Search results for: test methods

Authors: Lojain Suliman, Xinrong Liu, Xiaohan Zhou

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Since most tunnels are built in crowded metropolitan settings, the excavation process must take place in highly condensed locations, including high-density cities. In this way, the tunnels are typically located close together, which leads to more interaction between the parallel existing tunnels, and this, in turn, leads to more settlement. This research presents an examination of the impact of a large-scale tunnel excavation on two forms of settlement: surface settlement and settlement surrounding the tunnel. Additionally, research has been done on the properties of interactions between two and three parallel tunnels. The settlement has been evaluated using three primary techniques: theoretical modeling, numerical simulation, and data monitoring. Additionally, a parametric investigation on how distance affects the settlement characteristic for parallel tunnels with short distances has been completed. Additionally, it has been observed that the sequence of excavation has an impact on the behavior of settlements. Nevertheless, a comparison of the model test and numerical simulation yields significant agreement in terms of settlement trend and value. Additionally, when compared to the FEM study, the suggested analytical solution exhibits reduced sensitivity in the settlement prediction. For example, the settlement of the small tunnel diameter does not appear clearly on the settlement curve, while it is notable in the FEM analysis. It is advised, however, that additional studies be conducted in the future employing analytical solutions for settlement prediction for parallel tunnels.

Keywords: settlement, FEM, analytical solution, parallel tunnels

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Authors: Masoud Soltanialvar, Ali Bagherpour

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The aim of this study was to determinate the variety of Anaplasma species among sheep of khouzestan province, Iran. From April 2013 to June 2013, a total of 200 blood samples were collected via the jugular vein from healthy sheep (100), randomly. The extracted DNA from blood cells were amplified by Anaplasma-all primers, which amplify an approximately 1468bp DNA fragment from region of 16S rRNA gene from various members of the genus Anaplasma. For raising the test sensivity, the PCR products were amplified with the primers, which were designed from the region flanked by the first primers. The amplified nested PCR product had an expected PCR product with 345 nucleotides in length. In 100 sheep blood samples, 7 samples were Anaplasma spp. positive by first PCR and nested PCR. The results showed that 2 of total 100 blood samples (2%) were A.phagocytophilum positive by specific nested PCR based on 16S rRNA gene. The extracted DNA from positive Anaplasma spp. samples were amplified by Anaplasma ovis specific primers, which amplify an approximately 866bp DNA fragment from region of msp4 gene. 5 out of 100 sheep blood samples (5%) were positive for Anaplasma ovis. This study is the first molecular detection of A. ovis and A.phagocytophilum from sheep in Iran.

Keywords: Iran, anaplasma species, sheep, A. ovis, A. phagocytophilum, PCR

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Authors: Raimi Abiodun Moronfolu, Anthonia Olusola Moronfolu

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The purpose of this study was to assess athlete’s preparation and quality of opponent as determinants of self-efficacy among university athletes in south-west Nigeria. The descriptive research method was employed in conducting the study. A total of 200 athletes, selected from 4 universities in South-West geopolitical zone of Nigeria through a stratified random sampling technique, were used in the study. The instrument used for data collection was a self-structured questionnaire named ‘Athletes Self-Efficacy Assessment Questionnaire (ASAQ)’. This was developed by the researchers and face validated by three experts in sports psychology. The test-retest method was used in establishing the reliability of the instrument (r=0.79). A total of 200 copies of the validated ASAQ were administered on selected respondents using the spot method. The data collected was used to develop a frequency distribution table for analysis. The descriptive statistics of percentage was used in presenting the data collected, while inferential statistics of linear regression was used in drawing inferences at a 0.05 level of significance. The findings indicated that athlete’s preparation and quality of opponent were significant determinants of self-efficacy among university athletes in South-West Nigeria.

Keywords: athletes, preparation, opponent, self-efficacy

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Authors: Rabah Younes

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The reduction of available land resources and the increased cout associated with the use of high quality materials have led to the need for local soils to be used in geotechnical construction, however; poor engineering properties of these soils pose difficulties for constructions project and need to be stabilized to improve their properties in other works unsuitable soils with low bearing capacity , high plasticity coupled with high instability are frequently encountered hence, there is a need to improve the physical and mechanical characteristics of these soils to make theme more suitable for construction this can be done by using different mechanical and chemical methods clayey soil stabilization has been practiced for sometime but mixing additives, such us cement, lime and fly ash to the soil to increase its strength.

Keywords: clay, soil stabilization, naturaln pozzolana, atterberg limits, compaction, compressive strength shear strength, curing

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Authors: Gamze Karanfil Celep, Kevser Dincer

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The effects of polymer concentration and electrospinning process parameters on the average diameters of electrospun polyacrylonitrile (PAN) nanofibers were experimentally investigated. Besides, mechanical and thermal properties of PAN nanofibers were examined by tensile test and thermogravimetric analysis (TGA), respectively. For this purpose, the polymer concentration, solution feed rate, supply voltage and tip-to-collector distance were determined as the control factors. To succeed these aims, Taguchi’s L16 orthogonal design (4 parameters, 4 level) was employed for the experimental design. Optimal electrospinning conditions were defined using the signal-to-noise (S/N) ratio that was calculated from diameters of the electrospun PAN nanofibers according to "the-smaller-the-better" approachment. In addition, analysis of variance (ANOVA) was evaluated to conclude the statistical significance of the process parameters. The smallest diameter of PAN nanofibers was observed. According to the S/N ratio response results, the most effective parameter on finding out of nanofiber diameter was determined. Finally, the Taguchi design of experiments method has been found to be an effective method to statistically optimize the critical electrospinning parameters used in nanofiber production. After determining the optimum process parameters of nanofiber production, electrical conductivity and fuel cell performance of electrospun PAN nanofibers on the carbon papers will be evaluated.

