data (totally 819 data points) for 70 ILs were correlated using this model to obtain an extended set of binary interaction parameters and ion VFT parameters, with a regression accuracy of 1.4%. In addition, 966 experimental viscosity data points for 11 binary mixtures of ILs were collected from literature to establish this model. All the binary data consist of 128 training data points used for the optimization of binary interaction parameters and 838 test data points used for the comparison of the pure evaluated values. The relative average absolute deviation (RAAD) for training and test is 2.9% and 3.9%, respectively.

Design and implementation of BIRDY satellite data and Radiation Payload simulators

Numerical modelling and simulations are needed to develop and test specific analysis methods by providing test data before BIRDY would be launched. This document describes the "satellite data simulator" which is a multi-sensor, multi-spectral satellite simulator produced especially for the BIRDY mission which could be used as well to analyse data from other satellite missions providing energetic particles data in the Solar system.

Development of an Economic Dust Palliative for Limestone Surfaced Secondary Roads, HR-297, Progress Report, 1988

Research activities during this period concentrated on continuation of field and laboratory testing for the Dallas County test road. Stationary ditch collection of dust was eliminated because of inconsistent data, and because of vandalism to collectors. Braking tests were developed and initiated to evaluate the influence of treatments on braking and safety characteristics of the test sections. Dust testing was initiated for out of the wheelpath conditions as well as in the wheelpath. Contrary to the results obtained during the summer and fall of 1987, the 1.5 percent bentonite treatment appears to be outperforming the other bentonite treated sections after over a year of service. Overall dust reduction appears to average between 25 to 35 percent. Dallas County applied 300 tons per mile of class A roadstone maintenance surfacing to the test road in August 1988. Test data indicates that the bentonite is capable of interacting and functioning to reduce dust generation of the new surfacing material. Again, the 1.5 percent bentonite treatment appeared the most effective. The fine particulate bonding and aggregation mechanism of the bentonite appears recoverable from the environmental effects of winter, and from alternating wet and dry road surface conditions. The magnesium chloride treatment appears capable of long-term (over one year) dust reduction and exhibited an overall average reduction in the range of 15 to 30 percent. The magnesium chloride treatment also appears capable of interacting with newly applied crushed stone to reduce dust generation. Two additional one mile test roads were to have been constructed early this year. Due to an extremely dry spring and summer, construction scheduling was not possible until August. This would have allowed only minimal data collection. Considering this and the fact that this was an atypically dry summer, it was our opinion that it would be in the best interest of the research project to extend the project (at no additional cost) for a period of one year. The two additional test roads will be constructed in early spring 1989 in Adair and Marion counties.

Exploring the feasibility of applying data mining for library reference service improvement : a case study of Turku Main Library

Data mining, as a heatedly discussed term, has been studied in various fields. Its possibilities in refining the decision-making process, realizing potential patterns and creating valuable knowledge have won attention of scholars and practitioners. However, there are less studies intending to combine data mining and libraries where data generation occurs all the time. Therefore, this thesis plans to fill such a gap. Meanwhile, potential opportunities created by data mining are explored to enhance one of the most important elements of libraries: reference service. In order to thoroughly demonstrate the feasibility and applicability of data mining, literature is reviewed to establish a critical understanding of data mining in libraries and attain the current status of library reference service. The result of the literature review indicates that free online data resources other than data generated on social media are rarely considered to be applied in current library data mining mandates. Therefore, the result of the literature review motivates the presented study to utilize online free resources. Furthermore, the natural match between data mining and libraries is established. The natural match is explained by emphasizing the data richness reality and considering data mining as one kind of knowledge, an easy choice for libraries, and a wise method to overcome reference service challenges. The natural match, especially the aspect that data mining could be helpful for library reference service, lays the main theoretical foundation for the empirical work in this study. Turku Main Library was selected as the case to answer the research question: whether data mining is feasible and applicable for reference service improvement. In this case, the daily visit from 2009 to 2015 in Turku Main Library is considered as the resource for data mining. In addition, corresponding weather conditions are collected from Weather Underground, which is totally free online. Before officially being analyzed, the collected dataset is cleansed and preprocessed in order to ensure the quality of data mining. Multiple regression analysis is employed to mine the final dataset. Hourly visits are the independent variable and weather conditions, Discomfort Index and seven days in a week are dependent variables. In the end, four models in different seasons are established to predict visiting situations in each season. Patterns are realized in different seasons and implications are created based on the discovered patterns. In addition, library-climate points are generated by a clustering method, which simplifies the process for librarians using weather data to forecast library visiting situation. Then the data mining result is interpreted from the perspective of improving reference service. After this data mining work, the result of the case study is presented to librarians so as to collect professional opinions regarding the possibility of employing data mining to improve reference services. In the end, positive opinions are collected, which implies that it is feasible to utilizing data mining as a tool to enhance library reference service.

