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Excessive rainfall and dam failures resulted in floodwater contaminating our public water supply. The endotoxin risk in the contaminated water created challenges in recovery of sterile processing for our surgical equipment. Recovery plans should include a potable water source and a method to connect it to the required location. We share our solution of plumbing our sterile processing equipment to tanker-transported potable water sources. (Disaster Med Public Health Preparedness. 2018; 12: 415–418)
Issues in traditional cross-section sampling of paintings and other cultural artifacts with a scalpel, such as crumbling, delamination and paint compression, can deter conservators from sampling fragile paint layers. Often, such sampling carries the risk of causing further damage from a scalpel, which outweighs the benefits of scientific investigation. Here, we show that femtosecond lasers offer a viable alternative to obtaining cross-sections with minimal damage to the surrounding artwork. A Regenerative Ti:Sapphire amplifier system with a pulse duration of 70 femtoseconds, a few milliwatts of average power and a repetition rate of 1 kHz (1000 pulses/sec) was used for the study. Tests were performed on oil paintings ranging in age from the 19th century to late 20th century. Effective settings were determined to be 2 mW of power at a speed of 10mm/sec using an 800nm laser. Preliminary results suggest femtosecond lasers could be a viable alternative for obtaining paint cross-sections when traditional sampling methods cause unnecessary damage to fragile materials.
Bystander cardiopulmonary resuscitation (CPR) improves survival after prehospital cardiac arrest. While community CPR training programs have been implemented across the US, little is known about their acceptability in non-US Latino populations.
The purpose of this study was to identify barriers to enrolling in CPR training classes and performing CPR in San José, Costa Rica.
After consulting 10 San José residents, a survey was created, pilot-tested, and distributed to a convenience sample of community members in public gathering places in San José. Questions included demographics, CPR knowledge and beliefs, prior CPR training, having a family member with heart disease, and prior witnessing of a cardiac arrest. Questions also addressed barriers to enrolling in CPR classes (cost/competing priorities). The analysis focused on two main outcomes: likelihood of registering for a CPR class and willingness to perform CPR on an adult stranger. Odds ratios and 95% CIs were calculated to test for associations between patient characteristics and these outcomes.
Among 371 participants, most were male (60%) and <40 years old (77%); 31% had a college degree. Many had family members with heart disease (36%), had witnessed a cardiac arrest (18%), were trained in CPR (36%), and knew the correct CPR steps (70%). Overall, 55% (95% CI, 50-60%) indicated they would “likely” enroll in a CPR class; 74% (95% CI, 70-78%) would perform CPR on an adult stranger. Cardiopulmonary resuscitation class enrollment was associated with prior CPR training (OR: 2.6; 95% CI, 1.6-4.3) and a prior witnessed cardiac arrest (OR: 2.0; 95% CI, 1.1-3.5). Willingness to perform CPR on a stranger was associated with a prior witnessed cardiac arrest (OR: 2.5; 95% CI, 1.2-5.4) and higher education (OR: 1.9; 95% CI, 1.1-3.2). Believing that CPR does not work was associated with a higher likelihood of not attending a CPR class (OR: 2.4; 95% CI, 1.7-7.9). Fear of performing mouth-mouth, believing CPR is against God’s will, and fear of legal risk were associated with a likelihood of not attending a CPR class and not performing CPR on a stranger (range of ORs: 2.4-3.9).
Most San José residents are willing to take CPR classes and perform CPR on a stranger. To implement a community CPR program, barriers must be considered, including misgivings about CPR efficacy and legal risk. Hands-only CPR programs may alleviate hesitancy to perform mouth-to-mouth.
SchmidKM, Mould-MillmanNK, HammesA, KroehlM, Quiros GarcíaR, Umaña McDermottM, LowensteinSR. Barriers and Facilitators to Community CPR Education in San José, Costa Rica. Prehosp Disaster Med. 2016;31(5):509–515.
We use the underlying data of the IMPLAN Pro 3.0 regional economic simulation model to estimate the current economic contribution of Michigan's local food system and explore the chain of transactions giving rise to consumption of locally sourced goods from producer to processor to consumption. The proposed methodology includes both unprocessed and processed foods in the estimation of the local food system's economic value. The model also provides a replicable and consistent approach to estimating the value of local food systems within regional and state economies.
In August 2008, a large outbreak of Shiga toxin-producing Escherichia coli (STEC) O111:NM infections associated with a buffet-style restaurant in rural Oklahoma was identified. A case-control study of restaurant patrons and a retrospective cohort study of catered event attendees were conducted coupled with an environmental investigation to determine the outbreak's source and mode of transmission. Of 1823 persons interviewed, 341 (18·7%) met the outbreak case definition; 70 (20·5%) were hospitalized, 25 (7·3%) developed haemolytic uraemic syndrome, and one died. Multiple food items were significantly associated with illness by both bivariate and multivariate analyses, but none stood out as a predominant transmission vehicle. All water, food, and restaurant surface swabs, and stool cultures from nine ill employees were negative for the presence of Shiga toxin and E. coli O111:NM although epidemiological evidence suggested the outbreak resulted from cross-contamination of restaurant food from food preparation equipment or surfaces, or from an unidentified infected food handler.
