Miracle-dz/UniFAR-FTUs huggingface dataset:
Application of response surface methodology for optimization of the stability of asphaltene particles in crude oil by TiO2/SiO2 nanofluids under static and dynamic conditions

ABSTRACT In this work, the onset of asphaltene flocculation for an Iranian crude oil by titration of samples with heptane in the presence and absence of the TiO2/SiO2 nanofluids was obtained by Near-IR spectroscopy. Nanoparticles and nanocomposites were characterized by BET, FESEM, EDX, XRD, and XRF analysis. Modeling and optimization of inhibition of asphaltene flocculation process by TiO2/SiO2 nanofluids were conducted by response surface methodology (RSM). Under optimum conditions (nanocomposite composition = 0.04 wt% (80%TiO2:20%SiO2), salinity = 4.01 wt%, and pH = 3.42), the onset point increased. For nanofluids stability analysis, the optimum nanofluid was compared with the two other nanofluids (SiO2 and TiO2) by visual observation method. The results indicated that high stability and surface area of the 80%TiO2 nanocomposites increase asphaltene adsorption on the particles surface that subsequently increases the onset point. In addition, the optimum nanofluid performance on the carbonate rocks was evaluated by contact angle and core flooding experiments. The 80% TiO2 nanofluid changed the wettability of carbonate rocks from strongly oil-wet to strongly water-wet condition and also decreased the residual oil saturation and enhanced the oil recovery with an increase in the recovery factor of about 15%. GRAPHICAL ABSTRACT
Urgent-SQ Implant: Safety and Efficacy, 18 Years After First Implantation.

Background: To evaluate the long term follow up in terms of safety and usability of the Urgent-SQ system (implantable tibial nerve stimulator) based on 1 year, 9 year follow up and novel results 18 years after first implantation in 2002.Materials & Methods: Since 2002, eight patients were implanted with the Urgent-SQ system. Seven patients were included in previous follow up studies, 1 patient had loss of efficacy before 1 year of follow up. During this study all patients who were included in the previous follow-up studies (n=7) were contacted to be interviewed regarding efficacy, usability and safety. Results: Five out of seven patients were available for assessment, mean age 72 years ± 8 (range 65-82). Two patients were considered lost to follow up. None of the interviewed patients reported safety issues, new adverse events or discomfort. One of the patients was able to visit the hospital for efficacy. However, treatment could not be performed due to deficiency of the external or internal component. All patients did not perform self-stimulation anymore due to external stimulator deficiency (n=2) or loss of effect (n=3). Conclusion: 18 year follow up of the Urgent-SQ implant demonstrates a high safety profile. However efficacy after 18 years is lacking in 60% whereas in 40% the therapy cannot be applied because the external stimulator is deficient. This most likely depicts the end of the lifecycle of the device.
O ensino remoto na percepção discente: desafios e benefícios

A pandemia do novo corona vírus modificou a atuação de diversos setores em todo o mundo, entre eles a educação, obrigando pessoas e instituições a remodelarem suas atividades, cumprindo o distanciamento social, como prevenção à disseminação do vírus. No setor educacional, foi implantado o ensino remoto emergencial, como possibilidade de continuação das atividades escolares. Nesse cenário, a pesquisa pretende compreender, na visão de discentes brasileiros, quais os méritos e deméritos do Ensino Remoto Emergencial (ERE) para o contexto educacional. A pesquisa é caracterizada como um estudo de caso qualitativo, que teve a participação de 144 discentes mediante questionário on-line, no qual foi notado insatisfação, relacionados não só ao acesso à internet e equipamentos, mas também, à modalidade de ensino imposta, afetando a qualidade do ensino e da aprendizagem. Entretanto, também são apontados benefícios, como flexibilidade de horários e diminuição de gastos. Assim, conclui-se que o ERE ainda precisa ser repensado, sendo baseado nas necessidades sociais, culturais, econômicas e psicológicas dos discentes, e não somente, em questões operacionais e teóricas. Ressaltamos que a pesquisa está vinculado ao projeto de pesquisa cadastrado na Plataforma Brasil sob o número 33812620.5. 0000.5528 e aprovado com o parecer 4.121. 645 de 29 de junho de 2020.
In vitro antibacterial activity of selected plant extracts against potato bacterial wilt (Ralstonia solanacearum Smith) in Rwanda

