DNA barcoding was adopted in our laboratory for the identification of tobacco (Nicotiana spp.) in moassel samples seized from "hookah bars". As recommended by the CBOL Plant Working Group, we used a 2-locus combination of rbcL and matK as the plant barcode. As previously reported rbcL routinely produced high quality bi-directional reads but had a lower discriminating power than matK. It was much more difficult obtaining high quality bi-directional reads with matK possibly because of poor sample quality. DNA barcoding successfully identified tobacco in over 60 commercial tobacco moassel products. On the other hand, negative results (no amplification) or the identification of non-tobacco species were obtained from herbal moassel products. Our study clearly demonstrates the practical utility of DNA barcoding beyond taxonomy. PMID:22578874

Aim The study aimed to provide information about the concurrent and discriminant validation of the Scale of Evaluation of Reading Competence by the Teacher (EACOL), which is composed of 27 dichotomous items concerning reading aloud (17 items) and reading silently (10 items). Samples Three samples were used in this validation study. The first was composed of 335 students with an average age of 9.75 years (SD = 1.2) from Belo Horizonte (Minas Gerais State), Brazil, where the full spectrum of reading ability was assessed. The second two samples were from São Paulo city (São Paulo State), Brazil, where only children with reading difficulties were recruited. The first São Paulo sample was labeled “SP-screening” and had n = 617, with a mean age of 9.8 years (SD = 1.0), and the other sample was labeled “SP-trial” and had n = 235, with a mean age of 9.15 years (SD = 0.05). Methods Results were obtained from a latent class analysis LCA, in which two latent groups were obtained as solutions, and were correlated with direct reading measures. Also, students’ scores on the Wechsler Intelligence Scale and on the Strengths and Difficulties Questionnaire tested the discriminant validation. Results Latent groups of readers underlying the EACOL predicted all direct reading measures, while the same latent groups showed no association with behavior and intelligence assessments, giving concurrent and discriminant validity to EACOL, respectively. Conclusion EACOL is a reliable screening tool which can be used by a wide range of professionals for assessing reading skills. PMID:14190250

The solid phase microextraction (SPME) device with the polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber was used as a passive sampler for ambient ozone. Both O-2,3,4,5,6-(pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) and 1,2-di-(4-pyridyl)ethylene (DPE) were loaded onto the fiber before sampling. The SPME fiber assembly was then inserted into a PTFE tubing as a passive sampler. Known concentrations of ozone around the ambient ground level were generated by a calibrated ozone generator. Laboratory validations of the SPME passive sampler with the direct-reading ozone monitor were performed side-by-side in an exposure chamber at 25 deg. C. After exposures, pyriden-4-aldehyde was formed due to the reaction between DPE and ozone. Further on-fiber derivatizations between pyriden-4-aldehyde and PFBHA were followed and the derivatives, oximes, were then determined by portable gas chromatography with electron capture detector. The experimental sampling rate of the SPME ozone passive sampler was found to be 1.10 x 10{sup -4} cm{sup 3} s{sup -1} with detection limit of 58.8 {mu}g m{sup -3} h{sup -1}. Field validations with both SPME device and the direct-reading ozone monitor were also performed. The correlations between the results from both methods were found to be consistent with r = 0.9837. Compared with other methods, the current designed sampler provides a convenient and sensitive tool for the exposure assessments of ozone.

A field study was conducted to evaluate the effectiveness of several auxiliary air cleaning services in reducing components of environmental tobacco smoke (ETS) within a designated smoking lounge and ambient areas in an office suite. Monitoring was performed for the ETS components nicotine, respirable particulate and carbon monoxide. Nicotine and RSP samples were collected in a smoking lounge for two eight-hour periods for each of the following conditions: (1) no smoking in the office suite with no air cleaning devices operating; (2) smoking in the smoking lounge with no clean air devices operating; and (3) smoking in the smoking lounge with one of four air cleaning devices operating. Eight-hour general area and personal samples were also collected to determine levels of nicotine and RSP in ambient, non-smoking areas. Continuous monitoring, with one minute averaging, was performed for carbon monoxide using a direct reading air quality monitor.

A method of analyzing a sample material by liquid chromatography is described wherein the sample is dissolved in a carrier fluid to form a mobile phase. The mobile phase is electrochemically treated to selectively remove electroactive materials therein or to change chromatographic characteristics of said materials therein prior to passing the mobile phase to a chromatography column.

The use of urinary hexane diamine (HDA) as a biomarker to assess human respiratory exposure to hexamethylene diisocyanate (HDI) aerosol was evaluated. Twenty-three auto body shop workers were exposed to HDI biuret aerosol for two hours using a closed exposure apparatus. HDI exposures were quantified using both a direct-reading instrument and a treated-filter method. Urine samples collected at baseline, immediately post exposure, and every four to five hours for up to 20 hours were analyzed for HDA using gas chromatography and mass spectrometry. Mean urinary HDA (microg/g creatinine) sharply increased from the baseline value of 0.7 to 18.1 immediately post exposure and decreased rapidly to 4.7, 1.9 and 1.1, respectively, at 4, 9, and 18 hours post exposure. Considerable individual variability was found. Urinary HDA can assess acute respiratory exposure to HDI aerosol, but may have limited use as a biomarker of exposure in the workplace. PMID:15473079

In order to investigate the difference in cortical activations between reading letter strings in the normal direction and the reverse direction, an fMRI study was conducted. In this study, the cortical activations elicited by Japanese letter string reading and Chinese letter string reading were investigated. The subjects performed the normal direction reading task (read letter strings from left to right), and the reverse direction reading task (read letter strings from right to left). According to the experimental results, the activated brain regions during the normal and the reverse direction reading tasks were compared. It was found that visuospatial transformation was involved in the reverse direction reading task, while this function was not significant during the normal direction reading task. Furthermore, we found that there was no significant difference in cortical activation between Japanese and Chinese letter string readings.   

This paper presents a mobile-carrier choice modeling framework to analyze customer preference and understand customer choice behavior in the mobile phone market. Due to severe competitive conditions, there are few differences between the mobile phone services provided by mobile-carriers. We propose a new mobile-carrier choice modeling that takes into account incentive factors and restrictive factors as decision-making factors. A Web survey was carried out to obtain the sample data for this model. We show the model estimated from the survey data to analyze mobile-carrier choice behavior.   

Wireless sensor networks (WSNs) play a vital role in environmental monitoring. Advances in mobile sensors offer new opportunities to improve phenomenon predictions by adapting spatial sampling to local variability. Two issues are relevant: which location should be sampled and which mobile sensor should move to do it? This paper proposes a form of adaptive sampling by mobile sensors according to the expected value of information (EVoI) and mobility constraints. EVoI allows decisions to be made about the location to observe. It minimises the expected costs of wrong predictions about a phenomenon using a spatially aggregated EVoI criterion. Mobility constraints allow decisions to be made about which sensor to move. A cost-distance criterion is used to minimise unwanted effects of sensor mobil...

A series of GaAs1-ySby epilayers are grown on GaAs substrates under different growth conditions. Different antimony compositions of samples with beryllium doping are obtained. A non-equilibrium thermodynamics model is used to calibrate and fit the Sb composition. Activation energy of 0.37eV for the dissociation process of Sb4 molecules is obtained. Carrier mobility and concentration of samples are influenced by the Sb composition. Quasi-qualitative analysis of mobility is used to explain the relations among Sb composition, carrier mobility and concentration. High resolution x-ray diffraction (HRXRD) rocking curves and Hall effects measurements are used to determine the crystal quality, carrier mobility and concentration.

How is the link between learner and technology made in mobile learning? What is the value of the concept of "affordances"? And how does research articulating this concept act to position mobile devices as "technologies for learning"? This literature review used both unstructured and structured search samples of published research on mobile learning to critically evaluate the prevalence and influence of the concept of the affordances of mobile technologies. Actor-network theory is drawn on as a theoretical lens through which to critically consider how this concept is articulated, and in particular to explore the way it positions and controls mobile devices as technologies for learning. Parallels in contemporary accounts of mobile learning are drawn with classifications of previous discourses around the introduction of computers into schools. An alternative agenda for mobile learning research is suggested with a focus on authentic and informal contexts rather than controlled experiments.

The National Institute for Occupational Safety and Health conducted an initial, task-based comparative assessment to determine the potential for release of carbon nanofibers (CNFs) during dry material handling, wet cutting, grinding, and sanding (by machine and hand) of plastic composite material containing CNFs. Using a combination of direct-reading instruments and filter-based air sampling methods for airborne mass and transmission electron microscopy (TEM), concentrations were measured and characterized near sources of particle generation, in the breathing zone of the workers, and in the general work area. Tasks such as surface grinding of composite material and manually transferring dry CNFs produced substantial increases in particle number concentration (range = 20,000-490,000 1-cm(-3)). Concomitant increases in mass concentration were also associated with most tasks. Nearly 90% of all samples examined via TEM indicated that releases of CNFs do occur and that the potential for exposure exists. These findings also indicate that improperly designed, maintained, or installed engineering controls may not be completely effective in controlling releases. Unprotected skin exposure to CNFs was noted in two instances and indicated the need for educating workers on the need for personal protective equipment. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a PDF file containing information on materials, evaluated processes, personal protective equipment, and existing ventilation/engineering controls.]. PMID:22545869

The investigation of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS) having the reduced graphene oxide (RGO), denoted RGO-doped PEDOT:PSS shows that conductivity of RGO-doped PEDOT:PSS samples is 27 times higher than that of PEDOT:PSS at 300 K. The improved electrical conductivity is considered to mainly come from the mobility enhancement. The carrier mobility in RGO-doped PEDOT:PSS samples exhibits unexpectedly strong temperature dependence, implying the domination of tunneling (hopping) at low (high) temperatures. An exhibition of high mobility of RGO-doped PEDOT:PSS samples is attributed to the increased spacing between molecules.

The use of scanning electrochemical microscopy, a high-resolution chemical imaging technique, to probe the distribution and mobility of solutes in articular cartilage is described. In this application, a mobile ultramicroelectrode is positioned close ( approximately 1 microm) to the cartilage sample...

Mobile platform development has lately become a technological war zone with extremely dynamic and fluid movement, especially in the smart phone and tablet market space. This Synthesis lecture is a guide to the latest developments of the key mobile platforms that are shaping the mobile platform industry. The book covers the three currently dominant native platforms -- iOS, Android and Windows Phone -- along with the device-agnostic HTML5 mobile web platform. The lecture also covers location-based services (LBS) which can be considered as a platform in its own right. The lecture utilizes a sampl

Background: The population of older adults with intellectual disabilities is growing, creating new challenges for individuals, families and service providers. Although there has been increased research into the ageing process for adults with intellectual disabilities, there is little focused research investigating physical mobility. Materials and Methods: A proxy-response telephone survey was conducted to establish the prevalence and severity of mobility limitations among adults with intellectual disabilities, aged 45 years and over, using validated instruments to quantify mobility in a representative population-based sample. Results: Surveys were completed for 128 people. Mobility limitations were common, but the prevalence varied depending on the definition of mobility limitation. The prevalence of limitations was greater among females than males, but no clear age trend was seen. Conclusions: The common nature of mobility limitations among the growing population of older adults with intellectual disabilities has implications for service providers and policy-makers.

Volatile organic compounds (VOC) in indoor air are an important and inescapable component of everyone's exposure to complex mixtures of organics. A tiered approach is outlined for the cost-effective monitoring of VOC. At the coarsest level, a hand-held, direct-reading photoionization detector (PID) is suitable for rapid screening, or following temporal changes if the concentrations are high enough. Readings can be expressed as benzene, or some other VOC, equivalent units. Moderately sophisticated measurements can be made in near real time using a portable GC with a PID. Several of the more abundant hydrocarbons, such as benzene, toluene, and straight and branched chain alkanes are usually measurable in indoor air samples. Passive monitoring devices based on Tenax GC sorbent show promise for the future. The sophisticated method of choice for the collection and definitive analysis of VOC is sorbent trapping on Tenax GC and carbonaceous resins with subsequent thermal desorption and analysis by selected-ion mass spectroscopy. Measurements made inside homes in East Tennessee show that overall levels of VOC are usually in the range of a few tenths to a few mg/m/sup 3/. Gasoline fumes are a major component of the VOC, especially where the house has an attached garage. Chlorinated alkanes and alkenes comprise a smaller fraction of the total VOC, usually being present at sum concentrations of a tenth of a mg/m/sup 3/ or less. In all types of measurement it was verified that indoor concentrations of VOC exceed those found outdoors.

Fast autonomous mobility, autonomous target sampling, and terrain relative navigation promise to have a significant impact on the utility, efficiency, cost, and reliability of future robotic Mars surface missions.

This report brings together the results of a re-examination of zooplankton samples from the Mobile OTEC site (29/sup 0/N-88/sup 0/W) in the northern Gulf of Mexico for macrozooplankton larger than 15 mm.

Advantages associated with hollow-stem auger drilling include rig mobility and versatility; the utility of the hollow stems for collection of representative samples of formation materials and for installation of monitoring wells; relatively fast advancement of the borehole in unc...

Abstract in english Acid drainage results from exposition of sulfides to the atmosphere. Arsenopyrite is a sulfide that releases arsenic (As) to the environment when oxidized. This work evaluated the As mobility in six sulfidic geomaterials from gold mining areas in Minas Gerais State, Brazil. Grained samples ((more) generation, dissolving Fe oxihydroxides and releasing As. Presence of carbonates decreased oxidation rates and As release. On the other hand, lime added to a partially oxidized sample increased As mobilization.

The carrier transport mechanism of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS) having ZnO nanoparticles, denoted ZnO-doped PEDOT:PSS, is investigated. Conductivity proportional to ZnO doping was observed at 300 K. The improved electrical conductivity is considered to mainly come from the mobility enhancement. The carrier mobility in ZnO-doped PEDOT:PSS samples exhibits unexpectedly strong temperature dependence, implying the domination of tunneling in the whole range of temperatures. An exhibition of high mobility of ZnO-doped PEDOT:PSS samples is attributed to a combined effect of the weak electron-phonon couplings and changes in the chemical structure of PEDOT:PSS.

Energy losses in insulators can be determined by examining the mobility of free electrons, particularly when high AC voltages are used. An increase in the mobility of free electrons leads to an increase in insulator conductivity and a reduction of dielectric strength. This study presented an experimental estimation of the average mobility change of free electronic carriers for model solid-liquid insulators during dielectric aging. Samples of solid insulators were electrically stressed using high AC voltage through a tip-plane setup in an insulating oil environment. A mathematical model was then derived using results from the experiment. The average mobility change of sample model was calculated in order to determine the relationship between the average mobility variation and the imposed electric field. Values for the electric field at the tip-plane electrodes were evaluated using hyperbolic tip analysis. Results of the study showed that the actual value of the average mobility value of free electrons for the industrial bakelite samples of 1 mm thickness in an insulating oil environment was 287.5 cm{sup 2}/V s to 353.8 cm{sup 2}/Vs. It was concluded that the average mobility value of free electron change increases exponentially in relation to the imposed electric field, which may in turn indicate the impact of the ionization effect. 10 refs., 1 tab., 4 figs.

The aim of this study was to characterise personal exposures to dust, acid vapours, and gases among workers in a Norwegian nitrate fertiliser production plant, as part of an ongoing epidemiological study. In total, 178 inhalable and 179 thoracic aerosol mass fraction samples were collected from randomly chosen workers (N = 141) from three compound fertiliser departments (A, B and C), a calcium nitrate fertiliser production department, nitric acid- and ammonia-production departments, and a shipping department. The overall median inhalable and thoracic aerosol mass concentrations were generally low (1.1 mg m(-3) (min-max: phosphate rock towards the final product of fertilisers. Overall, the arithmetic mean of water-soluble Ca in the thoracic mass fraction was 51% (min-max: 1-100). A total of 169 personal samples were analysed for HNO(3) vapour and HF. The highest median concentration of HNO(3) (0.63 mg m(-3)) was in the compound fertiliser departments B, and all measurements but four of the HF concentrations were below the LOD of 190 ?g m(-3). Exposures to NH(3), CO and NO(2) were measured using direct-reading electrochemical sensors and the time weighted overall averages were all below the LODs of the respective sensors, NH(3) 2 ppm; CO 2 ppm; and NO(2) 0.2 ppm, but some short-term peaks were detected. Even though our results indicate that the workers may experience peak exposure episodes when performing job tasks such as cleaning or maintenance work, the overall air concentrations are well below what is considered to cause known health risks. PMID:22777595

Based on theory regarding mobile communication in general, this essay relates the experiences of migrant workers from both rural and urban areas in Fuzhou, who used mobile phones to stay in contact with the Beijing 2008 Olympic Games, to how these contacts supported and encouraged migrant workers to persist in gathering Olympic Games information. In other words, does the relationship between demographics and knowledge about the Beijing 2008 Olympic Games differ according to the use of mobile phones among migrant workers? Results indicate that television became the primary source of Olympic Games news for migrant workers, but actually with few advantages as the respondents considered the mobile phone as their second source of information. Given the higher than average mobile media penetration rate among the sample of migrant workers and their information expectations, we cannot ignore the mobile phone’s impact as a channel for information and public services. This essay’s focus is also on how the government,the official press and service providers (China Mobile and China Unicom) appreciated the mobile phone as a means of spreading the Olympic Games’ influence, making it possible for a large majority of people to enjoy the Olympic Games, and popularizing knowledge.

