Electro-optical device for monitoring wire size

Device recognizes variations in wire size and is being used during computer memory-plane fabrication. Decrease in wire diameter, due to stretching, permits removal of wire from memory-plant mold. Monitoring provides means of detecting imperfect wire and permits fabrication of computer memory plane to be stopped prior to its insertion into mold

Automatic focus control for facsimile cameras

An electronic circuit for controlling the focus of facsimile cameras is described. The circuit consists of balanced a.c. amplifiers, two square law function generators, and a differential amplifier and power drive. The invention includes a method for maintaining the imaging sensor at the expected location of the focal plane as the facsimile camera scans a scene or terrain. A block diagram of the electronic circuitry is provided

Transmitting and reflecting diffuser

An ultraviolet grade fused silica substrate is coated with vaporized fused silica. The coating thickness is controlled, one thickness causing ultraviolet light to diffuse and another thickness causing ultraviolet light to reflect a near Lambertian pattern

Laser communication system for controlling several functions at a location remote to the laser

A multichannel laser remote control system is described. The system is used in areas where radio frequency, acoustic, and hardware control systems are unsatisfactory or prohibited and where line of sight is unobstructed. A modulated continuous wave helium-neon laser is used as the transmitter and a 360 degree light collector serves as the antenna at the receiver

Device for measuring the contour of a surface

Light from a source is imaged by a lens onto a surface so that the energy from the source is concentrated into a spot. As the spot across the surface is scanned, the surface moves relative to the point of perfect focus. When the surface moves away from perfect focus the spot increases in size, while the total energy in the spot remains virtually constant. The lens then reimages the light reflected by the surface onto two detectors through two different sized apertures. The light energy going to the two detectors is separated by a beam splitter. This second path of the light energy through the lens further defocuses the spot, but as a result of the different sizes of the apertures in each light detector path, the amount of defocus for each is different. The ratio of the outputs of the two detectors which are indicative of the contour of the surface is obtained by a divider

A transmitting and reflecting diffuser for ultraviolet light

Fabrication of ultraviolet radiation diffusing layer in configuration that uses ultraviolet properties of fused silica condensate is discussed. Construction and operation of the device are described. Diagram of reflecting diffuser to show construction and method of operation is included

Reflectance characteristics of the Viking lander camera reference test charts

Reference test charts provide radiometric, colorimetric, and spatial resolution references for the Viking lander cameras on Mars. Reflectance measurements of these references are described, including the absolute bidirectional reflectance of the radiometric references and the relative spectral reflectance of both radiometric and colorimetric references. Results show that the bidirection reflectance of the radiometric references is Lambertian to within + or - 7% for incidence angles between 20 deg and 60 deg, and that their spectral reflectance is constant with wavelength to within + or - 5% over the spectral range of the cameras. Estimated accuracy of the measurements is + or - 0.05 in relative spectral reflectance

Optical analysis of a compound quasi-microscope for planetary landers

A quasi-microscope concept, consisting of facsimile camera augmented with an auxiliary lens as a magnifier, was introduced and analyzed. The performance achievable with this concept was primarily limited by a trade-off between resolution and object field; this approach leads to a limiting resolution of 20 microns when used with the Viking lander camera (which has an angular resolution of 0.04 deg). An optical system is analyzed which includes a field lens between camera and auxiliary lens to overcome this limitation. It is found that this system, referred to as a compound quasi-microscope, can provide improved resolution (to about 2 microns ) and a larger object field. However, this improvement is at the expense of increased complexity, special camera design requirements, and tighter tolerances on the distances between optical components

An investigation of the facsimile camera response to object motion

A general analytical model of the facsimile camera response to object motion is derived as an initial step toward characterizing the resulting image degradation. This model expresses the spatial convolution of a time-varying object radiance distribution and camera point-spread function for each picture element in the image. Time variations and these two functions during each convolution account for blurring of small image detail, and variations between, as well as during, successive convolutions account for geometric image distortions. If the object moves beyond the angular extent of several picture elements while it is being imaged, then geometric distortion tends to dominate blurring as the primary cause of image degradation. The extent of distortion depends not only on object size and velocity but also on the direction of object motion, and is therefore difficult to classify in a general sense

Mineralogical and ion-exchange leaching study of a Rare Earth Element (REE) bearing ion-adsorption clay deposit