Bacterial wilt caused by Ralstonia solanacearum Smith is the most severe potato disease in Rwanda because there is no known pesticide for it and cultural control methods seem almost impossible to implement. Therefore, use of plant extracts with antibacterial activities which are locally available, economically affordable and environmental friendly could be an alternative in the management of the disease. This research focused on in vitro screening of the antibacterial activity of methanol, water and chloroform extracts of ten local plant materials against the pathogen. From this screening, methanol and water extracts of three promising plant species, i.e., tobacco, wild marigold and garlic were also used for determination of minimal inhibitory concentration (MIC). The results showed higher inhibition zone of methanol extracts (16.85 mm) against bacteria followed by water (14.42 mm) and chloroform (14.19 mm) extracts. All ten plant extracts inhibited the growth of the pathogen. Higher antibacterial activity was found in tobacco, wild marigold and garlic extracts (19.61, 18.56, and 18.3 mm inhibition zones, respectively). Minimal inhibitory concentration (MIC) of methanol extracts from tobacco and wild marigold was 6.25 mg mL-1 whereas, garlic methanol extract was 12.5 mg mL-1. Furthermore, MIC of water extract was 12.5 mg/mL-1 in all three plant species. The findings revealed that tobacco, garlic and wild marigold extracts are the best in the control of potato bacterial wilt. Moreover, methanol extracts are the most efficient in management of potato bacterial wilt in comparison to water and chloroform extracts.
New perspectives and designs into nature-inspired flexible electronics: status and applications

ABSTRACT Flexible electronics has received growing attention due to its intriguing properties in many fields, including health monitoring, human-machine interface etc. However, the narrow working range, disappointing detection limit and other problems have brought huge challenges to demanding practical applications of flexible electronics, thus seeking new perspectives to solve these problems. Nature is the first teacher of mankind. It has evolved for billions of years and developed countless admirable strategies to help organisms adapt to their surroundings. In this review, we rendered an overview of updated and rounded advances in nature-inspired flexible electronics. Firstly, we summarized the methods of combining biological materials with other materials to create flexible devices. Secondly, we unveiled a relationship between the biological structures and flexible electronics’ performance. Finally, we concluded the latest developments in mimicking biological functions. With span-new perspectives, these summaries and conclusions are expected to provide inspiration for designing nature-inspired flexible electronics.
Real interest rate convergence and monetary policy independence in CEE countries

In this paper we provide new empirical evidence relevant for discussions on monetary policy independence in the context of euro adoption in three Central and Eastern European (CEE) countries: Czechia, Hungary and Poland. Unlike many other authors, in this paper we focus on real and not nominal interest rates as real interest rates are at the hearth of modern macroeconomic and monetary policy theory. In the paper we employ several methodologies to test the convergence of real interest rates between these countries and the euro area and to determine the main drivers of real interest rates. Based on the unit root analysis we find evidence of convergence of real interest rates in these countries, thus confirming the real interest rate parity (RIRP) hypothesis. Next, using principle component analysis (PCA) we show that common factor extracted from the sample of CEE countries and individual euro area countries can explain high proportion of real interest rate developments in these countries. Finally, results of our newly proposed analytical framework for the analysis of determinants of real interest rates in small open economies, based on a Bayesian VAR model with block exogeneity, show that external shocks have non-negligible effect on real interest rate developments in selected CEE countries. Thus, our results indicate that real interest rates in CEE depend on factors that are beyond the scope of domestic monetary policy makers. In this sense we can conclude that (conventional) monetary policy independence in these countries is limited. Thus, we see the loss of monetary policy independence as overly emphasized argument in discussions on the euro adoption in these countries. However, we are aware that national central banks in CEE started to * Received: 02-03-2020; accepted: 11-11-2020 1 Senior Economic Researcher-Advisor, Croatian National Bank, Modelling Department. Scientific affiliation: applied macroeconometrics, economic policy, macroeconomics of small open economies. Phone: +38514590313. E-mail: mdeskar@hnb.hr. 2 Teaching and research assistant, University of Zagreb, Faculty of Economics and Business, Department of finance. Scientific affiliation: public finance, fiscal policy, taxation. Phone: +385 1 238 3170. E-mail: abuljan2@net.efzg. hr. 3 Chief Advisor, Croatian National Bank, Financial Stability Department, Scientific affiliation: macroprudential policy, financial stability, macroeconomics of small open economies. Phone: + 38514564879. E-mail: mirna.dumicic-jemric@hnb.hr. Milan Deskar-Škrbić, Antonija Buljan, Mirna Dumičić • Real interest rate convergence. 350 Zb. rad. Ekon. fak. Rij. • 2020 • vol. 38 • no. 2 • 349-380 rely more on non-conventional measures recently, which gives them a higher degree of flexibility (and autonomy).
Dryland Farmers on Climate Resilient Practices – An Adoption Study at an Industrialized Taluk of Tamil Nadu

