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In this study, Taguchi experimental design was used to the optimize operating parameters for the degradation of paper mill effluent using electrochemical (EC) process with two-dimensional concentric aluminum tube electrodes (CATE). For this purpose, four significant experimental factors were used in four levels pH (6–9), electrolysis time (10–40 min), voltage (6–12 V) and surface area (357–624 cm(2)). The process parameters were optimized, through performing L16 orthogonal array of Taguchi technique, for the removal of chemical oxygen demand (COD) and turbidity. The percent COD and turbidity reductions were transferred into an accurate S/N ratio for a larger value is the better (LBT) response. The study presents a unique method of finding optimum combination of process parameters to illustrate their effect on the turbidity and COD reduction. The treatment conditions for the maximum elimination of the pollutants were second level of pH (7), third level of ET (30 min), fourth level of voltage (12 V) and second level of surface area (446 cm(2)). The confirmation experiment results were within the confidence intervals (CI) indicating an acceptable agreement between predicted and observed values. Based on the p-values, the electrolysis time and voltages were found to be the most significant factors for both COD and turbidity reduction. The findings of research indicated, that the Taguchi method can be used successfully for the treatment of paper industry effluent by electrochemical technique.

Flexible paper-based sensors may be applied in numerous fields, but this requires addressing their limitations related to poor thermal and water resistance, which results in low service life. Herein, we report a paper-based composite sensor composed of carboxylic carbon nanotubes (CCNTs) and poly-m-phenyleneisophthalamide (PMIA), fabricated by a facile papermaking process. The CCNT/PMIA composite sensor exhibits an ability to detect pressures generated by various human movements, attributed to the sensor's conductive network and the characteristic "mud-brick" microstructure. The sensor exhibits the capability to monitor human motions, such as bending of finger joints and elbow joints, speaking, blinking, and smiling, as well as temperature variations in the range of 30-90 °C. Such a capability to sensitively detect pressure can be realized at different applied frequencies, gradient sagittas, and multiple twists with a short response time (104 ms) even after being soaked in water, acid, and alkali solutions. Moreover, the sensor demonstrates excellent mechanical properties and hence can be folded up to 6000 times without failure, can bear 5 kg of load without breaking, and can be cycled 2000 times without energy loss, providing a great possibility for a long sensing life. Additionally, the composite sensor shows exceptional Joule heating performance, which can reach 242 °C in less than 15 s even when powered by a low input voltage (25 V). From the perspective of industrialization, low-cost and large-scale roll-to-roll production of the paper-based sensor can be achieved, with a formed length of thousands of meters, showing great potential for future industrial applications as a wearable smart sensor for detecting pressure and temperature, with the capability of electric heating.

Edible oils form an integral component in the human diet as well as in the industrial preparations. Any adulteration in oil is concerning from nutritional as well as economical perspective. Although analytical techniques exist for detection of adulterants in oil, most of them require sophisticated instruments, and trained professionals. Microfluidic based lab-on-a-chip technologies have rapidly progressed over the recent years and offer promising alternatives in this regard. In this work, we report development of a paper-based microfluidic lab-on-a-chip for detection of palm oil contamination in sunflower oil. We use the paper-based microfluidic colorimetric detection approach that indicates the presence of adulteration in a visual manner. The data is analyzed using digitally acquired images along with ultraviolet–visible spectrophotometry. The paper-based microfluidic device is fabricated and tested for 10–50% (v/v) palm oil adulteration in sunflower oil. Further, we employ the device for free fatty acid content tests in oil samples. Visual signal acquired from the device is optimized by varying phenolphthalein proportions. The stability of visual colorimetric signal is examined over time and is found to remain steady over the trial period of six days considered in this work. The integration of the detection device with smartphone imaging can prove to be useful for onsite data collection. We believe the approach presented here can be extended to food quality monitoring portable platforms.

Abstract Tissue paper softness relies on two major factors, the bulk softness, which can be indicated by the elasticity of the sheet, and surface softness. Measurement of surface softness is complicated and often requires a multi-step process. A key parameter defining surface softness is the topography of the surface, particularly the crepe structure and its periodicity. Herein, we present a novel approach to measure and quantify the tissue paper surface crepe structure and periodicity based on the detection of waviness along the sample using laser scanning confocal microscopy (LSM) and X-ray tomography (XRT). In addition, field emission scanning electron microscope (FESEM) was used to characterize the tissue paper surface. We demonstrate that surface topography is directly correlated to the erosion of the doctor blade, which is used to remove the dry tissue paper from the Yankee cylinder. Because of its accuracy and simplicity, the laser confocal microscopy method has the potential to be used directly on the production line to monitor the production process of the tissue paper. XRT revealed more structural details of the tissue paper structure in 3D, and it allowed for the reconstruction of the surface and the internal structure of the tissue paper. Graphic abstract

Objective: To compare the effectiveness of mobile video-guided home exercise program and standard paper-based home exercise program. Methods: Eligible participants were randomly assigned to either experimental group with mobile video-guided home exercise program or control group with home exercise program in a standard pamphlet for three months. The primary outcome was exercise adherence. The secondary outcomes were self-efficacy for exercise by Self-Efficacy for Exercise (SEE) Scale; and functional outcomes including mobility level by Modified Functional Ambulatory Category (MFAC) and basic activities of daily living (ADL) by Modified Barthel Index (MBI). All outcomes were captured by phone interviews at 1 day, 1 month and 3 months after the participants were discharged from the hospitals. Results: A total of 56 participants were allocated to the experimental group [Formula: see text] and control group [Formula: see text]. There were a significant between-group differences in 3-months exercise adherence (experimental group: 75.6%; control group: 55.2%); significant between-group differences in 1-month SEE (experimental group: 58.4; control group: 43.3) and 3-month SEE (experimental group: 62.2; control group: 45.6). For functional outcomes, there were significant between-group differences in 3-month MFAC gain (experimental group: 1.7; control group: 1.0). There were no between-group differences in MBI gain. Conclusion: The use of mobile video-guided home exercise program was superior to standard paper-based home exercise program in exercise adherence, SEE and mobility gain but not basic ADL gain for patients recovering from stroke.

