Search results for: separation index

Authors: Mei Hong, Wei Liu, Xuemin Dai, Yanxiong Pan, Xiangling Ji

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Polyamic acid (PAA) is the precursor of polyimide (PI) prepared by a two-step method, its molecular weight and molecular weight distribution not only play an important role during the preparation and processing, but also influence the final performance of PI. However, precise characterization on molecular weight of PAA is still a challenge because of the existence of very complicated interactions in the solution system, including the electrostatic interaction, hydrogen bond interaction, dipole-dipole interaction, etc. Thus, it is necessary to establisha suitable strategy which can completely suppress these complex effects and get reasonable data on molecular weight. Herein, the gel permeation chromatography (GPC) coupled with differential refractive index (RI) and multi-angle laser light scattering (MALLS) detectors were applied to measure the molecular weight of (6FDA-DMB) PAA using different mobile phases, LiBr/DMF, LiBr/H3PO4/THF/DMF, LiBr/HAc/THF/DMF, and LiBr/HAc/DMF, respectively. It was found that combination of LiBr with HAc can shield the above-mentioned complex interactions and is more conducive to the separation of PAA than only addition of LiBr in DMF. LiBr/HAc/DMF was employed for the first time as a mild mobile phase to effectively separate PAA and determine its molecular weight. After a series of conditional experiments, 0.02M LiBr/0.2M HAc/DMF was fixed as an optimized mobile phase to measure the relative and absolute molecular weights of (6FDA-DMB) PAA prepared, and the obtained Mw from GPC-MALLS and GPC-RI were 35,300 g/mol and 125,000 g/mol, respectively. Particularly, such a mobile phase is also applicable to other PAA samples with different structures, and the final results on molecular weight are also reproducible.

Keywords: Polyamic acids, Polyelectrolyte effects, Gel permeation chromatography, Mobile phase, Molecular weight

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Authors: Marieta Safta

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The separation and balance of state powers constitute the basis of the rule of law. Observance of this principle requires framing of public authorities within the limits of competence established by the Constitution and the law, as well as loyal cooperation between them. From this perspective, the attribution of the constitutional courts for settling legal conflicts of a constitutional nature is an important tool for correcting the tendencies of violation of these limits, as well as for identifying solutions for situations that do not find an explicit regulation in the constitutional texts. The present study analyzes the jurisprudence of the Constitutional Court of Romania in the field of legal conflicts of a constitutional nature, revealing, together with the presentation of conflict situations, the vulnerabilities of the constitutional reference texts. It is also highlighted the role of the constitutional courts in the evolution of constitutional law institutions, even in terms of defining and redefining the regime of the forms of government. The conclusion of the study, beyond the subject of legal conflicts of a constitutional nature, bears on the necessity, even more so in this matter, of the certainty of jurisdictional interpretation. This certainty cannot be achieved as long as the interpretation is not authoritative; consequently, the assurance of the effectiveness of constitutional justice constitute a key issue of the rule of law.

Keywords: legal conflicts of constitutional nature, the Constitutional Court of Romania, the separation and balance of powers in the state, the effectiveness of constitutional justice

Procedia PDF Downloads 123

Authors: Suprit Pradhan, Tshering Yangzom

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Even with availability of the modern day online insulation diagnostic technologies like partial discharge monitoring, the measurements like Dissipation Factor (tanδ), DC High Voltage Insulation Currents, Polarization Index (PI) and Insulation Resistance Measurements are still widely used as a diagnostic tools to assess the condition of stator insulation in hydro power plants. To evaluate the condition of stator winding insulation in one of the generators that have been operated since 1999, diagnostic tests were performed on the stator bars of 15 MVA generators of Basochhu Hydropower Plant. This paper presents diagnostic study done on the data gathered from the measurements which were performed in 2015 and 2016 as part of regular maintenance as since its commissioning no proper aging data were maintained. Measurement results of Dissipation Factor, DC High Potential tests and Polarization Index are discussed with regard to their effectiveness in assessing the ageing condition of the stator insulation. After a brief review of the theoretical background, the strengths of each diagnostic method in detecting symptoms of insulation deterioration are identified. The interesting results observed from Basochhu Hydropower Plant is taken into consideration to conclude that Polarization Index and DC High Voltage Insulation current measurements are best suited for the detection of humidity and contamination problems and Dissipation Factor measurement is a robust indicator of long-term ageing caused by oxidative degradation.

Keywords: dissipation Factor (tanδ), polarization Index (PI), DC High Voltage Insulation Current, insulation resistance (IR), Tan Delta Tip-Up, dielectric absorption ratio

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Authors: Netsanet Kebede Hundessa

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Substrate modification of thin film composite (TFC) membranes with various crosslinkers is typically necessary for organic solvent nanofiltration (OSN) applications. This modification is aimed at enhancing membrane stability and solvent resistance, but it often results in a decline in permeance. This study introduces a distinct approach by developing a coordination-crosslinked polyimide substrate, which differs from the covalently-crosslinked substrates traditionally used. This developed substrate achieves enhanced solvent resistance, improved hydrophilicity, and optimized porous microstructure simultaneously. The study investigates the effects of an alkaline coagulation bath, subsequent ion exchange, and further solvent activation. The resulting TFC membrane successfully overcomes the typical permeability-selectivity trade-off of OSN membranes. It demonstrates significantly improved solvent permeance (1.5–2 times higher than previously reported data) with values of 65.2 LMH/bar for methanol, 33.1 LMH/bar for ethanol, and 59.1 LMH/bar for acetone while maintaining competitive solute rejection (>98% for Rose Bengal). This research is expected to provide a new direction for developing high-performance OSN composite membranes and other separation applications.

