Potential contribution of high strength, high modulus aramid fibers to the commercial feasibility of lighter than air craft

Kevlar aramid fiber, fabric, rope and cable performance are reviewed along with the economics relevant to the material, structural, and reliability aspects of lighter than air craft

Glomerular filtration of proteins: Clearance of anionic, neutral, and cationic horseradish peroxidase in the rat

Glomerular filtration of proteins: Clearance of anionic, neutral, and cationic horseradish peroxidase in the rat. Glomerular permeability to horseradish peroxidase, a protein slightly smaller than rat albumin but similar in shape, was studied in Wistar-Furth rats by using a purified neutral isozyme (HRP; molecular radius, ae=29.8 Å) as well as an anionic succinyl-derivative (sHRP ae=31.8 Å) and a cationized enzyme (cHRP, ae=30 Å). The clearance rate of the proteins was determined over a 20-min period using the amounts of enzyme actually filtered (i.e., protein in the urine and protein reabsorbed by tubules). Fractional clearance of cationic HRP (0.338 ± 0.019) exceeded that of neutral HRP (0.061 ± 0.005) by a factor of 5.5 and that of anionic HRP (0.007 ± 0.000) by a factor of 48. Tubular reabsorption was less than 10% of the filtered load. The experimental results indicate marked charge dependency of the filtration of proteins across the glomerulus. Fractional clearances for these proteins are significantly lower than those reported in the literature for dextrans of similar molecular radii. Other molecular properties such as shape and deformability may explain these differences.Filtration glomérulaire des protéines: Clearance de la peroxydase de raifort anionique, neutre ou cationique chez le rat. La perméabilité glomérulaire à la peroxydase de raifort, une protéine un peu plus petite que l'albumine de rat mais semblable par sa forme, a été étudiée chez des rats Wistar-Furth au moyen d'un isoenzyme neutre purifié (HRP; rayon moléculaire, ae = 29,8 Å), d'un dérivé succinylé anionique (sHRP, ae = 31,8 Å) et d'un enzyme cationique (cHRP, ae = 30 Å). La clearance des protéines a été déterminée sur une période de 20min en utilisant les quantités de protéines réellement filtrées (c'est-à-dire les protéines de l'urine et les protéines réabsorbées par les tubes). La clearance fractionnelle de HRP cationique (0,338 ± 0,019) est supérieure à celle de HRP neutre (0,061 ± 0,059 d'un facteur 5,5 et à celle de HRP anionique (0,007 ± 0,000) d'un facteur 48. La réabsorption tubulaire est inférieure à 10% de la charge filtrée. Les résultats expérimentaux indiquent que la filtration glomérulaire des protéines dépend de façon importante de leur charge. Les clearances fractionnelles de ces protéines sont significativement inférieures à celles rapportées dans la littérature pour les dextrans de mêmes rayons moléculaires. D'autres propriétés des molécules, telles que leur forme et leur déformabilité, peuvent expliquer ces différences

Rapid, substrate-independent thickness determination of large area graphene layers

Phase-shifting interferometric imaging is shown to be a powerful analytical tool for studying graphene films, providing quantitative analysis of large area samples with an optical thickness resolution of ≤0.05 nm. The technique is readily able to identify single sheets of graphene and to quantitatively distinguish between layers composed of multiple graphene sheets. The thickness resolution of the technique is shown to result from the phase shift produced by a graphene film as incident and reflected light pass through it, rather than from path-length differences produced by surface height variations. This is enhanced by the high refractive index of graphene, estimated in this work to be nG = 2.99 ± 0.18.The authors wish to acknowledge the Australian Research Council for financial support

IoT-based Secure Data Transmission Prediction using Deep Learning Model in Cloud Computing

The security of Internet of Things (IoT) networks has become highly significant due to the growing number of IoT devices and the rise in data transfer across cloud networks. Here, we propose Generative Adversarial Networks (GANs) method for predicting secure data transmission in IoT-based systems using cloud computing. We evaluated our model’s attainment on the UNSW-NB15 dataset and contrasted it with other machine-learning (ML) methods, comprising decision trees (DT), random forests, and support vector machines (SVM). The outcomes demonstrate that our suggested GANs model performed better than expected in terms of precision, recall, F1 score, and area under the receiver operating characteristic curve (AUC-ROC). The GANs model generates a 98.07% accuracy rate for the testing dataset with a precision score of 98.45%, a recall score of 98.19%, an F1 score of 98.32%, and an AUC-ROC value of 0.998. These outcomes show how well our suggested GANs model predicts secure data transmission in cloud-based IoT-based systems, which is a crucial step in guaranteeing the confidentiality of IoT networks

