Theoretical Mode Research Articles

An analytical study of sound transmission through corrugated core FGM sandwich plates filled with porous material

Abstract The main objective of this research work is focused on sound transmission loss analysis of corrugated core functionally graded material (FGM) sandwich plates filled with porous material, wherein two types of FGM sandwich structures are considered, which include one with FGM face sheets and homogeneous ceramic or metal core, and the other with FGM core and homogeneous face sheets. To model the process of sound propagation between fluid and solid, the equivalent fluid model with effective density and bulk modulus is used to describe the sound wave propagation through porous sound absorptive material. The corrugated cores are approximated as a series of uniformly distributed translational and rotational springs to link the sandwich structure. Fluid-structure coupling is considered by imposing velocity continuity condition at fluid-structure interfaces. By using the space harmonic approach and virtual work principle, the sound transmission loss is described analytically. The validity of the proposed theoretical model is verified by comparisons with previously published numerical results. Based on the developed theoretical mode, the influences of the FGM properties, gradient index, sandwich type, skin-core-skin ratios and porous material type on sound transmission loss are subsequently presented.

The City Can Speak for Itself: Notes on approaching architecture in Kinshasa

This paper deals with ways of approaching architecture within the shifting uncertainties of the giant Congolese capital. Taking a cue from Kinshasa, I will make a case for being receptive to what the current situation of built matter in urban space has to say. It is the recalcitrant aspects of Kinshasa's personality which prompted me to consider its architecture from a different perspective. During my research in the Congo, there were few archival records available and circumlocutious points of access to buildings. This forced me to consider what the sites themselves could tell. Through the example of Tour de l'Echangeur de Limete (1970 ‐ 1974), I will examine ways in which a monumental modernist structure resists being reduced to the categorizations of architectural history and theoretical modes of analysis developed in the global north because of the intervention of forces of the city.

Structural balance of multiplex signed networks: A distributed data-driven approach

This paper examines the data-driven verification of structural balance of multiplex networks by utilizing the dataset generated by the bipartite consensus dynamics adopted by each node in the network. To this end, some necessary and sufficient conditions for the structural balance of multiplex signed networks from a graph-theoretic perspective have been provided. It is also shown that a multiplex signed network is structurally balanced if and only if its related compressed network is structurally balanced. Built on the proposed theoretical results and dynamic mode decomposition technique, a distributed data-driven approach is proposed for verification of the structural balance of large-scale multiplex signed networks without relying on the explicit knowledge on network topology.

A novel nonlinear contact stiffness model of concrete–steel joint based on the fractal contact theory

The heavy-duty machine tool is usually assumed in the concrete foundation, in which the machine tool-foundation joints have a critical effect on the working accuracy and life of heavy-duty machine tool. This paper proposed a novel contact stiffness model of concrete–steel joint based on the fractal theory. The topography of contact surface exist in concrete–steel joint has a fractal feature and can be described by fractal parameters. Asperities are considered as elastic, plastic deformation in micro-scale. However, the asperities of concrete surface will be crushed when the stress is larger than their yield limit. Then, the force balance of contact surfaces will be broken. Here, an iteration model is proposed to describe the contact state of concrete–steel joint. Because the contact asperities cover a very small proportion (less than 1%), the load on crushed asperities is assumed carried by other no contact asperities. This process will be repeated again and again until the crushed asperities are not being produced under external load. After that, the real contact area, contact stiffness of the concrete–steel joint can be calculated by integrating the asperities of contact surfaces. Nonlinear relationships between contact stiffness and load, fractal roughness parameter G, fractal dimension D can be revealed based on the presented model. An experimental setup with concrete–steel test-specimens is designed to validate the proposed model. Results indicate that the theoretical vibration mode shapes agree well with the experimental variation mode shapes. The errors between theoretical and experimental natural frequencies are less than 4.18%. The presented model can be used to predict the contact stiffness of concrete–steel joint, which will provide a theoretical basis for optimizing the connection characteristic of machine tool-concrete foundation.

