Low Production Efficiency Research Articles

Methylmercury cycling in the Bohai Sea and Yellow Sea: Reasons for the low system efficiency of methylmercury production

Coastal seas contribute the majority of human methylmercury (MeHg) exposure via marine fisheries. The terrestrial area surrounding the Bohai Sea and Yellow Sea (BS and YS) is one of the mercury (Hg) emission “hot spots” in the world, resulting in high concentrations of Hg in BS and YS seawater in comparison to other marine systems. However, comparable or even lower Hg levels were detected in seafood from the BS and YS than other coastal regions around the word, suggesting a low system bioaccumulation of Hg. Reasoning a low system efficiency of MeHg production (represented by MeHg/THg (total Hg) in seawater) may be present in these two systems, seven cruises were conducted in the BS and YS to test this hypothesis. MeHg/THg ratios in BS and YS seawater were found to be lower than that in most coastal systems, indicating that the system efficiency of MeHg production is relatively lower in the BS and YS. The low system efficiency of MeHg production reduces the risk of Hg in the BS and YS with high Hg discharge intensity. By measuring in situ production and degradation of MeHg using double stable isotope addition method, and MeHg discharge flux from various sources and its exchange at various interfaces, the budgets of MeHg in the BS and YS were estimated. The results indicate that in situ methylation and demethylation are the major source and sink of MeHg in the BS and YS. By comparing the potential controlling processes and environmental parameters for MeHg/THg in the BS and YS with the other coastal seas, estuaries and bays, lower transport efficiency of inorganic Hg from water column to the sediment, slower methylation of Hg, and rapid demethylation of MeHg were identified to be major reasons for the low system efficiency of MeHg production in the BS and YS. This study highlights the necessity of monitoring the system efficiency of MeHg production, associated processes, and controlling parameters to evaluate the efficiency of reducing Hg emissions in China as well as the other countries.

Efficient Proton Transfer and Charge Separation within Covalent Organic Frameworks via Hydrogen-Bonding Network to Boost H2O2 Photosynthesis.

Photocatalytic synthesis based on the oxygen reduction reaction (ORR) has shown great promise for H2O2 production. However, the low activity and selectivity of 2e- ORR result in a fairly low efficiency of H2O2 production. Herein, we propose a strategy to enhance the proton-coupled electron transfer (PCET) process in covalent organic frameworks (COFs), thereby significantly boosting H2O2 photosynthesis. We demonstrated that the construction of a hydrogen-bonding network, achieved by anchoring the H3PO4 molecular network on COF nanochannels, can greatly improve both proton conductivity and photogenerated charge separation efficiency of COFs. Thus, COF@H3PO4 exhibited superior photocatalytic performance in generating H2O2 without sacrificial agents, with a solar-to-chemical conversion efficiency as high as 0.69%. Results indicated that a much more localized spatial distribution of energy band charge density on COF@H3PO4 led to efficient charge separation, and the small energy barrier of the rate-limiting step from *OOH to H2O2 endowed COF@H3PO4 with higher 2e- ORR selectivity.

Water-induced controllable deswelling strategy enabled rapid fabrication of transparent cellulose film for plastics replacement

Plastic pollution has posed significant impacts on the ecosystem. While biodegradable transparent cellulose films are considered ideal alternatives, they still grapple with issues of high energy consumption and low production efficiency. In this study, we proposed a water-induced fiber deswelling strategy to expedite the fabrication of transparent cellulose films from wood pulp. Raw cellulose fibers were firstly disintegrated into micro-sized fibers via cold alkali swelling and mild mechanical blending. Subsequently, water was introduced to govern the swelling and aggregation behavior of these treated cellulose fibers, reducing their water retention and facilitating the rapid preparation of cellulose films. By regulating the amount of water added, cellulose film can be prepared within 1 min using vacuum filtration. Furthermore, the resulting film exhibits good wet strength, surpassing most previously reported cellulose-based films, with a wet strength exceeding 30 MPa and a wet strength retention of up to 65.7 %. With these advantageous features, the cellulose film was demonstrated for packaging and fruits preservation, showing a great potential to replace conventional plastics in the packaging applications. In addition, the life cycle environmental impacts of 1.0 kg cellulose film production (cradle-to-gate system boundary) were 12.63 kg CO2-eq, 0.04 kg SO2-eq, and 397 MJ energy use.

