scholarly journals Towards realistic modeling of plasmonic nanostructures: the comparative study to determine the impact of optical effects on solar cell improvement

2021 ◽  
Author(s):  
Gholamhosain Haidari
Keyword(s):  
Solar Cell ◽  
Active Layer ◽  
Cell Structure ◽  
Near Field ◽  
Average Particle Size ◽  
Plasmonic Nanostructures ◽  
Average Particle ◽  
Near Field Effect ◽  
The Comparative Study ◽  
The Impact

Abstract Plasmonic structures may improve cell performance in a variety of ways. More accurate determining the optical influence, unlike ideal simulations, requires modeling closer to experimental cases. In this modeling, nonregular nanostructures were chosen and for simulation divided into three groups and some modes. For each mode, different sizes of nanoparticles were randomly selected which could result in pre-determined average particle size and standard deviation. By 3D-FDTD, the optical plasmonic properties of that mode in solar cell structure were investigated when nanostructure was added to the buffer/active layer of the organic solar cell. The far and near-field results were used to compare the plasmonic behavior, relying on the material and geometry. By detailed simulations, the Al and approximately Ag nanostructure at the interface of the ZnO/active layer can improve OSC performance optically, especially by the near-field effect. Unlike Au and relatively Ag, the Al nanostructured sample showed less parasitic absorption loss.

Influence of temperature and humidity on the angle of repose of wood bulk materials

2016 ◽  
Author(s):  
И.В. Бачериков ◽  
Б.М. Локштанов
Keyword(s):  
Field Experiments ◽  
Bulk Material ◽  
Average Particle Size ◽  
Operating Conditions ◽  
Angle Of Repose ◽  
Wood Dust ◽  
Average Particle ◽  
Bulk Materials ◽  
Technical Literature ◽  
The Impact

При проектировании открытых и закрытых хранилищ измельченных сыпучих материалов древесных материалов, таких как щепа и опилки, большое значение имеет угол естественного откоса (статический и динамический) этих материалов. В технической литературе приводятся противоречивые сведения о величине этих углов, что приводит к ошибкам при проектировании складов. В справочных данных не учитываются условия, в которых эксплуатируются емкости для хранения сыпучих материалов, свойства и состояние этих сыпучих материалов. В свою очередь, ошибки при проектировании приводят к проблемам (зависание, сводообразование, «затопление» и т. д.) и авариям при эксплуатации бункеров и силосов на производстве. В статье представлены сведения, посвященные влиянию влажности и температуры на угол естественного откоса сыпучих материалов. На основании лабораторных и натурных экспериментов, проведенных с помощью специально разработанных методик и установок, была скорректирована формула для определения углов естественного откоса (статического и динамического) для измельченных древесных материалов в зависимости от их фракционного и породного состава, влажности (абсолютной и относительной) и температуры. При помощи скорректированной формулы можно определить угол естественного откоса древесных сыпучих материалов со среднегеометрическим размером частицы от 0,5 мм до 15 мм (от древесной пыли до технологической щепы) в различных производственных условиях. Статья может быть полезна проектировщикам при расчете угла наклона граней выпускающей воронки бункеров и силосов предприятий лесной отрасли и целлюлозо-бумажной промышленности. In the design of open and closed storage warehouses chopped wood materials for bulk materials such as wood chips and sawdust, great importance has an angle of repose (static and dynamic) of these materials. In the technical literature are conflicting reports about the magnitude of these angles, which leads to errors in the design of warehouses. In the referencesdoes not take into account the conditions under which operated capacities for storage of bulk materials, and properties and condition of the bulk material. The design errors lead to problems (hanging, arching, «flooding», etc.) and accidents in the operation of hoppers and silos at the mills. The article provides information on the impact of humidity and temperature on the angle of repose of granular materials. On the basis of laboratory and field experiments, conducted with the help of specially developed techniques and facilities has been adjusted formula for determining the angle of repose (static and dynamic) for the shredded wood materials depending on their fractional and species composition, humidity (absolute and relative) and temperature. It is possible, by using the corrected formula, to determine the angle of repose of loose wood materials with average particle size of from 0.5 mm to 15 mm (wood dust to pulpchips) in various operating conditions. The article can be helpful to designers in the calculation of the angle of inclination of the funnel faces produces bunkers and silos forest industries and pulp and paper industry.

