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The fibre characteristics of five Spondia mombin stands were studied to determine their suitability for pulp and paper production. Wood slivers obtained parallel to grain at three (3) different positions along the bole were macerated in combined identical amounts of glacial acetic acid plus hydrogen peroxide under heat at between 80-100o C. Macerated fibres were washed clean of mixture and mounted on slide for microscopic examination of fibre characteristics. Completely Randomized Design (CRD) was employed for the experiment. Data were analysed using one-way Analysis of Variance (ANOVA) while, the Duncan’s Multiple Range Test (DMRT) was used to separate means of significant differences among the treatments. Results show that significant differences existed in fibre characteristic of sampled trees, however the fibre length ranged from 0.98-1.0 mm, fibre diameter (18.22-21.47 um), lumen width (10.90-12.98 um) and cell wall thickness (3.86-4.60 um). Significant differences were also observed among the derived fibre characteristics, the Runkel ratio ranged from 0.66-8.89, elasticity coefficient (57.22-60.50 %), coefficient of rigidity (19.78-22.24 %), slenderness ratio (43.27-46.5). This implied that, the fibres of S. mombin were short and elastic which make the wood species an appropriate raw material for pulp and paper making especially when blended with other long fibre species.

The fiber of paper mulberry, which is mostly grown in the East Asian region, varies in both length and width—even if from the same species—depending on the country, soil, and climate where it is grown. This accounts for differences in the quality of handmade paper between domestic and imported products. Once handmade paper is manufactured as sheets, its origin cannot be determined from a morphological perspective, regardless of macroscopic and microscopic observations. Therefore, this study attempted to determine the origin of Korean and imported products using mulberry bast fiber and handmade paper from a chemometrics perspective. The inorganic components of wood are absorbed from the soil and exist in the bark of trees; thus, metal and rare-earth elements in the bast fibers and handmade papers were quantitatively analyzed using inductively coupled plasma-atomic emission spectroscopy/mass spectrometry (ICP-AES/MS). Following this, a prediction model of their origin was constructed by applying multivariate statistical analysis, i.e., a partial least squares-discriminant analysis (PLS-DA) loading plot was constructed, which helped in identifying the discrimination factors resulting from their origin. According to the ICP-AES results, Pb was only detected in the Gyeongbuk Mungyeong dak sample of the Korean bast fibers. The Chinese bast fiber sample had high contents of Ca, and B and Zn were detected only in the Chinese bast fiber samples. Bast fiber samples from China, Japan, and Thailand showed relatively high contents of Al, Ca, and Na. Meanwhile, Cu and Zn were detected in the handmade paper manufactured from the imported materials. According to the ICP-MS results, among the Korean handmade papers, the products from Gyeongbuk Mungyeong, Andong, and Chungbuk Goesan exhibited a high U content and that from Gapyeong had high Sc, Rb, Sr, and Ba contents. Thus, the elemental analysis employed in this study effectively identified the origin of the papers. The origin prediction by PLS-DA for the domestic and imported products revealed an accuracy of 86.4% and 72.7% for ICP-AES and ICP-MS methods, respectively, which is deemed acceptable to assess the origin. We believe this method significantly contributes to determining the origin of paper mulberry bast fiber and handmade paper manufactured in East Asia.

Perforation is used in multilayer tissue products, such as toilet and kitchen papers, as part of the converting process. Perforation facilitates the detachment of consecutive sheets by the user. The compromise between the strength required to detach a perforated sheet and the strength required to break a sheet affects the perforation efficiency. In this work, the mechanical behaviors of 15 commercial papers from different European producers were studied. A morphological analysis of the materials was performed, followed by the determination of their perforation efficiency (through tensile tests). A qualitative analysis of the cuts quality, along with a quantitative analysis of the same cuts dimensions was performed through an optical system. Finally, the stress concentration in the holes and the influence of the cuts distance were analyzed using a finite element model implemented in Abaqus/Standard finite element software. The results showed that a cut distance of 2.0 mm should not be used in these types of papers, and the perforation efficiency increased with the cut distance, regardless of the number of plies in the toilet paper. The stress concentration factor was also determined to have a limit value of 0.11. Papers above this limit value tear at the perforation line, as desired.

High demands for trees as the raw material of paper can disrupt the stability of the environment. It is necessary to find alternatives from other materials which are more environmentally friendly. This study aims to determine the quality of paper made from combining sugarcane bagasse with cassava peels or with corn husks using PVAc or tapioca starch adhesives. A completely randomized 2 x 2 factorial design with five times replication was used. The parameters tested were the tensile and tear resistance of the paper using a micrometer and a universal testing machine. A sensory analysis from panelists was also conducted. The combination of J1P1 produced a paper with the highest tensile strength (11.30 MPa) and the highest tear strength (1.82 MPa). The combination of J2P2 produced a paper with the lowest tensile strength (10.35 MPa) and the lowest tear strength (1.62 MPa). Variance analysis showed that the type of adhesive used showed a significant result on both tensile and tear resistance but material choices and interaction between materials and adhesive choices was not significantly different from the result on both tensile and tear resistance. Sensory testing shows that the combination of J1P1 was preferred the most. It can be concluded that the combination of J1P1 appeared to be the best combination.Keywords: Handmade paper, sugarcane bagasse, cassava peels, corn husk, PVAc tapioca starch, adhesive

In this study, we evaluated the effect of bamboo bleached kraft pulp (BKP) on the strength of the coloring paper used for pear paper bags. The characteristics of bamboo BKP were measured to compare them with those of softwood BKP and hardwood BKP. Handsheets from bamboo and hardwood BKPs were prepared at various mixing ratios, and their strengths were then analyzed. After that, a mill trial was performed to produce a prototype of coloring paper with bamboo BKP, and the effect of bamboo BKP on the strength of the coloring paper was finally determined. The initial freeness and fiber shape of bamboo BKP were similar to those of hardwood BKP, although the average fiber length and curl of bamboo BKP were higher than those of hardwood. As the mixing ratio of bamboo BKP increased, the strength of the handsheets increased, indicating the enhancing effect of bamboo BKP on the strength of coloring paper. As a result of the mill trial of coloring paper in the specialty paper mill, it was found that the tensile strength increased by 27.8% and burst strength by 20.0% when bamboo chemical pulp replaced 20% of the hardwood chemical pulp. Therefore, it was concluded that bamboo chemical pulp can replace and improve the strength of hardwood chemical pulp for manufacturing coloring paper.

