Rubberised fabric for fuel soft storage tanks*

2018 ◽  
Vol 45 (7) ◽  
pp. 322-324
Author(s):  
Yu.N. Rybakov ◽  
A.V. Dedov ◽  
D.S. Plokhoi ◽  
D.V. Kolotilin
Keyword(s):  
Diffusion Processes ◽  
Motor Fuel ◽  
Residual Monomer ◽  
Experimental Conditions ◽  
Second Stage ◽  
Before And After ◽  
Nitrile Rubbers ◽  
Two Stages ◽  
Kinetics Of

The kinetics of extraction of dibutyl sebacinate by different grades of motor fuel from rubberised fabric based on a blend of nitrile rubbers SKN-26M and SKN-40M was investigated. The kinetics was determined according to the GOST 9.030-74 standard from the change in weight of the specimen after holding in fuel at 50°C and drying. The change in quality of the fuel after contact with the fabric was recorded from the change in the content of existent gum in fuel according to GOST 1567-97 (ISO 6246-95) and its acidity according to GOST 5985-79 before and after contact with the rubberised fabric. It was shown that the process of extraction proceeds in two stages, the time of the first of which under experimental conditions is not dependent on the type of fuel. The rate of the first stage is much higher than the rate of the second stage. The relation of rates and proportion of extracted fuel at the first and second stages depends on the type of fuel. It can be asserted that the surplus amount of extracted substances is made up of impurities, which include residual monomer or its derivatives and substances used in the synthesis of the rubber. The mechanism of extraction with extractant counterflow into the vulcanisate and its dependence on the grade of petrol is proposed, based on allowance for the diffusion processes in the system.

Metal Dusting Corrosion of 9Cr-1Mo Steel in Propane-Butane Gas Mixture

2009 ◽  
Vol 289-292 ◽  
pp. 477-483
Author(s):  
Zbigniew Grzesik ◽  
Marek Danielewski ◽  
Stanisław Mrowec
Keyword(s):  
Total Pressure ◽  
Petrochemical Industry ◽  
Diffusion Processes ◽  
Metal Dusting ◽  
Second Stage ◽  
Reaction Proceeds ◽  
Two Stages ◽  
Kinetics Of ◽  
Low Rate ◽  
Propane Butane

The kinetics and mechanism of metal dusting corrosion of 9Cr-1Mo steel, commonly used in CCR platforming units, have been studied as a function of temperature (773 – 1173 K) in propane-butane atmosphere, being the mixture of 70 vol. % of propane and 30 vol. % of butane with the total pressure equal 105 Pa. The kinetics of corrosion have been studied thermogravimetrically in the apparatus enabling the mass changes of corroded sample to be followed continuously with the accuracy of the order of 10-6 g. It has been found that metal dusting corrosion in this atmosphere, modeling in some way industrial environments in petrochemical industry, is complex and two-stages of linear kinetics may be distinguished. In the first stage, which may be considered as an incubation period, the reaction proceeds with rather low rate, which increases dramatically in the second stage, the beginning of which depends strongly on temperature. Linear course of reaction indicates that chemical reactions and not diffusion processes determine the rate of corrosion. This conclusion is confirmed by the fact, that the layer of corrosion products is not compact but considerably porous.

scholarly journals Eco-Friendly Fired Brick Produced from Industrial Ash and Natural Clay: A Study of Waste Reuse

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 877 ◽  
Author(s):  
Neslihan Doğan-Sağlamtimur ◽  
Ahmet Bilgil ◽  
Magdalena Szechyńska-Hebda ◽  
Sławomir Parzych ◽  
Marek Hebda
Keyword(s):  
Compressive Strength ◽  
Bottom Ash ◽  
Unit Weight ◽  
Waste Reuse ◽  
Industrial Solid Waste ◽  
Second Stage ◽  
Before And After ◽  
Fired Bricks ◽  
Two Stages ◽  
And Storage

Bottom ash (BA) is an industrial solid waste formed by the burning of coal. The environmental problems and storage costs caused by this waste increase with every passing day. In this study, the use of BA as an additive (clay substitute) in fired brick production was investigated. The study consisted of two stages. In the first stage, cylinder blocks were produced from clay used in brick production. The second stage was the examination of the experimental substitution of clay with 10, 20, 30 and 40% BA. Samples were fired at 900, 1000, 1100 and 1150 °C to produce fired brick samples. The unit weight, compressive strength (before and after freeze–thawing) and water absorption were analyzed for the samples. The unit weight values decreased in the samples containing BA. The mechanical properties met the conditions prescribed in the relevant standards; i.e., all of the samples fired at 1100 and 1150 °C had a sufficient compressive strength over 20 MPa. The high potential of fired bricks for the construction industry was proved. BA can be used as a clay substitute, while the developed protocol can be used to effectively produce fired bricks.

