Enhancement and suppression of ice formation around isothermally cooled cylinders in convective water flow

To enhance and suppress ice formation around isothermally cooled cylinders in convective water flow, circular fins and heat conductor plates are used, respectively. The heat conductor plates are positioned around each cylinder with some clearance. In the present experiment, the cooled cylinders had a staggered alignment. The experimental results show that the present analytical method for cooled cylinders with fins and heat conductor plates is useful for predicting ice volume under the conditons in which the cooled cylinders are not completely linked by ice in a steady-state condition. It is found that ice accumulation with fins is significantly enhanced compared to that without fins. It is also shown that use of cylinders with the heat conductor plates is effective for suppression of ice formation. © 1998 Scripta Technica, Heat Trans Jpn Res, 26(7): 419–434, 1997     

Characterization of BAMO/NMMO Copolymers

The compositions and microstructures, thermolyses, and sensitivities of 3,3-bis(azidomethyl)oxetane (BAMO) copolymers with 3-nitratomethyl-3-methyloxetane (NMMO) were characterized. The molar ratios of monomers fed in the copolymerizations were: BAMO/NMMO = 8/2, 7/3, and 6/4. The observed compositions were 81/19, 68/32, and 60/40, respectively. The relative compositions of trade microstructures were also exactly the same as theoretical values. The copolymerization of BAMO with NMMO behaved like an ideal system in the sense that the copolymer has approximately the same composition as the monomer fed. The microstructures of copolymers were also randomly arranged. Poly BAMO showed side chain decomposition in the initial stage of the thermolysis, on the other hand, backbone decomposition controlled the thermolysis of poly NMMO. The BAMO units and the NMMO units appeared to decompose more or less independently of one another and retained their individual decomposition characteristics despite being copolymerized. However, the heat generated by the NMMO decomposition, which occurred at 40°C lower than that of BAMO. activated the reaction of BAMO. Poly B/N(7/3) showed very interesting characteristics in sensitivities, mechanical properties, and the heat of decomposition.     

Visualization analysis of reciprocating‐screw plastication process of glass fiber‐reinforced resins in a glass‐inserted heating cylinder

One challenge in injection molding of long fiber‐reinforced resins is minimizing the fiber breakage during resin plastication and resin flow into a mold. Such fiber breakage reduces the strength of the molded product. Reciprocating plastication is subjected to periodic positional fluctuations of the screw and cylinder in the molding cycle. In this study, visualization experiments were conducted on the reciprocating plastication of long glass fiber (GF)‐reinforced polypropylene with 50 wt% GF. It was found that: (1) temporary voids form in the resin during the metering process, and the pellets rotate from an orthogonal to parallel orientation in the flight direction; (2) length of the weight‐averaged fiber temporarily decreased in the middle stage of the injection process; (3) length of the weight‐averaged fiber was most strongly influenced by the waiting time; and (4) for constant waiting time, the fiber breakage could be minimized by lowering the rotation speed, lowering the back pressure, and shortening the charge stroke. POLYM. ENG. SCI., 59:846–853, 2019. © 2018 Society of Plastics Engineers     

Effect of Angiotensin II on Chondrocyte Degeneration and Protection via Differential Usage of Angiotensin II Receptors

The renin–angiotensin system (RAS) controls not only systemic functions, such as blood pressure, but also local tissue-specific events. Previous studies have shown that angiotensin II receptor type 1 (AT₁R) and type 2 (AT₂R), two RAS components, are expressed in chondrocytes. However, the angiotensin II (ANG II) effects exerted through these receptors on chondrocyte metabolism are not fully understood. In this study, we investigated the effects of ANG II and AT₁R blockade on chondrocyte proliferation and differentiation. Firstly, we observed that ANG II significantly suppressed cell proliferation and glycosaminoglycan content in rat chondrocytic RCS cells. Additionally, ANG II decreased CCN2, which is an anabolic factor for chondrocytes, via increased MMP9. In Agtr1a-deficient RCS cells generated by the CRISPR-Cas9 system, Ccn2 and Aggrecan (Acan) expression increased. Losartan, an AT₁R antagonist, blocked the ANG II-induced decrease in CCN2 production and Acan expression in RCS cells. These findings suggest that AT₁R blockade reduces ANG II-induced chondrocyte degeneration. Interestingly, AT₁R-positive cells, which were localized on the surface of the articular cartilage of 7-month-old mice expanded throughout the articular cartilage with aging. These findings suggest that ANG II regulates age-related cartilage degeneration through the ANG II–AT₁R axis.     

