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Tailoring Photocatalytic Activity of Sol-Gel-Derived Bismuth Oxide via Calcination Time Optimization for Methyl Orange Degradation Astuti, Yayuk; Muslim, Agus; Darmawan, Adi
Bulletin of Chemical Reaction Engineering & Catalysis 2026: BCREC Volume 21 Issue 1 Year 2026 (April 2026)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20452

Abstract

Bismuth oxide (Bi2O3) is a yellow solid, has good electrical properties and a wide band gap energy (2-3.96 eV). Therefore, this material is commonly used as a photocatalyst. This study aims to synthesize bismuth oxide using the sol-gel method, determine its physicochemical characteristics and photocatalytic activity in the degradation of methyl orange dyes. Bi2O3 is synthesized from Bi(NO3)3.5H2O which is reacted with citric acid at 100 ° C for 20 hours. The formed gel is then dried and calcined at 600 °C for 1, 2, 3, 4 and 5 hours. The synthesis results in the form of pale-yellow powder with the same crystal system that is a mixture of α-Bi2O3 (monoclinic) and γ-Bi2O3 (BCC) and has almost the same morphology that is similar to coral and has a particle size of 1-8 μm. The results of photocatalytic activity tests showed that the constant rate of degradation reaction of methyl orange by bismuth oxide with calcination time of 1, 2, 3, 4, and 5 hours respectively was 2.76×10-5 s-1, 2.65×10-5 s-1, 2.53×10-5 s-1, 2.81×10-5 s-1 and 3.87×10-5 s-1. Bismuth oxide with a calcination time of 5 hours has the highest photocatalytic activity. Meanwhile, bismuth oxide with a calcination time of 5 hours has a band-gap of 2.86 eV and 2.64 eV. The stages of decomposition of bismuth oxide material with a calcination time of 5 hours consisted of 3 release stages namely H2O, CO2, CxHyOz respectively 12.20%, 5.33% 30.54%. Copyright © 2026 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Pengaruh Gaya Kepemimpinan Terhadap Profsionalisme Aparatur Sipil Negara Di Kelurahan Kadidi Irman, Iriani; Muh. Rohady Ramadhan; Yayuk Astuti
Jurnal Administrasi Politik dan Sosial Vol 6 No 3 (2025): JAPS Desember 2025
Publisher : Fakultas Ilmu Sosial dan Ilmu Politik, Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46730/japs.v6i3.329

Abstract

Penelitian ini bertujuan menganalisis Pengaruh Gaya Kepemimpinana Lurah Terhadap Profesionalisme Aparatur Sipil Negara di kelurahan kadidi menjadi ,kabupaten sidenreng rappang menjadi lokasi dalam penelitian ini. Latar penelitian ini di dasarkan padpentingnya peran ASN pada pelayanan publik yang berkualitas,serta signifikan pemimpin dalam membentuk kinrja dan etos kerja pegawai.Penelitian ini menggunakan pendekatan kuantitatif dengan metode penelitian kausal komparatif .Tekni pengumpulan data dilakukan melalui koesioner dan wawancara yang terdiri dari 85 responden yang terdiri dari ASN ,non ASNdan masyarakat.Variabek independen dalam penelitian ini yakni Gaya Kepemimpinan ,sedangkan variabel dependen yakni Profesionalisme ASN.Hasil penelitian ini menunjukkan bahwa Gaya Kepemimpinan yang di terapkan di kelurahan kadidi masuk pada kategori “Baik” dengan rata-rata persentase 55%. Gaya kepemimpinan Demokratis menempati skor tertinggi sebesar 65%,di ikuti oleh Gaya Transaksional 64%.Sementara itu Tingkat Profesionalisme ASN tergolong baik,di tunjukkan dengan indikator Kualitas Pelayan dengan persentase tertinggi 69%.Analisi Regresi Linear Sederhana menunjukkan bahwa terdapat pengaruh signifikan terhadap Gya Kepemimpina terhadap Profesionalisme ASN.Dengan demikian, pemilihan dan penerapan gaya kepemimpinan yang tepat,khususnya gaya demokratis dan transaksional,dapat meningkatkan profesionalisme ASN dalam menjalankan tugas pemerontahan dan pelayanan publik.
PENGARUH FINANCIAL TECHNOLOGY LENDING TERHADAP PERTUMBUHAN EKONOMI DI PROVINSI KALIMANTAN TIMUR: PENGARUH FINANCIAL TECHNOLOGY LENDING TERHADAP PERTUMBUHAN EKONOMI DI PROVINSI KALIMANTAN TIMUR Astuti, Yayuk
ECO-BUILD Economy Bring Ultimate Information All About Development Journal
Publisher : Prodi Ekonomi Pembangunan, Universitas Muhammadiyah Berau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35915/ej.v7i1.807

