Pengaruh Jarak Anoda-Katoda dan Durasi Pelapisan terhadap Laju Korosi pada Hasil Electroplating Hard Chrome

Electroplating hard chrome merupakan pelapisan permukaan logam yang biasa digunakan untuk industri dengan tujuan meningkatkan umur pakai (lifetime). Jarak anoda-katoda dan durasi pelapisan adalah salah satu faktor yang menentukan kualitas hasil electroplating hard chrome, sedangkan pengujian laju korosi merupakan faktor koreksi terhadap hasil electroplating untuk didapatkan umur pakai. Penelitian ini dilakukan menggunakan metode penelitian eksperimen sejati dengan melibatkan satu variabel bebas yaitu jarak anoda-katoda dengan variasi yang digunakan adalah 9 cm, 12 cm, 15 cm, dan 18 cm, sedangkan variabel terikat yang diamati yaitu uji laju korosi hasil electroplating hard chrome. Variabel terkontrol pada penelitian ini adalah durasi pelapisan selama 45 menit dan 60 menit. Komposisi larutan elektrolit yang digunakan yaitu chromic acid 300 gr/L dan asam sulfat 3 gr/L, dengan rapat arus 45 A/dm2 dan temperatur elektrolit 50oC. Hasil penelitian menunjukkan bahwa jarak anoda-katoda dan durasi pelapisan electroplating hard chrome pada baja ST-37 berpengaruh secara nyata terhadap hasil uji laju korosi atau Corrosion Penetration Rate (CPR)

Multi-directional gated recurrent unit and convolutional neural network for load and energy forecasting: A novel hybridization

Energy operations and schedules are significantly impacted by load and energy forecasting systems. An effective system is a requirement for a sustainable and equitable environment. Additionally, a trustworthy forecasting management system enhances the resilience of power systems by cutting power and load-forecast flaws. However, due to the numerous inherent nonlinear properties of huge and diverse data, the classical statistical methodology cannot appropriately learn this non-linearity in data. Energy systems can appropriately evaluate data and regulate energy consumption because of advanced techniques. In comparison to machine learning, deep learning techniques have lately been used to predict energy consumption as well as to learn long-term dependencies. In this work, a fusion of novel multi-directional gated recurrent unit (MD-GRU) with convolutional neural network (CNN) using global average pooling (GAP) as hybridization is being proposed for load and energy forecasting. The spatial and temporal aspects, along with the high dimensionality of the data, are addressed by employing the capabilities of MD-GRU and CNN integration. The obtained results are compared to baseline algorithms including CNN, Long Short-Term Memory (LSTM), Bidirectional Long Short-Term Memory (Bi-LSTM), Gated Recurrent Unit (GRU), and Bidirectional Gated Recurrent Unit (Bi-GRU). The experimental findings indicate that the proposed approach surpasses conventional approaches in terms of accuracy, Mean Absolute Percentage Error (MAPE), and Root Mean Square Error (RSME).</p> </abstract&gt

Optimization Study of Preparation Eucalyptus Trees Activated Carbon for Removal of Methylene Blue Dye from Aqueous Solution

Mesoporous activated carbon were  prepared from eucalyptus trees stalks (ES) using physiochemical activation method, which  consisted of potassium hydroxide (KOH) treatment and carbon dioxide (CO2) gasification. Based on the central composite design (CCD), two factor interaction (2FI) and quadratic models were respectively employed to correlate preparation of the activated carbon with these variables. The effects of the activation temperature, activation time and chemical impregnation ratios on the carbon yield and methylene blue removal were investigated. From the analysis of variance (ANOVA), the most influential factor on each experimental design response was identified. The optimum conditions for preparing activated carbon from eucalyptus stalks were found to be activation temperature of 650 oC, activation time of 0.5 h and chemical impregnation ratio of 2.5. The carbon yield was found to be 22.3% while the removal of methylene blue was found to be 89%. Keywords: Eucalyptus stalks; Optimization; Activated carbon; Adsorption; Methylene blue.

