A liquid chromatographic method for the quantitative analysis of S-(+)- and R-(-)-citalopram in human plasma has been developed and validated. The enantiomers of citalopram and the internal standard, R-(+)-propranolol, were extracted from alkaline plasma with 2% n-butanol in n-hexane. After a clean-up step, the organic phase was evaporated and the residues dissolved in 50-100 microliters of 0.001 M HCl. The separation was performed on a Chiral-AGP column with 3.0 mM N-dodecyl-N,N-dimethylammonio-3-propanesulfonate and 10 mM hexanoic acid in phosphate buffer pH 6.5 as the mobile phase. The limit of detection was estimated to be 1 ng/ml (S/N approximately equal to 3) for each enantiomer monitoring UV absorption at 240 nm. In the range studied, 2.31-191 ng/ml, the recoveries were quantitative and the coefficients of variations were between 2.47% and 11.5%.

Objective To determine medication possession ratio (MPR) of patients with asthma/COPD drugs. Method Individual patient's volumes of asthma/COPD drugs (ATC-code R03) for 2000-2004 were obtained from a pharmacy record database. For each patient the MPR was calculated as the percentage of the treatment time that the patient had drugs available. Main outcome measure Medication possession ratio (MPR). Results A total of 1,812 patients, 20 years and older, with dispensed asthma/COPD drugs were registered in the database, 928 patients (51%) had acquired drugs less than once per year (68% for 20-29 years old) during the 5-year study. Only 13% of the patients had steroids and steroid combinations available to allow continuous treatment. Eight percent of the patients 20-29 years old had MPR >/= 80% of all the included drugs and 5% when only steroids and steroid combinations were considered. About 25% of the patients had acquired 80% of the total volume of asthma/COPD drugs. Conclusion The majority of the patients, and particularly those in the youngest age group used asthma/COPD drugs only sporadically. This may indicate undermedication which is likely to have a negative impact on patient outcome.

Background: Many patients with asthma underuse steroids for inhalation. This has been identified as a main cause of therapy failure and of excess health care utilization.Objective: To elucidate the medication persistence of patients using asthma drugs, how patients combine the drugs over time and whether medication persistence was influenced by patients switching to combination products.Methods: Individual patients' drug acquisition data were obtained from a pharmacy record database for the period 2000-2004. A patient was considered to have satisfactory medication possession ratio (MPR) if the medication supplies covered ≥80% of the prescribed treatment. Drug use profiles were constructed as graphs for each patient, showing the date of each refill and the time period covered by the dispensed drugs. From the graphs the combination of drugs, the continuity of the therapy over time and the MPR for each patient could be determined.Results: Of 1812 patients with asthma drugs in the database, 815 fulfilled the inclusion criteria. The percentage of patients with satisfactory MPR was low (11-27%), but significantly higher among patients using combination products than among those using steroids. For patients who switched from adrenergics plus steroids in two inhalers to combination products in one inhaler, the number of patients with satisfactory MPR was significantly increased.Conclusion: Satisfactory MPR was low for all types of asthma drugs. More patients had satisfactory MPR with combination products in one inhaler than with adrenergics and steroids in two separate inhalers. Asthma drug-delivery is important and combination products of the two ingredients could therefore improve asthma therapy.

