摘要:
Rotary drill bits for drilling subterranean formations include a bit body and at least one cutting structure disposed on a face thereof. The bit body includes a crown region comprising a particle-matrix composite material that includes a plurality of boron carbide particles dispersed throughout an aluminum or aluminum-based alloy matrix material. In some embodiments, the matrix material may include a continuous solid solution phase and a discontinuous precipitate phase. Methods of manufacturing rotary drill bits for drilling subterranean formations include infiltrating a plurality of boron carbide particles with a molten aluminum or aluminum-based material. In additional methods, a green powder component is provided that includes a plurality of particles each comprising boron carbide and a plurality of particles each comprising aluminum or an aluminum-based alloy material. The green powder component is at least partially sintered to provide a bit body, and a shank is attached to the bit body.
摘要:
The present invention relates to compositions and methods for forming a bit body for an earth-boring bit. The bit body may comprise hard particles, wherein the hard particles comprise at least one carbide, nitride, boride, and oxide and solid solutions thereof, and a binder binding together the hard particles. The binder may comprise at least one metal selected from cobalt, nickel, and iron, and, optionally, at least one melting point reducing constituent selected from a transition metal carbide in the range of 30 to 60 weight percent, boron up to 10 weight percent, silicon up to 20 weight percent, chromium up to 20 weight percent, and manganese up to 25 weight percent, wherein the weight percentages are based on the total weight of the binder. In addition, the hard particles may comprise at least one of (i) cast carbide (WC+W2C) particles, (ii) transition metal carbide particles selected from the carbides of titanium, chromium, vanadium, zirconium, hafnium, tantalum, molybdenum, niobium, and tungsten, and (iii) sintered cemented carbide particles.
摘要:
A wood recovery and de-leading system is provided for de-leading deconstructed wood into clean, sized, and optionally profiled stock. The system preferably includes a container such as a mobile trailer, having an inlet opening and an outlet opening disposed therein and housing a wood de-leading device. The system is particularly effective in that it can process an inletted woodpiece through to the outlet openings in a single automatic pass, while containing the hazardous waste for safe and efficient disposal. While the system is described for de-leading wood, it can be used to clean, size, and optionally profile any number of materials regardless of coatings thereon.
摘要:
Pharmaceutical compositions suitable for administration by inhalation and containing pentamidine, or pharmaceutically acceptable salt thereof, in powder form. Such compositions include pressurized aerosol compositions and non-pressurized powder compositions. Also described is finely divided powdered pentamidine with a mass median diameter in the range 0.01 to 10 microns and a method for the prevention or treatment of pneumacystics carinii pneumonia which comprises administration by inhalation to a patient having or susceptible to that condition of a therapeutically effective quantity of pentamidine, or a pharmaceutically acceptable salt thereof, in powder form.
摘要:
Isopropylbenzene derivatives having the general formula: ##STR1## in which: R.sup.1 to R.sup.4 independently represent a hydrogen atom or a lower alkyl group having up to 4 carbon atoms,X.sup..crclbar. represents COO.sup..crclbar. or SO.sub.3.sup..crclbar., andR.sub.f represents a fluorinated organic radical.The compounds may be applied to surfaces liable to be or become negatively charged to suppress spark discharges from such surfaces. Those compounds in which at least two of R.sup.2, R.sup.3 and R.sup.4 are alkyl, are particularly useful in the top coat of photographic films to eliminate marks caused by spark discharges.
摘要:
A method of treating a surface, e.g. carpet, gramophone record, to reduce the static charging thereon which comprises applying a novel antistatic composition comprising a fluorinated anionic surfactant which is an amine salt of an acid containing a fluorinated organic radical and an antistatic agent which is an ionic salt of an amine, preferably in alcoholic solution.
摘要:
A personal watercraft auto-return system includes a user device having a rider location determination unit, a user interface, and a communication unit. The system also includes an autopilot unit that is positioned within a personal watercraft. The autopilot unit including a steering unit for controlling the steering the watercraft, and a controller having a processor and memory for controlling the engine and throttle controls of the watercraft. The controller selectively activates the steering unit, engine, and throttle of the personal watercraft to navigate to the location of the user device upon receiving a request from the user interface.
摘要:
A portable easel for allowing a user to conveniently transport art supplies and a drawing surface to various locations. The portable easel includes an easel board removably and pivotally secured to a tripod base, wherein one or more legs of the tripod base are independently adjustable in length so as to allow for the easel to be positioned on an uneven support surface, such as a hill. Further, the tripod base may be folded into a compact configuration to conveniently transport the easel. The easel board is secured to the tripod base by a ball and socket connection, wherein the easel board can rotate thereon to allow a user to draw, paint, and the like at various angles. In some embodiments, the easel board includes one or more lights thereon so as to illuminate the drawing surface and a storage band removably securable to the easel board that can hold art supplies therein.
摘要:
A program for teaching forensic science may include physical devices or an online internet activity simulating a crime scene, preferably a crime scene based on a notable crime that has actually occurred and received some notoriety. A virtual classroom is provided which includes lessons in forensics and quizzes, a virtual lab to study evidence by the user, and an easy-to-use interface for teachers to manage their presentations and monitor the progress of students studying forensic science.
摘要:
A method of making an earth-boring rotary drill bit including a bit body configured to carry one or more cutters for engaging a subterranean earth formation. The method includes providing a plurality of hard particles in a mold to define a particle precursor of the bit body. The method also includes infiltrating the particle precursor of the bit body with a molten matrix material comprising a shape memory alloy forming a hard particle-molten matrix material mixture, wherein the hard particles are randomly dispersed within the molten matrix material. The method further includes cooling the molten matrix material to solidify a matrix material and form the bit body comprising a particle-matrix composite material having the plurality of hard particles randomly dispersed throughout the matrix material.