Around 20% of the population is disabled. Many people have mobility problems, including the elderly and people with young children. It is crucial to adapt cities to the needs of these people and, at the same time, to the needs of all residents. This is the subject of universal design, which should consider inhabitants’ needs and habits. This information can be collected by Internet of Things (IoT) devices that observe and listen to residents. Residents do not accept constant surveillance, so the public may not accept data collection by IoT sensors. This study aimed to identify and evaluate factors influencing the acceptance of data collection by IoT devices for universal design. For this purpose, an online survey was prepared by the Warsaw University of Technology. The following statistical methods were used to analyze the data: descriptive statistics, exploratory factor analysis, confirmatory factor analysis, reliability analysis and structural equation modeling. This paper identifies... [more]

Due to the high nitrogen and phosphorus concentrations in wastewater from soilless cultivation of tomatoes, the sludge formed during wastewater treatment can be used as a source of nutrients in agriculture. The effect of electrical direct current (DC) density (J) and hydraulic retention time (HRT) in a rotating electrobiological contactor (REBDC) on the quantity and quality of sludge generated in the process of tomato soilless cultivation wastewater treatment was determined. The cathode consisted of discs immobilized with biomass, while the anode was an aluminum electrode. HRTs of 4 h, 8 h, 12 h, 24 h and (J) of 0.63, 1.25, 2.50, 5.00, and 10.00 A/m2 were applied. The study showed that the increase in (J) caused an increase in the amount of sludge generated. The increase of (J) contributed to increased concentrations of biogenes in the sludge, whereas extension of HRT at a given current density contributed to increased concentrations of nitrogen and phosphorus (up to 6.2% and 0.8% resp... [more]

Proton exchange membrane fuel cell (PEMFC) powered propulsion has gained increasing attention in urban air mobility applications in recent years. Due to its high power density, ultra-thin heat pipe technology has great potential for cooling PEMFCs, but optimizing the limited internal cavity of the heat pipe remains a significant challenge. In this study, a three-dimensional multiphase model of the heat pipe cooled PEMFC is built to evaluate the impact of three internal structures, layered, spaced, and composite, of ultra-thin heat pipes on system performance. The results show that the heat pipe cooling with the composite structure yields a lower thermal resistance and a larger operating range for the PEMFC system compared to other internal structures because of more rational layout of the internal cavity. In addition, the relationship between land to channel width ratio (LCWR) and local transport property is analyzed and discussed based on composite structural heat pipes. The heat pipe... [more]

The transportation sector has the highest energy demand worldwide and bears the primary responsibility for CO2 emissions. Electromobility has emerged as the most feasible way to alleviate this problem. However, its potential depends heavily on the development of renewable energies. Island regions raise additional barriers to electromobility due to their heavy dependence on fossil fuels. This article addresses this challenge by presenting a comprehensive well-to-wheel framework to assess the levels of efficiency and CO2 emissions of electromobility options such as battery and plug-in electric vehicles (BEVs and PHEVs). The results were compared with those for internal combustion engine vehicles (ICEVs). The framework proposed takes account of various factors including the extraction, refining, and transport of oil, different segments of land vehicles, and electricity system operations. The framework is demonstrated with a case study of the Spanish Canary archipelago. The results show th... [more]

A derivation of the dynamic model of a medium voltage vacuum circuit breaker and induction motor in space vectors in coordinates αβ0 allow us to model switching transients in various dynamic states of the motor. In the case of the Clark transformation, the corresponding numerical integration technique can be selected including variable time-step integration techniques to avoid numerical instabilities due to the stiffness of the system. Assymetrical operations such as switching cause the power system to become unbalanced and the transformed equations α, β, and 0 are not uncoupled. Therefore, it is necessary to derive a coupling matrix between circuit breaker voltages and currents in the coordinate system αβ0. The subject of our interest is switching overvoltages that arise when turning off small inductive currents by a vacuum circuit breaker. When deriving the model of a vacuum circuit breaker, all its properties encountered during this action are taken into account, i.e., current chop,... [more]

