A probe for the instantaneous measurement of surface temperature.

"Technical documentary report no.RTD-TDR-63-4015, AF Flight Dynamics Laboratory, Research and Technology Division, Air Force Systems Command, Wright Patterson Air Force Base, Ohio."

Quantitative determination of optical transmission through subwavelength slit arrays in Ag films: Role of surface wave interference and local coupling between adjacent slits

Measurement of the transmitted intensity from a coherent monomode light source through a series of subwavelength slit arrays in Ag films, with varying array pitch and number of slits, demonstrates enhancement (suppression) by factors of as much as 6 (9) when normalized to the transmission efficiency of an isolated slit. Pronounced minima in the transmitted intensity are observed at array pitches corresponding to lambda(SPP), 2 lambda(SPP), and 3 lambda(SPP), where lambda(SPP) is the wavelength of the surface plasmon polariton (SPP). The position of these minima arises from destructive interference between incident propagating waves and pi-phase-shifted SPP waves. Increasing the number of slits to four or more does not increase appreciably the per-slit transmission intensity. A simple interference model fits well the measured transmitted intensity profile.

Implications of specimen preparation and of surface contamination for the measurement of the grain boundary carbon concentration of steels using x-ray microanalysis in an UHVFESTEM

The purpose of the present investigation was to gain an understanding of the nature of the carbon contamination on the surface of standard steel transmission electron spectroscopy (TEM) specimens, the effect of exposure of a clean specimen to normal laboratory air, and the efficacy of plasma-cleaning treatments. This knowledge is a necessary prerequisite to the development of appropriate specimen preparation and/or specimen cleaning methods. X-ray photoelectron spectroscopy in combination with argon ion beam profiling was used to characterize the specimen surfaces of X65 steel and 316 stainless steel. The only clean carbon-free surface obtained was that during argon etching of the sample in the surface analysis chamber. Any exposure of a previously cleaned sample to laboratory air resulted in a rapid carbon (hydrocarbon) contamination of the sample surface and the development of surface oxidation, Plasma cleaning with subsequent exposure of the specimen to the laboratory air also resulted in a carbon-contaminated surface. This suggests that procedures of preparation of TEM specimens of steels outside an ultrahigh vacuum chamber are unlikely to result in the lowering of contamination rates on specimens to levels where measurements for carbon in the grain boundaries are possible. What is needed is a cleaning system as an integral part of the specimen insertion system into the field-emission scanning transmission electron microscope. This cleaning could be carried out by argon ion etching. Copyright (C) 2000 John Wiley & Sons, Ltd.

Different in Vivo Reactivity Profile in Health Care Workers and Patients with Spina Bifida to Internal and External Latex Glove Surface-Derived Allergen Extracts

BACKGROUND: Allergy to natural rubber latex is a well-recognized health problem, especially among health care workers and patients with spina bifida. Despite latex sensitization being acquired in health institutions in both health care workers and patients with spina bifida, differences in allergen sensitization profiles have been described between these two risk groups. OBJECTIVE: To investigate the in vivo reactivity of health care workers and patients with spina bifida to extracts of internal and external surfaces of latex gloves and also to specific extracts enriched in major allergens for these risk groups. METHODS: Gloves from different manufacturers were used for protein extraction, and salt precipitation and hydrophobic interaction chromatography (HIC) were applied to obtain the enriched latex extracts. The major latex allergens were quantified by an enzyme immunoassay. The extracts obtained were tested in 14 volunteers using skin prick tests (SPT). RESULTS: Latex glove extracts enriched in the hydrophobic allergens that are most often seen in patients with spina bifida were obtained by selective precipitation, whereas HIC produced extracts enriched in the hydrophilic allergens commonly found in health care workers. The health care workers had positive SPTs to glove extracts from internal surfaces and to the hydrophilic allergen-enriched extracts. By contrast, patients with spina bifida had larger skin reactions both to external glove extracts and to the extracts enriched with the hydrophobic major allergens for this risk group. Despite the protein concentration of these extracts being less than half the concentration of the commercial extract, the weal-and-flare reactions were of similar magnitude. CONCLUSION: Using novel latex extracts, our study showed a different in vivo reactivity pattern in health care workers and in patients with spina bifida to extracts of the internal and external surfaces of gloves, which suggests that sensitization may occur by different routes of exposure, and that this influences the allergen reactivity profiles of these risk groups

Direct in vivo measurement of glycine and the neurochemical profile in the rat medulla oblongata.

