Ree Group Research Articles

Rare-earth mineralization in terrigenous deposits of the Shatak complex (Southern Urals): species diversity and features of chemical composition

As a result of the study of terrigenous rocks of the Shatak complex, which includes deposits of the Kuz’elga and Karan subformations, rare earth minerals were found: allanite-(Ce), monazite-(Se), monazite-(Nd), xenotime-(Y), REE-bearing epidote, and unidentified connections. It has been established that during the metamorphism of terrigenous rocks of detrital zircon, it is a selective concentrator and thorium, a popular group of rare earth elements and thorium. The comparative analysis showed that, in terms of chemical composition, rare-earth minerals (monazite-(Ce) and xenotime-(Y)) from the Shatak rock are significantly important from heavy ones from other complexes observed on the western slope of the Southern Urals by the presence of gadolinium in monazite, and in xenotime – consecutive REE group represented by Ce, Nd and Sm. When calculating the thermal bar, characterizing changes in the composition of structural-material complexes of western origin, slopes from the main factors that determine the characteristics of the chemical composition of rare earth chemical elements, which are the chemical composition of mineral formation.

RARE EARTH ELEMENT RESOURCE POTENTIAL OF SUPER-LARGE DEPOSITS IN EASTERN FENNOSCANDIA

Work has been carried out to assess the rare-earth potential of the main ore minerals -loparite, eudialyte and apatite of the Lovozersky and Khibinsky deposits. Super-large deposits of loparite and eudialyte are associated with the giant Lovozero intrusion (Eastern Fennoscandia, Kola Peninsula). There are a number of apatite deposits in the Khibiny complex. All these ores occupy a leading place in the structure of the raw material of Russia. The highest contents of the sum of rare earth metals are characteristic of loparite ores (the content of ΣREE in loparites is about 28 wt%), and light rare earths sharply prevail over heavy ones, the Ce/Yb ratio is about 78 000. The amount of REE in eudialites is about 2 by mass%. A remarkable feature of eudialyte ores is the high concentrations of the heavy REE group, the Ce/Yb ratio is about 14. The apatites of the Khibiny deposits occupy an intermediate position: the Ce/Yb ratio is 680, and the average concentration of the REE sum is 0.9 wt%. The conditions of formation of apatite, loparite and eudialyte ores are considered.

Rare Earth Elements in the Shok-Karagay Ore Fields (Syrymbet Ore District, Northern Kazakhstan) and Visualisation of the Deposits Using the Geography Information System

Rare earth elements deposited in ion-adsorption clay-type deposits in Northern Kazakhstan were recognised using mineralogical and geochemical methods. The diversity and mineralogical properties of the Shok-Karagay deposit and Syrymbet ore fields under investigation in this study are closely related to the process of the formation of the deposits as well as the deposits’ architecture. A combination of mineralogical research and digital technology (GIS) was used to characterise the deposits. Rare earth elements from the cerium series were found in the following quantities: La (in ppm), 43–200; Ce, 57–206; Sm, 100–300; Eu, 22–100. Yttrium-series elements were found in the following quantities: Y, 31–106; Gd, 100–200; Tb, 100–200; Dy, 0–300; Ho, 0–20; Er, 0–364; Tm, 0.28–0.85; Yb, 2.2–39; Lu, 0–200. The wireframe and block models indicated that the bodies’ forms were 1800 m wide, 3500 m long, and 20–40 m thick. The major REE group minerals in both bodies were monazite and xenotime, whereas the minor minerals included yttrium parisite, silicorabdophanite, thorite, and orangite; moreover, ilmenite and titanomagnetite were found. The 3D models that were constructed indicated that the mineralogy and geochemistry of the ore bodies played a determining role in the deposits’ architecture.

RECOGNISING REE GROUPS USING THE CODEGREE SET

AbstractThe codegree of an irreducible character $\chi $ of a finite group G is $|G : \ker \chi |/\chi (1)$ . We show that the Ree group ${}^2G_2(q)$ , where $q = 3^{2f+1}$ , is determined up to isomorphism by its set of codegrees.