Aim: Our aim was to describe how the probability of walking, wheeled mobility, and assisted mobility changes with environmental setting and age in children and adolescents with cerebral palsy (CP). Method: The parents of a population-based sample of 642 children and adolescents (360 males, 282 females; age range 16mo-21y) reported their children's mobility at home, school, and outdoors at 6- or 12-month intervals a mean of 5.2 times. Generalized mixed-effects analyses were used to model the probabilities. Results: By age 3 years, children with motor function classified as level I according to the Gross Motor Function Classification System (GMFCS) walked in all three settings. Children/adolescents classified as level V used assisted mobility, with a small number using wheeled mobility. In the case of children classified as GMFCS level II, the probability of walking varied with the environmental setting, which, at age 18, is outdoors 90% of the time. Among children classified as GMFCS level III, the probability of walking was highest at age 9 at school (68%), and at age 18 was approximately 50% in all three settings. Among children/adolescents rated as GMFCS level IV, the probability of wheeled mobility increased with age and, at age 18, 57% of mobility took place outdoors. Interpretation: The results provide evidence that age and environmental setting influence method of mobility of children/adolescents with CP. The method that is preferred in one setting may not be preferred in another setting or at another age. (Contains 4 figures.)

An ion mobility spectrometer is described which is equipped with two non-radioactive ion sources, namely an atmospheric pressure photoionization and a corona discharge ionization source. The two sources cannot only run individually but are additionally capable of operating simultaneously. For photoionization, a UV lamp was mounted parallel to the axis of the ion mobility cell. The corona discharge electrode was mounted perpendicular to the UV radiation. The total ion current from the photoionization source was verified as a function of lamp current, sample flow rate, and drift field. Simultaneous operation of the two ionization sources was investigated by recording ion mobility spectra of selected samples. The design allows one to observe peaks from either the corona discharge or photoionization individually or simultaneously. This makes it possible to accurately compare peaks in the ion mobility spectra from each individual source. Finally, the instrument's capability for discriminating two peaks appearing in approximately identical drift times using each individual ionization source is demonstrated. PMID:22841099

In this article we show that usage of a mobile phone, i.e. daily series of number of calls made by a customer, exhibits long memory. We use a sample of 4502 postpaid users from a Polish mobile operator and study their two-year billing history. We estimate Hurst exponent by nine estimators: aggregated variance method, differencing the variance, absolute values of the aggregated series, Higuchi’s method, residuals of regression, the R/S method, periodogram method, modified periodogram method and Whittle estimator. We also analyze empirically relations between estimators. Long memory implies an inertial effect in clients’ behavior which may be used by mobile operators to accelerate usage and gain additional profit.

Hydrophilic interaction chromatography (HILIC) is valuable alternative to reversed-phase liquid chromatography separations of polar, weakly acidic or basic samples. In principle, this separation mode can be characterized as normal-phase chromatography on polar columns in aqueous-organic mobile phases rich in organic solvents (usually acetonitrile). Highly organic HILIC mobile phases usually enhance ionization in the electrospray ion source of a mass spectrometer, in comparison to mobile phases with higher concentrations of water generally used in reversed-phase (RP) LC separations of polar or ionic compounds, which is another reason for increasing popularity of this technique. Various columns can be used in the HILIC mode for separations of peptides, proteins, oligosaccharides, drugs, meta...

A ?? modulator using a frequency modulation intermediate signal was demonstrated using a resonant tunneling logic gate called a monostable bistable transition logic element (MOBILE). This ?? modulator is based on the nature of an FM signal and suitable for high-speed operation. Experiments using an InP-based MOBILE demonstrate good noise shaping characteristics. Moreover, the operation with a higher FM carrier frequency than the sampling frequency was demonstrated, showing equally good noise shaping performance. This makes the design of the voltage-controlled oscillator, which is a key component of the FM ?? modulator, much easier. Consequently, an FM ?? modulator using MOBILE is promising for high-resolution, wide-band analog-to-digital converters (ADCs).

The purpose of this study is to (1) identify addiction symptoms that are uniquely associated with mobile phone use among adolescents in Hong Kong; (2) examine how demographics and psychological attributes (such as leisure boredom, sensation seeking, and self-esteem) of individuals are related to the addiction symptoms; and (3) explore how these attributes, mobile phone addiction symptoms, and social capital can predict improper use of the mobile phone. Data were gathered from a probability sample of 402 teenagers and young adults aged 14-20 in Hong Kong. Exploratory factor analysis identified four addiction symptoms: “losing control and receiving complaints,” “anxiety and craving,” “withdrawal/escape,” and “productivity loss.” Results...

This report describes an innovative technology, laser ablation-inductively couple plasma-mass spectrometry (LA-ICP-MS), operated in a mobile laboratory, to rapidly detect thorium 230 activity levels in soil samples. This technology was demonstrated on-site during November 1993 at the Gunnison, Colorado, UMTRA project site in support of their remediation effort. The LA-ICP-MS sampling and analysis technique was chosen because of the capability for rapid analysis, approximately three samples per hour, with minimal sample preparation.

Unsaturated zone salt reservoirs are potentially mobilized by increased groundwater recharge as semiarid lands are cultivated. This study explores the amounts of pore water sulfate and fluoride relative to chloride in unsaturated zone profiles, evaluates their sources, estimates mobilization due to past land use change, and assesses the impacts on groundwater quality. Inventories of water-extractable chloride, sulfate, and fluoride were determined from borehole samples of soils and sediments collected beneath natural ecosystems (N = 4), nonirrigated (\\

A series of GaAs/InGaAs quantum wells with a silicon delta-doped layer in the top barrier was investigated by Shubnikov-de Haas measurements as a function of the illumination time of the samples. During the illumination process strong modifications of the electronic density and the quantum mobility of each occupied subband were observed. Based on self-consistent calculations, the dominant mechanism which caused the changes in the subband quantum mobilities with illumination was elucidated.

A mobile laboratory for research and development studies of ventilation requirements and energy utilization in residential and commercial buildings was designed and fabricated. The mobile laboratory contains sampling, calibrating, and monitoring systems to measure the concentration of CO, CO/sub 2/, NO, NO/sub 2/, NO/sub x/, O/sub 3/, and SO/sub 2/, and infiltration rates can be monitored continuously using a tracer gas system in which the tracer is injected into the room, mixed with room air, and monitored.

However, it is the best reproduction available from the original .... size ranges sampled by the two types of sample collector. Fig. 2: ..... fugacity to determine the complexes responsible for the transport, and ... chloride activites exceed 1. d) Under certain conditions phosPhAte ... mobile, resulting In the bleaching of wall rocks.

Thermoelectric properties of camphorsulfonic acid (CSA) doped conducting polyaniline with different structures have been studied. The sample with special submicron-fibre structure exhibited 20 times higher thermoelectric power factor at 300 K than the sample with general grain structure, which could be ascribed to its higher carrier mobility caused by its higher order of chain packing.   

This paper reviews research methods used to understand the user experience of mobile technology. The paper presents an improvement of the Experience Sampling Method and case studies supporting its design. The paper concludes with an agenda of future work for improving research in this field. Keywords: Research methods, topology, case study, contrasting graph, Experience Sampling Method

Full text: An epitaxial layers of GaAs on semi-insulating substrate have been grown by MBE at temperature {approx}200 deg C (normally {approx} 600 deg C ), known as low temperature grown GaAs (LT GaAs). LT GaAs contains {approx} 1% excess arsenic, and after annealing, the excess arsenic forms arsenic precipitates. To investigate annealing effect on mobility and resistivity, the sample was cut into several pieces and annealed at different temperatures, ranging from 200 deg C to 600 deg C. The resistivity and Hall mobility of the as grown and annealed samples were measured using Hall-van der Pauw methods at different temperatures. The Hall-van der Pauw measurement system was designed to suit the high-resistance measurement. The resistivity is dramatically increased as the annealing temperature is increased and the samples become highly resistive after annealed at 600 deg C. The as grown sample has very low mobility, however, after it is annealed the mobility is gradually increased. The results of theoretical calculation of the mobility in annealed sample are also presented. The calculation was carried out using the Monte Carlo method, based on the `internal Schottky barrier` model. We used a novel approach to overcome the problem of inhomogeneity of internal electric field due to the presence of arsenic precipitates

The fundamental principle of applying ferro-graphic particle analysis to study the wear of diesel engines in break-in process is introduced. The direct reading ferro-graph experiment results of a type of vehicle diesel engine in break-in are analyzed, and new viewpoints about ferro-graphic theory on machine break-in are developed. (au)

I consider the low energy limit of Little Higgs models. The method consists in eliminating the heavy fields using their classical equations of motion in the infinite mass limit. After the elimination of the heavy degrees of freedom one can directly read off deviations from the precision electroweak ...

This study identified and quantified the main chemical compounds--the substances responsible for the disagreeable odors--and the bioaerosols emitted during the biological treatment of paper mill effluents. It also identified the characteristics of the process that effects the generation or diffusion of these substances. All treatment stages were evaluated. Measuring sites were located as closely as possible to the potential emission sources. Measurements were taken in the summer in 11 paper mills during a 2- to 3-day period in each mill. Chemical compounds were evaluated by direct-reading instruments; bioaerosols were sampled by impaction and counted. Sulfur compounds, emitted into the air when the effluent or the sludge is stirred, had the highest concentrations; their presence was attributable to such things as kraft-type paper pulp. Next in concentration were the carbon and nitrogen oxides, ammonia, and some organic acids, produced by the action of microorganisms. These acids are found mainly in the sludge environment. Terpenes, which come from wood, are present at various locations in paper mills. Odor perception thresholds for most of these substances are much lower than those established to protect the health of workers. Significant concentrations of total bacteria, total molds, and endotoxins were measured at several sites. Gram-negative bacteria were high at only one site, whereas the mold Aspergillus fumigatus was occasionally present at low concentration. No actinomycetes bacteria were detected. The highest concentrations were measured where there was water or dust aerosolization. Emissions are therefore controlled by controlling the operations that lead to the dispersion of water and particles into the air. PMID:11434439

ABSTRACT: BACKGROUND: In Australia telephone surveys have been the method of choice for ongoing jurisdictional population health surveys. Although it was estimated in 2011 that nearly 20% of the Australian population were mobile-only phone users, the inclusion of mobile phone numbers into these existing landline population health surveys has not occurred. This paper describes the methods used for the inclusion of mobile phone numbers into an existing ongoing landline random digit dialling (RDD) health survey in an Australian state, the New South Wales Population Health Survey (NSWPHS). This paper also compares the call outcomes, costs and the representativeness of the resultant sample to that of the previous landline sample. METHODS: After examining several mobile phone pilot studies conducted in Australia and possible sample designs (screening dual-frame and overlapping dual-frame), mobile phone numbers were included into the NSWPHS using an overlapping dual-frame design. Data collection was consistent, where possible, with the previous years' landline RDD phone surveys and between frames. Survey operational data for the frames were compared and combined. Demographic information from the interview data for mobile-only phone users, both, and total were compared to the landline frame using chi2 tests. Demographic information for each frame, landline and the mobile-only (equivalent to a screening dual frame design), and the frames combined (with appropriate overlap adjustment) were compared to the NSW demographic profile from the 2011 census using chi2 tests. RESULTS: In the first quarter of 2012, 3395 interviews were completed with 2171 respondents (63.9%) from the landline frame (17.6% landline only) and 1224 (36.1%) from the mobile frame (25.8% mobile only). Overall combined response, contact and cooperation rates were 33.1%, 65.1% and 72.2% respectively. As expected from previous research, the demographic profile of the mobile-only phone respondents differed most (more that were young, males, Aboriginal and Torres Strait Islanders, overseas born and single) compared to the landline frame responders. The profile of respondents from the two frames combined, with overlap adjustment, was most similar to the latest New South Wales (NSW) population profile. CONCLUSIONS: The inclusion of the mobile phone numbers, through an overlapping dual-frame design, did not impact negatively on response rates or data collection, and although costing more the design was still cost-effective because of the additional interviews that were conducted with young people, Aboriginal and Torres Strait Islanders and people who were born overseas resulting in a more representative overall sample. PMID:23173849

Metal contents of waste mobile phones represent a major environmental risk, especially considering the adoption of inappropriate management options in developing countries including open burning and disposal into surface water bodies. In this study the metal contents of mobile phone printed wiring board (PWB) samples were assessed. Sixty-two waste mobile phones of 15 brands were collected, dismantled, and their PWB samples were analyzed for Cu, Pb, Ag and Cd. The metal concentrations in the samples varied widely between and within brands. Among these metals, Cu and Pb were found to be at very high concentrations. The range (mean ± SD) of Cu and Pb concentrations were 94.1-532 g kg-1 (250 ± 92.3 g kg-1) and 7.0-46.2 g kg-1 (20.1 ± 8.4 g kg-1), respectively. All Cu and Pb conc...

Social mobility is the movement of individuals, families and groups from one social position to another. Researchers indicate that people with psychiatric disabilities tend to come from lower socioeconomic status groups, and that the causal relationship between lower socioeconomic status and mental illness occurs through social mobility process. The purpose of this study was to examine the occupational social mobility process of a sample of self-identified psychiatrically disabled individuals who have been active members of the labor force for most of their adult lives. A total of 200 participants were recruited from the customers of a One-Stop Career Center in Gloucester County, New Jersey. The social mobility pattern of persons with psychiatric disabilities was compared to that of persons without psychiatric disabilities (n = 100 for each group). That is, the social selection and the social causation hypotheses were applied to the social mobility patterns of people with psychiatric disabilities. It was revealed that the social class distribution for fathers of people with psychiatric disabilities was not different from that of people without psychiatric disabilities and also there was no significant social mobility difference between the two groups. These findings do not support the social causation and the social selection hypotheses. Specifically, the findings demonstrate that occupational capabilities and skills of people with psychiatric disabilities have been stabilized and are similar to those of people without psychiatric disabilities. Furthermore, these results may dispute several biases and prejudices with regard to social mobility process of persons with psychiatric disabilities.   

(-)-Ephedrine-molecularly imprinted polymers (MIPs) have been successfully used as stationary phases in supercritical fluid chromatography for the separation of (+/-)-ephedrine enantiomers. This approach combines the simple preparation and predictable elution order of MIP stationary phases with the superior mobile phase diffusivity and low viscosity of supercritical fluid mobile phases. The optimised mobile phase comprised supercritical carbon dioxide with a modifier consisting of MeOH/isopropylamine/H2O 93:5:2 (v/v/v). In many cases, better resolution separations were observed compared to when liquid mobile phases were used, and better separations achieved at high sample loads, although interestingly the MIPs which work best in SFC are different from the MIPs that work best in HPLC with a...

This paper examines Municipal Wireless (MW) deployments in the United States. In particular, the interest is in understanding how discourse has worked to mobilize widespread support for MW networks. We explore how local governments discursively deploy the language of social movements to create a shared understanding of the networking needs of communities. Through the process of"framing" local governments assign meaning to the MW networks in ways intended to mobilize support anddemobilize opposition. The mobilizing potential of a frame varies and is dependent on its centrality and cultural resonance. We examine the framing efforts of MW networks by using a sample of Request for Proposals for community wireless networks, semi-structured interviews and local media sources. Prominent values that are central to a majority of the projects and others that are culturally specific are identified and analyzed for their mobilizing potency.

Low- and high-field magnetotransport measurements on two 30 nm {delta}-doped InSb/AlInSb quantum wells (QWs) with different doping densities are reported. The QW two-dimensional electron gas (2DEG) carrier densities and mobilities were extracted by analysis of the Hall and quantum Hall data, mobility spectra and Shubnikov-de Haas oscillations. 2DEG channel mobilities of up to 324 000 cm{sup 2} V{sup -1} s{sup -1} (T=2 K) and 44 000 cm{sup 2} V{sup -1} s{sup -1} (T=300 K) are extracted. Carrier densities and mobilities for transport parallel to the 2DEG layer are also deduced where observable. The importance of thermally generated carriers in the lower AlInSb barrier material and the role of transport within the {delta}-doping plane is considered and the total carrier population as a function of temperature of the two samples is deduced, which is in excellent agreement with experimental observation.

The sampling device includes a box provided with a cavity, closed by a cover, P groups of pipes passing through the surface of the box; the box comprises a mobile piece filling the cavity, pierced from part to part by a pipe which can make the two pipes of any group communicate, while closing the ones of the P-1 other groups. This device can be applied to radioactive fluid sampling. The invention concerns also the sampling process.

This study is a compilation of results obtained during the cleanout of deposition equipment such as chemical vapor deposition or physical vapor deposition The measurement campaigns aimed to evaluate the potential exposure to nanoaerosols in the occupational environment and were conducted in the workspace. The characterization of aerosols includes measurements of the concentration using condensation particle counters and measurements of the size distribution using fast mobility particle sizer, scanning mobility particle sizer, and electrical low pressure impactor (ELPI). Particles were sampled using collection membranes placed on the ELPIs stages. The samples were analyzed with an SEM?EDS to provide information including size, shape, agglomeration state, and the chemical composition of the ...

