bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphology and evolution of coronal holes at the wavelengths of 171 Å, 193 Å, and 211 Å in the Solar Cycle 24
Authors: Astuti I K D , Herdiwijaya D 
Published: June 2020

Abstract
Coronal holes are an area that appears dark in the corona, which is observable in EUV and X-ray wavelengths. This area has an open magnetic field structure. The magnetogram image showed that the coronal hole has one polarity (unipolar). Commonly, the shape and size of the coronal hole at the poles are related to the structural strength of the magnetic field. Because of this unipolar nature, the coronal hole becomes a source of the high-speed solar wind, which can cause a geomagnetic storm. The number, size, and position of the coronal hole vary as a function of the solar cycle, with the reversal of magnetic polarity every 11 years. The characteristics of the coronal hole will be different at the maximum and minimum phases of the solar cycle. Aims of this study are to determine the morphology of coronal hole based on the area, magnetic field strength, open magnetic flux, and the evolution of the coronal hole according to latitude during minimum solar activity (or spotless days) and maximum at the Solar Cycle 24. The method applied in this study is CHIMERA (Coronal Hole Identification via Multi-thermal Emission Recognition Algorithm). There are relations between magnetic field strength and magnetic flux with areas of coronal holes from September 2010 to May 2019 that follow the exponential and linear distributions.
Investigation of the latitudinal occurrence rate of ionospheric plasma bubble in case of strong and weak pre–reversal enhancement in Southeast Asia
Authors: Olla A , Abadi P , Srigutomo W 
Published: June 2020

Abstract
We used ionosonde and GPS receivers during March–April in 2004–2005 and 2011–2015 to investigate the latitudinal variation of equatorial plasma bubble (EPB) occurrence rate in cases of strong and weak pre-reversal enhancement (PRE). The ionosonde at Chumphon in Thailand was used to estimate the PRE strength. Ten GPS receivers in Southeast Asia, ranging from magnetic latitude (ML) of 4.4°S to 21.6°S, were used to investigate the latitudinal variation of EPB occurrence rate. In the case of strong PRE, the EPB occurrence rates decrease from 38.9% to 34.9% at ML of 4.4°S–7.2°S. Continuously, the occurrence rate increases and reaches the peak (44%) at ML of 9.3°S; afterward, the occurrence rate rapidly decreases and reaches below 5% at ML of 21.6°S. In the case of weak PRE, the occurrence rate decreases from 21.8% at ML of 4.4°S, seems constant (15.3%–16%) at ML of 8.2°S–12.1°S, and reaches less than 5% at ML of 16.1°S. Generally, the EPB occurrence rate and its latitudinal extension in case of strong PRE are higher than that in case of weak PRE. Interestingly, we found that the latitudinal occurrence rate peak of the EPB in case of strong is farther than that in case of weak PRE.
Al-Si-Zn Behaviouron Interface of AR500 Steel and AA7075 Aluminium Alloy BrazedJoint
Authors: Muhamed M. N. , Omar M.Z. , Abdullah S. , Sajuri Z. , Zamri W.F.H.W. 
Published: June 2020

AbstractThe brazing of steel and aluminium alloy using low melting point aluminium based fillers has been extensively studied and the technique has been used in many industries, especially the automotive industry. The strength and failure mode of AR500 steel and AA7075 aluminium alloy brazing joint using the Al-Si-Zn filler metal will be measured and calculated in this paper. However, the adverse effect of intermetallic phases formation on the joint strength has limited the application of this joining method.These dissimilar metals possessing a high strength joint would be of benefit to industry especially in reducing the weight of products. The torch brazing method using Al-Si-Zn base filler metal wasused to join AR500 steel and AA7075 aluminium alloy in this study. The intermetallic phase formation of the brazing on was investigated by scanning electron microscopy and the mechanical strength of the joints was evaluated by shear testing, flexural testing and low velocity impact testing. A maximum shear load of 6460 N was obtained. The presence of intermetallic phases was found to have some effect on the strength of the brazed joint. However, overall, this brazing process using Al-Si-Zn filler metal facilitates the joining of these dissimilar metals to improve the mechanical properties of the joint
Mechanical Properties of Hybrid FRP Arrangement of Glass and Kenaf fibres
Authors: Bahiyah Baba N. , Haikal Abdul Halim M. , Zin N.A.M. , Amin M.A.M. 
Published: June 2020

