Search results for: practical chemistry

Authors: Ming-Han Tsai, Chihpin Huang

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Electrochemical oxidation of ammonia (AEO) is one of the highly efficient and environmentally friendly methods for NH₃ removal from wastewater. Recently, researchers have focused on non-Pt-based electrodes (n-PtE) for AEO, aiming to evaluate the feasibility of these low-cost electrodes for future practical applications. However, for most n-PtE, NH₃ is oxidized mainly to nitrate ion NO₃⁻ instead of the desired nitrogen gas N₂, which requires further treatment to remove excess NO₃⁻. Therefore, developing a high N₂ conversion electrode for AEO is highly urgent. In this study, we fabricated various Cu₂O/Ni foam (NF) electrodes by electrodeposition of Cu on NF. The Cu plating bath contained different additives, including cetyltrimethylammonium chloride (CTAC), sodium dodecyl sulfate (SDS), polyamide acid (PAA), and sodium alginate (SA). All the prepared electrodes were physically and electrochemically investigated. Batch AEO experiments were conducted for 3 h to clarify the relation between electrode structures and N₂ selectivity. The SEM and XRD results showed that crystalline platelets-like Cu₂O, particles-like Cu₂O, cracks-like Cu₂O, and sheets-like Cu₂O were formed in the Cu plating bath by adding CTAC, SDS, PAA, and SA, respectively. For electrochemical analysis, all Cu₂O/NF electrodes revealed a higher current density (2.5-3.2 mA/cm²) compared to that without additives modification (1.6 mA/cm²). At a constant applied potential of 0.95 V (vs Hg/HgO), the Cu₂O sheet (51%) showed the highest N₂ selectivity, followed by Cu₂O cracks (38%), Cu₂O particles (30%), and Cu₂O platelet (18%) after 3 h reaction. Our result demonstrated that the selectivity of N₂ during AEO was surface structural dependent.

Keywords: ammonia, electrooxidation, selectivity, cuprous oxide, Ni foam

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Authors: Tien-Li Chang, Huang-Chi Huang, Zhao-Chi Chen, Wun-Yi Chen

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The droplet-based microfluidic are used as micro-reactors for chemical and biological assays. Hence, the precise addition of reagents into the droplets is essential for this function in the scope of lab-on-a-chip applications. To obtain the characteristics (size, velocity, pressure, and frequency of production) of droplets, this study describes an integrated on-chip method of real-time signal detection. By controlling and manipulating the fluids, the flow behavior can be obtained in the droplet-based microfluidics. The detection method is used a type of infrared sensor. Through the varieties of droplets in the microfluidic devices, the real-time conditions of velocity and pressure are gained from the sensors. Here the microfluidic devices are fabricated by polydimethylsiloxane (PDMS). To measure the droplets, the signal acquisition of sensor and LabVIEW program control must be established in the microchannel devices. The devices can generate the different size droplets where the flow rate of oil phase is fixed 30 μl/hr and the flow rates of water phase range are from 20 μl/hr to 80 μl/hr. The experimental results demonstrate that the sensors are able to measure the time difference of droplets under the different velocity at the voltage from 0 V to 2 V. Consequently, the droplets are measured the fastest speed of 1.6 mm/s and related flow behaviors that can be helpful to develop and integrate the practical microfluidic applications.

Keywords: microfluidic, droplets, sensors, single detection

Procedia PDF Downloads 478

Authors: Ramazan Livaoğlu, Tufan Çakır

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The performance of rectangular tanks during earthquakes has been observed to depend significantly on the existence of water in the container and the presence of the backfill acting on tank wall. Therefore, in design of rectangular tanks, the topics of fluid-structure-backfill interactions and determination of modal characteristics of the interaction system have traditionally been one of the great theoretical and practical controversy. Although finite element method has been and will continue to be used to a significant extent in treating the response of the system, experimental verification of numerical models remains prerequisite for their adoption and reliable application in practice. Thus, in this study, the numerical and experimental investigations were performed on the backfill-exterior wall-fluid interaction system. Firstly, three dimensional finite element model (3D-FEM) was developed to acquire modal frequencies and mode shapes of the system by means of ANSYS. Secondly, a series of in-situ tests were fulfilled to define modal characteristics of same system to determine the applicability of the FEM to a real physical situation under field conditions. Finally, comparing the theoretical predictions from the model to results from experimental measurement, a close agreement was found between theory and experiment. Thus, it can be easily stated that experimental verification provides strong support for the use of proposed model in further investigations.

Keywords: fluid-structure interaction, modal analysis, rectangular tank, soil structure interaction

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Authors: Gayathri Sadanala, Shibam Pokhrel, Owen Murphy

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In the ever-evolving landscape of education, Virtual Reality (VR) environments offer a promising avenue for enhancing student engagement and learning experiences. However, understanding and predicting student behavior within these immersive settings remain challenging tasks. This paper presents a comprehensive study on the predictive modeling of student behavior in VR using machine learning techniques. We introduce a rich data set capturing student interactions, movements, and progress within a VR orientation program. The dataset is divided into training and testing sets, allowing us to develop and evaluate predictive models for various aspects of student behavior, including engagement levels, task completion, and performance. Our machine learning approach leverages a combination of feature engineering and model selection to reveal hidden patterns in the data. We employ regression and classification models to predict student outcomes, and the results showcase promising accuracy in forecasting behavior within VR environments. Furthermore, we demonstrate the practical implications of our predictive models for personalized VR-based learning experiences and early intervention strategies. By uncovering the intricate relationship between student behavior and VR interactions, we provide valuable insights for educators, designers, and developers seeking to optimize virtual learning environments.