Spectroscopic (FT-IR, Laser-Raman and NMR) and conformational analysis on novel pyrazole β-keto ester compound

Our goal in this study is to submit a comprehensive theoretical study of novel compound. Therefore, we perused and analyzed the experimental (real form) and theoretical (gas form) vibrational frequencies for the most stable conformer of title compound. The crystallographic geometry was used for full geometry optimization, followed by a conformational analysis. The experimental FT-IR and Laser-Raman spectra of the studied molecule were taken in the region (4000-400 cm−1) and (4000-100 cm−1) in gas phase, respectively. For the most stable conformer, the vibrational modes and their assignments and optimized structure parameters (bond lengths, bond angles) were computed by using DFT/B3LYP functional and 6-311++G(d,p) basis set. Gaussian 09W software and GaussView5 interface programs were utilized for all computations. Theoretical mode assignments of the most stable conformer were obtained by using potential energy distribution (PED) with free VEDA 4 software program. The observed FT-IR and Laser-Raman spectra were compared with the calculated theoretical data. The computed vibrational frequencies of C1 conformer were also found in good agreement with the experimental results. The Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) analysis divulge the possibility of charge transfer within the molecule. The proton (1H) and carbon-13 (13C) nuclear magnetic resonance (NMR) chemical shifts were researched for the most stable conformer C1, both experimentally in DMSO-d6 and theoretically in DMSO with integral equation formalism polarizable continuum model (IEFPCM) method.

On the evolutionary status and pulsations of the recently discovered blue large-amplitude pulsators (BLAPs)

Abstract The blue large-amplitude pulsators (BLAPs) constitute a new class of pulsating stars. They are hot stars with effective temperatures of ∼30 000 K and surface gravities of log g ∼ 4.9, that pulsate with periods in the range 20−40 min. Until now, their origin and evolutionary state, as well as the nature of their pulsations, were not been unveiled. In this paper, we propose that the BLAPs are the hot counterpart of the already known pulsating pre-extremely low mass (pre-ELM) white dwarf (WD) stars, that are He-core low-mass stars resulting from interacting binary evolution. Using fully evolutionary sequences, we show that the BLAPs are well represented by pre-ELM WD models with high effective temperature and stellar masses ∼0.34 M⊙. From the analysis of their pulsational properties, we find that the observed variabilities can be explained by high-order non-radial g-mode pulsations or, in the case of the shortest periods, also by low-order radial modes, including the fundamental radial mode. The theoretical modes with periods in the observed range are unstable due to the κ mechanism associated with the Z-bump in the opacity at log T ∼ 5.25.

An Analysis of Stochastic Jovian Oscillation Excitation by Moist Convection

Abstract Recent observations of Jupiter have suggested the existence of global oscillatory modes at millihertz frequencies, yet the source mechanism responsible for driving these modes is still unknown. However, the energies necessary to produce observable surface oscillations have been predicted. Here we investigate if moist convection in Jupiter’s upper atmosphere can be responsible for driving the global oscillations and what moist convective energy requirements are necessary to achieve these theoretical mode energies and surface amplitudes. We begin by creating a one-dimensional moist convective cloud model and find that the available kinetic energy of the rising cloud column falls below theoretical estimates of oscillation energies. That is, mode excitation cannot occur with a single storm eruption. We then explore stochastic excitation scenarios of the oscillations by moist convective storms. We find that mode energies and amplitudes can reach theoretical estimates if the storm energy available to the modes is more than just kinetic. In order for the modes to be excited, we find that they require 5 × 1027 to 1028 erg per day. However, even for a large storm eruption each day, the available kinetic energy from the storms falls two orders of magnitude short of the required driving energy. Although our models may oversimplify the true complexity of the coupling between Jovian storms and global oscillations, our findings reveal that enough thermal energy is associated with moist convection to drive the modes, should it be available to them.

Dynamic modeling method of the bolted joint with uneven distribution of joint surface pressure

