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Indonesian municipal solid waste (MSW) is dominated by biodegradable MSW (organic and paper). Due to the degradation process, the physical and hydraulic characteristics of these components can change. It is important to study the physical and hydraulic characteristics of MSW, because landslides occurred in several landfills in Indonesia after heavy rains. Field observations showed that landslides occur due to reduced paper components in the landfill (due to high recycling activities), and cause high percolation of water into the landfill. In the research, 38 samples consisting of two variants of MSW samples (organic and 80% organic + 20% paper), were prepared under the conditions of optimum moisture content. The organic sample of MSW is leaf, while the paper sample of MSW is newspaper, which were shredded to a diameter of about 1 cm. The tests of moisture content, bulk density (in the mould of permeameter), particle size distribution, and permeability were carried out on both sample variants for 90 days, with a test frequency of once in 5 days. The results showed that there was an increase in the moisture content and density, and a decrease in particle size and permeability in both variants of MSW sample. Organic MSW + paper has lower permeability and higher density than organic MSW. This requires further study, because a high paper recycling ratio can lead to a change in the landfill characteristics.

A functional biopolymer-coated paper was prepared by coating a ternary blend of the alginate, carboxymethyl cellulose, and carrageenan with grapefruit seed extract (GSE) for the substitute use of synthetic polymer-coated paper. The microstructure of the surface and cross-section of the coated paper analyzed by field emission scanning electron microscope (FE-SEM) indicated that the biopolymer was compatible with the base paper and filled the pores of the porous fiber to make a smooth-surfaced coating paper. The properties of the biopolymer-coated paper, such as water and oil resistance, water vapor barrier, surface hydrophobicity, and mechanical properties, increased significantly compared with not only the base paper but also commercially used PE-coated paper. The blended biopolymer coating material exhibited strong antibacterial activity against food-borne pathogenic bacteria, Listeria monocytogenes and Escherichia coli, which were destroyed completely within 3 and 9 h, respectively. The packaging test for a minced fish cake packed with the biopolymer-coated paper showed the complete destruction of surface inoculated bacteria in 6–9 days. The biopolymer-coated paper showed a high potential for disposable food packaging applications to increase the shelf-life of packaged food.

Paper-based packaging generally has poor performances in the gas/oil barriers. This work reports a paper-based packaging material prepared via the modification of conventional papers with TEMPO-oxidized cellulose nanofibers (TOCN)/cationic guar gum (CGG) hydrogel film. Specifically, the hydrogel film modification was realized through a layer-by-layer deposition on paper. The hydrogel film modification significantly improved the mechanical and barrier properties of the paper. Specifically, the 4-layer hydrogel film modified paper showed a tensile strength of 34.03 MPa and a burst strength of 510 kPa, respectively. In contrast, the unmodified paper exhibited a tensile strength of 26.78 MPa and a bursting strength of 388 kPa. The packaging performance of this TOCN/CGG hydrogel film modified paper was demonstrated via the fresh mooncake packaging test. Such hydrogel film not only provided the oil resistance, but also maintained the mooncake's freshness. This material can serve as a green and sustainable food packaging.

The results found in the literature concerning the effect of consuming filter coffee brews on increasing the blood cholesterol levels due to the presence of diterpenes, are divergent. Thus the present research evaluated the diterpene (cafestol and kahweol) concentrations in filter coffee brews prepared with paper filters of different sizes, colors and origins (Brazil, Japan, The United States of America, Germany, France and the Netherlands), with and without micro perforations. This is the first study that reports the physical characteristics of paper filter and its importance to obtain filter coffee brew with low cafestol content. Thus, a sample of Catuai cultivar coffee with high cafestol content was roasted to a medium-light degree and used to prepare the brews in a 1:10 ratio (coffee powder to water). The diterpenes were extracted by direct saponification and quantified and identified by HPLC-DAD-MS/MS. The paper filters were physically characterized by measuring their grammage, and the fat permeation rate calculated in order to better understand the differences between the filters which allow one to obtain higher or lower diterpene contents. The cafestol and kahweol concentrations in the brews varied from 1.62 to 2.98 mg/L and from 0.73 to 1.96 mg/L, respectively. The highest cafestol and kahweol concentrations were obtained using paper filters with micro perforations, considering similar sized paper filters. The paper filters showed high fat permeability and grammages between 50.46 and 67.48 g/m2. The diterpene retention capacities of the filters produced in the different countries were similar. The results showed that the porosity of the paper filter and the particle size of the ground roasted coffee were determinant factors in obtaining filter coffee brews with lower cafestol contents.

