14 research outputs found

    Pengaruh Kepemimpinan Kepala Madrasah, Iklim Kerja, Motivasi Kerja dan Kompetensi Pedagogik terhadap Kinerja Guru Madrasah Tsanawiyah Negeri di Kabupaten Lampung Selatan

    Get PDF
    Efforts to improve the quality and the quality of madrasah can be done through various means. One way that can be done to set up a professional and competence madrasah teacher, who have high performance. Performance teachers madrasah Tsanawiyah country in South Lampung is influenced by various factors. In this study, there are several factors that are considered an impact on teacher performance madrasah Tsanawiyah State of South Lampung regency, the headmaster leadership, work climate and work motivation and pedagogical competence of teachers. The research objective is to find and acquire empirical evidence of: 1)the effect of head master leadership on teacher performance madrasah Tsanawiyah country in South Lampung regency. 2) The influence of climate on the performance of works Madrasah Tsanawiyah country teachers in SouthLampung regency. 3) The effect of work motivation on the performance of domestic Tsanawiyah madrassa teachers in South Lampung regency. 4) Effect of pedagogical competence of the teacher's performance Tsanawiyah country madrassa in South Lampung regency , and 5) Effect of head master leadership,work climate, motivation and pedagogical competency in together on teacher performance Madrasah Tsanawiyah country in South Lampung regency. This study was conducted using a quantitative approach and field survey method. The population is all public junior secondary madrasah teacher in South Lampung regency totaling 143 people and the entire population will be sampled in this study. The research data were collected through a uestionaire and analyzed using descriptive statistical techniques and analysis track or path analysis. Based on data analysis it is found and concluded as follows: First,there is a significant influence on the performance leadership teachers Madrasah Tsanawiyah country in South Lampung regency of 19.20% with strength of 0.438 and a correlation co-efficient of 0.267 path. Second, there is a significant direct effect on the performance of the work climate madrasah Tsanawiyah country teachers in South Lampung regency of 26.50% with strength of 0.515 and a correlation co-efficient of 0.076 paths. Third, there is a very significant direct effect on the performance of teachers' work motivation madrasah Tsanawiyah country in South Lampung regency of 29.10% with strength of 0.539 and a correlation co-efficient of 0.412 paths. Fourth, there is the indirect effect that pedagogical competence of the teachers’ performance madrasah Tsanawiyah country in South Lampung regency of 6.80% with a power of 0,260 correlations and path coefficient of -0.043. Fifth, there is a significant influence headmaster leadership, work climate, motivation and pedagogical competence together with the teacher performance madrasah Tsanawiyah country in South Lampung regency of 36.70% with strength of 0.605 and a correlation co-efficient of 1.649 paths

    Multi-scale 3D Imaging for Characterization of Microstructural Properties of Gas Shales

