Effects of air pollutants on buildings and materials

1990 ◽  
Vol 97 ◽  
pp. 255-272 ◽  
Author(s):  
R. N. Butlin
Keyword(s):  
Economic Cost ◽  
Decay Rates ◽  
Damage Functions ◽  
General Applicability ◽  
Indoor Pollutants ◽  
Anthropogenic Pollutants ◽  
Synthetic Materials ◽  
Other Substances ◽  
Deposition Of Pollutants ◽  
Rates Of Decay

SynopsisThe main pollutants affecting materials are sulphur dioxide and sulphates, nitrogen oxides and nitrates, chlorides, carbon dioxide and ozone. In marine environments it is important to separate the effects of anthropogenic pollutants from marine sources of the same substances. The effects of paniculate matter, especially from diesel vehicle emissions is of increasing significance.In buildings containing books, historical artefacts or other works of art indoor pollutants may cause significant degradation. These pollutants may either be lower concentrations of pollutants originating outdoors or other substances generated from synthetic materials, paints, varnishes and display cases as well as from combustion for heating.The materials most sensitive to pollutants are calcareous building stones and ferrous metals. Manifestations of damage include losses of mass, changes in porosity, discoloration and embrittlement. In the case of stone it is difficult to (1) dissociate the effects of historical concentrations of pollution from current ones and (2) to establish background rates of erosion or decay in the absence of pollutants.Damage to materials in polluted atmospheres can be attributed to dry or wet deposition of pollutants, or dissolution in rainfall in the case of stone. Estimates of the contributions of the different mechanisms of decay have been made in programmes in the U.S.A. and the U.K.To obtain estimates of the economic cost of damage from acid deposition it is necessary to know how decay rates are related quantitatively to pollutants and meteorological parameters (damage functions), and the distribution of materials exposed in buildings and in geographical areas. There are few damage functions available and those in existence lack general applicability. There is. therefore, much importance attached to national and international exposure programmes that have been established to assess the responses of a range of materials to different environments. Such work is also of interest in predicting the potential effects of climatic changes on materials.Methodologies have been developed to enable estimates of economic costs of damage to be made. These are being refined with better data on rates of decay obtained from mathematical models and from exposure programmes. The concept of target loads for damage, originally devised for the natural environment, is being introduced to help assess the action needed to reduce degradation of sensitive materials and buildings.

scholarly journals Global Existence and Asymptotic Behavior of Solutions for Compressible Two-Fluid Euler–Maxwell Equation

2020 ◽  
Vol 2020 ◽  
pp. 1-27
Author(s):  
Ismahan Binshati ◽  
Harumi Hattori
Keyword(s):  
Asymptotic Behavior ◽  
Fourier Transform ◽  
Global Existence ◽  
Maxwell Equations ◽  
Decay Rates ◽  
Asymptotic Behavior Of Solutions ◽  
Two Fluids ◽  
The Fourier Transform ◽  
Rates Of Decay ◽  
Two Fluid

We study the global existence and asymptotic behavior of the solutions for two-fluid compressible isentropic Euler–Maxwell equations by the Fourier transform and energy method. We discuss the case when the pressure for two fluids is not identical, and we also add friction between the two fluids. In addition, we discuss the rates of decay of Lp−Lq norms for a linear system. Moreover, we use the result for Lp−Lq estimates to prove the decay rates for the nonlinear systems.

scholarly journals The impact of sea-level rise on organic matter decay rates in Chesapeake Bay brackish tidal marshes

2012 ◽  
Vol 9 (10) ◽  
pp. 14689-14708 ◽  
Author(s):  
M. L. Kirwan ◽  
J. A. Langley ◽  
G. R. Guntenspergen ◽  
J. P. Megonigal
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Sea Level Rise ◽  
Chesapeake Bay ◽  
Sea Level ◽  
Decay Rates ◽  
Tidal Marshes ◽  
Study Sites ◽  
Rates Of Decay ◽  
The Impact

Abstract. The balance between organic matter production and decay determines how fast coastal wetlands accumulate soil organic matter. Despite the importance of soil organic matter accumulation rates in influencing marsh elevation and resistance to sea-level rise, relatively little is known about how decomposition rates will respond to sea-level rise. Here, we estimate the sensitivity of decomposition to flooding by measuring rates of decay in 87 bags filled with milled sedge peat, including soil organic matter, roots and rhizomes. Experiments were located in field-based mesocosms along 3 mesohaline tributaries of the Chesapeake Bay. Mesocosm elevations were manipulated to influence the duration of tidal inundation. Although we found no significant influence of inundation on decay rate when bags from all study sites were analyzed together, decay rates at two of the sites increased with greater flooding. These findings suggest that flooding may enhance organic matter decay rates even in water-logged soils, but that the overall influence of flooding is minor. Our experiments suggest that sea-level rise will not accelerate rates of peat accumulation by slowing the rate of soil organic matter decay. Consequently, marshes will require enhanced organic matter productivity or mineral sediment deposition to survive accelerating sea-level rise.

