scholarly journals Wood creep data collection and unbiased parameter identification of compliance functions

Holzforschung ◽  
2020 ◽  
Vol 74 (11) ◽  
pp. 1011-1020
Author(s):  
Danyang Tong ◽  
Susan Alexis Brown ◽  
David Corr ◽  
Gianluca Cusatis
Keyword(s):  
Parameter Identification ◽  
Prediction Models ◽  
Tall Buildings ◽  
Building Design ◽  
Parameter Distribution ◽  
Experimental Conditions ◽  
Global Emission ◽  
Wood Construction ◽  
Parameter Values

AbstractRising global emission have led to a renewed popularity of timber in building design, including timber-concrete tall buildings up to 18 stories. In spite of this surge in wood construction, there remains a gap in understanding of long-term structural behavior, particularly wood creep. Unlike concrete, code prescriptions for wood design are lacking in robust estimates for structural shortening. Models for wood creep have become increasingly necessary due to the potential for unforeseen shortening, especially with respect to differential shortening. These effects can have serious impacts as timber building heights continue to grow. This study lays the groundwork for wood compliance prediction models for use in timber design. A thorough review of wood creep studies was conducted and viable experimental results were compiled into a database. Studies were chosen based on correlation of experimental conditions with a realistic building environment. An unbiased parameter identification method, originally applied to concrete prediction models, was used to fit multiple compliance functions to each data curve. Based on individual curve fittings, statistical analysis was performed to determine the best fit function and average parameter values for the collective database. A power law trend in wood creep, with lognormal parameter distribution, was confirmed by the results.

scholarly journals Fire Protection in Various Types of Wooden Structures

2015 ◽  
Vol 11 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Stanislava Gašpercová ◽  
Linda Makovická Osvaldová
Keyword(s):  
Energy Efficient ◽  
Building Design ◽  
Solid Wood ◽  
Wood Construction ◽  
Efficient Construction ◽  
Fire Properties ◽  
Building Physics ◽  
Wooden Structures ◽  
Prototype Design

Abstract Design of new modern systems for low energy efficient construction in a passive, zero standard or energy-autonomous buildings, as well as the increased popularity of solid wood construction means intervention into the very structure of its statics, building physics, but also fire properties. Some prototype design solutions are not verified whether the tests, by good computational analysis or verification of long-term use of the building. In the context of changing standards in building design, new approaches are needed. If in wooden buildings the potential risk of fire is higher than other buildings, we need special methods, materials and practical skills.

scholarly journals Abnormal Liver Function Tests and Long-Term Outcomes in Patients Discharged after Acute Heart Failure

2021 ◽  
Vol 10 (8) ◽  
pp. 1730
Author(s):  
Hiroshi Miyama ◽  
Yasuyuki Shiraishi ◽  
Shun Kohsaka ◽  
Ayumi Goda ◽  
Yosuke Nishihata ◽  
...  
Keyword(s):  
Heart Failure ◽  
Liver Function ◽  
Liver Function Tests ◽  
Abnormal Liver Function ◽  
Adverse Outcomes ◽  
Long Term Outcomes ◽  
Function Tests ◽  
Parameter Values

Abnormal liver function tests (LFTs) are known to be associated with impaired clinical outcomes in heart failure (HF) patients. However, this implication varies with each single LFT panel. We aim to evaluate the long-term outcomes of acute HF (AHF) patients by assessing multiple LFT panels in combination. From a prospective multicenter registry in Japan, 1158 AHF patients who were successfully discharged were analyzed (mean age, 73.9 ± 13.5 years; men, 58%). LFTs (i.e., total bilirubin, aspartate aminotransferase or alanine aminotransferase, and alkaline phosphatase) at discharge were assessed; borderline and abnormal LFTs were defined as 1 and ≥2 parameter values above the normal range, respectively. The primary endpoint was composite of all-cause death or HF readmission. At the time of discharge, 28.7% and 8.6% of patients showed borderline and abnormal LFTs, respectively. There were 196 (16.9%) deaths and 298 (25.7%) HF readmissions during a median 12.4-month follow-up period. The abnormal LFTs group had a significantly higher risk of experiencing the composite outcome (adjusted hazard ratio: 1.51, 95% confidence interval: 1.08–2.12, p = 0.017), whereas the borderline LFTs group was not associated with higher risk of adverse events when referenced to the normal LFTs group. Among AHF patients, the combined elevation of ≥2 LFT panels at discharge was associated with long-term adverse outcomes.

