Archives-March 2012

In a wireless network, one of the major problem is optimization. Optimization problem is finding the best path from all possible paths. This paper proposes a new architecture called Mixed Layer Design to avoid this problem. Even after providing faster transmission of data we are still facing a problem called throughput in wireless network. This problem is due to the interference of wireless signals. In a wireless network, the signal sent by a terminal will be received by all its neighbouring nodes. If a neighbour (except the destinations) is receiving data from some other terminals at the same time, the signals will collide, and the useful signal will be destroyed, which may result in transmission failure. To solve this problem we are proposing Mixed Signals to avoid the collision of signals. We show that intelligently mixing signals and layers increases network throughput and transmission time.

Ni-Al₂O₃-Cr metal matrix hybrid composite coatings were developed in a conventional Watt electroplating solution, containing suspended nanoparticles of alumina and chromium. The characterization of the composite layer was carried out by scanning electron microscopy (SEM), X-ray diffractometry (XRD) and Energy-dispersive X-ray spectroscopy (EDX) facilities. SEM, XRD and EDX studies showed that a novel hybrid Ni-Al₂O₃-Cr metal matrix composite (MMC) coating formed successfully on a pure copper substrate with about 11.5 % and 4.4 % vol. Al₂O₃ and Cr dispersed nanoparticles respectively. A texture modification and grain refinement were found in composite layers. The incorporation of nanoparticles of Al₂O₃ and Cr changed the preferential nickel growth orientation from (220) to the (200) plane. The SEM studies on the morphology of a Ni- Al₂O₃-Cr composite surface illustrated that the nickel column growth slowed down in the composite film and the composite coating had a more condensed and smoother surface compared to pure nickel coatings. The mean grain sizes of the pure nickel and composite coats were determined as 103 and 19 nm respectively. The SEM micrographs showed that the nano particles were uniformly dispersed in the electrodeposited nano-structured Ni matrix and the alumina particles agglomerated in sizes of above 100 nm. The micro-hardness and wear resistance test results showed a remarkable improvement in the mechanical properties of the electroplated nickel by creating a nano composite structure of Ni-Al₂O₃-Cr.

Identifying the occurrence of congestion in a Mobile Ad-hoc Network (MANET) is a major task. The inbuilt congestion control techniques of existing Transmission Control Protocol (TCP) designed for wired networks do not handle the unique properties of shared wireless multi-hop link. There are several approaches proposed for detecting and overcoming the congestion in the mobile ad-hoc network. In this paper we present a Modified AD-hoc Transmission Control Protocol (M-ADTCP) method where the receiver detects the probable current network status and transmits this information to the sender as feedback. The sender behavior is altered appropriately. The proposed technique is also compatible with standard TCP.

The solid transportation problem (STP) arises when bounds are given on three item properties. The fuzzy solid transportation problem (FSTP) appears when the nature of the data problem is fuzzy. This paper deals with the robust fuzzy solid transportation problem based on extension principle under uncertain demands. The fuzzy solid transportation problem is transformed into a pair of mathematical programs that is employed to calculate the lower and upper bounds of the fuzzy total transportation cost at possibility level . In this paper, we are interested in a robust version of location fuzzy transportation problem with an uncertain demand using a 2-stage formulation: one with inequality constraints and the other with equality constraints.

Reliable accelerator operation requires control system with higher level of automation, flexibility, robustness, and optimisation. In this paper a multi-agent system based control scheme is presented for optimal control of accelerator system that improves the plant performance in wide-range of operations. The multi-agent based control schemes for accelerators have been reported in literature. But the scheme proposed in this paper differs significantly form the existing schemes. In this work the agent architecture is formulated based on the control requirements of pre-injector accelerator subsystem (Microtron in particular) and transport line of synchrotron radiation sources. The scheme consists of two software agents at supervisory level that work in an autonomous manner for the optimized control of dynamic system. The Microtron agent architecture augments model assisted adaptive controller for realizing feedback control action at lower layer and goal based logic controller with pre-structure model identifier along with the pattern recognizer at supervisory layer. The TL-1 agent has a model-based, goal-based modular architecture and optimizes the TL-1 control using differential evolution based algorithm. The simulation results of applying this scheme to model of Microtron and Transport Line-1 of INDUS complex shows that this approach is very effective in optimizing the Microtron and TL-1 tuning.

