88 research outputs found
A Comparative Simulation Study of the Thermal Performances of the Building Envelope Wall Materials in the Tropics
he building walls which form the major part of the building envelope thermally interact with the changing surrounding environment throughout the day influencing the indoor thermal comfort of the space. This paper aims at assessing in detail the different aspects (thermophysical properties, thickness, exposure to solar heat gain, etc.) of opaque building wall materials affecting the indoor thermal environment and energy efficiency of the buildings in tropical climate (in the summer and winter days) by conducting simplified simulation analysis using the Integrated Environmental Solutions Virtual Environment (IES-VE) program. Besides, the thermal efficiency of a number of selected wall materials with different thermal properties and wall configurations was analysed to determine the most optimal option for the studied climate. This study first developed the conditions for parametric simulation analysis and then addressed selected findings by comparing the thermal responses of the materials to moderate outdoor temperature and energy-saving potential. While energy consumption estimation for a complete operational building is a complex method by which the performance of the wall materials cannot be properly defined, as a result, this simplistic simulation approach can guide the designers to preliminary analyse the different building wall materials in order to select the best thermal efficiency solution
Total Antioxidant Activity, and Hesperidin, Diosmin, Eriocitrin and Quercetin Contents of Various Lemon Juices
Purpose: To investigate 38 natural and 62 branded lemon juices for their total antioxidant activities and flavonoid content.Methods: The ferric reducing antioxidant power was applied to evaluation of antioxidant. Additionally quercetin, eriocitrin, diosmin and hesperidin contents were evaluated by high performance liquid chromatography (HPLC).Results: Total antioxidant activity of the juices ranged from 91.38 Ā± 0.01 to 526.93 Ā± 0.12 Ī¼g/ml. The maximum contents of quercetin, hesperidin and eriocitrin 14.83 Ā± 2.83, 104.84 Ā± 12.58 and 10.68 Ā± 2.41 Ī¼g/mL, respectively. The natural juices had diosmin levels as high as 236.18 mL. The limit of detection (LOD) ranged from 0.15 Ī¼g mg-1 for hesperidine to 0.53 Ī¼g ml-1 for diosmin while the limit of quantification (LOQ) ranged from 0.27 Ī¼g mg-1 for hesperidine to 0.93 Ī¼g ml-1 for quercetin.Conclusion: The developed method can also be applied to the determination of related extracts of orange cultivars as well as various extracts of medicinal plants.Keywords: Antioxidant, Flavonoid, Hesperidin, Diosmin, Eriocitrin, Quercetin, Lemon juic
Profiling of major fatty acids in different raw and roasted sesame seeds cultivars
The aim of this study was to investigate the fatty acids profile of five sesame cultivars including Branching Naz, Darab, Karaj, Dezful and Black sesame and the effect of time and temperature roasting procedure. The seeds oil content varied from 43Ā±0.28 to 47Ā±0.41% with the average content of 44.4Ā±1.87%. Darab and Black sesame cultivar had the highest and lowest oil content respectively. Oleic and linoleic acids were the two-dominant fatty acids in the sesame seed oil about 80 to 85% of the total amount, whereas palmitic and stearic acids were present at 12 to 15%. Moreover, Dazful and Black sesame had the maximum and minimum content of oxidizability value respectively. The results of the present study showed that the fatty acid contents in studied cultivars were steady during different roasting conditions and fatty acid behavior of samples was good fitted with the high temperatures.Key words: Gas chromatography (GC), fatty acid, roasting procedure, sesame seed, stability
Application of agro and non-agro waste materials for unfired earth blocks construction: A review
The production process of conventional building materials consumes a high amount of energy which has a negative impact on the environment. The use of locally available materials and upgradation of traditional techniques can be a good option for sustainable development. Consequently, earth has attracted the attention of the researchers as a building construction material for its availability and lower environmental impact. On the other hand, in developing countries waste disposal from the agricultural and industrial sectors raises another serious concern. The scientists have introduced such waste additives into the earth matrix to improve its performance. Therefore, the present paper reviews the state-of-the-art of research on the effects of these various agro and non-agro wastes in the production of unfired earth blocks. This study is divided into three sections: The first section outlines the different types of waste materials and earth blocks considered in the selected papers. The second part deals in depth with the test results of the different properties (density, water absorption, compressive strength, flexural strength and thermal conductivity) of unfired earth blocks containing waste materials. The last section analyses and compares the results with the current earth-building construction standards. The literature survey presents that the waste materials have a clear potential to partly replace earth by complying with certain requirements. Moreover, the application of such wastes for the development of building construction materials provides a solution that decreases energy usage as well as contributes to effective waste management. Future research on establishing guidelines and standards for the development and production of these sustainable unfired earth building materials is recommended
