scholarly journals Strength Recovery Model of Clay during Thixotropy

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Bin Tang ◽  
Biaohe Zhou ◽  
Liang Xie ◽  
Jianfeng Yin ◽  
Shengnan Zhao ◽  
...  
Keyword(s):  
Moisture Content ◽  
Test Data ◽  
Great Influence ◽  
Test Results ◽  
Underground Structures ◽  
Recovery Model ◽  
Stability Calculation ◽  
Strength Recovery ◽  
Compressive Strength Test ◽  
Soil Sensitivity

Thixotropy is a hot topic in the field of rheology of dispersed systems. Many researchers have proposed different models and hypotheses to explain the thixotropy of clay. In this paper, the strength recovery model of Zhanjiang Formation clay in the process of thixotropy is studied. Firstly, through unconfined compressive strength test, the influence of soil sensitivity, moisture content, and density on the strength growth of remolded soil was studied. The results show great influence of sensitivity, moisture content, and density on the thixotropic strength of the Zhanjiang Formation clay: the higher the sensitivity and the density, the stronger the thixotropy of soil; the higher the moisture content, the weaker the thixotropy of soil. Based on the test results, a strength recovery model of Zhanjiang Formation clay in the process of thixotropy was established. The model was verified by the validation test data and the data obtained from the existing literature. The results suggest that the model prediction is in good agreement with the verification test data and data from existing literature, which proves the confidence of the model in predicting the degree of strength recovery in the process of thixotropy of Zhanjiang Formation clay. The model provides basis for stability calculation of surrounding soil after construction disturbance of underground structures in this stratum.

Pemberian Umpan Balik Dalam Meningkatkan Hasil Belajar dan Minat Belajar Mahasiswa

2015 ◽  
Vol 4 (3) ◽  
Author(s):  
Seruni Seruni ◽  
Nurul Hikmah
Keyword(s):  
Information Technology ◽  
Learning Outcomes ◽  
Test Data ◽  
Random Sampling ◽  
Covariance Matrices ◽  
Test Results ◽  
Immediate Feedback ◽  
Statistics Course ◽  
Independent Variable ◽  
Descriptive Statistical Analysis

<p>The purpose of this study is to find and analyze the effect of feedback on <br />learning outcomes in mathematics and an interest in basic statistics course. The <br />population in this study are affordable Information Technology Student cademic Year 2012/2013 Semester II Indraprasta PGRI University of South Jakarta. Sample The study sample was obtained through random sampling. This study used an experimental method to the analysis using the MANOVA test. This study has three variables, consisting of: one independent variable, namely the provision of feedback (immediate and delayed), and two dependent variable is the result of interest in the study of mathematics and basic statistics course. The data was collected for the test results to learn mathematics, and a questionnaire for the interest in basic statistics course. Collected data were analyzed using the MANOVA test. Before the data were analyzed, first performed descriptive statistical analysis and test data analysis requirements (test data normality and homogeneity of covariance matrices). The results show that the learning outcomes of interest in mathematics and basic statistics course for students who are given immediate feedback higher than students given feedback delayed. <br /><br /></p>

Medium Density Particleboard with Addition of Impregnated Paper

2014 ◽  
Vol 1025-1026 ◽  
pp. 543-546
Author(s):  
Juliana Cortez Barbosa ◽  
Anderson Luiz da Silva Michelon ◽  
Elen Aparecida Martines Morales ◽  
Cristiane Inácio de Campos ◽  
André Luis Christoforo ◽  
...  
Keyword(s):  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Mechanical Tests ◽  
Modulus Of Rupture ◽  
Medium Density ◽  
Test Results ◽  
Thickness Swelling ◽  
Adhesion Test ◽  
Layer Medium ◽  
Determine Moisture Content

The aim of this research was to produce three-layer Medium Density Particleboard (MDP), with the addition of impregnated paper, in the inner layer, in proportions of 1; 5 and 20%. In this study, MDP was composed with particles of small size in outer layers, and larger particles in internal layer. After panel manufacturing, physical and mechanical tests based on Brazilian Code ABNT NBR 14.810 were carried out to determine moisture content; density; thickness swelling; water absorption; modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending and internal adhesion. Test results were compared to commercial panels, produced with 100% Eucalyptus, considering the requirements specified by Brazilian Code. Properties presented values close to normative specifications, indicating positively the possibility of production of MDP using addition of waste paper impregnated.

