Search results for: strength class

Authors: Lyudmila L. Gracheva

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Thermal shield is a multi-layer structure that consists of layers made of different materials. The use of composite materials (CM) reinforced with carbon fibers in rocket technologies (shells, bearings, wings, fairings, inter-step compartments, etc.) is due to a possibility of reducing the weight while increasing a structural strength. Structures made of a unidirectional carbon fiber reinforced plastic based on an epoxy resin are used as load-bearing skins for aircraft fairings. The results of an experimental study of the physical and mechanical properties of epoxy carbon fiber reinforced plastics depending on temperature for different storage times of products are presented. With an increasing temperature, the physical and mechanical properties of CM are determined by the thermal and deformation properties of the components and the geometry of their distribution. Samples for the study were cut from natural skins of the head fairings.

Keywords: composite material, thermal deformation, carbon fiber, heat shield, epoxy resin, thermal expansion

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Authors: Mylena McCoggle, Shyra Wilson, Andrea Rivera, Rocio Alba-Flores

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This work introduces the use of EMGs (electromyography) from muscle sensors to develop an Artificial Neural Network (ANN) for pattern recognition to control a small unmanned aerial vehicle. The objective of this endeavor exhibits interfacing drone applications beyond manual control directly. MyoWare Muscle sensor contains three EMG electrodes (dual and single type) used to collect signals from the posterior (extensor) and anterior (flexor) forearm and the bicep. Collection of raw voltages from each sensor were connected to an Arduino Uno and a data processing algorithm was developed with the purpose of interpreting the voltage signals given when performing flexing, resting, and motion of the arm. Each sensor collected eight values over a two-second period for the duration of one minute, per assessment. During each two-second interval, the movements were alternating between a resting reference class and an active motion class, resulting in controlling the motion of the drone with left and right movements. This paper further investigated adding up to three sensors to differentiate between hand gestures to control the principal motions of the drone (left, right, up, and land). The hand gestures chosen to execute these movements were: a resting position, a thumbs up, a hand swipe right motion, and a flexing position. The MATLAB software was utilized to collect, process, and analyze the signals from the sensors. The protocol (machine learning tool) was used to classify the hand gestures. To generate the input vector to the ANN, the mean, root means squared, and standard deviation was processed for every two-second interval of the hand gestures. The neuromuscular information was then trained using an artificial neural network with one hidden layer of 10 neurons to categorize the four targets, one for each hand gesture. Once the machine learning training was completed, the resulting network interpreted the processed inputs and returned the probabilities of each class. Based on the resultant probability of the application process, once an output was greater or equal to 80% of matching a specific target class, the drone would perform the motion expected. Afterward, each movement was sent from the computer to the drone through a Wi-Fi network connection. These procedures have been successfully tested and integrated into trial flights, where the drone has responded successfully in real-time to predefined command inputs with the machine learning algorithm through the MyoWare sensor interface. The full paper will describe in detail the database of the hand gestures, the details of the ANN architecture, and confusion matrices results.

Keywords: artificial neural network, biosensors, electromyography, machine learning, MyoWare muscle sensors, Arduino

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Authors: A. Goodarzian, A. Ghasemipanah, R. Ziaie Moayed, H. Niroumand

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The problem of soil stabilization has been one of the important issues in geotechnical engineering. Nowadays, nanomaterials have revolutionized many industries. In this research, improvement of the Kerman fine-grained soil by nanozeolite and nanobentonite additives separately has been investigated using Atterberg Limits and unconfined compression test. In unconfined compression test, the samples were prepared with 3, 5 and 7% nano additives, with 1, 7 and 28 days curing time with strain control method. Finally, the effect of different percentages of nanozeolite and nanobentonite on the geotechnical behavior and characteristics of Kerman fine-grained soil was investigated. The results showed that with increasing the amount of nanozeolite and also nanobentonite to fine-grained soil, the soil exhibits more compression strength. So that by adding 7% nanozeolite and nanobentonite with 1 day curing, the unconfined compression strength is 1.18 and 2.1 times higher than the unstabilized soil. In addition, the failure strain decreases in samples containing nanozeolite, whereas it increases in the presence of nanobentonite. Increasing the percentage of nanozeolite and nanobentonite also increased the elasticity modulus of soil.

Keywords: nanoparticles, soil improvement, clayey soil, unconfined compression stress

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Authors: Bencharif Meriem, Sersar Ibrahim, Djaafri Zineb

