Porous Hydroxyapatite with Tailored Crystal Surface Prepared by Hydrothermal Method

2005 ◽  
Vol 284-286 ◽  
pp. 353-356 ◽  
Author(s):  
Koji Ioku ◽  
Giichiro Kawachi ◽  
Nakamichi Yamasaki ◽  
Hirotaka Fujimori ◽  
Seishi Goto
Keyword(s):  
Aspect Ratio ◽  
Vapor Pressure ◽  
Hydrothermal Method ◽  
Saturated Vapor Pressure ◽  
Crystal Surface ◽  
Saturated Vapor ◽  
Pure Water ◽  
Porous Hydroxyapatite ◽  
Exposure Method ◽  
The Mean

Porous plates of hydroxyapatite (Ca10(PO4)6(OH)2; HA) with about 0.5 to 5 mm in thickness and porous HA granules of about 40 µm to 1 mm in size with tailored crystal surface were prepared by the hydrothermal vapor exposure method at the temperatures above 105 °C under saturated vapor pressure of pure water. Porous HA plates with about 75 % porosity prepared at 120 °C were composed of rod-shaped crystals of about 20 µm in length. Porous HA granules prepared at 160 °C were also composed of rod-shaped crystals of about 20 µm in length with the mean aspect ratio of 30. These crystals were elongated along the c-axis. Rod-shaped HA crystals were locked together to make micro-pores of about 0.1 to 0.5 µm in size. Both of materials were nonstoichiometric HA with calcium deficient composition. These materials must have the advantage of adsorptive activity, because they had large specific crystal surface and much micro-pores.

Hydrothermal Preparation of Porous Hydroxyapatite with Tailored Crystal Surface

2005 ◽  
Vol 288-289 ◽  
pp. 521-524 ◽  
Author(s):  
Alin Iuga ◽  
Giichiro Kawachi ◽  
Nakamichi Yamasaki ◽  
M. Toda ◽  
Hirotaka Fujimori ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Vapor Pressure ◽  
Saturated Vapor Pressure ◽  
Crystal Surface ◽  
Saturated Vapor ◽  
Pure Water ◽  
Hydrothermal Preparation ◽  
Porous Hydroxyapatite ◽  
Exposure Method ◽  
The Mean

Porous sheets of hydroxyapatite (Ca10(PO)4(OH)2; HA) with about 50 µm to 1 mm in thickness and porous HA granules of about 50 µm to 1 mm in size with tailored crystal surface were prepared by the hydrothermal vapor exposure method at the temperatures above 105 °C under saturated vapor pressure of pure water. Porous HA sheets with about 75 % porosity prepared at 120 °C were composed of rod-shaped crystals of about 30 µm in length. Porous HA granules prepared at 160 °C were also composed of rod-shaped crystals of about 20 µm in length with the mean aspect ratio of 30. These crystals were elongated along the c-axis. Rod-shaped HA crystals were locked together to make micro-pores of about 0.1 µm in size. Both of materials were nonstoichiometric HA with calcium deficient composition. These materials must have the advantage of adsorptive activity, because they had large specific crystal surface and much micro-pores.

Porous Apatite Carrier Prepared by Hydrothermal Method

2006 ◽  
Vol 309-311 ◽  
pp. 935-938 ◽  
Author(s):  
Giichiro Kawachi ◽  
Shuji Sasaki ◽  
Kazuhiko Nakahara ◽  
Emile Hideki Ishida ◽  
Koji Ioku
Keyword(s):  
Drug Delivery ◽  
Bovine Serum Albumin ◽  
Vapor Pressure ◽  
Hydrothermal Method ◽  
Bovine Serum ◽  
High Selectivity ◽  
Basic Protein ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Graft Material

