Search results for: saturation characteristics

Authors: Indrajeet Singh, Abhishek Gandhi, Smita Mohanty, S. K. Nayak

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In this article, a focused study has been performed to comprehend the influence of change in depressurization rate on microcellular polycarbonate foamed morphological attributes. The depressurization rate considered in this study were 0.5, 0.05, 0.01 and 0.005 MPa/sec and the physical blowing agent utilized was carbon dioxide owing to its high solubility in polycarbonate at room temperature. The study was performed on two distinct saturation pressures, i.e., 3 MPa and 6 MPa to understand if saturation pressure has any effects on it. It is reported that with increase in depressurization rate, a higher amount of thermodynamic instability was induced which resulted in generation of larger number of smaller sized cells. This article puts forward an understanding of how depressurization rate control could be well exploited during the batch foaming process to develop high quality microcellular foamed products with exceedingly well controlled cell size.

Keywords: depressurization, porous polymer, foaming, microcellular

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Authors: Quoc Khanh Dang, Thomas Bourdeaud’huy, Khaled Mesghouni, Armand Toguy´eni

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This paper studies a train routing and scheduling problem for busy railway stations. Our objective is to allow trains to be routed in dense areas that are reaching saturation. Unlike traditional methods that allocate all resources to setup a route for a train and until the route is freed, our work focuses on the use of resources as trains progress through the railway node. This technique allows a larger number of trains to be routed simultaneously in a railway node and thus reduces their current saturation. To deal with this problem, this study proposes an abstract model and a mixed-integer linear programming formulation to solve it. The applicability of our method is illustrated on a didactic example.

Keywords: busy railway stations, mixed-integer linear programming, offline railway station management, train platforming, train routing, train scheduling

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Authors: Ahmad Fahim Nasiry, Shigeo Honma

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We examine two-dimensional oil displacement by water in a petroleum reservoir. The pore fluid is immiscible, and the porous media is homogenous and isotropic in the horizontal direction. Buckley-Leverett theory and a combination of Laplacian and Darcy’s law are used to study the fluid flow through porous media, and the Laplacian that defines the dispersion and diffusion of fluid in the sand using heavy oil is discussed. The reservoir is homogenous in the horizontal direction, as expressed by the partial differential equation. Two main factors which are observed are the water saturation and pressure distribution in the reservoir, and they are evaluated for predicting oil recovery in two dimensions by a physical and mathematical simulation model. We review the numerical simulation that solves difficult partial differential reservoir equations. Based on the numerical simulations, the saturation and pressure equations are calculated by the iterative alternating direction implicit method and the iterative alternating direction explicit method, respectively, according to the finite difference assumption. However, to understand the displacement of oil by water and the amount of water dispersion in the reservoir better, an interpolated contour line of the water distribution of the five-spot pattern, that provides an approximate solution which agrees well with the experimental results, is also presented. Finally, a computer program is developed to calculate the equation for pressure and water saturation and to draw the pressure contour line and water distribution contour line for the reservoir.

Keywords: numerical simulation, immiscible, finite difference, IADI, IDE, waterflooding

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Authors: Ahmed Yousef A. Al Sultan

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Introduction: The aim of this review is based on clinical research that studies the changes in middle cerebral artery velocity using Transcranial Doppler (TCD) and cerebral oxygen saturation using cerebral oximetry in patients undergoing carotid endarterectomy (CEA) surgery under local anesthesia (LA). Patients with or without neurological symptoms during the surgery are taking a role in this study using triplet method of cerebral oximetry, transcranial doppler and awake test in detecting any cerebral ischemic symptoms. Methods: about one hundred patients took part during their CEA surgeries under local anesthesia, using triple assessment mentioned method, Patients requiring general anesthesia be excluded from analysis. All data were recorded at eight surgery stages separately to serve this study. Results: In total regional cerebral oxygen saturation (rSO2), middle cerebral artery (MCA) velocity, and pulsatility index were significantly decreased during carotid artery clamping step in CEA procedures on the targeted carotid side. With most observed changes in MCA velocity during the study. Discussion: Cerebral oxygen saturation and middle cerebral artery velocity were significantly decreased during clamping step of the procedures on the targeted side. The team with neurological symptoms during the procedures showed higher changes of rSO2 and MCA velocity than the team without neurological symptoms. Cerebral rSO2 and MCA velocity significantly increased directly after de-clamping of the internal carotid artery on the affected side.

Keywords: awake testing, carotid endarterectomy, cerebral oximetry, Tanscranial Doppler

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Authors: Huai-Cong Liu，Tae Chul Jeong，Ju Lee

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This paper describes characteristic analysis of a synchronous reluctance motor (SynRM)’s rotor with the Multi-segment and Multi-layer structure. The magnetic-saturation phenomenon in SynRM is often appeared. Therefore, when modeling analysis of SynRM the calculation of nonlinear magnetic field needs to be considered. An important influence factor on the convergence process is how to determine the relative permeability. An improved method, which ensures the calculation, is convergence by linear iterative method for saturated magnetic field. If there are inflection points on the magnetic curve,an optimum convergence method of solution for nonlinear magnetic field was provided. Then the equivalent magnetic circuit is calculated, and d,q-axis inductance can be got. At last, this process is applied to design a 7.5Kw SynRM and its validity is verified by comparing with the result of finite element method (FEM) and experimental test data.

