DYNAMIC RESPONSE OF THE HYGROMETER USING FINE THERMOCOUPLE PSYCHROMETER

A new method to obtain the frequency response character of the hygrometer using a fine thermocouple psychrometer by introducing the new concept, that the internal energy of the environment is constant, is presented with a practical example

BASIC EXPERIMENTS OF CS UPTAKE CAPABILITY FOR Eleocharis acicularis

Soil in the Fukushima area has been polluted with the radioactive contaminants such as Cs by the accident of Fukushima Daiichi nuclear power plant in March 2011. Remediation of soil contaminated with radioactive Cs remains one of the most important problems. Phytoremediation is an environmental remediation technique that takes advantage of plant physiology and metabolism to remove radioactive contaminants. Eleocharis acicularis is well known as heavy metal hyperaccumulator aquatic plant and expected as the strong candidate for application to Phytoremediation of polluted water and soil. In this study, a laboratory experiment was carried out to investigate the potential of E.acicularis for Phytoremediation of radioactive Cs contaminated site.The plants were grown hydroponically and placed in solutions containing Cs and K at different concentration (Cs concentration: 5 mg/L, K concentration: 0, 0.2, 2, 5, 50, 100 mg/L) in a period of 21days.In the experimental results, the highest concentration of Cs was 1560 mg/kg-DW in E. acicularis after 21 days. The concentration of Cs in plants decreased with the increasing initial concentration of K in the solution. This results indicate that E. acicularis has the ability to accumulate radioactive Cs from radioactive Cs contaminated soil and water, making it a good candidate species for radioactive Cs Phytoremediation. Keywords : Fukushima, Eleocharis acicularis, phytoremediation, C

Fatigue strength evaluation for bolt-nut connections having slight pitch difference considering incomplete threads of nut

Proceedings of 4th International Conference on Fracture Fatigue and Wear, FFW 2015, Ghent University, Belgium, 27-28 August 2015The high strength bolts and nuts are widely used in various fields. In this study the effect of slight pitch difference is considered when the nut pitch is αμm larger than the bolt pitch. In the first place, the fatigue experiment is conducted with varying pitch difference. The results show that the fatigue life is extended to about 1.5 times by introducing the suitable pitch difference under the high stress amplitude. Next, the detail observation is performed on the fractured specimens including the fractured positions and the crack configurations. It is found that the fractured positions and the crack distributions vary depending on the pitch difference. Finally, to clarify the improvement mechanism of the fatigue strength, the finite element method is applied to calculate the stress amplitude and mean stress at each bolt threads, and the incomplete threads at the nut ends are also considered to obtain the accurate analytical results

Contact Analysis and Simulation of Rolled Plastic Film Used for Roof Ventilation in Japanese Greenhouses

Greenhouses are capable of producing a variety of high-value crops year-round. A novel Japanese greenhouse design is gaining popularity because of its automated roll-up ventilation system that is integrated into the roof. However, due to the frequent movement of the roll-up system, the plastic film deteriorates rapidly and typically lasts for only three or four months. In order to better understand the film deterioration, we studied the mechanics involved at the point of contact between the film and the metal greenhouse frame. We found that film deformation and failure were closely related to stretching and creasing, and these processes were observed at the microscopic level. An experimental device was developed to further study the damage to greenhouse film due to the roll-up movement. We concluded that the reduction in film thickness due to static loading or rolling contact was the best predictor of future film damage

Stress and deformation of ceramic rolls to produce high quality zinc coated steel sheet

Several ceramic rolls can be used efficiently to produce high quality zinc coated steel sheet used for automobiles. Those ceramics rolls may provide a longer life and reduce the cost for the maintenance because of its large heat resistance and large wear resistance. One example may be seen in sink rolls used in molten zinc bath to manufacture zinc coated steel sheet. Since the rolls are subjected to large thermal stress and mechanical loading, care should be taken for the risk of fracture due to the ceramic brittleness. Moreover, since the sleeve and shafts can be connected only by using small shrink fitting ratio，another failure risk should be considered for the separation of those components [25, 26]. In this paper, therefore, the mechanical and thermal stress and separation condition will be investigated considering the separation of the connected portion. Here, by using the finite volume method the heat transfer coefficient is discussed and by using the finite element method the thermal stress is considered.12th International Conference on Damage Assessment of Structures 10–12 July 2017, Kitakyushu, Japa

