Soft Core Research Articles

Power Optimization in Wireless Sensor Network Using VLSI Technique on FPGA Platform

Nowadays, the demand for high-performance wireless sensor networks (WSN) is increasing, and its power requirement has threatened the survival of WSN. The routing methods cannot optimize power consumption. To improve the power consumption, VLSI based power optimization technology is proposed in this article. Different elements in WSN, such as sensor nodes, modulation schemes, and package data transmission, influence energy usage. Following a WSN power study, it was discovered that lowering the energy usage of sensor networks is critical in WSN. In this manuscript, a power optimization model for wireless sensor networks (POM-WSN) is proposed. The proposed system shows how to build and execute a power-saving strategy for WSNs using a customized collaborative unit with parallel processing capabilities on FPGA (Field Programmable Gate Array) and a smart power component. The customizable cooperation unit focuses on applying specialized hardware to customize Operating System speed and transfer it to a soft intel core. This device decreases the OS (Operating System) central processing unit (CPU) overhead associated with installing processor-based IoT (Internet of Things) devices. The smart power unit controls the soft CPU’s clock and physical peripherals, putting them in the right state depending on the hardware requirements of the program (tasks) being executed. Furthermore, by taking the command signal from a collaborative custom unit, it is necessary to adjust the amplitude and current. The efficiency and energy usage of the FPGA-based energy saver approach for sensor nodes are compared to the energy usage of processor-based WSN nodes implementations. Using FPGA programmable architecture, the research seeks to build effective power-saving approaches for WSNs.

Multi-Directional Functionally Graded Sandwich Plates: Buckling and Free Vibration Analysis with Refined Plate Models under Various Boundary Conditions

This study conducts buckling and free vibration analyses of multi-directional functionally graded sandwich plates subjected to various boundary conditions. Two scenarios are considered: a functionally graded (FG) skin with a homogeneous hard core, and an FG skin with a homogeneous soft core. Utilizing refined plate models, which incorporate a parabolic distribution of transverse shear stresses while ensuring zero shear stresses on both the upper and lower surfaces, equations of motion are derived using Hamilton’s principle. Analytical solutions for the buckling and free vibration analyses of multi-directional FG sandwich plates under diverse boundary conditions are developed and presented. The obtained results are validated against the existing literature for both the buckling and free vibration analyses. The composition of metal–ceramic-based FG materials varies longitudinally and transversely, following a power law. Various types of sandwich plates are considered, accounting for plate symmetry and layer thicknesses. This investigation explores the influence of several parameters on buckling and free vibration behaviors.

Effective multiscale structural analysis of thick sandwich structures with 3D woven composite face sheets and a soft core based on coupled micromechanics and refined zigzag theory

In this study, a novel multiscale analysis technique is presented for predicting the mechanical behavior of 3D woven composites. To this end, the model of the representative unit cell (RUC) is generated using SOLIDWORKS computer-aided design package by taking the optical microscopic images as a reference. The fiber volume fractions (FVF) of the impregnated yarns are calculated using the roving parameters and the dry fiber density for each tow separately. Homogenized properties are obtained by utilizing the finite element analysis (FEM) software ABAQUS. The proposed method simplifies the meso-modeling process of 3D woven composites as it does not require CT scanning for geometry generation or sophisticated localized fiber volume fraction measurements. The verification of the current model is carried out both in the meso scale where the RUC surface strains are compared with DIC results and in the macro scale where tensile and flexural tests are simulated and compared with the experiments. Finally, the applicability of this method is demonstrated through an assessment study of the 3D woven composites as facesheets in thick sandwich structures in an isogeometric refined zigzag framework.

Self-assessment questionnaire development for soft skills competency and core value evaluations

Soft skills play a vital role for providing excellent customer service in the healthcare setting. This study aims to develop and assess the instrument validity and reliability before measuring the levels of soft skills competency and core value internalization on staffs at the Sultan Ahmad Shah Medical Centre @International Islamic University Malaysia (SASMEC@IIUM). A self-assessment questionnaire was developed through three phases. The first phase involved reviewing and identifying relevant literatures and existing soft skills assessment instruments through bibliographic searches and expert consultations. A conceptual model was then established based on the selected conceptual frameworks after determining all relevant soft skill domains. The second phase involved generating relevant items, removing duplicate or irrelevant items, and appraising the content validity by three experts. The third phase was data collection, wherein the finalized instrument was distributed to 32 staff of SASMEC@IIUM via google forms. The instrument reliability was investigated through internal consistency reliability or Cronbach’s alpha, with all items, except for the construct ‘gratitude’, achieving acceptable values by exceeding the threshold value of 0.7. Subsequently, two gratitude items were removed from the questionnaire. The current instrument and theoretical framework employed in the self-assessment questionnaire development are valid and reliable for the actual application.