The effects of yogurt supplementation and nutritional education on malnourished infants : a pilot RCT in Dhaka's slums
Our objective was to quantify the effects of yogurt supplementation and nutrition education over three months on the linear growth of infants at risk of stunting. We conducted a three-arm pilot randomized controlled trial: (1) nutrition education for mothers; (2) nutrition education plus a daily yogurt supplement (50 g) for the index child; and (3) usual care (control). Dyads of children aged 4ā6 months and at risk of stunting [length-for-age z-score (LAZ) ā¤ ā1 SD and >ā2 SD] and their mothers with ā¤10 years of education were eligible for the study. Participants were recruited from five slum areas in Dhaka, Bangladesh. Intention-to-treat (N = 162) and complete-case analyses (N = 127) showed no between-group statistically significant differences in LAZ or weight-for-age (WAZ). However, the yogurt group showed greater change in linear growth compared to the control (LAZ: mean difference 0.20, 95% CI: ā0.06, 0.47, p-value 0.13), which was also slightly greater than the education-only group. Children in the yogurt plus group were five times (95% CI: 0.80, 31.80, p-value 0.09) more likely to meet the minimum dietary diversity (MDD) score compared to the control. A 3-month follow-up of this pilot study did not demonstrate that yogurt was beneficial to linear growth. However, there were encouraging trends that merit replication of the intervention with larger samples and longer follow-ups
Evaluation of Fast-food and Prepared Food Contamination with Health Pests
Background: Biologic and pathogenic contamination of food is the most important cause of illness and death in developing countries. Providing food security during the food preparation for restaurants and self-services is very important. The aim of this study was to determine level of prepared food contamination with egg, larvae and adult insects, or other health pests. Methods: In a period of 3 years, samples of food (26) suspected to be contaminated with biological agents related to various restaurants and universitiesĆ¢ļæ½ļæ½ self-services and were investigated. Organs or larval stages of insects were isolated and were later cleaned using water. The samples were identified using a stereo microscope. The results were compared using images and tables. Results: Contaminated food and fast food including kabab koobideh and celery stew respectively accounted for highest (19) and lowest (1 case) contamination rate in the present study. The contamination rate of the other studied foods was as follow: Rice and raw milk each respectively 15.5, Kale pache and soup each 11.5, Ghorme sabzi, khorest-e-gheyme and hamburger each with 7.7. Conclusion: Supply of primary healthy food sources and securing food safety during preparation as well as complete and accurate maintenance of food up to the consumption phase are among the most important measures to be considered to prevent food contamination with insect larvae. Copyright (c) 2018 Journal of Communicable Disease
Thermophysical Properties of Sawdust and Coconut Coir Dust Incorporated Unfired Clay Blocks
Sawdust and coconut coir dust are agro-wastes/by-products which are suitable for use as raw materials to manufacture unfired clay blocks due to their excellent physical and mechanical properties. A limited number of studies have been conducted on the utilisation of these agro-wastes in clay block production, and they have mostly been devoted to investigating the physicomechanical properties, with less attention given to the thermal properties. Moreover, the majority of the studies have used chemical binders (cement and lime) in combination with agro-waste, thus increasing the carbon footprint and embodied energy of the samples. Furthermore, no research has been performed on the thermal performance of these agro-wastes when incorporated into clay blocks at the wall scale. Therefore, to address these limitations, the present study developed unfired clay blocks incorporating sawdust and coconut coir dust (0, 2.5, 5, and 7.5% by weight), without the use of chemical binders, and evaluated their thermal performance, both at the individual and wall scales. The experiments were divided into two phases. In the first phase, individual sample blocks was tested for basic thermal properties. Based on the results of the first phase, small walls with dimensions of 310 mm Ć 215 mm Ć 100 mm were built in the second phase, using the best performing mixture from each waste type, and these were assessed for thermal performance using an adapted hot box method. The thermal performance of the walls was evaluated by measuring the heat transfer rate from hot to cold environments and comparing the results to the reference wall. The results showed that thermal conductivity decreased from 0.36 W/mK for the reference sample, to 0.19 W/mK for the 7.5% coconut coir dust sample, and 0.21 W/mK for the 7.5% sawdust sample, indicating an improvement in thermal insulation. Furthermore, the coconut coir dust and sawdust sample walls showed a thermal resistance improvement of around 48% and 35%, respectively, over the reference sample wall. Consequently, the findings of this study will provide additional essential information that will help in assessing the prospective applications of sawdust and coconut coir dust as the insulating material for manufacturing unfired clay blocks
