بالتعاون مع المديرية العامة للبحث العلمي والتطوير التكنولوجي ينظم مركز البحث العلمي والتقني في التحاليل الفيزيائية والكيميائية فعاليات اليوم الإعلاميي الوطني لمشاريع البحث الخاصة ببرنامج دول البحر الأبيض المتوسط و هي فرصة لمجتمع الباحثين الجزائريين في مراكز البحث و الجامعات و القطاع الإقتصادي والإجتماعي من أجل الإستعلام حول هذا البرنامج المتوسطى من حيث مواضيع البرنامج و الإحاطة بقوانين ،كيفية المساهمة والمشاركة فيه وذلك يوم الأربعاء 17 مارس 2021 على منصة الزووم .فكونوا في الموعدروابط الحضور سترسل للمسجلين يوم 16 مارس 2021 قبل الساعة الخامسة مساءاالعدد محدود على منصة الزووم و يقدر بـ 100 مشارك .يمكن متابعة فعاليات اليوم التعريفي عبر صفحات التواصل الإجتماعي للمركز و المديرية العامة للبحث العلمي من خلال البث الحي والمباشر وايضا على قناة اليوتيوب للمركز
قام الأستاذ عبد الباقي بن زيان وزير التعليم العالي والبحث العلمي يوم الثلاثاء 09 مارس 2021، معاينة مشروع إنجاز المقر الإداري الجديد لمركز البحث العلمي والتقني للتحاليل الفيزيائية والكيميائية.وهذا على إثر زيارة عمل وتفقد إلى ولاية تيبازة، وقد استهل الزيارة إلى القطب الجامعي بالقليعة ، بتدشين عدة منشأت تابع للقطاع أيضا
رابط مشاهدة العرض المقدم للسيد الوزير من الطرف مدير المركز الدكتور بشاري خلدون
(a)-LEA, Department of Electronics, University of Batna 2, Batna, 05000, Algeria
(b)-Research Scientific and Technical Center on Physico-Chemical Analysis (CRAPC), Tipaza, Algeria
Received 30 August 2020,
Revised 12 December 2020,
Accepted 30 December 2020,
Available online 3 January 2021.
In this paper, the optimization, elaboration and characterization of an efficient spectral beam splitter based on a simple RF sputtered ITO/Ag/ITO (IAI) ultra-thin multilayer structure are presented. An experimental investigation assisted by Genetic Algorithm (GA) metaheuristic optimization was carried out to achieve high-performance spectral splitter for tandem solar cell applications. The RF magnetron sputtering method was used to elaborate the optimized IAI structure. The optical and structural properties of the sputtered splitter were also analyzed using UV–Vis-IR spectroscopy and X-ray diffraction (XRD) measurements. It is found that the elaborated splitter structure offers 84% of transparency and a high reflectance of 87% with an optimum cut-off wavelength of 800 nm. This is attributed to the design approach, which leads to promote spectral splitting mechanism by inducing efficient optical modulation. Interestingly, a new Figure of Merit (FoM) parameter, which evaluates the optical splitting performances is proposed. Moreover, a new Perovskite/InGaAs tandem cell is proposed and analyzed to show the impact of the elaborated spectrum splitter on the solar cell efficiency. It is revealed that the investigated solar cell exhibits an improved efficiency approaching 30%. The latter value far surpasses that provided by Perovskite tandem cells. These results indicate that our spectrum splitting approach can open a new pathway towards designing high-performance tandem photovoltaic devices.
Recently, the emergence of multi-junction technology at a reasonable cost has allowed a stunning progress in renewable energy resources [, , , ]. Perovskite solar cells (PSCs) have attracted an enormous deal of attention to develop low-cost and high-efficiency tandem photovoltaic systems. This is due to the large flexibility, tunable band-gap and lower fabrication cost of perovskite materials [, , , ]. Numerous Perovskite tandem architectures based on mechanically stacked or monolithically series-connected designs are proposed to achieve high absorption properties using different bottom-cells based on Silicon, GaAs, CIGS, Ge and CZTS materials [, , , , , , , , ]. However, the recorded efficiencies are still far from the expectations, where all forms of recombination, resistive and optical losses should be suppressed. Intuitively, combining (FAPbI3)0.95(MAPbBr3)0.05 Perovskite absorber showing 1.5eV band-gap with InGaAs narrow band-gap material (0.75eV) can offer a new pathway to develop efficient tandem SC, exhibiting a high photoresponse over the whole solar spectrum [18,19]. Therefore, this calls for a renewed performance assessment of Perovskite/InGaAs tandem photovoltaic device to potentially break the inherent limit associated with single-junction SCs. However, several undesired effects would be occurred when considering the latter tandem structure such as the need for complex interconnection layers, current matching condition, thermalization, lattice mismatching effects, optical and recombination losses that can drastically limit the multi-junction SC efficiency [, , , , ]. In addition, the bottom cell based on narrow band-gap materials generates much more current density leading to huge power dissipation as heat. This can in turn prevent maintaining low working temperatures, thus