bluuebunny/crossref_metadata_2025 huggingface dataset:
Low density polyethylene/poly(butylene adipate-co-terephthalate) films: Effect of a compatibilizer on morphology and properties
Authors: Hemsri S , Puttiwanit K , Saeaung K , Satung P
Published: December 2020

Low density polyethylene (LDPE)/poly(butylene)adipate-co-terephthalate (PBAT) blend films were fabricated using a cast film extruder with different content of PBAT (0,10, 20 and 30 wt%). Polyethylene-graft-maleic anhydride (PE-g-MA) was used as a compatibilizer for the LDPE/PBAT blends. Morphology, mechanical properties, thermal properties, water vapour and oxygen permeability properties of the LDPE/PBAT films with and without adding the compatibilizer were investigated. Scanning electron microscopic (SEM) results revealed that the LDPE/PBAT/PE-g-MA films showed better compatibility and homogeneity between LDPE matrix and PBAT phase. Young’s modulus and tensile strength of the LDPE/PBAT/PE-g-MA films were higher than those of the LDPE/PBAT films. The PBAT content and incorporating PE-g-MA did not affect on melting temperature (Tm) of the LDPE/PBAT blends. On the other hand, melting enthalpies (ΔHm) of the polymer blends decrease as increase in PBAT concentration and at same content of the PBAT, the melting enthalpies (ΔHm) of the LDPE/PBAT/PE-g-MA films were higher than those of LDPE/PBAT films. Water vapor transmission rate (WVTR) of the blend films increased but oxygen permeability (OP) decreased when the PBAT content increased. Compared with uncompatibilized LDPE/PBAT films at the same PBAT loading, the compatibilized LDPE/PBAT films provided a lower water vapor barrier whereas the LDPE/PBAT/PE-g-MA films showed a better oxygen barrier.
A Wideband Printed Monopole Antenna with a Co-Planar Waveguide Feeding
Authors: Surin Chanapon , Srimoon Duangarthit , Mearnchu Jhirat
Published: December 2020

A wideband printed monopole antenna with a co-planar waveguide feeding is presented. This antenna provides a frequency range of 1.7 – 6.0 GHz. It is a flat conductor on FR4 printed circuit board. The shape of ground and pole are rectangle that the 2 corners near the feeding point are 25 degree chamfered, symmetrically. The ground is etched to form a co-planar waveguide for feeding. For this work, the antenna is simulated by using computer program before fabricating a prototype. The antenna provides an omni-directional radiation same as donut shape at the low frequency of the operating band. The radiation pattern is change when the frequency is shift to high but still omni-direction. The bandwidth of the antenna is 112% between 1.7 GHz and 6.0 GHz with the reflection coefficient less than -10 dB across the band. Gains of the antenna are 2.3, 4.9, and 3.4 dBi at the frequencies of 1.8, 3.8, and 5.8 GHz, respectively. They are the 3 points of low-, central- and high-frequency of the operating band. The size of the antenna is 70.0 × 40.0 mm2. Advantages of the antenna are wideband, low profile structure, light weight, and can be fabricated by FR4 make it low-cost.
Kinetics studies and thermodynamics of oil extraction from immobilized microalgae cells of Chlorella vulgaris: The effect of the different matrix system
Authors: Ramesh N , Mat Yasin N H , Mohd Arshad Z I
Published: December 2020

This research article discusses the effect of different chemical matrices used for the immobilization of microalgae cells of Chlorella vulgaris on oil extraction in terms of oil yield, kinetic values, and thermodynamic values. The experimental procedures began with microalgae cultivation, immobilization of microalgae, microalgae harvesting, and oil extraction. For the immobilization method, the matrix systems involved were sodium alginate (SA), calcium alginate (CA), and sodium carboxymethyl cellulose (CMC). For the oil extraction process, heptane was used as an only solvent at different temperature and extraction time. The amount of oil extracted from the SA system was found to be the highest compared to other chemical matrix systems, which is 25.11 % at 348 K. The values of the reaction rate constants were found to increase with temperature and extraction time for SA and the activation energy was determined to be 39.6636 kJ/mol, which is lowest among the systems. Moreover, with the enthalpy value of 0.115 kJ/mol, the extraction process using the SA system is endothermic and was found to be industrially more feasible process compared to other matrix systems. Hence, the results proved that the immobilization of microalgae for biodiesel production is considerable for the future biofuel industry.
Extraction of pectin from banana (Musa acuminata x balbisiana) peel waste flour using crude enzymes secreted by Aspergillus niger
Authors: Kumoro A C , Mariana S , Maurice T H , Hidayat J P , Ratnawati R , Retnowati D S
Published: December 2020

Intensive cultivation has maintained annual banana production in Indonesia at about 7 million tons since 2015. Banana fruits bear about 35 - 40% weight of peel waste, which contains 20.28 g pectin/100 g the dry matter. The peel waste may trigger serious environmental problems. This study aimed to investigate the effect of substrate concentrations and time on the pectin yield extraction from banana peel waste flour using crude pectinase secreted by Aspergillus niger. Crude pectinases were prepared through batch fermentation of banana peel flour using A. niger. The enzymes were used to hydrolyze banana peel waste flour at various substrate concentrations and time at 323 K. The results indicate that the increase of both extraction parameters leads to increase the pectin yield to some extent and then level off. However, further increase of both extraction parameters cause inhibition by galacturonic acid. The highest pectin yield (10.8% weight) was achieved at 323 K and 0.067g/mL substrate concentration for 120 minutes. Applications of this result are expected to increase the economic value of banana peel waste. However, further study in the effect of other extraction parameters such as temperature, enzyme loading, pH, flour size and pectin purification are required.
Immunological properties of the chicken egg yolk (IgY) antibodies against Vietnamese cobra Naja Naja venom
Authors: Nguyen V T , Vu T T H , Hoang V T , Nguyen T V , Lam T D , Nguyen K C , Than V T , Le V P
Published: December 2020

