Chitin is the second most abundant polysaccharide,produced mainly as an industrial waste stream during crustacean processing.Chitin can be derived into chitosan through the deacetylation process.Conversion of shrimp w...Chitin is the second most abundant polysaccharide,produced mainly as an industrial waste stream during crustacean processing.Chitin can be derived into chitosan through the deacetylation process.Conversion of shrimp waste into chitosan via the deacetylation process could be considered a practical approach for shell waste remediation.In this study,chitosan’s physicochemical characteristics extracted from two types of Pacific white leg shrimp,L.vannamei’s shell(i.e.,rough and smooth),were compared with commercial chitosan.The yield,moisture,ash,solubility,water and fat binding capacity were measured.The degree of deacetylation(DDA)was calculated using FTIR,and their chemical Structure was confirmed using XRD and SEM-EDS.Both extracted chitosan showed no significant difference in yield,moisture,ash,solubility and water binding capacity but showed a significant difference with commercial chitosan.Moreover,the fat binding capacity of commercial chitosan showed the lowest percentage(408.34±0.83%)as compared to extracted chitosan(smooth shell 549.59±12.48%;rough shell 500.55±12.10%).The DDA indicated that extracted chitosan from the smooth and rough shell was considered good chitosan as compared to commercial chitosan with 84.08±1.27%,80.78±0.79%and 74.99±1.48%,respectively.Additionally,the presence of hydroxyl and amino groups from FTIR and a good crystallinity index was recorded using XRD of extracted chitosan.Based on observed characteristics,shrimp shell waste from L.vannamei can achieve chitosan standard quality as a biopolymer and highly potential to be applied in various industrial applications.展开更多
Photocatalytic methane(CH_(4))production wherein CO_(2)is reduced to CH_(4) by utilizing solar radiation energy is gaining research and industrial focus because of its environmental-friendly notion.It offers twofold a...Photocatalytic methane(CH_(4))production wherein CO_(2)is reduced to CH_(4) by utilizing solar radiation energy is gaining research and industrial focus because of its environmental-friendly notion.It offers twofold advantages:reduction in CO_(2)emission and production of artificial natural gas(methane)at the same time.In this paper,comparative energy,economic and environmental assessment of such photocatalytic methane production has been carried out between Japan and Malaysian conditions.Assumptions on the photocatalytic methane production plant and estimation of energy production,CO_(2)emission reduction,and economic indicators are made based on previous research and existing technologies.Energy analysis shows that Malaysia has a higher potential for energy production and CO_(2)emission reduction than Japan.Economic analysis reveals that the feasible reaction efficiencies of the plant in Japan and Malaysia are 8%.The slightly higher conversion efficiency in Malaysia is due to the energy price and CO_(2)tax.For the implementation of the photocatalytic methane production plant,the high energy price and CO_(2)tax will work as a driving force.展开更多
The global increase in energy demand has resulted in the depletion of non-renewable resources and caused environmental degradation.Consequently,emerging renewable technologies are a potential solution to fulfil energy...The global increase in energy demand has resulted in the depletion of non-renewable resources and caused environmental degradation.Consequently,emerging renewable technologies are a potential solution to fulfil energy demand and mitigate the effect of global warming.Low-cost solar energy harvesting technologies are most feasible technologies.Various solar cells technologies have been developed with improved overall performance and conversion effi-ciency.However,due to low cost and a wide range of applications,dye-sensitized solar cells(DSSCs)have been immensely focused on one of the most promising third-generation solar cells.The highest conversion efficiency of DSSC achieved after three decades of research is more than 14%,but the commercialization of this technology is still a challenge.In this review paper,an attempt has been made to present the comparison of different articles published,that gives the in-depth study of recent developments in various types of DSSCs based on architectural assembly and physical appearance.An overview of the limitations and challenges with their possible improvement strategies have also been discussed.This review paper concludes that appropriate selection of electrolytes dramatically affects the performance of DSSC,and quasi-solid-state electrolyte proves to be a better option.Besides,it also concludes that tandem structures are widely agreed with the approach to expand light utilization spectrum for an overall increase in its performance.However,still,the research is required,which could efficiently widen the applications of the DSSCs.展开更多
Host associated probiotics(HAPs)provide health benefits to the host when administered as dietary supplement.However,a short-term probiotics application strategy has yet to be optimized.A 90-days study was conducted to...Host associated probiotics(HAPs)provide health benefits to the host when administered as dietary supplement.However,a short-term probiotics application strategy has yet to be optimized.A 90-days study was conducted to evaluate the response of Malaysian mahseer,Tor tambroides post larvae fed with basal diet enriched HAPs for 30-days,and its response following another 60-days feeding with only basal diet.Three experimental diets(Enterococcus faecalis strain 2674(T1),Aeromonas sp.strain A8-29(T2)and E.faecalis strain FC11682(T3))were prepared by spray-coating each HAPs on a basal diet at 1×108 CFU/g feed.Differences in growth performances,whole-body proximate and fatty acid composition,muscle morphometry,and gut morphology were evaluated.Results showed that after 30 days,T3 fish produced highest growth.All HAP treatment groups showed better muscle distribution profile,improved fatty acid composition,and higher villus length,width and area,than control group.After 90 days,the growth of T3 fish was still the highest.Muscle distribution profile and villus growth were higher in HAP treatments,although only total n-6 PUFA,total MUFA,linoleic acids,and linolenic acids in HAP treated fish remained high after probiotics withdrawal.No difference in whole-body proximate composition was observed in both 30 and 90 days.Collective findings demonstrated that short-term application of HAPs at an early stage could be used to boost T.tambroides growth,with E.faecalis strain FC11682 showing the best efficacy.展开更多
