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Mitigation of global warming, energy security and industrial competitiveness urge the energy-intensive pulp and paper industry (PPI) to transform energy use practices. This study investigates how the PPI has responded to the need for the energy transition in the 2000s. Finland and Sweden as forerunners of energy-efficient operation and decarbonization of the PPI are used as target countries. Understanding of changes in energy consumption is complemented using decomposition analysis (Logarithmic Mean Divisia Index Method) and the energy efficiency index approach. Analysis of companies’ investments in energy technologies is used for explaining changes in energy production. Evidence of significant development towards the more sustainable operation of the PPI was found. Energy consumption per produced unit has decreased, i.e., energy efficiency has improved. Fossil fuels have been partially replaced with bio-based alternatives. Thus, the CO2 intensity has decreased substantially. The generation of renewable electricity has increased in both countries. Examples of Finland and Sweden indicate that the PPI has great potential to contribute to CO2 emission reduction worldwide in the future as energy efficiency can be further improved, and the share of fossil fuels can be decreased increasing the use of biofuels and self-generated green electricity at least in kraft pulp mills.

With the increased awareness of reusing solid wastes for higher sustainability and the concern of water pollution associated with phosphorus over-emission, there are strong interests in developing solid waste based adsorbents for purifying phosphorus-containing wastewater. As a rich calcium resource, paper mill sludge (i.e., a major solid waste from pulping industry) can be used as phosphorus removal adsorbent after calcination. Thus, in this work, a simple and clean thermally treating route has been proposed for preparing calcium-containing biochar from paper mill sludge. The effect of the physicochemical properties of paper mill sludge and its carbonization condition on phosphorus adsorption has been analyzed. Moreover, the influence of some key adsorption parameters, e.g., biochar dosage, initial pH of solution, co-existing anions, initial phosphorus concentration and contact time has also been investigated. The results showed that the phosphorus adsorption data could be fitted well with pseudo-second-order kinetic and Langmuir isothermal models. The calculated maximum adsorption capacity of the as-prepared optimal calcium-containing biochar could reach to 68.49 mg·g−1 at 25 °C. Combined with the characterization results, it can be reasonably inferred that the adsorption process was chemisorption-dominated. Lastly, the application of this spent adsorbent in agriculture field has also been discussed. In brief, this work provided a feasible strategy for converting paper mill solid waste to an environmental functional material (i.e., calcium-rich biochar) for remediation of eutrophic water.

This study optimizes a novel surfactant-assisted green liquor dregs (GLD) pretreatment of paper mill sludge (PMS), both of which are wastes from the kraft pulping industry, using a combined Response Surface Methodology (RSM) design. Optimized conditions give a maximal reducing sugar release of 16.38 g/L. A substantial reduction in heavy metals aluminum, chromium, cobalt, arsenic, lead, and copper after pretreatment illustrates the enhancement of substrate digestibility by reducing toxic elements. Separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) for hydrogen production are assessed. SSF produced a hydrogen yield of 3.72 mL/g, displaying a 36.26% increase from pretreated PMS compared to SHF. These findings provide insights into possible methods of reducing process duration, energy input, and costs incurred with waste disposal within the paper industry. Furthermore, improved hydrogen yield using an SSF process demonstrates the potential beneficiation of pulp and paper GLD and PMS wastes.

Writing and presenting results is important for any research work. Publishing is not enough; it should be written clearly and consistently for others to read and cite. We present a review of different techniques, for improving the writing in research papers intended for publishing. These include how to write the title, whether to use active or passive voice, how long sentences should be, how to present the uncertainty, understanding the International System of Units (SI) writing conventions, how to assign authorship, how to effectively use references, how to present the work, and how to publish it in a journal. This paper is a summary of the main and most recent recommendations in the scientific field on how to write a research paper to increase its impact.

Supercapacitors are favored by researchers because of their high power density, especially with the acceleration of people's life rhythm. However, their energy density, especially from the point of view of the whole energy storage device, is far lower than that of commercial batteries. In this work, a kind of customizable full paper-based supercapacitor device with excellent self-healing ability is fabricated by simple and low-cost screen printing, electropolymerization and dip coating methods. The resultant separator-free supercapacitor device exhibits both ultrahigh gravimetric and areal specific energy (power) densities of 39 Wh kg−1 (69 kW kg−1) and 692 μWh cm−2 (236 mW cm−2), achieving excellent supercapacitor performance. Notably, the addition of vitrimers endows the whole device with outstanding self-healing properties, which is helpful for enhancing the adaptability of the device to the environment. In addition, this kind of paper-based device also displays good photothermal and electromagnetic shielding performances. These striking features make paper matrix composites attractive in the fields of supercapacitors, medical photothermal treatment and electromagnetic shielding.

Photonic crystals film that possesses periodic dielectric structure have shown great prospect in developing environmentally friendly paper alternatives due to the unique properties of dye free and non-photobleaching, but their practical application is limited by the weak interaction between colloidal particles. Although some progress has been obtained, it is still a challenge to develop photonic paper with the desired mechanical and optical properties. Herein, multifunctional hard core/soft shell nanoparticles with controlled size are fabricated by semi-continuous seed emulsion polymerization method. Compared with convention colloidal particles, these core/shell nanoparticles can facile self-assemble into large-scale dense ordered structure film via dried at room temperature due to the relatively low glass transition temperature (Tg) of the shell layers. The facile fabrication route enables the continuous high-through put production of the photonic papers. The as-formed papers not only possess the capacity to solvent (water/ethanol) rewritable and multicolor painting, but also can rapidly reversible mechanochromic. Moreover, due to the good compatibility of core/shell interface, these photonic films possess excellent mechanical properties, demonstrating that this multifunctional film makes the fabrication of novel robust rewritable papers possible and enables visual monitoring of deformation degree.

In recent times, it has been witnessed that wireless systems based on IoT-based have developed rapidly in various sectors. The IoT (Internet of Things) is the network in which physical devices, equipment, sensors and other objects can communicate among themselves without human involvement. The WSN (Wireless Sensor Network) is a central component of the IoT, which has proliferated into several different applications in real-time. The IoT and WSNs now have various critical and non-critical applications impacting nearly every area of our everyday life. WSN nodes are usually small and battery-driven machines. Thus, the energy effective data aggregation techniques that increase the lifespan of the network are highly significant. Various approaches and algorithms for energy-efficient data aggregation in IoT-WSN systems were presented. This paper reviews the literature with specific attention to aspects of wireless networking for the preservation of energy and aggregation of data.

Activating flux is made up of inorganic material mixed with a volatile medium. The objective of this study is to identify and review the literature in activating flux, and different type of welding techniques. For that purpose, a structured review method is adopted and the Scopus database is used as a primary source for the selection of papers. The papers were identified using the string term of “Activating flux” OR “Activated flux” in the title of papers. And a total of 238 papers were identified for the study. Besides the above few other papers were also reviewed and the materials used, the type of flux used, and the findings of different combinations were highlighted in the form of tables. The findings of the study provide a comprehensive understanding of the different type of welding techniques focusing on TIG welding, and the different combination of flux used and their impact was summarized.