Abstract
The study discussed the mechanical properties of hybrid arrangement of glass and Kenaf fibre reinforced plastic (FRP). There are two types of hybrid arrangementscomparedwith one controlled arrangement of 100% Kenaf fibre. The glass fibre types used in the study are chopped, woven and 3-dimensional. The FRP was fabricated via hand lay-up method using the two types of matrix namely epoxy 1,2 and polyester resins. Parameters evaluated were fibre hybrid FRP arrangement and fibre orientation for the two types of composite with two different matrix resins. The mechanical properties evaluated on the hybrid FRP arrangement are tensile strength, elastic modulus, elongation at break and water absorption. The mechanical properties of 36 composites samples were conducted by Instrons Machine 3382 according to ASTM D-638-10a. The physical property of nine samples was performed using water absorption according to ASTM D 570-99. These tests were carried out to determine the effect of mechanical behaviour for all hybrid FRP arrangements. It was found that hybrid FRP arrangement #1 with layers of fibreglass 3D-woven-chopped-woven-3D give the outstanding properties both in polyester and epoxy matrices. However, adding Kenaf reduce the mechanical properties and increase water absorption.
Effect of Using Windscreen Glass Waste Powder (WGWP) As Cement Replacement on the Mechanical Properties of Mortar
Authors: Anisah N.N. , Awang M. , Kartini K. 
Published: June 2020

Abstract
Sustainability issues have obtained major attentions around the globe. In this regard, there are challenges which the cement and glass industries are facing due to the high greenhouse gases emissions, the intensive use of energy and the reduction of natural resources on earth. However, the chemical compositions and the pozzolanic properties of waste glass are very encouraging for its use in cement and concrete industries and to provide an environment-friendly solution. For sustainability, it is high time to look into the possibility of replacing cement with windscreen waste glass. A study was conducted on the effects of various proportions of windscreen glass waste powder (WGWP) on the compressive strength of mortar. The mortar was prepared by incorporating several compositions of WGWP (0%, 5%, 10%, 15% and 20% by weight of cement), while three cement to sand (C:S) ratios of 1:2.5, 1:3.0 and 1:3.5 were employed. Fixed water to cement (w/c) ratio of 0.5 was used for this study. The samples were water cured and the assessment of the strength performance of mortar cubes was carried out at 7 and 28 days. Results have shown that WGWP has good pozzolanic properties. In term of compressive strength, it was observed that employing C:S ratio of 1:3.0 is better than 1:2.5 and 1:3.5 of C:S ratio.
Synthesis of Biodiesel from Waste Cooking Oil by Alkali Catalyzed Transesterification
Authors: Shamsudin Mohd Syaharulhafizi Bin Sulong , Bin Abdul Aziz Azharin Shah , Dabwan Ahmed H. A. 
Published: June 2020

Abstract
Biodiesel is an alternative fuel to petroleum diesel because it is renewable sources and considered to be smart waste management solution for used cooking oil since plenty amount of waste cooking oil is being produced from households and restaurants. Irresponsible practice to get rid of this waste is by pouring it down the sink or drain. However this practice causes damage mainly to the ecosystem (water pollution). In this study, biodiesel was synthesized from waste cooking oil by alkali catalyzed transesterification method. Alkali transesterification is a reaction between oil and alcohol in presence of alkali catalyst. Methanol and sodium hydroxide were used in this transesterification. Treated oil and sodium methoxide mix at constant temperature for certain period to yield methyl ester and glycerin. Characterization was carried out by using thermal gravimetric analysis, differential scanning calorimetry, and normal analytical methods mainly for density and viscosity. This study shows that biodiesel was successfully synthesized from waste cooking oil and characterization of the synthesize biodiesel was almost similar to the conventional diesel. From this, it can be concluded that pollution caused by disposal of waste cooking oil can be turned into value-added product.
Cube Polygon: A New Modified Euler Method to Improve Accuracy of Ordinary Differential Equation (ODE)
Authors: Nooraida S. , Nurhafizah M.M.Y. , Anis M.S. , Fahmi A.M.M. , Syarul A.W.F. , Iliana A.M. 
Published: June 2020

Abstract
Ordinary Differential Equation (ODEs) problems can solve using Euler method. Euler method suitable for first-order numerical and it is an effective and easy method. The objective of this paper is to suggest a new scheme for better accuracy. The accuracy is determined by comparing with exact solution using average concept. This paper proposes Cube Polygon as modified Euler method to improved accuracy and complexity. A set of simulation were carried out to demonstrate the accuracy of the proposed method. Testing has been done into SCILAB 6.0 by recording the maximum error. Results indicate that Cube Polygon provide more accurate results and reducing complexity for both smaller and higher step size.
Influence of Sn dopant on ZnO Thin Film for Formaldehyde Detection
Authors: Ishak S , Johari S , Ramli M M 
Published: June 2020

