Journal of Science and Application Technology (JSAT - Institut Teknologi Sumatera)
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Sleep Deprevation Effect On The Driving Activity Using Sustained Attention Test
Get PDFThe rate of train accidents in Indonesia is still high, mainly caused by humans related to fatigue while on duty. One of the factors that influence the level of fatigue is the duration of the previous sleep time which causes the level of alertness at work to decrease. This study aims to determine how significantly a person alertness performance decreases due to sleep deprivation using Sustained Attention Test. The study was conducted with laboratory experiments using a train simulator involving twelve participants aged 21.2 ± 0.92 years. The independent variable is the duration of sleeping time before driving with a duration of eight hours for normal conditions and a duration of two hours for sleep deprivation. The dependent variable is the parameter on the Sustained Attention Test which is tested before and after driving using the Kruskal-Wallis test. The results showed that there was a increase in the value of the Sustained Attention Test, especially the error and miss parameters which were significant due to sleep deprivation with an average significance of p-value less than 0.05 and increasingly significant with an average of p-value less than 0.01 after driving activity. This shows that sleep deprivation greatly affects the drivers performance while on duty
Penambatan molekul senyawa turunan orizanol terhadap enzim 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reduktase
Get PDFOryzanol has been reported to reduce serum total cholesterol (hypolipidemic agent) by inhibiting HMG-CoA reductase, an enzyme responsible for the metabolic pathway that produces cholesterol and isoprenoid. The purpose of this experiment is to determine the inhibition activity of oryzanol derivatives on HMG-CoA reductase by molecular docking. Four structure of oryzanol derivatives, Lanosteryl-ferulate, Brassicasteryl-ferulate, Lupeol-ferulate, and Cholesteryl-ferulate were used as ligands for molecular docking. The HMG-CoA reductase structure was obtained from protein data bank and the study was performed using AutoDock Tools as a molecular docking software. All oryzanol derivatives show binding affinity against HMG-CoA reductase. Lupeol-ferulate was predicted to be the best inhibitory activity against HMG-CoA reductase because of molecular docking
Pemodelan Pergerakan Harga Saham Bakrie Menggunakan Metode ARIMA (Autoregressive Integrated Moving Average)
Get PDFPeramalan digunakan untuk memprediksi sesuatu yang akan terjadi di masa mendatang sehingga tindakan yang tepat dapat dilakukan. ARIMA merupakan salah satu metode peramalan runtun waktu yang dikembangkan dimana data pengamatan dalam sebuah data runtun waktu diasumsikan berhubungan satu sama lain secara statistik. Tujuan dari penelitian ini adalah untuk membuat model dan meramalkan harga saham PT. Bakrie Sumatera Plantations menggunakan metode ARIMA. Data yang digunakan adalah data harga saham PT. Bakrie Sumatera Plantations selama periode 2 Februari 2020 sampai 27 Juli 2020. Model akhir yang diperoleh adalah ARIMA(1,1,1)(1,0,1)3
Modifikasi Algoritma Kriptografi Klasik dengan Implementasi Deterministic Finite Automata melalui Partisi Pesan Asli berdasarkan Kriteria Pesan Bagian
Get PDFClassical cryptography is study of securing a secret message (plaintext) into a hidden message (ciphertext) which in the process changes each character. The process of converting plaintext into ciphertext is called encryption, the reverse process is called decryption. There is monoalphabetic algorithm, which changes each plaintext letter paired wisely with one particular letter in the ciphertext. The weakness of this algorithm is that the encryption rules can be guessed by analysing the frequency of occurrence of letters. Meanwhile, in polyalphabetic cipher, an algorithm that allows the same letter to be encrypted into different letters. One of them is the Vigenere cipher, which uses keywords that can be repeated to add to the plaintext in the computation of integer modulo. However, this algorithm can be solved using the Kasiski method, because pattern of repeating keywords. In this research, a Deterministic Finite Automata computation model is applied to partition messages before being processed with keywords. Partitions that are formed based on the criteria of message parts ending by the letter E, as letters that often appear in English text. This can increase the security of classical cryptographic algorithms, because they cannot be attacked by frequency analysis or Kasiski methods
Pengaruh Jarak Antar Drain Hole Terhadap Penurunan Muka Air Tanah pada Lereng Tambang Terbuka Batubara
Get PDFThe presence of groundwater on the slopes of the mine, which means that the slopes are saturated with water, will cause a decrease in slope stability. Drain hole is a method that can be applied to decrease groundwater level on a mine slope. This research was conducted to determine the effect of horizontal distance between drain holes on the mine slope on the decrease in groundwater level (groundwater drawdown). Groundwater flow simulation on the slopes of an open pit coal mine with 3 scenarios, without drain holes, 100 m horizontal space between drain holes, and 50 m horizontal space between drain holes, was carried out to answer the goal of this research. The results obtained from the simulation, the third scenario with a distance between drain holes of 50 m has the maximum result compared to the other two scenarios, which are the percentage of groundwater drawdown of 54.1% and groundwater discharge of 167.3 L/s. So it can be concluded that the denser the horizontal distance between the drain holes on the mine slope, the higher the groundwater drawdown on the slope
Pengaruh Liquid Hold-Up terhadap Transisi Pola Aliran 2 Fasa Air-Udara dari Stratified Ke Slug pada Pipa 50 mm
