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Well-defined Mg(OH)2 (brucite) hexagonal platy particles with the lateral size of 80 nm were prepared by precipitation from an aqueous solution of magnesium chloride using a flow reactor with contr...

Seven landslides among the 110 landslides on the northeastern margin of the Tibetan Plateau in China were selected to analyze the structural development processes within the shear zones. In addition, the platy clay mineral content and mineralogical composition of the shear zone were also investigated. The samples obtained from the vertical profiles were quantitatively studied from top to bottom with respect to their material composition, pore structure, and water properties to understand the changes in the cementation and frictional properties of the shear zone. The results indicate that the structure is progressively modified by fractures, cleavage, and plasticization. Even though there is no sliding surface liquefaction, clayey particles are observed to exhibit slipping and rearrangement. The illite–montmorillonite mixed-mineral layer accumulates near sliding surface in the core zone, and the platy clay minerals are arranged along shearing direction for long shear displacement.

A classification of heat exchange apparatuses with fluidized bed consisting of granular material is proposed. A survey of the most characteristic designs of the different types of heat exchange instruments, such as shell-and-tube, coil-type, tube-in-tube (double-tube), platy, column-type, capacitive, etc. structures, is presented.

The formation stages of hybrid halide perovskite MAPbI3 when methylammonium-based reactive polyiodide melts (RPMs) are reacted with PbI2 platy crystals at room temperature are studied. The local dissolution of the lead-containing precursor and subsequent crystallization of homogeneously formed nuclei is found to be the major perovskite crystallization mechanism under these conditions. The iodine content in the reaction mixture acts as a very important parameter for controlling the rate and degree of PbI2 conversion, which can be used to develop new preparation techniques to produce light-harvesting layers for solar cells with a tunable coating morphology.

Hydrosilicates of the kaolinite group (Al2Si2O5(OH)4 · nH2O) with spherical, nanotubular, and platy particle shapes are synthesized in hydrothermal conditions. The morphology and size of the particles, as well as the porous-textural characteristics, are studied by scanning electron microscopy (SEM) and low-temperature nitrogen absorption. The sorption capacity of the samples relative to the cationic and anionic dyes is investigated on the example of methylene blue and carmoisine. A comparative analysis is conducted for the characteristics of synthetic aluminosilicates and their natural analogs: nanotubular halloysite and kaolinite with platy particles. It is shown that characteristics such as porosity (diameter and volume of pores) and the specific surface area (from 11 m2/g for platy to 470 m2/g for spherical particles) can differ among kaolinite subgroup aluminosilicates having a different morphology. It is shown that the synthetic aluminosilicate with spherical particles (dav = 300 nm) is an effective universal sorbent of differently charged ions from aqueous solutions and its characteristics are better than for structural analogs and synthetic aluminosilicates of a different morphology.

Coral platy fish has a unique reproduction due to ovoviviparous (live-bearer) reproduction. The large scale production of coral platy fish has several constraints due to the inconsistent seed birth period, which causes variations in the fry size. This makes it difficult for ornamental fish cultivators for production process efficiency and market criteria fulfillment that demands size uniformity. This study aimed to synchronize the broodstock birth period of coral platy fish by testing the hormone oxytocin and prostaglandin-2 α (PGF2α) through immersion methods with different durations. This study used a factorial randomized design with 21 treatments and 3 replications for each hormone type. The PGF2α hormone doses used were 0; 0.01; 0.1 and 1 mL/L, while the oxytocin hormone doses used were 0; 0.1; 0.2; 0.4 mL/L with immersion duration of 4, 8, and 12 hours, respectively. The results showed that the treatment dose of 1 mL/LPGF2α with 12 hour duration had a significant effect (p 0.05). Keywords:mass induction, oxytocin, prostaglandin-e2 α (PGF2α), mass birth, livebearer ABSTRAK Ikan plati koral memiliki reproduksi yang unik karena bereproduksi secara ovovivipar (livebearer). Produksi ikan plati koral dalam skala besar dihadapkan kendala akibat waktu kelahiran anak yang tidak serentak yang menyebabkan keberagaman ukuran anak ikan plati koral. Hal ini menyulitkan para pembudidaya ikan hias untuk efisiensi proses produksi dan memenuhi kriteria pasar yang menuntut keseragaman ukuran. Penelitian ini bertujuan untuk menyeragamkan waktu kelahiran anak induk ikan plati koral dengan uji coba pemberian hormon oksitosin dan prostaglandin-2 α (PGF2α) melalui metode perendaman dengan durasi waktu yang berbeda. Penelitian ini menggunakan rancangan acak faktorial dengan 21 perlakuan dengan 3 kali ulangan untuk masing-masing jenis hormon. Dosis hormon PGF2α yang diuji adalah 0; 0,01; 0,1 dan 1 mL/L, sedangkan dosis hormon oksitosin yang digunakan adalah 0; 0.1; 0.2; 0.4 mL/L dengan masing-masing lama perendaman 4, 8, dan 12 jam. Hasil yang diperoleh menunjukkan bahwa perlakuan dosis 1 mL/L PGF2α dengan lama waktu perendaman 12 jam memberikan pengaruh yang nyata (p 0.05). Kata kunci: induksi massal, Oksitosin, prostaglandin-2 α (PGF2α), kelahiran masal, livebearer

