Distribution by Scientific Domains
Distribution within Earth and Environmental Science

Kinds of Moisture

  • feed moisture
  • fuel moisture
  • high moisture
  • increasing soil moisture
  • soil moisture

  • Terms modified by Moisture

  • moisture absorption
  • moisture adsorption
  • moisture availability
  • moisture budget
  • moisture condition
  • moisture content
  • moisture content decreased
  • moisture convergence
  • moisture data
  • moisture deficit
  • moisture distribution
  • moisture exchanger
  • moisture flux
  • moisture gradient
  • moisture index
  • moisture level
  • moisture loss
  • moisture pattern
  • moisture perturbation
  • moisture profile
  • moisture regime
  • moisture sorption
  • moisture sorption isotherm
  • moisture source
  • moisture status
  • moisture storage
  • moisture stress
  • moisture transport
  • moisture uptake
  • moisture variability

  • Selected Abstracts


    ABSTRACTS Textural characteristics of 10 Cheddar cheeses with a range of moisture contents and pH values were investigated by sensory and instrumental methods, over a 9-month maturing period. A trained panel of nine assessors described the sensory texture characteristics of the cheeses using 11 texture parameters. Instrumental parameters were derived using texture profile analysis. Relationships between sensory, instrumental, compositional and maturation properties of the cheeses were determined with the aid of principal component analysis and multiple linear regression. Nine sensory parameters significantly correlated with instrumental parameters, e.g., sensory rubbery correlated with instrumental firmness (R = 0.696, P < 0.001), chewiness (R = 0.679, P < 0.001), fracture stress (R = 0.669, P < 0.001) and springiness (R = 0.643, P < 0.001). Sensory firmness corresponded closely with instrumental firmness (R = 0.539, P < 0.001) and fracture stress (R = 0.518, P < 0.001). Sensory and instrumental texture parameters were significantly affected by changes in moisture content, pH and maturation. [source]

    The Effects of Moisture in Low-Voltage Organic Field-Effect Transistors Gated with a Hydrous Solid Electrolyte

    Nikolai Kaihovirta
    Abstract The concept of using ion conducting membranes (50,150 ,m thick) for gating low-voltage (1 V) organic field-effect transistors (OFETs) is attractive due to its low-cost and large-area manufacturing capabilities. Furthermore, the membranes can be tailor-made to be ion conducting in any desired way or pattern. For the electrolyte gated OFETs in general, the key to low-voltage operation is the electrolyte "insulator" (the membrane) that provides a high effective capacitance due to ionic polarization within the insulator. Hydrous ion conducting membranes are easy to process and readily available. However, the role of the water in combination with the polymeric semiconductor has not yet been fully clarified. In this work electrical and optical techniques are utilized to carefully monitor the electrolyte/semiconductor interface in an ion conducting membrane based OFET. The main findings are that 1) moisture plays a major part in the transistor operation and careful control of both the ambient atmosphere and the potential differences between the electrodes are required for stable and consistent device behavior, 2) the obtained maximum effective capacitance (5 ,F cm,2) of the membrane suggests that the electric double layer is distributed over a broad region within the polyelectrolyte, and 3) electromodulation spectroscopy combined with current,voltage characteristics provide a method to determine the threshold gate voltage from an electrostatic field-effect doping to a region of (irreversible) electrochemical perturbation of the polymeric semiconductor. [source]

    Direct Spectroscopic Evidence for a Photodoping Mechanism in Polythiophene and Poly(bithiophene- alt -thienothiophene) Organic Semiconductor Thin Films Involving Oxygen and Sorbed Moisture

    ADVANCED MATERIALS, Issue 46 2009
    Jing-Mei Zhuo
    Direct infrared spectroscopic evidence has been obtained for photodoping of high mobility regioregular poly(3-alkylthiophene) and poly[2,5-bis(3-alkyllthiophen-2-yl) thieno (3,2-b)thiophene] with the attendant formation of hydroxide counter-ions. This reveals the central role of dissolved water, explains the key features of degradation of the electrical characteristics of organic semiconductors in the ambient (see figure), and points to possible strategies to further improve their stability. [source]

    Stacked partial least squares regression analysis for spectral calibration and prediction