Keywords: SynRM, magnetic-saturation, magnetic circuit, analytical modeling

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Authors: Mohit Chauhan, Atul Narayan

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Moisture damage is the continuous deterioration of asphalt concrete mixtures by the loss of adhesive bond between the asphalt binder and aggregates, or loss of cohesive bonds within the asphalt binder in the presence of moisture. Moisture has been known to either cause or exacerbates distresses in asphalt concrete pavements. Since moisture would often retain for a relatively long duration at the bottom of asphalt concrete layer, the movement of traffic loading in this saturated condition would cause excess stresses or strains within the mixture. This would accelerate the degradation of the adhesion and cohesion within the mixture and likely to contribute the development of fatigue cracking in asphalt concrete pavements. In view of this, it is important to investigate the effect of moisture on the fatigue behavior of asphalt concrete mixtures. In this study, changes in fatigue characteristics after moisture conditioning were evaluated by conducting four-point beam fatigue tests on dry and moisture conditioned specimens. For this purpose, mixtures with two different types of binders were prepared and saturated with moisture using 700 mm Hg vacuum. Beam specimens, in this way, were taken to a saturation level of 65-75 percent. After preconditioning specimens in this degree of saturation and 60°C for a period of 24 hours, they were subjected to four point beam fatigue tests in strain-controlled mode with a strain amplitude of 400 microstrain. The results were then compared with the fatigue test results obtained with beam specimens that were not subjected to moisture conditioning. Test results show that the conditioning reduces both fatigue life and initial flexural stiffness of specimen significantly. The moisture conditioning was also found to increase the rate of reduction of flexural stiffness. Moreover, it was observed that the fatigue life ratio (FLR), the ratio of the fatigue life of the moisture conditioned sample to that of the dry sample, is significantly lower than the flexural stiffness ratio (FSR). The study indicates that four-point bending test is an appropriate tool with FLR and FSR as the potential parameters for moisture-sensitivity evaluation.

Keywords: asphalt concrete, fatigue cracking, moisture damage, preconditioning

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Authors: Shilpa Bhilegaonkar, Ram Gaud

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Candesartan cilexetil is a poorly soluble antihypertensive agent with solubility limited bioavailability (15%). To initiate process of solubilisation, it is very much necessary to displace the air at the surface and wet the drug surface with a solvent, with which drug is compatible. Present research adopts the same principle to improve solubility and dissolution of candesartan cilexetil. Solvents used here are surfactant and modified surfactant in different drug: solvent (1:1-1:9) ratio’s for preparation of adsorbates. Adsorbates were then converted into free flowing powders as liquisolid compacts and compressed to form tablets. Liquisolid compacts were evaluated for improvement in saturation solubility and dissolution of candesartan cilexetil. All systems were evaluated for improvement in saturation solubility and dissolution in different medias such as water, 0.1 N HCl, Phosphate buffer pH 6.8 and media given by office of generic drugs along with other physicochemical testing. All systems exhibited a promising advantage in terms of solubility and dissolution without affecting the drug structure as confirmed by IR and XRD. No considerable advantage was seen of increasing solvent ratio with drug.

Keywords: candesartan cilexetil, improved dissolution, solubility, liquisolid

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Authors: Axel Priambodo, Dwiharso Nugroho

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Studies conducted to map the reservoir properties based on facies architecture in which to determine the distribution of the petrophysical properties and calculate hydrocarbon reserves in study interval. Facies Architecture analysis begins with stratigraphic correlation that indicates the area is divided into different system tracts. The analysis of distribution patterns and compiling core analysis with facies architecture model show that there are three estuarine facies appear. Formation evaluation begins with shale volume calculation using Asquith-Krygowski and Volan Triangle Method. Proceed to the calculation of the total and effective porosity using the Bateman-Konen and Volan Triangle Method. After getting the value of the porosity calculation was continued to determine the effective water saturation and non-effective by including parameters of water resistivity and resistivity clay. The results of the research show that the Facies Architecture on the field in divided into three main facies which are Estuarine Channel, Estuarine Sand Bar, and Tidal Flat. The petrophysics analysis are done by comparing different methods also shows that the Volan Triangle Method does not give a better result of the Volume Shale than the Gamma Ray Method, but on the other hand, the Volan Triangle Methode is better on calculating porosity compared to the Bateman-Konen Method. The effective porosity distributions are affected by the distribution of the facies. Estuarine Sand Bar has a low porosity number and Estuarine Channel has a higher number of the porosity. The effective water saturation is controlled by structure where on the closure zone the water saturation is lower than the area beneath it. It caused by the hydrocarbon accumulation on the closure zone.

