Search

We have investigated the signal for physics beyond the Standard Model via Higgs plus photon final state, hitherto unobserved at the LHC, in the framework of Standard Model Effective Field Theory. Using the relevant dimension-6 operators, we probe two distinct classes of interactions, based on the Lorentz structure of Higgs couplings to gauge bosons and fermions. To begin with, constraints on the Wilson coefficients of these operators have been derived from existing experimental data. We then focus on the hadronic decay of the Higgs boson to two bottom quarks in the boosted regime, leading to a high pT fat-jet recoiling against a hard photon. Following a CMS Run II search for a heavy resonance decaying into a Higgs boson and a photon, a detailed signal and background analysis for this channel has been done and limits on the relevant Wilson coefficients have been obtained. By performing a cut-based analysis, we identify some kinematic observables that distinguish between signal and SM background. Minimum values of the Wilson coefficients that will yield 3σ signal significance at the 14 TeV run of the LHC with 3000 fb−1 data, have been obtained. A multivariate analysis using a boosted decision tree and exploiting the jet substructure techniques further help to isolate the regions of phase space where the contribution of SMEFT driven signal is significantly enhanced. Finally, we briefly discuss the parameter dependencies and interpretations of the allowed values of the coefficients on a particularly interesting UV complete model namely, the Minimal Supersymmetric Standard Model. [ABSTRACT FROM AUTHOR]

We study the impact of H2 enrichment on the unsteady flow dynamics and thermoacoustic instability in the prediction and control of instabilities in industrial turbines (PRECCINSTA) swirl combustor. The experiments were performed at atmospheric conditions with H2/CH4 fuel mixtures at a global equivalence ratio of 0.65 and a constant thermal power of 20 kW. We analyze data with three fuel compositions: 0%, 20%, and 50% H2 in two operating modes, premixed (PM) and technically premixed (TPM). A new multiresolution modal decomposition method, using a combination of wavelet transforms and proper orthogonal decomposition (WPOD) is performed on time resolved flow velocity and OH planar laser induced fluorescence (OH planar laser induced fluorescence (OH-PLIF)) measurements. Thermoacoustic oscillations are observed in the TPM operating mode alone, indicating that the primary heat release driving mechanism is due to fuel-air ratio oscillations. WPOD results for the 0%H2 TPM case reveal intermittent helical precessing vortex core (PVC) oscillations along with axisymmetric hydrodynamic flow oscillations due to the thermoacoustic oscillations. These oscillations cause local flame extinction near the nozzle centerbody resulting in liftoff. A PVC then develops in the flow and enables intermittent flame reattachment. In the 0% H2 premixed case, the flame remains lifted off the centerbody despite the presence of PVC oscillations. H2 enrichment results in the suppression of flame liftoff and the PVC in both operating modes. We show from flow strain rate statistics and extinction strain rate calculations that the increase of the latter with H2 addition, allows the flame to stabilize in the region near the centerbody where the pure CH4 cases show lift off. [ABSTRACT FROM AUTHOR]

Nanoporous BaTiO3 particles with an average diameter of 27 nm have been synthesized using a soft template based on poloxamer. The pore width has been found to be ∼10 nm. The nanoporous particles have a surface area of 107 m2gm-1. This introduces a large surface area leading to the creation of a large number of oxygen vacancies. The latter contributes to the ferromagnetic behavior of the nanoparticles. A multiferroic property was exhibited by these particles. The oxygen vacancy concentration decreased as the BaTiO3 particle size increased. The magnetization decreased with an increase in the particle size. A magnetodielectric parameter of 11% has been observed in this system corresponding to an applied magnetic field of 10 kOe. [ABSTRACT FROM AUTHOR]

The nonradiative rate in 3-aminoquinoline is found to exhibit anomalous solvent dependence, being rather fast in nonpolar solvents and remarkably slower in more polar and especially, more protic ones. The cause of such behavior is investigated by studying the dependence of fluorescence spectral and temporal parameters on the solvent properties such as polarity and hydrogen bonding ability. Complementary quantum mechanical calculations have been performed and the picture that emerges from these studies is that of an excited state with a short radiative lifetime due to the flipping of the amino group. This state is selectively populated in nonpolar, nonhydrogen bonding solvents, but is destabilized with respect to the more polar intramolecular charge transfer (ICT) state in polar solvents and even more so in protic solvents and dimethylsulfoxide. The slower nonradiative rates in the ICT state is attributed to the more restricted motion of the amino group in this state. The role of hydrogen bonding of the amino group and the ring nitrogen in stabilization/destabilization of the ICT state and therefore on the nonradiative rate is also explored. [ABSTRACT FROM AUTHOR]

Single particle level microscopy of immobilized FAPbBr3 nanocrystals (NCs) has elucidated the involvement of different processes in their photoluminescence (PL) intermittency. Four different blinking patterns are observed in the data from more than 100 NCs. The dependence of PL decays on PL intensities brought out in fluorescence lifetime intensity distribution (FLID) plots is rationalized by the interplay of exciton- and trion-mediated recombinations along with hot carrier (HC) trapping. The high intensity-long lifetime component is attributed to neutral exciton recombination, the low intensity-short lifetime component is attributed to trion assisted recombination, and the low intensity-long lifetime component is attributed to hot carrier recombination. Change-point analysis (CPA) of the PL blinking data reveals the involvement of multiple intermediate states. Truncated power law distribution is found to be more appropriate than power law and lognormal distribution for on and off events. Probability distributions of PL trajectories of single NCs are obtained for two different excitation fluences and wavelengths (λex = 400, 440 nm). Trapping rate (kT) prevails at higher power densities for both excitation wavelengths. From a careful analysis of the FLID and probability distributions, it is concluded that there is competition between the HC and trion assisted blinking pathways and that the contribution of these mechanisms varies with excitation wavelength as well as fluence. [ABSTRACT FROM AUTHOR]

