Journal of Applied Engineering Science and Technology
The Journal of Applied Engineering Sciences & Technology, JAEST, (ISSN 2352-9873) is a peer-reviewed biannual journal published in both electronic and print versions by the Faculty of Sciences and Technology, University of Biskra, Algeria. The Journal of Applied Engineering Sciences Technology is an open-access journal. The journal doesn’t have any article processing charges (APCs) or submission charges. The journal is now indexed in Google Scholar, Indexa, and Crossref. The journal invites submissions in English that present novel findings not previously published in journals within the domains of engineering science research. Additionally, JAEST also curates special issues featuring outstanding papers chosen from diverse conferences in specific areas of applied engineering science and technology. Print ISSN: 2352-9873 Online ISSN: 2571-9815
Experimental implementation of an SRM control approach
This paper presents an improved current control strategy for a switched reluctance motor (SRM) drive. Owing to its doubly salient structure and nonlinear magnetic characteristics, the SRM exhibits strong coupling between current, flux, and torque, making accurate current regulation essential for achieving stable torque production and minimizing acoustic noise and ripple. The proposed controller is designed to enhance current tracking accuracy under fast dynamic conditions while preserving robustness against magnetic saturation, inverter delays, and load disturbances. Experimental validation is conducted on a fully instrumented SRM test bench using real-time acquisition hardware and a standard asymmetric bridge converter. The study demonstrates significant improvements in current tracking, torque quality, energy utilization, and global operational reliability when measured against earlier approaches in the literature. Highlights Significantly improved current-tracking performance with reduced dynamic error. Enhanced torque quality, including lower ripple and smoother torque production. Increased overall energy efficiency of the drive system. Improved operational reliability compared to conventional controllers reported in previous studies. The proposed solution outperforms existing methods in terms of accuracy, robustness, and overall performance.
Experimental Realization- Real-Time Implementation- Switched Reluctance Motor (SRM)- current control strategy
Copyright (c) 2025 Journal of Applied Engineering Science and Technology https://creativecommons.org/licenses/by-nc/4.0
Design and Deployment of a Low-Cost IoT-Based Air Quality Monitoring System Using ESP32, BME688, and MQ135 Sensors in Urban Lagos, Nigeria
This study presents the design, calibration, and in-field deployment of an IoT sensor network at a low cost for monitoring real-time urban air quality in Lagos, Nigeria, for diurnal and locational differences in Carbon-dioxide (CO₂), Nitrogen dioxide (NO₂), Methane (CH₄,) and weather parameters. The homemade system, constructed at ₦121,500, provides multi-gas and weather monitoring at 27–81% cheaper compared to mid- and high-end commercial sensors. Five hotspots with elevated risk—Oshosi, Iyana Ipaja, UNILAG dump site, Olusosun landfill, and Super Bus Stop—were assessed by morning (06:00–09:00) and evening (19:00–22:00) sessions. Nighttime levels of pollutants were always higher, with CO₂ highest at 790 ppm than the morning's 740 ppm, and CH₄ highest at 0.44 ppm ((Olusosun landfill). These increases were during times of elevated temperature (27.9-32.7 °C), humidity (68–79%) and lower atmospheric pressure (1003–1012 hPa), conditions that would have restricted vertical dispersion. High positive correlations (r ≥ 0.83, p < 0.05) existed between meteorological parameters (atmospheric pressure, relative humidity, and temperature) and the four detected pollutant concentrations (MQ135 index, NO₂, CO₂, and CH₄) during morning and nighttime sampling durations. The system maintained >95% uptime and gave data output within three seconds of data taking, and was therefore highly reliable and robust for tropical urban environments. This method offers an affordable, scalable model of continuous pollution monitoring and evidence-based urban environmental management for rapidly growing cities.
