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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.

Surface-enhanced Raman scattering (SERS), a simple, highly sensitive, and fast analytical method can be used to detect corrosion components on the surface of bronze ware, a difficult problem. The silver mirror reaction is suggested for depositing precious metal nanoparticles on cellulose filter paper in order to create a quick, easy, and low-cost approach for creating SERS substrates. After an 8-minute deposition time, optical microscopy and scanning electron microscopy (SEM) revealed a uniform dispersion of precious metals on cellulose filter paper. To examine the SERS characteristics of the substrate, copper chloride oxide, the main ingredient in the damaging rust of trace bronze ware, was used as the probe molecule. The findings show that cellulose filter paper with a uniform distribution of precious metals achieves the best SERS performance. The flexible substrate enables effective trace analysis of damaging rust on bronze surfaces.

In order to reasonably evaluate the effectiveness of UHF sensor arrangement in online monitoring of partial discharge of bushing, it is necessary to study the electromagnetic wave propagation characteristics of partial discharge UHF in the bushing. In this paper, a three-dimensional model of a real transformer bushing is established, the XFDTD software is used to simulate the raised seat defects and internal capacitive core defects of the bushing, field strength sensors are arranged at different locations inside and outside the bushing, and the propagation process of partial discharge UHF signals leaking from the oil-paper insulated bushing to the external free space is simulated and analyzed. The results show that the time difference between the signals received by the field strength sensors at different locations is not significant and can be neglected in practice. The partial discharge electromagnetic wave signal generated by the bushing elevated seat defect leaks from the upper porcelain sleeve to the external space, and the leaked electromagnetic wave energy is mainly gathered at the upper and lower ends of the upper porcelain sleeve. The partially discharged electromagnetic signal at the capacitor core inside the bushing will propagate along the coaxial waveguide structure formed between the capacitor screens towards the two ends of the capacitor core, the downward propagating electromagnetic wave energy is confined within the elevated seat, the upward propagating electromagnetic wave energy propagates from the top of the upper porcelain bushing to the external space, the leaked electromagnetic wave energy is mainly concentrated at the top of the upper porcelain bushing. The simulation results provide ideas for optimizing the arrangement of external antenna sensors for UHF detection of partial discharges in transformer oil-paper insulated bushings.

This paper reports the use of non destructive, microstrip patch antenna as paper moisture sensor. Microstrip patch antenna is designed to resonate at 2.4GHz. This design is simulated and fabricated on copper clad type FR4 (εr= 4.4) having thickness of 1.6mm. Patch dimension are 27mm × 30mm and substrate dimension is 63mm × 60mm. The microstrip transmission line is used to provide excitation for the antenna. This design for microstrip patch antenna after fabrication showed a resonance at 2.38 GHz on vector network analyzer at S11=-19.38dB with impedance =49Ω. The variations in frequency in relation with water content in the paper is measured using Vector Network Analyzer by placing wet paper on the patch antenna. Moisture content in the paper was found out by taking wet weight and dry weight of the paper. The model of the wet paper is recommended primarily on the basis of water-dry paper reactions, along with the thickness and surface roughness explaining tendencies of the sensitivity graphs. Paper samples of 13 different types, with different GSM values and thicknesses, havingdimensions same as that of the substrate were tested. From the results it is observed that as the moisture content in the paper increases the frequency decreases. The change in frequency with respect to the moisture content is seen to have quadratic relation with moisture. The variations in the frequency are fitted in the form of equations. The calculated %Mwet indicates an error around ±0-4% in the calculated value as compared to the actual value. The response of sensor is almost linear with respect to the references but the coefficients depend non-linearly with the paper dimension.

This experiment initially explored the clean production process of nanocellulose fibrils (NFC) using commercial softwood pulp as raw materials, and selected appropriate biological enzyme pretreatment to prepare NFC1 with a higher concentration. Compared with NFC2 obtained by TEMPO oxidation method, it is found that the diameter of NFC1 obtained by enzymatic pretreatment method (10-30nm) is similar to that of NFC2 (20-30nm). But the length of NFC1 (1-4μm) is much longer than the length of NFC2 (400-600nm). In addition, the influence of two kinds of NFC on the physical strength of paper is also explored. Experimental results show that: NFC1 is better than NFC2 in enhancing the physical strength of paper. And when cationic starch and NFC act synergistically, the enhancement effect is obviously better than using NFC alone or cationic starch alone. When the addition amount of NFC1 is (1.5±0.5)%, the tensile index, burst index, and tear index of the resulting paper increase by (43±3)%, (55±1)%, (37±2), respectively %. When the amount of NFC2 added is (1.5±0.5)%, the paper tensile index is (29±2)%. When the amount of NFC2 added is about (3±1)%, the paper’s bursting index and tearing index growth rate are (29±1)% and (33±1)% respectively.

