Family house - Heating with Boiler, Photothermics

Tématem této bakalářské práce je řešení a vypracování projektové dokumentace pro rodinný dům se zaměřením na návrh systému vytápění a přípravy teplé vody tohoto objektu. Dům bude využívat jako zdroj tepla kotel na biomasu, konkrétně kusové dřevo, který bude napojen na dvě akumulační nádrže a také zásobník pro přípravu teplé vody. Teplá voda bude moct být připravována také pomocí solárního termického ohřevu, či pomocí elektrického topného tělesa umístěného do zásobníku. Vytápění je navrženo jako teplovodní dvoutrubkový systém s deskovými a trubkovými otopnými tělesy umístěnými ve všech podlažích objektu. Bakalářská práce se skládá z části textové, výkresové a přílohové.The topic of this bachelor thesis is the solution and development of project documentation for a family house with a focus on the design of the heating and hot water system of this building. The house will use a biomass boiler, specifically lump wood, as a heat source, which will be connected to two storage tanks and also a hot water storage tank. The hot water can also be prepared using solar thermal heating or an electric heater placed in the storage tank. The heating system is designed as a hot water two-pipe system with plate and tube heating elements located on all floors of the building. The bachelor thesis consists of text, drawings and appendices.229 - Katedra prostředí staveb a TZBvelmi dobř

Frequency filters with untraditional combination of active elements

Bakalářská práce pojednává o teorii a návrhu analogových kmitočtových filtrů druhého řádu, které pracují v proudovém módu a využívají netradiční kombinace aktivních prvků. Filtry jsou navrženy s využitím metody autonomních obvodů. Aktivní prvky použité při návrhu jsou proudový sledovač MO-CF, proudový zesilovač DACA, zobecněné proudové zrcadlo a invertor GCMI, transkonduktanční zesilovač BOTA, invertující proudový konvejor první a třetí generace ICCI/ICCIII a univerzální napěťový konvejor UVC. Navržené filtry pracují výhradně v proudovém módu a jejich ideální a reálné modely jsou ověřeny v simulačním prostředí OrCadu. Práce je strukturovaná do pěti kapitol včetně závěru. První kapitola uvádí obecné vlastnosti kmitočtových filtrů, typy filtračních funkcí, typy filtrů a důležité obecné vztahy. Ve druhé kapitole se věnuji teorii použitých aktivních prvků, ve třetí pak metodám návrhu a čtvrtá obsahuje vlastní navržené filtry včetně jejich přenosových funkcí a výsledků ověření jejich funkčnosti v simulačním prostředí.The Bachelor’s thesis deals with the theory and designing of analog frequency filters of the second order, which operate in current mode and use the untraditional combination of active elements. The filters are designed by means of the autonomous circuits. Active elements used in the design is Multiple Output Current Follower MO-CF, Digitally Controlled Current Amplifier DACA, Generalized Current Mirror and Inverters GCMI, Balanced Operational Transconductance Amplifier BOTA, Inverting Current Conveyor 1st and 3rd Generation ICCI/ICCIII and Universal Voltage Conveyor UVC. The proposed filters work in current mode and their ideal and real models are verified in the simulation environment OrCad. The thesis is structured into five chapters including the conclusion. The first chapter gives the general characteristics of the frequency filters, types of filter functions, types of filters and general equations. The second chapter is devoted to the theory of the active elements. The third charter is about methods of designing and the fourth includes custom designed filters, including their transfer functions and the results verify their functionality in the simulation environment.

2-kW Average Power CW Phase-Conjugate Solid-State Laser

We have demonstrated stable operation of a 2-kW Yb:YAG phase-conjugate master oscillator power amplifier (PC-MOPA) laser system with a loop phase-conjugate mirror (LPCM). This is the first demonstration of a continuous wave (CW)-input LPCM MOPA operating at a power greater than 1 kW with a nearly diffraction-limited output beam. The single-pass beam quality incident on the LPCM varied with the specific operating conditions, but it was typically ${sim}20$ times diffraction-limited (XDL). The measured beam quality with an MOPA output power of 1.65 kW was 1.3 XDL

