Spanish literature , the body of literary works produced in Spain. Such works fall into three major language divisions: Castilian, Catalan, and Galician. This article provides a brief historical account of each of these three literatures and examines the emergence of major genres. Although literature in the vernacular was not written until the medieval period, Spain had previously made significant contributions to literature. Lucan , Martial , Quintilian , and Prudentius , as well as Seneca the Younger and Seneca the Elder , are among writers in Latin who lived in, or were born in, Spain before the modern Romance languages emerged. Women were also writing in Spain during the Roman period: Serena, believed to have been a poet; Pola Argentaria, the wife of Lucan, whom she is thought to have assisted in writing his Pharsalia ; and the poet and Stoic philosopher Teofila.
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Formation of highly planarized Ni-W electrodeposits for glass imprinting mold. We confirmed that increasing the total metal concentration is effective for the planarization of Ni-W films and Ni-W nanopatterns formed with a uniform height and a nm pitch. At the same time, the W content in Ni-W films decreased. We investigated the relationship between the planarization of Ni-W films and the W content in Ni-W films, and confirmed that increasing the total metal concentration is effective for the inhibition of hydrogen generation.
We pointed to the inhibition of hydrogen gas generation as a cause of the planarization of Ni-W films, and the reduction in the hydrogen generation amount necessary for the deposition of W as a cause of the reduction in the W content in Ni-W films.
In order to obtain a flat plating film with a high W content, it is necessary to generate an adequate amount of hydrogen on the surface of the cathode and to remove hydrogen gas from the cathode surface immediately. Ni-W -mica composite coatings were prepared on C45 steel via pulse electrodeposition from a Watts bath containing mica. The mica particles were co-deposited into the Ni-W coating matrix, and the structures, morphologies and mechanical performances of the coatings were investigated.
Scanning electron microscopy and energy dispersive x-ray spectroscopy revealed that a small amount of mica caused the Ni-W -mica coating to form of a compact and uniform surface structure. The electrochemical behaviors of the coatings were evaluated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy in 3.
The results revealed that the addition of mica to the Ni-W coating could improve the corrosion resistance of the coating. Tafel Polarization and electrochemical Impedance methods were used to evaluate the corrosion resistance behaviour of the nanocomposite coatings in 3.
These results indicated that, the addition of PTFE in the Ni-W alloy matrix has resulted moderate microhardness, smooth surface, less friction coefficient, excellent water repellency and enhanced corrosion resistance of the nanocomposite coatings. Preparation and characterization of NiW -nHA composite catalyst for hydrocracking. The synthesis, characterization and catalytic capability of the NiW -nano-hydroxyapatite NiW -nHA composite were investigated in this paper. The NiW -nHA catalyst was prepared by a co-precipitation method.
TEM observation revealed that this catalyst was needle shaped and the crystal retained a nanometer size. Furthermore, the conversion of The straight chain alkanes ranging from C15 to C18 were the main components in the production. The yield of CC18 alkanes was up to By exploring various HM materials, we show an efficient enhancement or cancellation of the total SOT, depending on the combination of the two HM materials.
We also model our double HM system and show that the effective spin Hall angle has a peak value at certain HM thicknesses. PubMed Central. Electroplated hard chrome coating is widely used as a wear resistant coating to prolong the life of mechanical components. However, the electroplating process generates hexavalent chromium ion which is known carcinogen. Hence, there is a major effort throughout the electroplating industry to replace hard chrome coating.
Composite coating has been identified as suitable materials for replacement of hard chrome coating, while deposition coating prepared using traditional co-deposition techniques have relatively low particles content, but the content of particles incorporated into a coating may fundamentally affect its properties.
This study indicates that higher diamond contents could be successfully co-deposited and uniformly distributed in the Ni-W alloy matrix. Moreover, the addition of diamond particles could significantly enhance the wear resistance of the coatings. Study of electroless Ni-W -P alloy coating on martensitic stainless steel.
Nikitasari, Arini, E-mail: arini-nikitasari yahoo. Electroless nickel phospor Ni-P is widely used in many industries due to their corrosion and wear resistance, coating uniformity, and ability to coat non-conductive surfaces. The unique properties of tungsten such as high hardness, higher melting point, lower coefficient of linear thermal expansion, and high tensile strength have created a lot of interest in developing ternary Ni-W -P alloys. This article presents the study of electroless Ni-W -P alloys coating using acid or alkaline bath on martensitic stainless steel.
Nickel sulfate and sodium tungstate were used as nickel and tungsten sources, respectively, and sodium hypophosphite was used as a reducing agent. Martensitic stainless steel was immersed in Ni-W -P bath for 15, 30, and 60 minutes.
