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关键词： CCD-RSM   Optimization   Natural pigment   Antioxidant capacity   DPPH radical scavenging  

摘要： The use of low-toxic, hypoallergenic, and environmentally friendly natural pigments has increased. With growing interest in health, research on natural extracts containing beneficial substances for the human body is actively underway. In this study, natural pigments were extracted from sprout barley using a solvent extraction method and CCD-RSM was used to optimize the extraction process. The experiment's independent variables included extraction temperature, alcohol/ultra-pure volume ratio, and extraction time. The response variables were set to achieve a target chromaticity (L = 45, a = -35, b = 45), and to maximize DPPH radical scavenging activity evaluating the antioxidant capacity. The statistical significance of the main effect, interaction effect, and effect on the response value was evaluated and analyzed through the F and P values for the regression equation variables calculated using RSM optimization. Additionally, the reliability of the experiment was also confirmed through the P values of the probability plot graph. The extraction conditions for optimizing the four reaction values are 76.1 vol.% alcohol/ultra pure water volume ratio, an extraction temperature of 52.9 degrees C , and an extraction time of 49.6 min. Under these conditions, the theoretical values of the reaction values are L = 45.4, a = -36.8, and b = 45.0 DPPH radical scavenging activity = 30.9%. When the actual experiment was conducted under these optimal extraction conditions and analyzed, the measured values were L = 46.2, a = -36.1, and b = 48.2, and antioxidant capacity = 31.1% with an average error rate of 2.9%.

关键词： nanotechnology   manufacturing   optimization   TIG welding aluminum   central composite design   CCD   response surface methodology  

摘要： New and innovative technologies have expanded the quality and applications of aluminum welding in the maritime, aerospace, and automotive industries. One such technology is the addition of nanoparticles to aluminum matrices, resulting in improved strength, operating temperature, and stiffness. Furthermore, researchers continue to assess pertinent factors that improve the microstructure and mechanical characteristics of aluminum welding by enabling the optimization of the manufacturing process. Hence, this research explores alternatives, namely cost-effective aluminum welding fillers reinforced with niobium diboride nanoparticles. The goal has been to improve weld quality by employing multi-objective optimization, attained through a central composite design with a response surface model. The model considered three factors: the amount (weight percent) of nanoparticles, melt stirring speed, and melt stirring time. Filler hardness and porosity percentage served as response variables. The optimal parameters for manufacturing this novel filler for the processing conditions studied are 2% nanoparticles present in a melt stirred at 750 rpm for 35.2 s. The resulting filler possessed a 687.4 MPA Brinell hardness and low porosity, i.e., 3.9%. Overall, the results prove that the proposed experimental design successfully identified the optimal processing factors for manufacturing novel nanoparticle-reinforced fillers with improved mechanical properties for potential innovative applications across diverse industries.

关键词： Detectors   Optical imaging   Radiometry   Imaging   Charge coupled devices   Payloads   Temperature measurement   CCD detector   dark current   earth-observing satellites   in-orbit focal plane array temperature   optical imaging system   radiometric performance  

摘要： Space optical imaging systems are subject during their in-orbit lifetime to many damaging effects caused by aging and harsh conditions (temperature and radiation) in the low Earth orbit environment threatening consequently instruments' performance and durability. In particular, the time-dependent increase of the detector's thermally-induced dark current due to temperature rises at the Focal-Plane-Array (FPA) may well lead to an unacceptable degradation in the radiometric performance of the optical imager. The aim of this work is to establish measures for the mitigation of FPA thermal effects on the radiometric performance and calibration of a space-borne optical imaging payload through FPA design optimization and in-orbit operation of the optical imaging payload. The temperature rises at FPA during long strip acquisition are first modeled, and results are used to assess the consequent effect on radiometric performance by predicting time-variable changes in detector offset due to thermal leakage current. Then, based on the outcomes of the thermal model and offset signals calculation, recommendations regarding FPA design and the operation of the optical imaging payload are made to mitigate the effect of FPA temperature rises on the imager's radiometric performance. Finally, in-flight FPA temperature measurements taken during on-orbit operation are compared with the FPA thermal model results. The modeling results exhibit a strong correspondence with the measurements acquired during the flight. The dark current derived from in-flight data demonstrates that the time-dependent increase in the detector offset signals induced by temperature rises at FPA during image acquisition is negligible, validating the proposed thermal mitigation strategy.