Study on the effect of 1.4-butynediol on the performance of electroplated diamond wire saw

In response to the problems of low production efficiency and short service life of electroplated diamond wire saws used in the photovoltaic industry, in order to improve the performance of electroplated diamond wire saws, electroplating solutions with different mass fractions of 1.4-butynediol (0.1 g/L, 0.3 g/L, 0.5 g/L) were prepared by using electroplating methods. Nickel coatings were obtained through customized electroplating tanks, and electroplated diamond wire saws were prepared through electroplating processes. The effect of 1.4-butynediol content (mass fraction) in electroplating solution on the performance of diamond wire saws was studied. A scanning electron microscope was used to observe the microstructure of the coating surface and wire saw section, and the hardness, tensile strength, and wear of the coating with different concentrations of 1.4-butynediol were measured. The results show that among the three ratios, when the mass fraction of 1.4-butynediol is 0.3 g/L, the nickel coating has the best bonding with the metal matrix, the wire saw performance is the best, the coating hardness is the highest (427 MPa), and the wire saw has the least wear (0.092 g).

Digital twin-driven smelting process management method for converter steelmaking

AbstractThe converter is an indispensable key equipment in the steel manufacturing industry. With the increasing demand for high-quality steel, there is an increasing demand for monitoring and controlling the status of the converter during the smelting process. Compared to other manufacturing industries, such as food processing and textile, converter steelmaking requires a larger keep-out zone due to its ultra-high temperatures and harsh smelting environment. This makes it difficult for personnel to fully understand, analyze, and manage the smelting process, resulting in low production efficiency and the inability to achieve consistently high-quality results. Aiming at the low virtual visualization level and insufficient monitoring ability of the converter steelmaking process, a process management method based on digital twin technology is proposed. Firstly, a digital twin system framework for full-process monitoring of converter steelmaking is proposed based on the analysis of the process characteristics of converter steelmaking. The proposed framework provides critical enabling technologies such as point cloud-based digital twin model construction, visual display, and steel endpoint analysis and prediction, to support full-process, high-fidelity intelligent monitoring. After conducting experiments, a digital twin-driven smelting process management system was developed to manage the entire smelting process. The system has proven to be effective as it increased the monthly production capacity by 77.7%. The waste of smelting materials has also been greatly reduced from 34% without the system to 7.8% with the system. Based on these results, it is evident that this system significantly enhances smelting efficiency and reduces both the costs and waste associated with the process.

Influence of temperature on the behaviour and physiology of Atlantic salmon (Salmo Salar) on a commercial farm

Commercial Atlantic salmon (Salmo salar) farms face challenges under climate change, as rising sea temperatures and higher variability in weather patterns can lead to thermal stress events, compromising fish health, and resulting in lower production efficiency. Temperature plays a critical role in influencing the physiological and behavioural response of salmon under stressful conditions and effective farm management requires a nuanced comprehension of its function to adjust farming practices and minimize further stress. Two types of biologgers, measuring external acceleration, depth, heart rate, and temperature were surgically implanted for 245 days to explore the effects of the thermal response of Atlantic salmon during a standard production cycle. Apparent heart rate scope and Arrhenius breakpoint temperature were used to estimate the optimal temperature and both methods resulted in an estimate of 12.7 °C. There was a reduction in apparent heart rate scope at temperatures below 2 °C and >19 °C suggesting proximity to limits of thermal stress. The use of biologgers facilitates direct observations in commercial operations, providing essential information for aquaculture management. These findings contribute to a holistic understanding of the effect of temperature influencing Atlantic salmon physiology and behaviour on aquaculture farms, bridging the gap between controlled laboratory studies and real-world commercial operations.

