The Hydrogenolysis of Commercial Corn Glucose Syrup

Hydrogenolysis of corn syrup was carried out at 170°C and 60 at pressure. After 3 h 92.3% of the glucose content of the syrup was converted into sorbitol.     

A Novel Graph-Based Approach for the Management of Health Data on Cloud-Based WSANs

Nowadays, healthcare applications become among the most important services that help to improve the public safety through, for example, the prevention of the propagation of some epidemic diseases from patient to another or better from a location to another. Wireless Body Area Networks (WBANs) are considered among the major sources that enable the collection of such kind of data that shares in most cases the properties of big data and that needs to be stored and managed in an efficient manner. Regarding this need, Wireless Storage Area Networks (WSANs) have been considered among the alternatives to store generated health data. Even if these infrastructures enable the storage of huge volumes of data, there are some issues related to the efficient storage and processing of health data that still not resolved and that are of interest for the research communities. In this context, this paper proposes a cloud-based WSAN approach that enables the storage and the management of health data in an efficient manner by representing the collected data and their dependencies using Temporal Conceptual Graphs (TCGs). The validity of the generated graphs is verified by the proposed graph checker that enables the localization of semantic errors in such structure to prevent some threats to be realized for stored health data and to ensure the privacy of patients. The efficiency of the proposed approach is illustrated for different defined scenarios of diseases and their associated health data represented through generated TCGs.     

Ambiguity attacks on SVD audio watermarking approach using chaotic encrypted images

In this paper, we study the robustness of the proposed watermarking algorithm by Al-Nuaimy et al. (Digit Signal Process 21(6):764–779 2011) for audio signals which is based on singular value decomposition (SVD). It has been concluded that it is fundamentally flawed in its design, in that it falls to two ambiguity attacks where the extracted watermark is not the embedded one but determined by the reference watermark. In the first attack, when a watermarked audio signal is rewatermarked by an attacker’s watermark, this one can be easily extracted to claim ownership of the original audio signal. In the second attack, during the extracting process when an attacker uses the singular vectors of his watermark, he can extract the attacker’s watermark. Therefore, he can claim ownership of the watermarked audio signal. The experimental results prove that the proposed attacks create a false positive detection in watermark extraction. Therefore, Al-Nuaimy et al. algorithm cannot be used for security systems, data hiding and copyright protection.

     

Infrared and electron spin resonance for the high temperature superconductor Y1Ba2Cu3O9−x

Samples of the high temperature superconductor Y-Ba-Cu-O were prepared to achieve the oxygen deficient perovskite structure Y₁Ba₂Cu₃O_9–x withx>2. The electrical resistance has been measured with the temperature in the range from 77 to 300 K, under the application of d.c. and a.c. with frequency 900 Hz. The d.c. produced a rather lower critical temperatureT _c with zero resistance at 77.1 K, but the a.c. gave a sharp drop in the resistance but zero resistance was reached at liquid nitrogen temperature. To elucidate this behaviour, an X-ray diffraction pattern was obtained. An infrared analysis was carried out for the sample and the starting materials to provide more information about the bonds. To complete the picture, electron spin resonance study is discussed. It is important to point out that this is the first time infrared measurements for superconductors have been carried out in Egypt.     

Multi-dimensional analysis of soil moisture dynamics in trickle irrigated fields. I: Mathematical modelling

An approach is presented to model soil moisture dynamics in irrigated fields. A generalised conceptual model is proposed for moisture transfer in response to hydraulic and thermal gradients. A model to stimulate moisture extraction by roots is presented, based on a philosophy related to fundamental physical principles and recent experimental evidence. The combined models are interpreted numerically by the finite element method and a number of numerical techniques are developed to treat time-dependent, nonlinear and moving boundary conditions. The approach is sufficiently general and is independent of the method of water application being considered. Its benefits are particularly magnified in studies of localised irrigation, where complex soil-water distribution patterns evolve.     

Modelling of the Influence of Micro‐Plasticity on the Magnetic Behaviour of Ferromagnetic Polycrystals through a Multiscale Approach

A drastic degradation of the magnetic behaviour of low carbon or silicon steels occurs with weak plastic deformations, associated with strong second order internal stresses. A micromechanical modelling of plasticity is linked to a multiscale modelling of the magnetic behaviour. Experimental results and modelled data are compared.     

