Editorial
Environmental & Green Materials
Ashutosh Tiwari
Abstract
Climate change is evolving as the major concern of erratic weather conditions for example heavy rains, drought floods, landslides, soil erosion, tsunami, and extreme cold and warm weather, which severely impact the livelihoods of mankind. Attaining the substance by reducing carbon pollution and other ...
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Climate change is evolving as the major concern of erratic weather conditions for example heavy rains, drought floods, landslides, soil erosion, tsunami, and extreme cold and warm weather, which severely impact the livelihoods of mankind. Attaining the substance by reducing carbon pollution and other greenhouse gases is the best way to control climate change. Considering the suitable climate, habitat variation, and their adverse effects such as glaciers, heatwave, sea levels rise, etc., it is important to understand the climate control and framing combat policy as per the requirement of energy. Hydrogen is now established as a clean and flexible energy carrier. Europe and the other nations are progressively walking toward achieving the net-zero objective with the overview of clean hydrogen energy, which will ensure global sustainability faster.
Review Article
Energy Materials & Technology
Shawqi Al Dallal; Khalil Ebrahim Jasim
Abstract
Third generation solar cells, such as dye and quantum dot sensitized solar cells are attracting attention of many research groups. In this investigation we explore the role of dye extract on the enhancement of the photovoltaic properties of quantum dot sensitized solar cells (QDSSCs). Lead sulfide quantum ...
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Third generation solar cells, such as dye and quantum dot sensitized solar cells are attracting attention of many research groups. In this investigation we explore the role of dye extract on the enhancement of the photovoltaic properties of quantum dot sensitized solar cells (QDSSCs). Lead sulfide quantum dots of different sizes have been used to sensitize a nanostructured titanium oxide electrode. We compare the open circuit voltage, the short circuit current, and power conversion efficiency of QDSSCs with the same quantities as obtained for dye-enhanced system using pomegranate dye extract. An open circuit voltage of 166 mV, a short circuit current of 0.1 mA, and an efficiency of 0.32% were obtained for 2.4 nm radius lead sulfide quantum dot sensitized solar cells. Using pomegranate dye extract reveals a considerable enhancement of the above characteristics. The combined dye-quantum dot system produces an open circuit voltage of 300 mV, a short circuit current of 0.55 mA, and an efficiency of 3.4%. For 3.2 nm radius QDs, the efficiency is substantially higher, reaching about 7%. A model describing the structure and processes leading to the above enhancement of the assembled solar cell characteristics is presented. In this model we explain the interplay between the transfer of electrons between the dye, quantum dots, and subsequent injection in the wide band gap titanium dioxide semiconductor.
Research Article
Composite Materials
Kamil Janeczek; Mateusz Kosyl; Aneta Araźna; Michał Czaiński; Krzysztof Lipiec; Wojciech Stęplewski; Marek Kościelski
Abstract
Passive fire protections are one of the safety systems which are installed commonly in buildings. As every kind of such systems these protections have to controlled according to legal regulations. To facilitate periodic checks RFID technology can be successfully used. In this paper, thermal behaviour ...
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Passive fire protections are one of the safety systems which are installed commonly in buildings. As every kind of such systems these protections have to controlled according to legal regulations. To facilitate periodic checks RFID technology can be successfully used. In this paper, thermal behaviour of produced swelling materials suitable for passive fire protection was examined and thermal endurance of RFID tags used to identify these protections was analysed as well. The results achieved in this study showed expected thermal behaviour of the swelling materials which fulfilled the whole space of the protections blocking spreading fire and smoke. Further, it was noticed that a gasket sealant and a high-temperature silicone allowed to decrease temperature affecting RFID tags. Paper-face and hard RFID tags withstood the applied thermal exposure and their readability was restored after cooling down the tags to about 120°C. This means that it is likely that these tags can resist small fire incidents on condition that temperature affecting the tags does not exceed a decomposition temperature of materials used for their production.
Research Article
Energy Materials & Technology
Vineet Kumar Singh
Abstract
In this paper, an n+-poly-silicon/p+-crystalline-silicon tunnel diode has been fabricated and characterized. The n+ poly-silicon layer is deposited by the low-pressure chemical vapor deposition method, while a diffusion furnace is used for boron diffusion in crystalline silicon. Scanning electron microscopy ...
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In this paper, an n+-poly-silicon/p+-crystalline-silicon tunnel diode has been fabricated and characterized. The n+ poly-silicon layer is deposited by the low-pressure chemical vapor deposition method, while a diffusion furnace is used for boron diffusion in crystalline silicon. Scanning electron microscopy and X-ray diffraction pattern have been used for structural characterization. Hall measurement and current-voltage characteristics have been used for carrier density, mobility, current density, and contact resistance measurement. Hall measurement reveals the carrier density of ~1019 cm-3 in phosphorus-doped poly-silicon tunnel layer with mobility of ~5.4 cm2 V-1-s-1. The current-voltage characteristics of the tunnel diode show the current density of ~103 Ampere/cm2 at a voltage of 0.1 Volt. Using tunnel diode, an n+-poly-Si/p+-c-Si/n-c-Si/n+-c-Si structure has been fabricated for photovoltaic application. This structure generates a current density of ~17.9 mA/cm2 and a voltage of 601 mV for a 195±10 nm thick doped poly-silicon layer. Further, to improve the solar cell’s performance, a thin layer of poly-silicon has been used.