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Introduction and purpose of the study: Education plays a fundamental role in the lives of young people, but what about their physical well-being as they spend long hours sitting at school? School inactivity is a problem that deserves particular attention because it can have significant repercussions on the health and development of students. The aim of this study was to describe and evaluate the physical activity of students in different practices in class, at recess and in the canteen. Material and methods: A physical activity diary and an anthropometric measurement sheet (weight, height) were provided to 123 school-aged adolescents. The measurements were carried out according to international recommendations. The statistical tests were carried out with the R software. 3.2.4. The significance threshold retained was 0.05. Results and Statistical Analysis: One hundred and twenty-three students agreed to participate in the study. Their average age was 16.5±1.60 years. Overweight was present in 8.13% and obesity in 4.06%. For the practice of physical activity, during physical education and sports classes, all students played sports with an average of 1.94±1.00 hours/week, of which 74.00% sweated or were out of breath during these hours of physical activity. It was also noted that boys practiced sports more than girls (p<0.0001). Each day, on average, students spent 39.78±37.85 min walking or running during recess. On the other hand, they spent, on average 4.25±2.65 hours sitting per day in class, at recess, in the canteen, etc., without counting the time spent in front of a screen. The increasing use of screens has become a major concern for parents and educators. On average, students spent approximately 42.90±38.41 min per day using screens in class, at recess, in the canteen and at home. (computer, tablet, telephone, video games, etc.) and therefore to a prolonged sedentary lifestyle. On average, students sat for more than 1.5 hours without moving for at least 2 minutes in a row approximately 1.72±0.71 times per day. Conclusion: These students spent many hours sitting at school. This prolonged inactivity can have negative consequences on their health, including problems with posture and cardiovascular health. It is crucial that schools, educators and parents collaborate to promote more active learning environments where students can move more and thus contribute to their overall well-being. It's time to rethink how we approach education and student health to give them a healthier, more active future.

Keywords: physical acivity, sedentarity, adolescents, school

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Authors: WooYoung Jung, V. Sim

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This paper presents numerical analysis in terms of buckling resistance strength of polymer matrix composite (PMC) infill panels system under the influence of temperature on the foam core. Failure mode under in-plane compression is investigated by means of numerical analysis with ABAQUS platform. Parameters considered in this study are contact length and both the type of foam for core and the variation of its Young's Modulus under the thermal influence. Variation of temperature is considered in static cases and only applied to core. Indeed, it is shown that the effect of temperature on the panel system mechanical properties is significance. Moreover, the variations of temperature result in the decrements of the system strength. This is due to the polymeric nature of this material. Additionally, the contact length also displays the effect on performance of infill panel. Their significance factors are based on type of polymer for core. Hence, by comparing difference type of core material, the variation can be reducing.

Keywords: buckling, contact length, foam core, temperature dependent

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Authors: Asim Alsharif, Christophe Pinna, Hassan Ghadbeigi

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The development of next-generation advanced high strength steels (AHSS) used in the automotive industry requires a better understanding of local deformation and damage development at the scale of their microstructures. This work is focused on dual-phase DP1000 steels and involves micro-mechanical tensile testing inside a scanning electron microscope (SEM) combined with digital image correlation (DIC) to quantify the heterogeneity of deformation in both ferrite and martensite and its evolution up to fracture. Natural features of the microstructure are used for the correlation carried out using Davis LaVision software. Strain localization is observed in both phases with tensile strain values up to 130% and 110% recorded in ferrite and martensite respectively just before final fracture. Damage initiation sites have been observed during deformation in martensite but could not be correlated to local strain values. A finite element (FE) model of the microstructure has then been developed using Abaqus to map stress distributions over representative areas of the microstructure by forcing the model to deform as in the experiment using DIC-measured displacement maps as boundary conditions. A MATLAB code has been developed to automatically mesh the microstructure from SEM images and to map displacement vectors from DIC onto the FE mesh. Results show a correlation of damage initiation at the interface between ferrite and martensite with local principal stress values of about 1700MPa in the martensite phase. Damage in ferrite is now being investigated, and results are expected to bring new insight into damage development in DP steels.

Keywords: advanced high strength steels, digital image correlation, finite element modelling, micro-mechanical testing

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Authors: Siriniya Siribrahmanakul

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Introduction:SARsCOVID-19 is rapidly spreading, and some people may exhibit severe symptoms. Mortality rate of 2.0–3.0% with COVID-19 infection atworldwide. Human leukocyte antigen (HLA), located on chromosome 6, consist of HLA class I and class II. HLA are used by the immune system to attach self-antigens. Previous studies, HLA-DRB1*01:01,HLA-DRB1*12:01and HLA-DRB1*14:04 were, showed significant difference with severe COVID-19 in the Chinese population by p-value < 0.05. Objective: We investigated the prevalence of HLA-DRB1 alleles associated with severe COVID-19 in Thai population. Materials and Methods:200 DNA samples were isolated from EDTA blood using the MagNAprue Compact Nucleic Acid Isolation kits.HLA-DRB1alleles were genotyped using sequence-specific oligonucleotides (PCR-SSOs). Results:The frequency of HLA-DRB1 alleles in Thai population wereHLA-DRB1*12:02 (15.75%), HLA-DRB1*15:02 (14.50%), HLA-DRB1*09:01 (11.50%), HLA-DRB1*07:01 (9.50%), HLA-DRB1*03:01,HLA-DRB1*05:01 (5.75%), HLA-DRB1*14:01 (5.50%), HLA-DRB1*16:02 (4.50%), HLA-DRB1*04:05 (4.00%), HLA-DRB1*14:03 (3.25%), HLA-DRB1*10:01 (2.25%) and HLA-DRB1*13:02 (2.00%). Particularly, HLA-DRB1*12:02 allele was the highest allele frequency presented in the four regions groups of Thai population. Furthermore, the HLA-DRB1* alleles associated with severe COVID-19, which consists ofHLA-DRB1*14:04(2.00 %) and HLA-DRB1*12:01(0.50%) in Thai population, whereas HLA-DRB1*01:01 allele was not found in this population. HLA-DRB1*14:04 and HLA-DRB1*12:01alleles were similarly distributed in four regions populations in Thailand (p-value > 0.05). The alleles frequencies of HLA-DRB1*14:04 and HLA-DRB1*12:01, which associated with severe COVID-19, had no significant differences between Thai population, South China population, South Africa population, and South Koreapopulation (p-value > 0.05). Conclusions: Particularly, this study has focused on allele frequency of HLA-DRB1*14:04in a healthy Thai population to evaluating their impact on the severe COVID-19. Furthermore, our research needs to be done in larger numbers of Thai patients.

