Search results for: variable range hopping

Authors: Zhanfeng Ma, Zhiping Xiong, Hu Yin, Zhengwei She, Aditya P. Gurajada, Tianlun Chen, Ying Li

Abstract:

Many RDBMS vendors use B-tree index to achieve high performance for point queries and range queries, and some of them also employ hash index to further enhance the performance as hash table is more efficient for point queries. However, there are extra overheads to maintain a separate hash index, for example, hash mapping for all data records must always be maintained, which results in more memory space consumption; locking, logging and other mechanisms are needed to guarantee ACID, which affects the concurrency and scalability of the system. To relieve the overheads, Hash Cached B-tree (HCB) index is proposed in this paper, which consists of a standard disk-based B-tree index and an additional in-memory lock-free hash table. Initially, only the B-tree index is constructed for all data records, the hash table is built on the fly based on runtime workload, only data records accessed by point queries are indexed using hash table, this helps reduce the memory footprint. Changes to hash table are done using compare-and-swap (CAS) without performing locking and logging, this helps improve the concurrency and avoid contention. The hash table is also optimized to be cache conscious. HCB index is implemented in SAP ASE database, compared with the standard B-tree index, early experiments and customer adoptions show significant performance improvement. This paper provides an overview of the design of HCB index and reports the experimental results.

Keywords: B-tree, compare-and-swap, lock-free hash table, point queries, range queries, SAP ASE database

Procedia PDF Downloads 281

Authors: Pongchanun Luangpaiboon, Wanwisa Sarasang

Abstract:

In this paper, a performance of shuffled frog leaping algorithm was investigated on the stealth laser dicing process. Effect of problem on the performance of the algorithm was based on the tolerance of meandering data. From the customer specification it could be less than five microns with the target of zero microns. Currently, the meandering levels are unsatisfactory when compared to the customer specification. Firstly, the two-level factorial design was applied to preliminary study the statistically significant effects of five process variables. In this study one influential process variable is integer. From the experimental results, the new operating condition from the algorithm was superior when compared to the current manufacturing condition.

Keywords: stealth laser dicing process, meandering, meta-heuristics, shuffled frog leaping algorithm

Procedia PDF Downloads 331

Authors: Mohammad Zainie Bin Hassan

Abstract:

Background: Erectile dysfunction (ED) is a complication commonly seen among men with diabetes which can be assessed based upon International Index of Erectile Function (IIEF-5) questionnaire. Creatinine level is a blood test that indicates kidney functionality. Object: To evaluate the association between ED, determined by the IIEF-5scores and Creatinine level in diabetic men attending Temerloh Health Clinic, Pahang, Malaysia.Hence, to identify raising Creatinine level related with ED or not. Methods: All married diabetic patients will be investigated face to face after consented for answering the IIEF-5 questionnaire. Creatinine level will be taken by using standard method.Patients with no sexual partner, refuse to answer the questionnaire, cancer, stroke, heart disease and language barrier will be excluded.Data obtained from IIEF-5 score and Creatinine level will be analyzed by using Pearson correlation. All statistical value determined by p=0.05. ED will be categorized accordingly to IIEF-5 scores: no ED (22-25), mild (17-21), moderate (12-16), severe (8-11) and very severe (1-7). Results: A total of 450 patients were investigated with 385 patients were included (85.6% respondant rate) and 65 patients were excluded in this study with age range from 29 to 85 years old. 7% had no ED, 28% mild ED, 34% moderate ED, 16% severe ED and 15% had very severe ED. There was a significant negative correlation between Creatinine level and IIEF-5 scores (r=-0.218, p <0.001). This result implicated that poor kidney function which indicated by high Creatinine level associated significantly with erectile dysfunction. 93% had ED with a different range of severity which triggers for appropriate aggressive ED management among diabetics. Conclusion: The high level of Creatinine is associated with erectile dysfunction among diabetics in Temerloh Health Clinic.

Keywords: correlation, creatinine level, erectile dysfunction, ED, diabetes

Procedia PDF Downloads 381

Authors: Tomasz Robert Kuczerski

Abstract:

The high complexity of the algorithm of the autonomous tandem detonator system creates an optimization problem due to the parallel operation of several machine states of the system. Many years of experience and classic analyses have led to a partially optimized model. Limitations on the energy resources of this class of autonomous systems make it necessary to search for more effective methods of optimisation. The use of the Quantum Approximate Optimization Algorithm (QAOA) in these studies shows the most promising results. With the help of multiple evaluations of several qubit quantum circuits, proper results of variable parameter optimization were obtained. In addition, it was observed that the increase in the number of assessments does not result in further efficient growth due to the increasing complexity of optimising variables. The tests confirmed the effectiveness of the QAOA optimization method.

