bluuebunny/crossref_metadata_2025 huggingface dataset:
FACTORS OF QUALITY OF THE EXHIBITION STAND - DEVELOPING A NEW YARDSTICK
Authors: Mumel Damijan
Published: June 2021

This paper presents a piece of research with two main goals: (1) to find out essential factors of quality of the exhibition stand and (2) to devise a measuring instrument for measuring the quality of exhibition stands, both from the nonprofessional attendee’s point of view. To reach both goals, first, fourteen dimensions of quality of exhibition stands were identified. These dimensions were taken as the basis for the composition of the first version of the measuring instrument concerning the quality of the exhibition stands (M1MQES-1). When MIMQES-1 was tested the congruity of assessors was also examined. On the basis of the analysis of MIMQES-1 the second version of MIMQES (MIMQES-2) was formed and the preparation procedure for assessors was changed and improved. The results of MIMQES-2 analysis show a better factor structure as well as a better congruity of assessors, which was probably the result of a change in qualification of assessors.
LANGUAGE INVESTIGATIONS AS A MEANS OF IMPROVING QUALITY IN THE HOSPITALITY INDUSTRY
Authors: Miškulin Čubrić Dolores
Published: June 2021

This paper is the result of a number of language investigations carried out by the author in order to find out the extent to which operators in the field of tourism and the hospitality industry value the importance of foreign languages in their everyday work as well as the factors that motivate hospitality management language students in learning foreign languages. The aim of the article is to summarize the findings of our research so as to give a possible answer about the way of improving quality in the hospitality industry through improving competence in foreign languages.
Decoding the Roles of Astrocytes and Hedgehog Signaling in Medulloblastoma
Authors: Duarte Terence Teixeira , Teixeira Silvia , Gonzalez-Reyes Luis , Reis Rui Manuel
Published: June 2021

The molecular evolution of medulloblastoma is more complex than was previously imagined as emerging evidence suggests that multiples interactions between the tumor cells and components of the tumor microenvironment (TME) are important for tumor promotion and progression. The identification of several molecular networks within the TME, which interact with tumoral cells, has provided new clues to understand the tumorigenic roles of many TME components as well as potential therapeutic targets. In this review, we discuss the most recent studies regarding the roles of astrocytes in supporting the sonic hedgehog (SHH)–activated medulloblastoma molecular subgroup, and provide an overview of medulloblastoma progression through SHH expression and signal transduction mechanisms into the complex tumor microenvironment. In addition, we highlight the associations between tumor and stromal cells as possible prognostic markers and new therapeutic strategies.
Cannabis Inflorescence Yield and Cannabinoid Concentration Are Not Improved with Long-Term Exposure to Short-Wavelength Ultraviolet-B Radiation
Authors: Rodriguez-Morrison Victoria , Llewellyn David , Zheng Youbin
Published: June 2021

It is commonly believed that exposing Cannabis sativa (cannabis) plants to ultraviolet (UV) radiation can enhance Δ9-tetrahydrocannabinol (Δ9-THC) concentrations in female inflorescences and associated foliar tissues. However, a lack of published scientific studies has left knowledge-gaps in the effects of UV on cannabis that must be elucidated before UV can be utilized as a horticultural management tool in commercial cannabis production. In this study we investigated the effects of UV exposure level on photosynthesis, growth, inflorescence yield, and secondary metabolite composition of two indoor-grown cannabis cultivars: ‘Low Tide’ (LT) and ‘Breaking Wave’ (BW). After growing vegetatively for 2 weeks under a canopy-level photosynthetic photon flux density (PPFD) of ≈225 μmol·m–2·s–1 in an 18-h light/6-h dark photoperiod, plants were grown for 9 weeks in a 12-h light/12-h dark “flowering” photoperiod under a canopy-level PPFD of ≈400 µmol·m–2·s–1 and 3.5 h·d–1 of supplemental UV radiation with UV photon flux densities (UV-PFD) ranging from 0.01 to 0.8 μmol·m–2·s–1 provided by light-emitting diodes (LEDs) with a peak wavelength of 287 nm (i.e., biologically-effective UV doses of 0.16 to 13 kJ·m–2·d–1). The severity of UV-induced morphology (e.g., whole-plant size and leaf size reductions, leaf malformations, and stigma browning) and physiology (e.g., reduced leaf photosynthetic rate and reduced Fv/Fm) symptoms worsened as UV exposure level increased. While the proportion of dry inflorescence yield that was derived from apical tissues decreased in both cultivars with increasing UV exposure level, total dry inflorescence yield only decreased in LT. The equivalent Δ9-THC and cannabidiol (CBD) concentrations also decreased in LT inflorescences with increasing UV exposure level. While the total terpene content in inflorescences decreased with increasing UV exposure level in both cultivars, the relative concentrations of individual terpenes varied by cultivar. The potential for using UV to enhance cannabis quality must still be confirmed before it can be used as a production tool for modern, indoor-grown cannabis cultivars.
New Graph Of Graph
Authors: Garrett Henry
Published: June 2021

