The increase of shear strength in soil, reinforced with the geogrid (alternate reinforcer), is resulted from an increase of modulus of soil hardness, and also from the tensile strength of reinnforcer. The shear strength of contact surface in soil appears due to both the friction strength against the contact surface, and the passive strength formed in front of the elements of the geogri...

Deformation modulus of rock mass has a significant role in the support design of an underground excavation. It is determined by expensive in-situ tests or by empirical models. Existing models for estimation of deformation modulus do not consider its stress dependence. Herein, data from several sources is used to develop a stress- (depth-) dependent relation for estimation of deformation modulus...

the purpose of this study was to evaluate the shear bond strength (sbs) of orthodontic brackets bonded with two types of nano-composites in comparison to a conventional orthodontic composite.sixty extracted human first premolars were randomly divided into 3 groups each containing 20 teeth. in group i, a conventional orthodontic composite (transbond xt) was used to bond the brackets, while two n...

in this paper a new method based on strut-and-tie model (stm) is proposed to determine the shear capacity of simply supported rc deep beams and an efficiency factor for concrete with considering the effect of web reinforcements. it is assumed that, the total carried shear force by rc deep beam provided by two independent resistance, namely diagonal concrete strut due to strut-and-tie mechanism ...

objectives: micromechanical retention of resin cements to alloys is an important factor affecting the longevity of metal base restorations. this study aimed to compare the bond strength and etching pattern of a newly introduced experimental etchant gel namely nano met etch with those of conventional surface treatment techniques for nickel-chrome (ni-cr) and high noble alloys.  materials and met...

o bjectives: the purpose of this study was to evaluate the effect of salivary ph on the shear bond strength (sbs) of orthodontic brackets to tooth surface. materials and methods: eighty intact premolars were randomly divided into four groups of 20.  after bonding a bracket on each tooth, the groups one to four were stored in artificial saliva at a ph of 3.8, 4.8, 5.8, and 6.8, respectively for ...