cover
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
Journal of Vocational Studies on Applied Research
Published by Universitas Diponegoro
ISSN : -     EISSN : 26848090     DOI : -
Core Subject : 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.
Articles 35 Documents
Techno Economic Modelling of Dried Black Potato (Plectranthus rotundifolius) Pradipta Risma Rukmana Ardi; Muhammad Milzam; Vita Paramita; Didik Ariwibowo
Journal of Vocational Studies on Applied Research Volume 1, Issue 1, Year 2019 (April 2019)
Publisher : Sekolah Vokasi Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (613.915 KB) | DOI: 10.14710/jvsar.v1i1.4295

Abstract

The techno economic modeling of dried black potato (Plectranthus rotundifolius) was studied by employing electrical cabinet oven. The parameters investigated were including parameter obtained from analysis of capital budgeting, breakeven point and financial ratio of rentability. The obtained payback period was 2 years 11 months by investing 53.000.000 rupiah for machinery and 10.000.000 rupiah for start-up cost as initial capital. By assuming 10 years of dried black potato production, the value of net present value was equal to 1.207.982.611 rupiah. The value of gross profit margin and net profit margin were 0.97 and 0.87, respectively. Regarding to the positive value of net present value, the lower payback period value, and the high value of internal rate of return (74.47%) and also the profitability index (20.17), the modeling of techno economic was positively recommending the commercial application of dried black potato by using electrical cabinet oven.
The Effect of Lactic Acid Hydrolysis in the Making of Modified Maizena Flour Yusuf Arya Yudanto; Raissa Wahyu Alvina; Isti Pudjihastuti
Journal of Vocational Studies on Applied Research Volume 2, Issue 2, Year 2020 (October 2020)
Publisher : Sekolah Vokasi Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (359.853 KB) | DOI: 10.14710/jvsar.v2i2.8107

Abstract

Flour is a useful agricultural product for various foodstuffs, one type of flour obtained in Indonesia is wheat flour. The need for this flour makes the import number of Indonesia increase, whereas many other plants have great potential to be used as raw material for making flour, such as tubers, taro, corn, and others. However, the content of amino acids and sugar as an energy source in corn is still relatively low. So we need a breakthrough to improve it and can affect the quality of the final product. This experiment focused on the combination of the lactic acid hydrolysis process in addition to UV light on maize starch so that the modified product is expected to have properties that almost the same with flour. There is a variety of changing variables which is the concentration of lactic acid. The number of the concentration that we use for this research is 0.5% (w/v); 1% (w/v); 1.5% (w/v); and 2% (w/v). The score of water content that we get is decreasing. It happened because the lactic acid can weaken hydrogen bonds which causes starch molecular weight to be lower, the structure becomes tenuous and soft, so that more water is evaporated during the oven drying process. Besides, the length of the hydrolysis process also affects the water content of the flour produced, which is soaking time inversely proportional to the water content produced. This happens because the longer the reaction with lactic acid causes the hydrogen bonds in starch to be weak so that the bonds between water molecules with various other components in the material more easily broken. From the analysis, the best point of the water content and baking expansion is consequently 18.780% and 40%. From 4 concentrations used (0.5%; 1%; 1.5%; and 2%), the lowest concentrations gave the best result, because it got the highest score in the baking expansion. This research result shows that modified starch has a better characteristic than natural starch. The factor that determined the good flour is the rheology characteristic which is the baking expansion.
MAKING LIQUID SOAP FROM COOKING OIL PURIFICATION RESULTS WITH SUGARCANE WASTE ADSORBENT Rashinta Rizka Putri
Journal of Vocational Studies on Applied Research Volume 2, Issue 1, Year 2020 (April 2020)
Publisher : Sekolah Vokasi Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (814.02 KB) | DOI: 10.14710/jvsar.v2i1.7712

Abstract

Cooking oil is high enough economic value. Cooking oil is generally used to cook, but its uses are also many other than for cooking needs, such as skin beauty, lubricants and others. In the condition which the longer time, the price of cooking oil is higher than before, making some society to think creative by recycling the oil which has been used cooking oil. According to the research, it is know that sugarcane waste have strong adsorption potency to water content, and free fatty acid content that found in used cooking oil. The variable of this research are the rinsing time and the amount of sugarcane waste used. The best condition reaches to 40 gr sugarcane waste with the decrease water content reach 0.0050%; the rinse of sugarcane waste in 2x24 hours with free fatty acid intensity adsorption up to 0.23%
Optimization of clove flower oil extraction (Syzgium aromaticum L.) With Factorial Design Method Muhammad Asror Muwaffaq; Edy Supriyo
Journal of Vocational Studies on Applied Research Volume 3, Issue 2, Year 2021 (October 2021)
Publisher : Sekolah Vokasi Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (273.19 KB) | DOI: 10.14710/jvsar.v3i2.12182