This research is an analysis of quality control process on paper production on the soft roll production process of Bel Papyrus Ltd located in Ogba, Lagos State, Nigeria. The research was done with the aim of determining the conformity of the industry’s product to quality standard, identifying and eliminating the possible causes of variation in their production process, with reference to Percentage Elongation. The researchers used primary data in form of periodic laboratory test result done on soft rolls.Data presentations were made using simple statistical tools like Mean, Ranges, Standard Deviations, and Tables reflecting the primary data obtained at equal interval of production. The researchers made use of variable control charts for the purpose of analysis. The

Our dependency towards wood has reduced the number of forests especially in Indonesia. Hence, many people tried to use another material as a replacement of wood. One of them is composite. Department of Industrial Engineering Universitas Sebelas Maret has developed paper-based composite using newspaper waste in Praktikum Perancangan Teknik Industri (PPTI) II. Unfortunately, the quality of composite is not so good. This paper tried to understand the effect of factors to responses and discover the best combination of factors to obtain the best responses. The responses of this experiment are tensile strength, bending strength and impact value. The factors of this experiment are paper pulp, PVAc glue and water. Taguchi method is used to find the appropriate orthogonal array and Particle Swarm Optimization method to find the optimum combination of the factors. Orthogonal array used in this experiment is L9 (34). Through analysis, all of the factors are significant to tensile and bending strength, but they are not significant to impact value. The best combination of factors is 175 grams paper pulp, 130 grams PVAc glue and 175 ml water. Optimum results obtained for tensile strength is 0.7595 N/mm2, bending strength is 4.873 N/mm2 and impact value is 0.0138 J/mm2.

In China, Xuan paper has been the paper of choice as artwork support and for conservation, for several centuries. However, little is known about its material properties, especially given the many grades of sized and unsized Xuan paper. In addition, there is a lack of information on its degradation. In this research, a selection of contemporary unsized Xuan papers was investigated, representing diverse raw materials. Seven out of twelve contemporary unsized Xuan papers were determined to be approximately neutral and contain > 2% alkaline reserve, indicating good durability. Viscometry was used to determine the degree of polymerisation (DP) as none of the samples gave significant reactions to the phloroglucinol spot test. The average DP of ten contemporary unsized Xuan papers is ~ 1700, excluding two papers that have presumably been sun-bleached, and that exhibit significantly lower DP. Using X-ray fluorescence, it can be demonstrated that Ca and Si are the dominant elements and interestingly, Ca content is directly correlated with ash content and with alkaline reserve. Accelerated degradation was performed at two sets of environmental conditions, i.e. 90 °C, 30% RH and 60 °C, 70% RH, and the established degradation rates agreed with the Collections Demography model of paper degradation meaning that degradation of Xuan papers proceeds in the same way as other types of paper. This research gives fundamental insights into contemporary unsized Xuan papers, which exhibit good stability during accelerated degradation despite the low starting DP in the context of the samples used in this study. Our findings may inform methods of Xuan paper production, selection of Xuan paper for conservation purposes, as well as preventive conservation of Xuan paper-based artefacts.

Uzbekistan is bare of forests and it takes the fifth place in the world in terms of cotton production, and the third place in terms of silk production after China and India. According to the government program the expansion of the land area for mulberry plantations boosts the growth of silk production causing an increase in the total amount of wastes, i.e. branches of mulberry trees industrially useless after the removal of leaves. Their use as a raw material for the cellulose pulp production is relevant, since it is aimed at solving not only the resource, but also the environmental problem. The bark was cut off from the mulberry branches and soaked in water for some time after which its exterior hard layer was scraped off and divided into the rough exterior layer and the softer inner layer. The inner layer was boiled for several hours. The boiled bast, after washing with water, was grinded in a laboratory grinding machine under the following conditions: mass concentration – 1 %, temperature – 22 °С. A given amount of lint cotton cellulose (grinding degree – 45 °SR) was added to the grinded bast. Paper molds with the mass of 80 g/m2 were obtained in laboratory conditions using a sheet-making apparatus. It was found out that the obtained paper that contains cotton cellulose pulp and inner layer of mulberry branch bark has low whiteness which depends on whiteness of the added fibers. It has been established that adding the cellulose pulp of the inner layer of mulberry branch bark at a grinding degree of 30 °SR contributes to the production of strong paper. It is recommended to add up to 30 % of cellulose pulp from the inner layer of mulberry branch bark to paper pulp as further addition adversely affects the paper whiteness.For citation: Babakhanova Kh.A., Galimova Z.K., Abdunazarov M.M., Ismailov I.I. Cellulose Pulp from Mulberry Branch Bark for the Paper Industry. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 5, pp. 193–200. DOI: 10.37482/0536-1036-2020-5-193-200

