bluuebunny/crossref_metadata_2025 huggingface dataset:
IS COVID-19 A PANDEMIC OF INEQUALITY AND URBANIZATION?
Authors:   Birkbeck College (University of London), Malet Street, London, Lang Peter F.
Published: November 2022

Aim of the study: The aim is to determine whether inequality and urbanization are factors influencing the development of this pandemic. Design/methodology: The methodology of the study is to analyse infection data of eight individual countries that are available from the World Health Organization and determine if per capita GDP, population, population density, air travel and population size of the capital cities are factors affecting the spread of the pandemic. Findings: The study results show that socioeconomics and air travel are factors which enhance the spread of infection. Originality/value: The study is an important contribution to understanding the development of the pandemic and factors enhancing the spread of infection and can assist governments to plan control measures for future pandemics. Key words: Social inequality, urbanization, infection control, infection rates, disease transmission Paper type: Research paper
A Course or a Pathway? Addressing French as a Second Language Teacher Recruitment and Retention in Canadian BEd Programs
Authors: Smith Cameron W. , Masson Marie-Emilie , Spiliotopoulos Valia , Kristmanson Paula
Published: November 2022

Institutions strive to offer programs that address both the needs of the educational system and incorporate current pedagogical research. Creating a program that is relevant, inspiring, and accessible to aspiring French as a Second Language (FSL) teachers, while also equipping them with the skills and knowledge deemed necessary by the education system, is a delicate balancing act. This study reviewed 44 FSL teacher education programs that lead to professional certification across Canada. Environmental scans drew information from the program websites related to admission requirements, program structure and content, practicum, and graduation criteria. Follow-up interviews with program stakeholders were conducted to verify or clarify the data. The results highlight the inconsistencies that exist among programs for developing FSL educators. We position the ways in which Canadian faculties of education might provide a more holistic “pathway” approach to recruiting, preparing, and retaining emerging FSL teachers.
The Impact of Advanced Economy Monetary Policy on Gold Price Dynamics in India
Authors:   Ph.D Scholar, Department of Finance, University of Mumbai, Mumbai (Maharashtra), India., Anthony Ms. Jessica Maria , Gupta. Shri Ramesh Kr. ,   Research Officer (Manager), Reserve Bank of India (RBI), India., Chinngaihlian Ms. Sona ,   Research Officer (Manager), Reserve Bank of India (RBI), India.
Published: November 2022

Gold remains a dynamic investment tool in many economies and is considered a safe- haven during times of crises. The sheer size of the US economy and hence any monetary policy decisions have implications for the global economy and global assets. Since commodities are priced in the US dollar, transmission of shocks to asset prices is bound to happen as investors rebalance portfolio. Now, the direction of movement in gold prices depends on other factors as well. Against this backdrop, we examine the impact of US monetary policy on gold prices in India and try to examine how monetary policy announcements during the pandemic by the Fed has influenced domestic gold prices. Further, we investigate the determinants of domestic gold prices using an ARDL model and find that prices have moved closely with global economic policy uncertainty, thereby demonstrating its safe haven feature and have risen with domestic CPI inflation, thus proving to be an inflation hedge. Thus, the study is expected to upgrade the understanding on the behaviour of investors towards gold, and information processing under uncertainty. JEL Classification: G10, G15.
The Performance Analysis of Optimized Integrated Framework for Smart Grid
Authors:   Research Scholar, Department of Computer Science &  Applications, MD University, Rohtak (Haryana), India., Kumar Naveen , Singh Dr. Gopal ,   Assistant Professor, Department of Computer Science  & Applications, MD University, Rohtak (Haryana), India.
Published: November 2022

Supervisory Control and Data Acquisition system are monitoring and controlling system. It focuses on the supervisory level, not the full control permissions. It is gathering real-time data with the help of several kinds of sensors. Internet of Things (IoT) is a three-dimension any time, any place anything connectivity for anything. This paper performing the comparison between the SCADA and optimization framework for smart grid. A power quality model is integrated with the optimization framework. Moreover, this paper focused on the comparison of optimized framework with SCADA.
Impact of Heart Disease History on Safety of Telemedicine Cardiac Clearance Appointments
Authors: Siegel Nicholas , Lambrechts Mark J. , Issa Tariq Z. , Karamian Brian A. , Wang Jasmine , Carter Michael , Lieb Zachary , Zaworski Caroline , Dambly Julia , Canseco Jose A. , Woods Barrett , Kaye David , Rihn Jeffrey , Kurd Mark , Hilibrand Alan S. , Kepler Christopher K. , Vaccaro Alexander R. , Schroeder Gregory D.
Published: November 2022

Purpose:

The objective of this study was to compare complication, readmission, mortality, and cancellation rates between patients who had either an in-person or telemedicine preoperative cardiac clearance visit before spine surgery.

Methods:

A retrospective review was conducted on patients who underwent a spine procedure at a single tertiary academic center from February 1, 2020, to June 30, 2021. Cancellations, inpatient complications, 90-day readmissions, and inpatient and 90-day mortality rates were compared between in-person and telemedicine cardiac clearance visits. Secondary analysis included multiple logistic regression to determine independent predictors of case cancellations and complications. Alpha was set at P < 0.05.

