Conventional Analytical Method Research Articles

Accurate analysis of harmonic Hall voltage measurement for spin\u2013orbit torques

An accurate method is developed to extract the spin–orbit (SO) effective fields by analyzing harmonic Hall voltage measurements and deriving detailed analytical equations that consider both the z component of the applied magnetic field and the second-order perpendicular magnetic anisotropy. The method is tested by analyzing the results of a macrospin simulation. The SO effective fields that are extracted from the analysis are consistent with the input SO effective fields that are used in the macrospin simulation over the entire range of the polar magnetization angle and for a wide range (0–2) of the ratio of the planar to the anomalous Hall voltage considered in this study. The accuracy of the proposed method is demonstrated via a systematic study that involves comparing its results with those of a conventional analytical method.

Parametric and Comparative Study of a Flexible Retaining Wall

This paper presents design of a self-stabilizing retaining diaphragm wall, using conventional analytical calculation method based on subgrade reaction coefficient and by numerical method with finite elements method FEM can lead to various uncertainties. Hence, engineers have to calibrate a computational strategy to minimize these uncertainties due to numerical modeling. For both two methods, this paper presents various simulations with the structure installed into the supported ground without surcharge. For the first method, the analysis has investigate the influence of main factors such as the wall rigidity, the different stages of excavation, the Young’s modulus, the cohesion and internal friction’s angle of the soil. For the FEM method, two constitutive soil models are used such as Mohr-Coulomb MC and hardening soil model HSM. In case of the last model HSM, the variation of required and additional factors for the model was investigated as well as secant modulus stiffness Eref50, unloading and reloading stiffness modulus Eur, power factor m and Over-consolidated ratio OCR. The results from of the various simulations carried out are confronted with other experimental and numerical results [4]. Avery good coherence results are showed.

Stability of Very Flexible Aircraft with Coupled Nonlinear Aeroelasticity and Flight Dynamics

This paper presents a framework for analyzing the stability characteristics of a very flexible aircraft, simultaneously taking into account nonlinear aeroelasticity and flight dynamics. Here, the dynamics formulation is deduced by combining the displacement-based geometric nonlinear finite element method with the nonplanar panel method, and it is linearized carefully around the trim configuration with large static deformations. A mean axis system, the origin of which is at the center of mass of the aircraft trim configuration, is used to eliminate the inertial coupling. The methodology in this paper generalizes the conventional linear analytical method to deal with stability problems of nonlinear systems and can be easily integrated into the industry design process and complex structures. The numerical results for a very flexible flying wing indicate the necessity to consider aeroelasticity and flight dynamics integrally, because the gap between the frequencies of rigid-body motions and elastic modes tends to be narrower and the coupling effects may worsen the envelope.

The Displacement Solution of Existing Tunnel and Ground by Traversing Construction by Stochastic Medium Theory

Tunnel excavation will cause the displacement of ground, which will lead to the displacement of the existing tunnel. Because of the great difference between the tunnel’s rigidness and the ground’s rigidness, the conventional analytical method cannot calculate the existence of different stiffness of the stratum displacement field. The stiffness of the existing tunnel is equivalent by stochastic medium theory. A computing model which includes the new tunnel and rock mass and the existing tunnel is build. Taking Beijing metro line 10 crossing metro line 1 as an example, with this method, the influence of the existing and ground is studied. The results show that the calculated results are in good agreement with the experimental results, and the analytical solution can well explain the barrier and diffusion of the existing tunnel. The research results provide a new analytical method for the calculation of the existing tunnel and stratum settlement caused by the construction of the tunnel.

Efficient Computation of Exchange Energy Density with Gaussian Basis Functions.