The aim of the study was to use black liquor produced during the soda pulping process in a pulp and paper mill to increase methane production during pulp and paper industry sludge treatment and decrease the treatment cost. The effects of black liquor on sludge solubilization and methane production were assessed and the economic feasibility of the process was evaluated. Black liquor and NaOH were found to be equivalent in the thermochemical pretreatment process to solubilize sludge and disintegrate flocs. However, adding black liquor increased the background chemical oxygen demand and volatile fatty acid concentration and increased the amount of methane produced by approximately 7-30%. A start-up delay was emphasized by first-order kinetics model due to black liquor addition while methane production remained stable. Economic assessments of five scenarios were performed. It was found to be economically feasible to use black liquor to replace NaOH for the thermal pretreatment process. The surplus methane generated suggested that co-digestion of sludge and black liquor allows surplus bioenergy to be produced during the thermochemical pretreatment anaerobic digestion process.

The use of online learning and subsequent online testing has expanded rapidly in pharmacy programs across the United States. Numerous published studies have compared online learning with traditional methods in pharmacy. However, no such studies have been published in pharmacy. This study's objective is to compare first-professional year student preferences for computer-based vs. traditional paper-and-pencil testing for a required social and administrative pharmacy class.All students enrolled in the class were invited to complete one brief survey at the end of the semester to determine their testing preference.Of the 138 first-professional year students completing the survey, 79% (109 of 138) preferred computer-based testing, 9% had no preference, 6% (8 of 138) preferred paper-and-pencil testing, and the remainder (8 of 138) stated it depended on what was being tested. Ninety-one percent of students did not perceive the testing method to impact their grades. Students preferred computer-based testing over traditional paper-and-pencil as a convenient testing method (mean 4.73 vs. 3.4, P.001), providing immediate feedback (mean 4.87 vs. 1.91, P.001), and as a more effective testing method (mean 4.57 vs. 3.96, P.001).First-professional year students preferred computer-based over traditional paper-and-pencil testing for a social and administrative science class, with the method of testing not perceived to impact grade. This finding is timely, given the recent required transitioning of all pharmacy classes and subsequent testing to an online format due to the coronavirus disease of 2019 pandemic.

Thermal papers are replacing the conventional form of printing and are being extensively used across the globe. This study encompasses a non-destructive approach to examine thermal papers by using ATR-FTIR spectroscopy and Video Spectral Comparator (VSC), where the former technique helps in characterizing and discriminating different samples and the latter helps in deciphering the faded prints on thermal paper. The qualitative analysis of the spectroscopic data based on peak to peak comparison and quantitative analysis using chemometrics has been done to obtain high discriminating power. Multivariate analysis using HCA gave a discriminating power of 83.82% and PCA showed a variance of 95.64%. The strength of the study is portrayed through the decipherment of artificially and naturally faded thermal papers using VSC and analyzing the effect of different storing conditions on their rate of fading.

Flexible paper-based surface enhanced Raman spectroscopy (SERS) substrate has attracted great attention in the sensitive detection of analytes in recent years. However, due to its inherent hydrophilic surface, the nanoparticles will not be concentrated very well on the surface of the paper. This reduces the reproducibility and sensitivity of the paper-based substrate. Herein, we demonstrate flexible hydrophobic paper-based substrate using silver nanocubes loaded on polymethylhydrosiloxane modified filter paper (AgNCs@SiO2/PMHS modified filter paper) to realize high sensitivity and reproducibility. The hydrophobic filter paper was obtained by dip-soaking the filter paper into PMHS solution, resulting in increased contact angle to ~112.5°. The AgNCs@SiO2/PMHS modified paper substrate shows high analytical enhancement factor (AEF) of 6.55 × 106, which is 2.2-fold enhancement compared to AgNCs@SiO2/normal paper substrate, and a low detection limit of 0.1 nM rhodamine 6G and 0.89 nM adenine. The high SERS enhancement factor and sensitivity is attributed to the high hotspots density created in the hydrophobic surface as a result of the excellent uniformity and superior sample collection efficiency compared to the normal filter paper-based substrate. Besides, the substrate shows excellent spot-to-spot and substrate-to-substrate reproducibility, with relative standard deviation (RSD) of 6.05% and 9.22%, respectively. Moreover, the AgNCs@SiO2/PMHS modified filter paper substrate achieved good stability; the Raman signal intensity only drops by 25.88% after 3 months of exposure to air. Therefore, this flexible hydrophobic AgNCs@SiO2/PMHS modified filter paper substrate with low cost fabrication and label-free SERS detection is a promising SERS platform for analytical and biological sensing applications.

Graphene-based papers have recently triggered considerable interests in developing the application as thermal interface materials (TIMs) for addressing the interfacial heat transfer issue, but their low through-plane thermal conductivity (κ⊥), resulting from the layer-by-layer stacked architecture, limits the direct use as TIMs. Although various hybrid graphene papers prepared by combining the graphene sheets and the thermally conductive insertions have been proposed to solve this problem, achieving a satisfactory κ⊥ higher than that of commercial TIMs (>5 W m−1 K−1) remains challenging. Here, a strategy aimed at the construction of heat pathways along the through-plane direction inside the graphene paper for achieving a high κ⊥ was demonstrated through the simultaneous filtration of graphene sheets with two different lateral sizes. The as-prepared graphene paper presented a hierarchical structure composed of loosely stacked horizontal layers formed by large graphene sheets, intercalated by a random arrangement of small graphene sheets. Due to the heat pathways formed by small graphene sheets along the through-plane direction, the hierarchically structured graphene paper exhibited an improved κ⊥ as high as 12.6 W m−1 K−1 after a common graphitization post-treatment. In the practical test, our proposed paper as an all-graphene TIM achieved an enhancement in cooling efficiency of ≈ 2.2 times compared to that of the state-of-the-art TIM, demonstrating its superior performance to meet the ever-increasing heat dissipation requirement.

Membrane heat exchangers were used for moisture and heat recovery from a hot and humid natural gas stream in indirect contact with an air stream. A plate membrane module with spiral channels on each side was designed to configure gas and air streams in co-current and counter-current flow. Two types of membranes, a commercial kraft paper, and a laboratory-made thin-film composite membrane, were used as the module core. The thermal efficiency and the water recovery from the humid gas were calculated and compared under different operating conditions. At a unit flow ratio of air/gas, the greatest effectiveness was achieved at a methane flow of 100 cm3/min, but water recovery increased at higher gas flows. For the counterflow configuration, an air/methane flow ratio of 2 was sufficient to achieve the highest total effectiveness and water recovery; however, larger air/gas ratios were beneficial to improve heat and moisture transfer for the co-current configuration. The highest water recovery by the kraft paper and composite membrane was achieved (approximately 15 mgH2O/cm2.h) for the input gas with the highest humidity. The dehumidification performance of kraft paper as a porous and hydrophilic membrane was slightly better than that of the composite membrane containing a dense hydrophilic polymer thin film in most cases. A relatively low heat transfer coefficient was found for the module, which was increased by using higher gas flow rates at higher humidity conditions.

