Search results for: effect of discharge
14061 Investigation of the Recycling of Geopolymer Cement Wastes as Fine Aggregates in Mortar Mixes
Authors: Napoleana-Anna Chaliasou, Andrew Heath, Kevin Paine
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Fly ash-slag based Geopolymer Cement (GPC) is presenting mechanical properties and environmental advantages that make it the predominant “green” alternative to Portland Cement (PC). Although numerous life-cycle analyses praising its environmental advantages, disposal after the end of its life remains as an issue that has been barely explored. The present study is investigating the recyclability of fly ash-slag GPC as aggregate in mortars. The purpose of the study was to evaluate the effect of GPC fine Recycled Aggregates (RA), at replacement levels of 25% and 50%, on the main mechanical properties of PC and GPC mortar mixes. The results were compared with those obtained by corresponding mixes incorporating natural and PC-RA. The main physical properties of GPC-RA were examined and proven to be comparable to those of PC-RA and slightly inferior to those of natural sand. A negligible effect was observed at 28-day compressive and flexural strength of PC mortars with GPC aggregates having a milder effect than PC. As far as GPC mortars are concerned, the influence of GPC aggregates was enhancing for the investigated mechanical properties. Additionally, a screening test showed that recycled geopolymer aggregates are not prone of inducing alkali silica reaction.Keywords: concrete recycling, geopolymer cement, fly ash, construction wastes
Procedia PDF Downloads 31814060 Cyclic Heating Effect on Hardness of Copper
Authors: Tahany W. Sadak
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Presented work discusses research results concerning the effect of the heat treatment process. Thermal fatigue which expresses repeated heating and cooling processes affect the ductility or the brittleness of the material. In this research, 70 specimens of copper (1.5 mm thickness, 85 mm length, 32 mm width) are subjected to thermal fatigue at different conditions. Heating temperatures Th are 100, 300 and 500 °C. Number of repeated cycles N is from 1 to 100. Heating time th =600 Sec, and Cooling time; tC= 900 Sec. Results are evaluated and then compared to each other and to that of specimens without subjected to thermal fatigue.Keywords: copper, thermal analysis, heat treatment, hardness, thermal fatigue
Procedia PDF Downloads 43414059 Effect of Sedimentation on Torque Transmission in the Larger Radius Magnetorheological Clutch
Authors: Manish Kumar Thakur, Chiranjit Sarkar
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Sedimentation of magnetorheological (MR) fluid affects its working. MR fluid is a smart fluid that has unique qualities such as quick responsiveness and easy controllability. It is used in the MR damper, MR brake, and MR clutch. In this work effect of sedimentation on torque transmission in the shear mode operated MR clutch is investigated. A test rig is developed to test the impact of sedimentation on torque transmission in the MR clutch. Torque transmission capability of MR clutch has been measured under two conditions to confirm the result of sedimentation. The first experiment is done just after filling and the other after one week. It has been observed that transmission torque is decreased after sedimentation. Hence sedimentation affects the working of the MR clutch.Keywords: clutch, magnetorheological fluid, sedimentation, torque
Procedia PDF Downloads 18414058 Investigation of Knitted Fabric Properties Effect on Evaporation Rate
Authors: N. S. Achour, M. Hamdaoui, S. Ben Nasrallah
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Evaporation kinetics of water from porous knitted fabrics are studied: An experimental study of determining evaporated water mass (g) versus time (s) from different knitted fabrics was gravimetrically investigated in various atmospheric conditions. Then evaporation rates are calculated. The goal is to determine the effect of fabric composition, knit structure and yarns properties on evaporation rate. The results show that fabrics geometrical properties, such as porosity and thickness, have a significant influence on evaporated water quantities.Keywords: evaporation rate, experimental study, geometrical properties, porous knitted fabrics
Procedia PDF Downloads 50314057 Stoner Impurity Model in Nickel Hydride
Authors: Andrea Leon, J. M. Florez, P. Vargas
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The effect of hydrogen adsorption on the magnetic properties of fcc Ni has been calculated using the linear-muffin-tin-orbital formalism and using the local-density approximation for the exchange y correlation. The calculations for the ground state show that the sequential addition of hydrogen atoms is found to monotonically reduce the total magnetic moment of the Ni fcc structure, as a result of changes in the exchange-splitting parameter and in the Fermi energy. In order to physically explain the effect of magnetization reduction as the Hydrogen concentration increases, we propose a Stoner impurity model to describe the influence of H impurity on the magnetic properties of Nickel.Keywords: electronic structure, magnetic properties, Nickel hydride, stoner model
Procedia PDF Downloads 45914056 Surface Engineering and Characterization of S-Phase Formed in AISI 304 By Low-Temperature Nitrocarburizing
Authors: Jeet Vijay Sah, Alphonsa Joseph, Pravin Kumari Dwivedi, Ghanshyam Jhala, Subroto Mukherjee
