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Journal of Vocational Studies on Applied Research

jvsar
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Published by Universitas Diponegoro

ISSN : - EISSN : 26848090 DOI : -

Core Subject : Engineering,

Engineering

Journal of Vocational Studies on Applied Research [e-ISSN 2684-8090] is an open access peer reviewed journal published by Vocational School Diponegoro University Semarang Central Java Indonesia. Journal of Vocational Studies on Applied Research is an Journal publishing academic and industrial topics which covers area of interest on applied research as well as vocational studies. Research papers on Engineering, Science and Vocational Studies are welcomed. The Journal is double-blind reviewed which accepts Original Research Paper, Short Communication and Review Articles.

Arjuna Subject : Teknik (semua kategori) - Teknik (Lain-Lain)

Articles 75 Documents

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The Effectiveness of Biosorbent from Chicken’s Egg Shell and Durian Peel towards the Quality of Biodiesel Product from Waste Cooking Oil Kristanto, Dwi; Pudjihastuti, Isti; Amalia, Rizka
Journal of Vocational Studies on Applied Research Volume 3, Issue 2, Year 2021 (October 2021)
Publisher : Vocational College of Universitas Diponegoro

Indonesia is the largest exporter of palm oil with 85 - 90% of the world's total palm oil production. The consumption of palm oil in Indonesia is increasing every year, thus the waste are also increase. Waste cooking oil contains carcinogenic substances which causes various diseases. Biodiesel is an environmentally friendly substitute fuel for diesel made from vegetable oil as raw material. Used cooking oil can be used as raw material for biodiesel production, but it needs to be purified before further processing. Chicken egg shell contains 90% of CaCO3 can be used as a biosorbent of used cooking oil. Durian skin contains 50% - 60% of cellulose also has the potential as a biosorbent. This research was conducted to investigated the effectiveness of the combination of chicken egg shell biosorbent with durian skin for the purification process of used cooking oil as a raw material of biodiesel. Biosorbent was produced by carbonization process in a furnace at a temperature of 550oC for durian skin and 9000C for chicken egg shells. The results show that the acid number of used cooking oil has met the parameters of the SNI 3741: 2013, namely 0.43 mgKOH / gr and FFA levels of 0.0024% with a yield of 62.76%. The purified cooking oil was then continued with the transesterification process to produced biodiesel. The biodiesel obtained had the cetane numbers B100 of 33.8 and B30 of 45.2.

Optimisation of Tapioca Oxidative Reaction by Ozone Treatment: Effect of pH, Process Time and Temperature Sumardiono, Siswo; Pudjihastuti, Isti; Supriyo, Edy; Siswanto, Anggun Puspitarini
Journal of Vocational Studies on Applied Research Volume 2, Issue 1, Year 2020 (April 2020)
Publisher : Vocational College of Universitas Diponegoro

Modification of cassava starch was produced by oxidation using ozone treatment. The oxidized starch is used in the paper processing in the pulp and paper industries. The aim of this research was to determine the effect of reaction conditions (pH and temperature) in produced oxidized starch. The oxidative reaction of cassava starch was using ozone as an oxidator while the operating condition was at temperatures of 30, 35, 40 and 45 oC in atmospheric pressure. The fixed variables were weight of cassava starch 80 grams, and volume of aquadest 200 ml. The change variables are reaction time (15, 30, 45 and 60 minutes) and pH solution (6, 7, 8 and 9). The product of oxidized starch was analyzed for carboxyl group according to JEFA method, swelling power according to Leach method and solubility according to Kainuma method. The result of this research shows with an increasing of pH reaction and reaction time, the carboxyl group and solubility increased, but swelling power decreased. The best condition was obtained at the pH of 9 with 60 minutes of reaction time.

Impact of Fintech on Student Lifestyle In Pekalongan City, Indonesia Mahmudah, Dina Amalia; Milzam, Muhammad
Journal of Vocational Studies on Applied Research Volume 3, Issue 1, Year 2021 (April 2021)
Publisher : Vocational College of Universitas Diponegoro

This research aimed to know the effect of fintech to students' lifestyle in Pekalongan City. The subjects of this study were 100 university students who were 18-22 years old. The data were collected using interview and questionnaire. The data analysis of this research using descriptive statistical analysis. The result of this research showed that the decision to take a lending online or not is influenced by several reasons. There were 47% of students use PTP Lending to fulfill their desires not their needs. Electronics are the items most bought from the loan money.

