bluuebunny/crossref_metadata_2025 huggingface dataset:
PERGANTIAN KANTOR AKUNTAN PUBLIK dan FAKTOR-FAKTOR YANG MEMPENGARUHINYA
Authors: Meliala Hernyke Alviani Sembiring , Sulistyawati Ardiani Ika
Published: December 2020

Penelitian ini bertujuan untuk menemukan bukti empiris mengenai faktor-faktor yang mempengaruhi pergantian kantor akuntan publk (KAP)pada perusahaan yang terdaftar di Bursa Efek Indonesia (BEI). Variabel yang digunakan dalam penelitian ini adalah pergantian KAP, pergantian manajemen, financial distress, opini auditor, ukuran KAP, danukuranklien. Populasi dalam penelitian ini merupakan seluruh perusahaan yang terdaftar di BEI tahun 2008-2012. Pemilihan sampel menggunakan metode purposive sampling. Sampel penelitian ini terdiri dari 57 perusahaan yang terdaftar di BEI. Total sampel dalam penelitian ini adalah 285 perusahaan,Hipotesis dalam penelitian ini diuji menggunakan regresi logistik. Hasil penelitian menunjukkan bahwa pergantian manajemen berpengaruh signifikan terhadap pergantian KAP. Sedangkan variabel financial distress, opini auditor, ukuran KAP dan ukuran klien tidak berpengaruh signifikan terhadap pergantian KAP.Kata Kunci :pergantian kantor akuntan publik, pergantian manajemen, financial distress, opini auditor, ukuran KAP, ukuran klien.
PERKEMBANGAN INDUSTRI PERBANKAN SYARIAH DI INDONESIA : ANALISIS PELUANG DAN TANTANGAN
Authors: Werdi Apriyanti Hani
Published: December 2020

ABSTRAK Industri Perbankan Syariah memiliki peran yang strategis dalam pembangunan ekonomi rakyat, berkontribusidalam melakukan transformasi perekonomian pada aktivitas ekonomi produktif, bernilai tambah dan inklusif.Akan tetapi di era financial  digital  dan  tingginya  persaingan  industri  jasa  keuangan  seperti  sekarangini,   perbankan   syariah   menghadapi   berbagai   tantangan,   terutama   berkaitan   dengan   rendahnyaTeknologi Informasi dan Komunikasi (ICT) dan keterbatasan modal. Oleh karena itu industri perbankan syariah harus  memanfaatkan  berbagai  peluang  ,yaitu  dengan  menyediakan  inovasi  produk  berbasis Teknologi Informasi  dan  Komunikasi  (ICT)  untuk  menyediakan  beragam  pilihan  dan     memperluas jangkauan pada masyarakat. Akan tetapi, sampai saat ini ivovasi produk perbankan syariah tersebut masih sangat terbatas.Selain itu, hal lain yang tidak kalah penting untuk mendukung perkembangan Perbankan Syariah di Indonesiaadalah dengan memanfaatkan peluang pertumbuhan ekonomi, dan meningkatkan ketersediaan dana banksyariah. Dengan memanfaatkan peluang tersebut, industri Perbankan syariah di Indonesia dapat berkembangdan memiliki dayasaing.
ANALISIS PENGARUH GOOD CORPORATE GOVERNANCE TERHADAP KINERJA PERUSAHAAN PERBANKAN DI INDONESIA
Authors: Listyawati Ika , Kristiana Ida
Published: December 2020

Corporate governance is still a major problem during financial periods such as Indonesia. Especially, financial institutions  have  carried  out  reforms  to  improve  goals  and stakeholders. The purposeof this study is to measure corporate governance and in a banking environment that is specific to corporategovernance.The independent variables used in this study are ownership structures consisting of controllingshareholder ownership, foreign ownership, government ownership; the size of the board of  directors;  the sizeof the board of commissioners; independent commissioner; CAR. The sample of this study is a general bankingcompany located in Indonesia which is listed on the Indonesia Stock Exchange (BEI) for the period 2010-2014.This research data is derived  from  the  annual  report  of  the  bank  (annual  report)  for  the  period  20102014 whichis obtained fromthewebsiteof eachof the banks, theIndonesianBankingDirectory,Indonesian Capital Market Directory(ICMD).Theanalyticalmethodusedismultiple linear regression in accordance with the research objectives that analyzethe effect of independent variables on the dependentvariable. Thepurposivesamplingmethodisusedtodeterminethesampleofchoice.Fro this method,get26 samples of commercial banks.The results of the analysis found that  Controlling  Shareholder  Ownership  (OWN)  andGovernment Ownership (GOV) showed a negative relationship not significant to banking performance.However, for Foreign Ownership (FOR), Board of Directors Size  (BOD), Board  of  Commissioners  Size(BOC), Proportion of Independent Commissioners (INDEP) shows a  positive  and  significant  relationship.Then for the variable Capital Adequacy Ratio (CAR) there is a significant negative relationship.
KETERLIBATAN TUTOR DALAM PENINGKATAN ANGKA PARTISIPASI KASAR (APK) MAHASISWA (STUDI DI UNIVERSITAS TERBUKA UPBJJ SEMARANG)
Authors: Pramudibyanto Hascaryo , Weningsih Sri
Published: December 2020

