bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inversion formulas and their finite-dimensional analogs for multidimensional Volterra equations of the first kind
Authors: Solodusha Svetlana , Antipina Ekaterina 
Published: January 2021

Abstract
The paper focuses on solving one class of Volterra equations of the first kind, which is characterized by the variability of all integration limits. These equations were introduced in connection with the problem of identifying nonsymmetric kernels for constructing integral models of nonlinear dynamical systems of the “input-output” type in the form of Volterra polynomials. The case when the input perturbation of the system is a vector function of time is considered. To solve the identification problem, previously introduced test signals of duration h (mesh step) are used in the form of linear combinations of Heaviside functions with deviating arguments. The paper demonstrates a method for obtaining the desired solution, developing a method of steps for a one-dimensional case. The matching conditions providing the desired smoothness of the solution are established. The mesh analogs of the studied integral equations based on the formulas of middle rectangles are considered.
Generation of a random anisotropic incompressible turbulent velocity field in accordance with the calculated flow statistics
Authors: Alexandrov A V , Dorodnicyn L W , Duben A P , Kolyukhin D R 
Published: January 2021

Abstract
On the base of Randomized Spectral Method (RSM), a new stochastic algorithm for the generation of homogeneous anisotropic turbulent velocity fields has been developed. This technique provides incompressibility of the obtained velocity field realizations simultaneously with the two main required statistical properties—the Reynolds-stress tensor and the turbulent energy spectrum. The method is computationally efficient and can easily be extended to the case of inhomogeneous turbulence.
About the effect of rounding on the properties of tests for testing statistical hypotheses
Authors: Yu Lemeshko B , Lemeshko S B 
Published: January 2021

AbstractThe paper shows the results of the influence of rounding errors on the distribution of statistics for testing various statistical hypotheses. It is shown that when rounding errors are commensurable with the standard deviation, measurement errors in the distribution of statistical tests (goodness-of-fit tests, homogeneity tests, normality tests, etc.) can significantly deviate from those that occur in the absence of rounding. Recommendations are given for applying the tests in such situations.
Flow simulation around circular cylinder at low Reynolds numbers using vortex particle method
Authors: Kuzmina K , Marchevsky I 
Published: January 2021

Abstract
The algorithm of the Viscous Vortex Domain method implemented in the author’s code VM2D is investigated. This code allows simulating 2D viscous incompressible flows and solving fluid-structure interaction problems. The verification of the algorithm, namely, the correctness of taking into account the viscosity effect, is performed on well-studied test problems of the flow simulation around a circular cylinder for Reynolds numbers in the range 20 . . . 200: the problem of the impulse start of the circular cylinder is considered, and the dependency of the flow separation angle on the Reynolds number is investigated. The comparison shows that for low Reynolds numbers (up to 140), the flow separation angle obtained in numerical simulations by using the VM2D code is in good agreement with the results of other studies. For higher Reynolds numbers, the estimated separation angle is slightly overestimated.
New decomposition method for the solutions of linear Schrödinger equation
Authors: Edeki S. O. , Onyemekara K. C. 
Published: January 2021

AbstractThe Schrödinger equation serves as the fundamental equation for quantum mechanics. In this article, we consider the theoretical and numerical solutions of Schrödinger’s linear equations. This is achieved using the new semi-analytical approach as an alternative to the classical Adomian Decomposition Method (ADM). The new method is referred to as Telescoping Decomposition Method. Some cases are considered; the results obtained display high level of convergence to their exact forms. The improved version is very useful and reliable; it requires less analytical effort, even without giving up precision. Thus, it is also highly recommended for the solution of related linear and nonlinear differential models in the fields of applied research.
Existence results for a resonant third-order problem with two dimensional kernel on the half-line
Authors: Imaga O. F. , Iyase S. A. , Bishop S. A. 
Published: January 2021

Abstract
The purpose of this research is to establish conditions that guarantee the solvability of a resonant third-order boundary value problem (BVP) on the half-line. The resonant problem is subject to integral and m-point boundary conditions while, the kernel of the differential operator is equal to two. The coincidence degree theory will be applied and an illustrative example will be considered to demonstrate the result.
The convergence properties of a new hybrid conjugate gradient parameter for unconstrained optimization models
Authors: Sulaiman I M , Mamat M , Waziri M Y , Yakubu U A , Malik M 
Published: January 2021