Keywords: HLA-DRB1, allele frequency, Thai population, COVID-19 marker

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Authors: Raed Abendeh, Mousa Bani Baker, Zaydoun Abu Salem, Hesham Ahmad

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The using of waste materials in the construction industry can reduce the dependence on the natural aggregates which are going at the end to deplete. The glass waste is generated in a huge amount which can make one of its disposal in concrete industry effective not only as a green solution but also as an advantage to enhance the performance of mechanical properties and durability of concrete. This article reports the performance of concrete specimens containing different percentages of milled glass waste as a partial replacement of cement (Powder), when they are subject to cycles of freezing and thawing. The tests were conducted on 75-mm cubes and 75 x 75 x 300-mm prisms. Compressive strength based on laboratory testing and non-destructive ultrasonic pulse velocity test were performed during the action of freezing-thawing cycles (F/T). The results revealed that the incorporation of glass waste in concrete mixtures is not only feasible but also showed generally better strength and durability performance than control concrete mixture. It may be said that the recycling of waste glass in concrete mixes is not only a disposal way, but also it can be an exploitation in concrete industry.

Keywords: durability, glass waste, freeze-thaw cycles, non-destructive test

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Authors: Baskar Kotte

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Many organizations are constantly striving to implement numerous techniques for long-term sustainability, for food related organizations it is imperative to conceptualize the critical concepts which constitute food safety sustainability. This presentation provides three critical pillars to develop a sustainable organization. Financial sustainability, regulatory sustainability and excellence standards sustainability are the three components which practiced and implemented effectively with process performance metrics defined objectives and targets lead to sustainable and safe food organizations. The participants take away a well-developed concept diagram with all elements impacting sustainability. Proven disciplined path which worked to achieve desired results is presented for effective implementation. Effective implementation of this proven disciplined path positions organizations to achieve world class status with bottomline improvement. Additionally, this presentation highlights critical terms, principles and implementation difficulties related to using the proven disciplined path. This presentation is beneficial for business leaders, food safety compliance managers, food safety practitioners, financial managers, Lean & Six sigma continual improvement managers, BRC/SQF/ IFS / FSSC 22000 practitioners and food manufacturing personnel.

Keywords: food safety, sustainability, regulatory, lean, six sigma, bottom-line improvement disciplined path

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Authors: Fathiah Mohamed Zuki, Robert George Edyvean

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Electrostatic interaction energy (∆EEDL) is a part of the Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, which, together with van der Waals (∆EVDW) and acid base (∆EAB) interaction energies, has been extensively used to investigate the initial adhesion of bacteria to surfaces. Electrostatic or electrical double layer interaction energy is considerably affected by surface potential, however it cannot be determined experimentally and is usually replaced by zeta (ζ) potential via electrophoretic mobility. This paper focuses on the effect of ionic concentration as a function of pH and the effect of mineral grain size on ζ potential. It was found that both ionic strength and mineral grain size play a major role in determining the value of ζ potential for the adhesion of P. putida to hematite and quartz surfaces. Higher ζ potential values lead to higher electrostatic interaction energies and eventually to higher total XDLVO interaction energy resulting in bacterial repulsion.

Keywords: XDLVO, electrostatic interaction energy, zeta potential, P. putida, mineral

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Authors: Najeeb Niazi, Salman Nisar, Aqueel Shah

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In this study a special heat treatment process named austempering on AISI 4340 steel is carried out. Heat treatment on steel is carried out to enhance mechanical properties. In this regard, it is considered essential to undertake a study to evaluate different changes occurred in AISI 4340 steel in terms of hardness, tensile strength and impact strength at different austempering temperatures and cooling times and achieving the best combination of these improved mechanical properties for better and optimum utilization of this grade of steel. By using software Design Expert DOE is formulated with Taguchi orthogonal arrays comprising of L18 (3*3) with 03 factors and 03 responses to be calculated. Results of experiments are analyzed via Taguchi method. Signal to noise ratio of responses are carried out to determine the significant factors among the 03 factors chosen for experimental runs. Overall analysis showed that impact factor along with hardness is improved to great extent by austempering process.