Neutron shielding calculation for DEMO-Prad/SXR measurement system

In plasma fusion devices, the selection of shielding materials is one of the challenges for plasma diagnostic and control systems under high radiation levels during long operation times. This study presents the effect of shielding materials on neutron flux for a radiated power and soft x-ray core intensity measurement system for a DEMOnstration power plant. A calculation model of neutron shielding was used to investigate the neutron shielding performance of borides and carbides for a large distance from plasma to the diagnostic system. The neutron fluxes were characterized for three points close to the measurement system location. The related neutronic calculations were performed with an ADVANTG hybrid code to obtain neutron flux distribution and attenuation rate depending on the thickness of shielding materials. The results indicate that B4C, W2B5, and WB4 are the most effective options to serve as shielding material due to the effect of boron on neutron shielding effectiveness.

Effect of structure of ZnO and SiO2 core-shell composite nanoparticles as lubricant additive on tribological properties of greases

Nano-additives can enhance the tribological properties of greases. In particular, core-shell composite nanoparticles, which combine multiple nanoparticles, have been the subject of recent research due to their superior properties. In this study, based on the friction pairs material, GCr15, by choosing ZnO with low hardness and SiO2 with high hardness, core-shell composite nanoparticles with soft shell hard core SiO2@ZnO and hard shell soft core ZnO@SiO2 were prepared by chemical deposition and calcination methods. The impact of different structural forms of these composite nanoparticles as grease additives were investigated for the first time by adding them into lithium grease. The results show that ZnO@SiO2 have good tribological properties under light load, reducing the COF by 18 % and decreasing the WSD by 22 %. SiO2@ZnO exhibit the best anti-friction effect under heavy load conditions, reducing the COF by 15 % and decreasing the WSD by 28 %. The GCr15-ZnO-SiO2 surface composite film structure is the key to improve the performance of grease in the two composite nanoparticles. It not only has good wear resistance, but also can increase the bearing capacity of the oil film. The two core-shell structure nano-additives provide a new idea for the design of lubricants under special conditions.

Enhanced beam and plate finite elements with shear stress continuity for compressible sandwich structures

This paper concerns and presents new improved beam and plate finite elements for analysing sandwich structures from the structural and modal points of view. In this study, the material behaviour is supposed to be linear elastic and orthotropic, but the method could be extended for nonlinear problems as well. The current models are able to treat the compressibility of the soft core materials, besides the interlaminar continuity conditions and the zero shear stresses on the shear-free surfaces are granted by the Lagrange multiplier method. In order to provide stress continuity along the element boundaries, the Hermite interpolation is employed for the elementary formulations that yields subparametric finite elements. On the contrary, the semi-analytical solutions of these enhanced beam and plate models are also discussed here for particular boundary conditions. The verification of the new finite elements is carried out by two case studies. The test examples are modelled and solved in commercial finite element software (ANSYS) with general shell and solid elements, too. The results derived from different models are subjected to a comprehensive comparison. Also, the structural and modal analyses of the test examples are presented during the case studies. The structural analysis of an overconstrained sandwich panel is also discussed to point out the significance of the proper shear stress distributions. Finally, the advantages and disadvantages of the newly developed elements and semi-analytical solutions are revealed in detail.

Fe-based amorphous powder cores with low core loss and improvement of permeability

Fe-based amorphous powder cores of Fe–Si–B–Cr–C magnetic powder and phenolic binder were fabricated, and the effects of annealing and compaction pressure on the soft magnetic properties and core loss were investigated. The formation of Fe–B and α-Fe (Si) phases was confirmed at the annealing temperature above 773 K. The density gradually increased from 5.3 to 5.5 g/cm3 as annealing temperature increased, resulting in the saturation magnetization 4πMs increased to 1.0 T at 773 K. The effect of compaction pressure was studied by using samples annealed at 723 K. Both the density and 4πMs enhanced with compaction pressure from 980 to 1960 MPa. The real part of permeability µ’ remained constant for the frequency up to 2 MHz. The initial value of µ’ increased from 25 to 38 with compaction pressure. Consequently, at Bm of 50 mT and frequency of 100 kHz, the considerably low core loss of 67 kW/m3 was obtained. The low core loss and moderately high permeability of Fe–Si–B–Cr–C amorphous powder core across a wide frequency range indicate its potential for application in high frequency electronic components.