Paper electronics have been fast developed in recent years due to their degradability and recyclability; however, most of them are barely equipped with logic functions, impeding them from becoming autonomous on-paper systems. To provide a working unit for logic implementations, a paper field-effect transistor (FET) with a clay-graphite channel that demonstrated negative differential resistance (NDR) is fabricated in this study. The device exhibited a p-type semiconductor characteristic with an optical bandgap of ∼1.97 eV according to photoluminescence analysis, resulting from considerable defective graphite mixed with clay in the channel. Considering that the NDR behavior is theoretically predicted to be tunable by the contact resistance, we fabricated FETs with different contact resistances and observed that the NDR behavior occurred in devices with relatively lower contact resistance. The NDR effect is also tunable by varying the gate voltage, which matches well with simulation results. The possible mechanism for the NDR behavior is the decrease in carrier drift velocity induced by band-to-band tunneling, associated with impurities-induced trapping states and gate-induced confined states. This work provides a promising and easy pathway to develop digital components using paper electronics in the near future.

Paper mill sludge biochar (PMSB) was produced via pyrolysis in a muffle furnace at 750 °C. Subsequently, PMSB was soaked in the HCl solution and washed by deionized water to obtain minerals and organic materials. The organics were named as demineralized paper mill sludge biochar (DPMSB). It was found that PMSB and minerals had larger pore diameters than DPMSB. Also, the removal efficiencies of Cu, Zn and As were above 95.00% by using PMSB and minerals because of the large pores, abundant carbonates and OH groups, while the removal efficiencies of Cu, Zn and As by using DPMSB were 40.92%, 87.93% and 94.99%, respectively, owing to the H + competition to Cu and Zn adsorption but more micropores to enhance As adsorption. The adsorption behavior of PMSB showed that the adsorption isotherms of Cu, Zn and As could be well simulated by the Freundlich model, and the pseudo-second-order model fitted the adsorption kinetics of Zn and As, and the Elovich model fitted the adsorption kinetics of Cu. Moreover, the optimal dosages of PMSB to adsorb Cu, Zn and As were 0.3, 0.3 and 0.1 g/L, respectively. And the pH values of the solution for the efficient adsorption of Cu, Zn and As were 4.00, 6.00 and 2.00, respectively. This work provided basic data for the potential commercial application of PMSB for heavy metals removal from wastewater.

The design of a cheap, simple, and handy sensing system for rapid quantitation of pharmaceuticals becomes mandatory to ease drug development procedures, quality control, health care, etc. This work describes a simple, innovative, and easily manufactured paper-based device using a correction pen as a plotter for hydrophobic/lipophobic barriers and graphene quantum dots for recognition and quantification of the hemostatic drug carbazochrome, via fluorescence turn-off mechanism mediated by the inner filter effect. A smartphone-based all-in-one device fitted with an inexpensive 365 nm flashlight as a UV light source and a free image processing software was developed for rapid and reliable interpretation of the fluorescence change from the paper-based device upon introduction of the drug. The simple and convenient steps permit the analysis of many samples in a very short time. The smartphone-based all-in-one device featured excellent sensitivity for carbazochrome with a limit of detection equals to 12 ng/detection zone and good %recovery (100.0 ± 0.4). The reliability of the device was ascertained by favorable statistical comparison with the analogous optimized conventional fluorimetry method and a reference HPLC method. The device has been successfully applied for versatile quantitation of carbazochrome in tablets and on manufacturing equipment surfaces with excellent recoveries. The device offers many green aspects that definitely assist the implementation of the sustainability concept to analytical laboratories. The cost-efficiency, reliability, and ease of fabrication as well as the greenness and user friendship qualify the device for wide application in low-income communities.

CdSe/ZnS quantum dots (QDs) and 3,3,5,5-tetramethylbenzidine (TMB) were incorporated into a filter paper to produce a paper-based colorimetric device for Hg2+ detection. Under visible light, the CdSe/ZnS QDs acted as a photocatalyst to oxidize TMB, resulting in blue colorization on the paper. Moreover, Hg2+ could enhance the photocatalytic activity of CdSe/ZnS QDs and consequently caused an increase in the color intensity of the paper. The color change of the paper-based device can be directly identified by naked-eye observation or captured by a smartphone and analyzed using image processing software for quantitative analysis. Under optimal conditions, a low detection limit of 0.09 µM was achieved. This device was applied for real samples, including tap water and cosmetics, and achieved satisfying results.

As a kind of industrial hazardous solid waste, paper mill sludge (PMS) was hard to treated by conventional process because of its high moisture, high organic content and and high environmental risk. The hydrothermal liquefaction (HTL) shows excellent potential for the conversion to a wide variety of organic matter with high water contents including various kinds sludge into fuels or value-added chemicals. In this paper, the liquefaction potential for PMS under different reaction temperatures were investigated, and the products were classified into several main components based on the results of GC-MS. The results showed that the highest yield of bio-oil was 44 % (wt/wt dry PMS without ash) at 340 °C with simply compound composition. And the bio-oil product has above 26 % long chain hydrocarbon and 22 % cycloketones. It has potential for conversion to biomass platform compounds. It can be used as bio-fuel for heat recovery of alkali recovery system of paper mill. So, adjusting different reaction temperatures of HTL, the properties of products can meet the different requirements for platform chemical and/or bio-oil fuel.

The development of microfluidic devices for point-of-care (POC) testing has been widely applied for food quality control, environmental monitoring, and clinical diagnoses. Regarding the latter, microfluidic paper-based analytical devices (µPADs) have a great potential in developing portable and disposable platforms for fast disease-relevant biomarker detection in remote areas. In this work, k-nearest neighbors (k-NN) classifiers were applied to demonstrate the reliability of using chemical data obtained from µPADs for diagnosis of diseases like diabetes mellitus and hyperuricemia. Predictors based on glucose, lactate, and uric acid biomarkers were evaluated to reach this goal. Healthy adults were differentiated from the diagnosed patients with a perfect success rate. Metabolic disorders were suitably predicted with 95.0% overall accuracy. This model also showed sensitivities and specificities in the ranges 75–100% and 93–100%, respectively, indicating that the classification protocol is robust. The k-NN modeling proved the potential of the µPADs to be applied in telemedicine for reliable off-site diagnoses.

