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Monitoring the degradation of induction motors is an essential concern for industries, especially when there are high costs related to maintenance and their stops. Nowadays, there are many non-invasive ways to monitor the health status of induction motors, including sensors to measure temperature, magnetic field, vibration, current, and power. However, installing these sensors may not be a simple task since intrusive procedures such as engine disassembling, wire separation, and engine interruption are commonly observed. Thus, we propose MUCLA (Multiphase Clamp and Tracking - patent pending) as a new device and methodology for monitoring motor degradation by analyzing its stator current. MUCLA introduces a non-invasive current sensors array on a proposed clamp in the hardware perspective, while a spectral tracking methodology refers to our novelty in the software viewpoint. For end-users, the main MUCLA contribution relies on the combination of the simplicity of installation and the possibility of using the proposed device even when considering Variable-Frequency Drive powered engines. The results obtained with both simulation and practical tests show encouraging results over different input workloads and emulated degradation. Compared to the current initiatives, we can classify MUCLA as a better solution for industrial plants in terms of installation time, installation complexity, and cost.

Based on advanced information and communication infrastructures and enabled with the cutting-edge information processing of cognitive computing, existing smart manufacturing systems have foreseen a prevailing tendency that approaches a higher automation level, i.e., Self-X (e.g., Self-configuration/optimization/adaptation). However, the readiness of ‘Self-X’ levels is still far to reach, encountering the practical challenges of semantics-based networking and human-machine untrust in the manufacturing scenario. To mind these gaps, the authors envision an industrial knowledge graph (IKG) and graph embedding (GE) enabled pathway, to flourish today’s smart manufacturing paradigms towards cognitive mass personalization. To pave it, three promising IKG and GE enabling techniques in the ‘Self-X’ cognitive manufacturing network are described. Potential opportunities and challenges are also pointed out to invite more opinions to refine and innovate the exploitation of IKG and GE for the future of smart manufacturing.

This paper systematically describes the technical principles, evaluation indicators, system forms and research progress of air-side evaporative cooling air conditioning systems, water-side evaporative cooling air conditioning systems and freon-side evaporative cold coagulation heat air conditioning systems of Data center. In order to reduce the energy consumption of the refrigeration and air-conditioning system in the Data center, the application conditions and scenarios of the different forms of evaporative cooling air-conditioning systems should be considered comprehensively. Therefore, it is very important that the renewable energy-dry air can be used to the greatest extent. These efforts would contribute to China's 2030 "Carbon Peak" and 2060 "Carbon Neutral."

Ship-hull design is a complex process, because the small local alteration in ship hull structure may significantly change the hydrostatic and hydrodynamic performances of a ship. To find the optimum hull shape under the design requirements, the state-of-art of ship hull design combines computational fluid dynamics computation with the geometric modeling. However, this process is very computationally intensive, which is only suitable at the final stage of the design process. To narrow down the design parameter space, in this work we have developed an AI-based deep learning neural network to realize a real-time prediction of the total resistance of the ship-hull structure in its initial design process. In this work, we have demonstrated how to use the developed DNN model to carry out the initial ship hull design. The validation results showed that the deep learning model can accurately predict the ship hull’s total resistance accurately after being trained, where the average error of all samples in the testing dataset is lower than 4%. Simultaneously, the trained deep learning model can provide the information about a ship’s performances in real-time by inputting geometric modification parameters without tedious preprocessing and calculation processes. The machine learning approach in ship hull design proposed in this work is the first step towards the artificial intelligence-aided design in naval architectures.

A case study of the steel–concrete composite structure in the Pidie Jaya Regency Multipurpose Hall which experienced substantial permanent lateral deformation due to the effect of an earthquake is presented in this study. Therefore, it is important to assess the response of the structure to earthquake load and propose the strengthening strategies to make the buildings useful again. The purpose was to evaluate the causes of large deformations and the behavior of structure in resisting earthquake loads. The building structure model used in this study is a space frame with two-column base support conditions which are fixed and hinged supports after which a non-linear time history analysis was conducted. The time history analysis was conducted using five ground motion acceleration data recorded during earthquakes to determine the deformation and it was found that the large structure permanent deformation was due to the small structure stiffness in the direction of the deformation due to the use of only one column row in front of the building. Moreover, hinged support was observed to have caused a greater deformation than fixed support but was found not to be the main cause of large permanent deformation of the structure. The building structure was further strengthened by adding 4 columns while the oblique columns remained in a sloping condition. Meanwhile, the response spectrum analysis showed the strengthening structure was able to withstand earthquake loads with less deformation than the required standard.

A cost-effective stereolithography for medium-scale components is developed to fabricate 3D components with high build speed and resolution from photo-curable resin. The developed SLA utilizes a focused light beam of wavelength range (300 nm–700 nm) coming from the DLP projector and passes through the objective lens and finally imposed on the platform containing a layer of photo-curable resin. After focusing the light beam on the liquid resin layer, the photo-polymerization reaction occurs and the liquid resin becomes solid. Thus, the 3D object is fabricated layer by layer curing of liquid resin. The photopolymer used in this experimentation is polyethylene glycol di-acrylate and Irgacure 784 as photo-initiator. The Creo 3.0 software is used for modelling of 3D objects. A special MATLAB code is developed for slicing of the 3D model and displaying the sliced image one by one through DLP projector. The Arduino microcontroller with stepper motor and ball screw is used to control the motion of Z-stage platform. The Creation workshop software is also used to control motion of the Z-stage and period to display the sliced images through DLP projector. The medium-scale 3D objects with rectangular, square, and circular cross-sections are obtained by curing the aforementioned photo-curable resin. It is observed that the 3D objects are best cured for two seconds curing time with 0.1 mm curing depth along Z-axis.