APK pendidikan tinggi masih lebih rendah jika dibandingkan pendidikan usia dini, SD, SMP, maupunSMA meskipun trend menunjukkan peningkatan. Fenomena ini menjadi penting mengingat pendidikan yangtinggi adalah salah satu faktor terpenting untuk menghasilkan individu yang mamiliki produktivitas tinggi.Peningkatan APK pendidikan tinggi khususnya pada mahasiswa UT tidak dapat dilepaskan dari peran tutor.Studi ini, dengan menggunakan pendekatan deskriptif kualitatif bertujuan untuk menguraikan keterlibatantutor dalam meningkatkan APK mahasiswa UT. Hasilnya menunjukkan bahwa tutor memiliki peran dalammeningkatkan APK mahasiswa UT yang ditunjukkan dari kesediaan tutor untuk dengan senang hati terlibatdalam peningkatan APK mahasiswa UT, kesediaan tutor untuk terlibat dalam pencapaian mahasiswa baru,kesediaan tutor untuk melakukan sosialisasi, serta reward atas ketercapaian peningkatan APK mahasiswa UT.
TO THE QUESTION OF THE COURSE OF PULMONARY TUBERCULOSIS WITH DISEASES OF THE CARDIOVASCULAR SYSTEM
Authors:   Samarkand State Medical Institute of the Republic of Uzbekistan, Saidova Mamura
Published: December 2020

With pulmonary tuberculosis, even in the early stages of the development of a specific process, changes in the cardiovascular system are noted. The high sensitivity of the vascular system to tuberculous intoxication has long been established.With the combination of active tuberculosis process with cardiovascular pathologies, great difficulties arise in connection with the need for a comprehensive antibacterial therapy for tuberculosis and the simultaneous treatment of concomitant diseases, including vascular pathology. The purpose of this article is to study the features of the course of cardiovascular lesions in patients with pulmonary tuberculosis during various periods of the disease. Of particular interest is the study of changes in the right and left parts of the heart in those cases when signs of hypertension are not detected on the basis of clinical, radiological and electro cardiographic studies
IMBALANCE OF THE NEURAL AND ENDOCRINE SYSTEMS IN RHEUMATOID ARTHRITIS
Authors:   Samarkand State Medical Institute of the Republic of Uzbekistan, Toirov Erkin , Akhmedov Ibrat , Sultonov Ilkhom
Published: December 2020

With rheumatoid arthritis (RA), along with the main manifestations, there are a variety of neurological, neurotic and endocrine symptoms caused by immune effects. In addition, the chronic course of RA and the disability of patients leads to a violation of their usual way of life, a change in the circle of vital interests and the formation of neurotic disorders. Neurotic disorders are accompanied by a violation of the plasticity of the nervous system -its ability to regulate all structural and functional organizations and adaptation processes, which in turn leads to profound changes in immunological homeostasis, hormonal balance and all types of metabolism
FUNDAMENTALS OF RADIATION DIAGNOSTICS OF THE HEART AND LARGE VESSELS IN CHILDREN (REVIEW)
Authors:   Samarkand State Medical Institute of the Republic of Uzbekistan, Akhmedov Yakub
Published: December 2020

Radiation diagnostics of the heart and large vessels in children are part of the general clinical examination of the patient.Its purpose is to establish a diagnosis of the disease, as well as determine the nature of hemodynamic disorders. The examination plan (algorithm) of children should be drawn up in such a way as to avoid excessive exposure. X-ray endovascular interventions include many other manipulations: scabbard, scabbard closure of uninhabited arterial duct Batalov and defect in the septum of the heart, scabbard embolectomy, scabbard removal of foreign bodies from the heart. This technique is used in chemotherapy to dissolve blood clots in the lumen of the vasodilatation thrombolysis
MODERN VISUALIZATION METHODS IN DIAGNOSTICS OF MORPHO-FUNCTIONAL CHANGES OF THE MYOCARDIUM AND CORONARY ARTERIES (REVIEW)
Authors:   Acquired Heart Diseases of the Republican Specialized Center for Surgery named after Academician V. Vakhidov., Turaev Feruz , Maksudov Muzaffar
Published: December 2020

The most important task of health care is early detection and diagnosis, management, improvement of the system of cardiological and cardiac surgery care, increasing its efficiency and availability, especially in patients with suspected coronary artery disease.Despite the constant improvement of technologies for the diagnosis and treatment of CVD, coronary heart disease (CHD) remains the main cause of premature death and disability worldwide
DIFFERENTIAL DIAGNOSTICS OF NON-SPECIFIC INTERSTITIAL PNEUMONIA
Authors:   Samarkand State Medical Institute of the Republic of Uzbekistan, Makhmatmuradova Nargiza , Ibadova Olga , Zikriyaeva Parvina
Published: December 2020

A retrospective analysis of case histories of 82 patients with nonspecific interstitial pneumonia, 24 patients with idiopathic pulmonary fibrosis, 8 with exogenous allergic alveolitis, 12 with systemic scleroderma and 6 with drug pneumonia was carried out in hospital treatment in the pulmonology department of the Samarkand city medical hospital in 2010-2019 years. It has been established that in the differential diagnosis of nonspecific interstitial pneumonia and other lung diseases, particular attention should be paid to the anamnesis, clinical presentation and CT signs
NETWORK FUNCTION VIRTUALIZATION FOR UNDERWATER ACOUSTIC WIRELESS COMMUNICATION USING STOCHASTIC NETWORK CALCULUS
Authors: Ponraj T. C.Subash , Sukumaran Rajeev
Published: December 2020