Flexible thin-film solar cells with high weight-specific power density are highly desired in the emerging portable/wearable electronic devices, solar-powered vehicles, etc. The conventional flexible metallic or plastic substrates are encountered either overweight or thermal and mechanical mismatch with deposited films. In this work, we proposed a novel substrate for flexible solar cells based on graphene paper, which possesses the advantages of being lightweight and having a high-temperature tolerance and high mechanical flexibility. Thin-film amorphous silicon (a-Si:H) solar cells were constructed on such graphene paper, whose power density is 4.5 times higher than that on plastic polyimide substrates. In addition, the a-Si:H solar cells present notable flexibility whose power conversion efficiencies show little degradation when the solar cells are bent to a radius as small as 14 mm for more than 100 times. The application of this unique flexible substrate can be extended to CuInGaSe and CdTe solar cells and other thin-film devices requiring high-temperature processing.

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%.

Reflective liquid crystal displays are attracting attention as portable information systems because of zero- or extremely low power consumption. In this study, we deal with an electrode-free reflec...

Microfluidic paper-based analytical devices (μPADs) allow user-friendly and portable chemical determinations, although they provide limited applicability due to insufficient sensitivity. Several approaches have been proposed to address poor sensitivity in μPADs, but they frequently require bulky equipment for power and/or read-outs. Universal serial buses (USB) are an attractive alternative to less portable power sources and are currently available in many common electronic devices. Here, USB-powered μPADs (USB μPADs) are proposed as a fusion of both technologies to improve performance without adding instrumental complexity. Two ITP USB μPADs were developed, both powered by a 5 V potential provided through standard USB ports. The first device was fabricated using the origami approach. Its operation was analyzed experimentally and numerically, yielding a two-order-of-magnitude sample focusing in 15 min. The second ITP USB μPAD is a novel design, which was numerically prototyped with the aim of handling larger sample volumes. The reservoirs were moved away from the ITP channel and capillary action was used to drive the sample and electrolytes to the separation zone, predicting 25-fold sample focusing in 10 min. USB μPADs are expected to be adopted by minimally-trained personnel in sensitive areas like resource-limited settings, the point-of-care and in emergencies. Fil: Schaumburg, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Kler, Pablo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; Argentina Fil: Carrell, Cody S.. State University of Colorado - Fort Collins; Estados Unidos Fil: Berli, Claudio Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Henry, Charles S.. State University of Colorado - Fort Collins; Estados Unidos

The development of renewable energy sources minimizes the burning of fossil fuels for clean and green environment. Electrochemical energy storage/conversion device pays a way towards sustainable development that concludes an emerging field in the trends of the research community. Prominently, the functional materials with suitable structure and property determine the performance and durability of the devices. In recent times, graphene with its tremendous properties play a major role in electrochemical energy device applications. Meanwhile, the graphene-based electrodes were fabricated by various coating techniques on existing electrodes that utilized for energy device fabrication. Apart from these, it is also fabricated in a paper like a form (self-supported or free-standing) with its remarkable high conductivity, flexibility, robustness and electrochemical behavior which have been nominated for fabrication of flexible energy devices. Paper-like electrodes become an emerging field to fabricate a light-weight and flexible electronic devices for future prospects. Thus, we have summarized a synthetic strategy of graphene paper and its properties that potentially focused on flexible device fabrication in both the energy storage and conversion system. Hence, this review boosts up the forthcoming researchers to enhance the device performance with interrelating free-standing graphene and other host material.

In most cases, three-dimensional paper-based microfluidic analytical devices (3D-μPADs) were fabricated manually by stacking or folding methods. For the first time, digital light processing stereolithography (DLP-SLA) 3D printing technology was adopted to automatically make 3D-μPADs. In the fabrication process, a printing pause was set between two layers to allow paper to be placed in the resin tank. The resin on the fresh paper spontaneously bonded to the former cured paper layer during curing, thus realizing the automatic bonding and alignment between different layers of paper and avoiding the human participation and errors as in stacking and folding methods. There was a gap between two vertical aligned flow paths, therefore the liquid did not flow spontaneously from the upper layer to the lower layer. Most of the fluid flow in 3D-μPADs was spontaneous or manually activated, which was not conducive to complex assays that require different regents to be delivered sequentially. Herein, we used an electric field or airflow to trigger the fluid flow and demonstrated the flow controllability by a proof-of-concept colorimetric assay. The limits of detection of glucose and albumin were 0.8 mM and 3.5 μM, respectively, which were sufficient for clinical requirements. Given the characteristic of flow controllability, we believe that the proposed 3D-μPADs have great potential to make paper-based complex assays automated and programmable.

This paper presents a new approach towards the design of paper based autonomous microfluidic devices. Autonomy in the device operation is achieved through the incorporation of mechanically actuated microfluidic switches that are versatile in their design and may be configured to be simple time triggered ON or OFF switches or more complex switches that can be timed to be in multiple states (timed ON, followed by timed OFF). These switches are self-contained and require no external power for their operation, deriving their functionality solely through stored elastic energy. This paper presents the design and fabrication of these switches as fluidic analogs of electronic transistors, and their integration into microfluidic paper based circuit demonstrating their operation as a programmable paper-based microfluidic device.

Although Al-ion battery is attracting researchers’ attention worldwide, its volumetric energy density was not so promising due to low density of graphite-based positive electrodes in the current published literatures. Thus, defect-free yet densely packed graphene electrodes with high electronic conductivity and fast ionic diffusion are crucial to the realization of compacted Al-ion batteries with high volumetric energy density. In the present work, a self-supported and defect-free graphene-positive electrode (RHG-P-2850) was successfully produced by a hydriodic acid reduction of the graphene oxide (GO) method, followed by an ultrahigh temperature (2850 °C) annealing treatment. The density of the RHG-P-2850 (0.32 g cm−3) is currently the highest positive electrode material in the preparation of graphene-positive electrodes from GO. RHG-P-2850 positive electrode enables to deliver considerably high specific capacity 27.1 mAh cm−3 (85 mAh g−1) at the current density 2 A g−1. More importantly, a remarkably stable performance was achieved with 20% fading over 8000 cycles. The results enlighten and promote the design and preparation of densely packed graphene-positive electrode to develop high-performance Al/graphene battery.

