The course of consecutive experiments in this report aimed to a research or introductory identification about mechanical and ACOUSTICal PROPERTIES of maple (Acer velutinum) wood. Studied factors were included quality factor (due to internal friction), ACOUSTIC coefficient, ACOUSTICal conversion efficiency as well as the modulus of elasticity (Young’s modulus) which they were all accomplished using contactless magnetic forced vibration of both ends free bar non-destructive method. The research specimens were extracted by solvent washings to reduce their extractive contents. Then their related vibrational PROPERTIES were evaluated consecutively before and after each steps of successive extraction. Comparing to the previous literatures, results here showed that wood from maple is potentially utilizable in backs and ribs of Violin, Tar and wood-wind instruments. Reducing the extractive contents didn't affect the moduli of elasticity but was positive for the quality factor, ACOUSTIC coefficient and ACOUSTICal converting efficiency to improve their future ACOUSTICal performance i.e. musical instrument industry.

The effect of the application of different contents of canola particles in the production of particleboard on its ACOUSTIC PROPERTIES were determined using free vibration on free-free bars procedure.33 samples from each combination of canola and wood particles were prepared and the ACOUSTICal PROPERTIES were determined. Results showed that as the content of canola particles in the mixture of the particles increases, the modulus of elasticity and ACOUSTIC coefficient of boards increases from 1260 MPa and 2.34 m4/s.kg to 1560 MPa and 2.54 m4/s.kg respectively. At the lower content of canola particles in the particles mixture, because of inhomogeneity, damping factor increased but by increasing the content of canola particles more homogeneous boards was obtained and damping factor decreased. Also, results showed that significant increase in ACOUSTIC coefficient efficiency was reached by increasing the content of canola particles. Therefore as the results revealed, incorporating more canola particles in the particleboard mixture, ACOUSTIC PROPERTIES of particleboard improves and the product can be used in ACOUSTIC environments, halls and etc.

Background and objectives: ACOUSTIC property as one of the special characteristics of wood is widely used in making musical instruments. Finding information about the ACOUSTIC PROPERTIES of wood and all factors which improve it is so important. Furthermore, modifying the characteristics of wood with environmentally friendly methods has become increasingly important recently. In the current study, two wood species native to the north of Iran that is Beech (Fagus orientalis L. ) and Maple (Acer velutinum) were examined in terms of their ACOUSTIC PROPERTIES. Samples were also treated under hydrothermal treatment. The effects of hydrothermal treatment on ACOUSTIC PROPERTIES of the samples were measured by free-free flexural vibration method. Materials and methods: In order to examine the ACOUSTIC PROPERTIES of two wood species of Beech and Maple, samples in the dimensions of 360 (longitudinal) × 20 (radial) × 20 (tangential) mm were cut according to ISO 3129 standard. Hydrothermal treatment at 150 ° C for 5 hours was applied on samples. ACOUSTIC PROPERTIES of the treated samples such as modulus of elasticity, damping of vibration, wave velocity, quality of sound, ACOUSTIC coefficient and ACOUSTIC conversion efficiency were evaluated in two directions of Longitudinal-Radial and Longitudinal-Tangential. ACOUSTIC PROPERTIES were compared with control samples. Results: The results of this study showed that hydrothermal treatment of wood has a significant effect on improving the evaluated ACOUSTIC PROPERTIES except for the modulus of elasticity and ACOUSTIC coefficient factor in comparison with control samples. In general, the greatest effect was observed on mortality hydrothermal treatment of wood, the quality of sound, and ACOUSTIC conversion efficiency in species of Maple. The results also indicated that there was no significant difference between the ACOUSTIC PROPERTIES in two directions of Longitudinal-Radial and Longitudinal-Tangential in the treated samples. Conclusion: The effect of hydrothermal treatment on improving ACOUSTIC PROPERTIES of the samples could be due to the withdrawal of water soluble extractives in samples with cleaning material accumulated in vessel ducts, fiber and other structural elements of wood, as well as increased dimensional stability during treatment in treated samples. According to the results of this study, the hydrothermal treatment of wood species, especially Maple species can be used in manufacturing sound-boards as well as resonator boxes of musical instruments such as Xylophones, Violin, and the Iranian Santour.