Humans have relied on biomass for survival and development since the Stone Age. All aspects of human needs for materials are covered by tools, fuel, and buildings. Nowadays, metals and petroleum-based materials are wi...Humans have relied on biomass for survival and development since the Stone Age. All aspects of human needs for materials are covered by tools, fuel, and buildings. Nowadays, metals and petroleum-based materials are widely used in highly developed industries. Unfortunately, environmental contamination and the loss of natural resources have led to the reemergence of biomass resources as efficient and sustainable energy sources. Notably, simple and direct applications can no longer meet the demand for functionalization, high performance of materials and construction materials. Therefore, it is imperative to modify biomass and combine its utilisation to produce functionalization and high performance materials. For example, construction materials with superior mechanical properties and water resistance can be produced by reinforcing fibres to facilitate crosslinking. Water-oil separation or adsorption effects of hydrogels and aerogels are determined by the porosity and lightness of biomass, biocomposite conductor is prepared by chimaeric conductive material. Here, we review the approaches that have been taken to devise an environmentally friendly yet fully recyclable and sustainable functionalised biocomposites from biomass and its potential directions for future research.展开更多
Hydrogen(H_(2))is a promising renewable energy which finds wide applications as the world gears toward low-carbon economy.However,current H_(2) production via steam methane reforming of natural gas or gasification of ...Hydrogen(H_(2))is a promising renewable energy which finds wide applications as the world gears toward low-carbon economy.However,current H_(2) production via steam methane reforming of natural gas or gasification of coal are laden with high CO_(2) footprints.Recently,methane(CH_(4))pyrolysis has emerged as a potential technology to generate low-carbon H_(2) and solid carbon.In this review,the current state-of-art and recent progress of H_(2) production from CH_(4) pyrolysis are reviewed in detail.Aspects such as funda-mental mechanism and chemistry involved,effect of process parameters on the conversion efficiency and reaction kinetics for various reaction media and catalysts are elucidated and critically discussed.Temper-ature,among other factors,plays the most critical influence on the methane pyrolysis reaction.Molten metal/salt could lower the operating temperature of methane pyrolysis to<1000℃,whereas plasma technology usually operates in the regime of>1000℃.Based on the reaction kinetics,metal-based cata-lysts were more efficient in lowering the activation energy of the reaction to 29.5-88 kJ/mol from that of uncatalyzed reaction(147-420.7 kJ/mol).Besides,the current techno-economic performance of the pro-cess reveals that the levelized cost of H_(2) is directly influenced by the sales price of carbon(by-product)generated,which could offset the overall cost.Lastly,the main challenges of reactor design for efficient product separation and retrieval,as well as catalyst deactivation/poisoning need to be debottlenecked.展开更多
This study aims to formulate a steady-state mathematical model for a three-dimensional permeable enclosure(cavity)to determine the oil extraction rate using three distinct nanoparticles,SiO_(2),Al_(2)O_(3),and Fe_(2)O...This study aims to formulate a steady-state mathematical model for a three-dimensional permeable enclosure(cavity)to determine the oil extraction rate using three distinct nanoparticles,SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3),in unconventional oil reservoirs.The simulation is conducted for different parameters of volume fractions,porosities,and mass flow rates to determine the optimal oil recovery.The impact of nanoparticles on relative permeability(kr)and water is also investigated.The simulation process utilizes the finite volume ANSYS Fluent.The study results showed that when the mass flow rate at the inlet is low,oil recovery goes up.In addition,they indicated that silicon nanoparticles are better at getting oil out of the ground(i.e.,oil reservoir)than Al_(2)O_(3)and Fe_(2)O_(3).Most oil can be extracted from SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)at a rate of 97.8%,96.5%,and 88%,respectively.展开更多
Photovoltaic(PV)systems are adversely affected by partial shading and non-uniform conditions.Meanwhile,the addition of a bypass shunt diode to each PV module prevents hotspots.It also produces numerous peaks in the PV...Photovoltaic(PV)systems are adversely affected by partial shading and non-uniform conditions.Meanwhile,the addition of a bypass shunt diode to each PV module prevents hotspots.It also produces numerous peaks in the PV array’s power-voltage characteristics,thereby trapping conventional maximum power point tracking(MPPT)methods in local peaks.Swarm optimization approaches can be used to address this issue.However,these strategies have an unreasonably long convergence time.The Grey Wolf Optimizer(GWO)is a fast and more dependable optimization algorithm.This renders it a good option for MPPT of PV systems operating in varying partial shading.The conventional GWO method involves a long conversion time,large steady-state oscillations,and a high failure rate.This work attempts to address these issues by combining Cuckoo Search(CS)with the GWO algorithm to improve the MPPT performance.The results of this approach are compared with those of conventional MPPT according to GWO and MPPT methods based on perturb and observe(P&O).A comparative analysis reveals that under non-uniform operating conditions,the hybrid GWO CS(GWOCS)approach presented in this article outperforms the GWO and P&O approaches.展开更多
There are many factors that have a major influence on reducing the energy expenditure in building sector.This research aims at qualitative and quantitative assessment of those factors such as double glazed windows,ver...There are many factors that have a major influence on reducing the energy expenditure in building sector.This research aims at qualitative and quantitative assessment of those factors such as double glazed windows,ver-tical greenery systems(VGS),integrating of semi-transparent photovoltaic device with architectural design of buildings,energy saving by using heat reflecting coating,passive climate control methods,energy saving by shading,building energy performance enhancement by using optimisation technique,double skin green facade,etc.through a holistic and thematic approach.Amongst the aforesaid techniques,VGS is found the most reliable,efficient and sustainable solution.Attractive VGS can improve the urban environment,increase biodiversity,mit-igate pollution also results economic benefit of the buildings as like as energy savings and decreasing surface temperature.Four fundamental energy saving methods are used in VGS which are considered as passive energy saving mechanism.Firstly,interception of solar radiation due to the shadow risen by the vegetation;secondly,vegetation also provides thermal insulation;thirdly,plants evapotranspiration helps for evaporative cooling of building;finally,building blockage makes a variation of wind effect on building.The peak cooling load of ivy coated green building wall has been reduced by 28%.If a VGS is installed without windows and building fac-ing on west,east,south and north correspondingly,the reduction in the cooling load capacity of the building is observed to be up to 20,18,8 and 5%,respectively.Very high thermally resistive glazed areas on building envelope can be secured via thin film PV glazing and vacuum glazing products with an average U-value of 1.1 and 0.4 W/m 2 K,respectively.Energy use policies are also helpful to improve energy consumption scenario of buildings.For developing more energy-efficient,sustainable and eco-friendly buildings,these techniques might be helpful for the building designers and architects.展开更多