scholarly journals The projected impacts of smart decline on urban runoff contamination levels

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Rui Zhu ◽  
Galen Newman
Keyword(s):  
Land Use ◽  
Green Infrastructure ◽  
Prediction Models ◽  
Stormwater Runoff ◽  
Baseline Scenario ◽  
Vacant Land ◽  
Smart Decline ◽  
Contamination Levels ◽  
Indirect Impacts

AbstractThere has been mounting interest about how the repurposing of vacant land (VL) through green infrastructure (the most common smart decline strategy) can reduce stormwater runoff and improve runoff quality, especially in legacy cities characterized by excessive industrial land uses and VL amounts. This research examines the long-term impacts of smart decline on both stormwater amounts and pollutants loads through integrating land use prediction models with green infrastructure performance models. Using the City of St. Louis, Missouri, USA as the study area, we simulate 2025 land use change using the Conversion of Land Use and its Effects (CLUE-S) and Markov Chain urban land use prediction models and assess these change’s probable impacts on urban contamination levels under different smart decline scenarios using the Long-Term Hydrologic Impact Assessment (L-THIA) performance model. The four different scenarios are: (1) a baseline scenario, (2) a 10% vacant land re-greening (VLRG) scenario, (3) a 20% VLRG scenario, and (4) a 30% VLRG scenario. The results of this study illustrate that smart decline VLRG strategies can have both direct and indirect impacts on urban stormwater runoff and their inherent contamination levels. Direct impacts on urban contamination include the reduction of stormwater runoff and non-point source (NPS) pollutants. In the 30% VLRG scenario, the annual runoff volume decreases by 11%, both physical, chemical, and bacterial pollutants are reduced by an average of 19%, compared to the baseline scenario. Indirect impacts include reduction of the possibility of illegal dumping on VL through mitigation and prevention of future vacancies.

scholarly journals Edaphic factors and plants influence denitrification in soils from a long-term arable experiment

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ian M. Clark ◽  
Qingling Fu ◽  
Maïder Abadie ◽  
Elizabeth R. Dixon ◽  
Aimeric Blaud ◽  
...  
Keyword(s):  
Gas Production ◽  
Soil Treatment ◽  
Soil Microbiome ◽  
Arable Soils ◽  
Experimental Conditions ◽  
Mineral N ◽  
Nitrate Availability ◽  
Denitrification Gene ◽  
Denitrification Genes

Abstract Factors influencing production of greenhouse gases nitrous oxide (N2O) and nitrogen (N2) in arable soils include high nitrate, moisture and plants; we investigate how differences in the soil microbiome due to antecedent soil treatment additionally influence denitrification. Microbial communities, denitrification gene abundance and gas production in soils from tilled arable plots with contrasting fertilizer inputs (no N, mineral N, FYM) and regenerated woodland in the long-term Broadbalk field experiment were investigated. Soil was transferred to pots, kept bare or planted with wheat and after 6 weeks, transferred to sealed chambers with or without K15NO3 fertilizer for 4 days; N2O and N2 were measured daily. Concentrations of N2O were higher when fertilizer was added, lower in the presence of plants, whilst N2 increased over time and with plants. Prior soil treatment but not exposure to N-fertiliser or plants during the experiment influenced denitrification gene (nirK, nirS, nosZI, nosZII) relative abundance. Under our experimental conditions, denitrification generated mostly N2; N2O was around 2% of total gaseous N2 + N2O. Prior long-term soil management influenced the soil microbiome and abundance of denitrification genes. The production of N2O was driven by nitrate availability and N2 generation increased in the presence of plants.

