A Helly theorem for convexity in graphs

AbstractIt is shown that for chordless path convexity in any graph, the Helly number equals the size of a maximum clique

POMIARY PRZEPŁYWÓW WIELOFAZOWYCH Z WYKORZYSTANIEM TOMOGRAFU MULTIMODALNEGO DECART

The multi-phase flow measurements are very important tasks in many areas of industrial processes applications. One of them is undersea exploration of oil in the petroleum industry. The submitted paper presents application of DECART tomograph designed and built in Lodz University of Technology - together with combined measurements of signals acquired from gamma ray measurement system. Use of all measuring modalities allowed for performing measurements of a flow composed of sea water, oil and gas. The paper presents theoretical principles applied to design multimodality tomograph and results of experiments performed in the University of Bergen. Measurement confirmed that multi-modality approach allows giving fast and reliable on-line results of measurements of composition of multi-phase flow. Applied algorithms allowed to speed up on-line measurements and presenting results in a form required in industrial applications. The derived conclusions can be used as guidelines for preparation of industrial applicable construction of tomograph.Pomiary przepływów wielofazowych są szeroko wykorzystywane w wielu procesach przemysłowych. Jednym z nich jest przemysł petrochemiczny, w szczególności dziedzina eksploatacji podwodnych złóż ropy naftowej. W artykule zostało przedstawione zastosowanie tomografu DECART - zaprojektowanego i zbudowanego w Instytucie Informatyki Stosowanej Politechniki Łódzkiej. Pomiary z tomografu zostały powiązane z sygnałami uzyskanymi z systemu pomiaru promieniowania gamma. Wykorzystanie danych uzyskanych z różnych rodzajów czujników umożliwiło pomiar przepływu mieszaniny składającej się z wody morskiej, ropy naftowej i gazu. W pracy przedstawiono podstawy teoretyczne, które stanowiły punkt wyjścia do wykorzystania tomografu multimodalnego jak i wyniki eksperymentów przeprowadzonych na Uniwersytecie w Bergen. Pomiary potwierdziły, że podejście multimodalne umożliwia szybki i niezawodny pomiar udziału faz w przepływie wielofazowym. Zastosowane algorytmy pozwalają na przyspieszenie pomiarów on-line i przedstawienie wyników w formie wymaganej w zastosowaniach przemysłowych. Wnioski z badań mogą być wykorzystane jako wskazówki dla konstrukcji tomografu do praktycznych zastosowań przemysłowych

Wpływ transportu drogowego na rozwój klastrów w świetle procesów globalizacyjnych

Permanent changes around us, resulting from globalization processes, are conductive to rapid development of various branches of economy including the branch of transportation. This development demands creating new principles of competitiveness from enterprises and what is more requires contemporary rules of performing on the market. The new dimension of competi- tiveness means the competitiveness based on a cooperation which functions on the market as a cluster. Cluster structures profitably influence economy development of the whole region or even of the country but those structures also lead to the increase of effectiveness of the whole organiza- tion. Therefore, contemporary transportation enterprises which functions under the consolidated EU market conditions must seek for such a form of cooperation which allows to compete inside the cluster, and also make a use of its rational advantages. This cooperation mainly is conductive to an increase of competitiveness inside the transportation system and its effectiveness as well

Pulmonary langerhans cell histiocytosis

Pulmonary Langerhans Cell Histiocytosis (PLCH) is a relatively uncommon lung disease that generally, but not invariably, occurs in cigarette smokers. The pathologic hallmark of PLCH is the accumulation of Langerhans and other inflammatory cells in small airways, resulting in the formation of nodular inflammatory lesions. While the overwhelming majority of patients are smokers, mechanisms by which smoking induces this disease are not known, but likely involve a combination of events resulting in enhanced recruitment and activation of Langerhans cells in small airways. Bronchiolar inflammation may be accompanied by variable lung interstitial and vascular involvement. While cellular inflammation is prominent in early disease, more advanced stages are characterized by cystic lung destruction, cicatricial scarring of airways, and pulmonary vascular remodeling. Pulmonary function is frequently abnormal at presentation. Imaging of the chest with high resolution chest CT scanning may show characteristic nodular and cystic abnormalities. Lung biopsy is necessary for a definitive diagnosis, although may not be required in instances were imaging findings are highly characteristic. There is no general consensus regarding the role of immunosuppressive therapy in smokers with PLCH. All smokers must be counseled on the importance of smoking cessation, which may result in regression of disease and obviate the need for systemic immunosuppressive therapy. The prognosis for most patients is relatively good, particularly if longitudinal lung function testing shows stability. Complications like pneumothoraces and secondary pulmonary hypertension may shorten life expectancy. Patients with progressive disease may require lung transplantation