Clustering of galaxies around GRB sight-lines

There is evidence of an overdensity of strong intervening MgII absorption line systems distributed along the lines of sight towards GRB afterglows relative to quasar sight-lines. If this excess is real, one should also expect an overdensity of field galaxies around GRB sight-lines, as strong MgII tends to trace these sources. In this work, we test this expectation by calculating the two point angular correlation function of galaxies within 120$^{\prime\prime}$ ($\sim470~h_{71}^{-1}~\mathrm{Kpc}$ at $\langle z\rangle \sim0.4$) of GRB afterglows. We compare the Gamma-ray burst Optical and Near-infrared Detector (GROND) GRB afterglow sample -- one of the largest and most homogeneous samples of GRB fields -- with galaxies and AGN found in the COSMOS-30 photometric catalog. We find no significant signal of anomalous clustering of galaxies at an estimated median redshift of $z\sim0.3$ around GRB sight-lines, down to $K_{\mathrm{AB}}<19.3$. This result is contrary to the expectations from the MgII excess derived from GRB afterglow spectroscopy, although many confirmed galaxy counterparts to MgII absorbers may be too faint to detect in our sample -- especially those at $z>1$. We note that the addition of higher sensitivity Spitzer IRAC or HST WFC3 data for even a subset of our sample would increase this survey's depth by several orders of magnitude, simultaneously increasing statistics and enabling the investigation of a much larger redshift space.}Comment: 10 pages, 6 figures. A&A accepte

Energetic Fermi/LAT GRB100414A: Energetic and Correlations

This study presents multi-wavelength observational results for energetic GRB100414A with GeV photons. The prompt spectral fitting using Suzaku/WAM data yielded spectral peak energies of E^src_peak of 1458.7 (+132.6, -106.6) keV and Eiso of 34.5(+2.0, -1.8) x 10^52 erg with z=1.368. The optical afterglow light curves between 3 and 7 days were effectively fitted according to a simple power law with a temporal index of alpha=-2.6 +/- 0.1. The joint light curve with earlier Swift/UVOT observations yields a temporal break at 2.3 +/- 0.2 days. This was the first \fermi/LAT detected event that demonstrated the clear temporal break in the optical afterglow. The jet opening angle derived from this temporal break was 5.8 degree, consistent with those of other well-observed long gamma-ray bursts (GRBs). The multi-wavelength analyses in this study showed that GRB100414A follows E^src_peak-Eiso and E^src_peak-E_gamma correlations. The late afterglow revealed a flatter evolution with significant excesses at 27.2 days. The most straightforward explanation for the excess is that GRB100414A was accompanied by a contemporaneous supernova. The model light curve based on other GRB-SN events is marginally consistent with that of the observed lightcurve.Comment: ApJL in press; 12 pages, 3 figures, 2 table

Afterglow rebrightenings as a signature of a long-lasting central engine activity? The emblematic case of GRB 100814A

In the past few years the number of well-sampled optical to NIR light curves of long Gamma-Ray Bursts (GRBs) has greatly increased particularly due to simultaneous multi-band imagers such as GROND. Combining these densely sampled ground-based data sets with the Swift UVOT and XRT space observations unveils a much more complex afterglow evolution than what was predicted by the most commonly invoked theoretical models. GRB 100814A represents a remarkable example of these interesting well-sampled events, showing a prominent late-time rebrightening in the optical to NIR bands and a complex spectral evolution. This represents a unique laboratory to test the different afterglow emission models. Here we study the nature of the complex afterglow emission of GRB 100814A in the framework of different theoretical models. Moreover, we compare the late-time chromatic rebrightening with those observed in other well-sampled long GRBs. We analysed the optical and NIR observations obtained with the seven-channel Gamma-Ray burst Optical and Near-infrared Detector at the 2.2 m MPG/ESO telescope together with the X-ray and UV data detected by the instruments onboard the Swift observatory. The broad-band afterglow evolution, achieved by constructing multi-instrument light curves and spectral energy distributions, will be discussed in the framework of different theoretical models. We find that the standard models that describe the broad-band afterglow emission within the external shock scenario fail to describe the complex evolution of GRB 100814A, and therefore more complex scenarios must be invoked. [abridged]Comment: 11 pages, 7 figures, 2 tables; Astronomy & Astrophysics, in pres

