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Understanding the variation patterns of tunnel boring machine (TBM) operational parameters is crucial for assessing engineering geological conditions and quality grades of surrounding rock within tunnels. Studying the multifractal characteristics of the TBM operational parameters can help identify the patterns, but the relevant research has not yet been explored. This paper proposed a novel classification model for quality grades of surrounding rock in TBM tunnels based on multifractal analysis theory. Initially, the statistical characteristics of eight TBM cycle data with different grades of surrounding rock were explored. Subsequently, the method of calculating and analyzing the multifractal characteristic parameters of the TBM operational data was deduced and summarized. The research results showed that the TBM operational parameters of cutterhead torque, total thrust, advance rate, and cutterhead rotation speed have significant multifractal characteristics. Its multifractal dimension, midpoint slope of the generalized fractal spectrum, and singularity strength range can be used to evaluate the surrounding rock grades of the tunnel. Finally, a novel classification model for the tunnel surrounding rocks based on the multifractal characteristic parameters was proposed using the multiple linear regression method, and the model was verified through four TBM cycle data containing different surrounding rock grades. The results showed that the proposed multifractal-based classification model for tunnel surrounding rocks has high accuracy and applicability. This study not only achieves multifractal feature representation and surrounding rock classification for TBM operational parameters but also holds the potential for adaptive adjustment of TBM operational parameters and automated tunneling applications. [ABSTRACT FROM AUTHOR]

Due to its unique gravimetric energy density and zero carbon emissions, hydrogen is a top priority for the development of future clean and sustainable energy systems. To satisfy energy demand, underground hydrogen storage (UHS) is being adopted. Among underground hydrogen storage sources, aquifers may be one of the best places for large-scale storage of hydrogen (H 2). However, there is still lacking to understand the operational parameters of UHS, which is essential to achieve better UHS performance. In this study, operational parameters such as hydrogen production time, hydrogen injection rate, hydrogen production rate, frequency and length of cycles, shut-in period, number of wells, and spacing of wells are the focus of numerical simulations. Form the results, some insights are obtained as follows: (1) At higher hydrogen injection rates, H 2 recovery performance declined due to the short contact time between hydrogen and water, as well as lateral expansion of the gas. (2) Optimizing the hydrogen production rate and ensuring sufficient production time were crucial for enhancing hydrogen production performance. (3) Shorter lengths and higher frequencies of storage cycles contributed to an increase in the cumulative hydrogen production volume. Moreover, introducing a shut-in period between the injection and production periods exhibited a detrimental effect on the performance of UHS. (4) In the dual-well configuration, cumulative hydrogen production volume and cumulative recovery efficiency experienced increases of at least 0.51 × 107 m3 and 9.27%, respectively. Concerning well spacing, its impact on the performance of UHS was slight. The effectiveness of UHS in aquifers was confirmed by these results. These understandings provide a certain basis for the optimization of operating parameters. • A comprehensive analysis of operational parameters for optimizing hydrogen storage in an aquifer was performed. • The recovery performance of hydrogen decreased as the injection rate varied. • Boosting hydrogen production rate and ensuring sufficient production time are essential for enhancing performance. • Introducing the shut-in period between the injection and production periods proved to be disadvantageous. • A significant improvement in hydrogen recovery efficiency was observed with an increase in the number of wells. [ABSTRACT FROM AUTHOR]

This paper introduces a novel solution to mitigate the vulnerability of operational parameter tampering in the semiconductor industry through a customized blockchain protocol. Faced with high costs and rapid market demands, the industry often struggles with production efficiency due to the variability in equipment operators’ skills and human errors. This challenge is compounded by the necessity for continuous parameter updates and collaboration with equipment suppliers. Our proposed solution leverages the security strengths of blockchain technology, renowned for its secure, immutable record-keeping capabilities. We focus on developing a specialized blockchain-based system, the blockchain-based parameter matching (BBPM) protocol, to manage and safeguard operational parameters within semiconductor manufacturing. This system is designed to ensure secure, tamper-proof information updates, addressing the industry’s need for reliable and efficient parameter management. The BBPM protocol addresses the dual risks of unauthorized parameter modifications and unintended changes by authorized users, ensuring the integrity of operational parameters crucial for quality control in semiconductor processes. This protocol represents a transformative shift in operational parameter management systems from traditional centralized models to a distributed approach. By adopting a decentralized and tamper-resistant framework, the BBPM protocol can enhance the efficiency and quality of operational parameter management while reducing the need for extensive data storage, a common challenge in centralized systems. This shift marks a critical advancement in information management and security within the semiconductor manufacturing.