Analogue sinter tablets were produced at temperatures between 1250°C and 1320°C, with a range of hold times and cooling rates. Platy silico-ferrite of calcium and aluminum (SFCA) morphology was identified in samples produced at 1250°C using reflected light microscopy; however, quantitative x-ray diffraction (XRD) identified the presence of the SFCA phase, with no SFCA-I detected. This proves that the platy SFCA morphology common in analysis by reflected light microscopy cannot be attributed to the SFCA-I mineral without further analysis. Micro-XRD and electron probe micro-analysis (EPMA) were carried out on an area of platy SFCA confirming this result. The sinter analogue tablets were reduced in a 30% CO, 70% N2 gas mixture at 900°C in a tube furnace thermo-gravimetric analyzer. The degree of reduction of the tablets in this study was found to be controlled by the porosity of the samples, rather than by the morphology or mineralogy of the bonding phase.

The performance of particulate photocatalysts for solar H2 production highly depends on the unique morphology and tailored shape. Herein, we successfully fabricated a highly crystalline BaTaO2N cry...

The present study considered the problem of halloysite nanoscroll synthesis by energy modeling of the formation of chrysotile and halloysite particles. The main aim of the study was to reveal an energy preference between scrolled and platy morphologies of the particles. Both hydrosilicates possess the ability to scroll spontaneously but relatively facile hydrothermal synthesis of the nanoscrolls is available only to the former, whereas halloysite forms mainly plates under the same conditions. This issue was investigated by a phenomenological energy model, taking into account: (1) strain energy due to the size difference between metal oxide and silica sheets; (2) surface-energy difference on the opposite sides of the layer; and (3) adhesion energy. Calculations showed that the halloysite layer had a significant scrolling potential due to the first energy component, but the surface-energy difference acted in the opposite direction and tried to unbend the layer. In contrast, these two actions were co-directional in chrysotile layers. In both cases, the formation of multi-layered plates became more energy favorable when the specific surface energy of the edges decreased. In the range 0.5–3 J/m2 for the specific surface energy, only halloysite layers showed an energy preference for platy particles over nanoscrolls, especially at small layer sizes. Certain processes, such as hydration, could reduce the corresponding specific surface energy value and, as a result, could stabilize the platy morphology of halloysite at the earliest stages of particle growth under hydrothermal conditions.

This study was conducted to investigate the effects of sintering conditions on the phase composition, microstructure, and physico-mechanical properties of the bauxite-based low-cement refractory castables. For this purpose, the specimens were sintered at various temperatures (1350-1450 °C) and heating rates (3-10 °C/min). Results showed that the sintering conditions have a remarkable effect on the physico-mechanical properties of the refractory castables. The mechanical strength was considerably increased by increasing the heating rate from 3 to 10 °C/min which was attributed to lower amounts of porosity and higher amount of the platy crystals of CA6 phase. The lower porosity of the specimens sintered at lower temperature with 10 °C/min of heating rate also resulted in the higher mechanical strength. The results obtained in this study showed a negative linear relationship between the cold crushing strength and porosity of the specimens with a high degree of measurement conformity.

The adsorption and retention of phosphates in soil systems is of wide environmental importance, and understanding the surface chemistry of halloysite (a common soil clay mineral) is also of prime importance in many emerging technological applications of halloysite nanotubes (HNTs). The adsorption of phosphate anions on tubular halloysite (7 Å) has been studied to gain a greater understanding of the mechanism and kinetics of adsorption on the surface of HNTs. Two well-characterized tubular halloysites with differing morphologies have been studied: one polygonal prismatic and one cylindrical, where the cylindrical form has a greater surface area and shorter tube length. Greater phosphate adsorption of up to 42 μmol g–1 is observed on the cylindrical halloysite when compared to the polygonal prismatic sample, where adsorption reached a maximum of just 15 μmol g–1 compared to a value for platy kaolinite (KGa-2) of 8 μmol g–1. Phosphate adsorption shows strong pH dependence, and the differences in phosphate sorption between the prismatic and cylindrical morphologies suggest that phosphate absorption does not occur at the same pH-dependent alumina edge sites and that the lumen may have a greater influence on uptake for the cylindrical form.

