Determination of native (wood derived) formaldehyde by the desiccator method in particleboards generated during panel production

Holzforschung ◽  
2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Michael J. Birkeland ◽  
Linda Lorenz ◽  
James M. Wescott ◽  
Charles R. Frihart
Keyword(s):  
Hot Pressing ◽  
Urea Formaldehyde ◽  
Chromotropic Acid ◽  
Monitoring Methods ◽  
Emission Testing ◽  
Short And Long Term ◽  
The Common ◽  
Short Time

Abstract Hot-pressing wood, particularly in the production of wood composites, generates significant “native” (wood-based) formaldehyde (FA), even in the absence of adhesive. The level of native FA relates directly to the time and temperature of hot-pressing. This native FA dissipates in a relatively short time and is not part of the long-term FA emission issue commonly associated with hydrolyzing urea-formaldehyde bonds. This paper demonstrates that the common desiccator/chromotropic acid method is very specific for FA and is not influenced by other volatile compounds set free from wood during hot-pressing. Furthermore, it is shown that particleboard produces native FA at high levels even in the absence of adhesives or in the presence of one type of no-added formaldehyde (NAF) adhesive. Soy-based adhesives suppress native FA emission and provide low FA emission levels in both the short and long term. This study highlights an often overlooked aspect that should be considered for emission testing: standardizing the time and conditions employed immediately after pressing and prior to the onset of emissions testing. Addressing this issue in more detail would improve the reliability of correlation between data obtained by rapid process monitoring methods and emission measurements in large chambers.

scholarly journals EM-Based Monitoring and Probabilistic Analysis of Prestress Loss of Bonded Tendons in PSC Beams

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Zheheng Chen ◽  
Shanwen Zhang
Keyword(s):  
Probabilistic Analysis ◽  
Prestressed Concrete ◽  
Monitoring Methods ◽  
Prestress Loss ◽  
External Tendons ◽  
Material Environment ◽  
Key Factor ◽  
One Year

The prestress level is a key factor of prestressed concrete (PSC) beams, affecting their long-term serviceability and safety. Existing monitoring methods, however, are not effective in obtaining the force or stress of embedded tendons. This paper investigates the feasibility of elastomagnetic (EM) sensors, which have been used for external tendons, in monitoring the long-term prestress loss of bonded tendons. The influence of ambient temperature, water, eccentricity ratio, plastic duct, and cement grouts on the test results of EM sensors is experimentally examined. Based on the calibrated EM sensors, prestress loss of a group of PSC beams was monitored for one year. In order to further consider the high randomness in material, environment, and construction, probabilistic analysis of prestress loss is conducted. Finally, the variation range of prestress loss with a certain confidence level is obtained and is compared with the monitored data, which provides a basis for the determination of prestress level in the design of PSC beams.

scholarly journals Using Common Features to Investigate Common Growth Cycles for BRICS Countries

2018 ◽  
Vol 21 (4) ◽  
pp. 589-615
Author(s):  
Bruno Ricardo Delalibera ◽  
João Victor Issler ◽  
Roberto Castello Branco
Keyword(s):  
Emerging Market ◽  
Emerging Market Economies ◽  
Growth Cycles ◽  
Common Features ◽  
Developed Economies ◽  
Brics Countries ◽  
The Us ◽  
Short And Long Term ◽  
The Common

This paper examines the short and long-term co-movement of large  emerging market economies -- the BRICS countries -- by applying the  econometric techniques and the tests proposed in the common-feature literature. Despite their dissimilarities, given the rising trade linkages among the BRICS over the last 20 years one should expect their cycles to be  synchronized. Our empirical findings fully support this hypothesis. The evidence holds also for the co-movement between the BRICS and developed  economies, the US and the Eurozone, which may reflect the effects of  globalization.

scholarly journals Quantitative Determination of Vinpocetine in Dietary Supplements

2016 ◽  
Vol 11 (5) ◽  
pp. 1934578X1601100
Author(s):  
John M. T. French ◽  
Matthew D. King ◽  
Owen M. McDougal
Keyword(s):  
United States ◽  
Quantitative Determination ◽  
Dietary Supplements ◽  
Nootropic Drugs ◽  
Regulatory Policies ◽  
Short And Long Term ◽  
Pharmacologically Active ◽  
Active Substances

Current United States regulatory policies allow for the addition of pharmacologically active substances in dietary supplements if derived from a botanical source. The inclusion of certain nootropic drugs, such as vinpocetine, in dietary supplements has recently come under scrutiny due to the lack of defined dosage parameters and yet unproven short- and long-term benefits and risks to human health. This study quantified the concentration of vinpocetine in several commercially available dietary supplements and found that a highly variable range of 0.6–5.1 mg/serving was present across the tested products, with most products providing no specification of vinpocetine concentrations.