Toughening of Polypropylene-Ethylene Copolymer with Nanosized CaCO3 and Styrene-Butadiene-Styrene

2007 ◽  
Vol 121-123 ◽  
pp. 1451-1454
Author(s):  
Jian Feng Chen ◽  
Guo Quan Wang ◽  
Xiao Fei Zeng ◽  
Hong Ying Zhao
Keyword(s):  
Average Particle Size ◽  
Average Particle ◽  
Single Screw Extruder ◽  
Roll Mill ◽  
The Matrix ◽  
Ethylene Copolymer ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
The Impact ◽  
Butadiene Styrene

Nanocomposites of nanosized-CaCO3/polypropylene-ethylene copolymer (PPE) and nanosized CaCO3/ PPE/ styrene-butadiene-styrene (SBS) were prepared by using two-roll mill and single screw extruder. The average particle size of nanosized CaCO3 was determined to be about 30 nm. By adding nanosized CaCO3 into PPE matrix, the toughness of the matrix improves significantly. At nanosized CaCO3 content of 12 phr (parts per hundred PPE resin by weight), the impact strength of CaCO3/PPE at room temperature reaches 61.6 KJ/m2, which is 3.02 times that of unfilled PPE matrix. In addition, the synergistic toughening effect of nanosized CaCO3 and SBS particles on PPE matrix was investigated.

scholarly journals Water-Dispersible Phytosterol Nanoparticles: Preparation, Characterization, and in vitro Digestion

2022 ◽  
Vol 8 ◽  
Author(s):  
Ao Li ◽  
Aixia Zhu ◽  
Di Kong ◽  
Chunwei Wang ◽  
Shiping Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Soybean Lecithin ◽  
Average Particle Size ◽  
Soy Protein Isolate ◽  
In Vitro Digestion ◽  
Bimodal Distribution ◽  
Average Particle ◽  
Food Ingredients ◽  
The Impact

For improving solubility and bioaccessibility of phytosterols (PS), phytosterol nanoparticles (PNPs) were prepared by emulsification–evaporation combined high-pressure homogenization method. The organic phase was formed with the dissolved PS and soybean lecithin (SL) in anhydrous ethanol, then mixed with soy protein isolate (SPI) solution, and homogenized into nanoparticles, followed by the evaporation of ethanol. The optimum fabrication conditions were determined as PS (1%, w/v): SL of 1:4, SPI content of 0.75% (w/v), and ethanol volume of 16 ml. PNPs were characterized to have average particle size 93.35 nm, polydispersity index (PDI) 0.179, zeta potential −29.3 mV, and encapsulation efficiency (EE) 97.3%. The impact of temperature, pH, and ionic strength on the stability of fabricated PNPs was determined. After 3-h in vitro digestion, the bioaccessibility of PS in nanoparticles reached 70.8%, significantly higher than the 18.2% of raw PS. Upon freeze-drying, the particle size of PNPs increased to 199.1 nm, resulting in a bimodal distribution. The solubility of PS in water could reach up to 2.122 mg/ml, ~155 times higher than that of raw PS. Therefore, this study contributes to the development of functional PS-food ingredients.

scholarly journals Effect of adding TiO2 nanoparticles on the SEM morphology and mechanical properties of conventional heat-cured acrylic resin

2019 ◽  
Vol 13 (3) ◽  
pp. 234-240
Author(s):  
Elnaz Moslehifard ◽  
Mahmood Robati Anaraki ◽  
Saeed Shirkavand
Keyword(s):  
Impact Strength ◽  
Tio2 Nanoparticles ◽  
Cross Sections ◽  
Average Particle Size ◽  
Acrylic Resin ◽  
Mechanical Tests ◽  
Average Particle ◽  
Sem Images ◽  
Tio2 Nps ◽  
The Impact

Background. The current study evaluated the compressive, flexural and impact strengths of heat-cured acrylic resins reinforced by TiO2 nanoparticles (NPs). Methods. TiO2 NPs were provided and characterized using scanning electron microscopy (SEM) to determine their morphology and crystalline structure. For three mechanical tests, 12 acrylic resin groups (n=9), totaling 108 specimens, were prepared using a special mold for each test, with TiO2 nanoparticle contents of 0, 0.5, 1 or 2 wt% in different groups. After curing, the compressive, flexural and impact strengths of the specimens were examined according to ISO 1567. Results. In the SEM and XRD study of TiO2 NPs, anatase was identified as the major crystalline phase followed by rutile (average particle size: 20.4 nm). SEM images showed that the nanocomposite with 1 wt% NPs had a more homogenized blend. 1 wt% TiO2 nanocomposite exhibited a higher, but non-significant, impact strength compared to the controls. ANOVA showed significant differences in the impact and flexural strengths between nanocomposites with various contents of TiO2 NPs. Conclusion. The nanocomposite with 1 wt% TiO2 NPs exhibited fewer micro-pores and micro-cracks in the SEM cross-sections. A non-significant increase was also observed in the impact strength with TiO2 NPs at 1 wt%. Further increase in TiO2 NPs decreased both the impact and flexural strengths. The compressive strength of the heat-cured acrylic resin was not affected by the incorporation of NPs.

