bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptive Finite-time Dynamic Surface Neural Network Control of an Uncertain Robot with Output Constraint and Input Saturation
Authors: Zhang Zhao , Peng Lingxi , Zhao Zhijia 
Published: July 2021

Abstract
In this study, a finite-time dynamic surface neural network control is developed for an uncertain n-link robot subject to input saturation and output constraints. First, a barrier Lyapunov function and a hyperbolic tangent function are applied to solve the system constraints using a dynamic surface control. Subsequently, a radial basis function neural network is utilized to handle system uncertainties. Then, a finite-time filter is employed in the design to achieve the fast convergence and a Nussbaum function is employed to optimize the design process. Finally, the simulation results show that the dynamic tracking error is proved to converging to zero, and the proposed control method is effective and never violates the constraints.
Efficacy of Artesunate-Amodiaquine and Artemether-Lumefantrine for Uncomplicated Plasmodium Falciparum Malaria in Madagascar, 2018
Authors: Dentinger Catherine M. , Rakotomanga Tovonahary Angelo , Rakotondrandriana Antsa , Rakotoarisoa Arinomenjanahary , Rason Marie Ange , Moriarty Leah F. , Steinhardt Laura C. , Kapesa Laurent , Razafindrakoto Jocelyn , Svigel Samaly S. , Lucchi Naomi W. , Udhayakumar Venkatachalam , Halsey Eric S. , Ratsimbasoa C. Arsène 
Published: July 2021

Abstract
Background: Since 2005, artemisinin-based combination therapy (ACT) has been recommended to treat uncomplicated Plasmodium falciparum malaria in Madagascar. Artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) are the first- and second-line treatments, respectively. A therapeutic efficacy study was conducted to assess ACT efficacy and molecular markers of antimalarial resistance.Methods: Children aged six months through 14 years with uncomplicated P. falciparum malaria and a parasitemia of 1,000—100,000 parasites/µl determined by microscopy were enrolled from May—September 2018 in a 28-day in vivo trial using the 2009 World Health Organization protocol for monitoring antimalarial efficacy. Participants from two communes, Ankazomborona (tropical, northwest) and Matanga (equatorial, southeast), were randomly assigned to ASAQ or AL arms. PCR correction was achieved by genotyping seven neutral microsatellites in paired pre- and post-treatment samples. Genotyping assays for molecular markers of resistance in the pfk13, pfcrt, and pfmdr1 genes were conducted.Results: Of 344 patients enrolled, 164/170 (96%) receiving ASAQ and 170/174 (98%) receiving AL completed the study. For ASAQ, the day-28 cumulative PCR-uncorrected efficacy was 100% (95% CI 100–100) and 95% (95% CI 91–100) for Ankazomborona and Matanga, respectively; for AL, it was 99% (95% CI 97–100) in Ankazomborona and 84% (95% CI 76–92) in Matanga. The day-28 cumulative PCR-corrected efficacy for ASAQ was 100% (95% CI 100–100) and 97% (95% CI 94–100%) for Ankazomborona and Matanga, respectively; for AL, it was 100% (95% CI 99–100) in Ankazomborona and 96% (95% CI 91–100) in Matanga. Of 83 successfully sequenced samples for pfk13, no mutations associated with artemisinin resistance were observed. A majority of successfully sequenced samples for pfmdr1 carried either the NFD or NYD haplotypes corresponding to codons 86, 184, and 1246. Of 82 successfully sequenced samples for pfcrt, all were wild type at codons 72–76. Conclusion: PCR-corrected analysis indicated that ASAQ and AL have therapeutic efficacies above the 90% WHO acceptable cut-off. We did not observe any genetic evidence of resistance to artemisinin, consistent with the clinical outcome data. However, the most common pfmdr1 haplotypes were NYD and NFD, previously associated with tolerance to lumefantrine.
Experimental determination of solubility constants of saponite at elevated temperatures in high ionic strength solutions
Authors: Xiong Yongliang 
Published: July 2021

