Abstract: Recently, in terms of improving the yield and production rate of a biaxial-oriented polypropylene pearly synthetic paper, since the inorganic powder itself has an unsteady dispersion property while blended with polypropylene and while the extruder raises its production rate, which causes a shorter period of replacing the filter screen of the extruder; consequently, frequently replacing the filter screen deteriorates the efficiency of production, further obstructs the goal of increasing the yield from being achieved.

Abstract: A patch and method for mounting an electronic monitoring device to the innerliner of a pneumatic tire is provided wherein the monitoring device is potted directly to an attachment patch. A frame is built on an attachment patch and the electronic monitoring device is disposed inside the frame. An encapsulation material is poured into the frame and cured to encapsulate the monitoring device directly against the patch. The patch may then be connected to the innerliner of a pneumatic tire.

Abstract: A method and apparatus useful in the application of linerless labels to surfaces of elements is provided in a methodology so that conventional linered label applicators can be used with linerless labels. A source of linerless labels is provided comprising a composite of an elongate sheet of reusable, temporary liner having adhered to a low adhesion surface of said reusable, temporary liner an adhesive face of a precut linerless label, the composite possibly being in a roll.

Abstract: A method for positioning side panels during manufacture of a pant includes positioning the side panels within fluid flow devices. The side panels can move parallel or perpendicular to a pant transport plane as the pant is transported in the machine direction and the side panels reside within the fluid flow devices. The side panels can include refastenable fastening components. The method and apparatus can move the fastening components closer together in the cross-machine direction while the side panels reside within the fluid flow devices.

Abstract: A method of manufacturing an elasticized composite material including a multiplicity of elastic strips for use in garments, particularly in disposable absorbent articles is disclosed. The method includes the steps of folding the first substrate around the mandrel to form a tube while moving the tube longitudinally at a first velocity, and simultaneously winding at least one elastic strip around an outer surface of the tube at a second velocity to form a helical path. The elastic strip can be joined to the outer surface of the tube along the helical path to form a first composite tube. The method further includes the step of folding a second substrate around the first composite tube to cover the elastic strip and to form a second composite tube, which then can be slit longitudinally to form a planar composite material. Finally, the planar composite material can be activated to form the elasticized composite material.

Abstract: This invention is to prevent a substrate from dropping when it is transferred/received to/from a separating apparatus. The support surfaces of substrate holding portions (22, 23) are made horizontal, and a substrate (21) to be separated is mounted on one substrate holding portion (22) in a horizontal state (2A). The substrate holding portions (22, 23) are pivoted about rotary shafts (26, 27), respectively, to make the support surfaces of the substrate holding portions (22, 23) vertical so that the substrate (21) is sandwiched by the substrate holding portions (22, 23) (2B) The substrate holding portions (22, 23) are rotated about rotary shafts (24, 25), respectively, and simultaneously, high-pressure, high-speed water is ejected from an ejection nozzle (28) to separate the substrate (21) into two substrates (21a, 21c). The substrate holding portions (22, 23) are pivoted about the rotary shafts (26, 27), respectively, to make the support surfaces horizontal (2C).

Abstract: An apparatus for supplying chemicals in a chemical mechanical polishing (CMP) process includes a plurality of chemical solution supply sources for supplying different chemical solutions in a pump-less manner by using a pressure applied at the chemical solution supply sources, each supply source having an associated feed line, re-circulating line, and means for measuring and controlling flow rates of the chemical solutions supplied through the feed lines. The chemical solutions are delivered via a plurality of delivery lines to a mixer, thereby providing a mixed chemical solution to a chemical injection part of a polishing apparatus. Each means for measuring and controlling flow rates is mounted in the feed lines.

Abstract: Apparatus for controlling a thermal conductivity profile of a pedestal in a semiconductor wafer processing system. One embodiment of the apparatus is a thermal shim that is positioned between a wafer retention device (e.g., electrostatic chuck) and a pedestal. The shim controls the thermal conductivity between the wafer retention device and the pedestal. In one embodiment, the thermal shim has a low thermally conductive region and a high thermally conductive region. In a further embodiment, the low thermally conductive region is a hole. By having a hole in the center of the shim, thus forming an annulus, an air gap is formed between the wafer retention device and the pedestal such that less heat will be transferred through the air gap as compared to the high thermally conductive region of the shim.

