Time analysis of composite beams with partial interaction using available modelling techniques: A comparative study

This paper presents a comparison of available numerical structural formulations for the short- and long-term analysis of composite beams with partial shear interaction. The finite difference method, the finite element method, the direct stiffness method and the exact analytical model have been considered, and both the instantaneous analysis and the time analysis based on the age-adjusted effective modulus method (AEMM) have been carried out. For modelling based on the first two of these formulations, a spatial discretisation and a discretisation in the time domain are required, while only the time discretisation needs to be specified for the direct stiffness method. The results obtained using these formulations are compared qualitatively and their accuracy is estimated, adopting the exact analytical model as a benchmark reference with the objective of establishing the minimum spatial discretisations required to keep the error within an acceptable tolerance. These comparisons are carried out for simply supported beams, propped cantilevers and fixed ended beams, from which the qualitative behaviour of these formulations in the modelling of continuous beams can also be deduced.     

Methodology for inventorying greenhouse gas emissions from global cities

This paper describes the methodology and data used to determine greenhouse gas (GHG) emissions attributable to ten cities or city-regions: Los Angeles County, Denver City and County, Greater Toronto, New York City, Greater London, Geneva Canton, Greater Prague, Barcelona, Cape Town and Bangkok. Equations for determining emissions are developed for contributions from: electricity; heating and industrial fuels; ground transportation fuels; air and marine fuels; industrial processes; and waste. Gasoline consumption is estimated using three approaches: from local fuel sales; by scaling from regional fuel sales; and from counts of vehicle kilometres travelled. A simplified version of an intergovernmental panel on climate change (IPCC) method for estimating the GHG emissions from landfill waste is applied. Three measures of overall emissions are suggested: (i) actual emissions within the boundary of the city; (ii) single process emissions (from a life-cycle perspective) associated with the city's metabolism; and (iii) life-cycle emissions associated with the city's metabolism. The results and analysis of the study will be published in a second paper.     

Estimating GHG emissions of marine ports—the case of Barcelona

In recent years, GHG inventories of cities have expanded to include extra-boundary activities that form part of the city's urban metabolism and economy. This paper centers on estimating the emissions due to seaports, in such a way that they can be included as part of the city's inventory or be used by the port itself to monitor their policy and technology improvements for mitigating climate change. We propose the indicators GHG emissions per ton of cargo handled or per passenger and emissions per value of cargo handled as practical measures for policy making and emission prevention measures to be monitored over time. Adapting existing methodologies to the Port of Barcelona, we calculated a total of 331,390 tons of GHG emissions (CO₂ equivalents) for the year of 2008, half of which were attributed to vessel movement (sea-based emissions) and the other half to port, land related activities (land-based emissions). The highest polluters were auto carriers with 6 kg of GHG emissions per ton of cargo handled. Knowing the highest emitters, the port can take action to improve the ship's activities within the port limits, such as maneuvering and hotelling. With these results, the port and the city can also find ways to reduce the land-based emissions.     

Elastic-plastic state of torispherical heads

The value of the permissible pressure in torispherical heads is usually judged from the size of the permanent deformations after the first load cycle. The difficulty always lies in the determination of the maximum permanent strain caused by the pressure, as the strain depends on the changes of the elastic-plastic state. The elastic-plastic state of the heads can be, for example, found and well followed by the finite element method. Values obtained in this way are naturally valid only for the case examined. However, by extending the numerical investigations and by appropriately processing and evaluating the results certain regularities and generalizations can be recognized. On this basis certain approximations can be made, leading to a very simple and reliable calculation process.     

Significance of mental factors in paroxysmal ventricular tachycardias]

In this paper is reported on two cases of paroxysmal ventricular tachycardia. The clinical and paraclinical examinations did not reveal any organic heart disease, the psychological one, however, found a very severe neurotic personality disorder. Antiarrhythmic drugs were ineffective in both cases. Meanwhile one female patient went through a brief psychotherapy which dismissed the arrhythmia.     

