2,540 research outputs found
A new creep model directly using tabulated test data and implemented in ansys
Nowadays plastics are increasingly used in highly stressed structures in all kinds of constructions. The time dependency, the so-called viscosity, is a crucial part of the material behavior of plastics. A typical form of viscosity is creep. Creep is the increase of deformation under constant load. In the FE-simulation creep behavior is usually described by creep law functions. The commercial software provide many creep law functions depending on time, stress, strain, temperature and multiple material parameters. To run a creep simulation, the user must define all the parameters which requires a certain effort. Curve-fitting procedures might be of help, the results, however, often are not precise enough. For these reasons, we introduce our new creep model doing the similar job as the creep law functions but being able to directly use the tabulated data of the creep tests without curve-fitting procedures. In this paper, we use the model to create a 3D stress-creep strain-time surface based on the tabulated data like isochronous curves, which is represented by bicubically blended Coons patches to provide a good convergence due to their differentiability. This creep model supports strain hardening, which shows more realistic behavior when the load changes significantly during the simulated proces
Microfluidics for simultaneous quantification of platelet adhesion and blood viscosity
Platelet functions, including adhesion, activation, and aggregation have an influence on thrombosis and the progression of atherosclerosis. In the present study, a new microfluidic-based method is proposed to estimate platelet adhesion and blood viscosity simultaneously. Blood sample flows into an H-shaped microfluidic device with a peristaltic pump. Since platelet aggregation may be initiated by the compression of rotors inside the peristaltic pump, platelet aggregates may adhere to the H-shaped channel. Through correlation mapping, which visualizes decorrelation of the streaming blood flow, the area of adhered platelets (A(Platelet)) can be estimated without labeling platelets. The platelet function is estimated by determining the representative index I-A.T based on A(Platelet) and contact time. Blood viscosity is measured by monitoring the flow conditions in the one side channel of the H-shaped device. Based on the relation between interfacial width (W) and pressure ratio of sample flows to the reference, blood sample viscosity (mu) can be estimated by measuring W. Biophysical parameters (IA.T, mu) are compared for normal and diabetic rats using an ex vivo extracorporeal model. This microfluidic-based method can be used for evaluating variations in the platelet adhesion and blood viscosity of animal models with cardiovascular diseases under ex vivo conditions.119Ysciescopu
The Device for the Treatment of Diabetes with Use of Infrared Radiation and Porous TiNi Based Alloy
The research addresses the problem of design and development of a new needle-free method for diabetes treatment. New porous-permeable TiNi-based materials and new methods of IR-radiation effect on tissues of the body have been used in the research. The properties of porous alloys are similar to those of high-capacity materials that can hold a large volume of insulin solution in the porous structure of the material. With this, IR-radiation stimulates directed diffusion of insulin from the porous TiNi structure to the tissues of the body. This makes the basis for development of a needle-free device for diabetes treatment. The proposed technique does not cause skin irritation, and it is safe when used in practice. The efficiency of insulin delivery was evaluated in clinical studies. The results showed the potential of prolonged delivery for both insulin and other liquids
Electronic structures of LaS and CeS
We have investigated electronic structures of LaS and CeS
using the LSDA and LSDA+ methods. Calculated density of states (DOS) are
compared with the experimental DOS obtained by the valence band photoemission
spectroscopy. The DOS at indicates the 5 character in
LaS and 4 character in CeS. It is found to be nearly half
metallic in the ferromagnetic ground state of CeS. %CeS has
ferromagnetic ground states with spin and orbital magnetic %moments of 1.27
and 2.81 per Ce, respectively, %and shows
nearly half metallic ground state. We discuss the superconductivity and
structural transition in LaS, and the absence of structural transition
in CeS.Comment: Transport and Thermal Properties of Advanced Materials(Aug. 2002;
Hiroshima, Japan
Correction to: Does transcranial direct current stimulation improve functional locomotion in people with Parkinson’s disease? A systematic review and meta-analysis
In the original article [1], we mentioned that some study characteristics of the article by Dagan and colleagues [2] were unavailable. However, we realized that the authors provided the relevant information in their supplementary file. As such, we added participant characteristics (i.e., age = 68.8 ± 6.8, gender = 17 M, 3 F, PD duration = 9.0 ± 5.7, and UPDRS Part III at baseline = Total 39.7 ± 14.6) to Table 1, stimulation parameters (i.e., intensity = 3 mA, duration = 20 min, areas = 3 cm2) to Table 2, and methodological quality assessments (i.e., allocation concealment = 1 and Total score = 9) to Table 3. Based on the new information, we updated Fig. 2 with the corrected selection bias and performance bias results. Finally, we confirmed that these corrections did not change the meta-analytic findings in the original article
Cholesterol granuloma in the wall of a mandibular dentigerous cyst: a rare case report
Cholesterol granuloma is an inflammatory reaction to cholesterol crystals deposition. It may develop in a variety of
sites including the middle ear, mastoid process or even paranasal sinuses. Very few cases of cholesterol granuloma
occurring in the jaws were reported. This report presents a rare case of cholesterol granuloma that developed in
the wall of a large mandibular dentigerous cyst. The condition was treated with hemimandibulectomy followed by
reconstruction with a free fibular flap
Design and Realization of Multiplexing System for Fixed/Mobile Next-Generation Broadcasting Service in Network Free Environment
The Current broadcasting enviroment is constally evolving in order to meet the various needs of the viewer such as ColorTV, 3D, HD, UHD TV serivce. And they want to broadcasting the same quality in the fixed and mobile enviroment for high definition braodcasting serive. In this paper, we presnet a design and implementation of muilplexing system for fixed/mobile next generation broadcasting service in network free enivorment. Network free means receive both the broadcasting channel and communication chennel for various TV service. We introduce method to provide next generation convergence broadcating servies based on european standard which can transmit UHD content in network free envieroment. As a result to this paper, we analyze the characteristics of the recieved signal from the commerical receiver device
Shutdown of an offshore wind power plant without using a brake to meet the required ramp rate in various storm-driven conditions
This paper proposes an offshore WPP (wind power plant) shutdown algorithm that does not use a braking system and meets the required ramp rate in the grid code in various storm-driven conditions. The proposed algorithm determines the number of WGs (wind generators) to shut down simultaneously to achieve this requirement without using brakes. Based on the storm speed and direction measured at a WM (wind mast) installed several kilometers away from the WPP, the storm-arrival time from the WM to each WG is calculated. Then, an arrival-ordered sequence is generated for the WGs based on these storm-arrival times. The WGs are grouped in a predetermined number to shut down simultaneously. The shutdown start- and end-times of the WGs are determined by considering the storm-arrival time and the shutdown duration time. The algorithm re-calculates the storm-arrival times and the shutdown start- and end-times of the WGs if the storm speed and/or direction change. The various test results demonstrate that the algorithm successfully shuts down the WPP without using a brake by meeting the required ramp rate even when the storm speed and direction change
One-Loop QCD Mass Effects in the Production of Polarized Bottom and Top Quarks
The analytic expressions for the production cross sections of polarized
bottom and top quarks in annihilation are explicitly derived at the
one-loop order of strong interactions. Chirality-violating mass effects will
reduce the longitudinal spin polarization for the light quark pairs by an
amount of , when one properly considers the massless limit for the final
quarks. Numerical estimates of longitudinal spin polarization effects in the
processes and are presented.Comment: 17 p. (5 figs available upon request), LaTeX, MZ-TH/93-30, RAL/93-81,
FTUV/93-4
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