Exploring the Injury Severity Risk Factors in Fatal Crashes with Neural Network

A better understanding of circumstances contributing to the severity outcome of traffic crashes is an important goal of road safety studies. An in-depth crash injury severity analysis is vital for the proactive implementation of appropriate mitigation strategies. This study proposes an improved feed-forward neural network (FFNN) model for predicting injury severity associated with individual crashes using three years (2017–2019) of crash data collected along 15 rural highways in the Kingdom of Saudi Arabia (KSA). A total of 12,566 crashes were recorded during the study period with a binary injury severity outcome (fatal or non-fatal injury) for the variable to be predicted. FFNN architecture with back-propagation (BP) as a training algorithm, logistic as activation function, and six number of hidden neurons in the hidden layer yielded the best model performance. Results of model prediction for the test data were analyzed using different evaluation metrics such as overall accuracy, sensitivity, and specificity. Prediction results showed the adequacy and robust performance of the proposed method. A detailed sensitivity analysis of the optimized NN was also performed to show the impact and relative influence of different predictor variables on resulting crash injury severity. The sensitivity analysis results indicated that factors such as traffic volume, average travel speeds, weather conditions, on-site damage conditions, road and vehicle type, and involvement of pedestrians are the most sensitive variables. The methods applied in this study could be used in big data analysis of crash data, which can serve as a rapid-useful tool for policymakers to improve highway safety

Nano and microscale contact characteristics of tribofilms derived from fully formulated engine oil

A systematic approach is required in order to determine the frictional characteristics of a contacting pair in the presence of a tribofilm. Despite the clear benefits in functionality and in reducing wear, the generation of ZDDP-based tribofilms often lead to increased frictional losses. Such an increase is also observed in the tribometric tests reported here, as well as in open literature. This paper investigates the underlying mechanics for the rise in friction using an integrated methodology, based upon Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). The use of an analytical contact mechanics model demonstrates that the pressure coefficient of boundary shear strength, measured using lateral force microscopy, provides an explanation for the observed increase in measured friction at micro-scale

Lubricant base stock-surface interaction

Superior performance is by far the most desirable aspect of any Spark Ignition (SI) engine that is designed for competition use. This is closely followed by a predictable life expectancy of the unit. A major aspect that can seriously affect both performance and longevity of the unit are the frictional losses and wear of the reciprocating components within the engine. One of the major areas where frictional losses and excessive wear that can reduce performance at an alarming rate is the first compression ring/cylinder liner interface. This investigation uses lateral force microscopy to determine the congruity of matching individual base stock components to liner material/substrate combinations

Morphology of the proximal femur in a Pakistani population

Purpose: To measure the morphology of the proximal femur in a Pakistani population. Methods: Standardised anteroposterior pelvic radiographs of 116 male and 20 female healthy volunteers aged 20 to 50 (mean, 33) years were taken. Morphologic dimensions of the proximal femur were measured, including canal flare index (CFI), morphological cortical index (MCI), femoral head offset, femoral head diameter, and femoral head position. Results: Based on the CFI, 67% of the subjects had normal canal shapes (CFI, 3.0-4.7), whereas 1% and 33% of the subjects had stovepipe shapes (CFI,2.7). Conclusions: Morphology of the proximal femur in our study population differed significantly from those in western populations, indicating regional variation. It could also be due to the younger age of our population

Tribological investigation of organic and inorganic friction modifiers with varying quantities of dispersants [Abstract]

Tribological investigation of organic and inorganic friction modifiers with varying quantities of dispersants [Abstract

current state of poison control centers in Pakistan and the need for capacity building.

Background: Chemical exposure is a major health problem globally. Poison control centers (PCCs) play a leading role both in developed and developing countries in the prevention and control of poisonous chemical exposures. In this study, we aimed to assess the current state of PCCs in Pakistan and highlight capacity building needs in these centers. Methods: A cross-sectional survey of the two registered PCCs was done during August – December 2011. Necessary services of the PCCs were evaluated and the data were recorded on a predesigned checklist. Results: Both PCCs are affiliated to a tertiary care hospital. Clinical services to poisoned patients were available 24 hours a day / 7 days a week. Information on common local products was available to poison center staff. Both centers were involved in undergraduate and post graduate teaching. Telephone poison information service was not available in either of centers. There was a limited capacity for qualitative and analytical toxicology. Common antidotes were available. There were limited surveillance activities to capture toxic risks existing in the community and also a deficiency was observed in chemical disaster planning. Conclusion: PCCs in Pakistan need capacity building for specialized training in toxicology, toxicovigilance, chemical disaster planning, analytical laboratory tests and telephone service for consultation in poisoning cases

Performance Evaluation of Plastic Concrete Modified with E-Waste Plastic as a Partial Replacement of Coarse Aggregate

Plastic electronic waste (E-waste) is constantly growing around the world owing to the rapid increase in industrialization, urbanization, and population. The current annual production rate of E-waste is 3–4% in the world and is expected to increase to 55 million tons per year by 2025. To reduce the detrimental impact on the environment and save natural resources, one of the best solutions is to incorporate waste plastic in the construction industry to produce green concrete. This study examines the use of manufactured plastic coarse aggregate (PCA) obtained from E-waste as a partial replacement of natural coarse aggregate (NCA) in concrete. Six types of concrete mix with 10%, 20%, 30%, 40%, and 50% substitution of NCA (by volume) with PCA are prepared and tested. This study investigates the effect of manufactured PCA on the fresh and hardened characteristics of concrete. The properties of recycled plastic aggregate concrete (RPAC) studied include workability, fresh density, dry density, compressive strength (CS), splitting tensile strength (STS), flexural strength (FS), sorptivity coefficient, abrasion resistance, ultrasonic pulse velocity (UPV), and alternate wetting and drying (W–D). The results indicate that the CS, STS, and FS of RPAC declined in the range of 9.9–52.7%, 7.8–47.5%, and 11–39.4%, respectively, for substitution ratios of 10–50%. However, the results also indicate that the incorporation of PCA (10–50%) improved the workability and durability characteristics of concrete. A significant decrement in the sorptivity coefficient, abrasion loss, and UPV value was observed with an increasing amount of PCA. Furthermore, RPAC containing different percentages of PCA revealed better results against alternate W–D cycles with respect to ordinary concrete

Characterisation of automotive bore material and coatings using atomic force microscopy [Abstract]

Characterisation of automotive bore material and coatings using atomic force microscopy [Abstract

Asperity level frictional interactions of cylinder bore materials and lubricant composition

Parasitic frictional losses in internal combustion engines of race vehicles adversely affect their performance. A significant proportion of these losses occur within the piston-cylinder system. This paper presents a study of the compatibility of cylinder bore surface materials with typical lubricant base constituent stock (Poly Alpha Olefin (PAO) and Polyolester (POE)) as well as a fully formulated lubricant. Nanoscale boundary friction is measured using lateral force microscopy. The effect of material properties, nanoscale roughness and lubricant species upon underlying mechanisms of generated friction is presented. Advanced cylinder materials and coatings and lubricant molecular species used for high performance engines are investigated, an integrated approach not hitherto reported in literature