Processing Argo oxygen data at the DAC level cookbook

This document does NOT address the issue of oxygen data quality control (either real-time or delayed mode). As a preliminary step towards that goal, this document seeks to ensure that all countries deploying floats equipped with oxygen sensors document the data and metadata related to these floats properly. We produced this document in response to action item 14 from the AST-10 meeting in Hangzhou (March 22-23, 2009). Action item 14: Denis Gilbert to work with Taiyo Kobayashi and Virginie Thierry to ensure DACs are processing oxygen data according to recommendations. If the recommendations contained herein are followed, we will end up with a more uniform set of oxygen data within the Argo data system, allowing users to begin analysing not only their own oxygen data, but also those of others, in the true spirit of Argo data sharing. Indications provided in this document are valid as of the date of writing this document. It is very likely that changes in sensors, calibrations and conversions equations will occur in the future. Please contact V. Thierry (vthierry@ifremer.fr) for any inconsistencies or missing information. A dedicated webpage on the Argo Data Management website (www) contains all information regarding Argo oxygen data management : current and previous version of this cookbook, oxygen sensor manuals, calibration sheet examples, examples of matlab code to process oxygen data, test data, etc..

Active Data Collection Techniques to Understand Online Scammers and Cybercriminals

Nigerian scam, also known as advance fee fraud or 419 scam, is a prevalent form of online fraudulent activity that causes financial loss to individuals and businesses. Nigerian scam has evolved from simple non-targeted email messages to more sophisticated scams targeted at users of classifieds, dating and other websites. Even though such scams are observed and reported by users frequently, the community’s understanding of Nigerian scams is limited since the scammers operate “underground”. To better understand the underground Nigerian scam ecosystem and seek effective methods to deter Nigerian scam and cybercrime in general, we conduct a series of active and passive measurement studies. Relying upon the analysis and insight gained from the measurement studies, we make four contributions: (1) we analyze the taxonomy of Nigerian scam and derive long-term trends in scams; (2) we provide an insight on Nigerian scam and cybercrime ecosystems and their underground operation; (3) we propose a payment intervention as a potential deterrent to cybercrime operation in general and evaluate its effectiveness; and (4) we offer active and passive measurement tools and techniques that enable in-depth analysis of cybercrime ecosystems and deterrence on them. We first created and analyze a repository of more than two hundred thousand user-reported scam emails, stretching from 2006 to 2014, from four major scam reporting websites. We select ten most commonly observed scam categories and tag 2,000 scam emails randomly selected from our repository. Based upon the manually tagged dataset, we train a machine learning classifier and cluster all scam emails in the repository. From the clustering result, we find a strong and sustained upward trend for targeted scams and downward trend for non-targeted scams. We then focus on two types of targeted scams: sales scams and rental scams targeted users on Craigslist. We built an automated scam data collection system and gathered large-scale sales scam emails. Using the system we posted honeypot ads on Craigslist and conversed automatically with the scammers. Through the email conversation, the system obtained additional confirmation of likely scam activities and collected additional information such as IP addresses and shipping addresses. Our analysis revealed that around 10 groups were responsible for nearly half of the over 13,000 total scam attempts we received. These groups used IP addresses and shipping addresses in both Nigeria and the U.S. We also crawled rental ads on Craigslist, identified rental scam ads amongst the large number of benign ads and conversed with the potential scammers. Through in-depth analysis of the rental scams, we found seven major scam campaigns employing various operations and monetization methods. We also found that unlike sales scammers, most rental scammers were in the U.S. The large-scale scam data and in-depth analysis provide useful insights on how to design effective deterrence techniques against cybercrime in general. We study underground DDoS-for-hire services, also known as booters, and measure the effectiveness of undermining a payment system of DDoS Services. Our analysis shows that the payment intervention can have the desired effect of limiting cybercriminals’ ability and increasing the risk of accepting payments.

