bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular dynamics simulation of surface morphology during homoepitaxial growth of Copper
Authors: El Azrak Hicham , Hassani Abdessamad , Makan Abdelhadi , Eddiai Fouad , Sbiaai Khalid , Hasnaoui Abdellatif
Published: November 2019

In this paper, molecular dynamics (MD) simulation of surface morphology during homoepitaxial growth of Copper was investigated. For this purpose, simulations of Cu deposition on the Cu(111) substrate with an incidence energy of 0.06 eV at 300K were performed using the embedded-atom method (EAM). The grown thin film on Cu(111) reveled a rough surface morphology. During deposition, the important fraction of atoms intended for the upper layers undergone a rising rate of about 40% starting from the 2nd period and continued to increase until 65%, while the lower level reached a permanent rate of only 25% by the 4th period. Otherwise, except at the first layer level, the lower layers are incomplete. This void in the lower layers has favored the growth of the upper layers until a rate of 143% and has accelerated their time appearance. Th incidence energy has favored the filling of lower layers by reducing this surface roughness. However, the temperature effect needs more relaxation time to fill the lower layers.
Modelling of fine fragmentation and fission gas release of UO2 fuel in accident conditions
Authors: Jernkvist Lars O.
Published: November 2019

In reactor accidents that involve rapid overheating of oxide fuel, overpressurization of gas-filled bubbles and pores may lead to rupture of these cavities, fine fragmentation of the fuel material, and burst-type release of the cavity gas. Analytical rupture criteria for various types of cavities exist, but application of these criteria requires that microstructural characteristics of the fuel, such as cavity size, shape and number density, are known together with the gas content of the cavities. In this paper, we integrate rupture criteria for two kinds of cavities with models that calculate the aforementioned parameters in UO2 LWR fuel for a given operating history. The models are intended for implementation in engineering type computer programs for thermal-mechanical analyses of LWR fuel rods. Here, they have been implemented in the FRAPCON and FRAPTRAN programs and validated against experiments that simulate LOCA and RIA conditions. The capabilities and shortcomings of the proposed models are discussed in light of selected results from this validation. Calculated results suggest that the extent of fuel fragmentation and transient fission gas release depends strongly on the pre-accident fuel microstructure and fission gas distribution, but also on rapid changes in the external pressure exerted on the fuel pellets during the accident.
Hole selective materials and device structures of heterojunction solar cells: Recent assessment and future trends
Authors: Wang Zilei , Li Peiyang , Liu Zhaolang , Fan Jiandong , Qian Xiaokang , He Jian , Peng Shanglong , He Deyan , Li Meicheng , Gao Pingqi
Published: November 2019

Research on photovoltaic devices with a high performance-to-cost ratio requires efforts not only on efficiency improvement but also on manufacturing cost reduction. Recently, a record efficiency of 26.6% on crystalline silicon solar cells (SCs) has been achieved by combining the heterojunctions (HJs) with a device structure of interdigitated back contacts. However, the technology that integrates the interdigital p- and n-type amorphous silicon (a-Si:H) layers on the rear surface of the Si substrate is challenging. This issue has motivated researchers to search dopant-free carrier-selective contacts with alternative materials to completely replace doped a-Si:H layers. Transition metal oxides, graphene, and poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), all having high work functions and hole conducting properties, can play the role of hole-selective layers (HSLs). In this review, we focus on the latest advances and the future trends in these HSLs and their applications in silicon HJ SCs. The main issues and challenges encountered are discussed.
Investigation of magnetism and magnetic structure of anti-ThCr2Si2-type Tb2O2Bi by magnetization and neutron diffraction measurements
Authors: Kawasoko Hideyuki , Ohoyama Kenji , Sei Ryosuke , Matsumoto Kota , Oka Daichi , Hoshikawa Akinori , Ishigaki Toru , Fukumura Tomoteru
Published: November 2019

In this study, magnetization and neutron diffraction of anti-ThCr2Si2-type Tb2O2Bi polycrystals were measured at various temperatures. The magnetization cusp at 11.1 K was confirmed to correspond to antiferromagnetic ordering with a propagation vector of [0.5 0.5 0]. In addition, a metamagnetic behavior was observed below 5.0 K. The metamagnetic behavior could be attributed to the incommensurate magnetic structure with an anomaly at 5.0 K.
A magnetic trick for treating neurological disorders
Authors: Bandari Anashe
Published: November 2019

An implantable nanodevice may be the solution to current neuron stimulation techniques, which have limited range and require inconvenient, high-power equipment.
Low sexually transmissible infection knowledge, risk perception and concern about infection among men who have sex with men and transgender women at high risk of infection
Authors: Balán Iván C. , Lopez-Rios Javier , Dolezal Curtis , Rael Christine Tagliaferri , Lentz Cody
Published: November 2019

