bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibiotic susceptibility pattern and risk factors associated with Acinetobacter and Pseudomonas infection at a tertiary care hospital
Authors: Sherchan Jatan Bahadur
Published: September 2021

Background: Infection due to Acinetobacter spp. and Pseudomonas aeruginosa is a major worldwide concern these days. Antibiotic resistance and predisposing factors among the patients for acquiring such infection is a major challenge globally and in Nepal.
Objectives: To determine antimicrobial susceptibility pattern of Acinetobacter spp. and Pseudomonas aeruginosa isolates along with predisposing factors.
Methods: A total of 9,705 clinical samples were processed in this analytical cross-sectional study from December 2019 to November 2020. Antibiotic susceptibility pattern was determined following Clinical Laboratory Standard Institute guidelines. Patients’ information was obtained after informed consent.
Results: Acinetobacter spp. and Pseudomonas aeruginosa isolates were 92 (0.95%). Fifty-three (57.61%) samples were respiratory samples. Thirteen (20%) Pseudomonas aeruginosa and 18 (66.67%) Acinetobacter spp. were multidrug-resistant (MDR). Eight (12.31%) Pseudomonas aeruginosa strains and 13 (48.15%) Acinetobacter spp. strains were sensitive only to Colistin.   Twenty-two (95.65%) prolonged hospital stayers had MDR bacteria compared to only nine (13.04%) non-prolonged hospital stayers (p-value <0.001). Sixteen (94.12%) of diabetic patients had MDR bacteria isolates in comparison to only 15 (20%) of non-diabetic patients (p-value <0.001). Thirty-one (33.69%) were elderly patients (age ?65 years) and 61 (66.31%) were of age less than 65 years old. Seventeen (54.84%) of elderly patients had MDR isolates whereas only 14 (22.95%) of patients who are not elderly had MDR isolates (p-value =0.0047).
Conclusion: Acinetobacter spp. and Pseudomonas aeruginosa strain were isolated from various samples. For effective treatment of infection by such organisms detailed microbiological diagnosis and drug susceptibility testing is needed along with identification of predisposing factors.
Extra canal in permanent maxillary first molar in patients undergoing root canal treatment at a tertiary care dental hospital, Nepal
Authors: Gharti Archana , Joshi Neera , Prajapati Kranti , Wagle Sharada Devi , Shrestha Suraj
Published: September 2021

Background: Permanent maxillary first molar normally has three root canals but it can have extra root canals for which several studies were done in many parts of the globe. However, this type of study to explore extra canal is lagging in the context of Nepal.
Objectives: The objective was to determine the percentage of extra canal in permanent maxillary first molar in patients undergoing root canal treatment and to compare the same between male and female.
Methods: The descriptive cross-sectional study was conducted in the department of conservative dentistry and endodontics of People’s Dental College and Hospital from 20th December 2019 to 20th December 2020 after receiving ethical approval from Nepal Health Research Council on 18th December 2019 (ERB protocol No 888/2019) . One hundred and eighty permanent maxillary first molar teeth without root canal calcification were enrolled. Convenient sampling was done. Access opening was done and all canal orifices were located and recorded. Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 22.0 with frequency table. Chi-square test was used for inferential statistics.
Results: Out of 180 teeth, extra canals were present in 44(24.4%) having more numbers in male than in females. Extra canal was present in the mesiobuccal root.
Conclusion: Extra canal in the permanent maxillary first molar is present in Nepalese population with greater number in male than in female. Thus, exploration of the pulp chamber in search of an extra canal is necessary to prevent failure of root canal treatment.
L’impact de tâches communicatives de réalité virtuelle sur la volonté de communiquer à l’extérieur de la classe : perceptions d’apprenants de FLS à Montréal
Authors: Papin Kevin
Published: September 2021

Willingness to communicate (WTC) in a second language (L2) depends on both stable and situational factors and research indicates that language anxiety (LA) and self-perceived communicative competence (SPCC) are its two main antecedents. Although researchers have suggested that the development of WTC should be a priority of L2 teaching, more research is needed in this regard. This exploratory study aims at determining the impact of communicative tasks, performed in virtual reality (VR), on WTC outside the classroom. The 19 participants were university students learning French as a second language in Montreal (Canada). Mixed methodology was used to measure and probe their levels of WTC, LA and SPCC, as well as to shed light on the challenges they faced when trying to interact in French in Montreal. The results indicate that VR tasks have the potential to increase WTC, mainly through the increase of SPCC. The pedagogical implications are discussed.
Conflict, War and Revolution: The problem of politics in international political thought
Authors: Kelly Paul
Published: September 2021

