bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical safety limits for clinical stimulation investigated using depth and strip electrodes in the pig brain
Authors: Vatsyayan Ritwik , Cleary Daniel , Martin Joel R , Halgren Eric , Dayeh Shadi A 
Published: May 2021

Abstract

Objective. Diagnostic and therapeutic electrical stimulation are increasingly utilized with the rise of neuromodulation devices. However, systematic investigations that depict the practical clinical stimulation paradigms (bipolar, two-electrode configuration) to determine the safety limits are currently lacking. Further, safe charge densities that were classically determined from conical sharp electrodes are generalized for cylindrical (depth) and flat (surface grid) electrodes completely ignoring geometric factors that govern current spreading and trajectories in tissue. Approach. This work reports the first investigations comparing stimulation limits for clinically used electrodes in two mediums: in benchtop experiments in saline and in vivo in a single acute experiment in the pig brain. We experimentally determine the geometric factors, the water electrolysis windows, and the current safety limits from voltage transients, for the sEEG, depth and surface strip electrodes in both mediums. Using four-electrode and three-electrode configuration measurements and comprehensive circuit models that accurately depict our measurements, we delineate the various elements of the stimulation medium, including the tissue-electrode interface impedance spectra, the medium impedance and the bias-dependent change in the interface impedance as a function of stimulation parameters. Main results. The results of our systematics studies suggest that safe currents in clinical bipolar stimulation determined in vivo can be as much as 24 times smaller than those determined from benchtop experiments (for depth electrodes at a 1 ms pulse duration). Our detailed circuit modeling attributes this drastic difference in safe limits to the greatly dissimilar electrode/tissue and electrode/saline impedances. Significance. We established the electrochemical safety limits for commonly used clinical electrodes in vivo and revealed by detailied electrochemical modeling how they differ from benchtop evaluation. We argue that electrochemical limits and currents are unique for each electrode, should be measured in vivo according to the protocols established in this work, and should be accounted for while setting the stimulation parameters for clinical applications including for chronic applications.
Adjustable capillary imbibition enhancement in double-walled nanotubes with concentric tube length difference
Authors: Lu Yangchao , Wang Yangjie , Chen Jige 
Published: May 2021

Abstract
Capillary imbibition of water plays a significant role in various applications at both the macroscopic and microscopic scales. However, it is still unclear whether capillary imbibition could be manipulated by the geometry structure of the nanotubes. In this paper, we adjust the concentric tube length difference ∆L of the double-walled nanotubes (DWNTs) to manipulate the capillary imbibition by molecular dynamics simulations. Three configurations are considered, i.e. ∆L = 0 (the common DWNT structure, labeled as configuration I), ∆L < 0 (configuration II, the inner tube is shorter than the outer tube), and ∆L > 0 (configuration III, the inner tube is longer than the outer tube). By comparing with the single-walled nanotube, it is found that the imbibition velocities of the water molecules in the DWNT are weakened 9.1% in configuration I and enhanced 30%–46.5% in configuration II and 10% in configuration III. By analyzing the microscopic structure of the water molecules, it is found that the imbibition velocity adjustment originates from the potential energy difference of the water molecules in the water reservoir and at the entrance of the nanotube at the nanotube cylindrical pore. An exponential relation between the imbibition velocity v

L
and the potential energy difference ΔE is obtained as

v

L

(

t

)

∼

e

−

Δ
E

k

B

T

. Furthermore, it is found that imbibition velocity is independent from the radius differences in all three configurations. Our results suggest a possible way to manipulate the capillary imbibition behavior and it has significant implications for water treatment, nano-switches, catalysis engines and biological sensors.
Modified spectral method for optimal estimation in linear continuous-time stochastic systems
Authors: Rybakov K 
Published: May 2021

Abstract
The spectral method to solve estimation problems for linear continuous-time stochastic systems with polynomial measurements is presented. It is based on both the spectral form of mathematical description (the representation of deterministic functions and random processes by orthogonal series) and the particle filter. The main goal of this work is to implement the continuous-time particle filter without a time discretization. The proposed spectral method provides the possibility to solve estimation problems such as filtering, smoothing and prediction.
Combined system for indeterminate non-affine plant with control delay on the set of functioning states
Authors: Eremin E. L. , Nikifororva L. V. , Shelenok E. A. 
Published: May 2021

Abstract
In the present paper authors consider the synthesis of combined nonlinear control law for non-affine control plant with delay in the input variable with step-by-step changing of its dynamics. The control plant operates in conditions of a priori parametric and structural uncertainties in the presence of external noise and measurement of the controlled variable only. The structure of the control system includes the predictor-compensator and the filter-corrector.
Approximate methods of the solution of an optimal control problem on an operators network
Authors: Baturin V.A. , Sizykh V.N. 
Published: May 2021