When excavating in composite strata, the wear rate of the disc-cutters and the frequency of abnormal wear will significantly increase. Therefore, the overcut clearance is accordingly reduced, which results in the occurrence of shield jamming accidents. In order to analyze the influence of shield attitude deflection and longitudinal non-uniform distributed overcut on the mechanical properties of shell, based on Baiying section on Shenzhen metro line 13, the rock pressure exerting on shield machine during construction stage was calculated by FLAC 3D. The results indicate these as follows. Severe eccentric wear occurred at the jamming section. The maximum wear reaches 25 mm. The operational parameters encounter obvious fluctuation in composite strata. The shield machine has a higher tendency to deflect upwards. In upper soft and lower hard strata, the rock pressure borne by the upper part of the shield shell is larger than which on the lower part. The stress concentration occurs at the interface between the strata. The stress at front of the shield shell grows more significantly, compared with which at the shield tail. The normal pressure at the tunnel vault and invert respectively increases, when the shield deflects upward and downward. The upward deflection is more likely to cause jamming accident compared to the downward deflection. The friction suffered by shield shell rises rapidly when the deflection angle exceeds ± 0. 5°. During shield tunneling, the shield machine should maintain a horizontal or small angle downward deflection state as far as possible. [ABSTRACT FROM AUTHOR]

Dyes are one the foremost hazardous pollutants that affects bio life including the flora and fauna and removing of those pollutants from contaminated environment are remarkable activities within the scientific community. In this respect, the current study is focused on preparation of physiochemical activated cereals based tella residue bio adsorbent for basic blue dye (MB) removal from aqueous environment. Different analytical methods have been utilized to assess the thermal stability, surface area, surface morphology, pore size, pore volume, surface functional group, and a few proximate analyses of the prepared bio adsorbents. The SEM and BET results of the adsorbents reveals physiochemical activation process assists for the formation of visible pores, cracks, irregular shape, and better surface area (51.32 m2 /g for RTR and 565m2 /g for ATR) respectively. The removal efficiencies of MB by RTR and ATR in an exceedingly batch experiment were 88.4s and 97.2 % at situation of pH (8); adsorbent dosage (0.8 for RTR and 0.6 for ATR), agitation speed (300 rpm), dye concentration (10 mg/L), temperature (298o K) and contact time (100 minute) respectively. The kinetics and equilibrium result of dye adsorption process well described by Pseudo 2nd order kinetic and Langmuir isotherm model respectively. The thermodynamic finding result shows the spontaneous and endothermic nature of the sorption process. The probable adsorption mechanism of MB dye on the prepared bio adsorbents surface may be assigned mainly through chemisorption. The results of this study show, the current adsorbents promise an alternate green rout for treatment dye contaminated wastewaters. [ABSTRACT FROM AUTHOR]

To be consistent with the actual production, this paper establishes the 2-D steady-state mathematical model of the porous media to numerically analyze influences of structural and operational parameters on the vertical cooling process by applying particle characteristic parameters, and heat transfer and resistance correlations of the multi-size sinter. Considering comprehensive effects of the temperature and pressure drop, the operating and structural parameters are optimized with the objective of the maximum income exergy of the gas. Results show that the numerical model established in this paper can well predict the gas-solid heat transfer process in the sinter bed with the maximum error of 7%. Besides, the income exergy of the gas increases and decreases with the sinter outlet temperature and gas outlet temperature increasing, respectively. The reduction in the equivalent particle diameter is conducive to improving the income exergy. What’s more, the income exergy of the gas first ascends and then descends with the increase of the flow rate ratio of gas to sinter and the height of the sinter layer. Therefore, optimal values of the flow rate ratio of the gas to sinter and the height of the sinter layer are 1,050–1,540 m3·h−1 and 7–11.5 m within the scope of this study, respectively.

