In this paper, the transverse vibrations of rectangular plate with circular central hole have been investigated and the natural frequencies of the mentioned plate with point supported by Rayleigh-Ritz Method have been obtained. In this research, the effect of the hole is taken into account by subtracting the energies of the hole domain from the total energies of the whole plate. To determine th...

In this research, the effects of the rotational speed, feed rate, tool material and lubricants on the tool life and the hole quality are studied in the frictional drilling of the titanium sheets. The friction drilling tests are performed on a CNC milling machine. Furthermore, 5 specimens are selected and their metallurgical structures are studied. The results show thatamong the input parameters...

Abstract Recently, an analytical study of radial and circular orbits for null time-like geodesics that propagate in the spacetime produced by a Schwarzschild black hole associated with cloud strings, universe filled quintessence, has been done Mustafa Hussain (Eur Phys J C 81:419, 2021). In this paper, we complete aforementioned investigating possible solutions to equations motion other types b...

in this study, the effect of hole mulching application of zn and mn on acacia, elm, and plane nutrition was examined in the green spaces of isfahan. three different sites were chosen in a randomized complete block design using six treatments of: 1. cow manure compost, 2. cow manure vermicompost, 3. urban waste compost, 4. urban waste vermicompost, 5. dug hole refilled with the same soil coming ...

Elliptic curve cryptosystems([19, 25]) are based on the elliptic curve discrete logarithm problem(ECDLP). If elliptic curve cryptosystems avoid FR-reduction([11, 17]) and anomalous elliptic curve over Fq ([34, 3, 36]), then with current knowledge we can construct elliptic curve cryptosystems over a smaller de nition eld. ECDLP has an interesting property that the security deeply depends on elli...

Elliptic curve cryptosystems([19],[25]) are based on the elliptic curve discrete logarithm problem(ECDLP). If elliptic curve cryptosystems avoid FRreduction([11],[17]) and anomalous elliptic curve over Fq ([3], [33], [35]), then with current knowledge we can construct elliptic curve cryptosystems over a smaller definition field. ECDLP has an interesting property that the security deeply depends...

One of the fundamental problems in numerically constructing spacetimes without symmetries (3D numerical relativity) is the choice of suitable coordinates. The task is not just to find a good coordinate system for a known spacetime, but the spacetime is not actually known when the calculation begins, so that one has to construct the coordinate system along with the spacetime. In principle, once ...

abstract saturated hydraulic conductivity (ks) is one of the most important physical properties of soils which is expensive and time-consuming to directly measure. hence, indirect methods, such as pedotransfer functions (ptfs), were developed to predict the ks. previous studies showed that most of the ptfs common in the literature can not suitably predict the ks. hence, this study was conducted...

in this paper, the effects of reflected waves of the facets on the internal optical intensity of semiconductor dfb lasers are investigated. the uniformity of optical intensity along the cavity length is evaluated with flatness parameter. the dependence of this parameter on coupling coefficient, reflectivity and grating phase at the facets is also studied. this investigation shows that in some s...