Effects of Biaxial Crystal Field on the Magnetic Properties on?a?Spin-1?Ising?System

Within the effective field theory (EFT) with a probability distribution technique that accounts for the self spin correlation functions, the magnetic properties such as the hysteresis loops, susceptibility and magnetization of a spin-1 Ising system with effects of a biaxial crystal field are studied. The effects of the biaxial crystal field on the magnetic properties are discussed and numerical calculations are performed and analyzed for the cases of the honeycomb lattice. A number of interesting phenomena such as the shape of the hysteresis loops and the susceptibility have been found.     

Investigation of chemical keys for relationship between plants and their unifloral honeys by hydrodistillation and SPME and biological activities of honeys

Volatile compounds of unifloral honeys and their plants essential oils obtained by hydrodistillation (EOH) and solid phase micro extraction (EOS) methods were investigated and compared with each other for the first time. The results exhibited presence of volatile compounds of plant such as o-cymene and carvacrol in Thymus, cis-linalool oxide in Citrus, aliphatic hydrocarbons in Citrus and Astragalus and hexadecanoic acid (palmitic acid) in Astragalus and Medicago honeys. The amounts of terpenes were decreased by increasing molecular weight in EOS, while this pattern does not occur in EOH. Total phenols and antioxidant activities were increased from Citrus to Thymus honey (Citrus < Medicago < Astragalus < Thymus). In antibacterial assay, Thymus honey showed the most potential inhibition to all the experimented strains of bacteria. Increase in phenol content may be an effective factor for antibacterial activity of honey against Escherichia coli, Staphylococcus aureus and Bacillus subtilis. It seems that active compounds with antioxidant properties were responsible for growth inhibition effect on E. coli and S. aureus.     

Petrological control on engineering properties of carbonate rocks in arid regions

Bulletin of Engineering Geology and the Environment - Petrological features of carbonate rocks that exert control on their mechanical and physical properties are examined in the study presented...     

Solid-state cooling line based on the electrocaloric effect

In this paper, the feasibility of using ferroelectric materials as a cooling device or solid-state refrigerator based on the electrocaloric effect has been considered. The electrocaloric responses of two different ferroelectric capacitors (PMN-25PT, PZN-4.5PT) are studied. In this study, the dynamics of temperature variation at the edges of a layered structure comprised of an electrocaloric material with heatconducting elements on its sides to an applied periodic electric field have been studied. Electrocaloric elements can generate directed heat flux as a thermal pump by alternative switching. A temperature reduction of 6° is obtained in an electric field of 1 KV/mm at a frequency of 1 Hz for PMN-25PT material after applying 80 cycles. It is shown that the type of applied electric pulses and ferroelectric material affect the results.     

Far Infrared Investigation of Plasmon-LO Phonon Coupling and Surface Polaritons Modes in Donor Doped Cd1-xHgxTe and CdTe Thin Layer on GaAs Substrate

Infrared Fourier transform spectroscopy has been used to investigate phonon and plasmon modes in Cd_1-xHg_xTe and CdTe thin layer on GaAs substrate. Attenuated total reflection (ATR) spectroscopy has been used to excite surface plasmon and phonon polaritons. The plasmon-LO phonon coupling modes in samples are studied by dispersion curve calculation for various carrier concentrations. There exist three branches of coupled modes in dispersion curve. For analysis of the far infrared polarized reflectivity spectra we employ the harmonic oscillator dielectiic function model and the Drude model for free carrier response. We find that the coupling modes dependent to the concentration of free carriers. Furthermore, the experimental data have been used to calculate carrier concentration, composition parameter, mobility of carrier, thickness of layer and gap energy.     