Constructing new graph from the graph's parameters and related notions in the way that, the study on the new graph and old graph in their parameters could be facilitated. As graph, new graph has some characteristics and results which are related to the structure of this graph. For this purpose, regular graph is considered so the internal relation and external relation on this new graph are studied. The kind of having same number of edges when this number is originated by common number of graphs like maximum degree, minimum degree, domination number, coloring number and clique number, is founded in the word of having regular graph
Analyzing Millennial Generation Awareness on Nationalism During Covid-19 Pandemic
Authors: Nur Hayati Sab Fitri , Pandin Moses Glorino Rumambo
Published: June 2021

Background: In the current era of globalization, the Indonesian government's problem today is the weakening of nationalism and patriotism among the millennial generation. The large number of foreign cultures that have entered Indonesia has caused a sense of nationalism and patriotism. In addition, Indonesia is also facing the problem of spreading the Covid-19 virus. During the pandemic, various policies set by the government received protests from some circles because they felt their freedom was restricted. Therefore, the awareness of millennial generation nationalism is needed, especially during the Covid-19 pandemic like today. This research aims to make millennials aware of nationalism sense, which mainly to prevent the spread of Covid-19. This research is used to answer the questions of what the problems that arise due to the waning of the spirit of nationalism during the pandemic are? and what efforts should be made to maintain the spirit of nationalism? Methods: This research is a qualitative study using the literature review method. The articles used are research published in 2019 to 2021 in Google Scholar, with keywords that match the topic of millennial generation nationalism in the Covid-19 pandemic. Results and Discussion: The results of the study found that the spirit of Indonesian nationalism during the Covid-19 pandemic was decreasing. The decline in the sense of nationalism is due to several government policies that impact the psychology of society and the Indonesian economy. As a result, society, particularly the millennial generation, must play a role in breaking the chain of the Covid-19 virus's propagation by following the government's health standards. Conclusion: The government and society need to work together to understand nationalism in the millennial generation, especially in dealing with problems caused by the Covid-19 pandemic. Based on this, various efforts need to be made to foster the spirit of nationalism and overcome the Covid-19 pandemic. So that later, it can produce a generation that upholds the value of nationalism in everyday life.
Mortalidade adulta por nível de escolaridade em São Paulo: análise comparativa a partir de diferentes estratégias metodológicas
Authors: Martins Ribeiro Mirian , Maldonado Turra Cassio , Campos de Xavier Pinto Cristine
Published: June 2021

Neste artigo, são estimados os diferenciais educacionais de mortalidade de adultos residentes em São Paulo. É realizada uma análise comparativa de estimativas a partir de dados do Censo 2010 e do Sistema de Informação de Mortalidade (SIM) – Datasus e de três formas distintas de mensuração da escolaridade: registrada no SIM; declarada no Censo para o responsável pelo domicílio; e imputada estatisticamente no Censo para indivíduos que morreram. Para as imputações da escolaridade, utilizou-se o método de Dempester (1977), que propõe o uso do algoritmo esperança-maximização (algoritmo E-M) para lidar com dados faltantes. Foram considerados três níveis de escolaridade (baixo, médio e alto) e estimadas as taxas de mortalidade com base em modelos Poisson. Os resultados indicam que a obtenção de escolaridade pode reduzir em até 77% as taxas de mortalidade entre 25 e 59 anos de idade. Além disso, em um país em que a população tem baixa escolaridade, obter ensino médio representa um ganho significativo do ponto de vista da sobrevivência adulta (cerca de 50%). Encontraram-se padrões de mortalidade por escolaridade semelhantes para as estimativas obtidas com dados registrados no SIM e aqueles imputados no Censo 2010. Além disso, a análise sugere que estimativas assumindo a escolaridade do responsável pelo domicílio resultam em diferenciais de mortalidade atípicos, provavelmente distorcidos pela transição de educação no Brasil. Espera-se que o modelo de imputação proposto aqui possa ser utilizado em futuras análises dos dados de mortalidade a partir do Censo 2010.
Existe um efeito negativo duplo sobre os salários das mulheres migrantes nas regiões brasileiras? Uma abordagem não paramétrica
Authors: Silva de Aguiar Maria Adreciana , Santos de França João Mário
Published: June 2021

Este artigo busca verificar se existe um efeito negativo duplo sobre os salários das mulheres migrantes (não naturais e de retorno) nas regiões brasileiras. Para captar o diferencial salarial, empregou-se o método não paramétrico de Ñopo (2008) aplicado aos dados obtidos a partir da Pesquisa Nacional por Amostra de Domicílios (PNAD) de 2005 e 2015. Os resultados mostraram que apenas a mulher migrante não natural na região Sudeste sofre de dupla desvantagem no mercado de trabalho. A primeira desigualdade salarial refere-se à questão de gênero e ocorre também nas demais regiões brasileiras. A segunda diferença no salário deve-se à condição de migrante não natural da região Sudeste. Para as demais regiões, as mulheres migrantes (não naturais e de retorno) possuem uma vantagem salarial em relação às não migrantes.
SMART GRID TECHNOLOGY, TRANSMISSION OF ELECTRICAL ENERGY IN POWER SUPPLY AND LIGHTING SYSTEMS OF CITIES
Authors: Hovorov P. P. , Hovorova K. V. , Kindinova А. К. , Abdelrahim O.
Published: June 2021