AbstractThe hybrid conjugate gradient (CG) algorithms are among the efficient modifications of the conjugate gradient methods. Some interesting features of the hybrid modifications include inherenting the nice convergence properties and efficient numerical performance of the existing CG methods. In this paper, we proposed a new hybrid CG algorithm that inherits the features of the Rivaie et al. (RMIL*) and Dai (RMIL+) conjugate gradient methods. The proposed algorithm generates a descent direction under the strong Wolfe line search conditions. Preliminary results on some benchmark problems reveal that the proposed method efficient and promising.
A robust energy policy review of selected African countries: An impetus for energy sustainability in Nigeria
Authors: Soyemi A O , Samuel I A , Adesanya A , Akinmeji A , Adenugba F 
Published: January 2021

Abstract
Power rationing has become the bane of the Nigerian power sector, plunging the nation into prolonged periods of darkness and costing about 2.5 percent of her GDP annually. Although, installed generating capacity is almost 13 GW, the situation worsened by an overdependence on thermal and hydro generation, high losses, and a poor tariff structure. In the face of these challenges, Nigeria seeks to achieve universal access by 2030 with sustainable power having a share of 30 per cent in her energy mix. Despite the existence of frameworks supporting this target, Nigeria’s policies are still weak; indicated by her low Regulatory Indicator for Sustainable Energy (RISE) score of 30. To reach universal access by 2030 and fulfil SDG 7; Nigeria needs the right mix of policies. This study aims to review, draw lessons from the successful and unsuccessful implementation of similar policies in five countries and give recommendations.
Design and implementation of a single phase to three phase rotary converter
Authors: Olowoleni J. O. , Awosope C. O. A. , Adoghe A. U. , Oguntosin V. , Okupevi E. S 
Published: January 2021

Abstract
Epileptic power supply, scarcity of fuel, and the ever increasing demand for power supply have given rise to the development of several off-grid and on-grid power alternatives. A single phase to three phase rotary phase converter is a machine that can generate three phase power supply from an existing single phase source. This is a cheap means of generating three phase power especially in some residential environments where access to three phase power is limited. Some home equipment such as air conditioners and refrigerators run on three phase power also workshop owners and technicians have need to operate three phase machinery which may include table saw, drilling machine, lathe machine, and any machinery that runs on three phase power.
Effect of distributed generation placement on power system: A case study of Eko electricity distribution company, LAGOS
Authors: Bango Owolabi P. , Agbetuyi A. F. , Samuel I. A. , Abdulkareem A. , Adoghe A. U 
Published: January 2021

Abstract
Protection coordination of distribution network has been one of the issues with the distributed generators integration. The reason is that the distribution network is radial in nature by which energy flow is unidirectional. The research aim is to investigate how the location or placement of DG affects the protection setting of the existing network. The healthiness of the test distribution system used in this work is investigated with and without DG connection by use of load flow analysis using Neplan software. The results confirm that the location or placement of DG with the distribution system connection improves the voltage profiles at each bus and active power load loss. The DG placed 1km away from point of common coupling (PCC), the voltage profiles is 10.448Kv with DG connection, and 10.442kV without DG connection, while active power load loss is 69kW with DG connection and 71kW without DG connection. Also, DG placed 6km away from point of common coupling the voltage profiles is 10. 404kV with DG connection 10.372Kv without DG connection, while the active power load loss is 110kW with DG connection and 131kW without DG is connected. Moreover, with the DG placed 1km away from the point of common coupling (PCC) the fault current 17.596kA with DG connection and 3.286kA without DG connection, while 6km away from the PCC is 17.543kA with DG connection and 3.286kA without DG connection. It can be concluded that as the distance of the DG from the PCC increases, the fault current also increases which affects the protection scheme of the existing distribution system.
Growth and characterization of copper cadmium sulphide thin films
Authors: Emegha J. O. , Damisa J. , Elete D. E. , Arijaje T. E. , Akinpelu A. , Ogundile P. O. , Onumejor C. A 
Published: January 2021

