28 research outputs found
Long-term changes in summer temperature anomaly patterns in Japan since the early 20th century
The relationship between long-term variations in summer temperature in Japan since the early 20th century and the large-scale atmospheric circulation field was analysed. The combined influence of various circulation predictors on temperarure variations was analysed via a multicomponent canonical correlation analysis(CCA). The positive phase of the first CCA mode is related to a positive temperature anomaly across Japan, characterized by a weak blocking hi gh over the Okhotsk Sea, and a strong North Pac ific subtropical high (NPSH) over Japan. The positive phase of the second CCA mode corresponds to a positive temperature anomaly in southwestern Japan, and a negative anomaly in northern Japan, characterized by an anticyclonic circulation anomaly over eastern China and a cyclonic anomaly over the northwestern Pacific. By investigating the temporal changes in CCA scores, we detected an abrupt increase in the first CCA score in the early 1910s and a long-term increasing trend in the second CCA score since the early 20th centu ry. The abrupt increase in the first CCA score indicates an abrupt increase in temperature throughout Japan . By investigating changes in the circulation field associated with thisabrupt warming, we determined that intensification of zonal flow over the Okhotsk Sea was responsibl e. The increasingtrend of the second CCA score indicates an increase in the regional difference in summer temperatures between northernand somhwestern Japan. After investigating changes in the circulation field before and after the mid-20th century, we suggest that the southwestward shift of the NPSH and the weakening of anticyclonic circulation anomalies over the northwestern Pacific were responsible for this increase in the regional temperature difference
Syndiotactic- and heterotactic-specific radical polymerization of N-n-propylmethacrylamide complexed with alkali metal ions
We investigated the radical polymerization of N-n-propylmethacrylamide (NNPMAAm) in the presence of alkali metal bis(trifluoromethanesulfonyl)imides (MNTf2), in particular LiNTf2. The addition of MNTf2 led to a significant improvement in the yield and molecular weight of the resulting poly(NNPMAAm)s. Furthermore, the solvent employed influenced stereospecificity in the presence of LiNTf2. The stoichiometry of the NNPMAAm–Li+ complex appeared to be critical to determining the stereospecificity in the NNPMAAm polymerization. The 1:1-complexed monomer in protic polar solvents provided syndiotactic-rich polymers, whereas the 2:1-complexed monomer in aprotic solvents gave heterotactic-rich polymers. Stereochemical analyses revealed that m-addition by an r-ended radical was the key step in the induction of heterotactic specificity in the aprotic solvents. Spectroscopic analyses suggested that the Li+ cation played a dual role in the polymerization process, with Li+ stabilizing the propagating radical species and also activating the incoming monomer. Kinetic studies with the aid of electron spin resonance spectroscopy revealed that the addition of LiNTf2 caused a significant increase in the kp value and a decrease in the kt value. The stereoregularity of poly(NNPMAAm)s was found to influence the phase transition behavior of their aqueous solutions. In a series of syndiotactic-rich polymers, the phase-transition temperature decreased gradually with increase in rr triad content. Furthermore, heterotactic-rich poly(NNPMAAm) exhibited high hysteresis, which increased in magnitude with increasing mr triad content
Reconstruction of Winter Temperature since the 1830s in Kawanishi Based on Historical Weather Documents
In the present study, we estimated the winter temperature variations from 1830/31 to 2008/09 in the town of Kawanishi in the southern part of Yamagata prefecture using daily weather reports and observa tions documented in an old personal diary. Using historical weather reports, we computed the snowfall rate (percentage ratio of snowfall days to the total number of precipitation days) for each winter during the study period. Then, mean winter temperatures in Kawanishi were estimated using a simple linear regression analysis based on the relationship between the mean winter temperature and snowfall rate, which was computed from historical weather reports. The results of this analysis showed that there were several warm winters in the late 19th century. The warm winters were observed in a period extending from the late 1840s to the early 1850s, and a period in the late 1860s. The results also showed that the temperatures in those warm winters were similar to the average winter temperature for the period 1970/71-1999/2000. By comparing the time series of estimated temperatures to those of long-term historical instrumental temperature data since the late 19th century, we found that the variation in the estimated temperature correlated well with that of the instrumental temperature data. This indicates that the estimated results in the present study are highly reliable
Thermally induced cationic polymerization of isobutyl vinyl ether in toluene in the presence of solvate ionic liquid
Radical polymerization of isobutyl vinyl ether (IBVE) was attempted with the aid of the interaction between the corresponding propagating radical and lithium cation (Li+). LiN(SO2CF3)2 (LiNTf2) and ester compounds, such as methyl methacrylate (MMA) and vinyl acetate (VAc), were added as a Li+ source and dissolving agent for LiNTf2, respectively. Homopolymers of cationically polymerizable IBVE were obtained despite the presence of radically polymerizable monomers such as MMA and VAc. Contrary to our expectation, the polymerization proceeded via not a radical mechanism but a cationic mechanism. However, this cationic polymerization was found to be unusual. In particular, the polymer yield increased with the polymerization temperature; successful polymerization was observed at 100 °C, whereas no polymerization occurred at lower temperatures such as at 0 °C. The behavior of the present system was therefore defined as “thermally induced cationic polymerization”. The mechanism of thermally induced cationic polymerization is still not clear, but it is assumed that the propagating cation is markedly stabilized through its interaction with the solvate ionic liquid formed between LiNTf2 and the Lewis base