This paper presents a practical optimum design solution of prismatic simply supported prestressed concrete girders that are subjected to uniformly distributed static loads. While assuming linear elastic behaviour and employing working stresses method, the optimum values of two design variables, namely the cross-sectional dimensions and the prestressing force, are formulated as a nonlinear optimization model. Optimum values of the design variables are computed to satisfy either a minimum weight or a minimum cost objective function. To solve the nonlinear programming models, a program named Non-Linear Programming Prestressed Concrete Optimizer (NLPRECO) was coded in MATLAB® programming environment. Some illustrative design problems were solved using NLPRECO and their results are demonstrated herein. Sensitivity analysis of the optimized design variables, to variations in design parameters, was also investigated and the results are presented. Results show substantial improvement over the regular un-optimized solutions and moderate improvement over a linear programming optimization solutions.

This study addresses performances and behaviors of the multi-cross-section HAWT blade design with and without fences. The FX66-S-196 V, FX63-137 S and SG6043, supercritical airfoils were used and distributed along the blade radius; further, the NACA4412 single-cross-section HAWT blade having the same dimensions was used to compare the behaviors and overall performances of all the blades. Analyses were then performed numerically using blade elements momentum BEM theory with a self-code (F.90) and CFD as well as experimentally with three multi-cross-section blades designed using SOLIDWORKS and 3D- printed with polylactic acid. the multi-cross-section HAWT blades show good performance compared with the single- cross-section blade, with an approximately 8% increase in power coefficient, i.e., 40 W, for a miniature wind turbine (127 cm diameter 500 W output power) and greater improvements for wind turbines with large diameters. The fences were designed using boundary layer theory and installed on multi-cross-section blades in experimentally determined positions. The fences showed high performance, with a 16% increase in total power coefficient and high flutter stability.

The purpose of this study was to determine the strength of hollow concrete block masonry walls, beams, and columns, and compare their values with brick masonry walls and ordinary reinforced concrete beams and columns. The specimens for the hollow concrete block and brick masonry walls were prepared and tested for compressive and flexural strengths as well as horizontal and diagonal shear strengths. Moreover, two hollow concrete blocks and two ordinary reinforced concrete beams were designed to experience flexural and shear failure and loaded under a two-point bending load. Meanwhile, a hollow concrete block and an ordinary reinforced concrete column were also constructed and subjected to centric axial loads until they collapsed. The results showed the hollow concrete block masonry walls have greater strength than those made with bricks while both flexural and shear capacity as well as the flexural ductility of reinforced hollow concrete block beams were higher than ordinary reinforced concrete beams. Meanwhile, the centric compressive axial strength of the reinforced hollow concrete block column was smaller due to the inefficient bond it has with the infilled concrete which leads to their separation under the compressive axial load.

A large-span steel–concrete composite beam with precast hollow core slabs (CBHCSs) is a relatively new floor structure that can be applied to various long-span structures. However, human-induced vibrations may present serviceability issues in such structures. To alleviate vibrations, both the walking forces excited by humans and the associated floor responses must be elucidated. In this study, 150 load–time histories of walking, excited by 25 test participants, are obtained using a force measuring plate. The dynamic loading factors and phase angles in the Fourier series functions for one-step walking are determined. Subsequently, walking tests are performed on seven CBHCS specimens to capture the essential dynamic properties of mode shapes, natural frequencies, damping ratios, and acceleration time histories. The CBHCS floor system generally exhibits a high frequency (> 10 Hz) and low damping (damping ratio

The linearity assumption is widely used when acquiring the hydrodynamic coefficients of a floating structure. However, the linear damping is frequently underestimated, especially for the natural frequency. To investigate the sloping seafloor effects on the damping terms of a single module of a semi-submersible Very Large Floating Structure (VLFS), this paper revisits the conventional formulation and further proposes the direct integration method for obtaining the linear and quadratic damping coefficients from free-decay tests. Numerical free-decay simulations of the single module over variable bathymetry are carried out by the CFD numerical tank. Corresponding model tests are also implemented to verify and validate against the numerical solutions. The effects of the sloping seafloor, as well as the water depth, on the hydrodynamic coefficients are investigated based on the validated CFD modeling. Both numerical and experimental results indicate that the acquisition of the linear and quadratic damping coefficients is sensitive to the data-processing and identification approaches. For the case studied in present paper, the identification errors introduced by the conventional method are 1.5 % while they are 0.5 % using the direct integration method. The quadratic damping coefficient for heave mode decreases about 10.4 % when the sloping angle increases from 0 to 6 deg.

A mechanistic model has been applied for the prediction of corrosion rate in multiphase (water–oil-gas) flow regimes. This is due to inadequacies of existing models to adequately address a wide variety of corrosion dependent parameters with special emphasis on multiphase flow parameters. This model takes into account; water cut, volumetric phase fraction of oil and gas, temperature, pressure, other data collected relating to the pipe age, sand particle deposit, CO2 partial pressure, flow velocity, pH, chloride contents, mass transfer coefficients, and hydrogen sulfide. The applied model results show well above 91 percent prediction accuracy, while the prediction error ranges between 0.022 and 0.045 percent. When predicted results compared actual value (experimental data) with DeWaard and Milliams’ model; used in the oil and gas industries, it showed good agreement. It is seen that the resulting model produced an R2 value of 0.91 in comparison to 0.53, the value for Dewaard and Milliams’. It is obvious from numerical simulation that the multiphase flow parameters have major effects on the entire rate of corrosion of oil and gas multiphase flow pipelines. Finally, this research concluded by showing the developed model performance and comparison was made with numerical results. It is expected that the outcome of this research will be of significant help for the strengthening of the application of mechanistic models for predicting corrosion rate. This model will be useful for oil and gas industries worldwide for accurate prediction of corrosion rate.

After more than 70 years of evolution, great achievements have been made in machine translation. Especially in recent years, translation quality has been greatly improved with the emergence of neural machine translation (NMT). In this article, we first review the history of machine translation from rule-based machine translation to example-based machine translation and statistical machine translation. We then introduce NMT in more detail, including the basic framework and the current dominant framework, Transformer, as well as multilingual translation models to deal with the data sparseness problem. In addition, we introduce cutting-edge simultaneous translation methods that achieve a balance between translation quality and latency. We then describe various products and applications of machine translation. At the end of this article, we briefly discuss challenges and future research directions in this field.

