Aluminum nitride has been widely used as heat-management material for large-scale integrated circuits and semiconductor packages because of its excellent insulation, high thermal conductivity, low dielectric constant and loss, similar expansion coefficient to that of silicon, and non-toxicity. However, the increase of oxygen content caused by the hydration of aluminum nitride powder during storage often decreases the thermal conductivity of aluminum nitride ceramics. In this work, we propose an approach for preparing high-thermal-conductivity AlN ceramics via octyltrichlorosilane-modified AlN powder. The octyltrichlorosilane reacted with the hydroxyl group on the surface of the AlN powder forming a siloxane protective layer. The protective layer not only enhanced the water contact angle of AlN powder from 34.8° to 151°, but also ensured the phase of AlN powder did not change in the distilled water at 25 °C for 72 h. High-thermal-conductivity AlN ceramics up to 186 W·m−1·K−1 were succes... [more]

The core excitation saturation and vibration caused by DC bias are one of the important considerations in the design of high-frequency transformer (HFT). This paper studies the electromagnetic vibration characteristics of DC biased HFT with different winding structures. The vibration mechanism of iron core and winding under DC bias is analyzed. The optimal topology size of HFT is determined by area product (AP) method. In addition, the electromagnetic vibration multi-physical coupling model of a 500 V HFT under DC bias is established. At the same time, the electromagnetic vibration characteristics of interleaved winding and continuous winding of HFT are compared. The research shows that the current fluctuation of interleaved winding is smaller than that of continuous winding because of its ability to withstand impulse voltage. In addition, the average loss and maximum vibration displacement of HFT with entanglement winding are reduced in different degrees. The above research rules have... [more]

This paper investigates the failure of a regulating valve stem in a petrochemical plant, which was mainly caused by vibration fatigue under small opening conditions. The fractured valve stem was analyzed using macroscopic analysis, chemical composition analysis, mechanical property analysis, metallographic analysis, fracture surface observation, and energy spectrum analysis. Additionally, fluid-structure interaction (FSI) modal analysis was used to investigate the failure of the regulating valve. The results indicate that the valve opening had a direct impact on the vibration of the valve body, which, when operated at small openings, led to fatigue fracture at the step of variable cross-section. The paper suggests a smooth transition treatment be performed at the variable cross-section of the valve stem to avoid stress concentration. Although this study is limited to a specific case, it provides valuable insights for the failure analysis of valves operating at small openings.

Thermally conductive silicone rubber (TCSR)-based thin sheets with low thermal resistance and high electrical insulation properties have been widely used in thermal management applications in the electronic and energy storage fields. The low thermal resistance is mainly attributed to the sheets’ small thickness. In order to further decrease the sheets’ thermal resistance, it is necessary to decrease their thickness. However, the sheets mostly have a thickness of at least 0.20 mm, and it is still a challenge to decrease the thickness to less than 0.10 mm mainly due to the difficulty of smooth calendering through a narrow roll-to-roll gap on calenders. Here, a low-viscosity calendering method has been developed to prepare TCSR-based ultra-thin sheets. The sheets present unprecedentedly small thickness (~0.08 mm), low thermal resistance (0.87 cm2K/W), high tensile strength (~8 MPa), high flexibility, high electrical resistance (>1014 Ω·cm), and high thermal dissipation (>30 °C decrease in... [more]

In this work, the performance of medium-pressure UV/peracetic acid (MPUV/PAA/H2O2) was explored on removing reactive black 5 (RB5), aniline (ANL), and polyvinyl alcohol (PVA), three typical refractory contaminants in printing and dyeing wastewater, compared with MPUV/H2O2. MPUV/PAA/H2O2 showed 75.0, 44.9, and 57.7% removals of RB5, ANL, and PVA, respectively, within 5 min. The removal of RB5 increased from 68.98 to 91.2%, with pH increasing from 6 to 9, while the removals of ANL and PVA were much less pH-dependent. Quenching experiment results indicated that UV photolysis and radical (i.e., •OH and R-C•) oxidation contributed to RB5 removal, while PAA showed high activity in the oxidation of ANL. For PVA, •OH oxidation and UV photolysis were likely the main mechanisms. The coexisting natural organic matter had a negative effect on the degradation of RB5 and PVA. In addition, MPUV/PAA/H2O2 could effectively degrade those pollutants without increasing the toxicity. This work provides a t... [more]

Functional Food demonstrates a wide spectrum of physiological benefits and reduces the risks of several health hazards to consumers; however, its appearance is similar to conventional food and is considered as part of the regular diet [...]