INTELIGENTNY SYSTEM DIAGNOSTYKI I STEROWANIA PRZEPŁYWAMI DWUFAZOWYMI NA PODSTAWIE POMIARÓW 3D ECT

In this paper the new intelligent system for two-phase flows diagnosis and control is presented. The authors developed a fuzzy inference system for two phase flows recognition based on the raw 3D ECT data statistical analysis and fuzzy classification which identify the flow structure in real-time mode. The non-invasive three-dimensional monitoring is possible to conduct even in non-transparent and non-accessible parts of the pipeline. Presented system is also equipped with the two phase gas-liquid flows installation control module based on fuzzy inference which includes the feedback information from the recognition module.  The intelligent control module working in a feed-back loop keep the sets of required flow regime. Presented in this paper fuzzy algorithms allow to recognize the two phase processes similar to the human expert and to control the process in the same, very intuitively way. Using of the artificial intelligence in the industrial applications allows to avoid any random errors as well as breakdowns and human mistakes suffer from lack of objectivity. An additional feature of the system is a universal multi-touched monitoring-control panel which is an alternative for commercial solution and gives the opportunity to build user own virtual model of the flow rig to efficiently monitor and control the process.W artykule zaprezentowany został inteligentny system diagnostyki i sterowania przepływami dwufazowymi gaz-ciecz. Autorzy opracowali rozmyty system wnioskowania oparty o statystyczną analizę i klasyfikację rozmytą surowych danych pomiarowych 3D ECT realizujący w czasie rzeczywistym identyfikację struktury przepływu oraz wyznaczanie objętościowego udziału faz. Nieinwazyjny trójwymiarowy monitoring przepływu możliwy jest w nieprzezroczystych i trudno dostępnych fragmentach rurociągów w czasie rzeczywistym. Prezentowany system wyposażony jest również w moduł sterowania instalacją w oparciu o wnioskowanie rozmyte, któremu na wejście podawane są informacje zwrotne od modułu rozpoznawania. Inteligentny regulator rozmyty pracujący w pętli sprzężenia zwrotnego utrzymuje żądane nastawy parametrów przepływu w oparciu o zadany reżim przepływu. Przedstawione w niniejszym opracowaniu algorytmy rozmyte umożliwiają identyfikację procesów dwu-fazowych w sposób analogiczny do tego, jak to robią specjaliści oraz jednocześnie pozwalają kontrolować proces w ten sam bardzo intuicyjny sposób. Zastosowanie sztucznej inteligencji w aplikacjach przemysłowych pozwala uniknąć przypadkowych ludzkich błędów podatnych na brak obiektywizmu, a także zapobiegać awarii. Cechą dodatkową systemu jest uniwersalny dotykowy panel monitorująco-sterujący stanowiący alternatywę dla drogich komercyjnych rozwiązań umożliwiający budowanie wirtualnego modelu instalacji, aby w szybki i skuteczny sposób móc ją monitorować i nią sterować

Effect of geometrical parameters of open microchannel surfaces on pool boiling heat transfer

This study focuses on the effect of channel depth on the heat transfer coefficient during nucleate pool boiling. Experimental studies were performed for saturated deionized water, and Novec-649 as working fluids at atmospheric pressure. Copper surfaces were modified to form microchannels with different geometrical properties. The microchannels were from 0.2 mm to 0.4 mm deep, 0.3 mm wide and spaced every 0.1 mm. The experiment was conducted for increasing heat flux up to the critical heat flux point. The surface modification provided an appreciably higher heat transfer coefficient compared to the smooth surface for all boiling liquids. The maximum heat transfer coefficient obtained exceeded 60 kW/m2K

HPV-type distribution and reproducibility of histological diagnosis in cervical neoplasia in Poland