The dynamic characteristics of the bolted joints have a significant influence on the dynamic characteristics of the machine tool. Therefore, establishing a reasonable bolted joint dynamics model is helpful to improve the accuracy of machine tool dynamics model. Because the pressure distribution on the joint surface is uneven under the concentrated force of bolts, a dynamic modeling method based on the uneven pressure distribution of the joint surface is presented in this paper to improve the dynamic modeling accuracy of the machine tool. The analytic formulas between the normal, tangential stiffness per unit area and the surface pressure on the joint surface can be deduced based on the Hertz contact theory, and the pressure distribution on the joint surface can be obtained by the finite element software. Futhermore, the normal and tangential stiffness distribution on the joint surface can be obtained by the analytic formula and the pressure distribution on the joint surface, and assigning it into the finite element model of the joint. Qualitatively compared the theoretical mode shapes and the experimental mode shapes, as well as quantitatively compared the theoretical modal frequencies and the experimental modal frequencies. The comparison results show that the relative error between the first four-order theoretical modal frequencies and the first four-order experimental modal frequencies is 0.2% to 4.2%. Besides, the first four-order theoretical mode shapes and the first four-order experimental mode shapes are similar and one-to-one correspondence. Therefore, the validity of the theoretical model is verified. The dynamic modeling method proposed in this paper can provide a theoretical basis for the accurate dynamic modeling of the bolted joint in machine tools.

The Debate with Method in the History of Literary Studies

Abstract Drawing on a number of histories of literary studies from the United States, Britain, and France, this article reexamines the debates on the institutional self-definition of the subject. The ideals associated with research and scholarship, it is argued (following an analysis proposed by Hans Blumenberg), have their historical origin in the concept of method introduced by Descartes, and subsequently central to the natural and the social sciences. This ideal is here argued to represent an unacknowledged line of continuity between the philologists and historical scholars with whom academic literary studies began, the New Critics, and contemporary theoretical modes of literary studies. This article points to the dissidence to this model which appears in each of the national traditions of literary studies. This dissidence, it is argued, has its foundation and its legitimation in the distinction between the subject of reading (and criticism) and the subject of method. While this distinction was made as an objection to the research model, it could not have been articulated prior to the establishment of literary studies as a field of academic research; in this sense, it can be said to be the question that the field itself has posed, and ought to be integrated into its self-understanding.

Coordination of efforts in disaster relief supply chains: the moderating role of resource scarcity and redundancy

ABSTRACTConnecting to the ongoing conversation on the importance of effective coordination, in this paper, we empirically examine the impact of key theoretical modes of coordination, i.e. resource sharing, standardisation of operations, and synchronisation in disaster relief supply chains, on the performance of the humanitarian organisations. Survey data are collected from 101 humanitarian organisations in the emerging countries within Southeast Asia. Data are used to test a conceptually developed model, using structural equation modelling–partial least square (SEM-PLS) approach. The results reveal the significant impact of resource sharing and standardisation on performance outcomes in terms of resources used, responsiveness, and flexibility, while resource sharing is highly weakened by resource scarcity and redundancy. The managerial implication and recommendations are concluded for further research.

High-pressure structural and vibrational properties of monazite-type BiPO4, LaPO4, CePO4, and PrPO4

Monazite-type BiPO4, LaPO4, CePO4, and PrPO4 have been studied under high pressure by ab initio simulations and Raman spectroscopy measurements in the pressure range of stability of the monazite structure. A good agreement between experimental and theoretical Raman-active mode frequencies and pressure coefficients has been found which has allowed us to discuss the nature of the Raman-active modes. Besides, calculations have provided us with information on how the crystal structure is modified by pressure. This information has allowed us to determine the equation of state and the isothermal compressibility tensor of the four studied compounds. In addition, the information obtained on the polyhedral compressibility has been used to explain the anisotropic axial compressibility and the bulk compressibility of monazite phosphates. Finally, we have carried out a systematic discussion on the high-pressure behavior of the four studied phosphates in comparison to results of previous studies.

Anchorage Effect on Flexural Fiber Reinforced Polymer (FRP) Laminate Strengthening of Lightweight Concrete Beams

