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In recent years, electrical spin injection and detection has grown into a lively area of research in the field of spintronics. Spin injection into a paramagnetic material is usually achieved by means of a ferromagnetic source, whereas the induced spin accumulation or associated spin currents are detected by means of a second ferromagnet or the reciprocal spin Hall effect, respectively. This article reviews the current status of this subject, describing both recent progress and well-established results. The emphasis is on experimental techniques and accomplishments that brought about important advances in spin phenomena and possible technological applications. These advances include, amongst others, the characterization of spin diffusion and precession in a variety of materials, such as metals, semiconductors and graphene, the determination of the spin polarization of tunneling electrons as a function of the bias voltage, and the implementation of magnetization reversal in nanoscale ferromagnetic particles with pure spin currents.

Large-scale replication of the natural process of photosynthesis is a crucial subject of storing solar energy and saving our environment. Here, we report femtosecond laser induced self-assembled metal nanostructure arrays, which are easily mass producible on earth-abundant metals, can directly synthesize liquid and solid hydrocarbon compounds from carbon dioxide, water, and sunlight at a production rate of more than 1 × 10⁵ μL/(gh) that is significantly (10³–10⁶ times) higher than those in previous studies.^1,2 The efficiency for storing solar energy of the photosynthesis is about 10% in the present simple experimental setup which can be further improved. Moreover, different from previous artificial photosynthesis works, this phenomenon presents a new mechanism that, through a surface-enhanced photodissociation process, nature-like photosynthesis can be performed artificially.

The quest for novel low-dimensional materials has led to the discovery of graphene and thereafter, a tremendous attention has been paved in designing of its fascinating properties aiming in fabricating electronic devices. Using first-principles calculations, we study the structure, energetic and electronic as well as magnetic properties of graphene induced by the interactions in presence of both external and internal foreign agents in detail. We find that a variety of tunable electronic states, e.g., semiconductor-to-half-metal-to-metal and magnetic behaviors can be achieved under such hierarchical interactions and their influence. We also find that the nature and compositions of foreign substances play a key role in governing the electro-magnetic characteristics of these nanomaterials. In this review, we suggest a few routes for engineering the tunable graphene properties suitable for future electronic device applications.

Nanoshells composed of close-packed nickel nanoparticles have been fabricated on sillca spheres via strong interaction between the metallic cations and ions of the support. The nickel hollow nanoballs can be self-assembled via magnetic field-assisted route, which is confirmed by the transmission electron microscopy. The magnetic properties of Ni nanoshells are discussed. It is expected that the prepared method can be extended to the synthesis of other hollow metal spheres.

Based on the main physical processes of secondary electron emission, experimental results and the characteristics of backscattered electrons (BE), the formula was derived for describing the ratio (β_angle) of the number of secondary electrons excited by the larger average angle of emission BE to the number of secondary electrons excited by the primary electrons of normal incidence. This ratio was compared to the similar ratio β obtained in the case of high energy primary electrons. According to the derived formula for β_angle and the two reasons why β > 1, the formula describing the ratio β_energy of β to β_angle, reflecting the effect that the mean energy of the BE W_AVp0 is smaller than the energy of the primary electrons at the surface, was derived. β_angle and β_energy computed using the experimental results and the deduced formulae for β_angle and β_energy were analyzed. It is concluded that β_angle is not dependent on atomic number z, and that β_energy decreases slowly with z. On the basis of the two reasons why β > 1, the definitions of β and β_energy and the number of secondary electrons released per primary electron, the formula for β_E-energy (the estimated β_energy) was deduced. The β_E-energy computed using W_AVp0, energy exponent and the formula for β_E-energy is in a good agreement with β_energy computed using the experimental results and the deduced formula for β_energy. Finally, it is concluded that the deduced formulae for β_angle and β_energy can be used to estimate β_angle and β_energy, and that the factor that W_AVp0 increases slowly with atomic number z leads to the results that β_energy decreases slowly with z and β decreases slowly with z.