Venomous snake bite is common poisonous accident and important medical problem around the world. The snake anti-venom is only type-specific protection to each venom type that was used to immunize. In this study, the chicken egg yolk (IgY) antibodies against the Vietnamese cobra Naja Naja venom was developed and evaluated in in-vitro (ELISA and SDS-PAGE) and in-vivo (hen and mice immunization). In particularly, the LD50 of the Vietnamese cobra Naja Naja venom was determined at 1.46 g kg−1 body weight of the Swiss mice. The ISA Brown layers of 16 to 18-week-old were immunized intramuscularly with the Vietnamese cobra Naja Naja venom at 0.5 mg kg−1 body weight of the layers. The specific anti-venom antibodies were presented in both serum and egg yolk at 14 days, reached to highest antibody titer at 49 to 56 days and lasted up to 111 days post-immunization. The IgY antibodies purified from the egg yolk revealed potential neutralization and protection of Vero cells and Swiss mice from toxicity of the Vietnamese cobra Naja Naja venom. To the best of our knowledge, this study result is the first cobra snake anti-venom developed in laying hens against the Vietnamese cobra Naja Naja venom. Further study is needed to whether this specific IgY anti-venom antibodies can be used as an antibody therapy for treatment of venomous snake bites in the future.
Evaluation of polyphenol content and antioxidant activities of Dill leaves extract Anethum graveolens L.
Authors: Nguyen V T , Nguyen N Q , An T N T , Van N T , Anh N H T
Published: December 2020

Natural plants are an excellent source of materials for the extraction and application of bioactive compounds. Two extracts from the Dill leaves (Anethum graveolens L.), including the ethanol leaves extract (ELE) and the extract of the aqueous leaves (ALE), were applied to determine the polyphenol, flavonoid content and antioxidant activity of this plant. This plant preliminary phytochemical screening was found to have positive reactions for alkaloids, flavonoids, triterpenoids, saponins, tannins, coumarins and reducing assays. The findings of the quantitative determination revealed that the TPC of ELE and ALE was 69.76 ± 1.57 and 47.71 ± 1.44 mgGAE/g dry extract, respectively. In contrast, TFC was 49.10 ± 1.30 and 19.39 ± 0.61 mgQE/g dry extract, respectively. ELE exhibited the highest DPPH (IC50 = 149.39 ± 5.74 µg/ml) and ABTS (IC50 = 87.43 ± 3.07 µg/ml) radical scavenging activity. These results show that Dill can be used in culinary applications with the ability to minimize oxidative stress.
Effects of microwave extraction conditions on polyphenol content and antioxidant activity of pomelo extract (Citrus maxima (Burm.)Merr.)
Authors: Nguyen N H K , Duong H N , Long H , Nhi T T Y , Phat D T
Published: December 2020

The albedo, white peel of pomelo Citrus maxima (Burm.)Merr., is by-product of food processing, and has polyphenol and antioxidant activity. However, there are not many studies on polyphenol from pomelo peel in Vietnam by microwave extraction. Microwave-assisted extraction helps more efficient heating, faster energy transfer, increasing or decreasing temperature control, saving solvent and cost to extract active ingredients from plant materials. This research applied microwave extraction to extract polyphenol from pomelo Citrus maxima (Burm.)Merr. The factors that affected the extraction process such as solvent concentration, microwave power, extraction time and material to solid ratio were investigated. The results obtained that the highest polyphenol content (2.46 gGAE/L) and antioxidant activity (1325.85 µmolTE/L) with ethanol concentration of 60%, microwave power of 300W, microwave-assisted time of 2 minutes, and material to solvent ratio of 1:30.
Optimization of Culture Conditions on the Proliferation of Aspergillus Terreus N-GL1 Strain Isolated from Curcuma Longa L. by Design-Expert 6.0.6 and BC Pharsoft Software
Authors: Vo T N M , Nguyen D N , Nguyen V T
Published: December 2020

Curcuma longa L. is widely used as spices and medicines. Leaves, stems and rhizomes of the plant contain essential oils and provide a useful habitat for different endophytic fungi groups. Strain of Aspergillus terreus was isolated from Curcuma longa L. and was determined to be capable of producing secondary metabolites against bacteria by disc diffusion method and optimization of culture conditions by Design-Expert 6.0.6 and BC Pharsoft software. This research identified of the culture conditions for A. terreus N-GL1 strain produced secondary metabolites against Staphylococcus aureus and MRSA (Methicillin resistant Staphylococcus aureus) good: appropriate carbon source was saccharose 1% or molasses 2,2%; suitable nitrogen sources are potatoes 10% at pH 7; initial amount of yeast cells was 104 CFU/ml; incubated at room temperature for seven day. This study was found out as suitable conditions for A. terreus N-GL1 strain produced the secondary metabolites against S. aureus and MRSA.
Effects of Vacuum Concentration on Color, Polyphenol and Flavonoid Contents and Antioxidant Activity of Pomelo Citrus maxima (Burm. f.) Merr. Juice
Authors: Nhi T T Y , Phat D T , Quyen N N , Cang M H , Truc T T , Bach L G , Muoi N V
Published: December 2020

