Development of a Reference Dataset to Evaluate PEMS Post-Processing Software

Since the implementation of in-use emissions standards, an outcome of the consent decree between heavy-duty diesel engine manufacturers and the Environmental Protection Agency (EPA), there has been an increased interest in the research and development of portable emissions measurement systems (PEMS) that are capable of analyzing exhaust emissions continuously while a vehicle or equipment powered by an internal combustion engine is performing its intended vocation. Ultimately for an engine to pass in-use emissions requirements, the brake specific emissions of regulated pollutants measured over valid Not-to-Exceed (NTE) events must be less than or equal to 1.25 or 1.5 times the engine emission certification standards, based on the engine model year (MY), plus an additional margin known as in-use measurement allowance. The vehicle has to satisfy the in-use emissions standard for 90% of the NTE events provided the brake specific emissions over the rest of the events are less than two times the certification level to comply with in-use emission regulations.;As in-use emissions measurement and regulation together form a requirement since 2004 for certification of engines, it is imperative to develop procedures of oversight similar to ones that exist for laboratory-based engine certification. Therefore, a reference data set that incorporates all the in-use emissions regulations used to quantify the measured emissions over an NTE event, including the conditions used to validate an NTE event is developed in the direction of providing a means to validate commercial PEMS data analysis software.;A reference data set was designed and used to evaluate the post-processing software of two commercial PEMS devices. A black box testing methodology was implemented to evaluate the performance of the post-processing software. Specifically, the input data set was developed to execute different sections of the program based on logical conditions required to branch into a particular section therefore verifying the truth in executing a logical condition and the interpretation of in-use emissions regulation. Also, the brake specific emissions results to be expected from the given input data set were known a priori to verify the accuracy of the equations used in calculating the final emissions results. The dataset was also used to evaluate PEMS data post-processing software developed at WVU.;The test results indicated that definition of NTE emissions performance was not in agreement for the post-processing software evaluated. Being that compliance is required for manufacturers to sell engines without penalty, it is critical that the metric by which compliance is assessed must be accurate and robust. As such, the reference data set developed will serve in identifying interpretation errors of in-use emissions regulations as well as calculation error and reduce the chances of triggering false positives and negatives that could prove costly to engine manufacturers as well as air quality regulating agencies. This reference data set will also serve in effective implementation of any modification of existing or additional new in-use emissions compliance requirements and verify it across different in-use emissions data post-processing software supplied by PEMS manufacturers and developed in-house. Test results showed that PEMS post-processors outcome were not in agreement with expected total number of 166 NTE events as the in-house, PEMS A and PEMS B returned 216, 288 and 190 NTE events respectively. The reference dataset was instrumental in identifying interpretation error in the in-house data post-processor leading to a revised version of the software that matched the expected results

User-friendly interface design and development for continuous-casting model CON1D

An user interface to input parameters, run simulations, and graph the outputs from the continuous casting model CON1D was designed and implemented in a spreadsheet environment, with a focus on including features to expand the usability and audience of the model. CON1D is a very powerful and efficient 1-D transient computational model of heat transfer in the process of continuous casting of steel slabs. This model has been validated by many plant measurements to predict mold temperatures, shell thickness, mold heat flux, slab temperatures, and many other parameters. This interface incorporates worksheets where the user can enter input data with user-friendly features and functionality. A grade-table sheet allows the user to setup the composition of commonly used steel grades, which can be used to automatically fill fields when running various simulations. A spray table sheet allows a change in casting speed to automatically update water flow rates of all of the spray zones. The user interface includes the key ability to convert the units of parameters, allowing users to utilize either British units, metric units, or a customized mixture. The interface integrates with a familiar spread-sheet post-processor, which reads in the many output files generated by CON1D and plots the results in readily-customized graphs. User feedback was used to make iterative improvements to the system. The interface has received positive feedback from users. The added user-friendly features of the interface will allow a wider audience of users to benefit from the CON1D model, including both researchers and a larger group of users in the industrial environment of continuous casting systems

Reduction of Toxic Air Contaminants (TACs) and particulate matter emissions from heavy-duty natural gas engines

Increasing urban pollution levels have driven the Federal and the local air control boards to impose stricter emissions regulations on heavy-duty engines earmarked for transit buses. This has made natural gas a promising fuel for reducing the emissions of oxides of nitrogen and predominantly particulate matter from heavy-duty transit buses. Recent research studies performed at WVU and elsewhere have showed that natural gas engines emit an order of magnitude lower PM emissions, on a mass basis, when compared to diesel engines without any exhaust aftertreatment devices. However, on a number basis the emissions from natural gas fueled buses were an order of magnitude higher than their diesel counterparts.;This project was initiated by Southern California Air Quality Management District to design and develop an exhaust aftertreatment device for retrofitting urban transit buses powered by heavy-duty natural gas engines. The exhaust aftertreatment device was developed for a Cummins Westport C8.3G+ natural gas engine. Exhaust samples were collected by operating the vehicle on the Central Business District cycle on a chassis dynamometer. Regulated emissions were continuously measured while non-regulated emissions samples were collected on different media from a full flow dilution tunnel. In addition, PM concentrations and size distributions were also measured. (Abstract shortened by UMI.)

