Stistaites of the South Urals

Research subject. Rare minerals of tin and antimony – stistaites from natural lead plates from the Severo-Svetlinskaya placer in the Chelyabinsk region and from microspherules of intermetallic compounds in the products of erosion of granites of the Kisegach complex in the Ilmeny Mountains.Materials and methods. Electron probe analysis and laser ablation with inductively coupled plasma were used to study the composition of the predominant minerals of intermetallic compounds in lead plates extracted during the washing of a gold-bearing placer, as well as from metal microspherules in the sandy fraction of eroded granites.Results. Two types of stistaite were identified: lead and arsenic-lead. Lead stistaites is sharply predominant, with its average composition (wt %) being Sb – 47.39, Sn – 38.75, Pb – 13.24, Cu – 0.06. The average composition of arsenic-lead stystaite (wt %) was found to be Sb – 43.89, Sn – 41.06, Pb – 11.02, As – 3.05, Cu – 0.47. Tin-lead microspherules from the destruction products of biotite granites of the Kisegach massif (Ilmeny Mountains) occasionally contain crystals and spotted precipitates of lead stistaite with the composition (wt %) of Sn 53.54, Sb 38.45, and Pb 7.42.Conclusions. It is assumed that, in both cases, the formation of alloys of intermetallic compounds of tin, lead and antimony with inclusions of native copper and iron was associated with granite magmatism.

Crystal Structure of an Anisotropic Pyrope Garnet That Contains Two Cubic Phases

The crystal structure of two different samples of pyrope garnet, ideally Mg3Al2Si3O12, from South Africa was refined using the Rietveld method, space group Ia3¯d, and monochromatic synchrotron high-resolution powder X-ray diffraction (HRPXRD) data. Sample 1 from Wesselton Mine is a single cubic phase and is optically isotropic. Electron-probe microanalysis (EPMA) provided an average composition {Mg2.30Fe2+0.26Ca0.42Mn2+0.02}∑3[Al1.53Fe3+0.06Cr3+0.40Ti4+0.01Fe2+0.01]∑2Si3O12, which contains a significant amount of Cr cations. The unit-cell parameter (Å) and bond distances (Å) are a = 11.56197(1) Å, average <Mg-O> = 2.2985, Al-O = 1.9101(4), and Si-O = 1.6343(3) Å. Sample 2 from De Beers Diamond Mine has an average composition {Mg2.33Fe2+0.33Ca0.33Mn2+0.01}∑3[Al1.73Fe3+0.12Cr3+0.06Ti4+0.05Fe2+0.05]∑2Si3O12 and is a fine-scale intergrowth of two cubic phases. The weight percentage, unit-cell parameter (Å), and bond distances (Å) for phase 2a are 62.2(1)%, a = 11.56185(1) Å, average <Mg-O> = 2.3006, Al-O = 1.9080(4), Si-O = 1.6334(4) Å. The corresponding values for phase 2b are 37.8(1)%, a = 11.53896(1) Å, average <Mg-O> = 2.2954, Al-O = 1.9020(6), Si-O = 1.6334(6) Å. The two cubic phases in sample 2 cause the crystal to be optically anisotropic because of strain induce birefringence. The unit-cell parameter and bond distances for sample 1 are similar to those in phase 2a.

Structure and chemical composition of grain boundaries in the magnetic semiconductor GaSb

The structure and chemical composition of grain boundaries in GaSb<Mn> magnetic semiconductors have been investigated. We determined that quenching of the GaSb melt with 2% Mn results in the formation of a textured polycrystal (111). The grain boundaries of the texture are formed by split 60 degree dislocations with <110> dislocation lines. Microinclusions based on the ferromagnetic compound MnSb are located on the stacking faults of split dislocations. The chemical compositions of microinclusions differ, but their average composition is close to Mn1.1Sb. The synthesized GaSb<Mn> is a soft ferromagnet with a coercive force of 10 Oe and a magnetic state approaching superparamagnetic

The indigenous settlement of Monte Iato (western Sicily): an ethnoarchaeometric approach for outlining local Archaic ceramic productions

