Search results for: physico-chemical characteristics

Authors: Lucie Bielská, Lucia Škulcová, Martina Hvězdová, Jakub Hofman, Zdeněk Šimek

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The currently used pesticides represent a broad group of chemicals with various physicochemical and environmental properties which input has reached 2×106 tons/year and is expected to even increases. From that amount, only 1% directly interacts with the target organism while the rest represents a potential risk to the environment and human health. Despite being authorized and approved for field applications, the effects of pesticides in the environment can differ from the model scenarios due to the various pesticide-soil interactions and resulting modified fate and behavior. As such, a direct monitoring of pesticide residues and evaluation of their impact on soil biota, aquatic environment, food contamination, and human health should be performed to prevent environmental and economic damages. The present project focuses on fluvisols as they are intensively used in the agriculture but face to several environmental stressors. Fluvisols develop in the vicinity of rivers by the periodic settling of alluvial sediments and periodic interruptions to pedogenesis by flooding. As a result, fluvisols exhibit very high yields per area unit, are intensively used and loaded by pesticides. Regarding the floods, their regular contacts with surface water arise from serious concerns about the surface water contamination. In order to monitor pesticide residues and assess their environmental and biological impact within this project, 70 fluvisols were sampled over the Czech Republic and analyzed for the total and bioaccessible amounts of 40 various pesticides. For that purpose, methodologies for the pesticide extraction and analysis with liquid chromatography-mass spectrometry technique were developed and optimized. To assess the biological risks, both the earthworm bioaccumulation tests and various types of passive sampling techniques (XAD resin, Chemcatcher, and silicon rubber) were optimized and applied. These data on chemical analysis and bioavailability were combined with the results of soil analysis, including the measurement of basic physicochemical soil properties as well detailed characterization of soil organic matter with the advanced method of diffuse reflectance infrared spectrometry. The results provide unique data on the residual levels of pesticides in the Czech Republic and on the factors responsible for increased pesticide residue levels that should be included in the modeling of pesticide fate and effects.

Keywords: currently used pesticides, fluvisoils, bioavailability, Quechers, liquid-chromatography-mass spectrometry, soil properties, DRIFT analysis, pesticides

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Authors: Somayyeh Salari, Marziyeh Nayefi, Mohsen Sari, Mehdi Behgar

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This study was conducted to evaluate the effect of electron beam- irradiated cottonseed meal at a dose of 30 KGy on carcass characteristics and some blood parameters of broiler chicks. Various levels of cottonseed meal (CSM) (0, 12, and 24%, radiation and no radiation) were used with 5 dietary treatments, 4 replicates and 10 birds of each for 42 days in completely randomized design. At 42 d of age, two birds per pen were randomly selected for determination of carcass characteristics and blood parameters. Relative weights of liver, gastrointestinal tract (GI), pancreatic, gizzard and abdominal fat were increased with increasing levels of CSM in the diet (p<0/05). Glucose, cholesterol, HDL, triglyceride, and phosphorous concentrations increased and LDL concentration decreased as the dietary CSM levels increased (p<0/05). But radiation had not significant effect on blood parameters. Electron irradiation seems to be a good procedure to improve the nutritional quality of CSM but it seems higher dose of it was needed to improve blood parameters of chickens.

Keywords: blood parameters, carcass characteristics, cottonseed meal, electron beam

Procedia PDF Downloads 484

Authors: Reham Banwair, Lana Alshehri, Sara Hadrawi

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The purpose of this project is to identify user satisfaction with the AI functions on Snapchat, in order to generate improvement proposals that allow its development within the app. To achieve this, a qualitative analysis was carried out through interviews to people who usually use the application, revealing their satisfaction or dissatisfaction with the usefulness of the AI. In addition, the background of the company and its introduction in these algorithms were analyzed. Furthermore, the characteristics of the three main functions of AI were explained: identify songs, solve mathematical problems, and recognize plants. As a result, it was obtained that 50% still do not know the characteristics of AI, 50% still believe song recognition is not always correct, 41.7% believe that math problems are usually accurate and 91.7% believes the plant detection tool is working properly.