Abstract: A wafer processing member having: a base material made of a material isotropic in all in-plane directions; and a ceramic film with which the base material is coated; wherein: the base material has a thickness of not larger than 3 mm; difference in coefficient of thermal expansion between the base material and the ceramic film is in a range of from 0.6×10−6 to 1.2×10−6/° C.; and variation in coefficient of thermal expansion of the base material in all in-plane directions is not larger than 0.05×10−6/° C.

Abstract: Splicer (1) for splicing to each other strips (30) of cords embedded in rubber material. The device comprises a supply transport device (2) for supplying strips in a supply direction. A splicing unit (6) splices strips to each other, and comprises a splicing table (7) and a splicing machine (8) placed over the splicing table. The supply transport device supplies strips to the splicing unit. A discharge transport device (11) discharges strips spliced to each other. A first (4) and a second (5) transport unit that are in line with each other are provided. The first transport unit (4) supplies strips to the second transport unit (5), in which the second unit supplies strips to the splicing unit and has an inlet end and an outlet end. The outlet end of the second transport unit and the splicing table are laterally, that means transverse to the transport direction, movable with respect to each other.

Abstract: Process for generating a homogeneous gas mixture of o-xylene and air for the production for the production of phthalic anhydride wherein o-xylene is completely evaporated in the absence of oxygen, superheated and then mixed with air and supplied to a phthalic anhydride reactor.

Abstract: A barrier includes a curtain vertically movable between a closed and open position. The curtain is interposed between right and left vertical tracks, which guide the curtain's movement. A drive unit raises and lowers a right edge of the curtain, while a clever strap system supports the curtain's left edge. The strap system includes a strap having one end fixed to an upper end of the left track and an opposite end fixed to a lower end of the right track. The strap runs across a leading edge of the curtain while passing across a left side roller and a right side roller mounted to opposite ends of the curtain's leading edge. The strap runs underneath the left roller to support the left side of the curtain. The strap runs across the top of the right roller to keep the strap from simply dropping out from underneath the left roller.

Abstract: A magnetic transmission system for an adjustable curtain installed inside a double pane window. Under full insulation condition of the double pane window, by use of two magnetic pieces separated by the glass, the rotation of the magnetic pieces will drive a pull cord, which will then effectively control and adjust the status of the curtain which is installed inside the window. The invention provides large transmission power in a small space. In addition to the typical thermal and acoustic insulation functions, the invention adds additional function of easy and flexible light adjustment. The invention can be widely used in different applications, such as standard home doors and windows, movable windows and large-scale windows, door and glass walls, skylights, etc.

Abstract: A pressure-vent hurricane shutter has predetermined requisite strength of shutter framework (1) encompassing slatted-louver apertures (4) for protection against storm-borne objects, wind and rain in addition to venting damaging buildups and bursts of pressure and vacuum that react on buildings from hurricanes. The shutter framework includes structural beams to which ends of slanted slats (5) are attached rigidly and to which ends of slat-support mullions (7) are affixed intermediate the ends of inward edges (6) of the slanted slats. The shutter framework is hinged with the requisite strength to at least one side of a building aperture in accordance with desired shutter style and structure which include top-hinged Bahama Shutters (8) and sides-hinged Colonial Shutters (9).

Abstract: A panel system comprises at least one bi-fold panel assembly (2, 3) of two panels hinged together along one edge (18) of each so as to be foldable thereabout, with at least one edge (20, 22, 24, 26) of the bi-fold panel assembly (2, 3) supported by a hinge device (30, 32, 34, 36) comprising two parallel pivot supports spaced apart in a plane orthogonal to pivot axes thereof, and a connecting link for in-situ connection therebetween. Hence the bi-fold panel assembly (2, 3) can be optionally connected in-situ by the connecting link to thereby obtain optional configurations of the panel system.

Abstract: A process is provided for preparing a commercially acceptable pharmaceutical grade microcrystalline cellulose which comprises: a) repulping a pulp, the pulp having a composition, b) pressing the pulp obtained in a; c) decompacting of the pulp obtained in b; d) feeding the pulp obtained in c) into a pre-heated reactor; e) cooking the pulp in the reactor until the pulp obtains a desired degree of polymerization, said cooking being performed at a temperature, a time, and a pressure which is a function of the desired degree of polymerization and the composition of the pulp, the cooked pulp being hydrolyzed cellulose; f) partially depressurizing the reactor; g) injecting water into the reactor; h) discharging the hydrolyzed cellulose from the reactor, i) filtrating the hydrolyzed cellulose; j) deaggregating the hydrolyzed cellulose of step i; and k) drying the hydrolyzed cellulose to form microcrystalline cellulose.

