Effects of variogram characteristics of coal permeability on CBM production: a case study in Southeast Qinshui Basin, China

The coalbed methane (CBM) resources of China are located mainly in 9 basins, Ordos, Qinshui, Jungar, Diandongqianxi, Erlian, Tuha, Tarim, Tianshan and Hailaer. Qinshui Basin, one of the richest CBM basins in China, has boosted its annual CBM production to 3 × 109 m3 (106 Bcf). The coal seams in Qinshui Basin are significant with high gas content but strong heterogeneous permeabilities ranging from 0.1 to 10 mD. This paper investigates the effects of spatial distribution characteristics of coal permeability on CBM production. The study area is the South Shizhuang CBM district, Southeast of Qinshui Basin. The distributions of porosity, ash content, coal density and gas content of the coal seam are generated using sequential Gaussian simulation (SGS) with only one realisation because this paper only justifies the effects of coal permeability on CBM production. The permeabilities of 17 wells are determined by matching these wells' water and gas production with bottom-hole pressure as constraint. Then, the distributions of coal permeabilities are generated using SGS with a commercial simulator. The history matched permeabilities range from 1.5 to 12 mD with average of 2.9 mD of the 17 wells. Eight variogram models are used to build the distributions of permeability. The cumulative gas productions of two different well-spacing cases, 300 m and 2000 m, are compared. There are 20 realisations of permeability for each of the eight models. The results show that historical matching can be used to obtain the porosity multipliers and the permeabilities in wells. The major direction of variogram has less effect on the uncertainty of field CBM production than variogram range. The effects of variogram range on the uncertainty of CBM production are positive for the case with short well spacing and vice versa for the case with long well spacing

Gasoline Prices and Their Relationship to Drunk-Driving Crashes

his study investigates the relationship between changing gasoline prices and drunk-driving crashes. Specifically, we examine the effects of gasoline prices on drunk-driving crashes in Mississippi by age, gender, and race from 2004Ð2008, a period experiencing great fluctuation in gasoline prices. An exploratory visualization by graphs shows that higher gasoline prices are generally associated with fewer drunk-driving crashes. Higher gasoline prices depress drunk- driving crashes among younger and older drivers, among male and female drivers, and among white, black, and Hispanic drivers. The statistical results suggest that higher gasoline prices lead to lower drunk-driving crashes for female and black drivers. However, alcohol consumption is a better predictor of drunk-driving crashes, especially for male, white, and older drivers.Drunk-driving crashes, gasoline prices, alcohol consumption, Mississippi

Impact of geological modeling processes on spatial coalbed methane resource estimation

Spatial coalbed methane (CBM) resource estimation is based on spatial distributions of coal, coal adsorbed gas content and coal density. However, the spatial distribution of gas content can be generated via two different geological modeling processes: (1) The gas content distribution is generated by geological modeling based on the interpreted gas content at boreholes; (2) distributions of gas content related logs or coal properties are generated firstly, then the gas content distribution is calculated based on the spatial distributions of logs or coal properties by the relationship between the gas content and logs or coal properties. This paper presents a study to compare the impact of these two processes on CBM resource estimation for coal seam no. 3 (CS-3) in southeast Qinshui Basin, China. Well logs from 22 wells, laboratory data from five wells and well tops from 131 wells for CS-3 are used in log interpretation and geological modeling. The simple kriging (SK) is used to build the structural model and the coal distribution. Weighted and unweighted omni-directional variograms for structural residual and coal thickness are calculated using an in-house program. Logs of gamma-ray (GR) and density (DEN or RHOB) are distributed in 3D by using sequential Gaussian simulation (SGS) with SK algorithm. Artificial neural network (ANN) is used to build the relationship of the measured raw gas content (RGC; gas content in raw coal basis) with the logs of GR, DEN and measured depth (MD). Then the RGC is distributed in 3D by the two geological modeling processes. CBM resources are calculated in 3D based on the cells' volume, coal density and RGC. Results show that RGC increases with an increase in burial depth. Total CBM resources for the study area calculated by these two processes are similar for CS-3 but the distribution probability of high gas content is highly different which is important for locating wells

Further validation of the Health Scale of Traditional Chinese Medicine (HSTCM)

<p>Abstract</p> <p>Background</p> <p>Few health measurement scales are based on Chinese medicine theory. The Health Scale of Traditional Chinese Medicine (HSTCM) was developed to fill this gap. The aim of this study is to validate the HSTCM.</p> <p>Methods</p> <p>A convenience sample of 630 participants was recruited in 11 settings. All participants were asked to complete the HSTCM and World Health Organization Quality of Life Measure-Abbreviated Version (WHOQOL-BREF).</p> <p>Results</p> <p>Properties of the HSTCM were tested. Intra-class correlation coefficient representing the inter-interviewer reliability was 0.99 (95%CI) for the overall instrument. Spearman-Brown correlation coefficient and Cronbach's coefficient alpha were 0.81 and 0.94 respectively, indicating satisfactory internal reliability and inter-interviewer reliability. Spearman's rho correlation coefficient between the HSTCM and WHOQOL-BREFF was -0.67. A receiver operating characteristic (ROC) curve analysis was performed to test the discriminate validation. Areas under the ROC curve analysis for the HSTCM and its domains ranged 0.71–0.87 and all the lower levels of 95%CI were greater than 0.50.</p> <p>Conclusion</p> <p>The HSTCM was validated as a generic health scale and may complement existing health measurement scales in Chinese medicine health care.</p