Abstract
The mathematical models describing behaviour of an operators network, and in particular multi-stage processes, are quite common in practice. In this work, the authors propose approximate methods for solving the control problem with parameters on the network of operators. They are based on the methodology developed in works [1-4].
Technique for classifying the social network profiles according to the psychological scales based on machine learning methods
Authors: Branitskiy A. , Doynikova E. , Kotenko I. 
Published: May 2021

Abstract
A technique for classifying the social network users and groups by psychological scales of the Ammon’s test has been developed. To analyze user profiles, we have used several types of artificial neural networks (support vector machine, linear regression, multilayer neural network and convolutional neural network), and for group analysis, we applied text classifiers (bag of words, weighted bag of words, continuous bag of words, skip-gram and fastText classifier). The scope of the technique is identifying deviations in the psychological state of users of social networks and monitoring these changes considering users’ groups to detect destructive influences. An experiment was carried out, as a result of which it was found that a multilayer neural network with an activation function of the ReLU type has the best accuracy.
Optimization of the interplanetary flight to Mars with three-pulse approach to Phobos based on Lagrange principle
Authors: Samokhin A.S. , Samokhina M.A. 
Published: May 2021

Abstract
The problem of optimal control of the spacecraft interplanetary flight from the Earth to Mars with a three-pulse approach to the Phobos tracking orbit is considered. The departure of the spacecraft from the Earth is also approximated by pulses. The attraction of the Earth and Mars is taken into account. The problem is solved numerically on the basis of Lagrange principle. The results are compared with the scheme of a full turn free approach to Phobos. The initial approximation is carried out based on a combination of Lambert problems solutions. The software package is developed. Ephemerides are taken into account in the calculations, and the NASA SPICE package is used.
Intelligent system for data analysis and decision-making on test results
Authors: Saitova G.A. , Elizarova A.V. 
Published: May 2021

Abstract
Intelligent data analysis systems are designed to minimize the efforts of a decision-maker in the process of data analysis. The article deals with the tasks of intelligent processing and analysis of data from an electronic engine control system unit during testing. An intelligent data analysis system is proposed with the subsequent decision-making on the states of the engine and the electronic control system during test flights. With the help of artificial intelligence methods, causal relationships and regularities of the parameters of a turbojet engine have been revealed.
Results of computer simulation of force impact of difficult marine conditions on underwater objects
Authors: Guryev Y. V. , Slutskaya M. Z. 
Published: May 2021

Abstract
The paper presents a numerical method for calculating the hydrostatic and hydrodynamic reactions of marine underwater objects moving in an arbitrary manner under conditions of internal waves and sea currents. The method is based on the theory of potential, eddy and wave currents. The effect of viscosity on hydrodynamic reactions is taken into account indirectly by introducing a special eddying system that simulates the effect of longitudinal vortices on the hull on the pressure distribution. The paper presents the results of a computational experiment are presented, which made it possible to identify both new and confirm previously obtained regularities of the influence of the object’s parameters and hydrophysical conditions on the desired reactions. The developed mathematical and software tool can be recommended for use in the design of underwater objects and the creation of simulators for their dynamics.
Universal pause of the human-perceived winter warming in the 21st century over China
Authors: Ding Ting , Gao Hui , Li Xiang 
Published: May 2021

AbstractLow-temperature weather accompanied by strong chill wind is considered as a great risk factor for human health in winter, especially in some extreme weather conditions. Based on the observation data and the NCEP/NCAR reanalysis data of air temperature and wind velocity in 1961–2019, the warming pause of wind chill temperature (WCT) in the 21st century in China is first revealed in this paper. A significant increasing trend of WCT is found during 1961–1999 (P1), and a slight decreasing trend in 1999–2019 (P2) is detected by a 21 year running trend analysis. The extreme cold WCT day (WCD) with the WCT index below the 10th percentile also shows a decreasing trend in P1 but a slight increasing trend in P2. Both the WCT and the extreme WCD consistently display the warming pause in seven climatic regions in China. That means the slowdown or even decrease of human bioclimatic temperature in recent two decades may lead to an increasing risk of frostbite and other cold-related diseases in the country. Both the decreasing trend of mean temperature and the increasing trend of the wind speed contribute to the slowdown of the human-perceived warming in the 21st century, and this conjoint contribution could be linked to the East Asian winter monsoon circulations over Siberia, i.e. the Siberian high. The variation of averaged sea level pressure over the central region of the Siberian high shows high consistency with both the WCT and the extreme WCD in the whole study period, by a decreasing rate of −1.28 hPa per decade in P1 and an increasing rate of 1.26 hPa per decade in P2.
Smart Trowel Tool for Smooth Plastering Work
Authors: Doraisamy S V 
Published: May 2021