Enhancement of Intrinsic Carrier Concentration in the Active Layer of Solar Cell Using Indium Nitride Quantum Dot

2015 ◽  
Vol 793 ◽  
pp. 435-439 ◽  
Author(s):  
M.A. Humayun ◽  
M.A. Rashid ◽  
F. Malek ◽  
S.B. Yaakob ◽  
A.Z. Abdullah ◽  
...  
Keyword(s):  
Solar Cell ◽  
Quantum Dot ◽  
Carrier Concentration ◽  
Density Of States ◽  
Active Layer ◽  
Cell Structure ◽  
Indium Nitride ◽  
Effective Density ◽  
Intrinsic Carrier Concentration ◽  
Solar Cell Structure

This paper presents the improvement of intrinsic carrier concentrations in the active layer of solar cell structure using Indium Nitride quantum dot as the active layer material. We have analyzed effective density of states in conduction band and valance band of the solar cell numerically using Si, Ge and InN quantum dot in the active layer of the solar cell structure in order to improve the intrinsic carrier concentration within the active layer of the solar cell. Then obtained numerical results were compared. From the comparison results it has been revealed that the application of InN quantum dot in the active layer of the device structure improves the effective density of states both in conduction band and in the valance band. Consiquently the intrinsic carrier concentration has been improved significently by using InN quantum dot in the solart cell structure.

scholarly journals Modeling of Miniemulsion Polymerization of Styrene with Macro-RAFT Agents to Theoretically Compare Slow Fragmentation, Ideal Exchange and Cross-Termination Cases

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 320 ◽  
Author(s):  
Dries Devlaminck ◽  
Paul Van Steenberge ◽  
Marie-Françoise Reyniers ◽  
Dagmar D’hooge
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Miniemulsion Polymerization ◽  
Monomer Conversion ◽  
Water Soluble ◽  
Explicit Calculation ◽  
Average Particle ◽  
Intermediate Radical ◽  
Raft Agent ◽  
The Impact

A 5-dimensional Smith-Ewart based model is developed to understand differences for reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization with theoretical agents mimicking cases of slow fragmentation, cross-termination, and ideal exchange while accounting for chain length and monomer conversion dependencies due to diffusional limitations. The focus is on styrene as a monomer, a water soluble initiator, and a macro-RAFT agent to avoid exit/entry of the RAFT leaving group radical. It is shown that with a too low RAFT fragmentation rate coefficient it is generally not afforded to consider zero-one kinetics (for the related intermediate radical type) and that with significant RAFT cross-termination the dead polymer product is dominantly originating from the RAFT intermediate radical. To allow the identification of the nature of the RAFT retardation it is recommended to experimentally investigate in the future the impact of the average particle size (dp) on both the monomer conversion profile and the average polymer properties for a sufficiently broad dp range, ideally including the bulk limit. With decreasing particle size both a slow RAFT fragmentation and a fast RAFT cross-termination result in a stronger segregation and thus rate acceleration. The particle size dependency is different, allowing further differentiation based on the variation of the dispersity and end-group functionality. Significant RAFT cross-termination is specifically associated with a strong dispersity increase at higher average particle sizes. Only with an ideal exchange it is afforded in the modeling to avoid the explicit calculation of the RAFT intermediate concentration evolution.

Electro-Optical Simulation Of In Ultra-Thin Photonic Crystal Amorphous Silicon Solar Cells

2019 ◽  
Vol 5 (2) ◽  
pp. 10-21
Author(s):  
Abdelhak Merabti ◽  
Abdelkader Bensliman ◽  
Mahmoud Habab
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Photonic Crystal ◽  
Electric Field ◽  
Active Layer ◽  
Conversion Efficiency ◽  
Cell Structure ◽  
Photovoltaic Performance ◽  
Optical Simulation ◽  
Geometrical Parameters

Hydrogenated amorphous Si (a-Si:H) is an important solar cell material. The critical problem in the a-Si:H-based photovoltaic cell is increasing the conversion efficiency. To overcome the difficulty,  higher conversion efficiency demands a longer optical path  to increase optical absorption. Thus, a light trapping  structure is needed to obtain more efficient absorption. In this context, we propose a complete solar cell structure for which a 1D grating is etched into the ultrathin active absorbing layer of a one-dimensional "CP 1D" photonic crystal a-Si: H characterized by the optimal parameters: period a = 480 nm, a filling factor ff = 50% and a depth d = 150 nm. This was selected by varying the CP1D parameters to maximize the absorption integrated into the active layer. CP1D is suggested as an intermediate layer in the solar cell concentration system. This study allowed us to model the optical and electrical behavior of a CP1D solar cell. After optimization of the geometrical parameters (period and fill factor ... etc.), we concluded that the CP1D led to greater optical gains than for their unstructured equivalent. The simulation clearly illustrates that the electric field strongly affects the electro-optical characteristics of the devices studied, and that it is clear that 1D PC solar cells as active layer have exhibited a high electric field distribution. We have focused on the net on the effect of the active layer and its beneficial role in the sense of expressing the photovoltaic performance of the devices.