The doping of CdS quantum dots (QDs) with Cu(I) disrupts electron–hole correlation due to hole trapping by the dopant ion, post-photoexcitation. The present paper examines the effect of such disruption on the rate of photoinduced electron transfer (PET) from the QDs to methyl viologen (MV2+), with implications in their photocatalytic activity. A significantly greater efficiency of PL quenching by MV2+ is observed for the doped QDs than for the undoped ones. Interestingly, the Stern–Volmer plots constructed using PL intensities exhibit an upward curvature for both the cases, while the PL lifetimes remain unaffected. This observation is rationalized by considering the adsorption of the quencher on the surface of the QDs and ultrafast PET post-photoexcitation. Ultrafast transient absorption experiments confirm a faster electron transfer for the doped QDs. It is also realized that the transient absorption experiment yields a more accurate estimate of the binding constant of the quencher with the QDs, than the PL experiment. [ABSTRACT FROM AUTHOR]

Fluorescence experiments at high fluorophore concentrations or in solid state have biological relevance and application potential in devices. Inner filter effect, arising from reabsorption of emitted photons, is the simplest of several factors that complicate the emission in these systems. This effect is prominent, especially for systems with small Stokes shift between absorption and emission. Solid state ‘dilution’ of a fluorophore with an optically transparent, noninterfering substance can significantly minimize this effect. This has been shown in the present study, using salophen as a fluorophore and NaCl as the dilutant. The general applicability of this method is tested with three more fluorophores. [ABSTRACT FROM AUTHOR]

We consider an incarnation of left-right symmetric model with a local gauge symmetry of S U (3) C ⊗ S U (2) L ⊗ U (1) L ⊗ S U (2) R ⊗ U (1) R. Heavy scalars and fermions present in the 27 of E 6 are included in the matter sector along with the Standard Model (SM) fermions. Two such colour singlet fermions, N and L S , transforming as bi-doublet and singlet under S U (2) s respectively, can be potential candidates for Dark Matter (DM). Assignment of U (1) charges for the matter fields restricts some of the exotic fermions to interact with the SM fermions. We study in some details the prospect of such fermionic dark matters by calculating relic densities and direct detection cross-sections by treating both these particles as relics. In such a two component Dark Matter scenario, L S having smaller interaction with the SM, will dominantly contribute to relic density. However, it cannot be detected at earth bound experiments with their present sensitivity. On the contrary, N having higher rate of interaction with the SM particle has too large annihilation cross-section thus contributes very little to relic density. In fact, its interaction with the SM is too high such that N -nucleon cross-section for a wide range of N mass is higher than the experimental limits from XENON, LUX or PICO. However, such a high N -nucleon cross-section can be tamed by assuming additional dimension-6 operators involving N and SM quarks. We derive limits on the strengths of such interactions from experimental data. [ABSTRACT FROM AUTHOR]

Electroweak observables are highly sensitive to the loop corrections. Therefore, a proper gauge-fixing mechanism is always needed to define the propagators which are involved in Feynman loop amplitude. With this spirit, we compute gauge-fixing mechanism in five-dimensional (5D) universal extra-dimensional (UED) model with boundary localized terms (BLTs). These BLTs are not 5D operators in four-dimensional (4D) effective theory but some sort of boundary conditions on the respective fields at the fixed points of orbifold. Furthermore, these BLTs nontrivially modify the Kaluza-Klein (KK) spectra and some of the interactions among the KK-excitations compared to the minimal UED (mUED), in which, these BLTs are absent. In this note, we calculate the gauge-fixing mechanism in the electroweak sector of such nontrivial UED scenario. Moreover, we discuss the composition and masses of Goldstone and any physical scalar that emerge after the symmetry breaking in this set up with different choices of gauge. [ABSTRACT FROM AUTHOR]

Membrane-based separation is a superior alternative to conventional processes in many separation problems of practical importance. For maximum effectiveness, both high selectivity and flux are desirable. This article summarizes the global efforts at designing new membrane materials, particularly carbon nanotube (CNT)-based membranes, to achieve the twin objectives mentioned above. Interest in CNT emanates from the excellent transport property of molecules through its frictionless smooth walls, with/without functionalization at the end tips. Permeation of water through graphene oxide (GO) channels, which are otherwise impermeable to solutes, has also generated considerable interest, and GO is being viewed as a promising material for separations. The performances of conducting polymers like polypyrrole, polyaniline, polythiophene-3, 4-ethylenedioxythiophene and their different composites have been studied as a function of changes in morphology and redox behaviour, and this aspect too is covered in the present article. Also, the dependence of the separation performances based on the size, charge and hydrophobic/hydrophilic properties has been discussed in detail. Advances in understanding will have an important bearing on future developments in separation science. [ABSTRACT FROM AUTHOR]

