EFFECTS OF LOW-DOSE-GAMMA RAYS ON THE IMMUNE SYSTEM OF DIFFERENT ANIMAL MODELS OF DISEASE

We reviewed the beneficial or harmful effects of low-dose ionizing radiation on several diseases based on a search of the literature. The attenuation of autoimmune manifestations in animal disease models irradiated with low-dose γ-rays was previously reported by several research groups, whereas the exacerbation of allergic manifestations was described by others. Based on a detailed examination of the literature, we divided animal disease models into two groups: one group consisting of collagen-induced arthritis (CIA), experimental encephalomyelitis (EAE), and systemic lupus erythematosus, the pathologies of which were attenuated by low-dose irradiation, and another group consisting of atopic dermatitis, asthma, and Hashimoto’s thyroiditis, the pathologies of which were exacerbated by low-dose irradiation. The same biological indicators, such as cytokine levels and Tcell subpopulations, were examined in these studies. Low-dose irradiation reduced interferon (IFN)-gamma (γ) and interleukin (IL)-6 levels and increased IL-5 levels and the percentage of CD4+CD25+Foxp3+Treg cells in almost all immunological disease cases examined. Variations in these biological indicators were attributed to the attenuation or exacerbation of the disease’s manifestation. We concluded that autoimmune diseases caused by autoantibodies were attenuated by low-dose irradiation, whereas diseases caused by antibodies against external antigens, such as atopic dermatitis, were exacerbated

Ocrelizumab versus Interferon Beta-1a in Relapsing Multiple Sclerosis

Supported by F. Hoffmann–La Roche

Analysis of combustion parameters of a dual engine fuelled with CNG

W artykule przedstawiono wyniki badań parametrów procesu spalania w silniku dwupaliwowym zasilanym gazem ziemnym sprężonym (CNG). Parametry będące przedmiotem analizy obliczono na podstawie wykresów indykatorowych z badań jednocylindrowego silnika o zapłonie samoczynnym i wtrysku bezpośrednim 1CA90 zasilanego dwupaliwowo. Przedmiotem analizy było porównanie przebiegów ciśnienia,przyrostu ciśnienia, temperatury i szybkości wydzielania ciepła w czasie spalania przy zasilaniu dwupaliwowym i tradycyjnym. Ponadto przedstawiono wpływ wielkości dawki inicjującej i udziału paliwa gazowego na przebieg omawianych parametrów. Badania wykazały odmienny przebieg spalania paliwa gazowego zależny głównie od wielkości dawki inicjującej, obciążenia silnika i koncentracji paliwa gazowego w ładunku. Wnioski ogólne mogą być pomocne przy adaptacji silników o zapłonie samoczynnym do zasilania zarówno gazem ziemnym jak i innym paliwem gazowym o zbliżonym składzie.The results of research combustion parameters in the dual fuel engine fuelled with compression natural gas (CNG) have been presented in the paper. The analysed parameters were computed from indicator diagrams of the single cylinder pressure, increase of pressure, cylinder temperature and heat release rate in the combustion process in a dual fuel engine and a traditional diesel engine. It is presented the influence of a pilot liquid fuel charge and a gas fuel contribution on the change of studied parameters as well. The research results showed that different course of gas fuel combustion principally depends on the pilot fuel charge, engine load and gas fuel contribution. The general conclusions can be useful at adaptation of compression ignition engines to fuelling them with natural gas and other similar gas fuels

Dual fuelling CI engine with methanol and diesel oil

Dual fuel compression ignition engine can be run on diverse fuels, both gaseous and liquid ones. Alternative fuels to the Diesel oil feature, as a rule, low cetane number and high temperature of self-ignition. Due to this, such fuels can not be ignited spontaneously and require ignition from small dose of the Diesel oil. In the dual fuel system, as the main fuel can be considered a liquid fuels, which can be supplied to the cylinder in form of vapours, or injected be to the suction manifold. Methyl and ethyl alcohols, or their esters, can be counted among future fuels. Such alcohols can be either the main fuels or small additions improving combustion of the Diesel oil. In the paper are presented test results of the SW 680 engine run on methanol and Diesel oil. Methanol was supplied to the suction manifold in form of methanol-air aerosol. Energetic fraction of the methanol amounted to 12-50%, depending on engine load. Performed tests have shown advantageous effect of the methanol on performance of the engine. One confirmed considerable growth of overall efficiency of the engine in area of higher loads (3-6%), reduction of smokiness of exhaust gases achieved as early as with small additives of the methanol (2-3 times), reduction of CO and CO2 emissions, reduction of exhaust gases temperature. Small addition of the methanol affects advantageously on combustion of the Diesel oil, shortening time if its combustion. Addition of the methanol enables maintaining effective power of the engine fuelled traditionally, and even its slight growth. Cost of adaptation to dual fuel supply with alcohol are low, and such type of fuelling can be easy implemented in already operated compression ignition engines

