Quantum phase transitions in optical lattices beyond Bogoliubov approximation

We study the quantum phase transition in optical lattices using ordinary Bose Hubbard Hamiltonian within two loop approximation in variational perturbation theory. We have shown that this approximation can reproduce superfluid Mott insulator transition in contrast to the simple Bogoliubov or Hartee - Fock - Popov approximations. The superfluid fraction and ground state energy per particle vs input parameters of the model are studied.Comment: Extended by including comarision with Gutzwiller approach. (To be published in PRA

The Effects Of Fructose-Induced Metabolic Syndrome On Renal Haemodynamic And Excretory Function In Rat

This study investigated whether the α1-adrenoceptor responsiveness of the renal vasculature was altered in a metabolic syndrome state due to high-fructose feeding. Male Sprague-Dawley rats were fed for 8 weeks with 20% fructose in the drinking water (F), while their controls received tap water (C) to drink ad libitum. Metabolic, functional and haemodynamic parameters were assessed weekly and at the end of the study. In another set of rats, F received either carvedilol (FCV) or losartan (FL) at (10mg/kg/day po) for 3 weeks starting from week 5 of the experiment. Another group of rats received tempol, a superoxide dismutase mimetic (FT) at (1 mmol/L) with 20% fructose in drinking water for 8 weeks. At the end of the treatment period, an intravenous insulin glucose tolerance test was performed to assess insulin sensitivity. Moreover, rats were pentobarbitone anaesthetized and the reductions in renal cortical blood flow induced by intrarenal administration of noradrenaline (NA), phenylephrine (PE), methoxamine (ME) and angiotensin II (Ang II) were determined in the presence and absence of 5-methylurapidil (5-MU), chloroethylclonidine (CEC) or BMY 7378. Data, mean±SEM were subjected to ANOVA with significance at P<0.05. At the end of the 8 weeks, F had higher systemic blood pressure, plasma glucose, triglycerides and insulin levels but significantly lower absolute and fractional sodium and potassium excretion as compared to C. The F rats expressed reduced (P<0.05) renal vascular responses to NA, PE, ME and Ang II compared to C. The response to Ang II was significantly attenuated by 5-MU, CEC and BMY 7378, and also following carvedilol, losartan or tempol treatments in the F and C rats

Reachability of Communicating Timed Processes

We study the reachability problem for communicating timed processes, both in discrete and dense time. Our model comprises automata with local timing constraints communicating over unbounded FIFO channels. Each automaton can only access its set of local clocks; all clocks evolve at the same rate. Our main contribution is a complete characterization of decidable and undecidable communication topologies, for both discrete and dense time. We also obtain complexity results, by showing that communicating timed processes are at least as hard as Petri nets; in the discrete time, we also show equivalence with Petri nets. Our results follow from mutual topology-preserving reductions between timed automata and (untimed) counter automata.Comment: Extended versio

Effect of Solid Particle Properties on Heat Transfer and Pressure Drop in Packed Duct

This work examines numerically the effects of particle size, particle thermal conductivity and inlet velocity of forced convection heat transfer in uniformly heated packed duct. Four packing material (Aluminum, Alumina, Glass and Nylon) with range of thermal conductivity (from200 W/m.K for Aluminum to 0.23 W/m.K for Nylon), four particle diameters (1, 3, 5 and 7 cm), inlet velocity ( 0.07, 0.19 and 0.32 m/s) and constant heat flux ( 1000, 2000 and 3000 W/ m 2) were investigated. Results showed that heat transfer (average Nusselt number Nuav) increased with increasing packing conductivity; inlet velocity and heat flux, but decreased with increasing particle size.Also, Aluminum average Nusselt number is about (0.85,2.2 and 3.1 times) than Alumina, glass and Nylon respectively. From optimization between heat transfer and pressure drop through packed duct, it is found thatfinest ratio (Nuav / ?p) equal to (19.12) at (Dp = 7 cm, inlet velocity = 0.07 m/ s and 3000 W/m2 heat flux) with Aluminum as packing material

An exploration into senior managers' effectiveness: the case of the Muscat Municipality, Oman

Since the eighties there has been a concerted effort to reform the public sector in order to, amongst other things, improve their performance and service delivery to the public. Large scale and capital intensive projects are required, especially within Oman a developing country, for ensuring development and improved service for the citizen. The planning, implementation and maintenance of these initiatives rests on public sector institutions. The role and effectiveness of senior managers play a significant part in the overall success of their organisations and the development of their nations. The main concern of this research is to explore and identifying the behavioural influences which contribute to the increased effectiveness of the senior managers of the Muscat Municipality, Oman. This research utilises a combination of qualitative and quantitative methodologies. In addressing the leadership effectiveness in Oman, it utilises and contextualises Analoui’s (2002) model of eight parameters for effectiveness as a basis to explore the awareness, perceptions, skills, organisational criteria, motivation, degree of demands and constraints, choices and opportunities, and dominant leadership philosophy for effectiveness. Based on the above, suggestions have been made to improve the content and context of senior managers’ work to increase their effectiveness in Oman. This first time study contributes to the present knowledge and understanding of the subject by contextualising the concept of ‘Managerial Effectiveness’ in Oman’s public sector. It concludes that better understanding of the subject requires attention being paid to the identified parameters of senior managers’ effectiveness. Moreover, consideration should be given to the influences and impact of the above parameters on personal, organisational and external contexts in Oman. These will lead to improved performance and organisational effectiveness as the whol

Forward Analysis and Model Checking for Trace Bounded WSTS

We investigate a subclass of well-structured transition systems (WSTS), the bounded---in the sense of Ginsburg and Spanier (Trans. AMS 1964)---complete deterministic ones, which we claim provide an adequate basis for the study of forward analyses as developed by Finkel and Goubault-Larrecq (Logic. Meth. Comput. Sci. 2012). Indeed, we prove that, unlike other conditions considered previously for the termination of forward analysis, boundedness is decidable. Boundedness turns out to be a valuable restriction for WSTS verification, as we show that it further allows to decide all $\omega$-regular properties on the set of infinite traces of the system

Hybrid Method for Digits Recognition using Fixed-Frame Scores and Derived Pitch

This paper presents a procedure of frame normalization based on the traditional dynamic time warping (DTW) using the LPC coefficients. The redefined method is called as the DTW frame-fixing method (DTW-FF), it works by normalizing the word frames of the input against the reference frames. The enthusiasm to this study is due to neural network limitation that entails a fix number of input nodes for when processing multiple inputs in parallel. Due to this problem, this research is initiated to reduce the amount of computation and complexity in a neural network by reducing the number of inputs into the network. In this study, dynamic warping process is used, in which local distance scores of the warping path are fixed and collected so that their scores are of equal number of frames. Also studied in this paper is the consideration of pitch as a contributing feature to the speech recognition. Results showed a good performance and improvement when using pitch along with DTW-FF feature. The convergence rate between using the steepest gradient descent is also compared to another method namely conjugate gradient method. Convergence rate is also improved when conjugate gradient method is introduced in the back-propagation algorithm