Optimization of low pre-operative hemoglobin reduces transfusion requirement in patients undergoing transurethral resection of prostate

Objective: To identify factors that influence peri-operative hemorrhage in view of reducing the need for transfusions in patients undergoing trans uretheral resection of prostate (TURP). Methods: All patients undergoing TURP between January 1997 and December 1999 were identified using lCD 9CM coding and indexing system. Overall 430 patients were identified, however, 384 charts were included and reviewed for demographics, pre and intra-operative data and post-operative morbidity. Patients were divided into two groups on the basis of presence of significant hemorrhage. Results: Overall 384 patients were analyzed. Nineteen patients had hemorrhage - group I whereas 365had no significant hemorrhage - group II. Mean age and co-morbidities in the two groups were similar. However, in group I, 58% presented with urinary retention compared to 33% in group II. In group I, factors that reached statistical significance include; operative time (pConclusion: Operative time, weight of resected prostate tissue are inter related and are only partly controllable. Low pre-operative hemoglobin is the only reversible factor in reducing transfusion following TURP (JPMA 53:1 04;2003)

Hydrodynamics and Kinetics of Phenols Removal from Industrial Wastewater in a Trickle Bed Reactor (Part I: Hydrodynamic Study)

An experimental investigation of the hydrodynamic parameters in a trickle bed reactor is presented. The operating conditions are selected for the operating system to be at trickle flow regime. The effects of the two-phase flow rates, reactor pressure and temperature on the pressure drop, external liquid holdup and liquid axial dispersion are discussed. Pressure drop was measured using differential pressure transducer, while liquid holdup and axial dispersion were estimated using RTD technique with a reactive dye as a tracer. The results confirmed that pressure drop is proportional to flow rate of fluids and operating pressure while it is inversely proportional to temperature. Liquid flow rate has a proportional effect on liquid holdup and axial dispersion while gas flow rate and temperature presented a different image. A comparison between the results of present work and that of literature is presented and discussed. Empirical correlations for pressure drop, liquid holdup and axial dispersion with operating conditions are developed with correlation coefficient of 98.4 to 99.7 %

Nozzle Wear and Pressure Rise in Heating Volume of Self-blast Type Ultra-high Pressure Nitrogen Arc

This paper reports on experiments with ultra-high pressure nitrogen arcs in a self-blast type switch design. The effect of filling pressure on nozzle mass loss and pressure-rise in the heating volume were investigated. An arc current peak of 130 A at 190 Hz and a fixed inter-electrode gap of 50 mm were used throughout the experiment. The arc burns inside a polytetrafluoroethylene nozzle with a gas outflow vent in the middle. Nitrogen filling pressure of 1 bar, 20 bar, and 40 bar was tested, which also covers the supercritical region. Moreover, to study the effect of vent size on blow pressure near current zero, three different vent dimensions were investigated. By increasing the filling pressure, the energy deposited in the arc increases as a result of increased arcing voltage. It was observed that the pressure-rise in the heating volume is linked to the filling pressure, while the vent size plays a crucial role in the blow pressure near current zero. The nozzle mass loss per unit energy deposited in the arc is found to be independent of the filling pressure

Structural insight into the TRIAP1/PRELI-like domain family of mitochondrial phospholipid transfer complexes

The composition of the mitochondrial membrane is important for its architecture and proper function. Mitochondria depend on a tightly regulated supply of phospholipid via intra-mitochondrial synthesis and by direct import from the endoplasmic reticulum. The Ups1/PRELI-like family together with its mitochondrial chaperones (TRIAP1/Mdm35) represent a unique heterodimeric lipid transfer system that is evolutionary conserved from yeast to man. Work presented here provides new atomic resolution insight into the function of a human member of this system. Crystal structures of free TRIAP1 and the TRIAP1–SLMO1 complex reveal how the PRELI domain is chaperoned during import into the intermembrane mitochondrial space. The structural resemblance of PRELI-like domain of SLMO1 with that of mammalian phoshatidylinositol transfer proteins (PITPs) suggest that they share similar lipid transfer mechanisms, in which access to a buried phospholipid-binding cavity is regulated by conformationally adaptable loops

1,3,6-Trimethyl­pyrano[4,3-b]pyrrol-4(1H)-one

All the non-H atoms of the title compound, C10H11NO2, are almost coplanar [maximum deviation = 0.040 (3) Å]. The crystal structure is stabilized by C—H⋯O hydrogen bonds

A novel hepatitis C virus (HCV) subtype from Somalia and its classification into HCV clade 3.

Hepatitis C virus (HCV) sequences from throughout the world have been grouped into six clades, based on recently proposed criteria. Here, the partial sequences and clade assignment are reported for three HCV isolates from chronic hepatitis C patients from Somalia, for whom conventional assays failed to identify the genotype. Phylogenetic analysis of the sequences of the core, envelope 1 and part of the non- structural 5b regions suggests that all three isolates belong to a distinct HCV genetic group, tentatively classified as subtype 3h. This novel HCV subtype shows the highest sequence similarity with HCV isolates from Indonesia. Despite the fact that these patients were infected with HCV clade 3, none of them responded to standard interferon treatment