Occurrences such as the global climate change have presented critical challenges to humanity and necessitated studies into how greenhouse gas emissions can be minimized. One practical solution is the generation of power from renewable and sustainable sources; hence, tidal current energy which, however, also gives rise to the concept of fluid-structure interaction (FSI). The pressure and fluid flow aspects affect the structural deformations and the structural deformations in turn affect pressure and flow. This paper presents a perspective review of FSI based optimisation in tidal turbines with a focus on low-order aerodynamic, computational fluid dynamics (CFD) and structural modeling. It was acknowledged that, to aid humanity amidst the issue of using renewable or non-renewable sources of energy, practical solutions such as generating renewable energy from sustainable sources are effective. Tidal current energy was found to be one of the most reliable solutions but further studies regarding its practicality was advised.

Heterogeneous cellular networks (HCNs) are envisioned as a promising architecture to provide seamless wireless coverage and increase network capacity. However, the densified multi-tier network architecture introduces excessive intra- and cross-tier interference and makes HCNs vulnerable to eavesdropping attacks. In this article, a dynamic spectrum control (DSC)-assisted transmission scheme is proposed for HCNs to strengthen network security and increase the network capacity. Specifically, the proposed DSC-assisted transmission scheme leverages the idea of block cryptography to generate sequence families, which represent the transmission decisions, by performing iterative and orthogonal sequence transformations. Based on the sequence families, multiple users can dynamically occupy different frequency slots for data transmission simultaneously. In addition, the collision probability of the data transmission is analyzed, which results in closed-form expressions of the reliable transmission probability and the secrecy probability. Then, the upper and lower bounds of network capacity are further derived with given requirements on the reliable and secure transmission probabilities. Simulation results demonstrate that the proposed DSC-assisted scheme can outperform the benchmark scheme in terms of security performance. Finally, the impacts of key factors in the proposed DSC-assisted scheme on the network capacity and security are evaluated and discussed.

A 13-bit Time to Digital Converter is implemented using multiphase clock technique. Xilinx’s Virtex 5 FPGA platform is used to realize the TDC architecture. One PLL within the FPGA works as a clock synthesizer to multiply the reference clock to 500 MHz. Then the combination of PLL and DLL topologies are used to generate 16 phases of the clock, separated by 11.25°. Further, 16 phases are generated by inverting the first 16 phases. A resolution of 62.5 ps has been recorded. Measured INL and DNL are within 1 LSB. The present work is suitable for many critical applications due to its PVT insensitive and robust properties.

The toxicity and associated health risks of typical contaminated groundwater were evaluated using bioassays, the SOS/umu test and the micronucleus assay, with a comparison of identified risks based on bioassay and chemical methods. An analysis of 15 water extracts showed that a lifetime cancer risk (LCR) value of 10−6 was recorded for 47% of water extracts. These results indicated that some water extracts did not exhibit toxicity when analysed using one type of bioassay, yet they indicated high toxicity when analysed using another method. Our results also demonstrated that the LCR values from bioassays were generally greater (2.4-foldmax) than those derived from chemical analysis, a finding indicating that risks can be underestimated or false-negative results can be obtained when only chemical-based methods or even just one bioassay is used. This study suggests that the use of multiple bioassays should be considered to be an efficient method and a comprehensive method should be established for risk assessment. Our findings also suggest that groundwater and freshwater in the studied area might pose significant health risks and exhibit toxicity.

Sand deposition in pipelines during crude oil transportation is a serious industrial problem; these problems often lead to extra expenses in the course of transportation, causing a threat to the environment and economic damage. The intent of this study is to model the minimum condition required to transport sand particles as dispersed phase (Suspended particles) in flowing crude in pipelines. A mechanistic approach based on force balance and particle trajectory of Lagrangian Multiphase modeling was used to develop a model for determining the minimum transport condition for sand flowing in petroleum to avoid sand trapping along the bed of the pipeline. The model developed is a quadratic function of slip velocity and the findings was compared with experimental data and other three models and found to compete favorably. Consistency exists between the predicted outcomes and the experimental results with a relative error of 1.1%. This model will be useful for oil and gas industries worldwide for accurate prediction of critical suspending velocities of petroleum containing sand and other tiny particles to avoid deposition of particles along the pipeline and eliminate corrosion-related danger in the pipelines caused by the particles.

Sinomenine (SIN) is commonly used as part of rheumatoid arthritis (RA) therapy in China, but there is still no published evidence of the efficacy of SIN monotherapy. This work investigates the efficacy and safety of SIN in treating RA patients and analyzes the correlation between ornithine level and the alleviation of disease activity in RA patients. In this 24 week, randomized, placebo-controlled, double-blind clinical trial, people with mild to moderate RA were randomly assigned (1:1:1, stratified by hospital) to receive SIN (120 mg, twice daily), methotrexate (MTX) (10 mg per week), or SIN + MTX therapy. The primary outcome was the proportion of patients who achieved a 50% improvement in the American College of Rheumatology (ACR) criteria at week 24 and who showed improvement according to the clinical disease activity index (CDAI). In this prospective subgroup analysis, we also assessed whether the 24 week alterations of disease activity in the treatment group were significantly correlated to the levels of blood ornithine. Of the 135 enrolled participants, 38, 39, and 36 patients were treated with SIN, MTX, and SIN + MTX, respectively. In the SIN-treated group, 52.63% of patients achieved ACR50 after 24 weeks of treatment, which was comparable to the results in the MTX-treated and SIN + MTX-treated groups. Hepatic and gastrointestinal disorders were the main adverse events; however, the ratio of patients suffering from hepatic disorder in the SIN group (1/38) was much lower than that in the MTX (10/39) and SIN + MTX (8/36) groups. A total of 221 serum samples were collected at the four follow-up time points in the three treatments, and the levels of ornithine, citrulline, and arginine were obtained through ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS). The serum ornithine level decreased after the 24 week treatment along with a decrease in disease activity, and may reflect therapeutic responses with a sensitivity value of 80%. In conclusion, SIN revealed a comparable efficacy to MTX for treating RA patients, but with fewer side effects. In addition, the serum ornithine level was found for the first time to have a close correlation with the alleviation of RA, which shows the value of this measure as an assessment indicator of drugs in treating RA.