Shear wave velocity (Vs) anisotropy of kaolinite mixed with sodium chloride (NaCl) and organic polymer (polyethylene oxide, xanthan gum, and chitosan) solutions was investigated using a custom-made floating wall consolidometer-type bender element testing system. The addition of salt and polymers influenced the microfabric anisoopy of platy kaolinite particles, thus resulted in the increment or decrement in the Vs anisotropy. The Vs of kaolinite in all three orthogonal directions increased as the NaCl concentration increased; however, the Vs anisotropy decreased. PEO and chitosan increased the Vs of kaolinite, while xanthan gum exhibited counter-effects. Vs anisotropy (Vs−hh/Vs−vh and Vs−hv/Vs−vh) of polymer amended kaolinite was found to decrease. In addition, both salt- and polymer-modified kaolinite did not show Vs cross-anisotropy.

The Duotoushan deposit is an important Fe–Cu deposit in the Aqishan–Yamansu metallogenic belt of eastern Tianshan, NW China. Magnetite occurs in two main habits which are common in many Fe–Cu deposits, i.e. platy (TD1 Mag) and granular magnetite (TD2 Mag) have been identified at Duotoushan. Platy magnetite shows two different zones (bright and dark) based on the observations by scanning electron microscopy. The bright part (TD1-L) is the main part of TD1 magnetite and lacks inclusions. The dark part (TD1-D) is very porous and has abundant tiny silicate inclusions. Granular magnetite is usually anhedral with obvious oscillatory zoning in back-scattered electron images. In general, the dark zones of magnetite are characterised by greater Si, Ca, Al and lesser Fe contents than the bright zones. In situ X-ray diffraction (XRD) analysis shows that the lattice parameter of TD1 magnetite is approximately equal to that of standard magnetite and slightly higher than that of TD2 magnetite, indicating that some cations with ionic radii smaller than those of Fe2+ or Fe3+ entered the magnetite lattice by simple or coupled substitution mechanisms in TD2 magnetite.The results in the present study show that the effects of temperature and $f_{{\rm O}_ 2}$ on platy magnetite are very limited and the changing fluid composition might be the major controlling factor for the formation of Duotoushan platy magnetite. Although the possibility that mushketovite transformed from hematite cannot be excluded entirely, evidence from in situ XRD data, pore-volume ratio calculation and the growth habit of intergrown minerals indicates that platy magnetite (TD1) coexisting with amphibole was more likely to have been precipitated originally from hydrothermal fluid. This was then affected by changes in the fluid composition which consequently led to dissolution of primary magnetite (TD1-L) and re-precipitation of TD1-D magnetite (with abundant porosity and mineral inclusions). Meanwhile, granular magnetite (TD2) with oscillatory zoning, and coexisting with epidote and quartz, was precipitated from fluid with periodic variation in temperature. These oscillatory zones are characterised by bands enriched in Si, Al and Ca alternating with bands depleted in these elements. The present investigation revealed a complex evolutionary process for magnetite formation in the Duotoushan deposit. The importance of combined investigation of texture and compositional characterisation of magnetite for study of the ore genesis and evolution of Fe–Cu deposits is highlighted.

The Precambrian Eastern Ghats Group of rocks consisting of a series of regionally metamorphosed rocks such as khondalite, charnockite, calc-granulite and quartzite hosts several pockets to lensoidal Mn-ores in Odisha, Eastern India. The Mn-minerals identified in these deposits are Mn-silicates and lower Mn-oxides with Mn-oxyhydroxides. Lithiophorite, an aluminous Mn-oxyhydroxide mineral, is conspicuous with other secondary Mn-phases. It generally occurs in two habits, such as cryptocrystalline/crystalline aggregates either as vug fillings or as replacement of other minerals like cryptomelane/romanechite/goethite/graphite. Two morphological types of lithiophorite viz. globular and platy were examined in detail by optical and electron microscopy. The electron probe micro-analyses (EPMA) of these two morpho-types reveal the cryptocrystalline (globular) type to be rich in both CoO and NiO, while the platy crystalline type is preferentially enriched in NiO and depleted in CoO. Compositional map for both the types also supports such selective entrapment. Binary plots of electron probe data for MnO2 and Al2O3 versus CoO and NiO in the globular type show strong positive relation confirming to their presence in adsorbed state. In contrast, the NiO in platy type show strong positive relation with Al2O3 only indicating desorption of Co and a part of Mn from the structure during crystallisation and its subsequent diadochic substitution in the alumina lattice.

Onychites aff. barbatus is excessively rare in the Polish Jura. This paper describes a recent find from the basal middle Oxfordian. The specimen is preserved in a manner typical for other finds of this kind in platy limestones, i.e., as compressed and flattened imprints with remnants of carbonized organic matter. Excellent preservation of the surfaces enables a precise reconstruction of the original structure. Accordingly, I hypothesize on the attachment to soft parts and the function of the belemnite onychites. The high diversity of known onychites, especially from Europe (NW Tethys), indicates that they served a variety of purposes.

The morphology of hydroxyapatite crystals formed in hydrothermal reaction of calcium EDTA complex with KH2PO4 at 120 °C depends on the pH value of the reaction medium. Bone-like platy microcrystals were prepared at pH 6, while at higher pH values rod-like species were obtained.

