bluuebunny/crossref_metadata_2025 huggingface dataset:
Conditioned medium of IGF1-induced synovial membrane mesenchymal stem cells increases chondrogenic and chondroprotective markers in chondrocyte inflammation
Authors: Marlina Marlina , Rahmadian Rizki , Armenia Armenia , Aviani Jenifer Kiem , Sholihah Ika Adhani , Kusuma Hanna Sari Widya , Azizah Alya Mardhotillah , Elida Nur , Widowati Wahyu
Published: June 2021

Recently, mesenchymal stem cells (MSCs) have been the most explored cells for cell therapy for osteoarthritis (OA) that can be obtained from various sources. Synovial membrane MSCs (SMMSCs) provide best potential for OA therapy, however they are not widely explored. Conditioned medium of SMMSCs (SMMSCs-CM) rich in growth factors and cytokines can inhibit apoptosis and increase chondrocytes cell proliferation. The aim of the present study was to determine growth factors content in SMMSCs-CM as well as the chondrogenic and chondroprotective markers expression in OA model after insulin-like growth factor (IGF)1-induced and non-induced SMMSCs-CM treatments. Chondrocyte cell line (CHON002) was induced by IL1β as OA model (CHON002 with IL1β (IL1β-CHON002)) and treated with SMMSCs-CM with or without IGF1 induction to determine its effectiveness in repairing OA cells model. ELISA was used to assay BMP2, fibroblast growth factor 18 (FGF18) and transforming growth factor (TGF) β1 (TGFβ1) levels in SMMSCs-CM, matrix metalloproteinase (MMP) 13 (MMP13) and a disintegrin and metalloproteinase with thrombospondin motif 4 (ADAMTS4) levels in OA cells model treated with SMMSCs-CM. RT-qPCR analyses were used to investigate the gene expression of SOX9, COL2, and COL10. CM from SMMSCs cultured and induced by IGF1 150 ng/mL was the most effective concentration for increasing the content of growth factor markers of SMMSCs-CM, which had successfully increased negative cartilage hypertrophy markers (SOX9 and COL2) and reduced hypertrophy markers (COL10, MMP13, and ADAMTS4). Preconditioning with IGF1 has better and very significant results in lowering MMP13 and ADAMTS4 levels. The present study supports IGF1 pre-conditioned SMMSCs-CM to develop a new therapeutic approach in OA improvement through its chondrogenic and chondroprotective roles.
Multi‐agent based protection scheme using current‐only directional overcurrent relays for looped/meshed distribution systems
Authors: Ataei Mohammad Ali , Gitizadeh Mohsen , Lehtonen Matti , Razavi‐Far Roozbeh
Published: June 2021

The complexity of the design of the protection system using directional over current relays, for modern power distribution systems has been increased due to the looped/meshed operation and the penetration of distributed generations. Finding a reliable and efficient protection scheme that can be easily implemented in these distribution systems is a major challenge. An efficient solution could be the use of artificial intelligent‐based multi‐agent systems. This paper proposes a novel distributed intelligent based multi‐agent protection scheme, which makes use of current‐only directional over current relays as agents for detecting and locating faults and isolating faulty areas (lines/busbars) in the distribution systems. All agents can make on‐board decisions by exchanging binary data, and do not need a control centre, so the safety of the protection system against one‐point failures and cyber‐attacks is increased. The proposed scheme does not need to exchange analogue data, and, therefore, it prevents the high bandwidth communication links. Moreover, it is free from the traditional coordination between relays. This scheme is implemented on the IEEE‐14 bus and IEEE‐30 bus test systems with the distributed generations and several scenarios have been simulated to evaluate its performance.
Complex eigenvalues of natural TM‐oscillations in an open resonator formed by two sinusoidally corrugated metallic strips
Authors: Vinogradova Elena D. , Kobayashi Kazuya
Published: June 2021

The diffraction of an E‐polarized plane wave from two finite sinusoidal gratings is investigated by a rigorous approach, based on the Method of Analytical Regularization. This allows us to analyse the problem in a wide frequency band without limitations on the depth of the sinusoidal corrugation, the wave size of the gratings, or their relative location. The homogeneous version of the equations obtained is used for accurate computation of the complex eigenvalues in an open resonator of Fabry–Perot type with sinusoidally corrugated strips. In the calculations, two types of structures were used: one is formed by parallel translation of the sinusoidally corrugated strips and the other is obtained by rotation of one of the strips in the first structure. For each relative location of the corrugated strips, the resonance excitation of the structure by an obliquely incident E‐polarized plane wave is considered. Based on the calculation of the surface current density for different incidence angles, their specific values for optimal excitation of the complex modes are established.
Flexible control for power‐sharing in the CHB‐based SST under voltage unbalance conditions
Authors: Babaei Mehdi , Ghandehari Reza
Published: June 2021