This paper proposes an extreme learning machine (ELM)-based adaptive sliding mode control strategy for the receiver-side buck converter system in the wireless power transfer system subjecting to the lumped uncertainty. The proposed control strategy utilizes a singularity-free fixed-time sliding mode (FTSM) feedback control, which ensures a fixed-time convergence for both the sliding variable and voltage tracking error. An ELM-based uncertainty bound estimator is further designed to learn the uncertainty bound information in real-time, which opportunely loosens the constraint of bound information requirement for sliding mode control design. The global stability of the closed-loop system is rigidly analyzed, and the good performance of the proposed control strategy is validated by comparison experiments which exhibit ideal overshoot elimination, 45.70−51.72% reduction of settling time, and 13.65−36.96% reduction of the root mean square value for voltage tracking error with respect to dif... [more]

The microgrid (MG) system is a controlled and supervised power system consisting of renewable energy (RE)-based distributed generation (DG) units, loads, and energy storage. The MG can be operated autonomously or while connected to the grid. Higher intermittencies and uncertainties can be observed in MGs compared to the conventional power system, which is the possible source of small-signal stability in MG systems. It can be seen as disturbances around the stable operating point, which potentially lead to the small-signal instability problem within MGs. Small-signal instability issues also emerge due to the lack of damping torque in the MG. The integration of power electronic devices and complex control algorithms within MGs introduces novel challenges in terms of small-signal stability and possible resonances. The occurrence of interaction in a low- or no-inertia system might worsen the stability margin, leading to undamped oscillatory instability. The interaction within the MG is cha... [more]

Esterification of rosin with pentaerythritol produces rosin pentaerythritol ester (RPE) which is widely used in paint, coating, and pressure-sensitive and hot-melt adhesive industries. Although RPE has excellent valuable applications and has been industrially produced, studies on the reaction kinetics have not been widely reported in the present literature. This work proposed a kinetic study of RPE synthesis by including a series of consecutive reactions forming mono-, di-, tri-, and tetra-ester with decarboxylation of rosin as a side reaction in the kinetics model. For esterification, the reaction rates were determined by the second-order kinetic model. The first-order kinetic order was proposed for decarboxylation. Kinetic experiments were performed at a temperature range of 260 °C to 290 °C. The initial molar ratio of pentaerythritol to rosin (in the mole of OH/COOH) used was between 0.8 and 1.2. A small amount of samples were withdrawn in certain time interval. The sample was analy... [more]

Films and rivulets are the two basic forms of dynamic liquid in a three-phase fixed bed (trickle bed), which determines the wetting efficiency of the catalyst. This paper is devoted to the conflicting wetting performance observed between non-porous glass beads and less wettable porous alumina, and a parallel zone model is applied to resolve the complex liquid flow texture. It shows in both cases of glass beads and aluminium pellets, the pressure drop, film flow and rivulet flow fractions all display pronounced multiplicities along with the liquid flow rates in increasing and decreasing branches, although the rivulet flow fraction is reduced to 0 in the liquid decreasing branch started from pulsing flow in both cases. Different from the glass beads, there is almost no wetting efficiency difference for the alumina pellets with respect to liquid flow rate increasing or decreasing, which is in agreement with the dynamic liquid holdup measurements. The liquid is significantly more uniformly... [more]

LNT is the major biologically active substance extracted from Lentinus edodes (L. edodes). Although functional and pharmacological studies have demonstrated that LNT has multiple benefits for animals and humans, the safety assessment is far from sufficient. To evaluate the potential safety risk, larval zebrafish were continuously exposed to varying concentrations of LNT for 120 h. The 96 h LC50 of LNT was determined to be 1228 μg/mL, and morphological defects including short body length, reduced eye and swim bladder sizes and yolk sac edema were observed. In addition, LNT exposure significantly reduced the blood flow velocity and locomotor activity of larval zebrafish. The biochemical parameters were also affected, showing reduced glucose, triglyceride and cholesterol levels in zebrafish larvae after being exposed to LNT. Correspondingly, the genes involved in glucose and lipid metabolism were disrupted. In conclusion, the present study demonstrates the adverse potential of high concen... [more]