Rotating drums are widely used in industry for powder mixing, milling, coating and drying processes. Segregation is inevitable when using a rotating drum to mix granules differing in size, density or shape. Size segregation in rotating drums has received comprehensive studies over the past decades, but most of the studies concentrate on spherical particles. Particle shape, as one of the important particle properties, could affect size-induced segregation significantly. However, such an effect is still poorly understood. In this work, DEM is employed to study the radial segregation of binary-sized ellipsoidal particles in a rotating drum. The segregation patterns for both spheres and ellipsoids are presented and compared. The effects of aspect ratio, size ratio and rotating speed on the extent of segregation are investigated. Generally, large particles tend to segregate to the periphery of the bed, whereas small ones are accumulated in the core section. As particle aspect ratio deviates from unity, i.e. elongated or platy shape-type, the extent of segregation is reduced. Small ellipsoidal particles tend to be entrained by large ellipsoids causing less segregation. The decrease of size ratio of small to large particles does not necessarily lead to a higher segregation extent. The results also show that in rolling or cascading regimes, increasing the rotating speed can reduce the extent of segregation for both spheres and ellipsoids. The studies also indicate that the initial states of mixtures do not affect the final segregation patterns.

The Arrivo®6EC is an insecticide used to control pests, such as ants and ticks. Its active ingredient is cypermethrin, in this case as a polluting agent that emulsifies in water. This agent presents an environmental risk of high toxicity in fish and aquatic organisms. The objective of this is to evaluate the toxicity on platy fish Xiphophorus maculatus when exposed to cypermethrin. Given that Arrivo®6EC is commonly used in Panama, the study was carried out to analyze the affectations caused in freshwater fish. The tests were duplicated for the cypermethrin levels, which were 1 mg / L and 2.5 mg / L. The fish have an average size and weight of 28.5 cm and 0.33 g respectively, and an age of approximately two to three weeks. In the observations made in the different hours, the symptoms in the fish varied from: little ability to swim, erratic movement, movement only with stimulation, dyspnea, upright and spiral swimming, and death. After dying, the most outstanding aspects were: degeneration of superficial tissues and tails, hyperemic lesions, hemorrhagic signs and pigmentation on the body surface. It was found that even at concentrations of 1 mg / L there is high mortality rate of this lethal contaminant for the species X. maculatus. It is recommended to start with content values ​​below 1 mg / L, to obtain better results, and considering the age, size and weight, since this depends on the enieria Civil, toxicological effects, El Arrivo®6EC es un insecticida utilizado para el control de plagas, como hormigas y garrapatas. Su ingrediente activo es la cipermetrina, en este caso como agente contaminante que emulsifica en el agua. Este ingrediente presenta un riesgo ambiental de alta toxicidad en peces y organismos acuáticos. El objetivo de este experimento fue evaluar la toxicidad de peces platy Xiphophorusmaculatus al ser expuestos a la cipermetrina. Dado que el Arrivo®6EC es utilizado comúnmente en Panamá, se realizó este estudio para comprobar las afectaciones causadas en los peces platys. Las pruebas se realizaron de manera duplicada para dos concentraciones de cipermetrina, las cuales fueron 1 mg/L y 2.5 mg/L.Los peces presentaban un tamaño y peso promedio de 28.5 cm y 0.33g respectivamente, y una edad de dos a tres semanas aproximadamente.En las observaciones realizadas en las diferentes horas, los síntomas en los peces variaban desde: poca habilidad para nadar, movimiento errático, movimiento solo con estimulación, disnea, natación erguida y en espiral, hasta la muerte. Después de morir, los aspectos más notados fueron: degeneración de tejidos superficiales y colas, lesiones hiperémicas, signos hemorrágicos y pigmentación en la superficie corporal. Se comprobó que incluso en concentraciones de 1 mg/L resultan en una alta tasa de mortalidad de este contaminante letal para la especie Xiphophorus maculatus. Se recomienda iniciar con valores de concentraciones por debajo de 1 mg/L, para obtener mejores resultados, y tomándose en cuenta la edad, el tamaño y el peso, pues de esto depende los efectos toxicológicos.

Platy kaolin can provide significant value in the coating of paper and paperboard. It can be used in multiple applications and can provide benefits such as titanium dioxide (TiO2) extension, smoothness improvement, improved print gloss or ink set rates, calendering intensity reduction, and improved barrier properties. It is not a pigment that can be simply substituted for traditional hydrous kaolin without some adjustment to the coating formulation. These adjustments can be as simple as reducing solids, but may require binder changes as well. The coater setup may need to be adjusted because of the unique rheological behaviors these pigments exhibit. The unique rheological characteristics of platy kaolin are explored here. Measurements of the water retention of platy kaolin containing coatings confirm that water retention is not reduced in comparison to more blocky kaolin pigments, despite the lower coating solids at which they need to be run. This means that the rheological characteristics are the most important in understanding the runnability. An extensive analysis reveals some unique behaviors that need to be understood when utilizing these materials. Viscoelastic measurements indicate that, for this binder system, Tan δ is mainly a function of solids. This may explain how weeping is initiated on a blade coater. The degree of shear thinning behaviors is investigated using the Ostwald de-Waele power law. The immobilization point was determined using the Dougherty-Krieger equation and related to the work of Weeks at the University of Maine on blade coater runnability. An indirect measure of particle shape and size synergy is also demonstrated using the Dougherty- Krieger equation parameters.

