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This paper reports the temperature-dependence of methanol generation and the tensile index under ageing conditions for two paper/oil systems: one consisting of a standard wood Kraft paper and the other of a thermally-upgraded Kraft paper (TUK). A linear correlation between methanol and the tensile index for these paper/oil systems was observed in a previous study at 170 °C. In the current study, the correlation was extended to a large range of temperatures (150-190 °C). The experimental data were fitted with a modified Calvini's kinetic model, while the Arrhenius equation was used to model the kinetic of changes of the paper's mechanical properties during ageing. Good agreement with the temperature ( lnk vs. 1/ T) was observed for the rate constants of the chain-end group production, methanol formation, and the decrease of mechanical properties. The Arrhenius equation applied to this data grouping showed activation energy of 130 ± 29 kJ/mol for the decrease in mechanical strength of the standard Kraft paper, while the value was 118 ± 55 kJ/mol for the TUK paper. These values are of the same order of magnitude as those obtained in this study and in the literature for the depolymerization of cellulose and the generation of methanol that was reported. This confirmed the close relationship between cellulose depolymerization, methanol generation and the reduction of the paper's mechanical strength during ageing, dominated by the acid hydrolysis mechanism. The results, which can be seen as a benchmark and pave the way to further research, provide an opportunity for applying the proposed correlations to estimate the insulation condition in operating transformers. [ABSTRACT FROM AUTHOR]

Predicting breakthrough papers holds great significance; however, prior studies encountered challenges in this task, indicating a need for substantial improvement. We propose that the failure to capture the dynamic structural-evolutionary features of citation networks is one of the major reasons. To overcome this limitation, this paper introduces a new method for constructing citation cascades of focus papers, allowing the creation of a time-series-like set of citation cascades. Then, through a thorough review, three types of structural indicators in these citation networks that could reflect breakthroughs are identified, including certain basic topological metrics, PageRank values, and the von Neumann graph entropy. Based on the time-series-like set of citation cascades, the dynamic trajectories of these indicators are calculated and employed as predictors. Using the Nobel Prize-winning papers as a landmark dataset, our prediction method yields approximately a 7% improvement in the ROC-AUC score compared to static-based prior methods. Additionally, our method advances in achieving earlier predictions than other previous methods. The main contribution of this paper is proposing a novel method for creating citation cascades in chronological order and confirming the significance of predicting breakthroughs from a dynamic structural perspective. [ABSTRACT FROM AUTHOR]

In this paper, a finite element procedure is used to study the dynamic behaviour of a paper web in a free span between two rollers, including effects of transport velocity and surrounding air. The paper web is modelled as a three-dimensional orthotropic structure. The influence of air is accounted for by utilizing fluid–solid interaction analyses based on acoustic theory. The contribution of transport velocity is included through gyroscopic matrices and forces. The structural response on harmonic excitations has been studied using linear and non-linear models. Results show that air significantly reduces eigenfrequencies of the web. So called “edge-flutter” is nothing but the result of skew tension profile. Excessive web vibration can be eliminated by adjusting the web tension. [Copyright &y& Elsevier]

Studies of voltage-induced deflections in electroactive paper (EAPap) have been carried out. On the experimental side, measurements of bias-dependent deflections and strain, water absorption as a function of time, and relative humidity were obtained for the cellulose EAPap actuator. In addition, model simulations have also been carried out to probe and quantify the role of the various internal mechanisms responsible for the deflection. Our simulation predictions yield good agreement with the measured deflection data for the EAPap. The modeling suggests that internal ion content and its migration, water absorption leading to a nonuniform permittivity, random variations in the transverse piezoelectric-coupling coefficient d31,i, and the modulus of elasticity all collectively contribute to the EAPap deflection electrophysics. It also appears that higher sensitivity, with a minimal bias dependence, could be achieved by deliberately adding ions during EAPap processing. [ABSTRACT FROM AUTHOR]

A portable fiber-optic spectroscopic system (TRANSPEC) has been developed for non-destructive measurement of aged transformer insulating paper. Following successful measurement of degree of polymerization (DP) of a range of transformer-aged paper samples, the system has now been shown to separate the oil and paper information for measurement of DP in oil-wetted paper samples. In addition, the system has been shown to be capable of the prediction of both oil and water content of paper to a high accuracy, and is also capable of identifying and quantifying different water species. Spectroscopic measurements have been used together with gravimetric water adsorption measurements to investigate the kinetics of uptake of water vapour into paper from air in the case of nominally dry and oil-impregnated samples. Relationships between water adsorption parameters and properties of the paper insulation have also been investigated using measurements under controlled conditions. [ABSTRACT FROM AUTHOR]

