A digital twin model-based approach to cost optimization of residential community microgrids

This paper presents a peer-to-peer community cost optimization approach based on a single-prosumer energy management system.Its objective is to optimize energy costs for prosumers in the community by enhancing the consumption efficiency.This study was conducted along two main axes.The first axis focuses on designing a digital twin for a residential community microgrid platform.This phase involves data collection,cleaning,exploration,and interpretation.Moreover,it includes replicating the functionality of the real platform and validating the results.The second axis involves the development of a novel approach that incorporates two distinct prosumer behaviors within the same community microgrid,while maintaining the concept of peer-to-peer energy trading.Prosumers without storage utilize their individual PV systems to fulfill their energy requirements and inject excess energy into a local microgrid.Meanwhile,a single prosumer with a storage system actively engages in energy exchange to maximize the community’s profit.This is achieved by optimizing battery usage using a cost optimization solution.The proposed solution is validated using the developed digital twin.

A GIS-Based DRASTIC Model for Assessing Phreatic Aquifere of Bekalta (Tunisian Sahel)

The phreatic aquifer of Bekalta experienced a progressive degradation of water resources over time: using increasingly important waters for irrigation and drinking water, nitrate pollution, salinization... This aquifer is of great economic importance because it is used for irrigation and domestic consumption. Vulnerability map to nitrate pollution is a necessary tool to developing management to preserve the quality of groundwater. This study utilized the Geographic Information System technique and the DRASTIC model to assess the vulnerability of groundwater resources to contamination. The Geographic Information System (GIS) technology represents the best method to solve the main problems in the vulnerability survey. Indeed is allowed for swift organisation, quantification, and interpretation of large volumes of hydrological data with computer accuracy and minimal risk of human errors. The Visio model was exported and loaded into an ESRI Geodatabase in ArcCatalog as defined by the UML model. The purpose of this geodatabase is data harmonization process within modeling groundwater vulnerability to pollution. The resulting map shows evidence for three categories of vulnerability (low, middle and high). The resultant vulnerability map showed the predominant of moderately vulnerability class on the most of the Bekalta region which occupying an area of 68%. The low and high groundwater vulnerability classes occupy respectively an area of 30% and 2% of the total surface of the study area.

Effects of Drying on the Biochemical Composition of <i>Atherina boyeri</i>from the Tunisian Coast

The effects of solar and experimental drying on the protein concentration and total fatty acid (TFA) content of the muscles of Atherina boyeri (sand smelt) were studied. The percentage of protein was 18.3% for fresh fish and 14.2% for sun-dried fish, while TFA content was 4.9 g/100g and 0.5 g/100g. After the drying experiment, the percentage of protein was 23% and the fatty acid (FA) content was 2.8 g/100g. The results show that natural or experimental drying favors saturated fatty acids. The n-3 polyunsaturated fatty acids (PUFAs) are less sensitive to heat than the n-6 PUFAs. From a nutritional point of view, it seems that the drying conditions, where parameters are T = 50℃, moisture = 30% and air speed = 2 m/s, would be the most beneficial for the preservation of sand smelt.

The Influence of Environmental Factors on the Population Structure and Reproductive Biology of Idotea balthica basteri (Isopoda, Valvifera) of the Bizerte Lagoon (Northern Tunisia)

The reproductive biology of a natural population of Idotea balthica basteri (Pallas, 1772) collected from Menzel Jemil (Bizerte lagoon, Tunisia) was monthly studied from October 2009 to October 2010. Besides water temperature, salinity, turbidity, pH, and dissolved oxygen were measured. Based on the state of differentiation of individuals, the population was divided into 8 categories. Their numbers depend on the one hand to intrinsic factors imposed by the specimens and the structure of the population themselves, and to extrinsic factors due to the variability of environmental conditions on the other hand. Females were morphologically recognisable at smaller size than males. Reproductive activity, which was reflected through the presence of ovigerous females and juveniles, underwent fluctuations throughout the year, but it was continuous. Moreover, salinity, temperature, nitrates, and plant biomass have a noticeable effect on the fecundity and fertility. The Principal Component Analysis also confirmed that the richness of the water in nitrates would be favorable to fecundity and fertility of Idotea balthica basteri. However, higher phosphate concentrations, in April and May seem to have a positive effect on the sex ratio. Otherwise, the temperature would be responsible for increasing the percentage of ovigerous females.

