- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Bulk luminescent solar concentrators based on organic-inorganic CH3NH3PbBr3 perovskite fluorophores
摘要： In this paper, we report characterization and performance results of lead bromide perovskite luminescent solar concentrator. CH3NH3PbBr3 fluorophores are synthesized by sonication method and examined by their X-ray diffraction pattern and scanning electron microscopy. Synthesized perovskite shows excitonic absorption at 524 nm and PL emission peak located at 532 nm with a Stokes shift around 8 nm. Micron-sized fluorophores are dissolved in prepared solutions and uniformly embedded in PMMA host with 0.006–0.120%wt concentration. Then, Fabricated devices are cut into 50 × 30 × 5 mm cuboid shapes and placed in a mirror surrounded configuration with an attached photovoltaic cell. Fabricated device is put under standard AM1.5 illumination and the output spectrum from the concentrator is acquired. Re-absorption in the samples is also measured by variable optical path method, showing red-shifts up to 13 nm in the output spectrum. Spatially resolved photo-luminescence maps and optical efficiencies are also presented for each sample. Plus, a Monte-Carlo ray tracing algorithm is developed to assist better understanding the experimental results. Stability of fabricated samples are evaluated under high intensity UV illumination, reporting efficiency reduction around 15% after 24 h. Finally, Comparing current-voltage characterization of the attached photovoltaic cell reveals optimized efficiency enhancement in the 0.04%wt sample above 65%.
关键词： Perovskites,Monte-Carlo simulation,Re-absorption,Luminescent solar concentrators,Photovoltaic conversion efficiency,Solar cells
更新于2025-11-14 15:30:11
-
Development and characterization of air kerma cavity standard
摘要： Ionization chambers are the most common detectors for precise measurements such as these required in radiation protection and radiotherapy. This paper presents the design, development and characterization of a new graphite–walled cavity ionization chamber used as a primary standard for air kerma rate for 137Cs and 60Co gamma radiation of the Central Office of Measures (GUM). The paper describes particularly methods for a cavity volume determination and the cavity volume relation to an electric field. The various correction factors to be applied to the primary standards and their determination by experimental and Monte Carlo methods are discussed. Re–evaluation of the standard according to the recommendations of ICRU90 Report for the new primary standard is presented. A typical uncertainty budget for the graphite-walled cavity ionization chamber as a primary standard for air kerma rate for gamma radiation is presented and results of internal comparisons between standards are summarized and discussed.
关键词： ionization chamber,air kerma cavity standard,Monte Carlo simulation,gamma radiation
更新于2025-09-23 15:23:52
-
The Monte Carlo Simulation of Secondary Electrons Excitation in the Resist PMMA
摘要： The Monte Carlo method was used to simulate the process of secondary electrons excitation in resist PMMA with Mott cross section and dielectric function model. By analyzing the characteristics of secondary electrons excitation in the resist PMMA, and the simulation of secondary electrons energy range, we hold the opinion that the secondary electrons can not be ignored in the electron beam lithography.
关键词： Monte Carlo simulation,electron beam lithography (EBL),dielectric function,secondary electrons
更新于2025-09-23 15:23:52
-
[IEEE 2018 15th International Conference on the European Energy Market (EEM) - Lodz (2018.6.27-2018.6.29)] 2018 15th International Conference on the European Energy Market (EEM) - Optimized Operational Management of an EV Sharing Community Integrated with Battery Energy Storage and PV Generation
摘要： Sharing schemes are emerging in residential and business sectors to reduce the purchase and operation cost of individuals. This paper proposes a framework to support the operational management of a shared EV fleet. An optimization algorithm is developed to coordinate the charging and reservation assignment using mixed integer programming. The integration with local PV production and battery storage is taken into account. A booking algorithm is also developed to determine whether a reservation can be accepted or not. Monte Carlo simulation is performed in the case study to demonstrate an application of the proposed framework with the Swedish travel patterns. The result provides an overview about the utilization rate of the fleet with different number of EVs, which can support the investment decision of an EV sharing community. The result also shows that the EVs and battery are effectively coordinated to minimize the total cost, satisfy the reservations and comply with grid limits.
