Search

This study developed a multifunctional paper-based freshness antibacterial indicator card by dual-sided coating on conventional filter paper. The indicator coating was composed of anthocyanins from purple cabbage, and polyvinyl alcohol and sodium carboxymethyl cellulose as substrates while the antibacterial coating contained halloysite nanotubes for loaded thyme essential oil and chitosan. FT-IR, XRD, and SEM analyses revealed that the components were well-mixed, and the paper was tightly bound to the coatings through hydrogen bonds. Additionally, the coating effectively filled the porous fiber gaps in the paper, significantly enhancing the mechanical properties of the paper. The tensile strength of the coated paper was enhanced from 14.28 MPa to a range of 42.25-47.71 MPa, and the bending resistance was increased from 0.35 N·mm to a range of 1.72-1.99 N·mm compared to the uncoated paper. The addition of anthocyanins provided excellent sensitivity to pH and ammonia for the indicator card. Furthermore, the coating including halloysite nanotubes for loaded thyme essential oil exhibited antimicrobial resistance against Escherichia coli and Staphylococcus aureus. When used on fresh carp, the antibacterial indicator card not only indicated the freshness of the carp but also extended the best before date of the fish meat by 1-2 days. The indicator exhibited the most pronounced color transformation and optimal freshness indication performance when the mass fraction of anthocyanins was 2 %., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. This work is original research and the data presented in the manuscript has not been published elsewhere., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The production of pulp and paper from recycled paper generates significant quantities of deinking paper sludge (DPS). This sludge contains a significant amount of organic matter (36%) as well as heavy metals such as Pb, Zn, and Cr. In this work, the incorporation of DPS (0%, 8%, 10%, and 12%) in the manufacture of clay bricks leads to valorization of this waste by showing that two of its contents considered problematic (organic matter and heavy metals) have several positive effects. It was found that the organic parts were transformed into pores after brick firing (850°C), which improved thermal insulation while keeping mechanical resistance in conformity with usual standards. For the heavy metals, which make DPS a hazardous waste, a leaching test was employed. The results show that these metals were trapped in the ceramic matrix after the firing of bricks at a high temperature, resulting in a final product that was not dangerous. Other tests were carried out on bricks with DPS to evaluate density, water absorption, shrinkage, loss on ignition, porosity, and microstructure in order to characterize this new product. It was concluded that DPS can be used in clay bricks as an asset for the formation of pores to enhance thermal insulation. The addition of DPS can be optimized at 10% to comply with the standard and not exceed the required values for shrinkage, water absorption, and loss on ignition. [ABSTRACT FROM AUTHOR]

The thermal degradation of paper mill waste (PMW) has been investigated in presence and absence of Montmorillonite clay in the temperature range of ambient to 1000 °C and at the heating rates of 20 °C/min, 25 °C/min and 30 °C/min. Proximate and ultimate analyses and evaluation of calorific value (HHV) of PMW have been carried out using standard protocols. The thermo-gravimetric analysis (TGA) and differential thermogravimetric (DTG) data obtained under both situations have been used to evaluate the kinetic and thermodynamic parameters and elucidate the reaction mechanism. The clay has also been characterized using TGA/DTG analysis, Fourier Transform Infra-Red (FTIR) spectroscopic analysis and X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS), and scanning electron microscopic (SEM) techniques. The activation energy, pre-exponential factor and thermodynamic parameters have been evaluated using the model-free iso-conversional method of Flynn-Wall-Ozawa (FWO) and Vyazovkin and the distributed activation energy model (DAEM). The Montmorillonite clay has influenced the degradation process appreciably through its catalytic action., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The objective of this work is to produce an ecologically friendly material for use in Ivory Coast's construction sector in the future. These materials should have good thermal qualities and be flame resistant in addition to helping to achieve interior comfort. The fundamental components under consideration are freely accessible in Ivory Coast and include clay mortar as a fire retardant, potato starch as a binder, and recycled paper granules as a filler. The suggested ecologically friendly material's manufacturing process is fully described in detail. After conditioning, the team created multiple samples, taking into account that each test that the materials are put through requires various probe sizes for the thermal conductivity test, the reaction to fire test, and the flexural strength test. The best result regarding thermal conductivity of composites was obtained when 10 % clay is added in the mixture, namely between 0.057 … 0.068 W/(mK). During the ignitability tests the flame did not propagate to a height greater than 15 cm throughout the 60 s test time, so it can be concluded that the materials match minimally in the class E of reaction to fire. The flexural strength of tested materials was under 0.8 MPa.

