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BERKALA SAINSTEK
Published by Universitas Jember
ISSN : -     EISSN : -     DOI : -
Core Subject : Science, Education, Agriculture,
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemistry Mathematics Physics
Berkala SAINSTEK (BST) merupakan jurnal ilmiah yang memuat artikel hasil penelitian di bidang sains dan teknologi. Secara khusus BST diperuntukan bagi penulis internal mahasiswa Universitas Jember bidang fisika, matematika, biologi, kimia, teknik sipil, teknik mesin, teknik elektro dan sistem informasi. Namun BST juga menerima artikel dari penulis eksternal sepanjang memenuhi kriteria dan dalam lingkup bidang sains dan teknologi.
Arjuna Subject : -
Articles 254 Documents
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Characterization of Seaweed Caragenan Eucheuma cottonii and Its Aplication as Edible coating Supriwanti, Supriwanti; Warsidah, Warsidah; Prayitno, Dwi Imam
BERKALA SAINSTEK Vol 11 No 2 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v11i2.33865

Abstract

Seaweed E. cottonii is carragaenophytes or carrageenan-producing plant. Carrageenan has a functions stabilizer, thickener and gel former, so it can be used as edible coating that can maintain fish quality. Tuna has nutritional content per 100 grams such protein around 25-26.2%; water 69.40%; fat 1.50%; and carbohydrates 0.03%. Tuna filets quickly decompose if proper handling is not carried out, it is necessary to apply edible coating because this edible coating can protect the product from air contamination and can prevent microbial growth. This study aims to determine the effect of extraction time characteristics of carrageenan and the appropriate concentration of carrageenan for edilbe coating tuna filet. The extraction process was carried out by heating dried seaweed samples with 8% KOH solution for 1 hour, 2 hours and 3 hours at a temperature of 50˚C. The best characteristics of carrageenan resulted from 2 hours of extraction time with 40% yield, 14.95% water content, 63 dPas viscosity and 12.396 ppm sulfate content. The best carrageenan was applied as edible coating on tuna filets with 3 concentrations, namely 1.5%, 2% and 2.5%, each of which was added with 2 mL of glycerol. Based on the Total Plate Count (TPC), it was found that a carrageenan concentration of 2.5% could prevent bacterial growth in the sample as indicated by the TPC number obtained at 2.7×106, which was lower than the control, which was 1.7×107.
Estimating The Distribution of Sea Water Intrusion in Sengkubang Village Based on The Resistivity Value Maulia, Nasya Putri; Muhardi, Muhardi; Perdhana, Radhitya
BERKALA SAINSTEK Vol 11 No 2 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v11i2.36686

Abstract

The fulfillment of clean water needs in Sengkubang Village is done by utilizing groundwater, which in some locations still has a brackish to salty. This situation is one indication of seawater intrusion into groundwater because Sengkubang Village is a coastal area. This study aims to estimate the distribution of seawater intrusion based on the subsurface resistivity value. The method used is the resistivity method with dipole-dipole configuration. Measurements in the field apply six lines with a length of 55 m and the smallest electrode distance of 5 m. The distance of each line from the coastline is approximately 410 m, 485 m, 560 m, 635 m, 710 m, and 785 m. The interpretation results show that the seawater intrusion at the study area has a resistivity value of 0.223 Ωm - 5.03 Ωm at a depth of 0.854 m to 10.9 m. The subsurface layer at the study site is composed of sand, sandy clay, and gravel sand mixed with silt. The unconfined aquifer layer, which is interpreted as sand, is thought to have experienced seawater intrusion to 785 m from the coastline.
An Investigation into the Effectiveness of Green Betel (Piper betle L.) Leaf Extract Hand Sanitizer Yahya, Diyas Aledya; Permatasari, Intan; Ma'mun, Sholeh
BERKALA SAINSTEK Vol 11 No 2 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v11i2.39190

