scholarly journals Optimizing Slag Content to Control Ds-Type Inclusions in 10B21 Cold Heading Steel

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1016
Author(s):  
Zhaoqi Song ◽  
Wei Liu ◽  
Yuhang Liu ◽  
Yongfeng Chen ◽  
Xiaotan Zuo ◽  
...  

Ds-type inclusions during production are an important factor affecting the performance and quality of manufactured 10B21 steel. To minimize Ds-type inclusions in steel and improve the production qualification rate of steelmaking plants, a refining slag system optimization scheme was proposed based on the analysis of current inclusion evolution during the steelmaking process, and industrial tests were conducted to verify improvements resulting from application of the proposed scheme. The results showed that the composition of Ds inclusions in 10B21 steel are mainly CaO–Al2O3–MgO–CaS–TiN, which exists in the form of calcium–magnesium aluminate coated with titanium nitride and calcium sulfide. The main reason for the formation of Ds inclusions is the poor fluidity of the refining slag and its low capability to absorb inclusions. The poor coverage of the refining slag on the molten steel during refining can easily cause secondary oxidation of the molten steel. Thus, the formation and growth of Ds-type inclusions are aggravated after the calcium feeding line and soft blowing operation. Here, we propose to minimize Ds inclusions using our optimized refined slag system. The mass percentage of the optimized slag system is CaO: 55–60%, Al2O3: 20–35%, SiO2: 3–7%, MgO: 4–8%, (MnO + FeO) < 1%, and the basicity is controlled within the range of 7–11. We observed that our optimized refining slag system has a significantly improved ability to remove inclusions, particularly Ds inclusions, which improves the qualification rate of 10B21 steel.

2021 ◽  
Vol 118 (2) ◽  
pp. 214
Author(s):  
Tongsheng Zhang ◽  
Rensheng Li ◽  
Wanlin Wang ◽  
Shifan Dai ◽  
Peisheng Lv ◽  
...  

Pipeline steel is widely used in various industries, and the sulfur content and inclusions in steel have a significant impact on performance, which determines whether the steel quality is qualified. The experiments were carried out to explore the sulfur content and inclusion evolution of pipeline steel which was deoxidized by Si–Mn–Al with “EAF-LF-VD-T-CC”. The samples of molten steel and slag were taken during the process of LF-VD-Tundish after EAF tapping. The kinetics model was established to simulate the desulfuration process of molten steel in actual production, obtaining a result which the error is within 3 ppm. It can be summarized that proper calcium treatment can transform the inclusion into a liquid inclusion, the value of [Ca] ranges from 25 to 45 ppm. Too high and lower calcium treatment can cause the compositions of inclusions to deviate from the liquid phase area, while too low calcium treatment will increase the overall size and density of the inclusions. In addition, the evolution of inclusion in steel at refining temperature and during solidification process was comprehensively calculated, considering all types of inclusions such as calcium oxide, magnesium oxide, aluminum oxide, calcium sulfide, spinel, calcium aluminate and liquid inclusion. The thermodynamic calculations are in good agreement with experimental results, which can predict the formation of the inclusions in Si–Mn–Al deoxidized pipeline steel.


2019 ◽  
Vol 11 (1) ◽  
pp. 51-56
Author(s):  
RIANI PRADARA JATI ◽  
Sekar Farah Nabila

