Search results for: high strain rate

Authors: Abhishek Priyam, Prabha Chand

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Channel depth is an important design parameter to be fixed in designing a solar air heater. In this paper, a mathematical model has been developed to study the influence of channel duct on the thermal performance of solar air heaters. The channel depth has been varied from 1.5 cm to 3.5 cm for the mass flow range 0.01 to 0.11 kg/s. Based on first law of thermodynamics, the channel depth of 1.5 cm shows better thermal performance for all the mass flow range. Also, better thermohydraulic performance has been found up to 0.05 kg/s, and beyond this, thermohydraulic efficiency starts decreasing. It has been seen that, with the increase in the mass flow rate, the difference between thermal and thermohydraulic efficiency increases because of the increase in pressure drop. At lower mass flow rate, 0.01 kg/s, the thermal and thermohydraulic efficiencies for respective channel depth remain the same.

Keywords: channel depth, thermal efficiency, wavy fin, thermohydraulic efficiency

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Authors: Ross Guest, Bjarne Jensen

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This paper analyses a potentially new consumption dividend from lower fertility arising from imperfect labour substitution by age. A smaller proportion of young workers relative to older workers raises relative youth wages given imperfect labour substitution by age. Discounted lifetime labour income rises which provides a consumption dividend. Simulation results are reported for the four Scandinavian countries, adopting a simple overlapping generations model. Imperfect labour substitution is modelled using a CRESH functional form of an aggregate labour index. The magnitudes of this new consumption dividend from a Low fertility projection compared with a high fertility projection are found to be approximately 4 percent annually, on average over the Scandinavian countries in the very long run, but somewhat lower in the short term. There is some sensitivity to the interest rate and the degree of consumption smoothing.

Keywords: fertility, consumption, productivity, labour substitution

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Authors: R. Sabre

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This work focuses on the symmetric alpha stable process with continuous time frequently used in modeling the signal with indefinitely growing variance, often observed with an unknown additive error. The objective of this paper is to estimate this error from discrete observations of the signal. For that, we propose a method based on the smoothing of the observations via Jackson polynomial kernel and taking into account the width of the interval where the spectral density is non-zero. This technique allows avoiding the “Aliasing phenomenon” encountered when the estimation is made from the discrete observations of a process with continuous time. We have studied the convergence rate of the estimator and have shown that the convergence rate improves in the case where the spectral density is zero at the origin. Thus, we set up an estimator of the additive error that can be subtracted for approaching the original signal without error.

Keywords: spectral density, stable processes, aliasing, non parametric

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Authors: Franco Primo Soffietti, Diego Fernando Turello, Federico Pinto

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Shear waves that propagate through the ground impose deformations that must be taken into account in the design and assessment of buried longitudinal structures such as tunnels, pipelines, and piles. Conventional engineering approaches for seismic evaluation often rely on a Euler-Bernoulli beam models supported by a Winkler foundation. This approach, however, falls short in capturing the distortions induced when the structure is subjected to shear waves. To overcome these limitations, in the present work an analytical solution is proposed considering a Timoshenko beam and including transverse and rotational springs. The present research proposes ground springs derived as closed-form analytical solutions of the equations of elasticity including the seismic wavelength. These proposed springs extend the applicability of previous plane-strain models. By considering variations in displacements along the longitudinal direction, the presented approach ensures the springs do not approach zero at low frequencies. This characteristic makes them suitable for assessing pseudo-static cases, which typically govern structural forces in kinematic interaction analyses. The results obtained, validated against existing literature and a 3D Finite Element model, reveal several key insights: i) the cutoff frequency significantly influences transverse and rotational springs; ii) neglecting displacement variations along the structure axis (i.e., assuming plane-strain deformation) results in unrealistically low transverse springs, particularly for wavelengths shorter than the structure length; iii) disregarding lateral displacement components in rotational springs and neglecting variations along the structure axis leads to inaccurately low spring values, misrepresenting interaction phenomena; iv) transverse springs exhibit a notable drop in resonance frequency, followed by increasing damping as frequency rises; v) rotational springs show minor frequency-dependent variations, with radiation damping occurring beyond resonance frequencies, starting from negative values. This comprehensive analysis sheds light on the complex behavior of embedded longitudinal structures when subjected to shear waves and provides valuable insights for the seismic assessment.

Keywords: shear waves, Timoshenko beams, Winkler springs, sol-structure interaction

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Authors: Jenq-Shyong Chen, Ben-Fong Yu

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CNC(computer numerical control) machining centers have been widely used for machining different metal components for various industries. For a specific CNC machine, its everyday job is assigned to cut different products with quite different attributes such as material type, workpiece weight, geometry, tooling, and cutting conditions. Theoretically, the dynamic characteristics of the CNC machine should be properly tuned match each machining job in order to get the optimal machining performance. However, most of the CNC machines are set with only a standard set of CNC parameters. In this study, we have developed an auto-tuning system which can automatically change the CNC parameters and in hence change the machine dynamic characteristics according to the selection of machining modes which are set by the mixed combination of three machine performance indexes: the HO (high surface quality) index, HP (high precision) index and HS (high speed) index. The acceleration, jerk, corner error tolerance, oscillation and dynamic bandwidth of machine’s feed axes have been changed according to the selection of the machine performance indexes. The proposed auto-tuning system of the CNC parameters has been implemented on a PC-based CNC controller and a three-axis machining center. The measured experimental result have shown the promising of our proposed auto-tuning system.