scholarly journals Monodispersed ZnO Nanoparticles and Their Use in Heterojunction Solar Cell

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Dinesh Patidar ◽  
Anusaiya Kaswan ◽  
N. S. Saxena ◽  
Kananbala Sharma
Keyword(s):  
Particle Size ◽  
Solar Cell ◽  
Ethylene Glycol ◽  
Zno Nanoparticles ◽  
Ultrasonic Treatment ◽  
Room Temperature ◽  
Power Conversion ◽  
Average Particle Size ◽  
Hexagonal Wurtzite Structure ◽  
Average Particle

Monodispersed ZnO nanoparticles have been synthesised in ethylene glycol medium using zinc acetate and sodium hydroxide at room temperature through ultrasonic treatment. The monodispersed ZnO nanoparticles were characterized by XRD, TEM, SEM, and optical spectroscopy. The results indicate that ZnO shows the hexagonal wurtzite structure having 8 nm average particle size with the band gap of 3.93 eV. ZnO nanoparticles blended with P3HT show the improvement in the interchains and intrachains ordering as compared to pure P3HT. The power conversion efficiency of P3HT/ZnO solar cell is found to be 0.88%, which is comparable with the result obtained by other researchers.

Mechanical Properties of AA 5754 Hybrid Metal Matrix Composite Fabricated through Rheo-Squeeze Casting

2020 ◽  
Vol 979 ◽  
pp. 10-15
Author(s):  
K. Sekar ◽  
K. Jayakumar
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Metal Matrix ◽  
Squeeze Casting ◽  
Base Alloy ◽  
Average Particle Size ◽  
Casting Process ◽  
Matrix Alloy ◽  
Average Particle ◽  
The Impact

Hybrid metal matrix composites (MMCs) were prepared with AA 5754 as matrix and B4C (fixed with 1 wt.% and average particle size as 25 μm) and Al2O3 reinforcements (varied from 0.5 to 2 wt. % with the interval of 0.5 and average particle size as 50 nm) using Rheo-squeeze casting process. Microstructure images were taken to observe the uniform distribution of reinforcement particles on the matrix alloy. The tensile strength for AA 5754 with 1 wt.% B4C and 2 wt.% Al2O3 hybrid composite showed higher value compared to base alloy and other composites. The wt. % of Al2O3 in the composite is increased to 2 %, the tensile strength and compressive strength were also increased due to combined Rheo-squeeze casting. AA 5754 reinforced with 1 wt.% B4C and 1.5 wt.% Al2O3 MMC indicated the Impact strength value of 30 Joules which is higher than AA 5754 matrix alloy and other compositions.

Mechanical retention – Influence of filler floc size and grammage of the fibre web

2012 ◽  
Vol 27 (2) ◽  
pp. 202-207 ◽  
Author(s):  
Karin Athley ◽  
Lars Granlöf ◽  
Daniel Söderberg ◽  
Mikael Ankerfors ◽  
Göran Ström
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Pilot Trial ◽  
Average Particle ◽  
Paper Machine ◽  
Quartz Particle ◽  
Drainage Time ◽  
Fibre Layer ◽  
Filler Retention ◽  
The Impact

Abstract An investigation of the impact of particle size on the mechanical retention of particles in a fibre network has been conducted. The particles used were five sets of quartz particle fractions having fairly narrow particle size distributions with average particle size ranging from a few μm to around 100 μm. The particles were used to model flocculated filler aggregates as part of a larger study of the effect of pre-flocculation on mechanical retention. Pre-flocculation of the filler is a possible strategy to increase the filler content of paper without deterioration of strength properties. A modified laboratory hand sheet former, known as the Rapid Drainage Device (RDD) was used. The major modification consisted of a long pipe that acted as a suction leg, which provides a dewatering vacuum at the same level as on a paper machine. The experimental results showed that mechanical filler retention increased linearly with particle size and grammage of the fibre layer above a critical grammage which depended on particle size. The linear relation was also seen in a pilot scale trial on the FEX pilot-paper machine at Innventia. During this trial fine paper was produced using pre-flocculated filler where the mean particle size of the flocs and fibres was measured in the flow to the headbox. The results from this pilot trial show that mechanical retention is an important part of the total filler retention. Drainage time and therefore drainage resistance increased with the grammage of the fibre layer and amount of quartz particle added. Drainage time, compared at total grammage (i.e. the sum of fibre and quartz particle grammage) was lowest for a fraction of medium-sized particles, with a median size of 35 mm. There was no obvious effect on retention or drainage resistance of a change in the dewatering pressure from 27.5 to 41.5 kPa.

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