Temperature measurement and machining damage in slotting of multidirectional CFRP laminate

Compared to metallic materials, carbon fiber-reinforced plastics (CFRPs) have lower thermal conductivity and minor thermal expansion coefficient. Despite this, their machining can generate accuracy errors if the cutting temperature is not controlled. In this paper, an experimental study of slotting of multidirectional CFRP laminate (G803/914) with three micrograin carbide burr tools with different geometries is considered in order to investigate tool-workpiece contact point temperature, chip temperature, machined surface damage, subsurface defects and tool degradation. The experiment is made on a computer numerical control (CNC) machine with cutting speed ranging from 80 to 200 m/min and feed per tooth from 0.008 to 0.060 mm/rev/tooth. The data were analyzed in order to establish empirical models showing the dependence of cutting temperature on tool geometry and cutting conditions. Based on the results, it is concluded that cutting speed is the factor influencing cutting temperature the most, the heat generated during slotting is removed mainly by chips and the chip temperature is greater than the tool-workpiece contact temperature of about 18.5°C on average for the three burr tools.     

Direct numerical integration of coupled one-dimensional Schrödinger equations

Physical problems which can usually be described with the help of sets of coupled second-order differential equations are outlined. In the case of scattering problems, the direct numerical integration of these equations is the unique method of obtaining a solution. For bound-state calculations this integration is in direct competition with powerful conventional techniques such as the variational principle and the standard matrix diagonalization. We are developing two methods for solving by direct integration the eigenvalue problem associated with sets of coupled one-dimensional Schrödinger equations. These methods are successfully used to calculate the bound states of nuclear three- and four-body systems with two-body pure central forces.     

Activation of the Monocyte/Macrophage System and Abnormal Blood Levels of Lymphocyte Subpopulations in Individuals with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis

Autism spectrum disorder (ASD) is a neurodevelopmental condition with a so far unknown etiology. Increasing evidence suggests that a state of systemic low-grade inflammation may be involved in the pathophysiology of this condition. However, studies investigating peripheral blood levels of immune cells, and/or of immune cell activation markers such as neopterin are lacking and have provided mixed findings. We performed a systematic review and meta-analysis of studies comparing total and differential white blood cell (WBC) counts, blood levels of lymphocyte subpopulations and of neopterin between individuals with ASD and typically developing (TD) controls (PROSPERO registration number: CRD CRD42019146472). Online searches covered publications from 1 January 1994 until 1 March 2022. Out of 1170 publication records identified, 25 studies were finally included. Random-effects meta-analyses were carried out, and sensitivity analyses were performed to control for potential moderators. Results: Individuals with ASD showed a significantly higher WBC count (k = 10, g = 0.29, p = 0.001, I² = 34%), significantly higher levels of neutrophils (k = 6, g = 0.29, p = 0.005, I² = 31%), monocytes (k = 11, g = 0.35, p < 0.001, I² = 54%), NK cells (k = 7, g = 0.36, p = 0.037, I² = 67%), Tc cells (k = 4, g = 0.73, p = 0.021, I² = 82%), and a significantly lower Th/Tc cells ratio (k = 3, g = −0.42, p = 0.008, I² = 0%), compared to TD controls. Subjects with ASD were also characterized by a significantly higher neutrophil-to-lymphocyte ratio (NLR) (k = 4, g = 0.69, p = 0.040, I² = 90%), and significantly higher neopterin levels (k = 3, g = 1.16, p = 0.001, I² = 97%) compared to TD controls. No significant differences were found with respect to the levels of lymphocytes, B cells, Th cells, Treg cells, and Th17 cells. Sensitivity analysis suggested that the findings for monocyte and neutrophil levels were robust, and independent of other factors, such as medication status, diagnostic criteria applied, and/or the difference in age or sex between subjects with ASD and TD controls. Taken together, our findings suggest the existence of a chronically (and systemically) activated inflammatory response system in, at least, a subgroup of individuals with ASD. This might have not only diagnostic, but also, therapeutic implications. However, larger longitudinal studies including more homogeneous samples and laboratory assessment methods and recording potential confounding factors such as body mass index, or the presence of comorbid psychiatric and/or medical conditions are urgently needed to confirm the findings.