Keywords: metal coordinatiom, thin film composite membrane, organic solvent nanofiltration, solvent activation

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Authors: Asmaa Selim, Peter Mizsey

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Bio-ethanol is considered of higher potential as a green renewable energy source owing to its environmental benefits and its high efficiency. In the present study, silver nanoparticles were in-situ generated in a poly (vinyl alcohol) in order to improve its potentials for pervaporation of ethanol-water mixture using solution-casting. Effect of silver content on the pervaporation separation index and the enrichment factor of the membrane at 15 percentage mass water at 40ᵒC was reported. Pervaporation data for nanocomposite membranes showed around 100% increase in the water permeance values while the intrinsic selectivity decreased. The water permeances of origin crosslinked PVA membrane, and the 2.5% silver loaded PVA membrane are 26.65 and 70.45 (g/m².kPa.h) respectively. The values of total flux and water flux are closed to each other, indicating that membranes could be effectively used to break the azeotropic point of ethanol-water. Effect of temperature on the pervaporation performance, permeation parameter and diffusion coefficient of both water and ethanol was discussed. The negative heat of sorption ∆Hs values calculated on the basis of the estimated Arrhenius activation energy values indicating that the sorption process was controlled by Langmuir’s mode. The overall results showed that the membrane containing 0.5 mass percentage of Ag salt exhibited excellent PV performance.

Keywords: bio-ethanol, diffusion coefficient, nanocomposite, pervaporation, poly (vinyl alcohol), silver nanoparticles

Procedia PDF Downloads 164

Authors: Han-Wei Shih, Yao-Nan Wang, Ko-Tung Chang, Lung-Ming Fu

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A multi-channel cell growth real-time monitor and evaluation system using charge-coupled device (CCD) sensors with 40X lens integrating a NI LabVIEW image processing program is proposed and demonstrated. The LED light source control of monitor system is utilizing 8051 microprocessor integrated with NI LabVIEW software. In this study, the same concentration RAW264.7 cells growth rate and morphology in four different culture conditions (DMEM, LPS, G1, G2) were demonstrated. The real-time cells growth image was captured and analyzed by NI Vision Assistant every 10 minutes in the incubator. The image binarization technique was applied for calculating cell doubling time and cell division index. The cells doubling time and cells division index of four group with DMEM, LPS, LPS+G1, LPS+G2 are 12.3 hr,10.8 hr,14.0 hr,15.2 hr and 74.20%, 78.63%, 69.53%, 66.49%. The image magnification of multi-channel CCDs cell real-time monitoring system is about 100X~200X which compares with the traditional microscope.

Keywords: charge-coupled device (CCD), RAW264.7, doubling time, division index

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Authors: Dong Wook Lee, Seung Hyun Kim

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Geological structure formed by volcanic activities shows polymorphic characteristics due to repeated cooling and hardening of lava. The Jeju region is showing polymorphic characteristics in which clinker layers are irregularly distributed along with vesicular basalt due to volcanic activities. Accordingly, resident damages and environmental disputes occur frequently in the Jeju region due to blasting. The purpose of this study is to develop a blast vibration equation considering the polymorphic characteristics of basaltic ground in Jeju. The blast vibration equation consists of a functional formula of the blasting vibration constant K that changes according to ground characteristics, and attenuation index n. The case study results in Jeju showed that if there are clinker layers, attenuation index n showed a distribution of -1.11~-1.87, whereas if there are no clinker layers, n was -2.79. Moreover, if there are no clinker layers, the frequency of blast vibration showed a high frequency band from 30Hz to 100Hz, while in rocks with clinker layers it showed a low frequency band from 10Hz to 20Hz.

Keywords: blast vibration equation, basaltic ground, clinker layer, blasting vibration constant, attenuation index

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Authors: Peramachi Sathiyamoorthy, Jacop Gopas, Avi Golan Goldhirsh

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Corchorus olitorius is a leafy vegetable and an industrial crop. The herb has antioxidant, anti inflammatory, and anti-cancer properties. To assay the pharmaceutical properties, aqueous extracts of leaves and seeds from C. olitorius were tested against drug resistant melanoma cell line. The test showed LC50 of the extract was 0.08µg/ml. Aqueous seed extract exhibited higher melanoma inhibiting activity than leaf extract. Dialysis of seed extract showed that the active compound is less than 12 KDa. The compound with <3 KDa MW separated by microconcentration of seed extract showed 70.5 % inhibition of melanoma cell growth. Among the two fractions obtained by Gel filtration with G10 column, the first fraction at 1:2000 dilutions exhibited 100% inhibition of melanoma growth. The compound with Rf value 0.86 (MA4) isolated by TLC separation showed about 98% cytotoxicity against melanoma at 1: 1000 dilutions. Furthermore, HPLC separation of MA4 compound with Superdex 75 column resulted in 4 compounds. Out of 4, one compound showed melanoma inhibition. The active compound is identified by reagent methods as Strophanthidin. Further toxicological and clinical studies will lead to the development of a potential drug to treat drug resistant melanoma.

