A pre-emptive multiple queue based congestion control for different traffic classes in WSN

Traffic in wireless sensor networks (WSN) exhibits a many-to-one pattern in which multiple source nodes send sensing data to a single sink node. Since bandwidth, processor and memory are highly constrained in WSN, packet loss is common when a great deal of traffic rushes to sink. The system must provide differentiated service to individual traffic classes. In this paper, a pre-emptive multiple queue based congestion control mechanism is proposed. To detect congestion and to provide QoS for high priority traffic multiple buffers are used. Using this mechanism, high system utilization, reduced packet waiting time, and reduced packet drop probability are achieved. An analytical model is developed to predict the performance of the proposed mechanism by calculating the performance measures including system throughput, drop probability of packets, and mean queue length. By comparing analytical and simulation results the effectiveness and accuracy of the model is demonstrated. Markovian process is used to develop the analytical model and ns-2 for evaluating the performance of the mechanism

Evaluation of serum copper and iron levels among oral submucous fibrosis patients

Objective: To estimate and compare the levels of serum copper and iron among subjects with oral submucous fibrosis (OSMF) of different clinical stages and healthy controls. Study Design: Study sample comprised of 50 patients clinically diagnosed with OSMF and 50 healthy controls who were matched for age and gender. OSMF patients were categorised by clinical staging. Serum estimation of copper and iron was done using atomic absorbtion spectrophotometry. Results: Mean copper and iron level differed significantly (p<0.000) between the patients and controls with patients exhibiting higher copper (134.1±20.16) and lower iron (114.78±23.47) levels in contrast to controls who presented lower copper (114.8±12.36) and higher iron (130.86±31.01) levels in serum. There was a definite trend as (P<0.0001) with cases having the lesion in faucial bands (1st stage) exhibiting the lowest serum copper and those in stage 3 (faucial, labial and buccal bands) presenting the highest copper levels in serum. Conclusions: Copper level increased and iron level decreased in study group in comparison to healthy controls. Copper level increased as clinical stage of oral submucous fibrosis increased. © Medicina Oral S. L

Synthesis of single crystalline (NH4)2V6O16·1.5H2O nest-like structures

Novel nest-like (NH4)2V6O16·1.5H2O structures made of nanobelts have been synthesized by a facile hydrothermal approach. The powder X-ray diffraction pattern of the sample reveals the monoclinic crystalline phase of (NH4)2V6O16·1.5H2O. The scanning electron microscopy images of the sample obtained at 130 °C for 3 days exhibit nest-like morphology. The transmission electron microscopy result reveals that the nanobelts have a smooth surface. The selected area electron diffraction pattern of the nanobelts indicates single crystalline nature. The two major weight losses occur in thermogravimetric analysis which correspond to the removal of water and ammonia molecules. Further, calcination of the (NH4)2V6O16·1.5H2O product results in the formation of orthorhombic phase of shcherbianite V2O5

Parametric vis-a-vis non parametric measures describing G x E interactions for salt salinity tolerant barley genotypes in multi-environment trials

GxE interaction to know adaptability of 19 salt salinity tolerant barley genotypes was studied by parametric and non-parametric measures. Genotypes KB1516, RD2907 and RD2794 showed minimum environmental variance over different environments. Superiority index identified genotypes RD2907 and NDB1445 with lowest value accompanied with higher. Wricke’s measure exhibited lower values of DWRB168,&nbsp; DWRB165 and NDB1445. Higher values of GAI showed consistent performance of RD2907, NDB1445 and RD2552. Non-parametric measures Si(1), Si(3) and Si(6) the considered DWRB165 and DWRB168&nbsp; as desirable genotypes. Thennarasu’s first measure NPi(1) found DWRB168 and NDB1445 as desirable adaptable and KB1546, RD2907 and NDB1173 were unstable genotypes. Wricke’s parameter was positively correlated with NPi(1), NPi(3) and Kang. GAI had significant positive with Pi and Kang while negative with Si(6), NPi(2) &amp; NPi(4). Worth to mention the negative association of&nbsp; Pi with Si(6), NPi(2), NPi(4). Non parametric measures Si (3) Si (6) NPi (2) &amp; NPi (4) clubbed together while Kang, Wi 2, s2i ,Si (1),Si (2) ,NPi (1) &amp; NPi (3)&nbsp; joined in another cluster.&nbsp; Left over parametric measures were grouped in two separate clusters i.e. (bi, S2xi ,CVi),(Yield, GAI Pi) respectively.&nbsp; Biplot analysis based on first two principal components showed three groups among the measures

