Abstract: A 3D structure approximating a 3D curved surface having non-zero Gaussian curvature over a portion of the surface. The structure is formed of a plurality of thin strips (10) which are simply deformed and aligned adjacent one another to approximate the 3D curved surface. Each strip has: zero Gaussian curvature; a strip width which varies by no more than ±10% along a longitudinal axis of the strip; and a predetermined flat shape such that, after simple deformation, adjacent edges of adjacent strips can be aligned substantially parallel to one another separated by a substantially small gap. The aligned, simply deformed strips appear straight when viewed from a preferred viewing direction. The strips can be attached to a rigid support (12) at selected mounting points such that natural equilibrium deformation between the mounting points holds the aligned simply deformed strips in a desired approximation of the 3D curved surface.

Abstract: Driving circuits are provided that compensate for devices having characteristics that change with age. A correction circuit has a reference device having an output that changes with age in a known manner over a time span similar to the expected lifetime of the driven device. The output of reference device provides an indication of the current age of driven device.

Abstract: Solid state light sources are compatible with AC phase-cut dimmers. The light sources may have switching mode power supplies having primary and secondary sides that are in first and second circuit parts that are electrically isolated from one another. Information regarding a waveform of input electrical power is extracted in the first circuit part and passed to a controller in the second circuit part by way of a galvanic isolator. Additional isolated paths may be provided to provide bi-directional exchange of information between the first and second circuit parts and/or to provide for the exchange of additional information relevant to control. The signal path from the first side to the second side may have a low latency.

Abstract: A method of soil preparation simultaneously ploughs soil and tills soil ploughed in a previous pass. An apparatus for tilling soil provides tilling members mounted for deployment on either side of a tractor. The tilling members on one side of the tractor may be brought into engagement with the soil while tilling members on the other side of the tractor are lifted away from the soil. The tilling members are located to coincide with an adjacent strip of land ploughed in a previous pass of the tractor.

Abstract: A centrifugal concentrator in which there is a common shaft for the drive motor and concentrator bowl. The cost of bearing assemblies is thereby minimized. The bowl is driven and suspended from above to keep the motor out of the slurry area and maximize the simplicity of the design. A fluidizing fluid is delivered through the common shaft.

Abstract: Holding current circuits in light sources controlled by a dimmer are operated in a coordinated manner to maintain proper operation of the dimmer without wasting energy. A plurality of light sources each including a separate holding current circuit may be controlled by a dimmer. The holding current units are selectively disabled and/or a maximum holding current drawn by the holding current units are selectively adjusted to maintain a desired current draw.

Abstract: An apparatus and method for introducing portals into bone is described herein. An example apparatus for introducing portals into bone includes a handle, a base, and a driving member. The driving member can be made to project past the base by operating the handle. The base is detachable from the handle. The apparatus also includes a guide coupled at a first end to the handle and at a second end to the base. The base is detachably coupled to the guide. A base coupling detachably coupling the base to the guide includes an actuating member movable between a coupled configuration wherein the base is coupled to the guide and an uncoupled configuration wherein the base is released from the guide. The actuating member is arranged so that motion of the handle toward the base moves the actuating member from the coupled configuration to the uncoupled configuration.

Abstract: Methods and apparatus for classifying tissue use features of Raman spectra and background fluorescent spectra. The spectra may be acquired in the near-infrared wavelengths. Principal component analysis and linear discriminant analysis of reference spectra may be used to obtain a classification function that accepts features of the Raman and background fluorescence spectra for test tissue and yields an indication as to the likelihood that the test tissue is abnormal. The methods and apparatus may be applied to screening for skin cancers or other diseases.

Abstract: An underground drilling method where drilling fluid pulsing down hole tool is combined with a multiple in series pistons down hole tool to provide vigorous vibrations in the drill string and deliver vibrating energy to the drill bit to increase penetration rates and reduce friction between the drill string and the hole. One example method and apparatus shown can operate a simple percussive down hole mud hammer.

