Research on Vibration Characteristic of Flotation Machine Lower Shaft

2014 ◽  
Vol 552 ◽  
pp. 29-32
Author(s):  
Feng Wu ◽  
Mao He Lai ◽  
Yue Yu
Keyword(s):  
Wall Thickness ◽  
Element Model ◽  
Practical Significance ◽  
Vibration Characteristic ◽  
Practical Application ◽  
Mechanical Agitation ◽  
Flotation Machine ◽  
Hollow Shaft ◽  
The Difference ◽  
Shaft Wall

According to the lower shaft structure feature of a pneumatic and mechanical agitation flotation machine in the practical application, a finite element model is established on the basis of modality analytical theory of vibration structure. Through analyzing the modality characteristics of the lower shaft, the vibration mode of lower shaft is obtained. Moreover, through analyzing the modal characteristics of the lower shaft in condition of different impellers material and lower hollow shaft wall thickness, the conclusion is obtained that more lighter the impeller’ material is, more great the difference between natural frequencies and vibration excitation frequencies is. Another conclusion is that the lower shaft still do not resonate when the wall thickness of lower shaft thin appropriately. The conclusions of this paper have great theoretical and practical significance of further optimization of the flotation machine lower shaft structure.

scholarly journals Ce-Bearing FeSi Alloy Inoculation of Electrically Melted, Low Sulphur Grey Cast Irons for Thin Wall Castings

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1122
Author(s):  
Irina Varvara Balkan ◽  
Iulian Riposan
Keyword(s):  
Wall Thickness ◽  
Structural Characteristics ◽  
Cooling Curve ◽  
Thin Wall ◽  
Cast Irons ◽  
Iron Castings ◽  
Grey Cast ◽  
The Difference ◽  
Thermal Cooling ◽  
Fesi Alloy

Electrically melted and over-heated (>1500 °C) grey cast iron at less than 0.04%S, as commonly used, solidifies large amounts of carbides and/or undercooled graphite, especially in thin wall castings; this is necessary to achieve a stronger inoculation. The efficiency of Ce-bearing FeSi alloy is tested for lower ladle addition rates (0.15 and 0.25 wt.%), compared to the base and conventional inoculated iron (Ba,Ca-bearing FeSi alloy). The present work explores chill and associated structures in hypoeutectic grey iron (3.6–3.8%CE, 0.02%S, (%Mn) × (%S) = 0.013–0.016, Alres < 0.002%), in wedge castings W1, W2 and W3 (ASTM A 367, furan resin sand mould), at a lower cooling modulus (1.1–3.5 mm) that is typically used to control the quality of thin wall iron castings. Relatively clear and total chill well correlated with the standard thermal (cooling curve) analysis parameters and structural characteristics in wedge castings, at different wall thickness, displayed as the carbides/graphite ratio and presence of undercooled graphite morphologies. The difference in effects of the two inoculants addition is seen as the ability to decrease the amount of carbides and undercooled graphite, with Ce-bearing FeSi alloy outperforming the conventional inoculant, especially as the wall thickness decreased. It appears that Ce-bearing FeSi alloy could be a solution for low sulphur, electric melt, thin wall iron castings production.

Method for the simultaneous quantification of n-hexane metabolites: application to n-hexane metabolism determination

1996 ◽  
Vol 15 (6) ◽  
pp. 497-503 ◽  
Author(s):  
T. Soriano ◽  
M. Menéndez ◽  
P. Sanz ◽  
M. Repetto
Keyword(s):  
Similar Pattern ◽  
Analytical Procedure ◽  
Daily Basis ◽  
Practical Application ◽  
Simultaneous Quantification ◽  
Exposed Workers ◽  
Before And After ◽  
Time Requirements ◽  
The Difference