Determining the optimal clusters can be regarded as a grouping problem that has produced many cluster approach methods in various studies. Each method has provisions that can solve one or more grouping problems in generating information from data set with a number of k being tested. The advantages and disadvantages of each method actually complement to each other in solving the grouping problems. This paper aims to describe the performance of cluster approach methods in determining the optimal clusters through a review by paying attention to the criteria of the problem which is an obstacle to the grouping problem. The results of this review are expected to be a reference for developing the new optimal cluster approach method through possible combinatorial optimization.

The traditional Chinese folk paper-cutting art has a long history. It is a traditional folk art form created by working people to satisfy their spiritual and material pursuits. It originates from life and returns to life. With the pace of the times, folk paper-cutting has undergone an innovative transformation and development through the interweaving, penetration and integration of contemporary design concepts. Through the combination of network big data, it provides a large number of references for modern graphic design decoration and function combination, graphic context inheritance, color language, modeling language, etc.

When partial discharge occurs in the power transformer, the arc can further develop on the oil-paper interface between high and low potentials, and then form a path, resulting in large-area flashover. This will lead to a wide range of insulation damage, insulation failure, equipment shutdown and even large-scale economic losses. For the insulation damage caused by surface discharge of oil paper insulation, relevant scientific research institutions have carried out a large number of experimental studies. However, limited by the test conditions, the research focuses on the small-size model below 50mm, and mostly adopts the test device of uneven electric field. The research on the “large-size“ of the same scale inside the transformer is still blank. In this study, an oil-paper insulation surface discharge test platform with a large size of 50-150mm is built, the electric field conditions at the oil paper interface during the operation of transformers in engineering are simulated, and the surface discharge test of insulating paperboard is carried out by taking the same sample processing means as the engineering. Combined with the test results, a typical design optimization case of setting along surface corner ring to improve the allowable value of along surface discharge field and enhance along surface insulation margin is proposed. It lays a foundation for enriching the transformer oil-paper insulation design parameter system and improving the transformer oil paper insulation performance and operation reliability.

A tapered glass capillary MeV-ion microbeam setup, previously home-developed, was recently upgraded. To check the upgraded microbeam system quality and accuracy, microbeam particle induced X-ray emission (PIXE) mapping of potassium permanganate (KMnO4) solution diffusion in filter paper was carried out to study how the measured solvent diffusion followed the diffusion laws. Two initial boundary conditions and diffusion situations were applied: (1) the paper vertically placed in air with one end soaked in the solution for ten minutes, and (2) the paper horizontally placed on water with the solution dropped at a side of the paper for three minutes. 2-MeV-proton microbeam PIXE analyzed the paper pixel by pixel and the GUPIXWIN software was used to calculate the elemental concentrations in the pixels to map the concentration changes in the pixels as a function of the distance between the pixel position and the origin of the solution. The resulting maps demonstrated the solution diffusions in two cases indeed well following the diffusion laws, a steady-state diffusion dominated process where the elemental concentration was a linear function with the distance but joined by other non-diffusion factors for case 1, and a pure diffusion process where the elemental concentration was an error function with the distance for case 2.

Detection and identification of potassium ion (K+) level in urine is essential for diagnosis of several deseases or for guiding treatments. We have developed a simple, rapid, low cost and naked-eye quantitative method for K+ analysis in urine using a paper-based colorimetric array test strip. The array comprised three sensing elements printed using a wax-printing technique and filled with different amounts of crown ether (4-aminodibenzo-18-crown-6) modified gold nanoparticles (AuNPs). The detection is achieved by measuring the color change (from red to violet) when AuNPs aggregated following crown ether-K+ complexation. Furthermore, the detection sensitivity could be controlled by changing the amount of the crown ether. The strip sensor array based on crown ether modified AuNPs successfully detected K+ level in the ranges of 5-1000 µM by naked eye. Thus, the developed sensor is very simple yet has a potential to be of real use in detecting K+ in real urine samples.

Coconut fronds are part of a coconut tree that has been rarely used while the amount is abundant. Therefore, there is a concern of how to more utilize coconut fronds. Coconut fronds can be used as raw material for making art paper because it has good amount of fiber and cellulose. The utilization of coconut fronds for making art paper can minimize the coconut fronds waste. Additionally, it also has an impact on forest conservation, since most of raw materials for paper pulp are coming from woods in the forest. The objective of this study is to utilize coconut fronds as agricultural solid waste as raw material for making art paper. The method used to make the paper is chemical pulp, which including pulping and bleaching, as well as art paper molding. The prepared art paper was then characterized by tensile strength test, strength test stretch and grammature. The art paper samples that have been prepared met the minimum SNI grammature of 100 g/m2. While, for the best tensile resistance test was about 19,800 for sample 30/75. Meanwhile, the best stretch resistance test was 0.955 for sample 60/75.