Abstract: Feeder protection apparatus comprising a plurality of side panels attached around a periphery of the base of the feeder by a plurality of fasteners. Each side panel comprises a generally rectangular sheet configured to be oriented generally perpendicular to the base when attached thereto and to extend above and below the base.

Abstract: Methods are provided for encoding watermark information into media data containing a series of digital samples in a sample domain. The method involves: dividing the series of digital samples into a plurality of sections in the sample domain, each section comprising a corresponding plurality of samples; processing the corresponding plurality of samples in each section to obtain a single energy value associated with each section; grouping the sections into groups, each group containing three or more sections; assigning a nominal bit value to each group according to a bit assignment rule, the bit assignment rule based on the energy values of the sections in the group; and assigning a watermark bit value to each group.

Abstract: A helmet is wearable on a user's head for mitigating neck injury. The helmet incorporates an outer member which defines a concavity; an inner member, at least a portion of which is located within the concavity; and a path-motion guide mechanism which couples the inner member to the outer member. The path-motion guide mechanism permits guided relative movement between the inner member and the outer member in response to an impact force. The guided relative movement is constrained to one or more predetermined paths and comprises, for each of the one or more predetermined paths, relative translation and/or rotation between the inner and outer members.

Abstract: Some introducer tools for bone portals have a handle coupled to a driving member by a force-limiting coupling. A bone portal comprising a bone-penetrating portion and a bone stop may be driven to a desired depth in bone when the force-limiting coupling allows application of force to the bone portal that is sufficient to drive the bone-penetrating portion of the portal into the bone but not sufficient to drive the bone stop significantly into the bone. Bone portals of various types are described herein. Various configurations for stylets suitable for use in introducing bone portals or otherwise penetrating bone and methods for inserting bone portals are also described herein.

Abstract: Apparatus for separating liquids, such as oils from solids, such as drill cuttings, comprises a decanter-type centrifuge. In example implementations the centrifuge has a bowl angle of four degrees or less and a low fluid depth of two inches or less. A material conveyor such as an auger is provided to carry material having a relatively high initial solids content, such as 50% or more into the centrifuge. The apparatus may comprise heaters to heat the material. In example implementations the decanter-type centrifuge processes solids from a main centrifuge and/or a shale shaker.

Abstract: Holding current circuits and lighting assemblies comprising same are provided. Holding current circuits may be connected to loads to ensure that the load and holding current circuit together draw at least a holding current from a dimmer when the dimmer is in conduction. A holding current circuit may comprise a controlled current source configured to selectively draw current from a dimmer. The controlled current source draws current according to a control signal based on the conduction state of the dimmer and the sum of the currents in a load and the controlled current source. The control signal is generated by a current controller configured to generate the control signal to cause the controlled current source to draw a supplementary current at least as great as the difference between the holding current and the load current when the dimmer is in conduction and the load current is less than the holding current.

Abstract: Methods and apparatus for maintaining sulfur concentration in the chemical recovery cycle of a Kraft pulping process. A portion of the recovery boiler ash is dissolved, treated to remove solids, and combined with an acid to provide a solution. The recovery boiler ash may be dissolved directly in the acid. The acid may be effluent from a chlorine dioxide generator. The resulting solution is maintained in a fully dissolved state and subjected to an acid separation step to provide a sodium sulfate enriched phase, which may be used to maintain sulfur concentration in the Kraft pulping process, and a sulfuric acid phase. Chlorine ions can be separated with the sulfuric acid phase. The sulfuric acid phase can be recycled to the chlorine dioxide generator.

Abstract: Methods and apparatus for assessing tissue pathology involve computing an index having a value based upon measures of a plurality of morphological features of cell nuclei in the tissue. The methods may be performed completely automatically or semi-automatically. The index value can be predictive of outcome. The index value may be determined by computing discriminant scores for the cell nuclei based upon values of the measures of morphological features and classifying the nuclei into bins based upon the discriminant score values. The index may be based upon proportions of the nuclei classified in different ones of the bins.