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This paper evaluates the environmental impacts of different alternatives for handling of sludge from paper and pulp mills in Sweden, using Life Cycle Assessment (LCA). The common practice of incineration of biosludge with energy recovery followed by landfilling of ash (System A) was compared with the alternative of digesting sludge anaerobically to produce biogas using different digestate residue management options. The digestate produced from anaerobic digestion (AD) was assumed to be incinerated for heat energy recovery in System B or pyrolyzed for biochar production in System C to be mixed with forest soils. The impact categories considered in this work are climate change, non-renewable energy use, mineral extraction, aquatic ecotoxicity, carcinogens and non-carcinogens. The LCA results demonstrate that the two proposed systems significantly reduce the environmental impacts of biosludge management relative to incineration. An 85% reduction in the aquatic ecotoxicity impact is achieved in System C, due to the reduced mobility of heavy metals in biochar relative to ash. System C, on the whole, outperformed the other two, leading the authors to the recommendation that the use of pulp and paper mill biosludge in biogas-biochar production systems is preferable to merely recovering energy from it.

Waste-to-energy or value-added products have been increasingly considered in many pulp and paper mills (PPMs) worldwide. However, developing appropriate conversion technologies is a major challenge in transforming PPMs wastes into biofuels or value-added biomaterials. In the present study, a long-term (320 d) anaerobic digestion of primary sludge of a thermomechanical pulp mill (TMP) was carried out for the first time in a thermophilic anaerobic membrane bioreactor (ThAnMBR). Effect of organic loading rate (OLR) in the range of 2.5–6.8 kg-COD/m3 d and hydraulic retention times (HRT) of 3–8 d on the process performance was investigated. Under various OLRs, stable biogas productions were obtained, and the best results were achieved with lower OLR (2.5 kg-COD/m3 d) and higher HRT (8 d), at biogas yields of 189 L biogas/kg MLSS fed. However, it was found that biogas production and sludge biomass degradation decrease when the organic loading rate increases. The proportion of sludge reduction ranged from 28.9 to 46.7% depending on the applied OLRs. Despite varying OLRs, stable membrane performance was obtained, where the required membrane flux was easily maintained during the reactor operation. In this study, also the properties of digestate and membrane permeates were studied under different operating conditions, and they fluctuated to some extent with OLR. ThAnMBR is a promising new technology for pulp and paper mill primary sludge treatment.

Valorization of industrial low-value side-streams are of great interest, contributing to boosts in the circular economy. In this context, lignin side-streams of the pulp and paper industry were oxypropylated to produce biobased polyols and tested in the synthesis of rigid polyurethane (RPU) foams. E. globulus lignins, namely a lignin isolated from an industrial Kraft black liquor and depolymerized lignins obtained as by-products of an oxidation process, were used. RPU foams, synthesized with 100% lignin-based polyols and using a 1.1 NCO/OH ratio, were characterized concerning apparent density, morphology, thermal conductivity, thermal stability, and heat release rate (HRR). Foams containing the lignin-based polyols presented densities varying from 44.7 to 112.2 kg/m3 and thermal conductivity in the range of 37.2–49.0 mW/mK. For the reference foam (sample produced with 100% wt. Daltofoam TP 32015 polyol), values of 70.9 kg/m3 and 41.1 mW/mK were obtained, respectively. The achieved results point out the viability of using the generated lignin-based polyols at 100% content in RPU foams, mainly when depolymerized lignins are used. Moreover, fire retardancy was favored when the lignin-based polyols were introduced. The proposed strategies can contribute to establishing the integrated pulp and paper biorefinery concept where material synthesis (polyols and RPU foams) can be combined with chemical production (vanillin and syringaldehyde). Foundation for Science and Technology (FCT, Portugal) and FEDER under Program PT2020 for financial support to CIMO (UIDB/00690/2020), and to UIDB/50020/2020 of the Associate Laboratory LSRE-LCM—funded by national funds through FCT/MCTES (PIDDAC); national funding by FCT, PI, through the institutional scientific employment program contract for Isabel P. Fernandes. This work was carried out under the Project No. 33969 Bioblocks—Design of biobased products from renewable lignocellulosic sources as precursors for the bioindustry of chemical synthesis and biomaterials—financed by FEDER through the Operational Program for Competitiveness Factors (POFC) and QREN. To COST Action LignoCOST (CA17128) supported by COST (European Cooperation in Science and Technology). info:eu-repo/semantics/publishedVersion

The dramatic fluctuations of oil cost and climate change have together concentrated political and scientific attention on the search of alternative fuels. The aim of this work is to recycle waste p...

The metal casting industry, Nitikan is a micro business whose production process is carried out manually. The equipment used is simple and without considering the user's health. This can be seen in the product finishing process that uses a sanding machine. The equipment is not designed according to the user's posture so the operator bends in doing work movements, of course this is very risky to experience lower back pain injuries. This study aims to analyze the work activities of the finishing process using the Rapid Entire Body Assessment (REBA) and Rapid Upper Limb Assessment (RULA) approach and design work tools that can be applied to improve work posture. The results of data processing and analysis obtained a Rapid Entire Body Assessment score on a sandpaper machine single head of 5 and a Rapid Upper Limb Assessment score of 4, the score indicates that the work position has the potential to experience a risk of low back pain, so there must be an improvement in work posture. Work posture improvement is done by designing a tool in the form of a sandpaper machine that takes into account ergonomic dimensions to reduce the risk of lower back injury. The final result after the improvement is obtained Rapid Entire Body Assessment score of 3 and Rapid Upper Limb Assessment score of 4. This shows that the risk of lower back injuries can be minimized.

In the present work, the production of enzymatic cocktails from different Aspergillus species grown in eucalyptus chips has been investigated. In addition, hydrolysis of the eucalyptus chips and pa...

Unprinting of paper can reduce multiple life-cycle stages in the recycling of paper to yield significant environmental impact. Laser-unprinting has been demonstrated for uncoated paper but causes significant damage to coated paper. This work explores a scalable optical (non-laser) process for unprinting coated paper. Printed coated paper is exposed to pulsed broad-spectrum Intense Pulsed Light (IPL) from a xenon lamp and the toner is then removed by dabbing gently with an ethanol wipe. While black toner is easily unprinted, unprinting of colored prints (red, blue, green) is best realized by incorporating an initial overprint of black toner. An unprinting throughput on the order of mm2/s is achieved. Three distinct regimes of unprinting are identified based on the extent of toner removal and damage of the paper. The optical properties of the unprinted paper, characterized via UV–Visible spectrophotometry, are correlated to these regimes to understand the potential for in-situ optical process monitoring. Scanning Electron Micrography and Fourier-Transform Infrared Spectroscopy are performed to understand the underlying mechanisms that govern the occurrence of the different unprinting regimes. Further, the potential impact of the developed approach on recycling of paper is discussed in the context of the capabilities of current optical unprinting approaches and the potential elimination of life-cycle stages in conventional paper recycling.

