Other

Daicel Chemical Industries, Ltd.

Alcoa Inc.

Ministry of International Trade & Industry

Japan Represented by Ministry of International Trade and Industry,

Yasushi Maeda

Shawn J Murtha

Hitoshi Tsugaya

Masahiro Yanagawa

Daniel J Lege

Shigeo Hattori

Narikazu Hashimoto

John C Brem

Frederic Barlat

Kuniaki Matsui

Kwansoo Chung

Kengo Magara

Yasuhiro Hayashida

Michio Tsuyumoto

Shinji Makikawa

Seiki Ejima

Masaharu Horiguchi

Hiroki Karakane

Masahiko Sugimoto

Yasuhiro Havashida

A silicon substrate is prepared by furnishing a silicon substrate ( ) having a step ( ) of at least 5 &mgr;m high on one surface, forming by high pressure heat oxidation an oxide film ( ) which is thinner than the step, and removing the oxide film on the higher surface region until the silicon surface is exposed in the higher surface region while leaving the oxide film on the lower surface region. Because of excellent electrical properties, minimized warpage, a substantially constant oxygen concentration, and a definitely ascertainable oxide-silicon boundary, the silicon substrate is suitable for use in optical waveguide devices.

Preparation of silicon substrate

An Al&mdash;Mg based alloy sheet product in which the crystallographic texture exhibits a ratio of the volume fraction of grains in the S orientation &lcub;123&rcub;<634> to the volume fraction of grains in the CUBE orientation &lcub;100&rcub;<001> (S/Cube) being 1 or more, and is comprised of grains with a volume fraction of about 10% or less in the GOSS orientation &lcub;110&rcub;<001>, wherein the grain size is in a range of about 20 to 100 &mgr;m demonstrates good formability.

A1-mg based alloy sheets with good press formability

Al-Mg based alloy sheets with good press formability

By careful control of composition and processing, Al--Mg based alloy sheets with preferred grain sizes and crystallographic textures that result in good press formability are disclosed. The Al--Mg alloy preferably contains 2-6 wt % Mg, and at least 0.03 wt % of at least one element selected from Fe, Mn, Cr, Zr, and Cu. The crystallographic texture is comprised of grains with a volume fraction in a range of about 5% to 20% in the CUBE orientation {100} &lt;001&gt;, a volume fraction in a range of about 1% to 5% in the GOSS orientation {110} &lt;001&gt;, a volume fraction in a range of about 1% to 10% in each of the BRASS orientation {110} &lt;112&gt;, S orientation {123} &lt;634&gt;, and COPPER orientation {112} &lt;111&gt;, wherein the grain size is in a range of about 20 to 70 .mu.m.

Al--Mg based alloy sheets with good press formability

A separatory membrane is provided which has a sufficient durability and shows a high rate of permeation therethrough and a high separation factor to a variety of organic substances and a wide range of concentration thereof in mutual separation of organic substances and separation of a water/organic substance mixture by pervaporation, vapor permeation or perstraction. The separatory membrane shows the performance that water permeates selectively through the membrane while satisfying such conditions that the product (QL) of the rate Q (kg/m.sup.2 .multidot.hr) of permeation and the thickness L (.mu.m) of the membrane is at least 0.5 kg.multidot..mu.m/m.sup.2 .multidot.hr and that the separation factor .alpha..gtoreq.10 and log.alpha..gtoreq.-1.77.times.log(QL)+2.77 when the pervaporation performance of a 5-30 .mu.m-thick dense uniform membrane is evaluated using as a liquid feed, an 80 wt. % aqueous solution of acetic acid at a temperature of 70.degree. C., and comprises, as the membrane material, a polyacrylonitrile copolymer constituted of 90 to 97 mol % of acrylonitrile monomer units and a specific comonomer(s).

Permselective membrane of polyacrylonitrile copolymer and process for

Separating membrane of polyion complex

Polyparabanic acid membrane for selective separation

Hydrolyzed membrane and process for the preparation of the same

Growing community of inventors

Hyogo, Japan

Yasushi Maeda