Atomic - scale structures on hydrogen - terminated Si(100) surface

T. Hashizume 한국진공학회 2001 한국진공학회 학술발표회초록집 Vol.- No.-

Tribological properties of DLC films on polymers

T. HASHIZUME,S. MIYAKE,S. WATANABE,M. SATO 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.2002 No.10

Our study is to search for tribological properties of diamond-like carbon (DLC) films as known as anti-wear hard thin film on various polymers. This report deals with the deposition of DLC films on various polymer substrates in vacuum by magnetron radio frequency (RF) sputtering method with using argon plasma and graphite, titanium target. The properties of friction and wear are measured using a ball-on-disk wear-testing machine. The properties of friction and wear have been remarkably improved by DLC coating. Moreover the composition of DLC films has been analyzed by using auger electron spectroscopy(AES). The wear rate of titanium-containing DLC film is lower than that of no-metal-containing DLC film.

Expression of multi-copy flavonoid pathway genes coincides with anthocyanin, flavonol and flavan-3-ol accumulation of grapevine

Jeong, S.T.,Goto-Yamamoto, N.,Hashizume, K.,Esaka, M. INSTITUT FUER REBENZUECHTUNG GEILWEILERHOF DER 2008 Vitis Vol.47 No.3

An Intravenous Replenishment of Salivary Components and Dry Forage Intake in Freely Drinking Large-type Goats

Sunagawa, K.,Hashimoto, T.,Izuno, M.,Hashizume, N.,Okano, M.,Nagamine, I.,Hirata, T. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.4

Large-type goats eating dry forage secreted large volumes of saliva which resulted in the loss of $NaHCO_3$ from the blood and decreased plasma volume (hypovolemia). This research investigated whether or not the loss of $NaHCO_3$ from the blood and hypovolemia brought about by dry forage feeding actually depresses feed intake in large-type goats under free drinking conditions. The present experiment consisted of three treatments (NI, ASI, MI). All treatments in this experiment were carried out under free drinking conditions. In the NI control (NI), a solution was not infused. In the ASI treatment, i.v. infusion of artificial saliva was initiated 2 h before feeding and was continued for a total of 3 h concluding 1 h after the commencement of the feeding perod. In the MI treatment, mannitol solution was infused to replenish only water lost from the blood in the form of saliva. The hematocrit and plasma total protein concentrations during feeding in the NI control were observed to be higher than pre-feeding levels. This indicated that dry forage feeding-induced hypovolemia was caused by the accelerated secretion of saliva during the initial stages of feeding in freely drinking large-type goats. Increases in hematocrit and plasma total protein concentrations due to dry forage feeding were significantly suppressed by the ASI treatment. While hematocrit during feeding in the MI treatment was significantly lower than the NI control, plasma total protein concentrations were not different. From these results, it is clear that the MI treatment was less effective than the ASI treatment in mitigating the decreases in plasma volume brought about by dry forage feeding. This indicates that plasma volume increased during dry forage feeding in the ASI treatment which inhibited production of angiotensin II in the blood. The ASI treatment lessened the levels of suppression on dry forage feeding, but the MI treatment had no effect on it under free drinking conditions. The results indicate that despite the free drinking conditions, increases in saliva secretion during the initial stages of dry forage feeding in large-type goats caused $NaHCO_3$ to be lost from the blood into the rumen which in turn caused a decrease in circulating plasma volume and resulted in activation of the renin-angiotensin system and thus feeding was suppressed.

Seasonal analysis of the short-term effects of air pollution on daily mortality in Northeast Asia

Kim, S.E.,Honda, Y.,Hashizume, M.,Kan, H.,Lim, Y.H.,Lee, H.,Kim, C.T.,Yi, S.M.,Kim, H. Elsevier Pub.Co 2017 Science of the Total Environment Vol.576 No.-

The constituents and concentrations of pollutants, individual exposures, and biologic responses to air pollution may vary by season and meteorological conditions. However, evidence regarding seasonality of the acute effects of air pollution on mortality is limited and inconsistent. Herein, we examined seasonal patterns in the short-term associations of particulate matter (PM) smaller than 10μm (PM<SUB>10</SUB>) with daily mortality in 29 cities of three northeast Asian countries. Stratified time-series models were used to determine whether season altered the effect of PM<SUB>10</SUB> on mortality. This effect was first quantified within each season and at each location using a time-series model, after which city-specific estimates were pooled using a hierarchical Bayesian model. In all data sets, 3,675,348 non-accidental deaths were registered from 1993 to 2009. In Japan, a 10μg/m<SUP>3</SUP> increase in PM<SUB>10</SUB> was significantly associated with increases in non-accidental mortality of 0.44% (95% confidence interval [CI]: 0.03%, 0.8%) in spring and 0.42% (0.02%, 0.82%) in fall. In South Korea, a 10μg/m<SUP>3</SUP> increase in PM<SUB>10</SUB> was significantly associated with increases in non-accidental mortality of 0.51% (0.01%, 1.01%) in summer and 0.45% (0.03%, 0.87%) in fall, in cardiovascular disease mortality of 0.96% (0.29%, 1.63%) in fall, and in respiratory disease mortality of 1.57% (0.40%, 2.75%) in fall. In China, a 10μg/m<SUP>3</SUP> increase in PM<SUB>10</SUB> was associated with increases in non-accidental mortality of 0.33% (0.01%, 0.66%) in summer and 0.41% (0.09%, 0.73%) in winter, in cardiovascular disease mortality of 0.41% (0.08%, 0.74%) in spring and 0.33% (0.02%, 0.64%) in winter, and in respiratory diseases mortality of 0.78% (0.27%, 1.30%) in winter. Our analyses suggest that the acute effect of particulate air pollution could vary seasonally and geographically.

