We perform behavioral analysis of natural gas and SYNGAS molecules interacting with a carbon nanotube at an initial simulation temperature of 300 K, and under a uniform electric field, as a gas sensor system using molecular dynamics. Each gas molecule was relaxed for 50 ps outside the carbon nanotube, describing each possible arrangement. A constant external electric field was applied longitudinally to this system, along the length of the carbon nanotube, promoting an evanescent effect, capable of trapping each gas molecule by spinning around it. The electric field intensities were from a range of 10–8 a.u. to 10–1 a.u. were performed, and mean orbit radii and thermodynamic properties were estimated. The results indicate that an external uniform electric field and van der Waals interactions in a carbon-derived nanotube are sufficient to create an evanescent field of attractive potential, presenting it as a practical system for detecting through temperature and ray analysis, of the GN molecules and the SYNGAS.
Noble metals gold NPs are produced by pulsed (“Q-switched, 1064 nm Nd: YAG”) ablation of gold foil dipped in doubles distilled water DDW by laser. (PLAL) the process was performed with laser energy in range (400–700) mJ at (90 pulses, wavelength 1064 and room temperature and liquid depth 9 mm. The influence of laser energies have been tested structurally, optically and morphologically and examined by using scanning electron microscope (SEM), UV-visible spectroscopy and atomic force microscope (AFM). The absorption spectra of AuNPs are prepared in water piercing and solitary peaks nearby 518 and 524 nm, demonstrating the assembly of clean and sphericals in shape AuNPs with the middling size in the range of (20–50) nm. SEM and AFM have established all the measurements of size.
Low back pain is one of the most commonly encountered musculoskeletal diseases in modern society, and it is estimated that about 70 to 85% of the population has experienced low back pain. Individuals with low back pain usually modify the pattern of movement during gait to protect themselves, that is, they use different strategies of trunk movement and lower limbs protectively to avoid painful movements. However, in the long term, these repeated and prolonged changes and tensions during gait can cause mechanical dysfunctions, overloading the lumbar vertebral column and consequently causing damage. The objective of this study was to analyze gait kinematics in patients classified in the low back pain subgroups and to identify the possible biomechanical changes of the movement in these individuals. It is a cross-sectional observational study composed of a convenience sample of 17 patients, 24.6 ± 3.0 years old, from the Federal University of Santa Catarina located in the city of Araranguá-SC. Individuals classified in the manipulation subgroup obtained better results in the length of the gait, hip angle in the initial phase of gait and gait speed. The directional preference group obtained a smaller step length and passed. The traction group had the longest running time compared to the other subclassification groups of low back pain. Through the present study, it is possible to affirm that patients with nonspecific chronic low back pain present changes in gait. The individuals classified in the directional preference subgroup were the ones that had the lowest performance in the analyzed variables when compared to the subgroups of traction, manipulation and stabilization.
Turbine generator shaft torsional oscillations is an interdisciplinary power system dynamic problem as it involves mechanical and electrical engineering. Torsional oscillations occur in the mechanical for electrical reasons. Torsional oscillations cause fatigue life expenditure of the mechanical shaft system. There have been great motivations to mitigate the shaft torsional oscillations especially when unrestricted high speed reclosure (HSR) is utilized on the overhead transmission lines emanating from a generation station. Mitigation of torsional oscillation compromises between the use of HSR and preserving the mechanical integrity of the involved turbine generator set. Therefore, braking resistor (BR) controlled by fuzzy logic controller is presented in this paper as a low cost, reliable mean for torsional oscillations mitigation. BR was first utilized for the system transient stability enhancement. It serves as an extra load capable of dissipating extra generated power in case of system severe faults close to a generation station consequently prevents generator pole slipping conditions. IEEE 3 machine 9 bus system is adopted in this paper to test the effects of BR on shaft torsional oscillations mitigation in interconnected power system. Comparative simulation studies between the unsuccessful reclosure with and without fuzzy controlled BR prove the effectiveness of the scheme for mitigation of torsional oscillations significantly.
Thin films of Se90Cd10–xSbx (2 ≤ x ≤ 8) of thickness 0.4 microns were prepared on ultra-clean glass substrate by thermal evaporation technique. The vacuum level was 10–6 torr. This paper intends to investigate the impact of Sb concentration on the optical characterization. XRD measurement has been done to investigate the Structural characterization of the prepared thin films. XRD result indicates the prepared thin have amorphous nature. To analyze the optical characterization of the thin films the absorption spectra were recorded over 400–1100 nm wavelength range. In the present study the optical absorption follows direct allowed transition. An increase in photon energy causes an increase in absorption coefficient while extinction coefficient has been found to increase with an increase in frequency of the photons i.e., deceases with increase of wavelength. Optical bandgap (Eg) of thin films have been studied and an increase in it has been recorded with increasing Sb concentration.