In this study, we used a network meta-analysis (NMA) to compare the effectiveness of medicines and supplements for idiopathic male infertility and to identify the best treatment. Medline, Excerpta Medica Database (EMBASE), Ovid, and China National Knowledge Infrastructure (CNKI), were searched for the period from January 1990 to June 2021 using the keywords “male infertility,” “medical therapy,” “supplement/nutrient therapy,” and related terms. Studies involving randomized controlled trials (RCTs) investigating medicines (mainly follicle-stimulating hormone (FSH), androgen, and clomiphene/tamoxifen) or supplements (mainly zinc, selenium, vitamin C or E, carnitine, coenzyme Q10 (CoQ10), or combined treatment) for idiopathic infertile men were selected for meta-analysis. Preferred reporting items for systematic reviews and meta-analysis (PRISMA) was used for data extraction, and a risk-of-bias tool and grades of recommendation, assessment, development, and evaluation (GRADE) system adapted to the NMA were employed to assess the quality of the evidence. The primary outcomes were live birth and spontaneous pregnancy rate (SPR). The secondary outcomes were sperm parameters (including concentration, progressive motility, and morphology) and side effects. In total, 65 RCTs involving 7541 men with sperm abnormalities but normal hormone levels were included. A total of 36 studies reported SPR but only three reported live birth rates. The quality of the included studies was found to be moderate to high. Compared with a placebo or being untreated, carnitine plus vitamins significantly improved SPR (relative risk (RR) = 3.7, 95% confidence interval (CI), 1.6–8.5); fatty acids significantly increased sperm concentrations (mean difference (MD) = 12.5 × 106 mL–1, 95%CI, 3.1 × 106–22.0 × 106); and selective estrogen receptor modulators (SERM) plus CoQ10 significantly improved sperm progressive motility (MD = 11.0%, 95%CI, 0.1%–21.9%) and normal sperm morphology (MD = 11.0%, 95%CI, 4.6%–17.4%). The most optimal intervention was carnitine plus vitamins and fatty acids for SPR and sperm concentrations, respectively, even after excluding trials at a high risk of bias. Compared with a placebo or being untreated, FSH (RR = 4.9, 95%CI, 1.1–21.3) significantly increased SPR, whereas SERM plus kallikrein increased sperm concentration (MD = 16.5 × 106 mL–1, 95%CI, 1.6 × 106–31.4 × 106), and SERM plus CoQ10 significantly improved sperm progressive motility (MD = 11.3%, 95%CI, 7.3%–15.4%) and normal morphology (MD = 11.2%, 95%CI, 5.4%–16.9%) in men with oligoasthenozoospermia (OA). In terms of side effects, fatty acids and pentoxifylline were associated with foul breath and/or a bad taste (RR = 8.1, 95%CI, 1.0–63.5) and vomiting (RR = 8.0, 95%CI, 1.0–63.0), respectively. In conclusion, the optimal treatment for male infertility for live birth is still unknown. Carnitine plus vitamins and FSH are likely to be better than other therapies in achieving successful spontaneous pregnancy in couples overall and in couples with men with OA, respectively. The efficacy of other treatments on pregnancy outcomes warrants further verification.

Shear and flexural failure are commonly known as the highest catastrophic failure mode as it never gives any earlier notice before the collapse. The most common shape in the structure of beams and girders is T-section. Therefore it will be more necessary to investigate the condition of these structures. In this research, the flexural behaviour of RC T-beams is investigated experimentally and analytically strengthened with Basalt Fiber Reinforced Polymer (BFRP). A symmetrical one-point static loading system is applied on RC T-beams superficially bonded with 45° degree, and 90° wrapping up to failure. The effects of both wrapping patterns of BFRP on RC T-beams were investigated for ultimate load carrying capacity, deflection, strain, and failure modes. The experimental results demonstrate that superficially bonded BFRP can enhance the flexural capacity and reduce the deflection of the beam significantly. Further, the results show that the most effective wrapping pattern was a 45° degree than 90°wrapping and without wrapping. Then the RC T- beam was modeled by using ABAQUS to validate the present experimental and analytical results. After a series of comparative studies, the analytical results fairly admit with the experimental results. In the end, this study surmised showing different cracking patterns and yield points of the beam with and without strengthening. It is hoped that the results of this study will be of considerable help for the strengthening of T- beams and structures.

Helium (He) is commercially produced from natural gas by low-temperature condensation. The process is energy extensive because of the extremely low He concentration (

Polybrominated diphenyl ethers (PBDEs) have widely been used for decades as flame retardants in a variety of products like plastics for building insulation, upholstered furniture, electrical appliances, vehicles, aircrafts, polyurethane foams, textiles, cable insulation, appliance plugs and various technical plastics in concentrations of 5-30%. However, PBDEs also act as endocrine disrupters, neurotoxins, and negatively affect fertility. In 2001, worldwide consumption of technically relevant penta-BDEs was still estimated at 7500 tons, octa-BDEs at 3790 tons, and deca-BDE at 56,100 tons, but 50-60% of this total volume are discharged into the environment via sewage sludge and its agricultural use alone. In addition, soils are ubiquitously contaminated by the gaseous or particle-bound transport of PBDEs, which today has its main source in highly contaminated electronic waste recycling sites. The emitted PBDEs enter the food chain via uptake by the plants’ roots and shoots. However, uptake and intrinsic transport behaviour strongly depend on crop specifics and various soil parameters. The relevant exposure and transformation pathways, transport-relevant soil and plant characteristics and both root concentration factors (RCF) and transfer factors (TF) as derivable parameters are addressed and quantified in this review. Finally, a simple predictive model for quantification of RCF and TF based on log KOW values and the organic content of the soil/lipid content of the plants is also presented., Umweltbundesamt, Projekt DEAL