Keywords: auto-tuning, CNC parameters, machining mode, high speed, high accuracy, high surface quality

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Authors: Oliver Commichau, Richard Krimm, Bernd-Arno Behrens

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A growing demand on the production rate of modern presses leads to higher stroke rates. Commonly used material feeding devices for presses like grippers and roll-feeding systems can only achieve high stroke rates along with high gripper forces, to avoid stick-slip. These forces are limited by the sensibility of the surfaces of the workpieces. Stick-slip leads to scratches on the surface and false positioning of the workpiece. In this paper, a new contactless feeding device is presented, which develops higher feeding force without damaging the surface of the workpiece through gripping forces. It is based on the principle of the linear induction motor. A primary part creates a magnetic field and induces eddy currents in the electrically conductive material. A Lorentz-Force applies to the workpiece in feeding direction as a mutual reaction between the eddy-currents and the magnetic induction. In this study, the FEA model of this approach is shown. The calculation of this model was used to identify the influence of various design parameters on the performance of the feeder and thus showing the promising capabilities and limits of this technology. In order to validate the study, a prototype of the feeding device has been built. An experimental setup was used to measure pulling forces and placement accuracy of the experimental feeder in order to give an outlook of a potential industrial application of this approach.

Keywords: conductive material, contactless feeding, linear induction, Lorentz-Force

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Authors: Mohamed K. El-Fawkhry, Ahmed Shash, Ahmed Ismail Zaki Farahat, Sherif Ali Abd El Rahman, Taha Mattar

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High-carbon, silicon-rich steels are commonly suggested to obtain very fine bainitic microstructure at low temperature ranged from 200 to 300°C. Thereby, the resulted microstructure consists of slender of bainitic-ferritic plates interwoven with retained austenite. The advanced strength and ductility package of this steel is much dependent on the fineness of bainitic ferrite, as well as the retained austenite phase. In this article, Aluminum to Silicon ratio, and the isothermal transformation temperature have been adopted to obtain ultra high strength high carbon steel. Optical and SEM investigation of the produced steels have been performed. XRD has been used to track the retained austenite development as a result of the change in the chemical composition of developed steels and heat treatment process. Mechanical properties in terms of hardness and microhardness of obtained phases and structure were investigated. It was observed that the increment of aluminum to silicon ratio has a great effect in promoting the bainitic transformation, in tandem with improving the stability and the fineness of retained austenite. Such advanced structure leads to enhancement in the whole mechanical properties of the high carbon steel.

Keywords: high-carbon steel, silicon-rich steels, fine bainitic microstructure, retained austenite, isothermal transformation

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Authors: C. Soffritti, A. Fortini, E. Baroni, M. Merlin, G. L. Garagnani

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Aluminum alloys are widely used in many engineering applications due to their advantages such ashigh electrical and thermal conductivities, low density, high strength to weight ratio, and good corrosion resistance. However, their low hardness and poor tribological properties still limit their use in industrial fields requiring sliding contacts. Hard anodizing is one of the most common solution for overcoming issues concerning the insufficient friction resistance of aluminum alloys. In this work, the tribological behavior ofhard-anodized AW-4006 aluminum alloys in dry and lubricated conditions was evaluated. Three different hard-anodizing treatments were selected: a conventional one (HA) and two innovative golden hard-anodizing treatments (named G and GP, respectively), which involve the sealing of the porosity of anodic aluminum oxides (AAO) with silver ions at different temperatures. Before wear tests, all AAO layers were characterized by scanning electron microscopy (VPSEM/EDS), X-ray diffractometry, roughness (Ra and Rz), microhardness (HV0.01), nanoindentation, and scratch tests. Wear tests were carried out according to the ASTM G99-17 standard using a ball-on-disc tribometer. The tests were performed in triplicate under a 2 Hz constant frequency oscillatory motion, a maximum linear speed of 0.1 m/s, normal loads of 5, 10, and 15 N, and a sliding distance of 200 m. A 100Cr6 steel ball10 mm in diameter was used as counterpart material. All tests were conducted at room temperature, in dry and lubricated conditions. Considering the more recent regulations about the environmental hazard, four bio-lubricants were considered after assessing their chemical composition (in terms of Unsaturation Number, UN) and viscosity: olive, peanut, sunflower, and soybean oils. The friction coefficient was provided by the equipment. The wear rate of anodized surfaces was evaluated by measuring the cross-section area of the wear track with a non-contact 3D profilometer. Each area value, obtained as an average of four measurements of cross-section areas along the track, was used to determine the wear volume. The worn surfaces were analyzed by VPSEM/EDS. Finally, in agreement with DoE methodology, a statistical analysis was carried out to identify the most influencing factors on the friction coefficients and wear rates. In all conditions, results show that the friction coefficient increased with raising the normal load. Considering the wear tests in dry sliding conditions, irrespective of the type of anodizing treatments, metal transfer between the mating materials was observed over the anodic aluminum oxides. During sliding at higher loads, the detachment of the metallic film also caused the delamination of some regions of the wear track. For the wear tests in lubricated conditions, the natural oils with high percentages of oleic acid (i.e., olive and peanut oils) maintained high friction coefficients and low wear rates. Irrespective of the type of oil, smallmicrocraks were visible over the AAO layers. Based on the statistical analysis, the type of anodizing treatment and magnitude of applied load were the main factors of influence on the friction coefficient and wear rate values. Nevertheless, an interaction between bio-lubricants and load magnitude could occur during the tests.

