Measurement of Exhaust Emissions under Actual Operating Conditions with the Use of PEMS: Review of Selected Vehicles

This paper is a synthetic approach to real driving (RDE) from selected vehicles: light-duty vehicle (LDV), heavy-duty vehicle (HDV). The tests were performed with the portable emission measurement system (PEMS) equipment under actual traffic conditions. The paper discusses problems of measurement methodology and emission of CO, HC, NOx, and PM. The performed investigation confirms that the main problem is the emission of NOx and PM, which usually is higher than the emission level. The obtained results show that the RDE method is very complex, but is the only way to provide invaluable information on the actual on-road exhaust emissions, not obtainable under laboratory conditions. In recent years, methods of exhaust emission testing under actual operating conditions have been developing rapidly. New technologies for extra low engine emissions pose a new question: does emission testing in a standard laboratory reflects real life emissions of a vehicle in use? In order to answer this question, it is necessary to measure the vehicle in-use emissions. Today, we know that the engine operating conditions (engine load and speed) in laboratory tests are not compliant with the conditions of actual operation. That is why the results of such tests are so desirable

UCHL1/PGP 9.5 Dynamic in neuro-immune-cutaneous milieu : focusing on axonal nerve terminals and epidermal keratinocytes in psoriatic itch

Psoriasis is an immunogenetic skin disease manifesting as plaque lesions on the skin. Patients with psoriasis frequently suffer from itch, an unpleasant sensation causing a desire to scratch. Psoriatic itch is mainly transmitted by unmyelinated C-fibers; however, the exact molecular mechanism of psoriatic itch is still unexplained. Protein gene product 9.5 (PGP 9.5) is a panneurological marker commonly used for analysis of peripheral peptidergic and nonpeptidergic nerves and identification of cutaneous neuro-immune-endocrine cells. However, some studies suggested that nonneuronal cells, like keratinocytes, may also express PGP 9.5. This phenomenon might be linked with impaired axonal transport, keratinocyte injury, or dysfunctions of neuro-immune-cutaneous connections. The aim of this study was to analyze the expression of PGP 9.5 in psoriatic skin. We observed significantly altered density of PGP 9.5-positive axonal nerve terminals in pruritic lesional (p=0.04) and nonlesional psoriatic skin (p>0.001) compared with controls. In contrast, no significant differences were observed between psoriatic skin without itch and controls. Furthermore, PGP 9.5 expression by suprabasal keratinocytes (SBKs) was significantly increased in itchy skin lesions (p=0.007) compared to skin without itch, and a positive correlation was observed between PGP 9.5 expression and itch intensity (r=0.64; p=0.02). Our findings indicate changes in peripheral innervations and psoriatic keratinocytes, which may influence neuro-immune-cutaneous homeostasis and modulate itch transmission

Numerical analysis of species diffusion and methanol decomposition in thermocatalytic reactor based on the Intermetallic phase of Ni3Al for low Reynolds numbers

Numerical modelling of hydrogen production by means of methanol decomposition in a thermocatalytic reactor using corrugated foil made of the Ni3Al intermetallic phase is shown in the paper. Experimental results of the flow analysis of mixtures containing helium and methanol in a thermocatalytic reactor with microchannels were used for the initial calibration of the CFD calculations (calculations based on the Computational Fluid Dynamics method). The reaction of the thermocatalytic methanol decomposition was modelled based on experimental data, considering the size of the active surface. The drop in the methanol concentration at the inlet to the reactor, ten millimetres in front of the thermocatalytic region, is associated with the diffusion of streams of other components, mainly hydrogen and carbon monoxide. The commercial CFD code was expanded by User Defined Functions (UDFs) to include surface chemical reaction rates in the interphase between the fluid and the solid. Extrapolation of data by means of the implemented numerical model enabled the assessment of the minimum length of microreactor channels and prediction of the optimal dimension at the system outlet. The results obtained by means of numerical calculations were calibrated and compared with the experimental data, confirming a satisfactory consistency of the data