Keywords: nanofiber, electrospinning, polyacrylonitrile, Taguchi method

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Authors: Thuan Nguyen

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In the present time, data to a data-driven knowledge-based economy is the same as oil to the industrial age hundreds of years ago. Data is everywhere in vast volumes! Big data analytics is expected to help firms not only efficiently improve performance but also completely transform how they should run their business. However, employing the emergent technology successfully is not easy, and assessing the roles of big data in improving firm performance is even much harder. There was a lack of studies that have examined the impacts of big data analytics on organizational performance. This study aimed to fill the gap. The present study suggested using firms’ intellectual capital as a proxy for big data in evaluating its impact on organizational performance. The present study employed the Value Added Intellectual Coefficient method to measure firm intellectual capital, via its three main components: human capital efficiency, structural capital efficiency, and capital employed efficiency, and then used the structural equation modeling technique to model the data and test the models. The financial fundamental and market data of 100 randomly selected publicly listed firms were collected. The results of the tests showed that only human capital efficiency had a significant positive impact on firm profitability, which highlighted the prominent human role in the impact of big data technology.

Keywords: big data, big data analytics, intellectual capital, organizational performance, value added intellectual coefficient

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Authors: Dita Mayasari, Zahrina Mardina, Riki Siswanto, Agresta Ifada, Ova Oktavina, Prihartini Widiyanti

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Heart failure is a serious major health problem with high number of mortality per year. Bypass is one of the solutions that has often been taken. Natural vascular graft (xenograft) as the substitute in bypass is inconvenient due to ethic problems and the risk of infection transmission caused by the usage of another species transgenic vascular. Nowadays, synthetic materials have been fabricated from polymers. The aim of this research is to make a synthetic vascular graft with great physical strength, high biocompatibility, and good affordability. The method of this research was mixing PLGA and collagen by magnetic stirrer. This composite were shaped by spinneret with water as coagulant. Then it was coated by chitosan with 3 variations of weight (1 gram, 2 grams, and 3 grams) to increase hemo and cytocompatibility, proliferation, and cell attachment in order for the vascular graft candidates to be more biocompatible. Mechanical strength for each variation was 5,306 MPa (chitosan 1 gram), 3,433 MPa (chitosan 2 grams) and 3,745 MPa (chitosan 3 grams). All the tensile values were higher than human vascular tensile strength. Toxicity test showed that the living cells in all variations were more than 60% in number, thus the vascular graft is not toxic.

Keywords: chitosan, collagen, PLGA, spinneret

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Authors: Gabriel Wosiak, Felipe Staciaki, Eryka Nobrega, Ernesto Pereira

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Hydrogen is an energy carrier with potential applications in various industries. Alkaline electrolysis is a commonly used method for hydrogen production; however, its energy cost remains relatively high compared to other methods. This is due in part to interfacial pH changes that occur during the electrolysis process. Interfacial pH changes refer to the changes in pH that occur at the interface between the cathode electrode and the electrolyte solution. These changes are caused by the electrochemical reactions at both electrodes, which consume or produces hydroxide ions (OH-) from the electrolyte solution. This results in an important change in the local pH at the electrode surface, which can have several impacts on the energy consumption and durability of electrolysers. One impact of interfacial pH changes is an increase in the overpotential required for hydrogen production. Overpotential is the difference between the theoretical potential required for a reaction to occur and the actual potential that is applied to the electrodes. In the case of water electrolysis, the overpotential is caused by a number of factors, including the mass transport of reactants and products to and from the electrodes, the kinetics of the electrochemical reactions, and the interfacial pH. An increase in the interfacial pH at the anode surface in alkaline conditions can lead to an increase in the overpotential for hydrogen production. This is because the lower local pH makes it more difficult for the hydroxide ions to be oxidized. As a result, there is an increase in the required energy to the process occur. In addition to increasing the overpotential, interfacial pH changes can also lead to the degradation of the electrodes. This is because the lower pH can make the electrode more susceptible to corrosion. As a result, the electrodes may need to be replaced more frequently, which can increase the overall cost of water electrolysis. The method presented in the paper addresses the issue of interfacial pH changes by using a cell design with a different cell design, introducing the electrode asymmetry. This design helps to mitigate the pH gradient at the anode/electrolyte interface, which reduces the overpotential and improves the energy efficiency of the electrolyser. The method was tested using a multivariate approach in both laboratory and industrial current density conditions and validated the results with numerical simulations. The results demonstrated a clear improvement (11.6%) in energy efficiency, providing an important contribution to the field of sustainable energy production. The findings of the paper have important implications for the development of cost-effective and sustainable hydrogen production methods. By mitigating interfacial pH changes, it is possible to improve the energy efficiency of alkaline electrolysis and make it a more competitive option for hydrogen production.

