The accurate measurement and modeling of ferromagnetic material losses are vital issues during the design and analysis of electrical machines. Higher loss values can describe the manufactured rotor and stator machine plates better than the catalog data obtained by standardized measurements using the Epstein frame. In this paper, different temperature-dependent models based on the loss-separation principle are introduced and compared with the measurements. The model parameters are computed from customized laboratory and standardized measurements. The customized measurements based on the stator part of an induction machine in the range of the automotive industry standard, i.e., in [−40 °C, ⋯, 180 °C]. The proposed model and measurement process can be used in the post-processing stage of numerical field analysis to obtain electromagnetic losses according to the agreement between measured and simulated results. During a numerically expensive optimization process, this model can be used to... [more]

Ferromagnetic materials are widely used in the manufacturing of key parts of energy equipment, due to their good mechanical properties, such as in nuclear power and pipes. Mechanical stress exists inside of these key parts during operation. Stress can be estimated indirectly by nondestructive testing methods that measure the magnetic flux leakage signals on the surface of the structure, which is of great importance for ensuring the safety of the equipment. However, the physical mechanism of the stress and magnetic field in the magnetization of ferromagnetic materials is still unclear, leading to limited applications of the technique in practice. In this paper, magnetization tests were carried out to investigate magnetization changes under the coupling effect of stress and a noncoaxial magnetic field. Two identical Q195 low-carbon steel specimens were tested. Specimen 1 was subjected to magnetic field values successively increasing from 0 A/m to 6000 A/m under constant uniaxial tension... [more]

Waste straw contains a large amount of lignin, and its resource utilization is not only in line with the national double carbon development strategy, but also to alleviate environmental pollution. Hydrothermal carbonization is a new thermochemical conversion technology, which has attracted much attention because it can directly transform carbon containing waste raw materials with high moisture content and low energy density. To investigate the physicochemical properties and aromatization changes of lignin hydrochar, hydrothermal carbonization experiments were carried out at 290 °C and a solid−liquid ratio of 1:20 for 0.00, 0.25, 0.50, 1.00, 1.50, 2.00, 4.00, 8.00 h, respectively. The experimental results shows that hydrothermal carbonization can increase the combustion quality of lignin. Physical and chemical properties analysis shows that with the increase of hydrothermal carbonization time from 0 to 2 h, the hydrochar content increased from 21.21% to 26.02% and the HHV of hydrochar i... [more]

Phase change materials (PCMs) proved to be valuable and drew the attention of numerous scientists striving to establish novel techniques to minimize energy consumption and expand heat storage; yet a number of challenges hampered their research. This paper provides an overall overview on how to overcome those constraints by adapting nano-enhanced phase change materials, the motivation behind their investigation, their advantages, area of applications, and their impact on thermal management and storage equipment. Recent computational and experimental studies have revealed that nanoparticles are extremely useful in terms of improving the thermo-physical properties of PCMs, allowing nano-PCMs, mainly nano-paraffin, to have a major positive influence on thermal concepts at the economical, ecological, and effectiveness levels. In this context, nano-enhanced PCMs are now able to store and release large amounts of heat in short intervals of time, which is relevant to thermal storage systems an... [more]

Utilizing phase change materials (PCMs) is one of the most effective methods of storing thermal energy and is gaining popularity in renewable energy systems. In order to analyze PCM performance, various numerical methods have been deployed to study the transient behaviour during phase changes. PCMs’ low thermal conductivity prevents their use as pure PCMs in industrial applications. There are various efficient methods of enhancing PCM thermal conductivity, which are addressed in this article. On the other hand, the lattice Boltzmann method (LBM) is very inclusive in the numerical simulation of complex fluid flows, thermal transport, and chemical interactions because of its ability to simply represent various complex physical phenomena, suitability for parallel programming, and easy coding and implementation. Many numerical studies have been conducted on PCMs using the LBM. This study aims to review these studies and categorize them in a way so that one may thoroughly understand the LBM... [more]

A high-energy ball-milling method was applied for different milling times (1 h, 3 h, and 10 h) to synthetize nanocrystalline MgH2 powder samples catalyzed by Fe2Ti. Morphology and microstructure of the powders were characterized by scanning electron microscopy and X-ray diffraction. The recorded diffraction profiles were evaluated by the convolutional multiple whole profile fitting algorithm, in order to determine microstructural parameters of the composites, such as average crystallite size and average dislocation density. Differential scanning calorimetry was performed to investigate the dehydrogenation characteristics of the alloys. It was obtained that there exists an optimal milling time (3 h) when desorption occurs at the lowest temperature. X-ray diffraction of partially dehydrided states confirmed a two-step H-release, including the subsequent desorption of γ-MgH2 and α-MgH2. The effect of milling time on the H-sorption performance was investigated in a Sievert-type apparatus.... [more]

