Effect of FSP Multipass on Microstructure and Impact Strength of AL6063

I. Introduction Aluminum alloys are very promising for structural applications in aerospace, military and transportation industries due to their light weight, high strength-to-weight ratio and excellent resistance to corrosion. However, the low hardness and low strength of aluminium alloys limit their use, especially for tribological applications. Therefore to enhance these properties several properties enhancement techniques can be used, from them one is Friction Stir Processin

Inhalational Drug Delivery in Pulmonary Aspergillosis

Pulmonary infections have long represented one of the major threats to humans. These vary from acute to chronic conditions, depending upon the underlying disease of the airways. Pulmonary aspergillosis (PMAP) has raised vital concerns in the immunocompromised patients. The fungal infection is difficult to diagnose in the early stages, often making the disease more complicated. Currently, three classes of antifungal agents are available on the market for the treatment of pulmonary infections. These agents are available in oral and intravenous forms only, which limits the availability of therapeutic concentrations of drug in the lungs for longer durations. Consequently, this leads to therapeutic failure and/or resistance of the organism(s) towards the antifungal agents because the optimum amount of drug does not reach the infection site. To combat the issues associated with the conventional regimens, inhalation of antifungal agents is gaining importance because administration to the lungs offers huge advantages of localized and targeted delivery. A wide range of inhalational devices such as nebulizers, dry powder inhalers, and metered dose inhalers are available on the market to deliver drug molecules to the lungs effectively. However, their clinical utility is limited to conditions such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis only. For a few decades, inhalation therapy has also been gaining importance to treat infectious diseases such as tuberculosis and aspergillosis, though more research efforts are required to make the transition from bench to bedside. The current review provides an explicit account of the potential role of inhalation drug delivery in PMAP

Influence of doping on crystal growth, structure and optical properties of nanocrystalline CaTiO3: a case study using small-angle neutron scattering

The effect of dopant size (ionic radius) on the crystal growth, structure and optical properties of nanocrystalline calcium titanate, CaTiO3 (CTO), have been studied using small-angle neutron scattering. X-ray diffraction, along with high-resolution transmission electron microscopy, confirms the growth of pure nanocrystalline CTO. Rietveld analysis reveals that the difference of ionic radii between dopant and host ions induces strain within the lattice, which significantly affects the lattice parameters. The induced strain, due to the difference of ionic radii, causes the shrinkage of the optical band gap, which is manifested by the redshift of the absorbance band. Mesoscopic structural analysis using scattering techniques demonstrates that the ionic radius of the dopant influences the agglomeration behaviour and particle size. A high-resolution transmission electron microscopy study reconfirms the formation of pure highly crystalline CTO nanoparticles

Crystal structure and magnetic properties of Bi0.8A0.2FeO3 (A = La, Ca, Sr, Ba) multiferroics using neutron diffraction and Mossbauer spectroscopy

Bi0.8A0.2FeO3 (A = La, Ca, Sr, Ba) multiferroics were studied using x-ray, neutron diffraction and magnetization techniques. All the samples crystallized in rhombohedral structure with space group R3c. The compounds exhibit antiferromagnetic (AFM) ordering at 300 K and no evidence of further structural or magnetic transition was observed on lowering of temperature below it. The magnetic structure of these substituted compounds are found to be collinear G-type AFM structure as against the non collinear incommensurate magnetic structure reported in the case of parent compound. The moments on Fe at 6 K are aligned along the a-axis in the case of Ca-doped sample. With increase in the ionic radii of dopant, the moments are found to be aligned in the ac plane and the angle of tilt away from the a-axis increases. The observed change in the magnetic structure with substitution is attributed to the intrinsic structural distortion as evidenced by the change in the bond angle (Fe-O-Fe) and bond distances (Bi-O, Fe-O). It has been found that heterovalent substitution A2+ results in the formation of oxygen vacancies in the parent lattices as the possibility of Fe4+ ruled out by Mössbauer spectra recorded at room temperature. Higher value of remnant magnetization (0.4187 emu/g) and coercivity (4.7554kOe) is observed in Bi0.8Ba0.2FeO3 sample in comparison to other substituted samples revealing a strong correlation between ionic radii and magnetization

Switching from pyroelectric to ferroelectric order in Ni-doped CaBaCo4O7

We report ferroelectric ordering in Ni-substituted CaBaCo4O7. Magnetization showed ferrimagnetic transition at 60 K and an additional magnetic anomaly is found at similar to 82 K. The enhanced antiferromagnetic interactions and decrease in saturation magnetization are noticed with Ni substitution. The dielectric and pyroelectric measurements illustrate strong coupling between spin and charge degrees of freedom. Ferroelectric behavior is confirmed with enhanced ordering temperature (similar to 82 K) and saturation polarization (250 mu C/m(2)). Neutron diffraction has revealed an increase in c-lattice parameter in the Ni sample. All the Co/Ni moments are reoriented in the a direction. A transition from a noncollinear ferrimagnetic to a collinear ferrimagnetic spin order, with up arrow up arrow down arrow down arrow antiferromagnetic ordering in the kagome layer, is observedwith substitution. This results in the appearance of unequal bond distances in a two-dimensional collinear layer; most likely this is responsible for the transition from pyroelectric to ferroelectric, with the possibility of switching of electric polarization