Fabrication methods of microelectromechanical systems have inherent limitations that can lead to micromechanisms with large amount of clearance in revolute joints. Tolerances on link lengths are one of the error sources in MEMS devices, as well. Bistable micromechanisms are the most common actuators used in micro systems. Hence, the analysis of mechanical error of the output variables of these mechanisms is very useful. This paper uses a stochastic method to determine the mechanical error of a special type of compliant bistable micromechanisms called Young micromechanism. Errors of potential energy, required moment and coupler point position of mechanism are evaluated. The range of variations of critical moment of micromechanism and the displacement of second stable point of mechanism are also determined. Specifying this range is useful to determine the energy needed for actuation. The method used in this study is easy and general to use for all planar micromechanisms.

In a walking cycle design, maximizing the upright balance should be considered in addition to the kinematic constraints, energy consumption rate must be considered. The purpose of this study is to find the optimal step length obtained for each person according to the physical features. In this research, in order to minimize energy consumption rate by considering maximum balance two cost function were defined. the fall cost function was designed based on the concept of MOS and balance index. To investigate the upright balance and to reconstruct the movement pattern, Data from normal walking gait of healthy subjects was taken and seven links model was defined. In this study, the optimal step length was obtained for the person with height, weight and gait cycle characteristics. it is shown that for a person of 92kg mass and 1. 87 meters height, the best step length in walking would be 0. 54 meters. In this study, the kinematic and kinetic characteristics of human motion were identified by the analysis of gait patterns on a treadmill. Through the calculation of the balance index, individuals are helped to find the optimal step length for which the maximum balance is achieved. The results of the study can provide the optimal step length to correct the gait pattern.

Background: Palmaris longus (PL) is a muscle with marked variations. It is harvested as a tendon graft in many surgical procedures in which a certain length of tendon is required. The aims of the present study were to determine the variations of this tendon in Iranian population and to find whether the length of PL tendon could be estimated by measuring the forearm length and height.Methods: We examined 128 forearms of 64 cadavers. We dissected out the tendons to measure their lengths and widths. The width of the tendon was measured at its proximal end. The forearm length and height were measured from the styloid process of the ulna to the tip of the olecranon with the forearm in neutral rotation. The height of cadavers were measured from crown to the heel in supine position.Results: The palmaris longus muscles were absent bilaterally in 5 (7.8%) and unilaterally in 14 (21.8%) cadavers. The overall prevalence of the absence of PL (unilateral or bilateral) was 29.6% (24 forearms of 19 cadavers). The mean length and width of the PL were 14.2±6.3 mm and 12.8±7.2 mm in males and 4.00±1.9 mm and 4±2.1 mm in females, respectively. The mean forearms length and cadavers' height were 29±1.6 cm and 172.6±9.1 cm in males and 28±1.2 cm and 166.5±8.9 cm in females, respectively. A significant correlation was found between the length of the tendon and forearm in both males (P<0.001) and females (P<0.001). In contrast, there was not statistically significant correlation between the forearm length and width of the tendon in either males or females (P=0.007 in males and females).Conclusions: The results of this study indicate that the length of palmaris longus tendon can be estimated based on forearm length. This estimation might be useful for surgical intervention.

In this research, it will be paid to evaluate the effects of the link beam length on seismic behavior of eccentric braced frames under near and far-fault earthquakes. For this purpose, four frame structures with different number of stories such as 3, 6, 9 and 12 have been used. For each of these frames, three different lengths of link beam are considered. After designing structures and preparation of non-linear models, these models are analyzed under a suite of 10 and 3 near and far-fault records, respectively. Nonlinear dynamic time history analyses are performed using scaled records for these structures, and the response values of the stories displacement, base shear and the rotation of link beam are evaluated for them. Based on the results of this study, it is specified that increasing the length of link beam and change the mode of the link beam from the shear to bending, the values of stories drift are considerably increased, but the values of base shear are decreased relatively. This result is similar for near and far-fault records. Therefore, it seems that the use of a short link beam would offer a better behavior to the braced frame if the architectural conditions allow. The results showed that in 0. 8 m as an optimal length, the displacement response of frames under near-fault records up to 15 percent larger than the far-fault records. This difference is lower for base shear response.

The seeds of cultivated Trachyspermum copticum L. Link collected in autumn from Research institute of Forests and Rangelands field and extracted by water distillation. The average of humidity was 3.8%. Analyses of essential oil were done by GC/MS which were resulted to identify 9 compounds which contains 100% of oil. Among the identified constituents, p- cymene (32.4%), g- terpinene (27.8%) and b- Pinene (1%) were the major constituents. The contents of phenolic compounds were less than those were reported by other scientists in different countries. It considers the soil ingredients, conditions and the methods of extraction were important on the essential oil contents.

