bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Nano Silica prepared from Iraqi Rice Husk and its Application in Oil Well’s Cement
Authors: Saleh Najat. J. , Abdulrahman Amer. A. , Yousif Zakia. A. 
Published: May 2021

Iraqi Rice husk (IRH) was used to produce nanosilica by precipitation method. The prepared silica nanoparticles samples were characterized using different analytical techniques, these included FTIR, XRD, SEM ,AFM and and,TEM. X-Ray fluorescence (XRF) was used for the quantitative determination of chemical composition of rice husk which revel that it contains 94.22% silica, after acid leaching it gave 99.04% silica. at 700 oC. FTIR showed bending and stretching absorption bands Si-O-Si at (797) cm-1, (1078) cm−1. X-Ray diffraction shows a strong broad characteristic peak of nano pure silica at ≈ 22°. Electron microscope image characterize particles size of (60) nm in spherical shape and agglomerated form. The observation by Atomic Force Microscope shows that the average diameter of particles 88.87 nm.The prepared nanosilica from rice husk has a surface area of(194m2/g) and pore volume of (0.275 cm3/g).
Nanosilica pozzolanic material was used as cement admixture in oil field cement to improve compressive strength. The nanosilica cement admixture compressive strength was increase 8%, 9% and 4% at 1.5%, 2%, 2.5% nanosilica percentage adding respectively by weight of cement at 38 oC and 0.1%, 9%, 7% compressive strength percent increase at 60 oC.
Keywords: Iraqi rice husk, Nanosilica, Oil well, cement-admixture.
تنمية المحتوى الوطني (المحلي) في صناعة النفط والغاز وآليات تحسين الأداء
Authors: اسماعيل HILAL ALI 
Published: May 2021

يلقي هذا البحث الضوء على تجارب عدد من البلدان التي تبنت مفهوم المحتوى المحلي وتنميته كأسلوب وأداة في تحقيق التنمية الاقتصادية الشاملة واستدامتها، ونجحت في تحويل ثروة المصادر الطبيعية من نفط وغاز ومعادن الى ازدهار طويل الأمد لشعوبها وطورت مضامين هذا المفهوم بتبني مجموعة من القواعد والسياسات والخطط والبرامج ليصبح واحدا من أدوات زيادة الدخل الوطني فيها وليعتمد كأحد المتطلبات الاساسية في العقود الموقعة مع الشركات الاجنبية وبالخصوص في البلدان المنتجة لمصادر الطاقة من نفط وغاز وليصبح ركناً مهما في نقل وتوطين التكنولوجيا وزيادة المعارف والخبرات وخلق الوظائف وتشغيل وتأهيل الأيدي العاملة الوطنية ودعم الصناعة الوطنية وتطوير جهود البحث العلمي.
يتناول البحث تجربة العراق المتواضعة والسبيل الى تطويرها وفتح آفاق جديدة أمام الصناعة الوطنية الناشئة عبر أتخاذ حزمة من الإجراءات في قطاع النفط والغاز مع الشركات الأجنبية العاملة في عقود التراخيص النفطية والمشاريع الاستثمارية المخطط تنفيذها وأهمية صياغة البنود التعاقدية وإجراءات التقييم والمتابعة لتنمية هذا المحتوى وبما يحقق أقصى المنافع الوطنية، حيث لا تتوفر لدى وزارة النفط آليات تجميع البيانات الأحصائية الأجمالية عن حجم الأيدي العاملة العراقية العاملة بمعية المقاوليين المتعاقديين مع الشركات النفطية الاستخراجية (العامة) ومجموع الأجور والمنافع السنوية لهذه العمالة والشركات والمكاتب المحلية (الخاصة) المنخرطة في تنفيذ ألتزامات المقاول وحجم المساهمة المادية الى مبلغ العقد الرئيسي، أضافة الى قيمة المال المنفق على أنشطة التدريب والتطوير ونقل المعارف والخبرات للعراقيين الى حجم الانفاق الاجمالي وكذلك المصروف السنوي على مشاريع المرافق والبنى التحتية العامة...بسبب غياب آليات ومؤشرات قياسية دقيقة بالأسس النقدية لحساب قيمة المحتوى الوطني في مجمل هذه الأنشطة ومتابعة نموه وحساب القيمة المضافة الكلية المتولدة عنه.
قياس فجوة تطبيق نظام إدارة الطاقة وفق المواصفة ISO 50001:2011/ دراسة حالة في شركة نفط الشمال
Authors: جوير THU ALFIQAR , شاهين Dr. nidaa 
Published: May 2021

