New Enhance Approach Based on RC4 for the Grid Security

No Abstrac

Effect of mo, nb and v on hot deformation behaviour, microstructure and hardness of microalloyed steels

Three novel low carbon microalloyed steels with various additions of Mo, Nb and V were investigated after thermomechanical processing simulations designed to obtain ferrite-bainite microstructure. With the increase in microalloying element additions from the High V-to NbV-to MoNbV-microalloyed steel, the high temperature flow stresses increased. The MoNbV and NbV steels have shown a slightly higher non-recrystallization temperature (1000°C) than the High V steel (975°C) due to the solute drag from Nb and Mo atoms and austenite precipitation of Nb-rich particles. The ambient temperature microstructures of all steels consisted predominantly of polygonal ferrite with a small amount of granular bainite. Precipitation of Nb-and Mo-containing carbonitrides (\u3e20 nm size) was observed in the MoNbV and NbV steels, whereas only coarser (~40 nm) iron carbides were present in the High V steel. Finer grain size and larger granular bainite fraction resulted in a higher hardness of MoNbV steel (293 HV) compared to the NbV (265 HV) and High V (285 HV) steels

The Role of MgO Modifier on Physical, Structural, Optical andThermoluminescence Properties of Lithium Borate Glass System

Synthesis of lithium borate glass system was carried using the melt quenching technique with varying concentrations ofmagnesium followed by analysing the different characteristics such as physical, structural, optical and thermoluminesceneusing various techniques eg. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Visspectroscopy, and Thermoluminescence (TL). The obtained XRD pattern confirmed the amorphous nature of the preparedsamples. Relevant physical parameters have been evaluated to study the response of these properties with respect tomagnesium content. The density and molar volume values showed that the network structure changed with increasingmagnesium content. It is evident from the FTIR spectra that the network of the prepared samples predominantly containsBO3 and BO4 units. The UV-vis spectra confirmed a decrease in the direct and indirect band gap values with increase inMgO content. Optical parameters namely refractive index, electronic polarizability, reflection loss and dielectric constantwere also calculated and found to be in good correlation with other studies. Following gamma rays irradiation with differentdoses, TL glow curves of prepared glasses were analysed. Deconvolution of TL glow curves was done using glow curveconvolution deconvolution (GCCD) function and trapping parameters of isolated peaks viz. activation energy and frequencyfactor have been determined

Simrank: Rapid and sensitive general-purpose k-mer search tool

Terabyte-scale collections of string-encoded data are expected from consortia efforts such as the Human Microbiome Project (http://nihroadmap.nih.gov/hmp). Intra- and inter-project data similarity searches are enabled by rapid k-mer matching strategies. Software applications for sequence database partitioning, guide tree estimation, molecular classification and alignment acceleration have benefited from embedded k-mer searches as sub-routines. However, a rapid, general-purpose, open-source, flexible, stand-alone k-mer tool has not been available. Here we present a stand-alone utility, Simrank, which allows users to rapidly identify database strings the most similar to query strings. Performance testing of Simrank and related tools against DNA, RNA, protein and human-languages found Simrank 10X to 928X faster depending on the dataset. Simrank provides molecular ecologists with a high-throughput, open source choice for comparing large sequence sets to find similarity

Foregut microbiome in development of esophageal adenocarcinoma

Esophageal adenocarcinoma (EA), the type of cancer linked to heartburn due to gastroesophageal reflux diseases (GERD), has increased six fold in the past 30 years. This cannot currently be explained by the usual environmental or by host genetic factors. EA is the end result of a sequence of GERD-related diseases, preceded by reflux esophagitis (RE) and Barrett’s esophagus (BE). Preliminary studies by Pei and colleagues at NYU on elderly male veterans identified two types of microbiotas in the esophagus. Patients who carry the type II microbiota are >15 fold likely to have esophagitis and BE than those harboring the type I microbiota. In a small scale study, we also found that 3 of 3 cases of EA harbored the type II biota. The findings have opened a new approach to understanding the recent surge in the incidence of EA. 

Our long-term goal is to identify the cause of GERD sequence. The hypothesis to be tested is that changes in the foregut microbiome are associated with EA and its precursors, RE and BE in GERD sequence. We will conduct a case control study to demonstrate the microbiome disease association in every stage of GERD sequence, as well as analyze the trend in changes in the microbiome along disease progression toward EA, by two specific aims. Aim 1 is to conduct a comprehensive population survey of the foregut microbiome and demonstrate its association with GERD sequence. Furthermore, spatial relationship between the esophageal microbiota and upstream (mouth) and downstream (stomach) foregut microbiotas as well as temporal stability of the microbiome-disease association will also be examined. Aim 2 is to define the distal esophageal metagenome and demonstrate its association with GERD sequence. Detailed analyses will include pathway-disease and gene-disease associations. Archaea, fungi and viruses, if identified, also will be correlated with the diseases. A significant association between the foregut microbiome and GERD sequence, if demonstrated, will be the first step for eventually testing whether an abnormal microbiome is required for the development of the sequence of phenotypic changes toward EA. If EA and its precursors represent a microecological disease, treating the cause of GERD might become possible, for example, by normalizing the microbiota through use of antibiotics, probiotics, or prebiotics. Causative therapy of GERD could prevent its progression and reverse the current trend of increasing incidence of EA

Media access protocols for cable modems

Cable modems offer qualitatively better performance than either dial-up modems or basic rate ISDN terminal adapters. The cable TV network employs coaxial cable in which the downstream consumes most of the bandwidth from 54 MHz up to the maximum frequency from 600 to 1000 MHz. The upstream is typically assigned to the range from 5 to 42 MHz. One drawback of cable modems is the lack of standards permitting any cable modem to work with any headend equipment. Work toward a multimedia cable network system (MCNS) specification was initiated by Cablelabs, a consortium of Time Warner, Comcast, Cox and Continental Cablevision. This specification defines the physical layer, media access control (MAC) layer, and operational support capabilities. In this thesis, MAC protocols are described for the upstream path of the hybrid fiber coax network system. These are Frequency Division Multiple Access (FDMA), and Slotted ALOHA which are standard methods, and Dynamic Reservation without Contention (DRNC), Dynamic Reservation with Contention (DRC), Dynamic Reservation with Limited Contention (DRLC), and Modified Dynamic Reservation with Limited Contention (M-DRLC) which are proposed in this work. Detailed mathematical analysis is done and throughput and performance are compared for all six MAC protocols when the users of the network have a variety of data rates. Simulations are done to corroborate the analysis, and simulation results are presented. The effect of network delay on the performance is also analysed. Other phenomena, such as white noise and impulse noise also affect the performance. Simulations are presented to examine the effects of noise on the cable system performance. From the analysis and simulation results, it is found that FDMA is a very inefficient protocol and it wastes lots of bandwidth. Slotted ALOHA is a simple way to allocate bandwidth, but it is efficient only at very low channel traffic. DRNC gives higher frame delay because it wastes bandwidth by polling inactive users. DRLC is efficient only at very high channel traffic. DRC is efficient if the number of users is very large and user traffic is bursty. M-DRLC is a combination of the DRC and DRLC protocols and it gives low frame delay even at high channel traffic. Ingress is a big problem in HFC network systems. Even narrowband ingress can make more than 15% of the upstream spectrum useless. Large round trip delay also degrades the cable system performance. Most of the errors generated by white noise and impulse noise can be controlled by using forward error correcting codes. It was found that system performance does not degrade substantially at 10-4 random bit error rate