scholarly journals METHOD FOR ASSESSING SURFACE QUALITY OF COPPER CATHODES

2019 ◽  
Vol 62 (2) ◽  
pp. 53-58
Author(s):  
Elena V. Shulga ◽  
Aleksandr I. Yurev ◽  
Mikhail I. Bazanov
Keyword(s):  
Surface Quality ◽  
Quantitative Estimation ◽  
Copper Production ◽  
Special Technique ◽  
Vertical Strip ◽  
Current Production ◽  
Electrolysis Bath ◽  
Polar Division ◽  
First Time

In order to stabilize spiral elongation number at the required level (in accordance with the requirements of the European standard EN 12893 not less than 400 mm) the assessment of its distribution on the cathode sheet was carried out. The experimentally obtained results, processed using methods of mathematical statistics, showed significant discrepancies between the values of spiral elongation in the central and other parts of the cathode (upper, lower, side), which indicates an uneven distribution of the spiral elongation number along the cathode sheet. It was found that in order to form a representative analytical sample under cathode copper production of the Polar Division of MMC «Norilsk Nickel», the testing of cathodes should be performed using methods that include all areas of the cathode sheet, for example, cutting of a vertical strip from each cathode which has got in a representative sample, including edges and hanging ears. To determine the dependence of the spiral elongation number on the surface quality of copper cathodes, developed a special technique, based on the detection of the most frequently encountered defects in the surface of the cathode sheet, which assigned a certain numerical value in accordance with the ranking results. The proposed scoring system for the quality of cathodes in appearance allowed us to establish for the first time that stabilization of the spiral elongation number at a level of at least 400 mm is possible if the defectiveness of the cathode surface does not exceed 17 points per one electrolysis bath. The method has found practical application for preliminary quantitative estimation of the most widespread superficial defects of copper cathodes in the conditions of current production.

Method for assessing the surface quality of copper cathodes

1970 ◽  
Author(s):  
E.V. Shulga ◽  
A.I. Yurev ◽  
M.I. Bazanov
Keyword(s):  
Surface Quality ◽  
Cathode Surface ◽  
Special Technique ◽  
Practical Application ◽  
European Standard ◽  
Cathode Copper ◽  
Current Production ◽  
Polar Division ◽  
First Time

One of the criteria for the quality of high-purity copper, which makes it possible to evaluate its mechanical properties and, accordingly, its suitability for use by consumers, is the spiral elongation number which, in accordance with the requirements of the European Standard EN 12893, must be at least 400 mm.  In order to stabilize spiral elongation number at the required level, an estimate is made of its distribution along the cathode web.  Experimentally obtained results, processed using mathematical statistics methods, showed significant discrepancies between the spiral elongation values in the central and other parts of the cathode (upper, lower, side), which indicates an uneven distribution of the spiral elongation number along the cathode web.  It was found that in order to form a representative analytical sample under cathode copper cathode production of the Polar Division of MMC «Norilsk Nickel», cathode testing should be performed using methods that include all areas of the cathode web, including edges and ears. To determine the dependence of the spiral elongation number on the surface quality of copper cathodes, a special technique has been developed, based on the detection of the most frequently encountered defects in the surface of the cathode web, which is assigned a certain numerical value in accordance with the ranking results.  The proposed scoring system for the quality of cathodes in appearance allowed us to establish for the first time that stabilization of the spiral elongation number at a level of at least 400 mm is possible if the defectiveness of the cathode surface does not exceed 17 points per bath.  The technique has found practical application for assessing the surface quality of copper cathodes under current production conditions. 

scholarly journals Spanish journalists and the loss of news quality: Professional judgements

Comunicar ◽  
2015 ◽  
Vol 23 (45) ◽  
pp. 143-150 ◽  
Author(s):  
Josep-Lluis Gómez-Mompart ◽  
Juan-Francisco Gutiérrez-Lozano ◽  
Dolors Palau-Sampio
Keyword(s):  
Private Investment ◽  
Point Of View ◽  
Academic Context ◽  
Media Companies ◽  
Political Independence ◽  
Current Production ◽  
Precarious Labor ◽  
And Behavior ◽  
First Time