Abstract

Green betel (Piper betle L.) leaf contains anti-thrush, anti-cough, astringent, and antiseptic chemicals such as saponins, flavonoids, polyphenols, and essential oils. Hand sanitizer can also be used as an antiseptic agent, which is a more practical option. The purpose of this study was to see how the composition of green betel leaf extract made by infusion affected its physical properties and bacterial inhibition. Hand sanitizer samples were made using different concentrations of green betel leaf extract (10 - 25 wt%) with and without the addition of tea tree essential oil. Sample testing included organoleptic tests, physical properties tests, and effectiveness tests on the growth of Escherichia coli bacteria. The results showed that the best composition was found to be at a concentration of 10 wt% green betel leaf extract without the addition of essential oil, with pH ranging from 5.2 to 5.8 and viscosities ranging from 1.32 to 1.99 cps, in the form of a watery gel and a clear yellow color. Meanwhile, hand sanitizer sensitivity testing revealed that none of the samples could inhibit the growth of Escherichia coli bacteria. This indicates that the concentration of green betel leaf extract in the sample is still insufficient to inhibit bacterial growth.
Synthesis Zeolite Y From Lapindo Mud With Variations Filling Autoclave And Ratio Molar Si/Al Andarini, Novita; Maziyyah, Deys Sya’fatul; Haryati, Tanti; Sulistiyo, Yudi Aris; Suwardiyanto, S.
BERKALA SAINSTEK Vol 11 No 3 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v11i3.39422

Abstract

Lapindo mud contains Silicate (SiO2), and Aluminum oxide (Al2O3) that can be utilized to synthesize zeolite Y. Zeolite Y was synthesized from Lapindo mud via the smelting and hydrothermal method, respectively. The thermal activation of Lapindo mud was achieved by leaching smelting at 550oC for 2 hours with NaOH to achieve thed desire adding SiO2, NaOH and aging for 48 hours. The effects of various parameters on the synthesis were investigated. The samples were characterized with X-ray Fluorescence (XRF), X-Ray Diffraction (XRD), Fourier Transformation Infrared Spectroscopy (FTIR) and Gas Sorption Analyzer (GSA). Zeolite Y with high crystallinity was synthesized under optimized conditions, such as filling autoclave 90% and a SiO2/ Al2O3 molar ratio of 15.
Co(II)-TiO2/Ti Thin Film as Antibacterial Photocatalysts Escherichia Coli Under Visible Light Ilumination Aritonang, Anthoni Batahan; Rozaqina, Nuri; Harlia, H.
BERKALA SAINSTEK Vol 11 No 3 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v11i3.38055

Abstract

A thin layer of TiO2 doped with Cobalt (II) immobilized on the surface of a titanium foil (Co(II)-TiO2/Ti) has been synthesized from a titanium foil (Ti) as a TiO2 precursor as well as a thin layer matrix and CoCl2.6H2O as a source of Co(II) on variations of 0.5%, 1% and 2%. Synthesis was carried out by anodizing method using ethylene glycol electrolyte solution with the addition of NH4F and followed by calcination treatment at 450ºC for 3 hours. The obtained Co(II)-TiO2 /Ti thin films were characterized using Fourier-transform infrared (FT-IR) spectroscopy, Diffuse Reflectance UV-Vis (DRSUV-Vis) and X-ray diffraction (XRD) methods. Doping Co(II) variations of 0.5%, 1.0% dan 2.0% in the TiO2 structure causes a shift in the vibrational absorption peak of Ti-O (460.99 cm-1) towards a smaller wave number of 459.06 cm-1 respectively ; 453.27 cm-1 and 451.34 cm-1. This is supported by the results of the DRUV-Vis analysis using the tauc plot method, which shows a decrease in the band gap energy of TiO2 (3.24 eV) to 2.57 eV, 2.47 eV and 2.28 eV. Based on XRD analysis, it is known that the Co(II)-TiO2/Ti photocatalyst has anatase phase with a crystal size of 15-17 nm. The photocatalytic activity of Co(II)-TiO2/Ti under visible light illumination was evaluated for inhibition of Escherichia coli bacterial growth. Co(II)-TiO2/Ti photocatalyst at 2.0% Co(II) concentration had the best inhibition (43.2%) compared to 0.5% and 1.0% Co(II) concentrations, respectively 18% inhibition and 27%.
Potential of Reduction Solid Waste from Office Building (Case Study: Gedung Polda Jambi) Laura, Winny; Galih, Ira; Lovena, Anri
BERKALA SAINSTEK Vol 11 No 3 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v11i3.36679