Double exchange model on triangular lattice: non-coplanar spin configuration and phase transition near quarter filling

Unconventional anomalous Hall effect in frustrated pyrochlore oxides is originated from spin chirality of non-coplanar localized spins, which can also be induced by the competition between ferromagnetic (FM) double exchange interaction $J_{H}$ and antiferromagnetic superexchange interaction $J_{AF}$. Here truncated polynomial expansion method and Monte Carlo simulation are adopted to investigate the above model on two-dimensional triangular lattice. We discuss the influence of the range of FM-type spin-spin correlation and strong electron-spin correlation on the truncation error of spin-spin correlation near quarter filling. Two peaks of the probability distribution of spin-spin correlation in non-coplanar spin configuration clearly show that non-coplanar spin configuration is an intermediate phase between FM and 120-degree spin phase. Near quarter filling, there is a phase transition from FM into non-coplanar and further into 120-degree spin phase when $J_{AF}$ continually increases. Finally the effect of temperature on magnetic structure is discussed.Comment: 10 pages, 5 figure

Some Bianchi Type III String Cosmological Models with Bulk Viscosity

We investigate the integrability of cosmic strings in Bianchi III space-time in presence of a bulk viscous fluid by applying a new technique. The behaviour of the model is reduced to the solution of a single second order nonlinear differential equation. We show that this equation admits an infinite family of solutions. Some physical consequences from these results are also discussed.Comment: 12 pages, no figure. To appear in Int. J. Theor. Phy

A New Class of Inhomogeneous String Cosmological Models in General Relativity

A new class of solutions of Einstein field equations has been investigated for inhomogeneous cylindrically symmetric space-time with string source. To get the deterministic solution, it has been assumed that the expansion ($\theta$) in the model is proportional to the eigen value $\sigma^{1}_{1}$ of the shear tensor $\sigma^{i}_{j}$. Certain physical and geometric properties of the models are also discussed.Comment: 12 pages, no figure. Submitted to Astrophys. Space Sci. arXiv admin note: substantial text overlap with arXiv:0705.090

Bulk Viscous LRS Biachi-I Universe with variable GG and decaying Λ\Lambda

The present study deals with spatially homogeneous and totally anisotropic locally rotationally symmetric (LRS) Bianchi type I cosmological model with variable $G$ and $\Lambda$ in presence of imperfect fluid. To get the deterministic model of Universe, we assume that the expansion $(\theta)$ in the model is proportional to shear $(\sigma)$. This condition leads to $A=\ell B^{n}$, where $A$,\;$B$ are metric potential. The cosmological constant $\Lambda$ is found to be decreasing function of time and it approaches a small positive value at late time which is supported by recent Supernovae Ia (SN Ia) observations. Also it is evident that the distance modulus curve of derived model matches with observations perfectly.Comment: 11 pages, 4 figures and 1 table, Accepted for publication in Astrophysics and Space Scienc

Soliton Squeezing in a Mach-Zehnder Fiber Interferometer

A new scheme for generating amplitude squeezed light by means of soliton self-phase modulation is experimentally demonstrated. By injecting 180-fs pulses into an equivalent Mach-Zehnder fiber interferometer, a maximum noise reduction of $4.4 \pm 0.3$ dB is obtained ($6.3 \pm 0.6$ dB when corrected for losses). The dependence of noise reduction on the interferometer splitting ratio and fiber length is studied in detail.Comment: 5 pages, 4 figure

Modulation Instability of Ultrashort Pulses in Quadratic Nonlinear Media beyond the Slowly Varying Envelope Approximation

We report a modulational instability (MI) analysis of a mathematical model appropriate for ultrashort pulses in cascaded quadratic-cubic nonlinear media beyond the so-called slowly varying envelope approximation. Theoretically predicted MI properties are found to be in good agreement with numerical simulation. The study shows the possibility of controlling the generation of MI and formation of solitons in a cascaded quadratic-cubic media in the few cycle regimes. We also find that stable propagation of soliton-like few-cycle pulses in the medium is subject to the fulfilment of the modulation instability criteria