THERMAL VACUUM TEST CORRELATION OF A ZERO PROPELLANT LOAD CASE THERMAL CAPACITANCE PROPELLANT GAUGING ANALYTICAL MODEL

This thesis describes the development and correlation of a thermal model that forms the foundation of a thermal capacitance spacecraft propellant load estimator. Specific details of creating the thermal model for the diaphragm propellant tank used on NASA’s Magnetospheric Multiscale spacecraft using ANSYS and the correlation process implemented are presented. The thermal model was correlated to within +/- 3 Celsius of the thermal vacuum test data, and was determined sufficient to make future propellant predictions on MMS. The model was also found to be relatively sensitive to uncertainties in applied heat flux and mass knowledge of the tank. More work is needed to improve temperature predictions in the upper hemisphere of the propellant tank where predictions were found to be 2-2.5 Celsius lower than the test data. A road map for applying the model to predict propellant loads on the actual MMS spacecraft in 2017-2018 is also presented.

Uma abordagem dirigida a modelo para a geração de casos de teste baseada na detecção de cenários implícitos

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2015.

A medida e as escalas de avaliação da saúde das populações neonatais e pediátricas : estudo de simulação de Monte Carlo com variáveis ordinais

A investigação na área da saúde e a utilização dos seus resultados tem funcionado como base para a melhoria da qualidade de cuidados, exigindo dos profissionais de saúde conhecimentos na área específica onde desempenham funções, conhecimentos em metodologia de investigação que incluam as técnicas de observação, técnicas de recolha e análise de dados, para mais facilmente serem leitores capacitados dos resultados da investigação. Os profissionais de saúde são observadores privilegiados das respostas humanas à saúde e à doença, podendo contribuir para o desenvolvimento e bem-estar dos indivíduos muitas vezes em situações de grande vulnerabilidade. Em saúde infantil e pediatria o enfoque está nos cuidados centrados na família privilegiando-se o desenvolvimento harmonioso da criança e jovem, valorizando os resultados mensuráveis em saúde que permitam determinar a eficácia das intervenções e a qualidade de saúde e de vida. No contexto pediátrico realçamos as práticas baseadas na evidência, a importância atribuída à pesquisa e à aplicação dos resultados da investigação nas práticas clínicas, assim como o desenvolvimento de instrumentos de mensuração padronizados, nomeadamente as escalas de avaliação, de ampla utilização clínica, que facilitam a apreciação e avaliação do desenvolvimento e da saúde das crianças e jovens e resultem em ganhos em saúde. A observação de forma sistematizada das populações neonatais e pediátricas com escalas de avaliação tem vindo a aumentar, o que tem permitido um maior equilíbrio na avaliação das crianças e também uma observação baseada na teoria e nos resultados da investigação. Alguns destes aspetos serviram de base ao desenvolvimento deste trabalho que pretende dar resposta a 3 objetivos fundamentais. Para dar resposta ao primeiro objetivo, “Identificar na literatura científica, os testes estatísticos mais frequentemente utilizados pelos investigadores da área da saúde infantil e pediatria quando usam escalas de avaliação” foi feita uma revisão sistemática da literatura, que tinha como objetivo analisar artigos científicos cujos instrumentos de recolha de dados fossem escalas de avaliação, na área da saúde da criança e jovem, desenvolvidas com variáveis ordinais, e identificar os testes estatísticos aplicados com estas variáveis. A análise exploratória dos artigos permitiu-nos verificar que os investigadores utilizam diferentes instrumentos com diferentes formatos de medida ordinal (com 3, 4, 5, 7, 10 pontos) e tanto aplicam testes paramétricos como não paramétricos, ou os dois em simultâneo, com este tipo de variáveis, seja qual for a dimensão da amostra. A descrição da metodologia nem sempre explicita se são cumpridas as assunções dos testes. Os artigos consultados nem sempre fazem referência à distribuição de frequência das variáveis (simetria/assimetria) nem à magnitude das correlações entre os itens. A leitura desta bibliografia serviu de suporte à elaboração de dois artigos, um de revisão sistemática da literatura e outro de reflexão teórica. Apesar de terem sido encontradas algumas respostas às dúvidas com que os investigadores e os profissionais, que trabalham com estes instrumentos, se deparam, verifica-se a necessidade de desenvolver estudos de simulação que confirmem algumas situações reais e alguma teoria já existente, e trabalhem outros aspetos nos quais se possam enquadrar os cenários reais de forma a facilitar a tomada de decisão dos investigadores e clínicos que utilizam escalas de avaliação. Para dar resposta