Abstract

This study aims to examines the effect of financial technology lending on economic growth in the province of East Kalimantan, the type of data collected is quantitative data on economic growth in the Province of East Kalimantan which is available on the website of the Central Bureau of Statistics in the Province of East Kalimantan and financial technology lending data available on the website of the Financial Services Authority. The analytical method used in this study is classical assumption test analysis, simple regression, coefficient of determination, correlation coefficient, and t-test. The results of the study show that financial technology lending has a positive effect on economic growth in the Province of East Kalimantan. The correlation coefficient of 33.4 percent indicates a effect between financial technology lending and economic growth but not significantly.
Hubungan Tata Letak Dapur (Kitchen Layout) Terhadap Produktivitas Kerja Karyawan Di Senja Cafe & Resto Rasman; Hartati; Yayuk Astuti; Yusrianti
Pendas : Jurnal Ilmiah Pendidikan Dasar Vol. 11 No. 01 (2026): Volume 11 No. 01 Maret 2026 Public
Publisher : Program Studi Pendidikan Guru Sekolah Dasar FKIP Universitas Pasundan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23969/jp.v11i01.42421

Abstract

This study aims to analyze the relationship between kitchen layout and the level of employee work productivity at Senja Café & Resto. The research is motivated by the importance of kitchen spatial design in supporting the smooth operation of restaurant activities. Inappropriate space arrangement, inefficient equipment placement, and unstructured workflow have the potential to hinder performance and increase employees’ physical workload.This study employed a quantitative approach with a correlational research design to determine the relationship between kitchen layout as the primary factor under investigation and employee productivity as the observed outcome. Data were collected through questionnaires and direct observation involving all 15 kitchen employees. After the research instruments were confirmed to be valid and reliable, the data were analyzed using descriptive statistics and the Spearman Rank correlation test.The findings reveal a positive and significant relationship between a well-organized kitchen layout and increased employee productivity. An ergonomic kitchen design, balanced distances between work areas, and a well-structured workflow were proven to help accelerate task completion, reduce fatigue, and create a more comfortable working environment. Conversely, poorly planned layouts and limited movement space may decrease employee work effectiveness.Therefore, improving the kitchen layout can serve as an effective strategy for management to enhance operational efficiency, speed up customer service processes, and strengthen business competitiveness. Furthermore, this study is expected to serve as a practical reference for medium-scale culinary businesses in managing kitchens in a more structured, efficient, and ergonomically oriented manner. Keywords: kitchen layout, work productivity, ergonomics, employees, culinary business.
Digital Public Leadership dalam Komunikasi Kebijakan Publik Analisis Konten Instagram Bupati Sidenreng Rappang Ibrahim, Abdul Gafur; Yayuk Astuti
Jurnal Administrasi Publik dan Pemerintahan Vol. 5 No. 1 (2026): SIMBOL : Jurnal Administrasi Publik dan Pemerintahan
Publisher : LPPM STISIP IMAM BONJOL

