Apparatus and techniques for the measurement of certain optical properties of ore minerals in reflected light

1957 ◽  
Vol 52 (3) ◽  
pp. 252-268 ◽  
Author(s):  
Eugene Nathan Cameron
Keyword(s):  
Optical Properties ◽  
Reflected Light ◽  
Ore Minerals

Optical Properties of Reflected Light From Leaves: A Case Study From One Species

2019 ◽  
Vol 57 (7) ◽  
pp. 4388-4406 ◽  
Author(s):  
Zhongqiu Sun ◽  
Di Wu ◽  
Yunfeng Lv ◽  
Shan Lu
Keyword(s):  
Optical Properties ◽  
Reflected Light

Thermal and photo optical properties of azoxybenzene/alkyloxy-azobenzene–cholesterol dimesogens with alkyl diacetylene linker

2005 ◽  
Vol 20 (12) ◽  
pp. 3431-3438 ◽  
Author(s):  
Subramanian Kumaresan ◽  
V. Ajay Mallia ◽  
Yoshishige Kida ◽  
Nobuyuki Tamaoki
Keyword(s):  
Optical Properties ◽  
Liquid Crystalline ◽  
Visible Region ◽  
Blue Shift ◽  
Isotropic Phase ◽  
Benzene Derivatives ◽  
Smectic A ◽  
Smectic Phases ◽  
Reflected Light ◽  
Liquid Crystalline Material

Thermal and photo-optical properties of azoxybenzene/alkyloxy-azobenzene containing chiral dimesogens are presented. Alkyloxyazobenzene containing dimesogenic materials exhibited two kinds of smectic A phases. Photoirradiation at temperatures exhibiting smectic phases of pure materials in azobenzene linked dimesogens resulted in formation of the isotropic phase, and this was systematically studied at different liquid crystalline temperatures. The efficacy of these compounds as a dopant in the glassy liquid crystalline material was also explored. Increasing concentration to 4 wt%/5 wt% in azobenzene/azoxy-benzene derivatives caused a dramatic red-shift in the wavelength of reflected light by the host cholesteric glassy liquid crystal. Photo-isomerization of these dopants led to a blue-shift of the reflected light, and this effect could be used to tune the light reflectivity of these mixtures over the visible region.

scholarly journals Biomedical optical properties of color light and near-infrared fluorescence separated-merged imager

2019 ◽  
Vol 12 (06) ◽  
pp. 1940001
Author(s):  
Rui Zhang ◽  
Ya-Zhou Xue ◽  
Xiao-Feng Yang
Keyword(s):  
Optical Properties ◽  
Near Infrared ◽  
Perioperative Period ◽  
Infrared Light ◽  
Agarose Gel ◽  
Near Infrared Fluorescence ◽  
Imaging Characteristics ◽  
Reflected Light ◽  
Wide Range

Objective: We study the biomedical optical properties of the color light and near-infrared fluorescence separated-merged imager. Materials and Methods: The color light and near-infrared fluorescence separated-merged imager can illuminate the visible light and the near-infrared light of [Formula: see text][Formula: see text]nm, receiving the reflected light and [Formula: see text][Formula: see text]nm near-infrared fluorescence, and display the color, fluorescence and merge image. ICG solution of different concentration, including standing time, was allocated to study the best imaging condition in vitro, and the depth of fluorescence penetration was studied with 5% agarose gel; the imaging characteristics of the imager was studied using SD rat; and then the SLNs tracing in 4 cases of penile carcinoma was performed. Results: When the concentration of ICG is 13.11[Formula: see text][Formula: see text]mol/L, the fluorescence intensity and the merge image are the best. The maximum depth of fluorescence imaging is 9[Formula: see text]mm in 5% agarose gel, while the bone has the greatest influence on it. The SLNs tracing shows that the imager can locate the SLNs in vitro, to achieve perioperative navigation during biopsy. Conclusion: There are many factors that affect the imaging effect, but the imaging effect of the imager meets the requirement of vision in a wide range, and can effectively trace the SLNs in perioperative period.

Some relationships between the reflectivities of sulphide ore-minerals

1933 ◽  
Vol 23 (143) ◽  
pp. 458-462 ◽  
Author(s):  
F. Coles Phillips
Keyword(s):  
Optical Properties ◽  
Rapid Development ◽  
Direct Determination ◽  
Quantitative Measure ◽  
Sulphide Ore ◽  
Ore Minerals ◽  
Reflection Of Light ◽  
Opaque Minerals ◽  
Made In

Since the early work of Dmde and others on the reflection of light by opaque crystalline media, little progress has been made in the direct determination of the indices of refraction and absorption for such substances. Interest in the optical properties of the opaque minerals, however, has been greatly stimulated by the rapid development in the last few years of the methods of ore-microscopy first brought into prominence by Campbell in 1906. Full theoretical discussions have been given recently by Berek, Koenigsberger, and others, but the only quantitative measure feasible in routine microscopy at present is that of the reflectivity.

