Study on Turbulent Boundary Layer with Injection and Combustion

Results are presented of the calculation of the velocity field and of the experiments of mean profile measurements in the turbulent boundary layer with injection and combustion. The agreement between the present calculation, which is the extension of the Economos' method, and the experimental results of other investigators is not very good. Thus, the cause of this disagreement is discussed by making use of the results of the present measurements. Through further examination of the same experimental results, some characteristics of the flow are clarified, and the important points to be considered during future study are pointed out

Novel anti-decay self-setting paste of hydroxyapatite/collagen nanocomposite utilizing GPTMS

Bone is a typical inorganic/ortganic nanocomposite mainly composed of hydroxyapatite (HAp) nanocrystals and collagen molecules. The composition and nanostructure is closely related to bone’s biomechanical and biochemical properties. One of the most important things for bone is a bone remodeling process that maintains mechanical strength of bone to allow walking and running as well as homeostasis of calcium in our body. In fact, sintered HAp composed of HAp crystals approximately 1 µm in particle size is considered as non-bioresorbable; however HAp nanocrystals easily resorbed by osteoclasts. A hydroxyapatite/collagen bone-like nanocomposite (HAp/Col) was successfully synthesized by the authors via self-organizing process. [1] The HAp/Col is incorporated into bone remodeling process completely as the same as the autologous bone transplanted and substituted with new bone in 3 months. Porous type HAp/Col was also developed by the authors and shows spoge-like viscoelastity in wet condition. [2] The porous HAp/Col had been tested clinically and has been being sold in Japan from April, 2013 as ReFit®. According to the clinical test [3], the HAp/Col shows higher rate of remarkable efficiency in comparison to Osferion®, porous β-tricalcium phosphate, for substitution with newly formed bone. In addition, sponge-like deformability allows to fit irregular shape of bone defects as well as to press to pack the porous HAp/Col in cavity created by removal of benign bone tumor. On the other hand, recent need from surgeon for bone filler is a self-setting bone paste with bioresorbability. Previously, the HAp/Col anti-decay self-setting paste was prepared successfully with the use of sodium alginate and calcium compounds. It showed tolerant paste properties; however, the paste contained 30 % in mass of calcium compounds that could interfered excellent biological activity of the HAp/Col. In this study, the HAp/Col paste with injectability, self-setting and anti-decay abilities was prepared using the HAp/Col powder and 1 % in volume of 3-glycidoxypropyl)methyldiethoxysilane (GPTMS) aqueous solution. The paste obtained was evaluated by viscosity, hardening behavior and anti-decay property tests. The HAp/Col was synthesized according to ref 1. The HAp/Col was compacted with specially designed mold by uniaxially press squeezing of water from the HAp/Col. The HAp/Col compact was then crushed and ball-milled to obtain the HAp/Col particles of 100 µm or less in size. The GPTMS was dissolved in pure water at 1 % in volume and steadily placed in 25 °C for 1 h to allow hydrolysis of the GPTMS to form silanol groups. The HAp/Col powder (powder phase, P) and the GPTMS aqueous solution (liquid phase, L) were mixed at 0.20-2.00 of P/L ratio in g/cm3 to obtain a HAp/Col paste. A viscosity of the HAp/Col paste obtained was measured according to ref 1. Briefly, the paste obtained was shaped to cylinder at 5 mm in diameter and 5.1 mm in hight and start pressing at 10 min after mixing by 2 kg weight for 10 min. A spread area of the paste was measured from digital photo with Image-J. Hardening behavior was measured using the viscosity test as a function of time, because softness of the paste did not allow to apply conventional the needle method. Anti-decay property was tested according to JIS T 0330-4:2012 [5]; briefly, the paste shaped in cylinder 4.8 mm in diameter and 16.5 mm in height was placed on wire mesh and, at 5 min after mixing, soaked in phosphate buffered saline for 72 h. Debris were then collected and measured their mass, and decay ratio was calculated as debris/original masses. The paste with P/L ratio of 0.2 could not shaped by its high fluidity and that of 2.0 could not shaped because of its aggregation. The paste with P/L ratio of 0.33 could injected through 18G needle and others could injected through syringe with 1.8 mm in inner diameter. The viscosity of the paste increased with increasing in P/L ratio and did not depend on the amounts of GPTMS. The initial hardening was observed first 30-40 min from mixing and gradually hardened. The paste with P/L ratio of 1.5 showed mechanical strength more than 1 MPa with viscoelastic property. No significant decay was observed for all pastes. The HAp/Col-GPTMS paste can be good candidate for high performance injectable bone filler as well as a raw material for 3D printing

Oxygen reduction on bimodal nanoporous palladium-copper catalyst synthesized using sacrificial nanoporous copper