Keywords: hard anodizing treatment, silver ions, bio-lubricants, sliding wear, statistical analysis

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Authors: K. Y. Chen, H. Chua, C. W. Kan

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Environmental investment is an important issue in many countries. In this study, we will first review the environmental issues related to India and their effect on the economical development. Secondly, economic data would be collected from government yearly statistics. The statistics would also include the environmental investment information of India. Finally, we would co-relate the data in order to find out the relationship between environmental investment and sustainable development in India. Therefore, in the paper, we aim to analyse the effect of an environmental investment on the sustainable development in India. Based on the economic data collected, India is in development status with fast population and GDP growth speed. India is facing the environment problems due to its high-speed development. However, the environment investment could give a positive impact on the sustainable development in India. The environmental investment is keeping in the same growth rate with GDP. Acknowledgment: Authors would like to thank the financial support from the Hong Kong Polytechnic University for this work.

Keywords: India, environmental investment, sustainable development, analysis

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Authors: Efrat Neter, Esther Brainin, Orna Baron-Epel

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Background: Connecting end-users to newly developed ICT technologies and channeling patients to new products requires an assessment of compatibility. End user’s assessment is conveyed in the concept of eHealth literacy. The study examined the association between perceived and performed eHealth literacy (EHL) in a heterogeneous age sample in Israel. Methods: Participants included 100 Israeli adults (mean age 43,SD 13.9) who were first phone interviewed and then tested on a computer simulation of health-related Internet tasks. Performed, perceived and evaluated EHL were assessed. Levels of successful completion of tasks represented EHL performance and evaluated EHL included observed motivation, confidence, and amount of help provided. Results: The skills of accessing, understanding, appraising, applying, and generating new information had a decreasing successful completion rate with increase in complexity of the task. Generating new information, though highly correlated with all other skills, was least correlated with the other skills. Perceived and performed EHL were correlated (r=.40, P=.001), while facets of performance (i.e, digital literacy and EHL) were highly correlated (r=.89, P<.001). Participants low and high in performed EHL were significantly different: low performers were older, had attained less education, used the Internet for less time and perceived themselves as less healthy. They also encountered more difficulties, required more assistance, were less confident in their conduct and exhibited less motivation than high performers. Conclusions: The association in this age-hetrogenous ample was larger than in previous age-homogenous samples. The moderate association between perceived and performed EHL indicates that the two are associated yet distinct, the latter requiring separate assessment. Features of future rapid performed EHL tools are discussed.

Keywords: eHealth, health literacy, performance, simulation

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Authors: Xin Chen

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It has been widely observed that marine food webs have significantly larger predator–prey body-size ratios compared with their terrestrial counterparts. A number of hypotheses have been proposed to account for such difference on the basis of primary productivity, trophic structure, biophysics, bioenergetics, habitat features, energy efficiency, etc. In this study, an alternative explanation is suggested based on the difference in the spatial dimensions of foraging arenas: terrestrial animals primarily forage in two dimensional arenas, while marine animals mostly forage in three dimensional arenas. Using 2-dimensional and 3-dimensional random walk simulations, it is shown that marine predators with 3-dimensional foraging would normally have a greater foraging efficiency than terrestrial predators with 2-dimensional foraging. Marine prey with 3-dimensional dispersion usually has greater swarms or aggregations than terrestrial prey with 2-dimensional dispersion, which again favours a greater predator foraging efficiency in marine animals. As an analytical tool, a Lotka-Volterra based adaptive dynamical model is developed with the predator-prey ratio embedded as an adaptive variable. The model predicts that high predator foraging efficiency and high prey conversion rate will dynamically lead to the evolution of a greater predator-prey ratio. Therefore, marine food webs with 3-dimensional foraging space, which generally have higher predator foraging efficiency, will evolve a greater predator-prey ratio than terrestrial food webs.

Keywords: predator-prey, body size, lotka-volterra, random walk, foraging efficiency

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Authors: Samia A. El-Fiky, Fouad A. Abou-Zaid, Ibrahim M. Farag, Naira M. El-Fiky

