Perfection of the equipment of electromagnetic stirring in moulds of billet and bloom CCM

Author(s):  
S. I. Shakhov ◽  
B. A. Sivak ◽  
K. N. Vdovin ◽  
D. S. Shakhov ◽  
R. I. Kerimov ◽  
...  

To avoid defects of continuously casted billets, such as core porosity, shrink liquation, ingot developed dendrite structure and others, various methods of external physical impact on the crystallizing billet are used. One of the most technological and effective of them is the electromagnetic stirring (EMS) of the liquid melt of the crystallizing billet. An analysis of the experience of industrial EMS systems application at steel plants of Russia was accomplished. It was noted, that operating in Russia industrial CCM, intended for production of high quality billets, are equipped mainly by EMS systems of foreign production. The stator of the EMS is located outside a mould body and the bodies of the stator and the mould are manufactured of nonmagnetic steel of austenite class. Such systems are characterized by low reliability and high energy consumption because of their design features (location outside a mould body and necessity to use for them a separate circuit of cooling by a “boiler” water). Bessides, most of the EMS stators of foreign manufacturing are made in nonseparable bodies, hence in case of a failure the expensive rrepair of the stators should be carried out at the foreign plants-manufacturers. At present in Russia the EMS systems are being elaboorrated by specialists of AKKH “VNIIMETMASH”, Moscow. VNIIMETMASH within the frame of import substitution program elaboorated both built-in and external variants of EMS systems for moulds of billet and bloom CCM, the stator coil poles being cooled bby the water of the mould and its winding is made of immersible into water wire with a double insulation. Based on the results of thee study it was determined, that location of the elaborated EMS systems in a mould results in improving of the surface quality, as welll as quality of the subsurface layer and the billet macro-structure, decreasing of the point unevenness and decreasing of number of thee subshell bubbles.

2005 ◽  
Vol 291-292 ◽  
pp. 39-44 ◽  
Author(s):  
Berend Denkena ◽  
M. Reichstein ◽  
Niklas Kramer ◽  
J. Jacobsen ◽  
M. Jung

Eco-efficiency of manufacturing processes is increasingly important. Here grinding is supposed to be unfavorable because of the need for coolant and a high energy consumption per removed material volume. Nevertheless, it can be not be substituted by an alternative process due to the superior quality of ground parts. The overall eco-efficiency of grinding can be improved by different approaches. A better understanding of grinding processes and a modified setup of the process chain minimizes the material to be removed by grinding. Design changes of the machine tool can significantly reduce the energy consumption of additional devices as coolant supply units without a loss of flexibility. Adapted process parameters increase eco-efficiency and can also improve cost effectiveness while maintaining part quality.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1771
Author(s):  
Eden Teshome ◽  
Diana Deac ◽  
Steffen Thielemans ◽  
Matthias Carlier ◽  
Kris Steenhaut ◽  
...  

Smart buildings benefit from IEEE 802.15.4e time slotted channel hopping (TSCH) medium access for creating reliable and power aware wireless sensor and actuator networks (WSANs). As in these networks, sensors are supposed to communicate to each other and with actuators, IPv6 multicast forwarding is seen as a valuable means to reduce traffic. A promising approach to multicast, based on the Routing Protocol for Low Power and Lossy Networks (RPL) is Bidirectional Multicast RPL Forwarding (BMRF). This paper aimed to analyze the performance of BMRF over TSCH. The authors investigated how an adequate TSCH scheduler can help to achieve a requested quality of service (QoS). A theoretical model for the delay and energy consumption of BMRF over TSCH is presented. Next, BMRF’s link layer (LL) unicast and LL broadcast forwarding modes were analyzed on restricted and realistic topologies. On topologies with increased interference, BMRF’s LL broadcast on top of TSCH causes high energy consumption, mainly because of the amount of energy needed to run the schedule, but it significantly improves packet delivery ratio and delay compared to ContikiMAC under the same conditions. In most cases, the LL unicast was found to outperform the LL broadcast, but the latter can be beneficial to certain applications, especially those sensitive to delays.


