The present invention relates to a polyimide precursor comprising a repeating unit represented by the following chemical formula (1): ##STR00001##
wherein A is a tetravalent group having at least one aliphatic six membered ring and no aromatic ring in the chemical structure, and B is a divalent group having at least one amide bond and an aromatic ring in the chemical structure; or A is an aliphatic tetravalent group and B is a divalent group having at least one chemical structure represented by the following chemical formula (2) in the chemical structure: ##STR00002##
and X.sub.1 and X.sub.2 are each independently hydrogen, a C.sub.1-6 alkyl group or a C.sub.3-9 alkylsilyl group.

The present invention relates to a polyimide precursor comprising a repeating unit represented by the following chemical formula (1): ##STR00001##
wherein A is a tetravalent group having at least one aliphatic six membered ring and no aromatic ring in the chemical structure, and B is a divalent group having at least one amide bond and an aromatic ring in the chemical structure; or A is an aliphatic tetravalent group and B is a divalent group having at least one chemical structure represented by the following chemical formula (2) in the chemical structure: ##STR00002##
and X.sub.1 and X.sub.2 are each independently hydrogen, a C.sub.1-6 alkyl group or a C.sub.3-9 alkylsilyl group.

This invention relates to a stand for supporting hay bales above the ground. The inventive hay stand The device is formed in the shape of an rectangular prism or cuboid from an inert plastic, closed-cell, polyurethane structural foam that will not allow water or air to move through it. The devices are constructed by pouring the structural foam material into forms that are constructed to yield the desired shape. The structural foam has two chemicals that are mixed and then poured into the form. The foam then heats and rises to take on the shape of the interior of the form. Once the foam is fully cured, the forms are removed, and the device is ready for use. Hay stands constructed in accordance with the present invention are useful for protecting hay bales from spoilage due to ground moisture.

The present invention relates to a vane member for a paper sheet conveyance impeller, which includes a rotatable cylindrical member, the vane member being provided with: a vane member body comprising a thermosetting polyurethane elastomer; and a plurality of core wires which comprise polyester fibers and are arranged along the axial direction of a rotary shaft of the cylindrical member. At least a portion of the core wires is embedded within the vane member body. The vane member may be disposed so as to protrude from the external peripheral surface of the rotatable cylindrical member.

Presented are manufacturing systems, methods, and devices for forming footwear using scrap or waste plastic materials. A method for manufacturing an article of footwear, such as an athletic shoe, begins with receiving a batch of recycled plastic, which may include thermoplastic elastomers or ethylene-vinyl acetate, and grinding the batch of recycled plastic material. The ground recycled material is processed, for example, by adding a foaming agent that activates at elevated temperatures. The processed recycled material is placed into the internal cavity of a final mold that is shaped like a segment of the footwear, such as a unitary sole structure. To form the footwear segment, the processed recycled material is heated past the threshold activation temperature of the foaming agent such that the foaming agent causes the recycled material to expand and fill the internal cavity of the final mold. The formed footwear segment is then extracted from the mold.

An attachment for an end effector. The attachment may include a clamp and a foot adhesively bonded to an edge of the clamp and having a set of interlocking features that form a mechanical interlock with the clamp.

The invention relates to a reversible microfluidic chip comprising at least one lower part and at least one upper part configured to come into contact with said lower part and to close said chip, said lower part and/or said upper part comprising a microfluidic structure, and said upper part comprising at least one layer of a flexible epoxide polymer material and at least one layer of a rigid epoxide polymer material, at least one part of the flexible layer being directly in physical contact with the lower part of the chip when said chip is in the closed configuration, to the method for the fabrication thereof, to the use of said upper part in a reversible microfluidic chip, to said upper part for producing said chip, and to the uses of said chip in various applications.

A dried vitrigel membrane is produced by a method including the following steps of (1) a step of keeping a hydrogel in the inside of a wall surface mold with a shape the same as the desired shape disposed on a substrate, and discharging a part of free water within the hydrogel from a gap between the substrate and the wall surface mold; (2) a step of removing the wall surface mold from the top of the substrate; (3) a step of drying the hydrogel to remove the residual free water, thereby fabricating a vitrified dried hydrogel; (4) a step of rehydrating the dried hydrogel to fabricate a vitrigel membrane; and (5) a step of redrying the vitrigel membrane to remove free water, thereby fabricating a vitrified dried vitrigel membrane.

A dried vitrigel membrane is produced by a method including the following steps of (1) a step of keeping a hydrogel in the inside of a wall surface mold with a shape the same as the desired shape disposed on a substrate, and discharging a part of free water within the hydrogel from a gap between the substrate and the wall surface mold; (2) a step of removing the wall surface mold from the top of the substrate; (3) a step of drying the hydrogel to remove the residual free water, thereby fabricating a vitrified dried hydrogel; (4) a step of rehydrating the dried hydrogel to fabricate a vitrigel membrane; and (5) a step of redrying the vitrigel membrane to remove free water, thereby fabricating a vitrified dried vitrigel membrane.

Provided are a mold case that prevents deformation of a microneedle array, and a manufacturing method of a microneedle array. The problems are solved by the manufacturing method of a microneedle array including: a filling step of filling needle-like recessed portions of a mold having flexibility and having a plurality of the needle-like recessed portions on a front surface, with a liquid material; and a drying step of drying the liquid material in a state where the mold filled with the liquid material is stored in the mold case which causes an edge portion of the mold to be sandwiched between the lid and the pedestal.