scholarly journals Evolution Analysis of Microseismic Events before and after Mining through Large-Scale Weak Zone with High Confined Water

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jing Jia ◽  
Xianjie Hao ◽  
Guanghui Zhao ◽  
Yubao Li ◽  
Xiaoyu Chuai ◽  
...  
Keyword(s):  
Energy Level ◽  
Coal Mining ◽  
Large Scale ◽  
Confined Aquifer ◽  
Confined Water ◽  
Weak Zone ◽  
Joint Influence ◽  
Before And After ◽  
Microseismic Events ◽  
The Difference

The existence of large-scale weak zone will have a great adverse impact on coal mining in high confined aquifer. Taking the Wutongzhuang Coal Mine which is threatened by high-pressure water as an example, this paper studies the difference between the microseismic events before and after mining and analyzes the influence of the large size weak zone on the coal mining on the confined aquifer. The research results show that the microseismic characteristics of the large soft weak belt are small number of events, the spatial distribution of events is concentrated, and the energy level is large. The amplitude of microseismic events is higher, and the proportion of large events in microseismic events is larger than that of small events; the characteristics of microseismic events caused by mining face mining are that the number of events is more, the distribution of events is loose, the distribution of roof and floor is more, the energy level is less, the amplitude is smaller, and the proportion of small and medium events in microseismic events is larger than that of large events. Due to the joint influence of large-scale weak zone of floor and mining, the floor in the middle area of working face is affected by mining, the number of microseismic events in each aquifer increases suddenly, the karst fissures between the aquifers are further developed, and there is a trend of transfixion. Therefore, measures such as floor grouting should be taken to reinforce the large-scale weak zone before mining.

scholarly journals Photogrammetric avalanche volume measurements at Vallée de la Sionne, Switzerland

2001 ◽  
Vol 32 ◽  
pp. 141-146 ◽  
Author(s):  
Juauien Vallet ◽  
Urs Gruber ◽  
François Dufour
Keyword(s):  
Large Scale ◽  
Field Experiments ◽  
Test Site ◽  
Deposition Zone ◽  
Before And After ◽  
Large Scale Field ◽  
Volume Measurements ◽  
Snow Distribution ◽  
The Mean ◽  
The Difference

AbstractDuring winter 1999 three large avalanche events were triggered by explosives at SLF’s avalanche test site, Vallée de la Sionne, canton Valais, Switzerland. One important goal of these large-scale field experiments was to measure the release and deposition volumes of avalanches by photogrammetric methods. In this paper, the photogrammetric measurements of all three avalanches are summarized. For one avalanche event it was possible to realize the whole measuring procedure as planned, and to obtain volume measurements before and after the avalanche triggering In the other two avalanche events, the photographs before the triggering of the avalanche failed. Nevertheless the photographs taken after the avalanche provide valuable information on the fracture depth at the fracture line. The mean fracture depth of the largest avalanche was about 2.10 m, varying between 1 and 3.5 m over a width of > 1000 m. The total volume of the deposition of all three avalanche events was about 1300 000 m3. The deposits are distributed over a length of > 1000 m with depths up to 30 m. The difference between the released and deposited volumes proved that avalanches entrain a large amount of snow along the avalanche track. Furthermore, the snow distribution in the deposition zone provides important information about the behaviour of a dense flowing avalanche in the runout zone.

scholarly journals Metode Kerja Berorientasi Ergonomi pada Proses Pengelapan Kaleng Sarden Menurunkan Keluhan Muskuloskeletal dan Kelelahan Pekerja di PT. BMP Negara, Bali

2019 ◽  
Vol 5 (1) ◽  
pp. 16
Author(s):  
Ni Luh Gede Aris Maytadewi Negara ◽  
I Dewa Putu Sutjana ◽  
Luh Made Indah Sri Handari Adiputra
Keyword(s):  
Large Scale ◽  
Test Group ◽  
Total Sample ◽  
Musculoskeletal Complaints ◽  
Fatigue Score ◽  
Before And After ◽  
Post Test ◽  
The Difference ◽  
The Right ◽  
A Company

