bluuebunny/crossref_metadata_2025_split huggingface dataset:
Release of encapsulated citronella oil in Tween 80 solution
Authors: Ariff S B M , Jai J , Jamaludin S K , Ibrahim N 
Published: December 2019

Abstract
Microencapsulation is a technique in which small particles are enclosed by a coating wall. Microencapsulation has been widely used in applications such as the controllable release of essential oils and improvement of the stability of the core substances and many other fields. Volatiles liquids and solids are easily damaged during long term use, due to their external environment. This leads to degradation and loss of function. In preventing this drawback, encapsulation of essential oils by embedding them into polymer wall has been introduced. In this study, citronella oil (CO) encapsulated by gelatin-chitosan was prepared by complex coacervation technique. Report on release study of encapsulated CO and its applications in floor cleaning solution is very limited. Hence, release rate and release mechanism of the microcapsules in simulated floor cleaning solution (Tween 80 solution) were investigated. Morphology of the microcapsules was determined through optical microscope. The release of CO was observed through the formation of rupture on the spherical microcapsule. The release rate of encapsulated CO increases with the increase of temperature from 25°C to 75°C. The release mechanism of the CO, based on Fick’s law was classified as following the Korsmeyer-Peppas controlled release model of super case II, whereby the release is due to wall erosion.
Characterization of food waste and empty fruit bunches (EFB) for anaerobic digestion application
Authors: Hamzah M A A , Alias A B , Him N R N , Rashid Z A , Ghani W A W A K 
Published: December 2019

Abstract
Food waste (FW) and empty fruit bunches (EFB) possess a great potential to be used for anaerobic digestion process, as these two biomasses are rich in biodegradable organic matter, in which its contents play an important role in determining the efficiency of the digestion process. In this study, the elemental compositions, nutrients content, and lignocellulosic content of Malaysian FW and EFB were determined by running several procedures and were compared to past literatures which also used similar feedstock for anaerobic digestion; to determine whether the biomasses used in this study could lead to better performance of anaerobic digestion. Elemental analysis of the FW showed that the C/N ratio ranged from 4.45 to 15.45, within the optimum range as defined by past studies. For EFB, the C/N ratio was similar to FW, making EFB suitable to be mixed with FW for optimum anaerobic digestion conditions. Nutrients analysis of the FW showed that FW Types A and D, rice waste and food waste mixture respectively, possessed the most balanced carbohydrates, proteins and lipids nutrients for optimum digestion. Lignocellulosic analysis of the EFB also proved that its contents were favourable to be used in anaerobic digestion; high cellulose content, low lignin content.
In silico analysis of essential and non-homologous proteins in Salmonella typhimurium biofilm
Authors: Othman N A , Yahya M F Z R 
Published: December 2019

Abstract

Salmonella typhimurium is a Gram negative pathogen that commonly causes severe gastroenteritis. It is resistant to a wide range of antibiotics and is able to form biofilm on both biotic and abiotic surfaces. To date, essential and non-homologous proteins in S. typhimurium biofilm remain not well investigated. Therefore, the present work was performed to analyze essential and non-homologous proteins in S. typhimurium biofilm using a combination of one-dimensional SDS-PAGE, HPLC - ESI - QTOF and bioinformatics. Results demonstrated that seven major protein bands (78.1 kDa, 51.2 kDa, 41.5 kDa, 37.3 kDa, 35.1 kDa, 27.6 kDa, and 25.4 kDa) were present in whole-cell protein extract of S. typhimurium biofilm. A total of 75 proteins were successfully identified from both 25.4 kDa and 51.2 kDa protein bands. Approximately 54.67% of QTOF-identified whole-cell proteins were found to be essential to the survival of S. typhimurium biofilm and were non-homologous to human proteome. Majority of essential and non-homologous S. typhimurium biofilm proteins were associated with transport and protein synthesis. The findings from the present work may be useful for development of novel antibiofilm agent.
Mechanical and corrosion properties of Mg-Zn/HAP/Al2O3hybrid composite
Authors: Ahmad F N , Rashid N , Zuhailawati H 
Published: December 2019

