12,423 research outputs found

    Disturbing effect of free hydrogen on fuel combustion in internal combustion engines

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    Experiments with fuel mixtures of varying composition, have recently been conducted by the Motor Vehicle and Airplane Engine Testing Laboratories of the Royal Technical High School in Berlin and at Fort Hahneberg, as well as at numerous private engine works. The behavior of hydrogen during combustion in engines and its harmful effect under certain conditions, on the combustion in the engine cylinder are of general interest. Some of the results of these experiments are given here, in order to elucidate the main facts and explain much that is already a matter of experience with chauffeurs and pilots

    The symptomatic treatment of polycythemia vera

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    Thesis (M.A.)--Boston Universit

    On some derivatives of phenylethers, 2

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    Products and the synthesis of chloronitrobenzol with certain phenolates are discussed, as is the p-oxyphenylether occasionally produced. Yield, melting point, and physical description are given for each product. The products include 2,4'-dinitrophenylether; 2,2'-dinitrophenylether; p-nitrophenylether-p-oxybenzoic acid and its methylester; p-aminophenylether-p-oxybenzoic acid, its sulfate, and its barium salt; and p-oxypenylether

    Research into the process of preparation of Ukrainian coal by the oil aggregation method

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    We conducted a study into concentration of Donetsk coal with varying degrees of coalification – anthracite and grade G – by the method of oil aggregation. We determined the character of impact of the following factors on the results of oil aggregation of coal: the ash content of original coal, pulp agitation duration, pulp density, consumption and type of reagent-binder. The research demonstrated a possibility of effective preparation of finely- and thinly dispersed Donetsk coal the size of 0–0.1; 0–1(2) mm and ash content from 10–15 % to 65–70 % by the method of oil aggregation. In this case, it was established that with an increase in the ash content of original coal, the process of oil aggregation displays a capacity of self-leveling. By reducing the speed of aggregation, it is possible to attain practically stable technological results over the entire examined range of ash content of original coal – from 10–15 % to 65–70 %. Obtained results substantiate the possibility of employing the process of oil aggregation for the re-preparation of waste, in particular, waste of flotation and gravitation separation of coal preparation.Досліджено збагачення донецького вугілля різного ступеня вуглефікації масляною агрегацією. Встановлено вплив на результати процесу зольності вугілля, тривалості агітації, густини пульпи, витрат і виду реагенту. Показано можливість ефективного збагачення вугілля крупності 0–0,1 (2) мм, зольності 10–70 % і самовирівнювання масляної агрегації при збільшенні зольності. Обгрунтовано застосування масляної агрегації для перезбагачення відходів флотації

    Synthesis and viscosity behavior of poly(γ-p-biphenylmethyl-L-glutamate) in benzene/dichloroacetic acid mixtures, a comparison with poly(γ-benzyl-L-glutamate)

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    The synthesis of poly(γ-p-biphenylmethyl-L-glutamate), PBPLG, (poly{L-imino-1-[2-(4-biphenylylmethoxycarbonyl)ethyl]-2-oxoethylene}), (1d) is described. The viscosity behavior of this polymer in benzene/dichloroacetic acid mixtures (c=0,2.10 -3 - 1,4.10 -3 g/cm3) at 25°CC is investigated. The results are compared with measurements on poly(γ-benzyl-L-glutamate), PBLG, (poly[L-imino-1-(2-benzyloxycarbonylethyl)-2-oxoethylene]), (1c) under the same conditions. A transition from a rigid hydrogen bonded helix to a random solvated coil occurs in two stages for both: PBPLG (first stage 0-55%, second stage 55-100% dichloroacetic acid) and PBLG (first stage 0-70%, second stage 70-100% dichloroacetic acid). \ud Therefore, the introduction of a p-phenyl substituent in PBLG leads to a less stable helix in benzene/dichloroacetic acid mixtures. \ud The stability and viscosity behavior of PBLG in benzene/dichloroacetic acid mixtures (c=0,2.10 - 3 - 1,4.10 - 3g/cm3) is quite similar to the behavior of PBLG in m-cresol/dichloroacetic acid mixtures (c=1,0.10 - 3 - 4,0.10 - 3 g/cm3)

    Research into the process of preparation of Ukrainian coal by the oil aggregation method

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    We conducted a study into concentration of Donetsk coal with varying degrees of coalification – anthracite and grade G – by the method of oil aggregation. We determined the character of impact of the following factors on the results of oil aggregation of coal: the ash content of original coal, pulp agitation duration, pulp density, consumption and type of reagent-binder. The research demonstrated a possibility of effective preparation of finely- and thinly dispersed Donetsk coal the size of 0–0.1; 0–1(2) mm and ash content from 10–15 % to 65–70 % by the method of oil aggregation. In this case, it was established that with an increase in the ash content of original coal, the process of oil aggregation displays a capacity of self-leveling. By reducing the speed of aggregation, it is possible to attain practically stable technological results over the entire examined range of ash content of original coal – from 10–15 % to 65–70 %. Obtained results substantiate the possibility of employing the process of oil aggregation for the re-preparation of waste, in particular, waste of flotation and gravitation separation of coal preparation.Досліджено збагачення донецького вугілля різного ступеня вуглефікації масляною агрегацією. Встановлено вплив на результати процесу зольності вугілля, тривалості агітації, густини пульпи, витрат і виду реагенту. Показано можливість ефективного збагачення вугілля крупності 0–0,1 (2) мм, зольності 10–70 % і самовирівнювання масляної агрегації при збільшенні зольності. Обгрунтовано застосування масляної агрегації для перезбагачення відходів флотації

    “Do Not Kill Guinea Pig before Setting up Apparatus”: The Kymograph's Lost Educational Context

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    The objects of science education are transformed, degraded and disappeared for many reasons, and sometimes take other things with them when they go. This close reading of an undergraduate physiology laboratory report demonstrates how the kymograph was never a stand-alone instrument, but intertwined with conceptual frameworks and technical skills, laboratory amenities, materials, animal supply, technicians. Replacing the obsolete kymograph entails changing all of that, though our usual stories are focussed on progress associated with better measurements with fewer complications, not complications themselves. Such interconnectedness between progress and demise raises uncomfortable challenges for laboratory pedagogy, and for museum practice: what is laboratory education really about, and what kinds of heritage should museums, libraries and archives preserve to document it
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