Solid‐state transformers (SSTs) have flexible capabilities to improve the power quality issues. These improvements impose disturbances into the SST converters that require proper control algorithms. In this paper, the problems of the unequal active power flow in different phases of the SST due to the grid voltage unbalance conditions and the negative sequence current injection are discussed, and an effective method is proposed to equally sharing the active powers between the SST clusters by creating an optimum zero sequence current. Based on the power dependencies, an analytical vector for the zero‐sequence current is proposed, which can equally share the power among the SST clusters and balance the HVDC‐link voltages. Also, the proposed control strategy by using PIR controllers can achieve the zero‐sequence current based on a direct current control method. The provided equal power‐sharing among the clusters is kept in the considerable unbalanced voltage of the grid and prevents the SST outage during faults. The simulation and experimental results confirm the proposed control method to equalise the power‐sharing among the SST clusters and voltage equalisation of the HVDC‐links while the SST tries to improve the grid voltage unbalance and in the fault conditions of the grid.
JMRPE‐Net: Joint modulation recognition and parameter estimation of cognitive radar signals with a deep multitask network
Authors: Zhu Mengtao , Zhang Ziwei , Li Cong , Li Yunjie
Published: June 2021

The newly developed cognitive radar (CR) can implement flexible work modes defined with a set of mode definition parameters. Each definition parameter can employ its modulation type and corresponding optimised modulating values. Automatic recognition and analysis of CR work mode are significant challenges for electromagnetic reconnaissance applications. In this article, a deep multitask neural network is proposed for Joint automatic Modulation Recognition and modulation Parameter Estimation (JMRPE‐Net) for the emerging task of CR signals analysis. The proposed JMRPE‐Net consists of a fork‐shaped architecture in which three cascaded convolutional layers act as a shared module for the extraction of common features followed by multiple branches of long short‐term memory layers with the attention mechanism for task‐specific features extraction. The proposed network can receive a sequence of CR pulse signals as input and parallelly perform automatic modulation recognition (AMR) and modulation parameter estimation tasks for multiple work mode definition parameters. Extensive experiments are conducted based on simulated radar intermediate frequency signals with consideration of imperfections of real‐world electromagnetic environments. The experimental results validate the superiority of the proposed JMRPE‐Net against the existing state‐of‐the‐art single task AMR methods or parameter estimation methods.
ALMA observations of the variability of the quiet Sun at millimeter wavelengths
Authors: Nindos A. , Patsourakos S. , Alissandrakis C. E. , Bastian T. S.
Published: June 2021

Aims. We address the variability of the quiet solar chromosphere at 1.26 mm and 3 mm with a focus on the study of spatially resolved oscillations and transient brightenings, which are small, weak events of energy release. Both phenomena may have a bearing on the heating of the chromosphere.

Methods. We used Atacama Large Millimeter/submillimeter Array (ALMA) observations of the quiet Sun at 1.26 mm and 3 mm. The spatial and temporal resolution of the data were 1 − 2″ and 1 s, respectively. The concatenation of light curves from different scans yielded a frequency resolution in spectral power of 0.5−0.6 mHz. At 1.26 mm, in addition to power spectra of the original data, we degraded the images to the spatial resolution of the 3 mm images and used fields of view that were equal in area for both data sets. The detection of transient brightenings was made after the effect of oscillations was removed.

Results. At both frequencies, we detected p-mode oscillations in the range 3.6−4.4 mHz. The corrections for spatial resolution and field of view at 1.26 mm decreased the root mean square (rms) of the oscillations by a factor of 1.6 and 1.1, respectively. In the corrected data sets, the oscillations at 1.26 mm and 3 mm showed brightness temperature fluctuations of ∼1.7 − 1.8% with respect to the average quiet Sun, corresponding to 137 and 107 K, respectively. We detected 77 transient brightenings at 1.26 mm and 115 at 3 mm. Although their majority occurred in the cell interior, the occurrence rate per unit area of the 1.26 mm events was higher than that of the 3 mm events; this conclusion does not change if we take into account differences in spatial resolution and noise levels. The energy associated with the transient brightenings ranged from 1.8 × 1023 to 1.1 × 1026 erg and from 7.2 × 1023 to 1.7 × 1026 erg for the 1.26 mm and 3 mm events, respectively. The corresponding power-law indices of the energy distribution were 1.64 and 1.73. We also found that ALMA bright network structures corresponded to dark mottles or spicules that can be seen in broadband Hα images from the GONG network.

