Operating Conditions of the Vehicle

Ocena korelacji średniego ciśnienia tętniczego z krwawieniem śródoperacyjnym przy wolnej czynności serca w trakcie endoskopowej chirurgii zatok przynosowych

A comparison of neuronal reactions during classical and instrumental conditioning under similar conditions

12 - Performance verification of low noise, low dropout regulators: Silence of the amps

In order to extract more wind energy, the wind turbine rotor becomes larger and the tower becomes taller. With more flexibility and smaller damping, wind turbine tower is prone to vibrate in winds. Meanwhile, the tower suffers the periodic loadings caused by the rotor rotation in the operational condition. The excessive vibrations could not only significantly affect the power generation but shorten the structural life due to the fatigue as well. It is challenging to reduce the vibration caused by the rotor rotation using the passive tuned mass damper (TMD) and traditional LQR controller due to the limited effective bandwidth. Therefore, an active tuned mass damper (ATMD) using a virtual TMD algorithm is proposed to mitigate the along-wind vibration of the tower under parked and operational conditions. The virtual TMD algorithm exhibits wide effective bandwidth and only requires the acceleration information on the top of the tower or the relative displacement of the active TMD. Firstly, the aerodynamic-structure-servo coupling (ASSC) model of the wind turbine is established which considers the interaction among the aerodynamic load, structure, and servo system. Secondly, the accuracy of the ASSC model is then verified using the onshore 5 MW wind turbine by the National Renewable Energy Laboratory (NREL). Thirdly, the ATMD feedback control force is designed by the virtual TMD algorithm. Finally, the reduction effect on the along-wind vibration by the proposed controller is evaluated at both of operational and parked conditions using the ASSC model. The TMD and LQR controller are utilized for comparison. The numerical results demonstrate that tuned mass damper (TMD) system with fixed parameters becomes detuned and may loses its effectiveness at different wind speeds. In contrast, active control can suppress the vibration of wind turbines at different wind speeds. Compared to the LQR controller, the proposed controller can enhance the reduction effect of wind turbine response with smaller stroke and control force at operational conditions.

Overview Polymer Electrolyte Fuel Cell (PEFC) is expected as a new power source in automobiles with high power density and low emission. Although PEFC has many advantages compared with internal combustion engines, the cost reduction and the improvement of performance and durability are needed for its practical application. For improvement of PEFC, it is important to understand the mechanism inside it under various operating and structural conditions and to feedback into the design of membrane electrode assembly (MEA) and bipolar plate constituting fuel cell stack.In order to visualize inside PEFC, we have been developed a numerical simulation tool calculating the cell and stack performance and physical distributions and a nondestructive, real-time/space visualization technique for oxygen partial pressure in the cathode flow channel and the GDL using oxygen-sensitive luminescent dye film [1].In this study, as for the first step of our numerical modeling development, the effects of operating condition, for example, cathode flow rate on the test cell as well as commercial-sized cell and stack were investigated. Numerical Modeling Inside the fuel cell, multi-physical and multi-scale of phenomena such as multi-component gas, liquid water and heat transport inside the flow channel and the GDL, electrochemical reactions and proton/water transport in the MEA are nonlinearly coupled [2]. These phenomena require too much calculation cost to be solved in high resolution by fully 3-dimensional equations based on computed fluid dynamics (CFD), so it is necessary to apply simplified models. In our modeling, macroscopic models are applied for microscopic phenomena in the catalyst layer and electrolyte such as electrochemical reactions (HOR/ORR) and proton/water transport. And these models are coupled with multi-dimensional heat, gas and liquid water transport equations in which effective parameters such as gas diffusivity and permeability in the GDL and equivalent hydraulic diameter in the flow field of bipolar plate and the manifold of stack are included [3]. Results First of all, the performance of 25cm2test cell with single serpentine flow channel was carried out. Hydrogen and air flow rate is 300ml/min, relative humidity is 60%RH, cell temperature is 353.15K and back pressure is 1atm, respectively.The distribution of oxygen partial pressure in cathode flow channel and on the GDL surface at cathode utilization 80% (0.58 A/cm2) are shown in Figure 1 compared to the measured data by a nondestructive visualization system. The results are good agreement with the measured data and indicate that the numerical prediction of current density distribution is valid in our model.Applying the validated model, the effect of cathode flow rate on the performance of short stack with 20 cells (max. 5kW) was carried out. As for the other operating conditions, relative humidity is 50%RH, cell temperature is 343.15K and back pressure is 1.5atm, respectively. Figure 2 shows the effect of cathode utilization on the distribution of normalized in-flow rate and ORR gain for each cell at 0.5A/cm2. As cathode utilization increases, in-flow rate decreases and ORR gain increases remarkably near the dead end of stack. This is because liquid water accumulates in the flow channel and the GDL.In addition, the performance of full-scale PEFC stack for automobiles under various operating conditions will also be discussed in this meeting.

