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The results of measurements of the main electrophysical characteristics of industrially manufactured electrical insulating paper and laboratory castings made of bamboo and pine cellulose, including the addition of bacterial cellulose with different concentrations (from 0% to 5%) are presented. In particular, the breakdown voltage and mechanical tensile strength of electrical insulating paper in the process of artificial thermal aging were determined. The change in the mechanical strength of the paper is compared with the change in degree of polymerisation of cellulose macromolecules. The sorption capacity of electrical insulation paper of different composition is compared. The explanation of the revealed regularities is given. The possibility of manufacturing high thermal stability electrical insulating paper from cellulose with an initially low degree of the macromolecules polymerisation, in particular, from bamboo cellulose, is shown.

The influence of the electret on the properties of craft paper modified with polycaprolactone is shown in this article. When applying a polymer coating, a change in the surface properties of the pulp and paper material occurs, which is reflected in the wetting parameters. Processing pulp and paper materials in the field of a unipolar corona discharge leads to an increase in their mechanical characteristics and a decrease in roughness and air permeability.

Surface-Enhanced Raman Scattering (SERS) performance of filter paper (FP) loaded with gold nanoparticles (Au NPs) of three different size/shapes (spherical, triangular and star) were investigated. Spherical Au NPs were synthesized using femtosecond laser ablation of Au target in distilled water and other two anisotropic (triangular and star-shaped) Au NPs were prepared by colloidal chemical methods. COMSOL Multiphysics simulations were performed to investigate near field distributions of these Au NPs and as expected, the strongly enhanced near-field intensity at the sharp features was observed. The SERS performance [using the dye molecule Nile Blue (NB)] of star-shaped Au NPs loaded FP was superior compared to the triangle and spherical Au NPs loaded FP due to the presence of sharp tips and thus it was proved to be capable of detecting 10 pM NB concentration with an estimated enhancement factor of ∼3.7×1010.

Indonesia has targeted to reach 23% of renewable energy share by 2025. In order to meet the target, many researchers have focused on the explorations of renewable energy resources. One of the potential solutions to meet the target is the agricultural wastes, include corn cobs and areca nut fiber. In this study, the calorific value of corn cobs and areca nut fiber are tested. The corn cobs and areca nut fiber are collected from the farmers in Sumatera Utara province of Indonesia. In addition, the Paper waste is also tested. A bomb calorimeter of IKA C6000 is used to measure the energy content of the biomass. The results show that the calorific value of Corn cobs and Areca nut fiber is 5573 Cal/g and 4946 Cal/g, respectively.By using the average yearly production of Corn and Areca nut, these calorific values similar to 4,539 TOE and 4,653 TOE, respectively. If the potency can be used to replace the coal as an alternative fuel, this potency will reduce the Greenhouse gas (GHG) emission. The potency of mitigation GHG by replacing Corncob and Areca nut fiber are 18,306 and 18,491 ton of CO2e.

We report a liquid metal microstrip antenna on a printing paper whose resonant frequency was tunable by folding the paper. The gallium-based alloy was used as liquid metal, which is instantly oxidized in ambient air. The oxidized liquid metal is easily wettable on printing paper surfaces, while it is non-wettable on laser-printed toner surfaces. An antenna with a 3 mm wide and 39 mm long copper-liquid metal overlapped-feedline linked to the liquid metal microstrip rectangle-shaped patch (40 × 31 mm2) was designed. The antenna pattern was printed on a printing paper using a laser printer. A liquid metal soaked roller was rolled on the antenna pattern printed paper, resulting in a liquid metal pattern where there was no toner. The resonant frequency of the liquid metal on the paper microstrip patch antenna was 2.88 GHz with −18.5 dB S11. The measured characteristics of the antenna were in good agreement with the simulation results. When the antenna was folded, the resonant frequency was changed to 2.68 GHz (x-axis folding) or 2.72 GHz (y-axis folding). Liquid metal on paper fabrication is simple but effective for creating custom-designed antennas that are easily re-designed and fabricated in the field.

Borassus flabellifer L. becomes one of the palm-based commodities in Indonesia that can grow well in dry areas, especially around the north coast of Java Island. An abundant waste of this plant, in the form of leaf midrib and fruit fiber, has a potential as a source of lignocellulose for the paper industry. In the present study, Kraft paper production was conducted to know the influence of the proportion of leaf midrib and fruit fiber of Borassus flabellifer L., and the concentration of Polyvinyl Acetate (PVAc) adhesives on the sensory and physical quality of Kraft paper. The research method was a Randomized Block Design (RBD) with two factors. The Friedman test was used to determine the sensory quality of Kraft paper. The ANOVA analysis was used to examine the physical quality of Kraft paper. The results showed that the treatment of raw material proportion and PVAc adhesive concentration had significant effect on color, surface texture, yield, and tensile resistance, but insignificant between treatment of Gramatur and tear resistance. The best treatment of sensory tests was Kraft paper with proportion of 50% leaf midrib pulp, 50% fruit fiber pulp, and 7.5% PVAc adhesive concentration. It has a yield value of 72.11%, Gramatur of 162.80 (g/m2), tensile strength of 1.70 (%), and tear resistance of 197.6 (gf).