Results:

A total of 1,331 consecutive patients were included, with 775 patients (58.2%) having an in-person cardiac clearance visit and 556 (41.8%) having telemedicine clearance. Overall, the telemedicine cohort did not have more cancellations, complications, or readmissions. Regardless of the type of clearance, patients with a history of cardiac disease had more inpatient complications (15.8% versus 6.9%, P < 0.001) and higher 90-day mortality rates (2.3% versus 0.4%, P = 0.005). Subgroup analysis of patients with a history of cardiac disease showed that patients who had telemedicine visits had more cancellations (4.6% versus 10.9%, P = 0.036) and higher 90-day mortality rates (1.4% versus 4.4%, P = 0.045). On regression analysis, telemedicine visits were not independent predictors of preoperative cancellation rates (P = 0.173) but did predict greater preoperative cancellations among patients with cardiac history (odds ratio 2.73, P = 0.036).

Discussion:

Patients with cardiac disease who undergo preoperative telemedicine visits have greater preoperative surgical cancellation rates and postoperative 90-day mortality rates. Although preoperative telemedicine visits may be appropriate for most patients, a history of cardiac disease should be a contraindication.
Hip Pain in Ballet Dancers: Evaluation and Management
Authors: Curley Andrew J. , Engler Ian D. , McClincy Michael P. , Mauro Craig S.
Published: November 2022

Hip and groin injuries are common in ballet dancers, who often begin sport-specific training at a young age. The unique demands of ballet include extreme range of motion, with an emphasis on external rotation and abduction. This creates a distinctive constellation of hip symptoms and pathology in this cohort, which may differ from other flexibility sports. When managing hip symptoms in this cohort, orthopaedic surgeons should consider the unique factors associated with ballet, including ballet-specific movements, morphologic adaptations of the hip, and the culture of the sport. Three common etiologies of hip pain in ballet dancers include femoroacetabular impingement syndrome, hip instability, and extra-articular snapping hip syndrome. First-line treatment often consists of focused physical therapy to strengthen the core and periarticular hip musculature, with surgical management reserved for patients who fail to improve with conservative measures.
A Bioinformatics Research of Active Compounds Curcuma xanthorriza in Arthritis Disease
Authors: Nevriansyah Eko , Arinda Frissherly  , Qisti Mathriu Anisa , Niesya Putri Ulfa , Handri Silvi
Published: November 2022

Curcuma xanthorriza roxb. or commonly known as ginger is a plant that grows in the tropics which is known as a million benefits plant, one of which is for the treatment of Arthritis. The main active compounds that act as anti-inflammatory which refer to arthritis are curcumin and demethoxycurcumin. The purpose of this study was to analyze the active compounds contained in ginger which play an important role in the treatment of arthritis. Bioinformatics analysis was carried out using the ChemOffice 2016 software using the molecular mechanics method. The 2-dimensional structure analysis uses the ChemDraw program, while the 3-dimensional structure analysis uses the Chem3D program. From the data optimization results using the molecular mechanics method, the following results are obtained: The total energy produced in the compounds curcumin, d-camphor, demethoxycurcumin, p-tolymethilcarbinol, starch, respectively 17.4573 kcal / mol; 29,2006 kcal / mol; 13.8948 kcal / mol; -0.6574 kcal / mol; and 29,6089 kcal / mol. Based on the research data obtained, it can be concluded that the active compounds curcumin and demethoxycurcumin are compounds that act as anti-inflammatory triggers for arthritis. It is proven that the results of the MM2 method are in accordance with the related theory.

Keyword: curcuma, anti-inflammatory, molecular mechanics, curcumin, demethoxycurcumin..

 

Keywords: Anti-inflammatory; Curcuma; Curcumin, Demethoxycurcumin; Molecular mechanics
Arduino Based Automatic Curtains and Light Dependent Resistor (LDR) Sensors
Authors: Atsiq Athaya , Husna Amelia
Published: November 2022

Today's technological developments provide very real changes in human life. There are many tools made to facilitate human work. With advances in science and technology, innovations are developed that are better. Automatic control systems in the field of science and technology lately also growing rapidly. This can be seen from the range of applications ranging from household to sophisticated equipment. Automatic curtains using Arduino-based light sensors are an idea that arose to meet the needs of home automation systems. Automatic curtains work based on the intensity of light that is captured by the light sensor and is real to be processed by Arduino and gives the task of the driving motor to carry out orders to go up or down the curtain according to the light intensity settings that have been set to the system. Simply put, when the light intensity is 271 - 1000 lux then the curtain goes up, then if the light intensity is 1001 lux the curtain will go down, and if the light intensity is 270 lux then the curtain stays down or closed.
Spoken English Deficiency among the Intermediate Pupils in Rangpur Division of Bangladesh
Authors: Rana Md Sohel
Published: November 2022