Keywords: interaction, machine learning, predictive modeling, virtual reality

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Authors: Ibrahim A. Alkali

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There is no reservation on the outstanding contribution of patient families in restoration of hospitalised patients, hence their consideration as essential component of hospital ward regimen. The psychological and emotional support a patient requires has been found to be solely provided by the patient’s family. However, consideration of their presence as one of the major functional requirements of an inpatient setting design have always been a source of disquiet, especially in developing countries where policies, norms and protocols of healthcare administration have no consideration for the patients’ family. This have been a major challenge to the hospital ward facilities, a concern for the hospital administration and patient management. The study therefore is aimed at obtaining a consensus opinion on the best approach for family integration in the design of an inpatient setting.  A one day visioning charrette involving Architects, Nurses, Medical Doctors, Healthcare assistants and representatives from the Patient families was conducted with the aim of arriving at a consensus opinion on practical design approach for sustainable family integration. Patient’s family are found to be decisive character of hospital ward regimen that cannot be undermined. However, several challenges that impede family integration were identified and subsequently a recommendation for an ideal approach. This will serve as a guide to both architects and hospital management in implementing much desired Patient and Family Centred Care.

Keywords: patient's family, inpatient setting, care giving, integration

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Authors: Anyia Nduka, Aslan Bin Amad Senin

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Organizational culture, strategic leadership and organizational resilience have gained significant attention in recent years. This study aims to examine the relationship between these factors and their combined influence on an organization's ability to adapt and thrive in the face of challenges and disruptions. A mixed-methods approach, combining quantitative survey data and qualitative interviews with leaders and employees from cohort organizations within the industry. The quantitative phase involves measuring organizational culture, strategic leadership behaviours, and organizational resilience using standardized scales. This study highlighted the significance of organizational culture and strategic leadership in building and sustaining organizational resilience. Preliminary findings suggest a strong positive relationship between a resilient organizational culture and strategic leadership practices. Secondly, Organizations can enhance their capacity to respond to disruptions, exploit opportunities, and achieve long-term success in a rapidly changing business environment. Furthermore, the qualitative analysis reveals several key themes that elucidate the link between organizational culture, strategic leadership, and resilience. This study contributes to the growing body of knowledge on organizational resilience and strategic leadership, providing insights and practical implications for leaders and practitioners seeking to strengthen their organizations' resilience capabilities. Further research is needed to explore the specific mechanisms and contextual factors that influence the relationship between these variables in different organizational contexts and industries.

Keywords: organizational culture, strategic leadership, organizational resilience, leadership

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Authors: Gulbakhyt Sultanova

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Business education institutions assess the progress of their students by giving them grades for courses completed and calculating a Grade Point Average (GPA). Whether the participation in these courses has led to the development of competences enabling graduates to successfully compete in the labor market should be measured using a new index: Employment Readiness Assessment (ERA). The higher the ERA, the higher the quality of education at a business school. This is applied, empirical research conducted by using a method of linear optimization. The aim of research is to identify factors which lead to the minimization of the deviation of GPA from ERA as well as to the maximization of ERA. ERA is composed of three components resulting from testing proficiency in Business English, testing work and personal skills, and job interview simulation. The quality of education is improving if GPA approximates ERA and ERA increases. Factors which have had a positive effect on quality enhancement are academic mobility of students and staff, practical-oriented courses taught by staff with work experience, and research-based courses taught by staff with research experience. ERA is a better index to measure the quality of business education than traditional indexes such as GPA due to its greater accuracy in assessing the level of graduates’ competences demanded in the labor market. Optimizing the educational process in pursuit of quality enhancement, ERA has to be used in parallel with GPA to find out which changes worked and resulted in improvement.

Keywords: assessment and evaluation, competence evaluation, education quality, employment readiness

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Authors: Chih-Hsin Lin, Shyh-Yuan Lee, Yuan-Min Lin