    Wangdong Ni
    Abstract Two novel algorithms which employ the idea of stacked generalization or stacked regression, stacked partial least squares (SPLS) and stacked moving-window partial least squares (SMWPLS) are reported in the present paper. The new algorithms establish parallel, conventional PLS models based on all intervals of a set of spectra to take advantage of the information from the whole spectrum by incorporating parallel models in a way to emphasize intervals highly related to the target property. It is theoretically and experimentally illustrated that the predictive ability of these two stacked methods combining all subsets or intervals of the whole spectrum is never poorer than that of a PLS model based only on the best interval. These two stacking algorithms generate more parsimonious regression models with better predictive power than conventional PLS, and perform best when the spectral information is neither isolated to a single, small region, nor spread uniformly over the response. A simulation data set is employed in this work not only to demonstrate this improvement, but also to demonstrate that stacked regressions have the potential capability of predicting property information from an outlier spectrum in the prediction set. Moisture, oil, protein and starch in Cargill corn samples have been successfully predicted by these new algorithms, as well as hydroxyl number for different instruments of terpolymer samples including and excluding an outlier spectrum. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    N. HUMA
    ABSTRACT The effect of packaging materials on the physicochemical and rheological characteristics of iron-fortified wholemeal flour (WMF) during storage was determined. WMF was fortified with three fortificants, namely ferrous sulfate (30 ppm), ferrous sulfate + ethylenediamine tetraacetic acid (EDTA) (20 + 20 ppm) and elemental iron (60 ppm). Each flour was also fortified with 1.5 ppm folic acid. Moisture, flour acidity and peroxide value increased during storage, while protein and fat contents decreased. Highest conversion of Fe2+ into Fe3+was observed in flour fortified with ferrous sulfate (2.72%), followed by that fortified with ferrous sulfate + EDTA (1.49%) and elemental iron (1.06%). Water absorption and dough viscosity of iron-fortified flours increased during storage. The flour containing ferrous sulfate was most acceptable regarding sensory characteristics, followed by samples containing ferrous sulfate + EDTA. Fortified flours were more stable during storage than unfortified. Addition of EDTA increased the stability of flours and fortificants. The fortified flours stored in polypropylene bags proved more stable than those stored in the tin boxes. PRACTICAL APPLICATIONS The main role of packaging is to protect the product during handling, distribution and storage against environmental and mechanical hazards. The success of a fortification program depends on the stability of micronutrients and food to which these are added. Chemical changes during storage badly affect chapatti making and sensory properties. Exposure of the fortificant to any factor including heat, moisture, air or light, and acid or alkaline environments during processing, packaging, distribution, or storage affects its stability. Flour containing elemental iron and ferrous sulfate with EDTA remained stable up to 42 days. The unfortified flour and flour containing ferrous sulfate remained stable for 21 days in tin boxes and 28 days in the polypropylene bags. Wheat flour milling industry would be benefited from this research if government is keen to launch iron fortification program in the country to curb iron deficiency anemia among population. [source]

    Effects of Water-Glycerol and Water-Sorbitol Interactions on the Physical Properties of Konjac Glucomannan Films

    Lai Hoong Cheng
    ABSTRACT Konjac glucomannan (KGM)-edible films were prepared with different amounts of glycerol or sorbitol as a plasticizer. Films were characterized by moisture sorption isotherm, and following conditioning at different relative humidities, by differential scanning calorimetry and tensile tests. Moisture and polyols (sorbitol and glycerol) were found to plasticize KGM-based films with respect to their tensile properties. However, thermal properties and water sorption capacity (WSC) of polyolplasticized KGM films were found to vary with water activity (aw), namely at low aw (< 0.6), WSC and melting enthalpy were decreased with increasing in polyol content and the opposite was true at higher aw (>0.6). This was attributed to extensive interactions between plasticizer and KGM that reduced the available active site (-OH groups) for water adsorption. The presence of polyols at low aw appeared to suppress crystalline structures due probably to restricted molecular mobility. These effects were diminished when the moisture content was >20%. [source]

    Correlation between Moisture and Water Activity of Honeys Harvested in Different Years

    M.M. Cavia
    ABSTRACT: For the 1st time, a relationship has been investigated between moisture percentage (M) and water activity (aW) in honeys from 2 different harvesting years and 2 different climatic areas. Moisture was determined by measuring refractive index at 20°C, according to official methods. At the same time, aW of the same samples was assessed at exactly 20°C. Influence on the relationship of the crop's year, aging, and induced fine granulation was evaluated. The results show that, independent of all factors studied, an excellent and statistically significant linear correlation between both parameters [aW = 0.3114 + (0.0170 × M)] was found in all samples with a regression coefficient of 0.8809. The measurement of aW of honey is interesting but time-consuming. This study concludes that this parameter can be easily calculated from the moisture percentage, thus avoiding the use of expensive and slow equipment for aW measurement. [source]

    Storage Water Activity Effect on Oxidation and Sensory Properties of High-Oleic Peanuts

    G.L. Baker
    Peanuts were stored under different water activities and maintained using saturated salt solutions, for 14 wks. Peroxide values, percent moisture, and sensory attributes were determined at 2 wk intervals. Peroxide values increased over time for all treatments. The highest oxidation values were observed in the peanuts held under 0.67 water activity, followed by 0.12, 0.52, 0.44 and 0.33, respectively. Moisture increased over time for all samples and correlated with the water activity of storage. Roast peanut flavor decreased with time and the decrease was greater at higher aw of storage. [source]

    Texture and Chemical Characteristics of Soy Protein Meat Analog Extruded at High Moisture