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Clomipramine hydrochloride is one of the most used tricyclic antidepressant drug in Egypt. This drug contains in its chemical structure on two benzene rings. Benzene is considered to be toxic and clastogenic agent. So, the present study was designed to assess the genotoxic effect of Clomipramine hydrochloride on somatic and germ cells in mice. Three dose levels 0.195 (Low), 0.26 (Medium), and 0.65 (High) mg/kg.b.wt. were used. Seven groups of male mice were utilized in this work. The first group was employed as a control. In the remaining six groups, each of the above doses was orally administrated for two groups, one of them was treated for 5 days and the other group was given the same dose for 30 days. At the end of experiments, the animals were sacrificed for cytogenetic and sperm examination as well as histopathological investigations by using hematoxylin and eosin stains (H and E stains) and electron microscope. Concerning the sperm studies, these studies were confined to 5 days treatment with different dose levels. Moreover, the ultrastructural investigation by electron microscope was restricted to 30 days treatment with drug doses. The results of the dose dependent effect of Clomipramine showed that the treatment with three different doses induced increases of frequencies of chromosome aberrations in bone marrow and spermatocyte cells as compared to control. In addition, mitotic and meiotic activities of somatic and germ cells were declined. The treatments with medium or high doses were more effective for inducing significant increases of chromosome aberrations and significant decreases of cell divisions than treatment with low dose. The effect of high dose was more pronounced for causing such genetic deleterious in respect to effect of medium dose. Moreover, the results of the time dependent effect of Clomipramine observed that the treatment with different dose levels for 30 days led to significant increases of genetic aberrations than treatment for 5 days. Sperm examinations revealed that the treatment with Clomipramine at different dose levels caused significant increase of sperm shape abnormalities and significant decrease in sperm count as compared to control. The adverse effects on sperm shape and count were more obviousness by using the treatments with medium or high doses than those found in treatment with low dose. The group of mice treated with high dose had the highest rate of sperm shape abnormalities and the lowest proportion of sperm count as compared to mice received medium dose. In histopathological investigation, hematoxylin and eosin stains showed that, the using of low dose of Clomipramine for 5 or 30 days caused a little pathological changes in liver tissue. However, using medium and high doses for 5 or 30 days induced severe damages than that observed in mice treated with low dose. The treatment with high dose for 30 days gave the worst results of pathological changes in hepatic cells. Moreover, ultrastructure examination revealed, the mice treated with low dose of Clomipramine had little differences in liver histological architecture as compared to control group. These differences were confined to cytoplasmic inclusions. Whereas, prominent pathological changes in nuclei as well as dilated of rough Endoplasmic Reticulum (rER) were observed in mice treated with medium or high doses of Clomipramine drug. In conclusion, the present study adds evidence that treatments with medium or high doses of Clomipramine have genotoxic effects on somatic and germ cells of mice, as unwanted side effects. However, the using of low dose (especially for short time, 5 days) can be utilized as a therapeutic dose, where it caused relatively similar proportions of genetic, sperm, and histopathological changes as those found in normal control.

Keywords: chromosome aberrations, clomipramine, mice, histopathology, sperm abnormalities

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Authors: Hicham Salhi

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This research project focuses on the numerical investigation of the mixed convection of Hybrid nanofluids in a round bottom flask commonly used in organic chemistry synthesis. The aim of this study is to improve the thermal properties of the reaction medium and enhance the rate of chemical reactions by using hybrid nanofluids. The flat bottom wall of the flask is maintained at a constant high temperature, while the top, left, and right walls are kept at a low temperature. The nanofluids used in this study contain suspended Cu and Al2O3 nanoparticles in pure water. The governing equations are solved numerically using the finite-volume approach and the Boussinesq approximation. The effects of the volume fraction of nanoparticles (φ) ranging from 0% to 5%, the Rayleigh number from 103 to 106, and the type of nanofluid (Cu and Al2O3) on the flow streamlines, isotherm distribution, and Nusselt number are examined in the simulation. The results indicate that the addition of Cu and Al2O3 nanoparticles increases the mean Nusselt number, which improves heat transfer and significantly alters the flow pattern. Moreover, the mean Nusselt number increases with increasing Rayleigh number and volume fraction, with Cu- Al2O3 hybrid nanofluid producing the best results. This research project focuses on the numerical investigation of the mixed convection of Hybrid nanofluids in a round bottom flask commonly used in organic chemistry synthesis. The aim of this study is to improve the thermal properties of the reaction medium and enhance the rate of chemical reactions by using hybrid nanofluids. The flat bottom wall of the flask is maintained at a constant high temperature, while the top, left, and right walls are kept at a low temperature. The nanofluids used in this study contain suspended Cu and Al2O3 nanoparticles in pure water. The governing equations are solved numerically using the finite-volume approach and the Boussinesq approximation. The effects of the volume fraction of nanoparticles (φ) ranging from 0% to 5%, the Rayleigh number from 103 to 106, and the type of nanofluid (Cu and Al2O3) on the flow streamlines, isotherm distribution, and Nusselt number are examined in the simulation. The results indicate that the addition of Cu and Al2O3 nanoparticles increases the mean Nusselt number, which improves heat transfer and significantly alters the flow pattern. Moreover, the mean Nusselt number increases with increasing Rayleigh number and volume fraction, with Cu- Al2O3 hybrid nanofluid producing the best results.

Keywords: bottom flask, mixed convection, hybrid nanofluids, numerical simulation

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Authors: Supriya Chatla, Anjana Male, Srikala Kamireddy

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L-asparaginase (E.C.3.5.1.1) is an anti-cancer enzyme that has been purified and characterized for decades to study and evaluate its anti-carcinogenic activity against Hodgkin’s lymphoma. The present investigation deals with screening, isolation and optimization of L-asparaginase giving fungal strain of soil samples from different areas of AP, India. L-Aspariginase activity was estimated on the basis of the pink color surrounding the growing colony. A total of 132 colonies were screened and isolated from different samples. Based on the zone diameter, L-asparaginase activity is determined, L- asparaginase activity is optimized at 28oc and Immobilized Aspariginase had more potency than the free enzymes.

Keywords: aspariginase, anticancer enzyme, Isolation, optimization

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Authors: Preetinder Kaur Randhawa