    Get PDF
    In recent years, gas shale has attracted renewed attention as an unconventional energy resource, with massive, fast-growing, and largely untapped reserves. Shale is a fine-grained sedimentary rock containing a high content of organic matter (kerogen) from which gas can be extracted. The identification of the pore structure and quantification of the geometry, sizes, volume, connectivity, and distribution of extremely fine-grain pores, kerogen, and minerals are all extremely significant for the characterization of gas shale reservoirs. These features determine fluid flow and ultimate hydrocarbon recovery, however, they are also highly challenging to determine accurately. X-ray micro and nano-computed tomography (μ-CT and Nano-CT) combined with 3D focused ion beam scanning electron microscopy (FIB-SEM) are used in this thesis to address this challenge and to provide more information for understanding the complex microstructures in 3D from multiple scales within shale samples. In this thesis, state-of-the-art multi-scale imaging with multi-dimensional potential was applied to the image and quantified the microstructures' properties of gas shale. Samples were first imaged with X-ray micro-and nano-tomography (μ-CT and Nano-CT), and then with Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) measurements. Results of image analysis using SEM (2D), μ-CT (3D), ultrahigh-resolution Nan-CT (3D), and FIBSEM (3D) under backscattered electron (BSE) images reveal a complex fine-grained structure at specified phases such as pores, kerogen, and minerals within samples. The results show low connectivity of pores and high connectivity of kerogen which suggests that porous gas flow through samples used in this study cannot be the main transport through the pores. This implies that the gas transport through the pores is unlikely to be important, but cannot be ignored, as it is very important and constitutes the basis for understanding permeability in the rock. However, the high connectivity of kerogen provides the potential pathways for gas flow throughout the whole sample. The combination of multiscale 3D X-ray CT techniques (micro-nano) with 3D FIB-SEM provides a powerful combination of tools for quantifying microstructural information including pore volume, size, pore aspect ratio and surface area to volume distributions, porosity, permeability in shales, and also allowing the visualization of pores, kerogen and minerals phases over a range of scales. Other methods, such as physical measurements Gas Research Institute (GRI), mercury injection (MIP), and nitrogen adsorption (N2) are also presented in this study. The combination of these data sets has allowed the examination of the microstructure of the shale in unprecedented depth across a wide range of scales (from about 20 nm to 0.5 mm). Overall, the shale samples from Bowland shale formation shows a porosity of 0.10 ± 0.01%, 0.52 ± 0.05%, and 0.94 ± 0.09% from three FIB-SEM measurements, 0.67 ± 0.009% from the nano-CT data and 0.06 ± 0.008% from one μ-CT measurement, which compare with 0.0235 ± 0.003% from nitrogen adsorption, and 0.60 ± 0.07% from MIP. The porosity was also observed to be 0.43± 0.009% and 0.7% ± 0.007% for FIB-SEM and Nano-CT methods, respectively in different shale reservoirs from a Sweden formation. The data vary due to the different scales at which each technique interrogates the rock and whether the pores are openly accessible (especially in the case of nitrogen adsorption). The measured kerogen fraction is 32.4 ± 1.45% from nano-CT compared with 34.8 ± 1.74%, 38.2 ± 1.91%, 41.4 ± 2.07%, and 44.5 ± 2.22% for three FIB-SEM and one μ-CT measurement. The pore size imaged by nano-CT ranged between 100 and 5000 nm, while the corresponding ranges were between 3 and 2000 nm for MIP analysis and between 2 and 90 nm for N2 adsorption. The distribution of pore aspect ratio and scale-invariant pore surface area to volume ratio (σ) as well as the calculated permeability shows the shale sample in this study to have a high shale gas potential. Aspect ratios indicate that most of the pores that contribute significantly to pore volume are oblate, which is confirmed by the range of σ (3−30). Oblate pores have greater potential for interacting with other pores compared to needle-shaped prolate pores as well as optimizing surface area for the gas to desorb from the kerogen into the pores. Permeability has also been calculated and values of 2.61 ± 0.42 nD were obtained from the nano-CT data, 2.65 ± 0.45 nD from MIP, 13.85 ± 3.45 nD, 4.16 ± 1.04 nD, and 150 ± 37.5 nD from three FIB-SEM measurements and 2.98 ± 0.75 nD from one μ-CT measurement, which are consistent with expectations for generic gas shales (i.e., tens of nD). The quantitative results of 2D and 3D imaging datasets across nm-μm-mm length scales provided a view of understanding the heterogeneous rock types, as well as great value to better understand, predict and model the pore structure, hydrocarbon transport, and production from gas shale reservoirs

    Fluid Flow and Microstructural Properties of Gas Shales

    No full text
    In recent years, the production of natural gas and oil from shale has had a dramatic impact on the gas and oil industries, with shale gas plays the biggest source of natural gas in, for example, the USA (US Energy Information Administration, 2016). There has been a consequential and considerable increase in demand for better characterization of shale gas plays. However, cost-effective shale gas production requires detailed knowledge of the petrophysical characteristics of the shale from which the gas is extracted. Parameters such as the kerogen fraction, pore size distributions, porosity, permeability, the frackability of the rock and the degree to which natural fracturing already occurs are required in order to be able to estimate potential gas reserves and how easily it can be extracted. Characterization of shale gas plays is challenging because of they tend to be both tight and heterogeneous due to the mechanisms by which they are deposited and subsequent diagenetic processes and also due to the small size of the pores and low permeability, porosity. SEM imaging has confirmed the tremendous physical heterogeneity of shale gas plays ( Charmers et al., 2009; Loucks et al., 2009; Wang et al., 2009; Ambrose et al., 2010; Curtis et al., 2010). Strong characterization of a reservoir necessitates detailed knowledge of, for example, flow capabilities, permeability, porosity, pore connectivity and storage. Knowledge of these characteristics will help to determine flow capacity, how to control gas extraction, and hydrocarbon storage. Permeability and porosity are two principal parameters required for accurate assessment of gas-/oil-in-place to forecast production. The measurement of porosity is considered to be relatively straightforward; numerous tests have been used successfully, including helium porosity. On the other hand, the measurement of permeability is more challenging. For instance, steady-state measurements which have been used successfully with more typical reservoirs are not easy to use with shale samples, for which more complex, unsteady-state methods including pulse-decay are required (Javadpour and Ettehadtavakkoli 2015). Measurement of low permeability’s using pulse-decay is considered a good method for measurement of permeability of shale rock samples (Jones, 1997) but has a number of drawbacks such as being relatively expensive, and results can depend on sample size. Thus, other methods are required for confirmatory analysis of permeability and pore systems in shale rock samples