The growing concern for environmental sustainability has created an urgent need for the development of innovative and environmentally friendly packaging materials. Among the various options available, clay-starch nanocomposites have emerged as a promising avenue for improving the barrier properties and mechanical strength of paper substrates. In this scientific paper the importance of clay-starch nanocomposite coatings on paper substrate and highlight the role of computer simulations, especially molecular dynamics, in elucidating their structural and functional properties. It has been shown that phyllosilicates with a layer charge < 0.4 electrons per stoichiometric unit can intercalate starch in the interlayer space, forming a barrier for water vapor in the covering layer. Phyllosilicates with a shell charge of > 0.4 electrons per stoichiometric unit were not able to intercalate starch. Thus, clay-starchnanocomposites can provide limited water vapor transfer rates and can be recommended asa promising material for dry food packaging.

Paper sludge is the water treatment waste, which produced during paper production. Paper sludge (PS) waste utilization is the common problem in the EU and internationally. According to the waste management directive No. 2008/98/EC, paper sludge waste should not be utilized in landfills. In the European Union, alone 93 million tons of PS generated yearly. Nowadays most of the paper sludge waste used as fuel for incineration power plants (up to 55 %). According to waste management legislation such waste management should be avoided as well. Very small portion (10 %) of PS is used in construction sector. In construction, paper sludge used as additive in concrete composite materials. Such legislation of waste management generates the motivation of this study. In this study authors propose to produce composite panels in which PS is the main material of composite. As the binding material, clay proposed due to its good binding properties and therefore its natural material. Such produced panels proposed to use it for sound absorption applications. To determine composites sound absorption coefficient standard ISO 10534-2 method was used. The sound absorption coefficient in different octave bands reached up to 0.59.

The Nordtest method evaluates the moisture buffer value (MBV) of materials that are being exposed to indoor air. The test simulates daily variations (high RH of 75% for 8 hours, low RH of 33% for 16 hours) in MBV, which in this context refers to the moisture uptake/release in the material when it is exposed to relative humidity (RH) in a square wave. We are looking for ways to increase clay plasterâs ability to buffer moisture. Which material has simultaneously a higher ability to buffer moisture and can be added to the clay plaster mixture? The recipe for the specimen included the following: waste paper (newspaper paper), glue (methylcellulose), clay and water. Our research showed that adding paper plaster mixture to the clay plaster mixture increases the moisture buffering ability of the plaster. The bigger the amount of added paper plaster, the better the plasterâs ability to buffer moisture.

Waste management is the protection of the environment and the health of the population. Paper waste sludge is produced during paper production and sepiolite is a natural clay mineral. The aim of the study was to investigate the usability of sepiolite-added paper waste sludge as a bedding material in the broiler production. Two hundred eighty-eight 1-day old male broiler chicks were divided into the 6 bedding material groups (wood shavings (control), paper waste sludge, sepiolite, mix of 25% paper waste sludge and 75% sepiolite, mix of 50% paper waste sludge and 50% sepiolite, and mix of 75% paper waste sludge and 25% sepiolite) with 6 replicate pens per group. Litter quality, performance, and some welfare parameters of broilers were assessed during the 6 weeks' period. Body weight at 42 days of age and body weight gain from 0 to 42 days of broilers reared on the wood shavings and mix of 50% paper waste sludge and 50% sepiolite were found higher than those of the sepiolite and paper waste sludge groups. Feed consumption and feed to gain ratio from 0 to 42 days, yields of carcass and carcass parts, percentages of organs and abdominal fat, IgG, percentage of bursa Fabricius, burns of foot pad and breast, litter pH and meat properties of broilers reared on the wood shavings, paper waste sludge, and sepiolite litter groups were not found to be statistically different. Litter moisture was found higher in the paper waste sludge group than that in the sepiolite group at the 42 days of rearing. As a conclusion, usage of mix of 50% paper waste sludge and 50% sepiolite as a litter does not have any negative effects on performance, welfare, and litter quality. This result is important in terms of utilizing a waste product. [ABSTRACT FROM AUTHOR]