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AISI 304 is known for its corrosion resistance which comes from Cr that forms passive Cr₂O₃ on the surface. But its poor hardness makes it unsuitable for applications where the steel also requires high wear resistance. This can be improved by surface hardening using nitrocarburizing processes, which form ε-Fe2-3N, γ’-Fe4N, nitrides, and carbides of Cr and Fe on the surface and subsurface. These formed phases give the surface greater hardness, but the corrosion resistance drops because of the lack of Cr2O3 passivation as a result. To overcome this problem, plasma nitrocarburizing processes are being developed where the process temperatures are kept below 723 K to avoid Cr-N precipitation. In the presented work, low-temperature pulsed-DC plasma nitrocarburizing utilizing a discharge of N₂-H₂-C₂H₂ at 500 Pa with varying N₂:H₂ ratios was conducted on AISI 304 samples at 673 K. The process durations were also varied, and the samples were characterized by microindentation using Vicker’s hardness tester, corrosion resistances were established from electrochemical impedance studies, and corrosion potentials and corrosion currents were obtained by potentiodynamic polarization testing. XRD revealed S-phase, which is a supersaturated solid solution of N and C in the γ phase. The S-phase was observed to be composed of the expanded phases of γ; γN, γC, and γ’N and ε’N phases. Significant improvement in surface hardness was achieved after every process, which is attributed to the S-phase. Corrosion resistance was also found to improve after the processes. The samples were also characterized by XPS, SEM, and GDOES.Keywords: AISI 304, surface engineering, nitrocarburizing, S-phase
Procedia PDF Downloads 10614055 Mechanical Study Material on Low Environmental Impact
Authors: Fetta Ait Ahsene-Aissat, Messaoud Hachemi, Yacine Moussaoui, Yacine Kerchiche
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Our study focuses on two important aspects, environmental by using a sub industrial product (FAD), by economic incorporation as an addition to Portland cement, thus improving resistance to compression and bending with different proportions ADF % up to 40 additions. We studied the effect of different substitutions 0%, 10%, 20%, and 40% of additions to the mechanical effect of the mortar. We obtained a compressive strength of 61 MPa at 90 days for the cement mixture porthland FAD-40% against a resistance of 58MPa for porthland cement without addition. The flexural strength also showed a marked increase in the cement substitution. We also monitored the behavior of the mixed ash-cement by XRD analysis and scanning electron microscopy (SEM).Keywords: FAD, porthland, flexural strength, compressive strength, DRX
Procedia PDF Downloads 35214054 Farming Production in Brazil: Innovation and Land-Sparing Effect
Authors: Isabela Romanha de Alcantara, Jose Eustaquio Ribeiro Vieira Filho, Jose Garcia Gasques
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Innovation and technology can be determinant factors to ensure agricultural and sustainable growth, as well as productivity gains. Technical change has contributed considerably to supply agricultural expansion in Brazil. This agricultural growth could be achieved by incorporating more land or capital. If capital is the main source of agricultural growth, it is possible to increase production per unit of land. The objective of this paper is to estimate: 1) total factor productivity (TFP), which is measured in terms of the rate of output per unit of input; and 2) the land-saving effect (LSE) that is the amount of land required in the case that yield rate is constant over time. According to this study, from 1990 to 2019, it appears that 87 percent of Brazilian agriculture product growth comes from the gains of productivity; the rest of 13 percent comes from input growth. In the same period, the total LSE was roughly 400 Mha, which corresponds to 47 percent of the national territory. These effects reflect the greater efficiency of using productive factors, whose technical change has allowed an increase in agricultural production based on productivity gains.Keywords: agriculture, land-saving effect, livestock, productivity
Procedia PDF Downloads 23114053 The Effect of Online Self-Assessment Diaries on Academic Achievement
Authors: Zi Yan
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The pedagogical value of self-assessment is widely recognized. However, identifying effective methods to help students develop productive SA practices poses a significant challenge. Since most students do not acquire self-assessment skills intuitively, they need instruction and guidance. This study is a randomized controlled trial aiming to test the effect of online self-assessment diaries on students’ achievement scores compared to a control group. Two groups of secondary school students (N=59), recruited through convenience sampling, participated in the study. The two groups were randomly designated to one of two conditions: control (n = 31) and online self-assessment diary (n = 28). The participants completed a curriculum-specific pre-test and a baseline survey on the first week of the 10-week study, as well as completed a post-test and survey by the tenth week. The results showed that the SA diary intervention had a significantly positive effect on post-intervention language learning scores after controlling for baseline scores. The findings highlight the potential of self-assessment to enhance educational outcomes, emphasizing its significant implications for educational policies that promote the integration of SA strategies into pedagogical practices.Keywords: self-assessment, online diary, academic achievement, experimenal study
Procedia PDF Downloads 5214052 The Effect of Six Weeks Aerobic Training and Taxol Consumption on Interleukin 8 and Plasminogen Activator Inhibitor-1 on Mice with Cervical Cancer
Authors: Alireza Barari, Maryam Firoozi, Maryam Ebrahimzadeh, Romina Roohan Ardeshiri, Maryam Kamarloeei
