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Number of results: 8
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Abstract

The microstructure evolution of boron-bearing high speed steel roll materials after casting and tempering was investigated. The results indicate that as-cast boron-bearing high speed steel consists of martensitic matrix, retained austenite and different borocarbides. The as-cast alloy has a hardness above 64 HRC, and the borocarbides distribute along the grain boundaries. After RE-Mg-Ti compound modification treatment, obvious necking and broken network appear in the grain boundaries. The hardness of boron-bearing high speed steel roll materials reduces gradually with the increase of tempering temperature. Under the same conditions, the toughness of the modified roll material is higher than that of the unmodified roll material. Wear tests show that the wear resistance of boron-bearing high-speed steel modified by RE-Mg-Ti compound modification treatment is better.
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Authors and Affiliations

Cheng Xiaole
1
Hou Jianqiang
2
Fu Hanguang
1

  1. School of Mechanical and Electrical Engineering, Xi’an Polytechnic University, Xi’an 710048, Shaanxi province, P. R. China
  2. MCC Jingcheng Engineering Technology Co., Ltd., Beijing 100176, P.R. China
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Abstract

The extremely rare localization of an intramuscular hemangioma (IMH) into the anterior scalene muscle was the motive for the present case report, aiming to highlight major, atypical characteristics. An 11-month-old boy with free medical history presented with a painless and progressively growing lesion 4.5 × 4 cm in diameter, located in the left supraclavicular region over the last 4 months. During physical examination, the presence of a painless, non-pulsating, non-adhesive to the overlying skin lesion was documented. Color Doppler flow ultrasonographic examination demonstrated the increased blood supply to the aforementioned lesion. Thus, we planned an elective surgical excision of the lesion in healthy limits. The postoperative course was uneventful, and the patient was discharged on the second postoperative day in good general condition. Histopathologic examination revealed the presence of hemangioma surrounded by connective tissue bundles and striated muscle fibers. IMHs do not follow the general rule of regression, beyond the age of 6–12 months, with no trend to increase over time. Accurate preoperative diagnosis is challenging. Color Doppler flow ultrasonographic examination is the imaging modality of choice during the preoperative assessment. Surgical excision of the IMH in healthy limits is the most appropriate treatment option.
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Authors and Affiliations

Ioannis Patoulias
1
Ioanna Gkalonaki
1
ORCID: ORCID
Magdalini Mitroudi
1
Thomas Feidantsis
1
Constantine Theocharidis
2
Dimitrios Patoulias
3

  1. First Department of Pediatric Surgery, Aristotle University of Thessaloniki, General Hospital “G. Gennimatas”, Greece
  2. Department of Pathology, General Hospital “G. Gennimatas”, Thessaloniki, Greece
  3. Second Propedeutic Department of Internal Medicine, Aristotle University of Thessaloniki, General Hospital “Hippokration”, Greece
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Abstract

The purpose of the presented research is to analyse possible methods of thickening of the Microcystis aeruginosa (Kützing) Kützing cyanobacteria using the obtained concentrate as a biomass for the production of energy carriers and bio-logically valuable substances. Method of cyanobacteria thickening under the action of electric current and in the electric field, as well as the method of coagulation–flocculation and gravity thickening, was experimentally investigated in lab-scale conditions. Electrical methods didn't show positive results for the Microcystis aeruginosa thickening, despite the re-ports of their potential efficiency in a number of previous studies. The high efficiency of the method of coagulation–flocculation and gravity thickening of Microcystis aeruginosa suspensions was obtained. The optimum concentrations of industrial polymeric coagulants and flocculants for the thickening of Microcystis aeruginosa suspensions were defined in the range of about 10 ppm for the coagulants and about 1 ppm for the flocculants. Negative effect of the previous cavitational treatment of the diluted suspensions of Microcystis aeruginosa on the effectiveness of the coagulation–flocculation and gravitational thickening was confirmed experimentally. Hydrodynamic cavitation should be recommended to use after the thickening as the next step of processing of concentrated suspensions of Microcystis aeruginosa to achieve maximum extraction of energy carriers and biologically valuable substances.

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Authors and Affiliations

Myroslav Malovanyy
Volodymyr Zhuk
Volodymyr Nykyforov
Igor Bordun
Iurii Balandiukh
Galyna Leskiv
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Abstract

The results of investigations of sand shooting into the core box are presented in the hereby paper. The investigations concern the formation of the diphase sand-air flux, its motion, flowing and compaction in the cavity during the core forming. Conditions deciding on the course of individual phases of the process are discussed with taking into consideration the influence of such factors as: the shot pressure, shooting hole diameter, number and distribution of deaerating vents in experimental core boxes (of a single cavity and of multi cavities) on the core sand compaction state. Investigations were performed by means of the modernised experimental shooting machine SR-3D, of the shooting chamber volume of 3.3 dm3, connected with the system of pneumatic supply ensuring the stable pressure supply of values: 0.4 MPa, 0.5 MPa and 0.6 MPa. Two diameters of the shooting hole, equal 10 mm and 20 mm, were applied for filling three experimental core boxes differing in dimensions of cavities and in number and distribution of deaerating vents. The filling process of core boxes was recorded by means of the digital camera PHANTOM V210 with the filming rate of 3000 pictures in second. Simultaneously, during the shot, other values allowing to determine the intensity of the core sand outflow from the shooting chamber to the core box, were tested. The presented in this publication results constitute the important element of the experimental verification of the blowing process simulation calculations which will be performed.
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Authors and Affiliations

R. Dańko
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Abstract

We present some university rankings, the differences between them and the role they can play in shaping the higher education landscape. We analyse the position of Polish universities in various rankings and suggest why the Polish economy makes little use of the output of Polish researchers.
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Authors and Affiliations

Leszek Pacholski
1

  1. Uniwersytet Wrocławski, Instytut Informatyki

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