Background and Objective: Noise pollution is one of the serious environmental issue. Sound control technologies based on sound absorption and sound insulation are considered as the two widely used methods. Therefore, the aim of this study was to modify silica aerogel nanocomposites to improve its ACOUSTIC PROPERTIES. Materials and Methods: This applied experimental research involved in examining eight various types of nanocomposites to evaluate their performance of ACOUSTIC PROPERTIES. In this study, nanocomposites were synthesized by sol-gel method. For this purpose, TEOS and ethanol were added to SiO2 which subsequently stirred and diluted with ethanol as a precursor of silica sol. A solution of 5. 5 M ammonium hydroxide is added drop-wise to the silica sol and then was stirred. The activated silica sol was quickly poured into the mold in which the samples were placed and finally placed in an oven at 150 ° C for 3 hours. The ACOUSTIC PROPERTIES of the samples were measured by the impedance tube and the reduction sound pressure level using a sound level meter. Each sample morphology was characterized by scanning electron microscopy. Results: The sound absorption PROPERTIES of as prepared nanocomposite relatively increased at high frequencies. The results indicated > 0. 6 sound absorption coefficient by the modified nanocopmosites at higher frequencies. The sound absorption coefficient and transmission loss of D1 nanocomposite were higher at medium and low frequencies as compared to other nanocomposites. 4. 6 and 9. 73 dB average reduction of sound pressure level were achieved by either with or without nanocomposite enclosure, respectively, at a distance of 1 meter. Conclusion: The results of the current study showed that the simultaneous addition of organic and mineral materials to silica aerogels (especially with the highest amounts of nanoclay) improves its ACOUSTIC PROPERTIES, especially at medium and low frequencies. Among the samples, D1 nanocomposite shows better ACOUSTIC PROPERTIES at medium and low frequencies. The sound absorption coefficient of D1 nanocomposite at frequencies of 315, 400, 500, 1000, 1250, 2000 Hz were obtained as 0. 27, 0. 38, 0. 51, 0. 78, 0. 83 and 0. 84, respectively. The findings also indicated 9. 37 dB reduction of sound pressure level using D1 nanocomposite.

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Sluggish Cognitive Tempo is used to describe a particular type of attention deficit, concentration, and slowness in information processing. The aim of this study was to investigate the psychometric PROPERTIES of the Sluggish Cognitive Tempo Scale (SCTS) of the parent form among Iranian children. The present study is a descriptive study. A sample of 1700 people was selected from the provinces of Tehran, East Azerbaijan, West Azerbaijan, Kurdistan, Fars and Khorasan using cluster sampling method. 122 subjects were excluded from statistical analysis due to incomplete answers to the questionnaires and thus the final sample was reduced to 1578 parents. The confirmatory factor analysis method and internal consistency were used to compute the Sluggish Cognitive Tempo Scale factorial validity and reliability, respectively. Also, in order to examine the construct validity of the Sluggish Cognitive Tempo Scale, we computed correlations between different dimensions of Sluggish Cognitive Tempo Scale with Attention Deficit Subscale of Mental Health Assessment Questionnaire for Children and Adolescents. The results of statistical results showed that this scale has structural validity, criterion and convergence in Iranian society. The results indicate that the scale is three factors and also the validity of the scale using Cronbach's alpha method and retest test after Approved two weeks. According to the findings of the present study, the parent form of the Sluggish Cognitive Tempo Scale (SCTS) has a good validity and reliability and it can be used in research related to slow cognitive multiplication in Iranian society.

