Detailed mechanisms of hydrogen charging and hydrogen stress cracking of steel in liquid ammonia storage

2019 ◽  
Vol 107 (4) ◽  
pp. 402 ◽  
Author(s):  
Jean-Louis Crolet
Keyword(s):  
Corrosion Potential ◽  
Capital Expenditures ◽  
Test Results ◽  
Redox Equilibrium ◽  
Exposure Test ◽  
Free Corrosion Potential ◽  
Hydrogen Charging ◽  
Stress Cracking ◽  
High Potentials ◽  
The One

The available polarisation curves of the literature are analysed in view of the theoretical analysis of the corrosive medium in Part I (J.-L. Crolet, Matériaux & Techniques 107, 401, 2019) and the new views on passivation and hydrogen charging. The accurate electrochemical conditions of the respective cathodic and “anodic” hydrogen charging are thus defined, or more exactly the paradox of a protonic cathodic reaction only running at high potential. Similarly in the available exposure test results, the locus of the ternary redox equilibrium between ammonia and its two decisive contaminants, oxygen and water, separates contaminated ammonia into two domains, on the one hand, a safe domain where the undersaturated oxygen cannot act as an oxidiser, hence no anodic HSC at the free corrosion potential, and on the other hand, a dangerous domain where oxygen is supersaturated, hence oxidising conditions, steel passivation, high potentials, anodic charging and anodic HSC. Likewise, all the known features of this environmental cracking are also explained, with no exception nor contradiction, including the differences between the liquid and vapour phases. An experimental method is also proposed to directly check the occurrence of anodic charging, and proposals are also made for at the same time improving safety and reducing operational or capital expenditures.

EVALUASI ANR PADA TRANSMISI DATA NETWORK TERHADAP WP-REST API DALAM APLIKASI ANDROID

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Agung Riyadi
Keyword(s):  
Large Data ◽  
Data Retrieval ◽  
Test Results ◽  
Android Application ◽  
Retrieval Process ◽  
Request Queue ◽  
Plant Data ◽  
Android Development ◽  
Rest Api ◽  
The One

The One of many way to connect to the database through the android application is using volleyball and RESTAPI. By using RestAPI, the android application does not directly connect to the database but there is an intermediary in the form of an API. In android development, Android-volley has the disadvantage of making requests from large and large data, so an evaluation is needed to test the capabilities of the Android volley. This research was conducted to test android-volley to retrieve data through RESTAPI presented in the form of an application to retrieve medicinal plant data. From the test results can be used by volley an error occurs when the back button is pressed, in this case another process is carried out if the previous volley has not been loaded. This error occurred on several android versions such as lollipops and marshmallows also on some brands of devices. So that in using android-volley developer need to check the request queue process that is carried out by the user, if the data retrieval process by volley has not been completed, it is necessary to stop the process to download data using volley so that there is no Android Not Responding (ANR) error.Keywords: Android, Volley, WP REST API, ANR Error

Experimental Study of Propagation Stage of Pitting Corrosion of 20Cr13 Steel

2008 ◽  
Vol 38 ◽  
pp. 238-247
Author(s):  
A.D. Davydov ◽  
V.S. Shaldaev
Keyword(s):  
Pitting Corrosion ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Ph Value ◽  
Open Circuit ◽  
Effect Of Temperature ◽  
Pitting Potential ◽  
Free Corrosion Potential ◽  
External Power Source ◽  
Corrosion Of Steel

