Interdisciplinary Engineering

This work involves the determination of transport coefficients and equation of state of supercritical fluids by molecular dynamics (MD) simulations on parallel computers using the Green-Kubo formulae and the virial equation of state, respectively. The MD program uses an effective Lennard-Jones potential, linked cell lists for efficient sorting of molecules, periodic boundary conditions, and a modified velocity Verlet algorithm for particle displacement. Previously, simulations had been carried out on pure argon, nitrogen and oxygen, and this has now been extended to ethylene, C^H^, at various supercritical conditions, with shear viscosity and thermal conductivity coefficients, and pressures computed for most of the conditions. The results compare well with experimental and National Institute of Standards and Technology (NIST) values.

Industrial port cities are essential components in a society dependant on fossil fuels and low cost energy. In the global move towards a low-carbon society, industrial port cities are emblematic of complex and integrated socio-ecological systems, which are experiencing transition processes related to interactions between bio-geo-physical components and governance. Using a socio-ecological system framework, this article provides insights into innovative regional eco-industrial development strategies for moving toward a low-carbon future in industrial port areas. Based on three case studies (Marseille-Fos in France, Ningbo in China, and Ulsan in South Korea), our analysis focuses on the changing relationships between energy, land cover, time use, and governance. The historical socio-ecological transition of industrial port cities is described as a stepwise process of spatial and functional disconnection/connection of port industrial complexes, which decouple/combine the port city's metabolism from local resources. We highlight the impacts of globalization on port-city socio-ecological trends, describing the effects of the integration of port cities into global economic processes, the impact of global awareness on global environmental changes, and the accelerating pace of change. We compare low-carbon strategies, revealing similarities in terms of conversion toward low carbon sources and growing connectedness and functional diversity of port-industrial systems.

This research presents a new intelligent fault diagnosis and condition monitoring system for classification of different conditions of mechanical equipment that produces distinct thermal signatures for different fault conditions. This will be illustrated by considering the classification of six types of cooling radiator conditions: radiator tubes blockage, radiator fins blockage, loose connection between fins and tubes, radiator door failure, coolant leakage, and normal conditions. The proposed system consists of several distinct procedures including thermal image acquisition, image preprocessing, image processing, twodimensional discrete wavelet transform (2D-DWT), feature extraction, feature selection using a genetic algorithm (GA), and finally classification by artificial neural networks (ANNs). The 2D-DWT is implemented to decompose the thermal images. Subsequently, statistical texture features are extracted from the original images and are decomposed into thermal images. The significant selected features are used to enhance the performance of the designed ANN classifier for the 6 types of cooling radiator conditions (output layer) in the next stage. For the tested system, the input layer consisted of 16 neurons based on the feature selection operation. The best performance of ANN was obtained with a 16-6-6 topology. The classification results demonstrated that this system can be employed satisfactorily as an intelligent condition monitoring and fault diagnosis for a class of cooling radiator.

The objective of this paper is to model and optimise solar organic rankine cycle (ORC) engines for reverse osmosis (RO) desalination using currently available solar thermal collectors. The proposed systems are intended to be potentially attractive for remote areas without (or with very high cost) access to the public electricity grid.

A model for predicting the refractive index of sodium iodide (NaI) aqueous solution n N I as a function of temperature T, NaI concentration c and wavelength was determined for moderate parameter variations. The equation accurately predicted the salt concentration required to match n N I to the refractive index of Pyrex n P .

Recent International Maritime Organization (IMO) decisions with respect to measures to reduce the emissions from maritime greenhouse gases (GHGs) suggest that the collaboration of all major stakeholders of shipbuilding and ship operations is required to address this complex techno-economical and highly political problem efficiently. This calls eventually for the development of proper design, operational knowledge, and assessment tools for the energy-efficient design and operation of ships, as suggested by the Second IMO GHG Study (2009). This type of coordination of the efforts of many maritime stakeholders, with often conflicting professional interests but ultimately commonly aiming at optimal ship design and operation solutions, has been addressed within a methodology developed in the EU-funded Logistics-Based (LOGBASED) Design Project (2004)(2005)(2006)(2007). Based on the knowledge base developed within this project, a new parametric design software tool (PDT) has been developed by the National Technical University of Athens, Ship Design Laboratory (NTUA-SDL), for implementing an energy efficiency design and management procedure. The PDT is an integral part of an earlier developed holistic ship design optimization approach by NTUA-SDL that addresses the multi-objective ship design optimization problem. It provides Pareto-optimum solutions and a complete mapping of the design space in a comprehensive way for the final assessment and decision by all the involved stakeholders. The application of the tool to the design of a large oil tanker and alternatively to container ships is elaborated in the presented paper.

