Self-assembled monolayers (SAMs), prepared by reaction of terminal n-alkynes (HC≡C(CH2)nCH3, n = 5, 7, 9, and 11) with Au(111) at 60 °C were characterized using scanning tunneling microscopy (STM), infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS), and contact angles of water. In contrast to previous spectroscopic studies of this type of SAMs, these com...

We investigate the sensitivity limit of absorption spectroscopy. An experiment is described in which the decrease in transmitted light intensity that is due to absorption by a single, electromagnetically confined atomic ion is observed.

Highlights of interesting astrophysical discoveries are reviewed in the context of high resolution X-ray spectroscopy made possible with Chandra and XMM-Newton , and its relevance to atomic physics calculations and measurements is discussed. These spectra have shown that the overlap between astrophysics and atomic physics is stronger than ever, as discoveries of new X-ray lines and edge structu...

Laboratory measurements of water vapor absorption using cavity ring-down spectroscopy revealed a broad absorption at 405 nm with a quadratic dependence on water monomer concentration, a similar absorption with a linear component at 532 nm, and only linear absorption at 570 nm in the vicinity of water monomer peaks. D2O ab5 sorption is weaker and linear at 405 nm. Van’t Hoff plots constructed at...

We describe the performance of a colorimetric reagent kit (Diagnostic Systems Laboratories, Inc., Webster, TX 77598) for measuring calcium directly in urine, serum, and ultrafiltered serum, and compare the results with those obtained with atomic absorption spectrophotometry. The CV for within-run precision was 2.8 and 2.1% for urine and whole serum, respectively (n = 10 each). Between-run preci...

The primary objective of this paper is to enhance the water-vapor-adsorption capacity of multiwall-carbon-nanotube (MWCNT) from nitrogen gas by grafting sulfonic acid groups and doping palladium nanoparticles into the adsorbent. MWCNT has been selected to be modified because of having homogeneous adsorption energy compared to silica gel. As a result, it is capable of creating isotherm having sh...

Ultra-cold alkaline earth atoms show great promise as future optical frequency standards and as key components in optical atomic clocks. Atomic strontium is an exciting candidate for a future standard as the level structure provides multiple narrow clock transitions as well as means for efficient laser cooling to μK temperatures. A variety of measurement techniques are currently being explored ...

Laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) is capable of metal imaging by acquiring local spatial information. However, the preparation an appropriate standard for quantitative analysis difficult because matrices between and sample should match, homogeneity concentration in required. Hence, aim this study was to establish a highly mercury method that utilizes LA-ICP...

abstract background and objective: there have been concerns over possible association between mercury and neurodevelopmental outcomes in infants. in this study we aimed to determine whether blood levels of mercury are above safe values in iranian infants or not. materials and methods:  a total of 85 infants (0, 2, 4 and 6 months old) were enrolled in this study. all of them received vaccines ac...