Conclusions. The fluctuations associated with the p-mode oscillations represent a fraction of 0.55−0.68 of the full power spectrum. Their energy density at 1.26 mm is 3 × 10−2 erg cm−3. The computed low-end energy of the 1.26 mm transient brightenings is among the smallest ever reported, irrespective of the wavelength of the observation. Although the occurrence rate per unit area of the 1.26 mm transient brightenings was higher than that of the 3 mm events, their power per unit area is smaller likely due to the detection of many weak 1.26 mm events.
The vertical cities: reality or utopia of the future
Authors: Novikov Stepan , Gimazutdinova Eliza
Published: June 2021

Growth of population affects the increase in demand for development of new areas. The article discusses current problems and trends in the development of vertical cities of the future. The last decade has seen the consolidation of the urban environment and the transition of urban planning from horizontal to vertical. The structure of future vertical cities minimizes land use and contributes to solving environmental problems and de-urbanization. The authors analyze the origin of «utopia» word and its meaning in the concepts of utopian cities since ancient times. The formation of a comfortable vertical city is a utopia aimed at turning it into the reality of the future. A general analysis of space-planning and architectural solutions of modern concepts helped to formulate the basic principles of creating a vertical city. The identified criteria of the architectural space will allow humanity to live in a comfortable environment, including the period of forced critical conditions. During the research, we presented a hypothesis of the emergence of vertical cities in the world and in Russia. The study can become the basis for forecasting the processes of urbanization and deurbanization, also as a concept creation for the development of a sustainable model of the future vertical city.
Methodological principles of planning reorganization of the city of Naberezhnye Chelny during the development of the Master Plan-2022
Authors: Dembich Alexander , Zakirova Yulia , Orlova Nataliia , Khakimova Tansylu
Published: June 2021

The purpose of the study is the definition of scientifically based principles of planning reorganization of the city of Naberezhnye Chelny. The main results of the study are the development of a program of urban development of the city territory on the basis of the identified problems and limitations, the definition of key tasks in the spatial and territorial development of the city of Naberezhnye Chelny. Significance of the results for architecture and urban planning consists in the fact that the methodological principles of the planning reorganization of the city as the basis for the development of the strategic master plan of the city of Naberezhnye Chelny are revealed.
Synthesis of the technique of academic architectural drawing and architectural fantasy in composite openings as an invariant of professional training of future architects
Authors: Rafikov Ilias
Published: June 2021

The article reveals the compositional specificity of architectural drawing from nature and from the standpoint of including the aesthetic category – «fantastic» in the creative learning process. In this regard, the content, methods and forms of teaching in the variety of compositional solutions of architectural drawing are considered.
Research of the stress-strain state of a reinforced concrete beamless floor
Authors: Mirsayapov Ilshat , Khorkov Evgeny , Minzianov Rustam
Published: June 2021

In the article, the authors present the results of a study of a flat reinforced concrete beamless floor of an existing building. The experiment consisted of loading a slab in span with water tanks. There were 15 loading stages in total, on average 4 kN. During the experiment, data was obtained on the relative deformations of concrete and reinforcement in the span and on the support. Also, observations of the growth of vertical deformations and the growth of cracks in the span were introduced.
Use of Filled Bioplastics in Construction
Authors: Safin Ruslan , Galyavetdinov Nour , Salimgaraeva Regina , Ilalova Guzel , Saerova Ksenia
Published: June 2021

Polymers and associated composite materials play an increasingly prominent role among structural materials. The relevance of the use of bioplastics as an alternative to synthetic polymers increases year by year. In this regard, the paper describes the production of a ligno-filled polymer material based on polyhydroxyalkanoates to be used in the production of building materials. The studies allowed us to produce the material from wood hydrolyzates. The highest yield of reducing substances in course of pine sawdust hydrolysis with 4% sulfurous acid occurred at 170°C. To obtain a biopolymer in liquid wood hydrolyzate medium, the Cupriavidus necator strain was used, which after 50 hours of cultivation gave a biopolymer yield of up to 15 g/l. The studies of the strength characteristics of the composite based on the obtained bioplastic and dried solid wood hydrolysates allowed us to produce a balanced composition for subsequent use in construction.
Cost management of a construction company based on functional cost analysis
Authors: Borovskikh Olga , Evstafieva Alsu , Marfina Ludmila
Published: June 2021

In conditions of environmental instability and uncertainty, one of the factors for the effective functioning and development of a construction company is high-quality and continuous cost management. The cost management process is aimed at maximizing profits by increasing the efficiency of the use of all resources. It requires constant monitoring to make adjustments to the planned costs and their amounts. Cost management is impossible without careful analysis. Along with the traditional methods of cost management, it is advisable for construction companies to apply functional cost analysis, which is an effective tool for optimizing costs and the quality of production functions performance. The research studies a construction company. Particular attention in the study is paid to indirect costs due to an increase in their share in the structure of the construction products cost. Within the framework of the functional cost analysis, an ABC analysis was carried out and a Pareto curve was modelled. It allowed us to focus on the allocated cost areas and classify the processes into main, basic and supportive ones. The significance of the identified processes was determined using the paired comparisons method. The results obtained allow us to draw a conclusion about the correspondence of the share of cost items and their significance for the analyzed construction company. The research materials are of interest and practical importance for the CEOs of construction companies.
The practical barriers to kickstarting the innovation and investment in the sphere of construction in Russian Federation
Authors: Asaul Anatoly , Asaul Maksim , Drozdova Irina , Levin Yuri , Trushkovskaya Ekaterina
Published: June 2021

