Papers by Keyword: Temperature

Abstract: Hardened AISI 1045 steel implemented in machine tool spindle was previously ground using grinding operation. This research aims to address the feasibility of hard turning AISI 1045 using PCBN tool with chip breaker under dry condition. Chip morphology, cutting force and temperature were measured, analyzed and correlated with machining parameters. Experimental results demonstrate that serrated chips are generated at high speeds, high feed rate is an assistant to promote serrated chips, and chip breaker can help break chip into acceptable lengths. Cutting forces were characterized with periodic fluctuation along three directions as chips are serrated. Temperature at machined zone can reach as high as 1200^°C, which indicates that adiabatic shear bands can be successfully achieved during the machining of hardened AISI 1045 steel without applying lubricants.

Abstract: Iron ores should be separated from oxygen and impurities which are coming along during the mining process. The separation process is known as reduction. There are two types of reduction process, and the most common is direct reduction process (DRP). There are several parameters in DRP which will determine the quantities of the product known as direct reduction iron (DRI). This worked discussed the effect of reduction temperature and pellet heap to the quantities of DRI using single conveyer belt Hearth furnace. The worked was done in laboratory scale using composite pellets with 14 mm in diameter. The ratio of iron ore to coal in the composite pellet is 1 to 1. The reduction process temperatures are 500^oC, 700^oC and 900^oC. The reduction time is 25 minutes. While the pellets heap are also varied to 1, 3, 5, 7, 8 and 9 layers. The results show that DRI was formed in 700^OC and the quantities of DRI are in line with the reduction temperatures and layers of composite pellets heap.

Abstract: Microcontroller Arduino Mega and ATmega is a computer chip that needed and developed to control system or process. Microcontroller Arduino Mega and ATmega can be used to temperature control systems [1][2][3], the room lighting control, security control, the hazard warning [4], scheduling, monitoring water flow and dams actuator door and etc. Most studies on the microcontroller is focused on the functional capability of a microcontroller to read or measure the object. In addition to aspects of good function, microcontroller must have a high sensitivity in order to avoid delay or in-accuracies in the sensor reading measured object such as temperature. Microcontrollers has some advantages and disadvantages of the process accuracy depends on the processor and the ability microcontroller. In this paper focuses on the measurement errors that occur on microcontroller Arduino Mega and ATmega 8535 with a temperature sensor LM 35 and hygrometer digitizes dt05 for the application process cooling and heating sea water controls. The volume of sea water is measured is 3 to 35 litters with a temperature set point 28°C of lower temperatures above 25°C and 31°C. The results show that the maximum error obtained by using microcontroller Arduino Mega is 1,32°C or 13,2 mV and ATmega 8535 is 0,2°C or 2 mV. Also the microcontroller Arduino Mega is more suitable for control temperature measurement in the process of heating and cooling sea water.

Abstract: Titanium alloy is finding increased application in aeronautical, automobile and structural applications. During post processing of titanium alloy, milling is one of the mostly used machining processes. In this study, the relationship between temperature and milling parameters was developed by response surface methodology (RSM), and a temperature model for milling titanium alloy is proposed. The model is found to be adequate through ANOVA. The result indicates that the increase in cutting speed and feed rate increases the temperature. The radial depth of cut and depth of cut do not show a general trend on temperature in milling of titanium alloy.

Abstract: The protection against lightning had been increasingly used in the building to protect the building from the direct lightning impact. One of the methods is to embed the lightning protection cable in the concrete structure. The objective of this research is to investigate any changes of temperature during the lightning strike, which the lightning strike were stimulated by high electric current equipment. The high electric current were provided by high current equipment model Haefely P90.1 and flowed into the concrete cube. There are two method used in this research, by using Thermal Imager Camera Model FLUKE Ti20 to monitor the surface temperature and fiber thermocouple with Data logger model DATATAKER T80 to monitor the temperature in the concrete cube. As the result there are no drastically changes in temperature in both methods. The changes are very small and can be negliable. This is due to the duration of the high electric current strike is too short and not caused any changes in the temperature.

Abstract: In the paper, the influence of friction on temperature distribution in the friction spot stir welding process of titanium grade 2 is analysed. It is assumed that the friction coefficient may be a function of temperature or the relative speed of the contact areas. The finite element method is used in the numerical calculations. Temperature distributions and temperature versus time for the analysed friction coefficients are presented. The results also show that applying a proper frictional model is very essential for the sake of heat generation during friction stir welding.

