89 research outputs found
Heat transport in an open transverse-field Ising chain
The heat conduction in an open transverse-field Ising chain is studied by
using quantization in the Fock space of operators in the weak coupling regimes,
i.e. the coupling is much smaller than the transverse field. The
non-equilibrium steady state is obtained for large size systems coupled to
Markovian baths at its ends. The ballistic transport is observed in the uniform
chain and normal diffusion in the random-exchange chain. {In addition, the
ballistic-diffusive transition is found at the intermediate disorder regime.}
The thermal conductivity is also calculated in the low and high
temperature regimes. It is shown that decays as at
high temperatures.Comment: 6 pages, 7 figure
Markovian Master Equations: A Critical Study
We derive Markovian master equations of single and interacting harmonic
systems in different scenarios, including strong internal coupling. By
comparing the dynamics resulting from the corresponding Markovian master
equations with exact numerical simulations of the evolution of the global
system, we precisely delimit their validity regimes and assess the robustness
of the assumptions usually made in the process of deriving the reduced
dynamics. The proposed method is sufficiently general to suggest that the
conclusions made here are widely applicable to a large class of settings
involving interacting chains subject to a weak interaction with an environment.Comment: 40 pages, 14 figures, final versio
Monetary Policy and Polish Labour Market in the years 1999 - 2008
This article sets out to analyse how the monetary policy pursued by the National Bank of Poland (NBP) determined the labour market situation in the country in the decade 1999-2008. The article consists of introduction as well as five sections. Section one discusses NBP's strategy of monetary policy in the defined period against monetary strategies implemented in other countries. Section two uses the growth rates of money supply and of real GDP to verify whether the primary purpose of monetary policy, i.e. the inflationary target, was achieved. Section three generally characterises the country's labour market using the levels and dynamics of employment and of unemployment. Section four discusses major instruments of NBP's monetary policy, mainly analysing changes in the central bank's interest rates and their effect on the economic situation and on the labour market. The article concludes with a summation providing synthetic conclusions.Celem artykułu jest analiza wpływu polityki monetarnej Narodowego Banku Polskiego (NBP) na sytuację na rynku pracy w Polsce w ciągu dekady obejmującej lata 1999-2008. Opracowanie składa się z wprowadzenia oraz pięciu części. W pierwszej z nich omówiona została strategia polityki monetarnej NBP w badanym okresie wraz z porównaniem ze strategią przyjmowaną w innych krajach. W części drugiej sprawdzono, czy realizowany był podstawowy cel polityki monetarnej, czyli cel inflacyjny, w kontekście kształtowania się stóp wzrostu podaży pieniądza oraz realnego PKB. W punkcie kolejnym ukazana została ogólna charakterystyka rynku pracy na podstawie kształtowania się poziomu i dynamiki zatrudnienia oraz bezrobocia. W części czwartej omówiono podstawowe instrumenty polityki pieniężnej NBP. Uwaga skoncentrowana została głównie na analizie zmian stóp procentowych banku centralnego oraz ich wpływu na sytuację gospodarczą i rynek pracy. Całość zamknięta została podsumowaniem, w którym zawarto syntetyczne wnioski końcowe
DNA damage and repair in endometrial cancer in correlation with the hOGG1 and RAD51 genes polymorphism
The cellular reaction to the DNA-damaging agents may modulate individual’s cancer susceptibility. This reaction is mainly determined by the efficacy of DNA repair, which in turn, may be influenced by the variability of DNA repair genes, expressed by their polymorphism. The hOGG1 gene encodes a glycosylase of base excision repair and RAD51 specifies a key protein in homologues recombination repair. Both proteins can be involved in the repair of DNA lesions, which are known to contribute to endometrial cancer. In the present work we determined the extent of basal DNA damage and the efficacy of removal of DNA damage induced by hydrogen peroxide and N-methyl-N′-nitro N-nitrosoguanidyne (MNNG) in peripheral blood lymphocytes of 30 endometrial cancer patients and 30 individuals without cancer. The results from DNA damage and repair study were correlated with the genotypes of two common polymorphisms of the hOGG1 and RAD51 genes: a G>C transversion at 1245 position of the hOGG1 gene producing a Ser → Cys substitution at the codon 326 (the Ser326Cys polymorphism) and a G>C substitution at 135 position of the RAD51 gene (the 135G>C polymorphism). DNA damage and repair were evaluated by alkaline single cell gel electrophoresis and genotypes were determined by restriction fragment length polymorphism PCR. We observed a strong association between endometrial cancer and the C/C genotype of the 135G>C polymorphism of the RAD51 gene. Moreover, there was a strong correlation between that genotype and endometrial cancer occurrence in subjects with a high level of basal DNA damage. We did not observe any correlation between the Ser326Cys polymorphism of the hOGG1 gene and endometrial cancer. Our result suggest that the 135G>C polymorphism of the RAD51 gene may be linked to endometrial cancer and can be considered as an additional marker of this disease
Radiation chemistry of solid-state carbohydrates using EMR
We review our research of the past decade towards identification of radiation-induced radicals in solid state sugars and sugar phosphates. Detailed models of the radical structures are obtained by combining EPR and ENDOR experiments with DFT calculations of g and proton HF tensors, with agreement in their anisotropy serving as most important criterion. Symmetry-related and Schonland ambiguities, which may hamper such identification, are reviewed. Thermally induced transformations of initial radiation damage into more stable radicals can also be monitored in the EPR (and ENDOR) experiments and in principle provide information on stable radical formation mechanisms. Thermal annealing experi-ments reveal, however, that radical recombination and/or diamagnetic radiation damage is also quite important. Analysis strategies are illustrated with research on sucrose. Results on dipotassium glucose-1-phosphate and trehalose dihydrate, fructose and sorbose are also briefly discussed. Our study demonstrates that radiation damage is strongly regio-selective and that certain general principles govern the stable radical formation