The building envelope provides thermal comfort, an excellent visual view, and sunlight for the occupants. It consists of two parts: (i) an opaque (non-transparent) part (e.g., walls and roofs) and (ii) a transparent part (e.g., windows, curtain walls, and skylight devices). Recently, the use of fully-glazed facades, especially in large cities, has increased due to their aesthetical and structural advantages. This has led this study to review the performance of the currently passive smart glazing technologies. Phase Change Materials (PCMs) as latent energy storage material is the focus of this review, as well as other individual and combined techniques, including shading systems, solar cells (photovoltaic), and chromogenic (thermotropic and thermochromic) materials. PCM-integrated glazing systems have been extensively studied and rapidly developed over the past several decades from the standpoint of unique system designs, such as passive, active, and passive/active mixed designs, intell... [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]

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]

The performance of a metal-enhanced fluorescence (MEF) substrate is fundamentally based on the orientation of the metal nanostructures on a solid substrate. In particular, two-dimensional (2D) periodic metallic nanostructures exhibit a strong confinement of the electric field between adjacent nanopatterns due to localized surface plasmon resonance (LSPR), leading to stronger fluorescence intensity enhancement. The use of vertical vibration-assisted convective deposition, a novel, simple, and highly cost-effective technique for preparing the 2D periodic nanostructure of colloidal particles with high uniformity, was therefore proposed in this work. The influences of vertical vibration amplitude and frequency on the structure of thin colloidal film, especially its uniformity, monolayer, and hexagonal close-packed (HCP) arrangement, were also investigated. It was found that the vibration amplitude affected film uniformity, whereas the vibration frequency promoted the colloidal particles to... [more]

Innovations in food extrusion technology are enabling its rapid expansion and applicability in diverse areas related to bioprocessing and value addition. This study relates raw material particulate rheology to the granular flow in a single screw food extruder. Raw materials based on corn (i.e., meal, flour, and starch), wheat (i.e., farina, flour, and starch), and sucrose (i.e., granulated, superfine, and powdered) were used as model particulate systems for the study. Various particulate-scale characteristics and flow parameters of these nine materials were determined using a powder rheometer, a promising new offline tool. Properties such as basic flow energy, specific energy, cohesion, stability index, flow function, and effective angle of internal friction were good indicators of flowability in an extruder. Corn meal exhibited lower energy requirements and a higher propensity for flow than corn flour (6.7 mJ/g versus 10.7 mJ/g, and “free-flowing” versus “cohesive,” according to Flow... [more]

This work presents an overview of the modern approaches embracing advanced equipment and validation parameters of both liquid and gas chromatography techniques, including thin-layer chromatography (TLC), column liquid chromatography (CLC), and gas chromatography (GC), suitable for the identification and quantitative determination of various bioactive compounds occurring in pharmaceutical products and medicinal plants in the time from 2020 to 2021 (November). This review confirmed that HPLC is an incredibly universal tool, especially when combined with different detectors, such as UV-Visible spectroscopy, mass spectrometry (MS), and fluorescence detection for numerous active ingredients in different pharmaceutical formulations without interferences from other excipients. TLC, in combination with densitometry, is a very efficient tool for the determination of biologically active substances present in pharmaceutical preparations. In addition, TLC coupled to densitometry and mass spectrome... [more]

This review presents the results of the local formation of nanostructured porous silicon (NPSi) on the surface of silicon wafers by anodic etching using a durite intermediate ring. The morphological and crystallographic features of NPSi structures formed on n- and p-type silicon with low and relatively high resistivity have also been investigated. The proposed scheme allows one to experiment with biological objects (for example, stem cells, neurons, and other objects) in a locally formed porous structure located in close proximity to the electronic periphery of sensor devices on a silicon wafer.