ao segundo objetivo “Comparar a performance, em termos de potência e probabilidade de erro de tipo I, das 4 estatísticas da MANOVA paramétrica com 2 estatísticas da MANOVA não paramétrica quando se utilizam variáveis ordinais correlacionadas, geradas aleatoriamente”, desenvolvemos um estudo de simulação, através do Método de Monte Carlo, efetuado no Software R. O delineamento do estudo de simulação incluiu um vetor com 3 variáveis dependentes, uma variável independente (fator com três grupos), escalas de avaliação com um formato de medida com 3, 4, 5, e 7 pontos, diferentes probabilidades marginais (p1 para distribuição simétrica, p2 para distribuição assimétrica positiva, p3 para distribuição assimétrica negativa e p4 para distribuição uniforme) em cada um dos três grupos, correlações de baixa, média e elevada magnitude (r=0.10, r=0.40, r=0.70, respetivamente), e seis dimensões de amostras (n=30, 60, 90, 120, 240, 300). A análise dos resultados permitiu dizer que a maior raiz de Roy foi a estatística que apresentou estimativas de probabilidade de erro de tipo I e de potência de teste mais elevadas. A potência dos testes apresenta comportamentos diferentes, dependendo da distribuição de frequência da resposta aos itens, da magnitude das correlações entre itens, da dimensão da amostra e do formato de medida da escala. Tendo por base a distribuição de frequência, considerámos três situações distintas: a primeira (com probabilidades marginais p1,p1,p4 e p4,p4,p1) em que as estimativas da potência eram muito baixas, nos diferentes cenários; a segunda situação (com probabilidades marginais p2,p3,p4; p1,p2,p3 e p2,p2,p3) em que a magnitude das potências é elevada, nas amostras com dimensão superior ou igual a 60 observações e nas escalas com 3, 4,5 pontos e potências de magnitude menos elevada nas escalas com 7 pontos, mas com a mesma ma magnitude nas amostras com dimensão igual a 120 observações, seja qual for o cenário; a terceira situação (com probabilidades marginais p1,p1,p2; p1,p2,p4; p2,p2,p1; p4,p4,p2 e p2,p2,p4) em que quanto maiores, a intensidade das correlações entre itens e o número de pontos da escala, e menor a dimensão das amostras, menor a potência dos testes, sendo o lambda de Wilks aplicado às ordens mais potente do que todas as outra s estatísticas da MANOVA, com valores imediatamente a seguir à maior raiz de Roy. No entanto, a magnitude das potências dos testes paramétricos e não paramétricos assemelha-se nas amostras com dimensão superior a 90 observações (com correlações de baixa e média magnitude), entre as variáveis dependentes nas escalas com 3, 4 e 5 pontos; e superiores a 240 observações, para correlações de baixa intensidade, nas escalas com 7 pontos. No estudo de simulação e tendo por base a distribuição de frequência, concluímos que na primeira situação de simulação e para os diferentes cenários, as potências são de baixa magnitude devido ao facto de a MANOVA não detetar diferenças entre grupos pela sua similaridade. Na segunda situação de simulação e para os diferentes cenários, a magnitude das potências é elevada em todos os cenários cuja dimensão da amostra seja superior a 60 observações, pelo que é possível aplicar testes paramétricos. Na terceira situação de simulação, e para os diferentes cenários quanto menor a dimensão da amostra e mais elevada a intensidade das correlações e o número de pontos da escala, menor a potência dos testes, sendo a magnitude das potências mais elevadas no teste de Wilks aplicado às ordens, seguido do traço de Pillai aplicado às ordens. No entanto, a magnitude das potências dos testes paramétricos e não paramétricos assemelha-se nas amostras com maior dimensão e correlações de baixa e média magnitude. Para dar resposta ao terceiro objetivo “Enquadrar os resultados da aplicação da MANOVA paramétrica e da MANOVA não paramétrica a dados reais provenientes de escalas de avaliação com um formato de medida com 3, 4, 5 e 7 pontos, nos resultados do estudo de simulação estatística” utilizaram-se dados reais que emergiram da observação de recém-nascidos com a escala de avaliação das competências para a alimentação oral, Early Feeding Skills (EFS), o risco de lesões da pele, com a Neonatal Skin Risk Assessment Scale (NSRAS), e a avaliação da independência funcional em crianças e jovens com espinha bífida, com a Functional Independence Measure (FIM). Para fazer a análise destas escalas foram realizadas 4 aplicações práticas que se enquadrassem nos cenários do estudo de simulação. A idade, o peso, e o nível de lesão medular foram as variáveis independentes escolhidas para selecionar os grupos, sendo os recém-nascidos agrupados por “classes de idade gestacional” e por “classes de peso” as crianças e jovens com espinha bífida por “classes etárias” e “níveis de lesão medular”. Verificou-se um bom enquadramento dos resultados com dados reais no estudo de simulação.

