MATERIALS SCIENCE RESEARCH DEFECT OCCURRENCE AND RUPTURE OF THE GAS PUMPING UNIT AXIAL COMPRESSOR BLADE

2020 ◽  
pp. 24-28
Author(s):  
R. M. Ramazanov ◽  
M. I. Ramazanov ◽  
T. A. Sapargaliev ◽  
A. V. Kim
Keyword(s):  
Materials Science ◽  
Defect Formation ◽  
Operating Time ◽  
Axial Compressor ◽  
Science Research ◽  
Compressor Blade ◽  
Fractographic Analysis ◽  
Destructive Testing ◽  
Working Blades ◽  
Gas Pumping Unit

The article discusses the results of the study of the causes of destruction of the axial compressor blade and the causes of the defect of the working blade 10 stage GTU GPA type GTK-10-4 station No. 18 of the compressor station “Dzhangala”. The blade is made of X20Cr13 steel (AISI 420). The blades have an operating time of 23 284 hours after the last repair. Chemical analysis, fractographic analysis, and hardness measurements were performed. The probable cause of defect formation and destruction of the blade is established. The measured hardness values comply with the standard. А study of the chemical composition of metal blades is not revealed a deviation in the content of the main alloying elements. The results of fractographic analysis showed that the destruction caused the presence of a subsurface defect. The defect is an oxidizing shell of about 9×4 mm in size with propagation in operation to the outer surface. In operation, as a result of corrosion, static and dynamic stresses, a crack was formed in the area of the source with exit to the surface along the input edge of the blade. Non-destructive testing was performed on the remaining blades. No defects detected. On the basis of which it was decided to continue the operation of the working blades of the GTK-10-4 turbine, subject to periodic monitoring.

scholarly journals Solvent-Controlled Self-Assembled Oligopyrrolic Receptor

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1771
Author(s):  
Fei Wang ◽  
Kejiang Liang ◽  
Mads Christian Larsen ◽  
Steffen Bähring ◽  
Masatoshi Ishida ◽  
...  
Keyword(s):  
Materials Science ◽  
Science Research ◽  
Polymeric Chain ◽  
Supramolecular System ◽  
Receptor System ◽  
One Dimensional ◽  
X Ray ◽  
Host Guest Complex ◽  
Colorimetric Response ◽  
Strong Acids

We report a fully organic pyridine-tetrapyrrolic U-shaped acyclic receptor 10, which prefers a supramolecular pseudo-macrocyclic dimeric structure (10)2 in a less polar, non-coordinating solvent (e.g., CHCl3). Conversely, when it is crystalized from a polar, coordinating solvent (e.g., N,N-dimethylformamide, DMF), it exhibited an infinite supramolecular one-dimensional (1D) “zig-zag” polymeric chain, as inferred from the single-crystal X-ray structures. This supramolecular system acts as a potential receptor for strong acids, e.g., p-toluenesulfonic acid (PTSA), methane sulfonic acid (MSA), H2SO4, HNO3, and HCl, with a prominent colorimetric response from pale yellow to deep red. The receptor can easily be recovered from the organic solution of the host–guest complex by simple aqueous washing. It was observed that relatively stronger acids with pKa < −1.92 in water were able to interact with the receptor, as inferred from 1H NMR titration in tetrahydrofuran-d8 (THF-d8) and ultraviolet–visible (UV–vis) spectroscopic titrations in anhydrous THF at 298 K. Therefore, this new dynamic supramolecular receptor system may have potentiality in materials science research.

