Search results for: urban density

Authors: Hicham Gourgue, Ahmed Aharoune, Ahmed Ihlal

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We present in this work our model of road traffic emissions (line sources) and dispersion of these emissions, named DISPOLSPEM (Dispersion of Poly Sources and Pollutants Emission Model). In its emission part, this model was designed to keep the consistent bottom-up and top-down approaches. It also allows to generate emission inventories from reduced input parameters being adapted to existing conditions in Morocco and in the other developing countries. While several simplifications are made, all the performance of the model results are kept. A further important advantage of the model is that it allows the uncertainty calculation and emission rate uncertainty according to each of the input parameters. In the dispersion part of the model, an improved line source model has been developed, implemented and tested against a reference solution. It provides improvement in accuracy over previous formulas of line source Gaussian plume model, without being too demanding in terms of computational resources. In the case study presented here, the biggest errors were associated with the ends of line source sections; these errors will be canceled by adjacent sections of line sources during the simulation of a road network. In cases where the wind is parallel to the source line, the use of the combination discretized source and analytical line source formulas minimizes remarkably the error. Because this combination is applied only for a small number of wind directions, it should not excessively increase the calculation time.

Keywords: air pollution, dispersion, emissions, line sources, road traffic, urban transport

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Authors: Kyong-Ku Yun, Seung-Yeon Han, Kyeo-Re Lee

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Silica fume which is a super-fine byproduct of ferrosilicon or silicon metal has a filling effect on micro-air voids or a transition zone in a hardened cement paste by appropriate mixing, placement, and curing. It, also, has a Pozzolan reaction which enhances the interior density of the hydrated cement paste through a formation of calcium silicate hydroxide. When substituting cement with silica fume, it improves water tightness and durability by filling effect and Pozzolan reaction. However, it needs high range water reducer or super-plasticizer to distribute silica fume into a concrete because of its finesses and high specific surface area. In order to distribute into concrete evenly, cement manufacturers make a pre-blended cement of silica fume and provide to a market. However, a special mixing procedures and another transportation charge another cost and this result in a high price of pre-blended cement of silica fume. The purpose of this dissertation was to investigate the dispersion of silica fume by air slurry and its effect on the mechanical properties of at ready-mixed concrete. The results are as follows: A dispersion effect of silica fume was measured from an analysis of standard deviation for compressive strength test results. It showed that the standard deviation decreased as the air bubble content increased, which means that the dispersion became better as the air bubble content increased. The test result of rapid chloride permeability test showed that permeability resistance increased as the percentages of silica fume increased, but the permeability resistance decreased as the quantity of mixing air bubble increased. The image analysis showed that a spacing factor decreased and a specific surface area increased as the quantity of mixing air bubble increased.

Keywords: cellular sprayed concrete, silica fume, deviation, permeability

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Authors: Ida Ngurah

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Indonesia is one of the most prone disaster countries, which has earthquake, tsunami or high wave, flood and landslide as well as volcano eruption and drought. Disaster risk reduction has been developing extensively and comprehensively, particularly after tsunami hit in 2004. Yet, saving people live including children and youth from disaster risk is still far from succeed. Poor management of environment, poor development of policy and high level of corruption has become challenges for Indonesia to save its people from disaster impact. Indonesia is struggling to ensure its future best investment, children and youth to have better protection when disaster strike in school hours and have basic knowledge on disaster risk reduction. The program of safe school is being initiated and developed by Plan Indonesia since 2010, yet this effort still needs to be elaborated. This paper is reviewing sporadic safe school programs that have been implemented or currently being implemented Plan Indonesia in few areas of Indonesia, including both rural and urban setting. Methods used are in-depth interview with dedicated person for the program from Plan Indonesia and its implementing patners and analysis of project documents. The review includes program’s goal and objectives, implementation activity, result and achievement as well as its monitoring and evaluation scheme. Moreover, paper will be showing challenges, lesson learned and best practices of the program. Eventually, paper will come up with recommendation for strategy for better implementation of safe school program in Indonesia.

Keywords: disaster impact, safe school, programs, children, youth

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Authors: Avinash Vellore Sunder, Shikha Shah, Pramod P. Wangikar

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The enzymatic conversion of nitriles to carboxylic acids by nitrilases has gained significance in the green synthesis of several pharmaceutical precursors and fine chemicals. While nitrilases have been characterized from different sources, the industrial application requires the identification of nitrilases that possess higher substrate tolerance, wider specificity and better thermostability, along with the development of an efficient bioprocess for producing large amounts of nitrilase. To produce large amounts of nitrilase, we developed a fed-batch fermentation process on defined media for the high cell density cultivation of E. coli cells expressing the well-studied nitrilase from Alcaligenes fecalis. A DO-stat feeding approach was employed combined with an optimized post-induction strategy to achieve nitrilase titer of 2.5*105 U/l and 78 g/l dry cell weight. We also identified 16 novel nitrilase sequences from genome mining and analysis of substrate binding residues. The nitrilases were expressed in E. coli and their biocatalytic potential was evaluated on a panel of 22 industrially relevant nitrile substrates using high-throughput screening and HPLC analysis. Nine nitrilases were identified to exhibit high activity on structurally diverse nitriles including aliphatic and aromatic dinitriles, heterocyclic, -hydroxy and -keto nitriles. With fed-batch biotransformation, whole-cell Zobelia galactanivorans nitrilase achieved yields of 2.4 M nicotinic acid and 1.8 M isonicotinic acid from 3-cyanopyridine and 4-cyanopyridine respectively within 5 h, while Cupravidus necator nitrilase enantioselectively converted 740 mM mandelonitrile to (R)–mandelic acid. The nitrilase from Achromobacter insolitus could hydrolyze 542 mM iminodiacetonitrile in 1 h. The availability of highly active nitrilases along with bioprocesses for enzyme production expands the toolbox for industrial biocatalysis.