Abstract

Solid-liquid extraction or commonly called leaching is the removal of the solute fraction (solute) from a solid to a liquid solvent. This extraction has become a widespread oil extraction process due to the high percentage of oil produced. Soxhletation method is an extraction method that contacts a solid and a liquid by dissolving it in the liquid phase at reflux. Clove oil is an essential oil that can be produced from distillation method on parts of the clove plant, especially the leaves and flowers of cloves. All parts of the clove plant contain oil, but the flowers contain the most oil. Because the leaves and twigs of cloves also produce oil, they also become a side income for clove farmers who harvest clove flowers for cigarettes. One of the most important ingredients in clove oil is eugenol, eugenol has many benefits from antiseptic to stimulant. Isopropyl alcohol is a unwell-known solvent specially to essential oil solvent, isopropyl alcohol is a solvent that can be recovered back into a solvent form usually using distillation method. The selection of isopropyl alcohol as a solvent is based on its high boiling point compared to other solvents and has elements of carbon, hydrogen, and oxygen that can dissolve polar molecules and their alkyl groups. 
Failure Analysis Of Water Pump Shaft Didik Ariwibowo
Journal of Vocational Studies on Applied Research Volume 1, Issue 2, Year 2019 (October 2019)
Publisher : Sekolah Vokasi Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (817.879 KB) | DOI: 10.14710/jvsar.v1i2.6301

Abstract

Abstract- A water pump shaft for utility water raw material was failed. The shaft was broken into two parts. While in dismantling, the sand was found in chamber between bearing and shaft. There was also a bolt in the impeller. According to reports, the pump has been repaired and since there was no replacement shaft but the shaft was reused in reverse position. There was no inspection of the shaft when it was disconnected by operational reasons. The failure analysis of the broken-shaft was performed to investigate the cause of the failure. Two inspection and analysis were perfomed those are visual inspection and material identification and analysis. When material analysis of the shaft was carried out there was difference between examination and data specification of the shaft.The material identification indicate that the material was AISI SS 304 whereas specification data states SS 316. Both materials have similar tensile stress, so the difference was not the contributor of the failure. The present of foreign material was consider as the cause of the failure. The foreign material caused to stucked on rotation of shaft and increasing in tensile of the shaft over its ultimate strength. Keywords – vertical pump, tensile stress, ultimate strength, material identification  
The Effect of Rotational Speed of Homogenization on Emulsion Results Obtained Using Soy Lecithin Emulsifier Zahra Rahma Namira; Vita Paramita; Heny Kusumayanti
Journal of Vocational Studies on Applied Research Volume 3, Issue 1, Year 2021 (April 2021)
Publisher : Sekolah Vokasi Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (363.661 KB) | DOI: 10.14710/jvsar.v3i1.10916

Abstract

Homogenization is the process of homogenizing particle size in an effort to maintain the stability of a mixture formed from 2 phases that cannot be fused or commonly called emulsions. This study aims to analyze the effect of homogenization speed and differences in solid concentration in homogenization process using homogenizer. The ingredients used are Virgin Coconut Oil as a solute, Aquadest as a solvent, and soy lecithin as an emulsifier. Several stages of analysis are density, viscosity, microscopic, and emulsion stability analysis. The results obtained from this study were optimum stirring speed of 22,000 rpm with optimum homogenization time of 4 minutes, solid concentration of 60% obtaining density of 0.78 gr/mL, viscosity of 5.86 cP, stability of 100%, and most stable microscope test. The results showed that the greater the stirring speed and time, the smaller the density and viscosity value produced and the greater the stability value obtained. The greater the concentration of solids, the greater the density, viscosity, and stability of the emulsion.
Reliability Analysis of Diesel Engine at LNG Plant using Counting Process Seno Darmanto; Ireng Sigit Atmanto; Bagus Hendra Permana
Journal of Vocational Studies on Applied Research Volume 1, Issue 2, Year 2019 (October 2019)
Publisher : Sekolah Vokasi Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (302.798 KB) | DOI: 10.14710/jvsar.v1i2.4368

Abstract

The purpose of this research is to analyze the reliability of diesel engine as driver for fire water pump. To determine the reliability level of the diesel engine, this research will apply counting process so that the rate of failure of the diesel engine can be known. The data used as basis for calculation is failure data gained from maintenance work order databases from 2012 to 2017. The data obtained will be processed using counting process method to produce mathematical modeling to predict the amount of failure to diesel engines in the future. From 4 diesel engines, only 3 parametric failure rate (l) that could be generated,  for 33-GE-5A,  for 33-GE-5B, and  for 33-GE-5C, since 33-GE-5D was severely damaged in September 2015.   The mathematical modeling will be verified using the Pearson's Chi-squared Test method to ensure the validity of the mathematical model can be guaranteed. The result of the goodness of fit test shows that only parametric failure rate (l) for 33-GE-5B and 33-GE-5C that could be accepted. The outcome mathematical model will be used to predict future behavior and failure of the unit so effective and efficient maintenance strategy for 33-GE-5B and 33-GE-5C could be applied
Effect of Banana Types on Oven Drying Process for Crispy Banana Production Arum Dyah Saputri; Rizka Amalia; Mohamad Endy Yulianto; Vita Paramita
Journal of Vocational Studies on Applied Research Volume 2, Issue 2, Year 2020 (October 2020)
Publisher : Sekolah Vokasi Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (543.955 KB) | DOI: 10.14710/jvsar.v2i2.9294