The hypothesis of this paper is that writers with similar academic backgrounds express personal attitudes in English and in Spanish differently in research papers. Thus, the main objectives are, first, to study the differences in the use of attitude devices in Spanish and English academic discourse; second, to compare the results in the different sections of articles; and finally to study the positive or negative semantic implications of the lexical items by carrying out a sentiment analysis. To this end, fifteen Spanish industrial engineering papers were compared with fifteen English industrial engineering papers. The results showed that there are in fact differences in the way academic writers communicate attitude, but the sentiment analysis revealed that neutral lexical items were the most commonly used in engineering research papers. Even though engineering researchers share the knowledge of the specialist content and the academic style of expressing their thoughts, personal attitudes were expressed in different ways in Spanish and in English.

The recycling of waste paper has been an effective way to achieve the environmental-friendly growth of papermaking industry. Focusing on the mixed-pulping process which has been generally employed, to ensure the required properties of the deinking pulp (DIP) and minimize the purchase cost of waste paper, an intelligent model scheduling the mixing ratio of waste paper was developed in the study. Primarily, driven by the field data of mixing ratio of waste paper and DIP properties, the prediction models of DIP properties were developed by SVM, GA-SVM, and BP-NN algorithms. Subsequently, based on the best prediction model, the scheduling model for the mixing ratio of waste paper was set up by NSGAII algorithm. The experimental results showed that, based on the obtained best BP-NN prediction model of DIP properties, the developed NSGAII scheduling model for the ratio of waste paper could achieve excellent scheduling results under the rigorous constraints and multi-objective. Compared with the previous study, the developed prediction and scheduling models in this study reduced the purchase cost of waste paper by 2.16%, and improved the acceptable proportion of DIP property from 56.07% to 100%.

We have studied the surface structure of tamper-proof paper with positive and negative watermarks at different scales ‒ from a micrometer to a nanometer level, by using the methods of contact profilometry and atomic force microscopy. Experimental research has confirmed that the structural parameters of the tamper-proof paper's surface differ at regions with and without watermarks. The results of measurements by a contact profilometer have made it possible to trace a correlation between values of the profile's mean arithmetic deviation and the presence of watermarks. It was determined that the value for the profile's largest height does not depend on a measurement region, which could be related to the chaotic arrangement of fibers and particles of the filler in the paper bulk that protrude above the profile's line. By analyzing the value of the profile's mean arithmetic deviation obtained by using a method of atomic-force microscopy, it was found that for regions with negative watermarks it is larger than that for regions with positive watermarks. The dependence of the profile's largest height on measurement region is not clearly observed. This may be due to that the size of the examined region (3,000×3,000 nm) covers only part of the pulp fibers. Thus, the results of our analysis allow us to argue that both methods are suitable for estimating the characteristics of paper's surface, and determine the character of interaction between a given type of paper and printing inks during printing process. In particular, it has been established that the method of profilometry makes it possible to determine parameters of the paper's surface profile, formed in a certain way, while the atomic force microscopy method allows analysis of the morphology of its components, located at the surface (fibers, filler's particles, etc.). The availability of information on the structural properties of paper makes it possible to predict the quality of printing reproduction, specifically clearness of reproduction of thin guilloche lines on watermarks, which is relevant because it prevents flaws in printing products for special purposes.

Industrialization and urbanization are the key drivers to threaten the environmental quality and natural resources. Traditionally, pulp and paper industry has been highly reliant on forest based resources for its escalation. Shortage of forest based raw materials, strict environmental regulations and policies have compelled the industry to seek for alternate raw materials for its production. Mills are now focusing on exploring the potential of different agro wastes such as cereal straws and bagasse etc. In present research, sugarcane trash, one of the most abundant agro residues in India, was investigated for its capability in pulping and bleaching. Chemical characterization of sugarcane trash showed that it contains 40.4% cellulose, 33.2% hemicelluloses, 17.4% lignin and 6.45% ash content with 2.76% silica. To cook sugarcane trash with soda pulping method, 14% alkali charge, 15 min time and 162 °C temperature was found to be optimum and pulp of kappa no. 19.8 was prepared that exhibited good strength properties. Bleaching of pulp was carried out using elemental chlorine (Cl2), hypochlorite and chlorine dioxide (ClO2) based sequences. Replacement of Cl2 with ClO2 has significant impact on strength properties and effluent characteristics. Oxygen delignification stage was incorporated prior to ClO2 that resulted in improved optical properties of pulp with noticeable reduction in wastewater load. This paper elaborates the need of using sugarcane trash in paper mills with environment friendly pulping and bleaching processes to combat with the problem of waste management, wastewater load reduction during bleaching and substitute for wood based raw materials in papermaking.

The effects of paper waste (PW) ratio on biogas production by two-stage thermophilic anaerobic co-digestion (coAD) of food waste (FW) and PW, two main components of organic fraction of municipal solid waste, were evaluated in lab-scale continuously stirred tank systems with semi-continuous feeding. Four PW ratios (0, 20, 40, and 50%) were studied in the test. The experimental results showed the two-stage thermophilic coAD could operate stably after an adjustment period at all PW ratios. Although the increase of PW ratio decreased methane content, production and yield, reaction rates of four AD steps, it could increase the methane production of substrate when the FW was fixed. The pH, total volatile fatty acids, total alkalinity, and total ammonium of the sludge in the second stage of AD, also decreased with the increase of PW ratio in the test. The change of the substrate's organic composition, increase of carbohydrate and decrease of protein and lipid, were the main reason for the decrease of methane content, production and yield and changes of the second stage sludge characteristics. An apposite PW ratio (PW-20%) could enhance the degradation of matters (TS, VS and TCOD).

This paper examines the mechanical properties and durability of recycled aggregate concrete (RAC) containing 100% coarse recycled concrete aggregate (RCA) and industrial by-products. The by-products, including waste paper sludge ash (PSA), fly ash (FA), silica fume (SF), and metakaolin (MK) of different proportions (5%, 10%, 15%) in RAC, were used in two methods: replacement and addition methods. The use of by-products (mineral admixtures) to mitigate the low quality of RAC was demonstrated through experimental outcomes in this study. The addition of industrial by-products was presented as a promising alternative for the addition of more Portland cement in RAC to enhance RAC's quality. The results showed that the strength and durability of RAC containing mineral admixtures in the addition method were higher than the addition of more cement or the replacement method. Notably, PSA considerably improved the mechanical properties of RAC at an early age, and it substantially improved the resistance of RAC to acid and sulfate attacks. At 90 days, FA and MK improved mechanical properties of RAC greater than SF and PSA did. Among combinations, the proportions of by-products in RAC of 5% PSA, 10% SF, 15% MK and 15% FA can produce the highest performance of RAC with 100% coarse recycled concrete aggregate (RCA).