The bright optical/NIR afterglow of the faint GRB 080710 - Evidence for a jet viewed off axis

We investigate the optical/near-infrared light curve of the afterglow of GRB 080710 in the context of rising afterglows. Optical and near-infrared photometry was performed using the seven channel imager GROND and the Tautenburg Schmidt telescope. X-ray data were provided by the X-ray Telescope onboard the Swift satellite. The optical/NIR light curve of the afterglow of GRB 080710 is dominated by an initial increase in brightness, which smoothly turns over into a shallow power law decay. The initially rising achromatic light curve of the afterglow of GRB 080710 can be accounted for with a model of a burst viewed off-axis or a single jet in its pre deceleration phase and in an on-axis geometry. An unified picture of the afterglow light curve and prompt emission properties can be obtained with an off-axis geometry, suggesting that late and shallow rising optical light curves of GRB afterglows might be produced by geometric effects.Comment: 9 pages, 4 figures, accepted by A and

Multiwavelength analysis of three SNe associated with GRBs observed by GROND

After the discovery of the first connection between GRBs and SNe almost two decades ago, tens of SN-like rebrightenings have been discovered and about seven solid associations have been spectroscopically confirmed to date. Using GROND optical/NIR data and Swift X-ray/UV data, we estimate the intrinsic extinction, luminosity, and evolution of three SN rebrightenings in GRB afterglow light curves at z~0.5. The SNe 2008hw, 2009nz, and 2010ma exhibit 0.80, 1.15, and 1.78 times the optical (r band) luminosity of SN 1998bw, respectively. While SN 2009nz evolves similarly to SN 1998bw, SNe 2008hw and 2010ma show earlier peak times. The quasi-bolometric light curves were corrected for the contribution of the NIR bands using data available in the literature and blackbody fits. The large luminosity of SN 2010ma (1.4x10^43 erg/s) is confirmed, while SNe 2008hw and 2009nz reached a peak luminosity closer to SN 1998bw. Physical parameters of the SN explosions, such as synthesised nickel mass, ejecta mass, and kinetic energy, are estimated using Arnett's analytic approach, which resulted in nickel masses of around 0.4-0.5 Msun. By means of the a very comprehensive data set, we found that the luminosity and the nickel mass of SNe 2008hw, 2009nz, and 2010ma resembles those of other known GRB-associated SNe. This findings strengthens previous claims of GRB-SNe being brighter than type-Ic SNe unaccompanied by GRBs.Comment: 11 pages, 9 figures, accepted for publication in Astronomy & Astrophysics, abstract abridge

GRB 091127: The cooling break race on magnetic fuel

Using high-quality, broad-band afterglow data for GRB 091127, we investigate the validity of the synchrotron fireball model for gamma-ray bursts, and infer physical parameters of the ultra-relativistic outflow. We used multi-wavelength follow-up observations obtained with GROND and the XRT onboard the Swift satellite. The resulting afterglow light curve is of excellent accuracy, and the spectral energy distribution is well-sampled over 5 decades in energy. These data present one of the most comprehensive observing campaigns for a single GRB afterglow and allow us to test several proposed emission models and outflow characteristics in unprecedented detail. Both the multi-color light curve and the broad-band SED of the afterglow of GRB 091127 show evidence of a cooling break moving from high to lower energies. The early light curve is well described by a broken power-law, where the initial decay in the optical/NIR wavelength range is considerably flatter than at X-rays. Detailed fitting of the time-resolved SED shows that the break is very smooth with a sharpness index of 2.2 +- 0.2, and evolves towards lower frequencies as a power-law with index -1.23 +- 0.06. These are the first accurate and contemporaneous measurements of both the sharpness of the spectral break and its time evolution. The measured evolution of the cooling break (nu_c propto t^-1.2) is not consistent with the predictions of the standard model, wherein nu_c propto t^-0.5 is expected. A possible explanation for the observed behavior is a time dependence of the microphysical parameters, in particular the fraction of the total energy in the magnetic field epsilon_B. This conclusion provides further evidence that the standard fireball model is too simplistic, and time-dependent micro-physical parameters may be required to model the growing number of well-sampled afterglow light curves.Comment: accepted to A&A, 13 pages, 5 figure