Jan Długosz University

About: Jan Długosz University is a education organization based out in Częstochowa, Poland. It is known for research contribution in the topics: Crystal structure & Luminescence. The organization has 749 authors who have published 2311 publications receiving 19395 citations. The organization is also known as: Higher Teacher Education School.

Low temperature dielectric dispersion and electrical conductivity studies on Fe2O3 mixed lithium yttrium silicate glasses

Abstract: article i nfo Article history: Received 5 June 2012 Received in revised form 1 September 2012 Available online xxxx Lithium yttrium silicate glasses mixed with different concentrations of Fe2O3 of the composition (40 −x) Li2O-10Y2O3-50SiO2 :xF e2O3, with x=0.3, 0.5, 0.8, 1.0, 1.2 and 1.5 (all in mol%) were synthesized. Electrical and dielectric properties including dielectric constant, e'(ω), loss, tan δ, ac conductivity, σac, impedance spec- tra as well as electric moduli, M(ω), over a wide continuous frequency range of 40 Hz to 10 6 Hz and in the low temperature range 100 to 360 K were measured as a function of the concentration of Fe2O3. The dc con- ductivity is also evaluated in the temperature range 100 … 360 K. The temperature and frequency disper- sions of dielectric constant as well as dielectric loss have been analyzed using space charge polarization model. The ac and dc conductivities have exhibited increasing trend with increasing Fe2O3 content beyond 0.5 mol%, whereas the activation energy for the conductivity demonstrated decreasing tendency in this dop- ant concentration range. Both quantum mechanical tunneling (QMT) and correlated barrier hopping models (CBH) were used for clarification of ac conductivity origin and the corresponding analysis has indicated that CBH model is more appropriate for this glass system. For the better understanding of relaxation dynamics of the electrical properties we have drawn the scaling plots for ac conductivity and also electric moduli. The plots indicated that the relaxation dynamics is independent on temperature but depends on concentration of Fe2O3. The dc conductivity is analyzed using small polaron hoping model. The increase of conductivity with the concentration of Fe2O3 beyond 0.5 mol% is explained in terms of variations in the redox ratio of iron ions in the glass network. The results were further analyzed quantitatively with the support of experi- mental data from IR, optical absorption and ESR spectral studies. The overall analysis has indicated that Li2O-Y2O3-SiO2 glasses containing more than 0.5 mol% of Fe2O3 are more suitable for achieving good electri- cal conductivity in these glasses.

A New Translation from ECTL* to SAT

Abstract: In this paper we present a new translation from ECTL* to SAT and show that the proposed translation substantially increases the efficiency of verifying temporal properties using the Bounded Model Checking method We have implemented our new translation and made experimental results, which demonstrate the efficiency of the method

Shape‐memory bioresorbable terpolymer composite with antirestenotic drug

Abstract: Shape-memory polymers (SMPs) that combine shape-memory, biodegradability, and controlled drug release properties are very promising for medical and pharmaceutical application. Moreover, incorporation of antirestenotic drug into SMP biodegrad- able stent seems to be an interesting solution because of possibility to combine the mechanical support that provides stent and also drug elution. The aim of our study was to analyze the effect of incorporation of sirolimus into poly(L-lactide-co-glycolide-co-trimethy- lene carbonate) on physicochemical and mechanical properties, degradation, and shape-memory effect of the terpolymer. For this purpose, sirolimus was incorporated into the terpolymer by injection molding method. It has been demonstrated that drug-free ter- polymer after injection molding characterized insignificant changes in terpolymer composition. Degradation of materials during proc- essing was not observed. Incorporation of drug molecules did not change shape-memory properties of terpolymer. 1 H- and 13 C-NMR spectra of poly(lactide-co-glycolide-co-trimethylene carbonate) confirmed that changes during degradation were similar for terpolymer and terpolymer with sirolimus. Sustained and regular release of sirolimus was observed. The developed material presents potential for biomedical and pharmaceutical applications. V C 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41902.

SAT-Based Reachability Checking for Timed Automata with Discrete Data

Abstract: Reachability analysis for timed automata using SAT-based methods was considered in many papers, occurring to be a very efficient model checking technique. In this paper we show how to apply this method of verification to timed automata with discrete data, i.e., to standard timed automata augmented with integer variables. The theoretical description is supported by some preliminary experimental results.

Aging effect on the instrumented Timed-Up-and-Go test variables in nursing home women aged 80–93 years

Abstract: Although the total “Timed-Up-and Go” test (TUG) performance time can characterize an age-related decline of general mobility, this result alone doesn’t give any detailed information about the test subtasks. The primary objective of the study was to identify in nursing home women a variable extracted from instrumented TUG (iTUG) that is the best predictor of age. The secondary objective was to assess whether this variable is associated with the results of the isometric knee extension peak torque (IKEPT); lower limb strength measured by the 30-s chair stand test (30sCST), and walking capacity measured by the 6-min walk test (6MWT). Twenty-six women (mean ± SD: age—85.8 ± 3.6 years; body weight—59.4 ± 12.3 kg; body height—151.0 ± 7.3 cm; BMI—26.0 ± 4.9 kg/m2) performed iTUG (while wearing a body-fixed inertial sensor) and functional tests. Total iTUG performance time significantly correlated with age (r = 0.484; p 0.05). Additionally, the subjects’ age correlated with 30sCST (r = −0.422; p 0.05). The obtained results suggest that in the oldest old group of nursing home women an age-related decline in TUG performance is mainly associated with a reduction of “explosive” strength of lower limb muscles.