Arbetsmaskiner förbrukar en mycket stor del av det dieselbränsle som används i landet. En stor del av avgasemissionerna härrör följaktligen från dessa maskiner. Det är därför viktigt att ta fram kunskap om vilka emissioner som avges och på vilka olika sätt emissionerna kan minskas. Som ett led i detta arbete har projektet "Utveckling av relevanta arbetscykler och emissionsfaktorer samt reducering av bränsleförbrukningen för arbetsmaskiner" (EMMA) genomförts. Projektet har finansierats av Kommunikationsforskningsberedningen (numera en del av VINNOVA), Energimyndigheten, Vägverket och LRF. Dessutom har Volvo Wheel Loaders ställt motorer och Valtra Traktor AB traktorer och motorer tillprojektets förfogande. Vidare har JTI disponerat en större traktor från Lantmännens Maskin Import AB.Projektet har genomförts av ett konsortium bestående av:Luleå tekniska universitet (LTU)JTI - Institutet för jordbruks- och miljöteknik (JTI)Institutionen för lantbruksteknik SLU (LT)SkogForsk (Skog)Svensk Maskinprovning AB (SMP)Vägverket Produktion (VägvP)I denna rapport sammanfattar Luleå Tekniska Universitet sina resultat från emissionsmätningarna i EMMA projektet. Mätningarna omfattar fyra arbetsmaskiner som har körts i motorprovbänk enligt en 22- punkters testcykel. Motorerna som testades var en Sisu Diesel 620 DWRE, en Volvo TD63 KDE, en Volvo TD40 GJE samt en Sisu diesel 420 DWRE. Motorerna testades vid Luleå Tekniska Universitets motorlaboratorium samt vid Svensk maskinprovning i Umeå. Både reglerade och icke-reglerade emissioner har uppmätts. De reglerade emissionerna som har mätts är HC, NOX och CO. De icke reglerade komponenterna som analyserats är formaldehyd, acetaldehyd, akrolein, bensaldehyd, etan, eten, propan, propen, propyn, isobutan, acetylen, 1-buten, isobuten, pentan, 1,3-butadien, bensen, toluen, M-xylen och O-xylen.Genom att använda uppmätta tidsprocentvärden från ett antal olika arbetsoperationer, som därefter har fördelats enligt moderna i ISO 8178, har emissionsfaktorer för ett antal olika arbetsoperationer genererats.

A nine liters ethanol-fueled CI engine was equipped with aftertreatment devices while different ratios of exhaust gas recirculation (EGR) were tested. The NO\dX emissions were negatively correlated to the EGR-ratio and NO\dX reductions of between 33% and 73% were obtained. Unfortunately, the decrease in NO\dX was followed by increased emissions of carbon monoxide, hydrocarbons, particulate matter and higher fuel consumption. The particle number emission increased approximately 4 times and particle sizes above 200 nm became more frequent when using EGR. The remedy for these emissions was to combine an oxidation catalyst and a diesel particle filter (DPF), while keeping the EGR-ratio low to minimize fuel consumption. Equipped like this, the engine passed the Euro 5 regulation as well as the Enhanced Environmentally Friendly Vehicles standard (EEV).

A commercially available exhaust aftertreatment system, DNO\dx\sT, comprising exhaust gas recirculation (EGR), an oxidative catalyst and a continuously regenerating diesel particulate filter (DPF) were tested. The test object was a 9-liter, ethanol-fueled diesel engine from Scania equipped with turbocharger and aftercooler. A similar diesel engine from Scania, but running on ordinary Swedish diesel fuel, was used as a reference and a reminder of "the state of the art." The tests involved two different ethanol fuels containing various ignition improvers, Beraid 3540 and rapeseed methyl ester. Test conditions for the engines were those specified in the European Stationary Cycle (ESC). The aftertreatment system reduced the emissions of HC, CO and NO\dx, down to 0.15, 0.04 and 2.54 g/kWh, respectively, while the estimated particle mass was reduced by 67%. Actually, by using the DNO\dx\sT system, the engines became Euro IV engines regarding the emissions of HC, CO and NO\dx. The ethanol-fueled engine without EGR, catalyst or DPF emitted approximately 1.6 times more formaldehyde and 9.8 times more acetaldehyde than the diesel engine. However, the emission of acrolein was only 0.47 times the emission of acrolein from the diesel engine. When the ethanol-fueled engine was equipped with DNO\dx\sT, a significant reduction of the emissions of aldehydes was obtained. The emissions of acrolein, formaldehyde and acetaldehyde were reduced by 56%, 87% and 95%, respectively. An even higher reduction was observed when the system was connected to the diesel engine. Fifteen different hydrocarbons (alkanes, olefins and monoaromates) were also identified. The diesel-fueled engine, without any exhaust aftertreatment devices, emitted approximately twice as much hydrocarbon than the ethanol-fueled engine, also without any exhaust aftertreatment devices. However, there were also qualitative differences. Three hydrocarbons, namely propene, ethene and benzene, accounted for 77% of the hydrocarbons emitted from the diesel-fueled engine, while acetylene, ethene and benzene, made up only 53% of the hydrocarbons emitted from the ethanol-fueled engine. When connecting the system to the engines, a difference was observed; the reduction of analyzed hydrocarbon emissions was approximately 90% for the diesel-fueled engine, but only 47% for the ethanol-fueled engine. The studied aftertreatment system has been developed and optimized for the diesel-fueled engine. This fact is reflected in the powerful reduction of hydrocarbons, aldehydes, particles and NO\dx that is obtained when connecting the system to the diesel-fueled engine. Nevertheless, a significant reduction is also obtained when connecting the system to the ethanol-fueled engine. Test results indicate that it should be possible to better optimize the system for the ethanol engine. It is also, probably, necessary to exchange the catalyst in the system. Thereby, an even higher reduction of unregulated and regulated emissions should be obtained

