1.ROZMIESZCZNIE CZUJNIKÓW STĘŻENIA METANU W WYBRANYCH WYROBISKACH KOPALŃ WĘGLA KAMIENNEGO 3.DANE POMIAROWE 4.PROGNOZY ZAGROŻENIA METANOWEGO 4.1.Wprowadzenie w zagadnienie prognozowania 4.2.Metody prognozy zagrożenia metanowego 5.WYDOBYCIE DOBOWE ZE ŚCIANY JAKO CZYNNIK KSZTAŁTUJĄCY STĘŻENIE METANU W JEJ REJONIE 5.1.Warunki górnicze w rejonie ściany N-6 w pokładzie 330/2 5.2.Prognoza średniego stężenia metanu na wylocie z rejonu ściany 6.PORÓWNANIE DOKŁADNOŚCI PROGNOZ STĘŻENIA METANU 6.1.Zastosowane modele prognostyczne 6.2.Charakterystyka danych pomiarowych i prognoz średniego stężenia metanu 6.4.Prognozy średniego stężenia metanu 6.5.Prognozy maksymalnego stężenia metanu

HUMAN SAFETY IN WORK ENVIRONMENT ON DECK OIL SPILL CLEAN-UP MATERIALS - SOLUTION FOR ENGINE ROOMS Agnieszka UBOWSKA, Katarzyna JOWTUCH 2.STUDENT APPRENTICESHIPS OF COURSE-OF-STUDY AND DIPLOMA-RELATED TYPES AS AN ELEMENT USED FOR RAISING THE PROFESSIONAL COMPETENCES OF ENGINEERS EDUCATED FOR THE NEEDS OF MARITIME AND INLAND SHIPPING INDUSTRY Anna E. WOLNOWSKA .Aleksandra SZABROŃSKA, Zbigniew MATUSZAK, Ondrej STOPKA 3.THE IMPACT OF THE BAN ON SPENDING WEEKLY REST IN THE VEHICLE ON TRANSPORT PLANNING IN THE EU Milos POLIAK, Patricia SIMURKOVA, Marek JAŚKIEWICZ, P. POSUNIAK, J. STOKŁOSA 4.SAFETY ASPECT IN CARRIAGE OF DANGEROUS GOODS BY RAILWAY TRANSPORT Beata DRZEWIENIECKA, Marzena NOWAK 5.SELECTED PROBLEMS OF SHIP SAFETY IN THE PROCESS OF DOCKING Magdalena KAUP, Dorota ŁOZOWICKA, Miroslav BLATNICKY 6.DEVELOPMENT OF LEARNERS' CREATIVITY POTENTIAL Alia MATUSZAK, Natalya UVARINA, Zbigniew MATUSZAK 7.ASSESSMENT OF THE CHANGES IN THE ECONOMY OF MUNICIPAL WASTE IN POLAND AFTER 2004 Joanna ZARĘBSKA, Iwona ŻABIŃSKA, Helena CIERNA, Erika SUJOVA 8.TRAFFIC SAFETY ON MAIN ROADS IN POLAND Rafał JURECKI, Miloś POLIAK 9.DIMENSIONING OF DANGER ZONES EMERGING AS A DOMINO EFFECT OF AN LNG EXPLOSION FOR INDUSTRIAL PLANTS LOCATED IN THE VICINITY OF INLAND TRANSPORT FAIRWAYS Agnieszka KALBARCZYK-JEDYNAK, Wojciech ŚŁĄCZKA 10.ANALYSIS OF THE REASONS FOR VIOLATION OF THE STANDARDS ON WORKING TIME BY PROFESSIONAL DRIVERS Andrzej ZUSKA 11.PHOTOBIOLOGICAL SAFETY OF INCANDESCENT LAMP REPLACEMENTS Andrzej PAWLAK 12.MODELLING SAFETY CULTURE AMONG CREWS OF SEAFARING VESSELS Andrzej ADAMKIEWICZ, Agata KRYSTOSIK-GROMADZIŃSKA OPERATING MACHINERY AND EQUIPMENT 13. MATHEMATICAL MODEL FOR PREDICTING THE SHIP SPEED IN THE ACTUAL WEATHER CONDITIONS ON THE PLANNED OCEAN