Numerical and Experimental Analyses Examining Ozone and Limonene Distributions in Test Chamber with Various Turbulent Flow Fields

ITO, Kazuhide The Society of Air-Conditioning and Refrigerating 2008 International Journal Of Air-Conditioning and Refr Vol.16 No.3

Indoor ozone has received attention because of its well-documented adverse effects on health. In addition to the inherently harmful effects of ozone, it can also initiate a series of reactions that generate potentially irritating oxidation products, including free radicals, aldehydes, organic acids and secondary organic aerosols (SOA). Especially, ozone reacts actively with terpene. The overarching goal of this work was to better understand ozone and terpene distributions within rooms. Towards this end, the paper has two parts. The first describes the development of a cylindrical test chamber that can be used to obtain the second order rate constant $(k_b)$ for the bi-molecular chemical reaction of ozone and terpene in the air phase. The second consists of model room experiments coupled with Computational Fluid Dynamics (CFD) analysis of the experimental scenarios to obtain ozone and terpene distributions in various turbulent flow fields. The results of CFD predictions were in reasonable agreement with the experimental measurements.

Comprehensive Field Measurement of Indoor Air and Thermal Quality in Naturally Ventilated Office Building with Double-Skin Façade

Ito, Kazuhide,Shiraishi, Yasuyuki Council on Tall Building and Urban Habitat Korea 2013 International journal of high-rise buildings Vol.2 No.4

Double-Skin Facade (DSF), which is a kind of passive indoor environmental control technique, is effective way to control environmental loads while maintaining the transparency especially in perimeter zone and hence the adoption example of DSF keep increasing recently. The objective of this study was to perform a field survey of air quality environment with natural ventilation through DSF and thermal environment within office building with six stories during a mild climate period in Japan. Moreover, to understand the comprehensive environmental performance of the target building, questionnaire survey was conducted to subjectively evaluate the productivity and satisfaction with the environmental factors in office space. In this field measurement, there was a positive correlation between the DSF internal ventilation flow and the amount of solar radiation on the DSF normal surface; the primary driving force for ventilation in the DSF was considered to be the buoyancy force caused by solar radiation. The results of questionnaire survey with regard to productivity level indicated the need for improvement in the thermal (temperature) and spatial environment (room size and furniture placement).

Numerical and Experimental Analyses Examining Ozone and Limonene Distributions in Test Chamber with Various Turbulent Flow Fields

Kazuhide ITO 대한설비공학회 2008 International Journal Of Air-Conditioning and Refr Vol.16 No.3

Indoor ozone has received attention because of its well-documented adverse effects on health. In addition to the inherently harmful effects of ozone, it can also initiate a series of reactions that generate potentially irritating oxidation products, including free radicals, aldehydes, organic acids and secondary organic aerosols (SOA). Especially, ozone reacts actively with terpene. The overarching goal of this work was to better understand ozone and terpene distributions within rooms. Towards this end, the paper has two parts. The first describes the development of a cylindrical test chamber that can be used to obtain the second order rate constant (kb) for the bi-molecular chemical reaction of ozone and terpene in the air phase. The second consists of model room experiments coupled with Computational Fluid Dynamics (CFD) analysis of the experimental scenarios to obtain ozone and terpene distributions in various turbulent flow fields. The results of CFD predictions were in reasonable agreement with the experimental measurements.

Numerical Analysis of Convective Heat and Mass Transfer around Human Body under Strong Wind

Li, Cong,Ito, Kazuhide Council on Tall Building and Urban Habitat Korea 2012 International journal of high-rise buildings Vol.1 No.2

The overarching objective of this study is to predict the convective heat transfer around a human body under forced strong airflow conditions assuming a strong wind blowing through high-rise buildings or an air shower system in an enclosed space. In this study, computational fluid dynamics (CFD) analyses of the flow field and temperature distributions around a human body were carried out to estimate the convective heat transfer coefficient for a whole human body assuming adult male geometry under forced convective airflow conditions between 15 m/s and 25 m/s. A total of 45 CFD analyses were analyzed with boundary conditions that included differences in the air velocity, wind direction and turbulence intensity. In the case of approach air velocity $U_{in}=25m/s$ and turbulent intensity TI = 10%, average convective heat transfer coefficient was estimated at approximately $100W/m^2/K$ for the whole body, and strong dependence on air velocity and turbulence intensity was confirmed. Finally, the formula for the mean convective heat transfer coefficient as a function of approaching average velocity and turbulence intensity was approximated by using the concept of equivalent steady wind speed ($U_{eq}$).

