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All Journal Jurnal Sosio Ekonomika Bisnis Microbiology Indonesia Seminar Nasional Teknik Kimia Kejuangan Jurnal Zeolit Indonesia Jurnal RESTI (Rekayasa Sistem dan Teknologi Informasi) Neo Teknika: Jurnal Ilmiah Teknologi Journal of Data Science and Its Applications Jurnal SUBLIMAPSI CENDEKIA: Jurnal Ilmiah Pendidikan Jurnal Psikologi Terapan (JPT) Aceh International Journal of Science and Technology Jurnal Kendali Akuntansi Metalurgi

Widi Astuti

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Author-ID : 415342

Religion Agriculture, Biological Sciences & Forestry Arts Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Earth & Planetary Sciences Economics, Econometrics & Finance Education Electrical & Electronics Engineering Engineering Environmental Science Health Professions Immunology & microbiology Industrial & Manufacturing Engineering Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Mathematics Medicine & Pharmacology Nursing Public Health Social Sciences Other

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ANALISIS KINERJA KEUANGAN PADA PERUSAHAAN PDAM Widi Astuti; Eko Wahyuni
Jurnal Kendali Akuntansi Vol. 1 No. 1 (2023): Januari : Jurnal Kendali Akuntansi
Publisher : Universitas Katolik Widya Karya Malang

Pemerintah memperbaiki kondisi hidup masyarakat baik dari bidang sosial, ekonomi, maupun pelayanan dengan taraf peningkatan hidup melalui pembangunan nasional. Kebijakan pemerintah dalam pembangunan nasional yang telah terprogram diantaranya peningkatan sarana air bersih, menyediakan air bersih bersih dan terjamin secara merata kepada semua lapisan masyarakat. Pemerintah mendirikan Perusahaan Air Minum melalui Undang-Undang No. 5 tahun 1962 tanggal 14 Pebruari 1962 tentang Perusahaan Daerah, merupakan badan usaha yang harus menjalankan dua fungsi sekaligus, yaitu sebagai social oriented dan profit oriented. PDAM harus menjalankan kegiatan perusahaan dengan baik terutama peningkatan kinerja perusahaan. Sony Yuwono (2003:23) penilaian kinerja merupakan tindakan yang dilakukan dari berbagai aktifitas dalam rantai nilai yang ada dalam perusahaan

KARAKTERISTIK STRUKTUR MIKRO DAN SIFAT MEKANIK BESI TUANG PUTIH PADUAN KROM TINGGI HASIL THERMAL HARDENING UNTUK APLIKASI GRINDING BALL[Microstructure Characteristic and Mechanical Properties of Thermal Hardened of High Chromium White Cast Iron for Grinding Ball Application] Achmad Sofi; Widi Astuti; Fajar Nurjaman
Metalurgi Vol 28, No 3 (2013): Metalurgi Vol.28 No.3 Desember 2013
Publisher : National Research and Innovation Agency (BRIN)

Pembuatan Refraktori Dari Refraktori Bekas Pakai Kiln Dan Flyash Batubara Dengan Variasi Tekanan Greenbody [Recycling of Used Refractory of Kiln and Coal Fly Ash by Various of Greenbody Presure] Ayu Septriana; Azhar Azhar; Widi Astuti
Metalurgi Vol 32, No 3 (2017): Metalurgi Vol. 32 No. 3 Desember 2017
Publisher : National Research and Innovation Agency (BRIN)

