Like any other materials the colour of the wood is the result of the reflection of light on the surface of the wood.The explanation is the wood absorbes some of the light visible spectra and as a result of the retlection of other light spectra its colour becomes observable.The colour of the wood has been considered as an important index of its beauty and usage and its determining is not less important than other characteristics.In this study the effects of STEAMING of Fagus Orientals wood discoloration was measured at deterrent time periods and TEMPERATUREs and CIE Lab system was user for colour determination. The findings of this study suggest that STEAMING at 50 and 60°C is better than STEAMING at high TEMPERATUREs like 80 and 90°C considering the lightness of the colour. STEAMING at high TEMPERATUREs causes the sapwood to have a severely two-colored appearance and makes the red heart colour more pronounced.

Ahvaz, Iran Orumiyeh, Iran Date paste as an important date products, has found many applications in food industry in recent years. After production color change and solidifying of the date paste and aggravation during maintenance are considered as the major problems facing the date paste processing factories. This research has carried out in order to overcome the solidification of date paste (Kabkab cultivar) in a full factorial experiment with three factors of: date paste preparation method (two levels of immersion in hot water or STEAMING), added oil (sesame and olive oil as a preservative) and three type of packaging (cellophane, nano silicone and multi-layered) in a split plot design with preparation method as the main plot. Textural properties including hardness, Young' s modulus, shear modulus, and the penetration work done were measured at 0, 1, 2, 3, 4, 5 and 6 months of storage using a texture analyser. The result confirms the positive effect of STEAMING for 10 minutes to maintain the softness paste during the test period. Date paste of firmness made from method of STEAMING and immersion in hot water is 0.02 N and 19 N respectively. The results confirmed positive effect of STEAMING for 10 minutes on date paste softening during storage at.

Iran is not rich in forest land and only 7.5 per cent of country is covered by forest. Therefore Iran has to import wood based panel annually. It is estimated that 100.000.000 Date Palms trees covered an area at about 770.000 hectares around world, and Iran has got 220.000 ha. Because of several reasons Date palm trees should be pruned and each tree produce 10-20 kg residues annually. In this study, for making boards Date Palm pruning residues as raw material and employed UF resin as the binder. STEAMING time (5 and 8 Min.), STEAMING TEMPERATURE (135 and 145oC) and press time (1, 2 and 3 Min.) were used as variable factors and three boards were made in Pilot plant scale for each combination of variables. Samples of all made boards were tested by the methods of EN to obtain mean values of bending strength, and internal bond strength (I.B). In addition samples of each type of board were tested for thickness swelling after soaking in water for 2 hours and 24 hours respectively.The results of this study show clearly that boards have higher mechanical properties than the MDF property requirements which are recommended by EN standard.

In this study Medium Density Fiberboard was produced from 4 year old Poplar clones (P.e. costanzo, P.e. 564.41, P.e. vernirubensis). Fibers length of P.e. costanzo, P.e. 564.41, P.e. vernirubensis were measured 805, 751 and 764 micron respectively. Also fibers diameter of these clones were determined 25.76, 25.44, 25.23 micron respectively. Three STEAMING times (5, 10, 15 minutes) were used for fibers preparation. Also three press times (3, 4, 5 minutes) and two resin contents (9%, 11%) were applied for MDF production. Thus physical and mechanical properties of boards such as MOE, MOR, IB and Thickness Swelling after 2 and 24 hours were investigated. The physical and mechanical properties of boards were tested in based on EN standard. The measurements of bending properties and IB of MDF revealed that increasing STEAMING time caused to decrease MOE, MOR and IB. The highest of MOE, MOR and IB were obtained in 5 minutes STEAMING time. Also the lowest values of Thickness Swelling after 2 and 24 hours were obtained in 15 minutes STEAMING time. The influence of press time on bending properties was not significant. The highest of IB was obtained in 5 minutes press time. As expected, boards demonstrated better properties at higher resin content.

In this study, MDF was produced from Reed (Phragmites australis). Reeds are collected from Hor-Alazym area. The treatments conditions for fiber preparing were as following:- STEAMING TEMPERATURE 170, 180oC(STEAMING pressure 7,9 bar).- STEAMING time 5, 10, 15 minutes.The other production variables were constant.The anatomical properties of Reed such as Fiber length, fiber diameter, lumen cell diameter, and cell wall thickness were measured. LID ratio of Reed fiber was measured 73.69. The physical and mechanical properties of MDF were determined according to DIN standard. The measurements of bending properties and IB of MDF revealed that increasing STEAMING time and STEAMING TEMPERATURE caused to decrease MOR, MOE, and IB.Also the results of MDF dimentional stabilities indicated that Thickness Swelling after 2 and 24 hours decreased upon increasing STEAMING time and STEAMING TEMPERATURE. Degradation of hemicellulose chains may be the reason of decreasing Thickness Swelling.

One of the important issues in the production of concrete is environmental variability that affects the concrete and elements constructed from this material. Due to the importance of different characteristics of concrete in short- and long-term conditions, this article aims to investigate the influence of initial TEMPERATURE conditions of self-compacting concrete on its long-term characteristics and determine the initial optimal TEMPERATURE of concrete. For these purposes, several experiments under three TEMPERATURE conditions of 5, 20, and 40 degree-of-Celsius were conducted to evaluate the rheology and mechanical properties of fresh concrete in the range of 7 and 28 days. In these experiments, alternative mineral admixtures of cement such as micro-silica, fly ash, and zeolite were used to build the concrete specimens. Results demonstrate that the mechanical properties of the specimens increase with increasing initial TEMPERATURE in the short term, while such properties significantly decrease in the long term compared to the specimens constructed under lower initial TEMPERATURE. Moreover, the fluidity of self-compacting concrete increases with increasing initial TEMPERATURE.

In this research, effects of pre-STEAMING of fir wood (Abies alba) on the ACC preservative absorption, retention, and depth of penetration were investigated. Pre-STEAMING was carried out at 120, 140 and 160°C for one hour under 2 to 3 bars pressure. STEAMING was carried out for bastard sawn boards with green dimensions of 250×100×50 millimeter and average initial moisture content of 30%. After moisture conditioning of wood samples, they were impregnated with ACC preservative solution with 5% concentration using low pressure process. Then, the impregnation properties were measured. The image J software was also used to determine the wood cross section impregnation. Results showed that pre-STEAMING at 140 and 160oC significantly increased the absorption, retention, and depth of preservative penetration, however, no significant difference was observed between the control specimens with those pre-steamed at 120oC. Furthermore, the results showed that the wood impregnation properties, including absorption and depth of penetration improved by increasing STEAMING TEMPERATURE from 120 to 160o C.

In this investigation, 36 laboratory Medium Density Fiberboard (MDF) panels were produced using beech wood fibers. Variables were three STEAMING time (5, 10 and 15 minutes), two press time (4 and 6 minutes) and two resin consumption levels (9 and 11%). The physical and mechanical properties of panels were measured and analyzed. The results indicated that the favorite MOR was observed in panels produced through 4 minutes press time, 11% resin consumption and 10 minutes STEAMING time. Also increase in STEAMING time to 15 minutes and press time to 6 minutes, caused the MOR and MOE of boards reduced to minimum level. The internal bonding (IB) of boards decreased with STEAMING and press time increase.  However, the panels produced at 25 minutes of STEAMING time showed minimum of thickness swelling. The results of this investigation indicated that the thickness swelling of boards improved with increase in STEAMING time. However mechanical properties of boards were higher where the shorter STEAMING time applied.