A. C. Roberts

ORCID: 0000-0002-1738-9898
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Research Areas
  • Crystal Structures and Properties
  • Mineralogy and Gemology Studies
  • Geological and Geochemical Analysis
  • X-ray Diffraction in Crystallography
  • Radioactive element chemistry and processing
  • Clay minerals and soil interactions
  • Chemical Synthesis and Characterization
  • Geochemistry and Geologic Mapping
  • Advanced Condensed Matter Physics
  • Solid-state spectroscopy and crystallography
  • Nuclear materials and radiation effects
  • Paleontology and Stratigraphy of Fossils
  • Polyoxometalates: Synthesis and Applications
  • Geochemistry and Elemental Analysis
  • Geological Studies and Exploration
  • Inorganic Fluorides and Related Compounds
  • Metal Extraction and Bioleaching
  • Crystal structures of chemical compounds
  • Methane Hydrates and Related Phenomena
  • Mathematics and Applications
  • Zeolite Catalysis and Synthesis
  • Organometallic Compounds Synthesis and Characterization
  • History and Theory of Mathematics
  • Advanced ceramic materials synthesis
  • Ureteral procedures and complications

Australian National University
2024

Autonomous Healthcare
2023

Geological Survey of Canada
2007-2021

University of Parma
2010

Lomonosov Moscow State University
2010

University of Canberra
2003

McGill University
1999

University of Waterloo
1998

The University of Texas Health Science Center at Houston
1996

University of Salzburg
1989

Recently others advocated frequent radiological surveillance to detect upper urinary tract deterioration in children with neurogenic bladder secondary spina bifida. We reviewed the consequences of such expectant management on compliance and continence.We retrospectively records 214 presenting our bifida clinic a 13-year period. Follow-up is available for 95 girls 86 boys. Imaging studies kidneys were repeated at 6 12-month intervals. Urodynamics performed when tracts deteriorated or...

10.1016/s0022-5347(01)65427-2 article EN The Journal of Urology 1996-12-01

Other| February 01, 1998 A systematic approach to general and structure-type formulas for minerals other inorganic phases Deane K. Smith; Smith Pennsylvania State University, Department of Geosciences, University Park, PA, United States Search works by this author on: GSW Google Scholar Andrew C. Roberts; Roberts Geological Survey Canada, Ottawa, ON, Canada Peter Bayliss; Bayliss Australian Museum, Sydney, N.S.W., Australia Friedrich Liebau Universitaet Kiel, Federal Republic Germany...

10.2138/am-1998-1-212 article EN American Mineralogist 1998-02-01

Tischendorfite, ideally Pd8Hg3Se9, is a new mineral species from the Eskaborner Stollen (Eskeborn Adit) at Tilkerode, Harz Mountains, Germany. It occurs as aggregates in carbonate matrix, together with associated metallic minerals clausthalite, tiemannite, chrisstanleyite, stibiopalladinite and gold. opaque luster, has black streak, brittle, fracture uneven. In plane-polarized reflected light, tischendorfite cream or slightly beige color association chrisstanleyite (light buff to gray-green...

10.2113/gscanmin.40.2.739 article EN The Canadian Mineralogist 2002-04-01

Abstract Chrisstanleyite, Ag 2 Pd 3 Se 4 , is a new mineral from gold-bearing carbonate veins in Middle Devonian limestones at Hope's Nose, Torquay, Devon, England. It associated with palladian and argentian gold, fischesserite, clausthalite, eucairite, tiemannite, umangite, arsenide-antimonide (possibly mertieite II), cerussite, calcite bromian chlorargyrite. Also present the assemblage phase similar to oosterboschite, two unknown minerals compositions, PdSe HgPd . Chrisstanleyite occurs as...

10.1180/002646198547611 article EN Mineralogical Magazine 1998-04-01

Abstract Mcalpineite, ideally Cu 3 TeO 6 ·H 2 O, occurs as isolated 0.5 mm-sized emerald green cryptocrystalline crusts on white quartz at the long-abandoned McAlpine mine, Tuolumne County, California, U.S.A. Associated nonmetallic phases are muscovite (mariposite), calcite, goethite, hematite, chlorargyrite, choloalite, keystoneite, mimetite, malachite, azurite, annabergite and a host of unidentified crusts, both crystalline amorphous. metallic minerals include pyrite, acanthite, hessite,...

10.1180/minmag.1994.058.392.07 article EN Mineralogical Magazine 1994-09-01

Eldragonite, with the simplified formula Cu 6 BiSe 4 (Se 2 ), is a new mineral species discovered in telethermal vein-type deposit selenides at El Dragon mine, Province of Quijarro, Department Potosi, Bolivia. It forms inclusions krut’aite, and associated clausthalite, klockmannite, umangite tiemannite, as well watkinsonite, petrovicite two unnamed phases system Cu–Pb–Hg–Bi–Se. The unique vein eldragonite-bearing krut’aite hosted within sandstones shales Devonian age. Eldragonite occurs...

10.3749/canmin.50.2.281 article EN The Canadian Mineralogist 2012-04-01

Abstract Verbeekite, ideally PdSe 2 , monoclinic with space-group choices C 2/ m or ; a = 6.659(7), b 4.124(5), c 4.438(6) Å, ß 92.76(3)°, V 121.7(4) Å 3 : 1.6147:1:1.0761, Z 2, is new, very rare, primary mineral, intimately associated secondary oosterboschite {(Pd,Cu) 7 Se 5 }, from the Musonoi Cu-Co-Mn-U mine, near Kolwezi, Shaba Province, Democratic Republic of Congo. Additional minerals are Cu- and Pd-bearing trogtalite {(Co,Cu,Pd)Se Se-bearing digenite covellite. The strongest five...

