Passive cooling of cement-based roofs in tropical climates

In tropical climates, dwellings are made of cement-based materials like concrete to be able to withstand tropical storms and severe weather conditions. However, cement-based materials exhibit undesirable thermal properties including low thermal conductivity and thermal diffusivity which make living conditions almost unbearable. The purpose of this research project was to investigate the impact of a newly designed passive cooling system which can minimize heat transfer through concrete roofs. The passive cooling system consists of a corrugated aluminum sheet with a unique orientation to promote heat dissipation. A layer polyurethane is also used to minimize heat transfer. Experimental results based on lab-scale prototypes show that the well-designed roof insulation system can reduce the typical thermal load by over 70%. The passive cooling system also shows a desirable slow response time to irradiation, which is a desirable characteristic necessary to effectively control thermal fluctuations and reduce thermal loads simultaneously. The results also indicate that the cement-based roof midpoint temperature can be modeled accurately using an appropriate empirical model.     

Proposal of residency integrated with medical masters degree at the UFMG Medical School: an evaluation among residents

A project which integrates medical RESIDENCY with medical masters degree has been discussed and is expected to be set up at UFMG Medical School in the near future. Such project is optional for the entering residents and aims those who are interested in becoming researchers. This paper's objective is to raise the residents' opinion on the project as well as their interests in post graduation level. A 240 university hospital residents (HC-UFMG) and a 114 non-university hospital (IPSEMG) were studied through questionnaire application. From the total population of 354 residents we had a 50% questionnaire devolution, 120 (68%) from HC-UFMG and 57 (32%) from IPSEMG. Residents of different clinical and surgical areas were included, 55% male and 45% female. Most of them work exclusively in residency activities, 69% have interest in specialize after residency, 55% in taking medical masters degree, 52% in taking up academic life and 67% in applying for the integrated residency-master degree program. Twelve (7%) are not particularly interested in join the program because they are not sure whether they are able to carry on adequately both residency and research activities at the same time. This study shows that residents are highly receptive to the UFMG's program and that more detailed information concerning its contents should be handed out in order to generate further discussion.     

Recent experience with fortification of foods and beverages with iron for the control of iron-deficiency anemia in Brazilian children

Iron-deficiency-anemia affects 30% of the world population. Women of reproductive age and children are the most affected. Iron supplementation in the form of tablets and syrups has not been successful in developing countries, and iron deficiency is still the most important deficiency related to malnutrition. Iron-deficiency anemia affects physical and cognitive development at an early age in children, often resulting in irreversible outcomes. Studies from the last two decades have shown that the prevalence of iron-deficiency anemia can be reduced given adequate investments and political will directed at iron fortification of foods and liquids. A successful low-cost iron-fortification program incorporates implementation and strategic use of communication for program inception where education is in the forefront. A review of the available reports from experience in Brazil with iron fortification of foods and liquids is presented.     

Conventional low-density particleboards produced from Mauritia flexuosa and Eucalyptus spp. wood

Clean Technologies and Environmental Policy - The use of alternative raw materials to produce particleboards is an interesting strategy that adds value to lignocellulosic biomass and diversifies...     

Analysis of fiber blends using horizontal attenuated total reflection Fourier transform infrared and discriminant analysis

We have investigated the utility of a horizontal attenuated total reflection Fourier transform infrared spectrometer (HATR/FT-IR) for the analysis of fiber and textile blends. The identification of a blended textile can be accomplished by subtracting a reference spectrum of the textile's most abundant component, leading to a difference spectrum that infers the identity of the second constituent of the blended textile. Mathematical post-processing of the spectra employing discriminant analysis provided a useful statistical tool to confirm the fiber blend components.     

A Multi-stage Online Signature Verification System

: This paper presents a new three-stage verification system which is based on three types of features: global features; local features of the corner points; and function features that contain information of each point of the signatures. The first verification stage implements a parameter-based method, in which the Mahalanobis distance is used as a dissimilarity measure between the signatures. The second verification stage involves corner extraction and corner matching. It also performs signature segmentation. The third verification stage implements a function-based method, which is based on an elastic matching algorithm establishing a point-to-point correspondence between the compared signatures. By combining the three different types of verification, a high security level can be reached. According to our experiments, the rates of false rejection and false acceptance are, respectively, 5.8% and 0%. Received: 12 Febuary 2001, Received in revised form: 24 May 2001, Accepted: 03 July 2001     

山东省工业用电单耗分析

对山东省工业发展及用电状况进行分析,计算出山东省工业及工业14个主要行业的用电单耗；根据工业用电单耗和各行业用电单耗的变化．分析经济结构调整、科学技术进步、能源结构调整等因素对工业用电单耗的影响分析结果表明．经济结构调整和科学技术进步是促使工业用电单耗不断下降的主要动力;能源结构调整也会对工业用电单耗产生影响.     

Glucose Uptake and Triacylglycerol Synthesis Are Increased in Barth Syndrome Lymphoblasts

Barth syndrome (BTHS) is an X-linked genetic disease resulting in loss of cardiolipin (Ptd₂Gro). Patients may be predisposed to hypoglycemia and exhibit increases in whole-body glucose disposal rates and a higher fat mass percentage. We examined the reasons for this in BTHS lymphoblasts. BTHS lymphoblasts exhibited a 60% increase (p < 0.004) in 2-[1,2-³H(N)]deoxy-d-glucose uptake, a 40% increase (p < 0.01) in glucose transporter-3 protein expression, an increase in phosphorylated-adenosine monophosphate kinase (AMPK) and a 58% increase (p < 0.001) in the phosphorylated-AMPK/AMPK ratio compared to controls. In addition, BTHS lymphoblasts exhibited a 90% (p < 0.001) increase in d-[U-¹⁴C]glucose incorporated into 1,2,3-triacyl-sn-glycerol (TAG) and a 29% increase (p < 0.025) in 1,2-diacyl-sn-glycerol acyltransferase-2 activity compared to controls. Thus, BTHS lymphoblasts exhibit increased glucose transport and increased glucose utilization for TAG synthesis. These results may, in part, explain why BTHS patients exhibit an increase in whole-body glucose disposal rates, may be predisposed to hypoglycemia and exhibit a higher fat mass percentage.     

Induced Magnetic Field Used to Detect the Sigma Phase of a 2205 Duplex Stainless Steel

Sigma phases are formed due to heat treatments and/or welding processes during the solidification stage, and they are responsible for embrittlement of duplex stainless steels. Only a small amount of this phase promotes unfavorable mechanical properties and liability to corrosion. In this work, a new affordable approach to detect and follow-up the kinetics of the sigma phase transformation is evaluated. The measurements are based on an induced magnetic field generated through the interaction between an external magnetic field and the microstructure under study. To validate this approach, the induced magnetic field values are compared with the values of the Charpy impact energy, and the sigma phase is assessed by optical microscopy. Moreover, surface fractures are analyzed by scanning electron microscopy and X-ray diffraction. The results from the 2205 duplex stainless steel used show that there is a direct relation among the impact energy, fracture mechanism and induced magnetic field. The method proved to be able to follow up the embrittlement of the DSS successfully. Moreover, the results confirm that the presence of a sigma phase can be studied based on an induced magnetic field, even when in low amounts, and that a critical threshold value can be defined to monitor structures in service.