Keywords: petrophysics, geology, petroleum, reservoir

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Authors: Shailendra Kumar, Lokesh Kashyap, Puneet Khanna, Nishant Patel, Rakesh Kumar, Arshad Ayub, Kelika Prakash, Yudhyavir Singh, Krithikabrindha V.

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Introduction: Spinal anesthesia is considered a standard anesthesia technique for caesarean delivery. The incidence of spinal hypotension during caesarean delivery is 70 -80%. Spinal hypotension may cause cerebral hypoperfusion in the mother, but physiologically cerebral autoregulatory mechanisms accordingly prevent cerebral hypoxia. Cerebral blood flow remains constant in the 50-150 mmHg of Cerebral Perfusion Pressure (CPP) range. Near-infrared spectroscopy (NIRS) is a non-invasive technology that is used to detect Cerebral Desaturation Events (CDEs) immediately compared to other conventional intraoperative monitoring techniques. Objective: The primary aim of the study is to correlate the change in cerebral oxygen saturation using NIRS with respect to a fall in mean blood pressure after spinal anaesthesia and to find out the effects of spinal hypotension on neonatal APGAR score, neonatal acid-base variations, and presence of Postoperative Delirium (POD). Methodology: NIRS sensors were attached to the forehead of all the patients, and their baseline readings of cerebral oxygenation on the right and left frontal regions and mean blood pressure were noted. Subarachnoid block was given with hyperbaric 0.5% bupivacaine plus fentanyl, the dose being determined by the individual anaesthesiologist. Co-loading of IV crystalloid solutions was given to the patient. Blood pressure reading and cerebral saturation were recorded every 1 minute till 30min. Hypotension was a fall in MAP less than 20% of the baseline values. Patients going for hypotension were treated with an IV Bolus of phenylephrine/ephedrine. Umbilical cord blood samples were taken for blood gas analysis, and neonatal APGAR was noted by a neonatologist. Study design: A prospective observational study conducted in a population of Thirty ASA 2 and 3 parturients scheduled for lower segment caesarean section (LSCS). Results: Mean fall in regional cerebral saturation is 28.48 ± 14.7% with respect to the mean fall in blood pressure 38.92 ± 8.44 mm Hg. The correlation coefficient between fall in saturation and fall in mean blood pressure is 0.057, and p-value {0.7} after subarachnoid block. A fall in regional cerebral saturation occurred 2±1 min before a fall in mean blood pressure. Twenty-nine out of thirty patients required vasopressors during hypotension. The first dose of vasopressor requirement is needed at 6.02±2 min after the block. The mean APGAR score was 7.86 and 9.74 at 1 and 5 min of birth, respectively, and the mean umbilical arterial pH of 7.3±0.1. According to DRS-98 (Delirium Rating Scale), the mean delirium rating score on postoperative day 1 and day 2 were 0.1 and 0.7, respectively. Discussion: There was a fall in regional cerebral oxygen saturation, which started before with respect to a significant fall in mean blood pressure readings but was statistically not significant. Maximal fall in blood pressure requiring vasopressors occurs within 10 min of SAB. Neonatal APGAR scores and acid-base variations were in the normal range with maternal hypotension, and there was no incidence of postoperative delirium in patients with post-spinal hypotension.

Keywords: cerebral oxygenation, LSCS, NIRS, spinal hypotension

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Authors: Reza Ziaie Moayed, Seyed Abdolhassan Naeini, Peyman Nouri, Hamed Yekehdehghan

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The shear strength of soils is a significant parameter in the design of clay structures, depots, clay gables, and freeways. Most research has addressed the shear strength of saturated soils. However, soils can become partially saturated with changes in weather, changes in groundwater levels, and the absorption of water by plant roots. Hence, it is necessary to study the strength behavior of partially saturated soils. The shear vane test is an experiment that determines the undrained shear strength of clay soils. This test may be performed in the laboratory or at the site. The present research investigates the effect of liquidity index (LI), plasticity index (PI), and saturation degree of the soil on its undrained shear strength obtained from the shear vane test. According to the results, an increase in the LI and a decrease in the PL of the soil decrease its undrained shear strength. Furthermore, studies show that a rise in the degree of saturation decreases the shear strength obtained from the shear vane test.

