Inlet Flow And Aspects Of Cavitation In Centrifugal Impellers

PaperPg. 189-194.This paper describes the relationships of inlet velocity distribution, incipient cavitation and suction performance of centrifugal pumps. It also discusses, in particular, the aspects of cavitation as related to inlet reverse flow (internal recirculation). There are many ways of improving the suction performance of centrifugal pumps. Enlarging the inlet diameter or inlet angle are two of the most commonly used methods. However, this may increase the capacity at which inlet reverse flow begins. Inlet reverse flow normally starts to occur at about half of the shock-free inlet capacity, and this has no relation to the best efficiency flow. Pump total head begins to drop only during advanced cavitation, especially at partial flow operation. When the impeller is designed with a large inlet angle to improve suction performance, there is a possibility of increasing the capacity where inlet reverse flow occurs, which may even be at the best efficiency point. There are still other ways of improving suction performance without increasing the capacity at which inlet reverse flow occurs, e.g. reducing the number of blades, sharpening inlet edges, etc., and these are also referred to in this paper

The process from college to work in the 1970\u27s : Based on the reports from graduates

In the 1970\u27s, the labor market of the new college graduates changed greatly on the point of its instituiton, macro-indicator, and so on. What I wish to show in this paper are : (1) to descriibe how the new college graduates found their job at the labor market in the 1970\u27s (2) to examine what role the placement office play in the labor market. Based on the reports from graduates and the other materials published by the college and the placement office, I examined the mechanisms of the labor market and the process from college to work in the 1970\u27s

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本稿は、教職課程の入門科目である教職概論において、教職をめぐる進路選択や大学生のキャリア形成の問題がどのように取り扱われているかを、教職概論向けに刊行されているテキストを題材に検討したものである。2015 年の中央教育審議会答申を受けて、現行の教職課程においてはそれまでになかったチーム学校運営への対応を教職概論で新たに取り扱うことになった。現行教職課程の教職概論のテキスト内容を検討すると、従来から教職概論の内容を構成してきた教職の職業的特徴についての説明は依然として豊富であるものの、教職課程コアカリキュラムが求める「他の職業との比較を通して」教職の職業的特徴を理解するという点について正面から取り上げて説明しているテキストは極めて少なかった。このことから、教職概論で取り上げる科目内容が増加することで、教職概論の科目としての目的が十分に達成されなくなっている可能性が疑われる。養成と研修の役割分担という点にも視野を広げて、教職課程で何を教えるべきかの再検討が必要である

Development of transgenic male-sterile rice by using anther-specific promoters identified by comprehensive screening of the gene expression profile database ‘RiceXPro’

Because genomic selection is designed for the population breeding of allogamous species, a successive outcrossing system is required for efficient use of genomic selection in autogamous crops, such as Oryza sativa L. (rice). Transgenic and dominant male-sterility is a suitable tool for efficient outcrossing of autogamous crops. Though there have been some reports of dominant male-sterile rice developed using transgenic technology, the flowering habit was substandard. Here, to isolate promoters that, when linked to a lethal gene, induce dominant male-sterility while retaining a good flowering habit, we identified 38 candidate genes with anther-specific expression by using the ‘RiceXPro’ database. We then evaluated the abilities of the near-upstream regions of these genes to induce male-sterility when linked to the lethal gene barnase and introduced into the rice cultivar ‘Nipponbare’. Seven of the 38 promoters induced clear dominant male-sterility; promoters expressed in the later stage of anther development induced male-sterility while retaining better flowering habits when compared to ones expressed in the early stage. These seven promoters could potentially be used to facilitate development of an efficient outcross-based breeding system in rice

Low body mass index is a risk factor forimpaired endothelium-dependent vasodilation in humans: role of nitric oxide and oxidative stress