Several global corporations have been severely criticized by different lobbying groups for the impact of their operations on the natural environment and on the local communities. Because corporate operations cannot be studied in isolation but rather as a part of a large network often referred to as a supply chain, this paper investigates the potential link between supply chain characteristics and sustainable development at the country level. In particular, the linkage between supply chain strength, generally defined as the number and quality of the suppliers and customers in a country, and the three dimensions of sustainable development namely environmental performance, corporate environmental practices, and social sustainability is assessed. Using archival data from The Global Competitiveness Report (2004)(2005) and the 2005 Environmental Sustainability Index, a statistical assessment of the linkage was conducted.

Digital image correlation (DIC) is assessed as a tool for measuring strains with high spatial resolution in woven-fiber ceramic matrix composites. Using results of mechanical tests on aluminum alloy specimens in various geometric configurations, guidelines are provided for selecting DIC test parameters to maximize the extent of correlation and to minimize errors in displacements and strains. The latter error is shown to be exacerbated by the presence of strain gradients. In a case study, the resulting guidelines are applied to the measurement of strain fields in a SiC/SiC composite comprising 2-D woven fiber. Sub-fiber tow resolution of strain and low strain error are achieved. The fiber weave architecture is seen to exert a significant influence over strain heterogeneity within the composite. Moreover, strain concentrations at tow crossovers lead to the formation of macroscopic cracks in adjacent longitudinal tows. Such cracks initially grow stably, subject to increasing app lied stress, but ultimately lead to composite rupture. Once cracking is evident, the composite response is couched in terms of displacements, since the computed strains lack physical meaning in the vicinity of cracks. DIC is used to identify the locations of these cracks (via displacement discontinuities) and to measure the crack opening displacement profiles as a function of applied stress.

Experiments studying cardiovascular geometries require a working fluid that matches the high index of refraction of glass and silicone, has a low viscosity, and is safe and inexpensive. A good candidate working fluid is diethyl phthalate (DEP), diluted with ethanol. Measurements were made of index of refraction and viscosity of varied dilutions at a range of temperatures, and empirical models are proposed. Material compatibility tests showed that only specific formulations of ABS, acrylic, vinyl and PVC are compatible. A silicone elastomer additionally tested negative for change in compliance with DEP exposure.

The results of a set of experiments that were designed to integrate current knowledge on the major constituents of sugarcane bagasse lignin, specifically p-coumaric, ferulic, syringic acids, and vanillin are presented. These aromatic compounds have well-known antioxidant power and they are very important for the food, pharmaceutical, and nutraceutical industries. Following a study on the effect of pH upon the spectra of these monomers and the determination of their pK a values, their self-association properties in ethanol as a solvent, particularly at concentrations < 10 -4 M were investigated using UV spectrophotometry and their K ass values were determined. The results collected allowed to better understand the chemistry of sugarcane lignin and provide a contribution to the possible exploitation of this abundant straw material for the recovery of fine chemicals.

Perforated plates are widely used in pipeline systems either to reduce flow nonuniformities or to attenuate the onset and the development of cavitation. This experimental work aims at investigating the dependence of the pressure losses through sharp-edged perforated plates with respect to the geometrical and flow key parameters. The data, collected in two large experimental campaigns carried out on different pilot plants, are reported and discussed. Several plates with different geometrical characteristics were tested. More precisely, perforated plates whose equivalent diameter ratio varies between 0.20 and 0.72; relative hole thickness between 0.20 and 1.44; and number of holes between 3 and 52. Experimental data from literature are also considered in order to ensure the reliability of the parametric investigation. The dependence of the pressure loss coefficient upon the Reynolds number, the equivalent diameter ratio, the relative thickness, and the number and disposition of the holes is studied. A comparison to different empirical equations, as available by the technical literature, and to the standard ISO 5167-2 single-hole orifice is also provided.