Keywords: liquidity index, plasticity index, shear strength, unsaturated soil

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Authors: Sarah Gaßmeyer, Nadine Hülsemann, Raphael Stoll, Kenji Miyamoto, Robert Kourist

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Enzymatic racemization allows the smooth interconversion of stereocenters under very mild reaction conditions. Racemases find frequent applications in deracemization and dynamic kinetic resolutions. Arylmalonate decarboxylase (AMDase) from Bordetella Bronchiseptica has high structural similarity to amino acid racemases. These cofactor-free racemases are able to break chemically strong CH-bonds under mild conditions. The racemase-like catalytic machinery of mutant G74C conveys it a unique activity in the racemisation of pharmacologically relevant derivates of 2-phenylpropionic acid (profenes), which makes AMDase G74C an interesting object for the mechanistic investigation of cofactor-independent racemases. Structure-guided protein engineering achieved a variant of this unique racemase with 40-fold increased activity in the racemisation of several arylaliphatic carboxylic acids. By saturation–transfer–difference NMR spectroscopy (STD-NMR), substrate binding during catalysis was investigated. All atoms of the substrate showed interactions with the enzyme. STD-NMR measurements revealed distinct nuclear Overhauser effects in experiments with and without molecular conversion. The spectroscopic analysis led to the identification of several amino acid residues whose variation increased the activity of G74C. While single-amino acid exchanges increased the activity moderately, structure-guided saturation mutagenesis yielded a quadruple mutant with a 40 times higher reaction rate. This study presents STD-NMR as versatile tool for the analysis of enzyme-substrate interactions in catalytically competent systems and for the guidance of protein engineering.

Keywords: racemase, rational protein design, STD-NMR, structure guided saturation mutagenesis

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Authors: Renée M. Ripken, Johannes G. E. Gardeniers, Séverine Le Gac

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Controlling the multiphase behavior of aqueous biomass mixtures is essential when working in the biomass conversion industry. Here, the vapor/liquid equilibria (VLE) of ethylene glycol, glycerol, and xylitol were studied for temperatures between 25 and 200 °C and pressures of 1 to 10 bar. These experiments were performed in a microfluidic platform, which exhibits excellent heat transfer properties so that equilibrium is reached fast. Firstly, the saturated vapor pressure as a function of the temperature and the substrate mole fraction of the substrate was calculated using AspenPlus with a Redlich-Kwong-Soave Boston-Mathias (RKS-BM) model. Secondly, we developed a high-pressure and high-temperature microfluidic set-up for experimental validation. Furthermore, we have studied the multiphase flow pattern that occurs after the saturation temperature was achieved. A glass-silicon microfluidic device containing a 0.4 or 0.2 m long meandering channel with a depth of 250 μm and a width of 250 or 500 μm was fabricated using standard microfabrication techniques. This device was placed in a dedicated chip-holder, which includes a ceramic heater on the silicon side. The temperature was controlled and monitored by three K-type thermocouples: two were located between the heater and the silicon substrate, one to set the temperature and one to measure it, and the third one was placed in a 300 μm wide and 450 μm deep groove on the glass side to determine the heat loss over the silicon. An adjustable back pressure regulator and a pressure meter were added to control and evaluate the pressure during the experiment. Aqueous biomass solutions (10 wt%) were pumped at a flow rate of 10 μL/min using a syringe pump, and the temperature was slowly increased until the theoretical saturation temperature for the pre-set pressure was reached. First and surprisingly, a significant difference was observed between our theoretical saturation temperature and the experimental results. The experimental values were 10’s of degrees higher than the calculated ones and, in some cases, saturation could not be achieved. This discrepancy can be explained in different ways. Firstly, the pressure in the microchannel is locally higher due to both the thermal expansion of the liquid and the Laplace pressure that has to be overcome before a gas bubble can be formed. Secondly, superheating effects are likely to be present. Next, once saturation was reached, the flow pattern of the gas/liquid multiphase system was recorded. In our device, the point of nucleation can be controlled by taking advantage of the pressure drop across the channel and the accurate control of the temperature. Specifically, a higher temperature resulted in nucleation further upstream in the channel. As the void fraction increases downstream, the flow regime changes along the channel from bubbly flow to Taylor flow and later to annular flow. All three flow regimes were observed simultaneously. The findings of this study are key for the development and optimization of a microreactor for hydrogen production from biomass.

Keywords: biomass conversion, high pressure and high temperature microfluidics, multiphase, phase diagrams, superheating

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Authors: Azadeh Askarinejad, Parmida Hayati, Parham Hayati, Reza Parchami

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Curing is a very important factor in the ultimate strength and durability of roller compacted concrete pavements (RCCP). Curing involves keeping the concrete is saturated or close to saturation point. Since maintaining concrete moisture has a significant impact on its mechanical properties, permeability and durability, curing is important. The most common procedure for curing of roller compacted concrete is using a white pigmented curing compound. This method is effective, economical and fast. In the present study, different curing compounds were applied on concrete specimens and the results of their effects on the mechanical properties were compared with each other and usual methods of curing in order to select appropriate materials and methods of curing for RCCP construction.