Research Article
Composite Materials
Chang Che; Shaohai Ma; Qingchuan Pan; Kai Yan; Gong Qian
Abstract
Super304H (18Cr-9Ni-3Cu-Nb-N) austenite steel has high creep strength and has been used as the material of tubes in 600℃ class supercritical power plants in China. Many Super304H materials have run for more than 100,000 hours. Long-time service feature of these austenitic stainless steels has not been ...
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Super304H (18Cr-9Ni-3Cu-Nb-N) austenite steel has high creep strength and has been used as the material of tubes in 600℃ class supercritical power plants in China. Many Super304H materials have run for more than 100,000 hours. Long-time service feature of these austenitic stainless steels has not been understood. An understanding of the long-term microstructural evolution under actually used conditions is a key for the improvement of these heat resistant steels. In this article, creep behavior of Super304H used in China plants was analyzed, microstructural evolution of Super304H materials after different service conditions were studied involving in optical microscope, TEM and SAXS. The results show, M23C6, Cu-rich particles, and σ phase were found to precipitate. A quantitative assessment of microstructure evolution was given during long-term creep.
Research Article
Ceramic Composite
G. Upender; V. Chandra Mouli; V. Sreenivasulu; Praveena Kuruva; M. Prasad
Abstract
The new tellurite glasses with chemical composition 64TeO2-15CdO-(20-x) ZnO-xLi2O-1V2O5 (x= 0, 5, 10, 15 and 20 mol %) were synthesized by traditional melt quench hardening method. The glass samples showed broad humps of typical amorphous phase in the X- ray diffraction patterns. The physical properties ...
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The new tellurite glasses with chemical composition 64TeO2-15CdO-(20-x) ZnO-xLi2O-1V2O5 (x= 0, 5, 10, 15 and 20 mol %) were synthesized by traditional melt quench hardening method. The glass samples showed broad humps of typical amorphous phase in the X- ray diffraction patterns. The physical properties of glass samples such as density (ρ), molar volume (Vm), oxygen packing density (OPD), refractive index (n), molar refractivity (Rm) and metallization parameter (M) were estimated. The Fourier transform infrared spectroscopy (FTIR) studies exhibited that replacement of ZnO by Li2O forms significantly some basic structural units of TeO4, TeO3/TeO3+1 and ZnO4. Differential scanning calorimetry (DSC) was employed to find out the glass transition temperature (Tg) and thermal stability ( ). The optical enthrallment studies exhibited that the cut-off wavelength (λ) decreases while optical energy gap (Eopt) and Urbach energy ( ) values increases with an increase an escalation of Li2O content. This tellurite glasses possess an important use such as sensor devices, storage of data system and industrial applications etc.
Research Article
G. Usha; R. Vasanthi; D. Reuben Jonathan; K.S. Ezhilarasi; M. Krishna Priya
Abstract
A novel chalcone derivative, (2E)-3-(3, 4 dimethoxy phenyl)-1-(1-hydroxy-2 naphthyl)prop-2-en-1-one (DHNP), C21H18O4, has been synthesized from the mixture of 4-hydroxy acetophenone (0.05mol) and 4-hydroxy-3-ethoxybenzaldehyde (0.05mol) by Claisen-Schmidt reaction mechanism. The structural ...
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A novel chalcone derivative, (2E)-3-(3, 4 dimethoxy phenyl)-1-(1-hydroxy-2 naphthyl)prop-2-en-1-one (DHNP), C21H18O4, has been synthesized from the mixture of 4-hydroxy acetophenone (0.05mol) and 4-hydroxy-3-ethoxybenzaldehyde (0.05mol) by Claisen-Schmidt reaction mechanism. The structural features of the grown crystal were elucidated by single X-ray diffraction (XRD) studies which confirm the title compound, belongs to the monoclinic system with the P21/n space group. Functional groups, the number of unique proton and carbon environments were identified using FT-IR, 1H, and 13C NMR spectral investigation. The optical behavior of the crystal was analyzed by UV-Vis absorption studies, and the value of the optical band gap energy (𝐸𝑔) of the crystal is found to be 3.386eV. The Photoluminescence (PL) spectrum of the compound indicates the green to yellow light emission in the visible region. By employing thermogravimetric analysis (TGA), the thermal stability of crystal and the dehydration and decomposition nature were found. The Coats and Redfern relation was applied to evaluate the kinetic and thermodynamic parameters. Mechanical properties such as the Hardness (HV), Meyer's index (n), Newtonian resistance pressure (W), load independent constant (b), and elastic stiffness constant (Cij) were calculated by performing a Vickers hardness test on the compound and found to exhibits an excellent mechanical power.