scholarly journals Lead, zinc, and chromium concentrations in acidic headwater streams in Sweden explained by chemical, climatic, and land-use variations

2012 ◽  
Vol 9 (11) ◽  
pp. 4323-4335 ◽  
Author(s):  
B. J. Huser ◽  
J. Fölster ◽  
S. J. Köhler
Keyword(s):  
Land Use ◽  
Predictive Power ◽  
Prediction Models ◽  
Headwater Streams ◽  
Data Series ◽  
Seasonal Differences ◽  
Metal Concentrations ◽  
Lead Zinc ◽  
Term Data

Abstract. Long-term data series (1996–2009) for eleven acidic headwater streams (< 10 km2) in Sweden were analyzed to determine factors controlling concentrations of trace metals. In-stream chemical data as well climatic, flow, and deposition chemistry data were used to develop models predicting concentrations of chromium (Cr), lead (Pb), and zinc (Zn). Data were initially analyzed using partial least squares to determine a set of variables that could predict metal concentrations across all sites. Organic matter (as absorbance) and iron related positively to Pb and Cr, while pH related negatively to Pb and Zn. Other variables such as conductivity, manganese, and temperature were important as well. Multiple linear regression was then used to determine minimally adequate prediction models which explained an average of 35% (Cr), 52% (Zn), and 72% (Pb) of metal variation across all sites. While models explained at least 50% of variation in the majority of sites for Pb (10) and Zn (8), only three sites met this criterion for Cr. Investigation of variation between site models for each metal revealed geographical (altitude), chemical (sulfate), and land-use (silvaculture) influences on predictive power of the models. Residual analysis revealed seasonal differences in the ability of the models to predict metal concentrations as well. Expected future changes in model variables were applied and results showed the potential for long-term increases (Pb) or decreases (Zn) for trace metal concentrations at these sites.

Air recirculation and ventilation in the coastal regions of the Black Sea

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Galina Surkova
Keyword(s):  
Black Sea ◽  
Eastern Coast ◽  
The Black Sea ◽  
Additional Risk Factor ◽  
Additional Risk ◽  
Sea Breezes ◽  
North Eastern ◽  
Favorable Conditions ◽  
Parameter Values

AbstractAn initial investigation of recirculation is carried out for the coast of the Black Sea. The local mesoscale circulations (land-sea breezes, mountain and valley winds) in coastal areas are shown to be an additional risk factor in creating favorable conditions for air stagnation and accumulation of air pollutants in the surface atmosphere layer. Two types of annual recirculation patterns are revealed for northern and north-eastern coast of the Black Sea. Long-term changes in recirculation are investigated. It is shown that the recirculation parameter values remained quasistable until the mid-1970s. Since 1976–1977, steady intensification of recirculation in both winter and summer is identified.

Verbalization and musical memory in string players

2017 ◽  
Vol 23 (2) ◽  
pp. 212-230
Author(s):  
Eric Timperman ◽  
Peter Miksza
Keyword(s):  
Recall Performance ◽  
Experimental Conditions ◽  
Immediate Recall ◽  
Short And Long Term ◽  
The Creation ◽  
24 Hour Recall ◽  
Associative Recall ◽  
Verbal Analysis ◽  
Musical Memory

The purpose of this study was to examine the effect of verbalization about a brief etude on collegiate string players’ short- and long-term recall of the etude in question. We examined competing hypotheses that suggest it is possible that verbalization (i.e., verbal analysis of musical features) (a) could aid in recall both by highlighting patterns and constraints that inform the music’s creation and by facilitating the creation of explicit performance cues that help to bridge gaps between associative recall chains or (b) may hinder recall by interfering with the creation of procedural and auditory memories necessary for musical performance. Participants ( N = 20) were assigned to experimental conditions in which they learned an unfamiliar etude either through repetition alone or through repetition followed by the completion of a verbalization worksheet provided by the experimenter. Recall was tested both immediately following initial practice and 24 hours later to examine the effect of verbalization on both short- and long-term retention. Findings indicated no differences between groups on immediate recall performance but significant differences at the 24-hour recall task with participants in the verbalization condition recalling more material. In addition, the patterns of errors found across groups indicated a strong primacy effect. Theoretical implications for the study of memory processes in musical contexts and practical implications regarding the preparation of memorized performance are discussed.