Keywords: corchorus olitorius, melanoma, drug development, strophanthidin

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Authors: Alireza Javadzadeh

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Background: The purpose of this prospective, randomized study was to compare the safety and efficacy of oral versus i.v. midazolam in providing sedation for pediatric upper gastrointestinal (GI) endoscopy. Methods: Sixty-one children (age < 16 years) scheduled for upper GI endoscopy were studied. Patients were randomly assigned to receive oral or i.v. midazolam. Measurements were made and compared for vital signs, level of sedation, pre- and post-procedure comfort, anxiety during endoscopy, ease of separation from parents, ease and duration of procedure, and recovery time. Results: Patients were aged 1–16 years (mean 7.5 ± 3.42 years); 30 patients received oral medication, and 31 received i.v. medication. There were no statistically significant differences in age or gender between groups. There were no significant differences in level of sedation, ease of separation from parents, ease of ability to monitor the patient during the procedure, heart rate, systolic arterial pressure, or respiratory rate. Oxygen saturation was significantly lower in the i.v. group than the oral group 10 and 30 min after removal of the endoscope, and recovery time was longer in the oral than the i.v. group. Conclusions: Oral administration of midazolam is a safe and effective method of sedation that significantly reduces anxiety and improves overall tolerance for children undergoing esophagogastroduodenoscopy.

Keywords: children, endoscopy, midazolam, oral, sedation

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Authors: Kornelius Ronald Demu, Dewi Retno Sari Saputro, Purnami Widyaningsih

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Human Development Index (HDI) is a standard measurement for a country's human development. Several factors may have influenced it, such as life expectancy, gross domestic product (GDP) based on the province's annual expenditure, the number of poor people, and the percentage of an illiterate people. The scatter plot between HDI and the influenced factors show that the plot does not follow a specific pattern or form. Therefore, the HDI's data in Indonesia can be applied with a nonparametric regression model. The estimation of the regression curve in the nonparametric regression model is flexible because it follows the shape of the data pattern. One of the nonparametric regression's method is a truncated spline. Truncated spline regression is one of the nonparametric approach, which is a modification of the segmented polynomial functions. The estimator of a truncated spline regression model was affected by the selection of the optimal knots point. Knot points is a focus point of spline truncated functions. The optimal knots point was determined by the minimum value of generalized cross validation (GCV). In this article were applied the data of Human Development Index with a truncated spline nonparametric regression model. The results of this research were obtained the best-truncated spline regression model to the HDI's data in Indonesia with the combination of optimal knots point 5-5-5-4. Life expectancy and the percentage of an illiterate people were the significant factors depend to the HDI in Indonesia. The coefficient of determination is 94.54%. This means the regression model is good enough to applied on the data of HDI in Indonesia.

Keywords: generalized cross validation (GCV), Human Development Index (HDI), knots point, nonparametric regression, truncated spline

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Authors: Anahita Mortazavi Manesh, Mojtaba Bagherzadeh

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Metalloporphyrins are well known to mimic the activity of monooxygenase enzymes. In this regard, metalloporphyrin complexes have been largely employed as valuable biomimetic catalysts, owing to the critical roles they play in oxygen transfer processes in catalytic oxidation reactions. Investigating in this area is based on different strategies to design selective, stable and high turnover catalytic systems. Immobilization of expensive metalloporphyrin catalysts onto supports appears to be a good way to improve their stability, selectivity and the catalytic performance because of the support environment and other advantages with respect to recovery, reuse. In other words, supporting metalloporphyrins provides a physical separation of active sites, thus minimizing catalyst self-destruction and dimerization of unhindered metalloporphyrins. Furthermore, heterogeneous catalytic oxidations have become an important target since their process are used in industry, helping to minimize the problems of industrial waste treatment. Hence, the immobilization of these biomimetic catalysts is much desired. An attractive approach is the preparation of the heterogeneous catalyst involves immobilization of complexes on silica coated magnetic nano-particles. Fe3O4@SiO2 magnetic nanoparticles have been studied extensively due to their superparamagnetism property, large surface area to volume ratio and easy functionalization. Using heterogenized homogeneous catalysts is an attractive option to facile separation of catalyst, simplified product work-up and continuity of catalytic system. Homogeneous catalysts immobilized on magnetic nanoparticles (MNPs) surface occupy a unique position due to combining the advantages of both homogeneous and heterogeneous catalysts. In addition, superparamagnetic nature of MNPs enable very simple separation of the immobilized catalysts from the reaction mixture using an external magnet. In the present work, an efficient heterogeneous catalyst was prepared by immobilizing manganese porphyrin on functionalized magnetic nanoparticles through the amino propyl linkage. The prepared catalyst was characterized by elemental analysis, FT-IR spectroscopy, X-ray powder diffraction, atomic absorption spectroscopy, UV-Vis spectroscopy, and scanning electron microscopy. Application of immobilized metalloporphyrin in the oxidation of various organic substrates was explored using Gas chromatographic (GC) analyses. The results showed that the supported Mn-porphyrin catalyst (Fe3O4@SiO2-NH2@MnPor) is an efficient and reusable catalyst in oxidation reactions. Our catalytic system exhibits high catalytic activity in terms of turnover number (TON) and reaction conditions. Leaching and recycling experiments revealed that nanocatalyst can be recovered several times without loss of activity and magnetic properties. The most important advantage of this heterogenized catalytic system is the simplicity of the catalyst separation in which the catalyst can be separated from the reaction mixture by applying a magnet. Furthermore, the separation and reuse of the magnetic Fe3O4 nanoparticles were very effective and economical.