Objectives: The objective of the study was to study the compressive strength of the partially replaced paper mill waste in cement. Methods/ Statistical analysis: The concrete cube specimen were prepared for compressive strength test. In this study, the cement has been replaced with 20%, 30%, 40% and 50% of hypo sludge. The specimens were cured for two different ages (7 days and 28 days) and tested for compressive strength. The quadratic polynomial prediction equation was proposed using Response Surface Methodology (RSM). The prediction model was developed using the experimental output results. Thus, the prediction model facilitates the further research work to be conducted by researchers on paper mill waste replacement. The rate analysis was also further carried out to show the cost effectiveness of using the waste replacement in cement. Findings: The test was conducted on the compressive strength (7 days and 28 days) of control specimen (0%) and partial replacement of 20%, 30%, 40% and 50% of cement using the hypo sludge. Thus, 20% replacement of cement using hypo sludge has shown good compressive strength than the control specimen. The cost of 20% paper mill waste was less when compared to the cost of control specimen. Novelty/ Applications: The compressive strength of 20% partial replacement of paper mill waste in cement can be used in further construction. The prediction model can be used to predict the future compressive strength of partially replaced paper mill waste concrete. Keywords: Ordinary Portland cement; Paper mill waste; Hypo sludge; Partial replacement; RSM

Based on publications related to the use of micro- and nanofibrillated cellulose (MNFC) in papermaking applications, three sets of parameters (intrinsic and extrinsic variables, furnish composition, and degree of dispersion) were proposed. This holistic approach intends to facilitate understanding and manipulation of the main factors describing the colloidal behavior in systems comprising of MNFC, pulp fibers, and additives, which directly impact paper product performance. A preliminary techno-economic assessment showed that cost reductions driven by the addition of MNFC in paper furnishes could be as high as USD 149 per ton of fiber (up to 20% fiber reduction without adverse effects on paper’s strength) depending on the cost of papermaking fibers. It was also determined that better performance in terms of strength development associated with a higher degree of MNFC fibrillation offset its high manufacturing cost. However, there is a limit from which additional fibrillation does not seem to contribute to further strength gains that can justify the increasing production cost. Further research is needed regarding raw materials, degree of fibrillation, and combination with polyelectrolytes to further explore the potential of MNFC for the reduction of weight of paper products.

The utilization of branchwood as lignocellulosic raw material source for paper production may have the potential of solving the problem of the availability of raw material in the pulp and paper industry. This study therefore compared the chemical composition and fiber morphological indices (according to Franklin’s method) of stemwood and branchwood in Eucalyptus camaldulensis and Pinus halepensis trees grown in Egypt. The statistical analysis showed a significant effect of species, wood type (stem and branchwood), and their interaction on the measured chemical constituents and fiber morphological indices at 0.05 significance level. In both genera, the stemwood exhibited a higher percentage of cellulose and hemicellulose and was lower in lignin, total extractives, and ash than those measured in branchwood. Also in both genera, the stemwood was higher in fiber length, Runkel ratio, rigidity coefficient, Muhlsteph ratio, and Luce’s shape factor, and lower in basic density and flexibility coefficient than those in branchwood. Based on the chemical analysis and the fiber morphological indices, the stemwood and branchwood of both species were suitable for paper production with various qualities. Moreover, good correlations were found in both stem and branchwood between the basic density and the fiber wall thickness and fiber lumen diameter. ln contrast, there was an independent association between the stemwood basic density and the fiber length, and this relationship in branchwood was positive for both genera.

This study is aimed at exploring the writing ability improvement process of g roup B students in TK Nursa and investigating to what extend the processing result of writing ability can be improved through sand paper alphabet . This study was a classroom action research using Kemmis and Mc. Taggart research model. This study was conducted in 2 cycles with 6 meetings in each cycle where every cycle consisted of the following steps: planning, action and observation, reflection. The sample of this study was 1 2 Group B students comprissing of 5 male students and 7 female students. The instruments used in this study was observational sheet of students activities using sand paper alphabet . The data in this study were quantitative and qualitative data. Quantitative data were analyzed by using descriptive statistic to compare the result from the first and second cycle. While qualitative data from field notes and interview were analyzed through the following steps: data reduction, data display and data verification. The results of this study show that there is the improvement of writing ability through sand paper alphabet , proven by the writing ability mean score in pre-cycle which was 50,17 % improve to 67,15 % in cycle I and keep increasing becoming 76,04 % in cycle II.

Chemical medicine which are synthetic chemicals or isolation products must not be added to herbal medicine, that was standared by Indonesian Head of the Drug and Food Control Agency in statement regarding Criteria and Procedure for Registration of Traditional Medicines, Standardized Herbal Medicines, and Phytofarmaka. This study aims to develope prototype of paper-based color test-strip to identify paracetamol trace in several types of Indonesian herbal medicine, better known as Jamu. Research conducted with experimental research wich make paper test-strip prototype by immobilizing reagents into Whatman’s filter paper, then it used to identify paracetamol in extracted Jamu samples. The paracetamol qualitative test uses 10 Jamu samples that distributed in Samarinda area. were also carried out on. Comparison methode with qualitative color reaction tests using specific reagents in the laboratory were also carried out beside the paper-based color test-strip methode. In addition with positive control tests using 5000 ppm paracetamol solution to make sure both methode used are valid. The results of this study showed that two prototype paper-based color test-strips containing 10% iron (III) chloride reagent and folin ciocalteu were able to detect the presence of paracetamol chemicals in Jamu samples with color reaction.

