An experimental study on the evaporation of freely falling droplet under high temperature and high pressure gas stream

An experimental apparatuses and measuring system have been made to obtain characteristics connected with evaporation, ignition delay, combustion of a freely falling liquid fuel droplet in high temperature and high pressure gas stream. In this study some systematic experiments were performed to test the utility of the system. The newly devised apparatus was ensured reliability and utility from the tentative experimental results.     

Optimal energy efficiency routing strategy based on community in mobile social network

An optimal energy efficiency routing strategy based on community was proposed,which minimized the network energy consumption under the given delay constraint.Firstly the expected energy consumption and delay of message delivery in the connected network were obtained through Markov chain.Then the comprehensive cost function for delivering message from source node to destination node was designed,which was combined with energy consumption and delay.Thus,the optimization function to comprehensive cost of relay node delivering message was obtained,and further the reward function of relay node was gotten.Finally the optimal expected reward of optimal relay node was achieved using the optimal stopping theory,so as to realize the optimal energy efficiency routing strategy.In simulations,the average energy consumption,the average delay and the average delivery ratio of routing optimization strategy were compared with those of other routing strategies in related literatures.The results show that the strategy proposed has smaller average energy consumption,shorter average delay and higher average delivery ratio,gaining better energy consumption optimization effect.     

Effect of probe arrangement on reproducibility of images by near-infrared topography evaluated by a virtual head phantom

The effect of the probe arrangement on the reproducibility of topographic images of the concentration changes in oxygenated hemoglobin and deoxygenated hemoglobin is evaluated by a virtual head phantom. A virtual head phantom consists of five types of tissue the 3D structure of which is based on a magnetic resonance imaging scan of an adult head. Localized and broadened brain activation is assumed in a virtual head phantom. The topographic images are obtained from the reflectance detected by the standard probe arrangement and the double-density probe arrangement. The uneven thickness of the superficial layer, which cannot be evaluated by the previous slab model, affects the distribution of measured activation in the topographic image, and this reduces the position reproducibility of near-infrared (NIR) topography with the standard probe arrangement. The overlapping measurements by the double-density probe arrangement can improve the reproducibility of the image obtained by NIR topography.     

Effects of photo-induced graft polymerization of 2-methacryloyloxyethyl phosphorylcholine on physical properties of cross-linked polyethylene in artificial hip joints

Osteolysis caused by wear particles from polyethylene in the artificial hip joints is a serious issue. We have used photo-induced radical graft polymerization to graft 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer onto the surface of cross-linked polyethylene (CLPE-g-MPC) in order to reduce friction and wear at the bearing surface of the joint. The physical and mechanical properties of CLPE and CLPE-g-MPC were not significantly different, expect that the friction coefficient of untreated CLPE cups was 0.0075, compared with 0.0009 for CLPE-g-MPC cup, an 88% reduction. After 3.0 × 10⁶ cycles in the hip joint simulator test, we could not observe any wear of CLPE-g-MPC cups. We concluded that the advantage of photo-induced radical graft polymerization technique was that the grafted MPC polymer gave a high lubricity only on the surface and has no effect on the bulk properties of the CLPE substrate.     

Association of mineral metabolism factors with all-cause and cardiovascular mortality in hemodialysis patients: the Japan dialysis outcomes and practice patterns study

Abnormalities in mineral metabolism have been linked to mortality in hemodialysis (HD) patients. We postulated that these abnormalities would have a particularly large deleterious impact on deaths due to cardiovascular causes in Japan. This study describes the recent status of abnormal mineral metabolism, significant predictors, and potential consequences in the Dialysis Outcomes and Practice Patterns Study (DOPPS), Phases 1 and 2, in Japan. Major predictor variables were patient demographics, comorbidities, and laboratory markers of mineral metabolism such as albumin-adjusted serum calcium (calciumAlb), phosphorus, and intact PTH (iPTH). In a cross section of 3973 Japanese HD patients in DOPPS I and II, a large faction had laboratory values outside of the recommended Kidney Disease Outcomes Quality Initiative (K/DOQI) guideline range for serum concentrations of phosphorus (51% of patients above upper target range), calciumAlb (43.7% above), calcium-phosphorus (Ca x P) product (41.1% above), and iPTH (18.6% above). All-cause mortality was significantly and independently associated with calciumAlb (relative risk [RR]=1.22 per 1 mg/dL, p=0.0005) and iPTH (RR=1.04 per 100 pg/mL, p=0.04). Cardiovascular mortality was significantly associated with calciumAlb (RR=1.28, p=0.02), phosphorus (RR=1.13 per 1 mg/dL, p=0.008), Ca x P product (RR=1.07 per 2 mg(2)/dL(2), p=0.002), and PTH (RR=1.08, p=0.0001). This study expands our understanding of the relationship between altered mineral metabolism and mortality outcomes, showing slightly stronger associations with cardiovascular causes than observed for all-cause mortality. These findings have important therapeutic implications for Japanese HD patients.     

