Preparation And Characterization Of Water-Soluble Chitosan Gel For Skin Hydration.

Kitosan, biopoliaminosakarida secara linear dan semulajadi, telah mendapat banyak perhatian sebagai bio-polimer berfungsi dengan aplikasi dalam bidang farmaseutikal, makanan, kosmetik dan perubatan. Chitosan, a natural and linear biopolyaminosaccharide, has received much attention as a functional biopolymer with applications in pharmaceuticals, food, cosmetics and medicines. Nevertheless, chitosan application is limited by its solubility in aqueous solution

Analytical approach of late-time evolution in a torsion cosmology

In this letter, we study the late-time evolution of a torsion cosmology only with the spin-$0^+$ mode. We find three kinds of analytical solutions with a constant affine scalar curvature. In the first case, it is not physical because the matter density will be negative. In the second case, it shows that the dark energy can be mimicked in the torsion cosmological model. In the third case, the characteristic of late-time evolution is similar to that of the universe of matter dominant. And we also find a kind of expression with the non-constant curvature that the periodic character of numerical calculation is only the reflection of solution in a specific period of evolution. Using these expressions, we shall be able to predict the evolution over the late-time. From this prediction, we know the fate of universe that the universe would expand forever, slowly asymtotically to a halt.Comment: 12pages,6 figure

Poincar\'e Gauge Theory With Coupled Even And Odd Parity Dynamic Spin-0 Modes: Dynamic Equations For Isotropic Bianchi Cosmologies

We are investigating the dynamics of a new Poincar\'e gauge theory of gravity model, which has cross coupling between the spin-0$^+$ and spin-0$^-$ modes. To this end we here consider a very appropriate situation---homogeneous-isotropic cosmologies---which is relatively simple, and yet all the modes have non-trivial dynamics which reveals physically interesting and possibly observable results. More specifically we consider manifestly isotropic Bianchi class A cosmologies; for this case we find an effective Lagrangian and Hamiltonian for the dynamical system. The Lagrange equations for these models lead to a set of first order equations that are compatible with those found for the FLRW models and provide a foundation for further investigations. Typical numerical evolution of these equations shows the expected effects of the cross parity coupling.Comment: 13 pages, 2 figure

Disease universe: Visualisation of population-wide disease-wide associations

We apply a force-directed spring embedding graph layout approach to electronic health records in order to visualise population-wide associations between human disorders as presented in an individual biological organism. The introduced visualisation is implemented on the basis of the Google maps platform and can be found at http://disease-map.net . We argue that the suggested method of visualisation can both validate already known specifics of associations between disorders and identify novel never noticed association patterns.Comment: 4 pages (2 pics) the main paper + 8 pages (3 pics) Supplementary Material

The phonon thermal Hall angle in black phosphorus

The origin of phonon thermal Hall Effect (THE) observed in a variety of insulators is yet to be identified. Here, we report on the observation of a thermal Hall conductivity in a non-magnetic elemental insulator, with an amplitude exceeding what has been previously observed. In black phosphorus (BP), the longitudinal ($\kappa_{ii}$), and the transverse, $\kappa_{ij}$, thermal conductivities peak at the same temperature and at this peak temperature, the $\kappa_{ij}/\kappa_{jj}/B$ is $\approx 10^{-4}$-$10^{-3}$ T$^{-1}$. Both these features are shared by other insulators displaying THE, despite an absolute amplitude spreading over three orders of magnitude. The absence of correlation between the thermal Hall angle and the phonon mean-free-path imposes a severe constraint for theoretical scenarios of THE. We show that in BP a longitudinal and a transverse acoustic phonon mode anti-cross, facilitating wave-like transport across modes and the anisotropic charge distribution surrounding atomic bonds, paving the way for coupling with magnetic field.Comment: 4 figures and 7 pages. The supplementary materials were attached to the en

Threshold of photoelectron emission from CNx films deposited at room temperature and at 500 °C

The threshold of photoelectron emission was measured for amorphous CNx films deposited at room temperature (RT) and at 500 °C. The x values of the films deposited at RT and at 500 °C by magnetron sputtering of a graphite target in a mixed N2/Ar gas were 0.6 and 0.3, respectively. Ratios of the sp2- to sp3-hybridized components of both C and N for the film deposited at 500 °C were larger by 4 times than those for the film deposited at RT. The onsets of the electron emission by photon irradiation were 5.0 and 4.7 eV for the films deposited at RT and at 500 °C, respectively

Fuzzy Environment Mapping for Robot Navigation Based on Grid Computing

In order to navigate autonomously, a mobile robot needs to build an environment map where the robot is navigating. Currently, the sensors are mounted on the robot to detect if the obstacles exist and then the map immediate surrounding of the robot is built to help for navigation path planning. The map created by this method is a local map that may cause global navigation problem which a global coverage map is needed to solve such a problem. In this study, a sensor network is deployed for building global environment map. All the sensor locations are assumed known. The navigation space is divided into grids and a grid is to be detected if obstacles exist by one or a number of sensors. Fuzzy set concept is used to introduce a tool useful for sensor perception. Those sensors work as a team to explore all the space and then the global fuzzy map is constructed. The experiments show that the fuzzy map is more practical and helps the path planning problem to be solved more efficiently

Semi-Data-Aided Channel Estimation for MIMO Systems via Reinforcement Learning

Data-aided channel estimation is a promising solution to improve channel estimation accuracy by exploiting data symbols as pilot signals for updating an initial channel estimate. In this paper, we propose a semi-data-aided channel estimator for multiple-input multiple-output communication systems. Our strategy is to leverage reinforcement learning (RL) for selecting reliable detected symbols among the symbols in the first part of transmitted data block. This strategy facilitates an update of the channel estimate before the end of data block transmission and therefore achieves a significant reduction in communication latency compared to conventional data-aided channel estimation approaches. Towards this end, we first define a Markov decision process (MDP) which sequentially decides whether to use each detected symbol as an additional pilot signal. We then develop an RL algorithm to efficiently find the best policy of the MDP based on a Monte Carlo tree search approach. In this algorithm, we exploit the a-posteriori probability for approximating both the optimal future actions and the corresponding state transitions of the MDP and derive a closed-form expression for the best policy. Simulation results demonstrate that the proposed channel estimator effectively mitigates both channel estimation error and detection performance loss caused by insufficient pilot signals

Towards harmonious East-West educational partnerships: a study of cultural differences between Taiwanese and Norwegian engineering students

The collaboration activities between educational institutions in the East and the West are on the increase as an increasingly globalized economy requires graduates to have the skills to work across cultural divides. Such collaborations are difficult and require patience. One challenge is that students or teachers may have misconceptions about aspects of the other culture that may cause problems. This study sets out to identify what values students in typical Eastern and Western societies associate with a good student, good student behavior, good teachers and good lectures with the purpose to identify discrepancies. This study is based on the results of a pair-wise ranking questionnaire completed by 233 Taiwanese and Norwegian students of both engineering and non-technical subjects. The results confirm some established beliefs regarding culturally related differences. However, several issues were found to be culturally neutral, and cultural differences were identified for several issues that were predicted to be culturally neutral. The results of this study may be useful to educators involved in East–West internationalization