Abstract

Solid waste management in building can be managed with the waste management policy and waste management practice tools. It is contained in the concept of green building. The purpose of this study was to analyze the potential reduce of solid waste in office buildings which is managed by waste management policy and waste management practice tools, and provide scheme recommendations for solid waste management for office buildings the object of this study is Jambi Regional Police Office Building. The methodology was a survey method with solid waste sampling (SNI 19-3964-1994) in Building A, Building B, Canteen and Garden Area and Parking The sampling did for 8 days. Quantitative and quantitative parameters were obtained from the calculation of the generation and composition of solid waste, and also interviews. The results for the generation of solid waste on Jambi Regional Police Office Building: 40.40 kg/day or 0.027 kg/person.day (consist of 45% organic, 28% inorganic, 26% paper and B3 0.7% and others 0.3%). Recommendations scheme can be given for solid waste management in the form of the application of waste management practice tools are started from modification of the waste into separate, collection is done as often as possible, solid waste treatment is done composting and sales to waste banks. The potential for reducing solid waste if the waste management policy and practice tools are applied is 85.64% to 5.8 kg/day.
Utilization of Bendrat Wire fiber on the Mechanical Properties of Geopolymer Concrete Sucahyo, Septian Gusti; Nurtanto, Dwi; Utami, Nanin Meyfa
BERKALA SAINSTEK Vol 11 No 3 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v11i3.38163

Abstract

One of the problems in the construction field, especially concrete, is to reduce cracking due to the brittle nature of the concrete itself and increase the strength of the concrete. One of the ingredients to minimize cracks in concrete is the addition of fiber in the concrete mixture. Therefore, additional innovation is needed in the manufacture of concrete. So, this research was carried out by discussing the use of bendrat wire on the mechanical properties of geopolymer concrete. This study aims to determine the results of compressive strength, split tensile strength, and flexural strength with variations in the addition of 0%, 6%, 12%, and 18% were using a 2% superplasticizer with a concrete age of 28 days. The addition of bendrat wire from 0%, 6%, 12%, and 18% of the test results has increased. For compressive strength, respectively, 40.34 MP, 40.552 Mpa, 40.977 Mpa, and 41.189 MPa. For the splitting tensile strength result, which is 2.07 MPa;, 2.123 MPa, 2.176 MPa, and 2.229 MPa. For flexural strength, 4.05 Mpa, 4.09 Mpa, 4.16 Mpa, and 4.25 MPa.
Comparison of Online and Offline Learning During The COVID-19 Pandemic using Naïve Bayes Method and C4.5 Aulia, Andini Cahya; Fatekurohman, Mohamat; Tirta, I Made
BERKALA SAINSTEK Vol 11 No 3 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v11i3.31737

Abstract

Learning is a process of interaction between educators and students who meet the elements of learning carried out in an educational environment, so that learning can develop student’s abilities, interests and talents optimally. In today's era learning is done online and inversely with offline. The purpose of this study is to analyze the comparison of percentages and classification results as well as the results of learning evaluations using the Naïve Bayes method and C4.5. This test is carried out with 4 variables and a comparison of the two methods. The results showed that the accuracy of Naïve Bayes was 74.07% and C4.5. of 77.77% so that the comparison results show that the level of accuracy of the C4.5 method is better than Naïve Bayes. The resulting importance variables are time and effectiveness as well as the results of the classification of learning decisions, namely the offline category as many as 16 data on the Naïve Bayes method and 19 data on the Decision Tree algorithm C4.5 method from 27 input testing data.
Cover BST Volume 11 No 3 (2023) BERKALA SAINSTEK, Jurnal
BERKALA SAINSTEK Vol 11 No 3 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Production of Photosynthetic Pigments from Spirulina platensis Under Different Light Intensities Kusumaningtyas, Pintaka; Gultom, Sihol Dwijaya; Usman, U.
BERKALA SAINSTEK Vol 11 No 3 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v11i3.38474

Abstract

Photosynthetic pigments from microalgae have great potential biotechnological applications, as healthy food colorants and cosmetics. The production of photosynthetic pigments depends on many environmental conditions, mainly light intensity during the cultivation period. The present study aimed to determine the productivity of photosynthetic pigments in the biomass of S. platensis, including total chlorophylls, carotenoids, and phycocyanin, under different light intensities: 40 µmol m–2 s–1 (lower light intensity) and 70 µmol m–2 s–1 (higher light intensity). The results showed that S. platensis culture responds to changes in light intensity by changing the composition of photosynthetic pigments as an adaptive mechanism. The higher carotenoids content (69.69 ± 7.47 µg/g dw) was found under high light intensity, meanwhile, the higher chlorophyll (1495.47 ± 279.00 µg/g dw) and phycocyanin (4995.49 ± 576.52 µg/g dw) contents were observed under low light intensity. The highest productivity of photosynthetic pigments in S. platensis was shown by phycocyanin (318.86 ± 44.22 µg/L/day) and cholophylls (95.38 ± 19.35 µg/L/day) which were produced under low light intensity. Our results show that changes in light intensity can contribute to a stronger effect on the productivity of algal pigments for human health benefits and food colorants.

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