Background
Amidst an increase in STI rates among men who have sex with men (MSM) and transgender women (TGW), there is little research on STI knowledge, risk perception and concern about infection in these populations. Methods: This mixed-methods study explored these constructs among 60 racially and ethnically diverse MSM and TGW who regularly engage in condomless anal intercourse with multiple partners. Results: Participants had a mean age of 40.63 years. Most (95%) identified as a man and as gay or homosexual (73%); 55% were college graduates. Almost half the respondents reported a prior STI. Participants correctly answered a mean of 55.36% and 76.90% STI and HIV knowledge items respectively. STI knowledge was positively correlated with education and prior HIV tests, and was higher among those with a prior STI. During in-depth interviews, some participants expressed concerns about limited knowledge of STIs and syphilis. Half reported low concern about syphilis infection, due to prior treatment that was perceived as relatively simple, lack of STI infection in the past, erroneous information about transmission routes or simply not thinking about it. Conclusions: Among this high-risk sample who perceived themselves to be at low risk of infection, knowledge was primarily gained through being diagnosed and treated for an STI rather than from acquiring knowledge to prevent STI infection. Participants expressed interest in increasing their STI knowledge and recognised the importance of regular STI testing. Dissemination of targeted information about STI prevention, routinising of STI testing and STI self-testing might contribute to decreasing STI infection rates among this population.
Measurements of the Cross-sections of Produced Short-Lived Nuclei Induced by Neutrons around 14MeV on Isotopes of Tungsten*
Authors: Sun Xiao-Jun , Zhou Feng-Qun , Song Yue-Li , Li Yong , Ji Peng-Fei , Chang Xin-Yi
Published: November 2019

New experimental cross-section data for the 180W(n,2n)179mW, 186W(n,2n)185mW and 186W(n,p)186Ta reactions at the neutron energies of 13.5 and 14.4 MeV are obtained by the activation technique. The neutron beams are produced by means of the 3H(d,n)4He reaction. The gamma activities of the product nuclei are measured by a high-resolution gamma-ray spectrometer with a coaxial high-purity germanium detector. The neutron fluence is determined using the monitor reaction 93Nb(n,2n)92mNb. The results in the current work are discussed and compared with the measurement results found in the literature. It is shown that these higher accuracy experimental cross-section data around the neutron energy of 14 MeV agree with some previous experimental values from the literature within experimental uncertainties.
Molecular Dynamics Study of the Structural Modification of Porous Silica from Low-Energy Recoils*
Authors: Zhang Ji-Hua , Tian Ye , Han Wei , Wang Fang , Li Fu-Quan , Yuan Xiao-Dong , Xiang Xia
Published: November 2019

Molecular dynamics simulations are performed to investigate the effects of low-energy recoils on the microscopic structure of porous silica. Exhibiting a logistic growth with the recoil energy, the displacement probability of Si is shown to be smaller than that of O at the same primary knock-on level. Computations of pair distribution functions and bond angle distributions reveal that this material upon irradiation with energies around the displacement thresholds mainly undergoes structural changes in the medium-range order. In the porous network, while the formation of nonbridging oxygen defects tends to induce shorter Si–O bonds than those formed by bridging oxygen atoms, a remarkable increase of inter-tetrahedral bond angles created by multiple recoils can be observed and associated with the rearrangement of ring statistics.
Experimental Observations Indicating the Topological Nature of the Edge States on HfTe5*
Authors: Liu Rui-Zhe , Huang Xiong , Zhao Ling-Xiao , Liu Li-Min , Yin Jia-Xin , Wu Rui , Chen Gen-Fu , Wang Zi-Qiang , Pan Shuheng H.
Published: November 2019

The topological edge states of two-dimensional topological insulators with large energy gaps furnish ideal conduction channels for dissipationless current transport. Transition metal tellurides XTe5 (X=Zr, Hf) are theoretically predicted to be large-gap two-dimensional topological insulators, and the experimental observations of their bulk insulating gap and in-gap edge states have been reported, but the topological nature of these edge states still remains to be further elucidated. Here, we report our low-temperature scanning tunneling microscopy/spectroscopy study on single crystals of HfTe5. We demonstrate a full energy gap of ∼80 meV near the Fermi level on the surface monolayer of HfTe5 and that such an insulating energy gap gets filled with finite energy states when measured at the monolayer step edges. Remarkably, such states are absent at the edges of a narrow monolayer strip of one-unit-cell in width but persist at both step edges of a unit-cell wide monolayer groove. These experimental observations strongly indicate that the edge states of HfTe5 monolayers are not trivially caused by translational symmetry breaking, instead they are topological in nature protected by the 2D nontrivial bulk properties.
Simulation of precious metals recovery from nickel smelter slag under high-pressure oxidative acid leaching (HPOXAL)
Authors: Cahyari Khamdan , Kholik
Published: November 2019

The nickel smelter slag as a solid waste of pyrometallurgical operations can be harmful to the environment especially against the ground that will be contaminated by hazardous components contained the smelter slag. Nickel smelter slag has the content of valuable metals as the following: Nickel (Ni), Cobalt (Co), Copper (Cu), Iron (Fe) and Zinc (Zn). Those valuable metals were carried out by high-pressure oxidative acid leaching to recover all the valuable metals suitable with the high measures of recovery. High-pressure oxidative acid leaching (HPOXAL) is a suitable process for the nickel smelter slag with the parameters of the leaching process as the following: the particle size about – 150 + 74 μm, sulfuric acid solution with the concentration of 0.3 mol in 1 liter solution, Ratio of Liquid to Solid (L/S) with 7 ml of liquid to 1 gram of solid components, oxygen overpressure at 600 kPa, operating temperature about 180 - 200 °C and the retention time of 80 minutes. The measures recovery of this leaching process for each valuable metal in percent of initial weight such as nickel and cobalt about 97%, copper about 95%, 94% of zinc and all iron can be separated, respectively. At the separation section, LIX 984N as extractant extracts copper from the product (leaching solution) of the reactor, limestone was used to capture iron in the leaching solution, versatic 10 and decyl-4PC were conducted to remove undesirable mineral that was generated from the leaching process, and cyanex 272 extractants to extract such as nickel, cobalt, and zinc, respectively. This simulation used the feed flowrate with 150 tons per day. The results of the precious metals product were generated each the mass rate such as copper, nickel, cobalt, zinc, and iron with 927 kg/day, 2147 kg/day, 875 kg/day, 199 kg/day and 71,000 kg/day, respectively.
Enhancing the yield and quality of Kemiri Sunan crude oil by preliminary extraction of feedstock
Authors: Supriyadi S , Purwanto P P , Hermawan H
Published: November 2019

