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Widya Teknik
Published by Universitas Katolik Widya Mandala Surabaya
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Core Subject : Engineering,
Chemical Engineering, Chemistry & Bioengineering
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 272 Documents
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Integration of Rough Cut Capacity Planning (RCCP) and Capacity Constraint Resources (CCR) to Minimize the Risk of Uncertainty in Fulfilling Production Material Supply Salsavira, Nardha Livia; Yuliawati, Evi; Rahmawati, Nur; Trihastuti, Dian
Widya Teknik Vol. 22 No. 2 (2023): November
Publisher : Fakultas Teknik, Universitas Katolik Widya Mandala Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33508/wt.v22i2.4959

Abstract

Managing the production capability of a company is undoubtedly the main concentration in the manufacturing industry. Industries must consider the materials and resources supplied for making a master production schedule. The lack of material supply from a supplier results in the inefficiency of the production process. The supply disruption of raw materials results in problems for the rest of the stages in the production process. As a result, companies experience difficulties in meeting the predetermined target. This research used an integration of RCCP and CCR to solve the problem. Optimization of CCR implies the TOC (theory of constraint) principle by reducing the percentage of overload until reaching a balanced (optimal) condition. This research aims to balance and optimize the ongoing production process. It took place in a manufacturing company that produces building materials serving the market in Indonesia. The results show that during the observation period, the current production system has experienced system overload for about 70% of the production period. The results of the RCCP analysis provide recommendations for improving the master production schedule to increase the effectiveness of the production system.
Implementation and Comparative Analysis of Test Automation Framework Performance for Functional Testing of Web-Based Applications using the Distance to the Ideal Alternative (DIA) Method Adiatma, Shidqi; Darmayantie, Astie
Widya Teknik Vol. 22 No. 1 (2023): May
Publisher : Fakultas Teknik, Universitas Katolik Widya Mandala Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33508/wt.v22i1.5027

Abstract

The importance of functional testing is to ensure the quality of web-based applications so as to improve user experience (user experience) to make it more secure and reliable in ever-increasing market pressure. Can encourage many companies to build high-quality applications and he can release in a short time. Because of this, the testing process must be automated to ensure applications run quickly and effectively. There are several test automation frameworks, specifically for web-based applications that offer effective features and performance to test applications more effectively, such as Katalon Studio, Cypress and WebDriverIO. The purpose of this research is to find the best test automation framework based on performance with certain parameters and sub-parameters. The author runs functional testing on each test automation framework with several test cases and provisions from each framework in a web-based application, and generates reports from each framework with automation testing progress parameters and tool usability parameters using The Distance To The Ideal Alternative method (DIA), and determine the weight for each parameter and sub-parameters. The results of a comparative analysis of test automation frameworks for web-based applications show that WebDriverIO has the best performance compared to other test automation frameworks with a value of 0 in the DIA Method, indicating that WebDriverIO has zero distance from the ideal alternative.
Antibacterial Activity and Polyphenols Content of Methanolic Extract of Sapindus Rarak Murni, Asmara; Rohman, Aufur; Angkawijaya, Artik Elisa; Santoso, Shella Permatasari
Widya Teknik Vol. 22 No. 2 (2023): November
Publisher : Fakultas Teknik, Universitas Katolik Widya Mandala Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33508/wt.v22i2.5409

Abstract

The study focused on the methanolic extract of lerak fruit (Sapindus rarak DC.). The effect of varying extraction time and temperature on the polyphenols content of lerak extract was evaluated, that is by determining the total phenolic content (TPC), total flavonoid content (TFC), and total saponin content (TSC). The increasing extraction temperature from 30°C to 70°C was found to give increase in TPC from 172 mg GAE/100 mg to 246 mg GAE/100 mg, further increase of extraction temperature to 90°C results in the decrease of TPC. Similar effect was also observed in TFC, where TFC was found to increase as the extraction temperature was increased to 70°C, with TFC of 79 mg QE/100 mg. TSC of lerak fruit extract at 70°C was found to be 17.6 mg/100 g. Antibacterial activity assay on the lerak fruit extract shows the potential inhibitory activity of the extract on the growth of Escherichia coli and Staphylococcus aureus, wherein 95% inhibition efficiency can be achieved after the incubation of the bacteria in media containing 15 wt.% of the extract. The more prominent inhibitory effect of the extract was shown against Escherichia coli than Staphylococcus aureus. Collectively, the results of this study has demonstrated the potential of lerak fruit extract as natural antibacterial agent with foaming ability, which can be used as detergent additive.
Adsorption of Methylene Blue Dye Using Guaran/TiO2 Hydrogel Lee, Tommy; Samsuar, Marcelina; Yuiana, Maria; Santoso, Shella Permatasari
Widya Teknik Vol. 22 No. 2 (2023): November
Publisher : Fakultas Teknik, Universitas Katolik Widya Mandala Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33508/wt.v22i2.5415

