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Made available in DSpace on 2022-04-29T08:36:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-01 Paper electronics has emerged as an ecofriendly, light, low-cost, and recyclable material for the fabrication of flexible and printed transistors. In this study, we present fully printed organic electrochemical transistors using an active layer of PEDOT:PSS, carbon electrodes, cellulose-based electrolyte, and three different papers as substrates: bond, vegetal, and Lumi Silk, relating the electrical properties to the different morphologies of the paper surfaces. Each paper presents different regularity, diffusion capabilities, and roughness, with significant influence on the transistor performance. The more organized and smooth the surface, the better the electrical characteristics, the best of these being the Lumi Silk, with higher I on/I off ratio of 46, on-current of 8.3 10-5 A, V on of 1.3 V, and power gain of 43.5 dB associated with ultra-low hysteresis of 0.1 V, high transconductance of -57.3 μS, and suitablity for flexible electronics and sensors applications. S o Paulo State University - UNESP Faculty of Science and Technology (FCT) Physics Department, SP Universidade NOVA de Lisboa and CEMOP-UNINOVA Faculty of Science and Technology (FCT) CENIMAT/I3N Department of Materials Science S o Paulo State University - UNESP Faculty of Science and Technology (FCT) Physics Department, SP

Light-reflecting characteristics play a crucial role in optically rewritable liquid crystal display (electronic paper). By using a special optimizer software, light-reflecting characteristics of the twisted nematic cell were calculated. The achieved values of the normalized reflection coefficients range within ∼ 0.03 - 0.43, which is comparable or better than other commercial technologies. The calculated contrast ratio of the device is 10 : 1. A 2D image, which can be displayed on the electronic paper was obtained. Comparison of the simulated background color and contrast ratio is very similar with the results, which were obtained in experimental cells of other studies. Our calculations indicate that angular dependence of the reflectance coefficient is almost uniform within a wide range of viewing angles.

This paper presents the integration process of an ultra-thin PZT/Si chip on paper and that it functions as a simple speaker by applying a voltage in the audible frequency range. The PZT/Si chip used is only 5-μm-thick, so it does not interfere with the flexibility of the substrate, and it can be integrated on paper because it does not use a high-temperature process in the electrode connection process. We have revealed that a paper with an ultra-thin PZT/Si chip of only 1 × 5 mm2 in size generates a fully audible sound pressure level (SPL) of about 40 dB. It was rounded to a radius of curvature of 1 cm without breaking. The overall SPL was about the same even when the paper substrate dimension was reduced to 50 mm square. This technology is expected to be applied to electronic components such as surround speakers or haptics in electronic paper.

With the utilization of used newspaper into the paper making industry, bleaching has been an area of concern to obtain a balance between desired brightness and the amount of treatment it requires. Motivation of this study was to optimize bleaching of recycled newsprint fibers in terms of five variables namely hydrogen peroxide charge, amount of sodium hydroxide employed, pulp consistency, bleaching temperature, and bleaching time. Experimental work was conducted in the laboratory to simulate bleaching plant and it was found that higher peroxide charge is better for improvement in brightness, but it is uneconomical to increase peroxide charge indefinitely. The amount of hydrogen peroxide is added so that the residual peroxide at the end of the reaction is not less than 10% of the initially added peroxide. Sodium hydroxide provides alkalinity which is very important for making the fibers flexible and softening of ink particles but it also contributes to pulp yellowing if residual hydrogen peroxide contents are lesser than the minimum required value. So, for 16 kg t−1 of hydrogen peroxide, 6 kg t−1 of sodium hydroxide prevented the brightness reversion in this study. Higher pulp consistency is better but unavailability of very high consistency pulp mixer in the industry is a limiting factor for higher than 30% pulp consistency. Temperature and time are quite interrelated and, with the given bleaching conditions, a temperature of 95 °C with 10 min residence time was found to be optimum for this study. It was also observed that multiple pre-washings increase brightness and save bleaching chemicals.

Recent Industry looking for paper battery with highly flexibility, easily handling and high voltage. Currently, battery occupies a large quantity of vicinity and contributes to a big part of device weight. In this paper, we use carbon nanotubes with conventional sheet of cellulose based paper as cathode, aluminum foil as anode and a polyethylene (plastic paper) of 50µm as a separator to obtain adaptability, ultra-thin electricity storage without a loss of integrity and performance. In this attempt folded anode and cathode sheets which resulted increase in voltage and achieved approximately 40% more than other paper batteries. Voltage 3.38V is achieved which is better than the preceding existing paper battery voltage.

We have proposed and fabricated resistive-type flexible pressure sensors composed of multi-walled carbon nanotube thin films, liquid metal droplets, sponge rubber, and paper. The pressure sensor detects external pressure in the range of tens of kilopascals. The resistance change was found to be approximately 70% when a pressure of 100 kPa was applied. The sensor operation showed good reproducibility under cyclic applied pressure. The simple sensor structure and environment-friendly materials allow the sensor to be easily disassembled into its components, which are reusable and combustible.