The Nordtest method evaluates the moisture buffer value (MBV) of materials that are being exposed to indoor air. The test simulates daily variations (high RH of 75% for 8 hours, low RH of 33% for 16 hours) in MBV, which in this context refers to the moisture uptake/release in the material when it is exposed to relative humidity (RH) in a square wave. We are looking for ways to increase clay plaster's ability to buffer moisture. Which material has simultaneously a higher ability to buffer moisture and can be added to the clay plaster mixture? The recipe for the specimen included the following: waste paper (newspaper paper), glue (methylcellulose), clay and water. Our research showed that adding paper plaster mixture to the clay plaster mixture increases the moisture buffering ability of the plaster. The bigger the amount of added paper plaster, the better the plaster's ability to buffer moisture. [ABSTRACT FROM AUTHOR]

The use of clay filler materials in dispersion coatings is a well-established method to provide improved barrier properties to the coated paper substrate, in particular lowering the water vapour transmission rate (WVTR) through the coating. In this paper we demonstrate the use of small spherical silica particles (È100-220 nm) as an additive to a clay-latex coating formulation is able to provide further improvements to the barrier properties, when compared to the equivalent silica-free coatings. A significant decrease in both the water vapour transmission rate and the direct water uptake of water (Cobb120 wettability test) is observed for coatings containing as little as 1% silica additive.

Soil-fluid retention (SFR) is considered a fundamental unsaturated property with a wide application from transient flow analysis, and strength prediction to constitutive modeling. Previous research has led to a consensus that soil microstructure can significantly affect retention properties. Furthermore, the soil microstructure is subject to changes due to variations in the sampling method and pore fluid chemistry. Therefore, this study aims to explore the influence of multiple factors, including sample preparation technique, dissolved salt concentration and cation type, on soil-fluid retention and volumetric behavior in a systematic manner. The results of tests conducted by employing the axis translation and filter paper methods are interpreted in detail based on some complementary scanning electron microscopy and micro-CT scan experiments. Furthermore, the repeatability of the test results is validated through some control tests. The results reveal a higher retention capacity for reconstituted samples compared with the compacted ones independent of the solute concentration. In contrast, both the SFR and shrinkage are suppressed by the addition of sodium chloride to the pore fluid independent of the sample preparation method. It is also found that the SFR capability of potassium cation is less than that of sodium cation at the same concentration. The SFRs are quantified and compared in terms of air entry/air expulsion suction, hydraulic hysteresis and desorption/adsorption rates. The interpretation of the results in light of the diffuse double-layer theory is supported by microstructural observation and provides insights into the SFR of lean clays exposed to saline environments with different types of salt species. [ABSTRACT FROM AUTHOR]

Silver-clay nanohybrids based on silver nanoparticles (AgNPs) with montmorillonit (MMT) and milled MMT, shortly AgMMTnano and AgMMTmilled, have been prepared to improve the performance of antibacterial properties of paper. The results obtained by dynamic light scattering indicated the presence of silver particles in the nanometer range, which have a great accumulation tendency. The results of AAS and ICP-AES tests showed that nanosilver amount in the AgMMTmilled was doubled compared to the AgMMTnano, but according to the EDX results, the amount of nanosilver in paper treated with the former was less than in the latter. FE-SEM images showed that the dimensions of deposited nanosilver on the surface of clay were smaller than in case of AgNPs alone. Papers treated with nanohybrids had better antibacterial properties compared to that prepared by naked nanosilver. It was also found that the antibacterial property of papers treated with AgMMTnano were more stable during three-stage tests compared to those with AgMMTmilled. Nanohybrids with Ag conc. more than 15 ppm, especially hybrids with Ag conc. of 50 ppm, result in a significant improvement in antibacterial properties of paper. It can be concluded that silver-clay nanohybrid with a 25-ppm concentration of nanosilver could be the best and most economic antibacterial component. [ABSTRACT FROM AUTHOR]