The pressing problems of water scarcity in many parts of the planet make water desalination one of the technological solutions for guaranteeing the fresh water supply. However, desalination processes require high energy consumption, mainly provided by fossil fuels. The integration of renewable energy sources into desalination processes is a promising option for decarbonizing the desalination sector. As most water-scarce regions with access to seawater frequently have high solar irradiation levels, it seems appropriate to exploit the sun to power the desalination process. This work presents the assessment of two integrated solar power and desalination systems regarding efficiency and water production. Two desalination processes (multi-effect distillation and reverse osmosis) are studied for potential coupling with the combined cycle of a central receiver solar plant to produce electricity and freshwater. In the case of the multi-effect distillation plant, it is integrated by replacing t... [more]

The fig tree (Ficus carica L.) was one of the first domesticated trees. In 2019, the world’s fig fruit production was estimated at 1153 tons. However, fig leaves are not utilized, resulting in copious quantities of bio-waste. To identify promising fig tree varieties, hydroethanolic extracts were prepared from the leaves of five fig tree varieties (Pasteliere—PA, Longue d’Aout—LA, Dauphinie—DA, Boujassote Noire—BN, and Marseille—MA). The variety with the highest concentration of organic acids was BN (146.5 mg/g dw), while glucose, fructose, and sucrose were the predominant sugars across all varieties. All extracts present α-tocopherol as the prevalent tocopherol isoform (above 78%), while PUFA fatty acids were predominant, ranging from 53% to 71% of total fatty acids. BN showed moderate antioxidant activity (EC50 0.23 ± 0.01 mg/mL), while the DA variety presented promising cytotoxicity against the tumor AGS and MCF-7 cell line (GI50 158 ± 13 and 223 ± 21 μg/mL) and especially in the inh... [more]

Kenaf or Hibiscus cannabinus is an annual herbaceous crop that grows well in temperate regions with high rainfall and abundant solar radiation. This Malvaceae member is famously known for its high-quality fibre that is directly retrieved from its dried stem materials and is useful in various industries, mainly in paper and pulp, bio-composite, textiles and manufacturing. With recent discoveries, kenaf can now be regarded as a multipurpose crop as its usage has been extended beyond its traditional applications, which include applications within the medicinal, pharmaceutical and food industries since its extracts possess several bioactivities that include anticancer, antimicrobial, antihypertensive, antidiabetic and antithrombotic abilities along with many more. The plant’s versatile applications and pharmaceutical activities come from its different plant parts such as its leaves, seeds, flowers and stems. This demonstrates that kenaf can also be safely regarded as a zero-waste crop, whi... [more]

This paper studied laser induced thermal-crack propagation (LITP) dicing of a glass-silicon double-layer wafer with high scanning speed. A defocusing continuous laser was used in the experimental system as the volumetric heat source for the glass layer and the surface heat source for the silicon layer. Based on the principle of thermal-crack propagation, the commercial software ABAQUS was used on the simulated analysis, and the results of temperature field and thermal stress field distribution with high and low speed were compared. The experiment was executed in accordance with the simulation parameters. The surface morphology of the cut section was described by optical microscopy and a profilometer, and combined with the results, the non-synchronous propagation process of the crack under high speed scanning was revealed. Most importantly, the scanning section with a nanoscale surface roughness was obtained. The surface roughness of the silicon layer was 19 nm, and that of glass layer... [more]

