bluuebunny/crossref_metadata_2025 huggingface dataset:
Late Onset Alzheimer Dementia in Patients with Genotype E3/E4: A Case Report
Authors: Laksmidewi Anak Agung Ayu Putri , Vania Rau Chiquita Putri
Published: February 2021

BACKGROUND: Dementia is one of the leading causes of disability and dependence in elderly worldwide. Epidemiological statistics indicate that data show that at about 60–80%, Alzheimer’s is the most common type of dementia. Alzheimer’s is also the third-most prominent cause of death in elderly.
CASE REPORT: A 72-years-old male patient, complained by the family often forgets about things that have just been done for 3 years ago. According to the family, patient also often discussing the same things repeatedly. Patients tend not to have the initiative to start his daily activities. The family admitted that patient also became often angry and felt suspicious for the last 2 years. From the mini mental state examination showed disturbances in time orientation and recall; from Montreal Cognitive Assessment Ina found disturbances in visuospatial, fluency, abstraction, delayed memory, and time orientation; accompanied by activities of daily living (ADL) and instrumental ADL disorders. Patient also performed a molecular examination of the apolipoprotein E (APOE) genotype and the genotype E3/E4 was detected.
CONCLUSION: The function of the APOE gene, in particular APOE4, is the most emphasized genetic relationship in late onset Alzheimer’s disease. It is proposed that blocking the action of APOE4 can delay or stop Alzheimer’s disease progression.
La evaluación de la escritura creativa en el contexto universitario
Authors: Vega Rodríguez Pilar
Published: February 2021

Existe una larga tradición sobre las rúbricas pedagógicas de la escritura, principalmente referida a los niveles educativos no universitarios y con aplicación a la competencia lingüística en la lengua nativa o en una segunda lengua. En este trabajo se revisan los resultados de investigación referidos a la evaluación de la escritura creativa en niveles preuniversitarios y universitarios en contextos generales (no particularizados en zonas o culturas, sobre todo teniendo en cuenta la inexistencia de este tipo de bibliografía en lengua española), en cuanto corresponden al desarrollo de competencias en la lengua nativa, más allá de su empleo en el desarrollo del pensamiento crítico o en determinados ámbitos pedagógicos, y se ofrece una aproximación a los estándares de valoración del progreso de los estudiantes en esta disciplina.
Formas breves y escritura creativa: una puerta abierta a la imaginación
Authors: Orozco Vera María Jesús
Published: February 2021

En las últimas décadas la escritura creativa ocupa un lugar relevante. Esta demanda socio-cultural se manifiesta en el auge de talleres y de másteres especializados. Escribir con corrección y originalidad constituye, sin duda, una meta atractiva y ambiciosa. En ella se implican profesores y alumnos en un proceso de enseñanza-aprendizaje donde las formas breves muestran un campo de experimentación singular. Así el microrrelato y el teatro mínimo constituyen modelos literarios que muestran, en sus formatos minimalistas, un amplio abanico de posibilidades creativas. Los microrrelatos fronterizos constituyen, sobre todo, un espacio de experimentación de gran interés, por su hibridación con el periodismo y con la poesía. También las minipiezas pueden alcanzar cierto perfil mestizo, como las pulgas dramáticas de Moreno Arenas, el teatro fronterizo o teatro menor de Sanchis Sinisterra o el microteatro lírico de Antonia Bueno. Las formas breves permiten también trazar un puente hacia las nuevas tecnologías –twitteratura, literatura SMS-.
Hiperficción constructiva en el tercer entorno
Authors: Broullón-Lozano Manuel A. , Romero Santos José Manuel
Published: February 2021

Los modelos de escritura están experimentando grandes transformaciones como consecuencia de la revolución tecnológica contemporánea. Aunque los cibertextos y los hipertextos no son realidades exclusivas de la cultura digital, pues se dan en contextos culturales precedentes, aportan formas de pensamiento alternativas, que pasan por implicaciones epistemológicas –el pensamiento en red–, estéticas –reformulación de la autoría– y éticas –exigen un compromiso por parte del receptor. En este trabajo se abordará dicha coyuntura comparando las escrituras literarias Hypertext Hotel (1992) y Leyenda mayor de Ian Curtis (2017) con las escrituras audiovisuales +101 (2012) y Quién lo impide (2018) con el objetivo de comprender las transformaciones que suponen tanto en la experiencia estética como en el campo cultural digital. Para ello, se empleará una metodología comparatista que tenga en cuenta las concomitancias entre las dos series de escrituras.
Le temps des banquets
Authors: Robert Vincent
Published: February 2021

On s’est beaucoup moqué des banquets politiques, de « cette éloquence d’automne semée autour de tables bourgeoises et arrosée de vins du cru » (Lamennais). Comment prendre au sérieux en effet ces agapes, à nos yeux si prosaïques en pleine exaltation romantique, mais aussi ridiculement effusives dans une époque qui vouait un culte à la rationalité politique ? Et pourtant, aujourd’hui encore, chacun sait que la cause immédiate de la révolution de Février 1848 fut l’interdiction par Guizot d’un banquet réformiste, celui du XIIe arrondissement de la capitale. Bon nombre de contemporains en restèrent perplexes : comme nous, ils n’arrivaient pas à comprendre comment une décision apparemment anodine avait pu avoir de telles conséquences.Aussi fallait-il reconstituer une histoire qui n’a jamais été écrite, celle d’une forme disparue du répertoire politique. Le banquet n’est si étrange à nos yeux que parce que nous avons indûment valorisé Gavroche et Tocqueville, la barri­cade et le parlement. Décrire les banquets, pour d’abord mieux comprendre la sociabilité du premier xixe siècle, et reconstituer la culture politique de toute une génération, qui savait jouer des symboles et de l’implicite, et qui, après la Révolution et le despotisme napoléonien, cherchait sa voie dans une période décisive pour l’apprentissage de la liberté et de la démocratie. Puis faire toute sa place à un imaginaire dont nous avons oublié la richesse et les multiples enjeux. C’est, en définitive, s’interroger sur la nature même du lien politique, au-delà des discours et des institutions.
Les manifestations de rue en France
Authors: Tartakowsky Danielle
Published: February 2021