This paper presents the results of ground vibration measurements carried out in Hisarcik Boron open pit mine located on the west side of central Anatolia near Kütahya province in Turkey. Within the scope of this study to predict peak particle velocity (PPV) level for this site, ground vibration components were measured for 304 shots during bench blasting. In blasting operations, ANFO (blasting agent), gelatin dynamite (priming), and delay electric detonators (firing) were used as explosives. Parameters of scaled distance (charge quantity per delay and the distance between the source and the station) were recorded carefully and the ground vibration components were measured for all blast events using two different types of vibration monitors (one White Mini-Seis and one Instantel Minimate Plus Model). The absolute distances between shot points and monitor stations were determined using GPS. The equation of square root scaled distance extensively used in the literature was taken into consideration for the prediction of PPV. Then, the data pairs of scaled distance and particle velocity obtained from the 565 event records were analyzed statistically. At the end of statistical evaluation of the data pairs, an empirical relation which gives 50% prediction line with a reasonable correlation coefficient was established between PPV and scaled distance.

Bio-ethanol, as a clean and renewable fuel, is gaining increasing attention, mostly through its major environmental benefits. It can be produced from different kinds of renewable feedstock such as e.g. sugar cane, corn, wheat, cassava (first generation), cellulose biomass (second generation) and algal biomass (third generation). The conversion pathways for the production of bio-ethanol from disaccharides, from starches, and from lignocellulosic biomass are examined. The common processing routes are described, with their mass and energy balances, and assessed by comparing field data and simulations. Improvements through 5 possible interventions are discussed, being (i) an integrated energy-pinch of condensers and reboilers in the bio-ethanol distillation train; (ii) the use of Very High Gravity (VHG) fermentation; (iii) the current development of hybrid processes using pervaporation membranes; (iv) the substitution of current ethanol dewatering processes to >99.5 wt% pure ethanol by membrane technology; and (v) additional developments to improve the plant operation such as the use of microfiltration of the fermenter broth to protect heat exchangers and distillation columns against fouling, or novel distillation concepts.

Rheological techniques are used to investigate the rejuvenation of aged bitumen. The thermal transition associated with the collapse of the compact structure constituted by asphaltene is determined by Dynamic Mechanical Thermal Analysis. For aged bitumen, this transition shifts to a higher temperature but when rejuvenating agents are added, the transition returns to its original value. The “rutting factor,” G*/sin δ allows to define the maximum temperature the binder can reach without permanent deformation. The employed rejuvenating agents are suitable because permanent deformation is postponed. Viscosity results reveal that aged bitumen needs a high mixing temperature (>200°C) to behave like a fluid material able to wet, adhere, and envelop aggregates. The addition of rejuvenating agents considerably reduces mixing and compaction temperatures. The mixture of 80% aged bitumen—20% recycled motor oil, obtained exclusively from waste materials is an apt binder that can compete satisfactorily with new 60/70 bitumen.

This article discusses the development, state-of-the-art and applications of exergy analysis and thermoeconomics (exergoeconomics). The latter is a relatively new method that combines exergy with conventional concepts from engineering economics to evaluate and optimize the design and performance of energy systems. This paper is written mainly for the person interested in applying tbermoeconomics to an energy system. It reviews the history of exergy analysis and thermoeconomics, the performance evaluation of an energy system from the viewpoints of the second law of thermodynamics and thermoeconomics as well as applications of thermoeconomic optimization techniques.

In this study a theoretical formulation for Poisson's ratio effects on tensile and compressive shaft capacity of driven piles in sand is developed. The theoretical formulation, which accounts for the existence of post-driving residual loads, is formulated based on a simple model for the pile-soil interface after pile installation and before pile axial loading. A computer program is written to facilitate the use of the theoretical formulation. The developed formulation shows that there is basis for consistent differences in tensile and compressive shaft capacity of driven piles in sand. Quantification of these differences has been made through numerical analysis and, parametric study has been also conducted to delineate all significant factors affecting the ratio of tensile to compressive shaft capacity of driven piles in sand.