Effectsof annealing have been studied on the chemical structure,water uptake, and acidity of the cast Nafion thin film of thickness∼ 6 μm using a fluorescent probe, 2-(3′-pyridyl)benzimidazole(3PBI), and attenuated total reflactance infrared (ATR-IR) spectroscopy.Nonannealed films and thick Nafion 117 membrane have been used asreference materials, in order to develop a complete understandingof the effect. Annealing has been found to cause a decrease in acidityof otherwise highly acidic ionomer, as sensed by the fluorescent probeand loss of water, as reflected in the ATR-IR spectrum. This observationis surprising and cannot be explained in the light of previous reportsof physical changes. Our ATR-IR study has revealed changes in thechemical structure of the hydrophilic part of the ionomer, leadingto the formation of sulfonic acid anhydrides. This phenomenon canrationalize the decreased acidity reported in our fluorescence study.Interestingly, acid treatment of the annealed film restores the acidityof the unannealed films. This cannot be rationalized simply by a greaterproton uptake from the solution, as the film has to be electroneutral.It appears that the anhydrides formed during the annealing processundergo acid hydrolysis, leading to an increase in the number of SO3–groups and, consequently, an increasein the number of H3O+ions in the water channels.Besides, the films can be hydrated to an extent that is much greaterthan Nafion membranes, but the water uptake of acid treated annealedfilm is slightly less than that of nonannealed films. Hence, we concludethat, along with annealing, acid treatment, a procedure that is generallynot performed on the cast films, is an important pretreatment procedureto improve the acidity and hence the transport properties of the castfilm. [ABSTRACT FROM AUTHOR]

The conductivity of polyaniline (PANI)is ascribed to its emeraldinesalt (PANI-ES), which is formed by protonation of its emeraldine base(PANI-EB) by acids. Generally, mineral acids are used for this purpose,but the use of dopants and additives to maintain the required acidityprovides an alternative method to the preparation of PANI-ES. Thepresent work attempts to achieve the protonation by the use of a weakorganic acid, namely, 6-cyano-2-naphthol (6CN2), which is generallyused as a superphotoacid, as its excited state pKais significantly smaller than its ground state pKa. The question here is if the protonation ofthe aniline moieties in PANI takes place and if it does, whether ittakes place by dissociation of the ground state or the excited stateof 6CN2. Room temperature conductance measurements were carried outto see the effect of doping. The formation of PANI-ES from PANI-EBhas been monitored by UV–vis spectrophotometry. When a polarcounterion is inserted into the polymer matrix, it changes the environmentof the nearby chains by introducing defects, reorganization of chargesas a result of interaction with the polymer. Morphological investigationwas done using optical microscopy, field emission gun scanning electronmicroscopy (FEGSEM), and field emission gun transmission electronmicroscopy FEGTEM. The influence of 6CN2 on the crystallinity of thepolymer was determined by X-ray diffraction (XRD). [ABSTRACT FROM AUTHOR]

Abstract: In five-dimensional universal extra-dimensional models compactified on an orbifold four-dimensional kinetic terms are allowed at the two fixed points. If these terms are unequal then Kaluza–Klein (KK) parity is broken. Within such a framework we consider resonant production of the KK-gluon at the LHC and its subsequent decay to , where both production and decay are KK-parity non-conserving. We use, for the first time, the exclusion data for a resonance obtained by the LHC experiments to limit the mass range of the lowest gluon excitation and, in a correlated fashion, of the quark excitation of the KK-parity-violating model which are both found to be in the ballpark of 600–2000 GeV. [Copyright &y& Elsevier]

This paper reports large eddy simulations (LES) of a premixed turbulent round methane-air jet flame at an equivalence ratio of 0.8 and unburnt gas temperature of 800 K using the explicit filtering LES (EFLES) method. The nominal 1D premixed flame speed, s L = 2.05 ms − 1 and thermal thickness, δ L = 300 μ m. EFLES is formally derived from the approximate deconvolution method for LES computations. The nominal turbulent Reynolds number R e t = 34 and the turbulent Karlovitz number K a = 25 places the present flame in the thin reaction zones regime of turbulent premixed combustion. LES and DNS results are obtained by solving species transport equations using a reduced 13-species chemical mechanism. Chemical source terms in the LES are computed using resolved species and temperature fields in all simulations. Conditional means of net heat release rate predicted by the LES and DNS show excellent agreement. The LES results show a marginally thicker flame brush and a shorter mean flame height when compared to the DNS results. Good agreement between LES and DNS for mean quantities is seen upstream of the tip. Larger quantitative differences are seen at the tip due to the difference in flame height between LES and DNS cases, as may be expected. Even at these positions, qualitative features of the DNS results and peak mean values are recovered correctly. Agreement between conditional mean statistics from both LES and DNS is good. RMS fluctuation amplitudes show larger quantitative differences between LES and DNS when compared to mean statistics while still capturing the correct qualitative features of the DNS profiles. The radial profiles of unconditioned RMS fluctuations are broader by O (δ L) in the LES results, with increasing downstream distance. The smaller range of resolved scales in the LES causes the resolved flow motions to be more energetic resulting in increased turbulent transport rates for mean and RMS quantities. This results in the observed broadening of flow statistics in the LES when compared to the DNS. With mesh refinement, differences between LES and DNS results for all statistics are found to diminish smoothly. [ABSTRACT FROM AUTHOR]

