Stabilisation of estuarine sediments with an alkali-activated cement for deep soil mixing applications

In this work,an alternative alkali-activated cement(AAC)made of ladle slag precursor mixed with sodium hydroxide and sodium silicate has been developed to enhance the bearing capacity of estuarine soils in coastal conditions via deep soil mixing(DSM).The AAC was optimized to use a low reactivity precursor(ladle slag)and to deal with a contaminated high-water content natural sediment cured under water.The material performance was analysed by comparison to a mixture made with Portland cement and cured in the same conditions.Flexural and unconfined compressive strength tests as well as seismic waves measurements after 3-,7-,14-and 28-d curing were performed to obtain a relationship between elastic stiffness and strength with curing time for both mixtures.Remarkably,the AAC mix demonstrated superior strength results,exhibiting almost double flexural and compressive strengths after 28 d compared to the Portland cement mix.The AAC mix also showed a higher rate of stiffness increase than the Portland cement mix,which has a higher initial stiffness at young ages but lower stiffness evolution.Leachate analysis confirmed that the proposed AAC could effectively immobilise any contaminants from soil or precursors.The effect of curing under stress was analysed in triaxial compression tests and found to be insignificant,indicating that laboratory data obtained without stress curing can represent the material's behaviour in a DSM column,which will cure under the weight of the column.

Measurement of Plasma Parameters of Calcium and Silicon in a Rock Sample Using Laser Induced Breakdown Spectroscopy

Laser Induced Breakdown Spectroscopic(LIBS)technique was used to detect calcium and silicon in an unknown sample.In this method plasma was generated by Nd∶YAG laser of wavelength 1 064 nm with energy 400 mJ and pulse duration between 5~10ns.The method was applied for the qualitative as well as quantitative analysis.In the qualitative analysis,the electron number density(Ne)of plasma containing calcium and silicon is determined showing that Neof neutral particles is equivalent to 1016(cm-3)whereas for ionized particles it is 1017(cm-3).Plasma temperature is measured using Boltzmann plot method which must be greater than 10 000 k.Intensity ratio method is used for the quantitative analysis shows various elements in abundance with calcium and silicon in majority.

Effect of Cation Proportion on the Structural and Magnetic Properties of Ni-Zn Ferrites Nano-Size Particles Prepared By Co-Precipitation Technique

Ferrites having general formula Ni1-xZnxFe2O4 with x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, and 0.7 were prepared by wet chemical co-precipitation method. The structural and magnetic properties were studied by means of X-ray diffraction, magnetization, and AC susceptibility measurements. The X-ray analysis confirmed the single-phase formation of the samples. The lattice parameter obtained from XRD data was found to increase with Zn content x. The cation distribution was studied by X-ray intensity ratio calculations. Magnetization results exhibit collinear ferrimagnetic structure for x≤0.4, and which changes to non-collinear for x〉0.4. Curie temperature TC obtained from AC susceptibility data decreases with increasing x.

On Thermodynamics of AdS Black Holes in Arbitrary Dimensions

Considering the cosmological constantΛas a thermodynamic pressure and its conjugate quantity as a thermodynamic volume as proposed by Kubiznak and Mann[J.High Energy Phys.1207(2012)033],we discuss the critical behavior of charged AdS black hole in arbitrary dimensions d.In particular,we present a comparative study in terms of the spacetime dimension d and the displacement of critical points controlling the transition between the small and the large black holes.Such behaviors vary nicely in terms of d.Our result shows that the equation of state for a charged Reissner–Nordstrom AdS black hole predicts an universal number given by(2d-5)/(4d-8).The three-dimensional solution is also discussed.

STIR, SPIR and SPAIR techniques in magnetic resonance of the breast: A comparative study

The amount of fat is a component that complicates the clinical evaluation and the differential diagnostic between benign and malign lesions in the breast MRI examinations. To overcome this problem, an effective erasing of the fat signal over the images acquisition process, is essentials. This study aims to compare three fat suppression techniques (STIR, SPIR, SPAIR) in the MR images of the breast and to evaluate the best image quality regarding its clinical usefulness. To mimic breast women, a breast phantom was constructed. First the exterior contour and, in second time, its content which was selected based on 7 samples with different components. Finally it was undergone to a MRI breast protocol with the three different fat saturation techniques. The examinations were performed on a 1.5 T MRI system (Philips?). A group of 5 experts evaluated 9 sequences, 3 of each with fat suppression techniques, in which the frequency offset and TI (Inversion Time) were the variables changed. This qualitative image analysis was performed according 4 parameters (saturation uniformity, saturation efficacy, detail of the anatomical structures and differentiation between the fibroglandular and adipose tissue), using a five-point Likert scale. The statistics analysis showed that anyone of the fat suppression techniques demonstrated significant differences compared to the others with (p > 0.05) and regarding each parameter independently. By Fleiss’ kappa coefficient there was a good agreement among observers P(e) = 0.68. When comparing STIR, SPIR and SPAIR techniques it was confirmed that all of them have advantages in the study of the breast MRI. For the studied parameters, the results through the Friedman Test showed that there are similar advantages applying anyone of these techniques.