يهدف البحث الى قياس الفجوة بين الواقع الفعلي ومتطلبات نظام إدارة الطاقة وفقاً للمواصفة (ISO 50001:2011) في شركة نفط الشمال، اذ ينطلق البحث من المشكلة المتمثلة بالاستهلاك العالي وغير المراقب وغير المسيطر عليه لمصادر الطاقة الأربعة التي تعتمدها شركة نفط الشمال وهي (الكهرباء، البنزين، الديزل، المياه)، والتأثيرات السلبية على البيئة الخارجية والداخلية الناتجة عن سوء استهلاك الطاقة، وبقصد الوصول إلى الحقائق العلمية اعتمد منهج دراسة الحالة الذي يتضمن الملاحظة والمعايشة الميدانية واللقاءات المباشرة، كما استعملت قائمة الفحص (Checklist) للوصول الى المعلومات، وتظهر نتائج البحث وجود فجوات كبيرة بين الواقع الفعلي ومتطلبات المواصفة (ISO 50001:2011)، فقد أظهرت نتائج التقييم وجود فجوة كلية لمصدر الكهرباء قدرها (0.57)، كما بلغت الفجوة الكلية لمصدر البنزين (0.62)، وقد بلغت الفجوة الكلية لمصدر الديزل (0.65)، فضلاً عن حجم الفجوة الكلية لمصدر المياه (0.82).
الكلمات الرئيسة: إدارة الطاقة، نظم إدارة الطاقة، المواصفة القياسية (ISO 50001:2011).
The Petroleum System of Zubair Formation in Zubair Subzone, Southern Iraq
Authors: Idan Rami M. , Al-Musawi Furat A. , Salih Amani L. M. , Al-Qaraghuli Shahad A. F. 
Published: May 2021

The Lower Cretaceous Zubair Formation is the most important reservoir in the south of Iraq and adjacent countries, as well as the shale intervals, may be the possible source rock. The parameters of the possible source rock within Zubair Formation are accepted, regarding quantity, quality, and thermal maturity.
From the total organic carbon values standpoint, shale intervals of Zubair Formation are generally good source rocks, except in the lower parts. While the kerogen types are generally type III gas-oil prone, mix type II/III, and type II oil-prone. The main type of organic matters was amorphous organic matters, which is principally related to oil-prone source rock.
The Rock-Eval Pyrolysis shows that the organic geochemical properties presented an effective and/or potential source rock depending on the values of S1, S2, and S3 and their derivatives. The source rock has started the oil expulsion, where the S1/TOC values were mainly more than 0.2 mg HC / g TOC.
The modelling explains that the Zubair Formation, wholly, has been entered the onset, partially, the peak, and rarely the end of oil generation in the studied Subzones. This conclusion depends on the calculated temperatures, geothermal gradients, and Vitrinite reflectance calibration.
Epidemiology of Covid-19 Positive Patients Admitted In a Dedicated Covid Hospital
Authors: Yadav Vikas , Kumar Sunil , Yadav Renu 
Published: May 2021

Introduction: The pandemic of Covid-19 was declared on 11 march 2020 by WHO.
Methods: The study was carried out in a dedicated Covid 19 hospital on 1493 patients. All patients who tested positive for Covid-19 by RTPCR were included in the study and the outcome was analysed.
Result: Most of the patients were symptomatic (64.97%). The asymptomatic patients recovered faster than symptomatic and the difference was statistically significant. The most common symptoms were fever (38.3%), tiredness (20.6%) and cough (17.8%). Only 0.8% patients died due to the novel corona virus.
Conclusion: The mortality due to the virus in India is not alarming and we need to consider starting focusing back on other diseases as well. The mean age of the deceased was 58.42 which highlights that elderly at a greater risk to succumb to disease and hence should be preferred for as priority one for vaccination against the disease. The numbers of Covid-19 cases have reduced considerably over last few months in the country, but this does not mean that the pandemic has gone away. We need to be cautious, use this opportunity to vaccinate the maximum population to prevent second wave of the disease.
Notariële ambtsethiek als constante in de opleiding van de notaris: de deugd in het midden
Authors: Waaijer Boudewijn 
Published: May 2021

