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"The objective of the present study is to investigate numerically the problem of melting phase change material (PCM) containing paraffin where one of the area interfaces moves with time and wherein the result of the fusion between the coupling in the solid phase conduction and convection in the liquid phase, then processes the effect of integration of the material in the walls of the building in order to increase its thermal inertia to validate the result ,we will study the numerically transient and performance of a fixed bed filled with uniform spheres, randomly arranged and each containing a (PCM). So we use a two-dimensional theoretical model applied in two separate phases; it was used to predict the temperature distribution of the fluid and the fusible material along the bed in the energy storage method."

"stakeholders in Bali have highlighted the need to investigate and better understand road user behavior as a means of reducing the high proportion of crashes in goods and freight distribution sector. This study aimed to analyze the relationship between self-reported driver behaviors and traffic crashes reported by drivers transporting goods and freight in Denpasar, Bali. A driving safety survey was distributed to 350 goods and freight transport drivers to obtaine a range of demographic information, self-reported crash and offence data, along with psychosocial factors data associated with driving safety. Factor analysis identified a four factor solution with distinctions between di?erent driving practices within the sample consisting of aggresive driving behaviors, driving errors, traffic code violations and normlessness. The results of this study demonstrated that normlessness consisting of behaviors such as taking a slight risk when overtaking and ignoring speed limits were the most common form of unsafe behaviors reported by the goods vehicle transport drivers. The study indicated that speeding behaviors influenced more self-reported driving errors, aggresive behaviors and traffic rule violations and traffic crashes. In addition, drink driving was found to be positively related to traffic crashes. The implications of these results are discussed."

"Telah dilakukan pengamatan terhadap perubahan konduktivitas listrik akibat pemanasan pada Polianilin ( PANT ) yang diperoleh dari hasil polimerisasi Anilin dengan doping asam kuat H2SO4. HO, HCIO4 dan inisiator Amonium Peroksidisulfat. Hasil pengamatan menunjukkan bahwa konduktivitas listrik PANT tergantung pada suhu dan lamanya pemanasan. Pada PANT dengan doping H2SO4 konduktivitas mulai turun drastis pada suhu 200 °C dan pada PAM dengan doping HCI konduktivitas listrik mulai turun pada suhu 120 °C. Sedangkan PANT yang diberi doping HCIO4 konduktivitas listriknya cukup stabil sampai suhu 150 °C. Penurunan konduktivitas listrik ini berkaitan dengan semakin meningkatnya fasa amoif pada PANT setelah dipanasakan. Analisis selanjutnya memperlihatkan korelasi yang konsisten antara turunnya konduktivitas listrik dengan meningkatnya fasa amoif dan lepasnya anion pada PAM yang bersangkutan."

"Experimentation on and implementation of phase-change materials for thermal storage is attracting increasing attention by those seeking a potential resolution to energy issues. This study investigates beeswax as a high thermal-capacity phase-change material with the objective of analyzing the thermal properties and behaviors of beeswax/CuO nano-PCM. The study uses differential scanning calorimetry apparatus to measure the melting temperature and thermal capacity of nano-PCMs. The study found nano-PCM melting temperatures of 63.62°C, 63.59°C, 63.66°C, 63.19°C, and 62.45°C at 0.05, 0.1, 0.15, 0.2, and 0.25 wt%, respectively. FTIR testing found no chemical reaction between CuO and beeswax. The existence of CuO nanoparticles enhanced thermal conductivity of beeswax but reduced its heat capacity. However, the change in latent heat caused no significant effects in the performance of beeswax/CuO. Thus, the results showed that heat transfer of composite beeswax/CuO melts faster than base phase-change material"

"This short book provides an update on various methods for incorporating phase changing materials (PCMs) into building structures. It discusses previous research into optimizing the integration of PCMs into surrounding walls (gypsum board and interior plaster products), trombe walls, ceramic floor tiles, concrete elements (walls and pavements), windows, concrete and brick masonry, underfloor heating, ceilings, thermal insulation and furniture an indoor appliances.Based on the phase change state, PCMs fall into three groups: solid–solid PCMs, solid–liquid PCMs and liquid–gas PCMs. Of these the solid–liquid PCMs, which include organic PCMs, inorganic PCMs and eutectics, are suitable for thermal energy storage.The process of selecting an appropriate PCM is extremely complex, but crucial for thermal energy storage. The potential PCM should have a suitable melting temperature, and the desirable heat of fusion and thermal conductivity specified by the practical application. Thus, the methods of measuring the thermal properties of PCMs are key.With suitable PCMs and the correct incorporation method, latent heat thermal energy storage (LHTES) can be economically efficient for heating and cooling buildings. However, several problems need to be tackled before LHTES can reliably and practically be applied."