The effects of prostaglandin E1 on intraoperative temperature changes and the incidence of postoperative shivering during deliberate mild hypothermia for neurosurgical procedures

We investigated the effects of i.v. prostaglandin E1 (PGE1) on intraoperative changes of core temperature and the incidence of postoperative shivering in neurosurgical patients undergoing deliberate mild hypothermia. Eighty-three patients were randomly assigned to one of three groups: patients in the control group did not receive PGE1, whereas patients in the PG20 group and PG50 group received PGE1 at a dose of 0.02 and 0.05 microg x kg(-1) x min(-1), respectively. The administration of PGE1 was started just after the induction of anesthesia and continued until the end of anesthesia. Anesthesia was maintained with nitrous oxide in oxygen, sevoflurane, and fentanyl. After the induction of anesthesia, patients were cooled using a water blanket and a convective device blanket. Tympanic membrane temperature was maintained at 34.5 degrees C. During surgical wound closure, patients were rewarmed. Intraoperative changes in tympanic membrane and skin temperatures and the incidence of postoperative shivering were compared among groups. Demographic and intraoperative variables were similar among groups. There were no significant differences in tympanic temperatures among groups at each point during the operation. Skin temperature 30 min after rewarming and just after tracheal extubation was significantly lower in the PG20 group than in the PG50 group. Postoperative shivering was more frequent in the PG20 group (43%) than in the control (13%) and PG50 (17%) groups. These results suggest that the intraoperative administration of PGE1 does not affect changes in core temperature during deliberate mild hypothermia and that PGE1 at a dose of 0.02 microg x kg(-1) x min(-1) may increase the occurrence of postoperative shivering. Implications: Deliberate mild hypothermia has been proposed as a means of providing cerebral protection during neurosurgical procedures. Vasodilating drugs may be used during deliberate mild hypothermia to maintain peripheral circulation and to enhance the cooling and rewarming rate. In the present study, however, we found no benefit from i.v. prostaglandin E1 administration during deliberate mild hypothermia in neurosurgical patients.     

Effects of spacer-chain length on the photoelectrochemical responses of monolayer assemblies with ruthenium tris(2,2′-bipyridine) - viologen linked disulfides

Photochemical and photoelectrochemical properties of ruthenium tris(2,2′-bipyridine) (Ru²⁺)-viologen (V²⁺) linked disulfides [RuCnVC₆S]₂ (n (number of methylene groups)=3, 7) with different spacer-chain lengths and Ru²⁺ disulfides [RuC_mS]₂ (m=13, 17) were compared. The luminescence intensity in CH₃CN was in the order of [RuC₁₃S]₂≈[RuC₁₇S]₂>[RuC₇VC₆S]₂[RuC₃VC₆S]₂, implying efficient photoinduced electron-transfer between Ru²⁺ and V²⁺ moieties in the linked compounds. The monolayer assembly of the compound was fabricated on a gold surface. In the presence of triethanolamine, the anodic photocurrent was clearly observed from the RuC_nVC₆S/Au (n=3, 7) electrode (gold electrode modified with [RuCnVC₆S]₂), and its intensity was substantially larger for n=7 than for n=3. Photocurrent action spectra for the RuC_nVC₆S/Au (n=3, 7) electrodes were well correlated with the corresponding electronic absorption spectra in solution. The photocurrent from the RuC₇VC₆S/Au electrode was reduced more effectively by the coexistence of a water-soluble viologen as compared with the RuC₃VC₆S/Au electrode. The photocurrent from the RuC_mS/Au (m=13, 17) electrode was very small. The results suggest that the spacer-chain length between the Ru²⁺ and the V²⁺ moieties profoundly affects the Ru²⁺-sensitized photocurrent.     

松油烯与马来酸酐的Diels-Alder反应的研究

研究了松油烯与马来酸酐的分子间Diels-Alder环加成反应和松油烯的异构转化行为。使用相对于α-松油烯过量的马来酸酐,相对于α-松油烯而言,在65～70℃二时有大约15％,在100～105℃下有38％,在135～140℃时有69％的松油烯异构转化率。同样在65～70℃和100～105℃温度下,矾土、活性白土、硅胶、离子交换树脂、对甲基苯磺酸催化下,大约有20％～77％的异构转化率。用异核远距离关联(HMBC)等核磁共振测试手法解析了环加成产物的结构,归属了各原子的化学位移。     

Curing of epoxy resin by ultrafine silica modified by grafting of hyperbranched polyamidoamine using dendrimer synthesis methodology

Hyperbranched polyamidoamine–grafted silica was prepared according to dendrimer synthesis methodology. The modified silica was dispersed uniformly in epoxy resin, and the curing of epoxy resin proceeded successfully by heating in the presence of the modified silica; the gel fraction of the epoxy resin cured by the hyperbranched polyamidoamine–grafted silica (grafting = 80.2%) reached 77% at 170°C after 48 h. The gel fraction increased with increasing terminal amino group content of the hyperbranched polyamidoamine–grafted silica. In addition, the curing ability of the silica increased by complexation of the terminal amino groups of the grafted polyamidoamine with boron trifluoride. The modulus of elasticity of the curing materials obtained using the modified silica as a curing agent was lower than that using conventional a curing agent such as ethylenediamine in the presence of untreated silica. On the other hand, the heat resistance of the curing product using the modified silica was superior to that using ethylenediamine, but no difference in glass‐transition temperature was observed. It is expected that hyperbranched polyamidoamine grafted‐silica is incorporated uniformly with chemical bonds in the matrix of the epoxy resin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 573–579, 2001     

Compact thermosyphon using multistacked radiator cores for automobiles: Refrigerant circulation and cooling performance

A new closed two‐phase loop thermosyphon with multi‐stacked radiator cores and a new flow controller forming a refrigerant circulation have been developed. When the temperature of the partition wall which separates the liquid return passage from boiling the region of the refrigerant tank becomes extremely high, the refrigerant circulation is inhibited. The inhibition factor of the refrigerant circulation was clarified. © 2000 Scripta Technica, Heat Trans Asian Res, 29(3): 204–217, 2000