Notariële ambtsethiek als constante in de opleiding van de notaris: de deugd in het midden; Special issue on Education in (Professional) Legal Ethics, Emanuel van Dongen & Jet Tigchelaar (eds.)
Behandeld wordt de vraag of en hoe door educatie een bijdrage kan worden geleverd aan beroepsethisch handelen in het notariaat. Ik doe dat door de opleidingseisen te differentiëren al naar gelang de verschillende gedaanten die de notarieel jurist aanneemt: die van student, beginnend notarieel jurist en notarieel jurist met een afgeronde beroepsopleiding.
Evaluación Remota de Aprendizajes en la Universidad: decisiones docentes para encarar un nuevo desafío
Authors: Schwartzman Gisela , Roni Carolina , Berk Michelle , Delorenzi Erica , Sánchez Mariana , Eder María Laura 
Published: May 2021

La pandemia por COVID-19 y la suspensión de actividades presenciales enfrentó a las universidades con el desafío de remotizar sus funciones. Este trabajo se propone caracterizar propuestas de evaluación de aprendizajes diseñadas, al inicio del confinamiento, por docentes de grado y posgrado de ciencias de la salud en el contexto de una propuesta de Formación para la Virtualización de la Enseñanza (FVE) de un Instituto Universitario. Este estudio descriptivo-interpretativo analiza, desde un enfoque cualitativo, 51 planificaciones docentes de evaluación remota elaboradas en el contexto de la formación ofrecida. Las mismas se organizaron en una matriz documental para su categorización e identificación de rasgos prevalentes en estos diseños didácticos con el fin de construir hipótesis interpretativas. Se evidencian propuestas diversas que mayormente evalúan los aprendizajes con intención de acreditar saberes. Prevalecen diseños de evaluación individual con un uso activo del conocimiento ligado a prácticas académicas y profesionales. Un gran porcentaje prevé su desarrollo en forma asincrónica, mediados por la escritura y con el uso de un amplio repertorio de herramientas digitales. Estas propuestas jerarquizan el andamiaje docente a estudiantes durante el proceso de evaluación. Finalmente, se sistematizan los campos emergentes que estructuraron el diseño de las propuestas de evaluación remota de los aprendizajes. Se genera así un insumo para pensar las prácticas evaluativas en el contexto de remotización de la enseñanza. Esperamos que esta contribución trascienda el escenario actual para identificar potencialidades ante la construcción de propuestas híbridas en la post pandemia y en otras disciplinas universitarias.
A la búsqueda del médico bueno: los conflictos de intereses en las relaciones con la industria farmacéutica
Authors: Verdú González Irene 
Published: May 2021

El declive sufrido por las profesiones clásicas ocasionó que, tras siglos de ejercicio autócrata de la profesión médica —e innumerables privilegios— fuese necesaria una renovación de los valores y principios inspiradores del contrato que les vincula a la sociedad. Ello exigía que, paralelamente, se recuperasen los principios éticos y virtudes que caracterizan a un excelente profesional, reformulándolos para adaptarlos a las nuevas exigencias de la sociedad. En consecuencia, la relación clínica pasó de la estricta intimidad médico-paciente a estar influida por otros sujetos que desvían la atención de los médicos de aquellas metas propias de su profesión. De entre estos sujetos, destaca notoriamente la industria farmacéutica, cuyo poder ha influido en la vocación que une al médico con su profesión, debilitándola y haciendo tambalear los cimientos de la moral propia de estos profesionales.
The decline suffered by classical professions, after centuries of autocracy in the medical profession —and uncountable privileges— forced a renewal of the values and inspiring principles of the contract that binds them to society. This required, at the same time, the reformulation of ethical principles and virtues that characterize an excellent professional, in order to adapt them to the new demands of society. Consequently, the clinical relationship went from strict doctor-patient intimacy, to being influenced by other subjects who divert medical attention to the goals of their profession. Out of these subjects, the pharmaceutical industry stands out notably. Their power has influenced the vocation that unites the doctor with his profession, weakening it and shaking the foundations of the morale of said professionals
An effective classification framework for brain-computer interface system design based on combining of fNIRS and EEG signals
Authors: Alhudhaif Adi 
Published: May 2021