2020 ◽  
Vol 12 (18) ◽  
pp. 7606 ◽  
Author(s):  
Artur Głuchowski ◽  
Ewa Czarniecka-Skubina ◽  
Maria Buła

Nowadays, the reduction of food waste, as well as protection of the nutritional value, are significant trends in domestic and catering food processing. Among the trends are innovations in food technology like sous-vide. The aim of this study was to evaluate the effect of sous vide cooking on the technological, nutritional, and microbiological quality of the chicken breast as well as to compare it to conventional methods (boiling and steaming). Meats after low-temperature sous-vide heat treatment were characterized by a significantly higher yield (p ≤ 0.05) and water content than those prepared with conventional methods. The energy and time consumption of sous-vide preparation was 5–10 times higher than other methods. The examined heat treatments resulted in a good microbiological quality of samples. The nutritional value of sous-vide products depended on the process parameters. A higher temperature and sous-vide processing time resulted in a higher content of dry matter, protein, and fat in the meat and was close to that of conventional methods. Low parameters of the process resulted in the least changed profile of fatty acids in meat. The use of the sous-vide method protects the nutritional value and allows for the extension of the shelf life of the meat which ultimately reduces food waste. The sous-vide heat treatment method is more suitable for foodservice than use in home conditions because of high energy consumption, despite the protection of nutrition value.


1993 ◽  
Vol 28 (2) ◽  
pp. 17-26 ◽  
Author(s):  
V. Eroǧlu ◽  
A. M. Saatçi

Recent advances made in the reuse of pulp and paper industry sludges in hardboard production are explained. Data obtained from pilot and full-scale plants using primary sludge of a pulp and paper industry as an additive in the production of hardboard is presented. An economic analysis of the reuse of pulp and paper primary sludge in hardboard manufacturing is given. The quality of the hardboard produced is tested and compared with the qualities of the hardboard produced by the same plant before the addition of primary sludge. The hardboard with primary sludge additive has been used in Turkey for about a year in the manufacturing of office and home furniture. The results are very satisfactory when the primary sludge is used at 1/4 ratio.


2013 ◽  
Vol 652-654 ◽  
pp. 2450-2454
Author(s):  
Zhi Hong Zhang ◽  
Guo Guang Cheng

The paper describes multi-section round bloom casting using external MEMS, equipped with max section D600mm and min D280mm mold, the center line of D280mm mold not coincident with the axis of stirrer coils. it is exist eccentric electromagnetic stirring of mold which section less than max D600mm, a mathematical model of MEMS has been established, the index of central segregation of D280mm macrostructure had decreased less than 1.12 by optimized parameters of electromagnetic stirring and SEN immerse depth, in the end, the quality of round bloom had improved.


2021 ◽  
Vol 10 (4) ◽  
pp. 196
Author(s):  
Julio Manuel de Luis-Ruiz ◽  
Benito Ramiro Salas-Menocal ◽  
Gema Fernández-Maroto ◽  
Rubén Pérez-Álvarez ◽  
Raúl Pereda-García

The quality of human life is linked to the exploitation of mining resources. The Exploitability Index (EI) assesses the actual possibilities to enable a mine according to several factors. The environment is one of the most constraining ones, but its analysis is made in a shallow way. This research is focused on its determination, according to a new preliminary methodology that sets the main components of the environmental impact related to the development of an exploitation of industrial minerals and its weighting according to the Analytic Hierarchy Process (AHP). It is applied to the case of the ophitic outcrops in Cantabria (Spain). Twelve components are proposed and weighted with the AHP and an algorithm that allows for assigning a normalized value for the environmental factor to each deposit. Geographic Information Systems (GISs) are applied, allowing us to map a large number of components of the environmental factors. This provides a much more accurate estimation of the environmental factor, with respect to reality, and improves the traditional methodology in a substantial way. It can be established as a methodology for mining spaces planning, but it is suitable for other contexts, and it raises developing the environmental analysis before selecting the outcrop to be exploited.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Donato Lacedonia ◽  
Giulia Scioscia ◽  
Piera Soccio ◽  
Massimo Conese ◽  
Lucia Catucci ◽  
...  

Abstract Background Idiopathic Pulmonary Fibrosis (IPF) is a degenerative interstitial lung disease with both a poor prognosis and quality of life once the diagnosis is made. In the last decade many features of the disease have been investigated to better understand the pathological steps that lead to the onset of the disease and, moreover, different types of biomarkers have been tested to find valid diagnostic, prognostic and therapy response predictive ones. In the complexity of IPF, microRNA (miRNAs) biomarker investigation seems to be promising. Methods We analysed the expression of five exosomal miRNAs supposed to have a role in the pathogenesis of the disease from serum of a group of IPF patients (n = 61) and we compared it with the expression of the same miRNAs in a group of healthy controls (n = 15). Results In the current study what emerged is let-7d down-regulation and, unexpectedly, miR-16 significant down-regulation. Moreover, through a cross-sectional analysis, a clustering of the expression of miR-16, miR-21 and miR-26a was found. Conclusions These findings could help the individuation of previously unknown key players in the pathophysiology of IPF and, most interestingly, more specific targets for the development of effective medications.


