scholarly journals The Tribodiagnostics of the Technical Condition of the Helicopter Main Reduction Gear

2015 ◽  
Author(s):  
L.A. Shabalinskaia ◽  
V.V. Golovanov ◽  
E.S. Bubnova ◽  
L.V. Milinis
Keyword(s):  
Morphological Analysis ◽  
Spectroscopic Analysis ◽  
Wear Particle ◽  
Technical Condition ◽  
Reduction Gear ◽  
Early Diagnostics ◽  
Particle Count ◽  
Tribological Tests ◽  
Operational Life

This work is about the possibility of early diagnostics of the technical condition of the main reduction gear in the helicopter. Tribological tests of oil samples taken when testing the operational life are conducted based on the analytical ferrography, morphological analysis, wear particle count, and spectroscopic analysis.

The study of the possibility of the tribodiagnostics of the technical condition of the helicopter main reduction gear

2015 ◽  
Vol 36 (1) ◽  
pp. 96-101 ◽  
Author(s):  
L. A. Shabalinskaya ◽  
V. V. Golovanov ◽  
E. S. Bubnova ◽  
L. V. Milinis
Keyword(s):  
Technical Condition ◽  
Reduction Gear

scholarly journals Application of diagnostics-in-place for determining technical condition of turbo-gear unit reduction gear of Sevmorput LASH carrier

2020 ◽  
Vol 2020 (2) ◽  
pp. 7-14
Author(s):  
Konstantin Olegovich Sergeev ◽  
Tatiana Pavlovna Volkova
Keyword(s):  
Technical Condition ◽  
Reduction Gear ◽  
Vibration Velocity ◽  
Complex Objects ◽  
Measurement Results ◽  
Diagnosis Method ◽  
The Difference ◽  
Velocity Spectra ◽  
Unit Reduction

The article discusses the results of diagnostics-in-place of the reduction gear of the main turbo-gear unit (MTGU) of the Sevmorput LASH carrier. The main characteristics and a brief description of the MTGU design are given. The constructive arrangement of the MTGU project684 OM5 has been illustrated. There are substantiated the methods that can be used for diagnostics-in-place of the turbo-gear units: monitoring vibration levels on bearing housings and comparing them with the results of the previous measurement, comparing the third-octave vibration velocity spectra in the frequency band up to 500 Hz between the power flows of the sides and with the norms of the Russian Maritime Register of Shipping, monitoring the temperature of the bearing assemblies of the gearbox, etc. Choosing the in-situ diagnosis method for the MTGU is determined by the specific features of its design. The diagnostics results are provided. Vibration control was carried out twice: in 1995, on sea trials, and in 2006, during a ship’s voyage to the port of Dudinka under normal running conditions. It was noted that the difference in vibration levels is insignificant; the scatter of values in 2006 appears smaller than in 1995. Changes in the values of temperatures and vibration levels of bearing assemblies during measurement in 2006 were caused by different power modes, compared to measurement made in 1995. The MTGU project 684 OM5 has been approved for further operation after agreeing on the measurement results with the manufacturer of Kirovsky Zavod Production Association. It has been inferred that determining the technical condition of such complex objects by methods of diagnostics-in-place is possible.

scholarly journals Evaluation Method of Allowable Variance for Results of Tribological Measurement on the Basis of Their the Coherence Trends and Of the Covariance Trends

2015 ◽  
Vol 27 (1) ◽  
pp. 73-86
Author(s):  
Marek Zboiński ◽  
Paweł Lindstedt ◽  
Maciej Deliś
Keyword(s):  
Evaluation Method ◽  
Coherence Function ◽  
Technical Condition ◽  
Rolling Bearings ◽  
Tribological Tests

Abstract This article discusses the possibility of assessing the technical condition of rolling bearings based on tribological tests of oil samples. The problem is to define diagnostic levels, especially when has a relatively small number of measurements (3, 4, 5 etc.). Rating variance of measurements can be performed using the dimensionless factor covariance ρ(τ) and the dimensionless coherence function y2(a). The set is compact enough when ρ ()) and γ 2(a) will be close enough to oscillate around the value of 1 [1, 3]. In summary, it is concluded that the thresholds S, 2S, 35 are reliable when ρ()) and y2(a) are greater than 0.7 [6].