Increasing studies of plastisphere have raised public concern about microplastics(MPs)as vectors for pathogens,especially in aquatic environments.However,the extent to which pathogens affect human health through MPs r...Increasing studies of plastisphere have raised public concern about microplastics(MPs)as vectors for pathogens,especially in aquatic environments.However,the extent to which pathogens affect human health through MPs remains unclear,as controversies persist regarding the distinct pathogen colonization on MPs as well as the transmission routes and infection probability of MP-associated pathogens from water to humans.In this review,we critically discuss whether and how pathogens approach humans via MPs,shedding light on the potential health risks involved.Drawing on cutting-edge multidisciplinary research,we show that some MPs may facilitate the growth and long-range transmission of specific pathogens in aquatic environments,ultimately increasing the risk of infection in humans.We identify MP-and pathogen-rich settings,such as wastewater treatment plants,aquaculture farms,and swimming pools,as possible sites for human exposure to MP-associated pathogens.This review emphasizes the need for further research and targeted interventions to better understand and mitigate the potential health risks associated with MP-mediated pathogen transmission.展开更多
It is highly desirable to seek green and sustainable technologies,such as employing photo thermal effects to drive energy catalysis processes to address the high energy demand and associated environmental impacts indu...It is highly desirable to seek green and sustainable technologies,such as employing photo thermal effects to drive energy catalysis processes to address the high energy demand and associated environmental impacts induced by the current methods.The photothermocatalysis process is an emerging research area with great potential in efficiently converting solar energy through various catalytic reactions.However,achieving simultaneously high conversion efficiency,cyclability,and durability is still a daunting challenge.Thus,tremendous work is still needed to enhance solar photo thermal catalytic conversion and promote its large-scale applications.This review developed the principles of coupling solar photon and thermal fields underlying the photothermal effect,exploration of efficient nanocatalysts,development of optofluidic reactor model,and photo thermal synergistic-driven CO_(2) reduction mechanisms.The ultimate goal was to provide an effective approach that can effectively convert solar energy into photocarriers/hot-electrons and heat,and importantly,can couple them to regulate catalysis reaction pathways toward the production of value-added fuel and chemical energy.展开更多
Gynogenesis is an established technique to generate all female type offspring and this technique has been successfully induced diploid gynogens progeny in aquatic animals of fishes and crustaceans.Monosex culture of a...Gynogenesis is an established technique to generate all female type offspring and this technique has been successfully induced diploid gynogens progeny in aquatic animals of fishes and crustaceans.Monosex culture of all female shrimp and fishes were selected attribute to all female type offspring which have better size than male and help increase the market size and profitable.This article discusses on the protocol applied to produce gynogens progeny and the successful rate of gynogenesis production in fishes,molluscs and aquatic crustaceans of shrimps in general.Overall most of the UV length applied for irradiated the sperm were around 254-365 nm for(20-40 s),(20-80 s)and(5-8 s)for shrimps,254 nm,30 s for molluscs species and for fishes were around 254 nm for(1.5min)and(2-12 min)time of exposure respectively.For gynogenesis induction,the fertilized eggs were treated with cold shock,heat shock or cytochalasin-B for both shrimp and fishes gynogens technique.Fertilization rate was identified around 4.33%-19.67%in shrimp.Successful hatching rate was identified around 3.0%,14.9%-37.2%of gynogens offspring in shrimp and various percentages of hatching rates were identified from each species of fish gynogens.Overall,there is still low survival rate of gynogens produced using gynogenesis technique and further study should be carried out to improve the gynogens production.The discussed protocols serve as a guide lines for the gynogenesis technique application of all female monosex culture in the future.展开更多
Photovoltaic(PV)system’s performance is significantly affected by its orientation and tilt angle.Experimental investigation(indoor and outdoor)has been carried out to trace the variation in PV performance and electri...Photovoltaic(PV)system’s performance is significantly affected by its orientation and tilt angle.Experimental investigation(indoor and outdoor)has been carried out to trace the variation in PV performance and electrical parameters at varying tilt angles in Malaysian conditions.There were two experimental modus:1)varying module tilt under constant irradiation level,2)varying irradiation intensity at the optimum tilt set up.For the former scheme,the irradiation level was maintained at 750 W/m^(2),and for the later arrangement,the module tilt angle was varied from 0 o to 80 o by means of a single-axis tracker.Results show that under constant irradiation of 750 W/m^(2),every 5 o increase in tilt angle causes a power drop of 2.09 W at indoor and 3.45 W at outdoor.In contrast,for the same condition,efficiency decreases by 0.54%for indoor case and by 0.76%at outdoor.On the other hand,for every 100 W/m^(2)increase in irradiation,solar cell temperature rises by 7.52℃at indoor and by 5.67℃at outdoor.As of module electrical parameters,open-circuit voltage,short-circuit current,maximum power point voltage and maximum power point current drops substantially with increasing tilt angle,whereas fill factor drops rather gradually.Outdoor experimental investigation confirms that the optimum tilt angle at Malaysian conditions is 15 o and orienting a PV module this angle will maximize the sun’s energy captured and thereby enhance its performance.展开更多
