Mestro: Jurnal Teknik Mesin dan Elektro

Energy Consumption Index, Energy Evaluasi Indeks Konsumsi Energi Listrik Di Rumah Sakit Daerah Umum R.A. Kartini Jepara

Samuel Kurniawan — 2025-12-29

This study aims to evaluate the electrical energy consumption index at the R.A. Kartini Regional General Hospital (RSUD Jepara). Electrical energy efficiency is a crucial aspect in the management of modern health facilities, especially in efforts to reduce operational costs and environmental impacts. Hospitals as facilities that operate 24 hours have high energy consumption, especially for medical equipment, air conditioning systems, and lighting. This study uses a quantitative descriptive analysis method by processing electricity consumption data in 2018 obtained from official hospital documents. The results showed that the total installed power at the R.A. Kartini Regional General Hospital Jepara reached 1,410,005 VA, with the largest distribution of energy use in medical devices (51.5%), air conditioning systems (38.7%), and mechanical equipment (20.7%) The hospital's Energy Consumption Index (IKE) was calculated at 146 kWh/m²/year, which is included in the "fairly efficient" category according to Indonesian national standards (180-280 kWh/m²/year). However, there is still room for increased efficiency, especially in air conditioning and lighting systems. The research findings show that the application of inverter technology in the AC system, replacing conventional lamps with LEDs, and optimizing the use of mechanical equipment can result in energy savings of up to 25-30%. This study recommends the implementation of a comprehensive energy management system, including periodic energy audits, increasing equipment efficiency, and educating staff about energy-saving practices. With these steps, RSUD R.A. Kartini Jepara can achieve the IKE target of 102-110 kWh/m²/year, approaching international best practices. In addition, this study also provides an important contribution to energy conservation efforts in the health sector, especially in supporting national and global policies on energy sustainability.

Solving the First Order 1-D Wave Equation: A Comparative Study of Upwind and Euler BTCS Methods

Awinda Sari Riawan — 2025-12-29

The simulation of wave propagation in one-dimensional media is fundamental in understanding dynamic systems governed by partial differential equations (PDEs). This study presents a comparative numerical analysis of two finite difference methods, First Upwind Differencing (explicit) and Euler Backward Time Centered Space (BTCS, implicit), applied to the first-order 1-D linear wave equation. The equation models the transport of a disturbance in a closed tube using a constant wave speed of 300 m/s. Both methods are implemented in MATLAB, and simulation results are analysed based on stability, accuracy, and computational characteristics. The upwind scheme demonstrates satisfactory performance with moderate accuracy but suffers from numerical dissipation at lower grid resolutions. In contrast, the Euler BTCS method shows robust stability and higher fidelity to the initial condition, even with relatively large time steps. Results confirm that both methods are capable of generating stable solutions; however, the implicit method offers greater reliability for long-term simulations. This study highlights the trade-offs between computational simplicity and numerical robustness in solving hyperbolic PDEs using finite difference schemes.

Analisis Kinerja Beton Agregat Daur Ulang dengan Penambahan Fly Ash pada Iklim Tropis: Studi Kasus di Lombok Timur

Lalu Ibrohim Burhan — 2025-12-29

Abstract

Sustainability issues in the construction sector encourage the use of alternative materials such as fly ash and recycled aggregates to reduce dependence on natural resources and reduce carbon emissions. However, studies on the synergy of the two materials in concrete systems in tropical climate conditions are still minimal, especially in areas such as East Lombok. This study aims to evaluate the effect of variations in fly ash content on the compressive strength of recycled concrete in the context of humid tropical climates. The study employed a laboratory experimental approach with four variations in fly ash content (0%, 10%, 20%, and 30% by weight of cement) and compressive strength testing at 7, 14, and 28 days of age. A total of 60 cylindrical test objects were printed and tested according to SNI standards, then statistically analyzed using one-way ANOVA. This test aims to determine the significance of differences between treatments, which is then complemented by a post hoc test to identify significant groups. The results showed that the addition of fly ash at a 20% level resulted in the most optimal increase in compressive strength, with an increase of approximately 12% compared to the controls. The primary conclusion of this study is that a 20% fly ash composition can significantly enhance the performance of recycled concrete in tropical climatic conditions. This research makes a significant contribution to the development of environmentally friendly concrete standards, informed by local data and insights. It can serve as a reference in the preparation of technical regulations for sustainable development in tropical regions.

