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Euler deconvolution technique is one of the methods that predicts the subsurface features and structures with help of gravity modelling. The present study was performed to identify the earth’s geothermal potentials in Dholera, Unai, and Gandhar regions of Gujarat, India using gravity technique. The structures and layers of the subsurface were determined by performing the gravity survey and the interpretation of data was carried out using Euler Deconvolution. The survey was conducted along six profile lines: five horizontal and one perpendicular to others in the study areas. After acquiring gravity data, various corrections were applied to convert raw gravity data to corrected Bouguer gravity data. In this paper density of the subsurface formation has been determined using Nettleton and Parasnis methods, which suggests that the subsurface of Dholera, Unai, and Gandhar have densities close to sedimentary rocks. After density determination, regional and residual separation was performed on the Bouguer gravity data to get information on geothermal causative bodies. In this paper, the Euler Deconvolution method was applied to interoperate the spatial position and depth of the subtle geothermal bodies. The Euler solutions for depth in Dholera, Unai, and Gandhar range between 1324–4300 m, 1877–4813 m, and 2345–5536 m. The results of gravity Euler Deconvolution suggests the presence of geothermal potential in these regions.

Korean hand papermaking is a renowned cultural tradition in the Korean peninsula. It is still practiced while scientific analysis of paper itself from a large data set is rare. In this study, a set of more than three hundred Korean handmade papers, collected in a reference collection book Hanji: Korean handmade paper, were chemically investigated, and their property data such as colour, pH, grammage, thickness, tensile strength, folding endurance were statistically analysed in order to determine general features for Korean papers. The influence of different paper sheet formation methods (Heullimtteugi vs Gadumtteugi) were revealed by multivariate data analysis and the chemical profiles of raw materials were studied by pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). The Korean handmade paper samples display colour gamut in the colour space L* (69.9–95.9), a* [(−3)-3], b* (0–20), most have neutral/alkaline pH values. Paper density, fiber orientation and physical properties are influenced by the sheet formation techniques. For instance, Gadumtteugi tends to produce papers with strong fiber orientation while Heullimtteugi produces papers with more evenly distribution of fibers. In addition, Py-GC/MS analysis results show that paper mulberry fibers contain less intensity lignin monomers and more terpenic compounds in comparison with gampi and mitsumata fibers. This study provides paper analysis from large sample set, statistics reveal that the material preparing and making craft determined the paper structure which reflected in their physical properties. These properties influenced paper performance and applications in art creations as well as relics conservation and restoration. The characterized paper sample database could be used for handmade paper studies in East Asian region. Consequently, this study contributes to a better understanding of contemporary Hanji properties as well as improves knowledge on handmade papers from the Korean peninsula.

