Efficient audio integrity verification algorithm using discrete cosine transform

Audio recordings have been used as evidence for long times. Multimedia processing advancement makes it difficult to be completely sure about what is heard is the truth. This paper presents a promising approach for integrity verification of recorded audio signals using discrete cosine transform. This approach is based on self embedding concept which embeds block-based marks extracted from the same audio signal after being transformed into 2-D format into other blocks according to a specific algorithm. After the self-embedding process, the data is converted back into 1-D style which represents a marked audio signal. The 1-D audio signal is converted into a 2-D format and then converted back into a 1-D format using the popular lexicographic ordering scheme utilized in image processing. Reverse processes are executed to extract the verification marks from the audio signal throughout the integrity verification process. Based on the extracted audio signal properties, the integrity of the marked audio signal is evaluated. Different audio processing tasks and attacks are implemented to examine the suitability of the proposed algorithm for verifying the integrity of high-confidentiality recorded audio data. The results show that the efficient ability of the proposed approach to verify integrity and detect attacks.     

A Genetic Algorithm-Based,Dynamic Clustering Method Towards Improved WSN Longevity

The dynamic nature of wireless sensor networks (WSNs) and numerous possible cluster configurations make searching for an optimal network structure on-the-fly an open challenge. To address this problem, we propose a genetic algorithm-based, self-organizing network clustering (GASONeC) method that provides a framework to dynamically optimize wireless sensor node clusters. In GASONeC, the residual energy, the expected energy expenditure, the distance to the base station, and the number of nodes in the vicinity are employed in search for an optimal, dynamic network structure. Balancing these factors is the key of organizing nodes into appropriate clusters and designating a surrogate node as cluster head. Compared to the state-of-the-art methods, GASONeC greatly extends the network life and the improvement up to 43.44 %. The node density greatly affects the network longevity. Due to the increased distance between nodes, the network life is usually shortened. In addition, when the base station is placed far from the sensor field, it is preferred that more clusters are formed to conserve energy. The overall average time of GASONeC is 0.58 s with a standard deviation of 0.05.     

Uscharin,the most potent molluscicidal compound tested against land snails

Calotropis procera, is a shrub with broad ovate fleshy leaves that grows wild in the Egyptian deserts. The plant was discovered to be highly toxic to the land snailsThepa pisana. The active ingredient responsible for the molluscicidal activity was isolated from its latex by solvent extraction and partitioning and was finally purified by fractional crystallization from 95% aqueous ethanol. The purity of the isolated material was monitored by TLC. Chemical identification was carried out using mass, infrared, and proton magnetic resonance spectroscopic methods. The active compound was found to be uscharin, and its identity was confirmed by comparing its spectroscopic data with the literature values. The isolated compound was 128 times more toxic than methomyl to the snails tested.     

Enhancing corrosion resistance of aluminum composites in 3.5% NaCl using pigmented epoxy fluoropolymer

The corrosion protection performance of AA6061 T6–10% Al₂O₃ composite, coated with four different fluoropolymer paint systems, were investigated in 3.5% NaCl aqueous solutions under uniform and scratched conditions. A comparison between epoxy-treated clear and pigmented fluoropolymer coatings with newly developed vanadate-based fluoropolymer coatings was performed from corrosion protection, adhesion and durability points of view. The corrosion rates of epoxy-treated clear FLBZ 1074 increased dramatically after less than one month of exposure in 3.5% NaCl aqueous solutions. The addition of iron oxide or titanium oxide as pigments to the fluoropolymer decreased the porosity of epoxy and hence, improved the corrosion resistance. The newly developed vanadate based-clear FLBZ 1074 system showed outstanding corrosion resistance even after two months of immersion in 3.5% NaCl aqueous solutions under scratched coating conditions. The durability of such new coating based on salt spray test results was very promising (>2000 h without any sign of corrosion). The vanadate-pigmented FLBZ 1074 showed a dramatic increase in the corrosion rates. Moreover, the presence of pigments affected negatively the adhesion performance as well as the durability of the coating. A general model has been used to analyze the impedance data in terms of reactions occurring during the interaction of the coated metal with the environment. It was found that the vanadate-treated specimens not only improve the protective power against filiform corrosion as a factor of time, but also maintain the adhesion performance within the acceptable ranges.     

