bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extraction of copper ions from aqueous solutions with oleic acid as green solvent
Authors: Halim S F A , Chang S H , Ahmad S K N 
Published: December 2019

Abstract
This research aimed to extract copper ions from aqueous solutions with oleic acid as a green solvent. The effects of pH equilibrium, temperature, and sodium sulphate (Na2SO4) concentration were investigated and the optimum conditions for maximum extraction of copper ions were determined. The findings revealed that the extraction of copper ions increased with equilibrium pH and temperature before it reached a plateau, while it increased and achieved a peak before it decreased with sodium salt concentration. The highest extraction of copper ions was achieved at 94% under the following optimum conditions: equilibrium pH of 4, temperature 55°C and 400 mM of Na2SO4. Therefore, it can be concluded that oleic acid is a potential green solvent for extracting copper ions from aqueous solutions.
Effect of MgO on characterizations and mechanical properties of red soil as oxygen carrier in chemical looping combustion
Authors: Selvarajoo K , Afandi N F , Manap A , Zainuddin R A , Mahalingam S , Kadir N F 
Published: December 2019

Abstract
Red soil is a type of soil that rich in iron and abundantly can be found in Malaysia. However, the application of red soil is limited to agriculture, building blocks, road building and waste water treatment. Chemical looping combustion (CLC) is one of the carbon-capturing technology, in which oxygen from oxygen carrier reacts with fuel inside fuel reactor to produce pure CO2 and H2O. In this research, effect of MgO as supported material was investigated in order to produce desired oxygen carrier from red soil. The composition of 95:05, 90:10, 80:20 and 70:30 of red soil and MgO, respectively, was varied in this research. The phase analysis, morphology, surface area and pore volume size were investigated using X-ray, Field Emission Scanning Electron Microscopy (FESEM) and Brunauer-Emmett-Teller (BET) analysis, respectively. From this study, composition of 90:10 of red soil and MgO, respectively, was found to have high surface area which is 56.95 m2/g with pore volume size of 0.145 cm3/g, and has low crystallite size which favourable as oxygen carrier.
Decolorization of Acid Red 1 using natural zeolite via heterogeneous fenton-like oxidation
Authors: Hassan H , Zahidi M M 
Published: December 2019

Abstract
Fenton process can be regarded as powerful and effective method in decolorization and mineralization of dye pollutants. However, this method is restricted with the generation of iron waste sludge which require secondary treatment. This limitation can be overcome by utilizing heterogeneous Fenton process where iron ions are immobilized onto the catalyst support. In the present study, the heterogeneous Fenton-like oxidation using Fe-natural zeolite (Fe-NZ) was investigated in decolorization of azo dye Acid Red 1 (AR1). The effects of iron ions loading, catalyst dose and initial pH on the decolorization of AR1 were evaluated. The maximum decolorization efficiency of 99.60% was achieved at 0.80 wt% of iron ions loading, 5.0 g/L of catalyst dose, and at 2.5 initial pH. The Fe-NZ showed high catalytic performance for decolorization of AR1 and could be regarded as a suitable low-cost catalyst in heterogeneous Fenton-like reaction.
Characterization of energy content in food waste by using thermogravimetric analyser (TGA) and elemental analyser (CHNS-O)
Authors: Ahmad N , Sahrin N , Talib N , Abdul Ghani FS 
Published: December 2019

Abstract
Food waste samples from various categories were examined for their energy content. In this work, the objective was to characterize the energy contents in food waste to assess their potential for renewable energy resources. The food waste samples that were analysed included tofu, carrot, corn, chicken, biscuit, rice and beef. The food wastes were characterized by proximate analysis using Thermogravimetric Analyser (TGA) and by ultimate analysis using Elemental Analyser (CHNS-O). The energy content in food waste was then evaluated using various higher heating value (HHV) correlations that were researched and established by many researchers. The results from both analyses demonstrated that the energy content from the higher heating value (HHV) calculated by using different equations indicated the food waste usage as an energy source. The highest HHV was found in the beef. Among the samples prepared, it can be observed that the most efficient ‘waste-to-energy’ sample is the protein-based food because this food has the highest amount of volatile matter with the lowest amount of ash content and fixed carbon content. Plus, protein food gives the highest percentages of carbon and hydrogen elements in order to help the combustion process going perfectly in order to convert it into an energy source.
Effect of organic antifoam’s concentrations on filtration performance
Authors: Mohamad Pauzi S , Anak Halbert D , Azizi S , Ahmad N A A , Ahmad N , Marpani F 
Published: December 2019