Recent Advances and Challenges in Anion Exchange Membranes Development/Application for Water Electrolysis: A Review.

In recent years, anion exchange membranes (AEMs) have aroused widespread interest in hydrogen production via water electrolysis using renewable energy sources. The two current commercial low-temperature water electrolysis technologies used are alkaline water electrolysis (AWE) and proton exchange membrane (PEM) water electrolysis. The AWE technology exhibited the advantages of high stability and increased cost-effectiveness with low hydrogen production efficiency. In contrast, PEM water electrolysis exhibited high hydrogen efficiency with low stability and cost-effectiveness, respectively. Unfortunately, the major challenges that AEMs, as well as the corresponding ion transportation membranes, including alkaline hydrogen separator and proton exchange membranes, still face are hydrogen production efficiency, long-term stability, and cost-effectiveness under working conditions, which exhibited critical issues that need to be addressed as a top priority. This review comprehensively presented research progress on AEMs in recent years, providing a thorough understanding of academic studies and industrial applications. It focused on analyzing the chemical structure of polymers and the performance of AEMs and established the relationship between the structure and efficiency of the membranes. This review aimed to identify approaches for improving AEM ion conductivity and alkaline stability. Additionally, future research directions for the commercialization of anion exchange membranes were discussed based on the analysis and assessment of the current applications of AEMs in patents.

Integrating Machine Availability and Preventive Maintenance to Improve Productive Efficiency in a Manufacturing Industry

One of the major problems existing in manufacturing industries is low productive efficiency and high frequencies of machine breakdown or downtime. However, equipment maintenance is momentous for improving productive efficiency, methods of integrating preventive maintenance (PM) and Machine availability into improving productive efficiency in manufacturing industries has attracted considerable attention. This work showcased a strategic process improvement plan that can be used to improve production process with low productive efficiency. Lean Six Sigma (LSS) is used as the method for implementation of a successful process improvement. A case study was used to show how a successful implementation of the Lean Six Sigma Define, Measure, Analyze, Improve and Control (DMAIC) approach was implemented, how statistical analysis can be used to identify defects in products, and they were significantly improved. The Study is performed by conducting a qualitative and quantitative analysis using structured questionnaires, surveys, journals with the case a study that boasts of about 600 employees. Investigations showed that an average of 68% contributing to 79% productive efficiency apparently. However, the attempts of the decreasing downtime events and improving efficiency were based on scheduled maintenance checklist plan that is supported by the overall equipment effectiveness (OEE) benchmark as an indicator for affirming improvements. The linear regression model highlighted significant relationship between machine availability and productive efficiency. Proposed solutions using statistical analysis focused on sustainability, introducing a measurement model based on DMAIC criteria that demonstrated a significant improvement of 20% in machine availability, 44.3% in quality, 29.9% in productive efficiency and 57.4% OEE of the targeted case study. The research affirmed Lean Six Sigma (LSS) as a sustainable solution for reducing defects for quality issues, and maximizing efficiency in manufacturing industries, hence, emphasizing on resource optimization and continuous improvement in various study variables. Findings shows that Lean Six Sigma (LSS) as a methodology, is a catalyst for positive change, hence, improving machine performance, and customer satisfaction.

Optimization design and experiment of double-helix total mixed rations preparation mixer for silage straw feed