Keywords: austempering temperature, AISI 4340 steel, bainite, Taguchi

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Authors: Emmanuel Ogundimu, Esther Akinlabi, Mutiu Erinosho

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Welding is described as the process of joining metals so that bonding can be created as a result of inter-atomic penetration. This study investigated the influence of heat input on the efficiency of the welded joints of 304 stainless steel. Three welds joint were made from two similar 304 stainless steel plates of thickness 6 mm. The tensile results obtained showed that the maximum average tensile strength of 672 MPa is possessed by the sample A1 with low heat input. It was discovered that the tensile strength, % elongation and weld joint efficiency decreased with the increase in heat input into the weld. The average % elongation for the entire samples ranged from 28.4% to 36.5%. Sample A1 had the highest joint efficiency of 94.5%. However, the optimum welding current of 190 for TIG- MIG hybrid welding of type-304 austenite stainless steel can be recommended for advanced technological applications such as aircraft manufacturing, nuclear industry, automobile industry, and processing industry.

Keywords: microhardness, microstructure, tensile, MIG welding, process, tensile, shear stress TIG welding, TIG-MIG welding

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Authors: Nadarajah I. Ramesh

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Much of the research on stochastic point process models for rainfall has focused on Poisson cluster models constructed from either the Neyman-Scott or Bartlett-Lewis processes. The doubly stochastic Poisson process provides a rich class of point process models, especially for fine-scale rainfall modelling. This paper provides an account of recent development on this topic and presents the results based on some of the fine-scale rainfall models constructed from this class of stochastic point processes. Amongst the literature on stochastic models for rainfall, greater emphasis has been placed on modelling rainfall data recorded at hourly or daily aggregation levels. Stochastic models for sub-hourly rainfall are equally important, as there is a need to reproduce rainfall time series at fine temporal resolutions in some hydrological applications. For example, the study of climate change impacts on hydrology and water management initiatives requires the availability of data at fine temporal resolutions. One approach to generating such rainfall data relies on the combination of an hourly stochastic rainfall simulator, together with a disaggregator making use of downscaling techniques. Recent work on this topic adopted a different approach by developing specialist stochastic point process models for fine-scale rainfall aimed at generating synthetic precipitation time series directly from the proposed stochastic model. One strand of this approach focused on developing a class of doubly stochastic Poisson process (DSPP) models for fine-scale rainfall to analyse data collected in the form of rainfall bucket tip time series. In this context, the arrival pattern of rain gauge bucket tip times N(t) is viewed as a DSPP whose rate of occurrence varies according to an unobserved finite state irreducible Markov process X(t). Since the likelihood function of this process can be obtained, by conditioning on the underlying Markov process X(t), the models were fitted with maximum likelihood methods. The proposed models were applied directly to the raw data collected by tipping-bucket rain gauges, thus avoiding the need to convert tip-times to rainfall depths prior to fitting the models. One advantage of this approach was that the use of maximum likelihood methods enables a more straightforward estimation of parameter uncertainty and comparison of sub-models of interest. Another strand of this approach employed the DSPP model for the arrivals of rain cells and attached a pulse or a cluster of pulses to each rain cell. Different mechanisms for the pattern of the pulse process were used to construct variants of this model. We present the results of these models when they were fitted to hourly and sub-hourly rainfall data. The results of our analysis suggest that the proposed class of stochastic models is capable of reproducing the fine-scale structure of the rainfall process, and hence provides a useful tool in hydrological modelling.

Keywords: fine-scale rainfall, maximum likelihood, point process, stochastic model

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Authors: Purba Biswas, Priyanka Dey

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Worldwide rapid urbanisation has accelerated city expansion in both developed and developing nations. This unprecedented urbanisation trend due to the increasing population and economic growth has caused challenges for the decision-makers in city planning and urban management. Metropolitan cities, class-I towns, and major urban centres undergo a continuous process of evolution due to interaction between socio-cultural and economic attributes. This constant evolution leads to urban expansion in all directions. Understanding the patterns and dynamics of urban built-up growth is crucial for policymakers, urban planners, and researchers, as it aids in resource management, decision-making, and the development of sustainable strategies to address the complexities associated with rapid urbanisation. Identifying spatio-temporal patterns of urban growth has emerged as a crucial challenge in monitoring and assessing present and future trends in urban development. Analysing urban growth patterns and tracking changes in land use is an important aspect of urban studies. This study analyses spatio-temporal urban transformations and land-use and land cover changes using remote sensing and GIS techniques. Built-up growth analysis has been done for the city of Surat as a case example, using the GIS tools of NDBI and GIS models of the Built-up Urban Density Index and Shannon Entropy Index to identify trends and the geographical direction of transformation from 2005 to 2020. Surat is one of the fastest-growing urban centres in both the state and the nation, ranking as the 4th fastest-growing city globally. This study analyses the dynamics of urban built-up area transformations both zone-wise and geographical direction-wise, in which their trend, rate, and magnitude were calculated for the period of 15 years. This study also highlights the need for analysing and monitoring the urban growth pattern of class-I cities in India using spatio-temporal and quantitative techniques like GIS for improved urban management.