Lignin is one of the constituent component of wood, but the presence of lignin can be a nuisance in the paper making process. Lignin will reduce the physical and optical properties of paper. The objctive of this study is to determine the advantages of lignin-kraft and its impact to modify cationic starch on the physical properties of fine paper. The study was conducted in steps. In the first step extraction was carried out to obtain the kraft-lignin, by using two extraction methode that is acid extraction with termal and acid extraction with centrifuge. Kraft-lignin was tested from both methods, the optimum test value will be continued at the coocking stage into resin-lignin. Resin-lignin will be a modified compound with level addition 3% and 6% of the dry weigh of cationic starch, then it will be applied to the handsheet with 13 variation, namely blank;, DS existing (2 Kg/TP, 4 Kg/Tp, dan 6 Kg/TP), cationic starch emultion + resin-lignin 6%, cationic starch substitution + resin-lignin 3%, and cationic starch substitution + resin-lignin 6%. Variation of cationic starch substitution + resin-lignin 6% at level addition 6 Kg/TP indicates the best value of physical strength. Especially on tensile strenght, wet tensile strenght, bursting, tearing, dan internal bonding value.

Most papers are made from virgin wood-based pulp of hardwood sources but recently, softwood have received enormous attention as alternative to hard wood because the hardwood takes a significant number of years to mature enough for use in the pulp and paper industry unlike softwood which are majorly annual plants. The annual crop in focus in this work is the yellow open-pollinated variety of corn which generates tons of waste at harvest. A novel attempt is made to ascertain the viability of corn sheaths as raw material for the pulp and paper industry by carrying out a comprehensive analysis on the pulp and paper made from the pulp. The sheaths were dried, shred and cut into pieces suitable for the digester and the pulps obtained were analysed for physico-chemical properties. Hand sheets were also made using the generated pulp and its physico-mechanical properties were analysed. Results obtained were compared with pulp from corn husks from other parts of the country, three Nigerian fibre sources – silk cotton, bagasse and rice straw and other foreign non-wood sources and found to be of competitive properties. Pulp properties of Lignin content, ash content, cellulose, hot and cold water solubility of the fibres were 13.72 ± 1.21%, 1.27 ± 0.23%, 53.26 ± 1.11%, 15.20 ± 2.11 and 6.14 ± 2.43 respectively while the mechanical properties of paper from the pulp were Bursting strength (282.163 KPa m2/g), Tear strength (146.119), Tensile strength (257.6N/m) and Tensile Index (3.9Nm/g). It was found that in all properties, the corn sheath was better than the rice straw fibers but not as good as the silk cotton and bagasse fibers. However, the corn sheath has been identified, as a viable raw material for the pulp and paper industry in Nigeria.

Paper is the final product resulted from compression of fiber suspension of cellulose pulp, which is derived from wood or non-woody material. In this study, paper was made from mixture of pineapple leaves and sugarcane bagasse pulp (P:S, 100:0%, 80:20%, 60:40%, 40:60%, 20:80%, and 0:100%) at varying cooking liquor or NaOH concentration (1.5% and 3%) using semi-mechanical soda pulping method. Pulp characterisation (kappa number, tensile and tearing strength) was further carried out to ensure a stable pulp and paper quality. Results showed that the highest tensile strength of 6,709 kN was obtained at pineapple leaves and sugarcane bagasse pulp composition of 100:0% and NaOH 3%, whereas the highest tearing strength (1730,13 mN) was observed at the P:S of 40:60% with similar concentration of NaOH. The lowest kappa number (6,182) was also obtained at P:S of 0:100% and 3% NaOH. The pulp characterisation values have fullfil SNI No. 6519:2016 quality standard for plastic laminated paper.

Utilization of agro-based fibre for paper making has been the subject of interest in order to expand the usage of renewable resources as well as reduced the dependence on wood pulp. As one of the major countries in palm oil production, some of the waste from the oil palm plantation like the oil palm fronds, empty fruit bunches, and its leaf is a potential source of non-wood industry which can be used as raw material in the paper industry manufacture. This study was done to examine the potential of palm leaves to be used as a raw material of non-wood resources in the papermaking industry. In this study, sodium hydroxide (NaOH) pulping and process was employed to investigate the effectiveness of lignin removal for good fibre production. The concentration of the pulping agent was fixed at 7% at treatment of 1-7 hours to investigate the best condition for defibrillation of the cellulose fibre. Based on this study, it was found that the soda pulping produces fibre that can be molded into paper sheet without any binding agent. The morphology of the fibre observed under Scanning Electron Microscopy (SEM) shows that, soda pulping fiber consist of individual micro fibrils that are well separated. Both tensile strength and tear index gives highest value at 1.93 kg/cm2 and 37 Nm2/kg respectively at 7 hours treatment time. his reflects that lignin removal effectively occurred in soda pulping. Tensile strength found to increases with treatment time and both tensile strength and tear index of the paper falls within the value comparable to commerical non-wood paper. The paper produced has rough surface and has the potential to be develop for craft paper.

