The Stark shift due to blackbody radiation (BBR) is the key factor limiting the performance of many atomic frequency standards, with the BBR environment inside the clock apparatus being difficult to characterize at a high level of precision. Here we demonstrate an in-vacuum radiation shield that furnishes a uniform, well-characterized BBR environment for the atoms in an ytterbium optical lattic...

In many signal processing applications, an appropriate measure to compare two signals plays a fundamental role in both implementing the algorithm and evaluating its performance. Several techniques have been introduced in literature as similarity measures. However, the existing measures are often either impractical for some applications or they have unsatisfactory results in some other applicati...

night work can have a significant impact on health, well-being, performance and occupational safety of workers. night workers often complain about the sleep disorder characterized by excessive sleepiness.  the aim of the study was to determine the level of sleepiness among night workers and investigate its relationship with oral temperature in a hot industry. this cross-sectional study involved...

We derive a new generalized imaging condition based on time shifts between source and receiver wavefields. This imaging condition contrasts with other imaging techniques requiring space shifts between the two wavefields. This imaging condition is applicable to both Kirchhoff and wave-equation migrations. The transformation allows us to generate common-image gathers presented as function of eith...

The MESUR solar array power model initially uses assumed values for many input variables. After landing the early surface variables such as array tilt and azimuth or early environmental variables such as array temperature can be corrected. Later environmental variables such as tau versus time, spectral shift, dust depotion, and UV darkening are dependent upon time, on-board science instruments,...

quantum dots of cds with hexagonal phase were prepared at relatively low temperature (60 oc) and short time by micro-emulsion (o/w) under ultrasound. this study was focused on the particle size distribution and the growth kinetics. the particle size distribution obtained from the optical absorption edge. it was relatively symmetrical with sonication time. in addition, an agreement was observed ...

The polymer liquid crystal PLC is the PET/0.6PHB copolymer; PET5poly~ethylene terephthalate!, PHB5r-hydroxybenzoic acid ~LC!: 0.65the mole fraction of PHB. This is a multiphase system with PHB-rich islands in a PET-rich matrix. Tensile creep compliance was measured isothermally from 20 °C to 160 °C in 10 °C intervals. Master curves were determined using the time–temperature superposition for 20...