During this decade,graphene which is a thin layer of carbon material along at ease with synthesis and functionalization has become a hot topic of research owing to excellent mechanical strength,very good current densi...During this decade,graphene which is a thin layer of carbon material along at ease with synthesis and functionalization has become a hot topic of research owing to excellent mechanical strength,very good current density,high thermal conductivity,superior electrical conductivity,large surface area,and good electron mobility.The research on graphene has exponentially accelerated specially when Geim and Novoselov developed and analyzed graphene.On this basis,for industrial application,researchers are exploring different techniques to produce high-quality graphene.Therefore,reviewed in this article is a brief introduction to graphene and its derivatives along with some of the methods developed to synthesize graphene and its prospective applications in both research and industry.In this work,recent advances on applications of graphene in various fields such as sensors,energy storage,energy harvesting,high-speed optoelectronics,supercapacitors,touch-based flexible screens,and organic light emitting diode displays have been summarized.展开更多
Microwave steam pyrolysis(MSP)is an innovative thermochemical approach to converting biomass into high-quality biochar using steam to improve the dielectric heating of microwave radiation.Biochar shows high fixed carb...Microwave steam pyrolysis(MSP)is an innovative thermochemical approach to converting biomass into high-quality biochar using steam to improve the dielectric heating of microwave radiation.Biochar shows high fixed carbon and carbon contents at a maximum temperature of 550℃in 10 min.The MSP achieved a heating rate of 112℃/min from 200℃to 400℃to produce biochar effectively.Furthermore,the thermal properties of biochar in microwave heating were investigated in this study to explore its potential as a microwave heat-absorbent material.Microwave is able to perform volumetric and controllable heating to the biochar.Moreover,biochar shows good microwave heat absorbency,storing and transferring heat effectively.The temperature profile of three different sizes of biochar was investigated to examine the efficiency of biochar in heat absorption from microwave radiation.It was found that the powder form of biochar showed a higher heat transfer rate of 40℃/min and a low cooling rate of 7.5℃/min.The presented results are useful for evaluating the application of biochar as a promising medium for heat storage systems.展开更多
Microwave simulation is significant in identifying a reactor design allowing the biomass to be heated and processed evenly.This study integrated the radio frequency and transient heat transfer modules to simulate the ...Microwave simulation is significant in identifying a reactor design allowing the biomass to be heated and processed evenly.This study integrated the radio frequency and transient heat transfer modules to simulate the microwave distribution and investigated the performance of microwave heating in the cavity.The simulation results were compared with the experimental findings us-ing the finite element analysis software of COMSOL MULTIPHYSICS to predict the temperature profile and electric field of microwave in the biomass(empty fruit bunch pellets).The higher temperature distribution was observed at the bottom and centre section of the empty fruit bunch pellet bed in the reactor,showing the uniqueness of microwave heating.According to the simula-tion results,the temperature profile obtained through the specific cavity geometry and dielectric properties agreed with the experimental temperature profile.The simulated temperature profile demonstrated a logarithmic increase of 120°C/min at the first 50 s followed by 50°C/min until 350 s.The experimental temperature profile showed three different heating rates before reaching 300°C,including 78.3°C/min(50-120°C),30.6°C/min(121-250°C),and 105°C/min(250-300°C).The results of this study might contribute to the improvement of microwave heating in biomass torrefaction.展开更多
The ever-present demand for energy from various application in industrial and domestic processes has led to the consumption of fossil fuel at a rapid rate with adverse effect due to global warming.This study focuses o...The ever-present demand for energy from various application in industrial and domestic processes has led to the consumption of fossil fuel at a rapid rate with adverse effect due to global warming.This study focuses on the thermal energy storage aspect intended for medium temperature applications.A novel composite A70 and PANI was prepared and characterized.The study investigates the composites thermophysical and optical properties.Differential Scanning Calorimetry and Transient Hot Bridge measured thermal storage capacity and thermal conductivity of the composite,respectively.The heat storage capacity of the composite remained stable within 4%whereas a highest rise of 11.96%in thermal conductivity was measured.The composites thermal,chemical,and physical stability were analysed from Thermogravimetric Analyser,Fourier Infrared Transform,and Scanning Electron Microscope,respectively.The composites were thermally stable up to a temperature of 250°C.No chemical reaction occurred between the nanomaterial and base PCM matrix.The microscopic visuals did not show any considerable change in the microscopic structure of the material.In the case of optical properties,the composites showed significant reduction in transmittance of solar spectrum with respect to pure A70.The maximum decrement in transmission was around~89%compared to A70.As the composite prepared were thermally stable till 250°C,hence may be utilized for solar thermal and low concentrated photovoltaic application but not limited to these.展开更多
A railroad accident on February 3,2023,led to the release and combustion of 115,580 gallons,equivalent to over 437,000 L,of vinyl chloride monomer(VCM)in East Palestine,Ohio[1].This monomer is used in polyvinyl chlori...A railroad accident on February 3,2023,led to the release and combustion of 115,580 gallons,equivalent to over 437,000 L,of vinyl chloride monomer(VCM)in East Palestine,Ohio[1].This monomer is used in polyvinyl chloride(PVC)production,and its burning produces additional toxins such as hydrochloric acid and lethal phosgene,known as a notorious chemical weapon during World War I[2].Acute exposure to these chemicals causes immediate adverse effects on local ecosystems,including the deaths of wild and farmed animals and pets.展开更多
The ongoing pandemics boost the demand for chemical disinfectants,including surface disinfectants and hand sanitizers[1].This is largely driven by increasing public health awareness and hygiene standards in public and...The ongoing pandemics boost the demand for chemical disinfectants,including surface disinfectants and hand sanitizers[1].This is largely driven by increasing public health awareness and hygiene standards in public and private settings[2].The global surface disinfectant market size in 2019 was valued at US$3.4 billion and estimated to experience a 6.0%compound annual growth rate,reaching US$5.42 billion in 2027[3].展开更多
基金funded by The Ministry of Higher Education(MOHE)Malaysia,under The Higher Institution Centre of Excellence(HICoE)Institute of Tropical Aquaculture and Fisheries(AKUATROP)Program[Vot.No.63933,JPT.S(BPKI)2000/016/018/015 Jld.3(23)and Vot.No.56050,UMT/PPPI/2-2/5 Jld.2(24)].This work was also funded by the Long-Term Research Grant Scheme 1/2018,LRGS(LRGS/2018/USM-UKM/EWS/01).
