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Journal : Journal of Vocational Studies on Applied Research

Mechanical Properties of Commercial Recycled Polypropylene from Plastic Waste Handayani, Sri Utami; Fahrudin, Muhamad; Mangestiyono, Wiji; Hadi Muhamad, Alaya Fadlu
Journal of Vocational Studies on Applied Research Volume 3, Issue 1, Year 2021 (April 2021)
Publisher : Vocational College of Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (331.225 KB) | DOI: 10.14710/jvsar.v3i1.10868

Abstract

In Indonesia increasing the use of plastic will increase plastic waste because waste management in Indonesia is still poor. Plastics can be recycled and used to make plastic bags, toys and various household utensils, but their use is still very limited. This limitation is because the strength of recycled plastic is not as good as virgin plastic pellets, so the resulting product tends to be brittle. This study aims to determine the mechanical properties of plastics made from recycled polypropylene plastic. Five specimens are made according to the ASTM D 638 type II standard. The results show that yield strength is 16.357±2.65 MPa, elastic modulus 295,926 ± 41,97 MPa and ultimate tensile stress 19,701±1,261 MPa. The yield stress of recycled polypropylene has a lower value than the yield stress on recycled polypropylene studied by Abdelhaleem et.al or Barbosa et.al which is around 21 MPa[7][5]. This difference is possible due to the different quality of raw materials and processing.
Feasibility Study and Heat Transfer Analysis of Testbed Shell and Tube Heat Exchanger at Tube Side Fluid Discharge of 5 Lpm and Hot Fluid Temperature of 60 C Firmansyah, Devian Arif; Handayani, Sri Utami
Journal of Vocational Studies on Applied Research Volume 5, Issue 2, Year 2023 (October 2023)
Publisher : Vocational College of Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jvsar.v5i2.19173

Abstract

A fluid's phase or temperature can be changed by a heat exchanger. To improve students' understanding of heat exchangers, the existence of a heat exchanger is essential. In the Energy Conversion Laboratory, a test bed for a shell and tube type heat exchanger with a 1pass shell - 2pass tubes was created to conduct this study. The performance of the heat exchanger was then evaluated, along with its efficiency and heat transfer coefficient. Heat transfer calculations and the effectiveness of shell and tube heat exchangers were used in this study's experimental methodology, which involved designing and building a test bed heat exchanger. The heat exchanger has 1.5 m of tube length, 19.05 mm of tube diameter, 25.4 mm of tube pitch, and a 10-inch shell diameter. Iron serves as the shell material, while 304 stainless steel serves as the tube material. The heat exchanger performance has a heat transfer coefficient of 133,868 W/m2oC and a heat exchanger actual effectiveness of 58.84%. The theoretical heat transfer coefficient (Utheoretical) and actual heat transfer coefficient (Uactual) values in open systems both rise as the discharge of cold water increases, and the theoretical heat transfer coefficient (Utheoretical) value is always greater than the actual heat transfer coefficient value (Uactual). The heat exchanger needs to be in a very constant state when collecting data since the rise in fluid temperature at T2, T3, and T4 will have an impact on the actual effectiveness calculations. Meanwhile, theoretical effectiveness states that the value of effectiveness will rise with increasing cold fluid discharge.
Design of Blowdown Line LNG Filling Station ISO Tank Ariwibowo, Didik; Wahyuddin, Wahyuddin; Murni, Murni; Sutrisno, Sutrisno; Handayani, Sri Utami
Journal of Vocational Studies on Applied Research Volume 1, Issue 2, Year 2019 (October 2019)
Publisher : Vocational College of Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (638.801 KB) | DOI: 10.14710/jvsar.v1i2.4805

Abstract

LNG (Liquid Natural Gas) is a liquefied natural gas, with composition of 87% - 96% methane, 1,8-5,1% ethan, 0,1-5,1% propane and other compounds. The composition of natural gas (LNG formation) varies depending on the source and the process of its formation. Methane gas in LNG has odorless, non-corrosive and non-toxic properties (Air Products, 1999). LNG is basically an alternative method to deliver gas from producer to consumer. When cooled to -162˚C at 1 atm pressure, natural gas becomes liquid and its volume decreases up to 600 times (Handbook of Liquefied Natural Gas, 2014). With such a large volume reduction, liquefied natural gas (LNG) can be transported through the Tanker Ship and the ISO Tank Truck. PT Badak NGL has 3 (Three) T.U.K.S (Terminal For Ownership) As Tanker Ship Facilities and 1 (One) LNG Filling Station as a means of filling LNG to ISO Tank. Development of business process of PT. Badak NGL leads to an increase in LNG filling Station capacity. Along with the plan to increase the filling station capacity, the problem of BOG (Blow of Gas) wastage along with some LNG to ground flare becomes a serious concern. When the number of fillling stations is only 1 (one) station, the BOG wasted condition is not significant. However, with plans to increase the number of filling stations, BOG wasted need to be considered to be fully utilized. Therefore, there is a thought to utilize BOG to become more economic value, through the design of blowdown line on LNG ISO Tank filling station. In the Design of this line Blowdown, Using Pipe Ø2 "(PIPE BE 40S SS A312-TP305 SMLS) interconnecting with Pipe Ø6" (PIPE BE 40S SS A312-TP305 SMLS) BOG Header of new Filling Station under construction (Beginning January 2018 ).
Effect of Winglets on Improving Wind Turbine Performance Handayani, Sri Utami
Journal of Vocational Studies on Applied Research Volume 3, Issue 1, Year 2021 (April 2021)
Publisher : Vocational College of Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (328.987 KB) | DOI: 10.14710/jvsar.v3i1.10906

Abstract

Indonesia, with the longest coastline in the world, has enormous potential to develop large-scale wind energy. In wind turbines, the formation of a wake behind the wind turbine can reduce efficiency. It is estimated that the formation of a vortex tip behind the wind turbine blade can be reduced by adding a winglet. The main function of winglets attached to the blade is to reduce the effect of the wingtip vortices which are generated due to 3D spanwise flow that occurs because of the pressure non- equalization between the upper and lower blade surfaces. This paper aims to summarize the results of research on the effect of adding winglets to wind turbines.