Keywords: urban expansion, built-up, geographic information system, remote sensing, Shannon’s entropy

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Authors: Kewei Fan, Sihong Liu, Yi Pik Cheng

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This paper aims to analyse the failure behaviour of the retaining wall constructed with soil bags that are formed by filling river sand into woven bags (geosynthetics). Model tests were conducted to obtain the failure mode of the wall, and shear tests on two-layers and five-layers of soil bags were designed to investigate the mechanical characteristics of the interface of soil bags. The test results show that the slip surface in the soil bags-constructed retaining wall is ladder-like due to the inter-layer insertion of soil bags, and the wall above the ladder-like surface undergoes a rigid body translation. The insertion strengthens the shear strength of two-layer staggered-stacked soil bags. Meanwhile, it affects the shape of the slip surface of the five-layer staggered-stacked soil bags. Finally, the interlayer resisting friction of soil bags is found to be related to the shape of the slip surface.

Keywords: geosynthetics, retaining wall, soil bag, failure mode, interface, shear strength

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Authors: Ndumbe Eric Esongami, Manga Veronica Ebot, Foba Josepha Tendo, Yengong Fabrice Lamfu, Tiku David Tambe

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The prevalence and unpleasant nature of plastics pollution constantly observed on beach shore on stormy events has prompt researchers worldwide to thesis on sustainable economic and environmental designs on plastics, especially in Cameroon, a major touristic destination in the Central Africa Region. The inconsistent protocols develop by researchers has added to this burden, thus the morphological nature of microplastic remediation is a call for concerns. The prime aim of the study is to morphologically identify, quantify and forensically understands the distribution of each plastics polymer composition. Duplicates of 2×2 m (4m2) quadrants were sampled in each beach/month over 8 months period across five purposive beaches along the Limbe – Idenau coastline, Cameroon. Collected plastic samples were thoroughly washed and separation done using a 2 mm sieve. Only particles of size, < 2 mm, were considered and forward follow the microplastics laboratory analytical processes. Established step by step methodological procedures of particle filtration, organic matter digestion, density separation, particle extraction and polymer identification including microscope and were applied for the beach microplastics samples. Microplastics were observed in each sample/beach/month with an overall abundance of 241 particles/number weighs 89.15 g in total and with a mean abundance of 2 particles/m2 (0.69 g/m2) and 6 particles/month (2.0 g/m2). The accumulation of beach shoreline MPs rose dramatically towards decreasing size with microbeads and fiber only found in the < 1 mm size fraction. Approximately 75% of beach MPs contamination were found in LDB 2, LDB 1 and IDN beaches/average particles/number while the most dominant polymer type frequently observed also were PP, PE, and PS in all morphologically parameters analysed. Beach MPs accumulation significantly varied temporally and spatially at p = 0.05. ANOVA and Spearman’s rank correlation used shows linear relationships between the sizes categories considered in this study. In terms of polymer MPs analysis, the colour class recorded that white coloured MPs was dominant, 50 particles/number (22.25 g) with recorded abundance/number in PP (25), PE (15) and PS (5). The shape class also revealed that irregularly shaped MPs was dominant, 98 particles/number (30.5 g) with higher abundance/number in PP (39), PE (33), and PS (11). Similarly, MPs type class shows that fragmented MPs type was also dominant, 80 particles/number (25.25 g) with higher abundance/number in PP (30), PE (28) and PS (15). Equally, the sized class forward revealed that 1.5 – 1.99 mm sized ranged MPs had the highest abundance of 102 particles/number (51.77 g) with higher concentration observed in PP (47), PE (41), and PS (7) as well and finally, the weight class also show that 0.01 g weighs MPs was dominated by 98 particles/number (56.57 g) with varied numeric abundance seen in PP (49), PE (29) and PS (13). The forensic investigation of the pollution indicated that majority of the beach microplastic is sourced from the site/nearby area. The investigation could draw useful conclusions regarding the pathways of pollution. The fragmented microplastic, a significant component in the sample, was found to be sourced from recreational activities and partly from fishing boat installations and repairs activities carried out close to the shore.

Keywords: forensic analysis, beach MPs, particle/number, polymer composition, cameroon

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Authors: Mahmoud Saleh Mohammed Alkathy

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Electricity generated from renewable resources may help the transition to clean energy. A reliable energy storage system is required to use this energy properly. To do this, a high breakdown strength (Eb) and a significant difference between spontaneous polarization (Pmax) and remnant polarization (Pr) are required. To achieve this, the defect dipoles in lead free BaTiO3 ferroelectric ceramics are created using Mg2+ and Ni2+ ions as acceptor co-doping in the Ti site. According to the structural analyses, the co-dopant ions were effectively incorporated into the BTO unit cell. According to the ferroelectric study, the co-doped samples display a double hysteresis loop, stronger polarization, and high breakdown strength. The formation of oxygen vacancies and defect dipoles prevent domains' movement, resulting in hysteresis loop pinching. This results in increased energy storage density and efficiency. The defect dipoles mechanism effect can be considered a fascinating technology that can guide the researcher working on developing energy storage for next-generation applications.