We have identified the main issues in introducing innovation into a construction project. The solution is realized through the study of both objective and subjective obstacles to the introduction of the innovative technologies in the investment - construction cycle, which is treated as a single process, because the economic effects of innovation can be evaluated only within the full life cycle of a building. We created a highly interconnected financial model of the compounding effects of innovation in the construction industry. We present the Russian construction market’s challenges and feedback loops in innovation by using graph theory and complex analysis. The article presents the method developed in the scientific school «Methodological problems of the economic effectiveness of regional construction clusters as a self-ordering system» that shows the algorithmic consistency and transparency of evaluating the effectiveness of the innovations.

The described method can be used in a large array of scientific and theoretical tasks: from the replication of the method to other types of economic activity to the synthesis of methods and models for identifying key areas of innovation activity. It can also be used to build a method for assessing the innovative potential of a project.
Testing heat supply networks for heat losses
Authors: Mozgova Anna
Published: June 2021

The scope of operations of the branch where the survey was carried out is: transmission and distribution of heat and heating medium to consumers through heat supply networks, maintaining the proper quality and amount of thermal power and heating medium supplied, ensuring contractual activities with heat consumers, as well as control of compliance with the consumption regimes stipulated by contracts, ensuring payments from consumers for supplied heat and heating medium, development and implementation of measures ensuring maximum efficiency of heat supply activities. The purpose of the work performed is to determine the actual heat losses through the thermal insulation of the surveyed heating networks and to compare them with normative values. The article presents an analysis of materials on the heat supply system; test findings for actual heat losses in a heat supply pipeline; calculation of actual heat losses for each section and their adjustment to average annual operating conditions of the given heat supply network; comparison of calculation results with normative characteristics. The test findings are used in developing the output performance for the «Heat Loss» indicator and in setting of norms for operating heat losses. The heat supply source for the heat pipeline is the CHP-plant. The pipelines are routed above ground on high and low supports, as well as in crawl ways. The thermal insulation of the pipelines is mainly made of 50 mm blankets of mineral wool and is typical for heat supply networks. In overhauls of heat supply networks, polyurethane foam is partly used as thermal insulation.
Method for optimizing the number of glass-fiber reinforced plastic rebars in concrete structures
Authors: Nasybullin Ranel , Akhmadiev Fail , Bakhareva Olga
Published: June 2021

Innovations in the construction industry have led to a change in the technological structure, the use of end-to-end technologies, innovative materials, information management and the need for new technical, technological and managerial solutions. The research problem is the optimal placement of glass-fiber reinforced plastic bars in concrete structures. It took several steps to solve the research problem: 1) development of an algorithm for solving the design problem in TEKLA Structures; 2) performing of calculations based on the finite element method in LIRA-SAPR, which were further reproduced in Rhinoceros and Grasshopper (based on interoperability in a single BIM environment); 3) implementation of the optimization algorithm using the parametric optimization method; 4) A practical calculation of determining the optimal values of the loads of glass-fiber reinforcement in the slab on the example of a typical design problem of a structural element of a construction facility; 5) calculation of positive economic effect. The conclusion is that the algorithm can be used in the practice of building design.
Technology for developing the professional competence of physical education teachers in architecture and construction university
Authors: Garifullin Ruslan , Imangulov Rais , Arkhipov Evgeniy , Ishmukhametova Naila , Nabiullin Ravil
Published: June 2021

The objective of this paper is to investigate the possibility of forming the professional competence of physical education teachers in a university of architecture and engineering. At the beginning of the experiment the baseline level of teachers' professional competence was determined in order to form the control and experimental groups among them. In the control group the formation of competence of teachers was carried out by taking professional development courses according to the «standard» program, according to which the participants were given lectures, seminars on various modules of the program, having to complete a course with a final qualifying paper on a selected topic. Teachers in the experimental group were trained according to the professional development programme, taking into account the developed model of competence formation. At the end of the training the previously studied indicators were tested in both groups and the data obtained was then compared. As a result, it was found that the professional competence level of teachers in the experimental group increased significantly compared to this in the control group. Thus, it showed that to be able to form teachers' professional competence «standard» professional development programmes currently implemented by Kazan State University of Architecture and Engineering are not enough. For effective formation of competence it is necessary to have a special technology of teachers' training, which is implemented in the developed pedagogical model of formation of teachers' professional competence.
The evaluation of sustainable development for the manufacturers of construction-polymer products
Authors: Gareeva Nailya , Starodubova Anna , Romanova Anna
Published: June 2021