SiO2 coated platy TiO2 (S-pTi) was prepared as a noble UV/IR(Ultraviolet/Infrared)-shielding material by a modified Stober method. S-pTi consists of a dense and uniform SiO2 shell onto platy TiO2 (pTi) core, and the thickness of SiO2 shell layer was coated about 8–20 nm by tuning SiO2 coating amount. The zeta-potential of S-pTi was decreased from −12 to −32 mV with increasing amounts of coated SiO2, indicating the improvement of dispersibility between the particles. The UV-shielding ability of S-pTi was improved by enhancing UV absorption of the SiO2 coating layer onto pTi and thus the photocatalytic activity was suppressed effectively. Compared to nanosized TiO2(nTi), S-pTi showed higher UV absorption at the shorter wavelength and exhibited higher IR reflectance because of high reflective index and the crystal shape and size of pTi to reflect the IR effectively under its wide shielding area. These results can contribute to the prevention of harmful UV and the maintenance of a cool environment from IR heat source as noble UV/IR-shielding materials on the skin.

1 Tribological properties of the brake friction material including straight phenolic resin with different molecular weighs (Mw), and potassium titanate with different morphologies (platelet and whisker), were investigated. Results showed that the friction coefficient and wear rate were strongly affected by the contact plateaus on the friction material surface. At low temperatures, before the thermal decomposition of the resin, the friction materials with high-Mw resin and platy potassium titanate yielded improved friction and wear resistance characteristics, which were attributed to the large plateaus on the sliding surface. On the other hand, at temperatures higher than the thermal decomposition temperature, the friction materials comprising high-Mw resin and potassium titanate whisker yielded higher friction levels and lower wear rates. These changes were supported by increased activation energies and the facilitation of secondary contact plateaus by potassium titanate reinforcements. The presence of the contact plateaus also affected the size distribution of the wear debris. At temperatures lower than the thermal decomposition temperature, high-Mw resin produced larger wear debris, whereas friction materials with potassium titanate whisker produced larger wear particles at higher temperatures. These findings suggest that it is possible to tailor brake emissions by considering the synergistic effects of the constituent ingredients.

The platy limestone deposit of Vallecillo, located in north-eastern Mexico, offers a wide variety of invertebrate and vertebrate species dated to the latest Cenomanian-middle Turonian (Late Cretaceous). The deposit is known to contain well preserved fossils, e.g., fishes, in which the bones are recrystallized to calcite but soft tissue is also preserved. The fish assemblage is dominated by pelagic fast swimmers but also includes the common pycnodont Nursallia gutturosum, a discus-like and compressed fish that was likely well-suited for maneuverability. A review of 90 individuals of this taxon indicates the presence of different ontogenetic stages, from early young to old age. The size range distribution of individuals also suggests intermittent migration out of the Vallecillo area. The taphonomical decay analysis of N. gutturosum allows for a differentiation of five preservational stages. The presence of frequently complete and articulated specimens suggests a deep dwelling life style, without carcass flotation to the surface.

Perovskite-type NaTaO3 is best known as a semiconductor photocatalyst that splits water under ultraviolet (UV) light irradiation. Here, we report the flux growth of millimeter-sized, platy NaTaO3 c...

Large kaolin deposits developed by weathering on Precambrian granitic rocks have been discovered in the Caluquembe area, Huila province, Angola. To determine accuracy of analysis and to evaluate the kaolinite grade, a full-profile Rietveld refinement by X-ray Powder Diffraction (XRPD) and Thermal Gravimetric Analysis (TGA) was used. Caluquembe kaolin is composed mainly of kaolinite (44–93 wt.%), quartz (0–23 wt.%), and feldspar (4–14 wt.%). The Aparicio-Galan-Ferrell index (AGFI), calculated by XRPD profile refinement, indicates low- and medium-defect kaolinite. Kaolinite particles show a platy habit and they stack together forming ‘booklets’ or radial aggregates; they also occur as small anhedral particles in a finer-grained mass. Muscovite-kaolinite intergrowths have also been found. Whole-rock chemical analysis included major, trace, and Rare Earth Elements (REE). Chondrite-normalized REE patterns show the same tendency for all samples, with a significant enrichment in Light Rare Earth Elements (LREE). Mineralogical and compositional features of the Caluquembe kaolin indicate that it is a suitable material for the manufacture of structural products, such as bricks, paving stones, and roofing tiles. In addition, the significant REE contents of the Caluquembe kaolin can be considered as a potential future target of mining exploration.

