bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Ceramic Backing Strip from Metakaolin-Based Geopolymer with Gas Flow Holes for Welding Application
Authors: Plaichum Songphop , Kaewvilai Attaphon , Pantongsuk Thammaros , Chaysuwan Duangrudee , Tippayasam Chayanee
Published: August 2020

This research is firstly presented the thermal resistance of a ceramic backing made from metakaolin-based geopolymer for stainless steel welding. The general problems such as lack of fusion, hydrogen inclusion, porosity and corrosions of stainless steel welded specimens were found because, largely, stainless steel presents an affinity to gases as oxidation. Therefore, during welding, if these gases do not escape from the weld pool before solidification of weld metal, it results in porosities or hydrogen inclusions. In this case, it can be solved by properly using inert gas backing. The welder usually uses the steel backing plate with a gas release hole to support weld root and gas transmission for completed weld penetration and superior weld quality. Since the geopolymer shows a good property of thermal resistance, researchers are interested in using the ceramic backing made from geopolymer instead of the commercial ceramic backing. The ceramic backings from the geopolymer were designed merely in 3 types as follows: Narrow curved groove without gas release hole, narrow curved groove with gas release holes and wide curved groove with gas release holes. Consequently, two pieces of stainless steel were welded by gas tungsten arc welding and then the weld quality such as defects, porosity and root penetration of welded specimens was inspected. Moreover, the surface failure of ceramic backing after the welding process was also considered. The results revealed that ceramic backing from a geopolymer with wide curved groove and gas release holes gave completed penetration at the root when inspecting with non-destructive testing such as visual test, penetration test, and radiography test. It was concluded that the geopolymer could be used as ceramic backing in stainless steel welding by gas tungsten arc welding. Moreover, it could be used as backing for aluminum and steel welding as well.
Programmable 4D-Printed Responsive Structures
Authors: Chuayprakong Sunanta , Wanamonkol Araya , Khayandee Manuschaya
Published: August 2020

4D-printing has been emerged and developed from 3D-printing. The 4D-printing technology creates sophisticated structures in which can change over time to perform programmed functions. In this research, simply programmable 4D-printed responsive structures were designed, prepared and studied. The designed structures are influentially inspired by creatures and the customized 3D-printer was used. Magnetic crosslinked PVA was prepared and used as programmable 4D-printed responsive samples. Effect of PVA concentration on gel fraction was elucidated for the prepared crosslinked PVA. Fe3O4 particles were incorporated to the crosslinked polymer before manufacturing. Effect of speed of platform and effect of rate of syringe pump on the 4D-printed magnetic crosslinked PVA structure were investigated. Furthermore, the responsive property of the magnetic crosslinked PVA was determined.
Antimicrobial Assay on PVDF Nanofiber Membrane
Authors: Kitiniyom Kanokwan , Suwanboon Chonlada , Chanunpanich Noppavan
Published: August 2020

Many researches concentrated on development of antimicrobial membranes for many applications such as air or water filtration. Disk diffusion was well-known conventional method for antimicrobial assay. However, this method is preferable to hydrophilic materials, where inhibition zone was easily observed. For hydrophobic materials, negative test was always shown, except increase in antimicrobial loading. In this study, glucose fermentation was introduced as a new method for antimicrobial assay. The survived and viable bacteria either at the surface or attached inside the membranes could ferment glucose resulting in acid production and changing color of indicator in the glucose solution from pale orange to pink. FU8M and FA8M nanofiber membrane, loading with AgNO3 and Benzalkonium chloride (0.3-1.0%) were used as hydrophobic and hydrophilic membrane, respectively. The water absorption of these membranes took 2 h and 2 min, respectively, showing that the latter membrane improved its wettability. It is found that FU8M membrane showed no inhibition zone when the antimicrobial loading less than 1%, whereas the FA8M membrane showed inhibition zone from 8.6-14 mm, depending on antimicrobial loading. However, when glucose fermentation method was used, membranes showed the positive test after 9 hours of incubation at the antimicrobial concentration of 0.5%. Hence, this new method can be used as antimicrobial testing for membrane with simple and cost effective.
Strength and Noise Reduction of Geopolymeric Material Produced from Waste Sludge
Authors: Iamchaturapatr Janjit , Piriyakul Keeratikan
Published: August 2020

This research investigated the use of water treatment sludge (WTS) as an geopolymerized material. WTS with an initial SiO2:Al2O3 ratio of 3.25 was thermally treated at temperatures of 105, 500, 650 and 850 °C for 1 h. The powdered WTS after calcinations was reacted with alkaline-silicate solution (ASS) with different proportion between NaOH and Na2SiO3 solutions. The effect of calcining temperatures on the strength’s development of WTS geopolymer was determined. Without thermal treatment of the WTS, no strength was gained during the early stages. Samples prepared from WTR calcined at 850 °C exhibited the highest strength at all curing times. When WTS geopolymer was prepared as solid plate, the test in noise reduction was explored at various sound frequencies between 1000-10000 Hz. The average noise reduction efficiency of WTS geopolymer was 63.5% closed to the case of commercial light-weight brick at the same paste’s thickness.
Eco-Friendly Fired Clay Tiles with Greenish and Greyish Colored Incorporating Alternative Recycled Waste Materials
Authors: Wangrakdiskul Ubolrat , Maingam Purinut , Piyarat Natthakitta
Published: August 2020

