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Open access

Andrzej Pawlak

Abstract

The article, based on the records of the EN 62471:2008, presents guidelines for photobiological safety of lamps and lamp systems. There are allowed safe exposure times presented and emission limit values for each of four risk groups, defined by the standard. The paper presents criteria for lamps irradiance or radiance measurement. Discussed risks with association of ultraviolet, visible and infrared radiation. For a detailed presentation of the potential risks associated with the blue light, there is made a comparison of spectra of selected light sources. On these basis, the blue light hazard assessment was presented for selected light sources.

Open access

Zbigniew Pawlak and Andrzej Smoleń

Valuation Methods of Sports Companies

The valuation of sports companies is indispensable during commercial buy and sell transactions, restructuring processes, determining premiums for the purposes of property insurance.

For the valuation of sports companies four approaches are possible i.e. assets-based, income-based, market-based and mixed-valuation approaches. For each approach there are specific company valuation methods. Using real-life examples, this paper discusses the following sports companies' valuation methods: book value, adjusted book value, replacement, liquidation, capitalized profit, discounted cash flow, comparative worth, market multiples and German valuation method. The mixed approach using the German method is applied when the output prices from conventional company valuation methods vary too much, and differences in values exceed 25%.

From the management accounting perspective the skilful application of valuation methods to sports companies should be regarded as one of the prerequisites for effective management of sports companies.

Open access

Marta Siemieniec, Hanna Kierzkowska-Pawlak and Andrzej Chacuk

Reaction Kinetics of Carbon Dioxide in Aqueous Diethanolamine Solutions Using the Stopped-Flow Technique

The pseudo-first-order rate constants (kOV) for the reactions between CO2 and diethanolamine have been studied using the stopped-flow technique in an aqueous solution at 293, 298, 303 and 313 K. The amine concentrations ranged from 167 to 500 mol·m-3. The overall reaction rate constant was found to increase with amine concentration and temperature. Both the zwitterion and termolecular mechanisms were applied to correlate the experimentally obtained rate constants. The values of SSE quality index showed a good agreement between the experimental data and the corresponding fit by the use of both mechanisms.

Open access

Hanna Kierzkowska-Pawlak, Marta Siemieniec and Andrzej Chacuk

Reaction kinetics of CO2 in aqueous methyldiethanolamine solutions using the stopped-flow technique

The kinetics of the reaction between CO2 and methyldiethanolamine in aqueous solutions have been studied using the stopped-flow technique at 288, 293, 298 and 303 K. The amine concentration ranged from 250 to 875 mol·m-3. The overall reaction rate constant was found to increase with amine concentration and temperature. The acid base catalysis mechanism was applied to correlate the experimentally determined kinetic data. A good agreement between the second order rate constants for the CO2 reaction with MDEA computed from the stopped-flow data and the values reported in the literature was obtained.

Open access

Aleksandra Pawlak, Bożena Obmińska-Mrukowicz, Iwona Zbyryt and Andrzej Rapak

Abstract

Introduction: Due to the high heterogeneity of canine lymphoma, the aim of the present study was to test in vitro the chemosensitivity of canine high-grade primary lymphoma cells to various cytostatic drugs commonly used to treat dogs: 4-HO-cyclophosphamide, doxorubicin, dexamethasone, prednisolone, vincristine, etoposide, chlorambucil, lomustine, and cytosine arabinoside. Material and Methods: To determine the cell viability and drug ability to induce apoptosis two different tests were used: an MTT assay and annexin V/propidium iodide staining. Results: Both in vitro tests were found to be useful tools. Significant differences in the sensitivity, depending on the drug type, between B-, T- and mixed/null-type lymphoma cells were found for the majority of the tested drugs. B-type cells were the most sensitive in vitro, whereas T-type cells seemed to be the most resistant. Doxorubicin, chlorambucil, etoposide, and vincristine most strongly reduced the cell viability and induced apoptosis. Conclusion: In vitro assays, such as the MTT test and especially the annexin V/PI assay, may be useful tools for predicting a response to the treatment of high-grade lymphoma in dogs or improving the treatment outcomes in individual animals.

