The sense of security of Ukrainians and Belarusians studying in Poland.

Introduction And Objective: Due to educational migration to Poland, students from Ukraine and Belarus may experience security to varying degrees. The aim of the study was to check the extent to which people from Ukraine and Belarus studying in Lublin feel safe, taking into account their own life and health. An attempt was also made to establish the relationship between the sense of security and selected features of the surveyed students.

Visible-light-induced ATRP under high-pressure: synthesis of ultra-high-molecular-weight polymers.

In this study, a high-pressure-assisted photoinduced atom transfer radical polymerization ( ≤ 250 MPa) enabled the synthesis of ultra-high-molecular-weight polymers (UHMWPs) of up to 9 350 000 and low/moderate dispersity (1.10 < < 1.46) in a co-solvent system (water/DMSO), without reaction mixture deoxygenation.

The unique role of pore wall nanostructurization in the intrachannel photo-ATRP for fine-tuning PMMA tacticity.

In this paper, efficient MMA photo -ATRP protocols conducted inside nanoreactors varying in nanostructured interfaces are reported for the first time. We showed that the microstructure of recovered polymers could be easily tuned just by implementing a given type of nanochannel ( = 10, 19-28, 35, 160 nm).

The Effect of Various Poly (-vinylpyrrolidone) (PVP) Polymers on the Crystallization of Flutamide.

In this study, several experimental techniques were applied to probe thermal properties, molecular dynamics, crystallization kinetics and intermolecular interactions in binary mixtures (BMs) composed of flutamide (FL) and various poly(-vinylpyrrolidone) (PVP) polymers, including a commercial product and, importantly, samples obtained from high-pressure syntheses, which differ in microstructure (defined by the tacticity of the macromolecule) from the commercial PVP. Differential Scanning Calorimetry (DSC) studies revealed a particularly large difference between the glass transition temperature () of FL+PVPsynth. mixtures with 10 and 30 wt% of the excipient.

Supramolecular structures of self-assembled oligomers under confinement.

We study the molecular origin of a prepeak (PP) observed at low values in the structure factors of three oligomers in a bulk (poly(mercaptopropyl)methylsiloxane, PMMS, poly(methylmercaptopropyl)--hexylmethacrylate, PMMS--HMA, and poly(methylphenyl)siloxane, PMPS) in order to understand the lowering of the PP intensity detected for oligomers confined in cylindrical pores with low diameter. For this purpose, we use a combination of X-ray diffraction measurements and coarse-grained bead-spring molecular dynamics simulations. Our molecular modelling demonstrated that the planarity of the pendant groups triggers the self-association of oligomers into nanoaggregates.

High pressure as a novel tool for the cationic ROP of γ-butyrolactone.

In this study, we report the acid-catalyzed and high pressure assisted ring-opening polymerization (ROP) of γ-butyrolactone (GBL). The use of a dually-catalyzed approach combining an external physical factor and internal catalyst (trifluoromethanesulfonic acid (TfOH) or -toluenesulfonic acid (PTSA)) enforced ROP of GBL, which is considered as hardly polymerizable monomer still remaining a challenge for the modern polymer chemistry. The experiments performed at various thermodynamic conditions ( = 278-323 K and = 700-1500 MPa) clearly showed that the high pressure supported polymerization process led to obtaining well-defined macromolecules of better parameters ( = 2200-9700 g mol; = 1.

Stereoregulation, molecular weight, and dispersity control of PMMA synthesized free-radical polymerization supported by the external high electric field.

We show the remarkable effect of using static (DC) and alternating (AC) electric fields to control the free-radical polymerization of methyl methacrylate (MMA). The magnitude and/or frequency of the applied electric field (up to 154 kV cm) were found to control the molecular weight, dispersity, and stereochemistry of the produced polymers.

Assessment of the Level of Organic Dust and Mould Spores in the Work Environment of Baker.

Aim: This study was conducted to determine the level of fungal contamination of the air in bakeries to assess health hazards for workers.

Materials And Methods: Six bakeries producing traditionally baked goods were selected for the study. After a background survey, samples of exhaled air were collected to test for fungal aerosols.

Correlation between Locally Ordered (Hydrogen-Bonded) Nanodomains and Puzzling Dynamics of Polymethysiloxane Derivative.

We examined the behavior of poly(mercaptopropyl)methylsiloxane (PMMS), characterized by a polymer chain backbone of alternate silicon and oxygen atoms substituted by a polar pendant group able to form hydrogen bonds (-SH moiety), by means of infrared (FTIR) and dielectric (BDS) spectroscopy, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and rheology. We observed that the examined PMMS forms relatively efficient hydrogen bonds leading to the association of chains in the form of ordered lamellar-like hydrogen-bonded nanodomains. Moreover, the recorded mechanical and dielectric spectra revealed the presence of two relaxation processes.

Impact of Imidazolium-Based Ionic Liquids on the Curing Kinetics and Physicochemical Properties of Nascent Epoxy Resins.

We investigated the influence of anion type (salicylate, [(MOB)MIm][Sal], vs chloride, [(MOB)MIm][Cl]) of imidazolium-based ionic liquid (IL) and its content on the curing kinetics of bisphenol A diglicydyl ether (DGEBA of molecular weight = 340 g/mol). Further physicochemical properties (i.e.

Pressure-assisted solvent- and catalyst-free production of well-defined poly(1-vinyl-2-pyrrolidone) for biomedical applications.