关键词： PV generation,battery storage,optimization,Monte Carlo simulation,operational management,electric vehicle sharing,mixed integer programming
更新于2025-09-23 15:23:52
-
[IEEE 2018 International Multi-Conference on Industrial Engineering and Modern Technologies (FarEastCon) - Vladivostok, Russia (2018.10.3-2018.10.4)] 2018 International Multi-Conference on Industrial Engineering and Modern Technologies (FarEastCon) - Numerical Simulation of Low-Coherence Radiation Propagation in Turbid Media and Structural Image Reconstruction in Endoscopic Optical Coherence Tomography with Allowance for Speckle Fluctuations
摘要： A method of Monte Carlo simulation of low-coherence radiation propagation in turbid media with consideration of speckle noise (the result of mutual interference of secondary spherical waves) is described. The process of photon propagation within investigated object, such as biological tissue, includes the following steps: the photon injection, mean free path determination, the verification of the fulfillment of the boundary condition, the absorption and scattering. Structural image reconstruction in optical coherence tomography (OCT) with consideration of speckle fluctuations is made by summation the statistical weight of the beam coming out of the investigated object inside the detector area with the intensity of a series of pixels of the current A-scan. The key feature of the presented method is the description of the investigated object geometry. Three-dimensional array of voxels combined into parallelograms, and the border cross checking is carried out by using an improved Smith algorithm. The described method can be used to obtain high-quality endoscopic structural OCT images of body cavities and tracts (diagnosis of the respiratory tract, cardiovascular system, gastrointestinal tract, genitourinary system, etc.).
关键词： coherence probing depth,Monte Carlo simulation,optical coherence tomography,voxel based model,speckle fluctuations,structural image
更新于2025-09-23 15:22:29
-
A Monte Carlo based dosimetric characterization of Esteya <sup>?</sup> , an electronic surface brachytherapy unit
摘要： The purpose of this work is threefold: First, to obtain the phase-space of an electronic brachytherapy (eBT) system designed for surface skin treatments. Second, to explore the use of some efficiency enhancing (EFEN) strategies in the determination of the phase-space. Third, to use the phase-space previously obtained to perform a dosimetric characterization of the Esteya eBT system. Methods: The Monte Carlo study of the 69.5 kVp x-ray beam of the Esteya? unit (Elekta Brachytherapy, Veenendaal, The Netherlands) was performed with PENELOPE2014. The EFEN strategies included the use of variance reduction techniques and mixed Class II simulations, where transport parameters were fine-tuned. Four source models were studied varying the most relevant parameters characterizing the electron beam impinging the target: the energy spectrum (mono-energetic or Gaussian shaped), and the electron distribution over the focal spot (uniform or Gaussian shaped). Phase-spaces obtained were analyzed to detect differences in the calculated data due to the EFEN strategy or the source configuration. Depth dose curves and absorbed dose profiles were obtained for each source model and compared to experimental data previously published. Results: In our EFEN strategy, the interaction forcing variance reduction (VRIF) technique increases efficiency by a factor ~ 20. Tailoring the transport parameters values (C1 and C2) does not increase the efficiency in a significant way. Applying a universal cutoff energy EABS of 10 keV saves 84% of CPU time whilst showing negligible impact on the calculated results. Disabling the electron transport by imposing an electron energy cutoff of 70 keV (except for the target) saves an extra 8% (losing in the process 1.2% of the photons). The Gaussian energy source (FWHM = 10%, centered at the nominal kVp, homogeneous electron distribution) shows characteristic K-lines in its energy spectrum, not observed experimentally. The average photon energy using an ideal source (mono-energetic, homogeneous electron distribution) was 36.19 ± 0.09 keV, in agreement with the published measured data of 36.2 ± 0.2 keV. The use of a Gaussian-distributed electron source (mono-energetic) increases the penumbra by 50%, which is closer to the measurement results. The maximum discrepancy of the calculated percent depth dose with the corresponding measured values is 4.5% (at the phantom surface, less than 2 % beyond 1 mm depth) and 5% (for the 80% of the field) in the dose profile. Our results agree with the findings published by other authors and are consistent within the expected Type A and B uncertainties. Conclusions: Our results agree with the published measurement results within the reported uncertainties. The observed differences in PDD, dose profiles and photon spectrum come from three main sources of uncertainty: inter-machine variations, measurements and Monte Carlo calculations. It has been observed that a mono-energetic source with a Gaussian electron distribution over the focal spot is a suitable choice to reproduce the experimental data.
