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Ricin is a highly-toxic compound derived from castor plant beans. Several incidents involving contamination of residences and buildings due to ricin production or dissemination have occurred in recent years. The goal of this study was to determine whether ricin bioactivity could be attenuated in reasonable time via simple modifications of the indoor environment. Attenuation was assessed on six different materials as a function of temperature, relative humidity (RH), and contact time, using both a pure and crude preparation of the toxin. Ricin bioactivity was quantified via a cytotoxicity assay, and attenuation determined as the difference in ricin recovered from test and positive controls. The results showed that pure ricin could be attenuated successfully, while the crude ricin was generally more persistent and results more variable. We found no significant attenuation in crude ricin after two weeks at typical indoor environmental conditions, except on steel. Attenuation mostly improved with increasing temperature, but the effect of RH varied. For pure ricin, heat treatments at 40°C for 5 days or 50°C for 2-3 days achieved greater than 96% attenuation on steel. In contrast, appreciable recovery of the crude ricin preparation still occurred at 40°C after two weeks., Competing Interests: The authors have declared that no competing interests exist.

Fibre crosslinking with polycarboxylic acids can be used to improve certain properties of paper products, including wet tensile and compressive strength. In the present work it was proposed that citric acid (CA) crosslinks the cellulosic fibres of linerboard by self-catalysed esterification of cellulosic hydroxyl groups, which makes an additional catalyst unnecessary. An increase in CA dose or curing temperature increased linerboard compressive strength. In CA-treated corrugated board most of the applied CA was esterified with fibres while some CA thermolysis products were also present. A significant portion of the applied CA was unaccounted for. The deficit was attributed to thermolysis to give volatile anhydrides of unsaturated acids. Under cyclic humidity and static compressive loading, CA-treated corrugated boxes showed a greater than three-fold increase in resistance to compressive creep, showing that CA treatment can be used to extend the lifetime of corrugated boxes used for horticultural produce storage., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Moisture distributions in municipal sewage sludge, printing and dyeing sludge and paper mill sludge were experimentally studied based on four different methods, i.e., drying test, thermogravimetric-differential thermal analysis (TG-DTA) test, thermogravimetric-differential scanning calorimetry (TG-DSC) test and water activity test. The results indicated that the moistures in the mechanically dewatered sludges were interstitial water, surface water and bound water. The interstitial water accounted for more than 50% wet basis (wb) of the total moisture content. The bond strength of sludge moisture increased with decreasing moisture content, especially when the moisture content was lower than 50% wb. Furthermore, the comparison among the four different testing methods was presented. The drying test was advantaged by its ability to quantify free water, interstitial water, surface water and bound water; while TG-DSC test, TG-DTA test and water activity test were capable of determining the bond strength of moisture in sludge. It was found that the results from TG-DSC and TG-DTA test are more persuasive than water activity test.

For paperboard used to produce packaging, treatment of its fiber constituents with commercial enzymes can improve its compressive strength under cycling and high-humidity conditions. Xylanase that selectively removes pulp xylan (ca. 2% of the pulp by mass) yielded most of the observed beneficial effects, which did not appear related to the packing of the fiber network in the sheet or to the uptake of moisture at high humidity. There was also a marginal increase in the drainability of the pulp slurry, which may increase the rate of papermaking. Although endoglucanase activity also enhances certain pulp properties, there was little benefit in adding it to the xylanase treatment., (Copyright 2004 Wiley Periodicals, Inc.)

Laser‐induced graphene (LIG) produced by irradiation of paper (paper‐LIG)holds substantial promise for flexible devices. This article presents paper‐LIG humidity and temperature sensors fabricated by single‐step irradiation of common filter paper with a pulsed UV laser (355 nm). The influence of the process parameters on the conversion of cellulose fibers into LIG is discussed based on the resulting morphology, structure, conductivity, and chemical composition, revealing a distinct barrier to transformation and a propagation behavior not seen under CO2 laser irradiation. The obtained material is constituted by a porous, electrically conductive network of fibers. The paper‐LIG relative humidity (RH) and temperature sensors with sensitivities of up to 1.3 × 10−3%RH−1 and ‐ 2.8 × 10−3 °C−1, respectively, are examined in terms of their linearity, reproducibility, and response time. A detailed discussion on the response mechanism is presented in the context of literature, pointing towards the absorption of water molecules in the interlayer spacing of graphene as the main reason for the increase in resistance with RH. Additionally, a contribution from variable range hopping along the ab plane of graphene at high RH is suggested. These results demonstrate the potential of paper‐LIG for low‐cost, sustainable, and environmentally friendly sensing. [ABSTRACT FROM AUTHOR]