Aiming at the problems of uneven mixing and low production efficiency of domestic silage mixer, a double- helix TMR (Total Mixed Rations) preparation mixer for silage straw feed was designed to replace the traditional vertical single-helix mixer. The performance tests and parameter optimization were carried out on this preparation machine. By analyzing the mixing process and mechanism of the diets in the mixing chamber, the key factors affecting the mixing performance and the range were determined. It was found that the greater the stirring speed of the churn, the greater the angle of material lift, the more conducive to improving the material lifting capacity of the churn device. The mixing characteristics of the preparation machine and the movement of material were numerically simulated using EDEM simulation software, and the mixing effect of the preparation machine was verified. The three-factor and five-level CCD center combination orthogonal rotary test in the prototype was carried out with stirring speed of the churn, mixing time and filling coefficient as influencing factors, mixing uniformity, roughage particle size and ton material energy consumption as evaluation indexes. The test results showed that the contribution of each factor to the mixing uniformity in descending order was filling coefficient, stirring speed and mixing time, to the roughage particle size was stirring speed, mixing time and filling coefficient, and to the ton material energy consumption was filling coefficient, mixing time and stirring speed. The optimal working parameters for mixing performance by comprehensive optimization could be concluded as stirring speed of 48.59 r/min, mixing time of 14.98 min, and filling coefficient of 70%. In addition, the mixing uniformity, roughage particle size and ton material energy consumption were obtained as 91.11%, 72.13% and 2.99 kW·h/t. The relative error for all evaluation indexes between the experimental results with round parameter combination and the predicted value was verified to be less than 3%. It can be seen the double-helix TMR preparation mixer can meet the demand for efficient mixing of silage straw feed, which obviously provides data reference and technical support for the design and selection of operating parameters of TMR preparation machines.

Strategies to Improve the Activity of Silver–loaded Calcium Titanate Crystal Photocatalyst for Photocatalytic Reduction of Carbon Dioxide with Water

AbstractThe rapid increase of carbon dioxide (CO2) in the atmosphere has sparked a global enthusiasm for carbon recycling. Photocatalytic CO2 reduction with water into carbon–containing products has attracted much attention since it can convert solar energy to the chemical potential of the products and CO2 to valuable compounds at the same time. One of the main products in the photocatalytic reaction system is carbon monoxide (CO), a useful compound for the one‐carbon chemistry and related ones. The current shortage of this system is the low production efficiency, demanding us to improve the activity of the photocatalyst. In this perspective article, by taking a calcium titanate (CaTiO3, CTO) photocatalyst with silver cocatalyst (Ag/CTO) and so on as examples that can promote the selective photocatalytic CO2 reduction with water, we shortly review some strategies to improve the photocatalytic activity such as fabrication of well–structured crystal photocatalysts, development of the surface property and cocatalyst, improvement of surface CO2 adsorption, and improvement of photoabsorption. These concepts will be widely applied and contribute to further development of photocatalytic systems.

A gravity-induced desalination technology effectively improving the freshwater production efficiency of freeze desalination

Low desalination efficiency and water production efficiency limit the commercial application of freeze desalination (FD) technology. In this study, three freezing temperatures were set to carry out single-stage progressive freezing desalination of brackish water in southern Xinjiang, China. The ice were melted using conventional methods and gravity-induced desalination (GD), and the salt migration law during the icing and melting process was studied. The effect of GD technology on the improvement of the output of frozen desalinated produced water was quantitatively analyzed using scenario simulation. Experimental results showed that salts accumulated towards concentrated water during FD process. The ice total dissolved solids (TDS) increased with decreasing freezing temperature, which was linearly and positively correlated with the raw water TDS. GD efficiency was significantly affected by the salt concentration of ice crystals. In the first stage (the first 450 mL), ice-melt water was salt explosive dissolution, with salt drained mass accounted for more than 85% of the total salt mass. During GD process, exponential decay of ice-melt water TDS (TDSI) was observed with increasing ice-melt water amount. Through the simulation of the two exponential equation scenarios, it was found that Scenario II (mixed water TDSI as the target value) had significantly higher water yield and production rate than Scenario I (TDSI as the target value), with an increase of more than 23%. The algebraic relationship between TDSI of mixed water and the amount of ice-melt water was derived. GD technology can effectively improve the freshwater output efficiency of the FD process, which is manifested by the fact that the ice crystals of the FD process cannot produce freshwater using conventional melting. Scenario II can produce freshwater as high as 69.83% of the total amount of the GD ice-melt water. The GD technology performed increased multiplicatively in WPdv (decrease in water production) and WPRdv (decrease in water production rate) when the TDSI of the mixed water demanded by the user was low. When FD and GD are combined to desalinate salt water, lowering the freezing temperature can significantly increase the freshwater yield, breaking the limitation of freezing temperature for FD. Therefore, an automated, energy-saving freeze desalination-gravity desalination device capable of realizing the collection of the product water according to the users' needs was conceptualized. This study provides new ideas and algorithms for accurately assessing the efficiency of water production in the combined desalination of saltwater by FD and GD.

