Reconfigurable wideband patch antenna for cognitive radio

Cognitive radio communication is envisaged to be a new paradigm of methodologies for enhancing the performance of radio communication systems through the efficient utilization of radio spectrum. A key enabler for realization of a cognitive communication system is the capability of re-configurability in the underlying hardware and the associated protocol suite. Reconfigurable double C-Slot microstrip patch antenna fed by 50 ohm microstrip line is proposed in this paper. The frequency tuning is performed by switching on and off two patches. The antenna can operate in dual-band or in very wide band mode in 5, 6 and 7 GHz bands. The wide-band mode can be obtained when both switches are in the ON state with impedance bandwidth of 33.52 % from 4.99 to 7 GHz. The total size of the ground plane is 50 x 50 mm2. The proposed antenna verified through both numerical simulation and measurement of an experimental prototype. The antenna achieves a gain of 5 to 8 dBi and radiation efficiency about 80%

Impulse Response with Correlation Study of a Broadband Bended Wearable Monopole Antenna

In this paper, the impulse response of a wide band flexible circular monopole antenna is presented. The antenna is fabricated on liquid crystalline polymer flexible substrate with a compact geometry that makes it suitable for wearable applications under different bending conditions. The antenna is fed by coplanar waveguide transmission line and has a compact total size of 40 × 22 mm2. The presented antenna has a good performance over the operating frequency range for straight and bent configurations. The design principals, simulation and experimental results are presented in this work

Thermal extras of vegetation walls in Belgrade climatic conditions

The goal of this research is to analyse the possibility of using vegetation walls in order to improve the thermal characteristics of office buildings in Belgrade's climatic conditions. The study analyses the possibility of integrating vegetation modules into the fa ades of office buildings. The paper shows the potential of vegetation technologies in the realisation offacade coverings of architectural buildings with a goal to reduce heat gained during summer time. The use of vegetation walls in architecture has opened up new planning possibilities and created planning conditions for reducing the energy necessary for cooling office buildings. Considering that interaction between the outer environment and inner solving the dependency between comfort, outer look and building's energy balance. This paper is presenting the possibility of using sustainable technologies for solving the problem of overheating in Belgrade's climatic conditions. The research considers the possibilities of using vertically greening systems in planning facade coverings, with an analysis of their thermal characteristics for climatic conditions in Belgrade

The role of the central limit theorem in the heterogeneous ensemble of Brownian particles approach

The central limit theorem (CLT) and its generalization to stable distributions have been widely described in literature. However, many variations of the theorem have been defined and often their applicability in practical situations is not straightforward. In particular, the applicability of the CLT is essential for a derivation of heterogeneous ensemble of Brownian particles (HEBP). Here, we analyze the role of the CLT within the HEBP approach in more detail and derive the conditions under which the existing theorems are valid

Iridium anomaly in the cretaceous-paleogene boundary at Højerup (Stevns Klint, Denmark) and Woodside Creek (New Zealand): The question of an enormous proportion of extraterrestrial component

The Cretaceous-Paleogene boundary clays at Højerup and Woodside Creek show anomalous enrichments of iridium compared with the marine sedimentary rocks. For the average iridium content of 465 ppb in CI chondrite the estimate of the carbonaceous chondritic proportions in the decarbonated iridium-rich boundary layers, based on the integrated iridium fluencies, is about 26% at Højerup and 65% at Woodside Creek. These proportions are most likely too high due to a significant Ir influx from the nearby marine or continental site to these sections

Structure and Dynamics of Sheep Systems in Bosnia and Herzegovina

The paper presents the analysis of dynamics and structure of the sheep systems in Bosnia and Herzegovina assuming that they suffered a decrease of animal and farms consistency in the last 6 decades. Since 1991 neither a general nor agricultural censuses were made to provide information about the present state of sheep farming in the country. An analysis of the available statistical records of agricultural trends related to the sheep sector was performed. In addition, a depth questionnaire by consulting national experts was performed in order to obtain relevant information on the spatial distribution, consistency, feeding management, production and environmental impact on the present structure of sheep production systems. A decrease in sheep number was observed over the last six decades, but less than in other species. Six main sheep systems in three biogeographical regions were identified. Differences in animal spatial distribution, production purpose and other characteristics of the systems indicate that the environmental and socio-economic factors throughout the country strongly influence the choice of breeding methods and management. All consulted experts indicated the lack of support for sheep systems in relation to agro environmental management, landscape conservation and biodiversity preservation

Dissipative neutrino oscillations in randomly fluctuating matter

The generalized dynamics describing the propagation of neutrinos in randomly fluctuating media is analyzed: it takes into account matter-induced, decoherence phenomena that go beyond the standard MSW effect. A widely adopted density fluctuation pattern is found to be physically untenable: a more general model needs to be instead considered, leading to flavor changing effective neutrino-matter interactions. They induce new, dissipative effects that modify the neutrino oscillation pattern in a way amenable to a direct experimental analysis.Comment: 14 pages, plain-Te