Let X be a projective variety of dimension n ≥ 1 over an algebraically closed field of arbitrary characteristic. We prove a Fujiki–Lieberman type theorem on the structure of the automorphism group of X. Let G be a group of zero entropy automorphisms of X and G 0 the set of elements in G which are isotopic to the identity. We show that after replacing G by a suitable finite-index subgroup, G / G 0 is a unipotent group of the derived length at most n − 1. This result was first proved by Dinh et al. for compact Kähler manifolds. [ABSTRACT FROM AUTHOR]

The article presents a study of the kinetics of the formation of acetic and formic acid during the accelerated ageing process determined by customized ASTM D 6819-02 procedure. Newsprint paper was used in accelerated ageing at 98 degrees Celsius and 50% RH for 60 days. Results showed that the brittleness index uttered as embrittlement due to paper degradation is linked with the increase in the concentrations of carboxylic acids and the moral ratio of acetic acid to formic acid concentration.

This paper brieffy overviews some recent and very fresh results on a rather new class of dynamic optimization problems governed by the so-called sweeping (Moreau) processes with controlled moving sets. Uncontrolled sweeping processes have been known in dynamical systems and applications starting from 1970s while control problems for them have drawn attention of mathematicians, applied scientists, and practitioners quite recently. We discuss here such problems and major results achieved in their theory and applications. [ABSTRACT FROM AUTHOR]

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

A rule-based expert system for the integrated control and supervision of the dry-end sections of a paper machine is proposed. This. system is capable of recognizing all the normal and abnormal changes in process operating conditions, including acceleration of sections, threading of paper sheet, nip pressure activation, activation and deactivation of tension control loops, change of parent roll, and sheet break. A core part of the system is the supervision of the sensorless tension control of the dry-end sections, assuring its long-term stability. [ABSTRACT FROM AUTHOR]

This document is a summary of selected topics from the 29th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS) held in Siheung, Korea in July 2023. The conference focused on the dynamic aspects of reactive systems and included presentations on explosions, detonations, ignition, turbulent combustion, and other topics in combustion. The current issue of the journal Shock Waves includes ten papers that were presented at the conference, covering areas such as shock tube design, shock wave methane pyrolysis, detonation physics, and rotating detonation engine propulsion systems. The papers originated from China, India, Japan, Poland, and the USA. The authors and reviewers are thanked for their contributions to this issue. [Extracted from the article]

Forthcoming smart energy era is in strong pursuit of full-fledged rechargeable power sources with reliable electrochemical performances and shape versatility. Here, as a naturally abundant/environmentally friendly cellulose-mediated cell architecture strategy to address this challenging issue, a new class of hetero-nanonet (HN) paper batteries based on 1D building blocks of cellulose nanofibrils (CNFs)/multiwall carbon nanotubes (MWNTs) is demonstrated. The HN paper batteries consist of CNF/MWNT-intermingled heteronets embracing electrode active powders (CM electrodes) and microporous CNF separator membranes. The CNF/MWNT heteronet-mediated material/structural uniqueness enables the construction of 3D bicontinuous electron/ion transport pathways in the CM electrodes, thus facilitating electrochemical reaction kinetics. Furthermore, the metallic current collectors-free, CNF/MWNT heteronet architecture allows multiple stacking of CM electrodes in series, eventually leading to user-tailored, ultrathick (i.e., high-mass loading) electrodes far beyond those accessible with conventional battery technologies. Notably, the HN battery (multistacked LiNi0.5Mn1.5O4 (cathode)/multistacked graphite (anode)) provides exceptionally high-energy density (=226 Wh kg−1 per cell at 400 W kg−1 per cell), which surpasses the target value (=200 Wh kg−1 at 400 W kg−1) of long-range (=300 miles) electric vehicle batteries. In addition, the heteronet-enabled mechanical compliance of CM electrodes, in combination with readily deformable CNF separators, allows the fabrication of paper crane batteries via origami folding technique. [ABSTRACT FROM AUTHOR]

The weak AC grid in a modular multilevel converter modular multilevel converter based high voltage direct current (MMC‐HVDC) receiving‐end system requires faster reactive power support from the receiving‐end MMC. However, under the MMC traditional constant AC voltage dual‐loop control strategy, the increase in MMC's reactive power support speed will reduce the system stability. The reactive power cascade control strategy is a novel MMC control strategy. The analysis in this paper demonstrates that it possesses advanced performance under faster reactive power support, which is required by the MMC connected to a weak AC grid, but, some of its control links and operations can cause impacts exceeding that a weak AC grid can undertake. To solve this problem, based on the original control strategy, this paper proposes an improved reactive power cascade control strategy for weak AC grid conditions. The complete framework and the detailed design of primary control links of the improved cascade control strategy are displayed in this paper. Finally, a digital simulation has been conducted to validate the analysis and the proposed improved control strategy in this paper. [ABSTRACT FROM AUTHOR]

