Modeling anisotropic and rate-dependent plasticity in short-fiber reinforced thermoplastics

In this study, an anisotropic viscoelastic-viscoplastic macro-mechanical model is presented for short-fiber reinforced thermoplastics (SFRT). In injection molding of SFRT, the fiber orientation is influenced by the flow velocity profile which varies throughout the mold. The flow-induced orientation in the microstructure leads to anisotropy in the mechanical response. In addition to the mechanical anisotropy, SFRTs show time dependent behavior because of the thermoplastic matrix. The developed model captures the effects of both material orientation and loading rate on the yield behavior. In this study, uniaxial tests are performed at different strain rates and material orientations with samplescutfrominjectionmoldedplaques. Theexperimentalresultsshowthattheeffects of loading rate and material orientation on the yield are decoupled. The presented model takes advantage of this observation to simplify material characterization. An implicit integration scheme is used for the numerical implementation of the model as a UMAT in ABAQUS. Multiple relaxation times are used in order to capture the nonlinear pre-yield regime. An efficient method for obtaining the model parameters for different modes is proposed. Experimental results are used for validation of the model and a good agreement is observed for the prediction of viscoelastic and viscoplastic behavior

Interacting Cosmic Fluids in Brans-Dicke Cosmology

We provide a detailed description for power-law scaling FRW cosmological models in Brans-Dicke theory dominated by two interacting fluid components during the expansion of the universe.Comment: 13 pages, 8 figure

An integrated microring circuit design for optoelectronic transformer applications

The on-chip scale circuit of the optoelectronic transformer is designed and manipulated using the microring resonator system. By using the monochromatic input light source, the electro-optic signals can be generated and functioned as the step up and down conversion by mean of the on-chip optoelectronic transformer. The step up and down of the electro-optic related power conversions can be obtained via the input and drop port connections. The results obtained have shown that the flexible up and down electro-optic conversion ratios of 1: 5 and 10:1 for the step up and down conversions, respectively. The uses light source wavelength source was centered at 800 nm, where the conversion stability of 1600 fs is noted. The linearity trend of the conversion stability is confirmed

Correlation between length-weight and age in Barbus sharpeyi and Barbus grypus broodstocks in artificial propagation

This study was carried out to identify proper broodstock of Barbus sharpeyi and Barbus grypus using working fecundity indices. For Barbus sharpeyi three female groups were chosen based on previous experiences that included treatment 1: 650±300g, 1±0.5 years, (T.L) 40.68±2.7cm, treatment 2: 1350±350g, 2.5±0.5 years, (T.L) 47.92±4.63cm and treatment 3: 2200±400g, 4±0.4 years, and (T.L) 59.62±3.56cm. The same male broodstock (700±80g) and 2 year old fish were used for all treatments. For Barbus grypus three female groups were chosen using previous experiences that included treatment 1: 2212.5±780g, 2.5±0.5 years, (T.L) 62.68±6.7cm, treatment 2: 4518±780g, 4±1 years (T.L) 79.12±4.36cm and treatment 3: 7712.5±171g, 7.7±1.3 years and (T.L) 92.62±3.13cm. The same male broodstock (1400±100g) and 2 year old fish were used for all treatments. Female broodstock of the two species were injected 3mg/kg of PG hormone two times at an interval of 10 hours and males were injected 2mg/kg. The maximum working fecundity was seen in treatment 2 for Barbus sharpeyi (33000±1450) and Barbus grypus and (13000.37±4651.57). Functional fecundity were calculated for Barbus sharpeyi in all treatments which was significantly different between treatment 2 and other treatments for the two species. After this stage, the working fecundity was decreased in treatments. We conclude that treatment 2 is the best for selection of broodstocks in the two fish species

Microring resonator made by ion-exchange technique for detecting the CO2, H2O, and NaCl as cladding layer

A system of Microring Resonator (MRR) based the comb-like sensor devices has been simulated. We present a Silicon-On-Insulator (SOI) ring resonator based on refractive index sensor. The novelty of the architecture lies in the capability to sense the shifts of multiple peaks simultaneously with an MRR waveguide. The behavior of optical MRRs, especially when functioning as refractive index sensors, is studied. Resonant wavelength, i.e. the wavelength at which the transmission spectrum exhibits a dip (peak) depends on the geometrical characteristics of the circular waveguide and the effective refractive index of the propagating mode. The previous studies have shown that the depth and vertical symmetry of buried waveguides are noticeably affected by the field perturbation. One of cost effective and low loss methods can be the technology known as ion-exchange which uses the glass substrates and the AgNO3/NaNO3 salt-melt at different temperatures and duration can be deposited on the glass substrates. Afterward, an MRR was designed on the glass substrates, where the effect of the carbon dioxide (CO2), Dihydrogen oxide (H2O), and sodium chloride (NaCl) as the cladding on the ion-exchange waveguide studied. Within the compare of the resonance in drop port and throughput port, it can understand that they roughly have the same distance of wavelength in the resonance. H2O is one of the materials showing higher Qfactor and FSR while it was in drop port also in throughput CO2 was the highest in these parameters. Keywords: Microring Resonator (MRR), Sensor, Ion-exchang