Abstract
Plastering is the most important activity in construction works. It is done widely as a finishing technology for interior and exterior walls made of bricks, concrete or timber, as it provides heat insulation, sound absorption and protection against air pollution and weather, thus providing a clean, level surface for further finishing tasks. Plastering work usually consumes time and involves a lot of cement wastage. A trowel is used as a tool in plastering work but yet time consumption is high in completing the work. It is because the design of the trowels and the quality of the trowel itself is not suitable for plasterers. This study focuses on designing a smart trowel tool for smooth plastering work for low-cost residential building, and to compare the time consumption for the smart trowel tool with the conventional method. The smart trowel tool was tested with 4 experts from the construction industry at the end. The main aspect that was taken into consideration in determining the most suitable materials to build this tool was the time factor in conducting and completing the plastering works. The feedbacks given through expert validation was positive and suggested that such a tool should be marketed in the related field. This is mainly because the smart trowel tool that was build tends to give comfortability and convenience to its’ users. The tool further plays the role of as environmentally friendly that contributes towards sustainability. Lastly, the smart trowel tool consumes lesser time compared to the conventional method.
Physical and mechanical properties of cement board made from oil palm empty fruit bunch fibre: A review
Authors: Maynet W , Samsudin E M , Soh N M Z Nik 
Published: May 2021

AbstractOil palm empty fruit bunch (OPEFB) fibre has been introduced to replace current materials mainly such as wood fibre that was not encouraged to be used as a construction sourced due to the sustainability of wood fibres and prevents the high demand of forest resources. In Malaysia, the cultivation and use of the oil palm and its products have increased because of high market demand, and this has resulted in the abundant availability of the empty fruit bunch (EFB). The EFB fibre geometry and particle size in the EFB cement bonded boards have their own mechanical and physical properties. The fibre to cement ratios are also different to boards made out of wood fibres. This experimental research work has been conducted by other researchers. The larger the particle size, the better the compaction of EFB-CB effects of cement setting by much larger surface on the board area. Short particles lead to low values of modulus of elasticity (MOE), caused by inadequate of empty fruit bunch (EFB) particles to cement substances. Nevertheless, short particles avoid large void spaces and irregularities towards cement board. Using different Cement-EFB fibre ratio has direct influence on thickness swelling (TS), modulus of rupture (MOR), and modulus of elasticity (MOE). Strength of EFB-CB depends on the bonding between fibre and cement composites. The pre-treatment fibre was indicated where the EFB fibre composite were dimensionally stable for bonding mechanisms and could be used for both interior and exterior building utilizations based on the tested physical and mechanical properties on cement-boards.
Structural behaviour of PSCC slab panel under four-point bending test
Authors: Iman M A , Mohamad N , Samad A A A , George Steafenie , Tambichik M A , Bosro M Z M 
Published: May 2021

Abstract
Precast Self-Compacting Concrete (PSCC) is one of many types of approach in Industrialised Building System (IBS) that were used to speed up construction to meet consumer’s demand. The usage of Self-Compacting Concrete (SCC) will profit in many ways such as faster construction, reduction in manpower, easier placing, uniform and complete consolidation, better surface finishes, improved durability, increased strength, and safer working environment. The addition coir fibre in PSCC can improve the tensile strength and flexural strength in the concrete mixture.by combining the two elements of SCC and CF in PSCC slab panel, the desired structural behaviour can be achieved. The four-point bending test was conducted on the all 4 type of PSCC slab panel that is solid control, solid CF, hollow control, and hollow CF. The solid PSCC-CF slab panel has the best structural performance compared to the other 3 other PSCC slab panel. The crack and ultimate load of the solid PSCC-CF slab panel recorded are 24.5 kN and 35 kN respectively compared to the reading collected from the other 3 slab panels. The crack propagation on the solid PSCC-CF slab panel also less propagated due to the addiction of CF that build concrete bridges. The load-deflection profile of solid PSCC-CF slab panel also shown the best result compared to the other slab panel. The load-strain profile recorded also shown the highest values of 105 micro strain on top and 53.14 micro strain on side of solid PSCC-CF slab panel.
Strength Performance of Oil Palm Shell Lightweight Aggregate Concrete
Authors: Jamellodin Zalipah , Sim Lam Phooi , Qing Huang Chai , Adnan Suraya Hani , Salleh Norhafizah , Hamid Noor Azlina Abdul 
Published: May 2021

