Search results for: distribution channel

Authors: Srikanth Pandurangi, Basheer Mohammed, Nezar Al Sayegh

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In order to meet the increasing demand for housing care for Kuwaiti citizens, the government authorities in Kuwait are undertaking a series of projects in the form of new large cities, outside the current urban area. Al Mutlaa City located to the north-west of the Kuwait Metropolitan Area is one such project out of the 15 planned new cities. The city accommodates a wide variety of residential developments, employment opportunities, commercial, recreational, health care and institutional uses. This paper examines the application of comprehensive transportation demand modeling works undertaken in VISUM platform to understand the future intracity and intercity travel distribution patterns in Kuwait. The scope of models developed varied in levels of detail: strategic model update, sub-area models representing future demand of Al Mutlaa City, sub-area models built to estimate the demand in the residential neighborhoods of the city. This paper aims at offering model update framework that facilitates easy integration between sub-area models and strategic national models for unified traffic forecasts. This paper presents the transportation demand modeling results utilized in informing the planning of multi-modal transportation system for Al Mutlaa City. This paper also presents the household survey data collection efforts undertaken using GPS devices (first time in Kuwait) and notebook computer based digital survey forms for interviewing representative sample of citizens and residents. The survey results formed the basis of estimating trip generation rates and trip distribution coefficients used in the strategic base year model calibration and validation process.

Keywords: innovative methods in transportation data collection, integrated public transportation system, traffic forecasts, transportation modeling, travel behavior

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Authors: Vladimir S. Timofeev

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In this article the problem of distributional moments estimation is considered. The new approach of moments estimation based on usage of the characteristic function is proposed. By statistical simulation technique, author shows that new approach has some robust properties. For calculation of the derivatives of characteristic function there is used numerical differentiation. Obtained results confirmed that author’s idea has a certain working efficiency and it can be recommended for any statistical applications.

Keywords: characteristic function, distributional moments, robustness, outlier, statistical estimation problem, statistical simulation

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Authors: Jma Hannan, Prawej Ansari, Yasser H. A. Abdel-Wahab, Peter R. Flatt

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Spirulina platensis (SP, Blue-green algae) have been accepted as a supplement for the treatment of pre and post-diabetes. The present study investigated the effects of butanol fraction from ethanol extract of S. platensis on insulin release from BRIN BD11 cells, isolated mouse islets, and perfused rat pancreas, as well as glucose homeostasis in type 2 diabetic rats and their molecular pathways. In a dose-dependent manner, S. platensis increased insulin release from mouse islets and pancreatic β-cells. The extract also elevated insulin release in perfused rat pancreas. Glucose, isobutylmethylxanthine, tolbutamide, and a depolarizing concentration of KCl significantly potentiated insulin release from BRIN BD11 cells. The effect of diazoxide and verapamil, as well as the absence of extracellular Ca2+ showed a reduction in insulin secretion. When administered orally together with glucose (2.5g/kg bw), S. platensis extract improved fasting and postprandial blood glucose in type 2 diabetes. These data suggest that the anti-diabetic activity of S. platensis is partly mediated by insulin secretion via the KATP channel-dependent pathway/the intracellular cAMP pathway.

Keywords: Insulin, glucose, S. platensis, type 2 diabetes, medicinal plants

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Authors: Virendra J. Majarikar, Harikrishnan N. Unni

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This paper sets to demonstrate a modeling of electrokinetic mixing employing electroosmotic stationary and time-dependent microchannel using alternate zeta patches on the lower surface of the micromixer in a lab on chip microfluidic device. Electroosmotic flow is amplified using different 2D and 3D model designs with alternate and geometric zeta potential values such as 25, 50, and 100 mV, respectively, to achieve high concentration mixing in the electrokinetically-driven microfluidic system. The enhancement of electrokinetic mixing is studied using Finite Element Modeling, and simulation workflow is accomplished with defined integral steps. It can be observed that the presence of alternate zeta patches can help inducing microvortex flows inside the channel, which in turn can improve mixing efficiency. Fluid flow and concentration fields are simulated by solving Navier-Stokes equation (implying Helmholtz-Smoluchowski slip velocity boundary condition) and Convection-Diffusion equation. The effect of the magnitude of zeta potential, the number of alternate zeta patches, etc. are analysed thoroughly. 2D simulation reveals that there is a cumulative increase in concentration mixing, whereas 3D simulation differs slightly with low zeta potential as that of the 2D model within the T-shaped micromixer for concentration 1 mol/m³ and 0 mol/m³, respectively. Moreover, 2D model results were compared with those of 3D to indicate the importance of the 3D model in a microfluidic design process.

Keywords: COMSOL Multiphysics®, electrokinetic, electroosmotic, microfluidics, zeta potential

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Authors: Arifin Matoka, Nadjamuddin Harun, Salama Manjang, M. Arsyad Thaha

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Along irrigation canals in certain areas falling water level height is have potential for micro hydro power plant (MHP), which generally MHP potential valley away from society consumer of electricity and needed a long conductor cable, so that with the MHP Irrigation is ideal are typical with an Open Flume type turbines. This study is divided into two phases research phase of the potential power that exist in irrigation channels at the Gorontalo Province and stages solution sedimentation effects. The total power generated in the irrigation channel of the results of this study at 781.83 Kw, it is quite significant for the 1737 rural households on average consumes 450 watt per household. In the field of observation, sedimentation lifting effect on the quality of electric power, at which time the turbid sediment concentrations occur significant voltage fluctuations causing damage to some household electrical appliances such as electronic equipment and lighting. This problem is solution by modeling the sedimentation tub (setling basin) to reduce sedimentation thus olso can reduce the regulation load control equipment which can minimize the cost of investment and maintenance.