Aims: The purpose of this study was to evaluate the effects of ambient or altered environmental conditions on the inactivation of SARS‐CoV‐2 applied to materials common in libraries, archives and museums. Methods and Results: Porous and non‐porous materials (e.g. paper, plastic protective book cover) were inoculated with approximately 1 × 105 TCID50 SARS CoV‐2 (USA‐WA1/2020), dried, placed within test chamber in either a stacked or unstacked configuration, and exposed to environmental conditions ranging from 4 to 29°C at 40 ± 10% relative humidity. The amount of infectious SARS‐CoV‐2 was then assessed at various timepoints from 0 to 10 days. Ambient conditions resulted in varying inactivation rates per material type. Virus inactivation rate decreased when materials were stacked or at colder temperatures. Virus inactivation rate increased when materials were unstacked or at warmer temperatures. Conclusions: SARS‐CoV‐2 at ambient conditions resulted in the inactivation of virus below limit of quantitation (LOQ) for all materials by Day 8. Warmer temperatures, for a subset of materials, increased SARS‐CoV‐2 inactivation, and all were

Paper and cardboard elements can be used as a pro-ecological building material. To meet the safety and usage requirements paper elements need to be impregnated, however, most impregnation methods have a negative impact on the environmental performance of the elements. This article describes research that was conducted in order to determine the most effective technique of paperboard impregnation against water and humidity. Particular attention was given to biodegradable coatings, as several oil-based and wax-based wood impregnates were used. The samples were tested for 24 hours in immersion and for 48 hours in high air humidity. Water uptake (measured by the change in mass and thickness), delamination and deformation of samples were monitored. As a result, the basic characteristic of the tested impregnation methods was established – water and water vapour absorption, deformation or delamination after immersion. The lowest water and water vapour absorption was observed in samples impregnated with composed coatings of oils and waxes. [ABSTRACT FROM AUTHOR]

Paper flowers are frequently, for example as indoor decorations and in wedding bouquets. But these traditional paper flowers can only maintain static conditions, greatly affecting their sensory effects, vividness, and appreciation. The design of novel paper flowers with dynamic shape deformation could effectively broaden the application of paper flowers. Here, inspired by Chinese calligraphy, a novel polyvinyl butyral (PVB)/carbon/cellulose composite (PCC) magic paper with a sandwiched structure is prepared. The hygroscopicity difference between hydrophobic PVB and hydrophilic cellulose layer endows the PCC paper with humidity responsiveness, and the maximum bending angle is up to 91.4° upon exposure to humidity environment. Carbon in the interlayer with strong light–heat conversion capacity could further accelerate water desorption and deformation speed, resulting in highly sensitive light responsiveness. The recovery time of PCC paper from maximum bending to the original flat state is shorter than 1 s. The PCC paper has good flexibility and processability, which can be cut and assembled into flowers with different shapes, and these unique magic flowers could freely bloom and furl upon external stimulus. All these results indicate that PCC paper has great potential in the production of magic props, artworks, and intelligent household decorations fields. [ABSTRACT FROM AUTHOR]

Moisture absorption in the cell wall structure of wood is well known to induce considerable swelling of the wood exerting high expansion forces. This swelling is mainly induced by the sorptive action of the hydroxyl groups of the carbohydrate wood polymers; cellulose and hemicelluloses. On the ultrastructural level, there are, however, still questions with regard to the detailed deformations induced by this moisture absorption. Here, FTIR spectroscopy and synchrotron-radiation-based X-ray diffraction were used on paper samples to study the deformation of the cellulose crystals as a consequence of moisture absorption and desorption. Both techniques revealed that the moisture absorption resulted in a transverse contraction of the cellulose crystals accompanied by a somewhat smaller elongation in the cellulose chain direction. The deformations were found to be a direct response to the increased moisture content and were also found to be reversible during moisture desorption. It is hypothesised that these deformations are a consequence of the swelling forces created by the combined longitudinal and lateral expansions of the non-crystalline cellulose molecules and the glucomannan hemicellulose aligned along the cellulose crystals. These forces will impose a lateral contraction of the cellulose crystals, as well as a longitudinal extension of it. [ABSTRACT FROM AUTHOR]