Anchorage Effect on Flexural Fiber Reinforced Polymer (FRP) Laminate Strengthening of Lightweight Concrete Beams Tariq Aljaafreh, Eyosias Beneberu, Ph.D., P.E; Nur Yazdani, Ph.D., P.E., F.ASCE Abstract Lightweight (LW) concrete is finding increasing use primarily to decrease the dead load, reinforcements needed and member sizes. The beneficial effect of flexural fiber reinforced polymer (FRP) laminates in enhancing the capacity of normal-weight concrete has been well-demonstrated. However, such application on LW has not been explored in depth, especially with confining anchorage systems that can prevent premature debonding of the flexural laminates. This study investigated the effect of utilizing mechanical anchorage and FRP U-wrap anchorage on the performance of LW concrete beams. The carbon FRP laminate enhanced the flexural capacity of all strengthened beams by up to 12%. The CFRP U-wrap was found to be more effective than the mechanical anchorage in delaying the debonding failure of the flexural laminate and increasing its tensile strain by as much as 81%. However, the mechanical anchorage was more effective in increasing the elastic stiffness of the beams. Strengthened beams are likely to have increased durability due to the decreased crack width, length and spacing. The demonstrated failure modes of cover delamination and U-wrap debonding contradicted the theoretical failure mode from the American Concrete Institute (ACI) guidelines. Such guidelines do not currently include the contribution of FRP anchorage systems for concrete structures. Full Text: PDF DOI: 10.15640/jea.v5n2a2

Pole Exercise Causes Body Changes in Physical Flexibility and Exercise Function

Background: Theoretical mode of spinal stability and core stability has been introduced previously, which has proceeded to rehabilitative approaches. We have focused on physical flexibility and exercise function, and firstly devised an original pole exercise in sitting position that can be done simply and cost-effectively.Subjects and Methods: The subjects 11 healthy young adults, 27.0 ± 5.6 years old. Methods included the intervention of pole exercise with Exercise of the thorax, lower thoracic vertebrae and pelvis, upper thoracic vertebrae and pelvis. Before and after the exercise, we investigated examinations. Tests of physical flexibility were Wing Test, Thomas Test, Shoulder Extension Test, straight leg raise (SLR), Body warp prone position, Heel Buttock Distance (HBD) and Finger Floor Distance (FFD). Tests of exercise functions were Back Muscle Strength (BMS), Weight Bearing Index (WBI), Functional Reach Test (FRT) and closed eye leg standing time.Results: The data of 7 flexibility tests and 4 exercise function tests revealed the significant differences between before and after the pole exercise (p<0.05). These tests would cover detail aspects of several human abilities in physiotherapy.Discussion and Conclusion: In current study, pole exercise seems to be clinically simple and easy method to perform. These results suggested that pole exercise including 6 movements would have clinical efficacy as to physical flexibility and exercise function in short period. Currently obtained data could become fundamental data for clinical application and research development in the future.

Photon-excited carriers and emission of graphene in terahertz radiation fields

Graphene exhibits excellent electronic and optical properties, which has been proposed as an advanced material for new generation of electronic and optical devices. We develop a detailed theoretical mode to investigate the optical properties of graphene-wafer systems. The photon-excited carriers and emission are obtained based on the mass-balance equation and the charge number conservation equation, which are derived from Boltzmann equation. The analytical results of photon excited carrier density and photon emission coefficient are achieved self-consistently in terahertz radiation fields. It is found that the photon excited carrier density increases with doped electron density or temperature decreasing. The higher the doped electron density and the lower the temperature, the larger the photon emission coefficient is. The optical emission increases with doped electron density increasing, and the optical emission increases with temperature decreasing. It shows that photon-excited carriers and emission of graphene can be effectively tuned by gate voltage. These theoretical results can be used to understand the relevant experimental findings. This theoretical study can benefit the applications in advanced optoelectronic devices based on graphene, especially terahertz devices.

Thorax Flexibility can be Increased by Standing Pole Exercise

Background: Discussion has been continued about the stability of the spine, and relationship with physical flexibility and exercise function. We have continued physical rehabilitation for various subjects, and proposed clinical application for pole exercise. In this study, we investigated the efficacy of standing pole exercise. Study protocol: The subjects were 9 healthy adults, 26.9 ± 5.9 years old. Method included standing pole exercise and 2 tests before and after the exercise. The exercise has 6 movements, including lateral bending, axis rotation, wave motion, backward spiral, forward spiral and warp and rounding. The pole was 160 cm in length, 610 g in weight. Two tests were percentage vital capacity (%VC) and weight bearing index (WBI), which showed significant differences between before and after the exercise (p<0.01). Discussion and conclusion: Theoretical mode of spinal stability has relationship with inner/outer core stability, flexibility, expandability, curved angles in spinal alignment, and so on. In current study, standing pole exercise would be effective for increased %VC and WBI, which may be from increased flexibility and expandability. These data would be basal data for clinical application and research development in the future.