Language capability stands for a learner’s competence to use a language spontaneously and subconsciously in different situations. Skill on spoken English is extensively significant for any type of communication and correspondence. The need of spoken English is indefinable in the fields of refined education process both at home and abroad, better career opening, smart business, global communication, information and technology and better survival. It’s a deliberate process to steep capableness of English language into learners since their pre-primary tutoring to undergraduate echelon. It’s apparent in the course and syllabus of Intermediate stratum in Bangladesh that the sole emphasis has been put only on reading and writing whilst listening and speaking proficiency are remaining dark, whereas speaking skill is indispensible for transnational communication, advanced study at home and abroad, professional and business purpose, operating information and communication technology, pursuing better career etc. In this regard, lack of provocation to learn and exercise, unconstructive tutoring outfit, testing strategy excepting spoken predicated outgrowths along with marks distribution and paucity of experienced instructors in English and so on are the crucial deficits behind this problem. It’s a study targeting at assessing the spoken capability of the 12 class pupils in Rangpur Division of Bangladesh. This qualitative inquest work took place in the month of April 2022 and June 2022. The 100 informants were selected right away. Out of 100 interviewees, 50 were from urban and 50 were from rural intermediate standing institutions of 8 Districts in Rangpur Division of Bangladesh. A Spoken Test on free speech for the pupils was carried out by the author. Their speaking perfection was tested through content analysis to evoke data. The result focused that the replier made desultory errors in great number on fluency, vocabulary, information, sequence of tenses, sub-verb agreement, applicability and treatment of words, use of preposition, intonation and pronunciation. As per data compilation, it was noticed that deficits made in the process were almost on part of the rural participants. In addition, phobia in speaking English and irrelevancy were two peculiar limitations among the pupils hailing from rural background institutions.
The advantages of Implementing ICT IN Teacher Education
Authors: Rama Mr.
Published: November 2022

The rapid rise of the information and communication technologies (ICT) has grown to be one of the supreme themes investigate by educational researchers over the past two decades. This is due to the school’s capacity to provide dynamic and proactive learning and teaching environment. The use of ICT by teachers is required into their daily teaching in order to substitute modern techniques with modern tools and infrastructure to stay up with the current digital era. One of the most pressing concerns facing education today is incorporating technology into the classroom. It is past time for us to look outside the four walls of our classroom and work combined with other institutions and civilizations to rejuvenate education. The paper’s main attention is on successful integration of ICT in education, which will considerably contribute to meeting students needs for studying anywhere, at any time. ICT Integration into the learning and teaching process is a rapidly evolving topic with a wider range of definitions depending on one’s perspective. A widely held belief is that the integration of ICT process, as well as a concrete model for teachers, should be developed in order to increase student’s learning. Considering the concept that the integration method ought to improve student learning. It is necessary to give an integrated perspective in the implementation of process and the Improve some specific example for teachers. As a result, the primary goal of this research is to create a model for evaluating integration of ICT and assisting students in improving their learning.
The ZnO Nanoparticles: Synthesis, Characterization and Applications in Forensics
Authors: Dr. Aftab Ahmad Malik  , Dr. Syeda Mona Hassan  , Eisha-tur-Razia
Published: November 2022

In most fields, including health, imaging, and forensic sciences, nanotechnology is a significant andpotent tool. It is quickly expanding and has potential in a number of areas, including industries,physical science, and medical care. ZnO nanoparticles has potential in advance forensic science andaid in crime detection. Advanced art analytical techniques can be used in characterization of ZnOnanoparticles, such as High-performance liquid chromatography (HPLC), X-ray diffractionspectroscopy, and SEM. Nanotechnology forensic investigations include questioned documents, inestimating the time of death and age of blood. Moreover, nanomaterials can be used for forensicinquiry, such as quantum dots, which can be employed as luminous materials for security features inofficial and private documents. Therefore, the purpose of this study was to introduce and explain theapplication of ZnO in forensic science as well as the equipment needed to conduct nano-analysis.
"En helt annan upplevelse"
Authors: Linkis Sara Tanderup , Pennlert Julia
Published: November 2022

“An Entirely Different Experience”: The Audiobook’s Bond to its Readers
Audiobooks have in recent years become widely popular. The format accordingly impacts how many contemporary readers use and experience literature. The article examines this tendency, departing from Rita Felski’s theoretical conceptualizations of uses of literature (Felski 2008). Felski represents a new attention within literary studies toward the ways in which so-called lay readers use, experience and form attachments (Felski 2020) to literature and art. Drawing on Felski’s work in combination with Lutz Koepnick’s concept of resonant reading (2019), we study how the medial affordances of the audiobook impact uses of literature among empirical Swedish readers. In this way, we combine the theoretical perspective introduced by Felski with an approach informed by literary sociology (Svedjedal, Murray), in order to draw attention to the importance of considering the significance of media and formats in broader discussions about uses of literature. The article is based on a survey of 1400 Swedish audiobook users, which was published during the fall of 2021, in the Facebook-group Snacka om ljudböcker. We focus on a qualitative analysis of answers to the free-text question “Why do you choose to listen to audiobooks?” Our findings demonstrate that the medial affordances of the audiobook, its mobility and the mediation of literature through sound, impact both why and how readers listen to audiobooks: Respondents report among other things that audiobooks make it possible to integrate literature into everyday life, and that, consequently, it adds value to everyday activities, while the format’s mediation though sound, and especially the voice of the performer “adds a dimension” and “deepens” the reading experience. Thus, while the existing debate often associates audiobooks with distracted or passive reading and, in Felski’s terms, with detachment from the surroundings, and from the text, our findings suggest that the format also helps readers form attachments to and through literature.
Ventilation adaptée des combles en vue de l'amélioration de l'efficacité énergétique des constructions
Authors: Laidi Sadia , El Hassar Sidi Mohamed Karim , Mahrane Achour , Sellami Rabah
Published: November 2022