This work describes a 3D, paper-based assay that can isolate sub-populations of cells based on their invasiveness (i.e., distance migrated in a hydrogel) in a gradient of concentration of oxygen (O2). Layers of paper impregnated with a cell-compatible hydrogel are stacked and placed in a plastic holder to form the invasion assay. In most assays, the stack comprises a single layer of paper containing mammalian cells suspended in a hydrogel, sandwiched between multiple layers of paper containing only hydrogel. Cells in the stack consume and produce small molecules; these molecules diffuse throughout the stack to generate gradients in the stack, and between the stack and the bulk culture medium. Placing the cell-containing layer in different positions of the stack, or modifying the permeability of the holder to oxygen or proteins, alters the profile of the gradients within the stack. Physically separating the layers after culture isolates sub-populations of cells that migrated different distances, and enables their subsequent analysis or culture. Using this system, three independent cell lines derived from A549 cancer cells are shown to produce distinguishable migration behavior in a gradient of oxygen. This result is the first experimental demonstration that oxygen acts as a chemoattractant for cancer cells.

Herein we utilized the filter paper to physically trap red blood cells (RBC) to observe the breathing process of red blood cells based on the permeability of the filter paper. By integrating double-sided conductive carbon tape as the working electrodes, the device could be applied to monitor electrochemical responses of RBC for up to hundreds of minutes. The differential pulse voltammetry (DPV) peak currents increased under oxygen while decreased under nitrogen, indicating that RBC could take in and release oxygen. Further studies demonstrated that the RBC suspension could more effectively take in oxygen than the solution of hemoglobin and the supernatant of RBC, suggesting the natural advantage of RBC on oxygen transportation. This study implied that simple paper-based analytical devices might be effectively applied in the study of gas-participating reactions and biochemical detections.

In cigarette production, the cellulosic paper essentially derived from flax fibers or other fiber materials is used as the wrapping material. During smoking of cigarettes, the highly toxic carbon monoxide is produced. To decrease the amount of carbon monoxide emission in the mainstream smoke, the engineering of all cigarette components including cellulosic cigarette paper and tobacco column is critical. This review summarizes the concepts related to engineering of cigarette paper. These mainly include permeability control, increased use of burn additives, optimization of fiber basis weight, engineering of calcium carbonate fillers, and incorporation of catalysts/oxidants. In particular, catalytic and/or oxidative conversion of carbon monoxide to carbon dioxide has been very widely reported. The control of permeability/diffusivity of cigarette paper is also of critical importance for enhanced diffusion of carbon monoxide out of the cigarette. The development of new concepts and combination of various concepts may lead to breakthroughs in this area.

Culturing cells at the air–liquid interface (ALI) is essential for creating functional in vitro models of lung tissues. We present the use of direct-patterned laser-treated hydrophobic paper as an effective semi-permeable membrane, ideal for ALI cell culture. The surface properties of the paper are modified through a selective CO2 laser-assisted treatment to create a unique porous substrate with hydrophilic regions that regulate fluid diffusion and cell attachment. To select the appropriate model, four promising hydrophobic films were compared with each other in terms of gas permeability and long-term strength in an aqueous environment (wet-strength). Among the investigated substrates, parchment paper showed the fastest rate of oxygen permeability (3 times more than conventional transwell cell culture membranes), with the least variation in its dry and wet tensile strengths (124 MPa and 58 MPa, remaining unchanged after 7 days of submersion in PBS).The final paper-based platform provides an ideal, robust, and inexpensive device for generating monolayers of lung epithelial cells on-chip in a high-throughput fashion for disease modelling and in vitro drug testing.

A novel integrated thermophilic submerged aerobic membrane bioreactor (TSAMBR) and electrochemical oxidation (EO) technology was developed for thermomechanical pulping pressate treatment with the aim of system closure. The TSAMBR was able to achieve a chemical oxygen demand (COD) removal efficiency of 88.6 ± 1.9-92.3 ± 0.7% under the organic loading rate of 2.76 ± 0.13-3.98 ± 0.23 kg COD/(m(3) d). An optimal hydraulic retention time (HRT) of 1.1 ± 0.1d was identified for COD removal. Cake formation was identified as the dominant mechanism of membrane fouling. The EO of the TSAMBR permeate was performed using a Ti/SnO(2)-Sb(2)O(5)-IrO(2) electrode. After 6-h EO, a complete decolourization was achieved and the COD removal efficiency was increased to 96.2 ± 1.2-98.2 ± 0.3%. The high-quality effluent produced by the TSAMBR-EO system can be reused as process water for system closure in pulp and paper mill.

Introduction of an enzyme and a colour-forming reagent into paper enables the development of an authenticity indicator. The purpose of this work was to study the performance of Trametes versicolor laccase, TvL, and ABTS, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt, in various printing substrates when printed with inkjet. The printing substrates included pre-coated mechanical paper additionally coated with PVA, silica and latex. The focus was on the bioanalytical performance and ink penetration. The setting of the printed TvL and ABTS ink was studied visually, with optical and confocal microscopy and with a so-called tape laminating technique. Technical properties of the printing substrates and effect of the surface chemistry were discussed and related to the bioanalytical properties.TvL activity persisted well during the printing. The best colour response was attained using the PVA-coated base paper. The film-forming ability of the PVA was found to be the main contributor to the colour reaction. The uniform, dense and non-porous PVA layer retains the ABTS and TVL molecules on top of the printing substrate. The high local ink concentration on the PVA coating layer combined with the absorptive paper substrate suggests that the PVA film acts as a filtering layer which retains TvL and ABTS molecules in the coating layer but allows most of the ink solvents to penetrate into the paper structure. TvL and ABTS molecules are also trapped in the PVA polymer network due to swelling effect of water. Electrostatic attractions between the PVA and ABTS and TvL molecules do not contribute to the colour reaction.