Keywords: irrigation canals, microhydro powerplant, sedimentation, Gorontalo Province

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Authors: V. Surena, B. Nazemisalman, F. Noghrehkar

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Introduction: Gingival overgrowth (GO) is a common side effect involving users of antiepileptic, immunosuppressive and calcium channel blocker drugs. Cyclosporine and phenytoin are amongst the most widely used drugs associated with GO. Gingival fibroblasts seem to have a significant role in the production of certain enzymes after administration of the drugs contributing to GO. Previous studies have shown a higher prevalence of GO in children and adolescents. The aim of this study was to compare normal human gingival fibroblasts with those exposed to Cyclosporine or phenytoin in measuring the production levels of certain enzymes that could have a possible role in GO. Methods: samples were obtained from the gingival biopsies of seven adult and seven children and were cultured into plates. With the growth of fibroblast cells, they were treated with or without either Cyclosporine or phenytoin. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to determine the expressed levels of R-EGF, cathepsin B,L, Lysyl oxidase, COL1, TGF β1, MMP-1,2, and TIMP1. Results: according to RT-PCR analyses, the expressed levels of R-EGF, cathepsin B, L, Lysyl oxidase, COL1, TGF β1, MMP-1, 2 and TIMP1 were affected by Cyclosporine and phenytoin. TGF-β1, TIMP, Cathepsin B and EGF showed comparable values in the adult and pediatric groups. Conclusions: Different expressed levels of enzymes after treatment of the gingival fibroblasts of adults and pediatrics with phenytoin or Cyclosporine could be the reason for the higher severity of GO in children. More studies need to be performed on the pathogenesis of GO at different age groups.

Keywords: cyclosporine, fibroblasts, phenytoin, gingivae

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Authors: Mohammed Mainoma, Abubakar Tijanni, Mohammed Aliyu

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Globalization has brought a structural change in industry. It is the breaking of artificial boundaries and given way to new product, new service, new market, and new technology among others. It leads to the realization that men entrepreneurs’ alone cannot meet the demand of the teeming population. Therefore there is a need for the participation, involvement, and engagement of females in the production and distribution of goods and services. This will enhance growth and development of a nation. It is in line with the above that this paper attempt to discuss meaning of women entrepreneurs, roles, types, problems, and prospects. Also, on the basis of conclusion the paper recommended that entrepreneurship education should be introduced in all Tertiary Institutions in Nigeria.

Keywords: women, entrepreneurs, issues, challenges

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Authors: Zina Ghiloufi, Tahar Khir

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A transient three-dimensional computational fluid dynamics (CFD) model is developed to determine the velocity and temperature distribution in different positions cold room during pre-cooling of dates. The turbulence model used is the k-ω Shear Stress Transport (SST) with the standard wall function, the air. The numerical results obtained show that cooling rate is not uniform inside the room; the product at the medium of room has a slower cooling rate. This cooling heterogeneity has a large effect on the energy consumption during cold storage.

Keywords: CFD, cold room, cooling rate, dDates, numerical simulation, k-ω (SST)

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Authors: A. O. Idris, J. Virgone, A. I. Ibrahim, D. David, E. Vergnault

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In hot countries, the major challenge is the air conditioning. The increase in energy consumption by air conditioning stems from the need to live in more comfortable buildings, which is understandable. But in Djibouti, one of the countries with the most expensive electricity in the world, this need is exacerbated by an architecture that is inappropriate and unsuitable for climatic conditions. This paper discusses the design of the roof which is the surface receiving the most solar radiation. The roof determines the general behavior of the building. The study presents Computational Fluid Dynamics (CFD) modeling and analysis of the energy performance of a double skin ventilated roof. The particularity of this study is that it considers the climate of Djibouti characterized by hot and humid conditions in winter and very hot and humid in summer. Roof simulations are carried out using the Ansys Fluent software to characterize the flow and the heat transfer induced in the ventilated roof in steady state. This modeling is carried out by comparing the influence of several parameters such as the internal emissivity of the upper surface, the thickness of the insulation of the roof and the thickness of the ventilated channel on heat gain through the roof. The energy saving potential compared to the current construction in Djibouti is also presented.

