The fractional PID controllers tuned by genetic algorithms for expansion turbine in the cryogenic air separation process

Ovaj rad se bavi realizacijom jednog novog algoritma PID upravljanja zasnovanog na računu necelobrojnog reda (fractional calculus) u proizvodnji tehničkih gasova, odnosno u procesu separacije utečnjenog vazduha. Proizvodnja utečnjenog vazduha niskog pritiska je po prvi put bila uvedena od strane Kapice gde se ekspanzija odvijala u gasnoj turbini. Za primenu u sintezi upravljanja ulazne temperature i protoka vazduha u ekspanzionoj turbini, potrebno je odrediti odgovarajuće diferencijalne jednačine kriogenog procesa mešanja dva gasa na različitim temperaturama na ulazu u ekspanzionu turbinu. Pri tome, odgovarajući model je linearizovan i dekuplovan gde su primenjeni istovremeno klasični PID kao i PIβDα kontroleri necelobrojnog reda da bi se procenio kvalitet predloženog novog upravljanja datim procesom. Skup optimalnih parametara datih kontrolera se postiže primenom optimizacione procedure bazirane na genetskim algoritmima minimizovanjem odgovarajućeg kriterijuma optimalnosti. Naš metod se fokusira u okviru kriterijuma optimalnosti na smanjenje preskoka, vreme smirenja i minimizaciju integralne greške. Simulacije sprovedene u vremenskom domenu pokazuju bolje performance optimalnog PIβDα kontrolera u odnosu na klasični optimalni PID kontroler.This paper deals with the design of a new algorithm of PID control based on fractional calculus (FC) in production of technical gases, i.e. in a cryogenic air separation process. Production of low pressure liquid air was first introduced by P.L. Kapitsa and involved expansion in a gas turbine. For application in the synthesis of the control law, for the input temperature and flow of air to the expansion turbine, it is necessary to determine the appropriate differential equations of the cryogenic process of mixing of two gaseous airflows at different temperatures before entrance to the expansion turbine. Thereafter, the model is linearized and decoupled and consequently classical PID and fractional order PIβDα controllers are taken to assess the quality of the proposed technique. A set of optimal parameters of these controllers are achieved through the genetic algorithm optimization procedure by minimizing a cost function. Our design method focuses on minimizing performance criterion which involves IAE, overshoot, as well as settling time. A time-domain simulation was used to identify the performance of PIβDα controller with respect to a traditional optimized PID controller

The fractional PID controllers tuned by genetic algorithms for expansion turbine in the cryogenic air separation process

Ovaj rad se bavi realizacijom jednog novog algoritma PID upravljanja zasnovanog na računu necelobrojnog reda (fractional calculus) u proizvodnji tehničkih gasova, odnosno u procesu separacije utečnjenog vazduha. Proizvodnja utečnjenog vazduha niskog pritiska je po prvi put bila uvedena od strane Kapice gde se ekspanzija odvijala u gasnoj turbini. Za primenu u sintezi upravljanja ulazne temperature i protoka vazduha u ekspanzionoj turbini, potrebno je odrediti odgovarajuće diferencijalne jednačine kriogenog procesa mešanja dva gasa na različitim temperaturama na ulazu u ekspanzionu turbinu. Pri tome, odgovarajući model je linearizovan i dekuplovan gde su primenjeni istovremeno klasični PID kao i PIβDα kontroleri necelobrojnog reda da bi se procenio kvalitet predloženog novog upravljanja datim procesom. Skup optimalnih parametara datih kontrolera se postiže primenom optimizacione procedure bazirane na genetskim algoritmima minimizovanjem odgovarajućeg kriterijuma optimalnosti. Naš metod se fokusira u okviru kriterijuma optimalnosti na smanjenje preskoka, vreme smirenja i minimizaciju integralne greške. Simulacije sprovedene u vremenskom domenu pokazuju bolje performance optimalnog PIβDα kontrolera u odnosu na klasični optimalni PID kontroler.This paper deals with the design of a new algorithm of PID control based on fractional calculus (FC) in production of technical gases, i.e. in a cryogenic air separation process. Production of low pressure liquid air was first introduced by P.L. Kapitsa and involved expansion in a gas turbine. For application in the synthesis of the control law, for the input temperature and flow of air to the expansion turbine, it is necessary to determine the appropriate differential equations of the cryogenic process of mixing of two gaseous airflows at different temperatures before entrance to the expansion turbine. Thereafter, the model is linearized and decoupled and consequently classical PID and fractional order PIβDα controllers are taken to assess the quality of the proposed technique. A set of optimal parameters of these controllers are achieved through the genetic algorithm optimization procedure by minimizing a cost function. Our design method focuses on minimizing performance criterion which involves IAE, overshoot, as well as settling time. A time-domain simulation was used to identify the performance of PIβDα controller with respect to a traditional optimized PID controller

Assignment of the NV0 575 nm zero-phonon line in diamond to a 2E-2A2 transition

The time-averaged emission spectrum of single nitrogen-vacancy defects in diamond gives zero-phonon lines of both the negative charge state at 637 nm (1.945 eV) and the neutral charge state at 575 nm (2.156 eV). This occurs through photo-conversion between the two charge states. Due to strain in the diamond the zero-phonon lines are split and it is found that the splitting and polarization of the two zero-phonon lines are the same. From this observation and consideration of the electronic structure of the nitrogen-vacancy center it is concluded that the excited state of the neutral center has A2 orbital symmetry. The assignment of the 575 nm transition to a 2E - 2A2 transition has not been established previously.Comment: 5 pages, 5 figure