A method for detecting paper’s surface defects is proposed, which is based on mathematical morphology algorithm and computer vision technique. Firstly, the mean filtering and wavelet denoising in image pre-processing are used to eliminate the image noise, and wavelet analysis can achieve image enhancement and increase the contrast between the target area and the background. And then, an improved threshold Canny operator is used to segment the image to extract the complete scratch line and other defect edges. Finally, the target region features are coloured by mathematical morphology processing. The method’s stimulating result is verified in the Matlab software, from which we can conclude that the method’s detecting effect is very effective.

Paper and pulp industry factory is a factory that contributes to national economic development because paper needs per year can reach 100 million tons. But not only the positive impact is given, the negative impact is present because it produces considerable waste. The paper industry’s liquid waste is one of the many wastes containing a lot of metal, for example hexavalent Pb and Cr heavy metals. It is necessary to reduce according to government standards in order to reduce negative impacts on the environment. One way to reduce Pb and Cr levels is ion exchange using cation resin 500 ml paper liquid waste mixed with cation resin at a volume and weight ratio of 10: 0.0017; 10: 0,0034; 10: 0,0068; 10: 0,0136; and 10: 0.0272. Mixing is done with a 190 rpm stirrer motor and the variation of time used is 10, 20, 30, 40, and 50 minutes. The best treatment at a ratio of 10: 0.0272 with a time of 20 minutes. The results obtained by Pb and Cr decreased by 94% from the initial level.

Amperometric biosensor for glucose content measurement in Malaysian stingless bee honey was developed using screen printed carbon electrode (SPCE) integrated with paper disc immobilized with enzyme Glucose Oxidase (GOx) using simple physical adsorption method. The paper-based biosensor required only 8 μL of sample solution for glucose analysis. The calibration of glucose biosensor is linear between 0.5 mM to 4.5 mM (R2= 0.9925) and has a detection limit of 0.15 mM. Interference study on several compound affecting the biosensor response and storage stability was investigated. In addition, its performance was demonstrated in the analysis of six honey samples. The results obtained using glucose biosensor was validated by high performance liquid chromatographic (HPLC) method. The addition of glucose in pure honey at various concentration were also tested by this paper-based biosensor where the current obtained shows increasing trend with the addition of glucose. From this research, it can be concluded that, the prototype sensor to determine glucose adulteration in stingless bee honey was successfully developed.

This paper present product design and development of waste paper plastering mortars machine. This waste paper plastering mortar is manual machine system. The main element to make mortar is cement, sand, water and waste paper. These machines have two separate tanks, which is the first tank is to produce a pulp and second tank is to mix up the entire ingredient. The objectives of this research are to design a Waste paper plastering machine, to develop a functional prototype of Waste Paper Plastering Machine and also to test the machine by compare the best method by with machine and without machine to make plastering mortar. The testing has been done between preparation and procedure how to make plastering mortar with machine and without machine. This machine can be used in every household. This can save environment and reduce pollution.

Paper and plant extracts are materials that are cheap and easy to find everywhere, have great potential to be used as a portable, low-cost and biodegradable label for the application of chemical compounds detection. In this paper, we have explored potential methods for the label to detect ammonia gas, an indicator of meat spoilage, with the colorimetric principle. By immersing paper with plant extracts that are sensitive to ammonia, in this case, is anthocyanin from Ruellia simplex flower extract, the detection of ammonia at various concentrations can be achieved. Ammonia concentration used is 0; 0.005%; 0.025%; 0.1%, 0.25% and 0.5%. Color change images on the label when detection is scanned by a flatbed scanner. ImageJ software is used to quantify the color changes. Ammonia detection at various concentrations results in a color change from red to yellow on the paper label. Paper-based labels with discoloration that can be captured visually by the consumer’s eyes are considered as promising approaches to determine the freshness of meat.

Kidney failure is a degenerative disease that has a prevalence of nearly 12 to 15% of the total population in the world. Renal scans are one of many diagnostic means which refers to several examinations using radiopharmaceuticals that evaluate the function and anatomy of the kidneys. Technetium-99m-diethylenetriaminepetaacetic acid ([99Tc]Tc-DTPA) is a commonly used radiopharmaceutical for kidney scans. Since the half-life of technetium-99m radioisotope, one component of this radiopharmaceutical, is only about 6.0 hours, so an efficient and effective quality control techniques is a necessity. Up to now, two-systems thin layer chromatography (TLC) is a common method used for radiochemical purity (RCP) test of [99mTc]Tc-DTPA. Recently one-system TLC has been successfully developed for this purpose. Therefore prior to its application, it is necessary to validate as well to compare this method with an established method (WHO Pharmacopoeia). These methods were two-system used Whatman-1 paper as static phase and methyl ethyl ketone (two-system-A) and 0.9% sodium chloride (two-system-B) as mobile phases and one-system used Whatman-1 paper as static phase and acetone: 0.9% sodium chloride (11:9) as a mobile phase. RCP of [99mTc]Tc-DTPA was then tested using these methods. The retrieved data were processed and validated with some variables like accuracy, precision, and compared using t-test to see whether the above-mentioned TLC systems show a significant difference or not. The analysis results of RCP test of [99mTc]Tc-DTPA using two-system method was 99.37± 0.48% while using one-system method was 99.20 ± 0.41%. The percentage accuracy of the data between two methods was 99.83%. The t-stat value for both methods was 0.84 so it can be concluded that the results of measurement using one-system method are not significantly different from two-system method.