Refractory is one type of ceramic material which is thermostable (high temperature resistant) and has the ability to maintain a good physical and chemical condition at high temperature. Manufacture of refractory in this study using used kiln refractory from cement industry and 15% coal fly ash as additional. This research analyzed the effect of green body pressure produced by physical properties of refractory which made from mixture of used refractory and coal fly ash. Used refractory crushed into large aggregate size -40 +80 mesh and small aggregate size -80 mesh, while fly ash -100 mesh. Then, the two of material mixed. Raw material pressed by press hydrauliuc, with a cube-shaped mold in 5 x 5 x 5 cm size. The pressure of green body varied in 8, 9, 10, 12, and 13 tons. The product tested by archimedes methode to getting apparent porosity and bulk density, and guarded hot plate methode standard use ASTM (C 177-04) to getting the cold crushing strengh and thermal conductivity. Higher pressure molding green body product was obtained with higher compressive strength and bulk density, with lower value of the apparent thermal conductivity and porosity. The highest value for the compressive strength and bulk density was 4.48 MPa; 1.119 g / cm3; the lowest value of thermal conductivity and apparent porosity is 11.60 W / m.K; 22.034%. Those values obtained from green pressure body 13 tons.AbstrakRefraktori merupakan salah satu jenis bahan keramik yang tahan terhadap panas (temperatur tinggi) dan memiliki kemampuan untuk mempertahankan kondisinya baik secara fisik maupun kimia pada temperatur tinggi tersebut. Pembuatan refraktori pada penelitian ini menggunakan bahan baku refraktori bekas pakai kiln pabrik semen dengan tambahan fly ash batubara. Penelitian ini menganalisis pengaruh tekanan green body dari campuran refraktori bekas pakai dan fly ash batubara yang dihasilkan terhadap sifat fisik refraktori tersebut.Bahan baku refraktori bekas pakai dihaluskan dengan distribusi ukuran agregat besar -40+80 mesh dan ukuran agregat kecil -80 mesh, sedangkan fly ash batubara berukuran -100 mesh. Setelah itu kedua bahan dicampur. Pemadatanbahan baku dilakukan dengan menggunakan alat press hydraulic, dengan cetakan berbentuk kubus dengan ukuran 5x5x5 cm. Dilakukan variasi tekanan campuran green body sebesar 8 ton, 9 ton, 10 ton, 11 ton, 12 ton, dan 13 ton. Pengujian produk dilakukan dengan uji apparent porosity (porositas) dan bulk density (densitas) dengan metode archimedes, cold crushing strenght (kuat tekan), dan uji konduktivitas termal bahan dilakukan dengan metode guarded hot plate menggunakan standar ASTM (C 177-04). Pengaruh tekanan green body dari campuran fly ash batubara dan refraktori bekas pakai kiln terhadap sifat fisik refraktori adalah semakin tinggi tekanan pencetakan green body, maka semakin tinggi nilai kuat tekan dan bulk density nya, sedangkan nilai konduktivitas termal dan apparent porosity akan semakin rendah. Nilai tertinggi untuk kuat tekan dan bulk density adalah 4,48 Mpa; 1,119 gr/cm3; nilai terendah konduktivitas termal dan apparent porosity adalah 11,60 W/m.K; 22,034 %. Nilai-nilai tersebut didapatkan dari tekanan green body 13 ton.

Pengambilan Lantanum dan Nikel dari Katalis Bekas Menggunakan Asam Sitrat: Peninjauan Performa secara Kuantitatif Menggunakan Response Surface Method (Lantanum and Nickel Recovery from Spent Catalyst Using Citric Acid : Quantitative Performance......) Himawan Tri Bayu Murti Petrus; Ardyanto Wijaya; Yusuf Iskandar; Danu Bratakusuma; Hendrik Setiawan; Wiratni Wiratni; Widi Astuti
Metalurgi Vol 33, No 2 (2018): Metalurgi Vol. 33 No. 2 Agustus 2018
Publisher : National Research and Innovation Agency (BRIN)

Heavy metals and Rare earth elements (REEs) are nowadays being used widely in many industries from electronics to petroleum industries as catalysts. However, their disposal caused serious problems to the environment. With the sharp growth in its usage, there is a better way to use and utilize valuable metals from secondary sources such as their disposal rather than using new raw materials. The aim of this work is to study the potential of citric acid as a leaching agent to extract lanthanum and nickel in various acid concentration and leaching temperature. The raw material used in this work is spent catalyst from Pertamina Refinery Unit VI, Balongan, Indonesia. The spent catalyst is decarbonized with a heat treatment at 725°C for 10 minutes before the leaching process. The leaching process used 0.1; 1; and 2 M of citric acid with a varied temperature of 30, 60, and 80°C. The lanthanum recovery was calculated by comparing the mass percentage of lanthanum before leaching process and after leaching process using Energy Dispersive X-Ray Spectroscopy (EDX). The results were analyzed by response surface methodology (RSM) and are proved to be a reliable method to depict and analyze the leaching characteristics. The molarity of the citric acid is the most significant independent variables used in the research for lanthanum recovery response. However, based on the Pareto analysis result there are no significant variables that affect the recovery of nickel. The second order polynomial fitting model is also proved to be compatible with the response of lanthanum recovery but is less compatible with nickel recovery. AbstrakPengambilan logam tanah jarang dan logam berat dari sumber sekunder (katalis bekas, limbah padat industri, dan abu terbang) menjadi alternatif karena pertimbangan lingkungan dan ketersediaan bijih di alam yang semakin sedikit. Pertimbangan tersebut yang mendasari studi tentang pengambilan lantanum dan nikel dari katalis bekas dengan menggunakan asam asetat. Bahan untuk penelitian ini adalah katalis bekas dari Penyulingan Pertamina Unit VI, Balongan. Sebelum pelindian dilakukan, katalis bekas didekarbonasi dengan perlakuan panas pada 725 °C selama 10 menit. Proses pelindian dilakukan dengan memvariasikan suhu dan konsentrasi asam asetat. Hasil eksperimen ditinjau menggunakanRSM (response surface methodology) dan terbukti sebagai metode yang dapat diandalkan untuk menggambarkan dan menganalisis karakter proses pelindian. Molaritas asam merupakan variabel independen yang secara signifikan mempengaruhi respon dalam pengambilan lantanum. Walaupun begitu, berdasarkan hasil analisis Pareto, tidak ada variabel yang secara signifikan mempengaruhi pengambilan nikel. Model fitting polinomial orde dua juga terbukti cocok dengan respon proses pengambilan lantanum daripada nikel. Hasil RSM menunjukkan bahwa kondisi optimum dari ekstraksilantanum dan nikel adalah pada pH 2 dan suhu 45 оC dimana lantanum dapat 100% terambil dan nikel sebanyak 60%.

