مجله تحقیقات علوم چوب و کاغذ ایران
سال سی و هفتم شماره 1 (پیاپی 78، بهار 1401)

This study aims to identify the expectations and preferences of consumers of home and office furniture using nonparametric tests. The statistical population consists of customers of the home and office wood furniture industry in Tehran and a stratified sampling method was used in this study. Cochran formula was used to determine the sample size. To determine the effective indicators, the researcher studied the available resources and the Van et al.’s model as the basic model and conducted a factor analysis to design the conceptual model of the research. Using a field research, the student t-test and Friedman test, she examined the relationship between consumer preferences and 5 factors and 17 subindices.

The reliability of the questionnaire was confirmed by the data obtained from 100 questionnaires using Cronbach's alpha. The results of descriptive statistics indicated that the mean of all the indices was at an average level. The minimum and maximum values and the standard deviation showed that there were no outliers. The results of inferential statistics in SPSS software indicated that as the significance level for Kolmogorov-Smirnov test was greater than 5%, all variables are assumed to be normally distributed. The results indicated a significant relationship between all indicators and consumer preferences regarding home and office furniture. The results of the one-sample t-test indicated that consumers consider corporate responsibility factors, product and vendor’s characteristics and internal factors above average while they consider environmental and safety factors at the average level in the purchase of home and office furniture. The results of the Friedman test indicated the priorities as follows: vendor’s characteristics, internal factors, corporate responsibility factors, product characteristics and safety and environmental characteristics.

In this research, the effect of  using nano-zinc oxide (nano-ZnO) as a UV absorbent on the weathering resistance of wood- polypropylene composite was investigated. For this purpose, composite samples containing 0, 1, 2 and 3% nano-ZnO were manufactured using an internal mixer and a laboratory press. The prepared specimens were exposed to artificial weathering for 1480 hrs (in the periods of  0 ,480, 960 and 1480 hrs). The weathering degradation of specimens was monitored by tensile strength, hardness, colorimetry, Fourier transform infrared spectroscopy (FTIR), and, stereomicroscope tests. Results showed that weathering  caused color changes, tensile strength and hardness loss, physical and chemical degradation on the surface of the samples. The use of nano-ZnO partially prevented tensile strength and hardness loss of samples as well as their surface degradation.  In general, the use of 2% nano ZnO has been a better performance against weathering than other values.

One of the common applications of cellulose is dissolving pulp producing that requires high purity. Different cellulose sources are used to produce dissolving pulp. Due to Deforestation and lack of agricultural land and problems with cultivation, the use of wood and non-wood sources of cellulose is declining. Another source of cellulose is recycled pulp. Chlorine dioxide acts as a completely selective bleaching. Increasing kappa factors is very effective in removing lignin levels. In this research, dissolving pulp from recycled fibers is obtained during soda cooking and bleaching with chlorine dioxide. Then, the effect of changes in kappa factor of the second stage of chlorination on chemical composition (holocellulose and lignin), structural properties (degree of polymerization, alpha-cellulose and degree of brightness) and accessibility (water retention value) are investigated. The results showed that the degradation of holocellulose levels was not severe and did not cause cellulose damage and decreased alpha-cellulose levels as well as the degree of polymerization. The removal of lignin as a hydrophobic component and the presence of hemicellulose as a hydrophilic component increase accessibility (water retention) and decrease brightness degree.