The substrate of martensitic stainless steel was subjected to pre-treatment polishing and cleaning and activation prior to electroless plating. Nanoporous Beta zeolite was dealuminated by weak acid treatment for reducing the acidity. Bi-functional catalysts were prepared using commercial Beta zeolites and the dealuminated zeolites for acidic function, NiW for metallic function.
The acidity of catalyst seemed to play an important role as active sites for the selective ring opening of 1-methylnaphthalene but there should be some optimum catalyst acidity for the reaction. The acidity of Beta zeolite could be controlled by the acid treatment and the catalyst with the optimum acidity for the selective ring opening could be prepared. The development of nanocrystalline materials has been increasingly pursued over the last few decades.
They have been shown to exhibit superior properties compared to their coarse-grain counterparts, and thus present a tremendous opportunity to revolutionize the performance of nanoscale devices or bulk structural materials.
However, nanocrystalline materials are highly prone to grain growth, and if the nanocrystalline grains coarsen, the beneficial properties are lost. There is a strong effort to determine the most effective thermal stability mechanisms to avoid grain growth, but the physical nature of nanocrystalline grain growth is still unclear due to a lack of detailed understanding of nanocrystalline microstructures. Furthermore, the influence of contamination has scarcely been explored with advanced transmission electron microscopy techniques, nor has there been a direct comparison of alloys fabricated with different bulk processes.
Therefore, this research has applied aberration-corrected scanning transmission electron microscopy to characterize nanocrystalline Ni-W on the atomic scale and elucidate the physical grain growth behavior. Three primary objectives were pursued: 1 explore the thermal stability mechanisms of nanocrystalline Ni-W , 2 evaluate the phase stability of Ni-W and link any findings to grain growth behavior, and 3 compare the influences of bulk fabrication processing, including electrodeposition, DC magnetron sputtering, and mechanical alloying, on the thermal stability and phase stability of Ni-W.
Several thermal stability mechanisms were identified throughout the course of this research. First and foremost, W-segregation was scarcely observed to grain boundaries, and it is unclear if W-segregation improves thermal stability contrary to most reports in the 2 literature. Long-range Ni4W chemical ordering was observed in alloys with more than 20 at. In addition, lattice. Moreover, the damage dose dependence of hardness in both alloys can be described by the Makin and Minter's equation, where the effective critical volume of obstacles can be used to represent irradiation hardening resistance of the alloys.
This is ascribed to the fact that the W, instead of Mo in the alloy, can suppress the formation of defects under ion irradiation. Simultaneous fabrication of a microcavity absorber-emitter on a Ni-W alloy film. A process for the simultaneous fabrication of microcavity structures on both sides of a film was proposed and demonstrated to develop a free-standing-type integrated absorber-emitter for use in solar thermophotovoltaic power generation systems.
The absorber-emitter-integrated film comprised a heat-resistant Ni-W alloy deposited by electroplating. A two-step silicon mould was fabricated using deep reactive-ion etching and electron beam lithography. Cavity arrays with different unit sizes were successfully fabricated on both sides of the film; these arrays are suitable for use as a solar spectrum absorber and an infrared-selective emitter.
Phosphonic acid functionalization of nanostructured Ni-W coatings on steel. The functionalization of nanocrystalline Ni-W coatings, formed by galvanostatic pulsed electrodeposition on steel, by thermal treatment of octadecylphosphonic acid self-assembled on the oxidized alloy surface is studied by Raman spectroscopy, contact angle measurements, X-ray photoelectron spectroscopy, AFM and electrochemical techniques. Results show that this procedure preserves the surface topography and the optimum mechanical properties of the alloy.
More importantly, it turns the alloy surface highly hydrophobic and markedly improves its corrosion resistance, in particular to pitting corrosion in aggressive solutions containing chloride anions. The ability of the phosphonate layer to improve surface properties arises from the barrier properties introduced by the hydrocarbon chains and the strong bonds between the phosphonate head and the underlying surface oxides. Tungsten solution kinetics and amorphization of nickel in mechanically alloyed Ni-W alloys.
The kinetics of solution of W, and the subsequent amorphization of Ni, in mechanically alloyed Ni-W alloys has been investigated. As W is a highly abrasive material in the energy intensive devices used for mechanical alloying, we studied the above reactions in different mills. One used hardened steel balls as the grinding media, and the other Al2O3. Abrasion is common to both mills, but Fe wear debris from the hardened steel enters into solution in the Ni rich phases whereas Al2O3 debris is present as small dispersoids.