    S. Lin
    ABSTRACT: The relationships among extruder responses, texture, and protein solubility of soy protein meat analogs were studied. Soy protein isolate and wheat starch at 9:1 ratio were extruded at 60%, 65%, and 70% moisture contents and 137.8, 148.9, and 160°C cooking temperatures. The results showed that moisture content was a more important factor on the overall product texture than cooking temperature. Lower moisture content resulted in higher die pressure, harder texture, and lower total protein solubility. At a fixed moisture content, a higher cooking temperature resulted in a softer and less chewy product but only slightly changed the protein solubility. According to partial least square regression, the data from Texture Profile Analysis, protein solubility, and extruder responses correlated well and could be used to predict each other. [source]


    ABSTRACT The objectives of this research were to estimate the ability of chemical analysis, cooking properties, sensory evaluation and instrumental texture assays as descriptive quality parameters, and to evaluate the association between sensory and instrumental measurements on commercial pasta samples. Five commercial samples, Com1 to Com5, were analyzed. Moisture, protein and ash contents were determined from raw materials, while cooking loss, water absorption and leached amylose were measured in cooked samples. Color parameters (L*, a* and b*) were determined spectrophotometrically and color scores were calculated from raw and cooked samples. Three instrumental texture assays by a texture analyzer (TA-xT2i) and seven sensory parameters were evaluated. Chemical analysis, cooking properties, sensory evaluation and texture measurement were found to be sensitive quality parameters. From the analysis of the results, Com1 showed the best quality. A significant relationship between the sensory and instrumental measurements according to Pearson correlation and the principal component analysis was also observed. PRACTICAL APPLICATIONS In this work, the quality of different commercial pastas was assessed by means of chemical analysis, cooking properties, sensory evaluation and instrumental texture. The goal of this study was to identify the most important determinations related to pasta quality, and it allowed the establishment of the relationship between the sensory properties and texture measurements. [source]

    Influence of Moisture on Ultra-High-Temperature Tensile Creep Behavior of in Situ Single-Crystal Oxide Ceramic Alumina/Yttrium Aluminum Garnet Eutectic Composite

    Yoshihisa Harada
    Tensile creep tests were conducted for an in situ single-crystal alumina/yttrium aluminum garnet (Al2O3/Y3Al5O12 (YAG)) binary system eutectic composite at temperatures between 1773 and 1873 K in air and in a moist environment having a water-vapor pressure range of 0.06,0.6 MPa, under a constant tensile stress range of 100,160 MPa. The Al2O3/YAG eutectic composite exhibited a stress exponent of 8,13, indicative of tensile creep behavior characterized by a dislocation back-stress mechanism. Water-vapor pressures ,0.4 MPa led to a significant acceleration of creep rates as a result of enhanced dislocation mobility in the Al2O3 and YAG phases. [source]

    Soil state and surface hydrology diagnosis based on MOSES in the Met Office Nimrod nowcasting system

    R. N. B. Smith
    Abstract A system has been developed and made operational at the Met Office for the real-time diagnosis of soil state and surface hydrology. It is based on the Met Office Surface Exchanges Scheme (MOSES) modified to take account of unresolved soil and topographic heterogeneity when calculating surface runoff by incorporating a Probability Distributed Moisture (PDM) scheme developed by the Centre for Ecology and Hydrology. The implementation of MOSES-PDM in the Met Office's Nimrod nowcasting system is described. High resolution soil characteristics and land cover data, together with Nimrod's analyses of precipitation amount and type, cloud cover and near-surface atmospheric variables are used to drive MOSES-PDM. Hourly values of snowmelt, runoff, net surface radiation, evaporation, potential evaporation, soil temperature, soil moisture and soil moisture deficit are calculated on a 5 km grid. Copyright © 2006 Royal Meteorological Society. [source]

    Effects of bryophytes and lichens on seedling emergence of alvar plants: evidence from greenhouse experiments

    OIKOS, Issue 3 2000
    Manuela Zamfir
    Emergence of seedlings of four alvar grassland species (Arenaria serpyllifolia, Festuca ovina, Filipendula vulgaris and Veronica spicata) in bryophyte and lichen carpets was analysed in a series of greenhouse experiments. The aspects investigated were: the influence of thickness of moss mats, both in dry and moist conditions, the effects of thick Cladonia spp. clumps, and of living vs dead moss shoots and lichen podetia. Overall, Festuca seedlings emerged best whereas the small-seeded species, Arenaria and Veronica , had the lowest emergence. Moisture had a significant effect only on the emergence of Festuca seedlings, which emerged better in the dry treatment than in the moist. A thick moss cover negatively affected seedling emergence of Arenaria and Veronica but did not affect the emergence of Festuca. Filipendula showed lower seedling emergence in both thick and thin moss than on bare soil only in the dry treatment, whereas in the moist treatment emergence did not differ among the three substrates. Arenaria seedlings emerged less in thick and thin moss than on bare soil in the dry treatment, whereas in the moist treatment emergence in the thin moss was not different from bare soil. Thus, in relatively dry environments even a thin moss cover may inhibit rather than facilitate seedling emergence. The lichen clumps inhibited only the emergence of the forbs. Both living moss shoots and lichen podetia inhibited emergence of Veronica seedlings but did not affect Festuca. In contrast, emergence in the presence of dead mosses and lichens did not differ from emergence in their absence for both species. Hence, inhibition of seedling emergence by bryophytes and lichens of at least some vascular plant species may be mediated by some biotic factor. However, the effect of differences in substrate properties on germination cannot be excluded [source]

