scholarly journals Laboratory results of foam application testing for longwall shield dust control in a simulated environment

2021 ◽  
Author(s):  
W. R. Reed ◽  
M. R. Shahan ◽  
Y. Zheng ◽  
A. Mazzella
Keyword(s):  
The United States ◽  
Dust Control ◽  
Respirable Dust ◽  
Coal Face ◽  
Low Velocity ◽  
Dust Generation ◽  
Simulated Environment ◽  
Laboratory Results ◽  
Time Periods ◽  
Dust Reduction

AbstractThere were 37 longwall faces operating in mines in the United States in 2019. The average panel width for these longwalls was approximately 368.5 m (1209 ft). This translates to a range of approximately 170–240 shields per longwall, depending upon the width of shield. The movement of longwall shields is a significant contributor to respirable dust overexposures to longwall operators. Foam is expected to have the potential to reduce this shield dust generation. The foam is applied to the area on the roof between the coal face and the shield tip after the shearer passes. In this study, the longwall shield dust simulator was used to test three foam agents for their ability to control dust from longwall shield movements. Results showed that at low-velocity ventilation (≈ 3.0 m/s (600 fpm)) all foam agents were able to produce dust reduction levels of at least 45%. At high-velocity ventilation (≈ 5.1 m/s (1000 fpm)), the reductions were lower and more variable, ranging from being undeterminable for one foam agent to having 46%–63% reductions for the other two foam agents, with one instance of an increase in dust concentration. Overall, the use of foam agents can provide longwall shield dust control. Important factors are roof coverage and the ability of foam to remain on the roof for extended time periods.

scholarly journals The Laboratory Diagnosis of HIV Infections

2005 ◽  
Vol 16 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Margaret Fearon
Keyword(s):  
Point Of Care ◽  
Diagnostic Testing ◽  
Clinical Information ◽  
Hiv Infections ◽  
Laboratory Diagnosis ◽  
The United States ◽  
Specific Information ◽  
Antibody Testing ◽  
Diagnostic Laboratory ◽  
Laboratory Results

HIV diagnostic testing has come a long way since its inception in the early 1980s. Current enzyme immunoassays are sensitive enough to detect antibody as early as one to two weeks after infection. A variety of other assays are essential to confirm positive antibody screens (Western blot, polymerase chain reaction [PCR]), provide an adjunct to antibody testing (p24 antigen, PCR), or provide additional information for the clinician treating HIV-positive patients (qualitative and quantitative PCR, and genotyping). Most diagnostic laboratories have complex testing algorithms to ensure accuracy of results and optimal use of laboratory resources. The choice of assays is guided by the initial screening results and the clinical information provided by the physician; both are integral to the laboratory's ability to provide an accurate laboratory diagnosis. Laboratories should also provide specific information on specimen collection, storage and transport so that specimen integrity is not compromised, thereby preserving the accuracy of laboratory results. Point of Care tests have become increasingly popular in the United States and some places in Canada over the past several years. These tests provide rapid, on-site HIV results in a format that is relatively easy for clinic staff to perform. However, the performance of these tests requires adherence to good laboratory quality control practices, as well as the backup of a licensed diagnostic laboratory to provide confirmation and resolution of positive or indeterminate results. Laboratory quality assurance programs and the participation in HIV proficiency testing programs are essential to ensure that diagnostic laboratories provide accurate, timely and clinically relevant laboratory results.