This study aims to predict financial distress in pulp and paper companies in Indonesia. The data used are the financial statements of each pul and paper company listed on the Indonesia Stock Exchange in 2012-2017. Data analysis techniques used descriptive analysis with three methods of financial distress prediction, namely the Altman Z-Score, Springate, and Zmijewski methods. The results showed that the Zmijewski method is a prediction method with the highest accuracy rate of 100%, with an error type of 0%. The Altman Z-Score method has an accuracy rate of 28.6%, with an error type of 71.4%. While the Springate method has an accuracy rate of 14.3%, with an error type of 85.7%. Therefore an accurate prediction method to predict the potential for financial distress is the Zmijewski method.

In this study, it is aimed to determine the most suitable time series models with Box-Jenkins method, which is the most widely used in prediction studies. Export and import values have been predicted by 2020 with the most suitable models. The data used in this study were obtained from the Turkey Statistical Institute. Data are monthly data covering from January 2003 to December 2014. Sum of Squared Errors (SSE) and Mean Squared Error (MSE) criteria were taken into consideration when selecting the best Box-Jenkins models. Also, in order to test the success of forecasting of the models, Root mean Error Square (RMSE), Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE) were used. As a result of the analyzes, it was determined that the most suitable models for export and import data were ARIMA (2,1,0) (0,0,1)12 and ARIMA(3,1,2)(1,0,1)12. It was predicted that the rate of exports meeting imports in paper and paper products of Turkey will be approximately 0.86 in 2020.

This study evaluated the fibre morphology of Musa balbisiana leaf, stalk and stem portions for pulp and paper production. Samples of Musa balbisiana portions were prepared and macerated in equal volume of glacial acetic acid and hydrogen peroxide in ratio 1:1. Twenty cellulose fibres from each portion were randomly selected using Reichert visopan microscope to determine the physical fibre morphology while the derived fibre indices were calculated. Data collected were subjected to one way Analysis of Variance (ANOVA). Follow up tests carried out using Duncan Multiple Range Test (DMRT). Results showed that means of fibre length, fibre diameter, cell wall thickness and lumen width ranged between 1.35 and 2.46 mm, 16.46 and 33.34 µm, 7.58 and 24.99 µm, and 3.54 and 3.56 µm, respectively. The mean values of fibre length of Musa balbisiana leaf and stalk were not significant but were significantly different from the mean values of the stem at p

Borassus flabellifer L., one of the palm-based commodities in Indonesia which is grows in dry areas especially around the north coast of Java Island. An abundant waste of this plant is a leaf midrib and fruit fiber have an opportunity as a source of lignocellulose for the paper industry. In this study, Kraft paper production was conducted to know the influence of the proportion of Borassus flabellifer L. leaf midrib pulp and fruit fiber pulp, and the concentration of Polyvinyl Acetate (PVAc) adhesives on the sensory and physical quality of kraft paper. The research method used was Randomized Block Design (RBD) with two factors. The Friedman test was used to determine the sensory quality of kraft paper. The physical quality of kraft paper was used ANOVA analysis. 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 not significantly different between treatment of gramature and tear resistance. The best treatment of sensory tests was kraft paper with proportion of leaf midrib pulp 50% and fruit fiber pulp 50% and a 7.5% PVAc adhesive concentration. It has a yield value of 72.11%, gramature of 162.80 g/m2, tensile strength of 1.70 %, and tear resistance of 197.6 gf.

The article analyzes the separation of fats from paper waste packaging. The method is based on interaction with boiling water and greaseproof paper. The cooking process is considered the formation of emulsions according to different slots. The research data are presented and discussed obtained from the analysis of ready-made samples. 20 different fat-coated paper samples have been prapared for research. Ten of them have been selected for printing paper, and another dozen cartons. The half of the samples analyzed are covered with vegetable fat, the remaining samples are vegetable fat. It was found that the carton samples were less opposed to the separation of fat. During the experiment, it was determined that by cooking the cardboard samples coated with olive oil for 5 minutes, 30% of the total fat content was removed. The most effective samples of this type were heated for a long time. Santrauka Straipsnyje nagrinėjamas riebalų atskyrimas nuo popieriaus pakuočių atliekų. Metodas remiasi verdančio vandens ir riebalų sąveika su suterštu popieriumi. Nagrinėjamas virimo procesas, emulsijų susidarymas atsižvelgiant į skirtingus laiko tarpsnius. Pateikiami ir aptariami tyrimų duomenys, kurie gauti išnagrinėjus pasiruoštus mėginius. Iš viso pasiruošta 20 skirtingų riebalais padengto popieriauspavyzdžių. Dešimčiai iš jų pasirinktas spausdinimo popierius, kita dešimtis– kartonas. Pusė analizuojamų mėginių padengti augalinių riebalų sluoksniu, likę mėginiai– gyvulinių riebalų sluoksniu. Pastebėta, kad kartono mėginiai mažiau priešinosi riebalų atskyrimui. Nustatyta, kad, 5 min. virinant kartono mėginius, padengtus alyvuogių aliejumi, pasišalino 30% viso riebalų kiekio. Efektyviausia tokio tipo mėginius virti ilgą laiką, nes, panardinus mėginius 15 min. į verdantį vandenį, pasišalino daugiau nei pusė buvusių riebalų kiekio– 55%. Reikšminiai žodžiai:atliekos, emulsija, popierius, popieriaus pakuotės, riebalai, šiluma, vanduo, virimas.

This research work deals with modification of the color of paper in commercial clupak dynamic image registration. According to the standard technology of production of kraft pulp, from which the production clupak paper, the paper obtained is dark brown in color. Market demand is based on quality and price of the product. Step further in these demands is demand for certain balanced and brighter shade of color of sack kraft paper. Lately it is demanded from our company to produce sack kraft paper with lighter shade of color. This problem can be solved in two ways: by coloring pulp fiber and by bleaching it. Methods of production of sack kraft paper with lighter shade, as well as results achieved, will be presented in this document.