文摘Chitin is the second most abundant polysaccharide,produced mainly as an industrial waste stream during crustacean processing.Chitin can be derived into chitosan through the deacetylation process.Conversion of shrimp waste into chitosan via the deacetylation process could be considered a practical approach for shell waste remediation.In this study,chitosan’s physicochemical characteristics extracted from two types of Pacific white leg shrimp,L.vannamei’s shell(i.e.,rough and smooth),were compared with commercial chitosan.The yield,moisture,ash,solubility,water and fat binding capacity were measured.The degree of deacetylation(DDA)was calculated using FTIR,and their chemical Structure was confirmed using XRD and SEM-EDS.Both extracted chitosan showed no significant difference in yield,moisture,ash,solubility and water binding capacity but showed a significant difference with commercial chitosan.Moreover,the fat binding capacity of commercial chitosan showed the lowest percentage(408.34±0.83%)as compared to extracted chitosan(smooth shell 549.59±12.48%;rough shell 500.55±12.10%).The DDA indicated that extracted chitosan from the smooth and rough shell was considered good chitosan as compared to commercial chitosan with 84.08±1.27%,80.78±0.79%and 74.99±1.48%,respectively.Additionally,the presence of hydroxyl and amino groups from FTIR and a good crystallinity index was recorded using XRD of extracted chitosan.Based on observed characteristics,shrimp shell waste from L.vannamei can achieve chitosan standard quality as a biopolymer and highly potential to be applied in various industrial applications.
基金the support from the Kyoto University and University of Malaya double degree programme to carry out this research
文摘Photocatalytic methane(CH_(4))production wherein CO_(2)is reduced to CH_(4) by utilizing solar radiation energy is gaining research and industrial focus because of its environmental-friendly notion.It offers twofold advantages:reduction in CO_(2)emission and production of artificial natural gas(methane)at the same time.In this paper,comparative energy,economic and environmental assessment of such photocatalytic methane production has been carried out between Japan and Malaysian conditions.Assumptions on the photocatalytic methane production plant and estimation of energy production,CO_(2)emission reduction,and economic indicators are made based on previous research and existing technologies.Energy analysis shows that Malaysia has a higher potential for energy production and CO_(2)emission reduction than Japan.Economic analysis reveals that the feasible reaction efficiencies of the plant in Japan and Malaysia are 8%.The slightly higher conversion efficiency in Malaysia is due to the energy price and CO_(2)tax.For the implementation of the photocatalytic methane production plant,the high energy price and CO_(2)tax will work as a driving force.
基金Universiti Malaysia Pahang(UMP)for the financial support under Grant RDU192205 and RDU192403.
文摘The global increase in energy demand has resulted in the depletion of non-renewable resources and caused environmental degradation.Consequently,emerging renewable technologies are a potential solution to fulfil energy demand and mitigate the effect of global warming.Low-cost solar energy harvesting technologies are most feasible technologies.Various solar cells technologies have been developed with improved overall performance and conversion effi-ciency.However,due to low cost and a wide range of applications,dye-sensitized solar cells(DSSCs)have been immensely focused on one of the most promising third-generation solar cells.The highest conversion efficiency of DSSC achieved after three decades of research is more than 14%,but the commercialization of this technology is still a challenge.In this review paper,an attempt has been made to present the comparison of different articles published,that gives the in-depth study of recent developments in various types of DSSCs based on architectural assembly and physical appearance.An overview of the limitations and challenges with their possible improvement strategies have also been discussed.This review paper concludes that appropriate selection of electrolytes dramatically affects the performance of DSSC,and quasi-solid-state electrolyte proves to be a better option.Besides,it also concludes that tandem structures are widely agreed with the approach to expand light utilization spectrum for an overall increase in its performance.However,still,the research is required,which could efficiently widen the applications of the DSSCs.
基金funded by Universiti Malaysia Terengganu under the Research Intensified Grant Scheme (RIGS VOT NO 55192/5).
文摘Host associated probiotics(HAPs)provide health benefits to the host when administered as dietary supplement.However,a short-term probiotics application strategy has yet to be optimized.A 90-days study was conducted to evaluate the response of Malaysian mahseer,Tor tambroides post larvae fed with basal diet enriched HAPs for 30-days,and its response following another 60-days feeding with only basal diet.Three experimental diets(Enterococcus faecalis strain 2674(T1),Aeromonas sp.strain A8-29(T2)and E.faecalis strain FC11682(T3))were prepared by spray-coating each HAPs on a basal diet at 1×108 CFU/g feed.Differences in growth performances,whole-body proximate and fatty acid composition,muscle morphometry,and gut morphology were evaluated.Results showed that after 30 days,T3 fish produced highest growth.All HAP treatment groups showed better muscle distribution profile,improved fatty acid composition,and higher villus length,width and area,than control group.After 90 days,the growth of T3 fish was still the highest.Muscle distribution profile and villus growth were higher in HAP treatments,although only total n-6 PUFA,total MUFA,linoleic acids,and linolenic acids in HAP treated fish remained high after probiotics withdrawal.No difference in whole-body proximate composition was observed in both 30 and 90 days.Collective findings demonstrated that short-term application of HAPs at an early stage could be used to boost T.tambroides growth,with E.faecalis strain FC11682 showing the best efficacy.
