Chubu University Research Articles

Construction of radiation protection training program for nurses using virtual reality

There are also risks associated with X-rays as they are a form of radiation and although precautions are taken to protect patients, exposure of radiology personnel can be neglected. Senior Assistant Professor Tomihiko Daioku, from Chubu University, has been working to educate nurses about radiation in the workplace as many nurses may not have important knowledge about radiation and correct radiation protection methods and experience fear and anxiety about exposure. Given that nursing training courses are intensive, opportunities to learn about radiation are limited. Daioku believes it is vital to provide nurses with more education on radiology and equip them to stay safer in the workplace and has been developing an education programme to raise awareness of radiation and precautionary measures that can be taken by nurses. He has been using projection mapping and VR as useful educational tools for understanding the characteristics of invisible radiation, ensuring the teachings are fun and experience-based. As Daioku found that clinical experience was essential in recalling situations within the VR environment, he has been focusing on practising nurses, building a programme based on Kolbâ–™s experiential learning model. He has confirmed the efficacy of his teaching materials and wants to determine how to utilise these for nursing students without any clinical experience, with the additional hurdle that they have heavy workloads and therefore little time for lengthy education programmes.

Conference Report on the 7th International Symposium on Liquid metals Applications for fusion (ISLA-7)

Supported by the world magnetic fusion research community, a series of International Symposia on Liquid metals Applications for fusion (ISLA) have been held biannually since 2010. The 7th edition (ISLA-7) was held for the period from 12 December through 16 December 2022, at Chubu University located in Kasugai, Aichi, Japan. For the first time in the history of this series of symposia, ISLA-7 was held in a hybrid fashion, due to the COVID-19 situation. The total number of the participants was 60, 34 out of whom attended the symposium in person, and the rest participated online. As to the presentation statistics, 29 papers were presented in person, whereas 21 presentations were delivered online but real-time by the presenters in China, Spain, the UK, and the USA. Both of the presentations delivered in person and online were recorded, and the video has been shared by all participants. These participants represent 11 countries: China, Czech, Italy, Japan, Latvia, Netherlands, Russia, Thailand, the UK, and the USA. All these numbers are among the largest in this series of symposia. Covered by these presentations are; in session-2, program overviews and liquid metal research review; in session-3, liquid metal flows, and MHD issues; in session-4, liquid metal facilities; in sessions-5 and 6, liquid metal experiments and modeling; in session-7, divertor physics and heat flux mitigation; in session-8, plasma and liquid metals interactions; in session-9 liquid metal plasma-facing components, erosion, and wettability. In addition, there were an opening session whereby several opening addresses were delivered and also a closing session where all technical session summaries were presented by the respective session chairs.

Does air ionization by radon cause low-frequency atmospheric electromagnetic earthquake precursors?

The aim of this work is to study the relationship between the pre-earthquake emissions of radon and ULF/ELF (1–30 Hz) atmospheric electromagnetic radiation. The problem is considered on the example of the 2011 Tohoku earthquake. Radon, ionizing air, creates ions—centers of condensation of water vapor. As a result of condensation, heat is generated. It results in growth of air temperature and decrease in its humidity. This phenomenon serves as an indicator of air ionization. We used data from 20 Japan Meteorological Agency (JMA) weather stations located on Honshu Island to estimate any changes in temperature and humidity over ± 20 days from the date of the main shock. At the same time, we monitored the intensity and location of the source of ULF/ELF radiation using three induction magnetometers belonging to Chubu University. We compared the times and locations of observed signs of ionization and electromagnetic radiation to find out their relationship. It turned out that they are independent, since their dates and localizations do not match. In addition, we found intense ionization of the air after March 11 over a large area of Honshu Island, caused by radiative radiation from the nuclear disaster at the Fukushima Daiichi nuclear power plant. However, this phenomenon did not cause low-frequency atmospheric electromagnetic radiation either. These suggest that there is no direct relationship between air ionization and ULF/ELF radiation. This is true at least for this case, given the island nature of the land and oceanic EQs.