The authors studied the indicators that impacted on the sustainable development of industrial enterprises and developed the comprehensive method for their evaluation. This methodology consists of 4 stages: data collection, evaluation of indicators, identification of deviations from the principles of sustainable development, recommendations for adjusting the business model and the network structure of cooperation. A scoring evaluation of the indicators of sustainable development for enterprises is proposed. The authors selected 12 indicators and grouped them according to the economic, environmental and social principles of sustainable development. The study identified seven classes of sustainability for enterprises and their characteristics. If enterprises had higher score, it meant they had higher class and higher sustainability, and vice versa. The method was tested on the example of the evaluation of production of construction-polymer products for 2020. The proposed methodology will enable enterprises to independently evaluate the level of sustainable development. It will also show deviations from the norm separately for each principle of sustainable development. The perspective of this study is that it is possible to develop recommendations for each class of sustainable development.
Assessment of innovation risks in the context of sustainable development
Authors: Zaynullina Dilyara
Published: June 2021

It is obvious that any innovative activity is associated with risk, but the functioning of Russian innovative companies is the subject to even greater uncertainty. It is due to the lack of government support, the difficulty of forecasting the Russian economy, the influence of external factors, etc. Uncertainty in the context of sustainable development is a source of risk, and it should be reduced by obtaining information, at best, trying to lower uncertainty to zero by obtaining reliable and accurate information. The purpose of this study is a qualitative assessment of the innovative project’s risks of various types of activities implemented in the Republic of Tatarstan. The author conducted an expert survey in the field of innovative economics: representatives of business and science. The expert survey covered the following main areas: qualitative risk assessment of a group of innovative projects and the potential impact of risks on the formation of management strategies that integrate risk management methods that companies plan to use. According to the results of the analysis of the expert survey, it is clear that for innovative projects in the service sector, the most dangerous are marketing, organizational, credit and technical risks. The technical risk is the most critical for innovative projects in the manufacturing industry, as well as the marketing, natural and climatic risk and the risk of lost. As for the extractive industry, technical and natural-climatic risks have the highest probability of occurrence.
Investigation of factors influencing the operational characteristics of traction transformers
Authors: Yusupov Dilmurod , Kutbidinov Odiljon , Samadov Shakhboz , Abdullaev Eldor
Published: June 2021

This article presents the results of visual inspections and a brief statistical analysis of the data obtained in order to identify the observed defects in traction transformers of ODTsE 5000 / 25 B and OTsR 5600/25 types in operation in the railway system. The analysis revealed that the main parameters that determine the operational characteristics of traction transformers are windings and insulation. Recommendations for the prevention of faults in traction transformers and increase their service life have been developed.
Numerical investigations of the impact of buffer germanium composition and low cost fabrication of Cu2O on AZO/ZnGeO/Cu2O solar cell performances
Authors: Chevallier Christyves , Bose Sourav , Ould Saad Hamady Sidi , Fressengeas Nicolas
Published: June 2021

Numerical simulations of AZO/Zn1−xGexO/Cu2O solar cell are performed in order to model for the first time the impact of the germanium composition of the ZnGeO buffer layer on the photovoltaic conversion efficiency. The physical parameters of the model are chosen with special care to match literature experimental measurements or are interpolated using the values from binary metal oxides in the case of the new Zn1−xGexO compound. The solar cell model accuracy is then confirmed thanks to the comparison of its predictions with measurements from the literature that were done on experimental devices obtained by thermal oxidation. This validation of the AZO/Zn1−xGexO/Cu2O model then allows to study the impact of the use of the low cost, environmental friendly and industrially compatible spray pyrolysis process on the solar cell efficiency. To that aim, the Cu2O absorber layer parameters are adjusted to typical values obtained by the spray pyrolysis process by selecting state of the art experimental data. The analysis of the impact of the absorber layer thickness, the carrier mobility, the defect and doping concentration on the solar cell performances allows to draw guidelines for ZnGeO/Cu2O thin film photovoltaic device realization through spray pyrolysis.
Specific indicator invertebrates of urbanized habitats in tributary streams of the Luján River basin (Buenos Aires, Argentina)
Authors: Fañani Agustina Belén , Cibils-Martina Luciana , Casset María Andrea , Banegas Barbara Pamela , Poretti Teresita Inés , Rocha Luciana
Published: June 2021

The increase of urbanized areas produces disturbances in rivers and streams, and its widespread effects reduce water quality and threaten aquatic biota. The aim of this study was to analyze changes in the invertebrate communities of the Luján River basin (Buenos Aires Province, Argentina) in an urbanization gradient and to determine the specific indicator taxa of urbanized habitats. Nine sampling sites were selected in the Luján River basin, distributed along a land use gradient. At each sampling site physicochemical variables of water were recorded, and invertebrate samples were collected during four seasons. A Principal Component Analysis separated three groups of sites with different urbanization conditions: low (<15%), moderate (between 15% and 60%) and high urbanization (>60%). These groups showed differences in the concentration of dissolved oxygen, suspended particulate organic matter, and nitrates. The communities changed with urbanization conditions, with a simplification of the community composition and a decrease in richness towards the lower basin (moderate and high urbanization). The IndVal method found three indicator taxa for the low urbanization sites (Heleobia sp. (Cochliopidae), Uncancylus sp. (Ancylidae) and Callibaetis sp. (Baetidae)) and three for the moderate urbanization habitats (Nematoda, Hyalella curvispina (Hyalellidae) and Chironominae). These taxa were useful to identify different disturbance conditions due to urbanization, which makes them potential bioindicators in the diagnosis and monitoring of water quality in the Luján River basin.
Study on the separation of silicon from refining slag of industrial silicon
Authors: Hou Yong , Zhang Guo-Hua , Chou Kuo-Chih
Published: June 2021