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Background: The The purpose of this study was to evaluate the effect of six-week aerobic training and taxol consumption on interleukin 8 and Plasminogen Activator Inhibitor-1 (PAI-1) in mice with cervical cancer. Material and method: In this experimental study, 40 female C57 mice, eight weeks old, were randomly divided into 4 groups: cancer, cancer-taxol complement, cancer-training and cancer-training - taxol complement with 10 mice in each group. The implantation of cancerous tumors was performed under the skin of the upper pelvis. The training group completed the endurance training protocol, which included 3 sessions per week, 50 minutes per session, at a speed of 14-18 m/s for six weeks. A dose of 60 mg/ kg/day, a pure extract of Taxol was injected peritoneal Data were analyzed by t-test, One-way ANOVA and post hoc Bonferron's at the significant level P<0. 05. Results: The results showed that there was a significant difference between mean values of interleukin-8 (P < 0.05, F = 12.25) and the plasminogen activator inhibitor-1 (P < 0.05, P=0.10737) in four groups. A significance level of less than 0.05 in Tukey test for both variables also showed a significant difference between the "control" group and the complementary "exercise" group. Namely, six weeks of aerobic training, along with taxol, have a significant effect on the level of plasminogen activator inhibitor-1 and interleukin-8 mice with cervical cancer. Conclusion: Considering the effect of training on these variables, this type of exercise can be used as a complementary therapeutic approach along with other therapies for cervical cancer.Keywords: cervical cancer, taxol, endurance training, interleukin 8, plasminogen activator inhibitor-1
Procedia PDF Downloads 18314051 Nursing Experience of Providing Nursing Care to a Lung Transplantation Patient by Applying the Self-Efficacy Theory
Authors: Hsin-Yi Huang
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This study mainly discussed the disease-induced and surgery-induced physical, psychological, and spiritual issues faced by a patient who suffered from emphysema and respiratory failure and had underwent a right-lung transplantation surgery. Nursing care was provided from May 21 to May 29. Based on the observations, interviews, physical examinations, and evaluations that were carried out using Roy’s adaptation model, the following nursing issues were identified: risk of infection, lack of knowledge, and anxiety. Active care was provided and a good nursing relationship with the patient and the patient’s family was established. The four strategies of Bandura’s self-efficacy theory (self-transcendence, vicarious experience, verbal persuasion, and biofeedback) were employed. Instructions for the appropriate rehabilitation exercises were given, immunosuppressant concentration was monitored, and special measures were taken to prevent infection. The patient was encouraged to express feelings and was provided with sufficient information to alleviate anxiety. With assistance from nursing personnel and the medical team, the patient was successfully discharged from the hospital and thereafter embarked on the path of postoperative recovery. The patient learned about the importance of home self-care and regular follow-up outpatient visits, and patient management was implemented for discharge preparation services. This nursing case study may serve as a reference to nurses managing similar cases in future.Keywords: anxiety, lung transplantation, Roy's adaptation model, self-efficacy theory
Procedia PDF Downloads 15214050 Taguchi-Based Optimization of Surface Roughness and Dimensional Accuracy in Wire EDM Process with S7 Heat Treated Steel
Authors: Joseph C. Chen, Joshua Cox
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This research focuses on the use of the Taguchi method to reduce the surface roughness and improve dimensional accuracy of parts machined by Wire Electrical Discharge Machining (EDM) with S7 heat treated steel material. Due to its high impact toughness, the material is a candidate for a wide variety of tooling applications which require high precision in dimension and desired surface roughness. This paper demonstrates that Taguchi Parameter Design methodology is able to optimize both dimensioning and surface roughness successfully by investigating seven wire-EDM controllable parameters: pulse on time (ON), pulse off time (OFF), servo voltage (SV), voltage (V), servo feed (SF), wire tension (WT), and wire speed (WS). The temperature of the water in the Wire EDM process is investigated as the noise factor in this research. Experimental design and analysis based on L18 Taguchi orthogonal arrays are conducted. This paper demonstrates that the Taguchi-based system enables the wire EDM process to produce (1) high precision parts with an average of 0.6601 inches dimension, while the desired dimension is 0.6600 inches; and (2) surface roughness of 1.7322 microns which is significantly improved from 2.8160 microns.Keywords: Taguchi Parameter Design, surface roughness, Wire EDM, dimensional accuracy
Procedia PDF Downloads 37114049 Effects of Plasma Treatment on Seed Germination
Authors: Yong Ho Jeon, Youn Mi Lee, Yong Yoon Lee
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Effects of cold plasma treatment on various plant seed germination were studied. The seeds of hot pepper, cucumber, tomato and arabidopsis were exposed to plasma and the plasma was generated in various devices. The germination speed was evaluated compared to an unexposed control. A positive effect on germination speed was observed in all tested seeds but the effects strongly depended on the type of the used plasma device (Argon-DBD, surface-DBD or MARX generator), time of exposure (6s~10min or 1~10shots) and kind of seeds. The SEM images showed that arrays of gold particles along the cell wall were observed on the surface of cucumber seeds showed a germination-accelerating effect by plasma treatment, which was the same as untreated. However, when treated with the high dose plasma, gold particles were not arrayed at the seed surface, it seems that due to the surface etching. This may suggest that the germination is not promoted by etching or damage of surface caused by the plasma treatment. Seedling growth improvement was also observed by indirect plasma treatment. These lead to an important conclusion that the effect of charged particles on plasma play the essential role in plant germination and indirect plasma treatment offers new perspectives for large scale application.Keywords: cold plasma, cucumber, germination, SEM