This study aims to examine students' acceptance of mobile technology usage for learning. A questionnaire designed with five open-ended questions was distributed to 20 students from the Faculty of Industrial Art and Design Technology of Unisel (Universiti Industri Selangor), Malaysia. Results construes that students were not keen on m-learning (mobile learning), as they did not rely greatly on the mobile phone in assessing their learning materials such as lectures and lab sessions. They were more familiar with studio-based and face-to-face learning approach instead of m-learning and were not receptive to this new idea of learning using mobile technology, even though they always used the mobile device features. The limitations in the mobile device feature, costs and its usability become the prominent factors that hinder the students from fully accomplishing their m-learning exercises. They were willing to explore the idea of using mobile technology for learning, especially in a studio-based setting. They did not see any improvement of knowledge from the perspective of the learning process know-how to the show-how on mobile technology usage for learning. They could not relate to any learning connection between mobile technology and studio-based learning, even though in the first part of the case study, the results have shown positive attitude and acceptance on the study made on a sample lesson of form, space and gestalt theory in the graphic design subject. Students also obtained analogous experiences on small size keypads, screen resolutions, and navigation which could be the major problematic factors to them and thus, affected their m-learning process as it was unfriendly to use and the device was prone to damage. They have yet to accept that the concept of mobility in learning is applicable to the learning process, apart from utilising a mobile device for casual usage. However, this limitation does not restrict the students from exploring this new learning environment in the future, since they were willing to increase their learning exposure using mobile device. (Contains 2 figures.)

This study aims to evaluate the performance of different leaching schemes with respect to the mobilization of antimony and arsenic from polluted samples collected at different sites in Mansfeld District, Germany. Besides the elution by water the leaching by artificial acidic rain and by two different schemes of sequential extraction were employed for estimation of the mobilization of antimony and arsenic. The samples were characterized by X-ray fluorescence analysis for their total concentration of metalloids, metals and main constituents. It was found that both antimony and arsenic show little mobilization with de-ionized water as well as artificial acidic rain in single step batch procedures (? 0.13% of the total content). Although the percentage leached is very low, the concentrations i...

Oral Diseases (2012) 18, 786-792 Objective:- In the last two decades, the use of mobile phones has increased enormously all over the world. The controversy regarding whether radiofrequency (RF) fields exert effects upon biological systems is a concern for the general population. An evaluation is made of DNA damage and cytokinetic defects, proliferative potential, and cell death because of RF radiation emitted by mobile phones in healthy young users. Study design:- This cohort study was carried out in 50 Caucasian mobile phone users. We collected two cell samples from each subject (a total of 100 cell samples), corresponding to the right and left cheek mucosa, respectively. Case histories and personal information were assessed, including age, gender, body height and weight, history of cance...

Water, methanol, tetrahydrofuran and their mixtures were used as mobile phases and the relationship between retention volumes of polyethylene glycol (PEG) and the composition of the mobile phases on a hydrophilic polymethacrylate gel column was investigated. The column packed with this polymer gel could be used with both polar and non-polar organic solvents as well as aqueous solvents. Retention volume of PEG having the same molecular weight changed with changing the composition of the mobile phase. The change of molecular size of PEG with changing the composition of the mobile phase was small compared to the difference in retention volume, and PEG samples were considered to be separated mainly by size exclusion, secondary effects being superimposed. In order to calculate molecular weight averages of PEG, the adequate selection of the mobile phase which minimizes the peak width of PEG is important and the recommended combination of PEG and the mobile phase with the column used here for PEG are PEG - water, PEG higher than 1000 molecular weight - THF/methanol (50/50) or THF.

Single molecule microscopic and spectroscopic methods are employed to probe the mobility and physical entrapment of dye molecules in dry and solvent-loaded poly(dimethylsiloxane) (PDMS) films. PDMS films of approximately 220 nm thickness are prepared by spin casting dilute solutions of Sylgard 184 onto glass coverslips, followed by low temperature curing. A perylene diimide dye (BPPDI) is used to probe diffusion and molecule-matrix interactions. Two classes of dye-loaded samples are investigated: (i) those incorporating dye dispersed throughout the films ("in film" samples) and (ii) those in which the dye is restricted primarily to the PDMS surface ("on film" samples). Experiments are performed under dry nitrogen and at various levels of isopropyl alcohol (IPA) loading from the vapor phase. A PDMS-coated quartz-crystal microbalance is employed to monitor solvent loading and drying of the PDMS and to ensure equilibrium conditions are achieved. Single molecules are shown to be predominantly immobile under dry conditions and mostly mobile under IPA-saturated conditions. Quantitative methods for counting the fluorescent spots produced by immobile single molecules in optical images of the samples demonstrate that the population of mobile molecules increases nonlinearly with IPA loading. Even under IPA saturated conditions, the population of fixed molecules is found to be greater than zero and is greatest for "in film" samples. Fluorescence correlation spectroscopy is used to measure the apparent diffusion coefficient for the mobile molecules, yielding a mean value of D = 1.4(+/-0.4) x 10(-8) cm(2)/s that is virtually independent of IPA loading and sample class. It is concluded that a nonzero population of dye molecules is physically entrapped within the PDMS matrix under all conditions. The increase in the population of mobile molecules under high IPA conditions is attributed to the filling of film micropores with solvent, rather than by incorporation of molecularly dispersed solvent into the PDMS. PMID:19006339

Problems of the diagnostics of a mobile charge in dielectric films and quasi-neutral peaks in the I?V characteristics of the structure are analyzed. A relationship between the measured currents and the currents in the sample during the diagnostics of inhomogeneous dielectrics with anisotropic permittivity is presented.

crystals creates hole defects, which may be highly mobile and lead to color center ... Three more control samples (CaF2-2, LiF-1, and LiF-3) were kept in the ...... Structural and Compositional. Changes on Alkali Halide Surfaces,". Surf. Sci. 219 ...

Anodic bonding of silicon to glass always involves heating the glass and device to high temperatures so that cations become mobile in the electric field. We present a simple way of bonding thin silicon samples to borosilicate glass by means of heating from the glass side while locally cooling heat-s...

The effects of Ficoll and cell application pH on red blood cell electrophoretic mobility and focusing pH were investigated by focusing cells in a density gradient stabilized column. Sample loading, cell dispersion, column conductivity, resolution of separation, and the effect of Ampholines were examined.

A sample of (1) children whose parents had been proximally exposed (i.e., less than 2,000 m from the hypocenter) at the time of the atomic bombings of Hiroshima and Nagasaki and (2) a suitable comparison group have been examined for the occurrence of mutations altering the electrophoretic mobility o...

We present in this paper a sample quality control approach for the case using a mobile phone’s camera as a fingerprint sensor for fingerprint recognition. Our approach directly estimates the maximum ridge frequency orientation by the amplitude-frequency features of the Fast Fourier Transform and tak...

Dislocation mobility is studied by low frequency internal friction in undoped InSb between 0.1 and 0.98 Tm. Samples characterized by a mainly screw dislocations substructure generated by low temperature (403 K) deformation, reveal two high amplitude peaks located at 570 and 725 K. The 570 K-peak sym...

Natural organic acids may play an important role in influencing the mobility of toxic contaminants in the environment. The mobilization of arsenic (As) and heavy metals from an oxidized Pb-Zn mine tailings sample in the presence of three low-molecular-weight organic acids, aspartic acid, cysteine, and succinic acid, was investigated at a mass ratio of 10 mg organic additive/g mine tailings in this study. The effect of pH was also evaluated. The mine tailings sample, containing elevated levels of As (2,180 mg/kg), copper (Cu, 1,100 mg/kg), lead (Pb, 12,860 mg/kg), and zinc (Zn, 5,075 mg/kg), was collected from Bathurst, New Brunswick, Canada. It was found that the organic additives inhibited As and heavy metal mobilization under acidic conditions (at pH 3 or 5), but enhanced it under neutral to alkaline conditions (at pH above 7) through forming aqueous organic complexes. At pH 11, As, Cu, Pb, and Zn were mobilized mostly by the organic additives, 45, 46, 1,660, and 128 mg/kg by aspartic acid, 31, 28, 1,040, and 112 mg/kg by succinic acid, and 53, 38, 2,020, and 150 mg/kg by cysteine, respectively, whereas those by distilled water were 6, 16, 260, and 52 mg/kg, respectively. It was also found that the mobilization of As and the heavy metals was closely correlated, and both were closely correlated to Fe mobilization. Arsenic mobilization by the three LMWOAs was found to be consistent with the order of the stability of Fe-, Cu-, Pb-, and Zn-organic ligand complexes. The organic acids might be used potentially in the natural attenuation and remediation of As and heavy metal-contaminated sites. PMID:22648854

An ion mobility spectrometer that can easily be installed as an intermediate component between a commercial triple-quadrupole mass spectrometer and its original atmospheric pressure ionization (API) sources was developed. The curtain gas from the mass spectrometer is also used as the ion mobility spectrometer drift gas. The design of the ion mobility spectrometer allows reasonably fast installation (about 1 h), and thus the ion mobility spectrometer can be considered as an accessory of the mass spectrometer. The ion mobility spectrometer module can also be used as an independently operated device when equipped with a Faraday cup detector. The drift tube of the ion mobility spectrometer module consists of inlet, desolvation, drift, and extraction regions. The desolvation, drift and extraction regions are separated by ion gates. The inlet region has the shape of a stainless steel cup equipped with a small orifice. Ion mobility spectrometer drift gas is introduced through a curtain gas line from an original flange of the mass spectrometer. After passing through the drift tube, the drift gas serves as a curtain gas for the ion-sampling orifice of the ion mobility spectrometer before entering the ion source. Counterflow of the drift gas improves evaporation of the solvent from the electrosprayed sample. Drift gas is pumped away from the ion source through the original exhaust orifice of the ion source. Initial characterization of the ion mobility spectrometer device includes determination of resolving power values for a selected set of test compounds, separation of a simple mixture, and comparison of the sensitivity of the electrospray ionization ion mobility spectrometry/mass spectrometry (ESI-IMS/MS) mode with that of the ESI-MS mode. A resolving power of 80 was measured for 2,6-di-tert-butylpyridine in a 333 V/cm drift field at room temperature and with a 0.2 ms ion gate opening time. The resolving power was shown to be dependent on drift gas flow rate for all studied ion gate opening times. Resolving power improved as the drift gas flow increased, e.g. at a 0.5 ms gate opening time, a resolving power of 31 was obtained with a 0.65 L/min flow rate and 47 with a 1.3 L/min flow rate for tetrabutylammonium iodide. The measured limits of detection with ESI-MS and with ESI-IMS/MS modes were similar, demonstrating that signal losses in the IMS device are minimal when it is operated in a continuous flow mode. Based on these preliminary results, the IMS/MS instrument is anticipated to have potential for fast screening analysis that can be applied, for example, in environmental and drug analysis. PMID:15565719

Classification problems have been frequently encountered in visual mobile robot navigation. The studies reported so far are mainly focused on the single label problem; i.e., each sample (datum) is assigned to a single class. In the case when a sample belongs to multiple classes simultaneously, most existing approaches attempt to avoid handling this situation by labeling the samples subjectively with the base class, which is the most obvious to them, or by considering them as a new class. In this paper, a new multi-instance multi-label learning (MIML) algorithm, called MIMLGP, is proposed by using Gaussian process (GP) for solving the multiple labels problems in visual mobile robot navigation. Compared with the existing multi-label (ML) algorithms, the MIMLGP method represents each sample w...

Samples of pure and commercial powder PVC was irradiated with 0-100 kGy {gamma} radiation. The visible yellowness observed in this samples occurred when they were irradiated as of 50 kGy. The Tg values obtained from DSC showed the plasticizers influence in the polymeric mobility. The IR spectra showed the presence of C=O in the no irradiated pure PVC, originated by the polymerization process. The addition of plasticizers favors the radiolytic oxidation. (author). 8 refs., 3 figs.

Raman spectra at 298 and 77 K of three uranophane samples from different localities are described and interpreted. The spectra are sample dependent. U O bond lengths in uranyls are calculated from the spectra and compared with the published data of single crystal structure and EXAFS spectroscopy. Hydrogen-bonding of water molecules and silanols is discussed and the ‘proton mobility’ in uranophane sheet crystal structure is assumed.

We report on the recording characteristics of a hologram in a soda-lime glass plate. A surface relief holographic grating on an azobenzene polymer film coated on a glass plate is recorded in the glass plate using corona charging. The holographic grating recorded in the glass plate is directly read out. The first-order diffraction efficiency is 0.03% at a wavelength of 633 nm. The thermal, UV light, and water resistances of the hologram are also evaluated.   

Three centrosymmetric, mononuclear cobalt(II) complexes possessing large zero-field splitting parameter D have been studied by means temperature-dependent FAR infrared spectroscopy. From 15 temperature-dependent absorption peaks referring to the transition between the six lowest crystal-field multiplets the value of the D-parameter has been directly read off. These data are comparable with those values extracted by fitting the magnetic susceptibility and magnetization data.

Stable colloidal suspensions of buckminsterfullerene (nC(60)) in aqueous environments can significantly affect the fate and transport of hydrophobic organic contaminants by serving as a contaminant carrier. In this study, we examined enhanced transport of 2,2',5,5'-polychlorinated biphenyl (PCB) in saturated sandy soil columns by a variety of nC(60) samples, including an nC(60) sample prepared by the typical solvent exchange method, as well as eight natural organic matter (NOM) or surfactant-modified nC(60) samples, prepared by phase-transferring C(60) from toluene to an NOM or a surfactant solution. Whereas the NOM- and surfactant-modified nC(60) samples have mobility similar to the unmodified nC(60), their contaminant-mobilizing capabilities are significantly greater: breakthrough of PCB increases by 47.2 to 227% with the surfactant-modified nC(60) samples and by 233 to 370% with the NOM-modified nC(60) samples. The significantly enhanced contaminant-mobilizing capability of the modified nC(60) is likely due to a combined effect of increased adsorption affinities and increased tendency of desorption nonequilibrium, likely caused by the changes of nC(60) aggregation properties induced by the presence of NOM or surfactant. Findings in this study indicate that nC(60) formed in different processes might have vastly different effects on contaminant fate and transport. PMID:22500825

Reverse flow-injection analysis (rFIA) involves injection of the detection reagent into a mobile phase of sample. rFIA is one of the FIA modes used to minimize reagent consumption, decrease sample dispersion, improve mixing efficiency and enhance the sensitivity. This simple, inexpensive approach is also applied to multi-component analysis by sequential injection of different reagents in the flowing stream of the sample. rFIA is particularly important in water analysis due to the abundance of the sample. We describe several methods for determination of cations, anions, and organic substances. We also review other applications, such as pharmaceutical, biomedical and industrial analysis.

The Essex Aluminum Plant produces aluminum components for automobile engines using a flux containing fluoride and Cl2 gas. Concentrations of HF and HCl in ambient air near the plant were measured by a mobile tandem mass spectrometer and were found to exceed air quality standards. This report provides the results of an investigation that used grass tissue samples as biological monitors of these air contaminants. Samples of grass were taken at several locations and silver maple foliage was also sampled at some locations. The samples were analyzed for fluoride and, in the early studies, for chlorine.

Data are reported for volatile/mobile Ag, As, Au, Bi, Cd, Co, Cs, Cu, Ga, In, Rb, Sb, Se, Te, T1 and Zn in exterior and/or interior samples of four Antarctic meteorites: 77005 (unique achondrite); 77257 (unreilite); 77278 (L3); 77299 (H3). Exterior samples reflect contamination and/or leaching by weathering but trace element (ppm-ppt) contents in interior samples seem reasonable for representatives of these rare meteoritic types. The 77005 achondrite seems related to shergottites; other samples extend compositional ranges previously known for their types. With suitable precautions, Antarctic meteorite finds yield trace element data as reliable as those obtained from previously known falls.

Purpose: This research fulfills a void in offender mobility discourse. Metropolitan socioeconomic and spatial structure, defined in crime pattern theory as the urban backcloth, plays a significant role in shaping travel behavior; and yet, current analysis of offender mobility continues to favor individual characteristics to account for travel range. Methods: Using a large sample of juveniles, both delinquent and at-risk youth (N=2,552), this study compared the predictive utility of individual characteristics against indicators of urban backcloth. Results: Delinquent youth were found to be more sensitive to the environmental conditions exerted by community-level socioeconomic characteristics than their at-risk counterparts. However, two factors-intercity hierarchical structure and motor veh...

Defect density in HAMCO Czochralski silicon was measured. A sufficiently high precipitate density was found to cause a reduction in the minority carrier lifetime, and thus, cell efficiency. Mobility studies in SEMIX UCP silicon were conducted under both dark and illuminated conditions. Results from these measurements indicate that the grain boundaries act primarily as potential barriers to reduce the mobility. Neutron activation analysis was used on selected samples provided by JPL for testing of trace elemental analysis, yielding generally good results. Thin layers of microcrystalline silicon on single crystal silicon substrates were analyzed to determine hydrogen content, the ratio of amorphous/microcrystalline material, and higher efficiency when containing higher concentrations of hydrogen.

