Filters
total: 622
filtered: 425
Search results for: double%20inverted%20pendulum
-
Cross-linking of polymer films using phenol-formaldehyde resins with different functional groups
PublicationWell-know phenol-formaldehyde resins are used in the production of press-materials, glues, protective coating, mastics. They take a special place among known oligomers because the products based on them are characterized by a low cost and a series of positive properties. Aim of the work: to show the possibility to create polymeric films based on epoxy resins and modified phenol-formaldehyde resins, which contain unsaturated double...
-
Absolute configurations of C34 and C35 of antibiotic niphimycin A
PublicationThe relative configurations of four stereogenic centers of the C33-C42 fragment of niphimycin A were assigned as 2S*, 3R*, 4S* and 6S*, based upon (1)H NMR analysis with double-quantum filtered COSY and nuclear Overhauser spectroscopy experiments. These data were then correlated with absolute configurations at C36 and C38 of niphimycin A, which were declared previously as 36S and 38S [3]. This allowed for the assignment of the...
-
Absolute configurations of C34 and C35 of antibiotic niphimycin A
PublicationThe relative configurations of four stereogenic centers of the C33-C42 fragment of niphimycin A were assigned as 2S*, 3R*, 4S* and 6S*, based upon 1H NMR analysis with double-quantum filtered COSY and nuclear Overhauser spectroscopy experiments. These data were then correlated with absolute configurations at C36 and C38 of niphimycin A, which were declared previously as 36S and 38S [3]. This allowed for the assignment of the absolute...
-
The influence of thermal treatment on electrocatalytic properties of Mn-Co nanofilms on nickel foam toward oxygen evolution reaction activity
PublicationThis work evaluates electrodeposited and differently treated Mn-Co catalysts for their oxygen evolution reaction activity. Catalysts are evaluated in the as-deposited and heat treated state: after 350 C and 600 C. Results show that the highest electrochemical activity is obtained for the as-deposited Mn-Co oxyhydroxide, which possibly possess a layered double hydroxide structure. After the heat treatment process, especially after...
-
Modelling of planar movement dynamics of upper limb
PublicationThe original model describing planar movement dynamics of upper limb is presented. The upper limb is modelled as two-joints system loaded by external forces and internal forces of striated skeletal muscles. A behaviour of each muscle is modelled as a system composed of serially linked rheologic fragments that have different mechanical properties. These muscle models allow us to simulate a behaviour of short fusiform muscle (3DOF...
-
From phosphanylphosphaalkenes to coordination copper and silver polymers containing P–P bonds
PublicationThis study was focused on the activation of the C[double bond, length as m-dash]P bond via reactions of Ph2C[double bond, length as m-dash]P-PtBu2 (1) with 1,6-hexanediol and selected dithiols (1,4-butanedithiol, 1,4-benzenedithiol and 1,4-benzenedimethanethiol). These reactions proceed according to a 1,2-addition mechanism, providing new compounds with formulas {(Ph)2(H)C-P-PtBu2}{μ2-(O-(CH2)6-O)}{tBu2P-P-C(H)(Ph)2} (2), {(Ph)2(H)C-P-PtBu2}{μ2-(S-(CH2)4-S)}{tBu2P-P-C(H)(Ph)2}...
-
Cross-border transmission line configuration influence on the electrical power and energy billing process
PublicationIn 2015 a connection between the Polish and Lithuanian power systems become fully operational. The connection consists of a 400 kV double circuit transmission line and a back-to-back HVDC substation located on the Lithuanian side. A magnetic couplings between the circuits of the transmission line cause that during power transmission a different values of active power losses are observed in both circuits. This situation may cause...
-
Four Level Diode-Clamped Back-To-Back Converter with Active DC Link Voltage Control
PublicationThis article presents the design and control of 4L-DC back-to-back converter. To solve the DC link voltage balancing problem in four-level converter a new three-level double chopper topology based on PO-PWM modulation was designed and successfully tested. Also, the paper describes two phase space vector pulse width modulation 2P-SVPWM based on the shape function of finite elements. The control structure with modified Dead-Beat...