On the cohomology of the Ree groups and kernels of exceptional isogenies

Let G be a simple, simply connected algebraic group over an algebraically closed field k of characteristic p>0. Let σ:G→G be a surjective endomorphism of G such that the fixed point set G(σ) is a Suzuki or Ree group. Then, let Gσ denote the scheme-theoretic kernel of σ. Using methods of Jantzen and Bendel–Nakano–Pillen, we compute the 1-cohomology for the Frobenius kernels with coefficients in the induced modules, H1(Gσ,H0(λ)), and extensions between the simple modules, ExtGσ1(L(λ),L(μ)). When G(σ) is a Ree group of type F4, these results are used to improve the known bounds for identifying extensions of simple modules in defining characteristic ExtG(σ)1(L(λ),L(μ)) with those for the algebraic group.

On flag‐transitive 2‐(k2,k,λ) $({k}^{2},k,\lambda )$ designs with λ∣k $\lambda | k$

AbstractIt is shown that, apart from the smallest Ree group, a flag‐transitive automorphism group of a 2‐ design , with , is either an affine group or an almost simple classical group. Moreover, when is the smallest Ree group, is isomorphic either to the 2‐ design or to one of the three 2‐ designs constructed in this paper. All the four 2‐designs have the 36 secants of a non‐degenerate conic of as a point set and 6‐sets of secants in a remarkable configuration as a block set.

Cr-pyrope xenocrysts with oxide mineral inclusions from the Chompolo lamprophyres (Aldan shield): Insights into mantle processes beneath the southeastern Siberian craton

AbstractPyrope xenocrysts (N = 52) with associated inclusions of Ti- and/or Cr-rich oxide minerals from the Aldanskaya dyke and Ogonek diatreme (Chompolo field, southeastern Siberian craton) have been investigated. The majority of xenocrysts are of lherzolitic paragenesis and have concave-upwards (normal) rare earth element (REEN) patterns that increase in concentration from light REE to medium–heavy REE (Group 1). Four Ca-rich (5.7–7.4 wt.% CaO) pyropes are extremely low in Ti, Na and Y and have sinusoidal REEN spectra, thus exhibiting distinct geochemical signatures (Group 2). A peculiar xenocryst, s165, is the only sample to show harzburgitic derivation, whilst demonstrating a normal-to-weakly sinusoidal REEN pattern and the highest Zr (93 ppm) and Sc (471 ppm). Chromite–magnesiochromite, rutile, Mg-ilmenite and crichtonite-group minerals comprise a suite of oxide mineral inclusions in the pyrope xenocrysts. These minerals are characteristically enriched in Cr with 0.6–7.2 wt.% Cr2O3 in rutile, 0.7–3.6 wt.% in Mg-ilmenite and 7.1–18.0 wt.% in the crichtonite-group minerals. Complex titanates of the crichtonite group enriched in large ion lithophile elements (LILE) are high in Al2O3 (0.9–2.2 wt.%), ZrO2 (1.5–5.4 wt.%) and display a trend of compositions from the Ca–Sr-specific varieties to the Ba-dominant species (e.g. lindsleyite). In the pyrope xenocrysts the oxides coexist with silicates (clino- and orthopyroxene and olivine), hydrous silicates (talc, phlogopite and amphibole), carbonate (magnesite), sulfides (pentlandite, chalcopyrite, breakdown products of monosulfide and bornite solid solutions), apatite and graphite. P–T estimates imply the inclusion-bearing pyrope xenocrysts have been derived from low-temperature peridotite assemblages that resided at temperatures of ~600–800°C and a pressure range of ~25–35 kbar in the graphite stability field. Pyrope genesis is linked to the metasomatic enrichment of peridotite protoliths by Ca–Zr–LILE-bearing percolating fluid–melt phases containing significant volatile components. These metasomatic agents are probably volatile-rich melts or supercritical C–O–H–S fluids that were released from a Palaeo-subduction slab.

Effects of enteral nutrition with different energy supplies on metabolic changes and organ damage in burned rats.