Keywords: curing compounds, roller compacted concrete pavements, mechanical properties, durability

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Authors: Iyagbaye O. Rich, Omoigberale O. Michael, Iyagbaye A. Louis

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The physical, chemical parameters and some trace contents of Ugbogui in Edo State, Nigeria were investigated from August 2015 to April 2016. Four stations were studied from upstream to downstream using standard methods. A total of thirty-three (33) physical and chemical characteristics and trace metal contents were examined; Air and water temperatures, depth, transparency, colour, turbidity, flow velocity, pH, total alkalinity, conductivity and dissolved solids etc. Other includes dissolved oxygen, oxygen saturation, biochemical oxygen demand, chloride, phosphate, sodium, nitrate, sulphate, potassium, calcium, magnesium, iron, lead, copper, zinc, nickel, cadmium, vanadium and chromium. Eleven (11) parameters exhibited clear seasonal variations. However, there were high significant differences (p < 0.01) in the values of depth, colour, total suspended solid, biochemical oxygen demand, chemical oxygen demand, chloride, bicarbonate, phosphate, sulphate, iron, manganese, zinc, copper, chromium and cadmium among the stations. The anthropogenic activities had negatively impacted at station 3 of the river, although most of the recorded values were still within permissible limits.

Keywords: anthropogenic activities, Nigeria, permissible limits, physical and chemical parameters, trace metal, water quality

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Authors: Karim Kootahi, Seyed Abolhasan Naeini

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The soil-water characteristic curve (SWCC), which represents the relationship between suction and water content (or degree of saturation), is an important property of unsaturated soils. The conventional method for determining SWCC is through specialized testing procedures. Since these procedures require specialized unsaturated soil testing apparatus and lengthy testing programs, several index properties-based correlations have been developed for estimating the SWCC of fine-grained soils. There are, however, considerable inconsistencies among the published correlations and there is no validation study on the predictive ability of existing correlations. In the present study, all existing index properties-based correlations are evaluated using a high quality worldwide database. The performances of existing correlations are assessed both graphically and quantitatively using statistical measures. The results of the validation indicate that most of the existing correlations provide unacceptable estimates of degree of saturation but the most recent model appears to be promising.

Keywords: SWCC, correlations, index properties, validation

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Authors: Dawit Burusie Abdi, Mamidala Jagadesh Kumar

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In this paper, using 2D TCAD simulations, the application of a dual material gate (DMG) for suppressing ambipolar conduction in a tunnel field effect transistor (TFET) is demonstrated. Using the proposed DMG concept, the ambipolar conduction can be effectively suppressed even if the drain doping is as high as that of the source doping. Achieving this symmetrical doping, without the ambipolar conduction in TFETs, gives the advantage of realizing both n-type and p-type devices with the same doping sequences. Furthermore, the output characteristics of the DMG TFET exhibit a good saturation when compared to that of the gate-drain underlap approach. This improved behavior of the DMG TFET makes it a good candidate for inverter based logic circuits.

Keywords: dual material gate, suppressing ambipolar current, symmetrically doped TFET, tunnel FETs, PNPN TFET

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Authors: David Lall, Vikram Vishal, P. G. Ranjith

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Numerical modeling of gas production from hydrate-bearing reservoirs requires the solution of various thermal, hydrological, chemical, and mechanical phenomena in a coupled manner. Among the various reservoir properties that influence gas production estimates, the distribution of permeability across the domain is one of the most crucial parameters since it determines both heat transfer and mass transfer. The aspect of permeability in hydrate-bearing reservoirs is particularly complex compared to conventional reservoirs since it depends on the saturation of gas hydrates and hence, is dynamic during production. The dependence of permeability on hydrate saturation is mathematically represented using permeability-reduction models, which are specific to the expected morphology of hydrate accumulations (such as grain-coating or pore-filling hydrates). In this study, we demonstrate the impact of various permeability-reduction models, and consequently, different morphologies of hydrate deposits on the estimates of gas production using depressurization at the reservoir scale. We observe significant differences in produced water volumes and cumulative mass of produced gas between the models, thereby highlighting the uncertainty in production behavior arising from the ambiguity in the prevalent gas hydrate morphology.

Keywords: gas hydrate morphology, multi-scale modeling, THMC, fluid flow in porous media

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Authors: Huai-Cong Liu, Tae Chul Jeong, Ju Lee

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The aim of this study was to develop an electric circuit method (ECM) to ascertain the core loss influence on a Synchronous Reluctance Motor (SynRM) in the condition of the maximum torque per ampere (MTPA). SynRM for fan usually operates on the constant torque region, at synchronous speed the MTPA control is adopted due to current vector. However, finite element analysis (FEA) program is not sufficient exactly to reflect how the core loss influenced on the current vector. This paper proposed a method to calculate the current vector with consideration of core loss. The precision of current vector by ECM is useful for MTPA control. The result shows that ECM analysis is closer to the actual motor’s characteristics by testing with a 7.5kW SynRM drive System.

Keywords: core loss, SynRM, current vector, magnetic saturation, maximum torque per ampere (MTPA)

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Authors: A. Khosravi, S. Ghadirian, J. S. McCartney

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Evaluation of the seismic-induced settlement of an unsaturated soil layer depends on several variables, among which the small strain shear modulus, Gmax, and soil’s state of stress have been demonstrated to be of particular significance. Recent interpretation of trends in Gmax revealed considerable effects of the degree of saturation and hydraulic hysteresis on the shear stiffness of soils in unsaturated states. Accordingly, the soil layer is expected to experience different settlement behaviors depending on the soil saturation and seasonal weathering conditions. In this study, a semi-empirical formulation was adapted to extend an existing Gmax model to infer hysteretic effects along different paths of the SWRC including scanning curves. The suitability of the proposed approach is validated against experimental results from a suction-controlled resonant column test and from data reported in literature. The model was observed to follow the experimental data along different paths of the SWRC, and showed a slight hysteresis in shear modulus along the scanning curves.