Biodiesel is an alternative fuel produced by chemical reaction between vegetable oil or animal fat with alcohol and catalyst. The preliminary treatment in extraction of biodiesel feedstock is an important process to obtain maximum yield of crude oil. This study aims to find optimal preliminary treatment on extraction of Kemiri Sunan seed in order to produce crude oil with maximum yield and quality. The research investigated the effects of screw press machine rotation and duration of steaming process. Three levels of duration of steaming used were 30, 60 and 90 minutes. Observations of crude oil yield, moisture content, free fatty acid content, kinematic viscosity, density and color were done. The result suggested that the rotation of screw press machine affected the crude oil yield. The duration of steaming process affected the oil yield, free fatty acid content, kinematic viscosity, density and color. The best oil yield result of 70.3% was obtained from the combination of heating duration of 60’ and screw rotation of 25 RPM.
Effect of Sago Starch Concentrations, Stirring Speeds, and Lemongrass Oil Concentration for Edible Film Production Using Solvent Casting Method
Authors: Santosa H , Djaeni M. , Ratnawati  , Rokhati N , Setiatun A P , Afriyanti
Published: November 2019

Foods such as meat, fillet, fruit and vegetable tend to have short shelf life when it is stored outside without packaging. Recently, edible film and coating become a potential alternative for food packaging. Edible film brings a lot of advantages from environmental aspect because it is easier to be decomposed rather than the synthetic film. Furthermore, edible film might be produced from both natural raw material and waste materials. Edible film from natural raw material gives a rigid structure. Another additive agent must be used to make a better quality product, such as glycerol and lemon grass oil as plasticizer and antimicrobial agent, respectively. These materials are commonly used in edible film production due to its capability for extending the food shelf-life by inhibiting bacterial growth. The objectives of this study are to investigate the effect of starch concentration (3% to 10% w/v), stirring speed (350, 700, 1100 rpm) and lemon grass oil concentration (1%, 5% v/v) on tensile strength, water vapor permeability, and antimicrobial activity. Results show that 4% (w/v) sago starch gives the best edible film mechanical properties and least water transfer. Edible film with 4% (w/v) sago starch, 8 rpm constant stirring, and 5% (v/v) lemongrass oil gives the best result in tensile strength, water vapor permeability and bacterial growth. In addition, variables of starch concentration, stirring speed and lemon grass oil concentration are interrelated to produce the best edible film.
Comparison of the effectiveness electrocoagulation of dye (batik waste water) using iron and zinc as an anodes
Authors: Suhartana S. , Purwanto P. , Darmawan Adi
Published: November 2019

This study aims to obtain dye (batik waste water) treatment by electrocoagulation with optimal results. The performance of electrocoagulation process was carried out in batch reactor. Four variables were taken which thought to greatly influence the electrocoagulation process, such as: distance between electrodes, voltage, acidity (pH) and electrolysis time. In this process, samples of 20 mL were taken out from the batch at 5, 10, 15, 20, 25, 30, 35, 40, 45 dan 50 minutes of contact time. Results obtained show that the most effective removal efficiency could be achieved at alkaline condition. Research that has been done shows that the percentage of wastewater treatment results is strongly influenced by the four variable changes. The study demonstrated that the lowest degradation efficiency occours at acid pH, while an increase temperature has only a slight effect on the electrocoagulation process. The maximum results from the electrocoagulation processes was obtained, with determine by measurement of chemical oxygen demand (COD). The results showed that, iron is better used as an anode than zinc. The effectiveness electrocoagulation reached optimal at 96.54% (at Fe anode) and 81.65% (at Zn anode), at alkaline condition (pH > 9), electrolysis time of 30 minutes, electrode distance of 1 cm and temperature at 70°C.
The Ultrasound-Assisted Extraction of Rice Bran Oil with n-Hexane as a Solvent
Authors: Djaeni M , Listyadevi Y L
Published: November 2019

Rice bran oil (RBO) is one of edible oil which widely used in chemical, pharmaceutical, and food industries due to its unique properties and high medicinal value. RBO obtained by ultrasound-assisted extraction using n-hexane as solvent. This present study aims to determine the ideal bran to solvent ratio to obtain the highest extraction yield using optimal temperature. Rice bran which 90% passable through a sieve with 700 μm opening, was used for the extraction process. The extraction process was done at various temperature (40, 50, 60°C), and various bran to solvent ratio (1:5, 1:10, 1:15 w/v) for 2 hours at 40 kW. The highest yield ultrasound-assisted extraction was 20.35% with ideal bran to solvent ratio 1:5 w/v using 60°C. The RBO yield increased with increasing bran to solvent ratio and temperature at the isobaric condition.
Fructose Syrup Production from Tapioca Solid Waste (Onggok) By Using Enzymatic Hydrolysis in Various pH And Isomerization Process
Authors: Yulistiani F , Saripudin  , Maulani L , Ramdhayani W S , Wibisono W , Permanasari A R
Published: November 2019