Enteral nutrition (EN) is an important treatment for burn patients. However, severe gastrointestinal damage caused by major burns often leads to EN intolerance. Trophic EN solves this problem basically, but how to transition from trophic EN to standard EN smoothly is still a challenge in burn clinical nutrition. The aim of this study is to investigate the effects of EN with different energy supplies on metabolic changes, organ damage and prognosis in burned rats. Different feeding regimens were designed based on the continuous monitoring of resting energy expenditure in rats. Thirty-two Sprague-Dawley rats were randomly divided into a normal control group, burn +50% REE group, burn +75% REE group and burn +100% REE group. At the end of a nutritional treatment cycle (14th day), nuclear magnetic resonance spectroscopy, blood biochemistry analysis and quantification of subscab bacteria were performed to explore the differences in metabolic changes, degrees of organ damage and prognoses between the groups. Sixteen metabolites involving seven metabolic pathways were identified from the different energy supply groups. After burn injury, resting energy consumption and body weight loss increased obviously. Meanwhile, weight loss was inversely related to energy supply. The greatest changes in the degree of organ damage, the level of plasma proteins, lipids and endotoxins, as well as the quantification of subscab bacteria were observed in the 50% REE group, followed by the 75 and 100% groups. Achieving an early balance between energy supply and expenditure is conducive to mitigating metabolic disorders and improving prognosis after burn injury.

Moufang sets generated by translations in unitals

AbstractWe consider unitals of order with two points which are centers of translation groups of order . The group generated by these translations induces a Moufang set on the block joining the two points. We show that is either (as in all classical unitals and also in some nonclassical examples), or , or a Suzuki, or a Ree group. Moreover, is semiregular outside the special block.

On maximal embeddings of finite quasisimple groups

If a finite quasisimple group G with simple quotient S is embedded into a suitable classical group X through the smallest degree of a projective representation of S, then is a maximal subgroup of X, up to two series of exceptions where S is a Ree group, and four exceptions where S is sporadic.

Neurobehavioral Effects of Restricted and Unpredictable Environmental Enrichment in Rats.

To study how motivational factors modulate experience-dependent neurobehavioral plasticity, we modify a protocol of environmental enrichment (EE) in rats. We assumed that the benefits derived from EE might vary according to the level of incentive salience attributed to it. To enhance the rewarding properties of EE, access to the EE cage varied randomly from 2 to 48 h for 30 days (REE). The REE group was enriched only 50% of the time and was compared to standard housing and continuous EE (CEE) groups. As behavioral readout, we analyzed the spontaneous activity and the ultrasonic vocalizations (USVs) within the EE cage weekly, and in the open field test at the end of the experiment. In the cage, REE increased the utilization of materials, physical activity, and the rate of appetitive USVs. In the OF, the CEE-induced enhancements in novelty habituation and social signaling were equaled by the REE. At the neural level, we measured the expression of genes related to neural plasticity and epigenetic regulations in different brain regions. In the dorsal striatum and hippocampus, REE upregulated the expression of the brain-derived neurotrophic factor, its tropomyosin kinase B receptor, and the DNA methyltransferase 3A. Altogether, our results suggest that the higher activity within the cage and the augmented incentive motivation provoked by the REE boosted its neurobehavioral effects equaling or surpassing those observed in the CEE condition. As constant exposures to treatments or stimulating environments are virtually impossible for humans, restricted EE protocols would have greater translational value than traditional ones.

Flag-Transitive Non-Symmetric 2-Designs with $(r, \lambda)=1$ and Exceptional Groups of Lie Type

This paper determines all pairs $(\mathcal{D},G)$ where $\mathcal{D}$ is a non-symmetric 2-$(v,k,\lambda)$ design with $(r,\lambda)=1$ and $G$ is the almost simple flag-transitive automorphism group of $\mathcal{D}$ with an exceptional socle of Lie type. We prove that if $T\trianglelefteq G\leq Aut(T)$ where $T$ is an exceptional group of Lie type, then $T$ must be the Ree group or Suzuki group, and there are five classes of designs $\mathcal{D}$.

Crossed S-matrices and Fourier matrices for Coxeter groups with automorphism

We study crossed S-matrices for braided G-crossed categories and reduce their computation to a submatrix of the de-equivariantization. We study the more general case of a category containing the symmetric category Rep(A,z) with A a finite cyclic group and z∈A such that z2=1. We give two examples of such categories, which enable us to recover the Fourier matrix associated with the big family of unipotent characters of the dihedral groups with automorphism as well as the Fourier matrix of the big family of unipotent characters of the Ree group of type F42.