Many proponents of organic farming claim that it is a sustainable alternative to conventional agriculture due to its reliance on natural agro-inputs, such as manure based fertilizers and organic pesticides. However, in this analysis we argue that although particular organic farming practices clearly benefit ecosystems and human consumers, the social context in which some organic farms develop, limit the potential environmental benefits of organic agriculture. Specifically, we argue that certified organic farming’s increased reliance on agro-inputs, such as organic fertilizers and pesticides, reduces its ability to decrease global water pollution. We review recent research that demonstrates the environmental consequences of specific organic practices, as well as literature showing that global organic farming is increasing its reliance on agro-inputs, and contend that organic farming has its own metabolic rift with natural water systems similar to conventional agriculture. We use a fixed-effects panel regression model to explore how recent rises in certified organic farmland correlate to water pollution (measured as biochemical oxygen demand). Our findings indicate that increases in the proportion of organic farmland over time increases water pollution. We conclude that this may be a result of organic farms increasing their reliance on non-farm agro-inputs, such as fertilizers.

Although mine fires and attempts to extinguish them have existed for as long as coal mining, there has so far been no reliable practical method developed for extinguishing mine fires burning for a long time under deep cover. A new ‘foamed backfilling’ method combines nitrogen-enhanced foam with non-combustible solids to create a fluid, slurry-like mixture, which is injected into the mine workings remotely through boreholes to extinguish a mine fire. When injected in the area of the fire, the foamed backfill material will smother the active fire, provide moisture, block ventilation and absorb heat. Nitrogen gas released as the bubbles decay and the foam dissipates creates an inert oxygen-deficient atmosphere to inhibit combustion. Finally, the non-combustible solid particles suspended in the foam will backfill the mine workings, rubble zones, burnt-out areas and fractures to block ventilation permanently after the foam dissipates. Thus, injection of foam-transported backfill material addresses all three legs of the fire triangle; heat is removed, oxygen is excluded and the fuel is isolated, which increases the odds of success. Economic benefits include the ability to use low-cost non-combustible materials derived from on-site sources or waste from other industries, low water consumption and wider borehole spacing.

Hydrogen and light hydrocarbon components are essential resources of the refinery. The optimization of the refinery hydrogen system and recovery of the light hydrocarbon components contained in the gas streams are key strategies to reduce the operating costs for sustainable development. Many research efforts have been focused on the optimization of single impurity hydrogen network, and the flowrates of the hydrogen sources and sinks are assumed to be constant. However, their flowrates vary along with the quality of crude oil and refinery processing plans. A general superstructure of multicomponent refinery hydrogen network is proposed, which considers four components, namely H2, H2S, CH4 and C 2 + , as well as the flowrate variations of hydrogen source and hydrogen sink. The mathematical model based on the superstructure is developed with objective functions, including the minimization of total annualized cost and the maximization of overall satisfaction of the hydrogen network. Moreover, the model considers the removal of hydrogen sulfide and the recovery of light hydrocarbon components (i.e., C 2 + ) in the optimization. To verify the applicability of the proposed mathematical model, a simplified industrial case study with four scenarios is solved. The optimization results show that the economic benefit can be maximized by considering both the direct reuse of gas streams from high-pressure separator (HP gas stream) and from low-pressure separator (LP gas stream) and the recovery of the light hydrocarbon streams. The fuzzy optimization method can be used to guide the optimal design of the refinery hydrogen system with multi-period variable flowrates.

As a new interdisciplinary field, synthetic biology has led to valuable innovations in the fields of medicine, chemistry, agriculture, energy and environment. In this paper, we systematically review the development status of global synthetic biology in the past six years, and make an in-depth benchmarking analysis of the field in China. With the aid of Scopus and SciVal, we analyze the scholarly output of synthetic biology in the world and individual countries, including publication distribution, popular journals and eminent institutions. Furthermore, the research focus and concepts, citation impact and collaborations are also examined using numerical index methods such as the field-weighted citation impact (FWCI) and relative activity index (RAI), showing the differences between data more intuitively. This study aims to offer a comprehensive understanding of the research status of synthetic biology in China and the world, offering a benchmarked overview of the results as a reference to guide the development of this field in the future.

Ammonium bisulfate (ABS) is a viscous compound produced by the escape NH3 in the NO reduction process and SO3 in the flue gas at a certain temperature, which can cause the ash corrosion of the air preheater in coal-fired power plants. Therefore, it is essential to study the formation temperature of ABS to prevent the deposition of ABS in air preheaters. In this paper, the SO3 reaction kinetic model is used to analyze the SO3 generation process from coal combustion to the SCR exit stage, and the kinetic model of NO reduction is used to analyze the NH3 escape process. A prediction model for calculating the ABS formation temperature based on the S content in coal and NO reduction parameters of the selective catalytic reduction(SCR) is proposed, solving the difficulty of measuring SO3 concentration and NH3 concentration in the previous calculation equation of ABS formation temperature. And the reliability of the model is verified by the actual data of the power plant. Then the influence of S content in coal, NH3/ NOx molar ratio, different NOx concentrations at SCR inlet, and NO removal efficiency on the formation temperature of ABS are analyzed.

This paper sheds the light on the future of green hydrogen in Tunisia. So, a detailed economic assessment and evaluation of the Levelized Hydrogen Cost (LHC) and the Net Profit (NP) of a Photovoltaic (PV) Hydrogen Refueling Station (HRS) are presented and discussed. Tunisia is characterized by its high PV potential which makes the production of electricity from solar energy an effective alternative source. However, due to the regulations and issues related to the connection of medium PV scale to the power grid, the energy produced from renewable sources (RS) is still less than 3% of the total produced electricity. On the other hand, the price of hydrocarbon fuels is still increasing. The gap between production and total demand in hydrocarbons has created a deficit in the primary energy balance. Therefore, the production of hydrogen from solar energy for refueling Fuel Cell Vehicles (FCV)s consists of a promising solution to boost the development of the country, reduce hydrocarbon fuels consumption, and protect the environment. The sizing of a small PV-HRS to produce 150 kg of hydrogen per day shows the necessity to install PV systems with a total Direct Current (DC) capacity of 1.89 MWp. The Initial Cost (IC) analysis shows that while the PV system cost represents 48.5% of the total IC, the IC of electrolysers represents 41%. The storage system cost is approximately equal to 3.2% of the total IC. The LHC is equal to 3.32€/kg with a total IC of 2.34 million €.