Keywords: algorithm analysis, autonomous system, quantum optimization, tandem detonator

Procedia PDF Downloads 85

Authors: Wageeh A. Nafei

Abstract:

This paper explores the role of Paradoxical Leadership (PL) in enhancing Organizational Success (OS) at private hospitals in Egypt. Based on the collected data from employees in private hospitals (doctors, nursing staff, and administrative staff). The researcher has adopted a sampling method to collect data for the study. The appropriate statistical methods, such as Alpha Correlation Coefficient (ACC), Confirmatory Factor Analysis (CFA), and Multiple Regression Analysis (MRA), are used to analyze the data and test the hypotheses. The research has reached a number of results, the most important of which are (1) there is a statistical relationship between the independent variable represented by PL and the dependent variable represented by Organizational Success (OS). The paradoxical leader encourages employees to express their opinions and builds a work environment characterized by flexibility and independence. Also, the paradoxical leader works to support specialized work teams, which leads to the creation of new ideas, on the one hand, and contributes to the achievement of outstanding performance on the other hand. (2) the mentality of the paradoxical leader is flexible and capable of absorbing all suggestions from all employees. Also, the paradoxical leader is interested in enhancing cooperation among them and provides an opportunity to transfer experience and increase knowledge-sharing. Also, the sharing of knowledge creates the necessary diversity that helps the organization to obtain rich external information and enables the organization to deal with a rapidly changing environment. (3) The PL approach helps in facing the paradoxical demands of employees. A paradoxical leader plays an important role in reducing the feeling of instability in the work environment and lack of job security, reducing negative feelings for employees, restoring balance in the work environment, improving the well-being of employees, and increasing the degree of job satisfaction of employees in the organization. The study referred to a number of recommendations, the most important of which are (1) the leaders of the organizations must listen to the views of employees and their needs and move away from the official method of control. The leader should give sufficient freedom to employees to participate in decision-making and maintain enough space among them. The treatment between the leaders and employees must be based on friendliness, (2) the need for organizational leaders to pay attention to sharing knowledge among employees through training courses. The leader should make sure that every information provided by the employee is valuable and useful, which can be used to solve a problem that may face his/her colleagues at work, (3) the need for organizational leaders to pay attention to sharing knowledge among employees through brainstorming sessions. The leader should ensure that employees obtain knowledge from their colleagues and share ideas and information among them. This is in addition to motivating employees to complete their work in a new creative way, which leads to employees’ not feeling bored of repeating the same routine procedures in the organization.

Keywords: paradoxical leadership, organizational success, human resourece, management

Procedia PDF Downloads 50

Authors: Gary J. Pickering, Sarah Lucas, Catherine E. Klodnicki, Nicole J. Gaudette

Abstract:

Two taste pheno types that are of interest in the study of habitual diet-related risk factors and disease are 6-n-propylthiouracil (PROP) responsiveness and thermal tasting. Individuals differ considerable in how intensely they experience the bitterness of PROP, which is partially explained by three major single nucleotide polymorphisms associated with the TAS2R38 gene. Importantly, this variable responsiveness is a useful proxy for general taste responsiveness, and links to diet-related disease risk, including body mass index, in some studies. Thermal tasting - a newly discovered taste phenotype independent of PROP responsiveness - refers to the capacity of many individuals to perceive phantom tastes in response to lingual thermal stimulation, and is linked with TRPM5 channels. Thermal tasters (TTs) also experience oral sensations more intensely than thermal non-tasters (TnTs), and this was shown to associate with differences in self-reported food preferences in a previous survey from our lab. Here we report on two related studies, where we sought to determine whether PROP responsiveness and thermal tasting would associate with perceptual differences in the oral sensations elicited by sampled energy-dense foods, and whether in turn this would influence liking. We hypothesized that hyper-tasters (thermal tasters and individuals who experience PROP intensely) would (a) rate sweet and high-fat foods more intensely than hypo-tasters, and (b) would differ from hypo-tasters in liking scores. (Liking has been proposed recently as a more accurate measure of actual food consumption). In Study 1, a range of energy-dense foods and beverages, including table cream and chocolate, was assessed by 25 TTs and 19 TnTs. Ratings of oral sensation intensity and overall liking were obtained using gVAS and gDOL scales, respectively. TTs and TnTs did not differ significantly in intensity ratings for most stimuli (ANOVA). In a 2nd study, 44 female participants sampled 22 foods and beverages, assessing them for intensity of oral sensations (gVAS) and overall liking (9-point hedonic scale). TTs (n=23) rated their overall liking of creaminess and milk products lower than did TnTs (n=21), and liked milk chocolate less. PROP responsiveness was negatively correlated with liking of food and beverages belonging to the sweet or sensory food grouping. No other differences in intensity or liking scores between hyper- and hypo-tasters were found. Taken overall, our results are somewhat unexpected, lending only modest support to the hypothesis that these taste phenotypes associate with energy-dense food liking and consumption through differences in the oral sensations they elicit. Reasons for this lack of concordance with expectations and some prior literature are discussed, and suggestions for future research are advanced.

Keywords: taste phenotypes, sensory evaluation, PROP, thermal tasting, diet-related health risk

Procedia PDF Downloads 451

Authors: Sara Mensou, Ahmed Essadki, Issam Minka, Tamou Nasser, Badr Bououlid Idrissi

Abstract:

In this paper we present a contribution for the modeling and control of wind energy conversion system based on a Doubly Fed Induction Generator (DFIG). Since the wind speed is random the system has to produce an optimal electrical power to the Network and ensures important strength and stability. In this work, the Backstepping controller is used to control the generator via two converter witch placed a DC bus capacitor and connected to the grid by a Filter R-L, in order to optimize capture wind energy. All is simulated and presented under MATLAB/Simulink Software to show performance and robustness of the proposed controller.