In this paper, leaching behavior of metallic species from steel samples in peracetic acid was investigated. We compared the leaching efficiency between peracetic acid and acetic acid to estimate the role of peroxo functional group for the leaching. As a result, peracetic acid enhanced the leaching ability of metallic species from the high speed steel and the alloy steel samples. MoO₃, Mo, MO₂C, W, WO₃, VC and MnO₂ were effectively leached by peracetic acid, while the stainless steel had a high resistance against corrosion by peracetic acid.

In the present work, a combined route involving first doping of iron or neodymium ions via sol–gel method followed by acidification of the metal-doped TiO₂ particles for the improvement of the photocatalytic capability of TiO₂ was reported. The obtained metal-doped/acidified TiO₂ photocatalysts were thoroughly characterized by X-ray diffraction, Fourier transform infrared analysis, and photoluminescence emission spectra. At the same time, their photocatalytic activities were evaluated in simulant photodegradation of methylene blue (MB). The results based on these characterizations showed that not only a rutile layer formed on the surface of original TiO₂ particles after surface cladding, but also the doped Fe or Nd ion had a favorable effect on suppression of the electron–hole recombination in the titania under ultraviolet light irradiation. Furthermore, the photocatalytic activity of the material obtained by Fe doping and acidification was substantially improved in comparison to the untreated TiO₂. However, the sample prepared from Nd-doping and acidification of TiO₂ showed decreased capability relative to the untreated TiO₂ in degradation of MB under similar conditions. Finally, the reason why the photocatalytic activities of the obtained catalysts are sensitive to the metal-doping was discussed in details.

Based on free-electron model, the calculated inelastic mean escape depth of secondary electrons, experimental one, the energy band of metal, the characteristics and processes of secondary electron emission, maximum number of secondary electrons released per primary electron δ(Φ,E_F)_PEm as a function of parameter K_m, work function Φ and Fermi energy E_F was deduced, where K_m is a constant for a given metal in the energy range 100–800 eV. According to the relationship between maximum secondary electron yield from metal δ(Φ,E_F)_m and δ(Φ,E_F)_PEm, the formula for δ(Φ,E_F)_m as a function of atomic number Z, parameter K_m, Φ and E_F was deduced. Using the deduced formula for δ(Φ,E_F)_m, Z, experimental δ(Φ,E_F)_m, Φ and E_F, K_m relative to alkali metals, K_m relative to earth-alkali metals and the mean value of K_m were computed, respectively. And the formulae for maximum secondary electron yield from alkali metals, earth-alkali metals and metals were obtained and proved to be true, respectively. On the basis of the deduced formula for δ(Φ,E_F)_m and the empirical relation that high Φ are connected with high E_F, it can be concluded that high δ(Φ,E_F)_m are connected with high Φ and vice versa.

Introduction: Additive manufacturing, also known as 3D printing (3DP), is becoming increasingly available to surgeons throughout the world due to recent advancements in technology. 3D printing can produce complex free-form structures that would be impossible using conventional subtractive manufacturing. This offers the possibility to create implants that are better suited to the irregular anatomic shapes found in the human body. The present study aims to examine the surgical outcomes associated with the use of 3D printed metal implants and uncover the value of 3D printing in musculoskeletal surgery. Methods: A systematic review of published literature was performed in June 2017 using the PRISMA protocol. Online bibliographic databases such as MEDLINE, Embase, Scopus, CINAHL, and Cochrane were used to identify studies involving surgical implantation of 3D printed metal implants in musculoskeletal surgery. References from relevant studies were scanned for additional articles. Two reviewers independently screened results. Full-text articles were analyzed for eligibility. A total of 24 studies were included for data abstraction. Results were collected and qualitatively analyzed. Results: Of the 25 articles included, there were 17 case reports, 4 case series, 2 retrospective cohorts and 3 prospective cohorts. Of these articles, the majority of 3DP was done with electron beam melting (EBM) with Ti6Al4V. Orthopaedic, neurosurgical, plastic, and maxillofacial surgery articles were included in the review. All studies concluded that 3D printed implants had favourable post-operative outcomes. Some advantages included the reduction of operative time, improved osseointegration through custom implant porosity, improved fixation, decreased stress shielding, better cosmetic appearance, improved functional outcome, and limb salvage. Additional cost and time required to design and print the implants were reported as potential drawbacks to 3D printing. Discussion/Conclusions. The applications of 3D printing in musculoskeletal surgery are promising and have the potential to alter future surgical practice. However, there is a lack of quality research in the literature assessing the use of 3D printed implants. Further research is needed to evaluate the use of 3D printing in musculoskeletal surgery to understand its potential effects on surgical practice.

