Article
Construction & Building Technology
S. K. Khattri, T. Log, A. Kraaijeveld
Summary: This study introduces a novel analytical model for determining the critical ventilation velocity in tunnel fire safety, where the heat release rate and tunnel height are the key factors. By conducting highly accurate simulations of small-scale tunnel fires and analyzing data, a correlation between these two factors is identified. The new model shows the transition of critical ventilation velocity with heat release rates and establishes the critical velocity becoming constant at higher heat release rates.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2021)
Article
Construction & Building Technology
Haiyong Cong, Mingshu Bi, Jingjie Ren, Bei Li, Yubo Bi, Wei Gao
Summary: In this study, experiments were conducted to investigate the effectiveness and stable heat extraction performance of a board-coupled shaft (BCS) in deep buried tunnels. The results showed that the BCS was effective and had stable heat extraction performance. This study provided empirical correlations and an analytical solution for predicting temperature difference and heat extraction rate in the BCS under different conditions. It contributes positively to the application of natural ventilation with vertical shafts in deep buried tunnels.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2022)
Article
Thermodynamics
Shuangyang Li, Gen Li, Erfeng Ou, Chong Wang
Summary: When a high-speed train passes through a tunnel, it disrupts the airflow and causes heat and mass transfer, which can lead to permafrost thawing and decreased tunnel safety.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Construction & Building Technology
Zixin Yang, Yunan Tu, Haoyan Ma, Xiaotong Yang, Chao Liang
Summary: A novel double-duct ventilation system, which combines the advantages of an exhaust air heat recovery system and a perforated duct ventilation system, is proposed in this study. The system can improve indoor environment and ventilation performance in poultry buildings.
BUILDING AND ENVIRONMENT
(2022)
Article
Construction & Building Technology
Liang Yi, Shihan Lan, Xiaofei Wang, Rongwei Bu, Jiaming Zhao, Yang Zhou
Summary: The emergence of inclined tunnels under natural ventilation has raised new fire safety concerns. The smoke movement in these tunnels is influenced by the chimney effect caused by the shaft and downstream tunnel. The temperature distribution in inclined tunnels differs from that in horizontal tunnels, warranting further study. Various conditions were tested in a model inclined tunnel with a single shaft to investigate temperature distribution characteristics. In this study, longitudinal air inlet velocity was used instead of longitudinal ventilation wind velocity. The results showed that fire source location, shaft height, and tunnel slope have a significant effect on the air inlet velocity. Based on previous theories and nondimensional analysis, formulas for the dimensionless longitudinal inlet air velocity and maximum smoke temperature distribution under the ceiling were proposed, which were consistent with simulation results. Reduced-scale experiments were conducted to validate the numerical simulation results, with an error range of less than 20%.
Article
Medicine, General & Internal
Kamini Dangat, Sanjay Gupte, Girija Wagh, Sanjay Lalwani, Karuna Randhir, Shweta Madiwale, Hemlata Pisal, Vrushali Kadam, Shridevi Gundu, Nomita Chandhiok, Bharati Kulkarni, Sadhana Joshi, Caroline Fall, Harshpal Singh Sachdev
Summary: This study aimed to evaluate the trimester specific gestational weight gain (GWG) in Indian pregnant women and compare it with international and Indian reference data. The study found that Indian women had lower GWG compared to international standards, but higher GWG compared to Indian reference data. Maternal BMI, age, parity, hemoglobin concentrations, and height were found to be associated with GWG.
FRONTIERS IN MEDICINE
(2022)
Article
Thermodynamics
Yapeng Wang
Summary: This study investigates how to reduce the high-temperature environmental hazards caused by the release of heat during concrete hydration in tunnel construction by controlling ventilation speed and temperature. The results show that increasing ventilation speed and decreasing ventilation temperature can effectively lower the temperature in the tunnel.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Chemistry, Analytical
Wentian Shang, Lijun Deng, Jian Liu
Summary: This study proposes a method for identifying air-door opening and closing using a single wind-velocity sensor, and demonstrates its superior performance through experiments. By analyzing the global features and fluctuation features of wind-velocity data, and utilizing a machine learning model for classification, it is able to accurately identify air-door opening and closing.