Study of the Hydrodynamic performance Membranes based on the Polysulfone and doped Polyanilibe : Conception and application
Polysulfone/polyaniline ultrafiltration ((PSF/PANI-UF) membranes were prepared via the phase inversion method using six examples of the polyaniline (PANI) synthesized in the presence of doped by functionalized agent dopants by direct process. To enhance the hydrodynamic performances of these prepared membranes, the conducting polyaniline (PANIs) has been added at different mass compositions (0.0, 0.2, 0.5 and 1.0%). The performance surface hydrophobicity was estimated by the contact angle. The PSF/PANI Membranes were characterized by FTIR spectroscopy in order to identify the interaction between PSF, PEG and PANI in presence of NMP solvent. The UV-Visible results of the PANIs pellets indicate that PANIs were obtained as emerald salt, which confirmed by calculating the oxidation state of PANIs from the FTR spectra. The separation properties of the composite membranes were studied in terms of water permeability and methylene blue removal. The porosity and the permeability of the membranes PFS/PANI were improved in comparison with that of the pristine PSF membrane as well as rejection capacities (>97%) for methylene blue. In addition to this, the pure water flux of the membrane (PANI (B and D)) increased reaching up to 0.0444 and 0.05824-ml. min-1 respectively at a pressure of 3.0 bars. Highlights Composites based on different doped PANIs prepared using the reverse phase method. The percentages of the different formulations were carefully considered. Several techniques were proposed to confirm the presence of the dopant in the structure of PANI and polysulfone. The techniques were used to study the performance of the developed membranes. The results obtained confirmed the usefulness of the developed membranes in the field of wastewater purification, especially methylene blue.
Analytical solutions of 1D population balance equation at steady-state
Due to their effectiveness in separation and purification, two-phase flow columns (liquid-liquid, gas-liquid, and solid-liquid) are extensively utilized in the chemical industries. PBE has recently been recognized as an appropriate tool for modeling this kind of column owing to its ability to describe both the hydrodynamics and the mass transfer of the dispersed phase. In this work, we solved analytically one-dimensional PBE at steady-state using the Adomian decomposition method and the Method of moments. Analytical solutions are provided for pure growth, pure breakup, breakup with growth, pure aggregation, and breakup with growth with aggregation. The obtained results encourage extending the applicability of both methods to solve 1D PBE. Highlights Analytical solutions of the one-dimensional steady-state Population Balance Equation (PBE) are presented. The Adomian Decomposition Method (ADM) is applied to solve cases involving breakup, aggregation, and growth. The Method of Moments (MOM) is used to handle combined growth, breakup, and aggregation processes. Both space-dependent and volume-dependent particle velocity models are considered. The results enhance understanding of dispersed phase behavior in two-phase flow columns and confirm the effectiveness of ADM and MOM.
Organoclay As a Potential Eco-friendly Substitute Of Chalk In The Manufacturing Of The PVC Based Electric Cable
The aim of this work was to study the effects of an organoclay on the properties of a polyvinyl chloride polymer and to compare the obtained results to polyvinyl chloride/chalk counterpart in order to replace the no eco-friendly and no-economic chalk by the cheap and eco-friendly organoclay in the electric cable polyvinyl chloride manufacturing. The obtained nanocomposites were prepared by dry blending followed by extrusion. The x-ray diffraction analysis evidenced an intercalation of the polyvinyl chloride chains between organoclay platelets. The thermal stability (Beilstein test) of the nanocomposite was greatly improved and thermgravimetric analysis (TGA) showed that the formulation containing 1 wt % of organoclay is the more thermally stable up to 240 °C. Differential scanning analysis showed that the glass transition temperature of the nanocomposite is higher than the neat polyvinyl chloride. A rheological analysis revealed that the addition of organoclay had not damaged the processability of the nanocomposite. Scanning electronic microscopy analysis revealed a uniform dispersion of the organoclay particles in the polyvinyl chloride matrix. The PVC based organoclay exhibits properties better than PVC based chalk used in the industry. So, the eco-friendly organoclay can be a good alternative to the expensive and irritating chalk. Highlights 1% organoclay improves PVC strength, ductility, and thermal stability. XRD shows intercalation at 1% organoclay, enhancing composite structure. DSC confirms higher Tg for 1% organoclay due to chain confinement. Organoclay offers better processability and lower energy use than chalk. SEM reveals uniform dispersion only at low organoclay loading.
