Performance criteria guideline for three explosion protection methods of electrical equipment rated up to 15,000 volts AC

The Bureau of Mines, U.S. Department of the Interior, is reviewing explosion protection methods for use in gassy coal mines. This performance criteria guideline is an evaluation of three explosion protection methods of machines electrically powered with voltages up to 15,000 volts ac. A sufficient amount of basic research has been accomplished to verify that the explosion proof and pressurized enclosure methods can provide adequate explosion protection with the present state of the art up to 15,000 volts ac. This routine application of the potted enclosure as a stand alone protection method requires further investigation or development in order to clarify performance criteria and verification certification requirements. An extensive literature search, a series of high voltage tests, and a design evaluation of the three explosion protection methods indicate that the explosion proof, pressurized, and potted enclosures can all be used to enclose up to 15,000 volts ac

Infant and Toddler Programs: Recommendations for a Stimulating Learning Environment

Recommendations for practices that strengthen early childhood programs are proposed based on findings from two studies. The Infant-Toddler Environment Rating Scale-Revised is widely used to assess infant a toddler classrooms. A total of 102 infant and toddler classrooms in Missouri were observed for these studies and provide the basis for information in this recommended practices document. Items from the Environment Rating Scale that were consistently rated as below average were divided into three program components: room/furniture design, displayed materials, and play materials. Specific recommendations for improving programs are outlined

Infant and Toddler Programs: Recommendations for Quality Child-Teacher Interactions

Recommendations for practices that strengthen early childhood programs are proposed based on findings from two studies. In one study, researchers in the Midwest Child Care Research Consortium conducted a study to assess program quality. In the second study, observations were conducted using the Environment Rating Scales as part of the Missouri Quality Rating System Pilot Study. The Infant-Toddler Environment Rating Scale-Revised is widely used to assess infant and toddler classrooms. Items from the Environment Rating Scale that were consistently rated as below average are divided into four program components: displayed materials, block play, pretend play, and free play. Specific recommendations for improving programs are outlined

Home-Based Programs: Recommendations to Improve Program Quality

Recommendations for practices that strengthen early childhood programs are proposed based on findings from two studies. The Family Day Care Rating Scale is widely used to assess program quality. A total of 223 home-based programs in Missouri were observed for these studies and provide the basis for information in this recommended practices document. Items from the Environment Rating Scale that were consistently rated as below average were divided into two program components: health and safety issues and programming. Specific recommendations for improving programs are outlined

The unique chemistry of Eastern Mediterranean water masses selects for distinct microbial communities by depth

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Preschool Classrooms: Recommendations to Improve the Quality of Early Childhood Programs

Recommendations for practices that strengthen early childhood programs are proposed based on findings from two studies. The Early Childhood Environment Rating Scale-Revised is widely used to assess preschool classrooms. A total of 191 preschool classrooms in Missouri were observed for these studies and provide the basis for information in this recommended practices document. Items from the Environment Rating Scale that were consistently rated as below average were divided into two program components: health and safety issues and programming/curriculum. Specific recommendations for improving programs are outlined. are outlined

Evaluating efficacy of a ballast water filtration system for reducing spread of aquatic species in freshwater ecosystems

Biological invasions by non-indigenous species are considered a leading threat to biodiversity, with prevention being a key management strategy. Consequently, numerous commercial ballast water treatment systems have been, or are being, developed to prevent future aquatic invasions. However, most treatment systems are being designed for the many vessels undertaking long transoceanic voyages in marine waters rather than the relatively few vessels operating on short voyages in freshwater, such as those in the Laurentian Great Lakes. Here we conduct testing of the biological efficacy of a 40 µm ballast water filtration unit through shipboard trials. We test the hypotheses that i) filtration will significantly reduce abundance of zooplankton greater than 50 µm in size but not phytoplankton 10 to 50 µm in size; ii) filtration will reduce zooplankton abundances in ballast water below International Maritime Organization discharge standards, but not those of phytoplankton; and iii) filtration will alter the community composition of zooplankton, non-randomly reducing invasion risk of larger taxa. During the summer of 2012, three shipboard trials were conducted. Ballast water samples were collected using a before-after experimental design. Our study showed that filtration significantly reduced abundance of copepods and cladocerans, but not of juvenile dreissenid veligers and rotifers. Contrary to our expectation, phytoplankton densities were also significantly lower after the treatment. Overall, ballast water treated during our tests would not meet proposed international discharge standards. Filtration altered relative abundance of zooplankton, but did not reduce introduction risk of any taxonomic group due to the small juvenile stages and dormant eggs which passed through the treatment. While we do not rule out filtration as a ballast water treatment option for zooplankton in the future, our tests indicate further development is required for meaningful reduction of invasion risk

Measurement of the spatial dependence of temperature and gas and soot concentrations within large open hydrocarbon fuel fires

A series of large-scale JP-4 fuel pool fire tests was conducted to refine existing mathematical models of large fires. Seven tests were conducted to make chemical concentration and temperature measurements in 7.5 and 15 meter-diameter pool fires. Measurements were made at heights of 0.7, 1.4, 2.9, 5.7, 11.4, and 21.3 meters above the fires. Temperatures were measured at up to 50 locations each second during the fires. Chemistry samples were taken at up to 23 locations within the fires and analyzed for combustion chemistry and soot concentration. Temperature and combustion chemistry profiles obtained during two 7.5 meter-diameter and two 15 meter-diameter fires are included

Ancient Chinese methods are remarkably effective for the preparation of artemisinin-rich extracts of Qing Hao with potent antimalarial activity.

yesAncient Chinese herbal texts as far back as the 4th Century Zhou hou bei ji fang describe methods for the use of Qing Hao (Artemisia annua) for the treatment of intermittent fevers. Today, the A. annua constituent artemisinin is an important antimalarial drug and the herb itself is being grown and used locally for malaria treatment although this practice is controversial. Here we show that the ancient Chinese methods that involved either soaking, (followed by wringing) or pounding, (followed by squeezing) the fresh herb are more effective in producing artemisinin-rich extracts than the usual current method of preparing herbal teas from the dried herb. The concentrations of artemisinin in the extracts was up to 20-fold higher than that in a herbal tea prepared from the dried herb, but the amount of total artemisinin extracted by the Chinese methods was much less than that removed in the herbal tea. While both extracts exhibited potent in vitro activities against Plasmodium falciparum, only the pounded juice contained sufficient artemisinin to suppress parasitaemia in P. berghei infected mice. The implications of these results are discussed in the context of malaria treatment using A. annua infusions

A multi-scale investigation into seafloor topography of the northern Mid-Atlantic Ridge based on geographic information system analysis

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