Peculiarities of x-ray fluorescent definition of ion-implanted Fe in Si single crystals

The technique of definition of iron concentration in a surface layer of Si(100) is developed by use of spectrometer Spectroscan-U. The measurements of intensity of X-ray fluorescent line FeKα as a function of turn of initial crystal Si(100) in an azimuthal plane are executed. The results of analysis of the diffraction maxima are used for numerical modelling of angular intensity dependencies obtained for Si implanted by Fe. The experimental calibration equations allowing to define Fe concentration on the parameters of azimuthal angular intensity dependence of the analytical line are obtained. The behaviour of X-ray energy spectrum of the initial Si in the range of wave lengths 0.19-0.20 nm depending on an azimuthal angle is considered

Complete conversion between one and two photons in nonlinear waveguides: Theory of dispersion engineering

High-efficiency photon-pair production is a long-sought-after goal for many optical quantum technologies, and coherent photon conversion (CPC) processes are promising candidates for achieving this. We show theoretically how to control coherent conversion between a narrow-band pump photon and broadband photon pairs in nonlinear optical waveguides by tailoring frequency dispersion for broadband quantum frequency mixing. We reveal that complete deterministic conversion as well as pump-photon revival can be achieved at a finite propagation distance. We also find that high conversion efficiencies can be realised robustly over long propagation distances. These results demonstrate that dispersion engineering is a promising way to tune and optimise the CPC process. © 2022 The Author(s). Published by IOP Publishing Ltd on behalf of the Institute of Physics and Deutsche Physikalische Gesellschaft.Australian Research Council, ARC: DE180100070, DP160100619, DP190100277, FT170100399; Ministry of Education and Science of the Russian Federation, Minobrnauka: AAAA-A18-118020190095-4The authors acknowledge the support by the Australian Research Council (DE180100070, DP160100619, DP190100277). NKL is funded by the Australian Research Council Future Fellowship (FT170100399). Batalov S V acknowledges support by the Ministry of Education and Science of the Russian Federation (the theme ‘Quantum’, No. AAAA-A18-118020190095-4)

Low temperature studies of the excited-state structure of Nitrogen-Vacancy color centers in diamond

We report a study of the 3E excited-state structure of single nitrogen-vacancy (NV) defects in diamond, combining resonant excitation at cryogenic temperatures and optically detected magnetic resonance. A theoretical model of the excited-state structure is developed and shows excellent agreement with experimental observations. Besides, we show that the two orbital branches associated with the 3E excited-state are averaged when operating at room temperature. This study leads to an improved physical understanding of the NV defect electronic structure, which is invaluable for the development of diamond-based quantum information processing.Comment: 4 pages, 4 figure

Evaluation of the CD40 receptor-ligand system in the patients with atrial fibrillation of non-valvular genesis

Thromboembolic syndrome is the most dangerous complication of atrial fibrillation which develops in about 8-15% of cases, thus presuming the role of persisting left-heart thrombosis in presence of anticoagulant therapy in some patients. When activated, the blood platelets express multiple copies of CD40L on their membrane. Hence, the soluble form of CD40 ligand is considered a marker of platelet activation and pathogenic processes associated with increased activity of the thrombotic system. Our aim was to study the content of CD40, soluble CD40 ligand and thrombomodulin in the patients with atrial fibrillation of non-valvular genesis receiving anticoagulant therapy, discerning those with a history of thrombotic complications, and the cases with atrial fibrillation, however, free of thrombotic complications. The study group included 22 healthy volunteers and 60 patients diagnosed with atrial fibrillation who received anticoagulant therapy, of whom 21 patients have developed thrombotic complications in the course of adequate anticoagulant therapy. Quantitative assays of CD40, soluble CD40 ligand and soluble thrombomodulin were performed by enzyme immunoassay using Core Facility “Medical Genomics”, Tomsk National Research Medical Center. Concentration of soluble CD40 ligand in both groups of the patients with atrial fibrillation significantly exceeded appropriate values in the group of healthy volunteers. CD40L content was increased in the group of patients with thrombotic complications against the group of patients without thrombotic complications. Thrombomodulin content in blood serum was decreased in the patients with thrombotic complications, as compared to both thrombosis-free patients, and to practically healthy volunteers. The study of CD40/CD40L system and thrombomodulin showed that the patients with thrombotic complications exhibited higher serum level of soluble CD40L, with a simultaneous decrease of thrombomodulin, a physiological anticoagulant. A comparative analysis of the CD40/sCD40L system showed increased concentrations of the biomarkers in females, when compared to males

Structure, impurity composition, and photoluminescence of mechanically polished layers of single-crystal silicon

The introduction of optically active defects (such as atomic clusters, dislocations, precipitates) into a silicon single crystal using irradiation, plastic deformation, or heat treatment has been considered a possible approach to the design of silicon-based light-emitting structures in the near infrared region. Defects were introduced into silicon plates by traditional mechanical polishing. The changes in the defect structure and the impurity composition of damaged silicon layers during thermal annealing (TA) of a crystal were examined using transmission electronic microscopy and x-ray fluorescence. Optical properties of the defects were studied at 77 K using photoluminescence (PL) in the near infrared region. It has been shown that the defects generated by mechanical polishing transform into dislocations and dislocation loops and that SiO2 precipitates also form as a result of annealing at temperatures of 850 to 1000°C. Depending on the annealing temperature, either oxide precipitates or dislocations decorated by copper atoms, which are gettered from the crystal bulk, make the predominant contribution to PL spectra. © 2005 Pleiades Publishing, Inc