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Identification of Microbial Flora in Dry Aged Beef to Evaluate the Rancidity during Dry Aging
Sejeong Kim, Jong-Chan Kim, Sunhyun Park, Jinkwi Kim, Yohan Yoon, Heeyoung Lee
February 23, 2023 (v1)
Keywords: dry aged beef, index, microbial flora, rancidity
Dry aging creates a unique taste and flavor in beef; however, the process also causes rancidity, which is harmful to humans. During dry aging, the microbial flora in beef changes continuously; thus, this change can be used as an indicator of rancidity. The objective of this study was to analyze the correlation between microbial flora in beef and rancidity during dry aging. The round of beef (2.5−3 kg) was dry aged under 1.5 ± 1 °C and 82 ± 5% moisture for 17 weeks. The microflora in the dry aged beef was analyzed by pyrosequencing. The volatile basic nitrogen (VBN) and thiobarbituric acid reactive substance (TBARS) values were also measured. Primers were designed to detect and quantify bacteria using real-time polymerase chain reaction (RT-PCR). The VBN and TBARS values in the dry aged beef depreciated from week 11 of aging. The levels of Streptococcus spp., Pantoea spp., and Pseudomonas spp. significantly changed at around week 11. Quantitative RT-PCR showed that the levels of Pantoea... [more]
Mathematical Study of a Two-Stage Anaerobic Model When the Hydrolysis Is the Limiting Step
Mohammed Hanaki, Jérôme Harmand, Zoubida Mghazli, Alain Rapaport, Tewfik Sari, Pablo Ugalde
February 23, 2023 (v1)
Keywords: anaerobic digestion, commensal system, mortality, operating diagrams, stability, steady state
A two-step model of the anaerobic digestion process is mathematically and numerically studied. The focus of the paper is put on the hydrolysis and methanogenesis phases when applied to the digestion of waste with a high content of solid matter: existence and stability properties of the equilibrium points are investigated. The hydrolysis step is considered a limiting step in this process using the Contois growth function for the bacteria responsible for the first degradation step. The methanogenesis step being inhibited by the product of the first reaction (which is also the substrate for the second one), and the Haldane growth rate is used for the second reaction step. The operating diagrams with respect to the dilution rate and the input substrate concentrations are established and discussed.
Adsorption of Cr(OH)n(3−n)+ (n = 1−3) on Illite (001) and (010) Surfaces: A DFT Study
Jia Du, Leilei Fan, Qinghe Wang, Fanfei Min
February 23, 2023 (v1)
Subject: Materials
Keywords: adsorption mechanism, DFT, hydroxyl chromium(III), illite
The development of clay adsorption materials with high Cr(III) removal capacities requires an understanding of the adsorption mechanism at the atomic level. Herein, the mechanisms for the adsorption of Cr(OH)2+, Cr(OH)2+, and Cr(OH)3 on the (001) and (010) surfaces of illite were studied by analyzing the adsorption energies, adsorption configurations, charges, and state densities using density functional theory (DFT). The adsorption energies on the illite (010) and (001) surfaces decrease in the order: Cr(OH)2+ > Cr(OH)2+ > Cr(OH)3. In addition, the energies associated with adsorption on the (010) surface are greater than those on the (001) surface. Further, the hydrolysates are highly active and can provide adsorption sites for desorption agents. The silica (Si−O) ring on the illite (001) surface can capture Cr(OH)n(3−n)+ (n = 1−3). In addition, both Cr(OH)2+ and Cr(OH)2+ form one covalent bond between Cr and surface OS1 (Cr−OS1), whereas the hydroxyl groups of Cr(OH)3 form three hydr... [more]
Process Intensification in Photocatalytic Decomposition of Formic Acid over a TiO2 Catalyst by Forced Periodic Modulation of Concentration, Temperature, Flowrate and Light Intensity
Thomas Ellwood, Luka A. Živković, Petr Denissenko, Rufat Sh. Abiev, Evgeny V. Rebrov, Menka Petkovska
February 23, 2023 (v1)
Keywords: forced periodic modulation, formic acid decomposition, non-stationary CSTR, Process Intensification, TiO2
The effect of forced periodic modulation of several input parameters on the rate of photocatalytic decomposition of formic acid over a TiO2 thin film catalyst has been investigated in a continuously stirred tank reactor. The kinetic model was adopted based on the literature and it includes acid adsorption, desorption steps, the formation of photocatalytic active sites and decomposition of the adsorbed species over the active titania sites. A reactor model was developed that describes mass balances of reactive species. The analysis of the reactor was performed with a computer-aided nonlinear frequency response method. Initially, the effect of amplitude and frequency of four input parameters (flowrate, acid concentration, temperature and light intensity) were studied. All single inputs provided only a minor improvement, which did not exceed 4%. However, a modulation of two input parameters, inlet flowrate and the acid molar fraction, considerably improved the acid conversion from 80 to 9... [more]
