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INDONESIA
GEMA TEKNOLOGI
Published by Universitas Diponegoro
ISSN : 08520232     EISSN : 2656582X     DOI : -
Core Subject : Science,
Computer Science & IT
Gema Teknologi Journal (pISSN : 0852-0232, eISSN : 2656-582X) is an open access journal published by Vocational School, Diponegoro University, Indonesia. Gema Teknologi publishes articles from various engineering disciplines (the results of original scientific research or new scientific studies of literature). Editor receives articles both in English and Indonesian. Gema Teknologi Journal is published 2 (two) times a year, on April and October.
Arjuna Subject : -
Articles 7 Documents
 1 
Search results for , issue "Vol 21, No 2 (2021): October 2020 - April 2021" : 7 Documents clear
EFEK PENAMBAHAN EVAPORATOR PADA ATMOSPHERE WATER HARVESTER (AWH) TERHADAP PERFORMA SISTEM Juli Mrihardjono; Didik Ariwibowo; Sutrisno Sutrisno; Dista Yoel Tadeus
Gema Teknologi Vol 21, No 2 (2021): October 2020 - April 2021
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v21i2.33448

Abstract

Atmosphere Water Harvester (AWH) was investigated to get water collected from air in elevated performance. Improvement was performed by introducing a series-arrangement of two evaporators. Air flew through the evaporators in cross-flow. This arrangement would influence performance of the AWH system in title of COP, MHI, and specific energy consumption. The AWH was designed using vapor compression refrigeration system. Parameter measured to the system were refrigerant temperature in suction and discharge line, inlet and outlet pipe wall temperatures at evaporator and condenser, air velocity enter into evaporator, and electrical energy consumption. Instrument used in this research were refrigerant pressure-temperature gauge, K-type digital thermometer, digital fan anemometer, thermo-hygro meter, and kWh meter. Air temperature and RH data were 36,5 oC, 40%, and 19 oC, 42 %  for inlet and outlet air stram at evaporator, subsequently. With air velocity 1.5 m/s, the COP of the system was 3.7. Water collected  from AWH was 1.1 litres/hour with energy consumption of 1.24 kWh. The AWH could be considered as a water harvester with value of specific energy of 1.13 kWh/litre and MHI of 0,2.
TRANSESTERIFIKASI MINYAK KELAPA MENJADI BIODIESEL DENGAN KATALIS CAO DAN PENERAPAN BIODIESEL (B40) PADA ALAT FOGGING Maria Stefani Bethan; Edy Supriyo
Gema Teknologi Vol 21, No 2 (2021): October 2020 - April 2021
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v21i2.37297

Abstract

Biodiesel is a renewable fuel from a transesterification reaction in which triglycerides are converted into FAME with alcohol. Previous research proved that coconut oil can be used as biodiesel. This study aimed to determine the effect of temperature (40-60oC), catalyst concentration of CaO 2-5%w/w) and methanol (20-40%w/w) on the yield of biodiesel produced. The yield were then compared with the biodiesel specification from Pertamina, i.e. density, viscosity, acid number, flash point and cetane number. The result of present work showed that the transesterification reaction between coconut oil and methanol with CaO catalyst have got a reaction conversion of 75% at 60oC, for 2 hours. For producing biodisel, the optimum conditions were achieved when using methanol 20% w/w and a concentration of CaO 2% w/w. The specification biodiesel were as followed: density 836 kg/m3, viscosity 3.09 mm2/sec, acid number 0.37 mgKOH/gr, flash point 62oC, and Cetane value 50.5. In the application, biodiesel (B40) from coconut oil on a fogging machine with a noise of 81.5 dB. 
PENGEMBANGAN KONSEP OPEN GOVERMENT UNTUK MENINGKATKAN KUALITAS LAYANAN KOTA PALEMBANG (STUDI KASUS : KOTA PALEMBANG) Tri Akhyari Romadhon; M. Izman Herdiansyah
Gema Teknologi Vol 21, No 2 (2021): October 2020 - April 2021
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v21i2.36650

Abstract

Open Government is committed to improving the quality of information availability on government activities, supporting civil society participation in government, upholding professional standards in public administration to prevent corruption, abuse of power and increasing access to the use of new technologies to support accountability and openness. Currently, many governments have implemented e-government which supports the government's goals in open government. Where, e-government is used to describe the use of technology in carrying out several government tasks. The city government of Palembang has several applications or e-government systems that are open government. The city government of Palembang has not made a quality measurement of the e-government that has been implemented, so it is not known the level of quality in each application or system implemented. Based on this explanation, it is necessary to analyze the level of service quality in the system that has been implemented by the Palembang City Government.
SISTEM INVENTARISASI PENGGUNAAN PERALATAN DAN BAHAN PADA MEJA PRAKTIKUM PLC DI POLITEKNIK MANUFAKTUR NEGERI BANGKA BELITUNG MENGGUNAKAN BARCODE SCANNER Nofriyani Nofriyani; Adhi Budiono; Charlotha Charlotha; Indra Dwisaputra; Dedy Ramdhani
Gema Teknologi Vol 21, No 2 (2021): October 2020 - April 2021
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v21i2.31659