The initiation and development of pitting corrosion of steel 20Cr13 in the NaCl solutions with various concentrations, temperatures, and pH values are studied under the potentiostatic conditions and at the free-corrosion potential. The pitting and repassivation potentials are determined using the method of cycling voltammetry. In spite of the fact that thus determined pitting potential is more positive than the corrosion potential (the open-circuit potential Eo.c.), the long-term experiments, which were performed at the free-corrosion potential, showed that pitting corrosion takes place without imposing a potential using an external power source. It is concluded that the probability of pitting corrosion of steel should be determined by comparing the corrosion potential (the open-circuit potential) with the repassivation potential Erp. Steel 20Cr13 is prone to the pitting corrosion, because Erp is more negative than Eo.c.. In the potentiostatic experiments, the variation of the depth and diameter of pits and their number with the time and the effect of temperature and electrode rotation on the pit propagation are studied. The results, which were obtained at the free-corrosion potential, are much less reproducible. In this case, in contrast to the potentiostatic conditions, the pit depth increased only slightly and the pit width increased to a larger extent. The effect of concentration, pH value, and temperature of NaCl solutions on the pit propagation is considered. It is concluded that the data on the development of pitting corrosion under the potentiostatic conditions can be hardly extended to the conditions of free corrosion potential.

scholarly journals Performance Variance  Evaluation on  Mozilla Firefox

2021 ◽  
Author(s):  
◽  
Jan Larres
Keyword(s):  
Statistical Technique ◽  
External Factors ◽  
Software Performance ◽  
Performance Tests ◽  
Test Results ◽  
Actual Performance ◽  
Reliable Detection ◽  
Mozilla Firefox ◽  
The One ◽  
Test Result

<p>In order to evaluate software performance and find regressions, many developers use automated performance tests. However, the test results often contain a certain amount of noise that is not caused by actual performance changes in the programs. They are instead caused by external factors like operating system decisions or unexpected non-determinisms inside the programs. This makes interpreting the test results hard since results that differ from previous results cannot easily be attributed to either genuine changes or noise. In this thesis we use Mozilla Firefox as an example to try to find the causes for this performance variance, develop ways to reduce the noise and present a statistical technique that makes identifying genuine performance changes more reliable. Our results show that a significant amount of noise is caused by memory randomization and other external factors, that there is variance in Firefox internals that does not seem to be correlated with test result variance, and that our suggested statistical forecasting technique can give more reliable detection of genuine performance changes than the one currently in use by Mozilla.</p>

scholarly journals PENGARUH LATIHAN SMALL SIDE GAME TERHADAP KETERAMPILAN PASSING SISWA SMP PLUS NURUL HUDA DALAM EKSTRAKURIKULER SEPAK BOLA TAHUN AJARAN 2020

2020 ◽  
Vol 6 (2) ◽  
pp. 137-145
Author(s):  
Lukmanul Hakim
Keyword(s):  
Standard Deviation ◽  
Extracurricular Activities ◽  
Soccer Players ◽  
Test Results ◽  
Purposive Sampling ◽  
Average Value ◽  
The One ◽  
Academic Year ◽  
Small Side

Abstrak: Ketepatan umpan (passing) merupakan salah satu hal yang sangat penting dalam permainan sepak bola. Banyak metode ataupun cara yang bisa dilakukan untuk melatih dan mengasah kemampuan seseorang untuk meningkatkan kualitas passing pada pemain sepak bola. Penelitian ini memiliki tujuan untuk mengetahui pengaruh latihan small side game terhadap keterampilan passing siswa SMP Plus Nurul Huda dalam ekstrakurikuler sepak bola tahun ajaran 2020. Penelitian ini merupakan penelitian eksperimen dengan menggunakan desain One-Group Pretest-posttest Design.Populasi pada penelitian ini adalah siswa ekstrakurikuler sepak bola.Sampel yang digunakan yaitu purposive sampling, dengan syarat bahwa subjek yang digunakan adalah siswa SMP Plus Nurul Huda kelas VII dan VIII yang mengikuti kegiatan ekstrakurikuler. Jumlah sampel pada penelitian ini berjumlah 16 orang.Hasil penelitian menunjukan pada nilai rata-rata yang diperoleh ketika melakukan tes awal adalah 17,38 dengan simpangan baku 1,82. Sedangkan untuk nilai tes akhir adalah rata-rata 25,94 dengan simpangan baku 1,87. Hasil uji-t memperoleh nilai t-hitung > t-tabel(20,990 > 2,13), maka Ho di tolak dan Ha diterima. Dengan demikian dapat disimpulkan bahwa terdapat pengaruh latihan small side game terhadap keterampilan passing siswa SMP Plus Nurul Huda dalam ekstrakurikuler sepak bola tahun ajaran 2020. Kata kunci :small side game, passing   Abstract: The accuracy of the pass (passing) is one of the most important things in soccer. There are many methods or ways that can be done to train and hone one's skills to improve the quality of passing on soccer players. This study aims to determine the effect of small side game training on the passing skills of SMP Plus Nurul Huda students in soccer extracurricular activities for the 2020 academic year.This research is an experimental study using the One-Group Pretest-posttest Design. The population in this study were soccer extracurricular students. The sample used was purposive sampling, with the condition that the subjects used were students of SMP Plus Nurul Huda class VII and VIII who participated in extracurricular activities. The number of samples in this study amounted to 16 people.The results showed that the average value obtained when conducting the initial test was 17.38 with a standard deviation of 1.82. As for the final test score is an average of 25.94 with a standard deviation of 1.87. The t-test results obtained the value of t-count> t-table (20.990> 2.13), then Ho was rejected and Ha was accepted. Thus it can be concluded that there is an effect of small side game training on the passing skills of SMP Plus Nurul Huda students in the football extracurricular activities for the 2020 academic year. Key words: small side game, passing

