PVA/Gd2O3@Zno Nanocomposite Films as New Uv-Blockers: Structure and Optical Revelations

Journal of Inorganic and Organometallic Polymers and Materials - Herein we have synthesised Gadolinium oxide doped Zinc oxide (Gd2O3@ZnO) by solution combustion method and incorporated it as a...     

Single-crystal relaxor ferroelectric piezoactuators with interdigitated electrodes

We report on the fabrication and performance of (1-x) Pb(Zn(1/3)Nb(2/3))O3-xPbTiO3 (PZN-PT) single-crystal relaxor piezoactuators with interdigitated electrodes patterned on a single surface. An electric field gradient across the sample thickness induces a differential contraction between opposite faces, and it is responsible for the actuation. The samples are poled by energizing the electrodes at 100 degrees C and cooling in a field. Calculations of the piezoelectric response based on a periodically modulated dipolar field yield good agreement with experiment. Discrepancies with the model are ascribed to multidomain formation in the ferroelectric sample as a result of field reversals in the applied electric field along the sample length.     

Sol-gel synthesis and characterisation of (Nd,Cr) co-doped BiFeO3 nanoparticles

Bi_0.95Nd_0.05Fe_1–xCr_xO₃ (x = 0, 0.01, 0.03, 0.05) samples are synthesised by the sol-gel method. The variation in structure, magnetisation, electrical and photocatalytic properties by Cr doping at Fe site in Bi_0.95Nd_0.05FeO₃ samples is analysed. X-ray diffraction pattern confirms the formation of rhombohedral structure in all the samples. The crystallite size is calculated using the Scherrer relation and found to be in nanometre range. Kubelka-Munk theory is used to determine the direct band gap of the samples from reflectance spectra. The saturation magnetisation is found to enhance the concentration of chromium. Arrott-Belov-Kouvel plot confirms the ferromagnetic nature in the samples. The leakage mechanisms are studied to understand the influence of Cr concentration on the BFO. A good correlation exists between the leakage current and ferroelectric behaviour. Photocatalytic tests show degradation of methylene blue dye in the presence of H₂O₂. A drastic decrease in photocatalytic activity is observed with the concentration of Cr.     

Effect of pre-harvest and post-harvest conditions on the fruit allergenicity: A review

Fruits are an important source of vitamins and antioxidants that can effectively delay aging and contribute to health and well-being of the human kind. However, they are growing to be one of the primary elicitors of food allergies around the world. Fruit allergens can induce an IgE-mediated (Immunoglobulin E) reaction, presenting with a symptom like localized oral allergy syndrome (OAS). Numerous studies showed that varying environmental and cultivation conditions can influence the fruit allergen content during flowering and ripening stages. Further, the variety, harvesting maturity, and storage conditions can also significantly influence the allergenicity potential. For example, unripe apples and tomatoes have lower levels of allergens compared to ripened fruits. Researchers have also reported that modified atmosphere packaging (MAP) can help reduce Mal d 3 content present in apples during storage. Post-harvest processing like peeling is also considered a good method to help reduce the overall allergenicity in few fruits whose peel might contain majority of the allergens. This review will discuss the overall influence of both pre-harvest and post-harvest factors on the fruit allergens. We will also discuss the progress regarding the cause, symptoms and diagnostic methods of fruit based allergies.     

Optical Microresonators for Sensing and Transduction: A Materials Perspective

Optical microresonators confine light to a particular microscale trajectory, are exquisitely sensitive to their microenvironment, and offer convenient readout of their optical properties. Taken together, this is an immensely attractive combination that makes optical microresonators highly effective as sensors and transducers. Meanwhile, advances in material science, fabrication techniques, and photonic sensing strategies endow optical microresonators with new functionalities, unique transduction mechanisms, and in some cases, unparalleled sensitivities. In this progress report, the operating principles of these sensors are reviewed, and different methods of signal transduction are evaluated. Examples are shown of how choice of materials must be suited to the analyte, and how innovations in fabrication and sensing are coupled together in a mutually reinforcing cycle. A tremendously broad range of capabilities of microresonator sensors is described, from electric and magnetic field sensing to mechanical sensing, from single‐molecule detection to imaging and spectroscopy, from operation at high vacuum to in live cells. Emerging sensing capabilities are highlighted and put into context in the field. Future directions are imagined, where the diverse capabilities laid out are combined and advances in scalability and integration are implemented, leading to the creation of a sensor unparalleled in sensitivity and information content.     

Microencapsulation of hazelnut oil through spray drying

This study was performed to investigate the influence of air inlet temperature (AIT) on the microencapsulation of hazelnut oil by spray drying. Encapsulated powders were analyzed for moisture content, powder yield, surface oil, encapsulation efficiency (EE), bulk density, and particle morphology. The obtained results demonstrated that moisture content, surface oil, and bulk density decreased by 37.8, 27.5, and 33%, respectively as AIT increased from 140 to 220°C. However, powder yield and encapsulation efficiency increased considerably with the rise in AIT. Higher EEs of about 75–80% were observed in this study.     

Investigations on Structural,Optical and Multiferroic Properties of Bismuth Ferrite Nanoparticles Synthesized by Sonochemical Method

BiFeO₃ nanoparticles have been synthesized using a sonochemical method. The phase identification of the prepared sample was characterized by x–ray powder diffraction, which confirmed the rhombohedral structure. The diffused reflectance spectra showed bands in the ultraviolet and visible regions and the optical band gap was calculated using the Kulbeka–Munk function. The magnetization measurement revealed a ferromagnetic behavior at room temperature and this has been confirmed through an Arrott–Belov–Kouvel plot. The BiFeO₃ nanoparticles exhibit a ferroelectric nature at room temperature and the leakage current density was measured under the applied electric field of ±?30 kV/cm.     

Attribute-based authentication on the cloud for thin clients

We propose two new authentication schemes for the cloud that support private attribute-based authentication services. The basic scheme is non-anonymous attribute-based authentication scheme. The extended scheme of the basic scheme is fully anonymous attribute-based authentication scheme to realize full anonymity and unlinkability services. In the proposed schemes, a user is authenticated by the remote server if the intersection of the set of his/her assigned attributes and the server’s required attributes exceeds a satisfactory predefined level. Unlike existing attribute-based encryption and signature schemes that require the user to perform significant amount of elliptic curve bilinear pairings and modular exponentiations, and require the user to hold a significantly long decryption/signature key, in our schemes the user is not required to perform any bilinear pairings. With a fixed length private key, independent of the number of attributes, the cloud user performs only few exponentiations by which he/she is able to authenticate himself/herself to the remote server and establish a session key with the server with the condition that he/she satisfies a predefined level of the server’s attributes requirement. Therefore, our schemes are suitable for implementation on devices with limited resources. We provide the rigorous security of the proposed schemes and complexity analysis of our schemes. Finally, the security and performance comparisons of our schemes with the existing related schemes show that our schemes outperform other existing schemes.