The kinetics of W solution and those of subsequent amorphization do not appear strongly affected by the Fe in solution or the Al2O3 dispersoid. Tungsten dissolves in crystalline Ni in amounts in excess of the equilibrium solubility during alloying. Amorphization of the Ni phase occurs if the W content in this phase exceeds ca. Synergistic effect between nano-ceramic lubricating additives and electroless deposited Ni-W -P coating.
The major solving ways for the material wear are surface modification and lubrication. Currently, the researches at home and abroad are all limited to the single study of either nano-lubricating oil additive or electroless deposited coating.
The surface coating has high hardness and high wear resistance, however, the friction reduction performance of the coating with high hardness is not good, the thickness of the coating is limited, and the coating can not regenerate after wearing.
The nano-lubricating additives have good tribological performance and self-repair function, but under heavy load, the self-repair rate to the worn surface with the nano-additives is smaller than the wearing rate of the friction pair.
To solve the above problems, the Ni-W -P alloy coating and deposition process with excellent anti-wear, and suitable for industrial application were developed, the optimum bath composition and process can be obtained by studying the influence of the bath composition, temperature and PH value to the deposition rate and the plating solution stability.
The tribological properties as well as anti-wear and friction reduction mechanism of wear self-repair nano-ceramic lubricating additives are also studied. The ring-block abrasion testing machine and energy dispersive spectrometer are used to explore the internal relation between the coating and the nano-lubricating oil additives, and the tribology mechanism, to seek the synergetic effect between the two.
The test results show that the wear resistance of Ni-W -P alloy coating with heat treatment and in oil with nano-ceramic additives has increased hundreds times than 45 steel as the metal substrate in basic oil, the friction reduction performance is improved. This research breaks through the bottleneck of previous separate research of the above-mentioned two methods, and explores the combination use of the two methods in industrial field.
In this study, the tribocorrosion of electroplated Ni-W -P alloy coating 3. The wear and corrosion performance of the coating and their synergic effect were measured at different overpotentials.
The corrosion products were a mixture of NiO, WO3, and phosphate, and the corroded surface was P-rich, porous, and less crystalline than the pristine coating. Corrosion and mechanical wear had little influence on tribocorrosion at low overpotential values. However, the synergic effect drastically became stronger at high overpotentials. The surface was full of large pitting holes and grooves. The weight loss due to the corrosion component increased linearly with the overpotential but was limited in comparison with the wear component, which was the main cause of weight loss.
On the other hand, the friction coefficient first increased and then decreased with an increase in overpotential. Both the surface morphology of the corroded coating and the thickness of the corrosion oxide play important roles in this friction characteristic. Highly alloyed Ni-W substrates for low AC loss applications. Cube texture formation has been studied in Ni-W alloys with a W content of 9 at. These alloys show a low magnetization at 77 K and below, and are therefore excellent candidates for use as substrates of coated conductors in AC applications.
The application of a modified deformation and annealing sequence leads to a highly textured surface of Ni9W and Ni9. In contrast, only a weak cube texture was achieved in Ni10W tapes.
The rolling texture of this alloy showed a significantly increased Goss component, which could not be reduced by applying intermediate annealing treatments. The influence of this texture on the cube texture formation will be discussed in detail. AZ91D magnesium alloy substrate was first pretreated in a phosphoric acid to obtain a phosphate coating, and then, the electroless ternary Ni-W -P coating was deposited using a sulfate nickel bath.
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Formation of highly planarized Ni-W electrodeposits for glass imprinting mold. We confirmed that increasing the total metal concentration is effective for the planarization of Ni-W films and Ni-W nanopatterns formed with a uniform height and a nm pitch. At the same time, the W content in Ni-W films decreased. We investigated the relationship between the planarization of Ni-W films and the W content in Ni-W films, and confirmed that increasing the total metal concentration is effective for the inhibition of hydrogen generation. We pointed to the inhibition of hydrogen gas generation as a cause of the planarization of Ni-W films, and the reduction in the hydrogen generation amount necessary for the deposition of W as a cause of the reduction in the W content in Ni-W films. In order to obtain a flat plating film with a high W content, it is necessary to generate an adequate amount of hydrogen on the surface of the cathode and to remove hydrogen gas from the cathode surface immediately.
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Seedlings of Salicornia bigelovii Torr. The data showed both fresh and dry weight of whole plant of Salicornia bigelovii Torr. Directory of Open Access Journals Sweden. Full Text Available The study and development of plant resources in arid-saline environments is increasing. Salicornia bigelovii is a halophyte of great interest. However, the productivity of these plants is limited by nitrogen availability. An alternative to chemical fertilizers are the plant growth promoting bacteria and mycorrhizae.