The correlation length ({Lambda}) of interface roughness in GaAs/AlAs quantum wells (QWs) prepared by molecular beam epitaxy (MBE) was studied by measuring and analyzing the electron concentration dependences of mobilities. When the bottom AlAs barrier of QWs is prepared by alternate beam MBE and/or by the use of superlattice buffer beneath the QW, the mobility of two-dimensional electrons is substantially enhanced. The lateral correlation length {Lambda} of such samples is found to become as large as 200-300 A. We have found that {Lambda} of the bottom (GaAs-on-AlAs) interface on the QW is about 70 A when prepared by conventional MBE. (orig.).

Chitosan acetate-ammonium nitrate (NH4NO3) films have been prepared by the solution-cast technique. Fourier transform infrared spectroscopy (FTIR) showed that complexation has occurred. FTIR exhibited shifts in amine and carbonyl bands from 1553 to 1520 cm-1 and 1636 to 1617 cm-1. A new peak was also observed at 1746 cm-1. XRD shows that all complexes are amorphous. The highest conductivity at room temperature is 2.53×10-5 S cm-1 for the film containing 45 wt% NH4NO3. The conductivity of the samples is dependent on the number of mobile ions and mobility.

We report on measurements of single-molecule Brownian motion in liquid crystals, unravelling the anisotropic mobility of individual dye molecules. This anisotropic Brownian motion is directly correlated with the structural properties in a smectic A (8CB) and a nematic (5CB) liquid crystal sample cell on the micrometer scale using polarization contrast microscopy. A considerably slower mobility of dye molecules is found as compared to self-diffusion measurements by NMR, while anisotropy values compare well to recent literature data. This is suggested to be related to local distortions of the director structure around the dye molecules. PMID:23083329

A new characterization method for hydrogels based on the relaxation behavior of superparamagnetic nanoparticles (MNPs) is proposed. MNPs are incorporated in the hydrogel to examine its network properties. By analyzing their relaxation behavior, incorporated and mobile nanoparticles can be studied. In the case of mobile nanoparticles, the microviscosity of the hydrogel can be determined. Thus, this method allows the studying of gelation as well as the degradation process of hydrogels. Furthermore, the hydrogel can have any shape (e.g. microspheres or larger blocks) and no sample preparation is needed, avoiding artefacts.

The properties of point defects in Fe(Cr{sub x}) ferritic alloys with x = 5, 10, 15 at% were investigated in samples irradiated at 21K by 2.5 or 3 MeV electrons. The mobilities of interstitials and vacancies were determined during post-irradiation anneals by residual electrical resistivity and 77 K positron lifetime measurements. It was concluded that vacancies are mobile below room temperature ({approx} 225 K). The data are compared with those obtained in austenitic Fe-Cr-Ni alloys. 13 refs.; 4 figs.; 3 tabs..

This book is a step-by-step tutorial aimed at beginners to Sencha Touch. There is ready sample code explained with essential screenshots for better and quicker understanding. This book is ideal for anyone who wants to gain the practical knowledge involved in using Sencha Touch mobile web application framework to make attractive web apps for mobiles. If you have some familiarity with HTML and CSS, then this book is for you. This book will give designers the skills they need to implement their ideas, and provides developers with creative inspiration through practical examples. It is assumed that

Glass/metal interfaces are common in batteries, fuel cells, and oxygen sensors. An electric field imposed on a glass/metal interface can lead to degradation, which can result in failure. Defects at the interface can accelerate the degradation through ion migration, metal migration, and gas evolution. In this study of glass/metal interfaces under the influence of an electric field, lithium silicate gels between aluminum substrates were used to simulate ion migration, and characterize the effects with dielectric measurements and impedance spectroscopy. Sol-gel prepared lithium silicates were used for easy control of composition and microstructure. Samples contained 5, 10 and 15 weight percent lithium oxide (Li2O), called LS5, LS10 and LS15, respectively. Samples generally were disc shaped, 15 mm in diameter and 10 mm thick. The samples were exposed to an AC frequency generator that produced an electric field of about 20 kV/cm. Samples were exposed for different periods of time, 1, 2, 3, 4, and 5 minutes. Dielectric measurements were used as an indication of the effect of high voltage, where lithium ions respond to the high voltage, but cannot relax at room temperature. Capacitance, dissipation factor and series resistance were measured and the dielectric constant was calculated. The dissipation factor showed an increase with increasing lithium content, indicating that energy is dissipated when there are a large number of mobile ions. Similarly, the resistance increased with increasing exposure time in LS15. The dielectric measurements showed that the samples were affected by exposure to high field in times less than 5 minutes, with the largest effects occurring in the LS15 samples. Impedance spectroscopy was used to study the samples under alternating current conditions. The sample impedance was measured over a range of frequencies (5 Hz to 65 KHz), and conductivities, mobility, and relaxation times were calculated. The mobility in LS15 was 4 orders of magnitude higher than the mobility in LS5 or LS10, especially at low frequency. This corresponds to a higher conductivity in LS15, which contains more mobile ions. The relaxation time in LS15 is 2 orders of magnitude longer than for LS5 and LS10. At the same time, this means the LS15 gel has higher conductivity that reduces the polarization of the material. In conclusion, the impedance spectroscopy and the dielectric measurements both show a difference in response between LS15 and the compositions with less lithium oxide. In addition, the high field caused measurable differences within 5 minutes of exposure. The effects of exposure were more severe in LS15 because of the higher number of mobile ions.

This paper describes the mobilization and speciation of As found in hydrothermally altered rock under oxic column conditions. The altered rock sample was obtained from a tunnel project located in the Nakakoshi area of Hokkaido, Japan, whose geology is represented by slate, shale and sandstone. This area has undergone silicification, pyritization and argillic alteration resulting in As-enrichment of the rock. Results of the column experiments show that the infiltration rate, bulk density and rock bed thickness affected the duration of water residence, which in turn influenced the pH of the rock-water system. Coexisting ions most notably Ca^2^+ at amounts greater than ca. 50mg/L retarded the mobilization of As. Mobilization of As from the rock with time occurred in two stages: stage 1 (weeks...

Abstract in english This study aimed to evaluate the nutrient digestibility of roughages in horses with total feces collection and mobile bags. Two trials were carried out simultaneously. The first trial evaluated the digestibility of nutrients of coastcross hay (Cynodon dactylon cv. coastcross) with total feces collection. The second trial assessed the digestibility of nutrients of alfalfa hay (Medicago sativa), peanut (Arachis pintoi) and coastcross hay with mobile bags. This trial was con (more) ducted with gastric insertions of nylon bags every 12 hours, and each bag contained 663 mg of feed samples in a proportion of 17 mg DM/cm². Feces and bags were collected directly from the stall floor immediately after excretion. There was no difference between the digestibility of dry matter, crude protein, carbohydrates and hydrolysable carbohydrates of coastcross hay estimated with feces collection and mobile bags. Forage peanut showed high nutrients digestibility, with values close to those observed with alfalfa, indicating potential for use in diets for horses.

Purpose Focal adhesion kinase (FAK) and Src are protein tyrosine kinases, localized in the focal adhesions, which, upon activation interacts each other, regulate several cellular signaling pathways implicated in malignant transformation and disease progression. The present study aimed to evaluate the clinical significance of FAK and Src protein expression in mobile tongue squamous cell carcinoma (SCC). Methods FAK and Src protein expression was assessed immunohistochemically on 48 mobile tongue SCC tissue samples and was analyzed in relation with clinicopathological characteristics, overall and disease-free patients??? survival. Results FAK positivity was noted in 32 (66.67 %) and Src positivity in 45 (93.75 %) out of 48 mobile tongue SCC cases. FAK and Src protein expression was signifi...

kirkbride g., floyd v., tate c. & wendler m.c. (2012) Journal of Nursing Management 20, 344-353 -Weathering the storm: nurses- satisfaction with a mobile admission nurse service Aim- To evaluate nurses- satisfaction with, and perceptions of, a practice innovation introducing a Mobile Admission Nurse service. Background- Staff nurses identified that the admission process, while crucial to initiating safe and appropriate acute care, can be disruptive and interfere with care in progress. A pilot project implementing the role of a Mobile Admission Nurse was introduced to address this need. Method- A self-developed web-based survey was administered to a convenience sample of 104 RNs who had used the services during the pilot project. Results- Staff nurses (n-=-78) reported a chaotic, demanding ...

Elution phenomena of size exclusion chromatography (SEC) plus superimposed adsorption effects for oligostyrenes, epoxy resins, methylated melamine-formaldehyde resin prepolymers, p-cresol-formaldehyde resin prepolymers, and phenol-formaldehyde resin prepolymers were investigated. SEC and superimposed adsorption effects could be elucidated from a concept of solubility parameter. Minimum retention volumes of these obligomers were obtained with the mobile phases of chloroform/methanol, 80/20 or 60/40 (v/v), and separation was expected to be mostly performed by SEC. The solubility parameter of polyvinyl alcohol gels was estimated to be between 21 and 23 from the above results. Elution for normal phase chromatography was in the order of increasing molecular weight and that for reversed-phase chromatography was in the order of decreasing molecular weight. These are reversed phenomena to those for low-molecular weigh compounds. Solubility of sample solutes to mobile phase must be considered. Methanol mobile phase-polyvinyl alcohol gel system might be exception.

A method to measure the rate constant for the formation of symmetrical proton-bound dimers at ambient pressure was proposed. The sample is continuously delivered to the drift region of an ion mobility spectrometer where it reacts with a swarm of monomer ions injected by the shutter grid. Dimer ions are formed in the drift tube and a tail appears in the ion mobility spectrum. The rate constant is derived from the mobility spectra. The proposed approach was typically examined for methyl isobutyl ketone (MIBK), 2,4-dimethyl pyridine (DMP), and dimethyl methyl phosphonate (DMMP). The rate constants measured in this study were: 0.25x10-9, 0.86x10-10, and 0.47x10-10cm3s-1 for MIBK, DMP and DMMP, respectively. The logarithm of the measured rate constants were found to be almost independent of rec...

Purpose - The purpose of this paper is to explore a conceptual model for analyzing customers' perceptions of using mobile commerce services for online shopping. This paper provides insights into consumer behavior, and the results have important implications for designers, managers, marketers, and system providers of mobile shopping (m-shopping) web sites. Design/methodology/approach - An empirical investigation was carried out to test the hypotheses. The samples include 369 professional participants. For testing the relationships of the model, structural equation modeling (SEM) is used. Findings - The results demonstrate that anxiety, which is an affective barrier against using innovative systems, is a key negative predictor of a customer's intentions to use mobile phones. Also, the consum...

Explosives in solution were determined as mixtures containing highly volatile improvised explosives such as peroxides and conventional military grade explosives such as PETN, RDX, and Tetryl using a high speed gas chromatograph with differential mobility detector in a single measurement. Instrument parameters were evaluated and adjusted to permit detection of nanogram amounts of explosives with this broad range of vapor pressures in times under 3 min for HMTD to TNT or under 16 min for HMTD to Tetryl. As in prior studies of response to explosives with mobility spectrometers, pre-separation of sample by gas chromatography improved response in the differential mobility detector; however, unlike prior configurations, the supporting gas atmosphere did not contain modifiers to adjust selectivit...

Sequential extractions utilizing the modified Tessier scheme (Krishnamurti et al., 1995) and measurements of soluble and particulate metal released from suspended solids were used in this study to determine the speciation and mobility of inorganic contaminants (As, Cr, V, U, Cd, Ni, and Mn) found in corrosion scales and particles mobilized during hydraulic flushing events. Arsenic, chromium and vanadium are primarily associated with the mobilization-resistant fraction that is resistant to all eluents used in this study and also bound in highly stable crystalline iron oxides. Very low concentrations of these elements were released in resuspension experiments. X-ray absorbance measurements demonstrated that arsenic in the sample with the highest As concentration was dominated by As(V) bound ...

FITC-albumin, Lsr-F, or fluorescent polystyrene latex particles were electrosprayed from aqueous buffer and subjected to dispersion by differential electrical mobility at atmospheric pressure. A resulting narrow size cut of singly charged molecular ions or particles was passed through a condensation growth tube collector to create a flow stream of small water droplets, each carrying a single ion or particle. The droplets were splash landed (impacted) onto a solid or liquid temperature controlled surface. Small pools of droplets containing size-selected particles, FITC-albumin, or Lsr-F were recovered, re-electrosprayed, and, when analyzed a second time by differential electrical mobility, showed increased homogeneity. Transmission electron microscopy (TEM) analysis of the size-selected Lsr-F sample corroborated the mobility observation. PMID:22283555

The U.S. EPA estimates that 40 percent of U.S. rivers are ecologically impaired by sedimentation. On dam- controlled rivers that are impaired by sedimentation, flushing flows with the potential to flush the fine sediments are commonly prescribed to improve ecological conditions. One goal of these flushing flows is to mobilize the riverbed's coarse surface layer and thus to create the potential to release fine sediment trapped beneath the surface. Given the economical value of water, releasing flows large enough to generate shear stresses adequate to mobilize the coarse surface can be difficult. Gravel augmentation using fine gravel has been recently demonstrated as a viable alternative to mobilizing coarse surface layers. This occurs because sheets of fine gravel smooth the bed, increasing the local shear stress available to move the grains. Does the mobilization of the coarse surface layer by fine gravel increase the depth to which fines are selectively removed or decrease the amount of fine sediment in the bed subsurface? To answer this question we conducted two series of laboratory experiments designed to flush or selectively remove fine sediment from the bed subsurface in a 28 m long and 0.86 m wide gravel-bedded flume channel. Before each experiment, we fed fine sediment (2,000 g/min; D50 = 0.4 mm) into the flume to saturate the gravel bed (D50 = 10 mm). The flow during the infiltration period was competent to transport the sand as bedload but not to suspend it (Q = 0.05 m3/s). In the first series of experiments, we attempted to flush the fine sediment from a non-mobile bed with a steady flow that was not competent to mobilize the coarse surface layer (Q = 0.205 m3/s). In the second set of experiments, the magnitude (Q = 0.205 m3/s) and duration of the flow conditions were the same; however, we fed fine gravel into the flume that moved thru the flume as bedload sheets and mobilized the coarse surface layer. After each experiment, we photographed the bed, excavated the bed in layers, collected bulk samples, and measured the depth to which flushing occurred using a laser scanner with sub-millimeter accuracy. We expect that our results will be useful in predicting the maximum flushing depth that can be achieved under non- mobile bed and mobile bed conditions, whether the bed is mobilized by fine gravel pulses or simply by increasing the flow.

During sluicing of the first batch of sludge from tank 241-C-106 on November 18, 1998, an unexpected high concentration of volatile organic compounds was measured in the 296-C-006 ventilation stack. Eleven workers reported irritation related symptoms and were sent to Hanford Environmental Health Foundation (HEHF) and Kadlec Hospital for medical evaluations. No residual health effects were reported. As a result of the unexpectedly high concentrations of volatile organic compounds encountered during this November sluicing event, a phased process test designed to characterize the emission constituents was conducted on December 16, 1998, March 7, 1999, and March 28, 1999. The primary focus of this evaluation was to obtain samples of the 296-C-006 ventilation stack effluent and surrounding areas at elevated levels of volatile organic compounds initiated by sluicing. Characterization of the emission constituents was necessary to establish appropriate procedural and administrative exposure controls for continued sluicing. Additionally, this information would be used to evaluate the need for engineered equipment to mitigate any further potential chemical stack emissions. This evaluation confirms that the following actions taken during Phase I, Phase II, and Phase III of the Waste Retrieval Sluicing System Emissions Collection Process Test were conservative and appropriate for continued sluicing: Implement stack limit of 500 ppm volatile organic compounds, with lower administrative limits; Ensure worker involvement through enhanced planning; Continue using the existing fenced boundary location; Continue using pressure demand fresh air respiratory protection inside the C-Farm as recommended by Industrial Hygiene; Continue using the existing respiratory protection/ take cover requirements outside the C-Farm boundary as recommended by Industrial Hygiene; Continue using existing anti-contamination clothing; Minimize the number of workers exposed to emissions; Maintain the number of workers exposed to emissions; Maintain the current stack height; Maintain the current 2 ppm volatile organic compound direct reading instrument administrative level; Evaluate the use of a chemical stack filter for future sluicing evolutions on other tanks; Continue to evaluate more sensitive monitoring equipment; and Consider the use of in-line monitoring equipment for future sluicing evolution on other tanks.

The electronic characteristics of nano-wires made of high-mobility AlxGa1-xN/GaN heterostructures have been studied. The AlxGa1-xN/GaN samples were grown on GaN-template buffer layer by plasma-assisted molecular beam epitaxy. We obtained the mobility and carrier density of two-dimensional electron gas to be 9328 cm^2/Vs and 7.917x10^12 cm-2 by conventional van der pauw Hall measurement at temperature of 77K, respectively. We prepared the samples of field-effect-transistors and reduced the width of the conducting channel from 1?m to 100 nm by Focus Ion Beam. The Shubnikov-de Haas oscillations were observed by magneto-resistance measurement at 0.3 K and the electronic properties for the samples of different channel widths were under investigation.

