Substitution of Aggregates in Concrete and Mortar with Coltan Mining Waste: Mechanical, Environmental, and Economic Impact Case Study

The mining process involves drilling and excavation, resulting in the production of waste rock and tailings. The waste materials are then removed and stored in designated areas. This study aims to evaluate the mechanical strength and the environmental and economic impact of using Coltan Mining Waste (CMW) as a substitute for aggregates in concrete and mortar production. To achieve this, the CMW needs to be characterised. The Dreux Gorisse method was primarily used to produce concrete with a strength of 20 MPa at 28 days. The mortars, on the other hand, were formulated according to the NF P 18-452 standard. The environmental impact of using CMW as substitutes for natural aggregates in the production of concrete and mortar was analysed using SimaPro software. The results showed that mortars and concrete made with CMW have comparable compressive strengths to the reference mortar and concrete;reduce the negative impact on ecosystem quality, human health, resources, and climate change. It has also been shown that the substitution of aggregates by CMW reduces the cost of concrete and mortar as a function of the distance from the aggregate footprint.

A Cryptographic-Based Approach for Electricity Theft Detection in Smart Grid

In order to strengthen their security issues,electrical companies devote particular efforts to developing and enhancing their fraud detection techniques that cope with the information and communication technologies integration in smart grid fields.Having been treated earlier by several researchers,various detection schemes adapted from attack models that benefit from the smart grid topologies weaknesses,aiming primarily to the identification of suspicious incoming hazards.Wireless meshes have been extensively used in smart grid communication architectures due to their facility,lightness of conception and low cost installation;however,the communicated packets are still exposed to be intercepted maliciously in order either to falsify pertinent information like the smart meter readings,or to inject false data instead,aiming at electricity theft during the communication phase.For this reason,this paper initiates a novel method based on RSA cryptographic algorithm to detect electricity fraud in smart grid.This new method consists of generating two different cryptograms of one electricity measurement before sending,after which the recipient is used to find the same value after decrypting the two cyphers in a normal case.Otherwise,a fraudulent manipulation could occur during the transmission stage.The presented method allows us to kill two birds with one stone.First,satisfactory outcomes are shown:the algorithm accuracy reaches 100%,from one hand,and the privacy is protected thanks to the cryptology concept on the other hand.

Recognition of Offline Handwritten Arabic Words Using a Few Structural Features

Handwriting recognition is one of the most significant problems in pattern recognition,many studies have been proposed to improve this recognition of handwritten text for different languages.Yet,Fewer studies have been done for the Arabic language and the processing of its texts remains a particularly distinctive problem due to the variability of writing styles and the nature of Arabic scripts compared to other scripts.The present paper suggests a feature extraction technique for offlineArabic handwriting recognition.A handwriting recognition system for Arabic words using a few important structural features and based on a Radial Basis Function(RBF)neural networks is proposed.The methods of feature extraction are central to achieve high recognition performance.The proposed methodology relies on a feature extraction technique based on many structural characteristics extracted from the word skeleton(subwords,diacritics,loops,ascenders,and descenders).In order to reach our purpose,we built our own word database and the proposed system has been successfully tested on a handwriting database of Algerian city names(wilayas).Finally,a simple classifier based on the radial basis function neural network is presented to recognize certain words to verify the reliability of the proposed feature extraction.The experiments on some images of the benchmark IFN/ENIT database show that the proposed system improves recognition and the results obtained are indicative of the efficiency of our technique.

Model Identification and Control of Evapotranspiration for Irrigation Water Optimization

Water conservation starts from rationalizing irrigation,as it is the largest consumer of this vital source.Following the critical and urgent nature of this issue,several works have been proposed.The idea of most researchers is to develop irrigation management systems tomeet the water needs of plants with optimal use of this resource.In fact,irrigation water requirement is only the amount of water that must be applied to compensate the evapotranspiration loss.Penman-Monteith equation is the most common formula to evaluate reference evapotranspiration,but it requiresmany factors that cannot be available in many cases.This leads to a trend towards behavior model estimation.System identification with control is one of the most promising applications in this axis.The idea behind this proposal depends on three stages:First,the estimation of reference evapotranspiration(ET0)by a linear ARX model,where temperature,relative humidity,insolation duration and wind speed are used as inputs,and ET0 estimated by Penman-Monteith equation as output.The results show that the values estimated by thismethodwere in good agreement with the measured data.The second part of this paper is tomanage the quantity of water.For this purpose,two controllers are used for testing,lead-lag and PID.To adjust the first controller and optimize the choice of its parameters,Nelder-Mead algorithm is used.In the last part,a comparative study is done between the two used controllers.

Effect of an Inclined Slots on the Power Consumption and Vortices Size in a Rushton Turbine Agitated Tank

Mechanical agitation in baffled vessels with turbines plays a vital role in achieving homogeneous fluid mixing and promoting various transfer operations.Therefore,designing vessels with optimal energy efficiency and flow dynamics is essential to enhance operational performance and eliminate flow perturbations.Hence,the present research focuses on a numerical investigation of the impact of inclined slots with different angles installed at the side-wall of a cylindrical vessel equipped with a Rushton turbine.This study explores power consumption and vortex size while considering various rotation directions of the impeller with different rotation speeds.The numerical simulations are conducted for Reynolds numbers ranging from 104 to 105,using the RANS k-εturbulence model to govern the flow inside the stirred vessel,accounting for mass and momentum balances.The results have shown that the installation of slots reduces power consumption and vortex size compared to conventional vessel configu-rations.Moreover,increasing the slot angle from 0 to 32.5°further reduces energy consumption and vortex size,especially with negative rotation speeds.On the other hand,increasing the Reynolds numbers leads to a decrease in power consumption and an increase in vortex size.The present research therefore proposes a design for con-structing Rushton-turbine stirred vessels offering optimal operation,characterized by reduced energy consumption and minimized vortex size.

Evaluation Means Innovation in ELT:The Experience of the Algerian School

Evaluation is a natural activity that is not directly connected to teaching alone.It is a response to the emerging attitudes and understanding of others towards us.Evaluation has become an intrinsic part of the teaching/learning processes because it provides much information for management of the classroom practice,the planning of courses,and the handling of both the learning tasks and the students.Evaluation is a criterion to develop the level of proficiency of English language teaching(ELT).All the contributing items to the teaching/learning processes must be subjected to close scrutiny early.Therefore,evaluation as an overall system pilots the pool of items in education so as to arrive at a decision to what might be suitable or unsuitable for learners.This article is to explore the relationships between evaluation,innovation in the teaching/learning processes,as well as the evaluation areas of emphasis and some of the procedures that are used in ELT.The experience of the Algerian school is given as an example of necessity of evaluation to meet both the learners’needs and to respond to current requirements.