The purpose of this study was to ascertain the impact of repeated heating of coconut oil on the value of viscosity, density (mass density), surface tension, and the coefficient of temperature reduction rate (Newton cooling constant). The coconut oil sample used was the result of my own production. The heating repetition was carried out at most five times with a peak temperature of 90oC. The physics quantities were respectively determined by the methods of the falling ball, the directly measuring the mass and volume with the measuring cylinder, the raising fluid in a capillary tube, and the Newton cooling.From this study, it was found that there was an effect of repeated heating of coconut oil on the value of viscosity, mass density, surface tension, and the Newton cooling constant. This effect is indicated by the presence of a functional relationship between the heating test and the value of the four physical quantities. The relationship between heating repetition and viscosity is a quadratic function, the relationship between heating repetition and mass density is a linear function, the relationship between heating repetition and surface tension is a quadratic function, and the relationship between heating repetition and Newton cooling constant is a quartic function. The four functional relationships are empirical equations that state the laws of nature in a certain heating range and can be used as material for further studies to reveal the physical mechanisms that build them, including determining the general equations that unite them.

Whole body vibration is vibration that propagates throughout the worker's body from vibration sources in the form of machines, vehicles, and so on. In this paper it is reported the results of research to determine the total value of vibration acceleration on several drivers of the public transport in Samarinda and to analyze the comfort level of the drivers receiving the vibration on their bodies. The components of the vibration acceleration were measured by using a vibration meter type of Svantex 106. The comfort level of the driver in receiving the vibration was assosiated with the scale of comfortable level set by the Ministry of Manpower of the Republic of Indonesia by decree number PER.13/MEN/X/2011. The research found that the average of the total value of vibration acceleration received by the drivers in A, B, and C transportations were 0.3877 m/s2 , 0.7056 m/s2 dan 0.6596 m/s2 , respectively. In Samarinda the drivers in B and C transportations were more uncomfortable to receive the whole body vibration than the drivers in C transportation.

Environmental pollution is one of the major problems opened by the world today. The main problem of this pollution, is decreasing air quality. This decrease in air quality is caused by many things, from excessive environmental exploitations, industrial activity, energy use, until the exhaust emissions of vehicles all of which trigger into pollution problems. So far Indonesian government has purchased and use the Air Quality Monitoring Base Station to measure different types of air pollutants. However, field statistics data show that the minimum quality of air quality measuring devices in each city is not commensurate with the minimum recommended amount, ideally one base station is used for 200.000 inhabitans. In this research, we developed an integrated Wireless Sensor Network to monitor the concentration of air pollution. Implemented fifteen sensor nodes which each node contains CO and NO2 sensors to sensing from the environment. the collected data will be used to calculate the standard air pollution index of samarinda city. The data is stored in server and we can publish for public to access information throught a gadget and thing speak server.

No abstract

Noise is a sound that humans do not want and it is an environmental factor that can negatively affect health. To overcome the noise issue, many efforts have been made to reduce noise levels. An example is the manufacture of the walls of a house using materials with sound and absorbent standards. The materials used can also be derived from types of wood such as plywood, wood panels and calciboards. Therefore, the value of its sound absorption coefficient is calculated to find out which active material is to be used in the manufacture of the building. Based on the research results, the value of the sound absorption coefficient of the three types of materials, it can be seen that the shape of the graph and its analysis states that the lowest sound absorption coefficient is most likely at the lower frequencies and the highest value of the sound absorption coefficient tends to be at the higher frequencies. In fact, when viewed as a whole, the magnitude and magnitude of the sound absorption coefficient on the graph is not in line with the increase in the frequency value.