Evaluation the Quality Three Different Obturation Technique Using Multi-Slice Computed Tomography: An In-Vitro Study

After endodontic space has been completely cleaned, shaped and disinfected, a three-dimensional obturation of this space will be the ultimate objectiv e of endodontic therapy. With a durable three dimensional obturation any communication with the periodontium will be eliminated and prevented. The aim of this study was to use multi-slice CT scanning to determine: (i) number of voids (ii) diameter or length of voids and (iii) presence of voids at material/tissue interfaces in root canals obturated with: (a) E & Q Master (b) Lateral Condensation, and (c) Soft Core system. Thirty freshly extracted human mandibular premolar teeth were used in this study. After pr eparation of the root canals, the teeth were divided into three groups with 10 teeth in each groups. G1 obturated with E&Q master, G2 obturated with Lateral Condensation, and G3 was obturated with Soft Core. GuttaFlow was used as sealer for all groups. After obturation all the specimen were analyzed with multi-slice CT, the data obtained was statistically analyzed us ing ANOVA test followed by Duncan's multiple range test ,a val ue of p< 0.05 was considered statistically significant.Voids are obs erved in all groups, Neither technique was free of voids or p erfectly smooth. Overall, the canals that obturated with E&Q mas ter showed the lowest number of voids (3.0), whereas those ob turated with lateral condensation showed the highest number (3.9) and the differences was statistically significant. The canals t hat obturated with Soft core showed the highest mean of voids diameter ( 0.77 mm) , whereas those obturated with E&Q m aster and lateral condensation had the lowest mean (0.62 mm and 0.61 mm) respectively, and the differences were statisti cally significant. The percentage of outer voids was higher for a ll techniques than the inner voids. The presence of inner voids was the highest in canals that obturated with soft core system (9.230%). Conclusion: E&Q master of obturation show the low est number of voids. Obturation with Soft core show the highest m ean of voids diameter. In all obturation techniques, the outer voi ds was higher than inner voids.

Dynamic response of open doubly curved sandwich shells with soft core subjected to a moving force

Dynamic response of open doubly curved sandwich shells with soft core subjected to a moving force

Improved Anti-Saturation Performance of Fe-Si-Al Soft Magnetic Powder Core via Adjusting the Alloy Composition

Ball-milled Fe-Si-Al soft magnetic powder cores with the particle compositions away from the classical Sendust point were prepared in this work. The influences of alloy composition on the metallographic structure, density, hardness, and resistivity of Fe-Si-Al alloy, as well as the frequency-dependent permeability, loss, and the anti-saturation performance of Fe-Si-Al powder cores, were investigated systematically. It was found that the hardness of Fe-Si-Al alloy increases with the Si mass ratio and the saturation magnetization (Ms) increases with the Fe mass ratio. The alloy hardness affects the particle size after the ball-milling process and, thus, influences the porosity of the powder core. Together with adjusting the demagnetization field by controlling the particle size and the core’s porosity, changing the alloy composition to drive K and λ deviating from zero can effectively improve the anti-saturation performance of Fe-Si-Al powder cores at the expense of hysteresis loss, to some extent. In this work, good comprehensive magnetic properties were obtained in the Fe85.5-Si12-Al2.5 powder core. Its effective permeability percentage at 100 Oe and Ms were 59.12% and 132.23 emu/g, respectively, which are higher than those of the classical Sendust core. This work provides a feasible idea for optimizing the overall performance of the high-power magnetic device.