Sensors with accurate detection of various liquids have attracted increasing research interests in environmental protection and organic solvents transporation. In this paper, liquid sensor based on laser induced graphene paper (LIGP) was proposed, and successfully used for the rapid detection of micro volume liquid. The processing-structure-property relationship was systemically studied. LIGPs with different morphologies exhibited various sensitivities and showed good reproducibility and fast response. The response mechanism related to contact resistance between some adjacent graphene flakes/fibers was proposed. With the key findings, LIGP liquid sensors can be used as the detector for accurate identification of different solvents and have great potential in monitoring organic solvent leakages of pipelines and fabrication of smart anti-corrosion composite structures.

Kojic acid is an antioxidant used by the cosmetics industry but the excessive usage of kojic acid may cause harm to human health. Therefore, it is important to detect the content of kojic acid in cosmetic products. In this work, the low-cost and simple paper-based analytical devices (μPADs) based on double-sided adhesive tape were developed for the colorimetric detection of kojic acid. The μPADs were fabricated by dissolving double-sided adhesive tape in toluene and then making the patterned adhesive tape penetrate into the filer paper. Ferric nitrate was used as the reagent to react with kojic acid, and the product of their chelating reaction caused the color change from colorless to orange-red. The ImageJ software was used to analyze the color intensity and the corresponding correction curve was determined. The μPADs for the detection of kojic acid exhibited a wide linear range (0.05 - 4 mM) and the detectable limit was 0.05 mM. The good selectivity and reproducibility were also demonstrated.

Thermal paper is a special type of paper that is coated with chemicals on the paper layer to change color when exposed to heat. When discovering fingerprints by using chemical reagents such as ninhydrin solution with thermal paper, it shows black staining background on the heat-sensitive front side. Thus, the latent fingerprints cannot be discovered. In this study, we have reported the first utilization of ninhydrin with water glue in different ratios for the development of latent fingerprints on the thermal papers. The results showed that at 0.020-0.060 g/mL of water glue in ninhydrin solution reduced the black strain after tested with thermal paper and made the appearance of the fingerprint more clearly. So, the detectable minutiae can be used for visualization and identification of latent prints. Using an Automated Fingerprint Identification System (AFIS), it is showed between 59-87 points of minutiae. As the results, this method could be used as an alternative method to developing latent fingerprints with non-hazardous materials, reduce costs and easy to find.

This paper is devoted to study a structure of SiC-based materials using ultrasonic tomography method. The SiC-based materials were fabricated from preceramic paper using spark plasma sintering (SPS) method. Also as part of the study the Young's modulus and density of sintered materials were determined and the effect of sintering pressure changing to this parameters value was investigated. The preceramic paper is a composite material including a matrix of organic cellulose fibers and inorganic powder filler (SiC). The sintering temperature and pressure were 2373 K and 20-40 MPa, respectively. The holding time for the sintering process was 10 min. The density of sintered materials was investigated by the hydrostatic weighing method. Ultrasonic tomography was implemented using of single-channel sensor at 10 MHz frequency. © Published under licence by IOP Publishing Ltd. Russian Science Foundation, RSF: 19-19-00192 The research was supported by the Russian Science Foundation (grant No. 19-19-00192) as well as by

The algorithm and the experience of implementing automated systems for monitoring the quality of waste in the pulp and paper industry in the framework of a unified system of industrial environmental control are being considered. The required list of wastewater parameters subject to automated control is determined. The main technical and operational characteristics of automated wastewater quality control instruments included in the unified state register of measuring instruments are being considered. The problems of introduction of automated wastewater quality control systems in the Russian Federation are being considered.

H1 NMR relaxometry is a method that is extremely sensitive to the presence of magnetic nanoparticles, which significantly affect the transverse relaxation time of the water proton. Accordingly, the use of magnetic nanoparticles as labels allows detection of even extremely small amounts of the test substance. This paper analyzes the prospects for applying the method of solid-phase NMR-relaxometric determination of biologically active molecules. The nitrocellulose membranes are chosen as a solid phase and nanoparticles based on iron core with a carbon shell are used as magnetic labels. The possibility of detecting small concentrations of magnetic particles in porous medium is demonstrated. Finally, the ability to detect extremely low concentrations of an analyte, in this case, streptavidin protein (0.5 ng/ml to 100 ng/ml), which is actively used in various fields of biology and medicine, is demonstrated. © Published under licence by IOP Publishing Ltd. Russian Science Foundation, RSF: 17-15-01116 The work was carried out within the Russian Science Foundation project 17-15-01116. equipment of the Ural Center for Shared Use Modern nanotechnology UrFU was used.