基金the National Natural Science Foundation of China (No.32201491)China Postdoctoral Science Foundation (No.2021M690847)+5 种基金Natural Science Foundation of Jiangsu Province (No.BK20200775)Natural Science Foundation of the Jiangsu Higher Education Institutions of China (No.21KJB220011)Science and Technology Innovation Program of Hunan Province (No.2021RC2106)Deputy General Project of Science and Technology of Jiangsu Province (No.FZ20211507)Hunan Province Biomass-based Materials Green and Low-carbon Intelligent Manufacturing Engineering Technology Research centre (No.2022TP2033)Technology centre of Hunan Hongsen Novel Material Technology Co., Ltd. (No.HNJSZX2022290)。
文摘Humans have relied on biomass for survival and development since the Stone Age. All aspects of human needs for materials are covered by tools, fuel, and buildings. Nowadays, metals and petroleum-based materials are widely used in highly developed industries. Unfortunately, environmental contamination and the loss of natural resources have led to the reemergence of biomass resources as efficient and sustainable energy sources. Notably, simple and direct applications can no longer meet the demand for functionalization, high performance of materials and construction materials. Therefore, it is imperative to modify biomass and combine its utilisation to produce functionalization and high performance materials. For example, construction materials with superior mechanical properties and water resistance can be produced by reinforcing fibres to facilitate crosslinking. Water-oil separation or adsorption effects of hydrogels and aerogels are determined by the porosity and lightness of biomass, biocomposite conductor is prepared by chimaeric conductive material. Here, we review the approaches that have been taken to devise an environmentally friendly yet fully recyclable and sustainable functionalised biocomposites from biomass and its potential directions for future research.
基金support by the Education University of Hong Kong to perform this project under International Grant(UMT/International Grant/2020/53376).
文摘Hydrogen(H_(2))is a promising renewable energy which finds wide applications as the world gears toward low-carbon economy.However,current H_(2) production via steam methane reforming of natural gas or gasification of coal are laden with high CO_(2) footprints.Recently,methane(CH_(4))pyrolysis has emerged as a potential technology to generate low-carbon H_(2) and solid carbon.In this review,the current state-of-art and recent progress of H_(2) production from CH_(4) pyrolysis are reviewed in detail.Aspects such as funda-mental mechanism and chemistry involved,effect of process parameters on the conversion efficiency and reaction kinetics for various reaction media and catalysts are elucidated and critically discussed.Temper-ature,among other factors,plays the most critical influence on the methane pyrolysis reaction.Molten metal/salt could lower the operating temperature of methane pyrolysis to<1000℃,whereas plasma technology usually operates in the regime of>1000℃.Based on the reaction kinetics,metal-based cata-lysts were more efficient in lowering the activation energy of the reaction to 29.5-88 kJ/mol from that of uncatalyzed reaction(147-420.7 kJ/mol).Besides,the current techno-economic performance of the pro-cess reveals that the levelized cost of H_(2) is directly influenced by the sales price of carbon(by-product)generated,which could offset the overall cost.Lastly,the main challenges of reactor design for efficient product separation and retrieval,as well as catalyst deactivation/poisoning need to be debottlenecked.
基金The APC of this article is covered by Research Grant YUTP 015LCO-526。
文摘This study aims to formulate a steady-state mathematical model for a three-dimensional permeable enclosure(cavity)to determine the oil extraction rate using three distinct nanoparticles,SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3),in unconventional oil reservoirs.The simulation is conducted for different parameters of volume fractions,porosities,and mass flow rates to determine the optimal oil recovery.The impact of nanoparticles on relative permeability(kr)and water is also investigated.The simulation process utilizes the finite volume ANSYS Fluent.The study results showed that when the mass flow rate at the inlet is low,oil recovery goes up.In addition,they indicated that silicon nanoparticles are better at getting oil out of the ground(i.e.,oil reservoir)than Al_(2)O_(3)and Fe_(2)O_(3).Most oil can be extracted from SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)at a rate of 97.8%,96.5%,and 88%,respectively.
文摘Photovoltaic(PV)systems are adversely affected by partial shading and non-uniform conditions.Meanwhile,the addition of a bypass shunt diode to each PV module prevents hotspots.It also produces numerous peaks in the PV array’s power-voltage characteristics,thereby trapping conventional maximum power point tracking(MPPT)methods in local peaks.Swarm optimization approaches can be used to address this issue.However,these strategies have an unreasonably long convergence time.The Grey Wolf Optimizer(GWO)is a fast and more dependable optimization algorithm.This renders it a good option for MPPT of PV systems operating in varying partial shading.The conventional GWO method involves a long conversion time,large steady-state oscillations,and a high failure rate.This work attempts to address these issues by combining Cuckoo Search(CS)with the GWO algorithm to improve the MPPT performance.The results of this approach are compared with those of conventional MPPT according to GWO and MPPT methods based on perturb and observe(P&O).A comparative analysis reveals that under non-uniform operating conditions,the hybrid GWO CS(GWOCS)approach presented in this article outperforms the GWO and P&O approaches.
基金Authors would like to acknowledge the financial support from Uni-versity of Malaya,Impact orientated Interdisciplinary Research Grant(Project:IIRG015B-2019)to carry out this research.
文摘There are many factors that have a major influence on reducing the energy expenditure in building sector.This research aims at qualitative and quantitative assessment of those factors such as double glazed windows,ver-tical greenery systems(VGS),integrating of semi-transparent photovoltaic device with architectural design of buildings,energy saving by using heat reflecting coating,passive climate control methods,energy saving by shading,building energy performance enhancement by using optimisation technique,double skin green facade,etc.through a holistic and thematic approach.Amongst the aforesaid techniques,VGS is found the most reliable,efficient and sustainable solution.Attractive VGS can improve the urban environment,increase biodiversity,mit-igate pollution also results economic benefit of the buildings as like as energy savings and decreasing surface temperature.Four fundamental energy saving methods are used in VGS which are considered as passive energy saving mechanism.Firstly,interception of solar radiation due to the shadow risen by the vegetation;secondly,vegetation also provides thermal insulation;thirdly,plants evapotranspiration helps for evaporative cooling of building;finally,building blockage makes a variation of wind effect on building.The peak cooling load of ivy coated green building wall has been reduced by 28%.If a VGS is installed without windows and building fac-ing on west,east,south and north correspondingly,the reduction in the cooling load capacity of the building is observed to be up to 20,18,8 and 5%,respectively.Very high thermally resistive glazed areas on building envelope can be secured via thin film PV glazing and vacuum glazing products with an average U-value of 1.1 and 0.4 W/m 2 K,respectively.Energy use policies are also helpful to improve energy consumption scenario of buildings.For developing more energy-efficient,sustainable and eco-friendly buildings,these techniques might be helpful for the building designers and architects.