Techno-economic analysis of heat exchangers with parallel helical tube coils

U radu su prikazani investicijski i eksploatacijski troškovi kod bubnjastih izmjenjivača topline s paralelnim zavojnim cijevima. Provedena je statistička analiza najčešće rabljenih korelacija iz otvorenih literaturnih izvora za određivanje cijena bubnjastih izmjenjivača topline s tržišnim podacima aparata s kojom je utvrđeno da pokazuju značajna odstupanja i da se ne mogu s dovoljnom pouzdanošću koristiti za navedeni tip aparata. Uspostavljena je nova korelacija za procjenu cijena aparata sa zavojnim cijevima (za slučaj kada je omotač aparata izrađen od ugljičnog čelika, a cijevni snop od bakra). Procijenjeni su troškovi električne energije za pogon pumpi kao i troškovi kemijskog čišćenja aparata inhibiranom klorovodičnom i sumpornom kiselinom.The paper deals with the investment and exploitation costs for shell and tube heat exchangers with parallel helical tube coils. The most common correlations for estimating prices of shell and tube heat exchangers found in open literature were tested using the market data for a comparison and they have shown significant deviations. A new correlation for calculating prices of heat exchangers with helical tubes (when the shell is made of carbon steel and the helical tube of copper) was determined. In addition, the costs of electricity needed to drive pumps, as well as the costs of chemical cleaning of the apparatuses with inhibited mineral acids were estimated

Complete positivity and entangled degrees of freedom

We study how some recently proposed noncontextuality tests based on quantum interferometry are affected if the test particles propagate as open systems in presence of a gaussian stochastic background. We show that physical consistency requires the resulting markovian dissipative time-evolution to be completely positive.Comment: 23 pages, plain-TeX, no figure

Veterinarski informacioni menadžment sistem (VIMS) u procesu prijavljivanja i menadžmenta zaraznih bolesti

A prerequisite to the development of an efficient animal health, food safety and traceability management system in the animal food production chain is the implementation of an integrated veterinary informational management system (VIMS) capable for the capture, storage, analysis and retrieval of data and providing the opportunity for the cumulative gathering of the knowledge and capability for its competent interpretation. Such a system will enable collecting appropriate data, including quality management and inspection controls, from all establishments and commodities in the 'from farm to fork' food production chain (farms, holdings, slaughterhouses, laboratories, traders etc.) in a structured, predefined format, and facilitate competent analyses and reporting of such data, as well as the improvement of the existing programs and strategies. The role of information system in animal disease diagnosis, surveillance and notification, control of national and international trade of commodities, food safety management, investigation of diseases, predictive microbiology and quantitative risk assessment is of great importance for the quality of veterinary service. Integral part of the VIMS is animal disease notification system designed according to and in compliance with international requirements, standards and recommendation and able to exchange relevant information with similar information systems. The aim of this contribution is to describe national animal disease notification system which is in place in Serbia as a part of VIMS.Preduslov za uspostavljanje efikasnog sistema menadžmenta zdravstvene zaštite životinja, bezbednosti hrane i sledljivosti u lancu proizvodnje hrane je uvođenje integrisanog veterinarskog informacionog menadžment sistema (VIMS) razvijenog na takav način da omogući prikupljanje, čuvanje, analizu i povlačenje podataka i obezbedi kumulativno skupljanje saznanja i njihovu stručnu interpretaciju. Takav sistem će omogućiti prikupljanje podataka, uključujući one iz upravljanja kvalitetom i u okviru inspekcijskih kontrola, od svih objekata u sistemu proizvodnje hrane 'od farme do viljuške' (farme, gazdinstva, klanice, laboratorije, lica koja se bave prometom i dr.) u strukturirano, unapred definisanom obliku, i obezbediti kompetentnu analizu takvih podataka kao i unapređenje postojećih programa i strategija. Uloga informacionih sistema u dijagnostici, nadzoru i prijavljivanju zaraznih bolesti, kontroli unutrašnjeg i međunarodnog prometa, upravljanju bezbednošću hrane, istraživanju žarišta zaraznih bolesti, prediktivnoj mikrobiologiji i kvantitativnoj analizi rizika je od izuzetnog značaja za kvalitet veterinarske službe. Sastavni deo VIMS-a je sistem za prijavljivanje zaraznih bolesti dizajniran prema i u saglasnosti sa međunarodnim zahtevima, standardima i preporukama i osposobljen da vrši razmenu određenih podatka sa sličnim informacionim sistemima. Cilj ovog rada je da se opiše nacionalni sistem za prijavljivanje zaraznih bolesti koji je u Srbiji u primeni kao deo VIMS-a