Knowledge and perception towards pharmacovigilance and adverse drug reactions reporting among medical students at a teaching hospital in South India

Background: Pharmacovigilance and adverse drug reactions monitoring has become an integral part to ensure patient safety. Targeting the younger doctors for sensitization towards pharmacovigilance is the key to ensure practice of ADR reporting in clinical practice. The objective of the study is to understand and assess the knowledge and perception of students towards pharmacovigilance and adverse drug reactions reporting.Methods: The study included undergraduate medical students of second, pre-final and final years of Mysore Medical College. A validated and standardized KAP based questionnaire was distributed to all students. Willingness to answer and complete the questionnaire was considered as consent.Results: The questions were statistically analysed individually and compared. Q1-Q10 compared knowledge towards pharmacovigilance, Q11-Q20 on the attitude and Q21-Q23 on the practice of ADR reporting. 325 questionnaires were distributed of which only 280 consented (second year - 114, pre-final - 98, final - 68). 112(49.1%), 137(69.9%) and 79(58.1%) of the three groups respectively knew what pharmacovigilance and ADR is. 79.8%, 76.5% and 75% knew who can report ADRs while 18.4%, 32.7% and 33.8% did not know what ADRs to report. 73(64.1%); 93(81.6%), 18(18.4%); 69(70.4%), 13(19.1%); 37(54.4%) knew the existence of AMC in the institute and the PvPI respectively. More than 92% agreed that ADR reporting is necessary. Majority (>90%) agreed that PV and ADR reporting should be taught to all health care students while 28%, 30% and 54% said that it was not well covered in their curriculum.73(64%), 51(52%) and 63(93%) were not familiar with the ADR reporting form.Conclusions: Pharmacovigilance and ADR reporting needs to be made compulsory, have better, interesting ways to learn and understand it, so that the students can practice it with confidence in their clinical practice

Simple and rapid high-performance liquid chromatography method for the determination of ofloxacin concentrations in plasma and urine

A high-performance liquid chromatographic method for the determination of ofloxacin in human plasma and urine was developed. The method involved deproteinisation of the sample with perchloric acid and analysis of the supernatant using a reversed-phase C column and fluorescence detection at an excitation wavelength of 290 nm and an emission wavelength of 18 460 nm. The assay was linear from 0.5 to 10.0 mg/ ml. The relative standard deviation of intra- and inter-day assays was lower than 5%. The average recovery of ofloxacin from plasma was 93%. The method was evaluated in samples from healthy subjects whose drug levels were already measured by microbiological assay. Ó 2001 Elsevier Science B.V. All rights reserved

Disposition of uric acid upon administration of ofloxacin alone and in combination with other anti-tuberculosis drugs

Disposition of uric acid upon administration of ofloxacin (O) alone and in combination with other anti-tuberculosis drugs, rifampicin (R), isoniazid (H) and pyrazinamide (Z) was studied. Twelve male healthy volunteers were investigated on four different occasions with the four drugs alone or in combinations. A partially balanced incomplete block design was adopted and the subjects were randomly allocated to each group. Uric acid concentration in urine samples excreted over 0-8 hr, were determined after coding the samples. There was significant decrease in the group receiving Z when compared to other groups. Though there was a decrease in uric acid excretion in the group receiving O, it was not statistically significant. Rifampicin and H seem to increase the uric acid excretion. The incidence of arthralgia was mainly due to Z and not due to either O or other drugs in the treatment of pulmonary tuberculosis

Ofloxacin pharmacokinetics in saliva

Objective: To study the pharmacokinetics of ofloxacin using salivary drug concentration when administered alone or in combination with rifampicin (R), isoniazid (H) and pyrazinamide (Z) and also to assess the saliva to plasma concentration ratio. Material and Methods: Twelve healthy male volunteers were investigated on four different occasions with an interval of at least one week between occasions. They were administered ofloxacin, either alone or in combination with R, H and Z. A partially balanced incomplete block design was adopted and the subjects were randomly allocated to each group. Salivary and plasma concentrations of ofloxacin were measured at 1, 2, 3, 6 and 8 h after drug(s) administration using validated methods. Results: There were no significant differences between various pharmacokinetic parameters when ofloxacin was administered alone or in combination with R, H and Z. The mean saliva to plasma ratio of ofloxacin concentration was around 0.6. The bioavailability indices of ofloxacin in the saliva and plasma were similar in all the groups. Conclusion: Several pharmacokinetic parameters could be calculated using salivary concentrations of ofloxacin. The determination of ofloxacin levels in saliva may be useful in therapeutic drug monitoring and pharmacokinetic studies