Pomelo (Citrus maxima (Burm. f.) Merr). juice is known as an enriched source of antioxidants and nutrients. It is therefore necessary to develop a preservation method for freshly prepared juice. This study aims to determine the effect of the vacuum concentration process on the change in color, bioactive compounds and antioxidant activity of pomelo juice. High pressure showed negligible effects on color. However, longer heating time seemed to cause browning in juice. In comparison with the fresh sample, total color difference (TCD) value of the treated sample was 6.73 ± 0.58 after 150 min of heating at 85°C. The total polyphenol content (TPC) values in the sample also increased with longer heating time or increased pressure. The total flavonoid content (TFC) seemed to be non-responsive to changes in heating time and pressure but was closely related to total soluble solid. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) of pomelo juice are affected by heat and, to a lesser extent, by pressure. The changes caused by the application of vacuum dehydration in the juice texture resulted in a higher water loss and higher sugar content (52.92 ± 0.79 °Brix).
Performance and cost analysis of hydrogen production from steam reforming and dehydrogenation of ethanol
Authors: Khamhaeng P , Kim-Lohsoontorn P
Published: December 2020

Mitigation of carbon dioxide (CO2) emission has been a worldwide concern. Decreasing CO2 emission by converting it into higher value products such as methanol can be a promising way. However, hydrogen (H2) cost and availability are one of key barriers to CO2 conversion. Ethanol can be a sustainable source for H2 due to its renewable nature and easy conversion to H2-rich gas mixtures through ethanol steam reforming process. Nevertheless, steam reforming of ethanol generates CO2. Hence, this research is focused on different methods of H2 productions about a 1,665.47 t/y from ethanol for supplying to methanol plants was performed using Aspen PLUS V10. The ethanol steam reforming process required the lowest required ethanol feed for a certain amount of H2. In contrast, the ethanol steam reforming process presented significant amount of CO2 emission from reaction and electricity consumption. But the ethanol dehydrogenation of ethanol not only generates H2 without CO2 emission from the reaction but also ethyl acetate or acetaldehyde, which are value chemicals. However, ethanol dehydrogenation processes in case II and III presented relatively higher cost because by-products (ethyl acetate or acetaldehyde) were rather difficult to be separated.
Latest trends in Syngas production employing compound catalysts for methane dry reforming
Authors: Yusuf M , Farooqi A S , Keong L K , Hellgardt K , Abdullah B
Published: December 2020

The rise in the global population has ultimately steered to increase in global energy consumptions. This masqueraded several challenges worldwide. The most troublesome being the accumulation of greenhouse gases (GHGs) that induced a global climatic change. The utilization of fossil fuels like petroleum, coal and natural gas on the copious scale has led to the elevated levels of carbon dioxide (CO2) and methane (CH4) in the global environment. Dry reforming of methane (DRM) is a highly favorable technique as it utilizes two of the prominent GHGs, CH4 and CO2 to generate a useful and valuable product viz. syngas. However, the deactivation, coking and sintering of catalysts are still the main hurdles in the commercialization of the process. The compound metal catalysts have shown enhanced activity and prolonged durability when compared with monometallic catalysts due to enhanced morphology, improved and stable catalytic structure, i.e., both coke and sintering resistant at high temperatures. This brief review spotlights the recent developments in DRM by emphasizing parameters such as the effects of catalyst support, bimetallic catalyst, promoters and strong metal-support interaction (SMSI) in the last decade.
Thermochemical characterization of invasive Axonopus compressus grass as a renewable energy source
Authors: Reza M S , Afroze S , Azad A K , Sukri R S , Shams S , Taweekun J , Saghir M , Phusunti N , Abu Bakar M S
Published: December 2020

The necessity of energy is increasing massively, whereas fossil fuel resources are diminishing with time, and produce greenhouse gasses while burning. To resolve these issues, lignocellulosic biomass such as Axonopus compressus that is available in Brunei Darussalam have been investigated. For characterization analysis, dried 0.25 mm samples were utilized. The moisture content (4.56%), volatile matter (72.04%), fixed carbon (17.11%), and ash contents (6.29%) of the sample were achieved from the proximate analysis result. The HHV (Higher heating value) of 17.96 MJ/kg and the moisture content value is an indication of a reasonable source for biofuel production. The ultimate analysis showed the carbon (C), hydrogen (H), nitrogen (N), sulfur (S), and oxygen (O) contents were 43.46%, 5.68%, 1.45%, 0.13%, and 49.10%, respectively. From the thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG) results, the highest decomposition rate was found to be 6.03 wt. %/min at 334 °C temperature in pyrolysis and 30.63 wt. %/min at 443 °C temperature in combustion condition.
Characterization of Stearic Acid and Paraffin Incorporated with Aluminium as Filer for the Development of Phase Change Material Composite in Thermal Energy Storage
Authors: Abidin S Z , Ghani S A A , Osarieme UO , Jamari S S
Published: December 2020