The paper drying process has the highest level of energy consumption in the pulp and paper production process. Analysis and optimization of the energy system during the paper drying process is critical for improving the energy efficiency of the entire paper mill. In the existing model for the paper drying process, the solution requires accurate boundary conditions such as the air temperature and humidity of the pocket area and the cylinder surface temperature, which are very difficult to obtain in the papermaking process. This can result in significant deviations between the model solution and the actual production process. This paper focuses on the single-tier dryer cylinder-based paper drying process that has been widely used with high-speed papermaking machines in recent years. A mathematical model is proposed based on real-time data. The verification via industrial production demonstrates that the proposed model is reliable for the paper drying process. Based on the simulation results, two optimization operations have been proposed. The energy consumption decreases from 1.51 t steam/t paper to 1.44 t steam/t paper, 4.6% of the steam and 1.26 × 106 RMB can be saved for a medium-scale paper mill with the annual production capacity of 105 t paper.

The effect of paper thermal destruction on its luminescence spectra and luminescence excitation spectra in the spectral ranges of 400-550 nm and 250-450 nm, respectively, was studied. It is proposed to use the characteristic changes in the intensity and shape of the luminescence spectra as a criterion for the state of paper insulation of power transformers. On the basis of the analysis performed, it was concluded that when luminescence is excited at a wavelength of 360 nm, none of the main components of the paper can contribute to the recorded luminescence spectra. It is assumed that the resulting luminescence spectra are due to the emission of various impurities that enter the paper during its production.

Pulp and paper industry is one of the high priority sectors that generates large amount of solid (sludge) and liquid (paper mill effluent) wastes. Making use of this huge quantity of paper mill sludge (PMS) in an environment friendly manner is challenging and cost involving. Similarly the present wastewater treatment strategies based on physical and chemical methods encounter certain serious setbacks including secondary pollution generation with expensive mode of abatement processes. The present study aims at a “waste treats waste” strategy for the bioremediation of paper mill effluent in fluidized bed reactor (FBR) using another waste of the same industry, PMS as immobilizing matrix for Planococcus sp. TRC1, a wastewater bacterial isolate. This study simultaneously explores this isolate for the yellowish orange pigment it produces (2.3 ± 0.2 mg/gm of dry bacterial biomass) and characterizes it as a member of the pharmacologically important carotenoid pigment family via UV-Vis spectrophotometry, TLC, FT-IR and 13C NMR. The antioxidant potential of this pigment was studied by DPPH assay (IC50 = 33 ± 0.4 μg/ml) and H2O2 assay (IC50 = 147.4 ± 2.2 μg/ml). In FBR, the PMS immobilized bacteria showed removal of phenol, lignin, colour and COD from the effluent by 96%, 74%, 81% and 85% respectively after 60hr of treatment. The experimental data on immobilization fitted well with pseudo second-order (R2 = 0.955) and Freundlich adsorption isotherm (R2 = 0.996) models. The alterations in PMS before and after bacterial immobilization, as revealed by SEM and FT-IR, depicted the success of PMS as immobilization matrix. Phytotoxicity (90% seed germination) and mutagenicity studies confirmed that the treated effluent was substantially less toxic than its raw state. This study highlights a novel utilization possibility of PMS in an eco-friendly and economic way as immobilization matrix for Planococcus sp.TRC1 for paper pulp mill effluent treatment along with production of carotenoid pigment from this potential bacterial isolate as value added product.

The Gaussian wiretap channel with noncausal state interference available at the transmitter, which is also called the dirty paper wiretap channel (DP-WTC), has been extensively studied in the literature. Recently, it has been shown that taking actions on the corrupted state interference of the DP-WTC (also called the action-dependent DP-WTC) helps to increase the secrecy capacity of the DP-WTC. Subsequently, it has been shown that channel feedback further increases the secrecy capacity of the action-dependent DP-WTC (AD-DP-WTC), and a sub-optimal feedback scheme is proposed for this feedback model. In this paper, a two-step hybrid scheme and a corresponding new lower bound on the secrecy capacity of the AD-DP-WTC with noiseless feedback are proposed. The proposed new lower bound is shown to be optimal (achieving the secrecy capacity) and tighter than the existing one in the literature for some cases, and the results of this paper are further explained via numerical examples.

Rapid increase in scholarly publications on the web has posed a new challenge to the researchers in finding highly relevant and important research articles associated with a particular area of interest. Even a highly relevant paper is sometimes missed especially for novice researchers due to lack of knowledge and experience in finding and accessing the most suitable articles. Scholarly recommender system is a very appropriate tool for this purpose that can enable researchers to locate relevant publications easily and quickly. However, the main downside of the existing approaches is that their effectiveness is dependent on priori user profiles and thus, they cannot recommend papers to the new users. Furthermore, the system uses both public and non-public metadata and therefore, the system is unable to find similarities between papers efficiently due to copyright restrictions. Considering the above challenges, in this research work, a novel hybrid approach is proposed that separately combines a Content Based Filtering (CBF) recommender module and a Collaborative Filtering (CF) recommender module. Unlike previous CBF and CF approaches, public contextual metadata and paper-citation relationship information are effectively incorporated into these two approaches separately to enhance the recommendation accuracy. In order to verify the effectiveness of the proposed approach, publicly available datasets were employed. Experimental results demonstrate that the proposed approach outperforms the baseline approaches in terms of standard metrics (precision, recall, F1-measure, mean average precision, and mean reciprocal rank), indicating that the proposed approach is more efficient in recommending scholarly publications.

International audience; This paper focuses on the problem of the hierarchical multi‐label classification of research papers, which is the task of assigning the set of relevant labels for a paper from a hierarchy, using reduced amounts of labelled training data. Specifically, we study leveraging unlabelled data, which are usually plentiful and easy to collect, in addition to the few available labelled ones in a semi‐supervised learning framework for achieving better performance results. Thus, in this paper, we propose a semi‐supervised approach for the hierarchical multi‐label classification task of research papers based on the well‐known Co‐training algorithm, which exploit content and bibliographic coupling information as two distinct papers' views. In our approach, two hierarchical multi‐label classifiers, are learnt on different views of the labelled data, and iteratively select their most confident unlabelled samples, which are further added to the labelled set. The success of our suggested Co‐training‐based approach lies in two main components. The first is the use of two suggested selection criteria (i.e., Maximum Agreement and Labels Cardinality Consistency) that enforce selecting confident unlabelled samples. The second is the appliance of an oversampling method that rebalances the labels distribution of the initial labelled set, which reduces the reinforcement of the label imbalance issue during the Co‐training learning. The proposed approach is evaluated using a collection of scientific papers extracted from the ACM digital library. Performed experiments show the effectiveness of our approach with regards to several baseline methods.

