Chemical conversion
Zahra Daeepour; amir lashgari; Mehran Roohnia; Ahmad Jahan latibari; Vahid Safdari
Abstract
Background and objectives: Nowadays, the importance of treatments such as water washing and ethanol-acetone washing to improve the acoustic properties of wood has been noticed by the makers of musical instruments. Wood extractives are in the list of those materials that often do not have a construction ...
Read More
Background and objectives: Nowadays, the importance of treatments such as water washing and ethanol-acetone washing to improve the acoustic properties of wood has been noticed by the makers of musical instruments. Wood extractives are in the list of those materials that often do not have a construction role, and their purposeful and correct evacuation can lighten the wood without reducing the stiffness. Carrying out pre-treatments such as fermentation with bread yeast (before water washing and ethanol-acetone washing processes) can lead to the extraction of more extractable substances from wood. In this study, the effect of water washing and ethanol-acetone washing treatments as well as fermentation pre-treatment on the acoustic properties of Ash wood (Fraxinus excelsior) has been investigated.Methodology: Ash wood species (Fraxinus excelsior) was prepared from the wood of a commercial timber and 38 small radial beams with nominal dimensions of 150×12×2 mm (longitudinal×radial×tangential) were extracted from the hardwood. After reaching the equilibrium humidity of 12% in air-conditioned conditions, the selected samples were subjected to the forced vibration test in the free-free beam in order to measure the basic physical and acoustic characteristics. After that, the initial tests were randomly divided into two groups of 19 tests. The first group without pretreatment and the second group with fermentation pretreatment were placed in the process of removing the extractives by water and then by ethanol-acetone mixture. After each step of water washing and removing the extractive substances soluble in ethanol-acetone mixture, the forced vibration test in the free-free beam was performed on the samples and the acoustic properties of the samples were measured.Results: Water washing without pretreatment with bread yeast caused a slight decrease and with pretreatment, it caused a significant decrease in density values (respectively: 1.75 and 7.39%). While the process of removing extractives (with and without pretreatment) by ethanol-acetone mixture caused a significant decrease in density values (Respectively: 2.27 and 8.71%). The modulus of elasticity values showed a significant decrease due to water washing without pretreatment and with pretreatment. (Respectively: 11.37 and 16.47%). The process of removing the extractives by ethanol-acetone mixture also resulted in a significant decrease in the modulus of elasticity values in untreated and pretreated samples (Respectively: 13.87 and 20.93%). Water washing without pre-treatment with bread yeast and with pre-treatment has caused a significant decrease in the values of damping factor, among which the pre-treated samples had a greater percentage of drop in the values of damping factor (Respectively: 13/87 and 20.93%). The process of removing the extractive materials by ethanol-acetone mixture as washing has caused a significant decrease in the damping factor values, which among the pre-treated samples showed a greater percentage drop in the values resulting from this property (Respectively: 3.03 and 18.01%). In this factor, the process of removing the extractive substances soluble in ethanol-acetone mixture (with and without pretreatment) has resulted in a greater drop in damping values (respectively: 6.67% and 20.85%). Acoustic conversion efficiency due to water washing process without pretreatment with baker's yeast caused a slight increase, while pretreatment caused a significant increase in acoustic conversion efficiency values (Respectively: 0.44 and 25.24%). The process of removing extractive materials by ethanol-acetone mixture also caused a significant increase in the acoustic conversion efficiency values, which among the pre-treated samples showed a higher growth percentage in the values of this characteristic (Respectively: 3.41 and 28.90%). Both water washing methods and ethanol-acetone mixture washing were effective in improving the physical (density) and acoustic properties (modulus-elasticity, damping and acoustic conversion efficiency). Meanwhile, the effect of ethanol-acetone mixture washing was more than the effect of water washing. Fermentation pretreatment with bread yeast improved the performance of water washing and ethanol-acetone mixture washing treatments.
Ahmadreza Arabi; Ajang Tajdini; Shademan Pourmousa; Mohammad Naghi Imani; Amir lashgari
Abstract
In order to achieve the higher competitive advantage, identifying and prioritizing the various factors of sustainable supply chain management and its relationship with the performance of the companies producing home and office furniture, have been selected as the main purpose ...