Keywords: building, double skin roof, CFD, thermo-fluid analysis, energy saving, forced convection, natural convection

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Authors: Pankaj Verma, Gagandeep Singh Walia, Padma Devi, H. P. Singh

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Code Division Multiple Access 2000 operates on various RF channel bandwidths 1.2288 or 3.6864 Mcps. CDMA offers high bandwidth and wireless broadband services but the efficiency gets decreased because of many interfering factors like fading, interference, scattering, diffraction, refraction, reflection etc. To reduce the spectral bandwidth is one of the major concerns in modern day technology and this is achieved by pulse shaping filter. This paper investigates the effect of diversity (MRC), interpolation factor in Root Raised Cosine (RRC) filter for the QPSK and BPSK modulation schemes. It is made possible to send information with minimum inter symbol interference and within limited bandwidth with proper pulse shaping technique. Bit error rate (BER) performance is analyzed by applying diversity technique by varying the interpolation factor for Binary Phase Shift Keying (BPSK) and Quadrature Phase Shift Keying (QPSK). Interpolation factor increases the original sampling rate of a sequence to a higher rate and reduces the interference and diversity reduces the fading.

Keywords: CDMA2000, root raised cosine, roll off factor, ISI, diversity, interference, fading

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Authors: Delaram Ghodsi, Nasrin Omidvar, Hassan Eini-Zinab, Arash Rashidian, Hossein Raghfar

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Food supplementary programs are policy approaches that aim to reduce financial barriers to healthy diets and tackle food insecurity. This study aimed to evaluate the effect of the supportive section of Multidisciplinary Supplementary Program for Improvement of Nutritional Status of Children (MuPINSC) on households’ food security status and nutritional status of mothers. MuPINSC is a national integrative program in Iran that distributes supplementary food basket to malnourished or growth retarded children living in low-income families in addition to providing health services, including sanitation, growth monitoring, and empowerment of families. This longitudinal study is part of a comprehensive evaluation of the program. The study participants included 359 mothers of children aged 6 to 72 month under coverage of the supportive section of the program in two provinces of Iran (Semnan and Qazvin). Demographic and economic characteristics of families were assessed by a questionnaire. Data on food security of family was collected by locally adapted Household Food Insecurity Access Scale (HFIAS) at the baseline of the study and six month thereafter. Weight and height of mothers were measured at the baseline and end of the study and mother’s BMI was calculated. Data were analysed, using paired t-test, GEE (Generalized Estimating Equation), and Chi-square tests. Based on the findings, at the baseline, only 4.7% of families were food-secure, while 13.1%, 38.7% and, 43.5% were categorized as mild, moderate and severe food insecure. After six months follow up, the distribution of different levels of food security changed significantly (P<0.001) to 7.9%, 11.6%, 42.6%, and 38%, respectively. At the end of the study, the chance of food insecurity was significantly 20% lower than the beginning (OR=0.796; 0.653-0.971). No significant difference was observed in maternal BMI based on food security (P>0.05). The findings show that the food supplementary program for children improved household food security status in the studied households. Further research is needed to assess other factors that affect the effectiveness of this large scale program on nutritional status and household’s food security.

Keywords: food security, food supplementary program, household, malnourished children

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Authors: Sheraz Gul

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The requirements for progressing a compound to clinical trials is well established and relies on the results from in-vitro and in-vivo animal tests to indicate that it is likely to be safe and efficacious when testing in humans. The typical data package required will include demonstrating compound safety, toxicity, bioavailability, pharmacodynamics (potential effects of the compound on body systems) and pharmacokinetics (how the compound is potentially absorbed, distributed, metabolised and eliminated after dosing in humans). If the desired criteria are met and the compound meets the clinical Candidate criteria and is deemed worthy of further development, a submission to regulatory bodies such as the US Food & Drug Administration for an exploratory Investigational New Drug Study can be made. The purpose of this study is to collect data to establish that the compound will not expose humans to unreasonable risks when used in limited, early-stage clinical studies in patients or normal volunteer subjects (Phase I). These studies are also designed to determine the metabolism and pharmacologic actions of the drug in humans, the side effects associated with increasing doses, and, if possible, to gain early evidence on their effectiveness. In order to reach the above goals, we have developed a pre-clinical high throughput Absorption, Distribution, Metabolism and Excretion–Toxicity (ADME–Toxicity) panel of assays to identify compounds that are likely to meet the Lead and Candidate compound acceptance criteria. This panel includes solubility studies in a range of biological fluids, cell viability studies in cancer and primary cell-lines, mitochondrial toxicity, off-target effects (across the kinase, protease, histone deacetylase, phosphodiesterase and GPCR protein families), CYP450 inhibition (5 different CYP450 enzymes), CYP450 induction, cardio-toxicity (hERG) and gene-toxicity. This panel of assays has been applied to multiple compound series developed in a number of projects delivering Lead and clinical Candidates and examples from these will be presented.

Keywords: absorption, distribution, metabolism and excretion–toxicity , drug discovery, food and drug administration , pharmacodynamics

