Total cross-section at LHC from minijets and soft gluon resummation in the infrared region

A model for total cross-sections incorporating QCD jet cross-sections and soft gluon resummation is described and compared with present data on pp and pp cross-sections. Predictions for LHC are presented for different parameter sets. It is shown that they differ according to the small x-behaviour of available parton density functions.

Nonlinear ensemble prediction of chaotic daily rainfall

The significance of treating rainfall as a chaotic system instead of a stochastic system for a better understanding of the underlying dynamics has been taken up by various studies recently. However, an important limitation of all these approaches is the dependence on a single method for identifying the chaotic nature and the parameters involved. Many of these approaches aim at only analyzing the chaotic nature and not its prediction. In the present study, an attempt is made to identify chaos using various techniques and prediction is also done by generating ensembles in order to quantify the uncertainty involved. Daily rainfall data of three regions with contrasting characteristics (mainly in the spatial area covered), Malaprabha, Mahanadi and All-India for the period 1955-2000 are used for the study. Auto-correlation and mutual information methods are used to determine the delay time for the phase space reconstruction. Optimum embedding dimension is determined using correlation dimension, false nearest neighbour algorithm and also nonlinear prediction methods. The low embedding dimensions obtained from these methods indicate the existence of low dimensional chaos in the three rainfall series. Correlation dimension method is done on th phase randomized and first derivative of the data series to check whether the saturation of the dimension is due to the inherent linear correlation structure or due to low dimensional dynamics. Positive Lyapunov exponents obtained prove the exponential divergence of the trajectories and hence the unpredictability. Surrogate data test is also done to further confirm the nonlinear structure of the rainfall series. A range of plausible parameters is used for generating an ensemble of predictions of rainfall for each year separately for the period 1996-2000 using the data till the preceding year. For analyzing the sensitiveness to initial conditions, predictions are done from two different months in a year viz., from the beginning of January and June. The reasonably good predictions obtained indicate the efficiency of the nonlinear prediction method for predicting the rainfall series. Also, the rank probability skill score and the rank histograms show that the ensembles generated are reliable with a good spread and skill. A comparison of results of the three regions indicates that although they are chaotic in nature, the spatial averaging over a large area can increase the dimension and improve the predictability, thus destroying the chaotic nature. (C) 2010 Elsevier Ltd. All rights reserved.

Robust heuristics for scalable optimization of complex SQL queries

Modern database systems incorporate a query optimizer to identify the most efficient "query execution plan" for executing the declarative SQL queries submitted by users. A dynamic-programming-based approach is used to exhaustively enumerate the combinatorially large search space of plan alternatives and, using a cost model, to identify the optimal choice. While dynamic programming (DP) works very well for moderately complex queries with up to around a dozen base relations, it usually fails to scale beyond this stage due to its inherent exponential space and time complexity. Therefore, DP becomes practically infeasible for complex queries with a large number of base relations, such as those found in current decision-support and enterprise management applications. To address the above problem, a variety of approaches have been proposed in the literature. Some completely jettison the DP approach and resort to alternative techniques such as randomized algorithms, whereas others have retained DP by using heuristics to prune the search space to computationally manageable levels. In the latter class, a well-known strategy is "iterative dynamic programming" (IDP) wherein DP is employed bottom-up until it hits its feasibility limit, and then iteratively restarted with a significantly reduced subset of the execution plans currently under consideration. The experimental evaluation of IDP indicated that by appropriate choice of algorithmic parameters, it was possible to almost always obtain "good" (within a factor of twice of the optimal) plans, and in the few remaining cases, mostly "acceptable" (within an order of magnitude of the optimal) plans, and rarely, a "bad" plan. While IDP is certainly an innovative and powerful approach, we have found that there are a variety of common query frameworks wherein it can fail to consistently produce good plans, let alone the optimal choice. This is especially so when star or clique components are present, increasing the complexity of th- e join graphs. Worse, this shortcoming is exacerbated when the number of relations participating in the query is scaled upwards.