Background and objectives: Wood has been used for making musical instruments for a long time around the world. Manufacturers of these instruments are always trying to improve the quality of wood to make better sound by using special treatments. Santour (Iranian traditional music instrument) is usually made from walnut wood and the quality of its sound is highly dependent on the quality of wood and fabrication methods. Besides choosing the proper wood and manufacturing technics, all performers agree that if an instrument is kept in proper situation, by playing it, the sound quality will become better over the time. As the wood in instruments is under mechanical vibrations during playing, this hypothesis has been investigated that if the wood is imposed to artificial vibrations similar to real music playing, before being used to make the instrument, what changes will occur in its sound characteristics. Materials and methods: To do this, 10 specimens of walnut wood Juglans regia (5 tangential and 5 radial) with dimensions of 200×40×8 mm3 has been prepared. In order to be sure about the similarities of specimens, the ACOUSTIC PROPERTIES of them has been measured. Then all the woods were imposed to light vibrations for 1 month and then heavier vibration for next 2 months. Two vibrating machines were designed and built which produced light vibrations by magnetic force and heavy vibrating by eccentric mass. The ACOUSTIC and mechanical PROPERTIES of wood like Young's modulus (E), sound speed, sound radiation coefficient, Tanδ , were measured before and after vibrating using nondestructive Bing method. Then the woods remained without vibration for another month to find out the durability of changes and the ACOUSTICal PROPERTIES of them were measured again. Results: The results of this research show that these vibrations have improved the ACOUSTIC PROPERTIES of wood. The light vibration had almost no effect on the specimens but the heavier vibration after one month improved the sound quality of wood up to 3% including Young's modulus, sound speed, sound radiation coefficient, and Tanδ . But in the second month of imposing heavy vibrations no significant change was observed. However statistical analysis shows that this changes are not meaningful. One month after finishing the vibrations, Tanδ returned to the previous amount but improvement in E and other ACOUSTIC PROPERTIES looked permanent. Conclusion: The results were not statistically significant and the 3% improvement was very low but meanwhile it can be concluded that if artificial vibrating is imposed for a long time there is a possibility to improve ACOUSTICal propertied of wood.

One of the factors that can be the link between our intentions and actions and their external consequences is human agency, which indicates the conscious design and intentional execution of actions by the individual in order to influence future events.Objective and Method: This research with a developmental approach of psychometric method and method 1, examines the psychometric indices of the Human Factor Characteristics Scale using the classical theory of test score measurement and the graduated question-answer theory. The purpose of this study, which included high school students in Tehran, was selected by cluster sampling of 500 people as a sample size and statistical analysis was performed on 481 data. To collect the data, the ion Human Agent Characteristics Scale (2011) was used and the research questions were evaluated using IRTPRO and SPSS software.Results:The assumption of local independence based on Pearson x2 index was established by applying Simjima's calibrated question-answer theory and the assumption of being one-dimensional based on the analysis of multidimensional question-answer theory. Diagnosis parameters with question-answer approach and classical approach Test score Both item 25 approach had the lowest and item 2 had the highest diagnosis parameter. The answer thresholds for all the questions were so far apart that no option was covered by the other option, and the options were independently selected by individuals at intervals of theta. The total scale was calculated with Cronbach's alpha of 0.945, intentionality of 0.894, foresight of 0.780, self-reactivity of 0.871 and rethinking of 0.762. Also, the role of each item in internal consistency was investigated by the loop method, which all questions had a favorable role in internal consistency of this scale. The value of the validity coefficient obtained from the question-answer theory was obtained by marginal method for intentionality 0.92, forethought 0.85, self-reaction 0.91, rethinking 0.83..

ACOUSTIC neuromas (AN) are schwann cell-derived tumors that commonly arise from the vestibular portion of the eighth cranial nerve also known as vestibular schwannoma (VS) causes unilateral hearing loss, tinnitus, vertigo and unsteadiness. In many cases, the tumor size may remain unchanged for many years following diagnosis, which is typically made by MRI. In the majority of cases the tumor is small, leaving the clinician and patient with the options of either serial scanning or active treatment by gamma knife radiosurgery (GKR) or microneurosurgery. Despite the vast number of published treatment reports, comparative studies are few. The predominant clinical endpoints of AN treatment include tumor control, facial nerve function and hearing preservation. Less focus has been put on symptom relief and health-related quality of life (QOL) . It is uncertain if treating a small tumor leaves the patient with a better chance of obtaining relief from future hearing loss, vertigo or tinnitus than by observing it without treatment. In this paper we review the literature for the natural course, the treatment alternatives and the results of AN. Finally, we present our experience with a management strategy applied for more than 30 years.

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.