Keywords: electrolyser, interfacial pH, numerical simulation, optimization, asymmetric cell

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Authors: Maria Krambia-Kapardis, Andreas Kapardis

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The relevant literature has been inundated with arguments for ethics, moral values, honesty, resilience, trust in leadership as well as responsible leadership. In many countries around the globe, and as shown by some recent reports, many political leaders are not role models and do not show best practices by being ethical, responsible, compassionate, and resilient. Journalists, whistleblowers, WikiLeaks, Al Jazeera, and the International Consortium of Investigative Journalists (ICIJ) have been brought out from the shadow of political leaders who lack the virtues/attributes outlined above by the UN Global Compact. A number of political leaders who lack ethical and responsible leadership skills will continue to find loopholes to enrich themselves and their close friends and relatives. Some researchers use the Millon Inventory of Diagnostic; however, this test, while it provides helpful and useful insights into the personality of a person who leads or inspire his/her people but does not show if that person is ethical, motivating, and empowers his people with trust and honesty. Thus, it is recommended that political leaders ought to undergo training that encompasses Aristotelian Ethics by embedding the appropriate values and behaviours in their strategies, policies, and decisions, enhancing the change factors that will help in the implementation of a more sustainable development model. Finally, there is a need to develop a pedagogy and a curriculum which enables the development of responsible political leaders.

Keywords: political leaders, corruption, anti-corruption, political corruption

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Authors: Khadidja Rahmani, Nahla Bouaziz

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Algeria is known for its rich heritage. It owns an immense historical heritage with a universal reputation. Unfortunately, this wealth is withered because of abundance. This research focuses on the Ksourian model, which constitutes a large portion of this wealth. In fact, the Ksourian model is not just a witness to a great part of history or a vernacular culture, but also it includes a panoply of assets in terms of energetic efficiency. In this context, the purpose of our work is to evaluate the performance of the old techniques which are derived from the Ksourian model , and that using the simulation tools. The proposed method is decomposed in two steps; the first consists of isolate and reintroduce each device into a basic model, then run a simulation series on acquired models. And this in order to test the contribution of each of these dialectal processes. In another scale of development, the second step consists of aggregating all these processes in an aboriginal model, then we restart the simulation, to see what it will give this mosaic on the environmental and energetic plan .The model chosen for this study is one of the ksar units of Knadsa city of Bechar (Algeria). This study does not only show the ingenuity of our ancestors in their know-how, and their adapting power to the aridity of the climate, but also proves that their conceptions subscribe in the current concerns of energy efficiency, and respond to the requirements of sustainable development.

Keywords: dialectal processes, energy efficiency, evaluation, Ksourian model, simulation tools

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Authors: Steve Apell

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Transit-oriented development (TOD) is a popular intervention for local governments endeavoring to reduce auto-dependency and the adverse effects of sprawl. At the same time, American households such as the millennial generation, are shifting their residential preferences from the suburbs to the central city. These changes have intensified demand for TOD housing which generates high rents. This leads to displacement of low-income, transit-dependent households by more affluent middle class families. Critics argue that, the effectiveness of TOD might be compromised as newer affluent residents drive more and use transit less. However, there has not been a comprehensive study to test this hypothesis. Using census data ( 1990 – 2012) from six metropolitans areas, this research investigated if block groups within one-mile radius of TOD are gentrifying. Our findings reveal that the price of housing and number of college graduates, increased more in TODs compared to the metropolitan area. Similarly, the percentage of immigrants increased in TOD, while those of blacks and whites declined. Most importantly, TOD residents generally commuted less by car, while transit use increased in some metropolitan areas. TOD in the south of the United States registered higher cost of housing and less transit use. These findings have significant implications for the future of equitable and sustainable transportation policy.

Keywords: commuting, equity, gentrification, mode choice, transit oriented development

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Authors: Min-Kook Park, Deuck Hang Lee, Hyun Mo Yang, Jae Hyun Kim, Kang Su Kim

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Prestressed hollow-core slabs (HCS) are structurally optimized precast units with light-weight hollowed-sections and very economical due to the mass production by a unique production method. They have been thus widely used in the precast concrete constructions in many countries all around the world. It is, however, difficult to provide shear reinforcement in HCS units produced by the extrusion method, and thus all the shear forces should be resisted solely by concrete webs in the HCS units. This means that, for the HCS units, it is very important to estimate the contribution of web concrete to the shear resistance accurately. In design codes, however, the shear strengths for HCS units are estimated by the same equations that are used for typical prestressed concrete members, which were determined from the calibrations to experimental results of conventional prestressed concrete members other than HCS units. In this study, therefore, shear test results of HCS members with a wide range of influential variables were collected, and the shear strength equations in design codes were thoroughly examined by comparing to the experimental results in the shear database of HCS members. Acknowledgement: This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning(NRF-2016R1A2B2010277).

Keywords: hollow-core, web-shear, precast concrete, prestress, capacity

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Authors: Aikaterini Kentroti, Theodore H. Kaskalis

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Today, web servers are expected to serve thousands of client requests concurrently within stringent response time limits. In this paper, we evaluate experimentally and compare the performance as well as the resource utilization of popular web servers, which differ in their approach to handle concurrency. More specifically, Central Processing Unit (CPU)- and I/O intensive tests were conducted against the thread-based Apache and Go as well as the event-based Nginx and Node.js under increasing concurrent load. The tests involved concurrent users requesting a term of the Fibonacci sequence (the 10th, 20th, 30th) and the content of a table from the database. The results show that Go achieved the best performance in all benchmark tests. For example, Go reached two times higher throughput than Node.js and five times higher than Apache and Nginx in the 20th Fibonacci term test. In addition, Go had the smallest memory footprint and demonstrated the most efficient resource utilization, in terms of CPU usage. Instead, Node.js had by far the largest memory footprint, consuming up to 90% more memory than Nginx and Apache. Regarding the performance of Apache and Nginx, our findings indicate that Hypertext Preprocessor (PHP) becomes a bottleneck when the servers are requested to respond by performing CPU-intensive tasks under increasing concurrent load.