Modern power supply and lighting systems of cities are complex electrical systems of an automated type, in which the processes in individual power supply systems and city lighting systems are interconnected and interdependent. Therefore, the search for efficient technologies for the transmission of electrical energy in them is an extremely difficult task. The real state of the power supply and lighting systems in cities today is characterized by low operating efficiency, largely due to the low quality of electrical energy and insufficient compensation of reactive power in them. The mutual influence of power supply and lighting systems in cities, as well as the presence of significant voltage deviations and the overflow of additional reactive power in the networks, causes an increase in voltage and power losses in them, as well as a decrease in the efficiency of networks and connected consumers, in general. Unfortunately, the existing methods and technical means based on them cannot fully solve this problem. The research carried out made it possible to clarify the nature of the processes in the power supply systems and the sanitation of cities and to determine the methods and technical means based on the Smart Grid concept. They are based on the use of phase-shifting booster transformers with an electronic control system. Their use made it possible to provide the possibility of complex control of the voltage modes of active and reactive power with the possibility of installation at any point in the network and centralized control from a single centre. The calculations show that the use of the developed methods and technical means provides an opportunity to reduce power losses in networks by 10–15% and energy costs for consumers by 50–75%.
IMPROVEMENT OF FUEL ELEMENT SHELL CONTROL METHODS TO INCREASE NUCLEAR REACTOR SAFETY
Authors: Budanov P. F. , Brovko K. Yu. , Khomiak Е. А. , Tymoshenko О. А.
Published: June 2021

The analysis of the existing methods of control of the surface of the fuel element cladding material was carried out, which showed that their use for detecting surface and internal defects, such as local inhomogeneities, micro- and macropores, various cracks, axial looseness, etc. is characterized by low efficiency, is a laborious process that requires additional surface treatment, material of the fuel elements cladding. In addition, the investigated methods of controlling the surface of the fuel element cladding material make it possible to visually identify only rough external cracks and large slag inclusions, small cracks and non-metallic inclusions invisible under the slag layer. It is proposed to assess the quality of the surface of the shell material in case of its damage and destruction, the use of a computational apparatus based on the method of the theory of fractals. It is proposed to use the fractal properties of the shell material structure and a quantitative fractal value – the fractal dimension, which makes it possible to determine the degree of filling of the volume of the shell material structure during fuel element depressurization. A mathematical model of damage to the structure of the fuel element cladding material is developed depending on the simultaneous effect of high temperature and internal pressure caused by the accumulation of nuclear fuel fission products between the nuclear fuel pellet and the inner surface of the fuel element cladding, taking into account the fractal increases in the geometric parameters of the fuel element cladding. It is shown that damaged structures of the fuel rod cladding material depend on the pressure and temperature inside the fuel rod cladding, as well as the fractal increase in geometric parameters, such as: volume and surface area, outer and inner diameters, height and cross-sectional area, cladding length and height of nuclear pellets, gap between the inner surface of the cladding and nuclear fuel. A criterion for assessing the integrity of the fuel rod cladding is determined, which depends on the change in geometric values in the event of damage and destruction of the structure of the fuel rod cladding material. Practical recommendations are given on the use of the proposed method for monitoring the tightness of the fuel element cladding for processing information obtained from the computational module of the system for monitoring the tightness of the cladding for the automated process control system of the nuclear power plant power unit, which makes it possible to detect the depressurization of fuel elements at an earlier stage in comparison with the standard procedure.
METHOD OF MEASURING POWER CONSUMPTION OF ELECTRIC RECEIVERS ON THE EXAMPLE OF THE EDUCATIONAL BUILDING OF SUMY STATE UNIVERSITY
Authors: Shevchenko S. Yu. , Borzenkov І. І. , Lebedinsky I. L.
Published: June 2021

Commercial means of automatic control system of electricity metering, as is known, are installed on the input switchgear and measure the power consumption of all electrical consumers of this metering facility. Such data do not give a complete picture of electricity consumption on each floor of the metering facility, which in turn does not allow the implementation of energy saving measures. Also, these metering systems for electricity metering have a high cost. The article proposes a method of data processing and transmission to the server with their subsequent analysis of power consumption on each floor of the object under study using the ARDUINO microcontroller. Such an accounting system has a lower cost than an automatic control system of electricity metering industrial production. The article presents the scheme of implementation and types of current and voltage sensors. The topology of the measuring complex is also considered in the article. Such a topology can expand and keep not only the general account of a concrete floor, but also in the generality of each educational audience separately. Collecting such data on electricity consumption, it is possible to conduct a qualitative analysis of rational electricity consumption in the educational process, it means that for example in sufficient natural light artificial lighting in the classroom does not need to be used, or after laboratory tasks in a computer class, computers there is still some time. The introduction of energy-saving housing is performed due to the comparative characteristics of the power of gadgets, laboratory stands, etc. with the number of students in the group in accordance with the approved educational process. The algorithm of data processing, analysis of rational use of electric energy and comparative characteristics are implemented on the university server.
THE INFLUENCE OF THE INPUT INDUCTANCE ON THE QUALITATIVE INDICATORS OF ACTIVE CONTROLLED RECTIFIER
Authors: Krylov Denis , Kholod Olga
Published: June 2021