A universal ore-polishing machine (With Plate XXI.)

1937 ◽  
Vol 24 (158) ◽  
pp. 595-600 ◽  
Author(s):  
F. C. Phillips
Keyword(s):  
High Speed ◽  
Soft Materials ◽  
Usual Procedure ◽  
Reflected Light ◽  
Ore Minerals ◽  
Polishing Machine ◽  
Grinding And Polishing

Available methods of grinding and polishing ore-minerals, in preparation for their examination with the ore-microscope in reflected light, fall into two categories. The more usual procedure, adapted from the corresponding methods in metallography, involves the use of high-speed laps faced with soft materials and supplied with relatively large quantities of abrasive mixed with water. The advantages of this method are its rapidity (about ten minutes will usually suffice for the whole series of processes), the possibility of using unmounted chips, and the simplicity of the necessary equipment. Amongst its chief disadvantages are the high relief developed between hard and soft minerals in the same specimen and the dirtiness of the process owing to the large amounts of wet sludge produced.

scholarly journals Ore Microscopy of the Pegmatites of Keffi Area, North Central Nigeria

2021 ◽  
Vol 2 (5) ◽  
pp. 34-40
Author(s):  
I. Y. Tanko ◽  
K. Dzigbodi-Adjimah
Keyword(s):  
Quantitative Analysis ◽  
Light Microscopy ◽  
Elemental Composition ◽  
North Central ◽  
Wavelength Dispersive Spectrometry ◽  
Reflected Light ◽  
Ore Minerals ◽  
Backscattered Electron ◽  
High Concentrations ◽  
Area North

Investigation of the pegmatites of Keffi area was carried out in reflected light microscopy to determine the texture, elemental composition, and the semi-quantitative analysis of the ore minerals from the three groups of pegmatites identified in Keffi area: the non-mineralised, the intermediate and the mineralised pegmatites. Backscattered Electron (BSE) images and Wavelength Dispersive Spectrometry (WDS) were used. Petrographically the portion which is characterised by profuse albitisation, sericitisation and silicification is also associated with the development of cleavelandite, lepidolite, coloured tourmaline and high concentrations of cassiterite and columbite-tantalite (coltan).The order of crystallisation in the pegmatites is from microcline to quartz followed by (plagioclases) oligoclase to albite and by mica (from biotite to muscovite) then by accessory minerals such as black tourmaline, garnet, beryl and lastly oxides of Sn-Nb-Ta. Sphene, rutile, zircon, apatite, ilmenite, and magnetite appeared to be earliest minerals whilst garnet pyrite and chalcopyrite may be syn-metamorphic. Beryl and coloured tourmaline appear to be of hydrothermal phase.

scholarly journals Výskyty hydrotermálnej Sb-Au mineralizácie na lokalitách Lomnistá, Husárka a Suchá dolina pri Jasení (Nízke Tatry)

2020 ◽  
Vol 28 (1) ◽  
pp. 210-218
Author(s):  
Štefan Čík ◽  
Martin Chovan ◽  
Juraj Majzlan
Keyword(s):  
Primary Sources ◽  
Two Phase ◽  
Alluvial Sediments ◽  
Secondary Minerals ◽  
Reflected Light ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Homogenization Temperatures ◽  
Rock Alteration ◽  
Phase Fluid

Ore mineralization in small Sb-Au occurrences Lomnistá, Husárka and Suchá dolina (Nízke Tatry Mts., Western Carpathians) was investigated by reflected-light microscopy, electron microprobe, fluid inclusion measurements, identification of host rock alteration and secondary minerals. Hydrothermal Sb-Au mineralization was formed during the arsenopyrite-pyrite-gold and stibnite-Pb-Sb-sulfosalts stages. The first stage of mineralization consists of arsenopyrite, pyrite, and quartz, but gold, typical for this stage in the Nízke Tatry Mts. is missing. Stibnite and zinkenite are dominant in the following stage in Lomnistá and Husárka. Berthierite and jamesonite are frequent in Suchá dolina. Other ore minerals identified here are sphalerite, chalcostibite, chalcopyrite, cinnabar, tetrahedrite-(Hg) at Lomnistá and Husárka and pyrrhotite, chalcostibite, tetrahedrite-(Fe), chalcopyrite, antimony, and gold in Suchá dolina. Identified secondary minerals are valentinite and stibiconite. Stibnite, gold, and other ore minerals were found in heavy-mineral fractions from alluvial sediments, pointing at short transport from the primary sources. Two quartz samples, thought to be related to stibnite or berthierite, contained two-phase fluid inclusions with salinity of 10 - 20 wt.% NaCl eq. The total homogenization temperatures are 230 - 330 ºC in Lomnistá and 200 - 260 ºC in Suchá dolina.

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