bluuebunny/crossref_metadata_2025 huggingface dataset:
Above-ground biomass estimation of Eucalyptus plantation using remotely sensed data and field measurements
Authors: Wongchai W. , Insuan W. , Promwungkwa A.
Published: April 2020

Biomass has had an essential role in the energy sector of the world due to applications in bioenergy. Stand level biomass is frequently calculated from allometric models with field measurements, which is usually time-consuming and costly. They are limited because of the consideration of spatial pattern analysis of above-ground biomass (AGB) across the landscape. Therefore, the development of reliability and low-cost methods is necessary for AGB estimations in landscape level. This study aims to develop a model for estimating AGB for Eucalyptus plantation located in the Sahacogen Green Co., Ltd., in Lampang province, Thailand using remotely sensed data. The AGB value was coupled which calculated from field measurement (tree height, H and diameter at breast height, DBH) using the allometric equation with various vegetation indices. The 55 sample plots and 5 vegetation indices derived from Thailand Earth Observation System (THEOS) were used to develop a model for estimating AGB of Eucalyptus plantation. After discussing the results of the investigation, the Transformed Normalized Difference Vegetation Index (TNDVI) showed a robust correlation with AGB compared to other indices (r = 0.833). Based on stepwise linear regression between AGB and 5 vegetation indices demonstrated TNDVI was only selected while the other indices were eliminated because their relationship was not significant. The developed model R2 was 0.693, adjusted R2 was 0.684 and SEE was 12.41 Mg ha−1. The relationship between observed AGB and predicted AGB from the THEOS model of Eucalyptus plantation with R2 of 0.742 and RMSE of 9.63 Mg ha−1 indicated that remotely sensed data from THEOS can be useful for AGB estimation with high accuracy.
A simplified model of energy performance indicators for sustainable energy management
Authors: Vichan Nakthong V , Kubaha Kuskana
Published: April 2020

In international management, ISO 50001 has been widely applied in organisations across the world, including Thailand. The main objective of this standard is to continuously and sustainably improve the energy performance of the organisation in order to reduce energy consumption and costs, including alleviating environmental climate change impacts. This standard stipulates the measurement of energy performance improvement using energy performance indicators (EnPIs) and the energy baseline (EnB). This study proposes a simplified model of energy performance indicators ( EnPIs), effective for ISO 50001 energy management at organisational level. Appropriate internal benchmarking is proposed for measuring three levels of energy performance, namely organisational, process, and main machine, through energy consumption, intensity, and efficiency. Multiple linear regression was selected to develop energy equations to express the relationship between energy consumption and significantly related variables such as service usage, operating hour, and CDD for business buildings, etc. The proposed EnPIs are applied to measure the energy performance of the case study of business buildings in Thailand complying with ISO 50001. This method can be effectively used to measure changes in the energy performance of the organisation as well as the processes and considered as a comparative alternative to public benchmarking, such as kWh/m2. The findings of this study are considered to be beneficial for every organisation adopting the ISO 50001 system. This proposed method can be effectively used to monitor and measure the organisation’s energy performance towards sustainable energy management. However, it still has certain limitations. In the case of energy consumption models that are related to non-linear related variables, it is necessary to conduct further studies to determine more appropriate EnPIs.
Internet of things based metaheuristic reliability centered maintenance of distribution transformers
Authors: Venkataswamy R , Rao K Uma , Meena P
Published: April 2020

The transformer is a vital component of the power system. Continuous stress on the transformer due to overload, transient and faults will lead to physical damages. The isolation of the transformer causes significant revenue loss and inconvenience to the consumers at the distribution level. This invites the need to achieve a reliable power supply to the consumers and to perform maintenance activity appropriately. Optimized and predictive maintenance strategies are evolved to improve power availability for consumers. The model considers dispersive generation at the customer end, namely solar photovoltaics standalone system, diesel generation, and vehicle to load capabilities. Incipient or critical status of transformers’ functional parameters are observed through the transformer terminal unit and sent to the internet of things platform. The remote processing unit acquires the information from all the distribution transformer and generates the optimized and reliability-centered maintenance schedule. In the proposed work, new reliability indices concerning the consumer dispersive generation are defined. The maximization of the reliability problem is solved using the coconut tree optimization technique. The highest reliability of power supply to the consumer and maintenance schedule are obtained. Economic facet of the estimated maintenance schedule exhibit benefit for both utility and consumer as it encapsulate time of use tariff. The heuristic dataset is used to synthesize the trained model by the machine learning algorithm and future maintenance schedule is predicted. The comparative study is made for the outcome of time-based optimized and predicted maintenance schedules against reliability.
Computational appraisal of the thermalhydraulic charac-teristics of supercritical carbon dioxide in heated mini-channel for HVAC applications
Authors: Kumar Nitesh , Basu Dipankar Narayan
Published: April 2020