Abstract

In the Programmable Logic Controller (PLC) course at Polmanbabel, students use a practicum table containing practicum equipment such as computer units, compressors, PLC units, pneumatic valves, sensors, jumper cables, etc. Before and after practicum, students are required to do an inventory of equipment and materials contained on this practicum desk. The inventory process is still done manually, where students write the name of the equipment, check the presence of the equipment, and calculate the amount. The thing that was complained by lecturers was the confiscation of practicum time as a result of the manual inventory process. Based on this, a new inventory system was created that uses the application and is equipped with a barcode scanner that is able to minimize the time and possibility of misplacement of the device. Based on the results of experiments, it can be seen that this system is able to minimize inventory time by an average of 14.65 minutes compared to manual inventory systems.
ANALISA KINERJA CNG COOLER PADA SISTEM CNG PLANT Seno - Darmanto; Muhammad Fahrudin
Gema Teknologi Vol 21, No 2 (2021): October 2020 - April 2021
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v21i2.17963

Abstract

CNG Cooler is a heat exchanger in CNG Plant System which has function to reduce CNG temperature. CNG (Compressed Natural Gas) is natural gas which compressed by gas compressor from normal pressure up to certain high pressure. CNG Plant is gas storage and supply facility for PLTGU when it work at peak load hours. CNG Cooler reduce temperature of CNG which out from gas compressor before saved in storage utility which purpose to avoid over heating in the next process, increase durability of the next process utility, and make gas storage utility design easy.
PENGARUH RASIO BAHAN BAKU TEPUNG KOMPOSIT (UBI KAYU, JAGUNG DAN KEDELAI HITAM) PADA KUALITAS PEMBUATAN BERAS ANALOG Isti Pudjihastuti; Edy Supriyo; Hafiz Rama Devara
Gema Teknologi Vol 21, No 2 (2021): October 2020 - April 2021
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v21i2.32923

Abstract

The increase population affects an increase in total of consumption of Indonesian people towards rice, which encourages Indonesia to import rice. One of the alternatives that can be done is by using potential non-rice raw materials such as tubers. In this study, the raw materials for composite flour from cassava (Manihot esculenta), corn (Zea mays) and black soybeans (Glycine Sojo) were used, which are the basic ingredient for analog rice. The purpose of this study was to examine the effect of raw material composition on nutritional value (carbohydrate, protein, fat, water and ash content) analog rice compared to ordinary rice, examine the physico-chemistry (kamba density, water absorption and cooking time) of analog rice compare to paddy rice and also to define raw material composition and best temperature, organoleptic test covering color, aroma, texture and taste. The process of making analog rice consists of several stages of research, such as the stage of making composite flour, cooking the composite flour dough, making analog rice, drying analog rice and analyzing the results. The variables used were the ratio of flour composition and the effect of extrusion temperature. Based on proximate analysis on various compositions, obtained sample 5 (60% cassava flour, 15% corn flour and 25% black soybean flour) as analog rice with the best formulation. Based on the proximate analysis of the effect of temperature, the temperature was 75 °C as the optimum temperature for the extraction process. The results of the physical analysis of the best analog rice in this study showed that analog rice from a composite of cassava flour, corn flour and black soybean flour had a kamba density of 0.46 g / mL, a water absorption capacity of 60.52% and a cooking time of 46 minutes. In this sample, analog rice has a texture, aroma and appearance similar to rice in general, although analog rice from composite flour tends to have a savory taste arising from black soybeans.
SURVEI METODE PENGUKURAN APLIKASI CHATBOT BERBASIS MEDIA SOSIAL Ratna Ayu Sekarwati; Ahmad Sururi; Rakhmat Rakhmat; Miftahul Arifin; Arief Wibowo
Gema Teknologi Vol 21, No 2 (2021): October 2020 - April 2021
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v21i2.36170

Abstract

The design of Chatbot aims to facilitate social activities in all areas to be considered. Chatbot is one type of machine that can communicate with humans using natural language. Communication happening via chat is a written conversation. Chatbot is a form of application implementation from Natural Language Processing (NLP) that belongs to one branch of artificial intelligence or Artificial Intelligent (AI). Social Media now provides a service that allows developers to process and integrate chatbot applications. This paper aims to review the papers that build chatbot applications in various social media using various testing methods. The contribution of this paper is to determine which method is able to measure the level of chatbot accuracy well. This review paper will choose the equation of the most widely used test methods and social media from various papers so that further research is expected to implement the right testing methods and use better social media in terms of user experience, features, and services. The review paper shows that the Black-box and System Usability Scale testing methods are most used in the review paper. This testing method is a type of method that performs testing of the flow and how the chatbot works to achieve functional validation throughly.

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