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For many tissue engineering applications, an important goal is to create functional tissues in-vitro, and such tissues to be viable, they have to be vascularized. Endothelial cells (EC) and endothelial progenitor cells (EPC) are promising candidates for vascularization. However, both of them have limited expansion capacity and autologous cells currently do not exist for either ECs or EPCs. Therefore, we use bone marrow mesenchymal stem cells (MSC) as a source material for ECs. Growth supplements are commonly used to induce MSC differentiation, and further improvements in differentiation conditions can be made by modifying the cell's growth environment. An example is pre-treatment of the growth dish with gas plasma, in order to modify the surface functional groups of the material that the cells are seeded on. In this work, we compare the effects of different gas plasmas on the growth and differentiation of MSCs. We treat the dish with different plasmas (CO2, N2, and O2) and then induce MSC differentiation with endothelial growth medium-2 (EGM-2). We find that EGM-2 by itself upregulates EC marker CD31 mRNA expression, but not VEGFR2, CD34, or vWF. However, these additional EC marker expressions were increased for cells seeded on plasma treated substrates. Specifically, for EC markers, we found that N2 plasma treatment upregulated CD31 and VEGFR-2 mRNA expressions; CO2 plasma treatment upregulated CD34 and vWF mRNA expressions. The osteogenic markers ALP and osteopontin mRNA expressions were markedly enhanced on all plasma-treated dishes. We also found that plasma treatment in conjunction with EGM-2 growth medium can enhance MSCs differentiation into endothelial-like cells and osteogenic-like cells. Our work shows that the effect of the growth medium (EGM-2) on MSCs differentiation is influenced by the plasma modified surface chemistry of the substrate. In conclusion, plasma surface modification can enhance EGM-2 effectiveness and induced both endothelial and osteogenic differentiation. Our findings provide a method to enhance EGM-2 based cell differentiation, with consequences for tissue engineering and stem cell biology applications.

Keywords: endothelial differentiation, EGM-2, osteogenesis, plasma treatment, surface modification

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Authors: Najie Hassanzade, Mohammad Rabbani Khorasgani

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Dairy products have been regarded as the natural source of lactic acid bacteria with potential characteristics of probiotics; therefore, a lot of research and practical works have been carried out about the isolation of lactic acid bacteria (LAB) from dairy products, especially traditional yogurt and related products. Interest in traditional dairy products continues in the area of isolation of new LAB that can complement or replace currently used starters and/or that can be candidates as beneficial microorganisms for prevention or treatment purposes. In this perspective, such products are potentially good candidates for isolating new strains of probiotics. On the other hand, some infectious diseases such as salmonellosis have expressed resistance against many antibiotics; therefore, many attempts have been performed to use an alternative approach to overcome antibiotic resistance. The current research focuses on the isolation of LAB from dairy products, especially traditional dairy products and screening of them for anti-Salmonella activities. Twenty-five samples, including 15 sheep milk samples, one camel milk sample and seven cow milk samples from different areas of Iran and 2 yogurt samples from Herat, Afghanistan are collected. 20 bacteria are isolated by culturing the samples on MRS agar specific medium; among them 4 Lactobacillus strains, including 3L. plantarum strains and one L.gasseri strain, are identified by analyzing the biochemical tests and PCR tests in which 27F and 1492R primers are used. Then, their effects against Salmonella typhimurium using the well-diffusion method are evaluated.

Keywords: lactic acid bacteria, probiotics, dairy products Salmonella

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Authors: René Čechmánek, Vladan Prachař, Ludvík Lederer, Jiří Loskot

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Thin-walled elements with a matrix set on a base of high-valuable Portland cement with dispersed reinforcement from alkali-resistant glass fibres are used in a range of applications as claddings of buildings and infrastructure constructions as well as various architectural elements of residential buildings. Even if their elementary thickness and therefore total weight is quite low, architects and building companies demand on even further decreasing of the bulk density of these fibre-cement elements for the reason of loading elimination of connected superstructures and easier assembling in demand conditions. By the means of various kinds of light-weight aggregates it is possible to achieve light-weighing of thin-walled fibre-cement composite elements. From the range of possible fillers with different material properties granulated expanded glass worked the best. By the means of laboratory testing an effect of two fillers based on expanded glass on the fibre reinforced cement composite was verified. Practical applicability was tested in the production of commonly manufactured glass fibre reinforced concrete elements, such as channels for electrical cable deposition, products for urban equipment and especially various cladding elements. Even if these are not structural elements, it is necessary to evaluate also strength characteristics and resistance to environment for their durability in certain applications.

Keywords: fibre-cement composite, granulated expanded glass, light-weighing

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Authors: Robin C. Ladwig

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The future of work becomes less predictable, which requires increasing the adaptability of organizations to social and work changes. Society is transforming regarding gender identity in the sense that more people come forward to identify as trans and gender diverse (TGD). Organizations are ill-equipped to provide a safe and encouraging work environment by lacking inclusive organizational structures. The qualitative multi-method research about TGD inclusivity in the workplace explores the enablers and barriers for TGD individuals to satisfactory engage in the work environment and organizational culture. Furthermore, these TGD insights are analyzed about their organizational implications and awareness from a leadership and management perspective. The semi-structured online interviews with TGD individuals and the photo-elicit open-ended questionnaire addressed to leadership and management in diversity, career development, and human resources have been analyzed with a critical grounded theory approach. Findings demonstrated the significance of TGD voices, the support of leadership and management, as well as the synergy between voices and leadership. Hence, it indicates practical implications such as the revision of exclusive language used in policies, data collection, or communication and reconsideration of organizational decision-making by leaders to include TGD voices.

