Structured Peer-to-Peer Real Time Video Transmission over Vehicular Ad Hoc Networks

Video communication over Vehicular Ad Hoc Networks (VANET) has several applications such as road safety, commercial advertisements and on-road entertainment. In this paper we present a structured peer-to-peer (P2P) network designed for the distribution of live-content, with low bandwidth consumption, within a VANET. This P2P network is modelled using a media distribution graph. The implementation of a structured network allows a peer to schedule consecutive data chunks produced by the media source by means of a scheduling algorithm. In our analysis we obtain a bound for the maximum delay between the media source and any of the peers of the network and the buffer size needed to allow consecutive scheduling. We study a type of media distribution graph and we calculate its order and diameter, which means that under stable conditions we can ensure certain quality-of-service parameters. The results of simulation over NS2 show the fitness of the mathematical analysis.     

The effect of Nd:YAG laser irradiation on root surface: shear-bond strength and SEM–EDX study

To investigate the effects of Nd:YAG laser and 17% EDTA treatment on root-dentin mineral content using scanning electron microscope–energy dispersive X-ray spectroscopy (SEM–EDX) and on shear-bond strength of epoxy-resin-based sealer (AH Plus) to root dentin. Twelve extracted premolars were decoronated and roots were sectioned, so that 24 two-root halves were obtained. Element levels of each half were examined by SEM/EDX, and AH Plus build-ups were created. After shear-testing, the test surfaces were reground and subjected to a 5.25% NaOCl. Two subgroups were created according to the surface treatment (n = 12): G1, with 17% EDTA for 5 min; G2, with the Nd:YAG laser. The element level analysis and shear-bond strength test were repeated for each half; the data were recorded (MPa) and analyzed (paired samples t-test). The EDTA treatment increased the O, C, Ca/P ratio (p < 0.001), decreased Ca, P content (p = 0.000), but did not change Na, Mg content (p > 0.05). The Nd:YAG laser increased O, Ca/P ratio (p < 0.001), and decreased the Ca, P content (p = 0.000). The C, Mg, Na content did not change with the Nd:YAG laser (p > 0.05). Both 17% EDTA and Nd:YAG laser had an effect on the mineral content of roots. The 17% EDTA treatment decreased the shear-bond strength of AH Plus to root dentin (p = 0.000); however, the Nd:YAG laser did not affect the bond strength (p = 0.238). Thus, an Nd:YAG laser can be used for disinfection of the root canal when AH Plus is used as a sealer.     

Experimental investigation of passive/active oxidation behavior of SiC based ceramic thermal protection materials exposed to high enthalpy plasma

The passive/active oxidation behavior of a CVD-SiC coated C/C-SiC thermal protection material of the hypersonic SpaceLiner vehicle is investigated experimentally. For the safety of spacecraft and its passengers, it is important to know whether the thermal protection system will experience passive/active oxidation during the vehicle's entry into Earth's atmosphere. Active oxidation can promote material loss whereas passive oxidation forms a protective film.The high enthalpy flight conditions of SpaceLiner vehicle are duplicated in VKI Plasmatron, where the samples are exposed to high enthalpy plasma and the surface temperatures increase up to 2800 K at various total pressure (2–20 kPa) conditions. Surface temperature profiles, visual characteristics, mass changes, emissivity, spectrometer and SEM/EDX data are examined to identify the oxidation transition border of the tested material. A temperature jump is observed in all active oxidation regimes. The experimental results are found to be in good agreement with correlations from the literature.     

The effect of hydrogen on the electronic,mechanical and phonon properties of LaMgNi4 and its hydrides for hydrogen storage applications

Density functional theory calculations are used herein to explore the effect of hydrogen on the electronic, mechanical and phonon properties of LaMgNi₄ and its hydrides. The polycrystalline elastic moduli, Poisson's ratios and Debye temperatures are calculated based on the single-crystal elastic constants and Voigt-Reuss-Hill approximations. It is also found that all these materials are metallic behavior, ductile and anisotropic in nature. The mechanical anisotropy is discussed via several anisotropy indices and three-dimensional (3D) surface constructions. The effect of high temperature on the free energy, entropy, and heat capacity are also studied by using the quasi-harmonic Debye model. LaMgNi₄ and its hydrides are found to be energetically, mechanically and dynamically stable. Also, they are thermodynamically stable and the order of phase stability is LaMgNi₄H₇ > LaMgNi₄H₄ > LaMgNi₄H > LaMgNi₄. In addition, the highest gravimetric hydrogen storage capacity is found to be 1.74 wt% for LaMgNi4H₇.     