SiO2 greatly influences the formation of acicular calcium ferrite (ACF), which is the main binder phase in sinter, but the mechanism of its influence is not yet clear. Experiments were carried out under air at 1200 °C with different amounts of SiO2 mixed with Fe2O3 and Ca(OH)2. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and three-dimensional (3D) reconstruction were used to characterize the phase and morphological changes of the sintered samples. The results show that SiO2 can form silicon-ferrite of calcium (SFC), which is beneficial to the formation of ACF in sinter. The SFC content first increased and then decreased with the increasing SiO2 content. The sintered sample contained the highest contents of SFC and ACF when w(SiO2) was 3 to 4 pct. The morphological changes in calcium ferrite observed with the increasing SiO2 content followed a sequence of massive → platy → acicular; both platy calcium ferrite and ACF were the longest in one direction in their 3D morphology. The inclusion of Si4+ in calcium ferrite crystals changes the crystal growth habit from having no obvious orientation to having a preferential orientation along the (040) or (320) surfaces, as determined by the first-principles calculations and XRD analysis of block samples. Viscosity was the main environmental factor influencing the size of ACF in samples with sufficient liquid phase.

Mixtures of a fine sand with platy shell fragments have been tested under drained monotonic and high-cyclic loading. The content (0 to 40 %) and the size of the platy shell particles in the mixtures were varied. Comparative tests have been also performed on a mixture containing 40 % coarse sand and gravel particles instead of the shells. In the cyclic tests different stress amplitudes, initial relative densities and average stresses have been tested on the various mixtures. The strain accumulation rates were found to increase with growing content of shell particles. This can be primarily attributed to the more well-graded grain size distribution curves of the sand-shell mixtures. Particle breakage effects were almost absent in the cyclic tests as demonstrated by sieve analysis. Dependencies between the parameters of a high-cycle accumulation (HCA) model and the content of shell particles are analyzed. Amongst others, an extraordinary low dependence of the strain accumulation rate on strain amplitude (parameter C ampl 1 ) has been observed for larger amounts of shell particles in the mixtures.

Highly transparent LaGdZr2O7 ceramics were fabricated by solid reactive sintering using the ball-milling mixed raw powder, and the transparency of samples can be significantly enhanced by optimizing the ball-to-powder weight ratio. The ratio effects on the evolution of morphology and particle size distribution of mixed powder, as well as the relative density and the in-line transmittance of obtained LaGdZr2O7 ceramics were investigated in detail. As the ratio increased above 24:1, the uniform and spherical-like particles became platy particles with bimodal particle size distribution (platy bimodal powder), while the relative density and transmittance of the LaGdZr2O7 ceramics were obviously improved. The highest in-line transmittance of 74.8% at 1100 nm, about 94% of the theoretical transmittance, can be achieved when milling ratio 27:1 was employed. Combined with the high refractive index (2.08 at 632.8 nm), high density (6.446 g/cm3) and high effective atomic number, the highly transparent LaGdZr2O7 ceramics obtained in this work can find potential applications in many areas such as optical lens and promising candidates for scintillator host, etc.

Livebearer fish have a unique reproduction by internal fertilization without supplied nutrition from parents. However, increasing the frequency of spawning remains unknown. Therefore, the study aimed to improve reproductive performance by expanding the spawning frequency in three livebearer fish species: guppy, black molly, and platy. Four sets of 10 fish (6 females and 4 males) aged 80 days after birth were maintained in controlled media at 25-28 °C in the separated tank sized 20x20x15 cm. All the fish were fed commercially and mixed with oocyte developer (OODEV) for 14 days at satiation. By using the same fish, spawning and rematuration were observed for 30 and 45 days respectively. The reproductive performance was evaluated for 45 days. The OODEVtreated broodstock showed birthing the larvae in all tanks on the 7th day after treatment, while control fish displayed on the 14th day. The percentage of pregnant broodstock was 66.6-100% in each tank, indicating the OODEV-supplemented diet can be used to increase oocyte growth in the gonad. In the rematuration experiment, the fish spawned a 3-fold increase in frequencies of spawning. These data suggested that OODEV can stimulate oocyte growth and increase the birthing frequency in livebearers.