This research intended to investigate the influence of rice husk ash (RHA), green glass cullet (GGC) and local white clay (LWC) in Thailand on the physical properties of fired clay tiles. Utilization of RHA and GGC were the main objectives. Proportion of RHA varying from 10-60% by weight was conducted. Specimens of mixture formulation were sintered at 950 °C. The results revealed that the formula no. A7 containing 70% GGC and 30% LWC can develop greenish color. In addition, scanning electron microscopy was carried out to characterize microstructure and found the glassy phase in fired specimen. Moreover, nepheline (Na2Al2Si2O8) and wollastonite (CaSiO3) were detected by the X-ray diffraction technique. These phases can promote the strength of fired clay tiles. Meanwhile, the specimen of formula no. B13 comprising 60% GGC, 30% LWC and 10% RHA can develop the mullite phase (3Al2O32SiO2). Effect of utilizing RHA in this formula can develop greyish color of ceramic tiles. Physical properties of formula no. A7 and B13 can achieve 30.15, 24.54 MPa of bending strength and 1.91, 11.72% of water absorption. They all can pass Thai Industrial Standard (TIS 2508-2555). The result of this study can be employed to manufacture environmentally friendly fired clay tiles.
Characterization of a Thermo-Sensitive Injectable Hydrogel as an Iloprost Delivery System for Dental Use
Authors: Limjeerajarus Chalida Nakalekha , Kreua-Ongarjnukool Narumol , Seang Sonntana , Pavasant Prasit , Niyomthai Saowapa Thumsing
Published: August 2020

Iloprost increases the expression of angiogenic factors and increases dental pulp flow, suggesting the potential of iloprost as a biomolecule to promote dental pulp regeneration. However, the methods to clinically deliver iloprost into the limited root canal area of a tooth and control its release are limited. The purpose of this study was to prepare a thermo-sensitive injectable hydrogel from pluronic F127 (PF127) for delivering iloprost to induce dental pulp regeneration. The PF127 hydrogels were fabricated using thermal crosslinking. The maximum cumulative release iloprost from the hydrogel at 25°C was 60%. No significant cytotoxicity or morphological changes were observed in human dental pulp cells (HDPCs) at any of the PF127 gel concentrations of the iloprost carrier. Moreover, the effect of the 20%wt PF127 gels containing iloprost on the expression of VEGF in HDPCs increased vascular endothelial growth factor (VEGF) gene expression at 72 h. The thermo-sensitive hydrogel at 20%wt PF127 containing iloprost could be used for prolonged drug release in dental applications.
Comparative Study on Cutting Force Simulation Using DEFORM 3D Software during High Speed Machining of Ti-6Al-4V
Authors: Prasad Kundan Kumar , Tamang Santosh Kumar , Chandrasekaran Muthumari
Published: August 2020

The finite element-based machining simulations for evaluation/computation of different machining responses (i.e., cutting temperature, tool wear, cutting force, and power/energy consumption) are investigated by number of researchers. In this work, finite element machining simulation was performed to obtain knowledge about cutting forces during machining of hard materials. Titanium alloy (Ti-6Al-4V) has been increasingly used in aerospace and biomedical applications due to high toughness and good corrosion resistance. The high speed machining (HSM) simulation of Ti-6Al-4V work-piece using carbide tool coated with TiCN has been conducted with different combination of cutting conditions for prediction of main cutting force (Fz). The simulated result obtained from Deform 3D software is validated with experimental result and it was found that the result found in good agreement. The parametric variation shows that depth of cut and feed are influencing parameters on cutting force.
A Microscopic Numerical Simulation of Carbon Dissolution in Different Coke Shapes in the Dripping Zone of Blast Furnace
Authors: Tungtrongpairoj Jennarong
Published: August 2020

The carbon dissolution of coke pieces in hot metal mainly influences the carbon content and carbon saturation temperature in the ironmaking process. The liquid metal and slag start to drop down in the dripping zone (DZ) which is located the lower part of blast furnaces. The dissolution of carbon in liquid metal and slag droplets passing the stagnant hot gas flow in the fixed coke bed of the dripping zone were observed by a multi-droplet model based on the Computational Fluid Dynamics (CFD) method. The uniform-coke pattern was set in the model following the preferred distribution of a one-layer packed bed from a water droplet experiment. The different coke shapes relating to the shape factor from 0.75-1.0 were observed in a 40mm-coke bed. For one-time drainage, the carbon dissolution slightly increased after flow in the coke bed zone and showed a high percentage on the coke surface. The concavity and convexity of coke pieces have more effect on the interaction between liquid and coke surface. Besides, the carbon dissolution can be investigated to approach the coke consumption in one coke channel and estimate the carbon content and carbon saturation temperature of liquid metal after draining.
Analysis of Peritectic Transformation Contraction of 304 Stainless Steel Using Surface Roughness
Authors: Guo Jun Li , Wen Guang Hua , Tang Ping , Fu Jiao Jiao
Published: August 2020