A novel two-stage method of plant seedlings classification based on deep learning

2021 ◽  
pp. 1-11
Author(s):  
Tianhong Dai ◽  
Shijie Cong ◽  
Jianping Huang ◽  
Yanwen Zhang ◽  
Xinwang Huang ◽  
...  
Keyword(s):  
Deep Learning ◽  
Learning Technology ◽  
Two Stage ◽  
Second Stage ◽  
Stage Classification ◽  
Different Types ◽  
Two Stages ◽  
Plant Seedlings

In agricultural production, weed removal is an important part of crop cultivation, but inevitably, other plants compete with crops for nutrients. Only by identifying and removing weeds can the quality of the harvest be guaranteed. Therefore, the distinction between weeds and crops is particularly important. Recently, deep learning technology has also been applied to the field of botany, and achieved good results. Convolutional neural networks are widely used in deep learning because of their excellent classification effects. The purpose of this article is to find a new method of plant seedling classification. This method includes two stages: image segmentation and image classification. The first stage is to use the improved U-Net to segment the dataset, and the second stage is to use six classification networks to classify the seedlings of the segmented dataset. The dataset used for the experiment contained 12 different types of plants, namely, 3 crops and 9 weeds. The model was evaluated by the multi-class statistical analysis of accuracy, recall, precision, and F1-score. The results show that the two-stage classification method combining the improved U-Net segmentation network and the classification network was more conducive to the classification of plant seedlings, and the classification accuracy reaches 97.7%.

scholarly journals Awareness of COVID-19 Before and After Quarantine Based on Crowdsourced Data From Rabigh City, Saudi Arabia: A Cross-Sectional and Comparative Study

2021 ◽  
Vol 9 ◽  
Author(s):  
Mai Aldhahri ◽  
Rana Alghamdi
Keyword(s):  
Saudi Arabia ◽  
Online Survey ◽  
Control Measures ◽  
Infection Prevention And Control ◽  
Cross Sectional ◽  
Second Stage ◽  
Before And After ◽  
Prevention And Control Measures ◽  
Two Stages ◽  
And Control

Background: Infection prevention and control measures are critical for the prevention of the spread of COVID-19.Aim: In this study, we aimed to measure and evaluate the level of awareness and knowledge of the prevention, symptoms, and transmission control of COVID-19 before and after quarantine among the residents of Rabigh city and adjacent villages in Saudi Arabia.Methods: A cross-sectional online survey was conducted in two stages: the first stage took place before quarantine and the second stage took place after quarantine. The survey was filled out electronically.Results: A total of 448 participants responded and filled out the questionnaires. Females (73.70%) formed the largest number of participants for both stages. The majority of the participants were <30 years old (50.90%) and had a high education level in various sectors and levels (97.1%). It was noticeable that during the first stage, the participants' awareness of COVID-19 symptoms was not very high: 13.62% did not know about the symptoms. However, by the second stage, awareness about symptoms had increased (9.6%).Conclusion: The residents of Rabigh city and the surrounding villages had good levels of knowledge about COVID-19.

scholarly journals Analysis of kinetics of multicomponent, heterogeneous granular mixtures - Laminar and turbulent flow approach

2016 ◽  
Vol 37 (2) ◽  
pp. 161-173 ◽  
Author(s):  
Jolanta B. Królczyk
Keyword(s):  
Granular Materials ◽  
Liquid Mixture ◽  
Industrial Applications ◽  
Fluid Mixtures ◽  
Granular Mixtures ◽  
Laminar And Turbulent Flow ◽  
Two Stages ◽  
First Time ◽  
Kinetics Of

Abstract Mixing of granular materials is unquestionably important. Mixing solids is common in industrial applications and frequently represents a critical stage of the processes. The effect of mixing determines the quality of the products. Achieving a gas or liquid mixture ideally homogeneous in terms of composition in the case of dissolving components is not that difficult, while in case of granular materials that usually differ in sizes and densities, obtaining a homogenous mixture is practically impossible. The aim of the paper is to present the kinetics of mixing of a multicomponent, nonhomogeneous granular mixture. For the first time in mixing of granular materials, a reference has been made to the terminology used in kinematics of fluid mixtures to determine the state of the mixture: turbulent or laminar. By means of statistical analysis the mixing process was divided into two stages. The initial phase of the process was called the stage of turbulent changes, due to large differences in the quality of the observed mixtures; the final step of the process was called the stage of laminar, stable changes, where further mixing did not result in a significant improvement in quality. The research was conducted in industrial conditions in a two-tonne mixer.

