Linear irreversible heat engines based on the local equilibrium assumptions

We formulate an endoreversible finite-time Carnot cycle model based on the assumptions of local equilibrium and constant energy flux, where the efficiency and the power are expressed in terms of the thermodynamic variables of the working substance. By analyzing the entropy production rate caused by the heat transfer in each isothermal process during the cycle, and using an endoreversible condition applied to the linear response regime, we identify the thermodynamic flux and force of the present system and obtain a linear relation that connects them. We calculate the efficiency at maximum power in the linear response regime by using the linear relation, which agrees with the Curzon-Ahlborn efficiency known as the upper bound in this regime. This reason is also elucidated by rewriting our model into the form of the Onsager relations, where our model turns out to satisfy the tight-coupling condition leading to the Curzon-Ahlborn efficiency.Comment: 12 pages, 1 figur

Onsager coefficients of a finite-time Carnot cycle

We study a finite-time Carnot cycle of a weakly interacting gas which we can regard as a nearly ideal gas in the limit of $T_\mathrm{h}-T_\mathrm{c}\to 0$ where $T_\mathrm{h}$ and $T_\mathrm{c}$ are the temperatures of the hot and cold heat reservoirs, respectively. In this limit, we can assume that the cycle is working in the linear-response regime and can calculate the Onsager coefficients of this cycle analytically using the elementary molecular kinetic theory. We reveal that these Onsager coefficients satisfy the so-called tight-coupling condition and this fact explains why the efficiency at the maximal power $\eta_\mathrm{max}$ of this cycle can attain the Curzon-Ahlborn efficiency from the viewpoint of the linear-response theory

Compatibility of Carnot efficiency with finite power in an underdamped Brownian Carnot cycle in small temperature-difference regime

We study the possibility of achieving the Carnot efficiency in a finite-power underdamped Brownian Carnot cycle. Recently, it was reported that the Carnot efficiency is achievable in a general class of finite-power Carnot cycle in the vanishing limit of the relaxation times. Thus, it may be interesting to clarify how the efficiency and power depend on the relaxation times by using a specific model. By evaluating the heat-leakage effect intrinsic in the underdamped dynamics with the instantaneous adiabatic processes, we demonstrate that the compatibility of the Carnot efficiency and finite power is achieved in the vanishing limit of the relaxation times in the small temperature-difference regime. Furthermore, we show that this result is consistent with a trade-off relation between power and efficiency by explicitly deriving the relation of our cycle in terms of the relaxation times

Influential information and factors for social acceptance of CCS: The 2nd round survey of public opinion in Japan

AbstractA public survey was conducted concerning carbon capture and storage technology (CCS) in the months of February and April 2007 in Japan, Previously another CCS survey took place in December 2003, and a set of the questions asked in the 2007 survey were purposely the same as that used in the 2003 survey, Japanese adults were randomly selected to answer a questionnaire either in printed format or in online format. Several versions of the questionnaire were used, and each contained a different educational part, imparting relevant CCS information. 334 people successfully responded to our paper survey in Tokyo and Sapporo while 2156 people completed our online survey across the nation. The questionnaire for the survey contained 5 sets of different information package on CCS and questions asking pros and cons on CCS implementation to analyze influence of information provided on CCS.Based on the results of survey we found: that not many people still know about CCS. Those who have knowledge on CCS show a preference for CCS implementation, however; preference was decreased after obtaining information which we considered was neutral on CCS. These results suggest a possibility that information on negative aspects of CCS (risks, etc.) would not be well known in the general public. We also found that preference for CSS decreased slightly after providing different information on CCS to respondents in the group with the newspaper articles which we considered neutral in comparison with other groups. The newspaper articles contained the information on negative opinions against CCS besides risk-related information as well as information based on an IPCC Special Report: it is assumed that such negative opinions may have influenced opinion formation of respondents. Since CCS is new technology, information about how other people or entities evaluate CCS would influence public opinion. In the sub-sample provided with industrial and natural analogues of preference on geological storage, the views were slightly more positive about CSS in comparison with reported opinions of other groups. This implies information on natural or industrial analogue would help manage perception of risk in a positive way.The result of path analysis to data of a public survey identified four factors, (1) risks and leakage, (2) effectiveness of CCS, (3) responsibility, and (4) fossil fuel use. We found that the factor of understanding the effectiveness of CCS is most positively influential for general acceptance of CCS. I Implementation of geological storage and the factor of risks and leakage become much more influential negatively in the implementation of geological storage compared to general acceptance of CCS, implying that implementation of CC2 geological storage also needs careful communication of risk