affecting the panel reliability against the degradation induced by heating effects. This becomes more severe when light concentrators are incorporated thereby reducing enormously the SC practical efficiency. Particularly, this effect is common for PSCs technology, where stability issues are more pronounced. One approach to avoid these undesired effects is to use spectral beam splitter technique, which has enabled higher efficiencies and regarded readily accessible to the photovoltaic industry [, , , ]. The optical splitter separates the incident sun-light into some parts of spectral ranges and each part is directed to individual sub-cells whose band-gap energies correspond to the appropriate spectral range. Numerous splitting systems were proposed in the literature such as prismatic lens, dichroic coating and luminescence solar concentrator [, , , , , , , , ]. Nevertheless, it is still complex, sophisticated and time consuming to fabricate reliable and efficient beam splitter systems for tandem photovoltaics, where high number of interference layers is required to achieve suitable cut-off wavelength, reduced optical losses and sloped transition [, , ]. Accordingly, using adequate thin-film materials with reduced interference layers, while ensuring high splitting performances can open up the route for the elaboration of high-efficiency tandem SCs at low-cost. In this context, several multilayer-based structures have been developed for thermal-solar hybrid systems demonstrating a great promise in achieving suitable splitting characteristics and high energy harvesting performances [, , , , , , , , , , , , , ]. However, they did not prove any benefit over the conventional ones in terms of cut-off wavelength tunability and optical properties. These effects make them too upstream to yet contemplate a potential deployment in tandem photovoltaic systems. To the best of our knowledge, no investigations based on a strategic combination between ITO/Ag/ITO (IAI) multilayer spectrum splitter and a new Perovskite/InGaAs tandem SC structure were conducted to achieve superior conversion efficiency at low-cost. To do so, in this paper, an experimental study assisted by systematic optimization approach was carried out for elaborating an efficient IAI multilayer structure. The optimized structure was prepared by RF magnetron sputtering technique and its optical and structural characteristics were analyzed using UV–Vis-IR and XRD measurements. It was revealed that the elaborated IAI multilayer spectrum-splitter exhibits 84% of transparency and a reflectance of 87% with an optimum cut-off wavelength of 800 nm, which has led to achieve a high-efficiency Perovskite/InGaAs tandem SC of 29.6%. Therefore, the proposed design and elaboration approaches not only provide promising techniques to optimize the performance of IAI multilayer spectrum-splitters by using metaheuristic methods, but also open up the way to develop high-efficiency tandem SCs
(a)-Department of Sciences and Technology, University Center of Tamanrasset, Algeria
(b)-LEA, Department of Electronics, University of Batna 2, Batna 05000, Algeria
(c)-Research Scientific and Technical Center on Physico-Chemical Analysis (CRAPC), Algeria
Received 27 October 2020,
Revised 3 December 2020,
Accepted 5 December 2020,
Available online 18 December 2020.
Cost-effective multispectral photodetectors (PDs) exhibiting a high UV–Visible–NIR photoresponse offer an avenue for developing environmental monitoring devices, imaging sensors, object discrimination, and optical links. However, PDs based on a single semiconductor as light-sensitive layer are unable to provide broadband photodetection properties. In this work, a new PD device based on ZnO-ZnS Microstructured Composite (MC) which achieves a high UV–Visible-NIR photoresponse is demonstrated. The ZnO-ZnS MC is elaborated by combining vacuum thermal evaporation technique and a suitable annealing process. Scanning Electron Microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and UV–Vis-NIR spectroscopy were used to elucidate the morphological, structural and optical properties of the prepared sample. It was demonstrated that the ZnO-ZnS MC can be useful to enhance the visible absorbance efficiency by promoting efficient light-scattering effects. It is revealed that the prepared UV-Vis-NIR PD offers a low dark current of 5 nA, a high ION/IOFF ratio of 78 dB and an enhanced responsivity in UV, visible and NIR ranges. The proposed multispectral PD demonstrates a high ION/IOFF current ratio under self-powered working regime. Therefore, the proposed ZnO-ZnS MC is believed to provide new insights in developing efficient, self-powered and low-cost multispectral PDs for high-performance optoelectronic systems.