Failure Analysis at Stem Valve Fire Hydrant in LNG Plant Mrihardjono, Juli; Pohan, Herman Abidin; Darmanto, Seno
Journal of Vocational Studies on Applied Research Volume 1, Issue 2, Year 2019 (October 2019)
Publisher : Vocational College of Universitas Diponegoro

Hydrant is one of fire extinguisher fix system that use pressure water and flowed through the pipes and fire hose. There are more 250 Hydrant in this LNG Plant and based on finding at the field, many stem valve of outlet hydrant in fracture condition, therefore the author wants to analyze about the problem from this material, this reserch aims to find out root cause dan conduct failure analysis, method of reserch that conducted is visual check to predict possible cause from failure of stem valve fire hydrant and then conducted fractographic analysis to find out what type of fracture that happen to this material and Tensile Strenght Test to Find out the the actual strenght of the material

Optimization of Oil and Methanol Ratio, Time, and Reaction Temperature of Biodiesel Making from Kemiri Sunan Oil (Trisperma Oil Reuteals) with Two Stage Transesterification Pranita, Zahra Aumy; Paramita, Vita; Amalia, Rizka; Kusumayanti, Heny
Journal of Vocational Studies on Applied Research Volume 2, Issue 2, Year 2020 (October 2020)
Publisher : Vocational College of Universitas Diponegoro

Biodiesel is an alternative fuel which is generally produced from the transesterification process between vegetable oil and methanol, ethanol, or butanol with the help of a catalyst which aims to speed up the reaction. The raw material for making biodiesel, namely renewable vegetable oil, also sees Indonesia as a tropical country so that biodiesel can be produced on a large scale and is environmentally friendly. Vegetable oil can be classified into two, namely edible oil (food) and non edible oil (non-food). The research was conducted using non-edible vegetable oil, namely kemiri sunan oil, which was carried out using a two-stage transesterification method. This research was conducted to determine the optimization of the ratio of oil and methanol (1: 4; 1: 5; 1: 6), temperature (55⁰C, 60⁰C, 65⁰C) and reaction time (15 minutes, 30 minutes, 45 minutes) in making biodiesel from kemiri sunan oil, where the experimental results obtained the highest yield value of 82.79%. In the experiment, analysis of density, viscosity, moisture content and cetane number was also carried out. The results showed that the viscosity and cetane number obtained did not meet SNI for biodiesel.

Optimization On Subcritical Fluid Extraction Of Zingiberene Paramita, Vita; Yulianto, Mohamad Endy; Hartati, Indah; Bahrudin, Udin; Broto, R. T. D. Wisnu
Journal of Vocational Studies on Applied Research Volume 1, Issue 1, Year 2019 (April 2019)
Publisher : Vocational College of Universitas Diponegoro

The establishment of subcritical fluid application for zingiberene extraction was studied by employing water as a green solvent. The zingiberene content was observed by using Liquid Chromatography-Mass Spectrofotometry and regarding to the independent variable of temperature, extraction time, ginger-solvent ratio and aging time. By applying subcritical water, the critical value of zingiberene content obtained was 0.036%. This value was approached by the surface modeling of alpha for rotatability design which performed at 125 oC, 20 min of extraction time, 0.08 of ginger to solvent ratio and 9 min of aging time of extraction parameters. The surface modeling was validated by plotting the observed and predicted value of zingiberene content and evidenced by the value of R-square at 0.76.

Discipline Parameter (A Study on Civil Servant’s Work Discipline in Central Java Provincial Court) Sukoco, Johan Bhimo; Ulya, Fika Ni’matul
Journal of Vocational Studies on Applied Research Volume 2, Issue 2, Year 2020 (October 2020)
Publisher : Vocational College of Universitas Diponegoro

An organization needs to improve its employees’ work discipline. It is important recalling that the objective of organization will be achieved difficultly without the employees’ work discipline. This research studied the work discipline of Civil Servants in Central Java Provincial Court. This study was analyzed using 5 (five) discipline parameters: compliance with work hour and superior’s instruction, compliance with dressing rule, using office facilities well, and working according to the rule (Enceng and Suryarama, 2013). The research method employed in this study was descriptive one with qualitative approach. Primary and secondary data was used in this study. The methods of collecting data used were interview, observation, and documentation study. This study employed an interactive analysis. The result of research showed that parameters of compliance with work hour and superior’s instruction, and compliance with dressing rule such as wearing institution identity card have not been compatible yet with discipline parameters. Meanwhile, the parameter of using office facilities well has been compatible, but archiving aspect has not fulfilled yet the discipline parameter. Parameter of working according to the rule has been compatible, despite some servants asking for permission to get out the office beyond the time limit.