An ethnoarchaeometric approach has been followed to identify the textural and compositional characteristics of the ceramic pastes produced in ancient Iaitas/Ietas, an indigenous site located in western Sicily on Monte Iato, a few tens of kilometres from Palermo. This approach was primarily motivated by the lack of discovered Archaic kilns or production sites/workshops and the inability to identify reference groups. Raw clays were sampled in the territory of San Cipirello and San Giuseppe Iato (today’s municipalities both sited on the northern slopes of Monte Iato), together with representative historic tiles and bricks locally produced until fairly recently. Grain-size analysis and experimental firings were performed on the clay samples. A significant number of archaeological ceramic samples (incised and painted indigenous pottery dating back to the seventh–fifth centuries BCE) from stratigraphic excavations on Monte Iato, and hypothesized as local productions on a stylistic-morphological basis, was carefully selected for archaeometric analysis. This set of samples (90 in total, comprising raw clays, historic tiles/bricks and archaeological ceramics) underwent a combined chemical and mineralogical-petrographic analysis to identify any possible compositional matching. This approach enabled the identification of minero-petrographic and chemical markers pertinent to the indigenous Archaic pottery produced at Monte Iato, although no evidence of coeval ceramic kilns has been found so far. Local raw clay sources have been documented and some significant points of the chaîne opératoire adopted in antiquity have been noted (clay mixing and tempering practices). Attesting Monte Iato as a centre of ceramic production and defining both the microscopic fabric and the average composition of local pastes open up new perspectives in the complex issue concerning the production and regional circulation of incised and painted indigenous ceramics in Archaic Sicily.

Comparison of a Traditional Landfill and a Mechanically-Biologically Treated waste Landfill (Case study; Kirkuk landfill)

Owing to the increasing population in Kirkuk, Iraq and the consequent rise in the production of waste, alongside with global warming caused by an increase in the greenhouse gases concentrations, a high level of emissions was observed at the landfill site near Kirkuk. These emissions can be transmitted by the wind over considerable distances and adversely affect the environment and individual health. In this study, two pilot scale columns were built to investigate different options for achieving sustainability by reducing long-term landfill emissions. Each reactor was packed with (8.5) kg of shredded synthetic solid waste (less than 5 cm) that was prepared according to an average composition of domestic solid waste in the city of Kirkuk. The main result of this study was that the pretreatment of the waste may shorten the transition time for active methane development and increase the methanogenesis of the landfill site and also affects COD removals efficiencies which were 19.11% and 66.53% for columns A and B respectively.

CALCULATION OF THE CONSTANTS OF COPOLYMERIZATION OF METHACRYLAMIDE WITHN-VINYLCAPROLACTAM

In this work, a copolymer of methacrylamide with N-vinylcaprolactam was synthesized for the first time by the method of radical copolymerization, based on the obtained values of the copolymerization constants, the dependence of the instantaneous and average composition of the copolymer was calculated. The relative activity constants r1 and r2 of methacrylamide and N-vinylcaprolactam monomers in the reaction of radical copolymerization have been calculated. The probability of the formation of different sequences of units during the formation of the copolymer was investigated. The variance of the compositional distribution was found to have a minimum at the azeatropic point.Key words:copolymerization, methacrylamide, N-vinylcaprolactam, monomer, copolymer, instant composition, average composition, modification, compositional heterogeneity, dispersion

The West African Dwarf Sheep II. Carcass Traits Mutton Quality

CARCASSES of thirty African Dwarf ewes had a yield of 42.5%, about 5 mm backfat thickness and a loin eye of about 8cm2 Primal cuts made up 85% of the carcass. The best carcasses came from ewes slaughtered between two and four years of age. Average composition of retail cuts was 66.5% muscle, 26.5% bone and 7.0% fat. Young ewes were superior to young rams both in dressing percent (yield) and primal cuts. The ewes dressed 44% as compared to 40%; their retail cuts contained 67% muscle and 26% bone against 65% and 28% respectively for rams. Compared with mutton sheep of the temperate zone the West African Dwarf stand only 4/5 as high and are 2/3 long, while weighing only 1/4 to 1/3 that of European sheep. Yet the leg, the preferred cut, was 36% of the dressed carcass is compared to European mutton.

3D phase diagrams and the thermal stability of two-component Janus nanoparticles: effects of size, average composition and temperature

We showed that in Janus nanoparticles the compositions of the formed phases depend on the radius, temperature and the average composition of the system, while the transition temperature depends on the average composition and radius of the particle.