Ion Exchange Equilibrium between DOWEX 1X8 Resin Modified by Polyethyleneimine and Electrolyte Solutions

In order to improve the selectivity of anion exchange resin, the surface of gel type anion exchange resin was modified with polyethyleneimine (PEI). In the proposed work an attempt to the utilization of commercial anion exchange resin modified by adsorption of polyethyleneimine was investigated. Many conditions of modification of anion exchange resin surface were studied. The influent parameters on the DOWEX 1X8 resin modification were determined using a factorial experimental design. The ion exchange reactions were studied for modified and unmodified resin and electrolyte solutions containing Cl-,NO3-,SO42-. All experiments were performed at constant ionic strength I = 0.3 mol·L-1 and constant temperature T = 298 K. Ionic exchange isotherms were established for the binary systems:Cl-/NO3-,Cl-/SO42- and NO3-/SO42-. The obtained results show that nitrate ion was more sorbed than chloride and sulfate. The order of preference for the anions studied in this investigation is:NO3->Cl->SO42-. All the results given by this resin were compared with those obtained with the AMX anion exchange membrane. Selectivity coefficients and thermodynamic constants for the three binary systems and for the two resins were determined. The modified resin became more selective towards monovalent anions.

Boron Removal by Electrocoagulation Using Full Factorial Design

Saline waters treatment has become increasingly important for drinking water supply in a greater part of the world. However, some serious limitations had recently been discovered during water treatment, among them the boron problem seems to have a critical meaning. According to the WHO regulations (2011), the boron concentration should be reduced to less than 2.4 mg/L for drinking water. The purpose of this study is to investigate the feasibility of electrocoagulation (EC) as a pretreatment process to remove boron from saline waters. To optimize the experimental conditions of boron removal, the effects of some parameters were studied such as inter-electrode distance (die), electrode connection mode, (S/V) ratio, pHi and initial conductivity of the solution (σi). Subsequently, an experimental design methodology was implemented to evaluate statistically the most significant operating parameters. The effects of current density, EC time and initial boron concentration and their mutual interaction were investigated using 23 full factorial design. At optimal conditions, boron removal from synthetic aqueous solutions containing initial boron concentrations of 5 and 50 mg/L reached 81% and 79%, respectively. Applied to boron removal from seawater samples, EC reduces boron concentration to less to 2.4 mg/L with excessive energy consumption under optimal parameters.

Extinction Conditions from a One-Sided Competition Model with a Holling Type I Functional Response for the Sterile Insect Technique

The Sterile Insect Technique (SIT) is a powerful biological tool to control pest-populations. It could be integrated in management programmes of the Red Palm Weevil (RPW) Rhynchophorus ferrugineus Olivier. This pest threatens seriously date palms particularly in Saudi Arabia. As a matter of fact, the use of SIT has been very efficient in controlling RPW populations in coconut gardens in various countries. In this work, we outline the extinction conditions of a target wild-population using a one-sided competition model to describe its competition with released sterile insects. We employ a Holling type I functional response to describe the sterile-fertile one-sided competition and we consider two intra-specific competition sub-models, with and without Allee Effect, in modelling the growth of the wild-type population. We also study two manners of liberating sterile insects: single and periodic release strategies.