Keywords: biocatalysis, isonicotinic acid, iminodiacetic acid, mandelic acid, nitrilase

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Authors: Ari Istiany, Guspri Devi Artanti, M. Si

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Based on the results Riskesdas, it is known that breastfeeding awareness about the importance of exclusive breastfeeding is still low at only 15.3 %. These conditions resulted in a very infant at risk for infectious diseases, such as diarrhea and acute respiratory infection. Therefore, the aim of this study to evaluate the video development about exclusive breastfeeding as a nutrition education media for posyandu cadre. This research used development methods for making the video about exclusive breastfeeding. The study was conducted in urban areas Rawamangun, East Jakarta. Respondents of this study were 1 media experts from the Department of Educational Technology - UNJ, 2 subject matter experts from Department of Home Economics - UNJ and 20 posyandu cadres to assess the quality of the video. Aspects assessed include the legibility of text, image display quality, color composition, clarity of sound, music appropriateness, duration, suitability of the material and language. Data were analyzed descriptively likes frequency distribution table, the average value, and deviation standard. The result of this study showed that the average score assessment according to media experts, subject matter experts, and posyandu cadres respectively was 3.43 ± 0.51 (good), 4.37 ± 0.52 (very good) and 3.6 ± 0.73 (good). The conclusion is on exclusive breastfeeding video as feasible as a media for nutrition education. While suggestions for the improvement of visual media is multiply illustrations, add material about the correct way of breastfeeding and healthy baby pictures.

Keywords: exclusive breastfeeding, posyandu cadre, video, nutrition education

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Authors: Dijan Supramono, Eny Kusrini, Haisya Yuana

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Pyrolysis, a thermal cracking process in inert environment, may be used to produce bio-oil from biomass and plastic waste thus accommodating the use of renewable energy. Abundant amount of biomass waste in Indonesia are not utilised and plastic wastes are not well processed for clean environment. The aim of present work was to evaluate effect of mass ratio of plastic material to biomass in the feed blend of corn cobs and high density polyethylene (HDPE) of co-pyrolysis on bio-oil yield and chemical composition of bio-oil products. The heating rate of the co-pyrolysis was kept low and residence time was in the order of seconds to accommodate high yield of oil originating from plastic pyrolysis. Corn cobs have high cellulose and hemicellulose content (84%) which is potential to produce bio-oil. The pyrolysis was conducted in a laboratory-scale using a fixed bed reactor with final temperature of 500°C, heating rate 5 °C/min, flow rate N2 750 mL/min, total weight of biomass and plastic material of 20 g, and hold time after peak temperature of 30 min. Set up of conditions of co-pyrolysis should lead to accommodating the production of oil originating from HDPE due to constraint of HDPE pyrolysis residence time. Mass ratio of plastics to biomass in the feed blend was varied 0:100, 25:75, 50:50, 75:25 and 100:0. It was found that by increasing HDPE content up to 100% in the feed blend, the yield of bio-oil at different mass ratios prescribed above were 28.05, 21.55, 14.55, 9.5, and 6.3wt%, respectively. Therefore, in the fixed bed reactor, producing bio-oil is constrained by low contribution of plastic feedstock to the pyrolysis liquid yield. Furthermore, for the same variation of the mass ratio, yields of the mixture of paraffins, olefins and cycloalkanes contained in bio-oil were of 0, 28.35, 40.75, 47.17, and 67.05wt%, respectively. Olefins and cycloalkanes are easily hydrogenised to produce paraffins, suitable to be used as bio-fuel. By increasing composition of HDPE in the feed blend, viscosity and pH of bio-oil change approaching to those of commercial diesel oil.

Keywords: co-pyrolysis, corn cobs, fixed bed reactor, HDPE

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Authors: Fatai Olaitan Alao, Thimoty Abiodun Adebayo, Oladele Abiodun Olaniran

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This experiment was conducted at Ladoke Akintola University of Technology, Ogbomoso, Teaching and Research farm during the major and minor planting season , 2017 to determine the effects of Annona squamosa (Linn.) and Moringa oleifera (Lam) extracts on insect pests of watermelon and their effects on nutritional contents of watermelon fruits. Synthetic insecticide and untreated plots were included in the treatments for comparison. Selected plants were prepared with cold water and each plant extracts was applied at three different concentrations (5,10 and 20% v/v). Data were collected on population density of insect pests, number of aborted fruits, number of defoliated flowers , the yield was calculated in t/ha, nutritional and fatty acid contents were determine using gas chromatography. The results show that the two major insects were observed - Diabrotica undicimpunctata and Dacus cucurbitea. The tested plant extracts had about 65% control of the observed insect pests when compared with the control and the two plant extracts had the same insecticidal efficacy. However, the applied plant extracts at 20% v/v had higher insecticidal effects than the other tested concentrations. Significant higher yield was observed on the plant extracts treated plants compared with untreated plants which had the least yield() but none of the plant extracts performed effectively as Lambdachyalothrin in the control of insect pests and yield. Meanwhile, the tested plant extracts significantly improved the proximate and fatty acid contents of watermelon fruits while Lambdachyalothrin contributed negatively to the nutritional contents of watermelon fruits. Therefore, A. squpmosa and M. oleifera can be used in the management of insect pests and to improve the nutritional contents of the watermelon especially in the organic farming system.

Keywords: Annona squamosa, Dacus cucubitea, Diabrotical undicimpunctata, Moringa oleifera, watermelon

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Authors: Roungpaisan, N., Witthayolankowit, K., Srisawat, Srichola, P., Rungruangkitkrai, Chartvivatpornchai, Suphamitmongkol W, Lobyam, Changniam C, Boonyarit, J., , Chollakup, R.