Keywords: microstructure, defect, energy storage, effciency

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Authors: Elin Cahyaningsih, Dana Indra Sensuse, Wahyu Catur Wibowo, Sofiyanti Indriasari

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Bureaucracy reform program drives Indonesian government to change their management and supporting unit in order to enhance their organization performance. Information technology as one of supporting unit became one of strategic plan that organization tried to improve, because IT can automate and speed up process, reduce business process life cycle become more effective and efficient. Knowledge management system is a technology application for supporting knowledge management implementation in government which is requirement based on problem and potential functionality of each knowledge management process. Define knowledge management that suitable for each organization it is difficult, that why we should make the knowledge management system strategy as an alignment of knowledge management process in the organization. Knowledge management system is one of information system development in people perspective, because this system has high dependency in human interaction and participation. Strategic plan for developing knowledge management system can be determine using some of information system strategic methods. This research conducted to define type of strategic method of information system, stage of activity each method, the strategic method strength and weakness. The author use literature review methods for identify and classify strategic methods of information system for differentiate method type, categorize common activities, strength and weakness. Result of this research are determine and compare six strategic information system methods, there are Balanced Scorecard, Five Force Porter, SWOT analysis, Value Chain Analysis, Risk Analysis and Gap Analysis. Balanced Scorecard and Risk Analysis believe as common strategic method that usually used and have the highest excellence strength.

Keywords: knowledge management system, balanced scorecard, five force, risk analysis, gap analysis, value chain analysis, SWOT analysis

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Authors: Yoshinori Kitsutaka, Fumiya Ikedo

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In this study, the mechanical model of various anchors embedded in gypsum board subjected cyclic shear loading were investigated. Shear tests for anchors embedded in 200 mm square size gypsum board were conducted to measure the load - load displacement curves. The strength of the gypsum board was changed for three conditions and 12 kinds of anchors were selected which were ordinary used for gypsum board anchoring. The loading conditions were a monotonous loading and a cyclic loading controlled by a servo-controlled hydraulic loading system to achieve accurate measurement. The fracture energy for each of the anchors was estimated by the analysis of consumed energy calculated by the load - load displacement curve. The effect of the strength of gypsum board and the types of anchors on the shear properties of gypsum board anchors was cleared. A numerical model to predict the load-unload curve of shear deformation of gypsum board anchors caused by such as the earthquake load was proposed and the validity on the model was proved.

Keywords: gypsum board, anchor, shear test, cyclic loading, load-unload curve

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Authors: Mohammed Alhadi Ebrahiem

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This study was designed to investigate the effect of breed and feeding level before slaughter on the skin\leather quality of the three main breeds of Sudan goats. Thirty (30) pieces of fresh skins from the three goat breeds (an average age 1-1.5 years) were chosen for the study purpose. For whole variations between the three breeds in two levels of feeding (poor and rich pastures) Complete Randomized Design (CRD) was used for data analysis. The results revealed that, leather weight (kg), elongation%, tensile strength (kg/cm2), cracking load (kg), thickness (mm), tear load (kg/cm) and chrome% findings were significantly affected (P≥0.05) by breed variation. Flexibility, moisture%, Ash% and fat % were not significantly affected (P ≥ 0.05) by breed. On the other hand, skin weight (kg), Cracking load (kg), Tear load (kg/cm) and Ash% were significantly affected (P≥0.05) by pasture quality. While Leather Elongation%, Tensile strength (kg/cm2), Thickness (mm), Flexibility, Moisture%, Fat % and Chrome% were not statistically (P ≥ 0.05) affected by pastures quality.

Keywords: skin\leather quality, goats leather, natural pasture, Sudan

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Authors: Ashish Kumar Agrahari, Amit Kumar

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Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal blood disorder that manifests with hemolytic anemia, thrombosis, and peripheral blood cytopenias. The disease is caused by the deficiency of two glycosylphosphatidylinositols (GPI)-anchored proteins (CD55 and CD59) in the hemopoietic stem cells. The deficiency of GPI-anchored proteins has been associated with the somatic mutations in phosphatidylinositol glycan class A (PIGA). However, the mutations that do not cause PNH is associated with the multiple congenital anomalies-hypotonia-seizures syndrome 2 (MCAHS2). To best of our knowledge, no computational study has been performed to explore the atomistic level impact of PIGA mutations on the structure and dynamics of the protein. In the current work, we are mainly interested to get insights into the molecular mechanism of PIGA mutations. In the initial step, we screened the most pathogenic mutations from the pool of publicly available mutations. Further, to get a better understanding, pathogenic mutations were mapped to the modeled structure and subjected to 50ns molecular dynamics simulation. Our computational study suggests that four mutations are highly vulnerable to altering the structural conformation and stability of the PIGA protein, which illustrates its association with PNH and MCAHS2 phenotype.