Article
Construction & Building Technology
Shihao Wen, Junjie Liu, Fan Zhang, Jing Xu
Summary: This paper optimizes traditional damper measurement equipment through numerical simulation and experimental verification, solving the problem of coupling effect between local components on the measurement results. It proposes a novel torque damper that achieves accurate air volume monitoring.
BUILDING AND ENVIRONMENT
(2022)
Article
Engineering, Civil
Kaiming Zhao, Yanping Yuan, Fujian Jiang, Xiaoling Cao
Summary: This study investigates the distribution and evolution of the thermal-humidity coupling field during the construction of the Sichuan-Tibet railway tunnels. Ventilation measures are proposed based on the evaluation of heat index (HI). The findings provide guidance for better understanding and addressing the high temperature-humidity environment in tunnel construction.
Article
Thermodynamics
Jinnan Guo, Angui Li, Chi Zhang, Jiaxing Li, Jigang Che, Jing Xiong, Xinqi Jiao
Summary: A heat transfer model was established to analyze the cooling or preheating performance of underground traffic tunnels, using the energy conservation law, boundary layer theory, and field measurement. Field tests showed that the air temperature in the tunnel fluctuated harmonically with time, with decreasing amplitude along the tunnel. The convective heat transfer coefficients were determined under different conditions, and the effective and optimal heat transfer lengths of the tunnel were calculated. This research provides theoretical support for underground traffic tunnels as natural air conditioners.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Veterinary Sciences
Joaquin Araos, Luca Lacitignola, Valentina de Monte, Marzia Stabile, Ian Porter, Daniel E. Hurtado, Agustin Perez, Antonio Crovace, Salvatore Grasso, Manuel Martin-Flores, Francesco Staffieri
Summary: This study found that body fat percentage affects lung function and the respiratory system in obese dogs, who often have extensive areas of hypo-aerated lungs. Ventilation protocols based on ideal body weight may be more beneficial for obese dogs in terms of lung deformation and airway pressure.
FRONTIERS IN VETERINARY SCIENCE
(2021)
Article
Construction & Building Technology
Aleksandar Jankovic, Francesco Goia
Summary: This paper investigates and quantifies the interplay between mechanical ventilation rate and operation of venetian blinds in determining the performance of a single-story double skin facade. The study results show that the control of the facade's performance may change with the seasons, and airflow rates and venetian blinds can play different roles depending on the boundary conditions and target performance. The paper also provides recommendations for the operation of the double skin facade.
ENERGY AND BUILDINGS
(2022)
Article
Engineering, Civil
Hu Li, Hong Han, Fuchuan Li, Yibiao Gao, Jili Qin, Shujing Chen, Wenjun Lei, Jingqian Wang
Summary: By analyzing the air velocity distribution and ventilation volume at the station, it is found that the air velocity distribution at the controllable vents is uneven and can be divided into four stages, with high velocities in the third and fourth stages. The ventilation volume under Mode 2 does not meet the station's requirements, and it is recommended to only open the controllable vents on one side of the platform.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2022)
Article
Engineering, Industrial
Xiaoqin Hu
Summary: The study found that increasing longitudinal ventilation velocity in tunnel fires can linearly increase the heat release rate, with the growth rate linearly correlating with fuel supply. When ventilation velocity reaches 70% of the critical velocity, the length of smoke back-layering is significantly reduced, providing a method to prevent smoke flow spreading upstream. Simulation results were compared with experimental data to evaluate the findings in the study.
Article
Agriculture, Dairy & Animal Science
A. V. Mendoza, S. Weimer, Z. Williams
Summary: This study evaluated the effectiveness of steam as an additional method for depopulation of laying hens in a cage-free aviary system. The results showed that steam alone or in combination with heat can lead to faster mortality of hens, and the distribution of carcasses varies in different tiers.
JOURNAL OF APPLIED POULTRY RESEARCH
(2024)