Chikungunya virus (CHIKV) is a rapidly emerging mosquito-borne virus that causes a severe febrile illness with long-lasting arthralgia in humans. As there is no vaccine to protect humans and limit CHIKV epidemics, the virus continues to be a global public health concern. The CHIKV envelope glycoproteins E1 and E2 are important immunogens; therefore, the aim of this study is to produce trimeric CHIKV spikes in insect cells using the baculovirus expression system. The CHIKV E1 and E2 ectodomains were covalently coupled by a flexible linker that replaces the 6K transmembrane protein. The C-terminal E1 transmembrane was replaced by a Strep-tag II for the purification of secreted spikes from the culture fluid. After production in Sf9 suspension cells (product yields of 5.8−7.6 mg/L), the CHIKV spikes were purified by Strep-Tactin affinity chromatography, which successfully cleared the co-produced baculoviruses. Bis(sulfosuccinimidyl)suberate cross-linking demonstrated that the spikes are se... [more]

An electrochemical machining (ECM) process for microcavity fabrication with deionized water (DI-water) and an ECM polishing hybrid with alumina powder of 1.0 μm grains on a single micro-EDM machine are proposed. The process adopts tungsten carbide as tool electrode and M-333 tool steel as the mold material. It reveals that employing the 30 μm/min feed rate with 50 mA and 0.2 ms of pulse-width is suitable for DI-water electrochemical machining. The DI-water ECM process can achieve an excellent surface roughness at Ra 0.169 µm on a semispherical round cavity. Combining the ECM with hybrid polishing with the alumina powder can achieve a better profile for a much deeper cavity than pure electrolytic discharge machining. The hybrid ECM polishing can efficiently finish a micro square insert of 0.6 mm length at 64 μm depth. Such ECM milling can achieve an S-shaped microchannel of radius 1.0 mm and a slot of 1.0 × 0.5 mm2 with 110 μm depth, demonstrating its feasibility and the surface integri... [more]

Phosphorus (P) recovery from alternative P-rich residues is essential to meet the growing demands of food production globally. Despite sewage sludge being a potential source for P, its direct application on agricultural land is controversial because of the obvious concerns related to heavy metals and organic pollutants. Further, most of the available P recovery and sludge management technologies are cost-intensive as they require mandatory dewatering of sewage sludge. In this regard, hydrothermal carbonization (HTC) has gained great attention as a promising process to effectively treat the wet sewage sludge without it having to be dewatered, and it simultaneously enables the recovery of P. This study was conducted to analyse and compare the influence of acid (H2SO4) addition during and after HTC of sewage sludge on P leaching and the characteristics of hydrochar. The obtained results suggested that despite using the same amount of H2SO4, P leaching from solid to liquid phase was signif... [more]

Because of increasing environmental awareness, it is becoming more important to remove harmful elements from water solutions. This study used activated carbon (AC) derived from waste wood-based panels as the base material, oxidized with nitric acid (OAC), and grafted with iminodiacetic acid (IDA-OAC) to improve the adsorption capacity and affinity for metals. The characterization of AC, OAC, and IDA-OAC was conducted via FTIR, SEM, N2 adsorption and desorption analysis, elemental analysis, Boehm titration, and point of zero charge (PZC). The instrument studies proved the modified increasing of the functional groups of the adsorbents. Moreover, batch and column experiments were conducted to evaluate the ability of the three adsorbents to remove copper ions from aqueous solution. In batch sorption, IDA-OAC had the highest adsorption capacity (84.51 mg/g) compared to OAC (54.74 mg/g) and AC (24.86 mg/g) at pH 5. The breakthrough point (Ct/Ci = 0.05) of copper ions for IDA-OAC occurred muc... [more]

(1) to demonstrate the anti-inflammatory and anabolic effect of Ozone by determining in serum samples the biochemical levels of IL-6 and IGF-1 in knee osteoarthritis (OA) patients in a real world rehabilitation setting; (2) to differentiate Ozone effect in diabetic (DM)/obese and non-DM/non-obese patients; (3) to evaluate clinical effectiveness by visual analog scale (VAS) and WOMAC scale, and biochemical effect by C-reactive protein (CRP), uric acid and erythrocyte sedimentation rate (ESR). Material and methods: 65 patients with knee OA Kellgren Lawrence (KL) grade 2 or more were analyzed in a retrospective observational study. The study ran from January 2018 to September 2021. Inclusion criteria: (a) patients 18 years or older; (b) with knee OA KL 2° or more; (c) biochemical analysis before-and-after treatment; (d) pain more than 3 on VAS. Exclusion Criteria: (a) previous knee surgery; (b) favism; (c) pregnancy; (d) any other disease that originates lack of collaboration for infiltra... [more]

The elasticity of white blood cells (WBCs) provides valuable insight into the condition of the cells themselves, the presence of some diseases, as well as immune system activity. In this work, we describe a novel process of refined control of WBCs’ elasticity through a combined use of gold nanoparticles (AuNPs) and the microelectrode array device. The capture and controlled deformation of gold nanoparticles enriched white blood cells in vitro are demonstrated and quantified. Gold nanoparticles enhance the effect of electrically induced deformation and make the DEP-related processes more controllable.