Environment sensitive polymers have great potential in various applications. These polymers are self-regulated. In self-regulated schemes, the controlled or limited variable is noticed, along with the output of the system that is adjusted according to the variables. Through feedback information and without external involvement, the released rate is controlled. To control the rate mechanisms, the self-regulated schemes use many methods as, enzyme substrates reactions, pH-responsive drugs solubility, antibody interactions, competitive bindings, and metal concentration dependent hydrolysis. The roles of environment sensitive polymers in self-regulated drug delivery systems are discussed in this paper.
In the present paper, the aim is at studying the kinematic process and deposit geometry of a potential rock avalanche in Italy. The rock fragmentation and the effect of different bonding strengths are evaluated. To simulate the sliding and destruction of the potential rock avalanche, a 3D discrete element software EDEM is employed. The results suggest that a dam will be formed nearly 70 sec after the avalanche occurs, and the maximum average velocity of the avalanche reaches over 40 m/s. The whole process can be split into 4 stages (instability, acceleration, fast sliding and decelerate deposition). There are three possible paths for debris to slide. The major path located in the middle, and the other 2 only have few rock debris. Furthermore, small bonding strength model of the discrete element method (DEM) applies to the simulation of the potential rock avalanche disasters, allowing the sliding in a form of debris avalanche with good liquidity.
Structural and thermal measurements have been performed in glassy Se78Te18M4 (M = Sb and Ge) alloys to study the effect of Sb and Ge additives on the kinetics of glass transition and crystallization. Kinetic parameters of glass transition and crystallization such as the activation energy of glass transition (Eg), the activation energy of crystallization (Ec) have been determined using different non-isothermal methods. It was found that Ge was more suitable dopant for phase change memory (PCM) devices due to its low activation energies as compared to Sb dopant.
Aluminum Nano Metal Matrix Composites are extensively utilized for high-performance operations such as branches of engineering and medicine due to their enhanced physical and mechanical properties compared to traditional metals and metal alloys. In this research, Al6063 alloy was reinforced with 15 nm sized Magnesium Oxide particles in different weight percentages. The development of Nano Metal Matrix Composites (NMMC) was completed through stir casting method at 750 °C temperature. The fabricated Nanocomposites were examined for the mechanical properties and impact of drilling parameters on chips and burr formation. The input parameters adopted for analysis were speed, feed, and material of the drill tool. The drill tools made of HSS & TiN coated HSS were utilized in the drilling of NMMC. The influence of process parameters on chips and burr formation were analyzed and optimized the process parameters for better output intended for this experimental environment through the Artificial Immune Algorithm technique.
Iron, the most ubiquitous of the transition metals and the fourth most plentiful metal in the Earth’s crust, is the structural backbone of our modern infrastructure. It is therefore ironic that as a nanoparticle, iron has been somewhat neglected in favour of its own oxides as well as other metals such as cobalt, nickel, gold, and platinum. This study reports the green synthesis of iron nanoparticles using a bioflocculant and their characterization. The as-synthesised materials were characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric analysis (TGA) and UV-Vis absorption spectroscopy. Spherical morphology was observed for the as-synthesised iron nanoparticles (FeNPs) and elemental analysis indicated iron with 17.31%. XRD studies revealed the broader peaks at 24°, 29°, 30°, and 35° 2θ for the as-synthesised iron nanoparticles indicating the nano sized particles. FT-IR spectra showed the bands at 3154 cm-1 (bioflocculant) and 3244 cm-1 (iron nanoparticles) representing the presence of hydroxyl (–OH) and amine (–NH2) functional groups.