Peritectic transformation contraction of ferrite to austenite plays an important role in the formation of cracks for steels. In order to evaluate the peritectic transformation contraction of steels at the initial solidification, the solidification of 304 stainless steel under different cooling rates were carried out by using high temperature laser confocal microscopy, and then the surface roughness and peritectic transformation contraction were analysed in combination with the microstructure of solidified steel. The result shows that the solidification model of 304 stainless steel was ferrite-austenite model in the experiments, and peritectic transformation occurred during solidification. The residual ferrite in the as-cast structure were vermicular, skeletal and reticular in turn with the increase of cooling rate. The volume contraction caused by peritectic transformation resulted in wrinkles (surface roughness) appearing on the grain surface. The peritectic transformation contraction that was affected by surface roughness increased first and then decreased with cooling rate increasing, indicating the peritectic transformation contraction can be evaluated by the surface roughness.
Aroma Finishing and Pigment Printing of Thai Silk Fabric by 1-Step All-In Printing Process
Authors: Setthayanond Jantip , Lim Phussadee
Published: August 2020

In this study, a combined aroma finishing and pigment printing process was investigated in order to develop 1-step, all-in aroma finishing/pigment printing process for Thai silk. Lemongrass oil microcapsules, an aroma finishing agent, was applied on silk by screen printing process and the properties of the printed fabrics were examined. Pigment printing was also performed individually by screen printing and the colorimetric properties of the print were measured. Binder content affected the print properties of both aroma microcapsules and pigment on silk. An appropriate binder content was chosen at 20 g/100 g print paste. The 1-step, all-in aroma finishing/pigment printing process was performed by printing both lemongrass oil microcapsules and pigment simultaneously on silk fabrics. The process efficiency was determined in two different aspects i.e. aroma finishing effect and coloring effect. Aroma finishing effect of the 1-step, all-in process was examined in comparison with the individual microcapsule print results while the coloring effect was compared between the printed fabric from 1-step, all-in process and the individual pigment printing. The results showed that the 1-step, all-in process could provide comparable aroma finishing effect and pigment print quality to the separated finishing and pigment printing processes.
Investigation on the Effects of Acetone Vapor-Polishing to Fracture Behavior of ABS Printed Materials at Different Operating Temperature
Authors: Tuazon Brian Jumaquio , Espino Michaela Tayag , Dizon John Ryan Cortez
Published: August 2020

Fused Deposition Modelling (FDM) technology is one of most common technique used in 3D printing as of today for several reasons such as it is low cost and high speed printing capacity. However, common characteristic of FDM 3D printed materials are poor layer adhesion strength and rough surface finish which requires post-processing to improve it. Heat treatment and vapor-polishing are post-processing techniques used to address the poor layer adhesion and rough surface finish of 3D printed materials, respectively. This study will combine these two post-processing techniques and investigate its effect on the mechanical properties of 3D printed materials. The present study describes the effect of acetone vapor-polishing to facture behavior of ABS 3D printed material at higher operating temperatures. The study will compare the fracture behavior of ABS 3D-printed material when polished using acetone vapor bath and tested at high operating temperature to unpolished material. Five replications for each test condition were conducted. All experiment was carried out using ASTM Izod Type E tests with a 2.75J pendulum. The results showed that acetone vapor polishing strongly affects the fracture behavior of ABS 3D printed materials when operating at high temperature.
Study on Surface Structure and Properties of Titanium Alloy Modified by Ion Nitriding
Authors: Liu Yong , Lao Xing Sheng , Dai Chun Hui , Yao Shi Wei
Published: August 2020

TC4 titanium alloy was treated by ion nitriding. The structure of nitriding layer was analyzed by scanning electron microscopy. The depth and microhardness of nitriding layer were measured. The frictional properties of titanium alloy before and after nitriding were compared by friction test. The results show that the ion nitriding technology can form a stable nitriding layer with a depth of up to 20μm and a surface hardness of 560 HV0.2. At the same time, after nitriding, the wear resistance of the titanium alloy surface is improved. And the coefficient of friction between the friction pair is reduced.
Performance Assessment on Porous Paving Made with Fly Ash as Landscape Architecture Element in Bandung Urban Area
Authors: Krisanti Susan Hanuningrum , Triningsih Endang
Published: August 2020

This paper discusses the performance of locally made porous paving that has been applied in West Bandung, Indonesia, for almost one year. The porous paving uses fly ash and bottom ash produced by a local coal mining industry to minimize the use of cement and to reuse the industry’s waste. The porous properties of the paving corresponds substantially to the context of the high yearly rainfall in the tropical region up to 442 mm3 and to the high terrain of Lembang in 1080 meters above sea level which is best to immediately recharge ground water. In this paper, the paving’s performance is assessed for its role as a landscape architecture element by applying Vitruvius’ design theories of beauty: firmitas (by the ability to maintain shape or strength), utilitas (by its ability to infiltrate water) and venustas (by its physical appearance or signs of deterioration). The results show that the porous fly-ash paving demonstrate environmentally landscape architectural element. It will significantly contribute to the degrading quality of spatially dense urban environment of Bandung
Research on the Feasibility of Concrete Incorporating Water Purification Sludge
Authors: Wu Chung Hao , Peng Hsien Sheng , Chen How Ji
Published: August 2020

