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All Journal METANA JDM (Jurnal Dinamika Manajemen) Prosiding Seminar Nasional Teknoka DHARMA EKONOMI Jurnal Pengelolaan Laboratorium Pendidikan Metalurgi Jurnal Ilmu Manajemen dan Akuntansi Terapan Prima Ekonomika : Jurnal Ekonomi dan Bisnis Jurnal TIKOMSIN (Teknologi Informasi dan Komunikasi Sinar Nusantara) Journal of Practical Computer Science (JPCS) Makara Journal of Technology Prosiding Seminar Nasional Teknik Sipil UMS Metalurgi Jurnal Pengabdian Masyarakat Ilmu Komputer
Sri Harjanto
Departemen Metalurgi dan Material, Fakultas Teknik, Universitas Indonesia, Depok 16424, Indonesia
Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Education Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Social Sciences

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Mechanical Alloying-assisted Coating of Fe–Al Powders on Steel Substrate Noviyanto, Alfian; Harjanto, Sri; Widayatno, Wahyu Bambang; Wismogroho, Agus Sukarto; Amal, Muhamad Ikhlasul; Rochman, Nurul Taufiqu
Makara Journal of Technology Vol. 24, No. 3
Publisher : UI Scholars Hub

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Abstract

The coating layer of Fe–Al powders on the steel substrate was prepared by mechanical alloying at room temperature. Fe, Al, and the steel substrates were milled with high-energy ball milling for 32 h with a ball-to-powder ratio of 8 in an argon atmosphere to prevent oxidation during milling. Although mechanical alloying was performed for 32 h, no new phases were observed after mechanical alloying, as analyzed by X-ray diffraction. However, the crystallite size of the milled powders for 32 h decreased by factor two compared with the initial powders. Scanning electron micrographs showed that the coating layers formed >8 h after mechanical alloying. The intermetallic Fe3Al formed after the substrate was annealed at 500 ℃.
PENERAPAPAN METODE K-MEANS CLUSTERING DALAM PENGELOLAAN KESEJAHTERAAN SOSIAL DI DESA PENTUR Hakim, Rifaldi Ali; Harjanto, Sri; Wibowo, Ari
Jurnal Teknologi Informasi dan Komunikasi (TIKomSiN) Vol 12, No 1 (2024): Jurnal TIKomSiN Vol 12, No. 1 April 2024
Publisher : STMIK Sinar Nusantara

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30646/tikomsin.v12i1.820

Abstract

Managing aid to improve social welfare in the Pentur village environment is carried out conventionally and requires special attention so that it is not misdirected. Community welfare can be seen from several aspects, namely sufficient income, adequate education and health. The application of the k-means clustering method in managing social welfare in Pentur village will facilitate the performance of the village government in improving the social welfare of its citizens. The clustering process, with the calculations used are variables based on family dependents, monthly income of the head of the family and property ownership. K-Means clustering is a method that divides data into groups that have objects with the same characteristics. The results of applying k-means clustering for the Social Welfare cluster are divided into 3 parts, namely cluster 1 or low gets a result of 11, cluster 2 or medium gets a result of 11, and cluster 3 or high gets a result of 3. The results of the validity test are carried out using calculations silhouette coefficient and produces a global s(i) value of 0.360222796 and can be said to be good because there are no numbers that show < 0 or no over lapping occurs so it can be said that the data that has been processed has good quality.
The Effect of pH and Sodium Silicate Dosage on the Separation of Magnesium and Lithium from Artificial Brine Water Using Chemical Precipitation Techniques Lalasari, Latifa Hanum; Sulistiyono, Eko; Harjanto, Sri; Irawan, Januar; Firdiyono, Florentinus; Arini, Tri; Andriyah, Lia; Suharyanto, Ariyo; Natasha, Nadia Chrisayu; Yunita, Fariza Eka
Metalurgi Vol 38, No 3 (2023): Metalurgi Vol. 38 No. 3 2023
Publisher : National Research and Innovation Agency (BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/metalurgi.2023.728