Abstract
Saponite occurs in a wide range of environments from hydrothermal systems on the Earth to surface deposits on Mars. Of practical importance is that Mg-saponite forms when glasses for nuclear waste are altered in Mg-bearing aqueous solutions. In addition, saponite is favorably considered as candidate buffer material for the disposal of high-level nuclear waste and spent nuclear fuel in harsh environments. However, the thermodynamic properties, especially for Mg-saponites, are not well known. Here the author synthesized Mg-saponite (with nitrate cancrinite) following a previously reported procedure and performed solubility experiments at 80 °C to quantify the thermodynamic stability of this tri-octahedral smectite in the presence of nitrate cancrinite. Then, in combination with the equilibrium constant at 80 °C for the dissolution reaction of nitrate cancrinite from the literature, the author determined the solubility constant of saponite at 80 °C based on the solution chemistry for the equilibrium between saponite and nitrate cancrinite, approaching equilibrium from the direction of supersaturation, with an equilibrium constant of –69.24 ± 2.08 (2σ) for dissolution of saponite at 80 °C. Furthermore, the author extrapolated the equilibrium constant at 80 °C to other temperatures (i.e., 50, 60, 70, 90, and 100 °C) using the one-term isocoulombic method. These equilibrium constants are expected to have applications in numerous fields. For instance, according to the extrapolated solubility constant of saponite at 50 and 90 °C, the author calculated the saturation indexes with regard to saponite for the solution chemistry from glass corrosion experiments at 50 and 90 °C from the literature. The results are in close agreement with the experimental data. This example demonstrates that the equilibrium constants determined in this study can be used for reliable modeling of the solution chemistry of glass corrosion experiments.
Hydrothermal troctolite alteration at 300 and 400 °C: Insights from flexible Au-reaction cell batch experimental investigations
Authors: Hansen Christian T. , Lissenberg C. Johan , Kahl Wolf-Achim , Bach Wolfgang 
Published: July 2021

Abstract
Troctolites are increasingly recognized as a common rock found in association with oceanic core complexes. They are similar to komatiite in composition, and hence troctolite alteration may provide insight into H2 production on Early Earth. We investigated the hydrothermal alteration of olivine-rich troctolites in two batch experiments (300 °C, and 400 °C – 40 MPa) by reacting forsteritic olivine and anorthite-rich plagioclase with salt solutions. The alteration process was evaluated based on concomitant fluid samples and solids retrieved upon the termination of the experiments. In both experiments, the initial rock powder was turned into a hard, compact mass through cementation by secondary phases. The heterogeneity of this mass was documented using µ-computed tomography and electron microscopy. Thermodynamic computations were conducted to determine the equilibrium phase assemblages and fluid compositions with increasing reaction turnover.
Mineral zonation developed between the fast-reacting, fluid-dominated top portion of the solids and the more isolated portions at the bottom of the reaction cell. At 300 °C, the total reaction turnover after 1800 h was 77.5%. Serpentinization of olivine controlled the fluid composition after plagioclase had reacted away in the top layers. In contrast, a Ca- and Al-enriched assemblage of xonotlite and chlorite developed alongside unreacted plagioclase at the bottom. The porosity is very low in the top layers but high (around 15%) in the bottom part of the cemented mass. At 400 °C, the reaction turnover was only 51% as olivine was stable after plagioclase had reacted away. Clinopyroxene and andradite ± chlorite had formed in the top layers, whereas xonotlite, grossular, and chlorite had formed at the bottom. The permeability is more uniform and the mineral zonation less pronounced at 400 °C. These mineral zonations developed as a consequence of increased mobility of Ca, Al, Mg, and to a lesser extent of Fe in the experiment, which may be facilitated in the highly permeable granular materials when compared to a compact rock. Steady-state hydrogen concentrations were at least 20 mmol L−1 at 300 °C and &lt;1 mmol L−1 at 400 °C. A lack of magnetite formation at the higher temperature is responsible for the low-H2 yields.
Etching of fission tracks in monazite: Further evidence from optical and focused ion beam scanning electron microscopy
Authors: Jones Sean , Kohn Barry , Gleadow Andy 
Published: July 2021

Abstract
A series of experiments on monazites from Victoria, Australia, is presented to further understand their fission track etching properties. Using a 6 M HCl etchant at 90 °C, SEM images on crystal (100) pinacoid faces reveal well-etched rhombic spontaneous fission track openings. Average rhombic etch pit diameters Dpc and Dpb, parallel to the crystallographic c- and b-axes are 0.81 ± 0.20 µm and 0.73 ± 0.26 µm, respectively. An angular distribution experiment on (100) faces found that spontaneous fission tracks initially etch anisotropically, being preferentially revealed at an azimuth of 90° to the crystallographic c-axis up to ~60 min of etching. As etching continues, however, the distribution becomes progressively more uniform and is essentially isotropic by 90 min. Two experimental methods determined the rate at which the etchant penetrated along the lengths of implanted 252Cf fission tracks. This involved the application of a focused ion beam scanning electron microscope (FIB-SEM) to mill progressively into slightly etched monazite crystals followed by an etch-anneal-etch approach. Results indicate that at least the greater part of the etchable ranges of the latent fission tracks were penetrated by the 6 M HCl etchant within the first few minutes. Continued etching to 5 min indicates that track etching slows down toward the ends of the tracks, but the maximum ranges are estimated to be reached after 5–15 min, which represents the longest time the latent segments of the tracks are exposed to potential annealing at the etchant temperature. Taking into account that implanted 252Cf fission tracks in monazite anneal on average ~4% of their length at 90 °C after 1 h (Jones et al. 2019), suggests that a much shorter duration for exposure to this temperature causes less than ~1% of fission track length reduction during etching.
Gungerite, TlAs5Sb4S13, a new thallium sulfosalt with a complex structure containing covalent As-As bonds
Authors: Kasatkin Anatoly V. , Plášil Jakub , Makovicky Emil , Chukanov Nikita V. , Škoda Radek , Agakhanov Atali A. , Tsyganko Mikhail V. 
Published: July 2021