Endothelin as a local regulating factor in the bovine oviduct

Endothelin (EDN) is a possible regulating factor of oviductal motility, which is important for the transport of gametes and embryo. To clarify the factors that control the secretion of EDN in the bovine oviduct, the expression of EDNs, EDN-converting enzymes (ECEs) and EDN receptors (EDNRs) were investigated. All isoforms of EDN (EDN1-3), ECE (ECE1 and ECE2) and EDNR (EDNRA and EDNRB) were immunolocalised in the epithelial cells of the ampulla and the isthmus. EDNRs were also immunolocalised in smooth-muscle cells. The mRNA expression of EDN2 and ECE2 was higher in cultured ampullary oviductal epithelial cells than in isthmic cells. The expression of EDN1, EDN2 and ECE2 in the ampullary tissue was highest on the day of ovulation. Oestradiol-17β increased EDN2 and ECE1 expression, while progesterone increased only ECE1 expression in cultured ampullary epithelial cells. These results indicate that EDNs are produced by epithelial cells and their target site is smooth-muscle and epithelial cells, and suggest that ovarian steroids are regulators of endothelin synthesis in ampullary oviductal epithelial cells

Aspects of advanced beginner’s reflection on their experience in clinical practice: Analysis of interviews with post-graduate nurses in third years

This study investigated the aspects of reflection on clinical practice of advanced beginners and examined factors that facilitate reflection. We conducted semi-structured individual interviews with selected post-graduate third year nurses who took a reflection training course at Tottori University Hospital. The data were analyzed using a qualitative synthesis method. Advanced beginners made use of their learning experience in reflection, kept in mind “independent learning”, and deepened their own reflection with the support of senior nurses in“ a safe place to talk”．Reflection provided“ deeper self-understanding” and“ giving new meaning through others’ involvement” and advanced beginners gained“ a sense of growth” by applying what they learned to “returning to practice”．In addition, through the role of preceptor, advanced beginners were able to experience “going back to basics” and remember the learning from past experiences, which led to “return to practice”．Also, advanced beginners tried to provide “a safe place to talk” for beginners. In order to promote reflection among advanced beginners, it was suggested that it is necessary to create an image of a target nurse, the presence of others who support reflection, the workplace culture in providing a safe place to talk, and learning reflection from basic nursing education

Diagnostic value of texture analysis of apparent diffusion coefficient maps for differentiating fat-poor angiomyolipoma from non-clear-cell renal cell carcinoma

Purpose: To investigate the feasibility of texture analysis of apparent diffusion coefficient (ADC) maps for differentiating fat-poor angiomyolipomas (fpAMLs) from non-clear-cell renal cell carcinomas (non-ccRCCs). Methods: In this bi-institutional study, we included two consecutive cohorts from different institutions with pathologically confirmed solid renal masses: 67 patients (fpAML = 46; non-ccRCC = 21) for model development and 39 (fpAML = 24; non-ccRCC = 15) for validation. Patients underwent preoperative magnetic resonance imaging (MRI), including diffusion-weighted imaging. We extracted 45 texture features using a software with volumes of interest on ADC maps. Receiver operating characteristic curve analysis was performed to compare the diagnostic performance between the random forest (RF) model (derived from extracted texture features) and conventional subjective evaluation using computed tomography and MRI by radiologists. Results: RF analysis revealed that grey-level zone length matrix long-zone high grey-level emphasis was the dominant texture feature for diagnosing fpAML. The area under the curve (AUC) of the RF model to distinguish fpAMLs from non-ccRCCs was not significantly different between the validation and development cohorts (p = .19). In the validation cohort, the AUC of the RF model was similar to that of board-certified radiologists (p = .46) and significantly higher than that of radiology residents (p = .03). Conclusions: Texture analysis of ADC maps demonstrated similar diagnostic performance to that of board-certified radiologists for discriminating between fpAMLs and non-ccRCCs. Diagnostic performances in the development and validation cohorts were comparable despite using data from different imaging device manufacturers and institutions

Spared nerve injury後のマウス後根神経節におけるNGFとBDNFの発現

Neuropathic pain is initiated by a primary lesion in the peripheral nervous system and spoils quality of life. Neurotrophins play important roles in the development and transmission of neuropathic pain. There are conflicting reports that the dorsal root ganglion (DRG) in an injured nerve contribute to neuropathic pain, whereas several studies have highlighted the important contribution of the DRG in a non-injured nerve. Clarifying the role of neurotrophins in neuropathic pain is problematic because we cannot distinguish injured and intact neurons in most peripheral nerve injury models. In the present study, to elicit neuropathic pain, we used the spared nerve injury (SNI) model, in which injured DRG neurons are distinguishable from intact ones, and mechanical allodynia develops in the intact sural nerve skin territory. We examined nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) expression in the DRGs of SNI model mice. NGF and BDNF levels increased in the injured L3 DRG, while NGF decreased in the intact L5 DRG. These data offer a new point of view on the role of these neurotrophins in neuropathic pain induced by peripheral nerve injury.博士（医学）・甲第698号・平成31年3月15日© 2018 Elsevier B.V. All rights reserved