The main part of electricity is used by industrial plants in a converted form and the use of semiconductor converters is growing rapidly. The requirements for the quality of semiconductor converters are increased. And their impact on the power supply, load and related consumers is increased too. One of the most popular converters in the segment of low and medium power drives is a frequency converter made on the basis of a three-phase stand-alone voltage inverter. A significant disadvantage of such converters is the use of a diode rectifier at the input of the circuit, which has disadvantages as the inability to recover electricity to the mains in the mode of dynamic braking of an induction motor and significant distortions of the mains current. These disadvantages can be eliminated by using an active rectifier instead of a diode rectifier, which provides a sinusoidal shape of the mains current in phase with the mains voltage and the possibility of bidirectional energy exchange with the load. The efficiency of the active rectifier-voltage source is determined by the selected control algorithm of the circuit switches and the correct task of the inductance of the input choke. A mathematical model of a three-phase active rectifier-voltage source, working with a fixed modulation frequency with a vector algorithm for building a control system and analysis of the influence of the input inductance on the quality of its work was created. From the simulation results it became obvious that the proposed structure of the control system provides stable operation of the converter and acceptable standards for electromagnetic compatibility with the mains at a fixed modulation frequency; the proposed algorithm for calculating the value of the input inductances allows you to correctly select their allowable value, and obtained in the simulation of the dependence allows you to most accurately determine the value of the input inductances on the allowable level of distortion of mains current and supply voltage.
DETERMINATION OF THE RATIONAL ALLOWANCE FOR BLANK SURFACE TREATMENT BY THE CRITERION OF TECHNOLOGICAL DAMAGE
Authors: Kusyi Yaroslav , Topilnytskyy Volodymyr
Published: June 2021

The multiplicity of causal relationships as a functions of the response of the physical processes and the environmental influences are realized by means of providing of service functions of mechanical engineering products. This provides the evolution of quality indicators of the product in its Life Cycle and the formation of the conditions for physical and moral wear of products and machines. Rational management of technological inheritability of material properties of machine products to provide their operational characteristics and reliability indicators by means of the synergetic approach is a methodological basis for the design of advanced technological processes of products manufacturing. Technological providing of standart quality indicators of products is realized by a limited number of rational variants of relations between the product and the technological environment using necessary number of stable connections. The choice of rational optimization criteria to solve the technological problems, in particular, the calculation of allowances for workpieces machining, at the substages of design and technological preparation provide the necessary initial parameters of products and their operational characteristics during manufacturing and assembly. It also allows to predict the behavior of products and machines at the operation stage of their Life Cycles. A method of choosing a rational allowance for surfaces treatment of castings, taking into account the technological inheritability of material properties was studied. Traditional methods of the allowance determining during products machining are analyzed. Technological damageability as a criterion for optimization in solving technological problems is proposed. The LM–hardness method used to select the allowance for the treatment of functional surfaces of the product is presented. Technological providing of the experimental researches is described. Rational values of the allowances for processing of aluminium alloy flat workpiece are 4–7 mm as a result of experimental researches depending on an arrangement of stress concentrators. The directions of further researches are determined.
DIELECTRIC OIL`S TEST MACHINE WISH VOLTAGE RISE ELECTRONIC MODULE
Authors: Bogatirov Igor , Ponuzhdayeva Helena , Koliushko Denis , Rudenko Serhii , Istomin Alexander
Published: June 2021

For test operations according to the liquid dielectric breakdown voltage measurement method we use high voltage machines that consist of high-voltage step-up transformer, voltage rise block, test cell with electrodes and so on. Described dielectric oil's test machine UIM – 90 with electromechanical voltage rise block. Cause of hard requirements in specification documents about voltage sine wave form on cell's electrodes, we performed field tests for UIM – 90 that help to evaluate the mains voltage impact on the test voltage distortion and measurement accuracy. Was discovered that during usage of electromechanical voltage rise block voltage steps disrupt sine wave’s form proportionally to step-up transformer’s transformation coefficient. Performed analysis of this block’s construction and established that usage of ЛАТР and mechanical voltage controller could lead to additional sine’s wave disruption. Decided to develop electronic voltage rise block which will allow to get rid of mains influence on test data. Created the algorithm of wave shaping from microcontroller, which generates voltage ramp to the amplifier representing pulse width modulator, then to the step-up transformers cascade. Proposed to use additional transformer for level matching of amplifier’s output voltage and main high voltage transformer’s input voltage. Presented flow sheet for UIM – 90 with electronic voltage step-up block and cascading start ofstep-up transformers. Provided voltage oscillograph trace and it spectrograph on the main transformer’s primary side, received due to the implementation of developed electronic voltage step-up block, prove that voltage sine wave form  doesn’t rely on mains quality. After upgraded UIM – 90 and it world analogues technical parameters analysis we could make a conclusion about it competitive capability on global level.
Dissolution of Sulfates and Sulfides Field Scales by Developed Scale Dissolver
Authors: Gamal Hany , Elkatatny Salaheldin , Al Shehri Dhafer , Bahgat Mohamed
Published: June 2021

Oil and gas industry deals with fluid streams with different ions and concentrations that might cause scale precipitation. The scale precipitation, will thereafter, affect the fluid flow characteristics. Many problems will be raised by the scale deposition that affects the overall petroleum production.