TE modes of UV-laser generated waveguides in a planar polymer chip of parabolic refractive index profile

The UV-laser lithographic method is used for the preparation of Polymeric integrated-optical waveguides in a planar polymer chip. The waveguide samples are irradiated by an excimer laser of wavelength 248 nm with different doses and with the same fluencies. The refractive index depth profile for the waveguides, in the first zone is found to have a parabolic shape and Gaussian shape in the second one that can be determined by Mach–Zehnder interferometer. Both the mode field distribution and the effective mode indices for the first zone only are determined by making use of the theoretical mode and the experimental data. It is found that the model field distribution is strongly dependent on the refractive indices for each zone.

Influence of health education on the blood sugar management and life quality of aged type 2 diabetic patients based on trans theoretical mode

Objective To explore the influence of health education on the blood sugar management and life quality of aged type 2 diabetic patients based on trans theoretical model. Methods A total of 110 type 2 diabetic patients hospitalized in the endocrinology department of the first affiliated hospital of this school were selected in the range of January to June 2014.The confirmed diagnosis time was ≥12 months, and the age was ≥60 years old.They were divided into control group and observation group (55 cases each). Conventional content and mode were conducted to control group to have health education. Health education was conducted to observation group based on trans theoretical model on the basis of conventional nursing. During the hospital stay, a professional education team was formed to have knowledge-based system training uniformly on trans theoretical model. Within 24 of hospital stay, the specific stage of behaviors was judged to implement the specific health education according to the cognitive characteristics and health need evaluation of patients. It was implemented 20 to 30min per time and 1 to 2 times a week.After discharge, interview was conducted once two weeks.In addition, individualized life guidance was conducted aimed at the specific behavior characteristics in different stages.The metabolic index changes before and after intervention were observed.Moreover, life quality scale was used to evaluate the life quality of patients. Results 6 months after intervention, the BMI, 2 h PBG, FBG, HbA1c, TG and TC levels of observation group were significantly lower than control group.In addition, the scores of life quality were significantly lower than control group.In addition, the level of life quality had more advantages.The between-group difference had statistical significance(P<0.05). Conclusions Based on the trans theoretical model, with regard to the different behavior change stages of the aged diabetes, individualized health education can be implemented to promote patients to change behaviors, keep positive and optimistic mood, strengthen patients' motivation for health, which will be beneficial to control blood sugar and keep metabolism stable.The compliance behaviors and self-care ability can be improved significantly.In addition, life quality can be improved obviously.Meanwhile, it can imperceptibly improve nurse-patient relationship and improve the satisfaction with nursing work, which is worth having further promotion. Key words: Trans theoretical mode; Elderly with type 2 diabetic; Life quality

Effects of Health Education on Cardiovascular System in Middle-aged and Elderly People—Take Aerobic Exercise for Example

Our country has entered the aged society, the health education in the elderly is imminent. The studies in the effects of aerobic exercise mode on the cardiovascular system in the middle-aged and elderly people will provide theoretical basis and practice mode. Research methods: 30 healthy people (aged 50-70) were selected to undertake 8-week exercise as the aerobic exercise model (45mins/day, 5times/week). Measured indexes such as cardiovascular functions, hemodynamics flow, blood fat and renin-angiotensin-aldosterone system (RAAs) before and after the exercise, and then analyzed and compared them by mathematical statistics. Research result: 1) Cardiovascular function indexes pulse rate (PR), pulse pressure(PP), systolic pressure(SP), diastolic pressure(DP), valid pump effort(VPE) of left heart, heart oxygen consumption volume (HOV) decrease more or less, while cardiac output(CO), stroke volume(SV), stroke index(SI), cardiac index(CI) is obviously higher than before (p<0.01). 2) There is no significant difference in hemorrheology indexes like thrombus formation lime (TFL), microcirculation strees time (MST), and erythrocyte aggregation index(VAI), while blood viscosity (ηb), blood reduced viscosity (ηr), fibringen (PFC), plasma viscosity (ηp), hematocrit (Hct) drop apparently (p<0.05). 3) Blood-lipoid indexes cholesterol (Ch), triglyceride (Tg), low density lipoprotein (LDL) gets lower after the experiment, while high density lipoprotein (HDL) is higher (p<0.01). 4) Angiotensin I (Ang I) is obviously lower than that before the experiment, but angiotensin II (Ang II) and aldosterone (Ald) has no significant differences. Research Conclusion: the aerobic exercise model of jogging plus broadcast gymnastics is beneficial for middle-aged and elderly people 1) improve their cardiovascular system function. 2) decrease the blood viscosity with a certain significance to prevent high blood viscosity syndrome (HVS) for them. 3) prevent the coronary atherosclerosis in them. 4) accelerate renal blood flow in them, reduce angiotensin I secretion, improve cardiovascular functions, strengthen cardiovascular compliance, prevent and reverse the risk of cardiovascular disease.