Keywords: artificial intelligence, scanning, Snapchat, machine learning

Procedia PDF Downloads 135

Authors: Rajasekhar Reddy Poonuru, Anusha Parnem

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Purpose: To formulate proliposome powder of agomelatine, an antipsychotic drug, and to evaluate physicochemical, in vitro characters and effect of surface charge on ex vivo intestinal permeation. Methods: Film deposition technique was employed to develop proliposomal powders of agomelatin with varying molar ratios of lipid Hydro Soy PC L-α-phosphatidylcholine (HSPC) and cholesterol with fixed sum of drug. With the aim to derive free flowing and stable proliposome powder, fluid retention potential of various carriers was examined. Liposome formation and number of vesicles formed for per mm3 up on hydration, vesicle size, and entrapment efficiency was assessed to deduce an optimized formulation. Sodium cholate added to optimized formulation to induce surface charge on formed vesicles. Solid-state characterization (FTIR, DSC, and XRD) was performed with the intention to assess native crystalline and chemical behavior of drug. The in vitro dissolution test of optimized formulation along with pure drug was evaluated to estimate dissolution efficiency (DE) and relative dissolution rate (RDR). Effective permeability co-efficient (Peff(rat)) in rat and enhancement ratio (ER) of drug from formulation and pure drug dispersion were calculated from ex vivo permeation studies in rat ileum. Results: Proliposomal powder formulated with equimolar ratio of HSPC and cholesterol ensued in higher no. of vesicles (3.95) with 90% drug entrapment up on hydration. Neusilin UFL2 was elected as carrier because of its high fluid retention potential (4.5) and good flow properties. Proliposome powder exhibited augmentation in DE (60.3 ±3.34) and RDR (21.2±01.02) of agomelation over pure drug. Solid state characterization studies demonstrated the transformation of native crystalline form of drug to amorphous and/or molecular state, which was in correlation with results obtained from in vitro dissolution test. The elevated Peff(rat) of 46.5×10-4 cm/sec and ER of 2.65 of drug from charge induced proliposome formulation with respect to pure drug dispersion was assessed from ex vivo intestinal permeation studies executed in ileum of wistar rats. Conclusion: Improved physicochemical characters and ex vivo intestinal permeation of drug from charge induced proliposome powder with Neusilin UFL2 unravels the potentiality of this system in enhancing oral delivery of agomelatin.

Keywords: agomelatin, proliposome, sodium cholate, neusilin

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Authors: Ahmed T. Farid, Khaled Z. Soliman

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Due to limited areas and excessive cost of land for projects, backfilling process has become necessary. Also, backfilling will be done to overcome the un-leveling depths or raising levels of site construction, especially near the sea region. Therefore, backfilling soil materials used under the foundation of structures should be investigated regarding its effect on ground motion characteristics, especially at regions subjected to earthquakes. In this research, 60-meter thickness of sandy fill material was used above a fixed 240-meter of natural clayey soil underlying by rock formation to predict the modified ground motion characteristics effect at the foundation level. Comparison between the effect of using three different situations of fill material compaction on the recorded earthquake is studied, i.e. peak ground acceleration, time history, and spectra acceleration values. The three different densities of the compacted fill material used in the study were very loose, medium dense and very dense sand deposits, respectively. Shake computer program was used to perform this study. Strong earthquake records, with Peak Ground Acceleration (PGA) of 0.35 g, were used in the analysis. It was found that, higher compaction of fill material thickness has a significant effect on eliminating the earthquake ground motion properties at surface layer of fill material, near foundation level. It is recommended to consider the fill material characteristics in the design of foundations subjected to seismic motions. Future studies should be analyzed for different fill and natural soil deposits for different seismic conditions.

Keywords: acceleration, backfill, earthquake, soil, PGA

Procedia PDF Downloads 381

Authors: Arya Pirooz

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The effects of different fuels (DME, RME B100, and SME B100) on barrel engines were studied as a general, single dimensional investigation for characterization of these types of engines. A base computational model was created as reference point to be used as a point of comparison with different cases. The models were computed using the commercial computational fluid dynamics program, Diesel-RK. The base model was created using basic dimensions of the PAMAR-3 engine with inline unit injectors. Four fuel cases were considered. Optimized models were also considered for diesel and DME cases with respect to injection duration, fuel, injection timing, exhaust and intake port opening, CR, angular offset. These factors were optimized for highest BMEP, combined PM and NOx emissions, and highest SFC. Results included mechanical efficiency (eta_m), efficiency and power, emission characteristics, combustion characteristics. DME proved to have the highest performing characteristics in relation to diesel and RME fuels for this type of barrel engine.