Keywords: future of work, occupational identity, organisational decision-making, trans and gender diverse identity

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Authors: Negar Ganjouhaghighi, Amirali Dolatshahi

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The origin of most risks of a mega project usually takes place in the phases before closing the contract. As a practical point of view, using project risk management techniques for preparing a proposal is not a total solution for managing the risks of a contract. The objective of this paper is to cover all those activities associated with risk management of a mega project sale’s processes; from entrance to a new market to awarding activities and the review of contract performance. In this study, the risk management happens in six consecutive steps that are divided into three distinct but interdependent phases upstream of the award of the contract: pre-tendering, tendering and closing. In the first step, by preparing standard market risk report, risks of the new market are identified. The next step is the bid or no bid decision making based on the previous gathered data. During the next three steps in tendering phase, project risk management techniques are applied for determining how much contingency reserve must be added or reduced to the estimated cost in order to put the residual risk to an acceptable level. Finally, the last step which happens in closing phase would be an overview of the project risks and final clarification of residual risks. The sales experience of more than 20,000 MW turn-key power plant projects alongside this framework, are used to develop a software that assists the sales team to have a better project risk management.

Keywords: project marketing, risk management, tendering, project management, turn-key projects

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Authors: M. Aboudalle, Le Btth, M. Sari, F. Meftah

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In parallel with the appearance of new materials, brick masonry had and still has an essential part of the construction market today, with new technical challenges in designing bricks to meet additional requirements. Being used in structural applications, predicting the performance of clay brick masonry allows a significant cost reduction, in terms of practical experimentation. The behavior of masonry walls depends on the behavior of their elementary components, such as bricks, joints, and coatings. Therefore, it is necessary to consider it at different scales (from the scale of the intrinsic material to the real scale of the wall) and then to develop appropriate models, using numerical simulations. The work presented in this paper focuses on the mechanical characterization of the terracotta material at ambient temperature. As a result, the static Young’s modulus obtained from the flexural test shows different values in comparison with the compression test, as well as with the dynamic Young’s modulus obtained from the Impulse excitation of vibration test. Moreover, the Young's modulus varies according to the direction in which samples are extracted, where the values in the extrusion direction diverge from the ones in the orthogonal directions. Based on these results, hollow bricks can be considered as transversely isotropic bimodulus material.

Keywords: bimodulus material, hollow clay brick, ımpulse excitation of vibration, transversely isotropic material, young’s modulus

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Authors: HebatAllah Tarek, Zeyad El-Sayad, Ali F. Bakr

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Surface coating can permit the bulk materials to remain unchanged, whereas the surface functionality is engineered to afford a more required characteristic. Nano-Ceramic coatings are considered ideal coatings on materials that can significantly improve the surface properties, including anti-fouling, self-cleaning, corrosion resistance, wear resistance, anti-scratch, waterproof, anti-acid rain and anti-asphalt. Furthermore, various techniques have been utilized to fabricate a range of different ceramic coatings with more desirable properties on Nano-ceramics, which make the materials usually used in in-service environments and worth mentioning that the practical part of this study will be applied in one of the most important architectural applications due to the contamination-free conditions provided by it in the manufacturing industry. Without cleanrooms, products will become contaminated and either malfunction or infect people with bacteria. Cleanrooms are used for the manufacture of items used in computers, cars, airplanes, spacecraft, televisions, disc players and many other electronic and mechanical devices, as well as the manufacture of medicines, medical devices, and foods. The aim of this study will be to examine the Nano-ceramics on porcelain and glass panels. The investigation will be included fabrications, methods, surface properties and applications in clean rooms. The unfamiliarity in this study is using Nano-ceramics in clean rooms instead of using them on metallic materials.

Keywords: nano-ceramic coating, clean rooms, porcelain, surface properties

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Authors: Nazirah Hassan, Andrew Kendrick

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This study investigates the prevalence of perpetration behavior and victimization in juvenile correctional institutions. It investigates the dimensions of institutional environments and explores which environmental features relate to perpetration behaviors. The project focused on two hundred and eighty nine male and female young offenders aged 12 to 21 years old, in eight juvenile institutions in Malaysia. The research collected quantitative and qualitative data using a mixed-method approach. All participants completed the scale version of Direct and Indirect Prisoner behavior Checklist (DIPC-SCALED) and the Measuring the Quality of Prison life (MQPL). In addition, twenty-four interviews were carried out which involved sixteen residents and eight institutional staff. The findings showed that 95 per cent reported at least one behavior indicative of perpetration, and 99 per cent reported at least one behavior indicative of victimization in the past month. The DIPC-SCALED scored significantly higher on the verbal sub-scale. In addition, factors such as harmony, staff professionalism, security, family and wellbeing showed significant relation to the perpetration behavior. In the interviews, the residents identified circumstances, which affected their behavior within the institutions. This reflected the choices and decisions about how to confront the institutional life. These findings are discussed in terms of existing literature and their practical implications are considered.