16] 組織内映像アーカイブのためのメタデータ構築：中部大学放送研究会番組映像の保存と利活用

16] 組織内映像アーカイブのためのメタデータ構築：中部大学放送研究会番組映像の保存と利活用

DIFFERENTIATED USING BEHAVIORS IN THE LEARNING ENVIRONMENT ACCORDING TO THE SPATIAL CONFORMATION OF LEARNING COMMONS IN UNIVERSITY

1. Objectives In Japanese universities, the realization of a new type of group learning environment, based on the use of analogic and digital media, has been promoted: Learning Commons (hereinafter, "LC"). Recently, examples of LC built separately from university library have increased. In the previous report, we conducted surveys in libraries where the reading area and the LCs are integrated, aiming to clarify the seat choice behavior of individual and group users. However, it was still to define if all the users actually choose only one of those two types, or if some of them rather choose both types. For this reason, we tried to clarify the differentiated use behavior of reading areaff and LCs, aiming to acquire a useful knowledge for future learning space planning. 2. Research method We conducted a questionnaire survey and a behavior observation survey regarding the use status (addressed to users), and a questionnaire survey regarding the facility conditions (addressed to library staff). The surveys were conducted in four Japanese universities: Sugiyama Jogakuen University, Ritsumeikan University, Chubu University, and Kyoto Sangyo University, which have different LC installation types. All of those institutions have more than 6,000 students and multiple departments. The different LC installation types have been identified as “integrated open type” (Sugiyama Jogakuen Univ.), “integrated separate type” (Ritsumeikan Univ.), “distributed combined type” (Chubu Univ.), “distributed independent type” (Kyoto Sangyo Univ.). 3. Results We noted that, as for the actual conditions, LC facilities have been built outside the library building in those universities where the number of students is larger. Our hypothesis was that most of the single users tend to chose reading areas, and that most of the group users tend to chose LC; however, the results showed that around the 50% of the plural places users tend to choose both facilities, regardless of single or group use. The analysis of this portion of users’ behavior made clear that, between the reasons of their place choice, there are the possibility of using learning tools as PCs and copy machines, and the factor of nearness (LC facilities situated near the faculty building were largely used). In the “distributed type”, a large number of users chose both reading areas and LC because of the quiet environment. From this, it can be thought that by separating LC from the library building, it becomes possible to create various acoustic environments inside the vast surface obtained. Also in the “integrated open type”, where there are no partitions between reading areas and LC, and where, within the same floor, there is a differentiation of quiet and lively spaces, many users’ purpose was “to find a quiet environment”. This behavior could only mean that the concept of “quietness” is not only linked to the absence of sound. 4. Conclusions From those considerations, it seems necessary to provide a differentiation in the sound environment of the learning spaces. Even by planning spaces where there is a sort of “noisy” acoustic condition, it becomes possible to increase the place choice factors of the users.

Inhalation of molecular hydrogen increases breath acetone excretion during submaximal exercise: a randomized, single-blinded, placebo-controlled study.

Aerobic exercise is widely accepted as a beneficial option for reducing fat in humans. Recently, it has been suggested that molecular hydrogen (H2) augments mitochondrial oxidative phosphorylation. Therefore, the hypothesis that inhaling H2 could facilitate lipid metabolism during aerobic exercise was investigated in the current study by measuring the breath acetone levels, which could be used as non-invasive indicators of lipid metabolism. This study aimed to investigate the effect of inhaling H2 on breath acetone output during submaximal exercise using a randomized, single-blinded, placebo-controlled, and cross-over experimental design. After taking a 20-minute baseline measurement, breath acetone levels were measured in ten male subjects who performed a 60% peak oxygen uptake-intensity cycling exercise for 20 minutes while inhaling either 1% H2 or a control gas. In another experiment, six male subjects remained in a sitting position for 45 minutes while inhaling either 1% H2 or a control gas. H2 significantly augmented breath acetone and enhanced oxygen uptake during exercise (P < 0.01). However, it did not significantly change oxidative stress or antioxidant activity responses to exercise, nor did it significantly alter the breath acetone or oxygen uptake during prolonged resting states. These results suggest that inhaling H2 gas promotes an exercise-induced increase in hepatic lipid metabolism. The study was approved by the Ethical Committee of Chubu University, Japan (approved No. 260086-2) on March 29, 2018.