Experiments were performed to investigate the potential to achieve low emissions from a diesel engine fueled by ethanol and equipped with a commercially available exhaust after-treatment device, DNO\dx\sT from STT Emtec. The DNO\dx\sT system includes exhaust gas recirculation (EGR) catalysts and a continuously regenerating diesel particulate filter (DPF). Two Euro III classified 9-liter turbocharged, after-cooled diesel engines from Scania were used for the task. One engine was fueled by ethanol and the other by Swedish diesel fuel, EC1. Engine operating conditions of a 22-mode test cycle, including the 13 modes of the European Stationary Cycle (ESC cycle), were used for the tests. The emissions of NO\dx and HC were small for the ethanol-fueled engine, 3.48 and 0.53 g/kWh, respectively, while the emission of CO was higher, 2.07 g/kWh. Estimations of emitted particle mass were calculated by using the software supplied in the Scanning Mobility Particle Sizer (SMPS). The estimations showed that the ethanol engine emitted only \mA1/10 of the particle mass emitted by the diesel-fueled engine. A powerful reduction of the regulated emissions was obtained when equipping the ethanol engine with EGR, catalyst and DPF. The emissions of HC, CO and NO\dx decreased down to 0.15, 0.04 and 2.54 g/kWh, respectively, while the estimated particle mass was reduced by 67%. Actually, by using the aftertreatment system, the engine became a Euro IV engine regarding the emissions of HC, CO and NO\dx. The system worked even better with the diesel-fueled engine. The NO\dx emission was reduced by approximately 33% and the estimated particle mass by more than 99%. Calculations showed that the EGR ratio was higher for the diesel engine than for the ethanol engine. Consequently, by applying a higher EGR ratio for the ethanol engine an additional reduction of the NO\dx emissions should be obtained. The results indicate that very low NO\dx and particle emissions could be obtained for an ethanol-fueled diesel engine by using the right aftertreatment equipment. Future studies should investigate the possibility to increase the EGR ratio further. The investigations also underline the need for development of a special particulate filter for ethanol engines.

A column-switching system for fast determination of (R)- and (S)-naproxen in liver microsomes has been developed. The centrifuged sample was injected directly onto a pre-column with octadecylcoated silica. The retained analytes were then directed to an alpha 1-AGP column using a mobile phase composed of phosphate buffer (pH 6.5), dimethylocytylamine (30 mM) and the nonionic surfactant, Tween 20 (40 g/l). The method gave high absolute recoveries and good repeatabilities: 99.6% (1.7% relative standard deviation) and 94.9% (2.4% R.S.D.) for the (R)- and (S)-naproxen, respectively. The use of a surfactant in combination with an aliphatic amine in the mobile phase involves reduced retention times with retained enantioselectivity. Furthermore, the presence of the surfactant makes it possible to inject biological samples directly into the chromatographic system.

The retentions and enantiomeric resolutions of remoxipride, propranolol, and trimipramine were studied using a CHIRAL-AGP column with micellar mobile phases and aliphatic, anionic additives. The retentions of the compounds, which in neat buffer solution were very high (k > 50), could be decreased to k < 10 by adding a mixture of Tween® 20 and heptanoic acid to the mobile phase. The presence of the aliphatic acid was essential in order to increase the enantiomeric selectivity. An efficiency enhancement was obtained by increasing the temperature. With a mobile phase composition optimized for the separation of remoxipride, the possibility of detecting levels of the enantiomeric impurity (R-remoxipride) down to 0.025% in the drug was demonstrated.