Get PDFThe slug flow pattern is one of the most avoiding factors in piping systems due to its destructive characteristics. Research on the criteria of the slug formation is still the concern. The present study focused on finding out the influence of liquid hold-up toward the transition of the flow pattern from stratified to slug pattern. It was conducted on a 50 mm-diameter horizontal acrylic pipe. The visual data was obtained from a fully developed area (180-210 D) by variations of liquid superficial rate (JL) of 0,03-0,3 m/s and gas superficial rate (JG) from 0,7 to 3,77 m/s. The high-speed camera with 2000 fps recording speed was the instrument to obtain the visual data. The measurement of the liquid hold-up is made by Constant Electric Current Method (CECM). The drastic decrement of liquid hold-up value on the wave growth mechanism (JG ≤ 1,88 m/s) indicated the changes in flow patterns from the stratified to the slug pattern, while on the wave coalescence mechanism (JG > 1,88 m/s) the liquid hold-up remains increases. The pattern change from pseudo slug to the slug pattern was not decreasing on its film thickness, yet, it tends to increase the frequency and the liquid slug length
Analisis Interaksi Aliran Darah dan Pembuluh Serta Pengaruh Kebebasan Mesh Pada Simulasi Hemodinamik Berbasis Metode Elemen Hingga
Get PDFCardiovascular diseases are the world’s leading cause of death with significant death rates caused by abnormalities in vessels such as aneurysms and stenosis. These conditions can potentially cause blockage and thinning of vessels which may lead to heart attack, stroke, and bleedings. Recently, computational simulation methods are frequently used in blood flow analysis. These methods are frequently used in vascular fluid dynamics analysis which relate to the origin of a disease, efficacy prediction in installation of therapeutic instruments and complements the in vitro studies. This article presents an example of a simple vascular simulation to study the effect of blood flow with respect to vascular wall displacement. Furthermore, this research shows the importance of formal CFD pre-processing such as mesh independence testing which influences the simlation accuracy as well as vascular flow prediction and its effects on vascular wall displacement. In this research, it is concluded that the number of mesh elements affects the accuracy of vascular wall shear stress (WSS) calculations with average WSS difference of 0.8 Pa with no significant difference in wall displacement values. An average WSS of 1.95 Pa and a wall displacement of 5.7 µm are obtained from the blood flow simulation in this study
Analisis sedimen dan pengaruhnya terhadap kondisi garis pantai di kawasan pantai timur Kabupaten Lampung Selatan
Get PDFThe erosion and sedimentation process that occurred in the east coast of South Lampung is a natural process affecting the balance of coastal sediment transport and resulting in the instability of coastal lines to the loss of the coastal communities along the coast, such as silting the river and can disturb the traffic of fishing boats. This is seen as a natural process influenced by the magnitude of wave energy coming, the type and size of sediment deposited, and coastal morphology. This research aims to analyze sediment and its effect on the changing coastline. The calculation approach with the empirical formula against coastal sediment data and wave data is used to predict the natural processes occurring along the coast. Analysis of SPOT 6/7 satellite imagery years 2008, 2013, 2016, and 2018 is the next step to estimate the similarity with empirical calculation results. The results showed that the East Coast had a characteristic mud sediment size ranging from 0.0258 – 0033 mm with the highest wave from the east with a wave height above 2.57 m and a period above 8,015 S. Research locations tend to undergo sedimentation processes that are influenced by waves, grain size, and there are rivers carrying sediments and deposits in the river estuary
Studi investigasi adsorpsi oksigen pada permukaan ZnO[111]
Get PDFThe growth of ZnO is an interesting case in the study of functional materials. Adsorption of molecular oxygen onto the surface of Zn-terminated ZnO can be used as a sample case of ZnO crystal growth with its precursors. In this study, we want to see the tendency of molecular oxygen adsorption: whether it is adsorbed as a whole molecule or it is dissociated into the two constituting oxygen atoms before being adsorbed on oxygen adsorption sites for the growth of the crystal. Potential energy surface survey has been carried out on the three configuration of molecular oxygen based on their translational degree of freedom. The configuration of the oxygen molecule with O=O bond axis being normal to the surface tends to be adsorbed wholly as molecule with adsorption energy of 4.11 eV, while the configuration of bond perpendicular to the surface have the tendency to dissociate into individual atoms
Pembuatan film plastik biodegradable dari limbah kulit kopi dengan penambahan kitosan/gliserol
Get PDFBiodegradable plastic production has been developed for a long time by researchers. Data from Ministry of Industry in 2017 stated Indonesia's plastic production reached 3.9 million tons/ year. In this study, the raw materials used came from untapped waste, namely coffee skin, biodiesel-waste glycerol and shrimp-shells chitosan. In this research, biodegradable plastic films have been produced with the addition of glycerol and coffee skin waste with chitosan concentration variations of 0, 2, 4, 6, and 8%. After the optimum conditions were obtained by comparing the elongation and tensile strength values, then the variations in coffee skin waste were added with a weight of 0, 2, 4, 6, and 8 g. Tensile strength and elongation values with variations of chitosan were 0.2-1.87 MPa and 0.22-0.15%, respectively. Whereas the variation of tensile strength and elongation coffee skins were 1.8-0.27 MPa and 0.14-0.2%, respectively. The optimum conditions for producing biodegradable plastic films were obtained with variations of chitosan 4% and 2 g coffee skin with tensile strength and elongation values of 0.98 MPa and 0.16%. The tensile strength and elongation data produced from biodegradable plastic was still below the standard value of commercial plastic or synthetic plastic (HDPE) with values of tensile strength and elongation of 28.64 MPa and 6.5186% respectively