With the increasing energy demand, shortage of energy has drawn attention towards the utilization of non-renewable energy sources. The development of thermal energy storage (TES) to fulfil the energy demand that has increased progressively over time is of great interest. TES systems are widely employed industrially especially for phase change materials (PCM) used in many fields with several applications. This study aims to synthesize, characterize and study the physicochemical and thermal properties of stearic acid and paraffin incorporated with aluminium as filler for the development of PCM composite. The PCM composites were prepared using 80wt% for the Al/SA and 80wt% Al/paraffin, respectively. The PCM composites were characterized using thermal gravimetric analysis, differential scanning calorimetry and scanning electron microscopy. Results showed good compatibility in physicochemical properties between stearic acid (SA), paraffin and aluminium (Al), respectively. It was observed that the thermal stability studied using thermal gravimetric analysis revealed slightly better stability exhibited by the paraffin PCM composite. This was as a result of the steeper slope exhibited by the stearic acid TGA curve as against that of the paraffin curve. Also, density analysis has resulted in an increment for both composite materials whereas; aluminium incorporated in paraffin composite has shown higher increment of density as compared with stearic acid composite. Therefore, PCM composite made from paraffin will be more effective as a TES material when used industrially as compared to the stearic acid PCM composite.
Synthesis of high-porosity hybrid geopolymer/alginate adsorbent for effective removal of methylene blue and optimization of parameters using RSM
Authors: Nurddin S M A S M , Sufian S , Man Z , Rabat N E , Ahmad N
Published: December 2020

In this work, high-porosity geopolymer/sodium alginate (GSA) adsorbent was successfully prepared by entrapping fly ash-based geopolymer into sodium alginate (SA) using a simple method. The geopolymer slurry was firstly prepared which involved the utilization of sodium hydroxide (NaOH) as the alkaline activator followed by the addition of SA and albumen into the slurry. Natural albumen was used as the foaming agent. The effect of mass ratio of geopolymer to SA, albumen content (wt%), NaOH concentration and curing temperature (°C) on the removal of methylene blue (MB) was investigated using one factor at time (OFAT) method and optimized by response surface methodology (RSM), which achieved by 30 run of experiments using central composite design (CCD). A quadratic model was employed to correlate all the independent variables for maximizing the MB removal through the analysis of variances (ANOVA). The model suggested that the optimum condition for the preparation of GSA adsorbent for the efficient MB removal of 84.94% was achieved with mass ratio of geopolymer to SA was 1:0.13, albumen content of 25 wt%, NaOH concentration of 7 M and curing temperature of 60 °C. The albumen content was the most effective factor in the preparation of GSA adsorbent that increased the MB removal, followed by the curing temperature and mass ratio of geopolymer to SA.
Anaerobic co-digestion for oily-biological sludge with sugarcane bagasse for biogas production under mesophilic condition
Authors: Ghaleb A A S , Kutty S R M , Ho Y C , Jagaba A H , Noor A , Al-Sabaeei A M , Kumar V , Saeed A A H
Published: December 2020

The oily-biological sludge is one of the toxic organic sludge generated from petroleum oil refineries wastewater treatment plants. However, its low Carbon/Nitrogen ratio (C/N) need a co-substrate material to meet the requirement of anaerobic digestion process C/N. The oily-biological sludge can act as a substrate and inoculum at the same time. Sugarcane bagasse is an organic waste and has high C/N ratio. Therefore, it is a proper material which can balance the batch C/N ratio. In this study, three mixing ratios for both materials with C/N ratios 20.0, 25.10 and 30.0 respectively. The temperature, mixing and digestion duration were 37 °C, 60 rpm and 33 days respectively. Both materials were pre-treated under thermo-chemical conditions to increase biogas yeild. The maximum biogas yield was for the maximum C/N and co-substrate/inoculum ratios with 9,268 mL.
Study on organic pollution treatment from Van Thanh canal water by vetiver grass model on gravel and sand in water circulation conditions
Authors: Giang L V , Le D A , Tuong L Q , Tan L V , Tran T
Published: December 2020

Most canals in Ho Chi Minh City receive urban wastewater which was led by underground sewers in the untreated cities and causes serious environmental pollution. The main objective of this paper was to investigate the effects of application models of vetiver grass in purifying wastewater in Van Thanh canal water. This model combined many vetiver grass and materials like sand, gravel, and stone to remove pollutants based on sedimentation, filtration, accumulation, and decomposition mechanisms of microorganisms that allow water to flow through the substrate, the system provides good transport of oxygen into the substrate, facilitating nitrification. The research was conducted under hydroponic conditions in three treatments (Treatment1: Gravel treatment, Treatment 2: Sand treatment, and Treatment 3: Combination material (Gravel& Sand). Each treatment was designed (n=2), with dimensions of 0.66 m x 0.46 m x 0.21 m (length, width, height), a layer of material with a thickness of 80 mm. Results showed that the average processing efficiency in the modes was PO43- 91.34%, NH4+ 96.67%, COD above 80% reaching QCVN 08: 2015/BTNMT, Vetiver had a very high capacity to purify wastewater. Result also illustrated that vetiver grass had a very high capacity to purify wastewater in Treatment 3 called the combination material of Gravel& Sand. Applying the CW CSFS system using Vetiver grass was proved for the needs of surface water treatment in Van Thanh canal water with restoring the ability of natural cleaning and restoring greenery in the whereas.
Effect of initial cod concentration and the fraction of N/P on treatment ability of Para grass (Brachiaria mutica) vegetation in the stabilization pond
Authors: Ho V T T , Pham M D , Van T L
Published: December 2020

