scholarly journals The Thermal Performance of Chinese Vernacular Skywell Dwellings

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Gang Yao ◽  
Dongting Han ◽  
Li Zhang ◽  
Zhongcheng Duan
Keyword(s):  
Computer Simulation ◽  
Thermal Performance ◽  
Environmental Performance ◽  
Evaporative Cooling ◽  
Construction Materials ◽  
Thermal Mass ◽  
Substantial Influence ◽  
Southeastern China ◽  
The Mean ◽  
Floor Material

The aim of this research was to investigate the thermal performance of Chinese vernacular skywell dwellings. This was done by the analysis of on-site measurements of the environmental performance and computer simulation of solar conditions of eight vernacular skywell dwellings in three villages in southeastern China—Xidi, Zhifeng, and Yuyuan. Through the discussion of several heat inputs and outputs, it can be concluded that evaporative cooling had a substantial influence on the temperature in the skywells of dwellings in Xidi and Zhifeng villages. In addition to the buffering of temperature by thermal mass, evaporative cooling was found to further reduce the fluctuation in temperature inside the skywell and is likely to have been the main reason that the mean dry bulb temperatures inside the skywells in these villages were lower than the mean external dry bulb temperatures. Moreover, the construction materials of Chinese vernacular dwellings (skywell wall, floor material, wooden column, and panels) are likely to be hygroscopic.

scholarly journals User Thermal Comfort in Historic Buildings: Evaluation of the Potential of Thermal Mass, Orientation, Evaporative Cooling and Ventilation

2020 ◽  
Vol 12 (22) ◽  
pp. 9672
Author(s):  
Mamdooh Alwetaishi ◽  
Ashraf Balabel ◽  
Ahmed Abdelhafiz ◽  
Usama Issa ◽  
Ibrahim Sharaky ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
High Altitude ◽  
Air Temperature ◽  
Thermal Performance ◽  
Indoor Air ◽  
Computer Modelling ◽  
Evaporative Cooling ◽  
Comfort Level ◽  
Thermal Mass ◽  
The Impact

The study investigated the level of thermal comfort in historical buildings located at a relatively high altitude in the Arabian Desert of Saudi Arabia. The study focused on the impact of the use of thermal mass and orientation on the level of thermal performance at Shubra and Boqri Palaces. Qualitative and quantitative analyses were used in this study, including a questionnaire interview with architecture experts living at the relatively high altitude of Taif city, to obtain data and information from local experts. The computer software TAS EDSL was used along with on-site equipment, such as thermal imaging cameras and data loggers, to observe the physical conditions of the building in terms of its thermal performance. The study revealed that the experts’ age and years of experience were important aspects while collecting data from them during the survey. The use of thermal mass had a slight impact on the indoor air temperature as well as the energy consumption, but it helped in providing thermal comfort. Use of ventilation can improve thermal comfort level. Evaporative cooling technique has a considerable impact on reducing indoor air temperature with 4 °C drop, improving the thermal comfort sensation level. The novelty of this work is that, it links the outcomes of qualitative results of experts with field monitoring as well as computer modelling. This can contribute as method to accurately collect data in similar case studies.

scholarly journals Application of indirect evaporative cooling strategies for a warm-humid climate

2021 ◽  
Vol 2042 (1) ◽  
pp. 012098
Author(s):  
José Roberto García Chávez ◽  
Anaís Carrillo Salas ◽  
Karina A García Pardo
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Maximum Temperature ◽  
Passive Cooling ◽  
Thermal Mass ◽  
Humid Climate ◽  
Cooling Strategies ◽  
The Mean ◽  
Indirect Evaporative Cooling

Abstract Energy consumption in buildings for air conditioning has augmented worldwide by the escalation in global warming. The application of passive cooling is a promising approach to mitigate this situation. The aim of this research was to assess and characterize the performance of indirect evaporative cooling strategies combined with other passive cooling techniques, applied in experimental modules, aimed at providing hygrothermal comfort. Results showed that the investigated strategies presented lower temperatures than the external conditions and the control module. The alternative that combined indirect evaporative cooling with thermal mass, solar protection, and night radiative cooling was the most promising, with a temperature reduction of 4.2 K, relative to the mean exterior temperature, and a decrease of 8.3 K of its maximum temperature relative to the maximum exterior temperature. An additional strategy was implemented in this alternative using a phase change material, that further reduced its temperature by 6.3 K, relative to the mean exterior temperature and a reduction of 11.5 K of its maximum temperature compared to the maximum exterior temperature. It is expected that these findings are applicable in actual buildings in warm-humid regions to reduce energy consumption for air conditioning, whilst improving hygrothermal comfort and health of occupants.

scholarly journals SOD1 Mutation Spectrum and Natural History of ALS Patients in a 15-Year Cohort in Southeastern China

2021 ◽  
Vol 12 ◽  
Author(s):  
Lu-Xi Chen ◽  
Hai-Feng Xu ◽  
Pei-Shan Wang ◽  
Xin-Xia Yang ◽  
Zhi-Ying Wu ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Natural History ◽  
Diagnostic Delay ◽  
Mutation Spectrum ◽  
Survival Duration ◽  
Southeastern China ◽  
History Of ◽  
Male Patients ◽  
The Mean ◽  
Als Patients

