experimental parameters
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2022 ◽  
Vol 19 (2) ◽  
pp. 025203
Author(s):  
S P Kulik ◽  
K S Kravtsov ◽  
S N Molotkov

Abstract The analysis of the security of quantum key distribution systems with respect to an attack with nondemolishing measurement of the number of photons (photon number splitting—PNS attack) is carried out under the assumption that in the communication channel in each parcel there is a pure Fock state with a different number of photons, and the distribution of states by number of photons has Poisson statistics. In reality, in the communication channel in each parcel there are not individual Fock states, but a pure coherent state with a random phase—a superposition of Fock states with different numbers of photons. The paper analyzes the necessary experimental resources necessary to prepare individual Fock states with a certain number of photons from the superposition of Fock states for a PNS attack. Optical schemes for implementing such an attack are given, and estimates of experimental parameters at which a PNS attack is possible are made.


Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 458
Author(s):  
Oscar P. Yanchatuña Aguayo ◽  
Lynda Mouheb ◽  
Katherine Villota Villota Revelo ◽  
Paola A. Vásquez-Ucho ◽  
Prasad P. Pawar ◽  
...  

Bio-nanotechnology has emerged as an efficient and competitive methodology for the production of added-value nanomaterials (NMs). This review article gathers knowledge gleaned from the literature regarding the biosynthesis of sulfur-based chalcogenide nanoparticles (S-NPs), such as CdS, ZnS and PbS NPs, using various biological resources, namely bacteria, fungi including yeast, algae, plant extracts, single biomolecules, and viruses. In addition, this work sheds light onto the hypothetical mechanistic aspects, and discusses the impact of varying the experimental parameters, such as the employed bio-entity, time, pH, and biomass concentration, on the obtained S-NPs and, consequently, on their properties. Furthermore, various bio-applications of these NMs are described. Finally, key elements regarding the whole process are summed up and some hints are provided to overcome encountered bottlenecks towards the improved and scalable production of biogenic S-NPs.


2022 ◽  
Vol 9 ◽  
Author(s):  
Martin Kessler ◽  
Roberto Rinaldi

Mechanochemistry utilizes mechanical forces to activate chemical bonds. It offers environmentally benign routes for both (bio) organic and inorganic syntheses. However, direct comparison of mechanochemistry results is often very challenging. In mechanochemical synthetic protocols, ball mill setup (mechanical design and grinding vessel geometry) in addition to experimental parameters (milling frequency, duration, ball count and size) vary broadly. This fact poses a severe issue to further progress in this exciting research area because ball mill setup and experimental parameters govern how much kinetic energy is transferred to a chemical reaction. In this work, we address the challenge of comparing mechanochemical reaction results by taking the energy dose provided by ball mills as a unified metric into account. In this quest, we applied kinematic modeling to two ball mills functioning under distinct working principles to express the energy dose as a mathematical function of the experimental parameters. By examining the effect of energy dose on the extent of the mechanocatalytic depolymerization (MCD) of lignocellulosic biomass (beechwood), we found linear correlations between yield of water-soluble products (WSP) and energy dose for both ball mills. Interestingly, when a substrate layer is formed on the grinding jar wall and/or grinding medium, a weak non-linear correlation between water-soluble products yield and energy dose is identified. We demonstrate that the chemical reaction’s best utilization of kinetic energy is achieved in the linear regime, which presents improved WSP yields for given energy doses. In the broader context, the current analysis outlines the usefulness of the energy dose as a unified metric in mechanochemistry to further the understanding of reaction results obtained from different ball mills operating under varied experimental conditions.