Copyright (c) 2025 Journal of Applied Engineering Sciences & Technology https://creativecommons.org/licenses/by-nc/4.0
Drying of beetroots (Beta vulgaris L.) using oven dryer
Removal of moisture from food is popularly called drying and it is one of the most vital preservation techniques used in the food industry. In this study, the beetroots (Beta vulgaris L.) were dried in a laboratory oven dryer. The samples of fresh beetroots were dehydrated under a temperature of 50°C. The experimental study selected three different forms of the product, we choose a square form with (5 × 5 cm) and thickness e = 5 mm, a semi-circle form with thickness e = 5 mm and diameter D = 5 mm, and a triangle form with (5 × 5 × 5 cm) and thickness e = 4 mm. The main objective of the present study is to find the selection of the drying techniques essential to producing high-quality dried products in a rational time. The results give the moisture ratio of the different forms of the beetroot product as a function of time drying, while the triangle form responded to the drying process faster than the other two forms. Highlights Beets dried at 50 °C in oven using 3 geometric shapes. Triangle shape dried fastest due to smaller thickness. Moisture ratio dropped to nearly zero after 325 min. Square shape retained more water and dried slower. Drying time linked more to thickness than shape.
Copyright (c) 2025 Journal of Applied Engineering Science & Technology https://creativecommons.org/licenses/by-nc/4.0
A parametric analysis of the earth air heat exchangers' thermal efficiency and their effect on surrounding soil over time
Earth Air Heat Exchanger (EAHE) system is widely regarded as an efficient and sustainable solution, minimizing the consumption of energy and enhancing indoor thermal comfort. This study seeks to conduct a detailed analysis of the parameters that affect the performance of EAHE systems, including the surrounding soil, climatic conditions, and time variations. A semi analytical numerical model was used and verified with existing literature data. Key parameters such as air velocity, operational periods, and soil thermal conductivity were investigated for their effect on the performance of the EAHE and the surrounding soil. The findings revealed that the model provided predictions that strongly agreed with experimental results, with only a 2.3% error margin. The study found that EAHE performance is predominantly influenced by higher soil conductivity and lower airflow velocity. In contrast, the duration of operation had minimal effect on the outlet air temperature, which increased by just 1 °C over 48 h compared to the 1st h. Lastly, the cooling of the surrounding atmosphere was identified as a key factor in enhancing the exchanger's efficiency, as it helps cool the soil after extended operation, thus restoring its cooling ability. Highlights EAHE outlet temp rose only 1 °C after 48 h continuous operation. Higher soil conductivity enhances heat transfer and cooling. Increased air velocity reduces heat exchange and cooling effect. Soil heats up over time, reducing EAHE performance without rest. Model was validated with just 2.3% error vs. experimental data.
CFD Analysis of Hybrid Photovoltaic Thermal (PV/Th) Solar Collector Efficiency Incorporating Ag-AL2O3/water Hybrid Nanofluids
The optimization of energy consumption is closely tied to enhancing the power output of photovoltaic panels. This study offers a numerical investigation of the utilization of hybrid nanofluids (Ag-Al2O3-water) as a cooling fluid in a hybrid photovoltaic thermal (PV/Th) collector, aiming to improve electrical performance by lowering the PV cells operating temperature. The hybrid PV/Th collector comprises a photovoltaic panel (PV) coupled with a thermal collector, including a heat sink equipped with rectangular ribs positioned at the bottom of the PV module. This research explores the impact of critical configuration parameters, such as inlet velocities of working fluid and nanoparticle volume fractions, on the Nu number, PV cell temperature, and both thermal and electrical efficiencies within steady-state operating conditions. The 3D numerical simulation to analyze the overall performance of a hybrid PV/Th collector was conducted using ANSYS Fluent software version 17.1. The numerical findings demonstrate that increasing the nanoparticle volume fraction elevates the cooling fluid's thermal conductivity, consequently enhancing the heat transfer by conduction. Furthermore, higher coolant velocities enhance heat transfer by convection, resulting in a more effective heat transfer rate within the PV/Th system. This, in turn, reduces the operating temperature and significantly enhances the hybrid PV/Th system's overall performance. Highlights Hybrid nanofluid cooling reduces PV cell temp and boosts overall system efficiency. Higher Re numbers and nanoparticle loads enhance thermal and electrical performance. ANSYS CFD showed max total efficiency of 44.7% at Re = 800, Φ = 0.06. Ag-Al2O3 nanofluid outperformed water alone in PV/Th heat transfer. PV cell temp dropped from 60.1°C to 40.6°C using nanofluid at high flow rate.