A Carbon dioxide (CO2) emission from the boiler is one of the primary sources of greenhouse gas (GHG) which must be reduced. Nowadays, the boiler emissions discharged into the atmosphere has not been utilized yet. An experiment of Spirulina platensis cultivation in laboratory scale with the addition of CO2 flue gas of coal-fired boilers has been done. CO2 flue gas with a flow rate of 0.25-0.75 L/min was added into paper mill effluent as the growth medium of Spirulina platensis. The biomass growing of Spirulina platensis, pH of medium and CO2 captured during the experiment were observed. The result indicated that CO2 flue gas of coal-fired boilers of the paper mill could be utilized for cultivating of Spirulina platensis. The biomass productivity of Spirulina platensis in the amount of 220 mg/L.day or 39 g/m2.day could be obtained with the addition of CO2 flue gas in the flow rate of 0.75 L/min. Spirulina platensis contains protein, fat, fiber, ash and amino acids. It also contains sodium, calcium and magnesium. But it has no cadmium content. It is potentially be used as animal dietary supplements. CO2 flue gas from the boiler emission can be used for cultivation of Spirulina platensis and contribute in reducing of CO2 gas boiler emissions like greenhouse gases (GHG) by 0.20% of total CO2 added.

Paper-based evaporation concentrators with linear and radial geometries are compared. A new method of finding approximate analytic solutions of the advection–dispersion equation is proposed, based on the behavior of concentrators with infinite sources. Analytic approximations are compared with numerical solutions, and the advantage of radial concentration is highlighted: linear concentration rates scale with the square root of the Péclet number Pe while radial rates scale with Pe itself, leading to faster radial concentration beyond a critical value. Experiments are performed with Brilliant Blue FCF dye, using optical transmission and the Beer–Lambert law for quantitation. Dye concentrations are chosen for operation in the linear absorbance regime. Radial concentration is demonstrated under ambient conditions on filter paper disks with 60 mm diameter evaporation areas fed from a perimeter source, in a reverse of the well-known “coffee stain” experiment. Airflow enhanced concentration in strips and wedges is compared directly, using laser-patterned chromatography paper. The advantage of radial concentration is confirmed (and enhanced by diversion of concentrate to the corners of strips) and concentration factors greater than [Formula: see text] (the dynamic range of measurement) are obtained in ∼2 h using 30 mm long columns.

Due to high concentrations of organic matters and total solids, the effluent generated from recycled paper mill (RPME) requires appropriate treatment prior to discharge. The thermal condition of an anaerobic system has a major effect on the biodegradation processes of total solid substrates. In this study, the biodegradation of RPME was evaluated in a modified anaerobic inclining-baffled reactor (MAI-BR) under sub-mesophilic (29 °C), mesophilic (37 °C) and thermophilic (55 °C) conditions. The concentration of VSS, TDS, TSS lignin and VSS/TSS ratio in MAI-BR’s compartments were studied. The results showed that Compartment 1 had TSS of 15682, 13305 and 12145 mg/L; particles size of 621, 559 and 500 µm; VSS of 9662, 1776 and 10923 mg/L; and TDS of 594, 730 and 1873 mg/L at sub-mesophilic, mesophilic, and thermophilic conditions, respectively. An increase in the reactor temperature, an overall reduction in TSS and particles size, and an increase in VSS, VSS/TSS ratio, TDS, and lignin were observed. Under thermophilic conditions, the VSS/TSS ratio was higher than in mesophilic conditions, while lignin became harder to remove. These results conclude that operating the reactor at thermophilic has reduced the digested sludge within the system and enhanced the solid fraction biodegradation process of RPME.

In the present work, spontaneous imbibition of shear-dependent fluids is numerically investigated in a two-layered, rectangular/fan-shaped, paper-based diagnostic kit using the modified Richards equation. It is shown that the average velocity at the test line of the kit is strongly influenced by the absorbent pad's microstructure with its contact angle playing a predominant role. Assuming that the test fluid is shear-thinning, a generalized version of the Richards equation, valid for power-law fluids, was used to investigate the effect of shear-thinning on the quasi-steady regime. The shear-thinning behavior of the test fluid is predicted to shorten the duration of the constant-velocity regime on the nitrocellulose membrane used as the test cell. By manipulating the contact angle and/or choosing appropriate microstructure for the absorbent pad, it is still possible to establish a constant velocity regime at the test line for nearly five minutes even for such fluids. A comparison between our numerical results and published numerical results obtained using simplistic theories has revealed the key role played by the transition, partially saturated zone near the advancing front during the liquid imbibition. The general conclusion is that use should preferably be made of robust models such as Richards equation for the design of lateral-flow, paper-based assays.

The art of paper cutting, kirigami, provides dynamic, programmable control surfaces for changing flow conditions.

The parameter of tensile strength for transformer bushing insulating paper occupies an important position in the structural design and life evaluation of transformer bushing. In order to precisely achieve the effect of aging time and moisture content on the tensile strength of transformer bushing paper, transformer insulating paper samples with a thickness of 0.13 mm were prepared for tensile strength and dielectric strength testing under different moisture contents and aging states. The results show that the tensile strength (MPa) of insulating paper decreases linearly in the range of 0–648 h under accelerated thermal aging at 130 °C. However, there is a more serious exponential decline in the tensile strength (MPa) of insulation paper with its moisture content is boosted. The moisture content in insulation paper is the most important factor for insulation paper deterioration in oil-impregnated paper insulation equipment, which could accelerate the end of insulation service life. The value of capacitance increment ΔC of the insulation paper samples displayed closely linear growth with a moisture content from 0.5% to 5.9%. Strictly controlling the moisture content by monitoring the ΔC value of transformer insulation paper is of significance for prolonging its service life.