Keywords: hydraulic hysteresis, scanning path, small strain shear modulus, unsaturated soil

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Authors: Habes Sameh, Bettahar Asma, Nezli Imad Eddine

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The region of Touggourt is situated in the southern part is Algeria, it receives important quantities of waters, the latter are extracted from the fossil groundwater (the Intercalary Continental and the Terminal Complex). The mineralization of these waters of the Terminal Complex is between 3 and 6,5 g/l and for waters of Intercalary Continental is 1,8 and 8,7 g/l, thus it constitutes an obstacle as for its use. To highlight the origins of this mineralization, we used the hydrochemical tool. So the chemical analyses in our ownership, were treated by means of the software "Statistica", what allowed us to realize an analysis in main components (ACP), the latter showed a competition between sodic or magnesian chlorinated water and calcic bicarbonate water, rich in potassium for the TC, while for the IC, we have a competition between sodic or calcic chlorinated and magnesian water treated with copper sulphate waters. The simulation realized thermodynamics showed a variation of the index of saturation which do not exceed zero, for waters of two aquifer TC and IC, so indicating one under saturation of waters towards minerals, highlighting the influence of the geologic formation in the outcrop on the quality of waters. However, we notice that these waters remain acceptable for the irrigation of plants but must be treated before what are consumed by the human being.

Keywords: ACP, intercalary, continental, mineralization, SI, Terminal Complex

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Authors: Khashayar Kazemzadeh, Mohammad Hanif Dasoomi

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According to the increasing volume of traffic, lane changing plays a crucial role in traffic flow. Lane changing in traffic depends on several factors including road geometrical design, speed, drivers’ behavioral characteristics, etc. A great deal of research has been carried out regarding these fields. Despite of the other significant factors, the drivers’ behavioral characteristics of lane changing has been emphasized in this paper. This paper has predicted the effective equation based on personal characteristics of lane changing by regression models.

Keywords: effective equation, lane changing, drivers’ behavioral characteristics, regression models

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Authors: Oluwagbenga O. Isaac Orimoogunje, Omolola Helen Oshosanya

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The study examined land management in a typical watershed in southwestern Nigeria with a view to ascertaining its impact on land suitability analysis for rice cultivation and production. The study applied the analytical hierarchy process (AHP), weighted overlay analysis (WOA), multi-criteria decision-making techniques, and suitability map calculations within a Geographic Information System environment. Five main criteria were used, and these include climate, topography, soil fertility, macronutrients, and micronutrients. A consistency ratio (CR) of 0.067 was obtained for rice cultivation. The results showed that 95% of the land area is suitable for rice cultivation, with pH units ranging between 4.6 and 6.0, organic matter of 1.4–2.5 g kg-1 and base saturation of more than 80%. The study concluded that the Ofiki watershed is a potential site for large-scale rice cultivation in a sustainable capacity.

Keywords: land management, land characteristics, land suitability, rice production, watershed

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Authors: Sami Aboujafar

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Oil recovery in petroleum reservoirs is greatly affected by fluid-rock and fluid-fluid interactions. These interactions directly control rock wettability, capillary pressure and relative permeability curves. Laboratory core-floods and centrifuge experiments were conducted on sandstone and carbonate cores to study the effect of low and high brine salinity and viscosity and oil viscosity on residual saturations and relative permeability. Drainage and imbibition relative permeability in two phase system were measured, refined lab oils with different viscosities, heavy and light, and several brine salinities were used. Sensitivity analysis with different values for the salinity and viscosity of the fluids,, oil and water, were done to investigate the effect of these properties on water/oil relative permeability, residual oil saturation and oil recovery. Experiments were conducted on core material from viscous/heavy and light oil fields. History matching core flood simulator was used to study how the relative permeability curves and end point saturations were affected by different fluid properties using several correlations. Results were compared with field data and literature data. The results indicate that there is a correlation between the oil viscosity and/or brine salinity and residual oil saturation and water relative permeability end point. Increasing oil viscosity reduces the Krw@Sor and increases Sor. The remaining oil saturation from laboratory measurements might be too high due to experimental procedures, capillary end effect and early termination of the experiment, especially when using heavy/viscous oil. Similarly the Krw@Sor may be too low. The effect of wettability on the observed results is also discussed. A consistent relationship has been drawn between the fluid parameters, water/oil relative permeability and residual saturations, and a descriptor may be derived to define different flow behaviors. The results of this work will have application to producing fields and the methodologies developed could have wider application to sandstone and carbonate reservoirs worldwide.