Evaluation of magnetic inhomogeneities in non-stoichiometric Mg0.5Ca0.5Fe2O4 nanoferrite

Present work reports a systematic study on the evaluation of magnetic inhomogeneities in non-stoichiometric Mg0·5Ca0·5Fe2O4 nanoferrite (MCNF) by conducting exhaustive dc-magnetization, ac-susceptibility and 57Fe Mössbauer spectroscopic measurements and exchange bias investigations using training protocol down to 6 K. Rietveld fitting to PXRD established the formation of anticipated spinel fcc phase of MCNF (non-stoichiometric) along with a minute impurity phase of calcite. Scherrer method and HRTEM micrographs illustrated broad size distribution of MCNF nanoparticles with an average nanocrystallite size of ∼15 nm. Combined 57Fe Mössbauer spectroscopic and dc-magnetization analysis establishes coexistence of ferrimagnetic (67 %) & superparamagnetic (33 %) states at 300 K with notable Ms = 22 emu/g, Mr = 4 emu/g & Hc = 130 Oe and blocking of most of the nanoparticles of MCNF below 300 K. The coercivity followed the size-modified Kneller law for ferrimagnetic nanoparticles and the saturation magnetization abides the Bloch law. Moreover the frequency-dependent ac-susceptibility investigations revealed two magnetic transitions: (i) A transition at ∼ 330 K in the low frequency data attributed to the relaxation of blocked particles of bigger sizes under the superparamagnetic (SPM) regime and (ii) an irregularity at low temperatures is assigned to surface spin glass freezing. Surface spin glass freezing was further affirmed by the ageing experiments and dynamic scaling law. Furthermore, even the best fit to the dynamic scaling couldn't assert the existence of conventional spin glass phase due to slower spin-flip time of surface spins. A soft ferrimagnetic core of MCNF is enveloped with disordered surface spins, which manifest spin glass state. Concurrently, the findings of exchange bias at 30 K and training effect at 6 K affirmed that MCNF nanoparticles are presenting themselves as FM core- SG shell system. Our experimental findings suggested magnetic inhomogeneities comprised of superparamagnetism, ferrimagnetism and disordered surface spin glass state in the non-stoichiometric MCNF.

Layerwise models for supersonic flutter analysis of viscoelastic sandwich panels with curvilinear fibre composite skins

In this work, an assessment of layerwise finite element models for supersonic flutter analysis of soft core viscoelastic sandwich panels is presented, making use of various kinematic descriptions involving shear deformation theories and Lagrange z-expansions with thickness stretching, progressively refined to render numerically accurate and computationally efficient solutions. Numerical applications of sandwich panels include either viscoelastic or purely elastic core with skins of metal or laminated composite, using unidirectional or curvilinear fibres, considering thin and moderately thick panels, with core thickness ratios ranging from narrow to wide cores. A comprehensive assessment of the models predictive capabilities in free vibration analysis is carried out by comparison with three-dimensional exact solutions and numerical methods available in the literature. Even though it is concluded that layerwise first-order modelling, with no thickness stretching, ensures a fair compromise between numerical accuracy and computational efficiency in the aeroelastic flutter analysis of thin sandwich panels, layerwise high-order theories accounting for thickness stretching are rather necessary for the proper modelling of moderately thick sandwich panels, with either viscoelastic or purely elastic core.

Microfluidic generation of bioinspired core–shell structured microfibers for cultured meat

The simulation of traditional meat characteristics is critical to cultured meat production. We propose bioinspired microfibers with solidified alginate shells and porcine muscle stem cell (PMSC) loaded hydrogel cores. The core–shell structure not only provide a spatially confined environment for directional cell alignment, but also enable the design of a soft hydrogel core to facilitate cell migration and mutual fusion. The myogenic differentiation and muscle protein synthesis of PMSCs in microfibers are thus significantly promoted, which even lead to the spontaneous contraction of cellular microfibers. Microfibers are assembled into bulk cultured meat tissues by integrating the microfluidics and 3D printing technologies. Benefiting from the efficient cell myogenesis, the appearance, texture, and protein composition of the constructed cultured meat are similar to those of native pork. By combining multiple microfluidic devices into the printing system, the simultaneous printing of multiple pieces of cultured meat can be realized as well. These features show the broad prospect of the proposed microfibers in efficient and large-scale production of cultured meat with traditional meat characteristics.

Free Vibration of Functionally Graded Material Sandwich Plates with Soft Core

Free Vibration of Functionally Graded Material Sandwich Plates with Soft Core

Solving the Film Formation Dilemma: Blends of Soft Core–Hard “Shell” Particles

Solving the Film Formation Dilemma: Blends of Soft Core–Hard “Shell” Particles

Complete genome sequence and comparative analysis of a Vibrio vulnificus strain isolated from a clinical patient.