Over last couple of decades, supercritical fluid has found enhanced applications in numerous commercial sectors, encompassing aerospace, chemical, fast reactors, fusion rectors and renewable energy. Supercritical fluid is of major interest to the thermal engineers, primarily owing to its superior heat transport characteristics around the pseudocritical temperature. Supercritical carbon dioxide has particularly been identified as the next-generation coolant in power industry, due to its low critical temperature and reasonable critical pressure. The heating, ventilation and air-conditioning sector has also seen increasing popularity of supercritical CO2 with the phasing out of the conventional halocarbons, as it has zero ozone depletion potential and substantially smaller global warming potential. While decent volume of literature is available regarding the application of supercritical CO2 in macrochannel, thermalhydraulics of supercritical CO2 in minichannel lacks comprehensive investigation, and the present work attempts to fill that specific void through a computational appraisal of a heated horizontal minichannel of 2 mm inner diameter. Systematic simulations have been performed to explore the role of the wall heat flux ranging from 30–50 kW/m2, operating pressure ranging from 8–9 MPa, inlet temperature ranging from 295–315 K and buoyancy parameter on the thermalhydraulic characteristics of supercritical CO2. The Reynolds number in the present simulation ranges from 10000-17000. This article is aimed to explore the phenomena of heat transfer deterioration in horizontal minichannel subjected to uniform wall heat flux. It is observed that increase in wall heat flux leads to lower area-averaged heat transfer coefficient The results show an early heat transfer deterioration on top half surface whereas, normal heat transfer is observed on bottom half surface. Heat flux has significant effect on heat transfer deterioration and higher heat flux leads to reduction in peak value of heat transfer coefficient. At higher inlet temperature heat transfer coefficient decreases and peak of heat transfer coefficient shifted in the upstream direction. Also, peak of heat transfer coefficient vanishes for inlet temperature higher than pseudocritical temperature due to non-significant variation in thermophysical properties at higher temperature. Stratification of temperature, velocity and density is observed along the channel due to local buoyancy produced by non-linear thermophysical property variation of supercritical CO2.
Environmental and socio-economic assessment of wood pellet production from fast growing trees in Thailand
Authors: Saosee P. , Sajjakulnukit B. , Gheewala S. H.
Published: April 2020

Sufficient quantity of raw materials is a critical factor for wood pellet production. The recommendations from past research on biomass have indicated that the cultivation of fast growing trees should be encouraged in wasteland. Leucaena and Acacia are the popular fast growing trees in Thailand because they are resistant to drought and can grow in low quality soil. Wood from them has a high heating value and entrepreneurs invite farmers to grow these varieties on contract farming for renewable energy. The purpose of this study is to assess the environmental and socio-economic of wood pellet production from Leucaena and Acacia. The environmental impacts were evaluated by cradle to gate life cycle assessment, covering fast growing tree cultivation (sprout preparation, plantation, cutting), transportation and wood pellet production. The ReCiPe2016 Midpoint method (version 1.02) was used to evaluate the environmental impacts of one tonne wood pellet production from Leucaena and Acacia. The indicators of socio-economic considered in this study were the profit from cultivation, economic assessment of wood pellet production (net present value, internal rate of return, payback period, discount payback period and benefit cost ratio) and opportunity of employment. The environmental results showed a better performance of wood pellets made from Leucaena are better than Acacia. The production capacity of 110 tonnes per day of wood pellet factory would return a profit when the price of raw material is less than 1,300 THB per tonne. Finally, Leucaena and Acacia cultivation increase the opportunity of employment at 0.16 and 0.10 person-year per ha, respectively. The wood pellet production increases the opportunity of employment at 0.0019 person-year per tonne. Considering the results of the environmental and socio-economic assessment, Leucaena is seen to be better than Acacia and should be supported as an alternative raw material for wood pellet production.
Effective environmental management system of acid mine drainage at Kyisintaung copper surface mine in Myanmar
Authors: Aung Myint , Tin Aung Lay
Published: April 2020

Copper products are being utilized in many utilities such as electrical equipment, mechanical, architecture, and military industries. Basically the copper processing begins with the mining of copper ore which causes the environmental and social problems unless proper management systems are being exercised. This study focus on the effects of Acid Mine Drainage (AMD) of Kyisintaung mine, located near the confluence of the Yama Creek and the Chindwin River in Monywa, Sagaing region, Myanmar. To identify the effects, surface and ground water in the vicinity of the mine are sampled and analysed at the certified national laboratory. The study highlights the detailed analysis of the study programme and the results and findings have been discussed thoroughly. It has been observed that the hydrometallurgy method and zero discharging system are utilized at the mine. The results indicates that the effects of AMD around the area are insignificant because the laboratory analysis results of studied pollutants such as pH, temperature, hardness, conductivity, TDS, DO, Cu, Fe, Pb, Mg, SO4
2-are within the acceptable range of national environmental quality guideline. Finally, it has been noticed that there are no significant effects of AMD to surface and groundwater around the mine site, no water pollution sources to the environment, no serious environmental damages caused by AMD to near-by areas, and hence the adopted EMS of the mine is considered to be an effective system.
Fuel replacement: a possible option for Thailand energy security?
Authors: Nakapreecha N , Vivanpatarakij S , Audomvongseree K
Published: April 2020

