Precipitation Patterns and Trends in the Metropolitan Area of Milwaukee, Wisconsin

This study investigated changes in mean and extreme precipitation in the metropolitan area of Milwaukee, Wisconsin in an attempt to find the effects of urban areas on precipitation patterns. Precipitation data were obtained from a gridded (8-km spacing) historical climatic dataset for Wisconsin for 1950-2006. The Mann-Kendall test and the Sen’s slope test were applied to investigate temporal trends. Monthly wind directions were examined against monthly precipitation patterns. Main findings from the study include the following: (1) Annual precipitation significantly increased in the northern part of the study area during 1950-2006, whereas extreme precipitation showed virtually no trends; (2) The metropolitan area showed a distinctive center of low precipitation in selected months; (3) Extreme precipitation showed a more localized pattern than annual precipitation; and (4) Wind directions reasonably explained the spatial distributions of monthly precipitation with respect to the urban area. The results suggest signals of urban influence on precipitation, which need to be corroborated by more detailed investigation on precipitation characteristics

Decadal Changes and Future Projections of Precipitation in the Metropolitan Area of Milwaukee

This research investigated decadal changes and future projections of precipitation in the Metro Milwaukee and surrounding area, the largest urban area in Wisconsin. Spatial and temporal precipitation patterns derived for the Metro Milwaukee from the high-resolution gridded historical climatic dataset for Wisconsin were analyzed for 1950-2006. In addition, precipitation scenarios were generated via statistical downscaling of the Third Generation Coupled Global Climate Model (CGCM3) outputs. The delta method was chosen for the statistical downscaling of the CGCM3 output for the two future time periods, 2041-2070 (2050s) and 2071-2100 (2080s). The Mann-Kendall test and the Sen\u27s slope test were applied to investigate trends of annual and extreme precipitation. The gridded historical data were interpolated with an inverse distance weighting algorithm for spatial analysis. The annual precipitation was projected to increase by 6% to 14% by the 2050s and by 8% to 12% by the 2080s. The regional analysis of annual precipitation showed that the northern regions receive less precipitation compared to the average of the study area, and the southern regions receive more. The 95th percentile of each year\u27s daily total precipitation was projected to increase in the future. The projected changes in extreme precipitation were higher than those simulated for the annual precipitation changes. Based on the spatial patterns of annual and monthly precipitation, and the predominant wind direction, a pattern of higher precipitation amounts down-wind from the city could be observed for the historical climate dataset for 1950-2006

A semantics based interactive query formulation technique

We present an interactive query formulation technique which enables exploitation not only of structural properties of data but also of semantic constraints as posed by the contents of data. The technique aims at the formulation of a semantically consistent or meaningful query by the end-user without any previous knowledge of syntax formalisms and data model semantics. This has been achieved by end-user guidance in that an inference engine suggests semantically rich query terms for further consideration by the end-user. The set of suggested terms at each interaction stage comply with the already considered query terms with respect to structure and contents based semantics. Assignment or selection of operational terms are also allowed, if operational semantics comply with the semantics of data. The interactive query formulation component has been implemented in Java and runs on the client side of a client/server based query answering system architecture

Air Temperature Variability in Illinois Based on Weather Station Records and the North American Regional Reanalysis from 1979 to 2006

Spatial and temporal near-surface air temperature 21 variabilities and trends were analyzed for 30 locations in Illinois based on annual data derived from station records and the North American Regional Reanalysis (NARR) dataset from 1979 to 2006. A high correlation was found between the two datasets regarding interannual variability at most locations. Temperatures were generally higher at urban stations than non-urban stations while non-urban NARR data points showed higher temperatures than urban data points. The differences in medians were not statistically significant in either dataset. Significant positive temperature trends were found in the majority of the weather stations and in all NARR data points, with generally stronger trends with the NARR data. Observed trends from the station records were generally stronger in metropolitan areas and weaker for non-urban areas while the reanalysis data did not show a remarkable difference between urban and non-urban trends

Thermal-vacuum testing of high-temperature electrical components

Thermal vacuum testing of high temperature electrical component

Experimental Investigation of Bond Strength under High Loading Rates

The structural behaviour of reinforced concrete is governed significantly by the transmission of forces between steel and concrete. The bond is of special importance for the overlapping joint and anchoring of the reinforcement, where rigid bond is required. It also plays an important role in the rotational capacity of plastic hinges, where a ductile bond behaviour is preferable. Similar to the mechanical properties of concrete and steel also the characteristics of their interaction changes with the velocity of the applied loading. For smooth steel bars with its main bond mechanisms of adhesion and friction, nearly no influence of loading rate is reported in literature. In contrast, a high rate dependence can be found for the nowadays mainly used deformed bars. For mechanical interlock, where ribs of the reinforcing steel are bracing concrete material surrounding the bar, one reason can be assumed to be in direct connection with the increase of concrete compressive strength. For splitting failure of bond, characterized by the concrete tensile strength, an even higher dynamic increase is observed. For the design of Structures exposed to blast or impact loading the knowledge of a rate dependent bond stress-slip relationship is required to consider safety and economical aspects at the same time. The bond behaviour of reinforced concrete has been investigated with different experimental methods at the University of the Bundeswehr Munich (UniBw) and the Joint Research Centre (JRC) in Ispra. Both static and dynamic tests have been carried out, where innovative experimental apparatuses have been used. The bond stress-slip relationship and maximum pull-out-forces for varying diameter of the bar, concrete compressive strength and loading rates have been obtained. It is expected that these experimental results will contribute to a better understanding of the rate dependent bond behaviour and will serve for calibration of numerical models.JRC.G.4-European laboratory for structural assessmen