Abstrak

Isu keberlanjutan dalam sektor konstruksi mendorong eksplorasi material alternatif yang lebih ramah lingkungan, seperti fly ash dan agregat daur ulang, untuk mengurangi ketergantungan pada sumber daya alam dan emisi karbon. Namun, kajian eksperimental mengenai sinergi kedua material dalam sistem beton di iklim tropis lembap masih sangat terbatas, khususnya di wilayah seperti Lombok Timur. Penelitian ini bertujuan untuk mengevaluasi pengaruh variasi kadar fly ash terhadap kuat tekan beton agregat daur ulang dalam konteks iklim tropis. Studi dilakukan dengan metode eksperimen laboratorium menggunakan empat variasi kadar fly ash (0%, 10%, 20%, dan 30% dari berat semen) serta pengujian kuat tekan pada umur 7, 14, dan 28 hari. Total 60 benda uji silinder diuji berdasarkan standar SNI, dan data dianalisis menggunakan ANOVA satu arah untuk mengetahui signifikansi pengaruh perlakuan. Uji lanjutan Tukey HSD digunakan untuk mengidentifikasi kelompok yang berbeda secara nyata. Hasil menunjukkan bahwa penambahan fly ash sebesar 20% menghasilkan peningkatan kuat tekan paling optimal (±12%) dibandingkan beton kontrol. Temuan ini menunjukkan bahwa kombinasi fly ash dan agregat daur ulang mampu meningkatkan performa beton secara signifikan di bawah kondisi iklim tropis lembap. Penelitian ini memberikan kontribusi penting bagi pengembangan standar teknis beton ramah lingkungan berbasis data lokal, dan dapat dijadikan referensi dalam perumusan kebijakan pembangunan berkelanjutan di wilayah tropis berkembang

Sistem E-Voting Berbasis Contract Menggunakan Jaringan Blockchain Etherum Dengan Sistem Keamanan Akses Data

Zeni Muhamad Noer — 2025-12-29

Teknologi yang semakin berkembang tentu banyak berefek kepada perubahan sistem yang telah ada pada berbagai bidang, salah satunya adalah perubahan sistem voting atau pemungutan suara. Proses dan sistem pemungutan suara di negara demokratis khususnya Indonesia dilakukan dengan cara konvensional yaitu, menggunakan kertas untuk mementukan pilihan sampai perhitungan hasil akhir suara, hal itu tentu menghabiskan biaya yang tidak sedikit serta proses perhitungan yang memakan waktu dalam pelaksanaannya. Selain itu, sistem pemungutan suara lainnya dengan bantuan teknologi komputer juga terdapat masalah terkait keamanan data dari hasil perhitungan. Oleh karena itu, untuk mengatasi permasalahan tersebut dirancanglah sistem e-voting yang memanfaatkan teknologi smart contract (perjanjian digital) dan jaringan blockchain yang dibuat dengan bahasa pemrograman solidity, sehingga tidak bisa diubah alurnya serta data pemungutan suara yang telah dilakukan tidak dapat dirubah, digunakan atau bahkan dihapus.

Kalkulasi Daya PLTS Untuk Sumber Energi IoT di Danau Laguna Ternate

Andi Muhammad Ilyas — 2025-12-29

This study aims to design a solar photovoltaic (PV) power system as an independent energy source for an Internet of Things (IoT) device used to monitor water quality in Laguna Lake, Ternate. The absence of electrical infrastructure at the site necessitates a reliable and efficient off-grid PV system capable of continuous operation. The energy demand was calculated based on the operational characteristics of the IoT device, including a sampling interval of 15 minutes, resulting in 96 data acquisitions per day. The analysis shows that the total daily energy consumption of the device is 6.85 Wh/day. To ensure three days of autonomous operation in the absence of sunlight, the required stored energy increases to 20.55 Wh, equivalent to 2.14 Ah for a 12 V battery system. The theoretical minimum PV capacity needed to meet this demand is 2.03 W; however, such a size is insufficient for real field conditions due to variations in solar irradiance, potential shading, panel degradation, and the need for long-term operational reliability. Therefore, this study recommends using a 100 W solar panel as a more robust and practical configuration. The outcomes of this research provide a technical foundation for implementing renewable-energy-powered IoT monitoring systems in remote locations without permanent electrical access.

Interprestasi dari Model Perancangan Perencanaan Pembakaran Sampah Dalam Penanganan Sampah Mandiri

Bambang Hermani — 2025-12-29

Proposal of a waste incinerator furnace procurement project, namely a tool or machine for incineration of waste with appropriate technology, simple combustion in the design and planning of mechanical engineering in such a way with a certain high temperature so that the combustion residue is very minimal and without smoke, where the technology is still in the corridor under the industrial revolution 2.0 era, the capacity of the waste incinerator furnace is limited to 0.5 cubic of waste sorted with firewood lighter technology, or with many burner heads erected, with modifications to the water spray smoke path it is expected that the combustion process will produce waste combustion residue in the form of sand ash material, fly ash, with the design and planning of the mechanical engineering idea model, fly ash will be accumulated in a thin water spray chamber where the specific gravity of fly ash is heavier and is collected under the chimney by itself being separated into the downward fly ash path and the upward smoke flow path of the smoke funnel upward in such an optional way to filter air pollution in the environment. The idea of appropriate technology needs to be raised and reviewed with a perspective that remains prominent among mechanical engineering students, as it is the embryo of mechanical scientific ideas. However, most people need appropriate knowledge and technology to facilitate handling related to technology that is immediately practical for all levels of society, very affordable, and environmentally friendly. The model of a waste incinerator for domestic-scale waste management, starting from our own environment to generate good ideas about this technology within the principles of supported mechanical engineering design and planning science. The design model of a waste incinerator is widely published and built, even commercially. Our discussion here begins with planning whether the furnace model is supplied or redesigned with further innovation, the active role of the initiator towards policies and strategies according to the preparation of career opportunities for human resources in increasing equitable progress, which is able to address environmental needs.