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Authors: Sitti Rahmawati

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Payment system of cataract surgery implemented by professional attendant of doctor and nurse has been increasing, through health insurance program and this has become one of the factors that affects a lot of government in the budget establishment. This system has been implemented in purpose of quality and expenditure control, i.e., controlling health overpayment to obtain benefit (moral hazard) by the user of insurance or health service provider. The increasing health cost becomes the main issue that hampers the society to receive required health service in cash payment-system. One of the efforts that should be taken by the government in health payment is by securing health insurance through society's health insurance. The objective of the study is to learn the capability of a patient to pay cataract eye operation for the elders. Method of study sample population in this study was patients who obtain health insurance board card for the society that was started in the first of tri-semester (January-March) 2015 and claimed in Indonesian software-Case Based Group as a purposive sampling of 40 patients. Results of the study show that total unit cost analysis of surgery service unit was obtained $75 for unit cost without AFC and salary of nurse and doctor. The operation tariff that has been implemented today at Anutapura hospitals in eye department is tariff without AFC and the salary of the employee is $80. The operation tariff of the unit cost calculation with double distribution model at $65. Conclusion, the calculation result of actual unit cost that is much greater causes incentive distribution system provided to an ophthalmologist at $37 and nurse at $20 for one operation. The surgery service tariff is still low; consequently, the hospital receives low revenue and the quality of health insurance in eye operation department is relatively low. In purpose of increasing the service quality, it requires adequately high cost to equip medical equipment and increase the number of professional health attendant in serving patients in cataract eye operation at hospital.

Keywords: economic evaluation, cataract operation, health attendant, health insurance system

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Authors: Faisal A. Salih

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Verapamil hydrochloride (Ver) is a drug used in medicine for arrythmia, angina and hypertension as a calcium channel blocker. For the quantitative determination of Ver in dosage forms, the HPLC method is most often used. A convenient alternative to the chromatographic method is potentiometry using a Verselective electrode, which does not require expensive equipment, can be used without separation from the matrix components, which significantly reduces the analysis time, and does not use toxic organic solvents, being a "green", "environmentally friendly" technique. It has been established in this study that the rational choice of the membrane plasticizer and the preconditioning and measurement algorithms, which prevent nonexchangeable extraction of Ver into the membrane phase, makes it possible to achieve excellent analytical characteristics of Ver-selective electrodes based on commercially available components. In particular, an electrode with the following membrane composition: PVC (32.8 wt %), ortho-nitrophenyloctyl ether (66.6 wt %), and tetrakis-4-chlorophenylborate (0.6 wt % or 0.01 M) have the lower detection limit 4 × 10−8 M and potential reproducibility 0.15–0.22 mV. Both direct potentiometry (DP) and potentiometric titration (PT) methods can be used for the determination of Ver in tablets and injection solutions. Masses of Ver per average tablet weight determined by the methods of DP and PT for the same set of 10 tablets were (80.4±0.2 and80.7±0.2) mg, respectively. The masses of Ver in solutions for injection, determined by DP for two ampoules from one set, were (5.00±0.015 and 5.004±0.006) mg. In all cases, good reproducibility and excellent correspondence with the declared quantities were observed.

Keywords: verapamil, potentiometry, ion-selective electrode, pharmaceutical analysis

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Authors: Linda Smail, Zineb Azouz

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Given a Bayesian network relative to a set I of discrete random variables, we are interested in computing the probability distribution P(S) where S is a subset of I. The general idea is to write the expression of P(S) in the form of a product of factors where each factor is easy to compute. More importantly, it will be very useful to give an interpretation of each of the factors in terms of conditional probabilities. This paper considers a semantic interpretation of the factors involved in computing marginal probabilities in Bayesian networks. Establishing such a semantic interpretations is indeed interesting and relevant in the case of large Bayesian networks.

Keywords: Bayesian networks, D-Separation, level two Bayesian networks, factorization of computation

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Authors: Hessam Mortezaei, Saeid Joudakian

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In this paper, the wear problem on rider rings of boil off gas compressor has been studied. This kind of oil free double acting compressor has free floating piston (FFP) technology and as a result of that it should have the lowest possible wear on its rider rings. But a design problem had caused a complete wear of rider rings after one month of continuous operation. In this case study, the source of this problem was recognized and solved.

Keywords: piston rider, rings, gas distribution, pressure wear

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Authors: Tsai-chun Huang, Xinyan Liu

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This paper presents an innovative targeted zoning design method for the back of gym wear, based on the visual mapping method for superficial skin deformation of back muscles discussed in Back Skin Deformation during Anaerobic Exercises for Ergonomics Application. The method involves developing a knitted self-pleating structure for areas of greater skin deformation, designed to match the range of superficial skin deformation of the back muscles during large-scale movements. Current research on the functional zoning design of gym wear primarily concentrates on the human sweat map, fat distribution map, and pressure distribution map, with a particular emphasis on the lower body. However, there remains a gap in research on targeted zoning design specifically addressing the superficial skin deformation on the back. Based on the visual muscle deformation images of three back resistance training movements discussed previously, the two images with the greatest overall color differences for each muscle visualization, indicating the highest degree of skin deformation, were overlaid in Photoshop to analyze the color depth distribution. The results show that the darkest areas are concentrated on the upper edge of the trapezius muscle and the upper edge of the latissimus dorsi muscle, suggesting that these regions experience the most significant superficial skin deformation during exercises. To ensure comfort and flexibility during exercise, the entire area of these two regions is preserved to prevent seams from intersecting the regions of greatest skin deformation, thereby reducing skin friction. The heat map indicates that the skin deformation range at the upper edge of the trapezius muscle is from -25% to 15%, while the upper edge of the latissimus dorsi muscle shows a deformation range of -25% to 25%. Based on these findings, the fabric structure and stretch range of the knitted self-pleating structure were developed and adjusted accordingly. According to the tensile test, the developed weft-knitted self-pleating structure has a stretch rate of -46.6% to 50%, which covers the stretch range of the main muscle groups in the back, indicating that the structure can be used to wrap the muscles in this area. For the remaining areas with skin deformation ranging from -15% to 15%, elastic knitted fabrics with spandex content were utilized to accommodate this range. Based on the skin deformation data, a partitioned gym vest prototype was designed and made. The significance of this study lies in providing an innovative methodology for gym wear design, particularly for gym wear involving a large range of motion and significant skin deformation. A distinctively developed knitted self-pleating structure is utilized in areas of extensive deformation, while a knitted fabric containing spandex is employed in areas with less deformation. This zoning design method enhances adaptability to the dynamic changes of human movement, allowing designers to more precisely select and adjust materials and structures. This approach not only improves athletes’ comfort and flexibility but also effectively reduces friction and binding of fabric on the skin during exercise, providing valuable insights for designers to create more reasonable and effective back area solutions for gym wear.

