Characterization of microdevices for ferrous chloride separation for biosensing applications

Ferrous chloride has a variety of applications such as a reducing flocculation agent in waste-water treatment, especially for wastes containing chromate, in the laboratory synthesis of iron complexes and it is employed as a reducing agent in many organic syntheses. The device used for experiment was fabricated on the silicon wafer as support for two electrodes in a SU8 polymer microchannel with an inlet, for the injection of aqueous solution of ferrous chloride, and two outlets, for the two by-products of separated solutions. The various parameters of the device were measured by White Light Interferometer (WLI) and Scanning Electron Microscopy (SEM). The magnetic field created by applying different types of potential between two electrodes determined ferrous chloride to separate in ferrous oxide and chlorine (in gaseous form). If a protein is added in this solution we have the possibility to immobilize the protein on the iron particles and on the channel area. The electrical results were collected using a semiconductor system analyzer Keithley and were examined subsequently. The Fe complexes deposited on the electrodes were characterized by XRD analyses.     

‘Generation rent’ and the emotions of private renting: self-worth,status and insecurity amongst low-income renters

Abstract

The UK private-rented sector is increasingly accommodating a diverse range of households, many of whom are young people struggling to access other forms of housing. For those at the bottom end of the sector, who typically have limited economic resources, it is a precarious housing tenure due to its expense and insecurity, yet few studies have explored qualitatively the emotional consequences of this for well-being. We address this gap in the ‘generation rent’ literature by focusing attention on those voices that have been less prominent in the literature. Informed by the theoretical lens of ‘residential alienation’, our study illustrates the emotional toll of private renting upon low-income groups in a national context where state regulation is more limited. In doing so, we add nuance to the literature surrounding socio-economic differentiation within the UK private-rented sector. Our arguments are also relevant to an international audience given global concerns about housing precarity and the politics of housing.     

Plasma parameters of argon and argon/molecular gas mixture plasmas produced in microwave discharge

The experimental results and their analysis are presented concerning electron density and temperature of the microwave discharge plasma (power range 100–500 W) produced in Ar gas and Ar–N₂ and Ar–N₂–NO gas mixture at the total pressure of 0.5 Torr. The triple probe method was primarily used in order to set-up a direct and on-time technique to measure electron temperature in complex plasma. The results were compared with those obtained using a cylindrical probe mounted in a circuit with reference electrode. Each probe was made of tungsten wires of 0.5 mm diameter and 3 mm in length each. When plasma contains only one maxwellian group of electrons, within the experimental errors, both the probes systems get comparable value of plasma parameters. When the characteristic of cylindrical probe shows two groups of thermal electrons within the microwave plasma the triple probe may show always results concerning one group but of which temperature depends on the ratio of the densities of those two groups of electrons.     

Magnesia supported Au and Ag catalysts for the preparation of few-layer graphene–metal nanocomposites: relationship between catalyst structure and the properties of graphene composites

Magnesia supported Au, Ag, and Au–Ag nanostructured catalysts were prepared, characterized, and used to synthesize few-layer graphene–metal nanoparticle (Gr–MeNP) composites. The catalysts have a mezoporous structure and a mixture of MgO and MgO·H₂O as support. The gold nanoparticles (AuNPs) are uniformly dispersed on the surface of the Au/MgO catalysts, and have a uniform round shape with a medium size of ~8 nm. On the other hand, the silver nanoparticles (AgNPs) present on the Ag/MgO catalyst have an irregular shape, larger diameters, and less uniform dispersion. The Au–Ag/MgO catalyst contains large Au–Ag bimetallic particles of ~20–30 nm surrounded by small (5 nm) AuNPs. Following the RF-CCVD process and the dissolution of the magnesia support, relative large, few-layer, wrinkled graphene sheets decorated with metal nanoparticles (MeNPs) are observed. Graphene–gold (Gr–Au) and graphene–silver (Gr–Ag) composites had 4–7 graphitic layers with a relatively large area and similar crystallinity for samples prepared in similar experimental conditions. Graphene–gold–silver composites (Gr–Au–Ag) presented graphitic rectangles with round, bent edges, higher crystallinity, and a higher number of layers (8–14). The MeNPs are encased in the graphitic layers of all the different samples. Their size, shape, and distribution depend on the nature of the catalyst. The AuNPs were uniformly distributed, had a size of about 15 nm, and a round shape similar to those from Au/MgO catalyst. In Gr–Ag, the AgNPs have a round shape, very different from that of the Ag/MgO catalyst, large size distribution and are not uniformly distributed on the surface. Agglomerations of AgNPs together with large areas of pristine few-layer graphene were observed. In Gr–Au–Ag composites, almost exclusively large bimetallic particles of about 25–30 nm, situated at the edge of graphene rectangles have been found.     

