Localized Synthesis of Iron Oxide Nanowires and Fabrication of High Performance Nanosensors Based on a Single Fe2O3 Nanowire

A composed morphology of iron oxide microstructures covered with very thin nanowires (NWs) with diameter of 15–50 nm has been presented. By oxidizing metallic Fe microparticles at 255 °C for 12 and 24 h, dense iron oxide NW networks bridging prepatterned Au/Cr pads are obtained. X‐ray photoelectron spectroscopy studies reveal formation of α‐Fe₂O₃ and Fe₃O₄ on the surface and it is confirmed by detailed high‐resolution transmission electron microscopy and selected area electron diffraction (SAED) investigations that NWs are single phase α‐Fe₂O₃ and some domains of single phase Fe₃O₄. Localized synthesis of such nano‐ and microparticles directly on sensor platform/structure at 255 °C for 24 h and reoxidation at 650 °C for 0.2–2 h, yield in highly performance and reliable detection of acetone vapor with fast response and recovery times. First nanosensors on a single α‐Fe₂O₃ nanowire are fabricated and studied showing excellent performances and an increase in acetone response by decrease of their diameter was developed. The facile technological approach enables this nanomaterial as candidate for a range of applications in the field of nanoelectronics such as nanosensors and biomedicine devices, especially for breath analysis in the treatment of diabetes patients.     

Ru-Containing Polymeric Catalysts for Cellulose Conversion to Polyols

In this paper Ru-containing catalysts based on hypercrosslinked polystyrene (MN-270) and its functional analogues (MN-100 and MN-500) were studied for the first time in cellulose hydrolytic hydrogenation. The catalysts were characterized using transmission electron microscopy (TEM), high resolution TEM, and porosity measurements. Catalytic studies demonstrated that the catalyst containing 1.0 % Ru and based on MN-270 is the most active. The total yield of sorbitol and mannitol was 50 % on the average at 85 % cellulose conversion.     

A combinatorial intra-enterprise exchange for logistics services

The exchange of cargo capacities is a well established approach in logistics. However, only few logistics marketplaces are able to take into consideration synergies that can be generated by combining different transportation routes of different logistics carrierps. In order to exploit these synergies, we designed and implemented the combinatorial exchange mechanism ComEx for the intra-enterprise exchange of delivery orders in a logistics company organized in a profit center structure. Each profit center is able to release delivery orders to an adjacent profit center if the geographic locations of the customers allow for a reduced-cost delivery by the adjacent profit center. We demonstrate that by using the ComEx mechanism, the total cost of transportation of our logistics company can be reduced by up to 14%. Since our iterative auction mechanism is very complex and therefore resource-intensive, we reduce the complexity by applying a convex hull approach combined with a distance-based cost estimator.

High-intensive femtosecond singular pulses in Kerr dielectrics

The nonlinear dynamics of a high-power femtosecond singular pulse in Kerr media are analyzed numerically upon optically induced ionization. We examine the plasma inertia impact to stable propagation of optical vortices. Multifoci behavior of vortices in medium are revealed. Next we numerically demonstrate that inertial character of plasma formation provides a quasi-soliton regime of vortex propagation resistant to symmetry-breaking perturbation.     

Effects of B2O3 on Crystallization,Structure, and Heat Transfer of CaO-Al2O3-Based Mold Fluxes

Metallurgical and Materials Transactions B - The reaction between traditional CaO-SiO2-based mold fluxes and high-Al steel inevitably changes flux composition, and, consequently, flux properties....     

Clinical presentation of HIV infection in patients aged 50 years or older

A case of metachronous malignancy in an elderly postmenopausal lady is presented. She had previously been successfully treated for squamous cell carcinoma of the cervix and now four years later, presented with a right lower lobe lung abscess. On evaluation she was found to have a small cell carcinoma of the lung involving the right intermediate and right lower lobe bronchus. She improved clinically and radiologically with parenteral antibiotics, combination chemotherapy and local external radiotherapy.     

Density functional modelling in multiphase compositional hydrodynamics

This work is essentially a review of a density functional approach in multiphase hydrodynamics developed by the authors during the last 15 years [Dinariev, J Appl Math Mech 1995;59(5):745–752; Dinariev, J Appl Math Mech 1998;62(3):397–405; Demyanov and Dinariev, Fluid Dynam 2004;39(6):933–944; Demianov et al., “Basics of the Density Functional Theory in Hydrodynamics,” Fizmatlit, Moscow; 2009 (in Russian); Dinariev and Evseev, Fluid Dynam 2010;45(1):85–95]. The basic assumption is a representation of the entropy or the Helmholtz energy of the mixture as a functional that is dependent upon chemical component densities. The hydrodynamic system of equations (local conservation laws for chemical components, momentum, and energy) is used to describe multiphase processes, and the constitutive relations (expressions for stresses, diffusion, and heat fluxes) are derived from entropy growth requirement. The authors present the results of numerical simulations describing static and dynamic multiphase systems.     

Enhancement of the Performance of Low-Efficiency HVAC Filters Due to Continuous Unipolar Ion Emission

Our novel concept utilizing continuous emission of unipolar ions, which has been recently proven to enhance the efficiency of facepiece respirators, was applied to conventional HVAC filters. Laboratory study demonstrated that the air ion emission in the vicinity of a low-efficiency HVAC filter significantly improves its performance. For example, the collection efficiency of two commercial HVAC filters challenged with 1μm PSL particles jumped from 5–15% (measured with no ion emission) to 40–90% (when the ion output rate was ～ 10¹² e^?/sec). The enhancement effect depends on the filter type and, generally, on the distance from the ion emitter to the filter surface. The results were explained as follows. The air ions with high mobility are deposited on the fibers forming a macroscopic electric field, which shield out some incoming unipolarly charged particles due to repelling forces. The field estimate has shown that this explanation is feasible. The enhancement effect seems to have a good potential to be employed in industrial and residential ventilation systems as it enhances the aerosol collection efficiency of a low-efficiency HVAC filter while not affecting its pressure drop.     

Bioaerosol Contamination of Ambient Air as the Result of Opening Envelopes Containing Microbial Materials

Mailing envelopes containing pathogenic spores of bacillus anthraxes, which have recently been used by terrorists to infect humans, calls for a new investigation to identify a level of possible contamination of ambient air as a result of the opening of such envelopes. Here we show that opening an envelope and unfolding a letter aerosolize microbial particles located inside and create their cloud with the diameter equivalent to the length of the letter side along which it was folded. With no motion of an envelope recipient (first case study presented in this paper), the front of the cloud moves due to forced convection caused by the impulse at opening and reaches a human face (approximately 50 cm from the opening zone) in about 6 sec. The concentration of particles at that distance is about three times lower compared to the concentration in the source. Further spread of the cloud brings its front to the distances of 1 and 1.5 meters within 25 and 55 seconds with the corresponding concentrations of around 10% and 5% compared to the source respectively. The second case study presents the results for a more realistic scenario when an envelope recipient, after observing a dust cloud appearing as the result of the opening of the envelope, recoils in fright creating additional air flows significantly disturbing the aerosol propagation described in the former study. It was found theoretically and verified by experiments that the amount of particles captured by the letter recipient varies significantly depending on the geometrical characteristics of the human, distance to the opening zone, reaction time, and recoil velocity.