La manifestation de rue est une pratique minoritaire, antinomique au système parlementaire, longtemps dépourvue de tout statut juridique et qui ne doit qu’au vocable populaire de « manif » de s’être tardivement dotée d’une dénomination non polysémique. Et pourtant, plus de 15 000 manifestations recensées en France métropolitaine cinquante années durant, une assise sociale, politique et géographique potentiellement sans limite, des périodes de basses eaux mais jamais de disparition prolongée, pas même durant la guerre ou sous l’Occupation et une incontournable donnée de l’histoire politique et sociale contemporaine. C’est de ce paradoxe que cette histoire des manifestations de rue tente de rendre compte.

Il s’agit de s’interroger sur la permanence du phénomène, son poids, son extension politique, sociale et géographique et leur pourquoi ; sur ce qui range la manifestation au nombre des causes pour la défense desquelles se mènent, parfois, des batailles. Que signifie le fait de privilégier parfois pareille forme d’action quand le droit de grève et le suffrage universel peuvent (et doivent), en droit, suffire à tout ? Comment, pourquoi et avec quel résultat cette pratique qui est constitutivement la négation du système parlementaire finit-elle par s’imposer ? Comment le régime politique réussit-il à l’acclimater ? Avec quelles conséquences ?
Monarchie et modernité
Authors: Bourreau René
Published: February 2021

Associant la connaissance subjective de son département d’origine à la connaissance objective de l’enseignant-chercheur universitaire, l’auteur nous fait découvrir avec bonheur le cheminement de la députation ligérienne durant la période que dessine formellement la IIIe République. Il s’attache particulièrement à caractériser, souvent à l’aide d’esquisses biographiques, les représentations qui sont celles de la noblesse « restitutionniste ». Entendons par là : un groupe dominant dans la sphère politique de la ruralité catholique nantaise, qui ne vise pas seulement à restaurer l’institution monarchique, mais plus généralement et de plus en plus intensément, à faire partager ses propres valeurs.

Le présent ouvrage, scientifique et néanmoins fort lisible, devrait contri­buer à la clarification, à la « compréhension » du destin de l’ordre social nobiliaire auquel s’est aujourd’hui substitué celui de la classe notabiliaire. C’est une manière originale d’avancer dans le questionnement de ce qui n’est souvent qu’une pré-notion : la modernisation.

L’auteur continue d’explorer cette problématique selon laquelle la noblesse, trop vite réduite à son caractère réactionnaire, peut encore actuellement, sur de nombreux points, contrebalancer la perte d’un pouvoir socio-politique très repérable par une influence socio-culturelle moins aisément observable.
Chrysalides. Volumes I et II
Authors: Sohn Anne-Marie
Published: February 2021

Cet ouvrage se propose d’observer les femmes dans leur vie privée, jonglant avec les tâches qui leur sont dévolues, s’efforçant de concilier profession et contraintes familiales. Il ne s’agit pas ici de peindre des hétaïres ou des grandes bourgeoises, des intellectuelles ou des féministes. Non, ce sont les femmes ordinaires, principalement issues des milieux populaires, ce sont les oubliées, les sans-grade de l’histoire qui sont sur la scène.

Femmes ordinaires donc mais qui ont su avec obstination, et par devers les élites, construire leur vie et aménager leur condition. L’émergence durant la IIIe République de l’individu féminin qui aspire au bonheur, à l’époux élu comme à la maternité choisie, voit les femmes récuser à leur manière les représentations normalisatrices qui vouent le deuxième sexe au domestique et le cantonnent dans une position subordonnée.

C’est dans le cadre des relations intimes entre parents et enfants, entre maris et femmes surtout, que se redéfinissent les identités. La ménagère, la mère et l’épouse sont donc scrutées dans leurs pratiques et leurs aspirations, et celles-ci toujours mises en regard des comportements masculins. De la rencontre des futurs aux prolégomènes amoureux, des noces au train train quotidien, de la lutte pour le pouvoir conjugal à l’épanouissement de la sensualité, et jusqu’à la rupture qu’osent infidèles et divorcées, ce livre décrit les trajectoires féminines dans leur diversité et tente de reconstruire la pluralité des histoires individuelles.
Dielectric and Piezoelectric Properties of 0.36BiScO3 - 0.64PbTiO3 Ceramic Doped with Calcium Fluoride
Authors: Shahzad Khurram , Shabbir Ghulam , Li Hui , Li Zhen Rong
Published: February 2021