Cement stabilization is a widely applied technique in improving the workability and geotechnical properties of soft clay. This paper investigated the influence of cement stabilization on the soil–water characteristic curve (SWCC) and the deformation behavior of unsaturated cement–stabilized soft clay. The combined effect of cementation and partial saturation on the hydromechanical behavior of cement-stabilized soils was discussed. The SWCC of stabilized soil was measured in the full suction range under drying and wetting paths using the pressure plate method, the filter paper method, and the vapor equilibrium technique. The deformation behaviors of cement-stabilized soft soil were investigated by conducting suction-controlled oedometer tests. Furthermore, scanning electron microscope micrographs and mercury intrusion porosimetry tests were performed to investigate the effects of cement content on the evolution of soil pore structures. The test results showed that the water retention capacity of the stabilized soft clay increased with increasing cement content. The SWCC showed a significant hysteretic behavior in the boundary effect zone and transition zone, whereas the hysteretic effect was unapparent in the residual zone. The increased cement content had a more significant hysteretic effect on the SWCC. The deformation resistance capacity increased as the cement content and matric suction increased. However, the effect of matric suction on deformation resistance capacity decreased as the cement content increased. With the increase in cement content, the macropores were converted to small interaggregate pores, the pore spaces were distributed more uniformly, and the particle surface became rougher, resulting in higher water retention capacity and significant hysteresis of the SWCC. [ABSTRACT FROM AUTHOR]

The article describes the compositions with red clay, as principal component, for utilization of paper production sludge and scrap glass to fabricate red ceramics at sintering temperatures of 700°, 800°, 850°, 900°, 1000°, 1050° and 1100 °C. The raw and final materials were analyzed by XRF, XRD, SEM, EDS and LAMMA methods. The flexural strength tests of obtained ceramics reached till 11.7 MPa, water absorption till 12.6%, bulk densities varied from 1.79 to 1.86 g/cm 3 , and shrinkage till 1.4%. These properties can be attributed to the sintering at 700° and 1100 °C of ceramics with glassy structures and small inclusions of new crystalline minerals, such as mullite, albite, orthoclase and nepheline. [ABSTRACT FROM AUTHOR]

The presence of intensely fissured soils is often found to relate to high geotechnical risks, such as landslide risk. This is especially the case of the Southern Apennines, Italy, where slopes formed of intensely fissured clays are frequently affected by landslides. The latter are generally triggered by rainfall infiltration, which takes place through the outcropping, unsaturated clayey soil cover. With the final aim of reducing landslide risk in areas covered by fissured clays, a detailed hydro-mechanical characterisation of these materials is required. While the behaviour of fully saturated fissured clays has been investigated in the last decade, only a few studies dealing with unsaturated, natural fissured clays are reported in the literature. The present paper aims to give a contribution toward filling this gap by extending an investigation campaign started a few years ago on the Paola Doce fissured clay outcropping on the Pisciolo slope (Southern Apennines, Italy). The physical properties of the material and some of its key micro- to meso-structural features are first analysed, the latter also based on Scanning Electron Microscope (SEM) micrographs of an undisturbed sample taken at 1.4 m depth on the Pisciolo slope, which is mainly formed of Paola Doce clay. Subsequently, water retention data of the soil are presented, which were obtained using both high-capacity tensiometers and the filter paper technique. These data were collected not only on undisturbed samples but also while subjecting the same material to drying paths. The results herein reported aim to make a link between the water retention behaviour of the Paola Doce clay sampled at Pisciolo and its fissured structure. [ABSTRACT FROM AUTHOR]

Dispersion coatings are offered as alternative solutions to extrusion coating technology for paper-based packaging. In addition to providing barrier properties, waterborne dispersions may implement the processing and converting properties of coated substrates, which are of extreme interest for an effective transfer to the industry. In this work, styrene-butadiene-based aqueous dispersions were formulated considering different amounts of kaolin as pigment. The authors assessed the heat-seal ability, fold cracking resistance, and blocking tendency, comparing the results against commercial dispersion coating grades. Kaolin content dominated the sealing behavior of experimental formulations, changing the minimum heat-seal temperature from 80 °C to >140 °C for 0% and 60% kaolin solid content, respectively. On the contrary, commercial grades were mostly affected by temperature. Additionally, despite the low latex glass temperature (0 °C), experimental formulations generally showed little, if any, blocking. On the downside, increasing kaolin content eases fold cracking, showing a different magnitude according to fold direction and coat orientation yet achieving a higher moisture barrier compared to commercial grades for both folded and unfolded samples. [ABSTRACT FROM AUTHOR]