2021 ◽  
pp. 036354652199800
Author(s):  
Jani Puhakka ◽  
Teemu Paatela ◽  
Eve Salonius ◽  
Virpi Muhonen ◽  
Anna Meller ◽  
...  

Background: The International Cartilage Repair Society (ICRS) score was designed for arthroscopic use to evaluate the quality of cartilage repair. Purpose: To evaluate the reliability of the ICRS scoring system using an animal cartilage repair model. Study Design: Controlled laboratory study. Methods: A chondral defect with an area of 1.5 cm2 was made in the medial femoral condyle of 18 domestic pigs. Five weeks later, 9 pigs were treated using a novel recombinant human type III collagen/polylactide scaffold, and 9 were left to heal spontaneously. After 4 months, the pigs were sacrificed, then 3 arthroscopic surgeons evaluated the medial femoral condyles via video-recorded simulated arthroscopy using the ICRS scoring system. The surgeons repeated the evaluation twice within a 9-month period using their recorded arthroscopy. Results: The porcine cartilage repair model produced cartilage repair tissue of poor to good quality. The mean ICRS total scores for all observations were 6.6 (SD, 2.6) in arthroscopy, 5.9 (SD, 2.7) in the first reevaluation, and 6.2 (SD, 2.8) in the second reevaluation. The interrater reliability with the intraclass correlation coefficient (ICC) for the ICRS total scores (ICC, 0.46-0.60) and for each individual subscore (ICC, 0.26-0.71) showed poor to moderate reliability. The intrarater reliability with the ICC also showed poor to moderate reliability for ICRS total scores (ICC, 0.52-0.59) and for each individual subscore (ICC, 0.29-0.58). A modified Bland-Altman plot for the initial arthroscopy and for the 2 reevaluations showed an evident disagreement among the observers. Conclusion: In an animal cartilage repair model, the ICRS scoring system seems to have poor to moderate reliability. Clinical Relevance: Arthroscopic assessment of cartilage repair using the ICRS scoring method has limited reliability. We need more objective methods with acceptable reliability to evaluate cartilage repair outcomes.


2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Matthieu J. S. Brinkhuis ◽  
Alexander O. Savi ◽  
Abe D. Hofman ◽  
Frederik Coomans ◽  
Han L. J. Van der Maas ◽  
...  

With the advent of computers in education, and the ample availability of online learning and practice environments, enormous amounts of data on learning become available. The purpose of this paper is to present a decade of experience with analyzing and improving an online practice environment for math, which has thus far recorded over a billion responses. We present the methods we use to both steer and analyze this system in real-time, using scoring rules on accuracy and response times, a tailored rating system to provide both learners and items with current ability and difficulty ratings, and an adaptive engine that matches learners to items. Moreover, we explore the quality of fit by means of prediction accuracy and parallel item reliability. Limitations and pitfalls are discussed by diagnosing sources of misfit, like violations of unidimensionality and unforeseen dynamics. Finally, directions for development are discussed, including embedded learning analytics and a focus on online experimentation to evaluate both the system itself and the users’ learning gains. Though many challenges remain open, we believe that large steps have been made in providing methods to efficiently manage and research educational big data from a massive online learning system.


1993 ◽  
Vol 28 (7) ◽  
pp. 243-250 ◽  
Author(s):  
Y. Suzuki ◽  
S. Miyahara ◽  
K. Takeishi

Gas-permeable film can separate air and water, and at the same time, let oxygen diffuse from the air to the water through the film. An oxygen supply method using this film was investigated for the purpose of reducing energy consumption for wastewater treatment. The oxygen transfer rate was measured for the cases with or without biofilm, which proved the high rate of oxygen transfer in the case with nitrifying biofilm which performed nitrification. When the Gas-permeable film with nitrifying biofilm was applied to the treatment of wastewater, denitrifying biofilm formed on the nitrifying biofilm, and simultaneous nitrification and denitrification occurred, resulting in the high rate of organic matter and T-N removal (7 gTOC/m2/d and 4 gT-N/m2/d, respectively). However, periodic sloughing of the denitrifying biofilm was needed to keep the oxygen transfer rate high. Energy consumption of the process using the film in the form of tubes was estimated to be less than 40% of that of the activated sludge process.


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