Abstract

Natural polysaccharide, namely guar gum (guaran), was utilized as the raw material for preparing hydrogel adsorbent, TiO2 was added into the hydrogel to enhance the adsorption capacity. In this work, methylene blue dye was chosen as the adsorbate model to evaluate the adsorption efficiency of the prepared guaran/TiO2 hydrogel. Several physicochemical characterizations were performed to elucidate the characteristic of the hydrogel, including scanning electron microscopy and Fourier transform infrared spectroscopy. The effect of temperature and pH on the adsorption efficiency of the guaran/TiO2 hydrogel toward methylene blue was evaluated. The result of the study reveals that the use of guaran/TiO2 hydrogel allow 69% removal of methylene blue from solution, and the maximum adsorption capacity was found to be 224 mg/g at system pH of 10 and temperature of 303K. The adsorption process was found to fit with the Langmuir model, indicating homogenous surface energy of the adsorption sites. The evaluation on the thermodynamic parameters of the adsorption indicates the spontaneous and exothermic behavior of the adsorption. This study demonstrated the potential of the guaran for preparing an environmentally friendly hydrogel, which can be a good choice of adsorbent for wastewater treatment.
Preparation of Clay Minerals – Natural Surfactant Composites to Remove Organic Dyes and Heavy Metals Laysandra, Livy; Kurniawan, Darwin; Soetaredjo, Felycia Edi; Ismadji, Suryadi
Widya Teknik Vol. 22 No. 2 (2023): November
Publisher : Fakultas Teknik, Universitas Katolik Widya Mandala Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33508/wt.v22i2.5417

Abstract

The rapid development of industry is considered to be the main cause of various environmental problems, which are mainly caused by the discharge of wastewater which contains many hazardous compounds. Dyes and heavy metals are type of hazardous substances that are often found in industrial wastewater and cause ecosystem damage. Dyes and heavy metals are more difficult to remove due to their inability to be broken down, so they can build up and reach dangerous levels. Adsorption is a straighforward and efficient method for dealing with hazardous substance contamination in water. Clay minerals, known for their efficient adsorption properties, were chosen for this procedure. Clay minerals are porous materials so they are suitable for use as adsorbents. The intercalation technique is a robust strategy to further increase the adsorption capacity of clay minerals, which is done by treating clay minerals with surfactants. Clay minerals modified with natural surfactants are considered as a potential choice for removal procedures. The use of this natural surfactant was chosen because of its excellent adsorption capacity and environmentally friendly properties. Polar lipids, natural surfactants, are commonly present in the lipid layers of plants and animals. This review focuses on the synthesis of modified clay minerals using different natural surfactants such as soybeans, saponins, lipopeptides, and rhamnolipids, as well as the use of alternative clay mineral/natural surfactant composites. This review describe various types of natural surfactants that can be used to modify clay minerals and their application in the adsorption process.
A Review of the Development and Role of Heterogeneous Catalysts for Biodiesel Production Yuliana, Maria; Ismadji, Suryadi; Wijaya, Christian Julius; Soetaredjo, Felycia Edi; Gunarto, Chintya; Santoso, Shella Permatasari; Putro, Jindrayani Nyoo; Anggorowati, Adriana Anteng; Lourentius, Suratno
Widya Teknik Vol. 23 No. 1 (2024): May
Publisher : Fakultas Teknik, Universitas Katolik Widya Mandala Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33508/wt.v23i1.5453