Measurements of Rotordynamic Coefficients of Hybrid Bearings With (a) a Plugged Orifice, and (b) a Worn Land Surface

2002 ◽  
Vol 124 (2) ◽  
pp. 363-368 ◽  
Author(s):  
F. Laurant ◽  
D. W. Childs
Keyword(s):  
Test Data ◽  
Land Surface ◽  
Rocket Engine ◽  
Liquid Rocket Engine ◽  
Test Results ◽  
Rotordynamic Coefficients ◽  
Hybrid Bearing ◽  
Liquid Rocket

Test results are presented for the rotordynamic coefficients of a hybrid bearing that is representative of bearings for liquid-rocket-engine turbopump applications. The bearing is tested in the following two degraded conditions: (a) one of five orifices plugged, and (b) a locally enlarged clearance to simulate a worn condition. Test data are presented at 24,600 rpm, with supply pressures of 4.0, 5.5, and 7.0 MPa, and eccentricity ratios from 0.1 to 0.5 in 0.1 increments. Overall, the results suggest that neither a single plugged orifice nor significant wear on the bearing land will “disable” a well-designed hybrid bearing. These results do not speak to multiple plugged orifices and are not an endorsement for operations without filters to prevent plugging orifices.

MENINGKATKAN KETERAMPILAN MENULIS PUISI MELALUI MEDIA TULISAN BERGAMBAR (MEME) DI INSTAGRAM PADA PESERTA DIDIK KELAS VIII G SMPN 24 SURABAYA

Buana Bastra ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 26-31
Author(s):  
Prily Yulia Utomo Putri ◽  
Tri Indrayanti
Keyword(s):  
Data Analysis ◽  
Data Collection ◽  
Test Data ◽  
Writing Skills ◽  
Test Results ◽  
Population Activity ◽  
Data Analysis Technique ◽  
Analysis Technique ◽  
Class Viii

This research is a research follow class by using the secound cycle that there is the first cycle and cycle II. On the cycle I and cycle II each cycle there four stage of the (1) planning, (2) implementation of action, (3) observations, and (4) reflection. Each cycle has two meetings in one week, namely the first meeting and the second meeting with the allocation 2 x 40 minutes of each meeting. Subject in research is learners class VIII G SMPN 24 Surabaya totaling 37 learners contained 16 learners men and 21 learners woman. This school is located in Jl. Kebraon Indah Permai Blok K/23 A Surabaya. Data collection techniques to use the observation and test, data analysis technique using the percentage of. Based on the results of data analysis, it can be concluded that using pictorial writing media on the meme on Instagram can improve the writing skills of class students VIII G SMPN 24 Surabaya. This can be seen from (1) population activity in the cycle I 84,61% on the cycle II 100%, (2) activity learners in cycle I 83,44% on the cycle II 90,20%, (3) the test results writing skills poerty in cycle I 56,73% one the cycle of II increased 83,70%.

Experiment and Optimization of High-Efficiency Mechanical Separation of Peanut Seedlings and Residual Film Based on Suspension Velocity

2021 ◽  
Vol 64 (4) ◽  
pp. 1381-1389
Author(s):  
Fengwei Gu ◽  
Meng Yang ◽  
Zhichao Hu ◽  
Yanhua Zhang ◽  
Chong Zhang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Rotational Speed ◽  
Loss Rate ◽  
Removal Rate ◽  
Performance Tests ◽  
Test Results ◽  
Material Loss ◽  
Validation Test ◽  
Residual Film ◽  
Forage Utilization