Prof. Anindya Datta introduces the Department of Chemistry at IIT Bombay and reviews its achievements and future goals. [ABSTRACT FROM AUTHOR]

Thebehavior of lamellar structures of Aerosol OT (AOT) as hosts,vis-à-vis the flexible normal micelles and rigid nanochannelsof Nafion membranes, has been investigated with two different fluorophores,[2,2′-bipyridyl]-3,3′-diol (BP(OH)2) andcoumarin 102 (C102). Surprisingly, for BP(OH)2, a risetime is observed at intermediate emission wavelengths and not in thered edge of the fluorescence spectrum. A shoulder at 525 nm is observedin time resolved emission spectra (TRES) at initial times of BP(OH)2in AOT lamellar structures. This feature is the signatureof the monoketo (MK) tautomer, observed for the first time in a microheterogeneousmedium. Also, the usually ultrafast single proton transfer in BP(OH)2is retarded to an considerable extent in lamellar structures.The potential of this medium in promoting unusual intermediates isthus highlighted. This property may be ascribed to the rigidity oflamellar structures, compared to hosts such as regular micelles. However,studies using another fluorophore, coumarin 102 (C102), brings outthe fact that these structures are significantly different from therigid host, Nafion, as well. The absence of excited state proton transfer(ESPT) in this molecule in AOT lamellar structures indicates thatit is not protonated, unlike in Nafion. Thus, the interfacial pH oflamellar structures is found to be significantly greater than thatof Nafion nanochannels. From the time dependent Stokes shift (TDSS)of the emission spectra of C102, the relaxation time (0.85 ns) ofinterfacial water in lamellar structures is found to be an order ofmagnitude faster than that observed in Nafion nanochannels, in whichH3O誉 have been substituted by differentcations. Hence, this study demonstrates that AOT lamellar structuresare rather unique hosts and that they behave very differently fromconventional rigid and flexible hosts such as normal micelles andNafion, respectively. [ABSTRACT FROM AUTHOR]

In this paper, we describe the design and implementation of a reverse dictionary. Unlike a traditional forward dictionary, which maps from words to their definitions, a reverse dictionary takes a user input phrase describing the desired concept, and returns a set of candidate words that satisfy the input phrase. This work has significant application not only for the general public, particularly those who work closely with words, but also in the general field of conceptual search. We present a set of algorithms and the results of a set of experiments showing the retrieval accuracy of our methods and the runtime response time performance of our implementation. Our experimental results show that our approach can provide significant improvements in performance scale without sacrificing the quality of the result. Our experiments comparing the quality of our approach to that of currently available reverse dictionaries show that of our approach can provide significantly higher quality over either of the other currently available implementations. [ABSTRACT FROM AUTHOR]

With the popularity of mobile apps on mobile devices based on iOS, Android, Blackberry and Windows Phone operating systems, the numbers of mobile apps in each of the respective native app stores are increasing in leaps and bounds. Currently there are close to one million mobile apps across these four major native app stores. Due to the enormous number of apps, both the constituents in the app ecosytem, consumers and app developers, face problems in 'app discovery'. For consumers, it is a daunting task to discover the apps they like and need among the huge number of available apps. Likewise, for developers, enabling their apps to be discovered is a challenge. To address these issues, Mobilewalla (MW) an app search engine provides an independent unbiased search for mobile apps with semantic search capabilities. It has also developed an objective scoring mechanism based on user and developer involvement with an app. The scoring mechanism enables MW to provide a number of other ways to discover apps-such as dynamically maintained 'hot' lists and 'fast rising' lists. In this paper, we describe the challenges of developing the MW platform and how these challenges have been mitigated. Lastly, we demonstrate some of the key functionalities of MW. [ABSTRACT FROM AUTHOR]

Abstract: The effect of micelles on ground and excited state prototropism of 2-(4′-pyridyl)benzimidazole (4PBI) has been studied by fluorescence spectroscopy. It has been observed that in sodium dodecyl sulfate (SDS) micelle, 4PBI is preferentially protonated at the pyridyl nitrogen atom, in contrast to the situation in neat aqueous solutions, in which imidazole and pyridyl nitrogen atoms have equal propensity for protonation. In SDS, the protonation of the benzimidazole nitrogen occurs only in the excited state. Such effects are not observed in cationic cetyl trimethyl ammonium bromide (CTAB) and neutral Triton X-100 (TX-100). Thus, 4PBI shows very good sensitivity for negatively charged interfaces between aqueous and apolar compartments in microheterogeneous media. [Copyright &y& Elsevier]

Nanoporous NiZnFeO particles of diameter, ~ 9·5 nm, were synthesized by citric acid assisted thermal decomposition in an autoclave. The BET surface area measured was 80 m g and the average pore diameter was 2·5 nm. By soaking the particles in a suitable precursor solution and then subjecting them to a heat treatment at 923 K for 3 h, Pb(ZrTi)O was grown within the nanopores. X-ray and electron diffraction studies confirmed the presence of both these phases. The nanocomposites showed ferromagnetic behaviour over the temperature range 2-300 K. No ferroelectric hysteresis loop could be found which was consistent with the earlier theoretical prediction of loss of ferroelectricity below a critical thickness of 2·4 nm. Good magneto-dielectric response of the order of 7% at a magnetic field of 9 kOe was recorded for the present system. This is believed to arise due to a negative magnetostriction coefficient of NiZnFeO which exerted a compressive strain on Pb(ZrTi)O thereby lowering the tetragonality in its crystal structure. [ABSTRACT FROM AUTHOR]