Deposition of mechanically hard amorphous carbon nitride films with high [N] / ([N] + [C]) ratio

Mechanically hard amorphous carbon nitride films were prepared by a combination of negative radio frequency (RF) bias voltage (− V_RF) applied to a substrate and chemical vapor deposition using a decomposition reaction of BrCN with a microwave discharge flow of Ar. A pulsed operation of − V_RF was effective when − V_RF > 40 V to avoid excess sputtering of films. The [N] / ([N] + [C]) ratios of films were ≈ 0.5 irrespective of the application of − V_RF. The maximum hardness was 36 ± 10 GPa for the film obtained under the conditions of − V_RF = 100 V, a pulse period of 1000 s, and a pulse-on time of 800 s. According to the IR spectra, the intensity of the stretching vibration of the CN bond increased by the application of − V_RF. The Raman spectra showed increases in the relative intensity and width of the D-band. From these observations, the mechanism of film hardening was discussed.     

Simple synthesis of diastereomerically pure phosphatidylglycerols by phospholipase D-catalyzed transphosphatidylation

A simple method for synthesizing diastereomerically pure phosphatidylglycerols (PtdGro), namely, 1,2-diacyl-sn-glycero-3-phospho-3′-sn-glycerol (R,R configuration) and 1,2-diacyl-sn-glycero-3-phospho-1′-sn-glycerol (R,S configuration) was established. For this purpose, diastereomeric 1,2-O-isopropylidene PtdGro were prepared from 1,2-diacyl-sn-glycero-3-phosphocholine (PtdCho) and enantiomeric 1,2-O-isopropylideneglycerols by transphosphatidylation with phospholipase D (PLD) from Actinomadura sp. This species was selected because of its higher transphosphatidylation activity and lower phosphatidic acid (PtdOH) formation than PLD from some Streptomyces species tested. The reaction proceeded well, giving almost no hydrolysis of PtdCho to PtdOH in a biphasic system consisting of diethyl ether and acetate buffer at 30°C. The isopropylidene protective group was removed by heating the diastereomeric isopropylidene PtdGro at 100°C in trimethyl borate in the presence of boric acid to obtain the desired PtdGro diastereomers. The purities of the products, which were determined by chiral-phase HPLC, were exclusively dependent on the optical purities of the original isopropylideneglycerols used. The present method is simple and can be utilized for the synthesis of pure PtdGro diastereomers having saturated and unsaturated acyl chains.     

Prediction of the behaviors of H2S and HCl during gasification of selected residual biomass fuels by equilibrium calculation

H₂S and HCl released during biomass gasification can decrease the performance of high-temperature fuel cells in an Integrated Biomass Gasification Fuel Cell power-generating system. In this study, the behaviors of such poisonous gases during the gasification of different biomass fuels at various temperatures ranging from 673 to 1473 K were predicted using an equilibrium calculation approach. The predictions showed not only a difference in emission behaviors of HCl and H₂S among the biomass fuels, but also a low HCl emission (below 10 ppmv) for a few of the fuels at any temperature. In addition, the influence of biomass metal composition and gasification temperature on emission behavior was investigated by analyzing the distribution of chlorine and sulfur compounds and the phase diagram of selected elements such as silicon and aluminum. Finally, we suggest that the addition of a potassium-rich biomass to a potassium-poor biomass has the potential to reduce the HCl emission during gasification and then to maintain the HCl concentration in gas phase below the tolerance concentration of the fuel cells.     