Use of desiccant dehumidification to improve energy utilization in air-conditioning systems in Beirut

Humidity and indoor moist surrounding affect air cleanliness and protects harmful microorganisms when relative humidity is above 70%. In humid climates, the humidity issues are a major contributor to energy inefficiency in HVAC devices. The use of liquid desiccant dehumidification systems of supply air is a viable alternative to reduce the latent heat load on the HVAC system and improve efficiency. Thermal energy, at a temperature as low as 40–50°C, required for the operation of a liquid desiccant hybrid air conditioner can be efficiently obtained using a flat-plate solar collector. In this work a model of a solar-operated liquid desiccant system (using calcium Chloride) for air dehumidification is developed. The system utilizes packed beds of counter flow between an air stream and a solution of liquid desiccant for air dehumidification and solution regeneration. The desiccant system model is integrated with a solar heat source for performance evaluation at a wide range of recorded ambient conditions for Beirut city. Standard mass and energy balances are performed on the various components of the system and a computer simulation program is developed for the integrated system analysis. The desiccant system of the current study replaces a 3 TR (10.56 kW) vapour compression unit for a typical house as low latent load application, and is part of a hybrid desiccant–vapour compression system for a high latent load application, namely a small restaurant with an estimated cooling load of 11.39 TR (40 kW), including reheat. The relevant parameters of the desiccant system are optimized at peak load, and it is found out that there is an important energy saving if the ratio of the air flow rate in the regenerator to that in the dehumidifier is about 0.3 to 0.4. The COP of the desiccant unit is 0.41 for the house, and 0.45 for the restaurant. The size of the vapor compression unit of the restaurant is reduced to 8 TR when supplemented by a desiccant system. The performance is studied of the desiccant system integrated with a solar collector system and an auxiliary natural gas heater to heat the regenerator. The transient simulation of the solar desiccant system is performed for the entire cooling season. The solar fraction for the house is equal to 0.25, 0.47, and 0.68 for a collector area of 28.72, 57.44, and 86.16 m², respectively. The solar fraction for the restaurant is 0.19, 0.38, and 0.54, for the same collector areas. The life cycle savings for the house run solely on desiccant system were positive only if natural gas is available at a cheap price. For the restaurant, the economic benefit of the desiccant system is positive, because the need for reheat in the vapor compression system is eliminated. For a gas price of 0.5638 $/kg, the payback period for the restaurant turned out to be immediate if the energy is supplied solely by natural gas, and 11 years if an 86.16 m² solar collector is implemented to reduce the fuel consumption. Copyright © 2003 John Wiley & Sons, Ltd.     

Preparation of aerochitin‐TiO2 composite for efficient photocatalytic degradation of methylene blue

An aerochitin–titania (TiO₂) composite was successfully synthesized and characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, field emission scanning electron microscopy, and N₂ adsorption isotherms. The photocatalytic activity of the composite was investigated on the degradation of the model organic pollutant, methylene blue (MB) dye, under UV irradiation. The aerochitin–TiO₂ composite showed excellent adsorptive and photocatalytic activity with a degradation degree of 98% for MB. The first‐order rate constants for the photodegradation MB by TiO₂ nanoparticles and aerochitin–TiO₂ composite were found to be (3.49 ± 0.04) × 10^?3 and (1.82 ± 0.02) × 10^?2 min^?1. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45908.     

U2RV: UAV‐assisted reactive routing protocol for VANETs

When it comes to keeping the data routing robust and effective in vehicular ad hoc networks (VANETs), stable and durable connectivity constitutes the keystone to ensure successful point‐to‐point communication. Since VANETs can comprise all kinds of mobile vehicles moving and changing direction frequently, this may result in frequent link failures and network partitions. Moreover, when VANETs are deployed in a city environment, another problem arises, that is, the existing obstructions (eg, buildings, trees, and hoppers) preventing the line‐of‐sight between vehicles, thus degrading wireless transmissions. Therefore, it is more complicated to design a routing technique that adapts to frequent changes in the topology. In order to settle all these problems, in this work, we design a flooding scheme that automatically reacts at each topology variation while overcoming the present obstacles while exchanging data in ad hoc mode with drones that are commonly called unmanned aerial vehicles (UAVs). Also, the aim of this work is to explore well‐regulated routing paths providing a long lifetime connectivity based on the amount of traffic and the expiration time of each discovered path. A set of experiments is carried out using a simulation, and the outcomes are confronted with similar protocols based on a couple of metrics. The results clearly show that the assistance of UAVs to vehicles is capable of providing high delivery ratios and low delivery delays while efficiently extending the network connectivity.