Keywords: Fe3O4 nanoparticle, immobilized metalloporphyrin, magnetically separable nanocatalyst, oxidation reactions

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Authors: Hongyan Chen, Megan Jobson, Andrew J. Masters, Maria Gonzalez-Miquel, Simon Halstead, Mayri Diaz de Rienzo

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Ionic liquids offer excellent advantages over conventional solvents for industrial extraction of metals from aqueous solutions, where such extraction processes bring opportunities for recovery, reuse, and recycling of valuable resources and more sustainable production pathways. Recent research on the use of ionic liquids for extraction confirms their high selectivity and low volatility, but there is relatively little focus on how their properties can be best exploited in practice. This work addresses gaps in research on process modelling and simulation, to support development, design, and optimisation of these processes, focusing on the separation of the highly similar transition metals, cobalt, and nickel. The study exploits published experimental results, as well as new experimental results, relating to the separation of Co and Ni using trihexyl (tetradecyl) phosphonium chloride. This extraction agent is attractive because it is cheaper, more stable and less toxic than fluorinated hydrophobic ionic liquids. This process modelling work concerns selection and/or development of suitable models for the physical properties, distribution coefficients, for mass transfer phenomena, of the extractor unit and of the multi-stage extraction flowsheet. The distribution coefficient model for cobalt and HCl represents an anion exchange mechanism, supported by the literature and COSMO-RS calculations. Parameters of the distribution coefficient models are estimated by fitting the model to published experimental extraction equilibrium results. The mass transfer model applies Newman’s hard sphere model. Diffusion coefficients in the aqueous phase are obtained from the literature, while diffusion coefficients in the ionic liquid phase are fitted to dynamic experimental results. The mass transfer area is calculated from the surface to mean diameter of liquid droplets of the dispersed phase, estimated from the Weber number inside the extractor. New experiments measure the interfacial tension between the aqueous and ionic phases. The empirical models for predicting the density and viscosity of solutions under different metal loadings are also fitted to new experimental data. The extractor is modelled as a continuous stirred tank reactor with mass transfer between the two phases and perfect phase separation of the outlet flows. A multistage separation flowsheet simulation is set up to replicate a published experiment and compare model predictions with the experimental results. This simulation model is implemented in gPROMS software for dynamic process simulation. The results of single stage and multi-stage flowsheet simulations are shown to be in good agreement with the published experimental results. The estimated diffusion coefficient of cobalt in the ionic liquid phase is in reasonable agreement with published data for the diffusion coefficients of various metals in this ionic liquid. A sensitivity study with this simulation model demonstrates the usefulness of the models for process design. The simulation approach has potential to be extended to account for other metals, acids, and solvents for process development, design, and optimisation of extraction processes applying ionic liquids for metals separations, although a lack of experimental data is currently limiting the accuracy of models within the whole framework. Future work will focus on process development more generally and on extractive separation of rare earths using ionic liquids.

Keywords: distribution coefficient, mass transfer, COSMO-RS, flowsheet simulation, phosphonium

Procedia PDF Downloads 185

Authors: Savitri Siddanagoudra, Shantala Herlekar, Priya Arjunwadekar

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Background: The physiological response to water drinking in healthy subjects is an integrated response with an increase in sympathetic vasoconstrictor activity with induced bradycardia. Obesity is a modern pandemic, implicated in the pathogenesis of cardiovascular disease. In autonomic failure patients, water drinking has been shown the increased high blood pressure and bradycardia. Acute effects of ice water ingestion on blood pressure (BP) in relation to body mass index (BMI) is not addressed in literature. Objectives: Objective of this study is to evaluate BP before and after ingestion of cold water in all the three groups. Methods and Material: 60 healthy subjects between the age group of 18-24 yrs were selected and assigned into 3 groups based on BMI. BMI less than and equal to 25 kg/m2 is selected as Normal BMI group ,between 25- 29 kg/m2 as Overweight and BMI more than and equal to 30 kg/m2 as Obese. Procedure: Basal and after ingestion of 250 ml of cold water (7 0C ± 0.5 0C)BP was recorded in all the 3 groups. Results: Basal and after ice water ingestion BP increased statistically in all 3 groups. Conclusion: On acute ingestion of ice water overweight, obese may have more sympathoexcitaion compared to normal subjects.