Li-ion batteries (LIBs) have been used in a variety of applications including consumer electronics, electric vehicles, space exploration, the defense sector, etc. As a result, the performance and reliability of the commercial LIBs have become extremely crucial which can be monitored by the deterioration in the charge storage over continuous charge-discharge cycling [1]. However, cycling LIBs at the nominal current rate involves excessive time and resource consumption resulting in a slow battery qualification process. Accelerated testing has been proposed to examine the reliability test and for the efficient qualification process of batteries [2]. It is conducted by increasing the operational (stress factors) conditions of the LIBs that have direct implications on the performance and cycle life of a battery. During accelerated testing, capacity deterioration and increase in impedance are recorded periodically, which serve as indicators of degradation of the batteries [3]. Batteries under consideration for the degradation process are closely monitored and the above degradation indicators are recorded at elevated levels of the operational conditions than normal. This process is known as the accelerated degradation test. In literature, there are several operational conditions that have been reported to affect the capacity fade and cycle life of a battery [1-4]. However, the C-rate and ambient temperature are the widely believed dominant factors that have a significant effect on the performance of a battery [2, 4].In this work, we will present a systematic study on the performance degradation of commercial LIBs under accelerated testing using dominant operational conditions viz. C-rate and testing ambient temperature. Capacity fading of commercial cylindrical 18650-type LIBs is monitored at 1 and 2 C-rate while maintaining the ambient temperature during testing at 25 and 35 ℃ in a thermal chamber. Capacity degradation is highly sensitive to C-rate and causes faster fading at higher current rates due to mechanical degradation of electrodes, formation of SEI layer and side reactions. Discharging at high C-rates also causes ohmic heating in the cells increasing their internal temperature which further influences the chemical reaction kinetics [4]. The ambient temperature also has a strong influence on the capacity loss due to the degeneration of the positive electrode and SEI layer formation at the negative electrode [1, 4]. Accelerated testing including the synergistic effect of the ambient temperature and C-rate on the capacity fading and performance evaluation of the commercial LIBs till the end of life or 20% capacity reduction would be presented. Post cycling analysis of the Li-ion cells, in particular, electrode materials and periodic impedance measurements would enable a better understanding of battery failure under such accelerated testing. We believe that the results of this study would pave the way to shorten the duration in the detection of a battery failure and enable an efficient battery qualification process.

An empirical study of the impacts of operating and market conditions on container-port efficiency and benchmarking

The article presents the results of measurements and statistical analysis of the variables characterizing the braking process and the work of the car's braking system in diversified operating conditions. The introductory part presents a measuring system that allows measurements of brake system operation parameters during operation. Discussed are the methodology for measuring and determining such values as the temperature of the discs, unit pressures and the slip speed at the contact of the disc and brake pad, braking pressure, vehicle speed and its longitudinal acceleration. Operational working conditions included urban driving, extra-urban and motorway driving. Based on the measurements made, histograms of measured values were developed. On the basis of the obtained results, typical temperature gains during a single braking in individual conditions were determined and the course of temperature changes during cooling of the brake discs was analyzed. The ranges of typical values of the tested parameters for individual operating conditions were generalized and compared with the values characteristic for emergency braking, which can be considered as maximum values.

A new Floating Sub-Structure concept has been developed for Floating Offshore Wind Turbine (FOWT). It consists of a floating tubular sub-structure connected with tendons to a counterweight providing pendulum-restoring forces. The whole floating system is anchored with six low-tension mooring lines. Model tests were carried out in wave basin test facilities at Ecole Centrale de Nantes to provide insight into hydrodynamic behavior of the system under operational and extreme wave conditions. Two installation depths were studied: intermediate and deeper water depth configurations with 75 and 150 meters water depth respectively. Two wind turbine capacities were tested: 8MW and 12MW. Responses of the system were investigated under different irregular wave conditions: operational condition with significant wave height Hs = 4 m and two extreme wave conditions with significant wave heights Hs=8m and 14 m. Sensitivity tests were also performed for various wave periods Tp (Tp = 8, 12 and 16 seconds). Results of these tests demonstrate that the floater is extremely stable with very low pitch motions as well as low vertical & horizontal accelerations both in operational and extreme wave conditions. Detailed results are presented in this paper. This stable dynamic behavior is obtained because natural periods of the floater are far away from wave spectrum peak and it thus leads to low dynamic loads in the mooring lines. This beneficial seakeeping feature and the possibility of accommodating even larger wind turbines with minor modifications on the floater design make the proposed FOWT a relevant concept for the upcoming offshore floating wind market.