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The rural areas can be differentiated from urban areas in terms of their economic activities as rural areas are primarily involved in agricultural sector and provide natural resources whereas, urban areas are primarily involved in infrastructure sector and provide manufacturing services. Census of India defines a Census Town as an area which satisfies the following three criteria i.e. population exceeds 5000, at least 75 percent of male population engaged in non-agricultural sector and minimum population density of 400 persons per square kilometers. Urban areas can be attributed to the improvement of transport facilities, the massive decline in agricultural, especially male workers and workers shift to non-agricultural activities. This study examines the pattern, process of rural areas transformed into urban areas/ census town. The study has analyzed the various factors which are responsible for land transformation as well as the socio-economic transformation of the village population. Nilpur (CT) which belongs to Rajpura Tehsil in Patiala district, Punjab has been selected for the present study. The methodology adopted includes qualitative and quantitative research design, methods based on secondary data. Secondary data has been collected from unpublished revenue record office of Rajpura Tehsil and Primary Census Abstract of Patiala district, Census of India 2011. The results have showed that rate of transformation of a village to census town in Rajpura Tehsil has been one of highest among other villages. The census town has evolved through the evolutionary process of human settlement which grows in size, population and physical development. There must be a complete economic transformation and attainment of high level of technological development. Urban design and construction of buildings and infrastructure can be carried out better and faster and can be used to aid human habitation with the enhancement of quality of life. The study has concluded that in the selected area i.e Nilpur (CT) literacy rate has increased to 72.1 percent in year 2011 from 67.6 percent in year 2001. Similarly non-agricultural work force has increased to 95.2 percent in year 2011 from 81.1 percent in year 2001. It is very much clear that the increased literacy rate has put a positive impact on the involvement of non-agricultural workers have enhanced. The study has concluded that rural-urban linkages are important tools for understanding complexities of people livelihood and their strategies which involve mobility migration and the diversification of income sources and occupations.

Keywords: Census Town, India, Nilpur, Punjab

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Authors: Navid Zarif Karimi, Hossein Heidary, Giangiacomo Minak, Mehdi Ahmadi

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In this paper analytical model based on the mechanics of oblique cutting, linear elastic fracture mechanics (LEFM) and bending plate theory has been presented to determine the critical feed rate causing delamination in drilling of composite materials. Most of the models in this area used LEFM and bending plate theory; hence, they can only determine the critical thrust force which is an incorporable parameter. In this model by adding cutting oblique mechanics to previous models, critical feed rate has been determined. Also instead of simplification in loading condition, actual thrust force induced by chisel edge and cutting lips on composite plate is modeled.

Keywords: composite material, delamination, drilling, thrust force

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Authors: Xiao L Dai, Wen X Wei, Shuo Wang, Jia B Li, Yan Wei

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Heavy oil pollution generated from both natural and anthropogenic sources could cause significant damages to the ecological environment, due to the toxicity of some of its constituents. Nowadays, microbial remediation is becoming a promising technology to treat oil pollution owing to its low cost and prevention of secondary pollution; microorganisms are key players in the process. Compared to the free microorganisms, immobilized microorganisms possess several advantages, including high metabolic activity rates, strong resistance to toxic chemicals and natural competition with the indigenous microorganisms, and effective resistance to washing away (in open water system). Many immobilized microorganisms have been successfully used for bioremediation of heavy oil pollution. Considering the broad choices, low cost, simple process, large specific surface area and less impact on microbial activity, modified zeolite were selected as a bio-carrier for bacteria immobilization. Three strains of heavy oil-degrading bacteria Bacillus sp. DL-13, Brevibacillus sp. DL-1 and Acinetobacter sp. DL-34 were immobilized on the modified zeolite under mild conditions, and the bacterial load (bacteria /modified zeolite) was 1.12 mg/g, 1.11 mg/g, and 1.13 mg/g, respectively. SEM results showed that the bacteria mainly adsorbed on the surface or punctured in the void of modified zeolite. The heavy oil degradation efficiency of immobilized bacteria was 62.96%, higher than that of the free bacteria (59.83%). The heavy oil degradation process of immobilized bacteria accords with the first-order reaction equation, and the reaction rate constant is 0.1483 d⁻¹, which was significantly higher than the free bacteria (0.1123 d⁻¹), suggesting that the immobilized bacteria can rapidly start up the heavy oil degradation and has a high activity of heavy oil degradation. The results suggested that immobilized bacteria are promising technology for bioremediation of oil pollution.

Keywords: heavy oil pollution, microbial remediation, modified zeolite, immobilized bacteria

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Authors: Yu-Mei Tseng, Chih-Chun Wu

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As information and communication technology (ICT) has become a part of people’s lives, most teenagers born after the 1980s and grew up in internet generation are called digital natives. Meanwhile, those teenagers’ parents are called digital immigrants. They need to keep learning new skills of ICT. This study investigated that high school students helped their parents set up social network services (SNS) and taught them how to use ICT. This study applied paper and pencil anonymous questionnaires that asked the ICT learning and ICT products using in high school students’ parents. The sample size was 2,621 high school students, including 1,360 (51.9%) males and 1,261 (48.1%) females. The sample was from 12 high school and vocational high school in central Taiwan. Results from paired sample t-tests demonstrated regardless genders, both male and female high school students help mothers set up Facebook and LINE more often than fathers. In addition, both male and female high school students taught mothers to use ICT more often than fathers. Meanwhile, both male and female high school students teach mothers to use SNS more often than fathers. The results showed that intergenerational ICT teaching occurred more often between mothers and her children than fathers. It could imply that mothers play a more important role in family ICT learning than fathers, or it could be that mothers need more help regarding ICT than fathers. As for gender differences, results from the independent t-tests showed that female high school students were more likely than male ones to help their parents setup Facebook and LINE. In addition, compared to male high school students, female ones were more likely to teach their parents to use smartphone, Facebook and LINE. However, no gender differences were detected in teaching mothers. The gender differences results suggested that female teenagers offer more helps to their parents regarding ICT learning than their male counterparts. As for area differences, results from the independent t-tests showed that the high school in remote area students were more likely than metropolitan ones to teach parents to use computer, search engine and download files of audio and video. The area differences results might indicate that remote area students were more likely to teach their parents how to use ICT. The results from this study encourage children to help and teach their parents with ICT products.