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55850/simbol.v5i1.408

Abstract

This study employs a qualitative approach using content analysis to examine leadership communication patterns on social media. The unit of analysis consists of 40 Instagram posts published after the regent’s inauguration in 2025. Data were collected through documentation of Instagram posts and analyzed using a coding scheme based on four leadership communication categories: administrative leadership, public service leadership, collaborative governance, and symbolic leadership. The findings show that administrative leadership content dominates the communication pattern with a proportion of 30 percent, followed by public service leadership (25 percent), symbolic leadership (25 percent), and collaborative governance (20 percent). These results indicate that Instagram is mainly used as a platform to display governmental activities and administrative leadership. However, the communication pattern remains largely one-directional, focusing more on information dissemination rather than interactive engagement with citizens. This study contributes to public administration literature by highlighting the role of social media in shaping digital public leadership in local government.
Digitalization of Police Services as Public Service Innovation: A Case Study of the Parepare Police Ahmad, Jamaluddin; Nurjannah Nonci; Zainuddin, Abdul Majid; Astuti, Yayuk; Gafur, Abdul
Journal of Local Government Issues Vol. 9 No. 1 (2026): March
Publisher : Universitas Muhammadiyah Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22219/logos.v9i1.43348

Abstract

This study investigates the digitalization of police services through the Polri Super App at the Parepare Police Department, focusing on efficiency, accessibility barriers, accountability and transparency, and institutional challenges. The research aims to analyze how digital policing contributes to more efficient and accountable service delivery while also identifying the limitations constraining its implementation. Using a qualitative case study approach, data were collected through in-depth interviews, observations, and document analysis. They were processed using NVivo software to generate thematic coding, word frequency visualization, and a matrix coding query. The findings reveal that the application significantly improved efficiency by reducing waiting times and streamlining administrative processes. It also enhanced accountability through digital trails that minimized manipulation and unofficial payments. However, the study highlights persistent barriers, particularly for older citizens with limited digital literacy, as well as institutional challenges such as inadequate staff training and frequent system downtime. From a theoretical standpoint, the results confirm the relevance of the Technology Acceptance Model (TAM) and the Unified Theory of Acceptance and Use of Technology (UTAUT). At the same time, the New Public Service (NPS) framework emphasizes the importance of accountability and inclusivity in digital reforms.
The Characterization of Oyster Shell (Crassostrea gigas) as Adsorbent in The Removal of Cr(VI) Ions. A Study of NaOH and H2SO4 Activation Effect Lia Handayani; Cut Rahmawati; Nurhayati Nurhayati; Yayuk Astuti; Adi Darmawan
Elkawnie Vol. 6 No. 1 (2020)
Publisher : Faculty of Science and Technology Universitas Islam Negeri Ar-Raniry

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22373/ekw.v6i1.5543

Abstract

Abstract : Oyster shell as one of the highest bio-waste in Alue Naga Aceh Besar District, Indonesia, was used as an adsorbent to remove a heavy metal Cr (VI) ion. The study was started by calcinating oyster shells at a high temperature of 800 ºC for 3 hours. The effect of various acid (H2SO4) and base (NaOH) activator was studied using characterization and adsorption experiments. The characterization obtained the sample activated by 10% NaOH (Na10-ACT) and 10% H2SO4 (H10-ACT) had the highest surface area which had 14.23 m2/g, 10.77 m2/g, respectively. Furthermore, the adsorption experiments confirmed the highest surface area by showing the highest Cr (IV) ion removal of 57.66%, 70.7%, respectively. The further investigation using X-ray fluorescence (XRF) determined that the Na10-ACT adsorbent has a better composition compared to the H10-ACT due to its high purities.Abstrak : Cangkang tiram sebagai salah satu bio-limbah padat di Desa Alue Naga Kabupaten Aceh Besar, digunakan sebagai adsorben untuk menghilangkan ion logam berat Cr (IV). Penelitian ini diawali dengan mengkalsinasi cangkang tiram pada temperatur tinggi 800ºC selama tiga jam. Pengaruh penambahan aktivator asam (H2SO4) dan basa (NaOH) juga dipelajari melalui karakterisasi dan pengujian adsorpsi. Hasil karakterisasi menunjukkan sampel yang diaktivasi dengan 10% NaOH (Na10-ACT) dan 10% H2SO4 (H10-ACT) memiliki luas permukaan tertinggi yaitu 14,23 m2/g, 10,77 m2/g, masing-masing. Lebih lanjut, pengujian adsorpsi juga mendukung luas permukaan yang tinggi dengan menghilangkan ion Cr (IV) sebesar 57,66%, 70,7%, masing-masing. Investigasi melalui analisa XRF menyimpulkan bahwa Na10-ACT memiliki komposisi yang lebih baik dibanding H10-ACT karena memiliki kemurnian yang tinggi.
Production and Characterization of Adsorbent from Oyster Shell (Crassostrea gigas) Using Physics and Chemical Activation with ZnCl2 and Its Application for Removal of Hexavalent Chromium Lia Handayani; Azwar Thaib; Nurhayati Nurhayati; Yayuk Astuti; Adi Darmawan
Elkawnie Vol. 6 No. 2 (2020)
Publisher : Faculty of Science and Technology Universitas Islam Negeri Ar-Raniry