Research on productivity of stimulated natural gas hydrate reservoir

Natural gas hydrate (NGH) is a prospective clean energy. Conventional development method of the NGH reservoir by pressure drop in vertical well faces the problems of limited stimulated reservoir volume, low production efficiency, and low conductivity. At present, pressure drop production in various well types and stimulation treatments such as hydraulic fracturing in fracable NGH reservoirs have become the focus. The effects of pressure drop production in vertical well, horizontal well, radial wells, and hydraulic fracturing in vertical and horizontal wells in NGH reservoirs were simulated with HydrateResSim. We simulated the productivity of NGH reservoir for 1000 days with several types of development mode. The productivity is highest in horizontal well staged fracturing (5 stages), followed by pressure drop production in horizontal well, fractured vertical well (single fracture), and radial well (16 holes). The worst effect is obtained through production by pressure drop in single vertical well. The optimal effects were obtained with the fracture spacing of 58 m, the fracture half-length of 100 m and the conductivity of 30 μm2 cm. The horizontal well multi-cluster fracturing significantly enlarges the stimulated area and provides channels for gas migration and enhances productivity.

Research Progress on the Manufacturing of Screw-Shaped Parts in Screw Compressors

Screw compressors are highly researched and developed prospects in industry because of their long service life, high transmission efficiency, low footprint and low vibration. As the key core part of the screw compressor, the screw is a typical, long-shaft, complex profile part. Its processing method, manufacturing accuracy and quality have an extremely important impact on the performance of the whole screw compressor. In this work, the research progress on the manufacturing of screw-shaped parts in screw compressors is summarised from the aspects of the cutting process, solid plastic forming, casting and additive manufacturing. The merits and demerits of these manufacturing processes are provided and discussed, which is conducive to the development of the high-efficiency, precise and high-performance forming process of screw-shaped parts. Additionally, a novel forming process is proposed to solve the problems of serious material waste and low production efficiency for the screw-shaped parts. In the proposed process, the semi-solid spherical grain is firstly prepared by radial forging and the isothermal treatment of long-shaft raw materials. The large strain energy can be stored in the bar by the radial forging of long-shaft raw materials, which is used to induce the generation of semi-solid spherical grains with the assistance of the isothermal procedure. After that, the screw is fabricated by the high-efficiency semi-solid closed extrusion process.

Enhanced humification via lignocellulosic pretreatment in remediation of agricultural solid waste

Stover and manure are the main solid waste in agricultural industry. The generation of stover and manure could lead to serious environmental pollution if not handled properly. Composting is the potential greener solution to remediate and reduce agricultural solid waste, through which stover and manure could be remediated and converted into organic fertilizer, but the long composting period and low efficiency of humic substance production are the key constraints in such remediation approach. In this study, we explore the effect of lignocellulose selective removal on composting by performing chemical pretreatment on agricultural waste followed by utilization of biochar to assist in the remediation by co-composting treatment and reveal the impacts of different lignocellulose component on organic fertilizer production. Aiming to discover the key factors that influence humification during composting process and improve the composting quality as well as comprehensive utilization of agricultural solid waste. The results demonstrated that the removal of selective lignin or hemicellulose led to the shift of abundances lignocellulose-degrading bacteria, which in turn accelerated the degradation of lignocellulose by almost 51.2%. The process also facilitated the remediation of organic waste via humification and increased the humic acid level and HA/FA ratio in just 22 days. The richness of media relies on their lignocellulose content, which is negatively correlated with total nitrogen content, humic acid (HA) content, germination index (GI), and pH, but positively correlated with fulvic acid (FA) and total organic carbon (TOC). The work provides a potential cost effective and efficient framework for agricultural solid waste remediation and reduction.