To mitigate the potential hazards of shield tunneling misalignment (STM) caused by tunneling posture deviation, a method for optimizing operational parameters tailored to tunneling posture adjustment is developed. This paper presents a generative adversarial network (GAN) framework that incorporate a conditional generative adversarial network (CGAN) and two distinct discriminators (WGAN and Path GAN) to enhance the performance of the multi operational parameter generator. Based on engineering data, comparative experiments are designed to investigate the impact of the feature extraction methods, discriminators, and training strategies on the generation performance. Research has shown that an optimal generator scheme, comprising independent convolutional neural networks (CNNs), a summation feature fusion strategy, and a shared decoder, achieves remarkable performance with an MAE of 0.009, RMSE of 0.012, and average error scope of 0.073. Applications of the model confirm its ability to provide optimization suggestions for shield tunneling posture adjustments in engineering scenarios. • A new method for adjusting the operational parameters of the shield is proposed. • The method has been validated through the data collected from the railway. • Obtained a multi-parameter generator with high accuracy. • The influence of different factors on the performance of the generator are analyzed. [ABSTRACT FROM AUTHOR]

A detailed test work was carried out with an industrial semi-autogenous (SAG) mill in a copper plant in close and open circuits to specify the effects of ore characteristics and operational parameters on mill performance. In addition, the shape of mill product particles was studied to monitor breakage events as a function of ore strength. For this purpose, the strength properties of the SAG mill feed and product were specified by different techniques, including the point load index, impact breakage parameters (A × b), abrasion index (ta), and Bond ball mill work index (Wi). Experimental studies showed that an increase in ore hardness is linked with an increase in point load index and Bond work index and a decline in impact breakage parameter (A × b). Hard ore grinding resulted in finer products, compared to the soft ore milling. The softer ore is ground chiefly via the impact breakage whereas the stronger ore is subjected to abrasion and attrition events where the media impact could not sufficiently break the stronger particles. The main reason for the decrease of circuit throughput was changes in breakage mechanisms. The results displayed that the highest aspect ratio and the lowest circularity of mill product are achieved by soft ore milling. As ore strength changes, differences in shape can be attributed to the different breakage mechanisms operated in the mill. In addition, the particle shape characteristics provide a convenient way to quantify changes in SAG mill as a function of the ore properties and the kind of breakage action used. [ABSTRACT FROM AUTHOR]

Biochar amendment for landfill soil cover has the potential to enhance methane removal efficiency while minimizing the soil depth. However, there is a lack of information on the response of biochar-mediated soil cover to the changes in configuration and operational parameters during the methane transport and transformation processes. This study constructed three biochar-amended landfill soil covers, with reduced soil depths from 75 cm (C2) to 55 cm (C3) and 45 cm (C4), and the control group (C1) with 75 cm and no biochar. Two operation phases were conducted under two soil moisture contents and three inlet methane fluxes in each phase. The methane removal efficiency increased for all columns along with the increase in methane flux. However, increasing moisture content from 10% to 20% negatively influenced the methane removal efficiency due to mass transfer limitation when at a low inlet methane flux, especially for C1; while this adverse effect could be alleviated by a high flux. Except for the condition with low moisture content and flux combination, C3 showed comparable methane removal efficiency to C2, both dominating over C1. As for C4 with only 45 cm, a high moisture content combined with a high methane flux enabled its methane removal efficiency to be competitive with other soil depths. In addition to the geotechnical reasons for gas transport processes, the evolution in methanotroph community structure (mainly type I methanotrophs) induced by biochar amendment and variations in soil properties supplemented the biological reasons for the varying methane removal efficiencies. • Biochar amendment enhanced the CH 4 removal capacity of landfill soil cover. • Thick soil cover with biochar benefited CH 4 removal at dry soil & low CH 4 flux. • Thin soil cover with biochar benefited CH 4 removal at wet soil & high CH 4 flux. • Evolution of type I methanotroph explained the varied CH 4 removal efficiencies. [ABSTRACT FROM AUTHOR]

