Impact of core sample recovery time on accuracy of gas content measurement

Gas content measurement has a significant impact on mine safety and operational efficiency at many Australian underground coal mines. There is an expectation that reported gas content results are accurate and correctly represent the gas content of the coal seam in the area where the coal samples were collected. The practice of some coal sample testing service providers to add ‘correction’ factors to the measured gas content of coal samples increases the reported gas content to account for assumed loss of gas content due to extended recovery time. The methodology used by one gas testing service provider to establish a gas content correction factor to apply to coal samples with extended recovery time has been investigated and discussed. A new approach to testing the impact of extended core sample recovery time on the accuracy of gas content measurement has been developed and is presented. Initial results from testing at three Australian underground coal mines indicates that, for core sample recovery times extending to 180 minutes, there is no discernible loss of gas content that would warrant the addition of a ‘correction factor’

Association between femur size and a focal defect of the superior femoral neck.

Within each sex, there is an association between hip fracture risk and the size of the proximal femur, with larger femurs apparently more susceptible to fracture. Here, we investigate whether the thickness and density of the femoral cortex play a role in this association: might larger femurs harbour focal, cortical defects? To answer this question, we used cortical bone mapping to measure the distribution of cortical mass surface density (CMSD, mg/cm(2)) in cohorts of 308 males and 125 females. Principal component analysis of the various femoral surfaces led to a measure of size that is linearly independent from shape. After mapping the data onto a canonical femur surface, we used statistical parametric mapping to identify any regions where CMSD depends on size, allowing for other confounding covariates including shape. Our principal finding was a focal patch on the superior femoral neck, where CMSD is reduced by around 1% for each 1% increase in proximal-distal size (p<0.000005 in the males, p<0.001 in the females). This finding appears to be consistent with models of functional adaptation, and may help with the design of interventional strategies for reducing fracture risk.KESP acknowledges the support of the NIHR Biomedical Research Centre, Cambridge, and funding from Arthritis Research UK (reference 20109). The MrOS study is supported by National Institutes of Health (NIH) funding. The following institutes provide support: the National Institute on Aging, the National Institute of Arthritis and Musculoskeletal and Skin Diseases, the National Center for Advancing Translational Sciences and the NIH Roadmap for Medical Research, under the following grant numbers: U01 AG027810, U01 AG042124, U01 AG042139, U01 AG042140, U01 AG042143, U01 AG042145, U01 AG042168, U01 AR066160 and UL1 TR000128.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.bone.2015.06.024

Outburst control in the Wongawilli seam

The Wongawilli coal seam varies from 8 m to 10 m thick and consists of interbedded bands of kaolinitic brown mudstone and coal plies. In the southern part of the coalfield, the lower section of the seam is higher quality and lower ash. Dendrobium mines the bottom 3.5 m to 4.0 m of the seam, producing hard coking coal for use in steelmaking. The Wongawilli coal seam varies from 8 m to 10 m thick and consists of interbedded bands of kaolinitic brown mudstone and coal plies. In the southern part of the coalfield, the lower section of the seam is higher quality and lower ash. Dendrobium mines the bottom 3.5 m to 4.0 m of the seam, producing hard coking coal for use in steelmaking. Dendrobium has operated in an historically low gas environment and is now transitioning into a new mining domain that presents new challenges of increasing gas content, increasing CO2 seam gas composition, and low in situ permeability. Dendrobium has an established Outburst Principal Hazard Management Plan, consistent with Industry best practice, that defines standards and requirements for (a) Predicting areas where an outburst risk may exist, (b) Preventing an outburst event from occurring, and (c) Protecting personnel from exposure to an outburst. Dendrobium’s approach to outburst control in the Wongawilli seam is explained, along with a range of initiatives to improve drilling and gas extraction, and to improve the accuracy of identifying outburst risk zones and threshold limit values

Patient-reported outcome assessment of inflammatory arthritis patient experience with intravenously administered biologic therapy