Density functional theory (DFT) is widely applied in chemistry and physics. Still it fails to correctly predict quantitatively or even qualitatively for systems with significant nondynamic correlation. Several DFT functionals were proposed in recent years to treat the nondynamic correlation, most of which added the exact exchange energy density as a new variable. This quantity, calculated as Hartree-Fock (HF) exchange energy density, is the computational bottleneck for calculations with these new functionals. We present an implementation of an efficient seminumerical algorithm in this paper as a solution for this computational bottleneck. The method scales quadratically with respect to the molecular size and the basis set size. The scheme, exact for the purpose of computing the HF exchange energy density, is favored for medium-sized basis sets and can be competitive even for large basis sets with efficient grids when compared with our previous approximate resolution-of-identity scheme. It can also be used as a seminumerical integration scheme to compute the HF exchange energy and matrix on a standard atom-centered grid. Calculations on a series of alanine peptides show that for large basis sets the seminumerical scheme becomes competitive to the conventional analytical method and can be about six times faster for aug-cc-pvtz basis. The practicality of the algorithm is demonstrated through a local hybrid self-consistent calculation of the acenes-20 molecule.

Form-finding analysis of suspension bridges using an explicit Iterative approach

This paper presents an explicit analytical iteration method for form-finding analysis of suspension bridges. By extending the conventional analytical form-finding method predicated on the elastic catenary theory, two nonlinear governing equations are derived for calculating the accurate unstrained lengths of the entire cable systems both the main cable and the hangers. And for the gradient-based iteration method, the derivation of explicit calculation for the Jacobian matrix while solving the nonlinear governing equation enhances the computational efficiency. The results from sensitivity analysis show well performance of the explicit Jacobian matrix compared with the traditional finite difference method. According to two numerical examples of long span suspension bridges studied, the proposed method is also compared with those reported approaches or the fundamental criterions in suspension bridge structural analysis, which eventually confirms the accuracy and efficiency of the proposed approach.

A Hybrid Analytical and Finite Element Method for Mid-Frequency Vibration Analysis of Plate Structures with Discontinuities

A hybrid analytical and numerical method is presented for the mid-frequency vibration analysis of a class of plate structures with discontinuities based on the concept of structural partitioning. The type of structures considered includes rectangular plates with internal property discontinuity, homogeneous but non-rectangular plates, or built-up structures composed of rectangular homogenous plates with complex joints. Compared with the conventional finite element (FE) method, the present method has the advantage of high accuracy and high efficiency in the analysis of mid-frequency vibration of the structures of concern. The main idea of the proposed approach is to divide the whole structure into uniform rectangular plate regions and other non-rectangular regions. The vibration behavior of the rectangular regions is accurately and efficiently described by analytical wave solutions so that the FE modeling for these regions is not necessary. The other non-rectangular regions are modeled by the conventional FE method. The analytical waves used to describe the rectangular regions are obtained by the symplectic method, thereby avoiding the limitation of the conventional analytical method in dealing with plates having two opposite edges simply supported. By enforcing the displacement continuity and force equilibrium at the connection interfaces, the dynamic coupling is established between the rectangular regions described in terms of the analytical waves and the regions modeled by FEs. Furthermore, the hybrid solution formulation for the mid-frequency vibration of the entire structure is proposed. The high accuracy and efficiency of the present method are demonstrated by several numerical examples, with the effect of element size of the FE regions investigated. Finally, the applicability of the proposed method is analyzed.

Evaluation of marbling traits by X-ray computed tomography in Hungarian Simmental bulls

Marbling is an economically important factor in many beef carcass grading schemes. This study aimed to evaluate marbling traits of longissimus thoracis muscle (LT) with different methods: USDA marbling score, intramuscular fat (IMF) content by image analysis of X-ray computed tomography (CT) scans and by conventional analytical method. Bulls (n=46) were slaughtered at an average weight of 536 kg and an average age of 646 days. Mean values of EUROP fat scores varied from 2− to 2+, whereas mean values of EUROP conformation grade from O0 to R0. Average growth rate of bulls was 955 g/day. Average chemical fat content of LT varied from 2.2% to 3.1% across conformation classes, and from 2.3% to 5.0% across fat classes. Intramuscular fat content in the 12th rib and in LT on CT-scans closely correlated with chemical fat content (r=0.81 and 0.85, respectively). The highest frequency of USDA marbling score was ‘small’ (55.2%), followed by ‘slight’ (25.5%), ‘modest’ (17%) and ‘moderate’ (2.1%). Computed tomography scans of LT can be used for the evaluation of marbling in Hungarian Simmental cattle. Bulls with higher growth rate had lower marbling level in LT (r=−0.4 to −0.5). EUROP conformation and fat scores have no relationship with marbling traits in this specific cattle population.