Abstract: In the feeding of a slurry of comminuted cellulosic fibrous material to a digester (continuous or batch) in the production of chemical pulp, one of the tanks used in the feed system (which preferably includes a high pressure feeder) may be eliminated without consequent loss of its function by providing a single tank with the combined functions of controlling the level of liquid in a slurrying conduit which supplies slurry to a slurry pump, and storing and substantially continuously supplying liquid to a make-up liquid pump connected to the digester. The single tank preferably surrounds the slurrying conduit and is substantially concentric, and in liquid communication, with it. A gap of 3-48 inches may be provided between the bottom of the conduit and a connection to the slurry pump. A screen or strainer may be provided in the gap, which is substantially surrounded by the tank.

Abstract: In the feeding of a slurry of comminuted cellulosic fibrous material to a digester (continuous or batch) in the production of chemical pulp, one of the tanks used in the feed system (which preferably includes a high pressure feeder) may be eliminated without consequent loss of its function by providing a single tank with the combined functions of controlling the level of liquid in a slurrying conduit which supplies slurry to a slurry pump, and storing and substantially continuously supplying liquid to a make-up liquid pump connected to the digester. The single tank preferably surrounds the slurrying conduit and is substantially concentric, and in liquid communication, with it. A gap of 3-48 inches may be provided between the bottom of the conduit and a connection to the slurry pump. A screen or strainer may be provided in the gap, which is substantially surrounded by the tank.

Abstract: In the feeding of a slurry of comminuted cellulosic fibrous material to a digester (continuous or batch) in the production of chemical pulp, one of the tanks used in the feed system (which preferably includes a high pressure feeder) may be eliminated without consequent loss of its function by providing a single tank with the combined functions of controlling the level of liquid in a slurrying conduit which supplies slurry to a slurry pump, and storing and substantially continuously supplying liquid to a make-up liquid pump connected to the digester. The single tank preferably surrounds the slurrying conduit and is substantially concentric, and in liquid communication, with it. A gap of 3-48 inches may be provided between the bottom of the conduit and a connection to the slurry pump. A screen or strainer may be provided in the gap, which is substantially surrounded by the tank.

Abstract: In the feeding of a slurry of comminuted cellulosic fibrous material to a digester (continuous or batch) in the production of chemical pulp, one of the tanks used in the feed system (which preferably includes a high pressure feeder) may be eliminated without consequent loss of its function by providing a single tank with the combined functions of controlling the level of liquid in a slurrying conduit which supplies slurry to a slurry pump, and storing and substantially continuously supplying liquid to a make-up liquid pump connected to the digester. The single tank preferably surrounds the slurrying conduit and is substantially concentric, and in liquid communication, with it. A gap of 3-48 inches may be provided between the bottom of the conduit and a connection to the slurry pump. A screen or strainer may be provided in the gap, which is substantially surrounded by the tank.

Abstract: In the feeding of a slurry of comminuted cellulosic fibrous material to a digester (continuous or batch) in the production of chemical pulp, one of the tanks used in the feed system (which preferably includes a high pressure feeder) may be eliminated without consequent loss of its function by providing a single tank with the combined functions of controlling the level of liquid in a slurrying conduit which supplies slurry to a slurry pump, and storing and substantially continuously supplying liquid to a make-up liquid pump connected to the digester. The single tank preferably surrounds the slurrying conduit and is substantially concentric, and in liquid communication, with it. A gap of 3-48 inches may be provided between the bottom of the conduit and a connection to the slurry pump. A screen or strainer may be provided in the gap, which is substantially surrounded by the tank.