Pseudo-static stability analysis of rock slopes reinforced by passive bolts using the generalized Hoek-Brown criterion

The stability analysis of passive bolt-reinforced rock slopes under seismic loads is investigated within the framework of the kinematic approach of limit analysis theory.A pseudo-static method is adopted to account for the inertial forces induced in the rock mass by seismic events.The strength properties of the rock material are described by a modified Hoek-Brown strength criterion,whereas the passive bolts are modeled as bar-like inclusions that exhibit only resistance to tensile-compressive forces.Taking advantage of the ability to compute closed-form expressions for the support functions associated with the modified Hoek-Brown strength criterion,a rotational failure mechanism is implemented to derive rigorous lower bound estimates for the amount of reinforcement strength to prevent slope failure.The approach is then applied to investigating the effects of relevant geometry,strength and loading parameters in light of a preliminary parametric study.The accuracy of the approach is assessed by comparison of the lower bound estimates with finite element limit analysis solutions,thus emphasizing the ability of the approach to properly predict the stability conditions and to capture the essential features of deformation localization pattern.Finally,the extension of the approach to account for slipping at the interface between reinforcements and surrounding rock mass is outlined.

Adsorption of F^-, NO₃^-and SO₄^2-on AFN Anionic Membrane: Kinetics and Thermodynamics Studies

The sorption of and from aqueous solution on AFN membrane has been studied and the equilibrium isotherms determined. The experimental data have been analyzed using the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models at different temperatures varying from 283 to 313 K. The results were analyzed using three kinetic models, Lagergen first order, second order and the Elovich model. The obtained results show that the best-fit correlation of the experimental data was obtained using the second order model. Thermodynamic parameters for the adsorption system were determined at 283, 298 and 313 K.

REPRESENTATION OF GENERALIZED TRANSLATIONS OF THE PRODUCT OF TWO FUNCTIONS ON SIGNED HYPERGROUPS ON THE REAL LINE

In this paper, we consider the generalized translations associated with the Dunkl and the Jacobi-Dunkl differential-difference operators on the real line which provide the structure of signed hrpergroups on R. Especially, we study the representation of the gener- alized translations of the product of two functions for these signed hypergroups.

Calculation of Photo-Ionisation Cross Sections and Radiative Recombination Rate Coefficients for CO and CO^+ Molecules

A method based upon the weighted total cross section （WTCS） theory is proposed to calculate the photo-ionisation cross sections and the radiative recombination rate coefficients between the fundamental level of CO and the main electronic states of its corresponding ion. Total photo-ionisation cross sections and radiative recombination rate coefficients are determined from the calculation of elementary vibrational photo-ionisation cross sections. Transitions be- tween CO＋（X, A and B） and CO（X） are considered. Total photo-ionisation cross sections and recombination coefficients are computed in the temperature interval 500-15000 K.

Optimization of Chromium (Vi) Removal by Donnan Dialysis

The removal of chromium (VI) from aqueous solutions by Donnan dialysis has been investigated in this paper. In this process, two anion-exchange membranes (AEMs) were used: Selemion? AMV and Neosepta? AFN. The amount of chromium (VI) removed was determined in terms of the following parameters: initial concentration of chromium (VI), type of anion-exchange membrane, concentration of counter-ion and magnetic stirring rate. A 24 full factorial design analysis was performed to screen the parameters affecting the Cr (VI) removal efficiency. Using the experimental results, a linear mathematical model representing the influence of the different parameters as well as their interactions was obtained. Analysis of the variance (ANOVA), the F-test and the student’s test shows that the type of anion-exchange membrane is the most significant parameter affecting the chromium (VI) removal. The statistical analysis of the experimental data assumes it to be a normal distribution.

Application of Donnan Dialysis Coupled to Adsorption onto Activated Alumina for Chromium (VI) Removal

The aim of this paper is the assessment of Donnan dialysis coupled to adsorption process for the removal of chromium from aqueous solutions. This study was conducted in order to benefit from each process, and it was an original and new combination. The coupling was a solution to improve the contact time and the amount of chromium (VI) removed. The coupling was successfully performed with 90% of chromium (VI) removed after 6 hours.