Relevance of the research topic. Many factors affect the properties of paper, in particular the composition of fibrous semi-finished products, the nature of the grinding of fibrous materials, the introduction of fillers and modifying additives into the pulp, the regime of ebb and drying and many others. Among the technological factors that have the greatest influence on paper properties, calendaring and finishing operations have a special place, in which the density of the paper web can be changed at significant intervals.Formulation of the problem. To obtain paper with desired properties, it is sealed on a supercalender. At the same time, additional compaction of the paper composition enhances impermeability by changing the nature of the distribution and compaction of cellulose fibers and the total number of pores in its structure.Analysis of recent research and publications. Recent publications on the possibility of obtaining paper with desired properties by controlled changes in the microstructure of the paper web during the calendaring process were considered.Isolation of previously unexplored parts of a common problem. The study of the properties of paper subjected to compaction to varying degrees during the manufacturing process, ceteris paribus, is of urgent scientific and practical interest, in particular, for the manufacture of materials with a given set of consumer properties.Formulation of the problem. The purpose of the study is to identify the features of the microstructure of paper of different densities, manufactured ceteris paribus, and to establish the effect of the degree of compaction of paper in the manufacturing process on its properties.The presentation of the main material. Comparative studies of the structural characteristics of paper for water-resistant water and grease-proof packaging material made of sulphate pulp, milled to a degree of 75 ° SR with varying degrees of compaction were carried out. Four paper samples of different mass per square meter of area and density were studied. Their microstructure and a number of consumer properties characterizing absorption, barrier and strength properties are characterized.Conclusions according to the article. Experimentally established the optimal level of density - 0.75-0.85 g/cm3 . Softwood sulphate pulp is defined as the most suitable for base paper, can be used for the production of paper packaging materials with desired properties for moisture and fat-containing products., Актуальність теми дослідження. Властивості паперу обумовлені багатьма чинниками, зокрема композицією волокнистих напівфабрикатів, характером помелу волокнистих матеріалів, введенням в паперову масу наповнювачів та модифікуючих добавок, режимом відливу та сушіння тощо. Серед технологічних факторів, що мають найбільший вплив на властивості паперу, чільне місце посідають операції каландрування та остаточної обробки, під час яких у значних інтервалах можна змінювати щільність паперового полотна.Постановка проблеми. Для отримання паперу із заданими властивостями проводять його ущільнення на суперкаландрі. При цьому додаткове ущільнення композиції паперу також сприяє підвищенню непроникності за рахунок зміни характеру розподілу й ущільнення целюлозних волокон та загальної кількості пор у його структурі.Аналіз останніх досліджень і публікацій. Були розглянуті останні публікації щодо можливості отримання паперу із заданими властивостями шляхом керованої зміни мікроструктури паперового полотна у процесі каландрування.Виділення недосліджених частин загальної проблеми. Дослідження властивостей паперу, що піддається ущільненню до різного ступеня у процесі виготовлення, за інших рівних умов, має актуальний науковий та практичний інтерес, зокрема, для виготовлення матеріалів із заданим комплексом споживних властивостей.Постановка завдання. Мета дослідження полягає у виявленні особливостей мікроструктури паперу різної щільності, виготовленого за інших рівних умов, та встановленні впливу ступеня ущільнення паперу в процесі виготовлення на його властивості.Виклад основного матеріалу. Проведено порівняльні дослідження структурних характеристик паперу для вологоміцного водо- та жиронепроникного пакувального матеріалу, виготовленого із сульфатної целюлози розмеленої до ступеня 75 °ШР із різним ступенем ущільнення. Досліджено чотири зразки паперу різної маси квадратного метра площі та щільності. Охарактеризовано їхню мікроструктуру та абсорбційні, бар’єрні та міцнісні властивості.Висновки відповідно до статті. Експериментальним шляхом встановлено оптимальний рівень щільності – 0,75-0,85 г/см3. Білена та небілена сульфатна целюлоза із хвойних порід деревини визначена як найбільш придатна для отримання паперу-основи, що може використовуватись для виробництва паперових пакувальних матеріалів із заданими властивостями для волого- і жировмісної продукції.

Roll-paper storage is one of the most challenging hazards for fire protection. This work studies the fire behavior of hard surface roll paper with different paper basis weights (i.e., area density) and inert content. Intermediate-scale tests were conducted including both free-burn tests and water suppression tests using the water application apparatus (WAA). The measured heat release rates (HRRs) and applied water fluxes were analyzed to calculate the critical delivered flux (CDF) for the selected papers. The test results showed that roll paper with a larger area density or a higher inert content generally has a lower fire growth rate and a lower CDF. A roll paper density parameter is proposed to reflect the impact of both the paper basis weight and inert content. This parameter shows consistent correlations with fire growth and suppression and thus can be recommended as a means of roll paper classification for fire protection.