Electrochemiluminescence (ECL) is a powerful technique with the advantages of high sensitivity and a wide dynamic range. However, most of previous strategies based on ECL could only detect one analyte so that it is inevitable to investigate the selectivity and influences of interferences. Herein ECL integrated with paper chromatography was showed to be a potential platform for separation and detection of two environmental hormones (bisphenol A, BPA, and dibutyl phthalate, DBP). In our approach, carbon conductive tape was attached to an ITO glass and then modified with multi-walled carbon nanotubes (MWCNTs) and CdSe quantum dot (CdSe QDs) to fabricate the working electrodes for ECL detection. The synthesis of CdSe QDs was optimized based on their photoluminescence spectra and the ECL intensities. The modified electrode was then coupled in the paper-based analytical devices consisting of the filter paper modified with chitosan. Based on their quenching effect on the ECL emission of CdSe QDs, excellent linear relationships could be obtained between decreased ECL intensities and both the concentrations of DBP and BPA. Besides, DBP and BPA could be separated based on their retention time by tilting the filter paper for 30° and then detected with ECL. This study suggested that paper-based analytical devices could be potentially applied for separation and detection of multiple targets due to their ease of fabrication and convenient operation.

The study sought to examine the complexities involved in the implementation of public–private partnerships in the transport sector using the experience of Intercity STC Coaches Limited and private partners in Ghana. The study seeks to contribute to the literature on public–private partnership by examining the implementation challenges associated with the partnership between a public and private transport entities. An exploratory qualitative design through semi-structured interviews and document reviews is adopted for the study. The paper uses the complexity of joint action as the theoretical framework. The study contends that the presence of a challenge, the threat of a challenge or the quest to realize an untapped opportunity offers the basis for a PPP to kick-start. Despite the ideals, there are challenges which impede the effective operationalization of partnerships. These are discussed with clear policy suggestions to address them.

To develop functional honeycomb plates (HPs) with great thermal performance, This paper uses a heat flow meter to determine the equivalent thermal conductivity λ E of honeycomb plates (HPs) positioned horizontally under cold-above/hot-below conditions and combined with theoretical calculations, the influence mechanism of their geometric parameters on their heat transfer performance were investigated with different thicknesses h and cell wall lengths of 8 mm and 16 mm (HP8 and HP16, respectively). The results show that the thermal insulation performance of HPs with different cell side lengths varies with the plate thickness. HP8 presented a better thermal insulation performance when h = 40–60 mm. Based on this, the concepts of matching honeycomb structure and matching convection and the suggestions that according to the needs of a project, HP8 or HP16 can be reasonably selected, and the stacking of two kinds of plates can be optimized were first proposed. And it can be obtained that if the experimental λ E results of a HP are applied to a beetle elytron plate with the same thickness and honeycomb structure size, the heat insulation of the beetle elytron plate (BEP) would be superior to that of the HP. This paper lays a theoretical foundation for the research and development of multifunctional BEPs with heat insulation properties was verified. Finally, the internal influence mechanism of the difference in temperature distribution on the upper and lower surfaces and the three-dimensional size of the honeycomb cells on the matching honeycomb structure and matching convection.

This paper analyses over 89,000 documents between scientific journals and international patents in order to identify main technologies for material pyrolysis (i.e. fluidized bed, hot balls, microwave, plasma, and laser), compare them in terms of technical performances and discover future trends. The predictive model for future trends is based on the evolutionary model of the TRIZ theory, with particular attention to the evolutionary law, “from macro to micro”, which explains how technical systems evolve towards increasingly smaller, controlled, and resource-efficient interactions. In our case, we applied the focus to the interface between the heat source and the pyrolyzed raw material. The proposed evolutionary model showed a substantial alignment with chronological trends, and the model was consistent with both patent trends and those of the scientific literature. To make the analysis quantitatively more robust, a comparison of the different technologies has also been introduced in terms of percentage distribution and the number of patents/papers referring to the different classes of heating rates and reaction temperatures and types of flash/fast/intermediate/slow reaction. Finally, a quantitative metric based on the innovation index has been adopted, to take into account the number of citations normalized on the years of publication. The main outputs of this study identified that radiations-based pyrolysis, involving microscopic interaction, seem more interesting in term of technical performances (i.e. heating rate and reaction temperature), although their technological growth has yet to occur, unlike fluidized bed and hot balls, which typically work at a macroscopic level and seem to have already reached maturity. According to a bibliometric index, laser corpus resulted three time more innovative then fluidized bed reactors papers, especially for heating rates and reactions temperature.

Rational design of photoelectrode architectures is deemed as an effective solution to enhance efficiency of photoelectrochemical water splitting for conquering increasingly prominent environmental problems. Herein, a programmable flexible photoanode with built-in tandem Z-scheme configuration fabricated by in-situ growth of MoSe2-CdS-ZnO array with ultrathin nanosheet-interlaced-nanorod structure on the Au paper electrode, is firstly reported. By taking advantages of the interwoven nanonetwork structure, high conductivity as well as larger porosity of the as-fabricated Au paper electrode, a stable light-harvesting paper chip with fast transfer/separate mediators of the charge/carriers is thus integrated. By virtue of double internal electric fields (IEFs) and photothermal effect, the developed MoSe2-CdS-ZnO photoanode exhibits incident-photon-to-current efficiency of 52 % under 460 nm of light irradiation, and the current density reaches 2.4 mA cm−2 at 0.3 V versus normal hydrogen electrode, which is comparable with respect to current state-of-the-art “type-II-scheme”, “surface-scheme”, and cocatalyst-free photocatalysts (0.03–2.4 mA cm−2). Consequently, the paper-based photoanode achieves admirable photoelectrocatalytic hydrogen generation property (39.7 μmol cm−2 h-1). The synergistic effect of tailorable tandem Z-scheme configuration with double IEFs and delineating of 3D cross-linked network structure of the proposed photoanode in this work may open an avenue for constructing high-performance photoelectrochemical water splitting devices.

We preliminarily examined whether it is possible to visualize synthetic materials applied to the surface of a base material by using near-infrared hyperspectral imaging at wavelengths of 1.0–2.35 µm. We focused on the applicability of this method for visualizing adhesives and varnishes, assessing the effect of underlying colorants on measurements, and selecting the optimal method for data analysis. Experimental samples were adhesive on a painted ceramic plate and varnish on printed paper. We performed correlation analysis, partial least squares regression analysis, linear discriminant analysis, decision tree, KNN and principal component scores 1 and 2 to evaluate the measurement data. The conventional method (visible/near-infrared spectroscopic/fluorescence photographs at wavelengths of 400–1000 nm.) could not visualize the adhesive on the painted ceramic plate or the varnish on the printed paper, whereas the new method could do so. Therefore, this method has the potential to be useful for inspecting the distribution of synthetic materials on the surface of a base material.