The Savannah River Site manufactures nuclear materials for the U.S. Department of Energy. This paper describes how in recent years robots and mobile teleoperators have been used to reduce the radiation exposure of personnel at this site. The Shielded Cells Waste Handling Robot and the Shielded Cells Sampling Handling Robot have both significantly reduced radiation exposure. The Shielded Cells Waste Handling Robot has been in operation for over four years. It removes cans of radioactive waste from the Shielded Cells, seals the can in a plastic bag, and places the cans in a waste drum. The Shielded Cells Sample Handling Robot has been in operation for only a few months. It opens a door to one of the Shielded Cells, removes a radioactive sample from a shielded container, places it in the cell, and closes the door. Mobile teleoperators have significantly reduced radiation exposure in the removal of a contaminated junction box, and lead removal from radioactive vessels.

Using standard capillary electrophoretic and ion mobility methods, several electrospray interface designs were investigated for the capillary electrophoretic introduction of samples into the ion mobility spectrometer. Of the interfaces investigated, the flow assisted interface and the direct coupled interface showed the most promise. These preliminary experiments were encouraging. The ion mobility spectrometer coupled with a capillary electrophoretic introduction system operated with excellent separation efficiency and ion mobility reproducibility. Using tetrabutylammonium iodide, the number of theoretical plates for the spectrometer was calculated to be 3.10(3) and reduced mobilities were found to be reproducible with a relative standard deviation of 1.43%. Because of the desire to hold the spectrometer as hot as possible, the solvent would often vaporize in the interface, creating an unstable spray and inhomogeneities in the electrophoretic field. More work is needed to improve the spray process which contributed to the overall noise of the system and to eliminate the phenomenon of solvent vaporization which limited the reproducibility of electrophoretic migration times. PMID:2592482

This research aims to assess the effect of the application of biosolids compost and phytoremediation on the mobility of total and biodisponibles (DTPA) fractions of cadmium, copper, lead, and zinc from different horizons of a superficially contaminated soil. Leaching experiment in soil columns was proposed. Treatments contemplated application of compost biosolid and phytoremediation. Two destructive samplings were performed. Total and DTPA trace metals were identified in each horizon. The overall performance of the various elements in its total and DTPA forms show greater concentration in horizon A and fewer gradients between horizons Bt and BC, thus assuming that the high content of clay in horizon Bt (62.9%) limits its movement through the horizons. In the mobile nutrients, a greater mobility was evidenced in DTPA fractions if compared to Total fractions. In the horizon A, the more mobile metals, such as Zn and Cd, evidenced a greater percentage of DTPA/Total fractions in all treatments. The application of compost with or without plant diminished the mobilization of Zn, Cu, and Cd Total, thus limiting a potential leaching to inferior horizons. However, this effect was not observed in the DTPA fraction. PMID:22567706

This study examined screen media time usage (SMTU) and its association with personal and socioeconomic factors, as well as the effect of season and type of day, in a Spanish sample of 12-16 year-old school adolescents (N=323). The research design was a cross-sectional survey, in which an interviewer-administered recall questionnaire was used. Statistical analyses included repeated measures analyses of variance, analysis of covariance and structural equation models. Results showed an average of 2.52h per day of total SMTU and partial times of 1.73h per day in TV viewing, 0.27h per day in computer/videogames, and 0.52h per day in mobile use. Four significant predictors of SMTU emerged. Firstly, the type of school was associated with the three media of our study, particularly students from state/public school spent more time on them than their private schools counterparts. Secondly, older adolescents (14-16 years old) were more likely to use computer/videogame and mobile phone than younger adolescents. Thirdly, the more accessibility to household technology the more probable computer/videogames and mobile phone were used. Finally, boys spent significantly more time in mobile phone than girls. Additionally, results revealed that adolescents seemed to consume more TV and computer/videogames in autumn than in winter, and more TV and mobile phones on weekends than on weekdays, especially among state school students. Findings from this study contribute to the existing knowledge on adolescents' SMTU patterns that can be transferred to families and policies. PMID:18694592

This work focuses on testing and application of Sr isotope signatures for the fast and reliable authentication and traceability of Asparagus officinalis originating from Marchfeld, Austria, using multicollector inductively coupled plasma mass spectrometry after optimised Rb/Sr separation. The major sample pool comprises freeze-dried and microwave-digested asparagus samples from Hungary and Slovakia which are compared with Austrian asparagus originating from the Marchfeld region, which is a protected geographical indication. Additional samples from Peru, the Netherlands and Germany were limited in number and allowed therefore only restricted statistical evaluation. Asparagus samples from Marchfeld were harvested within two subsequent years in order to investigate the annual variation. The results show that the Sr isotope ratio is consistent within these 2 years of investigation. Moreover, the Sr isotope ratio of total Sr in soil was found to be significantly higher than in an NH{sub 4}NO{sub 3} extract, reflecting the mobile (bioavailable) phase. The isotope composition in the latter extract corresponds well to the range found in the asparagus samples in Marchfeld, even though the concentration of Sr in asparagus shows no direct correlation to the concentration of Sr in the mobile phase of the soil. The major question was whether the 'Marchfelder Spargel' can be distinguished from samples from the neighbouring countries of Hungary and Slovakia. According to our findings, they can be clearly (100%) singled out from the Hungarian samples and can be distinguished from the Slovakian asparagus samples with a probability of more than 80%. (orig.)

In order to differentiate two species of Radix Puerariae (Radix Puerariae lobatae and Radix Puerariae thomsonii) and to determine major isoflavonoids (puerarin, daidzin, daidzein and genistein) in the samples, a simple high performance liquid chromatography (HPLC) method with isocratic elution employing cyclodextrins (CDs) as mobile phase additives was developed. Various factors affecting the retention of isoflavonoids in the C(18) reversed-phase column, such as the nature of CDs, the concentration of hydroxypropyl-?-cyclodextrin (HP-?-CD) and the methanol percentage in the mobile phase, were studied. Experimental results confirmed that HP-?-CD, as a very effective mobile phase additive, could markedly reduce the retention of isoflavonoids, especially daidzein and genistein. The elution of four isoflavonoids could be achieved on a Kromasil(®) C(18) column within 56 min by using the methanol-water contained 5 mM HP-?-CD (25/75, v/v) mixture as the mobile phase. The formation of the inclusion complexes between isoflavonoids and HP-?-CD explained the modification of the retention of analytes. The apparent formation constants determined by HPLC confirmed that the stoichiometry of HP-?-CD-isoflavonoid complexes was 1:1, and the stability of the complexes depended on the size and property of isoflavonoids. The optimized method was successfully applied for the simultaneous determination of major isoflavonoids in P. lobatae and P. thomsonii samples. This work provides a useful method for the analysis of traditional Chinese herbs. PMID:22177078

Few species are distributed uniformly in space, and populations of mobile organisms are rarely closed with respect to movement, yet many models of density rely upon these assumptions. We present a hierarchical model allowing inference about the density of unmarked populations subject to temporary emigration and imperfect detection. The model can be fit to data collected using a variety of standard survey methods such as repeated point counts in which removal sampling, double-observer sampling, or distance sampling is used during each count. Simulation studies demonstrated that parameter estimators are unbiased when temporary emigration is either \\

Surface morphology of high mobility heterostructures is examined and correlated with d.c. transport. {\\it All} samples examined show evidence of lines in the [1$\\bar{1}$0] direction with roughness ranging from small amplitude features to severe anisotropic ridges. Transport in these samples is consistent with that in samples having artificially induced 1D charge modulations. The native surface properties reflect a prevalent, anisotropic disorder affecting 2D electron conduction. Importantly, the native lines are orthogonal to the stripes theoretically proposed to explain high Landau level transport anisotropies.

Incineration residues contain both inorganic and organic material. The organic material may affect the mobility of pollutants in e.g. landfills or geotechnical constructions. Limit values of TOC (total organic carbon), determined according to European standard are stipulated to reduce the disposal of organic materials. The European standard methods to determine TOC and DOC (dissolved organic carbon) are evaluated. Factors controlling the mobility of DOC and its effect on metal mobility have also been studied. Determination of TOC according to European standard methods EN 13137 and EN 1484 include those carbon fractions that are oxidized during combustion. The definition of TOC as total organic carbon is not equivalent with the analytical result. The European standards on the definition of TOC need revision. Both organic and elemental carbon are oxidized upon heating, and the analytical TOC is thus a sum of organic and elemental carbon present in the sample. Since elemental carbon comprise the major part of the analytical TOC in solid samples of incineration residues, such results will most likely be misunderstood. Revision of the standard method EN 13137 is recommended to better suit incineration residues. The L/S ratio (the relationship between the mass of liquid and the mass of solid material), excessive carbonation (addition of CO{sub 2} until the pH in the solution was stable for 2.5 h) and extraction pH were the main factors controlling the mobility of DOC in incineration bottom ash. Up to {approx}60 weight-% of the TOC in the bottom ash could be mobilized by controlling these factors (i. e. by using them as parameters). Only a minor part of the TOC ({approx}7 weight-%) in APC residues was extractable with water, indicating a high proportion of elemental carbon. Water-soluble organic compounds may affect the mobility of metals in several ways. The formation of DOC-metal complexes has a direct effect on the metal mobility. Biological degradation of organic material may also affect the metal mobility indirectly due to changes of pH and redox-potential. The complexation capacity of DOC can be used in the development of washing as a pretreatment process of incineration residues. Excessive carbonation may be useful in a washing process to enhance the separation of metals. Further treatment-oriented investigations of bottom ashes and APC residues are recommended in the development of a washing process of the materials.

High-salt stacking in electrokinetic chromatography (EKC) is defined and contrasted to the sweeping method. A recent paper argued the two methods are identical, where high concentrations of micelle in the sample were intended to mimic the effect of high-salt stacking. However, high micelle concentration in the sample matrix in EKC is analogous to using a high-conductivity sample instead of a low-conductivity sample in field amplified stacking. High-salt stacking does not require a sample free of pseuostationary phase, only a sample with a high-mobility co-ion compared to the separation buffer electrokinetic vector. High-salt stacking uses a discontinuous buffer system and should not be confused with continuous buffer stacking systems such as sweeping. PMID:15146909

Mobile phones have been a part of our everyday life in the developed world since the late 1990s. This has raised concerns over the potential health risks of mobile phone use. Biological and health effects potentially caused by mobile phone radiation have been extensively studied and several biological and medical endpoints have been examined. So far, results have not been conclusive on the potential effects of mobile phone radiation. Mobile phones generate a modulated radio frequency electromagnetic field (RF-EMF), which is a form of non-ionizing radiation. This means that mobile phone radiation does not have enough energy to ionize atoms and it cannot break chemical bonds directly (e.g., in DNA strands). There could, however, be other mechanisms by which mobile phone radiation may affect cellular and physiological functions. Whether these mechanisms exist is unknown. In this thesis, large-scale screening techniques, such as proteomics, were applied to examine changes on the proteome level after exposure to mobile phone radiation. Proteomics techniques allow the screening of several hundreds, and even thousands, of proteins simultaneously, and are thus more efficient than single endpoint techniques. Four different types of human endothelial cells (two cell lines, two types of primary cells) were exposed to two types of mobile phone radiation (900 and 1800 MHz GSM). The proteome of these cells was examined immediately after short-term exposure using two-dimensional gel electrophoresis (2DE). Two protein detection/analysis techniques were used: silver staining for the cell line samples and difference gel electrophoresis (DIGE) for the primary cells. 2DE-DIGE technology is currently a state-of-the-art technique in 2DE studies. Several changes were found in the proteome of the human endothelial cell line EA.hy926 after exposure to 900 MHz GSM mobile phone radiation. In addition, the proteome of a variant of the same cell line, the EA.hy926v1, was affected after 900 MHz GSM mobile phone radiation exposure, but the altered proteins were different from those in the EA.hy926 cells. The changes in the proteome of the EA.hy926 cells were weaker after 1800 MHz GSM exposure compared to those after 900 MHz GSM exposure. Furthermore, certain proteins affected earlier after 900 MHz GSM exposure were unaffected after 1800 MHz GSM exposure. The proteome of the primary human endothelial cells was not affected after 1800 MHz GSM exposure when examined using 2DE-DIGE technology. 2DE-DIGE technology is more reliable than the technology used with the EA.hy926 cell line, and these results should therefore be highly relevant when assessing the potential immediate effects of mobile phone radiation. The results presented in this thesis on the proteome-level effects of mobile phone radiation exposure are contradictory. The results with EA.hy926 cells suggest that minor effects do occur, whereas no effects were observed when using the more reliable 2DE-DIGE technology and primary cells. The responses with EA.hy926 cells varied according to the cell variant and exposure conditions, and consistent responses at the cellular level could not therefore be identified. Further research is recommended to understand the variation in responses and whether consistent cellular-level responses exist. (orig.)

The molecular events implicated in the development of endometrial carcinosarcoma remain poorly understood. Using complementary DNA microarrays, we analyzed a group of 15 endometrial carcinosarcomas and compared their gene expression profiles with those obtained from a group of 23 endometrioid endometrial carcinomas. We demonstrated changes in the expression of genes modulating processes such as the epithelial to mesenchymal transition, muscle differentiation, the expression of cancer/testis antigens, and immune response in endometrial carcinosarcomas. The high mobility group AT-hook 2 gene is an embryonic nuclear factor that mediates epithelial to mesenchymal transition in various tumor models, and it was among the genes overexpressed in endometrial carcinosarcomas. High mobility group AT-hook 2 overexpression was confirmed in 54% of endometrial carcinosarcomas by quantitative real time-polymerase chain reaction and immunohistochemistry. Moreover, we found a significant inverse correlation between the expression of high mobility group AT-hook 2 and let-7b, a member of the let-7 family of microRNAs that represses high mobility group AT-hook 2 expression. These changes were also associated with overexpression of Lin28B, a suppressor of microRNA biogenesis that is implicated in cancer progression and metastasis. Finally, high mobility group AT-hook 2 overexpression, which was detected in less than 3% of endometrioid endometrial carcinomas, was observed in many nonendometrioid carcinomas (46% of 28 samples). This pattern of expression, restricted to nonendometrioid carcinomas and endometrial carcinosarcomas, reflects a role for high mobility group AT-hook 2 in endometrial carcinogenesis that is associated with aggressive phenotypes and points to its potential use as a marker to distinguish between endometrioid and nonendometrioid tumors. PMID:22974476

Hydroxytyrosol [4-(2-hydroxyethyl)-1,2-benzenediol] is a well known natural polyphenolic component with antioxidative effects from olive oil and an aglycone of acteoside. In order to examine the in vivo metabolism of acteoside to hydroxytyrosol and the distribution of hydroxytyrosol in the blood and brain, microdialysis coupled to a liquid chromatographic system was developed to evaluate the pharmacokinetics of free-form hydroxytyrosol in rat blood and brain. Probes were implanted in the jugular vein and the brain hippocampus for blood and brain sampling purposes. Hydroxytyrosol in the microdialysis samples was separated by a reversed-phase C18 column and eluted with a mobile phase containing acetonitrile - 2% acetic acid (pH 2.6) (12:88, v/v), using a flow rate for the mobile phase of 1mL...

A method based on reverse phase capillary high performance liquid chromatography (capillary HPLC) coupled to laser-induced fluorescence detection (LIF) has been proposed for the determination of ochratoxin A (OTA) in wine samples. An anionic micellar medium was added to the mobile phase for increasing the fluorescence intensity and peak efficiency. Dispersive liquid-liquid microextraction (DLLME) has been used as a simple and efficient sample pretreatment method for the analysis of OTA in wines, being optimised by means of experimental design. The limit of detection was 5.5 ng L(-1) (3 × S/N) and recoveries for different wines ranged from 91.7 to 98.1%. The proposed methodology could be classified as a green analytical chemistry alternative, combining the low organic solvent volumes required in the DLLME with the reduced consumption of mobile phase in capillary HPLC. The use of LIF as detector provided an extremely sensitive method for the determination of OTA in wines. PMID:22868101

Cd concentrations in mobile phases of soil are more representative than total Cd concentration for estimating Cd bioavailability, physicochemical reactivity and mobility. In this study, selective sequential extraction procedures were used to determine Cd in different soil phases. Soil samples and plants grown in these soils were collected from a serpentine and copper-mining area in Maden-Elazig-Turkey. The extracted fractions were exchangeable/carbonate, reducible-iron/manganese oxides, oxidizable-organic matter and sulfides, and residual phases except silicates. Concentrations of Cd in soils and plant samples were determined by flame atomic absorption spectrometry and inductively coupled plasma-mass spectrometry. We found that Cd concentrations in the EDTA and NH2OH?HCl extracts are highe...

The weak antilocalization (WAL) effects of the two-dimensional electron gas (2DEG) in high mobility AlxGa1-xN/GaN heterostructure as well as beating patterns in the Shubnikov-de Haas (SdH) oscillatory magnetoresistance have been investigated by means of magnetotransport measurements before and after illumination. The zero-field spin splitting mainly arising from the Rashba spin-orbit coupling effect is studied using the weak antilocalization and beating patterns analysis, respectively. The Rashba spin-orbit coupling constant ? deduced using the weak antilocalization analysis showed a good agreement with that estimated from the analysis of the beating patterns for the sample before and after illumination. For our sample, the electron motion in the high mobility system is in the ballistic regime, the experimental WAL curves were fitted by a simulated quantum conductance correction according to a model proposed by [Golub [Phys. Rev. B 71, 235310 (2005)].

