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ANALISIS SISTEM TRANSMISI PADA MESIN PEMINTAL BENANG DENGAN KAPASITAS 3 CONS Laksanwati, Ellysa Kusuma; Rofiroh, Rofiroh; Setiawan, Satria Bagus
Motor Bakar : Jurnal Teknik Mesin Vol 8, No 2 (2024): Motor Bakar: Jurnal Teknik Mesin
Publisher : Universitas Muhammadiyah Tangerang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31000/mbjtm.v8i2.5702

Abstract

Peningkatan kapasitas produksi telah menjadi tinjauan yang sangat penting dalam suatu industri. Maka sekarang perlu inovasi suatu konsep untuk mengembangkan dan memajukan industri kecil tersebut supaya hasil produksi gulungan benang semakin meningkat, dengan cara menciptakan suatu mesin penggulung benang yang lebih modern untuk menggantikan mesin penggulung benang yang masih tradisional. Dari sini timbul pemikiran suatu ide yaitu membuat suatu mesin penggulung benang dengan menggunakan tenaga motor listrik karena mesin dapat menggulung benang dengan cepat dan dengan mendapatkan hasil yang lebih baik. Poros motor listrik yang digunakan dikenai momen puntir (torsi) sebesar 0,68 (Nm). beban (W) yang bekerja pada poros motor listrik sebesar 113,66 N. Terdapat ukuran panjang pasak 4,23 (mm) dan 16,30 (mm). Diambil ukuran pasak 16,30 (mm), dengan alasan gaya akibat tekanan bidang lebih besar dibandingkan besarnya gaya yang akan memutuskan pasak. Pulli digerakkan sebesar 800 Rpm. Jenis sabuk disini adalah tipe A dengan ukuran lebar 12,5 mm, tinggi 9 mm dan dengan sudut 2 . Jenis bahan sabuk adalah leather/kulit. Dengan demikian perencanaan sabuk dikatakan aman, karena 7,44    30 . Dari tabel tersebut didapat ukuran 1070,42 mm dengan standar nominal sabuk ukuran 41. Daya yang ditransmisikan oleh sabuk adalah 4078,26 Watt.
Analisis Perbandingan Campuran Aditif Etilen Glikol 30 banding 70 dan 50 banding 50 Pada Cairan Sistem Pendingin Toyota New Rush 1.5 MT Candra, Riki; Rofiroh, Rofiroh
Motor Bakar : Jurnal Teknik Mesin Vol 7, No 2 (2023): Motor Bakar: Jurnal Teknik Mesin
Publisher : Universitas Muhammadiyah Tangerang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31000/mbjtm.v7i2.9905

Abstract

A vehicle engine is a system that works simultaneously, which during operation can cause an increase in temperature due to the operation of an engine. Ethylon glycol is an additive used as a medium in cooling systems. When using coolants, ethylene glycol is often mixed with distilled water to obtain effective heat absorption results in the radiator. With an ethylene glycol composition of 30 to 70, namely a mixture of 30% ethylene glycol and 70% distilled water, and an ethyl glycol composition of 50 to 50, namely a mixture of 50% ethylene glycol and 50% distilled water for radiator use in the 2019 Toyota new Rush 1.5 MT. This test aims to obtain a comparison of the temperature values resulting from heat dissipation in the radiator between the two types of coolant composition. Tests carried out with rotations of 800, 1600, 2400 and 3200 RPM obtained results from using 30/70 colant, namely an average working temperature of 94.3oC and from using 50/50 colant, namely an average working temperature of 92.8oC. The use of LLC 30/70 coolant is 1.72% hotter than SLLC 50/50 coolant..
ANALISIS PENGARUH ARUS LISTRIK DAN PULSE ON-TIME DALAM ELECTRICAL DISCHARGE MACHINING TERHADAP KEKERASAN PERMUKAAN BAJA SKD11 DAN SUJ2 MENGGUNAKAN METODE PERHITUNGAN ANOVA Rofiroh, Rofiroh; Rosyidin, Ali; Iskandar, Ahmad; Mahardika, Marlindo
Motor Bakar : Jurnal Teknik Mesin Vol 8, No 3 (2024): Motor Bakar: Jurnal Teknik Mesin
Publisher : Universitas Muhammadiyah Tangerang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31000/mbjtm.v8i3.12193