    Moisture and Creep Effects on Paper, Board and Containers

    David Shires
    No abstract is available for this article. [source]

    Responses of Nondormant Black Willow (Salix nigra) Cuttings to Preplanting Soaking and Soil Moisture

    S. R. Pezeshki
    Abstract The use of willow cuttings for streambank stabilization is a common practice in riparian ecosystems throughout the United States. Many environmental factors govern the outcome of such planting. However, other factors such as preplanting treatments, planting methods, and physiological status of cuttings (dormant vs. actively growing) may also be crucial in determining the survival of willow cuttings. Actively growing (nondormant) Black willow (Salix nigra) cuttings, 30 cm in length and 1 cm in diameter at the base, were subjected to three soaking treatments (0, 7, and 15 days) prior to planting. Following the initial treatment, cuttings were grown in a greenhouse in pots under three soil moisture regimes (well-watered but not flooded, permanently flooded, and intermittently flooded). Plant gas exchange, growth, biomass, and survival were measured. Results demonstrated that soaking for 7 days was beneficial to early development of cuttings in the well-watered (control) soil moisture regime, enhancing percent bud flush and survival significantly. However, 15 days of soaking proved to be detrimental to survival of cuttings irrespective of soil moisture regimes. Results also demonstrated that the beneficial effects of 7-day soaking were limited to the well-watered soil moisture regime but not to the flooded or intermittently flooded regimes. Soaking nondormant cuttings may be worthwhile if the planting site is likely to present ample soil moisture but nonflooded conditions to the transplanted cuttings. [source]

    Nutritional chemistry of foods eaten by gorillas in Bwindi Impenetrable National Park, Uganda

    Jessica M. Rothman
    Abstract Foods eaten by gorillas (Gorilla beringei) in Bwindi Impenetrable National Park (BINP), Uganda, were analyzed for their nutrient content. The goal of the study was to assess the amounts of fiber, protein, and sugars in the foods eaten by the Bwindi gorillas, and to determine whether condensed tannins and cyanide are present in these foods. A total of 127 food plant parts representing 84 plant species eaten by two groups of Bwindi gorillas were collected, processed, and analyzed for their chemical contents. The Bwindi gorilla ate foods that contain 2,28% crude protein (CP), 21,88% neutral detergent fiber (NDF), 14,60% acid detergent fiber (ADF), 2,42% acid detergent lignin (ADL), and ,1,50% water-soluble carbohydrates (WSC) on a dry matter (DM) basis. Moisture in these foods ranged from 7% to 96%. Approximately 35% of the foods analyzed contained condensed tannins, and two foods contained cyanogenic glycosides. This is the first detailed report regarding the nutritional chemistry of gorilla foods in Bwindi, many of which are also eaten by other primates. This unique data set adds to our knowledge about the nutritional composition of foods eaten by gorillas across habitats, is useful for understanding aspects of feeding behavior, and provides valuable comparative data for optimizing the diets of gorillas ex situ. Am. J. Primatol. 68:1,17, 2006. © 2005 Wiley-Liss, Inc. [source]

    Moisture,convection feedback in the tropics

    W. W. Grabowski
    Abstract This paper discusses the large-scale moisture,convection feedback in the tropics, where spatial fluctuations of deep convection cause perturbations of free-tropospheric moisture which, in turn, affect the spatial distribution of deep convection. A simple heuristic argument using the timescale of free-tropospheric humidity change explains why moisture,convection feedback is particularly relevant for tropical intraseasonal oscillations. The large-scale dynamical context for moisture,convection feedback is investigated in idealized rotating constant-sea-surface-temperature (,tropics everywhere') aquaplanet using cloud-resolving convection parametrization (CRCP; super-parametrization) and a traditional convective parametrization (the Emanuel scheme). The large-scale organization of convection within the equatorial waveguide takes the form of MJO-like (Madden,Julian Oscillation) coherent structures. First, CRCP simulations are performed in which development of large-scale free-tropospheric moisture perturbations is artificially suppressed using relaxation with a timescale of one day. As in previous simulations where much shorter relaxation timescale was used, MJO-like coherences do not develop and, if already present, they disintegrate rapidly. Second, CRCP simulations that start from planetary-scale moisture perturbation in the free troposphere are conducted. The ensuing large-scale velocity perturbations have e-folding times of five and seven days, respectively, for interactive and prescribed radiation simulations. This supports the conjecture that interactive radiation enhances moisture,convection feedback; an enhanced large-scale circulation results from differences in radiative cooling between areas having enhanced and suppressed convectively-generated moisture and cloudiness. Additional support for the role of moisture,convection feedback in intraseasonal oscillations is seen in simulations that apply the Emanuel scheme. The standard configuration of the Emanuel scheme is insensitive to free-tropospheric humidity and results in weak MJO-like coherences. A simple modification of the Emanuel scheme that enhances its sensitivity to free-tropospheric humidity dramatically improves the simulated MJO-like coherences. Copyright © 2004 Royal Meteorological Society [source]