Violence and war were ubiquitous features of politics long before the emergence of the modern state system. Since the late 18th century major revolutions across the world have further challenged the idea of the state as a final arbiter of international order. This book discusses ten major thinkers who have questioned and re-shaped how we think about politics, violence and relations between states – Thucydides, Augustine, Machiavelli, Hobbes, Locke, Rousseau, Clausewitz, Lenin and Mao, and Schmitt. Conflict, war and revolution have generally been seen in political thought as problems to be managed by stable domestic political communities. In different ways, all the paradigmatic thinkers here acknowledge them instead as inevitable dimensions of human experience, manifested through different ways of acting politically – while yet offering radically distinct answers about how they can be handled. This book dramatically broadens the canon of political thought by considering perspectives on the international system that challenge its historical inevitability and triumph. Each thinker is considered in a free-standing chapter rather than as a placeholder in a debate such as ‘realism versus idealism’. The book broadens international political thought debates by drawing on history, theology, and law as well as philosophy. And Paul Kelly introduces thinkers who challenge fundamentally the ways in which we should think about the nature and scope of political institutions and agents. In doing so the analysis illuminates a myriad of troubling contemporary conflicts with a crucial critical and historical perspective. This book is primarily intended for second year and upwards undergraduate students in general political theory and international theory, and advanced international relations students. Each chapter is also downloadable on its own for use in courses considering only some of the ten theorists covered. Written in an accessible way Conflict, War and Revolution will also interest advanced general readers with interests in the historical thought underpinnings of political ideas and today’s international politics. Detailed reading advice is provided, and advice on how to access open access versions of the key thinkers writing.
Implicación familiar en el bachillerato: una estrategia para favorecer la permanencia escolar
Authors: Infante Blanco Alejandra , Padilla González Laura Elena
Published: September 2021

La familia y la escuela se configuran como dos espacios formativos por naturaleza, se espera que ambos colaboren a lo largo de los procesos escolarizados. Es amplia la literatura que corrobora la importancia de la relación familia-escuela durante la educación básica, sin embargo, son menos las investigaciones que abordan la temática desde la educación media superior o superior. Este trabajo presenta el desarrollo del concepto de implicación familiar en la educación y deja ver su importancia en el logro académico de los estudiantes de bachillerato, asumiendo que la familia sigue siendo importante por la etapa evolutiva que transitan la adolescencia, y por su papel estratégico para promover la permanencia escolar en este tipo educativo. Se retoma el modelo de Epstein en la clasificación de niveles de implicación familiar, así como en las prácticas familiares y escolares que dan lugar al logro académico de los estudiantes. A partir de lo anterior, se analizan algunas estrategias identificadas en la literatura que pueden ser de utilidad para las preparatorias mexicanas en la implicación de las familias en uno de sus mayores retos:  la permanencia de los estudiantes en el bachillerato.
Cavitation Resistance of Coatings with a Metastable Austenite Structure
Authors: Korobov Yu.S. , Alwan H.L. , Filippov M.A. , Soboleva N.N. , Sirosh V.A. , Makarov A.V. , Estemirova S.Kh.
Published: September 2021

The effect of martensitic phase transformation on cavitation erosion resistance for a deposited layer prepared from a Fe-8Cr- C-1.5Al-Ti flux-cored wire of metastable steel was studied. A reference material of AISI 316L stainless steel was used as a substrate. Cavitation tests were performed using a modified ultrasonic tester. X-ray diffraction was used to examine the phase transformation before and after cavitation tests. Also, the eroded surfaces of specimens were investigated by optical microscope (OM), scanning electron microscope (SEM), and 3D optical profilometer. The cavitation results revealed that the deposited layer exhibited a resistance to cavitation erosion approximately 10 times higher than the AISI 316L steel due to the martensitic phase transformation occurring during the cavitation process. The phase transformation plays a main role to minimize the cavitation damage of specimen. This is due to the fact that it contributes to obstructing movement of dislocations and increasing the hardness as a result of the increased hardening on the surface.
Analytical and Numerical Modelling of Interfacial Stress Distribution of a Piezoresistive Coating Layer
Authors: Ogunbadejo Adekunle Sulaimon , McDonald André , Chandra Sanjeev
Published: September 2021

Thermally sprayed coatings can be used in structural health monitoring devices where the coatings can reveal defects in the real-time integrity of the component through changes in mechanical, thermal or modal properties during service. In this emerging application, the mechanical properties of the coating are strongly affected by the interfacial bond between the coating and the substrate. This paper presents an analytical study of the interfacial stress distribution based on piezoresistive-stress constitutive relation of a coating layer. Both a single layer coating- and a bilayer coating-substrate system were considered. An analytical solution of the interfacial stress was developed by solving a Fredholm-Volterra singular integro-differential equation of a coating-substrate model using Chebyshev polynomials. Numerical simulation was conducted to analyze the effects of geometric and effective material properties of the coating-substrate system on the interfacial stress distribution. It was found that the susceptibility of the piezoresistive layer to delamination primarily relies on thicknesses of the coating layers and the stiffness of the intermediary insulating layer and substrate.
Capturing the Influence of Jet Fluctuations on Particles in Plasma Spraying
Authors: Bobzin K. , Heinemann H. , O‘Brien A.
Published: September 2021