One of the technical limitations of refuse-derived fuel (RDF) pyrolysis is the high content of tar in its gas products. In order to resolve this problem, a two-stage RDF pyrolysis with a catalyst based on char from RDF pyrolysis is proposed. This paper presents the results of municipal waste pyrolysis beginning in an oven heated to 480 °C and ending with catalytic tar cracking carried out in the temperature range from 800 to 1000 °C. Thermal and catalytic pyrolysis with a char catalyst containing a minimum of 6% Fe resulted in increases in the CO and H2 contents in gas products and decreases in CO2 and CH4. At 1000 °C, the mass ratio of gaseous products to liquids was greater than 6. The residence time of the gases in the catalytic zone was about 3−5 s. The reactor was a good source of hydrogen and carbon monoxide.

Living a healthy lifestyle is the most important need in the world today. However, oxidative stress (OS) is caused by several stress-inducing factors such as smoking, alcohol consumption, chronic diseases, and inflammatory responses, oxygen-free radicals are produced in excess and can damage major organs in the body. This phenomenon has been implicated in the pathogenesis of several gastrointestinal (GI) diseases, including gastritis, constipation, and inflammatory bowel diseases, which include Crohn’s disease, ulcerative colitis, functional dyspepsia, acid reflux, diverticular disease, and irritable bowel syndrome. In this review article, we provide a brief overview of the role of OS in the pathogenesis of GI disorders. Additionally, we discuss the therapeutic role of alkaline-reduced water (ARW) on GI diseases and existing studies on ARW related to GI diseases. Furthermore, we believe that findings from this review article will enhance the knowledge of the readers on the role of ARW... [more]

In this paper, a two-dimensional, two-layer quality regression model is established to monitor multi-phase, multi-mode batch processes. Firstly, aiming at the multi-phase problem and the multi-mode problem simultaneously, the relations among modes and phases are captured through the analysis between process variables and quality variables by establishing a two-dimensional, two-layer regression partial least squares (PLS) model. The two-dimensional regression traces the intra-batch and inter-batch characteristics, while the two-layer structure establishes the relationship between the target process and historical modes and phases. Consequently, online monitoring is carried out for multi-phase, multi-mode batch processes based on quality prediction. In addition, the online quality prediction and monitoring results based on the proposed method and those based on the traditional phase mean PLS method are compared to prove the effectiveness of the proposed method.

Exploring the potential usage of the acellular preparation of porcine hemoglobin (PHb) isolated from slaughterhouse blood as a cell culture media component, we have tested its effects on the functional characteristics of stromal cells of mesodermal origin. Human peripheral blood mesenchymal stromal cells (PB-MSCs) were used in this study as a primary cell model system, along with three mouse cell lines (ATDC5, MC3T3-E1, and 3T3-L1), which represent more uniform model systems. We investigated the effect of PHb at concentrations of 0.1, 1, and 10 μM on these cells’ proliferation, cycle, and clonogenic and migratory potential, and found that PHb’s effect depended on both the cell type and its concentration. At the lowest concentration used (0.1 μM), PHb showed the least evident impact on the cell growth and migration; hence, we analyzed its effect on mesenchymal cell multilineage differentiation capacity at this concentration. Even under conditions that induce a specific type of MSC diffe... [more]

Kinetics of hydrothermal degradation of colorless polyethylene terephthalate (PET) waste was studied at two temperatures (300 °C and 350 °C) and reaction times from 1 to 240 min. PET waste was decomposed in subcritical water (SubCW) by hydrolysis to terephthalic acid (TPA) and ethylene glycol (EG) as the main products. This was followed by further degradation of TPA to benzoic acid by decarboxylation and degradation of EG to acetaldehyde by a dehydration reaction. Furthermore, by-products such as isophthalic acid (IPA) and 1,4-dioxane were also detected in the reaction mixture. Taking into account these most represented products, a simplified kinetic model describing the degradation of PET has been developed, considering irreversible consecutive reactions that take place as parallel in reaction mixture. The reaction rate constants (k1−k6) for the individual reactions were calculated and it was observed that all reactions follow first-order kinetics.