Wireless communication in marine environments is hindered by the unique properties of seawater and the rugged ocean floor. In contrast to land-based communication, underwater conditions are distinct due to the specific characteristics of seawater. This research explores the potential of Network Function Virtualization (NFV) to enhance the monitoring of seaweed farms and underwater properties. As seaweed production is vital for the development of nutritional products, biochemical compounds, and pharmacological research, optimizing its monitoring is crucial. The goal of this study is to leverage NFV to support various aquatic activities. To achieve this, a chain of Virtual Network Functions (VNFs) is proposed to manage service flows, capitalizing on the advancements in NFV. The research employs both simulation and analytical Stochastic Network Calculus (SNC) models to evaluate key performance indicators, including delay bounds, throughput, packet delivery ratio, and energy utilization. Notably, the SNC-based NFV model outperforms simulation results, demonstrating superior performance and potential for improved packet delivery and throughput.
Macro-Scale Numerical Modeling of Unreinforced Brick Masonry Squat Pier Under In-Plane Shear
Authors: Rafiq Adil
Published: December 2020

Numerical modeling of brick masonry behaviour under different performance conditions has always remained a challenging task. Several modeling strategies have been developed for masonry, in general, through the course of time that have been simplified to speed up modeling and analysis duration. This ranges from a simplified strut model to a highly discontinuous micro-scale nonlinear model. With the current advent of high-speed computing and modeling tools, more realistic numerical modeling of masonry is now possible. In this paper, the strategy adopted is based on macro-scale modeling, where isotropic material properties are considered for the homogenous continuum. ABAQUS is used as a state-of-the-art finite element-based analysis and modeling tool. The Concrete Damage Plasticity (CDP) model is used for simulating inelastic material behaviour of brick and mortar, which is available in the ABAQUS library. This material model can be used in both implicit and explicit schemes of integration but the explicit procedure is highly preferred as it overcomes the convergence issues. Various parameters required for CDP modeling of brick and mortar are adapted from literature. The model is assembled in two parts, first part is modeled for masonry with both elastic and plastic properties, while the other part simulates a rigid beam at the top of the masonry part to create a uniform in-plane shear loading effect. The masonry part has been fixed at the bottom with free vertical ends, while horizontal in-plane displacement was applied to the top rigid beam. The load-displacement curves were generated from these models for monotonic push, to compare them with the envelopes of experimental results, loaded similarly. Since brick masonry is a highly disjointed material, it is a complicated procedure to develop an exact model and predict its exact behaviour. However, the overall representative load-displacement curve developed numerically was in good agreement with the ones produced experimentally.
ERROR ANALYSIS OF CLOSED NEWTON-COTES CUBATURE SCHEMES FOR DOUBLE INTEGRALS
Authors: Malik Kamran
Published: December 2020

Numerical integration is one of the fundamental tools of numerical analysis to cope with the complex integrals which cannot be evaluated analytically, and for the cases where the integrand is not mathematically known in closed form. The quadrature rules are used for approximating single integrals, whereas cubature rules are used to evaluate integrals in higher dimensions. In this work, we consider the closed Newton-Cotes cubature schemes for double integrals and discuss consequent error analysis of these schemes in terms of the degree of precision, local error terms for the basic form approximations, composite forms and the global error terms. Besides, the computational cost of the implementation of these schemes is also presented. The theorems proved in this work area pioneering investigation on error analysis of such schemes in the literature.
A NEW AND RELIABLE STATISTICAL APPROACH WITH EFFECTIVE PROFILING OF HARDNESS PRESERVING SAMPLES IN TIG-WELDING, THERMAL TREATMENT AND AGE-HARDENING OF ALUMINUM ALLOY 6061
Authors: Aftab Umair
Published: December 2020

Light metals and alloys are highly fascinated by aircraft industries due to their good strength-to-weight ratio, which is the prime requirement for aviation’s designers. Assembling of aircrafts components is often carried out using tungsten inert gas (TIG) welding, which is more acceptable for heat treatable aluminum alloys. We focus on the viable use of TIG welded assemblies of 6061 aluminum alloys to homogenize its hardness properties by heat treatment. Investigation proceeds by perceiving the effect of different precipitation hardening conditions on Aluminum alloy through their micro and macro-structural behavior and microhardness analysis. The statistical examination was conducted to evaluate the integrity of heat treated samples. A new and efficient measure – the coefficient of reliability – is introduced to outline the best hardness preserving samples. The statistical analysis shows the effectiveness of the coefficient of reliability to outline the best samples. The experimental results show that the samples aged at 175oC for 12 hours preserve the hardness profile of the welded alloy. The result is also verified from the mean hardness, coefficient of reliability and standard deviation values and in agreement with literature.
Self-healing performance of smart coatings modified with different corrosion inhibitors
Authors: Habib Sehrish , Fayyed Eman , Nawaz Muddasir , Khan Adnan , Shakoor Abdul , Karahman Ramazan , Abdullah Aboubakr
Published: December 2020

