Lowering Respirable Dust Exposures at Mineral Processing Facilities

This article discusses three research projects performed by the National Institute for Occupational Safety and Health, (formerly the Bureau of Mines), that reduce the respirable dust exposure of plant workers at mineral processing facilities. All three of these projects are very different but they all have the same goal of reducing worker exposure to respirable dust at mineral processing facilities. The first project deals with a total mill ventilation system that reduces dust levels throughout an entire building and lowers the dust exposure of everyone working in the structure. The second project describes a bag and belt cleaner device that reduces the amount of dust on the outside of bags of product and primarily reduces the dust exposure of the bag stackers, as well as anyone handling the bags until their end use. The third project discusses how to reduce a worker\u27s dust exposure from secondary dust sources through improved work practices. This area of research can potentially impact all workers at these facilities. All three of these research projects have been shown to significantly reduce the dust exposure of workers at mineral processing facilities

Application of fast technology for analysis (FTA) for sampling and recovery of deoxyribonucleic acid (DNA) for molecular characterization of cowpea breeding lines for Striga resistance

Article purchasedStriga gesnerioides (Willd) Vatke is a significant constraint to cowpea production in the dry savannas of sub-Saharan Africa. Yield losses caused by S. gesnerioides in these regions are estimated in millions of tons annually and the prevalence of Striga soil infestation is steadily increasing. Conventional breeding efforts have developed some cowpea lines with Striga resistance as well as other important agronomic traits but it is time-consuming and difficult to pyramid favorable traits. The use of marker-assisted selection (MAS) makes it easier to select plant traits and reduce the time needed to develop new varieties. The potential of Fast Technology for Analysis (FTA) as an effective technology for sampling and retrieval of DNA from plant tissue and their subsequent molecular analysis was assessed in the laboratory. DNA was successfully recovered from the leaf tissues of cowpea pressed into the FTA® Classic card and the DNA obtained from the FTA papers was found to be suitable for molecular analysis by PCR-based techniques. The marker efficiency of Sequence Characterized Amplified Region (SCAR) marker MahSe2 and C42B was 93% in detecting SG3 resistance. This study demonstrated that the application of MAS using FTA technology has the potential to put the breeding process on a fast track and increase the efficiency of breeding activities

Progress with the Upgrade of the SPS for the HL-LHC Era

The demanding beam performance requirements of the High Luminosity (HL-) LHC project translate into a set of requirements and upgrade paths for the LHC injector complex. In this paper the performance requirements for the SPS and the known limitations are reviewed in the light of the 2012 operational experience. The various SPS upgrades in progress and still under consideration are described, in addition to the machine studies and simulations performed in 2012. The expected machine performance reach is estimated on the basis of the present knowledge, and the remaining decisions that still need to be made concerning upgrade options are detailed.Comment: 3 p. Presented at 4th International Particle Accelerator Conference (IPAC 2013

Near-infrared-actuated devices for remotely controlled drug delivery

A reservoir that could be remotely triggered to release a drug would enable the patient or physician to achieve on-demand, reproducible, repeated, and tunable dosing. Such a device would allow precise adjustment of dosage to desired effect, with a consequent minimization of toxicity, and could obviate repeated drug administrations or device implantations, enhancing patient compliance. It should exhibit low off-state leakage to minimize basal effects, and tunable on-state release profiles that could be adjusted from pulsatile to sustained in real time. Despite the clear clinical need for a device that meets these criteria, none has been reported to date to our knowledge. To address this deficiency, we developed an implantable reservoir capped by a nanocomposite membrane whose permeability was modulated by irradiation with a near-infrared laser. Irradiated devices could exhibit sustained on-state drug release for at least 3 h, and could reproducibly deliver short pulses over at least 10 cycles, with an on/off ratio of 30. Devices containing aspart, a fast-acting insulin analog, could achieve glycemic control after s.c. implantation in diabetic rats, with reproducible dosing controlled by the intensity and timing of irradiation over a 2-wk period. These devices can be loaded with a wide range of drug types, and therefore represent a platform technology that might be used to address a wide variety of clinical indications

Reductions in aircraft particulate emissions due to the use of Fischer–Tropsch fuels