Aims: To study the adoption of climate resilient practices by the farmers in the dryland region. Study Design: Cross-sectional survey design was used for the present descriptive study. Place and Duration of Study: The study was conducted in Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad (Prayagraj) during the year of 2018 and for the period of 6 months. Methodology: The study used direct interview method with the subjects using a structured and pre-tested interview schedule for primary data collection in the sampled area which is an industrialized taluk of Tamil Nadu. The selection of area was purposeful, whereas, selection of villages was random and 15 respondents form each village was convenient. The collected data was tabulated and interpreted using descriptive statistics and correlation analysis. Results: The results of the study suggest that there is a poor adoption level of climate resilient practices existing among the dryland farmers. While, some of the practices like incorporation of residues in to soil instead of burning, brown and green manuring, conservation tillage, temperature tolerant varieties, farm machinery custom hiring centre, location specific intercropping systems, crop rotation, usage of better planting materials, prophylaxis, custom hiring centre and weather based insurance were adopted to some extent. Though there was no specific intervention to sensitize on these practices, adoption of above mentioned practices were found which could be due to the passive adaptation by the farmers of the locality over years. And the results of correlation analysis revealed that there is a significant relationship between adoption of climate resilient practices and variables like the respondents’ education, exposure to mass media exposure, contacts with extension agents, innovativeness level, risk orientation and scientific orientation at 0.01% level of significance. Conclusion: The results of the study will definitely help in evaluating government projects (as baseline) like National Initiative on Climate Resilient Agriculture, and strengthening programme planning and implementation in climate change.
Ab initio theory of ferromagnetic transition metals and alloys under high pressure

The subject of the present thesis is the investigation of magnetic properties of transition metals and their alloys under high pressure by means of first-principles calculations. First, the results of the K-edge x-ray magnetic circular dichroism (XMCD) experiments on Ni and Co are interpreted. It is shown that the experimental pressure evolution of the data should be compared with that of the p-projected orbital magnetization. I emphasize that the spin and orbital moments have different behavior upon compression. In the case of FeCo alloy the structural transition occurs under the pressure of 35 GPa. I propose that the emergence of antiferromagnetism can explain the disappearance of the XMCD signal at the Fe and Co K-edges. Then, the phase transformation in FePd3 , induced under pressure of 12 GPa, is investigated. I demonstrate that the system is described by an extended Heisenberg model, containing strong biquadratic exchange interactions. According to the results, FePd3 undergoes a transition from the ferromagnetic to the noncollinear triple-Q state when compressed. Finally, the implementation of the stress tensor in the BigDFT software package is presented. It is shown that an explicit treatment of core electrons can considerably reduce the errors introduced by the pseudopotentials. Thus the estimates of the structural properties can be improved.
Adsorption Behavior on Cement Particles and Retarder Mechanism of Sodium Tripolyphosphate