Ce travail a pour but d'analyser l'influence de la présence d'un comble sur la consommation énergétique d'une construction. Des essais ont donc été menés sur une construction avec comble implantée à Bou Ismail au sein de l'Unité de Développement des Equipements Solaires (UDES). L’étude du comportement thermique de cette construction a été réalisée pendant les périodes hivernale et estivale. Des températures d'air de différentes zones thermiques de la construction ont été relevées et ont été comparées aux températures d'air calculées à partir d'un modèle numérique réalisé en utilisant le logiciel TRNSYS. Un modèle numérique calibré a pu ainsi être obtenu et a été utilisé pour réaliser différentes simulations numériques en faisant varier le taux de ventilation du comble. Les résultats des simulations ont permis de montrer que la diminution des besoins de climatisation est proportionnelle à l’augmentation du taux de ventilation du comble en été, et que la diminution des besoins de chauffage est proportionnelle à la diminution du taux de ventilation du comble en hiver.
Numerical Simulation of Heating and Ventilation by Natural Convection in a Square Cavity
Authors: Mourid El Houcine , Ghanmi Mohamed Lamine , Hami Omar
Published: November 2022

Heating and ventilation in the building is essential to establish thermal comfort. The modern means invented to provide us with our heating and ventilation needs are generally expensive and represent sources of pollution. It is for this reason that there are several studies directed towards the research of renewable energies and non-polluting economic systems. The simulation of such a natural system at an almost low cost is the subject of our study in this work. In this work, a numerical study of passive heating and ventilation was made by natural convection in a room containing a heated vertical wall. In the case of heating, the system is closed and two openings are considered in the heated vertical wall allowing the re-circulation of the air in the room and therefore the heating of this latter. In the case of ventilation, the room is open to the outside through two inlet and outlet openings allowing the air circulation from the outside into the room and from the room into the outside which leads to ventilate the room. Numerical results with different mesh and Rayleigh number have been presented and their effects have been discussed.
Coordinated Control of Wind turbine and Energy storage system for Microgrid Stability
Authors: Attou Nasreddine , Zidi Sidahmed , Hadjeri Samir , Khatir Mohamed
Published: November 2022

In recent decades, the development of renewable energy has accelerated significantly due to several factors such as changing energy needs, the problem of global warming, and the depletion of fossil fuels. Wind energy is one of the renewable generation sources that can be used to achieve the EU's 2030 targets at a lower cost. However, its intermittent and stochastic nature could significantly impact the reliability and stability of the electricity system. Therefore, there is a clear necessity to mitigate power fluctuations to make the most of wind energy. To fill this gap, this paper presents a centralized control strategy based on a droop controller and a storage-integrated controller for a grid-connected variable speed wind power system (permanent magnet synchronous generator) (PMSG) to manage and stabilize the power output during intermittency periods. The main objective is to provide a stable U/f when a fluctuation event occurs. A grid failure scenario was tested to see how the control system behaves in the event of an unexpected fluctuation and its role in the stability of the power system under varying wind speed and load conditions. The effectiveness of the proposed control method was tested using MATLAB/Simulink on a small power system. The simulation results demonstrate the control system’s performance in the stability of the U/f during grid interruption.
Cubist Regression, Random Forest and Support Vector Regression for Solar Power Prediction
Authors: Chahboun Souhaila , Maaroufi Mohamed
Published: November 2022

At a time when the energy transition is inescapable and artificial intelligence is rapidly advancing in all directions, solar renewable energy output forecasting is becoming a popular concept, especially with the availability of large data sets and the critical requirement to forecast these energies, known to have a random nature. Therefore, the main goal of this study is to investigate and exploit artificial intelligence's revolutionary potential for the prediction of the electricity generated by solar photovoltaic panels. The main algorithms that will be studied in this article are cubist regression, random forest and support vector regression. This forecast is beneficial to both providers and consumers, since it will enable for more efficient use of solar renewable energy supplies, which intermittency makes their integration into the existing electrical networks a challenging task.
MPPT Fuzzy Logic Control of a Variable Speed Wind Turbine
Authors: Dahbi Abdeldjalil , Benmedjahed Miloud , Khelfaoui Abderrahman , Kadi Sara , Benlahbib Boualam , Guentri Houcine , Aoun Nouar , Harrag Abdelghani , Hamouda Messaoud , Bouraiou Ahmed , Slimani Abdeldjalil , Neçaibia Ammar , Chogueur Djilali , Tidjar Boudjema , Oudran Abdellatif , Bouchouicha Kada , Mouhadjer Samir , Touahri Tahar , Kadri Ahmed Yassine
Published: November 2022