    Changes in the proximate composition of bluefin tuna (Thunnus thynnus) reared in the cages located on the Gulf of Antalya (Turkey's Western Mediterranean coast) during the fattening period

    Pinar Yerl, kaya
    Abstract The aim of this study was to investigate the changes in the proximate composition of bluefin tuna (Thunnus thynnus) muscle reared in cages during the fattening period. Samples were taken from tunas at monthly intervals between July and October. Moisture, crude protein, crude fat and crude ash were analysed. The fat and ash contents increased, and the moisture content decreased during the fattening period. There were no significant differences in the protein content during this period. The mean protein concentration was 21% over this period. The highest levels of dry matter (40%), fat (15%) and ash (1.21%) were found in October. Baitfish (Sardina pilchardus, Sardinella aurita and Alosa fallax nilotica) were also analysed. There were no differences in the moisture, protein and fat contents between baitfish, but a lower ash content was found in sardine than in the others. The mean moisture, protein, fat and ash contents of baitfish were found to be 68.28%; 19.2%; 8.5%; and 1.4% respectively. [source]

    Phosphorus requirement of Catla (Catla catla Hamilton) fingerlings based on growth, whole-body phosphorus concentration and non-faecal phosphorus excretion

    Krishna Sukumaran
    Abstract A 120-day feeding trial was conducted to determine the dietary requirement of phosphorus for Indian major carp, catla (Catla catla) fingerlings. Four hundred and eighty fingerlings (mean body weight: 4.23±0.87 g) were randomly distributed among eight treatment groups with three replicates each. Eight isonitrogenous and isocaloric semi-purified diets (crude protein: 35% and crude lipid: 8.5%) were formulated with graded levels of phosphorus using KH2PO4 (T1: control, 0.1%; T2: 0.3%; T3: 0.5%; T4: 0.7%; T5: 0.9%; T6: 1.1%; T7: 1.3%; T8: 1.5%) and fed to the respective groups. Twenty fish were stocked in 150 L plastic tanks and fed to apparent satiation twice a day. Specific growth rate (SGR) significantly (P<0.05) increased with increasing dietary phosphorus concentration from 0.73% to 1.27%, after which there was a slight decline in growth at 1.1% available phosphorus (aP) and remained constant thereafter. The quadratic broken-line model based on growth was Y=317.5,581(0.64,x) (0.64,x); R2=0.73. Moisture and crude protein contents of whole body were similar among all the treatments. However, the ether extract in T1 group was significantly (P<0.05) higher than all the other treatments. The whole-body phosphorus content increased significantly (P<0.05) with an increase in phosphorus in the diets. The one-slope broken-line model based on whole-body phosphorus concentration was Y=4.07,1.63 (0.71,x); R2=0.48. The one-slope broken-line model for non-faecal phosphorus excretion as inorganic phosphorus (Pi) for 24 h revealed a trend of Y=12.67+73.96 (x,0.6); R2=0.81. Minimum aP requirements based on weight gain (%), whole-body phosphorus content and phosphorus excretion were 0.64%, 0.71% and 0.6%, respectively. Hence, the dietary aP requirement of catla fingerlings ranges from 0.6% to 0.71%. [source]

    Ist die Hinterlüftung von Holzfassaden ein Muss?

    BAUPHYSIK, Issue 3 2010
    Daniel Kehl Dipl.-Ing. (FH)
    Hygrothermal model; Wood moisture Feuchte Moisture Abstract Nach Durchführung einer großen Schweizer Forschungsinitiative zum Thema "Brandschutz im Holzbau" sind seit 2005 Außenwandbekleidungen aus Holz unter Zuhilfenahme von bestimmten Brandschutzmaßnahmen bis zur Hochhausgrenze (22 m) möglich [1]. Dazu zählen unter anderem auch Außenwandbekleidungen, deren Hinterlüftungsraum geschossweise unterbrochen und oben verschlossen wird. Solche Fassaden weisen brandschutztechnische Vorteile auf, da sie die Brandweiterleitung hinter der Bekleidung reduzieren bzw. verhindern. In diesem Zusammenhang stellte sich die Frage, ob eine Hinterlüftung von Holzfassaden aus bauphysikalischer Sicht überhaupt notwendig ist. Im Rahmen eines Forschungsvorhabens an der Berner Fachhochschule , Architektur, Holz und Bau in Biel/Bienne wurde dieser Frage nachgegangen [2]. Is ventilation of timber façades essential? Following a major Swiss research initiative, "Fire protection in Timber Structures", exterior timber wall claddings incorporating specific fire protection measures have been permitted up to the high-rise limit of 22 m since 2005 [1]. This includes exterior wall claddings with a ventilation space that is interrupted and closed off from above at each storey level. Such façades have advantages when it comes to fire protection as they reduce or prevent the spread of fire behind the cladding. This has raised the question of whether the ventilation of timber façades is necessary at all from a building physics perspective. This matter was investigated as part of an Architecture, Timber and Construction research project at Bern University of Applied Sciences [2]. [source]