Abstract: Process and container for stacking and diluting paper fiber stock. The process includes stacking a high-consistency stock in a first volume for defined dwell time, conveying stock to second volume arranged to adjoin downstream first volume, diluting stock in second volume at least to a pumpable consistency, and drawing off diluted stock as suspension through a wire. Process includes generating circulation flow in second volume, such that circulation flow facilitates conveying of stock located on boundary of first volume into second volume, diluting stock, and drawing stock through wire. Process includes rotating rotor to keep wire clear, and generating, with screw coil arranged directly in front of rotor, flow that runs in axial direction of screw coil and guides diluted suspension away from wire. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: A composition comprising an enzyme exhibiting laccase activity and an enzyme enhancing agent, also referred to as a mediator, is disclosed. A process for oxidizing a substrate that comprises treating the substrate with a composition comprising an enzyme exhibiting laccase activity and an enzyme enhancing agent is disclosed. The process when used on lignin-containing material bleaches the lignin-containing material. A process for enhancing the activity of an enzyme exhibiting laccase activity that comprises adding an enzyme enhancing agent to the enzyme is also disclosed.

Abstract: Pulping liquors used in the bleaching of pulps by hydrogen peroxide, and containing catalase-producing bacteria and/or catalase enzyme are treated with tris (hydroxymethyl) phosphine or a tetrakis (hydroxymethyl) phosphonium salt to kill the bacteria and destroy the enzyme.

Abstract: A method of controlling the degree of molding of a paper web during formation of a tissue product is provided. Initially, a liquid furnish of papermaking fibers is deposited onto a foraminous surface. The web is transferred to a through-drying fabric having a three-dimensional surface contour. In one embodiment, during transfer, the wet web is deflected onto the through-drying fabric so that it is molded to the surface contours of the fabric. The degree of molding is controlled by increasing or decreasing the solids consistency of the web without changing the deflection pressure or force.

Abstract: Soft throughdried tissues, which are sufficiently soft to serve as premium bathroom tissues, can be made without the use of a Yankee dryer. The typical Yankee functions of building machine direction and cross-machine direction stretch are replaced by a wet end rush transfer and the throughdrying fabric design, respectively. It is particularly advantageous to form the tissue with chemimechanically treated fibers in at least one layer. The resulting tissues have high bulk (about 6 cubic centimeters per gram or greater) and low stiffness.

Abstract: A decorative base paper for decorative coating materials contains a pigment mixture of titanium dioxide and talc, wherein the talc has a particle size distribution D50 of less than approximately 3.0 &mgr;m, and both the decorative base paper and the decorative paper have a high capacity.

Abstract: A system and method for altering the tack of a material, namely a polymer used as an adhesive, also known as stickies, or pitch. The present invention reduces the tack of the stickies and pitch by exposing the materials for a short duration to low-energy pulsed electrical discharges between a pair of electrodes that are submerged in a liquid medium, such as a fiber stream, water, a pulp slurry, or whitewater.

Abstract: The present invention is directed to a method and apparatus for fiberizing bales of pulp into substantially dry fibers and fiber aggregates, i.e., dry fluff, and metering the resulting dry fluff to a receptacle or other process, such as an airlaid process for making disposable absorbent articles.

Abstract: Device for controlling or regulating a basis weight of a web in a web manufacturing process of a web producing machine. The device includes a first control circuit, adapted to adjust the basis weight, that includes at least one adjustable device for influencing the basis weight and at least one basis weight sensor. A second control circuit having at least one sensor for detecting a concentration of incoming backwater is also provided. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: A web (W) passes through a press section having two separate press nips (N1, N2). At least the first press nip (N1) has two water-receiving press felts (31, 41). After the first nip (N1), the web (W) is separated from one press felt (31/41) and transferred on support of the opposite press felt (41/31) through the second press nip (N2). One roll of the first nip (N1) is a press suction roll (11, 110) and the web (W) is transferred to follow the press felt (31, 41) on the side of said press suction roll (11, 110) by means of an underpressure in a suction zone (11a, 110a) of said press suction roll (11, 110). The press felt (31, 41) on the side of the press suction roll (11, 110) is also passed through the second nip (N2) of the press section.

Abstract: A method and apparatus for melting metals uses microwave energy as the primary source of heat. The metal or mixture of metals are placed in a ceramic crucible which couples, at least partially, with the microwaves to be used. The crucible is encased in a ceramic casket for insulation and placed within a microwave chamber. The chamber may be evacuated and refilled to exclude oxygen. After melting, the crucible may be removed for pouring or poured within the chamber by dripping or running into a heated mold within the chamber. Apparent coupling of the microwaves with softened or molten metal produces high temperatures with great energy savings.