Tapioca solid waste (onggok) from cassava contains high carbohydrate (about 76%). The carbohydrate contains amylose and amylopectin which are the raw material of glucose syrup. Fructose is isomer of glucose which has higher dextrose equivalent. It is potential to produce fructose syrup from onggok by using enzymatic hydrolysis and through isomerization process. This research aimed to produce fructose syrup from cassava solid waste in various pH of enzymatic hydrolysis (liquefaction and saccharification) and isomerizing the glucose to be fructose syrup. Onggok in particle size 63 μm was dissolved in distilled water to make substrate concentration of 25%, 30%, and 35% (w/v). Each of the substrate concentration was hydrolyzed with α-amylase as the liquefaction process and was continued with addition of glucoamylase in saccharification process. The hydrolysis process was set in various pH, 5.5, 6, and 6.5. In liquefaction, the substrate suspension was added by 0.067% α-amylase (v/v) with heating temperature 90°C for 60 min. Then, it was continued for saccharification by adding glucoamylase in the same ratio with α-amylase for 120 minutes in 55°C. During the hydrolysis process, the sample was taken from each solution in 10 minutes to analyze the reducing sugar concentration by DNS reagent. After the hydrolysis process, the suspension was filtered and evaporated to reduce the water content. Filtrate with the highest reducing sugar concentration was isomerized by adding 1% of glucose isomerase and heated in 60°C, pH 8.2 for 43 hours. The fructose syrup concentration was then analyzed by resorcinol reagent and the result was 229.3 g/l, yield 9.298%, and conversion 24.587%.
Betaine-based deep eutectic solvents with diol, acid and amine hydrogen bond donors for carbon dioxide absorption
Authors: Mulia K , Krisanti E , Nasruddin  , Libriandy E
Published: November 2019

Deep eutectic solvents (DESs) are known as alternative green solvents due to their ease of synthesis, availability, biodegradability and negligible volatility. DESs consisted of betaine as the hydrogen bond acceptor with 1,2-propanediol, levulinic acid and methyl diethanolamine (MDEA) as the hydrogen bond donors, were prepared in 1:3 and 1:6 molar ratios. The carbon dioxide solubilities in these DESs were determined using a volumetric apparatus at 313.15 K and 6 bar. The results show that CO2 solubilities in betaine-based DESs are higher than the reported CO2 solubilities in choline chloride-based DESs, for DESs having the same hydrogen bonding donor and an identical or similar composition. The viscosity and polarity of hydrogen bond donors affected the ability of deep eutectic solvent to absorb carbon dioxide. The betaine-MDEA deep eutectic solvent, with molar ratio of 1:6, has the highest absorption capacity of 0.0814 mol CO2/mol DES, measured at 313.15 K and 6 bar.
The Reduction of COD Levels in Domestic Waste Water Using Combination of Activated Sludge Methode – Activated Carbon Continously
Authors: Mukhtar G. , Retno I , M T. , Fajar N , Satria A
Published: November 2019

Domestic waste water produced from Pujasera Politeknik Negeri Bandung has a relatively high organic compound. It can cause environmental pollution, so waste water treatment is required to reduce the concentration of organic compounds. The purpose of this study is to determine the efficiency of processing organic compounds in domestic wastewater using active sludge in combination with Activated carbon. The acclimation process is carried out in batches, while the waste water feed is continuously fed by varying the retention time and activated carbon concentration. Variation of retention time of 12, 18, 24 hours and variation of activated carbon concentration 50, 100, 150 ppm. The parameters used in aerobic wastewater treatment are COD, pH, and MLSS measurements. Based on the results of data analysis showed that the percentage decrease of COD from 861 mg / L to 160 mg / L with a pH range of 6.5 to 7 and MLSS averaged 2951 mg / L. The optimum retention time 24 hours with efficiency of COD effluent reduction without activated carbon was 74.91%. With the same operating conditions, at 24 hours of retention time using a combination of activated sludge - activated carbon of 150 ppm, the efficiency of COD effluent reduction was 89.97%.
Recycling and processing of solid waste into products of the cosmetic packaging industry
Authors: Purwanto P. , Permana-Citra A.D.
Published: November 2019

The waste generation of the plastic packaging industry for the cosmetic product is consisting of the hazardous and non-hazardous waste. The non-hazardous waste of cosmetic product includes product reject, plastic bags, cardboard, and paper. The content of hazardous waste of the cosmetic product is the part such as chemical packaging drum, paint sludge, and wastewater treatment sludge. On the other hand, there is a chance of the waste management that can be started from the segregation of both hazardous and non-hazardous waste, recycling of non-hazardous waste and utilization of waste into products by third parties. That is because the dangerous waste that is carried out according to the waste regulation can be used as a useful product to provide economic and environmental benefits. The research examines various opportunities to use waste as raw material and also to be processed into products. The study steps consist of identification, assessment, techno-economic analysis, and implementation approaches. The study results show that the hazardous solid waste can be used as fuel, filling materials for paving blocks, and ceramic raw materials. The utilization as raw material for paving blocks shows the most significant opportunity for economic and has environmental benefits.
Drying rate and efficiency energy analysis of paddy drying using dehumidification with zeolite
Authors: Djaeni M , Irfandy F , Utari F D
Published: November 2019