    Debridement and wound bed preparation

    Anna F. Falabella
    ABSTRACT:, Debridement can play a vital role in wound bed preparation and the removal of barriers that impair wound healing. In accordance with the TIME principles, debridement can help remove nonviable tissue, control inflammation or infection, decrease excess moisture, and stimulate a nonadvancing wound edge. There are many types of debridement, each with a set of advantages and disadvantages that must be clearly understood by the healthcare team. Failure to use the correct debridement method for a given type of wound may lead to further delays in healing, increase patient suffering, and unnecessarily increase the cost of care. This review article discusses the various methods of debridement, describes currently available debriding agents, evaluates the clinical data regarding their efficacy and safety, and describes strategies for the management of problematic nonhealing wounds. [source]

    The role of Late Holocene climate variability in the expansion of yellow birch in the western Great Lakes region

    Stephen T. Jackson
    Abstract. Pollen records from the western Great Lakes region of North America show substantial increases in birch pollen percentages during the late Holocene. The vegetational and population dynamics underlying the birch increase have received little attention, in part because of the inability to discriminate among species of birch based on pollen morphology. We used analyses of pollen and plant macrofossils from four lakes in the Upper Peninsula of Michigan to document that the birch pollen increase represents a regional expansion of yellow birch (Betula alleghaniensis) populations, which was initiated c. 4500 years ago. Whether yellow birch invaded the region at this time or simply expanded from small, previously established populations is not clear, although it probably did not grow near our study sites before the expansion. The initial expansion occurred during an independently documented period of high moisture and high water levels in Lake Michigan. A subsequent expansion in yellow birch abundance and distribution occurred c. 3000 years ago, coinciding with a second period of increased moisture and high lake-levels. The yellow birch expansion may have been modulated by millennial-scale climate variability, with most rapid expansion occurring during relatively wet periods. [source]

    Development of spray- and freeze-dried high-concentration sesamol emulsions and antioxidant evaluation in fibroblasts and UV-exposed rat skin slices

    Juliana Alencar
    Abstract Dry sesamol emulsions were synthesized from several combinations of saccharose with hydroxypropylmethylcellulose (HPMC) or sodium caseinate (SC) using spray-drying techniques at 120° to 180°C, or freeze-drying. On the basis of physical characteristics such as droplet size distribution, residual moisture, and microscopic structure, the best material was obtained when spray-drying was applied at either 150° or 180°C with SC or HPMC as excipients, respectively. The extent to which the antioxidant properties of free sesamol towards a set of free radicals (galvinoxyl, diphenylpicrylhydrazyl, superoxide, and hydroxyl) were altered in the starting and reconstituted liquid emulsions submitted to normal storage or pre-exposed to a flux hydroxyl radicals was investigated. Emulsions were further evaluated for their antioxidant properties in cultured 3T3 murine fibroblasts and in an ex vivo model of ultraviolet irradiated rat skin. It was found that, in the material having the best physical properties, encapsulation was decisive in: (1) improving the overall antioxidant behavior of reconstituted versus starting liquid emulsions: (2) sparing sesamol consumption due to free radical attack; and (3) significantly protecting cells and skin against free radical- or irradiation-induced enzymatic release and/or lipid peroxidation. Demonstrating a high activity at high dilutions where interactions of excipient become negligible, the new emulsions could be of great interest in sesamol-based pharmacology or topical applications. Drug Dev Res 69:251,266, 2008. © 2008 Wiley-Liss, Inc. [source]

    Microbiotic crusts as biomarkers for surface stability and wetness duration in the Negev Desert