Dispersion coating may represent an alternative technology to extrusion coating, currently dominating the market of coated paper-based packaging. Being processed as inks, dispersion coatings can be applied with conventional equipment, achieving lower dry coat grammages. In this work, two styrene-butadiene-based (Tg1 ≅ 0 °C; Tg2 ≅ 15 °C) dispersion coatings filled with different amounts of kaolin were developed and rod-coated on two different paper substrates. The samples were tested for water, moisture, and grease barrier properties. Kaolin-containing formulations showed moisture barrier as low as 15 g/(m2∙day), as well as grease barrier higher than 24 h. The best formulation involved 20% by weight of kaolin, whereas higher amounts were detrimental for water barrier, beneficial for moisture barrier, and slightly detrimental for grease barrier properties. Benchmarked to two commercial grades, kaolin-filled coatings strongly improved grease barrier, yet achieving similar moisture barrier. [ABSTRACT FROM AUTHOR]

In this work, the influence of lignosulfonate (LS), which is a by-product of timber and paper industries, on the cyclic characteristics of expansive clay was investigated by conducting cyclic triaxial tests. Test findings showed that cyclic stress ratio (CSR) substantially influenced liquefaction resistance of treated soil samples such that, at CSR = 0.2, none of the specimens were liquefied, whereas, at CSR = 0.4, all of the specimens were liquefied. Furthermore, liqueaction resistance was enhanced by decreasing the sample moisture content. Due to a stabilisation effect, the secant shear modulus increased by up to about 64%, and the damping ratio decreased by up to about 22%. [ABSTRACT FROM AUTHOR]

This study deals with the recovery of deinking sludge (DS) generated during waste paper recycling. The aim is to integrate this sludge in the fired-bricks formulation with different percentages. These mixtures are fired, and the study of the general aspect, loss on fire, and water absorption enables characterization of this material. Different compression tests are carried out on studied samples to characterize the strength and compare its performance to the standard. The mixtures' optimization and the elaboration conditions are the main objectives to obtain a new construction material with competitive performances conforming to the standards. [ABSTRACT FROM AUTHOR]

Osmotic suction affects the mechanical properties of the clay and exists as long as the solute is present in pore water of soil. Determination of osmotic suction of pore solution is significant for quantitatively explaining the mechanical behaviors of clay in saline solution. This paper aims to introduce a calculation method to determine the osmotic suction of saline solutions and the application of the osmotic suction to quantify the mechanical behaviors of clay in saline solutions. Osmotic coefficient as the bridge connecting ion concentration and osmotic suction was calculated by a simplified half-empirical equation and verified by published experimental data. Then the osmotic suctions were achieved using the calculated osmotic coefficients, and two filter paper methods were carried out to verify the calculated results. The consistency between the experimental results and the calculated ones proved the correctness of the proposed method for calculating the osmotic suction. A step further, the mechanical behaviors of clay in saline solutions were explained and quantified from the microscopic with the concept of microstructural effective stress and the macroscopic with the concept of modified effective stress, both related to the osmotic suctions. [ABSTRACT FROM AUTHOR]

• Reusability of PMS and CS provides economic and environmental benefits. • PMS and CS can be utilized as a pore making agent in sustainable brick manufacturing. • The energy efficiency problem of buildings can be solved using the produced lightweight and thermal insulated bricks. • ANOVA revealed that the characteristics of the fired bricks depends on the selected mixture ratio. In terms of sustainable and cleaner production, the utilization of various industrial wastes in the manufacturing of eco-friendly building materials has attracted attention in recent years. In the present study, a total of 12 series bricks were produced to determine the influences of paper mill sludge (PMS) and carbonation sludge (CS) on the physical, mechanical and thermal properties of clay based bricks. The following parameters were examined for the bricks produced at 1000 °C and 1100 °C; water absorption, apparent porosity, efflorescence, bulk density, compressive strength and thermal conductivity. For the fired brick production, CS was used up to 30% while PMS up to 15%. The compressive strength of the fired bricks having 15% CS and 5% PMS content were in accordance with the standards. The thermal conductivity ranged from 0.742 W/mK to 0.155 W/mK. Also, the influences of waste concentrations on the quadratic model were analyzed using analysis of variance (ANOVA). The analysis results indicate that the firing temperature is the least important parameter affecting all properties of brick. The use of wastes up to 20% in the brick structure is an important step both in terms of reducing environmental pollution and protecting natural clay resources. [ABSTRACT FROM AUTHOR]