This paper aims to develop a non-corrosive acid system with high dissolution efficiency for field complex scales that have sulfates and sulfides minerals. The paper provided a series of lab analysis that covers the compositional analysis for the collected scale sample, and evaluating the developed acid system for compatible and stable properties, dissolution efficiency, and the corrosive impact. A field scale sample that has a composite chemical composition of paraffin, asphaltene, sulfides and sulfates compounds with different weight percentages by employing the diffraction of X-ray technology. Developing the new scale dissolver was achieved by specific compositional study for the organic acids to achieve high dissolution efficiency and low corrosive impact for the field treatment operations. The study results showed the successful scale removal for the developed dissolver at low temperature of 95 and 113 °F for surface treatment jobs. The dissolution efficiency recorded 62 and 71 % for 17 hours at the temperature levels respectively. The fluid showed a stable and compatible performance and has a pH of 12. The corrosion test was conducted without any scale inhibitors and the results showed the low corrosion effect by 0.0028 lbm/ft2. The obtained successful results will help to dissolve such complex field scales, maintain the well equipment, and maintain the petroleum production from scale issues.
Erosion Corrosion of Drill Pipe During Drilling Operations
Authors: AL-Yasiri Mortatha Saadoon
Published: June 2021

The presence of high rotating speeds and weights, the corrosiveness of water-based drilling muds, and high-speed mud with embedded cuttings, exposing drill string components to severe wear and corrosion that reduce their service life. The drill pipe erosion, abrasive wear and corrosion depend on properties of drilled cuttings and drilling fluids. Any variation in these properties leads to change in pipe degradation rate. There is a need to study the effect of individual factors, for expecting the drill pipe series life and to find a solution to this challenging problem. This research aims to evaluate the influence of real rock cuttings sizes and concentration as well as we investigate the effect of base fluid type on the erosion-corrosion rate. Actual drilled cuttings have been sieved to get three sizes of erodent cuttings; namely, 0.841 to 3.3 mm. Experiments are done with three sand concentrations (5%, 10% and 15%). The rate of erosion-corrosion of the drill pipe specimens is measured as the loss of weight per unit surface area per unit time under the dynamic action of solid particles. The eroded surfaces of the specimens are examined using Scanning Electron Microscopy (SEM) to visualise the impact of the drill cuttings at various conditions. It is seen that the rate of corrosion/erosion decreases with the increase of drilled cuttings concentration. Also, high erosion-corrosion rate is detected in situation of large drill cuttings particles. In this research, we explored a novel simple technique to simulate pipe erosion-corrosion in a reservoir-like environment. Furthermore, this paper proposed a new approach to control drill pipe erosion-corrosion by using SiO2-nanofluid.
Prevent Failures and Extend Asset Life: A Reliable Onsite Corrosion Inhibitor Residuals Method Using SERS
Authors: Jin Peng , Murugesan Sankaran , Liu Zhengwei , Fang Haitao , Gao Shujun , Huang Lei , Guerrero Gilberto , Jackson Tracey , Ramachandran Sunder , Brooks Johnathon
Published: June 2021

Asset integrity for oil and gas operations requires reliable chemical information to troubleshoot factors affecting chemical deliverability and performance. Accurate and precise measurement of corrosion inhibitor (CI) concentration in oilfield brine is significant to asset management. However, historically CI residual measurements are extremely problematic due to the surface-active nature of the chemicals which interact with a host of factors that parasitically deplete the CI solution concentration. It is typical to see >100% error on traditional residual measurements especially where dye transfer techniques are concerned. Current methods and sample handling for measuring residuals involves sending samples to a local laboratory for analysis. This time delay can add to the measurement error due to loss of inhibitor species to the sample container or solids that may form in transport. This paper describes the use of a simple, portable, handheld, onsite, nanotechnology-based, residual method to measure CI concentrations in oilfield brines. With more frequent and highly accurate CI residual feedback operators can react to system conditions that threaten to impact asset integrity. Using the CI residual data provided by a rapid, accurate analytical method, operators could extend asset life and prevent failures long before they become critical.
Comprehensive Casing Corrosion Inspection Using Multi-Frequency Array EM Technology
Authors: Larbi Zeghlache Mohamed , Bazaid Abdulaziz , Hill Freeman , Guergueb Nacer
Published: June 2021

Historically, only total metal thickness measurement was possible using frequency domain electromagnetic (EM) logging tools. With advances in technology, it is critical to develop a frequency domain alternative answer using a multi-frequency array EM pipe inspection tool to accurately estimate the individual wall thicknesses of as many as five concentric pipes. Results from yard testing in a special design mockup, as well as field logs, are demonstrated as part of the technology assessment process.