Instabilities and fluctuations of the plasma jet can have a significant influence on the particle in-flight temperatures and velocities, thus affecting the properties of plasma sprayed coatings. Presented in this paper is a novel method for capturing the effects particles are exposed to in the plasma spraying process. High-speed camera images of a plasma jet generated by a cascaded three cathode plasma generator (TriplexPro-210) are recorded for varying operating conditions. The images are processed using the inverse Abel transform. This transformation accounts for the fact that the images represent a 2-D projection and generates correct intensity values of the plasma jet images. These images are then combined with particle tracks resulting from CFD simulations of the plasma jet to match the particles path with the recorded plasma jet. This new method allows a precise description of the plasma intensity experienced by individual particles with a high temporal resolution. The results show a high sensitivity of the method, it can even detect the influence of the plasma jet originating from the cascaded triple arc plasma generator, which is considered as rather stable, on the particles.
Microstructure and Corrosion Properties of AlCoCrFeNi High-Entropy Alloy Coatings Prepared by HVAF and HVOF
Authors: Löbel Martin , Lindner Thomas , Mehner Thomas , Rymer Lisa-Marie , Lampke Thomas , Björklund Stefan , Joshi Shrikant
Published: September 2021

High-entropy alloys (HEAs) represent an innovative development approach for new alloy systems. These materials have been found to yield promising properties, such as high strength in combination with sufficient ductility as well as high wear and corrosion resistance. Especially for alloys with a body-centered cubic (bcc) structure, advantageous surface properties have been revealed. However, typical HEA systems contain high contents of expensive or scarce elements. Consequently, applying them as coatings where their use is limited to the surface represents an exciting pathway enabling economical exploitation of their superior properties. Nevertheless, processing conditions strongly influence the resulting microstructure and phase formation, which in turn has a considerable effect on the functional properties of HEAs. In the presented study, microstructural differences between high-velocity oxygen fuel (HVOF) and high-velocity air fuel (HVAF) sprayed coatings of the alloy AlCrFeCoNi are investigated. A metastable bcc structure is formed in both coating processes. Precipitation reactions are suppressed by the rapid solidification during atomization and by the relatively low thermal input during spraying. The coating resistance to corrosive media was investigated in detail, and an improved passivation behavior was observed in the HVAF coatings.
Electrical Properties of Half Heusler Coatings Depending on Spray Process
Authors: Darut Geoffrey , Portebois Axel , Vitu Ludovic , Planche Marie Pierre , Liao Hanlin , Misra Shantanu , Candolfi Christophe , Lenoir Bertrand
Published: September 2021

Microstructure and physicochemical properties of a thermally sprayed coating depend on the dynamics of the particles interacting with the spray jet. This is especially the case for electrical properties. In this study, different spraying processes were used to spray p-type and n-type half-Heusler powders. Thermoelectric powders, Hf20Zr75Ti05CoSb80Sn20 (p-type) and Hf60Zr40NiSn98Sb02 (n-type), were selected due to their interesting electrical properties. The spray processes were evaluated based on coating composition and mechanical property measurements. The only coatings of practical interest were those that were plasma sprayed and they were examined in detail to assess the effect of process parameters on coating properties.
The Influence of Diamond Addition to Ni-Al Powder on Oxidation Behavior of Ni-Al During Plasma Spraying for High Performance Oxide-Free Ni-Al Intermetallic Coating
Authors: Zhang Li , Wang Di , Liao Xian-Jin , Luo Xiao-Tao , Li Chang-Jiu
Published: September 2021

Ni-Al intermetallics have excellent corrosion and oxidation resistance, but their use in thermal spraying has been limited due to issues with in-flight oxidation. In this study, a novel approach is proposed to remove oxide from Ni-Al droplets in-flight by adding a deoxidizer (diamond) to the feedstock powder. A mixture of nickel, aluminum, and diamond powders was mechanically alloyed using a combination of cryogenic and planetary ball milling. The resulting Ni/Al/diamond composite powder was then plasma sprayed via the APS process, forming Ni-Al coatings on Inconel 738 substrates. Phase composition, microstructure, porosity, and microhardness of the coatings were characterized by X-ray diffraction, scanning electron microscopy, image analysis, and hardness testing, respectively. Oxygen content measurements showed that the coatings contained significantly less oxygen than coatings made from ordinary Ni/Al powders. In-flight particle temperatures were also measured and found to be higher than 2300 °C. The low oxygen content in the coatings is attributed to the in-situ deoxidizing effect of ultrahigh temperature droplets which are also oxide-free.
Exposure to Nanoparticles in Thermal Spraying — Vigilance Towards the Operator and the Outside Environment
Authors: Darut G. , Dieu S. , Meunier L. , Schnuriger B. , Vignes A. , Bihan O. Le , Morgeneyer M. , Lezzier F. , Devestel F. , Vion A. , Berguery C. , Roquette J.
Published: September 2021

This paper presents the results of an emission study on plasma spraying equipment and processes. Various measurements and samples were taken outside the spraying booth, at the operator level, and in the suction ducts upstream and downstream of the filtration equipment, creating a detailed profile of the aerosol emitted by the injection of NiAl powder in the plasma jet. The results show the existence of two families of particles, one ranging in size from 0.5 to 20 µm, the other of nanometric proportions. Concentrations of the larger particles were in the range of 600 cm-3 in the booth. As for submicron particles, concentrations of up to 107 cm-3 were observed but decreased significantly at the outlet of the filter system. The aerosol samples examined were dominated by a nanometric background of aggregates made up of oxidized nickel particles. Aggregates up to 100 nm in size, consisting of finer particles in the 5-20 nm size range, were found in high concentrations upstream of the filtration system. Great vigilance is thus required to protect equipment operators, an important part of which is placing dust collectors as close as possible to spraying booths connected by short, straight pipe runs.
Formation of Solid Solution and Metallic Nickel Phases During Suspension Plasma Spraying of Co Oxide and Ni Oxide
Authors: Jalilvand Vahid , Dolatabadi Ali , Moreau Christian , Mohammadkhani Saeed , Roué Lionel , Guay Daniel
Published: September 2021