关键词： simulation efficiency,Monte Carlo simulation,electronic brachytherapy,surface treatment,dosimetry,x-ray source
更新于2025-09-23 15:21:21
-
Uncertainty budgets of major ozone absorption cross sections used in UV remote sensing applications
摘要： Detailed uncertainty budgets of three major ultraviolet (UV) ozone absorption cross-section datasets that are used in remote sensing application are provided and discussed. The datasets are Bass–Paur (BP), Brion–Daumont–Malicet (BDM), and the more recent Serdyuchenko–Gorshelev (SG). For most remote sensing application the temperature dependence of the Huggins ozone band is described by a quadratic polynomial in temperature (Bass–Paur parameterization) by applying a regression to the cross-section data measured at selected atmospherically relevant temperatures. For traceability of atmospheric ozone measurements, uncertainties from the laboratory measurements as well as from the temperature parameterization of the ozone cross-section data are needed as input for detailed uncertainty calculation of atmospheric ozone measurements. In this paper the uncertainty budgets of the three major ozone cross-section datasets are summarized from the original literature. The quadratic temperature dependence of the cross-section datasets is investigated. Combined uncertainty budgets is provided for all datasets based upon Monte Carlo simulation that includes uncertainties from the laboratory measurements as well as uncertainties from the temperature parameterization. Between 300 and 330 nm both BDM and SG have an overall uncertainty of 1.5 %, while BP has a somewhat larger uncertainty of 2.1 %. At temperatures below about 215 K, uncertainties in the BDM data increase more strongly than the others due to the lack of very low temperature laboratory measurements (lowest temperature of BDM available is 218 K).
关键词： uncertainty budgets,Monte Carlo simulation,temperature dependence,UV remote sensing,ozone absorption cross sections
更新于2025-09-23 15:21:21
-
Unimolecular FRET sensors: Simple linker designs and properties
摘要： Protein activation and deactivation is central to a variety of biological mechanisms, including cellular signaling and transport. Unimolecular fluorescent resonance energy transfer (FRET) probes are a class of fusion protein sensors that allow biologists to visualize using an optical microscope whether specific proteins are activated due to the presence nearby of small drug-like signaling molecules, ligands or analytes. Often such probes comprise a donor fluorescent protein attached to a ligand binding domain, a sensor or reporter domain attached to the acceptor fluorescent protein, with these ligand binding and sensor domains connected by a protein linker. Various choices of linker type are possible ranging from highly flexible proteins to hinge-like proteins. It is also possible to select donor and acceptor pairs according to their corresponding F¨oster radius, or even to mutate binding and sensor domains so as to change their binding energy in the activated or inactivated states. The focus of the present work is the exploration through simulation of the impact of such choices on sensor performance.
关键词： FRET Microscopy,Fusion Proteins,Diagnostics,Monte Carlo Simulation,Coarse Graining,Cellular Signaling
更新于2025-09-23 15:21:01
-
Study of the germanium dead layer influence on HP(Ge) detector efficiency by Monte Carlo simulation
摘要： Introduction The dead layer thickness provided by the manufacturer increases with the aging of the HPGe detector; the increase of dead layer thickness leads to the decrease in the detector’s ef?ciency, not only due to gamma rays attenuation in the dead layer but also due to the reduction of the active volume of the detector. Purpose In this work, the dead layer in?uence on HPGe detector ef?ciency was studied by Monte Carlo simulation. Materials and methods The detector model was developed using Monte Carlo N Particle (MCNP5) code for adjustment of the dead layer thickness; the adjustment was performed according to a speci?c irradiation con?guration by collimation approach using three reference point sources: 241Am (59.5 keV), 137Cs (661.6 keV) and 60Co (1173.2 keV; 1332.5 keV). Result The calculated ef?ciencies were compared to the measured intrinsic ef?ciency ones for these point sources; a good agreement between Monte Carlo and measurements results was found after the experimental validation. Conclusion The results con?rm the variation in the dead layer thickness according to aging of the detector; the average change of dead layer is in order of 1.30 ± 0.05 mm after 9 years.
关键词： Dead layer thickness,Detector ef?ciency,Monte Carlo simulation,Point sources,HPGe detector
更新于2025-09-23 15:21:01
-
Nanostructures for Cancer Therapy || Dose enhancement effect in radiotherapy: adding gold nanoparticles to tumor in cancer treatment
摘要： The rationale of radiation dose enhancement due to gold nanoparticle addition in radiotherapy is revealed from the basic particle interactions to Monte Carlo simulation. Our review of different radiobiological studies on Monte Carlo, cell line, and preclinical model confirms that cancer cell kill definitely benefits from the dose enhancement when gold nanoparticles were added. Moreover, such dose enhancement depends on the size, shape, and concentration of the gold nanoparticle, as well as the type and energy of the radiation beams. It is concluded that adding gold nanoparticles to the tumor can enhance both the dose and contrast at the target in radiotherapy.
关键词： radiotherapy,cancer treatment,Monte Carlo simulation,gold nanoparticles,dose enhancement
更新于2025-09-23 15:21:01