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All Journal Jurnal Ilmu Dasar BERKALA SAINSTEK Pelita Perkebunan UNEJ e-Proceeding ALCHEMY Jurnal Penelitian Kimia J-Dinamika: Jurnal Pengabdian Kepada Masyarakat Social, Humanities, and Educational Studies (SHEs): Conference Series Jurnal Pengabdian Masyarakat IPTEKS JIIP (Jurnal Ilmiah Ilmu Pendidikan) Computational and Experimental Research in Materials and Renewable Energy (CERiMRE) JOLLT Journal of Languages and Language Teaching Journal of Agriculture and Applied Biology Journal of Agriculture and Applied Biology ( JAAB) Studies in English Language and Education Indonesian Chimica Letters InSTEM al Kimiya : Jurnal Ilmu Kimia dan Terapan Jurnal Ilmiah Bisnis, Manajemen, dan Akuntansi
Dwi Indarti
Jurusan Kimia Fakultas MIPA, Universitas Jember
Religion Agriculture, Biological Sciences & Forestry Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Economics, Econometrics & Finance Education Energy Environmental Science Languange, Linguistic, Communication & Media Materials Science & Nanotechnology Mathematics Physics Social Sciences Other

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Pengaruh Variasi Waktu Penguapan Terhadap Kinerja Membran Selulosa Asetat pada Proses Ultrafiltrasi Amiyati, Dewi Rara; Indarti, Dwi; Muflihah, Yeni Maulidah
BERKALA SAINSTEK Vol 5 No 1 (2017)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v5i1.5368

Abstract

Penelitian ini mempelajari pengaruh variasi waktu penguapan terhadap kinerja membran selulosa asetat. Pada proses ultrafiltrasi, selulosa asetat dibuat dengan menambahkan polietilen glikol (PEG) sebagai agen pembentuk pori membran dan meningkatkan nilai fluks membran. Pembuatan membran selulosa asetat dilakukan dengan metode inversi fasa. Variasi waktu penguapan yang digunakan selama 0, 1, 3, dan 5 menit. Membran selulosa asetat yang terbentuk dikarakterisasi meliputi uji porositas, fluks dan rejeksi. Hasil penelitian menunjukkan waktu penguapan selama 5 menit menghasilkan membran yang lebih rapat. Hasil pengukuran porositas, fluks dan rejeksi terhadap dekstran 500 kDa berturut-turut sebagai berikut: 53,35%; 4,078 (L/jam.m2) dan 92,917%. Kata Kunci: Porositas, Selulosa Asetat,Waktu Penguapan.
Padsorpsi Cu2+ Menggunakan Kitosan Beads Termodifikasi Formaldehida Kristi, Maganda Ananda; Indarti, Dwi; Mulyono, Tri
BERKALA SAINSTEK Vol 5 No 2 (2017)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v5i2.5555

Abstract

Penelitian ini bertujuan untuk memodifikasi kitosan beads yang termodifikasi dengan formaldehida untuk meningkatkan ketahanannya. Perbandingan NaCl dengan kitosan adalah sebesar 1:1 (g/g). Variasi formaldehida yang digunakan adalah 23%, 30% dan 37%. Kitosan beads digunakan untuk mengkaji kapasitas adsorpsi dan porositas. Berdasarkan hasil penelitian, waktu optimum adsorpsi pada waktu 120 – 180 menit. Kapasitas adsorpsi ditentukan menggunakan isoterm Langmuir. Penambahan formaldehida pada kitosan beads mengakibatkan kapasitas adsorpsi dan porositas beads menurun. Hasil spektrum IR menunjukkan perubahan puncak pada daerah bilangan gelombang 1548 - 1660 cm -1. Spektrum IR tersebut membuktikan bahwa adanya perubahan gugus amina primer menjadi amina sekunder setelah ditambahkan formaldehida.Kata Kunci: Adsorpsi, Beads, Formaldehida, Ikat Silang, Porositas.
Performance of cotton fabric treated with chitosan-based mordanty as affected by extraction time variations on tannin dyes produced from cocoa husk Fatwa, Muhammad Iqbal; Firmanto, Hendy; Indarti, Dwi; Piluharto, Bambang; Sulistyo, Yudi Aris; Reza, Muhammad; Ula, Mohammad Munal; Dharmawan, Aditya Dwiki
Pelita Perkebunan (a Coffee and Cocoa Research Journal) Vol. 40 No. 1 (2024)
Publisher : Indonesian Coffee and Cocoa Research Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22302/iccri.jur.pelitaperkebunan.v40i1.584