2-(4′-Pyridyl)benzimidazole (4PBI) has been usedto investigate the microheterogeneity of water nanochannels of Nafionmembranes at two different hydration levels. Native as well as cation-exchangedNafion membranes are found to protonate one of the two monoprotonatedforms of 4PBI selectively. In native membranes and in those in whichH3O+ions are replaced by (CH3)4N+ions, the pyridyl nitrogen is protonated preferentially.In Na+-exchanged membranes, however, the benzimidazolenitrogen is protonated selectively. Unlike other fluorescent probesused in earlier studies, 4PBI can differentiate between the two differentcation-exchanged membranes at lower as well as higher hydration levels. [ABSTRACT FROM AUTHOR]

Abstract: We propose a new search strategy based on the event shape variables for new physics models where the separations among the masses of the particles in the spectrum are small. Collider signature of these models, characterized by low leptons/jets and low missing , are known to be difficult to look for. The conventional search strategies involving hard cuts may not work in such situations. As a case study, we have investigated the hitherto neglected jets+missing signature – known to be a challenging one – arising from the pair productions and decay of KK-excitations of gluons and quarks in the minimal Universal Extra Dimension (mUED) model. Judicious use of the event shape variables enables us to reduce the Standard Model backgrounds to a negligible level. We have shown that in mUED, up to can be explored or ruled out with 12 fb−1 of integrated luminosity at the 7 TeV run of the LHC. We also discuss the prospects of employing these variables for searching other beyond Standard Model physics with compressed or partially compressed spectra. [Copyright &y& Elsevier]

(2,2′-Bipyridyl)-3-3′-diol (BP(OH)2) undergoesexcited state intramolecular double proton transfer (ESIDPT). Thephotophysics of this molecule has been investigated, in the highlyacidic water channels inside nafion membrane. The dianionic enolateform of the dye, which is formed only in alkaline conditions in neataqueous solutions, is found to be present in its excited state innative nafion membrane at low water content. This surprising phenomenonhas been explained in the light of loss of protons from the fluorophoreto the medium, due to increased electrostatic interactions with thependant sulfonate groups of nafion, at the lower water content. Thisobservation fortifies the model of microscopic interactions that wehave proposed in recent past. Further, the ground state of the diketoform, observed only in neat aqueous solutions so far, is found tobe present in Na+exchanged membranes at lower levels ofhydration. The steady-state spectral features of the dye is differentin (CH3)4N+exchanged membranes thanthat of Na+exchanged membranes, unlike in our earlierstudies with coumarin 102 and 2-(2′-pyridyl)benzimidazole,here we observed formation of an unusual ground state in Na+exchanged membranes, while no such feature was observed in (CH3)4N+exchanged membranes. [ABSTRACT FROM AUTHOR]

A molecular level understanding of the mobility of cations in the Nafion membrane has been attempted, using the excited state proton transfer (ESPT) process in the fluorescent probe Coumarin 102. ESPT is hindered significantly upon decreasing the water content. Using TRANES (time-resolved area normalized emission spectroscopy), the evolution of the ESPT state is clearly observed over hundreds of picoseconds in lower water content, implying that ESPT is hindered even in the nanovolume probed by the dye. Most remarkably, in the partially dried membrane, the predominant fluorescent species is the zwitterionic form, generated by excited state deprotonation of the cationic form. This implies that the molecule loses a proton from its nitrogen center in the excited state, as usual, but cannot recapture it readily at the oxygen center, at low water contents. This phenomenon is rationalized in light of an increased electrostatic attraction that is experienced by cations upon drying. [ABSTRACT FROM AUTHOR]

Abstract: Li2O–SiO2 glasses with Li2O content up to 35mol% in nanoscale dimensions have been synthesized within the pores of a pellet formed by CuO nanoparticles of diameter 17nm. The resistivities of the nanoglasses produced are almost four orders of magnitude lower than that of the bulk glass of similar composition. The activation energy of conduction is also smaller than the bulk counterpart. This is due to an increase in free volume of the nanoglass because it cannot relax into its metastable configuration as a result of nanosize effect. The high frequency exponent of the frequency dependent electrical conductivity has a value characterizing one-dimensional ionic transport. [Copyright &y& Elsevier]