This article discusses the opinions of Spanish journalists on the quality of their professional work and how it is being affected by the current economic, technological, commercial and professional context. The results are based on a questionnaire in which 363 Spanish journalists participated, all with a minimum of three years experience. Their answers reflect on the structure and behavior of media companies and current production of news. The article specifically focuses on exposing the journalists’ opinions on the quality of their work. The results show that 81% of the participants state that standards of quality in journalistic production has deteriorated. This deterioration is believed to be connected to the effect of the economic struggles in the sector. They suggested that the principle motives of this decline lie in the lack of economic and political independence, a lack of private investment and in the problems caused by technological changes. These situations all fall into the context of a precarious labor market within the sector. The article also links the results with academic works that have analyzed the quality of journalism over recent years. It offers, for the first time in the Spanish academic context, the Spanish journalists’ own point of view on these issues. Este artículo expone los resultados de una investigación acerca del modo en el que los periodistas españoles en ejercicio enjuician la calidad periodística y cómo esta se ve afectada por el contexto económico, tecnológico, empresarial, laboral y profesional actual del periodismo. El texto recoge los resultados de una encuesta en la que participan 363 periodistas españoles con al menos tres años de experiencia en medios de comunicación. Sus respuestas aluden, entre otros aspectos, a las reflexiones acerca de la estructura y el comportamiento de las empresas informativas, así como las características predominantes de la información periodística en la actualidad. En particular, el artículo se centra en exponer las consideraciones de los periodistas acerca del cuidado o esmero de su labor profesional. Entre los principales resultados destaca que el 81% de los encuestados reconoce un empeoramiento de los patrones de calidad del producto periodístico, que ligan a la crisis del sector. Entre las posibles causas se mencionan la falta de independencia económica y política de los medios, la falta de inversión empresarial y los problemas derivados de los cambios tecnológicos, todo ello en un contexto de precarización del mercado laboral periodístico. El artículo vincula estos resultados a otros estudios internacionales que han abordado, de manera sistemática, la calidad periodística, aportando por primera vez en el contexto académico español una perspectiva de la cuestión a partir de los propios profesionales.

scholarly journals Выглаживание поверхности антимонида галлия

2020 ◽  
Vol 46 (23) ◽  
pp. 48
Author(s):  
Р.В. Левин ◽  
И.В. Федоров ◽  
А.С. Власов ◽  
П.Н. Брунков ◽  
Б.В. Пушный
Keyword(s):  
Surface Quality ◽  
Annealing Time ◽  
Smooth Surface ◽  
Annealing Conditions ◽  
First Time

For the first time, the results of a study of the conditions for obtaining an atomically smooth surface of GaSb substrates are presented. It is shown experimentally that it is possible to improve the surface quality of the samples by changing the annealing conditions. The lowest obtained roughness of 1.27 nm was obtained at an annealing time of 16 minutes at a temperature of 650°C in the flow of TMSb and H2.

Large-Area Homoepitaxial Growth of Low-Doped Thick Epilayers for Power Devices with VBR > 4 kV

2009 ◽  
Vol 615-617 ◽  
pp. 77-80 ◽  
Author(s):  
Bernd Thomas ◽  
Christian Hecht ◽  
Birgit Kallinger
Keyword(s):  
Layer Thickness ◽  
Surface Quality ◽  
Doping Concentration ◽  
Epitaxial Layers ◽  
Power Devices ◽  
Large Area ◽  
Homoepitaxial Growth ◽  
Different Types ◽  
First Time

In this paper we present results on the growth of low-doped thick epitaxial layers on 4° off-oriented 4H-SiC using a commercially available hot-wall multi-wafer CVD system. For the first time we show results of a low-doped full-loaded 73” run on 4° off-oriented substrates with a layer thickness of more than 70 µm. The target doping concentration of 1.2×1015 cm-3 is suitable for blocking voltages > 6 kV. Results on doping, thickness and wafer-to-wafer homogeneities are shown. The surface quality of the grown layers was characterized by AFM. The density of different types of dislocations was determined by Defect Selective Etching.

scholarly journals Investigation on Feasibility of Polishing Concave Surfaces Using Magnetic Compound Fluid Slurry

2021 ◽  
Vol 15 (1) ◽  
pp. 34-40
Author(s):  
Ming Feng ◽  
Yingrui Xie ◽  
Leran Chen ◽  
Yongbo Wu ◽  
◽  
...  
Keyword(s):  
Surface Quality ◽  
Flat Surface ◽  
Surface Profile ◽  
High Standard ◽  
Concave Surface ◽  
Smart Devices ◽  
Polishing Process ◽  
First Time ◽  
The Magnetic Field

Concave surfaces are widely used in the shells of smart devices, such as smartphones, watches, or molds. The quality of the concave surface is important in enhancing the value of these products. In order to improve the surface quality, the polishing process is crucial for removing defects on the concave surface and for smoothing the surface after machining or grinding. Magnetic assisted polishing is a promising method that can be used to meet the high standard of surface quality required. In this work, as a promising smart material in nano-precision polishing, magnetic compound fluid (MCF) slurry was used for the first time to polish a concave surface with a magnet that is magnetized in the radial direction. A simulation of the magnetic field distribution was performed in advance to clarify the polishing characteristics in theory. Subsequently, a polishing experiment was conducted to investigate the feasibility of this polishing method. Finally, the results demonstrated that both a curved surface and a flat surface could be polished successfully. Furthermore, the nano-precision PV value (the distance from the peak to the valley in the surface profile) and the surface roughness Ra were obtained for both areas, and this method was demonstrated to be capable of polishing concave surfaces and worthy of further research.