基金supported by the National Natural Science Foundation of China(U2032201,52025102).
文摘Increasing studies of plastisphere have raised public concern about microplastics(MPs)as vectors for pathogens,especially in aquatic environments.However,the extent to which pathogens affect human health through MPs remains unclear,as controversies persist regarding the distinct pathogen colonization on MPs as well as the transmission routes and infection probability of MP-associated pathogens from water to humans.In this review,we critically discuss whether and how pathogens approach humans via MPs,shedding light on the potential health risks involved.Drawing on cutting-edge multidisciplinary research,we show that some MPs may facilitate the growth and long-range transmission of specific pathogens in aquatic environments,ultimately increasing the risk of infection in humans.We identify MP-and pathogen-rich settings,such as wastewater treatment plants,aquaculture farms,and swimming pools,as possible sites for human exposure to MP-associated pathogens.This review emphasizes the need for further research and targeted interventions to better understand and mitigate the potential health risks associated with MP-mediated pathogen transmission.
基金financially supported by the China National Key Research and Development Plan Project(No.2018YFA0702300)the National Natural Science Foundation of China(No.52227813)。
文摘It is highly desirable to seek green and sustainable technologies,such as employing photo thermal effects to drive energy catalysis processes to address the high energy demand and associated environmental impacts induced by the current methods.The photothermocatalysis process is an emerging research area with great potential in efficiently converting solar energy through various catalytic reactions.However,achieving simultaneously high conversion efficiency,cyclability,and durability is still a daunting challenge.Thus,tremendous work is still needed to enhance solar photo thermal catalytic conversion and promote its large-scale applications.This review developed the principles of coupling solar photon and thermal fields underlying the photothermal effect,exploration of efficient nanocatalysts,development of optofluidic reactor model,and photo thermal synergistic-driven CO_(2) reduction mechanisms.The ultimate goal was to provide an effective approach that can effectively convert solar energy into photocarriers/hot-electrons and heat,and importantly,can couple them to regulate catalysis reaction pathways toward the production of value-added fuel and chemical energy.
文摘Gynogenesis is an established technique to generate all female type offspring and this technique has been successfully induced diploid gynogens progeny in aquatic animals of fishes and crustaceans.Monosex culture of all female shrimp and fishes were selected attribute to all female type offspring which have better size than male and help increase the market size and profitable.This article discusses on the protocol applied to produce gynogens progeny and the successful rate of gynogenesis production in fishes,molluscs and aquatic crustaceans of shrimps in general.Overall most of the UV length applied for irradiated the sperm were around 254-365 nm for(20-40 s),(20-80 s)and(5-8 s)for shrimps,254 nm,30 s for molluscs species and for fishes were around 254 nm for(1.5min)and(2-12 min)time of exposure respectively.For gynogenesis induction,the fertilized eggs were treated with cold shock,heat shock or cytochalasin-B for both shrimp and fishes gynogens technique.Fertilization rate was identified around 4.33%-19.67%in shrimp.Successful hatching rate was identified around 3.0%,14.9%-37.2%of gynogens offspring in shrimp and various percentages of hatching rates were identified from each species of fish gynogens.Overall,there is still low survival rate of gynogens produced using gynogenesis technique and further study should be carried out to improve the gynogens production.The discussed protocols serve as a guide lines for the gynogenesis technique application of all female monosex culture in the future.
基金The authors would like to acknowledge the financial support from University of Malaya,Impact Oriented Interdisciplinary Research Grant(Project:IIRG015B-2019)to carry out this research.
文摘Photovoltaic(PV)system’s performance is significantly affected by its orientation and tilt angle.Experimental investigation(indoor and outdoor)has been carried out to trace the variation in PV performance and electrical parameters at varying tilt angles in Malaysian conditions.There were two experimental modus:1)varying module tilt under constant irradiation level,2)varying irradiation intensity at the optimum tilt set up.For the former scheme,the irradiation level was maintained at 750 W/m^(2),and for the later arrangement,the module tilt angle was varied from 0 o to 80 o by means of a single-axis tracker.Results show that under constant irradiation of 750 W/m^(2),every 5 o increase in tilt angle causes a power drop of 2.09 W at indoor and 3.45 W at outdoor.In contrast,for the same condition,efficiency decreases by 0.54%for indoor case and by 0.76%at outdoor.On the other hand,for every 100 W/m^(2)increase in irradiation,solar cell temperature rises by 7.52℃at indoor and by 5.67℃at outdoor.As of module electrical parameters,open-circuit voltage,short-circuit current,maximum power point voltage and maximum power point current drops substantially with increasing tilt angle,whereas fill factor drops rather gradually.Outdoor experimental investigation confirms that the optimum tilt angle at Malaysian conditions is 15 o and orienting a PV module this angle will maximize the sun’s energy captured and thereby enhance its performance.
基金providing the research facilitiesandIIRG grantIIRG007C-19IISS and SATU Joint grant ST031-2021.