Abstract: Besides supersymmetry, the other prime candidate of physics beyond the Standard Model (SM), crying out for verification at the CERN Large Hadron Collider (LHC), is extra-dimension. To hunt for effects of Kaluza–Klein (KK) excitations of known fermions and bosons is very much in the agenda of the LHC. These KK states arise when the SM particles penetrate in the extra space-like dimension(s). In this paper, we consider a 5d scenario, called ‘Universal Extra Dimension’, where the extra space coordinate, compactified on an orbifold , is accessed by all the particles. The KK number (n) is conserved at all tree level vertices. This entails the production of KK states in pairs and renders the lightest KK particle stable, which leaves the detector carrying away missing energy. The splitting between different KK flavors is controlled by the zero mode masses and the bulk- and brane-induced one-loop radiative corrections. We concentrate on the production of an KK electroweak gauge boson in association with an KK quark. This leads to a signal consisting of only one jet, one or more leptons and missing . For definiteness we usually choose the inverse radius of compactification to be , which sets the scale of the lowest lying KK states. We show on a case-by-case basis (depending on the number of leptons in the final state) that with 10 fb−1 integrated luminosity at the LHC with this signal can be detected over the SM background by imposing appropriate kinematic cuts. We record some of the expectations for a possible intermediate LHC run at and also exhibit the integrated luminosity required to obtain a 5σ signal as a function of . [Copyright &y& Elsevier]

The binding of two model photodynamic therapy drugs, chlorin p 6 and purpurin 18, with surfactants has been studied using steady-state and time-resolved fluorescence techniques. The surfactants used are amphiphilic nonionic surfactant (Tween 80 and Tween 40) and zwitterionic surfactant (HAPS). These have applications in drug delivery. The studies have been performed at pH 7 and 5 for chlorin p 6 and at pH 7 for purpurin 18. The binding constants have been estimated from the change in fluorescence parameters and have been compared with those for Cremophor EL and human serum albumin. Chlorin p 6 is found to bind to the surfactants to a greater extent at pH 5 than at pH 7. The same ionic species of chlorin p 6 is found to exist at the maximum concentrations of the surfactants. [ABSTRACT FROM AUTHOR]

Abstract: We discuss the phenomenology of -mode adjoint scalars in the framework of two Universal Extra Dimensions. The Kaluza–Klein (KK) towers of these adjoint scalars arise in the 4-dimensional effective theory from the 6th component of the gauge fields after compactification. Adjoint scalars can have KK-number conserving as well as KK-number violating interactions. We calculate the KK-number violating operators involving these scalars and two Standard Model fields. Decay widths of these scalars into different channels have been estimated. We have also briefly discussed pair-production and single production of such scalars at the Large Hadron Collider. [Copyright &y& Elsevier]

Abstract: We discuss collider signatures of th Kaluza–Klein (KK) mode vector bosons in the framework of two universal extra dimension model, at a future collider. Production of and , the th KK mode vector bosons, are considered in association with a hard photon. Without caring about the decay products of or , one can measure the masses of these particles just by looking at the photon energy distribution. Once produced () dominantly decays to a pair of jets or to a pair of top quarks. Thus we look for a pair of jets or a pair of top quarks in association with a photon. Upto the kinematic limit (with center-of-mass energies of 0.5 TeV and 1 TeV) of the collider, signals from the production and decay in both the above mentioned channels are greater than the 5σ fluctuation of the Standard Model background with integrated luminosity. However, the number of events from production and decay is smaller and its detection prospect is not very good. [Copyright &y& Elsevier]

We study the dilepton–dijet signal in the dominant Higgs production channel at a linear e+e- collider. We estimate the effects of universal extra dimension (UED) by a simple analysis of the cross-sections. The heavy Kaluza–Klein excitations of the Standard Model fields in UED can significantly alter the decay properties of the Higgs boson to loop-driven final states. We show that by taking a simple ratio between cross-sections of two different final states this difference can be very easily highlighted. [ABSTRACT FROM AUTHOR]

Modern Web-based application infrastructures are based on clustered multitiered architectures, where request distribution occurs in two sequential stages: over a cluster of Web servers and over a cluster of application servers. Much work has focused on strategies for distributing requests across a Web server cluster in order to improve the overall throughput across the cluster. The strategies applied at the application layer are the same as those at the Web server layer because it is assumed that they transfer directly. In this paper, we argue that the problem of distributing requests across an application server cluster is fundamentally different from the Web server request distribution problem due to core differences in request processing in Web and application servers. We devise an approach for distributing requests across a cluster of application servers such that the overall system throughput is enhanced, and load across the application servers is balanced. [ABSTRACT FROM AUTHOR]

Synchronous fluorescence and time-resolved fluorescence spectroscopic studies that reveal the interaction of epicocconone with human serum albumin is significantly different from its interaction with surfactant assemblies. This observation, along with steady-state fluorescence data, indicates ground-state interaction between the fluorophore epicocconone and the protein. Similarity in fluorescence properties with the adduct of the fluorophore with n-butylamine indicates that bonding occurs at the N-terminus of the protein. [ABSTRACT FROM AUTHOR]

Abstract: We study the power law running of gauge, Yukawa and quartic scalar couplings in the universal extra dimension scenario where the extra dimension is accessed by all the standard model fields. After compactifying on an orbifold, we compute one-loop contributions of the relevant Kaluza–Klein (KK) towers to the above couplings up to a cutoff scale Λ. Beyond the scale of inverse radius, once the KK states are excited, these couplings exhibit power law dependence on Λ. As a result of faster running, the gauge couplings tend to unify at a relatively low scale, and we choose our cutoff also around that scale. For example, for a radius , the cutoff is around 30 TeV. We then examine the consequences of power law running on the triviality and vacuum stability bounds on the Higgs mass. We also comment that the supersymmetric extension of the scenario requires to be larger than in order that the gauge couplings remain perturbative up to the scale where they tend to unify. [Copyright &y& Elsevier]

