Time filter

Source Type

Tbilisi, Georgia

Adamashvili G.T.,The University of Georgia
Results in Physics | Year: 2011

A theory of an optical vector soliton of self-induced transparency (SIT) is constructed. By using the perturbative reduction method the equations of SIT for the small area pulse are reduced to the two-component coupled nonlinear Schrödinger equations. The shape of optical double periodic vector soliton with the sum and difference of the frequencies is presented. Explicit analytic expressions for the parameters of the 0π vector pulse of SIT are obtained. It is shown that the vector soliton in this special case can be reduced to the double breather solution of SIT and these nonlinear waves present different profiles. © 2011 Elsevier B.V.

Adamashvili G.T.,The University of Georgia
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2015

A theory of an optical resonance vector pulsing soliton in waveguide is developed. A thin transition layer containing semiconductor quantum dots forms the boundary between the waveguide and one of the connected media. Analytical and numerical solutions for the optical vector pulsing soliton in waveguide are obtained. The vector pulsing soliton in the presence of excitonic and bi-excitonic excitations is compared with the soliton for waveguide TM-modes with parameters that can be used in modern optical experiments. It is shown that these nonlinear waves have significantly different parameters and shapes. © 2014 Elsevier B.V. All rights reserved.

Using of mutislice spiral CT as first line examination for the diagnosis of Acute Facial trauma in the setting of Polytrauma reduces both: valuable time and cost of patient treatment. After a brief clinical examination, MDCT was performed depending on the area of injury, using a slice thickness of 0.65 mm. The obtained data were analyzed using 3D, MIP and Standard axial with Bone reconstruction protocols. 64 polytrauma patients were evaluated with both Anterior and Lateral craniography (plain skull X ray: AP and Lateral) and Multi Slice CT. Craniography detected only 18 cases of traumatic injuries of facial bones, but exact range of dislocation and accurate management plan could not be established. In the same 64 cases, Multislice CT revealed localization of all existed fractures, range of fragment dislocation, soft tissue damage and status of Paranasal sinus in 62 cases (96.8%). In two cases MS CT missed the facial fracture, in one case the examination was complicated because of bone thinness and numerous fracture fragments, in another multiple foreign body artifacts complicated the investigation. The study results show that, CT investigation based on our MDCT polytrauma protocol, detects all more or less serious facial bone injuries.

Adamashvili G.T.,The University of Georgia
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2016

A theory of acoustic vector solitons of self-induced transparency of the Rayleigh wave is constructed. A thin resonance transition layer on an elastic surface is considered using a model of a two-dimensional gas of impurity paramagnetic atoms or quantum dots. Explicit analytical expressions for the profile and parameters of the Rayleigh vector soliton with two different oscillation frequencies is obtained, as well as simulations of this nonlinear surface acoustic wave with realistic parameters, which can be used in acoustic experiments. It is shown that the properties of a surface vector soliton of the Rayleigh wave depend on the parameters of the resonance layer, the elastic medium, and the transverse structure of the surface acoustic wave. © 2016 American Physical Society.

Attention deficit/hyperactivity disorder (ADHD) is one of the most widely spread condition of school aged children affecting 5% of children of this age. The unified consensus of the precise diagnosis of this condition is still absent. This fact encourages the researchers to seek the alternative neurometric tools which will help the clinicians in diagnosis making process of ADHD. The neurophysiologic approaches especially event-related potentials (ERPs) are mostly important from this point of view. The later response of ERPs (P3) reflects the most important parts of executive functioning frequently affected in ADHD children - the process of mental effortfullness to select the appropriate behavior and decision making. Besides the diagnosis the treatment of ADHD is also the point of concern of neurologists and neurophyschologists. In recent years EEG biofeedback ( Neurofeedback-NF) have become the alternative treatment as in some cases pharmacological drugs are non effective. The positive impact of NF was based on improvement detected by various questionnaires which are less valid but its effectiveness on ERPs parameters is still unknown. Thus we aimed to study the changes of ERPs after NF therapy. We have studied 93 children with ADHD of combined subtype (ADHDcom) without any kind of pharmacological treatment. Age range 9-12 years. The children were divided into two subgroups: The first ADHDcom-1 (48 children) were children where NF treatment was carried out and the second subgroup of ADHDcom-2 (45 children) were non treated children. We have observed statistically significant improvement of parameters of later response like P3 in ADHD-1 compared with ADHD-2 whereas NF was non effective for earlier component like N1. NF can positively affect on the P3 parameters which is very important in ADHD children as P3 reflects the speed of information processing as well as selection of appropriate action and decision making which are frequently affected in ADHD children.

Discover hidden collaborations