Keywords: apache, Go, Nginx, node.js, web server benchmarking

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Authors: Marwan Keshlaf, Hassan Fellah

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This study was designed to test whether hive bottom boards modified with polyvinyl chloride pipe or screen-mesh reduces number of Varroa mites in naturally infested honeybee colonies comparing to chemical control. Fifty six colonies distributed equally between two location each received one of four experimental treatment 1) conventional solid board “control”, 2) Apistan in conventional solid board, 3) Mesh bottom board and 4) tube bottom board. Varroa infestation level on both adult bees and on capped brood was estimated. Stored pollen, capped brood area and honey production were also measured. Results of varroa infestation were inconsistent between apiaries. In apiary 1, colonies with Apistan had fewer Varroa destructor than other treatments, but this benefit was not apparent in Apiary 2. There were no effects of modified bottom boards on bee flight activity, brood production, honey yield and stored pollen. We conclude that the efficacy of modified bottom boards in reducing varroa mites population in bee colonies remains uncertain due to observed differences of hygienic behavior.

Keywords: Apis mellifera, modified bottom boards, Varroa destructor, Honeybee colonies

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Authors: Julio Albuja, David Zaldumbide

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Data analysis is an important step before taking a decision about money. The aim of this work is to analyze the factors that influence the final price of the houses through data mining algorithms. To our best knowledge, previous work was researched just to compare results. Furthermore, before using the data of the data set, the Z-Transformation were used to standardize the data in the same range. Hence, the data was classified into two groups to visualize them in a readability format. A decision tree was built, and graphical data is displayed where clearly is easy to see the results and the factors' influence in these graphics. The definitions of these methods are described, as well as the descriptions of the results. Finally, conclusions and recommendations are presented related to the released results that our research showed making it easier to apply these algorithms using a customized data set.

Keywords: algorithms, data, decision tree, transformation

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Authors: Charles Lee

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The Principal Orthogonal Decomposition (POD) technique has been used as a model reduction tool for many applications in engineering and science. In principle, one begins with an ensemble of data, called snapshots, collected from an experiment or laboratory results. The beauty of the POD technique is that when applied, the entire data set can be represented by the smallest number of orthogonal basis elements. It is the such capability that allows us to reduce the complexity and dimensions of many physical applications. Mathematical formulations and numerical schemes for the POD method will be discussed along with applications in NASA’s Deep Space Large Antenna Arrays, Satellite Image Reconstruction, Cancer Detection with DNA Microarray Data, Maximizing Stock Return, and Medical Imaging.

Keywords: reduced-order methods, principal component analysis, cancer detection, image reconstruction, stock portfolios

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Authors: Leja Salciute

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Mental health difficulties are one of the reasons for abnormal feeding behaviour. This is especially evident in a crisis situation. Abnormal feeding behaviour occurs when individuals use food as a method to provide relief for these negative emotions. The study aimed to discover an association between emotional regulation, mental health difficulties and disruption in feeding behaviours in the UK in times of crisis. A mixed-methods design was used. Abnormal feeding behaviour was measured using the Binge Eating Disorder Screener-7, SCOFF scale, Crisis impact scale, Difficulties in Emotion Regulation Scale and demographics. The sample comprised 342 participants with a history of excessive overeating. The participants (male= 198, female= 141 and other= 3) came from the general population and they were aged 16 and over. Participants ranged in age from 16 to 89. Findings from the survey concluded that difficulties with emotion regulation were found to be associated with abnormal feeding behaviours. Mental health difficulties correlated significantly with changes in individuals’ lives, such as work or routines. Individuals differed in their abnormal feeding behaviour in terms of their age, that is, younger individuals showed less struggle with their eating patterns while older individuals faced greater struggles with their abnormal feeding behaviour. Emotion regulation significantly influenced abnormal feeding behaviour. Results from qualitative data suggest four common themes that were identified: demonstration of gratitude, negative emotions, disruptions to social life, and financial loss. For example, participants developed and gained an awareness of being grateful for the simple things in life even when participants experienced hardships. The results also suggested that emotional eating acted like a sedative that allowed the participant to run away from their painful reality. Crisis situation negatively affected relationships among participants and induced negativity related to social interaction. Finally, the respondents highlighted that the presence of uncertainty made it hard to plan ahead and look forward to the future. Although respondents experienced negative emotions and financial losses, some of them still managed to allocate time for themselves and enjoy their time off during crisis. However, majority of respondents referred to their inability to control their external circumstances and turned to and relied upon food overconsumption instead. This had a negative effect on their mental health and presented disruptions in feeding behaviour. It was recommended for individuals in times of crisis to seek psychological support in the form of Cognitive Behavioural Therapy (CBT).