Background
The brain-computer interface (BCI) is a relatively new but highly promising special field that is actively used in basic neuroscience. BCI includes interfaces for human-computer communication based directly on neural activity concerning mental processes. Fundamental BCI components consist of different units. In the first stage, the EEG and NIRS signals obtained from the individuals are preprocessed, and the signals are brought to a certain standard.

Methods
In order to realize proposed framework, a dataset containing Motor Imaginary and Mental Activity tasks are prepared with Electroencephalography (EEG) and Near-Infrared Spectroscopy (NIRS) signal. First of all, HbO and HbR curves are obtained from NIRS signals. Hbo, HbR, HbO+HbR, EEG, EEG+HbO and EEG+HbR features tables are created with the features obtained by using HbO, HbR, and EEG signals, and feature weighted is carried out with the k-Means clustering centers based attribute weighting method (KMCC-based) and the k-Means clustering centers difference based attribute weighting method (KMCCD-based). Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), and k-Nearest Neighbors algorithm (kNN) classifiers are used to see the classifier differences in the study.

Results
As a result of this study, an accuracy rate of 99.7% (with kNN classifier and KMCCD-based weighting) is obtained in the data set of Motor Imaginary. Similarly, an accuracy rate of 99.9% (with SVM and kNN classifier and KMCCD-based weighting) is obtained in the Mental Activity dataset. The weighting method is used to increase the classification accuracy, and it has been shown that it will contribute to the classification of EEG and NIRS BCI systems. The results show that the proposed method increases classifiers’ performance, offering less processing power and ease of application. In the future, studies could be carried out by combining the k-Means clustering center-based weighted hybrid BCI method with deep learning architectures. Further improved classifier performances can be achieved by combining both systems.
Prevalence, Pattern and Clinical Variations of Dermatophytosis in Patients with HIV Infection at the University of Port Harcourt Teaching Hospital, Port Harcourt
Authors: Altraide Dasetima D. , Amaewhule Mary N. , Otike-Odibi Bolaji 
Published: May 2021

Background: Immunosuppression due to various etiologies has been associated with the occurrence of dermatophytosis. Several studies in the past have demonstrated that Human Immunodeficiency Virus (HIV) infection is a risk factor for the acquisition and severity of dermatophytosis. This study examined the prevalence and clinical variations of dermatophytosis amongst HIV positive patients seen in Port-Harcourt, Southern Nigeria.
Methods: Between July 2019 and 2020 173 seropositive cases and 173 seronegative controls were recruited for this study. They were interviewed with a structured questionnaire and thereafter screened for the presence of dermatophytosis and sent for mycology studies.
Results: There was a higher prevalence of dermatophytosis in the HIV seropositive group when compared to the control group. Most of the lesions seen were not markedly different from that seen in immunocompetent persons. 41.65% of the cases were found among those with CD4 cell counts below 200. Tinea corporis was the commonest lesion seen (50%). Trichophyton species was the commonest dermatophyte isolated, followed by Microsporum spp.
Conclusion: Prevalence of dermatophytosis is significantly higher in HIV infected patients and commonly occurs in advanced stages of the disease. Tinea corporis is the most common lesion in this group of patients and Trichophyton spp. a common causative agent.
Effect of temperature on the sex ratio and life table parameters of the leek‐(L1) and tobacco‐associated (T) Thrips tabaci lineages (Thysanoptera: Thripidae)
Authors: Woldemelak Wondimagegn Atilaw , Ladányi Márta , Fail József 
Published: May 2021