Keywords: DME, RME, Diesel-RK, characterization, inline unit injector

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Authors: R. Yulianingsih, S. Gohtani

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Characteristics of pregelatinized waxy rice starch (PWR) gelatinized at different temperatures (65, 75, and 85 °C, abbreviated as PWR 65, 75 and 85 respectively) and their emulsion-stabilizing properties at different starch concentrations (3, 5, 7, and 9%) were studied. The yield stress and consistency index value of PWR solution increased with an increase in starch concentration. The pseudoplasticity of PWR 65 solution increased and that for both PWR 75 and 85 solution decreased with an increase in starch concentration. Small angle X-ray scattering (SAXS) profiles analyzed by Kratky Plot indicated that PWR 65 is natively unfolded particles while PWR 75 and 85 are the globular particles. The characteristics of emulsions stabilized with PWR were influenced by the temperature of gelatinization process and starch concentration. Elevated concentration of starch decreased the value of yield stress and increased the consistency index. PWR 65 produce stable emulsion to creaming at starch concentrations more than 5%, while PWR 85 is able to produce stable emulsion to both creaming and coalescence of droplets.

Keywords: emulsion, gelatinization temperature, rheology, small-angle X-ray scattering, waxy rice starch

Procedia PDF Downloads 158

Authors: Teng-Chiu Lin, Pei-Jen Lee Shaner, Shin-Yu Lin

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Both forest age and physical damages due to weather events such as tropical cyclones can influence forest characteristics and subsequently its capacity to sequester carbon. Detangling these influences is therefore a pressing issue under climate change. In this study, we compared the compositional and structural characteristics of three forests in Taiwan differing in age and severity of typhoon disturbances. We found that the two forests (one old-growth forest and one secondary forest) experiencing more severe typhoon disturbances had shorter stature, higher wood density, higher tree species diversity, and lower typhoon-induced tree mortality than the other secondary forest experiencing less severe typhoon disturbances. On the other hand, the old-growth forest had a larger amount of woody debris than the two secondary forests, suggesting a dominant role of forest age on woody debris accumulation. Of the three forests, only the two experiencing more severe typhoon disturbances formed new gaps following two 2015 typhoons, and between these two forests, the secondary forest gained more gaps than the old-growth forest. Consider that older forests generally have more gaps due to a higher background tree mortality, our findings suggest that the age effects on gap dynamics may be reversed by typhoon disturbances. This study demonstrated the effects of typhoons on forest characteristics, some of which could negate the age effects and rejuvenate older forests. If cyclone disturbances were to intensity under climate change, the capacity of older forests to sequester carbon may be reduced.

Keywords: typhoon, canpy gap, coarse woody debris, forest stature, forest age

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Authors: Bulcha Belay Etana

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Research shows that several challenges are to be resolved for textile sensors and wearable smart textiles systems to make it accurate and reproducible minimizing variability issues when tested. To achieve this, we developed stimulating embroidery electrode with three different filling textiles such as 3Dknit, microfiber, and nonwoven fabric, and tested with FTT for high recoverability on compression. Hence The impedance characteristics of wetted electrodes were caried out after 1hr of wetting under normal environmental conditions. The wetted 3D knit (W-3D knit), Wetted nonwoven (W-nonwoven), and wetted microfiber (W-microfiber) developed using Satin stitch performed better than a dry standard stitch or dry Satin stitch electrodes. Its performance was almost the same as that of the gel electrode (Ag/AgCl) as shown by the impedance result in figure 2 .The impedance characteristics of Dry and wetted 3D knit based Embroidered electrodes are better than that of the microfiber, and nonwoven filling textile. This is due to the fact that 3D knit fabric has high recoverability on compression to retain electrolyte gel than microfiber, and nonwoven. However,The non-woven fabric held the electrolyte for longer time without releasing it to the skin when needed, thus making its impedance characteristics poor as observed from the results. Whereas the dry Satin stitch performs better than the standard stitch based developed electrode. The inter electrode distance of all types of the electrode was 25mm, with the area of the electrode being 20mm by 20mm. Detail evaluation and further analysis is in progress for EMG monitoring application

Keywords: impedance, moisture retention, 3D knit fabric, microfiber, nonwoven

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Authors: Yasaman Tohidi, Rouzbeh Riazi, Shidvash Vakilipour, Masoud Mohammadi

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The objective of the present study is to numerically investigate the effect of CO₂ replacement of N₂ in air stream on the flame characteristics of the CH₄ turbulent diffusion flame. The Open source Field Operation and Manipulation (OpenFOAM) has been used as the computational tool. In this regard, laminar flamelet and modified k-ε models have been utilized as combustion and turbulence models, respectively. Results reveal that the presence of CO₂ in air stream changes the flame shape and maximum flame temperature. Also, CO₂ dilution causes an increment in CO mass fraction.