Abstract
The use of membranes is widely common in bioprocess industry to separate constituents of a liquid, especially during cell clarification process. Many has opted for normal flow filtration mode for this process due to the ease of handling of this technique as compared to tangential flow filtration. Meanwhile, antifoams are chemicals used in upstream process to eliminate the formation of foam throughout the course. It is normally used in conjunction with a nutrient rich broth that is used as a media to cultivate the cells. Some has claimed that antifoam may lead to premature membrane fouling, but some reported that the presence of antifoam may assist and improve the flux rate of the filtration process. This study investigates the effects of organic antifoam presence in a cell-free media on the performance of the filtration process, specifically normal flow filtration process. It was discovered that the presence of organic antifoam may be significant at 1.0% concentration of antifoam loaded in the sample which gives filtration capacity of 250L/m2 while filtration capacity was reported to be at 330L/m2 for samples containing 0.2% and 0.6% antifoam concentration. The flux rate profile has lower percentage reduction that ranges from 18% to 33% which resulted to final flux rate of approximately 700 – 800LMH for initial flux rate of 1000LMH and 27% to 46% reduction that lead to final flux rate of approximately 1000 – 1500 LMH for initial flux rate of 2000LMH.
Characteristics of chromium based mixed oxide catalyst in biodiesel production
Authors: Ali Bashah N A , Luin A , Jalaluddin I A , Shahhaizad I A , Ismail N F , Wan Kamis W Z 
Published: December 2019

Abstract
Renewable energy from biodiesel or fatty acid methyl ester (FAME) has become important in recent decades as one of the promising alternative for petroleum-derived fuel. In this study, chromium based mixed oxide catalysts which are Cr/Ca oxide and Cr/Zn oxide were synthesized via precipitation method and used in the transesterification of cooking palm oil to produce FAME. The reactions were conducted in a batch reactor at temperature of 60 °C, methanol:oil molar ratio of 6:1 and catalyst loading of 1wt%. The characterization through N2 adsorption-desorption showed BET-surface area, pore volume and pore size of Cr/Ca oxide are 3.6915 m2/g, 0.00684 cm3/g and 93.919Å, respectively while for Cr/Zn oxide are 3.9897 m2/g, 0.00630 cm3/g and 80.113Å, respectively. Both catalysts showed similar type isotherm which are type IV and hysterisis loop H3. The catalyst Cr/Ca oxide is found to be more active in the transesterication whereby FAME content of 27.8% was achieved compared to 7.4% by utilizing Cr/Zn oxide. The results showed that Cr/Ca oxide catalyst and Cr/Zn oxide have potential as heterogeneous catalyst to produce FAME from palm oil.
Sonocatalytic degradation of caffeine using CeO2 catalyst: parametric and reusability studies
Authors: Nur Fadzeelah A K , Abdullah A Z , Zubir N A , Abd Razak A H , Azha N A 
Published: December 2019

Abstract
This work examined sonocatalytic degradation of caffeine in the presence of CeO2 prepared by hydrothermal method. Several characterization techniques were used to study the CeO2 including TEM, XRD and BET method. Effects of various parameters such as pH, initial concentration of caffeine and dosage of CeO2 were investigated. This study also examined the reusability of CeO2. Results showed that the CeO2 had mixed shapes of crystallites consisting of rods and cubes with the specific surface area (Sbet) and pore volume of 126.63 m2/g and 0.4898 cm3/g, respectively. About 95.5% of caffeine degradation was achieved under the best parameter conditions i.e. at pH of 7.5, 5.0 mg/L of initial concentration of caffeine and 1.0 g/L of CeO2 dosage within 150 min. It was also revealed that the operating parameters played major roles in caffeine degradation efficiency. In addition, the CeO2 were quite stable since the efficiency of caffeine degradation achieved in the third cycle was 81.4%.
The effect of fibre loading on the physical and mechanical properties of Pineapple Leaf Fibre-reinforced biodegradable composites
Authors: Razali N , Aseri N A S , Dalingam S , Kamarolzaman A A 
Published: December 2019