In paper containing multilayer composite structures and laminates, polarization is usually investigated under dry environmental conditions. The aim of this research is to determine polarization dependence of paper and paper-dielectric structures on environmental relative humidity (RH). The role of each component was identified. The obtained and recorded data are used for identification and clarification of the physical mechanism of polarization. The polarization was studied by applying a dosed charging and forced discharge method and was evaluated by a depolarization potential and its formation kinetics. The polarization level of investigated structures increases with RH and is determined mainly by the paper (cellulose) and moisture content in it. In composite structures of the paper between dielectric films and dielectric on paper the polarization dependence on RH correlates with moisture absorption isotherm. It was found that the surface electrical conductivity of paper distorts the results of the paper and structure paper on dielectric. Analysis of the formation kinetics of the depolarization potential together with the potential decay of the charged paper has determined the role of orientation polarization and space charges. The formation of space charges is faster than orientation polarization and dominates in polarization process at higher RH. The process modeling by superposition of two exponents confirms this polarization mechanism. [ABSTRACT FROM AUTHOR]

There is an increasing demand for measuring respiratory rate (RR) to monitor the progression of clinical events such as cardiac arrest or during the admission to the intensive care unit (ICU). Current methods of respiration monitoring are complex, invasive, expensive and therefore require alternative techniques. In this paper, we utilized wearable and flexible technology to develop humidity sensors for long-term continuous monitoring of respiration. Using manual drawing and printing techniques, the sensors were made based on graphite trace and silver nanoparticles as two different sensing materials. The surface morphologies of the devices were characterized by Scanning Electron Microscope (SEM) to show the construction of the sensors. Additionally, the material characterization was performed to obtain the Raman Spectra. Paper was chosen as a flexible substrate owing to its biodegradability, porosity, and disposability. The humidity sensing characteristics of the sensors indicated the best sensitivity of 0.0564% for Graphite on Paper (GOP) sensor. Furthermore, the hygroscopic nature of the paper enables converting the humidity changes during inhalation and exhalation into electrical signals. The electrical signals are transmitted via an interface to a computer using a simple data-logging set-up. A set of normal, deep and apnea breathing conditions could be easily differentiated from these signals along with information on respiration rate and pattern. The functionality of sensors was also tested after light and rigorous exercises. The proposed sensor combines the advantages of being low cost, non-invasive, highly sensitive, stable and holds tremendous potential for wearable/flexible healthcare technology. [ABSTRACT FROM AUTHOR]

The use of papers as substrates in the process of manufacturing flexible electronic components is urgently required to obtain cost-effective products as well as to expand the potential applications of such components. This study aimed to examine the suitability of three different types of paper for sensor applications using an inkjet printing process. Three types of paper (denoted as Types 1, 2, and 3) designed for specific applications in printed electronics were selected and entirely characterized in terms of microscopic and macroscopic properties, such as internal fibers structure, cross-sectional layer structure, surface roughness, and hardness. Dot arrays were printed on these three types of paper to determine how the papers absorb silver ink and which one is the best substrate for manufacturing printed electronic components. After a comprehensive analysis, the paper that exhibited the best feature was further studied as a substrate for printing interdigitated electrodes to develop a humidity sensor. The Type 2 paper-based sensor demonstrated the variation in capacitance in the range from 9.4 to 10.6 pF while changing the relative humidity (RH) from 40 to 90%. Thus, Type 2 has the great potential for application in flexible sensors, suggesting the possibility of industrial scalability and mass production of inexpensive, biodegradable, and conformable electronic components. [ABSTRACT FROM AUTHOR]

