東南アジアの成長都市における都市気候の将来予測 : 都市ヒートアイランドと地球温暖化

広島大学(Hiroshima University)博士(工学)Doctor of Engineeringdoctora

Configuration of Green Spaces for Urban Heat Island Mitigation and Future Building Energy Conservation in Hanoi Master Plan 2030

The study aims to assess the urban heat island (UHI) effects in the city under the present land use conditions as well as those conditions proposed by the Hanoi Master Plan 2030 through numerical simulation, using Weather Research and Forecasting (WRF). Furthermore, this paper assesses additional land use scenarios with different spatial and green space configurations. The results show that the implementation of the master plan does not significantly affect the peak air temperature in the built-up areas (approximately 1 °C higher at the maximum). However, high temperature areas, with temperature of 40–41 °C, would expand widely over the new built-up areas. On the other hand, the nocturnal air temperature would increase by up to 2–3 °C over the newly expanded built-up areas. The number of hotspots increased further when the strategic green spaces in the master plan were not taken into account. However, the cooling effect of the strategic green spaces did not reach the existing city center sufficiently because the green spaces are located far from the city center. The large and centralized green spaces proposed in the master plan were seen to be insufficient to mitigate UHIs compared to the equally distributed green spaces. Moreover, the greater reduction of hotspot areas by up to 56.5% was seen when the mixed forest is employed as the land cover in the green spaces

Utilization of Fly Ash and Stone Dust to Improve the Compressive Strength of Mortar

The consumption of raw materials in the construction industry is rapidly increasing each year. Therefore, the construction industry has started turning to sustainable alternative materials, especially concrete and mortar. This research aims to assess the effect of fly ash and stone dust (as alternative materials) in mortar mixtures. For this purpose, mortar samples were prepared by substituting 100% fine aggregate (sand) with stone dust. Additionally, the cement replacement ratio with fly ash was set at 25%, 30%, and 35%. To evaluate the effect of water to binder (w/b) ratio, mortar samples were prepared with w/b ratios set at 0.3, 0.35, and 0.4. Furthermore, samples were cured for 7, 28, 42, and 90 days. The mortar samples were made according to SNI 03-6825-2002, with dimensions of 5x5x5 cm. The results show that different w/b and fly ash ratios affect mortar’s compressive strength. Mortar mixtures with a w/b ratio of 0.35 and a 35% replacement ratio of cement with fly ash are suggested as optimal due to their impressive compressive strength outcomes and environmentally friendly composition. Furthermore, it was also observed that 42 days is the most effective curing period for mortar with fly ash and stone dust

Energy Saving Effort for Residential Buildings in the Hot and Humid Climate: A Review on Ventilation Performance Requirements

Abstract Most Southeast Asian countries have been facing a rapid growth of urbanizations. This greatly affects the increasing demands of housings as well as energy consumption in the building sector, particularly due to the space cooling to achieve indoor thermal comfort. On the other hand, the hybrid cooling strategy has shown a promising potential in energy saving through the combination of mechanical and natural ventilation. Nevertheless, such strategy has not been optimally implemented in the current residential buildings. This study carried out a review on energy-saving related standards and guidelines in several Southeast Asian countries, especially on the requirements for ventilation performance. In addition, this study also carried out Computational Fluid Dynamic (CFD) simulation to investigate the ventilation performance of the existing apartment in Indonesia. In general, most of the countries’ existing standards have not properly accommodated the energy-saving potential through natural ventilation. Moreover, the simulation results show that the indoor air speed and air change rate in the existing apartment are still below the required standards, mostly due to a lack of ventilation strategies in the building design: e.g., selection of opening configuration and window type. Hence, in order to optimize the energy-saving effort, the current standards and guidelines should provide sufficient information and requirement related to the ventilation performance.</jats:p

Hubungan Persepsi dengan Sikap Mahasiswa terhadap Vaksinasi Covid-19 (Studi Mahasiswa Fakultas Ushuluddin dan Studi Agama UIN Imam Bonjol Padang)