Abstract

Natural dyes are substances obtained from animals or plants through extraction. The application of synthetic dyes can affect to environmental problems, therefore replace it with natural dyes is become an alternative. Cocoa pod husk still considered as a waste, whereas it is one of source for natural dyes. Cacao pod husk contains flavonoids, tannins, and β-carotene compounds which is generate colour. Natural dye is extracted from the husk of the cocoa pod and applied to cotton cloth. Extraction of cocoa husk dyes was carried out with distilled water at 60˚C with variations of 1, 2, and 3 hours. The resulting extract contains positive tannins but negative β-carotene. Variations in the extraction time of natural dyes affect the tannin content extracted. The tannin content extracted with variations of 1, 2, and 3 hours was 18.32; 18.67; and 17.93 ppm. Respectively chitosan-based mordant has a significant effect on the color yield of the fabric. Fabrics with mordant have a darker color than fabrics that are not applied with mordant process. The use of nanochitosan and citric acid crosslinkers can maintain the aging color of the fabric. The FTIR results on the fabric showed that color aging occurred due to the presence of ester groups formed between chitosan and dyes. Chitosan-based mordant coating provides better color than without mordant coating. Fabrics coated with chitosan had the best fastness value of 4 (Good).
Synthesis and Characterization of Glutaraldehyde-Crosslinked Chitosan for Urea Controlled Release Piluharto, Bambang; Indarti, Dwi; Handoko, Donatus Setyawan Purwo; Ananda, Tinok Dwi
Indonesian Chimica Letters Vol. 3 No. 2 (2024)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/icl.v3i2.4325

Abstract

Urea exhibits high nitrogen content (∼46%), which is essential for plant growth. However, significant nitrogen losses occur through decomposition, leaching, denitrification, and volatilization. Employing controlled-release systems, such as chitosan membranes crosslinked with glutaraldehyde, can mitigate these losses and enhance fertilizer efficiency. Therefore, this study aimed to develop and characterize chitosan-glutaraldehyde membranes as controlled-release fertilizer systems for urea. Chitosan membranes were crosslinked with varying glutaraldehyde concentrations (0%, 0.4%, 0.9%, 1.3%, and 1.8%) and used to encapsulate urea. The membrane produced was characterized using FTIR and swelling degree assay. The potency of glutaraldehyde-crosslinked chitosan as a urea coating agent was also studied spectrophotometrically using the Nessler reagent. FTIR analysis revealed low intensity of the C=N stretching vibration, indicating limited crosslinking reaction. Additionally, both swelling degree and urea release increased proportionally with increasing glutaraldehyde concentration. These findings suggest limited crosslinking reactions occurred between glutaraldehyde and chitosan within the studied concentration range.
Pengaruh Kinerja Keuangan terhadap Penghindaran Pajak di Perusahaan Tambang yang Terdaftar di BEI (Studi Kasus Perusahaan Tambang pada Tahun 2016-2020) Indarti, Dwi; Bambang Ahmad Indarto; Fitri Dwi Jayanti
Jibaku: Jurnal Ilmiah Bisnis, Manajemen dan Akuntansi Vol. 3 No. 2 (2023): Juli
Publisher : Universitas Ngudi Waluyo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35473/jibaku.v3i2.2443