Wireless, passive, and cost-efficient monitoring of moisture within packaged food and medicine is important to ensure their safety and freshness. This paper presents paper-based single spiral inductance–capacitance (LC) sensors and a distance-insensitive readout system. The parasitic capacitance of the single-spiral coil is used to form an LC resonant circuit with its inductance. The printing paper is utilized as a humidity sensing material. A model for the LC sensor is analyzed and compared with HFSS simulation, showing the relative error within 6.3%. Nano-silver paste for the single-spiral coil was screen printed on the printing paper. The LC sensors with 4, 6, and 8-turns coils were characterized at relative humidity levels of 15%-90%RH by a readout coil at a fixed position. Comparison shows that the 8-turn sensor has the best linearity with respect to humidity. The sensitivity and response time were measured to be 120 kHz/%RH and 60 minutes, respectively, with the hysteresis errors less than 0.9%. During the practical monitoring, the tested signal frequency will have a shift if the coil’s relative position alters. To weaken the influence of the coil’s position, a readout coil, working at the quasi-resonant with the LC sensor was utilized to enhance the readout, resulting in more stable signal. According to the experimental results, the improved readout system can restrain the frequency shift within 1.1% at a readout distance from 2–50 mm when the ambient humidity is 60%RH. [ABSTRACT FROM AUTHOR]

Since hydrophobicity can improve the usability and functionality of materials in humid condition, enhancing the hydrophobic behavior of starch films or papers is of importance. In this work, ZnO nanoparticles (NPs) were introduced into the starch solution under ultrasonic and magnetic-stirring, followed by cast filming and paper coating. The contact angles of resulting film and coated paper containing 2% (wt) NPs were increased from 85.73° to 121.45°, 64.47° to 103.94°, respectively. The results from comprehensive characterizations confirmed the hierarchical structure created by ZnO nanoparticles on the surface of starch film as well as the formation of intact layers on coated paper. The excellent miscibility between starch and ZnO NPs was also achieved. The approach developed is promising and facilitates the hydrophobic modification of green-based materials. [ABSTRACT FROM AUTHOR]

• Preparation of dual functional humidity humidity-sensitive paper using sustainable nanoclay and beeswax. • Increment of actuation degree up to 110° (30 %RH) from 40° (90 %RH). • Able to detect humidity from changes in electrical resistances (150-700kΩ). A highly humidity-responsive paper can detect moisture or OH-attached molecules at the sub-micron or nano level range. Applying hydrophilic nanoclay as an active material for water sensing would reduce the fabrication cost while remaining environmentally friendly. In this communication, we report the preparation of a nanoclay-inspired dual-responsive smart film that can signal humidity levels from mechanical and electrical responses. The paper will bend as the nanoclay layer swells whereas the resulting bending strain will trigger the electrical resistance changes in the hydrophobic electrically conductive graphite-beeswax layer. [ABSTRACT FROM AUTHOR]

This paper addresses one of the key issues in using paper electronics at microwave frequencies. As paper is hygroscopic, the varying moisture content can lead to differing dielectric and even conductive properties of paper electronics and must be taken into consideration in any device design. In this work, coplanar waveguides (CPWs) have been screen printed using silver ink on matt paper. Increasing the relative humidity between 40 and 90% is shown to increase the losses, decrease the propagation velocity and decrease the characteristic impedance of CPWs. The effect of water on both silver flake ink and the matt paper used in this work are considered, and it is shown that the change in permittivity of the substrate as a result of absorbed water within paper is the most dominant factor on the microwave characteristics. The reported findings should be considered in paper‐based applications at microwave frequencies, as the changes in transmission‐line parameters can lead to drastic variations in device and system operation. [ABSTRACT FROM AUTHOR]

Cellulosic materials are highly sensitive towards environmental changes such as temperature and especially towards humidity. Besides morphological changes like swelling and/or shrinking, the mechanical properties of pulp fibres and fibre to fibre joints change as well. The current study sets to elucidate the changes and the extent to which elevated or decreased relative humidity (RH) influences the load bearing capacity of individual hardwood and softwood fibres and joints. The device used for the measurements is a micro bond tester with a custombuilt humidity chamber in which the humidity can be controlled in a range from 25 to 95% RH. Individual fibres and joints have been tested at 30, 50 and 80% RH after equilibration time of 120 min. The breaking load of individual softwood fibres and joints displayed a maximum breaking load at 50% RH, with the values showing a decreasing trend towards higher or lower RH. In case of hardwoods, no change in the breaking load of either individual fibres or fibre to fibre joints has been observed at different RH. [ABSTRACT FROM AUTHOR]

