Data Points and Duration for Estimating Fuel Consumption of a Diesel Engine

Accurate measurement of fuel consumption is required to quantify the efficiency of an engine or predict emissions. As part of a larger project, accurate instantaneous fuel consumption data was required for a John Deere 4045T diesel engine. While establishing test criteria, it became evident that literature did not provide clear recommendations on the number of data points or time duration for data collection, for a diesel engine. Fuel consumption tests were conducted using up to 15 data points of percent fuel rate and up to 15 min of data collection. Based on statistical analysis of test results, at least 2 data points (0% and 100% of fuel rate) and 2 min of data collection are recommended for similar fuel-injected, diesel engine fuel rate tests. When a nonfuel injected engine is used, the Hogan et al. (2007) recommendation of at least 3 data points and 3.5 min of data collection should be followed

Comparative Models of Hydrocarbon Emissions for a Diesel Engine Operating at Constant Loads and Speeds

Linear multiple regression (LMR) and nonlinear polynomial network (NPN) models were developed from data collected from ISO 8178‐4 (1996) test cycle B‐type tests (ISO) and an expanded set of tests (EXP) to predict hydrocarbon (HC) emissions from a diesel engine. LMR using the ISO training data (R2 = 0.94) resulted in overfitting of the model as applied to the evaluation data (R2 = 0.49). LMR based on the expanded data (R2 = 0.68) was a better LMR model when applied to the evaluation data (R2 = 0.64). NPN using the expanded training data (R2 = 0.99) resulted in the best model when applied to the evaluation data (R2 = 0.98) and is preferred for predicting HC when the larger set of test mode data are available. NPN using the ISO training data (R2 = 0.99) resulted in a satisfactory fit for the evaluation data (R2 = 0.91), although with a higher average absolute error (0.52 vs. 0.42 g/kWh) than NPN using the EXP training data. This model was also considered suitable for predicting HC. Results of this initial study suggest that data could be collected during ISO 8178‐4 emission tests and modeled with NPN to predict HC emissions for a diesel engine operating at various constant speeds and loads

Modeling NO Emissions of an Off-road Diesel Engine Based on Emission Tests

Emissions values determined by the ISO 8178 emission certification tests do not necessarily represent emissions of a tractor in operation (Hansson et al., 2001). Rather than using ISO 8178 tests solely for certification, data collected during the tests may be suitable for predicting nitrogen oxide (NOx) emissions of an engine operating at constant loads and speeds. Linear multiple regression (LMR) and nonlinear polynomial network (NPN) models were developed with data collected from ISO 8178-4 (1996) test cycle B-type tests (ISO) and an expanded set of tests (EXP) to predict NOx emissions from a diesel engine. LMR using the ISO training data (R2 = 0.94) resulted in over-training of the model, as applied to the evaluation data (R2 = 0.51). LMR based on the expanded data (R2 = 0.60) was a better LMR model, when applied to the evaluation data (R2 = 0.73). NPN using the ISO training data (R2 = 0.99) resulted in a considerable improvement over the LMR models for the evaluation data (R2 = 0.81). NPN using the EXP training data (R2 = 0.96) resulted in the best model when applied to the evaluation data (R2 = 0.95). When applied to the evaluation data, the mean absolute error of the NPN EXP based model was significantly less than from the NPN ISO based model. The NPN model based on EXP data is recommended for predicting NOx. Data could be collected during ISO 8178-4 emission tests that included additional test modes and modeled with NPN to predict NOx emissions for a diesel engine operating at various constant speeds and loads

Data Points and Duration for Estimating Fuel Consumption of a Diesel Engine

Accurate measurement of fuel consumption is required to quantify the efficiency of an engine orpredict emissions. As part of a larger project, accurate instantaneous fuel consumption data was required for a John Deere 4045T diesel engine. While establishing test criteria, it became evident that literature did not provide clear recommendations on the number of data points or time duration for data collection, for a diesel engine. Fuel consumption tests were conducted using up to 15 data points of percent fuel rate and up to 15 min of data collection. ased on statistical analysis of test results, at least 2 data points (0% and 100% of fuel rate) and 2 min of data collection are recommended for similar fuel-injected, diesel engine fuel rate tests. When a nonfuel injected engine is used, the Hogan et al. (2007) recommendation of at least 3 data points and 3.5 min of data collection should be followed