AbstractThe effect of HAP and Al2O3composition with constant of ceramic content of 15 wt. % on mechanical properties, microstructure, and corrosion behavior of degradable Mg-Zn/HAP/Al2O3hybrid composite developed by powder metallurgy method were investigated. The microstructure was analyzed using an optical microscope and scanning electronic microscope while mechanical properties were evaluated for density and compression strength. Meanwhile, corrosion behavior in Hank Balanced salt solution (HBSS) was studied for 4 h. The addition of HAP and Al2O3particles has improved the mechanical properties and corrosion properties of Mg-Zn alloy. The results show that 15 wt. % Al2O3(without HAP) shows the higher density, hardness, and compression. However, the composite consisted of 10 wt. % HAP with 5 wt. % Al2O3shows the lower corrosion rate.
Theoretical investigations of the structural and electronic properties of boron nitride clusters: DFT comparison of several basis sets
Authors: Toh P L , Wang S M 
Published: December 2019

Abstract
In this present study, Density Functional Theory (DFT) calculations were conducted to study the structural and electronic properties of (1,1), (2,2), (3,3), and (4,4) Boron Nitride (BN) systems. Geometry optimization calculations were carried out to find the stability of BN cluster models. The obtained structural geometries are consistent with that obtained in the previous reported results [1]. The total energies increase when the cluster sizes of BNs increase. For each cluster size of BN, the four total energy values obtained from B3LYP level of theory with employing the basis sets of 6-31++G, 6-31++G**, 6-311++G, and 6-311++G** are close to each. Moreover, our computations revealed that the gap energy values of HOMO-LUMOs in the BN cluster structures have been decreased by following its structure and dimensionality. The calculated HOMO-LUMO gaps are 5.99 eV - 7.68 eV in this study. For the diagrams of molecular electrostatic potential (MEP) surfaces, the regions around the N atoms at the center hold the highest electronegative potential, which can attract more electrons in the BN systems. With a Mulliken population analysis (MPA) scheme, all the boron atoms possess the positive charges, whereas the negative charges were found on the nitrogen atom in the BN systems.
Fabrication of TiO2-CuInS2 nanocomposite on ITO substrate via liquid carbon dioxide coating
Authors: Nursanto E B , Min B K , Kim J 
Published: December 2019

Abstract
TiO2-CuInS2 is one of the promising materials for 3D nanocomposite solar cells. To utilize for 3D nanocomposite solar cells, TiO2-CuInS2 should well deposited onto transparent conducting oxide such as indium doped tin oxide (ITO). High pressure coating with liquid carbondioxide (l-CO2) was successfully deposited TiO2-metals chalcogenide onto ITO substrate. Further heat treatment (oxidation and sulfurization) lead the formation of CuInS2 from metals chalcogenide deposited on the mesoporous TiO2. The formation of CuInS2 on the was confirmed by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) and Raman spectroscopy. The atomic ratios of deposited CuInS2 were nearly stoichiometric after sulfurization. The crystal growths of CuInS2 were controlled by adjusting the number of coating cycles.
Mathematical modelling of drying kinetics of oven dried Hibiscus Sabdariffa seed
Authors: Ismail N F , Mat Nawi H N , Zainuddin N 
Published: December 2019

Abstract

Hibiscus sabdariffa or Roselle seed is an agricultural product which possesses a large amount of nutritional content that could be useful in wide application. Drying process can be helpful to conserve the seeds for long storage periods. For this reason, the drying behavior of Roselle seeds was investigated using laboratory oven at various drying temperatures (35, 45, 55, 60 and 65°C). It is found that the drying process of the Roselle seeds consists of constant rate and mostly falling rate period at where the moisture content of Roselle seed decreases as time goes. Adequately suitable drying temperature is found to be 65°C with the drying time of 240 minutes. The drying behavior of Roselle seeds is further understood through the drying kinetics of the Roselle seeds. Five empirical mathematical models were selected to describe and compare the drying characteristics of Roselle seeds at respective drying temperatures. Drying rate constants, coefficients and statistical parameters were determined by non-linear regression analysis, and therefore, the diffusion approach model was selected as the best model with R value obtained is 0.999 while MBE, RMSE and χ2 values of 2.37E-04, 0.01335 and 0.007794 respectively.
Life cycle assessment approach to sustainable sewage sludge management for water pollution control
Authors: Mu’azu N D , Essa M H , Aga O , Jarrah N 
Published: December 2019