Mahasiswa memiliki peran penting dalam menyikapi vaksinasi Covid-19. Tujuan dari penelitian adalah untuk mengetahui tingkat persepsi, sikap dan hubungan persepsi dengan sikap mahasiswa terhadap vaksinasi Covid-19. Metode penelitian yang digunakan adalah pendekatan kuantitatif menggunakan analisis korelasi. Populasi penelitian ini sebanyak 1.831 mahasiswa aktif Fakultas Ushuluddin dan Studi Agama. Teknik sampling yang digunakan adalah proportionate stratified random sampling, dengan jumlah sampel sebanyak 328 mahasiswa. Berdasarkan hasil penelitian diketahui bahwa terdapat 54 mahasiswa (16,5%) yang memiliki persepsi negatif, sebanyak 236 mahasiswa (72,0%) memiliki persepsi yang netral dan sebanyak 38 mahasiswa (11,6%) memiliki persepsi positif. Untuk sikap, terdapat 52 mahasiswa (15,9%) memiliki tingkat sikap tidak setuju, sebanyak 246 mahasiswa (75,0%) memiliki sikap yang netral dan sebanyak 30 mahasiswa (9,1%) memiliki sikap setuju. Sedangkan hasil penelitian ini menunjukkan nilai signifikansi 0.000 Ë‚0,05 sehingga disimpulkan terdapat hubungan antara persepsi dan sikap mahasiswa terhadap vaksinasi Covid-19. Hasil uji korelasi sebesar 0,845 menunjukkan terdapat hubungan sangat kuat karena mendekati angka satu (1)Kata kunci: Persepsi, Sikap, Vaksinasi Covid-1

Configuration of Green Spaces for Urban Heat Island Mitigation and Future Building Energy Conservation in Hanoi Master Plan 2030

The study aims to assess the urban heat island (UHI) effects in the city under the present land use conditions as well as those conditions proposed by the Hanoi Master Plan 2030 through numerical simulation, using Weather Research and Forecasting (WRF). Furthermore, this paper assesses additional land use scenarios with different spatial and green space configurations. The results show that the implementation of the master plan does not significantly affect the peak air temperature in the built-up areas (approximately 1 °C higher at the maximum). However, high temperature areas, with temperature of 40–41 °C, would expand widely over the new built-up areas. On the other hand, the nocturnal air temperature would increase by up to 2–3 °C over the newly expanded built-up areas. The number of hotspots increased further when the strategic green spaces in the master plan were not taken into account. However, the cooling effect of the strategic green spaces did not reach the existing city center sufficiently because the green spaces are located far from the city center. The large and centralized green spaces proposed in the master plan were seen to be insufficient to mitigate UHIs compared to the equally distributed green spaces. Moreover, the greater reduction of hotspot areas by up to 56.5% was seen when the mixed forest is employed as the land cover in the green spaces

Impact of Urban Heat Island under the Hanoi Master Plan 2030 on Cooling Loads in Residential Buildings

This study aims to evaluate the influence of urban heat island (UHI) under the Hanoi Master Plan 2030 on the energy consumption for space cooling in residential buildings. The weather conditions under the current and future status (master plan condition) simulated in the previous study (Trihamdani et al., 2014) were used and cooling loads in all the residential buildings in Hanoi over the hottest month were estimated under the simulated current and future conditions by using the building simulation program, TRNSYS (v17). Three most typical housing types in the city were selected for the simulation. The cooling loads of respective housing types were obtained in each of the districts in Hanoi. The results show that the total cooling loads over June 2010 is approximately 683 Terajoule (TJ) under the current status, but it is predicted to increase to 903 TJ under the master plan condition. The increment is largely due to the increase in number of households (203 TJ or 92%), but partially due to the increase in urban temperature, i.e. UHI effect (17 TJ or 8%). The increments in new built-up areas were found to be larger than those in existing built-up areas. The cooling load in apartment is approximately half of that in detached house, which is approximately half of that in row house. Moreover, it was seen that although sensible cooling loads increased with the increase in outdoor temperature, the latent cooling loads decreased due to the decrease in absolute humidity and the increase in air temperature

Development of a wind catcher for high-rise apartments in the hot-humid climate of Indonesia

Abstract This study aims to develop a new device, “cross-wind catcher”, for mid-to-high-rise affordable apartments for improving the ventilation performance in the tropics, where the natural ventilation is considered essential. We conducted a primary simulation study to find optimum wind catchers, followed by a field experiment using a full-scale experimental building to confirm the effects of the proposed device. The results showed that the proposed cross-wind catcher was able to increase the ACH by approximately 1.2 to 1.4 times compared with the control unit.</jats:p