Face Editing Using Part-Based Optimization of the Latent Space

We propose an approach for interactive 3D face editing based on deep generative models. Most of the current face modeling methods rely on linear methods and cannot express complex and non-linear deformations. In contrast to 3D morphable face models based on Principal Component Analysis (PCA), we introduce a novel architecture based on variational autoencoders. Our architecture has multiple encoders (one for each part of the face, such as the nose and mouth) which feed a single decoder. As a result, each sub-vector of the latent vector represents one part. We train our model with a novel loss function that further disentangles the space based on different parts of the face. The output of the network is a whole 3D face. Hence, unlike part-based PCA methods, our model learns to merge the parts intrinsically and does not require an additional merging process. To achieve interactive face modeling, we optimize for the latent variables given vertex positional constraints provided by a user. To avoid unwanted global changes elsewhere on the face, we only optimize the subset of the latent vector that corresponds to the part of the face being modified. Our editing optimization converges in less than a second. Our results show that the proposed approach supports a broader range of editing constraints and generates more realistic 3D faces.     

On heat transfer in external natural convection flows using two nanofluids

In the present work, a theoretical model based on the integral formalism approach for both laminar and turbulent external natural convection is extended to nanofluids. By using empirical models based on experimental data for computing viscosity and thermal conductivity of water–alumina and water–CuO suspensions, a close attention is first focused on the influence due to increasing the volume fraction of nanoparticles on the heat transfer and then to the transition threshold between laminar and turbulent regimes. The heat transfer is shown to strongly depend on the flow regime and on particle volume fraction. A clear degradation of heat transfer is observed using nanofluids while compared to that of the base-fluid. Moreover, the fact of increasing the particle volume fraction tends to delay the occurrence of the flow transition to turbulence.     

Polymeric Materials with Magnetic Properties

The paper deals with the study of the magnetic properties of some mechanochemically synthesized polychelates. Some spectral analysis methods such as ESR spectroscopy, atomic absorption spectroscopy, and especially Mössbauer spectroscopy are used for this purpose. The presence of metallic atoms (especially Fe) is responsible for the magnetic properties of these mechanochemically synthesized macromolecular compounds.     

Polymerization of Styrene Initiated with Cumyl 4-t-Butylazo-4-Cyanoperoxypentanoate

The paper reports on the synthesis of a new bifunctional radicalic initiator and its behavior in the polymerization process. The synthesis of cumyl 4-t-butylazo-4-cyanoperoxypentanoate has been achieved by condensation of the corresponding acid chloride with cumen hydroperoxide. The structure of the azo perester is confirmed by IR, UV, and NMR spectra. The initiator has been used in styrene polymerization and the conversion of the polymer studied in connection to monomer and initiator concentration, time of reaction, and temperature. In compliance with multiple regression method, an equation correlating the PS conversion with the previously mentioned variables has been established.     

Spectroscopic evidence for the bulk polymerization of N-vinyl carbazole in the presence of single-walled carbon nanotubes

The bulk polymerization reaction of N-vinylcarbazole (VK) at 70 °C in the presence of single-walled carbon nanotubes (SWNTs) leads to a new composite, whose optical properties were studied by photoluminescence (PL), surface enhanced Raman scattering (SERS) and Fourier transform infrared (FTIR) spectroscopies. A dramatic reduction of the poly(N-vinylcarbazole) (PVK) PL efficiency and a change in the vibrational structure of the PL spectrum of this polymer were observed by adding SWNTs to the synthesis mixture. Steric hindrance effects were evidenced both in SERS spectra of the VK when it interacts mechanico-chemically with SWNTs and in FTIR spectra of the un-doped PVK/SWNTs' composites. Cyclic voltammetry was used to demonstrate the doping process of PVK in PVK/SWNTs' composite.     

Effect of hydrolyzed collagen on thermal,mechanical and biological properties of poly(lactic acid) bionanocomposites

Iranian Polymer Journal - Bionanocomposites based on poly(lactic acid) (PLA), plasticized with commercial tributyl o-acetyl citrate (ATBC) and containing hydrolyzed collagen (HC) up to...