scholarly journals Evaluation method of allowable variance for results of tribological measurement on the basis of their the coherence trends and of the covariance trends

2015 ◽  
Vol 36 (1) ◽  
pp. 5-16
Author(s):  
Marek Zboiński ◽  
Paweł Lindstedt ◽  
Maciej Deliś
Keyword(s):  
Evaluation Method ◽  
Coherence Function ◽  
Technical Condition ◽  
Rolling Bearings ◽  
Tribological Tests

Abstract This article discusses the possibility of assessing the technical condition of rolling bearings based on tribological tests of oil samples. The problem is to define diagnostic levels, especially when has a relatively small number of measurements (3, 4, 5 etc.). Rating variance of measurements can be performed using the dimensionless factor covariance ρ(τ) and the dimensionless coherence function γ2(ω). The set is compact enough when ρ (τ) and γ 2(ω) will be close enough to oscillate around the value of 1 [1, 3]. In summary, it is concluded that the thresholds δ, 2δ, 3δ are reliable when ρ (τ) and γ 2(ω) are greater than 0.7 [6].

scholarly journals THERMAL, MECHANICAL, AND TRIBOLOGICAL PROPERTIES OF PTFE COMPOSITE WITH 20% GRAPHITE CONTENT IRRADIATED WITH AN ELECTRON BEAM

Tribologia ◽  
2017 ◽  
pp. 17-20 ◽  
Author(s):  
Adrian BARYLSKI ◽  
Sławomir KAPTACZ ◽  
Władysław SKONECZNY ◽  
Marian KUPKA ◽  
Krzysztof ANIOŁEK
Keyword(s):  
Electron Beam ◽  
Tribological Properties ◽  
Friction Pair ◽  
Degree Of Crystallinity ◽  
Linear Wear ◽  
Initial State ◽  
Tribological Tests ◽  
Mechanical And Tribological Properties ◽  
Operational Life ◽  
Pin On Disc

The paper investigated the effect of irradiation with an electron beam of energy 10MeV in doses of 26-156 kGy on polytetrafluoroethylene with a 20% graphite additive. The tests have shown that changes in thermal properties of the composite (heat of crystallization, melting point and degree of crystallinity) directly affected mechanical properties and contributed to the significant improvement of tribological properties. Tribological tests were performed on a pin-on-disc (T-01) test stand and counter-specimens were made of 1H18N9T steel. The load applied in the friction pair was 1 and 2 MPa (20 and 40 N). A nearly fourfold reduction in linear wear compared to the initial state for a load of 1 MPa has been shown. On the other hand, a more than 20-fold decrease in wear was found during tribological tests when the load was increased to 2 MPa. The most advantageous results were obtained for specimens irradiated with a dose of 104 kGy; irradiation with a higher dose led to degradation of the polymer and caused its wear to increase again. The obtained results hold promise for a significant improvement of the operational life of friction couples which do not require lubrication, used for example in air compressors and engines, and for the possible application of thus modified polymers in nuclear and space industries.

Structural and Chemical Studies of Pathological Fibers in Human Neurofibrillary Degeneration

1985 ◽  
Vol 43 ◽  
pp. 726-729
Author(s):  
K.S. Kosik ◽  
L.K. Duffy ◽  
S. Bakalis ◽  
C. Abraham ◽  
D.J. Selkoe
Keyword(s):  
Monoclonal Antibodies ◽  
Alzheimer Disease ◽  
Human Brain ◽  
Neurofibrillary Tangles ◽  
Morphological Analysis ◽  
High Specificity ◽  
Cytoskeletal Proteins ◽  
Neuritic Plaque ◽  
Protein Chemistry ◽  
Chemical Studies