HighlightsAn efficient method for separating peanut seedlings and residual film harvested from film-mulched peanut was proposed, and the mechanism was optimized.The relationships between the suspension velocity and moisture content of different shredded materials were studied.Four-factor, three-level Box-Behnken experiments were carried out and analyzed, and the optimal parameter combination was determined.A validation test was carried out to verify the rationality and accuracy of the optimized regression model.Abstract. To address the problems of lower residual film removal and higher material loss in the forage utilization of peanut seedlings wrapped in residual film, this study explored the relationships between the suspension velocity and moisture content of different shredded materials derived from peanut seedlings and conducted performance tests and parameter optimization for a machine that uses peanut seedlings as forage material. Four-factor, three-level Box-Behnken experiments were designed using the rotational speeds of the shredding shaft, upper fans, and lower fans and the frequency of the vibrating sieve as test factors, and using the residual film removal rate and material loss rate as response values. The test results indicated that the suspension velocity of the shredded materials showed a quadratic relationship with moisture content. The performance tests showed that the significance sequence of the test factors for the residual film removal rate was: rotational speed of the lower fans, rotational speed of the upper fans, rotational speed of the shredding shaft, and frequency of the vibrating sieve. The significance sequence for the material loss rate was: rotational speed of the lower fans, rotational speed of the shredding shaft, frequency of the vibrating sieve, and rotational speed of the upper fans. The parameter optimization and validation test showed that the residual film removal rate was 92.71% and the material loss rate was 8.19% when the rotational speeds of the shredding shaft, upper fans, and lower fans were 1650, 770, and 665 rpm, respectively, and the frequency of the vibrating sieve was 4 Hz. The relative errors between the validation test results and the predicted values from the regression models were less than 3%, which suggests that the regression models are reliable. This study provides a reference for the forage utilization of peanut seedlings harvested from film-mulched peanut and provides a reference for determining the optimal working parameters of forage processing machines. Keywords: Agricultural machinery, Box-Behnken experiment, Optimization, Peanut film-seedling separation, Suspension velocity.

Durability of BFRP and Hybrid FRP Sheets under Freeze-Thaw Cycling

2010 ◽  
Vol 163-167 ◽  
pp. 3297-3300 ◽  
Author(s):  
Jia Wei Shi ◽  
Hong Zhu ◽  
Zhi Shen Wu ◽  
Gang Wu
Keyword(s):  
Mechanical Properties ◽  
Test Data ◽  
Mechanical Characteristics ◽  
Test Results ◽  
Freeze Thaw ◽  
Frp Composites ◽  
Test Parameters ◽  
The Stability ◽  
Better Than

Coupon tests were conducted to investigate the mechanical characteristics of basalt FRP (BFRP) sheet, basalt-carbon hybrid FRP sheets and the corresponding epoxy rein under the effect of freeze-thaw cycling. FRP sheets and epoxy rein coupons were subjected to up to 200 and 250 freeze-thaw cycles respectively. Test parameters included the number of freeze-thaw cycles and the types of FRP composites. Test results show that (1) BFRP sheet perform better than CFRP or GFRP sheets under high freeze-thaw cycles; (2) exposed hybrid FRP sheets not only show very little loss in mechanical properties, but also contribute to the stability of test data; (3) mechanical properties of rein epoxy decrease significantly with increasing freeze-thaw cycles.

Leakage, Drag Power and Rotordynamic Force Coefficients of an Air in Oil (Wet) Annular Seal

2017 ◽  
Author(s):  
Luis San Andrés ◽  
Xueliang Lu
Keyword(s):  
Test Data ◽  
Volume Fraction ◽  
Damping Coefficient ◽  
Liquid Volume ◽  
Pure Liquid ◽  
Test Results ◽  
Liquid Volume Fraction ◽  
Force Coefficients ◽  
Damping Coefficients ◽  
Annular Seal