The focus of this study is to analyze whether there are differences in the difficulty index of items if the same items are displayed with the Paper Based Test (PBT) model and the Computer-Based Testing (CBT) model. The PBT and CBT models have the same paradigm of measuring estimated abilities but have differences in the context and feel aspects. These differences include the number of items in the range of eyesight, use of tools, how to work on items, basic knowledge needs about computer operations, and habit factors. These differences can affect the results of estimating the ability of test participants. This study uses development methods and quantitative methods. Development methods are used to develop package items and CBT software. Two groups of respondents were used with equal ability to work on the same question package. One group uses the PBT model, and the other group uses CBT so that the response choices are obtained in each test model. The results of the respondent’s answer choices were then analyzed by the ITEMAN software to get the item difficulty index. The item difficulty index of each model was tested statistically using SPSS software, whether there was a significant average difference between the two test models. From the results of the study and analysis in classical theory, it can be concluded that statistically there are differences in the average difficulty index of the items if the same item is displayed with the PBT and CBT models. It was found that the items displayed with the PBT model had a more difficult tendency than when displayed with the CBT model.

Physics teachers’ training and professional development play a crucial role in preparing schools for the countless challenges they face. One of the central issues in the preparation of teachers is to provide them with tools, strategies, and methods to be able to build bridges between school and society, particularly to find fruitful links between formal, non-formal, and informal teaching, starting from primary school. In this paper, we report on some discussions developed during the Malta 2020 webinar by the Work Group 4 (WG4) participants, together with some questions and answers that emerged.

Pre-service physics teacher education is key in preparing prospective physics teachers to effectively support student learning and interest development alike. In order to do this, pre-service teachers must acquire, among other things, a profound teaching-oriented content knowledge and positive stance regarding teaching and motivation towards teaching. However, there are many more issues related to pre-service physics teacher education. In this paper, we report about some questions raised and answers proposed about this subject during the GIREP Malta 2020 Webinar Work Group 5 discussions.

The paper summarizes the results of discussion of the work group that focused on different aspects of experiments and laboratory work in teacher education. The discussion evolved around the following four guiding questions: What is the role of experiments in learning physics in general?; What are the labs supposed to help students learn?; How to achieve these goals in practice?; and How do we help future teachers develop skills/knowledge/competences so they will be successful in achieving these goals? About 30 participants shared their experience, views and ideas. The resulting views are summarized into general findings and recommendations.

Abstract.The measured spectral line based on frequency domain dielectric spectrum contains multiple superpositions of conductance and polarization processes. In view of the lack of methods to separate the polarization and the conductance processes and the lack of unique methods to characterize the model conductance parameters, the micro conductance processes are studied in depth according to the real and imaginary Kramers-Kronig relation. Firstly, different water content insulation samples were prepared during the laboratory conditions, and dielectric lines in frequency domain were obtained by measurement. Secondly, according to the k-K relation, the relaxation loss spectrum line is obtained by numerical integration of the measured real part of the complex polarization spectrum line, and then the conductivity loss spectrum line is obtained. Finally, the least square method is used to fit the conductivity spectrum line and calculate the conductivity value. The experimental results show that the conductance of the virtual part of the repolarization measurement can be separated from the relaxation loss line by k-K transformation, and the dc conductance can be calculated. At the same time,with the oil-paper insulating sample’s water content increasing, its electrical conductivity is gradually enhanced.

The waste Tetra pack impose a great pressure on environment. In this paper, we use hydrothermal liquefaction technique to convert it into valuable crude oil. The paper fibre and LDPE were studied in supercritical water at 420 °C, 25 MPa and residence time of 30 min. Effect of paper fibre: LDPE on the crude oil yield, components distribution and high heat value were investigated in depth. Results showed that maximum crude oil yield of 27.33 wt% was obtained at paper fibre to LDPE of 8:2, minimum O/C of 0.094 was obtained at paper fibre to LDPE of 5:5, which reflect that HTL of paper fibre and LDPE had a synergetic effect. And the highest high heat value of the crude oil reach 37.7 MJ/kg at the ratio of 5:5• The CH radicals produced from LDPE chain can promote the hydrogenation reaction that then decrease the production of oxygen-containing groups, and also the broken of C-C bond in lignin will be accelerate, which increased the diesel (C16-C47) compound.

Since cellulose is an important element for the production of tissue paper, many researchers used natural-based materials as an alternative in the manufacture of tissue paper so that it will be more environmentally friendly and safe to use for the community. Previous studies have found that cassava peel waste (57% cellulose) or durian peel (60-65%) each can be an alternative raw material for making tissues with quality does not differ much from tissue products in general. This study aims to determine the influence of durian peel and cassava peel mixture composition with a variation of mass ratio as 1:1; 1:1,5 ; 1:2 ; 1:2,5 ; 1:3 ; 1,5:1 ; 2:1 ; 2,5:1 ; 3:1. This research uses sodium hydroxide 10% for chemical pulping and bleached by 2% of hydrogen peroxide. Once the lignin has been rinsed out from the pulp, sheeting should be carried out by adding tapioca, chitosan and virgin coconut oil. Based on the test analysis and referring to SNI 0103:2008, the optimal composition of durian peel and cassava peel mixture is on the mass ratio of 3:1 which has a gramatur value of 41 g/m2, water absorption of 6.3cm, crushed resistance of 46 seconds and color does not fade, with a clean appearance, a little soft and not perforated so that it almost resembles tissues on the market, although it still has some stiffness to the surface.