Abstract: The interaction of the fluorescent probe 3-phenylureidoquinoline with surfactant assemblies has been investigated using fluorescence spectroscopic and computational techniques. The non-radiative deactivation rates are found to be suppressed in micelles. In the negatively charged SDS micelle, the cation is found to form, leading to a marked shift in fluorescence. This is explained by a consideration of the local pH and altered pK a of the fluorophore. In reverse micelle the gradual addition of water remarkably enhances the rate of non-radiative depopulation. [Copyright &y& Elsevier]

Abstract: Absorption, fluorescence and light scattering techniques have been used to monitor the deaggregation of purpurin 18, a model of hydrophobic photosensitizers for photodynamic therapy, in aqueous micelles, microemulsions and human serum albumin. The aggregates present in the neat aqueous solvents are found to undergo deaggregation in these media to different extents. Aqueous micelles and microemulsions are found to induce a complete deaggregation whereas the process is only partial in albumins. This could be an indication of the fact that such hydrophobic photosensitizers are likely to be aggregated in the blood stream, but are probably in monomeric form, upon cellular uptake. The formation of surfactant-induced aggregates at intermediate concentrations of the positively charged CTAB is also observed and is explained in the light of electrostatic interactions between the fluorophore and the surfactant. [Copyright &y& Elsevier]

Abstract: The binding of chlorin p 6 with Cremophor EL (CrEL) at pH 5 and pH 7 has been monitored by fluorescence techniques. Upon binding with the drug delivery agent, the fluorescent species are found to be one and the same at both pH values. This is explained by a hindrance to protonation of chlorin p 6 trianions by Cremophor EL. Surprisingly, it is the more hydrophilic species between the two possible chlorin p 6 ions that is found to get bound preferentially with the hydrophobic delivery medium. [Copyright &y& Elsevier]

Abstract: We show that atmospheric neutrinos can provide a sensitive and robust probe of CPT violation (CPTV). We perform realistic event-rate calculations and study the variations of the ratio of total muon to antimuon survival rates with and L (L≡ baseline length, E ≡ neutrino energy) in a detector capable of identifying the muon charge. We demonstrate that measurements of these ratios when coupled with the significant L and E range which characterizes the atmospheric neutrino spectrum provides a method of both detecting the presence of such violations and putting bounds on them which compare very favorably with those possible from a future neutrino factory. [Copyright &y& Elsevier]

The photophysical properties of porphyrins with N3S and N3O cores appended with two boron-dipyrrin units and porphyrins with N2S2 and N4 cores appended with four boron-dipyrrin units are described. The steady-state fluorescence measurements indicate that the energy transfer from boron-dipyrrin units to the porphyrin unit is efficient with N4 and N3O porphyrin cores and less efficient with N3S and N2S2 cores. The energy transfer rates calculated from lifetime measurements are also in support with these observations. [Copyright &y& Elsevier]

We study the production of a single sneutrino in association with one or two b-quarks at hadron colliders, in the framework of an R-parity violating supersymmetric model. We find that at the Large Hadron Collider (LHC) four b final states are promising with efficient b-tagging. l+l′- decay modes of the sneutrino can also be viable for detection at the LHC. However, the branching ratio for rare γγ decay channel is too small to be seen. [Copyright &y& Elsevier]

As Internet traffic continues to grow and websites become increasingly complex, performance and scalability are major issues for websites. Websites are increasingly relying on dynamic content generation applications to provide website visitors with dynamic, interactive, and personalized experiences. However, dynamic content generation comes at a cost--each request requires computation as well as communication across multiple components. To address these issues, various dynamic content caching approaches have been proposed. Proxy-based caching approaches store content at various locations outside the site infrastructure and can improve website performance by reducing content generation delays, firewall processing delays, and bandwidth requirements. However, existing proxy-based caching approaches either (a) cache at the page level, which does not guarantee that correct pages are served and provides very limited reusability, or (b) cache at the fragment level, which is associated with several design-level and runtime scalability issues. To address these issues, several back-end caching approaches have been proposed, including query result caching and fragment level caching. While back-end approaches guarantee the correctness of results and offer the advantages of fine-grained caching, they neither address firewall delays nor reduce bandwidth requirements. In this article, we present an approach and an implementation of a dynamic proxy caching technique which combines the benefits of both proxy-based and back-end caching approaches, yet does not suffer from their above-mentioned limitations. Our dynamic proxy caching technique allows granular, proxy-based caching in highly dynamic scenarios, accessible outside the site infrastructure. We present two possible configurations for our dynamic proxy caching technique: (1) a reverse proxy configuration, and (2) a forward proxy configuration. Analysis of the performance of our approach indicates that it is capable of providing significant reductions in bandwidth. We have deployed our proposed dynamic proxy caching technique at a major financial institution. The results of this implementation indicate that our technique is capable of providing up to 3x reductions in bandwidth and response times in real-world dynamic Web applications when compared to existing caching solutions. [ABSTRACT FROM AUTHOR]

