273 research outputs found

    Laser ignition of high-energy materials containing AlB[2] and AlB[12] powders

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    Boron-containing substances are known to have high gravimetric and volumetric heats of oxidation in comparison with any metals that make them promising for using in high-energy materials. This work is aimed to study ignition characteristics of ammonium perchlorate and nitrate-based composite solid propellants containing aluminium borides by means of radiative heating by CO[2]-laser. It was found that the effect upon laser ignition (ignitability) at full replacement of ASD-4 aluminum powder by aluminium diboride and dodecaboride is close. The ignition time of HEM is reduced by 2.0–2.5 times compared with ASD-4 HEM sample in the heat flux density range of 90–200 W/cm{2}

    ΠžΡ†Π΅Π½ΠΊΠ° влияния биологичСских ΠΈ физичСских Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ Π½Π° качСство ΠΏΠ»Π°Π½ΠΎΠ² Π»ΡƒΡ‡Π΅Π²ΠΎΠΉ Ρ‚Π΅Ρ€Π°ΠΏΠΈΠΈ с ΠΎΠ΄Π½ΠΎΠ²Ρ€Π΅ΠΌΠ΅Π½Π½ΠΎΠΉ эскалациСй Π΄ΠΎΠ·Ρ‹ ΠΎΠΏΡƒΡ…ΠΎΠ»Π΅ΠΉ ΠΏΡ€Π΅Π΄ΡΡ‚Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΠΉ ΠΆΠ΅Π»Π΅Π·Ρ‹

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    ЦСлью Π΄Π°Π½Π½ΠΎΠΉ Ρ€Π°Π±ΠΎΡ‚Ρ‹ являСтся исслСдованиС ΠΈ ΠΎΡ†Π΅Π½ΠΊΠ° влияния биологичСских ΠΈ физичСских Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ Π½Π° качСство ΠΏΠ»Π°Π½ΠΎΠ² Π»ΡƒΡ‡Π΅Π²ΠΎΠΉ Ρ‚Π΅Ρ€Π°ΠΏΠΈΠΈ с ΠΎΠ΄Π½ΠΎΠ²Ρ€Π΅ΠΌΠ΅Π½Π½ΠΎΠΉ эскалациСй Π΄ΠΎΠ·Ρ‹ ΠΎΠΏΡƒΡ…ΠΎΠ»Π΅ΠΉ ΠΏΡ€Π΅Π΄ΡΡ‚Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΠΉ ΠΆΠ΅Π»Π΅Π·Ρ‹. Π’ Ρ€Π°ΠΌΠΊΠ°Ρ… Π΄Π°Π½Π½ΠΎΠ³ΠΎ исслСдования Π±Ρ‹Π»ΠΈ рассмотрСны дозимСтричСскиС ΠΏΠ»Π°Π½Ρ‹ 9 ΠΏΠ°Ρ†ΠΈΠ΅Π½Ρ‚ΠΎΠ² с Π΄ΠΈΠ°Π³Π½ΠΎΠ·ΠΎΠΌ Ρ€Π°ΠΊ ΠΏΡ€Π΅Π΄ΡΡ‚Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΠΉ ΠΆΠ΅Π»Π΅Π·Ρ‹. ВСрапСвтичСскиС ΠΏΠ»Π°Π½Ρ‹ созданы Π½Π° основС дозимСтричСских ΠΊΡ€ΠΈΡ‚Π΅Ρ€ΠΈΠ΅Π² для ΠΊΠ°ΠΆΠ΄ΠΎΠ³ΠΎ клиничСского случая с Ρ€Π°Π·Π½Ρ‹ΠΌΠΈ функциями ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ: физичСскиС, биологичСскиС, комбинация физичСских ΠΈ биологичСских Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ

    Features of thermal behavior and ignition of HEM with bimetal powders

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    The use of metal fuel in high-energy materials (HEM) for propulsion is the most energy efficient method allows to the combustion characteristic increase for solid propellants and specific impulse. Aluminum powder is used in original HEM. To improve the ignition characteristics of HEM advisable to use the catalyst (nonmetals, metals or their oxides). Paper presents the experimental data of the thermal behavior and ignition for HEM based on AP and butadiene rubber, containing bimetal powders: aluminum/iron and aluminum/boron. The use of Alex/Fe powder in HEM decreases the ignition time by 1.3-1.9 times under initiation by CO[2] laser in air at the range of heat flux density of 55-220 W/cm{2} and increases of the recoil force of gasification products outflow from burning surface by 27 % during combustion of propellant due to possible of the catalytic effect, which reduces the beginning temperature of AP high-temperature decomposition by ~20 Β°C, and interaction of thermite mixture of aluminum and iron particles in the reaction layer of propellant. Then the use of Alex/B in HEM the ignition time is decreased by 1.2-1.4 times, the recoil force of gasification products outflow from burning surface is slightly increased by 9 %

    The results of laboratory researches on the patients with obstructive pulmonary disease – the liquidators of the accident at the chernobyl nuclear power plant before the treatment

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    European Academy of Neurology/Movement Disorder Society - European Section guideline on the treatment of Parkinson's disease: I. Invasive therapies