Abstract
Increase in population growth coupled with industrialization, urbanization and requirements for implementation of stricter effluent discharge standards, sludge from wastewater treatment plants (WWTP) is expected to be produced in a continually increasing amount globally. The management of the huge volume of sludge generation becomes an integral component of environmental sustainability. Therefore, the need for environmentally friendly approach to sludge management strategy couldn’t be overemphasized. This paper proposes a rational and more sustainable approach directed towards devising means to solve the problem of the huge amount of WWTPs sludge by converting it to granular activated carbon (GAC) for utilization in water pollution control via incorporating Life Cycle Assessment (LCA). The paper reviews the various approaches and techniques for drying, pyrolysis and activation techniques and the best operating conditions for sludge based activated carbon (SBAC) for optimal pollution control. Based on that, a holistic decision making tool was recommended which incorporates major production, treatment and disposal options for each stage using Life Cycle Assessment (LCA) approach (from-cradle-to-grave), from which wide range of alternative scenarios will be generated vis-à-vis water pollution control efficacy in relation to environmental, cost as well as energy implications.
Removal zinc ions from contaminated soil using biodegradable polyaspartate via soil washing process
Authors: Mu’azu N D , Essa M H , Haladu S A , Ali S A , Jarrah N , Zubair M , Mohamed I A 
Published: December 2019

Abstract
This work reports the potential use of polyaspartate (PASP) synthesized from L-aspartic acid via a newly modified thermal procedure as a soil washing chelating agent for Zn ions removal from contaminated-soil. Response surface methodology (RSM) via faced central composite design was employed for evaluating and optimizing the influence of operational parameters. RSM response models developed describe well the Zn removal efficiency with high R2 (> 0.994-0.998; p-values < 0.001) and in-significant lack of fit. Zn washing efficiency was found to increase with increase in Zn initial concentration and decrease in PASP/soil ratio. The relative contribution of the operating conditions on Zn removal follows the order; PASP/soil ratio, initial heavy metal concentration, PASP concentration, initial pH and extraction time. Optimal conditions occurred at 500 mg/kg Zn concentration, 36 mM PASP concentration, 10 polymer-soil ratio, pH 4 and 6 hours retention time when Zn ions removal was 39% with most efficient PASP utilization. Although, 100% removal of Zn was achieved at low Zn concentration (100 mg/kg), yet, more amount of the PASP was needed. These results demonstrated the feasibility of effective utilization of PASP for decontamination of Zn ions polluted soils.
The time dependences of the main properties of the vortex loops just after reconnection in superfluid helium
Authors: Andryushchenko V A , Kondaurova L P 
Published: December 2019

Abstract
We investigate a single vortex reconnection event in superfluid helium at zero temperature, when mutual friction is absent, and at 1.9 K temperature, when mutual friction essentially changes the evolution of lines. The vortex filament method with full Biot-Savart equation is used for numerical investigation of the time dependences of the main properties of the vortex loops just after reconnection. In this paper, we present the obtained dependencies of the average curvature of the loop, Lamb momentum, angular momentum, and energy from time. The effect of mutual friction force and initial conditions on these properties is studied.
Features of convective heat transfer in mixed convection regimes in the Czochralski method with different effects of buoyancy forces and thermocapillary effect
Authors: Berdnikov V S , Vinokurov V V , Vinokurov V A 
Published: December 2019

Abstract
The influence of the height of the melt layer on the boundary of the transition from stationary flow and heat exchange to non-stationary regimes for given values of Grashof, Marangoni and Reynolds numbers is investigated. The hydrodynamics, local and integral heat transfer were studied at the value of the Prandtl number 16. At the values of the Prandtl number 10.78; 16 and 45.6, integral heat transfer was studied at a fixed height of the melt layer with increasing Reynolds numbers.
Dynamics of fluidic oscillator jet: LES study
Authors: Dauengauer E I , Mullyadzhanov R I 
Published: December 2019