The insulation state of the converter transformer is closely related to the properties of the oil-paper insulation material. The study of the partial discharge characteristics of the wrinkled of the insulation paper has practical engineering significance for the fault diagnosis of the converter transformer. According to the actual operating environment inside the converter transformer, a set of oil-paper-insulated partial discharge measurement platform under the action of AC and DC composite voltage was built. The test results show that insulation paper wrinkles under the action of AC/DC composite voltage will cause insulation damage due to higher surface electric field and partial discharge; the discharge pulse repetition rate and discharge volume increase in the initial stage, development stage and final dangerous stage of discharge. The partial discharge caused by paper wrinkled significantly increases the CH4 content in the dissolved gas in the oil. This conclusion provides a certain basis for the realization of converter transformer fault diagnosis and condition monitoring.

The partial discharge in lower porcelain shell of oil paper insulation bushing is one of the important reasons for transformer failures. Based on the analysis of the oil paper insulation bushing structure characteristics, the finite difference time domain simulation model of the partial discharge in lower porcelain shell is established. And the path of UHF signal of partial discharge is obtained that the signal spreads through the insulation between capacitor screens and oil passage to the outer space. Then the lower porcelain shell partial discharge detection method based on the space UHF signal is proposed and verified.

Two-step activation of paper batteries has been successfully demonstrated to provide quick activation and to supply high power to credit card-sized biosystems on a plastic chip. A stack of a magnesium layer (an anode), a fluid guide (absorbent paper), a highly doped filter paper with copper chloride (a cathode) and a copper layer as a current collector is laminated between two transparent plastic films into a high power biofluid- and water-activated battery. The battery is activated by two-step activation: (1) after placing a drop of biofluid/water-based solution on the fluid inlet, the surface tension first drives the fluid to soak the fluid guide; (2) the fluid in the fluid guide then penetrates into the heavily doped filter paper with copper chloride to start the battery reaction. The fabricated half credit card-sized battery was activated by saliva, urine and tap water and delivered a maximum voltage of 1.56 V within 10 s after activation and a maximum power of 15.6 mW. When 10 k? and 1 K? loads are used, the service time with water, urine and saliva is measured as more than 2 h. An in-series battery of 3 V has been successfully tested to power two LEDs (light emitting diodes) and an electric driving circuit. As such, this high power paper battery could be integrated with on-demand credit card-sized biosystems such as healthcare test kits, biochips, lab-on-a-chip, DNA chips, protein chips or even test chips for water quality checking or chemical checking.

The research aimed to produce natural wrapping paper from banana (Musa Paradisiaca Linn.) peel waste with additive essentials oils. The method used in this research was alkalization. The delignification process is done with the use of NaOH 4% at the temperature of 100°C for 1.5 hours. Additive materials in the form of essential oils are added as a preservative and aroma agent, namely cinnamon oil, lemon oil, clove oil and lime oil respectively 2% and 3%. Chemical and physical properties of the produced papers are tested included water content (dry-oven method SNI ISO 287:2010), pH (SNI ISO 6588-1.2010), grammage (SNI ISO 536:2010) and brightness (SNI ISO 2470:2010). Testing results of each paper were compared with commercial wrapping paper. The result shows that the natural paper from banana peel waste with additive essential oil meets the standard of ISO 6519:2016 about Basic Paper for Laminated Plastic Wrapping Paper within the parameter of pH and water content. The paper produced also meet the standard of ISO 8218:2015 about Food Paper and Cardboard within the grammage parameter (high-grade grammage), except the paper with 2% lemon oil. The paper which is closest to the characteristic of commercial wrapping paper is the paper with the additive of 2% cinnamon oil, with pH of 6.95, the water content of 7.14%, grammage of 347.6 gram/m2 and the brightness level of 24.68%.

Owing to their very high thermal conductivity as well as large surface-to-volume ratio, graphene-based films/papers have been proposed as promising candidates of lightweight thermal interface materials and lateral heat spreaders. In this work, we study the cross-plane (c-axis) thermal conductivity (k c ) and diffusivity (α c ) of two typical graphene-based papers, which are partially reduced graphene paper (PRGP) and graphene oxide paper (GOP), and compare their thermal properties with highly-reduced graphene paper and graphite. The determined α c of PRGP varies from (1.02 ± 0.09) × 10−7 m2 s−1 at 295 K to (2.31 ± 0.18) × 10−7 m2 s−1 at 12 K. This low α c is mainly attributed to the strong phonon scattering at the grain boundaries and defect centers due to the small grain sizes and high-level defects. For GOP, α c varies from (1.52 ± 0.05) × 10−7 m2 s−1 at 295 K to (2.28 ± 0.08) × 10−7 m2 s−1 at 12.5 K. The cross-plane thermal transport of GOP is attributed to the high density of functional groups between carbon layers which provide weak thermal transport tunnels across the layers in the absence of direct energy coupling among layers. This work sheds light on the understanding and optimizing of nanostructure of graphene-based paper-like materials for desired thermal performance.