Bhayander estuary is a very sensitive ecosystem due to the disposal of industrial effluents and heavy load due to urbanisation, but still it hold stand firmly as the breeding and nursery ground for many commercially important species of Maharashtra and the dol net fishery in this region provides a source of livelihood to the traditional fishermen. The overall size of dol net operated in this estuary varied from 12 to 14 m and the numbers of dol nets/vessel varied from one to three. The mesh size of the dol nets varied between 8 to 160 mm across its different parts from cod end towards mouth of the net. The average number of fishing days of single-day dol netters per month varied from 12 to 16 days. Maximum distance of dol net station was 1.4 km from the landing jetty and mean distance travelled by dol netters was 0.8 km. The present study highlights the detail structural design and the operational parameters of the dol net operated in this estuary. [ABSTRACT FROM AUTHOR]

Improving the removal efficiency of iron-rich impurities and the uniformity of component distribution is an indispensable step in recycling aluminosilicate solid waste to prepare the raw materials of glass ceramics, which can be achieved by smelting reduction separation in the induction furnace. In this work, a multi-physics real-time coupling model that integrates carbothermal reduction and interfacial mass transfer between two-phase melts in the induction furnace was proposed to improve the conventional methods that simulate the interface profile and multi-physics separately. By solving the numerical model, the reduction degree, energy consumption and component distribution can be predicted and the characteristics of mass-heat-component transport and interphase mass transfer can be obtained. For the collaborative optimization of multiple parameters, including current, frequency, and melting duration, an inverse design method that integrates CFD-ANN-NSGA-II was proposed to minimize the iron oxide (FeO) residual and energy consumption, and maximize the uniformity of components in the glass phase simultaneously. The optimal operating parameters set were determined by analysis of the Pareto front and the selection criteria. Further analysis of the Pareto solution set provides a fundamental basis for regulating the operational parameters of different reduction degrees. Overall, the inverse design method that synthesized the proposed numerical model is an effective way of predicting and optimizing the operating parameters of induction heating furnaces of iron removal from solid wastes. • Inverse design method to optimize operating parameters for iron removal was proposed. • Multi-objective optimization aims to maximize reduction degree and uniformity. • Reaction was coupled to the two-phase electromagnetic drive flow model in real-time. • Pareto front was obtained by NSGA-II algorithm embedded in ANN-based surrogate model. • High or low reduction degree corresponds to different parameter adjustment schemes. [ABSTRACT FROM AUTHOR]

The most important processes which take place in a technical system are the operation and service processes. Knowing the actual technical state of the system, it is possible to make a decision whether the system can operate or should be serviced. The efficiency of the system operation and the possibility of the failure occurrence strongly depend on the relevancy of this decision. The technical state of the system is described by the system features affected by the time histories of its operational parameters. Unfortunately, the amount of the operational parameters can be significant. Therefore, it becomes purposeful to identify the operational parameters significant from the system technical state evaluation point of view. In the article, the universal method of the significant operational parameters identification and the research carried out in a real industrial system to verify its correctness and the accuracy are presented. [ABSTRACT FROM AUTHOR]

Recently, an increasing level of attention has focused on the emerging technology of anaerobic dynamic membrane bioreactors (AnDMBRs), owing to its merits such as low membrane module cost, easy control of membrane fouling, low energy consumption and sludge production, as well as biogas production. As research on AnDMBRs is still in the nascent stage, an introduction of bioreactor configurations, dynamic membrane (DM) module, and DM layer formation and cleaning is firstly presented. The process performance of the AnDMBR for wastewater treatment is then reviewed with regard to pollutant removal, DM filterability, biogas production, and potential advantages over the conventional anaerobic membrane bioreactor (AnMBR). In addition, the important parameters affecting process performance are briefly discussed. Lastly, the challenges encountered and perspectives regarding the future development of the AnDMBR process to promote its practical applications are presented. [ABSTRACT FROM AUTHOR]