Predictive Analysis of Municipal Solid Waste Generation Using an Optimized Neural Network Model
Nehal Elshaboury, Eslam Mohammed Abdelkader, Abobakr Al-Sakkaf, Ghasan Alfalah
February 23, 2023 (v1)
Keywords: hybrid neural network, municipal solid waste, Particle Swarm Optimization, predictive modelling, trend analysis
Developing successful municipal waste management planning strategies is crucial for implementing sustainable development. The research proposed the application of an optimized artificial neural network (ANN) to forecast quantities of waste in Poland. The neural network coupled with particle swarm optimization (PSO) algorithm is compared to the conventional neural network using five assessment metrics. The metrics are coefficient of efficiency (CE), Pearson correlation coefficient (R), Willmott’s index of agreement (WI), root mean squared error (RMSE), and mean bias error (MBE). Selected explanatory factors are incorporated in the developed models to reflect the influence of economic, demographic, and social aspects on the rate of waste generation. These factors are population, employment to population ratio, revenue per capita, number of entities by type of business activity, and number of entities enlisted in REGON per 10,000 population. According to the findings, the ANN−PSO model (C... [more]
A Mini Review on Pyrolysis of Natural Algae for Bio-Fuel and Chemicals
Wei Xu, Keqiang Ding, Lihua Hu
February 23, 2023 (v1)
Subject: Materials
Keywords: bio-based chemicals, bio-fuel, Catalysis, natural algae, pyrolysis
The disposal and use of natural algae have recently been the subject of great interest, due to increasing concern for environmental protection and resource utilization. In this paper, a mini review of recent research on the pyrolysis of natural algae, especially the algae from water blooms, is presented. The chemical compositions of the natural algae are summarized, and the pyrolysis properties of different compositions are reviewed. Non-catalytic, catalytic, and integrated catalytic processes are reviewed. Different ideas and methods for the production of bio-fuel or chemicals are discussed. Apparently, deoxygenation and denitrogenation are highly necessary for algae-based bio-fuel and catalysts play an important role in these processes. In addition, the integrated catalytic process, which involves catalysis and other operation conditions aside from the thermal treatment under inert atmosphere, shows potential for the valorization of algae-based bio-oil. Based on the recent concept an... [more]
Optimization of No-Wait Flowshop Scheduling Problem in Bakery Production with Modified PSO, NEH and SA
Majharulislam Babor, Julia Senge, Cristina M. Rosell, Dolores Rodrigo, Bernd Hitzmann
February 23, 2023 (v1)
Keywords: bakery industry, no-wait flowshop, Optimization, production efficiency
In bakery production, to perform a processing task there might be multiple alternative machines that have the same functionalities. Finding an efficient production schedule is challenging due to the significant nondeterministic polynomial time (NP)-hardness of the problem when the number of products, processing tasks, and alternative machines are higher. In addition, many tasks are performed manually as small and medium-size bakeries are not fully automated. Therefore, along with machines, the integration of employees in production planning is essential. This paper presents a hybrid no-wait flowshop scheduling model (NWFSSM) comprising the constraints of common practice in bakeries. The schedule of an existing production line is simulated to examine the model and is optimized by performing particle swarm optimization (PSO), modified particle swarm optimization (MPSO), simulated annealing (SA), and Nawaz-Enscore-Ham (NEH) algorithms. The computational results reveal that the performance... [more]
R-CNN-Based Large-Scale Object-Defect Inspection System for Laser Cutting in the Automotive Industry
Donggyun Im, Jongpil Jeong
February 23, 2023 (v1)
Keywords: Artificial Intelligence, automotive industry, defect inspection, laser cutting, R-CNN
