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]

Time, cost, and quality are critical factors that impact the production of intelligent manufacturing enterprises. Achieving optimal values of production parameters is a complex problem known as an NP-hard problem, involving balancing various constraints. To address this issue, a workflow multi-objective optimization algorithm, based on the dynamic virtual staged pruning (DVSP) strategy, was proposed to optimize multi-stage nonlinear production processes. The algorithm establishes a virtual workflow model based on the actual production process and proposes a pruning strategy to eliminate the indirect constraint relationship between tasks. A virtual hierarchical strategy is employed to divide the task node set, and the Pareto optimal service set is calculated through backward iteration in stages. The optimal path is generated through forward scheduling, and the global optimal solution is obtained. The algorithm was compared with the minimum critical path algorithm (MCP) and the partial c... [more]

Differences in the synthesis methods can affect the performance of nanocomposite materials. The synthesis methods of SiO2-based nanocomposite pour point depressants synthesized by chemical hybrid are mostly in situ polymerization and chemical grafting. However, there are still some gaps in the synthesis of nanocomposites using chemical grafting. In this paper, the amino-modified Nano-SiO2 and octamethyl methacrylate-maleic anhydride copolymer was used to prepare PM18-g-NSiO2 by an amidation reaction, and the product was compared with PM18/SiO2 prepared by the solution blending method. The characterization results of FT-IR and SEM showed that the chemical bond formed between PM18 and NSiO2 and PM18-g-NSiO2 showed a more regular morphology structure. The results of rheological tests showed that the optimal concentration of PM18-g-NSiO2 and PM18/SiO2 is 300 mg·kg−1, but the decrease of PM18-g-NSiO2 is 19 °C, while the decrease of PM18/SiO2 is only 13 °C. The lowest viscosity of model oil... [more]

Due to their low concentration and complex nature, the low-cost online and real-time monitoring of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) is a challenge. In this paper, based on a coupling adsorption model of activated carbon and the relationship of PCDD/Fs and flue gas, an online monitoring system with real-time control of final PCDD/F emissions was built for the tracing and control of PCDD/F emissions in municipal solid waste incinerators (MSWIs). According to the online monitoring system, the effects of activated carbon concentration, the specific surface area of activated carbon (AC), operating temperature, contact time, fly ash concentration, residence carbon concentration of fly ash, and the lime concentration of final PCDD/F emissions were discussed. These MSWI operating parameters for reaching standards of 0.1 ng international toxic equivalents (TEQ)/Nm3 and 0.05 ng TEQ/Nm3 were summarized by the predicting model based on several published... [more]

Conventional wastewater treatment plants (CWTPs) are intensive energy consumers. New technologies are emerging for wastewater treatment such as microbial electrolysis cells (MECs) that can simultaneously treat wastewater and generate hydrogen as a renewable energy source. Mathematical modeling of single and dual-chamber microbial electrolysis cells (SMEC and DMEC) has been developed based on microbial population growth in this study. The model outputs were validated successfully with previous works, and are then used for comparisons between the SMEC and DMEC regarding the hydrogen production rate (HPR). The results reveal that the daily HPR in DMEC is higher than in SMEC, with about 0.86 l H2 and 0.52 l H2, respectively, per 1 L of wastewater. Moreover, the results have been used to compare the HPR in water electrolysis (WE) processes and MECs. WE consume 51 kWh to generate 1 kg of hydrogen, while SMEC and DMEC require only 30 kWh and 24.5 kWh, respectively.

We are witnessing the growth of microgrid technology and the development of electric vehicles (EVs) in the world. These microgrids seek demand response (DR) and energy storage for better management of their resources. In this research, microgrids, including wind turbines, photovoltaics, battery charging/discharging, and compressed air energy storage (CAES), are considered. We will consider two scenarios under uncertainty: (a) planning a microgrid and DR without considering CAES, and (b) planning a microgrid and DR considering CAES. The cost of charging the battery in the second study decreased by $0.66 compared to the first study. The battery is charged with a difference of $0.7 compared to the case of the first study. We will also pay for unsupplied energy and excess energy in this microgrid. Then, we test the scheduling of vehicles to the grid (V2G) in the IEEE 33-bus network. The first framework for increasing network flexibility is the use of EVs as active loads. The scheduling of... [more]

In many process engineering fields, gas-particle fluidized beds are widely used. In fluidized bed research, the discrete element method, or DEM, has been a powerful tool for design and operation purposes. However, with the use of Type-A powders, fluid catalytic cracking or FCC particles being classical cases, they have hardly been reported in DEM simulations of fast fluidization. This study paid close attention to the suitable selection of a stiffness constant and a DEM time step. To reflect their respective effects and complicated interactions, a so-called relative DEM time step was defined. The drag coefficient was correlated using the energy-minimization multi-scale (EMMS) approach to reasonably calculate the gas−solid interaction. Six representative cases with different relative time step values were chosen to simulate a micro-fluidized bed of Type-A FCC powders. The results showed that DEM employing EMMS-based drag force was able to greatly enlarge the suitable range of relative t... [more]

Fruit and vegetables (FV) are the major source of bioactive compounds for human beings. FV supply chains are complex and sensitive due to various features, including the seasonality of products, variations in demand, and short shelf-lives. The amount of waste in FV supply chains is significant compared with other supply chains as 44% of fresh FV produced globally are wasted in the food chain. This large amount of waste has a significant impact on the economy, food security, available natural resources, and the environment. To reduce food losses in the fresh food supply chain (FFSC), the root causes of waste must be first identified. While a number of researchers have investigated food losses in Australia, most only consider a specific stage in the supply chain and multiple stages in the FFSC are often overlooked. Additionally, the impact of advanced storage technologies, packing, handling, and transport on food losses should be investigated. Furthermore, supply chain practices are chan... [more]

This paper proposes a model for determining deformation in the upper 50% of an ice borehole. Based on this model, the borehole deformation of DK-1 at Dome A was studied. Furthermore, the effects of surface temperature, temperature gradient, surface snow density, and drilling fluid density on borehole deformation were investigated. The results showed that borehole shrinking, expansion, and mixed existence occurred simultaneously in DK-1. Borehole deformation increased with increasing surface temperature, while temperature gradient had a minimal effect. Borehole deformation also increased with increasing surface snow density and decreasing drilling fluid density when the borehole shrank; however, the situation was reversed when the borehole expanded. The influence of ice temperature was dominant in deformation. However, when depth exceeded 1200 m, the sensitivity of ice borehole deformation in the direction of the minimum principal stress increased with an increase in drilling fluid dens... [more]