Influence of Nickel Coating on Flexural and Dynamic Behaviour of Aluminium

AbstractElectroless deposition is an autocatalytic chemical technique to deposit a layer of metal on a thin work piece in the presence of a reducing agent. In this work the changing structure of nickel deposits on aluminum and its alloys at the early stage of electroless nickel deposition using sodium hypophosphite ion as a reducing agent has been studied. The influences of nickel coating on flexural and dynamic behaviour of aluminium are investigated using experimental and numerical methods. Three-point bending tests are performed on coated & uncoated aluminium. The natural frequency of coated specimen and uncoated specimen has been studied. The nickel coating increases the natural frequency in aluminium. Experimental results are compared with finite element Analysis

Self-assembled nanoparticle spirals from two-dimensional compositional banding in thin films

A self-assembly process is reported in which spiral patterns of goldnanoparticles form on siliconsurfaces during the epitaxial crystallization of thin gold-silicon alloy layers. This behavior is observed only for gold concentrations above a critical value and is shown to result from two-dimensional compositional banding of a liquid alloy layer during the crystallization process. The compositional banding consists of alternate gold-rich and silicon-rich alloy bands, which are shown to be a direct consequence of free energy minimization, the band spacing being that which gives the maximum diffusive composition-separation rate. Goldnanoparticles subsequently form by Ostwald ripening on the surface of the gold-rich bands to give rise to the observed spiral patterns.We thank P. Evans and D. Button for MEVVA implantation at Australian Nuclear Science Technology Organization under an AINSE Grant No. AINGRA05155P. We thank S.K. Bhargava at RMIT University for the financial support to D.K.V. to carry out initial stages of this research

Hydrogen bond stabilization in Diels–Alder transition states: The cycloaddition of hydroxy-ortho-quinodimethane with fumaric acid and dimethylfumarate

DFT investigations on the mechanism of Diels–Alder reactions of a hydroxy-ortho-quinodimethane with fumaric acid derivatives were performed to understand the origin of the syn or anti configuration of the adducts. The diene hydroxyl group and the dieneophile carboxyl group show hydrogen bonding in the transition state, significantly favouring the syn product. This reaction is poorly diastereoselective for R = CO₂Me (ratio syn/anti = 57:43) and significantly improved for R = CO₂H (ratio syn/anti = 71:29). The stereoselectivities are properly predicted from transition structures calculated at the B3LYP/6-31G(d) level

A high-energy electron scattering study of the electronic structure and elemental composition of O-implanted Ta films used for the fabrication of memristor devices

High-energy electron scattering is used to investigate Ta films implanted with 10 keV O ions. These films are of interest as they have been used for the fabrication of memristors. High-energy electron scattering is used with incoming electron energies ranging from 5 to 40 keV. The inelastic mean free path, and hence the probing depth, is at these energies of the same order as the range of the implanted ions. At the same time, we can distinguish the mass of the atom that scattered the electron elastically, due to the dependence of the recoil energy on the mass of the scatterer. This allows us to determine quantitatively the atomic composition near the surface from the signal of electrons that have scattered elastically but not inelastically. Electrons that have scattered inelastically as well as elastically provide us with information on the possible electronic excitations. Their signal is used to monitor the presence of the Ta2O5 phase near the surface (characterised by a significant band gap of ’4:5 eV), and estimate at what depth below the surface pure Ta metal is present. In this way, we obtain a fairly detailed picture of the elemental composition and electronic properties of these films.This research was made possible by funding of the Australian Research Council. Oxygen-implanted Tantalum films were provided by Dr. S. Ruffell and Dr. J. England of Varian Semiconductor Equipment, a Division of Applied Materials, as part of a broader collaboration funded by an Australian Research Council Linkage Project Grant. The stay of P.L.G. at the ANU was made possible by a Grant No. 10209/12-3 from CAPES (Brazil). S.K.N. gratefully acknowledges RSAA for his Ph.D. scholarship

DELAYED MITOGENIC STIMULATION DECREASES DNA DAMAGE ASSESSED BY MICRONUCLEUS ASSAY IN HUMAN PERIPHERAL BLOOD LYMPHOCYTES AFTER 60CO IRRADIATION

While contradictory reports are available on the yield of dicentric chromosomes (DC) in blood samples stored at different temperature and stimulated to enter into cell cycle, various times gap followed by exposure, limited information is available on the micronucleus (MN) assay. As scoring the micronuclei frequency from the blood lymphocytes of exposed individuals is an alternative to the gold standard DC assay for triage applications, we examined radiation induced MN yield in delayed mitogenic stimulation after irradiation of in vitro. Peripheral blood lymphocytes (PBL) were exposed to low LET (60Co) radiation dose (0.1 to 5Gy) and incubated at 37°C for 2, 6 and 24 hours. The MN frequency obtained in blood samples stimulated 2 hours post-irradiation showed a dose dependent increase and used to construct the dose-response curve. Further, the results also showed that blood samples stimulated twenty four hours of post-irradiation, a significant reduction (p\u3c0.05) in MN frequencies were obtained when compared to that of blood samples stimulated two hours and six hours after post-irradiation (0.5, 1, 3 and 5Gy). The observed result suggests that the prolonged PBL storage without mitogenic stimulation could lead to interphase cell death and a delayed blood sampling could results in underestimation of dose in biological dosimetry