Keywords: juvenile institutions, incarcerated offenders, perpetration, victimization

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Authors: N. Gigauri, V. Kukhalashvili, A. Surmava, L. Intskirveli, L. Gverdtsiteli

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Tbilisi, a large city of the South Caucasus, is a junction point connecting Asia and Europe, Russia and republics of the Asia Minor. Over the last years, its atmosphere has been experienced an increasing anthropogenic load. Numerical modeling method is used for study of Tbilisi atmospheric air pollution. By means of 3D non-linear non-steady numerical model a peculiarity of city atmosphere pollution is investigated during background western light air. Dust concentration spatial and time changes are determined. There are identified the zones of high, average and less pollution, dust accumulation areas, transfer directions etc. By numerical modeling, there is shown that the process of air pollution by the dust proceeds in four stages, and they depend on the intensity of motor traffic, the micro-relief of the city, and the location of city mains. In the interval of time 06:00-09:00 the intensive growth, 09:00-15:00 a constancy or weak decrease, 18:00-21:00 an increase, and from 21:00 to 06:00 a reduction of the dust concentrations take place. The highly polluted areas are located in the vicinity of the city center and at some peripherical territories of the city, where the maximum dust concentration at 9PM is equal to 2 maximum allowable concentrations. The similar investigations conducted in case of various meteorological situations will enable us to compile the map of background urban pollution and to elaborate practical measures for ambient air protection.

Keywords: air pollution, dust, numerical modeling, urban

Procedia PDF Downloads 172

Authors: Alejandra Yanez, Teresa Benavides, Zita Lopez

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Even before COVID-19, one of the most important challenges that Higher Education faces today is the need for innovative educational methodologies and flexibility. We could all agree that one of the objectives of Higher Education is to provide students with a variety of intellectual and practical skills that, at the same time, will help them develop competitive advantages such as adaptation and critical thinking. Among the strategic objectives of Universidad de Monterrey (UDEM) has been to provide flexibility and satisfaction to students in the delivery modes of the academic offer. UDEM implemented a methodology that combines face to face with synchronous and asynchronous as delivery modes. UDEM goal, in this case, was to implement new technologies and different teaching methodologies that will improve the students learning experience. In this study, the experience of students during courses implemented in new delivery mode was compared with students in courses with traditional delivery modes. Students chose openly either way freely. After everything students around the world lived in 2020 and 2021, one can think that the face to face (traditional) delivery mode would be the one chosen by students. The results obtained in this study reveal that both delivery modes satisfy students and favor their learning process. We will show how the combination of delivery modes provides flexibility, so the proposal is that universities can include them in their academic offer as a response to the current student's learning interests and needs.

Keywords: flexibility, new delivery modes, student satisfaction, academic offer

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Authors: Prabhashini Wijewantha

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This study looks at the impact of protean career attitude of employees on their career success and next it looks at the mediation effect of career insights on the above relationship. Career success is defined as the accomplishment of desirable work related outcomes at any point in person’s work experiences over time and it comprises of two sub variables, namely, career satisfaction and perceived employability. Protean career attitude was measured using the eight items from the Self Directedness subscale of the Protean Career Attitude scale developed by Briscoe and Hall, where as career satisfaction was measured by the three item scale developed by Martine, Eddleston, and Veiga. Perceived employability was also evaluated using three items and career insight was measured using fourteen items that were adapted and used by De Vos and Soens. Data were collected from a sample of 300 mid career executives in Sri Lanka deploying the survey strategy and data were analyzed using the SPSS and AMOS software version 20.0. A preliminary analysis of data was initially performed where data were screened and reliability and validity were ensured. Next a simple regression analysis was performed to test the direct impact of protean career attitude on career success and the hypothesis was supported. The Baron and Kenney’s four steps, three regressions approach for mediator testing was used to calculate the mediation effect of career insight on the above relationship and a partial mediation was supported by the data. Finally theoretical and practical implications are discussed.

Keywords: career success, career insight, mid career MBAs, protean career attitude

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Authors: Xi-Wen Xiao, Tzy-Rong Lin, Chien-Hao Liu

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Ventilated acoustic metamaterials have attracted considerable research attention due to their low-frequency absorptions and efficient fluid ventilations. In this research, a wideband acoustic metamaterial with auditory filtering ability and efficient ventilation capacity were proposed. In contrast to a conventional Fano-like resonator, a Fano-like resonator composed of a resonant unit and two nonresonant units with a large opening area of 68% for fluid passages was developed. In addition, the coupling mechanism to improve the narrow bandwidths of conventional Fano-resonance-based meta-materials was included. With a suitable design, the output sound waves of the resonant and nonresonant states were out of phase to achieve sound absorptions in the far fields. Therefore, three-element and five-element coupled Fano-like metamaterials were designed and simulated with the help of the finite element software to obtain the filtering fractional bandwidths of 42.5% and 61.8%, respectively. The proposed approach can be extended to multiple coupled resonators for obtaining ultra-wide bandwidths and can be implemented with 3D printing for practical applications. The research results are expected to be beneficial for sound filtering or noise reductions in duct applications and limited-volume spaces.