The new multi-frequency array EM tool uses the eddy current principle and includes two transmitters and eight receivers. It operates in continuous wave mode at multiple frequencies. Optimized transmitter-receiver spacing configurations and multi-frequency operation provide sufficiently diverse information to help assess the metal loss in each individual pipe for a wide range of configurations. The tool uses a sophisticated workflow of data processing and inversion algorithms to decouple individual thickness information from the measured data.

The capabilities of the tool are demonstrated using two 400-ft long pipe mockups, each having 18 different combinations of overlapping and non-overlapping defects in five-, four-, and three-pipe sections. The configurations of the pipes used in the mockups were chosen to cover typical well completions commonly used in the Middle East. Data from the mockups are validated using synthetic data generated using two-dimensional (2D) computer models. The tool has delivered unprecedented accurate assessments of the fourth and fifth pipes, as well as an accurate assessment of the commonly evaluated first, second, and third pipes. The sensitivity of the inversion to model mismatches, such as those introduced by decentralized pipes, is studied by deliberately decentralizing one of the mockup pipes over a length of the log. An algorithm designed to correct for pipe eccentricity is also demonstrated. The results from the surface testing are discussed along with the performance of the tool in a test well with pipe configurations similar to the mockups. In the studied test well, the tool was able to identify defects in the outermost strings.

This solution utilizes a novel inversion algorithm of big data from multi-frequency array sensors to derive individual pipes corrosion. This technology can significantly improve proactive decision making for mature well operations, especially in areas with high corrosion rates and shallow outer casing corrosion.
Failure Investigation of a Corrosion Leak in a C77 Block and Tubing Bonnet in a Chemical Injection System – A Case History
Authors: De Souza Valdir , Marinou Eugenia , Legge Andrew , Nwafor Vicky
Published: June 2021

This paper presents a case history outlining the investigation performed to evaluate the causes of failure between a C77 block and tubing bonnet line, used for delivering scale inhibitor to a production well. The data review indicated that the failure occurred as a result of synergistic corrosion effects, including incompatibility between the scale inhibitor chemical and the metallurgies of the block (13Cr SS) and tubing (carbon steel). The analysis showed that while each of the relevant corrosion mechanisms (oxygen corrosion, galvanic and localised corrosion) may not be the root cause for the failure individually, in combination they proved detrimental to system integrity. The study also highlighted that while chemical inhibitor compatibility testing with appropriate flow-wetted metallurgies is common practice, the environment and configuration used for testing is not always representative of the field conditions or specific process operations (e.g., oxygen ingress due to unblanketed tanks, presence of dissimilar materials). In the present case, for example, the most significant oxygen sources were found to be the dissolved oxygen in the tap water used to mix the scale inhibitor to make up the final formulation; and the glycol blended into the product to give it ‘winterised’ properties. Lastly, the paper summarises the recommendations that were put forth to address the issue, such as evaluation of different metallurgies, a more suitable scale inhibitor and implementation of process monitoring, especially of oxygen levels.
Necessity of structured exercise training program and its feasibility on physical capacity and health status with post COVID-19 syndrome patients
Authors: kumbhare Ruhi , VARDHAN VISHNU
Published: June 2021

Corona virus disease 2019 (COVID-19) is widespread and has become a global public health emergency. The disease's outbreak was recently announced by the World Health Organization. Pulmonary Rehabilitation has been shown to improve patients' quality of life, function, and well-being with Chronic Respiratory Diseases Recently there have been various guidelines and consensus available for Pulmonary Rehabilitation in Post - COVID patients who have been discharged from other respiratory conditions. There is a limited number of literatures on the effect of exercise program on physical fitness and health status of patients with Post COVID 19 syndrome. The current study therefore uses the available evidence in COVID 19 patients to modify an exercise program and apply it to patients with COVID syndrome. The Central Trial Registry of India (CTRI) registration number for this trial is REF/2021/06/044205.
High fructose and streptozotocin induced diabetic impairments are mitigated by Indirubin-3-hydrazone via downregulation of PKR pathway in Wistar rats
Authors: Udumula Mary , Mangali Sureshbabu , Kalra Jaspreet , Dasari Deepika , Goyal Srashti , Krishna Vandana , Bollareddy Srivarsha Reddy , Sri Dharamrajan , Dhar Arti , Bhat Audesh
Published: June 2021