في اطار تجسيد مشروع النظام الذكي لتسيير النفايات #الحاوية_الذكية المبتكر من طرف الشركة الناشئة في مجال البيئة للباحثين والمخترعين زهرة بغدادي و توفيق بغدادي #Startup_Les_BAGHDADI_S و التي يرافقها مركز البحث العلمي والتقني في التحاليل الفيزيائية والكيميائية #CRAPC ويدعمها و أيضا الحاصلين على المرتبة الاولى في مسابقة تحدي مبتكر كرابسي 2018 التي نظمها مركز البحث العلمي والتقني للتحاليل الفزياىية والكمياىية ببوسماعيل، بمشروع الحاوية الذكية هي نظام ذكي لتسيير النفايات بالفرز لجمع النفايات المنزلية وهو حل مبتكر وذكي في مجال تسيير النفايات للمدن،تم احتضانه والموافقة عليه من أجل تجسيده على أرض الواقع بأحياء العاصمة بكل من بلديتي #الرغاية و #الرويبة
CoBi2O4 (CBO) nanoparticles were synthesized by sol-gel method using polyvinylpyrrolidone (PVP) as a complexing reagent. For a single phase with the spinel structure, the formed gel was dried and calcined at four temperatures stages. Various methods were used to identify and characterize the obtained spinel, such as X-ray diffraction (XRD), scanning electron micrograph (SEM-EDX), transmission electron microscope (TEM), Fourier transform infrared (FT-IR), X-ray fluorescence (XRF), Raman, and UV-Vis spectroscopies. The photocatalytic activity of CBO was examined for the degradation of a pharmaceutical product cefixime (CFX). Furthermore, for the prediction of the CFX degradation rate, an artificial neural network model was used. The network was trained using the experimental data obtained at different pH with different CBO doses and initial CFX concentrations. To optimize the network, various algorithms and transfer functions for the hidden layer were tested. By calculating the mean square error (MSE), 13 neurons were found to be the optimal number of neurons and produced the highest coefficient of correlation R2 of 99.6%. The relative significance of the input variables was calculated, and the most impacting input was proved to be the initial CFX concentration. The effects of some scavenging agents were also studied. The results confirmed the dominant role of hydroxyl radical OH• in the degradation process. With the novel CoBi2O4/ZnO hetero-system, the photocatalytic performance has been enhanced, giving an 80% degradation yield of CFX (10 mg/L) at neutral pH in only 3 h.
في إطار الانفتاح على القطاع الاإقتصادي والإجتماعي و الاكاديمي قامت فرقة المحطة الجهوية للتلفزة الوطنية بورقلةيوم الاربعاء 25 نوفمبر 2020 بزيارة عمل لمقر الارضية التقنية للتحاليل الفيزيائية والكيميائية بورقلة والتابعة لمركز البحث العلمي والتقني في التحاليل الفيزيائية والكيميائية ببواسماعيل من أجل تسجيل حصة لعرضها بحصة صباحيات على القناة الثالثة يوم 07 ديمسمبر 2020 حسب البرنامج المسطر ،إذ تم استقبالها من طرف الدكتور بلخلفة حكيم رئيس مشروع الارضية التقنية و تم وتسجيل عدة مداخلات مع مستخدمي الارضية والتعرف على مختلف التشخيصات والتجهيزات التي تتوفر عليها الأرضية التقنية ومختلف تقنيات التحاليل الفيزيائية والكيميائية التي تتوفر عليها
Research Centre in Analytical Chemistry and Physics (CRAPC), Algiers, Algeria
Since the late 1970s, approaches have been proposed to replace conventional gas chromatography apparatus with silicon-based microfabricated separation systems. Performances are expected to be much improved with miniaturization owing to the reduction of diffusion distances and better thermal management. When it is easy to microfabricate miniaturized parts, the main challenge consists, however, to produce stable, efficient, and functionalized columns. The purpose of the paper is to transpose and adapt monolith synthesis in-situ micromachined gas chromatography columns. Silica-based monolithic microcolumns based on the sol–gel process were tested in the course of high-speed gas chromatographic separations of light hydrocarbons mixture (C1–C4). At the optimum separation conditions, a very good resolution (2.14) for very light compounds (C1–C2) was reached on a 50 cm microcolumn at room temperature with a back-pressure within the range used at gas chromatography facilities (without external modification of the device). The versatility of these microelectromechanical systems (MEMS) columns was demonstrated with a high-temperature C1 – C2 separation, and unsaturated cyclic alkanes. Light halogenated alkanes were also successfully separated. These columns should be used in various applications related to oil/gas and environment field analyses.
aLaboratory of Natural Gas, Faculty of Chemistry, USTHB, Algiers, Algeria
b Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques, Bou-Ismail CP, 42004, Tipaza, Algeria
cDSI-NRF Centre of Excellence in Strong Materials and the Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, 2050, South Africa
To enhance the photocatalytic performance of semiconductors, a highly active and durable SiO2@xNiCuPS photocatalyst was evaluated for photocatalytic hydrogen generation. The photocatalyst was prepared by a hydrothermal method using SiO2 spheres, and a 1:1 Cu:Ni mixture (5 and 10 wt%). The reaction gave a highly stable phyllosilicate material with a core@shell structure. The materials were characterized by a range of techniques. DRS data revealed indirect optical transitions at 1.5 eV and 2.75 eV for the SiO2@5NiCuPS and SiO2@10NiCuPS materials. The new photocatalysts were successfully tested for hydrogen generation under visible irradiation to give H2 yields of 184 and 47 μmol g−1. min−1 for SiO2@5NiCuPS and SiO2@10NiCuPS, respectively. The data suggest that the enhanced activity of adding Cu to Ni to form Ni/Cu phyllosilicates is not due to NiCu alloy formation but due to changes in the support morpholohgy brought about by metal-support interactions. The catalysts were stable over 4 repeat reaction cycles.
Hydrogen Photocatalysis NiCu nanoparticles core@shell material