Abstract
Recently, research on the development of biodegradable material were performed. However, biodegradable materials have a crucial weakness in terms of mechanical properties, but it can be improved by adding reinforcement material as filler. In this study, Pineapple Leaf Fibre(PALF) was chosen as filler due to its many advantages, such as low cost, variety and redundant sources and bio-degradable. The objective of this research is to investigate the effect of PALF fibre loading to the corn starch composites in terms of physical, mechanical and morphological properties. The samples were prepared at different fibre loadings: 5 wt%, to70 wt %, and were fabricated by using the hot press machine. The result showed that physical properties, such as density, water absorption and moisture content, were affected by different fibre loadings. Mechanical properties of the composite samples showed that PALF with 30 wt% gave the optimum tensile strength and modulus. Morphological analysis, composite samples of 30 wt% PALF fibre loading had fewer gaps between matrix and fibre. It can be concluded that 30 wt% of fibre loading is the optimum fibre loading for 3cm length PALF as compared to other composition ratios.
High resolution time domain reflectometry and coaxial cable for soil nail monitoring
Authors: Ng W K , Ashaari Y , Norshazrul M Y 
Published: December 2019

Abstract
Soil nailing is a popular application in soil slope stabilization. Failure of soil nailing could be mainly due to the issue of installation such as inaccuracy of actual length of the soil nail and integrity of cement grout annulus during grouting. This study focuses on using non-destructive technique of time domain reflectrometry (TDR) to monitor the quality of soil nail. TDR is originally used to detect changes in geometry and electromagnetic properties (dielectric or magnetic) happening along its transmission cable and detect the damage or leakage from the cable. The objective of this study is to use high resolution TDR and coaxial cable to detect changes of grout condition in soil nail. Results confirm the suitability of high resolution TDR and coaxial cable to detect void length which relates to grout condition in soil nail. The findings conclude that high resolution TDR model T631 and coaxial cable type RG-6 are capable to detect even small size void and is suitable to be applied for soil nail monitoring.
Dynamics of quantized rings and loops after reconnection in superfluid helium
Authors: Andryushchenko V A 
Published: December 2019

Abstract
The presented work is devoted to the study of the motion of vortex loops after reconnection in superfluid helium. The helium temperature as well as the initial arrangement of the vortex loops varied. The data on the change in the length, average radius of curvature and velocity of vortex loops from the moment of reconnection to the moment of their collapse were obtained. A comparative analysis of the motion of a single vortex ring and a deformed vortex loop was carried out. All calculations were performed within the framework of the vortex filament method using the full Biot-Savard equation.
Large eddy simulation of the vortex breakdown in a turbulent swirling jet
Authors: Borynyak K I 
Published: December 2019

Abstract
The paper presents the results of Large eddy simulation of a free swirling jet with Reynolds number Re = 104 for different swirl numbers. The swirl is organized via the rotation of the nozzle. The case has been divided onto two parts: rotating tube with honeycomb section using dynamic mesh and jet simulation with rotating nozzle using the initial conditions obtained in first part. Simulations were carried for six swirl numbers: 0, 0.15, 0.225, 0.3, 0.46, 0.63. The vortex breakdown with a central recirculation zone formation is observed in the last case.
Harmonic frequency analysis in turbulent double-cavity flow
Authors: Goltsman A E , Saushin I I 
Published: December 2019

Abstract
Flow structure in a turbulent double-cavity flow was reported previously by Goltsman et al. (Physics of Fluids (2019) 31:6) as part I. The results of harmonic frequency analysis of the flow regimes in double symmetric cavities for a wide range of shape factor and Reynolds number based on the cavity length were obtained experimentally and numerically. The frequencies and amplitudes of the main harmonics of the oscillogram were determined; the fields of the Strouhal number and the relative amplitudes of the main harmonic were presented.
Modelling of pulverized coal injection combustion process in the validation test rig using the Euler-Lagrangian approach
Authors: Koshelev K B , Strijhak S V 
Published: December 2019