Spatiotemporal Visualizations for the Measurement of Oropharyngeal Transit Time From Videofluoroscopy

Videofluoroscopy remains one of the mainstay methods for clinical swallowing assessment, yet its interpretation is both complex and subjective. This, in part, reflects the difficulties associated with estimation of bolus transit time through the oral and pharyngeal regions by visual inspection, and problems with consistent repeatability. This paper introduces a software-only framework that automatically determines the time taken for the bolus to cross 1-D anatomical landmarks representing the oral and pharyngeal region boundaries ( Fig. 1). The user-steered delineation algorithm live-wire and straight-line annotators are used to demarcate the landmark on a frame prior to the swallow action. The rate of change of intensity of the pixels in each landmark is used as the detection feature for bolus presence that can be visualized on a spatiotemporal plot. Artifacts introduced by head and neck movement are removed by updating the landmark coordinates using affine parameters optimized by a genetic-algorithm-based registration method. Heuristics are applied to the spatiotemporal plot to identify the frames during which the bolus passes the landmark. Correlation coefficients between three observers visually inspecting twenty-four 5-mL single swallow clips did not exceed 0.42. Yet the same measurements taken using this framework on the same clips had correlation coefficients exceeding 0.87.      

The effect of alkaline etching time on the anticorrosion performance of vanadia film formed on high strength AA2024 in chloride media

Corrosion performance, morphology, and electrochemical characteristics of vanadia-based conversion coatings on high strength aluminum AA2024-T3 alloy were examined as a function of alkaline etching time prior to vanadia treatment. Corrosion resistance and coating performance improved after etching in an alkaline solution for 10 min followed by vanadia treatment at room temperature. Electrochemical impedance spectroscopy and polarization testing correlated to macro- and microscopic surface examination and visual inspection. Proper etching of aluminum AA2024-T3 panels in alkaline solution prior to vanadia coating is a time dependent and considers a critical step for improved coating performance and materials durability. Results showed that the optimum alkaline etching time prior to vanadia treatment was 10 min which offers the best resistance to localized corrosion attack in NaCl solution. Alkaline etching for 10 min has an important role in increasing the number of OH groups on the aluminum surface, contributing to the adhesion of the vanadia-rich aluminum oxide layer by promoting covalent bonding. Based on these results, processes active during alkaline etching are kinetically dependent and strongly influenced by etching time.     

Modeling the effect of cooling system on the shrinkage and temperature of the polymer by injection molding

Injection molding is one of the most exploited industrial processes in the production of plastic parts. Shrinkage behavior of a molded plastic part plays an important role in determining final dimensions of the part. In this paper, the effect of the cooling system on the shrinkage rate of a polystyrene product during injection molding is carried out. A compressible fluid model for the physical system is presented. A finite volume numerical solution is used for the solution of the physical model. A validation of the numerical model in case of square cavity filled with polymer material is presented. The compressibility behavior of polymer material observed by the pressure, volume, and temperature for the state equation (P–v–T equation) is represented by Tait's equation. A Cross type rheological model depending on the temperature and pressure is assumed for the polymer material. The studied configurations consist of a mold having T-shaped plastic part and four cooling channels. Different cooling channels' positions are assumed and the effect of their positions on the cooling process is studied. The results indicate a good agreement between the numerical solution and those of the literatures. They also, show that the position of the cooling channels has a great effect on final product temperature and the shrinkage rate distribution throughout the product.     

