Elham Gudarzi; Ajang Tajdini; Shademan Pourmousa; Ahmad Jahan latibari; Mehran Roohnia
Abstract
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 ...
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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. Results: 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.
Physics and Mechanical Wood
shahrzad omrani ghahjaverstani; amir lashgari; mahran roohnia
Abstract
Non-destructive tests today play a vital role in human life. Non-destructive evaluation technology is widely used in industries, especially wood based industries and wood based products and has led to advances in Strength grading lumber, determine the disadvantages of wooden materials, Inspection of ...
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Non-destructive tests today play a vital role in human life. Non-destructive evaluation technology is widely used in industries, especially wood based industries and wood based products and has led to advances in Strength grading lumber, determine the disadvantages of wooden materials, Inspection of timber and wooden structures. The purpose of this research was to estimate the flexural strength of dynamic tests and compare them with the results of static standard tests in two Forest Pine species (Pinus sylvestris) and Rush (Fagus orientalis). The results of the comparison of the estimation of the modulus of elasticity and the estimated modulus of rupture by a non-destructive free vibration method in a free supported beam with similar results from the static test showed a very good correlation So, according to calculations done by applying a safety coefficient of 18% for beech species and 11% for pine species, a non-destructive vibration test can be substituted by a static destructive standard test for estimating the factors mentioned in these two species.
Physics and Mechanical Wood
Mohamad ali Sadatnia; noshin sattari; mehran roohnia; mohsen bahmani
Abstract
The goal of this study was to determine the modulus of elasticity and modulus of rapture of two kinds of date palm (Khasi and Hajmohammadi) using static bending and dynamic (flexural vibration) techniques. To reduce the difference between static and dynamic stiffness values, the static bending modulus ...
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The goal of this study was to determine the modulus of elasticity and modulus of rapture of two kinds of date palm (Khasi and Hajmohammadi) using static bending and dynamic (flexural vibration) techniques. To reduce the difference between static and dynamic stiffness values, the static bending modulus of elasticity was modified by taking into account the value of the shear deflection. In addition to, for better understanding of the mechanical properties of date palm, values were compared with those measured for poplar samples. The results showed that, in Khasi the mean values of the modulus of elasticity obtained by flexural vibration, the static modulus of elasticity, the modified static modulus of elasticity and as well as the modulus of rapture were 47, 67,68 and 38% less than those measured for Hajmohammadi respectively. In comparing with date palm, values measured for poplar samples were more pronounced. The difference between dynamic and static values of modulus recorded for Khasi, Hajmohammadi and poplar samples were 63, 40 and 19% respectively. After modification of the static values, the difference was reduced in to 3% for Khasi, 6% for Hajmohammadi and 7 % for poplar experimental samples. Finally the significant correlation coefficients were found between the static and the dynamic modulus of elasticity for both two kinds of date palm.
Composite wood products
Sina Khodaparast; Ahmad Jahan - Latibari; Mehran Rohnia
Abstract
The effect of compounding process applying two methods of one and two step mixing on the properties of nanocomposite is investigated. Nanocomposites were produced using polypropylene, cellulosic fibers, MAPP and nanolay as reinforcement. 1.5 and 3% MAPP and 0,2, and 4% nanoclay were used as the variable ...
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The effect of compounding process applying two methods of one and two step mixing on the properties of nanocomposite is investigated. Nanocomposites were produced using polypropylene, cellulosic fibers, MAPP and nanolay as reinforcement. 1.5 and 3% MAPP and 0,2, and 4% nanoclay were used as the variable factor and 20% fibers was used. Melt flow index was measured on compounds produced using one or two steps mixing. Either compounds were mixed with fibers and MAPP and then the test specimens were made and tested according to ASTM test procedures. The results revealed that the two steps mixing increased the mechanical properties. The melt flow index of one step mixing was lower and the melt flow index of initial mixing of polypropylene with nanoclay was very high and it was reduced after compounding with fibers and MAPP. The results revealed that at higher dosages of the nanoclay tensile and bending modulus of the composite increased and tensile strength and modulus of rupture decreased.
Composite wood products
Ahmad Jahan- Latibari; Roozbeh Abidnejad; Mehran Roohnia
Abstract
At this research, the influence of Multi Walled Carbon Nano Tubes (Non-functionalized and functionalized) on mechanical properties of polypropylene – old corrugated container (OCC) fibers composites was investigated. OCC fibers polypropylene composites were prepared using 20% OCC fibers, 80% polypropylene ...
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At this research, the influence of Multi Walled Carbon Nano Tubes (Non-functionalized and functionalized) on mechanical properties of polypropylene – old corrugated container (OCC) fibers composites was investigated. OCC fibers polypropylene composites were prepared using 20% OCC fibers, 80% polypropylene and 3% MAPP. Three levels of multi walled carbon nano tubes (0% - 0.5% - 1%) were added. Acidic oxidation method was used to functionalize the MWCNTs. Mechanical properties were measured as defined in ASTM testing methods. The results indicated that at higher dosage of MWCNTs, the tensile strength properties of the composite were improved but the influence of the functionalizing was not statisitaclly significant. The bending strength and elasticity as wellas the izod impact were increased as the higher amount of nanotubes were added to the composite. Scanning Electron Microscopes showed the development of bonding between the composite components. Compostes without coupling agent showed lower bonding strength between polypropylene and fiber as indicated by fiber pull out. However, in the composites containing coupling agent, the fiber fracture was observed.
Management and Economics wood
seyed amirabbas namaki
Abstract
Abstract In this paper, we attempted to investigate the relationship between consumption, demand for imports of fine paper and economic growth using annual time series data in the period of 1984 to 2010. Since the time series are non-stationary (Unit root) and can lead to spurious regression, the stationary ...
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Abstract In this paper, we attempted to investigate the relationship between consumption, demand for imports of fine paper and economic growth using annual time series data in the period of 1984 to 2010. Since the time series are non-stationary (Unit root) and can lead to spurious regression, the stationary of the variables are investigated in its logarithmic form using Augmented Dickey Fuller test (ADF) in two type of intercept without trend and intercept with trend. After applying the unit root test, in order to understand the interaction between economic growth and consumption and imports of fine papers and direction the causal relation, the vector auto regressive (VAR) approach including two models and the causality test of granger are used.The results indicate that GDP growth will increase the consumption of writing and printing papers but this relation is one-sided. On the other hand, there is no causality between changes in GDP and imports of printing and writing paper, and vice versa. Also, there is the one-side causality between GDP and consumption of newsprint. In the case ofThe Granger causality between economic growth and imports of newsprint, due to reject the null hypothesis, there was no relationship found, and vice versa