Стаття присвячена розробленню та реалізації концепції формування якості паперу-основи для виготовлення вологоміцних водожиронепроникних паперових пакувальних матеріалів різного цільового призначення із заданим рівнем бар’єрних та захисних властивостей, яка полягає у створенні високощільної і зімкнутої структури пакувального паперу із заданим опором проникненню жиру та води. Проведено комплексні дослідження впливу виду целюлози, ступеня помелу целюлозного волокна, складу і структури паперу-основи на вологоміцність, водонепроникність та жиронепроникність паперових пакувальних матеріалів. Встановлено, що найбільш ефективною волокнистою сировиною для виробництва паперу-основи для вологоміцних водожиронепроникних пакувальних матеріалів є сульфатна білена і небілена целюлоза із хвойних порід деревини за ступеня помелу 65-75 °ШР., Introduction. The article is devoted to the development and implementation of the concept of paper base quality formation for the manufacture of moistureproof grease- and waterproof paper packaging materials for various purposes with a controlled level of barrier and protective properties, which consists in the creation of high-density and closed structure of packaging paper with the given grease and water resistance. Comprehensive studies of the influence of cellulose type, the degree of grinding of cellulose fiber, the composition and structure of the base paper on the moisture, water and grease resistance of paper packaging materials. It is established that sulfate bleached and unbleached pulp from coniferous wood at a grinding rate of 65-75°SR is the most effective fibrous raw material for the production of base paper for moisture-proof water-proof packaging materials. The aim of the work. The purpose of the study is to identify patterns and establish optimal parameters for the manufacture of base paper for waterproof and greaseproof paper packaging materials. Research methods. In the study sulfate unbleached cellulose of coniferous wood of the NS-2 brand of production of JSC Baltic Cellulose (Russia) and hardwood of the brand of NS-3 production of JSC Svetlogorsk Pulp and Cardboard Mill (Belarus) were used. Fibrous semi-finished products were subjected to dissolution and milling to the required degree of grinding (25-85 °C) in the presence of water in the laboratory role of VALLEY at a drum speed of 500 rpm. The degree of grinding was monitored on a Shopper-Riegler apparatus according to the standard method [30]. The paper samples were prepared using a sheet-fed laboratory instrument with a Rapid Kothen Combined Dryer. Problem formulation. To pack fatty products, paper packaging materials are used that have high barrier properties and protect it from contact with oxygen. It is proposed to achieve a high level of barrier properties and mechanical strength due to controlled regulation of base paper structure and treatment of its surface with substances that provide grease and water resistance.Description of the main material of the article. Paper samples were examined for basic char-acteristics that meet the requirements for packaging products with high water and grease content. The increased air resistance is ensured due to high closure of the paper surface obtained by using for its manufacture of highly fibrillated and hydrated in the process of grinding fibrous mass with a degree of grinding 65-75°SR.High quality pulp, the degree of development and homogeneity of fibrillated cellulose fibers in-crease the density of produced paper. Higher degree of fiber milling given more good value of the density of paper from bleached and unbleached sulfate cellulose of coniferous wood is more intense and reaches a greater absolute value – 0.45 and 0.48 g/cm3, respectively. With the increase of paper density, there is an increase in the main indicators of its mechanical strength: destructive force and resistance to stranding. Paper samples obtained from sulfur bleached and unbleached pulp at a grinding rate of 75°SR after pouring have a density of 0.45 and 0.48 g/cm3 and are characterized by the lowest grease per-meability among the tested samples – 453 and 311 holes/m2, respectively. Conclusions and recommendations. It is established that sulfate bleached and unbleached pulp from coniferous wood at a grinding rate of 65-75°SR is the most effective fibrous raw material for the production of base paper for moistureproof grease and waterproof packaging materials.

The Electrostatic Detection Apparatus® (ESDA) is an instrument employing techniques used by Questioned Document Examiners (QDE) for the development of indented impressions. It has been reported that impressions can be recovered from between three and five sheets beneath the original writing; however, there have been limited studies on the impact of paper type in this process. In this experiment, paper densities ranging from 54–170 g/m2 were examined and evaluated using a standard ESDA® protocol. Paper density affects both the quality and the depth at which an underlying impression can be visualized by electrostatic methods (between one and five sheets). Knowing the paper density could aid QDE in the effective examination of documents for impressions.

The manufacturing process of paper machines consists of several steps to produce high quality papers. This is done by sequentially lined-up machines including the head box, the drying sections, the finishing part and the wrapping systems. In the finishing part, the rollers of the paper calender compress the fibrous material involving viscoelastic and plastic deformations. Modern calenders are composed of several roller pairs, each consisting of a soft and a hard roller. The homogenization of the paper density and the refinement of the paper surface is achieved by the compression in the roller pairs. While very high values for the plastic strain occur in the first roller pair, the plastification decreases for the subsequent pairs. Therefore, the force distribution and the occurring vibrations can deviate significantly between the roller pairs. Two main vibration problems are observed in paper calenders caused by the contact and the orthotropic behavior of the paper: wear-induced corrugation on the surface of the soft rollers and sudden instabilities going along with high vibration amplitudes. In this paper the main focus is placed on a simplified modeling of the paper plastification during the calendering process. The restoring forces are non-smooth due to the plasticity and additional considerations have to be included for the derivation of the stability problem.