Quality Analysis of Liquid Soap Formulation Made from Virgin Coconut Oil with Addition of White Tea Extract Meizalin, Anna Amelia; Paramita, Vita
Journal of Vocational Studies on Applied Research Volume 3, Issue 2, Year 2021 (October 2021)
Publisher : Vocational College of Universitas Diponegoro

The production of bath soap based on natural ingredients is still rarely found in the market. Many in circulation still use synthetic materials as active ingredients. In this soap-making formulation using natural antioxidants in the form of white tea extract, anti-oxidants from plant extracts are usually added as additives (1-8% of the final soap composition). The research method used is a response surface methodology with a Central Composite Design (CCD) design. The resulting liquid soap product will be analyzed including physicochemical tests and organoleptic tests. Soap with the most appropriate quality according to SNI fell on the 4th variable, with the addition of KOH of 67 grams and a reaction time of 35 minutes. Variable soap 4 has a pH of 10, a free alkali content of 0.0541%, and an unsaponifiable fat content of 0.37%.

Corona Virus Pandemic Impact on Sales Revenue of Micro Small and Medium Enterprises (MSMEs) in Pekalongan City, Indonesia Milzam, Muhammad; Mahardika, Aditia; Amalia, Rizka
Journal of Vocational Studies on Applied Research Volume 2, Issue 1, Year 2020 (April 2020)
Publisher : Vocational College of Universitas Diponegoro

This study aims to determine the impact of the covid-19 pandemic on the sales revenue of Micro Small and Medium Enterprises (MSMEs) in Pekalongan City. The data collected from surveys are sales revenue before and after Corona virus Pademic starting from the enactment of social distancing rules (March 16 2020 until 16 April 2020). The analysis carried out in the form of data analysis and descriptive data analysis. Based on 282 SMEs units sampled, it was found a decrease in total sales revenue of 53.5%. The type of business that has the greatest reduction in revenue sales is the fashion business. The corona virus pandemic has an economic impact to the community, especially to the Micro Small and Medium Enterprises (MSMEs) in Pekalongan City. This research is expected to be a policy reference for the local governments to deal with the economic crisis caused by the corona virus pandemic.

The Effect of Surfactant, Time and Speed of Stirring in the Emulsification Process of Soybean Oil in Water Hariyatno, Shelvin Putri; Paramita, Vita; Amalia, Rizka
Journal of Vocational Studies on Applied Research Volume 3, Issue 1, Year 2021 (April 2021)
Publisher : Vocational College of Universitas Diponegoro

Homogenization is the process of uniform particle size in an effort to maintain the stability of a mixture which is formed from 2 incompatible phases or so-called emulsion.Emulsion is a complex system consisting of a liquid phase which is spread over another immiscible liquid phase which is usually through mechanical shear. All emulsions are thermodynamically unstable due to contact between oil and water molecules. However, emulsions can be stabilized rapidly in the presence of emulsifying or thickening agents such as Tween 20 and Tween 80. Apart from the addition of emulsion stabilizing surfactants, the speed of stirring also has an effect in stabilizing the emulsion. This research was conducted to determine the effect of stirring speed and addition of surfactants Tween 20 and Tween 80 on the stability of soybean oil emulsion. The results of density, viscosity, stability, and microscopic tests showed that the emulsion was treated with the addition of tween 80 with a stirring speed of 30.

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Eko Didik Widianto

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jvsarvokasiundip@gmail.com

Editorial Address
Vocational School of Diponegoro University Jl. Prof. H. Soedarto, S.H. Tembalang, Semarang 50275

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Kota semarang,

Jawa tengah

INDONESIA

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Abstract

Home Page

OAI Link

Editorial Team

Contact

Reviewer

Google Scholar

Contact Name Eko Didik Widianto

Contact Email rumah.jurnal@live.undip.ac.id

Phone -

Journal Mail Official jvsarvokasiundip@gmail.com

Editorial Address Vocational School of Diponegoro University Jl. Prof. H. Soedarto, S.H. Tembalang, Semarang 50275

Location Kota semarang, Jawa tengah INDONESIA

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Contact Name
Eko Didik Widianto

Contact Email
rumah.jurnal@live.undip.ac.id

Phone
-

Journal Mail Official
jvsarvokasiundip@gmail.com

Editorial Address
Vocational School of Diponegoro University Jl. Prof. H. Soedarto, S.H. Tembalang, Semarang 50275

Location
Kota semarang,

Jawa tengah

INDONESIA