Keywords: zoning design, skin deformation, self-pleating structures, gym wear design, back muscle

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Authors: Mouldi Djelassi, Jamel Boukhatem

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Background: A relation has been established between Islamic banks' activities and interest rates. The aim of this study was to explore the impact of interest rates on the deposits and loans held by Islamic and conventional banks in Saudi Arabia. Methods: A time series data was performed over the period 2008Q1-2020Q2 on eight conventional banks and four Islamic banks. The impacts of interest rate shocks on deposits and loans were identified through panel vector autoregressive models. Results: Impulse response function analysis showed that increasing interest rates reduce loans and conventional deposits. For Islamic banks, deposits are more affected by interest rates than lending. Variance decomposition analysis revealed that deposits contribute to 61% of the Islamic financing variation and only 25% of the conventional loans. Conclusion: Interest rates impacted Islamic banks especially through deposits, which is inconsistent with the theoretical framework. Islamic deposits played an important role in Islamic financing variation and may provide to be a channel for the transmission of the monetary policy in a dual banking system. Monetary policy in Saudi Arabia works in part through “credits” (conventional bank credits) as well as through “money” (conventional and Islamic bank deposits).

Keywords: Islamic banking, interest rates, monetary policy transmission, panel VAR

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Authors: Rudi Van Nieuwenhove

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This paper explores a gravitational configuration arising as a solution to the Einstein field equations, grounded in a reinterpretation of the gravitational pseudo-tensor. The proposed solution encapsulates a stable, extended, and localized energy distribution that self-consistently generates its own gravitational field. By leveraging this methodology, we examine the structure’s properties and its compatibility with observations of galactic rotation curves. A detailed analysis demonstrates that the gravitational effects of this configuration align with the observed flat rotation curves of galaxies, such as the Milky Way, without requiring the introduction of additional material components. Using the Milky Way as a case study, we calculate the velocity profile induced by the structure and show its consistency with observed data across a range of galactic radii. The profiles of key physical quantities such as mass density, gravitational potential, radial pressure, and tangential pressure are derived and analyzed, revealing the intrinsic properties of the configuration. These profiles provide insight into the balance of forces that stabilize the structure and ensure its consistency with observations. Beyond rotation curves, the implications of this gravitational solution extend to broader cosmological phenomena. In particular, the structure offers a potential mechanism for enhanced gravitational clustering in the early universe, aiding in the rapid accumulation of baryonic matter and providing a pathway for the formation of the first galaxies. Additionally, the configuration’s energy distribution and spatial extension suggest possible interactions with the large-scale expansion of the universe, raising questions about its role in influencing cosmic acceleration. The methodology underlying this solution involves a re-evaluation of the energy-momentum tensor and its contribution to spacetime curvature, emphasizing the importance of non-local effects and self-consistent feedback mechanisms. This approach leads to a stable, scale-dependent configuration whose properties bridge the gap between small-scale structures and cosmological dynamics.

Keywords: einstein field equations, galactic rotation curves, gravitational pseudo-tensor, cosmological dynamics

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Authors: Ryan S. Johnson, Raeesa Moolla

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Airports are known air pollution hotspots due to the variety of fuel driven activities that take place within the confines of them. As such, people working within airports are particularly vulnerable to exposure of hazardous air pollutants, including hundreds of aromatic hydrocarbons, and more specifically a group of compounds known as BTEX (viz. benzene, toluene, ethyl-benzene and xylenes). These compounds have been identified as being harmful to human and environmental health. Through the use of passive and active sampling methods, the spatial and temporal variability of benzene, toluene, ethyl-benzene and xylene concentrations within the international airport was investigated. Two sampling campaigns were conducted. In order to quantify the temporal variability of concentrations within the airport, an active sampling strategy using the Synspec Spectras Gas Chromatography 955 instrument was used. Furthermore, a passive sampling campaign, using Radiello Passive Samplers was used to quantify the spatial variability of these compounds. In addition, meteorological factors are known to affect the dispersal and dilution of pollution. Thus a Davis Pro-Weather 2 station was utilised in order to measure in situ weather parameters (viz. wind speed, wind direction and temperature). Results indicated that toluene varied on a daily, temporal scale considerably more than other concentrations. Toluene further exhibited a strong correlation with regards to the meteorological parameters, inferring that toluene was affected by these parameters to a greater degree than the other pollutants. The passive sampling campaign revealed BTEXtotal concentrations ranged between 12.95 – 124.04 µg m-3. From the results obtained it is clear that benzene, toluene, ethyl-benzene and xylene concentrations are heterogeneously spatially dispersed within the airport. Due to the slow wind speeds recorded over the passive sampling campaign (1.13 m s-1.), the hotspots were located close to the main concentration sources. The most significant hotspot was located over the main apron of the airport. It is recommended that further, extensive investigations into the seasonality of hazardous air pollutants at the airport is necessary in order for sound conclusions to be made about the temporal and spatial distribution of benzene, toluene, ethyl-benzene and xylene concentrations within the airport.