We demonstrate a vacuum lithography process which uses a finely focused Ga ion beam to write the pattern which is then transferred to the InP pattern by low energy dry etching. Surface steps on the order of 1000-2000A in height, and lateral resolution limited only by size of the ion beam, can be efficiently prepared using moderate Ga ion fluences. The surfaces prepared by this process are damage free and suitable for epitaxial overgrowth. GaInAs/InP heterostructures grown on in-situ patterned substrates show excellent morphology and high luminescence efficiency.
The lattice mismatch of single-crystal epitaxial nickel disilicide of orientation A and B on Si(111) has been measured in and out of the <111> growth direction using a four-circle X-ray diffractometer. In both directions the mismatch of the as-grown B-type film was found to be larger than for the A-type; after annealing at 800°C the mismatch of the A-type approached the value of the B-type, while the latter remained the same. This result suggests that the B-type NiSi2 film has relaxed more during growth than the A-type which can only be relieved by subsequent annealing. This difference in A- and B-type mismatch is correlated with TEM studies. The combined results provide evidence that the growth of either A or B orientation is strongly affected by the nature and density of the misfit dislocations.
At the Savannah River Plant (SRP), a process has been developed for immobilizing high-level radioactive waste in a borosilicate glass. The waste is currently stored as soluble salts and insoluble solids. Insoluble waste as stored requires further processing before vitrification is possible. The processes required have been developed and demonstrated with actual waste. They include removal of aluminum in some waste, washing soluble salts out of the insoluble waste, and mercury stripping. Each of the processes and the results with actual SRP waste will be discussed. The benefits of each step will also be included.
Dynamical X-ray diffraction studies have been carried out for lattice-matched InGaAs/InP superlattices grown by modified molecular beam epitaxy (MBE) techniques. The (400) X-ray satellite pattern, which is predominantly affected by the strain modulation, was analyzed. The strain and thickness of the actual layers including the presence of strained interfacial regions were determined.
The electrical properties of pyrolyzed polymers have been studied recently.1,2 It has been shown that organic, polymeric3 and non-polymeric4 films can be made conductive (ρ ~ 10−3Ωcm) by ion beam irradiation. Common to all of the films was the presence of carbon as a constituent element and both pyrolysis and ion beam irradiation3 was shown to increase the relative carbon content of the films. The ion beam irradiated organic films 3,4 exhibited a temperature dependence of their resistivity of the form ρ(T) = ρ∞e−(TЛ)*, where ρ is the ion-induced resistivity, ρ∞ and T0 are constants and T is the temperature. At very high doses of irradiation (1017cm−2Ar+@ 2MeV) the film resistivity was temperature independent. Very similar transport properties were observed in the pyrolyzed polymers1 as well, though the lowest resistivities achieved were higher than the resistivity values observed in the ion irradiated3 polymer films. In both the pyrolysis and ion-irradiation experiments the temperature dependence has been explained by a model due to Sheng and Abeles,5 which involves charge transport by hopping between conducting islands embedded in an insulating matrix. Such striking similarities between two distinctly different modes of energy deposition in the films, prompted us to compare the effects of pyrolysis and ion irradiation in different carbon containing films. We compared both a polymer (HPR-204°) and a film of electron beam evaporated carbon film. While in the former case one would observe chemical degradation as well as structural modification, by studying pure carbon films the physical nature of the processes could be clarified. We report metallic carrier densities in both films and evidence for significant structural rearrangement. We conclude that pyrolysis and ion beam irradiation have similar effects on both polymer and carbon films.
We have explored the origin of the ion-induced conductivity in polymer films and the distinction between low energy ion-implantation and high-energy ion irradiation. In experiments involving irradiation of polymer and carbon films with ions of energy from 200 keV to 25 MeV we have established that with both low and high energy ions the polymers undergo carbonization. However, the saturation resistivity obtained with low energy implantation is four to six orders of magnitude larger than those obtained by high energy ion irradiation. In experiments on irradiation of carbon films low energy ions caused a two orders of magnitude increase in the resistivity while high energy ion caused a two orders of magnitude decrease. This implies that the structure of the carbonized polymer is different for the low and the high energy ion irradiation. While in the former case there may be no crystalline order in the films; in the latter case, a microcrystalline graphitic structure is obtained (with four orders of magnitude larger conductivity than in the former case). The formation of graphitic crystalline order with increasing high energy ion dose was verified by electron energy loss spectroscopy. This is an interesting example of crystallization induced by electronic excitation alone with no macroscopic thermal effect.