Keywords: wind turbine, doubly fed induction generator, MPPT control, backstepping controller, power converter

Procedia PDF Downloads 177

Authors: Dibyendu Roy, V. Ramu Reddy, Parijat Deshpande, Ranjan Dasgupta

Abstract:

Imaging of underwater objects is primarily conducted by acoustic imagery due to the severe attenuation of electro-magnetic waves in water. Acoustic imagery underwater has varied range of significant applications such as side-scan sonar, mine hunting sonar. It also finds utility in other domains such as imaging of body tissues via ultrasonography and non-destructive testing of objects. In this paper, we explore the feasibility of using active acoustic imagery in air and simulate phased array beamforming techniques available in literature for various array designs to achieve a suitable acoustic sensor array design for a portable mobile robot which can be applied to detect the presence/absence of anomalous objects in a room. The multi-path reflection effects especially in enclosed rooms and environmental noise factors are currently not simulated and will be dealt with during the experimental phase. The related hardware is designed with the same feasibility criterion that the developed system needs to be deployed on a portable mobile robot. There is a trade of between image resolution and range with the array size, number of elements and the imaging frequency and has to be iteratively simulated to achieve the desired acoustic sensor array design. The designed acoustic imaging array system is to be mounted on a portable mobile robot and targeted for use in surveillance missions for intruder alerts and imaging objects during dark and smoky scenarios where conventional optic based systems do not function well.

Keywords: acoustic sensor array, acoustic imagery, anomaly detection, phased array beamforming

Procedia PDF Downloads 400

Authors: Wenfu Zheng, Guanghe Zheng

Abstract:

The discussion on the social sustainability in existing literature is limited to two-dimension epistemology space with only two elements: the human and nature. Using the revelation of the Bible God, the paper adds a moral component to the two-dimension space. With the new variable being introduced, the authors formulate a to three-dimension epistemology space and discuss its implications. Based on the space, the authors explore the hierarchical structure of order principles for a sustainable society. The social order principle system hierarchically consists of three principles: moral, relational, and rational. The justification of every principle is analyzed briefly. The paper concluded that all these order principles are necessary assurance of building a sustainable society.

Keywords: common grace, saving grace, sustainable society, the image of God

Procedia PDF Downloads 184

Authors: Pedro F. Albuquerque, Pedro V. Gamboa, Miguel A. Silvestre

Abstract:

The present work describes the implementation of the Enhanced Collaborative Optimization (ECO) multilevel architecture with a gradient-based optimization algorithm with the aim of performing a multidisciplinary design optimization of a generic unmanned aerial vehicle with morphing technologies. The concepts of weighting coefficient and a dynamic compatibility parameter are presented for the ECO architecture. A routine that calculates the aircraft performance for the user defined mission profile and vehicle’s performance requirements has been implemented using low fidelity models for the aerodynamics, stability, propulsion, weight, balance and flight performance. A benchmarking case study for evaluating the advantage of using a variable span wing within the optimization methodology developed is presented.

Keywords: multidisciplinary, multilevel, morphing, enhanced collaborative optimization

Procedia PDF Downloads 921

Authors: Basma Hamdi, Lakdar Kairouani, Ezzedine Nahdi

Abstract:

The objective of this work is to present a thermodynamic analysis of low temperature solar Rankine cycle with ejector for power generation using zeotropic mixtures. Based on theoretical calculation, effects of zeotropic mixtures compositions on the performance of solar Rankine cycle with ejector are discussed and compared with corresponding pure fluids. Variations of net power output, thermal efficiency were calculating with changing evaporation temperature. The ejector coefficient had analyzed as independent variable. The result show that (R245fa/R152a) has a higher thermal efficiency than using pure fluids.

Keywords: zeotropic mixture, thermodynamic analysis, ejector, low-temperature solar rankine cycle

Procedia PDF Downloads 277

Authors: Qaisar Ali, Waqar A. Khan, Shafiq R. Qureshi

Abstract:

Heat transfer in Power Law Fluids across cylindrical surfaces has copious engineering applications. These applications comprises of areas such as underwater pollution, bio medical engineering, filtration systems, chemical, petroleum, polymer, food processing, recovery of geothermal energy, crude oil extraction, pharmaceutical and thermal energy storage. The quantum of research work with diversified conditions to study the effects of combined heat transfer and fluid flow across porous media has increased considerably over last few decades. The most non-Newtonian fluids of practical interest are highly viscous and therefore are often processed in the laminar flow regime. Several studies have been performed to investigate the effects of free and mixed convection in Newtonian fluids along vertical and horizontal cylinder embedded in a saturated porous medium, whereas very few analysis have been performed on Power law fluids along wedge. In this study, boundary layer analysis under the effects of radiation-mixed convection in power law fluids along vertical wedge in porous medium have been investigated using an implicit finite difference method (Keller box method). Steady, 2-D laminar flow has been considered under prescribed surface heat flux condition. Darcy, Boussinesq and Roseland approximations are assumed to be valid. Neglecting viscous dissipation effects and the radiate heat flux in the flow direction, the boundary layer equations governing mixed convection flow over a vertical wedge are transformed into dimensionless form. The single mathematical model represents the case for vertical wedge, cone and plate by introducing the geometry parameter. Both similar and Non- similar solutions have been obtained and results for Non similar case have been presented/ plotted. Effects of radiation parameter, variable heat flux parameter, wedge angle parameter ‘m’ and mixed convection parameter have been studied for both Newtonian and Non-Newtonian fluids. The results are also compared with the available data for the analysis of heat transfer in the prescribed range of parameters and found in good agreement. Results for the details of dimensionless local Nusselt number, temperature and velocity fields have also been presented for both Newtonian and Non-Newtonian fluids. Analysis of data revealed that as the radiation parameter or wedge angle is increased, the Nusselt number decreases whereas it increases with increase in the value of heat flux parameter at a given value of mixed convection parameter. Also, it is observed that as viscosity increases, the skin friction co-efficient increases which tends to reduce the velocity. Moreover, pseudo plastic fluids are more heat conductive than Newtonian and dilatant fluids respectively. All fluids behave identically in pure forced convection domain.

