Development of response surface method prediction model for traffic-related roadside noise levels based on traffic characteristics.

Recently, several urban areas are trying to mitigate the environmental impacts of traffic, where noise pollution is one of the main consequences. Thus, studying the determinants of traffic-related noise generation and developing a model that predicts the level of noise by controlling the influencing factors are crucial for transportation planning purposes. This research aims at utilizing the response surface method (RSM) to develop a robust statistical prediction model of traffic-related noise levels and optimize different traffic characteristics' ranges to reduce the expected noise levels. The results indicate that the rate of Leq increase is higher at traffic flow values less than the 1204 veh/h. The interaction effect of flow-speed and flow-heavy vehicle percentage pairs shows that Leq has peak values around 45.8 km/h and 28.71%, respectively, with almost symmetric value distribution about those center points. The main effects study indicates a direct effect of traffic flow, speed, density, and traffic composition on roadside noise levels. The prediction model has good representativeness of observed noise levels by predicted noise levels as the model has a high coefficient of determination (R2 = 95.87% and R2 adj = 92.26%) with a significance level of 0.0036. Then, the research presents a methodology to perform an optimization of the roadside noise level by defining traffic characteristics that can keep the noise level below 65 dB(A) or minimize noise level. Decision-makers could use the proposed method to control the roadside noise level.

Impact of land use, travel behavior, and socio-economic characteristics on carbon emissions in cool-climate cities, USA.

US cities of cool-climate zone such as Chicago and Boston are witnessing a reduction in carbon emissions potentially due to promoting public transportation and alternative energy resources. It is difficult to validate or deny optimal integration between land-use practices and transportation policies in mitigating carbon emissions due to the lack of urban comparative studies among metropolitan areas. Therefore, this research aims to examine the relationship between land use, travel behavior, and socio-economic characteristics related to carbon dioxide emissions at the zip code level. The research tends to investigate the carbon emissions in four metropolitan regions in cool climatic zone 5 compared to the carbon emissions in all US zip codes, to generate benchmarking predictive models. To this end, nine regression models were developed in this research. These include the US data model, zone 5 model, zone 5 cities model, zone 5 metropolitan areas model, zone 5 micropolitan areas model, Boston model, Chicago model, Columbus model, and Detroit model considering 14 independent variables. The nine models were calibrated and evaluated to include the statistically significant variables having the expected logical sign and acceptable values for t-statistic and multicollinearity. The adjusted R2 values vary between 0.62 and 0.91, where Boston, Chicago, Columbus, and Detroit models are statistically better than other models. The results indicate that the policies that can be adopted to reduce carbon emissions vary among the models.

Open Versus Closed Pleura Internal Mammary Artery Harvesting and Early Pulmonary Function After Coronary Artery Bypass Grafting.

BACKGROUND: The internal mammary artery is the vessel of choice for myocardial revascularisation during coronary artery bypass grafting (CABG). Although it is possible to harvest the left internal mammary artery (LIMA) without opening the left pleura, pleurotomy is usually performed to provide adequate exposure and allow the placement of the LIMA medial to the upper lobe, preventing any undue tension on the mammary pedicle. However, the intact pleura technique may have a lower risk of postoperative pulmonary complications. We aimed to study the effects of both procedures on pulmonary function and the incidence of complications. METHOD: One hundred patients with ischaemic heart disease indicated for CABG were included and divided into two groups. The closed pleural technique group included 50 patients with preservation of the pleural integrity during mammary harvesting. The open pleural procedure group included 50 patients without preservation of pleural integrity. Spirometry was done pre- and postoperatively in both groups and postoperative pulmonary complications in both groups were recorded and analysed. RESULTS: Internal mammary harvesting with preservation of pleural integrity during CABG in patients in the closed pleural procedure group showed significant improvement in forced expiratory volume in the first second (FEV1%), forced vital capacity (FVC%), and FEV1/FVC compared with the corresponding values in patients in the open pleural procedure group, on day 5 postoperatively, at discharge, and at day 30. There were fewer complications in preservation of pleural integrity with regard to lung atelectasis and pleural effusion, which were significantly lower in patients in the open pleural procedure group. CONCLUSIONS: Preservation of pleural integrity has beneficial effects on pulmonary function and has fewer associated pulmonary complications.

Develop dynamic model for predicting traffic CO emissions in urban areas.

The greater the use of energy in the transportation sectors, the higher the emission of carbon monoxide (CO), and hence inevitable harm to environment and human health. In this concern, measuring and predicting of CO emission from transportation sector-especially large cities-is important as it constitute 90 % of all CO emission. Many urban cities in developing world have not properly experienced such measurements or predictions. In this paper, for the first time, field measurements of traffic characteristics data and corresponding CO concentration have been performed for developing a model for predicting CO emissions from transportation sector for New Borg El Arab (NBC), Egypt. The performance of Swiss-German Handbook Emission Factors for Road Transport (HBEFA v3.1) model has been assessed for predicting the CO concentration at roadside in the study area. Results indicated that HBEFA v3.1 underestimate emission figures. The developed CO dynamic emission model involves the traffic flow characteristics with roadside CO concentrations. Acceptable representation of measured CO concentration has been shown by the developed dynamic CO emission model which introduces R (2) = 0.77, mean biases and frictional biases of -0.27 mg m(-3) and 0.09, respectively. A comparison between predicted CO concentrations using HBEFA v3.1 and the promoted dynamic model indicate that HBEFA v3.1 estimates CO emission concentrations in the study area with a mean error and frictional biases 159.26 and 233.33 %, respectively, higher than those of the developed model.