Hot Corrosion of Nimonic 105 in Sodium Sulfate-Sodium Chloride Melts

CORROSION ◽  
1981 ◽  
Vol 37 (7) ◽  
pp. 392-407 ◽  
Author(s):  
C. A. C. Sequeira ◽  
M. G. Hocking
Keyword(s):  
Sodium Chloride ◽  
Corrosion Behavior ◽  
Analytical Methods ◽  
Sodium Sulfate ◽  
Hot Corrosion ◽  
Corrosion Potential ◽  
Free Corrosion Potential ◽  
Chloride Melts ◽  
Ni Alloy ◽  
Potential Decay

Abstract The corrosion behavior of Nimonic 105 in molten Na2SO4, NaCl, and mixtures of these two salts, at 900 C, in laboratory air and under O2 + SO2/SO3 atmospheres has been evaluated by potentiodynamic, potential decay, and free corrosion potential measurements. In addition, the corrosion products were examined using several electron-optical techniques, and by other analytical methods. Pure Na2SO4 in air did not seem to be very corrosive towards Nimonic 105. Addition of NaCl to the molten Na2SO4 resulted in increased dissolution of Nimonic 105, which was in general nonuniform, alloy constituents nickel and cobalt dissolving more than others. Evidence of internal attack and enhancement of dissolution of the Ni alloy by SO3 was significant only when the corrosion conditions were prolonged. In pure NaCl, catastrophic corrosion occurs, which has been attributed to the depletion, dissolution, and vaporization of some alloy species.

The Fatigue Performance of High Performance Concrete Composite Girder

2019 ◽  
Author(s):  
C. Xu ◽  
B. Y. Zhang ◽  
Z. H. Hou
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Test Results ◽  
Normal Concrete ◽  
Bending Tests ◽  
Composite Girder ◽  
Tensile Performance ◽  
Negative Bending ◽  
The One ◽  
Push Out

<p>The application of high performance concrete has been increasingly concerned in the negative flexural region of steel‐concrete continuous composite girder because of its favorable tensile performance. However, the unclear cyclic and ultimate performance of a high performance concrete composite girder results to the problems which hinder the further application. In this case, a series of fatigue negative bending tests on HPC composite girders and fatigue push‐out tests on stud connectors in HPC were executed. The test results showed that the fatigue slip in the HPC composite girder was smaller than the normal concrete composite girder, and the fatigue life of stud in HPC was longer than the one in normal concrete. Meanwhile, according to the comparison between the stud fatigue live evaluations and test results, the AASHTO‐based evaluations were comparatively with larger safety redundancy, and JSCE was close to the test results but had smaller safety redundancy.</p>

Reference intervals for calcium, phosphate, and alkaline phosphatase as derived on the basis of multichannel-analyzer profiles.