  Penempatan peran yang baik bagi Family Caregiver sangatlah membantu lansia dalam meningkatkah qualitas hidupnya, meningkatkan motivasi dalam menjalankan hidup Penelitian ini bertujuan Mengetahui hubungan peran Family Caregiver dalam pemenuhan qualitas hidup bagi lansia di Kelurahan Langenharjo Kabupaten Kendal. DesainPenelitianDeskriptifKorelasional menggunakan pendekatan Krosectional,tehnikSamplingStratified Simple Random Sampling dengan karakteristik heterogen, dari populasi mempunyai hak yang sama untuk diseleksi sebagai sampel teknik undianPengambilan data dengan menggunakan kuesioner yang telah diuji validitas dan reliabilitasnya. Uji statistik Chi-square, dengan taraf signifikasi 5%jumlah sampel pada penelitian ini 70 sampel pada Family Caregiver dari 213 populasi yang ada. Hasil penelitian dari 70 responden didapatkan Peran Family Caregiver tidak baik dengan qualitas hidup tidak baik 33 (47,1%), sedangkan Peran Family Caregiver kurang baik dengan qualitas hidup lansia baik 3 (4,3%). Untuk distribusi Peran Family Caregiver kurang baik dengan qualitas hidup lansia tidak baik sebanyak 6 responden (8,6%) sedangkan untuk distribusi Peran Family Caregiver kurang baik dengan qualitas hidup lansia baik sebanyak 23 responden (32,9%). Terakhir, untuk distribusi Peran Family Caregiver baik dengan qualitas hidup lansia tidak baik didapatkan hasil 2 responden (2, 9%) sedangkan untuk distribusi Peran Family Caregiver baik dengan qualitas hidup lansia baik didapatkan hasil 3 responden (4,3%)Menunjukkan nilai ρ value 0,001 (ρ < 0,05) berarti ada hubungan antara dukungan keluarga dengan kepatuhan lansia dalam keikutsertaan posyandu lansia. Disarankan kepada semua Family Cregiver lansia untuk mampu memahami pentingnya perhatian, dukungan bagi lansia dalammeningkatkan qualitas hidup yang lebih baik bagi lansia.   Kata kunci : Peran family caregiver, qualitas hidup, lansia.   ABSTRACT Placement of a good role for Family Caregiver is very helpful for the elderly to improve their quality of life, increase motivation in living life Research Objective: To know the relationship between the role of Family Caregiver in fulfilling quality of life for the elderly in Langenharjo Village, Kendal Regency. Descriptive Correlational Research Design uses a cross sectional approach, Sampling Stratified Simple Random Sampling technique with heterogeneous characteristics, from the population has the same right to be selected as a sample lottery technique Retrieving data using a questionnaire that has been tested for validity and reliability. Test Chi-square statistics, with a significance level of 5% the number of samples in this study 70 samples on the Family Caregiver from 213 populations. Results of the Study Of 70 respondents found the role of Family Caregiver was not good with poor quality of life 33 (47.1%) , while the role of the Family Caregiver is not good with the quality of life of a good elderly 3 (4.3%). For the distribution of the role of Family Caregiver is not good with the quality of life of the poor family as many as 6 respondents (8.6%) while for the distribution of the Role of Family Caregiver is not good with the quality of life of good elderly as many as 23 respondents (32.9%). Finally, the distribution of the Role of Family Caregiver with good quality of life for the poor is obtained by 2 respondents (2, 9%), while the distribution of the Role of Family Caregiver with good quality of life for the elderly is obtained by 3 respondents (4.3%). 0.001 (ρ <0.05) means that there is a relationship between family support and the compliance of the elderly in the participation of the elderly posyandu. It is recommended to all elderly Cregiver families to be able to understand the importance of attention, support for the elderly in improving the quality of life better for the elderly   Keywords: Role of Family Caregiver, Quality of Life, Elderly


2020 ◽  
pp. 34-36
Author(s):  
M. A. Pokhaznikova ◽  
E. A. Andreeva ◽  
O. Yu. Kuznetsova

The article discusses the experience of teaching and conducting spirometry of general practitioners as part of the RESPECT study (RESearch on the PrEvalence and the diagnosis of COPD and its Tobacco-related aetiology). A total of 33 trained in spirometry general practitioners performed a study of 3119 patients. Quality criteria met 84.1% of spirometric studies. The analysis of the most common mistakes made by doctors during the forced expiratory maneuver is included. The most frequent errors were expiration exhalation of less than 6s (54%), non-maximal effort throughout the test and lack of reproducibility (11.3%). Independent predictors of poor spirogram quality were male gender, obstruction (FEV1 /FVC<0.7), and the center where the study was performed. The number of good-quality spirograms ranged from 96.1% (95% CI 83.2–110.4) to 59.8% (95% CI 49.6–71.4) depending on the center. Subsequently, an analysis of the reasons behind the poor quality of research in individual centers was conducted and the identified shortcomings were eliminated. The poor quality of the spirograms was associated either with the errors of the doctors who undertook the study or with the technical malfunctions of the spirometer.


2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Ani Saifuza Abd Shukor ◽  
Muhammad Fadhil Muhammad ◽  
Shamsida Saidan Khaderi ◽  
Faridah Muhammad Halil

The shift to an integrated IBS construction approach requires enhanced supply chain integration to improve the productivity as well as the poor quality of human behavioual aspect in IBS project. This paper is to identify the challenges at each tier between players to facilitate supply chain integration among the IBS players. Findings adopted from semi-structured interview revealed the critical attitude issues of human factors, lack of interaction and sharing knowledge between interdisciplinary people. The findings of this study is useful to improve integration of supply chain and enhance innovation and sharing interaction between players in the IBS Malaysian construction project environment.© 2016. The Authors. Published for AMER ABRA by e-International Publishing House, Ltd., UK. Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.Keywords: Construction Environment; Industrialised Building System; Integration and Supply Chain 


2020 ◽  
pp. 1-17
Author(s):  
Vikas Kumar

The quality of metadata is a crucial determinant of usability/interpretability of data. This paper draws attention to the poor quality of India’s government statistics and the paucity of metadata necessary to understand the problems. The paper suggests that there has been a decline in India both in terms of the availability and quality of metadata for key government sources of information including maps, decennial population censuses and National Sample Surveys amidst growing sophistication in the understanding of metadata. The poor quality of metadata impairs cross-sectional as well as inter-temporal comparisons and policymaking apart from concealing biases and lapses of government statisticians. The paper draws on the experience of three states – erstwhile Jammu and Kashmir, Manipur and Nagaland – where government statistics have been affected by serious errors that are not well-understood due to the lack of adequate metadata.