This study is about the properties of the sets of objects associated in a structure resulting from multiple-processes involving chance as are materials whose texture is unordered and random. Being a paper scientist the author refers to the sheet of paper which is a stochastic fibrous set whose porous texture can be considered as an archetype for many natural or artificial human structures. The paper properties are correlated with its texture by taking account the effect of chance occurring during its manufacturing process. The theoretical developments, the formalism and the application methods presented in this study have a general significance beyond the only paper material.A specific property of sets of objects randomly unorderly distributed in space is their interfaces orientation distribution. This distribution is usually obtained by the analysis of images sampled in the object sets. The density of orientation probability of the fibers or of the texture interfaces, weighted by their length or by their area, can be interpreted as the radius of curvature of an outline or of a warped surface which characterizes, from a global and statistical point of view, the texture geometry in two or three dimensions. This figure named by the author the "equivalent pore", is with its elliptical shape similar to the one of the mean pore defined by the mean directional chord between the interfaces in the texture. Different methods of "equivalent pore" establishing are analyzed : by conformal map of the fiber network or of the texture interfaces, by images stereometric analysis of texture tomographical cuts, by scattering and diffraction of a laser light beam impacting the fibrous texture or the material surface replica, by hard X-ray absorption and phase contrast at the European Synchrotron Radiation Facilities(ESRF), in Grenoble. The "equivalent pore" concept allows us to study random unordered sets behavior in strength fields while simplifying this analysis. Thus a phenomenon occurring in a plane set, in two dimensions, can be analyzed on its "equivalent pore" linear outline, and a phenomenon which occurs in volume in a three dimensional set can be analyzed on its "equivalent pore" warped surface. This concept has been applied for physical, mechanical, optical and ionic conduction properties of materials like papers, boards, felts, nonwoven textiles, polymer foams, metallic alloys with grain joints, geological grounds, and for the surface mapping of natural relief and of materials with different gloss, worn or roughness levels.The ellipse and the ellipso\"id, as well as multi-modes compositions of it, are the most appropriate figures to represent the "equivalent pore" of materials with a random unordered texture. The fact that a law, which defines the curvature of an elliptic deterministic geometrical configuration, is essential to represent interface orientation allocation of elements whose spatial distribution is probabilistic is a noteworthy fact that makes us wonder. This assertion is corroborated by fluid flow analysis through porous media. The global dissipated energy for fluid flow is distributed along the motion (translation and rotation) and fluid deformation components on the "equivalent pore" whose surface is conformal to the texture interfaces tangential space. The porous media being homogenous and the fluid particles indistinguishable each ones from the others, due to permanent stochastic exchanges from one fluid volume element into another, we conclude that their motion quantification is invariant on each point of the "equivalent pore" surface. This quantification can be represented by a group of elliptical cylinders.The "equivalent pore" and cylinders group surface intersections define the fluid particle probabilistic paths in the porous media. One singular geometrical configuration of the elliptic cylinders group union with the ellipsoidal "equivalent pore" fulfills the minimal energy dissipation requirements in the stress field applied to the fluid. The resulting paths are ellipso\"ido-cylindrical curves carpeting the ellipso\"id by a beam of isoperim\'etric lacets, in close or open loops depending on the possible pairing off the curves in their nodals and isoclinal tangency points. The flow laminarity and unrotationality are globally established in the porous media at the macroscopic scale, for Reynold's number small values, in agreement with the results found moreover. The so defined ellipso\"ido-cylindrical curve is a stationary curve at the average least action meaning, for a punctual mobile or a deformable volume element moving on the surface of the ellipsoid from a nodal spot to the other in an antipodal position. This curve establishes a gauge which characterizes, from a global point of view, the physical space embraced by the fluid during its flow, in dynamical balance conditions compatible with the stress field. The ellipso\"ido-cylindrical curve allows to carpet the ellipso\"id as a function of one cyclic angular variable, which is a new construction for the ellipso\"id. When the set of the objects is isotropic the curve is sphero-cylindrical whose plan mapping permit to decipher the tai-chi figure of the Tao\"ist Buddhism philosophy.This study of random unordered object sets, and more specially of fibrous porous media, allows to establish a structural link between their small scale texture stochastic disorder and the harmonious order that emerges from these sets at a larger scale. The largest chance possible, compatible with the stress field which put a strain on these sets, is the necessary and sufficient variable which allows to best globally adjust their behaviors according to the probabilistic and deterministic laws governing their evolution.The vocabulary used in this study is issued from the common language, most of the time adapted to the material class, it is transposable in other fields of interest. The text is completed by notes and a bibliography which refer to the works done following the presented concepts or in relation to this field of studies., Comment: Derni\`ere version, in French