Analysis of Airflow Pattern and Particle Dispersion in Enclosed Environment Using Traditional CFD and Lattice Boltzmann Methods

Inoguchi, Tomo,Ito, Kazuhide Council on Tall Building and Urban Habitat Korea 2012 International journal of high-rise buildings Vol.1 No.2

The indoor environments in high-rise buildings are generally well enclosed by defined boundary conditions. Here, a numerical simulation method based on the Lattice Boltzmann method (LBM), which aims to model and simulate the turbulent flow accurately in an enclosed environment, and its comparison with traditional computational fluid dynamics (CFD) results, are presented in this paper. CFD has become a powerful tool for predicting and evaluating enclosed airflows with the rapid advance in computer capacity and speed, and various types of CFD turbulence modeling and its application and validation have been reported. The LBM is a relatively new method; it involves solving of the discrete Boltzmann equation to simulate the fluid flow with a collision model instead of solving Navier-Stokes equations. In this study, the LBM-based scheme of flow pattern and particle dispersion analyses are validated using the benchmark test case of two- and three-dimensional and isothermal conditions (IEA/Annex 20 case); the prediction accuracy and advantages are also discussed by comparison with the results of CFD.

Computational analysis of ultrafine and fine particle deposition mechanisms in human lower airway

Nguyen Dang Khoa,Kazuhide Ito 한국전산유체공학회 2022 한국전산유체공학회 학술대회논문집 Vol.2022 No.10

Ajoy Prasad Shetty

Go Kubota,Hiroto Kamoda,Sumihisa Orita,Kazuhidee Inage,Michihiro Ito,Masaomi Yamashita,Takeo Furuya,Tsutomu Akazawa,Yasuhiro Shiga,Seiji Ohtori 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.1

Study Design: Retrospective case series. Purpose: To examine the efficacy of platelet-rich plasma (PRP) for bone fusion in transforaminal lumbar interbody fusion (TLIF) using local bone grafting. Overview of Literature: Several authors have reported the efficacy of PRP for bone union in animal models. However, the use of PRP for bone fusion in TLIF surgery has not been fully explored. Methods: Twenty patients underwent single-level TLIF surgery because of L4 spondylolisthesis. An interbody fusion cage and local bone were used in nine patients (control group) and an interbody fusion cage, local bone, and PRP were used in 11 patients (PRP group). PRP was prepared from the patients’ blood samples (400 mL) immediately before surgery. The duration of bone union and postoperative bone fusion rate were assessed using plain radiography at every 3 months postoperatively and computed tomography at 12 or 24 months postoperatively, respectively. Lower back pain, leg pain, and leg numbness were evaluated using the visual analog scale preoperatively and at 3, 6, 12, and 24 months postoperatively. Results: The platelet count was 8.7 times higher in PRP than in blood. The bone union rate was significantly superior in the PRP group than in the control group (91% and 77%, respectively; p =0.035), whereas the average duration of bone union was not significantly different between the groups (7.7±0.74 and 10.0±2.00 months, respectively; p =0.131). There was no significant difference in lower back pain, leg pain, and leg numbness in both groups during follow-up (p >0.05). Conclusions Our study suggests that the use of PRP in TLIF surgery increases bone fusion rate.