Values of Different Obesity Indicators in Predicting the Risk of Hyperuricemia：a Comparative Study

BackgroundIn China, hyperuricemia (HUA) is increasingly prevalent, which is often accompanied by multi-system diseases, and has become the second leading metabolic disease after diabetes mellitus. How to effectively contain its prevalence has become an important public health issue that needs to be solved urgently.ObjectiveTo examine relationships of different obesity indices〔waist circumference (WC) , body mass index (BMI) , waist-to-height ratio (WHtR) , body shape index (ABSI) , body roundness index (BRI) , visceral adiposity index (VAI) and lipid aggregation index (LAP) 〕with HUA, and compare their predictive values for HUA, providing a reference basis for early HUA screening and prevention.MethodsCluster sampling was used to recruit physical examinees from the health management center of a grade A tertiary hospital from January to December 2020. Anthropometric indices included in the analysis included WC, BMI, WHtR, ABSI, BRI, VAI and LAP. Binary Logistic regression was used to assess the correlation of HUA with different obesity indices. Receiver operating characteristic (ROC) curve analysis was performed to estimate the predictive values of these indices for HUA with suggested optimal cut-off points presented.ResultsOf the 32 344 physical examinees in total, 13 546 (41.84%) were found with HUA. Men had higher detection rate of HUA than women〔54.11% (10 026/18 530) vs 25.43% (3 520/13 844) 〕 (P&lt;0.001) . The values of all these obesity indices were higher in male HUA patients than in female HUA patients, with statistically significant differences (P&lt;0.001) . Binary Logistic regression showed that after correcting for confounding variables, WC, BMI, WHtR, ABSI, BRI, VAI, and LAP were all statistically associated with HUA occurrence in both men and women (P&lt;0.001) . In men, the area under the ROC curve (AUC) of WC, BMI, WHtR, ABSI, BRI, VAI and LAP in predicting HUA was 0.612, 0.626, 0.602, 0.512, 0.602, 0.617 and 0.642, respectively, with corresponding optimal cut-off points of 80.5 cm, 24.3 kg/m2, 0.48, 0.072, 3.8, 1.4 and 26.7. In women, the AUC for WC, BMI, WHtR, ABSI, BRI, VAI and LAP in predicting HUA was 0.637, 0.636, 0.637, 0.555, 0.638, 0.583, and 0.660, respectively, with corresponding optimal cut-off points of 72.5 cm, 22.7 kg/m2, 0.47, 0.074, 4.2, 1.3 and 15.3. In both male and female physical examinees, the AUC of LAP predicting HUA was higher than the other six obesity indicators (P&lt;0.05) , and the AUC of ABSI predicting HUA was lower than the other six obesity indicators (P&lt;0.05) .ConclusionThese seven obesity indices were all significantly associated with the occurrence of HUA in men and women. The predictive values of them for HUA were different, and LAP may be the best indicator for predicting the risk of HUA in either men or women

Sintering of Iron Ores in a Millipot in Comparison with Tablet Testing and Industrial Process

To explore the feasibility of small-scale sintering pot testing, a \u27millipot\u27 facility (diameter of 53 mm and height of 400 mm) was established and used to examine the sintering performance of iron ores and other non-traditional ferrous materials. The sintering performance of a millipot was examined across a range of different operational conditions (coke rate and suction pressure) and compared with an industrial sinter strand operation. Tablet tests were also performed to assist in the design of the millipot experiments and identify conditions for achieving mineral composition similar to the industrial sinter. For the millipot experiments, the materials used need to be compacted to increase the bulk density, and a higher coke rate is required to compensate the high heat loss caused by wall effects. A higher suction pressure is also necessary to maintain an oxidizing atmosphere in the sinter bed. As expected, it was not possible to eliminate the wall effect, which resulted in more primary hematite at edges of the sintered column. However, the sintered material from the center of column simulates industrial sinter reasonably well. As such, millipot provides a practical way to evaluate the sintering process and material performance at laboratory scale, helping to bridge the gap between tablet sintering and large scale pot sintering, or full scale plant trial. The results of millipot testing can be used for designing larger scale experiments or commercial sintering trials