Article

1998 ◽  
Vol 76 (11) ◽  
pp. 1753-1765
Author(s):  
Christopher B Kennedy ◽  
Bruce J Balcom ◽  
Igor V Mastikhin
Keyword(s):  
Spin Relaxation ◽  
Spin Echo ◽  
Single Point ◽  
Relaxation Times ◽  
Three Dimensional ◽  
Polymeric Materials ◽  
Solid Core ◽  
General Applicability ◽  
Conventional Mri ◽  
Synthetic Materials

A new MRI method, recently employed in porous-media studies, is introduced for the imaging of rigid polymeric materials. The method, Single-Point Ramped Imaging with T1 Enhancement (SPRITE), is designed to spatially encode short lifetime, T2*, signals characteristic of rigid materials. We investigate the advantages of the SPRITE technique over conventional imaging methods by comparing a 2D SPRITE image of four common polymers to a 2D spin-echo image of the same substances. We demonstrate the general applicability of SPRITE by imaging two commercial products, a stop-valve made of chlorinated polyvinyl chloride and a solid-core, multilayer golf ball, both containing synthetic materials with effective 1H spin-spin relaxation times, T2*, well under 300 µs. Three-dimensional images of millimeter resolution reveal internal physical differentiation and chemical inhomogeneities that cannot be observed using conventional MRI methods. We also consider the incorporation of active spoiler gradients in SPRITE for visualization of samples with long spin-spin relaxation times, T2.Key words: MRI, NMR, SPI, SPRITE, polymers, imaging.

scholarly journals NONLINEAR WELL-POSEDNESS AND RATES OF DECAY IN THERMOELASTICITY WITH SECOND SOUND

2008 ◽  
Vol 05 (01) ◽  
pp. 25-43 ◽  
Author(s):  
REINHARD RACKE ◽  
YA-GUANG WANG
Keyword(s):  
Hyperbolic Systems ◽  
Decay Rates ◽  
Energy Estimates ◽  
Well Posedness ◽  
Time Behavior ◽  
Second Sound ◽  
Small Solution ◽  
Nonlinear Thermoelasticity ◽  
The Cauchy Problem ◽  
Rates Of Decay

The Cauchy problem in nonlinear thermoelasticity with second sound in one space dimension is considered. Due to Cattaneo's law, replacing Fourier's law for heat conduction, the system is hyperbolic. The local well-posedness as a strictly hyperbolic system is investigated first, and then the relation between energy estimates for non-symmetric hyperbolic systems and well-posedness are discussed. For the global small solution, the long time behavior is described and the decay rates of the L2-norm are obtained.

scholarly journals The influence of rare birds on observer effort and subsequent rarity discovery in the American birdwatching community

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10713
Author(s):  
Jesse A. Laney ◽  
Tyler A. Hallman ◽  
Jenna R. Curtis ◽  
W. Douglas Robinson
Keyword(s):  
Feedback Loop ◽  
The United States ◽  
Decay Rates ◽  
Supporting Evidence ◽  
Social Feedback ◽  
Species Identity ◽  
Site Specific ◽  
Factors Associated ◽  
Rates Of Decay ◽  
Untapped Resource