Keywords: airport, air pollution hotspot, BTEX concentrations, meteorology

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Authors: Y. Lu, L. Liu, J. Guo

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Monolayer graphene and dichaclogenide semiconductor materials attract extensive research interest for potential nanoelectronics applications. The ultimate scaling limit of double gate MoS2 Field-Effect-Transistors (FETs) with a monolayer thin body is examined and compared with ultra-thin-body Si FETs by using self-consistent quantum transport simulation in the presence of phonon scattering. Modelling of phonon scattering, quantum mechanical effects, and self-consistent electrostatics allows us to accurately assess the performance potential of monolayer MoS2 FETs. The results revealed that monolayer MoS2 FETs show 52% smaller Drain Induced Barrier Lowering (DIBL) and 13% Smaller Sub-Threshold Swing (SS) than 3 nm-thick-body Si FETs at a channel length of 10 nm with the same gating. With a requirement of SS<100mV/dec, the scaling limit of monolayer MoS2 FETs is assessed to be 5 nm, comparing with 8nm of the ultra-thin-body Si counterparts due to the monolayer thin body and higher effective mass which reduces direct source-to-drain tunnelling. By comparing with the ITRS target for high performance logic devices of 2023; double gate monolayer MoS2 FETs can fulfil the ITRS requirements.

Keywords: nanotransistors, monolayer 2D materials, quantum transport, scaling limit

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Authors: Itziar Gonzalez, Pilar Carreras, Alberto Pinto, Roque Ruben Andres

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Acoustophoretic separation of plasma from blood is based on a collection process of the blood cells, driven by an acoustic radiation force. The number of cells, their concentration, and the sample hydrodynamics are involved in these processes. However, their influence on the acoustic blood response has not yet been reported in the literature. Addressing it, this paper presents an experimental study of blood samples exposed to ultrasonic standing waves at different hematocrit levels and hydrodynamic conditions. The experiments were performed in a glass capillary (700µm-square cross section) actuated by a piezoelectric ceramic at 1MHz, hosting 2D orthogonal half-wavelength resonances transverse to the channel length, with a single-pressure-node along its central axis where cells collected driven by the acoustic radiation force. Four blood dilutions in PBS of 1:20, 1:10, 1:5, and 1:2 were tested at eight flow rate conditions Q=0:120µL/min. The 1:5 dilution (H=9%) demonstrated to be optimal for the plasmapheresis at any of the flow rates analyzed, requiring the shortest times to achieve plasma free of cells. The study opens new possibilities to optimize processes of plasmapheresis processes by ultrasounds at different hematocrit conditions in future personalized diagnoses/treatments involving blood samples.

Keywords: ultrasounds, microfluidics, flow rate, acoustophoresis, polymeric resonators

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Authors: Vasudha Hegde, Narendra Chaulagain, H. M. Ravikumar, Sonu Mishra, Siva Yellampalli

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Acoustic sensors are extensively used in recent days not only for sensing and condition monitoring applications but also for small scale energy harvesting applications to power wireless sensor networks (WSN) due to their inherent advantages. The natural frequency of the structure plays a major role in energy harvesting applications since the sensor key element has to operate at resonant frequency. In this paper, circular diaphragm based MEMS acoustic sensor is modelled by Lumped Element Model (LEM) and the natural frequency is compared with the simulated model using Finite Element Method (FEM) tool COMSOL Multiphysics. The sensor has the circular diaphragm of 3000 µm radius and thickness of 30 µm to withstand the high SPL (Sound Pressure Level) and also to withstand the various fabrication steps. A Piezoelectric ZnO layer of thickness of 1 µm sandwiched between two aluminium electrodes of thickness 0.5 µm and is coated on the diaphragm. Further, a channel with radius 3000 µm radius and length 270 µm is connected at the bottom of the diaphragm. The natural frequency of the structure by LEM method is approximately 16.6 kHz which is closely matching with that of simulated structure with suitable approximations.

Keywords: acoustic sensor, diaphragm based, lumped element modeling (LEM), natural frequency, piezoelectric

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Authors: Frank Hespeler, Giuseppe Loiacono

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We propose measures for systemic risk generated through intra-sectorial interdependencies in the hedge fund sector. These measures are based on variations in the average cross-effects of funds showing significant interdependency between their individual returns and the moments of the sector’s return distribution. The proposed measures display a high ability to identify periods of financial distress, are robust to modifications in the underlying econometric model and are consistent with intuitive interpretation of the results.