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Thailand, a world leader in pineapple production and export, generates substantial amounts of pineapple leaf waste, a valuable source of cellulose fiber. This study investigates the production of high-quality dissolving pulp and regenerated cellulose fiber from pineapple leaf fiber using the eco-friendly lyocell process, which utilizes non-toxic, recyclable chemicals. The findings indicate that KOH can effectively replace NaOH in the pulping process, producing pulp with properties suitable for fiber spinning. Optimized bleaching sequences employing chlorine dioxide and hydrogen peroxide stages yielded bright, high-purity pulp with alpha-cellulose content comparable to commercial softwood pulp, along with higher viscosity and degree of polymerization. Lyocell fibers were successfully produced via dry-jet-wet spinning and compared to commercial lyocell fibers. These fibers exhibited similar density, color, and chemical structure but had larger dimensions, greater shrinkage, improved thermal stability, enhanced tensile strength, and superior methylene blue adsorption capacity. A market survey highlighted consumer interest in T-shirts made from sustainable lyocell fibers derived from agricultural waste, underscoring their environmental advantages. This study demonstrates a sustainable and innovative solution for repurposing agricultural waste into high-value textile products. Future work will focus on addressing the scalability and cost-efficiency of the process to facilitate its industrial application and expand its impact on sustainable textile manufacturing.

Keywords: pineapple leaf fiber, dissolving pulp, regenerated cellulose, dry-jet wet spinning

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Authors: Zhou Yang, Heli Sun, Jianbin Huang, Jizhong Zhao, Shaojie Qiao

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Traffic prediction is essential in a multitude of ways in modern urban life. The researchers of earlier work in this domain carry out the investigation chiefly with two major focuses: (1) the accurate forecast of future values in multiple time series and (2) knowledge extraction from spatial-temporal correlations. However, two key considerations for traffic prediction are often missed: the completeness of raw data and the full context of the prediction timestamp. Concentrating on the two drawbacks of earlier work, we devise an approach that can address these issues in a two-phase framework. First, we utilize the raw trajectories to a greater extent through building a VLA table and data compression. We obtain the intra-trajectory features with graph-based encoding and the intertrajectory ones with a grid-based model and the technique of back projection that restore their surrounding high-resolution spatial-temporal environment. To the best of our knowledge, we are the first to study direct feature extraction from raw trajectories for traffic prediction and attempt the use of raw data with the least degree of reduction. In the prediction phase, we provide a broader context for the prediction timestamp by taking into account the information that are around it in the training dataset. Extensive experiments on several well-known datasets have verified the effectiveness of our solution that combines the strength of raw trajectory data and prediction context. In terms of performance, our approach surpasses several state-of-the-art methods for traffic prediction.

Keywords: traffic prediction, raw data utilization, context building, data reduction

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Authors: Setapo Moloi, Jun-Ichiro Giorgos Tsutsumi

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South Africa’s need for the provision of housing within its major city centres, specifically Gauteng Province (GP), is a major concern. Initiatives for converting misused/ unused buildings to suitable housing for residents who work in the city as well as prospective citizens are currently underway, one aspect that is needed currently, is the re-possession of these buildings repurposing, into housing communities for quality low cost mixed density housing and for this process to have minimal strain on existing infrastructure like energy, emission reduction etc. Unfortunately, there are instances in Johannesburg, the country’s economic capital, with 2017 estimates claiming that 700 buildings lay unused or misused due to issues that will be discussed in this paper, these then become hubs for illegal activity and are an unacceptable form of shelter. It can be argued that the provision of inner-city social housing is lacking, but not due to the unavailability of funding or usable land and buildings, but that these assets are not being used appropriately nor to their full potential. Currently the GP government has mandated the re-purposing of all buildings that meet their criteria (structural stability, feasibility, adaptability, etc.) with the intention of inviting interested parties to propose conversions of the buildings into densified social housing. Going forward, the proposed focus is creation of social housing communities within existing buildings which may be retrofitted with sustainable technologies, green design strategies and principles, aiming for the finished buildings to achieve ‘Net-Zero/Positive’ status. A Net-Zero building, according to The Green Building Council of South Africa (GBCSA) is a building which manages to produce resources it needs to function, and reduces wastage, emissions and demand of these resources during its lifespan. The categories which GBCSA includes are carbon, water, waste and ecology, this may include material selection, construction methods, etc.

Keywords: adaptive reuse, conversion, net-zero, social housing, sustainable communities

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Authors: Emmanuel Iyamuremye

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Extreme rainfall events have caused significant damage to agriculture, ecology, and infrastructure, disruption of human activities, injury, and loss of life. They also have significant social, economic, and environmental consequences because they considerably damage urban as well as rural areas. Early detection of extreme maximum rainfall helps to implement strategies and measures, before they occur, hence mitigating the consequences. Extreme value theory has been used widely in modeling extreme rainfall and in various disciplines, such as financial markets, the insurance industry, failure cases. Climatic extremes have been analyzed by using either generalized extreme value (GEV) or generalized Pareto (GP) distributions, which provides evidence of the importance of modeling extreme rainfall from different regions of the world. In this paper, we focused on Peak Over Thresholds approach, where the Poisson-generalized Pareto distribution is considered as the proper distribution for the study of the exceedances. This research also considers the use of the generalized Pareto (GP) distribution with a Poisson model for arrivals to describe peaks over a threshold. The research used statistical techniques to fit models that used to predict extreme rainfall in Kigali. The results indicate that the proposed Poisson-GP distribution provides a better fit to maximum monthly rainfall data. Further, the Poisson-GP models are able to estimate various return levels. The research also found a slow increase in return levels for maximum monthly rainfall for higher return periods, and further, the intervals are increasingly wider as the return period is increasing.