In this paper,ζ-potential,adsorption amount of sodium tripolyphosphate(STPP),calcium ion concentration with different dosage of STPP has been discussed to analyse adsorption properties of STPP on surface of cement particles.Retarding mechanism of STPP has been discussed by the heat of hydration analysis,XRD,SEM.The result shows that STPP and calcium ions can easily formed complexes,which adsorb on surface of cement particles;when the content is 0.05%,adsorption rate can reach 97%;when the content is 0.4%,adsorption rate up to 89%;the present of complexes [CaP3O10]3-on surface of cement particles change the ζ-potential and inhibit the dissolution of calcium at the same time;it reduces the concentration of calcium ions in the liquid phase,and delay heat of hydration and formation of hydration products;when the dosage of STPP is more than 0.2%,there is little CH in hydration product of 1 d.
Optical Fiber Current Sensors Based on FBG and Magnetostrictive Composite Materials

Optical fiber current sensors are widely used in the online monitoring of a new generation power system because of their high electrical insulation, wide dynamic range, and strong anti-electromagnetic interference ability. Current sensors, based on fiber Bragg grating (FBG) and giant magnetostrictive material, have the advantages of high reliability of FBG and high magnetostrictive coefficient of giant magnetostrictive material, which can meet the monitoring requirements of digital power systems. However, giant magnetostrictive materials are expensive, fragile, and difficult to mold, so giant magnetostrictive composite materials have replaced giant magnetostrictive materials as the sensitive elements of sensors. High sensitivity, high precision, wide working range, low response time, and low-cost optical fiber current sensors based on magnetostrictive composites have become a research hotspot. In this paper, the working principle of the sensor, the structure of the sensor, and the improvement of magnetostrictive composite materials are mainly discussed. At the same time, this paper points out improvements for the sensor.
IDENTIFICAÇÃO DE DEPÓSITOS FLUVIAIS E DESCONECTIVIDADES ANTRÓPICAS NO BAIXO CURSO DO RIO UNA – PE

Houve a identificação dos tipos de depósitos fluviais existentes no baixo curso do rio Una, como também desconectividades antrópicas, uma vez que estas influenciam na configuração dos depósitos, bem como na dinâmica fluvial. Utilizou-se o primeiro estágio da proposta dos estilos fluviais (BRIERLEY e FRYIRS, 2005), relativa à categorização de confinamento de vale como fator primário da morfologia do canal, a partir disso, foi possível identificar trechos de canais onde são encontrados depósitos fluviais. Foram identificadas feições, através de imagens do PE3D e das atividades de campo, sendo realizado um mapeamento de detalhe destes depósitos. Por fim, foi localizada os principais elementos de desconectividades antrópicas presentes no baixo curso do rio Una, buscando associar como estes podem modificar a dinâmica natural do canal, obrigando-o a buscar novos níveis de base e ajustes.
Meaning and credibility of forward-looking disclosures: evidence from an entry game

Purpose- The study aims to find and analyze the equilibria for the forward-looking disclosures using game theory and to investigate the information signaling mechanism of such disclosures focusing on the credibility and meaning of them. Methodology- The study uses a cheap-talk game setting as a special form of signaling game in which forward-looking information are examined as costless, nonbinding and non-verifiable claims sent to a potential Entrant by the Incumbent firm. Findings- Equilibria are derived and neologism-proofness refinement is applied to rule out the implausible equilibria. Informative equilibrium exists only if the players’ preferences are more closely aligned. Entrant’s strategy is critical to determine which equilibrium is plausible. Under entry strategy, informative equilibrium is plausible and rules out the uncommunicative equilibria. However, under non-entry strategy, informative equilibrium fails to be plausible. Conclusion- Only under the entry strategy, the Incumbent should disclose its private information, whereas, under non-entry strategy, the Incumbent should not reveal its private information. Furthermore, the uncommunicative equilibria indicate that despite the Entrant’s pessimism about future, the Entrant prefers to choose entry strategy when the entry cost is sufficiently low. Contrarily, despite the Entrant’s optimism, non-entry becomes optimal when the entry cost is relatively high.
Rooftop Solar PV Penetration Impacts on Distribution Network and Further Growth Factors—A Comprehensive Review

