scholarly journals Investigation of Fused Alumina Based-Mold Facecoats for DZ22B Directionally Solidified Blades

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 606
Author(s):  
Fei Li ◽  
Hongjun Ni ◽  
Lixiang Yang ◽  
Yi Jiang ◽  
Donghong Wang ◽  
...  
Keyword(s):  
Directional Solidification ◽  
Investment Casting ◽  
Sessile Drop ◽  
Directionally Solidified ◽  
Casting Method ◽  
Metallic Luster ◽  
Interface Reactions ◽  
Sessile Drop Experiment ◽  
Main Factor

The interaction between alloy melt and mold facecoats is the main factor affecting the surface quality of investment casting nickel-based superalloys. An investigation was undertaken to develop suitable refractories as facecoat materials for the directionally solidified blades of DZ22B nickel-based superalloys in order to avoid a sand-burning defect. The wettability and interface reactions between alloy melt and various facecoats were studied by using a sessile drop experiment and the real investment casting method, respectively. The results show that by adding Cr2O3 powder with the amounts of 2 wt.%, 5 wt.% and 10 wt.% in the fused alumina-based facecoats, the wetting angles between the alloy melt and facecoats decreased from 105.40° to 100.37°, 99.96° and 98.11°, respectively, while the sand-burning defect on the casting blade surfaces still formed during the process of directional solidification. However, by adding h-BN powder in the fused alumina-based facecoats, the wetting angles between the alloy melt and facecoats dramatically increased, the sand-burning defect on the casting blade surfaces was effectively inhibited and a metallic luster on the directionally solidified blades could be obviously observed. In this study, the suitable composition of mold facecoats for the investment casting of blades is 2 wt.% h-BN added fused alumina.

Fabrication of ZA Alloy Rods by Continuous Casting with Heated Mold

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1503-1509
Author(s):  
Ma Ying ◽  
Hao Yuan ◽  
Feng Yun Yan ◽  
Hong Jun Liu ◽  
Chang Min Suh
Keyword(s):  
Continuous Casting ◽  
Directional Solidification ◽  
Surface Quality ◽  
Alloy Composition ◽  
Pressure Head ◽  
Outlet Temperature ◽  
Casting Method ◽  
Phase Zone ◽  
Two Phase

The continuous directional solidification technique of 5 kinds of special ZA alloys with eutectic, eutectoid and peritectic transformations under the condition of continuous casting by heated mold was studied. The optimum fitting range of technique factors in each alloy is found. The results show that the operation of guiding ingot is the key of the technique to produce directional solidification ZA alloy line by heated mold in continuous casting method. Outlet temperature, pulling speed, cooling condition, alloy composition and pressure head have direct influences on the surface quality of ingot. There is a balance between heat and force in the two-phase zone of solid and liquid. Only adjusting technique parameters with the balance and keeping a good place of the interface between solid and liquid, can the smooth ZA alloy line be continuously pulled out.

Investigations on Interface Reactions and Wettability between Melt Superalloys and Ceramic Materials

2016 ◽  
Vol 703 ◽  
pp. 132-137 ◽  
Author(s):  
Xiao Yan Chen ◽  
Fei Li ◽  
Jun Wang ◽  
Bao De Sun
Keyword(s):  
Ceramic Material ◽  
Sessile Drop ◽  
Active Element ◽  
Interface Reaction ◽  
Ceramic Materials ◽  
Wetting Angle ◽  
Reactive System ◽  
Reaction Products ◽  
Interface Reactions ◽  
Sessile Drop Experiment

Interface reactions and wettability between melt superalloys and ceramic mould materials were investigated by using a sessile drop experiment. The wetting angle of the melt alloy on the ceramic material was calculated and the microstructure of the alloy interface was investigated by metalloscope as well as SEM. It was found that active element C in the alloy is an important factor that influences the interface reactions and the wettability. Alloys with C content lower than 0.07wt.% were almost stable on the ceramic material and no interface reaction products were found. However, alloys with C content higher than 0.16wt.% reacted with the ceramic materials. Purple reaction products were found on the alloy surface and sand adhesions were observed at the alloy-ceramic interface. In the non-reactive system, the wetting angle is in the range of 135o-150o. In the reactive system, the wetting angle is lower than 120o.