Keywords: exceedances, extreme value theory, generalized Pareto distribution, Poisson generalized Pareto distribution

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Authors: I. Boroňová, J.Bernasovská, J. Kľoc, Z. Tomková, E. Petrejčíková, D. Gabriková, S. Mačeková

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Osteoporosis is a complex health disease characterized by low bone mineral density, which is determined by an interaction of genetics with metabolic and environmental factors. Current research in genetics of osteoporosis is focused on identification of responsible genes and polymorphisms. TNFRSF11B gene plays a key role in bone remodeling. The aim of this study was to investigate the genotype and allele distribution of A163G (rs3102735) osteoprotegerin gene promoter and G1181C (rs2073618) osteoprotegerin first exon polymorphisms in the group of 180 unrelated postmenopausal women with diagnosed osteoporosis and 180 normal controls. Genomic DNA was isolated from peripheral blood leukocytes using standard methodology. Genotyping for presence of different polymorphisms was performed using the Custom Taqman®SNP Genotyping assays. Hardy-Weinberg equilibrium was tested for each SNP in the groups of participants using the chi-square (χ2) test. The distribution of investigated genotypes in the group of patients with osteoporosis were as follows: AA (66.7%), AG (32.2%), GG (1.1%) for A163G polymorphism; GG (19.4%), CG (44.4%), CC (36.1%) for G1181C polymorphism. The distribution of genotypes in normal controls were follows: AA (71.1%), AG (26.1%), GG (2.8%) for A163G polymorphism; GG (22.2%), CG (48.9%), CC (28.9%) for G1181C polymorphism. In A163G polymorphism the variant G allele was more common among patients with osteoporosis: 17.2% versus 15.8% in normal controls. Also, in G1181C polymorphism the phenomenon of more frequent occurrence of C allele in the group of patients with osteoporosis was observed (58.3% versus 53.3%). Genotype and allele distributions showed no significant differences (A163G: χ2=0.270, p=0.605; χ2=0.250, p=0.616; G1181C: χ2= 1.730, p=0.188; χ2=1.820, p=0.177). Our results represents an initial study, further studies of more numerous file and associations studies will be carried out. Knowing the distribution of genotypes is important for assessing the impact of these polymorphisms on various parameters associated with osteoporosis. Screening for identification of “at-risk” women likely to develop osteoporosis and initiating subsequent early intervention appears to be most effective strategy to substantially reduce the risks of osteoporosis.

Keywords: osteoporosis, real-time PCR method, SNP polymorphisms

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Authors: Ki-seok Kwon, Dong-woo Ryu, Heung-Youl Kim

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Although high-strength concrete has many advantages over generic concrete at normal temperatures (around 20℃), it undergoes spalling at high temperatures, which constitutes its structurally fatal drawback. In this study, fire resistance tests were conducted for 3 hours in accordance with ASTM E119 on bearing wall specimens which were 3,000mm x 3,000mm x 300mm in dimensions to investigate the influence the type of admixtures would exert on the fire resistance performance of high-strength concrete. Portland cement, blast furnace slag, fly ash and silica fume were used as admixtures, among which 2 or 3 components were combined to make 7 types of mixtures. In 56MPa specimens, the severity of spalling was in order of SF5 > F25 > S65SF5 > S50. Specimen S50 where an admixture consisting of 2 components was added did not undergo spalling. In 70MPa specimens, the severity of spalling was in order of SF5 > F25SF5 > S45SF5 and the result was similar to that observed in 56MPa specimens. Acknowledgements— This study was conducted by the support of the project, “Development of performance-based fire safety design of the building and improvement of fire safety” (18AUDP-B100356-04) which is under the management of Korea Agency for Infrastructure Technology Advancement as part of the urban architecture research project for the Ministry of Land, Infrastructure and Transport, for which we extend our deep thanks.

Keywords: high strength concrete, mineral admixture, fire resistance, social disaster

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Authors: Shiva Kumar G.

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The present study is to know the level of noises emanated from vehicles in intersections located in urban areas using Sound Level Meter and the possibility of reducing noise levels through traffic flow optimization. The main objective is to study traffic noise level of the Intersections located at on-going metro construction activities and which are away from metro construction activities. To compare traffic noise level between stop phase, go phase and drive phase at the Intersections. To study the effect of traffic noise level of directional movement of traffic and variation in noise level during day and night times. The range of Noise level observed at intersections is between 60 to 105 decibel. The noise level of stop and drive phases were minimum and almost same where go phase had maximum noise level. By comparing noise level of directional movement of traffic, it has been noticed that Vijayanagar intersection has no significant difference in their noise level and all other intersection has a significant difference in their noise level. By comparing noise level of stop, go and drive phase it has been noticed that there was a significant difference in noise level during peak hours compared to off-peak hour. By comparing noise level between Metro and Non-Metro construction activity intersections it has been noticed that there was a significant difference in noise level. By comparing noise level during day and night times, significant differences in noise level were observed at all intersections.

Keywords: noise, metro and non-metro intersections, traffic flow optimization, stop-go and drive phase

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Authors: Concetta Busacca, Leone Frusteri, Orazio Di Blasi, Alessandra Di Blasi

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The large-scale extension of renewable energy led, recently, to the development of efficient and low-cost electrochemical energy storage (EES) systems such as batteries. Although lithium-ion battery (LIB) technology is relatively mature, several issues regarding safety, cyclability, and high costs must be overcome. Thanks to the availability and low cost of sodium, sodium-ion batteries (NIB) have the potential to meet the energy storage needs of the large-scale grid, becoming a valid alternative to LIB in some energy sectors, such as the stationary one. However, important challenges such as low specific energy and short cyclic life due to the large radius of Na+ must be faced to introduce this technology into the market. As an important component of SIBs, cathode materials have a significant effect on the electrochemical performance of SIBs. Recently, sodium layer transition metal oxides, phosphates, and organic compounds have been investigated as cathode materials for SIBs. In particular, phosphate-based compounds such as NaₓMPO₄ (M= Fe, Co, Mn) have been extensively studied as cathodic polyanion materials due to their long cycle stability and appropriate operating voltage. Among these, an interesting cathode material is the NaMnPO₄ based one, thanks to the stability and the high redox potential of the Mn²⁺/Mn³⁺ ion pair (3÷4 V vs. Na+/Na), which allows reaching a high energy density. This work concerns with the synthesis of a composite material based on NaMnPO₄ and carbon nanofibers (NaMnPO₄-CNF) characterized by a mixed crystalline structure between the maricite and olivine phases and a self-standing manufacture obtained by electrospinning technique. The material was tested in a Na-ion battery coin cell in half cell configuration, and showed outstanding electrocatalytic performances with a specific discharge capacity of 125 mAhg⁻¹ and 101 mAhg⁻¹ at 0.3C and 0.6C, respectively, and a retention capacity of about 80% a 0.6C after 100 cycles.