Procedia PDF Downloads 31514048 Corporate Governance and Audit Report Lag: The Case of Tunisian Listed Companies
Authors: Lajmi Azhaar, Yab Mdallelah
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This study examines the Tunisian market in which recent events, notably financial scandals, provide an appropriate framework for studying the impact of corporate governance on the audit report lag. Moreover, very little research has been done to examine this relationship in this context. The objective of this work is, therefore, to understand the factors influencing audit report lag, drawing primarily on agency theory (Jensen and Meckling, 1976), which shows that the characteristics of the board of directors have an impact on the report lag (independence, diligence, and size). In addition, the characteristics of the committee also have an impact on the audit report lag (size, independence, diligence, and expertise). Therefore, our research provides empirical evidence on the impact of governance mechanisms attributes on audit report lag. Using a sample of forty-seven (47) Tunisian companies listed on the Tunis Stock Exchange (BVMT) during the period from 2014 to 2019, and basing on the GMM method of the dynamic panel, multivariate analysis shows that most corporate governance attributes have a significant effect on audit report lag. Specifically, the audit committee diligence and the audit committee expertise have a significant and positive effect on audit report lag. But the diligence of the board has a significant and negative effect on audit report lag. However, this study finds no evidence that the audit committee independence, the size, independence, and diligence of the director’s board are associated with the audit report lag. In addition, the results of this study also show that there is a significant effect of some control variables. Finally, we are contributing to this study by using the GMM method of the dynamic panel. We are also using an emerging context that is very poorly developed and exploited by previous studies.Keywords: governance mechanisms, audit committee, board of directors, audit report lag
Procedia PDF Downloads 17414047 Combinated Effect of Cadmium and Municipal Solid Waste Compost Addition on Physicochemical and Biochemical Proprieties of Soil and Lolium Perenne Production
Authors: Sonia Mbarki Marian Brestic, Artemio Cerda Naceur Jedidi, Jose Antonnio Pascual Chedly Abdelly
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Monitoring the effect addition bio-amendment as compost to an agricultural soil for growing plant lolium perenne irrigated with a CdCl2 solution at 50 µM on physicochemical soils characteristics and plant production in laboratory condition. Even microbial activity indexes (acid phosphatase, β-glucosidase, urease, and dehydrogenase) was determined. Basal respiration was the most affected index, while enzymatic activities and microbial biomass showed a decrease due to the cadmium treatments. We noticed that this clay soil with higher pH showed inhibition of basal respiration. Our results provide evidence for the importance of ameliorating effect compost on plant growth even when soil was added with cadmium solution at 50 µmoml.l-1. Soil heavy metal concentrations depended on heavy metals types, increased substantially with cadmium increase and with compost addition, but the recorded values were below the toxicity limits in soils and plants except for cadmium.Keywords: compost, enzymatic activity, lolium perenne, bioremediation
Procedia PDF Downloads 37814046 Investigation of the Speckle Pattern Effect for Displacement Assessments by Digital Image Correlation
Authors: Salim Çalışkan, Hakan Akyüz
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Digital image correlation has been accustomed as a versatile and efficient method for measuring displacements on the article surfaces by comparing reference subsets in undeformed images with the define target subset in the distorted image. The theoretical model points out that the accuracy of the digital image correlation displacement data can be exactly anticipated based on the divergence of the image noise and the sum of the squares of the subset intensity gradients. The digital image correlation procedure locates each subset of the original image in the distorted image. The software then determines the displacement values of the centers of the subassemblies, providing the complete displacement measures. In this paper, the effect of the speckle distribution and its effect on displacements measured out plane displacement data as a function of the size of the subset was investigated. Nine groups of speckle patterns were used in this study: samples are sprayed randomly by pre-manufactured patterns of three different hole diameters, each with three coverage ratios, on a computer numerical control punch press. The resulting displacement values, referenced at the center of the subset, are evaluated based on the average of the displacements of the pixel’s interior the subset.Keywords: digital image correlation, speckle pattern, experimental mechanics, tensile test, aluminum alloy
Procedia PDF Downloads 7414045 Allelopathic Effects of Eucalyptus camaldulensis and E. gomphocephala on Seed Germination and Seedling Growth of Barley
Authors: Sallah S. El-Ammari, Mona. S. Hasan