Abstract
Copper cadmium sulphide thin film was deposited onto glass (soda-lime) substrates using chemical bath deposition (CBD) technique at room temperature. Chemical, optical, structural, and microstructural features were examined via the Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), UV-Vis Spectroscopy, and High-resolution Transmission Electron Microscopy (HRTEM). FTIR revealed that the associated chemical bond was below the 900 cm-1 marks. The optical band-gap of 2.36 eV was estimated from the absorption analysis. X-ray diffraction measurements reveal that the deposited material is polycrystalline with hexagonal and cubic structures typical of the binary constituents of and thin films. The grain sizes were randomly distributed and ranged between 35 and 60 nm as indicated by the HRTEM.
Real Option Technique for an Assessment of the Itakpe Iron Ore Project
Authors: Amusan Adeola R. , Adinya Ini 
Published: January 2021

Abstract
This study examines the viability of an iron mining mineral with the approach of real options, which allows the mining project flexibility and scalability. A positive value for the Option to delay was achieved, which indicates the feasibility of the Itakpe project. In addition, the Option to abandon before the expiration of the project under unfavorable market conditions was obtained.
Solution of a barrier option Black-Scholes model based on projected differential transformation method
Authors: Edeki S. O. , Fadugba S. E. 
Published: January 2021

Abstract
In this article, the solution of the linear variant of a Barrier Option Black-Scholes Model (BOBSM) is considered via a semi-analytical approach referred to as the Projected Differential Transformation Method (PDTM). Similar to the traditional Differential Transformation Method, this new approach demonstrates feasible progress and efficiency of operation. For simplicity of illustrative, the BOBSM is converted to an equivalent heat-like form, and a series-form of the solution (root) is successfully obtained. Hence the PDTM is suggested for both pure and functional sciences for strongly nonlinear differential models with financial applications.
The influence of coffee cherry fermentation on the properties of Cascara arabica from Subang, West Java
Authors: Sholichah E , Desnilasari D , Subekti R J , Karim M A , Purwono B 
Published: January 2021

Abstract
Cascara is an infusion beverage of dried coffee cherry pulp prepared from a by-product of coffee production. Cherry of arabica coffee was fermented with spontaneous fermentation, Lactobacillus plantarum and yeast (Saccharomyces cerevisiae) at room temperature for 24 hrs. The properties of cascara including total phenolic, flavonoid, and caffeine contents, antioxidant activity, colour, and sensory acceptance were evaluated. Results showed that cascara from L. plantarum fermentation (Y) exhibited the highest polyphenols and caffeine contents of 46.78 ppm and 52.8 ppm, respectively. Cascara from spontaneous fermentation (X) resulted the highest flavonoids content and antioxidant activity of 0.28 ppm and 89.52%, respectively. The result of sensory evaluation showed that cascara from yeast fermented cherry obtained the highest overall acceptance score of 4 out of 6.
Pumpkin flour effects on antioxidant activity, texture, and sensory attributes of flat tubers noodle
Authors: Novita Indrianti N , Sholichah E , Afifah N 
Published: January 2021

AbstractCanna and arrowroot are local tubers which have high amount of amylose content and suitable for noodle. Flat noodles are one type of noodles that are characterized with a thin flat shape and is generally made from starch. Pumpkin flour is one of the processed products of pumpkin fruit, which can be used in manufacturing of formulated foods as functional ingredient. The aim of this research was to study the effect of pumpkin flour on texture, antioxidant activity, and sensory attributes of flat tubers noodle. In this study, flat noodle was made from canna or arrowroot starch, which is added with pumpkin flour. We added the pumpkin flour (0%, 5%, 10%, and 15% w/w, canna or arrowroot starch basis) in the flat noodle formulation. Result showed that the addition of pumpkin flour increased antioxidant activity of flat tubers noodle. The stickiness of flat tubers noodle increased with the increasing of pumpkin flour level. Flat noodle made form arrowroot starch was stickier than flat canna noodle. Sensory analysis was carried out on flat canna noodle with hedonic scoring method to identify which product is the most preferred by the panelist. Generally the aroma and taste of flat canna noodle did not vary with increasing of pumpkin flours level. Flat noodle made from canna starch with 10% of pumpkin flour obtained the highest score for color, texture (stickiness), and overall acceptability assessed. Antioxidant activity and stickiness measurement of flat canna noodle with 10% of pumpkin flour were 39.80% and 3350 gf respectively.
Using kefir glucomannan to modify the diversity and composition of cecum bacterial in Sprague Dawley rats with metabolic syndrome
Authors: Desnilasari D , Harmayani E , Widada J , Nurliyani  
Published: January 2021