Stabilization pond which is covered by aquatic plant is a environmentally friendly method to treat wastewater. In this study, stabilization pond using Para grass vegetation is applied to treat industrial wastewater and study the effect of intitial COD concentration and the N/P ratio on treatment abliity of para grass vegetation in the stabilization. The influent flow rate is controlled at 0.18 m3/h (corresponding to a retention time of 5.3 days). As inflow COD concentration is 203 ± 5.9 mg/L, COD treatment efficiency reaches 59.6 – 61.7%. When COD concentration in the input wastewater is 349.2 ± 4.5 mg/L, COD removal efficiency decreased to 55.7 0.9%. Continue to increase input COD concentration in the input to 512,6 ± 14,7 mg/l, COD treatment efficiency reduce to 47.9±0.6%. However, when increasing the input COD concentration corresponding to increasing the organic loading rate into the model, reached 10.270 kgCOD/ha.day at COD concentration = 512.6 ± 14,7 mg/L, twice higher than the organic loading rate of the model since COD concentration = 203 ± 5.9 mg/L. The result shows strong adaptability and wastewater treatment ability of facultative waste stabilization pond system covered by Para grass, although the input COD concentration or organic load increase more than doubled. The study also showed that the treatment efficiency of total nitrogen (TN) tends to increase when COD concentration in influent increases, with treatment effiency has reached from 57.2 to 76.4%. Besides, the fraction of nitrogen and phosphorus in influent also surveyed in this study. The fraction of N/P selected to survey in the study is approximately 2.26, 4.16 and 6.11. The results show that when increasing the N/P ratio, the efficiency of Total Nitrogen treatment tends to increase. At N/P ratio = 2.26 ± 0.19, even though the concentration of TN in the inlet is low, but nitrogen metabolism still takes place in the experimental model, so outlet TN concentration decrease to very low. The COD treatment efficiency increases gradually when increasing the N/P ratio. The output COD match Vietnam discharge standard QCVN 40:2011/BTNMT. These results show potential for applying the stabilization pond which is covered by Para grass for treating concentrated industrial wastewater.
Pineapple Peel Waste Adsorbent for Adsorption of Fe(III)
Authors: Abd Ghapar N F , Abu Samah R , Abd Rahman S
Published: December 2020

The current study discovers the capability of pineapple peel, which is an agricultural effluent, to be converted into adsorbent to be used in the removal of Fe(III). The adsorbent was prepared from pineapple peel waste using a chemical activation method impregnated with zinc chloride (ZnCl2), and the morphological and functional characterisation of the adsorbent was performed using FTIR and SEM. SEM images show rough surfaces of raw pineapple peel with creases. After the chemical treatment, substances in the pineapple peel waste such as pigments and acid-soluble oligosaccharides were removed, leading to the porous structure. Raw pineapple peel contained more functional groups, including the O–H stretching vibration at 3300 cm−1 and the C–H vibration at 2917 cm−1, compared to the adsorbent with the fading of some characteristic peaks. The ability of the adsorbent to remove Fe(III) ions at different contact times and adsorbent dosages was studied. As the contact time and adsorbent dosage were increased, the adsorption capacity also increased. The results show the potential use of pineapple peel waste as an effective adsorbent for the treatment of wastewater in removing of Fe(III) ions
Performance Study of Micro Combustor Utilising Nickel Based Catalyst on Alumina Foam Porous Support
Authors: Basir N I , Miskam M A , Sukardi M F M , Murat M N
Published: December 2020

Alumina foam was utilised as a porous medium support for catalyst in a micro combustion process using liquefied petroleum gas (LPG) as fuel. Through wet impregnation method, nickel was deposited onto the surface of alumina foam forming catalytic porous medium for micro combustion. In this study, the performance of micro combustion was investigated corresponding to three main factors based on the flame location, flue gas composition and the efficiency of combustion at lean combustion condition. It was found that combustion process started at ambient temperature produced low composition of SO2 and NOx for all experimental samples. Results also showed that combustion efficiency increases with the decrease in porosity of alumina foam used, whereby 22 % of porosity gives the highest combustion efficiency. Experiments with the deposition of active material nickel onto the alumina foam also produced similar results, where 22 % porosity of alumina foam gives the highest combustion efficiency. With nickel as active material deposited onto alumina foam, higher combustion efficiency can be achieved, with results from 40 % up to above 70 % combustion efficiency corresponding to the concentration of catalyst loading from 0.1 M to 1.0 M of Ni(NO3)2·6H2O preparation solution. Several advantages using catalytic combustion includes the capability in reducing the impact of thermal and radical quenching, easy start-up, robust to heat loss, low pollution gas emission, and operation at very lean air-to-fuel ratio condition. It has been found that the use of catalyst using porous alumina support can significantly increase the efficiency of combustion reaction and therefore improve the overall performance of micro combustion.
Effects of Different Activating Agent on the Physicochemical Properties of Rice Husk Derived Graphene (GRHA)
Authors: Arifin N F T , Yusof N , Nordin N A H M , Jaafar J , Ismail A F , Aziz F , Salleh W N W
Published: December 2020