-
Bonding in Phosphanylphosphinidene Complexes of Transition Metals and their Correlation with Structures, 31 P NMR Spectra, and Reactivities
PublicationTheoretical studies of the bonding interactions and most important properties are carried out for isolable phosphanylphosphinidene complexes of transition metals. Three main types of phosphanylphosphinidene complexes are distinguished, based on the way in which the phosphanylphosphinidene ligand bonds to the metal center: (i) side-on complexes of platinum, where the R2Pβ–Pα ligand mimics structural features of free singlet phosphanylphosphinidenes...
-
Photoelectron spectroscopy of brominated derivative of pyrimidine: 2-bromopyrimidine
PublicationIn this study the brominated derivative of pyrimidine, 2-bromopyrimidine, was investigated by photoelectron spectroscopy. Outer valence photoelectron spectra recorded at 21.22, 45 and 100 eV photon energy for this compound are presented. The recorded spectra have a higher resolution than that previously reported in the literature. The bromine 3d and 3p edge photoelectron spectra have also been recorded in a photon impact experiment...
-
Pikselowy cyfrowy układ CDS przeznaczony do przetwornika obrazu CMOS
PublicationW artykule zaproponowano cyfrowy układ CDS (Correlated Double Sampling) przeznaczony do przetwornika obrazu CMOS. Układ różni się od klasycznych rozwiązań tym, że dwie pamięci przechowujące próbki sygnału wizyjnego zastąpiono jednym licznikiem rewersyjnym. Dzięki tej modyfikacji możliwa jest znaczna redukcja powierzchni układu CDS i umieszczenie go w każdym pikselu przetwornika obrazu CMOS. System został zaprojektowany i przesymulowany...
-
Pikselowy cyfrowy układ CDS przeznaczony do przetwornika obrazu CMOS
PublicationW artykule zaproponowano cyfrowy układ CDS (Correlated Double Sampling) przeznaczony do przetwornika obrazu CMOS. Układ różni się od klasycznych rozwiązań tym, że dwie pamięci przechowujące próbki sygnału wizyjnego zastąpiono jednym licznikiem rewersyjnym. Dzięki tej modyfikacji możliwa jest znaczna redukcja powierzchni układu CDS i umieszczenie go w każdym pikselu przetwornika obrazu CMOS. System został zaprojektowany i przesymulowany...
-
VUV irradiation studies of plasmid DNA in aqueous solution
PublicationInteractions of VUV light and DNA samples in aqueous solutions are reported. The damage induced by such radiation is quantified by monitoring both loss of supercoiled DNA and formation of single and double strand breaks using agarose gel electrophoresis. Irradiations were performed using synchrotron VUV photons of 130, 150, 170 and 190 nm. VUV irradiation experiments revealed enhanced damage upon irradiation with 170 nm photons...
-
Low-Coherence Interferometer with Nanocrystalline Diamond Films with Potential Application to Measure Small Biological Samples
PublicationThe study investigates a case of a low-coherence fiber-optic Fabry–Prerot interferometer with a nanocrystalline diamond (NCD) mirror. The method of achieving double density of interference fringes is proposed by the application of birefringent material in the cavity of the interferometer. It can be used to reduce sample volume in comparison to conventional interferometers. The use of a biocompatible diamond mirror makes it specifically...
-
Electromagnetic Problems Requiring High-Precision Computations
PublicationAn overview of the applications of multiple-precision arithmetic in CEM was presented in this paper for the first time. Although double-precision floating-point arithmetic is sufficient for most scientific computations, there is an expanding body of electromagnetic problems requiring multiple-precision arithmetic. Software libraries facilitating these computations were described, and investigations requiring multiple-precision...
-
Design and experimental investigations of a cylindrical microjet heat exchanger for waste heat recovery systems
PublicationCompact heat exchangers have more and more applications in many areas, including the HVAC, food and petrochemical industry. This paper describes the development of heat exchanger technology for waste heat recovery (WHR) from a range of processes. Case-study testing shows that the proposed heat exchanger can successfully enhance heat transfer and recover waste heat in a range of applications making them economically, environmentally and...