scholarly journals Longitudinal prediction of falls and near falls frequencies in Parkinson’s disease: a prospective cohort study

2020 ◽  
Author(s):  
Beata Lindholm ◽  
Christina Brogårdh ◽  
Per Odin ◽  
Peter Hagell
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Prospective Cohort ◽  
Prediction Models ◽  
Evidence Base ◽  
History Of ◽  
Short And Long Term ◽  
Near Falls ◽  
Short Time

Abstract Introduction and objective Several prediction models for falls/near falls in Parkinson’s disease (PD) have been proposed. However, longitudinal predictors of frequency of falls/near falls are poorly investigated. Therefore, we aimed to identify short- and long-term predictors of the number of falls/near falls in PD. Methods A prospective cohort of 58 persons with PD was assessed at baseline (mean age and PD duration, 65 and 3.2 years, respectively) and 3.5 years later. Potential predictors were history of falls and near falls, comfortable gait speed, freezing of gate, dyskinesia, retropulsion, tandem gait (TG), pain, and cognition (Mini-Mental State Exam, MMSE). After each assessment, the participants registered a number of falls/near falls during the following 6 months. Multivariate Poisson regression was used to identify short- and long-term predictors of a number of falls/near falls. Results Baseline median (q1–q3) motor (UPDRS) and MMSE scores were 10 (6.75–14) and 28.5 (27–29), respectively. History of falls was the only significant short-time predictor [incidence rate ratio (IRR), 15.17] for the number of falls/near falls during 6 months following baseline. Abnormal TG (IRR, 3.77) and lower MMSE scores (IRR, 1.17) were short-term predictors 3.5 years later. Abnormal TG (IRR, 7.79) and lower MMSE scores (IRR, 1.49) at baseline were long-term predictors of the number of falls/near falls 3.5 years later. Conclusion Abnormal TG and MMSE scores predict the number of falls/near falls in short and long term, and may be indicative of disease progression. Our observations provide important additions to the evidence base for clinical fall prediction in PD.

scholarly journals Frequency of osteoporosis in patients with peptic ulcer disease

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Amber Amin ◽  
Qaisar Farooq ◽  
Rizwan Jameel
Keyword(s):  
Peptic Ulcer ◽  
Peptic Ulcer Disease ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Ulcer Disease ◽  
Short And Long Term ◽  
The Common ◽  
The Mean ◽  
Age Range

BACKGROUND & OBJECTIVE: Peptic ulcer disease (PUD) is one of the common presentations in the medical as well as Gastroenterology clinics and it can end up in various short- and long-term complications among which osteoporosis is highly under rated. Therefore, the present study was designed to determine the frequency of osteoporosis in cases having PUD. METHODOLOGY: A cross-sectional study was conducted at the Department of Medicine during 1st January 2020 to 30th June 2020 in Sheikh Zayed Hospital, Lahore. The diagnosed cases of PUD on the basis of history and endoscopic findings with the age range of 20 to 60 years were included. Osteoporosis was labelled as yes, where a T-score of ≤ -2.5 on DEXA scan was noted. RESULTS: In this study, there were a total of 139 cases, out of which 75 (53.95%) were males and 64 (46.05%) females. The mean age of the participants was 48.11±9.43 years. Osteoporosis was observed in 14 (10.07%) out of 139 cases. Osteoporosis was seen in 05 (6.67%) males vs 09 (14.06%) females in their respective groups with p= 0.148. Osteoporosis was observed in 4 (5.80%) cases with a duration of PUD up to 2 years and 10 (14.28%) cases with duration more than this with p= 0.096 CONCLUSION: Osteoporosis is not uncommon in cases with Peptic ulcer disease, and there is no significant association with any of the confounders of this study.

scholarly journals COVID-19 in Chile: The usefulness of simple epidemic models in practice

Medwave ◽  
2021 ◽  
Vol 21 (01) ◽  
pp. e8119-e8119
Author(s):  
Mauricio Canals ◽  
Cristóbal Cuadrado ◽  
Andrea Canals
Keyword(s):  
Gompertz Model ◽  
Time Frame ◽  
Type Model ◽  
Local Behavior ◽  
Discrete Equations ◽  
The Monte Carlo Method ◽  
Great Utility ◽  
Short And Long Term ◽  
Short Time

Objectives The purpose of this article is to describe and develop the predictive value of three models during the COVID-19 epidemic in Chile, providing knowledge for decision-making in health. Methods We developed three models during the epidemic: a discrete model to predict the maximum burden on the health system in a short time frame—a basic SEIR (susceptible-exposed-infected-removed) model with discrete equations; a stochastic SEIR model with the Monte Carlo method; and a Gompertz-type model for metropolitan city of Santiago. Results The maximum potential burden model has been useful throughout the monitoring of the epidemic, providing an upper bound for the number of cases, intensive care unit occupancy, and deaths. Deterministic and stochastic SEIR models were very useful in predicting the rise of cases and the peak and onset of case decline; however, they lost utility in the current situation due to the asynchronous recruitment of cases in the regions and the persistence of a strong endemic. The Gompertz model had a better fit in the decline since it best captures the epidemic curve’s asymmetry in Santiago. Conclusions The models have shown great utility in monitoring the epidemic in Chile, with different objectives in different epidemic stages. They have complemented empirical indicators such as reported cases, fatality, deaths, and others, making it possible to predict situations of interest and visualization of the short and long-term local behavior of this pandemic.