Tandem Electrocatalytic Alkyne Semihydrogenation over Bicomponent Catalysts through Hydrogen Spillover

AbstractElectrocatalytic alkyne semihydrogenation under mild conditions is a more attractive approach for alkene production than industrial routes but suffers from either low production efficiency or high energy consumption. Here, we describe a tandem catalytic concept that overcomes these challenges. Component (i), which can trap hydrogen effectively, is partnered with component (ii), which can readily release hydrogen for hydrogenation, to enable efficient generation of active hydrogen on component (i) at low overpotentials and timely (i)‐to‐(ii) hydrogen spillover and facile desorptive hydrogenation on component (ii). We examine this concept over bicomponent palladium‐copper catalysts for the production of representative 2‐methyl‐3‐butene‐2‐ol (MBE) from 2‐methyl‐3‐butyne‐2‐ol (MBY) and achieve a record high MBE production rate of 1.44 mmol h−1 cm−2 and a Faraday efficiency of ~88.8 % at a low energy consumption of 1.26 kWh kgMBE−1. With these catalysts, we further achieve 60 h continuous production of MBE with record high profit space.

Tandem Electrocatalytic Alkyne Semihydrogenation over Bicomponent Catalysts through Hydrogen Spillover.

Electrocatalytic alkyne semihydrogenation under mild conditions is a more attractive approach for alkene production than industrial routes but suffers from either low production efficiency or high energy consumption. Here, we describe a tandem catalytic concept that overcomes these challenges. Component (i), which can trap hydrogen effectively, is partnered with component (ii), which can readily release hydrogen for hydrogenation, to enable efficient generation of active hydrogen on component (i) at low overpotentials and timely (i)-to-(ii) hydrogen spillover and facile desorptive hydrogenation on component (ii). We examine this concept over bicomponent palladium-copper catalysts for the production of representative 2-methyl-3-butene-2-ol (MBE) from 2-methyl-3-butyne-2-ol (MBY) and achieve a record high MBE production rate of 1.44 mmol h-1 cm-2 and a Faraday efficiency of ~88.8 % at a low energy consumption of 1.26 kWh kgMBE -1. With these catalysts, we further achieve 60 h continuous production of MBE with record high profit space.

Continuous Synthesis of a Macrocyclic Sulfite of Polyethylene Glycol by Cascaded Continuous Stirred Tank Reactors (CSTRs).

Many macrocyclic compounds are attractive drug-like molecules or intermediates due to their special properties. However, the bulk synthesis of such compounds are hindered by the necessity of using diluted solutions, in order to prevent intermolecular reactions that yields oligomer impurities, thereby resulting in a low production efficiency. Such challenge can be adequately addressed by using continuous reactors, allowing improved efficiency with smaller space footprints. In this work, we proposed a novel continuous process for the synthesis of a macrocyclic sulfite of tetraethylene glycol (PEG4-MCSi), which is a precursor to a very useful building block, PEG4-macrocyclic sulfate (PEG4-MCS). The basic reaction parameters, including stoichiometry and temperature, were first confirmed with small batch reactions, and the effectiveness of coiled reactors and continuous stirred tank reactors (CSTRs) were compared. Cascaded CSTRs were proven to be suitable, and the reaction parameters were subject to further optimization to give a robust continuous process. The process was then tested with 4 parallel runs for up to 64 h. Finally, the merits and demerits of batch and continuous reactions were also compared, demonstrating the suitability of latter in the bulk production of macrocyclic PEG-MCSi compounds.

Multifunctional Sensors Made with Conductive Microframework and Biomass Hydrogel for Detecting Packaging Pressure and Food Freshness.