Modelling the bond between concrete and reinforcing steel in a fire

This is the post-print version of the final paper published in Engineering Structures. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2010 Elsevier B.V.A non-linear procedure is presented for modelling the bond characteristic between concrete and reinforcing steel for reinforced concrete structures in a fire. The accuracy and reliability of the model are demonstrated by the analysis of one pull-out test and one beam test at ambient temperature and four full-scale beams tested under two fire conditions. The model is clearly capable of predicting the response of reinforced concrete members and structures in a fire with acceptable accuracy. The bond-link element has been found to have good computational stability and efficiency for 3D analysis of reinforced concrete structures in fires. It is shown that the bond condition between the concrete and reinforcing steel bar has an important influence on the fire resistance of reinforced concrete structures, especially when the temperature of the reinforcing steel bar is high (more than 500 °C). Hence, the current assumption of a perfect bond condition for analysis of reinforced concrete structures under fire conditions is unconservative

Use of Steel Fiber Reinforced Concrete for the Protection of Buildings Against High Dynamic Actions

Nowadays ensuring the safety of people and the protection of infrastructure is a socially relevant topic, which requires a thorough investigation. The Institute of concrete construction at the University of the German Armed Forces in Munich is investigating the possibilities of using steel fiber concrete for the protection of military facilities and state-owned special buildings in Germany. In this research project steel fiber reinforced concrete is investigated under high dynamic loads specifically under contact detonation loading. Plates with varying reinforcement systems, different thicknesses, different fiber geometries, fiber contents and fiber types were produced.The following concrete compressive strengths C20/25, C40/50, C80/95 were used in this research project.The plates were loaded with 500 g, 750 g, 1000 g, 1500 g and 2000 g PETN explosive at the test facility of the German Armed Forces Technical centre for Protective and Special Technologies. An important property of construction material during ballistic threats and contact detonation is the concrete tensile strength. Through the addition of fibers, the post cracking behavior and the ductility of concrete components can be improved. All fiber-reinforced specimens showed less damage than the non-fiber reinforced elements. The aim of the study is to optimize the concrete mixture for the fiber concrete protection components considering the following factors: concrete quality, fiber content, fiber geometry, as well as aggregate size of the concrete. Another aim is to record and evaluate the damage parameters of the steel fiber reinforced concrete slabs after the highly dynamic load, and to investigate to offer suggestion for retrofitting. In this article, the test results of different steel framed concretes under highly dynamic conditions are presented

IgG seroprevalence of COVID-19 among people living with HIV or at high risk of HIV in south-west Germany: A seroprevalence study

Objectives: Seroprevalence studies of SARS-CoV-2 have shown that there is a high number of undiagnosed missing cases. Seroprevalence of SARS-CoV-2 in people living with HIV (PLWH) is lacking. Therefore, we conducted a prospective cross-sectional study to estimate the seroprevalence of SARS-CoV-2 among PLWH without known diagnosis of COVID-19 in the south-west of Germany. Methods: Serological testing for SARS-CoV-2 immunoglobulin G (IgG) antibodies based on two assays was performed in PLWH who visited the outpatient HIV centre of two hospitals from April to June 2020. Additionally, patients had to answer questionnaires about possible COVID-19-related symptoms and predefined risk factors. Moreover, we tested 50 non-HIV-infected patients receiving post- or pre-exposure (PEP/PrEP) HIV prophylaxis. Results: In all, 594 (488 male, 106 female) PLWH (median age 51 years) and 50 PEP/PrEP-users were included in the study. The estimated seroprevalence of the PLWH cohort was 1.85% (11/594), with 11 positive tested cases in the cohort. Among all patients, only five had COVID-19-related symptoms. One PCRpositive patient did not show any antibody response in repeatedly carried out tests. None of the patients was hospitalized due to COVID-19. Three PrEP users were tested positive. Three patients had been previously diagnosed with SARSCOV-2 infection before inclusion. The used questionnaire did not help to detect SARS-CoV-2 positive patients. Conclusions: Despite the limitation of being only a snapshot in time because of the ongoing pandemic, to our knowledge this is the largest study so far on seroprevalence of SARS-CoV-2 in PLWH in Germany. Our study suggests that the seroprevalence of SARS-CoV-2 in PLWH is comparable to those previously reported for parts of the general German population and that the questionnaire used here might not be the best tool to predict COVID-19 diagnosis