Abstract: A process for producing a tube target for cathode sputtering plants, in which the tube target is formed from a metallic inner tube (target holder) made of a first material with a first melting point of Ts1≧900 K and a metallic outer tube (target) that concentrically surrounds the inner tube and that is made of a second material with a second melting point of Ts2≦800 K. The inside diameter of the outer tube and the outside diameter of the inner tube are proportioned in such a way that the two tubes fit together tightly and are mechanically firmly joined. The outer tube is formed by casting the second material in a molten state in a heated, vertical, A cylindrical permanent mold, which has a heated mandrel that constitutes the inner tube.

Abstract: A heat exchanger for thermal energy engine comprises a hollow casing, a hollow top-plate, a hollow bottom-plate and a replaceable heat-exchanging medium. The hollow top-plate and the hollow bottom-plate have a plurality of air-ventilating orifices and arranged on a topside and a bottom side of the hollow casing, respectively. The replaceable heat-exchanging medium is placed within an accommodating space confined by the hollow casing, the hollow top-plate, and the hollow bottom-plate and provides heat-accumulation function to air flowing through the orifices and passing the heat-exchanging medium, whereby thermal loss is reduced.

Abstract: A thermal control device for controlling the temperature of a craft/spacecraft by means of an electrostatic switch to change the mode of heat transfer of the craft/spacecraft skin from conduction to radiation. The change is by means of a large change in apparent emissivity. The device can operate with moderate levels of DC voltages. Application of voltage results in high emissivity while removal of voltage results in low emissivity.

Abstract: An auxiliary engine generates electricity through an alternator, to charge the vehicle battery and selectively run an electric motor for air conditioning when the vehicle's primary engine is not operating. Operation of the electric motor produces rotation of the drive shaft of the vehicle's air conditioning compressor, the output shaft of the electric motor being connected via a centrifugal clutch, and a drive belt on a pulley integral to the clutch, to a pulley bolted directly to the drive shaft of the compressor. There is no use made of the vehicle's existing electromagnetic clutch at the compressor location, i.e. it remains disengaged when the auxiliary system is operating, and is engaged only when air conditioning is called for in normal vehicle operation, i.e. when the primary engine is running. The electricity generated by the auxiliary engine can also be used to operate other accessories, if desired, such as lighting, televisions, VCRs, refrigerators and other like accessories.

Abstract: A cooling apparatus has a low profile extrusion with a plurality of micro tubes extended there through. The low profile extrusion is placed into thermal connection with heat producing components. A heat transfer fluid removes heat via an adiabatic process.

Abstract: A method for removing heat from a heat generating component using a low profile extrusion with a plurality of micro tubes extended there through. The low profile extrusion is placed into thermal connection with heat producing components. A heat transfer fluid removes heat via an adiabatic process.

Abstract: A condenser includes a cooling section having a plurality of vapor passages to convert vapor into water, a blower for drawing water produced in the vapor passages out of the vapor passages, and a recovery section for receiving the drawn-out water. Thus, the water produced in the vapor passages in the cooling section can be prevented from occluding the vapor passages.

Abstract: A heat transfer tube for a falling film type evaporator, in which water spreading characteristics, particularly the water spreading characteristics in the tube axis direction, enhancing the heat transfer ability. Three types of projections 2, 3, and 4 are formed on an external surface 1a of a heat transfer tube body 1. A respective plurality of projections 2 to 4 are arranged spirally in parallel to one another, forming projection groups 2a to 4a. The number of each projection group 2 to 4 is one. Pitches P2 to P4 for the projections 2 to 4 are in the range of 0.35 mm≦P4<P3<P2≦5.95 mm. Heights h2 to h4 of the projections 2 to 4 are in the range of 0.1 mm≦h4<h3<h2≦0.5 mm. Pitches for the projection groups 2a to 4a is in the range of 0.72 to 1.12 mm.

Abstract: A heat sink of which cooling effect is excellent and which can prevent the decline of cooling quality due to the dust is provided. The heat sink comprises a box-like body attached to heat dissipating surface of heat dissipating element, a separation board separating the box-like body to upper and lower part, a number of side separation boards dividing the lower part into several areas, nozzle parts inserted to the side separation boards parallel to attaching surface, pin-like fins made at the bottom face in the several areas divided by the side separation boards and a air carrying means provided at upper area formed by the separation board for supplying cooling air to fins through the nozzle part.