AbstractTemperature strongly affects insect biological response. Effects of temperature on the sex ratio, preoviposition, fecundity, egg hatchability rate, and adult longevity of the L1 and T Thrips tabaci lineages were studied under laboratory conditions at three constant temperature levels (15, 23, and 30°C) on cabbage and tobacco leaf discs, respectively. Results showed that temperature affects all the tested life table parameters of L1 and T lineages. The proportion of female's log‐linearly increased as temperature increased. Preoviposition period, fecundity, adult longevity, and egg hatchability rate were reduced significantly with increasing temperature. In both lineages, the lowest egg hatchability rates were recorded at 30°C and the highest rates were recorded at 15°C. Mean fecundity of the L1 and T lineages were 107.63 and 84.83 at 23°C, respectively, and mean fecundity of the L1 and T lineages were 19.88 and 70.82 at 15°C, respectively. The lowest mean fecundity was recorded at 15°C and 30°C for the L1 and T lineages, respectively. Mean longevity were 34.22 and 81.82 days at 15°C for L1 and T lineages, respectively. Whereas, the shortest mean longevity (13.63 and 13.91 days) was observed at 30°C for the L1 and T lineages, respectively. Our results demonstrated that 23°C was the optimum temperature for fecundity among the studied temperature levels for the studied population of the L1 and T T. tabaci lineages.
Evaluation of SrAl2O4:Eu, Dy phosphor for potential applications in thermoluminescent dosimetry
Authors: Tang Xueyan , Ehler Eric D. , Brost Eric , Mathew Damien C. 
Published: May 2021

AbstractPurposeTo evaluate the use of commercial‐grade strontium aluminate phosphorescent powder as a thermoluminescent (TL) dosimeter for clinical radiotherapy beams.Materials and MethodCommercially available Eu2+, Dy3+ co‐doped strontium aluminate powder (SrAl2O4:Eu, Dy) was annealed and then irradiated using 20 × 20 cm2 field size, with 6‐MV (PDD10 = 70.7) and 18‐MV (PDD10 = 79.4) photon beams and and 9‐MeV (R50 = 3.6), 15 MeV (R50 = 5.9) and 18‐MeV (R50 = 7.2) electron beams. To calibrate the relationship between the TL readings and the irradiated doses, TL glow curves were acquired for doses up to 600 cGy at all beam energies. For the percentage depth dose (PDD) measurement, the SrAl2O4:Eu, Dy powder was sandwiched by solid water phantoms, with varying thickness of solid water placed above to determine the depth. PDDs were measured at four representative depths and compared against the commissioning depth dose data for each beam energy.ResultsLinear dose response models of doses up to 200 cGy were created for all beam energies. Superlinearity was observed with doses greater than 200 cGy. The PDD measurement acquired experimentally agrees well with the commissioning data of the medical linear accelerator. Trapping parameters such as order of kinetics, activation energy and frequency factor have been obtained via TL glow curve analysis.ConclusionThe linear dose response demonstrates that SrAl2O4:Eu, Dy is a potential TLD dosimeter for both electron beams and photon beams at different beam energies. The PDD measurements further support its potential use in quality assurance and radiation dosimetry.
Exercise leads to metabolic changes associated with improved strength and fatigue in people with MS
Authors: Keller Jennifer , Zackowski Kathleen , Kim Sol , Chidobem Ikechukwu , Smith Matthew , Farhadi Farzaneh , Bhargava Pavan 
Published: May 2021

