Abstract: The invention relates to an artificial tree that can be reduced in diameter by rotating its branches inward and along the length of the tree's trunk. The rotation of the branches is initiated by the rotation of the threaded inner core which is coaxially placed within the tree's outer trunk shell. This rotational motion is translated into a linear motion along the threaded inner core by the restriction of the rotational movement of a threaded branch translator placed on the threaded inner core. The restriction is caused by branch extenders pivotally attached to the branch translator and passing through openings located on the tree's outer trunk shell. The linear motion of the translator causes a multitude of pivotally attached branches radiating from the tree's trunk to rotate inward and along the tree's trunk. Thus, the diameter of the tree is reduced for easier transport and storage.

Abstract: A portable device that is placed between the ambient air outside an existing enclosed space and the existing enclosed space that pulls the ambient air through an interchangeable array of air cleaning modules and delivers the cleaned air from the air cleaning modules into the existing enclosed space. The air cleaning modules are disposed outside the existing enclosed space so that only cleaned air is drawn into the existing enclosed space. The air cleaning modules can also be capped for easy and safe disposal after use. The air cleaning modules are in fluid communication with an electric fan that is disposed inside the existing enclosed space through an air flow inlet that is part of an expandable window insert. Accordingly, the cleaned air delivered to the existing enclosed space provides its inhabitants with clean breathable air and increases the air pressure in the existing enclosed space which prevents contaminated air from the external environment from entering the existing enclose space.

Abstract: A refractory article such as a stopper used in the casting of molten metals that consists of a refractory core coated with an electrically conductive layer of carbon and graphite materials such that the stopper withstands the mechanical, chemical and thermal rigors of the casting operation and provides an effective electrical contact during the molten metal casting process.