避难城 贝尔谢巴市贝丝哈罗契姆

正灰色贝尔谢巴,一个即使在寒冬也极度干燥、尘土飞扬的城市。贝尔谢巴向干涸的河床缓缓移动,沿着河床,另一头便是沙漠。当地的标准建筑一般采用灰色的清水混凝土,与城市的黄色尘土相呼应。大学、市政厅、索罗卡医院和"内格夫中心"都位于城市主干道上,全部由清水混凝土建造。在贝尔谢巴西边,能看到交叉路口上的战斗机;在贝尔谢巴南边,能看到一辆远离战场的装甲车。贝尔谢巴就位于战斗机和装甲车中间。在两年前的"铸铅行动"中,这里曾遭遇多番"格拉德"型导弹袭击。内格夫旅十字路口位于城市东北方向的入口处,     

Water Deficiency and Induced Defense Against a Generalist Insect Herbivore in Desert and Mediterranean Populations of Eruca sativa

In natural and agricultural ecosystems, plants are often simultaneously or sequentially exposed to combinations of stressors. Here we tested whether limited water availability (LWA) affects plant response to insect herbivory using two populations of Eruca sativa from desert and Mediterranean habitats that differ in their induced defenses. Considering that such differences evolved as responses to biotic and possibly abiotic stress factors, the two populations offered an opportunity to study ecological aspects in plant response to combined stresses. Analysis of chemical defense mechanisms showed that LWA significantly induced total glucosinolate concentrations in the Mediterranean plants, but their concentrations were reduced in the desert plants. However, LWA, with and without subsequent jasmonate elicitation, significantly induced the expression of proteinase inhibitor in the desert plants. Results of a no-choice feeding experiment showed that LWA significantly increased desert plant resistance to Spodoptera littoralis larvae, whereas it did not affect the relatively strong basal resistance of the Mediterranean plants. LWA and subsequent jasmonate elicitation increased resistance against the generalist insect in Mediterranean plants, possibly due to both increased proteinase inhibitor expression and glucosinolate accumulation. The effect of LWA on the expression of genes involved in phytohormone signaling, abscisic acid (ABA-1) and jasmonic acid (AOC1), and the jasmonate responsive PDF1.2, suggested the involvement of abscisic acid in the regulation of defense mechanisms in the two populations. Our results indicate that specific genotypic responses should be considered when estimating general patterns in plant response to herbivory under water deficiency conditions.

     

Magnetic Resonance Temperature Mapping of Microwave-Fried Chicken Fingers

ABSTRACT:  The main objective of this study was to compare the heating patterns of chicken fingers deep-fried conventionally and using a microwave. Two dimensional internal temperature maps of fried chicken fingers with rectangular geometry were measured post frying using magnetic resonance imaging (MRI). Frying was performed in a microwave oven at 365 W power level for 0.5 and 1.5 min after bringing the oil temperature to 180 ± 1 °C. Samples were also fried in a conventional fryer at 180 °C for 2 and 5 min for comparison. Variations in internal temperature distribution increased proportionally to frying time in both microwave and conventional frying. Internal thermal equilibrium is reached in all samples after 13 min of holding time. Internal structural changes, void formation, were also visualized in the images. Void formation did not significantly impact cooling rates.     

Acrylamide formation in different batter formulations during microwave frying

Acrylamide, a probable human carcinogen, is found to be formed in a wide range of fried foods. In this study, the effects of microwave frying on acrylamide formation in the coating part of chicken were investigated. It was also aimed to determine the effects of various flour types (soy, chickpea and rice flour) in batter formulations on the acrylamide formation and on the color of fried chicken. Usage of all flour types except soy flour resulted in approximately the same moisture content and color development after 1.5 min of microwave frying. Acrylamide contents of batter parts of 1.5 min microwave fried samples having different flours were similar. Microwave frying provided lower acrylamide content and lighter color as compared to those fried conventionally for 5 min for all types of flours. This reduction in acrylamide level was the highest (34.5%) for rice flour containing batter.     

Oral administration of liposomal insulin

There have been several attempts published in the literature related with orally effective insulin formulations, which are increasing in popularity. Some of the results indicate that it is possible to reduce blood glucose level by orally administered liposomal insulin formulations, but there is general need to understand the mechanism and effective components of the liposome formulations. In our study, liposomal insulin formulations were prepared using insulin (Humulin R) or protamine- containing insulin (Humulin N) with cholesterol, dipalmitoyl phosphatidylcholine (egg) (DPPC)-cholesterol mixture, and mucoadhesive agent (methyl cellulose, MC)-added DPPC-cholesterol mixture. A tablet formulation of insulin was also prepared. Formulations of liposomal insulin were introduced to mice and rats orally and reduced blood glucose levels were observed. The composition of phospholipid (DPPC, cholesterol and MC mixture) was found to be quite effective in reducing blood glucose levels. The pH of the solution and the presence of the protamine sulfate were found to be important. The application site was also found to be important because liposomal insulin formulations administered through the mouth or esophagus resulted in reduced blood glucose levels. Reduced blood glucose levels were also observed when tablet formulations of insulin were administered to rats orally.