Abstract

Electrical Discharge Machining (EDM) adalah metode permesinan non-konvesional yang melibatkan pemanfaatan energi panas yang dihasilkan dari percikan listrik antara elektroda dan benda kerja. Tujuan penelitian ini adalah menganalisis pengaruh perubahan arus listrik dan pulse on-time terhadap kekerasan permukaan Baja SKD11 dan SUJ2 pada proses machining EDM. Dalam penelitian ini lebih difokuskan pada perbandingan dua jenis baja, yaitu Baja SKD11 dan SUJ2. Adapun Baja SKD11 dikenal dengan kekerasan tinggi yang sangat cocok untuk pembuatan cetakan, alat potong presisi dan perkakas industri lainnya, sedangkan Baja SUJ2 ditandai dengan ketahanan aus yang luar biasa untuk pembuatan bantalan serta komponen mesin yang bekerja dalam kondisi gesekan dan beban berat. Proses permesinan menggunakan perubahan parameter arus listrik dengan variasi nilai 4A, 7A dan 10A serta nilai pulse on-time sebesar 10μs, 20μs, 30μs, 40μs, 50μs, 60μs, 70μs, 80μs, 90μs dan 100μs. Pengujian kekerasan dengan Rockwell Hardness Tester di tiga titik berbeda dan menggunakan satuan uji HRB. Nilai kekerasan permukaan Baja SKD11 terkecil terdapat pada arus listrik 4A dengan pulse on-time 10μs yaitu 55,3 HRB dan terbesar pada arus listrik 10A dengan pulse on-time 100μs yaitu 72 HRB. Sedangkan nilai kekerasan permukaan Baja SUJ2 terkecil terdapat pada arus listrik 4A dengan pulse on-time 10μs yaitu 61,66 HRB dan terbesar pada arus listrik 10A dengan pulse on-time 100μs yaitu 80 HRB.
Pemodelan Matematika dan Analisis Kestabilan Model Pada Penyebaran HIV/AIDS Tipe SITA (Susceptible, Infected, Treatment, AIDS) Mahuda, Isnaini; Rofiroh, Rofiroh
JOSTECH Journal of Science and Technology Vol 4, No 1: Maret 2024
Publisher : UIN Imam Bonjol Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15548/jostech.v4i1.8323

Abstract

HIV/AIDS still become a major public health problem that occurs in almost all countries in the world. Until now, no medicine has been found that can treat HIV/AIDS. However, there is therapy or treatment that can be done to slow the spread of the virus, namely antiretroviral (ARV) or called Antiretroviral Therapy (ART). The mathematical modeling carried out in this study uses the SITA type where there are 4 compartments, namely Susceptible (S), Infected (I) Treatment (T), and AIDS (A) in a closed population. The objectives of this research are: 1) to construct a mathematical model for the spread of SITA type HIV/AIDS, 2) determine the equilibrium point and stability of the equilibrium point of the model, 3) determine the basic reproduction number (R_0), and 4) carry out a dynamic simulation of the model. Mathematical modeling of the spread of SITA type HIV/AIDS produces two equilibrium points, namely the disease-free equilibrium point (E_1) and the endemik equilibrium point (E_2). From the results of the analysis, the basic reproduction ratio (R_0) was also obtained by building a matrix called the Next Generation Matrix (NGM). The basic reproduction ratio number (R_0) also determines the existence and stability of the equilibrium point and can control the rate of spread of HIV/AIDS. Based on the simulation results, the parameter value that greatly influences population dynamics is the rate of treatment given to the Infected (I) sub population.
ETNOMATEMATIKA PADA BATIK SIDOMUKTI INDRAMAYU DALAM PEMBUKTIAN PHYTAGORAS Nirmalasari, Dinar; Rofiroh, Rofiroh; Mahuda, Isnaini
Jurnal Lebesgue : Jurnal Ilmiah Pendidikan Matematika, Matematika dan Statistika Vol. 6 No. 1 (2025): Jurnal Lebesgue : Jurnal Ilmiah Pendidikan Matematika, Matematika dan Statistik
Publisher : LPPM Universitas Bina Bangsa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46306/lb.v6i1.804