Keywords: binge eating, maladaptive eating behaviours, mental health, negative emotions in crisis

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Authors: Monica Enculescu, A. Evanghelidis, I. Enculescu

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Among the numerous methods for obtaining polymer nanofibers, the electrospinning technique distinguishes itself due to the more growing interest induced by its proved utility leading to developing and improving of the method and the appearance of novel materials. In particular, production of polymeric nanofibers in which different dopants are introduced was intensively studied in the last years because of the increased interest for the obtaining of functional electrospun nanofibers. Electrospinning is a facile method of obtaining polymer nanofibers with diameters from tens of nanometers to micrometrical sizes that are cheap, flexible, scalable, functional and biocompatible. Besides the multiple applications in medicine, polymeric nanofibers obtained by electrospinning permit manipulation of light at nanometric dimensions when doped with organic dyes or different nanoparticles. It is a simple technique that uses an electrical field to draw fine polymer nanofibers from solutions and does not require complicated devices or high temperatures. Different morphologies of the electrospun nanofibers can be obtained for the same polymeric host when different parameters of the electrospinning process are used. Consequently, we can obtain tuneable optical properties of the electrospun nanofibers (e.g. changing the wavelength of the emission peak) by varying the parameters of the fabrication method. We focus on obtaining doped polymer nanofibers with enhanced optical properties using the electrospinning technique. The aim of the paper is to produce dye-doped polymer nanofibers’ mats incorporating uniformly dispersed dyes. Transmission and fluorescence of the fibers will be evaluated by spectroscopy methods. The morphological properties of the electrospun dye-doped polymer fibers will be evaluated using scanning electron microscopy (SEM). We will tailor the luminescent properties of the material by doping the polymer (polyvinylpyrrolidone or polymethylmetacrilate) with different dyes (coumarins, rhodamines and sulforhodamines). The tailoring will be made taking into consideration the possibility of changing the luminescent properties of electrospun polymeric nanofibers that are doped with different dyes by using different parameters for the electrospinning technique (electric voltage, distance between electrodes, flow rate of the solution, etc.). Furthermore, we can evaluated the influence of the concentration of the dyes on the emissive properties of dye-doped polymer nanofibers using different concentrations. The advantages offered by the electrospinning technique when producing polymeric fibers are given by the simplicity of the method, the tunability of the morphology allowed by the possibility of controlling all the process parameters (temperature, viscosity of polymeric solution, applied voltage, distance between electrodes, etc.), and by the absence of necessity of using harsh and supplementary chemicals such as the ones used in the traditional nanofabrication techniques. Acknowledgments: The authors acknowledge the financial support received through IFA CEA Project No. C5-08/2016.

Keywords: electrospinning, luminescence, polymer nanofibers, scanning electron microscopy

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Authors: Marjila Burhanzoi, Kenta Onohara, Tomoaki Ikegami

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Faults in photovoltaic (PV) modules should be detected to the greatest extent as early as possible. For that conventional fault detection methods such as electrical characterization, visual inspection, infrared (IR) imaging, ultraviolet fluorescence and electroluminescence (EL) imaging are used, but they either fail to detect the location or category of fault, or they require expensive equipment and are not convenient for onsite application. Hence, these methods are not convenient to use for monitoring small-scale PV systems. Therefore, low cost and efficient inspection techniques with the ability of onsite application are indispensable for PV modules. In this study in order to establish efficient inspection technique, correlation between faults and magnetic flux density on the surface is of crystalline PV modules are investigated. Magnetic flux on the surface of normal and faulted PV modules is measured under the short circuit and illuminated conditions using two different sensor devices. One device is made of small integrated sensors namely 9-axis motion tracking sensor with a 3-axis electronic compass embedded, an IR temperature sensor, an optical laser position sensor and a microcontroller. This device measures the X, Y and Z components of the magnetic flux density (Bx, By and Bz) few mm above the surface of a PV module and outputs the data as line graphs in LabVIEW program. The second device is made of a laser optical sensor and two magnetic line sensor modules consisting 16 pieces of magnetic sensors. This device scans the magnetic field on the surface of PV module and outputs the data as a 3D surface plot of the magnetic flux intensity in a LabVIEW program. A PC equipped with LabVIEW software is used for data acquisition and analysis for both devices. To show the effectiveness of this method, measured results are compared to those of a normal reference module and their EL images. Through the experiments it was confirmed that the magnetic field in the faulted areas have different profiles which can be clearly identified in the measured plots. Measurement results showed a perfect correlation with the EL images and using position sensors it identified the exact location of faults. This method was applied on different modules and various faults were detected using it. The proposed method owns the ability of on-site measurement and real-time diagnosis. Since simple sensors are used to make the device, it is low cost and convenient to be sued by small-scale or residential PV system owners.

Keywords: fault diagnosis, fault location, integrated sensors, PV modules

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Authors: Minjung Kim, Hyunkoo Kang, Jinkoo Kim

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In this study, a seismic retrofit scheme for a reinforced concrete shear wall structure using steel slit dampers was presented. The stiffness and the strength of the slit damper used in the retrofit were verified by cyclic loading test. A genetic algorithm was applied to find out the optimum location of the slit dampers. The effects of the slit dampers on the seismic retrofit of the model were compared with those of jacketing shear walls. The seismic performance of the model structure with optimally positioned slit dampers was evaluated by nonlinear static and dynamic analyses. Based on the analysis results, the simple procedure for determining required damping ratio using capacity spectrum method along with the damper distribution pattern proportional to the inter-story drifts was validated. The analysis results showed that the seismic retrofit of the model structure using the slit dampers was more economical than the jacketing of the shear walls and that the capacity spectrum method combined with the simple damper distribution pattern led to satisfactory damper distribution pattern compatible with the solution obtained from the genetic algorithm.