E-mail address: c-guillaume@univ-montp2.fr; International audience; The objective of the present work was to understand how the structural, surface, water vapour and gas barrier properties of wheat gluten (WG) coated paper could be influenced by the features of paper. For this purpose, a surface treated paper (TP) and an untreated paper (UTP) were compared. Penetration of WG-coating into the bulk of paper was more pronounced in UTP than TP. This led to the formation of a significant junction zone resulting in an interpenetrated structure for WG–UTP, suggesting a composite- like structure, while a bi-layer one was obtained for WG–TP. Differences in WG penetration were related to the hydrophilicity, roughness and porosity of the paper used. Even though the extent of penetration did not greatly affect the surface properties (water and oil resistance), the transfer properties (water vapour, O2 and CO2) of WG-coated papers were significantly improved when WG-coating highly penetrated: while the WG–TP behaved as a micro-perforated material, the WG–UTP behaved as WG-film

Adsorption isotherms of 3 selected paper-based packaging materials, that is, vegetable parchment (VP) paper, Kraft paper, and solid-bleached-sulfate (SBS) paperboard, were determined at 3 different temperatures (25, 40, and 50 degrees C). The GAB isotherm model was found to fit adequately for describing experimental adsorption isotherm data for the paper samples. The monolayer moisture content of the paper samples decreased with increase in temperature, which is in the range of 0.0345 to 0.0246, 0.0301 to 0.0238, and 0.0318 to 0.0243 g water/g solid for the MG paper, the Kraft paper, and the SBS paperboard, respectively. The net isosteric heats of sorption (q(st)) for the paper samples decreased exponentially with increase in moisture content after reaching the maximum values of 18.51, 27.39, and 26.80 kJ/mol for the VP paper, the Kraft paper, and the SBS paperboard, respectively, at low-moisture content. The differential enthalpy and entropy of 3 paper samples showed compensation phenomenon with the isokinetic temperature of 399.7 K indicating that water vapor had been adsorbed onto the paper samples with the same mechanism. Depending on the paper material, tensile strength of paper samples was affected by moisture content.

