Investigation of the Size Control of Copper Ferrite Nanoparticles on their Electrical Properties in a Ferrofluid System using Oleic Acid Surfactant as an Energy Harvester

This research develops an energy harvesting system based on CuFe2O4 (copper ferrite) ferrofluid with size control using oleic acid as surfactant. The synthesis of copper ferrite nanoparticles as ferrofluid filler was carried out using the sonochemical method with the main iron source material being iron sand from Sine Beach, Tulungagung. Copper ferrite nanoparticles were coated with oleic acid in various volumes to control their size. After being completely coated, the mixture is dispersed in olive oil to become a complete ferrofluid. A series of characterizations was carried out comprehensively to confirm the success of this research, including characterization of structure, morphology, functional groups, and electrical properties. The structure of copper ferrite nanoparticles was identified using an X-ray diffractometry (XRD) instrument. It was discovered that the size of copper ferrite nanoparticles was 9.7 nm, and the structure formed was spinel reverse cubic with the highest peak of the HKL (3 1 1) plane located at an angle of 35.5°. The morphology of copper ferrite nanoparticles was observed via scanning electron microscope (SEM). Based on the results obtained, copper ferrite nanoparticles appear to agglomerate with particle clusters reaching 52 nm and an average particle size distribution of 25.1 nm. Functional group characterization was carried out using Fourier transform infrared (FTIR). The results showed that all precursors in the ferrofluid system had successfully emerged and formed. Analysis of electrical characteristics was carried out through I-V testing, and it was obtained that the CF3 sample with a volume of 3.6 mL of oleic acid had the highest current values of 13.1 μA, however, the three samples showed a good response and were representative for use as an energy harvester, which is promising

INTEGRASI KONSERVASI BANGUNAN CAGAR BUDAYA DAN TEKNOLOGI IMERSIF DALAM DESAIN INTERIOR PAMERAN SENI: STUDI KONSEPTUAL ARTSUBS 2025 DI POS BLOC SURABAYA

Designing interior exhibitions within cultural heritage buildings requires a balanced approach between preserving historical values and creating innovative spatial experiences. This study aims to develop an interior concept for the Artsubs 2025 exhibition at Pos Bloc Surabaya by integrating conservation principles and immersive technology. The method used is design thinking, consisting of six stages: understand, observe, point of view, ideate, prototype, and test, with data collected through field observation, literature review, and interviews. The design results show that a non-destructive conservation approach combined with immersive media—such as interactive projections, augmented reality, and sensory-based installations—can offer a compelling spatial experience without altering the building’s architectural integrity. The main concept, “Tirta Pratala,” represents a thematic narrative through spatial zoning inspired by water and earth elements. This study contributes to the field of conservation-based interior exhibition design, highlighting its relevance to both local cultural context and contemporary technological innovation

Membangun Kesadaran Finansial: Integrasi Literasi Fintech dan Pengendalian Perilaku Konsumtif

Perkembangan teknologi digital telah membawa perubahan signifikan pada masyarakat dalam mengakses dan menggunakan layanan keuangan. Kemudahan bertransaksi serta pengelolaan keuangan dapat dilakukan melalui perangkat digital yaitu financial technology (fintech). Di sisi lain, juga membawa tantangan tersendiri yaitu perilaku konsumtif khususnya kalangan remaja. Kegiatan service learning ini bertujuan untuk meningkatkan literasi keuangan melalui edukasi terkait perilaku konsumtif pada siswa SMA Mawar Sharon. Metode pelaksanaan berupa kegiatan penyuluhan dan diskusi interaktif yang melibatkan siswa secara aktif, dengan materi meliputi pemahaman dasar tentang fintech, jenis-jenis layanan keuangan digital (seperti e-wallet, paylater, dan investasi online), serta strategi dalam mengatur pengeluaran agar tidak terjadi pemborosan. Hasil kegiatan menunjukkan adanya peningkatan pemahaman siswa mengenai pentingnya pengelolaan keuangan pribadi dan potensi risiko dari penggunaan fintech yang tidak bijak. Edukasi ini diharapkan dapat membentuk kesadaran finansial sejak dini pada siswa SMA serta mendorong perilaku yang bijaksana dalam keuangan agar menjadi generasi muda yang cerdas dan berwawasan luas dalam pengambilan keputusan finansial di era digital

Experimental and Confining Pressure Analysis of Steel Clamp Confined Unreinforced Concrete Subjected to Axial Concentric Load

Vertical cracks and spalling of the concrete cover in reinforced concrete structures are examples of failure modes of concrete columns due to repeated earthquake loads. Strengthening methods have been introduced including external jacketing using costly carbon FRP. This study investigated external strengthening of cylindrical concrete using low-cost thin steel confining sheets subjected to concentric axial loads. The experimental works in this study tested the tensile strength of the confining steel elements, the compressive strength of unconfined and confined cylindrical concrete. The composition of the steel confining elements is positioned in such that it could generate an optimal confinement effect and prevent local buckling. This study also developed the formulation of the confining stress and ultimate axial load based on the test results of the current study and past research data. The results showed that the use of steel clamp elements improves the axial strength and axial deformation of cylindrical concrete columns by over 200% without buckling of the clamp elements. The external confinement method can reduce vertical cracks and strain localization that usually occur in conventional cylindrical concrete. The proposed formulation of the confining stress and the ultimate axial load provided accurate results compared to the experimental results