ROUTE Tadeusz SZELANGIEWICZ, Katarzyna ŻELAZNY 14. USE OF THE CHIEF ENGINEERS EXPERIENCE TO PRIORITIZE OPERATIONAL TASKS IN THE SHIP ENGINE ROOM Piotr KAMIŃSKI THE IMPACT OF THE ROUTE OF TRANSPORT ON PRICE FORMATION IN ROAD FREIGHT TRANSPORT Marek JAŚKIEWICZ, Juraj HAMMER, Milos POLIAK 16.PROBABILISTIC-DETERMINISTIC METHOD OF RESCALING SHIP MANOEUVRING SIMULATION DATA DEFINING PARAMETERS OF FAIRWAY BENDS Stanisław GUCMA, Rafał GRALAK 17.CAPABILITIES OF LOCAL AND REMOTE MONITORING AND CONTROL OF EQUIPMENT USED IN MARINE SHIP INDUSTRY Agata ALBRECHT, Adam MUC 18.IMPACT OF DOCK TANKS PUMPING PLAN ON STRUCTURAL LOADS OF A DOCK AND A SHIP Przemysław RAJEWSKI 19.GRID TYPE IMPACT ON THE RESULTS OF THE VOLUME OF FLUID METHOD IN THE FREE SURFACE FLOW CALCULATIONS AROUND SHIP HULL Karol SUGALSKI, Tomaś SKRUCANY 20.SHIP'S OPERATIONAL SPEED ON THE PLANNED OCEAN ROUTE IN REAL WEATHER CONDITIONS Tadeusz SZELANGIEWICZ, Katarzyna ŻELAZNY 21.INTENSITY OF DANGEROUS PHONES FROM WAVES ON SELECTED OCEANIC ROUTES Tadeusz SZELANGIEWICZ, Katarzyna ŻELAZNY 22.HARMONIZATION OF MARKET CONDITIONS IN PROVISION OF ROAD FREIGHT TRANSPORT Milos POLIAK, Patricia SIMURKOVA, Marek JAŚKIEWICZ, Dariusz WIĘCKOWSKI 23.DANGEROUS PHONES ARISING FROM THE WAVES DURING THE OCEANIC ROUTE SHIP Tadeusz SZELANGIEWICZ, Katarzyna ŻELAZNY 24.REIMBURSEMENT OF EXCISE DUTY ON MINERALS OILS Marek JAŚKIEWICZ, Juraj HAMMER, Milos POLIAK, Dariusz WIĘCKOWSKI 25.UNIFICATION PROPOSAL ON MARKET ACCESS FOR FREIGHT FORWARDING IN THE EUROPEAN UNION Milos POLIAK, Patricia SIMURKOVA, Marek JAŚKIEWICZ, Salvador HERNANDEZ 26.SHIP ROUTE PROGRAMMING IN RESTRICTED AND COASTAL AREAS IN TROPICAL CYCLONE REGIONS Bernard WIŚNIEWSKI, Maciej SZYMAŃSKI 27.THE IMPACT OF TRANSPORT TIME ON THE CARRIER'S COSTS Milos POLIAK, Juraj HAMMER, Marek JAŚKIEWICZ, K. ZIELONKA, J. STOKŁOSA 28.SIGNIFICANCE ANALYSIS OF SHIP OPERATIONAL STATES AS A FACTOR INFLUENCING THE ENERGY EFFICIENCY OF A RESEARCH - TRAINING VESSEL Cezary BEHRENDT, Katarzyna PRILL, Marek PATSCH 29.AN ALGORITHM FOR DIAGNOSING INJECTION SYSTEMS OF MARINE ENGINES Artur BEJGER, Jan DRZEWIENIECKI 30.APPLICATION OF STEAM JET INJECTOR FOR LATENT HEAT RECOVERY OF MARINE STEAM TURBINE PROPULSION PLANT Szymon GRZESIAK, Andrzej ADAMKIEWICZ CONSTRUCTION AND OPERATION OF POWER MACHINES AND DEVICES 31DETERMINATION OF REGRESSION FORMULAS FOR KEY DESIGN CHARACTERISTICS OF CONTAINER SHIPS AT PRELIMINARY DESIGN STAGE Tomasz ABRAMOWSKI, Tomasz