Localization in a strongly disordered system: A perturbation approach

We prove that a strongly disordered two-dimensional system localizes with a localization length given analytically. We get a scaling law with a critical exponent is $\nu=1$ in agreement with the Chayes criterion $\nu\ge 1$. The case we are considering is for off-diagonal disorder. The method we use is a perturbation approach holding in the limit of an infinitely large perturbation as recently devised and the Anderson model is considered with a Gaussian distribution of disorder. The localization length diverges when energy goes to zero with a scaling law in agreement to numerical and theoretical expectations.Comment: 5 pages, no figures. Version accepted for publication on International Journal of Modern Physics

Charge sensitivity of radio frequency single-electron transistor (RF-SET)

A theoretical analysis of the charge sensitivity of the RF-SET is presented. We use the ``orthodox'' approach and consider the case when the carrier frequency is much less than $I/e$ where $I$ is the typical current through RF-SET. The optimized noise-limited sensitivity is determined by the temperature $T$, and at low $T$ it is only 1.4 times less than the sensitivity of conventional single-electron transistor.Comment: 3 pages, 4 figure

Absorptive Capacity in Practice-Based Innovation Activities: the Case of Lahti Region, Finland

As a consequence of for example agglomeration economies, features such as good reputation and highly-skilled labour force tend to accumulate in university regions. The accumulation of highly-skilled labour and high research intensity secure a continuous flow of “raw-material†for innovations in the knowledge-based economy. However, in the regions lacking a university it is vitally important to find other ways of increasing innovation activity. Through implementation of non-linear innovation activity which combines knowledge of normal practice-based activities and science-based research, a region can create radically new perspectives of operating. The new theories of innovation suggest that a great potential of innovation exists in the structural holes and weak links of the innovation system. The new sources of innovation set demands for the innovating partners. In order to exploit the hidden potential in the innovation system the actors of the region must possess, for example, high absorptive capacity, tolerance for diversification and especially the bridging elements of social capital. The Lahti Region in Finland is one of the regions lacking strong regional research base. Determined to create a new source of competitive advantage, the Lahti Region is heading towards a vision of being a top region in promoting practice-based innovation activities. Therefore, the region has created a new policy framework to achieve the vision: network-facilitating innovation policy. The policy aims to promote networked innovation processes especially by exploiting the potential of the structural holes of the innovation system and linking the research-based knowledge from neighbouring strong research centres in the regional innovation processes. This paper examines the readiness of the regional actors to face the demands of the new policy framework. The case study is a compilation of 12 interviews of the key persons in the regional development field and a survey study among representatives of companies, educational and research organizations as well as public organizations.

Perturbative QCD at high density

Cold quark matter is matter consisting of free quarks in high energy density, and it can be formed when the energy density of ordinary hadronic matter increases to a region of 1 GeV/fm3. At such high energies, hadronic matter undergoes a phase transition and quarks that would normally be in color confinement break free to form a new phase. It is assumed that similar process happened in the very early universe, but in the opposite direction, when high temperature quark-gluon plasma cooled down significantly. With the cooling, the quark and gluon degrees of freedom switched to hadrons and ordinary matter began to form. Opposed to the hot quark-gluon plasma, there are no direct observations of cold quark matter and its existence is still speculative. Still, it is suspected that cold quark matter can be found in dense neutron star cores or even as stable quark matter in strange quark stars. Theoretically, cold quark matter and quark-gluon plasma can be studied in finite-temperature field theory. Finite-temperature field theory combines the field formalism of quantum field theory and the thermodynamical and statistical methods utilized in quantum statistics. The asymptotic freedom of the theory of strong interactions, quantum chromodynamics (QCD), provides an opportunity to expand the equation of state of high-energy quark matter in the limit of weak coupling, and thus opens a door to implement the tools of finite-temperature field theory perturbatively. Along with the perturbative analysis, it is useful to look at the possibilities offered by effective theories. Two of which are important in the study of finite-temperature QCD, dimensional reduction and hard thermal loop effective theory. Both effective theories address the issue of infrared divergences that arise in finite-temperature field theory efficiently compared to the naïve loop expansion. In dimensional reduction, scales that are defined as hard by the scale hierarchy are integrated out of the theory, after which the infrared problems of gluonic Matsubara zero-modes can be studied in a simpler three-dimensional setting. Hard thermal loop effective theory, on the other hand, examines the infrared divergences that appear in loop-level corrections of soft gluons. When the magnitude of the loop-momentum corresponds to the hard scale, the correction that contains the loop becomes proportional to a tree-level amplitude and breaks the perturbative expansion. The effective theory answers this problem by resumming the propagators and vertex functions and using the new quantities in place of the ordinary ones. With perturbation theory and the effective descriptions, the equation of state of cold quark matter and the pressure extracted from it, have been solved partially up to and including order g6ln2g2 in coupling. The meaning of this thesis is to present the methods of finite-temperature field theory and the supporting effective theories and their implementation to study the equation of state of cold quark matter. The results for QCD pressure will be presented to the last known order in coupling. Also, the effect of a massive strange quark and the role of cold quark matter in solving the neutron star equation of state will be discussed briefly

Electronic customer relationship management : Business needs analysis for concept development in a telecommunications company

Siirretty Doriast

Setup for shot noise measurements in carbon nanotubes

We have constructed a noise measurement setup for high impedance carbon nanotube samples. Our setup, working in the frequency range of 600 - 900 MHz, takes advantage of the fact that the shot noise power is reasonably large for high impedance sources so that relatively large, fixed non-matching conditions can be tolerated.Comment: 2 pages, 2 figures, published on AIP conference proceedings 200

Health behaviour among Lithuanian adult population, 2006

Book describes data on national 25-64 year lithuanians health behaviour survey starting from 1994 every other year. Book would be useful for people who work in scientific research in social health, medical, social science area, health policy formating and materializing structures. Data presented in this book could be interesting and beneficial for biomedical and social sciences students, social health, family medicine, management specialists for preparing their master‘s and PhD