Porous apatite carrier with high selectivity of adsorption was prepared by using hydrothermal method. α-TCP as the starting material was changed into hydroxyapatite at the temperature above 120 °C for the period over 3 h under saturated vapor pressure. Porous apatite carriers were composed of rod-shaped crystals with non-stoichiometric hydroxyapatite composition. Since HA crystals had rod like shape, the area of a-surface was larger than that of c-surface. This carrier had higher selectivity for bovine serum albumin (acidic protein) than lysozyme chloride (basic protein). This material must be suitable as scaffold for cultured bone, for bone graft material and for drug delivery system (DDS).

scholarly journals Effects of nanoparticles on hydraulic cavitation

2018 ◽  
Vol 240 ◽  
pp. 03004
Author(s):  
Min-rui Chen ◽  
Jin-yuan Qian ◽  
Zan Wu ◽  
Chen Yang ◽  
Zhi-jiang Jin ◽  
...  
Keyword(s):  
Vapor Pressure ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Geometric Model ◽  
Pressure Ratio ◽  
Perforated Plate ◽  
Significant Parameter ◽  
Operation Conditions ◽  
Small Bubbles ◽  
Crucial Condition

When liquids flowing through a throttling element, such as a perforated plate, the velocity increases and the pressure decreases. If the pressure is below the saturated vapor pressure, the liquid will vaporize into small bubbles, which is called hydraulic cavitation. In fact, vaporization nucleus is another crucial condition for vaporizing. The nanoparticles contained in the nanofluids play a significant role in vaporization of liquids. In this paper, the effects of the nanoparticles on hydraulic cavitation are investigated. Firstly, a geometric model of a pipe channel equipped with a perforated plate is established. Then with different nanoparticle volume fractions and diameters, the nanofluids flowing through the channel is numerically simulated based on a validated numerical method. The operation conditions, such as the temperature and the pressure ratio of inlet to outlet, are the considered variables. As a significant parameter, cavitation numbers under different operation conditions are achieved to investigate the effects of nanoparticles on hydraulic cavitation. Meanwhile, the contours are extracted to research the distribution of bubbles for further investigation. This study is of interests for researchers working on hydraulic cavitation or nanofluids.

scholarly journals Application of a Micro-Flow Regulating Valve in Saturated Vapor Pressure Measurements

Daxue Huaxue ◽  
2021 ◽  
Vol 0 (0) ◽  
pp. 2107062-0
Author(s):  
Shuai Zhang ◽  
Jian Zhang ◽  
Shaowei Bian ◽  
Yaping Zhao ◽  
Li Shen ◽  
...  
Keyword(s):  
Vapor Pressure ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Pressure Measurements ◽  
Micro Flow ◽  
Vapor Pressure Measurements

IMPROVING THE DESIGN OF THE FILM DEODORIZER

2019 ◽  
Author(s):  
О.И. НИКОНОВ ◽  
Н.Н. БЕЛИНА ◽  
А.В. ГУКАСЯН
Keyword(s):  
Vapor Pressure ◽  
Thin Layer ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Live Steam ◽  
Deodorization Temperature ◽  
Improved Design

Приведены характеристики содержащихся в масле одорирующих веществ. Проведен анализ конструкции существующих дезодораторов. Рассчитаны параметры, влияющие на процесс дезодорации в тонком слое. Получена зависимость давления насыщенных паров от температуры дезодорации. На основе проведенных расчетов предложены способы интенсификации процесса дезодорации. Предложена усовершенствованная конструкция дезодоратора, позволяющая интенсифицировать процесс дезодорации: сократить время и уменьшить расход острого пара. The characteristics of the odorizing substances contained in the oil are given. An analysis of the design of already existing deodorizers is given. The parameters affecting the deodorization process in a thin layer are calculated. The dependence of the saturated vapor pressure on the deodorization temperature was obtained. On the basis of the calculations performed, methods for intensifying the deodorization process have been proposed. The proposed improved design of the deodorizer, which allows intensify the deodorization process: to reduce the time and reduce the consumption of live steam.

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