Nowadays, the needs of bendable energy storage components are growing to match with the development of wearable devices. However, it is still a great challenge to fabricate flexible electrodes to k...

PurposeThis position paper urges a drive towards clarity in the key definitions, terminologies and habits of speech associated with digital engineering and building information modelling (BIM). The ultimate goal of the paper is to facilitate the move towards arriving at an ideal definition for both concepts.Design/methodology/approachThis paper takes the “explanation building” review approach in providing prescriptive guidelines to researchers and industry practitioners. The aim of the review is to draw upon existing studies to identify, describe and find application of principles in a real-world context.FindingsThe paper highlights the definitional challenges surrounding digital engineering and BIM in Australia, to evoke a debate on BIM and digital engineering boundaries, how and why these two concepts may be linked, and how they relate to emerging concepts.Originality/valueThis is the first scholarly attempt to clarify the definition of digital engineering and address the confusion between the concepts of BIM and digital engineering.

BACKGROUND: Ultrafiltration (UF) technology is efficient in treating wastewater. However, membrane fouling during filtration process affects the performance of UF to a large extent. Pretreatment prior to UF is important for enhancing membrane performance, reducing membrane fouling and extending the membrane lifetime. RESULTS: In this study, two pretreatment technologies, including coagulation and Fenton, were applied individually before UF for treating secondary effluent (SE) from recycled paper mill. Results exhibited that direct membrane filtration got the highest flux loss and worst membrane fouling compared with performances of those conducting pretreatments. Compared to coagulation + UF, Fenton + UF had superior performance in reducing dissolved organics with a COD rejection of 91.81%, and mitigating membrane fouling with a stable flux of 133 J m⁻² h⁻¹. GPC results further showed that Fenton pretreatment degraded macromolecules into smaller organic compounds. In addition, the classical blocking filtration laws were employed to scrutinize the fouling alleviation mechanism of pretreatments. CONCLUSION: Pretreatments prolonged the transition from pore blocking to cake filtration, thereby reducing fouling. Among them, Fenton was a promising pretreatment method prior to UF for treating recycled paper SE. © 2018 Society of Chemical Industry

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.

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.

We propose a paper solar cell based on carbon nanotube (CNT)-composite papers. To fabricate this cell, we use dye-sensitized solar cells (DSCs) for generating power through the redox reaction of dyes in conjunction with CNT-composite papers, which are composite materials containing CNTs and pulp (raw paper material) that can be fabricated easily by using a method based on the Japanese washi papermaking technique. The demand for CNT applications is expected to increase due to their high conductivity and metallic or semiconducting characteristics. This CNT-composite paper can also have metallic or semiconducting characteristics based on the contained CNTs in the composite paper. We previously fabricated a DSC that generates electricity by using CNT-composite papers stacked in a typical DSC structure. However, the conversion efficiency of this DSC was just 0.188%, which is not practical. To overcome this low power generation issue, we tried improving the DSC structure by applying electrodes to the CNT-composite papers in grid patterns for efficient current collection and applying an optimally mixed dye for efficient electron excitation. Results showed that the conversion efficiency improved to 0.58%. Moreover, we demonstrated that using a mixed dye can improve the conversion efficiency of the paper DSC. We expect these types of CNT-composite papers to be used as material for new DSCs.

The construction of a photoelectrochemical (PEC) strategy for multi-component detection represents a great challenge in the field of sensing. To address these challenges, herein we presented a hollow-channel paper-based PEC analytical platform based on chemiluminescence (CL) addressable strategies excited PEC strategy for multiplexed sensing application. Sandwich-structured CdS quantum dots (QDs)/reduced graphene oxide (RGO)/ZnO nanorods arrays (NRAs) heterostructure where CdS serves as visible light sensitizers, RGO acts as an electron relay between ZnO NRAs and CdS QDs, were simply assembled on the gold nanoparticles modified paper working photoelectrode (Au-PWE). The PEC performance of the CdS/RGO/ZnO can be greatly improved benefiting from the formation of type II band alignment between CdS QDs and ZnO NR as well as the super charge collection and shuttling property of RGO. Multiplexed CL emission could be achieved through controlling the CL co-reagents transport. By the virtue of CL addressable technique and the excellent PEC activity of CdS/RGO/ZnO, a highly sensitive, and selective multiple microRNAs (miRNAs) quantification method was achieved. Such a tailored strategy would break the bottleneck of the current PEC detection techniques in multiplex tracing, as well as serve as a novel concept for designing multi-channel PEC sensing method.

A simple, scalable approach is developed to fabricate a flexible hybrid paper electrode composed of the polyaniline/graphene and the carbon fiber (CF)-reinforced bacterial cellulose. The prepared hybrid paper presents high areal capacitance of 4.145 F cm−2 at 5 mA cm−2 and an extremely low sheet resistance of 29.7 Ω sq.−1. The CF endows the paper electrode remarkable foldability with no mechanical destruction. Even after being repeatedly bent 180° up to 1000 times, the initial capacitance can be retained up to 98%. A fabricated all-solid-state supercapacitor based on the resulting paper electrode has an excellent areal capacitance of 630 mF cm−2 and energy density of 2.8 mWh cm−3. The results confirm that this approach can fabricate the highly foldable and shape-tailorable energy storage devices and may have wide potential applications.