High-Impact Practices in Materials Science Education: Student Research Internships Leading to Pedagogical Innovation in STEM Laboratory Learning Activities

MRS Advances ◽  
2017 ◽  
Vol 2 (31-32) ◽  
pp. 1667-1672 ◽  
Author(s):  
Lon A. Porter
Keyword(s):  
Computer Aided Design ◽  
Materials Science ◽  
Undergraduate Research ◽  
Science Research ◽  
High Impact ◽  
Digital Design ◽  
Education Student ◽  
Research Experience ◽  
Student Research ◽  
Pedagogical Innovation

ABSTRACTTraditional lecture-centered approaches alone are inadequate for preparing students for the challenges of creative problem solving in the STEM disciplines. As an alternative, learnercentered and other high-impact pedagogies are gaining prominence. The Wabash College 3D Printing and Fabrication Center (3D-PFC) supports several initiatives on campus, but one of the most successful is a computer-aided design (CAD) and fabrication-based undergraduate research internship program. The first cohort of four students participated in an eight-week program during the summer of 2015. A second group of the four students was successfully recruited to participate the following summer. This intensive materials science research experience challenged students to employ digital design and fabrication in the design, testing, and construction of inexpensive scientific instrumentation for use in introductory STEM courses at Wabash College. The student research interns ultimately produced a variety of successful new designs that could be produced for less than $25 per device and successfully detect analytes of interest down to concentrations in the parts per million (ppm) range. These student-produced instruments have enabled innovations in the way introductory instrumental analysis is taught on campus. Beyond summer work, the 3D-PFC staffed student interns during the academic year, where they collaborated on various cross-disciplinary projects with students and faculty from departments such as mathematics, physics, biology, rhetoric, history, classics, and English. Thus far, the student work has led to three campus presentations, four presentations at national professional conferences, and three peer-reviewed publications. The following report highlights initial progress as well as preliminary assessment findings.

Symmetry-general ab initio computation of physical properties using quantum software integrated with crystal structure databases: results and perspectives

2002 ◽  
Vol 58 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Yvon Le Page ◽  
Paul W. Saxe ◽  
John R. Rodgers
Keyword(s):  
Crystal Structure ◽  
Physical Properties ◽  
Ab Initio ◽  
Materials Science ◽  
Science Research ◽  
Elastic Tensor ◽  
Pure Phase ◽  
Simulation And Experiment ◽  
Structure Databases ◽  
Using Data

The timely integration of crystal structure databases, such as CRYSTMET, ICSD etc., with quantum software, like VASP, OresteS, ElectrA etc., allows ab initio cell and structure optimization on existing pure-phase compounds to be performed seamlessly with just a few mouse clicks. Application to the optimization of rough structure models, and possibly new atomic arrangements, is detailed. The ability to reproduce observed cell data can lead to an assessment of the intrinsic plausibility of a structure model, even without a competing model. The accuracy of optimized atom positions is analogous to that from routine powder studies. Recently, the ab initio symmetry-general least-squares extraction of the coefficients of the elastic tensor for pure-phase materials using data from corresponding entries in crystal structure databases was automated. A selection of highly encouraging results is presented, stressing the complementarity of simulation and experiment. Additional physical properties also appear to be computable using existing quantum software under the guidance of an automation scheme designed following the above automation for the elastic tensor. This possibility creates the exciting perspective of mining crystal structure databases for new materials with combinations of physical properties that were never measured before. Crystal structure databases can accordingly be expected to become the cornerstone of materials science research within a very few years, adding immense practical value to the archived structure data.

scholarly journals Reviewer acknowledgements for Journal of Materials Science Research, Vol. 5, No. 4

2016 ◽  
Vol 5 (4) ◽  
pp. 96
Author(s):  
Lily Green
Keyword(s):  
Materials Science ◽  
Science Research

<div>Reviewer acknowledgements for Journal of Materials Science Research, Vol. 5, No. 4, 2016</div>

From Concept to Commerce: The Challenge of Technology Transfer in Materials

MRS Bulletin ◽  
1990 ◽  
Vol 15 (8) ◽  
pp. 49-53 ◽  
Author(s):  
Larry L. Hench
Keyword(s):  
Technology Transfer ◽  
Materials Science ◽  
Science Research ◽  
Private Industry ◽  
Commercial Development ◽  
Materials Development ◽  
University Policy ◽  
Transfer Case ◽  
Effective Form ◽  
The Government