Effects of prenatal exposure to diesel exhaust particles on postnatal development, behavior, genotoxicity and inflammation in mice

Background

Results from epidemiological studies indicate that particulate air pollution constitutes a hazard for human health. Recent studies suggest that diesel exhaust possesses endocrine activity and therefore may affect reproductive outcome. This study in mice aimed to investigate whether exposure to diesel exhaust particles (DEP; NIST 2975) would affect gestation, postnatal development, activity, learning and memory, and biomarkers of transplacental toxicity. Pregnant mice (C57BL/6; BomTac) were exposed to 19 mg/m³ DEP (~1·10⁶ particles/cm³; mass median diameter ? 240 nm) on gestational days 9–19, for 1 h/day.

Results

Gestational parameters were similar in control and diesel groups. Shortly after birth, body weights of DEP offspring were slightly lower than in controls. This difference increased during lactation, so by weaning the DEP exposed offspring weighed significantly less than the control progeny. Only slight effects of exposure were observed on cognitive function in female DEP offspring and on biomarkers of exposure to particles or genotoxic substances.

Conclusion

In utero exposure to DEP decreased weight gain during lactation. Cognitive function and levels of biomarkers of exposure to particles or to genotoxic substances were generally similar in exposed and control offspring. The particle size and chemical composition of the DEP and differences in exposure methods (fresh, whole exhaust versus aged, resuspended DEP) may play a significant role on the biological effects observed in this compared to other studies.     

Identification and analysis of hydrostatic transmission system

The dynamic behavior of hydro-static transmission (HST) systems is studied experimentally and theoretically to formulate a linearized mathematical model of the HST system and a recursive identification model is then proposed. A computer-controlled test rig is developed and the system state responses are measured. The results obtained from the experimental work and the linearized models are used to build a recursive identification model in order to identify the system under study. Furthermore, comparisons among the experimental, simulated, and identified results are presented. These results show that recursive identification models are powerful tools that can be used for the identification and analysis of HST. Finally, parameter variations of the volume displacement and the motor torque are introduced to the system in order to study their effect on pressure and hydraulic motor speed.     

Multi-facility location problems in the presence of a probabilistic line barrier: a mixed integer quadratic programming model

We consider a multi-facility location problem in the presence of a line barrier with the starting point of the barrier uniformly distributed. The objective is to locate n new facilities among m existing facilities minimising the summation of the weighted expected rectilinear barrier distances of the locations of new facilities and new and existing facilities. The proposed problem is designed as a mixed-integer nonlinear programming model, conveniently transformed into a mixed-integer quadratic programming model. The computational results show that the LINGO 9.0 software package is effective in solving problems with small sizes. For large problems, we propose two meta-heuristic algorithms, namely the genetic algorithm and the imperialist competitive algorithm for optimisation. The numerical investigations illustrate the effectiveness of the proposed algorithms.     

High aspect ratio gold nanorods displayed augmented cellular internalization and surface chemistry mediated cytotoxicity

Due to their unique properties, gold nanorods (GNRs) have shown tremendous potential for advancing bio-imaging and sensing applications. As these nanoparticles display size-dependent optical properties, high aspect ratio GNRs are of particular interest for these applications because of their increased scattering contrast. While studies are emerging that demonstrate successful synthesis of high aspect ratio GNRs, their behavior and fate in a physiological environment has yet to be investigated. The goal of this study was to evaluate the rate of cellular internalization and cytotoxicity of long GNRs (aspect ratio 32) in a human keratinocyte cell line. Additionally, the critical role of surface chemistry in extent of cellular interactions and cytotoxicity was evaluated. Through comparison with aspect ratio 3 GNRs, it was identified that high aspect ratio GNRs displayed enhanced cellular internalization. Furthermore, surface functionalization dictated the quantity of GNRs internalized, with tannic acid having a significant increase over polyethylene glycol. However, the augmented intracellular concentration identified with long, tannic acid GNRs resulted in a considerable degree of cytotoxicity, which was not associated with other GNR conditions. Therefore, while the inclusion of high aspect ratio GNRs may increase the capabilities for nano-based applications, there exist some unintentional toxicological consequences that must also be considered.