A study on recombination of neutral oxygen atoms on the surface of different metals is presented. The source of oxygen atoms was a weakly ionized highly dissociated oxygen plasma created in an inductively coupled radio-frequency discharge. Ionized particles as well as excited molecules were effectively recombined and de-excited on the walls of a noncatalytic tube between the discharge and the experimental chamber, so the gas in the latter consisted only of well-thermalized neutral molecules and atoms. The density of oxygen atoms in the experimental chamber was measured with a catalytic probe. Depending on discharge parameters, the O density was between 2×10²⁰ and 5×10²¹ m^-3. Thin foils of different metals were mounted in the experimental chamber and exposed to oxygen atoms. Due to heterogeneous surface recombination of oxygen atoms on the surface of the samples, the metal temperature was increased well above the ambient temperature. The recombination coefficient was calculated from the foil temperature using physical formalism. Among the materials tested the highest recombination coefficient of 0.41 was found for pure polycrystalline iron. The recombination coefficient for flat and well-oxidized nickel, copper, stainless steel, and niobium were found to be 0.27, 0.23, 0.07, and 0.09, respectively, while the recombination coefficient for nanostructured niobium was 0.8. The accuracy of these values was estimated to be about 30%.

Advanced forming technologies have been evolving at a rapid pace with the products applicability in the industrial fields of aerospace and automobile especially for the materials like aluminum and titanium alloys (light weight) and ultra-high strength steels. Innovative forming methods like hydroforming (tube and sheet) have been proposed for industries throughout the world. The ever-increasing needs of the automotive industry have made hydroforming technology an impetus one for the development and innovations. In this paper, the review on various developments towards lightweight materials for different applications is presented. The influencing process parameters considering the different characteristics of the tube and sheet hydroforming process have also been presented. General ideas and mechanical improvements in sheet and tube hydroforming are given late innovative work exercises. This review will help researchers and industrialists about the history, state of the art in hydroforming technologies of the lightweight materials.

We report routes towards synthesis of novel $\pi$-conjugated freebase cobalt, copper, gallium and manganese meso-alkynylcorroles. UV-vis spectra show that extensive peak broadening, red shifts, and changes in the oscillator strength of absorptions increase with the extension of $\pi$-conjugation. Using density functional theory (DFT), we have carried out a first theoretical study of the electronic structure of these metallocorroles. Decreased energy gaps of about 0.3–0.4 eV between the HOMO and LUMO orbitals compared to the corresponding copper, gallium and manganese meso-5,10,15 triphenylcorrole are observed. In all cases, the HOMO energies are nearly unperturbed as the $\pi$-conjugation is expanded. The contraction of the HOMO–LUMO energy gaps is attributed to the lowered LUMO energies.

Foam–metal composites are being increasingly used in a variety of applications. One important aspect in the structural integrity of foam–metal interface is the ability to resist failure around the interface whilst ensuring required load bearing capacity. This study investigated the mechanical and failure behavior at the interface region at micro-scale. The foam–metal composite consisted of polyurethane (PU) foam directly adhered to a galvanized steel face sheet. Optical, scanning electron and atomic force microscopies were used to examine the interface geometry and to obtain a realistic surface profile for use in a finite element (FE) model. Finite element analysis (FEA) was used to study the effects of different interfacial roughness profiles on the mechanical interlocking and modes of failure, which are directly related to the interfacial strength. A set of FE models of idealized surface pairs of different geometries and dimensions were developed based on the microscopic observations at the foam–metal interface. The FE modeling results show that the micro-scale roughness profile at the foam–metal interface causes mechanical interlocking and affects the stress field at the scale of the interface surface roughness, which consequently governs the specific failure mode and the relative proportion of the cohesive to adhesive failure in the interface region for a given foam–metal interface. It was found that the aspect ratio (relative width and height) and width ratio (relative spacing) of roughness elements have a significant effect on the stresses and deformations produced at the interface and consequently influence the modes (cohesive or adhesive) of failure.