Corrosion results in considerable materials and equipment failure. According to one survey, about 1/4 to 1/3 of the total interruption in industries is due to detrimental effects of corrosion. It is, therefore, important to prevent corrosion to guarantee the reliability of the assets. The present work is aimed to explore the purpose of CeO2 as a carrier for corrosion inhibitors and its capability to release inhibitors, to achieve decent corrosion protection efficiency in epoxy-based polymeric nanocomposite coatings. Amine-based corrosion inhibitors (N-methylthiourea NMTU and Dodecylamine DDA) were used for CeO2 nano container modification, and corrosion inhibition efficiency has been explored utilizing electrochemical impedance spectroscopy (EIS) in 3.5 wt% NaCl solution. Loading of inhibitor into nanocontainer has been confirmed through Fouriertransform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET). It was observed that 25% and 29.75% w/w of NMTU and DDA were loaded into nanocontainers, confirmed through Thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) analysis endorsed the formation of a protective layer on a scratch area to protect steel from the external environment. This protective layer played a very important role in protecting steel from progressing corrosion on the defect site from the aggressiveness of the solution. EIS measurements revealed the decent corrosion inhibition efficiency of these inhibitors in order of DDA>NMTU. As a result, they are a favorable solution for longer endurance of coated piping steel and decreased operation expense contributing to economic savings, materials reliability and safety.
Cellulose microfibers (CMFs) reinforced smart self-healing polymeric composite coatings for corrosion protection of steel
Authors: Nawaz Muddasir , Habib Sehrish , Khan Adnan , Shakoor Abdul , Kahraman Ramazan
Published: December 2020

The use of organic coating for the metals has been widely being used to protect the surface against corrosion. Polymeric coating incorporated with Nanocontainers loaded with inhibitor and self-healing provides better corrosion resistance. Cellulose microfibers (CMFs) used as smart carriers were synthesized and loaded with dodecylamine (DOC)-inhibitor and polyethyleneimine (PEI)-both inhibitor and self-healing agents. Smart polymeric coatings were developed by mixing CMF/DOC and CMFs/PEI into the epoxy matrix. Reference coatings (that has only CMFs) were also prepared for a compersion. Scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal gravitational analysis (TGA) were used to confirm the loading of DOC and PEI onto the CMFs. UV-vis analysis indicates that the self-release of inhibitor from CMFs is sensitive to pH of the solution and the immersion time. Recovery of controlled surface damage confirms the decent self-healing ability of the prepared smart coatings is due to the efficient release of inhibitor (DOC) and self-healing agent (PEI) in the damaged area leading to the formation of a protective film. Electrochemical impedance spectroscopy (EIS) results demonstrate that corrosion resistance of the smart coating increases with an increase in immersion time which is due to the progressive release of inhibitors from CMFs in response to the pH change. Therefore, smart coatings demonstrate superior properties as compared to the reference coatings. The study reveals the polymeric composite coatings have potential to inhibit the corrosion of steel for oil and gas industry.
Novel Electroless Deposited Corrosion – Resistant and Anti-Bacterial NiP–TiNi Nanocomposite Coatings
Authors: Fayyad Eman , Abdullah Aboubakr , Hassan Mohamed , Pathath Abdul Rasheed , Mahmoud Khaled , Jarjoura George , Farhat Zoheir
Published: December 2020

From acidic NiP electroless bath, the co-deposition of TiNi nanoparticles in the NiP matrix to form novel NiP-TiNi nanocomposite coatings (NCCs) on top of API X100 carbon steel using several concentrations of TiNi nanoparticles (0.2, 0.4 and 0.8 g L-1 in the bath) is successfully achieved. The influence of the TiNi nanoparticles on the composition, deposition rate, thickness, and morphology of the NiP coating are investigated before and after annealing at 400 oC. The addition of TiNi nanoparticles into the NiP matrix led to the transform of the amorphous structure of the as-plated NiP into a semi-crystalline one. The microhardness of the composite coating significantly enhances with increasing TiNi concentration up to 0.4 g L-1 and further improvement takes place after heat treatment. The electrochemical impedance spectroscopy (EIS) and the colony counting method are carried out to assess the corrosion protection and antibacterial properties, respectively, of the as-deposited and the annealed coatings. The results demonstrate that there is an optimum concentration for the addition of TiNi (0.4 g L-1), which offers the composite coating with the highest corrosion protection that reaches to about 98 %. Below and beyond this concentration as well as after heat treatment, the improvement in the corrosion protection of the composite coatings slightly decreases. Besides, the NiP–TiNi NCCs have effective antibacterial properties as it decreased the cell viability of Escherichia coli from 100 to 19%.
Analyzing the Urban Heat Island Characteristics and Mitigation Strategies in Eight Arid and Semi-Arid Cities
Authors: Abulibdeh Ammar
Published: December 2020

The aim of the study is two fold: first, the study analyzes the formation of the urban heat island (UHI) in eight different cities in arid and semi-arid region. The analysis is based on land cover / land use (LCLU) classification (urban, green, and bare areas). Second, the study synthesizes the mitigation strategies to reduce the land surface temperature (LST) and hence the UHI effects in the arid and semi-arid cities. The study found that the bare areas have the highest mean LST compared to the urban and green areas. Furthermore, the study found that the LST varies in each of the LCLU categories and hence some areas of the three categories have LST lower or higher than the other categories and hence not always one category has the highest LST compared to the other categories. The outcomes of this study may have key implications for urban planners seeking to mitigate urban heat island effects in arid and semi-arid urban areas.
Managing the Water-Energy-Food Nexus on an Integrated Geographical Scale
Authors: Abulibdeh Ammar , Zaidan Esmat
Published: December 2020

