5,472 research outputs found

    Precision gage measures ultrahigh vacuum levels

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    Ionization gage in which internally generated X rays are minimized is described. This gage permits the measurement of gas pressures in ultrahigh systems of micro-pico torr /10-18/

    Migration of latent fingermarks on non-porous surfaces:observation technique and nanoscale variations

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    Latent fingermark morphology was examined over a period of approximately two months. Variation in topography was observed with atomic force microscopy and the expansion of the fingermark occurred in the form of the development of an intermediate area surrounding the main fingermark ridge. On an example area of a fingermark on silicon, the intermediate region exists as a uniform 4nm thick deposit; on day 1 after deposition this region extends approximately 2µm from the edge of the main ridge deposit and expands to a maximum of ~ 4µm by day 23. Simultaneously the region breaks up, the integrity is compromised by day 16, and by day 61 the area resembles a series of interconnected islands, with coverage of approximately 60%. Observation of a similar immediate area and growth with time on surfaces such as Formica was possible by monitoring the mechanical characteristics of the fingermark and surfaces though phase contrast in tapping mode AFM. The presence of this area may affect fingermark development, for example affecting the gold distribution in vacuum metal deposition. Further study of time dependence and variation with donor may enable assessment of this area to be used to evaluate the age of fingermarks

    The particulars about particulates : metal exposure and self-regulation of children living near coal ash.

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    The use of coal combustion for electricity and the storage of coal combustion by-products known as coal ash occur across the United States and around the world. The most abundant type of coal ash, fly ash, contains small particles with metals, some of which are known neurotoxins. Fly ash is currently stored in open-air landfills and surface impoundments that allow fugitive dust to escape into surrounding communities, potentially exposing children to small neurotoxic particles. This dissertation uses preliminary data from a larger cross-sectional study to investigate the relationship between particulate matter exposure, metal exposure, and problems with self-regulation. Recruitment of this study sample, the first 78 of 300 participants, occurred between September 2015 and December 2016. Exploratory spatial data analysis was used to assess how living near fly ash storage is related to indoor particulate matter concentration and exposure to metals. Linear regression models were used to assess the relationship between fly ash exposure, particulate matter exposure, and self-regulation. Furthermore, Bayesian kernel machine regression for variable selection and regression models were used to explore the relationship between metal concentration in particulate matter and children’s self-regulation. The most abundant metal found in fly ash particles was aluminum. The concentration of aluminum in indoor PM10 was significantly related to distance from the fly ash landfills and an Environmental Justice Index used to identify vulnerable populations. In addition, children with higher aluminum exposure were found to perform more poorly on the Behavioral Assessment and Research System Continuous Performance and Selective Attention Tests, indicating general inattention problems. These results are based on a small preliminary sample and should therefore be interpreted with caution. Future studies will further investigate the relationship between aluminum exposure, children’s metal body burden, and cognitive control

    Coal ash and children\u27s sleep : a community-based study.

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    Kentucky is the fifth largest producer of coal ash, a by-product of coal combustion. The small spherical coal ash particles contain heavy metals like arsenic, lead, mercury, and cadmium. Coal ash is currently classified as nonhazardous by the EPA, which allows it to be stored in open-air impoundments near low-income communities. The primary object of the study is to determine the prevalence of sleep disruptive behaviors in children exposed to coal ash, compared to a group of demographically similar non-exposed children. Parents or guardians from five neighborhoods surrounding a coal ash storage facility, and one non-exposed community, participated in a cross-sectional survey about the health and sleep of children living in their home. Delay in sleep onset (p= 0.007), frequent night awakenings (p= 0.0001), teeth grinding (p= 0.03), lip smacking (p=0.006), snoring (p= 0.002), and complaint of leg cramps while resting (p= 0.0004) were significantly greater in the exposed group compared to the non-exposed group. When controlling for both health and environmental factors, the odds of frequent night awakenings were significantly greater in the exposed group compared to the non-exposed group (OR= 6.9, CI= 2.2-21). It is important to further evaluate the association between frequent night awakenings and coal ash exposure because of the potential long-term cognitive and biological impacts on children