Influence of Sawdust Particle Sizes on the Physico-Mechanical Properties of Unfired Clay Blocks
Sawdust, which is a waste/by-product of the wood/timber industry, can be utilised as a valuable raw material in building material production due to its abundance and low cost. However, the application of sawdust in the manufacture of unfired clay blocks has received little investigation. Furthermore, the impact of different sawdust particle sizes on the properties of unfired clay blocks has not been studied. Therefore, this study screened sawdust at three different particle sizes: SP-a (212 Ī¼m < x < 300 Ī¼m), SP-b (425 Ī¼m < x < 600 Ī¼m) and SP-c (1.18 mm < x < 2.00 mm), to examine their effects on the physical and mechanical properties of unfired clay blocks. The density, linear shrinkage, capillary water absorption and flexural and compressive strengths were among the tests performed. Different sawdust percentages, i.e., 2.5%, 5%, 7.5% and 10% of the total weight of the clay, were considered. The tests results show that when sawdust was added to the mixture, the density of the samples reduced for all particle sizes. However, the linear shrinkage increased in SP-a samples but decreased in the other two particle size samples as the sawdust percentage increased from 2.5% to 10%. On the other hand, the capillary water absorption coefficient increased while the strength decreased with increasing sawdust content for all three groups. The highest compressive strength (CS) and flexural strength (FS) were achieved at 2.5% of sawdust content. Furthermore, it was observed that SP-b (CSā4.74 MPa, FSā2.00 MPa) samples showed the highest strength followed by SP-a (CSā4.09 MPa, FSā1.69 MPa) and SP-c (CSā3.90 MPa, FSā1.63 MPa) samples. Consequently, good-quality unfired clay blocks can be manufactured using sawdust up to 2.5% with particle sizes ranging between 600 and 425 Ī¼m
The Prevalence of Cognitive Impairment Among Adults With Incident Heart Failure: The āReasons for Geographic and Racial Differences in Strokeā (REGARDS) Study
Background
Cognitive impairment (CI) is estimated to be present in 25%ā80% of heart failure (HF) patients, but its prevalence at diagnosis is unclear. To improve our understanding of cognition in HF, we determined the prevalence of CI among adults with incident HF in the REGARDS study.
Methods and Results
REGARDS is a longitudinal cohort study of adults ā„45 years of age recruited in the years 2003ā2007. Incident HF was expert adjudicated. Cognitive function was assessed with the Six-Item Screener. The prevalence of CI among those with incident HF was compared with the prevalence of CI among an age-, sex-, and race-matched cohort without HF. The 436 participants with incident HF had a mean age of 70.3 years (SD 8.9), 47% were female, and 39% were black. Old age, black race, female sex, less education, and anticoagulation use were associated with CI. The prevalence of CI among participants with incident HF (14.9% [95% CI 11.7%ā18.6%]) was similar to the non-HF matched cohort (13.4% [11.6%ā15.4%]; P < .43).
Conclusions
A total of 14.9% of the adults with incident HF had CI, suggesting that the majority of cognitive decline occurs after HF diagnosis. Increased awareness of CI among newly diagnosed patients and ways to mitigate it in the context of HF management are warranted
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Machine learning identification of thresholds to discriminate osteoarthritis and rheumatoid arthritis synovial inflammation
Background
We sought to identify features that distinguish osteoarthritis (OA) and rheumatoid arthritis (RA) hematoxylin and eosin (H&E)-stained synovial tissue samples.
Methods
We compared fourteen pathologist-scored histology features and computer vision-quantified cell density (147 OA and 60 RA patients) in H&E-stained synovial tissue samples from total knee replacement (TKR) explants. A random forest model was trained using disease state (OA vs RA) as a classifier and histology features and/or computer vision-quantified cell density as inputs.
Results
Synovium from OA patients had increased mast cells and fibrosis (p < 0.001), while synovium from RA patients exhibited increased lymphocytic inflammation, lining hyperplasia, neutrophils, detritus, plasma cells, binucleate plasma cells, sub-lining giant cells, fibrin (all p < 0.001), Russell bodies (p = 0.019), and synovial lining giant cells (p = 0.003). Fourteen pathologist-scored features allowed for discrimination between OA and RA, producing a micro-averaged area under the receiver operating curve (micro-AUC) of 0.85Ā±0.06. This discriminatory ability was comparable to that of computer vision cell density alone (micro-AUC = 0.87Ā±0.04). Combining the pathologist scores with the cell density metric improved the discriminatory power of the model (micro-AUC = 0.92Ā±0.06). The optimal cell density threshold to distinguish OA from RA synovium was 3400 cells/mm2, which yielded a sensitivity of 0.82 and specificity of 0.82.
Conclusions
H&E-stained images of TKR explant synovium can be correctly classified as OA or RA in 82% of samples. Cell density greater than 3400 cells/mm2 and the presence of mast cells and fibrosis are the most important features for making this distinction
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