Inorganic elements in crude oil have been used in the reconstruction of the sedimentary environment and oil−oil (source) correlations; however, the effect of biodegradation on these elements has not been investigated sufficiently. In this study, 14 crude oils from the Miaoxi Sag of the Bohai Bay Basin, eastern China, were analyzed using molecular markers, trace elements, and major elements to determine the effect of biodegradation on inorganic elements. The molecular markers indicated that the oils are in the low maturity stage and are derived from similar parent materials in lacustrine source rocks. The high-sulfur oil came from a more reductive and saltier environment compared with the low-sulfur oil. The oils were subjected to varying degrees of biodegradation. The concentrations of Mg, Ca, Mn, Fe, Be, Sc, Rb, Sr, Zr, Pb, Th, and U increased significantly throughout the biodegradation process, while the concentrations of Na, K, Ti, Al, Cr, Zn, Cs, Nb, Ba, Hf, and Tl increased consid... [more]

The effective measuring range of an electromagnetic wave resistivity instrument used in logging while drilling (LWD) is small, and the resistivity measurement is greatly influenced by the dielectric constant, especially in high-dielectric-constant formations. In this paper, the response characteristics of the instrument under a high dielectric constant are investigated by a numerical simulation algorithm, and the resistivity conversion method is determined. The results show that the higher the working frequency of the electromagnetic wave resistivity instrument while drilling, and the greater the formation of background resistivity, the greater the influence of the dielectric constant on the logging response. The existence of the dielectric constant will cause the phase shift and amplitude attenuation of the measured signal to migrate, and this migration is proportional to the formation resistivity and the dielectric constant. According to this rule, the resistivity−permittivity respon... [more]

Our world still greatly relies on the combustion process to convert fuel into power and heat for purposes such as gas turbines, internal combustion (IC) engines, jet engines, rockets, boilers, and furnaces [...]

One of China’s ambitious hydrogen strategies over the past few years has been to promote fuel cells. A number of hydrogen refueling stations (HRSs) are currently being built in China to refuel hydrogen-powered automobiles. In this context, it is crucial to assess the dangers of hydrogen leaking in HRSs. The present work simulated the liquid hydrogen (LH2) leakage with the goal of undertaking an extensive consequence evaluation of the LH2 leakage on an LH2 refueling station (LHRS). Furthermore, the utilization of an air curtain to prevent the diffusion of the LH2 leakage is proposed and the defending effect is studied accordingly. The results reveal that the Richardson number effectively explained the variation of plume morphology. Furthermore, different facilities have great influence on the gas cloud diffusion trajectory with the consideration of different leakage directions. The air curtain shows satisfactory prevention of the diffusion of the hydrogen plume. Studies show that with t... [more]

Photovoltaic (PV) systems are becoming increasingly prevalent worldwide, particularly in power distribution networks. However, their intermittency and integration into distribution networks can have adverse effects. This study investigates the impact of large-scale solar integration into a typical Malaysian power grid network, focusing on voltage stability, short circuits, and power loss under peak and no-load conditions. Using Digsilent Power Factory software, static and dynamic power flow analyses were performed on a network consisting of two 132/11 kV transformers, an 11 kV busbar, and 112 loads served through eight feeders. Solar PV of 100 kW was integrated into each node, and the maximum allowable solar grid connection level was determined. The static results show that there were no violations in no-load conditions at 100 kW PV penetration. However, during peak load, there were violations at 0% PV penetration, but by increasing the level of solar grid connection to 60% (60 kW), th... [more]

Shape memory nanocomposites are excellent smart materials which can switch between a variable temporary shape and their original shape upon exposure to external stimuli such as heat, light, electricity, magnetic fields, moisture, chemicals, pH, etc. Numerous nanofillers have been introduced in shape memory polymers such as carbon nanotubes, graphene, nanodiamonds, carbon nanofibers, etc. Among nanocarbons, graphene has attracted research interest for the development of shape memory polymer/graphene nanocomposites. Graphene is a unique one-atom-thick two-dimensional nanosheet of sp2-hybridized carbon atoms. Graphene has been used as an effective nanofiller in shape memory polymeric nanocomposites owing to its remarkable electrical conductivity, flexibility, strength, and heat stability. Thermoplastics as well as thermoset matrices have been used to form the shape memory nanomaterials with graphene nanofiller. In shape memory polymer/graphene nanocomposites, their shape has been fixed ab... [more]