The article analyses the effects of paper moisture content on energy absorbed during its tensile testing in the range of moisture equilibrium obtained during paper air conditioning at a temperature of 23 °C. To predict changes in breaking energy caused by changes in moisture content, two calculation methods were proposed. The methods were verified on the basis of laboratory tests and calculation results, and their practical usefulness was confirmed. [ABSTRACT FROM AUTHOR]

Much research has been focused on maintaining stable humidity conditions in buildings housing heritage collections while reducing energy use. Moisture buffering by collections themselves can have a marked effect on the stabilisation of relative humidity (RH), the key parameter for preservation. Modelling of moisture transport using COMSOL Multiphysics was applied to transform three-dimensional paper and wooden objects into their one-dimensional representations, without changing the moisture uptake and release characteristics. The results were coupled to the modelling of indoor microclimate and energy consumption in collection storage spaces with the use of WUFI ® Plus software. The study revealed the crucial impact of air exchange rate of the building on the stability of indoor RH and the humidification and dehumidification loads required to maintain it. In the adequately air-tight library store, a sizeable paper collection was found to reduce the RH fluctuations from ±9% to ±6% around the yearly average and the energy consumption due to the humidification and dehumidification load by 38% when compared with the empty space, for a high-quality climate control scenario. In turn, a wooden collection, occupying a realistic fraction of a museum store was not large enough to significantly narrow down the RH variations and reduce the energy consumption. [ABSTRACT FROM AUTHOR]

An inkjet-printed relative humidity sensor based on capacitive changes which responds to different humidity levels in the environment is presented in this work. The inkjet-printed silver interdigitated electrodes configuration on the paper substrate allowed for the fabrication of a functional proof-of-concept of the relative humidity sensor, by using the paper itself as a sensing material. The sensor sensitivity in terms of relative humidity changes was calculated to be around 2 pF/RH %. The response time against different temperature steps from 3 to 85°C was fairly constant (about 4-5 min), and it was considered fast for the aimed application, a smart label. [ABSTRACT FROM AUTHOR]

The article focuses on the use of design of experiment (DoE) approach for photographs and paper works which may get damaged by the environmental changes. It discusses the need for controlling the environmental factors like relative humidity (RH) and temperature, how the research information gathered have made it possible to recommend materials for framing of photographs and paper in museum collection. It also talks about the use of Mavelseal, which can help to reduce the humidity fluctuations with marginal costs.

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Iron gall ink was the most widely used writing ink for paper from the Middle Ages to the twentieth century. Unfortunately, the ink ingredients contain corrosive transition metal ions and acids that cause severe damage to the paper carrier. New or improved paper conservation methods for iron gall ink stabilization are constantly sought. The aim of the study was evaluation of a recently proposed stabilization treatment, adapted to lower relative humidity, applied to various model and historical paper samples containing iron gall ink. The effect of stabilization treatment on paper samples during artificial thermal aging was followed by the determination of the molecular weight distribution by size exclusion chromatography and colorimetry. Migration of iron and copper compounds from the ink lines was monitored by laser ablation inductively coupled plasma mass spectrometry. The results demonstrate that effective stabilization of iron gall ink-containing paper can be successfully achieved by interleaving with papers impregnated with the antioxidant tetrabutylammonium bromide and alkaline buffer under experimental conditions. Negative side effects of the stabilization treatment, such as migration of iron or copper ions from the ink lines and changes of color after the treatment and after accelerated thermal degradation, were limited, proving that the proposed stabilization treatment can be considered for future use by conservators. [ABSTRACT FROM AUTHOR]

Thin inkjet-printed tracks of silver nanoparticles have previously been observed to show a non-reversible decrease in resistance when exposed to a high degree of relative humidity and thus providing sensor functionality with a memory effect. This paper provides a more in-depth explanation of the observed humidity sensor effect that originates from inkjet-printed silver nanoparticle sensors on a paper substrate. It is shown that the geometry of the sensor has a large effect on the sensor's initial resistance, and therefore also on the sensor's resistive dynamic range. The importance of the sensor geometry is believed to be due to the amount of solvent from the ink interacting with the coating of the paper substrate, which in turn enables the diffusion of salts from the paper coating into the ink and thus affecting the silver ink. [ABSTRACT FROM PUBLISHER]