Abstract

Indonesian regulations regarding the implementation of B30 encourage a significant increase in biodiesel demand. Moreover, this implementation will continue to be increased to B35 in 2025 and is projected to reach B100 in 2045. This high demand for biodiesel needs to be supported by the development of adequate biodiesel production technology where the catalyst is one aspect that plays an important role in biodiesel production. The use of catalysts aims to accelerate biodiesel production so that high biodiesel yields and good quality are achieved. In biodiesel production, the choice of catalyst greatly influences the operating conditions, the products produced, the subsequent purification process, and the environmental impacts. Moreover, the changing trend in biodiesel raw materials from food to non-food ingredients requires the development of catalysts that are more suitable for the raw materials used in biodiesel production. The specific characteristics of each catalyst play an important role in the transesterification reaction to produce biodiesel where this needs to be supported and adapted to optimum operating conditions, especially in terms of alcohol-to-oil molar ratio, catalyst amount, temperature, pressure, and reaction time. This review provides a comprehensive overview of the various heterogeneous catalysts used to assist the transesterification reactions in biodiesel production.
A Review of Biofuels and Their Positive Impacts on Health and the Environment Yuliana, Maria; Ismadji, Suryadi; Wijaya, Christian Julius; Soetaredjo, Felycia Edi; Lie, Jenni; Hartono, Sandy Budi; Irawaty, Wenny; Puspitasari, Nathania; Lourentius, Suratno
Widya Teknik Vol. 23 No. 1 (2024): May
Publisher : Fakultas Teknik, Universitas Katolik Widya Mandala Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33508/wt.v23i1.5454

Abstract

Indonesia's high population and rapid economic growth are driving a major transformation in the transportation sector, which is in line with the high increase in fuel demand. The need for biofuel as a substitute for conventional fuel is increasingly being prioritized by considering sustainable development goals (SGDs). Biofuel has safer health and environmental impacts than conventional fuel but still has fuel performance that meets fuel standards and engine performance. Biofuels can be derived from a variety of more sustainable and abundant raw materials, such as biomass and vegetable oils. In this review biodiesel, hydrogenated vegetable oil (HVO), and direct vegetable oil (SVO) are discussed in depth regarding the transformation of their production processes and their impacts on health and the environment. Biodiesel is one of the most widely developed and implemented compared to HVO and SVO to encourage the use of renewable energy in various aspects of people's lives in Indonesia. These three biofuels have different fuel characteristics and performance but can continue to be developed in the future to increase the implementation of renewable energy more massively.
Sintesa Biodiesel dari Minyak Nyamplung Menggunakan Katalis Heterogen Termodifikasi Hindarso, Herman; Ayucitra, Aning; Asri, Nyoman Puspa
Widya Teknik Vol. 23 No. 1 (2024): May
Publisher : Fakultas Teknik, Universitas Katolik Widya Mandala Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33508/wt.v23i1.5498

Abstract

Biodiesel merupakan bahan bakar alternatif terbarukan dan bersifat ramah lingkungan. Prinsip pembuatan biodiesel adalah mengubah bahan baku trigliserida menjadi metil ester melalui reaksi transesterifikasi. Trigliserida dapat diperoleh dari minyak nabati dan lemak hewan. Pada penelitian ini biodiesel didapatkan dari proses esterifikasi dan transesterifikasi minyak nyamplung sebagai sumber minyak nabati. Proses esterifikasi dilakukan terlebih dahulu untuk mengurangi kadar asam lemak bebas pada minyak nyamplung yang awalnya memiliki kadar 26,27% hingga turun menjadi 1,71%. Selanjutnya dilakukan proses transesterifikasi untuk mereaksikan minyak nyamplung dengan methanol agar menghasilkan biodiesel menggunakan katalis heterogen yaitu zeolit dan bentonit yang telah dimodifikasi. Modifikasi katalis dilakukan dengan aktivasi zeolit dan bentonit alam menggunakan asam HCl pada suhu 100 oC selama 24 jam dan dilanjutkan kalsinasi pada suhu 550 oC selama 4 jam. Katalis zeolit dan bentonit hasil modifikasi kemudian dianalisis karakteristiknya menggunakan uji XRD dan FTIR. Proses transesterifikasi untuk memperoleh biodiesel berlangsung pada suhu 50, 60, 65, dan 70˚C selama waktu reaksi 5 jam. Hasil biodiesel dengan perolehan terbesar didapatkan pada suhu 60 oC, yaitu sebesar 88,19% menggunakan katalis zeolit termodifikasi, 78,84% menggunakan katalis bentonit termodifikasi dan 82,36% menggunakan campuran katalis zeolit dan bentonit termodifikasi pada rasio 1 : 1. Biodiesel hasil pada perolehan terbesar dengan katalis zeolit termodifikasi dilakukan pengujian karakteristiknya sesuai parameter SNI, dan mendapatkan hasil yaitu memiliki densitas 887 kg/m3, viskositas 5,633 mm2/s, bilangan setana 53, titik nyala pada suhu 121˚C, dan kadar metil ester sebesar 94,55%.
Penentuan Rute Terpendek Pada PT. SES dengan Menggunakan Algoritma Modifikasi Clarke and Wright Savings Setiawan, Angga; Sianto, Martinus Edy; Dewi, Dian Retno Sari
Widya Teknik Vol. 23 No. 2 (2024): November-Profesi Insinyur
Publisher : Fakultas Teknik, Universitas Katolik Widya Mandala Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33508/wt.v23i2.5542

