Chiral Photodetector Based on GaAsN

The detection of light helicity is key for various applications, from drug production to optical communications. However, the light helicity direct measurement is inherently impossible with conventional photodetectors based on III–V or IV–VI non-chiral semiconductors. The prior polarization analysis by often moving optical elements is necessary before light is sent to the detector. A method is here presented to effectively give the conventional dilute nitride GaAs-based semiconductor epilayer a chiral photoconductivity. The detection scheme relies on the giant spin-dependent recombination of conduction electrons and the accompanying spin polarization of the engineered defects to control the conduction band. As the conduction electron spin polarization is, in turn, intimately linked to the excitation light polarization, the light polarization state and intensity can be determined by a simple conductivity measurement. This approach, removing the need for any optical elements in front of a non-chiral detector, could offer easier integration and miniaturization. This new chiral photodetector could potentially operate in a spectral range from the visible to the infra-red using (InGaAl)AsN alloys or ion-implanted nitrogen-free III–V compounds.     

Polyethylenimine‐modified curcumin‐loaded mesoporus silica nanoparticle (MCM‐41) induces cell death in MCF‐7 cell line

Breast cancer accounts for the first highest mortality rate in India and second in world. Though current treatment strategies are effectively killing cancer cells, they also end in causing severe side effects and drug resistance. Curcumin is a nutraceutical with multipotent activity but its insolubility in water limits its therapeutic potential as an anti‐cancer drug. The hydrophilicity of curcumin could be increased by nanoformulation or changing its functional groups. In this study, curcumin is loaded on mesoporous silica nanoparticle and its anti‐cancer activity is elucidated with MCF‐7 cell death. Structural characteristics of Mobil Composition of Matter ‐ 41(MCM‐41) as determined by high‐resolution transmission electron microscopy (HR‐TEM) shows that MCM‐41 size ranges from 100 to 200 nm diameters with pore size 2–10 nm for drug adsorption. The authors found 80–90% of curcumin is loaded on MCM‐41 and curcumin is released efficiently at pH 3.0. The 50 µM curcumin‐loaded MCM‐41 induced 50% mortality of MCF‐7 cells. Altogether, their results suggested that increased curcumin loading and sustained release from MCM‐41 effectively decreased cell survival of MCF‐7 cells in vitro.Inspec keywords: cancer, cellular biophysics, nanoparticles, nanomedicine, biomedical materials, polymers, mesoporous materials, transmission electron microscopy, drugs, adsorptionOther keywords: polyethylenimine‐modified curcumin‐loaded mesoporus silica nanoparticle, MCF‐7 cell line, breast cancer, cancer cells, drug resistance, multipotent activity, therapeutic potential, anticancer drug, mesoporous silica nanoparticle, MCF‐7 cell death, high‐resolution transmission electron microscopy, drug adsorption, curcumin‐loaded MCM‐41, nutraceutical curcumin, size 2 nm to 10 nm, size 100 nm to 200 nm     

Hyperelastic analysis based on a polygonal finite element method

In this contribution, we present a novel polygonal finite element method applied to hyperelastic analysis. For generating polygonal meshes in a bounded period of time, we use the adaptive Delaunay tessellation (ADT) proposed by Constantinu et al. [1 A. Constantinu, P. Steinmann, T. Bobach, G. Farin, and G. Umlauf, The adaptive Delaunay tessellation: A neighborhood covering meshing technique., Comput. Mech., vol. 42, no. 5, pp. 655–669, 2008.[Crossref], [Web of Science ®] , [Google Scholar]]. ADT is an unstructured hybrid tessellation of a scattered point set that minimally covers the proximal space around each point. In this work, we have extended the ADT to nonconvex domains using concepts from constrained Delaunay triangulation (CDT). The proposed method is thus based on a constrained adaptive Delaunay tessellation (CADT) for the discretization of domains into polygonal regions. We involve the metric coordinate (Malsch) method for obtaining the interpolation over convex and nonconvex domains. For the numerical integration of the Galerkin weak form, we resort to classical Gaussian quadrature based on triangles. Numerical examples of two-dimensional hyperelasticity are considered to demonstrate the advantages of the polygonal finite element method.     

Bifurcation,Chaos and its Control in A Fractional Order Power System Model with Uncertainties

The paper investigates the complex nonlinear behavior of a fractional order four dimension power system (FOFDPS). The discrete mathematical model of the FOFDPS is derived and presented. The equilibrium points along with the Eigen values of commensurate and incommensurate FOFDPS are presented. The existence of chaotic oscillations are supported by a positive Lyapunov exponent. Bifurcation plots are derived for both parameters and fractional orders to show the impact of the same on the dynamic behavior of FOFDPS. Having shown the existence of such complex behaviors in the FOFDPS, we present an adaptive fractional order sliding mode control (FOASMC) to suppress the chaotic oscillations. Numerical results are presented to support the theoretical results.     

Study on the degradation of low‐density polyethylene in the presence of cobalt stearate and benzil

Degradable polymers are in great demand for a variety of applications such as packaging, agriculture, and medicine. Polyolefins blended with photodegradants/biodegradants are potential candidates for replacing the nondegradable thermoplastics in areas where litter abatement poses problems. In the present article, the effect of metallic photoinitiators like cobalt stearate and a combination of metallic/nonmetallic photoinitiators, i.e., a mixture of cobalt stearate and benzil, on the photooxidative degradation of low‐density polyethylene (LDPE) films have been investigated. Attempts have been made to correlate the results as a function of mixed additives. Films of LDPE containing varying amounts of cobalt stearate and a combination of benzil and cobalt stearate were prepared. The photodegradation of these films has been monitored by various techniques like FTIR spectroscopy, differential thermal analysis, and density and viscosity measurements. Cobalt stearate was highly effective in accelerating the photodegradation of LDPE films at low concentrations. The addition of benzil to cobalt stearate decreased the rate of photodegradation compared to cobalt stearate alone. A retarding effect was observed when benzil alone was added to LDPE. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 236–243, 2006     

Corrosion performance of coated reinforcing bars embedded in concrete and exposed to natural marine environment

Corrosion behavior of mild steel plain bar embedded in concrete with 28 days compressive strength of 40 N/mm² exposed to natural marine environment at a location in the Gulf of Mannar was studied. This paper reports the results of 1-year study conducted on the reinforced concrete specimens exposed to three different levels. The performance of three different types of corrosion protection by specialty coatings to rebars, namely cement polymer composite, interpenetrating polymer network coating and epoxy coating was also evaluated periodically by measuring open circuit potential measurements and the results are discussed. Biofouling was predominant on completion of 3 months immersion.     

Exploring Transfer Learning Approaches for Head Pose Classification from Multi-view Surveillance Images

Head pose classification from surveillance images acquired with distant, large field-of-view cameras is difficult as faces are captured at low-resolution and have a blurred appearance. Domain adaptation approaches are useful for transferring knowledge from the training (source) to the test (target) data when they have different attributes, minimizing target data labeling efforts in the process. This paper examines the use of transfer learning for efficient multi-view head pose classification with minimal target training data under three challenging situations: (i) where the range of head poses in the source and target images is different, (ii) where source images capture a stationary person while target images capture a moving person whose facial appearance varies under motion due to changing perspective, scale and (iii) a combination of (i) and (ii). On the whole, the presented methods represent novel transfer learning solutions employed in the context of multi-view head pose classification. We demonstrate that the proposed solutions considerably outperform the state-of-the-art through extensive experimental validation. Finally, the DPOSE dataset compiled for benchmarking head pose classification performance with moving persons, and to aid behavioral understanding applications is presented in this work.