Keywords: porous medium, power law fluids, surface heat flux, vertical wedge

Procedia PDF Downloads 307

Authors: Ali Mashayekh, Mahdiye Khorasani, Thomas Weyh

Abstract:

The tendency to use the Battery-Electric vehicle (BEV) for the low and medium driving range or even high driving range has been growing more and more. As a result, higher safety, reliability, and durability of the battery pack as a component of electric vehicles, which has a great share of cost and weight of the final product, are the topics to be considered and investigated. Battery aging can be considered as the predominant factor regarding the reliability and durability of BEV. To better understand the aging process, offline battery characterization has been widely used, which is time-consuming and needs very expensive infrastructures. This paper presents the substitute method for the conventional battery characterization methods, which is based on battery Modular Multilevel Management (BM3). According to this Topology, the battery cells can be drained and charged concerning their capacity, which allows varying battery pack structures. Due to the integration of the power electronics, the output voltage of the battery pack is no longer fixed but can be dynamically adjusted in small steps. In other words, each cell can have three different states, namely series, parallel, and bypass in connection with the neighbor cells. With the help of MATLAB/Simulink and by using the BM3 modules, the battery string model is created. This model allows us to switch two cells with the different SoC as parallel, which results in the internal balancing of the cells. But if the parallel switching lasts just for a couple of ms, we can have a perturbation pulse which can stimulate the cells out of the relaxation phase. With the help of modeling the voltage response pulse of the battery, it would be possible to characterize the cell. The Online EIS method, which is discussed in this paper, can be a robust substitute for the conventional battery characterization methods.

Keywords: battery characterization, SoH estimation, RLS, BEV

Procedia PDF Downloads 142

Authors: Mantas Sriubas, Kristina Bockute, Darius Virbukas, Giedrius Laukaitis

Abstract:

In this work, the doped TiO2 (dopants – Ca, Mg) was investigated. The comparison between the physical vapour deposition methods as electron beam vapour deposition and magnetron sputtering was performed and the structural and electrical properties of the formed thin films were investigated. Thin films were deposited on different type of substrates: SiO2, Alloy 600 (Fe-Ni-Cr) and Al2O3 substrates. The structural properties were investigated using Ambios XP-200 profilometer, scanning electron microscope (SEM) Hitachi S-3400N, X-ray energy-dispersive spectroscope (EDS) Quad 5040 (Bruker AXS Microanalysis GmbH), X-ray diffractometer (XRD) D8 Discover (Bruker AXS GmbH) with glancing angles focusing geometry in a 20 – 70° range using the Cu Kα1 λ = 0.1540562 nm radiation). The impedance spectroscopy measurements were performed using Probostat® (NorECs AS) measurement cell in the frequency range from 10-1-106 Hz under reducing and oxidizing conditions in temperature range of 200 °C to 1200 °C. The investigation of the e-beam deposited Ca and Mg doped-TiO2 thin films shows that the thin films are dense without any visible pores and cavities and the thin films grow in zone T according Barna-Adamik SZM. Substrate temperature was kept 600 °C during the deposition and Ts/Tm ≈ 0.32 (substrate temperature (Ts) and coating material melting temperature (Tm)). The surface diffusion is high however, the grain boundary migration is strongly limited at this temperature. This means that structure is inhomogeneous and the columnar structure is mostly visible in the upper part of the films. According to XRD, the increasing of the Ca dopants’ concentration increases the crystallinity of the formed thin films and the crystallites size increase linearly and Ca dopants act as prohibitors. Thin films are comprised of anatase TiO2 phase with an exception of 2 % Ca doped TiO2, where a small peak of Ca arise. In the case of Mg doped-TiO2 the intensities of the XRD peaks decreases with increasing Mg molar concentration. It means that there are less diffraction planes of the particular orientation in thin films with higher impurities concentration. Thus, the crystallinity decreases with increasing Mg concentration and Mg dopants act as inhibitors. The impedance measurements show that the dopants changed the conductivity of the formed thin films. The conductivity varies from 10-3 S/cm to 10-4 S/cm at 800 °C under wet reducing conditions. The microstructure of the magnetron sputtered thin TiO2 films is different comparing to the thin films deposited using e-beam deposition therefore influencing other structural and electrical properties.

Keywords: electrical properties, electron beam deposition, magnetron sputtering, microstructure, titanium dioxide

Procedia PDF Downloads 290

Authors: Cherifi Katia, Al-Hawat Marie-Lynn, Tricou Leo-Paul, Lamontagne Stephanie, Tran Minh, Ngu Amy Ching Yie, Manrique Gabriela, Guirguis Natalie, Machuca Parra Arturo Israel, Matoori Simon

Abstract:

Diabetic foot ulcers (DFUs) are a serious and prevalent complication of diabetes. Current diagnostic options are limited to macroscopic wound analysis such as wound size, depth, and infection. Molecular diagnostics promise to improve DFU diagnosis, staging, and assessment of treatment response. Here, we developed a rapid and easy-to-use fluorescent pH-sensing bandage for wound diagnostics. In a fluorescent dye screen, we identified pyranine as the lead compound due to its suitable pH-sensing properties in the clinically relevant pH range of 6 to 9. To minimize the release of this dye into the wound bed, we screened a library of ionic microparticles and found a strong adhesion of the anionic dye to a cationic polymeric microparticle. These dye-loaded microparticles showed a strong fluorescence response in the clinically relevant pH range of 6 to 9 and a dye release below 1% after one day in biological media. The dye-loaded microparticles were subsequently encapsulated in a calcium alginate hydrogel to minimize the interaction of the microparticles with the wound tissue. This pH-sensing diagnostic wound dressing was tested on full-thickness dorsal wounds of mice, and a linear fluorescence response (R2 = 0.9909) to clinically relevant pH values was observed. These findings encourage further development of this pH-sensing system for molecular diagnostics in DFUs.