Natural gas has been playing an important role in strengthening energy security of Thailand as over 60 percent of total natural gas consumed in the country is from the Gulf of Thailand. In the past 20 years, the average growth of natural gas demand is 5.5 percent per year. Thanks to its low carbon content, natural gas is considered as cleaner fuel comparing to other fossil-based fuels. Still, there are usages of carbon-intensive fuels such as fuel oil and coal in Thailand e.g. in the industrial sector. Most of fuel oil and coal consumed are imported from foreign countries. Replacing these fuels with natural gas may be an option for the country to promote domestic clean energy and reduce overall carbon emissions. This paper forecasts the possibility of replacing fuel oil and coal in the industrial sector with natural gas. The research starts with examining the limitations of Thai regulations, estimating the amount of natural gas required for the replacement, and forecasting future prices of all three fuels. The price projection shows an attractive option for fuel oil users as the long term price of natural gas is projected to be lower than that of fuel oil. On the contrary, the projected coal price alone will not encourage coal users to switch their fuels. Thus, strong government measures will be required to stimulate coal replacement. The result of the study will be useful for determining appropriate policies to support long-term demand for natural gas of the country.
Assessment of environmental, energy and economic prospective of anaerobic digestion of organic municipal solid waste in Malaysia
Authors: Yong Zi Jun , Bashir Mohammed J.K. , Hassan Mohd Sayuti
Published: April 2020

The continuous increase in population, higher living standards and economic development resulted in the inevitable increase of waste generation, energy consumption, carbon emissions and environmental degradation. The current average operating expenditure (OPEX) of a landfill is RM148/tonne/day for disposing municipal solid waste (MSW) which is an economic burden to the government. Thus, this study investigates the feasibility of biogas production from organic MSW as a renewable source of energy via anaerobic digestion. The economic and environmental benefits including the sales of electricity and fertilizer were investigated. Organic fraction municipal solid waste (OFMSW) was collected at Sahom landfill, Kampar. Waste composition was analyzed to determine the percentage of organic waste. Approximate and ultimate analysis were conducted to characterize the organic samples and to measure the calorific value. The biogas and bio-fertilizer yield were estimated. It was found that OFMSW consists 45% of the total MSW. Conversion of OFMSW to electricity and fertilizer via anaerobic digestion (AD) resulted in 3,274,812.51 m3/day of biogas which consists of 56.62% CH4 and 43.38% carbon dioxide. This can be resulted in 7,494.08 MWh/day of electrical energy and a daily yield of 13,013.73 tonnes of bio-fertilizer. This transforms the economic burden of solid waste management expenditures into an income generating movement.
Solar desalination by combination with concentrated solar power: exergy cost analysis
Authors: Leiva-Illanes Roberto , Herrera Cynthia , Alarcón-Padilla Diego , Uche Javier , Martinez Amaya
Published: April 2020

Some regions of the world with high solar irradiation conditions have a growing demand for electricity and freshwater that could cause supply problems in the industries and population. To reduce this risk, the use of solar energy to generate electricity and freshwater is an interesting option to consider. Electricity could be generated from concentrated solar power (CSP) plants fuelled by solar energy and natural gas, while freshwater could be produced from multi-effect distillation (MED) and reverse osmosis (RO) technologies driven by thermal energy and electricity, respectively. An exergy cost analysis of the integration of two desalination technologies (MED and RO) with a CSP plant is carried out to compare in terms of exergy cost. The symbolic exergoeconomics method is applied in the configurations analyzed. The different configurations are evaluated in a representative region with high irradiation conditions. Results show that the best configuration for producing electricity and freshwater is achieved when the stand-alone RO plant is connected to the grid where the unit exergy cost of electricity and water is 31% and 54% lower than in the stand-alone CSP plant and stand-alone MED, respectively. However, CSP-MED is the recommended configuration for the solar cogeneration scheme evaluated. Additionally, the most influential components in the cost formation of electricity are solar collectors (46.6% in CSP-MED and 44.3% in CSP-RO) while for freshwater they are solar collectors (27.6% in CSP-MED and 42.0% CSP-RO), multi-effect distillation module (15.7% in CSP-MED), and reverse osmosis module (20.5% in CSP-RO). In these components the design should be improved to reduce the unit exergy cost of electricity and freshwater.
Modeling of chemical processes using commercial and open-source software: A comparison between Aspen Plus and DWSIM
Authors: Tangsriwong Kwanchanok , Lapchit Puttida , Kittijungjit Tanatip , Klamrassamee Thepparat , Sukjai Yanin , Laoonual Yossapong
Published: April 2020