China’s energy system requires a thorough transformation to achieve carbon neutrality. Here, leveraging the highly acclaimed The Integrated MARKAL-EFOM System model of China (China TIMES) that takes energy, the environment, and the economy into consideration, four carbon-neutral scenarios are proposed and compared for different emission peak times and carbon emissions in 2050. The results show that China’s carbon emissions will peak at 10.3–10.4 Gt between 2025 and 2030. In 2050, renewables will account for 60% of total energy consumption (calorific value calculation) and 90% of total electricity generation, and the electrification rate will be close to 60%. The energy transition will bring sustained air quality improvement, with an 85% reduction in local air pollutants in 2050 compared with 2020 levels, and an early emission peak will yield more near-term benefits. Early peak attainment requires the extensive deployment of renewables over the next decade and an accelerated phasing out of coal after 2025. However, it will bring benefits such as obtaining better air quality sooner, reducing cumulative CO2 emissions, and buying more time for other sectors to transition. The pressure for more ambitious emission reductions in 2050 can be transmitted to the near future, affecting renewable energy development, energy service demand, and welfare losses.

Thermoacoustics is about conversion between thermal and acoustical energies to provide alternative green technology for power cycle and cooling system. The oscillatory flow across porous structure inside the system is playing the role of energy conversion between the acoustic wave and the surface of the porous structure. Better understanding of fluid dynamics of oscillatory flow inside thermoacoustic system is therefore important for the thermoacoustic based energy conversion system. This paper presents the ‘entrance’ and ‘exit’ effects of the oscillatory flow within a parallel-plate structure that is placed inside a standing-wave thermoacoustic environment. Two-dimensional SST k-ω CFD models which were validated using experimental data and theoretical predictions were used for this investigation. Two different operating frequencies of 14.2 Hz and 23.6 Hz were studied for flow with five different amplitudes that were represented using drive ratios of 0.3%, 0.83%, 1.5%, 2.1% and 3%. These correspond to cases with Reynolds numbers between 5936 and 62926. Due to the cyclic nature of the flow, a region defined as an ‘exit’ region was observed in addition to the usual ‘entrance’ region and the fully developed region for flow inside a channel. The change of shape of velocity profiles from the ‘m’ shape profile, to the ‘slug-like’ profile and ‘parabolic-like’ profile was discussed in relation to the ‘entrance’ and ‘exit’ effects on flow inside the channel. The ‘entrance’ and ‘exit’ effects become bigger as drive ratio increases. The effect of ‘entrance’ and ‘exit’ are slightly reducing as frequency increases from 14.2 Hz to 23.6 Hz. This may be related to the shorter travel distance of fluid as the frequency increases. The results shown in this paper suggest that the flow within a 200 mm parallel-plate structure should be treated as developing flow especially for flow with low resonance frequency at drive ratio higher than 1%.

Mesoscale bubbles exist inherently in bubbling fluidized beds and hence should be considered in the constitutive modeling of the drag force. The energy minimization multiscale bubbling (EMMS/bubbling) drag model takes the effects of mesoscale structures (i.e., bubbles) into the modeling of drag coefficient and thus improves the coarse-grid simulation of bubbling and turbulent fluidized beds. However, its dependence on the bubble diameter correlation has not been thoroughly investigated. The hydrodynamic disparity between homogeneous and heterogeneous fluidization is accounted for by the heterogeneity index, Hd, which can be affected by choice of bubble diameter correlation. How this choice of bubble diameter correlation influences the model prediction calls for further fundamental research. This article incorporated seven different bubble diameter correlations into EMMS/bubbling drag model and studied their effects on Hd. The performance of these correlations has been compared with the correlation used previously by EMMS/bubbling drag model. We found that some of the correlations predicted lower Hd by order of a magnitude than the correlation used by the original EMMS/bubbling drag. Based on such analysis, we proposed a modification in the EMMS drag model for bubbling and turbulent fluidized beds. A computational fluid dynamics (CFD) simulation using two-fluid model with the modified EMMS/bubbling drag model was performed for two bubbling and one turbulent fluidized beds. Voidage distribution, time averaged solid concentration and axial solid concentration profiles were studied and compared with the previous version of the EMMS/bubbling drag model and experimental data. We found that the right choice of bubble diameter correlations can significantly improve the results for CFD simulations.

Accident prevention on the manufacturing shop floor is essential. This paper aims to develop a proximity warning system capable of reducing accidents on the manufacturing shop floor, by notifying employers of any possible danger within the workplace. The system consists of an ultrasonic sensor, Arduino microcontroller, alarm system and an easy to understand user interface that can detect and alert workers within the danger zone. The system was developed using the Unified Modelling Language, python programming language and the Arduino software. Preliminary test conducted on volunteer participants revealed that the system is easy to use and provides real-time easy-to-understand audio and visual feedback to workers. The system is useful for reducing accidents on shop floors.