Background: Metabolic disorders are becoming more common in young population due to increased consumption of carbohydrate rich diet, lack of physical activity and stress. Fructose is used as a sweetener in many carbonated beverages and is a known inducer of oxidative stress and hypertension. Up-regulation of the double-stranded RNA-dependent protein kinase (PKR) causes impairment in insulin signaling pathway and metabolic dysfunctions in type 2 diabetes mellitus. In the present study we investigated the role of PKR and associated pathways in high fructose (HF) and streptozotocin (STZ) induced diabetes and whether indirubin-3-hydrazone (IHZ), a novel PKR inhibitor can reverse the HF and STZ induced diabetic impairments in Wistar rats.Methods: Diabetes was induced by feeding rats 20% high fructose in drinking water for 6 weeks and by giving a single dose of STZ (35mg/kg., i.p) at the end of week 5. Glucose and lipid levels were measured by using assay kits. Expression of PKR and its downstream genes were determined by immunohistochemistry, qRT-PCR and western blotting techniques. Histo-pathological studies were performed using H&E staining. Fibrosis was detected in insulin sensitive tissues and organs using Sirius red and Masson’s trichrome staining and apoptosis by TUNEL assay. Results and Conclusion: HF and STZ induced hyperglycemia, fibrosis, oxidative stress, and inflammation in liver, pancreas, skeletal muscle and adipose tissue are mediated via PKR pathway and its downstream effectors, and these effects were attenuated by PKR inhibitor IHZ. Thus, inhibition of PKR can protect insulin sensitive organs and tissues from HF induced diabetic impairments via the inhibition of c-Jun N-terminal kinase (JNK) pathway.
Reduced-order disturbance observer based adaptive reaching law control for discretized MIMO systems with unmatched uncertainties
Authors: Wang Cong , Xia Hongwei , Wang Yanmin , Ren Shunqing
Published: June 2021

In this paper, an adaptive discrete-time sliding mode control based on reduced-order disturbance observer is proposed for discretized multi-input multi-output systems subjected to unmatching condition. By using the designed discrete reduced-order disturbance observer, a new sliding surface is constructed to counteract the unmatched uncertainties. Then, to guarantee a smaller width of the quasi sliding mode domain, an adaptive reaching law is developed, whose switching gain is adaptively tuned to prevent overestimation of disturbance on the premise of ensuring the reaching condition of sliding surface; meanwhile, the ranges of the quasi sliding mode band and attractiveness region are deduced. The proposed control algorithm has low computational complexity and needs no information about the upper bound of unmatched disturbance. The simulations on the control of a bank-to-turn missile demonstrate that the proposed method can effectively reject unmatched disturbance, and provide higher accuracy in comparison with traditional methods.
Erdheim-Chester Disease with a Posterior Fossa Tumour Mimicking Neurosarcoidosis: A Case Report.
Authors: Parrado-Sánchez Laura , Alzate-Carvajal Verónica , Florez Luis Alberto Escobar , Granados-Sánchez Ana María , Lobato-Polo Javier
Published: June 2021

Erdheim-Chester disease (ECD) is a rare non-Langerhans'cell histiocytosisdescribed in 1930 by Jakob Erdheim and William Chester, it can present as a multisystemic entity that forms xanthogranulomas which are foamy histiocytes surrounded by fibrotic tissue. Lesions are commonly located in long bones, central nervous system (CNS), cardiovascular system, lungs, kidneys and skin. The CNS is involved in approximately 50% of cases and can compromise both extra or intra-axial structures and therefore can mimic schwannomas or meningiomas, amongst other mass lesions [2, 9]. Clinical presentation will differ from patient to patient thus diagnosis depends greatly in imaging, immunohistochemistry and genetic findings within the pathology analysis [4]. The pathogenesis of this disease remains unknown. It is most commonly found in the middle-aged male population [1, 8]. Here, we present a case of a middle-aged woman with an extra-axial lesion that was initially considered to be neurosarcoidosis proving the diagnostic challenge this entity implies.
BRCA 1/2 Mutation Spectrum Analysis in South Asia: A Systematic Review
Authors: Kharel Sanjeev , Shrestha Suraj , Yadav Siddhartha , Shakya Prafulla , Hirachan Suzita , Baidya Sujita
Published: June 2021

Background: Breast cancer (BC) is the most common form of all cancers among Asian females. Mutations in BRCA1/BRCA2 gene are observed in BC cases and also largely increases the lifetime risk of having BC. Because of the paucity of high-quality data on the molecular spectrum of BRCA mutations in South Asian populations, we aimed to explore the spectrum of BRCA gene mutation among the South Asian Population.Methods: A systematic literature search of electronic databases like PubMed, EMBASE, and Google Scholar on BRCA1 and BRCA2 gene mutation spectrum was carried out for peer-reviewed articles providing information on the spectrum of either BRCA1 or BRCA2 gene mutation on South Asian women with any form of breast cancer.Results: Twenty studies were selected for review from four South Asian countries showing similar BRCA1/2 gene mutation patterns. 185delAG mutation in exon 2 in BRCA1 was the most common recurrent mutation and founder mutation found. Various intronic variants, variants of unknown significance, large genomic rearrangements (LGRs) and polymorphisms are also described in some studies. Conclusions: The prevalence of BRCA1 mutations is higher than BRCA2 mutations in the South Asian population with a wide variation among different countries and ethnicities. The knowledge of various population-specific mutations in these cancer susceptibility genes can help provide efficient strategies for genetic testing.
The Cognitive Effectiveness of High-Intensity Interval Training (HIIT) for Individuals of Methamphetamine Dependent: A Study Protocol for a Randomized Controlled Trial
Authors: Shen Menglu , Yang Suyong , Lu Songting , Zhu Dong
Published: June 2021