Oxide impurities such as boria (B2O3) and zirconia (ZrO2) on the surfaces of zirconium diboride (ZrB2) particles are known to limit their sinterability. Among the impurities, B2O3 on the surface of ZrB2 particles could be easily removed by methanol or hydrofluoric acid. However, the remaining ZrO2 still gave negative influences on the sinterability. In this study, ZrB2 particles were treated with various acids to remove oxide impurities on their surfaces. The acid treatments were found to vary in efficacy, according to acid type, and affect the crystallinity and morphology of ZrB2 particles to varying degrees, in some cases forming additional impurities. In particular, the change in the oxygen content of the ZrB2 particles induced by acid treatment was found to depend on the type of acid. The results of the acid treatments were compared which revealed that HNO3 treatment optimizes the purity of ZrB2 particles. In addition, the effects of acid treatment on the surface properties of ZrB2... [more]

In order to evaluate the effect of inert powder on the ignition sensitivity of sucrose dust, this study investigated the effects of NaHCO3, NaCl, NH4H2PO4 and Al(OH)3 on the minimum ignition energy (MIE) of sucrose dust. The results showed that all four different inert powders inhibited the MIE of sucrose dust, and all of them showed a trend that the smaller the particle size of the inert powders, the better the inhibition effect. The inhibition effect was ranked as NaHCO3 > NH4H2PO4 > NaCl > Al(OH)3. NaHCO3 and NH4H2PO4 had both physical and chemical inhibition effects, which were better compared to NaCl and Al(OH)3, which had only physical inhibition effects. Analysis of the flame images showed that the inert powder slowed down the combustion of the sucrose dust flame and reduced the flame height. No flame appeared in the region of higher inert powder concentration.

Shale reservoirs are the hot issue in unconventional resources. The key to the development of shale reservoirs lies in the complex fractures, which are the only path for fluid to migrate from the matrix to the wellbore in shale reservoirs. Therefore, the characteristics of shale fracture surface morphology directly affect fluid migration in shale reservoirs. However, there are few reports about the characteristics of shale fracture surface morphology as the parallel plate model was commonly used to characterize the fracture, neglecting its surface morphology characteristics and leading to great deviation. Thus, description methods were introduced to characterize shale fracture surface morphology with the aim to provide a foundation for the development of shale resources. Three shale samples were fractured by the Brazilian test, and the height distribution of the fracture surface was captured by a three-dimensional profilometer. Then, three-dimensional fracture surface morphology was re... [more]

This research proposed a novel global maximum power point tracking (global-MPPT) algorithm. The proposed algorithm eliminates the perturbation and observation (P&O) technique disturbance problem that the power point will be stuck at the local peak power point under a partial shading condition (PSC). The proposed global-MPPT algorithm detects the photovoltaic module (PV-M) environment irradiance level by the relationship between the output power and voltage of the PV-M. In the proposed algorithm, the important parameter w is determined by the PV-M output power and irradiance level, which is also the compensation parameter that corresponds to the relationship of temperature. The proposed global-MPPT algorithm is aimed to predict the best duty cycle of the global-MPPT based on the irradiance level, parameter w, PV-M output voltage, and load, and then achieve the maximum power point (MPP) quickly and accurately. The measurement results under UIC and PSC verify that the proposed global-MPPT... [more]

In the current study, eleven sooty mold isolates were collected from different tropical host plants. The isolates were identified under Capnodium, Leptoxyphium and Trichomerium, based on morphology and phylogeny. For the secondary metabolite analysis, the isolates were grown on Potato Dextrose Broth (PDB). The well-grown mycelia were filtered and extracted over methanol (MeOH). The metabolites in the growth medium (or filtrate) were extracted over ethyl acetate (EtOAc). The antifungal activities of each crude extract were tested over Alternaria sp., Colletotrichum sp., Curvularia sp., Fusarium sp. and Pestalotiopsis sp. The metabolites were further tested for their total phenolic, flavonoid and protein content prior to their antioxidant and anti-fungal potential evaluation. The MeOH extracts of sooty molds were enriched with proteins and specifically inhibited Curvularia sp. The total phenolic content and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) activity was largel... [more]