Influence of indigenous mixotrophic bacteria on pyrite surface chemistry: Implications for bioflotation Edy Sanwani; Nuslia Bayangkara Lamandhi; Halimatul Husni; Siti Khodijah Chaerun; Widi Astuti; Fika Rofiek Mufakhir
Microbiology Indonesia Vol. 14 No. 1 (2020): March 2020
Publisher : Indonesian Society for microbiology

Given the low-cost and eco-friendly method, biotechnology has been widely utilized in industries as an alternative for physical and chemical processes, including in the biomining process (e.g., bioflotation and biobeneficiation). However, the use of biochemical reagent, which is selective for certain minerals, has not been well studied. This research was aimed to investigate the potential use of biosurfactant-producing mixotrophic bacteria as an alternative to chemical reagents during bioflotation and biobeneficiation process. Thirteen bacterial strains were investigated for their ability to produce biosurfactants and their effects on the surface properties of pyrite minerals. Bacteria-pyrite interaction experimental results showed that pyrite surface properties became more hydrophilic in the experimental systems inoculated with bacteria adapted with pyrite for 48 h than that without bacterial adaptation to pyrite, which was evidenced by the decrease in the contact angle of pyrite minerals by up to 50%. This evidence was also confirmed by the highest emulsifying index value (51.6%) attained during the bacteria-pyrite interaction. Hence, these bacteria can potentially be applied to selective flotation as pyrite depressants.

Inventarisasi Pemutakhiran Data Jaringan Perpipaan Berbasis Gis Di Kelurahan Sukasari Dan Kelurahan Babakan Kecamatan Tangerang Kota Tangerang Widi Astuti; Sukaryo Sukaryo; Baswindro Baswindro; January Jefry Prasetya
Neo Teknika Vol 9, No 1 (2023): Jurnal Neoteknika Volume 9 No 1 Juni 2023
Publisher : Universitas Pandanaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37760/neoteknika.v9i1.2053

Limbah yang dihasilkan oleh masyarakat maupun industri semakin meningkat seiring dengan kegiatan yang dilakukan. Sistem penyaluran air limbah dan instalasi pengolahan air limbah domestik di perkotaan sangat dibutuhkan dalam rangka pelayanan sanitasi untuk menjaga kualitas lingkungan dari pencemaran dan kerusakan lingkunga.. Kota Tangerang sudah memiliki sistem Kolam Oksidasi yang terdapat di Perumnas Karawaci I. Sistem ini melayani 7.932 sambungan rumah atau 30.617 jiwa penduduk (1,94% dari jumlah penduduk Kota Tangerang). Tujuan dari penelitian ini adalah untuk mengupdate data penggunaan jaringan perpipaan dan mengupdate peta jaringan air limbah. Data survey didapatkan dengan plotingg Global Positioning System (GPS) dan pengisian kuesioner yang disediakan. GPS. Plotingg GPS di lakukan untuk menentukan lokasi dan merekam jejak (track). Dari hasil tersebut kemudian di lakukan isian pada form kuisioner, dan di input ke dalam lembar kerja (Work Sheet) dengan menggunakan perangkat lunak microsoft excel. Hasil survey dilapangan diperoleh jumlah sambungan rumah yang terpasang berjumlah 2.494 unit dengan asumsi dimana satu sambungan rumah dikalikan 5 jiwa, maka jumlah penduduk berjumlah 12.470 jiwa atau dapat dikatak bahwa Kelurahan Babakan baru terlayani sekitar 15% dan Kelurahan Sukasari 43%. Jumlah panjang jaringan perpipaan yang terhubung ke Kelurahan Babakan dan Kelurahan Sukasari berjumlah 25.220,71 Meter berdasarkan hasil analisa GIS. Kata kunci :air limbah domestik, jamban