CEPOWSKI, Peter ZVOLENSKY 32ENERGY SAVING ENERGETIC SYSTEMS FOR COASTAL FISHING CUTTERS Cezary BEHRENDT, Dalibor BARTA 33EXPERIMENTAL RESEARCH ON THE CONCEPT OF USING AN AUTONOMOUS TRANSPORT MODULE FOR TRANSPORT FROM THE SEABED Wiktor FILIPEK, Krzysztof BRODA 34RESEARCH ON THE CONCEPT OF USING CALCIUM CARBIDE AS A SOURCE OF ENERGY FOR TRANSPORT FROM THE SEABED Wiktor FILIPEK, Krzysztof BRODA 35MODEL OF PROCESSES OF THE AL25/30 MARINE ENGINE AND ITS VERIFICATION Dominika CUPER-PRZYBYLSKA 36METHANE SLIP DURING CARGO OPERATIONS ON LNG CARRIERS AND LNG-FUELED VESSELS Jerzy HERDZIK 37THE INFLUENCE OF EXTERNAL FACTORS ON HAZARDS IN THE TRANSPORT PROCESSES OF SOYBEAN MEAL Beata DRZEWIENIECKA, Miroslav BLATNICKY 38THE USE OF TOPOLOGY OF IHBI INVERTERS IN PARALLEL OPERATION OF SHIP GENERATING SETS WITH PMSG GENERATORS Sergei GERMAN-GALKIN, Dariusz TARNAPOWICZ, Valentin S. TOMASOV 39WAYS OF ADJUSTING THE TWO-STROKE DIESEL ENGINE TO BE RUN ON LIQUEFIED NATURAL GAS Mariusz GIERNALCZYK, Filip LONSKI, Wojciech KANIAK 40ANALYSIS OF THE TOPOLOGY OF „SHORE TO SHIP" SYSTEMS - POWER ELECTRONIC CONNECTION OF SHIPS WITH LAND Dariusz TARNAPOWICZ, Sergei GERMAN-GALKIN 41CALCULATION OF OPERATIONAL INDICATOR EEOI FOR SHIPS DESIGNED TO OTHER PURPOSE THAN TRANSPORT BASED ON A RESEARCH -TRAINING VESSEL Katarzyna PRILL, Karol IGIELSKI 42FEA-ANALYSIS OF SHAFT AND SUPPORTS DEFORMATIONS FOR HUGE PRECISE LATHE. STATICS AND RESONANCES Stanislau DOUNAR, Alexandre LAKIMOVITCH, Andrei AUSIYEVICH, Andrzej JAKUBOWSKI341 43THE CONCEPTS OF INLAND PASSENGER TRANSPORT IN THE ODER RIVER BASIN Magdalena KAUP, Dorota LOZOWICKA 44THE METHOD OF ENERGY-EFFICIENCY INVESTIGATIONS OF THE NEWLY PRODUCED MARINE FUELS THROUGH AN APPLICATION OF THE LABORATORY DIESEL ENGINE Zbigniew KORCZEWSKI 45AN ESTIMATION OF THE FINAL PRICE OF CONTAINER SHIPS BASED ON MAIN SHIP PARAMETERS WITH THE USE OF NDCURVEMASTER CURVE FITTING SOFTWARE Tomasz CEPOWSKI 46FRETTING WEAR AS AN EXAMPLE OF DESTRUCTION OF RAILWAY VEHICLES WHEELSETS Marcin DĘBIŃSKI, Milos BREZANI 47THE INFLUENCE OF TEMPERATURE ON CHANGES IN THE DISTINGUISHING FEATURES OF THE USABLE QUALITY OF SOYBEAN MEAL Beata DRZEWIENIECKA, Miroslav BLATNICKY 48INFLUENCE OF THE SYMMETRY PLANE BOUNDARY CONDITION ON THE PLANING MULTIHULL CALM WATER RESISTANCE TEST CFD TO TOWING TANK COMPARISON Karol SUGALSKI 49THE DESTRUCTIVE EFFECT OF FINE FRACTIONS OF SOYBEAN MEAL IN TRANSPORT PROCESSES Beata DRZEWIENIECKA 