-
Dominant Pathways of Adenosyl Radical-Induced DNA Damage Revealed by QM/MM Metadynamics
PublicationBrominated nucleobases sensitize double stranded DNA to hydrated electrons, one of the dominant genotoxic species produced in hypoxic cancer cells during radiotherapy. Such radiosensitizers can therefore be administered locally to enhance treatment efficiency within the solid tumor while protecting the neighboring tissue. When a solvated electron attaches to 8-bromoadenosine, a potential sensitizer, the dissociation of bromide...
-
Performance of Watermarking-based DTD Algorithm Under Time-varying Echo Path Conditions
PublicationA novel double-talk detection (DTD) algorithm based on techniques similar to those used for audio signal watermarking was introduced by the authors. The application of the described DTD algorithm within acoustic echo cancellation system is presented. The problem of DTD robustness to time-varying conditions of acoustic echo path is discussed and explanation as to why such conditions occur in practical situations is provided. The...
-
Robustness analysis of watermarking-based dtd algorithm under time-variable echo conditions
PublicationA novel double-talk detection (DTD) algorithm based on techniques similar to those used for audio signal watermarking was introduced by the authors. The application of the described DTD algorithm within acoustic echo cancellation system is presented. The problem of DTD robustness to time-varying conditions of acoustic echo path is discussed and explanation as to why such conditions occur in practical situations is provided. The...
-
Elimination of impulsive disturbances from archive audio files – comparison of three noise pulse detection schemes
PublicationThe problem of elimination of impulsive disturbances (such as clicks, pops, ticks, crackles, and record scratches) from archive audio recordings is considered and solved using autoregressive modeling. Three classical noise pulse detection schemes are examined and compared: the approach based on open-loop multi-step-ahead signal prediction, the approach based on decision-feedback signal prediction, and the double threshold approach,...
-
EHV transmission lines wires location on line operation issues - case studies
PublicationTransmission lines towers construction affects the line parameters and influences on its operation in the future. Misguided design of the tower can lead to serious problems such as overvoltages, electric arc extinction difficulties, voltage asymmetry, resonance phenomena or increasing of magnetic field near the line. The paper points out those threats on example of 400 kV double circuit overhead transmission line with shunt reactors....
-
Experimental study of the post tensioned prestressed concrete corbels
PublicationThe results of experimental investigation of 6 symmetrical double prestressed corbels of variable shear span to depth ratio and variable location of prestressing bars are presented in the paper. The post ten- sioned corbels were prestressed with Macalloy 1030 bars of 25 mm in diameter. The results of the tests were compared with the cracking and load carrying capacity of corbels reinforced with passive reinforce- ment. As a result...
-
How Do Ionic Liquids Affect the Surface Structure of Titania Photocatalyst? An Electron-Trap Distribution-Analysis Study
PublicationTitanium(IV) oxide, titania, photocatalyst particles were prepared from titanium alkoxide in the presence of several kinds of ionic liquids, and it was clarified that a group of samples exhibited photocatalytic activity for phenol degradation under the irradiation of light of wavelength >400 nm higher than those of the other group of samples. Although the conventional structural analytical results could not be related to the activity,...
-
Microgrinding with single-disk lapping kinematics.
PublicationGrinding operations are carried out with a variety of tool-workpiece configurations. The selection of a grinding process for a particular application depends on part shape, part size, ease of fixture, requirements concerning the acceptable shape errors. It is evident that lapping is very effective in eliminating the waviness while surface grinding is not. Dual disk machines for the double face grinding with planetary kinematics...