Fighting child marriage in developing countries: design and development of a mobile application

Child marriage is still a great issue in developing countries and even if the interventions to prevent it are having results, they are not enough to eliminate the problem. Among the strategies that seem to work most to fight child marriage, there is the empowerment of girls with information combined with education of parents and community. As smartphones are more accessible year after year in developing countries, this thesis wants to investigate if a mobile app could be effective in fighting child marriage and which characteristics such an app should have. The research was organized in four phases and used design and creation and case study methodologies. Firstly, the literature was analyzed and an initial design was proposed. Secondly, expert interviews were performed to gain feedback on the proposed design, and afterwards prototype was built. Thirdly, a case study in the Democratic Republic of Congo (DRC) was performed to test the prototype, gaining insights and improvements through group interviews with 26 girls aged 15-19. Finally, a first version of the app was developed and a second phase of the case study was run in the DRC to understand if the girls were able to use the app. This phase included 14 girls of which 6 had participated in the prototype testing and used questionnaires as a data generation method. The app was built following the Principles for Digital Development. Even if this app is built based on the case study in DRC is modular and easily adaptable to other contexts as it is not content-specific. It was shown that is worth continuing to study this topic and it was defined a conceptual framework for designing learning apps for developing countries, in particular, to fight child, early, and forced marriage.