To provide a reference for practical engineering application of fiber composite materials, this work researches on the impact resistance of type-B quartz fiber/modified cyanate ester composite material laminates and NOMEX paper honeycomb sandwich panels. Firstly, low-speed impact tests are carried out on the quartz fiber laminates and the NOMEX paper honeycomb sandwich panels by setting different parameters to analyze the impact energy and punch mass on impact damage; secondly, based on the experimental results, impact responses are analyzed; and the damage morphology of the two composite materials is observed through visual inspection and with the aid of the CT scanning technology. The results show that according to time-load curves, the NOMEX paper honeycomb sandwich panels have two peak load moments, respectively corresponding to the moments when the upper and lower panels are penetrated; the quartz fiber laminates show three different types of failures, namely substrate cracking, fiber fracture and delamination. As for the NOMEX paper honeycomb sandwich panels, two types of damage are found: fiber fracture and honeycomb core extrusion fracture. When the punch mass is constant, the greater the impact energy is, the more serious the damage is; and when the impact energy is constant, the greater the punch mass is, the more serious the damage is.

Before COVID-19, although the online assessment platform has developed, it is relatively slow, and people prefer to organize on-site examinations. After the outbreak of the epidemic, people realize the urgency and necessity of information construction in all walks of life. More and more researchers begin to pay attention to and explore the use of advanced machine learning methods to improve the practicability of online examinations platform. The test paper generation function is the core link, and a good test paper generation function can ensure the quality of a test paper. In this paper, an advanced unsupervised algorithm DPC(Clustering by Fast Search and Find of Density Peaks) is used to conduct deep mining and test paper generation adaptive based on the question bank and historical assessment such as assessment frequency, accuracy or score rate, and a more reasonable test paper generation function is realized. By comparing and testing the experimental results, it can be proved that the idea is correct and feasible.

The preparation of cellulose-based flame retardant paper treated with sodium silicate and silicon dioxide (SiO2) colloidal particle by simple immersion process is reported. Cellulose-based paper was preheated at 90°C for surface preparation. The heat treated paper was immersed in solution of sodium silicate-SiO2 at different immersion time ranging from 15 min to 24 hrs. Treated solution diffused into paper coated on the paper fiber and filled the void in the paper microstructure. Treated paper was heated at 90°C to convert an impregnated sodium silicate-SiO2 precursor into silicate framework. The treated paper showed Vsym Si-O-Si from siloxane bond at 792 cm-1 which confirmed a presence of SiO2 in paper. Treated paper at 1 hr immersion showed the highest weight percent gain (WPG) of 40% and total combustion time was improved to 14 sec.

The electrophysical characteristics of experimental types of electrical insulating paper modified by bacterial cellulose made of nano-gel film Komagataeibacter xylinus, disintegrated in various ways, were studied. The advantage of composites over traditional electrical insulating paper made of pine cellulose is shown in terms of electrical and mechanical strength, sorption activity and heat resistance. The efficiency of using an industrial blender to grind bacterial cellulose has been confirmed, which significantly reduces the time of its high-quality grinding.

As a new kind of paper-based textile materials and thanks to its healthiness and environmental protection, the paper yarn and its production will have a good future. This study mainly explores the papermaking process as follows: the beating degree of hemp pulp is 75°SR, the addition amount of PVA fiber, polyamide polyamine epichlorohydrin (PAE) and alkenone dimer (AKD) is 2.0%, 2.5% and, 0.2%, respectively. In addition, the pressure light pressure is 15 N/mm. The high hydrophobic paper yarn base paper has the wear resistance, water resistance, acid and alkali resistance. The analysis shows that the paper yarn base paper can be used as raw material in textile and weaving industries, thus reducing the use of viscose, polyester, plastic, etc.

In this article the discussion of Working Group 3 during the GIREP online seminar 2020 on teaching and learning quantum physics in teacher education is summarized. Conclusions are drawn and research desiderata formulated.

Hemp fire (Cannabis sativa) was delignified with the reaction mix “acetic acid - hydrogen peroxide - sulfuric acid catalyst - water” under sulfuric acid concentration of 0.45%, liquid module of 6, and temperature of 85 ° C. The cellulose was ground to 34 … 36°SHR and mixed in different ratios in compliance with the simplex-centroid experimental design with bleached sulfate softwood and hardwood pulp. The influence of the mixed composition formulations on the main strength properties of paper castings has been studied. It has been concluded that technical cellulose obtained from hemp fire applying this method, can be used for paper products manufacturing in combination with sulphate cellulose from coniferous and deciduous wood.

