Search

The radiation dose of X-ray radiation exposure that comes from a CT scan is not easy to determine, because a CT scan uses several beams of X-ray radiation for one scan. In addition, the X-ray exposure dose on the CT scan is not the sum of the X-ray radiation exposure doses from each beam. Therefore, the Size-SpecificDoseEstimate (SSDE) parameter is used, which means as the estimated radiation exposure dose received by the patient. The SSDE value is a function of the CTDIvol which is determined from the reference phantom or from the derived Dose Length Product (DLP) values. The CTDIvol value determined from the reference phantom has the same value for the weight interval of the patient, so that the patient gets the same dose of X-ray exposure even though the body size is different. The CTDIvol value determined by Dose Length Product (DLP) depends on the lateral length of the patient’s body. Because the lateral body length of each patient is different, the CTDIvol value will be different, so the SSDE value will vary more. The results showed different SSDE values for each patient according to body mass index.

Dust has a size of 0.001 - 10000 µm. Dust from motor vehicle exhaust emissions generally has a size of 1 - 150 µm, and flying dust due to vehicle traffic has a size of 100 µm. This dust when it falls on the leaves will cover the stomata. The length of stomata is 80 µm and a maximum width of 50 µm, which is smaller than the size of the dust. As a result, the stomata will be covered by dust, and the leaves cannot absorb CO2, an important ingredient in photosynthesis. The leaf samples used in this study were Polyalthea Longifolia leaves located near the highway, around the cement factory, and in plantations as a control. Then, the leaves were measured for the content of total chlorophyll using the Wintermans and de Mots equation, and mineral content using X-ray Fluorencence (XRF). The results showed that the leaves around the cement factory had a yellow color, small, lower chlorophyll content, and had low absorptivity on minerals than the leaves from near the highway and control.

The purpose of this study is to mitigate risks in supply chain activities in the production of cotton shirts. The method used in this research is the House of Risk (HOR) approach based on the Supply Chain Operation Reference (SCOR) model. The House of Risk (HOR) offers a framework for effectively controlling risks in managing risks from risk agents. Aggregate Potential Risk (ARP) is used to determine the priority of risk sources that need to do in the design of mitigation strategies. The research results identify as many as 26 Risk Events and 21 Risk Agents. Three Risk Agents based on ARP values are Procedures for Delivery of Less Organized Raw Materials, limited and Sudden Product Demand from consumers Mitigation actions used to prevent the causes of risk from occurring are creating standard operating procedures for raw material delivery activities. Also, a contract system establishes between suppliers of raw materials and freight forwarding services. Migration in human resources is evaluating employee performance. Empowerment of the community around the company, subcontracting to other similar companies, reviewing raw material stock is an act of meditation in sudden product demand.

Lung cancer is disease that can cause death in a short time, but it is almost never detected at an early stage, because its symptons are not specific, such as coughing and lack of appetite. In some patients who have a smoking habit, it is easier to be suspected of having a tumor or lung cancer. In order to detect a tumor or lung cancer, a chest X-ray examination is generally done as an early diagnosis. As we have already known, exposure of X-ray radiation to the body can have a negative impact, therefore the dose of X-ray radiation exposure must be minimized. In this study a measurement of entrance skin dose (ESD) was performed on chest X-ray examination in patients suspected of having a tumor or lung cancer. The results showed that patients who had symptoms similar to those of tumor or lung cancer had higher ESD than those who did not. Although the radiation dose is higher than dose on routine chest X-ray examination, it only shows abnormality of radiological photogaraph but do not accurately indicate the presence of tumor or cancer.