Adhesion of Epiphany and AH Plus sealers to human root dentin treated with different solutions

This study evaluated comparatively the adhesion of Epiphany and AH Plus endodontic sealers to human root dentin treated with 1% NaOCl and 1% NaOCl+17% EDTA, using the push-out test. Sixty root cylinders obtained from maxillary canines had the canals prepared and were randomly assigned to 3 groups (n=20), according to root dentin treatment: GI - distilled water (control), GII - 1% NaOCl and GIII - 1% NaOCl+17% EDTA. Each group was divided into 2 subgroups (n=10) filled with either Epiphany or AH Plus. Bond strength push-out test data (kN) were obtained and analyzed statistically by ANOVA and Tukey's post-hoc test. There was statistically significant difference between sealers (AH Plus: 0.78 ± 0.13; Epiphany: 0.61 ± 0.19; p<0.01) and among root dentin treatments (distilled water: 0.58 ± 0.19; 1% NaOCl: 0.71 ± 0.12; 1% NaOCl+17% EDTA: 0.80 ± 0.17; p<0.05). In conclusion, AH Plus sealer presented greater adhesion to dentin than Epiphany, regardless of the treatment of root canal walls.

Prevalence of diabetes mellitus and impaired glucose tolerance in a rural community of Angola

Background: To determine the prevalence of diabetes mellitus (DM) and impaired glucose tolerance (IGT) in a rural community (Bengo) of Angola. Methods: A random sample of 421 subjects aged 30 to 69 years (30% men and 70% women) was selected from three villages of Bengo province. This cross-sectional home survey was conducted using a sampling design of stage conglomerates. First, clinical and anthropometric data were obtained and fasting capillary glucose level was determined. Subjects who screened positive (fasting capillary glucose >= 100 mg/dl and < 200 mg/dl) and each sixth consecutive subject who screened negative (fasting capillary glucose < 100 mg/dl) were submitted to the second phase of survey, consisting of the 75 g oral glucose tolerance test. Data was analyzed by the use of SAS statistical software. Results: The prevalence rates of diabetes mellitus and IGT were 2.8% and 8.1%, respectively. The age group with the highest prevalence of diabetes was 60 to 69 years (42%). Impaired glucose tolerance prevalence was 38% in the 40 to 49 year age group and it increased with age, considering that the 50 to 59 and 60 to 69 year age groups as a whole represent 50% of all subjects with impaired glucose tolerance. The prevalence of diabetes mellitus did not differ significantly between men (3.2%) and women (2.7%) (p = 0.47). On the other hand, the prevalence of impaired glucose tolerance among women showed almost twice that found in men (9.1% vs. 5.6%, respectively). Overweight was present in 66.7% of the individuals with diabetes mellitus and 26.5% of individuals with impaired glucose tolerance showed overweight or obesity. Conclusions: Although the prevalence of diabetes mellitus was low, the prevalence of impaired glucose tolerance is considered to be within an intermediary range, suggesting a future increase in the frequency of diabetes in this population.

Adaptable Strut-and-Tie Model for Design and Verification of Four-Pile Caps

A large percentage of pile caps support only one column, and the pile caps in turn are supported by only a few piles. These are typically short and deep members with overall span-depth ratios of less than 1.5. Codes of practice do not provide uniform treatment for the design of these types of pile caps. These members have traditionally been designed as beams spanning between piles with the depth selected to avoid shear failures and the amount of longitudinal reinforcement selected to provide sufficient flexural capacity as calculated by the engineering beam theory. More recently, the strut-and-tie method has been used for the design of pile caps (disturbed or D-region) in which the load path is envisaged to be a three-dimensional truss, with compressive forces being supported by concrete compressive struts between the column and piles and tensile forces being carried by reinforcing steel located between piles. Both of these models have not provided uniform factors of safety against failure or been able to predict whether failure will occur by flexure (ductile mode) or shear (fragile mode). In this paper, an analytical model based on the strut-and-tie approach is presented. The proposed model has been calibrated using an extensive experimental database of pile caps subjected to compression and evaluated analytically for more complex loading conditions. It has been proven to be applicable across a broad range of test data and can predict the failures modes, cracking, yielding, and failure loads of four-pile caps with reasonable accuracy.