Paddy must be dried to prolong the storage life and maintain the quality. There was some researches about paddy drying system: bin dryer. The dehumidification process giving advantages in high efficiency energy, but it is taking the heat for regeneration. Based on the literature study, it is hard to find the literature about drying efficiency analysis during the drying of paddy. This research aims to observe the effect of drying temperatures and addition of zeolite in drying system. Paddy grains were dried from initial moisture content 22% (wet basis) under different temperature 40, 50, and 60°C for 90 minutes drying. Zeolite was used as adsorbent to decrease the relative humidity of air dryer. Results showed that use of zeolite lowering the air humidity and increasing driving force for drying. These made the drying rate increased. The higher drying temperature can also increase drying rate. Energy efficiency decrease during the drying process. Also, addition of zeolite in drying process affected the drying efficiency.
Effect of pH on Depolymerization of κ-Carrageenan by Ultrasound, Ozone and Their Combination
Authors: Prasetyaningrum A , Jos B , Dharmawan Y , Ratnawati R , Riyandita S , Scesario R
Published: November 2019

κ-carrageenan is sulphated linear polysaccharides of D-galactose and 3,6-anhydro-D-galactose extracted from certain red seaweeds of the Rhodophyceae class. They have been extensively used in the food and pharmaceutical industry. However, the use of the κ-carrageenan in the biomedical field is inhibited by its easy to form a gel and a high viscosity. Therefore, it is necessary to production of low molecular weight of carrageenan using depolymerization methods. The objective of this research is to study the effect of pH to reduced the molecular weight of κ-carrageenan with ozonation (O3), ultrasonication (US) and the combination of O3 and US (O3–US) methods. The experimental result shows that the O3–US treatment can decrease the molecular weight of κ-carrageenan until 80.77% at pH 7 during 20 minutes of treatment. Depolymerization of κ-carrageenan at pH 3 has the highest percentage compared to pH 7 and pH 10. The percentage depolymerization of κ-carrageenan using O3–US method at pH 3,7 and 10 are 94.22%; 80.77% and 75.85%, respectively.
The Effect of pH and Current Density on Electrocoagulation Process for Degradation of Chromium (VI) in Plating Industrial Wastewater
Authors: Prasetyaningrum A , Jos B , Dharmawan Y , Praptyana I R
Published: November 2019

The heavy metal of chromium is one of the most common pollutants of the plating industrial wastewater. Cr (VI) is one of toxic metal that cause serious threat to human health and the environment due to its cumulative effects and non-degradability. Among the technologies for removing these pollutants, electrocoagulation can be considered as an effective method. This method has some advantages such as fewer amounts of produced sludge and high efficiency in removal of pollutants. This research intended to study effect initial pH and current density on the degree of Cr (VI) removal from wastewater of plating industry by using the electrocoagulation method. The process is done at pH values of (3-9) at current density of 0.42, 0.63, 0.83, 1.04, and 1.25 mA/cm2. Synthetic chromium wastewater was prepared at the initial concentration of 50 mg L−1 during 30 minutes of electrocoagulation process. After electrocoagulation treatment, concentration of Cr (VI) analysed by UV-Vis spectrophotometer. The result revealed that the best removal was achieved at pH 7 and current density of 1.25mA/cm2.
The Effects of Rice Straw Weight Fraction and Particle Size on Thermal Conductivity and Mechanical Properties of Polypropylene Composite
Authors: Wahyuni N L E , Soeswanto B , Aulia H , Fadhilah R.A
Published: November 2019

Polypropylene is a widely used material for various types of equipment. As a recyclable thermoplastic polymer, polypropylene composite provides an attractive quality of thermal insulation due to its heat-retaining property. The use of rice straw for filler in thermal insulating material is based on its low thermal conductivity, renewable material, and low cost production techniques. The composite were manufactured by melt-mixing of neat polypropylene and filler of various weight fractions, pellet formation, followed by reprocessing with injection molding. The current work focused on determining the effect of filler’s weight fraction, particle size and pretreatment on the thermal conductivity and tensile strength of the composite. The result showed that an increase of filler’s weight fraction up to 30% decreased the composite’s thermal conductivity and tensile strength gradually. Composite of fine particles filler (325 mesh) gave a lower thermal conductivity and higher tensile strength than that of coarse particle (18-35 mesh). Composite with the lowest thermal conductivity of 1.39 W/mK was obtained at 30 w.% filler content and fine particles filler (325 mesh). Improvement on composite properties achieved by acetylated rice straw which enable to reduce straw’s hydophylicity and enhance adhesion between matrix and filler.
A Comparative Study on FeCrAl Alloy and NiCrSi Alloy Materials as Heating Element at Low Energy Oven
Authors: Syakur Abdul , Vingtsabta Veinard , Swastawati Fronthea , Wijayanti Ima
Published: November 2019