Abstract
In this work, structural, morphological, electrical and gas sensing of ZnO and Sn doped ZnO thin film at different atomic percentage (0.5at%, 1.0at% and 1.5at%) had been studied. The precursor was prepared by sol-gel method and deposited on an IDE glass substrate by using spin coating technique. The effects of the dopant was then characterized through XRD, AFM, SEM and Agilent LCR Meter. Based on the XRD results, it was found that all films showed the highest diffraction peak intensity at (002) with crystallite size in the range of 8-33nm. Meanwhile the morphological properties from AFM and SEM showed an improvement in surface roughness from 16.7nm to 5.48nm and decrease the grain size from 45.42nm to 40.99nm in the presence of Sn dopant. Based on the image, the grains were uniformly distributed and ZnO thin film showed the hexagonal wurtzite structure, which proved the XRD result. Among all the samples, 1.0at% Sn doped showed the best result for detection of formaldehyde at 0.6ppm which up to 96% compare to undoped, 26.04% at 150°C. The response and recovery time was between 4-16 seconds. This showed that the presence of Sn can help to improve the conductivity of the ZnO thin film.
On the Investigations of Chip-on-Board Ultra-Violet Sensor by Screen Printing of GaN Powder
Authors: Beh Khi Poay , Kamarulakmal Nurul Liyana , Rasiman Nabihah , Abdalrheem Raed , Umar Muttakka , Yam Fong Kwong , Lim Hwee San , Hassan Zainuriah 
Published: June 2020

Abstract
In this work, the characteristics of a chip-on-board screen printed GaN UV sensor was investigated. On the sensing element, GaN powders were obtained through ammonolysis of Ga2O3 at 1000°C under NH3 flow. The UV sensor platform was prepared using soft-lithography method, resulted in patterned circuit board. For the screen printing process, GaN powder is mixed with ethylcellulose/ethanol, subsequently deposited on the electrode pairs. The pure GaN sensor exhibited oscillations and change in amplitude upon UV sensing. This could be ascribed to high intrinsic resistance and parasitic capacitance and inductance. To mitigate this effect, rGO fillers were added and showed discern responds. Both sensors (with and without rGO) showed sensitiviy at 300 and 30% respectively, while the current magnitude for the latter was 54 times higher than that of former.
Investigation of light trapping mechanism of Silicon solar cell performance utilizing Silvaco TCAD
Authors: Abd Rahim A F , Shamlan M , Mohd Razali N S , Radzali R , Mahmood A , Hamzah I H , Abu Bakar A 
Published: June 2020

Abstract
In this project, an investigation on the effect of difference shapes of the top surface silicon (Si) solar cell as an antireflective (AR) layer was carried out. Texturing the top surface of silicon solar cell helps to reduce light reflection from the solar cell. The different surface texturing which is planar structure, columnar structure and pyramid structure was created and simulated using Athena process simulator by SILVACO TCAD tools. The structures were then loaded into ATLAS device simulator to extract the electrical performance parameters of the solar cell. The results showed that the planar, pyramid and columnar structures of the Si solar cells exhibited efficiency of 2.04%, 2.18% and 2.39% respectively. The short circuit current, Isc, open circuit voltage, Voc and the maximum power, Pmax for the columnar structures are 2.35444 nA, 0.366605 V and 0.630363 nW respectively. The columnar structures exhibited better performances compared to the other structures indicating the columnar structure is good in trapping the light and efficiently collecting the current carrier at the electrode.
Phase and Morphological Studies of LiCo0.3Ni0.3Mn0.3Ti0.1-xSnxO2Cathode Materials
Authors: Elong K , Kamarulzaman N , Chayed N F , Badar N , Abdillih N S S M 
Published: June 2020