Influence of Saliva and Mucin on the Adhesion of <i>Candida</i>Oral Clinical Isolates

Objectives: This research work intends to clarify the role of artificial saliva, in particularly the role of mucin, a salivary protein, on the surface properties and adhesion ability of Candida spp. oral clinical isolates to abiotic surfaces. Methods: Four oral clinical isolates of Candida spp. were used: two Candida albicans strains (AC;AM) and two Candida parapsilosis strains (AD;AM2). The strains were isolated from patients using oral prosthesis. The microorganisms were cultured in the absence or presence of mucin and artificial saliva, and their adhesion to an abiotic surface (coated with mucin and artificial saliva) was evaluated. Results: The presence of mucin per se onto the abiotic surface decreased the adhesion of all strains, although the combination of mucin with artificial saliva had reduced this effect. No direct correlation between adhesion and the surface free energies of adhesion of the microorganisms was found. Significance: Candida spp. were human commensal microorganisms that became pathogenic when the host immune defenses were compromised. Medical devices were colonized by Candida spp. particularly, oral prostheses, which might lead to the degradation of the prostheses and systemic infections. The salivary secretions that constantly cover the oral cavity influenced Candida spp. adhesion process. Therefore, it was important to understand the interactions between Candida spp., salivary proteins and the characteristic of oral prosthesis when developing materials for oral prostheses.

Large ferro-pyro-phototronic effect in 0.5Ba(Zr_(0.2)Ti_(0.8))O_(3)-0.5(Ba_(0.7)Ca_(0.3))TiO_(3)thin films integrated on silicon for photodetection

Coupling together the ferroelectric,pyroelectric,and photovoltaic characteristics within a single material is a novel way to improve the performance of photodetectors.In this work,we take advantage of the triple multifunctionality shown by 0.5Ba(Zr_(0.2)Ti_(0.8))O_(3)-0.5(Ba_(0.7)Ca_(0.3))TiO_(3)(BCZT),as demonstrated in an Al/Si/SiOx/BCZT/ITO thin-film device.The Si/SiOx acts as an n-type layer to form a metal-ferroelectric-insulator-semiconductor heterostructure with the BCZT,and with Al and ITO as electrodes.The photo-response of the device,with excitation from a violet laser(405 nm wavelength),is carefully investigated,and it is shown that the photodetector performance is invariant with the chopper frequency owing to the pyro-phototronic effect,which corresponds to the coupling together of the pyroelectric and photovoltaic responses.However,the photodetector performance was significantly better than that of the devices operating based only on the pyro-phototronic effect by a factor of 4,due to the presence of ferroelectricity in the system.Thus,after a poling voltage of−15 V,for a laser power density of 230mW/cm^(2)and at a chopper frequency of 400Hz,optimized responsivity,detectivity,and sensitivity values of 13.1mA/W,1.7×10^(10)Jones,and 26.9,respectively,are achieved.Furthermore,ultrafast rise and fall times of 2.4 and 1.5μs,respectively,are obtained,which are 35,000 and 36,000 times faster rise and fall responses,respectively,than previous reports of devices with the ferro-pyro-phototronic effect.This is understood based on the much faster ferroelectric switching in ferroelectric thin films owing to the predominant 180°domains in a single direction out of plane.

A Posteriori Stabilized Sixth-Order Finite Volume Scheme with Adaptive Stencil Construction:Basics for the 1D Steady-State Hyperbolic Equations

We propose an adaptive stencil construction for high-order accurate finite volume schemes a posteriori stabilized devoted to solve one-dimensional steady-state hyperbolic equations.High accuracy(up to the sixth-order presently)is achieved,thanks to polynomial recon-structions while stability is provided with an a posteriori MOOD method which controls the cell polynomial degree for eliminating non-physical oscillations in the vicinity of dis-continuities.We supplemented this scheme with a stencil construction allowing to reduce even further the numerical dissipation.The stencil is shifted away from troubles(shocks,discontinuities,etc.)leading to less oscillating polynomial reconstructions.Experimented on linear,Burgers',and Euler equations,we demonstrate that the adaptive stencil technique manages to retrieve smooth solutions with optimal order of accuracy but also irregular ones without spurious oscillations.Moreover,we numerically show that the approach allows to reduce the dissipation still maintaining the essentially non-oscillatory behavior.