Keywords: adult ICT learning, family ICT learning, ICT learning, urban-rural gap

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Authors: Hubert Klar

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High double excitation of two-electron atoms has been investigated using hyperpherical coordinates within a modified adiabatic expansion technique. This modification creates a novel fictitious force leading to a spontaneous exchange symmetry breaking at high double excitation. The Pauli principle must therefore be regarded as approximation valid only at low excitation energy. Threshold electron scattering from high Rydberg states shows an unexpected time reversal symmetry breaking. At threshold for double escape we discover a broad (few eV) Cooper pair.

Keywords: correlation, resonances, threshold ionization, Cooper pair

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Authors: Beema Akbar, Varun P. Gopi, V. Suresh Babu

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Colon cancer causes the deaths of about half a million people every year. The common method of its detection is histopathological tissue analysis, it leads to tiredness and workload to the pathologist. A novel method is proposed that combines both structural and statistical pattern recognition used for the detection of colon cancer. This paper presents a comparison among the different classifiers such as Multilayer Perception (MLP), Sequential Minimal Optimization (SMO), Bayesian Logistic Regression (BLR) and k-star by using classification accuracy and error rate based on the percentage split method. The result shows that the best algorithm in WEKA is MLP classifier with an accuracy of 83.333% and kappa statistics is 0.625. The MLP classifier which has a lower error rate, will be preferred as more powerful classification capability.

Keywords: colon cancer, histopathological image, structural and statistical pattern recognition, multilayer perception

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Authors: Sharmin Akhter, M. Salahuddin, Sukalyan Kumar Kundu, Mohammad Fahim Kadir

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Relatively insoluble candidate drug like carbamazepine (CBZ) often exhibit incomplete or erratic absorption; and hence wide consideration is given to improve aqueous solubility of such compound. Solid dispersions were formulated with an aim of improving aqueous solubility, oral bioavailability and the rate of dissolution of Carbamazepine using different hydrophyllic polymer like Polyethylene Glycol (PEG) 6000, Polyethylene Glycol (PEG) 4000, kollidon 30, HPMC 6 cps, poloxamer 407 and povidone k 30. Solid dispersions were prepared with different drug to polymer weight ratio by the solvent evaporation method where methanol was used as solvent. Drug-polymer physical mixtures were also prepared to compare the rate of dissolution. Effects of different polymer were studied for solid dispersion formulation as well as physical mixtures. These formulations were characterized in the solid state by Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). Solid state characterization indicated CBZ was present as fine particles and entrapped in carrier matrix of PEG 6000 and PVP K30 solid dispersions. Fourier Transform Infrared (FTIR) spectroscopic studies showed the stability of CBZ and absence of well-defined drug-polymer interactions. In contrast to the very slow dissolution rate of pure CBZ, dispersions of drug in polymers considerably improved the dissolution rate. This can be attributed to increased wettability and dispersibility, as well as decreased crystallinity and increase in amorphous fraction of drug. Solid dispersion formulations containing PEG 6000 and Povidone K 30 showed maximum drug release within one hour at the ratio of 1:1:1. Even physical mixtures of CBZ prepared with both carriers also showed better dissolution profiles than those of pure CBZ. In conclusions, solid dispersions could be a promising delivery of CBZ with improved oral bioavailability and immediate release profiles.

Keywords: carbamazepine, FTIR, kollidon 30, HPMC 6 CPS, PEG 6000, PEG 4000, poloxamer 407, water solubility, povidone k 30, SEM, solid dispersion

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Authors: C. C. Lv, Y. L. Sun, D. W. Zuo

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Cemented carbide balls are usually implemented in industry under the environment of high speed, high temperature, corrosiveness and strong collisions. However, its application is limited due to high fabrication cost, processing efficiency and quality. A novel eccentric lapping method with two rotatable lapping plates was proposed in this paper. A mathematical model was constructed to analyze the influence of each design parameter on this lapping method. To validate this new lapping method, an orthogonal experiment was conducted with cemented carbide balls (YG6). The simulation model was verified and the optimal lapping parameters were derived. The results show that the surface roundness of the balls reaches to 0.65um from 2um in 1 hour using this lapping method. So, using this novel lapping method, it can effectively improve the machining precision and efficiency of cemented carbide balls.

Keywords: cemented carbide balls, eccentric lapping, high precision, lapping tracks, V-groove

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Authors: Rupinder Kaur, Harjot Kaur

Abstract:

The objective of this paper is to present the study of the effect of varying thickness on rotating composite disks made from Al-SiC_P having different particle sizes. Mathematical modeling is used to calculate the effect of varying thickness with different particle sizes on rotating composite disks in radial as well as tangential directions with thermal gradients. In comparison to various particle sizes with varied thicknesses, long-term deformation occurs. The results are displayed visually, demonstrating how creep deformation decreases with changing particle size and thickness.