Borax is one of food additives that has been prohibited from being used by the Indonesian Government because it is dangerous to health. However, the fact is that borax has been widely added to several food products, such as skewered meatballs, school children’s snacks, bread, meatballs, tofu and crackers. Crackers containing borax is easily found in traditional markets. Short-term consumption of borax can cause various symptoms such as headache, fever, malaise, nausea or vomiting, pain in the upper abdomen and diarrhea. While long-term exposure to borax will have a more dangerous effect, which can cause stomach disorders, seizures to acute kidney failure which can lead to death. This paper reports a simple, easy and inexpensive test of borax content using a home-made turmeric paper on ten types of crackers purchased randomly in traditional market. The aim is that the borax content test can be carried out by anyone only by buying a few ingredients from the local market and pharmacy, and without the need to involve laboratory tests, but with accurate results when compared to laboratory tests. As a comparison, a flame test and a colour test on the borax content carried out in the laboratorium using the AOAC 18 ed. 2005 Official Method Boric Acid & Borates in Food 970.33 and the FI ed. V of 2014 General Identification Test Borat method A on Page 1423 was also completed. Among the 10 crackers tested, six of them were detected to contain borax. These results are very consistent with the laboratory test results. The performance of the home made turmeric paper is therefore reliable.

The paper presents an information system for calculating the main paper-forming parameters of the pulp for given technological and design parameters of the grinding plant. The operation of the system is based on mathematical regression models of the processes that were obtained in the course of experimental studies of knife sets of various types. As input parameters in these models, the rotor speed, knife gap, concentration and degree of grinding of the mass are used. The output parameters are the grinding time, water retention capacity and average fiber length. The developed information system is a network web application with a modular structure. The modules are united by the main interface for the user. Each module implements a regression model for a specific type of headset. At the moment, the system has two modules for calculating the parameters of a percussion type headset and a headset with a curvilinear shape of knives. In the future, it is planned to add the ability to calculate indicators for headsets of other designs. It will also add the ability to solve optimization problems by finding the minimum or maximum value of the output parameters.

Palm Oil Fly Ash (POFA) has been considered as a potential source of silica for paper filler. The objective of this work is to prepare a filler from the Palm Oil Fly Ash (POFA) to reduce disposal and waste problem. The extraction of silica from POFA can be carried out using solution of 5 M NaOH with ratio 1:5 (w/w, with respect to POFA), stirring speed of 600 rpm for 4 hours, resulting the 0.8770 M silica in Na2SiO3. The product is then reacted with Ca(OH)2 to produce paper filler (CaSiO3). The filler was characterized with Fourier Transform Infrared (FTIR), Scanning Electron Microscope-Energy Disperse X-Ray (SEM-EDX), X-ray Diffractometer (XRD) and Particle Size Analyzer (PSA). FTIR spectrum showed the formation of OH, C = O, Si-O-Ca and Si-O-Si functional groups, whereas the SEM-EDX analysis revealed the porous surface with the aggregation of needle-like morphology and contained five elements such as O (45,14%), Mg (0,85%), Si (15,65%), Ca (36,77%) and Al (1,59%). Meanwhile, XRD spectroscopy showed the presence of calcium silicate, calcite, vaterite, calcium hydroxide and quartz. Data from PSA analysis indicated that the filler has narrow particle size distribution compared with commercial fillers (GCC & PCC) and has small average particle size compared with PCC. The filler and the commercial counterparts were then applied as a paper simulation (hand sheet). Analysis of hand sheet showed that the presence of the synthetic filler in the hand sheet can improve brightness, opacity and bulk values, but slightly reduced in tensile and tearing index compared to that of PCC & GCC.

Paper artifacts are contaminated by external factors in the process of preservation such as foxing. For the problem of backward technology of rapid detection of foxing on paper artifacts, a method based on hyperspectral imaging technology is proposed to detect foxing spots on paper artifacts. After selecting the region of interest and obtaining the corresponding average reflectance, the difference in the average reflectance is found after comparing the healthy regions with the diseased regions. Using band operation and minimum noise fraction to observe the characteristics of foxing image, although there is overlap in different parts, the distribution distinction between moldy and healthy regions is obvious; K-nearest neighbor method and BP neural network are applied to establish the spectral discrimination model of paper artifacts with foxing spots, and the overall discrimination rate of the two methods is 73.3% and 85%, respectively. The results show that hyperspectral imaging can be used for the identification of foxing spots, but the distinction between different parts is not good, and the discrimination effect still needs to be improved.

In this manuscript, utilizing the controlled variable method, the three different profiles of thin paper with fixed ends are investigated. The results indicate that the specific profile of the paper depends on the length of the paper and the fixed distance between the sheets. Meanwhile, the mass of the paper has little effect on its profiles and so it can be ignored. Also, the symmetry-broken phenomenon about the thin paper is observed. Finally, according to the Principle of Least Action, it proposes a simple model to simulate the thin paper profiles