Short-term leaching test results of alkaline fly ash from Yenikoy coal-fired power plant were reported in this paper. ASTM D-3987-85 and TCLP-1311 test methods were applied to determine leaching behavior of selected elements namely, Fe, Ca, Cu, Co, Cd, Mn, Ni, Pb Zn, and Cr (VI) at different particle size fractions and test conditions. Chemical, mineralogical and morphological characterizations of ash samples were also performed using chemical, XRD and SEM-EDS analysis methods. The results showed that CaO dominates in the Yenikoy fly ash sample which directly affects the mobility of trace elements by determining the pH of the leaching medium. Higher mobility values of Cd, Co Cu, Pb, Ni and Zn elements were observed for TCLP-1311 procedure. The concentration of these elements in leachates s...

In northern part of Indian sub-continent, As related environmental and health issues receive attention from all over the world. Forty-eight sediment samples were collected from the Ganga Alluvial Plain (GAP) and its weathering products (from the Gomati River) for the study of As distribution and mobilization. These sediment samples were analyzed by Instrumental Neutron Activation Analysis (INAA) method using Cirus Research Reacter of Bhabha Atomic Research Centre, Mumbai. Average As concentrations in the GAP sediments (10.44?mg?kg?1), the Gomati River bed sediments (1.36?mg?kg?1) and the Gomati River suspended sediments (5.30?mg?kg?1) were reported. Significant decrease of As content from the alluvial sediments to the river sediments is a clear indication of its mobilization by chemical we...

Background, aim, and scope The mobility of arsenic in soils and its transfer to other environmental components present significant environmental risks. The management of polluted land is determined by the availability, mobility, and transfer of inorganic pollutants to different ecosystem compartments. In this paper, the fate of arsenic at this mining site has been evaluated to determine future management practises to minimise such risk. Materials and methods In a field study carried out in the area adjacent to a mining site at Bustarviejo (North Madrid, Spain), samples of soils, plants, and water were collected from areas adjacent to the core of the former mining activity. The following parameters were investigated in soil samples: pH, organic matter, pseudo-total As, P, and Fe, and labile...

Of the many state-of-the-art methods for cooperative localization in wireless sensor networks (WSNs), only very few adapt well to mobile networks. The main problems of the well-known algorithms, based on nonparametric belief propagation (NBP), are the high communication cost and inefficient sampling techniques. Moreover, they either do not use smoothing or just apply it offline. Therefore, in this article, we propose more flexible and efficient variants of NBP for cooperative localization in mobile networks. In particular, we provide: (i) an optional 1-lag smoothing done almost in real-time, (ii) a novel low-cost communication protocol based on package approximation and censoring, (iii) higher robustness of the standard mixture importance sampling (MIS) technique, and (iv) a higher amount ...

A sensitive liquid chromatography tandem mass spectrometry (LC/MS/MS) bioanalytical method was developed and validated to analyze lipoic acid (LA) in rat blood and brain samples. Ten mobile phase combinations were investigated during method development. Mobile phase combination of 0.1% acetic acid (pH 4 adjusted with ammonia solution)/acetonitrile was most optimum in terms of sensitivity and peak shape of LA and the internal standard, valproic acid. Sample extraction method was explored using liquid-liquid extraction and protein precipitation methods. Protein precipitation yielded the highest recovery of the analytes from blood and brain ranging from 92 to 115%. The lower limit of quantitation (LLOQ) of LA was 0.1ng/mL (0.485nM) in both blood and brain while on-column lower limit of detect...

An electric field application on ion exchange packing supports induced the release of sample solutes from the supports. When the electric field was applied temporary on the column, this phenomenon was observed as an increase in the pulsed concentration in the mobile phase. Namely a peak emerges on a chromatogram. The effect of the applied voltage on the ion exchange resin was examined by using a tiny mini-column. The sample solution was continuously passed through and the variations of effluent composition with and without application of electric field were analyzed. It was observed that amounts of increments of molar concentration of both benzoic acid and benzenesulfonic acid in mobile phase depended on the strength of the electric field. A theory of variation of distribution constant due to the electric field is proposed.   

Aims: The objectives of this study were to evaluate the effects of high fibrinogen concentration on erythrocyte deformability on mobilization of nitric oxide (NO) and of its metabolites in the presence of acetylcholine (ACh) in healthy human blood samples. Main methods: Levels of NO were evaluated by amperometric method. Nitrite, nitrate and S-nitrosoglutathione (GSNO) were measured using the spectrophotometric Griess reaction. Erythrocyte deformability was determined using the Rheodyn SSD laser diffractometer. Key findings: In the presence of high concentrations of fibrinogen and ACh (10mM) in the blood samples from healthy humans the erythrocyte nitrites, nitrates and GSNO concentrations increased without significant changes in NO efflux. Mobilization of NO in erythrocytes' presence was ...

Mars Exploration Rover Enhanced Telemetry Extraction and Reporting System (METERS) is software that generates a human-readable representation of the state of the mobility and arm-related systems of the Mars Exploration Rover (MER) vehicles on each Martian solar day (sol). Data are received from the MER spacecraft in multiple streams having various formats including text messages, sparsely-sampled engineering quantities, images, and individual motor-command histories.

This paper gives empirical results regarding the determinants of electricity consumption in manufactured housing, commonly called mobile homes. The data consist of a random sample of over 400 Florida electricity consumers - with information on socioeconomic characteristics, housing features and monthly kWh consumption. The model explains over 40% of the variation between customer usage, with signs and sizes of various coefficients fitting economic theory. The results for thermostat settings, site orientation and conservation investments are particularly interesting. (Author)

This study compared the drop-off detection performance with the two-point touch and constant contact cane techniques using a repeated-measures design with a convenience sample of 15 cane users with visual impairments. The constant contact technique was superior to the two-point touch technique in the drop-off detection rate and the 50% detection threshold. The findings may help an orientation and mobility instructor select an appropriate technique for a particular client or training situation. (Contains 1 table and 4 figures.)

We measure the effective Lande g-factor of high-mobility two-dimensional electrons in a modulation-doped AlAs quantum well by tilting the sample in a magnetic field and monitoring the evolution of the magnetoresistance oscillations. The data reveal that |g| = 9.0, which is much enhanced with respect to the reported bulk value of 1.9. Surprisingly, in a large range of magnetic field and Landau level fillings, the value of the enhanced g-factor appears to be constant.

The niobium electro-polishing is efficient if a viscous layer exists at the surface. In order to define parameters of samples electro-polishing, opened with difficulty to the experiments, the simulation is essential. This report presents works realized with the COMSOL software. The Nernst Planck equations have been associated to the Navier Stockes ones for an incompressible fluid. The study of the potential behaviour on the viscous layer and the mobility value have been detailed. (A.L.B.)

Hydrophilic interaction chromatography (HILIC) is valuable alternative to reversed-phase liquid chromatography separations of polar, weakly acidic or basic samples. In principle, this separation mode can be characterized as normal-phase chromatography on polar columns in aqueous-organic mobile phases rich in organic solvents (usually acetonitrile). Highly organic HILIC mobile phases usually enhance ionization in the electrospray ion source of a mass spectrometer, in comparison to mobile phases with higher concentrations of water generally used in reversed-phase (RP) LC separations of polar or ionic compounds, which is another reason for increasing popularity of this technique. Various columns can be used in the HILIC mode for separations of peptides, proteins, oligosaccharides, drugs, metabolites and various natural compounds: bare silica gel, silica-based amino-, amido-, cyano-, carbamate-, diol-, polyol-, zwitterionic sulfobetaine, or poly(2-sulphoethyl aspartamide) and other polar stationary phases chemically bonded on silica gel support, but also ion exchangers or zwitterionic materials showing combined HILIC-ion interaction retention mechanism. Some stationary phases are designed to enhance the mixed-mode retention character. Many polar columns show some contributions of reversed phase (hydrophobic) separation mechanism, depending on the composition of the mobile phase, which can be tuned to suit specific separation problems. Because the separation selectivity in the HILIC mode is complementary to that in reversed-phase and other modes, combinations of the HILIC, RP and other systems are attractive for two-dimensional applications. This review deals with recent advances in the development of HILIC phase separation systems with special attention to the properties of stationary phases. The effects of the mobile phase, of sample structure and of temperature on separation are addressed, too. PMID:21501708

The characterization and quantitation of aquatic organic colloids isolated from sedimentary porefluids was performed by size exclusion chromatography (SEC) with UV detection and ultrafiltration (UF) with total organic carbon analysis and UV detection. Separation of the samples and several well-characterized humic substances by SEC was found to be highly dependent upon the ionic strength of both the mobile phase and sample matrix. The elution of samples containing indifferent electrolyte concentrations by low ionic strength mobile phases yielded multipeak chromatograms and may be subject to misinterpretation as true molecular weight distributions. A dynamic coiling/uncoiling mechanism is offered as an explanation for the observed phenomenon. For well-characterized humic substances eluted with high ionic strength mobile phases, number- and weight-average molecular weights as well as the polydispersivities were calculated and were found to be in good agreement with other recently published values. Molecular weight distributions from Suwanee fulvate determined by both sizing techniques appeared to be in reasonable agreement. Ultrafiltration was used to separate organic colloids from low molecular weight components in sedimentary porewaters. Vertical profiles in the cores showed depletion of colloids near the sediment/water interface and accumulation of macromolecules with depth. Porewater colloids collected using glass fritted samplers appeared to confirm this trend, although lower values were recovered than when extracted by centrifugation methods.

Hydrophilic interaction chromatography (HILIC) is becoming increasingly popular for separation of polar samples on polar columns in aqueous-organic mobile phases rich in organic solvents (usually ACN). Silica gel with decreased surface concentration of silanol groups, or with chemically bonded amino-, amido-, cyano-, carbamate-, diol-, polyol-, or zwitterionic sulfobetaine ligands are used as the stationary phases for HILIC separations, in addition to the original poly(2-sulphoethyl aspartamide) strong cation-exchange HILIC material. The type of the stationary and the composition of the mobile phase play important roles in the mixed-mode HILIC retention mechanism and can be flexibly tuned to suit specific separation problems. Because of excellent mobile phase compatibility and complementary selectivity to RP chromatography, HILIC is ideally suited for highly orthogonal 2-D LC-LC separations of complex samples containing polar compounds, such as peptides, proteins, oligosaccharides, drugs, metabolites and natural compounds. This review attempts to present an overview of the HILIC separation systems, possibilities for their characterization and emerging HILIC applications in 2-D off-line and on-line LC-LC separations of various samples, in combination with RP and other separation modes. PMID:18428181

The concentration and distribution of uranium (U) in sediment samples from three boreholes recovered near radioactive waste storage tanks at Hanford, Washington, USA, were determined in detail using bulk and micro-analytical techniques. The source of contamination was a plume that contained an estimated 7000 kg of dissolved U that seeped into the subsurface as a result of an accident that occurred during filling of tank BX-102. The desorption character and kinetics of U were also determined by experiment in order to assess the mobility of U in the vadose zone. Most samples contained too little moisture to obtain quantitative information on pore water compositions. Concentrations of U (and contaminant phosphate-P) in pore waters were therefore estimated by performing 1:1 sediment-to-water extractions and the data indicated concentrations of these elements were above that of uncontaminated 'background' sediments. Further extraction of U by 8 N nitric acid indicated that a significant fraction of the total U is relatively immobile and may be sequestered in mobilization-resistant phases. Fine- and coarse-grained samples in sharp contact with one another were sub-sampled for further scrutiny and identification of U reservoirs. Segregation of the samples into their constituent size fractions coupled with microwave-assisted digestion of bulk samples showed that most of the U contamination was sequestered within the fine-grained fraction. Isotope exchange ({sup 233}U) tests revealed that {approx}51% to 63% of the U is labile, indicating that the remaining fund of U is locked up in mobilization-resistant phases. Analysis by Micro-X-ray Fluorescence and Micro-X-ray Absorption Near-Edge Spectroscopy ({mu}-XRF and {mu}-XANES) showed that U is primarily associated with Ca and is predominately U(VI). The spectra obtained on U-enriched 'hot spots' using Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLIFS) provide strong evidence for uranophane-type [Ca(UO{sub 2}){sub 2}(SiO{sub 3}OH){sub 2}(H{sub 2}O){sub 5}] and uranyl phosphate [Ca(UO{sub 2}){sub 2}(PO{sub 4}){sub 2}(H{sub 2}O){sub 10-12}] phases. These data show that disseminated micro-precipitates can form in narrow pore spaces within the finer-grained matrix and that these objects are likely not restricted to lithic fragment environments. Uranium mobility may therefore be curtailed by precipitation of uranyl silicate and phosphate phases, with additional possible influence exerted by capillary barriers. Consequently, equilibrium-based desorption models that predict the concentrations and mobility of U in the subsurface matrix at Hanford are unnecessarily conservative.

Soil sorption processes largely control the environmental fate of herbicides. Therefore, accuracy of sorption parameters is crucial for accurate prediction of herbicide mobility in agricultural soils. A combined experimental and statistical study was performed to investigate the small-scale spatial variability of sorption parameters for atrazine and dinoseb in soils and to establish the number of samples needed to provide a value of the distribution coefficient (K(d)) next to the mean, with a given precision. The study explored sorption properties of the two herbicides in subsurface samples collected from four pits distributed along a transect of an alluvial soil; two to four samples were taken at about 30 cm apart at each sampling location. When considering all the data, the distribution coefficients were found to be normally and log-normally distributed for atrazine and dinoseb, respectively; the CVs were relatively high (close to 50% for dinoseb and 40% for atrazine). When analyzed horizon by horizon, the data revealed distribution coefficients normally distributed for both herbicides, whatever the soil layer, with lower CVs. The K(d) values were shown to vary considerably between samples collected at very short distance (a few centimeters), suggesting that taking a single soil sample to determine sorption properties through batch experiments can lead to highly unrepresentative results and to poor sorption/mobility predictions. PMID:18689754

ABSTRACT: BACKGROUND: Next generation sequencing provides clinical research scientists with direct read out of innumerable variants, including personal, pathological and common benign variants. The aim of resequencing studies is to determine the candidate pathogenic variants from individual genomes, or from family-based or tumor/normal genome comparisons. Whilst the use of appropriate controls within the experimental design will minimize the number of false positive variations selected, this number can be reduced further with the use of high quality whole genome reference data to minimize false positives variants prior to candidate gene selection. In addition the use of platform related sequencing error models can help in the recovery of ambiguous genotypes from lower coverage data.DescriptionWe have developed a whole genome database of human genetic variations, Huvariome, determined by whole genome deep sequencing data with high coverage and low error rates. The database was designed to be sequencing technology independent but is currently populated with 165 individual whole genomes consisting of small pedigrees and matched tumor/normal samples sequenced with the Complete Genomics sequencing platform. Common variants have been determined for a Benelux population cohort and represented as genotypes alongside the results of two sets of control data (73 of the 165 genomes), Huvariome Core which comprises 31 healthy individuals from the Benelux region, and Diversity Panel consisting of 46 healthy individuals representing 10 different populations and 21 samples in three Pedigrees. Users can query the database by gene or position via a web interface and the results are displayed as the frequency of the variations as detected in the datasets. We demonstrate that Huvariome can provide accurate reference allele frequencies to disambiguate sequencing inconsistencies produced in resequencing experiments. Huvariome has been used to support the selection of candidate cardiomyopathy related genes which have a homozygous genotype in the reference cohorts. This database allows the users to see which selected variants are common variants (> 5% minor allele frequency) in the Huvariome core samples, thus aiding in the selection of potentially pathogenic variants by filtering out common variants that are not listed in one of the other public genomic variation databases. The no-call rate and the accuracy of allele calling in Huvariome provides the user with the possibility of identifying platform dependent errors associated with specific regions of the human genome. CONCLUSION: Huvariome is a simple to use resource for validation of resequencing results obtained by NGS experiments. The high sequence coverage and low error rates provide scientists with the ability to remove false positive results from pedigree studies. Results are returned via a web interface that displays location-based genetic variation frequency, impact on protein function, association with known genetic variations and a quality score of the variation base derived from Huvariome Core and the Diversity Panel data. These results may be used to identify and prioritize rare variants that, for example, might be disease relevant. In testing the accuracy of the Huvariome database, alleles of a selection of ambiguously called coding single nucleotide variants were successfully predicted in all cases. Data protection of individuals is ensured by restricted access to patient derived genomes from the host institution which is relevant for future molecular diagnostics. PMID:23164068

Purpose: To analyze the agreement between gross motor and hand function levels and clusters of functional performance in children with cerebral palsy (CP). Method}: The sample consisted of 129 children with CP aged 4 to 13~years. Children's gross motor and hand function were classified with the Gross Motor Classification System (GMFCS) and Manual Ability Classification System (MACS). Their daily functioning on self-care and mobility was assessed with the Pediatric Evaluation of Disability Inventory (PEDI). Cluster analyses grouped children with similar repertoires on self-care and mobility skills using the agglomerative hierarchical technique. The associations across self-care and mobility clusters with daily living skills were tested with Chi-Square tests. The level of agreement was quantified with the Kappa coefficient. Results: Four groupings of children's functional skills in self-care (R^{2}= 0.92) and mobility (R^{2}= 0.95) were identified. These groupings were associated with hand function (? ^{2}= 145.43; p ^{2}= 198.13; pfunctional classifications and functioning repertoires. The magnitude of agreement reinforces the importance of the concomitant use of functional classification and assessments. PMID:23023247

