Measurements on the spectral energy distribution of direct solar radiation, made in July 1953, at Sacramento P eak, New Mexico, altitude 9,200 feet are described . Spectral data a re given for wavelengths extending from 299 to 535 millimicrons for ai r masses 0, 1.0,2.0, and 3.0. A determination of atmospheric transmittance as a function of wavelength results in calculated total amounts of ozon...

We report temporal shaping of few-cycle terahertz pulses, using a slit in a conductive screen as a high-pass filter. The filter's cutoff frequency was tuned by changing the width of the slit; the slope of the cutoff transition was altered by changing the thickness of the screen. We measured the transmission function of the filters, using large-aperture photoconducting antennas to create and det...

InSb nanowire arrays have been fabricated by direct current electrodeposition inside the nanochannels of anodic alumina membranes without subsequent annealing. After Au contacts were patterned to the nanowires using electron beam lithography, photoresponse studies were conducted. Absorbance peaks were also recorded from free suspending nanowires. A significant response was observed when the wir...

In liquid crystal cells with photoconductive polysN-vinlyl carbazole) polymer layers, an external dc field can be completely screened by surface charge layers that develop at the liquid crystal– polymer interface. Under spatially modulated illumination, surface charge layers can be discharged in bright areas and lead to reorientation and spatially modulated Freedericksz transition. As a result,...

background and purpose: many workers are exposed to workplace hazards. many occupational diseases are preventable by personal protective devices (ppds). though many workers do not use ppds or their protection by ppds is not sufficient. this study was designed to assess the quality of ppds usage among industrial workers. materials and methods: in a cross-sectional study, 648 workers from four ma...

We describe the use of mixing linearly chirped optical pulses in biased photoconductors to generate tunable narrow-band terahertz (THz) radiation with enhanced spectral brightness. The increase in conversion efficiency from optical to THz radiation at a given THz frequency arises from the improved saturation characteristics of the photoconductor for chirped-pulse mixing compared with the usual ...

background: intrauterine device (iud) is an effective and long term method of contraception that can be used without continued effort by the user to prevent pregnancy perfectly. pain during iud insertion is one of the obstacles to properly using the device. thus, using different methods of analgesia and anesthesia to alleviate this pain has been studied by many researchers. this review article ...