Variations of the McEliece Cryptosystem

Two variations of the McEliece cryptosystem are presented. The first one is based on a relaxation of the column permutation in the classical McEliece scrambling process. This is done in such a way that the Hamming weight of the error, added in the encryption process, can be controlled so that efficient decryption remains possible. The second variation is based on the use of spatially coupled moderate-density parity-check codes as secret codes. These codes are known for their excellent error-correction performance and allow for a relatively low key size in the cryptosystem. For both variants the security with respect to known attacks is discussed

Involvement of Inflammatory Cytokines in Antiarrhythmic Effects of Clofibrate in Ouabain-Induced Arrhythmia in Isolated Rat Atria

Considering the cardioprotective and anti-inflammatory properties of clofibrate, the aim of the present experiment was to investigate the involvement of local and systemic inflammatory cytokines in possible antiarrhythmic effects of clofibrate in ouabain-induced arrhythmia in rats. Rats were orally treated with clofibrate (300 mg/kg), and ouabain (0.56 mg/kg) was administered to animals intraperitoneally. After induction of anesthesia, the atria were isolated and the onset of arrhythmia and asystole was recorded. The levels of inflammatory cytokines in atria were also measured. Clofibrate significantly postponed the onset of arrhythmia and asystole when compared to control group (P � 0.05 and P � 0.01, resp.). While ouabain significantly increased the atrial beating rate in control group (P � 0.05), same treatment did not show similar effect in clofibrate-treated group (P > 0.05). Injection of ouabain significantly increased the atrial and systemic levels of all studied inflammatory cytokines (P � 0.05). Pretreatment with clofibrate could attenuate the ouabain-induced elevation of IL-6 and TNF-α in atria (P � 0.01 and P � 0.05, resp.), as well as ouabain-induced increase in IL-6 in plasma (P � 0.05). Based on our findings, clofibrate may possess antiarrhythmic properties through mitigating the local and systemic inflammatory factors including IL-6 and TNF-α. Copyright © 2016 Somayeh Moradi et al

Multi-stage shrinking core model for thermal decomposition reactions with a self-inhibiting nature

Among the variety of thermal decomposition reactions, some display self-inhibiting behaviour, where the produced gas negatively influences the reaction progress. Further, a build-up of internal pressure caused by the product gas may alter the reaction pathway over the reaction duration in a way that favours a particular pathway over others. Two well-known cases of this kind of reaction are the thermal decomposition of limestone and gibbsite, in which carbon dioxide and water vapour are the produced gases, respectively. A multi-stage, multi-reaction, shrinking core model is proposed for this type of reaction. The model emphasises the role of the produced gas, not only in the mass transfer rate, but also in the reaction kinetics. It also includes parallel and series reaction pathways, which allows for the presence of an intermediate species. The model has been applied to the conversion of gibbsite to alumina, and it includes the formation of boehmite as an intermediate product. The model results are in good agreement with experimental data for gibbsite calcination reported in the literature. Gibbsite conversion, boehmite formation and subsequent consumption, as well as alumina formation, are successfully simulated. Further, the corresponding kinetic parameters are estimated for all reactions of interest

Modelling of gibbsite calcination in a fluidized bed reactor

A steady state, non‐isothermal fluidized bed reactor model for co‐current flow of gas and solids has been developed as a series of Continuous Stirred Tank Reactor (CSTR) compartments. For each CSTR compartment, mass and energy balances were coupled with a particle‐scale gibbsite calcination kinetic model previously developed by the authors. The overall solids residence time distribution is captured by the compartment calcination model. The multi‐scale model was solved numerically through an iterative procedure that alternated between solving particle‐scale and reactor‐scale parts of the model. Gas, water vapour and solids concentrations, as well as particle and gas temperatures and gibbsite conversion profiles, are predicted inside the calcination reactor. The developed model can be used to facilitate improvements in the operation and design of industrial‐scale reactors