Numerical simulation of gas–heat–water distribution characteristics of Ammonia–Hydrogen fuel cell

Plated coatings are one of the most extensively applied, yet expensive and deficient methods of protection from corrosion, providing high decorative quality and special properties of parts and constructions used in vessels. The technology of galvanic coating presents a health risk and is an ecologically dangerous process. Thus, the optimization of the coating's thickness to exclude the losses under the use of excessive thickness, and to prevent the necessity to restore the coatings after the covering with understated thicknesses are the vital problems. It can be successful if accelerated safe investigation methods allowing the determination of the service life of coatings are developed and applied. A series of investigations were completed on the influence of the sea water aggressivity factors (temperature, humidity, SO2 Cl concentration) on the kinetics and mechanism of the coatings failure. We determined the regularities of the thickness decrease and the formation rate of failed parts of coatings in conditions of the operation. The results allowed us to work out the optimal regimes of tests for the zinc, cadmium and nickel coatings with coefficient of acceleration for 17 to 21. The mechanism of coating failure existing in conditions of vessel operation is preserved in these tests.

The authors describe a method for detecting and isolating changes in a flow measuring system using a wideband and unconditioned signal taken direct from the flow sensing element. The new concept is based on the hypothesis that the wideband band unconditioned signal taken directly from a sensor represents the response of a linear time-invariant system to both the deterministic and the random components of the excitation from the associated process. It is shown that the output from a process instrument can comprise two components; (i) the measurand and (ii) the condition signals. The emphasis is placed on an approach which can be used to derive the parameters of a condition signal. The logical expressions which describe whether or not the measurement, the condition of the instrument, or the operational status of the plant has changed, can be readily mapped into a digital format representing the condition signal. The concepts have been applied to a differential pressure measurement system.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Adaptive type-2 fuzzy-neural switching control for wastewater treatment process under several operating conditions

Pollution caused by ship emissions has drawn attention from various countries. Because of the high density of ships in ports, channels, and anchorages and their proximity to the densely populated areas, ship emissions will considerably impact these areas. Herein, a Chinese seagoing ship is selected and a platform is established for monitoring the ship emissions to obtain detailed characteristics of the ship’s nearshore emissions. The ship navigation and pollution emission data are obtained under six complete operating conditions, i.e., berthing, manoeuvring in port, acceleration in a channel, cruising, deceleration before anchoring, and anchoring. This study analyzes the concentrations of the main emission gases (O2, NOX, SO2, CO2, and CO) and the average emission factors (EFs) of the pollution gases (NOX, SO2, CO2, and CO) based on the engine power under different operating conditions. Results show that the change in O2 concentration reflects the load associated with the main engine of the ship. The NOX, SO2, and CO2 emission concentrations are the highest during cruising, whereas the peak CO emission concentration is observed during anchoring. The average EFs of NOX and SO2 based on the power of the main engine are the highest during cruising, and those of CO2 and CO are the highest after anchoring. The ship EFs are different during acceleration and deceleration. By comparing the EFs along the coast of China and the global EFs commonly used to perform the emission inventory calculations in China, the NOX EFs under different operating conditions is observed to be generally lower than the global EFs under the corresponding operating conditions. Furthermore, the SO2 EF is considerably affected by the sulfur content in the fuel oil and the operating conditions of the ship. The average CO2 EFs are higher than the global EFs commonly used during cruising, and the CO EFs are higher than the global EFs under all the conditions. Our results help to supplement the EFs for this type of ship under different operating conditions, resolve the lack of emission data under anchoring conditions, and provide data support to conduct nearshore environmental monitoring and assessment.

Two experiments investigated EC effects produced by pairing neutral stimuli (CSs) with instrumental responses that had acquired evaluative properties via operant conditioning. In Experiment 1, participants (N = 176) learned to associate pressing one key with a higher monetary reward and another key with a lower monetary reward. In a subsequent stimulus conditioning phase, the same responses were performed to categorise CSs without receiving monetary outcomes (instrumental extinction). Brands paired with the higher-value response were evaluated more positively than brands paired with the lower-value response. Experiment 2 followed a similar procedure but rewarded responses with token currencies of equal value during the operant conditioning phase. Additionally, participants (N = 368) were informed after stimulus conditioning that one currency had doubled in value while the other had lost all value. This postconditioning revaluation significantly shifted brand evaluations in favour of the response linked to the upvalued currency. The revaluation effect indicates that CS evaluations depended on the current value of the conditioned outcome, supporting an S:R-S account in which the US serves as a referent for CS evaluation. Findings highlight the role of action-outcome relationships in shaping preferences and attitudes.