Pd-Doped Co3O4 Nanoarray for Efficient Eight-Electron Nitrate Electrocatalytic Reduction to Ammonia Synthesis

Ammonia (NH₃) is an indispensable feedstock for fertilizer production and one of the most ideal green hydrogen rich fuel. Electrochemical nitrate (NO₃⁻) reduction reaction (NO₃⁻RR) is being explored as a promising strategy for green to synthesize industrial-scale NH₃, which has nonetheless involved complex multi-reaction process. This work presents a Pd-doped Co₃O₄ nanoarray on titanium mesh (Pd-Co₃O₄/TM) electrode for highly efficient and selective electrocatalytic NO₃⁻RR to NH₃ at low onset potential. The well-designed Pd-Co₃O₄/TM delivers a large NH₃ yield of 745.6 µmol h⁻¹ cm⁻² and an extremely high Faradaic efficiency (FE) of 98.7% at −0.3 V with strong stability. These calculations further indicate that the doping Co₃O₄ with Pd improves the adsorption characteristic of Pd-Co₃O₄ and optimizes the free energies for intermediates, thereby facilitating the kinetics of the reaction. Furthermore, assembling this catalyst in a Zn-NO₃⁻ battery realizes a power density of 3.9 mW cm⁻² and an excellent FE of 98.8% for NH₃.     

Optimal Selection of Hybrid Renewable Energy System Using Multi-Criteria Decision-Making Algorithms

Several models of multi-criteria decision-making (MCDM) have identified the optimal alternative electrical energy sources to supply certain load in an isolated region in Al-Minya City, Egypt. The load demand consists of water pumping system with a water desalination unit. Various options containing three different power sources: only DG, PV-B system, and hybrid PV-DG-B, two different sizes of reverse osmosis (RO) units; RO-250 and RO-500, two strategies of energy management; load following (LF) and cycle charging (CC), and two sizes of DG; 5 and 10 kW were taken into account. Eight attributes, including operating cost, renewable fraction, initial cost, the cost of energy, excess energy, unmet load, breakeven grid extension distance, and the amount of CO₂, were used during the evaluation process. To estimate these parameters, HOMER^® software was employed to perform both the simulation and optimization process. Four different weight estimation methods were considered; no priority of criteria, based on a pairwise comparisons matrix of the criteria, CRITIC-method, and entropy-based method. The main findings (output results) confirmed that the optimal option for the case study was hybrid PV-DG-B with the following specification: 5 kW DG, RO-500, and load following control strategy. Under this condition, the annual operating cost and initial costs were $ 5546 and $ 161022, respectively, whereas the cost of energy was 0.077 $/kWh. The excess energy and unmet loads were 40998 and 2371 kWh, respectively. The breakeven grid extension distance and the amount of CO₂ were 3.31 km and 5171 kg per year, respectively. Compared with DG only, the amount of CO₂ has been sharply reduced by 113939 kg per year.     

Vitamin B12 buccoadhesive tablets: auspicious non-invasive substitute for intra muscular injection: formulation,in vitro and in vivo appraisal

Attempting to prepare a convenient bioavailable formulation of vitamin B₁₂ (cyanocobalamin), 17 tablet formulations were prepared by direct compression. Different concentrations of hydroxypropyl methyl cellulose (HPMC), carbopol 971p (CP971p), and chitosan (Cs) were used. The tablets were characterized for thickness, weight, drug content, hardness, friability, surface pH, in vitro drug release, and mucoadhesion. Kinetic analysis of the release data was conducted. Vitamin B₁₂ bioavailability from the optimized formulations was studied on rabbits by the aid of enzyme-linked immunosorbent assay. Neurotone^® I.M. injection was used for comparison. HPMC (F1-F4), CP971p (F5-F8), and HPMC/CP971p (F12-F15)-based formulations showed acceptable mechanical properties. The formulated tablets showed maximum swelling indices of 232?±?0.13. The surface pH values ranged from 5.3?±?0.03 to 6.6?±?0.02. Bioadhesive force ranged from 66?±?0.6 to 150?±?0.5?mN. Results showed that CP971p-based tablets had superior in vitro drug release, mechanical, and mucoadhesive properties. In vitro release date of selected formulations were fitted well to Peppas model. HPMC/CP971p-based formulations showed bioavailability up to 2.7-folds that of Neurotone^® I.M. injection.