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The present era sees the dominance of wind energy conversion systems as a leading technology in renewable energy. Various technologies have been devised to harness wind energy, with variable speed systems emerging as particularly advantageous. Consequently, these systems are designed to operate at specified speeds using power electronic interfaces, maximizing power extraction from the wind. The integration of Permanent Magnet Generators (PMGs), directly linked to the wind turbine lacking a gearbox, allows operation at minimum speeds. To stabilize the continuously fluctuating output voltage of the PMG, power electronic converters are extensively utilized in Wind Energy Conversion Systems (WECS), ensuring a consistent voltage and frequency output. The voltage gain of Traditional matrix converters (MCs) is limited to less than 0.866. In turn, the Z-source (ZS) and discontinuous QZSDMC, as well as ZS IMCs, topologies have achieved voltage gains exceeding 0.866. However, the former provides complicated commutation issues from DMC, while the latter incorporates a Z source network in the DC link, resulting in a non-all-silicon solution. A novel continuous QZSDMC and QZSIMC are suggested, wherein a qZS network incorporates the grid-side filtering function. This design eliminates the need for an additional input filter in the proposed system. Three newly introduced topologies of ZSDMC, QZSDMC and QZSIMC are thoroughly compared across various parameters including voltage gain, current and voltage ripples, inductor current and capacitor voltage stresses, filtering capabilities, input current, and output voltage Total Harmonic Distortion (THD), finally efficiency. The paper presents their control and modulation methods to achieve the desired performance levels. Experimental comparisons validate the theoretical analysis and demonstrate the potential of the proposed QZSDMC as a promising topology.

This article proposes a dual space vector PWM control technique for a three-phase to five-phase quasi Z-source direct matrix converter (QZSDMC). The proposed circuit consists of a quasi-impedance source network along with a five-phase traditional matrix converter. With the observation of bidirectional operating capability and the utilization of shoot-through duty ratio, the proposed converter can ensure both buck and boost operations. This converter overcomes the voltage transfer ratio restriction and poor voltage regulation of the traditional matrix converter. Also, this converter ensures continuous input current with an absence of input LC filter components. The proposed direct AC to AC power converter gives an alternate solution to the multiphase drive system instead of the traditional voltage source inverter. The developed dual space vector PWM control technique for three-phase to five-phase voltage conversion is derived from the basic space vector PWM approach. The proposed dual space vector PWM technique utilizes 90 active states and 3 zero vector states among 243 switching states. The QZSDMC has been analysed with a dual space vector PWM approach along with the distribution of shoot-through state in the zero vector. The proposed topology along with the control strategy has been simulated using MATLAB/Simulink environment.

The Gas Tungsten Arc Welding process weld for the 4 mm thickness of the ASTM A36 steel plate with varied heat input parameters of 0.608 kJ/mm, 0.900 kJ/mm and 1.466 kJ/mm, respectively. The effect of different heat inputs on microstructure, corrosion, and mechanical characteristics of developed weld joints are examined by three zones: heat-affected zone, welded zone, and base metal zone. The optical microscopic results of weld joints illustrate that fine grain structure leads to enhance welding strength. It is revealed that the increased heat input parameter on the weld joint shows a decreased tensile strength and hardness of the weld joint. The corrosion resistance of the weld joint is evaluated by Potentio-dynamic polarization. It facilitates that the corrosion rate of the weld joint is decreased with increasing heat input, which results indicate the best and worst corrosion micrograph of the polygonal ferrite and ferrite plus polygonal ferrite. However, the weld joint prepared with 0.900 kJ/mm heat input found maximum corrosion resistance.