The aim of this study was to assess postures and movements of the trunk and upper arm during paper mill work, and to determine the extent to which they differ depending on method of assessment. For each of 28 paper mill workers, postures and movements were assessed during three full shifts using inclinometer registration and observation from video. Summary metrics for each shift, e.g., 10th, 50th, and 90th posture percentile, were averaged across shifts and across workers. In addition, the standard deviation between workers, and the standard deviation between shifts within worker were computed. The results showed that trunk and arm postures during paper mill work were similar to other occupations involving manual materials handling, but the velocities of arm movements were lower. While postures determined by inclinometry and observation were similar on a group level, substantial differences were found between results obtained by the two methods for individual workers, particularly for extreme postures. Thus, measurements by either method on individuals or small groups should be interpreted with caution.

Wood-processing industries must be able to estimate the properties of wood to properly manage the wood production chain. For this estimation, changes in certain characteristics over time must be identified so that they can be used to rapidly differentiate a clone or species. Of interest are acoustical, geometrical, physical, and mechanical properties, all measurable in seedlings. Thus, the objective of this research was to analyze the evolution of the ultrasonic wave propagation velocity, diameter, height, basic density, strength, and stiffness starting in nursery seedlings at 3 months of age to trees at 6 years of age, which is the cutting age used by the pulp and paper industry in Brazil. The experiment was conducted in 121 seedlings and 270 trees of three Eucalyptus clones. Within the age range analyzed, the results indicated that all parameters have the potential to be used in a predictive model to estimate the future quality of clones, although the predictive value of these parameters varies. The ultrasonic wave propagation velocity was the only property that maintained the coherent differences among clones from the seedling to the cutting age (6 yr old). The strength, stiffness, diameter, and height maintained coherence from 12 months to the cutting age, whereas the basic density was maintained from the age of 24 months to the cutting age. We hope that these results will contribute to improving the methods to select clones.

A classical result of K. L. Chung and W. Feller deals with the partial sums S k S_k arising in a fair coin-tossing game. If N n N_n is the number of “positive” terms among S 1 S_1 , S 2 S_2 , …, S n S_n then the quantity P ( N 2 n = 2 r ) P(N_{2n} = 2r) takes an elegant form. We lift the restriction on an even number of tosses and give a simple expression for P ( N 2 n + 1 = r ) P(N_{2n+1} = r) , r = 0 r = 0 , 1 1 , 2 2 , …, 2 n + 1 2n+1 . We get to this ansatz by adaptating the Feynman–Kac methodology.

Although replaced by the internet-based TOEFL (iBT), the paper-based TOEFL (PBT) was still used in some countries until July 2017. This natural experiment investigates a case where, November 2006–May 2009, a testing center in the Middle East did not follow TOEFL time interval protocol at that time, with 1,575 test takers allowed to attempt paper TOEFL versions as frequently as desired. This study analyzes score increase/decrease with frequency of/time intervals between attempts at taking paper TOEFL version(s). These test takers attempted the TOEFL multiple times, with 48% taking it at least twice, some up to 22 times. Results indicate a negative relationship between number of attempts and score increases/decreases between consecutive tests greater than Standard Error of Measurement (>SEM), and a positive relationship between score change and average time interval. Score decreases showed greater variability, with smaller average time interval than increases. Percentages of individuals’ score decrease averaged in repeater group positively correlated with number of attempts. Consecutive test scores decreased (>SEM) at least once for 900 test takers. Score decreases showed greater variability and significantly smaller average time intervals than increases. There was very strong positive correlation between increase in number of attempts and consecutive score decreases. Repetitions within one week showed greater score variations. These findings raise questions about construct-irrelevant effects of test repetition and time interval on score change. One explanation is that score increases >SEM occurred gradually over more time, in smaller amounts, in keeping with increases in ability through learning, but decreases >SEM occurred in shorter time intervals and larger amounts, possibly reflecting more immediate negative affect-related factors.

Aim of study: It was aimed to rank financial performance of companies in the paper industrytraded at BIST.Material and methods: The financial performances of sevencompanies in the paper industry which are tradedon the Borsa İstanbul (BIST) were determinedby using financial data in 2016. For this purpose, ten financial ratios were obtainedfrom the financial data of companies, each of which had its own superiority. The datawere conducted by the TOPSIS (Technique for Order Preference by Similarity toIdeal Solution) method which is the "Multi Criteria Decision Making"(MCDM) method to interpret.Main results: The results indicated that the companies were rankedfollows; ALKA, KARTN, VKING, BAKAB, TIRE, OLMIP and KAPLM based on thefinancial performance scores.Research highlights: In Turkey, production in paper industry meets nearly half of the consumption and paper demand are met by imports.The high prices of energy and initial investment costs encourage imports ofpaper products and they prevent newinvestments. From this perspective, growth, development and high performance ofpaper companies will keep this industry alive., BİST’deişlem gören kağıt sektöründeki firmaların TOPSIS yöntemiyle finansalperformanslarının değerlendirilmesiÖzetÇalışmanın amacı: BİST’de işlem gören kağıtsektöründeki firmaların finansal performanslarına göre sıralanmasıamaçlanmıştır.Materyal ve yöntem: Borsa İstanbul’da (BIST) işlemgören kağıt sektöründeki 7 firmanın 2016 yılına ait verileri kullanılarakfinansal performansları belirlenmeye çalışılmıştır. Bu amaçla, şirketlere aitfinansal verilerden 10 finansal oran elde edilmiştir ve bu finansal oranlarınher biri diğerlerine göre üstünlüğe sahiptir. Bütünleşik bir değerlendirmeyapılması amacıyla, veriler “Çok Kriterli Karar Verme” (ÇKKV) yöntemlerindenolan TOPSIS (Technique for Order Preference by Similarity to Ideal Solution)yöntemi ile değerlendirilmiştir.Sonuçlar: Şirketler finansal performanslarına göreALKA, KARTN, VKING, BAKAB, TIRE, OLMIP ve KAPLM olarak sıralanmıştır..Araştırma vurguları: Ülkemiz kağıt sektöründegerçekleştirilen üretim ile tüketimin yarısı karşılanabilmekte ve kağıtihtiyacı ithalatla karşılanmaktadır. Enerji fiyatlarının ve ilk yatırımmaliyetlerinin yüksek olması yeni yatırımları engellerken ithalata teşviketmektedir. Bu bakımdan sektörde var olan firmaların gelişmesi, büyümesi veperformanslarının yüksek olması sektörü canlı tutacaktır.