Hybrid Photovoltaic-Thermal solar collectors
Integrating AI into Key Enabling Technologies for 6G Networks: A Review from SDN to Quantum Computing
This review article provides an in-depth analysis of integrating artificial intelligence (AI) into key enabling technologies for sixth-generation (6G) wireless networks. It examines how AI can enhance the performance and efficiency of technologies such as software-defined networking (SDN), network functions virtualization (NFV), network slicing, edge and cloud computing, and quantum communications. The study also covers other emerging technologies like reconfigurable intelligent surfaces, terahertz communications, holography, and neuromorphic computing. It identifies technical, security, and interoperability challenges related to this integration while exploring future perspectives and promising research directions. The article aims to provide a comprehensive understanding of the current state of AI integration in 6G technologies, thereby offering valuable guidance for researchers, engineers, and decision-makers in this rapidly evolving field. Highlights AI enhances SDN, NFV, and slicing for smarter 6G network control. AI boosts real-time edge/cloud decisions and resource use. Quantum and THz tech gain security and speed via AI tools. AI enables dynamic holography, RIS, and beamforming in 6G. Integration faces privacy, energy, and standardization challenges.
Corrosion inhibition effect of arabic gum on Cu-WC nanocomposite coating synthesized by electrodeposition technology
Nanostructured Cu-WC composite coatings were electrodeposited by co-deposition process onto pretreated steel substrate from an acidic sulfate electrolyte bath containing various amount of dispersed WC powder. The analysis by scanning electron microscopy shows those Cu-WC composite coatings containing cracks and random distribution of the oval-shaped WC particles. The X-ray diffraction (XRD) reveals that the structure of Cu-WC coatings is controlled by the WC powder amounts in the electrolyte baths. The average crystallite size was calculated by use X-ray diffraction analysis and its increasing is proportional to the enhancement of WC solid particles amount. The crystallite structure was fcc for electrodeposited Cu-WC nanocomposite coatings. The potentiodynamic polarization and electrochemical impedance spectroscopic studies reveal that grain refinement offers the best corrosion resistance. Arabic gum shows that it is an anodic inhibitor with high inhibitor efficiency reaches 70.95%. IR spectroscopy analysis shows several functional groups responsible for high inhibitor efficiency. Highlights Cu-WC coatings were electrodeposited with varying WC content onto steel substrates. SEM and XRD showed random WC distribution and fcc structure with increasing grain size. 10 g/L WC coating had the best corrosion resistance in 3.5% NaCl. Arabic gum improved corrosion resistance, acting as an effective anodic inhibitor. EIS confirmed max inhibitor efficiency of 70.95% at 25 g/L WC with Arabic gum.
Analysis of legibility in urban public spaces. Case of El-Alia North-East neighborhood in Biskra, Algeria
The Algerian city faces serious problems related to various dysfunctions, a planned urban structure and a social structure suffering from various social ills. This has a noticeable effect on urban public spaces. The latter are the receptacle of a typology of behaviors, of ways of consuming space that seem to depend on the spatial conformation, the legibility, the identification and the orientation of the user. The present work seeks to explain the relation between legibility and dysfunction in the urban public space and to characterize the influence of space on the movement of pedestrians therefore on their behavior. The selected case study is urban public spaces in the spontaneous neighborhoods of El Alia North-east of the city of Biskra. As a model of analysis, we proposed the combination of two methods obtained from the literature, namely the method of the responsive environments and the method of space syntax. We confronted the results of the analysis of the space syntax and the results of the investigation by the technique of the direct observation "Gate counts". We have shown that the quality of urban public spaces in terms of legibility affects their functioning and their stability.