Keywords: electrospinning, self standing materials, Na ion battery, cathode materials

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Authors: Mohammad Alkhatatbeh, Nehad Ayoub, Nizar Mhaidat, Nesreen Saadeh, Lisa Lincz

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CD36 is involved in the development of atherosclerosis by enhancing macrophage endocytosis of oxidized-low density lipoproteins and foam cell formation. Soluble CD36 (sCD36) was found to be elevated in type 2 diabetic patients and was supposed to act as a marker of insulin resistance and atherosclerosis. In young subjects, sCD36 was associated with cardiovascular risk factors including obesity and hypertriglyceridemia. This study was conducted to further investigate the relationship between plasma sCD36 and cardiovascular risk factors among middle-aged patients with metabolic syndrome (MetS) and healthy controls. SCD36 concentrations were determined by enzyme-linked immunosorbent assays (ELISA) for 41 patients with MetS and 36 healthy controls. Data for other variables were obtained from patients' medical records. SCD36 concentrations were relatively low compared to most other studies and were not significantly different between the MetS group and controls (P-value=0.17). SCD36 was also not correlated with age, body mass index, glucose, lipid profile, serum electrolytes and blood counts. SCD36 was not significantly different between subjects with obesity, hyperglycemia, dyslipidemia, hypertension or cardiovascular disease and those without these abnormalities (P-value > 0.05). The inconsistency between results reported in this study and other studies may be unique to the study population or be a result of the lack of a reliable standardized method for determining absolute sCD36 concentrations. However, further investigations are required to assess CD36 tissue expression in the study population and to assess the accuracy of various commercially available sCD36 ELISA kits. Thus, the availability of a standardized simple sCD36 ELISA that could be performed in any basic laboratory would be more favorable to the specialized flow cytometry methods that detect CD36+ microparticles if it was to be used as a biomarker.

Keywords: metabolic syndrome, CD36, cardiovascular risk, obesity, type 2 diabetes mellitus

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Authors: Tahani Amutairi, Paul May, Neil Allan

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Many properties of semiconductor materials (mechanical, electronic, magnetic, and optical) can be significantly modified by introducing a point defect. Diamond offers extraordinary properties as a semiconductor, and doping seems to be a viable method of solving the problem associated with the fabrication of diamond-based electronic devices in order to exploit those properties. The dopants are believed to play a significant role in reducing the energy barrier to conduction and controlling the mobility of the carriers and the resistivity of the film. Although it has been proven that the n-type diamond semiconductor can be obtained with phosphorus doping, the resulting ionisation energy and mobility are still inadequate for practical application. Theoretical studies have revealed that this is partly because the effects of the many phosphorus atoms incorporated in the diamond lattice are compensated by acceptor states. Using spin-polarised hybrid density functional theory and a supercell approach, we explored the effects of bonding one N atom to a P in adjacent substitutional sites in diamond. A range of hybrid functional, including HSE06, B3LYP, PBE0, PBEsol0, and PBE0-13, were used to calculate the formation, binding, and ionisation energies, in order to explore the solubility and stability of the point defect. The equilibrium geometry and the magnetic and electronic structures were analysed and presented in detail. The defect introduces a unique reconstruction in a diamond where one of the C atoms coordinated with the N atom involved in the elongated C-N bond and creates a new bond with the P atom. The simulated infrared spectra of phosphorus-nitrogen defects were investigated with different supercell sizes and found to contain two sharp peaks at the edges of the spectrum, one at a high frequency 1,379 cm⁻¹ and the second appearing at the end range, 234 cm⁻¹, as obtained with the largest supercell (216).

Keywords: DFT, HSE06, B3LYP, PBE0, PBEsol0, PBE0-13

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Authors: Villiam Ambong, Kevin Banawag, Wynne Shane Bugatan, Mark Alvin Jay Carpio, Hwan Hee Choi, Moises Kevin Chungalao

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This survey research investigated the perception of primary school teachers on the efficacy of MTB-MLE in SLU-LES, Baguio City. SLU-LES has a total of 21 primary school teachers who served as respondents of this study in an attempt to answer the major questions regarding the efficacy of MTB-MLE among primary school teachers. A questionnaire was used in collecting the data which were analyzed using weighted mean and ANOVA. The questionnaire was validated by a statistician and it was administered to a school which does not differ from the intended respondents for further validation of the items. Findings revealed from the intended respondents that they perceive MTB-MLE as effective; however, they do not prefer the use of Mother Tongue as a medium of instruction. A research on the same topic was conducted in Ibadan, Nigeria by Dr. David O. Fakeye and although his respondents were students; the results came out that the respondents do perceive MTB-MLE to be efficacious. The results of this study also showed that years of teaching experience and the number of languages spoken by the teachers have no bearing on the preference of the respondents between MT medium and English medium gave that the respondents are in melting pot community. Comparative studies between rural and urban schools are encouraged. Future researchers should include questions that elicit reasons of the respondents on the efficacy of mother tongue as well as their preference between mother tongue medium and English.

Keywords: mother tongue, primary teachers, perception, multilingual education

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Authors: Jayotpaul Chaudhuri, Lutz Goedeke, Torsten Hallenga, Peter Ehrhard

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Purification of gases from aerosols or airborne particles via filters is widely applied in the industry and in our daily lives. This separation especially in the micron and submicron size range is a necessary step to protect the environment and human health. Fibrous filters are often employed due to their low cost and high efficiency. For designing any filter the two most important performance parameters are capture efficiency and pressure drop. Since the capture efficiency is directly proportional to the pressure drop which leads to higher operating costs, a detailed investigation of the separation mechanism is required to optimize the filter designing, i.e., to have a high capture efficiency with a lower pressure drop. Therefore a two-dimensional flow simulation around a single fiber using Ansys CFX and Matlab is used to get insight into the separation process. Instead of simulating a solid fiber, the present Ansys CFX model uses a fictitious domain approach for the fiber by implementing a momentum loss model. This approach has been chosen to avoid creating a new mesh for different fiber sizes, thereby saving time and effort for re-meshing. In a first step, only the flow of the continuous fluid around the fiber is simulated in Ansys CFX and the flow field data is extracted and imported into Matlab and the particle trajectory is calculated in a Matlab routine. This calculation is a Lagrangian, one way coupled approach for particles with all relevant forces acting on it. The key parameters for the simulation in both Ansys CFX and Matlab are the porosity ε, the diameter ratio of particle and fiber D, the fluid Reynolds number Re, the Reynolds particle number Rep, the Stokes number St, the Froude number Fr and the density ratio of fluid and particle ρf/ρp. The simulation results were then compared to the single fiber theory from the literature.