In this study, a novel paper biosensor based on Fe3O4@SiO2–NH2 magnetic polymer microspheres and multi walled carbon nanotubes (MWCNTs) for rapid detection of pseudorabies virus (PRV) was first developed. Fe3O4@SiO2–NH2 were functionalized with PRV antibody and doped in cellulose nitrate paper to fabricate the magnetic paper biosensor with good magnetic response and biocompatibility. Using MWCNTs to build conductive network of sensors, PRV antigen binds specifically to the immunomagnetic microspheres on the sensor, and the resulting immune complex changes the magnetic domain structure of the sensor and the structural gap of MWCNTs, causing the magnetic property and impedance change. TEM and EDS characterization proved that the biosensor was successfully doped with Fe3O4@SiO2–NH2 and effectively recognized PRV. Under optimized conditions, the impedance variation was found to be linearly related to the logarithm value of PRV concentrations in the range of 10–1 mg ml−1, with the detection limit of 10 ng ml−1. This paper biosensor demonstrated advantages of portability, high sensitivity and specificity, providing a valuable method for early control of PRV.

The new principle of electronic paper that can display two-dimensional (2D) or even stereoscopic three-dimensional (3D) images was developed by us. We review the structure of the display unit that is the light printable rewritable matter with polarization dependent gray scale. It consists of one or two liquid crystal displays based on optical rewritable (ORW) technology. ORW display uses bare plastic or polarizers as substrates, while no conductor is required. Continuous grey image on ORW e-paper maintains proper performance even when the device is bent. The image is changed by light printer. We discuss and experimentally verify the possible design of the light printer device based on polarization rotation. Alternative designs based on twist nematic (TN) or ferroelectric liquid crystals (FLC) operational element are also suggested. Simple construction provides durability and low cost of the ORW e-paper concept, while amazing possibility of 3D picture on ORW electronic paper is principally proved.

The first urine-activated laminated paper batteries have been demonstrated and reported in this paper. A simple and cheap fabrication process for the paper batteries has been developed which is compatible with the existing plastic laminating technologies or plastic molding technologies. In this battery, a magnesium (Mg) layer and copper chloride (CuCl) in the filter paper are used as the anode and the cathode, respectively. A stack consisting of a Mg layer, CuCl-doped filter paper and a copper (Cu) layer sandwiched between two plastic layers is laminated into the paper batteries by passing through the heating roller at 120 °C. The paper battery is tested and it can deliver a power greater than 1.5 mW. In addition, these urine-activated laminated paper batteries could be integrated with bioMEMS devices such as home-based health test kits providing a power source for the electronic circuit.

We developed new teaching materials, electrical resistors and capacitors, using carbon nanotube (CNT) paper and carbon fibre (CF) paper to foster students’ creative thinking, thereby deepening and extending learning. Using a CNT-paper electrical resistor, it is possible to elucidate the dependence of the resistance value on the length and width. The resistance value is proportional to the length and inversely proportional to the width of the paper. In the case of the CF-paper capacitor, it is also possible to clarify the dependence of the capacitance value on the area and the distance between papers. The capacitance value is proportional to the areas of the papers and inversely proportional to the distance between them. Based on the results of our experiments using the new teaching materials, we confirmed that the measured values were in good agreement with the values predicted by theoretical calculations. Using these materials, it becomes possible for students to visually and actively learn about electrical resistance and capacitance through experiments by themselves and in discussion with other students, in contrast to the traditional teaching methods practiced in many schools worldwide. We found that teaching methods using these materials are a useful and easy way to teach the basic concepts of resistance and capacitance with geometric factors in classrooms.

Electron grid therapy is expected to be a valid treatment for bulky superficial tumors. It is difficult, however, to fit irradiation fields to bulky superficial tumor shapes for conventional electron grid therapy with a cerrobend grid collimator. In this study, we investigated whether a grid collimator using tungsten functional paper (TFP), with its radiation shielding ability, could be used for electron grid therapy. Dose distributions were measured using 9 MeV electron grid beams from a cerrobend grid collimator. For the simulation study, the same grid irradiation fields were shaped using a TFP grid collimator (thicknesses of 0.15, 0.3, 0.6, 0.9, and 1.2 cm) by laying them on a phantom. We then determined the dose distributions using Monte Carlo calculations and compared the cerrobend and TFP electron grid beams regarding dose distributions, including the depths of the maximum dose (d max), 90% dose (d 90), and 80% dose (d 80), and the ratios of the doses in the areas with and without shielding (valley to peak ratios). The equivalent dosimetric thickness was obtained with the TFP grid collimator that was equivalent to the dose distribution of the cerrobend grid collimator. For the cerrobend electron grid beams, the d max, d 90, and d 80 were 1.0, 2.1, and 2.5 cm, respectively, and the valley to peak ratios at those depths were 0.48, 0.66, and 0.73, respectively. The equivalent dosimetric thickness of TFP was 0.52 cm. The d max, d 90, and d 80 for the 0.52 cm thick TFP electron grid beams were 1.1, 1.9, and 2.3 cm, respectively, and the valley to peak ratios at those depths were 0.49, 0.63, and 0.71, respectively. The TFP grid collimator flexibly delivered excellent dose distributions by simply attaching it to the patient's skin. It could thus be used for electron grid therapy instead of the cerrobend grid collimator.