Many millions of dollars are invested annually in materials science research and development in U.S. universities. Both the universities and the sponsors, either government or private industry, have enormous incentives for the R&D efforts to become commercial. For private industry a successful development means new or improved products or processes and ultimately more profits. For the government, successful materials development can lead to improved hardware or operations efficiency and lower costs. For a university the payoff can be more than economic.Ideally, successful commercial development leads to royalties paid to the universities in the form of the most precious of assets — Unrestricted or flexible income. Students and faculty can benefit from the additional income, both privately, depending on university policy, and through their departments. However, benefits can also accrue in the form of experience and knowledge gained while participating in the technology transfer process from university to corporation. Students who take part in such efforts gain invaluable experience in preparing and defending patent applications, designing and developing prototypes, and they are exposed to economic and legal issues that are seldom taught in the classroom. They become more valuable graduates. Taking part in a technology transfer case history is a far more effective form of learning than reading about it.These benefits to a university are offset by a number of potentially negative factors. The space, time, personnel, equipment, and deadline pressures involved in commercialization are often beyond the capabilities of a university program. However, these limitations may not be realized until the effort has begun, and it is costly to stop in midstream, as is discussed below.

scholarly journals Observations of Wake-Induced Turbulent Spots on an Axial Compressor Blade

1993 ◽  
Author(s):  
G. J. Walker ◽  
W. J. Solomon ◽  
J. P. Gostelow
Keyword(s):  
Surface Film ◽  
Axial Compressor ◽  
Adverse Pressure Gradient ◽  
Shear Layers ◽  
Compressor Blade ◽  
Ensemble Average ◽  
Transitional Flow ◽  
Instability Wave ◽  
Random Disturbance ◽  
Turbulent Spots

Measurements of transitional flow in regions of strong adverse pressure gradient on an axial compressor stator are reported. The range of observations covers separating laminar flow at transition onset, and reattachment of intermittently turbulent periodically separated shear layers. Transition was characterised by the regular appearance of turbulent spots in association with the rotor blade wake disturbances. However, the initial breakdown did not coincide with the wake passage as has usually been observed by other workers. The spots rather evolved from the growth of instability wave packets which lagged the wake passage. Data presented from the compressor blade measurements include: mean and ensemble-average velocities and associated integral parameters; distributions of total, periodic and random disturbance components; typical individual velocity fluctuation records; contours of ensemble-average random disturbance level; and boundary layer intermittency distributions. Measurements of turbulent intermittency showed a significant fall in this quantity near the wall in the reattaching flow. This has significant implications for the interpretation of transition data from surface film gage observations.

scholarly journals HIGH RISE FRAME BUILDING CONSTRUCTION WITH REGARD TO DEFECTS IN MONOLITHIC BASE SLAB

2020 ◽  
Vol 22 (5) ◽  
pp. 160-172
Author(s):  
S. V. Yushchube ◽  
I. I. Podshivalov ◽  
G. I. Tayukin
Keyword(s):  
Defect Formation ◽  
Strength Properties ◽  
Building Construction ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
High Rise ◽  
Frame Building ◽  
Concrete Layer ◽  
Non Destructive

The paper analyzes the influence of defects detected in a monolithic base slab on the possibility of its further application in the construction of a 25-storey high-rise frame building. Non destructive testing and vertical core sampling techniques are used for the detailed analysis of the monolithic base slab. It is found that irregularities in the procedure during winter concreting of the base slab decreases the strength properties of concrete and provides the defect formation in the slab structure, namely delamination of the lower protective concrete layer and uncovering of working reinforcement. For the safe use of the 25-storey high-rise building, the base slab is proposed to be strengthened by adding in-situ reinforced concrete layer 100 cm thick.

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