Background: Mutations in superoxide dismutase 1 gene (SOD1) are the most frequent high penetrant genetic cause for amyotrophic lateral sclerosis (ALS) in the Chinese population. A detailed natural history of SOD1-mutated ALS patients will provide key information for ongoing genetic clinical trials.Methods: We screened for SOD1 mutations using whole exome sequencing (WES) in Chinese ALS cases from 2017 to 2021. Functional studies were then performed to confirm the pathogenicity of novel variants. In addition, we enrolled previously reported SOD1 mutations in our centers from 2007 to 2017. The SOD1 mutation spectrum, age at onset (AAO), diagnostic delay, and survival duration were analyzed.Results: We found two novel SOD1 variants (p.G17H and p.E134*) that exerted both gain-of-function and loss-of-function effects in vitro. Combined with our previous SOD1-mutated patients, 32 probands with 21 SOD1 mutations were included with the four most frequently occurring mutations of p.V48A, p.H47R, p.C112Y, and p.G148D. SOD1 mutations account for 58.9% of familial ALS (FALS) cases. The mean (SD) AAO was 46 ± 11.4 years with a significant difference between patients carrying mutations in exon 1 [n = 5, 34.6 (12.4) years] and exon 2 [n = 8, 51.4 (8.2) years] (p = 0.038). The mean of the diagnostic delay of FALS patients is significantly earlier than the sporadic ALS (SALS) patients [9.5 (4.8) vs. 20.3 (9.3) years, p = 0.0026]. In addition, male patients survived longer than female patients (40 vs. 16 months, p = 0.05).Conclusion: Our results expanded the spectrum of SOD1 mutations, highlighted the mutation distribution, and summarized the natural history of SOD1-mutated patients in southeastern China. Male patients were found to have better survival, and FALS patients received an earlier diagnosis. Our findings assist in providing a detailed clinical picture, which is important for ongoing genetic clinical trials.

scholarly journals About estimation of base station output power in GSM like systems under real conditions

2020 ◽  
Vol 30 (1) ◽  
pp. 109-119
Author(s):  
Aleksandar Lebl ◽  
Dragan Mitic ◽  
Zarko Markov ◽  
Verica Vasiljevic
Keyword(s):  
Computer Simulation ◽  
Output Power ◽  
Mobile User ◽  
Base Station ◽  
Cumulative Distribution ◽  
Real Case ◽  
The Real ◽  
The Mean

The output power of traffic channels in one cell of GSM like systems is estimated in this paper. We consider the real case: the number of users is much higher than the number of channels, the output power of one channel depends on the cube of the distance between a mobile user and the base station, and the distribution of users in the cell is uniform. We derive the expressions for cumulative distribution of output power of one channel and for the mean output power of the whole base station. Results of the calculation are confirmed by computer simulation.

scholarly journals LCA-Based Investigation of Environmental Impacts for Novel Double-Beam Floor System Subjected to High Gravity Loads

2020 ◽  
Vol 12 (21) ◽  
pp. 9193
Author(s):  
Insub Choi ◽  
JunHee Kim ◽  
DongWon Kim
Keyword(s):  
Global Warming ◽  
Environmental Impacts ◽  
Environmental Performance ◽  
Construction Materials ◽  
Structural Effect ◽  
Structural Systems ◽  
High Gravity ◽  
Underground Structures ◽  
Double Beam ◽  
Floor System

In populated downtown areas, a floor system with secured environmental performance is needed to reduce greenhouse gases (GHGs) and global warming problems related to buildings. This study aims to assess environmental impacts on a novel double-beam floor system subjected to high gravity loads. Life cycle assessment (LCA) was conducted to investigate the environmental impacts on the reduction in construction materials by calculating global warming potential (GWP) in the structural design phase. For different structural systems, the environmental performance was compared based on the GWP, and the contributions of structural elements to the GWP in each structural system were analyzed. The rotational constraints induced by the beam-end concrete panel can significantly reduce the GWP of the double-beam floor system by up to 13.8% compared to the conventional beam-girder system. Thus, the double-beam floor system reinforced with the concrete panel can be a candidate for eco-friendly structural systems in underground structures requiring high gravity loads. This result provides valuable findings that the structural effect on the rotational constraint of the concrete panel was quantitatively evaluated by converting it into an environmental impact.

scholarly journals The Effects of Courtyards on the Thermal Performance of a Vernacular House in a Hot-Summer and Cold-Winter Climate

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1042 ◽  
Author(s):  
Shimeng Hao ◽  
Changming Yu ◽  
Yuejia Xu ◽  
Yehao Song
Keyword(s):  
Solar Radiation ◽  
Thermal Performance ◽  
Natural Ventilation ◽  
Field Measurements ◽  
Ground Level ◽  
Active Role ◽  
Thermal Mass ◽  
Cold Winter ◽  
Winter Climate ◽  
Climate Zones

Achieving comfort in hot summer and cold winter (HSCW) climate zones can be challenging, since the climate is characterized by high temperatures in the summer and relatively colder temperatures in the winter. Courtyards, along with other semi-open spaces such as verandas and overhangs, play an important role in mitigating outdoor climate fluctuations. In this research, the effects of courtyards on the thermal performance of vernacular houses in HSCW climate zones were studied via field measurements and computational fluid dynamics (CFD) models. The selected courtyard house was a representative vernacular timber dwelling situated in the southeast of Chongqing, China. The indoor and outdoor air temperature measurements revealed that the courtyard did play an active role as a climatic buffer and significantly reduced the temperature’s peak value in the summer, while during the winter, the courtyard prevented the surrounding rooms from receiving direct solar radiation, and thus to some extent acted as a heat barrier. The contributions of thermal mass are quite limited in this area, due to insufficient solar radiation in winter and general building operations. The natural ventilation mechanism of courtyard houses in HSCW zones was further studied through CFD simulations. The selected opened courtyard was compared to an enclosed structure with similar building configurations. The airflow patterns driven by wind and buoyancy effects were first simulated separately, and then together, to illustrate the ventilation mechanisms. The simulation results show that the courtyard’s natural ventilation behavior benefited from the proper openings on ground level.

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