Quality of labor epidural analgesia at a high-volume tertiary care obstetric unit: a before-and-after study

2020 ◽  
pp. rapm-2020-101873
Author(s):  
Robert G Easther ◽  
Kristi Downey ◽  
Nancy Watts ◽  
Xiang Y Ye ◽  
Jose C A Carvalho
Keyword(s):  
Rating Scale ◽  
Tertiary Care ◽  
Labor Analgesia ◽  
Continuous Epidural Infusion ◽  
Second Stage Of Labor ◽  
Second Stage ◽  
Before And After ◽  
Labor Epidural ◽  
The Impact

IntroductionWe wanted to better understand the quality of our labor epidural practice at a large urban academic medical center. Several practice changes were implemented between 2011 and 2017, namely a more uniform epidural loading dose of local anesthetic that includes fentanyl, an increase in both the hourly baseline offer and maximum allowed hourly amount of bupivacaine, and the change from a continuous epidural infusion to a programmed intermittent epidural bolus (PIEB) regimen. We aimed to assess the impact of those changes on the quality of labor analgesia.MethodsWe performed two separate audits representing before-and-after groups. The audits were performed in November 2011 (before group) and November–December 2017 (after group). The data for 2011 were extracted from a previously published study. Hence, we conducted a similar audit in 2017, including only outcomes that were included in the previous audit. The primary outcome was the presence of pain >3 (Numerical Rating Scale 0–10) at any time during first or second stage of labor. Secondary outcomes included top-up requirements, and women’s pain perception during the first and second stage of labor according to a postpartum questionnaire.ResultsWe studied 294 and 247 women in the before-and-after groups, respectively. The proportion of women reporting pain >3/10 at any time during labor and delivery significantly decreased in the after group (30% vs 41%; p<0.01). In an adjusted analysis, there was a 35% reduction in the likelihood of pain scores>3 for the after group (OR 0.65, 95% CI 0.46, 0.94). Women in the after group received fewer top-ups by nurses (3% vs 24%, p<0.001). Most women in both cohorts (85% before and 87% after) were satisfied with the overall quality of analgesia.DiscussionA bundle of practice changes implemented in our clinical practice, including the PIEB regimen, has resulted in a significant improvement in the quality of labor analgesia. However, despite all the implemented changes, 30% of women still experience pain during labor and further optimization of our practice is warranted.

Kinetics of Mixed Low-Level Waste Incapsulation Using Iron Phosphate Chemically Bonded Cement

2006 ◽  
Vol 932 ◽  
Author(s):  
A.S. Aloy ◽  
T.I. Koltsova ◽  
E.N. Kovarskaya ◽  
M.Yu. Silin
Keyword(s):  
Formation Process ◽  
Iron Phosphate ◽  
Structural Formation ◽  
Low Level ◽  
Second Stage ◽  
Bivalent Iron ◽  
Acid Reaction ◽  
The Moment ◽  
Two Stages ◽  
Kinetics Of

ABSTRACTThe iron phosphate cement (IPC) structure formation process has been studied by Mossbauer spectroscopy. The IPC is formed as a result of interaction of iron oxides with orthophosphoric acid and could be used as a matrix for immobilization of low-level radioactive waste.The structural formation process has been shown may be considered to consist of two stages. The first stage lasts to the moment of setting, when the diffusion process goes on in the liquid phase. At this stage the main fragments of the structural polymeric frame of the IPC are developed consisting of iron (+2) and (+3) phosphates. The rate of the oxides-with-phosphoric-acid reaction as well as the time of hardening depends on the bivalent iron content.The second stage begins from the moment of setting when the diffusion becomes slower. At this stage the process is characterized by the negligible increase in the iron phosphates (+2), (+3) content and transformation of the previously formed phosphates.The nuclear gamma-resonance (NGR) parameters have been determined of FeH3(PO4)2·2.5H2O, forming in the hematite (Fe2O3) based IPC: isomeric shift (IS) = 0.46 mm/s, quadrupole splitting (QS) = 0.197 mm/s, FWHM =0.282 mm/s.