This work is focused on the control of a wind turbine system based on (PMSG). In order to enhance the efficiency of the wind turbine system, the maximum power point tracking (MPPT) control is applied to exploit the maximum power from the wind. The Fuzzy Logic controller (FLC) has been proposed and developed for the speed control. The simulation results show good performances of this control.
A high degree of direct torque control applied to a grid-connected wind energy system based on a DFIG
Authors: Djoudi Oualid , Lalouni Belaid Sofia , Tamalouzt Salah
Published: November 2022

This paper presents the performances improvement of a doubly fed induction generator (DFIG) driven by a wind turbine (WT) using direct torque control (DTC). However, the major drawbacks related to DTC are high torque/flux ripples that produce mechanical vibration and disagreeable noise. The use of multilevel inverters seems to be an interesting solution. A three-level voltage source (inverter) converter (3LVSI) connected to the rotor side of the DFIG is considered in this paper. The high freedom degree of the voltage vectors selection in the 3LVSI allows a control with minimal torque and flux ripples. In addition, a fuzzy logic approach is introduced, to ensure an intelligent extraction of the energy sweeping the WT blades. A variable adjustment step enables an optimal extraction in a minimum tracking time with significant reduction of oscillations in the steady state. Simulation results obtained using MATLAB/SIMULINK demonstrate the effectiveness of the 3LVSI-DTC control based on Fuzzy MPPT in the wind energy conversion system (WECS).
Assessment Microbiological and Physicochemical Quality of Figs Dried in Adrar Region, Algeria
Authors: Loumani Akil , Larbi Ahmed Amine , Mediani Ahmed , Braham Chaouch Wafa , Foullanine Meriama , Tigani Cherif , Djaber Abdelkrim , Belkacem Zahra
Published: November 2022

The figs are considered one of the fruits of paradise due to their great nutritional value that brings health back to the citizen, including protection from malnutrition. However, the consumption of the inhabitants of Adrar state for this fruit is very little and that is the lack of abundance in the market during the season, in addition to the rapid spoilage of this delicate fruit in case It was transported from the north due to the difficult delivery conditions, including the period and method of transportation to the province. Therefore, the solar drying team studied the preservation of this material through the solar drying method in order to preserve and store it for consumption throughout the year. In this study, the fresh figs were screened for the drying process using indirect solar, after that, the microbiological and physicochemical properties was tested in order to evaluate the nutritive value and hygienic quality of dried figs. The results revealed the presence of mesophilic aerobic total bacteria and coliform total, as well as the absence of Salmonella Typhi, Staphylococcus aureus, Clostridium perfringens, and certain yeast colonies. The pH value, activity water, dray matter, and ash assay findings were (0.41), (7.5%), (5.71%), and (5.71%), respectively, which do not impact the final quality of the dried goods and are satisfactory to the standards required by Algerian commercial legislation.
Investigation, Analysis and Optimization of PEMFC Channel Cross-Section Shape
Authors: Mohammedi Abdallah , Sahli Youcef , Moungar Houcine , Benhammou Mohammed , Ben Moussa Hocine
Published: November 2022

In this study, a three-dimensional (CFD) model is employed to simulate and optimize the CCS (Channel Cross-Section) shape of the single straight channel PEMFC. Four CCS shapes, namely trapeze, inverted trapeze, half of ellipse and inverted half of ellipse, are investigated using ANSYS-FLUENT software and compared to the rectangular and triangular CCS shapes. The results obtained from the simulation are compared to the experimental results of the literature. A good agreement is observed between the numerical and experimental results. From the obtained results, it appears that the best delivered power density is reported by the trapeze CCS configuration, whereas, the worst delivered power density is obtained by the inverted half of ellipse CCS configuration. The highest pressure-drop and pumping power are obtained with the triangular CCS configuration and the smallest are resulted by the rectangular CCS configuration. Finally, the highest net power output is reported by the trapeze channel cross-section configuration, while, the lowest one is yielded by the inverted half of ellipse CCS configuration.
Investigation of monocrystalline silicon surface texturization by image processing program
Authors: Trad khodja Abdellah , Elamrani Abdelkader , Kezzoula Faouzi , Nasraoui Chahinez , Friha Seif-Eddine
Published: November 2022