The concurrent use of karst aquifers as drinking water resources and receptors of combined sewer overflow lacking appropriate pre-treatment may cause conflicts between drinking water supply and storm water management. A storm water tank (SWT) for combined wastewater is identified as the source of sporadic contamination of a karst spring (Gallusquelle, ''Schwäbische Alb'', SW Germany) used for public water supply. Spring water quality was examined by routine and event sampling and by evaluating physicochemical and microbiological parameters. The total number of microbial colonies growing at 20°C and the number of Escherichia coli colonies rose to values up to four orders of magnitude higher than background, 2-5 days after overflow of the SWT. High concentrations of chloride, sodium, and total organic carbon (TOC) and high values of turbidity coincide with this increase. However, high bacterial contamination is also observed while turbidity and TOC are low. Several wastewater-related organic micro-pollutants such as chlorinated and non-chlorinated organophosphates were detected in the SWT and, depending on their K ow values and their biodegradability, in lower concentrations at the spring.

The thermal hydraulic system code MERSAT has been applied to model the Brazilian IEA-R1 research reactor. The developed MERSAT model consists of detailed description for the primary loop including reactor core, bypass, reactor pool, main pump and coupling valve. The developed model is verified through the simulation of the steady state operation at the nominal power of 5 MW. According to the safety significance of postulated initiating events two selected design basis accidents corresponding to loss of flow accident (LOFA) with reactor scram and reactivity insertion accident (RIA) without scram have been analyzed. The results of LOFA simulation demonstrate the phenomena of flow reversal characterizing the flow turnaround from forced downward to natural upward circulation. The prevailing natural circulation after the flow reversal guarantees the removal of residual decay heat. The maximum clad temperature of the hot channel reaches its maximum of about 73°C after 35 s after the initiation of the transient. The step reactivity insertion of 2 mk leads to increasing the reactor power up to 1.7 times the nominal value. Consequently, the maximum clad temperature of hot channel reaches about 99°C which is still far below the onset of subcooled boiling. Hence, the established thermal hydraulic conditions ensure a considerable safety margin even if the reactor protection system should fail to shutdown the reactor 400 s after the begin of the reactivity insertion event. The results of LOFA and RIA demonstrate the safety features of IEA-R1 under the investigated conditions. In both cases the thermal hydraulic design limits have not been exceeded. However, for the RIA case the maximum clad temperature exceeds the limit of 95°C being chosen as operation criteria for limiting corrosion on the surface of the fuel elements.

Stereo digital image correlation (StereoDIC) measurements of wrinkle shapes and surface deformations along with numerical simulation results of prepreg tapes steered along paths having different radii of curvature without adhesion to a Teflon-coated substrate are presented. Experiments are conducted at temperatures ranging from 25 to 350°C on thermoplastic prepreg tape (APC-2/AS4) having various widths. For the baseline studies at room temperature (25°C), finite element simulation results from the combined experimental-computational study show very good agreement for both the wrinkling mode shape and general trends in the surface strains. Measurements do indicate a sharp change in the longitudinal and transverse strains for the two smallest steering radii, indicating the development of mesoscale damage in the prepreg. Finally, results from the experiments confirm that there is no significant deviation in the deformation response of the prepreg tape when performing steering at temperatures from 25 to 110°C. However, significant differences in the deformation pattern of the thermoplastic tape are observed above the glass transition temperature, T g , of the matrix material.

The evolution of technology has generated a greater competitive rivalry among Internet service providers, therefore, the goal was to design a wireless network to provide Internet service to rural areas of Valle de los Chillos and accessible prices , under the Wireless last mile access topology. The documentary methodology was applied to carry out the market, technical and economic study of the proposal, whose results showed that the projection of the demand with real data, under the interpolation of a logarithmic function, resulted in a considerable number of users, being the main characteristic of MIMO, the Three-Stream that uses three flows of spatial beams to increase in a remarkable way the wireless speed. Also very important is the channel width, normally 20 MHz, but 802.11n allows 40 MHz channel widths using two separate 20 MHz channels to increase the minimum transfer speed 177.5 Mbps, requiring MIMO with 2 channels of 20 MHz each for Maximum speed of 300 MHz and 300 Mbps theoretical speed in WiFi-N must have at least MIMO 2T2R, 40 MHz channel width and two beams (two-stream), with 20MHz channel bandwidth, 2.4 GHz or 5GHz. In conclusion, the last mile access topology improves the connectivity of the proposed wireless network.

