46 research outputs found
An impact assessment of functional systems in vehicles on CO
The number of facilities for a driver increasing the travel comfort in a PC vehicle is constantly increasing. Most of them are powered by electricity generated at a cost of additional engine load. Power is received directly from the crankshaft by an alternator or air conditioning compressor, which negatively affects fuel consumption. This paper presents the results of CO2 emission testing in actual traffic conditions for vehicles with on and off functional systems responsible for driving comfort. In addition, an assessment of fuel consumption calculated using the carbon balance method was performed. Measurements were made for cold start and preheated combustion unit the research used the latest PEMS mobile apparatus
Functional Data Privacy Algorithms for User Based Insurance
By monitoring each driverâs driving characteristics individually, car insurance premiums can be set to directly reflect that driverâs risk. Since such premiums tend to be cheaper, their uptake has increased in recent years, even outside the original market of young drivers. However, a lot of data (including GPS) is collected about each car journey in order to judge the driverâs ability which raises privacy issues, with a particular concern being that every car journey can be reconstructed from that data. We looked at what to change (or remove) from the collected data so that driverâs journeys couldnât be reconstructed, while retaining as much information about each driver as possible so the insurance company can still study a driverâs charcateristics and potentially use the bulk data for testing new methods in future. Control F1 does not want to use private key cryptography for customer relation reasons. We have deduced that GPS data would have to be deleted to retain privacy, however a quick experiment and a literature review suggests using heading and distance travelled data would still be sufficient to reconstruct journeys. We considered deleting GPS data and time data and then randomising all the data points of a journey. This removes most of the information about the journey but the âestimated journey vectorâ constructed from the bearing and distance data will still be retained. The journey vector most accurately matched the actual GPS calculated journey vector for longer journeys and non-circular journeys. Also, particularly for longer journeys, it can be used to identify similar journeys e.g. someoneâs commute. Cars slow down at junctions and traffic lights so data points are more commonly taken just before a turn. This effects the accuracy of the bearing and distance data. We studied the error in the âlocal estimated journey vectorâ caused by a junction. We suspect distance errors grow faster than bearing errors, which agrees with the analysed data
New teoretical cycle for active combustion chamber engine
This paper presents calculations of the theoretical cycle of engines with an active combustion
chamber depending on energy delivery and dissipation. In the case of ACC engines, a different
calculation approach is required to account for the possibility of additional volume change,
independent of the piston-crank system. The introduction presents a schematic diagram of volume
change, accomplished by two independent piston-crank systems and an active combustion
chamber, as proposed by the authors. Moreover, the diagram, which is the basis for analysis in this
paper, illustrates characteristic points of the cycle. In existing theoretical cycles of combustion, this
issue does not present any difficulties, since the solution is exact and based on known equations.
In the case of theoretical ACC engines, however, the situation is different, since this engine can
perform not only in typical cycles, but also in new ones. To explain the challenges of these new
cycles, authors present a few of the most probable calculation variants, taking into account the new
kinematic capabilities of ACC engines. Each comment justifying the choice of a certain calculation
variant is illustrated with a theoretical cycle figure and closest approximation of induced pressure
course of the ACC engine. At the same time, however, the authors show that this problem can have
many interpretations. It has been concluded that the solution depends on the assumptions made
about the active combustion chamber, namely its principle of operation
Transcriptional profiling validates involvement of extracellular matrix and proteinases genes in mouse gonad development
International audienceExtracellular matrix (ECM) plays an important scaffolding role in the establishment of organs structure during development. A great number of ECM components and enzymes (proteinases) regulating formation/degradation of ECM during organ remodeling have been identified. In order to study the role of ECM in the mouse gonad development, especially during sexual differentiation of the gonads when the structure of the testis and ovary becomes established, we performed a global analysis of transcriptome in three main cell types of developing gonad (supporting, interstitial/stromal and germ cells) using transgenic mice, cell sorting and microarray. The genes coding for ECM components were mostly expressed in two gonadal cell lines: supporting and interstitial/stromal cells. These two cell lines differed in the expression pattern of ECM components, which suggests that ECM components might be crucial for differentiation of gonad compartments (for example testis cords vs. interstitium in XY gonads). Collagens and proteoglycans coding genes were mainly expressed in the interstitium/stromal cells, while non-collagen glycoproteins and matricellular coding genes were expressed in both cell lines. We also analyzed the expression of genes encoding ECM enzymes that are secreted to the ECM where they remodel the scaffolding of developing organs. We found that the ECM enzyme genes were also mostly expressed in supporting and interstitial/stromal cells. In contrast to the somatic cells, the germ cells expressed only limited number of ECM components and enzymes. This suggests that the germ line cells do not participate, or play only a minor role, in the sculpting of the gonad structure via ECM synthesis and remodeling. Importantly, the supporting cells showed the sex-specific pattern of expression of ECM components. However, the pattern of expression of most ECM enzymes in the somatic and germ cells is independent on the sex of the gonad. Further studies are required to elucidate the exact roles of identified genes in sexual differentiation of the gonads. © 2017 Elsevier B.V
Exhaust Emissions Measurement of a Vehicle with Retrofitted LPG System