Background There has been growing interest in the development of waste-specific decay factors for estimation of greenhouse gas emissions from landfills in national greenhouse gas inventories. Although engineered wood products (EWPs) and paper represent a substantial component of the solid waste stream, there is limited information available on their carbon dynamics in landfills. The objective of this study was to determine the extent of carbon loss for EWPs and paper products commonly used in Australia. Experiments were conducted under laboratory conditions designed to simulate optimal anaerobic biodegradation in a landfill. Results Methane generation rates over incubations of 307–677 days ranged from zero for medium-density fibreboard (MDF) to 326 mL CH4 g−1 for copy paper. Carbon losses for particleboard and MDF ranged from 0.7 to 1.6%, consistent with previous estimates. Carbon loss for the exterior wall panel product (2.8%) was consistent with the expected value for blackbutt, the main wood type used in its manufacture. Carbon loss for bamboo (11.4%) was significantly higher than for EWPs. Carbon losses for the three types of copy paper tested ranged from 72.4 to 82.5%, and were significantly higher than for cardboard (27.3–43.8%). Cardboard that had been buried in landfill for 20 years had a carbon loss of 27.3%—indicating that environmental conditions in the landfill did not support complete decomposition of the available carbon. Thus carbon losses for paper products as measured in bioreactors clearly overestimate those in actual landfills. Carbon losses, as estimated by gas generation, were on average lower than those derived by mass balance. The low carbon loss for particleboard and MDF is consistent with carbon loss for Australian wood types described in previous studies. A factor for carbon loss for combined EWPs and wood in landfills in Australia of 1.3% and for paper of 48% is proposed. Conclusions The new suggested combined decay factor for wood and EWPs represents a significant reduction from the current factor used in the Australian greenhouse gas inventory; whereas the suggested decay factor for paper is similar to the current decay factor. Our results improve current understanding of the carbon dynamics of harvested wood products, and allow more refined estimates of methane emissions from landfills. Electronic supplementary material The online version of this article (10.1186/s13021-018-0115-3) contains supplementary material, which is available to authorized users.

The textile industry is resource-intensive, which has a significant impact on global emissions and waste pollution. To meet the demand of textiles over a third of fibres used in manufacturing are sourced from fossil fuels. As the global demand for textiles continues to grow, manufacturers are having to seek innovative approaches to providing sustainable and regenerative cellulose fibres. However, the latest climate change pressures on the textile industry have uncovered grave environmental issues associated with traditional regenerative cellulose production, such as the viscose manufacturing process. The viscose process requires intensive use of hazardous chemicals which leads to water pollution and ecotoxicity. In addition, if forestry products are unsustainably sourced for this process, this can lead to resource scarcity and deforestation. To provide a holistic solution for mitigating these challenges this study uses the by-products of paper manufacturing dissolved in an ionic liquid to produce regenerated cellulose filaments. Paper mill sludge (PMS) is a cellulosic by-product typically used on animal bedding and land spreading. The material has been dissolved in an ionic liquid - 1-ethyl-3-methylimidazolium diethyl phosphate - with the aid of a co-solvent dimethyl sulfoxide (DMSO) - and spun into continuous filaments for textile production. The mechanical properties of paper sludge filaments are found to be competitive with commercial viscose, which is promising for their drop-in replacement. It is also demonstrated that by increasing the concentration of the PMS from 9% to 12.4%, an improvement of the filament properties can be achieved; an increase in modulus from ∼19 GPa to ∼26 GPa and strength from ∼223 MPa to ∼282 MPa. These values are shown to be competitive with other commercial, less sustainable, regenerated cellulose fibres.

The recycled paper industry produces tons of waste whose disposal is a cost for industry and the environment. This research examines the suitability of de-inked paper sludge (DPS), after pelletization, as a sustainable alternative component to a peat-based growing media, creating ideal root conditions for tree development (e.g. high water storage, low compaction). DPS, tested on Lepidium sativum L. germination, did not show toxicity effects. Three species, Quercus ilex L., Lagerstroemia indica L. and Prunus serrulata “Kanzan”, were planted in 40 cm O pots filled with a control (peat, pumice and zeolite) and the experimental substrate (compost, DPS pellets, pumice and zeolite). After two years in the nursery, the trees were planted in situ. The physical and chemical properties of substrates were analyzed. Plant morphological and physiological parameters were monitored: trunk diameter, leaf dry matter, leaf nitrogen, chlorophyll, and photosynthetic efficiency. The new substrate showed higher Corg (+135%), total N (+73%) and easily available water (+19%), compared to the control substrate used in the nursery. In this new substrate, the trees showed similar radial growth values to the control in the nursery and after transplanting in situ improved their photosynthetic performance in terms of quantum yield of photosystem II (+36%, and +29% in P. serrulata and L. indica, respectively) and electron transport rate (+39%, +25%, and +32% in P. serrulata, Q. ilex and L. indica, respectively). Pelletization represents an attractive amendment for growing media, which enhances the plant’s physiological health status. This study proposes alternative recovery methods for paper industry waste with low environmental impact. As the process is developed locally, it should also contribute to reducing energy-related CO2 emissions from transport. Pelletization represents an attractive novelty in the use of DPS as amendment for growing media, which enhances the plant’s physiological health status. This study proposes alternative recovery methods for paper industry waste with low environmental impact. As the process is developed locally, it should also contribute to reducing energy-related CO2 emissions from transport.

There are many pulp and paper industries all around the globe and in Ethiopia as well different companies are involved in the production and distribution of paper and paper products. Most of the industries especially those in developing countries like Ethiopia produce paper from pulp obtained from wood cellulose. Ethiopia is not producing its pulp and mostly the paper industries depend on imported pulp or recycled paper. There are critical limitations in synthesizing pulp and paper from wood-based cellulose resources mainly the scarcity of wood in some countries and the impact on altering the ecological balance and through frequent deforestation and replantation practice. The present review assesses the potential sources from non-wood resources which can be used as a substitute cellulose raw material for the pulp and paper industry. The study encompasses possible beneficiation routes for manufacturing pulp from non-wood cellulose resources available in Ethiopia for diversified application in the paper industry. With this regard, potential non-wood raw materials for pulping are assed in line with the fulfilment of the target for import substitution strategy, the realization of a safe working environment, and socio-economic betterment of the nation with specific reference to the paper industry.

In recent years, the use of microalgae as feedstock for many marketable products, such as animal/aqua feeds, bioplastics and fertilizers, has gained renewed interest due to their fast growth potential coupled with relatively high lipid, carbohydrate and nutrient content. An algal biorefinery at an industrial site has the potential to sustainably and profitably convert carbon dioxide emissions into microalgal biomass and concomitantly reduce nitrogen and phosphorus from wastewaters. Industrial wastewaters are a potential alternative to traditional media used for large-scale microalgal cultivation. Pulp and paper mills are major consumers of water resources and discharge a huge amount of water to nearby lakes or rivers. This study investigated whether pulp and paper mill waste water is suitable for microalgal cultivation with the aim of achieving significant biomass production. Six different process waters from one Canadian pulp and paper mill were tested with two freshwater green microalgae. All of these waters were unable to support growth of microalgae due to inadequate nutrient concentrations, colour, turbidity and possible toxicity issues. HIGHLIGHTS Two freshwater microalgae strains were screened for potential growth on pulp and paper effluents.; Pulp and paper wastewater effluents were unable to support growth of the microalgae.; Chemical residues from the pulping process, such as peroxide and tannin, may inhibit algal growth.