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This research is aimed to study allelopathic effects of two wind breakers Eucalyptus camaldulensis and E.gomphocephala on germination and growth of barley using aqueous extracts of leaves at 0.5, 1, 5, and 10% concentrations for treatment of barley caryopsis in petri dishes incubated in growth chamber. Distilled water was used in the experiment as a control. Seed germination was recorded on daily basis for five days. After ten days measurements of root length, shoot length, fresh and dry weight of root and shoot were taken. With the exception of 0.5% E. gomphocephala extract effect on length and dry weight of barley root, all the tested extract concentrations for both eucalyptus species significantly decreased the percent and speed of germination, root and shoot length, fresh and dry weight of root and shoot of barley compared to the control. For both species the allelopathic effect was significantly increasing with the increase of the extract concentration. Although, higher allelopathic effect was shown by E. camaldulensis, the results indicating that both eucalyptus species should not be recommended as wind breakers for barley fields.Keywords: allelopathy, eucalyptus, barley, Libya
Procedia PDF Downloads 34814044 Procyclicality of Leverage: An Empirical Analysis from Turkish Banks
Authors: Emin Avcı, Çiydem Çatak
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The recent economic crisis have shown that procyclicality, which could threaten the stability and growth of the economy, is a major problem of financial and real sector. The term procyclicality refers here the cyclical behavior of banks that lead them to follow the same patterns as the real economy. In this study, leverage which demonstrate how a bank manage its debt, is chosen as bank specific variable to see the effect of changes in it over the economic cycle. The procyclical behavior of Turkish banking sector (commercial, participation, development-investment banks) is tried to explain with analyzing the relationship between leverage and asset growth. On the basis of theoretical explanations, eight different leverage ratios are utilized in eight different panel data models to demonstrate the procyclicality effect of Turkish banks leverage using monthly data covering the 2005-2014 period. It is tested whether there is an increasing (decreasing) trend in the leverage ratio of Turkish banks when there is an enlargement (contraction) in their balance sheet. The major finding of the study indicates that asset growth has a significant effect on all eight leverage ratios. In other words, the leverage of Turkish banks follow a cyclical pattern, which is in line with those of earlier literature.Keywords: banking, economic cycles, leverage, procyclicality
Procedia PDF Downloads 26514043 Failure Analysis of Pipe System at a Hydroelectric Power Plant
Authors: Ali Göksenli, Barlas Eryürek
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In this study, failure analysis of pipe system at a micro hydroelectric power plant is investigated. Failure occurred at the pipe system in the powerhouse during shut down operation of the water flow by a valve. This locking had caused a sudden shock wave, also called “Water-hammer effect”, resulting in noise and inside pressure increase. After visual investigation of the effect of the shock wave on the system, a circumference crack was observed at the pipe flange weld region. To establish the reason for crack formation, calculations of pressure and stress values at pipe, flange and welding seams were carried out and concluded that safety factor was high (2.2), indicating that no faulty design existed. By further analysis, pipe system and hydroelectric power plant was examined. After observations it is determined that the plant did not include a ventilation nozzle (air trap), that prevents the system of sudden pressure increase inside the pipes which is caused by water-hammer effect. Analyses were carried out to identify the influence of water-hammer effect on inside pressure increase and it was concluded that, according Jowkowsky’s equation, shut down time is effective on inside pressure increase. The valve closing time was uncertain but by a shut down time of even one minute, inside pressure would increase by 7.6 bar (working pressure was 34.6 bar). Detailed investigations were also carried out on the assembly of the pipe-flange system by considering technical drawings. It was concluded that the pipe-flange system was not installed according to the instructions. Two of five weld seams were not applied and one weld was carried out faulty. This incorrect and inadequate weld seams resulted in; insufficient connection of the pipe to the flange constituting a strong notch effect at weld seam regions, increase in stress values and the decrease of strength and safety factorKeywords: failure analysis, hydroelectric plant, crack, shock wave, welding seam
Procedia PDF Downloads 34414042 Influence of Boron Doping and Thermal Treatment on Internal Friction of Monocrystalline Si1-xGex(x≤0,02) Alloys
Authors: I. Kurashvili, G. Darsavelidze, G. Bokuchava, A. Sichinava, I. Tabatadze
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The impact of boron doping on the internal friction (IF) and shear modulus temperature spectra of Si1-xGex(x≤0,02) monocrsytals has been investigated by reverse torsional pendulum oscillations characteristics testing. At room temperatures, microhardness and indentation modulus of the same specimens have been measured by dynamic ultra microhardness tester. It is shown that boron doping causes two kinds effect: At low boron concentration (~1015 cm-3) significant strengthening is revealed, while at the high boron concentration (~1019 cm-3) strengthening effect and activation characteristics of relaxation origin IF processes are reduced.Keywords: boron, doping, internal friction, si-ge alloys, thermal treatment
Procedia PDF Downloads 45714041 Effect of Spatially Correlated Disorder on Electronic Transport Properties of Aperiodic Superlattices (GaAs/AlxGa1-xAs)
Authors: F. Bendahma, S. Bentata, S. Cherid, A. Zitouni, S. Terkhi, T. Lantri, Y. Sefir, Z. F. Meghoufel