This study was performed to assess attribution of high grade cervical intraepithelial neoplasia (HG-CIN) and invasive cervical cancer (ICC) to human papillomavirus (HPV) genotypes and secondarily to assess reproducibility of HG-CIN/ICC diagnosis obtained in Poland. Formaldehyde fixed, paraffin embedded blocks of HG-CIN/ICC from two distant institutions were sent to a central laboratory together with original histological diagnoses. Central/expert review of histopathological specimens was performed and agreement between local and central/expert diagnoses was calculated. HPV detection and genotyping in the samples was carried out with the use of SPF10-LiPA25 technology. Results were analyzed for 205 HG-CIN and 193 ICC cases with centrally confirmed diagnoses. Kappa coefficients and 95 % confidence intervals for HG-CIN and ICC diagnoses were: 0.13 (0.09;0.17) and 0.19 (0.11;0.26) respectively. Cohen’s kappa coefficients for lesions with representative number of samples ranged from 0.01 for cervical intraepithelial neoplasia grade 2 to 0.75 for adenocarcinoma. HPV DNA was detected in 96.1 and 91.2 % of the confirmed HG-CIN and ICC specimens respectively. HPV positive HG-CIN was most commonly attributed to HPV types: 16 (62.8), 33 (7.8), 31 (6.6), 52 (3.7), 45 (2.6) and 58 (2.6 %). HPV positive ICC was most commonly attributed to HPV types: 16 (72.1), 18 (10.8), 33 (5.7), 45 (3.4) and 31 (1.7 %). Reproducibility of histological diagnosis of HG-CIN/ICC obtained in Poland generally increases with the severity of lesion and is lowest for cervical intraepithelial neoplasia grade 2 and highest for adenocarcinoma. Over 80 % of ICC cases are vaccine-preventable in Poland

Supramolecular organization of liquid-crystal dimers-bis-cyanobiphenyl alkanes on HOPG by scanning tunneling microscopy

2D supramolecular organization of a series of six cyanobiphenyl bimesogens deposited on highly oriented pyrolytic graphite (HOPG) is studied by scanning tunneling microscopy (STM). The adsorbatesare 1,ω-bis(4-cyanobiphenyl-4’-yl)alkanes (CBnCB) with different length of their flexible alkyl spacer (containing 7 to 12 methylene groups). Microscopic investigations at the molecular resolution allow fordetailed analysis of the effect of the alkyl spacer length on the type and the extent of the resulting 2Dorganization. It has been demonstrated that bimesogens with shorter spacers (7 and 8 methylene units)organize in a similar manner characterized by the formation of two types of differently ordered monolayers: dense packed, wherein the molecules are oriented in one direction and ordered into parallel rows(layer structure), or less densely packed wherein they are organized into a chiral windmill-like structure. For derivatives with longer spacers (ranging from 9 to 12 methylene units) additional effect of parity of carbon atoms in the spacer (even versus odd) is observed. In this range of the spacer length even membered bimesogens are still organized in a typical layer structure. However, odd-membered dimers exhibit a much complex 2D supramolecular organization with a larger unit cell and a helical arrangement of the molecules. Careful comparison of this structure with the 3D structural data derived from the X-ray diffraction investigations of single crystals indicates that for these bimesogens a clear correlation exists between the observed complex 2D supramolecular organization in the monolayer and the organization in one of the crystallographic planes of the 3D nematic twist-bent phas

OCENA METROLOGICZNA SYSTEMU POMIAROWEGO DLA POTRZEB WYZNACZANIA UDZIAŁU FAZ W PRZEPŁYWIE MIESZANIN GAZ-CIECZ METODĄ TOMOGRAFII POJEMNOŚCIOWEJ 3D

The industrial diagnostic and monitoring systems require new methods offering the possibility of non-invasive observation and analysis of the two-phase gas-liquid mixtures flows. The designed new measurement system is dedicated for non-invasive percentage phase distribution calculation and flow structure identification in the vertical and horizontal pipelines. This paper presents some research  results of the metrological validation of the designed three-dimensional capacitance tomography measurement system including: the 3D ECT sensor structure optimization, the metrologicalanalysis of the image reconstruction process accuracy and the metrological analysis of the results of the phase distribution calculation method in comparison with other common technics. As a result of performed analysis the height capability of the 3D ECT measurement system for non-invasive real time dynamic flow processes identification was proved.  Przemysłowe systemy diagnostyki i monitorowania potrzebują nowych narzędzi oferujących możliwości nieinwazyjnej obserwacji i analizy procesów przepływów dwufazowych mieszanin gaz-ciecz. Opracowany system pomiarowy dedykowany jest dla potrzeb nieinwazyjnego wyznaczania procentowego udziału faz oraz identyfikacji struktur w przepływach dwufazowych w rurociągach pionowych i poziomych. Artykuł prezentuje wybrane rezultaty prac badawczych, w wyniku, których dokonano oceny własności metrologicznych prototypowego systemu trójwymiarowej tomografii pojemnościowej. Prace badawcze obejmowały między innymi: zagadnienie optymalizacji struktury czujnika ECT, a także metrologiczną ocenę dokładności rekonstrukcji obrazu oraz wyznaczania procentowego udziału faz w porównaniu z innymi metodami. W wyniku przeprowadzonej analizy wykazano dużą przydatność systemu 3D ECT do nieinwazyjnego, szybkiego diagnozowania dynamicznych procesów przepływowych