Shaking Table Test of a RC Frame with EPSC Latticed Concrete Infill Wall

The expansive polystyrene granule cement (EPSC) latticed concrete wall is a new type of energy-saving wall material with load-bearing, insulation, fireproof, and environmental protection characteristics. A series of shaking table tests were performed to investigate the seismic behavior of a full-scale reinforced concrete (RC) frame with EPSC latticed concrete infill wall, and data obtained from the shaking table test were analyzed. The experimental results indicate that the designed RC frame with EPSC latticed concrete infill wall has satisfactory seismic performance subjected to earthquakes, and the seismic responses of the model structure are more sensitive to input motions with more high frequency components and long duration. The EPSC latticed concrete infill wall provided high lateral stiffness so that the walls can be equivalent to a RC shear wall. The horizontal and vertical rebar, arranged in the concrete lattice beam and column, could effectively restrain the latticed concrete infill wall and RC frame. To achieve a more comprehensive evaluation on the performance of the RC frame with latticed concrete infill walls, further research on its seismic responses is expected by comparing with conventional infill walls and nonlinear analytical method.

An analytic model employing an elliptical surface area to determine the gaseous thermal conductance of uncooled VOx microbolometers

This work presents a detailed overview of the analytic methods for calculating the beam and gaseous thermal conductance components associated with uncooled VOx microbolometers. The conventional method to calculate the gaseous component relies on the assumption that the entire plate is maintained at a uniform temperature, thus the surface area of the plate is used for the calculation. We have observed using an industry leading multiphysics simulator that this assumption is not strictly true for VOx microbolometers as the conduction pattern exhibits an elliptical shape. Based on this, we have developed and propose an analytic method that employs an elliptical surface area scaled appropriately with the device dimensions to obtain an estimate of the average temperature conduction pattern. Prototype devices were manufactured and experimentally characterised. The devices exhibit thermal conduction characteristics comparable to those in literature and industry, and we could achieve 0.5μW/K under vacuum conditions and 15μW/K at atmospheric pressure with a TCR of −1%/K. However, both simulated and experimental result sets of the gaseous thermal conductance exhibit large deviations from the conventional analytic method, on average approximately 40%. The proposed method reduces this average error significantly to less than 10% when compared to the simulated results.

Progress in the Development of Reaction-Based Sensors for Detection of Acrolein in Biological Samples

Acrolein, a highly toxic α,β-unsaturated aldehyde, occurs as pollutant in the environment (e.g., tobacco smoke and exhaust gas) and ubiquitously generated in biosystems (e.g., lipid peroxidation process and metabolism of polyamine or amino acids). High accumulation of acrolein in the body is often linked pathologically with several oxidative stress-related diseases, including cancer and Alzheimer’s. Accordingly, acrolein holds great potential as key biomarker in oxidative stress-related diseases, and direct measurement of acrolein in biological samples is becoming important to provide information for diagnosis and therapeutic purposes. The available conventional analytical method for detection of acrolein, e.g., high-performance liquid chromatography (HPLC) analysis after derivatization with 3-aminophenol under harsh reaction conditions, is not suitable for high-throughput assay and inconvenient for measurement in clinical practice. A monoclonal antibody can be used for detection of acrolein–lysine adducts; however, this method is time-consuming and expensive. Consequently, developing new analytical tools that are straightforward, cost-effective, and selective for acrolein detection in live cells remains highly important for the diagnosis and therapeutic treatment of oxidative stress-related diseases. In this review, we will discuss several commonly used classical methods for detecting acrolein from biological samples, and describe our recent findings on the simple but robust method for detecting and visualizing acrolein generated by live cells in the context of oxidative stress processes or introduced via environmental exposure.