This paper presents the study of breakdown characteristic of Kraft paper insulated with two different types of insulating fluid, which are Palm oil and Coconut oil. Palm oil and Coconut oil are chosen as the alternative fluid to the transformer oil because it has high potential and environmentally-friendly. The Segezha Kraft papers with various thicknesses (65.5 gsm, 75 gsm, 85gsm, 90 gsm) have been used in this research. High Voltage Direct Current (HVDC), High Voltage Alternating Current (HVAC) and carbon track and severity analysis is conducted to observe the sample of aging Kraft paper. These samples have been immersed using Palm oil and Coconut oil up to 90 days to observe the absorption rate. All samples started to reach saturation level at 70 days of immersion. HVDC and HVAC breakdown experiments have been done after the samples had reached the saturation level based on normal condition, immersed in Palm oil and immersed in Coconut oil. All samples immersed in liquid show different breakdown voltage reading compared to normal condition. The analysis of carbon track and severity on surface has been done using Analytical Scanning Electron Microscope (SEM) Analysis. The results of the experiment show that the sample of Kraft paper immersed in Palm oil was better than Coconut oil immersed sample. Therefore the sample condition was the main factor that determines the value of breakdown voltage test. Introduction

We report the preparation, reduction and characterization of GO paper that obtained by assembly of individual GO sheets. The free standing GO paper was prepared from 4 mg/ml GO dispersed in water, and following by evaporation of water and then detach from the petri dish. In order to obtained graphene-like film, the free-standing GO film then thermally reduced by heating the samples at 250°C at varied heating time. Characteristic and properties of the thermally reduced GO paper was measured by means of infrared spectroscopy, X-ray diffraction and EDS.

Femtosecond laser ablation of freestanding reduced graphene oxide (rGO) paper and its mechanisms were investigated. An abnormal phenomenon was discovered: the ablated area remained unchanged for the rGO paper with an increasing number of pulses, which was found to be a general feature for a large range of laser fluences. We also studied femtosecond laser ablation of graphene oxide paper and highly oriented pyrolytic graphite film for comparison. Experimental results indicated that the abnormal phenomenon was unique to the rGO paper. As revealed by a combination of SEM, TEM, XRD and Raman techniques, femtosecond laser nonthermal ablation through rolling up of rGO nanoflakes, induced by the distinctive multi-level layer-by-layer structures and the ultrafast energy relaxation of the rGO paper, were considered to be responsible for the non-incubation effect.

In this study, a paper-gate transistor was developed to detect glucose using an extended-gate field-effect transistor (FET). A filter paper was used as an extended gate electrode, in which Au nanoparticles (AuNPs) modified with phenylboronic acids (PBAs) were included. PBA–AuNPs play an important role as a support to not only be entrapped in cellulose fibrils but also bind to the targeted glucose in a paper. The surface properties of PBA–AuNPs were investigated to elucidate the electrical properties of the paper-gate electrode using an absorption spectrum and a zeta potential analysis. Moreover, the paper-gate electrode enabled us to detect glucose at the micromolar level on the basis of the principle of FET devices. A platform based on the paper-gate transistor is suitable for a highly sensitive system to detect glucose in trace samples such as tears, sweat, and saliva in the future.

Two carbon fibers were first fabricated by one-step pyrolysis of papers (filter paper and facial tissue), and then employed as catalytic materials for counter electrodes in dye-sensitized solar cells (DSCs) to investigate their potential application. The results show that the microstructure transformation and main weight loss of both the papers are mainly happened in the temperature range of 300–400 °C. After pyrolysis at 800°C, the weight remaining of the filter paper and facial tissue is 1.92% and 4.95%, respectively. The obtained carbon fibers belong to an amorphous carbon consisting of the randomly oriented stacks of graphene sheets. The diameters of both the carbon fibers are about 10 μm, on which there are a certain amount of fine carbon nanofibers. The amorphous microstructure and unique fine nanofibers of the carbon fibers induce more excellent catalytic activity for triiodide ion reduction compared with the biochar (derived from poplar leaf) and the graphite. As a result, the carbon fiber based DSCs display obviously higher efficiency than the biochar or graphite based ones. The conversion efficiency of the DSCs employing the filter paper derived carbon fiber, facial tissue derived carbon fiber, biochar and graphite is 4.72%, 4.70%, 1.33% and 0.77%, respectively.