Abstract
Gungerite, TlAs5Sb4S13, is a new mineral from the Vorontsovskoye gold deposit in Northern Urals. It occurs in limestone breccias composed of calcite and dolomite and cemented by orpiment, pyrite, realgar, stibnite, and minor baryte and quartz. It belongs to the latest phases among sulfosalts (chiefly Tl-As-Sb ones) present in the ore. The empirical formula (based on the sum of all atoms = 23 pfu) is Tl0.99As5.29Sb3.77S12.95. The Raman spectrum exhibits bands corresponding to As-S and Sb-S stretching vibrations, and a band at 263 cm−1 that is assigned to As–As stretching vibrations. Gungerite is bright orange with an orange streak, greasy luster, and perfect cleavage on {010}. It is translucent in thin fragments. The calculated density is 4.173 g/cm3. In reflected light, the mineral is yellowish-white with very weak bireflectance. In crossed polars, it is distinctly anisotropic but anisotropy effects are masked by strong internal reflections of bright orange color. Gungerite is orthorhombic, with the space group Pbcn. Unit-cell parameters determined from the single-crystal X-ray diffraction data are as follows: a = 20.1958(3) Å, b = 11.5258(2) Å, c = 20.1430(2) Å, and V = 4688.74(12) Å3 (Z = 8). The crystal structure consists of doughnut-shaped (As,Sb)-S clusters, which have van der Waals contacts to most of the surroundings, and are connected to them only by sparse cation-sulfur bonds. These clusters are formed by a chelating mirror-symmetrical group, which is “stacked” on, around, and along rods of the TlS9 coordination polyhedra; these rods are oriented parallel to [010]. An individual doughnut-shaped cluster with a central TlS9 polyhedron half-inserted into it contains one As–As bond 2.449 Å long. The polar Tl rods form a chessboard arrangement with occasional stacking errors leading to twinning on (101). The large and complex structure of gungerite shows remote similarities to that of gillulyite and the rod-like structure of lorándite.
Ferrous hydroxychlorides hibbingite [γ-Fe2(OH)3Cl] and parahibbingite [β-Fe2(OH)3Cl] as a concealed sink of Cl and H2O in ultrabasic and granitic systems
Authors: Koděra Peter , Majzlan Juraj , Pollok Kilian , Kiefer Stefan , Šimko František , Scholtzová Eva , Luptáková Jarmila , Cawthorn Grant 
Published: July 2021