A car side-outer is an iron mold that is applied in the design and safety of the side of a vehicle, and is subjected to a complicated and detailed molding process. The side-outer has three features that make its quality inspection difficult to automate: (1) it is large; (2) there are many objects to inspect; and (3) it must fulfil high-quality requirements. Given these characteristics, the industrial vision system for the side-outer is nearly impossible to apply, and indeed there is no reference for an automated defect-inspection system for the side-outer. Manual inspection of the side-outer worsens the quality and cost competitiveness of the metal-cutting companies. To address these problems, we propose a large-scale Object-Defect Inspection System based on Regional Convolutional Neural Network (R-CNN; RODIS) using Artificial Intelligence (AI) technology. In this paper, we introduce the framework, including the hardware composition and the inspection method of RODIS. We mainly focus o... [more]
The Analysis of Chlorogenic Acid and Caffeine Content and Its Correlation with Coffee Bean Color under Different Roasting Degree and Sources of Coffee (Coffea arabica Typica)
Chia-Fang Tsai, Irvan Prawira Julius Jioe
February 23, 2023 (v1)
Keywords: caffeine, chlorogenic acid, Coffea arabica, coffee bean color
Coffee is one of the main economic crops in the world and is now widely grown throughout Taiwan. The process of roasting coffee begins with the heating and smooth expansion of raw beans, which leads to changes in appearance and color while affecting the flavor and taste of coffee. So far, most coffee manufacturers have used visual inspection or colorimeter methods to identify differences in coffee quality. Moreover, there is no literature discussing the correlation of roasted bean color with caffeine and chlorogenic acid content. Therefore, the purpose of this experiment was to analyze the chlorogenic acid and caffeine content and their correlation with bean color under different roasting degrees and from different sources to establish basic data for the rapid identification of coffee quality in the future. In this experiment, the coffee Coffea arabica typica from Dongshan, Gukeng, and Sumatra’s Indonesian rainforest was used, and the beans were roasted into four degrees: raw bean, lig... [more]
Diazotrophic Behaviour in a Non-Sterile Bioreactor: The Effect of O2-Availability
Amber Yasemin Shirin de Zoete, Hendrik Gideon Brink, Joshua Cornelus Beukes, Ignatius Leopoldus van Rooyen, Willie Nicol
February 23, 2023 (v1)
Keywords: ATP down-regulation, bio-fertilizer, diazotrophs, nitrogen fixation
The behaviour of a locally isolated diazotrophic consortium was investigated with the prospect of agricultural applications. A repeatable culture was obtained in a non-sterile bioreactor. Metagenomic analysis indicated Chryseobacterium ssp. and Flavobacterium ssp. were the dominant species, making up approximately 50% of the microbial community. The oxygen supply was varied and mass-transfer limited growth was attained under all experimental conditions. Negligible amounts of aqueous metabolites were formed, indicating a high selectivity towards biomass production. High oxygen availability resulted in decreased growth efficiencies i.e., the specific energy requirements for biomass synthesis. This was attributed to reduced electron transport chain efficiencies and nitrogenase protection mechanisms. Mass and energy balances indicated that sessile biomass with a high C:N served as a carbon sink. The most efficient growth was measured at an aeration feed composition of 21% oxygen and 79% ni... [more]
Bioreactor Rhamnolipid Production Using Palm Oil Agricultural Refinery By-Products
Mohd Nazren Radzuan, James Winterburn, Ibrahim Banat
February 23, 2023 (v1)
Keywords: biorefinery, biosurfactant, Fermentation, Pseudomonas aeruginosa PAO1, rhamnolipid
Palm fatty acid distillate (PFAD) and fatty acid methyl ester (FAME) are used by P. aeruginosa PAO1 to produce rhamnolipid biosurfactant. The process of fermentation producing of biosurfactant was structured in a 2 L bioreactor using 2% of PFAD and FAME as carbon sources in minimal medium and with a nitrogen concentration of 1 g L−1. Mass spectrometry results show the crude biosurfactant produced was predominantly monorhamnolipid (Rha-C10-C10) and dirhamnolipid (Rha-Rha-C10-C10) at 503 and 649 m/z value for both substrates. Maximum production of crude rhamnolipid for PFAD was 1.06 g L−1 whereas for FAME it was 2.1 g L−1, with a reduction in surface tension of Tris-HCl pH 8.0 solution to 28 mN m−1 and a critical micelle concentration (CMC) of 26 mg L−1 measured for both products. Furthermore, the 24 h emulsification indexes in kerosene, hexadecane, sunflower oil, and rapeseed oil using 1 g L−1 of crude rhamnolipid were in the range 20−50%. Consequently, PFAD and FAME, by-products from t... [more]