CARDIOVASCULAR AND STRENGTH ADAPTATIONS IN CONCURRENT TRAINING IN HYPERTENSIVE WOMEN

ABSTRACT Introduction Physical exercise has been recommended as a non-pharmacological strategy for preventing and controlling hypertension. Objective To verify chronic cardiovascular and muscle strength adaptations in hypertensive women who underwent 12 weeks of concurrent training (CT) in different orders. Methods Twenty hypertensive women were randomly assigned into 2 groups: resistance exercise-endurance group (REE; 56.00 ± 5.20 years; 78.95 ± 8.28 kg; 155.10 ± 5.30 cm; 33.00 ± 5.30 kg.m-2) and endurance-resistance exercise group (ERE; 57.10 ± 13.38 years; 76.56 ± 18.87 kg; 155.50 ± 8.18 cm; 31.41 ± 5.84 kg.m-2). The endurance exercise was composed of 3 sets of 4 exercises, with 8-RM loads with a 90-second break between sets and exercises. The resistance exercise lasted for 25 minutes and was of progressive intensity. Muscle strength (8-RM), systolic and diastolic blood pressure, heart rate, and double product were assessed pre- and post-exercise. Results The ANOVA showed significant increases in strength for all exercises (p <0.0001) regardless of the order of the concurrent training (bench press, p = 0.680; leg press, p = 0.244; seated row, p = 0.668; and leg extension, p = 0.257). No significant differences in systolic (p = 0.074) and diastolic blood pressures (p = 0.064) were observed for different CT conditions. However, significant reductions in systolic (p = 0.0001) and diastolic blood pressures (p = 0.006) and double product (p = 0.006) only occurred in the REE group. Conclusion Endurance training and resistance exercise promote significant muscle strength gains after 12 weeks of training regardless of CT order in hypertensive women. Beneficial cardiovascular responses (SBP, DBP, and RPP) were also observed when endurance training was initiated. Level of evidence I; Therapeutic Studies - Investigating Treatment Outcomes.

Provenance, tectonic setting, and weathering of sediments in Tumaco-1 ST-P well, Tumaco forearc basin, Colombia: Insights from petrography, heavy minerals, X-ray diffraction, and whole-rock chemostratigraphy

A chemostratigraphic evaluation based on major and trace elements (including the REE group), heavy minerals, and whole rock petrographic analysis is applied on 300 samples from the Tumaco-1-ST-P well located in the Tumaco forearc basin, Colombia. The aim of the study is to gain a better understanding of the provenance, tectonic, and paleoweathering conditions of the succession, which contains three formations (Tumaco, Tangareal del Mira, and Cascajal) ranging in age from the late Oligocene to late Pliocene.SiO2 has the highest concentration of all major elements (mean at 52%), followed by Al2O3 (mean at 14.6%), Fe2O3, MgO, and CaO are in the range of 3.2–5.3%, Na2O and K2O oscillate between 1 and 2%, and TiO2, P2O5, MnO, and Cr2O3 are <1%. Out of trace elements, Ba, Sr, V, Cr, Cu, Zn, Ni and Zr are the most abundant; their enrichment is probably due to the marine/deltaic depositional environment conditions. Th, Cs, and Nb have the highest concentrations of all trace elements. In general, concentrations of light rare earth elements are greater than high rare earth elements (LREE > HREE). Both positive and negative Eu anomalies are present in Tumaco and Tangareal del Mira formations, suggesting that rocks have two sources, mafic and felsic; the presence of both is consistent with petrographic and heavy mineral analyses.Paleoweathering indices, such as the chemical index of alteration (CIA), plagioclase index of alteration (PIA), and index of compositional variability (ICV) in the Tumaco-1-ST-P well suggest that the source of these rocks experienced initial stages of weathering compared with Post-Archean Average Australian Shale (PAAS) and Upper Continental Crust (UCC) values, indicating that the Tumaco formation samples have undergone major alteration. The clay mineral assemblage is dominated by the occurrence of illite and illite/smectite mixed layers; when coupled with the CIA index and the Al2O3-CaO-Na2O-K2O (ACNK) plot this indicates post-depositional K-enrichment. The distribution of Al2O3, TiO2, and Zr suggests a limited recycling effect.The presence of first cycle mafic-to-intermediate igneous detritus, together with felsic to intermediate igneous and metamorphic minerals, suggest that the Tumaco forearc basin detrital material was supplied by two locations. One location corresponds to the orogenic island arc system of the Western Cordillera, which is dominated by mafic and intermediate extrusive rocks (basalt and andesite). The other source, which is volumetrically less important, is the Central Cordillera, which comprises intrusive felsic rocks and metamorphic rocks (skarn, marble, and quartz-micaceous schist). This subsidiary source represents a continental arc setting and is observed mainly in the Tumaco Formation.