This paper proposes the preparation of rice husk derived graphene (GRHA) via chemical activation method using two different chemical activating agents namely phosphoric acid (H3PO4) and potassium hydroxide (KOH). The purpose of this study is to study the impact of different activating agent on the physicochemical properties of GRHA. The rice husk was carbonized at 350 °C for 2 h and activated at 900 °C and 700 °C for GRHA-KOH and GRHA-H3PO4 respectively. The prepared GRHA was characterized using X-ray Diffraction (XRD) analysis, Raman Spectroscopy and BET analysis. The crystallinity of each sample shows that the prepared GRHA is in amorphous state. On the other hand, the ID/IG ratio of GRHA-KOH is 0.45 while GRHA-H3PO4 is 0.68 which suggest that both samples have high degree of graphitization. Interestingly, it was discovered that activation using KOH possesses a higher BET specific surface area (BETSSA), 518.11 m2/g as compared to H3PO4 which is only 315.07 m2/g. Thus, it shows that KOH was able to form GRHA with higher surface area and porosity.
Effect of ultrasonic waves on polymorphism and crystal size distributions of mefenamic acid
Authors: Abdul Mudalip S K , Sezali N A , Abu Bakar M R
Published: December 2020

Crystallization of pharmaceutical compound that have different polymorphic forms and broad crystal size distributions remain major challenge in industry. In this present work, the potential of ultrasonic intensifications on crystallization of mefenamic acid polymorph is investigated. The effect of sonication times (5 min – 30 min) and ultrasonic powers (153.3 – 766.7 Watt) at frequency of 65 kHz on polymorphic form and crystals size distributions (CSDs) of mefenamic acid crystals during cooling crystallization were investigated using One-Factor-At-a-Time method (OFAT). The polymorphic form, CSD and shape were determined using Fourier transform infrared spectroscopy (FTIR), Malvern Mastersizer, optical microscope and X-ray diffractometry, respectively. It was found that ultrasonic power of 766.7 Watt and 30 min of sonication time produce plate-shaped crystals with the narrow CSD. The polymorph was consistent with Form I. The findings justify the suitability of ultrasonic waves to produced plate-like mefenamic acid Form I crystals with narrow CSD.
Effect of CO2 Concentration and Liquid to Gas Ratio on CO2 Absorption from Simulated Biogas Using Monoethanolamine Solution
Authors: Rajiman V , Hairul N A H , Shariff A M
Published: December 2020

In industrial scale, removal of CO2 by chemical absorption from raw biogas represents an imperative treatment and the cutting-edge technology towards improvement of its quality and heat value. In this work, CO2 absorption studies were conducted in an absorption column packed with Sulzer metal gauze packing with simulated biogas absorbed using 30 wt. % of monoethanolamine (MEA) solution. Experimental works were conducted to determine the influence of different CO2 concentrations in feed gas (30 % and 40 %) and L/G ratio (0.6 and 0.7) and subsequently assessed in terms of CO2 absorption efficiency along the column. The results showed that 30 % CO2 in feed gas has higher removal efficiency as compared to 40 % CO2 with the ability to remove 94 % CO2 during the process. In addition, the CO2 absorption studied on the L/G ratio proved that CO2 removal was improved at higher L/G ratio of 0.7.
Performance of modified epoxy mortar using composite cement containing Ground Granulated Blast Furnace Slag (GGBS)
Authors: Md Suhaini N A , Ali N , Abdul Hamid N A , Salleh N , Abdullah S R , Othman N H , Shahidan S
Published: December 2020

The applications of modified epoxy mortar have been widely used in civil engineering construction field to reduce the usage of epoxy in strengthening applications. In the construction field, the usage of epoxy resin mortar was known as repair materials. For this research, an experimental work has been conducted on modified mortar containing epoxy with and without hardener. This research was conducted to analyze the compressive strength, density and water absorption of the specimen. The cement used for this study was a composite cement with the combination of 50% ordinary Portland cement and 50% Ground Granulated Blast Slag (GGBS). The mortars were prepared with water-cement ratio of 0.60, sand-cement ratio of 2:1 and the epoxy content of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% and 100%. In this research, the type of epoxy used is Sikadur -31 CF Normal with and without hardener. The test was carried out by using cube mortar of size 50 mm x 50 mm x 50 mm. From the experimental results, the optimal percentage of epoxy content for compressive strength and water absorption was 3%. Besides, the highest compressive strength was 31.7 MPa of modified epoxy mortar without hardener and 34.8 MPa of modified epoxy mortar with hardener. It was concluded that 3 % of epoxy was the optimal percentage for the modified mortar because of the compressive strength reached the nearest with the control mortar specimen.
Performance of Centralised Trigeneration Plant on Sensitivity Analysis of Total Site System
Authors: Jamaluddin K , Wan Alwi S R , Abd Manan Z , Hamzah K , Klemeš J J
Published: December 2020