This paper is aimed at the study of aging behavior of cellulosic materials in different dielectric liquids under air and nitrogen atmospheres. Paper for copper conductor and high density transformer board were aged at 130°C up to 1128 h in sealed vessels in presence of mineral oil (MO), natural ester (VO) and synthetic ester (SE). The influence of thermal aging on cellulose and oil characteristics are investigated and compared. It's observed that the paper degradation is associated with the generation of CO2 and CO gases. Whatever the type of oil, this generation is more important with vessel under air atmosphere than that under nitrogen gap indicating a protective effect of nitrogen. In mineral oil, the degree of polymerization (DPv) reaches the end of life criteria at around 200 whereas it remains around 400 with ester oils. This is mainly due to the higher water solubility of esters compared to mineral oil. The measured degree of polymerization in MO is comparable to that calculated through 2-FAL (Furanic compounds) content using Vuarchex equation whereas for esters oil, there is no agreement between the measured and calculated DPv through 2-FAL content. This can constitute a limitation in the use of 2-FAL for the diagnosis of ester-filled transformers. Overall, the insulation cellulose/oil behavior seems better under nitrogen atmosphere. [ABSTRACT FROM PUBLISHER]

Abstract: In this work we present a mathematical model describing the coupled heat and moisture transport in paper. The model is solved numerically and the numerical solution is used to study the interdependency of the moisture and temperature distribution in paper. The results show that variation with temperature of the saturated water vapor concentration and the sorption isotherm parameters are both important for inducing moisture desorption. It is also found that for steep relative humidity ramps moisture sorption generates temperature increments that slow down the sorption process itself. The model is also used to study the moisture gradients in a paper sheet inside a printer from Océ Technologies, which contains a warm print surface. The results predict changes in moisture content of only 0.2%, which suggests that no deformations are induced on the printed sheet. [Copyright &y& Elsevier]

Abstract: In certain conditions, iron gall inks induce substantial damages on cellulosic supports. Existing curative treatments necessitate the immersion of the documents in aqueous solutions. This implies several undesirable side effects: mechanical stress of the most damaged papers, substantial colour changes, and a drastic modification of the paper/ink composition. This work investigated an alternative treatment that consists in compressing the document between two interleaves that are charged with active compounds. When this operation is operated in moist conditions, active compounds may migrate from the interleaves to the document, and thus achieve the treatment of the paper. As high humidity conditions may additionally induce some migration of iron and acidic compounds out of the ink line, it first appeared necessary to research humidity conditions which minimize these undesirable migrations. This investigation was performed on a set of 53 original manuscripts and led us to consider that a relative humidity of 80% was quite reasonable. The second part of the paper deals with the evaluation of interleaving treatment efficiency. It was performed on laboratory samples, using several types of antioxidant halide salts (NaCl, NaBr, CaBr2) (halides are known to act as radical scavengers). These compounds were tested separately or in combination with calcium carbonate as an alkaline buffer. The samples were made of Whatman paper that was preliminary impregnated with iron gall ink. It has shown that a charge of 2% calcium carbonate in the interleaves has no impact on the treatment efficiency, which mainly depends upon the concentration of salts, the contact pressure and the duration of the treatment. Elemental measurements show that the mobility of the salts is much higher than that of iron, suggesting the possibility to find optimum treatment conditions that minimize the iron migration risk while achieving an effective migration of halides. [Copyright &y& Elsevier]

The influence of temperature and relative humidity on the moisture content of paper honeycomb sandwich panels was studied, and the ideal three-dimensional diagram between the moisture content of paper honeycomb sandwich panels and the temperature and relative humidity was constructed by the GAB model. The evaluation equation of critical stress and plateau stress were obtained. The results indicate that the moisture content of paper honeycomb sandwich panels rises with the increase of relative humidity and declines with the increase of temperature; as the moisture content increases, the critical stress and plateau stress of paper honeycomb sandwich panels decline linearly; with the increase of the moisture content, the energy absorption of paper honeycomb sandwich panels increased firstly and then decreased; the evaluation equation of critical stress and plateau stress can predict the mechanical properties of paper honeycomb sandwich panels in different temperatures and relative humidities. [ABSTRACT FROM AUTHOR]