Abstract
This study aimed to determine the effect of kefir and kefir glucomannan (Kefir-GM) to the diversity and composition cecum bacteria and bodyweight and feed intake in rat metabolic syndrome. Research carried out used four group’s treatment, namely (1) control, normal rat (2) rats with metabolic syndrome (3) diet kefir in rats with metabolic syndrome, and (4) diet kefir-GM in rats with metabolic syndrome. After 4 weeks, cecum was taken for analysis of the diversity and composition of bacterial. Kefir and Kefir-GM in rats metabolic syndrome did not significantly affect the diversity at p<0.05, but increased Lactobacillus 14.61% and Bifidobacterium 2.2%, and decreased Clostridium 38.15% and Bacteroides 22.51%. Bodyweight and feed intake did not significantly different at p<0.05. Based on this research, kefir and Kefir-GM did not affect diversity but it is able to modify composition bacteria on cecum and also can keep the bodyweight and feed intake in rats.
Bio-modified soybean meal as a new protein source for food
Authors: Istiqomah L , Damayanti E , Suryani A E , Susilawati I O , Lutfiani  
Published: January 2021

Abstract
Soybean meal has long been considered as a plant protein source particularly for animal feedstuff. Nowadays, there is a promising prospect of this material for food processing. However, its protein utilization has drawbacks, such as poor protein solubility and anti-nutritional factors called phytic acid. The phytic acid could be reduced by the addition of phytase, whereas nutrient content enhanced by microbial fermentation. In this study, we analyzed the bio-modified of soybean meal (SBM) through fermentation by phytase producing Lactobacillus plantarum A1-E to evaluate its effect on nutritional quality and anti-nutrient factor called phytic acid and aflatoxin. The study was designated into two treatments consisted of unfermented soybean meal (USBM) and fermented soybean meal (FSBM) by L. plantarum A1-E. Parameters observed were microbial population, phytic acid content, aflatoxin content, and nutrient composition (moisture, ash, crude protein, crude fiber, and lipid). Data were analyzed using analysis of variance (ANOVA) and a T-test to compare treatment means. FSBM by L. plantarum A1-E increased population (6.8x107 CFU/ml) during 72 h incubation (P<0.05) than 0 h (2.1x106 CFU/ml). FSBM reduced phytic acid content (34.13%) and aflatoxin (6.12%) compared to control (USBM). Fermentation during 72 h had on average more crude protein (1.33-fold), crude fiber (2.09-fold), ash (1.13-fold), and less crude lipid (0.71-fold) than SBM. Thus, it can be concluded that FSBM by phytase producing L. plantarum A1-E could be applied for degradation phytic acid during food processing and represents an improvement in nutritional quality thereby becomes potential raw material as a new protein source for food.
Wastewater treatment based on remazol blue using DBD plasma reactor under acidic and basic conditions
Authors: Khairunizzahrah Badzlina , Bismo Setijo 
Published: January 2021

Abstract
Synthetic dyes are one of the most dangerous components of textile wastewater. Waste that contains various organic compounds, especially synthetic dyes, causes a high Chemical Oxygen Demand (COD) values. Remazol blue is a reactive dye that is widely used for the textile dyeing process. Therefore, water pollution occurs when the dye waste produced from textile activities is discharged into water bodies without prior treatment. In this study, innovation in waste treatment technology was applied in the Dielectric Barrier Discharge (DBD) plasma reactor. DBD are non-thermal plasma reactors designed to degrade organic and inorganic compounds in wastewater through oxidation process. This is carried out by active species, such as ozone (O3), hydrogen peroxide (H2O2) and hydroxyl radical (•OH), which are formed in the reactor. The study aims to evaluate the performance of non-thermal DBD plasma reactor in treating wastewater containing one of the textile dyes, namely remazol blue. The results showed that the percentage of degradation achieved was 98.43% within a process time of 120 minutes with a final concentration of 0.75mg/L. Furthermore, it showed that optimum conditions were obtained at pH value of 4, air flow rate of 2.5L/min, liquid flow rate of 50mL/min and a primary Neon sign transformer (NST) voltage of 19kV.
Antioxidant activity of butanolic extract from Madang Gatal (Schima wallichii Choisy) Leaves
Authors: Widiyarti Galuh , Widodo Ginanjar , Sampora Yulianti , Lotulung Puspa Dewi , Hanafi Muhammad 
Published: January 2021