Determining double-K fracture parameters of concrete only by the measured peak load

The peak load and critical crack-mouth opening displacement are two essential parameters that should be measured in the conventional analytical method to determine double-K fracture parameters of concrete. In this study, we propose a method to determine the double-K fracture parameters only by using the measured peak load so that both the measurement of critical crack-mouth opening displacement and the limit to require three or more distinct specimens in the conventional peak load method can be avoided. Furthermore, double-K fracture parameters are computed using the conventional analytical method and proposed method respectively through the three-point bending test and the findings in the scientific literature. The results show that the fracture parameters of the double-K fracture model can be determined by using this proposed method without any appreciable error.

Evaluation of the susceptibility of coal to spontaneous combustion by a TG profile subtraction method

It is imperative to have an in-depth understanding of the intrinsic reaction between coal and oxygen during low-temperature oxidation, as the reaction is the main source responsible for the self-heating and spontaneous combustion of coal. As low-temperature oxidation of coal involves a series of physical and chemical process and many parallel reactions, it is difficult to directly investigate the intrinsic reaction between coal and oxygen by conventional analytical method. Thermogravimetric analysis (TGA) was used to investigate the intrinsic reaction between coal and oxygen based on the mass change. By means of the subtraction analysis method of TGA, the TG-subtraction curves were obtained by subtracting the TG-N2 curves from the TG-air curves. The results indicate that a TG-subtraction curve can better reflect the intrinsic reaction of coal oxidation than a TG-air curve by eliminating the influence of evaporation of water and thermal decomposition of inherent oxygen-containing groups. In terms of the rate of mass increase, the intrinsic reactions can be divided into three stages: slow oxidation stage, advanced oxidation stage and rapid oxidation stage. The activation energy at each of the stages, obtained by Coats and Redfern’s model, can be used to as a technical parameter to evaluate the proneness of coal spontaneous combustion. The optimum experiment conditions were also developed to study low-temperature coal oxidation with the subtraction method of TGA.

A rapid approximate inversion of extinction data for partially absorbing particles

Retrieval of particle size distribution from extinction data is solved analytically using a product kernel concept and its extension to partially absorbing materials. While a conventional analytical method overestimates the portion of large particles, the correction to the integral formula makes the solution acceptable also for larger absorbing particles. A set of numerical experiments on synthetically generated aerosol optical depths has proven improved accuracy of new formula that is simple and keeps requirements on computational time or memory consumption low enough. The numerical tests shown that original and reproduced size distributions are quite consistent, including the peak position and full width at half maximum. The main advantage of the analytical approach presented here is its easy applicability in fast sampling of rapidly evolving particulate systems, where quick estimation of modal radius or PM1.0, PM2.5 and other fractions of the aerosol population is required.

An extended analytical approach for diffuse optical imaging

In this work, we introduce an analytical method to solve the diffusion equation in a cylindrical geometry. This method is based on an integral approach to derive the Green’s function for specific boundary conditions. Using our approach, we obtain comprehensive analytical solutions with the Robin boundary condition for diffuse optical imaging in both two and three dimensions. The solutions are expressed in terms of the optical properties of tissue and the amplitude and position of the light source. Our method not only works well inside the tissue but provides very accurate results near the tissue boundaries as well. The results obtained by our method are first compared with those obtained by a conventional analytical method then validated using numerical simulations. Our new analytical method allows not only implementation of any boundary condition for a specific problem but also fast simulation of light propagation making it very suitable for iterative image reconstruction algorithms.

Rapid Mass Analysis of Reserpine and Arginine by Ion Trap Mass Spectrometer

Abstract A fast mass analysis method using digital ion trap technology was reported. The mass analysis was realized by scanning the frequency of digital RF voltage and dipole ion resonance voltage during ion injection period without the conventional ion cooling, ion resonance ejection or ion cleaning process. It can decrease about three fourth of traditional analysis time using ion trap mass spectrometry. The ion signal was optimized through the modification of frequency scanning rate, ion gate voltage and other experimental parameters. For example, an optimal mass spectroscopy of reserpine ( m / z 609) and arginine ( m / z 174) were obtained when the ion gate voltage was 9 V and the digital RF frequency was scanned from 1 MHz to 400 kHz at rate of 2385 Th s −1 . The results indicated that the obtained mass spectra were in very good agreement with conventional analytical method using ion trap mass analyzer.