The effect of back-melting on the continuity of crystallographic orientation and composition in HgZnTe

1992 ◽  
Vol 50 (2) ◽  
pp. 1696-1697
Author(s):  
H.J. Zuo ◽  
M.W. Price ◽  
R.D. Griffin ◽  
R.A. Andrews ◽  
G.M. Janowski
Keyword(s):  
Directional Solidification ◽  
Space Shuttle ◽  
Solidification Process ◽  
Space Experiment ◽  
Infrared Detection ◽  
Directionally Solidified ◽  
Crystallographic Defects ◽  
Semiconducting Alloys ◽  
Uniform Composition ◽  
Growth Experiments

The II-VI semiconducting alloys, such as mercury zinc telluride (MZT), have become the materials of choice for numerous infrared detection applications. However, compositional inhomogeneities and crystallographic imperfections adversly affect the performance of MZT infrared detectors. One source of imperfections in MZT is gravity-induced convection during directional solidification. Crystal growth experiments conducted in space should minimize gravity-induced convection and thereby the density of related crystallographic defects. The limited amount of time available during Space Shuttle experiments and the need for a sample of uniform composition requires the elimination of the initial composition transient which occurs in directionally solidified alloys. One method of eluding this initial transient involves directionally solidifying a portion of the sample and then quenching the remainder prior to the space experiment. During the space experiment, the MZT sample is back-melted to exactly the point at which directional solidification was stopped on earth. The directional solidification process then continues.

Qualitŕ della vita e invecchiamento della popolazione. Materiali per un'ipotesi alternativa alla questione pensionistica

2009 ◽  
pp. 67-91
Author(s):  
Adele Bianco
Keyword(s):  
Quality Of Life ◽  
Life Quality ◽  
Main Idea ◽  
Living Condition ◽  
Climate And Environmental Change ◽  
Safety And Health ◽  
Positive Ageing ◽  
The Impact ◽  
Main Factor

The topic of this article is quality of life and ageing process specially focused on today young generations and their coming retirement situation. The main idea is that quality of life is increasing, that means longer, safer and better living condition; consequently positive ageing processes mean also reforming retirement sector. The hypothesis carried out in this paper is an alternative one. Despite of the positive trends, we describe how three main factor of nowadays life are, on the contrary, turning into worse condition the future of young generations and their coming life situation. Firstly we consider the socio-economic aspects, the impact on health and the implications connected with precarious work. Secondly we consider pollution and its effects on health, life quality and life expectation. Thirdly we pay attention about climate and environmental change and their effect on health, life quality and expectation. In conclusion, the retirement future of today young generations may be very different (worse) than expected. The paper in based on WHO, IPCC and European Agency for Safety and Health at Work data and reports.Key words: Young generations; Coming quality of life; Population ageing and future of retirement question.Parole chiave: Giovani generazioni; Qualitŕ della vita; Invecchiamento della popolazione e pensioni.

THE ROLE OF COW PROCESSING IN IMPROVEMENT MILK QUALITY

2018 ◽  
Vol 1 (1) ◽  
pp. 59-63
Author(s):  
G. A. Larionov ◽  
◽  
O. Yu. Сhecheneshkina ◽  
E. S. Yatrusheva ◽  
N. I. Yendierov ◽  
...  
Keyword(s):  
Somatic Cell Count ◽  
Somatic Cells ◽  
Cow Milk ◽  
Microbiological Contamination ◽  
High Quality ◽  
Quality Of Milk ◽  
Correct Understanding ◽  
Main Factor