BACKGROUND Breast cancer remains the most common neoplasm diagnosed among women in China and globally. Health-related questionnaire assessments in research and clinical oncology settings have gained prominence. The National Comprehensive Cancer Network–Functional Assessment of Cancer Therapy–Breast Cancer Symptom Index (NFBSI-16) is a rapid and powerful tool to help evaluate disease- or treatment-related symptoms, both physical and emotional, in patients with breast cancer for clinical and research purposes. Prevalence of individual smartphones provides a potential web-based approach to administrating the questionnaire; however, the reliability of the NFBSI-16 in electronic format has not been assessed. OBJECTIVE This study aimed to assess the reliability of a web-based NFBSI-16 questionnaire in breast cancer patients undergoing systematic treatment with a prospective open-label randomized crossover study design. METHODS We recruited random patients with breast cancer under systematic treatment from the central hospital registry to complete both paper- and web-based versions of the questionnaires. Both versions of the questionnaires were self-assessed. Patients were randomly assigned to group A (paper-based first and web-based second) or group B (web-based first and paper-based second). A total of 354 patients were included in the analysis (group A: n=177, group B: n=177). Descriptive sociodemographic characteristics, reliability and agreement rates for single items, subscales, and total score were analyzed using the Wilcoxon test. The Lin concordance correlation coefficient (CCC) and Spearman and Kendall τ rank correlations were used to assess test-retest reliability. RESULTS Test-retest reliability measured with CCCs was 0.94 for the total NFBSI-16 score. Significant correlations (Spearman ρ) were documented for all 4 subscales—Disease-Related Symptoms Subscale–Physical (ρ=0.93), Disease-Related Symptoms Subscale–Emotional (ρ=0.85), Treatment Side Effects Subscale (ρ=0.95), and Function and Well-Being Subscale (ρ=0.91)—and total NFBSI-16 score (ρ=0.94). Mean differences of the test and retest were all close to zero (≤0.06). The parallel test-retest reliability of subscales with the Wilcoxon test comparing individual items found GP3 (item 5) to be significantly different (P=.02). A majority of the participants in this study (255/354, 72.0%) preferred the web-based over the paper-based version. CONCLUSIONS The web-based version of the NFBSI-16 questionnaire is an excellent tool for monitoring individual breast cancer patients under treatment, with the majority of participants preferring it over the paper-based version.

The AC breakdown properties of Kraft paper, pressboard and the enamel insulation layer in rice oil, peanut oil and corn oil were investigated under both new and aged conditions. The ageing of paper insulators and the enamel insulation layer in oils with the open cup method was carried out at 130 oC for 500 h in an air circulation oven. The puncture breakdown strength was determined by varying the number of layers and thickness of Kraft paper, while various electrode gap distances were used to measure the surface breakdown strength. Experimental results show that the breakdown strength and the tensile strength of paper insulators impregnated with these vegetable oils are comparable to that in mineral oil, and the surface breakdown strength of paper insulators is slightly affected by types of impregnating oils. The ageing significantly reduces both the breakdown strength and the tensile strength of paper insulators in investigated oils. In addition, it was also found that the enamel layer in vegetable oils withstood higher puncture breakdown strength than in mineral oil, and the ageing process significantly reduced the puncture breakdown strength of the enamel layer. This enamel layer was observed to markedly enhance the surface breakdown strength of pressboard.

When conducting a search for research papers, the search should return comprehensive results related to the user’s query. In general, a user inputs a Boolean query that reflects the information need, and the search engine ranks the research papers based on the query. However, it is difficult to anticipate all possible terms that authors of relevant papers might have used. Moreover, general query-based ranking methods emphasize how to rank the relevant documents at the top of the results, but require some means of guaranteeing the comprehensiveness of the results. Therefore, two ranking methods that consider the comprehensiveness of relevant papers are proposed. The first uses a topic-based Boolean query search. This search converts every word in the abstract set and query into a topic via topic analysis by Latent Dirichlet Allocation (LDA) and conducts a search at the topic level. The topic assigned to synonyms of a search term is expected to be the same as that assigned to the search term. Each paper is ranked based on the number of times it is matched with each topic-based Boolean query search executed for various LDA parameter settings. The second is a hybrid method that emphasizes better results from our topic-based ranking result and a general query-based ranking result. This method is based on the observation that the paper sets retrieved by our method and by a general ranking method will be different. Through experiments using the NTCIR-1 and -2 datasets, the effectiveness of our topic-based and hybrid methods are demonstrated.

The effects of furfural generation and partitioning on the aging assessment of oil-paper insulation of power equipment were investigated. Oil-paper samples with various furfural contents were prepared using an accelerated thermal aging experiment. The mass of the furfural generated during the aging of insulation paper was calculated and used to establish the quantitative equation between the accumulated furfural and the degree of polymerization (DP) of the insulation paper. Results showed that the reciprocal of the DP value was linearly related to the amount of furfural generated by the insulation paper. Effects of temperature, moisture, and temperature on the furfural partitioning ratio between oil and paper were analyzed using a furfural partitioning experiment, and a furfural partitioning model was established. Results showed that the furfural partitioning ratio in oil was positively correlated with temperature and moisture but negatively correlated with the DP of the insulation paper. A method for assessing the age of an insulation paper by integrating the furfural generation and partitioning models was proposed and applied on a 500-kV reactor that was returned for factory maintenance. The application result indicated that the method could accurately assess the overall aging condition of the oil-paper insulation of the power equipment.

With the increasing advance of computer and information technologies, numerous research papers have been published online as well as offline, and as new research fields have been continuingly created, users have a lot of trouble in finding and categorizing their interesting research papers. In order to overcome the limitations, this paper proposes a research paper classification system that can cluster research papers into the meaningful class in which papers are very likely to have similar subjects. The proposed system extracts representative keywords from the abstracts of each paper and topics by Latent Dirichlet allocation (LDA) scheme. Then, the K-means clustering algorithm is applied to classify the whole papers into research papers with similar subjects, based on the Term frequency-inverse document frequency (TF-IDF) values of each paper.

There is a lot of investment in research on displaying texture through a stylus pen. However, little is known about the effect of a stylus pen that can provide the texture of pen and paper on user experience. This study investigated whether there is a change in user experience when using a stylus pen that can provide pen-and-paper texture compared with a typical stylus pen. Experiments involving writing and drawing tasks using three tools (a stylus pen that can provide pen-and-paper texture, a typical stylus pen, and analogue pen and paper) were conducted, and user experiences were compared. After a literature review that examined the factors affecting the experience of using a pen, the experiments were conducted to measure usability and emotions. We found little difference between the typical stylus pen and the stylus pen in providing texture in respect of completion time and amount of error. However, the stylus pen that can provide texture showed results closer to those of the analogue pen and paper, and better results than those of the typical stylus pen in respect of familiarity and overall satisfaction of the usability and emotional variables. Therefore, this study confirmed that user experience is improved when using a stylus pen that can provide the texture of pen and paper. Daar is al baie belê en nagevors in die nabootsing van die pen-op-papier gevoel van 'n elektroniese stilus. Daar is egter weinige inligting beskikbaar oor die effek wat tekstuur op gebruikers-ervaring het. Hierdie studie ondersoek of daar n verandering in gebruikerservaring is wanneer n stilus met pen-op-papier terugvoer gebruik word teenoor n tipiese stilus wat nie terugvoer aan die gebruiker lewer nie. Eksperimente wat skryf en teken-take insluit is met drie gereedskapstukke (n stilus met pen-op-papier terugvoer, n tipiese stilus, en n konvensionele pen op papier) uitgevoer. Na n literatuurstudie van stapel gestuur is, is die eksperimente uitgevoer om die bruikbaarheid en subjektiewe terugvoer van die gebruiker te bepaal. Die resultate toon min verskil tussen n tipiese stilus en een met die pen-op-papier gevoel, beide in terme van die tyd om die take te voltooi en die aantal foute begaan. Die stilus met pen-op-papier terugvoer se vertoning was nader aan die van n tradisionele pen, asook beter subjektiewe terugvoer van die gebruiker in terme van vertroudheid en algehele bevrediging. Die gevolgtrekking is dus dat n stilus met pen-op-papier terugvoer gebruikerservaring verbeter.