The present paper deals with estimation of the population mean of the study variable when the information on the auxiliary variable is known and their population parameters are known. In the past, a number of modified ratio estimators are suggested with known values for the Co-efficient of Variation, Co-efficient of Kurtosis, Co-efficient of Skewness, Population Correlation Coefficient etc. However all these modified ratio estimators are biased but with less mean squared errors compared to the usual ratio estimator. In this paper some strategies have been suggested to improve the performance of the existing modified ratio estimators, which lead to a class of almost unbiased modified ratio estimators; and their performances are better than the modified ratio estimators. These are explained with the help of numerical examples.

The experiment was conducted to evaluate the effect of vermicompost and urea on the growth and yield of the vegetable plant, Hibiscus esculentus.  Hibiscus esculentus is allowed to grew in the medium of vermicompost and urea. Three were 3 treatment viz., control, vermicompost (T1)and urea (T2). Observation was made from 10 randomly selected plants per pot. The effect of the organic fertilizer (vermicompost) and inorganic fertilizer (urea) on the growth and yield of the Hibiscus esculentus were studied. The germination percentage, shoot length and yield of the plant were recorded on 20^th, 40^th and 60^th days. The present study revealed that vermicompost seems to be maintained the soil which is ideal for growth of the plant. The highest yield of Hibiscus esculentus  was found in vermicompost treatment (T-1) followed by urea (T-2) and lowest in control. Application of vermicompost increased the vegetative growth and yield of Hibiscus  esculentus.

FT-IR and FT-Raman spectra of 2-amino-4-pyrimidinol (2A4P) have been recorded. The spectra were interpreted with the aid of normal coordinate analysis following full structure optimizations and force field calculations based on density functional theory (DFT) using standard B3LYP/6-311+G** method. Normal coordinate calculations were performed with the DFT force field corrected by a recommended set of scaling factors yielding fairly good agreement between observed and calculated frequencies. Further, density functional theory (DFT) combined with quantum chemical calculations to determine the first-order hyperpolarizability.

Faith in Arabic means 'aqada,ya’qidu, ‘aqdun or ‘uqdah. Generally faith implies strong ties or knots. This knot is tying and usually in the form of bonds associated with maknawi or hissi, where this maknawi bond is stronger than hissi because it can expand by humans. Among the words that are often associated with ‘Aqada’ (maknawi), in sale and purchase (aqada al-Bay’), which means the bond purchase. Apart from that, it also associates with such an agreement (‘aqada al-‘Ahd), which bonds the agreement. The Quran frequently uses the word with the purpose of bonding.

Increased environmental awareness and strictness in emissions regulations have led to development of Warm Mix Asphalt (WMA). The potential of WMA in reducing the energy consumption as compared to Hot Mix Asphalt (HMA) is becoming more and more attractive nowadays. The goals for the WMA are to lower the mixing and compacting temperatures by reducing the viscosity of the binder, and using the same HMA plants to produce mixes that still meet specifications. The benefits of WMA include reduced emissions, decreased energy (fuel) consumption, reduced asphalt oxidation and early traffic opening. Several technologies of WMA are available today such as Aspha-min, Sasobit, Evotherm, WMA-Foam and Asphaltan B. Viscosity of the binder is used to determine its mixing, laying and compaction temperatures.In the present study Brookfield Viscometer is used for determination of the viscosity of bituminous binders with different combinations of additives at different temperatures ranging from 90ºC to 160ºC. Two binders VG 30 and CRMB 55, and two additives Sasobit and Evotherm are used. The results shows that the viscosity of the bituminous binders varies exponentially with the temperature and linearly with respect to the dose of Warm Mix additives and the mixing temperature can be reduced by 20ºC to 25ºC while laying and compaction temperature can be reduced by 10ºC to 15ºC by using these additives.