In this work, the feasibility of chemoenzymatically transforming biomass-derived D-xylose to furfuryl alcohol was demonstrated in a tandem reaction with SO42−/SnO2-CS chemocatalyst and reductase biocatalyst in the deep eutectic solvent (DES)−water media. The high furfural yield (44.6%) was obtained by catalyzing biomass-derived D-xylose (75.0 g/L) in 20 min at 185 °C with SO42−/SnO2-CS (1.2 wt%) in DES ChCl:EG−water (5:95, v/v). Subsequently, recombinant E.coli CF cells harboring reductases transformed D-xylose-derived furfural (200.0 mM) to furfuryl alcohol in the yield of 35.7% (based on D-xylose) at 35 °C and pH 7.5 using HCOONa as cosubstrate in ChCl:EG−water. This chemoenzymatic cascade catalysis strategy could be employed for the sustainable production of value-added furan-based chemical from renewable bioresource.

In the context of sustainable use of resources, hydrothermal conversion of biomass has received increased consideration. As well, the hydrochar (the solid C-rich phase that occurs after the process) has caused great interest. In this work, spruce bark (Picea abies) wastes were considered as feedstock and the influence of hydrothermal process parameters (temperature, reaction time, and biomass to water ratio) on the conversion degree has been studied. Using the response surface methodology and MiniTab software, the process parameters were set up and showed that temperature was the significant factor influencing the conversion, while residence time and the solid-to-liquid ratio had a low influence. Furthermore, the chemical (proximate and ultimate analysis), structural (Fourier-transform infrared spectroscopy, scanning electron microscopy) and thermal properties (thermogravimetric analysis) of feedstock and hydrochar were analyzed. Hydrochar obtained at 280 °C, 1 h processing time, and 1... [more]

We studied the epoxy polymer surface modification using air plasma treatment in a Gliding Arc (GA) plasma reactor and a pulsed Dielectric Barrier Discharge (DBD). We employed optical emission spectroscopy (OES) measurements to approximate the vibrational and rotational temperatures for both plasma sources, as well as surface temperature measurements with fiber optics and IR thermography to corelate with the corresponding hydrophilization of the epoxy material. Water contact angle measurements revealed a rapid hydrophilization for both plasma sources, with a slightly more pronounced effect for the air DBD treatment. Ageing studies revealed stable hydrophilicity, with water contact angle saturating at values lower than 50°, corresponding to a >50% decrease compared to the untreated epoxy polymer. ATR-FTIR spectroscopy studies showed an additional absorption band assigned to carbonyl group, with its peak intensity being higher for the DBD treated surfaces. The spectra were also correlated... [more]

A very extensive literature review presents the possibilities and needs of using, in endodontics, the alloys commonly known as nitinol. Nitinol, as the most modern group of engineering materials used to develop root canals, is equilibrium nickel and titanium alloys in terms of the elements’ atomic concentration, or very similar. The main audience of this paper is engineers, tool designers and manufacturers, PhD students, and students of materials and manufacturing engineering but this article can also certainly be used by dentists. The paper aims to present a full material science characterization of the structure and properties of nitinol alloys and to discuss all structural phenomena that determine the performance properties of these alloys, including those applied to manufacture the endodontic tools. The paper presents the selection of these alloys’ chemical composition and processing conditions and their importance in the endodontic treatment of teeth. The results of laboratory stu... [more]

Fe-based metallic glass possesses high hardness and brittleness. It is a hard-to-cut metal material and difficult to machine by conventional methods. Although electrical discharge machining (EDM) has advantages in machining hard-to-cut metal materials, recast layer, pores, and micro cracks will form on the machined surface after machining. The study used a helical tool for the micro electrical discharge drilling (µ-EDD) process on Fe-based metallic glass. The influence of processing parameters, including the pulse on time, gap voltage, duty factor, and spindle rotational speed on the micro hole machining quality characteristics was investigated. The helical tool with SiC electrophoretic deposited (EPD) film was used to polish the inner surface of the electrical discharged micro hole. The findings show that the best micro hole accuracy, tool wear length, and inner surface were obtained at the spindle rotation speed of 1150 rpm, pulse on time of 5 μs, gap voltage of 30 V, and duty factor... [more]