Tools for Forecasting and Optimizing the Tuning Parameter of the Low­speed Engine for Designing a Ship with the Kite

The developed simulation (stochastic) mathematical model for calculating fuel consumption of the main low-speed engine of a transport ship with a kite is proposed. The peculiarity of the model is the use of a number of initial probabilistic quantities such as wave height, wind speed, in the form of inverse integral distribution functions of their values. This makes it possible, using a generator of uniformly distributed pseudo-random numbers, to compute the arrays of possible values of the total fuel consumption of the main engine for the entire future operation and to determine the expected value of consumption. Such a simulation model with a pseudo-random number generator serves as a tool for comparing the fuel consumption of the alternative main engines, differing in the value of the “internal combustion engine – turbocharger” matching parameter. The minimum value of the total fuel consumption corresponds to the optimum value of the matching parameter.Due to the simulation mathematical model, the influence of the “internal combustion engine – turbocharger” matching parameter on the total fuel consumption for the 25-year operation period of the tanker with a deadweight of 26,470 t is investigated with the help of a computer. Its propulsion is provided by the 6S50ME-C7 engine and SkySails 640 m2 kite switched if the winds are favorable. It is found that the optimum matching parameter corresponds to a point on the propeller curve of the engine with a load coordinate of 60.5 % of the rated value. This refers to a round transatlantic voyage in the Northern Atlantic, mainly in temperate latitudes, with prevailing westerlies and northeast trade winds. Fuel economy in the liner shipping at speeds of about 13.5 knots for these conditions due to the use of the kite is 21 %, from the optimization of the mentioned parameter 3.4 % and in general 24.4 %. At the price of fuel for ship diesel engines of USD 322/ton, the expected value of fuel consumption reduction for the medium-range tanker for the specified period is USD 2,029.000 or USD 81,000/year

Downregulation of putative tumor suppressor gene TSC-22 in human brain tumors.

BACKGROUND AND OBJECTIVES: Our objective was to identify differentially expressed genes involved in the pathogenesis of glioblastoma multiforme (GBM). METHODS: Screening of arrayed human fetal brain and human postnatal brain cDNA libraries was performed by differential hybridization with glioblastoma multiforme and human normal brain cDNAs. RESULTS: Repeated differential hybridization of more than 100 cDNA clones selected by primary screening and analysis of RNA from adult normal brain and glial tumors showed 16 nucleotide sequences differentially expressed between normal brain and brain tumors. Among others, decreased content in astrocytic tumors was determined for TSC-22 mRNA corresponding to cDNA in the ICRFp507J1041 clone from human fetal brain cDNA library. Northern blot hybridization of RNA from different human brain tumors showed very low amounts of TSC-22 mRNA in most investigated samples of GBM, anaplastic astrocytoma, and some other tumors. Complete lack of expression of TSC-22 occurred in one sample of anaplastic astrocytoma, as well as in meningioma, brain sarcoma, sarcomatous meningioma, and oligodendroglioma. The differential expression of TSC-22 gene was confirmed by semiquantitative RT-PCR in 15 samples of astrocytomas WHO grade II-IV and three samples of normal brain. CONCLUSIONS: Significantly decreased levels of TSC-22 mRNA in human brain and salivary gland tumors and antiproliferative role of TSC-22 strongly suggest a tumor suppressor role for TSC-22. J