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A recent goal of the ANL Intense Pulsed Neutron Source (IPNS) has been the fabrication of a new enriched uranium target with increased neutron flux (by a factor of 3) which is dimensionally stable under irradiation. Neutron diffraction, using several instruments both at IPNS and MURR, has been used as a probe to characterize the target material vith respect to grain size and preferred orientation. The samples studied were portions of the uranium discs (4" diameter X 1/2" thick) which, when stacked, form the target assembly at IPNS. The old target discs were fabricated as slices from a fast cooled casting (arc-melted, water cooled in a cylindrical mold) and possess small grain size and negligible orientation. The new enriched target discs, on the other hand, are being fabricated from a slow cooled material (graphite book-mold, natural cooling) and, prior to additional treatment, have a large grain size and a high degree of preferred orientation which could produce dimensional changes during fission as the target is used. Our conclusion from this investigation is that a β-phase heat treatment (quench from 730°C) is necessary to produce a finer grain and more nearly random texture in thg new enriched material. Based on our detailed texture measurements the anticipated target lifetime of several years appears feasible.
We have been using the technique of pulsed neutron powder diffraction to study several problems in the physics and chemistry of the actinide elements. In these elements one often encounters very complex structures resulting from polymorphic transformations presumably induced by the presence of 5f-electrons. For exampie, at least five distinct structures of plutonium metal are found between room temperature and its melting point of 640°C, and two of the structures are monoclinic! Single crystals are usually not available, and the high resolution which is intrinsic to the time-of-flight powder technique is a powerful tool in the solution of complex structural problems. The relatively low absorption coefficients for neutrons for at least some actinide isotopes is an advantage when surface oxidation is a problem (as in high-temperature experiments) and provides good particle statistics so that high-quality data are available for Rietveld refinement. The low absorption of neutrons by other materials such as vanadium and fused silica enables the use of these materials for the containment of samples in high- and low-temperature environments, and the fixed geometry of the time-of-flight technique simplifies the design of furnaces and cryostats.
Pulsed neutron powder diffraction studies at IPNS have expanded our understanding of the phases present in Integral Fast Reactor (IFR) metal fuel alloys at temperatures in the range of reactor operating conditions. We report results from the binary alloy (U-10wt.%Zr) and ternary alloys (U-8%Pu-10%Zr) and (U-19%Pu-10%Zr). Determining the role and the location of Zr and Pu in these alloys is considered of fundamental importance for maximizing engineering efficiency.
Rietveld profile analysis was utilized to study the phase diagrams. Data were collected at temperatures ranging from 25-650°C. Although the expected U/Pu/Zr phases (α-U, β-U, γ-U, δ-U/Zr/Pu, ζ-U/Pu) were observed in appropriate temperature ranges, there were some unexpected results. Relative amounts of all phases at each temperature were calculated from Rietveld scale factors and inferences were made as to the location of zirconium and plutonium, i.e. amounts in each phase, from site occupancies and absorption characteristics of the phases present. Finally, we were able to identify ZrO and ZrO1-x inclusion phases in the U-Zr alloy present in very small (0.5-1.0%) amounts.
We have determined the strain and particle size for several samples of palladium powder by time-of-flight nrutron powder diffraction on two different diffractometers and by x-ray powder diffraction. The results are compared and found to be in fair agreement. The time-of-flight method gives good enough precision to reveal deficiencies in the simple models used for strain and particle size line broadening.
Background: EMBRACE (NCT02462759) Part 1 is a randomized, double-blind, sham-procedure controlled study assessing safety/tolerability of intrathecal nusinersen (12-mg equivalent dose) in symptomatic infants/children with SMA who were not eligible to participate in ENDEAR or CHERISH. Methods: Eligible participants had onset of SMA symptoms at ≤6 months with 3 SMN2 copies; onset at ≤6 months, age >7 months and 2 copies; or onset at >6 months, age ≤18 months, and 2/3 copies. Safety/tolerability was the primary endpoint. Exploratory endpoints included Hammersmith Infant Neurological Examination Section 2 (HINE-2) motor milestone attainment, change in ventilator use, and growth. Results: EMBRACE Part 1 was terminated early based on positive results from ENDEAR. Safety/tolerability was similar to previous trials. More nusinersen-treated (11/14;79%) vs. sham–treated individuals (2/7;29%) were HINE-2 motor milestone responders. Between Day 183 and 302, mean (SD) hours of ventilator use changed by +1.236 (3.712) hours in nusinersen-treated (n=12) and +2.123 (3.023) hours in sham–treated individuals (n=7). Similar increases in weight and body length were observed in nusinersen-treated and sham–treated individuals by Day 183. Conclusions: In EMBRACE Part 1, nusinersen demonstrated a favorable benefit-risk profile. These results add to the aggregated efficacy, safety/tolerability data of nusinersen in SMA.