Keywords: homology modeling, molecular dynamics simulation, missense mutations PNH, MCAHS2, PIGA

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Authors: Muhammad Luqman, Yusuf Kurniawan

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S-Boxes is one of the linear parts of the cryptographic algorithm. The existence of S-Box in the cryptographic algorithm is needed to maintain non-linearity of the algorithm. Nowadays, modern cryptographic algorithms use an S-Box as a part of algorithm process. Despite the fact that several cryptographic algorithms today reuse theoretically secure and carefully constructed S-Boxes, there is an evaluation characteristic that can measure security properties of S-Boxes and hence the corresponding primitives. Analysis of an S-Box usually is done using manual mathematics calculation. Several S-Boxes are presented as a Truth Table without any mathematical background algorithm. Then, it’s rather difficult to determine the strength of Truth Table S-Box without a mathematical algorithm. A comprehensive analysis should be applied to the Truth Table S-Box to determine the characteristic. Several important characteristics should be owned by the S-Boxes, they are Nonlinearity, Balancedness, Algebraic degree, LAT, DAT, differential delta uniformity, correlation immunity and global avalanche criterion. Then, a comprehensive tool will be present to automatically calculate the characteristics of S-Boxes and determine the strength of S-Box. Comprehensive analysis is done on a deterministic process to produce a sequence of S-Boxes characteristic and give advice for a better S-Box construction.

Keywords: cryptographic properties, Truth Table S-Boxes, S-Boxes characteristic, deterministic process

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Authors: Yungeng Xie, Cong Liu, Yi Liu, Xuanao Wan

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The study aims to explore microblog users’ emotion expression and sharing behaviors on the Chinese microblog (Weibo). The first theme of study analyzed whether microblog emotions impact readers’ message sharing behaviors, specifically, how the strength of emotion (positive and negative) in microblog messages facilitate/inhibit readers’ sharing behaviors. The second theme compared the differences among the three types of microblog users (i.e., verified enterprise users, verified individual users and unverified users) in terms of their profiles and microblog behaviors. A total of 7114 microblog messages about 24 hot public events in China were sampled from Sina Weibo. The first study results show that strength of negative emotions that microblog messages carry significantly increase the possibility of the message being shared. The second study results indicate that there are significant differences across the three types of users in terms of their emotion expression and its influence on microblog behaviors.

Keywords: emotion expression, information diffusion, microblog, sharing

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Authors: A. K. Tsafe

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The study investigates the efficacy of Special Mathematics Teaching Strategy (SMTS) as against Conventional Mathematics Teaching Strategy (CMTS) in teaching students identified with Mathematics Learning Disabilities (MLDs) – dyslexia, Down syndrome, dyscalculia, etc., in some junior secondary schools around Sokoto metropolis. Errors and misconceptions in learning Mathematics displayed by these categories of students were observed. Theory of variation was used to provide a prism for viewing the MLDs from theoretical perspective. Experimental research design was used, involving pretest-posttest non-randomized approach. Pretest was administered to the intact class taught using CMTS before the class was split into experimental and control groups. Experimental group of the students – those identified with MLDs was taught with SMTS and later mean performance of students taught using the two strategies was sought to find if there was any significant difference between the performances of the students. A null hypothesis was tested at α = 0.05 level of significance. T-test was used to establish the difference between the mean performances of the two tests. The null hypothesis was rejected. Hence, the performance of students, identified with MLDs taught using SMTS was found to be better than their earlier performance taught using CMTS. The study, therefore, recommends amongst other things that teachers should be encouraged to use SMTS in teaching mathematics especially when students are found to be suffering from MLDs and exhibiting errors and misconceptions in the process of learning mathematics.

Keywords: disabilities, errors, learning, misconceptions

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Authors: Renz Paolo B. Ramos, Jake S. Espina

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The Local Government Academy of the Philippines explains that Local legislation is both a power and a process by which it enacts ordinances and resolutions that have the force and effect of law while engaging with a range of stakeholders for their implementation. Legislative effectiveness is crucial for the development of any given area. This study's objective is to evaluate the legislative performance of the 10th Sangguniang of Kawayan, a legislative body in a fifth-class municipality in the Province of Biliran, during the height of the COVID-19 pandemic (2019-2021) with a focus on legislation, accountability, and participation, institution-building, and intergovernmental relations. The aim of the study was that a mixed-methods strategy was used to gather data. The Local Legislative Performance Appraisal Form (LLPAF) was completed, while Focus Interviews for Local Government Unit (LGU) personnel, a survey questionnaire for constituents, and ethnographic diary-writing were conducted. Convenience Sampling was utilized for LGU workers, whereas Simple Random Sampling was used to identify the number of constituents participating. Interviews were analyzed using thematic analysis, while frequency data analysis was employed to describe and evaluate the nature and connection of the data to the underlying population. From this data, the researchers draw opportunities and challenges met by the local legislature during the height of the pandemic.