Birdwatching is a rapidly growing pastime, increasingly involving the pursuit of rare birds as birders build lists of species they encounter. We expected reports of rare bird discoveries to quickly draw birders to locations, and that the increased attention at those locations would decay over time. We hypothesized that magnitude of draw and rates of decay would vary depending on characteristics of the species and the geographic locations where rarities were discovered. Discoveries of additional rarities might affect both the draw and decay, so we also quantified empirical evidence for the Patagonia Picnic Table Effect (PPTE), a social feedback loop where rarity discoveries are presumed to lead to additional rarity discoveries because of the elevated levels of birder activity once an initial rarity is reported. Although commonly invoked, supporting evidence for the PPTE hypothesis is anecdotal. We used 10 years of eBird data (2008–2017) in the United States to (1) understand birding activity when rarities were reported and the factors associated with draw and decay, and (2) assess the frequency at which initial rarity discoveries lead to reports of additional rarities. Across 273 rarity events, birder effort, as indexed by numbers of eBird checklists, increased above the pre-event baseline level, with the magnitude of draw varying geographically. We found no indication that draw was influenced by species identity or rarity-level, but latitude and distance to small airport proved important in drawing additional eBirders to rare bird discoveries. Mean draw of rarities and mean number of checklists from the same locations prior to each rarity discovery grew through the ten years, suggesting an increased influence of eBird on birder behavior in general. Decay rates in birder effort were more gradual in rare bird events with longer durations. Effort declined below baseline-levels after rarities went undetected, suggesting, “location-fatigue” following rarity events. Results did not support the PPTE hypothesis. Controlling for site-specific circumstances, birders had no better chance of finding additional rarities during events than at times outside events. Our results emphasize that eBird checklist quantity at rarity events follows a predictable but variable pattern of draw and decay influenced by location and time since rarity discovery; that birders have statistically similar chances of finding rarities during normal “baseline” birding activities as they do when known rarities are present; and that eBird represents a largely untapped resource for studying factors that influence levels of birding activity.

scholarly journals The impact of sea-level rise on organic matter decay rates in Chesapeake Bay brackish tidal marshes

2013 ◽  
Vol 10 (3) ◽  
pp. 1869-1876 ◽  
Author(s):  
M. L. Kirwan ◽  
J. A. Langley ◽  
G. R. Guntenspergen ◽  
J. P. Megonigal
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Sea Level Rise ◽  
Chesapeake Bay ◽  
Sea Level ◽  
Decay Rates ◽  
Tidal Marshes ◽  
Study Sites ◽  
Rates Of Decay ◽  
The Impact

Abstract. The balance between organic matter production and decay determines how fast coastal wetlands accumulate soil organic matter. Despite the importance of soil organic matter accumulation rates in influencing marsh elevation and resistance to sea-level rise, relatively little is known about how decomposition rates will respond to sea-level rise. Here, we estimate the sensitivity of decomposition to flooding by measuring rates of decay in 87 bags filled with milled sedge peat, including soil organic matter, roots and rhizomes. Experiments were located in field-based mesocosms along 3 mesohaline tributaries of the Chesapeake Bay. Mesocosm elevations were manipulated to influence the duration of tidal inundation. Although we found no significant influence of inundation on decay rate when bags from all study sites were analyzed together, decay rates at two of the sites increased with greater flooding. These findings suggest that flooding may enhance organic matter decay rates even in water-logged soils, but that the overall influence of flooding is minor. Our experiments suggest that sea-level rise will not accelerate rates of peat accumulation by slowing the rate of soil organic matter decay. Consequently, marshes will require enhanced organic matter productivity or mineral sediment deposition to survive accelerating sea-level rise.

scholarly journals Damage functions for climate-related hazards: unification and uncertainty analysis

2016 ◽  
Vol 16 (5) ◽  
pp. 1189-1203 ◽  
Author(s):  
Boris F. Prahl ◽  
Diego Rybski ◽  
Markus Boettle ◽  
Jürgen P. Kropp
Keyword(s):  
Climate Change Impacts ◽  
Storm Damage ◽  
Unified Approach ◽  
Damage Functions ◽  
General Applicability ◽  
General Role ◽  
Uncertainty Sources ◽  
Scale Levels ◽  
Consistent Treatment ◽  
Development And Validation

Abstract. Most climate change impacts manifest in the form of natural hazards. Damage assessment typically relies on damage functions that translate the magnitude of extreme events to a quantifiable damage. In practice, the availability of damage functions is limited due to a lack of data sources and a lack of understanding of damage processes. The study of the characteristics of damage functions for different hazards could strengthen the theoretical foundation of damage functions and support their development and validation. Accordingly, we investigate analogies of damage functions for coastal flooding and for wind storms and identify a unified approach. This approach has general applicability for granular portfolios and may also be applied, for example, to heat-related mortality. Moreover, the unification enables the transfer of methodology between hazards and a consistent treatment of uncertainty. This is demonstrated by a sensitivity analysis on the basis of two simple case studies (for coastal flood and storm damage). The analysis reveals the relevance of the various uncertainty sources at varying hazard magnitude and on both the microscale and the macroscale level. Main findings are the dominance of uncertainty from the hazard magnitude and the persistent behaviour of intrinsic uncertainties on both scale levels. Our results shed light on the general role of uncertainties and provide useful insight for the application of the unified approach.