A novel display mode called the mobile fine particle display (MFPD) is proposed. Fine particles doped and dispersed in nematic liquid crystals are used in our MFPD cell. The distribution of fine particles on a plane parallel to the substrate surface can be controlled by changing applied electric field, which is a DC field or an AC field adjusted by applying DC, to obtain optical changes in the MFPD cell. The velocity of fine particles is dependent on the electric force, dielectric force and friction force acting on the particles, and the flow of liquid crystals. The MFPD shows excellent characteristics such as a high reflectivity (approximately 50%), a high contrast ratio (more than 10), and a wide viewing angle. In addition, images displayed on the MFPD can be rewritten by the application of an electric field and be sustained under a no-voltage-application condition for a long time (over 5–7 months). The characteristics of the MFPD indicate that this new type of display is suitable for electronic paper displays.

Electrostatic discharge, as a common natural phenomenon in daily life, seriously threatens the reliability of integrated circuit products. In order to ensure the yield of the chip, the protection circuit on the chip has become an essential and important module in the circuit design. With the continuous development of integrated circuit technology, chips are developing towards the direction of smaller area, faster speed and higher level of integration, while traditional devices such as simple diodes, tubes and SCR on integrated circuit can no longer complete the protection task of chips under advanced technology. Through the research and discussion of this paper, the methods and strategies of electrostatic discharge protection design of integrated circuits and how to choose the best electrostatic discharge protection scheme for different integrated circuits are basically mastered.

One of the challenges of printing and paper industries is the issue of inappropriate humidity in the environment where the paper mills and printing shops or stores are located. Humidity of the environment is a factor of great concern for storage of papers and when printing. This work considers the needed optimum relative humidity that is required for high quality printing and analysis of a fifteen-year weather data of hourly dry bulb temperature (TDB) and relative humidity (RH) for Abuja in the Federal Capital Territory of Nigeria, obtained from the Nigerian Meteorological Agency (NiMet). A bin width of 1°C and 5% were used for TDB and RH respectively. The two-dimensional dry bulb temperature and relative humidity bin data were obtained for each month of the year. High relative humidity which is inimical to high quality printing production, occurs in many months of the year, especially June through October, hence dehumidification process would be desirable during such periods. The optimum relative humidity for quality printing of between 45%-55% occurred for about 1027.9 hours out of the 8766 hours in the year. Therefore, it can be concluded that dehumidification to the right humidity level is necessary most of the time in Abuja for good quality printing work.

Flexible inkjet-printed antenna models are designed on paper and transparent polyethylene terephthalate substrate material for vehicular instrument communication applications. The antenna model 1 is designed initially on a low-cost photo paper substrate material and later model 2 is designed on flexible PET substrate for vehicular instrument communication with dimensions of 40×38.5×0.2 mm3. The proposed antenna model on PET substrate is providing the excellent bandwidth of 7.6 GHz with impedance bandwidth of 78%. The proposed antenna is designed to operate in vehicular communication bands, which includes the cellular communication bands, V2X communication bands and other wireless applications like Universal Mobile Telecommunications System (UMTS), Long-Term Evolution (LTE2600), Wireless local area network 2.4 GHz (WLAN), World Interoperability for Microwave Access (WiMAX), IEEE802.11p protocol based Vehicle-to-everything 5.8 GHz, Dedicated short-range communications (DSRC) and Wireless Access in Vehicular Environments 5GHz (WAVE) communications bands. The prototyped models are fabricated and tested for validation and found perfect matching with the simulation results with respect to reflection coefficient, radiation patterns and gain. The achieved results based on the proposed techniques can be extended for other flexible substrates to design complex advanced antennas and communication modules.

The cell-free DNA in gingival crevicular fluid (GCF) is a recent interesting diagnostic marker in patients with periodontal disease. The methods used to collect GCF are very important to get the proper specimen. There are several techniques used for sample collection, such as gingival washing or using a capillary tube, however, these methods are not practical to perform in the clinic since they need well-trained examiner. This study aimed to use absorbent paper strips to collect cell-free DNA fragment in GCF of patients as a diagnostic measure for periodontal diseases comparing to conventional washing technique. Thirty-nine periodontitis and 26 gingivitis teeth were selected from 26 patients according to clinical parameters. The GCF sample was randomly collected from each tooth by either paper strips or washing technique. Then, after one week, the collection of samples from the same tooth was repeated with another technique. The samples were centrifuged to get cell-free DNA in the supernatant and extracted by InstaGene Matrix. The concentration and purity of extracted DNA were determined by NanoDrop spectrophotometer. Three sets of specific primers to the human β-globin gene were used to evaluate the DNA fragment lengths, by amplifying 110 base pair (bp), 536 bp, and 2000 bp products in the polymerase chain reaction (PCR). The results showed no significant differences in the cell-free DNA fragment concentrations and the prevalence of PCR products between using absorbent paper strips and washing technique in either gingivitis or periodontitis groups. Therefore, with the ease and rapidity of the technique, using the absorbent paper strips for the quantitative and qualitative investigation of cell-free DNA fragment in patients with periodontal diseases instead of washing technique is recommended. Further studies are still required to confirm this finding in a large group of patients as well as in patients with other systemic health problems.