Abstract

This study aims to report the findings of an investigation into the separation of lithium and magnesium ions in the artificial brine water. The artificial brine water contains concentrations of magnesium, calcium, and lithium cations that closely resemble the concentrations seen in natural brine water sourced from Gunung Panjang using magnesium chloride, calcium chloride, and lithium chloride p.a. The objective of this experiment was to investigate the impact of pH and the addition of sodium silicate on the separation of magnesium and calcium ions from lithium ions in artificial brine water. The best outcomes were achieved when the pH of the brine water was set at 10, and sodium silicate was added in a stoichiometric ratio of 219%. These parameters led to a lithium content of 90.06%, magnesium removal of  70.32%, and a Mg/Li ratio of 6.29, indicating a substantial presence of magnesium ions precipitated as solids with pyroxene (MgSiO3) phase. This research also succeeded in increasing the lithium content by 94.28% and reducing the Mg/Li ratio to 4.96 after the precipitated solids were subjected to a water-leaching process.
PENGEMBANGAN MEDIA PEMBELAJARAN INTERAKTIF MATA PELAJARAN MATEMATIKA Waskitho, Anggit Widhi; Siswanti, Sri; Raharja, Bayu Dwi; Teguh Susyanto; Irawati, Tri; Wijayanto, Hendro; Vulandari, Retno Tri; Harjanto, Sri
Jurnal Pengabdian Masyarakat Ilmu Komputer Vol. 1 No. 2 (2024): Mei
Publisher : Yayasan Nuraini Ibrahim Mandiri

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59407/jpmik.v1i2.788

Abstract

Media pembelajaran interaktif mata pelajaran Matematika dengan menggunakan Adobe Flash CS 6 ini berisi materi tentang bangun-bangun yang termasuk dalam kesebangunan dan kongruen. Tujuan pengabdian masyarakat ini adalah menciptakan sebuah aplikasi media pembelajaran interaktif mata pelajaran Matematika materi kesebangunan dan kongruen dengan menggunakan Adobe Flash CS6 di SMP Negeri 24 Surakarta. Materi kesebangunan dan kongruen merupakan materi pelajaran yang membutuhkan banyak contoh dan pratikum dalam proses belajar, jika hanya menggunakan buku yang bersifat monoton, membuat siswa sulit untuk membayangkan apa yang dimaksud soal dan latihan. Hasil berupa aplikasi media pembelajaran interaktif mata pelajaran Matematika materi kesebangunan dan kongruen dengan menggunakan Adobe Flash CS6 yang disertai dengan latihan soal yang dapat digunakan sebagai alat bantu pengajar dalam pembelajaran ataupun digunakan secara mandiri oleh pengguna.
ANALISIS KESADARAN WAJIB PAJAK DALAM MEMEDIASI PENGARUH PENGETAHUAN PAJAK, KUALITAS PELAYANAN DAN PEMERIKSAAN PAJAK TERHADAP KEPATUHAN WAJIB PAJAK HOTEL, RESTORAN DAN HIBURAN: STUDI KASUS DIKABUPATEN JEPARA Salim, Noor; Sulistiyo, Heru; Harjanto, Sri
PRIMA EKONOMIKA Vol. 9 No. 1 (2018): Prima Ekonomika
Publisher : STIE "YKP" YOGYAKARTA

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Abstract

Penelitian ini mengenai kepatuhan wajib pajak hotel, restoran dan hiburan diKabupaten Jepara. Tujuannya adalah menganalisis kesadaran wajib pajak dalammemediasi pengaruh pengetahuan pajak, kualitas pelayanan dan pemeriksaan pajakterhadap kepatuhan wajib pajakSample terpilih melalui purposive samplingsebanyak 91 responden meliputi 46 hotel, 34 restoran dan 11 hiburan di KabupatenJepara. Data diperoleh dengan membagikan kuesioner. Kuesioner yang kembalisebanyan 87 kuesioner. Analisis data menggunakan regresi linier berganda denganmenggunakan Progarm SEM-PLS 4.0.Hasil menunjukkan bahwa pengetahuan pajak, kualitas pelayanan, danpemeriksaan pajak berpengaruh positif signifikan terhadap kesadaran wajib pajak.Kesadaran wajib pajak berpengaruh positif signifikan terhadap kepatuhan wajibpajak. Kesadaran wajib pajak memediasi hubungan pengaruh pengetahuan pajak,kualitas pelayanan, dan pemeriksaan pajak terhadap kepatuahan wajib pajak pengujian normalitas, penyimpangan asumsi klasik, uji fit data dan pengujianhipotesis serta koefisien determinasi
Human Development Index Classification in Central Java Using the K-Nearest Neighbors Method for Data-Driven Policy Making Vulandari, Retno Tri; Harjanto, Sri
Journal of Practical Computer Science Vol. 5 No. 2 (2025): November 2025
Publisher : DPPM Universitas Pelita Bangsa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37366/jpcs.v5i2.5996