The rock fall trajectory and its mechanisms are the most difficult to predict, owing to the complexity of the slope and the Irregular shape of falling rocks. To acquire a better knowledge of the rock fall mechanism of platy rock and to investigate the influence of various impact parameters, a comprehensive physical model experimental study was undertaken based on 3D printing technology using a high-speed camera and specially developed block release system. Based on the experimental results, the effects of the slope angle on the stopping position, the instantaneous kinetic energy and collision position of platy rock block were analyzed. Meanwhile, the effects of movement forms of platy rock before and after collision on the normal coefficient of restitution and the tangent coefficient of restitution were discussed. It is observed that rock fall trajectory depends not only on slope material characteristics, slope angle but also on factors related to the platy block (weight, size and shape). The experimental results showed the value of restitution coefficient exceeding 1 has an important relation with the combination of various movement forms (including the flip motion) and the change of movement forms of platy rock before and after the collision. A new feasible experimental method for research and prevention of rock fall disaster was put forward. It would be important and helpful to the geo-hazard control work.

Discrete element method is used to study the effect of particle aspect ratio on the packing structure of cylinders in this work. Two contact scenarios are complemented to detect particle contacts, following the work of Kodam et al. (Chem Eng Sci 65:5852–5862, 2010) and Guo et al. (Powder Technol 228:193–198, 2012). The results show that the packing density-aspect ratio curve has two small peaks at aspect ratio of 0.625 and 1.25, and a small cusp at aspect ratio of 1.0. Excluded volume is used to explain the variation of packing density with aspect ratio for cylinders, spherocylinders and ellipsoids. The lowest ensemble-averaged coordination number is found at aspect ratio of around 0.75. For platy cylinders, the dominant contact scenario is the face–edge contacts, followed by band–edge contacts. For elongated cylinders, the major contact scenarios are band–edge and band–band contacts. The existence of the planar faces of a platy cylinder makes the radial distribution functions of disks quite different from that of smooth-curved oblates. Most platy cylinders have their principal axis of pointing to and almost paralleling to the vertical direction, while the principal axis of elongated cylinders tends to point to the horizontal plane. The platy particles tend to form stacks composed of 2–4 particles for different aspect ratios. The force gradient increases and force magnitude becomes less uniform when L/D deviates from 1.0.

This thesis deals with the analysis of wage discrimination in top European soccer leagues. Number of papers written about this problem in the past examined either each European league separately or did not examine particular leagues at all. Our thesis investigates discrimination between White, Black, Hispanic and Mediterranean players. We created two unique datasets, including one with game statistics from season 2018/2019 and one with average game statistics from seasons 2016/2017, 2017/2018 and 2018/2019. In addition to analysis of discrimination, we were able to investigate with two different datasets, whether player's wages are determined by statistics from the last season or by average statistics from the last three seasons. The data are examined by applying the Ordinary Least Squares method. The results of our regressions show that there does seem to exist some discrepancy in wage gap between some racial groups represented in our datasets. Our results also show that wages are better determined by the average statistics from the last three seasons.

The platy limestone (plattenkalk) deposit of Vallecillo in northeastern Mexico is widely known for its well preserved and diverse fish and marine reptilian assemblage dated to the early-middle Turonian (Late Cretaceous). A single specimen of the pachyrhizodont G. roberti revealed the first Cretaceous isopod (Crustacea, Arthropoda) attached to a fish host. Preservation allows for the interpretation of the entire body and most appendages. A parasitic lifestyle of the isopod is inferred based on the specimen’s morphology including claw-like dactyli, but is also inferred based on the anoxic bottom conditions variously interpreted for the Vallecillo plattenkalk deposit, which excluded scavengers. The individual is here referred to the family Cymothoidae and described as Mothocya vallecillae n.sp..

To understand the mesoscopic mechanism of clayey soil in view of macroscopic behavior, it is essential to quantitatively calculate the electric double-layer repulsion between arbitrarily inclined clay particles. However, suitable calculation methods with high efficiency and accuracy are still rare at present in literature. Based on a great number of numerical calculations of the repulsion between two inclined platy clay particles, explicit empirical formulae for estimating electric double-layer repulsion between clay particles are put forward. Comparison between the empirical solutions and corresponding numerical results shows that the proposed formulae have a reasonable accuracy, and application of the presented formula is easy and efficient. Keywords: Clay particles, Electric double-layer repulsion, Numerical analysis, Empirical formula