    A Case of Hemorrhagic Pleurisy; Permanent Drainage; Recovery

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    Direct evidence for the magnetic ordering of Nd ions in NdFeAsO by high resolution inelastic neutron scattering

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    We investigated the low energy excitations in the parent compound NdFeAsO of the Fe-pnictide superconductor in the μ\mueV range by a back scattering neutron spectrometer. The energy scans on a powder NdFeAsO sample revealed inelastic peaks at E = 1.600 ±0.003μ \pm 0.003 \mueV at T = 0.055 K on both energy gain and energy loss sides. The inelastic peaks move gradually towards lower energy with increasing temperature and finally merge with the elastic peak at about 6 K. We interpret the inelastic peaks to be due to the transition between hyperfine-split nuclear level of the 143^{143}Nd and 145^{145}Nd isotopes with spin I=7/2I = 7/2. The hyperfine field is produced by the ordering of the electronic magnetic moment of Nd at low temperature and thus the present investigation gives direct evidence of the ordering of the Nd magnetic sublattice of NdFeAsO at low temperature

    Incoherent dynamics in neutron-matter interaction

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    Coherent and incoherent neutron-matter interaction is studied inside a recently introduced approach to subdynamics of a macrosystem. The equation describing the interaction is of the Lindblad type and using the Fermi pseudopotential we show that the commutator term is an optical potential leading to well-known relations in neutron optics. The other terms, usually ignored in optical descriptions and linked to the dynamic structure function of the medium, give an incoherent contribution to the dynamics, which keeps diffuse scattering and attenuation of the coherent beam into account, thus warranting fulfilment of the optical theorem. The relevance of this analysis to experiments in neutron interferometry is briefly discussed.Comment: 15 pages, revtex, no figures, to appear in Phys. Rev.

    The Friends of Hospice Thrift Store Marketing Plan

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    The Friends of Hospice Thrift Shop is preparing to launch an expansion of their business by obtaining more square footage at their current location to develop a “boutique” atmosphere, with the goal of attracting more customers. Although the rental cost is quoted as being greater than the current cost of renting the space presently in use, it is hoped that the additional space will pay for itself by bringing in greater revenue. Furthermore, a trial-based reduced rate will be proposed in order to determine the success level of this expansion project, and whether profits will cover expenses to justify a permanent increase in the shop’s dimensions. It is believed that this growth will prove worthwhile because more people are frequenting thrift shops seeking low cost options due the status of the economy. At the Hospice Thrift Store, customers can find inexpensive, quality goods. This is especially appealing to low income clients, like senior citizens, who quantitatively comprise the majority of the current target market. The up-and-coming new generation of teenagers and twenty-something’s is another market worthy of targeting because of the products they seek. The new boutique can be marketed to this new demographic, who seek the new trend of vintage style. The shop relies on some newspaper advertising as well as word-of-mouth from loyal, satisfied customers. The ‘Heart in a Shopping Cart’ logo inspires everyone to feel welcome in the shop’s atmosphere and feel good about their purchase, knowing the funds go to a good cause. The primary marketing objective is to achieve steady profit growth over the course of the sixth month trial period. Upon presenting this marketing plan in May 2014, concepts have been implemented over the long term. Key words: The Friends of Hospice Thrift Shop, Marketing Plan, retail, marketing objective, consignment shop, advertising, boutique

    “If You Are Old Enough to Die for Your Country, You Should Be Able to Get a Pinch of Snuff”: Views of Tobacco 21 Among Appalachian Youth