: Preclinical studies on radiofrequency (RF) cardiac ablation (RFCA) use very small temperature sensors in specific positions in the tissue subjected to RF heating. Despite the sensors’ small size, the proximity to the ablation electrode and the extremely high thermal gradient around the electrode means that the presence of the temperature sensors could distort the temperatures recorded. Our objective was to assess the thermal impact of intra-tissue temperature sensors during RFCA.: 3D RFCA models were built including different temperature sensors based on fiber optics and T-type thermocouples. Constant power ablation was simulated for 10 s.: The results showed that the disturbance caused by the presence of the T-type thermocouples was considerably greater (one order of magnitude) than that caused by the optical fibers. The closer the sensor was to the ablation electrode, the greater the greater the disturbance was and the more it increased with time in sensors more than 3 mm deep. The... [more]

Curved bladelets on wind turbine blades play an important role in improving the performance and efficiency of wind turbines. Implementing such features on the tip of wind turbine blades can improve their overall aerodynamic characteristics by reducing turbulence and loading without hindering lift generation and overall efficiency, thus leading to increased energy capture and reduced costs over the life of the turbine. Subjecting the integrated blade tip to optimization procedures can maximize its beneficial contribution to the assembly in general. Within this context, a systemic workflow is proposed for the optimization of a curved bladelet implemented on a wind turbine blade. The approach receives input in the form of an initial tip geometry and performs improvements in two distinct stages. Firstly, shape optimization is performed directly on the outer shape to enhance its aerodynamic properties. Subsequently, the topology of its interior structure is refined to decrease its mass whil... [more]

Alarm systems are essential to the process safety and efficiency of complex industrial facilities. However, with the increasing size of plants and the growing complexity of industrial processes, alarm flooding is becoming a serious problem and posing challenges to alarm systems. Extracting alarm patterns from an alarm flood database can assist with an alarm root cause analysis, decision support, and the configuration of an alarm suppression model. However, due to the large size of the alarm database and the problem of sequence ambiguity in the alarm sequence, existing algorithms suffer from excessive computational overhead, incomplete alarm patterns, and redundant outputs. In order to solve these problems, we propose an alarm pattern extraction method based on the improved PrefixSpan algorithm. Firstly, a priority-based pre-matching strategy is proposed to cluster similar sequences in advance. Secondly, we improved PrefixSpan by considering timestamps to tolerate short-term order ambig... [more]

Organic waste management is an important concern for both industries and communities. Proper management is crucial for various reasons, such as reducing greenhouse gas emissions, promoting sustainability, and improving public health. Composted manure is a valuable source of nutrients and organic matter that can be used as a soil amendment in agriculture. Some important benefits of using composted manure in agriculture include: improves soil fertility, enhances soil structure, reduces soil erosion, suppresses plant diseases, and reduces reliance on synthetic fertilizers. Composted manure represents one of the most effective methods of organic waste valorization. Its macronutrients and micronutrients content can increase plant yield, without any reported negative or toxic effects on the soil and plants at various application rates. However, improper use of farmyard manure can have negative effects on the environment, such as air pollution from greenhouse gas emissions, soil acidification... [more]