Keywords: CH4 diffusion flame, CO2 dilution, OpenFOAM, turbulent flame

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Authors: B. Roopa Sri, Y Lakshmi Naidu

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Chemical Graph Theory (CGT) is the branch of mathematical chemistry in which molecules are modeled to study their physicochemical properties using molecular descriptors. Amongst these descriptors, topological indices play a vital role in predicting the properties by defining the graph topology of the molecule. Recently, the bond-additive topological index known as the Mostar index has been proposed. In this paper, we compute the Mostar-type indices of octane isomers and use the data obtained to perform QSPR analysis. Furthermore, we show the correlation between the Mostar type indices and the properties.

Keywords: chemical graph theory, mostar type indices, octane isomers, qspr analysis, topological index

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Authors: Zhuang Guo

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In the field of GaN-based resonant tunneling diodes (RTDs) simulations, the traditional Tsu-Esaki formalism failed to predict the values of peak currents and peak voltages in the simulated current-voltage(J-V) characteristics. The main reason is that due to the strong internal polarization fields, two-dimensional electron gas(2DEG) accumulates at emitters, resulting in 2D-2D resonant tunneling currents, which become the dominant parts of the total J-V characteristics. By comparison, based on the 3D-2D resonant tunneling mechanism, the traditional Tsu-Esaki formalism cannot predict the J-V characteristics correctly. To overcome this shortcoming, we develop a new analytical model for the 2D-2D resonant tunneling currents generated in GaN-based RTDs. Compared with Tsu-Esaki formalism, the new model has made the following modifications: Firstly, considering the Heisenberg uncertainty, the new model corrects the expression of the density of states around the 2DEG eigenenergy levels at emitters so that it could predict the half width at half-maximum(HWHM) of resonant tunneling currents; Secondly, taking into account the effect of bias on wave vectors on the collectors, the new model modifies the expression of the transmission coefficients which could help to get the values of peak currents closer to the experiment data compared with Tsu-Esaki formalism. The new analytical model successfully predicts the J-V characteristics of GaN-based RTDs, and it also reveals more detailed mechanisms of resonant tunneling happened in GaN-based RTDs, which helps to design and fabricate high-performance GaN RTDs.

Keywords: GaN-based resonant tunneling diodes, tsu-esaki formalism, 2D-2D resonant tunneling, heisenberg uncertainty

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Authors: Sun Jin Park, Kyung-Ja Cho

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This study focused on characteristics related to hasty behaviour. To investigate the relation between personal characteristics and hasty behaviour, 601 data were collected, 335 males and 256 females answered their own 'social avoidance and distress’, ‘anxiety’, ‘sensation seeking', 'hope', and ' hasty behaviour. And then 591 data were used for the analysis. The factor analysis resulted hasty behaviour consisted of 5 factors, time pressure, isolation, uncomfortable situation, boring condition, and expectation of reward. The result showed anxiety, sensation seeking, and hope related to hasty behaviour. Specifically, anxiety was involved in every hasty behaviour. This result means that psychological tension and worry are related to hasty behaviour in common. 'Social avoidance and distress', 'sensation seeking' and 'hope' influenced on hasty behaviour under time pressure, in isolation, in expectation of rewards respectively. This means that each factor of hasty behaviour has anxiety as its basis, expressed through a varied nature.

Keywords: hasty behaviour, social avoidance and distress, anxiety, sensation seeking, hope

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Authors: Joshua Chima Chizoba, Wisdom Izuchukwu Uzoma, Elizabeth Ifeyiwa Okoyeh

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Water cannot be optimally used and sustained unless the quality is periodically assessed. The study area Umunneochi and environs are located in south eastern part of Nigeria. It stretches geographically from latitudes 50501N to 60000N and longitudes 70201E to 70301. The major geologic formations in the area include the Asu River group, Nkporo Shale, and Ajali Sandstone. The aim of this study is to evaluate the hydrochemical characteristics of surface and ground water sources in parts of Umunneochi and environs in order to establish portability of the water sources for drinking, domestic and irrigation purposes. A total of 15 samples were collected randomly from streams, springs and wells. The samples were analyzed for physicochemical parameters and heavy metals using handheld digital kits, photometer, titration method and Atomic Absorption Spectrophotometer (AAS) following acceptable standards. The obtained analytical data were interpreted, and results were compared with World Health Organization (WHO) standard. The concentration of pH, SO42-and Cl- range from 5.81 mg/l – 6.07 mg/l, 41.93 mg/l – 142.95 mg/l and 20.00 mg/l – 111 mg/l respectively, while Pb and Zn revealed a relative low mean concentration of 0.14 mg/l and 0.40 mg/l, which are all within (WHO) permissible limits except pH. About 27% of the samples are moderately hard. This is attributed to the mining activities in the areas. The abundance of cations and anions in the area are in the order of K+>Na+>Mg2+>Ca2+ and SO4->Cl->HCO3->NO3-, respectively. Chloride, bicarbonate, and nitrate are all within the permissible limits. 13.33% of the total samples contain Sulphate above the standard permissible limits. The values of calculated Water Quality Index (WQI) are less than 50 indicating excellent water. The predominant water-type in the study area is Na-Cl water type and mixed Ca-Mg-Cl water type based on the sample plots on the Piper diagram. The Sodium Absorption Ratio (SAR) calculations showed excellent water for consumption and also good water for irrigation purpose with low sodium and alkalinity ratio respectively. Government water projects are recommended in the area for sustainable domestic and agricultural water supply to ease the stress of water supply problems.