A three-factor central composite face design (CCF) has been used for the optimization of the chiral resolution of the enantiomers of alprenolol, oxprenolol, trimipramine and propranolol on CHIRAL-AGP. The variables (factors) investigated were pH and concentrations of the micellar agent Tween((R)) 20 and heptanoic acid. The responses evaluated were resolution (R(S)), capacity factor (k') of the last eluted enantiomer and a chromatographic response function (CRF) defined as CRF = P-5/log t(ret), where P is the peak-valley ratio according to Kaiser and t(ret), is the retention time. The computed models, one for each substance and one for each response (in total 12 models), showed that the main factor for the regulation of R(S) as well as k' and CRF in the experimental domain is the pH. The optimal pH for the substances could be found between pH 5.5 and 6.5. The optimum was evaluated by generating contour plots for the CRF models. The computed mathematical models were statistically evaluated and the predictive power of the models was tested by ex perimentation

A retention model for the chiral separation of an uncharged solute, felodipine, on CHIRAL-AGP, using a micellar mobile phase is proposed. The model assumes the presence of two stereoselective sites and each enantiomer was found to interact with different sites. Addition of a chiral aliphatic alcohol, (+)-(S)-2-octanol, preferentially interacted with the binding site for (-)-(S)-felodipine. The monomeric form of the micellar agent (Tween® 20) competed with the enantiomers for the adsorption sites, and the formation of a 1:1 complex between the enantiomers and the micelles was assumed. The retention of the solutes was effectively controlled by adding small quantities (

Only 49% of the patients with T2D in Sweden that medicate with oral antihyperglycaemic drugs (AHGD) had good blood glucose control (HbA1C < 6.0%). The reason can be low medication adherence. The aim of this study was, therefore, to determine the adherence to different oral AHGD. Included were all patients in Sweden, older than 40 years and having at least two expenditures of AHGD between 1 December 2005 and 30 November 2006. After exclusions of inpatients and patients with unspecified daily dosage 171,220 patients (57% men) remained. Medication possession ratio (MPR) was used for estimating adherence and patients were regarded adherent if MPR ≥80%. The overall refill adherence average 90%, with mean MPR (SD) = 107% (30). Eighty-five percent of the patients in their 40s were adherent compared to 91% of the patients in their 80s. About 90.1% of the women were adherent whereas 89.5% of the men were adherent. Patients with an indication for the medicine were more adherent than patients without this information. We conclude that the unsatisfactory blood glucose control showed among many Swedish T2D patients is not the result of non-adherence to prescribed medication.

To explore the possibility of using dispensed volumes asthma/COPD drugs as a proxy for the combined prevalence of asthma plus COPD. METHODS: The proportions of the Swedish population with inhalation drugs for asthma/COPD 2004 were obtained using three different databases. A pharmacy record database gave the volumes of dispensed drugs (defined daily doses, DDDs of R03A + R03B drugs) for each patient, 20 years and older. The X-plain database of Apoteket AB gave drug sales data for Sweden and Swedish population data were obtained from Swedish statistics. RESULTS: The sales volumes of asthma/COPD drugs were much higher for older than for younger people. The volumes increased from 18 DDD/TID for the 20-29 year group up to 124 DDD/TID for patients 70-79 years, or about seven times. The average volumes per patient in the different age groups corresponded to one DDD/day in only three of the age groups (50-79 years). In the youngest group the average drug volume per patient corresponded to one DDD every second day, which may indicate undermedication. The percentages of the Swedish population with asthma/COPD drugs increased from 4.0% for 20-29 years old to 14.5% for 80+ years old, or 3.6 times. When head-to-head comparisons could be made between reported prevalence data of asthma and COPD and our data the two sets of data were in a reasonable agreement. CONCLUSION: The prevalence of drug treatment, i.e. the proportion of the population with dispensed asthma/COPD drugs, could function as a proxy for the disease prevalence of asthma plus COPD.