This study is about the properties of the sets of objects associated in a structure resulting from multiple-processes involving chance as are materials whose texture is unordered and random. Being a paper scientist the author refers to the sheet of paper which is a stochastic fibrous set whose porous texture can be considered as an archetype for many natural or artificial human structures. The paper properties are correlated with its texture by taking account the effect of chance occurring during its manufacturing process. The theoretical developments, the formalism and the application methods presented in this study have a general significance beyond the only paper material.A specific property of sets of objects randomly unorderly distributed in space is their interfaces orientation distribution. This distribution is usually obtained by the analysis of images sampled in the object sets. The density of orientation probability of the fibers or of the texture interfaces, weighted by their length or by their area, can be interpreted as the radius of curvature of an outline or of a warped surface which characterizes, from a global and statistical point of view, the texture geometry in two or three dimensions. This figure named by the author the “equivalent pore”, is with its elliptical shape similar to the one of the mean pore defined by the mean directional chord between the interfaces in the texture. Different methods of “equivalent pore” establishing are analyzed : by conformal map of the fiber network or of the texture interfaces , by images stereometric analysis of texture tomographical cuts, by scattering and diffraction of a laser light beam impacting the fibrous texture or the material surface replica, by hard X-ray absorption and phase contrast at the European Synchrotron Radiation Facilities( ESRF), in Grenoble. The “equivalent pore” concept allows us to study random unordered sets behavior in strength fields while simplifying this analysis. Thus a phenomenon occurring in a plane set, in two dimensions, can be analyzed on its “equivalent pore” linear outline, and a phenomenon which occurs in volume in a three dimensional set can be analyzed on its “equivalent pore” warped surface. This concept has been applied for physical, mechanical, optical and ionic conduction properties of materials like papers, boards, felts, nonwoven textiles, polymer foams, metallic alloys with grain joints, geological grounds, and for the surface mapping of natural relief and of materials with different gloss, worn or roughness levels.The ellipse and the ellipsoïd, as well as multi-modes compositions of it, are the most appropriate figures to represent the “equivalent pore” of materials with a random unordered texture. The fact that a law, which defines the curvature of an elliptic deterministic geometrical configuration, is essential to represent interface orientation allocation of elements whose spatial distribution is probabilistic is a noteworthy fact that makes us wonder. This assertion is corroborated by fluid flow analysis through porous media. The global dissipated energy for fluid flow is distributed along the motion (translation and rotation) and fluid deformation components on the “equivalent pore” whose surface is conformal to the texture interfaces tangential space. The porous media being homogenous and the fluid particles indistinguishable each ones from the others, due to permanent stochastic exchanges from one fluid volume element into another, we conclude that their motion quantification is invariant on each point of the “equivalent pore” surface. This quantification can be represented by a group of elliptical cylinders.The “equivalent pore” and cylinders group surface intersections define the fluid particle probabilistic paths in the porous media. One singular geometrical configuration of the elliptic cylinders group union with the ellipsoidal “equivalent pore” fulfills the minimal energy dissipation requirements in the stress field applied to the fluid. The resulting paths are ellipsoïdo-cylindrical curves carpeting the ellipsoïd by a beam of isoperimétric lacets, in close or open loops depending on the possible pairing off the curves in their nodals and isoclinal tangency points. The flow laminarity and unrotationality are globally established in the porous media at the macroscopic scale, for Reynold’s number small values, in agreement with the results found moreover. The so defined ellipsoïdo-cylindrical curve is a stationary curve at the average least action meaning, for a punctual mobile or a deformable volume element moving on the surface of the ellipsoid from a nodal spot to the other in an antipodal position. This curve establishes a gauge which characterizes, from a global point of view, the physical space embraced by the fluid during its flow, in dynamical balance conditions compatible with the stress field. The ellipsoïdo-cylindrical curve allows to carpet the ellipsoïd as a function of one cyclic angular variable, which is a new construction for the ellipsoïd. When the set of the objects is isotropic the curve is sphero-cylindrical whose plan mapping permit to decipher the tai-chi figure of the Taoïst Buddhism philosophy.This study of random unordered object sets, and more specially of fibrous porous media, allows to establish a structural link between their small scale texture stochastic disorder and the harmonious order that emerges from these sets at a larger scale. The largest chance possible, compatible with the stress field which put a strain on these sets, is the necessary and sufficient variable which allows to best globally adjust their behaviors according to the probabilistic and deterministic laws governing their evolution.The vocabulary used in this study is issued from the common language, most of the time adapted to the material class; it is transposable in other fields of interest. The text is completed by notes and a bibliography which refer to the works done following the presented concepts or in relation to this field of studies., Cette étude concerne les propriétés des ensembles d’objets associés dans une structure qui résulte de processus multiples où intervient le hasard, comme c’est le cas dans les matériaux dont la texture est non ordonnée, aléatoire. L’auteur fait référence à la feuille de papier, un ensemble fibreux qui peut être considérée comme un archétype pour de nombreuses structures existantes dans la nature ou élaborées par l’homme. Les propriétés d’usage du papier sont mises en corrélation d’avec sa texture en montrant