The paper presents the study results of paper trapping during inkjet printing which contains cellulose pulp from the inner bark layer of mulberry branches. The connection between the print density and the paper surface structure, in particular, water absorption and raggedness, is established. The study of the stepwise gradation transition and color rendition, the graphic accuracy of reproduction of the slur element of the image is carried out. Densitometric and microscopic analysis of the impressions printed on an inkjet printer was performed. It was revealed that the pigments of water ink, depending on the microgeometry of the paper surface, penetrated deeper in different ways. It was found that the maximum thickness of the paint layer, expressed using the optical density values for the primary colors of the subtractive synthesis, and the best color reproduction were provided by the surface of the paper sample with 100 % addition of cellulose pulp from the inner layer of the bark of mulberry tree branches, which has the least roughness, according to the scanning probe microscope Solver HV. Recommendations are given for testing paper data on inkjet printers that use pigment inks and are less demanding on the surface properties of paper, or by printing methods that do not use low-viscosity printing inks.

Wood is used as the major raw material in paper production around the world and this has resulted in severe deforestations having direct negative impact on our environment. This has led to the need of finding alternative raw materials for paper production. Mauritius has around 300 ha of land under pineapple cultivation resulting in agro-waste materials of the leaves. This paper aims at determining the feasibility of using pineapple leaf fibres for paper production. Samples of pineapple leaf fibre were mixed with cane-bagasse in different ratios namely, 20:80, 40:60, 60:40, 80:20,100:0. Pineapple leaf fibres were also mixed with wastepaper in the same ratios. Pulping of pineapple leaf was achieved through soda pulping at a concentration of 15%w/v for 90 min at 90 °C. The papers obtained were tested for their physical and mechanical properties. The average thickness of all the papers produced, ranged from 0.232 mm to 0.304 mm showing an increase in paper thickness with increasing grammage from 58.19 g/m2 to 63.3 g/m2. The most absorbent paper(1.19 s) was found to be the 100% pineapple which also demonstrated the highest Tensile Index and Burst Index (6.5 Nm/g and 0.84 kPa m2/g respectively). The bagasse and pineapple composite of ratio 40:60 was found to be the most abrasion resistant paper with 21 turns and a weight loss of 0.86% with the use of emery paper of grade zero as abradant and 200 g load cells. The most crease resistant paper was the wastepaper and pineapple composite of ratio 80:20 with a crease recovery angle of 59.8°.

In museum lighting, Chinese paper cultural relics are prone to cracking, embrittlement and other photochemical damage after absorbing the spectral energy of light sources. Owing to the different absorption and reflection characteristics of paper for different bands, optimizing the spectrum compositions of light sources can provide effective protection, the basis of which is to clarify the influence rule of spectra on the paper. However, the methods of color difference and Raman spectroscopy, which are widely used in the current research, cannot scientifically measure the lighting damage. In this study, Fourier transform infrared spectroscopy was used as the evaluation method, and 10 kinds of narrow-band lights were used as the experimental light source to conduct a 1440 h irradiation experiment on the samples of the ancient Chinese Xuan paper. The oxidation index was calculated as the evaluation index based on the infrared spectra measured every 240 hours, and a mathematical model for the response rate of paper to spectrum and exposure was established. 610 spectra were obtained with the 10 kinds of narrow-band lights combined and superimposed. The color rendering indexes of the above spectra were calculated, and 9,477 spectra that meet the requirements of viewing indicators were obtained. By calculating the damage degree of the above spectra with the model, the optimal LED spectrum with the minimum damage which met the visual requirements was obtained. Then it was input into the 10-channel spectral simulation system for spectral restoration. Two kinds of lights commonly used in lighting for paper cultural relics were selected to conduct a comparative experiment. The results showed that the optimal LED spectrum reduced damage degree by 49.4% and 59.7% respectively compared with the two kinds of contrast light sources, and was beneficial to energy saving.

Purpose This paper aims to measure the state-level energy efficiency in Indian paper industry and simultaneously explain inter-state variation in efficiency by inefficiency effect model. Three variables, labor productivity, capital intensity and structure of paper industry, are included in inefficiency effect model to assess the likely impact on energy efficiency. Design/methodology/approach Sub-vector input distance function is derived through neo-classical production function which provides measures to estimate energy efficiency. Assuming a translog production function specification, energy efficiency is estimated by using Battese and Coelli (1995) stochastic frontier analysis (SFA). The authors also estimated four other SFA models, and energy efficiency from all the models is compared for robustness checking. Findings The results show the existence of a vast potential to improve energy efficiency. Inefficiency effect model reported a positive impact of structure of the industry and capital intensity on energy efficiency performance, while labor productivity does not have any significant impact on energy efficiency. There exists considerable energy efficiency variation among states. Uttarakhand, Punjab and Orissa are the best performing states while Rajasthan, Jharkhand and Goa have worst energy efficiency performance based on average efficiency. The ranks assigned to states according to inefficiency effects model are found contrary to the simple measure of energy efficiency, i.e. energy intensity. Thus, energy intensity may not always be a good proxy for underlying energy efficiency and need to be compared with a comprehensive possible measure. Originality/value To the best of the authors’ knowledge, this is the first study which measures energy efficiency of Indian paper industry through stochastic frontier model using region-level data. Instead of relying on traditional energy efficiency indicators (energy-output ratio), total-factor energy efficiency approach is used to conduct the empirical exercise. Deviations from the frontier because of factors beyond the scope of producers are also incorporated into analysis to portray the magnitude of random factors in influencing the efficiency performance.