Abstract
We study a turbulent jet generated by a fluidic oscillator using Large-eddy simulations in a range of Reynolds numbers Red
= 3000−30000. The device represents Φ-shaped configuration providing a strongly unsteady flow due to periodic oscillations based on the Coanda effect. Several simulation results are presented for a mesh convergence study, the analysis of the time-averaged statistics as well as the oscillation frequency against Red
.
The influence of high degree of turbulence on the near wake of the streamlined cylinder
Authors: Dobroselsky K G 
Published: December 2019

Abstract
A method for obtaining high degree of water flow turbulence using semi-cylindrical inserts is shown. The degree of longitudinal turbulence in the flow core of about 20% was obtained under the conditions of the limited size of the working section of the hydrodynamic stand and small overpressure. The PIV method was used to obtain the average characteristics of the near wake behind the cylinder, streamlined by weakly and strongly turbulized flow in the subcritical region. The resulting size of the vortex zone behind the cylinder in the flow with high degree of turbulence is much smaller than in the case of weak turbulence, which is similar to the flow with effective Reynolds number in the region of critical numbers, where the resistance drops sharply.
Numerical optimization of hydrogen microwave plasma reactor for diamond film deposition
Authors: Hrebtov M Yu , Bobrov M S 
Published: December 2019

Abstract
We present the results of optimization of microwave plasma generation in a prototypical diamond film deposition device by means of numerical simulation. The modification of the device was done by changing the shape of microwave resonant chamber, where the plasma generation occurs, in a way to focus the discharge near the outlet nozzle. The best results were obtained for a configuration with an addition of a conducting rod located on the axis of the chamber. This modified configuration provided a two orders of magnitude increase in electron number density near the nozzle exit and about 10 time increase (up to 5%) in dissociation degree of hydrogen molecules.
Investigation of the finite size core helical vortex filament moving in cylindrical channel
Authors: Kashkarova M V , Kuibin P A , Kravtsova A Yu 
Published: December 2019

Abstract
A mathematical analysis of the problem on finding the shape of the core of an equilibrium helical vortex moving in a cylindrical tube has been carried out. Within the core, the vorticity was considered constant. The vorticity distribution was approximated by the Heaviside function. Integral equation for the vortex core boundary and stream function is formulated. An approximate solution on the stream function is found for the case of a circular section of the vortex core. An algorithm developed for the vortex ring [2] is adopted for solution of the problem under consideration.
The heat transfer of round impinging jets
Authors: Lemanov V V , Terekhov V V , Terekhov V I 
Published: December 2019

Abstract
Heat transfer of round impinging jets has been investigated in a wide range of Reynolds numbers (Re=40-21000). A jet flowing out of a profiled nozzle and a long tube at a constant wall temperature and at a distance to the obstacle h/d=1-20 was studied. In experiments at Re<3000 for an outflow from the tube, a noticeable increase in heat transfer by 200-400% is observed, compared with the case when the jet flows out of the nozzle. At Re>3000, the difference in heat transfer for the two variants of jet formation (from the tube and from the nozzle) decreases asymptotically. For laminar and turbulent flow modes, the results of numerical calculations are consistent with the experimental data.
Microstructure of flow in a channel with low-profile spanwise ribs
Authors: Mikheev N I , Dushin N S , Dushina O A 
Published: December 2019

Abstract
The paper presents the experimental data on velocity fluctuation spectra and reattachment lengths observed in turbulent flows past low-profile elements of discrete roughness mounted on the wall. The discrete roughness elements were shaped as semicircular spanwise ribs with the height of 2% of the hydraulic diameter of the channel. It has been revealed that such ribs make the velocity fluctuations increase manifold at the height of rib tops in the range of non-dimensional frequency St=0.6-1.2 that favors the reattachment length reduction and heat transfer augmentation.
Flow structure behind a spanwise rib in channels of different geometry at moderate Reynolds numbers
Authors: Molochnikov V M , Mazo A B , Maluykov A V , Kalinin E I 
Published: December 2019