50ALTERNATIVE PROPULSION PLANTS FOR MODERN LNG CARRIERS Szymon GRZESIAK 51EQUIPMENT EXPLOITATION IN POWER TO GAS INSTALLATION Janusz KOTOWICZ, Michał JURCZYK, Daniel WĘCEL 52ANALYSIS OF THE POSSIBILITY OF USING ACOUSTIC EMISSION FOR MONITORING TECHNICAL CONDITION OF THE FUEL INJECTOR IN 3AL25/30 ENGINE Krzysztof DUDZIK 53THE EMISSION AND COMBUSTION CHARACTERISTICS OF MARINE DIESEL ENGINE WITH EXTREME THROTTLED OF AIR OR EXHAUST DUCTS Jerzy KOWALSKI 54THE INFLUENCE OF LIQUID VISCOSITY ON ATOMIZED FUEL MEAN DROPLET SIZE DETERMINED BY THE LASER DIFFRACTION METHOD Paweł KRAUSE, Robert LABUDA 55APPLICATION OF REDUNDANCY IN SHIP POWER PLANTS OF OFFSHORE VESSELS Wiesław TAREŁKO 56THE USE OF A MATHEMATICAL MODEL OF MARINE DIESEL ENGINE IN A COMPUTER PROGRAM Artur BOGDANOWICZ, Tomasz KNIAZIEWICZ, Marcin ZACHAREWICZ 57ASSESSMENT OF SELECTED ON-BOARD BALLAST WATER TREATMENT SYSTEMS IN TERMS OF TECHNICAL AND OPERATIONAL PARAMETERS Marcin SZCZEPANEK, Cezary BEHRENDT 58IMPACT OF WAVES ON DANGEROUS STABILITY OF VESSELS ON THE OCEANIC ROUTE Tadeusz SZELANGIEWICZ, Katarzyna ŻELAZNY 59THE EFFECTS OF THE ADDITION OF VEGETABLE OIL ON THE VISCOSITY OF USED MARINE ENGINE OIL MARINOL RG 1240 Małgorzata MALINOWSKA 60ANALYSIS OF MARINE PISTON ENGINE INJECTORS DYNAMIC STATE FOR THE NON-INVASIVE DIAGNOSTICS PURPOSE Marek DUDZIŃSKI, Marcin KLUCZYK 61OPERATIONAL CHARACTERISTIC OF SELECTED MARINE TURBOUNITS POWERED BY STEAM FROM AUXILIARY OIL-FIRED BOILERS Cezary BEHRENDT, Rumen STOYANOV 62PRESENTATION OF THE PROPERTIES OF THE SUPERVISED MEASURING SYSTEM WITH FLEXIBLE SUPPORT OF CRANKSHAFTS IN APPLICATION TERMS Krzysztof NOZDRZYKOWSKI, Waldemar KOSTRZEWA, Elwira KAŁKOWSKA 63 ENERGY SAVING SYSTEMS OF HYDROSTATIC DRIVES FOR SHIP DECK MACHINES Grzegorz SKOREK 64 REDUNDANCY AS A WAY INCREASING RELIABILITY OF SHIP POWER PLANTS Wiesław TAREŁKO 65ENVIRONMENT PROTECTION POLICY AND MONITORING SYSTEMS FOR POLYMETALLIC NODULES EXPLOITATION Tomasz ABRAMOWSKI 66MECHATRONIC SYSTEM WITH THE CONTROL OF VOLTAGE IN PERMANENT MAGNET SYNCHRONOUS GENERATOR Dariusz TARNAPOWICZ, Sergei GERMAN-GALKIN 67EVOLUTION OF THE EXTRUDER SCREW-DISC DISC PLASTICIZING SYSTEM CONSTRUCTION Tomasz RYDZKOWSKI, Iwona MICHALSKA-POŻOGA, Marcin SZCZEPANEK, Vijay Kumar THAKUR 68EXPERIMENTAL RESEARCH OF SELF-IGNITION ENGINE FUELED BY MIXTURE OF DIESEL AND SINTETIC FUEL Oleh KLYUS, Anna SKARBEK-ŻABKIN, Nadezhda ZAMIATINA 69DETERMINING AND ANALYSING SUPPORT CONDITIONS AT VARIABLE