Keywords: fano resonance, noise reduction, resonant coupling, sound filtering, ventilated acoustic metamaterial

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Authors: Abdulbaset Saad, Adel Younis, Zuomin Dong

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For design optimization with high-dimensional expensive problems, an effective and efficient optimization methodology is desired. This work proposes a series of modification to the Differential Evolution (DE) algorithm for solving computation Intensive Black-Box Problems. The proposed methodology is called Radial Basis Meta-Model Algorithm Assisted Differential Evolutionary (RBF-DE), which is a global optimization algorithm based on the meta-modeling techniques. A meta-modeling assisted DE is proposed to solve computationally expensive optimization problems. The Radial Basis Function (RBF) model is used as a surrogate model to approximate the expensive objective function, while DE employs a mechanism to dynamically select the best performing combination of parameters such as differential rate, cross over probability, and population size. The proposed algorithm is tested on benchmark functions and real life practical applications and problems. The test results demonstrate that the proposed algorithm is promising and performs well compared to other optimization algorithms. The proposed algorithm is capable of converging to acceptable and good solutions in terms of accuracy, number of evaluations, and time needed to converge.

Keywords: differential evolution, engineering design, expensive computations, meta-modeling, radial basis function, optimization

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Authors: Jing Wang, Yong Wang

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For organizational development, employee well-being is critical and has been influenced deeply by character strengths. Therefore, investigating the relationship between character strengths and employee well-being and its inner mechanism is crucial. In this study, we explored the features of Chinese employees' character strengths, studied the relationship between character strengths and employees' subjective well-being, work well-being and psychological well-being respectively, and examined the mediating effect of work-family relationship (both enrichment and conflict). An online survey was conducted. The results showed that: (1) The top five character strengths of Chinese employees were gratitude, citizenship, kindness, appreciation of beauty and excellence, justice, while the bottom five ones were creativity, authenticity, bravery, spirituality, open-mindedness. (2) Subjective well-being was significantly correlated to courage, humanity, transcendence and justice. Work well-being was significantly correlated to wisdom, courage, humanity, justice and transcendence. Psychological well-being was significantly correlated to all the above five character strengths and temperance. (3) Wisdom and humanity influenced Chinese employees’ subjective well-being through work-family enrichment. Justice enhanced psychological well-being via work-family enrichment; meanwhile, it also played a positive role in subjective well-being, work well-being, and psychological well-being by decreasing the family-work conflict. At the end of this paper, some theoretical and practical contributions to organizational management were further discussed.

Keywords: character strengths, work-family conflict, work-family enrichment, employee well-being, work well-being

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Authors: Guorong Sui, Xingwei Jia, Fei Tong, Xiumin Gao

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Camera calibration is a fundamental issue of high precision noncontact measurement. And it is necessary to analyze and study the reliability and application range of its linear model which is often used in the camera calibration. According to the imaging features of monocular cameras, a camera model which is based on the image pixel coordinates and three dimensional space coordinates is built. Using our own customized template, the image pixel coordinate is obtained by the subpixel corner detection method. Without considering the aberration of the optical system, the feature extraction and linearity analysis of the line segment in the template are performed. Moreover, the experiment is repeated 11 times by constantly varying the measuring distance. At last, the linearity of the camera is achieved by fitting 11 groups of data. The camera model measurement results show that the relative error does not exceed 1%, and the repeated measurement error is not more than 0.1 mm magnitude. Meanwhile, it is found that the model has some measurement differences in the different region and object distance. The experiment results show this linear model is simple and practical, and have good linearity within a certain object distance. These experiment results provide a powerful basis for establishment of the linear model of camera. These works will have potential value to the actual engineering measurement.

Keywords: camera linear model, geometric imaging relationship, image pixel coordinates, three dimensional space coordinates, sub-pixel corner detection

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Authors: Samuel Abebe Ebebo

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Scale precipitation causes a major issue for geothermal power plants because it reduces the production rate of geothermal energy. Each geothermal power plant's different chemical and physical conditions can cause the scale to precipitate under a particular set of fluid-rock interactions. Depending on the mineral, it is possible to have scale in the production well, steam separators, heat exchangers, reinjection wells, and everywhere in between. The scale consists mainly of smectite and trace amounts of chlorite, magnetite, quartz, hematite, dolomite, aragonite, and amorphous silica. The smectite scale is one of the difficult scales at injection wells in geothermal power plants. X-ray diffraction and chemical composition identify this smectite as Stevensite. The characteristics and the scale of each injection well line are different depending on the fluid chemistry. The smectite scale has been widely distributed in pipelines and surface plants. Mineral water equilibrium showed that the main factors controlling the saturation indices of smectite increased pH and dissolved Mg concentration due to the precipitate on the equipment surface. This study aims to characterize the scales and geothermal fluids collected from the Onuma geothermal power plant in Akita Prefecture, Japan. Field tests were conducted on October 30–November 3, 2021, at Onuma to determine the pH control methods for preventing magnesium silicate scaling, and as exemplified, the formation of magnesium silicate hydrates (M-S-H) with MgO to SiO2 ratios of 1.0 and pH values of 10 for one day has been studied at 25 °C. As a result, M-S-H scale formation could be suppressed, and stevensite formation could also be suppressed when we can decrease the pH of the fluid by less than 8.1, 7.4, and 8 (at 97 °C) in the fluid from O-3Rb and O-6Rb, O-10Rg, and O-12R, respectively. In this context, the scales and fluids collected from injection wells at a geothermal power plant in Japan were analyzed and characterized to understand the formation conditions of Mg-silicate scales with on-site synthesis experiments. From the results of the characterizations and on-site synthesis experiments, the inhibition method of their scale formation is discussed based on geochemical modeling in this study.