Self-Assembled Dextrin Nanogel as Curcumin Delivery System

Curcumin is a natural polyphenol with anti-oxidative, anti-inflammatory and anti-cancer properties. Its therapeutic potential is substantially hindered by the rather low water solubility and bioavailability, hence the need for suitable carriers. In this study, we show that self-assembled nanogels obtained from hydrophobically modified dextrin are effective curcumin nanocarriers. The stability and loading efficiency of curcumin-loaded nanogel depends on the nanogel/curcumin ratio. Higher stability of the formulation is achieved in water than in PBS buffer, as evaluated by dynamic light scattering and fluorescence measurements. The in vitro release profile, using sink conditions, indicates that dextrin nanogel may perform as a suitable carrier for the controlled release of curcumin. Biological activity of curcumin-loaded nanogel in HeLa cell cultures was assessed using the MTS assay.

Fermion Mass Hierarchies in Singlet-Extended Minimal-Supersymmetric-Standard-Model Quivers

In the context of type-IIA orientifold compactifications,we discuss the fermion masses in a two-singlet-extended minimal-supersymmetric-standard-model four-stack quiver with U(3)×Sp(1)×U(1)×U(1)gauge symmetry.The corresponding effective superpotential exhibits hierarchical coupling term scales giving a partial solution to the fermion masses problem.Using the known data with upper bound neutrino masses mvt≤2 eV,we estimate the relevant scales for the model.

Effect of doping in multiferroic BFO:A review

Bismuth ferrite(BFO)nanostructures and thin films have gained attraction as suitable candidates for energy storage and energy conversion due to their high energy storage efficiency,temperature stability and low dielectric loss.Electrical properties of such multiferroic materials are tailored by ferroelectric and ferromagnetic constituents and have opened up amazing avenues in elec-trochemical supercapacitor and photovoltaic applications.Dopants play a significant role in optimizing the magnetic and dielec-tric properties of such materials owing to suitable applications.This review highlights the scientific advancements reported in BFO nanostructures for energy applications by optimizing their magnetic and dielectric properties.This paper starts with a brief introduction of BFO and a discussion on the effects of various dopants by different synthesis techniques,and their effects on the magnetic and dielectric properties are also portrayed.Eventually,this review summarizes the various doping effects,which paves way for future research on this multiferroic material.

Electronic and magnetic properties of V-and Cr-doped zinc-blende AlN

The electronic and magnetic properties of the zinc-blende aluminum nitride doped with V and Cr are studied using the density functional theory(DFT),namely the KKR-CPA-PBE method.Pure Al N is found to be a wide band gap semiconductor,and doping V and Cr single impurities generate ferromagnetic half-metallic behavior.Moreover,the values of the formation energy reveal that these compounds are stable systems for all dopant concentrations.A self-consistent energy minimization scheme determines the ferromagnetic state as the stable magnetic state for V-and Cr-doping Al N.A double exchange mechanism is identified as the mechanism responsible for magnetism in our systems.When increasing doping impurities,the total magnetic moments increase linearly and the Curie temperature TC,calculated using the mean-field approximation,shows a significant change.The present findings reveal Cr-and V-doped zincblende Al N as potential candidates for high Curie temperature ferromagnetic materials.

Effect of carbon-doping on structural and dielectric properties of zinc oxide

In this paper,Carbon-doped Zinc Oxide(C-ZnO)samples were prepared using the solid-state reaction method.The influence of carbon-doping on the structural and dielectric properties of ZnO samples was studied.The shift in the highest peak position(101)in XRD patterns of carbon-doped samples was observed.The Raman peak at 581 cm^(-1) in undoped ZnO was shifted and broadened in carbon-doped ZnO samples.The ZnO samples doped with carbon show higher values of dielectric constant(~2400 at 1 kHz)compared to pure ZnO(~9 at 1 kHz)which was due to increase in native point defects in the samples.The ac conductivity(σ_(ac))value of the carbon-doped sample was enhanced by 103 times for((ZnO)_(0.9) C_(0.1))sample.