Reconstruction of July Temperature Variations since the 1830s in Kawanishi Based on Historical Weather Documents
In the present study, we estimated the July maximum temperature variations from 1830 to 2011 in the town of Kawanishi in the southern part of Yamagata prefecture using daily weather reports and observa tions documented in an old personal diary. Using historical weather reports, we computed the number of "fine-weather" days for each July during the study period. Then, July maximum temperatures in Kawanishi were estimated using a simple linear regression analysis based on the relationship between the July maximum temperature and number of "fine-weather" days, computed from historical weather reports. By com paring the time series of estimated temperatures with those of historical instrumental temperature data in the late 19th century, we found that the variation in the estimated temperature correlated well with that of the instrumental temperature data. This indicates that the estimated results in the present study are highly reliable. The results of this analysis showed that there were cool periods in the 1830s, 1860s, 1900s, and a period extending from the 1980s to the early 1990s. Those cool periods in the 1830s, 1860s, and 1900s coincided with poor rice harvests and severe famines in northern Japan. Warm summers were observed in the 1850s, a period extending from the 1870s to 1880s, and 1920s. We found that temperatures in the early 1850s were similar to those of warm summers in the late 20th century
Stereolithographic biomodeling of equine ovary based on 3D serial digitizing device
The 3D internal structure microscopy (3D-ISM) was applied to the equine ovary, which possesses peculiar structural characteristics. Stereolithography was applied to make a life-sized model by means of data obtained from 3D-ISM. Images from serially sliced surfaces contributed to a successful 3D reconstruction of the equine ovary. Photopolymerized resin models of equine ovaries produced by stereolithography can clearly show the internal structure and spatial localizations in the ovary. The understanding of the spatial relationship between the ovulation fossa and follicles and/or corpora lutea in the equine ovary was a great benefit. The peculiar structure of the equine ovary could be thoroughly observed and understood through this model
Dealing with Disasters: Environmental History of Early Modern Cities (Edo, Istanbul, London, Pest, and Prague)
List of ContributorsForeword Introduction The Ordinary and the Extraordinary in Early Modern Cities / Koichi Watanabe trans. by Hisashi Kuboyama Part I: Aspects of Urban Disasters Chapter 1 Typhoon Damage in 1856 Edo: Integrating Archaeology, Climatology and History / Koichi Watanabe, Junpei Hirano, Hiroyuki Ishigami, and Masumi Zaiki trans. by Hisashi Kuboyama Chapter 2 The Great Flood in Pest, 1838 / Csaba Katona Chapter 3 Fire Disasters in European Cities, 1600-1800 David Garrioch Comment Disaster of Beijing in the Qing Dynasty 1644-1911 / Akira Horichi trans. by Yoko Onodera Part II: Disasters and Responses Chapter 4 Prevent the Big Water. Flood Control Measures in Prague (Bohemia) Issued by Public Administrative Bodies in Late 18th Century / Ondřej Hudeček Chapter 5 Citizens’ Awareness of Firefighting in Edo: Analysing Eighteenth-Century Textbooks on Firefighting / Reiji Iwabuchi trans. by Hisashi Kuboyama Part III: Infrastructure as Artificial Nature Chapter 6 The Ordinary Made Extraordinary: The Archaeology of Water Management in a Global City / Sophie Jackson Chapter 7 Management and Civil Engineering of Urban Water Supply and Sewage System in Edo as Seen from Archaeological Excavation / Hiroyuki Ishigami trans. by Mina Ishizu Chapter 8 Dredging the Edo Castle\u27s Moat: a Case of the Okayama-Domain Dredging in 1765 / Reiji Iwabuchi trans. by Naoko Nomoto Chapter 9 Canal, Dredging and Sedimentation in the Lowland Area of East Edo: Considering Physical and Spatial Characteristics of Canals in a Historical Context / Genki Takahashi trans. by Hisashi Kuboyama Part IV: Hinterland and Nature Chapter 10 Flooding in Edo and the Tone-gawa River and Tama-gawa River Systems / Koichi Watanabe trans. by Hisashi Kuboyama Chapter 11 The Great Edo Flood of 1742 and the Okutama Valley / Koichi Watanabe trans. by Hisashi Kuboyama Chapter 12 The Deluge of Istanbul in 1563: a Case of Flood Where There Was No River / Kazuaki Sawai trans. by Yoko Onodera Chapter 13 Storms, Flooding and the Development of London 1300-1500 / Matthew Davies Chapter 14 Bridging London’s River’s General Situation of London, the Thames, the Bridge / Vanessa Hardin
Long-term changes in summer temperature anomaly patterns in Japan since the early 20th century
Climatological characteristics of monsoon seasonal transitions over Bangladesh
Climatological characteristics of monsoon seasonal transitions in Bangladesh, focusing on onset and withdrawal phases, were examined using pentad and 20-day mean wind, moisture flux, and precipitable water distributions obtained from Japanese 25-year re-analysis data from 1979 to 2003 and rainfall data from the Bangladesh Meteorological Department (BMD) from 1948 to 2008. Analysis of the pentad and 20-day mean horizontal wind at 850 hPa, the total column water vapor flux, and the precipitable water distribution around Bangladesh showed that the onset and withdrawal of the summer monsoon season in Bangladesh occurred between pentad 31 (May 31-June 4) and pentad 32 (June 5-9), and between pentad 56 (October 3-7) and pentad 57 (October 8-12), respectively. Changes in wind at 850 hPa, total column water vapor flux, precipitable water, and rainfall distribution associated with monsoon onset and withdrawal phases are described by consecutive 20-day mean maps. The annual cycle of 5-day mean rainfall is also presented for each BMD station. High rainfall occurred in the northeast region (Sylhet) during the pre-monsoon season and in the southeast region (Teknaf) during the monsoon season. The central west region (Ishurdi) received relatively less rainfall in all seasons. In the post-monsoon season, rainfall amounts did not differ much among the stations