Abstract

Batik is a combination of art and technology. Batik has various types and motifs that vary depending on the region. In Indramayu itself there are several types of batik, one of which is batik with the Sidomukti motif. Ethnomathematics is a science that studies the relationship between mathematics and culture. Through this knowledge, various mathematical aspects can be studied that can be found in Sidomukti batik motifs. The aim of this research is to find out the Sidomukti batik motif pattern when linked to the Pythagorean theorem and can be used as an example to convey material proving the Pythagorean Theorem in schools. The research used is qualitative descriptive research with the research object being batik cloth with sidomukti motifs. Mathematically, the sidomukti motif can be approximated by flat rectangular and triangular shapes. From the research, the results showed that there is a mathematical aspect, namely the proof of the Pythagorean Theorem in the Indramayu cultural element, namely the sidomukti batik motif.
EFEKTIVITAS E-MODUL AJAR BERBASIS PEMECAHAN MASALAH UNTUK MENINGKATKAN KEMAMPUAN MAHASISWA PADA MATA KULIAH TEORI BILANGAN Rofiroh, Rofiroh; Nirmalasari, Dinar
Cakrawala Pedagogik Vol 9 No 1 (2025): Cakrawala Pedagogik
Publisher : Sekolah Tinggi Keguruan dan Pendidikan Syekh Manshur

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51499/cp.v9i1.730

Abstract

In the era of digitalization, the world of education is innovating in developing learning methods in the classroom. One of the innovations is creating digital-based learning media such as e-teaching modules. It is hoped that this e-module can help and facilitate students in solving problems, especially in number theory courses. The aim of this research is to determine students' abilities in number theory courses. The research used was quantitative research with the research object being 37 first semester students of class E majoring in mathematics education, FKIP, Sultan Ageng Tirtayasa University. The test results using the Wilcoxon non-parametric test obtained Asymp.Sig.0.000<0.05. This means that there is a significant difference between the pre-test before using the problem solving based teaching e-module and the post-test after using the problem solving based teaching e-module.
PERBANDINGAN METODE PROBLEM BASED LEARNING DENGAN METODE KONVENSIONAL TERHADAP KEMAMPUAN PEMECAHAN MASALAH DAN SELF EFFICACY MATEMATIS MAHASISWA PADA MATA KULIAH MATEMATIKA TEKNIK Laksanawati, Ellysa Kusuma; Rofiroh, Rofiroh
Jurnal Pendidikan Matematika (JUPITEK) Vol 3 No 2 (2020): Jurnal Pendidikan Matematika (JUPITEK)
Publisher : Program Studi Pendidikan Matematika FKIP Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/jupitekvol3iss2pp81-87

Abstract

Penelitian ini bertujuan untuk mengetahui pengaruh metode Problem Based Learning (PBL) dan metode konvensional terhadap kemampuan pemecahan masalah dan self efficacy matematis mahasiswa. Jenis penelitian ini pretest-postest control group design dengan kategori quasi eksperiment. Hasil penelitian uji independent sample t-tes menunjukan bahwa metode PBL lebih efektif dari pada metode konvensional dalam perkuliahan matematika teknik. Hasil uji menunjukan bahwa sig (2-tailed) sebesar 0,000 < 0,005. Dengan kata lain, ada perbedaan antara metode PBL dengan konvensional terhadap kemampuan pemecahan masalah mahasiswa. Besar perbedaannya dari kedua kelas dapat dilihat pada hasil mean postes kelas ekperimen 75,23 dan mean postes kelas kontrol 54,32. Artinya, menunjukan bahwa penerapan metode Problem Based Learning berpengaruh terhadap kemampuan pemecahan masalah mahasiswa dibandigkan metode konvensional. Hal ini linier dengan hasil sebaran angket self efficacy mahasiswa yang diterapkan metode Problem Based Leaning perbedaan dari mahasiswa yang menggunakan metode konvensional. Hasil uji menunjukan Based on Mean adalah 0,03>0,05
Implementation of Cluster Analysis on Districts/Cities in Banten Province Based on Factors Causing Stunting in Toddlers Mahuda, Isnaini; Rofiroh, Rofiroh; Fitriani, Meida
Parameter: Jurnal Matematika, Statistika dan Terapannya Vol 4 No 2 (2025): Parameter: Jurnal Matematika, Statistika dan Terapannya
Publisher : Jurusan Matematika FMIPA Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/parameterv4i2pp329-338