文摘During this decade,graphene which is a thin layer of carbon material along at ease with synthesis and functionalization has become a hot topic of research owing to excellent mechanical strength,very good current density,high thermal conductivity,superior electrical conductivity,large surface area,and good electron mobility.The research on graphene has exponentially accelerated specially when Geim and Novoselov developed and analyzed graphene.On this basis,for industrial application,researchers are exploring different techniques to produce high-quality graphene.Therefore,reviewed in this article is a brief introduction to graphene and its derivatives along with some of the methods developed to synthesize graphene and its prospective applications in both research and industry.In this work,recent advances on applications of graphene in various fields such as sensors,energy storage,energy harvesting,high-speed optoelectronics,supercapacitors,touch-based flexible screens,and organic light emitting diode displays have been summarized.
基金support provided by the University College of Technology Sarawak for conducting the research under the University Grant Scheme:(No.UCTS/RESEARCH/2/2020/07).
文摘Microwave steam pyrolysis(MSP)is an innovative thermochemical approach to converting biomass into high-quality biochar using steam to improve the dielectric heating of microwave radiation.Biochar shows high fixed carbon and carbon contents at a maximum temperature of 550℃in 10 min.The MSP achieved a heating rate of 112℃/min from 200℃to 400℃to produce biochar effectively.Furthermore,the thermal properties of biochar in microwave heating were investigated in this study to explore its potential as a microwave heat-absorbent material.Microwave is able to perform volumetric and controllable heating to the biochar.Moreover,biochar shows good microwave heat absorbency,storing and transferring heat effectively.The temperature profile of three different sizes of biochar was investigated to examine the efficiency of biochar in heat absorption from microwave radiation.It was found that the powder form of biochar showed a higher heat transfer rate of 40℃/min and a low cooling rate of 7.5℃/min.The presented results are useful for evaluating the application of biochar as a promising medium for heat storage systems.
基金Universiti Malaysia Terengganu,Universiti Teknologi PETRONAS,Universiti Malaysia Pahang and University of Technology Sarawak for financial support under Matching Grant(UMT/CRIM/2-2/25/Jld.8(58),Vot 53381)and(UCTS/RESEARCH/<2/2021/06>(01)),(UCTS/RESEARCH/<2/2020/06>(01))to perform this projectsupport by the Ministry of Higher Education,Malaysia under the Higher Institution Centre of Excellence(HICoE),Institute of Tropical Aquaculture and Fisheries(AKUATROP)program(Vot.No.63933&Vot.No.56051,UMT/CRIM/2-2/5 Jilid 2(10)).
文摘Microwave simulation is significant in identifying a reactor design allowing the biomass to be heated and processed evenly.This study integrated the radio frequency and transient heat transfer modules to simulate the microwave distribution and investigated the performance of microwave heating in the cavity.The simulation results were compared with the experimental findings us-ing the finite element analysis software of COMSOL MULTIPHYSICS to predict the temperature profile and electric field of microwave in the biomass(empty fruit bunch pellets).The higher temperature distribution was observed at the bottom and centre section of the empty fruit bunch pellet bed in the reactor,showing the uniqueness of microwave heating.According to the simula-tion results,the temperature profile obtained through the specific cavity geometry and dielectric properties agreed with the experimental temperature profile.The simulated temperature profile demonstrated a logarithmic increase of 120°C/min at the first 50 s followed by 50°C/min until 350 s.The experimental temperature profile showed three different heating rates before reaching 300°C,including 78.3°C/min(50-120°C),30.6°C/min(121-250°C),and 105°C/min(250-300°C).The results of this study might contribute to the improvement of microwave heating in biomass torrefaction.
基金One of the author(A K Pandey)duly acknowledges the financial assistance through Sunway University collaborative research fund:MRU 2019(STR-RMF-MRU-004-2019)for carrying out this researchThe authors thank the technical and financial assistance of UM Power Energy Dedicated Advanced center(UMPEDAC)and the Higher Institution center of Excellence(HICoE)Program Research Grant,UMPEDAC-2018(MOHE HICOE-UMPEDAC)+1 种基金Ministry of Education MalaysiaTOP100UMPEDAC and RU012-2019,University of Malaya.
文摘The ever-present demand for energy from various application in industrial and domestic processes has led to the consumption of fossil fuel at a rapid rate with adverse effect due to global warming.This study focuses on the thermal energy storage aspect intended for medium temperature applications.A novel composite A70 and PANI was prepared and characterized.The study investigates the composites thermophysical and optical properties.Differential Scanning Calorimetry and Transient Hot Bridge measured thermal storage capacity and thermal conductivity of the composite,respectively.The heat storage capacity of the composite remained stable within 4%whereas a highest rise of 11.96%in thermal conductivity was measured.The composites thermal,chemical,and physical stability were analysed from Thermogravimetric Analyser,Fourier Infrared Transform,and Scanning Electron Microscope,respectively.The composites were thermally stable up to a temperature of 250°C.No chemical reaction occurred between the nanomaterial and base PCM matrix.The microscopic visuals did not show any considerable change in the microscopic structure of the material.In the case of optical properties,the composites showed significant reduction in transmittance of solar spectrum with respect to pure A70.The maximum decrement in transmission was around~89%compared to A70.As the composite prepared were thermally stable till 250°C,hence may be utilized for solar thermal and low concentrated photovoltaic application but not limited to these.
文摘A railroad accident on February 3,2023,led to the release and combustion of 115,580 gallons,equivalent to over 437,000 L,of vinyl chloride monomer(VCM)in East Palestine,Ohio[1].This monomer is used in polyvinyl chloride(PVC)production,and its burning produces additional toxins such as hydrochloric acid and lethal phosgene,known as a notorious chemical weapon during World War I[2].Acute exposure to these chemicals causes immediate adverse effects on local ecosystems,including the deaths of wild and farmed animals and pets.
文摘The ongoing pandemics boost the demand for chemical disinfectants,including surface disinfectants and hand sanitizers[1].This is largely driven by increasing public health awareness and hygiene standards in public and private settings[2].The global surface disinfectant market size in 2019 was valued at US$3.4 billion and estimated to experience a 6.0%compound annual growth rate,reaching US$5.42 billion in 2027[3].