Abstrct A composite Air Health Index (AHI) is helpful for separately emphasizing the health risks of multiple stimuli and communicating the overall risks of an adverse atmospheric environment to the public. We aimed to establish a new AHI by integrating daily mortality risks due to air pollution with those due to non-optimum temperature in China. Based on the exposure-response (E-R) coefficients obtained from time-series models, the new AHI was constructed as the sum of excess mortality risk associated with air pollutants and non-optimum temperature in 272 Chinese cities from 2013 to 2015. We examined the association between the “total AHI” (based on total mortality) and total mortality, and further compared the ability of the “total AHI” to predict specific cardiopulmonary mortality with that of “specific AHIs” (based on specific mortalities). On average, air pollution and non-optimum temperature were associated with 28.23% of daily excess mortality, of which 23.47% was associated with non-optimum temperature while the remainder was associated with fine particulate matter (PM2.5) (1.12%), NO2 (2.29%,), and O3 (2.29%). The new AHI uses a 10-point scale and shows an average across all 272 cities of 6 points. The E-R curve for AHI and mortality is approximately linear, without any thresholds. Each one unit increase in “total AHI” is associated with a 0.84% increase in all-cause mortality and 1.01%, 0.98%, 1.02%, 1.66%, and 1.71% increases in cardiovascular disease, coronary heart disease, stroke, respiratory diseases, and chronic obstructive pulmonary disease mortality, respectively. Cause-specific mortality risk estimates using the “total AHI” are similar to those predicted by “specific AHIs”. In conclusion, the “total AHI” proposed herein could be a promising tool for communicating health risks related to exposure to the ambient environment to the public.

Enhancing the torsional capacity of reinforced concrete (RC) beams while maintaining reasonably economic and efficient cross-sections poses a practical challenge in the design of such elements. Thus, developing and testing economically viable reinforcing techniques for enhancing the torsional capacity of RC beams is a significant aspect. Among these techniques is the continuous spiral reinforcement system that has shown promising results in enhancing the torsional capacity of rectangular RC elements. In this study, the role of continuous rectangular spiral stirrups, as a transverse reinforcement with a controllable pitch (P) and inclination angle (θ), in enhancing the torsional behavior of rectangular solid and hollow RC beams has been investigated experimentally. The applied torque was directed to lock the spirals for all specimens. The experimental program of this investigation included testing of ten specimens of normal strength RC beams; two of which were solid with closed and spiral rectangular stirrups. While the rest of specimens were hollow specimens included one beam reinforced by closed stirrups and seven beams reinforced by rectangular spiral stirrups with different reinforcing ratios. Different variables were considered to develop a wide range of the beams’ reinforcing scenarios. This includes stirrups type (conventional closed stirrups and rectangular spiral stirrups), inclined stirrups ratio, pitch, inclination angle and finally the longitudinal reinforcement ratio. In addition, a three-dimensional finite element model using ANSYS-15.0 was developed to examine the capability of the model to capture the observed torsional behavior of the experimentally tested beams. The obtained results showed that using inclined spiral rectangular stirrups in reinforcing RC solid and hollow beams greatly enhanced the torsional capacity by about 16% and 18%, respectively compared to using the conventional closed stirrups. Moreover, the results showed that using that technique leads to higher twist- angles, more ductile failure and increased strain energy by about 27% and 16% for solid and hollow beams, respectively. Lastly, the comparison between the results obtained from numerical model and experimental results showed good agreement and thus the numerical model can be used to extend the experimental work for investigating different reinforcing schemes.

As wearable microelectronics become more ubiquitous, and the size and power requirements of such devices decrease, there is increasing research interest in harnessing power from ambient environmental sources through embedded systems as alternative to battery replacements. Accordingly, a multimodal hybrid piezo-electromagnetic insole energy harvester (PEM-IEH) has been presented in this paper as a means to reclaim the biomechanical energy wasted in the surroundings during daily walking. The hybrid device consists of two piezo-ceramic wafer plates, two magnets, and two wound coils. The designed harvester has been simulated, fabricated and experimentally validated. From the frequency response, the hybrid harvester exhibits four resonant frequencies concentrated around 8, 25, 50, and 51 Hz. A maximum combined power of 1400 µW is generated across the optimal load resistances of upper and lower electromagnetic generators at first resonant frequency (8 Hz) under 0.5 g base acceleration, and a 269 µW peak power is obtained across the optimum load resistances of the upper and lower piezoelectric generators at 4th resonance (51 Hz) under 0.5 g. The miniature (46.8 cm3) and lightweight (43.3 g) harvester was incorporated into the sole of an adult-sized commercial shoe, and has been shown to be able to charge a 100 µF capacitor, up to 2.4 Volt within approximately 10 min of slow jogging. The capacitor charging performance presents a remarkable potential application of the harvester in development of micro-power monitoring sensors and wearable microelectronic gadgets where batteries pose a practical bottleneck.

Digital technologies had an effect on people's lives. The majority of these digital devices rely on cloud storage to meet their memory needs. Hundreds of thousands of images, videos, and audio files are being transferred to cloud storage. Thousands of people around the world access these media every second. Unauthorized access to these media must be avoided. One of the weak points for data breaches is the user-end encryption. This paper suggests a strategy for improving cloud data protection by combining the AES and blowfish encryption and decryption algorithms. AES-256 is used as the first layer, followed by blowfish as the second layer, in the hybrid solution. The output of the first layer is input to the second layer and the final result is analyzed. The proposed method also discusses other combined approaches such as AES with other traditional algorithms but the proposed method gives significant results compared to other approaches.

Fiber Optic Network is an advanced and modern system technology, which is used in sending pulses of laser light inside a glass of fiber over long distances, widely used in every environment with various sorts of applications in a different field. It is well-known that the main material of fiber optics is glass, therefore it is typical that the temperature can affect the glass during the thermal expansion. This effect will be applied to the properties of the optical components such as refractive index, radius curvature of the fiber optics layers, and also there is an effect on the data transfer through the fiber optics network units. In this paper, the effect of temperature degree on the optical signal and the functions of the fiber optic network will be simulated, measured, and analyzed. The result will be discussed and the conclusion will show the serious points of thermal effects on the optical signal of a fiber-optic network.

Acoustic properties play an important role in the identification of natural gas hydrate resources, the estimation of their potential yield and the evaluation of soil stabilisation during exploration. Physical properties, such as hydrate saturation, porosity and clay content, are dominant factors that affect the acoustic properties of sediments. When considering these properties, the modified Biot–Gassmann theory of Lee (BGTL), the effective-medium theory (EMT) and the Frenkel–Gassmann equation (FG) are adopted to show the characteristics of compressional and shear wave velocities due to variation of the physical properties of different sediments. The results show that hydrate saturation has the highest sensitivity in the three models, followed by the porosity and clay content. To evaluate the applicability of different models, the data from two case studies are compared – actual survey data from the site995 stations and 2L-38 logging. The results indicate that the BGTL and EMT models are more suitable for hydrate-bearing sediments with a hydrate saturation less than 10%, a clay content of 50–70% and a porosity of 60–70%, while the FG model is more suitable for hydrate-bearing sediments with a hydrate saturation of 30–70%, a clay content of 30–60% and a porosity of 30–50%.