The use of alternative fuels for aviation is likely to increase due to concerns over fuel security, price stability, and the sustainability of fuel sources. Concurrent reductions in particulate emissions from these alternative fuels are expected because of changes in fuel composition including reduced sulfur and aromatic content. The NASA Alternative Aviation Fuel Experiment (AAFEX) was conducted in January–February 2009 to investigate the effects of synthetic fuels on gas-phase and particulate emissions. Standard petroleum JP-8 fuel, pure synthetic fuels produced from natural gas and coal feedstocks using the Fischer–Tropsch (FT) process, and 50% blends of both fuels were tested in the CFM-56 engines on a DC-8 aircraft. To examine plume chemistry and particle evolution with time, samples were drawn from inlet probes positioned 1, 30, and 145 m downstream of the aircraft engines. No significant alteration to engine performance was measured when burning the alternative fuels. However, leaks in the aircraft fuel system were detected when operated with the pure FT fuels as a result of the absence of aromatic compounds in the fuel. <br><br> Dramatic reductions in soot emissions were measured for both the pure FT fuels (reductions in mass of 86% averaged over all powers) and blended fuels (66%) relative to the JP-8 baseline with the largest reductions at idle conditions. At 7% power, this corresponds to a reduction from 7.6 mg kg⁻¹ for JP-8 to 1.2 mg kg⁻¹ for the natural gas FT fuel. At full power, soot emissions were reduced from 103 to 24 mg kg⁻¹ (JP-8 and natural gas FT, respectively). The alternative fuels also produced smaller soot (e.g., at 85% power, volume mean diameters were reduced from 78 nm for JP-8 to 51 nm for the natural gas FT fuel), which may reduce their ability to act as cloud condensation nuclei (CCN). The reductions in particulate emissions are expected for all alternative fuels with similar reductions in fuel sulfur and aromatic content regardless of the feedstock. <br><br> As the plume cools downwind of the engine, nucleation-mode aerosols form. For the pure FT fuels, reductions (94% averaged over all powers) in downwind particle number emissions were similar to those measured at the exhaust plane (84%). However, the blended fuels had less of a reduction (reductions of 30–44%) than initially measured (64%). The likely explanation is that the reduced soot emissions in the blended fuel exhaust plume results in promotion of new particle formation microphysics, rather than coating on pre-existing soot particles, which is dominant in the JP-8 exhaust plume. Downwind particle volume emissions were reduced for both the pure (79 and 86% reductions) and blended FT fuels (36 and 46%) due to the large reductions in soot emissions. In addition, the alternative fuels had reduced particulate sulfate production (near zero for FT fuels) due to decreased fuel sulfur content. <br><br> To study the formation of volatile aerosols (defined as any aerosol formed as the plume ages) in more detail, tests were performed at varying ambient temperatures (−4 to 20 °C). At idle, particle number and volume emissions were reduced linearly with increasing ambient temperature, with best fit slopes corresponding to −8 × 10¹⁴ particles (kg fuel)⁻¹ °C⁻¹ for particle number emissions and −10 mm³ (kg fuel)⁻¹ °C⁻¹ for particle volume emissions. The temperature dependency of aerosol formation can have large effects on local air quality surrounding airports in cold regions. Aircraft-produced aerosols in these regions will be much larger than levels expected based solely on measurements made directly at the engine exit plane. The majority (90% at idle) of the volatile aerosol mass formed as nucleation-mode aerosols, with a smaller fraction as a soot coating. Conversion efficiencies of up to 2.8% were measured for the partitioning of gas-phase precursors (unburned hydrocarbons and SO₂) to form volatile aerosols. Highest conversion efficiencies were measured at 45% power

Skill tests of three-dimensional tidal currents in a global ocean model: A look at the North Atlantic

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92458/1/jgr_timkoetal_northatlatnictidalcurrentskilltest_2012.pd

Efficiency of molecular markers to select for Striga gesnerioides resistance in cowpca [Vigna unguiculata (L.)Walp]

Striga gesnerioides (Willd) Vatke is a major biological constraint to cowpea productivity in the dl) savannas of sub-Saharan Africa. Over the last two decades, the use of molecular markers in crop improvemem has gained prominence owing to its ability to sh0l1en the breeding cycle. The available molecular markel techniques are being improved upon and continuously tested for higher preci sion, shOl1er duration of application and better cost effectiveness. [n the present study, a total of four molecular markers developed for selecting Slriga resistant cowpea were used to genotype F2 population derived from a cross between Borno Brown and [T97K-499-35 to identify markers more close ly linked to S. gesnerioides resistance. SSRI and 2 were found 10 be tight ly linked to Striga gesnerioides with a genetic distance of 1 and 2cM.The selection efficiency of SS~I and SSR-2 were 99 and 98 % and was better than that of C42-B 85.5%

Are Iraq and Afghanistan Veterans Using Mental Health Services? New Data From a National Random-Sample Survey

This study analyzed data from a national survey of Iraq and Afghanistan veterans to improve understanding of mental health services use and perceived barriers

Limits on neutrino oscillations from ν̄e appearance

A 20-ton neutrino detector located near the Los Alamos Meson Physics Facility beam stop is used search for ν̄e generated via neutrino oscillations from any of the three neutrino types, νμ, ν̄μ, and νe, which radiate from the beam stop. The analysis of three years of data provides limits on the oscillation modes ν̄μ→ν̄e, νe→ν̄e, and νμ→ν̄e, and the lepton-number-violating decay process μ+→e++ν̄e+νμ. The 90%-confidence-level limits for ν̄μ→ν̄e oscillations are δm2≤0.14 eV2 for maximal mixing, and sin22θ≤0.024 for large δm2. © 1993 The American Physical Society