Keywords: groundwater, hydrochemical, physichochemical, water-type, sodium adsorption ratio

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Authors: Nikhil Agrawal, Adam A. Skelton

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Alzheimer’s disease (AD) is one of the most common forms of dementia, which is caused by misfolding and aggregation of amyloid beta (Aβ) peptides into amyloid-β fibrils (Aβ fibrils). To disrupt the remodeling of Aβ fibrils, a number of candidate molecules have been proposed. To study the molecular mechanisms of Aβ fibrils remodeling we performed a series of all-atom molecular dynamics simulations, a total time of 3µs, in explicit solvent. Several previously undiscovered candidate molecule-Aβ fibrils binding modes are unraveled; one of which shows the direct conformational change of the Aβ fibril by understanding the physicochemical factors responsible for binding and subsequent remodeling of Aβ fibrils by the candidate molecule, open avenues into structure-based drug design for AD can be opened.

Keywords: alzheimer’s disease, amyloid, MD simulations, misfolded protein

Procedia PDF Downloads 347

Authors: Kamel Cheriet

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In Algeria, Opuntia ficus Indica production is important. This seasonal fruit is a characteristic of arid and semi-arid regions. Taking into account its high content in antioxidants, it has an excellent nutritional value. The aim of this research is the prickly pear morphological and physicochemical characterization study which is widely present in the Arris (Batna, Algeria) area. The results of this experimental study are comparative to those of the same species from other world regions. The whole fruit weight is estimated to reach 63.38 g with a juice ratio of 71.42%, a pH of 5.54, moisture of 89.3% and a brix of 10.4°. The quantitative amount of the phenolic compounds of the fruit revealed contents of 20.65-45.70 mg / 100 g of MF for total polyphenols and 0.519 -0.591 mg / 100 g of MF for the flavonoids.

Keywords: functional composition, nutritionals properties, opuntia ficus indica, phenolic compounds

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Authors: Alireza Rezagholilou

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Moisture susceptibility of bituminous mixes directly affect the stripping of asphalt layers. The majority of relevant test methods are mechanical methods with low repeatability and consistency of results. Thus, this research aims to evaluate the physicochemical interactions of bitumen and aggregates based on the wettability concept. As such, the surface energies of components at the interface are measured by contact angle method. That gives an opportunity to investigate the adhesion properties of multiple mineral fillers at various percentages to explore the best dosage in the mix. Three types of fillers, such as hydrated lime, ground lime and rock powder, are incorporated into the bitumen mix for a series of sessile drop tests for both aggregates and binders. Results show the variation of adhesion properties versus filler (%).

Keywords: adhesion, contact angle, filler, surface energy, moisture susceptibility

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Authors: Mohsen Amiri

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This study aimed at investigating the relationship between familial functioning, child characteristics, demographic variables and parenting stress and mental health among parents of children with mental disabilities. 200 parents (130 mothers and 70 fathers) were studied and they completed the Parenting Stress Index, General Health Questionnaire, Family Assessment Device and demographic questionnaires for parents and children. Data were analyzed using correlation and regression analysis. Regression analysis showed that child characteristics, familial functioning and parents demographic factors could predict 8, 4 and 17 percent of variance in parental stress and 3.6, 16 and 10 percent of variance in mental health, respectively. Familial functioning, child characteristics and parental demographic variables correlated with mental health and parental stress and could predict them.