TOXICITY AND METABOLIC EFFECTS OF INTRAVENOUSLY ADMINISTERED 3-NITROPROPANOL IN CATTLE

1981 ◽  
Vol 61 (3) ◽  
pp. 639-647 ◽  
Author(s):  
W. MAJAK ◽  
R. E. McDIARMID ◽  
T. UDENBERG ◽  
H. DOUWES
Keyword(s):  
Decay Rate ◽  
Gradual Increase ◽  
Decay Rates ◽  
Metabolic Effects ◽  
Bovine Blood ◽  
Respiration Rates ◽  
Plasma Nitrite ◽  
Rates Of Decay

In vitro and in vivo metabolic studies were conducted with bovine blood to determine decay rates for 3-nitropropanol (NPOH), a toxic forage constituent occurring in many Astragalus species. Methemoglobin (metHb) and plasma nitrite [Formula: see text] levels were concomitantly determined and early signs of poisoning were recorded. Subtle increases in heart and respiration rates, development of a placid, stupefied state, frothy salivation and incoordination characterized early stages of intoxication. Animals with low decay rates for NPOH showed a gradual increase in the metHb and [Formula: see text]. When the decay rate was high, a rapid increase in netHb and [Formula: see text] was observed. Acutely poisoned animals showed the highest levels of metHb and [Formula: see text] but intermediate rates of decay for NPOH. When NPOH was incubated with bovine blood in vitro, [Formula: see text] was not detected and metHb was not significantly altered, indicating that NPOH is not metabolized in bovine blood. A new method is described for determining NPOH in bovine blood.

Destruction of Actin Filaments by Osmium Tetroxide

1977 ◽  
Vol 35 ◽  
pp. 466-467
Author(s):  
P. Maupin-Szamier ◽  
T. D. Pollard
Keyword(s):  
Actin Filaments ◽  
Time Course ◽  
Osmium Tetroxide ◽  
Rabbit Muscle ◽  
Muscle Actin ◽  
Sodium Phosphate Buffer ◽  
Transmission Electron ◽  
The Difference ◽  
Rates Of Decay ◽  
Short Time

We have studied the destruction of rabbit muscle actin filaments by osmium tetroxide (OSO4) to develop methods which will preserve the structure of actin filaments during preparation for transmission electron microscopy.Negatively stained F-actin, which appears as smooth, gently curved filaments in control samples (Fig. 1a), acquire an angular, distorted profile and break into progressively shorter pieces after exposure to OSO4 (Fig. 1b,c). We followed the time course of the reaction with viscometry since it is a simple, quantitative method to assess filament integrity. The difference in rates of decay in viscosity of polymerized actin solutions after the addition of four concentrations of OSO4 is illustrated in Fig. 2. Viscometry indicated that the rate of actin filament destruction is also dependent upon temperature, buffer type, buffer concentration, and pH, and requires the continued presence of OSO4. The conditions most favorable to filament preservation are fixation in a low concentration of OSO4 for a short time at 0°C in 100mM sodium phosphate buffer, pH 6.0.

Structural preservation and absolute contrast of catalase crystal sections prepared with tannic acid

1983 ◽  
Vol 41 ◽  
pp. 448-449
Author(s):  
C.W. Akey ◽  
M. Szalay ◽  
S.J. Edelstein
Keyword(s):  
Tannic Acid ◽  
Beef Heart ◽  
X Rays ◽  
Screw Axis ◽  
General Applicability ◽  
Thin Sections ◽  
Beef Liver ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Structural Preservation

Three methods of obtaining 20 Å resolution in sectioned protein crystals have recently been described. They include tannic acid fixation, low temperature embedding and grid sectioning. To be useful for 3-dimensional reconstruction thin sections must possess suitable resolution, structural fidelity and a known contrast. Tannic acid fixation appears to satisfy the above criteria based on studies of crystals of Pseudomonas cytochrome oxidase, orthorhombic beef liver catalase and beef heart F1-ATPase. In order to develop methods with general applicability, we have concentrated our efforts on a trigonal modification of catalase which routinely demonstrated a resolution of 40 Å. The catalase system is particularly useful since a comparison with the structure recently solved with x-rays will permit evaluation of the accuracy of 3-D reconstructions of sectioned crystals.Initially, we re-evaluated the packing of trigonal catalase crystals studied by Longley. Images of the (001) plane are of particular interest since they give a projection down the 31-screw axis in space group P3121. Images obtained by the method of Longley or by tannic acid fixation are negatively contrasted since control experiments with orthorhombic catalase plates yield negatively stained specimens with conditions used for the larger trigonal crystals.

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