Energetics of carbohydrate binding by a 14 kDa S-type mammalian lectin

The thermodynamics of the binding of derivatives of galactose and lactose to a 14 kDa beta-galactoside-binding lectin (L-14) from sheep spleen has been studied in 10 nM phosphate/150 mM NaCl/10 mM beta-mercaptoethanol buffer, pH 7.4, and in the temperature range 285-300 K using titration calorimetry. The single-site binding constants of various sugars for the lectin were in the following order: N-acetyl-lactosamine thiodigalactoside > 4-methylumbelliferyl lactoside > lactose > 4-methylumbelliferyl alpha-D-galactoside > methyl-alpha-galactose > methyl-beta-galactose. Reactions were essentially enthalpically driven with the binding enthalpies ranging from -53.8 kJ/mol for thiodigalactoside at 301 K to -2.2 kJ/mol for galactose at 300 K, indicating that hydrogen-bonding and van der Waals interactions provide the major stabilization for these reactions. However, the binding of 4-methylumbelliferyl-alpha-D-galactose displays relatively favourable entropic contributions, indicating the existence of a non-polar site adjacent to the galactose-binding subsite. From the increments in the enthalpies for the binding of lactose, N-acetyl-lactosamine and thiodigalactoside relative to methyl-beta-galactose, the contribution of glucose binding in the subsite adjacent to that for galactose shows that glucose makes a major contribution to the stability of L-14 disaccharide complexes. Observation of enthalpy-entropy compensation for the recognition of saccharides such as lactose by L-14 and the absence of it for monosaccharides such as galactose, together with the lack of appreciable changes in the heat capacity (delta Cp), indicate that reorganization of water plays an important role in these reactions.

Uranium and thorium contents of coexisting gneisses, granites and pegmatites

U, Th and K contents of gneisses, granites and pegmatites of the Precambrian shield complex of S. E. Mysore have been determined by gamma ray spectrometry. Th/U ratios in most gneisses and granites are found to have values in the range 5–15, being higher than the accepted value of about 3.5 for crustal material.

Antipyrine complexes of titanium(IV), zirconium(iv), thorium(IV) and uranium(VI) perchlorates

Antipyrine complexes of TiO2+, ZrO2+, Zr4+, Th4+ and UO2+2 perchlorates with molecular formulae TiO(Apy)4(ClO4)2, ZrO(Apy)3(ClO4)2, Zr(Apy)6(ClO4)4, Th(Apy)7(ClO4)4 and UO2(Apy)5(ClO4)2 have been prepared and characterized. The complexes are stable in air at room temperature and decompose exothermally at ~3OO °C. The i.r. study indicates the bonding of the antipyrine to the metal ion through its carbonyl oxygen. The nature of the bonding of the perchlorate and the stereochemistry of the complexes are discussed in the light of infrared spectra, conductivity in solvents of different polarity, and molecular weight measurements. From the UO2+2 group frequencies, the force constant K and rU-o are found to be 6.29 × 105 dynes/ cm-1 and 1.74 Å, respectively.

Assessment of Nanoscience and Nanotechnology Initiatives in India

Nanotechnology is a new technology which is generating a lot of interest among academicians, practitioners and scientists. Critical research is being carried out in this area all over the world.Governments are creating policy initiatives to promote developments it the nanoscale science and technology developments. Private investment is also seeing a rising trend. Large number of academic institutions and national laboratories has set up research centers that are workingon the multiple applications of nanotechnology. Wide ranges of applications are claimed for nanotechnology. This consists of materials, chemicals, textiles, semiconductors, to wonder drug delivery systems and diagnostics. Nanotechnology is considered to be a next big wave of technology after information technology and biotechnology. In fact, nanotechnology holds the promise of advances that exceed those achieved in recent decades in computers and biotechnology. Much interest in nanotechnology also could be because of the fact that enormous monetary benefits are expected from nanotechnology based products. According to NSF, revenues from nanotechnology could touch $ 1 trillion by 2015. However much of the benefits are projected ones. Realizing claimed benefits require successful development of nanoscience andv nanotechnology research efforts. That is the journey of invention to innovation has to be completed. For this to happen the technology has to flow from laboratory to market. Nanoscience and nanotechnology research efforts have to come out in the form of new products, new processes, and new platforms.India has also started its Nanoscience and Nanotechnology development program in under its 10(th) Five Year Plan and funds worth Rs. One billion have been allocated for Nanoscience and Nanotechnology Research and Development. The aim of the paper is to assess Nanoscience and Nanotechnology initiatives in India. We propose a conceptual model derived from theresource based view of the innovation. We have developed a structured questionnaire to measure the constructs in the conceptual model. Responses have been collected from 115 scientists and engineers working in the field of Nanoscience and Nanotechnology. The responses have been analyzed further by using Principal Component Analysis, Cluster Analysis and Regression Analysis.