In this paper density, sound velocity, and refractive index for the binary system (butyric acid + hexanoic acid) were measured over the entire composition range and at 5 K intervals in the temperature range 293.15–313.15 K. The excess molar volumes, isentropic compressibilities, excess isentropic compressibilities, deviation in refractive indices, molar refractions, and deviation in molar refractions were calculated by using the experimental densities, sound velocities, and refractive indices, respectively. The Redlich–Kister equation was used to fit the excess molar volume, excess isentropic compressibility, deviation in refractive index and deviation in molar refraction data. The Lorentz–Lorenz approximation was used to correlate the excess molar volume from the deviation in refractive index and also to predict the density from refractive index or the refractive index from density of the binary mixtures. Four sound velocity mixing rules were tested and the best model for the systems studied in this work was the Berryman mixing rule. The thermodynamic properties are discussed in terms of intermolecular interactions between the components of the mixtures.

The effect of paper structure on blood typing visualization was quantified and analyzed to engineer low-cost diagnostics. Commercial and experimental papers varying in fibre composition, basis weight, density and porosity were investigated for their ability to separate agglutinated (blood interacted with specific antibodies) from non-agglutinated (blood interacted with non-specific antibodies) red blood cells (RBCs). Antibodies solutions and blood samples were sequentially absorbed on paper, allowed to interact, eluded with a saline solution, and the intensity of the remaining blood spot was quantified by image analysis. The efficiency and clarity of RBC separation was quantified with the relative intensity (R.I.) index defined as the intensity ratio of the non-specific test over the specific system; the lower the R.I., the better is the separation between a positive from a negative test. Thick and dense papers are improper for blood typing as they retain indiscriminately both agglutinated and non-agglutinated RBCs. Thin and porous papers provided the best performance. The R.I. index (the lower the better) increased fairly linearly with paper density and thickness but inversely proportionally with paper pore size. The type of fibres played a minor role. The paper structure is critical in the design of blood typing assay. However, it is only one element of the diagnostic system to engineer with the interactions RBC-antibody-paper.

In view of the fact that in some spectrochemical laboratories all kinds of materials have to be analysed, a general method of complete evaporation by means of the direct current carbon arc has been worked out. This method has been successfully applied for over two years, during which time 2500 analyses have been carried out, 30% of which have yielded quantitative results. Difficulties encountered in putting the method to the test (spluttering, decreasing or increasing the speed of vaporization of materials to be analysed) are described in this paper. The method of successive addition has proved to be of importance for the determination of the exponent n in the equation: (i = intensity of a spectrum line; k and n are constants and c the concentration of the element to be analysed): Some values of n are listed at the end of the paper. (The method of successive addition enables one to determine element concentrations independently of the chemical analysis, by adding successive amounts of that, element to the material under consideration and by measuring line intensities of mixtures prepared in this manner.) The method of measuring line intensities by means of s.p.d. scales, which gives rise to the choice of lines corresponding to electron transitions in the higher parts of the electron level diagram of an atom, has proved that the intensities of these lines show an n-value of about 1. The accuracy of the results obtained is discussed (S.p.d. scales (standard paper density scales) contain a set of lines of well-known increasing density (and corresponding relative intensity); the image of a spectrum line is compared with them on the screen of a spectrum projector. By this method the influence of background on line-intensities is eliminated).

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In the paper density functional theory method was applied to explore the electronic and magnetic properties of the GdNiSb in low-temperature phase with cubic MgAsAg-type structure and in the high-temperature phase. The calculations were performed by first principles full-relativistic full potential local orbital method within the local spin density approximation. The calculations results show the metallic character of GdNiSb compound in the high-temperature phase with hexagonal AlB2-type structure. For the low-temperature phase of the cubic GdNiSb system, they indicate a semiconducting behavior. The density of states below the Fermi level is greater in high-temperature phase than in low-temperature one, the calculated magnetic moment is in good agreement with an available experimental value.