Wet gas compression systems and multiphase pumps are enabling technologies for the deep sea oil and gas industry. This extreme environment determines both machine types have to handle mixtures with a gas in liquid volume fraction (GVF) varying over a wide range (0 to 1). The gas (or liquid) content affects the system pumping (or compression) efficiency and reliability, and places a penalty in leakage and rotordynamic performance in secondary flow components, namely seals. In 2015, tests were conducted with a short length smooth surface annular seal (L/D = 0.36, radial clearance = 0.127 mm) operating with an oil in air mixture whose liquid volume fraction (LVF) varied to 4%. The test results with a stationary journal show the dramatic effect of a few droplets of liquid on the production of large damping coefficients. This paper presents further measurements and predictions of leakage, drag power, and rotordynamic force coefficients conducted with the same test seal and a rotating journal. The seal is supplied with a mixture (air in ISO VG 10 oil), varying from a pure liquid to an inlet GVF = 0.9 (mostly gas), a typical range in multiphase pumps. For operation with a supply pressure (Ps) up to 3.5 bar (a), discharge pressure (Pa) = 1 bar (a), and various shaft speed (Ω) to 3.5 krpm (ΩR = 23.3 m/s), the flow is laminar with either a pure oil or a mixture. As the inlet GVF increases to 0.9 the mass flow rate and drag power decrease monotonically by 25% and 85% when compared to the pure liquid case, respectively. For operation with Ps = 2.5 bar (a) and Ω to 3.5 krpm, dynamic load tests with frequency 0 < ω < 110 Hz are conducted to procure rotordynamic force coefficients. A direct stiffness (K), an added mass (M) and a viscous damping coefficient (C) represent well the seal lubricated with a pure oil. For tests with a mixture (GVFmax = 0.9), the seal dynamic complex stiffness Re(H) increases with whirl frequency (ω); that is, Re(H) differs from (K-ω2M). Both the seal cross coupled stiffnesses (KXY and −KYX) and direct damping coefficients (CXX and CYY) decrease by approximately 75% as the inlet GVF increases to 0.9. The finding reveals that the frequency at which the effective damping coefficient (CXXeff = CXX-KXY/ω) changes from negative to positive (i.e., a crossover frequency) drops from 50% of the rotor speed (ω = 1/2 Ω) for a seal with pure oil to a lesser magnitude for operation with a mixture. Predictions for leakage and drag power based on a homogeneous bulk flow model match well the test data for operation with inlet GVF up to 0.9. Predicted force coefficients correlate well with the test data for mixtures with GVF up to 0.6. For a mixture with a larger GVF, the model under predicts the direct damping coefficients by as much as 40%. The tests also reveal the appearance of a self-excited seal motion with a low frequency; its amplitude and broad band frequency (centered at around ∼12 Hz) persist and increase as the gas content in the mixture increase. The test results show that an accurate quantification of wet seals dynamic force response is necessary for the design of robust subsea flow assurance systems.

scholarly journals Analysis of The Rock Fracture on Uniaxial Compressive Strength Test

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Edward Dinoy ◽  
Yohanes Gilbert Tampaty ◽  
Imelda Srilestari Mabuat ◽  
Joseph Alexon Sutiray Dwene
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Poisson Ratio ◽  
Rock Fracture ◽  
Strength Test ◽  
Maximum Pressure ◽  
Test Results ◽  
Average Value ◽  
Compressive Strength Test ◽  
Uniaxial Compressive Strength Test

The compressive strength test is one of the technical properties or compressive strength tests that are commonly used in rock mechanics to determine the collapse point or the elasticity of rock against maximum pressure. The rock collapse point is a measure of the strength of the rock itself when the rock is no longer able to maintain its elastic properties. The purpose of this test is to find out how long the rock maintains its strength or elasticity properties when pressure is applied, and to find out the difference between the strength of compact rock and rock that has fractures when pressure is applied. Rocks that have fractures will break more easily or quickly when pressure is applied compared to compact rocks. This analysis is carried out by comparing the rock strength of each sample, both those that have fractures and compact rocks. To find out these differences, laboratory testing was carried out. The test results show the value (compressive strength test 57.76 MPa), (elastic modulus 5250.000MPa), (Poisson ratio 0.05) and the average value of rock mechanical properties test (axial 0.91), (lateral-0.279), and (volumetric 0.252) . Based on the test results above, it shows that rocks that have fractures will break more easily when pressure is applied, compared to compact rocks that have a long time in the uniaxial compressive strength test.