The progressive rising of high living standards and populations’ growth has led to increasing energy demands. This has led to the energy shortage gap in both developing and developed countries. Government is developing new technology to increase the thermal efficiency of existing power systems. Trigeneration is one of the innovations that can increase the performance of power systems by reusing waste energy for heating and cooling applications. Pinch Analysis (PA) is a methodology that has been commonly applied for more than 40 years to design and optimum configurations of various resource networks. Previous studies have been performed optimisation of trigeneration system in a Total Site system based on the PA method called Trigeneration System Cascade Analysis (TriGenSCA). However, the previous study does not consider the performance of the trigeneration system through overall sensitivity analysis of Total Site system. Overall sensitivity analysis of the Total Site system that includes industrial plant’s maintenance shutdown and production changes affected the performance of the centralized trigeneration system to generate energy to be supplied to the demands. Through this analysis, the size of the trigeneration system and back-up system can be estimated taking into consideration data fluctuations probability. The methodology has been tested on the centralized nuclear trigeneration system in a Total Site system considering four industrial plants as a case study, leading to extra 3.1 MW of Low-Pressure Steam (LPS) and 7.15 MW of Hot Water (HW) are needed from the back-up system if Plant B is shut down as well as extra of 82.4 MW of HW is needed by the back-up system if Plant C is shut down. The size of the boiler and condensate system, hence, need to be improved to overcome the deficit energy as the Plants B and C are shut down.
Insulin-like growth factor 2 is produced by antral follicles and promotes preantral follicle development in macaques†
Authors: Tkachenko Olena Y , Wolf Shally , Lawson Maralee S , Ting Alison Y , Rodrigues Jhenifer K , Xu Fuhua , Bishop Cecily V , Stouffer Richard L , Xu Jing
Published: December 2020

Insulin-like growth factors (IGFs) are known for their involvement in endocrine and paracrine regulation of ovarian function. Although IGF2 is the predominant circulating and intraovarian form of IGFs in primate species, the stage-specific follicular expression, action, and regulation of IGF2 are not well defined. Therefore, experiments were conducted to investigate the follicular IGF production in response to steroid hormone regulation and the direct IGF actions on follicular development and function in vitro. Preantral follicles were isolated from rhesus macaque ovaries and cultured to the antral stage in media supplemented with follicle-stimulating hormone and insulin. Follicles were randomly assigned to treatment groups: (a) control, (b) trilostane (a steroid synthesis inhibitor), (c) trilostane + estradiol, (d) trilostane + progesterone, and (e) trilostane + dihydrotestosterone. Media was analyzed for IGF concentrations, which were correlated to follicle growth. Follicles produced IGF2, but not IGF1, at the antral stage. Steroid depletion decreased, whereas steroid replacement increased, IGF2 production by antral follicles. Media IGF2 levels correlated positively with antral follicle diameters. Macaque preantral follicles and granulosa cells were subsequently cultured without (control) and with recombinant human IGF2 supplementation. Follicle survival, growth, and paracrine factor production, as well as granulosa cell proliferation and gonadotropin receptor gene expression, were assessed. IGF2 addition increased follicle survival rates, diameters and inhibin B production, as well as granulosa cell proliferation. These data demonstrate that IGF2 produced by antral follicles, in response to steroid hormone regulation, could act as a paracrine factor that positively impacts preantral follicle development and function in primates.
Identifying the views of adolescents in five European countries on the drivers of obesity using group model building
Authors: Savona Natalie , Macauley Talia , Aguiar Anaely , Banik Anna , Boberska Monika , Brock Jessica , Brown Andrew , Hayward Joshua , Holbæk Helene , Rito Ana Isabel , Mendes Sofia , Vaaheim Fredrik , van Houten Marloes , Veltkamp Gerlieke , Allender Steven , Rutter Harry , Knai Cecile
Published: December 2020

Background

To make effective progress towards a global reduction in obesity prevalence, there needs to be a focus on broader structural factors, beyond individual-level drivers of diet and physical activity. This article describes the use of a systems framework to develop obesity prevention policies with adolescents. The aim of this research was to use the group model building (GMB) method to identify young people’s perceptions of the drivers of adolescent obesity in five European countries, as part of the EU-funded Co-Create project.

Methods

We used GMB with four groups of 16–18-year-olds in schools in each of the five European countries (The Netherlands, Norway, Poland, Portugal and the UK) to create causal loop diagrams (CLDs) representing their perceptions of the drivers of adolescent obesity. The maps were then merged into one, using a new protocol.

Results

Two hundred and fifty-seven participants, aged 16–18 years, engaged in 20 separate system mapping groups, each of which generated 1 CLD. The findings were largely congruent between the countries. Three feedback loops in the merged diagram particularly stand out: commercial drivers of unhealthy diets; mental health and unhealthy diets; social media use, body image and motivation to exercise.

Conclusions

GMB provides a novel way of eliciting from young people the system-based drivers of obesity that are relevant to them. Mental health issues, social media use and commercial practices were considered by the young people to be key drivers of adolescent obesity, subjects that have thus far had little or no coverage in research and policy.
Service crops improve a degraded monoculture system by changing common bean rhizospheric soil microbiota and reducing soil-borne fungal diseases
Authors: Abán Carla L , Verdenelli Romina , Gil Silvina Vargas , Huidobro Dina Jorgelina , Meriles José M , Brandan Carolina Pérez
Published: December 2020

Intensive agricultural practices have resulted in progressive soil degradation, with consequences on soil ecosystem services. The inclusion of service crops is a promising alternative to support the sustainability of the agricultural system. The aim of this study was to analyze in a six-year field experiment the effect of Brachiaria brizantha (perennial tropical grass) and Zea mays as service crops in a degraded common bean monoculture system in northwest Argentina. After six years, service crop treatments revealed a significant increase in most physical, chemical and biological properties of the soil (enzyme activities, microbial biomass, respiration and glomalin-related soil protein), compared with common bean monoculture. Also, a lower disease incidence was observed under B. brizantha treatments, associated with increased populations of Trichoderma spp. and Gliocladium spp. The phospholipid fatty acid profiles detected higher values of total microbial biomass under service crops. Our results suggest that the inclusion of several cycles of B. brizantha constitutes a promising soil management for recovering degraded agroecosystems.
Social sperm freezing
Authors: Pennings Guido , Couture Vincent , Ombelet Willem
Published: December 2020