Abstract

Human development in Central Java continues to show positive progress, as reflected in the consistent increase of the Human Development Index (HDI) across the province. The HDI serves as a key indicator for assessing the success of initiatives aimed at improving the overall quality of life. It measures how well residents are able to access the benefits of development, including long and healthy lives, education, knowledge, and a decent standard of living. The HDI is influenced by four primary components: life expectancy, expected years of schooling, mean years of schooling, and per capita expenditure. Currently, the Central Bureau of Statistics determines HDI values for each regency and city in Central Java using a specific calculation formula. In this study, we aim to classify these regions into three categories based on their HDI levels: very high, high, and moderate estimate areas. To perform this classification, we applied the K-Nearest Neighbors (KNN) algorithm—an effective, non-parametric method that classifies data points based on the majority class among their nearest neighbors in the feature space. KNN is well-suited for classification tasks involving complex, real-world data, offering both accuracy and interpretability. The classification of the 2024 HDI data using KNN resulted in three distinct groups: Cluster 1 (moderate estimate) includes 18 regions: Cilacap, Banyumas, Purbalingga, Banjarnegara, Kebumen, Wonosobo, Magelang, Wonogiri, Grobogan, Blora, Rembang, Temanggung, Kendal, Batang, Pekalongan, Pemalang, Tegal, and Brebes. Cluster 2 (high estimate) consists of 13 regions: Purworejo, Boyolali, Klaten, Sukoharjo, Karanganyar, Sragen, Pati, Kudus, Jepara, Demak, Semarang Regency, Kota Pekalongan, and Kota Tegal. Cluster 3 (very high estimate) comprises 4 urban areas: Kota Magelang, Kota Surakarta, Kota Salatiga, and Kota Semarang. This classification provides valuable insights into regional development disparities and can support evidence-based planning and policy-making.
ANALISA PENGARUH STRUKTUR ASET DAN NON PERFORMING FINANCING TERHADAP TINGKAT PROFITABILITAS DENGAN STRUKTUR PEMBIAYAAN SEBAGAI VARIABEL INTERVENING: STUDI EMPIRIS PADA KOPERASI SIMPAN PINJAM PEMBIAYAAN SYARIAH DI KABUPATEN JEPARA Muslimin, Muslimin; Winarti HS, Endah; Harjanto, Sri
Jurnal Ilmu Manajemen dan Akuntansi Terapan (JIMAT) Vol. 9 No. 2 (2018): Jurnal Ilmu Manajemen dan Akuntansi Terapan (JIMAT)
Publisher : Sekolah Tinggi Ilmu Ekonomi Totalwin

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1660.86 KB) | DOI: 10.36694/jimat.v9i2.168

Abstract

Savings and Loans Cooperatives Syari'ah Financing in Jepara Regency is a cooperative that must be able to stand alone in carrying out its business activities to earn profits. This research is about level of profitability in syari'ah financing savings and loan cooperative in the Cooperative Office, Small and Medium Enterprises, Labor and Transmigration in Jepara Regency. The aim is to analyze effect of asset structure and Non Performing Financing (NPF) on level of profitability with financing structure as an intervening variable. The sample was selected through 34 purposive sampling cooperatives. Data was obtained by analyzing financial statements of the annual member meetings of each cooperative that reported reports in the Cooperative Office, Small and Medium Enterprises, Labor, and Transmigration in Jepara District from 2013 to 2017. Analysis of data using multiple linear regression using SEM-PLS 4.0 program. The results show that asset structure has a significant negative effect on financing structure. NPF has a significant negative effect on financing structure. The asset structure does not effect profitability. NPF has a significant negative effect on profitability. Financing Structure has a significant positive effect on profitability. Financing to Deposit Ratio mediates effect of asset structure on profitability. The Financing Structure mediates effect of NPF on profitability.
Kajian Lalu Lintas pada Rencana Pembangunan Fly Over HOS Cokroaminoto Kabupaten Sragen Harjanto, Sri; Hidayati, Nurul; Harnaeni, Senja Rum
Prosiding Seminar Nasional Teknik Sipil UMS 2022: Prosiding Seminar Nasional Teknik Sipil UMS
Publisher : Universitas Muhammadiyah Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (398.723 KB)

