Studi Pengaruh Ukuran Butir Terhadap Porositas dan Konduktivitas Hidrolik Batupasir dan Batulempung (Study of The Effect of Grain Size on Porosity and Hydraulic Conductivity of Sandstone and Claystone)

AbstrakPorositas dan konduktivitas hidrolik berhubungan langsung dengan aktivitas penambangan, di antaranya pembuatan jalan tambang (ramp) pada front area penambangan. Proses penambangan yang menyebabkan pori-pori tanah semakin kecil (ruang pori berkurang) sehingga porositas mengecil disebabkan pengaruh ukuran butir. Untuk mengetahui pengaruh ukuran butir terhadap porositas batupasir dan batulempung serta pengaruhnya juga klasifikasi nilai porositas dan konduktivitas hidrolik batupasir dan batulempung ini, metode yang digunakan ialah analisis ukuran butir untuk mengetahui besarnya ukuran butir dan jenis batuan menggunakan skala Wentworth (1992) kemudian pada analisis porositas menggunakan pengujian sifat fisik, dilakukan untuk mencari nilai yang berpengaruh terhadap kekuatan batuan seperti natural density, dry density, saturated density, apperent specific gravity, true specific gravity, specific gravity, natural water content, saturated water content, derajat kejenuhan, porositas dan void ratio (Arif, 2016). Pada ada analisis konduktivitas hidrolik digunakan alat permeameter untuk mengetahui kecepatan air dalam satuan (meter/detik) dari sampel batupasir dan batulempung dengan jumlah 10 sampel berbentuk coring.Hasil penelitian menunjukkan bahwa nilai ukuran butir batupasir adalah 1/8 atau 0,125 mm sedangkan batulempung adalah 1/256 atau 0,003 mm. Analisis porositas yang dilakukan pada sampel daerah penelitian menunjukkan persentase rata-rata 87,44 % untuk sampel batupasir dan 77,95 % untuk batulempung. Sedangkan dari hasil uji konduktivitas hidrolik batupasir didapatkan hasil 5,71 × 10-9 meter/detik dan 5,74 × 10-9 meter/detik.Kata Kunci: Ukuran Butir, Porositas, Konduktivitas Hidrolik, Batupasir, Batulempung  AbstractPorosity and hydraulic conductivity are directly related to mining activities, including the construction of a minerampon the front of the mining area. The mining process causes the soil pores to get smaller (reduced pore space) so that the porosity decreases due to the influence of grain size. To determine the effect of grain size on the porosity of sandstones and claystones as well as its influence on the classification of porosity and hydraulic conductivity values of sandstones and claystones, the method used is grain size analysis to determine the size of grains and rock types using the Wentworth scale (1992) then porosity analysis using the Wentworth (1992) scale. Physical property testing is carried out to find values that affect rock strength such as natural density, dry density, saturated density, apperent specific gravity, true specific gravity, specific gravity, natural water content, saturated water content, degree of saturation, porosity and void ratio ( Arif, 2016). In the hydraulic conductivity analysis, a permeameter was used to determine the water velocity in units (meters/second) of sandstone and claystone samples with a total of 10 coring.The results showed that the value of the grain size of the sandstone was 1/8 or 0.125 mm while the claystone was 1/256 or 0.003 mm. Porosity analysis performed on the sample of the study area showed an average percentage of 87.44% for the sandstone sample and 77.95% for the claystone. Meanwhile, from the results of the hydraulic conductivity of sandstone, the results were 5.71 × 10-9   meters/second and 5.74 × 10-9 meters/second.Keywords: Grain Size, Porosity, Hydraulic Conductivity, Sandstone, Clayston

The aesthetics of Instagram: Exploring the aesthetics of visual and semantic aspects of Instagram

The article presents the results of an aesthetic study of content and visual forms on Instagram, a relatively new social media platform. The study focuses on how the products of digital technology, understood as new artifacts within the postmodern aesthetic framework, have been taken up within the digital culture. The results of the research help us to understand the characteristics of this new social media platform, indicating that Instagram has been highly successful in changing aesthetic criteria and standards and creating new aesthetic forms and content

Experimental investigation of leading-edge roughness effects on stationary crossflow instability of a swept wing

AbstractWind tunnel experiments were conducted to evaluate surface pressure distribution over a semi span swept wing with a sweep angle of 33°. The wing section has a laminar flow airfoil similar to that of the NACA 6-series. The tests were conducted at speeds ranging from 50 to 70 m/s with and without surface roughness. Surface static pressure was measured on the wing upper surface at three different chordwise rows located at the inboard, middle, and outboard stations. The differences between pressure distributions on the three sections of the wing were studied and the experimental results showed that roughness elements do not influence the pressure distribution significantly, except at the inboard station. On the other hand, spectral analysis of the pressure–time signals acquired from the pressure orifices over the wing upper surface showed that roughness had significantly affected the zero frequency amplitude. In this study, the zero frequency amplitude and its variations with roughness elements was investigated at three different chordwise positions; inboard, middle, and outboard stations. Results showed that the 3-D roughness elements amplified zero frequency amplitude over the wing surface. Zero frequency distribution at the inboard station, closer to the wing root, in comparison with the middle station, was reduced after an initial amplification along the chord. Moreover, the effect of roughness on the zero frequency instability at the first section was negligible due to the narrow instability amplification region. On the other hand, at the outboard station, closer to the wing tip, the instabilities were amplified over a larger region, with respect to the middle station

Application of Phylogenetic Analysis in the Study of Mitochondrial Genetic Diseases

Mitochondrial genetic diseases are receiving increasing attention. However, the common case-control methods are susceptible to genetic background, population stratification, data quality and other factors that may lead to false positive results. The field of genetic diseases has not been paid enough attention. Therefore, this paper reviews this method and promotes the extensive and in-depth use of mitochondrial gene

An experimental study of the effects of swept angle on the boundary layer of the 2D wing

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.dc201

APPLICATION OF ARTIFICIAL NEURAL NETWORKS IN ESTIMATING PARTICIPATION IN ELECTIONS

ABSTRAC

Effect of second wing on the surface pressure of an MAV model

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.In this study surface pressure distribution over a Zimmerman type wing generally used for the MAV models in the presence of a second wing located on the top of the main wing was experimentally investigated. The model was tested in a low speed, low turbulence tunnel. Surface pressure data for various angles of attack and Reynolds numbers in the presence of the second wing is obtained. In addition, all data were repeated for the different locations, vertical and horizontal, positions of the second wing. The data are compared with those of the main wing alone. By comparing the surface pressure data for various cases one can clearly identify the best location, vertical and longitudinal, of the second wing. From the pressure data, it is seen that addition of the second wing affects the flow field over the main wing considerably. It increases the surface pressure distribution in front portion of the main wing, unfavourable effect, while it has a favourable effect in the rear portion of the wing.dc201