Enhanced performance of micro deep drawing through the application of TiO2 nanolubricant and graphene lubricants on SUS 301 stainless steel foil

first_pagesettingsOrder Article Reprints Open AccessArticle Enhanced Performance of Micro Deep Drawing through the Application of TiO2 Nanolubricant and Graphene Lubricants on SUS 301 Stainless Steel Foil by Di Pan 1ORCID,Guangqing Zhang 1,Fanghui Jia 1,Yao Lu 2,Jun Wang 2,Zhou Li 3,Lianjie Li 4,Ming Yang 5ORCID andZhengyi Jiang 1,* 1 School of Mechanical, Materials, Mechatronic and Biomedical Engineering, Wollongong, NSW 2522, Australia 2 Welding Engineering and Laser Processing Centre, Cranfield University, Bedfordshire MK43 0AL, UK 3 College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China 4 School of Intelligent Manufacturing and Control Engineering, Shanghai Polytechnic University, Shanghai 201209, China 5 Graduate School of System Design, Tokyo Metropolitan University, Hino, Tokyo 191-0055, Japan * Author to whom correspondence should be addressed. Processes 2023, 11(10), 3042; https://doi.org/10.3390/pr11103042 Received: 2 September 2023 / Revised: 17 October 2023 / Accepted: 20 October 2023 / Published: 23 October 2023 (This article belongs to the Special Issue Processing, Manufacturing and Properties of Metal and Alloys) Downloadkeyboard_arrow_down Browse Figures Versions Notes Abstract In recent years, the quest for effective lubrication in micro deep drawing (MDD) has seen promising advancements. In this study, the influence of TiO2 nanolubricants and graphene lubricants on the performance of 301 stainless steel foil in MDD is examined. The MDD undergoes an extensive evaluation of various lubrication conditions, including dry, TiO2 nanolubricant, graphene lubricant at concentrations of 2.5 mg/mL, 5.0 mg/mL, and 10.0 mg/mL, as well as combined applications of TiO2 and graphene lubricants. Utilising a 5.0 mg/mL graphene lubricant together with TiO2 nanolubricants led to a significant reduction in drawing force, highlighting the synergistic efficacy of this combined lubricant. A pronounced enhancement in the consistency of the produced microcups was also attained. These results emphasise the promise of TiO2 nanolubricant and graphene lubricants in optimising the MDD process

Health-related quality of life and its association with socioeconomic status and diet diversity in Chinese older adults

ObjectivesThe study aimed at examining the combined association of socioeconomic status (SES) and diet diversity (DD) with health-related quality of life (HRQoL) and exploring whether DD played a mediating role in the relationship between varied SES and HRQoL among Chinese older persons.MethodA multi-stage random sampling method was conducted in Shanxi Province of China, with 3,250 older adults participating in this cross-sectional survey. SES was divided into groups by quartiles and DD by means, and these variable groups were combined in pairs to generate a total of eight combinations. The PROCESS macro developed by Hayes was employed for the simple mediation analysis.ResultsCompared with the reference group (those with both high SES and high DD), older adults who were classified to have lower SES or DD had elevated odds of having worse HRQoL: low SES/ low DD (OR = 1.65, 95% CI 1.41–2.92); low SES/ high DD (OR = 1.45, 95% CI 1.17–1.80); middle low SES/ low DD (OR = 1.43, 95% CI 1.24–1.65); middle low SES/ high DD (OR = 1.23, 95% CI 1.03–1.47); upper high SES/ low DD (OR = 1.41, 95% CI 1.21–1.65); and high SES/ low DD (OR = 1.30, 95%CI 1.10–1.53). The mediation analysis revealed that DD mediated the relationship between SES and HRQoL (B=0.011, 95% CI 0.008–0.013), with its indirect effects accounting for 39.29% of the total effects.ConclusionsThese findings highlighted the role of DD as a mediator of the relationship between SES and HRQoL. As DD could be protective, modifiable, and easy for older adults to understand and implement, village clinics and community health stations should work collaboratively to design proper DD intervention measures for better HRQoL

Sensitivity analysis in permeability estimation using logging and injection-falloff test data for an anthracite coalbed methane reservoir in Southeast Qinshui Basin, China

This paper presents a sensitivity analysis in permeability estimation by interpreting injection-falloff test and logging data for a producing coalbed methane field in Southeast Qinshui Basin. Injection-falloff test data are interpreted by an infinitely acting, constant compressibility and radial homogeneous model. Log interpretation is based on the Archie equation using data of shallow laterolog resistivity. The cementation factor of coal is calculated using laboratory measurements. Based on the interpreted cementation factors and the assumed fracture geometries, the sensitivity in permeability estimation using logging data is analyzed. Results show that the permeabilities are 0.041, 0.012 and 0.035. mD for coal seam #3 in wells #W-1, W-5 and W-6, respectively, from the interpretation of injection-falloff test data; the calculated coal cementation factors range widely from 0.9 to 1.8 with average of 1.3. In order to match the log interpretation results with those from injection-falloff tests, different fracture spacing is used in log interpretation for the three wells. The fracture spacing varies from 0.39 to 0.67. mm, and the average fracture aperture varies from 0.229 to 0.398. μm for the three wells. The cementation factor has the highest impact on estimation of permeability if the cementation factor, mud filtrate resistivity and fracture spacing are varied with 10% from the base case. Effect of fracture aperture's heterogeneity on permeability is depending on the standard deviation and average of fracture aperture. Effective permeability has a stronger relationship with geometric mean of face and butt cleats aperture than with total porosity for different face and butt spacing models