Keywords: creep, varying thickness, particle size, stresses and strain rates

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Authors: Chiu-Hsuan Lee, Min-Hao Yuan, Kun-Cheng Lin, Qiao-Yin Tsai, Yun-Jie Lu, Yi-Jhen Wang, Hsin-Yi Lin, Chih-Hua Hsu, Jia-Rong Jhou, Si-Ying Li, Yi-Hung Chen, Je-Lueng Shie

Abstract:

Raw food waste has a high-water content. If it is incinerated, it will increase the cost of treatment. Therefore, composting or energy is usually used. There are mature technologies for composting food waste. Odor, wastewater, and other problems are serious, but the output of compost products is limited. And bakelite is mainly used in the manufacturing of integrated circuit boards. It is hard to directly recycle and reuse due to its hard structure and also difficult to incinerate and produce air pollutants due to incomplete incineration. In this study, supercritical hydrothermal and subcritical glycolysis thermal conversion technology is used to convert biomass wastes of bakelite and raw kitchen wastes to carbon materials and biofuels. Batch carbonization tests are performed under high temperature and pressure conditions of solvents and different operating conditions, including wet and dry base mixed biomass. This study can be divided into two parts. In the first part, bakelite waste is performed as dry-based industrial waste. And in the second part, raw kitchen wastes (lemon, banana, watermelon, and pineapple peel) are used as wet-based biomass ones. The parameters include reaction temperature, reaction time, mass-to-solvent ratio, and volume filling rates. The yield, conversion, and recovery rates of products (solid, gas, and liquid) are evaluated and discussed. The results explore the benefits of synergistic effects in thermal glycolysis dehydration and carbonization on the yield and recovery rate of solid products. The purpose is to obtain the optimum operating conditions. This technology is a biomass-negative carbon technology (BNCT); if it is combined with carbon capture and storage (BECCS), it can provide a new direction for 2050 net zero carbon dioxide emissions (NZCDE).

Keywords: biochar, raw food waste, bakelite, supercritical hydrothermal, subcritical glycolysis, biofuels

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Authors: Hsueh-Ching Wu

Abstract:

Aims: This study investigated the longitudinal changes in BC were evaluated in patients with T2D who received carbohydrate-restricted diet education (CRDE), and the effects of age and sex on BC were analyzed. Design: This retrospective observational study was conducted between 2018 and 2021. A total of 6164 T2D patients were analyzed. Subjects with T2D who received CRDE (daily carbohydrate intake: 26-45%). A hierarchical linear model (HLM) was used to estimate the change amount and rate of change for the following variables in each group: body weight (BW), body mass index (BMI), body fat mass (BFM), percent body fat (PBF), appendicular skeletal muscle mass (ASM), and skeletal muscle index (SMI). Results: The BW, BMI, ASM, SMI and BFM of T2D patients who received CRDE for 3 years decreased with increasing age; PBF showed the opposite trend. The changes in BW, BMI, ASM, and SMI of patients older than 65 years were higher than those of patients younger than 65 years, and the annual rate of decline for males was higher than that for females. The annual change in BFM and PBF for both sexes changed from a downward trend before the age of 65 to a slow increase after the age of 65, and the slow increase rate for women was higher than that for men. Conclusion: Changes in body composition are associated with age and sex. BW and muscle tissue decrease with age, and attention must be paid to the rebound of adipose tissue after middle age. Patient or Public Contribution: The patient agreed to participate in a retrospective chart review during in the study period.

Keywords: body weight, body composition, carbohydrate-restricted diet, nursing, type 2 diabetes

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Authors: Kohei Shimasaki, Tomoaki Okamura, Idaku Ishii

Abstract:

We propose a vibration imaging method for high frame rate (HFR)-video-based localization of vibrating objects with large translations. When the ratio of the translation speed of a target to its vibration frequency is large, obtaining its frequency response in image intensities becomes difficult because one or no waves are observable at the same pixel. Our method can precisely localize moving objects with vibration by virtually translating multiple image sequences for pixel-level short-time Fourier transform to observe multiple waves at the same pixel. The effectiveness of the proposed method is demonstrated by analyzing several HFR videos of flying insects in real scenarios.

Keywords: HFR video analysis, pixel-level vibration source localization, short-time Fourier transform, virtual translation

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Authors: Feng-Tsung Cheng, Shu-Li Wang, Mei-Fang Wu, , Hui-Yu Chuang

Abstract:

Due to the rapid development of modern technology, the widespread usage of the Internet makes business environment changing quickly. In order to be a leader in the global competitive market and to pursuit survive, “changing” becomes an unspoken rules need to follow for the company survival. The purpose of this paper is to build change model by using SWOT, strategy map, and balance scorecard, KPI and change management theory. The research findings indicate that organizational change plan formulated by the case company should require the employee to resist change factors and performance management system issues into consideration and must be set organizational change related programs, such as performance appraisal reward system, consulting and counseling mechanisms programs to improve motivation and reduce staff negative emotions. Then according to the model revised strategy maps and performance indicators proposed in this paper, such as strategy maps add and modify corporate culture, improve internal processes management, increase the growth rate of net income and other strategies. The performance indicators are based on strategy maps new and modified by adding net income growth rate, to achieve target production rate, manpower training achievement rates and other indicators, through amendments to achieve the company’s goal, be a leading brand of precision machinery industry.