-
Metody strojenia regulatorów typu PID z wykorzystaniem technologii syntezy regulatorów od stanu
PublicationUkłady sterujące typu PID są jednymi z najbardziej popularnych regulatorów wykorzystywanych w układach regulacji. W związku z tym znanych jest szereg metod doboru wartości ich parametrów (nastaw). Obok różnych metod inżynierskich czy analitycznych strojenia tego typu regulatorów, dostępne są również podejścia bazujące na optymalizacji. Wskaźnikiem jakości znajdującym w nich zastosowanie jest np. całka z kwadratu uchybu. W artykule...
-
Supercapacitors - charge redistribution and restoring voltage
PublicationThe charge in supercapacitor is stored on electrodes and in electrolyte. The charges on electrodes create the Helmholtz double layer which is formed immediately with time constant of the order of seconds, while the charge storage in electrolyte is going on with time constant of the order of hundreds seconds. When the charged supercapacitor is shorted for few seconds, the charge from electrodes is discharged while the charge in...
-
DETECTION OF DEBONDING IN STEEL BARS EMBEDDED IN CONCRETE USING GUIDED WAVE PROPAGATION
PublicationThe paper presents a non-destructive diagnostic technique based on guided wave propagation phenomenon used to assess the adhesive bonding between a steel bar and a concrete cover. Double-layered cylindrical specimens with different levels of debonding and its location were investigated. The influence of bonding length on the excitation of multiple modes of longitudinal guided waves was analysed. Numerical simulations of guided...
-
Transient States during Short-circuit in a Line Powered by UPS and its Impact on Earth Fault Loop Impedance Measurement and Power Quality
PublicationThe short-circuit in a line powered by Uninterruptible Power Supply (UPS) during different UPS operation modes is presented in the article. The transient state condition related to the short-circuit in a line fed from double conversion On-line UPS is discussed in detail. The results of the measurements of earth fault loop impedance (FLI) in circuits powered by UPS with the instruments of various manufacturers are presented. The...
-
Dissociative electron attachment and anion-induced dimerization in pyruvic acid
PublicationWe report partial cross sections for the dissociative electron attachment to pyruvic acid. A rich fragmentation dynamics is observed. Electronic structure calculations facilitate the identification of complex rearrangement reactions that occur during the dissociation. Furthermore, a number of fragment anions produced at electron energies close to 0 eV are observed, that cannot originate from single electron-molecule collisions....
-
Mathematical Approach to Assess a Human Gait
PublicationA purpose of the paper was to create a mathematical approach to assess a human gait. The scope of the study was to model a normal gait in the sagittal plane and frontal plane of the body. Applying the Newton-Euler formulation, three multibody biomechanical models were derived to describe single support phase and double support phase of the gait. To model a gait in the sagittal plane the open-close sagittal 6DOF model and the open-close...
-
Realizacja przetwornika obrazu CMOS z wbudowaną konwersją A/C i cyfrowym układem CDS
PublicationW artykule przedstawiono realizację w technologii CMOS 180 nm przetwornika obrazu z wbudowaną konwersją analogowo-cyfrową oraz z funkcją cyfrowej redukcji szumu. Przedstawiona realizacja przetwornika obrazu różni się od znanych z literatury rozwiązań tym, że układ redukcji szumu CDS (Correlated Double Sampling) umieszczono w każdym pikselu obrazu. Dzięki tej modyfikacji możliwe jest zastąpienie migawki szczelinowej przez migawkę...
-
Magnetic-field-induced electric quadrupole moments for relativistic hydrogenlike atoms: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublicationWe consider a Dirac one-electron atom placed in a weak, static, uniform magnetic field. We show that, to the first order in the strength of the external field, the only electric multipole moments, which are induced by the perturbation in the atom, are those of an even order. Using the Sturmian expansion of the generalized Dirac-Coulomb Green function we derive a closed-form expression for the electric quadrupole moment induced...
-
Defining the thermal conductivity of thermally heterogeneous hollow wall bricks used as elements for increasing the comfort of buildings
PublicationThe article presents numerical calculation analysis in the scope of determining thermal conductivity coefficientλeq[W/(m·K)] of thermally heterogeneous hollow bricks of thermally heterogeneous structure (a combinationof structural material with thermal insulation material). Numerical calculations were conducted by means ofprofessional software TRISCO-KOBRU 86, serving thermal circulation analysis in a 2D field in stationary approach.The...