AbstractThe substitution of LiCo0.3Ni0.3Mn0.3Ti0.1O2materials with Sn is done to investigate the effect on the phase and morphology. The materials were synthesized via a combustion method. The annealing temperature and time of the precursors was obtained at 700 °C for 24 hours. The crystalline phase and purity of the materials are studied using X-Ray Powder Diffraction (XRPD). All the materials were observed to be pure phase and good cation ordering. Field Emission Scanning Electron Microscope (FESEM) is used to assess the morphology and the crystallites size of the materials. The images showed that the materials consist of polyhedral shaped crystals and well-crystallized particles with smooth surfaces. The % calculated synthesized materials shows close stoichiometry to the % element content from the EDX measurements of the synthesized materials within experimental error.
Dependence of V2O5 Nanorods Properties on Substrate Type Prepared by Simple Hydrothermal Method
Authors: Abd-Alghafour N.M. , Naeem Ghassan Adnan , Mohammad Sabah M. 
Published: June 2020

Abstract

V
2O5 (Vanadium pentoxide) nanorods were prepared onto various substrates by using simple hydrothermal method. The structural characteristics of the V
2O5 nanorods (NRs) have been examined via using XRD diffraction analysis. The effects of the various substrates on the morphological characteristics of V
2O5 NRs were investigated by using field emission scanning electron microscopy (FESEM) technique. The XRD results show that the preferred orientation along (001) plane. Raman spectra indicate that glass substrate has optimum results due to the size and number of the nanorods with lower defects. It can be found from the absorbance of the glass substrate increases compared with the other substrates.
Fabrication and Physical Characterization of Electrospun PVA-ZnO Fibers with Different Deposition Distance
Authors: Hadi Zulkefle Muhammad Al , Mohamad Puad Mohd Izham , Rahman Rohanieza Abdul , Zulkifli Zurita , Herman Sukreen Hana 
Published: June 2020

Abstract
PVA-ZnO composite nanofibers were successfully fabricated by electrospinning method. The effect of the deposition distance (the distance between the needle tip to the substrate) on the fiber diameter was investigated. The distance was varied from 4 cm to 20 cm and it was found out that the fiber diameter decreased as the distance increased. The fiber diameter was in the range of 156 to 251 nm with the finest fiber film was obtained for the distance of 20 cm. The presence of ZnO particles were confirmed with XRD characterization performed in which all PVA-ZnO composite samples displayed typical ZnO XRD peaks 32°, 34° and 36° that corresponded to Miller indices of (100), (002) and (101) of ZnO yet the peaks are more apparent at sample fabricated at the closer distance of 4 cm and 8 cm.
Comparison between standing transparent mirrorless packaging and planar-mounted packaging for GaN-on-GaN LEDs
Authors: Alias E A , Samsudin M E A , Zainal N , Iza M , Alhassan A I , DenBaars S P , Speck J S , Nakamura S 
Published: June 2020

Abstract
This work demonstrates that standing transparent mirrorless LED packaging as an attractive alternative configuration to increase the light extraction of LED on GaN substrate rather than standard planar-mounted packaging. From comparison study, it was found that the external quantum efficiency and the wall-plug efficiency of the standing transparent mirrorless LED is improved by 7% with respect to the planar-packed LED at a standard operating current of 20 A/cm2. The extraction of light of the LED with the standing transparent mirrorless packaging is contributed from all sides of the LED. In contrast, the light extraction for the LED with the planar-mounted packaging is only coming from the top and the sidewalls of the LED as well as having a longer path length for the photon to escape from LED and might increasing the possibility of light absorption in the GaN substrate.
Study of Biomass Management Systems for Agricultural Lands without Fuel and Friendly Environment in West Kalimantan
Authors: Hatta M , Sulakhudin  
Published: June 2020

Abstract
Almost every year in the dry season in West Kalimantan and other regions in Indonesia there are forest and land fires. The prolonged impact of El Nino has resulted in hundreds of thousands of hectares of land being burnt Human health, destruction of plant and animal genetic resources, and huge economic losses. Therefore, it is necessary to open and manage land without burning and environmentally friendly. These methods include the biomanagement system, namely the management of land resources by utilizing biodecomposers and human resource management by engineering institutions. Management of land resources by making a pile of grooves and decomposing biomass. This method in clearing and processing without burning the land but by arranging the trunks, branches and leaves of the remaining felling trees (biomass) into the trenches and then the biomass is decay using decomposers. The land can then be processed and ready to be planted with agricultural commodities such as rice, corn, soybeans, vegetables, and others. Human resource management by engineering institutions such as farmer groups or farmer group combinations, fire care communities and fire prepared communities play an active role in land clearing and land management without burning biomass. The results of the study showed that clearing paddy fields without burning biomass produced 5.7 tons of dry milled unhulled rice ha−1 and 5.8 t ha−1 of dry shelled corn.
High Adsorption Capacity of Activated Carbon from Rubber Seed Shells on Tofu (Soybean Whey) Wastewater
Authors: Irawan C , Yuniar S , Khotimah H , Nata IF , Putra MD 
Published: June 2020