Copyright (c) 2018 https://creativecommons.org/licenses/by-nc/4.0
Improving thermal comfort conditions through the optimization of the self-product residential buildings envelope. Case of a region with a hot and arid climate: Biskra
To improve the thermal comfort conditions of the occupants in the individual housingand to reduce the energy consumption induced by the heating and cooling needs in the building, itis necessary to act on the main element which controls the heat exchanges with the environment:the envelope. This refers to the building’s outer skin that consisting of vertical opaque components(the walls ...), horizontal ones (roof ...) and various opening devices. The thermal performance ofthe envelope is mainly due to its geometrical and formal attributes, but the material characteristicsof its components remain decisive for thermal exchanges with the environment. As part of thebuilding at the interface of the indoor ambiances and the outdoor environment, the envelope isoften the seat of a large number of heat exchange phenomena that affect not only the premisesenergy consumption but also the thermal comfort conditions of their occupants. This papersummarizes the main results obtained from an in-situ measurement campaign to evaluate thedesign parameters influencing the thermal comfort of self-produced individual housing relative tothe hot and arid climate of Biskra. In addition, a thermal simulation carried out with the TYRNSYS17 software has demonstrated the potential of improving the thermal comfort conditions of theself-produced individual housing thanks to adequate choices concerning the architectural andconstructive attributes of the envelope.
Numerical study of the active earth pressure distribution on cylindrical shafts using 2D finite difference code
The present paper examine the distribution of the active pressure on a circular shaftembedded in granular material subjected to radial displacement. The deformation problem wassolved under axisymmetric conditions using explicit finite difference code FLAC (Fast LagrangianAnalyses of Continua). Based on the numerical results, the distribution of the active pressure withincreasing excavation depth is non-linear for all interface angle of the shaft, for different diametersand height of the shaft also for the all friction angles of the soil. When friction angle of the soil thatare less than, or equal to 10° the active pressure is linear. These results are summarized andcompared against previously published theoretical solutions and experimental results.
Evaluation of the thermal environment in architecture hotel of Fernand Pouillon. Case of the Ziban Hotel in Biskra
The main objective of this study is to evaluate the impact of the orientation on thethermal environment in the works of Fernand Pouillon and its role in the reduction of the strongcontinuous and daily variations of the temperatures. In the region of Biskra, Fernand Pouillon,seems to show his mastery of the parameters related to the external physical environment inorder to create suitable indoor thermal environments in a hot and arid climate. In this regard, weused the experimental method, through the ECOTECT digital simulation program, to study thequantitative aspects of these thermal environments. Thus, we have particularly studied theinfluence of the orientation with respect to the sun and the wind on the thermal environments ofour case study. Finally, a comparison between the temperatures, in the successive sequences,allowed us to demonstrate that the preferred choices in orientation by Fernand Pouillon areadequate or not.
Effect of the eccentric load on the bearing capacity of a strip footing founded on sand
The finite differences FLAC 2D software which allows to model all soil-structureinteractions regardless of the difficulty of the problems is used to determine the bearing capacityand stress distribution under a rigid strip footing submitted to vertical centered and eccentricloads. The footing is set on a free surface of sand with no surcharge applied. The soil is assumed tobe elastic – perfectly plastic following the Mohr–Coulomb failure criterion. The results of thepresent study show that the conception proposed by Meyerhof tends to underestimate thebearing capacity, especially for large eccentricities. The study proposes an expression of theeffective width that gives reasonable bearing capacity values, even for large eccentricities.
Thermal performance of the horizontal opening in the traditional houses of old Biskra. Case of traditional house at Bab Edarb
This research aims to revive a traditional architecture heritage of Biskra, which is thehorizontal opening in the roof of the "wast edar" named “raouzna". In order to evaluate thethermal performance of this element and measure its ability to control the distribution of interiortemperature in a region submitted to a hot and dry climate, an experimental study by numericalsimulation was carried out. DEROB-LTH program was used to perform the work of simulationwhich focused on one set of constant and variable factors. These factors are related to climatedata, thermal’s comfort zone and to the dimensions and shape of the raouzna. Some of the dataused for the simulation are based on the results of a typo-morphological analysis of a corpus oftraditional houses and a survey carried out upstream in the quarter of Bab Edarb (old Biskra). Thestudy focuses on the comparison between the recorded temperature inside the traditional houseand the outside air, and for periods critical of winter and summer represented respectively by thecoldest month and hottest: January and July.