BiScO3-xPbTiO3 (BS-PT) of perovskite type structure (with x~0.64) were prepared by solid state ceramic process with addition of calcium fluoride (CaF2) in different molar ratios (0.5, 1.0 and 4.0 mol%). The doped compositions were found to have different symmetry compared with parent material. The 0.5 mol% doped sample was found to possess enhanced rhombohedral phase as compared to other compositions while he Curie temperature (Tc) was not affected appreciably. Small dielectric peaks were observed, indicating phase transition, at temperature lower than Tc in all the samples except 4.0% doped composition. At room temperature doping reduced the loss factor. d33 and Pr reduced rapidly with doping. The characteristics of BS-PT ferroelectric ceramics became harder with the addition of CaF2.
Study of Thermal Behaviour of EPDM/SBR Blends and Carbon Nanocoatings Deposited by Sputtering
Authors: Alamgir Muhammad , Ghauri Faizan Ali , Khan Waheed Qamar , Rasheed Sajawal , Nawaz Muhammad Sarfraz , Riaz Amir
Published: February 2021

In this study, the effect of SBR concentration (10 Phr, 20 Phr & 30 Phr ) on the thermal behavior of EPDM/SBR blends was studied. Thermogravimetric analysis (TGA) was used to check weight loss of samples as function of temperature by heating upto 600°C. X-ray diffraction (XRD) was performed to determine quality and % crystallinity of the elastomer blends. It was seen that % crystallinity improved with an increase in the content of SBR in EPDM/SBR blends. TGA revealed that the thermal stability of EPDM/SBR blends has improved by 17% than neat EPDM. Carbon nano-coatings produced by sputtering have no beneficial influence on thermal behaviour of elastomers.
Graphene Effect on Mechanical Properties of Sandwich Panel for Aerospace Structures
Authors: Naseer Zainab , Khan Zaffar
Published: February 2021

This research examines the mechanical properties of graphene-based polymer composites and Nomex honeycomb sandwich using a new strain sensing technique. Sandwich panels are fabricated individually with glass fibre reinforced polymers (GFRP) and face-sheets having different filler ratios of graphene nanoparticles (GNPs). These graphene nanoparticles are oxidized with (UV-O3) ozone to get graphene oxide (GO) which in turn improves resin matrix interfacial strength. Filler ratios of GO 0.0%, 0.2%, 0.6% and 1.0% by weight of poly-epoxy are fabricated for the face-sheets of composite sandwich panels. Graphene-based strain sensors are synthesized having a concentration of GNPs 5% by weight of polystyrene (PS). The strain sensors are pasted on the sandwich panels and four-point bending of the sandwich beams is performed to predict its flexural strength. The response of composite under different filler ratios of graphene oxide on mechanical properties is inspected during mechanical testing of sandwich panels and the results of (PS-GNPs) strain sensors will be compared with the strains produced during mechanical testing.
Synthesis and Characterization of Graphene Sheets from Graphite through Electrochemical Exfoliation and Microwave Reduction
Authors: Wazir Arshad , Kundi Imran Waseem , Khan Wahib Noor , Manan Abdul , Querashi Imdadullah , Yaqoob Khurram
Published: February 2021

Graphene as a wonder material has received great attention and importance due to its fascinating properties. Here in this study, we also demonstrate a simple two step process to prepare graphene sheets (GSs) from the electrochemical exfoliated graphene oxide (EE-GO) followed by microwave irradiation reduction. The properties and structure of the resulted product samples were studied by Ultraviolet spectroscopy (UV), Fourier-transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray (EDX or EDS), Raman spectroscopy and Atomic force microscopy (AFM) for validation of their distinguishing characteristics. UV spectra of microwave irradiation reduced graphene oxide (MI-RGO) and EE-GO exhibited an intense and sharp absorption peak concentrated at wavelengths of 236 and 266nm, respectively. The elimination of oxygen functionalities present in the EE-GO plane was illustrated by FTIR as a result of microwave irradiation treatment. The relative layer structures of MI-RGO and EE-GO were confirmed by XRD. Similarly, the Raman spectra revealed the difference in between the EE-GO and MI-RGO characteristic reflection bands. The thin, crumpled and curved type morphology of the obtained graphene sheets (GSs) was also displayed by SEM while the composition of a few layer graphene sheets with atomic mass percents of carbon (75%) and oxygen (25%) was established by EDX. The Synthesis procedure is simple, rapid and eco-friendly with high yield.
Preparation of Al2O3 Whiskers from AACH Using Hydrothermal Method and its Use for the Removal of Lead Ions by Adsorption
Authors: Ameer Asma , Ul Hassan Syed Mujtaba , Husnain Syed M. , Ahmad Jamil , Shahzad Faisal , Iqbal Zafar , Mehmood Mazhar
Published: February 2021

This work explores the potential of adsorption of Pb2+ by hydrothermally synthesized alumina. In comparison to other heavy ion removal techniques, adsorption is preferred in the current study as it has the edge of ease of operation and environment friendly characteristics. Synthesis of high surface area alumina whiskers was achieved by hydrothermal route which were subsequently employed for the active adsorption of lead ions. AACH (Ammonium Aluminum Carbonate Hydroxide), used as precursor for alumina, was calcined at three different temperatures i.e. 700, 900 and 1100 °C to form alumina whiskers. These whiskers were characterized by XRD, SEM, BET and FTIR. Various adsorption parameters such as contact time, pH, initial metal concentration were studied for lead ions. Maximal removal efficiency was obtained for the specimen having pH 4 and calcined at 700 °C for 60 minutes. Kinetic data was best described by pseudo second order model, whereas the adsorption equilibrium data obeyed the Langmuir adsorption isotherm model.
Non Precious Metal Catalysts: A Fuel Cell and ORR Study of Thermally Synthesized Nickel and Platinum Mixed Nickel Nanotubes for PEMFC
Authors: Shahbaz Ahmad , Afaf Ali , Tahir Nawaz , Ullah Abid , Saim Saher
Published: February 2021