Computer simulation plays a key role in chemical process design. Currently, there are a large number of widely accepted commercial software. For example, Aspen Plus which was used to simulate offshore petroleum production processes, but it is often too costly to purchase and maintain a valid software license. On the other hand, since open-source software is freely accessible, the simulation models developed using open-source software could be studied, reviewed, and modified by any interested parties. This would help promoting technology transfer and knowledge dissemination in both academic and industry sectors. We specifically focus on the simulation of chemical process using the modeling software to evaluate thermal and chemical behaviour of the system which uses the chemical processes related to offshore petroleum production facilities as an example to demonstrate the software capabilities of both Aspen Plus and DWSIM. This work emphasizes on the comparison of simulation results calculated by commercial software namely Aspen Plus vs. open-source software called DWSIM (An open-source sequential modular steady state simulator) [1]. The simulation was carried out under the steady-state conditions, adiabatic processes, and negligible pressure losses. Finally, simulation results from DWSIM and Aspen Plus were compared with the heat and mass flow diagram which was used as reference. It was found that the discrepancy between simulation and reported values was in general less than 5%. It has been demonstrated that free and open-source software like DWSIM could potentially perform similar tasks as commercial software.
Utilization of mesocarp fiber and the impact of its physicochemical properties on the performance of direct carbon fuel cells
Authors: Jafri N , Wong W Y , Yoon L W , Doshi V , Cheah K H
Published: April 2020

Direct carbon fuel cell (DCFC) is a promising technology for power generation. It works on the utilization of solid carbon fuel and is high in efficiency with low emissions. In this study, biochar derived from oil palm mesocarp fibre (PMF) biomass was evaluated as a fuel supply in a DCFC based on solid-oxide electrolyte. To understand the connection between the physicochemical properties and electrochemical performance of PMF biochar (carbon fuel) in DCFCs better, the PMF biomass is subjected to acid and alkali pre-treatment for structural modification. All samples are characterized by means of thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) and scanning electron microscope (SEM) tests to obtain the link between cell performance and fuel characteristics. The maximum power density of pre-treated PMF biochars reached up to 40-55% level when compared to conventional fuels. In specific, the HCl-treated PMF biochar showed the highest electrochemical reactivity in the DCFC, giving a maximum power output of 11.8 mW cm−2 at 850 °C. It is found that after pre-treatment, the thermal stability of the biochar increases along with an increase in the surface area and pore volumes. Henceforth, these factors are believed to have a pronounced impact on the electrochemical reaction in the DCFC.
Numerical simulation of three-dimensional microbial fuel cell
Authors: Kataky Kumar Pijush , Dalal Amaresh , Biswas Gautam , Wang Chin-Tsan
Published: April 2020

Microbial Fuel Cell (MFC) has various application potential as in generation of bioelectricity, bio-hydrogen production, waste water treatment and it is also used as biosensors. It would not be possible to headway without mentioning that MFCs have quite a many similarities with Chemical Fuel Cells (CFC). It is seen that a lot of research is carried out for CFCs as compared to MFCs. Most of the research works on MFCs include experimental approach while very few computational studies have been carried out for MFCs. So an endeavour is made to create a model which mimics the working by simulating the key physical and biochemical processes occurring. Results imply that variation of current density occurs with change in Reynolds number (Re) and kinetic rate of reaction (k) which lead to the study of effects of variation of flow rates, turbulence and the action of different bacteria in the efficiency of MFCs. The current density achieved computationally is around 512 mA/m2 for Re=5 and k=10−3 which is in good agreement with the experimental data. Regions of higher current density are found which can be used to improvise the MFCs. Present mathematical model provides a new perspective in understanding the biomass concentration across the MFC and gives better knowledge of the mechanisms taking place. This simple computational framework provides insight into the fluid dynamics involved during continuous feeding, by overcoming the limitations and technical barriers in monitoring and examining through experiments. By implementing the findings from this model optimization of designs can be achieved leading to higher current generation, increase in efficacy and cost effective production techniques which paves the way for future work.
Effects of carbon supporter on oxygen reduction reaction catalytic activity in proton exchange membrane fuel cell of bimetallic Pt-Ni nanoparticles electrocatalysts
Authors: Payattikul L , Kakaen W , Punyawudho K
Published: April 2020

Platinum nanoparticles supported on carbon black (Pt/C) are widely used as the electrocatalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). Nevertheless, the kinetics of the ORR or rate of reaction is relatively slow. Recently, researchers theoretically report that, the bimetallic platinum-nickel supported on carbon black (Pt-Ni/C) have extremely high ORR activities. Therefore, this work aims to synthesize Pt-Ni/C nanoparticles electrocatalysts for ORR via solid-state chemistry method (gas phase synthesis), which involved impregnation of metal precursors on supported carbon and reducing them in an environment of carbon monoxide (CO) and hydrogen (H2) gases mixture. The Pt-Ni nanoparticles were prepared with different carbon (i.e. Graphene, Vulcan XC-72R and Ketjen black). The ORR activities and durability of these electrocatalysts were examined by voltammetry technique, which consisted of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) under acidic condition. The results demonstrated that different types of carbon supporters could affect the ORR catalytic activities. Pt-Ni nanoparticles supported on ketjen black (Pt-Ni/K) had the highest ORR activities for both specific activity (SA) and mass activity (MA). Furthermore, after 4,000 voltage cycles of the accelerated durability test (ADT), the Pt-Ni/Ketjen black still showed better ORR stability than Pt-Ni/Vulcan XC-72R and Pt-Ni/Graphene, respectively.
Preparation of low cost catalysts for proton exchange membrane fuel cell
Authors: Pimpaya Y , Konlayutt P
Published: April 2020