The water-energy-food (WEF) nexus is the subject of much research focusing on different aspects, a wide range of issues, and development of a variety of models and tools. This study takes a different approach by developing a holistic framework that concentrates on the spatial elements of continuity and change associated with WEF transition on national, regional, and international scale. The study also investigates the interconnected challenges that could affect these resources and the actions and polices that should be taken on different geographical scales to address these challenges. The results can help practitioners and policy makers gain a clearer understanding of the state of the knowledge when performing WEF nexus assessments at different geographical scales.
Preparation of Slippery Liquid Infused Porous Surfaces on Polymeric Substrates
Authors: Popelka Anton , Habib Salma , Abusrafa Aya , Zavahir Fathima Sifani , Abdulkareem Asma
Published: December 2020

Many polymers have been found in bioscience paralleling with advancement in a technology sector. A selection of suitable polymers for using in a biomedical sector is based on many factors such as chemical nature, surface free energy or morphology, which influence cell-polymer surface interactions. However, these materials suffering from infections represent serious issues for their applications. These infections closely relate with biofilm formation, whereby microorganisms are strongly attached to surface forming strong attached multicellular communities. Therefore, a preparation of slippery liquid infused porous surfaces (SLIPS) using low-temperature plasma technique in combination with electrospinning technique was utilized in this research. A multistep physicochemical approach was carried out for this purpose. The first step includes the pretreatment of polyethylene (PE) and polyurethane (PU) substrates using low-temperature plasma to activate the surface for an adhesion improvement. Subsequently, the 3D porous network consisted of superhydrophobic fiber mats, that was fabricated on the plasma activated substrates using electrospinning technique. Final step consisted of the infusion of natural oils with emphasis on their antimicrobial effect. This complex strategy led to the effective antimicrobial modification of the PE and PU surface potentially applicable in the biomedical field.
Assessment of TPHs and PAHs in the Marine Sediment Relating to Oil and Gas Extraction activity on the western coastline of Qatar
Authors: Abdulla Maryam Abdulali
Published: December 2020

Total petroleum hydrocarbons (TPHs) and Polycyclic aromatic hydrocarbons (PAHs) are priority pollutants which are known to be associated with petroleum products. They are released into the marine environment via accidental spillage, exploration and transportation. The present study aims to assess the impact of petroleum and gas extraction activities on the pollution of coastal marine sediment of the western coastline of Qatar. Sixty-six surface sediment samples were collected along the western coastal area. The concentration of organic hydrocarbons (TPHs and PAHs) were determined using GC-FID and GC-MS, respectively. Sediment characteristics including pH, temperature, TOC and particle size were also measured. The results indicated low concentrations of TPH (<0.001-0.246 μg/g dry weight sediment) and PAHs (<0.001-0.044 μg/g dry weight sediment). The concentrations for both organic pollutants were lower compared to the previous studies done within Qatar and in the Arabian Gulf and also indicated below the available permissible limit set by the Ministry of Municipality and Environment of Qatar and other sediment quality guidelines (SQGs) used worldwide (NOAA).
Gas Sensor based on PANI/Cu-ZnS Porous Micropshere Film for CO2 detection
Authors: Parangusan Hemalatha , Bhadra Jolly , Ahmad Zubair , Mallick Shoaib , Touati Farid , Al-Thani Noora Jabor
Published: December 2020

In this letter, we report the structural, morphological and CO2 gas sensing properties of the polyaniline (PANI) coated Cu-ZnS microspheres. PANI coated Cu-ZnS microspheres were prepared by hydrothermal and in-situ polymerization method. X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to investigate the structural and morphological properties. The fabricated sensor based on PANI coated Cu-ZnS microspheres exhibits good CO2 sensing performance with rapid response (31 s) and recovery (23 s) times.
DFT-MD Dissolution of Oilfield Pyrite Scale using Borax
Authors: Onawole Abdulmujeeb T. , Hussein Ibnelwaleed A. , Ahmed Musa E.M. , Saad Mohammed A. , Aparicio Santiago
Published: December 2020

Introduction: Oilfield scales including pyrite form in oil and gas pipelines, underground tubing, and surface equipment thus blocking the flow of fluids and hindering production. Hence, the need for the development of effective chemicals in scale dissolution and removal. Materials and methods: A computational technique known as Density Functional Theory- Molecular Dynamics (DFT-MD) was employed to investigate the use of borax in scale dissolution. This method aids the understanding at the atomic level of scale dissolution by using Quantum ATK’s virtual Nano lab and VASP for model building and DFT-MD calculations respectively. Geometrical studies and radial distribution functions were carried out for data analysis. Results: The results show that potassium ion preferentially bonds to the sulfur atoms in the top layer of the pyrite surface rather than with iron. Hence, becoming the predominant factor that is responsible for pyrite dissolution. The K-S bonds evolve dynamically and expose the rest of the pyrite surface. Conclusions/future directions: The presence of a chelating agent alongside borax would prevent Fe-S bond formation. Hence, it is proposed that borax, in conjunction with chelating agents, would be efficient in pyrite scale dissolution and removal. This technique can be used to study other iron sulfide scales such as troilite and greigite, which have different iron to sulfur ratio compared to pyrite. This will consequently help boost production in the upstream sector.
Wind Energy Potential along the Onshore and Offshore Qatar
Authors: Mohammed Aboobacker Valliyil , Al-Ansari Ebrahim M.A.S. , Razak Shanas Puthuveetil , Subramanian Veerasingam , Ponnumony Vethamony
Published: December 2020