IntroductionCognitive deficit is a common syndrome of methamphetamine (MA) dependence, it relates to decision-making, control ability, and social functioning. High-Intensity Interval Training (HIIT) is a training technique that requests people to work out at full intensity during a short period. A number of studies have already shown the potential effects of HIIT on cognitive roles. A number of studies have already shown the potential effects of HIIT on cognitive function. The purpose of this trial is to evaluate the cognitive effects of HIIT on the individuals of MA dependent. Methods and analysis240 individuals of MA dependent are randomly assigned to High-intensity Interval Training group (HIIT), Moderate-intensity Continuous Training group (MICT) and Control group (CON) respectively. HIIT consists of a 24-minute exercise of high-intensity interval training on a treadmill. MICT consists of a 1-hour body-mind exercise. CON remains their traditional intervention. The experimental period will be 12 months, with 3 interventions weekly for the first 6 months and follow-up for the next 6 months. All subjects will be given both physical and cognitive tests at baseline, after intervention and follow-up. The cognitive performances will be compared by a mixed-model analysis for repeated-measures.DiscussionHIIT training may reduce illicit drug cravings among individuals of MA dependent, it indicates that HIIT has better effect on cognitive functions such as memory and executive function for individuals of MA dependent.Trial Registration﻿ChiCTR, ChiCTR2000032492, Registered on Aril 30, 2020, Prospective registration, http://www.chictr.org.cn/edit.aspx?pid=52127&htm=4.
ECG with Prior Myocardial Infarction Pattern or acute ST-T Pathology is Associated with Death in Critically Ill COVID-19 Patients
Authors: Rosen Jacob , Noreland Maria , Stattin Karl , Lipcsey Miklós , Frithiof Robert , Malinovschi Andrei , Hultström Michael
Published: June 2021

Background: We investigated the prevalence of ECG abnormalities and their association with mortality, organ dysfunction and cardiac biomarkers in a cohort of COVID-19 patients admitted to the intensive care unit (ICU).Methods: This cohort study included patients with COVID-19 admitted to the ICU of a tertiary hospital in Sweden. ECG, clinical data and laboratory findings during ICU stay were extracted from medical records and ECGs obtained near ICU admission were reviewed by two independent physicians. Results: Eighty patients had an acceptable ECG near ICU-admission. In the entire cohort 30-day mortality was 28%. Compared to patients with normal ECG, among whom 30-day mortality was 16%, patients with ECG fulfilling criteria for prior myocardial infarction had higher mortality, 63%, odds ratio (OR) 9.61 (95% confidence interval (CI) 2.02-55.6) adjusted for Simplified Acute Physiology Score 3 and patients with ST-T abnormalities had 50% mortality and OR 6.05 (95% CI 1.82-21.3) in univariate analysis. Both prior myocardial infarction pattern and ST-T pathology were associated with need for vasoactive treatment and higher peak plasma levels of troponin-I, NT-pro-BNP (N-terminal pro-Brain Natriuretic Peptide), and lactate during ICU stay compared to patients with normal ECG. Conclusion: ECG with prior myocardial infarction pattern or acute ST-T pathology at ICU admission is associated with death, need for vasoactive treatment and higher levels of biomarkers of cardiac damage and strain in severely ill COVID-19 patients, and should alert clinicians to a poor prognosis.Trial registration: ClinicalTrials ID: NCT04316884. Registered 20 March 2020, https://clinicaltrials.gov/ct2/show/NCT04316884.
Temporal Dynamic Analysis of Land-use Change and its Economic Evaluation During a 21-year Period in a Diverse Land-use Configuration
Authors: Khiavi Hossein Talebi , Namini Seyyede Khamsa Asbaghian , Asaadi Mohammad Ali , Mostafazadeh Raoof
Published: June 2021

Investigating the rate and the process of land-use change and its economic effects during the last years are among the main bases of land management in the future. East Meshgin region in Ardabil province is one of the agricultural production centers, where the construction of the Sabalan dam developed the agricultural activities. In this research, the six land uses, including rangeland, orchard, agriculture, bare land, outcrop, and water bodies during the years of 1998–1999, were classified using Landsat imagery. Also, the single and comprehensive dynamic land-use change indices were employed to compute the rate and process of land-use change. The land-use change matrix is developed in three time periods (1998–2003, 2003–2008, and 2013–2019). The economic evaluation of land use has been conducted during this period. The results showed that the highest rate of land-use change was converting the rangeland to bare lands. While in the period of 2008–2013, the highest rate of land-use change was rangeland conversion to agriculture lands that has caused increased net income by 4027,258 $. The collected data relates to the total period also confirms the change of rangeland use to bare lands. Also, the results of the single dynamic land-use change model show that in each period, the most change was related to water body land use. Among other land-uses, the highest rate of change was related to agricultural land use between 2013–2019 in the period of Sabalan dam operation. This study is performed to facilitate policymakers, planners, and other development stakeholders in this sector to adopt the best option for land-use management and sustainable land development.