Development of a Pressure-Sensitive Coating Using Platinum Octaethylporphyrin

In recent years, researchers have developed a new method of measuring the pressure on the surface using sensitive paints. This is an optical technique for determining surface pressure distributions by measuring changes in the intensity, emitted by certain excited molecules. The main advantage of the method over traditional techniques is the high resolution of the information. The only limitation of the resolution of a global map generated by the PSP (pressure-sensitive paint) technique is given by the capabilities of the image capture device. This paper describes the development of a technology for obtaining pressure-sensitive paint, in laboratory conditions, as an advanced measurement technique. The method has an application in many fields such as automotive, aerospace, or even medical.

pH-responsive delivery vehicle based on RGD-modified polydopamine-paclitaxel-loaded poly (3-hydroxybutyrate-co-3-hydroxyvalerate) nanoparticles for targeted therapy in hepatocellular carcinoma

A limitation of current anticancer nanocarriers is the contradiction between multiple functions and favorable biocompatibility. Thus, we aimed to develop a compatible drug delivery system loaded with paclitaxel (PTX) for hepatocellular carcinoma (HCC) therapy. A basic backbone, PTX-loaded poly (3-hydroxybutyrate-co-3-hydroxyvalerate) PHBV nanoparticle (PHBV-PTX-NPs), was prepared by emulsion solvent evaporation. As a gatekeeper, the pH-sensitive coating was formed by self-polymerization of dopamine (PDA). The HCC-targeted arginine-glycine-aspartic acid (RGD)-peptide and PDA-coated nanoparticles (NPs) were combined through the Michael addition. Subsequently, the physicochemical properties of RGD-PDA-PHBV-PTX-NPs were characterized by dynamic light scattering-autosizer, transmission electron microscope, fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetry and X-ray spectroscopy. As expected, the RGD-PDA-PHBV-PTX-NPs showed robust anticancer efficacy in a xenograft mouse model. More importantly, they exhibited lower toxicity than PTX to normal hepatocytes and mouse in vitro and in vivo, respectively. Taken together, these results indicate that the RGD-PDA-PHBV-PTX-NPs are potentially beneficial for easing conflict between multifunction and biocompatible characters of nanocarriers.

Development of a High Temperature Neutron Flux Detector

Ultra Electronics, Energy is currently the supplier of neutron flux instrumentation to the UKs Advanced Gas Cooled Reactor (AGR) fleet. Neutron flux instrumentation provides a safety critical function, giving operators the fastest indication of any transient power behaviour in a nuclear reactor. The operating requirements for these sensors in an AGR reactor are higher than those for equivalent instrumentation in a Pressurised Water Reactor (PWR) or Boiling Water Reactor (BWR). Whilst the underlying physics of these devices is the same, the engineering challenges for AGR instrumentation are different. Design and manufacturing processes have to be more precise due to susceptibility of device performance to a number of factors post installation. The AGR sensor therefore provides a sound engineering platform for the development of an equivalent device for the harsh environments expected in Generation IV reactors. This paper discusses the capabilities of the Ultra Electronics neutron flux detector manufacturing facility and how these capabilities are being expanded to cover the anticipated operating conditions for Generation IV reactor designs. A prototype design has been manufactured and mechanically tested, the sensitive coating process has been developed and the Mineral Insulated (MI) signal cable has been tested at elevated temperature.

Modeling of Interdigital Electrodes Geometrical Parameters Effects on Chemical Sensor Response

The detection of volatile organic compounds (VOCs), humidity and toxic industrial chemicals is important for various environmental and industrial applications. The design of interdigital capacitor (IDCs) sensor is carried out in such a way that it would be suitable for microelectronic technology. The basic geometry of IDCs is defined by some parameters such as: number of electrodes N, electrode width W, electrode length L and the separation between electrodes G. The interactions between IDCs sensitive coating and analyte induced a change in the sensors capacitance due to the permittivity variation of the sensitive layer and to the change in polymer thickness (swelling). In this work, a fairly new approach of IDCs based sensor in terms of capacitance calculation has been presented. The results have been obtained from the modeling of the sensors geometry 2D and 3D using multi-physics simulation software COMSOL. The effects of some geometry parameters coupled with swelling measurements for polymeric films have been studied.

APPLICATION OF THE EARLY DAMAGE DIAGNOSTICS TECHNIQUE TO EXAMINATION OF THE AVIATION PANEL

The results of using early damage diagnostics technique (developed in the Mechanical Engineering Research Institute of the Russian Academy of Sciences (IMASH RAN) for detecting the latent damage of an aviation panel made of composite material upon bench tensile tests are presented. We have assessed the capabilities of the developed technique and software regarding damage detection at the early stage of panel loading in conditions of elastic strain of the material using brittle strain-sensitive coating and simultaneous crack detection in the coating with a high-speed video camera “Video-print” and acoustic emission system “A-Line 32D.” When revealing a subsurface defect (a notch of the middle stringer) of the aviation panel, the general concept of damage detection at the early stage of loading in conditions of elastic behavior of the material was also tested in the course of the experiment, as well as the software specially developed for cluster analysis and classification of detected location pulses along with the equipment and software for simultaneous recording of video data flows and arrays of acoustic emission (AE) data. Synchronous recording of video images and AE pulses ensured precise control of the cracking process in the brittle strain-sensitive coating (tensocoating)at all stages of the experiment, whereas the use of structural-phenomenological approach kept track of the main trends in damage accumulation at different structural levels and identify the sources of their origin when classifying recorded AE data arrays. The combined use of oxide tensocoatings and high-speed video recording synchronized with the AE control system, provide the possibility of definite determination of the subsurface defect, reveal the maximum principal strains in the area of crack formation, quantify them and identify the main sources of AE signals upon monitoring the state of the aviation panel under loading P = 90 kN, which is about 12% of the critical load.