Abstract

Vehicle Routing Problem (VRP) merupakan masalah optimasi yang melibatkan pencarian rute yang paling efisien untuk sebuah armada kendaraan dalam melayani sejumlah pelanggan dengan memperhatikan berbagai batasan. Penyelesaian masalah VRP bisa dilakukan dengan menggunakan berbagai cara, salah satunya adalah dengan menggunakan Clarke and Wright Savings. Penelitian ini mengembangkan algoritma Clarke and Wright Saving yaitu dengan menambahkan pembatas time window dan kapasitas angkut kendaraan. Dengan pengembangan modifikasi ini, algoritma menghasilkan penghematan jarak sebesar 1315,3 km, dengan persentase penghematan jarak tempuh adalah 25%. Biaya yang dapat dihemat setelah menggunakan modifikasi algoritma ini adalah sebesar Rp 1.313.358,67.
Penerapan Metode Economic Order Quantity (EOQ) dalam Pengendalian Bahan Baku Pada UKM Gula Merah Herawati, Lenny; Lourentius, Suratno; Ningkeula, Ririn
Widya Teknik Vol. 23 No. 1 (2024): May
Publisher : Fakultas Teknik, Universitas Katolik Widya Mandala Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33508/wt.v23i1.5703

Abstract

Permintaan pasar yang tinggi menyebabkan permasalahan dalam kegiatan produksi yang tidak disadari oleh UKM. Salah satu permasalahan yang sering dihadapi oleh perusahaan adalah terjadinya kekurangan dan kelebihan bahan baku yang menyebabkan UKM menjadi kurang produktif dalam proses produksinya. Pengelolaan bahan baku yang baik dan benar akan membantu kelancaran proses produksi sehingga pesanan konsumen dapat dipenuhi dalam waktu yang relatif lebih cepat. Economic Order Quantity (EOQ) merupakan metode yang digunakan untuk mengoptimalkan pembelian bahan baku yang dapat menekan biaya persediaan sehingga efisiensi persediaan pada UKM dapat berjalan dengan baik. UKM gula merah ini merupakan usaha pembuatan gula merah dengan bahan baku tebu. Pada tahun 2020, UKM membeli bahan baku sebanyak 1.870 ton dengan frekuensi pemesanan sebanyak 216 kali dengan total biaya pembelian bahan baku sebesar Rp. 3.224.558.475. Berdasarkan perhitungan dengan metode EOQ didapatkan untuk kebutuhan bahan baku sebesar 1435 ton frekuensi pemesanan sebanyak 208 kali dengan total biaya sebesar Rp. 3.183.956.876. Dari perhitungan dapat disimpulkan terjadi penghematan bahan baku sebanyak 435 ton, frekuensi pemesanan 8 kali penghematan Rp. 40.601.599. persediaan pengaman (Safety Stock) tebu sebanyak 5,89 ton dan titik pemesanan ulang (Reorder Point) tebu sebanyak 5,89 ton.

Page 24 of 28 | Total Record : 272

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