Abstract: A shell-and-tube type heat exchanger of the smallest possible length necessary for heat exchange is disclosed which is capable of obtaining uniform distribution of flow of a shell side fluid and substantially eliminating the structural restriction imposed on the shell side. This shell-and-tube type heat exchanger is provided with one annular conduit furnished with not less than two partitions concurrently serving as an expansion joint for introducing and discharging a shell side fluid and allowing the flow path for said shell side fluid to be separated into an introducing part and a discharging part and which comprises a place having no array of heat-transfer tubes in the flow path for said shell side fluid. It prevents the equipment from necessitating an unnecessary enlargement due to the structural restriction on the shell side and enables the shell side fluid to produce a uniform flow.

Abstract: An incoming air duct (9) and an exhaust air duct (12) which connect an incoming air inlet (14) and an exhaust air outlet (10), respectively, in an outside side-wall (1b) to an incoming air outlet (13) and an exhaust air inlet (11) in a room-facing side wall (1a) are arranged side by side, separated only by partitions (8) of aluminium sheet, to permit heat exchange between the exhaust air flow and the opposite incoming air flow over a plurality of straight sections (6a, 6b, 6c, 6d, 6e) of a double duct which are connected by deflections (7a, 7b, 7c, 7d) of in each case 180°.

Abstract: A vehicle air conditioner selectively switches one of a cooling mode in which an interior heat exchanger of a refrigerant cycle is operated as an evaporator for cooling air, and a heating mode in which the interior heat exchanger is operated as a radiator for heating air. In the vehicle air conditioner, an accumulator, for separating gas refrigerant and liquid refrigerant from each other and for storing the separated liquid refrigerant therein, is disposed between an outlet of the interior heat exchanger and a suction port of a compressor. Further, the accumulator includes a heating device for heating the liquid refrigerant stored in the accumulator in the heating mode. Therefore, heating performance for heating air in heating mode can be efficiently improved.

Abstract: The invention relates to a borehole radar tool comprising, in a housing (2) a transmitting antenna and a receiving antenna both of which comprise, near the housing wall (2), a dipole antenna (8) and a reflector (10) opposite thereto. Also provided are an algorithm, method and apparatus for determining electromagnetic contrast information of a site into which electromagnetic fields (27) are emitted. Signals (29) generated by induction are intercepted and, using a back-projection algorithm including a suitable weighting factor, are converted into contrast information. The algorithm and/or method can be recorded in a computer program or on a data carrier. Also disclosed is a method of determining said weighting factor. The invention further provides a method and apparatus for subsurface surveys in which electromagnetic pulse signals are emitted.

Abstract: This invention is a sand screen comprising a base pipe with openings cut directly thereon. The size, shape, and configuration of the openings may be varied depending on the filtration, inflow, and strength characteristics desired by the operator. The openings may be cut directly on the base pipe by use of water jet, laser, or saw cutting techniques.

Abstract: A well completion has an expanded tubing portion and an unexpanded tubing portion. In another embodiment, an expandable tubing is provided and a gravel pack operation is performed. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: An apparatus (60) for absorbing a shock comprises a first tubular member (62) and a second tubular member (80) that are slidable positioned relative to one another. A plurality of layers (94-104) of energy absorbing members (88) extend radially from the second tubular member (80) such that movement of the second tubular member (80) in a first direction relative to the first tubular member (62) sequentially deforms the layers (94-104) of energy absorbing members (88). As the layers (94-104) are sequentially deformed, a subsequent layer (96) of energy absorbing members (88) begins to deform before the previous layer (94) of energy absorbing members (88) is completely deformed. The deformation of the energy absorbing members (88) absorbs the shock.

Abstract: A method and apparatus for controlling a transient underbalance condition is provided. Transient underbalance can be enhanced by using a porous material, such as a porous solid, around the explosive device. The porous material contains a volume to receive wellbore fluids in response to activation of the explosive device. This causes a local drop in pressure, which enhances the transient underbalance effect. In another application, it is desired to reduce the transient underbalance effect. This is accomplished by reducing the pressure drop generated as a result of explosive detonation. In one arrangement, the shot density is reduced by using solid masses.

Abstract: A method and apparatus for milling a window in a downhole structure, such as a casing or a liner, includes a mandrel that supports milling elements arranged in a predetermined pattern. In one example, the milling elements are arranged in one or more continuous channels each having a generally helical pattern. The milling elements are able to cut the window in the downhole structure substantially continuously to the desired size.