Research and developments on preparing electrode material for lithium-ion batteries are burgeoning nowadays widely. In this study, we used the high energy ball-milling method to prepare pure and samarium-doped lithium manganese oxide (Li4Mn5O12) and investigated its structural, morphological, and electrical properties. The XRD spectrum for the produced materials confirmed the phase purity and crystallinity of the material. The fourier transform infrared spectrum was used to determine the different sorts of vibrations between molecules. The particle size with the presence of polyhedral-shaped morphology was certified by using SEM and TEM analysis. EDS mapping was used to assess the elemental composition and purity of the samples. Complex impedance spectroscopy analysis was used to investigate the temperature dependency of the materials’ electrical properties, and high conductivity (1.15 × 10−7 S cm−1) was reported for samarium-doped lithium manganese oxide at 100°C, and its dielectric relaxation behavior was examined.

Abstract Traumatic brain injury (TBI) is associated with poor clinical outcomes; autopsy studies of TBI victims demonstrate significant oligodendrocyte progenitor cell (OPC) death post TBI; an observation, which may explain the lack of meaningful repair of injured axons. Whilst high-mobility group box-1 (HMGB1) and its key receptors TLR2/4 are identified as key initiators of neuroinflammation post-TBI, they have been identified as attractive targets for development of novel therapeutic approaches to improve post-TBI clinical outcomes. In this report we establish unequivocal evidence that HMGB1 released in vitro impairs OPC response to mechanical injury; an effect that is pharmacologically reversible. We show that needle scratch injury hyper-acutely induced microglial HMGB1 nucleus-to-cytoplasm translocation and subsequent release into culture medium. Application of injury-conditioned media resulted in significant decreases in OPC number through anti-proliferative effects. This effect was reversed by co-treatment with the TLR2/4 receptor antagonist BoxA. Furthermore, whilst injury conditioned medium drove OPCs towards an activated reactive morphology, this was also abolished after BoxA co-treatment. We conclude that HMGB1, through TLR2/4 dependant mechanisms, may be detrimental to OPC proliferation following injury in vitro, negatively affecting the potential for restoring a mature oligodendrocyte population, and subsequent axonal remyelination. Further study is required to assess how HMGB1-TLR signalling influences OPC maturation and myelination capacity.

Cathodic electrodeposition (CED) was used to coat the cast magnesium alloy Mg-9Al-1Zn-xRE with aluminum powder and epoxy. Immersion and salt spray tests (ASTM B117) at room temperature for a total of 240 hours have been performed to assess the corrosion performances of AZ91D magnesium alloy. At each 24-hour interval, the samples were checked for any damage or deterioration of the coating surface morphology. The X-ray diffraction (XRD) analysis confirmed the phases, and scanning electron microscopy (SEM) with EDS analysis confirmed the phase composition. The electrochemical results show that CED epoxy coatings have superior adhesiveness and corrosion resistance compared to powder-coated aluminum and cast magnesium. The salt spray and immersion test results also confirm that CED epoxy coating exhibits good corrosion resistance.

Lightweight materials are extremely needed for the manufacturing of industrial parts and are used in aerospace, automobile body shops, biomedical instruments, etc. Aluminium alloy is one of the light-weight materials, and it fulfills the industrial demands based on their natural strength/stiffness, enhanced temperature permanence, superior wear, and corrosion resistance. This experimental work considered aluminium alloy (AA8014) with reinforced particles of silicon nitride (Si3N4) and zirconium dioxide (ZrO2) for preparing aluminium hybrid composites. Hybrid composites are prepared by a stir casting process involving different process parameters. L27 orthogonal array is used for optimizing the stir casting parameters with the assistance of the statistical Taguchi approach. Stir casting parameters are the percentage of reinforcement (4%, 6%, and 8%), stir speed (400 rpm, 500 rpm, and 600 rpm), stir time (20 min, 25 min, and 30 min), and molten temperature (700 oC, 800 oC, and 900 oC). Mechanical performance such as wear and microhardness of the hybrid composites is evaluated. Minimum wear and higher microhardness are encountered at a percentage of reinforcement = 6%, stir speed = 400 rpm, stir time = 30 min, and molten temperature = 900°C. In wear analysis, the percentage of reinforcement highly influences the wear properties (7.06% contribution). In microhardness analysis, molten temperature parameter is the extreme influencer (11.15% contribution).