A highly active Platinum Group Metal (PGM) and non-PGM electrocatalysts with thermally extruded nanotubes have been prepared for Proton Exchange Membrane (PEM) fuel cell by sintering Nickel zeolitic imidazole framework (Ni-ZIF). Preeminent electro-catalytic activities have been observed through single fuel cell tests and rotating disk electrode (RDE). This study involves the comparison of Oxygen Reduction Reaction (ORR) activities and fuel cell (FC) test station performance of two catalyst Nickel and Platinum mixed Nickel nanotubes (Ni NT, Ni/Pt NT) respectively. The acidic cells with corresponding Ni and Ni/Pt catalysts delivers peak power densities of 325 mWcm-2 and 455 mWcm-2 at 75 °C inside fuel cell. Our results indicate that, the synthesized Nickel nanotubes has profound effect on catalytic performance of both PGM and non-PGM electro catalysts.
Mechanical Behavior of Friction Stir Welded AA-6061 Thick Plates in Different Heat Treatment Conditions
Authors: Ahmed Talha , Muhammad Wali , Mushtaq Zaheer , Bhatty Mustasim Billah , Zaigham Hamid
Published: February 2021

In this study, mechanical properties of friction stir welded Aluminum Alloy (AA) 6061 in three different heat treatment conditions i.e. Annealed (O), Artificially aged (T6) and Post Weld Heat Treated (PWHT) were compared. Plates were welded in a butt joint form. Parameters were optimized and joints were fabricated using tool rotational speed and travel speed of 500 rpm and 350 mm/min respectively. Two sets of plates were welded in O condition and out of which one was, later, subjected to post weld artificial aging treatment. Third set was welded in T6 condition. The welds were characterized by macro and microstructure analysis, microhardness measurement and mechanical testing. SEM fractography of the tensile fracture surfaces was also performed. Comparatively better mechanical properties were achieved in the plate with PWHT condition.
Influence of Mn and TiB2 on the Microstructural Evolution of the Primary α-Al Grains and Fe Containing Intermetallic in the Wrought Al-Mg-Si Alloy
Authors: Khan Mir Hamza , Li Zushu , Kotadia Hiren , Das Amit
Published: February 2021

The most popular aluminium alloy used for the automotive applications is the wrought-Al alloy, where its popularity arises from its intrinsic characteristics such as, excellent formability, crash resistance, corrosion resistance and excellent specific strength. In the coming decades the use of aluminium alloys is expected to increase within automotive and aerospace industries, where this will source for an upsurge in Al recycling. Problems arise during Al recycling, where there is a steady build-up of Fe content, as this is recognised as being an impurity element. Fe has very little solubility in Al in its solid state and precipitation of these Fe intermetallics (IMC), in the Al matrix decrease mechanical properties, due to the Fe IMC brittle nature. These Fe-rich IMC also have very little cohesion to the Al matrix and can separate from the Al matrix resulting in the development of voids, where the initiation of microcracks becomes ostensible when subjected to thermomechanical processing. In order to curtail the damaging effect of the Fe IMC it so of importance to alter the nucleation and growth characteristic of the Fe rich IMC during solidification. Addition of trace elements and the manipulation of cooling rates have shown to be an effective technique to alter the Fe IMC morphology. In order observe the morphological evolution of the Fe IMC, various experiments were conducted using Al-1Si-1Mg-1Fe alloy with the addition of Mn and TiB2-based commercial grain refiner. Microstructural analysis of the primary α-Al and Fe IMC are observed and the morphological evolution of the Fe IMC is analysed with respects to the addition of Mn and TiB2. How the addition of these trace elements influence the growth characteristics and chemistry of the Al melt is also presented in this work.
Optimization of Maximum Tool Travel Speed for Friction Stir Welded AA-2014-T6 without Compromising the Mechanical Properties
Authors: Ahmed Talha , Muhammad Wali , Bhatty Mustasim Billah , Zillohu Ahnaf Usman , Zaigham Hamid
Published: February 2021

In this study optimization of maximum travel speed that can be achieved for Friction Stir Welding of Aluminum Alloy 2014-T6 without compromising the mechanical properties was carried out. Joints were made at different travel speeds of 200, 300, 400, 500 and 600 mm/min with constant tool rotational speed of 800 rpm and tool tilt angle of 2.The samples were characterized by stereo microscopy, optical microscopy, scanning electron microscopy, Vickers microhardness testing and tensile testing. Microstructural features of as-welded samples revealed refined equiaxed grains in nugget zone and grain growth in the heat effected zone. Tensile test results showed that the tensile strength was maximum at travel speed of 500 mm/min but then decreased after further increasing the travel speed. Hardness in the nugget zones of all welds was lower than that of base material. Fractographic analysis exhibited significant variations in fracture surfaces of tensile samples. A relationship between the welding parameters and resultant heat inputs was also discussed.
Crack Repairing of Aluminum Alloy 6061 by Reinforcement of Al2O3 and B4C Particles Using Friction Stir Processing
Authors: Masroor Zunair , Rauf Ahsan Abdul , Mustafa Faisal , Husain Syed Wilayat
Published: February 2021