Keywords: magnesium silicate, scaling, inhibitor, geothermal power plant

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Authors: Chen T. Chen, Hui L. Cheng

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Due to the different knowledge, experience and expertise of experts, they usually provide the different opinions in the group decision-making process. Therefore, it is an important issue to reach the group consensus of opinions of experts in group multiple-criteria decision-making (GMCDM) process. Because the subjective opinions of experts always are fuzziness and uncertainties, it is difficult to use crisp values to describe the real opinions of experts or decision-makers. It is reasonable for experts to use the linguistic variables to express their opinions. The hesitant fuzzy set are extended from the concept of fuzzy sets. Experts use the hesitant fuzzy sets can be flexible to describe their subjective opinions. In order to aggregate the hesitant fuzzy linguistic variables of all experts effectively, an adjustment method based on distance function will be presented in this paper. Based on the opinions adjustment method, this paper will present an effective approach to adjust the hesitant fuzzy linguistic variables of all experts to reach the group consensus. Then, a new hesitant linguistic GMCDM method will be presented based on the group consensus of hesitant fuzzy linguistic variables. Finally, an example will be implemented to illustrate the computational process to enhance the practical value of the proposed model.

Keywords: group multi-criteria decision-making, linguistic variables, hesitant fuzzy linguistic variables, distance function, group consensus

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Authors: Tia Kristian Tajnšek, Matjaž Mazaj, Nataša Zabukovec Logar

Abstract:

Metal-organic frameworks (MOFs) with their specific properties and the possibility of tuning the structure represent excellent candidates for use in the biomedical field. Their advantage lies in large pore surfaces and volumes, as well as the possibility of using bio-friendly or bioactive constituents. So-called bioMOFs are representatives of MOFs, which are constructed from at least one biomolecule (metal, a small bioactive molecule in metal clusters and/or linker) and are intended for bio-application (usually in the field of medicine; most commonly drug delivery). When designing a bioMOF for biomedical applications, we should adhere to some guidelines for an improved toxicological profile of the material. Such as (i) choosing an endogenous/nontoxic metal, (ii) GRAS (generally recognized as safe) linker, and (iii) nontoxic solvents. Design and synthesis of bioNICS-1 (bioMOF of National Institute of Chemistry Slovenia – 1) consider all these guidelines. Zinc (Zn) was chosen as an endogenous metal with an agreeable recommended daily intake (RDI) and LD50 value, and ascorbic acid (Vitamin C) was chosen as a GRAS and active linker. With these building blocks, we have synthesized a bioNICS-1 material. The synthesis was done in ethanol using a solvothermal method. The synthesis protocol was further optimized in three separate ways. Optimization of (i) synthesis parameters to improve the yield of the synthesis, (ii) input reactant ratio and addition of specific modulators for production of larger crystals, and (iii) differing of the heating source (conventional, microwave and ultrasound) to produce nano-crystals. With optimization strategies, the synthesis yield was increased. Larger crystals were prepared for structural analysis with the use of a proper species and amount of modulator. Synthesis protocol was adjusted to different heating sources, resulting in the production of nano-crystals of bioNICS-1 material. BioNICS-1 was further activated in ethanol and structurally characterized, resolving the crystal structure of new material.

Keywords: ascorbic acid, bioMOF, MOF, optimization, synthesis, zinc ascorbate

Procedia PDF Downloads 130

Authors: Rashmi Dubey

Abstract:

The study aims at investigating the onset of thermal convection in an inclined porous layer saturated with a non-Newtonian fluid. The layer is infinitely extended and has a finite width confined between two boundaries with constant pressure conditions, where the lower one is maintained at a higher temperature. Over the years, this area of research has attracted many scientists and researchers, for it has a plethora of applications in the fields of sciences and engineering, such as in civil engineering, geothermal sites, petroleum industries, etc.Considering the possibilities in a practical scenario, an inclined porous layer is considered, which can be used to develop a generalized model applicable to any inclination. Using the isobaric boundaries, the hydrodynamic boundary conditions are derived for the power-law model and are used to obtain the basic state flow. The convection in the basic state flow is driven by the thermal buoyancy in the flow system and is carried away further due to hydrodynamic boundaries. A linear stability analysis followed by a normal-mode analysis is done to investigate the onset of convection in the buoyancy-driven flow. The analysis shows that the convective instability is always initiated by the non-traveling modes for the Newtonian fluid, but prevails in the form of oscillatory modes, for up to a certain inclination of the porous layer. However, different behavior is observed for the dilatant and pseudoplastic fluids.