Read More
In order to achieve the higher competitive advantage, identifying and prioritizing the various factors of sustainable supply chain management and its relationship with the performance of the companies producing home and office furniture, have been selected as the main purpose of this study. The statistical population in both the qualitative and quanitative parts consisted of experts, and specialists in the field of sustainable supply chain management and the company performance, including managers and operational engineers of furniture manufacturing companies in Tehran province. In the qualitative part, the interview method and content analysis were used to identify effective factors and in the quantitative part, a reseracher – made questionnaire based on Likert- scale was used to collect data and Pearson correlation and Friedman tests were used to understand the causal relationships between research variables and prioritize them. The validity and reliability of research tools in both parts were tested and confirmed using different methods. The results showed that supply chain management practices have a direct and positive effect on the home and office wooden furniture firms. Also in the sustainable supply chain management, the dimensions of delay time, product cost and design and adaptation to the environment were given first to third priority. Also in terms of performance, the dimensions of rapid response and the proposed changes of customers in the responsible volume, investment returns and customers' preference to buy from top names were given first to third priority.
Management and Economics wood
Sina Mohamadi Nematabad; Shademan Pourmousa; Ajang Tajdini; Ahmad Jahan latibari; Amir Lashgari
Abstract
The applied purpose of this study is to determine and prioritize the components of production sustainability in the courrugated box making industry by using qualitative analysis.Through library studies and review of available resources, seven main components affecting the sustainability of production ...
Read More
The applied purpose of this study is to determine and prioritize the components of production sustainability in the courrugated box making industry by using qualitative analysis.Through library studies and review of available resources, seven main components affecting the sustainability of production in the courrugated box making industry were named: rules and regulations, economic, environmental, technological, social, human resourcess, materials and products and 43 sub-components were identified.By preparing researcher-made questionnaires and distributing it among managers and experts in the courrugated box making industry with the aim of influencing each component and sub-component on production sustainability and their current status, the results were analyzed by relevant tests. All components affecting production stability based on standard coefficients and significance of structural equations as well as predictive criteria for confirmation and quality of data presented with redundancy index with cross-validity showed that the data have the necessary validity to predict. The components were prioritized based on average rank and distance to stability. Based on the results, economic, material, product and technological components showed the shortest distance and bio-environmental components, rules and regulations showed the longest distance to achieve stability in the carton industry. Therefore, in order to achieve sustainable production in the carton industry, environmental components, laws and regulations must be given more attention. Research components were prioritized based on average rank and distance to stability. Based on the results, economic, material and product and technological components showed the shortest distance but environmental, rules and regulations components, showed the longest distance to achieve stability in the industry. Therefore, in order to achieve sustainable production in the industry, environmental, laws and regulations components must be given more attention.
Shahram Badamchizadeh; Ahmad Jahan Latibari; Ajang Tajdini; Shadman Pourmousa; Amir Lashgari
Abstract
The first step in feasibility study of any national mega projects in energy sector is the investigation on the production potential and evaluate the market demand for the product. The success rate of a biofuel project after forecasting supply and demand depends on choosing the appropriate place to produce. ...
Read More
The first step in feasibility study of any national mega projects in energy sector is the investigation on the production potential and evaluate the market demand for the product. The success rate of a biofuel project after forecasting supply and demand depends on choosing the appropriate place to produce. In this respect, factors such as the selection of appropriate production site, environmental, technical, economic and social are among major issues. In this study, autoregressive integrated moving average (ARIMA) model was used for the prediction of bioethanol demand in five sceneries; E5, E10, E15, E20 and E30. The time period up to 1412 is foreseen. The data on agricultural wastes and the present and future potentials for the bioethanol production in different provinces is analyzed. The results indicate that, the average daily consumption of gasoline will increase to 136,922 million liters per day as we reach 1412.The study also shows that there exists the potential for the production of 18.16 million liters of bioethanol which can fulfill the requirement of E5 and E10 by 1412. If we want to implement the E20 and E30 scenario in the country, it is necessary to increase the production of 7 selected products in this research, in the provinces of Khuzestan, Fars, Khorasan Razavi, Golestan, Isfahan, Mazandaran, Tehran, Qazvin and Alborz and Gilan by 62.2 million tons per year by 1412, And consider the effective factor in the success of the project, namely the support of the government and legislators for national mega projects.
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 ...
Read More
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
Parastoo Majdabadifarahani; Mehran Roohnia; amir lashgari
Abstract
DOR:98.1000/1735-0913.1398.34.87.66.1.1585.1588 This study deals with the possibility of evaluation and estimating the wood density in Quercus castaneifolia and Fagus orientalis. Wood samples were prepared and cut firstly in 4×20×30 cm (thickness×width×length). Then their density ...