Visual analysis of plastication of long‐glass fiber‐reinforced resins using a glass‐insert heating cylinder

The fiber‐reinforced plastication processes during the injection molding of reinforced resins with long fibers are difficult to observe through visualization cylinders because of possible obstacles, such as (1) opacification of melts, (2) abrasion on the inner surface of glass windows, and (3) breakage of glass windows under high pressures. In this study, we visualized the plastication process of long‐glass fiber‐reinforced resins containing 50 wt% fibers. In plastication experiments using three full‐flight screws with different compression ratios, we observed the instability of the melting process, the generation of solid beds and melt pools, and the breakup of melted segments. We demonstrated that the plastication process depends considerably on the compression ratio and clarified the characteristic molding phenomena related to fiber breakup. Based on our observations, we proposed a model that explains the different fiber breakage distributions at different compression ratios during the melting process of long‐glass fiber‐reinforced resins. POLYM. ENG. SCI., 59:1300–1309 2019. © 2019 Society of Plastics Engineers     

Growth process and short chain alcohol separation performance of fluoride-containing NaY zeolite membrane

Growth process of the NaY zeolite membranes was investigated by fluoride-containing precursor synthesis gel.Compared with the fluoride-free precursor synthesis gel,the irregular NaY zeolite crystals were dissolved into amorphous by the fluoride-containing precursor synthesis gel initially,the amorphous contained the Y-type zeolite characteristic bands by the IR characterization.The fine square NaY zeolite crystals arose from the amorphous,which were accumulated and gradually grew into a dense NaY zeolite layer on the support surface after 6.5 h.Because the excessive NaY zeolites were dissolved by the strong alkaline and fluoride-containing precursor synthesis gel,there was plenty of amorphous on NaY zeolites layer for prolonging the crystallization time.The assynthesized NaY zeolite membranes had a good separation performance and repeatability for separation of 10 wt%methanol(MeOH)/methyl methacrylate(MMA) mixture by pervaporation,the flux and separation factor were(1.27 ± 0.07) kg·M~(-2)·h~(-1) and(4900 ± 1500) at 323 K,respectively.Besides,the NaY zeolite membranes were applied to separate the other short chain alcohol from the various alcohol/organic ester and alcohol/organic ether mixtures,the NaY zeolite membranes showed high short chain alcohol perm-selectivity.     

Deep Association between Transglutaminase 1 and Tissue Eosinophil Infiltration Leading to Nasal Polyp Formation and/or Maintenance with Fibrin Polymerization in Chronic Rhinosinusitis with Nasal Polyps

Transglutaminase (TGM) isoform catalyze the cross-linking reaction of identical or different substrate proteins. Eosinophil has been recognized in chronic rhinosinusitis with nasal polyps (CRSwNP) forming tissue eosinophil in nasal polyp (NP), and TGM isoforms are suggested to be associated with a critical role in asthma and other allergic conditions. The aim of this study was to reveal the association of specific TGM isoform with both the tissue eosinophil infiltration deeply concerning with the intractable severity of CRSwNP and the fibrin polymerization ability of TGM isoform associated with the tissue eosinophil infiltration, which lead to NP formation and/or maintenance in CRSwNP. NP tissues (CRSwNP group) and uncinate process (UP) (control group) were collected from patients with CRSwNP and control subjects. We examined: (1) the expression level of TGM isoforms by using a real-time polymerase chain reaction (PCR) and the comparison to the issue eosinophil count in the CRSwNP group, (2) the location of specific TGM isoform in the mucosal tissue using immunohistochemistry, (3) the inflammatory cell showing the colocalization of specific TGM isoform in Laser Scanning Confocal Microscopy (LSCM) imaging, and (4) the fibrin polymerase activity of specific TGM isoform using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). A certain level of TGM 1, 2, 3, 5 expression was present in both the CRSwNP group and the control group. Only TGM 1 expression showed a positive significant correlation with the tissue eosinophil count in the CRSwNP group. The localization of TGM 1 in NP (CRSwNP) laid mainly in a submucosal layer as inflammatory cells and was at the cytoplasm in the tissue eosinophil. Fibrin polymerase activity of TGM 1 showed the same polymerase ability of factor XIIIA. TGM 1 might influence the NP formation and/or maintenance in CRSwNP related to the tissue eosinophil infiltration, which formed fibrin mesh composing NP stroma.