The major structural lesions of the human brain during aging and in Alzheimer disease (AD) are the neurofibrillary tangles (NFT) and the senile (neuritic) plaque. Although these fibrous alterations have been recognized by light microscopists for almost a century, detailed biochemical and morphological analysis of the lesions has been undertaken only recently. Because the intraneuronal deposits in the NFT and the plaque neurites and the extraneuronal amyloid cores of the plaques have a filamentous ultrastructure, the neuronal cytoskeleton has played a prominent role in most pathogenetic hypotheses.The approach of our laboratory toward elucidating the origin of plaques and tangles in AD has been two-fold: the use of analytical protein chemistry to purify and then characterize the pathological fibers comprising the tangles and plaques, and the use of certain monoclonal antibodies to neuronal cytoskeletal proteins that, despite high specificity, cross-react with NFT and thus implicate epitopes of these proteins as constituents of the tangles.

Characterization of Chemical Impurities in Glutaraldehyde

1975 ◽  
Vol 33 ◽  
pp. 620-621
Author(s):  
B. J. Grenon ◽  
A. J. Tousimis
Keyword(s):  
Glutaric Acid ◽  
Spectroscopic Analysis ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Impurity Component ◽  
Chemical Impurities ◽  
Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

Elemental analysis of human erythrocytes

1989 ◽  
Vol 47 ◽  
pp. 242-243
Author(s):  
S. A. Livesey ◽  
A. A. del Campo ◽  
E. S. Griffey ◽  
D. Ohlmer ◽  
T. Schifani ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Elemental Analysis ◽  
Human Erythrocyte ◽  
Spectroscopic Analysis ◽  
Model System ◽  
Human Erythrocytes ◽  
List Type ◽  
Chemical Fixation ◽  
Ethanol Dehydration ◽  
Lowicryl K4m

The aim of this study is to compare methods of sample preparation for elemental analysis. The model system which is used is the human erythrocyte. Energy dispersive spectroscopic analysis has been previously reported for cryofixed and cryosectioned erythrocytes. Such work represents the reference point for this study. The use of plastic embedded samples for elemental analysis has also been documented. The work which is presented here is based on human erythrocytes which have been either chemically fixed and embedded or cryofixed and subsequently processed by a variety of techniques which culminated in plastic embedded samples.Heparinized and washed erythrocytes were prepared by the following methods for this study :(1). Chemical fixation in 4% paraformaldehyde/0.25% glutaraldehyde/0.2 M sucrose in 0.1 M Na cacodylate, pH 7.3 for 30 min, followed by ethanol dehydration, infiltration and embedding in Lowicryl K4M at -20° C.

Influence of Certain Drugs on the Adhesiveness of Human, Rat, and Rabbit Blood Platelets in Vitro

1965 ◽  
Vol 13 (02) ◽  
pp. 428-438 ◽  
Author(s):  
K Reber ◽  
A Studer
Keyword(s):  
Sodium Citrate ◽  
Blood Platelets ◽  
Drug Application ◽  
Normal Range ◽  
Blood Samples ◽  
Serotonin Antagonist ◽  
Thrombocyte Count ◽  
Particle Count ◽  
Rabbit Blood

SummaryThis is a comparative study of the methods described by H. P. Wright and O’Brien for determining the adhesiveness of thrombocytes. An attempt is made to characterize and statistically correlate both techniques. With the aid of a Coulter Counter for thrombocyte counts, a normal range is presented for human, rat, and rabbit blood. Anticoagulants used are sodium citrate and Heparin.The influence of Cocaine and the Serotonin antagonist Ro 3-0837 was studied on these same substrates, to determine a pharmacological interference with results of either Wright’s test or O’Brien’s. Both drugs are found to induce a statistically significant increase in the “thrombocyte count” as compared to the corresponding controls. These effects are not real but to be attributed to an increase in particle count due to thrombocyte fragmentation as a consequence of drug application. There is no evidence for the claim that these drugs decrease the adhesiveness of thrombocytes.Numerical results of both tests often show a high and statistically significant correlation, especially following the addition of Ro 3-0837. Such is not true of individual blood samples to which no drug has been added. Evidentally, both tests are not specific for the same characteristic of normal blood platelets. But, when Ro 3-0837 is added, the breakdown of unstable platelets is induced; and the corresponding increase in count of thrombocyte fragments is expressed by both tests in the same fashion.

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