The main factor of determining the level of sanitary and hygienic indicators of the quality of milk produced is the hygiene of milking cows. The study of the role of hygiene of milking is of great importance for a correct understanding of the ways of solving the problem of obtaining high quality milk. Special attention of scientists and practitioners in recent years are focused on the development and implementation of highly effective detergents and disinfectants in the production of milk of cows. Many researchers and practitioners have directed their work to developing measures to prevent the entry of pathogenic microflora into milk during and after milking cows. In spite of many researches carried out, aimed at controlling the number of somatic cells in milk with the use of different products based on lactic acid, chlorhexidine and iodine, the problem of high quality milk production remains unresolved. In our work results of researches on the use of probiotic means for treatment of udders of cows are given. Processing the udder of cows with probiotic means before milking by Skin Cleaner, after milking by PIP Cow Teat Cleaner reduced the amount of somatic cells in cow milk 12,8-84,0%. The use of probiotic means Biomastim lowed somatic cell count of 18,4-51,9%. Microbiological contamination of milk using probiotic means for processing the udder before milking Skin Cleaner, after milking PIP Cow Teat Cleaner decreased 4,9- 70,4 times. The application of probiotic means Biomastim after milking on the teats led to the decrease in milk of cows QMAFAnM 5,0-6,6 times.

scholarly journals The modern law-making process: structure and main problems

2021 ◽  
Vol 39 (69) ◽  
pp. 605-614
Author(s):  
Mikhail B. Rumyantsev ◽  
Vladislav Yu. Turanin ◽  
Sergey Yu. Sumenkov ◽  
Marina G. Smirnova ◽  
Esita E. Ganaeva
Keyword(s):  
Standard Setting ◽  
The State ◽  
Dialectical Method ◽  
Legal Norms ◽  
State And Society ◽  
Process Structure ◽  
Theoretical Foundations ◽  
Law Making ◽  
Main Factor

Through the dialectical method the objective of the article was to analyze the process of the elaboration of modern laws, considering their structure and main problems. There is a major structure and problems inherent in the modern law-making process described in the article. The structure of law-making comprises four parts: 1. Cognitive-analytical part; 2. Theoretical foundations of the legal norms and acts they dictate; 3. Validation of legal act or norm; 4. Monitoring of relevant rules and legal acts. The main legislative task is to draft legal norms that stimulate the active development of all parts of the State and society through a deep perception of all related processes, including those involving standard-setting. It is concluded that the main factor affecting the quality of legislation is the lack of a uniform legislative basis for the issuance of legal acts. There seems to be a real need to develop a uniform legislative act on the law-making process. The Code containing general and specific parts of each law must be developed.

scholarly journals THE CONTACT ANGLE CONTROL OF THE SOLDER FOR IMPROVING THE SOLDERING QUALITY

2021 ◽  
pp. 161-166
Author(s):  
Чуйко М.М. ◽  
Завальський В.
Keyword(s):  
Contact Angle ◽  
Sessile Drop ◽  
Electrical Contact ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Soldering Process ◽  
Basic Parameters ◽  
The Right

High quality of the soldering process can be achieved with the right choice of the necessary soldering materials. Since wetting determines the further nature of the connection between the solder and the main soldering material, the contact angle  measurement  is the basis for quality control of soldering materials, provided that the basic requirements of the technological process. The determination of the contact angle value is carried out by the indirect method of the sessile drop, by measuring the basic parameters of the drop using infrared transducer. A smaller value of the contact angle corresponds to a better interaction of materials, and hence a better electrical contact

scholarly journals Cytomegalovirus infection and reproductive health of women

2016 ◽  
Vol 65 (4) ◽  
pp. 24-33 ◽  
Author(s):  
Natalia R. Belyaeva
Keyword(s):  
Risk Factors ◽  
Health Care ◽  
Reproductive Health ◽  
Cytomegalovirus Infection ◽  
Near Miss ◽  
Pregnancy And Childbirth ◽  
Quality Of Medical Care ◽  
Pregnancy And Birth ◽  
Main Factor