    Giora J. Kidron
    Abstract Microbiotic crusts play an important role in arid and semi-arid regions. Yet, very little information exists regarding the factors that impact their development. In an attempt to assess the main factors that may determine their growth, measurements of the amount of fines (silt and clay), rain, moisture content, wetness duration and wind erosion and deposition were carried out along a 12 station transect within a partially crusted dune field in the western Negev Desert and compared to the crust cover and chlorophyll content. Surface stability was the only variable that exhibited significant relationship with crust cover while daylight wetness duration exhibited strong positive relationship (r2 = 0·92,0·99) with the crust's chlorophyll content. The data point out that microbiotic crusts may serve as a useful biomarker for surface stability. While wetness duration and wind will control crust cover and the crust chlorophyll content in semi-stable habitats (with absolute annual change in sand level of 2,3 mm), stable habitats (absolute change <1 mm) will be controlled primarily by moisture, while habitats with low surface stability (absolute change of tens and hundreds of millimeters) will be primarily controlled by wind. Furthermore, owing to the strong positive relationship between daylight wetness duration and the crust's chlorophyll content, the crust may serve as a useful biomarker for the quantification of surface wetness duration. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Small-scale variability in surface moisture on a fine-grained beach: implications for modeling aeolian transport

    Brandon L. Edwards
    Abstract Small-scale variations in surface moisture content were measured on a fine-grained beach using a Delta-T Theta probe. The resulting data set was used to examine the implications of small-scale variability for estimating aeolian transport potential. Surface moisture measurements were collected on a 40 cm × 40 cm grid at 10 cm intervals, providing a total of 25 measurements for each grid data set. A total of 44 grid data sets were obtained from a representative set of beach sub-environments. Measured moisture contents ranged from about 0% (dry) to 25% (saturated), by weight. The moisture content range within a grid data set was found to vary from less than 1% to almost 15%. The magnitude of within-grid variability varied consistently with the mean moisture content of the grid sets, following an approximately normal distribution. Both very wet and very dry grid data sets exhibited little internal variability in moisture content, while intermediate moisture contents were associated with higher levels of variability. Thus, at intermediate moisture contents it was apparent that some portions of the beach surface could be dry enough to allow aeolian transport (i.e. moisture content is below the critical threshold), while adjacent portions are too wet for transport to occur. To examine the implications of this finding, cumulative distribution functions were calculated to model the relative proportions of beach surface area expected to be above or below specified threshold moisture levels (4%, 7%, and 14%). It was found that the implicit inclusion of small-scale variability in surface moisture levels typically resulted in changes of less than 1% in the beach area available for transport, suggesting that this parameter can be ignored at larger spatial scales. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Simulation of the dissolution of weathered versus unweathered limestone in carbonic acid solutions of varying strength

    M. J. Thornbush
    Abstract A simulation was undertaken within a climatic chamber to investigate limestone dissolution under varied carbonic acid (H2CO3) strengths as a possible analogue for future increases in atmospheric CO2 arising from global warming. Twenty-eight samples cut from a block of Bath (Box Hill) limestone from Somerville College, Oxford, which had been removed during restoration after 150 years in an urban environment, were weighed and placed in closed bottles of thin plastic containing varying concentrations of H2CO3. Half of the stone samples were derived from exposed surfaces of the stone block (weathered) while the others were obtained from the centre of the block on unexposed surfaces (unweathered). The purpose of this was to compare dissolution of previously weathered versus unweathered surfaces in strong (pH 4·73) versus weak (pH 6·43) solutions of H2CO3. A temperature of c. 19 °C was maintained within the chamber representing a plausible future temperature in Oxford for the year 2200 given current warming scenarios. The simulation lasted 25 days with a few stone samples being removed midway. Stone samples show reduced weight in all cases but one. There was greater dissolution of stone samples in a strong H2CO3 solution as conveyed by higher concentrations of total hardness and Ca2+ in the water samples as well as enhanced microscopic dissolution features identified using SEM. The simulation confirms that enhanced atmospheric CO2 under global warming, given adequate moisture, will accelerate dissolution rates particularly of newly replaced limestone building stones. However, previously weathered surfaces, such as those on historical stone exposed for a century or more, appear to be less susceptible to the effects of such increased rainfall acidity. Conservation techniques which remove weathered surfaces, such as stone cleaning, may accelerate future decay of historical limestone structures by increasing their susceptibility to dissolution. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Two-hourly surface change on supra-tidal rock (Marengo, Victoria, Australia)

    Lluís Gómez-Pujol
    Abstract A traversing micro-erosion meter was used to measure rock surface micro-topography over 40 cm2 on a supra-tidal cliff face from early morning to late evening in late spring. From 06:00 hours to 22:00 hours the relative heights of 188 coordinates were obtained using the meter at 2-hour intervals, resulting in a data set of 1607 readings. Monitoring shows that rock surfaces are dynamic entities, with significant rise and fall relative to the first measurement at shorter timescales than previously reported. The maximum positive rise between readings was 0·261 mm and lowering was 0·126 mm. The pattern of change did not relate as expected to environmental variables such as temperature or insolation. Rather, the surface showed greater surface change in the early morning and late afternoon. It is hypothesized that this pattern relates to the expansion and contraction of lichen thalli as moisture is absorbed during higher humidity in the morning and late afternoon. The implications of these results for weathering studies are considered. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Measurement and data analysis methods for field-scale wind erosion studies and model validation,