A simple consequence of the angular momentum conservation in quantum field theories is that the interference of s-channel amplitudes exchanging particles with different spin J vanishes after complete angular integration. We show that, while this rule holds in scattering processes mediated by a massive graviton in quantum gravity, a massless graviton s-channel exchange breaks orthogonality when considering its interference with a scalar-particle s-channel exchange, whenever all the external states are massive. As a consequence, we find that, in the Einstein theory, unitarity implies that angular momentum is not conserved at quantum level in the graviton coupling to massive matter fields. This result can be interpreted as a new anomaly, revealing unknown aspects of the well-known van Dam–Veltman–Zakharov discontinuity. [Copyright &y& Elsevier]

We investigate the possibility to disentangle the radions in the Randall–Sundrum scenario from Higgs boson at the next generation high energy e+e− linear colliders. Due to trace anomaly, the radion coupling (and in turn the branching ratio) to gluons is enhanced over the same for the Standard Model (SM) higgs. We study the radion φ production at electron–positron colliders, via the process e+e−→νν¯φ, and propose to investigate radion decay to a pair of gluons. At 500 GeV center of mass energy, our signal is not very promising. We find our results are encouraging for finding radion and differentiating it from higgs for center of mass energies of 1 TeV and above. [Copyright &y& Elsevier]

We argue that the ZZH coupling constitutes a simple probe of the nature of the scalar sector responsible for electroweak symmetry breaking. We demonstrate the efficacy of this measure through an analysis of four-dimensional models containing scalars in arbitrary representation of SU(2)×U(1), as well as extra-dimensional models with a non-factorizable geometry. A possible role for the tt¯H couplings is also discussed. [Copyright &y& Elsevier]

In the framework of quantum gravity propagating in large extra dimensions, the effects of virtual Kaluza–Klein gravitons on the imaginary part of the amplitude of the process e+e−→ff¯ are analyzed at the Z pole. Notably, the interference of the almost-continuous spectrum of the KK gravitons with the standard model resonant amplitude is finite and predictable in terms of the fundamental D-dimensional Planck scale MD. We find that, while the virtual-graviton effect on total cross sections vanishes at tree-level, both angular and polarization asymmetries are modified by terms whose relative effect is at most of order 10−4 for MD>1 TeV. Possible shifts in MZ, due to the changes in Breit–Wigner line shape are also discussed. [Copyright &y& Elsevier]

On-Line Analytical Processing (OLAP) refers to the technologies that allow users to efficiently retrieve data from the data warehouse for decision-support purposes. Data warehouses tend to be extremely large—it is quite possible for a data warehouse to be hundreds of gigabytes to terabytes in size. Queries tend to be complex and ad hoc, often requiring computationally expensive operations such as joins and aggregation. Given this, we are interested in developing strategies for improving query processing in data warehouses by exploring the applicability of parallel processing techniques. In particular, we exploit the natural partitionability of a star schema and render it even more efficient by applying Datalndexes—a storage structure that serves both as an index as well as data and lends itself naturally to vertical partitioning of the data. Dataindexes are derived from the various special purpose access mechanisms currently supported in commercial OLAP products. Specifically, we propose a declustering strategy which incorporates both task and data partitioning and present the Parallel Star Join (PSJ) Algorithm, which provides a means to perform a star join in parallel using efficient operations involving only rowsets and projection columns. We compare the performance of the PSJ Algorithm with two parallel query processing strategies. The first is a parallel join strategy utilizing the Bitmap Join Index (BJI), arguably the stateof-the-art OLAP join structure in use today. For the second strategy we choose a well-known parallel join algorithm, namely the pipelined hash algorithm. To assist in the performance comparison, we first develop a cost model of the disk access and transmission costs for all three approaches. Performance comparisons show that the DataIndex-based approach leads to dramatically lower disk access costs than the BJI, as well as the hybrid hash approaches, in both speedup and scaleup experiments, while the hash-based approach... [ABSTRACT FROM AUTHOR]

Examines the concurrency control (CC) of active database system (ADB). Identification of the transaction processing strategy of CC; Characteristics of ADB; Components of CC.

Proposes a protocol to enable secure data access in broadcast-based information delivery environment. Relation of push technology to broadcast network communication asymmetries; Role of encryption-based schemes; Role of single encoding multiple decoding (SEMD) in fulfilling security requirements; Comparison of performance of SEMD with that of other techniques.

Presents a study which explored the potential benefits of incorporating priority cognizance in conflict resolution for firm real-time database systems (RTDBS). Dynamic adjustment of serialization order on which optimistic concurrency control variant called OCC-APR is based; Priority cognizant concurrent control algorithm; Simulation model for RTBS evaluation; Performance analysis and discussion.

Databases have been mandated as the chosen platform to develop automated control systems for environments where the state of the system changes rapidly and actions need to be taken with timing constraints, for example, stock trading, air traffic control, network management, and process control to name a few. Input data in such systems come from sensors distributed throughout the physical environment being monitored. As the system state changes rapidly, the sensors report information fast and with high volumes. Control decisions in such systems are highly dependent on the accuracy and timeliness of such recorded sensor-reported data. In this paper we suggest ways to algorithmically maintain the accuracy and timeliness of sensor data by enforcing two properties termed recency and temporal consistency. Simultaneously, our algorithms also attempt to satisfy quality of service requirements on response times of queries submitted in such systems. The performance of these algorithms is validated through an extensive simulation. [ABSTRACT FROM AUTHOR]