Flexible and lightweight shielding materials recently have attracted increasing attention for terahertz wave due to the deteriorated performance of electronic equipment interferenced by electromagnetic yielding. Herein, flexible reduced graphene oxide (rGO) papers were prepared by solution evaporation method to attenuate the electromagnetic wave in terahertz field. They exhibited excellent electrical conductivity and remarkable electromagnetic interference shielding effectiveness. The electrical conductivity of the rGO papers was improved from 54.07 to 78.67 S/cm after annealing at 400 °C. The rGO paper annealed at 400 °C was only ~ 370 µm in thickness and particularly exhibited an outstanding absorption performance of 17.6 dB at 0.7 THz. It has been found that the maximum absorption performance of rGO papers was basically equivalent to that of the metamaterials. Moreover, electromagnetic interference shielding effectiveness of 72.1 dB of the rGO papers was obtained at 0.6 THz, which indicated that ~ 99.99% of the power was shielded. Thus, the flexible rGO papers maybe a promising candidate for optimized electromagnetic shielding materials in the terahertz band.

Halide perovskite quantum dots (PQDs) are promising materials for diverse applications including displays, light‐emitting diodes, and solar cells due to their intriguing properties such as tunable bandgap, high photoluminescence quantum yield, high absorbance, and narrow emission peaks. Despite the prosperous achievements over the past several years, PQDs face severe challenges in terms of stability under different circumstances. Currently, researchers have overcome part of the stability problem, making PQDs sustainable in water, oxygen, and polar solvents for long‐term use. However, halide PQDs are easily degraded under continuous irradiation, which significantly limits their potential for conventional applications. In this study, an oleic acid/oleylamine (traditional surface ligands)‐free method to fabricate perovskite quantum dot papers (PQDP) is developed by adding cellulose nanocrystals as long‐chain binding ligands that stabilize the PQD structure. As a result, the relative photoluminescence intensity of PQDP remains over ≈90% under continuous ultraviolet (UV, 16 W) irradiation for 2 months, showing negligible photodegradation. This proposed method paves the way for the fabrication of ultrastable PQDs and the future development of related applications., Solid‐state perovskite quantum dot papers are fabricated using a unique vacuum filtration growth method without a purification process. The bonding between cellulose nanocrystals and perovskite quantum dots makes the hybrid structure stable, and record high UV stability and thermal stability are achieved for perovskite quantum dot papers.

In this study, the effects of the mixing conditions of waste paper sludge ash (WPSA) on the strength and bearing capacity of controlled low-strength material (CLSM) were evaluated, and the optimal mixing conditions were used to evaluate the strength characteristics of CLSM with recyclable WPSA. The strength and bearing capacity of CLSM with WPSA were evaluated using unconfined compressive strength tests and plate bearing tests, respectively. The unconfined compressive strength test results show that the optimal mixing conditions for securing 0.8&ndash, 1.2 MPa of target strength under 5% of cement content conditions can be obtained when both WPSA and fly ash are used. This is because WPSA and fly ash, which act as binders, have a significant impact on overall strength when the cement content is low. The bearing capacity of weathered soil increased from 550 to 575 kPa over time, and CLSM with WPSA increased significantly, from 560 to 730 kPa. This means that the bearing capacity of CLSM with WPSA was 2.0% higher than that of weathered soil immediately after construction, furthermore, it was 27% higher at 60 days of age. In addition, the allowable bearing capacity of CLSM corresponding to the optimal mixing conditions was evaluated, and it was found that this value increased by 30.4% until 60 days of age. This increase rate was 6.7 times larger than that of weathered soil (4.5%). Therefore, based on the allowable bearing capacity calculation results, CLSM with WPSA was applied as a sewage pipe backfill material. It was found that CLSM with WPSA performed better as backfill and was more stable than soil immediately after construction. The results of this study confirm that CLSM with WPSA can be utilized as sewage pipe backfill material.

Foodborne pathogens are responsible for hundreds of thousands of deaths around the world each year. Rapid screening of agricultural products for these pathogens is essential to reduce and/or prevent outbreaks and pinpoint contamination sources. Unfortunately, current detection methods are laborious, expensive, time-consuming and require a central laboratory. Therefore, a rapid, sensitive, and field-deployable pathogen-detection assay is needed. We previously developed a colorimetric sandwich immunoassay utilizing immuno-magnetic separation (IMS) and chlorophenol red-β-D-galactopyranoside for Salmonella detection on a paper-based analytical device (μPAD); however, the assay required many sample preparation steps prior to the μPAD as well as laboratory equipment, which decreased user-friendliness for future end-users. As a step towards overcoming these limitations in resource-limited settings, we demonstrate a reusable 3D-printed rotational manifold that couples with disposable μPAD layers for semi-automated reagent delivery, washing, and detection in 65 minutes. After IMS to clean the sample, the manifold performs pipette-free reagent delivery and washing steps in a sequential order with controlled volumes, followed by enzymatic amplification and colorimetric detection using automated image processing to quantify color change. Salmonella was used as the target pathogen in this project and was detected with the manifold in growth media and milk with detection limits of 4.4 × 102 and 6.4 × 102 CFU mL−1 respectively. The manifold increases user friendliness and simplifies immunoassays resulting in a practical product for in-field use and commercialization.

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.

Thermal switches control thermal circuits and are widely used in electronics and engineering. Shape-memory alloys can be deformed by heating, which is widely used as a driving part for ther...

Here, we reported an ingenious fabrication of moisture responsive graphene-based actuator via unilateral two-beam laser interference (TBLI) treatment of graphene oxide (GO) papers. TBLI technique has been recognized as a representative photoreduction and patterning strategy for hierarchical structuring of GO. The GO paper can be reduced and cut into grating-like periodic reduced graphene oxide (RGO) microstructures due to laser ablation effect. However, the lower light transmittance of the thick GO paper and the corresponding thermal relaxation phenomenon make it impossible to trigger complete reduction, leading to the formation of the anisotropic GO/ reduced GO (RGO) bilayer structure. Interestingly, the RGO side that feature lower OCGs and higher roughness shows strong water adsorption due to the formation of micronanostructures. Due to the different water adsorption capacities of the two sides, a flower moisture-responsive actuator has been fabricated, which exhibits “opening” and “closing” behavior under different 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.