The focus of this study is the formation of a solid solution and metallic nickel in the cobalt-nickel mixed oxide coatings during suspension plasma spray (SPS) deposition. The (Co,Ni)O solid solution is a potential material for inert anode applications in aluminum production. SPS coatings and in-flight collected particles are studied to gain further insight into the melting and mixing phenomena of the NiO and CoO powders as well as phase formation in the deposited coatings. Moreover, the role of suspension feedstock particle sizes on the microstructure of coatings is discussed. SEM, EDS and X-ray diffraction studies helped better understanding the formation of different crystalline phases within the as-sprayed coatings. It was found that the formation of metallic nickel is possible in the coatings. The results support the importance of substrate temperature on the formation of metallic Ni, so that keeping the substrate at low temperature results in an increase of the Ni content in the coatings. In this study, possible causes for the formation of metallic Ni during spraying are discussed.
Diffusion Simulation in SUS 430 Stainless Steel Interconnect with a MnCu Coating at 800°C
Authors: Yuan Kang , Geng Shujiang
Published: September 2021

(MnCu)3O4 spinel coatings are good candidates for Cr-positioning protection on stainless steel interconnect. The spinel coatings can be formed by sputtering MnCu followed by a hot oxidation treatment. To understand how the elements diffuse in the MnCu-steel system, a homogenization diffusion-couple model was built with consideration for Mn oxidation at the coating surface. According to the simulation, the diffusion of Fe from the steel substrate to the MnCu coating occurred while Cr was almost trapped under the MnCu coating. Cu-rich metallic phase formed under the Mn-oxide layer early in the process. The solid solubility of Cr in such Cu phase was very low which can function as a Cr blocker so that Cr external oxidation can be inhibited. The inward diffusion of Mn from the coating to the substrate was caused by the formation of a Mn concentration peak at the interface which, based on thermodynamic simulations, was probably due to the dissolution of Mn with Fe and Cr.
Fabrication of Cavitation Erosion Resistant Bronze Coatings by Thermal and Kinetic Spraying for Maritime Applications
Authors: Hauer M. , Gärtner F. , Krebs S. , Klassen T. , Watanabe M. , Kuroda S. , Krömmer W. , Henkel K.-M.
Published: September 2021

The present study compares needed prerequisites for the application of cavitation resistant bronzes by applying different coating techniques, such as cold spraying, HVOF spraying, warm spraying and arc spraying. By optimization to optimum cavitation resistance, the deposited coatings can increase the service life of ship rudders significantly and even serve as repair processes for ship propellers. The given overview aims to support the selection of processes when specifying the target properties to be set with regard to cavitation protection. By using high-pressure warm spraying and cold spraying, properties similar to those of cast nickel aluminum bronze were achieved, however at relatively high costs. In contrast, coatings produced by using HVOF and arc spraying have erosion rates that are only about four respectively three times higher as compared to cast nickel aluminum bronze, while far outperforming bulk shipbuilding steel. Hence, their properties should be sufficient for acceptable service life or docking intervals for ship rudder applications. Propeller repair might demand for better coating properties as obtained by cold spraying. With respect to costs, HVOF and arc spraying in summary might represent a good compromise to reach coating properties needed in application.
Low Temperature Soldering of Laser Structured and Metal Coated Fiber Reinforced Plastics
Authors: Gustke K. , Kupke D. , Drehmann R. , Lampke T. , Gebauer J. , Klotzbach U. , Lasagni A.F.
Published: September 2021

Assemblies containing fiber-reinforced plastic (FRP) and metal parts are typically fastened together via mechanical joining or adhesive bonding. Mechanical joining processes tend to weaken FRP parts by cutting fibers, while adhesives require long cures and often lead to inseparable material compounds. This paper evaluates a new joining method in which plastic parts are laser treated, then metallized via wire-arc spraying, and finally soldered to mating metal parts using a low-temperature process. Due to the effective increase in interface area resulting from laser structuring, bond strengths of up to 15.5 MPa can be achieved.
Effects of Composition on Antibacterial and Antiviral Properties of Suspension Plasma-Sprayed Hydroxyapatite/Titania Coating
Authors: Abir Mirazul Mahmud , Otsuka Yuichi , Miyashita Yukio
Published: September 2021