Abstract

Kabupaten Sragen mempunyai simpul-simpul transportasi jalan strategis yang menghubungkan kabupaten di Provinsi Jawa Tengah dengan Provinsi Jawa Timur, letaknya di perbatasan kedua propinsi tersebut. Salah satu ruas jalan utama di Kabupaten Sragen yang sering macet adalah Jalan HOS Cokroaminoto, Oleh karena itu Pemerintah Kabupaten Sragen berencana membangun fly over yang melintas di atas persimpangan tersebut. Meskipun demikian, fly over ini juga dapat memberikan dampak negatif antara lain kerusakan lingkungan, debu, berubahnya budaya gotong royong, mengurangi interaksi dan kegiatan sosial yang biasa dilakukan sebelum adanya fly over, sehingga perlu kajian yang lebih mendalam terkait karakteristik lalu lintas jaringan jalan saat ini, kinerja jaringan jalan tersebut saat ini dan kondisi jaringan jalan di atas jika di lokasi tersebut dibangun fly over, serta kondisi 5 tahun yang akan datang. Manfaat yang diharapkan dari penelitian ini antara lain, memberikan tambahan wacana dan referensi dalam mengatasi kemacetan lalu lintas dengan pembangunan fly over dan sebagai bahan acuan Pemerintah Kabupaten Sragen dalam membuat kebijakan dan peraturan daerah terkait pembangunan infrastruktur jalan. Jaringan jalan yang ditinjau adalah Jalan HOS Cokroaminoto, Jalan Sultan Agung, Jalan Diponegoro, Jalan Asem dan Jalan Tentara Pelajar, Karakteristik lalu lintas yang ditinjau adalah volume lalu lintas dan kecepatan arus, parameter kinerja jaringan yang ditinjau berupa kapasitas jalan, derajat kejenuhan dan LOS jalan. Fly over diasumsikan terbangun dalam rentang waktu 5 tahun yang akan datang. Jenis penelitian menggunakan metode deskriptif dan kuantitatif karena peneltian ini bersifat factual berdasarkan data yang ada untuk memecahkan masalah yang terjadi pada ruas jalan Hos Cokroaminoto. Data primer didapat dari dari pengamatan langsung di lapangan selama 2 hari ( Senin dan Sabtu). Tipe jalan yang diteliti adalah jalan perkotaan dengan dua lajur – dua arah (2/2 UD). Metode analisis menggunakan MKJI 1997. Hasil analisa kinerja ruas jalan Hos Cokroaminoto didapatkan nilai derajat kejenuhan (DS) kondisi eksisting sebesar 0,61 total dua arah. Untuk kinerja ruas jalan Hos Cokroaminoto pada 5 tahun mendatang sesuai dengan standart MKJI 1997 didadaptkan nilai derajat kejenuhan (DS) pada kondisi ruas jalan eksisting meningkat menjadi 0,78 hasil tersebut menunjukan nilai derajat kejenuhan (DS) telah melebihi ketetapan yang tertulis dalam MKJI 1997. Sesuai hasil analisa 5 tahun mendatang bahwa di ruas jalan Hos Cokroaminoto memang diperlukan pembangunan fly over sebagai salah satu cara untuk mengatasi permaslahan kemacetan jalan tersebut.
Self-Healing Behavior of Hydrothermally Engineered HAp/PAA Coatings on Magnesium Alloy WE43 Erryani, Aprilia; Rokhmanto, Fendy; Setyawan, Albertus Deny Heri; Thaha, Yudi Nugraha; Zakiyuddin, Ahmad; Kartika, Ika; Harjanto, Sri
Metalurgi Vol 39, No 3 (2024): Metalurgi Vol. 39 No. 3 2024
Publisher : National Research and Innovation Agency (BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/metalurgi.2024.780