One of the main issues in the photovoltaic industry of silicon solar cells is the optical losses via reflection. To overcome this issue, texturization (chemical etching) remains the most commonly used method to produce a random pyramid structure to reduce reflection and thus increase photocurrent generation. Because of the anisotropic etching property of alkaline solution, square-based upright pyramids are formed, i.e., the difference in etching rates between (100) and (111) planes. In this paper, the following etching solutions were studied: 4/10, 6/6, and 10/4 (KOH weight percentage/IPA volume percentage).The optical, morphological, and electric characterizations using UV-Vis spectroscopy, electron scanning microscopy (SEM), and quasi-steady-state photoconductance (QSSPC) device are performed. Also, the standard weighted reflectance (SWR) was calculated. The pyramid size distribution generated using KOH-IPA solutions was investigated using an image processing program (ImageJ) via SEM images. The calculation of the height of the pyramids reveals that the typical pyramid size ranges from 3 to 9 m, with large pyramids of small proportions. Furthermore, when the pyramids are distributed in a mixture of tiny and medium pyramids in precise proportions, the reflectivity is at its lowest, and as the number of large pyramids rises, the reflectivity increases.
Numerical analysis termal fluid in a heat exchanger with baffles inclination
Authors: Youcef Ahmed , Saim Rachid , Kourti Mohammed Chokri , Benhamou Mohammed
Published: November 2022

A research on Thermo-hydraulic performance carried out on three types of heat exchanger with different baffles inclination 15°, 25°, 45° by the computer code Fluent, the model achievable is turbulence . The results show big recirculation zones and lower temperature peaks on the outlet for the decreased angles, the average heat transfer coefficient decreased by 1 %, pressure loss decreased by 1.2%, amount of heat exchanged between the tubes and the water increases by 1.2%.
Perturb and observe maximum power point tracking method for photovoltaic systems using duty-cycle modulation
Authors: Louossi Theodore , Djongyang Noël , Sosso Mayi Olivier Thierry , Nanfak Arnaud
Published: November 2022

This paper presents the implementation of perturb and observe maximum power point tracking algorithm with Duty Cycle Modulation instead of pulse width modulator for photovoltaic power generators. Like all the different methods used for tracking the maximum power point of photovoltaic system, perturb and observe method use a Pulse Width Modulation to control the DC-DC converter. Here, the Duty Cycle Modulation is used in the place of Pulse Width Modulation. A detailed analysis of the approach is proposed and simulations are performed using MATLAB/Simulink software. The results show the performance and speed at which this control reaches the maximum power point. The response times is very low and is between 0.0125s and 0.05s depending on the climatic variations. So, Duty Cycle Modulation can be used as an alternative to Pulse Width Modulation for the search of the maximum power point.
Direct Torque Control of Two Series Connected Six-Three phases Motor Fed by Single Six Phases VSI Based on Optimum Vectors Selection
Authors: Yahia Chedni , Djamel Boudana , Lazhari Nezli
Published: November 2022

In this paper, a direct torque control (DTC) is developed for a two series connected six-phase & three-phase motor drive (IMs) with sinusoidal distributed windings and fed by single six-phase voltage source inverter (VSI). Direct torque control also considered as a variable structure control strategy with simplicity, fast response and tolerance to motor parameter variations; it provides direct control of stator flux and torque by optimally selecting the inverter states in each sampling period. In case of multi-phase system drive, the increased number of voltages vectors offers greater flexibility in optimizing the selection of the inverter states. The technique elaborated in this work based direct torque control allows independently control of the system fed by single inverter. The effectiveness and capability of the proposed method are shown by computer simulation.
Numerical Optimization of a Tandem Solar Cell based on InxGa1-xN
Authors: Pelap François Beceau , Konga Tagne Eric , Kapim Kenfack Abraham Dimitri
Published: November 2022

This article examines the best fraction of indium (x) and critical depth (H) of a single junction tandem photovoltaic (PV) cell (InxGa1-xN) in the vein to optimize its electrical efficiency. For better investigation, the optical and electronics parameters of a solar cell are determined as a function of the indium fraction and depth of the solar cell, leading to the resolution of the continuity equation and the establishment of the electrical characteristics (short circuit photocurrent, open-circuit photovoltage, maximum electric power). The outlet of our numerical investigations conducted under standard test conditions in the visible spectrum bandwidth of the irradiation, we found that the best indium fraction and the solar cell depth at the optimum electric power point are x=0.6 and H=1m (In0.6Ga0.4N) respectively. Furthermore under normalized irradiation condition (0.1 W/cm2, T=25oC), we found a maximum electric power and efficiency of about 28.53 mW/cm2 and 28.53% respectively.
Revue sur les nanofluides et leurs applications dans le domaine de l'énergie solaire
Authors: Bekhti Mohammed , Saim Rachid
Published: November 2022

In this article, an analysis of the integration of nanofluids and their applications in the field of solar energy has been discussed. Practically, several factors affect the physical properties of nanofluids. The use of nanofluids as an absorbent fluid is an effective approach to improve heat transfer in solar-powered devices. The main objective of this review is to examine and categorize all existing formulas and correlations on the physical properties and physical models of nanofluids, including thermal conductivity, viscosity, density, and specific heat, and to summarize the research carried out in recent years on the applications of nanofluids in solar energy systems. This article also identifies future research opportunities in the field of solar energy
Simulation and Analysis of Losses by Degradation in Photovoltaic Energy Production System
Authors: Zarede Toufik
Published: November 2022