One of the most important economic goals of any state or economic system is to maintain a competitive position in every market. Competition in the market is ultimately improving the well - being of consumers and economic performance. Market analysis in order to resolve appropriate decisions by relevant agencies requires recognition of its structure. In order to judge the extent of competition and monopoly on each market, the concept of Concentration is primarily used. Different indicators are used to measure the market concentration. This study was conducted with the aim of assessing the market concentration of Iran bedroom furniture and showing changes for the period from 1388 to 1397. In this regard, indicators of market concentration such as Concentration ratio, Herfindahl-Hirschman, Hall-Tiedman, Comprehensive concentration index and Hana-Kay were calculated. According to the results of the Herfindahl-Hirschman index, the furniture import market in this period is uncompetitive and the kind of monopoly of the firm and in 1396 year the market structure of a multi - lateral monopoly. According to the Hall-Tiedman Index, the market structure was a multi - faceted monopoly. Comprehensive index values of industrial concentration show a multi - sided monopoly market. The increase in the values of the Hana-Kay index has reached from 1388 to 1397, indicating a decline in the monopoly of the market. In general, in this regard, indicators of market concentration such as, Concentration ratio, Herfindahl-Hirschman, Hall-Tiedman, Comprehensive concentration index and Hana-Kay were calculated. The results show the existence of an oligopoly on the market. Monopoly has fluctuated with regards to the countries political-economic conditions in the mentioned period.

In this study, the effect of silica nanoparticles and heat treatment of beech (Fagus orientalis),walnut (Juglans regia) and spruce (Picea abies) wood species on adhesion strength, drop contact angle and water absorption of clear coating lacquer were studied. For this purpose, samples with 8% moisture and 200 × 100 × 20 mm were prepared. The wood samples were heat treated in oven at different temperatures of 160 and 180 °C for 3 hours. After finishing the treatment, the surface finish of the specimens was 120 and 180, respectively. Transparent lacquer folders containing 0, 0.5, 1 and 1.5% silica nanoparticles were used to cover the samples. The results showed that heat treatment increased the drop contact angle and the adhesion strength of the coating and increased the temperature of the drop contact angle treatment and the adhesion strength as well. Thermal treatment at 180 °C with coating containing 1% nano and lowest drop contact angle was observed in control samples. Wood samples treated with walnut at 160 ° C and containing 1% nano coating had the highest adhesion resistance. The water uptake of treated wood samples decreased compared to the untreated samples in all three species and this trend continued with the increase of nanoparticles in the coating so that the walnut control samples had the highest water uptake at 180 °C. and 1% nano coatings were the lowest water absorption in spruce.

The aim of this study was to evaluate the effect of cellulose nanofiber treatment on discoloration of historical papers. In this study, two types of cellulose nanofiber suspensions with a concentration of 1% by weight with water and ethanol were prepared. After treatment, the prepared samples were subjected to moist-heat aging according to TAPPI T 544 sp-03 standard and colorimetric, pH, ATR-FTIR spectroscopy and SEM microscopy were performed before and after aging. Examination of ATR-FTIR spectra obtained from the samples showed that the application of cellulose nanofiber treatment does not cause damage to the paper structure. After application of two treatments with cellulose nanofibers, the color of the samples became brighter, but after accelerated aging, the brightness of the samples decreased.The darkening of the color of the samples was caused by their exposure to accelerated aging conditions and the treatment of cellulose nanofibers did not cause discoloration. The pH of the samples increased after application of both types of cellulose nanofiber treatments, but after accelerated aging, the pH decreased slightly.

Utilization of ionizing rays like gamma-ray in polymers to correct their properties has attracted so much attention from researchers. Therefore, in this study, polypropylene as the composite matrix, maleic anhydride (MAPP) as the compatibilizer material, and poplar wood as the filler were placed under the radiation of gamma-ray with different doses from 0 to 75 kGy. The white rot fungi (Trametes versicolor) and, brown rot fungi (Gloeophyllum Trabeum) were used in fungal decay test. The main purpose of this study is to investigate the probable benefits of gamma-ray radiation for improvement of some of the composites physical and mechanical properties, and also, to investigate the biodegradation in fungal decay and thermal properties. The results indicates that radiation of gamma-ray improves the physical and mechanical properties of some structures, and the decay resistance of the WPCs against brown and white rot fungus according to their weight losses. The uniformity of the micrographs obtained from the scanning electron microscope (SEM) indicated that the interaction between the polymer and wood fibers.