Converter transformer is an important equipment in HVDC system and it is the key to the stable operation of the whole power transmission and distribution system. Unlike the traditional AC transformer, the oil-paper insulation of converter transformer will receive both AC and DC voltage. So the requirement for the structure design of oil-paper insulation system will be more stringent. It is of great engineering significance to study the electric field distribution of converter transformer and to study the influence of different oil-paper insulation configuration on the electric field distribution in the internal insulation of converter transformer. In this paper, first, an oil-paper insulation structure of converter transformer is established and electric field distribution under AC/DC composite voltage is studied. Then change the thickness and layers of pressboard, the distance of oil channel and the oil-paper ratio to get different oil-paper configurations. Use the simulation software to calculate the electric field distribution under the different oil-paper configurations. Finally, the influence of different oil-paper configuration on the electric field distribution of internal insulation structure of converter transformer is analysed which will provides significant reference for the internal insulation design of converter transformer.

We developed a new protein crystallization method that incorporates paper. A small piece of paper, such as facial tissue or KimWipes, was added to a drop of protein solution in the traditional sitting drop vapor diffusion technique, and protein crystals grew by incorporating paper. By this method, we achieved the growth of protein crystals with reducing osmotic shock. Because the technique is very simple and the materials are easy to obtain, this method will come into wide use for protein crystallization. In the future, it could be applied to nanoliter-scale crystallization screening on a paper sheet such as in inkjet printing.

The conductive paper has been of great interest due to its flexibility and superior properties. In this work, the facile procedure with scalable possibility was used to prepare conductive paper with graphene oxide (GO) and reduced graphene oxide (rGO). GO synthesized by the modified Hummers’ method was successfully transformed to rGO using ascorbic acid. These GO and rGO were used as a conductive source to improve conductive properties of the as-prepared paper. GO and rGO (0 – 25 wt%) were mixed with nanofibrillated cellulose (NFC) to form conductive paper. Results showed that the reduction of the electrical resistance was found from both GO/NFC and rGO/NFC paper sheets with increasing a content of GO or rGO. Furthermore, the paper with rGO exhibited more outstanding electrical conductive than the GO/NFC paper. Also, the water uptake of the conductive paper was affected by the addition of GO or rGO. The significant reduction of water uptake was found to be more pronounced with the introduction of rGO in comparison with the presence of GO. The conductive paper prepared in this study would be useful for applications such as flexible electrode.

Transformers are an important part of the power transmission and distribution process of power systems. Designing and manufacturing a stable transformer is essential for the stable operation of the entire power system. Accordingly it is critical for the stable operation of the entire power system to design and manufacture a stable transformer. In order to improve the composite insulation performance of the oil-paper in power transformer, studying the polarization characteristics of oil-paper composite insulation is essential. In this paper, the polarization characteristics of high external applied voltage and different oil-paper composite insulation structures are studied. In the three-electrode system, the cardboard has obvious polarization characteristics at the two poles, and the polarization characteristics are most obvious when the cardboard is at the high pressure pole. The initial value and the attenuation function of the polarization and depolarization current do not match the laws determined by the RC circuit. When the voltage is at a higher level, the difference between the initial values of the polarization and depolarization currents at different positions of the cardboard at the same voltage level is greater, and the polarity effects are more obvious. the above rules still exist when the distance between the electrodes is changed.

This paper presents the use of Escherichia coli as an anode in a paper-based microfluidic urea fuel cell (P-based μUFC). For the construction of this P-based μUFC, a saline solution with E. coli bacteria was deposited on carbon cloth and used as an anode for urea oxidation, furthermore, a piece of Toray® carbon paper was impregnated with Pt/C and used as an cathode to reduce the oxygen present in the air. The P-based μUFC proved with a urea solution of 0.33 M, showed an open-circuit voltage of 0.83 V, a maximum current density of 3.253 mA cm-2 and a maximum power density of 0.608 mW cm2, these values were similar to report when human urine was used as fuel. The microfluidic fuel cell developed was evaluated for 20 consecutive days at room temperature in order to observe the lifetime of the bacteria with respect to the power generated. This work represents an advance in the possible use of physiological fluids such as urine to generate electrical energy in non-implantable medical devices.

Supercapacitor have attracted much attention due to its fast power supply, long cycle life, simple principle, etc. Supercapacitors are widely used in consumer electronics. Activated carbon is a typical material for electric double layer capacitor. Here, we study the electrochemical performance of an activated carbon (TF-B520) bulky paper electrode made by vacuum filtration method. Cyclic Voltammetry and Constant Current Charge/Discharge were used to test the electrode capacitance and the rate performance. The results showing that TF-B520 activated carbon balky paper electrodes have the highest capacitance of 120F/g at scan rate 1mV/s and good capacitor behaviour at scan rate below 20mV/s and current density below 250mA/g.