Nitrogen-doped reduced graphene oxide (NG) with high nitrogen level was synthesized by a facile pyrolysis. NG has been getting attention because of its high catalytic activity toward the oxygen reduction reaction (ORR) and reduce cost. The synthesis of NG used graphene oxide (GO) and urea as a N-precursor were dissolved in ethanol. Then the mixture was evaporated by ultrasonic bath for 30 min. The mixture was slurry then was transferred to tube furnace and pyrolyzed at 300°C and 800°C (NG300 and NG800) with heating rate of 2.5 °C/min in N2 atmosphere for 30 min. The morphology and structure of nitrogen doped graphene oxide were investigated by Scanning Electron Microscopy (SEM) and X-ray photoemission spectroscopy (XPS). The XPS spectra of NG indicated that NG300 had the highest intensity of N1S peak among others. Mass of nitrogen of NG300 and NG800 were evaluated and had about 15.5%wt and 6.6%wt, respectively. Furthermore, N spectra at high-resolution was analysed and de-convoluted to three N chemical states of pyridinic-N, pyrrolic-N, and graphitic-N. The electrochemical properties of NG were determined by cyclic voltammetry (CV) and Linear sweep voltammetry (LSV). From the results shown that NG800 catalyst yielded highest electrochemical activity particularly for oxygen reduction reaction (ORR) over GO and NG300. Thus, N atoms doped into the graphene were responsible for the ORR catalytic activity resulting from doping N atoms and provided more density of active sites and conductivity. Moreover, NG can be applied as a supporting material for Non-precious metal group catalysts of fuel cell.
Influence of in-house produced biochar on geotechnical properties of expansive clay
Authors: Sarkar Arijit , Pattanayak Spandan , GuhaRay Anasua , Guoxiong Mei , Zhu Hong-Hu , Garg Ankit
Published: April 2020

The current study aims to explore geotechnical properties of expansive soil amended with in-house produced biochar. Biochar was produced in-house using slow pyrolysis (at constant temperature of 500 °C) of commonly available Prosospis Juliflora (invasive weed) in a muffle furnace. This study also motivates alternative use of Prosospis Juliflora, whose reduction can help to minimize transmission of malaria and also threat to bio-diversity. The biochar was uniformly mixed with expansive black cotton soil at 5% and 10% content. Both basic and geotechnical properties (CBR and unconfined compressive strength) was determined for modified and unmodified soil samples. Based on results, it can be concluded that the plasticity index of an expansive soil is reduced significantly with an increase in biochar content. On the other hand, change in shrinkage limit was negligible. There is an increase in unconfined compressive strength and also reduction in free swell index of expansive soil amended with biochar. This is despite the significantly lower specific gravity and higher porous structure of biochar particles. The result is contrary to application of biochar in sandy soils in literature. The possible mechanism could be due to formation of bonds between negatively charged surface functional groups of biochar and positively charged ions of an expansive soil.
Gas permeability in soil amended with biochar at different compaction states
Authors: Huang He , Cai Wei-Ling , Zheng Qian , Chen Pei-Nan , Huang Chun-Rui , Zeng Qing-Jie , Kumar Himanshu , Zhu Hong-Hu , Garg Ankit , Zheenbek Kulenbekov , Kushvaha Vinod
Published: April 2020

Biochar amended soil (BAS) is widely studied to apply in green infrastructure, such as landfills and slopes. Presence of biochar improved soil hydraulic properties (e.g. water retention ability) in previous studies, while influence of biochar on gas permeability (k

g
) under different compaction states is not clear yet. The main objective of this study is to investigate the k

g
of BAS under different soil compaction conditions. The soil selected for investigation was poorly graded sand. BAS was compacted in an in-house built 1-D column set up under three different soil density (65 %, 80 % and 95% degree of compaction) were considered in mixtures with 0% and 10% biochar content. The tests were carried out in a greenhouse at Shantou University. In tests, soil column was designed and subjected to drying-wetting cycles, during which soil suction, moisture content and k

g
were measured. Results showed that BAS (i.e. minimum water content 37.2% and 22.1%) had better water retention performance than bare soil (i.e. minimum water content 20.2% and 19.5%) at compaction conditions (65% and 80% degree of compaction). However, when the degree of compaction increased to 95%, bare soil and BAS shows similar water retention characteristic (i.e. minimum water content 15.7% and 15.9% respectively). The addition of biochar could decrease k

g
as compared with that of the bare soil, meanwhile, in the lower suction range, k

g
decreased with an increase of compaction (i.e. k

g
65%>k

g
80%>k

g
95%).
Design of structure of hierarchically porous carbon monoliths with magnetic properties for high efficiency in adsorption of lead (II) ions
Authors: Onsri P , Dechtrirat D , Nooeaid P , Eiad-Ua A , Amornpitoksuk P , Chuenchom L
Published: April 2020

