Three-Dimensional Surface Texture Characterization of Portland Cement Concrete Pavements

Abstract:   This article investigates the effectiveness of different mathematical methods in describing the three-dimensional surface texture of Portland cement concrete (PCC) pavements. Ten PCC field cores of varying surface textures were included in the analysis. X-ray Computed Tomography (CT) was used to scan the upper portion of these cores, resulting in a stack of two-dimensional grayscale images. Image processing techniques were utilized to isolate the void pixels from the solid pixels and reconstruct the three-dimensional surface topography. The resulting three-dimensional surfaces were reduced to two-dimensional "map of heights" images, whereby the grayscale intensity of each pixel within the image represented the vertical location of the surface at that point with respect to the lowest point on the surface. The "map of heights" images were analyzed using four mathematical methods, namely the Hessian model, the Fast Fourier transform (FFT), the wavelet analysis, and the power spectral density (PSD). Results obtained using these methods were compared to the mean profile depth (MPD) computed in accordance with ASTM E1845 .     

AutoRWN: automatic construction and training of random weight networks using competitive swarm of agents

Neural Computing and Applications - Random Weight Networks have been extensively used in many applications in the last decade because it has many strong features such as fast learning and good...     

Improved Archimedes Optimization Algorithm with Deep Learning Empowered Fall Detection System

Human fall detection (FD) acts as an important part in creating sensor based alarm system, enabling physical therapists to minimize the effect of fall events and save human lives. Generally, elderly people suffer from several diseases, and fall action is a common situation which can occur at any time. In this view, this paper presents an Improved Archimedes Optimization Algorithm with Deep Learning Empowered Fall Detection (IAOA-DLFD) model to identify the fall/non-fall events. The proposed IAOA-DLFD technique comprises different levels of pre-processing to improve the input image quality. Besides, the IAOA with Capsule Network based feature extractor is derived to produce an optimal set of feature vectors. In addition, the IAOA uses to significantly boost the overall FD performance by optimal choice of CapsNet hyperparameters. Lastly, radial basis function (RBF) network is applied for determining the proper class labels of the test images. To showcase the enhanced performance of the IAOA-DLFD technique, a wide range of experiments are executed and the outcomes stated the enhanced detection outcome of the IAOA-DLFD approach over the recent methods with the accuracy of 0.997.     

Hydrogen adsorption and kinetics in MIL-101(Cr) and hybrid activated carbon-MIL-101(Cr) materials

Since the last 15 years, porous solids such as Metal–Organic Frameworks (MOFs) have opened new perspectives for the development of adsorbents for hydrogen storage. Among all MOF materials, the chromium (III) terephthalate-based MIL-101(Cr) is a very stable one which exhibits a good uptake capacity of hydrogen (H₂). In this study, syntheses were carried out in soft conditions without hydrofluoric acid as usually reported in literature. Moreover, activated carbon (AC) was introduced in the preparation of the MOF-based adsorbents to create hybrid materials with large specific surface areas (AC-MOF). Hydrogen storage capacities were assessed at 77 K up to 100 bar, and the measurements of adsorption isotherms were performed using both volumetric and gravimetric methods. The experimental data were shown to be in good agreement. A maximal excess hydrogen uptake of 67.4 mol kg^?1 (13.5 wt.%) has been reached by the hybrid AC-MOF adsorbent at 77 K under 100 bar. The hydrogen storage capacity was so shown to be greatly enhanced by AC addition, as a maximal value of only 41.1 mol kg^?1(8.2 wt.%) was reported for the pristine MIL-101(Cr), under the same conditions. Finally, hydrogen adsorption kinetics were examined at 77 K using experimental transient adsorption curves obtained using volumetric method, and the Linear Driving Force (LDF) model was tested for their interpretation. According to this model, diffusion coefficients could be correctly estimated only in a very low pressure range. However, for high pressures, the quasi-equilibrium assumption is not valid at the initial adsorption times, making the LDF model no more applicable for accurate determination of the average effective diffusivities. To our knowledge we present the first measurement of the adsorption kinetics of hydrogen in a hybrid carbon MOF composite material. Moreover, the adsorption performances reported in this work are the best ones achieved until now by MIL-101(Cr) doping using carbonaceous materials.     

Low-crosstalk penalty MZI space switch with a 0.64-mm phase shifterusing quantum-well electrorefraction

We investigate Mach-Zehnder interferometric (MZI) space switches with quantum-well phase shifters. We find that the minimum phase shifter length is limited by additional crosstalk due to electroabsorption-induced imbalance in the MZI. This criterion also provides an optimal detuning between the bandgap and the operating wavelength of the MZI. Finally, we present a novel MZI with an ultrashort 0.64-mm phase shifter     

Analysis of cyclitols in different Quercus species by gas chromatography–mass spectrometry

BACKGROUND: The carbohydrate profile of some woods used for aging wines and spirits has been recently studied using a pressurized liquid extraction method, the main differences found being related to cyclitol content. The aim of this study was to perform a detailed study of these compounds in woods of different Quercus species in order to identify two unknown compounds which appeared in the extracts and to verify whether the obtained profile was homogeneous for other Quercus species. RESULTS: Besides the known monosaccharides and five cyclitols previously described, three deoxy‐inositols (epi‐, vibo‐ and scyllo‐quercitol) were identified. The presence of these eight cyclitols was confirmed in all subgenera and species of Quercus analyzed, allowing a characteristic cyclitol profile. CONCLUSIONS: Three deoxy‐inositols (quercitols) have been identified in the carbohydrate profile of oak wood. All examined Quercus species displayed a common profile consisting of four inositols and four quercitols, which represent a good dataset for characterization of this genus. Copyright © 2010 Society of Chemical Industry     