Równomierność dawkowania oleju napędowego w silnikach dwupaliwowych

Adaptation of compression ignition engines to dual fuel supply can be accomplished both in case of modern engines equipped with common rail system and older engines equipped with classic injection system (piston pumps). Due to big differences in price of gaseous and liquid fuels there is observed a natural tendency to use very small initial doses. At current level of introduction of gaseous fuels to powering of traction engines there is a need to provide alternating fuelling of the engine with the Diesel only and in dual fuel system. It requires usage of original injection systems in the dual fuel engines, what largely restricts possibility of reduction of the initial doses. In the paper are presented investigations concerning uniformity of the dosing by in-line piston pump of the P56-01 type and two types of injectors with common rail system. The investigations have shown that the P56-01 pump adjusted for nominal doses shows big non-uniformity of the dosage in area of small doses. Improved uniformity of the dosage can be attained in result of adjustment for a smaller doses, what allows reduction of the dose to about 15-20% of nominal dose and improves smoothness of engine operation. Also in case of the injectors in common rail system, reduction of the doses is limited due to worsening of uniformity of the dosing from one cycle to another, and failure of the dosing. It results from the fact, that minimal doses in dual fuel system are smaller than the ones present in case of idling speed when the engine is run on the Diesel oil only. In case of the injectors in common rail system, minimal initial doses possible to be obtained are equal to 10-15% of the nominal dose.Adaptacja silników o zapłonie samoczynnym do zasilania dwupaliwowego może być dokonywana zarówno dla nowoczesnych silników z systemami common rail jak i starszych silników wyposażonych w klasyczną aparaturę wtryskową (pompy tłoczkowe). Ze względu na duże różnice cen paliw gazowych i ciekłych występuje naturalna tendencja do stosowania bardzo małych dawek inicjujących. Na obecnym poziomie wprowadzania paliw gazowych do zasilania silników trakcyjnych istnieje konieczność zachowania przemiennego zasilania silnika samym olejem napędowym i w systemie dwupaliwowym. Wymaga to zastosowania w silnikach dwupaliwowych oryginalnej aparatury wtryskowej co ogranicza w znacznym stopniu możliwość zmniejszania dawek inicjujących. W pracy przedstawiono badania równomierności dawkowania tłoczkowej pompy rzędowej P56-01 oraz dwóch typów wtryskiwaczy układu common rail. Badania pokazały, że pompa P56-01 wyregulowana dla dawek znamionowych wykazuje dużą nierównomierność dawkowania w zakresie małych dawek. Poprawę równomierności dawkowania można uzyskać przez regulacją pompy dla dawek mniejszych, co pozwala zmniejszyć dawkę do około 15-20% dawki znamionowej i poprawia równomierność pracy silnika. Również w przypadku wtryskiwaczy common rail zmniejszanie dawek jest ograniczone z powodu pogorszenia równomierności dawkowania z cyklu na cykl i zaniku dawkowania. Wynika to z faktu, że minimalne dawki w systemie dwupaliwowym są mniejsze od występujących dla wolnych obrotów przy zasilaniu samym olejem napędowym. W przypadku wtryskiwaczy common rail minimalne dawki inicjujące jakie można uzyskać wynoszą 10-15% dawki znamionowej

The possibility of quality improvement of gas-air mixture at part load of dual fuel engine