The aim of this study was to compare and evaluate the production of exhaust emissions from a vehicle with a petrol engine with the Euro 4 emission standard and powered by petrol and LPG (liquefied petroleum gas). The paper presents new possibilities for monitoring exhaust emissions using an exhaust gas analyzer. At the same time, it points out the topicality and significance of the issue in the monitored area. It examines the impact of a change in fuel on emissions. This change is monitored in various areas of vehicle operation. Measurements were performed during real operation, which means that the results are fully usable and applicable in practice. The driving simulation as well as the test conditions correspond to the RDE (Real Driving Emissions) test standard. A commercially available car was first selected to perform the tests, which was first measured in the original configuration (petrol drive). Based on real-time RDE driving tests, it is possible to determine the number of exhaust emissions. Subsequently, the same measurements were performed with the same vehicle, but the vehicleâs propulsion was changed to LPG. The vehicle was equipped with an additional system that allowed the vehicle to be powered by LPG. The results from the individual driving tests allowed the determination of the exhaust emissions. Emissions of CO (carbon monoxide), CO2 (carbon dioxide), HC (hydrocarbons), and NOx (nitrogen oxides) were monitored as a matter of priority. Through the driving tests, it was found that the gasoline combustion produced higher CO (1.926 g/km) and CO2 (217.693 g/km) emissions compared to the combustion of liquefied gas, where the concentration of the CO emissions was 1.892 g/km and that of the CO2 emissions was 213.966 g/km. In contrast, the HC (0.00397 g/km) and NOx (0.03107 g/km) emissions were lower when petrol was burned. During LPG combustion, the HC emissions reached 0.00430 g/km, and the NOx emissions reached 0.05134 g/km. At the end of the research, the authors compared the emissions determined by real driving (in g/km) with the emission values produced by the emission standard EURO 4 and the certificate of conformity (COC). Practical measurements showed that the vehicle produced excessive amounts of CO when burning gasoline. This production is 0.926 g/km higher and 0.892 g/km higher when burning LPG compared to the limit set by the Euro 4 Emission Standard. The difference is even greater than the limit value stated in the COC document. For other substances, the monitored values are in the norm and are even far below the permitted valu
High compression spark ignition engine with variable compression ratio using Active Combustion Chamber
Abstract In this article Authors present the continuation of the calculations for theoretical ACC engine cycle, considering additionally âVCR functionâ â changeable compression level. For this purpose the self-acting volume change, realized by ACC system, was used. The ACC system was adjusted appropriately to control the compression level. The analysis is based on three cases, representing delayed, premature and optimal reaction of ACC system. Reactions are presented in form of plots with indicated pressure in the combustion chamber. As the result of the conducted analysis and interpretation of obtained graphs, the calculation approach of compression ratio for ACC presented in previous article is being challenged. For the optimal reaction of ACC system, the theoretical operation schematics are devised and presented in the key points of the work. Based on the schematics, the values of theoretical efficiency were calculated for different cycles of theoretical ACC engine, in which regulation of compression ratio takes place. Moreover, the presented analysis includes graphs with optimal courses of indicated pressure for significantly different work parameters of ACC engine, showing its regulation possibilities. Also the time scaled graphs (with millisecond as basic time unit) are presented to show the possibilities of dynamic ACC systems, which are comparable with the combustion time (from 3 to 0,5 ms). In this paper the general discussion is started about the compression ratio in more complex kinematic systems including ACC
High compression spark ignition engine with Variable Compression Ratio using Active Combustion Chamber.
Abstract
In this article Authors present the continuation of the calculations for theoretical ACC engine cycle, considering additionally "VCR function" â changeable compression level. For this purpose the self-acting volume change, realized by ACC system, was used. The ACC system was adjusted appropriately to control the compression level. The analysis is based on three cases, representing delayed, premature and optimal reaction of ACC system. Reactions are presented in form of plots with indicated pressure in the combustion chamber.
As the result of the conducted analysis and interpretation of obtained graphs, the calculation approach of compression ratio for ACC presented in previous article is being challenged. For the optimal reaction of ACC system, the theoretical operation schematics are devised and presented in the key points of the work. Based on the schematics, the values of theoretical efficiency were calculated for different cycles of theoretical ACC engine, in which regulation of compression ratio takes place.
Moreover, the presented analysis includes graphs with optimal courses of indicated pressure for significantly different work parameters of ACC engine, showing its regulation possibilities. Also the time scaled graphs (with millisecond as basic time unit) are presented to show the possibilities of dynamic ACC systems, which are comparable with the combustion time (from 3 to 0,5 ms). In this paper the general discussion is started about the compression ratio in more complex kinematic systems including ACC
Oscillatory structural forces between charged interfaces in solutions of oppositely charged polyelectrolytes
Forces between negatively charged micron-sized silica particles were measured in aqueous solutions of cationic polyelectrolytes with the atomic force microscope (AFM). In these oppositely charged systems, damped oscillatory force profiles were systematically observed in systems at higher polyelectrolyte concentrations, typically around ew g/L. The wavelength of these oscillations is decreasing with increasing concentration. When the wavelength and concentration are normalized with the cross-over concentration, universal power-law dependence is found. Thereby, the corresponding scaling exponent changes from 1/3 in the dilute regime to 1/2 in the semi-dilute regime. This dependence is the same as in the like-charged systems, which were described in the literature earlier. This common behavior suggests that these oscillatory forces are related to the structuring of the polyelectrolyte solutions. The reason that the oppositely charged systems behave similarly to like-charged ones is that the former systems undergo a charge reversal due to the adsorption of the polyelectrolytes to the oppositely charged surface, whereby sufficiently homogeneous adsorbed layers are being formed. The main finding of the present study is that at higher polyelectrolyte concentrations such oscillatory forces are the rule, including the oppositely charged ones