Keywords: wound ph, fluorescence, diagnostics, diabetic foot ulcer, wound healing, chronic wounds, diabetes

Procedia PDF Downloads 75

Authors: Majid Zargar, Frank Bullen, Ron Ayers

Abstract:

One of the important factors in the design of asphalt concrete mixes is the accurate measurement of air voids and their variable distribution. Both can have significant impact on long and short term fatigue and creep behaviour under traffic. While some simple methods exist for overall evaluation of air voids, measuring air void distribution in asphalt concrete is very complex, involving expensive techniques such as X-ray methodologies. The research reported in the paper investigated the use of non-destructive ultrasonic techniques as an alternative to estimate the amount of air voids and their distribution within asphalt samples. Seventy-four Standard AC–14 asphalt samples made with three types of bitumen; Multigrade, PMB and C320 were analysed using ultrasonic techniques. The results have illustrated that ultrasonic testing has the potential of being a rapid, accurate and cost-effective method of estimating air void distribution in asphalt.

Keywords: asphalt concrete, air voids, ultrasonic, mechanical behaviour

Procedia PDF Downloads 340

Authors: Mayank Sharma

Abstract:

Groundwater has been a matter of great concern in the past years due to the depletion in the water table. This has resulted from the over-exploitation of groundwater resources. Sub-surface exploration of groundwater is a great way to identify the groundwater potential of an area. Thus, in order to meet the water needs for irrigation in the study area, there was a need for a tube well to be installed. Therefore, a Geophysical investigation was carried out to find the most suitable point of drilling and sinking of tube well that encounters an aquifer. Hence, an electrical resistivity survey of geophysical exploration was used to know the aquifer zones of the area. The Vertical Electrical Sounding (VES) method was employed to know the subsurface geology of the area. Seven vertical electrical soundings using Schlumberger electrode array were carried out, having the maximum AB electrode separation of 700m at selected points in Ayma, Kharagpur-1 block of Paschim Midnapore district, West Bengal. The VES was done using an IGIS DDR3 Resistivity meter up to an approximate depth of 160-180m. The data was interpreted, processed and analyzed. Based on all the interpretations using the direct method, the geology of the area at the points of sounding was interpreted. It was established that two deeper clay-sand sections exist in the area at a depth of 50-70m (having resistivity range of 40-60ohm-m) and 70-160m (having resistivity range of 25-35ohm-m). These aquifers will provide a high yield of water which would be sufficient for the desired irrigation in the study area.

Keywords: VES method, Schlumberger method, electrical resistivity survey, geophysical exploration

Procedia PDF Downloads 188

Authors: Muhammad Mufakkar, Ghulam Hussain Bhatti, Maryem Rana

Abstract:

The study of the coordination behavior of thiones is of considerable interest due to the similarity of their binding sites to those in living systems. The complexation of thiones towards Copper(I) has also received considerable attraction in view of their variable bonding modes, structural diversity and promising biological implications. Copper (I) complexes of thioureas of the general formula: CuLCl, CuL2Cl and CuL3Cl [where L= Thiourea and its N- and N, N/- mono and di alkyl and phenyl derivatives] have been prepared using Cu(I)CN in the presence of HCl. The complexes have been characterized by thermal, IR and NMR(1H and 13C) spectroscopy. An upfield shift in 13C NMR and downfield shifts in 1H NMR are consistent with the sulfur coordination to Copper(I). The disappearance of a band around 2200 cm⁻¹ in IR and a resonance around 146 ppm in 13C NMR indicates that during the course of reaction the cyanide group of the Copper(I) salt has been replaced by chloride leading to the formation of chlorido complexes.

Keywords: Thiones, complexation, spectra, TGA, thermogram, chemical shifts, deshielding, resonance

Procedia PDF Downloads 230

Authors: Seyedeh Khadijeh Amirian, Seyed Mohammad Reza Amirian, Narges Hekmati

Abstract:

The current study aims at examining the relationship between English as a foreign language (EFL) students' self-concept and their willingness to communicate (WTC) in EFL classes. To this effect, two questionnaires, namely 'Willingness to Communicate' (MacIntyre et al., 2001) and 'Self-Concept Scale' (Liu and Wang, 2005), were distributed among 174 (45 males and 129 females) Iranian EFL university students. Correlation and regression analyses were conducted to examine the relationship between the two variables. The results indicated that there was a significantly positive correlation between EFL students' self-concept and their WTC in EFL classes (p < .0.05). Moreover, regression analyses indicated that self-concept has a significantly positive influence on students’ WTC in language classes (B= .302, p < .0.05) and explains .302 percent of the variance in the dependent variable (WTC). The results are discussed with regards to the individual differences in educational contexts, and implications are offered.

Keywords: EFL students, language classes, willingness to communicate, self-concept

Procedia PDF Downloads 116

Authors: Raziyeh Shamsi

Abstract:

In this paper, we present a multiple objective linear programming (MOLP) problem in full fuzzy case and find Data Envelopment Analysis(DEA) targets. In the presented model, we are seeking the least inputs and the most outputs in the production possibility set (PPS) with the variable return to scale (VRS) assumption, so that the efficiency projection is obtained for all decision making units (DMUs). Then, we provide an algorithm for finding DEA targets interactively in the full fuzzy case, which solves the full fuzzy problem without defuzzification. Owing to the use of interactive methods, the targets obtained by our algorithm are more applicable, more realistic, and they are according to the wish of the decision maker. Finally, an application of the algorithm in 21 educational institutions is provided.