The interfacial structure of InGaAs/InP superlattices grown on (100) InP by metalorganic molecular beam epitaxy has been studied by fully dynamical simulations of high-resolution x-ray diffraction curves of the (200) and (400) reflectjon. The superlattice under investigation is lattice-matched and has a long period of ∼630Å. This kind of structure creates a very symmetrical x-ray pattern enveloping a large number of closely spaced satellite intensities with pronounced maxima and minima. It appears in the dynamical analysis that the position and shape of these maxima and minima is extremely sensitive to the number N of monolayers and atomic spacing d of the InGaAs and InP layer, as well as the presence of interfacial layers and impurities.
High-resolution X-ray diffraction (HRXRD) studies have been cardied out to determine the structural perfection and periodicity for a number of high-quality InGaAsfInP superlattices grown by gas source molecular beam epitaxy. X-ray scans were carried out with a compact four-crystal monochromator resulting in a resolution of one molecular layer (∼3,Å), which enables one to observe very small variations in the periodic structure. Sharp and strong higher-order satellite reflections in the XRD profiles were observed indicating smooth interfaces with well-defined modulated structures. Excellent computer simulated fits of the X-ray satellite pattern could be generated based on a kinematical XRD step model which assumes ideally sharp interfaces, and periodic structural parameters such as the strain in the well could be extracted. Our results3 demonstrate that HRXRD in conjunction with the kinematical step model is a very sensitive method to assess periodic structural modifications in superlattices as a result of the precise growth conditions in the gas source MBE system.
We report for the first time the growth of GaSb/AlSb multilayers and alloys on Si(100) by molecular beam epitaxy. High quality films were achieved in spite of the large lattice constant mismatch of 12%. Room temperature, optically pumped pulsed lasers emitting at 1.8μm have been demonstrated. Lateral photoconductive detectors with responsivities of 0.18 A/W have also been made. The film nucleation on the Si substrate was observed in-situ by reflection high energy electron diffraction. Characterization of the grown epilayers and preliminary optical device results are described.
We discuss the characteristics of MOMBE based selective area epitaxy useful in the preparation of optoelectronic devices. Selective area epitaxy, a process in which epitaxy is restricted only to the areas opened in a suitably prepared dielectric mask, offers a powerful method of preparing high performance devices, varying the thickness and composition of the grown layers simply by controlling the width of the open areas and monolithically integrating different device types on common substrates. Lasers, heterostructure bipolar transistors, and optoelectronic integrated circuits based on InGaAs/InP system and relying on selective area epitaxy are described.
X-ray diffraction (XRD) and Rutherford backscattering analysis (RBS) have been used independently to study the interface reaction of copperaluminum thin film couples during in-situ annealing in the temperature range 157°–220°C. For the X-ray studies a high vacuum annealing system was constructed on a Huber-Guinier thin film goniometer base1. This system enabled us to monitor the thin film interface reaction via changes of integrated X-ray intensities during the annealing treatment. RBS analysis was carried out with an existing in-situ heating stage. Using both techniques isothermal annealing experiments were carried out for four different temperatures. For this study 900Å Cu/1600Å Al and 1800Å Cu/3200Å Al thin film couples were prepared by sequential evaporation onto water cooled oxidized <111> silicon and MgO substrates.
Gold metallization for ohmic contacts is extensively used for the fabrication of InP/In1−xGaxAsyPn1−y light-emitting and microwave devices. While the electrical properties of Au/InP and Au/In1−xGaxAsyPn1−y have been the subject of many investigations, relatively little is known about the metallurgy of contact formation and solid state reactions occurring during high temperature alloying and the subsequent device processing steps. Therefore a temperature-dependent X-ray diffraction study on Au–Inn1−xGaxAsyPn1−y interface reactions was made as a function of composition x, y.
An in situ annealing X-ray study was applied to Cu-Al thin film couples over a wide range of copper-to-aluminum film ratios. This new technique, which has been previously described for a study on the Au-Al thin film system, enables us to make a temperature-dependent photographic X-ray analysis. The present study indicated that only a limited number of the wide variety of bulk phases form in the Cu-Al thin film interface, while some of these phases in the interface are transient. In the transient stages of the interface reaction, the f.c.c.-ordered phase β-Cu3A1 grows over the entire range of copper-to-aluminum film ratios after the first nucleation of CuA12, indicating a two-step nucleation reaction. On the aluminum-rich side, this phase transforms to a new ordered hexagonal phase β′. It could be interpreted as a superlattice of the metastable hexagonal ω phase occurring in zirconium-based alloys. The end phases are CuA1 and CuAl2.
The evolution of surface roughness with increasing thickness of (100) InP layersgrown by metalorganic molecular beam epitaxy has been observed by scanningforce microscopy. The process of roughening gives rise to periodic elongatedfeatures on the surface aligned in the  direction, reflecting the surfaceanisotropy. The morphology eventually evolves to a grain-like surface. Theroughening is dependent on both the group III and V flux, and the growthtemperature, indicating that this phenomenon is kinetically controlled by surfacediffusion activation. For each set of parameters chosen for the growth, there is aminimum temperature where smooth, two-dimensional growth can be obtained.Below that temperature the roughening shows two distinct power law regimesdependent on the epitaxial layer thickness.