Triplet-singlet conversion in ultracold Cs2_2 and production of ground state molecules

We propose a process to convert ultracold metastable Cs$_2$ molecules in their lowest triplet state into (singlet) ground state molecules in their lowest vibrational levels. Molecules are first pumped into an excited triplet state, and the triplet-singlet conversion is facilitated by a two-step spontaneous decay through the coupled $A^{1}\Sigma_{u}^{+} \sim b ^{3}\Pi_{u}$ states. Using spectroscopic data and accurate quantum chemistry calculations for Cs$_2$ potential curves and transition dipole moments, we show that this process has a high rate and competes favorably with the single-photon decay back to the lowest triplet state. In addition, we demonstrate that this conversion process represents a loss channel for vibrational cooling of metastable triplet molecules, preventing an efficient optical pumping cycle down to low vibrational levels

Preparing of Grätzel solar cell

Bakalárska práca rieši problematiku farbivami senzibilizovaných solárnych článkov. Práca uvádza princíp fungovania týchto článkov. Ďalej rozoberá použitie rôznych typov farbív, protielektród, elektrolytov a vodivých skiel. Práca obsahuje tiež princípy merania účinnosti solárnych článkov. V práci sa tiež rozoberá spôsob výroby daných článkov. Praktická časť je zameraná na výrobu prototypov článkov a meranie ich parametrov.This bachelor thesis focuses on the problematic of the dye-sensitized solar cells. The thesis states the working principle of these cells. It also deals with the use of different types of dyes, counterelectrodes, electrolytes and conducting glass. The thesis also contains the principles used in measuring the effectivity of solar cells. The manufacturing process of these cells is described in this thesis. The practical part of the thesis is focused on the manufacture of cell prototypes and the measuring of their parameters.

Control of DC Servo Drive

Tato práce pojednává o návrhu kaskádního řízení servomechanismu se stejnosměrným motorem. Je zde řešen návrh jednotlivých regulátorů tedy regulátoru polohy, otáček a proudu. Dále se zabývá implementací algoritmů PS a PSD regulátoru na mikroprocesoru.This work deals with the proposal of cascade control of the DC servo motor. This work solve proposal of position regulators, angular velocity regulators and current regulators. Futhermore this work deals with the implementation of an algorithms of discrete PI and PID regulators on microprocessor.

Work in Motion / Assessment at Rest: An Attitudinal Study of Academic Reference Librarians A Case Study At Mid-Size University (MSU A)

It is reasonable to assume the existence of a new "dynamic" that influences how to measure reference services in libraries and how we evaluate the reference librarians who provide those services. Traditional, face-to-face delivery of reference services is reported to be declining, and there is myriad evidence, albeit largely uncollated and little evaluated, that suggests reference librarians are delivering significant and increasing amounts of the services they render in network environments. These trends raise questions, in turn, about how well we understand the current state of affairs in reference services, particularly where the management and evaluation of reference services in network environments are concerned. The purpose of this study is to investigate relevant circumstances and conditions bearing -- directly and indirectly -- on changes in the nature, form, substance, and effects of reference services -- through the reference librarian experience. Specifically, this attitudinal study will account for and assess changes in reference services (in the context of a medium-sized private university with a national reputation for successfully integrating information technologies into the educational process), with the further aim of developing an understanding of how to capture statistics and evaluate reference services and personnel in this dynamic environment. Reference librarians at a second mid-sized public university library were also interviewed for comparative data analysis in this study

Assays for mitotic chromosome condensation in live yeast and mammalian cells

The dynamic reorganization of chromatin into rigid and compact mitotic chromosomes is of fundamental importance for faithful chromosome segregation. Owing to the difficulty of investigating this process under physiological conditions, the exact morphological transitions and the molecular machinery driving chromosome condensation remain poorly defined. Here, we review how imaging-based methods can be used to quantitate chromosome condensation in vivo, focusing on yeast and animal tissue culture cells as widely used model systems. We discuss approaches how to address structural dynamics of condensing chromosomes and chromosome segments, as well as to probe for mechanical properties of mitotic chromosomes. Application of such methods to systematic perturbation studies will provide a means to reveal the molecular networks underlying the regulation of mitotic chromosome condensatio

Parallel ion strings in linear multipole traps

Additional radio-frequency (rf) potentials applied to linear multipole traps create extra field nodes in the radial plane which allow one to confine single ions, or strings of ions, in totally rf field-free regions. The number of nodes depends on the order of the applied multipole potentials and their relative distance can be easily tuned by the amplitude variation of the applied voltages. Simulations using molecular dynamics show that strings of ions can be laser cooled down to the Doppler limit in all directions of space. Once cooled, organized systems can be moved with very limited heating, even if the cooling process is turned off

Photodetachment of cold OH- in a multipole ion trap

The absolute photodetachment cross section of OH- anions at a rotational and translational temperature of 170K is determined by measuring the detachment-induced decay rate of the anions in a multipole radio-frequency ion trap. In comparison with previous results, the obtained cross section shows the importance of the initial rotational state distribution. Using a tomography scan of the photodetachment laser through the trapped ion cloud, the derived cross section is model-independent and thus features a small systematic uncertainty. The tomography also yields the column density of the OH- anions in the 22-pole ion trap in good agreement with the expected trapping potential of a large field free region bound by steep potential walls.Comment: Phys. Rev. Lett., in pres