Increased paternal age has been associated with lower fertility and higher genetic risk for the offspring. One way to prevent these consequences is to freeze sperm at a young age. Social sperm freezing could be developed in a way similar to social oocyte freezing. The main difference between freezing oocytes and sperm is that social sperm freezing is much less focussed on fertility preservation and much more on avoiding increased genetic risk. Contrary to what some people seem to believe, sperm freezing is more complicated than it looks at first sight. This article considers three practical aspects: freezing, storage and testing. It is concluded that the remedy (cryopreservation) may itself cause damage to the quality of the spermatozoon and to its genetic integrity, thus undoing the possible benefits in terms of fertility and health of offspring.
Semirobust analysis of an H(div)-conforming DG method with semi-implicit time-marching for the evolutionary incompressible Navier–Stokes equations
Authors: Han Yongbin , Hou Yanren
Published: December 2020

In this paper, we present a fully discrete analysis of an H(div)-conforming DG method with semi-implicit time-marching for the evolutionary incompressible Navier–Stokes equations. We use a semi-implicit time-discrete scheme in which the convection velocity is treated explicitly for the convection term. A stability analysis and a priori error estimates are given, in which the constants are independent of the negative powers of the viscosity. For inf-sup stable H(div)-conforming finite element pairs $BDM_k/P_{k-1}$ and $RT_k/P_k$, the rate of convergence $k+1/2$ is proved for the $L^2$ error of the velocity in the case of $\nu \leq C h$, where $k$ is the degree of the polynomials in the velocity approximation. In particular, for the inf-sup stable finite element pair $RT_k/P_k$, the convergence rate of the pressure is also $k+1/2$ when $\nu \leq C h$. The numerical experiments verify the analytical results.
Political Humor, Sharing, and Remembering: Insights from Neuroimaging
Authors: Coronel Jason C , O’Donnell Matthew B , Pandey Prateekshit , Delli Carpini Michael X , Falk Emily B
Published: December 2020

Over the last two decades, news-oriented comedy programs have risen to compete with traditional hard news media as sources of information about politics. To the extent that a politically knowledgeable electorate is necessary for a thriving democracy, understanding the mechanisms underlying the extent to which political comedy facilitates or inhibits a well-informed citizenry is critical. Across two studies, we use behavioral experiments and neuroimaging to examine the causal effects of humor on the desire to share and the capacity to remember political information. We find that humor increases the likelihood to share political information with others and enhances people’s memory for information. Humor also increases brain response in regions associated with understanding other people’s mental states (i.e., mentalizing), which advances a theoretical framework that humor may facilitate considerations of others’ views (e.g., how other people will respond to shared political information).
Haplotype analysis from unmanned aerial vehicle imagery of rice MAGIC population for the trait dissection of biomass and plant architecture
Authors: Ogawa Daisuke , Sakamoto Toshihiro , Tsunematsu Hiroshi , Kanno Noriko , Nonoue Yasunori , Yonemaru Jun-ichi
Published: December 2020

Unmanned aerial vehicles (UAVs) are popular tools for high-throughput phenotyping of crops in the field. However, their use for evaluation of individual lines is limited in crop breeding because research on what the UAV image data represent is still developing. Here, we investigated the connection between shoot biomass of rice plants and the vegetation fraction (VF) estimated from high-resolution orthomosaic images taken by a UAV 10 m above a field during the vegetative stage. Haplotype-based genome-wide association studies of multi-parental advanced generation inter-cross (MAGIC) lines revealed four quantitative trait loci (QTLs) for VF. VF was correlated with shoot biomass, but the haplotype effect on VF was better correlated with that on shoot biomass at these QTLs. Further genetic characterization revealed the relationships between these QTLs and plant spreading habit, final shoot biomass and panicle weight. Thus, genetic analysis using high-throughput phenotyping data derived from low-altitude, high-resolution UAV images during early stages of rice growing in the field provides insights into plant growth, architecture, final biomass, and yield.
Acoel Single-Cell Transcriptomics: Cell Type Analysis of a Deep Branching Bilaterian
Authors: Duruz Jules , Kaltenrieder Cyrielle , Ladurner Peter , Bruggmann Rémy , Martìnez Pedro , Sprecher Simon G
Published: December 2020

Bilaterian animals display a wide variety of cell types, organized into defined anatomical structures and organ systems, which are mostly absent in prebilaterian animals. Xenacoelomorpha are an early-branching bilaterian phylum displaying an apparently relatively simple anatomical organization that have greatly diverged from other bilaterian clades. In this study, we use whole-body single-cell transcriptomics on the acoel Isodiametra pulchra to identify and characterize different cell types. Our analysis identifies the existence of ten major cell type categories in acoels all contributing to main biological functions of the organism: metabolism, locomotion and movements, behavior, defense, and development. Interestingly, although most cell clusters express core fate markers shared with other animal clades, we also describe a surprisingly large number of clade-specific marker genes, suggesting the emergence of clade-specific common molecular machineries functioning in distinct cell types. Together, these results provide novel insight into the evolution of bilaterian cell types and open the door to a better understanding of the origins of the bilaterian body plan and their constitutive cell types.