In this paper, the design and the manufacture of an inkjet printed resistive type humidity sensor on paper are reported. After having been exposed to humidity above a given threshold level, the resistance of the sensor decreases substantially and remains at that level even when the humidity is reduced. It is possible to deduce the humidity level by monitoring the resistance. The main benefit of the printed sensor presented in this case is in relation to its very low production costs. It has also been shown that both the ink type and this paper combination used prove to be crucial in order to obtain the desired sensor effect. More research is required in order to fully understand the humidity sintering effect on the nano particle ink and the role of the substrate. However, the observed effect can be put to use in printed humidity sensors which possess a memory function. The sensor can be used in various applications for environmental monitoring, for example, in situations where a large number of inexpensive and disposable humidity sensors are required which are able to detect whether they have been subjected to high humidity. This could be the checking of transportation conditions of goods or monitoring humidity within buildings. [ABSTRACT FROM PUBLISHER]

Abstract: This paper estimates the effects of humidity and temperature on mortality rates in the United States (c. 1973–2002) in order to provide an insight into the potential health impacts of climate change. I find that humidity, like temperature, is an important determinant of mortality. Coupled with Hadley CM3 climate-change predictions, I project that mortality rates are likely to change little on the aggregate for the United States. However, distributional impacts matter: mortality rates are likely to decline in cold and dry areas, but increase in hot and humid areas. Further, accounting for humidity has important implications for evaluating these distributional effects. [Copyright &y& Elsevier]

Impact of maintenance conditions upon the paper resistance was investigated. Dependencies of tensile strength and resistance to bending of different paper type on paper fibers direction and humidity were presented. [ABSTRACT FROM AUTHOR]

Adhesion issues are present in many disciplines such as, for example, surface science, microrobotics or MEMS design. Within this framework, this paper presents a study on capillary forces due to capillary condensation. A simulation tool had already been presented using Surface Evolver and Matlab to compute the shape of a meniscus in accordance with the Kelvin equation and contact angles. The numerical results of this simulation complied well with literature results. One very important result is the ability to compute the evolution of the capillary force depending on the tilt angle of the gripper with respect to the object. The main contribution of this new paper is a test bench and the related experimental results which validate these numerical results. We present here new experimental results illustrating the role of humidity and tilt angle in capillary forces at the nanoscale. [ABSTRACT FROM AUTHOR]

Abstract: A dosed charging–discharging method was applied to an investigation of the paper charging properties which may be important in toner transfer in electrophotographic printers and copiers. This investigation method, which is new for paper substrates, made it possible to reveal some characteristics of paper charging and discharging processes: the dependence of charge acceptance on charging intensity, which is different for coated and uncoated papers, the change in paper charging properties during charging, unconventional charge acceptance and potential decay dependence on thickness at higher relative humidity, and the role of paper polarization in the discharge of paper. [Copyright &y& Elsevier]

Abstract: The damage to historical documents and books caused by the acidic character of paper is often manifested as a complete loss of their mechanical properties. Deacidification and restoration of archived paper objects require knowledge of the long-term behaviour of paper before and after repair actions. Our study was focused on the investigation of mechanical properties (tensile strength, stretch, tensile index, zero-span tensile strength, folding endurance) of original papers (one alkaline and three different acidic samples) exposed to five methods of dry-heat and moist-heat accelerated ageing. The degree of paper deterioration upon ageing was significantly influenced by the temperature and relative humidity, along with the intrinsic chemistry of the individual paper samples. The correlation matrix evaluated at a 95% confidence level for tensile strength, stretch, tensile index and zero-span showed linear correlations between these mechanical properties for all the paper samples. However, a linear dependence of folding endurance on zero-span tensile strength was found only for alkaline paper, which revealed the highest resistance to the accelerated ageing tests. In addition, the concentration of paramagnetic semiquinone species in the acidic lignin-containing paper samples was monitored by Electron paramagnetic resonance spectroscopy. [Copyright &y& Elsevier]

Abstract: The objective of this work was to compare and understand the aroma compound barrier property of two impregnated–supercalendered papers, with or without surface coating, and one plastic film (BOPP) in standard conditions of temperature (25°C) and relative humidity gradient (50%) for foodstuff storage. For that purpose, solubility, diffusivity and permeability coefficients were determined for a homologous series of ethyl esters with a range of physico-chemical properties and vapor concentrations. Whatever the aroma compound and its vapor concentration, the non-coated paper was the more permeable; the coated paper and BOPP presenting close and lower permeability values. The transfer behavior was mainly controlled by aroma compound diffusivity related to packaging microstructure. Mutual affinity between aroma compound and packaging surface, determined experimentally or estimated, was related to their respective hydrophobicity. Conversely to papers which were treated to become more hydrophobic, BOPP was surface-treated to become more hydrophilic. In the conditions of the study, ethyl hexanoate sorption slightly increased BOPP crystallinity. [Copyright &y& Elsevier]