Objective: To evaluate patient perspectives regarding utilization of intravenous (IV) therapy for inflammatory arthritis (IA). Methods: This was a single-center, non-interventional, patient questionnaire-based study of adult IA patients currently receiving IV biologics. At a single visit, patients completed the questionnaire comprising 30 questions centered on their experience receiving an intravenously administered therapy to treat their IA. The questionnaire included questions on patient demographics, disease characteristics, and previous biologic treatment for IA (subcutaneous [SC] and IV). Patients rated their level of agreement with statements regarding satisfaction with current IV biologic therapy and potential advantages and disadvantages of IV biologic therapy using a 5-point Likert scale (1= strongly disagree, 5= strongly agree). Results: One hundred patients were enrolled and completed the survey; 66% were female and the mean age was 58 years. Before IV treatment, 97% of patients received information regarding therapy options. Ninety patients ranked their satisfaction with current IV therapy as 4 or 5. The proportion of patients with an “extremely favorable” perception of IV therapy increased from 33% to 71% following initiation of their current medication. Thirty-one patients had previously received SC therapies to treat their IA. Conclusion: These results demonstrated an overall favorable perception of IV therapy among this patient population. Patients previously treated with SC therapy also had a positive shift in the perception of IV therapy after initiating IV therapy. Patients’ perception and preference for treatment options should be highly considered by the treating physician during or as part of a shared decision-making process. © 2017 Gaylis et al

Mystic Inspiration of Effective Habits?

Although numerous and diverse publications address professors’ writing and research productivity, exceedingly few empirical studies report findings for interventions designed and implemented to increase professors’ research productivity. This study used an innovative mixed methods design with a concurrent triangulation strategy and methods from two research traditions that investigators rarely integrate – quantitative single-case interventions and qualitative inquiry. Processes and findings from this study illustrate how researchers can combine these methods to illuminate the how and why of changes in performance in participant-interventionist studies. In this study, university professors used goal setting and behavioral self-management techniques to increase their daily research productivity and the number of manuscripts they submitted to professional journals. Based on findings and existing literature, we identify practical habits that increase research productivity. This study extends the literature base that includes numerous descriptive articles and opinion pieces on many topics about scholarly productivity, but few intervention studies that report quantitative findings

Lab studies of gas compositions on coal outburst

Coal and gas outburst remains one of the most severe dynamic hazards to many underground coal mining operations worldwide, posing great threats to mine safety and productivity. To understand the influence of gas composition on coal and gas outburst propensity, bulk coal samples were collected from underground coal mine sites in NSW and QLD, and subjected to experimental studies. Isotherm adsorption experiments were carried out using the gravimetric isotherm testing method to investigate the impact of coal seam gas composition on gas adsorption characteristics with a range of coal sample particle sizes, to a maximum gas pressure of 4 MPa, at 35°C. The seam gas composition employed in the tests included 100% CH4, a gas mixture of 50% CH4 and 50% CO2, and 100% CO2. For all test coal samples of different particle sizes, the adsorption capacity of CO2 was observed to be the highest, followed by the CO2/CH4 mixture and CH4. For a given gas content, the equilibrium gas pressure of a CH4 rich coal sample is significantly greater than the equivalent CO2 rich coal sample. Given that gas pressure provides energy to induce outbursts, it is reasonable to suggest that CH4 rich coal contains greater outburst initiating energy. Hysteresis occurs during the CH4 and CO2 sorption and is calculated by an improved hysteresis index (IHI) method. CO2 sorption hysteresis is more significant than CH4 sorption hysteresis, with the ratio of IHI_CO2/IHI_CH4 ranging between 1.50 and 2.25. At equivalent adsorption gas content, the amount of CO2 desorption is less than that of CH4, making it difficult to provide sufficient supply of desorption gas, resulting in low gas desorption energy, which is less conducive to the development of outburst. The research results can provide useful theoretical support for mine site gas management in underground coal mines, particularly those operating in areas with moderate to high composition of CO2 seam gas