Two-week continuous supplementation of hydrogenrich water increases peak oxygen uptake during an incremental cycling exercise test in healthy humans: a randomized, single-blinded, placebo-controlled study.

The various beneficial effects of the intake of molecular hydrogen (H2) have been demonstrated in the field of sports science. Although supplementation of H2 has been reported to increase mitochondrial metabolism in animal studies, the effects of the administration of H2 on aerobic capacity during exercise in humans are still not clear. We investigated whether a single or 2-week continuous intake of H2-rich water (HW) enhanced the aerobic capacity during incremental exercise in healthy humans. In this randomized, single-blinded, placebo-controlled experimental study, the participants performed an incremental cycling exercise to measure peak oxygen uptake and peak load before and after a single (500 mL) or a 2-week supplementation (total 5 L) of HW. In the latter experiment, the participants drank the 500 mL of HW on all weekdays (i.e., 10 times). The single intake of HW did not significantly increase peak oxygen uptake and peak load, and did not significantly alter the responses in oxidative stress, antioxidant activity, and lactate levels. However, importantly, the 2-week continuous consumption of HW significantly augmented peak oxygen uptake and tended to increase the peak load without any significant changes in lactate levels, oxidative stress, and antioxidant responses. In conclusion, the continuous supplementation of HW potentially augments the aerobic capacity, implying that continuous supplementation of H2 might help improve aerobic exercise performance and physical health. This study protocol was approved by the Ethical Committee of Chubu University (approval No. 260086-2) on March 29, 2018.

SLEEP-WAKE RHYTHM AND ENDOTHELIAL FUNCTION IN YOUNG ADULTS

Objective: Insufficient sleep or short sleep duration is a risk factor for hypertension associated with cardiovascular disease in adults. Irregular sleep-wake rhythm is common problems among university students. We investigated the effect of sleep-wake rhythm or sleep duration on endothelial function in young adults. Design and method: Twenty university students were enrolled in this study. All subjects had no history of any neurological disorder, substance abuse, head injury or major physical illness, and were not on any psychotropic medications at the time of the study. There were no problems with social life in any subjects. The Chubu University ethics committee approved all procedures associated with the study. We obtained written informed consent from each participant after fully explanation of the protocol. All subjects filled a questionnaire about their daily sleep schedule. Bedtime, wake-up time, and sleep duration were collected from this questionnaire and median of sleep time was calculated. Peak cortical oxygenated hemoglobin and integral values by a word fluency task were measured with NIRS. Brachial-ankle pulsed wave velocity (baPWV), systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were measured using a plethysmograph. Endothelium-dependent FMD was induced by reactive hyperemia, and high-resolution ultrasound with a 7.5-MHz linear array transducer was used to measure the diameter of the right brachial artery. Percent FMD was computed as: (maximum diameter-baseline diameter) / baseline diameter × 100. Total sleep time (TST) and sleep-wake rhythm were evaluated by actigraphy. Results: Percent FMD was significantly lower in irregular sleep-wake rhythm group (greater than two hours) than in non-irregular sleep-wake rhythm group. Percent FMD was significantly greater in TST < 6 hours group than in TST>6 hours group. There were no significant differences in baPWV, SBP, DBP, HR, and baseline brachial artery diameter between the two groups. Conclusions: Irregular sleep-wake rhythm or short sleep duration may play an important role in decreasing endothelial function.

The people behind the papers - Masanori Abe and Reiko Kuroda.

One of the most obvious examples of left-right asymmetry in animal bodies comes from snails: in most species or strains, the shells coil dextrally, but some coil sinistrally. The control of coiling is genetic and begins in the early embryo. Previous work has implicated the formin diaphanous in the regulation of snail shell chirality, and a new paper in Development now decisively proves its involvement, thanks to the first application of CRISPR/Cas9 gene knockouts in molluscs. We caught up with the author team behind the paper: Masanori Abe and his supervisor Reiko Kuroda, Professor at Chubu University in Japan (recently moved from Tokyo University of Science), to find out more.