scholarly journals Breeding schemes in reindeer husbandry

Rangifer ◽  
2003 ◽  
Vol 23 (2) ◽  
pp. 45 ◽  
Author(s):  
Lars Rönnegård ◽  
J. A. Woolliams ◽  
Öje Danell
Keyword(s):  
Genetic Gain ◽  
Mass Selection ◽  
Effective Population ◽  
Selection Programme ◽  
Breeding Schemes ◽  
The Difference ◽  
Genetic Contributions ◽  
Parameter Values ◽  
Open Nucleus

The objective of the paper was to investigate annual genetic gain from selection (G), and the influence of selection on the inbreeding effective population size (Ne), for different possible breeding schemes within a reindeer herding district. The breeding schemes were analysed for different proportions of the population within a herding district included in the selection programme. Two different breeding schemes were analysed: an open nucleus scheme where males mix and mate between owner flocks, and a closed nucleus scheme where the males in non-selected owner flocks are culled to maximise G in the whole population. The theory of expected long-term genetic contributions was used and maternal effects were included in the analyses. Realistic parameter values were used for the population, modelled with 5000 reindeer in the population and a sex ratio of 14 adult females per male. The standard deviation of calf weights was 4.1 kg. Four different situations were explored and the results showed: 1. When the population was randomly culled, Ne equalled 2400. 2. When the whole population was selected on calf weights, Ne equalled 1700 and the total annual genetic gain (direct + maternal) in calf weight was 0.42 kg. 3. For the open nucleus scheme, G increased monotonically from 0 to 0.42 kg as the proportion of the population included in the selection programme increased from 0 to 1.0, and Ne decreased correspondingly from 2400 to 1700. 4. In the closed nucleus scheme the lowest value of Ne was 1300. For a given proportion of the population included in the selection programme, the difference in G between a closed nucleus scheme and an open one was up to 0.13 kg. We conclude that for mass selection based on calf weights in herding districts with 2000 animals or more, there are no risks of inbreeding effects caused by selection.

scholarly journals The Boron & De Weer Model of Intracellular pH Regulation

2020 ◽  
Author(s):  
Rossana Occhipinti ◽  
Soroush Safaei ◽  
Peter J. Hunter ◽  
Walter F. Boron
Keyword(s):  
Cell Membrane ◽  
Intracellular Ph ◽  
Ph Regulation ◽  
Quantitative Model ◽  
Historical Background ◽  
Acid Base ◽  
Experimental Conditions ◽  
Subsequent Work ◽  
Energy Dependent ◽  
Parameter Values

The classic Boron & De Weer (1976) paper provided the first evidence of active regulation of pH} in cells by an energy-dependent acid-base transporter. These authors also developed a quantitative model --- comprising passive fluxes of acid-base equivalents across the cell membrane, intracellular reactions, and an active transport mechanism in the cell membrane (modelled as a proton pump) --- to help interpret their measurements of intracellular pH under perturbations of both extracellular CO2/HCO3- and extracellular NH3/NH4+. This Physiome paper seeks to make that model, and the experimental conditions under which it was developed, available in a reproducible and well-documented form, along with a software implementation that makes the model easy to use and understand. We have also taken the opportunity to update some of the units used in the original paper, and to provide a few parameter values that were missing in the original paper. Finally, we provide an historical background to the Boron & De Weer (1976) proposal for active pH regulation and a commentary on subsequent work that has enriched our understanding of this most basic aspect of cellular physiology.

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