X-ray computed tomography (CT) measurements of live sheep have been used to predict carcass composition very accurately (Macfarlane et al., 2006). The utilisation of spiral CT scans (SCTS) for quantifying muscle volumes and weights, using automatic image analysis procedures has also been shown to be very accurate in sheep (Navajas et al., 2006). Although the limiting size of the CT gantry prevents CT scanning of live beef cattle, beef primal joints are small enough to be scanned. Hence, SCTS could be used to quantify beef carcass composition, and provide valuable information for breeding programmes including composition faster than by anatomical dissection. The objective of this study was to develop a CT image analysis procedure to assess fat, muscle and bone weights of beef carcasses and to evaluate its accuracy.
Research has shown both production and health benefits for the use of chicory (Cichorium intybus) within ruminant diets. Despite this, little was known about the effects of this forage, containing differing fatty acid profiles and secondary plant compounds compared with ryegrass, on beef stability, fatty acid composition or sensory properties. An experiment was conducted to investigate whether the inclusion of chicory in the diet of grazing beef steers would alter these three properties in the M. Longissimus muscle when compared with beef steers grazing perennial ryegrass (Lolium perenne). Triplicate 2 ha plots were established with a chicory (cv. Puna II)/perennial ryegrass mix or a perennial ryegrass control. A core group of 36 Belgian Blue – cross steers were used within a 2-year beef finishing experiment (n=6/replicate plot). In the 2nd grazing year, steers were slaughtered as they reached a target fat class of 3. Muscle pH was checked 2 and 48 h post-slaughter. A section of the hindloin joint containing the M. Longissimus lumborum muscle was removed and a 20 mm-thick steak was cut and muscle samples were taken for analysis of vitamin E and fatty acid analysis. The remaining section of the loin was vacuum packed in modified atmosphere packs and subjected to simulated retail display. A section of the conditioned loin was used for sensory analysis. Data on pH, vitamin E concentration and colour stability in a simulated retail display showed there were no effects of including chicory in the diet of grazing beef steers on meat stability. There were also no differences found in the fatty acid composition or the overall eating quality of the steaks from the two treatments. In conclusion, there were no substantive effects of including chicory in the swards of grazing beef cattle on meat stability, fatty acid composition or sensory properties of the M. Longissimus muscle when compared with beef steers grazing ryegrass-only swards.
The main question that Firestone & Scholl (F&S) pose is whether “what and how we see is functionally independent from what and how we think, know, desire, act, and so forth” (sect. 2, para. 1). We synthesize a collection of concerns from an interdisciplinary set of coauthors regarding F&S's assumptions and appeals to intuition, resulting in their treatment of visual perception as context-free.
Pleated membrane filters are widely used in many applications, and offer significantly better surface area to volume ratios than equal-area unpleated membrane filters. However, their filtration characteristics are markedly inferior to those of equivalent unpleated membrane filters in dead-end filtration. While several hypotheses have been advanced for this, one possibility is that the flow field induced by the pleating leads to spatially non-uniform fouling of the filter, which in turn degrades performance. In this paper we investigate this hypothesis by developing a simplified model for the flow and fouling within a pleated membrane filter. Our model accounts for the pleated membrane geometry (which affects the flow), for porous support layers surrounding the membrane, and for two membrane fouling mechanisms: (i) adsorption of very small particles within membrane pores; and (ii) blocking of entire pores by large particles. We use asymptotic techniques based on the small pleat aspect ratio to solve the model, and we compare solutions to those for the closest-equivalent unpleated filter.
Government support uncertainty, scarce yield information, and the inherent risk in bioeconomic phenomena are some of the deterrents faced by investors in the nascent cellulosic biofuel industry. A financial probabilistic model was developed to contrast the economic feasibility of producing cellulosic biofuels from energy cane and sweet sorghum using three technologies: hydrolysis, pyrolysis, and gasification. Hydrolysis and pyrolysis proved feasible (showed possibilities of a positive net present value) without government support and conditioned to stochastic feedstock yields and biofuel prices. Gasification was feasible with government support. Improved feedstock and biofuel productivity would considerably raise the feasibility probabilities for hydrolysis and pyrolysis without government support.
The synthetic auxin herbicides, aminocyclopyrachlor and clopyralid, control dicotyledonous weeds in turf. Clippings of turfgrass treated with synthetic auxin herbicides have injured off-target plants exposed to herbicide-laden clippings. Labels of aminocyclopyrachlor and clopyralid recommend that clippings of treated turfgrass remain on the turf following a mowing event. Alternative uses for synthetic auxin-treated turfgrass clippings are needed because large quantities of clippings on the turf surface interfere with the functionality and aesthetics of golf courses, athletic fields, and residential turf. A white clover bioassay was conducted to determine the persistence and bioavailability of aminocyclopyrachlor and clopyralid in turfgrass clippings. Aminocyclopyrachlor and clopyralid were each applied at 79 g ae ha−1 to mature tall fescue at 56, 28, 14, 7, 3.5, and 1.75 d before clipping collection (DBCC). Clippings were collected, and the treated clippings were recycled onto adjacent white clover plots to determine herbicidal persistence and potential for additional weed control. Clippings of tall fescue treated with aminocyclopyrachlor produced a nonlinear regression pattern of response on white clover. Calculated values for 50% response (GR50) for visual control, for normalized difference vegetative index (NDVI), and for reduction in harvested biomass were 20.5, 17.3, and 18.7 DBCC, respectively, 8 wk after clippings were applied. Clippings of tall fescue treated with clopyralid did not demonstrate a significant pattern for white clover control, presumably because clopyralid was applied at a less-than-label rate. The persistence and bioavailability of synthetic auxin herbicides in clippings harvested from previously treated turfgrass creates the opportunity to recycle clippings for additional weed control.