The aim of this review is to discuss the methodological issues involved in using pharmacy-record databases of drug sales in pharmacoepidemiology and to illustrate the usefulness of such data in estimating disease prevalence, patient adherence and persistence to therapy. Recent studies show that asthma/chronic obstructive pulmonary disease (COPD) prevalence increases with age. The volume of acquired asthma/COPD drugs per patient also increases with age and was approximately 2.5-times higher for patients aged 60-69 years compared with patients aged 20-29 years. Despite this, there is a comparatively low interest in asthma/COPD research involving elderly individuals. Published asthma/COPD-prevalence data and drug-treatment-prevalence data correspond reasonably well. Short- as well as long-term studies on drug acquisition indicate that approximately a third of patients have drugs available to cover at least 80% of the prescribed treatment time. Only approximately a tenth of the patients acquired steroids or steroid combinations, corresponding to one daily defined dose per day over a 5-year treatment period. It is probable that asthma/COPD is undertreated in all age groups.

Particulate and high emissions of NOx are the main problems that are associated with diesel engines. Therefore, techniques and fuels that promote a reduction in these emissions currently are attracting great interest In this paper, a mixture of acetal and regular diesel fuel has been tested in a heavy-duty diesel engine. The effect was a marked decrease in particle number and the estimated particle mass. A small reduction of the engine power was also observed; however, the net effect was nevertheless a reduction in the emission of CO₂ per European stationary cycle. The emissions of HC, CO, NOx ,some aldehydes, and hydrocarbons were only slightly affected by the new fuel composition. An exception was the emission of acetaldehyde, which was almost quadrupled, probably reflecting the decomposition and oxidation of acetal to acetaldehyde.

Reports have stated that Fischer Tropsch (FT) fuels are high quality, low emission diesel fuel substitutes. The purpose of this study is to compare the emissions from a heavy-duty, Valmet, diesel engine running on a commercial available FT fuel, Eco-Par\sT, with the emissions obtained when the same engine is running on a low-sulfur diesel fuel with low aromatic content, Swedish environmental class 1 (EC-1) diesel fuel. The two fuels have been analyzed by Fourier transform infrared spectroscopy and Raman Fourier transform infrared spectroscopy. The analyses showed that main constituents in the two fuels are alkanes with no substituents. No aromates or olefines could be detected. A small difference, later verified by gas chromatographic analyses, was noted; the Swedish EC-1 fuel consisted of a larger portion of straight chain, heavier hydrocarbons while the FT fuel consisted of more branched hydrocarbons. The overall impression of the emission analyses is that Eco- Par\sT gives lower emission than the EC-1 fuel during the modes employed in the ISO 8178 test. Emissions of acetaldehyde, benzaldehyde and acrolein were generally decreased 3-6 times when using FT fuel instead of EC-1 fuel while the emission of formaldehyde was unaffected. Fifteen volatile organic hydrocarbons were also included in the investigation - ethane, ethene, acetylene, propane, propene, propyne, propadiene, isobutene, isobutene, 1-butene, 1,3- butadiene, benzene, toluene, O-xylene and M-xylene. The emissions of the fifteen mentioned hydrocarbons were reduced between 20% - 93% when using Eco-Par\sT instead of EC-1. Measurements of the regulated emissions during an ISO 8178 test confirmed the obtained results; the emissions of total hydrocarbon (HC) decreased approx. 14% while the emissions of carbon monoxide, CO, and nitrogen oxides, NO\dx were almost unaffected. The test results in this investigation may indicate that diesel engines running on Eco-Par\sT can have a lower impact on environment and health than the, in Sweden, commonly used EC-1 fuel.

There is an ongoing search for better and cheaper ignition improvers to facilitate the introduction of ethanol fuel. Rapeseed methyl ester (RME) was therefore investigated in an ethanol fueled compression-ignited engine by means of different statistical designs. Experiments were accordingly performed at various levels of speed, load and concentration of RME in ethanol while the emissions were measured. The optimization criterions were; satisfactory engine performance and low exhaust emissions. Initial experiments showed that the power outlet and the opacity increased when using the tested ignition improver. A three level full factorial design correctly predicted that the emissions of HC, CO and NOX, should increase when using RME as an ignition improver. Lowest level of exhaust emissions was obtained at 16 % RME in ethanol but a higher concentration should be used to obtain better engine performance. A general conclusion is that RME seems suitable for the investigated task, i.e. ignition improvement, but the opacity increment should be further studied. Careful selection of the conditions used as well as rigorous control of the engine and dynamometer is necessary to obtain good repeatability and accuracy of the experimental conditions.