Density-functional theory calculations of the magnetic shielding for nuclear magnetic resonance provide an important contribution to understand the experimental values obtained in laboratory for chemical shifts present in the samples. From of a comparative of the performance of ten hybrid functional within of the framework of the density-functional theory using 10 different hybrid functionals with 3-21G (B1), 6-31G(d) (B2) and 6-31+ G(d, p) (B3) basis set, with intuit of evaluating of performance of the 13 C nuclear magnetic resonance from a representative of the terpene class and a heterocyclic compound, (–)-loliolide ((7aR)-6-hydroxy-4,4,7a-trimethyl-6,7-dihydro-5H1-benzofuran-2-one). This molecule, satisfactorily, represents the main structure of this class, with conformational freedom, optical activity and a benzofuran nucleus. The ωB97X-D, MPW1K and HSEH1PBE functionals presented the best calculation performance. It is interesting to note that after the use of linear regressions all root mean square error values for ωB97X-D were lower than 3 ppm. These are 2.91 ppm (B1), 2.46 (B2) ppm and 2.62 ppm (B3). The information contained in this work can be used for the assignment of experimental nuclear magnetic resonance spectra and will motivate further studies involving the theoretical calculation of the chemical shift of 13C.
At nano level, materials show very interesting physical properties with the variation of shape and size. The prediction of this behaviour has been a burning issue in the recent years in the scientific community as well. Even the physical properties of these materials are poorly investigated experimentally. To explain the sharp change in the properties of metals, as reported by some investigators, at their nanolevel, different models have been proposed. It is observed that in their theoretical prediction, they have not considered the exact arrangement of atoms in the lattice. In our attempt to understand the behaviour of the nanomaterials, we have studied the melting temperature of some nanosolids having face centered cubic lattice such as Aluminium (Al), Copper (Cu), Paladium (Pd), Platinum (Pt) and Gold (Au), considering different shapes with their sizes ranging from 30 nm to more smaller dimensions. For modelling analysis, we have considered the very basic and fundamental relation of cohesive energy with melting temperature along with modification with two realistic physical quantities-packing fraction and particle shape factor simultaneously to account the arrangements of atoms within the nanoparticle and on the surface as well. Our study shows that there is a very marked change in the melting temperature of the metallic nanosolids below 20 nm. Although in the earlier reported works, it has been claimed that this variation occurs at somewhat higher values. In this variation, the tetrahedral structure exhibits maximum variation of melting temperature while spherical one corresponds to the minimum change. In case of gold, our simulated data has been compared with available experimental values which is found in good agreement with it. This agreement between experimental and computed data validates our proposed model for the prediction of melting temperature of nanoparticles at varying dimensions viz, shape and size. Thus our proposed modification in the existing model is more appropriate in the prediction of melting point of nanoparticles with its varying shape and size.
The entity of intelligent building is integrated with diversified service function of control, automation and communication of devices in its environment, and to perform them in joined manner via intelligent tasks. Rapid improvement in sensor technologies and advancement in electronics have given rise to heterogeneous systems growth in intelligent building. Most of these subsystems are dissimilar and not intended to perform interoperation task. Consequently, it is rather difficult to perform decision making with the combination of these systems considering the variety of data that are not efficient in adapting to the changing environment. One of the recent decision support solutions provided was Left–right Hidden Markov Model (LR-HMM) which uses left-right algorithm to improve accuracy of prediction based on single timely decision. However, it leads to low accuracy when multiple timely decisions are performed. Therefore, to ensure timely decision, the accuracy of prediction should be improved when performing multiple decisions. We propose a new decision model to improve performance in such situations. The goal is to improve the accuracy of prediction when multiple decisions are performed. Experiments are conducted to evaluate the performance of the proposed Re-estimated Ergodic Hidden Markov Model (RE-HMM), and show that it improves the average accuracy compared with LR-HMM. It is examined when tested on the Local Area Network (LAN) settings.
Lately marble is viewed as most significant beautifying construction materials. MP is which severalty impact on nature and medical issues. Marble powder materials are a fine powder. It is developed from chopping, molding and washing process. The creation of cement is expanding about 3% yearly. The creation of 1 ton of cement frees around 1 ton of CO2 to the air. This explorationmeans to intend the impression of using MP as in part substitution of cement. Cement which is one of constituents utilized in the creation of concrete has gotten costly and scant because of which development cost increments. In present investigation cement has been partially replaced with marble powder in five different percentage mixes of 0%, 5%, 10%, 15% and 20% weightiness of cement content in concrete. The key factor taken into concern is proportion of MP concrete is tested for workability, compressive strength, flexural strength and tensile strength.
In depth understanding of resistivity of metals is of utmost importance for optimizing circuit designs and electrical systems. In this study, we investigated the relation between film thickness (in the range of 25−350 nm) and film resistivity of Cu thin films, with respect to thin film temperature sensors. The films were deposited in a vacuum deposition chamber over pyrex substrates and the film resistances were measured using 4 point probe technique. The empirical relationship established by Lacy has been used along with our experimental results in order to calculate the constants relating the filmsubstrate compatibility, which influences the change of resistivity with thickness.