Tenant satisfaction and property reputation of trade centers in Surabaya, Indonesia

Purpose Trade centers are operationally run by a property manager as a delegate of the property owner. The dimensions of service quality (SERVQUAL), which include tangibles, assurance, empathy, reliability and responsiveness, are vital to be implemented as the duties of property managers when providing service to tenants to maintain tenant satisfaction and property reputation. This study aims to understand the effects of the SERVQUAL dimensions, the role of property management and the quality of rental value on tenant satisfaction and property reputation. Design/methodology/approach The sample was gathered using the purposive sampling technique with the criteria of being a tenant and kiosk owner in trade center properties in Surabaya. Data were gathered using questionnaires, from which 100 respondents were acquired. It was then analyzed using the partial least square structural equation model (SEM) in the SmartPLS 3.0 program to test the hypothesis. Findings The results of this study prove that the SERVQUAL dimensions � assurance, empathy and responsiveness � significantly influence tenant satisfaction with the mediating variable of the role of property management. Moreover, the SERVQUAL dimensions � empathy, reliability and responsiveness � significantly influence property reputation with the mediating variable of the role of property management. Practical implications Property managers are expected to proactively map out different service measures related to the dimension of satisfaction by conducting service training programs for their employees. In fact, in the post-pandemic period, property managers require new marketing strategies, such as leaseback, to effectively carry out renovations of the trade center�s public facilities and restructure the tenant mix. Originality/value Trade centers as trading areas experience management limitations because of the prohibition of mass gatherings during the COVID-19 pandemic, resulting in a limited number of onsite trading. Tenants who have entered into a long-term contract experience loss and rely on the aid of property management to survive. The role and quality of service of property management influence tenants� satisfaction post-COVID-19 pandemic

KEKERASAN DALAM ORGANISASI

Kekerasan dalam organisasi adalah masalah yang serius dan seringkali terabaikan, baik dalam konteks dunia kerja maupun di dalam struktur sosial organisasi secara umum. Kekerasan dalam konteks organisasi tidak hanya terbatas pada kekerasan fisik, tetapi juga mencakup kekerasan psikologis, verbal, hingga diskriminasi yang terjadi dalam lingkungan kerja. Meskipun perhatian terhadap masalah ini semakin meningkat, namun banyak organisasi yang masih belum memahami dengan baik dampak yang ditimbulkan oleh kekerasan terhadap kinerja, motivasi, dan kesejahteraan karyawan. Buku ini berusaha untuk memberikan pemahaman yang komprehensif mengenai kekerasan dalam organisasi, mulai dari definisi, penyebab, dampaknya, hingga cara-cara pencegahan dan penanggulangan yang bisa dilakukan oleh manajer dan pemimpin organisasi. Buku ini juga akan mengulas berbagai teori yang menjelaskan fenomena kekerasan dalam organisasi, serta praktik-praktik terbaik yang bisa diterapkan dalam mengelola kekerasan di tempat kerja. Selain itu, buku ini juga menyertakan studi kasus dari berbagai organisasi, baik yang ada di Indonesia maupun di luar negeri, untuk memberikan gambaran nyata tentang bagaimana kekerasan dalam organisasi dapat terjadi dan bagaimana cara menanganinya. Melalui buku ini, diharapkan pembaca dapat lebih memahami dan mengidentifikasi potensi kekerasan dalam lingkungan organisasi, serta menemukan solusi yang tepat untuk menciptakan tempat kerja yang sehat dan produktif

Analysis of Time Delay Factors in Multi Storey Building Construction Projects in Indonesia on Professionalism and Work Ethics (LNCE)

Analysis of Time Delay Factors in Multi Storey Building Construction Projects in Indonesia on Professionalism and Work Ethic

Kontrol Lampu PJU yang Disupplai Solar Cell dengan Ardhuino

Solar cell berfungsi untuk menangkap cahaya matahari yang akan diubah menjadi energi listrik melalui proses photovoltaic. Listrik yang dihasikan oleh solar cell langsung disimpan di dalam baterai. Saat solar cell bekerja (mengecas), tegangan solar cell dinaikkan maka kondisi relay dalam keadaan tertutup dan baterai dalam proses diisi. Jika proses pengisian energi dari solar cell ke baterai sudah penuh maka kondisi relay dalam keadaan terbuka secara otomatis. Sistem charging/discharging dan on / off lampu PJU menggunakan 2 relai yang dikendalikan oleh microcontroller yaitu Arduino Mega yang menerima, mengelola, dan mengirim data dari pembacaan sensor. Hasil dari pembacaan akan ditampilkan pada LCD yang telah terpasang. Pengujian dilakukan dengan melakukan beberapa percobaan yaitu dengan mengambil data pengisian menggunakan solar cell untuk sistem charge/discharge. Secara keseluruhan alat yang dibuat dapat bekerja dan berfungsi sebagaimana yang diharapkan tetapi kekurangan alat ini adalah menggunakan solar cell dimana daya pengisiannya kecil saat musim hujan. Berdasarkan perhitungan analisa kecukupan dibutuhkan minimal panel surya 135 Wp untuk dapat memenuhi kebutuhan energi lampu PJU dan membuat baterai tidak terkuras habis yang dapat merusak komponen batera