Industrial activities developed from households to large-scale industries, including the development of industries in the field of canning fish. Worker health is one of the important things in a company, can be achieved by choosing the right work method. This study was conducted to determine whether ergonomic oriented working methods in the process of wiping canned sardines can reduce musculoskeletal complaints and fatigue in workers. The study design was two period cross over pre and post-test group desig). The research was conducted at PT. BMP Negara. It was held in December 2016. Total sample were 18 workers who wiping cans of sardines. The difference in conditions between before and after activities using ergonomic un-oriented working methods and ergonomic oriented working methods are compared and tested statistically. Comparison tests were carried out on scores of musculoskeletal complaints and worker fatigue. The results showed that ergonomic oriented working methods decreased of musculoskeletal complaints 17.82% (p<0.05) and fatigue score of 11.86% (p<0.05). The conclusion of this study is that ergonomic oriented working methods in the process of wiping sardine cans reduce musculoskeletal complaints and work fatigue of workers in PT. BMP Negara.

scholarly journals The Mechanism Analysis of the Accelerator for Support Vector Regression Based on Data Partition

2020 ◽  
Author(s):  
Yunsheng Song ◽  
Fangyi Li ◽  
Jianyu Liu ◽  
Juao Zhang
Keyword(s):  
Support Vector Regression ◽  
Large Scale ◽  
Real Life ◽  
Support Vector ◽  
Mechanism Analysis ◽  
Data Partition ◽  
Price Forecast ◽  
Before And After ◽  
Important Solution ◽  
The Difference

Support vector regression is an important algorithm in machine learning, and it is widely used in real life for its good performance, such as house price forecast, disease prediction, weather forecast, and so on. However, it cannot efficiently process large-scale data, because it has a high time complexity in the training process. Data partition as an important solution to solve the large-scale learning problem mainly focuses on the classification task, it trains the classifiers over the divided subsets produced by data partition and obtain the final classifier by combining those classifiers. Meanwhile, the most existing method rarely study the influence of data partition on the regressor performance, so that it is difficult to keep its generation ability. To solve this problem, we obtain the estimation of the difference in objective function before and after the data partition. Mini-Batch K-Means clustering is adopted to largely reduce this difference, and an improved algorithm is proposed. This proposed algorithm includes training stage and prediction stage. In training stag, it uses Mini-Batch K-Means clustering to divide the input space into some disjoint sub-regions of equal sample size, then it trains the regressor on each divided sub-region using support vector regression algorithm. In the prediction stage, the regressor merely offers the predicted label for the unlabeled instances that are in the same sub-region. Experiment results on real datasets illustrate that the proposed algorithm obtains the similar generation ability as the original algorithm, but it has less execution time than other acceleration algorithms.

scholarly journals A multi-year methane inversion using SCIAMACHY, accounting for systematic errors using TCCON measurements

2014 ◽  
Vol 14 (8) ◽  
pp. 3991-4012 ◽  
Author(s):  
S. Houweling ◽  
M. Krol ◽  
P. Bergamaschi ◽  
C. Frankenberg ◽  
E. J. Dlugokencky ◽  
...  
Keyword(s):  
Bias Correction ◽  
Large Scale ◽  
Systematic Errors ◽  
Inverse Modelling ◽  
Data Set ◽  
Mixing Ratios ◽  
Before And After ◽  
Modelling Studies ◽  
The Difference ◽  
The Tropics