Impact of Various Essential Oils and Plant Extracts on the Characterization of the Composite Seaweed Hydrocolloid and Gac Pulp (Momordica cochinchinensis) Edible Film
Thuy Thi Bich Tran, Boi Ngoc Vu, Md Saifullah, Minh Huu Nguyen, Penta Pristijono, Timothy Kirkman, Quan Van Vuong
February 23, 2023 (v1)
Subject: Materials
Keywords: characterization, edible film, essential oils, plant extracts
Edible films and coatings have currently received increasing interest because of their potential in food applications. This study examined the effect of incorporated essential oils and natural plant extracts on the characteristics of the composite seaweed hydrocolloid and gac pulp films. Films were prepared by a casting technique, followed by measurement of physical, optical, barrier, mechanical, and structural properties. The results showed that adding plant oils and extracts significantly affected the physical, optical, mechanical, and structural properties of the composite films. Incorporation of the essential oils resulted in a reduction in moisture content and opacity while increasing values for Hue angle and elongation at break of the composite films. Besides, incorporation of the plant extracts showed increases in thickness, opacity, ΔE, Chroma, and elongation at the break, while there is a decrease in the Hue angle values of the composite films. In conclusion, incorporating pla... [more]
Data-Driven Evaluation and Optimization of Agricultural Sustainable Development Capability: A Case Study of Northern Anhui
Muchen Luo, Fan Liu, Jianqing Chen
February 23, 2023 (v1)
Subject: Environment
Keywords: agricultural process optimization, agricultural sustainable development capability, data driven, economic and environmental index system, resource efficiency
Human survival depends on the sustainable development of agriculture. This study constructs a data-driven evaluation and optimization method of agricultural sustainable development capacity, aiming to better cope with challenges such as environmental pollution and excessive consumption of resources and energy, as well as improve agricultural economic level. Further, an evaluation index system was constructed based on comprehensive consideration of energy and resources utilization, environmental pollution, and agricultural economy. After simplifying and integrating the data, a data envelopment analysis model was constructed to quantitatively evaluate the capability for agricultural sustainable development and its changing trend. Moreover, its influencing factors were analyzed from the perspective of input, which provides accurate countermeasures for improving agricultural sustainable development ability, resource utilization efficiency, and process optimization. This study shows the rea... [more]
Mycotoxins—Prevention, Detection, Impact on Animal Health
Jagoda Kępińska-Pacelik, Wioletta Biel
February 23, 2023 (v1)
Subject: Materials
Keywords: aquaculture animals, companion animals, detection, farm animals, mycotoxin, prevention, safety
Mycotoxins are defined as secondary metabolites of some species of mold fungi. They are present in many foods consumed by animals. Moreover, they most often contaminate products of plant and animal origin. Fungi of genera Fusarium, Aspergillus, and Penicillum are most often responsible for the production of mycotoxins. They release toxic compounds that, when properly accumulated, can affect many aspects of breeding, such as reproduction and immunity, as well as the overall liver detoxification performance of animals. Mycotoxins, which are chemical compounds, are extremely difficult to remove due to their natural resistance to mechanical, thermal, and chemical factors. Modern methods of analysis allow the detection of the presence of mycotoxins and determine the level of contamination with them, both in raw materials and in foods. Various food processes that can affect mycotoxins include cleaning, grinding, brewing, cooking, baking, frying, flaking, and extrusion. Most feeding processes... [more]
Verification of the Potential Targets of the Herbal Prescription Sochehwan for Drug Repurposing Processes as Deduced by Network Pharmacology
Dong-Woo Lim, Da-Hoon Kim, Ga-Ram Yu, Won-Hwan Park, Jai-Eun Kim
February 23, 2023 (v1)
Subject: Biosystems
Keywords: drug repurposing, GO enrichment analysis, key target validation, network pharmacology, Sochehwan