In this paper density functionals for Coulomb systems subjected to electric and magnetic fields are developed. The density functionals depend on the particle density, $\rho$, and paramagnetic current density, $j^p$. This approach is motivated by an adapted version of the Vignale and Rasolt formulation of Current Density Functional Theory (CDFT), which establishes a one-to-one correspondence between the non-degenerate ground-state and the particle and paramagnetic current density. Definition of $N$-representable density pairs $(\rho,j^p)$ is given and it is proven that the set of $v$-representable densities constitutes a proper subset of the set of $N$-representable densities. For a Levy-Lieb type functional $Q(\rho,j^p)$, it is demonstrated that (i) it is a proper extension of the universal Hohenberg-Kohn functional, $F_{HK}(\rho,j^p)$, to $N$-representable densities, (ii) there exists a wavefunction $\psi_0$ such that $Q(\rho,j^p)=(\psi_0,H_0\psi_0)_{L^2}$, where $H_0$ is the Hamiltonian without external potential terms, and (iii) it is not convex. Furthermore, a convex and universal functional $F(\rho,j^p)$ is studied and proven to be equal the convex envelope of $Q(\rho,j^p)$. For both $Q$ and $F$, we give upper and lower bounds., Comment: 26 pages

A test for isotropy of images modeled as stationary or intrinsically stationary random fields on a lattice is developed. The test is based on wavelet theory, and can operate on the horizontal and vertical scale of choice, or on any combination of scales. Scale is introduced through the wavelet variances (sometimes referred to as the wavelet power spectrum), which decompose the variance over different horizontal and vertical spatial scales. The method is more general than existing tests for isotropy, since it handles intrinsically stationary random fields as well as second-order stationary fields. The performance of the method is demonstrated on samples from different (an)isotropic random fields, and compared to three existing methods. It is competitive with or outperforms existing methods since it consistently rejects close to the nominal level for isotropic fields while having a rejection rate for anisotropic fields comparable to the existing methods in the stationary case, and superior in the intrinsic case. As practical examples, paper density images of handsheets and mammogram images are analyzed.

The effects of paper properties such as density, air permeability, moisture transmission rate on the thermal performance of plate-type enthalpy exchanger were experimentally investigated. Three enthalpy exchanger samples having different properties were made, and were tested according to the standard test procedure (KS B 6879). Effective efficiencies were defined, which accounted for the air leakage between supply and exhaust streams. Results showed that paper density affected the sensible heat transfer of the samples. Sensible heat transfer increased with density of the paper. It was also shown that moisture transmission rate alone was not a proper indicator for the efficiency of latent heat transfer. Air permeability should also be considered for adequate evaluation of the latent heat transfer. Best performance was obtained for the sample having highest paper density and moderate moisture transmission ratio.Copyright © 2010 by ASME

Paper drying models are based on the assumption of a rigid solid matrix. Because of the interaction of water molecules and paper fibre the dimensions of the sheet are changing, especially the thickness. These changes influence the moisture transport within the material. A model of the paper structure has been developed taking into account different kinds of pores in the paper. By the assistance of this model the dependence between water content and thickness or transport parameters as permeability and thermal conductivity can be predicted. The only informations which are needed are sorption isotherms, apparent paper density and permeability of the single phase flow. Further informations as the pore size distribution are useful but not necessary. The transport parameters are generated in the suggested way for wood pulp. It is shown that in the case of convective drying, the agreement between experimental results and model simulations is good.

The development of a suitable conservation treatment for ink corrosion requires a thorough evaluation of a large number of model papers and inks as well as originals. While the currently used bursting strength evaluation gives an estimate of failure of documents along the corroded ink lines, in real-life situations, its repeatability is low and numerous measurements need to be performed to obtain a reasonably reliable value.It is suggested that model iron gall ink corroded papers may also be studied using viscometry, which is a simple, reliable method requiring only a small amount of sample. For original documents, where sampling for accelerated ageing is very restricted, scanning device assisted brightness determination of the verso of the writing is proposed for the evaluation of the effects of conservation treatment on paper during accelerated ageing. However, several parameters influencing colour formation and evaluation on the verso, including the rate of migration, paper density, surface furnish etc., prevent the method from being used to compare different papers before these effects are fully assessed.

