Avita Ayu Permanasari

Pulsed Electric Field Assisted Extraction of Cellulose From Mendong Fiber (Fimbristylis globulosa) and its Characterization

ABSTRACT In the present work, the properties of cellulose extracted from mendong fiber have been investigated. The experiments were conducted by two different methods to extract the cellulose from mendong fiber, which is extracted by alkali and alkali assisted by PEF. The cellulose was analyzed using X-ray diffraction, Fourier Transform Infra Red, Thermogravimetric Analysis, and compared with cellulose of commercial product. The morphology of cellulose after extraction was observed using both optical and Scanning Electron Microscope. The crystalline structure properties of cellulose extracted from mendong fiber assisted by pulsed electric field (PEF) were similar to the commercial cellulose.

Optimization of multistage artificial agingparameters on Al-Cu alloy mechanicalproperties

Purpose: This research is aimed to describe heat treatment process by using multistage artificial aging for Al-Cu alloy with Taguchi method in Minitab 16 to optimize the heat treatment parameters. This research conducted due to the applied of aluminium alloy in automotive industrial and aircraft industrial that has good properties for fabrication. Design/methodology/approach: Methodology that use in this paper is experimental design with statistical approach. Three controllable parameters were selected, they were temperature aging, holding time of aging, and the number of stages. The hardness value and impact value after multistage artificial aging were chosen as quality characteristics. The experiment was performed using orthogonal arrays of L9 (33). Findings: The finding that resulted in this research are the most significant parameters that affected hardness and toughness value of Al-Cu alloy against multistage artificial aging. The optimal hardness and toughness for Al-Cu alloy were obtained with heat treatment at temperature 200oC, holding time for 6 hours, with two stages artificial aging. Research limitations/implications: The limitation that found in this research is even optimal level had been determined, it is unable to determine the true optimal value of each design parameters. Practical implications: This optimization process can be applied in manufacture process in industrial without spend expensive cost and time. Originality/value: According to research result, can be understood that by conducting these experiments, the impact value and the hardness value of Al-Cu alloy increase with multistage artificial aging treatment.

The research-based learning development model as a foundation in generating research ideas

Research Based Learning is learning that requires students to have exploration skills related to their field. By doing so, students are encouraged to create skills in managing the higherorder of abstraction in order to resolve any problems encountered. The study was done to make the schemes and sequences of learning needed by the students in order to help them to explore first ideas for their upcoming thesis. The scheme development resulted in five stages consisting of 1) identifying research journals; 2) track the development of research topics; 3) reviewing research journals; 4) discussing the results of the reviews; and 5) formulating the research topic. Furthermore, the application of 5 the stage receives percentage agreement of students was 85.9%. Therefore, it can be noted that the application of the scheme is definitely a help for students to find research ideas.Research Based Learning is learning that requires students to have exploration skills related to their field. By doing so, students are encouraged to create skills in managing the higherorder of abstraction in order to resolve any problems encountered. The study was done to make the schemes and sequences of learning needed by the students in order to help them to explore first ideas for their upcoming thesis. The scheme development resulted in five stages consisting of 1) identifying research journals; 2) track the development of research topics; 3) reviewing research journals; 4) discussing the results of the reviews; and 5) formulating the research topic. Furthermore, the application of 5 the stage receives percentage agreement of students was 85.9%. Therefore, it can be noted that the application of the scheme is definitely a help for students to find research ideas.

Online monitoring cutting tool wear using audio signal

This study of an experimental study on-line monitoring of audio signals with a microphone during the process of turning mild steel at the time of cutting tool wear before and after wear with the ultimate goal of production cost reduction and product quality improvement. Much of the research conducted to develop a tool condition monitoring system. However, the development difficult to apply. One problem is the price of the sensor is quite expensive, so the only major industry that may apply. Therefore, we need an alternative sensor affordable yet accurate and powerful for detecting wear of the cutting tool. The signal is processed using commercial software such as Lab View time domain and frequency domain. Signal received by the Lab View is filtered so that the value that appears is not the signal from the noise in addition to the signal cuts. Of these cuts can be known signal frequency and amplitude values that appear when the cutting tool is worn. As a result of research, the signal can be used to detect...