Communication Sciences and Disorders PhD Graduates' Perceptions of Their PhD Program

2020 ◽  
Vol 5 (2) ◽  
pp. 463-478
Author(s):  
Elizabeth Crais ◽  
Melody Harrison Savage
Keyword(s):  
Detailed Examination ◽  
Career Expectations ◽  
Doctoral Preparation ◽  
Creative Solutions ◽  
Phd Education ◽  
Doctor Of Philosophy ◽  
First Time ◽  
Students Success ◽  
Phd Program

Purpose The shortage of doctor of philosophy (PhD)–level applicants to fill academic and research positions in communication sciences and disorders (CSD) programs calls for a detailed examination of current CSD PhD educational practices and the generation of creative solutions. The intended purposes of the article are to encourage CSD faculty to examine their own PhD program practices and consider the perspectives of recent CSD PhD graduates in determining the need for possible modifications. Method The article describes the results of a survey of 240 CSD PhD graduates and their perceptions of the challenges and facilitators to completing a PhD degree; the quality of their preparation in research, teaching, and job readiness; and ways to improve PhD education. Results Two primary themes emerged from the data highlighting the need for “matchmaking.” The first time point of needed matchmaking is prior to entry among students, mentors, and expectations as well as between aspects of the program that can lead to students' success and graduation. The second important matchmaking need is between the actual PhD preparation and the realities of the graduates' career expectations, and those placed on graduates by their employers. Conclusions Within both themes, graduate's perspectives and suggestions to help guide future doctoral preparation are highlighted. The graduates' recommendations could be used by CSD PhD program faculty to enhance the quality of their program and the likelihood of student success and completion. Supplemental Material https://doi.org/10.23641/asha.11991480

Schwingungsüberlagertes Axialformen/Superimposed Oscillated Axial Forming

2020 ◽  
Vol 110 (11-12) ◽  
pp. 838-843
Author(s):  
Philipp Müller ◽  
Bernd-Arno Behrens ◽  
Sven Hübner ◽  
Hendrik Vogt ◽  
Daniel Rosenbusch ◽  
...  
Keyword(s):  
Surface Quality ◽  
Economic Importance ◽  
Combined Effect ◽  
Wird Eine ◽  
Forming Force ◽  
Forming Process ◽  
Forming Technology ◽  
Great Economic Importance ◽  
Gear Geometry

Techniken zur Steigerung der Formgebungsgrenzen in der Umformtechnik sind von hoher wirtschaftlicher Bedeutung. In dieser Arbeit wird eine Schwingungsüberlagerung im Krafthauptfluss eines Axialformprozesses zur Ausprägung einer Verzahnungsgeometrie untersucht. Die Auswirkungen der Schwingung auf die erzielbare Ausfüllung der Zahnkavitäten werden analysiert sowie die Parameter Schmierung und Oberflächengüte der Halbzeuge in ihrer kombinierten Wirkung untersucht. Es konnte eine Reduzierung der mittleren Umformkraft sowie eine Erhöhung der Formfüllung festgestellt werden. Techniques for extending the production limits in forming technology are of great economic importance. In this research, a superimposed oscillation in the main force flow of an axial forming process to form an axial gear geometry is investigated. The effects of the superimposed oscillation on the achievable form-filling of the tooth cavities are analyzed and the parameters lubrication and surface quality of the semi-finished products are investigated in their combined effect. A reduction of the averaged forming force as well as an increase of the form-filling could be achieved.

Resveratrol: A new potential therapeutic agent for melanoma?

2019 ◽  
Vol 26 ◽  
Author(s):  
Mohamad Hossein Pourhanifeh ◽  
Kazem Abbaszadeh-Goudarzi ◽  
Mohammad Goodarzi ◽  
Sara G.M. Piccirillo ◽  
Alimohammad Shafiee ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Therapeutic Agent ◽  
Current Knowledge ◽  
Treatment Resistance ◽  
Anti Cancer ◽  
Apoptosis Inducer ◽  
Life Threatening ◽  
First Time

: Melanoma is the most life-threatening and aggressive class of skin malignancies. The incidence of melanoma has steadily increased. Metastatic melanoma is greatly resistant to standard anti-melanomatreatments such as chemotherapy, and 5-year survival rate of cases with melanoma who have metastatic form of disease is less than 10%. The contributing role of apoptosis, angiogenesis and autophagy in the pathophysiology of melanoma has been previously demonstrated. Thus, it is extremely urgent to search for complementary therapeutic approachesthat couldenhance the quality of life of subjects and reduce treatment resistance and adverse effects. Resveratrol, known as a polyphenol component present in grapes and some plants, has anti-cancer properties due to its function as an apoptosis inducer in tumor cells, and anti-angiogenic agent to prevent metastasis. However, more clinical trials should be conducted to prove resveratrol efficacy. : Herein, for first time, we summarize current knowledge of anti-cancerous activities of resveratrol in melanoma.

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