br Here and V is

Here, and V is the Verdet constant, H is the intensity of the magnetic field strength. The components of stress tensor must satisfy the equilibrium equations. The solution of these equations can be expressed through the stress functions [7,22]. According to the Helmholtz theorem, the two-dimensional vector field defined over xy plane can be represented as a sum of an irrotational (potential) field and of a solenoidal one:
Similarly, a two-dimensional symmetric tensor field defined over a plane xy can be expressed in terms of the three potentials:
The stress functions must satisfy the following equations
Tomographic reconstruction of shear stresses σ in the xy plane, based on the values of the path integral T2, is reduced to determining a 2D vector field and, according to the Helmholtz theorem to finding its solenoidal N and potential τ components. The algorithm of reconstruction of these components in the case of the magnetophotoelasticity was given in [6,7,10] and, the more general case of the attenuated vectorial Radon transform was given in [12,13]. Once the potentials τ and N are known the other stresses can be reconstructed if we find F and σ. Using representation (7), we can transform path integral T1(s, θ, β) by integrating in parts:
Here, T0(s, θ, β) is the function, containing known potentials τ, and N. Thus, by using the measurements at β = 0, and β ≠ 0, we have the system of the ray integrals, which allow one to fully recover the tensor field.
Summary The majority of investigations in the tensor stress field tomography are devoted to isotropic articles. In this paper we demonstrate the opportunities and difficulties of the integrated photoelasticity in the case of cubic single crystals. Reconstruction of the residual stresses in both cases is connected with the solution of the system of equations. In the case of the isotropic model this system can be solved step by step. In the second case the same equations cannot be separated, and they SBI-0206965 should be solved simultaneously. One of the drawbacks of the magnetophotoelasticity is the need for very precise optical measurements since the Faraday effect is very small. The using of multiple reflections is one of the possibilities to overcome this difficulty [23].
Introduction Represented work continues a series of publications aimed at optimizing the light environment for human life in residential and industrial premises. The Refs. [1,2] showed the results of a comprehensive study and optimization of energy-efficient, dynamically controlled LED light sources (EDCLLS) on the basis of new lighting technologies and microelectronic LED and microelectronic base. Standard IEEE 802.15.4, being the basis for a software upgrade [3], was a success, and many manufacturing companies are developing devices based on it. At the same time, products using ZigBee technology are under development, and a number of pilot implementations.
Architecture of IEEE 802.15.4 standard Architecture of IEEE 802.15.4 standard [4,5] defines a stack of levels, each being responsible for one part of the standard and provides service to the above-cited level. PHY in the EDCLLS network performs the following tasks: the idle channel assessment CCA (clear channel assessment) for access mechanisms CSMA-CA (carrier sense multiple access with collision avoidance). This allows to reach low values of the signal-to-noise and signal-to-interference ratios. The main characteristics of the method are the following: a frequency is 2.00 Mchip/s, the data transmission rate is 250 kbit/s, the frequency of symbols is 62.5 × 104 symbols/s, symbols 16-ary are orthogonal; a mean channel frequency (Fm) is where k is a channel number, k = 11–26. The MAC sublayer provides informational MAC-service and a service of control MAC-level; keratinocytes provides an interface of control network and supports database on control objects of the MAC sublayer. Informational MAC service provides reception and transmission of protocol blocks of the MAC level (MPDU) via PHY informational service.