Since its initial development as a specialty technique for modeling neutron transport in fissile materials almost 80 years ago, the Monte Carlo method has since been deployed in almost every area of science and engineering, including radiative transfer. This paper reviews the history and progress in Monte Carlo methods for simulating radiative energy transfer, with emphasis on advances over the past 25 years. A short historical review that emphasizes the probabilistic foundations of the method, is followed by discussions of recent extensions and applications, including variance reduction techniques, high fidelity simulations in complex media, and a discussion of unresolved issues. The article concludes with an outlook for the method as impacted by advancements in algorithm development as well as massively parallel and quantum computing.

< The temperature difference on a heating wall between the inlet and outlet was reduced by a flow separation technique. < The pressured drop was reduced by a flow separation technique. < The single-and two-phase convection heat transfer coefficients were enhanced by a flow separation technique. < The enhancement mechanisms were studied.

The crosslinking of the unsaturated polyester was studied by using experiments and a model of the process. The kinetic parameters were calculated from the heat flux-time curves obtained by differential scanning calorimetry (DSC, Netzsch-Simultaneous Thermal Analyser DSC 200), working in DSC (dynamic) mode. The temperature-time histories were studied in plain sheet copper mould. The mathematical model was constructed by taking into account the heat transferred by conduction through the resin, as well as the kinetics of heat generated by the crosslinking reaction. The contributions to the rise in temperature from heat conduction and chemical reaction are different in different parts of the composite, and can explain the temperature-, or degree of crosslinking (DOC)time histories. By considering temperature-time histories developed within the sample, more extensive knowledge of the process can be obtained. The effect of the heat transfer by conduction through the composite as well as the internal heat generated by the cure reaction is clearly shown, despite the complexity of the process. Finally, good agreement between experimental data and predicted mathematical model of the crosslinking process in plane sheet mould was shown.

In the COVID-19 pandemic situation, the need to adopt cloud computing (CC) applications by education institutions, in general, and higher education (HE) institutions, in particular, has especially increased to engage students in an online mode and remotely carrying out research. The adoption of CC across various sectors, including HE, has been picking momentum in the developing countries in the last few years. In the Indian context, the CC adaptation in the HE sector (HES) remains a less thoroughly explored sector, and no comprehensive study is reported in the literature. Therefore, the aim of the present study is to overcome this research vacuum and examine the factors that impact the CC adoption (CCA) by HE institutions (HEIs) in India. The scope of the study is limited to public universities (PUs) in India. There are, in total, 465 Indian PUs and among these 304 PUs, (i.e., 65% PUs) are surveyed using questionnaire-based research. The study has put forth a novel integrated technology adoption framework consisting of the Technology Acceptance Model (TAM), Technology-Organization-Environment (TOE), and Diffusion of Innovation (DOI) in the context of the HES. This integrated TAM-TOE-DOI framework is utilized in the study to analyze eleven hypotheses concerning factors of CCA that have been tested using structural equation modelling (SEM) and confirmatory factor analysis (CFA). The findings reveal that competitive advantage (CA), technology compatibility (TC), technology readiness (TR), senior leadership support, security concerns, government support, and vendor support are the significant contributing factors of CCA by Indian PUs. The study contends that whereas the rest of the factors positively affect the PUs' intention towards CCA, security concerns are a significant reason for the reluctance of these universities against adopting CC. The findings demonstrated the application of an integrated TAM-TOE-DOI framework to assess determining factors of CCA in Indian PUs. Further, the study has given useful insights into the successful CCA by Indian PUs, which will facilitate eLearning and remote working during COVID-19 or similar outbreak.

The purpose is to propose an improved method for inverse boundary value problems. This method is presented on a model problem. It introduces a higher order problem. BEM numerical simulations highlight the efficiency, the improved accuracy, the robustness to noisy data of this new approach, as well as its ability to deblur noisy data. Keywords Cauchy problem • inverse problem • boundary values • boundary element method • regularization

Flow patterns and mass transfer rates in a periodically grooved channel were studied in the transitional flow regime. Self-sustained flow oscillations occur at a low Reynolds number. Primary flow instability arises from TollmienSchlichting waves triggered by a shear layer above the groove, and thus there is a fluid exchange between channel and groove parts through the shear layer. It is found that a further increase of the Reynolds number produces secondary instability causing a three-dimensional flow at the bottom of the groove. Mass transfer was performed by the electrochemical method. The transport rate at the rib increases significantly after the primary instability, but the increment of mass transfer at the bottom of the groove is small. The secondary instability leads to marked transport enhancement at the bottom of the groove. ©1998