    Ted M. Zobeck
    Abstract Accurate and reliable methods of measuring windblown sediment are needed to con,rm, validate, and improve erosion models, assess the intensity of aeolian processes and related damage, determine the source of pollutants, and for other applications. This paper outlines important principles to consider in conducting ,eld-scale wind erosion studies and proposes strategies of ,eld data collection for use in model validation and development. Detailed discussions include consideration of ,eld characteristics, sediment sampling, and meteorological stations. The ,eld shape used in ,eld-scale wind erosion research is generally a matter of preference and in many studies may not have practical signi,cance. Maintaining a clear non-erodible boundary is necessary to accurately determine erosion fetch distance. A ,eld length of about 300 m may be needed in many situations to approach transport capacity for saltation ,ux in bare agricultural ,elds. Field surface conditions affect the wind pro,le and other processes such as sediment emission, transport, and deposition and soil erodibility. Knowledge of the temporal variation in surface conditions is necessary to understand aeolian processes. Temporal soil properties that impact aeolian processes include surface roughness, dry aggregate size distribution, dry aggregate stability, and crust characteristics. Use of a portable 2 tall anemometer tower should be considered to quantify variability of friction velocity and aerodynamic roughness caused by surface conditions in ,eld-scale studies. The types of samplers used for sampling aeolian sediment will vary depending upon the type of sediment to be measured. The Big Spring Number Eight (BSNE) and Modi,ed Wilson and Cooke (MWAC) samplers appear to be the most popular for ,eld studies of saltation. Suspension ,ux may be measured with commercially available instruments after modi,cations are made to ensure isokinetic conditions at high wind speeds. Meteorological measurements should include wind speed and direction, air temperature, solar radiation, relative humidity, rain amount, soil temperature and moisture. Careful consideration of the climatic, sediment, and soil surface characteristics observed in future ,eld-scale wind erosion studies will ensure maximum use of the data collected. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    The influence of groundwater on surface flow erosion processes during a rainstorm

    D. L. RockwellArticle first published online: 27 MAY 200
    Abstract Surface erosion rates on a disturbed natural soil in a 10 m indoor flume increased by an order of magnitude when a water table developed at a 10 cm depth during simulated rainstorms. Erosion rate increases did not correlate well with surface hydraulic flow conditions, and all significant erosion increases began before the full soil depth was saturated, before the water table reached the soil surface, and before seepage was possible. Groundwater influenced erosion processes primarily by increasing unsaturated pore-water pressures and decreasing soil shear strength in surface rainflow, rather than through the direct entrainment of soil particles by seepage flow. There was no unique morphologic expression of the influence of groundwater during a rainstorm. Subsurface processes influencing surface erosion were detected only by appropriate subsurface instrumentation, which included micropiezometers, tensiometers and time domain reflectometry. Erosion rate increases occurred all along the slope, and were not concentrated at the base of slope due to a seepage zone. Soil depth was crucial to determining surface erosion increase. It is likely that confusing trends in surface flow erosion rates in past studies have occurred due to unrecorded groundwater development or an emphasis on seepage effects. Groundwater must be monitored along hillslopes under all moisture and soil conditions in order to avoid misleading and inconsistent conclusions derived solely from surface flow or seepage data. Copyright © 2002 John Wiley & Sons, Ltd. [source]

    A test of the relationship between seasonal rainfall and saguaro cacti branching patterns

    ECOGRAPHY, Issue 4 2003
    Taly Dawn Drezner
    Reproductive output, as well as photosynthetically active radiation interception and CO2 uptake, increase as saguaro cacti Carnegiea gigantea (Engelm.) Britt. and Rose branch, and branching increases with increasing moisture. The Sonoran Desert experiences distinct summer and winter precipitation regimes that vary in both geography and scale. Many aspects of saguaro ecology are known to depend on the summer rains, which has resulted in an emphasis on summer rains in the literature. Similarly, branching studies have been limited geographically to areas that receive relatively high amounts of summer rainfall. These studies, therefore, attribute branching patterns to the summer (or possibly annual) rains, and conclusions reflect the summer precipitation bias. Environmental variability in space was explored in the present study to investigate saguaro branching patterns. I collected height and branching data in thirty saguaro populations across their American range. Stepwise regression was used to determine which climate, vegetation and soil variables best predict branching. Contrary to the literature, this study found that winter precipitation, particularly from January to April, was the best predictor of branching, not summer or annual rain. Surprisingly, the relationship between the summer monsoons (July and August precipitation) and branching was negative. This is likely due to the fact that summer and winter rainfall patterns are geographically distinct. Winter precipitation appears to play a key role in branching, and thus in seed production. This suggests that saguaros benefit from moisture during the winter, possibly utilizing cold-season rains for increasing their reproductive output through branching, and challenging the view that the summer rains dominate virtually every aspect of the saguaro life-cycle, and creating a more balanced view of saguaro ecology. [source]