A simple wind speed measurement device, a paper anemometer, is fabricated based on the theory of standing waves. In providing the working profile of the paper anemometer, an experimental device is established, which consists of an anemometer sensor, a sound sensor, a microphone, paper strips, a paper cup, and sonic acquisition software. It shows that the sound wave detected in the paper cup has a larger amplitude and the noise is depressed, though the frequency of the sound is twice that detected directly from the strip. From the experiments, we find that the frequency of the sonic wave does not change with wind speed; however, its amplitude increases with wind speed. To predict the wind speed, a correlation is established from the sound wave amplitude.

We report a simple experiment that clearly demonstrates a common error in the explanation of the classic experiment where a small piece of paper is put over a book and the system is let fall. This classic demonstration is used in introductory physics courses to show that after eliminating the friction force with the air, the piece of paper falls with acceleration g. To test if the paper falls behind the book in a nearly free fall motion or if it is dragged by the book, we designed a version of this experiment that includes a ball and a piece of paper over a book that is forced to fall using elastic cords. We recorded a video of our experiment using a high-speed video camera at 300 frames per second that shows that the book and the paper fall faster than the ball, which falls well behind the book with an acceleration approximately equal to g. Our experiment shows that the piece of paper is dragged behind the book and therefore the paper and book demonstration should not be used to show that all objects fall with acceleration g independently of their mass.

The purpose of this study was to determine the effect of active paper placement methods on super red dragon fruits quality during storage at ambient temperature. The active papers were incorporated with oleoresin of cinnamon leaf distillation residues. Various active paper placement methods were applied such as wrapping, placed on the cardboard wall, placed cardboard pad, and scrap of paper on the sidelines. Weight loss, peel color, surface and flesh hardness, total titratable acid, soluble solid total, pH flesh fruit, and total plate count (TPC) of super red dragon fruits samples were investigated during 9 days storage. The result shows that active paper placement methods significantly affected the weight loss, surface firmness and color peel change of super red dragon fruits samples. However, active paper placement methods insignificantly affected the titrable acid total, soluble solid total, pH, flesh firmness and microbial spoilage of super red dragon fruits samples. The best method to maintain the super red dragon fruits quality was wrapping method.

The purpose of this study was the development and testing of a near-field communication (NFC) tag for cold chain monitoring. In this paper, we validated the use of large-surface printing technologies to make a high-frequency antenna (13.56 MHz) and carbon-based temperature sensor on an Arjowiggins' Powercoat™ paper substrate. The printed temperature sensor was connected to the output of the analog–digital converter of a commercial microprocessor. A direct temperature reading interface was developed. The main objectives were to demonstrate the potential of screen printing processes for the development of an NFC tag, and to validate the use of a printed resistive sensor for cold chain monitoring. The validation was carried out through the comparison of a reference temperature recorded by a thermocouple regarding the temperature recorded by the external printed sensor in the case of a cold chain break simulation.

Oleoresin of kaffir lime leaves distillation residue still contains some active compounds such as Citronellal, β-Citronellol, and Linalool which potential to incorporated on the active paper packaging. The purposes of this study were to determine the effect of kaffir lime leaves distillation residue oleoresin concentration on the physical characteristics, sensory characteristics, and antimicrobial activity of the active paper packaging incorporated with kaffir lime leaves distillation residue oleoresin and to determine the functional groups of active paper packaging. The concentration of kaffir lime leaves distillation residue oleoresin were varied at 0%, 2%, 4% and 6%. The result showed that the addition of kaffir lime leaves distillation residue oleoresin increased the thickness and moisture content of the paper and decreased the tensile strengths and folding endurances of active paper packaging. The microbial inhibition tends to increase along with the higher oleoresin concentration addition. Aromatic CH group were found at a wavelength of 897.90 cm-1 of on paper packaging with 2% oleoresin indicated as functional aromatic functional group allegedly obtained from the kaffir lime leaves oleoresin.

In the paper, existing research and operating experience was summarized. On the basis, the particularity of oil-paper insulation operation condition for converter transformer was combined for studying the influence of temperature on oil-paper insulation field intensity distribution of converter transformers under different AC contents within wide temperature scope (-40°C~105°C). The law of temperature gradients on space charge accumulation was analyzed. The breakdown or flashover characteristics of typical oil-paper compound insulation structure under the action of DC, AC and AC-DC superposition voltage at different temperatures were explored. The design principles of converter transformer oil-paper insulation structures in alpine region was proposed. The principle was adjusted and optimized properly according to the operation temperature scope and withstood AC-DC proportion. The reliability of transformer operation was improved on the one hand, and the insulating medium can be rationally utilized for reducing the manufacturing cost of the transformer on the other hand.