Rare earth elements (REEs), La to Lu including Y, are vital elements in manufacture of catalysts and metallurgical industries, and play a critical role in meeting future energy demands, such as through their use in permanent magnets in wind turbines. China has dominated more than 90 % of the REE market, with heavy REE (HREE) clay deposits in South China accounting for 35 % of their total REE output. This has prompted the evaluation of ion-adsorption clay (IAC) deposits in tropical regions outside China, namely Madagascar. Clay minerals such as kaolinite are part of the phyllosilicate class, containing structures of shared octahedral aluminium and tetrahedral silicon sheets. Isomorphous substitutions within the lattice leads to a charge imbalance, which accounts for negative charge on kaolinite, thus giving the ability to attract REE cations from aqueous solution to the surface of the clay particle. IAC deposits are formed from the tropical weathering of granite with REE enrichment from accessory minerals. IAC clay samples of two regolith profiles, the pedolith (A1) and saprock (A2, B and F) from northern Madagascar were collected and subjected to a suite of characterisation techniques to investigate the properties of the clay mineral. This included particle size distribution (PSD), X-ray fluorescence (XRF), X-ray diffraction (XRD), quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN), inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The geochemical leaching characteristics of the clay mineral were investigated using a sequential leaching program, targeting ion-exchangeable REE on kaolinite, halloysite, REEorganic matter and mineral phase. Ammonium sulphate leach experiments were conducted, varying the ionic strength to determine optimum leaching concentrations. Seawater is easily available at the coastal mine, therefore simulated seawater (NaCl) experiments were conducted with the addition of ammonium sulphate to improve the REE recovery. Compound leaching agents were investigated including varying magnesium / ammonium ratios in a sulphate system as well as ammonium in a varying nitrate / sulphate ratio system. The magnesium ion was investigated to correct the Mg deficiency in soils after leaching and the nitrate ion was investigated due to its high ionic permeability in kaolinite. Ion-adsorption clay leaching includes the leaching of impurities such as Al, Fe, Mg, K, Na, Ca and Mn. Ammoniumsulphate experiments with increasing amounts of ammonium acetate were conducted. Ammonium acetate acts a buffering agent to inhibit the leaching of the main impurity Al. The texture of sample A1 (5 to 6.5 m) was homogenous, with the QEMSCAN results showing Fe minerals distributed through the kaolinite, giving it a red appearance. The saprock samples A2, B and F have a heterogeneous texture due to the preservation of the primary texture. The QEMSCAN results show that this texture is composed of pure white kaolin, kaolin with red staining due to Fe minerals, tawny staining due to Al minerals and black phases containing Mn minerals. These Mn minerals show Ce deposited as the mineral cerianite, unavailable for ion-exchange. The pedolith sample was light REE (LREE) enriched but depleted in total REE (TREE = 1 503 ppm) compared with the saprock samples (TREE = 7 006 ppm on average). The saprock samples show LREE and HREE enrichment with samples A2 and F having La / Gd ratio of 17.4 and Gd / Lu ratios of 1.2. The more crystalline samples A2 and F (Hinckley index 0.40 and 0.44 respectively) are more REE enriched than the more weathered sample B (Hinckley index 0.32). The geochemical characterisation of sample A1 showed decreasing REE recovery from LREE to HREE from kaolinite whereas sample A2 showed consistent recovery across the REEs from kaolinite with both showing little Ce recovery. The best TREE recovery for samples A1 and A2 in the chloride system achieved with was NH4 + (44.3 % and 83.1 % respectively) followed by Na+ (39.5 % and 72.2 %) and Mg2+ (28.9 % and 72.1 % respectively). For sample A1 the recovery from the kaolinite fraction was 37.7 %, halloysite 5.1 %, organic 1.6 % and mineral 55.7 %. The proportion of ion-exchangeable REE is increased in sample A2 showing a recovery from the kaolinite fraction of 66.9 %, halloysite 12.7 %, organic 3.5 % and mineral 16.9 %. The results from increasing the ionic strength of ammonium sulphate shows that TREE leachant concentration increases as the concentration increases but decreases above 0.25 M. This indicates that the ammonium sulphate concentration saturates at 0.25 M and any further lixiviant increase eliminates access to the kaolinite surface. The simulated seawater experiments indicate that some addition of ammonium sulphate is beneficial as the addition of 0.05 M ammonium sulphate almost doubled the TREE leachant concentration. However excess addition of ammonium sulphate above 0.05 M had adverse effects on the leachant concentration of the LREEs. It was concluded from the compound leaching experiments that the Mg2+ ion can be used to supplement ammonium leaching with the greatest leachant concentration using a Mg2+:NH4 + ratio of 1:2 (equal charge). This ratio would produce a high REE leachant concentration while keeping Mg available for plants (flora). Compound leaching with the nitrate ion shows that the greatest REE leachant concentration was with a NO3 - :SO4 2- ratio of 2:1 (equal charge) due to increased nitrate ion permeability. The results from the addition of ammonium acetate as a buffer showed that the buffer inhibited the leaching of Al in both samples A1 and F, with the greatest inhibition at 0.05 M. The characterisation experiments illustrate the complexity of the in-situ clay deposit and further work should use this information to construct leaching models that take into account the heterogeneity of saprock samples. The leaching experiments show that compound leaching can improve REE recovery and further work should incorporate multiple lixiviants in in-situ leaching models