Modification of thin films induced by slow heavy ions analysed with PIXE and SRIM

In the present work the particle induced X-rays (PIXE) emitted during interaction of inert and active slow heavy (HI) ions with specially prepared thin films were measured. Kinematics of the interaction was simulated numerically with SRIM in grazing incident-exit angle geometry and in time sequence in order to determine dynamics of formation of the subsurface region damaged through implantation, sputtering and interface mixing. It was shown that the structure and composition of films and surfaces are not stable against HI irradiation due to preferential sputtering and implantation of ions and recoils and that dynamics of such a modification can be in-situ monitored with PIXE and analyzed with SRIM

The Study of Nano-optics In Hybrid Systems

In this thesis, we study the quantum light-matter interaction in polaritonic heterostructures. These systems are made by combining various nanocomponents, such as quantum dots, graphene films, metallic nanoparticles and metamaterials. These heterostructures are used to develop new optoelectronic devices due to the interaction between nanocomposites. Photoluminescence quenching and absorption spectrum are determined and an explanatory theory is developed for these polaritonic heterostructures. Photoluminescence quenching is evaluated for a graphene, metallic nanoparticle and quantum dot system. It is shown that average distance between nanocomposites or concentration of nanocomposites affect the output these system produced. Photoluminescence quenching was also evaluated for a metamaterial hybrid system. Lastly, the absorption spectrum of quantum dots was calculated in a quantum dot and metamaterial system. The metamaterial contained two surface plasmon modes which if in resonance with excitons of the quantum dot shown an enhancement in the absorption spectrum of the quantum dot

Clustering with minimum spanning trees: How good can it be?

Minimum spanning trees (MSTs) provide a convenient representation of datasets in numerous pattern recognition activities. Moreover, they are relatively fast to compute. In this paper, we quantify the extent to which they can be meaningful in data clustering tasks. By identifying the upper bounds for the agreement between the best (oracle) algorithm and the expert labels from a large battery of benchmark data, we discover that MST methods can overall be very competitive. Next, instead of proposing yet another algorithm that performs well on a limited set of examples, we review, study, extend, and generalise existing, the state-of-the-art MST-based partitioning schemes, which leads to a few new and interesting approaches. It turns out that the Genie method and the information-theoretic approaches often outperform the non-MST algorithms such as k-means, Gaussian mixtures, spectral clustering, BIRCH, and classical hierarchical agglomerative procedures

Syntactic Complexity of Suffix-Free Languages

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.ic.2017.08.014 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/We solve an open problem concerning syntactic complexity: We prove that the cardinality of the syntactic semigroup of a suffix-free language with n left quotients (that is, with state complexity n) is at most (n−1)n−2+n−2 for n⩾6. Since this bound is known to be reachable, this settles the problem. We also reduce the alphabet of the witness languages reaching this bound to five letters instead of n+2, and show that it cannot be any smaller. Finally, we prove that the transition semigroup of a minimal deterministic automaton accepting a witness language is unique for each n.Natural Sciences and Engineering Research Council of Canada (NSERC) grant No. OGP000087National Science Centre, Poland project number 2014/15/B/ST6/0061

Complexity of Suffix-Free Regular Languages

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.jcss.2017.05.011 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/We study various complexity properties of suffix-free regular languages. A sequence (Lk,Lk+1,…) of regular languages in some class, where n is the quotient complexity of Ln, is most complex if its languages Ln meet the complexity upper bounds for all basic measures. It is known that there exist such most complex sequences in several classes of regular languages. In contrast to this, we prove that there does not exist a most complex sequence in the class of suffix-free regular languages. However, we do exhibit two such sequences that together meet upper bounds for all basic measures.Natural Sciences and Engineering Research Council of Canada (NSERC) grant No. OGP000087National Science Centre, Poland project number 2014/15/B/ST6/0061

Determinants of self-employment among Polish and Romanian immigrants in Germany

This empirical study investigates the determinants of self-employment propensity of Polish and Romanian immigrants in Germany. The German economy is an important object of analysis, as it is the most important destination for international migrants in the European Union. In the paper, we use the recently collected M sample of the German Socio-Economic Panel to examine which personal, country of birth-specific socio-economic and cultural factors influence the self-employment propensity of immigrants. The results of binominal logit regression show that the Central European migrants exhibit different self-employment propensity than migrants from former Yugoslavia, Russian and Kazakhstan, Turkey and Italy, with the self-employment aversion especially strong among Romanians. These differences remain substantial even after controlling for social and human capital endowment of the individuals. This study offers important policy recommendations, showing the potential obstacles in encouraging entrepreneurial activity of immigrants. This topic is becoming increasingly important with the current migration crisis in the EU, caused by intensive inflow of asylum-seeking foreigners in 2015

Lead dependent tricuspid dysfunction: Analysis of the mechanism and management in patients referred for transvenous lead extraction