This study aims to develop the mix proportion of concrete incorporating water purification sludge (WPS), as parts of fine aggregate and consequently investigate its mechanical properties and durability. The experiments involve three sludges from Da-Nan, Lin-Nei and Nan-Hua water treatment plants in Taiwan. In addition to the control mixture without WPS, four replacement levels of 20%, 40%, 60% and 80% of fine aggregate were selected for preparing the concrete mixture. The concretes tested were designed to have three target compressive strengths of 14MPa, 18MPa and 21MPa. Test results show that the compressive strengths of the Da-Nan and Lin-Nei WPS concretes meet the design requirements, and the strength of the Nan-Hua WPS concrete is lower to be only suitable for application in low strength concretes. The shrinkage deformation of the Da-Nan and Lin-Nei WPS concretes increase with the increase of sludge replacement level, however, the shrinkage deformation decreases with the increase of the compressive strength of concrete. If the sludge replacement ratio is less than 40%, its effect on the compressive strength of the Da-Nan and Lin-Nei WPSs concrete is limited whether they are cured in water or in the air.
Utilization of Spent Coffee Ground Oil in Eco-Friendly Scouring and Reactive Dyeing Processes for Cotton
Authors: Seemork Kattika , Setthayanond Jantip , Suwanruji Potjanart , Tooptompong Porntip
Published: August 2020

In this research, utilizing of Arabica spent coffee ground oil was investigated for textile processing applications including scouring and reactive dyeing for cotton. The spent coffee ground oil was extracted using hexane and its chemical compositions were analyzed. The synthesized biosurfactant from spent coffee ground oil was investigated for use in cotton scouring. The results showed that the biosurfactant could well work as a scouring agent for cotton. Much better water absorption and reduced yellowness on cotton were achieved but higher applied concentration was needed as compared with the commercial wetting agent. It was also found that scouring efficiency of the biosurfactant could be promoted by adding alkali i.e. sodium carbonate, into a scouring bath, resulting in a satisfactory scouring level. A study on utilizing spent coffee ground oil in reactive dyeing process informs that by incorporating the oil into an aqueous dyebath to create oil/water dual-phase dyeing system, the dye exhaustion and color yield of Reactive Red 120 dye obtained on cotton could be enhanced without adding salt. This promotes a development of salt-free reactive dyeing process.
In vitro Assessment of Anti-Inflammatory and COX-2 inhibitory action of some medicinal plants
Authors: Ramadhan Usama
Published: August 2020

Objective of this research was to evaluate the anti-inflammatory and COX-2 inhibitory properties of celery, myrrh, aqueous and alcoholic fenugreek plant extracts. The Human Red Blood Cell membrane stabilization (HRBC) method was used to evaluate the anti-inflammatory effect and the Enzyme Immunoassay (EIA) was used to evaluate the COX-2 inhibitory actions. The celery extract showed excellent anti-inflammatory and COX-2 inhibition potency. The other extracts (myrrh and fenugreek) showed less activity that might indicate high efficacy of celery. This may be attributed to the plant constituents, mainly to a compound known as 3-n-butylphthalide, which is the most powerful of all healing factors of celery.
IMPORTANCIA DE LA CALIDAD DE VIDA Y LA SATISFACCIÓN LABORAL EN LAS CONDICIONES ACTUALES DE TRABAJO
Authors: Mendoza-Mestanza Geanella Vanessa
Published: August 2020

La evaluación de la calidad de vida se realiza en torno a factores como bienestar emocional, riqueza y bienestar material, salud, trabajo y otras formas de actividad productiva, relaciones familiares y sociales, seguridad e integración con la comunidad. Cada uno de estos elementos pueden ser analizados desde una mirada objetiva y subjetiva. Por otra parte, la satisfacción laboral se encuentra asociada con el bienestar. Es por esta razón que el propósito del manuscrito es discutir la bibliografía relacionada con la satisfacción laboral y la calidad de vida, así como su relevancia en las condiciones actuales de trabajo. En particular, los factores significativos de la vida laboral son la cultura organizacional, el sistema de valores, relaciones interpersonales, oportunidades de hacer carrera, sentido de reconocimiento personal, equilibrio entre la vida personal y el trabajo. En conclusión, la calidad de vida laboral cubre por completo las condiciones actuales del trabajo que promueven la satisfacción física, social, económica y las necesidades psicológicas de los empleados, en relación con el éxito de la organización. Palabras clave: Calidad de vida, bienestar, trabajo, satisfacción, felicidad.
A Value and Character Educational Model: Repercussions for Students, Teachers, and Families
Authors: Berges Puyo Jorge Gabriel
Published: August 2020

The aim of this article is to provide some insight on the implementation of a series of values in the educational system. The approach sought is holistic, considering that we weigh the effects of those values not only related to students and teachers, but also to families, government, and school administrators. This approach is new since many values and character education studies are centered on either students or teachers, or both. Also, this article tackles the concept of values and character education, adding the review of several related studies, providing valuable information about the benefits and advantages that this educational model offers based on the expectation that those values must be present in all factors of the learning process. Finally, this article delivers a reflection on those same elements with the goal to use it as a thought-provoking tool to consider more solutions to help students face academic challenges and those related to life.
A Purusit Differential Game Problem on a Closed Convex Subset of a Hilbert Space
Authors: Badakaya Abbas Ja'afaru , Muhammad Bilyaminu
Published: August 2020

We study a pursuit differential game problem with finite number of pursuers and one evader on a nonempty closed convex subset of the Hilbert space l2. Players move according to certain first order ordinary differential equations and control functions of the pursuers and evader are subject to integral constraints. Pursuers win the game if the geometric positions of a pursuer and the evader coincide. We formulated and prove theorems that are concern with conditions that ensure win for the pursuers. Consequently, wining strategies of the pursuers are constructed. Furthermore, illustrative example is given to demonstrate the result.
Portfolio Strategy for an Investor with Logarithm Utility and Stochastic Interest Rate under Constant Elasticity of Variance Model
Authors: Edikan E. Akpanibah  , Ini Udeme
Published: August 2020