Komposisi biota dasar hasil tangkapan alat garok pada perairan pesisir Kronjo, Tangerang

Garok is a fishing gear that operates at the bottom or surface of the substrate that is caught of various benthic species. The garok gear that operates in sediment, even in the long term can cause changes in the composition of the biota. Because exploitative fishing proses, can cause damage, vulnerability and at the long-term impact to the sustainability of the population. The research was carried out in Kronjo Bay, Tangerang from March to May 2011. The samples were collected from the operation, then determined the species, quantity, and weight of each species. Descriptive statistical analysis and ANOVA were used to determine the significance of the composition between stations and observation times. The caught consist of Placuna placenta, Anadara, Murex, Tellina, and crustaceans which belong to the mollusk and crustacean groups. Statistical analysis did not show a significant difference between the research stations, but it was significantly based on the observation time with Fhit 3,1 and Ftab 1,7. It turned out that the abundance of basic biota was found to be high in April then decreased in May. Likewise, the abundance did not show a significant difference in the location and time of observation. The catch composition on the Kronjo coast is dominated by the gastropod group with an average composition of above 50% per operation.Keywords:GarokCompositionDemersalKronjoCoastalABSTRAKGarok adalah alat tangkap yang dioperasikan di dasar perairan yang menangkap berbagai jenis biota dasar. Alat garok yang dioperasikan dapat menangkap beragam jenis biota dasar dan dalam jangka lama dapat menyebabkan terjadinya perubahan komposisi biota. Alat tangkap yang bersifat eksploitatif dapat menyebabkan kerusakan, kerentanan sehingga menganggu keberlanjutan populasi secara jangka panjang. Penelitian dari praktek penggunaan alat garok ini dilakukan di Teluk Kronjo Tangerang mulai Maret-Mei tahun 2011. Sampel dikumpulkan secara eskploratif dari operasi alat garok, kemudian tentukan jenis, jumlah dan bobotnya dari setiap jenis. Analisis statistik deskriptif dan ANOVA digunakan untuk mengetahui perbedaan komposisi antar stasiun dan antara waktu pengamatan. Hasil tangkapan terdiri dari jenis Placuna placenta, Anadara, Murex, Tellina, dan krustasea yang termasuk kelompok moluska dan krustasea. Analisis statistik tidak menunjukan perbedaan yang nyata antara stasiun penelitian, namun berbeda nyata berdasarkan waktu pengamatan dengan Fhit 3,1 dan Ftab 1,7. Kelimpahan biota dasar ditemukan tinggi pada bulan April kemudian menurun pada bulan Mei. Begitu juga kelimpahan tidak menunjukan perbedaan yang nyata pada lokasi dan waktu pengamatan. Komposisi tangkapan di pesisir Kronjo didominasi oleh kelompok gastropoda dengan komposisi rata-rata diatas 50% setiap kali operasi.Kata kunci:GarokKomposisiDemersalKronjoPesisir

Hydroxyplumbopyrochlore, (Pb1.5,□0.5)Nb2O6(OH), a new member of the pyrochlore group from Jabal Sayid, Saudi Arabia

ABSTRACTA new mineral species of the pyrochlore supergroup, hydroxyplumbopyrochlore (IMA2018-145), (Pb1.5,□0.5)Nb2O6(OH), has been discovered in the Jabal Sayid peralkaline granitic complex of the Arabian Shield, Saudi Arabia. It is associated with quartz, microcline, ‘biotite’, rutile, zircon, calcite, rhodochrosite, columbite-(Fe), goethite, thorite, bastnäsite-(Ce), xenotime-(Y), samarskite-(Y), euxenite-(Y), hydropyrochlore and fluornatropyrochlore. Hydroxyplumbopyrochlore usually shows euhedral octahedra, slightly rhombic dodecahedra and cubes or their combination (0.01–0.06 mm). The mineral is pale yellow to pale brown, transparent with white streak, and has adamantine to transparent lustre. It is brittle with conchoidal fracture. No cleavage or parting are observed. It is isotropic and non-fluorescent. The average microhardness is 463.4 kg mm–2. The calculated density is 6.474 g cm–3.Hydroxyplumbopyrochlore belongs to the cubic crystal system and exhibits the space group Fd$\bar{3}$m with unit-cell parameters a = 10.5456(6) Å, V = 1172.8(2) Å3 and Z = 8. Electron microprobe analysis gave (6-point average composition, wt.%): CaO 0.32, SrO 0.16, FeO 0.17, Ce2O3 0.07, Pr2O3 0.02, PbO 51.69, Nb2O5 40.06, SiO2 0.05, TiO2 1.68, Ta2O5 4.74, H2Ocalc 0.95, total 99.90, yielding the empirical formula (Pb1.34Ca0.03Fe0.01Sr0.01□0.61)Σ2(Nb1.75Ti0.12Ta0.12Si0.01)Σ2O6(OH0.53O0.08□0.39)Σ1, where □ = vacancy. The Raman spectrum of hydroxyplumbopyrochlore contains the characteristic bands of O–H vibrations and no bands for H2O vibrations.