We describe a method for fabricating paper-based microfluidic devices using a commercially available CO2 laser system. The method is versatile and allows for controlled through-cutting and ablative etching of nitrocellulose substrates. In addition, the laser system can cut a variety of components that are useful in the fabrication of paper-based devices, including cellulose wicking pads, glass fiber source pads and Mylar-based substrates for the device housing.

Reduction of graphene oxide is primarily important because different reduction methods may result in graphene with totally different properties. For systematically exploring the reduction of graphene oxide, studies of the temperature-dependent electrical properties of graphene oxide (GO) are urgently required. In this work, for the first time, broadband dielectric spectroscopy was used to carry out an in situ investigation on the transition of the electrical properties of GO paper from -40 to 150 °C. The results clearly reveal a very interesting four-stage transition of electrical properties of GO paper with increasing temperature: insulator below 10 °C (stage 1), semiconductor at between 10 and 90 °C (stage 2), insulator at between 90 and 100 °C (stage 3), and semiconductor again at above 100 °C (stage 4). Subsequently, the transition mechanism was discussed in combination with detailed dielectric properties, microstructure and thermogravimetric analyses. It is suggested that the temperature-dependent transition of electronic properties of GO is closely associated with the ion mobility, water molecules removal and the reduction of GO in the GO paper. Most importantly, the present work clearly demonstrates the reduction of GO paper starts at above 100 °C.

Conventional bricks are the most elementary building materials for houses construction. However, the rapid growth in today's construction industry has obliged the civil engineers in searching for a new building technique that may result in even greater economy, more efficient and durable as an alternative for the conventional brick. Moreover, the high demands for having a speedy and less labour and cost building systems is one of the factor that cause the changes of the masonry conventional systems. These changes have led to improved constructability, performance, and cost as well. Several interlocking bricks has been developed and implemented in building constructions and a number of researches had studied the manufacturing of interlocking brick and its structural behaviour as load bearing and non-load bearing element. This technical paper aims to review the development of interlocking brick and its structural behaviour. In conclusion, the concept of interlocking system has been widely used as a replacement of the conventional system where it has been utilized either as load bearing or non-load bearing masonry system.

We report the realization of a resettable resistive switching device based on a nanostructured film fabricated by supersonic cluster beam deposition of gold clusters on plain paper substrates. Through the application of suitable voltage ramps, we obtain, in the same device, either a complex pattern of resistive switchings, or reproducible and stable switchings between low resistance and high resistance states, with an amplitude up to five orders of magnitude. Our device retains a state of internal resistance following the history of the applied voltage similar to that reported for memristors. The two different switching regimes in the same device are both stable, the transition between them is reversible, and it can be controlled by applying voltage ramps or by mechanical deformation of the substrate. The device behavior can be related to the formation, growth and breaking of junctions between the loosely aggregated gold clusters forming the nanostructured films. The fact that our cluster-assembled device is mechanically resettable suggests that it can be considered as the analog of the coherer: a switching device based on metallic powders used for the first radio communication system.

We study how paper microstructure heterogeneity affects the electrostatic field acting on toner particles during xerographic printing. We use an efficient multigrid Poisson solver to simulate electrostatic fields. The dielectric distribution of paper is obtained either analytically or input numerically using a recently developed 3D fibre network model of paper. Simulations are used to elucidate the relative importance of paper surface, filler and porosity variations in establishing spatial variations of the electrostatic field. It is found that only long wavelength variations of surface height, bulk filler or porosity variations affect variations in electrostatic transfer forces to any relevant degree. Furthermore, we show that the effect of these long wavelength perturbations can be modelled using a new 1D effective capacitor model. When surface variations and surface filler are mixed together, we found the interesting result that mode mixing can decrease the spatial fluctuations of the electric field. Finally, using simulated 3D paper webs, which mimic the properties of laboratory handsheets, we find that to lowest order surface roughness and not formation is responsible in controlling variations of the electrostatic transfer field, a result of importance in digital printing onto stochastic printing substrates, such as commercial paper.

Multi-walled carbon nanotubes (MWNT) and polyaniline are coated on an electro-active paper (EAPap) to improve the performance of the bending actuator, and its performance is tested. EAPap actuators made with cellulose paper have merits in terms of large bending displacement, ultra-lightweight, dryness, low actuation voltage and power consumption, low cost and biodegradability. However, the force output of actuators is small and the actuation frequency is low. Thus, MWNT and emeraldine salt polyaniline (PANI) are coated on the EAPap material to improve the force and the actuation frequency. The MWNT and PANI solution is made by sonication, and the sonication time and the weight per cents of the MWNT and PANI are optimized to improve the hybrid actuator performance. The optimum condition is associated with conversion of the partial conductive state PANI into the emeraldine formed PANI by the chemical bonding between the MWNT and PANI. The performance improvement of the EAPap actuator coated with MWNT/PANI is investigated in terms of displacement, blocking force and efficiency. In the presence of an electric field (0.35 V µm−1) on the hybrid EAPap actuator, 250% of the output force, 160% of the resonance frequency and 50% of efficiency are improved.