Theoretical Clues and Research Ideas of Major Frontier Issues in Modern Political Economics

This paper focuses on several major theoretical problems of modern political economics, such as negative value of joint production, the law of changes in commodity value, the transformation of values, the law of the decline in average margin, economic long waves, fairness and efficiency, international unequal exchange and virtual economy & value. And based on these issues, along with these key points around new theories of value theory, economic growth and economic cycle, income distribution and international change inequality, the macroeconomic framework of virtual value and its application, it summarizes core views of the challenges and defense on these problems as well as some new thinking and exploration in domestic and foreign academia. As the new theory of value theory is concerned, and based on Steedman interrogation, it raises negative theory in environmental field; in response to the mystery of the century, it explores the law of changes in commodity value under the background of competition and monopoly,heterogeneous goods of the same kind, and joint production; faced with the transformation problem for a century on the basis of one-sided viewpoint, it demonstrates dynamic transformation model. In terms of economic growth and economic cycle, to critique Okishio theorem, it establishes the theoretical mode of a technical and institutional organic composition (TICC); based on the problem of comparison between three long-wave theories, it establishes a long-wave theory according to technology power, system power and coupling power. As for income distribution and international exchange inequality, according to converse phenomenon of income distribution, it demonstrates the theoretical analysis by bringing opportunity inequality into Marxist income distribution theoretical framework; according to the new changes in the unequal international exchange in the three areas of international economy, it builds the international inequality blend theory. As for virtual value and virtual economy, it builds a theoretical model of virtual economy and applies it into areas such as Internet Plus, Bitcoin, and new media.

Spectroscopic investigations (FT-IR, UV, 1H and 13C NMR) and DFT/TD-DFT calculations of potential analgesic drug 2-[2-(dimethylamino)ethyl]-6-methoxy-4-(pyridin-2-yl)-1(2H)-phthalazinone

The theoretical molecular geometry and the IR, UV, 1H and 13C NMR spectroscopic properties of 2-[2-(dimethylamino)ethyl]-6-methoxy-4-(pyridin-2-yl)-1(2H)-phthalazinone with the previously demonstrated in vivo analgesic activity were characterized. The conformational analysis, performed using the molecular mechanics method with the General AMBER Force Field (GAFF) and the Density Functional Theory (DFT) approach with the B3LYP hybrid functional and the 6–31 + g(d) basis sets, allowed to determine the most stable rotamer. The theoretical molecular geometry of this conformer was then calculated at the B3LYP/6–311++g(d,p) level of theory, and its phthalazinone core was compared with the experimental geometry of 1(2H)-phthalazinone. The calculated vibrational frequencies and the potential energy distribution enabled to assign the theoretical vibrational modes to the experimental FT-IR bands. The UV spectrum calculated with the Time-Dependent Density Functional Theory (TD-DFT) method in methanol identified the main electronic transitions and their character. 1H and 13C NMR chemical shifts simulated by the Gauge-Independent Atomic Orbital (GIAO) method in chloroform confirmed the previous assignment of the experimental resonance signals. The stability of the molecule was considered taking into account the hyperconjugation and electron density delocalization effects evaluated by the Natural Bond Orbital (NBO) method. The calculated spatial distribution of molecular electrostatic potential made possible to estimate the regions with nucleophilic and electrophilic properties. The results of the potentiodynamic polarization measurements were also indicated the corrosion inhibition activity of the title compound on 100Cr6 bearing steel in 1 mol dm−3 HCl solution.