Oxidation Kinetics of the Sintered Iron Parts Steam Treated in an Industrial Continuous Furnace

2010 ◽  
Vol 660-661 ◽  
pp. 243-248
Author(s):  
Eduardo Nunes ◽  
Ivan Gilberto Sandoval Falleiros
Keyword(s):  
Oxidation Kinetics ◽  
Continuous Furnace ◽  
Steam Treatment ◽  
Sintered Iron ◽  
Second Stage ◽  
Parabolic Law ◽  
Controlling Mechanism ◽  
Iron Diffusion ◽  
Two Stages ◽  
Kinetics Of

It has been studied a steam treatment process in an industrial continuous furnace for sintered iron parts in a temperature range varying from 490 to 570 °C and sample´s sintered densities of 6,52 and 6,77 g / cm3 . The tests have showed oxidation kinetics with two stages, each of them obeying a parabolic law. The first stage was faster than the second. The oxidation time when the oxidation kinetics of the first stage has changed for the second stage showed off very sensitive to the process temperature and sintered densities of the parts which are in agreement with the process rate controlling mechanism that was found to be the iron diffusion through the oxide layer.

scholarly journals Madrasah Principal Leadership Role in Improving Teachers’ Performance

2021 ◽  
Vol 1 (1) ◽  
pp. 10
Author(s):  
Sarmi Sinta Putri ◽  
Safri Mardison
Keyword(s):  
Principal Leadership ◽  
Program Planning ◽  
Preliminary Observation ◽  
Leadership Role ◽  
Data Display ◽  
Learning Program ◽  
Second Stage ◽  
Two Stages

This study aims to describe the role of the madrasah principal in improving teachers’ performance. This was a descriptive qualitative study. Observation, interviews, and documentation were used to collect the data. The source of data were the principal and teachers of MTsN 4 Muko-muko. Data were analyzed in two stages: the first stage was preliminary observation and the second stage was the research which included three steps, namely data reduction, data display, and data verification. Trustworthiness data were tested by conducting triangulation. The result indicated that principal leadership in improving the quality of teachers’ performance included Discipline Development Supervision Program (PPD), Supervision and Evaluation (SDE) activity, and Learning Program Planning. These findings are the basic of how discipline, supervision, and learning program planning become the indicators of guidance to improve the quality of teachers’ performance.    

scholarly journals PENGGUNAAN KARTU KUARTET UNTUK MENINGKATKAN PEMAHAMAN KEBERAGAMAN SENI TRADISI NUSANTARA PADA SISWA SEKOLAH DASAR

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Karsono ◽  
Yudianto Sujana ◽  
Joko Daryanto ◽  
Ngadino Yustinus
Keyword(s):  
Elementary School ◽  
Learning Process ◽  
Research Approach ◽  
Traditional Art ◽  
Is Implementation ◽  
Second Stage ◽  
Action Research Approach ◽  
Two Stages ◽  
Traditional Arts

<p>The purpose of this research is to improve the quality of the learning process subjects Culture Art and Skills in elementary school, especially in understanding of the diversity of Indonesian traditional art. This research was conducted in two stages. First, to develop a media card quartet, and second stage is implementation of the themed quartet card into the learning process in the classroom. Research methods use classroom action research approach because the quartet card media was subsequently used in the learning process in the classroom to improve understanding. Source of data collected by conducting interviews, tests, observations, and documentation. The analysis of the data using Miles and Hubberman’s interactive model, includes the step of data reduction, data display, and conclusion. The results showed that the use of card-themed quartet can enhance students' understanding of elementary school SDN 01 Jatisawit and SDN Dilem in the diversity of Indonesian traditional art material. Keywords: instructional media, cards quartet, the diversity of traditional arts.</p><p>Penelitian ini hendak memperbaiki kualitas proses pembelajaran mata pelajaran Seni Budaya dan Keterampilan (SBK) di sekolah dasar (SD) dalam aspek pemahaman peserta didik akan materi pembelajaran keragaman seni tradisi nusantara. Secara garis besar penelitian ini dilakukan dalam dua tahapan. Tahapan pertama melakukan pengembangan media kartu kuartet, dan tahapan kedua yaitu tahap implementasi kartu kuartet bertema budaya nusantara tersebut ke dalam proses pembelajaran di kelas. Metode penelitian menggunakan pendekatan penelitian tindakan kelas karena media kartu kuartet yang dibuat selanjutnya digunakan dalam proses pembelajaran di kelas untuk meningkatkan pemahaman materi keragaman seni tradisi. Sumber data dikumpulkan dengan melakukan wawancara, tes, observasi, dan dokumentasi. Sedangkan analisis data menggunakan model analisis interaktif dari Miles dan Huberman meliputi tahap reduksi data, penyajian data, dan penarikan kesimpulan. Hasil penelitian<br />memperlihatkan bahwa penggunaan kartu kuartet bertema seni tardisi nusantara dapat meningkatkan pemahaman siswa sekolah dasar SDN 01 Jatisawit dan SDN Dilem, dalam materi keberagaman seni tradisi nusantara.</p>

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