Heavy trucks are believed to experience increased delays when entering congested roundabouts due to their increased size and more restrictive operating characteristics as compared to passenger cars. The present study evaluated 164 h of video data to transcribe 2,626 heavy truck movements at single-lane roundabouts across Oregon and Washington. Gap acceptance and gap rejection timings were evaluated to quantify heavy truck accessibility when entering congested roundabouts. Further, a variety of heavy truck classifications were observed and evaluated individually, with the most common being the WB-40, WB-50, WB-62, WB-67, WB-67D, and WB-92D. Within each of these classifications, gap acceptance behavior differed. Average rejected gap lengths were 3.84 s, while average accepted gap lengths were 8.69 s, indicating heavy trucks often accepted gaps that were over two times larger than the prior gaps. Critical gap length assessment was carried out following Raff's method on an individual-classification basis to compare critical gaps across heavy truck classifications. Critical gap lengths for heavy trucks ranged from 5.4 to 6.4 s, approximately two to three times larger than that of passenger car critical gap values of 2.2 and 2.6 s documented in prior research. Additionally, heavy truck critical gap requirements were found to increase proportionately with the heavy truck size. The WB-40 was the smallest heavy truck assessed and was found to have a critical gap of 5.4 s. Conversely, the WB-92D was the largest heavy truck and was associated with a critical gap of 6.4 s. These findings indicate that roundabout locations featuring high heavy truck volumes may need additional considerations due to the operational restrictions of these larger vehicles, and that the assessment of roundabout implementation should include analysis of the vehicle classifications using these facilities to most optimally design for the current and future demand.
Growth and development in children and adolescents are dynamic, interrelated processes that reflect both genetic and environmental influences. Anthropometric assessment and somatotype classification are essential tools for evaluating these processes, offering insights into body composition, health risks, and physical performance. Somatotype, defined by three components: endomorphy (fat), mesomorphy (muscle), and ectomorphy (linearity) provides a standardized method to describe physique and its variations across age and sex. This paper reviews growth patterns, the historical development of somatotyping methods, and their application in children and adolescents. Evidence shows that somatotype characteristics vary significantly during puberty: endomorphy tends to increase in females, while mesomorphy predominates in males, particularly in late adolescence. Ectomorphy peaks during periods of rapid height growth, then declines with advancing age. These shifts are influenced by hormonal changes, nutrition, physical activity, and socio-economic factors. Understanding somatotype development has clinical and applied relevance. It assists in monitoring population health, identifying risks of obesity and related metabolic conditions, and guiding individualized approaches in sports and physical education. While somatotype is strongly determined by genetic factors, lifestyle interventions especially balanced nutrition and regular physical activity can improve body composition and overall health outcomes.
The European Union’s Horizon 2020 programme has funded the SENS4ICE (Sensors for Certifiable Hybrid Architectures for Safer Aviation in Icing Environment) project [1], an innovative approach for the development and testing of new sensors for the detection of supercooled large droplets (SLD). SLD may impinge behind the protected surfaces of aircraft and therefore represents a threat to aviation safety. The newly developed sensors will be tested in combination with an indirect detection method on two aircraft, in two parallel flight programs: One on the Embraer Phenom 300 in the U.S. and one on the ATR-42 in Europe.In this framework the Deutsches Zentrum für Luft- und Raumfahrt (German Aerospace Center) is in charge of the airborne measurements and data evaluation of the microphysical properties of clouds encountered during the SENS4ICE field campaigns in February, March and April 2023. We present the instrumentation that is used in the flight experiments for the characterization of icing environments and for the validation and performance assessment of new sensors for the detection and discrimination of Appendix O and Appendix C conditions [2, 3].Further, with partners from Centre Europeen De Recherche Et De Formation Avancee En Calcul Scientifique (CERFACS), the German Weather Service (DWD), the Italian Aerospace Research Center (CIRA) and Leading Edge Atmospherics (LEA), we present the considerations that were undertaken to find the best campaign location with highest frequency of icing occurrence on a climatological basis, taking into account the safety requirements of the aircraft. Four data sets of icing conditions based on various meteorological input data (model and observations) have been analyzed to provide an overview of the occurrence of icing. The data give a good impression on the geographical and vertical distribution of icing conditions above Europe and the Northern U.S. in general and specifically at higher altitudes (> 750 hPa or 8000ft) for the European campaign. We find enhanced icing frequencies between 1 to 5% at altitudes between 2 and 6 km even in the spring, summer and autumn months above Europe.We show highlights from selected individual cases from the North American test campaign performed in February and March 2023. The analysis gives a first impression of the extensive data set of icing conditions made available by the SENS4ICE project for sensor evaluation and for validation of satellite observations and model forecasts.
The chapter reviews key foundations and principles of the burgeoning discipline of executive or leadership coaching and explores how these relate to the practice, profession, and philosophy of engineering. In exploring and comparing objectives, approaches, cognitive preferences and future challenges of coaches and engineers, the authors identify a number of kindred properties between the two disciplines. This common ground would invite us to believe that engineering would naturally draw upon coaching for the development of its students, educators, and practitioners, but evidence shows that this is not the case. Although many late-stage engineers get coached upon reaching the C-suite or other high positions in the public or private sectors, early and mid-career engineers do not have ready access to the coaching support seen elsewhere. Equally, very few initiatives to integrate and tap into this resource are seen in the global engineering education system for academic leaders, educators, or engineering students in ways that would benefit future generations of engineers. This chapter aims at providing a possible explanation for this gap, whilst suggesting why and how coaching could possibly be the untapped resource that engineers may need to successfully meet the challenges and demands of today and tomorrow. The authors call on philosophers to join in the efforts, drawing out some key paths for collaboration and helpful future investigative questions.
Primary loop piping integrity is a regulatory and safety concern for the long-term operation (LTO) commercial light water reactor (LWR) nuclear power plants (NPPs). Typically, primary loop piping in existing LWRs was manufactured from cast or wrought austenitic stainless steel alloy material and operates at a pressure of ~2250 psi (16MPa) for a pressurized water reactor (PWR) design type and ~1000 psi (7 MPa) for a boiling water reactor (BWR). The objective of this research was to determine if measurement of surface strains can be used to characterize inner diameter flaws. For this feasibility study, wrought carbon steel Alloy A106 Grade B material was selected in lieu of stainless steel. This research was performed on pre-notched, 10 in. (25 cm) nominal outer diameter (OD) Schedule 120 (0.844 in. [21.4 mm) wall thickness) pipe samples of 24 in. (61 cm) length. The notches were made using electrical discharge machining (EDM) on the inner diameter (ID) of the pipe samples, with notch features two-dimensional (2D) and planar in nature to simulate cracking. The surface strains in the samples were evaluated under increasing hydrostatic pressure, up to a maximum of 2300 psi (16MPa) to determine their response to flaws with variable depth. Reusable end caps were utilized in lieu of welded caps for the pressure testing. This article describes the test procedure for the pressure testing and results of the feasibility study, which is the first phase of research with the end goal of the development of online crack monitoring capability for use at operating NPPs.