Valorization of Vase Dam by the addition of the cement kiln Dust (CKD
This study is the valuation of the mud dam Charef - Djelfa Wilaya in basic layers ofmaterial by the chemical stabilization process based on the addition of cement kiln dust (CKD)who considered under product from the manufacture of cement. In this context we came throughparticle size analysis tests, plasticity, chemical analysis, compaction, and simple compression ondifferent samples of mud treated with different percentages of CKD and stored at a period of 28days to change the consistency of the untreated mud and was a firm consistency to a hard andstable consistency by adding a percentage of 20% CKD.
Numerical study of the bearing capacity of a strip footing on tow layered clay under inclined loading
The bearing capacity of a strip footing resting on a homogeneous and isotropic soil hasbeen the subject of numerous theoretical and experimental studies. However, in practice the soilis never homogeneous. It is therefore important to introduce the effect of stratification on thebearing capacity. This paper aims to indicate the modifications that must be made to the bearingcapacity of a rough strip footing resting on two layered clay subjected to inclined load. The finite-difference code Fast Lagrangian Analysis of Continua (FLAC) is used to estimate the bearingcapacity factor Nc* as well as the failure envelope and the inclination factors ic, in the case ofinclined loading. The study is carried out considering two layers clays of different shear strengths,where the thickness of the upper clay layer is comparable to the width of a rigid footing. Theresults obtained show clearly that the bearing capacity of a strip footing is generally depends onthe strength ratio of the soil layers (cu1/cu2) and the relative thickness of the top layer (D/B).
Numerical modeling of the prestressing losses in prestressed concrete beams by modal analysis method
In this paper, a numerical modal analysis method is carried out to investigate the effectof cable strain loss on the natural frequencies in prestressed concrete beams. A simply supportedconcrete beam is modeled using the commercial finite element code ABAQUS. The beam iscomposed of concrete and prestressing strands. Firstly, a general geometrically nonlinear staticanalysis is carried out on the beam in order to obtain the camber deflection under differentprestressing magnitudes. The obtained equilibrium configuration is then used to perform a linearand nonlinear modal analysis. Thereby, a three dimensional finite element C3D8 is used for theconcrete in combination with a damaged plasticity model (CDP) are considered. Whereas, theprestressing strands are modeled with an embedded T2D2 truss element. The obtained resultsshow a good agreement with previous numerical and experimental works in literature.Furthermore, the study showed that the safety of prestressed beams depend mainly on the levelof prestressing load.
Study and optimization of the windows’ impact on thermal comfort and energy efficiency (Case of offices in a hot and arid climate)
Controlling the thermal environment and reducing the energy consumption of buildings across the façade are a difficult challenge for architects, especially in a desert climate. The windows in particular play an important role in the tandem of the thermal operation of the building and the comfort of the users. The objective of this article is to study and optimize the impact of windows, their material and proportional characteristics on the thermal comfort and energy efficiency of office buildings in a hot and arid climate. The investigation is based on an empirical approach (measurements taken in situ on real cases) as well as on a numerical simulation study with the TRNSYS program. Several parameters have been studied such as surface temperature, ambient temperature and energy consumption. The results showed that facade windows are a determining factor in the thermal exchanges between the building and its environment and that the key parameters that condition these exchanges are the windows ratio (glazed area) and the type of glazing. The judicious choice of the windows ratio combined with an appropriate choice of the type and composition of the glazing improves the thermal comfort of the users and ensures the energy performance of the building.
Effects of active mineral additions on the concrete behavior based on demolition sands
The exhaustion of natural aggregate deposits and the difficulties of opening new quarriesmake it necessary to look for new sources of supply. Recycling and recovery of waste are nowconsidered a solution for the future in order to meet the shortfall between production andconsumption and protect the environment. The objective of this study is to evaluate the effect ofactive mineral additions (Pozzolana, slag and silica fume) and inert (calcareous) on the behavior ofconcrete using recycled fine aggregates. The results obtained in this experimental study allow usto draw the conclusion that the use of additions (pozzolana , limestone fillers, silica fume and slag)improves the physico-mechanical and, more particularly, rheological characteristics of concretesbased on 50% of recycled fine aggregate.