1986 ◽  
Vol 32 (1) ◽  
pp. 76-79 ◽  
Author(s):  
T J Sinton ◽  
D M Cowley ◽  
S J Bryant
Keyword(s):  
Alkaline Phosphatase ◽  
Calcium Phosphate ◽  
Older Patients ◽  
Reference Intervals ◽  
Plasma Calcium ◽  
Test Results ◽  
Abrupt Increase ◽  
Multichannel Analyzer ◽  
The Mean ◽  
The One

Abstract In an attempt to demonstrate a rapid and economical approach to deriving reference intervals, we analyzed data on plasma calcium and phosphate from a multichannel analyzer for more than 20 000 subjects and data on alkaline phosphatase from more than 10 000 subjects. Subjects were selected by the criterion, that their results for constituents other than the one of interest were within current reference intervals. Thus we have been able to include older patients who have diseases that accompany old age, but that do not affect test results. The mean concentrations of calcium and phosphate decreased with increasing age in both sexes, except for an abrupt increase for women about the time of reaching menopause. Similarly, the mean alkaline phosphatase activity increased with age in both sexes, reflecting a skewed frequency distribution. Here also, there was an abrupt increase in the modal value for women near menopause.

scholarly journals INVESTIGATION INTO U.S. OUTDOOR EXPOSURE TEST SITES AND EXPOSURE TEST RESULTS IN MIYAKO ISLAND, JPN AND SOUTH FLORIDA, U.S.

2017 ◽  
Vol 23 (54) ◽  
pp. 391-396
Author(s):  
Teruo KONDO ◽  
Makoto SUZUKI ◽  
Akira KONDO ◽  
Yoshimitsu GOTO ◽  
Nobuyuki SATO
Keyword(s):  
Outdoor Exposure ◽  
South Florida ◽  
Test Results ◽  
Exposure Test ◽  
Outdoor Exposure Test

Effects of Mechanical Preloads on the Rotordynamic Performance of a Rotor Supported on Three-Pad Gas Foil Journal Bearings

2014 ◽  
Vol 136 (12) ◽  
Author(s):  
Kyuho Sim ◽  
Bonjin Koo ◽  
Jong Sung Lee ◽  
Tae Ho Kim
Keyword(s):  
Test Data ◽  
High Speed ◽  
Experimental Tests ◽  
Journal Bearings ◽  
Test Results ◽  
Performance Measurements ◽  
Displacement Sensors ◽  
Single Top ◽  
Speed Up ◽  
The One

This paper presents the rotordynamic performance measurements and model predictions of a rotor supported on three-pad gas foil journal bearings (GFJBs) with various mechanical preloads. The rotor with its length of 240 mm, diameter of 40 mm, and weight of 19.6 N is supported on two GFJBs and one pair of gas foil thrust bearings (GFTBs), being a permanent magnet rotor of a high speed electric motor. Each bearing pad consisting of a top foil and a bump-strip layer is installed on a lobed bearing housing surface over the arc length of 120 deg along the circumference. Test three-pad GFJBs have four different mechanical preloads, i.e., 0 μm, 50 μm, 70 μm, 100 μm with a common radial nominal clearance of 150 μm. A series of speed-up tests are conducted up to 93 krpm to evaluate the effects of increasing mechanical preloads on the rotordynamic performance. Two sets of orthogonally positioned displacement sensors record the rotor horizontal and vertical motions at the thrust collar and the other end. Test results show that the filtered synchronous amplitudes change little, but the onset speed of subsynchronous motions (OSS) increases dramatically for the increasing mechanical preloads. In addition, test bearings with the 100 μm preload show a higher OSS in load-on-pad (LOP) condition than that in load-between-pads (LBP) condition. A comparison with test results for a one-pad GFJB with a single top foil and bump-strip layer reveals that three-pad GFJB has superior rotordynamic performance to the one-pad one. Finally, the test data benchmark against linear rotordynamic predictions to validate a rotor-GFJB model. In general, predicted natural frequencies of the rotor-bearing system and synchronous rotor motions agree well with test data. However, stability analyses underestimate OSSs recorded during the experimental tests.

Sign in / Sign up

Export Citation Format

Share Document