Bacteria identification has predominantly been conducted using specific bioreceptors such as antibodies or nucleic acid sequences. This approach may be inappropriate for environmental monitoring when the user does not know the target bacterial species and for screening complex water samples with many unknown bacterial species. In this work, we investigate the supervised machine learning of the bacteria-particle aggregation pattern induced by the peptide sets identified from the biofilm-bacteria interface. Each peptide is covalently conjugated to polystyrene particles and loaded together with bacterial suspensions onto paper microfluidic chips. Each peptide interacts with bacterial species to a different extent, leading to varying sizes of particle aggregation. This aggregation changes the surface tension and viscosity of the liquid flowing through the paper pores, altering the flow velocity at different extents. A smartphone camera captures this flow velocity without being affected by ambient and environmental conditions, towards a low-cost, rapid, and field-ready assay. A collection of such flow velocity data generates a unique fingerprinting profile for each bacterial species. Support vector machine is utilized to classify the species. At optimized conditions, the training model can predict the species at 93.3% accuracy out of five bacteria: Escherichia coli, Staphylococcus aureus, Salmonella Typhimurium, Enterococcus faecium, and Pseudomonas aeruginosa. Flow rates are monitored for less than 6 s and the sample-to-answer assay time is less than 10 min. The demonstrated method can open a new way of analyzing complex biological and environmental samples in a biomimetic manner with machine learning classification.

Exploring novel photoactive materials with high photoelectric conversion efficiency plays a crucial role in enhancing the analytical performance of paper-based photoelectrochemical (PEC) biosensor. SnO2, which possesses higher photostability and electron mobility, can be regarded as a promising photoactive material. Herein, paper-based one dimensional (1D) domed SnO2 nanotubes (NTs) have been developed with the template-consumption strategy. What’s more, their growth mechanism has also been proposed based on the controllable experiments. At first, the paper-based 1D ZnO nanorods (NRs) as the typical amphoteric oxide are prepared and serve as the sacrifice templates which can be etched by the generated alkaline environment during the formation of SnO2. At a certain stage, all the ZnO NRs can be completely etched by controlling the experimental conditions, resulting in the forming of vertically distributed hollow SnO2 NTs. Furthermore, the Sn self-doping strategy is also proposed to suppress the recombination of charge carriers and broaden the light response range by introducing the impurity energy levels. Profiting from such doping strategy, the prominent photocurrent signal is obtained compared with pure paper-based SnO2 NTs. Ultimately, an innovative visible light responsive paper-based Sn-doping SnO2-x NTs are developed and employed as the photoelectrode for the PEC biosensor using the alpha fetoprotein (AFP) as the model analyte. Under the optimal conditions, the ultrasensitive AFP sensing is realized with the linear range and detection limitation of 10 pg mL-1 to 200 ng mL-1 and 3.84 pg mL-1, respectively. This work provides a judiciously strategy for developing novel photoactive materials for paper-based PEC bioanalysis.

Nowadays, multi-functional systems driven by solar energy have been explored to alleviate the crisis of energy and freshwater scarcity. However, it remains a great challenge to integrate multi-functions into one hybrid system with a monolithic material, which can harvest, convert and store solar energy synergistically. Here, we firstly propose a multi-functional carbon nanotube paper, which starts from a material level to solve these problems. The carbon nanotube paper is fabricated by vacuum filtration. It exhibits high efficiency of solar-thermal conversion. Secondly, three types of energy conversion/storage systems (e.g., solar-thermal evaporation system, solar-thermoelectric generation system, and supercapacitor) are constructed based on the carbon nanotube paper, which extend the research to a device level. The solar-thermal evaporation system shows an evaporation rate of 1.28 kg m-2h−1 under simulated sunlight irradiation of 1 kW m−2. The solar-thermoelectric generation system demonstrates a stable electric power generation with an output voltage of 100 mV under light irradiation of 1 kW m−2. The supercapacitors perform the energy storage function with an areal specific capacitance of 19.6 mF cm−2. These devices and systems can be used in freshwater generation (0.84 kg m-2h−1, sunlight irradiation of 1 kW m−2), water purification/desalination (inorganic ions rejection larger than 99.9%) and portable solar charging system (maximum output voltage of 5 V). Finally, a hybrid energy system is innovatively proposed from the system level to simultaneously produce freshwater, generate and store electric power. Through the synergetic coupling of solar conversion and storage technologies, the hybrid energy system can supply sustainable freshwater and electricity for remote areas in daily life, highlighting the superiority of multi-energy (thermal energy, electrical energy, and electrochemical energy) complementary.

Creatinine is a clinically significant analyte used to diagnose kidney condition. However, the literature still lacks in creatinine sensors fulfilling point-of-care testing requirements. In this paper, we have developed colorimetric paper-based creatinine sensors adhering to point-of-care testing principles. The signal readout is accomplished with a smartphone modified with 3D-printed elements and processed with a self-written application compromising computer vision algorithm for automatic detection of the colored zone. Two colorimetric methods – routinely used Jaffe method and an alternative one with 3,5-dinitrobenzoic acid were both tested and compared. Hue channel intensity from HSV color space and green channel from RGB color space was used as the analytical signal in Jaffe and 3,5-dinitrobenzoate method, respectively. For both kinds of sensors the linear range of the response covered the range significant for urinary analysis, with precision, expressed as RSD, below 5%. Limit of quantification for Jaffe method was 1.05 mmol·L−1 whereas it was 0.82 mmol·L−1 for 3,5-dinitrobenzoate method. The utility of the developed sensors to selectively quantify creatinine in undiluted urine was proved using artificial urine samples and the obtained recoveries were in the range from 70 to 129 %.

Considering the large amount of cement consumed in construction and that straw and other renewable resources are discarded in considerable amounts every year, the heat transfer mechanism of solid-core functional paper honeycomb plates (FHPs) was investigated by calculating and analyzing the equivalent thermal conductivity λE of honeycomb plates (HPs) to develop functional sandwich plates and realize the utilization of straw as a resource. The results led to the following conclusions: (1) Under normal temperatures and hot-above/cold-below conditions, radiative heat transfer, which is usually neglected under normal temperatures, was the primary heat transfer mode in HPs. (2) Local convection occurred in HPs due to weak disturbances when the plate thickness h was greater than 15–20 mm. Accordingly, a technical approach was proposed for improving the heat insulation performance of HPs through multilayer substitution. (3) The filling materials could effectively prevent radiative and local convective heat transfer by drastically reducing the cavity size in the honeycomb structure. The heat conduction among solid particles had little influence on the λE of the FHPs. This paper lays a theoretical foundation for studying the heat transfer mechanism of FHPs at normal temperatures.

Mercury (Hg) is a kind of the most common heavy metals with high toxicity in nature, existing in water, soil, and even food. Hence, it is of great importance to develop a simple, effective way to detect Hg2+. Flexible sensing has attracted extensive attention in recent years, which can be flexibly applied in various detection environments. Poly(3,4-ethylenedioxythiophene) (PEDOT) with conjugation structure which can accelerate the transfer of electrons and inhibit the recombination of carriers is favorable to the photoelectrochemical (PEC) process. Here, Br doped PEDOT modified carbon paper with narrower bandgap was firstly fabricated through situ thermal polymerization which exhibited high photocurrent intensity under visible-light irradiation. The success synthesis of PEDOT was confirmed by SEM, XPS, FT-IR and Raman spectrum. Meanwhile, the as-prepared electrode can be mass produced with good reproducibility. Based on excellent performance of as-prepared electrode of Br doped PEDOT/carbon paper, we constructed a PEC sensing platform for Hg2+ detection with the detection limit of 0.3 nM and linear range from 1 nM to 450 nM. In addition, the PEC sensor exhibited speedy response, outstanding stability, excellent selectivity, wide linear range, and was used for determination of Hg2+ in river water samples with recover range of 97.7–104.5 % and RSD of 2.8–4.7 %.