In this research work, the analysis of mechanical and metallurgical properties of AZ91D + XCe + XLi cast magnesium (Mg) alloys in adding cerium (Ce) and lithium (Li), where X can be varied. The destructive tests viz. mechanical test, tensile strength test, and microhardness test are used to investigate mechanical properties of AZ91D alloy in adding various weight percentages viz. 0.5, 1, 2, of Ce and Li. This result of this present investigation reveals that there will be refinement of grain size on AZ91D alloy in adding Ce and Li. The formation of second phase Al2Ce that has superior melting point, changes the distribution of the phase Mg17Al12 from a continuous network morphological transition to a tiny and dispersive distribution along the grain boundary. Furthermore, adding Li to the AZ91D magnesium alloy lowers the corrosion current density in a 3.5 percent NaCl solution, improving the alloy’s corrosion resistance. The results show that the AZ91D magnesium alloy, which contains 0.5 percent Ce + 1.0wt.%, outperforms other magnesium alloys.

Nanocrystalline powders of 4 mol.% GdO1.5-4 mol.% SmO1.5 doped ZrO2 (4Gd4SmSZ) has been synthesized by co-precipitation process. Their phase transformation and crystalline growth behavior was investigated by Thermo gravimetric-Differential Thermal Analysis (TG-DTA), X-ray Diffraction (XRD), Raman spectroscopy and High-Resolution Transmission Electron Microscopy (HR-TEM) after calcinations at different temperatures. The XRD, Raman spectra and HRTEM results confirm the nature of tetragonal zirconia (t-ZrO2). The prepared 4Gd4SmSZ powders, remains in the single metastable tetragonal phase over the whole calcination temperature ranging from 873 K to 1273 K for 2 h. The crystallite size varies from 11.98 nm to 18.90 nm with increase of temperature from 873 K to 1273 K. The activation energy of the prepared powders at low temperature is considerably lesser than that at a higher temperature. The annealed 4Gd4SmSZ powders had shown excellent phase stability at 1573 K for 100 h. Keywords: Zirconia, Coprecipitation, Rare earth oxide, Phase transformation, Tetragonal, Activation energy

Due to high vapour pressure at ambient conditions, exposed mercury contributes significant vapour concentration in working atmosphere. Ventilation is a conventional, cheap and very effective method to bring down the concentration of hazardous materials like mercury vapour below permissible limit. In this work a numerical model was developed to obtain intuitive understandings of the spatial distribution of mercury vapors from an exposed surface. The model was validated with experimental data generated using a precinct ventilation system with 8.14% absolute average error. a Validated model was used to study the effect of air flow rate (100–1200 LPM) and impact of architectural design of the containment for fixed exposed mercury surfaceon the final (diluted) mercury concentration. Comparative analysis shows that modification in structural design offers a reduced volume averaged exit mercury concentration and also the reduced peak mercury concentration(Cpeak) in the computational domain. Computational approach outlined in this work can be used to estimate spatial variation of mercury vapor concentration and to locate and quantify regions of high local concentration of mercury in various geometries.

The corrosion behaviour of Mg–6Al–1Zn + XCe (where X = 0.5, 1.0, 1.5 and 2.0 wt% Ce) alloys, aged for 18 h at different temperatures of 180 °C, 200 °C, 220 °C and 240 °C, was studied in 3.5 wt% NaCl solution. The salt spray test was conducted in accordance with ASTM-B117 standard (fog test). The corrosion morphologies, corrosion rate and the composition of the corrosion products were investigated by X-ray Diffraction (XRD), Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) techniques. The results show the cerium addition and ageing treatment has significantly influenced the corrosion morphologies and the corrosion rate. In AZ61 alloy, the intermetallic β (Mg17Al12) phase acts as a corrosion barrier and upon ageing the Al4Ce phase precipitates along the α grain boundaries. The precipitation modifies the β phase to form more continuous network which subsequently reduces the corrosion attack in the chlorine environment. Salt spray test result shows the AZ61 alloy with 1.5 wt% Ce aged at 220 °C exhibits the better corrosion resistance.