This paper is aim at maximizing the expected utility of an investor’s terminal wealth; to achieve this, we study the optimal portfolio strategy for an investor with logarithm utility function under constant elasticity of variance (CEV) model in the presence of stochastic interest rate. A portfolio comprising of one risk free asset and one risky asset is considered where the risk free interest rate follows the Cox- Ingersoll-Ross (CIR) model and the risky asset is modelled by CEV. Using power transformation, change of Variable and asymptotic expansion technique, an explicit solution of the optimal portfolio strategy and the Value function is obtained. Furthermore, numerical simulations are presented to study the effect of some parameters on the optimal portfolio strategy under stochastic interest rate.
EVALUASI SARANA DAN PRASARANA PEMBELAJARAN JURUSAN TEKNIK KOMPUTER JARINGAN MENGGUNAKAN MODEL CIPP DI SMK Negeri 2 PAYAKUMBUH
Authors: Oktarina Rahmi
Published: August 2020

This article was a study about the implementation of the learning facilities and infratructures in SMKN 2 Payakumbuh in its relationship to the prior low achievement of students in some courses in Computer Network Engineering department. Evaluation method used was the context, input, process, and product (CIPP) that included in a mixed method research. Sources of qualitative data obtained from the vice headmaster of facilities and infrastructure of SMKN 2 Payakumbuh, head of Computer Network Engineering department, head of the Computer Network Engineering lab and the teachers in that department.. The quantitative data were taken from students in XI TKJ class that consisted of 32 people. The research indicated that context component is in adequate category (73.71%); the Input component is in adequate category (76.79%); the
Process component is in adequate category (78.06%) and the Product component is also in adequate category (79.58%). Due to all of components were in adequate category, it was suggested to conduct the appropriate improvement to improve the students achievements in thoses Computer Network Engineering courses.
PERANCANGAN SISTEM INFORMASI PENJUALAN BERBASIS WEB PADA HI GADGET STORE
Authors: Riki Riki
Published: August 2020

Hi Gadget Store is an electronics store that provides gadgets which requires an expansion on sales and promotion of its products for customer inside and outside Batam. Hi Gadget Store is still using Banner for its promotion and the recording transaction are still manual so it is likely to make a mistake and a data loss. At the time, the way of purchase at Hi Gadget Store are the customer directly came into the store to see and ordering products that are provided by the store. By developing a web-based sales information system on the Hi Gadget Store, it would help the store and the customer on making transactions and helps the store to promote the store’s products over the internet. The system is using DFD (Data Flow Diagram) for the method development and CMS (Content Management Software) called Opencart for the web-based system. The results of web-based sales information system research could be implemented and be a good use for the store on promoting its product and easily making transactions to the customers.
PENGELOLAAN ADMINISTRASI SURAT MASUK DAN SURAT KELUAR UNIT KERJA BAAK BERBASIS WEB
Authors: Dewi Indah Kusuma
Published: August 2020

Sekolah Tinggi Teknik (STT) Ibnu Sina Batam merupakan salah satu Perguruan Tinggi Swasta di Batam yang bertempat di Lubuk Baja. Pada STT Ibnu Sina Batam ada Bagian Administrasi Akademik (BAAK) yang menangani Persuratan yang membutuhkan data cepat dan tepat. Dalam pengelolaan surat masuk dan keluar di instansi ini masih menggunakan sistem manual sehingga prosesnya masih lambat dan kurang terjamin ketepatannya. Oleh karena itu untuk mendapatkan semua itu membutuhkan Sistem Pengelolaan Terkomputerisasi yang cepat dan tepat. Sistem Terkomputerisasi ini mengacu pada kegiatan Pengelolaan Surat Masuk dan Surat Keluar. Sistem ini dibuat dengan sistem satu user dan menggunakan program PHP dan MySQL. Dari Pengelolaan Surat Masuk dan Surat Keluar Unit BAAK STT Ibnu Sina yang dibuat, diharapkan mampu menghasilkan data yang tepat dan sesuai kebutuhan.
Stress, Anxiety, and Depression Symptoms in a Population Sample in The Initial Stage of The Coronavirus (COVID-19) Pandemic Outbreak
Authors: Elrefaey Samah R. I
Published: August 2020

Context: Changes in everyday life have been rapid and drastic, with the virus surge outbreaks, the death rate escalating, and stringent steps to control the disease spread increasing across regions of the world. While significant attention has been paid to efforts to diagnose people with the coronavirus infection, recognizing the mental health needs of people affected by this pandemic has been ignored relatively. The psychological impact of the Coronavirus Disease 2019 (COVID-19) outbreak and lockdown measures on the Egyptian population are unknown.

Aim: This study assesses levels of stress, anxiety, and depression symptoms in a population sample in the initial stage of the coronavirus pandemic (COVID-19) outbreak and explores its related potential risk factors.