Despite many reviews and original articles, the actual crystal structure of tubular halloysites remains unclear. Analysis of the structural features of defect-free kaolinite, refined by Bish & von Dreele (1989), shows that the ordered 1Tc kaolinite structure can be described equally well by the orthogonal layer cell {a0, b0, γ0} (γ0 = 90°) or by two enantiomorphic oblique layer cells {a1, b1, γ1} and {a2, b2, γ2}, related to each other by a mirror plane. To simulate diffraction effects for tubular halloysite, the parameters and atomic coordinates of the orthogonal layer unit cell and the layer-displacement vectors t1 and t2 responsible for formation of the kaolinite enantiomorphs were deduced by transformation of the parameters of the defect-free kaolinite refined by Bish & von Dreele (1989). Modelling X-ray diffraction patterns show that the samples consist of either single, two or three phases, with the number and their structural features depending on the morphology of the particles. Samples formed of prismatic particles consist of halloysite-like structure (HLS), kaolinite-like structure (KLS) and halloysite cylindrical structure (HCS) phases occurring in various proportions. Samples of proper cylindrical tubes consist of a single HCS phase, whilst samples formed by particles having morphologies intermediate between proper cylindrical and well-developed prismatic forms consist of the KLS and HCS phases. The KLS phase is comparable to low-ordered platy kaolinite with identical unit-cell parameters, layer-displacement vectors and arbitrary stacking faults, except that the layer displacements are not random as in kaolinite, but are distributed at R = 1 such that t1 and t2 displacements have a strong tendency to be segregated. Structural parameters describing the HLS and KLS phases are identical, but in the HLS phase there is a strong tendency to the regular alternation of the t1 and t2 displacements, and the HLS phases do not contain arbitrary stacking faults. A characteristic feature of the three-phase prismatic samples is that the stacking of the layers along the c* axis is periodic and the layer thicknesses are similar to those of platy kaolinite. In contrast, in the KLS phase formed in samples with particles of intermediate morphologies, the hydrated 10 and 7.25 Å layers are interstratified. The relationship between the structural and morphological features of the coexisting phases suggests a sequence of phase formation from the centre to the surface of halloysite tubes that progresses from the HCS to the HLS via the KLS phase. The results of this study demonstrate that all kaolinite and halloysite (7 Å) varieties are built by the same fundamental structural units.

Mica particles are platy, flexible and resilient in nature having numerous intact mica flakes foliated over each other with low stiffness. Presence of mica among sand particles creates complex geom...

Chemical profiles of the essential oils and volatile compounds from the aerial parts of Sclerorhachis platyrachis (Boiss.) Podlech ex Rech.f. obtained through hydrodistillation (HD), solvent-free microwave extraction (SFME), microwave assisted hydrodistillation (MAHD) and headspace solid-phase microextraction (HS-SPME) methods were subsequently investigated by means of GC and GC-MS instruments. Totally, 22, 29, 23 and 17 components were identified in the chemical profiles, representing 98.9%, 96.5%, 97.6% and 97.0% of the total compositions when using the HD, HS-SPME, SFME and MAHD methods, respectively. In all of the samples, more than fifty seven percent of the total structure consisted of monoterpene hydrocarbons. In addition, the second rank of the natural compounds was due to the oxygenated monoterpenes using the aforementioned techniques. β-Pinene was the main constituent in all chemical profiles, while the second rank was related to camphor with the exception of the volatile profile using t...

In order to detect potential sources studied are mineralogical-geochemical special features of the Billyakh River gold placer which belongs to the Ebelyakh diamondiferous area. It is shown that the main sources for the gold are auriferous reservoir rocks of Neogene-Quaternary age. The indicator typomorphic features of the gold include small size (less than 0.5 mm), scaly and platy forms, rough shagreen surface with casts of pressing minerals, and high fineness(900–999 ‰). The most highly informative feature is a strongly modified internal structure of the gold showing evidence of granulation and recrystallisation. Unrounded gold particles are also found in the study area, which suggests proximity of a primary source. They are characterized by a very small size (less than 0.2 mm), angular-cloddy forms, rough, porous surface, widely ranging fineness (535 to 999 ‰), heterogeneous chemical composition, and a complex,multi-phase internal structure. A potential primary source is predicted to be localized at the intersection of N—S and F—W-treading fault zones in the upper Billyakh River. This prediction is supported by the discovery in the river basin of Ebelyakh to disseminate gold-sulfide mineralization confined to the N—S-trending fault zone.

With the help of computed X-ray microtomography with a resolution of 2.75 μm, changes in the microstructure and pore space of aggregates of 3 mm in diameter from the virgin soddy-podzolic soil (Glossic Retisol (Loamic)) in the air-dry, capillary-moistened, and frozen states after five freeze–thaw cycles were studied in a laboratory experiment. The freezing of the samples was performed at their capillary moistening. It was shown that capillary moistening of initially air-dry samples from the humus (AY), eluvial (EL), and illuvial (BT1) horizons at room temperature resulted in the development of the platy, fine vesicular, and angular blocky microstructure, respectively. The total volume of tomographically visible pores >10 μm increased by 1.3, 2.2, and 3.4 times, respectively. After freeze–thaw cycles, frozen aggregates partly preserved the structural arrangement formed during the capillary moistening. At the same time, in the frozen aggregate from the AY horizon, the total tomographic porosity decreased to the initial level of the air-dry soil. In the frozen aggregate from the EL horizon, large vesicular pores were formed, owing to which the total pore volume retained its increased values. The resistance of aggregate shape to the action of freeze–thaw cycles differed. The aggregate from the EL horizon completely lost its original configuration by the end of the experiment. The aggregate from the AY horizon displayed definite features of sagging after five freeze–thaw cycles, whereas the aggregate from the BT1 horizon preserved its original configuration.