Compact High Efficiency and Zero-Emission Gas-Fired Power Plant with Oxy-Combustion and Carbon Capture

Reduction of greenhouse gases emissions is a key challenge for the power generation industry, requiring the implementation of new designs and methods of electricity generation. This article presents a design solution for a novel thermodynamic cycle with two new devices—namely, a wet combustion chamber and a spray-ejector condenser. In the proposed cycle, high temperature occurs in the combustion chamber because of fuel combustion by pure oxygen. As a consequence of the chemical reaction and open water cooling, a mixture of H2O and CO2 is produced. The resulting working medium expands in one turbine that combines the advantages of gas turbines (high turbine inlet temperatures) and steam turbines (full expansion to vacuum). Moreover, the main purpose of the spray-ejector condenser is the simultaneous condensation of water vapour and compression of CO2 from condensing pressure to about 1 bar. The efficiency of the proposed cycle has been estimated at 37.78%. COM-GAS software has been used for computational flow mechanics simulations. The calculation considers the drop in efficiency due to air separation unit, carbon capture, and spray-ejector condenser processes. The advantage of the proposed cycle is its compactness that can be achieved by replacing the largest equipment in the steam unit. The authors make reference to a steam generator, a conventional steam condenser, and the steam-gas turbine. Instead of classical heat exchanger equipment, the authors propose non-standard devices, such as a wet combustion chamber and spray-ejector condenser

A study of jet impingement cooling enhancement by concave and convex heat sink shape modifications

The rising demand for efficient cooling technologies is a strong driver of extensive research in this area. This trend is particularly strong in turbines and microprocessors technology. Presented study is focused on the jet impingement cooling concept, which is used in various configurations for many years. The potential of the heat sink shape modification is not yet fully explored. Available literature suggests that average Nusselt number can be improved by more than 10% by adding conical shape in the stagnation region. This refers to the axisymmetric case where cold-water jet impinges the surface of heated aluminium. Presented results are based on 2D axisymmetric thermal-FSI (Fluid-Solid Interaction) model, which was validated against the experiment. The objective of the presented analysis is to determine the correlation between cooling effectiveness (Nusselt number) and chosen examples of concave and convex shapes located in the jet stagnation area

Moda, Wiara i Fantazja – przeciw budowie Elektrowni Ostrołęka C - "ostatniej elektrowni węglowej"

Żyjemy w epickich czasach, kiedy budowa najzwyklejszej elektrowni staje się kluczowym bastionem walki o kształt, tempo i kierunki rozwoju naszego kraju. Co jakiś czas w gospodarce państwa potrzeba jest nowego koła zamachowego budzącego nadzieję, otwierającego nowe perspektywy gospodarcze i społeczne. Właśnie takim kołem ma stać się stosunkowo mała inwestycja dwóch spółek giełdowych, jaką jest budowa nadkrytycznego bloku węglowego Ostrołęka C o mocy 1000 MWe

The influence of joined elements thickness on the strength of a plastic glue joint

W artykule przedstawiono wyniki autorskich badań wpływu grubości łączonych ze sobą blach na wytrzymałość złącza klejonego. Obiekt badań stanowiły łączone w sposób zakładkowy za pomocą kleju Plexus MA 300 płaskowniki wykonane ze stopu aluminium PA 9. Na podstawie przeprowadzonych badań stwierdzono, że grubość łączonych blach w badanym zakresie wpływa na wytrzymałość złącza, przy czym wytrzymałość rośnie wprost proporcjonalnie do grubości łączonych blach.The article presents the results of the author's research on the impact of thicknesses of joined sheets on the strength of the glued joint. In the experiment sheets welded together, made of aluminum PA 9, were welded together. Based on the tests of weld strength made of Plexus MA 300 adhesive, it was found that the thickness of the joined sheets in the tested range affects the strength of the joint, while the strength increases in direct proportion to the thickness of joined sheets