In plants, the phloem is the component of the vascular system that delivers nutrients and transmits signals from mature leaves to developing sink tissues. Recent studies have identified proteins, mRNA, and small RNA within the phloem sap of several plant species. It is now of considerable interest to elucidate the biological functions of these potential long-distance signal agents, to further our understanding of how plants coordinate their developmental programs at the whole-plant level. In this study, we developed a strategy for the functional analysis of phloem-mobile mRNA by focusing on IAA transcripts, whose mobility has previously been reported in melon (Cucumis melo cv. Hale's Best Jumbo). Indoleacetic acid (IAA) proteins are key transcriptional regulators of auxin signaling, and are involved in a broad range of developmental processes including root development. We used a combination of vasculature-enriched sampling and hetero-grafting techniques to identify IAA18 and IAA28 as phloem-mobile transcripts in the model plant Arabidopsis thaliana. Micro-grafting experiments were used to confirm that these IAA transcripts, which are generated in vascular tissues of mature leaves, are then transported into the root system where they negatively regulate lateral root formation. Based on these findings, we present a model in which auxin distribution, in combination with phloem-mobile Aux/IAA transcripts, can determine the sites of auxin action. PMID:22925478

BACKGROUND: Whey protein supplementation may augment resistance exercise-induced increases in muscle strength and mass. Further studies are required to determine whether this effect extends to mobility-limited older adults. The objectives of the study were to compare the effects of whey protein concentrate (WPC) supplementation to an isocaloric control on changes in whole-body lean mass, mid-thigh muscle cross-sectional area, muscle strength, and stair-climbing performance in older mobility-limited adults in response to 6 months of resistance training (RT). METHODS: Eighty mobility-limited adults aged 70-85 years were randomized to receive WPC (40g/day) or an isocaloric control for 6 months. All participants also completed a progressive high-intensity RT intervention. Sample sizes were calculated based on the primary outcome of change in whole-body lean mass to give 80% power for a 0.05-level, two-sided test. RESULTS: Lean mass increased 1.3% and 0.6% in the WPC and control groups, respectively. Muscle cross-sectional area was increased 4.6% and 2.9% in the WPC and control groups, respectively, and muscle strength increased 16%-50% in WPC and control groups. Stair-climbing performance also improved in both groups. However, there were no statistically significant differences in the change in any of these variables between groups. CONCLUSIONS: These data suggest that WPC supplementation at this dose does not offer additional benefit to the effects of RT in mobility-limited older adults. PMID:23114462

The utility of an automated 96-capillary electrophoresis instrument equipped with a laser-induced fluorescence detector was evaluated in the analysis of affinophoresis using concanavalin A and trypsin as models. Affinophores for concanavalin A and trypsin were prepared by coupling the affinity ligands, p-aminophenylmannoside and p-aminobenzamidine to soluble succinylpolylysine, respectively at a density of about 1/5 of the carboxyl groups. A dual buffer system, 60 mM borate-Na (pH 9.35) as an electrophoresis buffer and 60 mM 3-morpholinopropanesulfonic acid-Na (pH 7.35) containing 0.1% Tween 20 as a sample buffer, was employed to allow the interactions to occur at a physiological pH and also to maintain a high level of electroosmosis and reproducibility in the bare silica capillaries. The electrophoresis of the fluorophore-labeled proteins was carried out in the presence of affinophores, and changes in the mobility of the labeled proteins were analyzed in terms of the mobility moment, which represents the average mobility of the proteins, thus permitting the dissociation constants for the protein-affinophore interactions to be determined. The affinophoresis system was then used to evaluate the extent of binding of low molecular mass compounds based on the inhibition of the affinophoresis. In combination with the mobility moment analysis and the dual buffer system, the multi-capillary electrophoresis instruments proved to be useful for the analysis of biomolecular interactions by electrophoresis.   

In a media of finite viscosity, the Coulomb force of external electric field moves ions with some terminal speed. This dynamics is controlled by “mobility” - a property of the interaction potential between ions and media molecules. This fact has been used to separate and characterize gas-phase ions in various modes of ion mobility spectrometry (IMS) developed since 1970. Commercial IMS devices were introduced in 1980-s for field detection of volatile traces such as explosives and chemical warfare agents. Coupling to soft-ionization sources, mass spectrometry (MS), and chromatographic methods in 1990-s had allowed IMS to handle complex samples, enabling new applications in biological and environmental analyses, nanoscience, and other areas. Since 2003, the introduction of commercial systems by major instrument vendors started bringing the IMS/MS capability to broad user community. The other major development of last decade has been the differential IMS or “field asymmetric waveform IMS” (FAIMS) that employs asymmetric time-dependent electric field to sort ions not by mobility itself, but by the difference between its values in strong and weak electric fields. Coupling of FAIMS to conventional IMS and stacking of conventional IMS stages have enabled two-dimensional separations that dramatically expand the power of ion mobility methods.

Purpose: To describe changes in mobility measured with the Timed Up and Go test (TUG) from baseline to follow-up 9 years later, and to examine which of the demographic, physical performance and health variables measured at baseline were predictors of the TUG at follow-up in a sample of women aged 85 or older. Method: This prospective cohort study included 113 community-dwelling women with a baseline mean age of 79.5 years. TUG was measured at baseline and at follow-up. The following baseline measurements were used as predictors: demographics, step-climbing ability, functional reach, and health. Results: At follow-up 110 women had decline in the TUG. Mean TUG scores at baseline and at follow-up were 6.7 s (SD = 1.3) and 13.2 s (SD = 6.8) respectively. Higher age, higher BMI, poorer results on; functional reach, step-climbing and self-rated health were independent predictors of poorer TUG at the 9-year follow-up. Exhibiting sufficient strength to climb a step of 40?cm or more protected significantly against mobility decline. Improving balance measured by the functional reach test by 1?cm lowered the probability of major mobility decline by 7%. Conclusions: Our results suggest that to decrease the risk of mobility decline focus should be on strength, balance and nutrition. [Box: see text]. PMID:22931434

The mobility of Helium in polycrystalline uranium dioxide was studied by implanting samples with 3He ions at depths of approximately 1mm and at concentrations in the region of 0.1at.%. Samples were subsequently annealed at temperatures ranging between 700degreeC and 1100degreeC. Helium movement was then characterised using three different types of Nuclear Reaction Analysis (NRA) techniques based on the 3He(d,a)p reaction. The fraction of helium released from samples was measured during annealing at high temperature as a function of time. After each annealing sequence, helium depth profiles were obtained for each sample. In some cases, samples were characterised over small areas (60x60mm2), using a micrometre size deuteron beam. This enables the measurement of helium distributions at the su...

Spaced cleavage in limestone is commonly assumed to result from dissolution of carbonate minerals and passive concentration of other minerals in cleavage zones. More complicated processes are suggested by new element data acquired with the CSU XRF-macroprobe. Overlapping spot analyses were made along bed parallel traverses across cleavage zones in samples from the Twin Creek Formation (TCF) of southeast Idaho and the Poxono Island Formation (PIF) of eastern Pennsylvania. If calcite is the sole mobile phase, Ca should decrease as the other immobile elements increase proportionately. Though Ca is the only major element which consistently decreases in cleavage zones, changes in the relative proportions of the other elements indicate varying degrees of mobility. Al and Ti both increase in cleavage zones and maintain a constant ratio, suggesting immobile behavior. Because Al is more abundant than Ti, mobilities of other elements are determined relative to Al. Mg/Al and Fe/Al ratios are constant for PIF samples but show no systematic relationships in TCF samples, which have lower phyllosilicate contents. Si/Al ratios are relatively constant for most samples but in some PIF samples Si/Al ratios decrease in cleavage zones. This may be the result of dissolution of quartz or Si loss during phyllosilicate reactions. K/Al ratios are constant for limestones with average K/Al atomic ratios of 1/3 whereas samples lower K/Al ratios show increasing K/Al in cleavage zones. This suggests that the growth of new phyllosilicates in the K-poor cleavage zones causes preferential scavenging of potassium. In rocks with K/Al ratios of illite or muscovite, K appears to accumulate with Al by residual concentration. Thus, Al and Ti may be the only viable major element markers for calculating volume flux.

We analyze data from confocal microscopy experiments of a colloidal suspension to validate predictions of rapid sporadic events responsible for structural relaxation in a glassy sample. The trajectories of several thousand colloidal particles are analyzed, confirming the existence of rapid sporadic events responsible for the structural relaxation of significant regions of the sample, and complementing prior observations of dynamical heterogeneity. The emergence of relatively compact clusters of mobility allows the dynamics to transition between the large periods of local confinement within its potential energy surface, in good agreement with the picture envisioned long ago by Adam and Gibbs and Goldstein.

We report scanning Hall probe microscopy of highly underdoped superconducting YBa{sub 2}Cu{sub 3}O{sub 6+z} with T{sub c} ranging from 5 to 15 K which showed distinct flux bundles with less than one superconducting flux quantum ({Phi}{sub 0}) through the sample surface. The sub-{Phi}{sub 0} features occurred more frequently for lower T{sub c}, were more mobile than conventional vortices, and occurred more readily when the sample was cooled with an in-plane field component. We show that these features are consistent with kinked stacks of pancake vortices.

Purpose The objective of this research was to study heavy metal mobility and availability in sediment samples. A rapid diagnosis about metal behaviour was performed using the combination of several single-step extraction procedures and multi-way chemometric tools. Materials and methods Several single-step procedures for metal lixiviation?ammonium acetate, acetic acid, hydrochloric acid, ethylenediaminetetraacetic acid, trans-1,2-diaminocyclohexane-N,N,N?,N?-tetraacetic acid, nitrilotriacetic acid?with increasing extracting power were simultaneously applied to coastal surface sediment samples. Also, three certified reference materials for total metal concentrations were analysed. The metals studied were Cd, Cr, Cu, Pb and Zn because of their hazardous potential and related abundance in the ...

Abstract in english Capillary electrophoresis has become a well-established and routine-based separation technique. It is based on the differences between charged analyte mobility in aqueous or organic electrolytes. Its major limitation is the sensitivity due to small sample injection volumes and the narrow diameter of the capillaries, especially when UV detection is used. There are a number of ways to increase the concentration sensitivity. This report shows some on-line preconcentration st (more) rategies to perform it in free solution capillary electrophoresis that are based on manipulation of the analyte electrophoretic velocity during the sample introduction (stacking, field amplification and transient isotachophoresis).

A monocrystalline 18-carat yellow gold sample is deformed stepwise from 2% to 12% at room temperature. The mechanical loss spectrum is recorded and analysed. At low deformations the exponential high temperature background increases. At a critical deformation of 8% an intermediate temperature peak appears. Such peak typical of polycrystals is related to grain boundary sliding. The comparison of a polycrystal formed of low angle grain boundaries (LAGB) only, and samples deformed between 2% and 8% evidence the existence of an intermediate stage. The high temperature peak P3 characterizes the mobility of LAGB that is controlled by the movement of dislocations.

The preparation of components from a complex sample is a difficult task. The optimization of the separation and subsequent scale-up is usually carried out by trial and error. In this study, the relationship between retention parameters a and c for analytical and preparative separations was developed when the same solid adsorbent and mobile phase were used. The prediction and optimization of the preparative separation of a complex sample could be achieved by direct and simple conversion of the experimentally determined data from an analytical level. The novel method was successfully applied to optimize the separation of target compounds in traditional Chinese medicine (TCM).

A preconcentrator system and apparatus suited to human portable use wherein sample potentially containing a target chemical substance is drawn into a chamber and through a pervious screen. The screen is adapted to capture target chemicals and then, upon heating, to release those chemicals into the chamber. Chemicals captured and then released in this fashion are then carried to a portable chemical detection device such as a portable ion mobility spectrometer. In the preferred embodiment, the means for drawing sample into the chamber comprises a reversible fan which, when operated in reverse direction, creates a backpressure that facilitates evolution of captured target chemicals into the chamber when the screen is heated.

Total reflection X-ray fluorescence (TXRF) analysis is an established technique for trace-element analysis in various types of samples. Though expensive large-scale systems restricted the applications in the past, in this study the capability of a benchtop system for trace elemental analysis is reported. The suitability of this system for the mobile on-site analysis of heavy metal contaminated soils and sediments is reported as well as the possibilities and restrictions of TXRF for additional applications, including trace-element analysis of water, glass and biological samples.   

Mercury, zinc and copper contamination was evaluated in soils and fluvial sediments from an abandoned gold mining site at Descoberto Municipality (southern Minas Gerais State, Brazil). Metals bioavailability and potential mobility were studied through physical, chemical and mineralogical characterization, geoaccumulation indexes calculations, mercury speciation and determination of potentially bioavailable contents of zinc and copper. Values of pH were in the neutral range, while organic matter concentrations were very low. Mineralogical characterization, in the total samples, indicated the presence of quartz, kaolinite and gibbsite for all samples. Total mercury, zinc and cooper concentrations were higher than the limits recommended by Brazilian documents. Geoaccumulations indexes reveale...

Social science research is increasingly considering place when examining social programs and policies with a spatial component. A specific research challenge involving spatial policies is how to select a sample of individuals based on their geographic locations. This article illustrates the use of geographic information systems, tax parcels, and mail surveys to target residents in varied geographic areas. A provided example demonstrates how researchers obtained a sample of respondents living within one tenth of a mile of multiple registered sex offenders. The challenges of using tax parcels to obtain addresses for apartments and mobile home parks are also explored. (Contains 2 tables, 2 figures, and 4 notes.)

Contaminated sites must be analyzed as a source of hazardous compounds in the ecosystem. Contaminant mobility in the environment may affect sources of surface and groundwater, elevating potential risks. This study looked at the genotoxic potential of samples from a contaminated site on the banks of the Taquari River, RS, Brazil, where potential environmental problems had been identified (pentachlorophenol, creosote and hydrosalt CCA). Samplers were installed at the site to investigate the drainage material (water and particulate soil matter) collected after significant rainfall events. Organic extracts of this drained material, sediment river samples of the Taquari River (interstitial water and sediment organic extracts) were evaluated by the Salmonella/microsome assay to detect mutagenici...

The mean and fluctuating wall shear stress in turbulent air flows were measured. Hot wires were mounted at a fixed small distance from the wall and connected to a constant temperature anemometer and were operated at an overheat ratio of 35%. The mean skin friction was measured by a Preston tube. The pressure was determined using a digital micromanometer, directly read by a microcomputer. A calibration procedure was developed and the distortion of the probability density distribution due to the calibration curve nonlinearity was corrected. Experimental results in a flat plate boundary layer were obtained and compared to pulsed wire measurements.

In order to identify the causes of a fracture incident that occurred on the outer ring of a cylindrical roller bearing within an air blower motor, diverse characterization analyses were conducted in this study. Metallurgical structures and chemical compositions of the bearing?s matrix materials were inspected by metallographic microscope and photoelectric direct reading spectrometer. Scanning electron microscope and energy dispersive spectroscope were applied to detect the microscopic morphologies and micro-area compositions on the fracture surfaces and contact surfaces. The compositions and thermal properties of the lubrication medium, the grease, were also examined. Analysis results revealed that interaction between dry friction and impact both led by the degraded grease due to decomposi...

An evaluation has been made of the corrosiveness of selected wet residential building thermal insulation materials in contact with low carbon steel. Investigations were conducted both in wet insulations and in filtered leachates from insulations derived from thirteen cellulosic, three mineral fiber and four foam products. Potentiodynamic polarization measurements are reported from which the overall corrosion response was assessed and then the techniques of Tafel and polarization resistance analysis applied to estimate corrosion rates. Corrosion rates were also estimated electrochemically using a direct reading instrument which performs the rate calculation based on the polarization resistance principle. Direct determinations of corrosion rate were based on weight loss measurements.

A system for analysis of trace concentration of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

In single-column anion-exchange chromatography, the retention volume of some monovalent inorganic anions (Cl-, Br-, NO3-, NCS- and NO2-) were observed as a function of the pH of a mobile phase at a fixed concentration of 2-phenylmalonic acid or 1,4-benzenediacetic acid used as an eluent. The experimental retention volume of such an anion was decreased with an increase in the pH of a mobile phase, and was able to be described by the following equation taking account of anion-exchange equilibria of a sample anion with a hydrogen dicarboxylate ion (HE-) and with a dicarboxylate ion (E2-): ?1s/VR?[HE-] = 1/mTwKex1 + (2Ka2/mTw2Kex2)(VR?/?1s[H+]), where VR?, mT, w, Ka2, Kex1 and Kex2 are the adjusted retention volume of a given sample anion, the capacity for the anion-exchange of column packings and the weight of column packings packed into a separating column, the second acid-dissociation constant of the dicarboxylic acid used as an eluent, and equilibrium constants for the anion exchange of a sample anion with a monovalent hydrogen dicarboxylate ion and with a divalent dicarboxylate ion, respectively. The term ?1s, defined as Kas/([H+] + Kas), where Kas is the acid-dissociation constant of HX, is the mole fraction of a sample anion, X-, and is equal to 1 when using a strong acid anion as a sample anion.   