Keywords: DEA, MOLP, full fuzzy, target

Procedia PDF Downloads 297

Authors: Omid Khaiyat, David Hawkes

Abstract:

Introduction: There remains a lack of information on sophisticated coordination patterns across shoulder girdle muscles. Considering the stability of the shoulder being heavily dependent on coordinated muscle activity during its wide-ranging movements, it is important that key intermuscular relationships are well-defined for a better understanding of underlying pathology. This study investigated shoulder intermuscular coordination during different planes of shoulder elevation. Materials and Methods: EMG was recorded from 14 shoulder muscles in 20 healthy participants during shoulder flexion, scapula plane elevation, abduction, and extension. Cross-correlation by means of Pearson Correlation Coefficient (PCC) was used to examine the coordination between different muscles and muscle groups. Results: Coordination between rotator cuff and deltoid muscle groups was significantly higher (p =0.020-0.035) during the initial (PCC) = 0.79) and final (PCC = 0.74) phases of elevation compared to the mid-range (PCC = 0.34). Furthermore, a high level of coordination (PCC = 0.89) was noted between the deltoid group and the adductor group (latissimus dorsi and teres major) during the initial stage of shoulder elevation. Conclusion: The destabilising force of the deltoid during the initial stage of shoulder elevation is balanced by coordinated activity of rotator cuff, latissimus dorsi, and teres major. This is also the case for the end-range of movement, where increased demand for stability again leads to higher coordination between the deltoid and rotator cuff muscle groups. Appreciation of the sophistication of normal shoulder function evidence-based rehabilitation strategies for conditions such as subacromial impingement syndrome or shoulder instability can be developed.

Keywords: shoulder, coordination, EMG, muscle activity, upper limb

Procedia PDF Downloads 159

Authors: Asma Alzahrani, Elizabeth Stojanovski

Abstract:

This study investigated factors that influence mathematics achievement based on a sample of ninth-grade students (N  =  21,444) from the High School Longitudinal Study of 2009 (HSLS09). Key aspects studied included efficacy in mathematics, interest and enjoyment of mathematics, identity with mathematics and future utility beliefs and how these influence mathematics achievement. The predictability of mathematics achievement based on these factors was assessed using correlation coefficients and multiple linear regression. Spearman rank correlations and multiple regression analyses indicated positive and statistically significant relationships between the explanatory variables: mathematics efficacy, identity with mathematics, interest in and future utility beliefs with the response variable, achievement in mathematics.

Keywords: Mathematics achievement, math efficacy, mathematics interest, factors influence

Procedia PDF Downloads 140

Authors: Wendy Flory, Kazi Czarnecki, Matthijs Mercy, Mark Joswiak, Mary Beth Seasholtz

Abstract:

Polyurethane Materials are present in a wide range of industrial segments such as Furniture, Building and Construction, Composites, Automotive, Electronics, and more. Dow is one of the leaders for the manufacture of the two main raw materials, Isocyanates and Polyols used to produce polyurethane products. Dow is also a key player for the manufacture of Polyurethane Systems/Formulations designed for targeted applications. In 1990, the first analytical chemometric models were developed and deployed for use in the Dow QC labs of the polyols business for the quantification of OH, water, cloud point, and viscosity. Over the years many models have been added; there are now over 140 models for quantification and hundreds for product identification, too many to be reasonable for support. There are 29 global models alone for the quantification of OH across > 70 products at many sites. An attempt was made to consolidate these into a single model. While the consolidated model proved good statistics across the entire range of OH, several products had a bias by ASTM E1655 with individual product validation. This project summary will show the strategy for global model updates for OH, to reduce the number of models for quantification from over 140 to 5 or less using chemometric methods. In order to gain an understanding of the best product groupings, we identify clusters by reducing spectra to a few dimensions via Principal Component Analysis (PCA) and Uniform Manifold Approximation and Projection (UMAP). Results from these cluster analyses and a separate validation set allowed dow to reduce the number of models for predicting OH from 29 to 3 without loss of accuracy.

Keywords: hydroxyl, global model, model maintenance, near infrared, polyol

Procedia PDF Downloads 129

Authors: Muneer Abbad

Abstract:

In search of better, traditional learning universities have expanded their ways to deliver knowledge and integrate cost effective e-learning systems. Universities’ use of information and communication technologies has grown tremendously over the last decade. To ensure efficient use of the e-learning system, this project aimed to evaluate the good and bad practices, detect errors and determine areas for further improvements in usage. This project critically evaluated the students’ perception of the e-learning system and recommended changes to improve students’ e-learning usage, through conducting questionnaire given to the students that have experience with e-learning systems. Results of the study indicated that, in general, students have favourable perceptions toward using the e-learning system. They seemed to value the resources tool and its contribution to building their knowledge more than other e-learning tools. However, they seemed to perceive a limited value from the audio or video podcasts. This study has shown that technology acceptance is the most variable, factor that contributes to students’ perception and satisfaction of the e-learning system.