Food packaging detection devices have attracted attention to optimize storage situations and reduce food spoilage. However, low-cost and highly sensitive multifunctional sensors for detecting both food freshness and packaging pressure are still lacking. In this study, a multifunctional sensor was developed consisting of a MXene coated alcohol-soluble polyurethane fiber network (MXene/APU) and composite biohydrogel films made of konjac glucomannan, chitosan, and blueberry anthocyanin (KCB). Based on the pressure sensitivity of MXene/APU and the color changes of KCB in response to pH values, the sensor can detect internal package bulging, external squeezing, and food deterioration. The pressure sensor shows a sensitivity of 1.16 kPa-1, a response time of 200 ms, a wide strain range of 1092%, and stability over multiple loops. The pressure sensor could detect human motion and identify surface morphologies. The excellent sensor performance was attributed to the porous structure and large specific surface area of microfiber networks, conductivity of MXene nanosheets, and protective effect of KCB films coated on the conductive membrane. Besides, the microfluidic blow-spinning method used to prepare microfiber networks showed the advantages of low energy consumption and high production efficiency. Based on the color changes of blueberry anthocyanin loaded in KCB films in response to pH, the sensor realized sensitive spoilage detection of food containing protein. This study provides a new multifunctional food packaging sensing device and a greater understanding of the optimization and application of related devices.

Optimization of Expression and Purification of Recombinant One of Central Nervous System Enzyme (Acetylcholinesterase)

In general, the use of natural enzymes is very limited and they are not economical to use in industry. To solve this problem, the recombinant expression systems approach has been used. Optimization of production processes in heterologous expression systems is one of the most important activities in today's competitive industries. One of the key factors for the commercialization of recombinant proteins is the achievement of a low-cost culture medium available for the production of suitable cell biomass that can be used on an industrial scale. Commercialization of recombinant products requires process economics and cost reduction, and reducing the cost of the product is possible by using a cheaper culture medium, so decided optimization of expression and purification of recombinant acetylcholinesterase (EC.3.1.1.7), because it’s one of the body's vital enzymes, that by hydrolyzing acetylcholine, which is a neurotransmitter, terminates neural messages in the area of cholinergic synapses. Because the enzyme acetylcholinesterase produced from natural sources is not suitable for industrial purposes and semi-mass production due to low production efficiency and high costs of enzyme preparation and purification processes, optimizing the growth conditions of microorganisms capable of the production and secretion of the enzyme acetylcholinesterase are very important, both in terms of yield and economic costs. The present study seeks to increase productivity and reduce the cost of producing this enzyme by optimizing the growth medium and expression of pichia pastoris yeast cells that have genes related to this enzyme and also by optimizing the purification and mass production of this enzyme.

Bioelectrochemically enhanced biomethane production from low-rank coal using multiple microbial strains

Although microbial in-situ gasification of coal has been established to be an environmentally friendly and sustainable mining method, the low efficiency of methane production via coal micro-gasification limits the commercial applicability of this technology. In this regard, the application of electric fields can contribute to enhancing the efficiency of anaerobic microbial coal degradation. In this study, to investigate the effects of low-intensity electric fields on coal degradation by different exogenous microbial species, we conducted laboratory-scale batch anaerobic fermentation experiments at 0.9, 1.5, and 2.2 V using a micro-gas measuring device to quantify biogas production. The results revealed that application of a low-intensity electric field can promote the production of methane by different microbes, with the highest gas production (7.92 mL/g) obtained at 1.5 V, representing an increase of 131.58 % compared with fermentation conducted in the absence of an applied electric field. The electrodes facilitated the microbial utilization or dissolution of organic matter on the coal surface, leading to a reduction in surface functional groups, with the fermentation medium mainly comprising aromatic hydrocarbons. The coal particles at the anode appeared rough. Collectively, our findings in this study revealed that the application of electric fields contributed to a modification of microbial metabolism and promoted an enhancement of methane production. We believe these findings have important implications for enhancing the microbial production of biomethane from coal.