Abstract

This work examines the self-healing properties and corrosion prevention mechanisms of hydrothermally synthesized HAp/PAA (hydroxyapatite/polyacrylic acid) composite coatings on magnesium alloy WE43. The coatings were produced with different PAA concentrations (0.15, 0.3, and 0.5 wt.%) by a hydrothermal method at 140 °C for 3 hours. The composite layers were analyzed using FTIR (fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and EIS (electrochemical impedance spectroscopy) to assess their structural and electrochemical properties, as well as their self-healing capabilities via a scratch–immersion test in Hank’s solution at 37 °C for 48 hours. FTIR analysis confirmed the simultaneous presence of HAp and PAA phases without any chemical reaction, indicating physical contact through hydrogen bonding. The elevation of PAA concentration markedly affected coating morphology, resulting in denser and more uniform structures characterized by spherical HAp crystals at 0.5 wt.% PAA. SEM analysis following scratching and immersion demonstrated that the 0.5 wt.% PAA coating successfully preserved surface integrity and displayed partial restoration of the injured region via the reprecipitation of Ca–P compounds. The EIS findings indicated that the 0.5 wt.% PAA coating maintained the maximum impedance modulus (>10⁴ Ω·cm²) and a steady phase angle after 48 hours of immersion, therefore affirming its exceptional corrosion resistance and self-healing properties. The results demonstrate that an ideal PAA content fosters a dense, ion-responsive hybrid layer that effectively reinstates barrier characteristics following mechanical impairment. The hydrothermally produced 0.5 wt.% HAp/PAA coating offers an efficient self-healing and corrosion-resistant surface for WE43 magnesium alloy, indicating significant potential for use in next-generation biodegradable implant systems.
Corrosion Behavior of Equiatomic Bio-High Entropy Alloys CoCrMoMnNb Fabricated in Multiple Remelting Processes Rokhmanto, Fendy; Erryani, Aprilia; Setyawan, Albertus Deny Heri; Thaha, Yudi Nugraha; Zakiyuddin, Ahmad; Kartika, Ika; Harjanto, Sri
Metalurgi Vol 39, No 3 (2024): Metalurgi Vol. 39 No. 3 2024
Publisher : National Research and Innovation Agency (BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/metalurgi.2024.782

Abstract

High-entropy alloys are described as equiatomic alloys of more than five elements or materials with five or more element constituents with a high mixing entropy (ΔSmix ≥ 1.5R), where the composition of the element is 5–35%, respectively. One application of HEA (high entropy alloys) materials is in the orthopedic field, where they are developed as biomaterials. Behavior, the correlation between the elemental distribution, and the microstructure of the material were investigated during multiple remelting processes known as Bio-HEAs. The development of Bio-HEAs is exciting in terms of design material, fabrication, and their properties. In this paper, the corrosion behavior and the correlation of the elemental distribution and the microstructure of the material were investigated during the multiple remelting process. The equiatomic CoCrMoMnNb was prepared in vacuum arc melting under an argon atmosphere and melted in a water-cooled copper mold. The total amount of ingot was approximately 25 grams, then flipped and remelted several times, 4, 8, and 12 cycles. The final composition of the alloys was confirmed by EDX (energy dispersive x-ray spectroscopy). The microstructure was investigated with an optical microscope and the SEM (scanning electron microscope). The corrosion parameter occurred in Hank’s solution at 37°C, at a scan rate of 1 mV/s. The CCM-MnNb fabricated with 8 cycles of the remelting process exhibits the lowest corrosion rate (0.0038 mmpy) and donor densities (2.67 × 10¹⁹ cm⁻³), while the charge transfer resistance number is the highest (18250.94 Ω cm⁻²). The outstanding corrosion resistance of the alloys is induced by the presence of the finer dendrites and the chromium oxide (Cr₂O₃) protective layer on the alloy's surface.
Co-Authors Abidin, Faizinal Agus Sukarto Wismogroho, Agus Sukarto Ahmad Zakiyuddin Akhmad Herman Yuwono Alfian Noviyanto Amal, Muhamad Ikhlasul Andriyah, Lia Andriyah, Lia Arbi Dimyati Ari Wibowo Bambang Suharno Bustanul Arifin Duroriyatul Aulya, Duroriyatul Eko Sulistiyono, Eko Eny Kusrini Erryani, Aprilia Firdiyono, Firdiyono Florentinus Firdiyono Hakim, Rifaldi Ali Hanny Hafiar Heru Sulistiyo, Heru Ika Kartika Irawan, Januar Kawigraha, Aji Lalasari, Latifa Hanum Lalasari, Latifa Hanum Marzuki Silalahi Muslimin Muslimin N, Elfi Natasha, Nadia Chrisayu Nofrijon Sofyan, Nofrijon Noor Salim Nurhayati, Neni Octapiani Nurul Hidayati Nurul Taufiqu Rochman P, Nur Vita Pudji Untoro Raharja, Bayu Dwi Raharjo Raharjo Raharjo, R Retno Tri Vulandari Rokhmanto, Fendy Senja Rum Harnaeni Setyawan, Albertus Deny Heri Sri Siswanti Suharyanto, Ariyo Sulistiyowati, Arini Sutono -, Sutono Teguh Susyanto Thaha, Yudi Nugraha Tri Arini, Tri Tri Irawati, Tri Wahyu Bambang Widayatno, Wahyu Bambang Waskitho, Anggit Widhi Wijayanto, Hendro Winarti HS, Endah Yunita, Fariza Eka