Keywords: seismic retrofit, slit dampers, genetic algorithm, jacketing, capacity spectrum method

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Authors: Alireza Jafarzadeh, Bahram Amu-Oqhli Tabrizi, Hadi Khayat Nouri, Arash Khaki

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30 head of adult Vistar rats were chosen to evaluate the chronic narcotic effects of crack on some biochemical parameters. The rats weighted approximately 200 to 250 g. They were divided into 5 groups of 6 and were housed in identical condition in terms of food and ambience. Rats were maintained at 12 hours light and 12 hours darkness. Rats were injected 7.8 mg/kg BW crack intraperitoneally. The groups one to four received daily medication for one to four weeks respectively. The control groups were injected identical dose of saline. The blood was taken from control and test groups then serum was separated from. Serum biochemical parameters of amylase, lipase, triglycerides, cholesterol, HDL, LDL, VLDL, protein and albumin were measured by diagnostic kits. Serum protein and albumin levels did not show statistically significant changes. Serum lipase and amylase showed significant changes both of which were increased. The serum levels of cholesterol, LDL and HDL demonstrated no significant changes. Triglycerides values showed a significant increase in serum. Serum VLDL in groups 3 and 4 exhibited significant changes compare to other groups.

Keywords: albumin, amylase, cholesterol, crack, HDL, LDL, lipase, protein, rat, triglycerides, VLDL

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Authors: Syue-Wen Lin

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Objective:This article reviews the care experience of a 40-year-old male patient who underwent a thoracoscopic right lower lobectomy following a COVID-19 infection. His complex medical history included multiple metastases (lungs, liver, spleen, and left kidney) and lung damage from COVID-19, which complicated the weaning process from mechanical ventilation. The care involved managing cancer treatment, postoperative pain, wound care, and palliative care. Methods:Nursing care was provided from August 16 to August 17, 2024. Challenges included difficulty with sputum clearance, which exacerbated the patient's anxiety and fear of reintubation. Pain management strategies combined analgesic drugs, non-drug methods, essential oil massages with family members, and playing the patient’s favorite music to reduce pain and anxiety. Progressive rehabilitation began with stabilizing vital signs, followed by assistance with sitting on the edge of the bed and walking within the ward. Strict sterile procedures and advanced wound care technology were used for daily dressing changes, with meticulous documentation of wound conditions and appropriate dressing selection. Holistic cancer care and palliative measures were integrated to address the patient’s physical and psychological needs. Results:The interdisciplinary care team developed a comprehensive plan addressing both physical and psychological aspects. Respiratory therapy, lung expansion exercises, and a high-frequency chest wall oscillation vest facilitated sputum expulsion and assisted in weaning from mechanical ventilation. The integration of cancer care, pain management, wound care, and palliative care led to improved quality of life and recovery. The collaborative approach between nursing staff and family ensured that the patient received compassionate and effective care. Conclusion: The complex interplay of emergency surgery, COVID-19, and advanced cancer required a multifaceted care strategy. The care team’s approach, combining critical care with tailored cancer and palliative care, effectively improved the patient’s quality of life and facilitated recovery. The comprehensive care plan, developed with family collaboration, provided both high-quality medical care and compassionate support for the terminally ill patient.

Keywords: multiple metastases, testicular cancer, palliative care, nursing experience

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Authors: Chechen Liao, Chin Yi Yang

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Although several factors that affect learning to program have been identified over the years, there continues to be no indication of any consensus in understanding why some students learn to program easily and quickly while others have difficulty. Seldom have researchers considered the problem of how to help the students enhance the programming learning outcome. The research had been conducted at a high school in Taiwan. Students participating in the study consist of 330 tenth grade students enrolled in the Basic Computer Concepts course with the same instructor. Two types of training methods-instruction-oriented and exploration-oriented were conducted. The result of this research shows that the instruction-oriented training method has better learning performance than exploration-oriented training method.

Keywords: learning performance, programming learning, TDD, training method

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Authors: Maanav M. Patel, Aarsh S. Mistry, Yash A. Dhaduk

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Nowadays, only a small percentage of waste tyres are being land-filled. The Recycled Tyres Rubber is being used in new tyres, in tyre-derived fuel, in civil engineering applications and products, in molded rubber products, in agricultural uses, recreational and sports applications and in rubber modified asphalt applications. The benefits of using rubber modified asphalts are being more widely experienced and recognized, and the incorporation of tyres into asphalt is likely to increase. The technology with much different evidence of success demonstrated by roads built in the last 40 years is the rubberised asphalt mixture obtained through the so-called ‘‘wet process’’ which involves the utilisation of the Recycled Tyre Rubber Modified Bitumen (RTR-MBs). Since 1960s, asphalt mixtures produced with RTRMBs have been used in different parts of the world as solutions for different quality problems and, despite some downsides, in the majority of the cases they have demonstrated to enhance performance of road’s pavement. The present study aims in investigating the experimental performance of the bitumen modified with 15% by weight of crumb rubber varying its sizes. Four different categories of size of crumb rubber will be used, which are coarse (1 mm - 600 μm); medium size (600 μm - 300 μm); fine (300 μm150 μm); and superfine (150 μm - 75 μm). Common laboratory tests will be performed on the modified bitumen using various sizes of crumb rubber and thus analyzed. Marshall Stability method is adopted for mix design.