Chemical investigations of L. stoechas subsp. luisieri and L. pedunculata essential oils were analyzed by GC-MS, and the antimicrobial activity was performed against bacteria and fungi isolated from food sources. The cytotoxicity of the essential oil was performed in NHDF cells using the MTT method. According to the results, the main compounds of L. stoechas subsp. luisieri essential oil were trans-α-necrodyl acetate (40.2%), lavandulyl acetate (11%), and trans-α-necrodol (10.4%), while fenchone (50.5%) and camphor (30.0%) in L. pedunculata essential oil. The antifungal activity of essential oils was confirmed with MIC values ranging from 1.2 to 18.7 µL/mL; for bacteria, it ranged from 4.7 to 149.3 µL/mL. Both the Lavandula species tested showed low or equal MIC and MBC/MFC values for L. stoechas subsp. luisieri essential oil, revealing greater efficacy in antimicrobial activity. The L. stoechas subsp. luisieri essential oil revealed cytotoxic effects (30 ± 2% of cell viability) in NHD... [more]

Accurate stress field calculation of the casing-cement-stratum system is crucial for evaluating wellbore integrity. Previous models treated in-situ stress as boundary pressure loads, leading to unrealistic infinite displacements at infinity. This study presents a three-dimensional (3D) analytical solution for the stress field within the casing-cement-stratum system in inclined wells, considering in-situ stress and hydrostatic stress in cement as the initial stress state and taking into account stress components related to the axial direction. Assuming a plane strain condition and superimposing the in-plane plane strain problem, elastic uni-axial stress problem and anti-plane shear problem, a 3D analytical solution is obtained. Comparisons with previous models indicate that the existing model overestimates the absolute values of stress components and failure potential of casing and cement in both 2D and 3D scenarios. The presence of initial stress in cement greatly increases the absolut... [more]

A hardware-in-the-loop (HIL) experimental test-bench is suggested for a rotodynamic pump in this paper. The HIL simulator is composed of two separate modules and two variable-speed drive (VSD) systems that are connected with the help of a programmable logical controller (PLC) and a process field bus unit. One of the fundamental components of the suggested simulation approach is the mathematical representation of a rotodynamic pump system embedded into HIL. A number of tests were conducted in order to study the suggested simulation approach. The experiments demonstrated the developed system’s adaptability and precision in replicating the behavior of the rotodynamic pump in various operation modes. A special user interface for the HIL simulation allows for changing the types of preloaded pump characteristics, reading the output data, and controlling operational parameters. The obtained simulation results showed that the proposed approach can be suitable for research purposes.

Today, fog and cloud computing environments can be used to further develop the Internet of Things (IoT). In such environments, task scheduling is very efficient for executing user requests, and the optimal scheduling of IoT task requests increases the productivity of the IoT-fog-cloud system. In this paper, a hybrid meta-heuristic (MH) algorithm is developed to schedule the IoT requests in IoT-fog-cloud networks using the Aquila Optimizer (AO) and African Vultures Optimization Algorithm (AVOA) called AO_AVOA. In AO_AVOA, the exploration phase of AVOA is improved by using AO operators to obtain the best solution during the process of finding the optimal scheduling solution. A comparison between AO_AVOA and methods of AVOA, AO, Firefly Algorithm (FA), particle swarm optimization (PSO), and Harris Hawks Optimization (HHO) according to performance metrics such as makespan and throughput shows the high ability of AO_AVOA to solve the scheduling problem in IoT-fog-cloud networks.

Soaking is an important step in making tempeh. Tempeh fermentation normally involves the natural presence of proteolytic bacteria capable of producing protease enzymes to break down peptide bonds in protein molecules. This study evaluated the protein and amino acid content of Jack bean tempeh (Canavalia ensiformis) soaked in distilled water during natural fermentation for 12, 24, 36, and 48 h. In this study, the crude proteins were determined using the Kjeldahl technique, amino acids were determined from protein hydrolysis, and proteolytic bacteria were enumerated for Total Plate Counts and further identified using Vitek 2.0 Compact System. The results showed that soaked Jack beans have higher protein and amino acid content, with sixteen essential and non-essential amino acids required for human bodies. The protein content of soaked Jack beans varied from 35% at 12 h to 32% at 24 and 36 h and 33% at 48 h. Soaking for 12 h yielded the highest amino acid concentration of 38,000 mg/kg L-g... [more]