Who Wins and Who Loses in the Provincial Courts of Appeal? A Statistical Analysis, 1920–1990

1994 ◽  
Vol 9 (2) ◽  
pp. 21-40 ◽  
Author(s):  
Peter McCormick
Keyword(s):  
United States ◽  
Statistical Analysis ◽  
Great Britain ◽  
Data Base ◽  
The United States ◽  
Different Types ◽  
Party Capability ◽  
Time Periods ◽  
Appeal Courts ◽  
Different Levels

AbstractGiven the visibility and obvious importance of judicial power in the age of the Charter, it is important to develop the conceptual vocabulary for desribing and assessing this power. One such concept that has been applied to the study of appeal courts in the United States and Great Britain is “party capability”, a theory which suggests that different types of litigant will enjoy different levels of success as both appellant and respondent. Using a data base derived from the reported decisions of the provincial courts of appeal for the second and seventh year of each decade since the 1920s, this article applies party capability theory to the performance of the highest courts of the ten provinces; comparisons are attempted across regions and across time periods, as well as with the findings of similar studies of American and British courts.

scholarly journals Dust Concentration Changing Regularities and Dust Reduction Technology by Spray Negative Pressure in Fully Mechanized Mining Face

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Lirong Wu ◽  
Hongxuan Chen ◽  
Jiamin Li ◽  
Shican Fu ◽  
Yuyan Zhuang
Keyword(s):  
Negative Pressure ◽  
Flow Characteristics ◽  
Dust Concentration ◽  
Inlet Section ◽  
Coal Face ◽  
Dust Suppression ◽  
Mining Face ◽  
Dust Distribution ◽  
Dust Reduction ◽  
Ventilation Velocity

The dust concentration changing regularities are the basis to take dust depression measures, which is greatly influenced by the airflow. In the software of FLUENT, the value of ventilation velocity is set as a constant, which cannot express the real ventilation. According to the flow characteristics of the sublayer and data from Nicholas’ experiment, the ventilation velocity distribution formula of sublayer in the inlet section of fully mechanized caving coal face is deduced. The boundary condition of velocity is given by UDF. Taking the 3top1110 fully mechanized caving coal face as an example, the dust distribution in the process of coal mining and hydraulic support shifting was studied. According to the dust-spray coupling experiment, three types of nozzle are chosen based on the efficiency of dust suppression. Combining the dust migration rule and the characteristics of nozzles, the negative pressure-secondary dust suppression devices of spray were developed and applied. And the above measures have lowered the dust concentration effectively.

Abstract P266: The Association Of Recent Age-specific Growth Of The > 65 Years Population With Heart Disease Mortality In The United States, 2005-2017

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Stephen Sidney ◽  
Sadiya S Khan ◽  
Yariv Gerber ◽  
Donald M Lloyd-jones ◽  
Alan S Go ◽  
...  
Keyword(s):  
Heart Disease ◽  
Mortality Rate ◽  
Population Growth ◽  
Total Population ◽  
Age Groups ◽  
The United States ◽  
Population Increase ◽  
Age Group ◽  
Specific Population ◽  
Time Periods

Introduction: In 2011, the number of deaths with an underlying cause of heart disease (HD) reached its lowest level in 56 years. However, there has subsequently been a steady increase in the annual number of total HD deaths, owing to a rapid increase (23%) in the size of the population ≥65 years of age in the U.S. To understand these trends, we sought to characterize differences between 2005-2011 and 2011-2017 in population and mortality by age subgroups among those ≥65 years. Methods: We determined age-specific population size, HD mortality rate, and absolute number of HD deaths in the ≥65 age group for the time periods 2005-2011 and 2011-2017, as well as for the <65 years age group, using the CDC WONDER online data set. Results: Age-specific population growth was greatest among those 65-74 years between 2005-2011 and 2011-2017, representing 76% of the total population growth among those ≥65 years old in both time periods (Table) and 51% of the growth for the entire population from 2011-2017. From 2005-2011, decreases in the mortality rate of 20% or greater in each of the age subgroups (65-74, 75-84, 85+) resulted in a decline in the number of total HD deaths in each of the age groups in spite of substantial population increases in the 65-74 and 85+ age groups. However, subsequent changes in the age-specific mortality rate among those ≥65 years were lower than population increases from 2011-2017, resulting in an increased number of total HD deaths in all > 65 years age subgroups. This was most notable among those age 65-74 years in whom the 32% population increase with a 1.5% decline in the mortality rate resulted in a 30% increase in the number of HD deaths, representing 61.3% of the increase in number of HD deaths in the 65+ years age group and 53% of the increase of HD deaths in all age groups from 2011-2017. Conclusions: The rapid growth of the 65-74 years age group (baby boomers) accounts for most of the population growth in the ≥65 years age group and more than half the increase in both total population growth and the total number of HD deaths from 2011-2017.