Abstract. This study investigates the use of total column CH4 (XCH4) retrievals from the SCIAMACHY satellite instrument for quantifying large-scale emissions of methane. A unique data set from SCIAMACHY is available spanning almost a decade of measurements, covering a period when the global CH4 growth rate showed a marked transition from stable to increasing mixing ratios. The TM5 4DVAR inverse modelling system has been used to infer CH4 emissions from a combination of satellite and surface measurements for the period 2003–2010. In contrast to earlier inverse modelling studies, the SCIAMACHY retrievals have been corrected for systematic errors using the TCCON network of ground-based Fourier transform spectrometers. The aim is to further investigate the role of bias correction of satellite data in inversions. Methods for bias correction are discussed, and the sensitivity of the optimized emissions to alternative bias correction functions is quantified. It is found that the use of SCIAMACHY retrievals in TM5 4DVAR increases the estimated inter-annual variability of large-scale fluxes by 22% compared with the use of only surface observations. The difference in global methane emissions between 2-year periods before and after July 2006 is estimated at 27–35 Tg yr−1. The use of SCIAMACHY retrievals causes a shift in the emissions from the extra-tropics to the tropics of 50 ± 25 Tg yr−1. The large uncertainty in this value arises from the uncertainty in the bias correction functions. Using measurements from the HIPPO and BARCA aircraft campaigns, we show that systematic errors in the SCIAMACHY measurements are a main factor limiting the performance of the inversions. To further constrain tropical emissions of methane using current and future satellite missions, extended validation capabilities in the tropics are of critical importance.

scholarly journals The Impact of Covid-19 Pandemic on Adolescence Learning Behavior in Indonesia

2021 ◽  
Vol 22 (1) ◽  
pp. 88-97
Author(s):  
Syiva Fitria ◽  
Dedy Surya
Keyword(s):  
Sedentary Behavior ◽  
Large Scale ◽  
Online Survey ◽  
Learning Behavior ◽  
Significant Difference ◽  
Before And After ◽  
Social Restriction ◽  
The Difference ◽  
The Impact ◽  
Activity Questionnaire

Indonesia is one among many countries applies lockdown or large-scale social restriction in order to suppress transmission rates. The current study examines the impact of COVID-19 pandemic lockdown decision on sedentary behavior among adolescents in Indonesia. An online survey was administered to 255 adolescents on August until October. The online survey consists of questions on demographic information and Adolescence Sedentary Activity Questionnaire (ASAQ). Statistical analysis was performed to compare the difference between total hours spend on performing sedentary behavior before and after the pandemic. A paired sample t-test revealed there was a significant difference in total hours spend on performing sedentary behavior before and after the pandemic (t (254) = -12.8, p<.001). Adolescence is performing more sedentary behavior after the pandemic (M=10.43, SD=3.11) compared to the time before the pandemic (M=8.68, SD=3.47). In conclusion, the covid-19 pandemic cause change on sedentary behavior where there were increase of the total hour adolescence spend on performing sedentary behavior, including a significant change in learning behavior.

scholarly journals Effect of Coal Mining on Springs in the Yushenfu Mining Area of China

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Li-min Fan ◽  
Tao Li ◽  
Maoxi Xiang ◽  
Weizhong He ◽  
Boyun Wu ◽  
...  
Keyword(s):  
Coal Mining ◽  
Large Scale ◽  
Monitoring And Evaluation ◽  
Mining Area ◽  
Water Inflow ◽  
Ecological Effect ◽  
Total Flow ◽  
Watershed Ecology ◽  
Before And After ◽  
Infiltration Recharge

The main purpose of this study was to analyze the effect of coal mining on the springs in the Yushenfu mining area of China. The results of two springs and hydrological surveys conducted in 1994 and 2015 were compared to study the occurrence and evolution of springs before and after large-scale mining. The mechanism of spring evolution and ecological effects of domain evolution were analyzed by combined groundwater monitoring and evaluation of coal mining intensity. The results show that the maximum amount of single water inflow of spring with sand infiltration recharge was more than 10 L/s, the total amount of single water inflow of spring with mixed infiltration recharge was the highest, and the ecological effect of spring with loess infiltration recharge was the most significant. In the study area, 2580 springs (group) were distributed with a total flow of 4998.9428 L/s before 1994 and 376 residual springs (group) were present with a total flow of 996.392 L/s in 2015. Large-scale mining decreased the regional groundwater level, thus decreasing the amount of spring water. The high intensity of mining decreased the number of springs (group) and area of water and wetland in the study area. This directly affected the watershed ecology; the ecological degradation was significant.

scholarly journals A multi-year methane inversion using SCIAMACHY, accounting for systematic errors using TCCON measurements