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We examine the electronic transport properties in AlxGa1-xAs/GaAs superlattices. Using the transfer-matrix technique and the exact Airy function formalism, we investigate theoretically the effect of structural parameters on the electronic energy spectra of trimer thickness barrier (TTB). Our numerical calculations showed that the localization length of the states becomes more extended when the disorder is correlated (trimer case). We have also found that the resonant tunneling time (RTT) is of the order of several femtoseconds.Keywords: electronic transport properties, structural parameters, superlattices, transfer-matrix technique
Procedia PDF Downloads 28514040 The Impact of Self-Viewing in Virtual Teamwork on Team Creativity: The Mediating Effect of Objective Self-Awareness and the Moderating Effect of Psychological Safety
Authors: Xueyang Li
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This thesis investigates the impact of self-viewing on team creativity in virtual teamwork and examines the role of objective self-awareness and psychological safety in this context. The study uses a quantitative research approach and collects data from 304 participants working in virtual teams. We hypothesized that observing oneself in online meetings would lead to a heightened sense of objective self and thus lower team creativity and that psychological safety would moderate their relationship. We tested these hypotheses in a laboratory experiment manipulating whether participants were able to observe themselves during the completion of an online team creativity task and manipulating whether participants were subjected to a psychological safety intervention. The results indicate that self-observation has a negative effect on team creativity in virtual teamwork, while objective self-awareness mediates this relationship, and psychological safety plays a moderating role. We discuss several aspects of the theoretical explanation of the findings. This study contributes to the existing literature by highlighting the importance of self-observation in virtual teamwork and provides practical implications for managers and team leaders to promote creativity in virtual teams.Keywords: objective self-awareness, psychological safety, self-viewing, team creativity, virtual teamwork
Procedia PDF Downloads 10014039 Effect of Long Term Orientation and Indulgence on Earnings Management: The Moderating Role of Legal Tradition
Authors: I. Martinez-Conesa, E. Garcia-Meca, M. Barradas-Quiroz
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The objective of this study is to assess the impact on earnings management of latest two Hofstede cultural dimensions: long-term orientation and indulgence. Long-term orientation represents the alignment of a society towards the future and indulgence expresses the extent to which a society exhibits willingness, or restrain, to realise their impulses. Additionally, this paper tests if there are relevant differences by testing the moderating role of the legal tradition, Continental versus Anglo-Saxon. Our sample comprises 15 countries: Belgium, Canada, Germany, Spain, France, Great Britain, Hong Kong, India, Japan, Korea, Netherlands, Philippines, Portugal, Sweden, and Thailand, with a total of 12,936 observations from 2003 to 2013. Our results show that managers in countries with high levels of long-term orientation reduce their levels of discretionary accruals. The findings do not confirm the effect of indulgence on earnings management. In addition, our results confirm previous literature regarding the effect of individualism, noting that firms in countries with high levels of collectivism might be more inclined to use earnings discretion to protect the welfare of the collective group of firm stakeholders. Uncertainty avoidance results in downwards earnings management as well as high disclosure, suggesting that less manipulation takes place when transparency is higher. Indulgence is the cultural dimension that confronts wellbeing versus survival; dimension is formulated including happiness, the perception of live control and the importance of leisure. Indulgence shows a weak negative correlation with power distance indicating a slight tendency for more hierarchical societies to be less indulgent. Anglo-Saxon countries are a positive effect of individualism and a negative effect of masculinity, uncertainty avoidance, and disclosure. With respect to continental countries, we can see a significant and positive effect of individualism and a significant and negative effect of masculinity, long-term orientation, and indulgence. Therefore, we observe the negative effect on earnings management provoked by higher disclosure and uncertainty avoidance only happens in Anglo-Saxon countries. Meanwhile, the improvement in reporting quality motivated by higher long-term orientation and higher indulgence is dominant in Continental countries. Our results confirm that there is a moderating effect of the legal system in the association between culture and earnings management. This effect is especially relevant in the dimensions related to uncertainty avoidance, long term orientation, indulgence, and disclosure. The negative effect of long-term orientation on earnings management only happens in those countries set in continental legal systems because of the Anglo-Saxon legal systems is supported by the decisions of the courts and the traditions, so it already has long-term orientation. That does not occur in continental systems, depending mainly of contend of the law. Sensitivity analysis used with Jones modified CP model, Jones Standard model and Jones Standard CP model confirm the robustness of these results. This paper collaborates towards a better understanding on how earnings management, culture and legal systems relate to each other, and contribute to previous literature by examining the influence of the two latest Hofstede’s dimensions not previously studied in papers.Keywords: Hofstede, long-term-orientation, earnings management, indulgence