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    BACKGROUND AND PURPOSE: This update of the treatment guidelines was commissioned by the European Academy of Neurology and the European section of the Movement Disorder Society. Although these treatments are initiated usually in specialized centers, the general neurologist and general practitioners taking care of PD patients should know the therapies and their place in the treatment pathway. METHODS: Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was used to assess the spectrum of approved interventions including deep brain stimulation (DBS) or brain lesioning with different techniques (radiofrequency thermocoagulation, radiosurgery, magnetic resonance imaging-guided focused ultrasound surgery [MRgFUS] of the following targets: subthalamic nucleus [STN], ventrolateral thalamus, and pallidum internum [GPi]). Continuous delivery of medication subcutaneously (apomorphine pump) or through percutaneous ileostomy (intrajejunal levodopa/carbidopa pump [LCIG]) was also included. Changes in motor features, health-related quality of life (QoL), adverse effects, and further outcome parameters were evaluated. Recommendations were based on high-class evidence and graded in three gradations. If only lower class evidence was available but the topic was felt to be of high importance, clinical consensus of the guideline task force was gathered. RESULTS: Two research questions have been answered with eight recommendations and five clinical consensus statements. Invasive therapies are reserved for specific patient groups and clinical situations mostly in the advanced stage of Parkinson's disease (PD). Interventions may be considered only for special patient profiles, which are mentioned in the text. Therapy effects are reported as change compared with current medical treatment. STN-DBS is the best-studied intervention for advanced PD with fluctuations not satisfactorily controlled with oral medications; it improves motor symptoms and QoL, and treatment should be offered to eligible patients. GPi-DBS can also be offered. For early PD with early fluctuations, STN-DBS is likely to improve motor symptoms, and QoL and can be offered. DBS should not be offered to people with early PD without fluctuations. LCIG and an apomorphine pump can be considered for advanced PD with fluctuations not sufficiently managed with oral treatments. Unilateral MRgFUS of the STN can be considered for distinctly unilateral PD within registries. Clinical consensus was reached for the following statements: Radiosurgery with gamma radiation cannot be recommended, unilateral radiofrequency thermocoagulation of the pallidum for advanced PD with treatment-resistant fluctuations and unilateral radiofrequency thermocoagulation of the thalamus for resistant tremor can be recommended if other options are not available, unilateral MRgFUS of the thalamus for medication-resistant tremor of PD can be considered only within registries, and unilateral MRgFUS of the pallidum is not recommended. CONCLUSIONS: Evidence for invasive therapies in PD is heterogeneous. Only some of these therapies have a strong scientific basis. They differ in their profile of effects and have been tested only for specific patient groups

    Analysis of a distinct speech disorder seen in chronic manganese toxicity following Ephedrone abuse

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    INTRODUCTION: In the last fifteen years a new cause of chronic manganese toxicity has been recognized. It follows recreational intravenous injections of Ephedrone, synthesized from a cold remedies contained pseudoephedrine. Potassium permanganate is used as an oxidant. It presents with severe parkinsonism-dystonia and a characteristic dysarthria. OBJECTIVES: We performed a focus perceptual study of dysarthria in Ephedrone induced parkinsonism and compared the findings with the speech disorders seen in Parkinson's disease (PD) and Progressive Supranuclear Palsy (PSP). METHODS: A digital voice recording, perceptual speech analysis (Darley, 1975) [18], serial neurological assessment and Brain Magnetic Resonance (MR) imaging were performed at the Lviv regional Clinical Hospital. The results were analysed at the Institute of Neurology in London. RESULTS: Dysarthria developed after 8.5 Β± 3.2 months of daily intravenous Ephedrone abuse and was an initial symptom in a third of cases. It was characterised by a robotic-flat prosody, whispering or continuous phonation, an inability to regulate pitch and volume, frozen lip articulation, a variable degree of dystonic tightness, difficulties in speech initiation and palladia, There was no nasality and swallowing was normal. In some patients speech deteriorated even after the discontinuation of Ephedrone. MR imaging, performed soon after drug cessation showed T1 signal hyperintesity in striatum and pallidum, especially in the Globus Pallidum interna. CONCLUSION: Ephedrone induced chronic manganese toxicity can lead to a mixed hypokinetic-dystonic dysarthria with a distinct dystonic pattern. Perceptual speech analysis can be a helpful ancillary investigation in the differential diagnosis of parkinsonism, and may permit the recognition of chronic manganese toxicity

    The first experience of using kinesiotaping in the treatment of symphysiopathy in women in the second half of pregnancy

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    The aim of the study - to evaluate the effectiveness of kinesiotaping in reducing the level of pain in pregnant symphysiopathyЦСль исслСдования - ΠΎΡ†Π΅Π½ΠΈΡ‚ΡŒ ΡΡ„Ρ„Π΅ΠΊΡ‚ΠΈΠ²Π½ΠΎΡΡ‚ΡŒ кинСзиотСйпирования Π² сниТСнии уровня Π±ΠΎΠ»ΠΈ ΠΏΡ€ΠΈ симфизиопатии Π±Π΅Ρ€Π΅ΠΌΠ΅Π½Π½Ρ‹
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