As a consequence of climate change, urban overheating has increased in all the cities of the world during the last decades. It is therefore paramount to counteract such effect by promoting the use of effective solutions to mitigate overheating at a micro-scale level. In this work, a modular experimental setup based on a water spray system was designed, realized and tested to evaluate its thermohygrometric performance in semi-outdoor spaces such as bus/train/taxi stops, street resting stations and corner shops. The setup allows to vary three operational parameters: (a) the height of the nozzles from the ground; (b) the presence of an upper shielding to reduce the impact of solar radiation; (c) the presence of a side shielding to reduce the impact of wind speed. The combination of the operational parameters allowed to evaluate the performance of five configurations for the water spray system. Several performance indexes were calculated to assess the impact of each operational parameter. It was found that the best configuration guarantees a −20% reduction of dry-bulb temperature, and the minimum specific water and electricity consumptions of the system are 0.020 L/m2 and 0.150 Wh/m2, respectively. Also, the presence of the side shielding is the parameter that mostly influences the performance of the system, followed by the height of the nozzles, while the presence of the upper shielding has a minor effect. These operational parameters, however, increase relative humidity inside the nebulization volume; it is therefore important to verify if undesired wet conditions are reached. • A modular water spray system is designed, realized and tested. • Three operational parameters and five configurations are evaluated. • The best configuration guarantees a −20% reduction of dry-bulb temperature. • The minimum specific water and electricity consumptions are 0.020 L/m2 and 0.150 Wh/m2. • The presence of the side shielding mostly influences the performance of the system. [ABSTRACT FROM AUTHOR]

Experimental results show that the cross-flow hollow fiber membrane contactor is the controlling component of the humidification dehumidification desalination system performance. Three sets of main operating conditions sensitivity analyses are performed numerically, including solution conditions (temperature, salinity, flow rate), air conditions (temperature, relative humidity, flow rate) and dimensionless parameters (number of heat transfer units, flow rate ratio of solution to air). Increasing flow rate ratio can effectively promote freshwater production rate before flow rate ratio reaches a critical value of 6.0. It is useful to improve moisture effectiveness by increasing number of heat transfer units. Solution inlet temperature has an exponential promoting effect on membrane flux, which is consistent with the exponential upward trend of the solution phase equilibrium humidity. Membrane flux increases dramatically at first and then slowly after solution flow rate exceeds 228 kg/h and air flow rate exceeds 57 kg/h. Ambient air with high temperature and relative humidity as well as the high salinity of the solution will slightly degrade the membrane flux. • A two-dimensional mathematical model was established for cross-flow hollow fiber membrane contactor. • Humidification characteristic of membrane humidifier and the dehumidification characteristic of condenser were expounded. • Effects of comprehensive operating parameters on transmembrane water flux and humidification effectiveness were analyzed. • Optimal design of membrane contactor operating conditions was performed. [ABSTRACT FROM AUTHOR]

Highlights: [•] The effect of operational parameters on SAGD performance is investigated. [•] Dip heterogeneous NFR with oil wet rock is studied. [•] The CMG-STARS thermal simulator is used for this purpose. [ABSTRACT FROM AUTHOR]

BP neural network model was used to predict the cleaned coal ash and combustible recovery in different operational conditions. Taking the circulation pressure, air flow, dosage of collector and frother as input set, the BP neural networkas prediction model was proposed to estimate the cleaned coal ash and combustible recovery as outputs. It is shown that BP neural network model can estimate the separation index quite satisfactorily in which the relative errors between the predicted values and experimental values are both less than 5% for the cleaned coal ash and combustible recovery. [ABSTRACT FROM AUTHOR]

Abstract: To improve the efficiency of total nitrogen (TN) removal, solid retention time (SRT) and internal recycling ratio controls were selected as operating parameters in a full-scale activated sludge process treating high strength industrial wastewater. Increased biomass concentration via SRT control enhanced TN removal. Also, decreasing the internal recycling ratio restored the nitrification process, which had been inhibited by phenol shock loading. Therefore, physiological alteration of the bacterial populations by application of specific operational strategies may stabilize the activated sludge process. Additionally, two dominant ammonia oxidizing bacteria (AOB) populations, Nitrosomonas europaea and Nitrosomonas nitrosa, were observed in all samples with no change in the community composition of AOB. In a nitrification tank, it was observed that the Nitrobacter populations consistently exceeded those of the Nitrospira within the nitrite oxidizing bacteria (NOB) community. Through using quantitative real-time PCR (qPCR), nirS, the nitrite reducing functional gene, was observed to predominate in the activated sludge of an anoxic tank, whereas there was the least amount of the narG gene, the nitrate reducing functional gene. [Copyright &y& Elsevier]