This study investigates the effect of composition on the antibacterial and antiviral properties of hydroxyapatite/titania composite coatings deposited by suspension plasma spraying. Hydroxyapatite is a bioceramic material used as a plasma-sprayed coating to promote osseointegration of femoral stems. TiO2 has promising photocatalytic activity and good efficiency in destroying bacteria, viral species, and parasites. Prior to coating, substrates were grit blasted, ultrasonically cleaned, and heated to enhance adhesion strength. The microstructure of the resulting coatings was then characterized using XRD and Raman spectroscopy. Test results indicated that SPS transformed Ti2O3 into TiO2 with mixed phases. Ti4O7 and Ti3O5 phases were also identified, which show photocatalytic activity due to oxygen vacancies. Antibacterial and antiviral tests were conducted as well.
Qualification of the Low-Pressure Cold Gas Spraying for the Additive Manufacturing of Copper-Nickel-Diamond Grinding Wheels
Authors: Tillmann W. , Zajaczkowski J. , Baumann I. , Schaak C. , Biermann D. , Kipp M.
Published: September 2021

Grinding wheels are usually manufactured by powder metallurgical processes, i.e. by moulding and sintering. Since this requires the production of special moulds and the sintering is typically carried out in a continuous furnace, this process is time-consuming and cost-intensive. Therefore, it is only worthwhile for medium and large batches. Another influencing factor of the powder metallurgical process route is the high thermal load during the sintering process. Due to their high thermal sensitivity, superabrasives such as diamond or cubic boron nitride are very difficult to process in this way. In this study, a novel and innovative approach is presented, in which superabrasive grinding wheels are manufactured by thermal spraying. For this purpose, flat samples as well as a grinding wheel body were coated by low-pressure (LP) cold gas spraying with a blend of a commercial Cu-Al2O3 cold gas spraying powder and nickel-coated diamonds (8-12 μm). The coatings were examined metallographically in terms of their composition. Afterwards, the grinding wheel was conditioned for the grinding application and the topography was evaluated. This novel process route offers great flexibility in the combination of binder and hard material as well as a costeffective single-part and small-batch production.
Novel Powder Modification Method for the Cold Spray of Hard Steels
Authors: Poirier D. , Thomas Y. , Guerreiro B. , Martin M. , Aghasibeig M. , Irissou E.
Published: September 2021

A novel powder modification method based on the simultaneous softening and agglomeration of steel powders via heat treatment in a rotary tube furnace has been investigated as a means to improve the cold sprayability of H13 tool steel powder. By adjusting starting powder size and shape as well as heat treatment conditions (maximum temperature, cooling rate, and atmosphere), cold spray of H13 powder went from virtually no deposition to the production of thick dense deposits with a deposition efficiency of 70%. Powder agglomeration, surface state, microstructure evolution, and softening are identified as key factors determining powder deposition efficiency and resulting deposit microstructure.
Use of Different Process Gases for Manufacturing Isolating Alumina Coatings by Flame Spraying with Cords
Authors: Hauer M. , Meyer M. , Billieres D. , Bricquet C. , Gerstgrasser F. , Kiilakoski J. , Lejay J. , Henkel K.-M.
Published: September 2021

This study assesses the quality of flame-sprayed alumina coatings produced from recently developed alumina cord using argon and compressed air as atomizing gases. Coatings of different thicknesses were deposited on aluminum substrates and then analyzed using optical microscopy, X-ray diffraction, and resistivity measurements. The coatings, particularly those sprayed with argon, had fine microstructure and higher surface and volume resistivity than flame-spray coatings made from alumina cord in the past. They were also found to have higher alpha phase content than plasma-sprayed coatings, regardless of the atomizing gas used. The effect of humidity and the possible formation of aluminum hydroxides are also addressed.
Influence of Fuel/Oxygen Ratio on Coating Properties and Cavitation Resistance of WC and Cr3C2 Cermet Coatings Deposited by HVOF
Authors: Becker A. , Bertoul K. , Pukasiewicz A.G.M. , Siqueira I.B.A.F. , Chicoski A. , Caliari F. , Vaz R.F. , Sousa M.J. de
Published: September 2021

Hydroelectric turbines are strongly affected by cavitation and the damage it can cause to critical part surfaces and profiles. The study of thermal spray processes and materials is thus relevant to improving turbine performance. The main objective of this work is to evaluate the influence of fuel-oxygen ratio on tungsten- and chromium-carbide cermet coatings deposited by HVOF. Particle velocity and temperature were measured as were coating hardness, porosity, and cavitation resistance. Higher particle velocities were obtained at higher fuel ratios, producing harder, denser coatings with better cavitation resistance. Based on test results, the wear mechanism starts with the nucleation of the cavitation that occurs in the pores, resulting in the formation of craters and the eventual detachment of lamellae as indicated by the smoothness of the surface.
Tribological and Corrosion Behavior of HVOF Sprayed Cr3C2-NiCr with Nickel Cladded Graphite and Hexagonal Boron Nitride
Authors: Oechsner M. , Engler T. , Scheerer H. , Joung Y. , Bobzin K. , Wietheger W. , Knoch M. , Schulz M.
Published: September 2021

High-velocity oxyfuel (HVOF) sprayed coatings of Cr3C2-NiCr containing solid lubricants such as nickel cladded graphite and hexagonal boron nitride were successfully developed and characterised with the aim of optimizing their friction and wear behaviour. HVOF technology was used for the integration of solid lubricants to achieve strong cohesion between particles while minimizing thermal decomposition. Coating microstructure and composition were measured and correlated to the results of tribological and corrosion tests. The integration of the solid lubricant greatly reduced friction and wear volume at room temperature, but the lubricating effect was highly dependent on atmosphere and temperature. Cr3C2-NiCr with hBN, however, tends to exhibit more stable wear resistance over a wider temperature range and can be used at temperatures beyond 450 °C.
How to get ill, stay ill and die
Authors: Hague Andrew
Published: September 2021