Abstract
The concrete consumption that is high in the construction industry had resulted in uncontrolled aggregates exploitation. The extraction of these natural resources has raised great environment concerns that the use of waste materials as replacement of aggregates is proposed. Oil palm shell lightweight aggregate concrete (OPS LWAC) is produced by full replacement of oil palm shell (OPS) to coarse aggregate. OPS is the lightweight aggregates that potentially produce lightweight aggregate concrete (LWAC). Palm oil fuel ash (POFA) is also the byproduct of the palm oil industry that can be utilized to partially replace the fine aggregates. The objective of this study is to investigate the effect of POFA as partial fine aggregates replacement on density, compressive and tensile strength of OPS LWAC and to determine the optimum replacement percentage of fine aggregates with POFA. The control mixes were prepared with 100% OPC in the concrete while modified mixes contained various percentages of POFA, which were 5%, 10%, 15% and 20% as the replacement of fine aggregate. The specimens of cubes sizes 100 mm x 100 mm x 100 mm and cylindrical specimens with diameter of 100 mm and height of 200 mm were prepared and tested. The concrete mixtures were mixed according to the Department of Environment (DoE) method followed by the trial mixed. Mixes with 10% replacement of POFA to fine aggregate obtained the highest compressive strength and tensile splitting tensile strength which were 26.3 MPa and 2.37 MPa respectively. The property of POFA plays a role in the concrete strength determination. The higher replacement percentages resulted in lower density of OPS LWAC.
Utilization of Fruit Wastes (Jackfruit and Mango Seeds and Banana Trunk) as Natural Coagulants in Treating Municipal Wastewater
Authors: Shahimi Nur Shahzaiwa Wafa , Zaidi Nur Syamimi , Bahrodin Muhammad Burhanuddin , Amran Amir Hariz 
Published: May 2021

Abstract
The adequacy of chemical coagulant such as alum is all around perceived. However, there are numerous drawbacks including impeding impacts on human well-being and generation of high sludge volumes. Therefore, this study was conducted to investigate potential of fruit wastes - jackfruit (artocarpus heterophyllus) seeds, banana trunk peduncles (musa) and mango (mangifera indica) seeds in becoming natural coagulant to treat wastewater. A series of jar test was performed to determine the effect of individual coagulants on turbidity removal, coagulation activity and COD removal under various operating factors such as type and concentration of solvents used for extraction, pH and coagulant dosage. From the findings, optimum solvent concentration of 2.5M of sodium hydroxide (NaOH) reacted with banana trunk peduncles at optimum pH and dosage of pH 7 and 50 mg/L, respectively with turbidity removal of 90.2%, coagulation activity of 83.4% and chemical oxygen demand (COD) removal of 94.8%.
Physical Simulation for Effect Seasons and Fertilizer on Solidified Fabric Peat Soil; A Soil Column Model Study
Authors: Tajuddin S A M , Rahman J A , Mohamed R M S R , Al-Gheethi A 
Published: May 2021

Abstract
Soil stabilization is a method to improve the weakness of fabric peat soil structure which is a result of larger particle size pore. Therefore, the fabric peat soil is solidified using mixture of cement, fly ash and bottom. The present study aimed to investigate a physical simulation of soil column model as a response for affecting the wet and dry seasons and fertilizer on the solidified fabric peat soil. The column mode was investigated by analysis the water leaching micronutrient using atomic adsorption spectroscopy (AAS). The results revealed that the nitrate has the highest concentration (35.55 mg/L) on Run 3 (Fibric, rainwater, solidified peat and fertilizer) at upper area in the dry season. In comparison, potassium (K) recorded the lowest concentrations (1.14 mg / L) on Run 2 (fibric, rainwater and fertilizer) at upper area in the wet season. The highest (22.92 mg/L) and lowest (0.10 mg/L) calcium was recorded on Run 3 and Run 2 with both at upper area in wet season. These findings indicated that the chemical binder used as stabilization soil influenced the nutrient quality especially calcium which is one of the major compound materials in cement.
A Column Study on The Efficiency and Reusability of Kapok Fibre as Car Wash Wastewater Treatment
Authors: Hashim N H , Chen W C , Ibrahim M S S , Abdullah N M , Abdullah Z 
Published: May 2021

Abstract
The car washing industry which consumes large amount of water produces Car Wash Wastewater (CWW) which were likely to exceeds the standard set in both Malaysia’s and Singapore’s regulation. Kapok Fibre (KF) is a natural adsorbing material which have large lumen and low density is believed to be able to act as an adsorbent to manage the CWW. This study was done to determine the characteristic of KF and CWW and investigate the efficiency of KF in treating CWW along with the reusability of KF through a column study with Organic Loading Rate (OLR) of 12.41g COD/L.day. The CWW contains a certain concentration of Chemical Oxygen Demand (COD, Oil and Grease (O&G), and Anionic Surfactant (AS) though the interaction between KF and AS is novel. KF found out to has the capability in removing COD, O&G, and AS up to 88.37%, 100%, and 83.8% respectively. However, in reusability experiment there is limitation to KF in which by exceeding the operation time to 600 minutes of treatment, the efficiency in removing COD, O&G, and AS were found to drop to 62.02%, 75%, and 55% respectively. This shows that KF could be an avant-garde, low-cost sustainable treatment to treat CWW instead of the conventional high cost and complex operating system.