Linear-nonlinear stiffness responses of carbon fiber-reinforced polymer composite materials and structures: a numerical study

The stiffness response or load-deformation/displacement behavior is the most important mechanical behavior that frequently being utilized for validation of the mathematical-physical models representing the mechanical behavior of solid objects in numerical method, compared to actual experimental data. This numerical study aims to investigate the linear-nonlinear stiffness behavior of carbon fiber-reinforced polymer (CFRP) composites at material and structural levels, and its dependency to the sets of individual/group elastic and damage model parameters. In this regard, a validated constitutive damage model, elastic-damage properties as reference data, and simulation process, that account for elastic, yielding, and damage evolution, are considered in the finite element model development process. The linear-nonlinear stiffness responses of four cases are examined, including a unidirectional CFRP composite laminate (material level) under tensile load, and also three multidirectional composite structures under flexural loads. The result indicated a direct dependency of the stiffness response at the material level to the elastic properties. However, the stiffness behavior of the composite structures depends both on the structural configuration, geometry, lay-ups as well as the mechanical properties of the CFRP composite. The value of maximum reaction force and displacement of the composite structures, as well as the nonlinear response of the structures are highly dependent not only to the mechanical properties, but also to the geometry and the configuration of the structures

In vivo antimalarial assessment and toxicity evaluation of garlic (Allium sativum) in plasmodium berghei NK65-induced mice

Garlic or Allium sativum is widely applied as alternative medicine and in ethnopharmacological studies. This study was done to evaluate the antimalarial properties of aqueous extract of garlic against Plasmodium berghei NK65. The groups of male ICR mice were intraperitoneally (i.p) infected with 0.1 mL of 1 × 107 parasitised red blood cells (RBC) before being orally given pre- and post-infection treatments with 0.2 mL of 100 mg/kg body weight (bw) of freeze-dried aqueous garlic extract. Parasitemia was microscopically examined and measured by Giemsa stained thin blood smear. There was a positive correlation (p<0.05, n = 6) for all assessed parameters; parasitemia density (%), survival time (day) and the ability to inhibit the parasite growth (%) between pre-treated infected mice with the other groups. However, the value recorded was still lower compared to the mice treated with commercial antimalarial drug primaquine and chloroquine. However, biochemical parameters of treated animals were in the normal range indicative of no toxicity. Histological examination showed no abnormalities and injuries on the selected vital organs. This study proved garlic has potential as alternative antimalarial dru

Space Animated with Three Dimensional Studio Max Edy

Animation is a collection of images shown alternately so it looks to move. A collection of pictures from the picture is the frame. Frame is needed in animation applications. Number of frames per-second animation affect the smoothness of movement. Animation of this space is one example of modeling a very simple animation. To create this animation writers using 3D Studio Max as the software. 3D Studio Max is very easy to use and has many facilities and other securities. This animation hopefully useful application for users of computers, especially in the field of multimedia

Stress Tensor from the Trace Anomaly in Reissner-Nordstrom Spacetimes

The effective action associated with the trace anomaly provides a general algorithm for approximating the expectation value of the stress tensor of conformal matter fields in arbitrary curved spacetimes. In static, spherically symmetric spacetimes, the algorithm involves solving a fourth order linear differential equation in the radial coordinate r for the two scalar auxiliary fields appearing in the anomaly action, and its corresponding stress tensor. By appropriate choice of the homogeneous solutions of the auxiliary field equations, we show that it is possible to obtain finite stress tensors on all Reissner-Nordstrom event horizons, including the extreme Q=M case. We compare these finite results to previous analytic approximation methods, which yield invariably an infinite stress-energy on charged black hole horizons, as well as with detailed numerical calculations that indicate the contrary. The approximation scheme based on the auxiliary field effective action reproduces all physically allowed behaviors of the quantum stress tensor, in a variety of quantum states, for fields of any spin, in the vicinity of the entire family (0 le Q le M) of RN horizons.Comment: 43 pages, 12 figure

Magnetic nanoparticles as efficient bulk pinning centers in type-II superconductors

Enhancement of flux pinning by magnetic nanoparticles embedded into the bulk of type-2 superconductor is studied both theoretically and experimentally. Magnetic part of the pinning force associated with the interaction between a spherical magnetic inclusion and an Abrikosov vortex was calculated in the London approximation. Calculations are supported by the experimental results obtained on sonochemically modified MgB2 superconductor with embedded magnetic Fe2O3 nanoparticles and compared to MgB2 with nonmagnetic Mo2O5 pinning centers of similar concentration and particle size distribution. It is shown that ferromagnetic nanoparticles result in a considerable enhancement of vortex pinning in large-kappa type-2 superconductors.Comment: PDF, 14 page

Langevin Thermostat for Rigid Body Dynamics

We present a new method for isothermal rigid body simulations using the quaternion representation and Langevin dynamics. It can be combined with the traditional Langevin or gradient (Brownian) dynamics for the translational degrees of freedom to correctly sample the NVT distribution in a simulation of rigid molecules. We propose simple, quasi-symplectic second-order numerical integrators and test their performance on the TIP4P model of water. We also investigate the optimal choice of thermostat parameters.Comment: 15 pages, 13 figures, 1 tabl

The Main Reasons for the Revival of Islam in Independent Kazakhstan

In the modern world history, we notice such phenomena as; globalization, digitalization, value pluralism, mass migration, terrorism, post-secularity, etc., which characterize the current nature of human civilization. Recently, among these trends, the phenomenon of the “revival of Islam” has emerged. Therefore, the systematic discussion relating to the phenomenon of Islam in the socio-cultural processes of the society has prevalent in religious studies. This topic has gained considerable attention by Kazakh researchers have also paid attention to this topic. The society of Kazakhstan has closely related to Islam in aspects of culture, history, personality, and morality. Since the collapse of the United Socialist Soviet Republics (USSR), Kazakhstan has gradually been becoming one of the fastest growing countries in Central Asia, focusing on modernization processes. Even though it follows secular nature of constitution, it has not only allowed the reentrance of traditional religious presence, but scholars have also noticed features of religious revival. Purpose of the article analyze the main factors that activated the mass- revival of Islam within the Kazakh society after the country's independence. Leading methods − conceptual analysis, structural analysis, and comparative analysis. Thanks to a systematic generalization of domestic and foreign researchers’ views, as well as sociological data, it became possible to form common knowledge about the causes of the revival of Islam in Kazakhstan

Quasiparticle Heat Transport in Ba1−x_{1-x}Kx_xFe2_2As2_2: Evidence for a k-dependent Superconducting Gap without Nodes

The thermal conductivity $\kappa$ of the iron-arsenide superconductor Ba$_{1-x}$K$_x$Fe$_2$As$_2$ ($T_c \simeq$ 30 K) was measured in single crystals at temperatures down to $T \simeq 50$ mK ($\simeq T_c$/600) and in magnetic fields up to $H = 15$ T ($\simeq H_{c2}$/4). A negligible residual linear term in $\kappa/T$ as $T \to 0$ shows that there are no zero-energy quasiparticles in the superconducting state. This rules out the existence of line and in-plane point nodes in the superconducting gap, imposing strong constraints on the symmetry of the order parameter. It excludes d-wave symmetry, drawing a clear distinction between these superconductors and the high-$T_c$ cuprates. However, the fact that a magnetic field much smaller than $H_{c2}$ can induce a residual linear term indicates that the gap must be very small on part of the Fermi surface, whether from strong anisotropy or band dependence, or both