scholarly journals The political economy of staying outside the Eurozone: Poland and Sweden compared

2015 ◽  
Vol 6 (3) ◽  
pp. 23
Author(s):  
Sławomir Czech
Keyword(s):  
Political Economy ◽  
Economic Policies ◽  
The Public ◽  
National Currencies ◽  
Recent Developments ◽  
Starting Conditions ◽  
The Common ◽  
Distribution Of Power ◽  
Short Time

This paper deals with the issue of political constraints put on economic policies that derive from the distribution of power in democratic societies. Poland and Sweden are both euro-outsiders that are obliged to adopt the euro, but recent developments within the Eurozone and related to the 2008+ crisis engendered widespread reluctance among the public to give up national currencies. Within a short time, the general support for the euro turned strongly negative, making it a grave challenge for politicians to pursue the adoption of the common currency. On this background, we reflect on the alleged correspondence between these two countries that would allow to follow similar policies toward euro introduction. We point to the idiosyncrasy of the Swedish case that makes it virtually impossible to emulate its policies by a country like Poland with very different long-term goals and starting conditions. By doing so, we highlight the context of policymaking that seems crucial to a successful art of political economy.

scholarly journals Efficiency of iodine deficiency prevention in Moscow in case of SouthWestern Administrative Okrug

2003 ◽  
Vol 49 (4) ◽  
pp. 33-36
Author(s):  
G. F. Okminyan ◽  
L. N. Samsonova ◽  
M. I. Pykov ◽  
T. G. Kurtseva ◽  
M. V. Veldanova ◽  
...  
Keyword(s):  
Iodine Deficiency ◽  
Prevention Programme ◽  
Monitoring Methods ◽  
The South ◽  
Initial Stage ◽  
Iodine Excretion ◽  
Short Time ◽  
The City

The paper deals with the remonitoring of goiter endemia and the evaluation of the efficiency of iodine deficiency prevention in the South- Western Administrative Okrug of Moscow. This paper us­es the data available in the literature and the authors ’ own data obtained in the examination of 514pupils aged 6-12 years. Rou­tine monitoring methods, such as thyroid palpation and ultra­sonography, determination of neonatal thyroid-stimulating hor­mone levels, ioduria median, and the incidence of decreased uri­nary iodine excretion), were used as indicators of goiter endemia and iodine provision. The iodine prevention programme imple­mented in Moscow since 1997 has been found to be rather ef­fective and to lower the strain of goiter endemia in the city; how­ever, it failed to eliminate it completely. The reasons reducing the efficiency of iodine prevention were identified. These included: the short time and difficulties of the initial stage of iodine pre­vention and/or the involvement of other strumogenic environ­mental factors in the formation of goiter endemia in Moscow.

Intermediate and Long-Term Radiological Consequences of an Uncontrolled Access of Saline Solution Into the Asse Mine

2011 ◽  
Author(s):  
Veronika Ustohalova ◽  
Christian Ku¨ppers
Keyword(s):  
Saline Solution ◽  
Anthropogenic Activities ◽  
Decay Chain ◽  
Radionuclide Migration ◽  
Chain Migration ◽  
Geological Conditions ◽  
Short And Long Term ◽  
Radionuclide Release ◽  
Short Time

The risk of radioactive contamination in the biosphere surrounding the Asse salt mine has been assessed to determine the possible radioactive exposure to humans if the mine collapses. Geological conditions and anthropogenic activities have made the mine instable and allow salt-saturated ground water to seep in. This uncontrolled brine inflow significantly increases the risk of the mine collapsing. If the mine collapses, the brine will be pressed into groundwater, where the radionuclides can migrate into the biosphere and cause radioactive exposure. The key issue discussed in this paper is estimating the short- and long-term radiation burden for humans under several possible scenarios of radionuclide release. Only a radioecological model able to quantify and estimate processes taking place can generate usable results. This work develops the radioecological model describing both radionuclide migration and the resulting radiological exposure along several exposition pathways. Development of the model took into account the sorption processes, solubility limits and special aspects of decay chain migration. The radiological exposure was estimated under non-equilibrated conditions for the case of short-time expositions. At the end of this paper, the model’s background, the results of the computations and a comparison of several scenarios will be presented.

Sign in / Sign up

Export Citation Format

Share Document