Journal of Engineering and Technological Sciences
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Synthesis of Structured Triglycerides Based on Canarium Oil for Food Application
Get PDFThis paper concerns the synthesis of structured triglycerides containing different proportions and positions from medium- (M) and long-chain (L) fatty acids on a glycerol backbone. Structured triglycerides of MLM type were synthesized by utilizing canarium oil and incorporating caprylic acid (C8:0) as a source for the medium chain (M) fatty acids. Synthesis was performed through a two-step enzymatic reaction, with ethanolysis as the first step and esterification as the second step. Both reactions use the sn-1,3 specific lipase as a catalyst, which has specific activity at positions sn-1 and sn-3 of the triglyceride structure. The results from high-performance liquid chromatography showed that the stereospecific distribution of fatty acids in the structured triglyceride was 29.52±0.59 and 44.28±0.88 mol% of caprylic acid in the positions of sn-1,2,3 and sn-1,3, respectively. Furthermore, analysis of the physicochemical properties of both the native canarium oil and the structured triglycerides using an independent-sample t-test at p < 0.05 indicated that the two samples were significantly different for saponification number, iodium number, and average molecular weight. The results of this study showed that canarium oil can be exploited as a starting material for functional food application
Axial and Lateral Small Strain Measurement of Soils in Compression Test using Local Deformation Transducer
Get PDFThis paper presents the development of a method using local deformation transducers (LDTs) to locally and sensitively measure small axial and lateral strains in soil in a compression test. A local strain measurement system comprising of axial and lateral LDTs was developed referring to the original LDT system and the cantilever LDT system, respectively. The LDTs were calibrated both in air and under water. Their insensitivity to pressurized water was confirmed. The calibration factors for the axial and lateral LDTs were found to be 1.695 mm/volt and 1.001 mm/volt, respectively. The performance in terms of repeatability and stability of the LDT system was evaluated. The repeatability test showed that the average standard deviation of the lateral LDT was 0.015 volt, while the stability test showed that the average standard error of the axial and lateral LDT were 3.13 × 10-5 volt and 2.65 × 10-5 volt, respectively. Unconfined compression tests were conducted on three reconstituted clay samples to examine the proposed axial and lateral LDT system. The stress-strain relationship indicates a nonlinear relationship between the axial and lateral strain of soil instead of the conventionally assumed constant relationship. The results demonstrate this nonlinear behavior even at small strain levels, which were successfully measured using a domestically built axial and lateral LDT system
Vibration Parameter Optimization of a Linear Vibrating Banana Screen Using DEM 3D Simulation
Get PDFIn this paper, the effects of vibration parameters of a banana screen, i.e. frequency, amplitude and vibration direction angle, on the screening efficiency per unit time were studied using the discrete element method (DEM). The simulations were validated according to data collected from an experimental prototype screen. Functional relationships between vibration parameters and screening efficiency per unit time are presented. The results showed that the screening efficiency per unit time first displays an increase and later a decrease when the frequency, amplitude or vibration direction angle increased respectively. Vibration parameter optimization was also investigated, using an orthogonal experiment. Based on the banana screen model, it can be concluded that when the frequency is 22 Hz, the amplitude is 2.2 mm and the vibration direction angle is 39°, the screening efficiency of a banana screen is optimal
Analysis of Protein Separation Mechanism in Charged Ultrafiltration Membrane
Get PDFThe separation mechanism of proteins on a charged ultrafiltration membrane was analyzed using the extended Nernst"“Planck (N-P) model. The model was solved numerically based on experimental data during ultrafiltration of bovine serum albumin/BSA and hemoglobin at various pH (between 5 and 8) to obtain the flux parameter (Jv). The flux parameter was used to determine the effective charge of the membrane (f) and the actual membrane porosity (Ak). These two parameters were then used to predict the transport mechanism of proteins through the charged membrane. Higher flux was obtained during the ultrafiltration of BSA compared to hemoglobin. The most effective separation of mixed proteins occurred at pH 5 (aalbumin= 5). In addition, the mobility of a single protein was lower than when it was mixed with other proteins that had different charges. The effective charges of the membranes were varied between 0.99996 to 1.0000, which means that the fixed charge on the membrane structure was higher than the concentration of proteins, thus the effective charge of the membrane was not influenced by the presence of protein charge at various pH. On the contrary, the value of Ak was influenced by the type and charge of the proteins. A decrease of negative charge along with an increase of solution pH increased the porosity of the membrane, thus reducing the rejection of proteins
Prediction of Service Life Decline of Double Welded Wide Flanges due to Fatigue in Steel Arch Bridge under Excessive Loads
Get PDFThe purpose of this study was to investigate the characteristics of the rate of fatigue fracture propagation in members under maximum force on a steel arch bridge and to identify the fatigue life of those members under excessive loads. The method for bridge fatigue prediction used was numerical S-N curve controlled by cumulative damage rule, fracture critical member, and fatigue fracture determination based on SNI 1729-2015, S-N category. The distribution of stress, strain and life cycle was obtained. The result revealed 1 critical built-up weld beam on the steel arch bridge, specifically double welded wide flange beam TB7. Excessive loads from heavy vehicles, namely trailer types 7C1, 7C2 and 7C3, were simulated. Initial fracturing would occur after 53 years and 5 months of service with an initial crack size of 1.717 mm, leading to a propagation cycle of 45 years, which would cause critical fractures of 10.55 mm after 99 years. Thus, the maximum number of vehicles permitted to enter the bridge, assuming a 5% increase per year, was 13,450 per year for trailer type 7C3 at a planned capacity of 6,984,000 vehicles. This paper illustrates how fatigue life prediction can be a useful guide for the sustainability of bridges and provide a theoretical basis for developing optimized fatigue life of steel arch bridges
Healthcare Data Mining: Predicting Hospital Length of Stay of Dengue Patients
Get PDFDengue is regarded as the most important mosquito-borne viral disease. Recently dengue has emerged as a public health burden in Southeast Asia and other tropical countries. At times when dengue re-emerges as an epidemic, hospitals are required to be able to handle patient flow fluctuation while maintaining their performance. This research applied a data mining technique to build a model that can predict in-patient hospital length of stay from the time of admission, which can be useful for effective decision-making that may lead to better clinical and resource management in hospitals. Using the C4.5 algorithm and a decision tree classifier, an accuracy of 71.57% and an area under the receiver operating characteristic (ROC) curve value of 0.761 were obtained. The decision tree showed that only 7 out of 21 input attributes affect the hospital length of stay prediction of dengue patients. The attribute with the highest impact was monocytes, followed by diastolic blood pressure, hematocrit, leucocytes, systolic blood pressure, comorbidity score, and lymphocytes. In this research also a prototype of a prediction system using the resulting model was developed