Open access

Andrzej Pawlak and Małgorzata Zalesińska

Abstract

The article describes test results that provided the ground to define and evaluate basic photometric, colorimetric and electric parameters of selected, widely available light sources, which are equivalent to a traditional incandescent 60-Watt light bulb. Overall, one halogen light bulb, three compact fluorescent lamps and eleven LED light sources were tested. In general, it was concluded that in most cases (branded products, in particular) the measured and calculated parameters differ from the values declared by manufacturers only to a small degree. LED sources prove to be the most beneficial substitute for traditional light bulbs, considering both their operational parameters and their price, which is comparable with the price of compact fluorescent lamps or, in some instances, even lower.

Open access

Andrzej Wilk, Lucyna Więcław-Solny, Dariusz Śpiewak, Tomasz Spietz and Hanna Kierzkowska-Pawlak

Abstract

Amine absorption processes are widely used in the industry to purify refinery gases, process gases or natural gas. Recently, amine absorption has also been considered for CO2 removal from flue gases. It has a number of advantages, but there is one major disadvantage - high energy consumption. This can be reduced by using an appropriate sorbent. From a group of several dozen solutions, three amine sorbents were selected based on primary, tertiary and sterically hindered amines. The solutions were used to test CO2 absorption capacity, absorption kinetics and heat of CO2 absorption. Additional tests were performed on the actual absorber-desorber system to indicate the most appropriate sorbent for capturing CO2 from flue gases.

Open access

Andrzej Lehmann, Jacek Piątkowski, Mariusz Nowak, Marek Jackowski, Maciej Pawlak, Mieczysław Witzling and Maciej Śmietański

Abstract

Inguinal hernia repair and cholecystectomy are amongst the most common surgical procedures performed worldwide. In the recent decades, early disease detection has notably increased due to easily accessible ultrasound.

The aim of the study was to assess the safety and the possibility of performing a simultaneous hernia repair and cholecystectomy using the laparoscopic approach.

Material and methods. Eight patients (M=100%) with inguinal hernia (3 with bilateral hernia) and cholelithiasis were included in the study. The presence of gallstones was confirmed by imaging. Mean age of the patients was 61.75 years (ranging from 47-72). Simultaneous laparoscopic cholecystectomy and transabdominal pre-peritoneal hernia repair was performed in all patients. Postoperative complications were analyzed to assess the safety and feasibility of the procedure.

Results. Mean operating time was 55 minutes (ranging from 30-60) and average length of stay was 3.625 days (ranging from 2-7). In order to perform a cholecystectomy, 1-2 additional trocars were used. No intra-operative complications were observed. At a follow-up visit on postoperative day 7, a small hematoma (10 ml of blood was punctured) in the right groin was noted in one patient. Another patient developed fever postoperatively, treated conservatively with antibiotics.

Conclusions. Simultaneous TAPP and cholecystectomy proved to be a safe and feasible procedure. Acceptable operating time and hospital stay, as well as lack of influence on the length of convalescence, may present an interesting alternative to two separate procedures

Open access

Marcin Błaszczyk, Helena Hercman, Jacek Pawlak, Michał Gąsiorowski, Šárka Matoušková, Marta Aninowska, Ditta Kicińska and Andrzej Tyc

Abstract

The quality of paleoenvironmental reconstruction based on speleothem records depends on the accuracy of the used proxies and the chronology of the studied record. As far as the dating method is concerned, in most cases, the best solution is the use of the U-series method to obtain a precise chronology. However, for older periods (i.e., over 0.5 Ma), dating has become a serious challenge. Theoretically, older materials could be dated with the U-Pb dating method. However, that method requires a relatively high uranium content (minimum of several ppm), whereas typical speleothems from Poland (and all of Central Europe) have uranium concentrations below 0.1 ppm. Because the materials in Polish caves are problematic, we applied oxygen isotope stratigraphy (OIS) as a tool for speleothem dating. By using OIS as an alternative tool to create a chronology of our flowstone, it was found that the studied flowstone crystallized from 975 to 470 ka with three major discontinuities, so obtained isotopic record can be correlated with oxygen isotopic stages from MIS 24 to MIS 12. The observed isotopic variability was also consistent and confirmed with the petrographic observations of the flowstone.