Network pharmacology (NP) is a useful, emerging means of understanding the complex pharmacological mechanisms of traditional herbal medicines. Sochehwan (SCH) is a candidate herbal prescription for drug repurposing as it has been suggested to have beneficial effects on metabolic syndrome. In this study, NP was adopted to complement the shortcomings of literature-based drug repurposing strategies in traditional herbal medicine. We conducted in vitro studies to confirm the effects of SCH on potential pharmacological targets identified by NP analysis. Herbal compounds and molecular targets of SCH were explored and screened from a traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP) and an oriental medicine advanced searching integrated system (OASIS). Forty-seven key targets selected from a protein-protein interaction (PPI) network were analyzed with gene ontology (GO) term enrichment and KEGG pathway enrichment analysis to identify relevant categories.... [more]
Simultaneous Quantitative Detection of HCN and C2H2 in Combustion Environment Using TDLAS
Wubin Weng, Marcus Aldén, Zhongshan Li
February 23, 2023 (v1)
Subject: Environment
Keywords: acetylene, biomass/waste, combustion/gasification, hot water interference, hydrogen cyanide, tunable diode laser absorption spectroscopy
Emission of nitrogen oxides (NOx) and soot particles during the combustion of biomass fuels and municipal solid waste is a major environmental issue. Hydrogen cyanide (HCN) and acetylene (C2H2) are important precursors of NOx and soot particles, respectively. In the current work, infrared tunable diode laser absorption spectroscopy (IR-TDLAS), as a non-intrusive in situ technique, was applied to quantitatively measure HCN and C2H2 in a combustion environment. The P(11e) line of the first overtone vibrational band v1 of HCN at 6484.78 cm−1 and the P(27e) line of the v1 + v3 combination band of C2H2 at 6484.03 cm−1 were selected. However, the infrared absorption of the ubiquitous water vapor in the combustion environment brings great uncertainty to the measurement. To obtain accurate temperature-dependent water spectra between 6483.8 and 6485.8 cm−1, a homogenous hot gas environment with controllable temperatures varying from 1100 to 1950 K provided by a laminar flame was employed to per... [more]
Closed-Cell Powder Metallurgical Aluminium Foams Reinforced with 3 vol.% SiC and 3 vol.% Graphite
Jaroslav Kováčik, Martin Nosko, Natália Mináriková, František Simančík, Jaroslav Jerz
February 23, 2023 (v1)
Subject: Materials
Keywords: aluminium foams, closed-cell foam, composites, graphite discipline, powder metallurgy, silicon carbide
Closed-cell aluminium foams (nominal composition: AlSi12Mg0.6Fe0.3) were prepared by the powder metallurgical route (using 0.4 wt.% TiH2 untreated powder as the foaming agent). Pure foams and foams with the addition of 3 vol.% graphite or SiC powder were prepared. The microstructure and mechanical properties of the prepared aluminium foams containing reinforcing particles were investigated at constant density and compared to those of the pure foam. Vibration measurements were performed to determine the damping properties and modulus of elasticity of the foams. Uniaxial compression tests were performed to determine the following mechanical properties: collapse stress, efficiency of energy absorption, plateau length and densification strain of the foams. All the foams behaved in a brittle manner during compression. Finally, the effect of admixed graphite and SiC powders on the properties of the investigated foam was evaluated, discussed and modelled. The addition of powders changed all i... [more]
Biomass Combustion Control in Small and Medium-Scale Boilers Based on Low Cost Sensing the Trend of Carbon Monoxide Emissions
Jana Mižáková, Ján Piteľ, Alexander Hošovský, Ivan Pavlenko, Marek Ochowiak, Serhii Khovanskyi
February 23, 2023 (v1)
Keywords: biomass combustion, CO emissions, combustion stabilization, lambda probe, process control
The article deals with the possibility of efficient control of small and medium-scale biomass-fired boilers by implementing low-cost sensors to sense the trend of carbon monoxide emissions into control of the biomass combustion process. Based on the theoretical analysis, a principle block diagram of the process control system was designed for the possibility of providing near-optimal control of the biomass combustion regardless of its quality parameters. A cost-effective hardware solution to obtain the dependence of CO emissions on O2 concentration in flue gas during combustion and new control algorithms was implemented into the process control and monitoring system of the biomass-fired boilers to test them in the real operation. A description of the designed control system, a data analysis of the monitored values and their impact on combustion process, and some results of the implemented control of the real biomass combustion process are presented in the article.