Abstract
The combustion of pulverized coal is widely used in ironmaking blast furnaces. The pulverized coal has become a very important fuel. Most of the combustion models for the domain zone blast furnaces are based on CFD-LPT approach. In the Eulerian-Lagrangian approach, the continuous phase is treated as a continuum by solving the Navier-Stokes equations and the conservation equations for mass momentum and heat; the dispersed phase is calculated by tracking a large number of particles that follow Newton second law. The coalChemistryFoam solver was used to calculate the flow parameters in the test blast furnace combustion chamber (validation test rig). A system of equations based on the URANS model and the k-ε model of turbulence was used. The gmsh utility was used to build the computational grid. The temperature, velocity fields for gas and solid particles, concentrations fields of gas in particles and ash in particles have been calculated for given flow rate of coal particles in the valid test rig. The calculations were run on a computing cluster of the web-laboratory of UNICFD ISP RAS. Each calculation was performed on 48-64 cpu cores.
Flow around the wing models with straight and swept leading edge in case of contact with turbulent wake
Authors: Pavlenko A M , Zanin B Yu , Bykov A V , Katasonov M M 
Published: December 2019

Abstract
The paper presents the results of experimental studies of the flow around wing models with a straight and swept leading edge in contact with a turbulent wake. The experiments were carried out in subsonic wind tunnels at low Reynolds numbers. A fluffy thread was used to simulate a turbulent wake in the flow. The flow patterns on the surface of the wings were obtained before and after the impact of the turbulent wake at various angles of attack, wing sweep angles and free-stream velocity values. It was found that the wake has a significant effect on flow separation and on vortex structures arising above the wings. The evolution of the vortex flow patterns in the areas of separation of the boundary layer and with a change in the flow regime is shown.
Multi-spectral planar imaging using a tuneable Lyot-Ehman filter
Authors: Sharaborin D K , Dulin V M 
Published: December 2019

Abstract
The paper provides results of the assessment of a multi-spectral 2D imaging by using a tuneable band-pass optical filter. The filter is based on the Lyot-Ehman physical principles and uses liquid crystal cells as polarization rotators. The spectral properties of the filter are tested by imaging fluorescence of a Rhodamine dye solution. Full width at half maximum of the band of the filter was found to be 9-10 nm in the tested range of 520-620 nm. The filter is applied for 2D imaging of local spontaneous Raman scattering in a laminar premixed Bunsen flame. It is shown that the local intensity of Stokes and anti-Stokes components of rovibrational transitions during the light scattering by nitrogen molecules can be captured by using this filter. It is also concluded that the filter can be used for 2D imaging of local fluorescence in gases or liquids.
Investigation of unsteady flow regime in a T-shaped channel by means of Time-Resolved PLIF and PIV techniques
Authors: Shestakov M V 
Published: December 2019

Abstract
T-shaped channels are widely used as micro-mixers in microfluidic systems for chemical and biochemical engineering applications. The mixing efficiency of T-shaped channels relies on three-dimensional flow structure which is dependent on Reynolds number. The most favourable flow regime with relation to the mixing efficiency is an unsteady engulfment flow regime, which has a periodic nature. In the present work, the spatial and temporal scales formed in a T-shaped channel are studied at Reynolds number corresponding to unsteady three-dimensional flow regime. The combination of PLIF and PIV techniques with the high temporal resolution was used in the T-channel cross-sections to investigate the evolution of velocity and concentration fields.
Applying phase averaging technique to analysis of unsteady twin vortex structure observed in tangential vortex chamber
Authors: Skripkin S G , Dremov S V , Shtork S I 
Published: December 2019

Abstract
This paper is devoted to experimental investigation of formation of precessing vortices pair in a vortex chamber with a cylindrical working area. Flow structure was registered by means of a high-speed visualization technique. Quantitative measurements characterizing the vortex properties were carried out using a 2D particle image velocimetry (PIV) technique synchronized with wall pressure measurements. The results show that two symmetrical precessing helical vortices are present downstream of the tangential nozzles.The phase- averaged analysis confirms the presence of large-scale twin vortex structure that visualized by small air bubbles dissolved in water.
Flow structure and heat transfer around the cube
Authors: Terekhov V V , Bogatko T V , Korobkov S V 
Published: December 2019