Microbial fuel cell is a promising technology to harvest energy from wastewater, and effective anode catalysts are essential for its applications. In this study, zero-dimension nitrogen-doped carbon dots, as biocompatible efficient modifiers, were synthesized and decorated onto the carbon paper surface to prepare microbial fuel cell anode. The as-fabricated nitrogen-doped carbon dots decorated carbon paper anode was able to enhance electricity generation and efficient wastewater treatment. It was found that the as-fabricated electrode had a high hydrophilicity, which was favorable for the microbial immobilization. Compared with the carbon paper anode, the biofilm on the as-prepared anode was almost twice of thickness. After introducing nitrogen-doped carbon dots, the extracellular electron transfer process from the microorganisms to the anode was enhanced. The microbial fuel cell with the as-developed anode generated a remarkable power output of 0.32 mW, 1.1 times higher than that of the raw carbon paper anode with same measurement area. Moreover, 16 sRNA pyrosequencing analysis shows that the quantity of Pseudomonas on the electrode increased by ∼40%, which also promoted the electron transfer rate by excreting mediators like phenazines or phenazine derivatives. This work developed a new approach to design microbial fuel cell anode material and fabricate a high-efficiency and environmentally friendly anode for electricity generation from wastewater.

The world paper industry produces a great amount of industrial solid waste that undergoes a treatment process that can be either primary, secondary, or tertiary, in order to adapt the waste for correct disposal. The paper manufacturing industries search for the best way to dispose of their wastes, generally in landfills, but there are few studies proving the effectiveness of such measure from the environmental, technological and economic points of view. Knowing the characteristics of this waste and understanding the treatment process it is submitted to are fundamental issues to manage it and comply with environmental demands. The purpose of this paper is to perform a chemical, mineralogical, thermal, morphological, physical and environmental characterization of the paper and pulp industry wastes, in order to assess alternatives for their adequate disposal, such as controlled landfills, sanitation, incineration, and sea dumping. It was observed that the material presents physical, chemical, and morphological features that indicate the possibility of reusing it in other production chains, such as the ceramic industry, besides being classified as non-hazardous wastes. Furthermore, disposal in sanitary landfills presents advantages in environmental and technological terms.

Indigenous plants are widely abundant in Mauritius and if made proper use of, these renewable plants can contribute largely to the local economic sector. This paper assesses the suitability of producing eco-friendly and biodegradable papers using low-cost raw materials by means of fibre from Pandanus utilis’ leaves commonly known as ‘Vacoas’. The leaves were used along with Arundo donax or wastepaper to manufacture composite paper samples in the ratios of 20:80, 40:60, 60:40, 80:20 and 100:0. Chemical pulping was done through Kraft process for a period of 1.5 h at a concentration of 14 wt% NaOH and 4 wt% Na2S at 90 ± 2.5 °C. The mean thickness of the papers was determined to be 0.261 ± 0.027 mm. It was found that the 100% Vacoas fibres had the highest absorbency rate of 1.8 ± 0.5 s followed by the composite A. donax and Vacoas fibre (1.8 ± 0.3 s). The most abrasion resistant paper which also demonstrated the highest burst index of 0.63 kPa m2 g− 1 and tensile index 11.8 N m g− 1 was observed to be that of 100:0 Vacoas fibre paper requiring 35 turns to get abraded followed by the P. utilis and A. donax mix where the 80:20 fibre ratio revealed a high bursting index of 0.45 kPa m2 g− 1 requiring 25 turns to get abraded while 40% P. utilis and 60% A. donax had a high tensile strength of 11.9 N m g− 1. Vacoas to wastepaper mix ratios of 20:80 and 40:60 were found to have the highest mean recovery angles of 61.3 and 59.6°, respectively.

This study estimates efficiency in energy utilization at firm level and feasible energy saving target of the pulp and paper industry in India. For this analysis, data is extracted from prowess database for a panel of 67 major pulp and paper producing firms over the period of 2003–04 to 2013–14. We employed radial and non-radial variants of data envelopment analysis to assess the feasible energy saving target with the current level of output. Particularly, we employed slack-based method with variable returns to scale as a flexible and pragmatic approach to performance analysis. Results reveal no significant improvement in the energy efficiency level of the firms over the study period and show vast energy saving potential. Results of slack-based measure of energy efficiency show the feasible energy saving potential of 40%. Further, size of the firm, age and financial performance are important factors that influence energy efficiency. Therefore, this study recommends special attention to the paper industry while implementing energy efficiency programme. We also reviewed four major policies for industrial energy efficiency improvement initiated by Bureau of Energy Efficiency, India.

In heterogeneous networks where macro cells and metro cells use the same frequency band to communicate with their respective users, the major problem limiting performance is the interference caused by macro cells to metro cells. The information theoretic result known as dirty paper coding provides a way to address this problem and significantly improve the performance of heterogeneous networks with co-channel deployment. In this paper, we show how a simple dirty paper coding scheme employing Tomlinson-Harashima pre-coding with partial interference pre-subtraction can be employed by metro cells to mitigate the interference caused by macro cells. A performance study included in this paper shows that the proposed dirty paper coding scheme can lead to significant improvement in user rate statistics.

A 3D modeling system with all-inclusive functionality is too demanding for a casual 3D modeler to learn. There has been a shift towards more approachable systems, with easy-to-learn, intuitive interfaces. However, most modeling systems still employ mouse and keyboard interfaces, despite the ubiquity of tablet devices and the benefits of multi-touch interfaces. We introduce an alternative 3D modeling and fabrication paradigm using developable surfaces, inspired by traditional papercrafting, and we implement it as a complete system designed for a multi-touch tablet, allowing a user to fabricate 3D scenes. We demonstrate the modeling and fabrication process of assembling complex 3D scenes from a collection of simpler models, in turn shaped through operations applied to virtual paper. Our fabrication method facilitates the assembly of the scene with real paper by automatically converting scenes into a series of cutouts with appropriately added fiducial markers and supporting structures. Our system assists users in creating occluded supporting structures to help maintain the spatial and rigid properties of a scene without compromising its aesthetic qualities. We demonstrate several 3D scenes modeled and fabricated in our system, and evaluate the faithfulness of our fabrications relative to their virtual counterparts and 3D-printed fabrications.