Wind energy is one among the clean and renewable energy resources. The utilization of nonconventional energies over the conventional sources helps to reduce the carbon emissions significantly. The present study aims at investigating the wind energy potential at select coastal locations of Qatar using ERA5 winds. ERA5 is the updated reanalysis product of the European Centre for Medium-range Weather Forecasts (ECMWF), in which the scatterometer and in situ wind data are assimilated to improve the accuracy of predictions, thus the long-term and shortterm variabilities are reasonably well captured. Compared to the earlier studies, in this work, we have assessed the wind power at inland and offshore areas of Qatar, considering 40-year long (1979-2018) time series data with hourly ERA5 winds at 10-m height. The results show that there is no significant increase or decrease of wind power around Qatar in the last 40 years in most of the locations, while there is a slight decreasing trend in the offshore areas of Al Ruwais. This indicates that the average wind power is consistently available throughout the years. The links of climatic indices, especially the ENSO events with the wind climate of Qatar, are clearly evident in the long-term data. As obvious, the offshore regions of Qatar have relatively high wind power compared to the land areas. Among the selected locations, the highest annual mean wind power density is obtained in the offshore Al Ruwais (152 W/m2), followed by offshore Ras Laffan (134 W/m2) and land area of Al Khor (120 W/m2). The maximum wind power density varies between 1830 and 2120 W/m2 in the land areas, while it is between 1850 and 2410 W/m2 in the offshore areas of Qatar. The highest wind power is consistently available during the prevalence of shamal winds in winter (January-March) as well as summer (June).
Electrical Equivalent Circuit (EEC) based Impedance Spectroscopy analysis of HTM free Perovskite Solar Cells
Authors: Ahmad Zubair , Mishra Arti , Abdulrahim Sumayya Muhammad
Published: December 2020

Monolithic Perovskite solar cells (mPSCs) are the multi-layered organic-inorganic hybrid cells that have been focused due to the affordable cost, ease of fabrication and noteworthy power conversion efficiency (PCE). In this research, we have carried out a systematic study to understand the physical phenomenon inside successive layers of the mpscs using the impedance spectroscopy (IS). This study was performed on the optimized mPSCs with power conversion efficiency over 13%, where CH3NH3PbI3, Perovskite has been used as light absorber. The internal electrical processes at the interfaces of the layers of mPSCs devices have been studied and correlated to produce electrical equivalent circuit of the overall device.
Multiphase Induction Motor Drives for Gear-Less Electric Vehicle Applications
Authors: Iqbal Atif , Al-Hitmi Mohammed , Praprath Asokan
Published: December 2020

Qatar has some major research priorities, targeting; reducing carbon footprints, developing smart cities and smart grids; and these demand high deployment of electric cars in near future. Qatar is an highly progressive country adopting to new evolving technologies at a fast pace. The proposed project is aimed at the development of a robust, highly reliable, efficient and wide speed range multiphase motor drive system that falls within the right context of the current research priorities of the Qatar University and the State of Qatar. The idea here is to use pole phase modulation technique to enhance the speed-torque control region of a multiphase motor drive system so that gear-less opeartion can be achieved in EV. Advantages and Disadvantages of the proposed pole phase modulated IM drives:  In high pole operation, the PPMIM drive is able to supply the high initial torque for fast acceleration and hill climbing.  The rated torque of the PPMIM drive in the high pole is k times greater than the low pole mode. For example, in 3-phase 12-pole mode, the 9-phase PPMIM drive is able to supply 3 times of the rated torque as comparted to 9-phase 4-pole mode.  In low pole mode, the PPMIM drive is able to supply high speed which is k times greater than the high pole mode.  The PPMIM drives are capable to generate 3 or 4 speed and torque variations. So, the mechanical gearbox system in conventional IC Engine based vehicles can be eliminated with the PPMIM drives, which will reduce the size and weight of the vehicle. Even though the PPMIM drives have several advantages (as mentioned above), on the other side they have a few disadvantages also such as:  To achieve the high starting torque in high power applications, the PPMIM drives has to operate in high pole and low phase mode, which magnifies the magnitude of space harmonics in the air gap.  The magnetizing inductance of the machine is inversely proportional to the square of the number of poles, which lowers the power factor.
Multiple Output Contactless Inductive Power Transfer System for Electric Vehicle Battery Charging Station
Authors: Al-Hitmi Mohammed , Iqbal Atif , Hassan Anwarul , Shakoor Abdul , Kahraman Ramazan
Published: December 2020

The proposed system is designed to charge the three different duty vehicles (based on the charging power): heavy-duty vehicle, medium-duty vehicle and small duty vehicle through three different modules (Module-A, B and C) which are connected to one common DC bus. In the proposed system, each module consists of two inductive coils. One is embedded into EV body along with a rectifier and DC-DC converter as a receiver. However, another coil is embedded into the road (on the ground) along with DC-DC converter and high-frequency inverter as a transmitter. Additionally, each module consists of two matching networks with a compensation circuit for effective power transfer. For the analysis and designing of rapid fast charger for different duty range EV, the typical specification of different duty range EV are used. For fast charging of heavyduty range EV, required charging voltage and current are high (600A/550A) as compared to medium (350V/135A) and low (200V/125A) range EV. To achieve these requirements, different ratings of the converter are utilized in the respective charger. In the proposed system, the dedicated qZS boost converter is utilized to boost the input voltage up to required high voltage demand. However, the receiver buck converter steps down the voltage (step current) to the required level to charge the battery. In the proposed system, by controlling the buck converter the battery is charged either in CC or CV mode. Additionally, the two matching networks together compensate for the capacitive reactance of the coupling plates. The proposed system provides rapid DC charging for different duty range EVs from the AC grid along with a controlled rectifier or DC grid thereby reducing the cost, volume density, and complexity of the charging system.
Innovative Nanostructured Membranes for Reverse Osmosis Water Desalination
Authors: Saleem Haleema , Zaidi Syed Javaid
Published: December 2020