Abstract: In the present work, a finite element modeling of hot turning has been carried out for predicting computationally the state variables like temperature distribution on chip surface and cutting forces in hot machining of Inconel 718. The hot turning operation has been carried out with L₉ orthogonal design of experiment (DOE) with varying cutting speed, feed rate, heating temperature and constant depth of cut to analyze the responses. The model predicts the temperature distribution, cutting forces with and without heating. DEFORM 2D is applied for modeling hot turning simulation as similar as possible to the experimental result. Flow stress and input parameters should be modeled according to the actual machining conditions. The predicting results i.e. cutting forces and temperature distribution were partially validated with the experimental data.

Abstract: Gasification is one of the technologies for utilization of biomass. Gasification is a transformation process that converts solid fuels into gaseous fuels. The gaseous fuel may be subsequently applied in other technologies with all the benefits that gaseous fuels provide. The principle of biomass gasification is a common knowledge. It is thermochemical decomposition oof the fuel in presence of gasification agent. Heat from the endothermic reaction is obtained by a partial combustion of the fuel (autothermal gasification) or the heat is supplied into a gasifier from the outside (allothermal gasification). Oxygen for the partial combustion is supplied in the gasification medium. Quality, composition and amount of the producer gas depend on many factors which include type of the gasifier, operating temperature and pressure, fuel properties (moisture content) and type and amount of gasification medium. Commonly, air, steam and oxygen and their combinations are used as a gasification medium. Every kind of gasification agents has its significant advantages and disadvantages.Research and analysis of the gasification process must pay special attention to all operating parameters which affect quality and amount of the producer gas that is the efficiency of the conversion itself. Composition of the producer gas, calorific value, and content and composition of impurities are especially observed as these are the basic characteristics directly affecting subsequent application of the gas. Steam addition has a significant impact on gas composition. Steam decomposition into hydrogen and oxygen, and their subsequent reactions increases amount of combustibles, hydrogen, methane and other hydrocarbons. Steam addition in the gasification also affects amount and composition of tar and has a negative impact on heat balance.Energy Institute at the Brno University of Technology has a long tradition in research of biomass gasification in atmospheric fluidized bed reactors. Air was used as a gasification medium. This paper describes our experience with gasification using a mixture of air and steam. We analysed the whole process and in this paper we wish to describe the impact of temperature on outputs of the process, especially temperature of leaving steam and temperature of gasification reactions.

Abstract: Temperature and pressure are very important factors that influence corrosion process. We often need to choose a proper vessel in the corrosion test that need to control both temperature and pressure. Moreover, the material of the test vessel should not be harmful to corrosion liquid. For example, steel even stainless steel will be corroded in warm seawater, and they are not suitable for the vessel material. We designed a corrosion test vessel made of Poly-Propylene Random (PPR), and temperature can be controlled within room temperature and 100Celsius degree, pressure can be controlled within1to10atm.(1MPa). In this paper, temperature-controlled method and pressure-controlled method are described. Temperature and pressure characteristics are also analyzed and described. Shell structure, material and design are introduced. A series of typical corrosion tests were performed by using this corrosion test vessel.

Abstract: This work studied on the kinetics of Vitamin C extraction from banana peel at different solvent/solid concentration and temperature. Musa Acuminata was ground into smaller sizes before contacted with methanol as a solvent in an ultrasonic bath. To study the effect of solvent/solid ratio, 4.5, 5.0 and 10.0 ml/g ratio were used for the extraction at fixed temperature. Then, the temperature was varied with the heating element available in the ultrasonic bath at 30, 45 and 60 °C, to study the effect of temperature on the extraction kinetics. It was found that high solvent/solid ratio (10 ml/g) provides more solute-solvent contact and prevents the extracted Vitamin C from coming into contact with the air. Besides, higher temperature (60 °C) contributes sufficient kinetic energy for Vitamin C distribution in the solvent which is important to prevent degradation with air. The best fitted kinetic model for Vitamin C extraction from Musa Acuminata is Ana et al. (2007) with equilibrium concentration of 0.05 g/L and 0.40 g/L.hr extraction rate.