10.1180/0026461026610020 article EN Mineralogical Magazine 2002-02-01

La catamarcaite, de composition ideale Cu 6 GeWS 8 , a ete decouverte dans un minerai riche en bomite les haldes la veine dite Rosario, du gisement epithermal Capillitas, province Catamarca, Argentine. Lui sont associes bornite, digenite, chalcocite, covellite, sphalerite, hubnerite, luzonite, wittichenite, plusieurs sulfures porteurs Ge (putzite, Fe 2 ZnGe S 12 sans nom, et une phase ressemblant briartite) le quartz. catamarcaite se presente lisere long cavites fractures chalcocite-bomite,...

10.2113/gscanmin.44.6.1481 article FR The Canadian Mineralogist 2006-12-01

La putzite, dont la composition chimique est (Cu 4 . 7 Ag 3 ) Σ 8 GeS 6 , une -nouvelle espece minerale decouverte dans des haldes pres de veine Rosario, camp minier Capillitas, departement d'Andalgala, province Catamarca, en Argentine. diatreme Capillitas situee au sein du complexe volcanique FarallOn Negro, qui renferme gisements volumineux type Cu-Au associes a systemes porphyriques (Bajo Alumbrera, Agua Rica) et epithermaux veines. L'assemblage mineraux contient putzite comprend bornite,...

10.2113/gscanmin.42.6.1757 article FR The Canadian Mineralogist 2004-12-01

Tarkianite, a new mineral species of ideal composition (Cu,Fe)(Re,Mo) 4 S 8 , was recently discovered in sulfide concentrate from the Hitura Ni-Cu-PGE mine, Nivala, western central Finland.It is associated with pyrrhotite, pentlandite, valleriite, chalcopyrite, cubanite, mackinawite, chromite, and PGE minerals sperrylite, michenerite, irarsite, froodite hollingworthite.It black, opaque metallic luster, black streak, brittle an irregular fracture.VHN 15 range 537-584, which corresponds to...

10.2113/gscanmin.42.2.539 article EN The Canadian Mineralogist 2004-04-01

The structure of a new mineral jadarite, LiNaSiB 3 O 7 (OH) (IMA 2006–36), has been determined by simulated annealing and Rietveld refinement laboratory X-ray powder diffraction data. contains layer corner-sharing, tetrahedrally coordinated Li, Si B forming an unbranched vierer single layer, which is decorated with triangular BO groups. Na ion situated between the tetrahedral layers in distorted octahedral site. As very high boron content this makes obtaining neutron data problematic, ab...

10.1107/s0108768107010130 article EN Acta Crystallographica Section B Structural Science 2007-05-16

Ferroericssonite, ideally BaFe 2+ 2 Fe 3+ (Si O 7 )O(OH), is a new mineral species found at both the Esquire #7 and #8 claims, situated along Big Creek in eastern Fresno County, also Trumbull Peak Mariposa California, U.S.A. The analogue of ericssonite named accordingly. Ferroericssonite crystallized very late sequence minerals resulting from fluids interacting with quartz−sanbornite vein its margin country rock. It closely associated anandite, bazirite, celsian, devitoite, quartz...

10.3749/canmin.49.2.587 article EN The Canadian Mineralogist 2011-04-01

Abstract The ideal formula for members of the cerchiaraite group is Ba 4 M (Si O 12 )O 2 (OH) C l2 [Si 3 ], where represents Mn 3+ , Fe or Al in octahedral site. A suffix-based naming scheme used which original renamed cerchiaraite-(Mn) and two new minerals are named cerchiaraite-(Fe) cerchiaraite-(Al). type localities Cerchiara mine, Liguria, Italy Esquire No. 7 8 claims, Big Creek, Fresno County, California, USA. cerchiaraite-(Al) 1 claim, Rush USA claims noted above. At occurs small...

10.1180/minmag.2013.077.1.07 article EN Mineralogical Magazine 2013-02-01

Abstract High-resolution acoustic imaging technology has been developed and deployed to map the downhole location orientation of fiber optic lines in unconventional oil gas carbon capture wells. Fiber installations are long term monitoring solutions providing continuous measurement temperature, sound, or strain. These provide significant insight into operation optimization assets but require a large capital investment, typically upwards million dollars. By accurately mapping lines, operators...

10.2118/217819-ms article EN SPE Hydraulic Fracturing Technology Conference and Exhibition 2024-01-30

La burnsite, dont la formule ideale est KCdCu 7 O 2 (SeO 3 ) Cl 9 , a ete decouverte dans une fumerolle breche du Nord de grande eruption fissurale volcan Tolbachik (1975-1976), peninsule Kamchatka, en Russie. Elle se presente grains rouge fonce, xenomorphes, equidimensionnels. Lui sont associes cotunnite, sophiite, chloromenite, georgbokiite, ilinskite et un selenite Cu-Pb non defini. burnsite consideree rarissime, n'ayant trouvee que quelques douzaines qui ne depassent pas 0.1 mm....

10.2113/gscanmin.40.4.1171 article FR The Canadian Mineralogist 2002-08-01

Brodtkorbite, ideally Cu2HgSe2, a new mineral species, occurs in telethermal selenide vein-type assemblage at the Tuminico Ia selenium deposit, Sierra de Cacho (Sierra Umango) district, La Rioja, Argentina. The also contains berzelianite, bellidoite, cadmoselite (mercurian, cuprian), chameanite, crookesite, eskebornite, eucairite, ferroselite, hakite, klockmannite, luanheite-type phase, trogtalite-kruťaite, tiemannite, tyrrellite, umangite and uraninite. Minor constituents are undefined...

10.2113/gscanmin.40.1.225 article EN The Canadian Mineralogist 2002-02-01
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