New Applications of Electrochemically Produced Porous Semiconductors and Nanowire Arrays

The growing demand for electro mobility together with advancing concepts for renewable energy as primary power sources requires sophisticated methods of energy storage. In this work, we present a Li ion battery based on Si nanowires, which can be produced reliable and cheaply and which shows superior properties, such as a largely increased capacity and cycle stability. Sophisticated methods based on electrochemical pore etching allow to produce optimized regular arrays of nanowires, which can be stabilized by intrinsic cross-links, which serve to avoid unwanted stiction effects and allow easy processing.     

Tape casting of nickel manganite NTC ceramics for chip thermistors

Tape casting is a reliable route for mass production of precise miniature NTC chip sensors. The present paper describes the development work in tape casting of nickel manganite based NTC formulations. The most suitable dispersion condition of the powder in MEK–ethanol solvent system was determined by rheological and sedimentation studies. The optimized slurry composition for obtaining defect-free tapes was achieved by controlling the amounts of organic additives. The sintered chip samples exhibited 98% theoretical density with an over all shrinkage of 17%.     

Resistance to HIV protease inhibitors: a comparison of enzyme inhibition and antiviral potency

Resistance of HIV-1 to protease inhibitors has been associated with changes at residues Val82 and Ile84 of HIV-1 protease (HIV PR). Using both an enzyme assay with a peptide substrate and a cell-based infectivity assay, we examined the correlation between the inhibition constants for enzyme activity (Ki values) and viral replication (IC90 values) for 5 active site mutants and 19 protease inhibitors. Four of the five mutations studied (V82F, V82A, I84V, and V82F/I84V) had been identified as conferring resistance during in vitro selection using a protease inhibitor. The mutant protease genes were expressed in Escherichia coli for preparation of enzyme, and inserted into the HXB2 strain of HIV for test of antiviral activity. The inhibitors included saquinavir, indinavir, nelfinavir, 141W94, ritonavir (all in clinical use), and 14 cyclic ureas with a constant core structure and varying P2, P2' and P3, P3' groups. The single mutations V82F and I84V caused changes with various inhibitors ranging from 0.3- to 86-fold in Ki and from 0.1- to 11-fold in IC90. Much larger changes compared to wild type were observed for the double mutation V82F/I84V both for Ki (10-2000-fold) and for IC90 (0.7-377-fold). However, there were low correlations (r2 = 0.017-0.53) between the mutant/wild-type ratio of Ki values (enzyme resistance) and the mutant/wild-type ratio of viral IC90 values (antiviral resistance) for each of the HIV proteases and the viruses containing the identical enzyme. Assessing enzyme resistance by "vitality values", which adjust the Ki values with the catalytic efficiencies (kcat/Km), caused no significant improvement in the correlation with antiviral resistance. Therefore, our data suggest that measurements of enzyme inhibition with mutant proteases may be poorly predictive of the antiviral effect in resistant viruses even when mutations are restricted to the protease gene.     

Novel methods for the quantification of changes in actin organization in chondrocytes using fluorescent imaging and linear profiling

We present three novel reproducible methodologies for the quantification of changes in actin organization from microscope images. Striation and integrative analysis were devised for the investigation of trans-cellular filaments and F-actin localization, respectively, in response to physiological or mechanical actin-modulatory conditions. Additionally, the Parker-Qusous (PQ) formula was developed as a measure of total quantity of F-actin, independent of cell volume changes, whereby fluorescence intensity was divided by the cube root of cell volume, squared. Values obtained were quantified in Mauricean Units (Mu; pixel/μm(3)). Upon isolation, there was a 49% decrease in total F-actin fluorescence from 1.91 ± 0.16 pixel/μm(3) (Mu) to 0.95 ± 0.55 Mu, whereas upon culture, an apparent increase in total fluorescence was deemed insignificant due to an increase in average cell volume, with a rise, however, in striation units (StU) from 1 ± 1 to 5 ± 1 StU/cell, and a decrease in percentage cortical fluorescence to 30.45% ± 1.52% (P = 7.8 × 10(-5)). Freshly isolated chondrocytes exhibited a decrease in total F-actin fluorescence to 0.61 ± 0.05 Mu and 0.32 ± 0.02 Mu, 10 min posthypertonic and hypotonic challenges, respectively. Regulatory volume decrease was inhibited in the presence of REV5901 with maintenance of actin levels at 1.15 Mu. Following mechanical impact in situ, there was a reduction in total F-actin fluorescence to 0.95 ± 0.08 Mu and 0.74 ± 0.06 Mu under isotonic and hypotonic conditions, respectively, but not under hypertonic conditions. We report simple methodologies for quantification of changes in actin organization, which will further our understanding of the role of actin in various cellular stress responses. These techniques can be applied to better quantify changes in localization of various proteins using fluorescent labeling.