Methods: A cross-sectional design used to conduct the study on a convenience sample of 1010 subjects residing at Benha City, Qalyubiyah Governorate, Egypt. The tool utilized in this study consists of two parts:  Self-administered questionnaire, which was designed to assess people's socio-demographic and family data, and Depression, Anxiety, and Stress Scale (DASS) that measure the symptoms of the emotional state of depression, anxiety, and stress.

Results: The result reveals a mean of total stress scale as 15.44±3.62, mean of total anxiety scale as 13.56±3.74, and mean of total depression scale as 12.41±3.86. There was a high statistically significant positive correlation between anxiety, stress, and depression at p-value <0.01.

Conclusion: This study concluded that more than two-thirds of the studied population suffered from a moderate level of stress, less than two-thirds of the studied population suffered from moderate anxiety, while around one-tenth of them were normal, and more than one-third of the studied population suffered from a moderate level of depression, while one-fifth of them were normal. The current result revealed that age (year), marital status, having children, educational level, income, and occupation were predictors of stress, anxiety, and depression. The study suggested the need for additional research on predictive factors affecting people's stress in the era of COVID-19 outbreak and carried out psychological intervention activities through various mediums to help people become more resilient during the COVID-19 epidemic.
AN INTERESTING CASE OF POLYMORPHIC VENTRICULAR TACHYCARDIA
Authors: Iqbal Sameen , Saeed Yawer
Published: August 2020

Introduction: Polymorphic ventricular tachycardia (PMVT) is described as a ventricular rhythm (>100 b/min) characterized by clearly defined QRS complexes with frequent and rapid changes in morphology, axis, or both. The clinical presentation of PMVT can range from a brief, asymptomatic, self-terminating episode to recurrent syncope or sudden cardiac death. Long QT interval is most often implicated. We report a case of a male patient presented to emergency room (ER) with syncope, generalized tonic-clonic seizures(GTCS) and PMVT. Case report: Young male, presented to ER with syncope and GTCS. Patient was initially managed in ER on the lines of status epilepticus. Patient left the hospital against medical advice and then presented again in ER within 8 hours with out of hospital cardiac arrest and had PMVT leading to pulseless electrical activity. He was resuscitated and transferred to Intensive care unit (ICU). He had recurrent PMVT, was DC-cardioverted multiple times and settled with overdrive pacing. ECG showed QTc >500msec. Patient was taking Loperamide approximately 120 tablets/day for last few months. Patient had no further episode of tachyarrhythmia since starting on B-blocker and QTc interval improved gradually. The genetic workup for congenital long QT syndrome was negative. Patient is doing well and is under regular follow-up. Conclusion: Drug induced Long QT is often an unrecognized but a common presentation in patients with ventricular arrhythmias. Arrhythmia recognition in ER/ among general practitioners, strict legislation and dispensing control in pharmacy of prescription only medications can save innumerable lives. Keywords: PMVT, Loperamide, Drug induced Long QT, QTc interval, syncope.
Os diálogos dos personagens como geradores da violência: estudo sobre filmes brasileiros
Authors: Opolski Débora
Published: August 2020

Este artigo apresenta uma reflexão sobre os diálogos dos personagens nos filmes brasileiros de ficção comercial produzidos após Cidade de Deus (2002), que possuem narrativas versando sobre organizações criminosas e tráfico de drogas. De modo geral, são filmes que possuem a palavra falada como elemento principal da narrativa. Os diálogos dos personagens deste conjunto de filmes possuem características singulares na forma da fala, que os diferenciam de outras produções. Essas características são as principais geradoras da violência, explícita e implícita. Utilizando exemplos, pretendemos demonstrar que estes filmes são estruturados na palavra falada, utilizam a palavra como um ato de fala e a transformam em símbolos que representam a violência através da linguagem diferenciada, da verborragia cômica, da hipermasculinidade ressaltada e do uso de obscenidades e palavras de baixo calão.
Estudo da transmissão audiovisual da Primeira sinfonia de Mahler pela Filarmônica de Berlim
Authors: De Oliveira Leandro Vasconcellos
Published: August 2020

O objetivo do artigo é analisar, através de processos qualitativos e quantitativos, a transmissão audiovisual do primeiro movimento da Primeira sinfonia de Gustav Mahler realizada pela Orquestra Filarmônica de Berlim, no ano de 2019. O quadro teórico de referência parte das propostas de Baxter (2019), Tsivian (2018) e Salt (1974), que propõe e atualiza o fator descrito como ASL (Average Shot Lenght). A metodologia é a análise qualitativa por descrição de comportamento e análise quantitativa por cinemétrica. Por resultado, o artigo traz reflexões sobre a dinamização em termos cinemétricos da linguagem audiovisual dos concertos para orquestra, sugerindo algumas das implicações e problemas eventuais a serem posteriormente discutidos.
EFFECT OF EARLY INTERVENTION ON THE ACTIVATION OF THE HIPOTALAMO-HIPOFISO-ADRENAL AXIS INDUCED BY THE CONSUMPTION OF SUCROSE RICH DIETS
Authors: Cerrone Gloria
Published: August 2020

The increasing prevalence of metabolic syndrome is associated, among other factors, with changes in lifestyle and the consumption of inadequate diets. Various studies indicated that the intake of an excess of fructose or sucrose can generate metabolic syndrome.
Optimal DG Location and Sizing for Minimum Active Power Loss in Radial Distribution System using Firefly Algorithm
Authors: Remha Souhaib
Published: August 2020