Crack repairing of aluminum alloys is done using conventional welding techniques or mechanical methods, which results in the redundancy of mechanical properties due to defects formation. Friction Stir Welding/Processing (FSW/FSP) is a solid-state joining technique which is used to join various different similar and dissimilar metals, along with the fabrication of surface composites to cater the mentioned problem. The objective of this study is to repair the crack produced in 6061 aluminum alloy by the reinforcement of ceramic particles, Al2O3 and B4C, to further increase the efficiency of the joint along the crack line. Weld parameters, equipment used and the processing conditions are emphasized. The mechanical testing and the characterization of the weld as well as base metal was done and compared using tensile testing, micro hardness test and microstructural analysis. X-Ray Diffraction (XRD) was performed for crystallinity and intermetallic study. The dispersion of the particles was investigated using Field Emission Scanning Electron Microscope (FESEM). The crack in the Al-6061 was effectively repaired using FSP. The reinforced samples showed improved mechanical properties as compared to non-reinforced ones.
Solid State Conversion: Microstructuring of Crystalline Al2O3 (Sapphire) by Annealing of Patterned Aluminium Films
Authors: Akhtar Naureen , Askeland Simen Hjellvik , Holst Bodil
Published: February 2021

Surface structuring on the nano/micro level is important for a huge range of areas. A critical bottle neck for many industrial applications is upscaling; that is to say it must be possible to do the structuring in a comparatively simple and inexpensive manner. However, this is a challenge for many industrially important materials, including sapphire. A few years ago, solid state conversion was introduced as a relatively simply nanoscale structuring method for sapphire. Here we show that the method, by careful choice of parameters, can be extended to work also on the micron scale. We show that a microstructured aluminium film deposited on a Al2O3 (0001) surface is converted into a crystalline Al2O3 surface, when thermally annealed in air, using optimized parameters.
Effect of Second Phase Particles on Solid Particles Erosion of Air Plasma Sprayed Yttria Stabilized Zirconia
Authors: Ejaz Noveed , Ali Liaqat , Mansoor Muhammad
Published: February 2021

Yttria stabilized zirconia (YSZ) based composite topcoats were prepared with three advanced ceramic materials as second phase component; CaZrO3, (La0.75Nd0.25)2Zr2O7 and Nd2Ce2O7. The solid particles erosion (SPE) testing of the air plasma sprayed composite topcoats was carried out at room temperature and 900 °C to study the effects of second phase on erosion behavior. The erodent was angular fused alumina of 40-45 mm size. The erosion mechanism was followed in all topcoats with cracking and fracturing of the plasma sprayed splats due to erodent particles impact and impingement, whereas micro-ploughing was observed after 900 °C SPE testing as an additional feature. The hardness and intrinsic properties of second phase component in the composite topcoats played a crucial role in improving the erosion rate (ER) at ambient as well as 900 °C. The Nd2Ce2O7/YSZ topcoat show lower ER due to combatively higher hardness of Nd2Ce2O7 and good interfacial bonding with YSZ. The overall lowering of ER at 900 °C as compared to that of at ambient conditions was ascribed to the anelastic mechanical response of the ceramic topcoats due to thermal cycling involved in the SPE testing at high temperature.
Microstructural Evolution upon 10-wt% Mo Alloying and Laser Surface Melting of M2 High Speed Steels Hardfacings
Authors: Dilawary Shaikh Asad Ali , Motallebzadeh Amir , Houdková Šárka , Çimenoğlu H.
Published: February 2021

The article aims to comprehend the microstructural changes, in Plasma Transfer Arc (PTA) deposited M2 high speed steel (HSS) hardfacings upon incorporation of 10 wt% Mo alloying during deposition followed by laser surface melting. PTA deposited hardfacings were produced over 4140 steel. Then Mo alloyed and unalloyed PTA deposits were subjected to laser surface melting (LSM) process. A comprehensive microstructural characterization for all the resultant structures was carried out. Optical metallography using appropriate etching reagents and SEM microscopy in conjunction with XRD techniques were employed to ascertain the matrix structure and carbides morphology. The PTA microstructure was close to equilibrium structure of M2 HSS containing mixture of ferrite/austenite/martensite along with MC, M2C and M6C type carbides. While the LSM of M2 HSS caused higher fraction of martensite and finer grains in the structure resulting in increment in hardness. 10-wt% Mo addition changes the carbides from MC and rod like M2C to fibrous M2C and fishbone like M6C carbides. The LSM of Mo alloyed M2 HSS PTA deposits led to an overall decrease in the fraction of M6C carbides and fibrous M2C carbides accompanied by a decrease in hardness.
Thermal Characterization of Various Reduced Derived Fuel Materials for Energy Applications
Authors: Qureshi Tayyab , Hussain Muhammad Asif , Iqbal Tanveer , Ul Haq Ehsan , Tabish Asif Nadeem , Siddiqi Muhammad Hamid
Published: February 2021

The quest to research the new engineering materials for energy applications is increasing day by day due to decrease in fossil fuel materials. Moreover, the management of municipal solid waste (MSW) by converting it to the energy is need of our society to address the energy shortage as well as environmental issues. Refused derived fuel (RDF) material is one of the energy products of MSW, whose reliability and quality with respect to the energy is analyzed in this work. Three different RDF materials (RDF-A, RDF-B and RDF-C) have been characterized by thermal analysis techniques to suggest best RDF based on energy efficiency. The results showed that the RDF-A contains higher amounts of carbon (52.44%) and hydrogen (4.184%) contents and good calorific value (5278 kcal/kg), which leads to a better fuel quality. TGA analysis revealed that with the increase in volatile matter fraction of RDF materials, the retention time under combustion atmosphere has also been increased accordingly. In the light of all results RDF-A was suggested to be a good candidate for energy applications and can be used as fuel for various combustion reactions.
Surface Modification of Sputtered Carbon Supercapacitor Electrode by Hydrogen Annealing
Authors: Iqbal Muhammad Uzair , Zaman Noor , Shahid Muhammad , Hussain Azhar , Karim Muhammad Ramzan Abdul
Published: February 2021