In this era we need lower energy consumption in electronic devices, example on oven. There is a heating element inside the oven. The heating element should produce high temperature with low energy consumption. Heating element in this research use FeCrAl alloy and NiCrSi alloy. FeCrAl alloy or Kanthal A-1 wire consists of 20% chromium, aluminum and ferum. NiCrSi or Nichrome 80 consist of 80% nickel, 19,5% chromium and 1,45 silicon. The reason using these both wire, because both of wire have high resistivity and produce high temperature. In this research using FeCrAl alloy and NiCrSi alloy 0,8 mm with variations in coil diameter 10 mm. Both of wire applied in oven 40 cm x 40 cm x 50 cm to produce 40 °C . From FeCrAl alloy dan NiCrSi alloy to produce 40 °C with same voltage input, NiCrSi 0,8 mm with 10 mm diameter produced power 170 Watt took 4.4 minutes to reach 40 °C and the energy consumption is 12,5 Wh. With same diameter FeCrAl produced power 210 W took 4,4 minutes to reach 40 °C and energy consumption is 15,4 Wh. From the data results show that the NiCrSi alloy has lower resistance value than the FeCrAl Alloy. It can be concluded that NiCrSi alloy diameter of 0.8 mm with a winding diameter of 10 mm consumes low energy in generating heat.
Optimization of aqueous extraction of blue dye from butterfly pea flower
Authors: Baskaran A , Mudalib S K A , Izirwan I
Published: November 2019

Dyes are widely used in industries such as textiles, leather, paper, and plastics to colour the final products. People use natural sources such as stem, bark, leaves, roots and flowers to get different colours for dyeing purposes. In addition, natural colorants such as anthocyanins are known for their possible health benefits as dietary antioxidants. The objectives of this study are to extract the blue dye from the butterfly pea flower using maceration method and to determine the optimum condition by response surface methodology. The flowers were dried, grinded and went through the maceration method for the extraction process. Response surface models were developed correlating the extraction yield with three parameters namely residence time, temperature and solid to liquid ratio. The result from this experiment was optimized using response surface methodology to obtain the optimum condition at temperature 54 °C, extraction time 74 minutes and solid-to-liquid ratio of 1:37 to give extraction yield of 45.51 %.
Comparison of extraction sequence on yield and physico-chemical characteristic of chitosan from shrimp shell waste
Authors: William W , Wid N
Published: November 2019

The focus of this study was to compare the yield and characteristics of chitosan produced from different sequences of treatment for deproteination, demineralization and deacetylation. In Process 1, deproteination occurred in the first step followed by demineralization and deacetylation. While Process 2 was started with demineralization step and followed by deproteination and deacetylation. The results show that the percentage yield of chitosan was slightly higher when Process 2 was adopted with 22.22 %. However, the process produced chitosan with lower degree of deacetylation and solubility with high ash content, which were 76.47 %, 37.79 % and 2.67 %, respectively. While, when Process 1 was carried out, the degree of deacetylation of chitosan, solubility and ash content were improved to 91.26 %, 100 % and 0.38 %, respectively, with lower yield of 19.01 %. Therefore, this study suggests the extraction process should be performed by carrying out deproteination step before demineralization and deacetylation (Process 1) to produce a good quality of chitosan.
Growth and phenolic constituents production of roselle (Hibiscus sabdariffa var. UKMR-2) in response to soil media
Authors: Aishah M A Siti , Rohana T , Masni M A , Jalifah L
Published: November 2019

Plant phenolic content frequently varies in response to the changes in the environment and genetic factors. However, studies on the response of phenolic contents when cultivating under different soil media is still scarce. The present study investigates the phenolic constituents’ production and growth quality of Hibiscus sabdariffa var. UKMR-2 in response to different soil media formulation ratio of topsoil, organic matter and sand. The cultivation using two different media; Soil Media 1 (SM1) with 2:1:1 v/v and Soil Media 2 (SM2) with 2:1:2 v/v. The UKMR-2 calyx extract was analysed for total phenolic (TPC), total anthocyanin (TAC), antioxidant activity (in IC50) and evaluated based on HPLC-PDA. The result showed the mean value for SM1 and SM2 treatment, respectively: TPC was 2.54±0.34 and 2.47±0.34 mg GAE / g DW; TAC was 8.06±1.11 and 7.86±1.99 mg cyanidin-3-glucoside equivalents / g DW; IC50 value was 0.146±0.018 and 0.210±0.063 mg/mL. The HPLC-PDA showed the presence of delphinidin-3-O-sambubioside and cyanidin-3-O-sambubioside. The cultivation using SM1 tends to increase plant growth, calyx yields, phenolic constituents’ production and antioxidant activity. However, the different soil media ratio has no significant influence on the growth and phenolic constituent production (p > 0.05). In general, SM1 (2:1:1 v/v) soil media ratio may produce better growth, higher percentage yield and phenolic constituents’ for UKMR-2 cultivation.
Effects of chitosan and ascorbic acid coating on the chilled tilapia fish (Oreochromis niloticus) fillet
Authors: Lee J S , Jahurul M H A , Pua V C , Shapawi R , Chan P T
Published: November 2019