In this paper, a novel optimization algorithm is presented for optimal location and sizing of Distributed Generation (DG) units on distribution systems. For this purpose, a recently based meta-heuristic called Firefly Algorithm (FA) has been employed to minimize the total active power losses. The results show a considerable improved in voltage profiles of all the buses and enhance the voltage stability index. The investigations were tested on IEEE 33 bus radial distribution system. Simulation results demonstrate the effectiveness of firefly algorithm. Comparison with another method is also given.
Seasonal effect on solar distillation in the El-Oued region of south-east Algeria
Authors: Khechekhouche Abderrahmane , Boukhari Ali , Driss Zied , Benhissen Nacer eddine
Published: August 2020

In the present purely experimental work, we tested a solar distiller with a simple slope in the region of El-Oued located in the south-east of Algeria, during the winter then the summer seasons at the same place. Dimensions of the studied device are (1000 x 500 mm), while the depth of the water to be distilled is 1 cm, the glazing thickness is 4 mm, and the tilt angle with respect to the horizontal is 10 °.The aim of this work is to compare distillation between winter (January) and summer (May) to show that weather factors such as solar radiation, ambient temperature and humidity are influential on the distiller productivity. The amount of distilled water in winter was about 119 ml per day. However, that in summer was 1127 ml per day in total, so it is an increase of more than 9 times the production of distilled water.
Numerical investigation of heat transfer enhancement inside a parabolic trough solar collector using dimpled absorber
Authors: Benabderrahmane Amina
Published: August 2020

Three dimensional numerical investigation of heat transfer enhancement in a non-uniformly heated parabolic trough solar collector using dimpled absorber under turbulent flow was incorporated in the current paper. The governing equations were solved using the finite volume methods (CFD) with certain assumptions and appropriate boundary conditions. The Monte Carlo ray trace technique was applied to obtain the heat flux distribution around the absorber tube. The numerical results were validating with the empirical correlations existing in the literature and good agreement was obtained. The present results demonstrate that the inclusion of inserts provide a good performance in heat transfer,   also the receiver temperature gradient are shown to reduce with the use of geometrical modification, the absorber geometry have a remarkable effect on the HTF velocity distribution.
Structural, electronic and thermoelectric properties of the intermetallic materials based on Mg2X (X= Si, Ge, Sn): DFT calculations
Authors: Ibrir Miloud
Published: August 2020

The scope of this work is the investigation of the physical properties of chalcopyrite materials using ab-initio methods in order to simulate a new structure of thin-films photovoltaic cells with high conversion efficiency. In the first framework, we obtained the results of calculations based on Density Functional Theory (DFT) using the full-potential linearized augmented plane wave method (FP-LAPW) as involved in the WIEN2K computational package. For the exchange-correlation potential, the local density approximation (LDA) was used to calculate the lattice parameters, Bulk modulus and its first derivative as well as the densities of states of the intermetallic semiconductors materials based on Mg2X (X=Si, Ge and Sn). The semi-local Becke-Johnson (mBJ) potential and its modified form proposed by Tran and Blaha (TB-mBJ) were also used for studying the electronic and thermoelectric properties; (merit factor, Seebeck coefficient, electronic conductivity). The achieved results were compared to computational works and other data acquired experimentally.
Modeling Electric Field and Potential Distribution of an Model of Insulator in Two Dimensions by the Finite Element Method
Authors: M ziou Nassima , Benguesmia Hani , Rahali Hilal
Published: August 2020

The electrical effects can be written by two magnitudes the field and the electrostatic potential, for the determination of the distribution of the field and the electric potential along the leakage distance of the polluted insulator, the comsol multiphysics software based on the finite element method will be used. The objective of this paper is the modeling electric field and potential distribution in Two Dimensions by the Finite Element Method on a model of insulator simulating the 1512L outdoor insulator used by the Algerian company of electricity and gas (SONELGAZ). This model is under different conductivity, applied voltage, position of clean layer and width of clean layer. The computer simulations are carried out by using the COMSOL multiphysics software. This paper describes how Comsol Multiphysics have been used for modeling of the insulator using electrostatic 2D simulations in the AC/DC module. Numerical results showed a good agreement.
Economic Evaluation Analysis of Nano-silica Ultrafiltration Membrane Production from Sand
Authors: Kurnia Kurnia
Published: August 2020

The purpose of this research was to analyze the production method of a membrane of silica nanoparticles from an economic perspective. Silica nanoparticles are synthesized using a coprecipitation method. Briefly, the process consists of immersion, heating, precipitation, washing and drying, and packaging. The parameters used for economic analysis are gross profit margin (GPM), internal rate return (IRR), payback period (PBP), cumulative net present value (CNPV), break-even point (BEP), and profitability index (PI). The production of this ultrafiltration nano-silica membrane can be done by varying the amount of initial sand from 6 to 14 kg. The production of ultrafiltration nano-silica membranes can be produced in both domestic and micro-scale industries. To get a very good profit, economic analysis shows the minimum amount of sand used should be more than six kg. This study is very important because the production of ultrafiltration nano-silica membranes have a high potential in the field of economics and will encourage further investigation for the possibility of industrial production of these ultrafiltration nano silica membranes.
Control with Sliding Mode of a Five-Phase Series-Connected Two-asynchronous Motor Drive
Authors: Zouaid Omar , Nezli Lazhari
Published: August 2020