Keywords: BBO-equation, capture efficiency, CFX, Matlab, fibrous filter, particle trajectory

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Authors: Ismail Kurt, Necibe Fusun Oyman Serteller

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Today, with the reduction in semiconductor system costs, Brushless Direct Current (BLDC) motors have become widely preferred. Based on rotor architecture, BLDC structures are divided into internal permanent magnet (IPM) and surface permanent magnet (SPM). However, permanent magnet (PM) motors in electric vehicles (EVs) are still predominantly based on interior permanent magnet (IPM) motors, as the rotors do not require sleeves, the PMs are better protected by the rotor cores, and the air-gap lengths can be much smaller. This study discusses the IPM rotor structure in detail, highlighting its higher torque levels, reluctance torque, wide speed range operation, and production advantages. IPM rotor structures are particularly preferred in EVs due to their high-speed capabilities, torque density and field weakening (FW) features. In FW applications, the motor becomes more suitable for operation at torques lower than the rated torque but at speeds above the rated speed. Although V-type and triangular IPM rotor structures are generally preferred in EV applications, the spoke-type rotor structure offers distinct advantages, making it a competitive option for these systems. The flux barriers in the rotor significantly affect motor performance, providing notable benefits in both motor efficiency and cost. This study utilizes ANSYS/Maxwell simulation software to analyze the spoke-type IPM motor and examine its key design parameters. Through analytical and 2D analysis, preliminary motor design and parameter optimization have been carried out. During the parameter optimization phase, torque ripple a common issue, especially for IPM motors has been investigated, along with the associated changes in motor parameters.

Keywords: electric vehicle, field weakening, flux barrier, spoke rotor.

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Authors: Sharareh Hekmat, Michelle Lane

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Pregnancy during adolescence affects both the growth and development of mother and baby, particularly in low socioeconomic and food insecure areas. This mixed methods study is aimed at discovering a need for a community-based probiotic yogurt program to assist pregnant women in the Mukuru slum Nairobi, Kenya. Surveys were conducted with pregnant women (14-25 years old, n=43), which included questionnaires on dietary intake, food access, and health/quality of life perception. The frequency and means procedure was used to analyze maternal characteristics, Women’s Dietary Diversity Score (WDDS) and Household Hunger Scale. 24-hour recalls were analyzed via ESHA Food Processor, and median nutrient intakes were reported as a percent of recommendations. An environmental scan was conducted to assess food availability, accessibility, and quality. WDDS reflected a low-moderate diet variation (3.86 food groups out of 9, SD ± 1.3) among the women. The 24-hour recall suggested an inadequate intake of many nutrients, most significantly B12, potassium and calcium. 86% of women reported little to no household hunger. However, the environmental scan revealed low quality and poor sanitation of food. This study provides evidence that a probiotic program would be desirable, and contribute to the nutritional status of women in the Mukuru community.

Keywords: dietary diversity, pregnant women, probiotics, urban slum, Kenya

Procedia PDF Downloads 194

Authors: Xue Wu

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Since the 1980s, a series of policies and practices have been implemented in China in response to the unprecedented rate of ageing population. The paper provides a detailed narrative of what later-life learning policy discourses have been advocated and gives a description on relevant practical issues during the past three decades. The research process based on the discourse approach with a systematic review of the government-issued documents. It finds that the main practices taken by central government at various levels were making University of the Aged (UA) available in all urban and rural regions to consolidate the newly student enrollments; focusing social-recreational, leisure and cultural activities on 55-75 age group; and utilizing various methods including voluntary works and tourism to improve older adults’ physical and mental wellness. Although there were greater achievements with 30 years of development, many problems still exist. Finding reveals that the curriculum should be modified to meet the needs of the local development, to promote older adults’ contact and contribution to the community, and to enhance technical competences of those in rural areas involving in agricultural production. Central government should also integrate resources from all sectors of the society for further developing later-life learning in China. The result of this paper highlights the value to promote community-based later-life learning for building a society for active ageing and ageing in place.

Keywords: ageing population, China, later-life learning, policy, University of the Aged

Procedia PDF Downloads 148

Authors: Pham Minh Duc, Tran Thi Thanh Hien, David A. Bengtson

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Laboratory feeding trial: the study was conducted to find out the optimal dietary vitamin C, or ascorbic acid (AA) levels in terms of the growth performance of snakehead. The growth trial included six treatments with five replications. Each treatment contained 0, 125, 250, 500, 1000 and 2000 mg AA equivalent kg⁻¹ diet which included six iso-nitrogenous (45% protein), iso-lipid (9% lipid) and isocaloric (4.2 Kcal.g¹). Eighty snakehead fingerlings (6.24 ± 0.17 g.fish¹) were assigned randomly in 0.5 m³ composite tanks. Fish were fed twice daily on demand for 8 weeks. The result showed that growth rates increased, protein efficiency ratio increased and the feed conversion ratio decreased in treatments with AA supplementation compared with control treatment. The survival rate of fish tends to increase with increase AA level. The number of RBCs, lysozyme in treatments with AA supplementation tended to rise significantly proportional to the concentration of AA. The number of WBCs of snakehead in treatments with AA supplementation was higher 2.1-3.6 times. In general, supplementation of AA in the diets for snakehead improved growth rate, feed efficiency and immune response. Hapa on-farm trial: based on the results of the laboratory feeding trial, the effects of AA on snakehead in hapas to simulate farm conditions, was tested using the following treatments: commercial feed; commercial feed plus hand mixed AA at 500; 750 and 1000 mg AA.kg⁻¹; SBM diet without AA; SBM diet plus 500; 750 and 1000 mg AA.kg⁻¹. The experiment was conducted in two experimental ponds (only SBM diet without AA placed in one pond and the rest in the other pond) with four replicate hapa each. Stocking density was 150 fish.m² and culture period was 5 months until market size was attained. The growth performance of snakehead and economic aspects were examined in this research.