l’incidence des effets du hasard qui intervient au cours de son procédé de fabrication. Les développements théoriques, le formalisme et les méthodes d’application présentés dans cette étude ont une portée générale au delà du seul domaine du matériau papier. Une propriété discriminante des ensembles d’objets distribués dans l’espace de manière désordonnée aléatoire est la répartition en orientation de leurs interfaces. Cette répartition s’obtient généralement par l’analyse d’images échantillonnées dans les ensembles. Dans une texture poreuse fibreuse la densité de la probabilité en orientation des fibres ou de l’orientation des interfaces de la texture, pondérée par leur longueur ou leur aire peut s’interpréter en tant que rayon de courbure d’un contour ou d’une surface qui caractérise, d’un point de vue statistique et global, la géométrie de la texture en deux ou en trois dimensions. Cette figure dénommée par l’auteur : le pore équivalent, a dans de nombreux cas une forme elliptique ou ellipsoïdale et est semblable au pore moyen défini par la corde moyenne évaluée dans les différentes directions entre les interfaces de la texture.Différentes méthodes de construction du pore équivalent sont analysées : par transformation conforme du réseau des fibres ou des interfaces de la texture, par l’analyse stéréométrique des images et de coupes tomographiques, par des micro tomographies avec des rayons X de haute énergie à l’E.S.R.F. de Grenoble, par diffraction et par diffusion de la lumière d’un faisceau laser impactant la texture fibreuse ou la réplique de ses surfaces. Le concept du pore équivalent permet d’étudier le comportement des ensembles désordonnés aléatoires dans des champs de forces, en simplifiant l’analyse. Ainsi un phénomène qui se produit dans un ensemble plan peut s’analyser sur le contour linéaire de son pore équivalent et un phénomène qui se produit en volume dans un ensemble en trois dimensions peut s’analyser sur la surface gauche bidimensionnelle de son pore équivalent. Ce concept a été appliqué pour l’étude des propriétés physiques, mécaniques, optiques et de conduction ionique de matériaux tels que les papiers et les cartons, les feutres, les voiles textiles non-tissés, les mousses de polymères, les alliages métalliques avec des joints de grains, les structures géologiques, la rugosité des matériaux, leur degré de brillant , leur abrasion et le relief des ensembles naturels.L’ellipse et l’ellipsoïde ainsi que leurs compositions multimodales sont les figures les mieux adaptées pour représenter le pore équivalent des matériaux à texture désordonnée aléatoire. Qu’une loi qui définit la courbure d’une configuration géométrique déterministe, elliptique, s’impose pour représenter la répartition en orientation des interfaces d’éléments dont la distribution dans l’espace est statistiquement probabiliste, est un fait remarquable qui nous interroge. Cette assertion est corroborée par l’analyse de l’écoulement des fluides dans un milieu poreux. L’énergie dissipée dans l’écoulement est répartie en fonction des composantes de déplacement, en translation et en rotation ainsi que de déformation du fluide, sur le pore équivalent dont la surface est conforme à celle de l’espace tangentielle des interfaces de la texture. Le milieu poreux étant homogène et les particules du fluide indiscernables les unes par rapport aux autres, compte tenu des échanges stochastiques continuels d’un élément de volume dans un autre, on conclut que la quantification de leurs mouvements est invariante d’un point de vue statistique en chaque point de la surface du pore équivalent. De manière générale un groupe de cylindres elliptiques permet de représenter cette quantification. Les intersections de la surface du groupe de cylindres d’avec la surface du pore équivalent définissent ainsi les trajectoires probabilistes des particules du fluide, de manière virtuelle et holiste dans le milieu poreux. Une configuration géométrique particulière du groupe de cylindres elliptiques et du pore équivalent ellipsoïdal, satisfait les conditions de dissipation d’énergie minimale pour l’écoulement du fluide et d’entropie maximale dans les conditions des sollicitations. Ces trajectoires tapissent l’ellipsoïde par un faisceau de lacets homotopes ellipsoïdo-cylindriques, en boucles ouvertes ou fermées, suivant les appariements possibles en leurs points nodaux de regroupement et/ou de tangence isocline. La laminarité et l’irrotationnalité de l’écoulement sont établies à l’échelle macroscopique de manière globale et aux faibles valeurs du nombre de Reynolds ce qui est en accord avec les résultats obtenus par d’autres méthodes d’analyse. La courbe ellipsoïdo-cylindrique ainsi définie est stationnaire quand à la moindre action dans le déplacement d’un élément de volume du fluide sur la surface de l’ellipsoïde pour aller d’un point ombilic à l’autre en position antipodale. Cette courbe permet de réaliser une tapisserie de l’ellipsoïde, de manière unicursale, en fonction d’une variable angulaire cyclique, ce qui permet de construire de manière générale un ellipsoïde tri axes. Tel un stick déformable la courbe ellipsoïdo- cylindrique caractérise dans sa globalité l’espace embrassé par le fluide en écoulement dans le milieu poreux, dans des conditions d’équilibre dynamique du fluide. Lorsque l’ensemble d’éléments désordonné aléatoire, est isotrope la courbe est une hippopède qui fait partie de la variété des courbes sphéro-cylindriques. Le développement dans l’espace de cette courbe, projeté dans un plan permet de décrypter le tai-chi, figure symbolique dans la philosophie bouddhique Taoïste de l’équipartition de l’énergie vitale suivant les principes du Yin et du Yang.Cette étude des ensembles désordonnés aléatoires et plus particulièrement des milieux poreux fibreux, établit un lien structurel entre le désordre stochastique de leurs éléments à petite échelle et l’ordre qui émerge de ces ensembles à une plus grande échelle dans les conditions d’équilibre dynamique vis-à-vis de leurs sollicitations. Le hasard le plus grand qui soit est la variable nécessaire et suffisante qui permet d’optimiser dans sa globalité leur comportement suivant les lois, déterministes et probabilistes, qui conditionnent leur évolution. Le vocabulaire de cette étude est celui du langage commun le plus souvent adapté à la classe des matériaux ; il est transposable dans d’autres domaines d’intérêt. Des notes annexes ainsi qu’une bibliographie sur des travaux effectués suivant les concepts présentés ou proches du domaine de l’étude complètent le texte.