Abstract
In this paper we present the results of a numerical study of convective heat transfer from a single cube, located on a plane surface perpendicular to the incoming flow. The Reynolds numbers, calculated from the height of the cube and the average velocity, are Re = 4200 and 46400. Numerical simulation is performed using the RANS and LES methods. The working fluid is air. Thermal condition on a flat surface and on the cube faces is a constant heat flux. A three-dimensional picture of the structure of the horseshoe-shaped vortex around the cube is clearly shown. Areas with maximum pressure loads on the surface of the cube are identified. The main attention is paid to the peculiarities of heat transfer in the flow around a cube with a turbulent flow. Areas on the cube surface where the most effective heat transfer occurs, as well as low-efficiency stagnant zones with low fluid velocity and high temperatures are shown. The obtained data on aerodynamics and heat transfer are compared with the experimental data of other authors.
The structure of separated flow and heat transfer in a round tube with single detached diaphragm
Authors: Terekhov V I , Bogatko T V 
Published: December 2019

Abstract
Here we present the results of numerical investigation of the flow structure and turbulent heat transfer obtained in a round tube with a diaphragm of height h and some gap c between the tube and the diaphragm. The value of gap between the diaphragm and tube wall was changed within A = c/h = 0 ÷ 0.33. It was defined that an increased distance between the diaphragm and the tube wall modifies the structure of recirculation zone and eliminates the stagnation areas in the region of secondary vortices. The flow regime, when the values of average heat transfer behind the diaphragm with a gap are higher than the same values for the attached rib, was determined. When increasing the gap height from 0 to 0.33, the 30-% increment in the coefficient of thermal enhancement was achieved.
The development of instability of Richtmyer–Meshkov in the interaction of a shock wave with a two-component medium consisting of light and heavy gas
Authors: Zyryanov K I , Ruev G A 
Published: December 2019

Abstract
On the basis of the previously formulated mathematical model of the mechanics of a two-speed two-temperature mixture of light and heavy gases, the evolution of a system of two cylinders of heavy gas after the passage of a shock wave through it is numerically investigated. The analysis of the obtained data on the dependence of the spatial expansion on time, as well as the kinematic characteristics of the system showed their satisfactory compliance with the experimental data for all initial separations of the cylinders. The influence of the initial separation of cylinders on the flow morphology is investigated.
Influence of detailed mechanisms of chemical kinetics on propagation and stability of detonation wave in H2/O2 mixture
Authors: Borisov S P , Kudryavtsev A N , Shershnev A A 
Published: December 2019

Abstract
In the present paper, detonation in a stoichiometric oxygen-hydrogen mixture is simulated numerically using 4 detailed chemical mechanisms. The effect of chemical kinetics models on the stability of 1D detonation wave and 2D detonation wave propagating in a plane channel is investigated. The number of detonation cells formed in a channel of a given width at different degrees of overdrive is determined. Simulations are performed using a previously developed computational program based on high-order shock-capturing TVD schemes and a finite-rate chemistry solver. The program is implemented in C++ using the CUDA parallel computing platform for running on graphic processor devices (GPU), the open OpenMP standard for multi-threaded applications on multiprocessor systems with shared memory and the MPI protocol for data exchange between processors.
Numerical simulation of synthesis gas/air and methane/air flames for model combustion chamber with swirling flow
Authors: Lobasov A S , Dekterev Ar A , Minakov A V 
Published: December 2019

Abstract
This paper reports on the investigation of combustion features of synthesis gas/air and methane/air flames in a model gas turbine combustor with swirling flow via numerical simulation. This combustor developed for experimental investigation of flow, heat transfer and combustion. For synthesis gas combustion ratio of hydrogen and carbon monoxide was 1:1. The equivalence ratio Φ in both cases was 1.5. The combustor contains systems for water- and air-cooling that provides reasonable temperature value of combustor walls in operating mode. The methane/air flame has the lifted V-shape and synthesis gas/air flame has the columnar tubular flame. In practical, the V-shape flames are more often used. To provide more practical combustion regimes for synthesis gas/air mixture it is necessary to increase the fuel-oxidant mixing efficiency in the premixer of the combustor.