This paper studies the correlation between the time-of-flight (TOF) of laser pulses and paper density, basis weight, thickness and the beating of pulp. Paper samples made from unbeaten and beaten pulp were compressed from 500kg/m3 to 1100kg/m3 and laser pulses were shot through them during pressing. Changes were observed in the thickness of the samples and in the TOF of the laser pulses. The results show that TOF decreases during comrpession. This indicates that distances between the various scattering surfaces decrease. This phenomenon becomes more pronounced as the basis weight increases. The beating of the pulp before papermaking increases the number of scattering surfaces, thus broadening the laser pulse and causing delay. These two effects cannot be separated with the equipment used. Papers made from different pulp types each have unique delay constants.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

1,1,1,3,3-pentafluorobutane (HFC-365mfc) is currently proposed as a substitute for CFCs in several applications. Experimental data on this fluid are still not sufficient to describe accurately its thermodynamic behaviour. Liquid density is one of the most important properties required to develop precise equations of state. At the state of the art, data of compressed and saturated liquid density are lacking. In this paper density in liquid phase was measured along eight isotherms ranging from 283.15 to 343.06 K at pressures up to 25 MPa. The paper presents also correlations for the compressed liquid by means of a Tait equation and the saturated liquid density.

Current demands in manufacturing of consumer electronics for smaller size, lighter weight and lower cost with high performance are most important. In order to meet these demands, high-density printed circuit boards (PCBs) are strongly required. Under this background, we have developed a new organic PCB called "ALIVH/sup (R)/" (any layer interstitial via hole). It realizes electric interconnections by interstitial via holes (IVHs) with cured conductive paste. Due to the ability to form the IVH in any layer and any position, the ALIVH substrate has an ideal IVH structure and is therefore excellent for high-density wiring. In the electric interconnections of ALIVH substrates, we found that it was the most important for the conductive paste to be compressed strongly in the laminating process. We examined one of the compression techniques, using nonwoven aramid paper as a reinforcing material. We studied the properties of nonwoven aramid-epoxy prepreg. As a result of our study, we found that the compression of the prepreg depended on the paper density and the resin content. Moreover, other PCB properties were also influenced by the paper density and the resin content. Therefore, the balance between the interconnection and the other properties is important to ALIVH substrates.

There is a need for accurate surface area measurement of internal irregular anatomical structures in order to define light dosimetry in adjunctive intraoperative photodynamic therapy (AIOPDT). No satisfactory pre- operative method exists of measuring this parameter. We have investigated whether computer-assisted triangulation of serial sections generated by computed tomography (CT) scanning can give an accurate assessment of the surface area of the walls of the true pelvis after anterior resection and before colorectal anastomosis. We have shown that the technique of paper density tessellation is an acceptable method of measuring the surface areas of phantom objects, with a maximum error of 0.5%, and is used as the gold standard. Computer-assisted triangulation of CT images of standard geometric objects and accurately- constructed pelvic phantoms gives a surface area assessment with a maximum error of 2.5% compared with the gold standard. The CT images of 20 patients' pelves have been analysed by computer-assisted triangula- tion and this shows that the surface area of the walls varies from 143 cm 2 to 392 cm 2 . Simple step-like analysis of images and approximation to geometric shapes with subsequent calculation give unacceptably high errors. The surface area of an internal, rigid, irregular surface area for illumination in AIOPDT can be accurately measured preoperatively by computer-assisted triangulation of CT images. The measurement of the surface area of an irregu- tissue-located drug. With a suitable combination of larly-shaped solid object is a difficult and complex drug concentration and light energy density selective problem (Fahle & Palm, 1983). The estimation of the necrosis of tumour can be achieved. At operation the surface area of various anatomical structures has been tumour is resected in the normal manner and then the attempted before (Batnitzky et al, 1982; Bulstrode et al, whole tumour bed (which is macroscopically normal) 1986), but existing techniques have not been rigorously should be irradiated with a uniform energy density of tested. Recently a need has arisen for the pre-operative light. It has been shown that microscopic tumour left at measurement of the surface area of structures within the the resection margin may be the cause of local recur- body: the technique of adjunctive intraoperative photo- rence (Quirke et al, 1986) and this will give rise to dynamic therapy (AIOPDT) (Allardice et al, 1992), a distressing local symptoms. Photodynamic therapy relatively new cancer therapy, demands that surface (PDT) should be particularly effective against micro- area be known.

