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Subwavelength optical lattices induced by position-dependent dark states

Subwavelength optical lattices induced by position-dependent dark states

A method for the generation of subwavelength optical lattices based on multilevel dark states is proposed. The dark state is formed by a suitable combination of standing wave light fields, leading to position-dependent populations of the ground states.
Inversion of three-stage stress–strain relation for stainless steel in tension and compression

Inversion of three-stage stress–strain relation for stainless steel in tension and compression

Presented in this paper is a new stress–strain relation for stainless steel alloys that provides the stress as an explicit function of the strain. The relation is an approximate inversion of a recently proposed three-stage stress–strain relation based on a modified Ramberg–Osgood equation. The three-stage relation is a much more accurate formulation than the previous two-stage formulations and is applicable to both tensile as well as compressive stresses.
Prevalence of common phobias and their socio-demographic correlates in children and adolescents in a traditional developing society

Prevalence of common phobias and their socio-demographic correlates in children and adolescents in a traditional developing society

Objective: The aim of this study was to identify the most common phobias in children and adolescents and to determine the prevalence, age distribution, and socio-demographic correlates of phobias. Method: This was a prospective cross-sectional study conducted at public and private schools from July 2009 to February 2009. The questionnaire included socio-demographic information, extra-curricular activities and hobbies, behaviour at home and various phobic fears and it was distributed among children aged 6 to 18 years.
Multiple-module high-gain high-voltage dc-dc transformers for offshore wind energy systems

Multiple-module high-gain high-voltage dc-dc transformers for offshore wind energy systems

Renewable energy sources, such as offshore wind farms, require high voltage gains in order to interface with power transmission networks. These conversions are normally made using bulky, complex, and costly transformers and high-voltage ac-dc converters with unnecessary bidirectional power flow capability.
Neuronal ceroid lipofuscinosis in qatar: report of a novel mutation in ceroid-lipofuscinosis, neuronal 5 in the arab population

Neuronal ceroid lipofuscinosis in qatar: report of a novel mutation in ceroid-lipofuscinosis, neuronal 5 in the arab population

This study sought to genetically define the first family diagnosed with neuronal ceroid lipofuscinosis from Qatar. Onset was in late infancy (3 years), and sequencing in the affected children revealed a novel homozygous c.613C>T change in exon 3 of ceroid-lipofuscinosis, neuronal 5, corresponding to a missense mutation of a conserved amino acid, p.Pro205Ser.
Risk analysis of flare flame-out condition in a gas process facility

Risk analysis of flare flame-out condition in a gas process facility

Flaring is a common method of disposal of flammable waste gases in the downstream industries. Flare flame out (flame lift-off or blow-outs) often occurs causing toxic vapors to discharge. The toxic gases released may have hazardous effects on the surrounding environment.
Tumor associated mesenchymal stem cells protects ovarian cancer cells from hyperthermia through CXCL12

Tumor associated mesenchymal stem cells protects ovarian cancer cells from hyperthermia through CXCL12

Abstract: Hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promise in treatment of ovarian carcinosis. Despite its efficiency for the treatment of peritoneal carcinosis from digestive tract neoplasia, it has failed to demonstrate significant benefit in ovarian cancers. It is therefore essential to understand the mechanism underlying resistance to HIPEC in ovarian cancers.
A thermo-viscoelastic-viscoplastic-viscodamage constitutive model for asphaltic materials

A thermo-viscoelastic-viscoplastic-viscodamage constitutive model for asphaltic materials

A temperature-dependent viscodamage model is proposed and coupled to the temperature-dependent Schapery s nonlinear viscoelasticity and the temperature-dependent Perzyna s viscoplasticity constitutive model presented in Abu Al-Rub et al (2009) and Huang et al (in press) in order to model the nonlinear constitutive behavior of asphalt mixes The thermo-viscodamage model is formulated to be a function of temperature total effective strain and the damage driving force which is expressed in terms of the stress invariants of the effective stress in the undamaged configuration This expression for the damage force allows for the distinction between the influence of compression and extension loading conditions on damage nucleation and growth A systematic procedure for obtaining the thermo-viscodamage model parameters using creep test data at different stress levels and different temperatures is presented The recursive-iterative and radial return algorithms are used for the numerical implementation of the nonlinear viscoelasticity and viscoplasticity models respectively whereas the viscodamage model is implemented using the effective (undamaged) configuration concept Numerical algorithms are imple mented in the well-known finite element code Abaqus via the user material subroutine UMAT The model is then calibrated and verified by comparing the model predictions with experimental data that include creep-recovery creep and uniaxial constant strain rate tests over a range of temperatures stress levels and strain rates It is shown that the presented constitutive model is capable of predicting the nonlinear behavior of asphaltic mixes under different loading conditions (C) 2010 Elsevier Ltd All rights reserved.
Urinary Cell Levels of mRNA for OX40, OX40L, PD-1, PD-L1, or PD-L2 and Acute Rejection of Human Renal Allografts

Urinary Cell Levels of mRNA for OX40, OX40L, PD-1, PD-L1, or PD-L2 and Acute Rejection of Human Renal Allografts

Background. The positive costimulatory proteins OX40 and OX40L and negative regulatory proteins programmed death (PD)-1, PD ligand 1, and PD ligand 2 have emerged as significant regulators of acute rejection in experimental transplantation models. Methods. We obtained 21 urine specimens from 21 renal allograft recipients with graft dysfunction and biopsy-confirmed acute rejection and 25 specimens from 25 recipients with stable graft function and normal biopsy results (stable). 
A robust approach for clock offset estimation in wireless sensor networks

A robust approach for clock offset estimation in wireless sensor networks

The maximum likelihood estimators (MLEs) for the clock phase offset assuming a two-way message exchange mechanism between the nodes of a wireless sensor network were recently derived assuming Gaussian and exponential network delays. However, the MLE performs poorly in the presence of non-Gaussian or nonexponential network delay distributions. Currently, there is a need to develop clock synchronization algorithms that are robust to the distribution of network delays. This paper proposes a clock offset estimator based on the composite particle filter (CPF) to cope with the possible asymmetries and non-Gaussianity of the network delay distributions. Also, a variant of the CPF approach based on the bootstrap sampling (BS) is shown to exhibit good performance in the presence of reduced number of observations. Computer simulations illustrate that the basic CPF and its BS-based variant present superior performance than MLE under general random network delay distributions such as asymmetric Gaussian, exponential, Gamma, Weibull as well as various mixtures
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DeSIGN: Guided Practice for Sign Language

DeSIGN: Guided Practice for Sign Language

Children learn and practice their vocabulary through interaction with parents and friends as well as through formal instruction at school. However, for deaf children, sign language is the main...
Calcium channels determine how life begins, and ends
Calcium channels determine how life begins, and ends

Calcium channels determine how life begins, and ends

Ongoing work at Weill Cornell Medical College in Qatar (WCMC-Q) is investigating how intracellular calcium (Ca2+) signaling pathways are involved in the very beginning of life as they prepare the...
Taking gas-to-liquid technology to the next level
Taking gas-to-liquid technology to the next level

Taking gas-to-liquid technology to the next level

In the 1920s, two German scientists—Franz Fischer and Hans Tropsch—developed revolutionary chemical reactions that could transform gas into liquid. These reactions proved particularly...
Researchers build the case for wind and wave studies in Qatar
Researchers build the case for wind and wave studies in Qatar

Researchers build the case for wind and wave studies in Qatar

For the first time, fine detail about the wind and wave conditions around the coast of Qatar has been recorded. By arranging the most sophisticated equipment available on the edge of a 500-meter...
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