In order to meet the electricity needs of domestic or commercial buildings, solar energy is more attractive than other renewable energy sources in terms of its simplicity of installation, less dependence on the field and its economy. It is possible to extract solar energy from photovoltaic (PV) including rooftop, ground-mounted, and building integrated PV systems. Interest in rooftop PV system applications has increased in recent years due to simple installation and not occupying an external area. However, the negative effects of increased PV penetration on the distribution system are troublesome. The power loss, reverse power flow (RPF), voltage fluctuations, voltage unbalance, are causing voltage quality problems in the power network. On the other hand, variations in system frequency, power factor, and harmonics are affecting the power quality. The excessive PV penetration also the root cause of voltage stability and has an adverse effect on protection system. The aim of this article is to extensively examines the impacts of rooftop PV on distribution network and evaluate possible solution methods in terms of the voltage quality, power quality, system protection and system stability. Moreover, it is to present a comparison of the advantages/disadvantages of the solution methods discussed, and an examination of the solution methods in which artificial intelligence, deep learning and machine learning based optimization and techniques are discussed with common methods.
Physical Exercise Goals of the Elderly through the Analysis of Kinetic and Kinematic Variables of Quick Walking—Results of the Koreans Elderly Using a Motion Analysis System

Since the global population is rapidly aging, social interest in the topic is increasing. However, there are not many studies on the elderly who are able to walk on their own, who make up the absolute majority of the total elderly population. Most studies and technological advancements are focused on either the development of assisting devices or on the elderly who use such devices or have a medical history. Therefore, this study analyzed the walks of 31 ordinary individuals of standard physical size and 31 elderly individuals. While there are studies on general gait and walk, there are not many on “maximum walking,” which is associated with a high risk of fall. For this purpose, a motion analysis system and the Ground Reaction Force Plate were used. The results of measuring and analyzing a total of 15 types of kinematic and kinetic variables as targets showed that the elderly experienced a reduced hike in the walking speed by approximately 5% during maximum walking when compared with normal walking. The variables related to balance were measured to be as high as 12%. Considering this, exercise of the elderly should be more focused on reinforcing variables related to balance, and in particular, emphasis should be placed on maintaining balance even when the walking speed increases.
Dependence of the electronic and crystal structure of a functionalized graphene on the concentration of chemically adsorbed fluorine

In this paper, we study the change in the ﬂuorine-functionalized graphene layers depending on the ﬂuorine concentration. Ab initio calculations were performed using the density functional theory method in the generalized gradient approximation. It was established that the metallic properties of the graphene layer become semiconducting after functionalization even at low concentrations of chemically adsorbed ﬂuorine ∼ 10 at. %. The band gap increases from 0.11 to 3.09 eV with an increase of the amount of adsorbed ﬂuorine.
Four-Quadrant Operations of Bidirectional Chargers for Electric Vehicles in Smart Car Parks: G2V, V2G, and V4G

This paper presents the four-quadrant operation modes of bidirectional chargers for electric vehicles (EVs) framed in smart car parks. A cascaded model predictive control (MPC) scheme for the bidirectional two-stage off-board chargers is proposed. The controller is constructed in two stages. The model predictive direct power control for the grid side is applied to track the active/reactive power references. The model predictive direct current control is proposed to achieve constant current charging/discharging for the EV load side. With this MPC strategy, EV chargers are able to transmit the active and reactive powers between the EV batteries and the power grid. Apart from exchanging the active power, the vehicle-for-grid (V4G) mode is proposed, where the chargers are used to deliver the reactive power to support the grid, simultaneously combined with grid-to-vehicle or vehicle-to-grid operation modes. In the V4G mode, the EV battery functions as the static var compensator. According to the simulation results, the system can operate effectively in the full control regions of the active and reactive power (PQ) plane under the aforementioned operation modes. Fast dynamic response and great steady-state system performances can be verified through various simulation and experimental results.