Procedia PDF Downloads 23914038 Effect of Plant Growth Promoting Rhizobacteria on the Germination and Early Growth of Onion (Allium cepa)
Authors: Dragana R. Stamenov, Simonida S. Djuric, Timea Hajnal Jafari
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Plant growth promoting rhizobacteria (PGPR) are a heterogeneous group of bacteria that can be found in the rhizosphere, at root surfaces and in association with roots, enhancing the growth of the plant either directly and/or indirectly. Increased crop productivity associated with the presence of PGPR has been observed in a broad range of plant species, such as raspberry, chickpeas, legumes, cucumber, eggplant, pea, pepper, radish, tobacco, tomato, lettuce, carrot, corn, cotton, millet, bean, cocoa, etc. However, until now there has not been much research about influences of the PGPR on the growth and yield of onion. Onion (Allium cepa L.), of the Liliaceae family, is a species of great economic importance, widely cultivated all over the world. The aim of this research was to examine the influence of plant growth promoting bacteria Pseudomonas sp. Dragana, Pseudomonas sp. Kiš, Bacillus subtillis and Azotobacter sp. on the seed germination and early growth of onion (Allium cepa). PGPR Azotobacter sp., Bacillus subtilis, Pseudomonas sp. Dragana, Pseudomonas sp. Kiš, from the collection of the Faculty of Agriculture, Novi Sad, Serbia, were used as inoculants. The number of cells in 1 ml of the inoculum was 10⁸ CFU/ml. The control variant was not inoculated. The effect of PGPR on seed germination and hypocotyls length of Allium cepa was evaluated in controlled conditions, on filter paper in the dark at 22°C, while effect on the plant length and mass in semicontrol conditions, in 10 l volume vegetative pots. Seed treated with fungicide and untreated seed were used. After seven days the percentage of germination was determined. After seven and fourteen days hypocotil length was measured. Fourteen days after germination, length and mass of plants were measured. Application of Pseudomonas sp. Dragana and Kiš and Bacillus subtillis had a negative effect on onion seed germination, while the use of Azotobacter sp. gave positive results. On average, application of all investigated inoculants had a positive effect on the measured parameters of plant growth. Azotobacter sp. had the greatest effect on the hypocotyls length, length and mass of the plant. In average, better results were achieved with untreated seeds in compare with treated. Results of this study have shown that PGPR can be used in the production of onion.Keywords: germination, length, mass, microorganisms, onion
Procedia PDF Downloads 23714037 On the Network Packet Loss Tolerance of SVM Based Activity Recognition
Authors: Gamze Uslu, Sebnem Baydere, Alper K. Demir
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In this study, data loss tolerance of Support Vector Machines (SVM) based activity recognition model and multi activity classification performance when data are received over a lossy wireless sensor network is examined. Initially, the classification algorithm we use is evaluated in terms of resilience to random data loss with 3D acceleration sensor data for sitting, lying, walking and standing actions. The results show that the proposed classification method can recognize these activities successfully despite high data loss. Secondly, the effect of differentiated quality of service performance on activity recognition success is measured with activity data acquired from a multi hop wireless sensor network, which introduces high data loss. The effect of number of nodes on the reliability and multi activity classification success is demonstrated in simulation environment. To the best of our knowledge, the effect of data loss in a wireless sensor network on activity detection success rate of an SVM based classification algorithm has not been studied before.Keywords: activity recognition, support vector machines, acceleration sensor, wireless sensor networks, packet loss
Procedia PDF Downloads 47514036 Acute and Chronic Effect of Biopesticide on Infestation of Whitefly Bemisia tabaci (Gennadius) on the Culantro Cultivation
Authors: U. Pangnakorn, S. Chuenchooklin
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Acute and chronic effects of biopesticide from entomopathogenic nematode (Steinernema thailandensis n. sp.), bacteria ISR (Pseudomonas fluorescens), wood vinegar and fermented organic substances from plants: (neem Azadirachta indica + citronella grass Cymbopogon nardus Rendle + bitter bush Chromolaena odorata L.) were tested on culantro (Eryngium foetidum L.). The biopesticide was investigated for infestation reduction of the major insect pest whitefly (Bemisia tabaci (Gennadius)). The experimental plots were located at a farm in Nakhon Sawan Province, Thailand. This study was undertaken during the drought season (late November to May). Effectiveness of the treatment was evaluated in terms of acute and chronic effect. The populations of whitefly were observed and recorded every hour up to 3 hours with insect nets and yellow sticky traps after the treatments were applied for the acute effect. The results showed that bacteria ISR had the highest effectiveness for controlling whitefly infestation on culantro; the whitefly numbers on insect nets were 12.5, 10.0 and 7.5 after 1 hr, 2 hr, and 3 hr, respectively while the whitefly on yellow sticky traps showed 15.0, 10.0 and 10.0 after 1 hr, 2 hr, and 3 hr, respectively. For chronic effect, the whitefly was continuously collected and recorded at weekly intervals; the result showed that treatment of bacteria ISR found the average whitefly numbers only 8.06 and 11.0 on insect nets and sticky traps respectively, followed by treatment of nematode where the average whitefly was 9.87 and 11.43 on the insect nets and sticky traps, respectively. In addition, the minor insect pests were also observed and collected. The biopesticide influenced the reduction number of minor insect pests (red spider mites, beet armyworm, short-horned grasshopper, pygmy locusts, etc.) with only a few found on the culantro cultivation.Keywords: whitefly (Bemisia tabaci Gennadius), culantro (Eryngium foetidum L.), acute and chronic effect, entomopathogenic nematode (Steinernema thailandensis n. sp.), bacteria ISR (Pseudomonas fluorescens)
