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NuScale is an integral pressurized water reactor (PWR) that applies natural circulation mechanism in its safety system. During a loss of coolant accident (LOCA), its emergency core cooling system (ECCS) uses the containment wall to cool the reactor core by opening valves. If the ECCS fails to function, one alternative to prevent the core damage is by utilizing the steam generator (SG) to remove heat from the primary system. In this study, a simulation is carried out to investigate whether the SG design has sufficient capacity for such cooling. The simulation is performed using the RELAP5 code by modeling the reactor system, safety system, and control system at the input. The model is validated using steady-state and transient calculation data from the NuScale design certification application (DCA) document and independent analyst publication. The scenario was a pipe break at the chemical and volume control system (CVCS) injection line, followed by failure of the ECCS. Activation of the SG feed water is carried out 10 minutes after the ECCS failure is recognized. The simulation result shows that the SG cooling is capable of bringing the pressure and temperature in the primary system down and maintain a stable water level at a position above the top active fuel. However, due to the limitation ofRELAP5 in modeling the helical SG, this simulation result needs further verification, especially in condensation cooling. [ABSTRACT FROM AUTHOR]

One of the causes of drought crises in Indonesia was the mixing of water in the residents' dug wells with seawater — brackish water — whose salinity is high and not following drinking water standards. The lack of clean water usually occurs during the long-dry season, is advantageous because of the abundant source of solar radiation. Therefore, the brackish water desalination process can be done utilizing solar energy. Carocell 3000 solar-still has been widely used to produce purified water because of its low price and ease of use. According to the manufacturer, this solar-still can provide purified water from 65% of the solar energy it receives. Nevertheless, the information on the optimum input flow rate is missing. This study aims to determine the optimum input flowrate of Carocell 3000 solar-still to produce the maximum volume of purified water. The experiment was conducted in July by varying the amount of input flowrate ranging from 48, 72, 92, to 120 ml/min then measuring the volume of purified water produced within an hour. The limitation of only one solar-still available made the testing of parameter variations cannot be done simultaneously at the same time on the same weather conditions, so data for the analysis were collected from several days of testing. Data with the almost equal value of solar radiation were selected to see the performance of solar-still in producing the maximum volume of purified water with different variations of input flow rate. The result showed that input flowrate affects the production of purified water, but not linearly. With the average solar radiation of 461±24 W/m2, the input flow rate of 48 ml/min was the optimum input flow rate for Carocell 3000, which has an evaporator surface area of 3m2, because of its higher efficiency of purified water produced within an hour, around 34%. [ABSTRACT FROM AUTHOR]

Heart disease is the number 1 cause of yearly deaths, that stays true even in the middle of the COVID-19 pandemic. COVID patients who already had early heart diseases have a higher mortality rate. From recent founding, it is known that COVID also kills made blood clots in heart coroner like fat clotting from Myocardial Ischemia. ECG (Electrocardiograph) is not just a device used to monitor heart disease, but the heart's entire activity. Meaning it could detect blood clots inside a COVID patient's heart. The question is: "Are there enough ECGs for every patient?" Accounting that the big hospitals in Indonesia have ECG but with much smaller health care centers like Puskesmas left without one. Blue ECG is an ECG device designed to be portable and useful with low-cost production. With its Bluetooth function accompanied by a Smartphone app, it could be used to diagnose patients from long distances. [ABSTRACT FROM AUTHOR]

The major cause of COVID-19 patients' death is the infection area in which it has already infected lungs and is worsened by comorbidity. Diagnostic equipment named Patient Monitor's availability also does not prevail equally as it has a very high price. This research aims to conduct the early detection mechanism of COVID-19 symptoms, so thus can enable a method to sort out which patients need to be through further medical examination and which needn't. We do initially opt for the components, i.e. MAX30100 sensor module and HC-05 Bluetooth Module. The latter is to examine the patient with the Mini Patient Health Monitor device. The outcome is a provision to perform COVID-19 Pretest examination with Mini Patient Health Monitor in Affordable Cost in order to determine whether further medical examination is necessary. COVID-19 Pretest's examination result appeared in the application screen could be sent to patients who need it. COVID-19 Pretest's examination with Mini Patient Health Monitor in Affordable Cost can actually be integrated in a framework to prevent COVID-19's infection (namely transmission) and spread as well. [ABSTRACT FROM AUTHOR]

Plastic waste is one of the biggest environmental problems worldwide, including in Indonesia. A community based initiative such as the waste bank is seen by many as a potential player contributing toward the alleviation of the problem. However, their sustainability in operation is very dependent on the plastic selling price which constantly fluctuates. The conversion of plastic waste, such as polyethylene terephthalate (PET) into a higher value product by the use of a shredder and an extruder can help this matter. An extruder is a machine which can produce plastic filaments by applying a heat to the inputted shredded plastic wastes. In this work, a simple, low-cost extruder designed to be suitable to the condition of the developing nations is developed. A simple control system is applied to the system for a better temperature output. The produced filament is evaluated for consistency of density and diameter under varied temperature. The optimum temperature found is 200oC and the produced filament is observed to be within a reasonable degree of consistency in terms of diameter with an error in the range of 20%. [ABSTRACT FROM AUTHOR]

World Health Organization (WHO) data stated that heart diseases cause 37% of deaths in Indonesia. In Indonesia, devices used to monitor the heart’s activity or electrocardiogram (ECG) are only owned by some big hospitals. With an Arduino microprocessor, a simple portable ECG with a function to read the heart’s condition could be made. The AD8232 sensor is the main device that is used to read the heartbeat by processing the voltage received from the electrodes attached to the body. Combination of Arduino-Uno and HC-05 FC-114 as a Bluetooth antenna, an ECG display could be seen on a smartphone’s monitor in real-time. An ECG simulator is used as an artificial heart activity to be used as a trial for the ECG portable’s performance from test results. ECG using the simulator can be delivered to the smartphone’s monitor by Bluetooth module with an accurate result that draws the real-time condition of the patients. [ABSTRACT FROM AUTHOR]

Environmental damage is becoming an important issue in climate change discussion in the world. The use of natural refrigerant at this time be an alternative choice as a substitute for refrigerant that damage the environment, both the impact of global warming potential and ozone depletion potential. The aim of this research is to develop the correlation of single phase heat transfer as part of contribution of the two-phase heat transfer. The research method used evaporation process in pipe 0.5 mm diameter and length of 0.5 meter. From a single phase heat transfer research data was developed a new correlation for single phase heat transfer on a microchannel based on heat transfer from Dittus-Boelter [1]. The new correlation of single phase heat transfer is 7.608 x 10-7 Re1.913 Pr0.4. Comparison of single phase heat transfer research data with new single phase heat transfer has MRD minus 2.87% and MAD = 30%. The comparison of single phase heat transfer of the research with existing correlation was obtained by the lowest MRD of Wang & Peng [2] with minus 7% and the highest MRD from Dittus-Boelther [1] with minus 70%. [ABSTRACT FROM AUTHOR]