Some structural characteristics and properties of a diverse paper selection were studied with the aim to create biodegradable polymer composites for packaging materials. Paper in such composites would serve as a reinforcement and biodegradable polymer as a matrix. Tensile and tear properties of the tested papers depended not only on paper density (or void content) but also on some other paper structure features. As polymers for composite production are applied from solution, the impact of solvent on the mechanical properties of paper was investigated.

In dry toner electrophotography, image fixing by roller fusing technology is affected by the process parameters, and by toner and paper properties. In this type of contact fusing, the fusing energy is applied in the form of pressure and conductive heat as a function of the dwell time determined by the process speed and fusing nip width. The present study was designed to provide a deeper understanding of the behavior of paper in a modified fusing nip with controlled speed and temperature. The effects of moisture content and coating color were examined as well, and some quality factors of toner images were correlated to the thermal behavior and bulk properties of the paper samples used in the experiment. In relation to electrophotography, the objective was to explore the role of paper in the fusing stage, and to show how different paper grades contribute to image quality at different fusing speeds and temperatures, which were the main fusing parameters controlled in the experimental setting. The results show that the thermal behavior of paper is strongly related to the paper mass expressed by grammage, and the thermal behavior is less sensitive to speed with increased paper density. Gloss and toner adhesion are affected by the thermal properties of paper. The experimental design, involving a wide range of fusing variables, confirmed the need to understand on the mechanism of toner fusing and the role of toner-paper thermal interactions more deeply. The thermally controlled fusing system used in this work was found to be useful in characterizing the influence of moisture content and coating color on the thermal behavior of paper and the quality of image fixing.

This paper presents a review of micromechanics models that have been used to predict the elastic and strength behavior of paper materials. The models discussed are based on a fiber network model that takes into account the properties of the fibers and the properties of the fiber-to-fiber bond.Elastic models are described for a range of paper density and basis weight ranging from tissue papers to paperboard materials. The effects of fiber curl for low density systems is discussed. Models for predicting both the initial modulus of the paper and the nonlinear elastic behavior for small finite strains is presented. Differences between tensile and compressive straining regimes are addressed.Limit load theory is discussed for predicting the strength of the network. Damage mechanics theory is employed to take into account hypothesized processes of fiber fracture and bond delaminations, and to relate the inelastic network micromechanics to the prediction of the strength of the material.

An extensive density study based on gamma‐gamma (or density) logs from 435 wells in western Canada was undertaken in an area extending from the Rocky Mountains in the west to longitude 100°W in the east and from the international boundary in the south to latitude 56°N in the north. The logs, with, total footage of about 814,000 ft, were subdivided into nearly 34,000 intervals for computer input. In this paper density is studied without separation of measurements according to lithology. Uncompensated density logs yield an average density for the whole basin which is lower by [Formula: see text] than that from compensated density logs. The weighted average densities in the Western Canada Basin established from compensated density logs are as follows: [Formula: see text] for the section above sea level, [Formula: see text] below sea level, and [Formula: see text] without regard to depth. Large density variations both horizontally and vertically are demonstrated on several contour density maps. The prevailing northwesterly contour trends indicated on maps of density and by some statistics coincide with the strike of the strata. Generally, density above sea level increases toward the Rocky Mountains, whereas below sea level no general rule is apparent. The linear correlation coefficient between density and depth based on all compensated density logs is 0.46, and the regression line of density D (in [Formula: see text]) on depth below sea level d (in feet) has the equation D = 2.372 + 0.000052d ± 0.21. The mean value of the correlation coefficient between density and depth calculated independently in single wells is 0.45, and a similarly established mean for density increments with depth is [Formula: see text] per 10,000 ft. However, both local (in single wells) and regional density sample distributions are most often skewed to the left which suggests that, in general, the vertical density gradient is higher at smaller depths than at larger depths.