Procedia PDF Downloads 28114035 Transport of Analytes under Mixed Electroosmotic and Pressure Driven Flow of Power Law Fluid
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
Procedia PDF Downloads 31114034 Simulation of the Effect of Sea Water using Ground Tank to the Flexural Capacity of GFRP Sheet Reinforced Concrete Beams
Authors: Rudy Djamaluddin, Arbain Tata, Rita Irmawaty
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The study conducted a simulation of the effect of sea water to the bonding capacity of GFRP sheet on the concrete beams using a simulation tank. As it well known that, fiber reinforced polymer (FRP) has been applied to many purposes for civil engineering structures not only for new structures but also for strengthening of the deteriorated structures. The FRP has advantages such as its corrosion resistance, as well as high tensile strength, to weight ratio. Glass composed FRP (GFRP) sheet is most commonly used due to its relatively lower cost compared to the other FRP materials. GFRP sheet is applied externally by bonding it on the concrete surface. Many studies have been done to investigate the bonding of GFRP sheet. However, it is still very rarely studies on the effect of sea water to the bonding capacity of GFRP sheet on the strengthened beams due to flexural loadings. This is important to be clarified for the wider application of GFRP sheet especially on the flexural structure that directly contact to the sea environment. To achieve the objective of the study, a series of concrete beams strengthened with GFRP sheet on extreme tension surface were prepared. The beams then were stored on the sea water tank for six months. Results indicated the bonding capacity decreased after six months exposed to the sea water.Keywords: GFRP sheet, sea water, concrete beams, bonding
Procedia PDF Downloads 32214033 An Experimental Study on the Positive Streamer Leader Propagation under Slow Front Impulse Voltages in a 10m Rod-Plane Air Gap
Authors: Wahab Ali Shah, Junjia He
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In this work, we performed a large-scale investigation into leader development in a 10 m rod-plane gap under a long front positive impulse. To describe the leader propagation under slow front impulse voltages, we recorded the leader propagation with a high-speed charge coupled device (CCD) camera. It is important to figure out this phenomenon to deepen our understanding of leader discharge. The observation results showed that the leader mechanism is a very complex physical phenomenon; it could be categorized into two types of leader process, namely, continuous and the discontinuous leader streamer-leader propagation. Furthermore, we studied the continuous leader development parameters, including two-dimensional (2-D) leader length, injected charge, and final jump stage, as well as leader velocity for rod–plane configuration. We observed that the discontinuous leader makes an important contribution to the appearance of channel re-illuminations of the positive leader. The comparative study shows better results in terms of standard switch impulse and long front positive impulse. Finally, the results are presented with a view toward improving our understanding of propagation mechanisms related to restrike phenomena, which are rarely reported. To clarify the above doubts under long front cases, we carried out extensive experiments in this study.Keywords: continuous and discontinuous leader, high-speed photographs, long air gap, positive long front impulse, restrike phenomena
Procedia PDF Downloads 16914032 Chemical Mechanical Polishing Wastewater Treatment through Membrane Distillation
Authors: Imtisal-e-Noor, Andrew Martin, Olli Dahl
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Chemical Mechanical Polishing (CMP) has developed as a chosen planarization technique in nano-electronics industries for fabrication of the integrated circuits (ICs). These CMP processes release a huge amount of wastewater that contains oxides of nano-particles (silica, alumina, and ceria) and oxalic acid. Since, this wastewater has high solid content (TS), chemical oxygen demand (COD), and turbidity (NTU); therefore, in order to fulfill the environmental regulations, it needs to be treated up to the local and international standards. The present study proposed a unique CMP wastewater treatment method called Membrane Distillation (MD). MD is a non-isothermal membrane separation process, which allows only volatiles, i.e., water vapors to permeate through the membrane and provides 100% contaminants rejection. The performance of the MD technology is analyzed in terms of total organic carbon (TOC), turbidity, TS, COD, and residual oxide concentration in permeate/distilled water while considering different operating conditions (temperature, flow rate, and time). The results present that high-quality permeate has been recovered after removing 99% of the oxide particles and oxalic acid. The distilled water depicts turbidity < 1 NTU, TOC < 3 mg/L, TS < 50 mg/L, and COD < 100 mg/L. These findings clearly show that the MD treated water can be reused further in industrial processes or allowable to discharge in any water body under the stringent environmental regulations.Keywords: chemical mechanical polishing, environmental regulations, membrane distillation, wastewater treatment
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