2013 ◽  
Vol 13 (10) ◽  
pp. 28117-28171 ◽  
Author(s):  
S. Houweling ◽  
M. Krol ◽  
P. Bergamaschi ◽  
C. Frankenberg ◽  
E. J. Dlugokencky ◽  
...  
Keyword(s):  
Bias Correction ◽  
Large Scale ◽  
Systematic Errors ◽  
Inverse Modelling ◽  
Data Set ◽  
Mixing Ratios ◽  
Before And After ◽  
Modelling Studies ◽  
The Difference ◽  
The Tropics

Abstract. This study investigates the use of total column CH4 (XCH4) retrievals from the SCIAMACHY satellite instrument for quantifying large scale emissions of methane. A unique data set from SCIAMACHY is available spanning almost a decade of measurements, covering a period when the global CH4 growth rate showed a marked transition from stable to increasing mixing ratios. The TM5 4DVAR inverse modelling system has been used to infer CH4 emissions from a combination of satellite and surface measurements for the period 2003–2010. In contrast to earlier inverse modelling studies, the SCIAMACHY retrievals have been corrected for systematic errors using the TCCON network of ground based Fourier transform spectrometers. The aim is to further investigate the role of bias correction of satellite data in inversions. Methods for bias correction are discussed, and the sensitivity of the optimized emissions to alternative bias correction functions is quantified. It is found that the use of SCIAMACHY retrievals in TM5 4DVAR increases the estimated inter-annual variability of large-scale fluxes by 22% compared with the use of only surface observations. The difference in global methane emissions between two year periods before and after July 2006 is estimated at 27–35 Tg yr−1. The use of SCIAMACHY retrievals causes a shift in the emissions from the extra-tropics to the tropics of 50 ± 25 Tg yr−1. The large uncertainty in this value arises from the uncertainty in the bias correction functions. Using measurements from the HIPPO and BARCA aircraft campaigns, we show that systematic errors are a main factor limiting the performance of the inversions. To further constrain tropical emissions of methane using current and future satellite missions, extended validation capabilities in the tropics are of critical importance.

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

The Effect of Active Site-inhibited Factor VIIa on Tissue Factor-initiated Coagulation Using Platelets before and after Aspirin Administration

1997 ◽  
Vol 78 (04) ◽  
pp. 1202-1208 ◽  
Author(s):  
Marianne Kjalke ◽  
Julie A Oliver ◽  
Dougald M Monroe ◽  
Maureane Hoffman ◽  
Mirella Ezban ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Active Site ◽  
Large Scale ◽  
Thrombin Generation ◽  
Factor Viia ◽  
Dependent Manner ◽  
Antithrombotic Agent ◽  
Before And After ◽  
Ic50 Values

SummaryActive site-inactivated factor VIIa has potential as an antithrombotic agent. The effects of D-Phe-L-Phe-L-Arg-chloromethyl ketone-treated factor VIla (FFR-FVIIa) were evaluated in a cell-based system mimicking in vivo initiation of coagulation. FFR-FVIIa inhibited platelet activation (as measured by expression of P-selectin) and subsequent large-scale thrombin generation in a dose-dependent manner with IC50 values of 1.4 ± 0.8 nM (n = 8) and 0.9 ± 0.7 nM (n = 7), respectively. Kd for factor VIIa binding to monocytes ki for FFR-FVIIa competing with factor VIIa were similar (11.4 ± 0.8 pM and 10.6 ± 1.1 pM, respectively), showing that FFR-FVIIa binds to tissue factor in the tenase complex with the same affinity as factor VIIa. Using platelets from volunteers before and after ingestion of aspirin (1.3 g), there were no significant differences in the IC50 values of FFR-FVIIa [after aspirin ingestion, the IC50 values were 1.7 ± 0.9 nM (n = 8) for P-selectin expression, p = 0.37, and 1.4 ± 1.3 nM (n = 7) for thrombin generation, p = 0.38]. This shows that aspirin treatment of platelets does not influence the inhibition of tissue factor-initiated coagulation by FFR-FVIIa, probably because thrombin activation of platelets is not entirely dependent upon expression of thromboxane A2.

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