Keywords: blood pressure, body mass index, ice water, symathoexcitation

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Authors: Naren Bag, S. Bhattacharyya, Partha P. Gopmandal

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In this study, we have analyzed the transport of analytes under a two dimensional steady incompressible flow of power-law fluids through rectangular nanochannel. A mathematical model based on the Cauchy momentum-Nernst-Planck-Poisson equations is considered to study the combined effect of mixed electroosmotic (EO) and pressure driven (PD) flow. The coupled governing equations are solved numerically by finite volume method. We have studied extensively the effect of key parameters, e.g., flow behavior index, concentration of the electrolyte, surface potential, imposed pressure gradient and imposed electric field strength on the net average flow across the channel. In addition to study the effect of mixed EOF and PD on the analyte distribution across the channel, we consider a nonlinear model based on general convective-diffusion-electromigration equation. We have also presented the retention factor for various values of electrolyte concentration and flow behavior index.

Keywords: electric double layer, finite volume method, flow behavior index, mixed electroosmotic/pressure driven flow, non-Newtonian power-law fluids, numerical simulation

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Authors: Etleva Hamzaraj, Eva Kica, Anila Paparisto, Pranvera Lazo

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Worldwide demographic developments of recent decades have been associated with negative environmental consequences. For this reason, there is a growing interest in assessing the state of natural ecosystems or assessing human impact on them. In this respect, this study aims to evaluate the change in water quality of the Mat River for a period of about ten years to highlight human impact. In one year, period of study, several biological and environmental parameters are determined to evaluate river water quality, and the data collected are compared with those of a similar study in 2007. Samples are collected every month in five stations evenly distributed along the river. Total coliform bacteria, the number of heterotrophic bacteria in water, and benthic macroinvertebrates are used as biological parameters of water quality. The most probable number index is used for evaluation of total coliform bacteria in water, while the number of heterotrophic bacteria is determined by counting colonies on plates with Plate Count Agar, cultivated with 0.1 ml sample after series dilutions. Benthic macroinvertebrates are analyzed by the number of individuals per taxa, the value of biotic index, EPT Richness Index value and tolerance value. Environmental parameters like pH, temperature, and electrical conductivity are measured onsite. As expected, the bacterial load was higher near urban areas, and the pollution increased with the course of the river. The maximum concentration of fecal coliforms was 1100 MPN/100 ml in summer and near the most urbanized area of the river. The data collected during this study show that after about ten years, there is a change in water quality of Mat River. According to a similar study carried out in 2007, the water of Mat River was of ‘excellent’ quality. But, according to this study, the water was classified as of ‘excellent’ quality only in one sampling site, near river source, while in all other stations was of ‘good’ quality. This result is based on biological and environmental parameters measured. The human impact on the quality of water of Mat River is more than evident.

Keywords: water quality, coliform bacteria, MPN index, benthic macroinvertebrates, biotic index

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Authors: Alper Serdar Anli

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Analysis of temporal variation of reference evapotranspiration (ET0) is important in arid and semi-arid regions where water resources are limited. In this study, temporal variation of reference evapotranspiration (ET0) and meteorological drought analysis through SPEI (Standardized Precipitation Evapotranspiration Index) method have been carried out in provinces of Central Anatolia Region, Turkey. Reference evapotranspiration of concerning provinces in the region has been estimated using Penman-Monteith method and one calendar year has been split up four periods as r1, r2, r3 and r4. Temporal variation of reference evapotranspiration according to four periods has been analyzed through parametric Dickey-Fuller test and non-parametric Mann-Whitney U test. As a result, significant increasing trends for reference evapotranspiration have been detected and according to SPEI method used for estimating meteorological drought in provinces, mild drought has been experienced in general, and however there have been also a significant amount of events where moderate and severely droughts occurred.

Keywords: central Anatolia region, drought index, Penman-Monteith, reference evapotranspiration, temporal variation

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Authors: Haïfa Ben Mna, Ayed Added

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To evaluate the trace metals contamination status in the Gulf of Tunis, forty one sediment samples were analyzed using different approaches. According to certain contamination and ecological risk indices (Contamination Factor, Geoaccumulation index and Ecological risk index), Hg has the highest contamination level while pollution by Ni, Pb, Cd and Cr was absent. The highest concentrations of trace metals were found in sediments collected from the offshore and coastal areas located opposite the main exchange points with the gulf particularly, the Mejerda and Meliane Rivers, the Khalij Channel, Ghar El Melh and El Malah lagoons, Tunis Lake and Sebkhat Ariana. However, further ecological indices (Potential ecological risk index, Toxic unit and Mean effect-range median quotient) and comparison with sediment quality guidelines suggest that in addition to Mercury, Cr, Pb and Ni concentrations are detrimental to biota in both the offshore and areas near to the exchange points with the gulf. Moreover, in these areas the results from sequential extraction and individual contamination factor calculation pointed to the mobility and bioavailability of Cr, Pb and Ni.