In the applications of renewable energy; use of energy in the electric vehicles and many other electronic devices such as mobile devices and computers; electrical energy storage is essential. Batteries are used to store electrical energy but have low power density and lower cycle life. Using extremely porous electrode materials for supercapacitors, based on quick ion transport, are specialized to provide high power density, long stability and effective energy storage. Using graphene-based electrode is the best way to boost the energy density of supercapacitor. Graphene synthesized by chemical exfoliation, ultrasonic exfoliation and solution based chemical reduction suffers agglomerations that tends to restack the graphene sheets. In the present work, we studied the option of hydrogen gas annealing to obtain graphene from amorphous carbon film, coated on Cu substrate using sputtering. For electrochemical assessment, in situ developed film was compared with graphene applied from other methods of graphene synthesis. Atomic force microscopy (AFM) results revealed that annealed carbon sputtered electrode has high route mean square (RMS) roughness i.e 181.5 nm, most probably because of graphene formation. Cyclic voltammogram (CV) results show less area curve for annealed electrode which depicts high active area for charge storage and enhanced conductivity due to deposited graphene layer.
Temperature and Electric Field Dependent Phase Transformations in [001] PMN-PT Single Crystal
Authors: Shabbir Ghulam , Qureshi Ahmad H.
Published: February 2021

The capacitance of (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) [001]-oriented single crystal was examined as a function of temperature and applied external dc electric field. The phase transition temperatures under the applied electric field were measured upon cooling the crystal (zero-field heating field-cooling condition) from paraelectric cubic phase. From these data, temperature versus electric field phase diagram of PMN-xPT crystal have been constructed and discussed.
Effect of Nano-Silica Volume Reinforcement on the Microstructure, Mechanical, Phase Distribution and Electrochemical Behavior of Pre-Alloyed Titanium-Nickel (Ti-Ni) Powder
Authors: Raza Syed Abbas , Khan Muhammad Imran , Ahmad Mairaj , Tahir Danish , Iltaf Asim , Naqvi Rida Batool
Published: February 2021

Titanium-Nickel pre-alloyed powder was reinforced with Nano-Silica in 2%, 4% , 6% and 8 wt. % due to effectiveness of Nanoscale ceramic Reinforcement in improving the properties of Metals and Alloys. The compositions of the Pre-Alloyed powders and Nano Silica Approximately 50 nm in diameter and spherical in shape were weighed and mixed in Planetary Ball Mill followed by compaction at 50 MPa using a Uniaxial Compaction machine The green pellets obtained were sintered in Argon Environment for 5 hrs and allowed to furnace cool. The pellets were then sectioned through their cross-section for slices 3 mm thick followed by Cold-mounting and Soldering followed by cold mounting additionally. The Samples were analyzed via X-Ray Diffraction (XRD) for phase distribution as a function of variation in nano-Silica reinforcements and Microstructural analysis was performed via Optical Microscope. The effect of Volume percentage on the densification was determined via Archimedes principle and Micro-Vickers hardness was used for mechanical Evaluation. The Electrochemical Properties were evaluated using Potentio-Dynamic Polarization and Electrochemical Impedance Spectroscopy (EIS) in neutral salt solution (3.5% NaCl). The results indicated increasing dissolution of the TiNi phase into intermetallic Titanium-rich and Ni-rich phases in the matrix and hardening due to the Nano-Silica effect of Grain Boundary impingement and phase dissolution of Equiatomic phase and mixed behavior in Corrosion properties as determined by the electrochemical techniques whereas densification decreased due to poor plasticity of Nano-Silica and hinderance in diffusion during the sintering process.
Synthesis and Characterization of Mnbi Magnetic Alloy via Two Different Processing Routes
Authors: Mazhar Hifsa , Hussain Wilayat
Published: February 2021

Manganese bismuth alloy has gained importance due to its rare earth free elements, positive temperature coefficient and unique magnetic properties. Low temperature phase (LTP) MnBi was successfully prepared by arc melting with subsequent heat treatments and melt spinning technique followed by heat treatment for different durations. LTP MnBi formation was confirmed using XRD analysis and microstructural characterization of the samples was done using field emission scanning electron microscope. MnBi with greater LTP amount was formed by melt spinning route when compared with its counter arc melted one. Magnetic energy density of LTP MnBi formed by melt spinning technique with different heat treatment time was studied.
Soldering to Gold Thin Films Using Indium Rich Silver Eutectic Alloys
Authors: Mansoor Muhammad , Zaigham Hamid , Ghauri Khalid Mehmood , Ali Liaqat
Published: February 2021

Performance of the semiconductor devices is solicited by reliable metallic electrical connections. Any bad electrical connection may one of the major sources of noise and low mechanical strength, hence reducing the performance and life of the device. Apart from the successful synthesis or development of semiconductor devices or solders; the technique to carry out soldering process plays a vital role to attain reliable and reproducible electrical connections. This paper demonstrates the soldering process on gold thin films using In-3.0%Ag eutectic soldering alloys considering the three fundamental aspects of the process i.e. scavenging, wetting and aging. Scavenging and wetting behaviors of the solder were evaluated at various temperatures and different fluxes, respectively. Effect of aging was evaluated by shear testing after aging for various durations. It was observed that using the soldering temperature somewhere between 160-190 °C with 20 wt.% salicylic acid flux is favorable for better wetting and scavenging characteristics. A post solder aging (at 95 °C for 12 hours) seamed to facilitate improvement in mechanical strengths.
Tuning the Ablation, Thermal and Mechanical Characteristics of Phenolic Resin Reinforced EPDM Ultra-High Temperature Insulation
Authors: Iqbal Sadia Sagar , Ahmad Tasawer Shahzad , Bashir Arshad , Bahadar Ali , Siddique Farzana
Published: February 2021