Abstract

Indonesia is a country in Southeast Asia that has the fifth highest prevalence of stunting in world and as a country that has a relatively high stunting rate. Banten Province, as one of provinces in Indonesia, is in the bottom five provinces with the worst stunting cases according to results of Indonesian Toddler Nutrition Status Survey (SSGBI) 2021. Many efforts have been made to resolve this stunting problem. The condition of stunting is usually characterized by the toddler's length or height being less than the normal toddlers of the same age. Several factors causing stunting can be identified so that the government can take appropriate steps to reduce stunting rates in Indonesia, especially in Banten province. Banten province consists of several districts/cities which have their own characteristics, so it is necessary to analyze the grouping of factors causing stunting based on districts/cities in Banten province using hierarchy cluster analysis. The cluster analysis method used in this research was Single Linkage method with Euclidian distance. The results of this research showed that two clusters were obtained based on the grouping results, where first cluster had a higher average percentage of babies born alive with Low Birth Weight (LBW) and percentage of average per capita monthly expenditure for food compared to second cluster. In other hand, percentage of households with access to adequate sanitation and drinking water in first cluster had smaller average value than second cluster.
Ethnomathematical Exploration of Two-Dimensional Shapes in Banten Batik Motifs Nirmalasari, Dinar; Rofiroh, Rofiroh
Jurnal Pendidikan Matematika (JUPITEK) Vol 8 No 2 (2025): in Progress
Publisher : Program Studi Pendidikan Matematika FKIP Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/jupitekvol8iss2pp90-105

Abstract

Indonesia is currently implementing an independent curriculum that emphasizes contextual, differentiated, and learner-centered instruction grounded in students’ cultural environments. Integrating local heritage, such as batik, aligns with these principles and allows students to recognize mathematics as part of their everyday experiences rather than a detached school subject. Typical Banten batik, therefore, holds strong potential as a medium for teaching geometry. This study aims to identify and analyze the plane shapes embedded in Banten batik motifs. A descriptive qualitative method with an ethnographic approach was employed. Data were collected through literature review, interviews, and direct observations of Banten batik, and were analyzed using domain and taxonomic techniques to classify and interpret geometric features. The findings show that Banten batik motifs contain plane geometric elements that represent mathematical concepts naturally embedded in local culture, demonstrating clear connections with flat shapes. The study highlights the significant potential of ethnomathematics-based learning, enabling teachers to connect formal mathematics with students’ cultural knowledge, promote meaningful learning, and strengthen students’ cultural identity and pride.
Efektivitas Bahan Ajar Persamaan Differensial Berbasis Problem Based Learning pada Pokok Bahasan Persamaan Diferensial Rofiroh, Rofiroh; Setiani, Yani; Linda
Cakrawala Pedagogik Vol 9 No 3 (2025): Cakrawala Pedagogik
Publisher : Sekolah Tinggi Keguruan dan Pendidikan Syekh Manshur

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51499/cp.v9i3.840

Abstract

This study aims to test the effectiveness of Differential Equations (PD) teaching materials based on Problem Based Learning (PBL). The main component of teaching materials is a medium to bridge the curriculum with students' learning experiences. The current PD lecture conditions are still dominated by 56% of lecture methods. This results in students having difficulty in understanding applicable concepts and mastering mathematical modeling skills. The research method used is quantitative with a quasi-experimental approach tested on 25 third-semester PD course students. The effectiveness of teaching materials was tested using N-gain analysis and Wilcoxon Signed Rank Test. The results of the study showed a significant increase in the average value from the pre-test (17.24) to the post-test (75.36). The average N-gain of 0.81 is categorized as high. The results of the Wilcoxon Test showed an Asymp.Sig (2-tailed) value of 0.00 <0.05. This means that there is a significant difference between the values ??before and after the use of PBL teaching materials. This is evident from the fact that 92% of students agreed that PBL learning materials can improve their thinking skills in solving PD problems.