Jojoba is considered as a valuable crop species regarding its tolerance to drought and soil salinity as well as its economical importance as an industrial crop. This species is used on soil conservation activities, against desertification, as an ornamental and landscaping plant and in some extend also can be considered as a nutritional plant. Seeds of Jojoba contain 50-60% liquid wax which is used in electronic, medicine, nutrition and cosmetic industries.The result of this experiment showed that application of 70% ethanol for 5 sec followed by 1% (w/v) benomyl for 30 min and 1% (v/v)sodium hypochlorite containing 1-2 drops of liquid detergent for 15 min caused the highest seed surface sterilizing efficiency.The highest germination rates (90%) were obtained when the seeds were incubated in a 27°C dark germinator for 5-13 days.There was significant differences (P < 1%) among seed germination rates. In this experiment seed germination was examined as most convenience and low cost method of Jojoba propagation.

This study investigates the effect of different link beam lengths in the Reinforced Concrete (RC) frame retrofitted with the Linked Column Frame (LCF) system. It also investigates the ratio of the link beam length (e) to the span length of the RC frame (L) from 0 to 1. 5 for the 9 models of the RC frame retrofitted by the LCF system has been investigated. In addition, it studies the formation of plastic hinges in the RC and Linked Column (LC) frame, distribution of stiffness between the RC and LC frame and the ratio of the structural displacement with the formation of the first plastic hinge in the member of the RC frame at the collapse prevention level (Dp LCF) to the structural displacement with the formation of the first plastic hinge in the link beam (Dy LCF) has been studied. Based on the nonlinear static analysis results, the model with the ratio of e/L= 0. 45 has a better performance than other different lengths of the link beam. In this model, the stiffness of the LC frame has increased about 78% in comparison with the model with the ratio of e/L that is more than 0. 6. Also, the ratio of Dp LCF to Dy LCF for the model of e/L = 0. 45 in comparison with two models of e/L = 0. 3 and 0. 6 is more about 14% and 22%, respectively. It means that, the model of e/L = 0. 45 has more potential to reach the performance level of Rapid Repair (RR) to occupancy.

Jojoba is considered as a valuable crop species regarding its tolerance to draught and soil salinity as well as its economical importance as an industrial crop. This species is used in soil conservation activities, against desertification, as an ornamental and landscaping plant, and in some extend also can be considered as a nutritional plant. Seeds of jojoba contain 50-60% liquid wax which is used in electronic, medicine, nutrition and cosmetic industries. In this experiment, asexual propagation (micro propagation) was investigated. In surface sterilizing experiment, the use of 70% ethanol for 5 sec followed by 1% (w/v) benomyl for 30 min, 1% (v/v) sodium hypochlorite for 20 min containing 1-2 drops of liquid soap, gave the highest sterilizing efficiency. The results of micro propagation experiments showed that the best season for taking explants from the mother plants was late spring. The best hormonal combination for shoot proliferation were 4 ppm BA and 0.01 ppm IBA added to MS medium, while the best hormonal combination for root formation were 0.1 ppm BA and 3 ppm IBA added to MS medium.

Jojoba is a woody evergreen shrub or small multi-stemmed tree native to the semiarid regions of southern Arizona, southern California and northwestern Mexico. The fruit is a green capsule which encloses up to three seeds. Jojoba wax (called oil) makes up 50% of the seed's dry weight. Jojoba is being cultivated to provide a renewable source of unique high-quality oil. Most jojoba oil produced in the U.S. today is sold at a high price for use in cosmetics and hair care products. As many as 300 products containing jojoba have appeared in the U.S. market in recent years. As the supply of oil increases and price decreases, more uses will become economically feasible. For example, the viscosity index of jojoba oil is much higher than that of petroleum oil; therefore, it may be used as a high temperature, high pressure lubricant. The stability of jojoba oil makes it attractive to the electronic and computer industries and since jojoba oil contains no cholesterol or triglycerides and is not broken down by normal metabolic pathways, it may become an important low-calorie oil for human consumption. The oil can be used as an antifoam in antibiotics production and as a treatment for skin disorders. Other proposed uses include candles, plasticizers, detergents, fire retardants, transformer oil, and for the leather industry. The meal contains up to 30% protein, but toxic compounds (simmondsins) make it currently hazardous as an animal feed. Much of the interest in jojoba worldwide is the result of the plant's ability to survive in a harsh desert environment.