This is your death plan. Choose the easy options. Go with the flow. Do what you want to do. This will get you off the endless conveyor. No more effort and it’s all downhill. Be advised by advertisers, doctors who know nothing about food or exercise, a government that wants to squeeze you and business intent on profit. If you are reading this thinking you can do the opposite, think again. You will be fighting powers you did not know exist. Perhaps you should be in a cave without money, friends or help. Survival in a civilised society is difficult. Only the brave can go against the grain. There are three sectors: food, exercise and lifestyle. All three are waiting for you like monsters of the deep to suck you in and kill you. You think you are being looked after. Beware!
Cancer Cell Growth: - A Mini-Review Part-4: First threat (atherosclerotic lesions)
Authors: Koyunoğlu Cemil
Published: September 2021

The first 3 issues about cancer cells have been tried to explain -in the author papers- how the cells grow by using more energy in the tissue or organ compared to other cells, with the justification of scientific sources. The 4th series of articles will include detailed determinations about the initial threat of a cell growing in an organ or tissue to the organ or tissue by multiplying more than other cells. When a cell proliferates to a sufficient number of cells as mentioned in previous chapters, it begins to make its first threat. It fulfills this cell threat by expressing more than 100 disease forms within the organ. This is a phenomenon that occurs in all living cells. This was even seen in the most primitive invertebrates such as Mollusca and Arthropoda. Examinations of dinosaurs living 100 million years ago revealed the presence of neoplasms. Traces of the above constriction have been found in the cell work done on a 100,000-year-old human fossil. The most important sign of the first threat is phenotypic and genetic change. It creates the impression that it is threatened by a bacterial colony relative to other cells. These cells MIMIC the survival behavior and resistance of unicellular organisms that lived in the same ancient times.
Case report of a Rare Cause of Portal Hypertension
Authors: Aye Mra
Published: September 2021

Williams or Williams-Beuren (WBS) is a developmental disorder with multisystemic manifestations. Chromosome 7 microdeletion underlying WBS occurs because of the unique genetic architecture in this region. Facial features change from subtle to dramatic. The extent of mental and development problems is variable. Cardiovascular, endocrine, and nervous system involvement mostly affect the morbidity and mortality. Although many systems are involved in this syndrome, portal hypertension and splenomegaly are scarcely reported. We report a case of William syndrome with moderate splenomegaly and portal hypertension.
FATORES CLIMÁTICOS ATUANTES NO SEMIÁRIDO DE PERNAMBUCO: UMA ABORDAGEM DIDÁTICA DA GEOGRAFIA EM SALA DE AULA
Authors: ANGELO LEITE JOÃO PAULO
Published: September 2021

A demarcação do Semiárido Brasileiro foi feita em 1991 pela Empresa Brasileira de Pesquisa Agropecuária (Embrapa), sendo reconhecida cientificamente. O clima semiárido é presente em 88,6% do estado de Pernambuco sendo bem característico do clima as altas temperaturas devido à grande insolação solar durante todo o ano, e os baixos índices e irregulares de pluviosidade. Vários especialistas argumentam que a seca é oriunda do semiárido e sempre vai existir, por ser característica do clima. Sendo assim o presente trabalho tem como objetivo passar informações científicas acerca das influências climáticas que atuam no semiárido de Pernambuco, abordando seus aportes teóricos e práticos, para alunos do 5° Ano do Ensino Fundamental da Escola Maria Guilhermina de Jesus, Salgueiro - PE. O mesmo, justifica-se pela importância em trazer aos alunos o conhecimento sobre o clima da região semiárida no qual habitam. Apresentar os conceitos climáticos específicos da área de climatologia, diferenciá-los e aborda-los de forma mais simples e prática, uma vez que os livros didáticos e apostilas adotadas nos sistemas de ensino geralmente apresentam abordagens superficiais sobre o conteúdo de climatologia, muitas vezes não transcendendo os muros escolares. Os conteúdos foram abordados em duas etapas, uma vez por semana, a fim de não causar transtornos aos conteúdos programáticos planejados pelo professor da turma. Foi procurado, sempre respeitar a escolaridade dos estudantes e adequando os conteúdos de climatologia aos mesmos. Sendo de enorme valor que os alunos sejam motivados a compreender e aprender os diversos fatores climáticos existentes no semiárido de Pernambuco essenciais para sua formação escolar.
FUNÇÃO POLINOMIAL DO PRIMEIRO GRAU: UMA INVESTIGAÇÃO DA PRÁTICA COMÉRCIAL DE FEIRANTES DE CAMOCIM-PE
Authors: Santos Deric Vinicius , Rocha Petterson Santos , Silva Júlio Cesar da , Dos Santos Luan Danilo Silva , De Sousa Yrailma Katharine
Published: September 2021