Abstract

This study aims to determine the effect of moisture and drying rate on Kepok and milk banana species, on the production process of crispy banana. An electric oven was used to examine the drying process at variable temperatures of 70 ºC, 80 ºC and 100 ºC with slices of 1 mm, 2 mm, 3 mm and 4 mm thickness. The results showed that the lowest moisture content and maximum drying rate obtained in Kepok was at a temperature of 100ºC, namely 69.167% and 0.045 grams/minute respectively. Meanwhile, for milk banana, the lowest moisture and the maximum drying rate was obtained at a temperature of 100 ºC, namely 68.167% and 0.042 grams/minute respectively. Furthermore, the organoleptic test results showed that kepok and milk banana experienced browning at 100 ºC, but did not at 70 ºC and 80 ºC with a thickness of 1mm, 2mm and 3mm. In addition, the pore structure of both bananas expanded, while the structure of the bananas appeared bigger after drying.
The Effect of Solid-State Anaerobic Disgestion (Ss-Ad) and Liquid Anaerobic Disgestion (L-Ad) Method in Biogas Production of Rice Husk Budiyono Budiyono; Siswo Sumardiono; Fadillah Fathir Mahmud Fofana; Ihwan Fauzi; Agus Hadiyarto
Journal of Vocational Studies on Applied Research Volume 1, Issue 1, Year 2019 (April 2019)
Publisher : Sekolah Vokasi Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (755.294 KB) | DOI: 10.14710/jvsar.v1i1.4291

Abstract

Rice husk is one of the agricultural waste from rice crop residue which has high potential to be processed into biogas. The purpose of this research is to study the effect of solid state anaerobic digestion and liquid anaerobic digestion on biogas production from rice husk waste. The anaerobic digestion laboratory scale used in this experiment is operated in a batch system and at room temperature. This method is added with chemical and biological pretreatment that was NaOH and microbial consortium. Total solid (TS) was varied from 5%, 7%, 9%, 11% which is L-AD and 17%, 19%, 21%, 23% are SS-AD. Biogas results were measured using the water displacement method every two days to determine daily production. The results showed that with the addition of NaOH the total volume of biogas obtained by L-AD method (TS 9%) and SS-AD (TS 23%) were 1254 ml and 1397 ml. Production of biogas per unit of TS for L-AD method is 46,44 ml / grTS and for SS-AD is 20,246 ml / grts, while biogas production per reactor volume unit for L-AD method is 6,26 ml / ml reactor and for SS-AD method is 4.64 ml / ml reactor. The kinetics constant of biogas production with L-AD method obtained A, U, and λ respectively were 50,53 ml / grTS, 1.23ml / grTS.day, 11,71 day, while for SS-AD method obtained A, U , and λ respectively 21.07 ml / grTS, 0.6 ml / grTS.day, 6.2 days.
UTILIZATION OF SOYBEAN OIL AS AN ANTI MOSQUITO LOTION Faradiva Sansabhilla
Journal of Vocational Studies on Applied Research Volume 2, Issue 1, Year 2020 (April 2020)
Publisher : Sekolah Vokasi Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (266.09 KB) | DOI: 10.14710/jvsar.v2i1.7726

Abstract

The use of repellents as anti-mosquito is currently feared to contain a lot of chemicals so it needs innovation to anticipate them. This study aims to make soybean oil as an innovation in making lotions and to know the manufacturing process. The method of extracting soybean oil is pressing using a Hydraullic Press. Soybean oil extraction based on 9 variables changes namely preheat temperature 100°C; 120°C; 140°C and pressure of Hydraullic Press 1800 psi; 2000 psi; 2200 psi as the test material, the best results were obtained at variable 5 with a variable 120°C and 2000 psi obtained the results of a density of 0,929 gr / ml, viscosity of 28,07 cP and a yield of 3,1%. Making lotion using variable 10 gr of the best soybean oil, Glycerin 20 gr, cetyl alcohol 4 gr, CMC 3 gr, Arabian Gom 0,5 gr and aquadest 10 ml, obtained the results of pH 6 and density 1,0428 gr/ml.Keywords: Hydraullic Press, Lotion, Soybean Oil.

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