Keywords: e-learning, perception, Jordan, universities

Procedia PDF Downloads 483

Authors: Yakui Bai, Chen Sun, Ke Wang

Abstract:

An experimental investigation of environmental effect on fatigue behavior in SA508 Gr.3 Cl.2 Steam Generator Forging CAP1400 nuclear power plant has been carried out. In order to simulate actual loading condition, a range of strain amplitude was applied in different low cycle fatigue (LCF) tests. The current American Society of Mechanical Engineers (ASME) design fatigue code does not take full account of the interactions of environmental, loading, and material's factors. A range of strain amplitude was applied in different low cycle fatigue (LCF) tests at a strain rate of 0.01%s⁻¹. A design fatigue model was constructed by taking environmentally assisted fatigue effects into account, and the corresponding design curves were given for the convenience of engineering applications. The corrosion fatigue experiment was performed in a strain control mode in 320℃ borated and lithiated water environment to evaluate the effects of a mixed environment on fatigue life. Stress corrosion cracking (SCC) in steam generator large forging in primary water of pressurized water reactor was also observed. In addition, it is found that the CF life of SA508 Gr.3 Cl.2 decreases with increasing temperature in the water environment. The relationship between the reciprocal of temperature and the logarithm of fatigue life was found to be linear. Through experiments and subsequent analysis, the mechanisms of reduced low cycle fatigue life have been investigated for steam generator forging.

Keywords: failure behavior, low alloy steel, steam generator forging, stress corrosion cracking

Procedia PDF Downloads 116

Authors: Shalini Singh, Sanjay K. Srivastava, Govind, Mukhtar. A. Khan, P. K. Singh

Abstract:

Nanotechnology is revolutionizing the development of biosensors. Nanomaterials and nanofabrication technologies are increasingly being used to design novel biosensors. Sensitivity and other attributes of biosensors can be improved by using nanomaterials with unique chemical, physical, and mechanical properties in their construction. Silicon is a promising biomaterial that is non-toxic and biodegradable and can be exploited in chemical and biological sensing. Present study demonstrated the streptavidin–biotin interaction on silicon surfaces with different topographies such as flat and nanostructured silicon (nanowires) surfaces. Silicon nanowires with wide range of surface to volume ratio were prepared by electrochemical etching of silicon wafer. The large specific surface of silicon nanowires can be chemically modified to link different molecular probes (DNA strands, enzymes, proteins and so on), which recognize the target analytes, in order to enhance the selectivity and specificity of the sensor device. The interaction of streptavidin with biotin was carried out on 3-aminopropyltriethoxysilane (APTS) functionalized silicon surfaces. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) studies have been performed to characterize the surface characteristics to ensure the protein attachment. Silicon nanowires showed the enhance protein attachment, as compared to flat silicon surface due to its large surface area and good molecular penetration to its surface. The methodology developed herein could be generalized to a wide range of protein-ligand interactions, since it is relatively easy to conjugate biotin with diverse biomolecules such as antibodies, enzymes, peptides, and nucleotides.

Keywords: FTIR, silicon nanowires, streptavidin-biotin, XPS

Procedia PDF Downloads 407

Authors: Miriam Sosa, Edgar Ortiz, Alejandra Cabello

Abstract:

This paper examines the volatility changes and leverage effects of the MILA stock markets and their changes since the 2007 global financial crisis. This group integrates the stock markets from Chile, Colombia, Mexico and Peru. Volatility changes and leverage effects are tested with a symmetric GARCH (1,1) and asymmetric TARCH (1,1) models with a dummy variable in the variance equation. Daily closing prices of the stock indexes of Chile (IPSA), Colombia (COLCAP), Mexico (IPC) and Peru (IGBVL) are examined for the period 2003:01 to 2015:02. The evidence confirms the presence of an overall increase in asymmetric market volatility in the Peruvian share market since the 2007 crisis.

Keywords: financial crisis, Latin American Integrated Market, TARCH, GARCH

Procedia PDF Downloads 271

Authors: Elisa Boatti, Ulisse Stefanelli, Alessandro Reali, Ferdinando Auricchio

Abstract:

Thanks to their unusual properties, shape memory alloys (SMAs) are good candidates for advanced applications in a wide range of engineering fields, such as automotive, robotics, civil, biomedical, aerospace. In the last decades, the ever-growing interest for such materials has boosted several research studies aimed at modeling their complex nonlinear behavior in an effective and robust way. Since the constitutive response of SMAs is strongly thermomechanically coupled, the investigation of the non-isothermal evolution of the material must be taken into consideration. The present study considers an existing three-dimensional phenomenological model for SMAs, able to reproduce the main SMA properties while maintaining a simple user-friendly structure, and proposes a variational reformulation of the full non-isothermal version of the model. While the considered model has been thoroughly assessed in an isothermal setting, the proposed formulation allows to take into account the full nonisothermal problem. In particular, the reformulation is inspired to the GENERIC (General Equations for Non-Equilibrium Reversible-Irreversible Coupling) formalism, and is based on a generalized gradient flow of the total entropy, related to thermal and mechanical variables. Such phrasing of the model is new and allows for a discussion of the model from both a theoretical and a numerical point of view. Moreover, it directly implies the dissipativity of the flow. A semi-implicit time-discrete scheme is also presented for the fully coupled thermomechanical system, and is proven unconditionally stable and convergent. The correspondent algorithm is then implemented, under a space-homogeneous temperature field assumption, and tested under different conditions. The core of the algorithm is composed of a mechanical subproblem and a thermal subproblem. The iterative scheme is solved by a generalized Newton method. Numerous uniaxial and biaxial tests are reported to assess the performance of the model and algorithm, including variable imposed strain, strain rate, heat exchange properties, and external temperature. In particular, the heat exchange with the environment is the only source of rate-dependency in the model. The reported curves clearly display the interdependence between phase transformation strain and material temperature. The full thermomechanical coupling allows to reproduce the exothermic and endothermic effects during respectively forward and backward phase transformation. The numerical tests have thus demonstrated that the model can appropriately reproduce the coupled SMA behavior in different loading conditions and rates. Moreover, the algorithm has proved effective and robust. Further developments are being considered, such as the extension of the formulation to the finite-strain setting and the study of the boundary value problem.