Pb (II) is one of the toxic heavy metal ions, which is released from the industry, especially the manufacture of batteries and electronics-devices. Its release into the water effluents causes environmental problems and affects the humans’ and animals’ health. Adsorption is one of the conventional techniques for removal of Pb (II) in water treatment processes. The adsorbents with effective adsorption properties with their easy operation are then desired. In this study, hierarchically porous carbon monoliths with magnetic properties have been designed and successfully fabricated by incorporating sodium alginate and black liquor in ferric chloride solution. The resulting monoliths have been used to study their adsorption efficiency towards Pb (II) in aqueous solution. The interconnected macroporous structures of the materials were generated by the freeze-drying process, while the increase in microporosity was observed after pyrolysis at 700 °C (SA-BL-Fe-700). SA-BL-Fe-700 showed a magnetization of 8.79 emu/g, and high porosity, with a BET specific surface area of 945.45 m2/g and pore size distribution calculated by DFT was less than 2 nm, which is suitable to adsorb Pb (II) ions. Furthermore, the materials obtained showed a monolith feature in a cylindrical shape with strong mechanical stability, which renders them with the easy operation. The adsorption properties of SA-BL-Fe-700 monolith toward Pb (II) ions demonstrated a maximum adsorption capacity of 75.19 mg/g at pH 5 with retaining the magnetic properties. The study of adsorption behaviours illustrated that equilibrium data and kinetic study fitted with Langmuir isotherm model and pseudo-second-order model, respectively.
Characterization of thermal distribution in 50-Liter biochar kiln at different heating times
Authors: Srisophon Mewadee , Khamdaeng Tipapon , Panyoyai Numpon , Wongsiriamnuay Thanasit
Published: April 2020

Biochar has been known to be an excellent soil amendment. However, the biochar yield and its quality are both affected by the process parameter, such as temperature and heating time, and the production method from kiln type used. Therefore, the objective of this work was to characterize the thermal distribution inside the 50-liter kiln at different heating times of the biochar production. The experiments on the kiln with a dimension of 500 mm × 380 mm (height × diameter) including the fuel core with diameter of 115 mm with 5 rows of 6.35 mm drill puncture diameters were conducted. The biochar was produced from 7 kg of agricultural waste corncob. The pyrolysis temperature increased with increasing heating time and it was controlled not exceeding 600 °C by adjusting the briquette fuel quantity. The results showed that the highest temperature was found at the fuel core and decreased in radial direction outwards to the kiln wall. The heating time showed effect on the thermal distribution as well as the biochar yield. The lower thermal gradient and the higher biochar yield were obtained at the higher heating time. The biochar yield would, however, decrease after optimal heating time due to the decomposition and degradation of biochar derived from corncob during the pyrolysis process. The production cost of biochar was also determined. These findings propose agriculturists the optimal heating time along with the production cost to facilitate the biochar production.
A systematic study of rheological properties of water-ironoxide nanofluids with graphene nanoflakes
Authors: Arifutzzaman A. , Ismail A. F. , Alam M. Z. , Khan A. A. , Saidur R.
Published: April 2020

Magnetic properties are the concentrated studies in iron oxide based magnetic nanofluid area; however very limited number studies have been conducted on the psychical properties of this nanofluid. The main objective of this study is to investigate the viscosity properties of Maghemite: MH (iron oxide) nanoparticles dispersed de-ionized water (DW) nanofluids (DW-MH) for the addition of graphene (Gr) nanoflakes. DW-MH nanofluids were prepared by two steps technique and graphene was added with the aid of sonication and stirring process. Viscosity were measured for every samples varied for the loading of graphene in DW-MH nanofluids. Every measurement was conducted in rising temperature varied within 20 - 60°C. Effect of both of loading of graphene and rising temperature on the viscosity properties of the fluid were systemically analysed. Prepared nanofluids were kept stabile about 30 days without any visible sedimentations. After the addition of graphene in the DW-MH nanofluids the viscosity of the final nanofluid samples was increased with the increasing loading of graphene nanoflakes. It was also detected that, hybrid nanofluids sample’s viscosity was decreasing for the increasing temperature. This nanofluid can be the viable replacement for the heat transfer purpose in the energy harvesting and storage applications due to the good physical stability.
Product lightweight research in green design
Authors: Zhao Tian-Yu , Liang Hui-Ping
Published: April 2020

The wire sawing machine is a large-scale concrete structure cutting equipment and mining quarrying machine used in the wild, in order to reduce costs and reduce energy consumption during manufacturing, transportation and use, on the premise of ensuring its performance, it is of great significance to explore its lightweight design method. This paper uses a multidisciplinary approach to construct a research method model for product lightweight design, comprehensively considering the aesthetic principles and usability principles of products, combining structural optimization theory and Kansei engineering theory, referencing three points of modeling structure, material selection and usage, through to the two aspects of physical and visual lightweight quantitative evaluation standard to determine the optimal solution for lightweight design. First, use Solidworks to build a three-dimensional model of the wire sawing machine; then, use ANSYS Workbench to perform finite element analysis on the mechanical properties of the frame to confirm it has optimization space of the frame strength; finally, through topology optimization of the frame structure and the design of the machine casing, the weight of the mainframe was reduced by 23%. The physical and visual lightweight results verifies the feasibility of the lightweight design model applied in the product design process and provides a useful reference for the sustainable development of industrial products.
Research on the creative design of express package recycling system basis on internet
Authors: Liang Hui-Ping , Li Jiagui
Published: April 2020