Abstract Measurements have been performed to clarify the connection between fibre–fibre joint properties and dimensional stability using laboratory sheets prepared from never-dried fibres, from heavily hornified fibres having a low molecular contact area between the fibres, and from both hornified and never-dried fibres treated with a polyelectrolyte multilayer (PEM) technique to increase the molecular contact area in the fibre–fibre joint. The influence of the drying mode, i.e. whether the sheets are dried freely or under restraint, was also evaluated. The results showed that neither paper strength nor fibre–fibre joint contact area had any significant influence on the dimensional stability of sheets dried under restraint. On the other hand, when the sheets were dried freely, the PEM-treated sheets expanded to the same extent as, or to an even greater extent than the non-PEM-treated sheets, even though they adsorbed less water for a given change in relative humidity. There was also a correlation between drying shrinkage and dimensional stability, where greater shrinkage was associated with a greater hygroexpansion in the freely dried sheets. [ABSTRACT FROM AUTHOR]

Abstract: The creep of paper is accelerated by moisture cycling, an effect known as mechano-sorptive creep. It has also been observed that the mechano-sorptive effects are larger in compression than in tension. In this paper a simplified network model for mechano-sorptive creep is presented. It is assumed that the anisotropic hygroexpansion of the fibres leads to large stresses at the fibre–fibre bonds when the moisture content changes. The resulting stress state will accelerate creep if the fibre material obeys constitutive laws that are non-linear in stress. Geometrical fibre effects are included in the model in order to capture experimental observations of the differences between paper loaded in tension and compression. Theoretical predictions based on the developed model are compared to experimental results for paper both under tensile and compressive loading at varying moisture content. The important features in the experiments are captured by the model, i.e. the creep is accelerated by the moisture cycling and the mechano-sorptive effects are larger in compression than in tension. [Copyright &y& Elsevier]

Abstract?? In order to investigate the way in which fibre properties affect the mechano-sorptive creep phenomenon in paper, single wood fibres were exposed to tensile stresses at a constant humidity of 80% relative humidity (RH) and in a cyclic humidity environment varying between 80 and 30% RH. Contrary to earlier claims, it was demonstrated that single wood fibres exposed to a cyclic RH show a considerably higher creep than that corresponding to the highest RH experienced in the cycle, i.e., a mechano-sorptive behaviour. The creep strain rate at cyclic humidity was shown to be a function of the creep rate at constant climate, and to be an apparent linear function of the applied stress. [ABSTRACT FROM AUTHOR]

The wide-line 1H nuclear magnetic resonance (NMR) spectrum of paper in equilibrium with ambient humidity consists of super-imposed relatively broad and narrow lines. The narrower line is of the order of 2 kHz wide at half the maximum height, while the broader line is of the order of 40 kHz in width at half height. On the basis of these line widths, the narrow line is assigned to water sorbed to the paper, and the broad line to the polymeric constituents of the paper. It was not possible to distinguish between the various polymeric components of paper contributing to the 1H NMR spectra. A modified Goldman-Shen pulse sequence was used to generate a spatial magnetisation gradient between the polymer and water phases. The exchange of magnetisation between protons associated with water and those associated with the macromolecules in paper was observed. The exchange of magnetisation is discussed within a heat transfer model for homonuclear dipolar coupling, with exchange being characterised by a spin-diffusion coefficient. Consideration of the magnitude of the initial rate of the exchange process and estimates of the spin-spin relaxation times based on 1H line widths indicate that some water must exist in a sufficiently immobile state as to allow homonuclear dipolar interactions between adjacent polymer and water protons. Thus, water sorbed onto paper must exist in at least two states in mass exchange with each other. This observation allows certain conclusions to be drawn about the ratio of free/bound water as a function of moisture content and the dispersal of water within the polymer matrix. [ABSTRACT FROM AUTHOR]