Heat transfer in rarefied couette flow on the basis of discrete ordinate method

The method of discrete ordinates, in conjunction with the modified "half-range" quadrature, is applied to the study of heat transfer in rarefied gas flows. Analytic expressions for the reduced distribution function, the macroscopic temperature profile and the heat flux are obtained in the general n-th approximation. The results for temperature profile and heat flux are in sufficiently good accord both with the results of the previous investigators and with the experimental data.

Diphenyl sulphox1de complexes of thorium(IV)

Thorium(IV) is known to form high coordination-number complexes. An attempt has therefore been made to determine the effect of anions on the coordination complexes of diphenyl sulphoxide (DPSO) with thorium(IV). The complexes formed have the formulae [Th(DPSO)6](ClO4)4, [Th(DPSO)4Cl4], [Th(DPSO)4Br4], [Th(DPSO)6I2]I2, [Th(DPSO)4(NCS)4]and [Th(DPSO)3(NO3)4]. In all the complexes, DPSO is coordinated to the metal ion through its oxygen. The electrical conductances in nitrobenzene and in nitromethane, and ebullioscopic molecular weights in acetonitrile, show that the perchlorate and iodide complexes behave as 1:4 and 1:2 electrolytes, respectively; while the other complexes are monomeric and non-electrolytes. The infrared spectra of the solid complexes indicate the ionic nature of the perchlorate, the bidentate nature of the nitrate and the coordination of the thiocyanate through its nitrogen. [Th(DPSO)4Cl4], [Th(DPSO)4Br4]and [Th-(DPSO)3 (NO3)4]decompose endothermically while [Th(DPSO)6](ClO4)4 and [Th(DPSO)4(NCS)4]decompose exothermically, both in air and in nitrogen. The perchlorate complex has octahedral symmetry around the thorium, the halo- and the thiocyanato complexes are 8-coordinate, probably with square antiprismatic structures, while the nitrate complex is 11-coordinate

Incremental attribute evaluation through recursive procedures

Incremental semantic analysis in a programming environment based on Attribute Grammars is performed by an Incremental Attribute Evaluator (IAE). Current IAEs are either table-driven or make extensive use of graph structures to schedule reevaluation of attributes. A method of compiling an Ordered Attribute Grammar into mutually recursive procedures is proposed. These procedures form an optimal time Incremental Attribute Evaluator for the attribute grammar, which does not require any graphs or tables.

Plastic response of orthotropic spherical shells under blast loading

The plastic response of a segment of a simply supported orthotropic spherical shell under a uniform blast loading applied on the convex surface of the shell is presented. The blast is assumed to impart a uniform velocity to the shell surface initially. The material of the shell is orthotropic obeying a modified Tresca yield hypersurface conditions and the associated flow rules. The deformation of the shell is determined during all phases of its motion by considering the motion of plastic hinges in different regimes of flow. Numerical results presented include the permanent deformed configuration of the shell and the total time of shell response for different degrees of orthotropy. Conclusions regarding the plastic behaviour of spherical shells with circumferential and meridional stiffening under uniform blast load are presented.