Numerical Modelling and Multi Objective Optimization Analysis of Heavy Vehicle Chassis
Abhishek Agarwal, Linda Mthembu
February 23, 2023 (v1)
Keywords: CCD, DOE, heavy vehicle chassis, optimizations, stress
The primary supporting structure of an automobile and its other vital systems is the chassis. The chassis structure is required to bear high shock, stresses, and vibration, and therefore it should possess adequate strength. The objective of current research is to analyze a heavy motor vehicle chassis using numerical and experimental methods. The CAD design and FE analysis is conducted using the ANSYS software. The design of the chassis is then optimized using Taguchi design of Experiments (DOE); the optimization techniques used are the central composite design (CCD) scheme and optimal space filling (OSF) design. Thereafter, sensitivity plots and response surface plots are generated. These plots allow us to determine the critical range of optimized chassis geometry values. The optimization results obtained from the CCD design scheme show that cross member 1 has a higher effect on the equivalent stresses as compared to cross members 2 and 3. The chassis mass reduction obtained from the C... [more]
MRlogP: Transfer Learning Enables Accurate logP Prediction Using Small Experimental Training Datasets
Yan-Kai Chen, Steven Shave, Manfred Auer
February 23, 2023 (v1)
Keywords: lipophilicity prediction, logP prediction, physicochemical property prediction, transfer learning
Small molecule lipophilicity is often included in generalized rules for medicinal chemistry. These rules aim to reduce time, effort, costs, and attrition rates in drug discovery, allowing the rejection or prioritization of compounds without the need for synthesis and testing. The availability of high quality, abundant training data for machine learning methods can be a major limiting factor in building effective property predictors. We utilize transfer learning techniques to get around this problem, first learning on a large amount of low accuracy predicted logP values before finally tuning our model using a small, accurate dataset of 244 druglike compounds to create MRlogP, a neural network-based predictor of logP capable of outperforming state of the art freely available logP prediction methods for druglike small molecules. MRlogP achieves an average root mean squared error of 0.988 and 0.715 against druglike molecules from Reaxys and PHYSPROP. We have made the trained neural network... [more]
Facial Eco-Friendly Synthesis of Copper Oxide Nanoparticles Using Chia Seeds Extract and Evaluation of Its Electrochemical Activity
Noha Al-Qasmi
February 23, 2023 (v1)
Subject: Materials
Keywords: characterization, chia extract, CuO nanoparticles, green synthesis, metal oxide
In the current study, copper oxide nanoparticles (CuO NPs) were synthesized using chia seed extract in a simple, rapid, and eco-friendly manner for the first time. The synthesized CuO NPs were characterized using different analytical techniques. The images of field emission scanning electron microscopy revealed that the CuO NPs were triangular and pyramid in structure, with a mean particle size of 61.5 nm. The absorption peak of the synthesized CuO NPs was measured using ultraviolet-visible spectroscopy and was recorded at a wavelength of 291 nm. The results of energy-dispersive X-ray analysis confirmed that the CuO NPs synthesized using chia seed extract yielded high-purity CuO NPs. Moreover, the X-ray diffraction analysis indicated the highly crystalline nature of the CuO NPs, and the X-ray photoelectron spectroscopy results indicated that the CuO NPs were prepared successfully. Additionally, electrochemical impedance spectroscopy measurements revealed excellent electrocatalytic cond... [more]
The Process and Platform for Predicting PM2.5 Inhalation and Retention during Exercise
Hui-Chin Wu, Ai-Lun Yang, Yue-Shan Chang, Yu-Hsiang Chang, Satheesh Abimannan
February 23, 2023 (v1)
Subject: Environment
Keywords: exercise, PM2.5, PM2.5 inhalation, predicting process, retention