This study analyzed the effects of photobiomodulation, on wrist extensor muscles when applied before a fatigue protocol. Twenty-eight men participated in a crossover, blinded, and controlled trial. Subjects performed grip dynamometry associated with superficial electromyography of the extensor carpi radialis, extensor carpi ulnaris, and flexor digitorum superficialis, which was used to evaluate muscle recruitment pattern by median frequency. The initial assessment was performed with a onerepetition maximum test. Twenty-four hours later the allocation was performed in two moments, and randomization was initially performed with 28 volunteers, divided between the two groups: control group, and the Low-Level Laser Therapy (30 mW, 0.06 cm2, 20 J/cm2, 1.2 J per point, and total energy of 10.8 J). Median frequency demonstrated Extensor Carpi Ulnaris fatigue in the control group as well as when compared after the fatigue protocol in the laser group. Exhaustion time was greater in the laser group and the fatigue protocol was effective at decreasing grip strength, with significant difference in the control group (p < 0.05). After the fatigue protocol, Low-Level Laser Therapy was effective in maintaining grip strength to increase exhaustion time and does not promote alterations in Median Frequency behavior at wrist extensor muscles.
The current article demonstrates the geoeffectiveness of solar flare associated Coronal mass ejection (CME) accompanied with Deca-hectometric (DH) type II radio bursts by comparing the set of events in the rising phase of solar cycle 23rd (1996–2001) and 24th (2009–2014). Our observations are: (i) Solar cycle 23rd have high Dst index than the solar cycle 24th except for the year 1999. (ii) Dst has its peak between 3rd to 5th day after the CME onset for both the solar cycles. (iii) The correlation coefficient between Interplanetary magnetic fields (IMF) and Dst is good for both the solar cycles. (iv) Solar cycle 23rd have very strong correlation between CRI and Dst as compare to solar cycle 24th. Thus, our predictions show that solar cycle 23rd is more geoeffective than solar cycle 24th.
Additive manufacturing (AM) is an advanced technique to fabricate a three-dimensional object while utilizing materials with minimal wastage to produce complex shape geometries. This technique has escalated practically as well as academically, resulting in a wide range of utility in the current global scenario to ease the manufacturing of complex and intricate objects with the use of various materials, depending upon the properties and availability of the same. Every industries wants to achieve the sustainability, easily can be possible through this manufacturing process. Due to the scope for a large number of design, material and processing combinations, a detailed outlook to how additive manufacturing can be optimized for a highly sustainable and standardized manufacturing practice needs to be assessed and understood. This paper discusses the core knowledge available regarding this manufacturing process and highlights the different processes related to this technique through review of various research papers. And also discuss the sustainability of important additive manufacturing process. Along with the fundamental analysis of this process, the paper also discusses the various attributes of the process and the growth with respect to the latest trends and techniques currently used in industries.
In this manuscript, we have analyzed Celebrated Blasius boundary problem with moving wall or high speed 2D laminar viscous flow over gasifying flat plate. To find the way out of this nonlinear differential equation, a version of semi-analytical homotopy perturbation method has been applied. It has been observed that the precision of the solution would be achieved with increasing approximations. On comparison with literature, our solution has been proven highly accurate and valid with faster rate of convergence. It has been revealed that the second order approximate solution of Blasius equation in terms of initial slope is obtained as 0.33315 reducing the error by 0.32%.
Chalcones have attracted the attention of researchers for decades, they are biologically classified as secondary metabolites of low molecular weight. These are considered as the precursors of flavonoids and they are widely distributed in plants such as vegetables, fruits, teas and spices. It has been demonstrating that chalcones possess many important bioactivities including properties of antioxidants and other evidence of its potential beneficial effects on health. Chalcone compounds and its derivatives have been showing a growing interest in the therapeutic properties. Nuclear magnetic resonance (NMR) spectroscopy is one of the most important tools for determining the structures of organic molecules. In the work present a 13 C Nuclear magnetic resonance chemical shift protocol of chalcones and derivative based on the application of scaling factor with chalcone molecules. This protocol consists of using density functional theory with gauge-including atomic orbital method to calculating 13 C chemical shifts and the application of a parameterized scaling factor in order to ensure accurate structural determination of chalcones and derivative.