Desalination ◽  
2022 ◽  
Vol 519 ◽  
pp. 115309
Author(s):  
Jun-Hwan Bang ◽  
Soo-Chun Chae ◽  
Kyungsun Song ◽  
Seung-Woo Lee

2022 ◽  
Vol 92 (3) ◽  
pp. 353
Author(s):  
М.А. Ирзак ◽  
С.А. Нечаев

Numerical modeling of propagation and absorption of fast waves (helicons) with frequency 200 MHz in 2D inhomogeneous plasma of the spherical tokamak Globus-M2 was carried out with 2D full-wave code. Toroidal effects, poloidal magnetic field and the actual shape of the flux surfaces were taken into account. The full wave electric field and RF power absorption profiles were computed by solving plasma wave equation with electron Landau damping term. The modeling demonstrated a fairly high efficiency of helicons absorption in the bulk plasma within a wide range of experimental parameters. The waves propagate to the inner regions of the plasma column and are mainly absorbed there; less than 20% of RF energy returns back to the plasma periphery.


2021 ◽  
Vol 23 (6) ◽  
pp. 481-486
Author(s):  
K. Darques ◽  
A. Tounzi ◽  
A. Benabou ◽  
S. Shihab ◽  
J. Korecki ◽  
...  

In high power electrical machines, the leakage magnetic flux due to end windings induces eddy currents in clamping devices. However, it is quite difficult to quantify these losses. In order to study the effect of different clamping materials and the impact of the magnetization direction, an experimental mock-up composed of a stator and a clamping plate has been developed. An axial coil generates a circumferential magnetic flux in the stator core at different frequencies. Eddy current losses in the clamping plates are deduced from a power balance by subtracting Joule losses and iron losses from the total measured losses. Iron losses are deduced from 3D FE calculations while the impact of the frequency on B(H) curve is taken into account. Losses in the clamping device are then analyzed depending on experimental parameters.


2021 ◽  
Author(s):  
Xin-Miao Zhu ◽  
Min Cui ◽  
Yu Wang ◽  
Tian-Jing Yu ◽  
Jin-Xiang Deng ◽  
...  

Abstract Based on the transport equation of the semiconductor device model for 0.524 eV GeSn alloy and the experimental parameters of the material, thermal-electricity conversion performance governed by GeSn diode has been systematically studied in its normal and inverted structure. For the normal p+/n (n+/p) structure, it is demonstrated here that an optimal base doping N d(a) = 3 (7)×1018 cm-3 is observed, and the superior p+/n structure can reach the higher performance. To reduce material consumption, an economical active layer can be comprised of 100-300 nm emitter and 3-6 μm base to attain comparable performance as that for the optimal configuration. The results can offer many useful guidelines for the fabrication of economical GeSn thermophotovoltaic devices.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Atinafu G/Mariam ◽  
Abebe Diro ◽  
Tsegaye Girma Asere ◽  
Demelash Jado ◽  
Fekadu Melak

Fluoride health problem is a great concern worldwide, most often as a result of groundwater intake. Thus, determination of fluoride is vital to take appropriate measures upon fluoride contamination of water. Potentiometric method of analysis is reliable for the determination of fluoride in various samples. In addition, spectroscopic methods are found important to quantify fluoride levels from water; however, several factors hinder its easier determination. Among the bottlenecks, the use of toxic chemicals and tedious steps in preparing chemicals (e.g., SPADNS method) are to mention a few. In this study, a spectrophotometric method was developed for the determination of fluoride from groundwater using Eriochrome Black T (EBT) as a spectroscopic reagent. Experimental parameters that influence the determination of fluoride including ligand type, kinetics, pH, and ligand-to-metal ratio were assayed. Evaluation of fluoride levels showed that Beer–Lambert’s law is obeyed in the range of 0.3–5.0 mg/L at 544 nm. The calibration curve, resulting in good linearity (R2 = 0.9997), was considered during quantitative analysis of the samples and in the spiking analysis. The limits of detection (LOD) and quantification (LOQ) of the method were found to be 0.19 and 0.64 mg/L, respectively. The precision studied in terms of intraday and interday at three concentration levels showed less than 5.4% RSD. Applicability of the method was investigated by analyzing groundwater samples spiked with fluoride standards, and satisfactory recoveries in the range of 98.18–111.4 were demonstrated. The developed spectrophotometric method has been successfully applied for fluoride determinations in groundwater samples. Thus, it could be used as an attractive alternative for the determination of fluoride from groundwater.