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22373/ekw.v6i2.7333

Abstract

Abstract: Oyster shell waste has been investigated as a raw material for making adsorbents that will be activated. Physical activation uses temperatures of 500 ºC, 600 ºC, 700 ºC, 800 ºC, 900 ºC and chemical activation uses ZnCl2 with a concentration of 1 %, 5 %, 10 % and 15 %. Based on the analysis of the characteristics that have been carried out for physically activated adsorbents, the oyster shell calcined at 800 ºC produces the best characteristics, it is a radius of 35.11 Å with a percentage of removal of 38.04 %, as well as the results of the FTIR, XRF and SEM analysis gives the best results among others. Whereas for chemically activated adsorbents, the use of activator ZnCl2 10% produces adsorbents with the best characteristics among others with a radius of 84.14 Å and removal percentage of 65.68 %, the best results for adsorbents activated using 10% ZnCl2 are also supported by analysis results given by FTIR, XRF, and SEM.Keywords: Adsorbent; BET; Cr6+; Oyster Shell Waste; XRF Abstrak: Cangkang tiram (Crassostrea gigas) telah diteliti sebagai bahan baku pembuatan adsorben yang akan diaktivasi secara fisika dan kimia. Pembuatan adsorben dengan aktivasi secara fisika menggunakan variasi suhu 500 ºC, 600 ºC, 700 ºC, 800 ºC dan 900 ºC. sedangkan aktivasi kimia yaitu menggunakan aktivator ZnCl2 menggunakan variasi konsentrasi 1 %, 5 %, 10% dan 15 %. Berdasarkan analisa karakteristik yang telah dilakukan untuk adsorben-adsorben yang telah diaktivasi secara fisika, cangkang tiram yang di kalsinasi pada suhu 800ºC menghasilkan karakteristik yang paling baik, yaitu radius pori-pori 35,11 Å dengan persentase penyisihan sebesar 38,04 %, begitu pula dengan hasil analisa FTIR, XRF dan SEM memberikan hasil terbaik diantara yang lain. sedangkan untuk adsorben-adsorben yang diaktivasi secara kimia, penggunaan aktivator ZnCl2 10% menghasilkan adsorben dengan karakteristik yang paling baik diantara lainnya dengan radius pori-pori 84,14 Å dan persentase penyisihan sebesar 65,68%, hasil terbaik untuk adsorben yang diaktivasi menggunakan ZnCl2 10 % juga didukung oleh hasil analisa dari FTIR, XRF dan SEM.
Product Differentiation Strategy at Nhanas Donuts Pinrang in Facing Culinary Business Competition in the Millennial and Gen Z Era Kurniawaty; Yusrianti; Trisnasari, Damayanti; Astuti, Yayuk
Economics and Business Journal (ECBIS) Vol. 4 No. 4 (2026): May
Publisher : PT. Maju Malaqbi Makkarana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.47353/ecbis.v4i4.321

