An upper bound for Cubicity in terms of Boxicity

AbstractAn axis-parallel b-dimensional box is a Cartesian product R1×R2×⋯×Rb where each Ri (for 1≤i≤b) is a closed interval of the form [ai,bi] on the real line. The boxicity of any graph G, box(G) is the minimum positive integer b such that G can be represented as the intersection graph of axis-parallel b-dimensional boxes. A b-dimensional cube is a Cartesian product R1×R2×⋯×Rb, where each Ri (for 1≤i≤b) is a closed interval of the form [ai,ai+1] on the real line. When the boxes are restricted to be axis-parallel cubes in b-dimension, the minimum dimension b required to represent the graph is called the cubicity of the graph (denoted by cub(G)). In this paper we prove that cub(G)≤⌈log2n⌉box(G), where n is the number of vertices in the graph. We also show that this upper bound is tight.Some immediate consequences of the above result are listed below: 1.Planar graphs have cubicity at most 3⌈log2n⌉.2.Outer planar graphs have cubicity at most 2⌈log2n⌉.3.Any graph of treewidth tw has cubicity at most (tw+2)⌈log2n⌉. Thus, chordal graphs have cubicity at most (ω+1)⌈log2n⌉ and circular arc graphs have cubicity at most (2ω+1)⌈log2n⌉, where ω is the clique number.The above upper bounds are tight, but for small constant factors

Light Assisted Collisional Loss in a 85/87^{85/87}Rb Ultracold Optical Trap

We have studied hetero- and homonuclear excited state/ground state collisions by loading both $^{85}$Rb and $^{87}$Rb into a far off resonant trap (FORT). Because of the relatively weak confinement of the FORT, we expect the hyperfine structure of the different isotopes to play a crucial role in the collision rates. This dependence on hyperfine structure allows us to measure collisions associated with long range interatomic potentials of different structure: such as long and short ranged; or such as purely attractive, purely repulsive, or mixed attractive and repulsive. We observe significantly different loss rates for different excited state potentials. Additionally, we observe that some collisional channels' loss rates are saturated at our operating intensities (~15 mW/cm$^{2}$). These losses are important limitations in loading dual isotope optical traps.Comment: about 8 pages, 5 figure

A STUDY ON EFFECT OF INDOLE AS A SUBSTITUENT ON A KETO-ENOL TAUTOMER: A SYNTHETIC APPROACH ON β-DIKETONE

Objective: The existence of keto-enol tautomerism in β-diketones can typically study by a choice of analytical technique. The position of the keto-enol equilibrium depends on a number of factors like solvent, temperature, and substituents. Here an attempt was made to examine the effect of indole, a heterocyclic moiety with the moderately high polar surface area to examine its effect on ketonisation of β-diketone.Methods: The β-diketone studied and synthesized is a structural analog of magical drug curcumin. The structural influence of indole on ketonisation of β-diketone is studied to give a hypothesis on factors contributing towards ketonisation. This work involves the synthesis of 6-(1H-Indol-3-yl)-hex-5ene-2, 4-dione and the study on the single crystal structure of indole-3-carboxaldehyde, major functional component to result in the reaction. The tautomer was studied for its ability to bind with tetrahydrofolate reductase enzyme using Discovery Studio 3.5 version to differentiate the pharmacological significance of conformations.Results: The single crystal XRD structure of this compound was deposited in Cambridge crystallographic data center bearing CCDC No.1536311. The structural characterization of synthesized ligand was carried out by using IR, Mass, 1H NMR spectroscopic techniques. The docking study reveals that keto isomer found to exhibit more inhibition of the enzyme tetrahydrofolate reductase hence more pharmacologically active.Conclusion: The experimental evidence proves that indole substitution shifted the keto-enol equilibrium towards keto form of 6-(1H-Indol-3-yl)-hex-5ene-2, 4-dione

Top-Gated Chemical Vapor Deposited Mos2 Field-Effect Transistors On Si3N4 Substrates

We report the electrical characteristics of chemical vapor deposited (CVD) monolayer molybdenum disulfide (MoS2) top-gated field-effect transistors (FETs) on silicon nitride (Si3N4) substrates. We show that Si3N4 substrates offer comparable electrical performance to thermally grown SiO2 substrates for MoS2 FETs, offering an attractive passivating substrate for transition-metal dichalcogenides (TMD) with a smooth surface morphology. Single-crystal MoS2 grains are grown via vapor transport process using solid precursors directly on low pressure CVD Si3N4, eliminating the need for transfer processes which degrade electrical performance. Monolayer top-gated MoS2 FETs with Al2O3 gate dielectric on Si3N4 achieve a room temperature mobility of 24 cm(2)/V s with I-on/I-off current ratios exceeding 10(7). Using HfO2 as a gate dielectric, monolayer top-gated CVD MoS2 FETs on Si3N4 achieve current densities of 55 mu A/mu m and a transconductance of 6.12 mu S/mu m at V-tg of -5V and V-ds of 2V. We observe an increase in mobility at lower temperatures, indicating phonon scattering may dominate over charged impurity scattering in our devices. Our results show that Si3N4 is an attractive alternative to thermally grown SiO2 substrate for TMD FETs. (C) 2015 AIP Publishing LLC.STTR programNSF NASCENT ERCArmy Research Office under STTR W911NF-14-P-0030Microelectronics Research Cente

Information Processing view of Electricity Demand Response Systems: A Comparative Study Between India and Australia

Background: In recent years, demand response (DR) has gained increased attention from utilities, regulators, and market aggregators to meet the growing demands of electricity. The key aspect of a successful DR program is the effective processing of data and information to gain critical insights. This study aims to identify information processing needs and capacity that interact to improve energy DR effectiveness. To this end, organizational information processing theory (OIPT) is employed to understand the role of Information Systems (IS) resources in achieving desired DR program performance. This study also investigates how information processing for DR systems differ between developing (India) and developed (Australia) countries. Method: This work adopts a case study methodology to propose a theoretical framework using OIPT for information processing in DR systems. The study further employs a comparative case data analyses between Australian and Indian DR initiatives. Results: Our cross case analysis identifies variables of value creation in designing DR programs - pricing structure for demand side participation, renewable integration at supply side, reforms in the regulatory instruments, and emergent technology. This research posits that the degree of information processing capacity mediates the influence of information processing needs on energy DR effectiveness. Further, we develop five propositions on the interaction between task based information processing needs and capacity, and their influence on DR effectiveness. Conclusions: The study generates insights on the role of IS resources that can help stakeholders in the electricity value chain to take informed and intelligent decisions for improved performance of DR programs

Development of a Friction Rig and Experimental Results

The development of a friction rig, which is integrated into a milling machine for testing the frictional characteristics of various types of materials and specimen shapes are described. This is followed by the experimental technique used to measure the friction coefficient for different experimental conditions. The results obtained indicate the frictional coefficient obtained changes with the specimen type, contact area and lubrication condition. The results obtained are also compared to available published results. The discussions and conclusions related to the development and experimental results are finally presented

Structural Studies of Cu(II) & Ni(II) Complexes with a Chiral Schiff Base

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Broodstock development, breeding and seed production of selected marine food fishes and ornamental fishes

In recent years the contribution of marine finfish in the global aquaculture production has been steadily increasing. Marine food fishes like groupers, snappers, siganids, pompano, cobia and ornamental fishes have great potential for domestic and export trade