During the process of production and refining of industrial silicon, the discharged slag usually contains more than 15 mass% of metallic silicon. However, the separation of silicon from slag is very difficult due to the close density of silicon and slag as well as the high viscosity of slag, which results in the waste of resources. In the present work, the effect of Na2O addition on the separation of silicon from slag is investigated in detail. It is found that the optimum separation condition of slag and silicon is 1723 K reacting for 60 min by adding 10 mass% Na2O to the slag. Viscosity and density are two important factors affecting the separation effect of silicon from slag. The addition of Na2O reduces the viscosity of slag and promotes the separation of silicon from slag. Even if the addition of Na2O will decrease the density of slag which is detrimental to the separation of silicon, the density variation is not the determining factor affecting the separation relative to viscosity. The separation and extraction of metallic silicon from silicon slag is of great significance for improving utilization of resources and reducing environmental pollution.
Investigation of the influence of incremental sheet forming process parameters using response surface methodology
Authors: Karim Belouettar , Mohand Ould Ouali , Nasereddine Zeroudi , Sébastien Thibaud
Published: June 2021

New methods in metal forming are rapidly developing and several forming processes are used to optimize manufacturing components and to reduce cost production. Single Point Incremental Forming (SPIF) is a metal sheet forming process used for rapid prototyping applications and small batch production. This work is dedicated to the investigation of the profile geometry and thickness evolution of a truncated pyramid. The influence of process parameters during a SPIF process is also studied. A numerical response surface methodology with a Design of Experiments (DOE) is used to improve the thickness reduction and the effects of the springback. A set of 16 tests are performed by varying four parameters: tool diameter, forming angle, sheet thickness, and tool path. The Gurson-Tvergaard-Needleman (GTN) damage model is used to analyze the damage evolution during material deformation. It is found that the model can effectively predict the geometrical profile and thickness with an error of less than 4%. Furthermore, it is noticed that the forming angle is the most influential parameter on the thickness reduction and springback level. Finally, the damage evolution is demonstrated to be sensitive to the forming angle.
Inertial normal S-type Tseng’s extragradient algorithm for solution of variational inequality problems
Authors: Sahu D.R. , Singh Amit Kumar
Published: June 2021

In this paper, we introduce inertial Tseng’s extragradient algorithms combined with normal-S iteration process for solving variational inequality problems involving pseudo-monotone and Lipschitz continuous operators. Under mild conditions, we establish the weak convergence results in Hilbert spaces. Numerical examples are also presented to show that faster behaviour of the proposed method.
Weekend and evening planned colonoscopy activity: a safe and effective way to meet demands
Authors: Afify Shimaa A. , Abo-Elazm Omnia M. , Bahbah Ishak I. , Thoufeeq Mo H.
Published: June 2021

Background and study aims Colonoscopy is the “gold standard” investigation for assessment of the large bowel that detects and prevents colorectal cancer, as well as non-neoplastic conditions. The Joint Advisory Group (JAG) on Gastrointestinal Endoscopy recommends monitoring key performance indicators such as cecal intubation rate (CIR) and adenoma detection rate (ADR). We aimed to investigate the quality of colonoscopies carried out during evening and Saturday lists in our unit and compare them against JAG standards of quality for colonoscopies.

Patients and methods We retrospectively collected and analyzed demographical and procedure-related data for non-screening colonoscopies performed between January 2016 and November 2018. Evenings and Saturdays were defined as the out-of-hour (OOH) period. We compared the outcomes of the procedures done in these against the working hours of the weekdays. We also wanted to explore whether the outcomes were different among certain endoscopists. Other factors that could affect the KPIs, such as endoscopist experience and bowel preparation, were also analyzed.

Results There were a total of 17634 colonoscopies carried out; 56.9 % of the patients (n = 10041) < 70 years old. Key Performance Indicators (KPIs) of weekday, evening, and Saturday colonoscopies regarding the CIR and ADR met the JAG standards as they were above 93 % and 24 %, respectively. Advanced colonoscopists had better KPIs when compared to the non-advanced colonoscopists, with CIR at 97.6 % vs. 93.2 % and ADR at 40.8 % vs. 26 %, respectively.