Engineering Science Laboratory, College of Engineering, Chubu University

Engineering Science Laboratory, College of Engineering, Chubu University

Testing of Peltier current leads used in real electrical superconducting network

Peltier current leads (PCLs) for high-temperature superconducting (HTS) DC applications can significantly reduce heat load on the cryogenic systems and increase overall performance of the HTS equipment. In order to investigate their operational properties in real electrical network for the first time, 144 PCLs developed in Chubu University were mounted at the terminals of 500-meter long HTS DC cable facility in Ishikari, Japan. Real-time data acquisition system monitoring a large amount of data allowed us to analysis of the PCL array operation both in idle mode and under the load of up to 6 kA per cable.

中部大学大学院工学研究科 創造エネルギー理工学専攻 行本研究室

中部大学大学院工学研究科 創造エネルギー理工学専攻 行本研究室

6-4-1 中部大学におけるキャンパススマートグリッドの導入とエネルギー教育の構築(Session 6-4 エネルギーネットワーク)

6-4-1 中部大学におけるキャンパススマートグリッドの導入とエネルギー教育の構築(Session 6-4 エネルギーネットワーク)

Experimental Study on Ferromagnetic Shunt Effects on the Critical Current of BSCCO Tape in Stacked Conductors

In the 200 m high temperature superconducting (HTS) cable test facility at Chubu University constructed in 2010, a three-layer structure of the tapes in the cable is employed for obtaining the high current capacity up to 2 kA. Previous study shows that the critical current is affected by the layout of the tapes such as gaps and the current feeding mode. In the stacked tape conductors, the critical current of BSCCO tapes shows strong dependence on the current feeding directions between the tapes. The critical current is improved when the opposite-direction current is applied to them and degraded for the same-direction current feeding mode because of strong magnetic field interaction between them from the transport current in each tape. This paper presents the measurements of the critical currents of a BSCCO tape in the stacked conductors with the ferromagnetic materials. By using the ferromagnetic materials surrounding the tapes, self-field of HTS tapes is affected and their critical currents are improved by more than 10%. Ferromagnetic shunt effects on the critical current of HTS tape are reported through the magnetic field analysis.

2G09 中部大学における学生主体の標準化教育 : 環境,リスク,社会的責任の教材開発((15)グローバル化時代における工学教育-II,口頭発表)

2G09 中部大学における学生主体の標準化教育 : 環境,リスク,社会的責任の教材開発((15)グローバル化時代における工学教育-II,口頭発表)

Circulation Test of Liquid Nitrogen for Long Superconducting DC Power Transmission Lines

The pressure drop during circulation of the refrigerant limits the distance for superconducting power transmission. Evaluation of the pressure drop with respect to the flow rate of the refrigerant is crucial, particularly for long transmission lines. A circulation test, including pressure drop measurements, was performed in the sixth cooling test with the 200-m-class superconducting dc power transmission system at Chubu University (CASER-2). Pressure drops were measured in the high-flow-rate region, up to 31 L/min, to simulate 1-km-class systems, unlike those used in the first five cooling tests. A pressure drop of 12 kPa at 31 L/min for the 200-m cryogenic pipe was obtained. The obtained results were compared with the calculated results and showed good agreement. The model used for the calculation can predict the pressure drop with sufficient accuracy, making the prediction for the pressure drop for long transmission lines possible.

Thermosiphon Effect During Cooling Test of a 200 m DC HTS Cable Facility

Industrial application of HTS cables for power transmission is largely constrained by the imperfection of the cryogenic pumps that are expensive apparatuses providing additional heat load. Temperature and, consequently, density of the liquid cryogen change while it flows through the channel. If the cryogenic pipe route has enough elevation difference, this will lead to natural circulation. As a result, it may be not necessary to use pump, and the system cost and complexity will reduce significantly. The feasibility of the given approach was confirmed theoretically for various system configurations. Preliminary experiments were also carried out using 200-m dc HTS facility at Chubu University during the third and fourth cooling tests. Recently, during the sixth cooling test, the cryogenic pump was stopped intentionally. Meanwhile, the natural circulation of the liquid nitrogen was observed at flow rate of about 2 l/min, and the cable temperature remained low.