-
The energy approach to fatigue crack growth of S355 steel welded specimens subjected to bending
PublicationThe study presents the results of the research on the rate of fatigue crack growth subjected to bending in the ferritic-pearlitic structure. The studies were carried out at a constant amplitude of the moment and at various values of the load ratios R and at the operating frequency of the machine of 28.4 Hz. Flat specimens made of S355 steel and with fillet welds and with double-sided blunt external notches as well as concave...
-
Molecular basis for the DNA damage induction and anticancer activity of asymmetrically substituted anthrapyridazone PDZ-7
Publicationnthrapyridazones, imino analogues of anthraquinone, constitute a family of compounds with remarkable anti-cancer activity. To date, over 20 derivatives were studied, of which most displayed nanomolar cytotoxicity towards broad spectrum of cancer cells, including breast, prostate and leukemic ones. BS-154, the most potent derivative, had IC50 values close to 1 nM, however, it was toxic in animal studies. Here, we characterize another...
-
Nowa metoda obliczania rozpływu prądów zwarciowych w przewodach odgromowych linii wysokiego napięcia
PublicationReferat przedstawia nowatorską metodę obliczania wartości prądów płynących w przewodach odgromowych w czasie zwarć, pozwalającą na dobór przewodów odgromowych pod względem wytrzymałości cieplnej. Proponowana metoda charakteryzuje się większą dokładnością i większą uniwersalnością niż powszechnie stosowane metody, pozwalając tym samym na dobór przewodów odgromowych z mniejszym ryzykiem niepewności. Prezentowana metoda obliczeniowa...
-
Modelling an accelerometer for robot position estimation
PublicationThe article describes a new model of a MEMS accelerometer for usage in inertial measurement units (IMU). Such units allow to measure orientation and location of the sensor/system and therefore can be applied for systems positioning. The main purpose of the paper is to model pertinent accelerometer functions substantial in determination of the location of the sensor by means of double integration of acceleration. The model takes...
-
Evaluation of position estimation based on accelerometer data
PublicationThe paper concerns the problem of integrating data from accelerometers. A suitable model of a MEMS accelerometer is presented which is a part of inertial measurement units (IMU). Such units allow to measure orientation as well as to localize systems. They also appear to be applicable for systems positioning. The main purpose of the paper is to discuss conditions that must be satisfied to calculate the location of the sensor by...
-
The Creation of an Antimicrobial Coating on Contact Lenses by The Use of Nanocopper
PublicationThe aim of the research was to creation an antimicrobial coating on contact lens and examine the ability of copper nanoparticles to decrease microbial adhesion and prevent the growth of bacteria. The creation was based on the immersion method in solution with dispersed nanoparticles of copper at concentration 200 pm. There were evaluated follows factors: time of immersion and base to dispersed nanoparticles. Three solutions: ethyl...
-
Extending touch-less interaction with smart glasses by implementing EMG module
PublicationIn this paper we propose to use temporal muscle contraction to perform certain actions. Method: The set of muscle contractions corresponding to one of three actions including “single-click”, “double-click” “click-n-hold” and “non-action” were recorded. After recording certain amount of signals, the set of five parameters was calculated. These parameters served as an input matrix for the neural network. Two-layer feedforward neural...
-
Microstrip four-port circulator using a ferrite coupled line section
PublicationThis paper describes an alternative configuration of a four-port circulator realized in a microstrip ferrite coupled line technology. The proposed fully planar device employs two three-port circulators consisting of a ferrite coupled line junction and T junction. Both circulators are connected through the same arm, hence, the problem of anti-parallel magnetization met in this type of circulators is avoided without the increase...
-
Influence of steel brackets supporting crane runway girders structure on the stress distribution in the brackets
PublicationThe paper presents a numerical analysis of steel brackets supporting a double-span crane runway girders. The purpose of the study was to assess the new structural solution based on the stress distribution in the brackets. In order to simplify the connection, the bottom flange of the crane runway girder is based directly on the upper flange of the bracket. As a result, the support reaction is no longer applied in the plane of the...