Biochar (BC) is used as a soil amendment to enhance plant growth by improving mainly soil chemical and hydrophysical properties. In this work the effects of two types of BCs on soil water retention properties were analysed. The first type of BC was made from sugarcane bagasse. It was added to a clay "Shimajiri Maji" soil at an application rate of 3 w%. The second type of BC was made from paper fiber sludge and grain husks. It was added into a loam soil at rates of 3.6, and 7.3 w%. It was assumed that the effect of BC amendment will be more pronounced in coarse-grained soil than in fine-grained one. Therefore, the second type of BC was applied additionally in the silica sand, in a textured contrast material compared with the loam soil. The BC amendment caused statistically significant increase of water content in the transmission pores of the clay soil, in the storage pores of the loam soil, and in the macropores and the storage pores in the silica sand. Despite of the positive effect on soil water retention, statistically significant increase of available water capacity (AWC) was identified only in the loam soil with the larger BC amendment rate. Possible reasons are discussed. [ABSTRACT FROM AUTHOR]

In accordance with global estimations, approx. 15 million tons of residues are yearly generated from paper and pulp industry, which are traditionally used as biofuels or just disposed in landfills. However, residues composition and laws in force urge producers to search for new waste management strategies. From another point of view, the construction industry uses more than 33% of total natural resources, worldwide which has led several governments to limit the use of natural raw materials for building. In particular, fired brick industry produces yearly approx. 1600 billion bricks which represents millions of tons of natural resources consumption. Therefore, the goal is to contribute to reduce the amount of used clay. Thus, this paper explores the mineral and technological properties of brick made by using different percentages of paper pulp residues and fired at 900 °C. Results indicate that by increasing the replacement ratio, blend requires larger amounts of water which leads to a proportional increasing of shrinkage during drying. In spite of mineral transformations are not influenced by paper pulp residue, the porosity is linearly increased which leads to reduce compressive strength and thermal conductivity up to 30% for 20% of replacement ratio, in both cases. Thus, it is concluded that series made by replacing up to 10% show compressive strength above 5 MPa, water absorption beyond 20% and toxicity indexes meet the mandatory requirements. [ABSTRACT FROM AUTHOR]

The present study was conducted to modify kaolin clay by coating cationic starches, maize and tapioca, aimed at effective incorporation into recycled pulp fibers. The modification process was examined by using zeta potential, filler size, filler retention, and scanning electron micrograph (SEM) observations. In addition, paper sheets (65 ± 5 g/m2 basis weight) filled with unmodified kaolin or kaolin–starch filler followed by an internal sizing were fabricated and analyzed. Based on the results of zeta potential, the charge reversal of kaolin–starch particles substantiated the coating of kaolin fillers by cationic starches. Additionally, the kaolin–starch filler revealed a higher tendency to form clusters 3.5–7.5 times larger than the unmodified kaolin filler. Consistently, SEM images showed well–distributed kaolin–starch fillers, aggregated together and jointed to the fibers. Consequently, the paper filled with kaolin–starch fillers exhibited higher brightness and mechanical strengths indices compared to the unfilled papers, as well as the papers filled with unmodified kaolin. Interestingly, the results of water resistance and dynamic contact angle (DCA) indicated stable hydrophobic performance of kaolin–starch filled papers. • Kaolin clay was modified by cationic starch, aimed at fill PWC recycled papers. • The process contributed higher bonding and retaining to the kaolin–starch particles. • The recycled papers incorporated with modified kaolin filler have been fabricated. • The prepared papers revealed enhanced optical, strength and hydrophobic properties. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)