Currently several technologies are being developed to produce electricity from renewable sources, and the degrees of maturity, performance and lifetime are very different from one technology to another. This work presents a study by a simulation and analysis for clarity the effect of aging of a photovoltaic module associated with an energy production system of renewable origin installed in a desert environment. The PV array has a nominal power of 9,2KWp, and the photovoltaic module used in this study is heterojunction with intrinsic thin layer technology of 230WP. During this work, we obtained the system production is 17131 KWh/year, the producible is 1862 KWh/KWp/year, and the normalized production is 5,10 KWh/KWp/day, with the losses of the system is 0,16KWh/KWp/day. The performance ratio of our simulated system is about 0,822, and the collection loss of the photovoltaic field is LC = 0,94KWh/KWP/day, with loss system is LS = 0,16 KWh/KWP/day, and the aging rate of photovoltaic module estimated by simulation around the 14% for 25 years of electrical production in a desert environment.
Improvement of the energy production of a photovoltaic-wind hybrid system using NF-PSO MPPT
Authors: Abena Malobé Paul , Djondiné Philippe , Ntsama Eloundou Pascal , Abena Ndongo Hervé
Published: November 2022

This manuscript gives a contribution to the optimization of a hybrid Photovoltaic-Wind Turbine system with a storage system. In order to capture the maximum power that can be produced by each source, while maintaining the rotor speed of the wind turbine at its maximum values according to wind variations, the Neuro-Fuzzy-Particle Swarm Optimization (NF-PSO) controller is proposed. The Neuro-Fuzzy method is used here because it allows an automatic generation of fuzzy rules, and the Particle Swarm Optimization to find an optimal gain allowing to readjust the dynamics of the fuzzy rules by reducing the power losses (oscillations). For the proper functioning of such a system, we have developed a fuzzy supervisor in order to have an optimal control of the system according to the variations of the requested load and the produced power by considering the storage system and the load shedding. The simulation results of the system confirmed the better performance of this method in terms of speed with a response time of 0.2s on the wind side and 0.025s on the side photovoltaic, of efficiency with 99.87% on the photovoltaic side and 99.6% on the wind side, and above all in term of oscillation reduction with practically a negligible oscillation rate compared to the NF and the Cuckoo algorithm.
Cost optimization of a wind-solar-diesel system with battery storage
Authors: Saheb-Koussa Djohra , Aries Nawel
Published: November 2022

This work presents the optimization of a wind-solar-diesel system with battery storage for a continuous and reliable production of electrical energy. In this context, detailed mathematical modeling of the present system and its operation algorithm has been presented. The objective function of the system is to minimize its cost of energy (CoE) which estimates the average lifetime cost of power production per kWh. The cost elements comprising the CoE include investment costs, fuel costs, and operation and maintenance costs. The optimization is performed in the HOMER software in addition to three metaheuristic optimization techniques namely the Cuckoo Search algorithm (CS), the BAT algorithm (BA) and the Firefly algorithm (FA). The simulations conducted in this paper are based on meteorological data collected from an installation in Bouzareah. Simulation results show the excellent properties and superiority of the CS optimization method compared to HOMER, BA and FA algorithms and demonstrate the feasibility of the proposed hybrid PV-wind-diesel-battery system in Bouzareah.
Geochemical studies of gases from oil and gas fields in the southern part of the caspian basin and their correlation with the results of oil geochemistry
Authors:   Atyrau branch of KMG Engineering, Atyrau city, Kazakhstan, Seitkhaziyev Y. Sh.
Published: November 2022

This article presents the results and interpretation of the compositional and isotopic analysis of carbon in 14 gas samples derived from oil and gas fields and structures (Liman, East Makat, North Kotyrtas, Zholamanov, S. Nurzhanov and West Prorva) of the southern part of Pre-Caspian basin. According to the results of this study, all gases have a thermogenic source and their organic matters were deposited in the marine environment, which is also consistent with the results of biomarker analysis of oils from these studied fields. A sharp enrichment of propane with heavy carbon isotope in gas №55 of East Makat field suggests its biodegradation, which is also confirmed by the results of gas chromatographic analysis of oil from this well. A star diagram of gases was plotted based on normalized values of carbon isotopic composition of C1-C5, according to the results of which the studied samples can be divided into 5 genetically different groups. The identified groups based on results of this gas analysis are also consistent with the results of «fingerprinting» of oil from these fields. Keywords: gas composition; gas isotopic composition; Rayleigh fractionation; Bernard diagram; Clayton diagram; Laurent diagram; Chung diagram; enrichment in heavy isotope.
Korelasi antara Ketersediaan Informasi Medis dengan Ketepatan Kode Diagnosis Bronchitis pada Dokumen Rekam Medis Rawat Inap di Rumah Sakit Umum Daerah Kabupaten Karanganyar Tahun 2019
Authors: Astuti Mega Dwi , Pratama Bangkit Ary
Published: November 2022