    Nano-Scale Characterization of Particulate Iron Pyrite Morphology in Shale

    Get PDF
    This study analyzes the morphology of iron pyrite particles within a shale sample captured using nano-computed tomography (Nano-CT). The complex, framboidal morphology of the iron pyrite particles is characterized using various metrics, and comparisons are drawn on their effectiveness to quantify their observed morphological characteristics. Then, simplified representations of selected iron pyrite particles are generated to facilitate a sensitivity analysis of the effect of imaging resolution on morphological parameters of particle form. A discussion is developed on the required number of pixels per particle diameter for particle shape characterization. It is shown that shape indices that rely on the simplified main particle dimensions can be accurately calculated even for low fidelity levels of 10 pixels per particle diameter. More complex shape indices that use vertices, volume, and surface area, are more sensitive to image resolution, even for 40 pixels per particle diameter

    Integration of Multiscale Imaging of Nanoscale Pore Microstructures in Gas Shales

    No full text
    Quantification of the microstructures of shales is difficult due to their complexity which extends across many orders of magnitude of scale. Nevertheless, shale microstructures are extremely important, not only as shale gas resources but also as cap rocks in CCS resources, in geothermal reservoirs, and as a host to the long-term storage of radioactive materials. In this work, we have performed ultrahigh-resolution CT imaging (nano-CT), mercury injection porosimetry (MIP), and nitrogen adsorption experiments on a sample of gas shale for which we already have focused ion beam scanning electron microscopy (FIB-SEM) and high-resolution CT (micro-CT) data sets. The combination of these data sets has allowed us to examine the microstructure of the shale in unprecedented depth across a wide range of scales (from about 20 nm to 0.5 mm). Overall, the sample shows a porosity of 0.67 ± 0.009% from the nano-CT data, 0.0235 ± 0.003% from nitrogen adsorption, and 0.60 ± 0.07% from MIP, which compare with 0.10 ± 0.01%, 0.52 ± 0.05%, and 0.94 ± 0.09% from three FIB-SEM measurements and 0.06 ± 0.008% from one micro-CT measurement. The data vary due to the different scales at which each technique interrogates the rock and whether the pores are openly accessible (especially in the case of the nitrogen adsorption value). The measured kerogen fraction is 32.4 ± 1.45% from nano-CT compared with 34.8 ± 1.74%, 38.2 ± 1.91%, 41.4 ± 2.07%, and 44.5 ± 2.22% for three FIB-SEM and one micro-CT measurement. The pore size imaged by nano-CT ranged between 100 and 5000 nm, while the corresponding ranges were between 3 and 2000 nm for MIP analysis and between 2 and 90 nm for N2 adsorption. The distribution of pore aspect ratio and scale-invariant pore surface area to volume ratio (σ) as well as the calculated permeability shows the sample to have a high shale gas potential. Aspect ratios indicate that most of the pores that contribute significantly to pore volume are oblate, which is confirmed by the range of σ (3–13). Oblate pores have greater potential for interacting with other pores compared to equant and needle-shaped prolate pores as well optimizing surface area for gas to desorb from the kerogen into the pores. Permeability essays provide 2.61 ± 0.42 nD from the nano-CT data, 2.65 ± 0.45 nD from MIP, and (5.07 ± 0.02) × 10–4 nD from nitrogen adsorption, which are consistent with expectations for generic gas shales (i.e., tens of nD) and the measurements made previously on the same sample using FIB-SEM and micro-CT imaging techniques
    corecore