In the context of an increasing commitment to water efficiency in the EU policy, a different approach for eco-efficiency assessment in the agricultural sector, at the meso level, was applied to the Monte Novo irrigation perimeter, located in the southern region of Portugal, targeting the new agricultural paradigm being implemented in the Alentejo region, focusing on the assessment of the environmental and economic impacts and the eco-efficiency performance associated with the water value chain for both the baseline scenario and a set of potential eco-efficiency agricultural improvements. These improvements would be resource efficient or pollution preventing. The agricultural eco-efficiency improvements which promote the efficiency of water use, like the Regulated Deficit Irrigation, allow the reduction of water and energy consumptions, whereas those promoting pollution prevention as the use of sludge from waste water treatment plants or the use of organic fertilizers, make it possible to reduce pollution caused by the use of chemical fertilizers. The selection of the agricultural eco-efficiency improvements to be tested was based on stakeholders' involvement and perceptions; the chosen methodology highlights the impacts of the application of each of those eco-efficiency improvements and the potential investments required, in order to facilitate stakeholders' decisions. The results to be presented focus on the relative performance of the scenarios corresponding to the application of each of the proposed eco-efficiency improvements compared to a baseline scenario. The set of eco-efficiency indicators evaluated is complemented with an economic performance assessment, allowing to present some policy recommendations on technology uptake.

This paper summarizes several flow measurement systems qualified in the operation of different lead-bismuth loops in the KArslruhe Liquid Metal LAboratory (KALLA) during the last 5 years. There are several experimental techniques which were well proven in air and water and thus could be transferred similarly to liquid metals: these techniques are split into measuring local quantities as temperature, pressure e.g. by means of pressure taps or velocities using Pitot and Prandtl tubes or the Ultrasound Doppler velocimetry (UDV) for local flow velocities, as well as an integral quantity like the flow rate. Since the knowledge of the flow rate acts in terms of the operational safety of nuclear liquid metal systems as one of the most crucial parameters, this aspect is discussed widely herein. Unfortunately, as liquid metals are opaque, an optical access is not possible. Instead, one can take advantage of the high electric conductivity of liquid metals to measure integral and local quantities, like electromagnetic flow meters and miniaturised permanent magnetic probes for local velocity measurements. In this context especially the electromagnetic frequency flow meter (EMFM) is discussed as a prospective and reliable option to measure the flow rate without demanding extensive precognitions with respect to the fluid-wall interface behaviour. This article describes some of the techniques used in KALLA for different liquid metals, explains the measurement principle and shows some of the typical results obtained using these techniques. Also the measurement accuracy as well as the temporal and spatial resolution of each device is discussed and typical error sources to be expected are illuminated. Moreover, some hints for a correct placement of the individual sensor in the liquid metal environment are given.

At Centralised Waste Management Facility (CWMF) 160m3 of radioactive chemical sludge, generated from treatment of several batches of category-II and category-III radioactive liquid wastes by chemical precipitation method was stored in clariflocculator (CF) for downstream processing. The sludge needed conditioning before disposal. The analysis of the sludge samples collected at different radial locations and depths from the CF showed suspended

Laser ablation is investigated as a microsampling technique for determining the content and spatial distribution of hydrogen and deuterium in zirconium alloys. Zr-2.5wt%Nb (Zr-2.5Nb) material is ablated under vacuum with the 1.06 lm output of a Nd:YAG laser. Elemental H and D in the ablation plume are detected in a time-of-¯ight mass spectrometer (TOF-MS) following photo-ionization via the 1s±2s two-photon resonance near 243 nm. The laser/surface interaction is shown to be characterized accurately by a simple thermal model and the subsequent ablation is consistent with volume evaporation from the melted alloy. Elemental compositions in the ablation plume are found to represent those in the alloy. The analytical capabilities of laser ablation sampling are studied and discussed using various Zr-2.5Nb samples with known deuterium concentration gradients and bulk deuterium content. Crown Ó 1998 Published by Elsevier Science B.V.