Abstract
Experimental study of laminar-turbulent transition in a rectangular channel with a semicircular rib has been carried out. The study comprised the flow visualization as well as direct numerical simulation of some flow configurations. The paper investigates the effect of the channel geometry (width and height), aspect ratio of the rib and blockage ratio on the mechanisms of transition to turbulence, formation of large vortical structures in the mixing layer behind the rib and on the critical Reynolds number at which the transition to turbulence occurs.
DNS of heat transfer of the flow over a cylinder at Re = 200 and 1000
Authors: Palkin E , Ryzhenkov V , Mullyadzhanov R 
Published: December 2019

Abstract
We perform Direct numerical simulations of the flow over a cylinder to study the influence of the thermal boundary conditions on the Nusselt number distribution. The results show very good agreement with some data from the literature. The total Nusselt number for the constant heat flux (CHF) boundary condition is higher for some 15% than for the constant wall temperature (CWT) condition for both Re < 200 and 1000.
Modeling the closed circulation of thermal water
Authors: Pen’kovskii V I , Korsakova N K 
Published: December 2019

Abstract
Two schemes of closed circulation of thermal waters are considered. The first scheme is filtration in a single stratum. In the second scheme, the flow in a formation with a weakly permeable bottom is considered. The effective for designers formulas are obtained. The thermal formation model is used in the form of a heterogeneous structure consisting of two embedding continuums.
Generalized correlations for predicting heat transfer and friction factor of turbulent flow in tubes with inner helical ribs
Authors: Popov I A , Skrypnik A N , Schelchkov A V 
Published: December 2019

Abstract
Generalized correlations for predicting heat transfer and pressure drop for turbulent flow of Newtonian fluid through tubes with inner helical ribs are presented. A comparison with existing correlations in the literature shows that revealed correlations allow decreasing the data deviation and cover the wide ranges of working fluids, operational conditions, and different dimensions of helical ribs.
The asymmetry of the recirculation zone of the annular jet with different diameter ratio
Authors: Ryzhenkov V O , Abdurakipov S S , Mullyadzhanov R I 
Published: December 2019

Abstract
We performed direct numerical simulations of the annular turbulent jet flow for the Reynolds number based on the bulk velocity inside the nozzle and its outer diameter Re = 8900 with three different values of the inner-to-outer diameter ratio a = d / D = 0.3, 0.5, 0.7. The size of the reversal flow region, the fluctuation level and mixing rate increase with the increase of the diameter ratio. For all the cases of geometry parameters the symmetry breaking phenomenon was detected. The degree of asymmetry increases with the increase of the diameter ratio resulting in the displacement of the global stagnation points form the axis of symmetry and the deflection of the averaged streamlines from the jet axis.
The influence of tabs on fluid dynamic measurements downstream of a backward-facing step
Authors: Terekhov V I , Sharov K A , Smulsky Ya J , Dyachenko A Yu 
Published: December 2019

Abstract
PIV-method was used to study the flow behind a backward-facing step in the presence of tabs for the Reynolds number Re=4000. The studied tabs had rectangular shape and a height of 6 mm, and were installed with a step of 25 and 50 mm. The tabs, depending on the step, had a different effect on velocity profile. At the tab location, the profiles of the average longitudinal and transverse velocity were strongly deformed and became similar to the behaviour behind the solid rib. In the area between the tabs due to the adjacent pair of tab-induced vortices, the attachment of the mixing layer occurred earlier than at streamlining of a smooth step. The recirculation area was noticeably reduced for tabs with spacing of 50 mm, and at the same time, with a reduction in the distance between them to 25 mm, the size of this zone increased.
Evolution of a localized wave packet in the boundary layer of the swept wing at M = 2
Authors: Yatskikh A A , Ermolaev Y G , Smorodsky B V , Panina A V , Semionov N V , Kosinov A D 
Published: December 2019

Abstract
The evolution of an artificial localized wave packet in a supersonic boundary layer of a swept wing is experimentally investigated at Mach number M = 2. The wave characteristics of the development of disturbances at various frequencies are determined. The growth increments of the most increasing modes of the wave packet are estimated. Comparison with the results of calculations based on the linear theory of stability is carried out.