Elimination of common mode voltage and fifth and seventh harmonics in a multilevel inverter fed IM drive using 12-sided polygonal voltage spacephasor

A multilevel inverter with 12-sided polygonal voltage space vector structure is proposed in this paper. The present scheme provides elimination of common mode voltage variation and 5(th) and 7(th) order harmonics in the entire operating range of the drive. The proposed multi level structure is achieved by cascading only the conventional two-level inverters with asymmetrical DC link voltages. The bandwidths problems associated with conventional hexagonal voltage space vector structure current controllers, due to the presence of 5(th) and 7(th) harmonics, in the over modulation region, is absent in the present 12-sided structure. So a linear voltage control up to 12-step operation is possible, from the present twelve sided scheme, with less current control complexity. An open-end winding structure is used for the induction motor drive.

A unified model for auxiliary switch commutated DC-DC converters

A novel ZVS auxiliary switch commutated variation for all DGDC converter topologies has been proposed in 2006. With proper designation of the circuit variables (throw current I and the pole voltage V), all these converters are seen to be governed by an identical set of equations. With idealized switches, the steady-state performance is obtainable in an analytical form. The conversion ratio of the converter topologies is obtained. A generalized equivalent circuit emerges for all these converters from the steady-state conversion ratio. It also provides a dynamic model as well. With these generalized steady-state equivalent circuits, small signal analysis of these converters may be carried out readily. It enables one to use the familiar state space averaged results of the standard PWM DGDC converters for the resonant counterparts. Th dc and ac models reveals that dc and low frequency behaviour of the proposed family of converters is similiar to that of its PWM parent

Studies on design, fabrication and reliability assessment of embedded passives on a high-density interconnect (HDI) organic substrate using a sequential build-up process

One of the foremost design considerations in microelectronics miniaturization is the use of embedded passives which provide practical solution. In a typical circuit, over 80 percent of the electronic components are passives such as resistors, inductors, and capacitors that could take up to almost 50 percent of the entire printed circuit board area. By integrating passive components within the substrate instead of being on the surface, embedded passives reduce the system real estate, eliminate the need for discrete and assembly, enhance electrical performance and reliability, and potentially reduce the overall cost. Moreover, it is lead free. Even with these advantages, embedded passive technology is at a relatively immature stage and more characterization and optimization are needed for practical applications leading to its commercialization.This paper presents an entire process from design and fabrication to electrical characterization and reliability test of embedded passives on multilayered microvia organic substrate. Two test vehicles focusing on resistors and capacitors have been designed and fabricated. Embedded capacitors in this study are made with polymer/ceramic nanocomposite (BaTiO3) material to take advantage of low processing temperature of polymers and relatively high dielectric constant of ceramics and the values of these capacitors range from 50 pF to 1.5 nF with capacitance per area of approximately 1.5 nF/cm(2). Limited high frequency measurement of these capacitors was performed. Furthermore, reliability assessments of thermal shock and temperature humidity tests based on JEDEC standards were carried out. Resistors used in this work have been of three types: 1) carbon ink based polymer thick film (PTF), 2) resistor foils with known sheet resistivities which are laminated to printed wiring board (PWB) during a sequential build-up (SBU) process and 3) thin-film resistor plating by electroless method. Realization of embedded resistors on conventional board-level high-loss epoxy (similar to 0.015 at 1 GHz) and proposed low-loss BCB dielectric (similar to 0.0008 at > 40 GHz) has been explored in this study. Ni-P and Ni-W-P alloys were plated using conventional electroless plating, and NiCr and NiCrAlSi foils were used for the foil transfer process. For the first time, Benzocyclobutene (BCB) has been proposed as a board level dielectric for advanced System-on-Package (SOP) module primarily due to its attractive low-loss (for RF application) and thin film (for high density wiring) properties.Although embedded passives are more reliable by eliminating solder joint interconnects, they also introduce other concerns such as cracks, delamination and component instability. More layers may be needed to accommodate the embedded passives, and various materials within the substrate may cause significant thermo -mechanical stress due to coefficient of thermal expansion (CTE) mismatch. In this work, numerical models of embedded capacitors have been developed to qualitatively examine the effects of process conditions and electrical performance due to thermo-mechanical deformations.Also, a prototype working product with the board level design including features of embedded resistors and capacitors are underway. Preliminary results of these are presented.