Keywords: fish health, growth rate, snakehead, Vitamin C

Procedia PDF Downloads 110

Authors: Villiam C. Ambong, Kevin G. Banawag, Wynne Shane B. Bugatan, Mark Alvin Jay R. Carpio, Hwan Hee Choi, Moses Kevin L. Chungalao

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This survey research investigated the perception of primary school teachers on the efficacy of MTB-MLE in SLU-LES, Baguio City. SLU-LES has a total of 21 primary school teachers who served as the respondents of this study in an attempt to answer three major questions regarding the efficacy of MTB-MLE among primary school teachers. A questionnaire was used in collecting the data which were analyzed using weighted mean and ANOVA. The questionnaire was validated by a statistician and it was administered to a school which does not differ from the intended respondents for further validation of the items. Findings revealed from the intended respondents that they perceive MTB-MLE as effective; however, they do not prefer the use of Mother Tongue as medium of instruction. A research of the same topic was conducted in Ibadan, Nigeria by Dr. David O. Fakeye and although his respondents were students; the results came out that the respondents do perceive MTB-MLE to be efficacious. The results of this study also showed that years of teaching experience and number of languages spoken by the teachers have no bearing on the preference of the respondents between MT medium and English medium given that the respondents are in a melting pot community. Comparative studies between rural schools and urban schools are encouraged. Future researches should include questions that elicit reasons of the respondents on the efficacy of mother tongue as well as their preference between mother tongue medium and English.

Keywords: mother tongue, primary teachers, perception, multilingual education

Procedia PDF Downloads 459

Authors: Pradeep Raj Sharma, Bogeun Jang, Jongill Hong

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Spin-orbit torque (SOT) is an efficient approach for manipulating the magnetization of ferromagnetic materials (FMs), providing improved device performance, better compatibility, and ultra-fast switching with lower power consumption compared to spin-transfer torque (STT). Among the various materials and structural designs, two-dimensional (2D) van-der Waals (vdW) layered materials and their heterostructures have been demonstrated as highly scalable and promising device architecture for SOT. In particular, a bilayer heterostructure consisting of fully 2D-vdW-FM, non-magnetic material (NM) offers a potential platform for controlling the magnetization using SOT because of the advantages of being easy to scale and less energy to switch. Here, we report filed-free deterministic switching driven by SOT at room temperature, integrating perpendicularly magnetized 2D-vdW material Fe₃GaTe₂ (FGaT) and NM WTe₂. Pulse current-induced magnetization switching with an ultra-low current density of about 6.5×10⁵ A/cm², yielding a SOT efficiency close to double-digits at 300 K, is reported. These values are two orders of magnitude higher than those observed in conventional heavy metal (HM) based SOT and exceed those reported with 2D-vdW layered materials. WTe₂, a topological semimetal possessing strong SOC and high spin Hall angle, can induce significant spin accumulation with negligible spin loss across the transparent 2D bilayer heterointerface. This promising device architecture enables highly compatible, energy-efficient, non-volatile memory and lays the foundation for designing efficient, flexible, and miniaturized spintronic devices.

Keywords: spintronics, spin-orbit torque, spin Hall effect, spin Hall angle, topological semimetal, perpendicular magnetic anisotropy

Procedia PDF Downloads 19

Authors: O. Alelweet, S. Pavia

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In order to face current compelling environmental problems affecting the planet, the construction industry needs to adapt. It is widely acknowledged that there is a need for durable, high-performance, low-greenhouse gas emission binders that can be used as an alternative to Portland cement (PC) to lower the environmental impact of construction. Alkali activated materials (AAMs) are considered a more sustainable alternative to PC materials. The binders of AAMs result from the reaction of an alkali metal source and a silicate powder or precursor which can be a calcium silicate or an aluminosilicate-rich material. This paper evaluates the particle size, specific surface area, chemical and mineral composition and amorphousness of silicate materials (most industrial waste locally produced in Ireland and Saudi Arabia) to develop alkali-activated binders that can replace PC resources in specific applications. These include recycled ceramic brick, bauxite, illitic clay, fly ash and metallurgical slag. According to the results, the wastes are reactive and comply with building standards requirements. The study also evidenced that the reactivity of the Saudi bauxite (with significant kaolinite) can be enhanced on thermal activation; and high calcium in the slag will promote reaction; which should be possible with low alkalinity activators. The wastes evidenced variable water demands that will be taken into account for mixing with the activators. Finally, further research is proposed to further determine the reactive fraction of the clay-based precursors.

Keywords: alkali activated materials, alkali-activated binders, sustainable building materials, recycled ceramic brick, bauxite, red mud, clay, fly ash, metallurgical slags, particle size, chemical and mineral composition and amorphousness, water demand, particle density