The medulla oblongata (MO) contains a high density of glycinergic synapses and a particularly high concentration of glycine. The aims of this study were to measure directly in vivo the neurochemical profile, including glycine, in MO using a spin-echo-based (1)H MRS sequence at TE?=?2.8 ms and to compare it with three other brain regions (cortex, striatum and hippocampus) in the rat. Glycine was quantified in MO at TE?=?2.8 ms with a Cramér-Rao lower bound (CRLB) of approximately 5%. As a result of the relatively low level of glycine in the other three regions, the measurement of glycine was performed at TE?=?20 ms, which provides a favorable J-modulation of overlapping myo-inositol resonance. The other 14 metabolites composing the neurochemical profile were quantified in vivo in MO with CRLBs below 25%. Absolute concentrations of metabolites in MO, such as glutamate, glutamine, ?-aminobutyrate, taurine and glycine, were in the range of previous in vitro quantifications in tissue extracts. Compared with the other regions, MO had a three-fold higher glycine concentration, and was characterised by reduced (p?<?0.001) concentrations of glutamate (-50?±?4%), glutamine (-54?±?3%) and taurine (-78?±?3%). This study suggests that the functional specialisation of distinct brain regions is reflected in the neurochemical profile.

Accuracy profile validation of a new method for carbon monoxide measurement in the human blood using headspace-gas chromatography-mass spectrometry (HS-GC-MS).

The aim of our study was to provide an innovative headspace-gas chromatography-mass spectrometry (HS-GC-MS) method applicable for the routine determination of blood CO concentration in forensic toxicology laboratories. The main drawback of the GC/MS methods discussed in literature for CO measurement is the absence of a specific CO internal standard necessary for performing quantification. Even if stable isotope of CO is commercially available in the gaseous state, it is essential to develop a safer method to limit the manipulation of gaseous CO and to precisely control the injected amount of CO for spiking and calibration. To avoid the manipulation of a stable isotope-labeled gas, we have chosen to generate in a vial in situ, an internal labeled standard gas ((13)CO) formed by the reaction of labeled formic acid formic acid (H(13)COOH) with sulfuric acid. As sulfuric acid can also be employed to liberate the CO reagent from whole blood, the procedure allows for the liberation of CO simultaneously with the generation of (13)CO. This method allows for precise measurement of blood CO concentrations from a small amount of blood (10 μL). Finally, this method was applied to measure the CO concentration of intoxicated human blood samples from autopsies.

The hardness profile as a tool to detect spurious stationary points in the potential energy surface

The energy and hardness profile for a series of inter and intramolecular conformational changes at several levels of calculation were computed. The hardness profiles were found to be calculated as the difference between the vertical ionization potential and electron affinity. The hardness profile shows the correct number of stationary points independently of the basis set and methodology used. It was found that the hardness profiles can be used to check the reliability of the energy profiles for those chemical system

Measurement of Pavement Surface Variations, July 1974

The measurement of pavement roughness has been the concern of highway engineers for more than 70 years. This roughness is referred to as "riding quality" by the traveling public. Pavement roughness evaluating devices have attempted to place either a graphical or numerical value on the public's riding comfort or discomfort. Early graphical roughness recorders had many different designs. In 1900 an instrument called the "Viagraph" was developed by an Irish engineer.' The "Viagraph" consisted of a twelve foot board with graphical recorder drawn over the pavement. The "Profilometer" built in Illinois in 1922 was much more impressive. ' The instrument's recorder was mounted on a frame supported by 32 bicycle wheels mounted in tandem. Many other variations of profilometers with recorders were built but most were difficult to handle and could not secure uniformly reproducible results. The Bureau of Public Roads (BPR) Road Roughness Indicator b u i l t in 1941 is the most widely used numerical roughness recorder.' The BPR Road Roughness Indicator consists of a trailer unit with carefully selected springs, means of dampening, and balanced wheel.

Accuracy profile validation of a new analytical method for propane measurement using headspace-gas chromatography-mass spectrometry

Propane can be responsible for several types of lethal intoxication and explosions. Quantifying it would be very helpful to determine in some cases the cause of death. Some gas chromatography-mass spectrometry (GC-MS) methods of propane measurements do already exist. The main drawback of these GC-MS methods described in the literature is the absence of a specific propane internal standard necessary for accurate quantitative analysis. The main outcome of the following study was to provide an innovative Headspace-GC-MS method (HS-GC-MS) applicable to the routine determination of propane concentration in forensic toxicology laboratories. To date, no stable isotope of propane is commercially available. The development of an in situ generation of standards is thus presented. An internal-labeled standard gas (C3DH7) is generated in situ by the stoichiometric formation of propane by the reaction of deuterated water (D2O) with Grignard reagent propylmagnesium chloride (C3H7MgCl). The method aims to use this internal standard to quantify propane concentrations and, therefore, to obtain precise measurements. Consequently, a complete validation with an accuracy profile according to two different guidelines, the French Society of Pharmaceutical Sciences and Techniques (SFSTP) and the Gesellschaft für toxikologische und Forensische Chemie (GTFCh), is presented.