Read More
DOR:98.1000/1735-0913.1398.34.87.66.1.1585.1588 This study deals with the possibility of evaluation and estimating the wood density in Quercus castaneifolia and Fagus orientalis. Wood samples were prepared and cut firstly in 4×20×30 cm (thickness×width×length). Then their density was calculated after 72 hours of conditioning in an oven at 60°C temperature. In thermography process, the temporal temperature was monitored in 1st, 5th, 10, 20, 30, 45 and 60th minutes of cooling (monitoring steps). Investigating the effects of shape factor and dimension on thermographic density evaluation errors, the specimens were cut down in two more steps to 3×20×30 cm and 2×15×20 cm and the course of thermography experiments was repeated. The relationships of shape factor, density and the ratio of density to the shape factor with the logarithmic cooling rate were evaluated separately. Results showed that density without considering the shape factor variations was not sufficiently correlated to the cooling rate. But the ratios of the density to their proper shape factors were promising for the density evaluations from the cooling rates. However, it is suggested to revise this non-destructive method using a larger variety of the wood specimens and species.
amir lashgari; seyyedeh zahra hashemi; BABAK RANJBAR
Abstract
DOR:98.1000/1735-0913.1398.34.134.66.1.1576.1585 Wood is a natural material, human beings have long been in close contact with wood, and psychologically, wooden structures, and any kind of wood-craftsmanship, give people a sense of relaxation. This research was conducted to investigate the relationship ...
Read More
DOR:98.1000/1735-0913.1398.34.134.66.1.1576.1585 Wood is a natural material, human beings have long been in close contact with wood, and psychologically, wooden structures, and any kind of wood-craftsmanship, give people a sense of relaxation. This research was conducted to investigate the relationship between wood color and wood decor at work and living on emotional and psychological reactions of individuals. To this end, 384 people from Karaj city were selected as random sampling method. In this research, a researcher-made questionnaire was used. In inferential statistics, SPSS tests including Kolmogorov-Smirnov test (for data normalization) and correlation test were used. Results of research analyzes, research hypotheses based on the effect of the color of the decor of the place of residence and work on the reactions Psychological and emotional affirmation. Considering the importance of the subject in psychology, in this research, the most recent methods and methods have been used. Keywords: color decoration, psychological responses, emotional reactions, research, SPSS, wood.
Mechanical conversion of wood and wooden fittings
Ehsan Ketabi; Amir Lashgari
Abstract
In this study was to evaluate the impact of the truss structure on stiffness and stress distribution in the truss structural members. Made and synchronizes this structures with any Populus_ Nigra lumbers, in finally made 44 truss structure with 11 varying samples and 4 replicates. were used by two joint ...
Read More
In this study was to evaluate the impact of the truss structure on stiffness and stress distribution in the truss structural members. Made and synchronizes this structures with any Populus_ Nigra lumbers, in finally made 44 truss structure with 11 varying samples and 4 replicates. were used by two joint like friction joints was created with Glue stick and dual joint was created with nails to the 4.5 cm and calculate the resistance trusses structures by mechanical testing machine with 12.5 mm/min loading speed and 3.5 KN than mechanical test results showed, Hip Girder truss most resistance stress distribution and were the least impact on the strength and distribution of tension truss structure is significant in 95%. To show the stress distribution on the members, modeling software was AutoCAD, Catia and finite element analysis software was ANSYS. In finally the results show that maximum stress concentration, failure to engage in experimental mode.
Mechanical conversion of wood and wooden fittings
Soheila Zamaninasab; amir lashgari; azhang tajdini
Abstract
In this research, resistance and stress concentration on the seat structure were examined by changing the type of connection (tongue and groove connection , and double connection). platanus orientalis used to make wooden chairs. Moreover, we applied Ansys to calculate resistance and mechanical testing ...
Read More
In this research, resistance and stress concentration on the seat structure were examined by changing the type of connection (tongue and groove connection , and double connection). platanus orientalis used to make wooden chairs. Moreover, we applied Ansys to calculate resistance and mechanical testing machine with a load of chairs 7/12 mm per minute to show the stress distribution on the chairs members . The results show that chairs by tongue and groove connection and having a simple structure and with bail , have more resistance and less stress distribution than a double chair with a simple structure and with indicating connection and the impact of the type of connection were significant on the chair resistance . The stress distribution shows that the maximum stress concentrations on the horizontal joints are visible . Finite element models show that the stress distribution is more uniform in chairs with tongue and groove connections.