Procedia PDF Downloads 128

Authors: Himanshu Singh, Rishi Kant, Shantanu Bhattacharya

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This paper adopts a top-down approach for mathematical modeling to predict the size reduction from micro to nano-scale through persistent etching. The process is simulated using a finite difference approach. Previously, various researchers have simulated the etching process for 1-D and 2-D substrates. It consists of two processes: 1) Convection-Diffusion in the etchant domain; 2) Chemical reaction at the surface of the particle. Since the process requires analysis along moving boundary, partial differential equations involved cannot be solved using conventional methods. In 1-D, this problem is very similar to Stefan's problem of moving ice-water boundary. A fixed grid method using finite volume method is very popular for modelling of etching on a one and two dimensional substrate. Other popular approaches include moving grid method and level set method. In this method, finite difference method was used to discretize the spherical diffusion equation. Due to symmetrical distribution of etchant, the angular terms in the equation can be neglected. Concentration is assumed to be constant at the outer boundary. At the particle boundary, the concentration of the etchant is assumed to be zero since the rate of reaction is much faster than rate of diffusion. The rate of reaction is proportional to the velocity of the moving boundary of the particle. Modelling of the above reaction was carried out using Matlab. The initial particle size was taken to be 50 microns. The density, molecular weight and diffusion coefficient of the substrate were taken as 2.1 gm/cm3, 60 and 10-5 cm2/s respectively. The etch-rate was found to decline initially and it gradually became constant at 0.02µ/s (1.2µ/min). The concentration profile was plotted along with space at different time intervals. Initially, a sudden drop is observed at the particle boundary due to high-etch rate. This change becomes more gradual with time due to declination of etch rate.

Keywords: particle size reduction, micromixer, FDM modelling, wet etching

Procedia PDF Downloads 434

Authors: Brenda R. Berca, Jessica S. Vieira, Lucas G. Candido, Matheus C. Ferreira, Paulo S. A. Lopes Filho, Rafaella O. Baracho

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This study aims to estimate the economic value environmental services sustained by Flamboyant Lourival Louza Municipal Park in Goiânia, Goiás, Brazil. The Flamboyant Park is one of the most relevant urban parks, and it is located near a stadium, a shopping center, and two supercenters. In order to define the methods used for the valuation of Flamboyant Park, the first step was carrying out bibliographical research with the view to better understand which method is most feasible to valuate the Park. Thus, the following direct methods were selected: travel cost, hedonic pricing, and contingent valuation. In addition, an indirect method (replacement cost) was applied at Flamboyant Park. The second step was creating and applying two surveys. The first survey aimed at the visitors of the park, addressing socio-economic issues, the use of the Park, as well as its importance and the willingness the visitors, had to pay for its existence. The second survey was destined to the existing trade in the Park, in order to collect data regarding the profits obtained by them. In the end, the characterization of the profile of the visitors and the application of the methods of contingent valuation, travel cost, replacement cost and hedonic pricing were obtained, thus monetarily valuing the various ecosystem services sustained by the park. Some services were not valued due to difficulties encountered during the process.

Keywords: contingent valuation, ecosystem services, economic environmental valuation, hedonic pricing, travel cost

Procedia PDF Downloads 231

Authors: Mergim Gasia, Bojan Milovanovica, Sanjin Gumbarevic

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Better energy performance of the building envelope is one of the most important aspects of energy savings if the goals set by the European Union are to be achieved in the future. Dynamic heat transfer simulations are being used for the calculation of building energy consumption because they give more realistic energy demands compared to the stationary calculations that do not take the building’s thermal mass into account. Software used for these dynamic simulation use methods that are based on the analytical models since numerical models are insufficient for longer periods. The analytical models used in this research fall in the category of the conduction transfer functions (CTFs). Two methods for calculating the CTFs covered by this research are the Laplace method and the State-Space method. The literature review showed that the main disadvantage of these methods is that they are inadequate for heavyweight façade elements and shorter time periods used for the calculation. The algorithms for both the Laplace and State-Space methods are implemented in Mathematica, and the results are compared to the results from EnergyPlus and TRNSYS since these software use similar algorithms for the calculation of the building’s energy demand. This research aims to check the efficiency of the Laplace and the State-Space method for calculating the building’s energy demand for heavyweight building elements and shorter sampling time, and it also gives the means for the improvement of the algorithms used by these methods. As the reference point for the boundary heat flux density, the finite difference method (FDM) is used. Even though the dynamic heat transfer simulations are superior to the calculation based on the stationary boundary conditions, they have their limitations and will give unsatisfactory results if not properly used.

Keywords: Laplace method, state-space method, conduction transfer functions, finite difference method

Procedia PDF Downloads 136

Authors: Camilo A. Guerrero-Martin, Erik Montes Paez, Marcia C. K. Oliveira, Jonathan Campos, Elizabete F. Lucas

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Asphaltenes precipitation is considered as a formation damage problem, which can reduce the oil recovery factor. It fouls piping and surface installations, as well as cause serious flow assurance complications and decline oil well production. Therefore, researchers have shown an interest in chemical treatments to control this phenomenon. The aim of this paper is to assess the asphaltenes precipitation onset of crude oils in the presence of cardanol, by titrating the crude with n-heptane. Moreover, based on this results obtained at atmosphere pressure, the asphaltenes precipitation onset pressure were calculated to predict asphaltenes precipitation in the reservoir, by using differential liberation and refractive index data of the oils. The influence of cardanol concentrations in the asphaltenes stabilization of three Brazilian crude oils samples (with similar API densities) was studied. Therefore, four formulations of cardanol in toluene were prepared: 0, 3, 5, 10 and 15 m/m%. The formulations were added to the crude at 2:98 ratio. The petroleum samples were characterized by API density, elemental analysis and differential liberation test. The asphaltenes precipitation onset (APO) was determined by titrating with n-heptane and monitoring with near-infrared (NIR). UV-Vis spectroscopy experiments were also done to assess the precipitate asphaltenes content. The asphaltenes precipitation envelopes (APE) were also determined by numerical simulation (Multiflash). In addition, the adequate artificial lift systems (ALS) for the oils were selected. It was based on the downhole well profile and a screening methodology. Finally, the oil flowrates were modelling by NODAL analysis production system in the PIPESIM software. The results of this study show that the asphaltenes precipitation onset of the crude oils were 2.2, 2.3 and 6.0 mL of n-heptane/g of oil. The cardanol was an effective inhibitor of asphaltenes precipitation for the crude oils used in this study, since it displaces the precipitation pressure of the oil to lower values. This indicates that cardanol can increase the oil wells productivity.

Keywords: asphaltenes, NODAL analysis production system, precipitation pressure onset, inhibitory molecule

Procedia PDF Downloads 178