Aromatics are traditionally produced by the catalytic reforming of naphtha. However, with the demand of aromatics increasing and the reserves of petroleum resources declining, measures should be made to reduce the dependence of aromatics production on petroleum resources. Methanol-to-aromatics is proved to be an effective way to replace traditional naphtha-to-aromatics path. In order to compare the economic and environmental performance of aromatics production from naphtha and methanol, this paper carries out an emergy evaluation for each system by sorting out the simulation and literature data. Based on the emergy data collected, the emergy indices of each system are calculated. The results show that the sustainabilities of methanol-to-aromatics systems are higher than that of the naphtha-to-aromatics system, indicating the advantages of aromatics production from methanol. Among the methanol-to-aromatics systems, the aromatics from biomass-methanol system has the highest sustainability, indicating that the biomass based methanol-to-aromatics system is worth promoting. The sustainability indexes of methanol-to-aromatics systems based on coal and coke oven gas are less than 1, which means unsustainable. Meanwhile, the sustainability of natural gas based system is slightly higher than 1. The economic and environmental benefits of these systems can be optimized by improving resource utilization and reducing investment costs. Furthermore, the combination of different raw materials for methanol production should be considered.

Natural gas hydrates, as a new energy source, are attracting more and more attention. Safe and efficient exploitation has become one of the hot issues in current studies. In order to investigate the creep behaviour of sediments containing methane hydrates, a series of triaxial compression tests and creep tests was conducted under various conditions. First, stress–strain curves were drawn, and then the failure strength of the sediments was obtained. Next, on the basis of creep tests, the creep curves were recorded. The results showed that the attenuation- and steady-creep stages always existed during creep, but the acceleration-creep stage just appeared under higher-temperature and higher-stress conditions. The creep test results indicated that the confining pressure, temperature and stress level affected the creep characteristics of sediments, such as the initial strain ε 0, the rheological initial time t m, the rheological initial strain ε m, the failure time t f and the failure strain ε f. The findings suggested that, during the creep tests, more hydrate dissociation accelerated the damage to the sediments’ strength under higher stress level, temperature or confining pressure.

Spinal cord injury (SCI) is a tremendous disaster in a person’s life. It interrupts the brain–body neuronal circuits, resulting in functional deficits. Pathogenesis of SCI is a progressive and comprehensive event. In clinical trials, attempts to promote nerve regeneration and functional recovery after SCI have met with failures. Recently, with the development of transcriptome sequencing and biomaterials, researchers have struggled to explore novel efficient therapeutic treatments for SCI. Here, we summarize the recent progress that has been made in SCI repair based on the lesion microenvironment, neural circuits, and biomaterial scaffolds. We also propose several important directions for future research, including targeted-microRNA therapy, blood vessel interventions, and multiple treatment combinations. In short, we hope this review will enlighten researchers in the field and pave the way for SCI therapy.

Due to its unique advantages, which include minimal invasiveness and relative clinical safety, phototherapy is considered to be a promising approach for cancer treatment. However, the treatment efficacy of phototherapy is often restricted by the limited depth of light penetration and the low targeting effect of phototherapeutic agents. The emergence of light-responsive nanomaterials offers a possible approach to achieve enhanced phototherapy potency. This review summarizes the progress in biomedical applications of light-responsive nanomaterials for cancer therapy, which include photothermal therapy (PTT), photodynamic therapy (PDT), light-responsive molecule delivery, and light-controlled combination therapy. Future prospects are also discussed. This review aims to demonstrate the significance of light-responsive nanomaterials in cancer therapy and to provide strategies to expand the applications of phototherapy.

Octane and p-xylene are common components in crude gasoline, so their separation process is very important in petroleum industry. The azeotrope and near azeotrope are often separated by extractive distillation in industry, which can realize the recovery and utilization of resources. In this work, the vapor-liquid equilibrium experiment was used to obtain the vapor-liquid equilibrium properties of the difficult separation system, and on this basis, the solvent extraction mechanism was studied. The mechanism of solvent separation plays a guiding role in selecting suitable solvents for industrial separation. The interaction energy, bond length and charge density distribution of p-xylene with solvent are calculated by quantum chemistry method. The quantum chemistry calculation results and experiment results showed that N-Formylmorpholine is the best solvent among the alternative solvents in the work. This work provides an effective and complete solvent screening process from phase equilibrium experiments to quantum chemical calculation. An extractive distillation simulation process with N-Formylmorpholine as solvent is designed to separate octane and p-xylene. In addition, the feasibility and effectiveness of the intensified vapor recompression assisted extraction distillation are also discussed. In the extractive distillation process, the vapor recompression-assisted extraction distillation process is globally optimal. Compared with basic process, the total annual cost can be reduced by 43.2 %. This study provides theoretical guidance for extractive distillation separation technology and solvent selection.

Decreasing the freshwater prices is considered a big concern within the desalination industry. The goal of this study is to determine the best reverse osmosis desalination system powered by photovoltaic or wind turbine in Ras-Gharib City, Egypt. The system is planned to produce 0.5 m3//hr of potable water. The techno-economic analysis is applied using SAM 2018.11.11 r4 simulation package. The results show that electricity bill using solar or wind energy is less than that in case of using convention energy systems. Based on simulation findings, the proposed photovoltaic system capacity is capable of generating water at a levelized energy cost of 3.95 cent$/kWh, compared to 9.5 cent$/kWh for wind system. The cost of one meter cubic of purified water using solar photovoltaic system is 0.08 $ while the cost is 0.19 $ using wind turbine system. Here, solar photovoltaic desalination system is the best choice system for this case study.