A Etnomatemática estuda relações existentes entre o conhecimento matemático e os diferentes povos a quem é apresentado, considerando no processo de ensino e aprendizagem fatores políticos, econômicos, sociais e o conhecimento prévio, como importantes pontos a serem trabalhados. Nessa perspectiva, se abre precedentes para uma discussão mais ampla de conceitos matemáticos, por exemplo, o conceito de funções polinomiais do primeiro grau, um conceito matemático que apresenta relações com outras ciências e aplicabilidades ao cotidiano. Tendo em vista esses pontos, nessa pesquisa objetivamos analisar de que maneira a função polinomial do primeiro grau é envolvida na prática de feirantes da cidade de Camocim-PE, de modo a respondermos à inquietação: de que maneira a função polinomial do primeiro grau, se apresenta na prática de trabalho de feirantes? Metodologicamente, a pesquisa foi classificada numa abordagem qualitativa de tipologia descritiva, e teve como participantes cinco feirantes. A produção dos dados, se deu através de entrevista semiestruturada gravada em áudio, e por registros de soluções, que envolveram questionários abertos. Ambos instrumentos auxiliaram no entendimento da articulação entre os participantes, com a função polinomial em problemas relacionados às suas vivências no comércio. O conteúdo da análise foi transcrito, categorizado e inferido com base na análise de conteúdo. As inferências mostraram que o conhecimento de função do primeiro grau é apresentado de forma recorrente, na prática comercial dos feirantes, como, por exemplo, em situações que envolvem cálculo do lucro. Com isso, de maneira geral, concluímos que os profissionais investigados são detentores de um conhecimento matemático prático, mais especificamente a funçõespolinomiais do primeiro grau, pois a utilização desse conhecimento se fez presente corriqueiramentenos cálculos necessários à sua profissão.
Commercial Activity: Intera-Regional Trade & Commerce between Sind and Multan in Colonial period (1849-1901)
Authors: Chuadhary Abida Kausar
Published: September 2021

This research deals with the trade relations between two major towns of Karachi and Multan in the colonial period. The aim of this article is to develop a general narrative of the commercialization of crops that led to the growth of intra-regional trade and economy-addressing the issues of how these two centers contributed to the new economic development of South Asia as well as marinating their historical trade relations? Tracing the journey of agricultural production from the village mandis to the international markets, we examine the commercial network and the nature of the interaction. It will also saw the increasing and decreasing trends of trade in the following years. The research aims to draw a conclusion by using qualitative and quantitative methods for assessing its historical importance and analyze these towns as case studies. Karachi and Multan have been the two most populous and largest economies in South Asia. Being the prominent constituents of colonial India, both have a great potential for intra-regional commerce through three channels of rail, road and ports. This research is based on original, unpublished official administrative reports of British Indian Library London and Punjab Civil Secretariat Lahore.
Effects of Harassment on Academic Performance: A Case of University Students of Lahore
Authors: Babar Zaheer Ud Din , Saleem Noshina
Published: September 2021

This research study attempted to explore the effects of cyber harassment and traditional harassment on the academic performance of university students. Likewise, investigating the influence of this harassment on substance usage was another prime objective of the study. For this purpose, students of four Lahore based universities (2 public, 2 private) were taken as population. Similarly, using convenience sampling, 150 respondents from each university were selected to meet a total sample of 600 students. For data collection, a cross-sectional survey method was used; however, for data analysis, a one-way analysis of variance was done so that demographics differences could be checked. Whereas Pearson product-moment correlation was applied to tests the relationships between IVs and DVs. Results evidently found that the majority of the students faced one or both types of harassment, i.e. traditional and cyber, which resulted in their indulgence in substance usage practices.
Exploring the Practices of Government Secondary School Teachers about National Professional Standards for Teacher
Authors: Altaf Fasiha , Saeed Muhammad
Published: September 2021

or enhancing the quality of teachers, the Government of Pakistan introduced the National Professional Standards for Teachers in 2009. The study was qualitative in nature. A case study design was adopted to conduct the research. A purposive criterion sampling technique was used to select the sample. A semi-structured interview and observation checklist was developed by the researcher. The instruments were validated and improved in the light of experts� opinions. Research ethics were observed during the study and before the data collection. Themes were generated and interpreted which were relevant to the research questions of the study. The findings of the study indicate that public sector teachers have command of the subject matter knowledge, but lesson planning and proper assessment are missing. It is being recommended that awareness about the National Professional Standards must be created among public sector teachers and teachers should be made bound for planning their instructions according to standards.
Depression among Pregnant Females in Punjab, Pakistan: Effect of State-Trait Anxiety
Authors: Sajjad Rabia , Rauf Umara , Saheed Rafit
Published: September 2021

The objective of the study is to examine the impact of state-trait anxiety on depression among pregnant females. A crosssectional study was carried out on pregnant females of all three trimesters from March 2019 to December 2019. The study collected data from pregnant females 153 age 18 to 47 years using the purposive sampling technique. Respondents were from Government and private hospitals of two metropolitan cities of Punjab, Pakistan (Lahore and Faisalabad). All the pregnant females completed a demographic sheet, State-Trait Anxiety Inventory(S-TA), and Center for Epidemiologic Studies Depression Scale (CES-D) to assess the level of anxiety and depression among pregnant females. The SPSS version 23 was used for data analysis. The regression results highlighted that state-trait anxiety positively predicted depression among pregnant women, with a 16% variance in the outcome variable. Pregnant females experience a diverse level of anxiety and stress that can have serious consequences for the childbearing women as well can make the pregnancy process more complicated if treated with early intervention.
Economic Effects of Seawater Intrusion on Life of Coastal Communities in Sindh Region of Pakistan
Authors: Jagirani Shoaib Ahmed , Guriro Subhash , Lakho Muhammad Kamil
Published: September 2021