Determination of double-K fracture parameters of concrete using peak load method

This paper presents application of peak load for determining double-K fracture parameters of concrete. The existing conventional experimental method and analytical methods require measurement of crack opening displacement at critical condition during fracture test whereas this measurement is not required in peak load method. Further, double-K fracture parameters are computed using both conventional analytical method and peak load method for three point bending test of specimen size range 200–500mm. The comparison of the results shows that both the fracture parameters of the double-K fracture model can be determined using peak load method without any appreciable error.

The Perception of Biological Experience in Patients With Major Thalassemia: A Qualitative Research

Background:Thalassemia Major Disease is not only assumed as a health disorder, but also a social- economic problem in many countries. The costs of transport and preparation of drugs is considered as the greatest problems for more than 63.8% of the patients’ families.This study was conducted by aiming at describing biological experience among parents of patients with Thalassemia Major.Method:The current qualitative investigation was carried out on 32 parents of patients with Thalassemia Major and by means of unstructured interview in- depth through snowball sampling technique in 2013. The data were analyzed by conventional content analytical method.Findings:The perception of biological experience of parents of patients with Thalassemia Major were classified based on participants’ experiences into three main themes including psychological experiences, physical experiences, and social experiences. 1) Psychological (mental) experiences comprise of two subclasses of the reduced self-confidence, deficient emotions and negative emotions; 2) Physical experiences consist of three subclasses of sleeping disorders, pains in various parts of body, and limited physical activity; and 3) Social experiences includes 3 subcategories of interpersonal relations, reduced income, job, and limitation in doing tasks. 4) Treatment experiences comprise of five sub-themes including 1- Shortage of drugs, blood, and filter etc; 2- Less experienced personnel; 3- Lack of training the patients’ parents by personnel in thalassemia ward; 4- Lack of visiting patients by physician in thalassemia ward; and 5- Inappropriate behavior of personnel toward patients and their parents.Conclusion:Thalassemia Major has affected negatively on several fields of health for these patients and their parents including physical, mental, economic, and social areas. Reducing these problems requires constant interventions and surveying health and medical status of these patients.

A piecewise linear model for analyzing thin film/substrate structure in flexible electronics

The conventional analytical method of predicting strain in a thin film under bending is restricted to the uniform material assumption, while in flexible electronics, the film/substrate structure is widely used with mismatched material properties taken into account. In this paper, a piecewise model is proposed to analyze the axial strain in a thin film of flexible electronics with the shear modification factor and principle of virtual work. The excellent agreement between analytical prediction and finite element results indicates that the model is capable of predicting the strain of the film/substrate structure in flexible electronics, whose mechanical stability and electrical performance is dependent on the strain state in the thin film.

Electrochemical quantification of iodide ions in synthetic urine using silver nanoparticles: a proof-of-concept.

Typical urinary iodide concentrations range from 0.3 μM to 6.0 μM. The conventional analytical method is based on the Sandell-Kolthoff reaction. It involves the toxic reagent, arsenic acid, and a waiting time of 30 minutes for the iodide ions to reduce the cerium(iv) ions. In the presented work, an alternative fast electrochemical method based on a silver nanoparticle modified electrode is proposed. Cyclic voltammetry was performed with a freshly modified electrode in presence of iodide ions and the voltammetric peaks corresponding to the oxidation of silver to silver iodide and the reverse reaction were recorded. The peak height of the reduction signal of silver iodide was used to plot a calibration line for the iodide ions. Two calibration plots for the iodide ions were obtained, one in 0.1 M sodium nitrate (a chloride-ion free environment to circumvent any interference from the other halides) and another in synthetic urine (which contains 0.2 M KCl). In both of the calibration plots, linear relationships were found between the reduction peak height and the iodide ion concentration of 0.3 μM to 6.0 μM. A slope of 1.46 × 10(-2) A M(-1) and a R(2) value of 0.999 were obtained for the iodide detection in sodium nitrate. For the synthetic urine experiments, a slope of 3.58 × 10(-3) A M(-1) and a R(2) value of 0.942 were measured. A robust iodide sensor with the potential to be developed into a point-of-care system has been validated.