关键词： Dielectric-barrier discharge   Response surface methodology   n-Hexane   Non-thermal plasma   Volatile organic compounds  

摘要： In this study, a Dielectric-Barrier Discharge (DBD) plasma reactor was used for the degradation of n-hexane from an air stream. a Central Composite Design (CCD) based Response Surface Methodology (RSM), (CCD-RSM) was utilized to explore the effects of experimental parameters including discharge voltage, initial concentration, gas flow rate, relative humidity and their interactions on the reactor performance. The proposed optimization model showed a satisfactory correlation between the predicted and actual results. According to the results, discharge voltage was the most significant parameter affecting the removal efficiency, CO2 selectivity and the level of O3 and NOx formation, whereas energy yield was mainly influenced by gas flow rate and initial concentration. At optimized conditions (discharge voltage of 8.5 kV, inlet concentration of 94.3 ppm, relative humidity of 55 % and gas flow rate of 733.16 ml/min with combined desirability of 0.921), removal efficiency of 92.57 %, CO2 selectivity of 58.87 %, energy efficiency of 0.25 g/kWh, O3 formation of 140.88 mg/m3 and NOx formation of 122.46 ppm were obtained. Water vapour significantly increased the removal efficiency and CO2 selectivity as well as reduced O3 and NOx. The results revealed that the CCD-RSM provided the optimum process parameters for the Non-Thermal Plasma (NTP) system.

关键词： Activated carbon-based photocatalyst   Nanocomposite   Environmental remediation   Wastewater Treatment   Doxycycline  

摘要： Reducing electron-hole pair recombination rate under visible light and preventing alpha-Fe2O3/WO3 nanoparticle aggregation enhances the photocatalytic efficiency. Herein, a novel heterojunction-activated carbon-based photocatalyst (alpha-Fe2O3/WO3/AC) was successfully synthesized from Rosa Canina seeds and characterized by PL, EIS, Photocurrent, ESR, XPS, LC-MS, FTIR, XRD, SEM, EDS-map, TEM, and BET analyses. Investigating the influence of significant parameters, including impregnation ratio (1-5), activation temperature (400-600 degrees C), and alpha-Fe2O3/WO3 loading (10-90 wt.%) by RSM method resulted in optimal photocatalyst synthesis (50 wt.%: FeW/AC3-500) evidenced by its capability for doxycycline degradation. The maximum doxycycline degradation (98.01 %) was achieved under optimal conditions with a degradation rate constant of 0.03 min(-1). Trapping experiments revealed that (OH)-O-center dot and O-center dot(2)- played crucial roles in photocatalysis. The possible doxycycline degradation pathway of (50 wt.%: FeW/AC3-500) photocatalyst is proposed. Based on the transient photocurrent measurements and EIS results, the 50 wt.% FeW/AC3-500 composite exhibited a significant enhancement in photocatalytic activity, which can be attributed to the efficient speed of electron-hole separation. Overall, an innovative approach was introduced to design an efficient AC-based photocatalytic process, which enhances the performance of wastewater treatment and environmental remediation.

