Abstract: A portable, retractable writing surface device provides a writing surface that may be extended from a housing and held sufficiently flat by the device to facilitate marking on the writing surface with a writing implement, such as a dry-erase marker, chalk, grease crayon, pencil, pen, permanent marker or the like. The device maintains sufficient rigidity in the extended writing surface, such that the device may be used without an additional support surface, such as a clip board or table. The writing surface may be retracted back into the housing to protect the writing surface and to reduce the size of the device for storage or transport, such as within a pocket or briefcase. Retracting the writing surface may include rolling the writing surface onto a spool, accordion folding the writing surface or otherwise reconfiguring the writing surface to make it fit into a compact space (collectively referred to herein as “compressing” the writing surface).

Abstract: This invention relates to a process for producing porous and composite materials comprising steps of: freezing a complex containing at least one calcium salt selected from calcium carbonate, calcium phosphate, and hydroxyapatite and collagen, at least a part of which is gelatinized; and then lyophilizing the resultant. The porous and composite materials obtained by the method of the present invention have large pore diameters, high porosities, and adequate mechanical strengths and biodegradability. Thus, they are suitable for implants such as bone fillers, drug carriers for sustained-release, and the like.

Abstract: An improved reusable writing tablet, having raised document guides that define a document support surface, and a method for affixing and removing a cover sheet over the document support surface, where said document guides define a means to allow the insertion of tabs defined by a cover sheet, so that a cover sheet is held securely in place, and is easily removable from the base to allow the placement of documents between said cover sheet and the document support surface, and where said documents are viewed through the cover sheet, and are prevented from sideways movement by the cover sheet and raised document guides.

Abstract: A learning aid permitting the student to insert a worksheet into a rigid body having space between two planes. One of the planes is clear permitting the instructor to mark on it, performing the work required by the underlying worksheet. The instructor's marking is erased and the student attempts the same task. The work sheet is secured in place by a clipboard. The clipboard rides in a slot to prevent scratching of the clear panel member. The clipboard may be secured in the slot by a latch mechanism.

Abstract: A flexible writing surface including a coated flexible substrate having a dust collecting cuff around the perimeter thereof to prevent the scattering of chalk dust during use.