Purpose This study aims to examine the colour changes affecting inkjet prints after the recycling of papers. Design/methodology/approach For recycling, papers prepared with the INGEDE 11p standard are recycled four times. Pulping, storage, flotation, beating and bleaching processes are applied for each recycling, respectively. Inkjet prints are made on the obtained test papers, and colour measurements are made using an X-Rite eXact spectrophotometer according to the ISO 13655:2017 standard. These processes are applied again to the papers which are recycled four times, and the results are analyzed. In addition, the values of ΔE00 ′, ΔL′, ΔH ′ and ΔC′ are calculated according to ISO 11664-6:2014 standard by making some calculations according to obtained the L′a′b′ values. Findings It is determined that the ΔE00 value increases after each recycling in cyan magenta and yellow colour, whereas it decreases in black. The highest ΔE00 value is calculated after the fourth recycling stage is yellow with a value of 8.33. The lowest ΔE00 value detected is black with a value of 0.76 after the fourth recycling stage. This paper observes that the colour with the most variation in hue angle among recycling repetitions is black and the colour with the highest hue angle value is yellow. It is seen that repeating recycling causes increase in the chromatic values of the prints. Originality/value After the fourth recycling stage, colour changes have reached an important point and can cause important printing problems. In this case, the customer’s approval must be obtained to continue printing. This case is valid for ΔE00 values. Colour differences for print contrast, trapping and print chroma values are either not very important or are positive for quality.

Does the materiality of a three-dimensional model have an effect on how this model operates in an exploratory way, how it prompts discovery of new mathematical results? Material mathematical models were produced and used during the second half of the nineteenth century, visualizing mathematical objects, such as curves and surfaces—and these were produced from a variety of materials: paper, cardboard, plaster, strings, wood. However, the question, whether their materiality influenced the status of these models—considered as exploratory, technical, or representational—was hardly touched upon. This article aims to approach this question by investigating two case studies: Beltrami’s paper models vs. Dyck’s plaster ones of the hyperbolic plane; and Chisini’s string models of braids vs. Artin’s and Moishezon’s algebraization of these braids. These two case studies indicate that materiality might have a decisive role in how the model was taken into account mathematically: either as an exploratory or rather as a technical or pedagogical object.

The Corona pandemic that the world is experiencing is one of the most prominent global disasters today, and has become the subject of great interest from all countries of the world, especially since its effects were not limited to the health aspect only, but extended to the economic, legal, political and social aspect in the lives of individuals, which has resulted in countries entering into conflict with this pandemic by taking a set of preventive measures to combat its spread, and perhaps the most important of these decisions was the imposition of home quarantine on citizens and forcing social distance, in addition to terminating many commercial activities, , which leads to make the implementation of commitments almost impossible. This research aims at determining the legal nature of the Corona pandemic, and whether it can be considered as a force majeure, or is it just an emergency? What is the impact of this pandemic on the deadline for submitting commercial papers for acceptance and fulfillment? Is the legal holder of the commercial transfer, who was not able to submit it for acceptance and fulfillment within the deadlines, considered a negligent holder? Or force majeure can apply here?

In this paper, we first generalize to any hyper-Kahler manifold X with $$b_3(X)\not =0$$ results proved by O’Grady for hyper-Kahler manifolds of generalized Kummer type. In the second part, we restrict to hyper-Kahler manifolds of generalized Kummer type and prove, using results of Markman, that their Kuga–Satake correspondence is algebraic.

“Real Normed Algebras Revisited,” the last paper of the late Gadi Moran, attempts to reconstruct the discovery of the complex numbers, the quaternions, and the octonions, as well as proofs of their...

We show that a smooth embedded paper Moebius band must have aspect ratio at least $$\begin{aligned}\lambda _1= \frac{2 \sqrt{4-2 \sqrt{3}}+4}{\root 4 \of {3} \sqrt{2}+2 \sqrt{2 \sqrt{3}-3}} =1.69497\ldots \end{aligned}$$ This bound comes more than 3/4 of the way from the old known bound of $$\pi /2=1.5708\ldots $$ to the conjectured bound of $$\sqrt{3} = 1.732\ldots $$

Using standardized tests such as paper-based TOEFL with three subtests for classroom assessment is restricted by the length of the test, which is usually longer than the class duration. Therefore, it is significant to be able to predict other subtests by conducting only one subtest. Therefore, the current study aimed to calculate prediction coefficients, enabling teachers to predict scores in paper-based TOEFL by conducting only one subtest. The data to create the prediction models were obtained from 2,030 scores of Institutional TOEFL, i.e. paper-based TOEFL without writing subtest. The prediction coefficient was calculated by using linear regression analysis. The result shows that the listening comprehension sub-score predicts the TOEFL score more accurately (MSE of 520) than other sub-scores (MSE of 553 and 587). The intercept for listening comprehension sub-score was 373.07, 357.14 for structure & written expression, and 364.19 for reading comprehension. In addition, the slope for each sub-score was 4.07, 5.96, and 4.63, respectively. Therefore, a listening test should be used in predicting the overall TOEFL scores for an accurate prediction.