The effect of chitosan-based coating containing ascorbic acid (AA) for shelf-life extension of chilled (4 °C) tilapia fish fillet was evaluated over a 15-day duration of storage. A 3 X 3 Factorial Design comprising three concentrations of ascorbic acid (0, 2.5 and 5% w/v) and three concentrations of chitosan (1, 1.5 and 2% w/v) were used. The fish fillets were analyzed for aerobic plate count, lipid peroxidation, aw and pH changes throughout the duration of storage. The shelf-life of coated fillets (1.5 and 2%) was lengthened up to 15 days as compared to uncoated one (less than 6 days). The lipid oxidation of fillet with chitosan and AA (2C-5AA) was reported to be four times lower than that of the uncoated sample. The pH and awof fish fillet coated with chitosan were lower than that of uncoated sample. The addition of ascorbic acid in chitosan coating further improved the oxidation inhibition by giving a lowered pH and aw changes for the duration of the storage. In conclusion, 2% chitosan coating added with 5% AA was the most effective coating to enhance the shelf life of chilled tilapia fish fillet.
Body Size and Morphological Characteristics in sex determination of Humphead Wrasse Cheilinus undulatus in captivity
Authors: Tan B L , Ching F F , Senoo S
Published: November 2019

This study was aimed to identify the sex of humphead wrasse, Cheilinus undulatus kept in captivity based on body sizes and morphological characteristics. There were 65 tails of C. undulatus broodstocks reared in the captivity throughout six months of research period and fed daily with enrich prey fish (Sardinella sp.). Growth parameters and morphological characteristics such as presence of eyeline, hump on head and genital papillae, of the C. undulatus were carried out. These findings revealed in captivity, female of C. undulatus (n=13) attained an average body weight of 2.78 kg and total length 47.10 cm meanwhile male of C. undulatus attained larger body weight (14.62 kg) and total length exceeding size of female (89.30 cm). C. undulatus performed an isometric growth pattern (b = 2.9487) with condition factor of above 0.2. Morphologically, female was identified with the noticeable alleviation of the hump on its head and the visibility of eyeline behind its eyes which was not seen in male. This study concluded sex of C. undulatus in captivity is differentiated through body size and morphological features and take longer time in sex transition, thus balanced sex ratio for good broodstock management can be controlled to develop appropriate breeding protocol.
Applicability of Palm Oil Fuel Ash in Interlocking Compressed Earth Brick – A Preliminary Assessment
Authors: Tonduba Y W , Mirasa A K , Asrah H
Published: November 2019

This paper presents the preliminary assessment on the applicability of palm oil fuel ash (POFA) as one of the materials used to produce interlocking compressed earth brick (ICEB). Ultrafine size POFA was used to replace the main ingredient for ICEB production which is the clay soil. The percentages of replacement were limited to 0%, 10%, 20%, 30%, 40%, 50%, and 60% by weight of the total clay soil material. The main purpose of conducting the experiment is to identify the most desirable mix through compressive strength test. Result showed that, at the curing age of 28 days, the compressive strength of mixture that substituted with 30%–60% of ultrafine POFA achieved higher strength than the control mixture. Meanwhile, the highest compressive strength was obtained by batch series CP50 (50% clay soil + 50% ultrafine POFA). The experimental studies specified that ultrafine POFA has significant possibilities for application in manufacturing ICEB.
Acetylcholinesterase from the brain of Monopterus albus as detection of metal ions
Authors: Khalidi S A M , Sabullah M K , Sani S A , Ahmad S A , Shukor M Y , Jaafar ’I N M , Gunasekaran B
Published: November 2019

Overwhelming amount of heavy metals discharged due to industrialization is a serious global concern. Thus, an investigation was done on acetylcholinesterase (AChE) from Asian swamp eel,Monopterus albus, as an alternative biosensor to detect various metal ions. AChE from the brain ofM. albuswas purified through ammonium sulphate precipitation and procainamide affinity chromatography. Enzyme recovery was obtained at 38.73% with the specific activity of 1847 U μg−1. The Michaelis constant (Km) value and maximal velocity (Vmax) were determined at 8.910 mM and 29.44 μmol min−1mg−1, respectively for acetylthiocholine iodide (ATC). Based on effective coefficient ratio, AChE fromM. albusbrain showed higher affinity to ATC compared to butyrylthiocholine iodide (BTC) and propionylthiocholine iodide (PTC) at the value of 3.304, 1.515, 2.965 Vmax.Km−1respectively. Optimum activity of AChE was obtained at 40°C and incubated in 0.1M Tris HCl buffer pH 9.0. Inhibition study performed on 10 heavy metals resulted in this descending order of inhibition mercury<chromium<zinc<copper<arsenic<silver<cobalt<cadmium<lead<nickel, with mercury and chromium showing more than 50% inhibition at 10 ppm. Data from this study can be further utilized to develop a cheaper, easier, and faster heavy metal detection method as compared to conventional methods available.
Assessment of Monopterus albus liver as a source of Cholinesterase for the detection of heavy metals
Authors: Sabullah Mohd Khalizan , Khalidi Siti Aishah Muhammad , Wahid Dg. Nooralizan Abd. , Sani Suraya Abd. , Abdulla Rahmath , Faik Ainol Azifa Mohd , Gansau Jualang Azlan , Ahmad Siti Aqlima , Shukor Mohd Yunus
Published: November 2019