2011 ◽  
Vol 243-249 ◽  
pp. 1360-1365 ◽  
Author(s):  
Wei Rong Lü ◽  
Meng Wang ◽  
Xi Jun Liu

The micro-model, which the brick and the mortar model are separated, is used to analyze masonry. Meanwhile, the mortar is divided into three layers along the thickness direction to obtain the internal mechanical behavior of mortar, and the vertical mortar joint strength is taken as 50% strength of the horizontal mortar joint for considering the poor quality of vertical mortar joint. The compressive ultimate load and failure mode of masonry taken from the finite element analysis result, especially the vertical cracks throughout all bricks and mortar and change of brick and mortar strain, are in agreement with the experimental results. It shows that the micro-model and method adopted in paper are able to effectively apply in nonlinear structural analysis for masonry.


2014 ◽  
Vol 50 (3) ◽  
pp. 671-704 ◽  
Author(s):  
CHRISTINA BEHME

The Science of Language, published in the sixth decade of Noam Chomsky's linguistic career, defends views that are visibly out of touch with recent research in formal linguistics, developmental child psychology, computational modeling of language acquisition, and language evolution. I argue that the poor quality of this volume is representative of the serious shortcomings of Chomsky's recent scholarship, especially of his criticism of and contribution to debates about language evolution. Chomsky creates the impression that he is quoting titbits of a massive body of scientific work he has conducted or is intimately familiar with. Yet his speculations reveal a lack of even basic understanding of biology, and an unwillingness to engage seriously with the relevant literature. At the same time, he ridicules the work of virtually all other theorists, without spelling out the views he disagrees with. A critical analysis of the ‘Galilean method’ demonstrates that Chomsky uses appeal to authority to insulate his own proposals against falsification by empirical counter-evidence. This form of discourse bears no serious relation to the way science proceeds.


2021 ◽  
pp. 097152312110163
Author(s):  
A. H. M. Kamrul Ahsan ◽  
Peter Walters ◽  
Md. Adil Khan

This study compares the state of city government service delivery for communities living in different areas with different level of affluence in Rajshahi City in Bangladesh. Based on the results of a qualitative study, we found a significant service disparity between the affluent and the poor communities. This disparity is due to the inability of the poor to hold service providers accountable, attributable to a lack of knowledge about services and a lack of social status. Lack of quality monitoring and a marked bias in the quality of interactions between the poor and the affluent contribute to the service disparity This disparity is largely invisible to the poor who, instead of comparing themselves with the affluent citizens, compare themselves with a similar class of people.


2011 ◽  
Vol 291-294 ◽  
pp. 423-427
Author(s):  
Yan Juan Jin ◽  
Xiao Chao Cui ◽  
Zhu Zhang

An inner-outer coupled cooling technology of molten steel for 1240×200mm slab continuous casting, that is to set an inner cooler—U shape pipes in the mold, is put forward in order to enhance the efficiency of transmitting heat and improve inner structure of billet. The flow status and solidification status of molten steel under coupling flow field and temperature field in inner-outer coupled cooling mold are simulated by using fluid dynamics software, and compare with those in traditional mold. It is found that setting inner cooler in the mold can make molten steel flow status even, which is favorable to floating up of the inclusion, quickening the solidification of steel liquid and improving the quality of billet.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Grace Frimpong ◽  
Kwabena Ofori-Kwakye ◽  
Noble Kuntworbe ◽  
Kwame Ohene Buabeng ◽  
Yaa Asantewaa Osei ◽  
...  

The quality of 68 samples of 15 different essential children’s medicines sold in licensed medicine outlets in the Ashanti Region, Ghana, was evaluated. Thirty-two (47.1%) of the medicines were imported, mainly from India (65.6%) and the United Kingdom (28.1%), while 36 (52.9%) were locally manufactured. The quality of the medicines was assessed using content of active pharmaceutical ingredient (API), pH, and microbial limit tests, and the results were compared with pharmacopoeial standards. Twenty-six (38.2%) of the samples studied passed the official content of API test while 42 (61.8%) failed. Forty-nine (72.1%) of the samples were compliant with official specifications for pH while 19 (27.9%) were noncompliant. Sixty-six (97.1%) samples passed the microbial load and content test while 2 (2.9%) failed. Eighteen (26.5%) samples passed all the three quality evaluation tests, while one (1.5%) sample (CFX1) failed all the tests. All the amoxicillin suspensions tested passed the three evaluation tests. All the ciprofloxacin, cotrimoxazole, flucloxacillin, artemether-lumefantrine, multivitamin, and folic acid samples failed the content of API test and are substandard. The overall API failure rate for imported products (59.4%) was comparable to locally manufactured (63.9%) samples. The results highlight the poor quality of the children’s medicines studied and underscore the need for regular pharmacovigilance and surveillance systems to fight this menace.


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