CONSTRUCTION OF CRANKSHAFTS Krzysztof NOZDRZYKOWSKI, Zenon GRZĄDZIEL, Jozef HARUŚINEC 70METHODS OF ENERGY EFFICIENCY IMPROVEMENT BY MODERNISATION OF HYDRAULIC INSTALLATIONS AT A FISHING CUTTER AT THE BALTIC SEA Marcin SZCZEPANEK, Przemysław RAJEWSKI, Dalibor BARTA, Iwona MICHALSKA-POŻOGA 71APPLICATION THE RESULTS OF ENERGY EFFICIENCY AUDIT PLANNING AND IMPLEMENTATION OF FISHING VESSELS MODERNISATION Marcin SZCZEPANEK, Przemysław RAJEWSKI, Dalibor BARTA 72AVERAGE FUEL CONSUMPTION BY A SHIP ON A SALES LINE IN STATISTICAL WEATHER CONDITIONS Tadeusz SZELANGIEWICZ, Katarzyna ŻELAZNY 73SELECTED TRANSVERSE STABILITY PROBLEMS RELATED TO ARTICULATED VEHICLES BUILT TO CARRY LIQUID CARGO Marek JAŚKIEWICZ, Dariusz WIĘCKOWSKI 74MARITIME CONTAINERS REFRIGERATION PLANT FAULTS SURVEY Ewelina ZŁOCZOWSKA 75THEORETICAL RESEARCH ON THE GAS PHASE DENSITY CHANGE IN PROCESSES OCCURRING DURING WORK OF THE TRANSPORT MODULE INTENDED FOR TRANSPORT FROM THE SEABED Wiktor FILIPEK, Krzysztof BRODA 76THEORETICAL RESEARCH ON THE STABILITY OF THE TRANSPORT MODULE INTENDED FOR TRANSPORT FROM THE SEABED Wiktor FILIPEK, Krzysztof BRODA INTEGRATED MANAGEMENT SYSTEMS 77AUDIT AS A TOOL TO CONTROL THE FUNCTIONALITY OF SHIPS SAFETY MANAGEMENT SYSTEMS Elżbieta WOJNIŁKO 78LEAN MANAGEMENT - SYSTEM ASSUMPTIONS AND BARRIERS TO IMPLEMENTATION Tomasz RYDZKOWSKI, Iwona MICHALSKA-POŻOGA, Marcin SZCZEPANEK, Martin KENDRA 79OVERVIEW OF THE SHIP EFFICIENCY MANAGEMENT PLAN FOR A SEAFARING MODEL SHIP BASED ON THE IMO MEPC 231 (65) RESOLUTION Aleksandr WALISZYN, Andrzej ADAMKIEWICZ, Abdurashid YAFASOV 80 HOTEL INDUSTRY - REQUIREMENTS FOR HOTEL BUSINESS MANAGERS' PARTICIPATORY CULTURE ACQUISITION Inna PIASETSKAYA, Alla MATUSZAK INDUSTRIAL PRODUCTION PROCESSES 81SIMULATION OF THE PROCESS OF METAL HARDNESS MEASUREMENT BY THE ROCKWELL METHOD Stefan BERCZYŃSKI, Daniel GROCHALA, Zenon GRZĄDZIEL 82THE ASSEMBLY LOADS AND SOME STRENGTHENING METHODS OF THE PRODUCTS FROM POROUS MATERIAL WITH COILED WIRE Andrzej JAKUBOWSKI 83CONTEMPORARY COMPUTER SUPPORT DESIGN SOLUTIONS FOR INDUSTRIAL INFRASTRUCTURE Waldemar KOSTRZEWA, Elwira KAŁKOWSKA, Krzysztof NOZDRZYKOWSKI TECHNICAL EXPERIMENTAL EQUIPMENT FOR MAKING POROUS WIRE SAMPLES Andrzej JAKUBOWSKI, Stanislau DOUNAR 84A CHARACTERISTIC OF SELECTED PROPERTIES OF VULCANISED RUBBER ELEMENTS USED ON THE "Izabel" INLAND VESSEL Patrycja PAWŁOWSKA, Agnieszka DEJA, Zbigniew MATUSZAK, Katarzyna SOSIK, Maria CHOVANCOVA 86BULK MODULUS OF COPPER ALLOYS IN CONTEXT OF MODERN METAL THEORY Janusz CHRZANOWSKI, Bohdan BIEG 87 RESULTS OF A STUDY ON THE QUALITY OF CONICAL PICKS FOR PUBLIC PROCUREMENT PURPOSES Łukasz BOŁOZ