Background: Lead-dependent tricuspid dysfunction (LDTD) is one of important complicationsin patients with cardiac implantable electronic devices. However, this phenomenon isprobably underestimated because of an improper interpretation of its clinical symptoms. Theaim of this study was to identify LDTD mechanisms and management in patients referred fortransvenous lead extraction (TLE) due to lead-dependent complications.Methods: Data of 940 patients undergoing TLE in a single center from 2009 to 2011 wereassessed and 24 patients with LDTD were identifi ed. The general indications for TLE, pacingsystem types and lead dwell time in both study groups were comparatively analyzed. Theradiological and clinical effi cacy of TLE procedure was also assessed in both groups with precisionestimation of clinical status patients with LDTD (before and after TLE). Additionally,mechanisms, concomitant lead-dependent complications and degree (severity) of LDTD beforeand after the procedure were evaluated. Telephone follow-up of LDTD patients was performedat the mean time 1.5 years after TLE/replacement procedure.Results: The main indications for TLE in both groups were similar (apart from isolatedLDTD in 45.83% patients from group I). Patients with LDTD had more complex pacing systemswith more leads (2.04 in the LDTD group vs. 1.69 in the control group; p = 0.04). Therewere more unnecessary loops of lead in LDTD patients than in the control group (41.7% vs.5.24%; p = 0.001). There were no signifi cant differences in average time from implantationto extraction and the number of preceding procedures. Signifi cant tricuspid regurgitation(TR-grade III–IV) was found in 96% of LDTD patients, whereas stenosis with regurgitationin 4%. The 10% frequency of severe TR (not lead dependent) in the control group patients wasobserved. The main mechanism of LDTD was abnormal leafl et coaptation caused by: loop ofthe lead (42%), septal leafl et pulled toward the interventricular septum (37%) or too intensivelead impingement of the leafl ets (21%). LDTD patients were treated with TLE and reimplantationof the lead to the right ventricle (87.5%) or to the cardiac vein (4.2%), or surgery procedure with epicardial lead placement following ineffective TLE (8.3%). The radiological and clinicaleffi cacy of TLE procedure was very high and comparable between the groups I and II (91.7%vs. 94.2%; p = 0.6 and 100% vs. 98.4%; p = 0.46, respectively). Repeated echocardiographyshowed reduced severity of tricuspid valve dysfunction in 62.5% of LDTD patients. The follow--up interview confi rmed clinical improvement in 75% of patients (further improvement aftercardiosurgery in 2 patients was observed).Conclusions: LDTD is a diagnostic and therapeutic challenge. The main reason for LDTDwas abnormal leafl et coaptation caused by lead loop presence, or propping, or impingementthe leafl ets by the lead. Probably, TLE with lead reimplantation is a safe and effective optionin LDTD management. An alternative option is TLE with omitted tricuspid valve reimplantation.Cardiac surgery with epicardial lead placement should be reserved for patients withineffective previous procedures

Endovascular treatment of descending aorta gunshot injury

Obrażenia dużych naczyń klatki piersiowej stanowią poważny problem nie tylko pod względem czysto terapeutycznym, ale również ze względu na ich lokalizację: pod względem dostępu chirurgicznego do leczenia operacyjnego. Większość chorych z ranami postrzałowymi aorty piersiowej i naczyń ramienno-głowowych nie dociera do sali operacyjnej, natomiast leczenie tych, którzy dotrą, jest dużym wyzwaniem dla torakochirurgów i chirurgów naczyniowych. W takich wypadkach leczenie operacyjne musi być zindywidualizowane. Wiele zależy od doświadczenia osoby przeprowadzającej zabieg, w tym często jej znajomości wybranych technik kardiochirurgicznych. W doniesieniu przedstawiono przypadek pacjentki postrzelonej z broni śrutowej w górną część klatki piersiowej, z uszkodzeniami skóry, mięśni oraz tkanek i narządów położonych głębiej, w tym serca i aorty zstępującej. Omawiając powyższy przypadek, poruszono niektóre najistotniejsze problemy związane z leczeniem tych chorych.Vascular injuries of the thoracic inlet and mediastinum present formidable difficulties in terms of exposure and management. The majority of patients with gunshot wounds to the thoracic aorta and brachiocephalic vessels do not reach the operating room alive, but those who do present unique problems for thoracic and vascular surgeons. In such cases, operative repair must be individualized and often must depend on experience with other elective cardiovascular procedures. This report details the management of a patient suffering wound to the superior thoracic region from a low-velocity hunting shotgun, involving superficial (skin and muscles) and deep tissues (heart and descending aorta). Some of the difficulties inherent in managing such an injury are discussed

Variations in the anatomy of the branches of an aortic arch - two cases

Zmienność anatomiczna pni odchodzących od łuku aorty jest znaczna. W codziennej praktyce w większości przypadków anatomiczne odmiany naczyń odchodzących od łuku aorty pozostają niewykryte. Ponadto najczęściej nie powodują one objawów klinicznych i dopiero patologie dotyczące pnia ramienno-głowowego i/lub jego odgałęzienia oraz tętnicy szyjnej wspólnej lewej i podobojczykowej pozwalają na ich rozpoznanie. W niniejszej pracy przedstawiono dwa przypadki chorych, u których rozpoznano odejście lewej tętnicy szyjnej wspólnej od pnia ramienno-głowowego.Variations in the anatomy of the branches of the aortic arch (AA) are well known. But in ordinary surgical practice, being asymptomatic, most of these anatomical variations remain unrecognized. As vascular pathologies proceed affecting the innominate artery (IA) and/or its branches, including the left common carotid artery (CCA) and subclavian artery (SA) - they are noticed and detected. In our paper, two cases of the origin of left CCA from IA are presented