Flexible all-solid-state supercapacitors (FASSCs) have attracted much attention as power supplies for portable and wearable electronic products. Herein, we report the fabrication of a foldable, extra lightweight, flexible chopped carbon fiber paper (CFP) with a porous network structure prepared via wet-mold papermaking that can serve as a conductive substrate. The conductivity and pseudocapacitance of the electrode were improved by controlling the growth of 3D Cu(OH)2 nanorod arrays on CFP substrate. The Cu(OH)2@CFP electrode has a high specific capacitance of 421.8 mF cm−2 at a current density of 0.5 mA cm−2 with capacitance retention of 82.98% at a current density of 10 mA cm−2 after 5000 charge-discharge cycles. The FASSC manifested not only a large capacitance of 196.1 mF cm−2 at 2 mA cm−2, as well as energy and power densities of 6.97 × 10−2 mWh cm−2 and 1.6 mW cm−2, respectively, but also excellent stability of 80.3% over 5000 cycles at 5 mA cm−2. In addition, we confirmed that the FASSC has a large bending angle and can be twisted into various shapes, thereby indicating its applicability in portable and wearable electronic devices.

A single-sheet 3-dimensional paper-based microfluidic analytical device (3D-μPAD) has a user-friendly compact format that eliminates any potential for user alignment error compared to the stacking and folding format. However, achieving sophisticated analysis is still a challenge because forming a complex 3D microfluidic network sufficient for performing analysis in a single sheet of paper is difficult. Here, we present the first report of automatic multistep digital analysis in a single-sheet 3D-μPAD created by controlling the penetration of different wax inks into paper. Simple printing of different wax inks with different spreading properties produces different dimension microchannels in paper. This controllable change in the dimensions of the microchannels results in different flow rates of fluid in each microchannel. Based on the spatial resolution of the microchannels, our strategy enables programming of microfluidic flow through manipulation of the fluidic time delay. This approach creates 3D-μPADs capable of sequential fluid delivery and multistep biochemical reactions with single loading of a sample solution. The methodology can be further expanded to combination with digital assays to measure the concentration of a target analyte by simply counting the number of colored bars at a fixed time. It does not require any external instruments to analyze the measurement of the target analyte concentration. The significance of this work lies in the promising potential for automatic multistep digital assays in a low-cost and easy-to-use paper-based format that can be integrated with a roll-to-roll process for commercial-scale manufacturing.

Paper-based microfluidic devices are an attractive option for developing low-cost, point-of-care diagnostic tools. To incorporate more complex assays into paper, these devices must become more sophisticated, through the sequential delivery of different liquids or reagents without user intervention. Many flow control strategies focus on slowing the fluid down. However, this can lead to increased assay times and sample loss due to evaporation. We report the use of a CO2 laser to create etched grooves on paper to accelerate wicking speeds in paper-based microfluidic devices. We explored different laser settings to determine the optimal configuration. Our findings showed that simply cutting a slit into the paper created the fastest wicking channels. The slit acted as a macro capillary, allowing fluid to bypass the paper and speed it up. Further studies determined an ideal groove pitch of 0.75 mm (spacing in between grooves) for a paper channel. Additional experiments documented how sealing grooved channels with different adhesives can influence wicking. Overall, sealing the channels with tape made them wick faster. However, sealing methods such as lamination had a negative effect on wicking. Laser-etched grooves were successfully used to design a fluid-handling architecture for a chemiresistive paper-based biosensor. The grooves facilitated rapid, sequential delivery of sample and wash buffer. Human serum albumin spiked in phosphate buffer, artificial urine, and artificial saliva was successfully detected at as low as 15 pM. Etching grooves in paper is a simple process that requires no additional materials or chemicals, allowing single-step fabrication of paper-based microfluidic channels.

Lithium-sulfur batteries are promising candidates for powering flexible devices with high energy densities. To realize both high areal and volumetric capacity of lithium-sulfur batteries, while maintaining flexible and mechanically robust characteristics, is challenging for their portable energy storage applications. Herein, interface covalent bonding was demonstrated to design densely-packed graphene/CoS2/nano-sulfur hybrid papers with flexible and robust characteristics for energy-dense, compact and foldable lithium-sulfur batteries. The as-designed paper cathodes showed excellent cycling stability with a low decay rate of 0.044% per cycle over 800 cycles at 1 C, as well as high reversible areal capacity (4.11 mAh cm−2) and volumetric capacity (1240 Ah L−1). Meanwhile, the assembled batteries performed a high gravimetric/volumetric energy density (363.5 Wh kg−1/378 Wh L−1) under high sulfur loading (5.6 mg cm−2) and lean electrolyte/sulfur ratio (E/S: 5 μL mg−1). Furthermore, durable pouch cells based on as-designed integrated paper cathodes showed negligible performance decay even at a folding angle of 180°, highlighting their practical applications for flexible power systems.

To develop functional sandwich plates (FHPs) and identify new ways to use straw, straw-core paper honeycomb plates (SHPs) were prepared. The mechanisms of the influence of the spatial distribution of various filling systems on the heat transfer performance of SHPs were investigated, and the following results were obtained. 1) The equivalent thermal conductivity (λE) of the three FHPs were significantly lower than that of the honeycomb plate (HP), and the λE of all the FHPs met or approached the requirements of high-efficiency heat insulation materials for envelope structures. Moreover, the λE values of the three FHPs were closest to each other at the upper and lower limits of the tested thickness. 2) The spatial distribution characteristics of the spherical particle and slender filling systems under natural filling conditions, their corresponding simple heat transfer models and the concept of divisional local radiative (DLR) heat transfer were presented for the first time. 3) The fundamental factor determining the magnitudes of the λE of the HP and FHPs was the presence of DLR in the core layer structures, and the heat transfer characteristics of the FHPs were the result of the combined actions of the DLR and filling material properties.

In a circular economy, extended producer responsibility (EPR) is a regulatory approach that accounts for all environmental costs associated with a product throughout its life cycle. When considering the EPR, the regulator must (1) design an integrated framework for different stakeholders and (2) provide effective policies to create financial incentives to accelerate the circular system. Recycling funds and subsidies are the most prominent financial strategies that can either encourage or curtail the flows of recycled products. In Indonesia, a few companies provided recycling bonus s to their customers as incentives to increase the recycling rate. However, the recycling rate was not as effective as expected by the enterprise because recycling was practiced by a limited number of companies, rendering it economically unviable. The enterprises hope the government could develop a recycling fund system. In order to develop the recycling fund system, a system dynamic model was proposed and simulated to optimize the recycling funds and subsidies based on decentralized reverse supply chains. Although it is not a novelty model; however, the research show a very significant results for the government in Indonesia. This enabled a more precise, well-planned, and sustainable decision-making process for the EPR. In addition, by utilizing the system dynamic model with different scenarios in a real case study (aseptic paper packaging waste), we found that the capacity of the recycler could become the reference for the funds to be paid by the importer-producer group, wherein the recycling rate will increase with an increase in the recycling fund.