The article presents material about critical states in obstetric and gynecologic practice (“near miss”), obtained on the basis of their own research, as well as the data of domestic and foreign authors. It is shown that the main factor determining the outcome of the pregnancy and birth, is the quality of medical care provided to the woman. The characteristics of “near miss”, indicated the risk factors for its occurrence. A measure of the health care until serious complications of pregnancy and childbirth, as well as possible ways to reduce the frequency of their development.

scholarly journals 'Sensory analysis of specialty coffee from different environmental conditions in the region of Matas de Minas, Minas Gerais, Brazil

Revista CERES ◽  
2016 ◽  
Vol 63 (4) ◽  
pp. 436-443 ◽  
Author(s):  
Alice de Souza Silveira ◽  
Aracy Camilla Tardin Pinheiro ◽  
Williams Pinto Marques Ferreira ◽  
Laércio Junio da Silva ◽  
José Luis dos Santos Rufino ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Sensory Analysis ◽  
Sensory Quality ◽  
Sensory Attributes ◽  
Fruit Color ◽  
Tukey Test ◽  
Specialty Coffee ◽  
Final Score ◽  
Main Factor

ABSTRACT Specialty coffees can be differentiated in various ways, including the environmental conditions in which they are produced and the sensory composition of the drink. This study aimed to evaluate the effect of altitude, slope exposure and fruit color on the sensory attributes of cafes of the region of Matas de Minas. Sampling points were georeferenced in four altitude ranges (< 700 m; 700 ≤ x ≤ 825 m, 825 < x < 950 m and ≥ 950 m) of the coffee crop; two fruit colors of var. Catuaí (yellow and red); and two slope exposures (North-facing and South-facing). Coffee fruit at the cherry stage were processed and submitted to sensory analysis. The sensory attributes evaluated were overall perception, clean cup, balance, aftertaste, sweetness, acidity, body and flavor, which made up the final score. The scores were examined by ANOVA and means were compared by the Tukey test (p ≤ 0.05). From the sensory standpoint, coffee fruits of both colors are similar, as well as the coffees from both slope exposures when these factors were analyzed separately. However, at higher altitudes, Yellow Catuaí produces coffees with better sensory quality. Similarly, coffees from North-facing slopes, at higher altitudes produce better quality cup. The altitude is the main factor that interferes with coffee quality in the area. All factors together contribute to the final quality of the beverage produced in the region of Matas de Minas.

scholarly journals Combined Effect of Dipping in Oxalic or in Citric Acid and Low O2 Modified Atmosphere, to Preserve the Quality of Fresh-Cut Lettuce during Storage

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 988
Author(s):  
Bernardo Pace ◽  
Imperatrice Capotorto ◽  
Michela Palumbo ◽  
Sergio Pelosi ◽  
Maria Cefola
Keyword(s):  
Citric Acid ◽  
Respiration Rate ◽  
Modified Atmosphere Packaging ◽  
Packaging Material ◽  
Combined Effect ◽  
Modified Atmosphere ◽  
Iceberg Lettuce ◽  
Fresh Cut ◽  
Main Factor

Leaf edge browning is the main factor affecting fresh-cut lettuce marketability. Dipping in organic acids as well as the low O2 modified atmosphere packaging (MAP), can be used as anti-browning technologies. In the present research paper, the proper oxalic acid (OA) concentration, able to reduce respiration rate of fresh-cut iceberg lettuce, and the suitable packaging materials aimed to maintaining a low O2 during storage, were selected. Moreover, the combined effect of dipping (in OA or in citric acid) and packaging in low O2 was investigated during the storage of fresh-cut iceberg lettuce for 14 days. Results showed a significant effect of 5 mM OA on respiration rate delay. In addition, polypropylene/polyamide (PP/PA) was select as the most suitable packaging material to be used in low O2 MAP. Combining OA dipping with low O2 MAP using PP/PA as material, resulted able to reduce leaf edge browning, respiration rate, weight loss and electrolyte leakage, preserving the visual quality of fresh-cut lettuce until 8 days at 8 °C.

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