scholarly journals Load characteristics of three-plunger pumps for spray seawater fire-fighting

2020 ◽  
pp. 142-146
Author(s):  
В.А. Наумов ◽  
Н.Л. Великанов ◽  
А.В. Тришина
Keyword(s):  
Satisfactory Agreement ◽  
Test Data ◽  
High Efficiency ◽  
Measurement Data ◽  
Fire Fighting ◽  
Test Results ◽  
Hydraulic Characteristics ◽  
Fire Extinguishing ◽  
Load Characteristics ◽  
Low Pressures

Цель статьи – получить эмпирические зависимости для характеристик трехплунжерных противопожарных насосов (ТПН), необходимые для автоматизации расчетов систем тушения пожаров на судах с применением распыленной морской воды. Задачи исследования: проверка непротиворечивости данных испытаний; определение расчетных зависимостей производительности ТПН, к.п.д., затраченной мощности от давления. Проведенный анализ результатов испытаний ТПН подтвердил возможность использования предложенных зависимостей в инженерных расчетах. Данные измерений удовлетворительно согласуются с результатами расчетов, за исключением к.п.д. Отклонение экспериментальных точек от эмпирических зависимостей, скорее всего, связано с занижением значений затраченной мощности на испытаниях при небольших давлениях. Предложено для оценки к.п.д. использовать ранее полученную типовую зависимость. Построены графики для характеристик насоса NP25/41-170S. Пример расчета рабочей точки насосной установки с использованием приближенной гидравлической характеристики водяной пожарной системы судна показал высокую эффективность предложенных методик. The purpose of the article is to obtain empirical dependences for the characteristics of three-plunger fire-fighting pumps (TFP), which are necessary for automating calculations of fire extinguishing systems on ships using sprayed seawater. Research objectives: checking the consistency of test data; determining the calculated dependences of the TFP performance, efficiency, power expended on pressure. The analysis of the TFP test results confirmed the possibility of using the proposed dependencies in engineering calculations. The measurement data are in satisfactory agreement with the results of calculations, with the exception of efficiency. The deviation of experimental points from the empirical dependences is most likely due to an underestimation of the power consumed during tests at low pressures. It is proposed to use the previously obtained typical dependence to estimate the efficiency. Graphs are plotted for the characteristics of the NP25/41-170S pump. An example of calculating the working point of a pumping unit using the approximate hydraulic characteristics of the ship's water fire system showed the high efficiency of the proposed methods.

scholarly journals Effect of fine recycled aggregates on the properties of non-cement blended materials

2020 ◽  
Vol 323 ◽  
pp. 01018
Author(s):  
Wei-Ting Lin ◽  
Lukáš Fiala ◽  
An Cheng ◽  
Michaela Petříková
Keyword(s):  
Compressive Strength ◽  
Blast Furnace Slag ◽  
Interface Structure ◽  
Strength Test ◽  
Recycled Aggregates ◽  
Test Results ◽  
Granulated Blast Furnace Slag ◽  
Fine Aggregates ◽  
Compressive Strength Test ◽  
Furnace Slag

In this study, the different proportions of co-fired fly ash and ground granulated blast-furnace slag were used to fully replace the cement as non-cement blended materials in a fixed water-cement ratio. The recycled fine aggregates were replaced with natural fine aggregates as 10%, 20%, 30%, 40% and 50%. The flowability, compressive strength, water absorption and scanning electron microscope observations were used as the engineered indices by adding different proportions of recycled fine aggregates. The test results indicated that the fluidity cannot be measured normally due to the increase in the proportion of recycled fine aggregates due to its higher absorbability. In the compressive strength test, the compressive strength decreased accordingly as the recycled fine aggregates increased due to the interface structure and the performance of recycled aggregates. The fine aggregates and other blended materials had poor cementation properties, resulting in a tendency for their compressive strength to decrease. However, the compressive strength can be controlled above 35 MPa of the green non-cement blended materials containing 20% recycled aggregates.

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