To improve the accuracy of color reproduction for camouflage printing, a new color matching method, named monitor-paper-fabric, was proposed by importing color management into textiles, which matched the printing pastes according to the color of the paper card printed by the ink-jet printer after color management. Not like the traditional color matching method, it matched the printing pastes according to the color from computer monitor after color correction. Two color matching methods were analyzed by comparing the color difference. It was found that the “monitor-paper-fabric” color matching method could be considered as a convenient and feasible color matching method. Most color differences between the monitor and the fabric in the camouflage pattern were reduced to lower than 4, except for color blocks 5 and 6. In addition, the color differences of six color blocks between the paper and the fabric were all less than 3.5, and were lower than those between the monitor and the fabric. The color consistency between the paper and the fabric was better than that between the monitor and the fabric.

Made available in DSpace on 2020-12-10T19:54:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-04 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) We present a capacitive smart sensor based on printed circuit board (PCB) technology to measure the amount of water content in a paper pulp at the wet end of a paper machine. The developed sensor incorporates in the same PCB the signal processing circuits. It is a handheld portable device, and its output is sent to the reading equipment using a Bluetooth wireless connection, providing to the sensor's operator ease of mobility around the wet end of a paper machine. The prototype was tested in a laboratory, using a wire mesh to emulate the end of a paper machine, and we were able to measure and easily detect when it reaches the water content in the range of 90% to 92%, as required in the paper fabrication process. Standard deviation of the capacitance measurements at various moisture levels is four orders of magnitude smaller than the mean. The smart sensor was tested in the 20 degrees C to 40 degrees C temperature range, in a paper pulp with a gravimetric water content of 91%. Since the variation of capacitance with temperature is practically linear, we propose a simple linear compensation equation to correct the observed sensitivity with the temperature. To keep the signal processing circuits small, low cost, simple, and robust, a novel direct interface sensor to microcontroller circuit technique was used to make the capacitive measurement, allowing for measuring small capacitance deviations without high-frequency oscillators. It was shown that it is possible to integrate the signal processing circuits in the top layer of the PCB interdigitated sensor without adding noise or degrading the performance of the capacitive sensor. Sao Paulo State Univ Julio de Mesquita Filho, Fac Sci & Engn, Tupa, SP, Brazil Parana Fed Univ Technol UTFPR, Cornelio Procopio, PR, Brazil FEEC UNICAMP, Dept Semicond Instrumentat & Photon, Campinas, SP, Brazil Uninove Campus Vergueiro, Sao Paulo, SP, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Fac Sci & Engn, Tupa, SP, Brazil CAPES: 001

Background Display signage is ubiquitous and essential in hospitals to serve several clerical, operational, and clinical functions, including displaying notices, providing directions, and presenting clinical information. These functions improve efficiency and patient engagement, reduce errors, and enhance the continuity of care. Over time, signage has evolved from analog approaches such as whiteboards and handwritten notices to digital displays such as liquid crystal displays, light emitting diodes, and, now, electronic ink displays. Electronic ink displays are paper-like displays that are not backlit and show content by aligning microencapsulated color beads in response to an applied electric current. Power is only required to generate content and not to retain it. These displays are very readable, with low eye strain; minimize the emission of blue light; require minimal power; and can be driven by several data sources, ranging from virtual servers to electronic health record systems. These attributes make adapting electronic ink displays to hospitals an ideal use case. Objective In this paper, we aimed to outline the use of signage and displays in hospitals with a focus on electronic ink displays. We aimed to assess the advantages and limitations of using these displays in hospitals and outline the various public-facing and patient-facing applications of electronic ink displays. Finally, we aimed to discuss the technological considerations and an implementation framework that must be followed when adopting and deploying electronic ink displays. Methods The public-facing applications of electronic ink displays include signage and way-finders, timetables for shared workspaces, and noticeboards and bulletin boards. The clinical display applications may be smaller form factors such as door signs or bedside cards. The larger, ≥40-inch form factors may be used within patient rooms or at clinical command centers as a digital whiteboard to display general information, patient and clinician information, and care plans. In all these applications, such displays could replace analog whiteboards, noticeboards, and even other digital screens. Results We are conducting pilot research projects to delineate best use cases and practices in adopting electronic ink displays in clinical settings. This will entail liaising with key stakeholders, gathering objective logistical and feasibility data, and, ultimately, quantifying and describing the effect on clinical care and patient satisfaction. Conclusions There are several use cases in a clinical setting that may lend themselves perfectly to electronic ink display use. The main considerations to be studied in this adoption are network connectivity, content management, privacy and security robustness, and detailed comparison with existing modalities. Electronic ink displays offer a superior opportunity to future-proof existing practices. There is a need for theoretical considerations and real-world testing to determine if the advantages outweigh the limitations of electronic ink displays.

This paper introduces a paper-based closed Au-bipolar electrode (BPE) biosensing system for the rapid and sensitive electrochemiluminescence (ECL) detection of miRNA-155. This microfluidic paper-based sensing platform is formed by wax-printing technology, screen printing method and in-situ Au nanoparticles (NPs) growth to form hydrophilic cells, hydrophobic boundaries, water proof electronic bridge, driving electrode regions and bipolar electrode regions. For rapid and sensitive detection, the cathode of bipolar electrode was modified with the prepared DNA (S1)–AuPd NPs by hybridization chain reaction, in which the target could initiate multiple cycles reaction to load more AuPd NPs which catalyzed H2O2 reduction. In addition, a classical ECL system tris (2,2′-bipyridine) ruthenium (II)- tripropylamine (Ru(bpy)32+/TPrA) exists at the anode of the bipolar electrode. Due to the charge balance between the anode and the cathode of BPE, the ECL signal response of Ru(bpy)32+/TPrA system was enhanced in the reporting cell. The intensity of ECL was quantitatively correlated with the concentration of miRNA-155 in the range of 1 pM–10 μM with the detection limit 0.67 pM. Moreover, this method paves a novel way for highly sensitive detection of miRNA-155 in clinical application.