Keywords: parenting stress, mental health, mentally disabled children, familial functioning, demographic variables

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Authors: Himanshu Dehra

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An experimental study was conducted for ascertaining electrical and thermal characteristics of a pair of photovoltaic (PV) modules integrated with solar wall of an outdoor room. A pre-fabricated outdoor room was setup for conducting outdoor experiments on a PV solar wall with passive and active ventilation through the outdoor room. The selective operating conditions for glass coated PV modules were utilized for establishing their electrical and thermal characteristics. The PV solar wall was made up of glass coated PV modules, a ventilated air column, and an insulating layer of polystyrene filled plywood board. The measurements collected were currents, voltages, electric power, air velocities, temperatures, solar intensities, and thermal time constant. The results have demonstrated that: i) a PV solar wall installed on a wooden frame was of more heat generating capacity in comparison to a window glass or a standalone PV module; ii) generation of electric power was affected with operation of vertical PV solar wall; iii) electrical and thermal characteristics were not significantly affected by heat and thermal storage losses; and iv) combined heat and electricity generation were function of volume of thermal and electrical resistances developed across PV solar wall. Finally, a comparison of temperature plots of passive and active ventilation envisaged that fan pressure was necessary to avoid overheating of the PV solar wall. The active ventilation was necessary to avoid over-heating of the PV solar wall and to maintain adequate ventilation of room under mild climate conditions.

Keywords: photovoltaic solar wall, solar energy, passive ventilation, active ventilation

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Authors: Wided Khiari, Adel Karaa

Abstract:

This study aims to establish a typology of Tunisian listed firms according to their corporate governance characteristics and disclosure quality. The paper uses disclosed scores to examine corporate governance practices of Tunisian listed firms. A content analysis of 46 Tunisian listed firms from 2001 to 2010 has been carried out and a disclosure index developed to determine the level of disclosure of the companies. The disclosure quality is appreciated through the quantity and also through the nature (type) of information disclosed. Applying the decision tree method, the obtained tree diagrams provide ways to know the characteristics of a particular firm regardless of its level of disclosure. Obtained results show that the characteristics of corporate governance to achieve good quality of disclosure are not unique for all firms. These structures are not necessarily all of the recommendations of best practices, but converge towards the best combination. Indeed, in practice, there are companies which have a good quality of disclosure, but are not well-governed. However, we hope that by improving their governance system their level of disclosure may be better. These findings show, in a general way, a convergence towards the standards of corporate governance with a few exceptions related to the specificity of Tunisian listed firms and show the need for the adoption of a code for each context. These findings shed the light on corporate governance features that enhance incentives for good disclosure. It allows identifying, for each firm and in any date, corporate governance determinants of disclosure quality. More specifically, and all being equal, obtained tree makes a rule of decision for the company to know the level of disclosure based on certain characteristics of the governance strategy adopted by the latter.

Keywords: corporate governance, disclosure, decision tree, economics

Procedia PDF Downloads 336

Authors: Ali W. N. Alattabi, Clare B. Harris, Rafid M. Alkhaddar, Montserrat Ortoneda, David A. Phipps, Ali Alzeyadi, Khalid S. Hashim

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This study was performed to optimise the hydraulic retention time (HRT) and study its effects on the sludge characteristics and the effluent quality in an aerobic suspension sequencing batch reactor (ASSBR) treating synthetic wastewater. The results showed that increasing the HRT from 6 h to 12 h significantly improved the COD and Nitrate removal efficiency; it was increased from 78.7% - 75.7% to 94.7% – 97% for COD and Nitrate respectively. However, increasing the HRT from 12 h to 18 h reduced the COD and Nitrate removal efficiency from 94.7% - 97% to 91.1% – 94.4% respectively. Moreover, Increasing the HRT from 18 h to 24 h did not affect the COD and Nitrate removal efficiency. Sludge volume index (SVI) was used to monitor the sludge settling performance. The results showed a direct relationship between the HRT and SVI value. Increasing the HRT from 6 h to 12 h led to decrease the SVI value from 123 ml/g to 82.5 ml/g, and then it remained constant despite of increasing the HRT from 12 h to 18 h and to 24 h. The results obtained from this study showed that the HRT of 12 h was better for COD and Nitrate removal and a good settling performance occurred during that range.