Jednym z zasadniczych problemów dwupaliwowych silników o zapłonie samoczynnym zasilanych olejem napędowym i gazem ziemnym jest pogarszająca się sprawność przy częściowych obciążeniach silnika. Zjawisko to związane jest z nadmiernym zubożeniem mieszaniny gazowej. W artykule przedstawiono wyniki badań dotyczące możliwości poprawy jakości spalania ubogich mieszanin gazowych przez dławienie powietrza dolotowego. Badania wykonano na badawczym, jednocylindrowym silniku o wtrysku bezpośrednim wyposażonym w układ wtryskowy oleju napędowego typu Common Rail i wtrysk sprężonego gazu do kolektora dolotowego. Badania wykazały korzystny wpływ umiarkowanego dławienia na sprawność ogólną silnika i stężenie CO oraz THC. Poprawa jakości spalania przy minimalnym obciążeniu prowadzi jednak do wzrostu stężenia NO[x] co powoduje konieczność równoczesnego stosowania recyrkulacji spalin.With one of fundamental problems of dual fuel diesel engines fed with diesel and natural gas there is a efficiency deteriorating at partial loads of the engine. This disadvantageous phenomenon is connected with combustion excessive lean air-gas mixtures. In the paper some results concerning the possibility of the improvement of quality combustion at low loads and lean mixtures, by inlet air throttling have been shown Experiments were made on single-cylinder direct injection research engine equipped with the arrangement of Common Rail system and the sequential injection of compressed gas to the inlet collector. A profitable influence of moderate throttling on the engine efficiency and CO and THC concentration has been demonstrated. However, the improvement in combustion quality lead NO[x] concentrations to the height at the partial load what is causing the necessity of simultaneous practicing the recirculation of the exhaust gas

Some aspects of dual fueling of the middle class modern CI engines

The paper presents results of studies on the dual fuel engine equipped with the Common Rail high pressure injection system and low pressure natural gas injection into the inlet collector. Impact of some regulation parameters of the feed system on the engine performance parameters was examined. Research of the pilot dose selection showed that the minimal size of the dose was limited to ca 12+13% of the nominal dose. It is a result of some troubles of the electromagnetic injector operation at short times of control. The effect of that is a notable deterioration of smoothness of the engine operation. However, electronic control of the injector opening timing enables to reduce the pilot dose size as the engine load is reduced. The research showed advantageous impact of the decreasing dose on the engine efficiency and exhaust gas toxicity at partial loads of the engine. The tests reconfirmed full usefulness of the system to combustion process optimization. A delay of the injection start at high engine loads enables to reduce nearly twice the NOx concentration in exhaust gas with insignificant decreasing, some 1+1.5%, of its efficiency. The used systems showed their high suitability to control charge quality in dual fuel engines, in traction applications in particular

Selected problems od application of natural gas to CI engine

W artykule omówiono niektóre problemy związane z zasilaniem silników o zapłonie samoczynnym gazem ziemnym sprężonym. Przedstawiono analizę opłacalności zasilania gazowego w silnikach autobusowych oraz wyniki badań stanowiskowych. Wnioski oparto na badaniach silnika 1CA90 zasilanego dwupaliwowo. Wykazały one, że w silniku o zapłonie samoczynnym możliwe jest zmniejszenie emisji tlenków azotu o około 35/45% oraz ponad 4-krotne zmniejszenie silnika. Ważną korzyścią ze stosowania gazu ziemnego jest ponadto zmniejszenie emisji CO2 w granicach 10/25%. System dwupaliwowy charakteryzuje się wysoką sprawnością silnika, porównywalną do sprawności silnika zasilanego olejem napędowym i znacznie wyższą od sprawności silników gazowych o zapłonie iskrowym.Forecasts for the nearest years anticipate significant increase of natural gas consumption in European Union states. Such situation is caused by pro-ecological capabilities of the gas, good deal of resources and common availability. It seams that at the present moment compressed natural gas shall find the main implementation. The present paper shows testing results of a single cylinder; direct injected dual fuel engine fed on compressed natural gas. In course of performed experiments it has been found that the engine operating in range of engine revolutions of 2000-2750 rpm at maximal load has reached higher thermal efficiencies comparing with engine fed traditionally.Usage of natural gas enables to significantly reduce NO[x], CO[2] emissions and smokiness of exhaust gases. Reduction of NO[x] emissions at maximal engine load has amounted to 35-45% with respect to emissions from an engine fed traditionally.Even bigger differences were observed at partial loads where reduction of NO[x] emissions was nearly threefold. The biggest differences in smokiness of exhaust gases were present at maximal load of dual fuel engine, where more than fourfold reduction of the smokiness has been observed. Dual fuel engines, however, have shown increased emissions of CO and non-burnt THC hydrocarbons. Growth of CO and THC emis.sions was nearly twice at maximal engine load and had increased at partial load. The reason of increased emissions of CO and THC is worsening of conditions of gas oxidation at partial load and increasing range of flame extinction near cylinder walls