In this work, we developed a fast, highly efficient, and environmentally friendly catalytic system for classical free-radical polymerization (FRP) utilizing a high-pressure (HP) approach. The application of HP for thermally-induced, bulk FRP of 1-vinyl-2-pyrrolidone (VP) allowed to eliminate the current limitation of ambient-pressure polymerization of 'l' monomer (LAM), characterized by the lack of temporal control yielding polymers of unacceptably large disperisites and poor result reproducibility. By a simple manipulation of thermodynamic conditions ( = 125-500 MPa, = 323-333 K) and reaction composition (two-component system: monomer and low content of thermoinitiator) well-defined poly(1-vinyl-2-pyrrolidone)s (PVP) in a wide range of molecular weights and low/moderate dispersities ( = 16.

The application of spatially restricted geometries as a unique route to produce well-defined poly(vinyl pyrrolidones) via free radical polymerisation.

We report, for the first time, the metal-free green synthesis of linear poly(vinyl pyrrolidone) (PVP) homopolymers of molecular weight higher than 100 kg mol-1 and narrow dispersities via thermal and photo-induced free radical polymerisation carried out within alumina nanoporous membranes acting as "nanoreactors".

Efficient metal-free strategies for polymerization of a sterically hindered ionic monomer through the application of hard confinement and high pressure.

In this paper, we have studied the effect of both hard confinement (nanoporous membranes treated as nanoreactors) and high pressure (compression of system) on the progress of free-radical (FRP) and reversible addition-fragmentation chain transfer (RAFT) polymerizations of selected hardly polymerizable, sterically hindered imidazolium-based ionic monomer 1-octyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide ([OVIM][NTf]). These two innovative approaches, affecting (in a different way) the free volume of the polymerizing system, allows the reduction of the number of toxic substrates/catalysts, satisfying the requirement of green chemistry. It was found that at both conditions (high compression and confinement) the polymerizability of monomer, as well as the control over the reaction and the properties of the produced polyelectrolytes, have increased significantly.

Severity of work in opinions of rural women living in the Bieszczady region of south-eastern Poland.

Objective: The objective of the study was recognition of the opinions of rural women living in the Bieszczady region of south-eastern Poland, concerning their perception of the degree of severity of work. The study was conducted among the inhabitants of the Cisna commune.

Material And Methods: The basic research instrument was a questionnaire form containing 15 items.

Evaluating bioaerosol exposure among bus drivers in the public transport sector.

Occupational hazards and consequent health problems suffered by drivers in the public transport sector require preventive measures. The aim of this study was to assess the exposure of drivers to microbiological air contamination (airborne bacteria and fungi) in buses. The air in public transport vehicles was examined in autumn, winter and spring.

Polymerization of Monomeric Ionic Liquid Confined within Uniaxial Alumina Pores as a New Way of Obtaining Materials with Enhanced Conductivity.

Broadband dielectric spectroscopy (BDS) and differential scanning calorimetry (DSC) have been employed to probe dynamics and charge transport of 1-butyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide ([bvim][NTf]) confined in native uniaxial AAO pores as well as to study kinetics of radical polymerization of the examined compound as a function of the degree of confinement. Subsequently, the electronic conductivity of the produced polymers was investigated. As observed, polymerization carried out at T = 363 K proceeds faster under confinement with some saturation effect observed for the sample in pores of smaller diameter.

Evaluation of working conditions of workers engaged in tending horses.

Introduction: A growing interest in the horse business has resulted in the increased engagement of many people in this area, and the health problems occurring among workers create the need to search for prophylactic measures.

Objective: The objective of the study was evaluation of the level of exposure to air pollution in a stable, and estimation of the degree of work load among workers engaged in tending horses.

Material And Methods: The study was conducted twice, during the winter season, in a stable maintaining race horses, and in a social room.

Evaluation of work conditions in a pasta manufacturing plant with particular consideration of dustiness.

Objective: The objective of the study was evaluation of work conditions in a pasta manufacturing plant, including: physical and psychological load and factors of material work environment. The main aim was determination of the level of employees' exposure to our dust.

Methods: Studies of work conditions were conducted in a our processing plant in the Lublin region at the workplace of an automatic production line - operator of the noodle production line, employees packaging pasta, and the manual line - employees responsible for the kneading of dough, cutter operators, and employees engaged in packaging.

Unraveling quantum Hall breakdown in bilayer graphene with scanning gate microscopy.

Investigating the structure of quantized plateaus in the Hall conductance of graphene is a powerful way of probing its crystalline and electronic structure and will also help to establish whether graphene can be used as a robust standard of resistance for quantum metrology. We use low-temperature scanning gate microscopy to image the interplateau breakdown of the quantum Hall effect in an exfoliated bilayer graphene flake. Scanning gate images captured during breakdown exhibit intricate patterns where the conductance is strongly affected by the presence of the scanning probe tip.

Enhanced donor binding energy close to a semiconductor surface.

We measured the ionization threshold voltage of individual impurities close to a semiconductor-vacuum interface, where we use the STM tip to ionize individual donors. We observe a reversed order of ionization with depth below the surface, which proves that the binding energy is enhanced towards the surface. This is in contrast to the predicted reduction for a Coulombic impurity in the effective mass approach.

Magnetic field induced confinement-deconfinement transition in graphene quantum dots.

Massless Dirac particles cannot be confined by an electrostatic potential. This is a problem for making graphene quantum dots but confinement can be achieved with a magnetic field and here general conditions for confined and deconfined states are derived. There is a class of potentials for which the character of the state can be controlled at will.

Inverted electron-hole alignment in InAs-GaAs self-assembled quantum dots.

New information on the electron-hole wave functions in InAs-GaAs self-assembled quantum dots is deduced from Stark effect spectroscopy. Most unexpectedly it is shown that the hole is localized towards the top of the dot, above the electron, an alignment that is inverted relative to the predictions of all recent calculations. We are able to obtain new information on the structure and composition of buried quantum dots from modeling of the data.