Reverse osmosis (RO) is considered as the most widely utilized technique worldwide for water treatment. However, the commercial thin-film composite (TFC) membranes, which are normally made of polyamide (PA) through interfacial polymerization (IP), still experience certain major issues in performance and fabrication. The spin assisted layer-by-layer (SA-LbL) technique was established for overcoming some drawbacks with commercially available PA membranes. Also, recent investigations have recognized the nanoparticle inclusion into the selective layer as a powerful technique for improving the membrane efficiency. Hence, two different methodologies are presented here to improve the membrane performance, i.e., (1) SA-LbL technique to fabricate TFC membrane by the deposition of alternate ultrathin layers of different polyelectrolytes on polysulfone (PSF) commercial ultrafiltration membrane and (2) the nanoclay incorporation into the membranes during IP process to develop TFC membrane. Two types of nanoclays, cloisite (CS)-15A and montmorillonite (MNT), were incorporated to enhance the separation efficiency. This SA-LbL is an innovative method for the RO membrane manufacture, and has not been described earlier to the best of our knowledge. In addition, this work validated for the first time, the efficiency of the two nanoclays at the PA selective layer in the RO membrane. The membrane performance was evaluated using sodium chloride solution in a cross-flow permeation-testing cell for salt rejection and water flux. The results show significant improvement in water flux and salt rejection. The permeation test of 120 bilayers of poly (allylaminehydrochloride)/poly (vinylsulfate) on PSF substrate showed water flux of 37 L/ (m2.h) and salt rejection of 53%, for a 2000-ppm salt solution feed. The highest water flux of 40 L/m2.h with 80% salt rejection, relative to the control membrane was obtained for the membranes containing nanoclays at 25oC temperature, 40.0 bar pressure and 2000 ppm feed concentration. Thus, our study demonstrated that these TFC membranes are promising, and these novel fabrication techniques are great tool to manufacture the RO membrane.
RELATIONSHIP AMONG MATERNAL, PRENATAL AND PREGNANCY OUTCOME IN RANGELI MUNICIPALITY OF NEPAL
Authors: Mahato Asmita , Shrestha Barsha
Published: December 2020

Background: The incidence of pregnancy complications may be due to risk factors during pregnancy. Whether maternal parameters like age, gravida/ parity, gestational age, and fetal heart rate have any influence to the delivery outcome and newborn weight is a big quest. A young age at birth is more common in Nepal and carries a less social stigma, and hence enforces this study to understand the impact.

Objective and methodology: The objectives of this retrospective study were to evaluate the maternal and prenatal outcomes of pregnancies and the effects of the age of the pregnancy, gravida, gestational age, and newborn weight. Pregnant women giving birth in Rangeli Hospital, Morang (Nepal) in 2019 were retrospectively screened. Pregnant women of all age group were included in this study.

Results: Mean maternal age for delivery of child was 22.45 ±0.225 years. 41.9% of study subjects were primigravida (G1), while 58.1% were multi-gravida (G2-4). The mean age of primigravida is 20.57 ±0.025 years. Mean gestational week, fetal heart rate (FHR), and newborn weight were 38.18 ±0.11, 140.91 ±0.43, and 2870.65 ±26.13 g respectively. Almost one-third (32.1%) of the newborn were preterm babies. 20.9% of the newborn child was low birth weight. Spontaneous vaginal delivery was seen in 90.7% of the pregnancy while 7.9% had caesarean section.

Conclusion: A significant positive correlation was seen of age with gravida, parity, and newborn weight. Newborn weight was significantly related to gestational age. There is no significant difference between the mean maternal age of mother delivering preterm baby or term-baby. No significant difference in the mean age of the mother or the mean gestational duration between male and female children could be established. Significant mean differences were seen in the maternal age of LBW child and normal birth weight child.
Alberta's Energy and Utilities Board and the Constitution of Canada
Authors: Vlavianos Nickie
Published: December 2020

The author explores the jurisdictional ability of an administrative tribunal — specifically, the Alberta Energy and Utilities Board (EUB) — to decide constitutional matters. She focuses particularly on tribunal decisions relating to Charter rights and Aboriginal or treaty rights (s. 35(1)) and examines the recent decisions of Martin and Paul from the Supreme Court of Canada. The author concludes that for questions of law, the EUB has not only the option but the duty to consider constitutional questions.
Supreme Court Restates Directors' Fiduciary Duty - A Comment on Peoples Department Stores v. Wise
Authors: MacPherson Darcy L.
Published: December 2020

This article considers the implications of the recent Supreme Court of Canada decision in Peoples Department Stores v. Wise for the law of directors' fiduciary duties. The Court’s decision is attacked on two grounds.

First, the author criticizes the Court’s interpretation and treatment of the phrase "the best interests of the corporation" as found in the Canada Business Corporations Act. It is argued that the decision in Wise rejects the traditional interpretation of this phrase which was previously accepted to mean "the best interests of the shareholders collectively. " This rejection raises the spectre of the debate between the "shareholder primacy " model of directors' duties and broader "pluralist" alternatives. By undercutting the lynchpin of the "shareholder primacy" model, the author suggests that the Court has left a vacuum in the law because the Court failed to outline what is to replace this traditional interpretation, or even to acknowledge the substantive change being made. At the level of process, it is equally suggested that the revision of important principles in corporate law exclusively through the judiciary is fundamentally undesirable, where the law of directors' duties has such a large element of public policy attached to it. The author also proposes that the decision in Wise has resulted in an unacceptable level of uncertainty in the law, and that this uncertainty was neither necessary nor advisable to resolve the case before the Court.