Keywords: COD, hydraulic retention time, nitrate, sequencing batch reactor, sludge characteristics

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Authors: Yan-Wen Wang, Chu-Yang Chou, Jen-Cheng Wang, Min-Sheng Liao, Hsuan-Hsiang Hsu, Cheng-Ying Chou, Chen-Kang Huang, Kun-Chang Kuo, Joe-Air Jiang

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Performance-related parameters of high concentration photovoltaic (HCPV) modules (e.g. current and voltage) are required when estimating the maximum power point using numerical and approximation methods. The maximum power point on the characteristic curve for a photovoltaic module varies when temperature or solar radiation is different. It is also difficult to estimate the output performance and maximum power point (MPP) due to the special characteristics of HCPV modules. Based on the p-n junction semiconductor theory, a brand new and simple method is presented in this study to directly evaluate the MPP of HCPV modules. The MPP of HCPV modules can be determined from an irradiated I-V characteristic curve, because there is a non-linear relationship between the temperature of a solar cell and solar radiation. Numerical simulations and field tests are conducted to examine the characteristics of HCPV modules during maximum output power tracking. The performance of the presented method is evaluated by examining the dependence of temperature and irradiation intensity on the MPP characteristics of HCPV modules. These results show that the presented method allows HCPV modules to achieve their maximum power and perform power tracking under various operation conditions. A 0.1% error is found between the estimated and the real maximum power point.

Keywords: energy performance, high concentrated photovoltaic, maximum power point, p-n junction semiconductor

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Authors: A.N. Moulay Khatir, A. Guen-Bouazza, B. Bouazza

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SOI-Multifin-FET shows excellent transistor characteristics, ideal sub-threshold swing, low drain induced barrier lowering (DIBL) without pocket implantation and negligible body bias dependency. In this work, we analyzed this combination by a three-dimensional numerical device simulator to investigate the influence of fins number on corner effect by analyzing its electrical characteristics and potential distribution in the oxide and the silicon in the section perpendicular to the flow of the current for SOI-single-fin FET, three-fin and five-fin, and we provide a comparison with a Trigate SOI Multi-FinFET structure.

Keywords: SOI, FinFET, corner effect, dual-gate, tri-gate, Multi-Fin FET

Procedia PDF Downloads 476

Authors: Djiazet Stève, Mezajoug Kenfack Laurette Blandine, Ravi Pullakhandam, Bethala L. A. Prabhavathi Devi, Tchiegang Clergé, Prathapkumar Halady Shetty

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The nutritional potential of a developed spice formulation for nah poh was evaluated. It was found that when spices were used for the formulation for nah poh, the concentration of some nutrients is diluted while that of some of them increases. The proportion of unsaturated fats was estimated to be 76.2% of the total fat content while the chemical score varied between 31 to 39%. The contents of some essential minerals of nutritional interest in mg are as follows for 100g of spice: 2372.474 ± 0.007 for potassium, 16.447 ± 0.010 for iron, 4.772 ± 0.005 for zinc, 0.537 ± 0.001 for cupper, 0.138 ± 0.005 for selenium, and 112.954 ± 0.003 for manganese. This study shows that the consumption of these spices in the form of formulation significantly contributes to meet the mineral requirements of the populations whose food habits regularly require these spices.

Keywords: spice formulation, characterisation, nutritional potential, nah poh, techno functional properties

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Authors: Henriette Scholtz

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Excessive executive directors’ remuneration remains a major concern for many stakeholders and are some of the factors to blame for the recent global financial crisis. The objective of this study was to examine whether certain firm characteristics are an effective way of protecting shareholders’ interests with respect to executive directors’ remuneration. To achieve this, an ordinary least squares model was used to test the relationship between the remuneration of executive directors and a number of firm and corporate governance characteristics to determine whether these characteristics have an influence on executive directors’ remuneration of large listed companies in South Africa. It was found that corporate governance reforms relating to institutional ownership, shareholder voting on the remuneration policy and the number of remuneration committee meetings acts as an effective governance tool to protect shareholder’s interests with regard to executive remuneration. There is no evidence that the number of non-executive directors on the remuneration committee has an influence on the executive directors’ remuneration.

Keywords: executive directors’ remuneration, agency theory, corporate governance, remuneration committee, directors’ shareholding, institutional ownership

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Authors: Charles Kwasi Antwi, Mohammad Naushad Emmambux, Natalia Rosa-Sibakov

Abstract:

The consumption of high-fibre snacks is beneficial in reducing the prevalence of most non-communicable diseases and improving human health. However, using high-fibre flour to produce snacks by extrusion cooking reduces the expansion ratio of snacks, thereby decreasing sensory properties and consumer acceptability of the snack. The study determines the effects of adding Viscozyme®-treated sorghum bran on the properties of extruded sorghum snacks with the aim of producing high-fibre expanded snacks with acceptable quality. With a twin-screw extruder, sorghum endosperm flour [by decortication] with and without sorghum bran and with enzyme-treated sorghum bran was extruded at high shear rates with feed moisture of 20%, feed rate of 10 kg/hr, screw speed of 500 rpm, and temperature zones of 60°C, 70°C, 80°C, 140°C, and 140°C toward the die. The expanded snacks that resulted from this process were analysed in terms of their physical (expansion ratio, bulk density, colour profile), chemical (soluble and insoluble dietary fibre), and functional (water solubility index (WSI) and water absorption index (WAI)) characteristics. The expanded snacks produced from refined sorghum flour enriched with Viscozyme-treated bran had similar expansion ratios to refined sorghum flour extrudates, which were higher than those for untreated bran-sorghum extrudate. Sorghum extrudates without bran showed higher values of expansion ratio and low values of bulk density compared to the untreated bran extrudates. The enzyme-treated fibre increased the expansion ratio significantly with low bulk density values compared to untreated bran. Compared to untreated bran extrudates, WSI values in enzyme-treated samples increased, while WAI values decreased. Enzyme treatment of bran reduced particle size and increased soluble dietary fibre to increase expansion. Lower particle size suggests less interference with bubble formation at the die. Viscozyme-treated bran-sorghum composite flour could be used as raw material to produce high-fibre expanded snacks with improved physicochemical and functional properties.

Keywords: extrusion, sorghum bran, decortication, expanded snacks

Procedia PDF Downloads 93

Authors: B. Moueddene, B. Labbaci, L. Missoum, R. Abdeldjebar

Abstract:

Quality estimation of the experimental simulation of boundary conditions is one of the problems encountered while performing an experimental program. In fact, it is not easy to estimate directly the effective influence of these simulations on the results of experimental investigation. The aim of this is article to evaluate the effect of boundary conditions uncertainties on structure response, using the change of the dynamics characteristics. The experimental models used and the correlation by the Frequency Domain Assurance Criterion (FDAC) allowed an interpretation of the change in the dynamic characteristics. The application of this strategy to stratified composite structures (glass/ polyester) has given satisfactory results.

Keywords: vibration, composite, endommagement, correlation

Procedia PDF Downloads 366

Authors: M. Stoklasa, H. Starzyczna, K. Matusinska

Abstract:

This article deals with the perceived quality of regional products in the Moravian-Silesian region in the Czech Republic. Research was focused on finding out what do consumers perceive as a quality product and what characteristics make a quality product. The data were obtained by questionnaire survey and analysed by IBM SPSS. From the thousands of respondents the representative sample of 719 for MS region was created based on demographic factors of gender, age, education and income. The research analysis disclosed that consumers in MS region are still price oriented and that the preference of quality over price does not depend on regional brand knowledge.

Keywords: regional brands, quality products, characteristics of quality, quality over price

Procedia PDF Downloads 418

Authors: Pruethipong Xinghatiraj, Rajwanlop Kumpoopong

Abstract:

Considering the current situation of road safety, Thailand has the world’s second-highest road fatality rate. Therefore, decreasing the road accidents in Thailand is a prime policy of the Thai government seeking to accomplish. One of the approaches to reduce the accident rate is to improve road environments to fit with the local behavior of the road users. The Department of Highways ensures that choosing the road median types right to the road characteristics, e.g. roadside characteristics, traffic volume, truck traffic percentage, etc., can decrease the possibility of accident occurrence. Presently, raised median, depressed median, painted median and median barriers are typically used in Thailand Highways. In this study, factors affecting road accident for each median type will be discovered through the analysis of the collecting of accident data, death numbers on sample of 600 Kilometers length across the country together with its roadside characteristics, traffic volume, heavy vehicles percentage, and other key factors. The benefits of this study can assist the Highway designers to select type of road medians that can match local environments and then cause less accident prone.

Keywords: highways, road safety, road median, forecasting model

Procedia PDF Downloads 269

Authors: Nady Farag Faragalla Hanna

Abstract:

In the car dealership industry in Japan, the sales specialist is a key factor in the success of the company. I hypothesize that when a company understands the characteristics of sales professionals in its industry, it is easier to recruit and train salespeople effectively. Lean human resources management ensures the economic success and performance of companies, especially small and medium-sized companies.The purpose of the article is to determine the characteristics of sales specialists for small and medium-sized car dealerships using the chi-square test and the proximate variable model. Accordingly, the results show that career change experience, learning ability and product knowledge are important, while university education, career building through internal transfer, leadership experience and people development are not important for becoming a sales professional. I also show that the characteristics of sales specialists are perseverance, humility, improvisation and passion for business.

Keywords: electronics engineering, marketing, sales, E-commerce digitalization, interactive systems, sales process ARIMA models, sales demand forecasting, time series, R codetraits of sales professionals, variable precision rough sets theory, sales professional, sales professionals

Procedia PDF Downloads 53