Vibrio vulnificus is an opportunistic, global pathogen that naturally inhabits sea water and is responsible for most vibriosis-related deaths. We investigated the genetic characteristics of V. vulnificus isolated from the clinical blood culture specimen of a patient with hepatitis B virus cirrhosis in 2018 (named as V. vulnificus VV2018) by whole genome sequencing (WGS). VV2018 belonged to a novel sequencing type 620 (ST620) and comprised two circular chromosomes, containing 4,389 potential coding sequences (CDSs) and 152 RNA genes. The phylogenetic tree of single nucleotide polymorphisms (SNPs) using 26 representative genomes revealed that VV2108 grouped with two other V. vulnificus strains isolated from humans. The pan-genome of V. vulnificus was constructed using 26 representative genomes to elucidate their genetic diversity, evolutionary characteristics, and virulence and antibiotic resistance profiles. The pan-genome analysis revealed that VV2018 shared a total of 3,016 core genes (≥99% presence), including 115 core virulence factors (VFs) and 5 core antibiotic resistance-related genes, and 309 soft core genes (≥95 and <99% presence) with 25 other V. vulnificus strains. The varG gene might account for the cefazolin resistance, and comparative analysis of the genetic context of varG revealed that two genes upstream and downstream of varG were conserved. The glycosylation (pgl) like genes were found in VV2018 compared with Pgl-related proteins in Neisseria that might affect the adherence of the strain in hosts. The comparative analysis of VV2018 would contribute to a better understanding of the virulence and antibiotic resistance profiles of V. vulnificus. Meanwhile much work remains to be done to better understand the function of pgl-like genes in V. vulnificus.

Core/shell bimagnetic microwires with asymmetric shell: MOKE and FMR behavior

A new type of multilayered microwires with a partially covering shell and bimagnetic character is here introduced. A precursor Pyrex-coated Fe-based microwire was fabricated by quenching and drawing technique, and subsequently an outer magnetic shell was deposited by magnetron sputtering covering only partly the precursor microwire (contrary to previously reported fully covered wires). Particularly, an amorphous magnetically soft core (Fe77.5B15Si7.5) was selected in this study and a polycrystalline shell (FeNi soft or Co hard) covered only half of microwire along the axis. After performing a geometry and surface roughness characterization, their surface azimuthal static magnetic profile was determined by magneto-optic Kerr-magnetometer, MOKE. In addition, the ferromagnetic resonance, FMR, response was experimentally studied by Network Analyzer up to 16 GHz frequency where the contributions of internal core and partly covering shell are analyzed and compared with fully covered microwires. The magnetoelastic behavior of such asymmetric bimagnetic microwires open up new perspectives to employ such materials for sensing and biomedical tweezer applications.

On infinite group velocity in composite plates

The analytical and geometrical conditions for the possible appearance of the infinite group velocity (IGV) points belonging to the dispersion curves of Lamb waves propagating in traction-free plates are studied by a combined method comprising Cauchy sextic formalism and the exponential fundamental matrix method. According to the obtained geometrical condition, the IGV corresponds to the coincidence of a tangent line to any of the dispersion curves with a straight line passing through the origin. The developed technique is demonstrated by applying to the analysis of Lamb wave dispersion in three-layered plates with a soft inner core.

Refined quasi-3D shear deformation theory for buckling analysis of functionally graded curved nanobeam rested on Winkler/Pasternak/Kerr foundation

In the present work, a novel refined three-variable quasi-3D shear deformation theory incorporates a correction factor is developed to analyze the buckling behavior of multi-directional functionally graded (FG) curved beams. The proposed displacement field is formulated in accordance with the Euler-Bernoulli beam theory. The research investigated two types of coated Functionally Graded (FG) nanobeams: Hardcore (HC) FG curved nanobeams and Softcore (SC) FG curved nanobeams. Three different material distributions are taken into consideration: a bidirectional material distribution referred to as “2D-FG,” a unidirectional transverse material distribution known as “T-FG,” and a unidirectional axial material distribution called “A-FG.” Eringen’s nonlocal elasticity theory is employed to capture small-scale effects. The total potential energy principle is utilized to derive the equilibrium equations of curved nanobeams. A novel solution, utilizing Galerkin’s method, has been developed to effectively address a range of boundary conditions. The curved FG beam is supported by an elastic foundation following the Winkler/Pasternak/Kerr model. A comprehensive analysis has been conducted to examine the impacts of various FG schemes, curved beam geometry, nonlocal parameter, elastic foundations, and various boundary conditions on the dimensionless critical buckling loads. This analysis aims to provide a comprehensive understanding of how each of these factors influences the critical buckling loads of the nanobeams.