We present the results of an all sky survey for binary systems among the massive stars that we made with the HST Fine Guidance Sensors. The sample of 225 stars is comprised mainly of Galactic O- and B-type stars and Luminous Blue Variables, plus a few luminous stars in the LMC. The FGS TRANS mode observations are sensitive to detection of companions with an angular separation of 0.01–1 arcsec and brighter than △m = 5 mag. The FGS observations resolved 52 binary and 6 triple star systems and detected partially resolved binaries in 7 additional targets, yielding a companion detection frequency of 29%. We also gathered literature results on the numbers of close spectroscopic binaries and wider astrometric binaries among the sample. These results confirm the high multiplicity fraction. The period distribution is essentially flat in increments of log P, although there remains an observational gap in detections for periods of years and decades.
Patients experience reductions in quality of life (QOL) while receiving cancer treatment and several approaches have been proposed to address QOL issues. In this project, the QOL differences between older adult (age 65+) and younger adult (age 18–64) advanced cancer patients in response to a multidisciplinary intervention designed to improve QOL were examined.
This study was registered on ClinicalTrials.gov, NCT01360814. Newly diagnosed advanced cancer patients undergoing radiation therapy were randomized to active QOL intervention or control groups. Those in the intervention group received six multidisciplinary 90-minute sessions designed to address the five major domains of QOL. Outcomes measured at baseline and weeks 4, 27, and 52 included QOL (Linear Analogue Self-Assessment (LASA), Functional Assessment of Cancer Therapy–General (FACT-G)) and mood (Profile of Mood States (POMS)). Kruskall–Wallis methodology was used to compare scores between older and younger adult patients randomized to the intervention.
Of 131 patients in the larger randomized controlled study, we report data on 54 evaluable patients (16 older adults and 38 younger adults) randomized to the intervention. Older adult patients reported better overall QOL (LASA 74.4 vs. 62.9, p = 0.040), higher social well-being (FACT-G 91.1 vs. 83.3, p = 0.045), and fewer problems with anger (POMS anger–hostility 95.0 vs. 86.4, p = 0.028). Long-term benefits for older patients were seen in the anger–hostility scale at week 27 (92.2 vs. 84.2, p = 0.027) and week 52 (96.3 vs. 85.9, p = 0.005).
Older adult patients who received a multidisciplinary intervention to improve QOL while undergoing advanced cancer treatments benefited differently in some QOL domains, compared to younger adult patients. Future studies can provide further insight on how to tailor QOL interventions for these age groups.
Synthetic auxin herbicides are commonly used in forage, pasture, range, and turfgrass settings for dicotyledonous weed control. Aminocyclopyrachlor (AMCP) is a newly developed pyrimidine carboxylic acid with a chemical structure and mode of action similar to the pyridine carboxylic acids—aminopyralid, clopyralid, and picloram. Injury to sensitive dicotyledonous plants has been observed following exposure to monocotyledonous plant material previously treated with pyridine compounds. The absorption, translocation, and metabolism of AMCP has been documented in susceptible broadleaf weeds; however, no information is available, to our knowledge, regarding AMCP fate in tolerant Poaceae, which may serve as the vector for off-target plant injury. Based on this premise, research was conducted to characterize absorption, translocation, and metabolism of AMCP in tall fescue. 14C-AMCP was applied to single tiller tall fescue plant foliage under controlled laboratory conditions at North Carolina State University (Raleigh, NC). Radiation was quantified in leaf wash, treated leaf, foliage, crown, roots, and root exudates at 3, 12, 24, 48, 96, and 192 h after treatment (HAT). 14C-AMCP was rapidly absorbed by tall fescue, reaching 38 and 68% at 3 and 48 HAT, respectively. Translocation of 14C-AMCP was limited to the foliage, which reached maximum translocation (34%) at 96 HAT. Most of the recovered 14C-AMCP remained in the leaf wash, treated leaf, or foliage, whereas minimal radiation was detected in the crown, roots, or root exudates throughout the 192-h period. No AMCP metabolism was observed in tall fescue through the 192 HAT. These data suggest AMCP applied to tall fescue can remain bioavailable, and mishandling treated plant material could result in off-target injury.