Keywords: sediment, trace metals, contamination assessment, ecological risk, Tunis gulf

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Authors: Mengying Wang, Xiaohui Wang, Chun Deng, Bei Liu, Changyu Sun, Guangjin Chen, Mahmoud El-Halwagi

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Significant amounts of natural gas hydrates (NGHs) are considered potential new sustainable energy resources in the future. However, common used methods for methane gas recovery from hydrate sediments require high investment but with low gas production efficiency, and may cause potential environment and security problems. Therefore, there is a need for effective gas production from hydrates. The natural gas hydrate production method by CO₂/H₂ replacement coupling steam methane reforming can improve the replacement effect and reduce the cost of gas separation. This paper develops a simulation model of the gas production process integrated with steam reforming and membrane separation. The process parameters (i.e., reactor temperature, pressure, H₂O/CH₄ ratio) and the composition of CO₂ and H₂ in the feed gas are analyzed. Energy analysis is also conducted. Two design scenarios with different composition of CO₂ and H₂ in the feed gas are proposed and evaluated to assess the energy efficiency of the novel system. Results show that when the composition of CO₂ in the feed gas is between 43 % and 72 %, there is a certain composition that can meet the requirement that the flow rate of recycled gas is equal to that of feed gas, so as to ensure that the subsequent production process does not need to add feed gas or discharge recycled gas. The energy efficiency of the CO₂ in feed gas at 43 % and 72 % is greater than 1, and the energy efficiency is relatively higher when the CO₂ mole fraction in feed gas is 72 %.

Keywords: Gas production, hydrate, process integration, steam reforming

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Authors: Saqib Saleem Abdullah, Saima Masood, Hafsa Zaneb, Shela Gul Bokhari, Muti Ur Rehman, Jamil Akbar

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A 5- weeks feeding trial was carried out to determine the effectiveness of Bacterial Phytase (Phyzyme®) in broilers, at different dietary levels of Phosphorous. 140 d-old broilers (Hubbard) were randomly divided into 4 groups (n=4). Birds were fed corn-based basal diet or the same diet supplemented with 3 different levels of non Phytate Phosphorous (NPP) (0.45 %, 0.30 % and 0.15 %). Furthermore, the diets were supplemented with bacterial Phytase. Birds were fed ad libitum and kept under thermo neutral conditions. The parameters studied were; body weight gain (BWG), tibial bone characteristics (TBC), serum Calcium (Ca), Phosphorus (P) and Alkaline Phosphatase (AP) levels and tibia ash percentage (TAP). BWG of the broilers was calculated at weekly interval and remaining parameters were calculated after slaughtering the birds at 35thday. Results suggested that Phytase supplementation at 0.30% NPP (Non Phytate Phosphorus + Bacterial Phytase) increased (P < 0.05) the BWG, bone length, bone weight, tibiotarsal index, medullary canal diameter and diaphysis diameter however, rubosticity index was reduced to minimum (P < 0.05) at this dietary level of phosphorous when compared with other groups. Maximum (P < 0.05) rubosticity index was observed in control group with 0% Phytase. Furthermore, Phytase addition at 0.30 % NPP also improved (P < 0.05) Ca, P and AP levels in the blood. Phytase supplementation at lower phosphorus level (0.30%NPP) improved BWG and TBC including bone density and bone quality in broilers hence it can be concluded that addition of Phytase at 0.30% NPP may prove beneficial for bone and overall performance in broilers.

Keywords: diaphysis diameter, phytase, rubosticity index, tibia

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Authors: Sungik Kang, Ja-Hoon Koo

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Globally, urban environments have become unequal, and cities have been segmented by income class. It is predicted that urban inequality has arisen by urban redevelopment and reconstruction projects that improve the urban environment and innovate cities. This study aims to analyze the occurrence and characteristics of urban inequality by using the housing price and sale price and demonstrating the correlation with the urban redevelopment project. This study measures 14 years of urban inequality index for 25 autonomous districts in Seoul and analyzes the correlation between urban inequality with urban redevelopment projects. As a conclusion of this study, first, the urban inequality index of Seoul has been continuously rising since 2015. Trends from 2006 to 2019 have been in U-curved shape in between 2015. In 2019, Seoul's urban inequality index was 0.420, a level similar to that of the 2007 financial crisis. Second, the correlation between urban redevelopment and urban inequality was not statistically significant. Therefore, we judged that urban redevelopment's scale or project structure has nothing with urban inequality. Third, while district designation of urban reconstruction temporarily alleviates urban inequality, the completion of the project increases urban inequality. When designating a district, urban inequality is likely to decrease due to decreased outdated housing transactions. However, the correlation with urban inequality increases as expensive houses has been placed after project completion.

Keywords: urban inequality, urban redevelopment projects, urban reconstruction projects, housing price inequality, panel analysis

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Authors: Marinela Istrate, Ionel Muntele, Alexandru Bănică

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The authors propose the identification, analysis and prognosis of the quantitative and qualitative evolution of the elderly population in the functional urban areas. The present paper takes into account the analysis of some representative indicators (the weight of the elderly population, ageing index, dynamic index of economic ageing of productive population etc.) and the elaboration of an integrated indicator that would help differentiate the population ageing forms in the 48 functional urban areas that were defined based on demographic and social-economic criteria for all large and medium cities in Romania.