Keywords: generalized gradient flow, GENERIC formalism, shape memory alloys, thermomechanical coupling

Procedia PDF Downloads 218

Authors: J. Plocek, P. Holec, S. Kubickova, B. Pacakova, I. Matulkova, A. Mantlikova, I. Němec, D. Niznansky, J. Vejpravova

Abstract:

This article presents summary on preparation and characterization of zinc, copper, cadmium and cobalt chromite nano crystals, embedded in an amorphous silica matrix. The ZnCr2O4/SiO2, CuCr2O4/SiO2, CdCr2O4/SiO2 and CoCr2O4/SiO2 nano composites were prepared by a conventional sol-gel method under acid catalysis. Final heat treatment of the samples was carried out at temperatures in the range of 900–1200 °C to adjust the phase composition and the crystallite size, respectively. The resulting samples were characterized by Powder X-ray diffraction (PXRD), High Resolution Transmission Electron Microscopy (HRTEM), Raman/FTIR spectroscopy and magnetic measurements. Formation of the spinel phase was confirmed in all samples. The average size of the nano crystals was determined from the PXRD data and by direct particle size observation on HRTEM; both results were correlated. The mean particle size (reviewed by HRTEM) was in the range from ~ 4 to 46 nm. The results showed that the sol-gel method can be effectively used for preparation of the spinel chromite nano particles embedded in the silica matrix and the particle size is driven by the type of the cation A2+ in the spinel structure and the temperature of the final heat treatment. Magnetic properties of the nano crystals were found to be just moderately modified in comparison to the bulk phases.

Keywords: sol-gel method, nanocomposites, Rietveld refinement, Raman spectroscopy, Fourier transform infrared spectroscopy, magnetic properties, spinel, chromite

Procedia PDF Downloads 211

Authors: Jessica Vasil'chuk, Elena Ivanova, Pavel Krechetov, Vladimir Litvinsky, Nadine Budantseva, Julia Chizhova, Yurij Vasil'chuk

Abstract:

Carbonate minerals’ isotopic composition is widely used as a proxy for environmental parameters of the past. Pedogenic carbonate coatings on lower surfaces of coarse rock fragments are studied in order to indicate the climatic conditions and predominant vegetation under which they were formed. The purpose of the research is to characterize the isotopic composition of carbonate pedofeatures in soils of Minusink Hollow and estimate its correlation with isotopic composition of soil pore water, precipitation, vegetation and parent material. The samples of pedogenic carbonates, vegetation, carbonate parent material, soil water and precipitation water were analyzed using the Delta-V mass spectrometer with options of a gas bench and element analyser. The soils we studied are mainly Kastanozems that are poorly moisturized, therefore soil pore water was extracted by ethanol. Oxygen and carbon isotopic composition of pedogenic carbonates was analyzed in 3 key sites. Kazanovka Khakass state national reserve, Hankul salt lake, region of Sayanogorsk aluminum smelter. Vegetation photosynthetic pathway in the region is mainly C3. δ18O values of carbonate coatings in soils of Kazanovka vary in a range from −7.49 to −10.5‰ (vs V-PDB), and the smallest value −13.9‰ corresponds the coatings found between two buried soil horizons which 14C dates are 4.6 and 5.2 kyr BP. That may indicate cooler conditions of late Holocene than nowadays. In Sayanogorsk carbonates’ δ18O range is from −8.3 to −11.1‰ and near the Hankul Lake is from −9.0 to −10.2‰ all ranges are quite similar and may indicate coatings’ uniform formation conditions. δ13C values of carbonate coatings in Kazanovka vary from −2.5 to −6.7‰, the highest values correspond to the soils of Askiz and Syglygkug rivers former floodplains. For Sayanogorsk the range is from −4.9 to −6.8‰ and for Hankul from −2.3 to −5.7‰, where the highest value is for the modern salt crust. δ13C values of coatings strongly decrease from inner (older) to outer (younger) layers of coatings, that can indicate differences connected with the diffusion of organic material. Carbonate parent material δ18O value in the region vary from −11.1 to −12.0‰ and δ13C values vary from −4.9 to −5.7‰. Soil pore water δ18O values that determine the oxygen isotope composition of carbonates vary due to the processes of transpiration and mixing in the studied sites in a wide range of −2.0 to −13.5‰ (vs V-SMOW). Precipitation waters show δ18O values from -6.6‰ in May and -19.0‰ in January (snow) due to the temperature difference. The main conclusions are as follows: pedogenic carbonates δ13C values (−7…−2,5‰) show no correlation with modern C3 vegetation δ13C values (−30…−26‰), expected values under such vegetation are (−19…−15‰) but are closer to C4 vegetation. Late Holocene climate for the Minusinsk Hollow according to obtained data on isotope composition of carbonates and soil pore water chemical composition was dryer and cooler than present, that does not contradict with paleocarpology data obtained for the region. The research was supported by Russian Science Foundation (grant №14-27-00083).

Keywords: carbon, oxygen, pedogenic carbonates, South Siberia, stable isotopes

Procedia PDF Downloads 291