We introduced a strategic "Kinetic Diffusion Multiple" (KDM) that undergoes interdiffusion annealing followed by realistic thermal treatment. The blended spectra of phases and microstructures subjected to treatment in deeply grooved composition gradients enables the microstructure and micromechanical properties of structural materials to be surveyed by high-spatially resolved micro-analysis along the composition arrays. The KDM was demonstrated as a robust high-throughput methodology that enables rapid screening of the composition-microstructure-micromechanical/properties relationships for different metallic materials. It has also proven great success at elucidating the lasting effects of alloying elements and diffusion flux on microstructure, micromechanical properties, phase transformation, and their interrelationships as a whole. [ABSTRACT FROM AUTHOR]

In this work, the influences of the air temperature and velocity on the drying kinetics of recycled paper pulp were analyzed. The increase of both variables positively influences the process, concerning the final moisture content and the drying time. However, optical microscopy and visual observation showed worse quality of the paper for drying conditions of high air temperature and velocity, presenting less uniformity and overdried surfaces. The dryer energy efficiency was evaluated by performance parameters and the results were compared with the ones obtained for other types of industrial paper dryers, presenting good agreement. [ABSTRACT FROM AUTHOR]

Paper mill sludge is characterized by high concentrations of organic matter and lime and very low concentrations of heavy metals and organic chemicals. Interest in the recycling of paper mill residuals in developing countries is vital because the use of lime and fertilisers by small farmers is financially prohibitive. The effects of paper pulp sludge and lime on the dynamics of soil nutrients was studied in the laboratory using columns of mixed samples of top soil from three tropical acid soils (Kandiudult). The soil columns were leached over a period of 90 days with de-iomzed water in amounts equivalent to the annual rainfall of the sampling site. To assess the amount of nutrient that may become available to plants, NH4OAc-EDTA pH 4.65 soil extractant was used. For all soils, application of paper pulp sludge or lime to tropical acid soils generally resulted in an initial flush and increased concentrations of Ca, Mg, SO 4 dissolved organic carbon (DOC) and inorganic carbon in soil leachates. Compared with liming, application of paper pulp sludge reduced NO3 leaching. The amount of leached Ca, DOC and inorganic carbon (mainly HCO 3-) increased substantially with the addition of paper pulp sludge or lime. In relation to nutrients, the most meaningful amendment effect that persisted after leaching was a substantially increased available Ca in the treated soil. In addition to increasing Ca levels, the addition of paper pulp sludge increased the concentrations of leached and available Ca. To sustain yield increase with paper pulp sludge, calculation of the optimum quantity to be returned to the soil should be based on losses of Ca by leaching and by plant uptake. [ABSTRACT FROM PUBLISHER]

Rheological properties of fiber/polymer suspensions and dynamic mechanical analysis (DMA) of paper sheets containing the same polymers were measured. Correlations between viscoelastic properties of suspensions and strength of paper sheet are presented. Rheological properties of suspensions of microfibrillar cellulose (MFC) and a set of water soluble polymers were measured. Rheological properties of these complex fluids vary considerably depending on the added polymer. A suspension of fiber and carboxymethyl cellulose (CMC) exhibits a viscosity higher than the sum of the viscosity of the individual components in the suspension. In contrast, when cationic starch (CS) is used together with the fiber, the yielding behavior rather than the viscosity is characteristic of the suspension. Dynamic mechanical properties of paper sheets containing CMC or CS as additives were studied at different humidity levels. Different yielding behavior observed in oscillatory rheology can be correlated with straining behavior in dynamic mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [ABSTRACT FROM AUTHOR]