The purpose of this study using a scanning electron microscope was to investigate the efficacy of four different irrigation techniques after canal preparation with Profile Ni-Ti rotary instruments. A modified technique for the use of Glyde File Prep is proposed. Forty anterior teeth were divided into four groups, instrumented, and irrigated as follows: physiological solution (group A), 2.5% sodium hypochlorite (group B), 2.5% sodium hypochlorite and Glyde File Prep (group C), and 2.5% sodium hypochlorite and Glyde File Prep applied at the end of the preparation with sterile paper points (group D). After scanning electron microscopic evaluation at three different levels, debris, smear layer, and dentinal tubules were scored. Groups A and B had significantly more smear layer and less open tubules on the canal walls compared with the group C and group D samples. Differences in the mean amount of debris between group A samples and other irrigation regimes were statistically significant.

In this paper, the preliminary study on the impact of filamentous particles (FP) in the septic tank effluent (STE) on filter cake (FC) development was presented. The number, length and diameter (30 p./cm3, 451 and 121 microm, respectively, on average) of FPs were measured using microscope image analysis of STE samples condensed using a vacuum evaporation set. Results of this study showed, that 0.73% of volatile suspended solids (VSSs) mass from the STE occurs in the form of FPs. No correlation between FP total mass and VSS was found. An experiment with a layer of FPs simulated by ground toilet paper was conducted and showed the impact of this layer (4.89 mg/cm2) on wastewater hydraulic conductivity--for an FC with FPs (FC-FP), hydraulic conductivity was seven times lower than for the FC without the FP layer, and on outflow quality (lower concentration of organic matter expressed as chemical oxygen demand (COD) in effluent from the FC-FP filter than in the effluent from the FC filter: 618 and 732 gO2/m3, respectively). Despite a relatively small amount of FPs in STE solids (as volume fraction), they play an important role in FC development due to their relatively high length and low degradability. Probably relatively small pores of the FC containing FPs (FC-FP) caused a small particle blocking and a decrease in permeability.

To comply with state requirements, cigarette manufacturers have added low-permeability bands to the cigarette paper. These bands can extinguish the cigarette when it is no longer being puffed by a smoker.This study was conducted to evaluate the toxicology resulting from the addition of different types of bands to experimental cigarettes.A battery of assays that are typically used in toxicology studies with cigarette smoke, namely smoke chemistry, in vitro mutagenicity and cytotoxicity, and inhalation studies with rats, were used to evaluate different band characteristics added to cigarette paper.Although differences in the amount of band material was associated with an increase in some metals measured in mainstream tobacco smoke, it was not dose responsive to any band design parameter (base paper permeability, band width, band spacing, band chalk amount, or citrate). Occasional, minor differences were produced by the different types of bands; overall, there was no increased toxicity.Although there were increases and decreases in some mainstream smoke constituents, the in vitro and in vivo testing performed demonstrated that low-permeability bands on cigarettes do not modify the toxicity of smoke inhaled by smokers.

Papers coated with caseinate and caseinate/chitosan bilayer films were developed. Caseinate, chitosan and caseinate/chitosan films were preliminary characterized by FTIR spectroscopy and thermal stability analyses. The effects of coating weight, caseinate concentration (7%, 10%, and 12%, w/w), and coating application methods (single layer and bilayer) on the physical and mechanical properties of coated papers were studied. Increasing the concentration of caseinate led to a decrease in water vapor permeability (WVP) of the resulting coated paper sheets. Chitosan significantly (p0.05) increased the elongation at break (%E) of coated paper. However, the application of chitosan as a second layer on wet or dry caseinate films did not significantly affect (p0.05) the tensile strength (TS) of coated paper. The greatest reduction in paper WVP is achieved by addition of a chitosan layer to the dried preformed caseinate-coated paper.

This paper describes the fabrication of pressure-driven, open-channel microfluidic systems with lateral dimensions of 45-300 microns carved in omniphobic paper using a craft-cutting tool. Vapor phase silanization with a fluorinated alkyltrichlorosilane renders paper omniphobic, but preserves its high gas permeability and mechanical properties. When sealed with tape, the carved channels form conduits capable of guiding liquid transport in the low-Reynolds number regime (i.e. laminar flow). These devices are compatible with complex fluids such as droplets of water in oil. The combination of omniphobic paper and a craft cutter enables the development of new types of valves and switches, such as "fold valves" and "porous switches," which provide new methods to control fluid flow.

This paper describes the results of laboratory experiments using a thermophilic aerobic MBR (TMBR) at 50 °C. An innovative use of submerged flat-sheet MBR modules to treat circuit wastewater from the paper industry was studied. Two experiments were conducted with a flux of 8–13 L/m 2 /h without chemical membrane cleaning. COD and BOD 5 elimination rates were 83% and 99%, respectively. Calcium was reduced from 110 to 180 mg/L in the inflow to 35–60 mg/L in the permeate. However, only negligible membrane scaling occurred. The observed sludge yield was very low and amounted to 0.07–0.29 g MLSS/g COD eliminated . Consequently, the nutrient supply of ammonia and phosphate can be lower compared to a mesophilic process. Molecular-biological FISH analysis revealed a likewise high diversity of microorganisms in the TMBR compared to the mesophilic sludge used for start-up. Furthermore, ammonia-oxidising bacteria were detected at thermophilic operation.