Open access

Marek Krawczyk, Michał Grąt, Krzysztof Barski, Joanna Ligocka, Arkadiusz Antczak, Oskar Kornasiewicz, Michał Skalski, Waldemar Patkowski, Paweł Nyckowski, Krzysztof Zieniewicz, Ireneusz Grzelak, Jacek Pawlak, Abdulsalam Alsharabi, Tadeusz Wróblewski, Rafał Paluszkiewicz, Bogusław Najnigier, Krzysztof Dudek, Piotr Remiszewski, Piotr Smoter, Mariusz Grodzicki, Michał Korba, Marcin Kotulski, Bartosz Cieślak, Piotr Kalinowski, Piotr Gierej, Mariusz Frączek, Łukasz Rdzanek, Rafał Stankiewicz, Konrad Kobryń, Łukasz Nazarewski, Dorota Leonowicz, Magdalena Urban-Lechowicz, Anna Skwarek, Dorota Giercuszkiewicz, Agata Paczkowska, Jolanta Piwowarska, Remigiusz Gelo, Paweł Andruszkiewicz, Anna Brudkowska, Renata Andrzejewska, Grzegorz Niewiński, Beata Kilińska, Aleksandra Zarzycka, Robert Nowak, Cezary Kosiński, Teresa Korta, Urszula Ołdakowska-Jedynak, Joanna Sańko-Resmer, Bartosz Foroncewicz, Jacek Ziółkowski, Krzysztof Mucha, Grzegorz Senatorski, Leszek Pączek, Andrzej Habior, Robert Lechowicz, Sławomir Polański, Elżbieta Leowska, Ryszard Pacho, Małgorzata Andrzejewska, Olgierd Rowiński, Sławomir Kozieł, Jerzy Żurakowski, Bogna Ziarkiewicz-Wróblewska, Barbara Górnicka, Piotr Hevelke, Bogdan Michałowicz, Andrzej Karwowski and Jerzy Szczerbań

1000 Liver Transplantations at the Department of General, Transplant and Liver Surgery, Medical University of Warsaw - Analysis of Indications and Results

The aim of the study was to analyze indications and results of the first one thousand liver transplantations at Chair and Clinic of General, Transplantation and Liver Surgery, Medical University of Warsaw.

Material and methods. Data from 1000 transplantations (944 patients) performed at Chair and Clinic of General, Transplantation and Liver Surgery between 1994 and 2011 were analyzed retrospectively. These included 943 first transplantations and 55 retransplantations and 2 re-retransplantations. Frequency of particular indications for first transplantation and retransplantations was established. Perioperative mortality was defined as death within 30 days after the transplantation. Kaplan-Meier survival analysis was used to estimate 5-year patient and graft survival.

Results. The most common indications for first transplantation included: liver failure caused by hepatitis C infection (27.8%) and hepatitis B infection (18%) and alcoholic liver disease (17.7%). Early (< 6 months) and late (> 6 months) retransplantations were dominated by hepatic artery thrombosis (54.3%) and recurrence of the underlying disease (45%). Perioperative mortality rate was 8.9% for first transplantations and 34.5% for retransplantations. Five-year patient and graft survival rate was 74.3% and 71%, respectively, after first transplantations and 54.7% and 52.9%, respectively, after retransplantations.

Conclusions. Development of liver transplantation program provided more than 1000 transplantations and excellent long-term results. Liver failure caused by hepatitis C and B infections remains the most common cause of liver transplantation and structure of other indications is consistent with European data.