Country-Specific Determinants of Textile Industry Development in Poland: Comparative Analysis of the Years 2007 and 2017
The textile industry is a significant sector of the Polish economy and is characterized by a strong potential. Its development can be ensured by activities in the areas of finance, technical infrastructure, environmental protection, and demographic conditions. The development of the textile sector is significantly affected by factors such as quality of commune and poviat roads, length of the sewerage network, expenditure on environmental protection, expenditures on innovative activity and on research and development, and costs related to employment and population of working age. The aim of this paper is to determine the attractiveness level of individual Polish regions for the development of the textile sector in relation to five microclimates, which somehow define the most important determinants of the development of this sector of the economy. In order to achieve this aim, the following research methods are used: presentation of statistical data and statistical methods of research. The authors test the research hypothesis that the growth potential of textile industry enterprises is the largest in the most prosperous provinces
Characterization of the novel calcium phosphate/sulfate based bone cements
Calcium phosphate cements (CPCs) are a family of self-setting, bone repair materials. CPCs possess excellent biocompatibility, surgical handiness and adequate mechanical properties but reveal slow resorption in vivo. Currently, very interesting group of CPCs are biomaterials composed of a-tricalcium phosphate (a-TCP, a-Ca3(PO4)2) and calcium sulfate. Calcium sulfate hemihydrate (CSH, CaSO40.5 H2O) posses a long clinical history in different fields of medicine and is widely recognized as a safe, fast setting and resorbable implant material. The main goal of this study was to investigate how different factors influence the phase composition and physico-chemical properties of the new, cement-type material on the basis of a-TCP, CSH and anhydrous dicalcium phosphate (DCP, CaHPO4). In presented work two different powder phase compositions and three liquid phases were used to produce new bone substitutes. XRD results showed that obtained materials, after setting and hardening, consisted of α-TCP, DCP, DCPD (CaHPO42H2O), HA and bassanite phases. Initial (I) and final (F) setting times of the cement pastes were determined with Gillmore needles and differed in the range of 4-14 min (I) and 10-30 min (F). Increase in the amount of CSH in the powder component resulted in shortening of setting time. Microstructure of cements was evaluated on the fractured samples by scanning electron microscopy (SEM) and the porosity via mercury porosimetry. Open porosity of the final materials was similar for all investigated compositions. Compressive strength depended on the composition and increased steadily over a period of maturation. The results obtained suggest that calcium phosphate/sulfate bone cement has the potential to be applied for bone augmentation
Biodegradable cement type bone implant materials based on calcium phosphates and calcium sulphate
Calcium phosphates (CaPs) are widely used in hard tissue replacement because of their excellent biocompatibility. Calcium phosphate cements (CPCs) are an interesting alternative for sintered calcium phosphate ceramics due to their mouldability and self-setting properties which allow them to conform to even the most complex bone defects. However, one of the major limitations of CPCs is their relatively low resorption rate, not optimal for bone regeneration. The aim of our studies was to combine a stable hydroxyapatite with more soluble α-tricalcium phosphate (α-TCP) or calcium sulphate (CS) (resorbability: CS>>α-TCP>HA) to develop biomaterial with gradual degradation. Promising materials for use in minimally invasive surgery for bone defects repair were obtained. It was found that the degradation rate of hydroxyapatite based bone substitutes can be controlled by the addition of an appropriate kind and amount of more soluble constituent. The impact of the setting component (α-TCP or CS) on the physicochemical properties of the final products was confirmed. Furthermore the influence of organic additives (chitosan, methylcellulose, alginate) on the final materials characteristic was proven. Solutions of organic additives, applied as the liquid phases, significantly improved the workability of cement pastes. It has been demonstrated that implant materials based on calcium sulphate and α-TCP differed in their setting times, mechanical strength, dissolution rate and morphologies of apatite layers on their surfaces after soaking in simulated body fluid. The reason of observed differences is a higher susceptibility of calcium sulphate to both disintegration and degradation
Impact of Shale Gas Exploitation on the Drinking Water Reservoirs. Case of Lublin Region
The energy supply which would not contribute to climate change is biggest challenge facing modern civilization Bottom line is that the supply of energy is essential for the development of human civilization. In the very near future, shale gas may constitute an important source of energy. Poland has significant shale gas deposits. Polish Geological Institute estimated its amount at around 346–768 billion cubic meters. However, exploration works meets with large protests of residents, who are afraid of the contamination of drinking water. Considering the number of protests, it seems reasonable to undertake research on the development of water quality monitoring system in the shale gas exploitation site. The basic rule of this monitoring is to determine what chemicals are introduced into wells. The next step is to select water intakes located nearby. This paper presents and evaluates the quality of water taking into account inorganic compounds added to drilling fluids and fracturing fluids. The study contains the results on the content of trace metal ions, chlorides, nitrates, phosphates and sulphates. The study does not assess organic compounds content which can be added to the fluids in the process of hydraulic fracturing
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