Abstract

Many cases of tax avoidance are often carried out by large companies in Indonesia which are very detrimental to state revenues. One of them is the mining sector company which is the fourth largest tax contributor in Indonesia. The purpose of this study is to determine the effect of return on assets, leverage and capital intensity on tax avoidance. This study uses quantitative research methods and uses secondary data in the form of the company's annual financial reports. The population in this study were all mining sector companies listed on the Indonesia Stock Exchange (IDX) from 2016 to 2020. The sample used in this study used the purposive sampling method to obtain 20 companies during the observation period of 5 consecutive years, so that 100 samples were obtained. The results of this study indicate that return on asset has a significant effect on tax evasion. Leverage has no significant effect on tax avoidance. Capital intensity has no significant effect on tax avoidance. Abstrak Banyak kasus penghindaran pajak kerap dilakukan oleh perusahaan-perusahaan besar di Indonesia yang sangat merugikan bagi penerimaan negara. Salah satunya yaitu perusahaan sektor pertambangan yang menjadi penyumbang pajak terbesar keempat di Indonesia. Tujuan dari penelitian ini yaitu untuk mengetahui pengaruh return on asset, leverage dan intensitas modal terhadap penghindaran pajak. Penelitian ini menggunakan metode penelitian kuantitatif dan menggunakan data sekunder berupa laporan keuangan tahunan perusahaan. Populasi pada penelitian ini adalah seluruh perusahaan sektor pertambangan yang terdaftar di Bursa Efek Indonesia (BEI) tahun 2016 hingga 2020. Sampel yang digunakan pada penelitian ini menggunakan metode purposive sampling didapat 20 perusahaan selama periode pengamatan 5 tahun berturut-turut, sehingga didapat 100 sampel. Hasil penelitian ini menunjukkan bahwa return on asset berpengaruh signifikan terhadap penghindaran pajak. Leverage tidak berpengaruh signifikan terhadap peng
Language Attitudes and Valorization Among Indonesianan Engineering Students Nurlia, Vera; Indarti, Dwi; Manara, Christine
Journal of Languages and Language Teaching Vol 13, No 1 (2025)
Publisher : Universitas Pendidikan Mandalika

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33394/jollt.v13i1.13290

Abstract

This study explores the attitudes and valorization of languages among Indonesian engineering students at Cendikia Abditama University. Employing a qualitative research design, the study gathered data from 70 students through questionnaires, supplemented by in-depth interviews with 10 participants to gain richer perspectives. A descriptive analytical approach was used to interpret the findings, revealing a predominantly positive attitude toward English, Indonesian, and heritage languages. This demonstrates a nuanced balance between cultural pride, national identity, and the global opportunities associated with these languages. The research highlights that while many students value all three languages equally, others exhibit a preference for one language over the others, depending on their immediate academic, professional, or personal aspirations. These variations reflect the dynamic interplay between cultural heritage and global competitiveness in shaping language attitudes. The findings underline the critical role of educational policies in supporting linguistic diversity and fostering inclusive learning environments. By integrating students’ linguistic backgrounds into educational curricula, institutions can enhance learning experiences and promote multilingual competence. Such approaches can help prepare students for the challenges of a globalized world while maintaining their cultural roots, thereby contributing to more comprehensive and meaningful educational practices. This study emphasizes the significance of aligning language education with students' diverse needs and aspirations.
Attitudes toward language and language choice in regional intermarriage families: A case study in Tangerang, Banten Indarti, Dwi; Manara, Christine
Studies in English Language and Education Vol 12, No 1 (2025)
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/siele.v12i1.36436