Fundamental investigations of human biology, and the development of therapeutics, commonly rely on 2D cell-culture systems that do not accurately recapitulate the structure, function, or physiology of living tissues. Systems for 3D cultures exist but do not replicate the spatial distributions of oxygen, metabolites, and signaling molecules found in tissues. Microfabrication can create architecturally complex scaffolds for 3D cell cultures that circumvent some of these limitations; unfortunately, these approaches require instrumentation not commonly available in biology laboratories. Here we report that stacking and destacking layers of paper impregnated with suspensions of cells in extracellular matrix hydrogel makes it possible to control oxygen and nutrient gradients in 3D and to analyze molecular and genetic responses. Stacking assembles the “tissue”, whereas destacking disassembles it, and allows its analysis. Breast cancer cells cultured within stacks of layered paper recapitulate behaviors observed both in 3D tumor spheroids in vitro and in tumors in vivo: Proliferating cells in the stacks localize in an outer layer a few hundreds of microns thick, and growth-arrested, apoptotic, and necrotic cells concentrate in the hypoxic core where hypoxia-sensitive genes are overexpressed. Altering gas permeability at the ends of stacks controlled the gradient in the concentration of the O 2 and was sufficient by itself to determine the distribution of viable cells in 3D. Cell cultures in stacked, paper-supported gels offer a uniquely flexible approach to study cell responses to 3D molecular gradients and to mimic tissue- and organ-level functions.

Poly(lactide)-coated paperboards were prepared by a solution coating method, and the effect of coating to improve properties of paperboard used for the manufacturing of 1-way paper cups was tested. Surface of PLA-coated paperboards was smooth and shiny like PE-coated paperboard, and the coating weight and thickness increased linearly with increasing PLA concentration of coating solution. Tensile strength (TS) and elongation at break (E) of the paperboard also increased after PLA coating. Water vapor barrier or water-resistant properties tested, such as water vapor permeability (WVP), water absorptiveness (WA), and contact angle (CA) of water drop, indicated that water resistance of the paperboard was improved through surface coating with PLA. The increase in water resistance of PLA-coated paperboards was mainly due to the hydrophobicity of PLA and the improvement of water barrier properties increased depending on the PLA concentration. In addition, PLA-coated paperboard showed strong heat sealing property when coated with more than 1 w/v% of PLA. Wet strength of PLA-coated (3, w/v%) paperboard was comparable to or greater than that of PE-coated paperboard. All the test results indicated that the PLA-coated paperboard can be exploited for the manufacturing of 1-way paper cups as an alternative to the PE-coated paperboard.

This study was conducted to evaluate the pretreatment effects of different in vivo moxibustion on the permeation of a model high molecular compound, FITC-dextran, with a mean molecular weight of 4 kDa (FD-4), through excised hairless rat skin. Direct or indirect moxibustion (0.10 g moxa) was pretreated consecutively 4 times every 5 min on the abdomen of hairless rats, and the permeation of FD-4 was determined through the excised skin over 8h from 30 min after starting the first moxibustion. This consecutive moxibustion pretreatment showed a significant increase in the skin temperature as well as skin permeation of FD-4 compared with the control group (no moxibustion pretreatment). Quantitative parameters showed an increase in skin temperature and skin permeation: the area under the skin temperature over control temperature-time curve during one burning cycle (5.0 min) (AUCtemp) or the maximum skin temperature during moxibustion (Tmax) and the cumulative amount of FD-4 permeated through skin over 8h (Q8) or steady-state flux were increased by moxibustion pretreatment. Then, the effect of pedestal thickness (distance from the moxa cylinder and skin surface), shape of the moxa cylinder (5mm diameter, 13 mm height or 9 mm diameter, 7 mm height), burning materials (moxa or aromatic incense), pedestal component (paper, potato or ginger) and moxibustion pretreatment method (direct or indirect moxibustion) was evaluated on the AUCtemp or Tmax and Q8 or flux. The amount of protein leached from the skin surface was also determined as an inflammatory index by this moxibustion pretreatment. When the skin temperature was increased to 60 degrees C, the Q8 or flux as well as the amount of protein leached were markedly increased. When the skin temperature was controlled to 42 to 45 degrees C by an adequate selection of pedestal thickness, shape of the moxa cylinder, burning materials, pedestal component and moxibustion pretreatment method, on the other hand, protein leaching remained unaltered, but the Q8 or flux significantly increased with the Tmax. This study thus provides credible evidence that moxibustion pretreatment increases the skin permeation of high molecular compounds.

The objective of this work was to study the transfer of four aroma compounds (ethyl butyrate, ethyl hexanoate, cis-3-hexenol, and benzaldehyde) from a solid and complex-flavored food matrix (sponge cake) toward and through packaging films placed in indirect contact during storage in accelerated aging conditions (38 °C and 86% relative humidity gradient). The efficiency of treated papers relative to that of standard paper and plastic as barrier was tested. Before storage, aroma compound volatility in the sponge cake was measured, and similar values were found between aroma compounds, due to the fat content of the sponge cake. Whatever the aroma compound, permeability values during storage were similar for the same packaging film. The plastic film was the highest barrier, whereas calendering and coating treatments applied to treated papers decreased effectively their permeability. An opposite trend was observed for aroma compound sorption into packaging films during storage. Keywords: Aroma compound; sponge...