Second, the author criticizes the Court's comments indicating that a breach of fiduciary duty requires mala fides on the part of directors. It is argued that this is inconsistent with pre-existing case law.
Myxomycetes of Russia: a history of research and a checklist of species
Authors: Bortnikov F. M. , Matveev A. V. , Gmoshinskiy V. I. , Novozhilov Yu. K. , Zemlyanskaya I. V. , Vlasenko A. V. , Schnittler M. , Shchepin O. N. , Fedorova N. A.
Published: December 2020

The main objective of this paper is to provide an overview of the history and the level of research on biodiversity of myxomycetes in Russia. The first doubtless mention of myxomycetes in Russia dates back to the 18th century. Since then, numerous studies on myxomycete diversity in different regions of Russia have been published. Yu.K. Novozhilov summarized all accumulated data by publishing a list of 304 species in 2005. However, new data on species diversity, biogeography, and ecology of myxomycetes have been published in recent years. Recent research aims to fill this gap. This paper includes 321 sources, including studies published after 2005 and several works absent in previous reports. A full list of 455 myxomycete species found in Russia includes references to all literature sources. The analyzed database consists of more than 14 600 records in the "publication-region-species" format. Additionally, our research includes a detailed historical overview of the myxomycete studies in Russia. We hope that our information system, also available online at https://russia.myxomycetes.org/, will create a solid foundation for future studies of myxomycete biodiversity in Russia, particularly in the understudied regions.
Results of laparoscopic extravesical antireflux operation in vesicoureteral reflux in children
Authors: Dubrov V. I. , Strotsky A. V.
Published: December 2020

The objective was to improve the results of surgical treatment of vesicoureteral reflux in children, using laparoscopic access. The prospective study was performed in 111 children (137 ureters) with the primary III–IV grade vesicoureteral reflux. The mean age was 34.7 months. The modified laparoscopic antireflux technique was performed on 73 children (91 ureters). We compared the perioperative complications and the medium-term outcome with a group of 38 children (46 ureters) who underwent classical laparoscopic extravesical reimplantation.3 In the modified group, the mean surgery time was 109.8 ± 31.5 minutes for unilateral cases and 176.5 ± 47.6 minutes for bilateral cases; in the classical group, it was 118.6 ± 34.3 and 209.5 ± 51.2 minutes respectively (p > 0.05). Postoperative vesicoureteral reflux had 2 (2.7 %) patients in the main group and 8 (21.1 %) children in the control group (p  =  0.002). There was no ureteral obstruction in the both groups. The success rate for ureters was 97.8 % with modified technique versus 82.6 % after classical laparoscopic reimplantation (p = 0.003). Laparoscopic extravesical ureteral reimplantation is a safe and effective surgical procedure. The modified technique may improve the surgical treatment results.
Role of calcitriol in modulating of placental dysfunction in pregnant women with chronic kidney disease
Authors: Manasova G. S. , Didenkul N. V. , Mnich L. V. , Chumak Z. V. , Kuzmin N. V.
Published: December 2020

The pleiotropic effects of vitamin D (VD), whose active form is synthesized in the kidneys, play a certain role both in forming and functioning the feto-placental system, including various pregnancy complications. The aim of the study was to evaluate the vitamin D status in pregnant women with placental dysfunction (PD) and chronic inflammatory kidney disease (CIKD). During 24–34 pregnancy weeks, 56 pregnant women with PD were examined (main group ‒ I); 24 patients (42.85 %) had chronic pyelonephritis (group IA). The control group (group II) had 31 conditionally healthy pregnant women. The total VD level in the blood was determined by ELISA; in addition to the general clinical standard examination, the urine also underwent bacteriological examination. The VD mean level in pregnant women with PD and CIKD was significantly lower than that in the control group (31.08 ± 7.2 and 45.42 ± 9.67 ng/ml (p <0.01)). Only 33.33 % of pregnant women in group IA had a VD optimum, as well as 93.55 % (p < 0.01) in the control group and 17.86 % in group I. 8.33 % of pregnant women had a VD deficiency in group IA (RR = 2.09; CI 95 % ‒ 1.8‒2.42). The patients with a VD-deficiency were absent in the control group. 58.33 % of women in group ІА had a suboptimal VD level and 6.45% in the control group (RR = 3.57; CI 95 % ‒ 1.62‒7.88). Bacteriuria was observed in all pregnant women with a VD-deficient or suboptimal level. At the optimum VD level, bacteriuria was diagnosed twice less (χ2 = 66.67; p <0.01). In patients with an inadequate VD level, CIKD was diagnosed 3.8 times more (RR = 3.57; CI 95 % ‒ 1.62‒7.88). 494 Proceedings of the National Academy of Sciences of Belarus. Medical series, 2020, vol. 17, no. 4, pp. 493–499 A significantly calcitriol reduction in pregnant women with placental dysfunction suggests that the deficiency or the suboptimal level of vitamin D and inflammatory kidney diseases may be the interdependent processes that play a decisive role in the formation of placental dysfunction.