One of the factors that affect the accuracy of the diagnosis code was the availability of medical information in the form of filling out the diagnosis. The purpose of the study was to determine the correlation between the availability of medical information and the accuracy of the bronchitis diagnosis code on inpatient medical record documents at the Karanganyar Regency General Hospital in 2019. This type of research was descriptive with a retrospective approach. The method used was observation. The research population was 482 medical record documents and 83 medical record documents were taken as samples. The sampling technique used was simple random sampling. Due to the Covid-19 pandemic, the sample collection became 10 medical record documents. The results of the study were based on a sample of 10 medical record documents with bronchitis cases, there were 3 documents available (30%) of medical information, which was smaller than 7 documents (70%). The accuracy of the code is 2 documents (20%) smaller than the incorrect code, which was 8 documents (80%). From the results of the Chi-Square Test statistical test, the value of (0.016) <0.05, which meant that H0 was rejected and Ha was accepted. The conclusion of this study was that there was a correlation between the availability of medical information and the accuracy of the bronchitis diagnosis code on the medical record document of inpatients at the Karanganyar Regency General Hospital in 2019.
Pengaruh Variasi Konsentrasi Katalis Asam Sulfat Pekat Terhadap Hasil Derajat Esterifikasi Metil Laurat
Authors: Susanti Maria Mita , Liana Nurhafni Audi
Published: November 2022

Fatty acid esters are derived from vegetable oils and animal fats which can be used for chemical industries, such as the cosmetics industry, pharmaceutical ingredients, and the manufacture of fat alcohol, one of which is methyl laurate. This study aims to determine the effect of variations in concentrated sulfuric acid catalysts on the results of the degree of esterification can provide significant results in order to obtain an optimal degree of esterification. This research is an experiment which is to determine the effect of the addition of variations in concentrations of concentrated sulfuric acid catalyst to the results of the degree of esterification of methyl laurate. The research design used was a completely randomized design (CRD) of one factor, namely the effect of adding concentrated sulfuric acid catalyst. The variables observed were variations in the addition of concentrated sulfuric acid catalysts with a concentration of 2%, 3%, 4%, 5%, 6% to the results of the degree of esterification reacted for 3.5 hours. Analysis of statistical data obtained was tested using the Kruskal Wallis test. The results showed that the more concentrated concentrated sulfuric acid catalyst was added, the higher the degree of esterification. The results of the degree of esterification obtained are 99,25%. Statistical data analysis obtained sig value 0.009 (p<0,05) which means that the variation in concentrated concentrations of concentrated sulfuric acid affects the results of the degree of esterification of methyl laurate.
Pemeriksaan Angka Kuman, Kapang (Khamir) Dan Identifikasi Bakteri Patogen Pada Jamu Beras Kencur di Pasar Tradisional Kota Surakarta
Authors: Monita Krisanti , Sari Ajeng Novita , Nurhayati - Politeknik Santo Paulus Surakarta Nurhayati
Published: November 2022

Beras-Kencur Herb is a traditional drink that was made by non-standard ingredient and through simple processing. These are believed could be a contributing factor of bacterial and fungal contamination. The National Supervisory Agency of Drug and Food of the Republic of Indonesia (BPOM RI) regulation number 12 year 2014 regarding quality requirement for traditional medicine stated that traditional medicine has to be free from E.coli, Salmonella sp., Shigella sp. and the Total Yeast and Mold Count (TYMC) <103 coloni/g. This study aimed to investigate the contamination of coliform bacteria and yeast/mold on Beras-Kencur Herb that was sold in the traditional market in Surakarta City. This study was a descriptive comparison with 14 Beras-Kencur Herb samples. This study found that Beras-Kencur Herb contained 100% of coliform bacteria, 50% of E.coli, 28.6% of Salmonella sp., 85.7% of Shigella sp. with the lowest TYMC was 0 coloni/ml and the highest was 7,5 x 101 coloni/ml. Meanwhile, the funguses were found are Aspergillus sp., Penicillium sp., Mucor sp. and Candida sp. As conclusion, the samples of Beras-Kencur Herb that were sold in the traditional market in Surakarta City have been contaminated by Coliform bacteria, yet the TYMC ratio was met the requirement set by BPOM RI.
Antioxidant Activity of Pegagan Leaf Fraction (Centella asiatica (L) Urb.) by FRAP Method
Authors: Puspita Aristika Linda , Susilowati Susilowati
Published: November 2022

Centella asiatica or known as Pegagan is an Indonesian plant and it's contain some secondary metabolite compounds including flavonoids, polyphenols, saponins, triterpenoids and steroids. These compounds are natural antioxidants that are useful for health. The purpose of this study was to determine the antioxidant power of the fraction from pegagan leaf extract. The study began with the extraction of pegagan leaves using 70% ethanol. Furthermore, the ethanol extract was extracted with n-hexane, ethyl acetate, and water sequentially to produce three fractions. Each fraction was tested for their antioxidant power using FRAP method. The antioxidant power was seen from the FRAP value expressed in mg ascorbic acid equivalent/gram sample (mgAAE/g sample). The antioxidant power of each fraction showed that the n-hexane fraction was 0.06210mgAAE/g, the ethyl acetate fraction was 0.09349mgAAE/g, and the water fraction was 0.08742mgAAE/g. The ethyl acetate fraction showed the highest antioxidant power although from the one way ANOVA test did not show a significant difference than n-hexane and water fractions.