As E-commerce and online shopping advance swiftly and vigorously, a growing number of people choose shopping on the Internet as their major way of shopping. As the online shopping is in vogue, the problem lying in the package of express has gradually drawn people’s attention. As the data reveals, the number of paper boxes that China’s e-commerce brought about is over 10 billion. The packages of express resulted in environment pollution and waste of resources, At present, China does not yet have an efficient and comprehensive express packaging recycling system, and the only sustainable recycling design has a small application range and the effect is not obvious. For the purpose of improving the recycling rate of packages and in response to the “sustainable development strategy”, this paper, from the standpoint of consumer psychology, the real consumption situation and package recycling status quo, makes use of the Internet as the bridge to realize the design of virtual APP and recycling device, so as to form a complete recycling system of express package. This system mainly utilizes the gravity sensor, information processing system and storing and arranging device, and is backed by sophisticated techniques. The researches have shown that, the simplification of creative recycling system, the time-saving effort, high efficiency, as well as the conception of the smart classified recycling have changed the traditional way of recycling. These improvements have greatly reduced the pollution and waste that express packages caused and make the resources being used for the second time a reality.
3D printing of continuous kevlar reinforced polymer composite through coextrusion method
Authors: Tey J Y , Ding W O , Yeo W H , King Y J , Saw L H
Published: April 2020

The major drawbacks of 3D printed thermoplastic using fused deposition method (FDM) are exhibit weak mechanical properties. This reduces the usability of the printed part as the functional structure for part replacement in a real-world application. Therefore, in this study a co-extrusion of a continuous fibre of twisted Kevlar using FDM is conducted to examine the improvement of mechanical strength of the 3D printed part with reinforcement of continuous fibre. The coextruded reinforced plastic (CRP) parts consisting of polylactic acid (PLA) as matrix and twisted Kevlar as core fibre. The mechanical performance of printed parts was evaluated in a tensile test under ASTM D638 standard. The results of both CRPs were compared against unreinforced PLA which. It has been demonstrated that CRPs with twisted Kevlar was able to achieve significant increment in Ultimate tensile strength (+179.7%, 104.64MPa), maximum tensile strain (+257%, 5.384%) and relative similar Young’s modules (3.29GPa) compared to unreinforced PLA. As a result, this study created a unique material print which CRP with twisted Kevlar which offer high stiffness and high strength structure.
Thermal decomposition, phase formation and microstructure analysis of surfactant assisted sol-gel derived La0.6Sr0.4CoO3-δmaterial
Authors: Samat Abdullah Abdul , Alias Siti Hajar , Darus Murizam , Somalu Mahendra Rao , Baharuddin Nurul Akidah , Osman Nafisah
Published: April 2020

A single-phase of perovskite-type oxide material can be prepared at a processing temperature relatively lower than 1000 °C through a sol-gel method. However, it is affected by the nature of chemical additives employed during the synthesis process. In the present work, sol-gel derived lanthanum strontium cobaltite, La0.6Sr0.4CoO3-δ(LSC64) material is prepared using various non-ionic surfactants namely polyoxyethylene (10) oleyl ether (Brij-97), polyoxyethylene octyl phenyl ether (Triton-X-100) and polyoxyethylene (20) sorbitan monooleate (Tween-80). The prepared powders of the LSC material is subsequently subjected to the thermal decomposition, phase formation and microstructure analysis by a thermal gravimetric analyzer, an X-ray diffractometer and a scanning electron microscope (SEM), respectively. The as-synthesized powders are calcined at different temperatures based on the thermal gravimetric analysis results. X-ray diffractometer results reveal that all of the calcined powders consist of more than 90 % perovskite phase of LSC64 and other secondary phases such as cobalt oxide, lanthanum oxide and strontium carbonate. The Brij-97-based and Tween-80-based calcined powders have morphology of typical clump-like network structure, while the Triton-X-100-based calcined powder has morphology of flake-like network structure.
Computational fluid dynamics simulation on the effect of pillar shapes on chitosan-coated zinc oxide nanoparticles flows in pillar-based microfilter
Authors: Majnis Mohd Fadhil , Koman Erwin , Ku Shaari Ku Zilati
Published: April 2020