The corrosion behavior of cast Mg–6Al–1Zn + XCa (Where X = 0.5,1.0,1.5 and 2.0 wt.% Ca) magnesium alloy, aged at different temperatures of 180 °C, 200 °C, 220 °C and 240 °C was investigated in accelerated corrosion test chamber according to ASTM-B117 Standard (salt spray test). The exposed alloys were characterized by X-Ray Diffraction (XRD), Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) techniques. The microstructural refinement due to calcium addition and ageing treatment results in the improvement of corrosion resistance of the experimental alloy. Corrosion rate decreases due to fine precipitation of the β (Mg17Al12) phase distributed along the α-grain boundaries during ageing. Intermetallic phases act as a barrier, which makes the alloy more resistant to corrosion. Results found that better corrosion resistance of the alloy was observed in Mg–6Al–1Zn + 1.5 wt.% Ca with 180 °C ageing temperature. The corrosion behavior of Mg–6Al–1Zn + XCa alloy exhibited by ASTM B117 salt spray testing and electrochemical polarization measurements showed similar trends concluding that the calcium addition and ageing temperature decreases the corrosion rate.

In the crystal of the title hydrated molecular salt, C8H12NO+·Cl−·H2O, the water molecule makes two O—H...Cl hydrogen bonds, generating [010] zigzag chains of alternating water molecules and chloride ions. The cation is bonded to the chain by an O—H...O hydrogen bond and two weak C—H...Cl interactions. Weak aromatic π–π stacking [centroid–centroid separation = 3.5175 (15) Å] occurs between the chains.

The title salt, C8H12NO+·Br−·H2O, is isomorphous with the chloride analogue [Seethalakshmi et al. (2013). Acta Cryst. E69, o835–o836]. In the solid state, the cations, anions and water molecules are interlinked by a network of O—H...O, O—H...Br and C—H...Br interactions. The water molecule makes two O—H...Br hydrogen bonds, generating [010] zigzag chains of alternating water molecules and bromide anions. The cation is involved in two intermolecular C—H...Cl interactions in the chloride salt, whereas three intermolecular C—H...Br interactions are observed in the title bromide salt. This additional intermolecular C—H...Br interaction links the adjacent water and bromide zigzag chains via cationic molecules. In addition, weak π–π stacking interactions are observed between pyridinium rings [centroid–centroid distance = 3.5664 (13) Å].

Background: Os naviculare in general alters the functional and anatomical balances of the longitudinal plantar arch. A substantial number of the posterior tibialistendon fibersinsert on the accessory ossicle instead of its insertion on tarsal and metatarsal bones resulting in unbalanced stress forces on the tendon. The presence of an accessory navicular type II or type III is a risk factorfor PTT tendinopathy and possible PTT tear. Methodology: In this single subject case study, the participant reported with the pre-diagnosed Os naviculare. On examination at initial presentation, the navicular tuberosity of the affected foot was prominent as compared tothe contralateral limb. The site was tender on palpation. Ankle range of motion was within normal ranges except ankle dorsiflexion was slightly compromised. Mild pain on active and resisted was noted. Functional tests like star excursion balance test, single leg standing could not be performed due to pain. Pre and post protocol assessment was graded and measured on Cumberland ankle instability tool. The tenderness was recorded using numeric pain rating scale. Star excursion balance test was performed one on 8 th day and post protocol. MWM was performed at distal tibiofibular joint on 6 days every week for 3 weeks alongside the conventional regime exercises and ultrasound was applied post treatment session. Result: Result of this study suggested that addition of MWM of distal tibiofibular joint in theconservative exercise protocol was effective in the reduction of pain, dysfunction and improveddynamic control. Conclusion: The results of this study suggests that the addition of MWM of distal tibiofibular joint alongside conservative management shows appreciable effect in improving dysfunction, dynamic stability and reducing pain in individual with congenital Os naviculare. [ABSTRACT FROM AUTHOR]