Abstract: In the present study the influence of suction time, backflush time and aeration intensity on fouling was investigated using 23 factorial design. The experimental study has been performed using a tubular membrane module (pore size 0.4μm) immersed in a 60l aerated activated sludge tank treating dyehouse wastewater. Maximum and minimum values for suction time (8–16min), backflush time (25–45s) and aeration intensity (0.3–0.9m3/(m2 h)) were adopted as the base of membrane operation. Average resistance increase rate over an operation time of 7 days for each experiment was used to evaluated fouling behavior. Concerning the fouling ability of the three factors, suction time was observed to have the largest effect on resistance increase followed by aeration intensity and backflush time. Both aeration intensity and backflush time contributed to fouling reduction at a similar level and exhibited significant interactions with suction time. Aeration intensity and backflush time strongly affected fouling at high suction time. There was a critical netflux-ratio of 0.85, below which high aeration intensity did not further contribute to fouling amelioration. Above the critical value heavy fouling occurred. This effect can be outbalanced by an increase in aeration intensity to a certain extent. With simultaneous consideration of cost relevant parameters in terms of membrane area requirements, energy demand and chemical cleaning interval, optimum conditions was assumed to be at the critical value. At this point suction time can be varied in the range of 8–14.2min with a corresponding backflush time between 25.3 and 45s, respectively. Due to the fouling potential associated with suction time operation at the minimum value of 8min was suggested. [Copyright &y& Elsevier]

A method for estimating the influence of operational mode parameters of a turbo-generator unit on its vibrational state is proposed and recommended for application in the automated vibration- monitoring system for turbo-generator rotors. Correlation and graphic methods are applied for determining the interrelation between the operational mode parameters and vibrational characteristics of a turbo-generator unit. Results of full-scale investigations on the vibrational state kinetics of the generator in variation of its power consumption are presented. [ABSTRACT FROM AUTHOR]

In the present study, an orthogonal array design was adopted to investigate effects of operational parameters including aeration intensity, membrane flux, suction time and non-suction time on sludge accumulation on membrane surfaces respectively at a high SS concentration of 10 g l−1 and a low SS concentration of 1 g l−1 in a submerged membrane bioreactor. Average transmembrane pressure (TMP) increase rate over the operation time was used to evaluate sludge accumulation. Among the four factors, membrane flux was found to influence TMP the most obviously. The effect of aeration intensity became significant only at a high SS concentration of 10 g l−1. TMP increased with suction time and decreased with non-suction time. There was a critical membrane flux over which sludge particles were deposited, and accordingly, TMP increased sharply. Two zones, predicting whether sludge particles are deposited or not, could be comprehensively determined by the critical flux, correspondent aeration intensity and SS concentration. For long-term stable operation, it is suggested that a membrane bioreactor be operated in the zone with prediction of no obvious sludge deposit on membrane surfaces. [Copyright &y& Elsevier]

[Display omitted] • Investigation of the MP particle removal properties in an aerobic bioreactor. • Study of operational factors, together with PE, PP, and PVC. • In-depth study and discussion of the particle size distribution and removal efficiency. • Presentation of optimum operational parameters through ANOVA. • Adoption–desorption pathway of sludge in retaining MP particles. Given the large number of existing wastewater treatment plants (WWTPs), this paper investigates the effects of routine operational factors on retaining the properties of the microplastics (MPs) of a typical aerobic bioreactor, which is widely adopted in both municipal and industrial WWTPs. The three most detected plastics, namely, polyethylene, polypropylene, and polyvinyl chloride, are pulverized and injected into an anoxic–oxic configured laboratory facility to explore the size distribution and removal efficiency of the MPs in the effluent. A laser particle analyzer is used for the continuous particle size distribution testing, which indicates that nearly all the particles whose diameters exceed 35 μm are retained. This phenomenon poses a threat to mammal health for particles less than 20 μm in diameter that dominate the effluent's abundance. Comprehensive discussions and comparisons with existing works in terms of how the three operational factors affect the bioreactor's retaining properties significantly are presented. The moderate mixed liquor suspended solids and short hydraulic retention time of the bioreactor are beneficial to the MPs removal based on the in-depth analysis of variance of the limited experiment runs. Furthermore, the sludge in the bioreactor renders an adsorption–desorption pathway in retaining the MPs. [ABSTRACT FROM AUTHOR]