Accuracy profile validation of a new analytical method for butane measurement using headspace-gas chromatography-mass spectrometry.

The aim of our study was to provide an innovative HS-GC/MS method applicable to the routine determination of butane concentration in forensic toxicology laboratories. The main drawback of the GC/MS methods discussed in literature concerning butane measurement was the absence of a specific butane internal standard necessary to perform quantification. Because no stable isotope of butane is commercially available, it is essential to develop a new approach by an in situ generation of standards. To avoid the manipulation of a stable isotope-labelled gas, we have chosen to generate in situ an internal labelled standard gas (C(4)H(9)D) following the basis of the stoichiometric formation of butane by the reaction of deuterated water (D(2)O) with Grignard reagent butylmagnesium chloride (C(4)H(9)MgCl). This method allows a precise measurement of butane concentration and therefore, a full validation by accuracy profile was presented.

Paper Surface Image Processing for Roughness Quality Measurement

Diplomityössä on käsitelty paperin pinnankarkeuden mittausta, joka on keskeisimpiä ongelmia paperimateriaalien tutkimuksessa. Paperiteollisuudessa käytettävät mittausmenetelmät sisältävät monia haittapuolia kuten esimerkiksi epätarkkuus ja yhteensopimattomuus sileiden papereiden mittauksissa, sekä suuret vaatimukset laboratorio-olosuhteille ja menetelmien hitaus. Työssä on tutkittu optiseen sirontaan perustuvia menetelmiä pinnankarkeuden määrittämisessä. Konenäköä ja kuvan-käsittelytekniikoita tutkittiin karkeilla paperipinnoilla. Tutkimuksessa käytetyt algoritmit on tehty Matlab® ohjelmalle. Saadut tulokset osoittavat mahdollisuuden pinnankarkeuden mittaamiseen kuvauksen avulla. Parhaimman tuloksen perinteisen ja kuvausmenetelmän välillä antoi fraktaaliulottuvuuteen perustuva menetelmä.

Measurement of a Structured Backflow in an Open Small Channel Induced by Surface-Tension Gradients

We present experiments in which the laterally confined flow of a surfactant film driven by controlled surface tension gradients causes the subtended liquid layer to self-organize into an inner upstream microduct surrounded by the downstream flow. The anomalous interfacial flow profiles and the concomitant backflow are a result of the feedback between two-dimensional and three-dimensional microfluidics realized during flow in open microchannels. Bulk and surface particle image velocimetry data combined with an interfacial hydrodynamics model explain the dependence of the observed phenomena on channel geometry.

Lidar measurement of surface melt for a temperate Alpine glacier at the seasonal and hourly scales

This study shows how a new generation of terrestrial laser scanners can be used to investigate glacier surface ablation and other elements of glacial hydrodynamics at exceptionally high spatial and temporal resolution. The study area is an Alpine valley glacier, Haut Glacier d'Arolla, Switzerland. Here we use an ultra-long-range lidar RIEGL VZ-6000 scanner, having a laser specifically designed for measurement of snow- and ice-cover surfaces. We focus on two timescales: seasonal and daily. Our results show that a near-infrared scanning laser system can provide high-precision elevation change and ablation data from long ranges, and over relatively large sections of the glacier surface. We use it to quantify spatial variations in the patterns of surface melt at the seasonal scale, as controlled by both aspect and differential debris cover. At the daily scale, we quantify the effects of ogive-related differences in ice surface debris content on spatial patterns of ablation. Daily scale measurements point to possible hydraulic jacking of the glacier associated with short-term water pressure rises. This latter demonstration shows that this type of lidar may be used to address subglacial hydrologic questions, in addition to motion and ablation measurements.

The hardness profile as a tool to detect spurious stationary points in the potential energy surface

The energy and hardness profile for a series of inter and intramolecular conformational changes at several levels of calculation were computed. The hardness profiles were found to be calculated as the difference between the vertical ionization potential and electron affinity. The hardness profile shows the correct number of stationary points independently of the basis set and methodology used. It was found that the hardness profiles can be used to check the reliability of the energy profiles for those chemical system