Keywords: ageing, demographic transition, functional urban areas, spatial resilience

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Authors: Aditya Soni, Nimesh Parikh, R. A. Thakrar

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Background: A cross-sectional study looked to focus body image satisfaction, heretofore under investigated arena in our setting. This study additionally examined the relationship of body mass index, influence of media and self-esteem. Our second objective was to assess whether there was any relationship between body image dissatisfaction and gender. Methods: A cross-sectional study using body image satisfaction described in words was undertaken, which also explored relationship with body mass index (BMI), influence of media, self-esteem and other selected co-variables such as socio-demographic details, overall satisfaction in life, and particularly in academic/professional life, current health status using 5-item based Likert scale. Convenience sampling was used to select participants of both genders aged from 17 to 32 on a sample size of 303 participants. Results : The body image satisfaction had significant relationship with Body mass index (P<0.001), eating attitude (P<0.001), influence of media (P<0.001) and self-esteem (P<0.001). Students with low weight had a significantly higher prevalence of body image satisfaction while overweight students had a significantly higher prevalence of dissatisfaction (P<0.001). Females showed more concern about body image as compared to males. Conclusions: Generally, this study reveals that the eating attitude, influence of the media and self-esteem is significantly related to the body image. On an empowering note, this level needs to be saved for overall mental and sound advancement of people. Proactive preventive measures could be started in foundations on identity improvement, acknowledgement of self and individual contrasts while keeping up ideal weight and dynamic life style.

Keywords: body image, body mass index, media, self-esteem

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Authors: Shervin Alaei, Reza Moradi

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Trading in financial markets is subject to risks due to their high volatilities. Here, using an LSTM neural network, and by doing some risk-based feature engineering tasks, we developed a method that can accurately predict trends of the Tehran stock exchange market index from a few days ago. Our test results have shown that the proposed method with an average prediction accuracy of more than 94% is superior to the other common machine learning algorithms. To the best of our knowledge, this is the first work incorporating deep learning and risk factors to accurately predict market trends.

Keywords: deep learning, LSTM, trend prediction, risk management, artificial neural networks

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Authors: Ratna Farida Soenarto, Anas Alatas, Made Ryan Kharmayani

Abstract:

Background: Conventional ultrafiltration (CUF) system was shown to be helpful in reducing anti-inflammatory mediators for patients who underwent open heart surgery. Additionally, modified ultrafiltration (MUF) has been shown to reduce anti-inflammatory mediators further while reducing interstitial fluid volume at the same time. However, there has been minimal data concerning the efficacy of combining both ultrafiltration methods. This study aims to compare inflammation marker, vascular resistance, and cardiac index on CUF+MUF patients with CUF only patients undergoing open heart surgery. Method: This is a single blind randomized controlled trial on patients undergoing open heart surgery between June 2021 - October 2021 in CiptoMangunkusumo National Referral Hospital and Jakarta Heart Hospital. Patients wererandomized using block randomization into modified ultrafiltration following conventional ultrafiltration (CUF+MUF) and conventional ultrafiltration (CUF) only. Outcome assessed in this study were 24-hoursinterleukin-6 levels, systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), and cardiac index. Results: A total of 38patients were included (19 CUF+MUF and 19 CUF subjects). There was no difference in postoperative IL-6 level between groups (p > 0.05).No difference in PVR was observed between groups.Higher difference in SVR was observed in CUF+MUF group (-646 vs. -261dyn/s/cm-5, p < 0.05). Higher cardiac index was observed on CUF+MUF group (0.93 vs. 0.48, p < 0.05). Conclusion: Patients undergoing open heart surgery with modified ultrafiltration following conventional ultrafiltration had similar systemic inflammatory response and better cardiac response than those having conventional ultrafiltration.

Keywords: open-heart, CUF, MUF, SVR, PVR, IL-6

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Authors: Joanna Bielecka-Prus

Abstract:

In the view of increasing number of labour migrations associated with broadly understood economic crisis, many families experience migration separation. Currently, in the era of globalization, migration movements include an increasing number of families, more and more frequently a new type of family, a transnational family. Accordingly, the functions of the family, family practice of care, and the relationships between members of the group change especially in the case of female migration. Sociologists highlight the emotional aspects of migrants’ family lives: managing emotions, coping with guilt, loneliness and rejection. Not without significance is the fact that today's public discourse often represents migrant women in a negative light. On the one hand, consumption and expanding material resources are assessed positively, on the other hand, deficits emotional and devastation of family life in the transnational families appear. Opinions expressed by different environments: the media, the political environment, etc. do not always take into account the context of mobility and their different effects on family life. The paper will present the analysis of qualitative studies of Polish female migrants’ families left-behind (children, parents, caregivers N = 100) and their coping strategies in different situations in the event of migration separation. The main area of care deficit will be defined and it will be showed who and how help to solve the problems.