This review paper provides a key information, allowing readers to comprehensively understand the direct tensile behavior and test methods for textile reinforced cementitious composites (TRCCs). The tensile parameters of TRCCs corresponding to bilinear or trilinear tensile stress–strain behavior were summarized and the influencing factors on the tensile parameters were discussed. Various direct tensile test methods for TRCCs were evaluated according to the geometry of specimens, load transmitting mechanism, measurement and loading methods. Conclusive requirements for a standard test method for assessing the tensile stress–strain behavior of TRCCs were proposed.

Biorefinery is pivotal to the sustainability of modern chemical industry. However, since biomass is oxygen-enriched, new and green chemical strategies are required for expanding the biomass derived chemical space. In this work, synthesis of natural products dihydrocapsaicin and dihydrocapsiate was achieved exclusively from lignocellulosic platform chemicals. Natural products dihydrocapsaicin and dihydrocapsiate were synthesized exclusively from lignocellulosic platform chemicals, using furfural (from hemicellulose) and methyl isopropyl ketone (from cellulose) through aldol condensation-hydrolysis-hydrodeoxygenation to synthesize 8-methylnonanoic acid and then combined with vanillin derivates (from lignin). This synthesis demonstrates the feasibility of constructing natural products entirely from renewable biomass platform through green processes. The utilization of inherent functional groups of biomass demonstrates their potential to open up chemical space.

Flexible thermoelectric materials are presented with potential applications in electronic devices and energy conversion due to their convenient preparation, good flexibility, and various forms. However, as ductility is rarely observed in inorganic semiconductors and ceramic insulators, reports on applications of inorganic oxide materials in flexible thermoelectric materials are sparse. Here, we report a new method for the synthesis of a flexible Na1.4Co2O4 thermoelectric material based on Na1.4Co2O4 bulk materials, which are prepared by a self-flux method and painted on print paper. Seebeck coefficient and power factor of the obtained thermoelectric material are 78–102 μVK-1 and 159–223 μWm-1K-2, respectively, in a temperature range of 303–522 K, which are superior to those values of other conductive polymers and their compounds. More interestingly, the n-type Na1.4Co2O4 flexible material is obtained in the painting process at higher pressure with Seebeck coefficients of –109 to –183 μVK-1 in a temperature range of 303–522 K. The convenient preparation method of these novel flexible thermoelectric materials may be expanded to the synthesis of other flexible thermoelectric materials, which will be the focus of future work.

COVID-19 has forced government and health agencies to take measures to mitigate the spread of the disease and thus safeguard as many lives as possible. These measures have initially impacted the economy of many countries, and therefore they have been forced to gradually return to a new normalcy, in what they have called reopening. For reopening policies to be effective, it is necessary that the people in charge of drawing up these policies know the local behavior of the propagation of COVID-19, and beyond this they can understand that between the cases of COVID-19 and the socioeconomic conditions of their population there is a relationship. For this reason, in this article a case study is presented, which allowed to evaluate the relationship between positive cases of COVID-19 and the multidimensional poverty index (MPI) in the city of Manizales, Colombia. The results of an exploratory analysis, obtained with the use of remote sensing data, are presented, which allowed to confirm the relationship in mention, and it is hoped that this can serve the municipal administration in its decision making.

In recent years, agricultural wastes cause serious pollution to the environment. Agricultural residues can be used to produce value-added products in order to control environmental pollution, therefore these wastes are a promising feedstock as it has many advantages such as wide range of source, low cost and renewable. Rice straw and lemongrass leaves which are the renewable sources for the production of many useful products such as xylose. The aim of this study is to compare the content of xylose produced from rice straw and lemongrass leaves, in order to obtain highest yield of xylose and to optimize the acid hydrolysis time, concentration of sulphuric acid, liquid–solid ratio and the power of the microwave towards the maximum extraction of xylose. Microwave assisted acidic hydrolysis method was used to extract xylose from rice straw and lemongrass leaves. The acid hydrolysis of both rice straw and lemongrass was performed at different time (1–5 min), acid concentration (1%–5%), liquid solid ratio (1:30, 2:30, 3:30, 4:30 and 5:30) and power (160 W, 320 W, 480 W, 640 W, 800 W). The results obtained indicate that the yield of xylose from rice straw (2.98 g/L) via the microwave assisted is slightly higher than lemongrass (2.91 g/L) with optimum conditions of 3 min of hydrolysis time, 2% of sulphuric acid concentration, 1:30 of liquid solid ratio and 320 W of microwave power. Meanwhile, the optimum conditions for lemongrass leaves are 4 min of hydrolysis time, 4% of sulphuric acid concentration, 2:30 of liquid solid ratio and 480 W of microwave power. Thus, rice straw has slightly higher capability in production of xylose compared to lemongrass.

The alternative and renewable sources of energy are very much essential to reduce the dependency on fossil fuels and also to control the environmental pollution. One of the important renewable sources which replace the fossil based fuels is biodiesel. The biodiesel is highly influenced by fatty acid composition. Hence, in the present work Salvodara persica nonedible seed oil (38% oil content) which is rich in saturated fatty acids (79.16%) is mixed with Leucas aspera nonedible seed oil (22.50% oil content), which is rich in unsaturated fatty acids (90.72%) in equal proportion (1:1). The mixed seed oil fatty acid profile is analyzed by GC-FID which shows that, it is exactly half of the fatty acid profile of individual seed oils (saturation 45.26% and unsaturation 54.74%). Bio-mixed oil is transesterified and the biodiesel produced is characterized for its fuel properties. The fuel properties of biodiesel produced from mixed seed oils is compared with biodiesel from individual seed oils, already existing biodiesels and biodiesel standards. It reveals that better quality biodiesel is produced by mixing seed oil strategy. Even the emission analysis shows that the emissions are reduced except NOx. This work reveals that it is one of the important criterions to improve the biodiesel quality by mixed seed oil strategy.

Textile industry represents a pollution problem worldwide due to the accidental discharge or dumping of polluted wastewater into the waterways, which is having a major influence on the quality of water resources. Around 17–20% of industrial water pollution arises from textile dyeing and treatment according to the World Bank report. This represents a large environmental challenge for textile manufacturers. With growing environmental awareness, there is a need for environmentally-friendly technology to remove dyes from the industrial and local wastewater. The photo decolorization of dyes is considered as a favorable technology for industrial wastewater treatment techniques owing to its environmentally friendly method, low cost, and lack of secondary pollution. The efficiency of photocatalysis system depends on the operational parameters that govern the adsorption and photodegradation of dye molecules. This comprehensive review examines the operational factors influencing the photo decolorization of dye molecules. Our study aims to review and summarize the previously published works and R&D progress in the field of photocatalysis of various water pollutants such as the toxic organic compounds (cationic and anionic dyes) using various semiconductor nanoparticles under visible, solar and UV irradiation. This paper examines the effects of operating parameters on the photocatalytic degradation of textile dyes using various photocatalysts. Our findings showed that various parameters, like initial pH of the solution to be degraded, photocatalyst concentration, reaction temperature, dye concentration and dopants content exert their individual influence on the photocatalytic degradation of any dye. By investigating previous research to elucidate the most significant active species for optimal photo decolorization reactions, this review provides guidelines that can be applied to the development of effective photodegradation systems. The results of our study will help determine the most effective and economical options for removal of dyes in industrial wastewater.