Concerns of Custom Harvesters

This study elicited the perceptions and concerns of custom harvesters regarding safety and health issues faced in their operations, self‐perceived knowledge of selected regulations, and self‐perceived ability to train employees on the safe operation of equipment. The average age of custom harvesters\u27 (CH) employees was 22 to 25 years (47.2%). The most common length of the harvest season was 5 to 6 months (70.9%). The most common responses to length of work day were 9 to 11 hours (34.5%) and 12 to 14 hours (54.5%). In general, CH ranked combine operation experience as most important when hiring employees. The CH felt inexperience was the leading contributor to lost‐time incidents. They were most concerned about DOT regulations and Worker\u27s Compensation rules, but also felt they had a good knowledge of those areas

The Passive Journalist: How sources dominate the local news

This study explores which sources are “making” local news and whether these sources are simply indicating the type of news that appears, or are shaping newspaper coverage. It provides an empirical record of the extent to which sources are able to dominate news coverage from which future trends in local journalism can be measured. The type and number of sources used in 2979 sampled news stories in four West Yorkshire papers, representing the three main proprietors of local newspapers in the United Kingdom, were recorded for one month and revealed the relatively narrow range of routine sources; 76 per cent of articles cited only a single source. The analysis indicates that journalists are relying less on their readers for news, and that stories of little consequence are being elevated to significant positions, or are filling news pages at the expense of more important stories. Additionally, the reliance on a single source means that alternative views and perspectives relevant to the readership are being overlooked. Journalists are becoming more passive, mere processors of one-sided information or bland copy dictated by sources. These trends indicate poor journalistic standards and may be exacerbating declining local newspaper sales

Uniform or Sex-Specific Cardiac Troponin Thresholds to Rule-out Myocardial Infarction at Presentation

Background: Myocardial infarction can be ruled out in patients with a single cardiac troponin measurement. Whether use of a uniform rule-out threshold has resulted in sex-differences in care remains unclear.Objectives: To evaluate implementation of a uniform rule-out threshold in females and males with possible myocardial infarction, and to derive and validate sex-specific thresholds. Methods: The implementation of a uniform rule-out threshold (&lt;5 ng/L) with a high-sensitivity cardiac troponin I assay was evaluated in consecutive patients presenting with possible myocardial infarction. The proportion of low-risk patients discharged from Emergency Department (ED) and incidence of myocardial infarction or cardiac death at 30 days were determined. Sex-specific thresholds were derived and validated, and proportion of female and male patients stratified as low-risk compared with uniform threshold.Results: In 16,792 patients (58±17 years, 46% female) care was guided using a uniform threshold. This identified more female than male patients as low-risk (73% versus 62%), but a similar proportion of low-risk patients were discharged from ED (81% for both) with fewer than 5 (&lt;0.1%) patients having a subsequent myocardial infarction or cardiac death at 30 days. Compared to uniform threshold of &lt;5 ng/L, use of sex-specific thresholds would increase the proportion of female (61.8% versus 65.9%) and reduce the proportion of male (54.8% versus 47.8%) patients identified as low-risk.Conclusions: Implementation of a uniform rule-out threshold for myocardial infarction was safe and effective in both sexes. Sex-specific rule-out thresholds should be considered, but their impact on effectiveness and safety may be limited.Keywords: Cardiac troponin, sex, myocardial infarction<br/

Genetic mechanisms of critical illness in COVID-19.

Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice

Common, low-frequency, rare, and ultra-rare coding variants contribute to COVID-19 severity

The combined impact of common and rare exonic variants in COVID-19 host genetics is currently insufficiently understood. Here, common and rare variants from whole-exome sequencing data of about 4000 SARS-CoV-2-positive individuals were used to define an interpretable machine-learning model for predicting COVID-19 severity. First, variants were converted into separate sets of Boolean features, depending on the absence or the presence of variants in each gene. An ensemble of LASSO logistic regression models was used to identify the most informative Boolean features with respect to the genetic bases of severity. The Boolean features selected by these logistic models were combined into an Integrated PolyGenic Score that offers a synthetic and interpretable index for describing the contribution of host genetics in COVID-19 severity, as demonstrated through testing in several independent cohorts. Selected features belong to ultra-rare, rare, low-frequency, and common variants, including those in linkage disequilibrium with known GWAS loci. Noteworthily, around one quarter of the selected genes are sex-specific. Pathway analysis of the selected genes associated with COVID-19 severity reflected the multi-organ nature of the disease. The proposed model might provide useful information for developing diagnostics and therapeutics, while also being able to guide bedside disease management. © 2021, The Author(s)