Gallium

Neuroendocrine neoplasms (NENs) have variable biological behaviour​ but the majority exhibits a slow progression. Metastatic bone disease (mBD) in NENs is relatively uncommon and not well described albeit associated with an increased mortality.

Germanium, gallium and indium are in high demand due to their growing usage in high-tech and green-tech applications. However, the mineralogy and the mechanisms of concentration of these critical elements in different types of hydrothermal ore deposits remain poorly constrained. We investigated the mineralogical distribution of Ge, Ga and In at the Mt Carlton high-sulfidation epithermal deposit in NE Australia, using electron probe microanalysis and laser ablation inductively-coupled plasma mass spectrometry. Parageneses from which selected minerals were analyzed include: Stage 1 acid sulfate alteration (alunite), Stage 2A high-sulfidation enargite mineralization (enargite, argyrodite, sphalerite, pyrite, barite), Stage 2B intermediate-sulfidation sphalerite mineralization (sphalerite, pyrite, galena) and Stage 3 hydrothermal void fill (dickite). Moderate to locally high concentrations of Ga were measured in Stage 1 alunite (up to 339 ppm) and in Stage 3 dickite (up to 150 ppm). The Stage 2A ores show enrichment in Ge, which is primarily associated with argyrodite (up to 6.95 wt % Ge) and Ge-bearing enargite (up to 2189 ppm Ge). Co-existing sphalerite has comparatively low Ge content (up to 143 ppm), while Ga (up to 1181 ppm) and In (up to 571 ppm) are higher. Sphalerite in Stage 2B contains up to 611 ppm Ge, 2829 ppm Ga and 2169 ppm In, and locally exhibits fine colloform bands of an uncharacterized Zn-In mineral with compositions close to CuZn 2 (In,Ga)S 4. Barite, pyrite and galena which occur in association with Stage 2 mineralization were found to play negligible roles as carriers of Ge, Ga and In at Mt Carlton. Analyzed reference samples of enargite from seven similar deposits worldwide have average Ge concentrations ranging from 12 to 717 ppm (maximum 2679 ppm). The deposits from which samples showed high enrichment in critical elements in this study are all hosted in stratigraphic sequences that locally contain carbonaceous sedimentary rocks. In addition to magmatic-hydrothermal processes, such rocks could potentially be important for the concentration of critical elements in high-sulfidation epithermal deposits.

A 'critical metal' is one that has important economic uses, but which also faces supply risks for geopolitical or environmental and sustainability reasons. The constrained nature of critical metals supply means proposed solutions to the problem commonly involve reducing demand and therefore reliance, via recycling, substitution and thrifting. However, most critical metals are presently only small markets and therefore such an approach ignores the potential of transformational market growth to reduce supply risk, by creating large, diverse, transparent markets with multiple sources of primary mine supply, akin to modern base metals markets. Research is therefore required into which critical metals have the greatest potential for such transformational market growth. This study therefore conducts an evaluation of 49 critical metals to determine which are nearest to the combined breakthroughs in discovery, supply and demand that may lead to transformational market growth. The study concludes that 13 markets from the 49 critical metals, being magnesium, silicon, barium, boron, lithium, cobalt, chromium, vanadium, gallium, strontium, cerium, lanthanum and scandium have the highest potential for transformational market growth and thus efforts to resolve supply risk in these markets may be better focussed on overcoming current market constraints and growing these markets, rather than lessening reliance by reducing demand.

We have performed a density functional calculation for the centrosymmetric neodymium gallate using a full-potential linear augmented plane wave method with the LDA and LDA+U exchange correlation. In particular, we explored the influence of U on the band dispersion and optical transitions. Our calculations show that U = 0.55 Ry gives the best agreement with our ellipsometry data taken in the VUV spectral range with a synchrotron source. Our LDA+U (U = 0.55) calculation shows that the valence band maximum (VBM) is located at T and the conduction band minimum (CBM) is located at the center of the Brillouin zone, resulting in a wide indirect energy band gap of about 3.8 eV in excellent agreement with our experiment. The partial density of states show that the upper valence band originates predominantly from Nd-f and O-p states, with a small admixture of Nd-s/p and Ga-p B-p states, while the lower conduction band prevailingly originates from the Nd-f and Nd-d terms with a small contribution of O-p-Ga-s/p states. The Nd-f states in the upper valence band and lower conduction band have a significant influence on the energy band gap dispersion which is illustrated by our calculations. The calculated frequency dependent optical properties show a small positive uniaxial anisotropy.

Dislocations are one-dimensional topological defects that occur frequently in functional thin film materials and that are known to degrade the performance of InxGa1-xN-based optoelectronic devices. Here, we show that large local deviations in alloy composition and atomic structure are expected to occur in and around dislocation cores in InxGa1-xN alloy thin films. We present energy-dispersive X-ray spectroscopy data supporting this result. The methods presented here are also widely applicable for predicting composition fluctuations associated with strain fields in other inorganic functional material thin films.

In conventional photostimulable storage phosphors, the optical information written by x-ray or ultraviolet irradiation is usually read out as a visible photostimulated luminescence (PSL) signal under the stimulation of a low-energy light with appropriate wavelength. Unlike the transient PSL, here we report a new optical read-out form, photostimulated persistent luminescence (PSPL) in the near-infrared (NIR), from a Cr(3+)-doped LiGa₅O₈ NIR persistent phosphor exhibiting a super-long NIR persistent luminescence of more than 1,000 h. An intense PSPL signal peaking at 716 nm can be repeatedly obtained in a period of more than 1,000 h when an ultraviolet-light (250-360 nm) pre-irradiated LiGa₅O₈:Cr(3+) phosphor is repeatedly stimulated with a visible light or a NIR light. The LiGa₅O₈:Cr(3+) phosphor has promising applications in optical information storage, night-vision surveillance, and in vivo bio-imaging.

The production and application of PET tracers has been a unique step in the progress of nuclear medicine in last two decades. The most important PET tracers include F-18, C-11 and N-13 radioisotopes and many nuclear medicine centers throughout the globe are using them. However some new tracers are under their way to the mass administration, currently being in the clinical trials or preliminary studies. Gallium-66 and 68 tracers such as Ga-DOTANOC and Ga-DOTANIC are currently being used in many neuroendocrine tumor studies in human in Europe and North America, and global application of these tracers remain to the cheaper and easier providence of 68Ge/68Ga generators. Copper tracers such as 61,62,64Cu-ATSM and 61,62,64Cu-PTSM are the most important unconventional tracers used in hypoxia and perfusion studies respectively using PET technology. Copper tracers can easily be produced using a medium cyclotron with simple chemistry. Many other interesting PET radioisotopes such as Tc-94m (H...

Compact hyperspectral sensors potentially have a wide range of applications, including machine vision, quality control, and surveillance from small Unmanned Aerial Vehicles (UAVs). With the development of Indium Gallium Arsenide (InGaAs) focal plane arrays, much of the Short ...