Context.
Spitzer
/IRAC color selection is a promising technique to identify hot accreting nuclei, that is, active galactic nuclei (AGN), in galaxies. We demonstrate this using a small sample of ...SAURON galaxies and then explore this technique further.
Aims.
The goal of this study is to find a simple and efficient way to reveal optically obscured nuclear accretion in (nearby) galaxies.
Methods.
We applied an infrared selection method to the
Spitzer
Survey of Stellar Structures in Galaxies (S
4
G) sample of more than 2500 galaxies, together with its extension sample of more than 400 galaxies. We used the
Spitzer
colors to find galaxies in the S
4
G survey containing a hot core, suggesting the presence of a strong AGN, and we studied the detection fraction as a function of morphological type. We tested this infrared color selection method by examining the radio properties of the galaxies via the VLA NVSS and FIRST surveys.
Results.
Using the radio data, we demonstrate that galaxies displaying hot mid-infrared nuclei stand out as (candidate) active galaxies. We reproduce these results when using colors from the lower spatial resolution WISE mission instead of
Spitzer
. Hence multiband infrared imaging represents a useful tool to uncover optically obscured nuclear activity in galaxies.
Investigations have suggested that poor compliance could be an indicator of poor relationship with family and could be related to the person's personality traits.
The aim of this study was to ...determine the effect of parents attitude, the anxiety during treatment and self-confidence/self-care of the patient on cooperation during orthodontic treatment.
The study material consisted of questionnaires completed by 82 adolescent patients and their parents. The patients were divided into two groups of 42 compliant and 40 non-compliant patients. The above-mentioned questionnaires were State-Trait Anxiety Inventory-STAI, Piers-Harris Children's Self Concept Scale and The Exercise of Self-Care Agency for the patients and Mc Master Family Assessment Device and Parental Attitude Research Instrument-PARI for the parents.
The problem solving and caring attitude of the father and his determinative role in the family had a positive influence on the compliance of the child. The patients who showed better compliance also had a lower state of anxiety, which could also be explained by the positive effect of the attitude of the father in the family.
It would be useful to overcome the increased state of anxiety of the child in the orthodontic clinic by using educational and relaxation techniques. Besides, it would be wise to ask the father to be present at the first appointment during part of the education of the child.
This study investigates an effective method for solving one class of integral equations. It addresses various two dimensional problems related to do diffraction theory by metal screens, which are ...reduced to these integral equations. A novel approach for solving this class of integral equations is proposed. The study foceses on investigating diffraction on a strip using a combination of analytical and numerical methods and the results are obtained through simulation. Keywords: Fractional boundary condition, electromagnetic diffraction, fractional strip, integral equation, fractional calculus. AMS Subject Classification: 35J05, 35A35, 45L05, 45E99
Wedge is an important canonical structure in diffraction theory, a two-impedance wedge in a cold plasma may practically be used in modeling the electromagnetic scattering from a variety of large and ...complex objects. In this study, the scattered field is represented in the form of a
Sommerfeld integral with an unknown spectral function. By using the impedance boundary conditions a nonhomogeneous functional equation is obtained. The solution of the functional equation is represented in terms of χ-functions and S integrals. After determining the unknown spectral
function in the Sommerfeld integral, the Sommerfeld contour is deformed into the steepest descent path to derive the expression of the diffraction coefficients.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The problem of diffraction of a plane wave incident on a thin semi-infinite chiral slab is solved in an explicit form and the effect of chirality on diffraction phenomenon is investigated for the ...first time. The thin layer is simulated by appropriate coupled transition boundary conditions
of the first order with respect to the thickness of the slab. Application of the law of conservation of energy enables us to prove the uniqueness of the solution and to give some sufficient conditions for the parameters of the problem securing the unique solvability. The problem in question
is solved by means of the Sommerfeld integrals and by some minor modification of the Maliuzhinetz technique. The asymptotics of the far field is studied and some numerical results for the diffraction coefficients are discussed.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In this study, the diffraction of a plane wave by an infinitely long strip, having the same impedance on both faces with a width of 2a is investigated. The diffracted field is expressed by an ...integral in terms of the induced electric and magnetic current densities. Applying the boundary
condition to the integral representation of the scattered field, the problem is formulated as simultaneous integral equations satisfied by the electric and magnetic current density functions. By obtaining the Fourier transform of the integral equations the unknown current density functions
can be expanded into the infinite series containing the Chebyshev polynomials. This leads to two infinite systems of linear algebraic equations satisfied by the expansion coefficients. These coefficients are determined numerically with high accuracy via appropriate truncation of the systems
of linear algebraic equations. Evaluating the scattered field asymptotically, a far field expression is derived. Some illustrative numerical examples on the monostatic and bistatic radar cross section (RCS) are presented and the far field scattering characteristics are discussed.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A microprocessor-controlled direction selectable TV receiving antenna providing maximum signal strength from multiple direction TV sources is reported. The system has many desirable features, such as ...a 24-h format digital clock, single step control for fine direction adjustment, display of time and direction in seven-segment LEDs, real-time direction changing for any desired angle, a bar graph display indicating the signal strength, and a programmed off-time direction setting.< >
A receive sum tracking antenna system that continuously tracks a TV satellite is proposed. The receiving parabolic antenna is fixed with auxiliary arrays for picking up the off-axis signals. A ...microprocessor processes the received signals and controls X-Y stepper motors so as to adjust the orientation direction of the antenna.< >
PDF