The computational fluid dynamics (CFD) simulation on the effect of pillar shapes on chitosan-ZnO nanoparticles flows in pillar-based microfilter was considered using ANSYS Fluent in the laminar flow condition. Three shapes of the pillar were studied: cylindrical, cuboid, and rotated cuboid pillar. The volume of fluid (VOF) method was performed under a certain set of considerations and assumptions in order to validate the microfilter design to have the same flow patterns based on the literature. The discrete phase model (DPM) was carried out in order to simulate and analyze the chitosan-ZnO nanoparticles flow behaviour and separation efficiency performance in pillar-based microfilter. The DPM was carried out in 200, 300, and 400 streams to track the position of the nanoparticles in order to analyze the separation performance for each pillar shape. The simulation involved a different number of streams that were observed on the impact of nanoparticle Reynolds number and the total number of nanoparticles. It was observed that microfilter-C (rotated cuboid pillar) has the best separation efficiency of chitosan-ZnO nanoparticles compared to microfilter-A (cylindrical pillar) and microfilter-B (cuboid pillar) based on the particle position from the outlet of microfilter which was 2.5 mm, 0.08 mm, and 2.1 mm respectively. The shape of the pillar is a critical parameter that plays a significant role in the separation performance of nanoparticles in pillar-based microfilter.
A study on the low-temperature wet synthesis of hydrofluoric acid from synthetic calcium fluoride and waste sulfuric acid
Authors: Lin Min-Fa , Chang Chih-Ping , Chang Ken-Lin , Lee Wen-Jhy , Wu Jhong-Lin , Chen Po-Han
Published: April 2020

An innovative method for utilizing synthetic calcium fluoride (CaF2), recovered from fluoride-containing semiconductor wastewater, and waste sulfuric acid (H2SO4) to produce hydrofluoric acid (HF) was investigated. The research was set to study the low-temperature production of HF via the reaction of synthetic CaF2 and waste H2SO4. The impact of H2SO4 concentration and total volume (H2SO4 + H2O)/CaF2 ratio, drying temperature of synthetic CaF2 on HF productivity were investigated in this study. HF yield increased with increasing H2SO4 concentration and total volume/CaF2 ratio under room temperature. In addition, the HF produced in the reactions involving the 105 °C-dried synthetic CaF2 were higher than the 600 °C-dried synthetic CaF2 ones. The study will not only find uses for this semiconductor wastes but also provide a greener alternative to the current commercial production of HF.
Bioconversion of anthocyanin to anthocyanidin from fermented fruit and vegetable waste by Leuconostoc mesenteroides as probiotik food material
Authors: Hidayat H. , Fadilah E. , Nurmadina  , Musawwa M.M.
Published: April 2020

Organic waste, especially fruit and vegetables is currently a major problem in the world due to serious risks to human health and the environment. On the other hand, fruit and vegetable waste contains anthocyanin (flavonoid of polyphenol) compounds that can produce antioxidant to inhibit oxidation reaction caused by free radicals such as diseases that exist in the digestive tract. it has been an important thing to make a bioproduct solution associated with the animal element’s feed ingredients. The result of this study showed that an anthocyanidin from isolates fruit and vegetable was successfully identified by (i) fermentation time variations used are 0; 1; 3; 5 and 7 days resistant to acid pH 4. The compound isolation process use liquid-liquid extraction method with ethanol 96% by diluting 1:3 in the anaerobic jar (ii) Lactic Acid Bacteria (LAB) were gram positive purple colored and basil shape based on Gram staining (iii) thus, an antimicrobial activity was shown by clear zone with E15 which were 18 mm, 20 mm and 24 mm from 72 hours incubation on nutrient media Euschericia coli.
Integration of semi-batch cultivation and extraction for maximal lipid production in Chlamydomonas sp. Tai-03
Authors: Tan Chung Hong , Show Pau Loke
Published: April 2020

Rapid improvements in bioseparation technology, new regulatory directives, product quality constraints, and the production efficiency have necessitated the development of more advanced and powerful downstream bioprocesses for biotechnology and biopharmaceuticals industrial. This has transformed in dramatically improvements in traditional bioseparation processes as well as the development of entirely new approaches. In this paper, we highlight some of these recent advances of integration of semi-batch cultivation and extraction for maximal lipid production in Chlamydomonas sp. Tai-03. This includes extractive cultivation, extractive bioconversion aqueous two-phase system, aqueous two-phase flotation, and newly developed liquid biphasic flotation. Alcohol/salt liquid biphasic flotation (LBF) with aid of ultrasonication which have the ability of killing two birds with one stone, it not only capable in cell rupturing, it also able to recover bioproducts simultaneously and continuously. The effect of varying crude feedstock concentration, flotation time, type of salt, concentration of salt, type of alcohol, concentration of alcohol, initial volumes of salt and alcohol were investigated. Microalgal biofuels or generation three biofuels have been widely recognized as potential replacements of fossil fuels. One of the most attractive option is the partial or full replacement of diesel fuel with microalgal biodiesel. Here, Chlamydomonas sp. Tai-03 was cultured using semi-batch cultivation to enhance its lipid production. Upon lowering the culture replacement fraction to 25%, the greatest biomass and lipid productivities were obtained at 1.23 ± 0.02 g/L/d and 239.6 ± 24.8 mg/L/d. After transesterification, palmitic acid (C16:0), oleic acid (C18:1), and linoleic acid (C18:2) were the main fatty acid methyl esters (FAMEs) present. These short-chain FAMEs and high productivities of Chlamydomonas sp. Tai-03 are suitable for biodiesel output.