Abstract
Ferrous hydroxychlorides are geochemically important but less recognized mineral species due to their extreme sensitivity to oxidation and hydration in contact with air {typically they convert to akaganéite [Fe3+(O,OH,Cl)]}. Only the γ-form was previously known as the orthorhombic mineral hibbingite, associated with altered mafic intrusive rocks. In this study, we describe the β-polymorph of Fe2(OH)3Cl as a new mineral parahibbingite that was found in pyroxenite from the Karee platinum mine in the Bushveld Complex, South Africa. The two minerals were distinguished by a combination of Raman spectroscopy and FIB-SEM-TEM analytical techniques (TEM-EDX and TEM-SAED). They can be easily recognized by their distinct Raman spectra. Parahibbingite has two very strong vibration bands at ~3550 and 3560 cm–1, accompanied by much weaker bands at ~124 and 160 cm−1, while the Raman spectrum of hibbingite has a sharp, strong band at 3450 cm−1 and two moderate bands at 199 and 385 cm−1.
Parahibbingite was found as fine-grained reaction rims at the contact of orthopyroxene phenocrysts and talc inside a drill core. It has a trigonal space group [R3m, a = 6.94(5) Å; c = 14.5(2) Å], with an empirical formula (Fe1.982+Mn0.012+Ca0.01)(OH)3.08Cl0.92. The origin of this mineral in the Bushveld Complex is most likely related to a late hydrothermal alteration of pyroxenite. Hibbingite forms as an abundant daughter mineral hosted by fluid inclusions and salt melt inclusions in hydrothermal quartz associated with granitic systems during cooling under reducing conditions. Such inclusions are common in Au-porphyry mineralization worldwide, such as the Biely Vrch (Slovakia) deposit studied in detail in this work. The lattice parameters obtained by TEM-SAED are a = 6.30 Å, b = 7.12 Å, and c = 9.89 Å.
Hibbingite was recognized as the only phase that carries “water” (as a hydroxyl group) in otherwise water-free, salt melt inclusions. Furthermore, both hibbingite and parahibbingite should be considered as reservoirs for Cl and H2O in large volumes of altered basic and ultrabasic rocks. They can transport volatiles to shallow levels of subduction zones. Alternatively, their dissolution can fuel remobilization, transport, and deposition of sulfidic ores in saline fluids. Their detection, however, is difficult because of their sensitivity to oxidizing atmospheres. For example, in natural outcrops exposed to air, they may vanish, thus distorting estimates of their abundance and role in many processes that involve mineral-derived volatiles.
Hydrothermal mineralization of celadonite: Hybridized fluid–basalt interaction in Janggi, Korea
Authors: Park Jongkyu , Lim Hoseong , Myeong Bora , Jang Yun-Deuk 
Published: July 2021

Abstract
The origin of celadonite still remains enigmatic and fragmentary. Exceptional celadonite mineralization was discovered in the Miocene lacustrine Janggi Basin in the southeastern Korean Peninsula. This Janggi celadonite is a greenish, earthy/vitreous material filling east-west trending fault zones in basaltic flows. The scale of the celadonite body is up to a meter thick and laterally extends ~10 m. These occurrences are markedly in contrast with celadonite as vesicle-filling or mineral-replacing types in the literature. The Janggi celadonite allows exploring the puzzling genesis of celadonite and comparing its characteristics with global cases for a better understanding of celadonite formation.
X-ray diffraction and microprobe analyses demonstrate that the Janggi celadonite ranges from ferroceladonite through celadonite to ferroaluminoceladonite and is mixed with opal at a ratio of up to ~3:7. Detailed fieldwork and whole-rock major, trace, and oxygen isotope analyses indicate that celadonite is formed in an open system at ~120 °C by the interaction of hybridized fluid (a mixture of &lt;55% magmatic and &gt;45% other origins) and basalts during the physicochemical fault brecciation of the host rock. The cations needed for celadonite formation were supplied from the smectitization/zeolitization of rhyolitic mesostasis (for Al and part of K) and pyroxene microlites (for Fe and Mg) in the basaltic breccias during the associated oxidation of micro-nanoparticles by circulating fluids (for most of K).
A comparison of the Janggi celadonite with global cases highlights that celadonite genesis is neither limited to the seawater alteration of basalt nor do hosts and reactive fluids control celadonite compositions. A contextualized perspective on celadonite genesis alludes that a potassic alteration of rock that is rich in ferromagnesian components in a shallow crustal environment (&lt;~200 MPa at &lt;~450 °C) produces celadonite. Because of the relative availability of the necessary components for celadonite precipitation, our model predicts celadonite mineralization in many volcanic environments, where magmatic fluid and particle size reduction could contribute. These insights emphasize celadonite’s potential applications for tracing geothermal history.
Impact of fluorine on the thermal stability of phlogopite
Authors: Sun Jiaqi , Yang Yan , Ingrin Jannick , Wang Zhongping , Xia Qunke 
Published: July 2021

Abstract
Knowledge of volatile cycling is vital to understanding the evolution of the planet and the life it supports. Although it has been gradually accepted that the mantle is a vast storehouse of H2O and other volatiles, the impact of coexisting volatiles on the thermal stabilities of OH and the lattice of the host mineral is still poorly understood. Phlogopite is one of the few hydrous minerals capable of carrying both water and halogens into the mantle. Previous observations from both experiments and textural relationships in natural samples have indicated that F-rich phlogopite can be stable under ultrahigh-temperature conditions. Here, the impact of F on the thermal stability of phlogopite was investigated via XRD, Raman, and IR spectroscopy from room temperature to 1000 to 1200 °C. Based on the experimental results from F-poor and F-rich natural phlogopites, we show that about 4 wt% F can increase the breakdown temperature of phlogopite by 100 °C under ambient pressure. The impact mechanism mainly involves preventing OH and lattice softening at high temperatures. This study reveals the links between F and the behavior of OH and phlogopite lattice, which is important for constraining volatile cycling, as well as the role of F in the physical and chemical properties of the upper mantle.
Protocaseyite, a new decavanadate mineral containing a [Al4(OH)6(H2O)12]6+ linear tetramer, a novel isopolycation
Authors: Kampf Anthony R. , Cooper Mark A. , Hughes John M. , Ma Chi , Casey William H. , Hawthorne Frank C. , Marty Joe 
Published: July 2021