Albumin is the most versatile carrier protein in plasma, possessing multiple functions; a reduced amount of albumin in the body is associated with different kinds of diseases such as hypovolemia and hypoproteinemia. The demand for albumin increased for various indications in shocks, burns, cardiopulmonary bypass, acute liver failure and research applications. Several potential problems associated with the preparation and administration of this substance arise from purity, sterilization process and vascular membrane permeability. The present review discusses the potential of metallic, quantum dots and carbon-based nanocarriers to improve the quality of blood products and the effect of these nanoparticles on albumin products. The effects of these nanoparticles on albumin products with a focus on toxicity aspects, structural alteration, stressing conditions, stabilizing agents and unwanted leakage are highlighted. Our literature review indicated the enhanced efficiency of AuNPs in metallic nanoparticles and better performance of negatively charged QDs on albumin products, which provided important information for possible safe use in medical applications. Moreover, among carbon-based nanoparticles, GO had relatively improved effects on albumin unwanted leakage and fibrillation. This review suggests an agenda for scientists to use and design nanoparticles to improve albumin products for various applications.

Titanium thin films were deposited by DC magnetron sputtering. The glancing angle deposition (GLAD) method was implemented to prepare two series of titanium films: perpendicular and oriented columnar structures. The first series was obtained with a conventional incident angle α of the sputtered particles (α = 0°), whereas the second one used a grazing incident angle α = 85°. Afterwards, the films were annealed in air using six cycles of temperature ranging from 293 K to 773 K. DC electrical conductivity was measured during the annealing treatment. Films deposited by conventional sputtering (α = 0°) kept a typical metallic-like behavior versus temperature (σ_{300 K} = 2.0 × 10⁶ S m^-1 and TCR_{293 K} = 1.52 × 10^-3 K^-1), whereas those sputtered with α = 85° showed a gradual transition from metal to dielectric. Such a transition was mainly attributed to the high porous structure, which favors the oxidation of titanium films to tend to the TiO₂ compound.

The concept of texturing steel surfaces were attempted to ease the surface wear and to prevent the release of harmful ions in the conventional joint replacement systems. The surfaces of the bio-compatible steels were textured by photolithography and electrochemical etching techniques to lower the friction coefficient and hence reduce the wear of the surface. Experimental results confirmed that the surfaces with textures (grooves) showed lower friction coefficient compared to un-textured surfaces at a high load (50 N). The friction coefficient could be further reduced for a lower load (10 N) through optimizing the generated hydrodynamic lift. A significant 47% reduction of friction coefficient was archived by tailoring the orientation and size of the textures on the stainless steel surface. The demonstrated strategy in this study would thus offer exciting avenues for developing artificial joint systems that last the full duration of the patients' life without any side-effect concerns.

The chapter deals with some important aspects of the relationship of lithium and nickel with the ecosystem, which consists mainly of soil, water, plants and air. Some aspects of lithium and nickel use in the energy industry are also mentioned. We begin by considering the fact that the metallic elements lithium and nickel, either alone or in the form of their chemical compounds, are currently considered potential energy materials whose applicability is increasing with the transition to the mass use of electricity and batteries for powering motor vehicles. Both lithium and nickel are commonly found in nature. Even in relatively low concentrations, their presence is very dangerous or even toxic to some animals and biological organisms. On the other hand, certain plants and animals are a natural part of ecosystems and are unable to survive with-out their presence because they are vital to them. This contradiction and its implications form the main content of this chapter. The most significant effects of lithium and nickel in the environment, particularly in soil, water and plant systems, are presented. The interconnectedness between soil, water and plants is shown in relation to each other. Some of the analytical methods used for the detection of lithium and nickel are also given. In addition, some specific results are presented, which are not intended to specify particular locations in the field, but rather to highlight the ability of researchers to monitor the presence of lithium and nickel in the environment and to create conditions for their removal and possible reuse.

The role of metallurgical markets with an emphasis on gold futures will be discussed in this chapter. Gold has played an historical role as a hedge against inflation. This chapter reviews the industrial organization of the global gold market and evaluates the effectiveness of gold as a hedge against inflation. Other metallurgical commodities will also be studied such as aluminum, copper, and nickel.