Relationships between Respirable Dust Generation and Coal Seam Characteristics

1996 ◽  
Vol 11 (7) ◽  
pp. 655-661 ◽  
Author(s):  
P. Jha ◽  
H. S. Chiang ◽  
S. Q. Yuan ◽  
R. L. Grayson ◽  
A. W. Khair ◽  
...  
Keyword(s):  
Coal Seam ◽  
Respirable Dust ◽  
Dust Generation

A Comparison of Funding Patterns in Professional Occupational Therapy Education Programs

1994 ◽  
Vol 14 (3) ◽  
pp. 157-169 ◽  
Author(s):  
Winnie Dunn ◽  
Mary Ann Boyle
Keyword(s):  
United States ◽  
Occupational Therapy ◽  
The United States ◽  
Education Programs ◽  
Occupational Therapy Education ◽  
Time Period ◽  
Time Periods ◽  
Therapy Education ◽  
Model Programs ◽  
First Time

This study compared data collected from two questionnaires completed by faculty in professional occupational therapy education programs in the United States. The questionnaires asked respondents to describe their funding requests over two time periods; 1985 through 1987 and 1988 through 1990. The data from the first time period was reported elsewhere (Boyle, Dunn, & Kielhofner, 1990); this article presents the data from the second inquiry and compares the data from the two time periods to show trends. Programs submitted a total of 24 requests intramurally and 194 requests extramurally for a total of 218 requests during the second time period. Programs received full or partial funding for 115 proposals, a total of nearly $15 million, which was an increase of approximately $2 million. Research was funded at $1,865,500 ( n=35), a more than $1 million increase from the first time period. Programs received $5,725,790 for training ( n=35), $28,450 for model programs ( n=2), $1,326,614 for research and demonstration ( n=6), and $5,804,689 for other activities ( n=37).

scholarly journals Occupational Exposures in an Equestrian Centre to Respirable Dust and Respirable Crystalline Silica

2019 ◽  
Vol 16 (17) ◽  
pp. 3226 ◽  
Author(s):  
Kathleen Bulfin ◽  
Hilary Cowie ◽  
Karen S. Galea ◽  
Alison Connolly ◽  
Marie Ann Coggins
Keyword(s):  
Geometric Mean ◽  
Occupational Exposures ◽  
Crystalline Silica ◽  
Dust Control ◽  
Respirable Dust ◽  
Small Scale ◽  
Water Suppression ◽  
Horse Riding ◽  
Increased Risk ◽  
Full Shift

Sand-based products are regularly used as footing material on indoor equestrian arenas, creating a potential occupational exposure risk for respirable crystalline silica (RCS) for equestrian workers training and exercising horses in these environments. The objective of this study was to evaluate an equestrian worker’s personal RCS and respirable dust (RD) exposure. Sixteen personal full-shift RD measurements were collected from an equestrian worker and analysed for RD, quartz and cristobalite. Geometric mean exposures of 0.12 mg m−3 and 0.02 mg m−3 were calculated for RD and RCS concentrations, respectively. RCS exposures of between 0.01 to 0.09 mg m−3 were measured on days when the indoor arena surface was not watered, compared to lower exposures (<LOD-0.03 mg m−3) on days when the indoor arena was watered (p < 0.01); however, manual watering is time intensive and less likely to be implemented in practice. This small-scale study provides new data on RCS and RD exposures among equestrian workers. RCS exposures are within the range considered to be associated with increased risk for lung cancer. The use of dust control solutions such as water suppression should be promoted for equestrian work in horse riding arenas. Equestrian workers need to receive occupational health training on the health risks associated with RCS exposure.

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