Recently rising sea levels and a decrease of Indus water into the delta have resulted in high seawater intrusion at the coastal shores of Sindh. Seawater intrusion has severely affected the livelihood sources of local people. Therefore, this study is conducted with an aim to measure the economic effects of seawater intrusion on the lives of the local population in the deltaic coasts of the Sindh region in Pakistan. This is a quantitative study conducted through a survey questionnaire in the coastal belt of Badin and Thatta districts of Sindh province, Pakistan. A total of 200 participants were recruited in the study through multistage sampling. Results show a significant impact of seawater intrusion on the economic conditions of coastal communities in the province of Sindh, Pakistan. Adverse effects of seawater intrusion can be seen in the shape of a decrease in cultivated land, low agricultural production, decreasing livestock production and fishing quantity.
Economic complexity and embedding of regional economies’ structures
Authors: Afanasiev Mikhail
Published: September 2021

The research focuses on the development of localized specialization and economic diversification theories. Our task is forecasting of the emergence of new strong sectors in the region. On the basis of probabilistic and statistical modeling the model which allows estimating the probability of appearing a new strong sector in the region taking into account characteristics of economic structure is constructed. The possibility of building such a model is based on the assumption that the emergence and development of sectors is largely determined by the evolution of past economic activity. The model uses the indicators of embedding structures of the strong sectors in the regional economies is introduced by the authors. These indicators are based on the probabilistic interpretation and properties of the elements of the matrix, by which economic complexity is estimated following the traditional approach. The probability of originating a strong sector in the structure for each region is estimated. Based on sorting the sectors according to the value of these probabilities and assessments of their potential contribution to socio-economic development expert assessment of the feasibility of developing a new strong sector in the region can be made. The results show that sectors’ introduction and generation in the regional economy is largely due to the evolution of the past economic activity.
Value-at-Risk and Expected Shortfall approaches for option premiums and the probability of default estimation based on ARMA models
Authors: Berzon Nikolai
Published: September 2021

The need to address the issue of risk management has given rise to a number of models for estimation the probability of default, as well as a special tool that allows to sell credit risk – a credit default swap (CDS). From the moment it appeared in 1994 until the crisis of 2008, that the CDS market was actively growing, and then sharply contracted. Currently, there is practically no CDS market in emerging economies (including Russia). This article is to improve the existing CDS valuation models by using discrete-time models that allow for more accurate assessment and forecasting of the selected asset dynamics, as well as new option pricing models that take into account the degree of risk acceptance by the option seller. This article is devoted to parametric discrete-time option pricing models that provide more accurate results than the traditional Black-Scholes continuous-time model. Improvement in the quality of assessment is achieved due to three factors: a more detailed consideration of the properties of the time series of the underlying asset (in particular, autocorrelation and heavy tails), the choice of the optimal number of parameters and the use of Value-at-Risk approach. As a result of the study, expressions were obtained for the premiums of European put and call options for a given level of risk under the assumption that the return on the underlying asset follows a stationary ARMA process with normal or Student's errors, as well as an expression for the credit spread under similar assumptions. The simplicity of the ARMA process underlying the model is a compromise between the complexity of model calibration and the quality of describing the dynamics of assets in the stock market. This approach allows to take into account both discreteness in asset pricing and take into account the current structure and the presence of interconnections for the time series of the asset under consideration (as opposed to the Black–Scholes model), which potentially allows better portfolio management in the stock market.
Valuation of machinery and equipment subject to the Wiener degradation process
Authors: Smolyak Sergey
Published: September 2021

We propose a model describing the decrease in the market value of machines (depreciation) with age. Usually it is characterized by the percent good factor, i.e. the ratio of machine’s value to the value of similar new machinery item. Often, appraisers know about a used machinery item only by its age, but not its performance. Therefore, for the valuation of the machinery item of a known age, they have to use the mean (for machines of this age) of percent good factor. In the proposed model, the state of the machine is characterized by the intensity of the benefits it brings. In this case, the benefits from using the machine in a certain period are defined as the market value of the work performed by it minus operating costs. We describe the change in the intensity of benefits over time by the Wiener process with negative drift. This allows us to take into account the tendency for the performance of machine to deteriorate during operation. The market value of a machine is defined as the maximum mathematical expectation of the sum of discounted benefits from its use. It is shown that it corresponds to the moment the machine reaches a certain boundary state. The parameters of the Wiener process (drift and volatility) are expressed through the known characteristics of the machine's durability, namely the average value and the coefficient of variation of the service life. The dependences of the mean percent good factor of machines on the relative age (the ratio of age to the average service life) are found. It turned out that these dependencies are almost independent of the discount rate and average service life.