When the axial-flow pump is running, the blade angle is not fully adjusted or there are errors in the manufacture of the blades, which will lead to inconsistent blade placement angles during operation, and which will reduce the efficiency of the axial-flow pump. This paper uses the research methods of numerical simulation and model experiments to analyze the hydraulic performance and impeller structure characteristics of each flow components under different schemes when the angles of each blade of the S-type front shaft extension tubular pump device are inconsistent. The research phenomenon is that the guide vane greatly recovers the flow velocity circulation at the impeller outlet, reduces the hydraulic loss of guide vane, and widens the best efficiency range with an increase in guide vane blade angle. When the blade angle deviation occurs, the flow field of each blade channel affects each other, and the maximum decrease in the best efficiency is up to 7.78%, mainly due to the increas... [more]

The COVID-19 pandemic has influenced the epidemiology of other respiratory pathogens, and this was most evident in the 2020−2021 season, which was characterized by a low circulation of influenza viruses. We aim to present a comparative analysis of clinical and epidemiological characteristics of 2018−2019 influenza cases and 2020−2021 COVID-19 cases, hospitalized at a tertiary infectious diseases hospital in Bucharest. We used data collected from patients admitted for severe acute respiratory infection (SARI) and subsequently confirmed with either influenza or COVID-19. During the 2018−2019 season, 208 patients over 18 years of age were confirmed with influenza (median age = 53 years, 59.6% were female) and 6.7% had been vaccinated against influenza. The most frequent symptoms were fever (97.1%) and cough (94.7%), and 77.4% had at least one chronic condition. 90.4% received influenza antiviral therapy. During the 2020−2021 season, 191 patients were confirmed with COVID-19 (median age =... [more]

This study aimed to compare the performance and economic efficiency of greenhouse solar and hot air drying. These are widely used and inexpensive techniques for preserved fruit production in Thailand. Two drying methods were used to dry mango fruit, var. Nam Dok Mai. During the process of both drying methods, the moisture content of mango slices was reduced from an average 85.6% to 12.5% wet basis. To determine the most profitable dryer system for investment, economic analyses of greenhouse solar and hot air drying, involving the main variables affecting their profitability, were investigated, including production and maintenance cost, capital costs, revenue, and drying capacities. The internal rate of return (IRR), net present value (NPV), benefit to cost ratio (BCR) and payback period (PBP) were all evaluated. The results of economic evaluation revealed that high values of IRR, NPV, and BCR, and low value of PBP made the two drying systems cost efficient. However, when the incrementa... [more]

Modeling phase change materials (PCMs) has been a topic of research interest in the past, carried out experimentally and by means of computational fluid dynamics (CFD). The implemented solidification and melting (SM) model in Ansys Fluent-based on the enthalpy-porosity formulation is widely used in the literature. To the authors’ knowledge, few publications apply the apparent heat capacity (AHC) method in Ansys Fluent and even fewer have discussed both. The SM approach applies a linear relationship of the liquid fraction between solidus and liquidus temperature although it is known that the phase transition follows a non-linear behavior, which can be captured using the AHC method as a curve shape and location of the specific heat capacity containing information about the nature of phase transition behavior. Important factors in modeling are the temperature dependent thermophysical material properties density, viscosity, and thermal conductivity. They are often considered constant in th... [more]

This work is concerned with the incorporation of semi-mechanistic residence time metrics into population balance equations for twin screw granulation processes to predict key properties. From the historical residence time and particle size data sourced, process parameters and equipment configuration information were fed into the system of equations where the input flow rates and model compartmentalization varied upon the parameters. Semi-mechanistic relations for the residence time metrics were employed to predict the particle velocities and dispersion coefficients in the axial flow direction of the twin screw granulation. The developed model was then calibrated for several experimental run points in each data-set. The predictions were evaluated quantitatively through the parity plots. The root mean square error (RMSE) was used as a metric to compare the degree of goodness of fit for different data-sets using the developed semi-mechanistic relations. In summary, this paper presents a m... [more]