Keywords: Bitumen, CRMB, Marshall Stability Test, Pavement

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Authors: Andrey Davydov, Konstantin Sveshnikov, Yulia Voronina

Abstract:

There is now a lot of interest to the non-perturbative QED-effects, caused by diving of discrete levels into the negative continuum in the supercritical static or adiabatically slowly varying Coulomb fields, that are created by the localized extended sources with Z > Z_cr. Such effects have attracted a considerable amount of theoretical and experimental activity, since in 3+1 QED for Z > Z_cr,1 ≈ 170 a non-perturbative reconstruction of the vacuum state is predicted, which should be accompanied by a number of nontrivial effects, including the vacuum positron emission. Similar in essence effects should be expected also in both 2+1 D (planar graphene-based hetero-structures) and 1+1 D (one-dimensional ‘hydrogen ion’). This report is devoted to the study of such essentially non-perturbative vacuum effects for the supercritical Dirac-Coulomb systems in 1+1D and 2+1D, with the main attention drawn to the vacuum polarization energy. Although the most of works considers the vacuum charge density as the main polarization observable, vacuum energy turns out to be not less informative and in many respects complementary to the vacuum density. Moreover, the main non-perturbative effects, which appear in vacuum polarization for supercritical fields due to the levels diving into the lower continuum, show up in the behavior of vacuum energy even more clear, demonstrating explicitly their possible role in the supercritical region. Both in 1+1D and 2+1D, we explore firstly the renormalized vacuum density in the supercritical region using the Wichmann-Kroll method. Thereafter, taking into account the results for the vacuum density, we formulate the renormalization procedure for the vacuum energy. To evaluate the latter explicitly, an original technique, based on a special combination of analytical methods, computer algebra tools and numerical calculations, is applied. It is shown that, for a wide range of the external source parameters (the charge Z and size R), in the supercritical region the renormalized vacuum energy could significantly deviate from the perturbative quadratic growth up to pronouncedly decreasing behavior with jumps by (-2 x mc^2), which occur each time, when the next discrete level dives into the negative continuum. In the considered range of variation of Z and R, the vacuum energy behaves like ~ -Z^2/R in 1+1D and ~ -Z^3/R in 2+1D, exceeding deeply negative values. Such behavior confirms the assumption of the neutral vacuum transmutation into the charged one, and thereby of the spontaneous positron emission, accompanying the emergence of the next vacuum shell due to the total charge conservation. To the end, we also note that the methods, developed for the vacuum energy evaluation in 2+1 D, with minimal complements could be carried over to the three-dimensional case, where the vacuum energy is expected to be ~ -Z^4/R and so could be competitive with the classical electrostatic energy of the Coulomb source.

Keywords: non-perturbative QED-effects, one- and two-dimensional Dirac-Coulomb systems, supercritical fields, vacuum polarization

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Authors: A. Bentley, A. Prost, N. Daruwalla, D. Osrin

Abstract:

Background: This study aims to investigate the relationship between experiences of violence against women in the family, and levels of self-esteem in women residing in informal settlement (slum) areas of Mumbai, India. The authors hypothesise that violence against women in Indian households extends beyond that of intimate partner violence (IPV), to include other members of the family and that experiences of violence are associated with lower levels of self-esteem. Methods: Experiences of violence were assessed through a cross-sectional survey of 598 women, including questions about specific acts of emotional, economic, physical and sexual violence across different time points, and the main perpetrator of each. Self-esteem was assessed using the Rosenberg self-esteem questionnaire. A global score for self-esteem was calculated and the relationship between violence in the past year and Rosenberg self-esteem score was assessed using multivariable linear regression models, adjusted for years of education completed, and clustering using robust standard errors. Results: 482 (81%) women consented to interview. On average, they were 28.5 years old, had completed 6 years of education and had been married 9.5 years. 88% were Muslim and 46% lived in joint families. 44% of women had experienced at least one act of violence in their lifetime (33% emotional, 22% economic, 24% physical, 12% sexual). Of the women who experienced violence after marriage, 70% cited a perpetrator other than the husband for at least one of the acts. 5% had low self-esteem (Rosenberg score < 15). For women who experienced emotional violence in the past year, the Rosenberg score was 2.6 points lower (p < 0.001). It was 1.2 points lower (p = 0.03) for women who experienced economic violence. For physical or sexual violence in the past year, no statistically significant relationship with Rosenberg score was seen. However, for a one-unit increase in the number of different acts of each type of violence experienced in the past year, a decrease in Rosenberg score was seen (-0.62 for emotional, -0.76 for economic, -0.53 for physical and -0.47 for sexual; p < 0.05 for all). Discussion: The high prevalence of violence experiences across the lifetime was likely due to the detailed assessment of violence and the inclusion of perpetrators within the family other than the husband. Experiences of emotional or economic violence in the past year were associated with lower Rosenberg scores and therefore lower self-esteem, but no relationship was seen between experiences of physical or sexual violence and Rosenberg score overall. For all types of violence in the past year, a greater number of different acts were associated with a decrease in Rosenberg score. Emotional violence showed the strongest relationship with self-esteem, but for all types of violence the more complex the pattern of perpetration with different methods used, the lower the levels of self-esteem. Due to the cross-sectional nature of the study causal directionality cannot be attributed. Further work to investigate the relationship between severity of violence and self-esteem and whether self-esteem mediates relationships between violence and poorer mental health would be beneficial.