Keywords: hedge funds, systemic risk, vector autoregressive model, risk monitoring

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Authors: Fedili Benamar, Belloulou Mohamed Lamine, Ouahes Hassane, Ghattas Samir

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Introduction: Perioperative blood loss is a frequent cause of complications in total hip replacement (THR). The present prospective study assessed the efficacy of tranexamic acid (Exacyl(®)) in reducing blood loss in primary THR. Hypothesis: Tranexamic acid reduces blood loss in THR. Material and method: -This is a prospective randomized study on the effectiveness of Exacyl (tranexamic acid) in total hip replacement surgery performed on a standardized technique between 2019 and September 2022. -It involved 154 patients, of which 84 received a single injection of Exacyl (group 1) at a dosage of 10 mg/kg over 20 minutes during the perioperative period. -All patients received postoperative thromboprophylaxis with enoxaparin 0.4 ml subcutaneously. -All patients were admitted to the post-interventional intensive care unit for a duration of 24 hours for monitoring and pain management as per the service protocol. Results: 154 patients, of which 84 received a single injection of Exacyl (group 1) and 70 patients patients who did not receive Exacyl perioperatively : (Group 2 ) The average age is 57 +/- 15 years The distribution by gender was nearly equal with 56% male and 44% female; "The distribution according to the ASA score was as follows: 20.2% ASA1, 82.3% ASA2, and 17.5% ASA3. "There was a significant difference in the average volume of intraoperative and postoperative bleeding during the 48 hours." The average bleeding volume for group 1 (received Exacyl) was 614 ml +/- 228, while the average bleeding volume for group 2 was 729 +/- 300, with a chi-square test of 6.35 and a p-value < 0.01, which is highly significant. The ANOVA test showed an F-statistic of 7.11 and a p-value of 0.008. A Bartlett test revealed a chi-square of 6.35 and a p-value < 0.01." "In Group 1 (patients who received Exacyl), 73% had bleeding less than 750 ml (Group A), and 26% had bleeding exceeding 750 ml (Group B). In Group 2 (patients who did not receive Exacyl perioperatively), 52% had bleeding less than 750 ml (Group A), and 47% had bleeding exceeding 750 ml (Group B). "Thus, the use of Exacyl reduced perioperative bleeding and specifically decreased the risk of severe bleeding exceeding 750 ml by 43% with a relative risk (RR) of 1.37 and a p-value < 0.01. The transfusion rate was 1.19% in the population of Group 1 (Exacyl), whereas it was 10% in the population of Group 2 (no Exacyl). It can be stated that the use of Exacyl resulted in a reduction in perioperative blood transfusion with an RR of 0.1 and a p-value of 0.02. Conclusions: The use of Exacyl significantly reduced perioperative bleeding in this type of surgery.

Keywords: acid tranexamic, blood loss, anesthesia, total hip replacement, surgery

Procedia PDF Downloads 80

Authors: Masoud Swalehe, Semra Günay

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Developed countries are losing many lives to non-communicable diseases as compared to their developing counterparts. The effects of these diseases are mostly sudden and manifest at a very short time prior to death or a dangerous attack and this has consolidated the significance of emergency medical system (EMS) as one of the vital areas of healthcare service delivery. The primary objective of this research is to reduce ambulance response times (RT) of Eskişehir province EMS since a number of studies have established a relationship between ambulance response times and survival chances of patients especially out of hospital cardiac arrest (OHCA) victims. It has been found out that patients who receive out of hospital medical attention in few (4) minutes after cardiac arrest because of low ambulance response times stand higher chances of survival than their counterparts who take longer times (more than 12 minutes) to receive out of hospital medical care because of higher ambulance response times. The study will make use of geographic information systems (GIS) technology to dynamically reallocate ambulance resources according to demand and time so as to reduce ambulance response times. Geospatial-time distribution of ambulance calls (demand) will be used as a basis for optimal ambulance deployment using system status management (SSM) strategy to achieve much demand coverage with the same number of ambulance resources to cause response time reduction. Drive-time polygons will be used to come up with time specific facility coverage areas and suggesting additional facility candidate sites where ambulance resources can be moved to serve higher demands making use of network analysis techniques. Emergency Ambulance calls’ data from 1st January 2014 to 31st December 2014 obtained from Eskişehir province health directorate will be used in this study. This study will focus on the reduction of ambulance response times which is a key Emergency Medical Services performance indicator.

Keywords: emergency medical services, system status management, ambulance response times, geographic information system, geospatial-time distribution, out of hospital cardiac arrest

Procedia PDF Downloads 304

Authors: Sospeter P. Maganga, Alphonce Wikedzi, Mussa D. Budeba, Samwel V. Manyele