New Data Relating to the Age, Material Composition, and Geological Structure of the Central Kamchatka Depression (CKD). Part 1. Rock Classification. Age, Petrology, and Isotope Geochemistry

This paper presents new data on the age and isotope geochemistry for plateau effusive rocks sampled from the Central Kamchatka Depression and Nikolka Volcano. We have compared these materials with data on rocks sampled in the Klyuchevskaya Group of Volcanoes, as well as from Shiveluch, Kharchinsky, Zarechnyi, Nachikinsky, and Bakening volcanoes, and from an “NEB-adakite” Pliocene shield volcano in the interfluve between the Ozernaya Kamchatka and the Pravaya Kamchatka rivers. We show that the relatively “advanced,” in the sense of evolution, (mostly alkaline) compositions of rocks sampled from Nachikinsky, Bakening, and Nikolka volcanoes, as well as from the Pliocene shield edifice, have isotope characteristics that are significantly different from those for the Klyuchevskaya Group of Volcanoes. This type of rock is typical of the CKD as a rifting structure. The rocks in the Klyuchevskaya Group of Volcanoes are not typomorphic for this structure and reflect the phase of ordinary orogenic volcanism that has involved a much larger area. The Miocene plateau effusive rocks are only different from the rocks of this group in having a slightly higher potassium alkalinity. Rocks of the rifting type can be recognized, not only by their higher alkalinity, but also by a definite relationship among microcomponents: Ti/V > 0.004, Nb/Y > 0.28, Dy/Yb > 2.00, La/Yb > 6.5, Sm/Yb > 2.4, Lu/Hf < 0.08. Along with the isotope characteristics, these relationships suggest the existence of a common deep-seated asthenospheric mantle reservoir for the parent melts. The area of junction between the Kuril–Kamchatka and the Commander-Islands–Aleutian island arc system is marked by a higher fluid enrichment (the cerium REE group) in melts for rocks of some volcanoes, viz., Shiveluch, Kharchinskii, and Zarechnyi.

The small Ree group $^{2}G_{2}(3^{2n+1})$ and related graph

Let $G$ be a finite group. The main supergraph $\mathcal{S}(G)$ is a graph with vertex set $G$ in which two vertices $x$ and $y$ are adjacent if and only if $o(x) \mid o(y)$ or $o(y)\mid o(x)$. In this paper, we will show that $G\cong ^{2}G_{2}(3^{2n+1})$ if and only if $\mathcal{S}(G)\cong \mathcal{S}(^{2}G_{2}(3^{2n+1}))$. As a main consequence of our result we conclude that Thompson's problem is true for the small Ree group $^{2}G_{2}(3^{2n+1})$.

A new characterization of Ree group $mathbf{{}^2G_2(q)}$ by the order of group and the number of elements with the same order

‎‎In this paper‎, ‎we prove that Ree group ${}^2G_2(q)$‎, ‎where $qpmsqrt{3q}+1$ is a prime number can be uniquely determined by the order of group and the number of elements with the same order‎.

On centres of 3-blocks of the Ree groups [formula omitted

Let G:=G22(q) be the simple Ree group with q=32k+1 and k a positive integer. We show that the centre of the principal block Z(kGe0), where k is an algebraically closed field of characteristic 3, is not isomorphic to the centre of the Brauer corresponding block Z(kNG(P)), where NG(P) is the normaliser in G of a Sylow 3-subgroup.

Groups of Ree type in characteristic 3 acting on polytopes

Every Ree group R( q ) , with q ≠ 3 an odd power of 3, is the automorphism group of an abstract regular polytope, and any such polytope is necessarily a regular polyhedron (a map on a surface). However, an almost simple group G with R( q ) < G ≤ Aut(R( q )) is not a C-group and therefore not the automorphism group of an abstract regular polytope of any rank.