Abstract

Despite extensive research on language attitudes and shifts in Indonesia, studies on language choice in intercultural marriages remain scarce. Therefore, this study explores the attitudes toward heritage, national and international languages, as well as factors influencing language choice in regional intermarriage families living in Tangerang, Banten. This research employed a qualitative case study and used a purposive sampling technique to select the respondents. The respondents were four mothers whose spouses come from different regional cultural backgrounds and live in the Tangerang area. Using questionnaires and semi-structured interviews, this study revealed positive attitudes toward heritage, national, and international languages among respondents, emphasizing the significance of regional languages as crucial elements in maintaining connections with their cultural roots and fostering a sense of self-awareness and appreciation of their cultural backgrounds. However, discrepancies emerge between the parents beliefs and their actual efforts to maintain and preserve the heritage language for their children. Meanwhile, well-educated female parents perceive mastering English as essential in a globalized world. They prioritize English proficiency to provide educational opportunities for their children. This dual perspective on language reflects an attitude among the respondents that is sensitive to levels of formality and covers diverse purposes of language. On one hand, the desire to learn and use English to connect with the global community indicates an awareness of the importance of a global language for communication, education, and opportunities beyond their local context. On the other hand, their attachment to national and regional languages highlights a strong sense of cultural identity.
Effect of Molecular Weight of Chitosan in The Coating Solutions on The Shelf Life of Tuna Fish Fillets Indarti, Dwi; Khofifah, Marhamatul; Piluharto, Bambang; Ananda, Tinok Dwi
al Kimiya: Jurnal Ilmu Kimia dan Terapan Vol. 12 No. 1 (2025): June 2025
Publisher : Department of Chemistry, Faculty of Science and Technology, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/ak.v12i1.44715

Abstract

Tuna, a valuable Indonesian marine commodity, is known for its highly valued dietary and nutritional sources. However, this red meat fish is particularly prone to deterioration and spoilage due to its inherent properties. Liquid smoking, a popular fish preservation method in Indonesia, has garnered significant consumer interest but remains insufficient to prevent fish decay entirely. Therefore, this study aimed to enhance tuna fish fillet (TFF) shelf life by developing a novel coating solution. This solution contains liquid smoke seasoning and chitosan with varying molecular weights (MW), as this property affects chitosan’s chemical, physical, and biological characteristics. In this research, fresh tuna were divided into four groups: a control group with no coating, a group with liquid smoke coating only (LS), a group coated using chitosan solution (Ch) with variations of MW (Low: 50-190 kDa, Medium: 190-310 kDa, and High: 210-375 kDa), and a group coated using liquid smoke seasoning with the same chitosan MW variation (Ch + LS). During 15 days of storage in the freezer, their chemical properties (pH, and Total Volatile Base Nitrogen - TVB-N) were analyzed. The finding showed that combining high MW of chitosan and liquid smoke as a coating solution improved TFF appearance, maintaining a desirable uniformly cherry red color. Moreover, this treatment showed a slower increase in pH (5.5 – 5.7) and TVB-N level (22 – 28 mg TVB-N/100 gram), indicating deterioration and spoilage delay during 15 days of storage compared to other treatments. This study underscores the efficacy of a preservation strategy in inhibiting deterioration and spoilage in tuna fish fillets during storage, thereby enhancing product quality and ensuring consumer safety.
Toulmin Argument Patterns in Asian EFL Learners' Essays: Gender and Topic-Based Comparison Indarti, Dwi
Journal of Languages and Language Teaching Vol. 13 No. 3 (2025)
Publisher : Universitas Pendidikan Mandalika