Keywords: care, children left behind, female migration, parents left behind

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Authors: Doo W. Lee, Soo J. Lee, Bye R. Yoon, Jae Y. Jho, Kyehan Rhee

Abstract:

Hand exoskeletons have been developed in order to assist daily activities for disabled and elder people. A figure exoskeleton was developed using ionic polymer metal composite (IPMC) actuators, and the performance of it was evaluated in this study. In order to study dynamic performance of a finger dummy performing pinching motion, force generating characteristics of an IPMC actuator and pinching motion of a thumb and index finger dummy actuated by IMPC actuators were analyzed. The blocking force of 1.54 N was achieved under 4 V of DC. A thumb and index finger dummy, which has one degree of freedom at the proximal joint of each figure, was manufactured by a three dimensional rapid prototyping. Each figure was actuated by an IPMC actuator, and the maximum fingertip force was 1.18 N. Pinching motion of a dummy was analyzed by two video cameras in vertical top and horizontal left end view planes. A figure dummy powered by IPMC actuators could perform flexion and extension motion of an index figure and a thumb.

Keywords: finger exoskeleton, ionic polymer metal composite, flexion and extension, motion analysis

Procedia PDF Downloads 232

Authors: Yazdani Saeed, Rafiei Hamed, Nekoofar Farahnaz

Abstract:

Governments Policies play a major role in national and international Markets. Pistachio is one of the most important non-oil export commodity of Iran. Therefore, in this study the relation between the producer support policies and the export of Pistachio was examined. An econometric model (VAR) was applied to test the study hypothesis. According to the estimated coefficient in VAR model, lag of producer support index has a significant and negative effect on variation of Pistachio’s export in short term. In other word, in short term, export advantage index is dependent on the amount of producers support in previous period.

Keywords: producer support, export advantage, pistachio, Iran

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Authors: Anton V. Bourdine, Vladimir A. Burdin, Oleg R. Delmukhametov

Abstract:

This work presents a fast and simple method for the design of large core silica optical fibers with differential mode delay (DMD) management. Some results are reported concerned with refractive index profile optimization for 42 µm core 16-LP-mode optical fiber for next-generation optical networks. Here special refractive index profile form provides total DMD reducing over all mode staff under desired enhanced mode effective area. Method for the simulation of 'real manufactured' few-mode optical fiber (FMF) core geometry differing from the desired optimized structure by core non-symmetrical ellipticity and refractive index profile deviation including local fluctuations is proposed. Results of the following analysis of optimized FMF with inserted geometry distortions performed by earlier on developed modification of rigorous mixed finite-element method showed strong DMD degradation that requires additional higher-order mode management. In addition, this work also presents a method for design mode division multiplexer channel precision spatial positioning scheme at FMF core end that provides one of the potentiality solutions of described DMD degradation problem concerned with 'distorted' core geometry due to features of optical fiber manufacturing techniques.

Keywords: differential mode delay, few-mode optical fibers, nonlinear Shannon limit, optical fiber non-circularity, ‘real manufactured’ optical fiber core geometry simulation, refractive index profile optimization

Procedia PDF Downloads 152

Authors: Yetunde I. Bulu, Moses B. Adewole, Julius O. Faluyi

Abstract:

This study investigates the effect of aggressive application of herbicide on weed succession in an urban environment in Ile-Ife, Osun State. An inspection of the communities was carried out to identify sites maintained by herbicides (test plots) and those without herbicide history (control plots). Four different experimental plots located at Olasode, Eleweran, Ife City and Parakin within Ile-Ife town were monitored during the study. Comprehensive enumeration and identification of plant populations to species level was carried out on each of the plots and at every visit to determine the direction of succession. Index of similarities was used to determine the relationship in plant species composition between plots treated with herbicide and the untreated plots. The trend of increasing plant species was observed in all the study plots. Low Similarity Index between the treated plots and the control vegetation was observed at all visitations. Low similarity was also observed between the above-ground vegetation and the seed bank in all the plots. The study concluded that the weed population observed from the experimental plots showed an increase in species richness and diversity when the plots were left to recover compared to the control plots.

Keywords: herbicide, index of similarity, population, soil seed bank, succession

Procedia PDF Downloads 156

Authors: Caleb B. Sagwa, Tobias O. Okeno, Alexander K. Kahi

Abstract:

Dairy cattle production plays an important role in the Kenyan economy. However, high incidences of mastitis is a major setback to the productivity in this industry. The current dairy cattle breeding objective in Kenya does not include mastitis resistance, mainly because the economic value of mastitis resistance has not been determined. Therefore this study aimed at estimating the economic value of mastitis resistance in dairy cattle in Kenya. Initial input parameters were obtained from literature on dairy cattle production systems in the tropics. Selection index methodology was used to derive the economic value of mastitis resistance. Somatic cell count (SCC) was used an indicator trait for mastitis resistance. The economic value was estimated relative to milk yield (MY). Economic values were assigned to SCC in a selection index such that the overall gain in the breeding goal trait was maximized. The option of estimating the economic value for SCC by equating the response in the trait of interest to its index response was considered. The economic value of mastitis resistance was US $23.64 while maximum response to selection for MY was US $66.01. The findings of this study provide vital information that is a pre-requisite for the inclusion of mastitis resistance in the current dairy cattle breeding goal in Kenya.

Keywords: somatic cell count, milk quality, payment system, breeding goal

Procedia PDF Downloads 254