2021 ◽  
Vol 9 ◽  
Author(s):  
Yang Li ◽  
Houjun Gong ◽  
Yunwen Hu ◽  
Shengxing Yang ◽  
Yong Li ◽  
...  

Stratification morphology of a molten pool under severe reactor accident was investigated by the CESEF experimental facility. The experimental scale was 5,000 g, the atomic ratio of U/Zr was 1.5, the content of stainless steel was 10%, and the oxidation degree of Zr was 40–100%. It was shown that the molten pool was obviously stratified within the range of experimental parameters; one was a metal layer, and the other was an oxide layer. The layered morphology of the molten pool was different with the composition of different corium. With the decrease in the Zr oxidation degree, the metal layer moved downward in the molten pool, and the molten pool would overturn. The main elements in the oxide layer were U, Zr, and O, and the content of stainless steel was low. The main element in the metal layer was stainless steel and contained a certain amount of U and Zr.


2021 ◽  
Vol 11 (40) ◽  
pp. 168-169
Author(s):  
Denise Lessa Aleixo ◽  
Leoni Vilano Bonamin ◽  
Silvana Marques De Araujo

Introduction: The use of homeopathic medicines has increased, once traditional medicines sometimes do not produce the desired effects and because side effects sometimes compromise the treatment. In recent years, research on homeopathy has clearly developed, both in the implementation of more consistent methodologies and in the description of the data and published methods, improvement are still required in these matters. The acknowledgment of homeopathy depends on the credibility of the groups researching this topic Objective: list and criticize articles highlighting main effects, schedule of treatment and potencies used in different animals models. Material and Methods: A review of articles published since 2000 in journals indexed in the PubMed/Scielo databases was performed. Keywords used were parasitosis/homeopathy and parasitosis/ultra-diluted, in English and Portuguese. Specialized journals such as Homeopathy, International Journal of High Dilution Research, and Brazilian Homeopathic Journal were also used. The contents of each issue of these journals were examined for the "Use of highly diluted medication in parasitic infections." Results and Discussion: Thirty nine papers have been gathered. The methodology of the articles surveyed did not meet the requirements listed in the REHBaR[1]. Thirty seven reports have shown the benefits/effects of highly diluted medicine in the treatment of infectious diseases. In models where experimental conditions are carefully controlled, the conclusions follow the same pattern as those observed in the treatment of farm animals, where, even without completely controlled conditions, clinical result is positive. In fourteen reports using the same model, eight where animals were treated in a constant and prolonged way shown a better result, compared with six reports in which animals were treated for a short period of time, receiving a single daily dose. Several authors have conducted clinical trials using commercial formulas, which do not always provide their composition and/or dynamization, making it difficult to reproducing the experiment. In some of the articles, it was not mentioned if the experiments were repeated at least twice. Conclusions: In parasitic infections, the effect of homeopathic medications is still controversial, and the experimental parameters for evaluation shoud be carefully chosen to avoid isolated analyses of data. Researchers should consider results regarding environmental and sanitary conditions of the animal as a whole. The improvement of techniques and expansion of knowledge about highly diluted medicines may lead to a viable alternative to treat parasitic infections. Precise and detailed descriptions will contribute to advances in the use of homeopathy, so that the wider community can benefit, in practice, from these findings. Keywords: homeopathy, parasitic infections, CAM (Complementary and Alternative Medicine). Reference [1] Lüdtke R, Musial F, Wijk R, Witt C, Baumgartner S. Reporting experiments in homeopathic basic research (REHBaR) – A detailed guideline for authors. Homeopathy. 2009; 98:287-298.


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