In recent years, people have been increasingly concerned about air quality and pollution since a number of studies have proved that air pollution, especially PM2.5 (particulate matter), can affect human health drastically. Though the research on air quality prediction has become a mainstream research field, most of the studies focused only on the prediction of urban air quality and pollution. These studies did not predict the actual impact of these pollutants on people. According to the researchers’ best knowledge, the amount of polluted air inhaled by people and the amount of polluted air that remains inside their body are two important factors that affect their health. In order to predict the quantity of PM2.5 inhaled by people and what they have retained in their body, a process and a platform have been proposed in the current research work. In this research, the experimental process is as follows: (1) First, a personalized PM2.5 sensor is designed and developed to sense the quantit... [more]
Effects of Adding Laccase to Bacterial Consortia Degrading Heavy Oil
Xiaoli Dai, Jing Lv, Wenxia Wei, Shaohui Guo
February 23, 2023 (v1)
Subject: Environment
Keywords: bacterial consortia, bioremediation, degradation, heavy oil pollution, laccase
High-efficiency bioremediation technology for heavy oil pollution has been a popular research topic in recent years. Laccase is very promising for the remediation of heavy oil pollution because it can not only convert bio-refractory hydrocarbons into less toxic or completely harmless compounds, but also accelerate the biodegradation efficiency of heavy oil. However, there are few reports on the use of laccase to enhance the biodegradation of heavy oil. In this study, we investigated the effect of laccase on the bacterial consortia degradation of heavy oil. The degradation efficiencies of bacterial consortia and the laccase-bacterial consortia were 60.6 ± 0.1% and 68.2 ± 0.6%, respectively, and the corresponding heavy oil degradation rate constants were 0.112 day−1 and 0.198 day−1, respectively. The addition of laccase increased the heavy oil biodegradation efficiency (p < 0.05) and biodegradation rate of the bacterial consortia. Moreover, gas chromatography−mass spectrometry analysi... [more]
Biomimetics Design Optimization and Drag Reduction Analysis for Indonesia N219 Seaplanes Catamaran Float
Allessandro Utomo, Gunawan, Yanuar
February 23, 2023 (v1)
Subject: Optimization
Keywords: biomimicry, catamaran, design optimization, drag reduction, seaplane
Design optimization on the Indonesia N219 seaplane catamaran is necessary to provide better service to rural islands of Indonesia. This research aims at decreasing drag using a design based on biomimicry by imitating the hydrodynamic characteristics of sailfish (Istiophorus platypterus) for pontoon floats. The design is then validated using a numerical fluid test using ANSYS Fluent to see the reduction in drag due to the change from a conventional or Wipeline® 13000 design to a biomimetics adaptation design. Next, further optimization was carried out based on the adaptation design based on trim tests, clearance tests, and deadrise angle dimensions suitable for biomimicry designs at Froude number speeds of 0.4 to 0.7. The design results with the adaptation of biomimicry show that a change in the design with this optimization affects a drag reduction that reaches 30% of the total drag generated by the conventional design.
Study of Natural Convection of Lithium-Ion Battery Module Employing Phase Change Material
Horng-Wen Wu, Yi-Chen Ciou, Jun-Kuan Wu, De-An Huang
February 23, 2023 (v1)
Subject: Materials
Keywords: distance between cells, fin array, heat transfer, Li-ion battery, natural convection, phase change material
When the Lithium-ion battery operates at high temperature, it would bring about short circuit; if it reaches a critical temperature, it will explode. It is important to reduce its maximum temperature by appropriate heat transfer technique. When it operates without an external force for cooling, it needs natural convection technique to take away heat dissipation. Therefore, this study numerically examines three-dimensional transient natural convection of cylindrical lithium-ion batteries inside a rectangular pack with air between cylinders. The heat transfer technique in this study applies PCM (phase change material) between cylinders without or with fin array on top changing distance between cells. The results indicated that for no fin array, the package adopting the PCM could achieve the peak temperature 14.2 °C smaller than the package adopting the air. However, the package adopting the PCM with fin array vertical to the top of the package can best enhance average Nusselt number by 1... [more]
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