AbstractObjectivesThe purpose of this study was to evaluate the relationship between body mass index (BMI), including low BMIs, and endothelial function.BackgroundEpidemiologic study has demonstrated that not only obesity but also a low BMI may be a risk factor for cardiovascular disease.MethodsThe forearm blood flow (FBF) response to acetylcholine (ACh) and isosorbide dinitrate (ISDN) was measured in 87 healthy young men (15 low BMI, 51 normal, 14 obese, and 7 extremely obese).ResultsPlasma concentrations of 8-hydroxy-2′-deoxyguanosine and serum concentrations of malondialdehyde-modified low-density lipoprotein were higher in low BMI, obese, and extremely obese subjects than in normal subjects and were similar among the low BMI, obese, and extremely obese groups. The FBF response to ACh was greater in the normal group than in the other groups (p < 0.001), and was lower in the extremely obese group as compared with the other groups (p < 0.001). The ACh-stimulated vasodilation was similar between the low BMI group and the obese group. The ISDN-stimulated vasodilation was similar in all four groups. There were no significant differences in ACh-stimulated vasodilation between the four groups after the nitric oxide (NO) synthase inhibitor NG-monomethyl-L-arginine infusion. Co-infusion of vitamin C augmented the FBF response to ACh in low BMI, obese, and extremely obese groups—but not in normal BMI group.ConclusionsThese findings suggest that not only obesity but also a low BMI may be a risk factor for impaired endothelium-dependent vasodilation through the increased oxidative stress, leading to the reduced bioavailability of NO

Development and characterization of transgenic dominant male sterile rice toward an outcross-based breeding system

Genomic selection is attracting attention in the field of crop breeding. To apply genomic selection effectively for autogamous (self-pollinating) crops, an efficient outcross system is desired. Since dominant male sterility is a powerful tool for easy and successive outcross of autogamous crops, we developed transgenic dominant male sterile rice (Oryza sativa L.) using the barnase gene that is expressed by the tapetum-specific promoter BoA9. Barnase-induced male sterile rice No. 10 (BMS10) was selected for its stable male sterility and normal growth characteristics. The BMS10 flowering habits, including heading date, flowering date, and daily flowering time of BMS10 tended to be delayed compared to wild type. When BMS10 and wild type were placed side-by-side and crossed under an open-pollinating condition, the seed-setting rate was <1.5%. When the clipping method was used to avoid the influence of late flowering habits, the seed-setting rate of BMS10 increased to a maximum of 86.4%. Although flowering synchronicity should be improved to increase the seed-setting rate, our results showed that this system can produce stable transgenic male sterility with normal female fertility in rice. The transgenic male sterile rice would promote a genomic selection-based breeding system in rice

Large-Scale Mapping Observations of DCN and DCO+^+ toward Orion KL

We present emission maps (1.5'$\times$1.5' scale, corresponding to 0.18 pc) of the DCN ($J=2-1$) and DCO$^+$ ($J=2-1$) lines in the 2 mm band toward the Orion KL region obtained with the 2 mm receiver system named B4R installed on the Large Millimeter Telescope (LMT). The DCN emission shows a peak at the Orion KL hot core position, whereas no DCO$^+$ emission has been detected there. The DCO$^+$ emission shows enhancement at the west side of the hot core, which is well shielded from the UV radiation from OB massive stars in the Trapezium cluster. We have derived the abundance ratio of DCN/DCO$^+$ at three representative positions where both species have been detected. The gas components with $V_{\rm {LSR}} \approx 7.5-8.7$ km/s are associated with low abundance ratios of $\sim4-6$, whereas much higher abundance ratios ($\sim22-30$) are derived for the gas components with $V_{\rm {LSR}} \approx 9.2-11.6$ km/s. We have compared the observed abundance ratio to our chemical models and found that the observed differences in the DCN/DCO$^+$ abundance ratios are explained by different densities.Comment: Accepted by The Astrophysical Journal, 13 pages, 5 figures, 5 table

From University to Work III Part 2 : How Students seek for ""Good Jobs"" in Non-Selective 4-Year-Colleges

This is the second report using the same survey data for non-selective college students in business major. In this report, we analyze the process of students\u27job seeking activities. We find that the timing and kinds of job seeking activities among those students are more diverse and less standardized than those from selective colleges. This less standardized feature of activities makes the process of job search for those non-selective college students more vague and more difficult. As a result, we also find that there are students, who stop or never start job seeking