Abstract
Antioxidant activity of the butanolic extract from Madang Gatal (Schima wallichii Choisy) leaves was studied in the research. Antioxidant activity was analyzed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical oxidation method. Furthermore, the extract was purified using column chromatography to yield 4 partially purified fractions (B1-B4). The extract and B2 fraction possess strong antioxidant action with IC50 value 12.55 and 24.50 μg/ml, respectively. The B1 and B3 fractions have moderate antioxidant activity with IC50 value 70.55 and 90.26 μg/ml, while B4 was not active as antioxidant with IC50 value of 228.28. The target compound of the fraction most active as an antioxidant (B2) was separated by preparative Thin Layer Chromatography (TLC). The isolate was then identified using Fourier Transform Infra-Red (FTIR) and Liquid Chromatography Mass Spectroscopy (LCMS). The IR spectra displayed that the bioactive compound of B2 was predicted as flavonoid with MS 290.25 g/mol. The major compound contained in a putative compound known as catechin with an IC50 value was 17.97 μg/ml.
Synthesis layered material of MnO2and TiO2as the support of molybdenum catalyst for bio-crude oil upgrading process
Authors: Rinaldi N , Dwiatmoko A A , Kristiani A 
Published: January 2021

AbstractLayered materials are attractive for many applications because of their unique structure consisting of stacked sheets that can be controlled and modified. In this work, various synthetic layered materials (SLMs)i.e., Na-MnO2, H-MnO2, and Cs-TiO2have been successfully prepared as the support for molybdenum (Mo)-based catalyst and applied for bio-crude oil hydrodeoxygenation (HDO) process. A commercial Mo/Al2O3catalysts will also be utilized as a benchmark. The physical and chemical properties of the catalysts were characterized by using an X-ray diffractometer, X-ray fluorescence, surface area analyzer, NH3-temperature-programmed desorption, and scanning electron microscopy. The characterization results showed that the interlayer ion exchange of Na+ions with H+ions was successful for MnO2support. The impregnation of the MoO3into SLMs increased the surface area, pore-volume, average pore size, and total acidity. The HDO of bio-crude oil using MoO3/Na-MnO2catalyst produced a higher HHV value of 38.75 MJ/Kg and a DOD value of 82.75% compared to other prepared catalysts or even the MoO3commercial catalyst.
Effect of Ag and Mn doping for methylene blue photodegradation performance
Authors: Jessica  , Ibadurrohman M , Slamet  
Published: January 2021

Abstract
Currently, wastewater management is ineffective, operationally expensive, and difficult to be implemented in Indonesia. The photocatalyst is a technology that may answer this problem. Titania (TiO2) is a high-activity, inexpensive, stable, and non-toxic photocatalyst material. However, TiO2 has large band-gap energy and rapid recombination. In this research, TiO2 was doped by Ag (a noble metal) and Mn (a transition metal) to compare the performance of photocatalysts in organic pollutant degradation, using methylene blue. Ag/TiO2 catalyst was synthesized by Photo Assisted Deposition (PAD) method, while Mn/TiO2 was synthesized by impregnation method. The physicochemical properties of both catalysts were assessed by SEM-EDX and UV-Vis DRS. SEM-EDX indicated that both methods successfully doped Ag and Mn into TiO2. Besides, UV-Vis DRS confirmed the presence of metal dopants that caused the narrowing of the bandgap. Ag/TiO2 catalyst increased the degradation of methylene blue by up to 97% in 30 minutes. Meanwhile, the Mn/TiO2 catalyst inhibited the degradation of methylene blue. The increased activity by Ag dopants is due to the Localized Electromagnetic Field (LEMF) and Schottky barrier phenomena which increase charge separation. Meanwhile, decreased activity by Mn dopants is due to the shading effect and Mn electronic structure that can facilitate recombination at high loading. Ag/TiO2 catalyst also improved photodegradation performance of TiO2 when irradiated by visible light.