Keywords: history matching core flood simulator, oil recovery, relative permeability, residual saturations

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Authors: Huseyin Kavas

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Oleic acid (OA) capped superparamagnetic iron oxide nanoparticles (SPION) were synthesized by a thermal decomposition method. The composition of nanoparticles was confirmed by X-ray powder diffraction, and the morphology of particles was investigated by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and Transmission electron microscopy (TEM). The crystalline and particle size distribution of SPIONS capped with OA were investigated with a mean size of 6.99 nm and 8.9 nm, respectively. It was found that SPIONS have superparamagnetic characteristics with a saturation magnetization value of 64 emu/g. The thin film form of self-assembled SPIONS was fabricated by coating techniques of spin coating and dip coating. SQUID-VSM magnetometer and FMR techniques were performed in order to evaluate the magnetic properties of thin films, especially the existence of magnetic anisotropy. The thin films with magnetic anisotropy were obtained by self-assembled monolayers of SPION.

Keywords: magnetic materials, nanostructures, self-assembly, FMR

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Authors: Dong Chen, Han Song, Tingting Wei

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Industrial zones have made significant contributions to the economic development of Chinese urban areas for decades. In the background of China's New Normal, numbers of mature industrial zones are stepping into a new stage of inventory development instead of increment development. The aim of this study is to discover new characteristics and problems and corresponding inventory planning guidance of mature industrial zones. A case of Yangzhou Hi-Tech Industrial Development Zone is reported in this study. Based on a historical analysis and data analysis of land-use, it is found that land-use of the zone is near saturation and signs of land updating have begun to appear. It is observed that the zone is facing problems including disorder of land development, low economic productivity and single function. Through the data of economic output, tax contribution, industrial category, industry life cycle and environmental influence, a comprehensive assessment based on two dimensions, economic benefits and industrial matchup, is made upon every parcel in the zone. According to the assessment, the zone is divided into spatial units of the update with specific planning guidance. It comes to a conclusion as four directions of inventory planning guidance in mature industrial zones: moving industries with poor economic benefit and negative environmental influence, adding urban function and new industrial function to the zone, optimizing the function of important space, and restricting the mass layout of the real estate industry to provide space for industrial upgrading.

Keywords: China's new normal, mature industrial zones, land-use, inventory planning

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Authors: Dinku Seyoum Zeleke, Rong Fung Huang, Ching Min Hsu

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Comparison of flow and mixing characteristics between non-oscillating jet and transversely oscillating jet was investigated experimentally. Flow evolution process was detected by using high-speed digital camera, and jet spread width was calculated using binary edge detection techniques by using the long-exposure images. The velocity characteristics of transversely oscillating jet induced by a V-shaped fluidic oscillator were measured using single component hot-wire anemometer. The jet spread width of non-oscillating jet was much smaller than the jet exit gap because of behaving natural jet behaviors. However, the transversely oscillating jet has a larger jet spread width, which was associated with the excitation of the flow by self-induced oscillation. As a result, the flow mixing characteristics desperately improved both near-field and far-field. Therefore, this transversely oscillating jet has a better turbulence intensity, entrainment, and spreading width so that it augments flow-mixing characteristics desperately.

Keywords: flow mixing, transversely oscillating, spreading width, velocity characteristics

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Authors: Suresh Ramachandra

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Accounting values of firms are determined by strategies that firms pursue which are influenced by board characteristics specific to firms. Using two broad constructs of board characteristics, namely, board capital and board control, in the Malaysian context, this research attempts to infer their conjoint relevance to accounting values. The results of this research indicate that firms are able to increase their accounting values by deliberately selecting board characteristics which include director reputation and political affiliations.

Keywords: accounting values, board characteristics, board capital, board control

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Authors: Bhavna Malik

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The study is build on a theoretical framework that links characteristics of job, key attitudes and intention to leave, why faculty may be disengaging from institutional service. The literature indicates that job characteristics, key attitudes and intention to leave are very important for effective organizational functioning. In general, the literature showed that some job characteristics might be the antecedents of job satisfaction and the aggregate variable job scope was positively associated with organizational commitment, and these key attitudes predicted intention to leave negatively. The present study attempted to propose a new integrative model of the relationships among job characteristics, key attitudes, and intention to leave. The main purpose of the present study is to examine the effects of job characteristics on intention to leave. While examining the role of job characteristics, the mediating roles of key attitudes were taken into account in order to better understand how job characteristics affect the exhibition of intention to leave. The secondary purpose is to investigate the effects of job characteristics on key attitudes, and the effects of key attitudes on intention to leave. Job characteristics of remuneration, resource for professional activities, career opportunities were positively associated with the work attitude of job satisfaction. The aggregate job scope was positively associated with the work attitude of organizational commitment although no single job characteristic was significantly associated with organizational commitment. Commitment, however, did not significantly affect time spent on institutional service. Two job characteristics—time spent on research and time spent on teaching—were negatively associated with this behavior. In general, the literature showed that some job characteristics might be the antecedents of job satisfaction and the aggregate variable job scope was positively associated with organizational commitment, and these key attiudes predicted intention to leave negatively. In turn, job satisfaction and organizational commitment were negatively associated with the intention to leave. In addition to these, organizational commitment was negatively associated with the intention to leave. However, no significant direct association was found between job characteristics and intention to leave.