Amir Lashgari; Ayob Eshghi; Abolfazl Karegarfard; Ajang Tajedini
Abstract
In this research, the effect of nanoclay-particles on physical and mechanical properties of composites made using almond shell powder-polypropylene was studied. For this purpose, almond shell powder and nanoclay were used in three levels of 30%, 35% and 40% for almond and 0%, 2.5% and 5% for ...
Read More
In this research, the effect of nanoclay-particles on physical and mechanical properties of composites made using almond shell powder-polypropylene was studied. For this purpose, almond shell powder and nanoclay were used in three levels of 30%, 35% and 40% for almond and 0%, 2.5% and 5% for nanoclay. In addition, 2% of Maleic Anhydride Polypropylene was added to all compositions. Then, wood-plastic nano-composite was formed using counter-rotating twin screw extruder and injection molding machine. Mechanical test including tensile, flexural, impact resistance, hardness and physical properties including water Absorption and Thickness Swelling after 2h and 24h immersion in water were measured. In addition X-Ray Diffraction (XRD) experiment was carried out to reveal how clay nano-particles are distributed across the manufactured composites and Scanning Electron Microscope (SEM) was also performed to investigate fracture surfaces. The results indicated that the presence of nano-clay did not influence the flexural and tensile elasticity modulus, and the presence of nano-clay reduced tensile and flexural resistance. The hardness and density of composites were higher than pure plastic and the impact resistance of all composites was lower than pure plastic. The presence of nano-clay did not significantly effect the physical properties of the composites (p< 0.05).The diffraction model of X-ray showed that nano-composite forms intercalation interlayer structure and the results of morphological investigation revealed that the samples containing 2.5 percent nano-clay and 35 percent of almond shell have the highest array of intercalation and the best transmittance.
Hanieh Ghasemi; Ahmad Jahan Latibari; Abolfazl Karegarfard; Amir Lashgari
Abstract
The impact of the addition of different amounts of canola straw to the composition of the hardwood particles for the production of particleboard was investigated. Four levels (0, 15, 30 and 45%) of Canola particles were added to hardwood particles and then particles were blended with 12% urea resin (based ...
Read More
The impact of the addition of different amounts of canola straw to the composition of the hardwood particles for the production of particleboard was investigated. Four levels (0, 15, 30 and 45%) of Canola particles were added to hardwood particles and then particles were blended with 12% urea resin (based on the oven dry weight of the particles). Boards at three densities of 550, 600 and 650 kg/m3 were produced. The flexural and internal bonding strength and water absorption and thickness swelling after 2 and 24 hours immersion in water of the boards were determined using appropriate EN standard test methods. Addition of different amounts of canola particle to the hardwood particles did not change either modulus of rupture or modulus of elasticity of the boards, but the internal bonding of the boards was reduced. As the dosage of the canola particles increased, both water absorption and thickness swelling were reduced. Increasing the density of the boards increased both strength and dimensional stability.
amir lashgari; Payam Khodayari; Seid Ali Mohammadi
Abstract
In this research the effect of nail′s length on three different values (32,42,48 mm)the nail number (2 and 3)and the kind of of particleboard and MDF on tensile strength and bending moment has been analyzed ,The member dimension of of 10*15*1.6 cm.have been elected for making of L –type ...
Read More
In this research the effect of nail′s length on three different values (32,42,48 mm)the nail number (2 and 3)and the kind of of particleboard and MDF on tensile strength and bending moment has been analyzed ,The member dimension of of 10*15*1.6 cm.have been elected for making of L –type joint. The junction have not used out of any adhesive as an adjuvant. From combination of this variable factors and examination of any strength some 24 samples have created,that due to the 4 iterations,96 specimens of L shaped joints have been coustructed totally.the bending and tensile strength of produced junction has been measured by mechanical test machine.based on captured results the interaction of constituents of,nail penetration length,nails number and members nature on joint strenght weren′t significant in front of tensile and bending.this research indicated that the junctions with the penetration length of 48 mm,the most amount of nail(three nails)on MDF member elements,have the greatest strength against bending strength,and the link with penetration length of 42mm alone with the most amount of nail(3 nails)on MDF have the greatest strength against tensile,as copared with each other.
amir lashgari; Mohssen Ahmadi
Abstract
Aim of this study were to examine the effects of pin diameter (6, 8 and 10 millimeter), the pins interval ( 30,50 and 70 millimeter), wooden pin penetration depth (2d,3d and 4d D=Diameter of pin) and the shape of H joint on bending strength of the joint. In order to make the H joints, the dimension of ...