Heavy metals pollution has now become a serious environmental problem worldwide especially in Malaysia River. As a precaution, continuous environmental monitoring is needed to minimize heavy metal to the ecosystem. Inhibitive enzyme assay based on enzyme including cholinesterase has been introduced as a rapid, cheap and reliable method to assess the level of contamination in the river. In this study, the Asian swamp eel,Monopterus albus, was selected and determined of the sensitivity level towards heavy metals. The liver of M. albus was extracted and purified using ion exchange chromatography of which DEAE sepharose as the matrix of the column. Based on the Ellman assay, cholinesterase was obtained at 4.86 purification fold with the percentage recovery of 30.32 %. The enzyme works optimally at pH 9 (0.1 M Tris-HCl buffer) and 25 °C, while BTC; 369×103U.mg−1was selected as the preferable substrate which shows highest catalytic efficiencies compared to ATC and BTC at 1457 × 103, 1220 × 103and 488 × 103Vmax.Km−1, respectively, Cholinesterase was tested with eight metal ions at the concentration of 5 ppm and the ascending order of inhibition is as followed; arsenic = chromium ⩽ plumbum ⩽ copper ⩽ argentum = nickel < mercury. From this study, the ability of cholinesterase partially purified from the liver tissue ofM. albushas the potential to be an assay for heavy metals.
Public Perception to Littering in Greenspaces: A Case Study in Bintulu, Sarawak, Malaysia
Authors: Abdul Aziz Nor Akmar , Lukhman Arief Aiman , Chubo John Keen , Daud Dayangku Shazana Rawaida Awangku
Published: November 2019

Greenspaces are central to the success of cities. However, what is normally found while walking in local parks or greenspaces are empty cans, bottles, food wrappers and other litters that ruin the aesthetic beauty of the site. Increase in the number of visitors visiting parks in Malaysia has resulted in a growing littering problem. Some parks even received numerous complaints regarding litter. In order to understand the problem of littering in parks, a study was conducted with the objective of identifying factors influencing peoples’ littering behaviour in Pantai Temasya Bintulu, Sarawak, Malaysia. A total of 178 set of questionnaires were distributed to visitors at Pantai Temasya Bintulu, Sarawak, which is a popular recreational park in Bintulu. Data collected was encoded into the Statistical Package for Social Science (SPSS) and analysed accordingly. The study found more male (61.8%) than female (38.2%) respondents have done littering in the past. While more Chinese (73.1%) respondents admitted to littering than any other races. With regards to marital status, singles (64.2%) and those without children (64.4%) top the list for littering. Respondents of the age group of 17 to 25-year-old (70.6%) recorded a high percentage for littering as compared to other age groups. Respondents with only a primary school (66.7%) education have a higher tendency to litter. Besides, jobless adults and students also dominated the chart for littering for the occupation profile. Parallel with that, the income group which those without any source of income (65.3%) was the highest to admit to littering. The study identified attitude to be the highest factor influencing littering among visitors with nearly 65% respondents agreeing to it. Meanwhile, beverage containers such as aluminium cans, glass and plastic bottles were found to be the type of litter most frequently found in Pantai Temasya Bintulu. Studies on public perception towards littering are essential for administrative and strategic planning of litter control. In the case of Pantai Temasya Bintulu, early education and awareness campaigns are seen to be the best approach to instil good attitudes among the visitors.
Multi-temporal Land-Cover Classification of Kinabalu Eco-Linc Site and the Protected Park Areas
Authors: Miuse C F , Kamlun K U
Published: November 2019

The Crocker Range Park and Kinabalu Park are Sabah’s largest terrestrial parks physically separated by approximately 10 km. Both parks are involved in a set up plan of ecological linkages to connect and further strengthen the biodiversity conservation efforts in the State of Sabah. The part of ecological linkages project is known as Kinabalu Eco-Linc (Kinabalu Ecological Linkage). This study is designed to monitor the land use change of the area between year 1991 - 2018 using Landsat imagery. Maximum likelihood classifier was used to create the land cover change map of both protected areas. Seven land cover type were identified in the area which comprises of primary forest, secondary forest, shrubland/grassland, barren land, agriculture, plantation, and river. The result illustrated a drastic declined of primary forest and increased secondary forest and agricultural over the period of 28-years assessed. The spatial changes that occur throughout the period within state park and KEL area is drives by natural and anthropogenic activities. To support the increase in local population and their demand, the natural environment underwent changes for their welfare improvement. It is concluded that, monitoring protected area using remote sensing technique provide useful spatiotemporal data to locate key areas that are vulnerable to threat and can be utilized for better management of both protected areas and human use resources in adjacent area.
Tailoring Structural and Optical Properties of Composite Glass with Rice Husk Fibre (RHF) as Additive Materials
Authors: Piara S N H , Awang A , Dayou J
Published: November 2019

This paper reports the effect of additional of rice husk fibre (RHF) with various sizes ranging from 63μm, 125μm and 250μm on the structural and optical properties of glasses. A series of glass with composition of 69.50TeO2 – 20ZnO – 10Na2O – 0.50Er2O3 – (x)0.2%RHF (x = 63μm, 125μm, 250μm) are synthesized by using melt-quenching technique. XRD pattern shows the nonexistence of sharp peak reflect the amorphous nature of glass without RHF content. However, an addition of RHF in glass matrix shows the appearance of sharp peaks signifies the contribution of cristobalite due to the incorporation of rice husk. SEM image of glass containing 125μm RHF illustrates the glass surface morphology. The respective EDX spectra of glass containing 125μm RHF verify the elemental traces of carbon, oxygen, sodium, zinc, tellurium, aluminium, silicon, copper, calcium and erbium. The variation in absorption coefficient of glass with additional of different sizes of RHF are observed due to the lowering value of α.