Keywords: Job Characteristics Model, job satisfaction, organizational commitment, intention to leave

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Authors: V. Stejskal, K. Lundova, R. Sebesta, T. Vanina, S. Roje

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Pure strain of Arctic char (AC) Salvelinus alpinus and hybrid (HB) Salvelinus alpinus vs. Salvelinus fontinalis Mitchill belong to fish, which with great potential for culture in recirculating aquaculture systems (RAS). Aquaculture of these fish currently use flow-through systems (FTS), especially in Nordic countries such as Iceland (biggest producer), Norway, Sweden, and Canada. Four different water saturation regimes included normoxia (NOR), permanent hyperoxia (HYP), intermittent hyperoxia (HYP ± ) and regimes where one day of normoxia was followed by one day of hyperoxia (HYP1/1) were tested during 63 days of experiment in both species in two parallel experiments. Fish were reared in two identical RAS system consisted of 24 plastic round tanks (300 L each), drum filter, biological filter with moving beads and submerged biofilter. The temperature was maintained using flow-through cooler during at level of 13.6 ± 0.8 °C. Different water saturation regimes were achieved by mixing of pure oxygen (O₂) with water in three (one for each hyperoxic regime) mixing tower equipped with flowmeter for regulation of gas inflow. The water in groups HYP, HYP1/1 and HYP± was enriched with oxygen up to saturation of 120-130%. In HYP group was this level kept during whole day. In HYP ± group was hyperoxia kept for daylight phase (08:00-20:00) only and during night time was applied normoxia in this group. The oxygen saturation of 80-90% in NOR group was created using intensive aeration in header tank. The fish were fed with commercial feed to slight excess at 2 h intervals within the light phase of the day. Water quality parameters like pH, temperature and level of oxygen was monitoring three times (7 am, 10 am and 6 pm) per day using handy multimeter. Ammonium, nitrite and nitrate were measured in two day interval using spectrophotometry. Initial body weight (BW) was 40.9 ± 8.7 g and 70.6 ± 14.8 in AC and HB group, respectively. Final survival of AC ranged from 96.3 ± 4.6 (HYP) to 100 ± 0.0% in all other groups without significant differences among these groups. Similarly very high survival was reached in trial with HB with levels from 99.2 ± 1.3 (HYP, HYP1/1 and NOR) to 100 ± 0.0% (HYP ± ). HB fish showed best growth performance in NOR group reached final body weight (BW) 180.4 ± 2.3 g. Fish growth under different hyperoxic regimes was significantly reduced and final BW was 164.4 ± 7.6, 162.1 ± 12.2 and 151.7 ± 6.8 g in groups HY1/1, HYP ± and HYP, respectively. AC showed different preference for hyperoxic regimes as there were no significant difference in BW among NOR, HY1/1 and HYP± group with final values of 72.3 ± 11.3, 68.3 ± 8.4 and 77.1 ± 6.1g. Significantly reduced growth (BW 61.8 ± 6.8 g) was observed in HYP group. It is evident from present study that there are differences between pure bred Arctic char and hybrid in relation to hyperoxic regimes. The study was supported by projects 'CENAKVA' (No. CZ.1.05/2.1.00/01.0024), 'CENAKVA II' (No. LO1205 under the NPU I program), NAZV (QJ1510077) and GAJU (No. 060/2016/Z).

Keywords: recirculating aquaculture systems, Salmonidae, hyperoxia, abiotic factors

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Authors: Ali Bakhtiari Gharibdosti, Mohammad Hosein Bijeh Keshavarzi, Samira Alijani

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To understand internal characteristics relationships and determine factors which explain under consideration characteristics in rapeseed varieties, 10 rapeseed genotypes were implemented in complete accidental plot with three-time repetitions under drought stress in 2009-2010 in research field of agriculture college, Islamic Azad University, Karaj branch. In this research, 11 characteristics include of characteristics related to growth, production and functions stages was considered. Variance analysis results showed that there is a significant difference among rapeseed varieties characteristics. By calculating simple correlation coefficient under both conditions, normal and drought stress indicate that seed function characteristics in plant and pod number have positive and significant correlation in 1% probable level with seed function and selection on the base of these characteristics was effective for improving this function. Under normal and drought stress, analyzing the main factors showed that numbers of factors which have more than one amount, had five factors under normal conditions which were 82.72% of total variance totally, but under drought stress four factors diagnosed which were 76.78% of total variance. By considering total results of this research and by assessing effective characteristics for factor analysis and selecting different components of these characteristics, they can be used for modifying works to select applicable and tolerant genotypes in drought stress conditions.

Keywords: correlation, drought stress, factor analysis, rapeseed

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