Keywords: organizational change, SWOT analysis, strategy maps, performance indicators

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Authors: Harmeet Pal Singh Dhooria, Deepinder Chinna, UPS Sidhu, Alok Jain

Abstract:

Serious infections caused by gram-negative bacteria are a significant cause of mortality and morbidity in the hospital setting. In acute care facilities like in intensive care units (ICUs), the intensity of antimicrobial use together with a population highly susceptible to infection, creates an environment, which facilitates both emergence and transmission of Extended Spectrum -lactamase (ESBL) producing Enterobacteriaceae species. The study was conducted in the Medical Intensive Care Unit (MICU) and the Pulmonary Critical Care Unit (PCCU) of the Department of Medicine, Dayanand Medical College and Hospital, Ludhiana, Punjab, India. Out of a total of 1108 samples of urine, blood and respiratory tract secretions received for culture and sensitivity analysis from Medical Intensive Care Unit and Pulmonary Critical Care Unit, a total of 170 isolates of Enterobacteriaceae species were obtained which were then included in our study. Out of these 170 isolates, confirmed ESBL production was seen in 116 (68.24%) cases. E.coli was the most common species isolated (56.47%) followed by Klebsiella (32.94%), Enterobacter (5.88%), Citrobacter (3.53%), Enterobacter (0.59%) and Morganella (0.59%) among the total isolates. The rate of ESBL production was more in Klebsiella (78.57%) as compared to E.coli (60.42%). ESBL producers were found to be significantly more common in patients with prior history of hospitalization, antibiotic use, and prolonged ICU stay. Also significantly increased the prevalence of ESBL related infections was observed in patients with a history of catheterization or central line insertion but not in patients with the history of intubation. Patients who had an underlying malignancy had significantly higher prevalence of ESBL related infections as compared to other co-morbid illnesses. A slightly significant difference in the rate of mortality/LAMA was observed in the ESBL producer versus the non-ESBL producer group. The rate of mortality/LAMA was significantly higher in the ESBL related UTI but not in the ESBL related respiratory tract and bloodstream infections. ESBL producing isolates had significantly higher rates of resistance to Cefepime and Piperacillin/Tazobactum, and to non β-lactum antibiotics like Amikacin and Ciprofloxacin. The level of resistance to Imipenem was lower as compared to other antibiotics. However, it was noted that ESBL producing isolates had higher levels of resistance to Imipenem as compared to non-ESBL producing isolates. Conclusion- The prevalence of ESBL producing organisms was found to be very high (68.24%) among Enterobacteriaceae isolates in our ICU setting as among other ICU care settings around the world.

Keywords: enterobacteriaceae, extended spectrum B-lactamase (ESBL), ICU, antibiotic resistance

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Authors: Pius W. Molo Chin

Abstract:

Real life problems such as the Huxley equation are always modeled as nonlinear differential equations. These problems need accurate and reliable methods for their solutions. In this paper, we propose a nonstandard finite difference method in time and the Galerkin combined with the compactness method in the space variables. This coupled method, is used to analyze a two dimensional Huxley equation for the existence and uniqueness of the continuous solution of the problem in appropriate spaces to be defined. We proceed to design a numerical scheme consisting of the aforementioned method and show that the scheme is stable. We further show that the stable scheme converges with the rate which is optimal in both the L2 as well as the H1-norms. Furthermore, we show that the scheme replicates the decaying qualities of the exact solution. Numerical experiments are presented with the help of an example to justify the validity of the designed scheme.

Keywords: Huxley equations, non-standard finite difference method, Galerkin method, optimal rate of convergence

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Authors: Khalid Iqbal, Saima Altaf, M. Akram, Muhammad Abdur Rafaye, Saeed Ahmad Buzdar

Abstract:

Objective: Verification of patient-specific intensity modulated radiation therapy (IMRT) plans using different 2-D detectors has become increasingly popular due to their ease of use and immediate readout of the results. The purpose of this study was to test and compare various 2-D detectors for dosimetric quality assurance (QA) of intensity-modulated radiotherapy (IMRT) with the vision to find alternative QA methods. Material and Methods: Twenty IMRT patients (12 of brain and 8 of the prostate) were planned on Eclipse treatment planning system using Varian Clinac DHX on both energies 6MV and 15MV. Verification plans of all such patients were also made and delivered to Map check2, EPID (Electronic portal imaging device) and Gafchromic EBT3. Gamma index analyses were performed using different criteria to evaluate and compare the dosimetric results. Results: Statistical analysis shows the passing rate of 99.55%, 97.23% and 92.9% for 6MV and 99.53%, 98.3% and 94.85% for 15 MV energy using a criteria of ±5% of 3mm, ±3% of 3mm and ±3% of 2mm respectively for brain, whereas using ±5% of 3mm and ±3% of 3mm gamma evaluation criteria, the passing rate is 94.55% and 90.45% for 6MV and 95.25%9 and 95% for 15 MV energy for the case of prostate using EBT3 film. Map check 2 results shows the passing rates of 98.17%, 97.68% and 86.78% for 6MV energy and 94.87%,97.46% and 88.31% for 15 MV energy respectively for brain using a criteria of ±5% of 3mm, ±3% of 3mm and ±3% of 2mm, whereas using ±5% of 3mm and ±3% of 3mm gamma evaluation criteria gives the passing rate of 97.7% and 96.4% for 6MV and 98.75%9 and 98.05% for 15 MV energy for the case of prostate. EPID 6 MV and gamma analysis shows the passing rate of 99.56%, 98.63% and 98.4% for the brain, 100% and 99.9% for prostate using the same criteria as for map check 2 and EBT 3 film. Conclusion: The results demonstrate excellent passing rates were obtained for all dosimeter when compared with the planar dose distributions for 6 MV IMRT fields as well as for 15 MV. EPID results are better than EBT3 films and map check 2 because it is likely that part of this difference is real, and part is due to manhandling and different treatment set up verification which contributes dose distribution difference. Overall all three dosimeter exhibits results within limits according to AAPM report.120.

Keywords: gafchromic EBT3, radiochromic film dosimetry, IMRT verification, EPID

Procedia PDF Downloads 408