-
Dissociative electron attachment to benzoic acid (C7H6O2)
PublicationThe dissociative electron attachment (DEA) to benzoic acid (C6H5COOH) has been studied using an experimental crossed beam setup of a quadrupole mass spectrometer and a trochoidal electron monochromator. Relative partial cross sections for the DEA to produce negative ion fragments show the main channels for dissociation. The comparison of the present results with the ultraviolet photoelectron spectrum of benzoic acid [J. Meeks,...
-
Optimized Stress and Geometry Control of Spherical structures under Lateral Loadings
PublicationIn this paper, a numerical model of a double-layer spherical structure has been examined under lateral loadings. When the structure has been distorted due to loadings, the dislocated joints have been moved to their original positions utilizing the adjustment techniques based on the force method. Meanwhile, the members’ internal forces were kept in the desired domain. Optimization techniques were also implemented in order to minimalize...
-
Negative Poisson’s ratio from pentagons: A new auxetic structure combining three different auxetic mechanisms
PublicationA novel class of two-dimensional auxetic structures based on the pentagon motif is proposed. Their mechanical properties are investigated by combining molecular mechanics simulations with a simple three-parameter mechanical model which assumes perfectly elastic behavior. It is predicted that the proposed structures – termed as double re-entrant honeycomb – may possess unique mechanical characteristics, which include complete and...
-
Rekonstrukcja ewolucji układu przestrzennego średniowiecznego miasta i portu Szczecin Reconstruction of the Spatial Evolution of the Medieval City and Port of Szczecin
PublicationPraca rekonstruuje ewolucję układu osadniczego Szczecina w okresie od połowy VIII w. do początku XIV w., w oparciu o interpretację dostępnej literatury naukowej dotyczącej historii i archeologii Szczecina oraz metodę analizy planistycznej. Bardzo istotnym elementem opisu struktury urbanistycznej wczesnośredniowiecznego Szczecina było określenie roli i położenia portu. W wyniku analizy zmian układu przestrzennego miasta w omawianym...
-
Evaluating the position of a mobile robot using accelerometer data
PublicationThis paper analyses the problem of determining the position of a robot using an accelerometer, which is an essential part of inertial measurement units (IMU). The information gained from such a gauge, however, requires double integration of sensor data. To assure an expected effect, a mathematical model of a low-cost accelerometer of the MEMS type is derived. Moreover, in order to improve the performance of positioning based on...
-
Corrigendum to “An investigation on residual stress and fatigue life assessment of T-shape welded joints” [Eng. Fail. Anal. 141 (2022) 106685]
PublicationThis paper aims to quantitatively evaluate the residual stress and fatigue life of T-type welded joints with a multi-pass weld in different direction. The main research objectives of the experimental test were to test the residual stress by changing direction along with multiple wielding passes and determine the fatigue life of the welded joints. The result shows that compressive residual stress increases in the sample gradually...
-
Radio- and photosensitization of DNA with compounds containing platinum and bromine atoms
Publication. Irradiations of plasmid DNA by both X-rays and UV light in the presence and absence of compounds containing platinum and bromine atoms were performed in order to asses the sensitization potential of these compounds. Plasmid DNA pBR322 was incubated with platinum (II) bromide, hydrogen hexabromoplatinate (IV), hydrogen hexahydroxyplatinate (IV) and sodium hexahydroxyplatinate (IV). Incubation was followed by X-ray or UV irradiations....
-
Evaluating the mobile robot positions using accelerometer data
PublicationThis paper analyzes the problem of determining the position of a robot using an accelerometer, which is an essential part of inertial measurement units (IMU). The information gained from such a gauge, however, requires double integration of sensor data. To assure an expected effect, a mathematical model of a low-cost accelerometer of the MEMS type is derived. Moreover, in order to improve the performance of positioning based on...