Humidity sensors are indispensable for various electronic systems and instrumentations. To develop a new humidity sensing mechanism is the key for the next generation of sensor technology. In this work, a novel flexible paper-based current humidity sensor is proposed. The developed alternating current electroluminescent devices (ACEL) consist of the electroless plating Ni on filter paper and silver nanowires (AgNWs) as the bottom and upper electrodes, and ZnS:Cu as the phosphor layer, respectively. The proposed humidity sensor is based on ACEL with the paper substrate and the ZnS:Cu phosphor layer as the humidity sensing element. The moisture effect on the optical properties of ACELs has been studied firstly. Then, the processing parameters of the paper-based ACELs such as electroless plated bottom electrode and spin-coated phosphor layer as a function of the humidity-sensitive characteristics are investigated. The sensing mechanism of the proposed sensor has been elucidated based on the Q ~ V analysis. The sensor exhibits an excellent linearity ( R 2 = 0.99965 ) within the humidity range from 20% to 90% relative humidity (RH) and shows excellent flexibility. We also demonstrate its potential application in postharvest preservation where the EL light is used for preservation and the humidity can be monitored simultaneously through the current.

Flexible supercapacitors are considered as a promising candidate for power supplementation in wearable electronics due to their high power density. However, effectively fabricate flexible and low-cost supercapacitor electrodes in a big scale is still a key challenge. Herein we demonstrate a scalable fabrication method for hierarchical electrodes via metalizing air-laid paper and loading with MnO2 as cathode active materials. To be specific, we coat a thin layer of Ni on air-laid paper by magnetron sputtering, then deposit Ni nanocone arrays (NNAs) on the Ni sputtered paper and finally deposit MnO2 on the NNAs to obtain the NNAs@MnO2 paper electrode. The as-prepared paper-based electrode possesses high conductivity and fine wettability, which facilitates the electrons and ions transporting through the conductive network. Additionally, this electrode provides large specific surface area with a hierarchical architecture. Thus the electrode shows high capacitance (451 F/g) and favorable cycle performance (92.9% capacity retention after cycling for 5000 times). By coupling with activated carbon (AC) coated on the NNAs conductive paper as anode, an NNAs paper-based asymmetric supercapacitor is constructed. Benefiting from the high mechanical durability and the 3D hierarchical architecture of the electrodes, the asymmetric supercapacitor exhibits excellent mechanical flexibility and high energy density (26.9 μWh/cm2 at 1.08 mW/cm2). This method can be easily scaled up to produce lightweight and low-cost conductive paper electrodes, making it promising for the application of flexible supercapacitors in wearable electronics.

Paper-based sensors fabricated using the pencil-on-paper method are expected to find wide usage in many fields owing to their low cost and high reproducibility. Here, hydrogen (H2) detection was realized by applying palladium (Pd) nanoparticles (NPs) to electronic circuits printed on paper using a metal mask and a pencil. We confirmed that multilayered graphene was produced by the pencil, and then characterized Pd NPs were added to the pencil marks. To evaluate the gas-sensing ability of the sensor, its sensitivities and reaction rates in the presence and absence of H2 were measured. In addition, sensing tests performed over a wide range of H2 concentrations confirmed that the sensor had a detection limit as low as 1 ppm. Furthermore, the sensor reacted within approximately 50 s at all H2 concentrations tested. The recovery time of the sensor was 32 s at 1 ppm and 78 s at 1000 ppm. Sensing tests were also performed using Pd NPs of different sizes to elucidate the relationship between the sensing rate and catalyst size. The experimental results confirmed the possibility of fabricating paper-based gas sensors with a superior sensing capability and response rate.

Recently, triboelectric nanogenerator (TENG) has aroused considerable interest due to various advantages. Particularly, one benefit which sand out is that the triboelectric pair of TENG is very tolerant to the material composition. Thus, it is possible and significant to develop cost-effective TENG using commercial and inexpensive material. In this work, we present a paper TENG by repeated folding completely using commercially available commodity materials, such as paper, brush pen, Teflon tape, and conductive ink. Paper is used as functionally triboelectric pair and spring-like supporting structure. The stacked paper TENG is fabricated and large enhancement of output performance is observed. The generated electric outputs have been used to directly light-up commercial LEDs. The proposed TENG has demonstrated simplicity and cost-effective, which is suitable for flexible electronics.

In the last decade, much effort has been invested in using methanol as an oil-soluble chemical marker for assessing the condition of insulating paper. The use of this marker as paper life index presents many advantages particularly with new transformers insulated with thermally upgraded papers. However, until now, no interpretation model has been available for its extensive use by the transformer community. In this paper, a methanol-based interpretation model is presented for the first time using postmortem paper analysis on core-type transformers. This model allows the evaluation of the average degree of polymerization of a transformer's cellulose winding. Furthermore, threshold values based on the methanol concentration are given using this approach. Finally, model validation was performed on a limited number of papers taken from transformers being assessed in the repair shop.

The purpose of this study is to investigate influence of calcination and cooling conditions on pozzolanic reactivity of waste paper sludge. Calcined paper sludge (CPS) is prepared by different temperatures of calcination, duration of calcination and cooling methods. Pozzolanic activity of CPS was investigated by using API (Assessed Pozzolanic Activity Index) and SAI (Strength Activity Index) in accordance with ASTM C618 -17 (KS L 5405) and consumption of Ca(OH)2 hydrate in mortars with CPS in detail, and compared to that of commercial fly ash (FA) and blast furnace slag (BFS) used in the concrete industry. Results revealed CPS produced from waste paper sludge had excellent pozzolanic activity compared with commercial pozzolanic admixtures such as FA or BFS. Their pozzolanic activity was most excellent in calcination temperature of 700 °C, calcination duration of 2 h and cooling method of water quenching. SAI (%) of mortar with CPS produced under optimal conditions was 96% at 28 days of age, and satisfied the quality of fly ash (Class F) as specified in ASTM C618 -17 (KS L 5405). There was linear relation between API (%) and SAI (%) of mortars with CPS, and the correlation coefficient was relatively good as 0.8 at 28 days of age. The API method is recommended as rapid and appropriate evaluation of the pozzolanic activity of the CPS.