关键词： in-plasma beta-decay studies   plasma diagnostics   electron cyclotron resonance ion sources   X-ray imaging   single-photon-counted images   high dynamical range analysis   X-ray spatially resolved spectroscopy  

摘要： PANDORA (Plasmas for Astrophysics Nuclear Decays Observation and Radiation for Archaeometry) is an INFN project aiming at measuring, for the first time, possible variations in in-plasma beta -decay lifetimes in isotopes of astrophysical interest as a function of thermodynamical conditions of the in-laboratory controlled plasma environment. Theoretical predictions indicate that the ionization state can dramatically modify the beta -decay lifetime (even of several orders of magnitude). The PANDORA experimental approach consists of confining a plasma able to mimic specific stellar-like conditions and measuring the nuclear decay lifetime as a function of plasma parameters. The beta -decay events will be measured by detecting the gamma -ray emitted by the daughter nuclei, using an array of 12 HPGe detectors placed around the magnetic trap. In this frame, plasma parameters have to be continuously monitored online. For this purpose, an innovative, non-invasive multi-diagnostic system, including high-resolution time- and space-resolved X-ray analysis, was developed, which will work synergically with the gamma -rays detection system. In this contribution, we will describe this multi-diagnostics system with a focus on spatially resolved high-resolution X-ray spectroscopy. The latter is performed by a pin-hole X-ray camera setup operating in the 0.5-20 keV energy domain. The achieved spatial and energy resolutions are 450 mu m and 230 eV at 8.1 keV, respectively. An analysis algorithm was specifically developed to obtain SPhC (Single Photon-Counted) images and local plasma emission spectrum in High-Dynamic-Range (HDR) mode. Thus, investigations of image regions where the emissivity can change by even orders of magnitude are now possible. Post-processing analysis is also able to remove readout noise, which is often observable and dominant at very low exposure times (ms). Several measurements have already been used in compact magnetic plasma traps, e.g., the ATOMKI ECRIS in Debr

关键词： 光纤通信  

ISBN: (纸本)9787115611895

摘要： 本书全面地介绍了光纤通信技术的概念、原理及实用系统。全书共分9章，内容包括概述、光导纤维、光纤通信器件、光纤通信系统、SDH及MSTP、WDM与OTN、PTN/IPRAN、城域光网络、全光网络。由于光纤通信系统具有低传输损耗和大传输带宽的特点，因此它是高速数据业务的理想传输通道。在介绍光纤通信基本概念和工作原理的基础上，重点介绍光纤通信的最新技术。

关键词： 无线电通信  

ISBN: (纸本)9787030768438

摘要： 本书深入讨论了量化信息融合相关理论及在无线传感器网络中的应用情况。主要内容包括：均匀量化测量与融合、自适应量化测量与融合、量化新息与融合、分布式量化航迹融合、信道感知目标跟踪及跨层优化、对等网络中分布式协同目标跟踪等。最后开发了无线传感器网络目标跟踪硬件平台，以验证所涉方法在相关应用场景中的实际性能。

关键词： 智能传感器  

ISBN: (纸本)9787030781215

摘要： 本书以作者在分布式智能传感器网络安全数据处理技术多年的研究工作为基础，总结并梳理了面向分布式智能传感器网络位置和数据隐私保护技术的最新进展，从网络位置隐私保护和网络数据隐私保护两个方面着重介绍分布式智能传感器网络安全数据处理技术研究的脉络和发展。从源节点位置隐私保护出发，扩展到三维无线网络溯源攻击防御，解决异构无线传感器网络中针对恶意节点的数据安全传输问题，研究分布式智能传感器网络数据的安全存储、层次加密技术，进而解决分布式智能传感器网络数据安全共享问题，最后通过将网络位置隐私保护技术和网络数据隐私保护技术应用于密文检索领域，分析并探讨了相关技术应用中的研究范式和应用模式，以促进分布式智能传感器网络安全数据处理技术的发展。

关键词： 2μm   有机金属法   光沉积法   硫化铅(PbS)量子点   光纤放大器  

摘要： 随着光通信业务量的快速增长，对宽带光放大器的需求不断增加。因此，有必要研制一种覆盖新波段的量子点光纤放大器。本文首次通过实验实现了基于硫化铅（PbS）量子点的2 μm光纤放大器。通过改进的有机金属法，制备出尺寸分布在9.2 nm附近的PbS量子点，并用光沉积法将其沉积在光纤锥区。用976 nm激光二极管（LD）泵浦渐逝波激发，光纤放大器在1900-2100 nm的波长区域具有宽带增益，增益达可达10.1 dB。