Ethanol-fueled engines are considered to be low particulate-emitting engines. This study was performed to investigate the potential to achieve even lower particulate emission if a 9-liter Scania diesel engine, running on ethanol fuel is equipped with emission control. State-of-the-art technology in emission control was applied, e.g., exhaust gas recirculation, EGR, catalysts and a continuous regenerating particle filter, DPF. Particulate emissions were compared with emissions from a 9-liter Scania diesel engine from the same engine family, running on Swedish environmental class 1 diesel fuel. Tailpipe measurements of particle size and distribution were performed with a scanning mobility particle sizer, SMPS, instrument together with filter sampling. An evaluation of SMPS measurements was performed for test conditions specified according to a 22-mode test cycle, which included the test modes in the European Stationary Cycle, ESC. Calculated weighted particle mass from SMPS data, and in accordance with ESC, showed that the ethanol engine without emission control emitted approx. 1/12 of particle mass compared to the diesel engine. Weighted particulate emissions were reduced by approx. 96%, when the engine was fitted with EGR and DPF. The reduction of weighted particulate emissions was even higher when the diesel engine was fitted with EGR and DPF, as high as 99%. Particle size and distribution measurements revealed that particles emitted from the ethanol engine mainly consisted of ultrafine particles (\ml100 nm), usually had a mean diameter of about 30 nm, while particles emitted from the diesel engine usually had mean diameters of about 60-70 nm and sizes going up to approx. 300 nm. Filter samples analyzed by Scanning electron microscopy and energy dispersive x-ray analysis SEM/EDX showed that the particles, both from the ethanol-fueled engine and the diesel-fueled engine mainly consisted of carbon and that they agglomerated, dependent upon running conditions, chainlike or clot-wise. Raman spectroscopy confirmed that the same elemental carbon was present in particles emitted from diesel and ethanol-fueled engines. The investigations showed that the system used, with EGR and DPF combined, is highly effective in reducing particulate emissions from ethanol- and diesel-fueled diesel engines. A general conclusion is also that the ethanol-fueled engine, equipped with emission control system or not, emitted lower particle mass, smaller particle sizes and approx. the same or a greater number of particles in the emissions than the diesel-fueled engine.

A humid air motor system (HAM) for NO\dx reduction has been connected to an eleven liters diesel engine. Earlier studies have demonstrated that the system has capacity to lower NO\dx emissions from diesel engines. The present study is directed to investigate the influence of the system on the emissions of particles and aldehydes, to monitor essential engine parameters, water consumption, and to verify the NO\dx reducing ability. The system has been tested under the various speed and load conditions stated in the 13-mode ECE R- 49 test procedure. Additional tests have been carried out for sampling and measurements of particles. The results showed that the particle number concentration usually increased when HAM was coupled to the engine. The increase in particle number concentration, observed in five out of six running modes, varied between 46% and 148%. There was no observed trend indicating a shift in mean particle diameter when using HAM. Engine performance was almost unaffected, while the HAM system caused a large reduction of the NO\dx emissions. Even without optimization of the experimental conditions the average reduction of NO\dx during the different modes of ECE R-49 was over 51%. The reduction was directly related to the humidity of the inlet air and a further reduction can be anticipated with higher humidity. The influence of the system on the emissions of hydrocarbons (HC) was negligible while a moderate increase in the emission of carbon monoxide (CO) was noticed. No confident relationship between air humidity and the observed effects (i.e., on HC and CO) could be detected. Samples were also taken for acetaldehyde and formaldehyde. The results are indicating a reduction of aldehydes in the range 78% to 100%, when using HAM. Unfortunately these large reductions may be false, since it cannot be excluded that they are a result of a combination of high air humidity and the sampling technique used.