AbstractObjectiveThe goal of this exploratory study was to evaluate the effects of an exercise intervention – progressive resistance training (PRT) on the metabolome of people with MS (pwMS) and to link these to changes in clinical outcomes.Methods14 pwMS with EDSS <4.0 and 13 age‐ and sex‐matched healthy controls completed a 12‐week in‐person PRT exercise intervention. Outcome measures included: plasma metabolomics analysis, cardiovascular fitness tests, EDSS, timed 25‐foot walk (T25FW), six‐minute walk test (6MWT), hip strength, and modified fatigue impact scale (MFIS). We identified changes in the metabolome with PRT intervention in both groups using individual metabolite abundance and weighted correlation network defined metabolite module eigenvalues and then examined correlations in changes in metabolite modules with changes in various clinical outcomes.ResultsIn both groups PRT intervention improved hip strength, distance walked in 6WMT, speed of walking, while fatigue (MFIS) was improved in pwMS. Fatty acid, phospholipid, and sex steroid metabolism were significantly altered by PRT in pwMS but not in controls. Changes in fatigue (MFIS score) were strongly inversely correlated and hip strength was moderately correlated with change in sex steroid metabolite module in pwMS. A similar relationship was noted between change in dehydroepiandrosterone sulfate abundance (sex steroid metabolite) and fatigue in pwMS. We also noted an inverse correlation between changes in fatty acid metabolism and cardiovascular fitness in pwMS.InterpretationPRT‐induced metabolic changes may underlie improved clinical parameters in pwMS and may warrant investigation as potential therapeutic targets in future studies.
Nb‐Mediated Grain Growth and Grain‐Boundary Engineering in Mg3Sb2‐Based Thermoelectric Materials
Authors: Luo Ting , Kuo Jimmy J. , Griffith Kent J. , Imasato Kazuki , Cojocaru‐Mirédin Oana , Wuttig Matthias , Gault Baptiste , Yu Yuan , Snyder G. Jeffrey 
Published: May 2021

AbstractThe poor carrier mobility of polycrystalline Mg3Sb2 at low temperatures strongly degrades the thermoelectric performance. Ionized impurities are initially thought to dominate charge carrier scattering at low temperatures. Accordingly, the increased electrical conductivity by replacing Mg with metals such as Nb is also attributed to reduced ionized impurity scattering. Recent experimental and theoretical studies challenge this view and favor the grain boundary (GB) scattering mechanism. A reduction of GB scattering improves the low‐temperature performance of Mg3(Sb, Bi)2 alloys. However, it is still elusive how these metal additions reduce the GB resistivity. In this study, Nb‐free and Nb‐added Mg3Sb2 are studied through diffraction, X‐ray absorption spectroscopy, solid‐state nuclear magnetic resonance spectroscopy, and atom probe tomography. It is shown that Nb does not enter the Mg3Sb2 matrix and remains in the metallic state. Besides, Nb diffuses along the GB forming a wetting layer, which modifies the interfacial energy and accelerates grain growth. The GB resistivity appears to be reduced by Nb‐enrichment, as evidenced by modeling the electrical transport properties. This study not only confirms the GB scattering in Mg3Sb2 but also reveals the hitherto hidden role of metallic additives on enhancing grain growth and reducing the GB resistivity.
Reversible and Tunable Second‐Order Nonlinear Optical Susceptibility in PZT Thin Films for Integrated Optics
Authors: Feutmba Gilles F. , Hermans Artur , George John P. , Rijckaert Hannes , Ansari Irfan , Van Thourhout Dries , Beeckman Jeroen 
Published: May 2021

AbstractSecond‐order nonlinear optical processes enable a wide range of applications used in research and industry. The majority of available second‐order nonlinear devices however relies on bulk nonlinear crystals with low second‐order nonlinearity. By exploiting the advancements made in integrated optics, materials with large second‐order nonlinearity can enable efficient and small‐sized on‐chip nonlinear devices at low cost. Unfortunately, silicon and silicon nitride, mostly used for photonics integrated circuits exhibit negligible second‐order nonlinearity (χ(2)) and alternate materials have to be investigated. Lead zirconate titanate (PZT) thin films with high second‐order nonlinearity stand as a good candidate for on‐chip nonlinearity. An electric‐field induced tuning of χ(2) is demonstrated here in PZT thin films grown on glass substrates with a tuning efficiency of 3.35 pm V−2. Strong second‐harmonic generation is recorded and a very high dominant tensor component of 128 pm V−1 is reported. The χ(2) of the PZT thin films can be reversed by poling with a DC electric field at room temperature. This opens avenues for highly efficient and tunable on‐chip nonlinear devices.