1.METODA OCENY PRZYDATNOŚCI DO PONOWNEGO ZAGOSPODAROWANIA ZASOBÓW ZANIECHANYCH LIKWIDOWANYCH KOPALŃ Marek Pieszczek, Janusz Smoliło, Andrzej Chmielą, Małgorzata Wysocka 2.PROFESOR DLA STUDENTA CZY STUDENT DLA PROFESORA ??? Wes Grebski, Michalene, Eva Grebski 3.INNOWACJE SPOŁECZNE - PRZYCZYNEK DO DALSZYCH BADAŃ Agnieszka Czerwińska-Lubszczyk 4.KIERUNEK PRZEBIEGU SPONTANICZNYCH PROCESÓW I ZJAWISK W ODOSOBNIONYCH UKŁADACH. RÓŻNE POJĘCIA ENTROPII Joachim Kozioł 5.DIAGNOSTYKA, W OCENIE STANU TECHNICZNEGO MASZYN I URZĄDZEŃ GÓRNICZYCH Stefan Czerwiński, Jan Kania 6.ZASTOSOWANIE INNOWACYJNEJ TECHNOLOGII INERTYZACJI ZROBÓW CZYNNEJ ŚCIANY WYDOBYWCZEJ B-34 POKŁ.407/1-2 Z UŻYCIEM GAZÓW UZYSKANYCH Z OCZYSZCZANIA SPALIN SILNIKA GAZOWEGO SPALAJĄCEGO METAN Łukasz Szlązak, Paweł Pawłowski, Marian Lasek, Zbigniew Czernecki, Antoni Jakubów 7.ZAKŁÓCENIA ZAAWANSOWANIA PROCESÓW RESTRUKTURYZACJI, REWITALIZACJI I LIKWIDACJI DUŻEJ KOPALNI WĘGLA KAMIENNEGO, WYWOŁANE PANDEMIĄ COVID-19 Andrzej Chmielą, Dariusz Wójcik, Małgorzata Wysocka 8.PROGNOZA STĘŻENIA METANU NA WYLOCIE ZE ŚCIANY ORAZ W CHODNIKU WENTYLACYJNYM - STUDIUM PRZYPADKU Henryk Badura 9.POMIARY RADONOWE W WYBRANYCH BUDYNKACH MIESZKALNYCH ZIEMI RYBNICKIEJ Jan Antoni Rubin, Daniel Wyciszczok, Łukasz Doleżych 10.MODERNIZACJA SYSTEMU ODPROWADZENIA WÓD OPADOWYCH Z BEZODPŁYWOWYCH NIECEK NA TERENIE ZLIKWIDOWANEJ KOPALNI Andrzej Chmielą, Stefan Czerwiński, Jan Kania, Małgorzata Wysocka 11.ANALIZA ZAGROŻEŃ AKUSTYCZNYCH ŚRODOWISKA W UJĘCIU DECYBELOWEJ ALGEBRY PRZETWORZEŃ WYNIKÓW POMIAROWYCH Wojciech Batko 12.WYKORZYSTANIE ENERGII GEOTERMALNEJ W MIEŚCIE BUK Jacek Zimny, Mieczysław Struś, Jakub Szymiczek, Krzysztof Szczotka 13.UTRZYMANIE RUCHU ORAZ EKSPLOATACJA MASZYN W PRZEMYŚLE 4.0 Tomasz Korbiel, Stefan Czerwiński, Jan Kania 14.WŁAŚCIWA KONTROLA WARUNKÓW PRACY JAKO STYMULATOR ZMNIEJSZENIA ZACHOROWALNOŚCI NA PYLICĘ PŁUC W GÓRNICTWIE WĘGLOWYM Kinga Mocek, Piotr Mocek 15.METODA PRZEDWSTĘPNEGO SZACOWANIA NAKŁADÓW ORAZ CZASU NIEZBĘDNEGO DO PRZEPROWADZENIA PROCESÓW LIKWIDACJI ZAKŁADU GÓRNICZEGO Andrzej Chmielą, Janusz Smoliło 16.TECHNICZNE ASPEKTY LIKWIDACJI SZYBÓW „GŁOWACKI" W RYBNIKU, ORAZ „JAS VI" I „JAS II" W JASTRZĘBIU ZDROJU Janusz Smoliło, Marek Pieszczek, Mieczysław Lubryka, Jerzy Grycman