"Penelitian ini memiliki tujuan untuk menghasilkan Phase Change Material (PCM) organik berbasis natural wax dan aplikasinya pada manajemen termal bangunan. Selain itu untuk mengetahui pengaruh nanopartikel, yaitu grafena dan MAXene dalam komposit PCM yang dihasilkan melalui metode impregnasi basah. Natural wax yang digunakan adalah soy wax, paraffin wax dan palm wax. Nanopartikel grafena dan MAXene (Ti3AlC2) ditambahkan sebesar 0,1 – 1 wt.% ke dalam PCM untuk meningkatkan konduktivitas termal dan stabilitas termal komposit nano-PCM. Uji siklus termal (500 – 5000 siklus) dan aplikasi manajemen termal hanya dilakukan pada PCM soy wax murni yang memiliki performa terbaik berbanding natural wax yang lain. Alat uji siklus termal berbasis termoelektrik, penambahan 4 modul, desain sederhana, sistem kerja otomatis dan simultan juga dirancang untuk meningkatkan efisiensi waktu pengujian. Nano-PCM dikarakterisasi menggunakan Scanning Electron Microscope- Energy Dispersive X – Ray Spectroscopy (SEM-EDS), Differential Scanning Calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR) dan konduktivitas termal. Hasil konduktivitas termal komposit nano-PCM soy wax-grafena dan soy wax-MAXene masing-masing adalah 0,88 W/mK dan 0,85 W/mK pada 1 wt%. Konduktivitas termal pure soy wax (0,18 W/mK) meningkat sebesar 6,01% untuk soy wax+grafena dan 5,71% untuk soy wax+MAXene. Hasil DSC menunjukkan soy wax dengan penambahan masing-masing grafena dan MXene 0,1 wt% memiliki kenaikan titik leleh sebesar 15% dan 16% serta penurunan titik beku sebesar 14% dan 13%. Hasil uji siklus termal menggunakan pure soy wax dengan alat thermal cycle yang didesign menghasilkan 13 siklus dalam waktu sangat efisien hanya 1 jam pengujian dan setelah 5000 siklus mengalami penurunan ΔH sebesar 60%. Uji performa PCM pada prototipe model dinding bangunan ukuran 101 x 50 x 80 cm untuk skala 1:5 mengunakan polywood dilakukan dengan mengenkapsulasi pure soy wax dalam kantong aluminium foil sebesar 250 g dan ketebalan 1 cm dan pengujian dilakukan selama 24 jam. Aplikasi manajemen termal menunjukkan pure soy wax pack menghasilkan penyerapan panas sebesar 10% dari 41oC menjadi 37oC dibandingkan dengan prototipe bangunan tanpa lapisan soy wax pack. Material maju PCM berbasis pure soy wax memiliki potensi sebagai material manajemen termal pada aplikasi bangunan dan mengoptimalkan penggunaan energi untuk sistem pendinginan pada bangunan.

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This study aims to produce an organic Phase Change Material (PCM) based on natural wax and its application to the thermal management of buildings. In addition, graphene and MAXene in PCM composites were produced through the wet impregnation method to determine the effect of nanoparticles. Natural wax used is soy wax, paraffin wax, and palm wax. Graphene and MAXene (Ti3AlC2) nanoparticles were added at 0.1-1 wt.% to the PCM to increase the thermal conductivity and thermal stability of the nano-PCM composite. Thermal cycle tests (500-5000 cycles) and thermal management applications are only carried out on pure PCM soy wax which has the best performance compared to other natural waxes. Thermoelectric-based thermal cycle test equipment, the addition of 4 modules, a simple design, and an automatic and simultaneous working system are also designed to increase the efficiency of testing time. Nano-PCM was characterized using Scanning Electron Microscope- Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Differential Scanning Calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and thermal conductivity. The thermal conductivity of soy wax-graphene and soy wax-MAXene nano-PCM composites were 0.88 W/mK and 0.85 W/mK at 1 wt%, respectively. The thermal conductivity of pure soy wax (0.18 W/mK) increased by 6.01% for soy wax+graphene and 5.71% for soy wax+MAXene. DSC results showed that soy wax with the addition of graphene and MXene 0.1 wt%, respectively, had a melting point increase of 15% and 16% and a freezing point depression of 14% and 13%, respectively. The results of the thermal cycle test using pure soy wax with a thermal cycle tool designed to produce 13 cycles in a very efficient time of only 1 hour of testing and after 5000 cycles the H decreased by 60%. PCM performance test on a prototype building wall model measuring 101 x 50 x 80 cm for a scale of 1:5 using polywood was carried out by encapsulating pure soy wax in an aluminum foil bag of 250 g and a thickness of 1 cm and the test was carried out for 24 hours. Thermal management application shows that pure soy wax pack produces 10% heat absorption from 41oC to 37oC compared to building prototype without soy wax pack coating. Advanced PCM materials based on pure soy wax have potential as thermal management materials in building applications and optimize energy use for cooling systems in buildings."