Agent technology is emerging as an important concept for the development of distributed complex systems. A number of mobile agent systems have been developed in the last decade. However, most of them were developed to support only Java mobile agents. In order to provide distributed applications with code mobility, this article presents a library, the Mobile-C library, that allows a mobile agent platform, Mobile-C, to be embeddable in an application to support mobile C/C++ codes carried by mobile agents. Mobile-C uses a C/C++ interpreter as its Agent Execution Engine (AEE). Through the Mobile-C library, Mobile-C can be embedded into an application to support mobile C/C++ codes carried by mobile agents. Using mobile C/C++ codes, it is easy to interface a variety of low-level hardware devices...

Mobile sources significantly contribute to ambient concentrations of airborne particulate matter (PM). Source apportionment studies for PM10 (PM vehicle combustion. Several source apportionment studies conducted in the United States suggested that gasoline combustion from mobile sources contributed more to ambient PM than diesel combustion. However, existing emission inventories for the United States indicated that diesels contribute more than gasoline vehicles to ambient PM concentrations. A comprehensive testing program was initiated in the Kansas City metropolitan area to measure PM emissions in the light-duty, gasoline-powered, on-road mobile source fleet to provide data for PM inventory and emissions modeling. The vehicle recruitment design produced a sample that could represent the regional fleet, and by extension, the national fleet. All vehicles were recruited from a stratified sample on the basis of vehicle class (car, truck) and model-year group. The pool of available vehicles was drawn primarily from a sample of vehicle owners designed to represent the selected demographic and geographic characteristics of the Kansas City population. Emissions testing utilized a portable, light-duty chassis dynamometer with vehicles tested using the LA-92 driving cycle, on-board emissions measurement systems, and remote sensing devices. Particulate mass emissions were the focus of the study, with continuous and integrated samples collected. In addition, sample analyses included criteria gases (carbon monoxide, carbon dioxide, nitric oxide/nitrogen dioxide, hydrocarbons), air toxics (speciated volatile organic compounds), and PM constituents (elemental/organic carbon, metals, semi-volatile organic compounds). Results indicated that PM emissions from the in-use fleet varied by up to 3 orders of magnitude, with emissions generally increasing for older model-year vehicles. The study also identified a strong influence of ambient temperature on vehicle PM mass emissions, with rates increasing with decreasing temperatures. PMID:21141431

We report on the design and application of a high-efficiency multiple-capillary liquid chromatography (LC) system for high-throughput proteome analysis. The multiple-capillary LC system was operated at the pressure of 10,000 psi using commercial LC pumps to deliver the mobile phase and newly developed passive feedback valves to switch the mobile phase flow and introduce samples. The multiple-capillary LC system was composed of several serially connected dual-capillary column devices. The dual-capillary column approach was designed to eliminate the time delay for regeneration (or equilibrium) of the capillary column after its use under the mobile phase gradient condition (i.e. one capillary column was used in separation and the other was washed using mobile phase A). The serially connected dual-capillary columns and ESI sources were operated independently, and could be used for either''backup'' operation or with other mass spectrometer(s). This high-efficiency multiple-capillary LC system uses switching valves for all operations and is highly amenable to automation. The separations efficiency of dual-capillary column device, optimal capillary dimensions (column length and packed particle size), suitable mobile phases for electrospray, and the capillary re-generation were investigated. A high magnetic field (11.5 tesla) Fourier transform ion cyclotron resonance (FTICR) mass spectrometer was coupled on-line with this high-efficiency multiple-capillary LC system through an electrospray ionization source. The capillary LC provided a peak capacity of {approx}600, and the 2-D capillary LC-FTICR provided a combined resolving power of > 6 x 10 7 polypeptide isotopic distributions. For yeast cellular tryptic digests, > 100,000 polypeptides were typically detected, and {approx}1,000 proteins can be characterized in a single run.

We investigated the influence of the thickness of the AlN interlayer for InAlN/GaN and InAlN/AlGaN/GaN heterostructures. The AlN thickness strongly affects the surface morphology and electron mobility of the InAlN/GaN structures. The rms roughness of the surface increases from 0.35 to 1.2nm with increasing AlN thickness from 0 to 1.5nm. Large pits are generated when the AlN is thicker than 1nm. The highest electron mobility of 1470cm2/V·s is obtained for a 0.75-nm-thick AlN interlayer. The mobility, however, becomes lower with increasing deviation from 0.75nm. It is only 200cm2/V·s for the 0-nm thick AlN. Inserting AlGaN between AlN and InAlN suppresses the influence of the AlN interlayer thickness. A smooth surface with rms roughness of 0.35nm is obtained for all samples with 0-1.5-nm-thick AlN. The electron mobility ranges from 1000 to 1690cm2/V·s. The variation is smaller than that for InAlN/GaN. We fabricated field effect transistors (FETs) with gate length of 2µm. The electron mobility in the access region affects the transconductance (gm) of FETs. As a results, the influence of the AlN thickness for InAlN/GaN FETs is larger than that for InAlN/AlGaN/GaN FETs, which reduces gate leakage current. The transconductance varies from 93 to 235mS/mm for InAlN/GaN FETs. In contrast, it varies from 180 to 230mS/mm for InAlN/AlGaN/GaN FETs. These results indicate that the InAlN/AlGaN/GaN heterostructures could lead to the development of GaN-based FETs.   

The effect of x-ray irradiation on polarization switching properties of a glycine phosphite (GPI) single crystal is investigated using the Merz technique. GPI undergoes a paraelectric to ferroelectric phase transition at 224.7 K. Switching studies were performed in the temperature range of 173-221 K with the applied field varying from 1.1 to 4.9 kV/cm. X-ray irradiation causes an increase in the threshold field below which switching could not occur. The activation energy for the domain wall motion is found to increase with irradiation from 0.12 eV for a pristine sample to 0.34 eV after irradiating it for 20 min. The temperature dependence of domain wall mobility shows an unusual behavior with the radiation dosage. The calculated domain wall mobility increases with the exposure time, which is contrary to expectation. This apparent increase in mobility with exposure time is attributed to the creation of a large number of radiation induced defects, identified as PO{sub 3}{sup 2-} radicals, resulting in the loss of effective switchable volume of the sample.

Single- and double-wall carbon nanotubes (CNTs) having dimethylanilino (DMA) units covalently attached to the external graphene wall have been prepared by the reaction of the dimethylaminophenylnitronium ion with the corresponding CNT. The samples have been characterized by Raman and XPS spectroscopies, thermogravimetry, and high-resolution transmission electron microscopy in which the integrity of the single or double wall of the CNT and the percentage of substitution (one dimethylanilino group every 45 carbons of the wall for the single- and double-wall samples) has been determined. Nanosecond laser flash photolysis has shown the generation of transients that has been derived from the charge transfer between the dimethylanilino (as the electron donor) to the CNT graphene wall (as the electron acceptor). Importantly, the lifetime of the double-wall CNT is much shorter than that monitored for the single-wall CNT. Shorter-lived transients were also observed for the pentyl-esterified functionalized double-wall CNT with respect to the single-wall analogue in the presence of hole (CH(3) OH) and electron quenchers (O(2) , N(2) O), which has led to the conclusion that the inner, intact graphene wall that is present in double-wall CNT increases the charge mobility significantly, favoring charge recombination processes. Considering the importance that charge mobility has in microelectronics, our finding suggests that double-wall CNT or two-layer graphene may be more appropriate to develop devices needing fast charge mobility. PMID:23136036

Practically since their availability, a succession of audiovisual recording devices (e.g., reel-to-reel, VCRs, PCs) has been used to capture language samples, and myriad playback and broadcast devices (e.g., phonographs, radios, televisions) have provided access to authentic speech samples. The espousal of audiolingual theory in the 1950s brought the widespread use of the language laboratory in educational settings (Salaberry, 2001). Influenced by behaviorism, the lab was progressively replaced in the 1960s by drill-based computer-assisted instruction, which decades later was itself surpassed by a more intelligent, interactive and multimedia computer-assisted language learning. The popular acceptance of the Internet in the 1990s advanced the development of computer-mediated communications. As technologies continue to evolve, so does their propensity to shrink in size. "Other technologies that hold the capacity for language learning include PDAs, multimedia cellular phones, MP3 players, DVD players, and digital dictionaries" (Zhao, 2005, p. 447). Such portable media--referred to in popular and scholarly literature as mobile, wireless, handheld or nomadic--are now social staples. Mobile learning, or m-learning, is a burgeoning subdivision of the e-learning movement, further evidenced by European initiatives such as m-learning and Mobilearn. This paper discusses MALL (mobile assisted language learning) applications and reviews their benefits and challenges.

A method has been developed by Argonne National Laboratory to identify and quantify As(III), As(V), and organoarsenic compounds in environmental samples. A arsenic species were separated by reversed-phase, ion-pairing, HPLC using a microbore Inertsil-ODS{trademark} column. Only 1 {micro}L of sample was injected on the column, and the mobile phase flow rates were typically on the order of 40 {micro}L/min. The HPLC mobile phase was a mixture of methanol and tetrabutylammonium hydroxide (TBAH), and the column effluent was introduced into an ICP-mass spectrometer using direct injection nebulization. Detection limits of less than 1 pg As (as injected on the column) were easily obtained for each arsenic species. The effect of changes in mobile phase composition and ICP-MS conditions will be described, as well as quality control measures, e.g., the use of surrogates, internal standards, and matrix spikes. Precision and accuracy information will be presented from the analysis of aqueous standards and soil extracts that were spiked with arsenic oxide [As(III)], sodium arsenate [As(V)], dimethylarsinic acid (DMAA), or chlorovinyl arsenious acid (CVAA). The authors believe that these data demonstrate the utility of this technique for the sensitive determination of arsenic species present in water or soil.

New materials, suitable for the application in reversed phase liquid chromatography and fuel cell membranes, were characterized regarding their structure and dynamic properties using solid-state and suspended-state NMR spectroscopy. Both methods were found to be suitable to study the dynamic behaviour, the first to observe intrinsic mobilities of phosphonic acids, the second to monitor interaction processes taking place in a chromatography-like system. Several phosphonic acids, which are promising materials for high temperature fuel cell membranes, were investigated with respect to proton mobility and transport applying various solid-state NMR methods. In addition, water uptake and its effects on anhydride formation were studied on samples that were equilibrated with saturated salt solutions. For PVPA substantial, reversible anhydride formation was found, while MePA did not show condensation. These results show that the relation between hydrogen bond strength and proton mobility is complex. In particular, this work demonstrates that the application of simple 1D 1H and 2H NMR experiments provides easy access to information about proton/deuteron mobility on short time scales, needed for an identification of materials with high intrinsic proton conductivities. Stationary phases for reversed phase liquid chomatography were characterized by solid-state NMR spectroscopy, and their influence on different analytes was studied using suspendedstate HR-MAS NMR spectroscopy. Suspended-state HR-MAS NMR spectroscopy showed to be suitable to model the separation process of analytes on chromatographic sorbents. For this, the stationary phase was suspended in a solution of analyte dissolved in mobile phase. MePhSucc showed a peak doubling of the CH2 group in presence of monomeric C18 phase, leading to the coexistence of a narrow and a broadened peak. Thus, the dynamic interactions of MePhSucc towards the stationary phase, and under the influence of the mobile phase, could be directly observed using 1H HR-MAS NMR spectroscopy. Changing the mobile phase concentration and composition caused a shift of the broadened peak towards the narrow CH2 signal, resulting in the fusion of both. These effects were explained by two different theories, one of which substantiates with polarity differences, the other with the winding up of the C18 alkyl chains. Separating interactions were also investigated using the suspended-state STD HR-MAS NMR technique that unveiled the part of analyte molecule interacting with the chromatographic sorbent. Furthermore, the molecular recognition of a particulate and a monolithic MIP towards their respective template molecules was investigated using 1H STD HR-MAS NMR spectroscopy. The obtained data proved superiority of the respective MIP over the NIP, and definite knowledge of the interaction site at the analyte molecules could be gained. Differences between specific and non-specific binding could be observed. (orig.)

A 13C-detected N H dipolar coupling technique is introduced for uniaxially mobile membrane proteins for orientation determination using unoriented samples. For proteins undergoing rigid-body uniaxial rotation in the lipid bilayer, the intrinsic equality between the dipolar coupling constants measured in unoriented samples and the anisotropic coupling measured in static oriented samples has been shown recently. Here, we demonstrate that the orientation-sensitive backbone N H dipolar couplings can be measured with 13C detection using 2D and 3D MAS correlation experiments, so that maximal site resolution can be achieved and multiple orientational constraints can be extracted from each experiment. We demonstrate this technique on the M2 transmembrane peptide of the influenza A virus, where the N H dipolar couplings of various residues fit to a dipolar wave for a helical tilt angle of 37°, in excellent agreement with data obtained from singly 15N-labeled samples.

The Dutch feed evaluation system for ruminants uses assumptions and regression equations to estimate the intestinal digestibility of crude protein (CP), neutral detergent fibre (NDF) and starch. These assumptions and equations are based on many different studies, obtained over a very long period. The objective of this study was to develop a unique dataset on the ruminal degradability and the postruminal digestibility of CP, NDF (aNDFom, amylase neutral detergent fibre organic matter basis) and starch in maize and grass silages, using the mobile nylon bag technique. Twenty samples of maize silage and 20 samples of grass silage were used. The samples were selected to represent a broad range in digestibility and chemical composition. Prior to the intestinal incubations, samples were incubated...

A new method was developed for the determination of trace anions in chloride-rich samples via ion chromatography by reducing the concentration of chloride ions using silver oxide as a precipitating reagent. In this method the sample pretreatment was started with the addition of silver oxide powder followed by 8 min of stirring and 2 min of centrifugation at a speed of 1500 rpm. The supernatant was diluted with a 1:10 ratio using deionized water and filtered with a 0.22 mm NC filter. All the samples were analyzed in a Dionex ICS-2500 system with an ED50 electrochemical detector in conductivity mode. On the basis of Dionex IonPac AG18 (50 mmx2 mm) and AS18 (250 mmx2 mm) columns, 25 mL sample filtrate was eluted isocratically with a mobile phase of 32 mmol/L NaOH at a flow rate of 0.25 mL/min...

Data is examined for volatile/mobile Ag, As, Au, Bi, Cd, Co, Cs, Cu, Ga, In, Rb, Sb, Se, Te, Tl and Zn in exterior and/or interior samples of four Antarctic meteorites from the Allan Hills (ALH): A77005 (unique achondrite); A77257 (ureilite); A77278 (L3); A77299 (H3). Exterior samples reflect contamination and/or leaching by weathering but trace element (ppm-ppt) contents in interior samples seem reasonable for representatives of these rare meteoritic types. The A77005 achondrite is shown to be related to shergottites; other samples extend compositional ranges previously known for their groups or types. With suitable precautions, Antarctic meteorite finds yield trace element data as reliable as those obtained from previously known falls.

We report results of torsional oscillator (TO) experiments on solid 4He at temperatures above 1?K. We have previously found that single crystals, once disordered, show some mobility (decoupled mass) even at these rather high temperatures. The decoupled mass fraction with single crystals is typically 20?30%. In the present work we performed similar measurements on polycrystalline solid samples. The decoupled mass with polycrystals is much smaller, ?1%, similar to what is observed by other groups. In particular, we compared the properties of samples grown with the TO?s rotation axis at different orientations with respect to gravity. We found that the decoupled mass fraction of bcc samples is independent of the angle between the rotation axis and gravity. In contrast, hcp samples showed a sig...

This work presents a study of human hair as a bio-indicator for detection of heavy metals as part of environmental health surveillance programs project to develop a subject of interest in the biomedical and environmental sciences. A total of 34 hair samples were analyzed that consisting of 29 samples from sanitation workers and five samples from students. The hair samples were prepared and treated in accordance to the International Atomic Energy Agency (IAEA) recommendations. The concentrations of heavy metals were analyzed using the energy dispersive X-ray fluorescence (EDXRF) technique by X-50 Mobile X-ray Fluorescence (XRF) at Oceanography Institute, Universiti Malaysia Terengganu. The performance of EDXRF analyzer was tested by Standard Reference Material (SRM 2711) Montana Soil which ...

Lithium stannate (Li2SnO3) has been prepared by solution evaporation method. The precursor obtained is sintered at 800?C for 5, 6, and 7?h, respectively. X-ray diffractogram confirmed that the sample obtained after sintering is Li2SnO3. The pelletized Li2SnO3 after heating at 500??C for 3?h is used for electrochemical impedance spectroscopy characterization. Impedance measurements have been carried out over frequency range from 50?Hz to 1?MHz and temperature range from 563 to 633?K. The conductivity?temperature relationship is Arrhenian. Several important parameters such as activation energy, ionic hopping frequency and its rate, carrier concentration term, mobile ion number density, ionic mobility, and diffusion coefficient have been determined. The characteristics of log conductivity and...