Abstract
Protocaseyite, [Al4(OH)6(H2O)12][V10O28]·8H2O, is a new mineral (IMA2020-090) occurring in low-temperature, post-mining, secondary mineral assemblages at the Burro mine, Slick Rock district, San Miguel County, Colorado, U.S.A. Crystals of protocaseyite are saffron-yellow, thick blades, with pale orange-yellow streak, vitreous luster, brittle tenacity, curved fracture, two very good cleavages, a Mohs hardness of 2, and a density of 2.45(2) g/cm3. The optical properties of protocaseyite could be only partly determined: biaxial with α = 1.755(5), β &lt; 1.80, γ &gt; 1.80 (white light); pleochroic with X and Y yellow, Z orange (X ≈ Y &lt; Z). Electron-probe microanalysis and crystal-structure solution and refinement provided the empirical formula [(Al3.89Mg0.11Ca0.02)Σ4.02(OH)6(H2O)12][H0.06V10O28]·8H2O. Protocaseyite is triclinic, P1, a = 9.435(2), b = 10.742(3), c = 11.205(3) Å, α = 75.395(7), β = 71.057(10), γ = 81.286(6)°, V = 1036.4(5) Å3, and Z = 1. The crystal structure (R1 = 0.026 for 4032 Io&gt;2 σI reflections) contains both the [V10O28]6− decavanadate polyoxoanion and a novel [Al4(OH)6(H2O)12]6+ polyoxocation.
Zolenskyite, FeCr2S4, a new sulfide mineral from the Indarch meteorite
Authors: Ma Chi , Rubin Alan E. 
Published: July 2021

Abstract
Zolenskyite (IMA 2020-070), FeCr2S4, is a new sulfide mineral that occurs within troilite, with clinoenstatite and tridymite, in the matrix of the Indarch meteorite, an EH4 enstatite chondrite. The mean chemical composition of zolenskyite determined by electron probe microanalysis, is (wt%) S 43.85, Cr 35.53, Fe 18.94, Mn 0.68, Ca 0.13, total 99.13, yielding an empirical formula of Fe0.99Mn0.04Ca0.01Cr1.99S3.98. The ideal formula is FeCr2S4. Electron backscatter diffraction shows that zolenskyite has the C2/m CrNb2Se4-Cr3S4-type structure of synthetic FeCr2S4, which has a = 12.84(1) Å, b = 3.44(1) Å, c = 5.94(1) Å, β = 117(1)°, V = 234(6) Å3, and Z = 2. The calculated density using the measured composition is 4.09 g/cm3. Zolenskyite is a monoclinic polymorph of daubréelite. It may be a high-pressure phase, formed from daubréelite at high pressures (several gigapascals) and moderate temperatures in highly shocked regions of the EH parent asteroid before becoming incorporated into Indarch via impact mixing. Zolenskyite survived moderate annealing of the Indarch whole-rock. The new mineral is named in honor of Michael E. Zolensky, an esteemed cosmochemist and mineralo-gist at NASA’s Johnson Space Center, for his contributions to research on extraterrestrial materials, including enstatite chondrites.
Mediación digital parental. ¿Es necesaria una educación digital en la primera infancia?
Authors: Grané I Oró Mariona 
Published: July 2021

Familias y educadores se debaten entre la visión de oportunidad educativa y el pánico de las consecuencias del uso de tecnología por parte de los más pequeños. Las incertidumbres son diversas y no existen demasiadas investigaciones que muestren como madres y padres integran las tecnologías en casa y como gestionan la relación de sus hijos con las pantallas. La situación pone de manifiesto que más allá de preocuparse es necesario ocuparse.
Este estudio se interroga sobre la necesidad de pensar y diseñar acciones de acompañamiento, educativas y contextualizadas del uso de las tecnologías digitales durante la primera infancia. El articulo presenta una revisión sistematizada de los estudios realizados en la línea de crianza digital (digital parenting) que atienden específicamente a niños y niñas menores de 6 años.
Con el objetivo de encontrar respuesta a la influencia familiar en el uso de medios y sus repercusiones en el desarrollo, comprender el alcance de la investigación en crianza digital, analizar las necesidades de profundización y los vacíos de conocimiento sobre la cuestión.