Failure Analysis for Coming out of Shaft from Shrink-Fitted Ceramics Sleeve

This paper deals with failure analysis for coming out of the steel shaft from ceramic sleeve connected by shrink fitting. Only low shrink fitting ratio can be applied because of the brittleness of the ceramic sleeve. However, the steel shafts may be loosening out from the ceramic sleeve under such low shrink fitting ratio. In this study, the coming out behavior of the shaft during rotation is analyzed by the finite element method. The roller rotation is replaced by shifted load in the circumferential direction on the fixed roller. It is found that the load rotation can be approximated by the discrete load shifting at the interval angle θ0 = 12° within 1% error. The effect of the shrink fitting ratio on the coming out of the shaft is discussed as well as several other parameters, such as Young\u27s modulus of the shaft, the friction coefficient, magnitude of the load, and geometry of the shaft. Furthermore, it is found that the shear stress distribution at the shrink-fitted area may be useful for evaluating whether the coming out occurs or not

Effect of Pitch Difference on Anti-loosening Performance and Fatigue Strength for High Strength Bolts and Nuts

A slight pitch difference is considered between the bolt and nut in this study. Here, the pitch ofnut is α μm larger than the pitch of bolt. In the first place, the distance δ, of nut screwed onto bolt withoutany prevailing torque, is experimentally and analytically obtained for each level of α. Then, the relationshipbetween axial force and prevailing torque during tightening process is tested. According to the obtainedtorque-axial force relationship, for four different levels of α, the loosening experiment based on NAS3350(National Aerospace Standard) is performed, and the loosening and dropping status of the nuts areinvestigated. Considering both the anti-loosening ability and the clamping ability of the nut, the desirablerange of α is discussed. After that, according to the loosening experiment results, three levels of α areselected to make a further study about the effect of the pitch difference on the fatigue life of bolt. The fatigueexperiment is performed and the S-N curves are obtained. Finally, the finite element method is used to makea simulation of the fatigue experiment and the mean stress and stress amplitude at each thread bottom of boltare analyzed.13th International Conference on Fracture, June 16–21, 2013, Beijing, Chin

Malignant Lymphoma with Severe Infiltrative Growth into Skeletal Muscles in WBN/Kob Rats

Although spontaneously occurring neoplasms have been reported repeatedly in F344, SD and Wistar rats, which are commonly used strains for routine toxicologic and carcinogenicity studies, there are only a few reports of malignant lymphoma or lymphatic leukemia except for large granular lymphocytic leukemia (LGL) in F344 rats. Malignant lymphoma (lymphosarcoma) is thought to be uncommon in F344 rats. The authors encountered malignant lymphomas of the non-LGL leukemia type with characteristic pathologic features in WBN/Kob rats. The mean age at onset of the disease in all 13 affected rats (8 males and 5 females) was about 60 weeks. Common and characteristic clinical signs were abnormal gait with hind limb paralysis. Macroscopically, the enlargement of the lymph nodes, spleen and liver was slight to moderate. Scattered multiple white-to-gray nodules encompassed the aorta and assumed a bead-like appearance near the thoracic and lumbar vertebrae. Histopathologically, neoplastic proliferative changes were predominant in the bone marrow tissue of the entire body, and many tumor cells infiltrated the spleen and several lymph nodes. The most striking histological features were constant and severe infiltration of tumor cells in the adipose tissue and skeletal muscle adjacent the thoracic and lumber vertebrae. Immunohistochemically, all tumor cells were positive for B-cell markers (PAX-5, CD79a and CD45) and negative for CD3. From the results of immunohistochemistry and morphological examination, these tumors were diagnosed as malignant B-cell lymphomas

Intensity of singular stress fields of wedge-shaped defect in human tooth due to occlusal force before and after restoration with composite resins

Wedge-shaped defects are frequently observed on the cervical region of the human tooth. Previously, most studies explained that improper tooth-brushing causes such defects. However, recent clinical observation suggested that the repeated stress due to occlusal force may induce the formation of these wedge-shaped defects. In this study, therefore, two-dimensional human tooth models are considered with and without a wedge-shaped defect by applying the finite element method. To evaluate large stress concentrations accurately, a method of analysis is discussed in terms of the intensity of singular stress fields appearing at the tip of the sharp wedge-shaped defect. The effects of the position and direction of occlusion on the intensity of singular stress fields are discussed before and after restoration with composite resins

環境因子が健康に与える影響について インターネット調査;WDQH(Web-based Daily Questionnaire for Health)を利用した環境疫学調査

With increasing Internet coverage, the use of a web-based survey for epidemiological study is a possibility. We performed an investigation in Japan in winter 2008 using the web-based daily questionnaire for health (WDQH). The WDQH is a web-based questionnaire survey formulated to obtain information about the daily physical condition of the general public on a real-time basis, in order to study correlations between changes in physical health and changes in environmental factors. Respondents were asked whether they felt ill and had specific symptoms including fever. We analysed the environmental factors along with the health conditions obtained from the WDQH. Four factors were found to influence health: minimum temperature, hours of sunlight, median humidity and weekday or holiday. The WDQH allowed a daily health survey in the general population in real time via the Internet.博士（医学）・甲第593号・平成24年11月27日© 2013 Taylor & Francis Grou