This paper review is aiming to comprehensively identify and appraise the current available knowledge on microbial composition and microbial dynamics in anaerobic digestion with focus on the interconnections between operational parameters and microbial community. We systematically searched Scopus, Web of Science, pubmed and Embase (up to August 2019) with relative keywords to identify English-language studies published in peer-reviewed journals. The data and information on anaerobic reactor configurations, operational parameters such as pretreatment methods, temperature, trace elements, ammonia, organic loading rate, and feedstock composition and their association with the microbial community and microbial dynamics were extracted from eligible articles. Of 306 potential articles, 112 studies met the present review objectives and inclusion criteria. The results indicated that both aceticlastic and hydrogenotrophic methanogenesis are dominant in anaerobic digesters and their relative composition is depending on environmental conditions. However, hydrogenotrophic methanogens are more often observed in extreme conditions due to their higher robustness compared to aceticlastic methangoens. Firmicutes and Bacteroidetes phyla are most common fermentative bacteria of the acidogenic phase. These bacteria secrete lytic enzymes to degrade organic matters and are able to survive in extreme conditions and environments due to their spores. In addition, among archaea Methanosaeta , Methanobacterium , and Methanosarcinaceae are found at high relative abundance in anaerobic digesters operated with different operational parameters. Overall, understanding the shifts in microbial composition and diversity as results of operational parameters variation in anaerobic digestion process would improve the stability and process performance. • A comprehensive review was performed on microbial composition in anaerobic digestion process. • The environmental and operational parameters extensively influence the microbial community and diversity. • Hydrogenotrophic methanogens are more often observed in extreme conditions due to their higher robustness. • Understanding the shifts in microbial composition and diversity would improve the stability and process performance. [ABSTRACT FROM AUTHOR]

• The method is suitable to large-scale power system eigen-sensitivity analysis. • State matrix sensitivity is able to be evaluated by numerical approach efficiently. • Reuse of LU factorization accelerates solving perturbed power flow equations. • Parallelization reduces overall computational time with well scalability Eigenvalue sensitivity with operational parameters provides necessary information for tuning power system operating status and improving small signal stability. Presently, with the inter-connection of regional power grids, power systems expand to be of large scale, which raises demanding requirements for computational efficiency of eigenvalue sensitivity analysis. For addressing this issue, a modified numerical method is proposed for computing eigenvalue sensitivity with respect to power system operational parameters, including active and reactive power outputs of generation units, load demands and bus voltages. Well computational efficiency is obtained by the proposed method, which is mainly attributed to the reuse of LU factorization in solving perturbed power flow equations, the numerical finite difference for evaluating state matrix sensitivity, and utilization of parallel computing techniques. Numerical experiments on different scale power systems from realistic world are performed to validate its effectiveness and efficiency. Parallelization of the proposed method is implemented for further reducing overall time cost. Moreover, the proposed method is integratable to functional modules of existing power system analysis software, which makes its implementation convenient. [ABSTRACT FROM AUTHOR]

This study was aimed to evaluate bio-hydrogen production from sugarcane vinasse by the mixed culture enriched through controlling operational parameters in an Anaerobic Sequencing Batch Reactor (AnSBR), as well as determining the effect of the sugarcane vinasse concentration on hydrogen production and the critical kinetic analysis. The Volumetric Hydrogen Production Rate (VHPR) of 28.1 mL H 2 /L h at the substrate concentration of 10 g COD/L was obtained in biomass enriching step. In batch tests, the increase in substrate concentration ranging from 1.70 to 11.60 g COD/L caused an increase in Hydrogen Yield (HY); however, it had a negative effect on HY at the substrate concentrations of higher than 11.60 g COD/L. The maximum HY in terms of initial Chemical Oxygen Demand (COD i) of 58.41 mL H 2 /g COD i was obtained at the substrate concentration of 11.60 g COD/L. Additionally, Andrew and Han-Levenspiel models were employed to model the hydrogen production rate (R) in case of different chemical oxygen demand (COD) concentrations of vinasse. According to the comparison made between the correlation coefficient values of the fittings using the aforementioned models, the Han-Levenspiel model could be considered as a better model to describe the substrate inhibition effect. The carbohydrate removal efficiency was superior to 90% at substrate concentrations less than 16.80 g COD/L. [ABSTRACT FROM AUTHOR]