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    Background: Multiple strategies have been utilized in attempts to decrease the prevalence of youth tobacco use. One strategy, raising the minimum legal sale age (MLSA) of tobacco products to 21, known as Tobacco 21, has recently gained popularity. Tobacco 21 legislation targets youth tobacco use by obstructing two main sources of youth tobacco products: stores and older friends. Although these sources are the most common for youth across the nation, regional differences have not been explored. Further, youth perspectives about raising the tobacco MLSA have not been considered. Youth may help identify potential challenges to implementing tobacco control measures, as well as suggest alternatives for intervention, thus helping to shape successful tobacco control policies. Study Aim: This study aimed to 1) examine youth perspectives on raising the tobacco minimum legal sale age to 21 and 2) identify common sources of tobacco products among middle and high school students living in rural, low-income Appalachian communities. Methods: A cross-sectional survey about perceptions and use of tobacco products was conducted with students in the Appalachian regions of Kentucky and North Carolina (N=426). Questions were asked concerning perspectives on the effect of Tobacco 21 implementation. Descriptive statistics characterized participants by Tobacco 21 perspectives. Participants were given the opportunity to further expand upon their opinions in an open-ended format. Results: The majority (58.7%) of participants responded that the same number of youth would use tobacco if the legal purchase age were raised, followed by responses that fewer would use (28.9%) and more would use (12.4%). Significant differences emerged based on tobacco use status (p\u3c.05), friends’ tobacco use (p\u3c.001), and whether participants identified family members as sources of youth tobacco products (p=.047). When given the opportunity to expand upon their views concerning the implementation of Tobacco 21 laws in their communities, many respondents cited poor enforcement of tobacco MLSAs at stores, continued access to tobacco products from family members and friends, and the overall abundance of tobacco in their communities as potential barriers to the successful implementation. Conclusion: Fewer than one-third of participants believed that Tobacco 21 legislation would succeed in reducing the prevalence of youth tobacco use. Perspectives on the effect of Tobacco 21 legislation were related to personal tobacco use, exposure to tobacco users, and beliefs that family members provide tobacco products to youth. Open-ended responses identify potential obstacles in implementing Tobacco 21 legislation in Appalachia. Future research should attempt to include youth perspectives when designing and implementing tobacco control policies and examine family members as sources of tobacco products for youth

    The recoverability of fingerprints on paper exposed to elevated temperatures - Part 2: natural fluorescence

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    Previous work by the authors [1] investigated the recoverability of fingerprints on paper which had been exposed to elevated temperatures by comparing various chemical enhancement techniques (ninhydrin, 1,8-diazafluoren-9-one (DFO), and physical developer (PD)). During that study, it became apparent, as a consequence of observations made in operational work [2], that fingerprints on paper subjected to 150˚C fluoresced under examination with green light of waveband 473-548nm with a 549nm viewing filter. This work examined the three types of prints (eccrine, sebaceous, and ungroomed) after 20 min exposure to the temperature range 110˚C to 190˚C (in 10˚C increments) and found that the eccrine fingerprints fluoresced more brightly. This indicated that it was a component of the eccrine deposit which was causing the fluorescence. Luminance measurements found that the maximum fluorescence was experienced at 170˚C on both types of paper. As a consequence, eccrine heat-treated fingerprints were viewed under violet-blue (350-469nm), blue (352-509nm), and green light (473-548nm) which indicated that the greatest luminance intensities were obtained under blue light and the smallest under green light. In order to determine what component of the eccrine fingerprint was causing this fluorescence, five of the most prevalent amino acids (alanine, aspartic acid, glycine, lysine, and serine) [3-4] were exposed to this temperature range. The luminance measurements were taken under exposure to the green light in order for the minimum fluorescence to be observed, with an assumption that blue-violet or blue illumination will provide brighter fluorescence in practice. The results indicated that four of the amino acids are behaving similarly across the temperature range, but with slightly different luminance measurements, but all are exhibiting some level of fluorescence. Thermal degradation products of alanine and aspartic acid have been suggested by Richmond-Aylor et al. [5]. The structure of these thermal degradation products is cyclic in nature, and as such, there is a possibility that two of these products would fluorescence. Sodium chloride and urea were also exposed to the temperature range and they also fluoresced to some extent. This work shows that eccrine fingerprints that have been exposed to temperatures of between 130˚C to 180˚C will fluoresce under violet-blue, blue, and green light. This level of fluorescence for ungroomed fingerprints is much less but this will be dependent on the individual, the more eccrine the deposit, the stronger the fluorescence. This work shows that the amino acids, sodium chloride, and urea present in fingerprint deposits are all contributing to the fluorescence of the print, but may not be the sole contributor as other eccrine components have not yet been tested
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