Nanoporous copper (NP-Cu), as a sacrificial support, was used for the synthesis of bimodal nanoporous palladium–copper (BNP-PdCu) for oxygen reduction reaction (ORR) electrodes in fuel cells. The catalytic performance of BNP-PdCu in ORR per electrochemical surface area was enhanced by the dissolution and removal of supporting NP-Cu, which indicates that the intrinsic catalytic properties of palladium are improved by the proposed synthesis strategy including galvanic replacement of copper with palladium, following copper dissolution. Cu remained on Pd surfaces even after dissolution of Cu. Additionally, significant local lattice contraction was observed at the ligament surface. First-principles calculations on the adsorbing oxygen species on Pd show that both lattice contraction and alloying with copper increase the binding energies of oxygen species to the Pd surface. The high ORR activity of the present BNP-PdCu is suggested to be mainly due to the Cu-ligand effect

Development of a new treatment for preterm birth complications using amniotic fluid stem cell therapy

This paper describes the current status of studies and clinical trials on the use of mesenchymal stem cells (MSCs) and amniotic fluid stem cells (AFSCs) for complications of preterm birth (PTB), an urgent issue in the perinatal field. PTB is a serious challenge in clinical medicine that is increasing globally, and effective control of its complications is necessary for newborns’ subsequent long life. Classical treatments are inadequate, and many patients have PTB complications. A growing body of evidence provided by translational medicine and others indicates that MSCs, and among them, the readily available AFSCs, may be useful in treating PTB complications. AFSCs are the only MSCs available prenatally and are known to be highly antiinflammatory and tissue-protective and do not form tumors when transplanted. Furthermore, because they are derived from the amniotic fluid, a medical waste product, no ethical issues are involved. AFSCs are an ideal cell resource for MSC therapy in neonates. This paper targets the brain, lungs, and intestines, which are the vital organs most likely to be damaged by PTB complications. The evidence to date and future prospects with MSCs and AFSCs for these organs are described

Evaluation of Liquefaction Potential of Gravelly Soil Layer Based on Field Performance Data

In general, gravelly soil layers are considered to be less susceptible to liquefy during earthquakes than sandy soil layers. However, in 1995 Hyogoken-Nambu Earthquake, sand ejection due to liquefaction was observed in Port Island and Rokkco Island, which were man-made islands reclaimed by gravelly soils. In this paper, firstly, site investigation including sampling by freezing technique was conducted in Rokko Island where lots of ejected sand was not observed during the earthquake to know liquefaction strengths of the reclaimed deposits. Secondly, earthquake response analyses were conducted for a site in Rokko Island as well as a site in Port Island to evaluate maximum stress ratios which were generated in the reclaimed deposits during the earthquake. Finally, relationships between maximum shear stress ratios during earthquakes and penetration resistance were investigated for liquefied sites and nonliquefied sites in the man-made islands

Characteristics of Gelation by Amides Based on trans-1,2-Diaminocyclohexane: The Importance of Different Substituents

Six diamides were prepared from trans-(1R,2R)-1,2-diaminocyclohexane and the corresponding racemate and were subsequently used as gelators. Three chiral compounds and their racemates were prepared. One of the chiral compounds and its racemate contained two n-dodecanoylamino groups as the same substituents. The other two chiral compounds and their racemates contained different substituents: 10-undecenoylamino and 2-heptyl-undecanoylamino groups, and 5-hydroxypentanoylamino and 2-heptylundecanoylamino groups. Their gelation abilities were evaluated on the basis of the minimum gel concentration using eight solvents. The thermal stability and transparency of the gels were investigated by UV-vis spectroscopy using three-component mixed solvents of hexadecyl 2-ethylhexanoate, liquid paraffin, and decamethyl cyclopentasiloxane (66 combinations). The gel-to-sol phase-transition temperatures were also studied. The viscoelastic behavior of the gels was studied by rheology measurements in the strain sweep mode. Aggregates constructing three-dimensional networks were studied by transmission electron microscopy and circular dichroism spectroscopy. The molecular packing of the gels was evaluated by small angle X-ray scattering (SAXS).ArticleBULLETIN OF THE CHEMICAL SOCIETY OF JAPAN.90(3):312-321(2017)journal articl

Biochemical evidence for the interaction of regulatory subunit of cAMP-dependent protein kinase with IDA (Inter-DFG-APE) region of catalytic subunit

AbstractTo explore the structural basis required for the holoenzyme formation of cAMP-dependent protein kinase, we have prepared rabbit anti-peptide antibodies that can block the holoenzyme formation without affecting the catalytic activity of the enzyme. The antibodies were raised against a specific site in the catalytic (C)-subunit, termed IDA (Inter-DFG-APE) region, which lies between the kinase subdomains VII and VIII. Although the C-subunit immunoprecipitated with anti-IDA antibodies could not form a stable complex with regulatory (R)-subunit, it was still susceptible to inhibition by the R-subunit or by PKI, a specific inhibitor peptide containing a pseudosubstrate site. These results indicate that there exists an IDA regionmediated interaction between the R- and C-subunits, which is distinct from that mediated through the substrate site and substrate binding site. In accordance with this idea, association of synthetic IDA peptides with the R-subunit was directly demonstrated by resonance mirror analysis. The calculated association constants of IDA peptides were high enough to suggest a possible involvement of the IDA region in the initial step of holoenzyme formation