Black liquor, an industrial waste, also generally called spent liquor is a promising feedstock for production of bio-carbon due to its high lignin and energy contents. Mild processing conditions and sustainable resource utilization can drive commercial utilization of this industrial waste. A novel oxidative procedure using hydrogen peroxide as a green liquid oxidant at room temperature for processing of paper recycling neutral sulphite semi-chemical spent liquor was established and evaluations were carried out for its efficiency. Standard hydrothermal carbonization was carried out for comparing bio-carbon production qualitatively and quantitatively using the same spent liquor. The oxidation procedure was performed at room temperature using 5% of H2O2 followed by washing in diluted sulfuric acid (0.15 N) while hydrothermal carbonization was performed at 250 °C. The bio-carbon produced were similar in terms of ash percentage and ranged from 1.25 ± 0.05 to 1.48 ± 0.05% for oxidation method and from 1.11 ± 0.03 to 1.45 ± 0.04% for hydrothermal carbonization. The carbon contents for the oxidation method ranged from 60.54 to 61.50% and 66.81–67.31% for hydrothermal carbonization while higher heating values ranged from 25.32 to 26.11 MJ/kg and from 28.68 to 29.34 MJ/kg respectively. The mass yield ranged from 29.98 to 31.88% by the oxidation, while it was 15.02–16.08% by hydrothermal carbonization.

The global demand for bio-plastic particularly polyhydroxyalkanoate (PHA) have been increased in the last few decades as a substitute of petrochemical-based plastic. Utilization of waste paper, the primary constituent of municipal solid waste (MSW), as a carbon source for polyhydroxybutyrate (PHB) production is not only an alternative, environmental friendly route of waste management but also helps to valorize the waste. In this study, hydrogen peroxide pretreated waste paper saccharification has been optimized using central composite design (CCD). The maximum hydrolysis (88.18%) occurred at paper loading 5.0 g/L, agitation 242 rpm, working volume 20%, cellulase 49.82 U/g, β-glucosidase 20.9 U/g and hemicellulase 29.5 U/g. PHB synthesis and biomass accumulation by xylose-utilizing Burkholderia sacchari using waste paper hydrolysate were studied using different nitrogen sources and carbon to nitrogen (C/N) ratios. Maximum PHB and dry cell weight (DCW) occurred with ammonium sulfate and a C/N ratio of 20. The highest biomass (3.63 g/L), the maximum PHB accumulation (44.2%) and the maximum reducing sugar utilization (92.1%) were observed after 48 h of cultivation using diluted hydrolysate. The physicochemical properties of the extracted PHB were compatible with the standard PHB. Hence, the waste paper could be exploited as a renewable feedstock for the sustainable production of PHB.

It is necessary to preserve rumen fluid for transport from slaughterhouses to the pretreatment facilities for use in treating lignocellulosic biomass. In this study, we investigated how the preservation of rumen fluid at various temperatures affects its use in hydrolysis of waste paper. Rumen fluid was preserved anaerobically at 4, 20, and 35 °C for 7 days. The number of protozoa and fibrolytic enzyme activity after preservation at 4 °C were significantly higher than that after preservation at either 20 or 35 °C. Waste paper was subsequently treated with preserved rumen fluid at 37 °C for 48 h. Preservation at 20 °C remarkedly decreased the hydrolysis of waste paper. Xylanase activity in rumen fluid preserved at 35 °C increased during the treatment, which enhanced the solubilization of waste paper as comparable to the control and preservation at 4 °C. Pretreatment of waste paper with rumen fluid preserved at 4 °C showed that the fluid retained high fibrolytic activity, and reduced the loss of organic carbon as substrate for methanogens. Our results suggest that preservation of rumen fluid at 4 °C is most suitable for efficient pretreatment and methane fermentation of waste paper.

This work demonstrates a novel-type paper-based solid electrolyte (PBSE) and its application in Al-air battery, which is targeted for miniwatt applications. Benefited from the solid-form electrolyte, a liquid-free operation of the Al-air battery is realized, eliminating the potential leakage hazard and therefore improving the battery practicability. The PBSE is prepared by impregnating gel electrolyte into porous cellulose paper, followed by a solution casting process to solidify the gel. The as-prepared PBSE can either be used in mechanical rechargeable Al-air batteries, or be integrated into single-use flexible Al-air batteries. Currently the PBSE can achieve a moderate battery performance with a peak power density of 3.8 mW cm-2 and an Al specific capacity of 900.8 mA h g-1. Properties of the PBSE can be further improved by a comprehensive parametric study on its fabrication parameters, such as gel concentration, casting temperature, casting time, porosity and pore size of paper substrate, etc.

The paper presents the results of research and analysis of literature data on the paper insulation's thermal aging. An exponential decrease in the degree of polymerization of paper insulation from the aging time is established, at the starting time of transformers’ operation the aging rate of paper insulation is maximal and after that its slowing down. It was found out that the degree of polymerization at the starting time of the transformer's operation can be in the range of 900 units, this is due to its drying during the manufacturing process.

Small companies encounter difficulties to adapt to new markets with a sustainable perspective. The subject of this article is a paper transformation company which has been eager to develop the organic farming market by developing a new plant support. Alternatives made from plant fibres or plastics exist, such as jute and polypropylene. The main difficulty of this project was to ecodesign a paper product with a multicriteria approach. The factors considered have been divided into two categories. Firstly, the environmental impacts calculated according to the Life Cycle Assessment methodology (on raw material extraction, manufacturing and end-of-life) are summarised. Secondly, the characteristics of the product are discussed in regards to these results and sustainability questions as part of the interpretation phase. Finally, ways of improvement of the LCA methodology to improve the study in terms of geographical representativeness and societal considerations are discussed.

Researchers from academia and the corporate-sector rely on scholarly digital libraries to access articles. Attackers take advantage of innocent users who consider the articles' files safe and thus open PDF-files with little concern. In addition, researchers consider scholarly libraries a reliable, trusted, and untainted corpus of papers. For these reasons, scholarly digital libraries are an attractive-target and inadvertently support the proliferation of cyber-attacks launched via malicious PDF-files. In this study, we present related vulnerabilities and malware distribution approaches that exploit the vulnerabilities of scholarly digital libraries. We evaluated over two-million scholarly papers in the CiteSeerX library and found the library to be contaminated with a surprisingly large number (0.3-2%) of malicious PDF documents (over 55% were crawled from the IPs of US-universities). We developed a two layered detection framework aimed at enhancing the detection of malicious PDF documents, Sec-Lib, which offers a security solution for large digital libraries. Sec-Lib includes a deterministic layer for detecting known malware, and a machine learning based layer for detecting unknown malware. Our evaluation showed that scholarly digital libraries can detect 96.9% of malware with Sec-Lib, while minimizing the number of PDF-files requiring labeling, and thus reducing the manual inspection efforts of security-experts by 98%.