Multi-channel Data Acquisition System for a 500 m DC HTS Power Cable in Ishikari

Reduction of heat penetrating into the cryogenic region is the important method of optimization of superconducting devices. In the cases of short-range power transmission lines and compact HTS devices like magnets, the heat leakage through current leads is relatively large. In order to decrease this contribution, current leads equipped with Peltier elements can be used. The mentioned technology is being actively developed in the Chubu University. Commercial samples of Peltier current leads are installed at the terminals of 500-meter DC HTS cable in Ishikari (Hokkaido). This cable is designed for 5 kA. The inner conducting layer consists of 37 DI-BSCCO HTS tapes from Sumitomo Electric Industries, Ltd. with a critical current of 180 A; and the outer one consists of 35 tapes of the same type. Each end of the cable's tape is connected to the individual Peltier current lead. Accordingly, each of the two terminals is equipped with 72 Peltier current leads, 144 pieces in total. In order to examine behavior of the current leads in detail, each piece is supplied with two thermocouples; there are also voltage taps on feedthrough and on HTS tape end. In addition, current through Peltier current lead can be measured by means of individual current transformer. The hardware part of the data acquisition system includes four Keithley 3706A multimeters equipped with 60-channel model 3724 FET multiplexer cards. Therefore, 144 data blocks are formed. Furthermore, there are 72 measurements of a voltage drop across HTS tape. Sampling period is set to be 3 s. The program part of the data acquisition system was written using LabVIEW software solution (National Instruments Corp.).

Critical Current Enhancement of BSCCO Tapes in Stacked Conductors With Ferromagnetic Sheets

A 200-m-long high-temperature superconducting (HTS) cable for dc power transmission, called CASER-II, was constructed at Chubu University using BSCCO tapes in 2010. The critical current of HTS tapes has been extensively studied against their layouts to improve the performance of HTS tapes in the cable. The multilayer structure of the tapes is needed to obtain a high current capacity. In the stacked tape conductors, the critical current of BSCCO tapes shows strong dependence on the current feeding directions between the tapes. The critical current is improved when the opposite-direction current is applied to them and reduced for the same-direction current feeding mode because of the strong magnetic field interaction between them. By using the ferromagnetic sheets, self-field of HTS tapes will be affected and may improve their critical currents. This technical paper presents the measurements of the critical currents of BSCCO tapes in the stacked conductors covered with the ferromagnetic sheets under different current feeding modes. We will present effects on the critical current of HTS tapes of the magnetic field from the currents applied to the neighboring tapes and the ferromagnetic sheets through the magnetic field analysis.

Concept and Design of 500 Meter and 1000 Meter DC Superconducting Power Cables in Ishikari, Japan

The design and construction of two DC superconducting power cables were started in the spring of 2013 as a national project in Japan. The cable lengths are 500 and 1000 m, respectively. The project is called the Ishikari Project. Four parties, Chiyoda Corp., Sumitomo Electric, Sakura Internet, and Chubu University joined to establish a partnership. The 500-m cable will connect an Internet data center (iDC) to a large scale array of photovoltaic cells to supply dc power. During the design and the construction in the field, test benches have also been constructed to investigate the performance of the individual components of the cable system. The design value of the heat leak of the cryogenic pipe is 1.3 W/m and the experimental result is 0.7 W/m to 1.3 W/m on the test bench. The design value of the heat leak from the current lead is 35 W/kA and the experimental value is 30.5 W/kA at the rated current. Control of the thermal contraction and expansion are important to maintain cable safety and two methods are considered. Construction was started in the field in mid-May, and the 500-m cable will be completed at the end of the fiscal year 2014.