Keywords: thermal convection, linear stability, porous media flow, Inclined porous layer

Procedia PDF Downloads 113

Authors: Daming Xu, Yuanyuan Wang

Abstract:

Abstract: Under the trend of rapid expansion of urbanization, the motorized urban characteristics become more and more obvious, and the walkability of urban space is seriously affected. The construction of walkability of space, as the main mode of travel for the elderly in their daily lives, has become more and more important in the current social context of serious aging. Settlement is the most basic living unit of residents, and daily shopping, medical care, and other daily trips are closely related to the daily life of the elderly. Therefore, it is of great practical significance to explore the impact of built environment on elderly people's daily walking trips at the settlement level for the construction of pedestrian-friendly settlements for the elderly. The study takes three typical settlements in Harbin Daoli District in three different periods as examples and obtains data on elderly people's walking trips and built environment characteristics through field research, questionnaire distribution, and internet data acquisition. Finally, correlation analysis and multinomial logistic regression model were applied to analyze the influence mechanism of built environment on elderly people's walkability based on the control of personal attribute variables in order to provide reference and guidance for the construction of walkability for elderly people in built environment in the future.

Keywords: built environment, elderly, walkability, multinomial logistic regression model

Procedia PDF Downloads 67

Authors: Syahruddin Sumardi Samindjaya, Indra Fajar Alamsyah, Junaidah Hashim

Abstract:

Purpose: This study attempts to explore and presents a proposed recruitment model in Islamic university which aligned with holistic role. Design/methodology/approach: It is a conceptual paper in nature. In turn, this study is designed to utilize exploratory approach. Literature and document review that related to this topic are used as the methods to analyse the content found. Findings: Recruitment for any organization is fundamental to achieve its goal effectively. Staffing in universities is vital due to the important role of lecturers. Currently, Islamic universities still adopt the common process of recruitment for their academic staffs. Whereas, they have own characteristics which are embedded in their institutions. Furthermore, the FCWC (Foundation, Capability, Worldview and Commitment) model of recruitment proposes to suit the holistic character of Islamic university. Research limitation/implications: Further studies are required to empirically validate the concept through systematic investigations. Additionally, measuring this model by a designed means is appreciated. Practical implications: The model provides the map and alternative tool of recruitment for Islamic universities to determine the process of recruitment which can appropriate their institutions. In addition, it also allows stakeholders and policy makers to consider regarding Islamic values that should inculcate in the Islamic higher learning institutions. Originality/value: This study initiates a foundational contribution for an early sequence of research.

Keywords: academic staff, Islamic values, recruitment model, university

Procedia PDF Downloads 171

Authors: Brian Romansky

Abstract:

There are many practical, commercially available robots and semi-autonomous systems that are currently available for use in a wide variety of construction tasks. Adoption of these technologies has the potential to reduce the time and cost to deliver a project, reduce variability and risk in delivery time, increase quality, and improve safety on the job site. These benefits come with a cost for equipment rental or contract fees, access to specialists to configure the system, and time needed for set-up and support of the machines while in use. Calculation of the net ROI (Return on Investment) requires detailed information about the geometry of the site, the volume of work to be done, the overall project schedule, as well as data on the capabilities and past performance of available robotic systems. Assembling the required data and comparing the ROI for several options is complex and tedious. Many project managers will only consider the use of a robot in targeted applications where the benefits are obvious, resulting in low levels of adoption of automation in the construction industry. This work demonstrates how data already resident in many BIM (Building Information Model) projects can be used to automate ROI estimation for a sample set of commercially available construction robots. Calculations account for set-up and operating time along with scheduling support tasks required while the automated technology is in use. Configuration parameters allow for prioritization of time, cost, or safety as the primary benefit of the technology. A path toward integration and use of automatic ROI calculation with a database of available robots in a BIM platform is described.

Keywords: automation, BIM, robot, ROI.

Procedia PDF Downloads 78

Authors: Chariya Laohavich

Abstract:

At the current, the trends in the lung disease at a university hospital are the treat and diagnosis by bronchoscopy. Bronchoscopic cryotherapy is a long time procedure 1-4 hours. The cryo probe is sensitive and easy to be damaged and expensive. We have this study management for protection the cryo probe, user satisfaction and qualities work. This study conducted in 4 stages: stage 1 for a survey of problems and assessment of user’s needs; stage 2 for designing and developing the Rama-chest cryo arm for a bronchoscopy process; stage 3 for test-implementing the Rama-chest cryo arm in real situations, studying its problems and obstacles, and evaluating the user satisfaction; and stage 4 for an overall assessment and improvement. The sample used in this study consisted of a total of 15 Ramathipbodi Hospital’s Bronchoscopist and bronchoscopist’s nurse who had used the Rama-chest cryo arm for bronchoscopic cryotherapy from January to June 2016. Objective: To study efficacy and user satisfaction on the Rama-chest cryo arm innovation for bronchoscopic cryotherapy. Data were collected using a Rama-chest cryo arm satisfaction assessment form and analysed based on mean and standard deviation. Result is the Rama-chest cryo arm was an innovation that accommodated during bronchoscopic cryotherapy. The subjects rated this the cryo arm as being most satisfactory (M = 4.86 ± , SD 0.48. Therefore we have developed a cryo arm that uses local material, practical and economic. Our innovation is not only flexible and sustainable development but also lean and seamless. This produced device can be used as effectively as the imported one, and thus can be eventually substituted.

Keywords: efficacy, satisfaction, Rama-chest cryo arm, innovation, bronchoscopic cryotherapy

Procedia PDF Downloads 236