STUDIES of the causes and mechanism of the failure of impregnated-paper insulation are commonly obscured by the burning due to the final complete breakdown. In a number of years of study of the more accessible properties of impregnated paper and their relation to stability and breakdown, constant attention has been given to the restriction of this burning and a nearer view of the beginnings of failure. Simple fuses and even rapid circuit breakers in the primary circuit of the testing transformer are of no avail. Some improvement is obtained by the use of a thyratron in the grounded lead of the sample with suitable connection to a rapid circuit breaker in the primary. But by far the best results, and indeed very complete success, have been reached by a method for detecting the first occurrence of gaseous ionization within the test specimen. This method is a development of the pioneer work of Paine1 and the subsequent applications of Arman and Starr and of Whitehead and Shaw,2 using resonance methods for following the oscillations which arise in the ionization of gas spaces in the insulation wall. New features which have been added are increased sensitivity, improved balancing of the Schering bridge for the frequency of maximum oscillations, the use of greater amplification, and a sensitive recording instrument for registering the first occurrence of internal ionization. The complete setup, as described in this paper, is called the “ionization recorder.” With this instrument it is possible to detect the beginnings of failure in a completely impregnated specimen initially free of gas spaces or voids, often to within one layer of the impregnated structure, and also to follow its growth, with interruption at any desired stage on the way to complete breakdown. So far, the instrument has been applied only to the study of the influence of paper density on dielectric strength and stability, and the comparative behavior of two types of paper and two types of oil. From the results it will be seen that a very intimate picture of breakdown and its causes is presented.

Pressure pulses of 8.2 × 107 dyn cm-2, each lasting for about 0.01 sec, were applied to paper, and the scattered light from it was measured simultaneously in order to study the response of pores in paper under dynamic conditions. During the compression phase the deformation in pore surface, i.e. the loss in fibre-air interface, is found to be linearly related to the square root of pressure, and the minimum pressure required to compress a paper to the non-porous state is estimated to be around 5 × 108 dyn cm-2, depending on the type of paper. The decompression curve, however, always follows a different path; thus, a cycle of compression and decompression shows large hysteresis. An approximate calculation is made of the energy loss per cycle, and this shows the associated temperature rise to be less than 1 degc. The delayed recovery from compression is large compared with the elastic recovery, but the permanent set is very small. Both the resistance of pores to compression and the energy loss per unit volume seem to be related to the paper density.

Analyses for Co, Zn, and Pb on mixed bed and SA-2 cation exchange resin-loaded paper disks in amounts approaching the theoretical limits of detection were attempted. Based on the results, the definition of limit of detection which requires a line intensity above background equal to three times the square root of the background, using a 10-min count, was modified to the line intensity above background equal to three times the standard deviation of the background counted for 10 min on a series of blank disks. Chemical precleaning of the disks and corrections for paper density were shown to be advantageous for work close to the limit of detection by lowering the background count and reducing the weight-corrected standard deviation.

A method of measuring line intensities in spectrochemical analysis is developed, based on the principle of visual comparison with standard density lines (standard paper density scale). The method gives results as accurate as those obtained by means of the densitometer (5%) ; it includes a correction for background intensity and it speeds up the quantitative analysis, as the qualitative inspection of the spectrum and the measurement of line intensities can be made simultaneously. The use of a densitometer is eliminated. Examples of analysis results and of the time necessary for quantitative analysis according to this method are given.

Research on the dielectric strength of high-voltage cables can be very conveniently carried out on "models". Either plate or cylindrical capacitors can be used for this purpose. This paper reports the results of many tests both at power frequency and at impulse, which have the purpose of investigating the separate and combined influence of a series of different factors affecting the dielectric strength of a fully impregnated paper insulation as used in high-voltage cables. The main factors investigated are the following: Paper impermeability, Paper density, Paper thickness, Oil viscosity, Oil pressure, Electrode surface shape, Electrode surface nature, Butt-space thickness, Butt-space position with respect to electrodes. Butt-space relative position. The paper ends with a comparison of results obtained on models and on actual oil-filled cables, which show a good agreement if certain assumptions are taken into consideration.

Paper properties determine the product application potential and depend on the raw material, pulping conditions, and pulp refining. The aim of this study was to construct mathematical models that predict quantitative relations between the paper density and various mechanical and optical properties of the paper. A dataset of properties of paper handsheets produced with pulps of Acacia dealbata, Acacia melanoxylon, and Eucalyptus globulus beaten at 500, 2500, and 4500 revolutions was used. Unsupervised classification techniques were combined to assess the need to perform separated prediction models for each species, and multivariable regression techniques were used to establish such prediction models. It was possible to develop models with a high goodness of fit using paper density as the independent variable (or predictor) for all variables except tear index and zero-span tensile strength, both dry and wet. info:eu-repo/semantics/publishedVersion