Abstract

This study aims to analyze the product differentiation strategy implemented by Nhanas Donuts Pinrang in facing culinary business competition in the millennial and Gen Z era. The research method used is descriptive qualitative with data collection techniques through interviews, observation, and documentation. Informants consisted of the owner, production and service employees, as well as millennial and Gen Z consumers. The results showed that the product differentiation strategy applied includes four main aspects: flavor innovation with contemporary variants (matcha cheese, red velvet crumble, cookies and cream), attractive and "instagrammable" visual display, aesthetic and modern packaging design, as well as active digital marketing through Instagram, Facebook, and TikTok. Supporting factors for the success of differentiation include the owner's creativity, understanding of young consumer behavior, strategic location, and digital branding. The implications of this study indicate that product differentiation integrated with digital marketing is able to increase competitiveness and customer loyalty of local culinary Micro, Small, and Medium Enterprises in the digital era.
Co-Authors Abdul Gafur Abdul Jabbar Adi Darmawan ADI SANTOSO Agriccia Pangestica Saputry Ahmad Suseno Alfi Saadah Alfiansyah Alfiansyah Amilia Fauziyah Anisyah Anisyah Annisa Syifaurrahma Arnelli Arnelli Arum Dista Wulansari Aulia Zahra Ekaningsih Azwar Thaib Bara Yunianto Fathoni Brainy Happy Ana Tasiman Brainy Happy Ana Tasiman Brigita Maria Listyani Cut Rahmawati Daniswara, Lufthansyah Dayadi, Dayadi Didi Dwi Anggoro Didik Setyo Widodo Esti Ayu Faisal Syahputra Fandi Nasrun Cholis Faradina Azahra Zaqia Fauzan Musthafa Febrianti, Devi Fitriani Solichah Galih N. R. Pargiman Gaurav A. Bhaduri Gunawan Gunawan HARTATI Hartati Hartati Hasim Muzadi Hendri Widiyandari Hendri Widiyandari Hendri Widyandari Husnayani, Husnayani Ibrahim, Abdul Gafur Iis Nurhasanah Iis Nurhasanah Irman, Iriani Isumarni, Isumarni Jamaluddin Ahmad Jumiati Jumiati Khalik, Suhartini Khoiri, Rahma Kurniawaty Lia Handayani Lia Handayani Lia Handayani Linda Suyati Luqman Buchori M. S.H. Yoga S. Majid, Abdul Majid Zainuddin Mega Bara Cahyantari Muh. Rohady Ramadhan Muhammad Rusdi Muslim, Agus Mustanir, Ahmad Nabila Amalia Izaaz Aanisa Narita Rizki Nayla Zahra Kamalia Nonci, Nurjannah Noor Afifah Nur Hidayati Nurhayati Nurhayati Nurhayati Nurhayati Nurjannah Nonci Nurlaelah Nurlaelah, Nurlaelah Nurul Latifah Nurwidah, Andi Pandji Triadiyaksa Pardoyo Pardoyo Pardoyo Pardoyo Popi Hadi Wisnu Wardhani Prasetya, Eko Fery Prisca Putri Elesta Pungki Hanipa R Kasau, Nurzin Rahayu, R.A. Yunita Suci Rahayu, Yunita Suci Rahmatul Fazira Rahmawati Rahmawati Rasman Ratna Balgis Redi Joko Prasetyo Richard Leonardo Sianturi Rissa Kharismawati Rizka Andianingrum Roni Adi Wijaya Samratusabri Subehan Siringoringo, Eliezer Patardo Siti Fatimah Siti Nurhayati Siti Susanti, Siti Slamet Priyono Tamrin, Muh Taslimah Taslimah Teguh Iman Prastyo Titik Lestariningsih Titik Lestariningsih Tri Windarti Tri Windarti Triadiyaksa, Pandji Trie Nanda Mulyana Trisnasari, Damayanti Ulya Hanifah Henrika Putri Vega Norma Rafika Putri Wijayanti, Septi Yeni Aprilia Yusrianti Yusrianti, Yusrianti Zainuddin, Abdul Majid