Abstract: This paper compares the influence of the molecular weight of polylelectrolytes forming polyelectrolyte multilayers (PEM) on wood fibers on adhesion and paper strength. Sheets were made from fibers treated with poly(allylamine hydrochloride) (PAH)/poly(acrylic acid) (PAA) of molecular mass 70,000 and 240,000, respectively, and of poly(dimethyldiallylammonium chloride) (PDADMAC)/poly(styrene sulfonate) (PSS) of molecular mass 30,000 and 80,000, respectively. The results were compared to what has recently been reported for PEM formation on fibers using a low-molecular-mass combination of PAH and PAA and a high-molecular-mass combination of PDADMAC/PSS. There was a less significant improvement in the case of the low-molecular-mass PDADMAC/PSS and the high-molecular-mass PAH/PAA. The adsorbed amounts of PAH and PDADMAC were also determined, showing a lower adsorbed amount of the low-molecular-mass PAH than of the high-molecular-mass PDADMAC. The amount of low-molecular-mass PDADMAC was similar to that found for high-molecular-mass PDADMAC/PSS. Individual fibers were partly treated and studied, showing a less significant decrease in wettability with low-molecular-mass PDADMAC/PSS than with the high-molecular-mass combination. The effect of the molecular weight on the adhesion was discussed in terms of the structure and wettability of the PEMs. [Copyright &y& Elsevier]

The kinetics of the spontaneous, proton- and AlIII-catalysed hydrolyses of the C1—O4′ bond in 1,5-anhydrocellobiitol have been measured at elevated temperatures (125.0–220.0 °C). Data for the first two processes extrapolate to the expression k = (8.6 ± 2.1 × 10–16) + (1.4 ± 0.2 × 10–9-pH) s–1 at 25 °C. These room-temperature figures were used to model cellulose depolymerization by the af Ekenstam equation. The spontaneous process is too slow to contribute to loss of paper strength on aging, and even the acid-catalysed process is significant only below ~pH 4.0. However, the spontaneous hydrolysis readily accounts for the reduction of cellulose degree of polymerization (DP) during alkaline (e.g., kraft) pulping of cellulose fibres. Efficient electrophilic catalysis by AlIII was observed at 150.0 °C in 0.1 mol/L succinate buffers of room temperature pH 3.05 and 3.35 (k2 = 8.1 ± 0.4 × 10–3 and 4.2 ± 0.2 × 10–3 (mol/L) –1 s–1, respectively). The apparent activation energy of the AlIII-catalysed process was 31 ± 4 kJ mol-1, lower than that of the proton-catalysed path, suggesting the electrophilic catalysis increases in importance as the temperature approaches ambient. Consequently, it appears that the culprit in the impermanence of “rosin-alum” -sized paper is AlIII, directly acting as a Lewis acid, not the AlIII hydration sphere as a Brønsted acid. Conservation measures should either address this or be generic (e.g., low-temperature storage). [ABSTRACT FROM AUTHOR]

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

Hardware-in-the-loop (HIL) testing is a popular control system testing method because it bridges the gap between modeling/simulation and experiments. Instead of designing a full hardware-based experiment to validate the results of a simulation, the plant hardware can be replaced with an emulator device that responds to exogenous inputs and effectively emulates the dynamic behavior of a system. This approach can be more cost-effective and modular, since the emulated plant system can be modeled in a simulation environment, implemented on a simplified piece of hardware and changed quickly without having to fabricate new parts. This paper develops the hardware and control scheme for a certain type of HIL device called a dynamic load emulator that consists of a 1-DOF linear hydraulic dynamometer equipped with in-line sensing to measure both its own position and the force exerted on it by a device-under-test. This measured force is passed to a real-time model of the emulated dynamic system. The model outputs the emulated system position, and a closed-loop controller is used to emulate this position. The emulator controller incorporates both model-based feedforward and standard feedback PI control. This paper characterizes the dynamometer-based dynamic load emulator and its controller, determining its hardware limitations and validating its capabilities when experiencing a force input from a linear spring with known parameters. Additionally, this paper demonstrates the ability of the emulator to represent the dynamics of a 1-DOF robotic joint when actuated by a pair of fluidic artificial muscles (FAMs). The primary contribution of this work is to allow for more comprehensive testing of FAM configurations, topologies, and controllers for a wide range of parameters, because the same hardware can be used to emulate multiple systems. As a result, this work will lead to more cost-effective, time-efficient, and energy-efficient designs of robotic systems and the FAMs used to actuate them. [ABSTRACT FROM AUTHOR]

The article comments on the papers "A Novel Semi-Empirical Tyre Model For Combined Slips," and "A Semi-Empirical Dynamic Tire Model For Combined-Slip Forces," by M. Gäfvert and J. Svendenius. The author reveals that the focus of the works is the determination of tire shear forces under combined longitudinal and lateral slips using pure slip testing. The author points out that the researchers have not seen the connection of their extensive work and the previous papers.

We argue that a piece of paper, of thickness T and width W , can be folded a maximum number N ?=?0.962 ln( f ? W / T ) times, where f is a factor of order unity, determined by mechanical constraints. N typically takes a value of around six. [ABSTRACT FROM AUTHOR]