Read More
Aim of this study were to examine the effects of pin diameter (6, 8 and 10 millimeter), the pins interval ( 30,50 and 70 millimeter), wooden pin penetration depth (2d,3d and 4d D=Diameter of pin) and the shape of H joint on bending strength of the joint. In order to make the H joints, the dimension of the middle member was selected as 200x125x16 millimeter and the dimension of the side members were selected as 250x125x16 millimeter. MDF was used to make the joints. The wooden pin used in the present research was made from hornbeam (Carpinus betulus) which is common pin in the market. PVA glue was used to make pin joints. Twenty seven treatments were obtained out of various combinations of the variables and considering four replication for each treatment, 108 H-shaped samples were prepared. The bending strength of the joints was measured. The results from mechanical test indicated that for each pin penetration depths in H joint, increasing the distance between pins, the bending strength decreased. Maximum bending strength was related to the pins having diameter of 10 millimeter. In 4d penetration depth, for each three diameters of 6, 8 and 10 millimeter, the maximum bending strength was reached on 30 millimeter intervals. The minimum bending strength for the pin having 6 millimeter diameter was obtained in the interval of 10 millimeter. The same results were obtained for the 2d and 3d penetration depths.
amir lashgari; Peyman Sinambari
Abstract
Effects of screw length (2, 2.5,3 inch), wood species (beech, alder, white spruce), and two screw interval (2, 2/5 cm) on bending strength of the T-type joints were investigated. In order to fabricate the T –shaped joints, dimensions of the parts were determined as 15*5/5*2/5 cm. From the ...
Read More
Effects of screw length (2, 2.5,3 inch), wood species (beech, alder, white spruce), and two screw interval (2, 2/5 cm) on bending strength of the T-type joints were investigated. In order to fabricate the T –shaped joints, dimensions of the parts were determined as 15*5/5*2/5 cm. From the above variables, 18 combinations were reached. Four replications, and a total of 72 specimens were made and the mechanical strength of the specimens were measured by mechanical testing machine. Results indicated that the beech joints with 3-inch length screws had the highest bending strength, while the lowest bending strength was observed in spruce wood with 2-inch length screws. The study revealed statistically significant differences between the wood species, while there were not any difference between screw interval and bending resistance.
Mechanical conversion of wood and wooden fittings
amir lashgari
Abstract
In this study, distribution pattern and tension concentration as well as failure prediction in dowel joint were analyzed. The effect of dowel diameter (6, 8, 10 mm) and wood type (Beech, Alder and white spruce) on tension resistance and bending moment were examined. The dimensions for making T-form joints ...
Read More
In this study, distribution pattern and tension concentration as well as failure prediction in dowel joint were analyzed. The effect of dowel diameter (6, 8, 10 mm) and wood type (Beech, Alder and white spruce) on tension resistance and bending moment were examined. The dimensions for making T-form joints were 5×5×2/5 cm. Wooden dowel used in this research was carpinus betulus which accounts as the common dowel in market. Also, PVA was used in Joints. A total of 36Tshape samples comprising 9 combinations of the above factors in 4 replications were made. Tension resistance and bending moment were measured by mechanical test machine. For exertion strength due to analyzing the resistance loading speed equal to 1.25 mm/min were applied. Also, to analyze distribution pattern and tension concentration in affected joints, finite element method and ANSYS Software were used. According to the results of the simulation modeling, joint which endured the maximum tension complied with the real joints. Distribution of tension in the middle of the bending moment depth was greatest and tension in dowel joints was concentrated in impaired points.
Mechanical conversion of wood and wooden fittings
amir lashgari; Ahmad Jahan latibari
Abstract
The influence withdrawal strength and bending moment of mortise and tenon joint is investigated. Based on vast application of this type of different length of joint, the effect of tenon lengths (20 , 30, 40, mm) and wood type (beech, alder,spruce) These strength properties is investigated. 9 combination ...
Read More
The influence withdrawal strength and bending moment of mortise and tenon joint is investigated. Based on vast application of this type of different length of joint, the effect of tenon lengths (20 , 30, 40, mm) and wood type (beech, alder,spruce) These strength properties is investigated. 9 combination of variables and total of 72 T-shape samples were tested at loading rate of 1.25 mm/min. The combination of variables significantly in fluences the load bearing capacity of joint. Joint produced with tenon lenghts of 30 mm and alder wood showed highest withdrawal strength and the joint produced at the tenon length and beech wood showed highest bending moment so this combination of variables is recommended.