The present research reports the influences of variant phenolic resin concentrations on the thermo-mechanical and ablation characteristics of ethylene propylene diene monomer (EPDM) elastomer. Backface temperature acclivity (BTA), charring rates, and insulation indexes were executed for the fabricated composite specimens. It was noticed that BTA was enhanced while linear/radial/mass ablation rates were significantly diminished with increasing concentration of phenolic resin (PR) in base matrix (elastomeric polymer). The composite (30wt%PR/EPDM) has 25% high thermal endurance compared to virgin EPDM composite. Thermal conductivity was increased with increasing PR to EPDM ratio. PR incorporation has remarkably enhanced the ultimate tensile strength of the EPDM elastomer. An efficient improvement in elastomeric hardness was also observed with increasing PR contents in EPDM matrix. Scanning Electron Microscopy (SEM) results showed the porosity generation and polymer melting during ablation.
Burnout and Presenteeism among Healthcare Workers in Nigeria: Implications for Patient Care, Occupational Health and Workforce Productivity
Authors: Nwosu Arinze D.G. , Ossai Edmund , Onwuasoigwe Okechukwu , Ezeigweneme Maureen , Okpamen Jude
Published: February 2021

Background

Burnout and presenteeism are two emerging occupational health challenges which share same locus among healthcare workers, and the trend is rising. We aim to define the magnitude of burnout and presenteeism among frontline members of the health workforce and explore any correlation between the two in order to provide empirical data from our socioeconomic and geographical background.

Design and methods

We used self-administered questionnaire to conduct a cross-sectional study among the physicians and nurses in a regional trauma centre in Enugu, Eastern Nigeria; with the respondents selected by stratified random sampling. The Oldenburg burnout inventory and Stanford presenteeism scale were used to measure burnout and presenteeism respectively, while the 2-item patient-health questionnaire (PHQ-2) was used to screen for depression. The level of statistical significance was determined by a p value of <0.05.

Results

Among the healthcare workers surveyed (n=155); 34 (21.9%) were physicians, while 121 (78.1%) were nurses. Burnout prevalence was 69%. Burnout was associated with self-rated health status and length of years in professional service but not the occupation or depression screen status of the worker. Sixty-two healthcare workers (40%) screened positive for depression. A positive screen for depression was the only factor that had significant association with lower presenteeism scores (p=0.002). The mean presenteeism scores had strong negative correlation with both the exhaustion (p<0.001) and disengagement (p<0.001) domains of burnout.

Conclusion

Burnout is high among the healthcare workers and correlates with presenteeism scores. The mental health of the workforce greatly impaired their productivity.
Dulaglutide as an Effective Replacement for Prandial Insulin in Kidney Transplant Recipients with Type 2 Diabetes Mellitus: A Retrospective Review
Authors: Kim Hwi Seung , Lee Jiwoo , Jung Chang Hee , Park Joong-Yeol , Lee Woo Je
Published: February 2021

Dulaglutide, a weekly injectable glucagon-like peptide-1 receptor agonist, has demonstrated effectiveness when combined with basal insulin. We examined whether the efficacy of dulaglutide is comparable to that of prandial insulin in kidney transplant (KT) recipients with type 2 diabetes mellitus (T2DM) undergoing multiple daily insulin injection (MDI) therapy. Thirty-seven patients, who switched from MDI therapy to basal insulin and dulaglutide, were retrospectively analyzed. Changes in glycosylated hemoglobin (HbA1c) and fasting plasma glucose (FPG) levels, body weight, and basal insulin dose were evaluated over 6 months. Dulaglutide was comparable to three injections of prandial insulin in terms of glycemic control (HbA1c 7.1% vs. 7.0%; 95% confidence interval [CI], –0.53 to 0.28; P=0.53). The basal insulin and dulaglutide combination resulted in a reduction in FPG levels by 9.7 mg/dL (95% CI, 2.09 to 41.54; P=0.03), in body weight by 4.9 kg (95% CI, 2.87 to 6.98; P<0.001), and in basal insulin dose by 9.52 IU (95% CI, 5.80 to 3.23; P<0.001). Once-weekly dulaglutide may be an effective alternative for thrice-daily prandial insulin in KT recipients with T2DM currently receiving MDI therapy.
Protective effect of bone marrow mesenchymal stem cell-derived exosomes against the reproductive toxicity of cyclophosphamide is associated with the p38MAPK/ERK and AKT signaling pathways
Authors: Guo Xiao-Bin , Zhai Jia-Wen , Xia Hui , Yang Jian-Kun , Zhou Jun-Hao , Guo Wen-Bin , Yang Cheng , Xia Ming , Xue Kang-Yi , Liu Cun-Dong , Zhou Qi-Zhao
Published: February 2021