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This study characterizes complex gold ores (elemental and mineralogical composition, gold distribution, ore grindability, and mineral liberation) for preliminary process selection. About 200 kg of ore samples were collected from each location using systematic sampling by mass interval. Ores were dried, crushed, milled, and split into representative sub-samples (about 1 kg) for elemental and mineralogical composition analyses using X-ray fluorescence (XRF), fire assay finished with Atomic Absorption Spectrometer (AAS), and X-ray Diffraction (XRD) methods, respectively. The gold distribution was studied on size-by-size fractions, while ore grindability was determined using the standard Bond test. The mineral liberation analysis was conducted using ThermoFisher Scientific Mineral Liberation Analyzer (MLA) 650, where unsieved polished grain mounts (80% passing 700 µm) were used as MLA feed. Two MLA measurement modes, X-ray modal analysis (XMOD) and sparse phase liberation-grain X-ray mapping analysis (SPL-GXMAP), were employed. At least two cyanide consumers (Cu, Fe, Pb, and Zn) and kinetics impeders (Mn, S, As, and Bi) were present in all locations investigated. Copper content at Kapanda (0.77% Cu) and Ibindi (7.48% Cu) exceeded the recommended threshold of 0.5% Cu for direct cyanidation. The gold ore at Ibindi indicated a higher rate of grinding compared to other locations. This could be explained by the highest grindability (2.119 g/rev.) and lowest Bond work index (10.213 kWh/t) values. The pyrite-marcasite, chalcopyrite, galena, and siderite were identified as major gold, copper, lead, and iron-bearing minerals, respectively, with potential for economic extraction. However, only gold and copper can be recovered under conventional milling because of grain size issues (galena is exposed by 10%) and process complexity (difficult to concentrate and smelt iron from siderite). Therefore, the preliminary process selection is copper flotation followed by gold cyanidation for Kapanda and Ibindi ores, whereas gold cyanidation with additives such as glycine or ammonia is selected for Mawemeru and Itumbi ores because of low concentrations of Cu, Pb, Fe, and Zn minerals.

Keywords: complex gold ores, mineral liberation, ore characterization, ore grindability

Procedia PDF Downloads 75

Authors: T. K. Dutta, K. K. Das, N. Dutta

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The salient feature of this paper is primarily concerned with Ricker’s population model: f(x)=x e^(r(1-x/k)), where r is the control parameter and k is the carrying capacity, and some fruitful results are obtained with the following objectives: 1) Determination of bifurcation values leading to a chaotic region, 2) Development of Statistical Methods and Analysis required for the measure of Fractal dimensions, 3) Calculation of various fractal dimensions. These results also help that the invariant probability distribution on the attractor, when it exists, provides detailed information about the long-term behavior of a dynamical system. At the end, some open problems are posed for further research.

Keywords: Feigenbaum universality, chaos, Lyapunov exponent, fractal dimensions

Procedia PDF Downloads 306

Authors: Alemayehu Muluneh, Saskia Keesstra, Leo Stroosnijder, Woldeamlak Bewket, Ashenafi Burka

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There are some scientific evidences and a belief by many that forests attract rain and deforestation contributes to a decline of rainfall. However, there is still a lack of concrete scientific evidence on the role of forests in rainfall amount. In this paper, we investigate the forest-rainfall relationships in the environmentally hot spot area of the Central Rift Valley (CRV) of Ethiopia. Specifically, we evaluate long term (1970-2009) rainfall variability and its relationship with historical forest cover and the relationship between existing forest cover and topographical variables and rainfall distribution. The study used 16 long term and 15 short term rainfall stations. The Mann-Kendall test, bi variate and multiple regression models were used. The results show forest and wood land cover continuously declined over the 40 years period (1970-2009), but annual rainfall in the rift valley floor increased by 6.42 mm/year. But, on the escarpment and highlands, annual rainfall decreased by 2.48 mm/year. The increase in annual rainfall in the rift valley floor is partly attributable to the increase in evaporation as a result of increasing temperatures from the 4 existing lakes in the rift valley floor. Though, annual rainfall is decreasing on the escarpment and highlands, there was no significant correlation between this rainfall decrease and forest and wood land decline and also rainfall variability in the region was not explained by forest cover. Hence, the decrease in annual rainfall on the escarpment and highlands is likely related to the global warming of the atmosphere and the surface waters of the Indian Ocean. Spatial variability of number of rainy days from systematically observed two-year’s rainfall data (2012-2013) was significantly (R2=-0.63) explained by forest cover (distance from forest). But, forest cover was not a significant variable (R2=-0.40) in explaining annual rainfall amount. Generally, past deforestation and existing forest cover showed very little effect on long term and short term rainfall distribution, but a significant effect on number of rainy days in the CRV of Ethiopia.

Keywords: elevation, forest cover, rainfall, slope

Procedia PDF Downloads 557

Authors: Ehsan Kadkhodaie, Shahin Parvar, Soroush Senemar, Mostafa Shriat, Abdolrasoul Malekpour

Abstract:

The role of oil in supra distribution transformers is so critical and, several standards in determining the quality of oil have been offered. So far, moisture, viscosity and insulation protection of the oil have been measured based on mechanical and chemical methods and systems such as kart fisher, falling ball and TDM 4000 that most of these techniques are destructive and have many problems such as pollution. In this study, due to the properties of oil and also physical behavior of ultrasound wave new method was designed to in the determination of oil indicators including viscosity and moisture. The results show the oil viscosity can be found from the relationship μ = 42.086/√EE and moisture from (PLUS+) = −15.65 (PPM) + 26040 relationship.

Keywords: oil, viscosity, moisture, ultrasonic waves

Procedia PDF Downloads 585