Keywords: local legislation, local governance, legislative effectiveness, legislative analysis

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Authors: Raghabendra Yadav, Baochun Chen, Huihui Yuan, Zhibin Lian

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Concrete Filled Steel Tube (CFST) columns are widely used in Civil Engineering Structures due to their abundant properties. CFST-RC column is a built up column in which CFST members are connected with RC web. The CFST-RC column has excellent static and earthquake resistant properties, such as high strength, high ductility and large energy absorption capacity. CFST-RC columns have been adopted as piers in Ganhaizi Bridge in high seismic risk zone with a highest pier of 107m. The experimental investigation on scaled models of similar type of the CFST-RC pier are carried out. The experimental investigation on scaled models of similar type of the CFST-RC pier are carried out. Under cyclic loading, the hysteretic performance of CFST-RC columns, such as failure modes, ductility, load displacement hysteretic curves, energy absorption capacity, strength and stiffness degradation are studied in this paper.

Keywords: CFST, cyclic load, Ganhaizi bridge, seismic performance

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Authors: Benedictus Asriparusa

Abstract:

Solar radiation is a green renewable energy which has the potential to answer the needs of energy problems on the period. Knowing how to estimate the strength of the solar radiation force may be one solution of sustainable energy development in an integrated manner. Unfortunately, a fairly extensive area of Indonesia is still very low availability of solar radiation data. Therefore, we need a method to estimate the exact strength of solar radiation. In this study, author used a model Reference Evaluation of Solar Transmittance, 2 Bands (REST 2). Validation of REST 2 model has been performed in Spain, India, Colorado, Saudi Arabia, and several other areas. But it is not widely used in Indonesia. Indonesian region study area is represented by the area of Semarang, Central Java. Solar radiation values estimated using REST 2 model was then verified by field data and gives average RMSE value of 6.53%. Based on the value, it can be concluded that the model REST 2 can be used to estimate the value of solar radiation in clear sky conditions in parts of Indonesia.

Keywords: estimation, solar radiation power, REST 2, solar transmittance

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Authors: Erion Luga, Aksel Seitllari, Kemal Pervanqe

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This study investigates the relation between physical and mechanical properties of concrete paving stones using neuro-fuzzy approach. For this purpose 200 samples of concrete paving stones were selected randomly from different sources. The first phase included the determination of physical properties of the samples such as water absorption capacity, porosity and unit weight. After that the indirect tensile strength test and compressive strength test of the samples were performed. İn the second phase, adaptive neuro-fuzzy approach was employed to simulate nonlinear mapping between the above mentioned physical properties and mechanical properties of paving stones. The neuro-fuzzy models uses Sugeno type fuzzy inference system. The models parameters were adapted using hybrid learning algorithm and input space was fuzzyfied by considering grid partitioning. It is concluded based on the observed data and the estimated data through ANFIS models that neuro-fuzzy system exhibits a satisfactory performance.

Keywords: paving stones, physical properties, mechanical properties, ANFIS

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Authors: Abd El-Aziz Said

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In this study, natural silica was used as an active, selective, reusable and eco-friendly catalyst for the liquid phase synthesis of iso-amyl, benzyl and cinnamyl esters. The original and calcined natural silica were characterized by TG-DTA, XRF, XRD, FTIR, SEM, and N2-sorption analysis. The surface acidity of the catalysts was determined using isopropanol dehydration and the strength of available acid sites was measured using chemisorption of pyridine (PY) and dimethyl pyridine (DMPY). The results of acidity specified that the acidic sites are of Brönsted type, while PY-TPD demonstrated that almost of the acidic sites over the surface of natural silica are of weak and intermediate strength. The catalytic activity of natural silica towards esterification of acetic acid with alcohols was extensively studied. The results revealed that natural silica had high catalytic activity with 100% selectivity to all targeted esters. In addition, the yields obtained in batch methods were 83, 81, and 80%, respectively, whereas these yields after simple distillation were improved 97, 99.5, and 90%, respectively.

Keywords: liquid-phase esterification, natural silica, acidity esters, characterization

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Authors: Khaled Mohamed Ibrahim

Abstract:

A comprehensive study on two biomaterials of NiTi and Ti-6Al-4V (Ti64) was done. Those materials were cast using vacuum arc remelting technique. As-cast structure of Ni-Ti alloy consists of NiTi matrix and some fine precipitates of Ni4Ti3. Ti-6Al-4V alloy showed a structure composed of equiaxed β grains and varied α-phase morphologies. Maximum ultimate compressive strength and reduction in height of 2042 MPa of 18%, respectively, were reported for the cast Ti64 alloy. However, minimum ultimate compressive strength of 1804 MPa and low reduction in height of 3% were obtained for the cast NiTi alloy. Wear rate of both Ni-Ti and Ti-6Al-4V alloys significantly increased at saline solution (0.9% NaCl) condition as compared to dry testing condition. Saline solution harmed the wear resistance of about 2 to 4 times compared to the dry condition. Corrosion rate of NiTi alloy at saline solution (0.9% NaCl) was (0.00038 mm/yr) is almost three times the value of Ti64 alloy (0.000171 mm/yr). The corrosion rate of Ti64 in SBF (0.00024 mm/yr) was lower than Ni-Ti (0.0003 mm/yr).

Keywords: NiTi, Ti64, vacuum casting, biomaterials

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