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33394/jollt.v13i3.14701

Abstract

This study explores Toulmin Argument Patterns (TAP) in argumentative essays by Asian EFL learners, focusing on gender and topic-based comparison. Using an adapted Toulmin model, it analyses argument components, claims, data, counter-arguments, and rebuttals, from the ICNALE corpus on topics "smoking" and "part-time job". Indonesian female learners constructed higher-quality arguments with comprehensive rebuttals, whereas their male counterparts relied more on basic elements. Among Chinese learners, gender differences were minimal, with both genders showing balanced TAP use, reflecting structured critical-thinking education. Familiar topics like "part-time job" led to more complex arguments, while less relatable topics like "smoking" resulted in weaker argumentation. Cultural factors also influenced argument quality, with Confucian-influenced education fostering consistency among Chinese learners and diverse educational practices leading to variability in Indonesian learners. These insights can inform curriculum design by encouraging the integration of culturally relevant and gender-responsive writing tasks that support students' critical thinking and argumentative skills. Future research should expand to broader linguistic and cultural contexts to refine TAP-based pedagogical strategies and deepen understanding of argumentative competence in EFL settings.
Spectrophotometric Analysis of Caffeine Content in Coffee Mistletoe (Dendrophthoe petandra L.) Apriliana, Gepsa; Indarti, Dwi; Muflihah, Yeni Maulidah
Indonesian Chimica Letters Vol. 2 No. 2 (2023)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/icl.v2i2.5606

Abstract

Caffeine, a well-known alkaloid presents in plants such as tea, coffee, and kola nuts, was thoroughly analyzed in coffee mistletoe. Our study successfully extracted caffeine using dichloromethane and chloroform, incorporating qualitative testing and robust method validation with a visible spectrophotometer. Notably, dichloromethane yielded the highest caffeine extract at 0.042 grams. The qualitative tests distinctly confirmed the presence of caffeine, evidenced by a color change with Parry's reagent and a maximum absorption wavelength of 273 nm. We also pinpointed the caffeine complex’s maximum wavelength at 640 nm, further validating our findings against a standard solution. Our method validation showed impressive linearity (r = 0.9974), with limits of detection at 1.81 ppm and quantitation at 6.02 ppm. The accuracy ranged between 90.0% and 97.5%, while the precision values were consistently around 98%. Additionally, we determined the water content of the coffee mistletoe leaf powder to be 8.733%. This comprehensive analysis establishes a strong foundation for the caffeine content in coffee mistletoe.
Co-Authors A Asnawati Agus Wedi Pratama Ahmad Turidi Amiyati, Dewi Rara Anak Agung Istri Ratnadewi Apriliana, Gepsa Apriliasari, Yekti Asnawati Asnawati Asnawati Asnawati Asnawati Asnawati, A. Badrut Tamam Ibnu Ali Bambang Bambang Ahmad Indarto Bambang Piluharto Bambang Piluharto Busroni, Busroni Christine Manara D. Iwan Setiawan Denny Trias Utomo, Denny Trias Dharmawan, Aditya Dwiki Diah Ayu Nur Sholehah Dwi Jayanti, Denik DWI SURYANTO Eka Surya Buana, Eka Surya Elis Nur Farida, Elis Nur Fatwa, Muhammad Iqbal Fauziyah, Kamelia Rizqi Firmanto, Hendy Fitri Dwi Jayanti Gembong Kesuma B HARDIAN SUSILO ADDY Henry Adi Syahputra Sidabutar Heny Yunita Novianti I Nyoman Adi Winata Ika Oktavianawati Irmawati, Nurisda Eva Khofifah, Marhamatul Komsiyah, Komsiyah Kristi, Maganda Ananda Marahayu, Mustika Muhammad Firdaus Muhammad Reza Nanda Widayanti Neran Neran Novita Andarini Novitasari Novitasari Nurlia, Vera Priza Pandunata Purwatiningsih Purwo Handoko, Donatus Setyawan Putri, Sella August Putri, Sella August Rizqon Rizqon S. Purwo Handoko, Donatus Siti Nur Jannah Siti Rofiqoh, Siti Sudarko Sulistyo, Yudi Aris Sulistyowati, Fitri Tanti Haryati Tinok Dwi Ananda Tri Mulyono Tri Mulyono Ula, Mohammad Munal Wuryanti Handayani Yeni Maulidah Muflihah Yudi Aris Sulistiyo, Yudi Aris Zulfikar Zulfikar