Unsteady Heat Transfer of Steam Flow with Condensation in Porous Media

S. Toda,W. S. Hsu,H. Hashizume,T. Kawaguchi 대한기계학회 1998 Heat transter conference Vol.6 No.1

A solvent-free and vacuum-free melt-processing method to fabricate organic semiconducting layers with large crystal size for organic electronic applications

Ribierre, Jean-Charles,Li, Zhao,Liu, Xiao,Lacaze, Emmanuelle,Heinrich, Benoî,t,Mé,ry, Stephane,Sleczkowski, Piotr,Xiao, Yiming,Lafolet, Fré,dé,ric,Hashizume, Daisuke,Aoyama, Tet The Royal Society of Chemistry 2019 Journal of materials chemistry. C, Materials for o Vol.7 No.11

<P>We report on an improved melt-processing method to prepare organic semiconducting layers with large crystal size and enhanced charge carrier mobilities. The organic compound used in this work is a solution-processable oligo(<I>p</I>-phenylene vinylene) derivative substituted at both ends with pyrene moieties. Accurate control of the temperature during the recrystallization of this compound from the melt enables the formation of large single crystal monodomains in thin films. The melt-processed organic layer shows higher mobilities in transistor configuration than in spin-coated films, which can be attributed to the presence of large-size crystalline monodomains as evidenced by X-ray diffraction measurements. We also investigated the photophysical properties of this material in spin-coated and melted films and found an increase of the photoluminescence quantum yield with the size of the crystals in the organic layer. The advantage of this method over the spin coating also allowed observation of amplified spontaneous emission that was only achieved in the melted film due to its improved luminescence efficiency. Overall, this study demonstrates a simple and versatile method, which does not require the use of any solvent and vacuum, to fabricate organic layers with large crystal size, suitable for the realization of organic electronic and light-emitting devices.</P>

Thin reduced graphene oxide interlayer with a conjugated block copolymer for high performance non-volatile ferroelectric polymer memory

Velusamy, D.B.,Kim, R.H.,Takaishi, K.,Muto, T.,Hashizume, D.,Lee, S.,Uchiyama, M.,Aoyama, T.,Ribierre, J.C.,Park, C. Elsevier Science 2014 Organic electronics Vol.15 No.11

Polymer ferroelectric-gate field effect transistors (Fe-FETs) employing ferroelectric polymer thin films as gate insulators are highly attractive as a next-generation non-volatile memory. For minimizing gate leakage current of a device which arises from electrically defective ferroelectric polymer layer in particular at low operation voltage, the materials design of interlayers between the ferroelectric insulator and gate electrode is essential. Here, we introduce a new solution-processed interlayer of conductive reduced graphene oxides (rGOs) modified with a conjugated block copolymer, poly(styrene-block-paraphenylene) (PS-b-PPP). A FeFET with a solution-processed p-type oligomeric semiconducting channel and ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) insulator exhibited characteristic source-drain current hysteresis arising from ferroelectric polarization switching of a PVDF-TrFE insulator. Our PS-b-PPP modified rGOs (PMrGOs) with conductive moieties embedded in insulating polymer matrix not only significantly reduced the gate leakage current but also efficiently lowered operation voltage of the device. In consequence, the device showed large memory gate voltage window and high ON/OFF source-drain current ratio with excellent data retention and read/write cycle endurance. Furthermore, our PMrGOs interlayers were successfully employed to FeFETs fabricated on mechanically flexible substrates with promising non-volatile memory performance under repetitive bending deformation.

Exciton diffusion in near-infrared absorbing solution-processed organic thin films

Shin, H.-Y.,Woo, J. H.,Gwon, M. J.,Barthelemy, M.,Vomir, M.,Muto, T.,Takaishi, K.,Uchiyama, M.,Hashizume, D.,Aoyama, T.,Kim, D.-W.,Yoon, S.,Bigot, J.-Y.,Wu, J. W.,Ribierre, J. C. The Royal Society of Chemistry 2013 Physical chemistry chemical physics Vol.15 No.8

<P>We report on singlet–singlet annihilation and exciton diffusion in as-prepared p-type and annealed n-type thin films of the low-bandgap quinoidal quaterthiophene [QQT(CN)4] using ultrafast transient absorption measurements. The decay dynamics of exciton populations are well described by a one-dimensional diffusion-limited bimolecular recombination, indicating that the singlet excitons migrate preferentially along the stacking direction. Our results show that the exciton diffusion constants in QQT(CN)4 films do not vary significantly upon thermal annealing. Exciton diffusion lengths are measured to be as high as 4 and 5 nm in as-prepared and annealed QQT(CN)4 films, respectively. We also observe an influence of the excitation densities on the singlet exciton diffusion, which is attributed to phonon scattering. Because of the possibility of patterning p–n regions in QQT(CN)4 films by thermal nanolithography techniques, this study provides important insight not only into the photophysical properties of quinoidal oligothiophene derivatives but also for their future integration into high-performance p–n nanostructured near infrared light-sensing devices.</P> <P>Graphic Abstract</P><P>Exciton–exciton annihilation and exciton diffusion processes are investigated by femtosecond transient absorption in as-prepared p-type and annealed n-type thin films of the quinoidal quaterthiophene [QQT(CN)4]. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cp43705h'> </P>