Vertical pairing of identical particles suspended in the plasma sheath

It is shown experimentally that vertical pairing of two identical microspheres suspended in the sheath of a radio-frequency (rf) discharge at low gas pressures (a few Pa), appears at a well defined instability threshold of the rf power. The transition is reversible, but with significant hysteresis on the second stage. A simple model, which uses measured microsphere resonance frequencies and takes into account besides Coulomb interaction between negatively charged microspheres also their interaction with positive ion wake charges, seems to explain the instability threshold quite well.Comment: 4 pages, 6 figures. to appear in Phys. Rev. Lett. 86, May 14th (2001

Self-consistent model of unipolar transport in organic semiconductor diodes: accounting for a realistic density-of-states distribution

A self-consistent, mean-field model of charge-carrier injection and unipolar transport in an organic semiconductor diode is developed utilizing the effective transport energy concept and taking into account a realistic density-of-states distribution as well as the presence of trap states in an organic material. The consequences resulting from the model are discussed exemplarily on the basis of an indium tin oxide/organic semiconductor/metallic conductor structure. A comparison of the theory to experimental data of a unipolar indium tin oxide/poly-3-hexyl-thiophene/Al device is presented.Comment: 6 pages, 2 figures; to be published in Journal of Applied Physic

Self consistent theory of unipolar charge-carrier injection in metal/insulator/metal systems

A consistent device model to describe current-voltage characteristics of metal/insulator/metal systems is developed. In this model the insulator and the metal electrodes are described within the same theoretical framework by using density of states distributions. This approach leads to differential equations for the electric field which have to be solved in a self consistent manner by considering the continuity of the electric displacement and the electrochemical potential in the complete system. The model is capable of describing the current-voltage characteristics of the metal/insulator/metal system in forward and reverse bias for arbitrary values of the metal/ insulator injection barriers. In the case of high injection barriers, approximations are provided offering a tool for comparison with experiments. Numerical calculations are performed exemplary using a simplified model of an organic semiconductor.Comment: 21 pages, 8 figure

Heavy Scalar Top Quark Decays in the Complex MSSM: A Full One-Loop Analysis

We evaluate all two-body decay modes of the heavy scalar top quark in the Minimal Supersymmetric Standard Model with complex parameters (cMSSM) and no generation mixing. The evaluation is based on a full one-loop calculation of all decay channels, also including hard QED and QCD radiation. The renormalization of the complex parameters is described in detail. The dependence of the heavy scalar top quark decay on the relevant cMSSM parameters is analyzed numerically, including also the decay to Higgs bosons and another scalar quark or to a top quark and the lightest neutralino. We find sizable contributions to many partial decay widths and branching ratios. They are roughly of O(10%) of the tree-level results, but can go up to 30% or higher. These contributions are important for the correct interpretation of scalar top quark decays at the LHC and, if kinematically allowed, at the ILC. The evaluation of the branching ratios of the heavy scalar top quark will be implemented into the Fortran code FeynHiggs.Comment: 86 pages, 38 figures; minor changes, version published as Phys. Rev. D86 (2012) 03501

Economic inequalities in burden of illness, diagnosis and treatment of five long-term conditions in England: panel study

We compared the distribution by wealth of self-reported illness burden (estimated from validated scales, biomarker and reported symptoms) for angina, cataract, depression, diabetes and osteoarthritis, with the distribution of self-reported medical diagnosis and treatment. We aimed to determine if the greater illness burden borne by poorer participants was matched by appropriately higher levels of diagnosis and treatment

Information system for monitoring, estimates and forecastes the main vital parameters of neonatal status

Certain categories of people, as well as newborn babies require constant monitoring signs of their life in hospitals or at home. The most common reason for this observation - apnea. Apnea - a condition accompanied by a lack of respiratory movements for more than 20 seconds. Caused by various factors such as the depletion of blood carbon dioxide caused by excessive ventilation, diseases such as bronchial asthma, various pulmonary diseases, snoring. This observation is particularly relevant for their newborn children. In the light of these provisions, the relevance of this work is evident and the need to address the information system for monitoring vital parameters, estimates and forecasts status of newborns as the problems of the complex. In order to observe these main basic parameters of life, we need a punctual device, which helps monitor newborns, on the one hand and, on the other hand to obtain a correct solution with respect to time in an emergency without the need for specialist or doctor. An artificial intelligence tool, which depends on machine learning, is the best modern method for this kind of information system

The Many Faces of a Character

We prove an identity between three infinite families of polynomials which are defined in terms of `bosonic', `fermionic', and `one-dimensional configuration' sums. In the limit where the polynomials become infinite series, they give different-looking expressions for the characters of the two integrable representations of the affine $su(2)$ algebra at level one. We conjecture yet another fermionic sum representation for the polynomials which is constructed directly from the Bethe-Ansatz solution of the Heisenberg spin chain.Comment: 14/9 pages in harvmac, Tel-Aviv preprint TAUP 2125-9

Self-reported quality of care for older adults from 2004 to 2011: a cohort study

Background: little is known about changes in the quality of medical care for older adults over time. Objective: to assess changes in technical quality of care over 6 years, and associations with participants' characteristics. Design: a national cohort survey covering RAND Corporation-derived quality indicators (QIs) in face-to-face structured interviews in participants' households. Participants: a total of 5,114 people aged 50 or more in four waves of the English Longitudinal Study of Ageing. Methods: the percentage achievement of 24 QIs in 10 general medical and geriatric clinical conditions was calculated for each time point, and associations with participants' characteristics were estimated using logistic regression. Results: participants were eligible for 21,220 QIs. QI achievement for geriatric conditions (cataract, falls, osteoarthritis and osteoporosis) was 41% [95% confidence interval (CI): 38–44] in 2004–05 and 38% (36–39) in 2010–11. Achievement for general medical conditions (depression, diabetes mellitus, hypertension, ischaemic heart disease, pain and cerebrovascular disease) improved from 75% (73–77) in 2004–05 to 80% (79–82) in 2010–11. Achievement ranged from 89% for cerebrovascular disease to 34% for osteoarthritis. Overall achievement was lower for participants who were men, wealthier, infrequent alcohol drinkers, not obese and living alone. Conclusion: substantial system-level shortfalls in quality of care for geriatric conditions persisted over 6 years, with relatively small and inconsistent variations in quality by participants' characteristics. The relative lack of variation by participants' characteristics suggests that quality improvement interventions may be more effective when directed at healthcare delivery systems rather than individuals

Nonlinear vertical oscillations of a particle in a sheath of a rf discharge

A new simple method to measure the spatial distribution of the electric field in the plasma sheath is proposed. The method is based on the experimental investigation of vertical oscillations of a single particle in the sheath of a low-pressure radio-frequency discharge. It is shown that the oscillations become strongly nonlinear and secondary harmonics are generated as the amplitude increases. The theory of anharmonic oscillations provides a good qualitative description of the data and gives estimates for the first two anharmonic terms in an expansion of the sheath potential around the particle equilibrium.Comment: 11 pages, 4 figure