Considering that conventional fossil fuels have limited resources and are not environmentally friendly, while energetic demand grows exponentially, the searching for alternative energetic supply is becoming more and more attractive. Biodiesel is considered an alternative energetic supply reality and is composed by fatty acids methyl esters obtained through esterification and/or transesterification reactions. Although a reality, the increase in use of biodiesel depends on lowering its production costs. In order to reach this goal, this paper describes a way to produce a low cost catalyst for biodiesel production by egg shell calcination, as well as demostrate paremeters optimum conditions by statistical analysis. Biodiesel samples were produced from macauba seed oil and methanol using an egg shell catalyst in a batch reactor. Parameters such as oil/methanol molar ratio, catalyst amount and temperature were evaluated for biodiesel conversion yield. The results were considered satisfactory as the esters conversion yield reached about 91% and parameters study revealed the stronger influence of temperature and catalyst content in ester conversion.

Non admixed Natural gas-fuelled diesel engines are usually associated with harsh engine emissions as well as low performances at moderate to high engine loads. However, the use of Moringa biodiesel as additive in hydrogen-compressed natural gas (HCNG) is a viable novel strategy for reducing toxic emissions such as hydrocarbons and nitrogen oxides in CI engines. In this study, five hybrid HCNG–Moringa biodiesel (MB) oil samples labelled A–E were analysed for their abilities to improve the overall performance of a CI engine (Petter PH1W diesel engine). The fuels had a fixed volume by volume hydrogen : carbon ratio of 87:13% respectively, and the HCNG–MB hybrid samples consisted of 0, 5, 7, 10 and 13 %v/v MB for samples A, B, C, D and E, respectively. At higher engine loads (i.e. 58%–100%), the engine performance improved thus giving higher BTEs in the range of 19–33.9% for all the fuel blends relative to the BTE (15.1%–19%) of the unblended HCNG fuel; this confirms the suitability of MB as an additive for improving the brake thermal efficiency of CI engines; there were also reductions in HC, O2, CO2, CO and NOx emissions for all the MB–HCNG fuels relative to the case of the unblended HCNG fuel. At optimum condition, the fuel that gave the best results in terms of the aforementioned engine characteristics is the MB–HCNG fuel blend having 10% MB.

Life cycle assessments of fuel bioethanol produced in Uruguay from liquid hot water pretreated switchgrass were performed for two scenarios: the production of ethanol and electricity and a biorefinery producing ethanol, electricity, furfural, acetic, and formic acid. Experimental data and material and energy balances derived from the simulations were used to analyze the global warming potential of fuel bioethanol. Greenhouse gas (GHG) emissions in both scenarios were lower than the reference emissions for fossil fuel. The biorefinery scenario had a better performance in terms of environmental impacts, and the biofuel produced met GHG reduction requirements. Switchgrass composition, enzyme dosage, fermentation and hydrolysis efficiency, and solids content had a significant effect on environmental performance, with enzyme use being the most significant factor. A multi-objective optimization was used to find the values of solid content and enzyme dose that minimize GHG emissions and the minimum ethanol selling price (MESP). An enzyme dosage of 37 mgprotein/gglucan and solids content of 21% w/w were the optimal conditions for bioethanol production with an associated GHG value of 2 ± 5 g CO2 eq./MJethanol and a MESP of $0.84/L.

Biomass can be torrefied to improve the fuel quality prior to its utilization. In addition, a large number of soluble alkali metals can be removed by water washing, to solve slagging and other ash-related problems. In this study, computer-controlled scanning electron microscopy (CCSEM) was used to analyze the mineral composition and elemental distribution of straw, torrefied straw char, and torrefied-water washed straw char. The mineral transformation behavior and the distribution of main elements, when these biomass species were individually co-combusted with coal, were also studied in detail. The comparison of the mineral composition of bulk ash obtained from torrefied straw combustion and straw combustion revealed that the quartz phase decreased and the aluminosilicates of K-, Na-, and Ca–Fe–K increased in the former compared to that in the latter. After the torrefied straw was washed with water, the quartz and Si-Rich phases increased. K aluminosilicate decreased and the quartz phase increased when the torrefied sample was co-combusted with coal at both mixing ratios of 1:1 and 1:4 compared to straw/coal co-combustion. When the torrefied-water washing sample and coal were co-combusted at a 1:1 ratio, the quartz phase decreased, and the Si-Rich and mullite phases increased. When the straw/torrefied char/torrefied-washed char was co-fired with coal at the 1:4 ratio, the amount of K aluminosilicate was less compared to that observed at the 1:1 ratio. It can be concluded that both torrefaction and torrefaction-washing can reduce the content of low-melting-point aluminosilicates in the mineral composition of the studied biomass after co-combustion, which can be beneficial to alleviate the ash slagging problem.

In the 21st century the academic field of Child–Computer Interaction (CCI) arose alongside burgeoning interactive technology and digital media industries that targeted children. We believe that the field of CCIU is at an important point in its development, analogous to when a child becomes a teen. Over the last few years we have each had many informal conversations with other CCI researchers in which we discuss issues such as, what is our responsibility as researchers beyond academe? What values underlie our conceptions of a ”good” childhood and the role of interactive technology in it? And, how do we ensure that our field continues to grow and evolve in ways that are consistent with our responsibilities and values? To address these and other complex questions that have been drawing our attention we came together to reflect, discuss and create a position paper for our community, in which we outline some of the issues we see facing our community at this time. To inform our deliberations with opinions beyond our own we conducted an informal consultation with 25 members of the CCI community. Our responders spanned junior to senior researchers, represented diverse geographies and included industry practitioners. These diverse responses provided further content for our reflections, and helped us see perspectives beyond our own. The result of this informal process is this speculative paper in which we propose a series of seven provocations that aim to disrupt some of the normative assumptions held in our field. Our goal in doing this is to open up dialogue in our community about these issues and promote consideration of the alternative visions we present for where we might focus our attention and efforts. We see our contribution not as truth or a definitive statement of a vision for the field, but rather as our opinion about some of the complex issues we face and that we think should be considered through dialogue as we move into the next phase of our development as an academic and scholarly community. We believe that it is urgent and critical for our field that we take up these questions, explore diverse perspectives, and critically work towards decisions and actions that will define our identity and the value of our contributions as we move forward into the next 20 years of research in CCI.