For investigation of withdrawal strength in dowel joint, the effect of dowel diameter (6, 8 and 10 mm), distance between dowels (20, 25 and 30 mm) and wood type (Beech, Alder and Spruce) were studied. The dimensions of malcing T-form joint in dowel joint were 5*5*2.5cm.Type of wooden dowel using in this research was carpinus betulus which is the common dowel in malced. Also, PVA was used in dowel joint a glusive. According to, 27 treatment and 4 replicate, totaly 108 T-shape samples were tested. The results indicated that the highest and lowest withdrawal strength has been shown in beech and spruse, respectively. By increasing the dowel diameter from 6-8mm, the withdrawal strength increased, and with increase of dowel diameter to 10mm, this property decreased. The highest withdrawal strength was related to 25mm distance.

Glue joints are more useful agents in Aerospace industry. So in this article we presented a new method for used of glue joint. In this method the maximum stresses that occurs at the edges of the bottom of glue joint and cause ultimate failure in this type of connection is decreased and therefore increases the glue joint strength. In this method the glue in the overlapping area is considered discrete and separate columns. Also, the connection is assumed to be uniform for the proposed method. As a result of this case is used of less glue in the connection. First the proposed method is studied and distribution of tension in the glue is analyzed. Then glue joints for common conditions are modeled with finite element softwares.

The present study describes the effect of friction welding process on mechanical and metallurgical properties of AISI 304 steel. The joints were made by direct drive friction welding (DDFW) machine, while the characteristics of friction welded joints were evaluated by macro-microstructure, microhardness, tensile test with 4 mm and 6 mm effective diameter, and scanning electron microscope (SEM). The results showed severe flash formation at stationary side related to rotating side, highly plastically deformed zone (HPDZ) was revealed at the interface with large dimension of 110 µm. Maximum microhardness values were recorded at welded center and increased from peripheral to central zones. Reducing ratio of ultimate tensile strength (UTS) and ductility for welded joint related to AISI 304 were 86 and 67%, respectively. Tensile fractures occurred adjacent to the interface at thermo-mechanically affected zone (TMAZ). Fracture morphologies by SEM were discovered cleavage features and mostly ductile mode with micro-porosities of different forms and dimensions

The influence of dowel joint parameters in particleboard fastening on shear load of joint is investigated. Based on wide application of this type of joint in panel products, in this study the effect of dowel diameter (6,8,10 mm), dowel depth of penetration (2d, 3d, 4 diameter), dowel freedom in the hole (less than 0.25, 0.25, 0/5 mm) and dowel type (rough or smooth surface) shear load of dowel joint is investigated 54 combination of variables and total of 216T -shape samples were tested at loading rate of 1.25 mm/min. The results indicate that each independent variable as well as the combination of four variables significantly affect the capacity of joint. joint produced with rough dowel of 10mm diameter, depth of penetration of 4d and freedom of either 0.25 or 0.5mm showed the highest capacity and this combination of variables is recommended.  

The objective of this study was to investigate the effect variables on tensile load of dowel joints in particleboard fastening. T-shape samples were made. Variable factors included dowel type: smooth and rough, dowel diameter: 6,8 and 10 mm, degree of freedom of less than 0.25, 0.25, 0.5 and depth of penetration 2D, 3D and 4D. Combination of above variable factors revealed 54 treatments Considering four replication for each combination, a total of 216 samples were made and tensile load of joints were measured. Tensile load of rough dowel joints with 10mm dowel diameter, 4D depth of penetration and 0.5mm degree of freedom was superior. The measured load at this combination of variable was 1.76 KN.

Background and Objective: Recent conservative management of sub-acromial shoulder impingement (SSI) includes general strengthening exercises, especially for internal (IR) and external (ER) shoulder rotators. Despite various studies, so far, there is no directly investigated for indicating the difference in muscle strength between patients with SSI and normal subjects. This study was done to compare the shoulder joint muscles’ strength in male students with and without SSI. Methods: This case-control study was conducted on Twenty-four students with SSI as case group and 24 normal students as controls. The subjects in both groups matched for hand dominance and physical activity level, completed isokinetic shoulder IR and ER testing. In the case group, 18 patients had the symptoms in their dominant and 6 patients in their non-dominant side. Both sides IR and ER of shoulder were measured separately using continuous reciprocal concentric and eccentric contraction cycles at speed of 60 and 120 degrees per second, respectively. Values of peak torque were compared between the case and control groups. Results: There was a significant difference between the two groups only when the symptomatic SSI shoulder was the dominant shoulder. Eccentric and concentric ER peak torque at 120 degree per second (22. 20± 7. 01, 11. 36± 3. 36), eccentric ER peak torque at 60 degree per second (20. 53± 6. 15) and eccentric IR peak torque at 60 degree per second and 120 degree per second were significantly lower in the symptomatic dominant shoulder case group in compared to the dominant shoulder control group (P<0. 05). Conclusion: Changes in eccentric and concentric peak torque in SSI group may be related to limb dominance, which may have implications for strengthening regimes. Therefore, clinicians and therapeutic exercise expertise may benefit from eccentric isokinetic exercises for shoulder IR and ER rotators in order to design a treatment plan for patients with SSI.

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 combinations 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.

Several full porcelain systems are available in the market, among which In - Ceram (Vita Zahnfabrik, Bad Sackingen, Germany), has been introduced to show unique properties including: fine esthetic and high quality strength. In this investigation Flexural strength of In - Ceram core material has been evaluated by four - point bending test with Instron (Model 1195) machine. Samples were provided in form of ten bars of core material with the dimension of 30 × 6 × 2.5 mm.Results obtained show that the mean value of 538 ± 42 (MPa), of force is required to hit its resistance limit which is higher than similar values in other dental ceramics, within acceptable clinical range.

Background and Aim: ZOE has been used in different fields of dentistry for many years. A locally produced component (Zoliran) has been recently introduced to the marketwith similar characteristic to the original Zonalin. Because of a lower cost involved to use Zoliran cement and its availability, confirm reliability of its physical properties. This investigation was designed to assess the Compressive strength of Zoliran cement in comparison to Zonalin cement as the standard material. Materials and Methods: Five samples with dimension of 4mmx6mm of each cement were provided and stored in distilled water in 370C±10C for a period of 24 hours. The lowest load of force was registered as the reference to which the sample could be broken by(according to the criteria No: 30 of ANSIIADA). The value of compressive strength was then calculated using the following formula (K =4F/πD2 ). Results: The mean compressive strength of five samples was measuredas: 14.33 Mpa for Zoliran cement and 31.83 Mpa for Zonalin cement. The mean compressive strength of Zonalincement was significantly higher than the mean suggested in ANSl/ADA Specification No.30. The mean compressivestrength of Zoliran cement was also lower than the mean value registered in ANSI/ADA SpecificationNo.30. Conclusion: Compressive strength of Zoliran cement was significantlylower than that of Zonalin cement. Further tests are required to compare the other physical properties of this material before it can be clinically recommended.