National sugar production only reached 2.756 million tons in 2014. This number has not been able to meet total consumption of 5.396 million tons. The steam boiler stack generated from coal combustion process in sugar production produces sulfur dioxide gas waste. This research purpose was used as simulation tool to determine the concentration of emissions produced at distance, time, the dispersion of emissions direction, and the type of distribution patterns. The research method was the American Meteorological Society - Environmental Protection Agency Regulations Model (AERMOD). The data input of the AERMOD model consisted of meteorology data, stack emissions, and topography for past 5 years. Meteorological data processed by AERMET was taken from the Hasanuddin station (ID WMO 971800 / WAAA). The topographic data was obtained from the AERMAP model which was downloaded and processed using SRTM3 coordinate data. The result of the AERMOD model was the isopleth map which showed the dispersion pattern of pollutants with different concentrations. The SO2 concentration value of 6.91348 μg/m3 was the highest value that occurred at 1 hour measurement since the pollutant was emitted from the stack located 293 meters from the emission source (UTM 774635.04 m and 9435968.83 m).

X-ray is ionic radiation which is now a necessity in the health sector as a tool in establishing diagnosis. Calculation of exposure doses in patients generally only considers gender and age, but from a theoretical point of view, energy absorption will be greater with increasing thickness of material. The thickness of the material in terms of chest examination using X-rays is indicated by position of the examination where the lateral examination makes the material exposed to radiation thicker than the posterioranterior or anteriorposterior examination position, as well as the patient's body mass index. Therefore, the relationship between the position of examination and body mass index to the entrance surface dose is the topic of this study. Analysis of chest examination data in several patients with various examination positions and different body mass indices showed an increase in entrance surface dose with increasing body mass index and examination position. The highest entrance surface dose was observed in patients with lateral examination positions, as well as in patients with large body mass indexes.

The diffusion-convection equation with variable coefficients and for anisotropic media which were previously considered by other authors are discussed again in this paper to find their numerical solutions by using the boundary element method (BEM). The numerical results obtained show the consistency and accuracy of the BEM solutions. Also, the solutions exhibit the impact of the anisotropy and inhomogeneity (spatial variability) of the media.

This study aims to determine the value of the typical dose rate, the maximum dose rate in the air and the dose rate on the surface of Image Intensifier (II) in 3 types of dual function Fluoroscopy (FL). This study used a dual function Fluoroscopy, X-Ray safe multimeter, Pb plate, Cu plate, and phantom perspek. Typical dose rate measurement were carried out by placing a multimeter X-Ray of phanrom perspek of a thickness of 18 cm, so that the examination table distance from the detector was 18 cm and source distance from image of 96 cm according to normal patient position. Measuring the maximum dose rate in teh air is done by placing the detector at distance of 300 mm above the examination table, placing the Pb 2 mm below the collimator, the exposure is carried out at the maximum automatic kVp. Measuring the dose rate of the surface Image Intensifier (II) is done by placing the detector above II, the Cu plate with a thickness of 2 mmCu is affixed to the surface of the collimator and the exposure is carried out on the automatic kVp. Typical dose rated to test results from FL (A) and FL (C) with the same size II are 35 cm while FL (B) sized II is 23 cm. The results of the tipical dose rate test for FL (A), FL (B), and FL (C) are 11.428 mGy/minute, 11.712 mGy/minute and 12.518 mGy/minute, respectively. All results of the testing of the typical ESD dose rate are still within the test passes which are ⩽17 mGy/minute as required by BAPETAN Regulation No. 2 in 2018. The value of the maximum dose rate in air of each planes is very varied from the maximum value on FL (B) is 11.402 mGy/minutes, while the minimum value occur to FL (C) is 4.311 mGy/minutes. As for FL (A), the maximum dose rate in air is 7.998 mGy/minutes. All results of testing the maximum dose rate in air are still below the test pass value required by BAPETAN which is 50 mGy/minutes. The value of the dose rate of surface II varies greatly from FL (B) having a maximum value is 68.2 µGy/m inutes while FL (A) and FL (C) are 33.3 µGy/minutes and 2.4 µGy/minutes, resvectively. All results of testing the dose rate of the surface of Image Intensifier (II) are still below the test pass value required by BAPETAN which is 60 µGy/minute for size II 23 cm and 90 µGy/minute for size II ⩾ 23 cm.