Abstract
Rubber seed shells are the wastes of rubber plants containing active compounds in the form of lignin, so that this part is quite potential to be processed into activated carbon products. Activated carbon is a material that contains amorphous carbon which has an internal surface that has a high adsorption capacity and is often used as an adsorbent. This study aims to determine the effect of the size of the adsorbent, the adsorbent dose and the modified adsorbent from rubber shells on the adsorption process of BOD, COD and TSS in tofu (soybean whey) wastewater. Batch experimental adsorption using magnetic stirrer with a speed of 100 rpm during 6 hours, pHe of 7,5 ± p 0.2 and room temperature showed the optimum dosage adsorbent were 10 g/L, 355 microns particle size, resulting in decrease in the concentration and levels of COD parameters from 8,287 mg/L to 504 mg/L and 93.92% percentage removal; BOD parameters from 1,300 mg/L to 109 mg/L and 91.61% percentage removal; and TSS from 382 mg/L to 95 mg/L and 75.13% percentage removal, respectively. Therefore, the adsorbent from rubber seed shells has a potential to be used as an adsorbent for water and wastewater treatment.
In Vitro and In Silico Characterization of Antimalarial Myristicyl Propanoate
Authors: Mustikasari Kamilia , Eka Harap Joshua , Cahaya Noor 
Published: June 2020

Abstract
Myristicyl propanoate is an ester derived from myristicin, the most aromatic compound of Nutmeg (Myristica fragrans) which has been successfully synthesized. The myristicyl propanoate compound in this study was characterized in terms of its antimalarial activity in vitro and in silico using P. falciparum and molecular docking studies of the Dihydrofolate Reductases-Thymidylate Synthase(DHFR-TS) enzyme, respectively. IC50 value of myristicylpropanoate as 751.96 μg mL−1, while the binding energy value of ΔG myristicyl propanoate ligand with receptors was -5.44 kcal mole−1 and the value of inhibition constant (Ki) was 103509 nM. Hydrogen bonding between the test ligand with the DHFTR-TS enzyme occured in one amino acid residue TRP48, and the π bond was observed in the amino acid residue PHE58. In addition, hydrophobic bonds occured in several amino acid residues such as THR185, TRY57, CYS15, ILE, ILE14, TYR170, ASP54, MET55, ALA16, LEU46. The results of characterization in vitro and in silico of the myristicyl propanoate compounds showed that the compounds are inactive as an antimalarial.
Assessment of land evaluation on erosion reduction with Agroforestry approach around Lake Ngade area
Authors: Shadikin Nurdin Aqshan , Kurniawan Andy , Hadun Ramli 
Published: June 2020

Abstract
Ngade Lake is surrounded by steep cliffs with a very high level of erosion insecurity with a very steep slope > 45% without sloping edges and no outlets. In the upstream region the water catchment area of Ngade Lake is dominated by land use in the form of coconut and nutmeg plantations. This study aims to examine the form of land evaluation strategy to maintain forest function from erosion threat in the area of Ngade Lake water catchment with agroforestry management pattern. The method used in this research was a quantitative descriptive method using field surveys to collect data on the characteristics of the land that is assisted by secondary data from various literature. The collection of land characteristics data was done at each observation point. To collect the primary data used sampling techniques carried out with stratified random sampling method considering accessibility of roads. The results of the study showed that there were several classes of land capacity. Among them were Class II with high potential of land so it can be cultivated for agriculture and settlements. Land capacity Class VI and VII with low-potential land or difficult to be cultivated for agriculture, this land capacity class intended for forestry plants and grazing fields.
The effect of thermostatic test environment on the flexural fatigue performance of hydraulic hose assemblies
Authors: Patil Sandip , Bagade Rutuja , Tamboli Javedkhan 
Published: June 2020

Abstract
The present study investigates the effect of thermostatic subzero (−65°F) and high ambient temperature (+275°F) on the hose performance when tested at a flexing frequency of 70 CPM with an amplitude of ±3.5 inches. The investigation was carried out through hose tear down analysis which includes surface and subsurface deformations at crimp zone, wire braid analysis, over the crimp silicon crack propagation, and microhardness measurements. It was observed that the flexing mechanism of hose when combined with thermostatic subzero and high ambient temperature, it contributes to different deformation mechanisms for the hose and the fitting juncture.