This report presents results from a project with the aim of investigating the potential environmental and health impact of emissions from ethanol, ethanol blended diesel fuels and to compare these with neat diesel fuels. The exhaust emissions were characterized regarding regulated exhaust components, particulate and semivolatile Polycyclic Aromatic Compounds (PAC) and with bioassays. The bioassays were mutagenicity and TCDD receptor affinity tests. Results: Neat ethanol fuels are 'low emission' fuels, while European diesel fuel quality (EDF) and an ethanol blended EDF are 'high emission' fuels. Other fuels, such as Swedish Environmental Class one (MK1) and an ethanol blended MK1, are 'intermediate' fuels regarding emissions. When using an oxidizing catalyst exhaust after- treatment device a reduction of harmful substances in the exhaust emissions with respect to determined exhaust parameters was found. The relatively low emission of PAH from ethanol fueled engines would indicate a lower cancer risk from ethanol than from diesel fuels due to this class of compounds. However, the data presented emphasize the importance of considering the PAH profile.

Due to stringent regulations, tremendous efforts have been made worldwide in monitoring and diagnosing combustion engines. However, there is still a large need to further develop optimization models that facilitate the understanding of the relationship between engine parameters and parameters such as noise and exhaust emissions. The aim of present study was to investigate the potential use of vibration based diagnostics for prediction of different parameters such as noise, exhaust emissions, Pmax and the dp/d alpha . The method is based on a reconstruction of the cylinder pressure from vibration measurements on the engine surface. A three factorial central composite face design was used for the tests involving different running conditions (i.e. speeds and loads) and different blends of rap seed oil methyl esther (RME)/ethanol. Principal component analysis (PCA) and partial least squares (PLS) were thereafter used for establishing models that show the relationship between speed, load, amount of RME and responses such as cylinder pressure, exhaust emissions and sound pressure. The results show that the reconstructed cylinder pressure can be used for diagnostics and control by allowing an accurate estimation of Pmax and dp/d alpha . Furthermore, the method used is also applicable for determining apparent net heat release rate and hence the exact time of the start of the combustion process. A comparison between measured and predicted values of NOx, noise, Pmax and dp/d alpha showed a good predictive power of the established models.

There is a steadily growing demand for reliable, non-invasive measurement methods which can be used to monitor combustion in diesel engines. An effective, non-invasive method would make it possible for those using diesel engines to economically detect malfunctions during combustion. The main objective of this paper is to show how, through reconstruction, it is possible to generate data on combustion parameters, which can then be used for engine diagnostics. The combustion parameters are the maximum cylinder pressure (pmax, ) and the derivative of the pressure rise (dp/da). The idea is based on reconstruction by using the transfer function, TF, from the combustion chamber to the engine surface and the measured vibration response signal of the engine surface. The analysis is based on a non-linear method called complex cepstrum and signal processing techniques. The TFs were modified to fit slightly different situations such as other cylinders of the same engine; where use can be made of symmetry. A new approach based on a new tailor-made window for reconstruction of the cylinder pressure is also presented. A matrix with engine TFs for varying speed and load was obtained. The matrix can be used as a data bank of TFs for reconstruction of the cylinder pressure at different operating conditions. An extensive analysis of the cycle-to-cycle variations was carried out, both for the measured and reconstructed cylinder pressure. The main parameters of the cylinder pressure; the maximum cylinder pressure (pmax, ) and the derivative of the pressure rise (dp/da), are thoroughly examined in order to validate the procedure.

A new approach for reconstructing diesel engine cylinder pressure is presented. The technique is based on vibration measurements on the engine surface with subsequent reconstruction of the cylinder pressure by direct use of multivariate data analysis (MVDA). In order to investigate and evaluate the usefulness of the proposed technique, data from earlier experiments with four in-line, six cylinder, heavy-duty diesel engines have been used. One of the engines, running on ethanol, was tested according to a three factorial central composite face at different speeds and loads, as well as different blends of ethanol/ignition improver. The other engines, running on ordinary diesel, were tested with various loads and speeds. All of the measurements, i.e. cylinder pressure, sound pressure levels, vibration, and exhaust emissions, were performed simultaneously. The results demonstrated that MVDA models could accurately reconstruct cylinder pressures for all six cylinders in a diesel/ethanol engine. The differences between predicted and observed maximum cylinder pressure for 800 rpm were just 0-5%. The investigations also showed the potential of the method to estimate noise emissions and emission of NO x from the ethanol engine; a single partial least square (PLS) model could be used to predict noise and exhaust emissions at three different loads