Freeze-Dried Human Platelet-Rich Plasma Retains Activation and Growth Factor Expression after an Eight-Week Preservation Period

Yasuhiro Shiga,Go Kubota,Sumihisa Orita,Kazuhide Inage,Hiroto Kamoda,Masaomi Yamashita,Toru Iseki,Michihiro Ito,Kazuyo Yamauchi,Yawara Eguchi,Takeshi Sainoh,Jun Sato,Kazuki Fujimoto,Koki Abe,Hirohito 대한척추외과학회 2017 Asian Spine Journal Vol.11 No.3

Study Design: Controlled laboratory study. Purpose: This study aimed to evaluate the efficacy of platelet-rich plasma (PRP) stored at room temperature (RT), frozen, or after freeze-drying. Overview of Literature: PRP enriches tissue repair and regeneration, and is a novel treatment option for musculoskeletal pathologies. However, whether biological activity is preserved during PRP storage remains uncertain. Methods: PRP was prepared from blood of 12 healthy human volunteers (200 mL/person) and stored using three methods: PRP was stored at RT with shaking, PRP was frozen and stored at –80°C, or PRP was freeze-dried and stored at RT. Platelet counts and growth factor content were examined immediately after preparation, as well as 2, 4, and 8 weeks after storage. Platelet activation rate was quantified by flow cytometry. Results: Platelet counts were impossible to determine in many RT samples after 2 weeks, but they remained at constant levels in frozen and freeze-dried samples, even after 8 weeks of storage. Flow cytometry showed approximately 80% activation of the platelets regardless of storage conditions. Almost no growth factors were detected in the RT samples after 8 weeks, while low but significant expression was detected in the frozen and freeze-dried PRP. Over time, the mean relative concentrations of various growth factors decreased significantly or disappeared in the RT group. In the frozen group, levels were maintained for 4 weeks, but decreased significantly by 8 weeks (p <0.05). The freeze-dried group maintained baseline levels of growth factors for the entire 8-week duration. Conclusions: Freeze-drying enables PRP storage while maintaining bioactivity and efficacy for extended periods.

Three-Dimensional Modeling and Computational Fluid Dynamics Analysis for Ventilation in Clothing

Sena Hyodo,Sung-Jun Yoo,Kazuhide Ito 한국전산유체공학회 2022 한국전산유체공학회 학술대회논문집 Vol.2022 No.10

Cacao bean husk: an applicable bedding material in dairy free-stall barns

Akira Yajima,Hisashi Owada,Suguru Kobayashi,Natsumi Komatsu,Kazuaki Takehara,Maria Ito,Kazuhide Matsuda,Kan Sato,Hisao Itabashi,Satoshi Sugimura,Shuhei Kanda 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.7

Objective: The objectives of the study were to assess the effect of cacao bean husk as bedding material in free-stall barn on the behavior, productivity, and udder health of dairy cattle, and on the ammonia concentrations in the barn. Methods: Four different stall surfaces (no bedding, cacao bean husk, sawdust, and chopped wheat straw) were each continuously tested for a period of 1 week to determine their effects on nine lactating Holstein cows housed in the free-stall barn with rubber matting. The lying time and the milk yield were measured between d 4 and d 7. Blood samples for plasma cortisol concentration and teat swabs for bacterial counts were obtained prior to morning milking on d 7. The time-averaged gas-phase ammonia concentrations in the barn were measured between d 2 and d 7. Results: The cows spent approximately 2 h more per day lying in the stalls when bedding was available than without bedding. The milk yield increased in the experimental periods when cows had access to bedding materials as compared to the period without bedding. The lying time was positively correlated with the milk yield. Bacterial counts on the teat ends recorded for cows housed on cacao bean husk were significantly lower than those recorded for cows housed without bedding. Ammonia concentration under cacao bean husk bedding decreased by 6%, 15%, and 21% as compared to no bedding, sawdust, and chopped wheat straw, respectively. The cortisol concentration was lowest in the period when cacao bean husk bedding was used. We observed a positive correlation between the ammonia concentrations in the barn and the plasma cortisol concentrations. Conclusion: Cacao bean husk is a potential alternative of conventional bedding material, such as sawdust or chopped wheat straw, with beneficial effects on udder health and ammonia concentrations in the barns.