Spermatogenic dysfunction caused by cyclophosphamide (CP) chemotherapy has seriously influenced the life quality of patients. Unfortunately, treatments for CP-induced testicular spermatogenic dysfunction are limited, and the molecular mechanisms are not fully understood. For the first time, here, we explored the effects of bone marrow mesenchymal stem cell-derived exosomes (BMSC-exos) on CP-induced testicular spermatogenic dysfunction in vitro and in vivo. BMSC-exos could be taken up by spermatogonia (GC1-spg cells). CP-injured GC1-spg cells and BMSC-exos were cocultured at various doses, and then, cell proliferation was measured using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. In addition, photophosphorylation of extracellular-regulated kinase (ERK), p38 mitogen-activated protein kinase (p38MAPK), and protein kinase B (AKT) proteins was evaluated by western blotting as well as apoptosis in GC1-spg cells measured using flow cytometry. Treatment with BMSC-exos enhanced cell proliferation and reduced apoptosis of CP-injured GCI-spg cells. Phosphorylated levels of ERK, AKT, and p38MAPK proteins were reduced in CP-injured spermatogonia when co-treated with BMSC-exos, indicating that BMSC-exos acted against the reproductive toxicity of CP via the p38MAPK/ERK and AKT signaling pathways. In experiments in vivo, CP-treated rats received BMSC-exos by injection into the tail vein, and testis morphology was compared between treated and control groups. Histology showed that transfusion of BMSC-exos inhibited the pathological changes in CP-injured testes. Thus, BMSC-exos could counteract the reproductive toxicity of CP via the p38MAPK/ERK and AKT signaling pathways. The findings provide a potential treatment for CP-induced male spermatogenic dysfunction using BMSC-exos.
Pulmonary Hypertension - Glimpse from an Upper Window Can Help!
Authors: Mathen Pratheesh George , Krupa Jesu
Published: February 2021

Pulmonary hypertension (PH) is an increasingly common condition encountered by physicians and cardiologists. PH is a complex, multidisciplinary disorder characterized by elevated mean pulmonary artery pressures, which can be the hemodynamic and pathological culmination of a large variety of distinct underlying disorders. This makes an accurate etiological diagnosis challenging for the clinician. History and physical examination, although nonspecific, can point toward a particular diagnosis, gauge the severity of PH, and assist in identifying associated disorders. However, a well-performed echocardiographic examination can enable a physician to arrive at an accurate diagnosis. Here, we present an interesting case in which a careful systematic transesophageal echocardiographic assessment allowed us to reach an accurate diagnosis for the etiology of PH.
The association of plasma acyl ghrelin level with alcohol craving in early abstinent alcohol dependent patients
Authors: Sha L , Dey P , Khess CR , Khitiz KK
Published: February 2021

Background:

Craving plays an important role in maintenance of alcohol dependence. Earlier studies have analyzed the role of ghrelin in craving and their results have been heterogenous. Acyl ghrelin is its more active form as it crosses the blood brain barrier. Hence we aimed to examine the relationship between plasma acyl ghrelin and craving in Indian patients having alcohol dependence syndrome.

Methods:

The present study was a hospital-based prospective study. A total of 60 drug-naive patients of alcohol dependence and 30 healthy controls were included. After taking informed consent fasting blood samples were collected from them on day 1 and tested for plasma acyl ghrelin level. Fasting blood samples were repeated in all cases on day 14. During this time, we also assessed the patients' cravings by obsessive compulsive drinking scale, and alcohol craving questionnaire; and withdrawal by clinical institute withdrawal assessment for alcohol scale. These scales were repeated on day 14. Data analysis was done by SPSS version 25.0.

Results:

Plasma concentrations of acyl ghrelin increased significantly during early abstinence in patients from day 1 to day 14 (P < 0.0001). Pearson correlation test revealed a trend of positive correlation between plasma concentration of acyl ghrelin on day 14 and severity of craving on day 1.

Conclusion:

Our results suggest the plasma concentration of acyl ghrelin may be a predictor of severity of alcohol craving during early abstinence. Anti-craving drugs acting on acyl ghrelin level in brain may open an innovative avenue for optimum treatment of alcohol dependence.
Categorical Plücker Formula and Homological Projective Duality
Authors: Jiang Qingyuan , Leung Naichung Conan , Xie Ying
Published: February 2021

Kuznetsov’s homological projective duality (HPD) theory [K4] is one of the most active and powerful recent developments in the homological study of algebraic geometry. The fundamental theorem of HPD systematically compares derived categories of dual linear sections of a pair of HP-dual varieties

(X,X^{\natural})

.In this paper we generalize the fundamental theorem of HPD beyond linear sections. More precisely, we show that for any two pairs of HP-duals

(X,X^{\natural})

and

(T,T^{\natural})

which intersect properly, there exist semiorthogonal decompositions of the derived categories

D(X \cap T)

and

D(X^{\natural} \cap T^{\natural})

into primitive and ambient parts, and that there is an equivalence of primitive parts

^\mathrm {prim} D(X \cap T) \simeq D(X^{\natural} \cap T^{\natural})^{\mathrm prim}

.
Elision in Esahie
Authors: Owusu Ansah Victoria
Published: February 2021

One of the syllable structure changes that occur in rapid speech because of sounds influencing each other is elision. This paper provides an account of elision in Esahie, also known as Sehwi, a Kwa language spoken in the Western North region of Ghana. The paper discusses the processes involved in elision, and the context within which elision occurs in the language. The paper shows that sound segments, syllables and tones are affected by the elision process. It demonstrates that elision, though purely a phonological process, is influenced by morphological factors such as vowel juxtapositioning during compounding, and at word boundary. The evidence in this paper show that there is an interface between phonology and morphology when accounting for elision in Esahie. Data for this study were gathered from primary sources using ethnographic and stimuli methods.