Conclusions JAG standards were maintained during colonoscopies done on weekdays, evenings, and Saturdays. Advanced colonoscopists had higher CIR and ADRs.
Prophylactic and Therapeutic Measures of Homeopathy in Epidemic and Pandemic Diseases
Authors: Yaseen Ghulam
Published: June 2021

Background The terms Epidemic and Pandemic refer to spread of infectious diseases in different countries, nations or regions. Infectious diseases have overrun millions of people in the past, as well as doing now when the world is facing current coronavirus disease 2019 (Covid-19) pandemic, which has killed more than 607,781 people till July 2020, according to the World Health Organisation. Homeopathy has played an important role in controlling epidemic and pandemic diseases distressing humanity since the time of Hahnemann who cured scarlet fever with Belladonna and served community with best treatment. This article reviews the role of homeopathy in the management and prevention of pandemic and epidemic diseases.

Methods A homeopathic literature search was performed using several bibliographic databases such as Google Scholar, PubMed and Google search engine was used for collection of all relevant information from reports, review articles, archived files and Web pages etc., published in English language till July 2020.

Results Gathered information based on scientific evidences manifested the efficacy of homeopathy using various approaches such as individualisation, Genus epidemicus and isopathy for prevention and treatment of epidemic diseases.

Conclusion Homeopathy showcased its effectiveness in reduction of mortality and morbidity in epidemics for years. Moreover, prophylactic use of Genus epidemicus for symptomatic Covid-19 cases can be inexpensive, safe and more realistic.
Endoscope-controlled Access to Thalamic Tumors using Tubular Brain Retractor: An Alternative Approach to Microscopic Excision
Authors: Sihag Rakesh , Bajaj Jitin , Yadav Yad Ram , Ratre Shailendra , Hedaoo Ketan , Kumar Ambuj , Sinha Mallika , Parihar Vijay , Swamy M. Narayan
Published: June 2021

Background Surgery for thalamic lesions has been considered challenging due to their deep-seated location. Endoscopic excision of deep-seated brain tumors using tubular retractor has been shown to be safe and effective in prior studies; however, there are limited reports regarding its use for thalamic tumors. We present our experience of endoscope-controlled resection of thalamic tumors using a tubular retractor.

Material and Methods This was a prospective observational case series done at a tertiary center specialized for endoscopic neurosurgery during the period from 2010 to 2019. Surgeries were performed under the endoscopic control using a silicon tubular retractor. Lesions were approached transcortically or trans-sulcally. Data were collected for the extent of resection, amount of blood loss, operative time, need for conversion to microscopy, and complications.

Results Twenty-one patients of thalamic masses of 14- to 60-year age underwent the surgeries. Pathologies ranged from grade I to IV gliomas. Gross total and near-total resection could be done in 42.85% of cases for each group. The average blood loss and operative time were164.04 ± 83.63 mL and 157.14 ± 28.70 minutes, respectively. Complications included a small brain contusion, two transient hemipareses, and one transient speech deficit.

Conclusion Endoscopic excision of thalamic tumors using a tubular retractor was found to be a safe and effective alternative to microscopic resection.
A New Treatment for the Reconstruction of the Medial Compartment of the Ankle: The Combined Use of Biological Materials
Authors: Lughi Marcello , Campagna Alessandro , Purpura Valeria , Bondioli Elena
Published: June 2021

Fractures, especially if articular and periarticular, are frequently associated to functional and clinical disabling outcomes and chronic pain. In particular, the injuries with loss of bone, ligament, and/or tendon tissue in which the full recovery of the wound area is not obtained are the worst anatomical/pathological conditions to heal. In this study, three different biological materials were used as regenerative approaches to rebuild the medial malleolus fracture of the ankle in which loss of bone, ligament, and tendon tissue occur. In particular, the morselized human bone tissue was combined with the human dermis decellularized, both augmented with homologous platelet-rich plasma. The magnetic resonance imaging study with contrast at the follow-up showed a signal compatible with vascularization of the tissue without sign of degeneration. Our new regenerative approach in which different biological materials were combined together showed a good choice of treatment for the reconstruction of not repairable outcome of a fracture.
Fabrication of ZnO-nanowire-coated thin-foil targets for ultra-high intensity laser interaction experiments
Authors: Calestani D. , Villani M. , Cristoforetti G. , Brandi F. , Koester P. , Labate L. , Gizzi L. A.
Published: June 2021

The coupling of ultra-intense, ultra-short laser pulses with solid targets is heavily dependent on the properties of the vacuum–solid interface and is usually quite low. However, laser absorption can be enhanced via micro or nanopatterning of the target surface. Depending on the laser features and target geometry, conditions can be optimized for the generation of hot dense matter, which can be used to produce high-brightness radiation sources or even to accelerate particles to relativistic energies. In this context, ZnO nanowires were grown on metallic, thin-foil targets. The use of a thin-foil substrate was dictated by the need to achieve proton acceleration via target normal sheath acceleration at the rear side. The chemical process parameters were studied in-depth to provide control over the nanowire size, shape, and distribution. Moreover, the manufacturing process was optimized to provide accurate reproducibility of key parameters in the widest possible range and good homogeneity across the entire foil area.
Study on the propagation velocity of methane/air pleated flames based on image processing and fractal interpolation
Authors: Wang Haiyan , Zhang Lei , Zhang Junpeng , Wang Peipei , Hu Lang , Guo Zengle
Published: June 2021