When portability, low cost, and green energy requirements are considered, the search for an electricity generator harvesting environmental energy based on available cheap commercial materials and simple fabrication techniques becomes significantly important. In this study, the capability of ultrasoft and cuttable paper-based triboelectric nanogenerator (P-TENG) to harvest mechanical energy is demonstrated. The P-TENG maintains the excellent softness of tissue paper and has the characteristics of light weight (~ 87 g/m2), high electric conductivity (6 Ω/square), and low cost (~ $3.00/m2). More importantly, the P-TENG can be cut by the end-user to modify its size and shape and still function properly. The mechanical energies available during cleaning processes, the energy associated with the body's motion, sound energy, and wind energy can be directly harvested by using the P-TENG. The high portability of the P-TENG, the simple and scalable fabrication processes, low cost, and its ability to harvest mechanical energy make the P-TENG important for the development of green, portable, energy-harvesting devices.

This work demonstrates the solution processed fabrication of a SnS2/graphene (Gr) heterojunction on a biodegradable cellulose paper substrate for its utilization as a broadband photodetector. Graphene was dip coated on cellulose paper followed by the direct growth of SnS2 on Gr/cellulose paper by a hydrothermal method. To study the charge transport mechanism of this unique heterojunction, first principles calculations are performed to theoretically estimate the band gap and the electron affinity values that lead to a detailed understanding of the band alignment in this heterojunction. There are no reports which demonstrate the direct large area growth of SnS2 on cellulose paper to fabricate an efficient broadband photodetector, complemented by a detailed theoretical understanding to understand the underlying physics of this device. The responsivity of the fabricated photodetector was calculated to be 6.98 and 3.67 mA W−1 for visible and UV light illumination respectively suggesting that the device was more responsive towards the visible spectrum when compared to the UV region. The durability of the photodetector was tested by subjecting it to 500 bending cycles wherein a negligible change in the responsivity values was observed. The successful fabrication of a large area SnS2/Gr heterojunction on a low-cost cellulose paper substrate with its performance metrics comparable to a device fabricated using sophisticated techniques is a major step ahead in the development of low-cost photodetectors which finds potential applications in security, visible light communication, etc.

The objective of this study was to determine the effect of electrical conductivity, pH and temperature which were kept constant during treatment via an advanced control strategy on chemical oxygen demand, color, turbidity and total suspended solids removal and energy consumption. Central Composite Design matrices were formed for aluminum and iron electrode systems separately with different combinations of 5 independent variables (electrical conductivity, pH, temperature, current intensity and electrolysis time). Obtained results revealed that aluminum electrode system was found to be more effective than iron electrode system under controlled conditions. Comparison of uncontrolled and controlled studies at optimum values of aluminum electrode system showed an increase by 31.67% in chemical oxygen demand removal and a decrease by 48.30% in energy consumption under controlled case. Results indicated that constant electrical conductivity, pH and temperature during electrocoagulation process of pulp and paper mill wastewater by means of a controller enhanced treatment efficiency.

Large-sized graphene sheets (LG) and doping strategy were employed to fabricate lightweight and flexible graphene paper with exceptional electromagnetic interference (EMI) shielding performance. Compared with the smaller sized ones, LG with fewer defects and more conjugated carbon domain size as well as better alignment result in higher electrical conductivity and strength of graphene paper. The iodine doping further improves the carrier density of LG by formation of triiodide ( I 3 − ) and pentaiodide ( I 5 − ) through charge transfer process without deteriorating the mechanical property, thus leading to superior EMI shielding effectiveness (SE). The EMI SE of iodine doped LG film with thickness of 12.5 μm is up to ∼52.2 dB at 8.2 GHz, which is much higher than that of undoped LG with the same thickness (∼47.0 dB). More important, the improvements in EMI SE is contributed to the SE absorption, while the SE reflection is almost unchanged. The mechanisms of improved EMI shielding performance as well as mechanical property were investigated and discussed. The present study provides a facile way to fully develop graphene in lightweight and flexible EMI shielding materials and devices.

Frequency Domain Spectroscopy (FDS) is proposed as a suitable diagnostic method in this paper for implementation on energized oil-paper insulation systems. In present FDS tests, the measurement method is only designed for offline applications. To overcome the deficiencies with the offline testing, this work investigates the feasibility of performing FDS measurements on energized transformers with the view to developing an online diagnostic tool using neutral connections as injection and measurement paths. In the proposed technique, a low-pass filter system is designed to remove the high frequency noise as well as the power frequency signals present in the measured neutral currents. The technique has been successfully applied in a laboratory environment on transformers with oil-paper insulation systems with different operational ages and is feasible for single-phase as well as 3-phase transformers with the accessible neutral points. Compared with the conventional FDS results, a nonlinear dielectric phenomenon is observed from the energized insulation systems as higher dissipation factor Tanδ values primarily due to the increased losses under power frequency voltage excitation. The degree of the nonlinearity is found to correlate well with the degradation status of insulation systems under test.

The state-of-art is a mesophilic treatment of wastewater in paper mills without reuse due to the high water quality requirements. Thermophilic biological treatment could save a large amount of thermal energy, but the major obstacle of a reuse are the poor sludge settling properties under thermophile conditions, leading to insufficient water quality if conventional gravimetric phase separation is applied. MBR technology is a promising alternative which allows a recirculation of treated water for improving the water and energy footprint. So far, there is only limited experience with thermophilic MBR at the time. In this study, a thermophilic MBR with a submerged membrane (TSMBR) was operated to treat wastewater from a paper mill with a COD concentration of 25–30 g L −1 . The TSMBR was integrated into the operational process of the paper mill. Research questions were the influence of suspended solids, food to microorganism ratio (F/M ratio), cross-flow-aeration and filtration flux to the fouling of the membrane. Applying the critical flux concept, optimal operating conditions and costs for a future economic full-scale implementation could be derived. Key results are inter alia a sub-critical flux of below 10 L m −2 h −1 is recommended for long-time durability of the membrane for minimizing the irreversible fouling and the permeability decrease. A chemical cleaning does not change the critical flux, but improves the permeability of the membrane significantly. The TSMBR suffered from increasing fouling at a cross-flow-aeration of below 0.6 m 3 m −2 h −1 and a concentration of suspended solids of above 14 g L −1 . A stable process and cleaning could only be ensured by a F/M ratio of below 0.4 g COD g MLSS −1 d −1 . Higher values result in an increased cake layer formation and intensive foaming.