The rapid development in the information technology field has introduced digital watermark technologies as a solution to prevent unauthorized copying and redistribution of data. This article introduces a self-embedded image verification and integrity scheme. The images are firstly split into dedicated segments of the same block sizes. Then, different Analytic Beta-Wavelet (ABW) orthogonal filters are utilized for embedding a self-segment watermark for image segment using a predefined method. ABW orthogonal filter coefficients are estimated to improve image reconstruction under different block sizes. We conduct a comparative study comparing the watermarked images using three kinds of ABW filters for block sizes 64 × 64, 128 × 128, and 256 × 256. We embed the watermark using the ABW-based image watermarking method in the 2-level middle frequency sub-bands of the ABW digital image coefficients. The imperceptibility and robustness of the ABW-based image watermarking method image is evaluated based on the Peak Signal to Noise Ratio (PSNR) and Correlation coefficient values. From the implementation results, we came to know that this ABW-based image watermarking method can withstand many image manipulations compared to other existing methods.

The simulation of nuclear power plant accident conditions requires three-dimensional (3D) modeling of the reactor core to ensure a realistic description of physical phenomena. The operational flexibility of Light Water Reactor (LWR) plants can be improved by utilizing accurate 3D coupled neutronics/thermal-hydraulics calculations for safety margins evaluations. There are certain requirements to the coupling of thermal-hydraulic system codes and neutron-kinetics codes that ought to be considered. The objective of these requirements is to provide accurate solutions in a reasonable amount of CPU time in coupled simulations of detailed operational transient and accident scenarios. These requirements are met by the development and implementation of six basic components of the coupling methodologies: ways of coupling (internal or external coupling); coupling approach (integration algorithm or parallel processing); spatial mesh overlays; coupled time-step algorithms; coupling numerics (explicit, semi-implicit and implicit schemes); and coupled convergence schemes. These principles of the coupled simulations are discussed in details along with the scientific issues associated with the development of appropriate neutron cross-section libraries for coupled code transient modeling. The current trends in LWR nuclear power generation and regulation as well as the design of next generation LWR reactor concepts along with the continuing computer technology progress stimulate further development of these coupled code systems. These efforts have been focused towards extending the analysis capabilities as well as refining the scale and level of detail of the coupling. This article analyses the coupled phenomena and modeling challenges on both global (assembly-wise) and local (pin-wise) levels. The issues related to the consistent qualification of coupled code systems as well as their application to different types of LWR transients are presented. Finally, the advances in numerical and computation techniques for coupled code simulations are summarized with outlining remaining challenges.

Impacts of irrigation with treated wastewater effluents on soils and groundwater aquifer in the vicinity of Sidi Abid Region (Tunisia) are evaluated. The groundwater aquifer was monitored by several piezometers, where monthly water levels were registered and groundwater salinity was evaluated. This resulted in characterizing the spatial and temporal evolution of the hydrochemical and hydrodynamic properties of the aquifer, showing thereby the impact of artificial recharge. Piezometric maps for prerecharge and post-recharge situations were developed and a comparison study of both piezometric situations was considered. The piezometric evolution map showed a generalized rise of the piezometric level in the vicinity of the irrigation zone. The extent of recharge was shown to increase with time as the groundwater level increase, which was localized in the vicinity of the irrigation area, reached more extended zones. Several groundwater samples were withdrawn from wells and piezometers and analyzed. Examining the corresponding physical and chemical parameters showed an increase in the concentrations of nutrients (28 mg/l for NO 3 and 3.97 mg/l for NH 4) in the groundwater aquifer below the irrigation zone, which confirms again the infiltration of treated wastewater effluents. The evolution of soil salinity was examined through chemical analysis of soil samples. Electric conductivities of soils were generally shown to be less than 4 mS/cm while the irrigation water has an electric conductivity that may reach 6.63 mS/cm. This might be explained by the phenomenon of dilution and the capacity of soils to evacuate salts downward.

The behavior of two spherical bubbles with different sizes near a solid wall is investigated in consideration of the effects of the vapor and noncondensable gas in the bubbles, and then the equations of motion of the bubbles are derived. Further, the effects of a solid wall on the variation with time of the bubble radius and the pressure at bubble wall are clarified by numerical calculations.