In this paper, we study sliding mode control of series-connected five-phase two asynchronous machines supplied with a three levels inverter. After presentation of multiphase machines, we worked out the mathematical model of five phase asynchronous machine supplied with voltage inverter. Application of Park transformation reduces considerably the mathematical model of machine. After, we applied vector control and sliding mode control to the five-phase induction machine. After that, we study a multi-machine system, which comport five-phase two asynchronous machines supplied with a single voltage inverter.In the last, we had the sliding mode control of series-connected five-phase two asynchronous machines. Simulations are presented to show the effectiveness of the control strategy. We observe that an appropriate transposition of phase’s order permits an independent control of two machines.
GPVDM simulation of layer thickness effect on power conversion efficiency of CH3NH3PbI3 based planar heterojunction solar cell
Authors: Hima A.bdelkader
Published: August 2020

Perovskite-based solar cell technologies have been a very attractive area of research in recent years. Organic-inorganic perovskite materials are in an increased evolution in power conversion efficiency. Inorganic materials have been tested at the laboratory level but their power conversion efficiency is still limited. In this paper, we used the GPVDM software to study the effect of some parameters on power conversion efficiency in a planar heterojunction solar cell based on CH3NH3PbI3 as an absorbing layer. The modifications were made by considering layers of perovskite without defects. The results show that the efficiency of the power conversion can be improved by adjusting layer thickness; in our case power conversion efficiency was increased from 9.96 % to 12.9 %.
Modeling and Comparative Study of Speed Sensor and Sensor-less based on TSR-MPPT Method for PMSG-WT Applications
Authors: SAIDI Youcef , MEZOUAR Abdelkader , MILOUD Yahia , BENMAHDJOUB Mohammed Amine , YAHIAOUI Maamar
Published: August 2020

The aim of this paper is to present a comparative study between two maximum power point tracking (MPPT) control based on tip speed ratio (TSR) method: maximum power control with wind speed measurement (TSR-MPCWSM) and the maximum power control with wind speed estimation (TSR-MPCWSE). These methods are analytically compared to illustrate TSR-MPPT and power smoothing capability delivered by the turbine. The dynamic performance, robustness, and fast approximation of the optimal value are proved with the simulations under MATLAB/Simulink software
Effect of the Preheating Inlet Air on the G222 Fuel Combustion
Authors: Attia Mohammed El Hadi
Published: August 2020

In this paper, a numerical simulation is developed to study the preheating effect of the air in a three-dimensional cylindrical combustion chamber using the FLUENT-CFD code. Particularly, we are interested on the calculation of the characteristic parameters such as the axial velocity, the temperature and the mass fraction of carbon monoxide. This study consists of a special treatment of mathematical models. The considered approaches resolve the governing equations of system. The main objective of this work is to study the behavior of the parameters considered previously during the variation of the air inlet temperature. The obtained results show that the variation of the inlet temperature presents a direct effect on the considered parameters.
Comparative study between pi and fuzzy pi controllers for DFIG integrated in variable speed wind turbine
Authors: Hamza Mesai Ahmed , . A. Bentaallah, Y. Djeriri, A. Mahmoudi
Published: August 2020

This paper presents the contribution of the application of fuzzy logic for the independent control of  the active and reactive power stator of a doubly fed induction generator (DFIG), used in a variable speed wind energy conversion system. So in this work, we are particularly interested in the application of indirect vector control by stator flux orientation to the DFIG, based on fuzzy controllers. These latter surpass the limits of conventional controllers and possess essential characteristics for the improvement of the robustness of the vector control with against parameters variations of the system. The obtained simulation results have shown that it is possible to control the stator powers, even in the presence of parametric variations.
Study of a solar air conditioning system with ejector
Authors: Mokhtar Ghodbane
Published: August 2020

Air conditioning is one of the indispensable conditions of well-being in human life, so the face of this research to provide this basic necessity in remote areas and in desert places far from power grids. To achieve this goal, solar air conditioning has been adopted, where the compressor was replaced by an ejector, a parabolic trough solar collector and a small pump; this means that the solar air conditioner does not need a huge amount of electrical energy to operate. This paper is studding the thermodynamic cycles of this air conditioner as a function of changing the climatic conditions of Bouzaréah region in Algeria under several practical conditions of heat exchangers (Condenser, Evaporator and Generator). This study will allow the determination of the optical and thermal efficiency of the solar collector used as a solar thermal generator, refrigeration subsystem performance (COPEje) and system thermal ratio of the air conditioner, where the cooling load is estimated at 18 kW.
Extraction of the electrical parameters of the Au/InSb/InP Schottky diode in the temperature range (300 K- 425 K)
Authors: Sadoun Ali
Published: August 2020

In this work, we have presented a theoretical study of  Au/InSb/InP Schottky diode based on current-voltage (I-V) measurement in the temperature range ( 300 K- 425 K). Electrical parameters of Au/InSb/InP such as barrier height (Φb), ideality factor and series resistance have been calculated by employing the conventional (I-V), Norde, Cheung and Chattopadhyay methods. Measurements show that the Schottky barrier height (SBH), ideality factor and series resistance, RS for Au/InSb/InP Schottky diode in the temperature range (300 K–425 K)  are 0.602-0.69eV, 1.683-1.234 and 84.54-18.95 (Ω), respectively. These parameters were extracted using Atlas-Silvaco-Tcad logical.