Made available in DSpace on 2019-10-04T12:39:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-07-15 Japan Society for the Promotion of Science, Japan JSPS KAKENHI Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) This article presents results of a pulsed UV laser method for the simultaneous reduction of graphite oxide (GO) and patterning of reduced graphene oxide (rGO). This direct laser writing method was applied to the fabrication of graphene-based, in-plane interdigitated micro-supercapacitors (mu-SCs), prepared on free-standing GO paper (10 mu m thick). The electrochemical performance of mu-SCs was studied using two different electrolytes (KOH and NaCl). The results from cyclic voltammetry measurements exhibited typical electrical double layer behavior, with specific capacitances of 9.3 mu F/cm(2) and 13.8 mu F/cm(2) (at a scan rate of 10 mV/s) for KOH and NaCl electrolytes, respectively. The mu-SCs exhibited good performance, with retention of 95% of the original capacitance values after 3400 charge-discharge cycles. When compared to devices obtained by conventional lithographic techniques, the laser fabrication of planar mu-SCs is faster, cost-effective and scalable. We believe this one-step and environmentally friendly laser-assisted method to be a good alternative for the fabrication of flexible energy storage devices. (C) 2019 Elsevier Ltd. All rights reserved. Toyohashi Univ Technol, Dept Elect & Elect Informat Engn, 1-1 Hibarigaoka,Tempaku Cho, Toyohashi, Aichi 4418580, Japan Ctr Informat Technol Renato Archer CTI, BR-13069901 Campinas, SP, Brazil Univ Campinas UNICAMP, Ctr Semicond Components & Nanotechnol CCS Nano, BR-13083870 Campinas, SP, Brazil Sao Paulo State Univ, Dept Phys, Fac Sci & Technol, BR-19060900 Presidente Prudente, SP, Brazil CUHP, Sch Phys & Mat Sci, Dharamshala 176215, HP, India Univ Campinas UNICAMP, Inst Chem, Dept Analyt Chem, POB 6154, BR-13084974 Campinas, SP, Brazil Sao Paulo State Univ, Dept Phys, Fac Sci & Technol, BR-19060900 Presidente Prudente, SP, Brazil Japan Society for the Promotion of Science, Japan: P18063 JSPS KAKENHI: 18H03841 JSPS KAKENHI: 18F18063 FAPESP: 2017/22186-0 FAPESP: 2013/14262-7

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.

Herein, Microfluidic Paper-based Analytical Devices (μPAD) strips, also called microstrips, have been fabricated using a fused-deposition modeling (FDM) based 3D printer. A polycaprolactone (PCL) filament on a chromatography paper was harnessed to create hydrophobic boundaries of a microchannel. A pair of screen-printed electrodes, with known separation, were integrated on the microchannel to measure the time taken for fluid automatically. A mini electronic sub-system, amenable to connect with an android smartphone, consists of an easily programmable microcontroller, Bluetooth module and voltage booster circuit. The pluggable-and-playable disposable microstrip was utilized to measure the viscosity of various biological samples with an accuracy of92% with respect to a benchtop viscometer. In particular, the protein denaturation of Bovine Serum Albumin (BSA) and Lysozyme, and viscosity variation of human saliva have been observed. With a competency to measure the viscosity between 0.5 cP to 10 cP, platform cost ofUS$ 8 and a cost-per-test of less than US$ 0.02, the present device has a strong potential to be employed as a personalized gadget for various viscosity dependent measurements.

This paper presents a critical review of laser pyrolysis. Although this technology is almost 60 years old, in literature many researchers, both from academia and industry, are still developing and improving it. On the contrary industrial applications are struggling to take off, if not in very restricted areas, although the technology has undoubted advantages that justify future development. The aim of this work consists in analysing a representative pool of scientific papers (230) and patents (121), from the last 20 years, to have an overview about the evolution of the method and try to understand the efforts spent to improve this technology effectively in academia and in industry. This study is important to provide a complete review about the argument, still missing in the literature. The objective is to provide an overview sufficiently broad and representative in the sources and to capture all the main ways in which laser pyrolysis has been used and with what distribution. The main focuses of the study are the analyses of the functions carried out by laser technologies, the application fields, and the types of used laser (i.e. models, power and fluence). Among the main results, the study showed that the main use of laser pyrolysis is to produce nanoparticles and coatings, the main materials worked by laser pyrolysis are silicon and carbon dioxide and the main searched properties in the products of laser pyrolysis are catalysts activity and electrical conductivity. CO2 lasers are the most used and the have high versatility compared to others. In conclusion, the study showed that laser pyrolysis is a consolidated technology within its main application fields (nanoparticles and coatings) for several years. Within this context, the technology has been developed on very different sizes and processes, obtaining a very wide range of results. Finally, these results may also have stimulated new areas of experimentation that emerged mainly in recent years and which concern biomedical applications, additive manufacturing, and waste disposal. Graphical abstract

Managing a large fleet of ageing assets has become a technical challenge faced by many electricity utilities in developed countries. Asset managers are increasingly interested in techniques that can help extend the useful lifetime of a transformer. Oil regeneration is one of such techniques. In this paper, oil regeneration experiments were performed on a 6.4/0.4 kV retired distribution transformer to investigate the effect of oil regeneration on improving paper conditions. Oil regeneration was conducted in two stages, with the first stage aimed at ‘cleaning the oil’ and the second stage targeted at ‘cleaning the paper’. Oil samples were collected at regular intervals throughout the process and paper samples were obtained from the transformer before and after each oil regeneration stage. It was found that oil regeneration restores oil parameters, including moisture and acidity, similar to those of new oils at the end of stage 1. Analysis of paper samples indicated a reduction in paper moisture at the end of stage 2 by nearly 40%, while low molecular weight acids (LMA) in paper exhibited a reduction by around 30% on average. It is found that the extended oil regeneration period, i.e., stage 2, is necessary to improve the paper condition and hence to reduce the paper ageing rate.