Metode Outdoor Study Dalam Pembelajaran Ilmu Pengetahuan Alam (IPA) Terhadap Motivasi Belajar Siswa Kelas IV MIN 2 Pandeglang widi astuti; anggi solihah; agus hidayatullah
CENDEKIA: JURNAL ILMIAH PENDIDIKAN Vol 11 No 2 (2023): CENDEKIA: Jurnal Ilmiah Pendidikan
Publisher : STKIP Paris Barantai

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33659/cip.v11i2.276

Abstract This research is motivated by the low learning motivation of class IV students at MIN 2 Pandeglang in science subjects, due to the lack of interest of students in the environment. The formulation of the problem in this study is how effective the outdoor study method is in motivating learning for class IV students of Pandeglang MIN 2 in science learning. This study aims to determine and analyze the effectiveness of the outdoor study method in motivating learning for fourth grade students at Min 2 Pandeglang. This type of research uses the interview method. The research population was the teachers of class IV MIN 2 Pandeglang. The results of this interview tell us that the outdoor study method has proven effective on the learning motivation of fourth grade students at MIN 2 Pandeglang by obtaining an average daily test score of 65 and obtaining an average PTS score of 80. So it can be concluded that the outdoor study method can increase student learning motivation class IV min 2 Pandeglang. Keywords: outdoor study method, learning motivation

ZnO Production from EAF Solid Waste Using Hydrothermal Methods via Oxalate Precipitation Lukman Nulhakim; Imam Prasetyo; Monna Rozana; Widi Astuti
Aceh International Journal of Science and Technology Vol 12, No 1 (2023): April 2023
Publisher : Graduate Program of Syiah Kuala University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13170/aijst.12.1.29579

Electric Arc Furnace (EAF) waste contains 50-60% Zn. EAF waste synthesis has the potential to produce ZnO, which can be used in a variety of applications. The hydrothermal method is used in the synthesis, with time variations of 3 and 6 hours and temperature variations of 120 °C, 150 °C and 200 °C using precipitating reagents in the form of sodium hydroxide (NaOH) and oxalic acid (C2H2O4). UV-Vis spectrophotometer characterization result shows the absorbance value at 365 nm, which is the absorbance characteristic of ZnO material. The result of increasing the Zn element was revealed by XRF characterization. The XRD characterization revealed zinc oxalate dehydrates. This result depicts the hydrothermal with the oxalic acid solvent used to produce zinc oxalate dehydration at various temperatures and time variations.

Co-Authors Achmad Sofi Adil Jamali Adiwijaya Agus Hidayatullah Agustien Zulaidah Agustin, Niyar Candra Alvianda Ricky Lukman anggi solihah Anief Rufiyanto Aprimal Aprimal Apriyanti, Eny Aprolita Aprolita Ardyanto Wijaya Arsyad Lubis Ayu Septriana Azhar Azhar Baswindro Baswindro Cahya Novita Danu Bratakusuma Dinda Tri Novira Edy Sanwani Eko Wahyuni Fajar Nurjaman Fika Rofiek Mufakhir Ghina Khoerunnisa Halimatul Husni Hendrik Setiawan Himawan Tri Bayu Murti Petrus Ika Amalia Imam Prasetyo January Jefry Prasetya Jondri Kasman Kasman Laksono Trisnantoro Lukman Nulhakim Luluk Siti Zulaechah Monna Rozana Muhammad Amin Mujiono Mujiono Nuslia Bayangkara Lamandhi Rahmia Dewi Rini Julistia Riska Chairunisa Siska Siska SITI KHODIJAH CHAERUN Soehartono Soehartono Stefanus Lian Kristian Sukaryo Sukaryo Wiratni Wiratni Yara Andita Anastasya Yuliyana Yuliana Yustika Kusumawardani Yustika Kusumawardani Yustika Kusumawardani

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