A new frequency analysis for diagnosis of bearing defects in induction motors using the adaptive lifting scheme of wavelet transforms
This work describes a novel and effective application of the adaptive wavelet transformfor the detection of bearing faults on induction motor stator current. This transform is based on athree-step nonlinear lifting scheme: a fixed prediction followed by a space-varying update and a noadditive prediction. This transformation technique is used in a diversity of applications in digitalsignal processing and the transmission or storage of sampled data (notably the compression of thesound, or physical measurements of accuracy). Many faults in induction motor have beenidentified as bearing defects, rotor defects and external defects. Experimental results confirm theutility and the effectiveness of the proposed method for outer raceway fault diagnosis under noload and full load conditions.
Effect of urban morphology on thermal comfort in outdoor spaces: the case of the red village-El Kantara-Biskra
Climate urban design is today a topical issue dealt with in many recent studies. This paper aims to test the influence of urban morphology on external climatic conditions and the urban microclimate by dealing with the quantitative aspects of thermal comfort and the assessment of the thermal environment from an objective point of view. This is based on an on-site investigation based on the correlation between the geometry of the street, its orientation and the evolution of the physical variables (Ta, Tg, HR, Va). The measures were the subject of a campaign carried out in the urban fabric of the Ksar of Dachra El- Hamra (the red village), the first nucleus of the city of El Kantara in the wilaya of Biskra. The objective is to define the most efficient urban geometry in terms of summer thermal comfort by studying the true impacts of urban form on solar control and microclimatic conditions in arid regions. The evaluation of the thermal comfort in these external spaces is carried out by analyzing the calculated physiological temperature (PET) values based on the measured microclimatic parameters. The analysis of the results obtained from the investigation enabled us to demonstrate the considerable effect of the sky view factor, calculated by Rayman Pro 2.1 software, on the thermal fluctuations in the street.
Vision Based Tracking and Interception of Moving Target by Mobile Robot Using Fuzzy Control
This paper presents a simple Fuzzy Logic Controllers (FLC) based control strategy to solvethe tracking and interception problem of a moving target by a mobile robot equipped with a pan-tilt camera. Before sending commands to the mobile robot, video acquisition and image processingtechniques are employed to estimate the target’s position in the image plane. The estimatecoordinates are used by a fuzzy logic controller to control the pan-tilt camera angles. The objectiveis to ensure that the moving target is always at the middle of the camera image plane. A secondFLC is used to control the robot orientation and to guarantee the tracking and interception of thetarget. The proposed pan-tilt camera and robot orientation controllers’ efficiency has beenvalidated by simulation under Matlab using Virtual Reality Toolbox.
The effect of the patio on the indoor thermal performancein the colonial courtyard houses in the saharan climate. The case of Biskra in Algeria
A wide range of studies related to the evaluation of thermal comfort were undertaken on various types of buildings as an attempt to draw up that the interaction between the environment and the user is necessary to properly evaluate the indoor thermal comfort. The present research aims to explore the thermal quality within the French colonial houses in the town of Biskra where many passive techniques have been used for modifying the interior climate by promoting the passive cooling devices, inspired by the local traditional architecture. The courtyard, which is a one of the bioclimatic strategies to reduce the external climatic constraints, is also a key for passive cooling. Consequently, this work aims to characterize the impact of the patio in a saharan climate on the ambiance quality of the interior space of the houses. In this paper, an investigation is being conducted in five houses with patio, chosen as representative samples of colonial architecture in Biskra by an objective experimental method that contains in situ useful measurements for the calculation of Top and Tmr comfort indices according to the ISO 7730 standard for the evaluation of thermal comfort summer. In order to build more comfortable houses, many traditional techniques could be improved by using modern knowledge, rather than to be totally abandoned.