A self-developed gas explosion experimental system was used to detonate methane/air mixtures of different concentrations by different ignition methods, and the propagation processes of spherical flames and irregular flames formed by the explosions were recorded using a high-speed camera. Based on image processing and the fractal interpolation method, the propagation velocity of the explosion-stretched flame was calculated. The flame image was processed in MATLAB to optimize the traditional calculation method. Based on fractal theory, a fractal interpolation function was constructed to calculate the propagation velocity at each point on the front of the spherical stretched flame, and then, the laminar combustion velocity of the methane/air mixed balloon flame was obtained. Compared with the numerical simulation and empirical formula, the error in the laminar flame velocity was less than 0.2%, which verifies the correctness of the image processing and fractal interpolation method to calculate the flame propagation velocity. Using this method, the propagation velocity of the irregular fold stretching flame of the methane/air mixture was calculated, and the propagation velocity at each point along the flame front was obtained. The reason why the flame speed of the gas explosion with a high-temperature source was higher than the flame speed of the gas explosion with an electric spark was preliminarily explained.
Noise investigation in a spin-based four-qubit GaAs block of self-assembled quantum dots
Authors: Prousalis Konstantinos , Iliadis Agis A. , Evangelou Evangelos K. , Konofaos Nikos
Published: June 2021

Optically controlled self-assembled quantum dots have received substantial attention in the quantum computing area, as techniques for initializing, manipulating, and reading out single spin qubits have been demonstrated in essence. The electron-spin coherence and hole-spin coherence are limited due to noisy quantum effects, and there is a significant need for further evaluation and investigation studies. In this work, the behavior of charge noise and spin noise for a fundamental logic unit of four qubit embedded in an AlAs/GaAs heterostructure is reported based on the modeling and simulation approach in the atomic level to provide a more in-depth analysis and evaluation of quantum noise. The numerical calculations are based on reliable simulation methods, which are consistent with experimental results. The approach presented here can become the basis for scaled-up advanced simulations expanding to larger logical blocks of qubits.
Free silver nanoparticles doped by potassium: Work-function change in experiment and theory
Authors: Mikkelä Mikko-Heikki , Jänkälä Kari , Huttula Marko , Björneholm Olle , Tchaplyguine Maxim
Published: June 2021

The composition-dependent change in the work-function (WF) of binary silver–potassium nanoparticles has been studied experimentally by synchrotron-based x-ray photoelectron spectroscopy (PES) and theoretically using a microscopic jellium model of metals. The Ag–K particles with different K fractions were produced by letting a beam of preformed Ag particles pass through a volume with K vapor. The PES on a beam of individual non-supported Ag–K nanoparticles created in this way allowed a direct absolute measurement of their WF, avoiding several usual shortcomings of the method. Experimentally, the WF has been found to be very sensitive to K concentration: Already at low exposure, it decreased down to ≈2 eV—below the value of pure K. In the jellium modeling, considered for Ag–K nanoparticles, two principally different adsorption patterns were tested: without and with K diffusion. The experimental and calculation results together suggest that only efficient surface alloying of two metals, whose immiscibility was long-term textbook knowledge, could lead to the observed WF values.
A novel method for optimizing the topography parameters of mechanical mating surfaces focus on performance and cost requirements
Authors: Wang Yunlong , Mu Xiaokai , Yue Cong , Sun Wei , Liu Chong , Sun Qingchao
Published: June 2021

The surface machining precision of parts is closely related to the contact performance between the mating surfaces of the assembly, and it will create a waste of resources to ensure the system performance by excessively improving the machining accuracy of parts. In order to ensure the high performance of the system on the basis of low cost and low manufacturing precision, this study proposes a method to achieve the goal by adjusting the surface topography parameters in the design phase. First, the surface topography information of the measured parts was characterized by different parameters to realize the parametric expression of the surface topography; second, the mechanical properties of the mating surface with different surface topographies were obtained by numerical analysis and experimental methods; third, the functional relationship models between different surface topography parameters and the contact performance of the mating surface were obtained by using the fitting algorithm; finally, taking the contact stiffness of the mating surface as the objective and the surface machining accuracy as the constraint condition, the surface topography parameters are optimized. The results show that the average variance σ of the surface topography of the two different specimens after optimization increases by 0.98% and 2.71%, respectively, compared with that before optimization, which indicates the relative reduction in the difficulty and cost of surface processing. This study can provide an effective way to improve the optimization design of surface topography parameters and the performance of the whole machine.