The five papers published by Hodgkin and Huxley in 1952 are seminal works in the field of physiology, earning their authors the Nobel Prize in 1963 and ushering in the era of membrane biophysics. The papers present a considerable challenge to the novice student, but this has been partly allayed by recent publications that have updated the reporting of current and voltage to reflect the modern convention and two books that describe the contents of the papers in detail. A disadvantage is that these guides contain hundreds of pages, requiring considerable time and energy on behalf of the reader. We present a concise guide to the Hodgkin and Huxley papers that includes only essential content, with the data presented in a linear and logical manner. We have color-coded figures for ease of understanding and included boxes that summarize key information for easy reference. It is our expectation that this article will act as an accessible introduction for students to the work of Hodgkin and Huxley and hopefully foster an appreciation for a fascinating story that repays in-depth study.

The widespread availability of banana pseudo stems which do not have considerable commercial value in the country presents a potential source of non-wood raw material for paper production. This investigation determined the suitability of using banana fiber for wrapping paper production. Banana fiber was used with sugarcane bagasse and wastepaper to produce paper in 20:80, 40:60, 60:40 and 80:20 ratios. Banana and sugarcane bagasse were chemically pulped using 12% NaOH and 4% Na2S for 1.5 h. The mean thickness of the papers were 0.263 ± 0.04 mm. 100% banana paper and 100% bagasse paper showed nearly similar water absorbency (2.15 s and 2.17 s) and were 2.25 times more than paper from 100% wastepaper. Highest tensile index was evidenced by banana paper with 20% wastepaper (29.4 Nm/g). For banana-bagasse mix-ratios, 20% bagasse demonstrated highest tensile index (16.04 Nm/g). 100% banana paper produced a tensile index of 18.97 Nm/g. Highest bursting index was from banana paper with 20% wastepaper mix (2.00 kPa m2/g). For banana-bagasse mix-ratios, 20% bagasse addition showed the greatest bursting index (0.88 kPa m2/g). 100% banana paper produced a burst index of 1.05 kPa m2/g. Highest abrasion resistance was 180 turns which was demonstrated by 100% banana paper. 20% mix bagasse and 20% mix wastepaper demonstrated the greatest abrasion resistance with 136 turns and 120 turns respectively. 20 40% of wastepaper (5.4 5.8% weight loss) and 10 30% bagasse (10.0 15.5% weight loss) were categorised as optimal mix percentages in the pulp mix for their minimal weight losses.

Rewinding machines are used in the paper converting industrial sector to unroll paper veils from large source reels and wind them around smaller rolls, for the production of paper logs to be used in household activities. Many different types of rewinding machine exist, and they are mostly based on stapling devices which automatically unroll a large coil of paper, roll it up around a new log, stop the veil allowing it to be torn off, unload the completed paper log, and reload a new paper core to be rolled up. Winding units generally include a primary and a secondary roller, supplying the desired rotational speed for winding, and a pressure unit consisting of a pressure roller in contact with the paper log being rolled up, which assures adequate containment and avoids the paper log to escape. All known systems have some mechanical limitations, mainly due to the contact of the pressure roller with the paper log, causing instabilities and vibrations, particularly when working with soft paper veils. This limits the maximum possible winding speed. The aim of this paper is it to present a detailed kinematic analysis of a novel pressure unit which overcomes the aforementioned limitation.

The traditional method for the identification of paper from different origins relies on microscopy to observe the fiber morphology, which requires professional experience. In this paper, pyrolysis-gas chromatography-mass spectrometry was utilized to analyze five types of traditional Chinese handmade papers, e.g., ramie paper, bamboo paper, bark fiber paper (mulberry paper and kozo paper), and Langdu paper. The results demonstrated that this method can be used to differentiate the four types of handmade papers. A high phenolic compound content was detected in bamboo paper; macromolecular triterpenoids, e.g., β – amyrin, α – amyrin, and stigmastan- 3,5-diene were found in mulberry paper and kozo paper; while those compounds were not found in ramie paper. In particular, a large quantity of phytosterol compounds were found for the first time in Langdu paper. This not only can be used to differentiate Langdu paper from others, but also it helps to explain why Langdu paper can resist insect and mildew activities. Results of the study can provide experimental reference for characterization of traditional handmade Chinese papers via pyrolysis-gas chromatography-mass spectrometry.

To improve the utilization rate of pineapple leaf and crop straw, and provide technical support for making biodegradable fiber mulch paper through organic cultivation, the process and properties of the degradable fiber mulch paper made from pineapple leaf and rice straw were studied. The degradable fiber mulch paper was prepared as a hybrid composite in which pineapple leaf fiber and rice straw fiber were used as raw materials, and environmentally friendly agents were added. A four-factor five-level quadratic orthogonal rotation central composite design of the response surface method was employed. The beating degree of pineapple leaf fiber, basis weight, addition ratio of pineapple leaf fiber, and wet strength agent content were process parameters; dry tension strength, wet tension strength, and bursting strength were objective functions. The optimal technology parameters of pineapple leaf and rice straw fiber mulch paper were 70 to 90 g/m2 basis weight of pineapple leaf fiber, 17% to 25% addition ratio of pineapple leaf fiber, 55 °SR beating degree, and 1.5% wet strength agent content. According to the tensile strength and bursting strength standards, the degradable fiber mulch paper made from pineapple leaf and rice straw was feasible. The results provide theoretical basis and technical support to use pineapple leaves and rice straw to make degradable mulch paper.