Keywords: family violence, India, informal settlements, Rosenberg self-esteem scale, self-esteem, violence against women

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Authors: Judit Manuel-i-Martin, Mechthild Donner, Ivana Radic, Yamna Erraach, Fatima Elhadad, Taoufik Yatribi, Feliu Lopez-i-Gelats

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This paper investigates how small olive farmers and olive oil producers implement circular economy practices to manage olive related waste and how such strategies are perceived by the farmers themselves. While there is a lot of data and research about possible uses of olive oil by-products, the perceptions and related practices of olive oil farmers is a much less investigated domain. A total of 60 semi-structured interviews were conducted in one of the most relevant olive oil producing regions in the Iberian Peninsula -the region of Terres de Ponent (Catalonia – Spain) - to examine the different by-product valorization strategies the olive oil farms develop. We test the hypothesis that the strategies conducted depend on the nature and amount of resources available by the farm. The results obtained point that access to milling infrastructure is a determining factor. We also found that olive tree pruning biomass and olive pomace are the most common by-products valorized by farmers, the first one on-farm and the latter in mills. Results indicate that high value uses for olive oil by-products are rarely implemented by farmers. We conclude that olive farmers tend to perceive by-product valorization strategies as waste management practices rather than as additional sources of value for their farm.

Keywords: circular economy, discourses, Mediterranean region, olive oil by-products, farmers’ strategies, olive pomace

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Authors: Prasannakumar Palaniappan, Dong Ho Shin, Chul Gyu Song

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The photoacoustic images are obtained from a custom developed linear array photoacoustic tomography system. The biological specimens are imitated by conducting phantom tests in order to retrieve a fully functional photoacoustic image. The acquired image undergoes the active region based contour filtering to remove the noise and accurately segment the object area for further processing. The universal back projection method is used as the image reconstruction algorithm. The active contour filtering is analyzed by evaluating the signal to noise ratio and comparing it with the other filtering methods.

Keywords: contour filtering, linear array, photoacoustic tomography, universal back projection

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Authors: Mehrnaz Mostafavi, Jalaledin Ghanavi

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This research investigates the production of nanoring structures through a chemical reduction approach, exploring gradual reduction processes assisted by reductant agents, leading to the formation of these specialized nanorings. The study focuses on the controlled reduction of metal atoms within these agents, crucial for shaping these nanoring structures over time. The paper commences by highlighting the wide-ranging applications of metal nanostructures across fields like Nanomedicine, Nanobiotechnology, and advanced spectroscopy methods such as Surface Enhanced Raman Spectroscopy (SERS) and Surface Enhanced Infrared Absorption Spectroscopy (SEIRA). Particularly, gold nanoparticles, especially in the nanoring configuration, have gained significant attention due to their distinctive properties, offering accessible spaces suitable for sensing and spectroscopic applications. The methodology involves utilizing human serum albumin as a reducing agent to create gold nanoparticles through a chemical reduction process. This process involves the transfer of electrons from albumin's carboxylic groups, converting them into carbonyl, while AuCl4− acquires electrons to form gold nanoparticles. Various characterization techniques like Ultraviolet–visible spectroscopy (UV-Vis), Atomic-force microscopy (AFM), and Transmission electron microscopy (TEM) were employed to examine and validate the creation and properties of the gold nanoparticles and nanorings. The findings suggest that precise and gradual reduction processes, in conjunction with optimal pH conditions, play a pivotal role in generating nanoring structures. Experiments manipulating optical properties revealed distinct responses in the visible and infrared spectrums, demonstrating the tunability of these nanorings. Detailed examinations of the morphology confirmed the formation of gold nanorings, elucidating their size, distribution, and structural characteristics. These nanorings, characterized by an empty volume enclosed by uniform walls, exhibit promising potential in the realms of Nanomedicine and Nanobiotechnology. In summary, this study presents a chemical synthesis approach using organic reducing agents to produce gold nanorings. The results underscore the significance of controlled and gradual reduction processes in crafting nanoring structures with unique optical traits, offering considerable value across diverse nanotechnological applications.

Keywords: nanoring structures, chemical reduction approach, gold nanoparticles, spectroscopy methods, nano medicine applications

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Authors: Pepe Marais, Krishna Govender

Abstract:

This study aimed to investigate the impact of “purpose” as a principal leadership skill on the performance of two township schools using a quantitative research design and collecting data from the school principals, teachers and matric learners, using the 28-scale Servant Leadership Test as well as Gallup’s Q12 Employee Engagement survey. The questionnaires addressed the key objectives, namely, the extent to which the principals of the participating schools exhibited servant leadership and their understanding of “purpose” as one word in leadership and how teachers and learners perceived the impact of a “one-word” purpose-driven leader on the performance of the selected schools. Although no relationship could be demonstrated between ‘’purpose’’ and the performance of the two township schools, it became evident that a significant increase in Servant Leadership leads to a significant increase in engagement and performance, as measured by the matric pass rate. It is recommended that workshops be facilitated with principals and teachers in order to entrench ‘’purpose’’ deeper throughout the schools. In addition, Servant Leadership training has to be conduced to increase the leadership ability of the school principals. Future research in the area of ‘’purpose as one word’’, as well as Servant Leadership as a principal skillset within South Africa’s public school leadership, is recommended.

Keywords: school leadership, servant leadership, one-word purpose, engagement, leadership

Procedia PDF Downloads 118