Aiming at the problem of easy tampering and difficult integrity authentication of paper text documents, this paper proposes a robust content authentication method for printed documents based on text watermarking scheme resisting print-and-scan attack. Firstly, an authentication watermark signal sequence related to content of text document is generated based on the Logistic chaotic map model; then, the authentication watermark signal sequence is embedded into printed paper document by using a robust text watermarking scheme; finally, the watermark information is extracted from scanned image of paper document, and compared with the authentication watermark information calculated in real time by the text document content obtained by OCR technology, thereby performing content integrity authentication of the paper text documents. Experimental results show that our method can achieve the robust content integrity authentication of paper text documents, and can also accurately locate the tampering position. In addition, the document after embedding the watermark information has a good visual effect, and the text watermarking scheme has a large information capacity.

Oil-immersed insulation paper (OIP) bushing is one of the most important equipment in power transmission and distribution systems. Moisture is one of the most serious factors that affect the insulation status of OIP bushing. In this paper, the OIP bushing was assumed to be in a stable and simplicity condition, and then the transient moisture distribution of capacitor core and its effects on the electric field were studied. First, by dissecting a 110 kV OIP bushing, the specific sizes for modelling were obtained. Afterwards, a moisture diffusion model for OIP bushing was established based on COMSOL Multiphysics software, and it was also verified by moisture diffusion experiment. Then, the moisture distribution for different conditions were obtained and analyzed. Finally, a model for the electric field of OIP bushing was established, and then the effects of moisture on the electric field were studied.

The aging of the transformer oil-paper insulation distributes spatially, which results in changes in paper resistivity in different regions. This paper establishes an iterative inversion algorithm using the finite element method to calculate the oil-immersed paper resistivity in different regions of a transformer. This algorithm sets the transformer dielectric loss factor tan δ at low frequency, the dielectric parameters of the transformer oil as inputs and the oil-immersed paper resistivity as output. The resistivity obtained from inversion can be used as a reference to access the insulation state of the oil-paper insulation. This paper aims at achieving the nondestructive detection of the partial state of the oil-paper insulation.

Transformer insulation paper is a key indicator for transformer remaining operational life. Paper decomposition is evaluated using the degree of polymerization (DP) which calls for samples of insulation paper from operating transformers. Since collecting such paper samples is extremely difficult, other indicators have been used to indirectly reveal the DP value of insulation paper. This includes dissolved gases in transformer oil such as carbon oxides and hydrocarbon gases, furan compounds, methanol, ethanol, and moisture along with some oil characteristics such as interfacial tension. However, for the same oil sample, these individual parameters lead to different DP values. This is attributed to the lack of accuracy of the established mathematical and artificial intelligence models correlating DP with each of the above mentioned individual parameters. This paper presents a self-learning method to estimate the DP value of transformer insulation paper based on multiple transformer oil aging parameters. The proposed method comprises data processing, fuzzy c-means and linear regression. Results reveal that estimating the DP value based on multiple aging parameters is more accurate than estimating it using one single parameter as per the current practice. The proposed method not only helps to understand the correlation between multiple oil aging parameters and the DP value of paper insulation, but also promotes the establishment of more accurate life assessment models for power transformers based on these oil aging parameters.

This paper shows how chemical sludge (CS) generated during wastewater treatment at a paperboard mill can be quickly dried at low-temperature and employed in bark-fired boilers to reduce slagging and corrosion problems. By using a cyclone-dryer operated at an inlet-air velocity of 110 m/s and a temperature of 90 °C, the dry-matter content of CS was increased from approximately 19 to 82%. The residence time of CS inside the cyclone was approximately 2 s when using the inlet-air velocity mentioned above. Disaggregation of the feedstock caused by collisions with the cyclone wall and between particles played a crucial role in enhancing the efficiency of heat and mass transfer. Three co-pelletized mixtures of Scots pine bark (SPB) and dried-CS were combusted in a 40 kW fixed-bed burner. Flue gas analysis was performed with a gas analyser. Coarse and fine ash were analysed by SEM-EDS and XRD. NOx and SO2 emissions increased with increasing amount of CS in the mixtures. Mono-combustion of SPB resulted in a large quantity of slag (i.e., molten ash) with a high degree of sintering (i.e., hardness of the slag), and ash deposits formed on heat transfer surfaces were rich in K2SO4 and KCl. Mixtures of SPB and CS were less prone to slagging, and the amount of alkali chloride in the deposits was reduced in favour of alkali sulphate formation.

Having been generated with a tremendous amount annually, paper waste (PW) represents a large proportion in municipal solid waste (MSW) and also a potential source of renewable energy production through the application of anaerobic digestion (AD). However, the recalcitrant lignocellulosic structure poses obstacles to efficient utilization in this way. Recently, anaerobic and microaerobic pretreatment have attracted attention as approaches to overcome the obstacles of biogas production. This study was set out to present a systematic comparison and assessment of anaerobic and microaerobic pretreatment of PW with different oxygen loadings by five microbial agents: composting inoculum (CI), straw-decomposing inoculum (SI), cow manure (CM), sheep manure (SM), and digestate effluent (DE). The hints of microbial community evolution during the pretreatment and AD were tracked by 16S rRNA high-throughput sequencing. The results demonstrated that PW pretreated by DE with an oxygen loading of 15 ml/gVS showed the highest cumulative methane yield (CMY) of 343.2 ml/gVS, with a BD of 79.3%. In addition to DE, SI and SM were also regarded as outstanding microbial agents for pretreatment because of the acceleration of methane production at the early stage of AD. The microbial community analysis showed that Clostridium sensu stricto 1 and Clostridium sensu stricto 10 possessed high relative abundance after anaerobic pretreatment by SI, while Bacteroides and Macellibacteroides were enriched after microaerobic pretreatment by SM, which were all contributable to the cellulose degradation. Besides, aerobic Bacillus in SI and Acinetobacter in SM and DE probably promoted lignin degradation only under microaerobic conditions. During AD, VadinBC27, Ruminococcaceae Incertae Sedis, Clostridium sensu stricto 1, Fastidiosipila, and Caldicoprobacter were the crucial bacteria that facilitated the biodegradation of PW. By comparing the groups with same microbial agent, it could be found that changing the oxygen loading might result in the alternation between hydrogenotrophic and acetoclastic methanogens, which possibly affected the methanogenesis stage. This study not only devised a promising tactic for making full use of PW but also provided a greater understanding of the evolution of microbial community in the pretreatment and AD processes, targeting the efficient utilization of lignocellulosic biomass in full-scale applications.

Most of today's graph analytics systems model static graphs and do not support business use cases that require the ability to: (i) query the dynamic graph data for a time-evolving system, (ii) carry out investigations on its historical evolution, and (iii) audit past business decisions made with potentially stale or incorrect data. This position paper presents our vision for bi-temporal dynamic graph analytics, and sketches a design for a system that efficiently supports these requirements.