Experimental study of solar adsorption refrigeration device
This work presents an experimental study of a solar adsorption refrigeration device using activated carbon AC-35 /methanol as working pair. The studied device is designed, realized and tested in the Development of Solar Equipment Unit, UDES, Tipaza (Algeria). The adsorption and desorption tests, carried out on the experimental device, were conducted inside the laboratory using a halogen lamp as an energy source instead the sun. The lamp is installed perpendicularly to the surface of the tubular adsorber to test four radiation levels: 800, 820, 1000 and 1020 W/m². A calculation code is developed, using the Dubinin-Astakhov mathematical model, to evaluate the thermodynamic coefficient of performance, COP th , of the experimental device. Thus, a parametric study is presented to examine the influence of the construction material and the weight of the adsorber on the COP th , the amount of cold produced in the evaporator, Qf, and the total heat supplied to the system, Qc.
Study of texture and recrystallization in commercial pure copper wire with and without heat treatment
Wire drawing is a necessary operation for the production of small diameter electricalwires. During this process, the shaping of the material is performed by a plastic deformationmechanism. The change in the shape of the metal causes the plastic deformation of each grain ofthe crystalline metal. In this work, we have studied a commercial copper wire. In this study, opticalmicroscopy, electron microscopy transmission, Vickers hardness and X-ray diffraction were used.It is found that cold drawn wires are characterized by texture formation and dislocation cellrearrangement. Isothermal treatments were applied on the deformed yarns, which makes itpossible to observe a recrystallization reaction which restores the mechanical properties and theinitial structure.
Numerical simulation of convective heat losses in a helical tube of a cylindrical solar receiver
In this paper, natural convection heat losses in a cylindrical solar receiver areinvestigated numerically. The study is conducted using three helical tube diameters: 12mm,16mm and 25mm. The diameter of the receiver is 0.3 m with an aspect ratio equal to one andthree aperture ratios of 1, 0.75 and 0.5. In each case, the receiver tube inside the cylindricalcavity is modelled by a helical spiral similar to those of real systems. The simulations areperformed for three inlet temperatures (of 50, 75 and 100°C) and four receiver tilt angles (of 0,30, 60 and 900) with a constant mass flow rate of 0.0885 kg/s. The effects of some parameterssuch as receiver size, boundary conditions, tube diameter, receiver tilt, inlet temperature andopening ratio on convective heat losses and outlet temperature are presented in form of graphs.It has been found that the convective heat losses are reduced by using the adiabatic boundarycondition imposed on the half-circumference of the tube. Thus, increasing the helical tubediameter causes an increasing in the convective heat losses. The increasing of the fluidtemperature and the opening ratio are found proportional to the increasing of convective heatlosses.
Beyond thermal comfort in the hospital rooms. Investigation of thermal summer comfort in patients rooms: case of Biskra hospitals
In Algeria, the architectural design of hospitals is unfortunately not subject to clear and specific regulatory thermal strategy, it depends mainly on the architect own approach to the issue of comfort design, materials, etc. This research aims to investigate the present comfort conditions in typical hospital configuration and under specific climate conditions of hot and arid regions. Two different hospital designs have been investigated in Biskra. A main town is southeast of Algeria. The first case study being the oldest hospital in the town, build in the late 30s during the colonial era and renovated recently. The second hospital is a brand new hospital. A series of measurements of ambient air temperature, patient surveys and interviews have been initiated in two typical wards. The results show that thermal comfort sensations in these specific spaces depend not only on architecture, design and typical processes, but also on physiological, psychological and behavioral parameters which widely influence the perception of the patients.
Evaluation of the sound environment of the city of Biskra (Algeria)
This research concerns the quantitative evaluation of the urban sound environment of the city of Biskra. The aim was to determine the quality of the soundscape based on in situ measurement, using a Landtek SL5868P sound level meter. 62 points have been identified to represent the whole city. The results show that that the noise level varies from 54.1 to 75.8 dB(A) during the weekdays and from 50.4 to 74.2dB(A) during the weekend. In addition,90% of the results of the weekday measurements and 81% of the results of the weekend measurements exceed the recommended levels given by the World Health Organization. The present urban sound exposure could have a substantial impact on the overall comfort of inhabitants and increase the risk of the syndrome of the sick cities.