1 The described analytical procedure permits the simultaneous determination of the main n-hexane meta bolites in urine. 2-Hexanone, 2-hexanol, 2, 5-hexanediol and 2, 5-hexanedione, were chosen to dose the rats used in this study. All urine samples were collected and analysed on a daily basis, before and after acidic hydrolysis (pH 0.1) by GC/MS. 2-Hexanone, 2, 5-dimethylfurane, γ-valerolac tone and 2, 5-hexanedione were determined before hydro lysis ; 2-hexanol and 2, 5-hexanediol, after hydrolysis; and 5-hydroxy-2-hexanone and 4, 5-dihydroxy-2-hexanone were calculated by the difference between γ-valerolactone and 2, 5-hexanedione with and without hydrolysis, respectively. 2 A metabolic scheme was proposed reflecting the biotransformations undergone by the four compounds assayed. We consider 2, 5-dimethylfurane as a 'true metabolite' because the quantities detected were always greater before hydrolysis. 3 It has been reported that human and rat n-hexane metabolism follow a similar pattern. Therefore, as a practical application and without increasing either sample or time requirements, the simultaneous quantifi cation of the different metabolites and their excretion profile could provide better information about the metabolic situation of exposed workers than the determi nation of 2, 5-hexanedione alone. According to our experimental results, 4, 5-dihydroxy-2-hexanone itself would be a good toxicity indicator.

Near Surface Research and Excitation Horizon Prediction Based on Old River Course of Xiaoqing River in Shan Dong

2013 ◽  
Vol 664 ◽  
pp. 94-98
Author(s):  
Guang De Zhang
Keyword(s):  
Seismic Data ◽  
Practical Significance ◽  
Cone Penetration ◽  
Surface Deposition ◽  
Near Surface ◽  
Sedimentary Characteristics ◽  
The Difference ◽  
Exploration Area ◽  
Data Requirements ◽  
Static Cone Penetration Test

Following deepened exploration and development in Shengli exploration area, seismic data requirements are also getting higher and higher. However, in recent years the difference of Xiaoqing river on both sides have made us know that the importance of this problem. In view of the above, this task is aimed at quaternary shallow of old river course within Xiaoqing River. Our analysis of lithology and sedimentary characteristics are using static cone penetration test and rock core exploration method, and we want to reappear near surface deposition of old river course within Xiaoqing River. The research is close combined with the exploration demand and theoretical study, so it has important theoretical and practical significance.

scholarly journals Global metabolomic and lipidomic analysis reveals the potential mechanisms of hemolysis effect of Ophiopogonin D and Ophiopogonin D' in vivo

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Huan-Hua Xu ◽  
Zhen-Hong Jiang ◽  
Cong-Shu Huang ◽  
Yu-Ting Sun ◽  
Long-Long Xu ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Principal Component ◽  
Partial Least Square ◽  
Least Square ◽  
Practical Significance ◽  
Plasma Metabolites ◽  
Active Components ◽  
The Difference

Abstract Background OPD and OPD' are the two main active components of Ophiopogon japonicas in Shenmai injection (SMI). Being isomers of each other, they are supposed to have similar pharmacological activities, but the actual situation is complicated. The difference of hemolytic behavior between OPD and OPD' in vivo and in vitro was discovered and reported by our group for the first time. In vitro, only OPD' showed hemolysis reaction, while in vivo, both OPD and OPD' caused hemolysis. In vitro, the primary cause of hemolysis has been confirmed to be related to the difference between physical and chemical properties of OPD and OPD'. In vivo, although there is a possible explanation for this phenomenon, the one is that OPD is bio-transformed into OPD' or its analogues in vivo, the other one is that both OPD and OPD' were metabolized into more activated forms for hemolysis. However, the mechanism of hemolysis in vivo is still unclear, especially the existing literature are still difficult to explain why OPD shows the inconsistent hemolysis behavior in vivo and in vitro. Therefore, the study of hemolysis of OPD and OPD' in vivo is of great practical significance in response to the increase of adverse events of SMI. Methods Aiming at the hemolysis in vivo, this manuscript adopted untargeted metabolomics and lipidomics technology to preliminarily explore the changes of plasma metabolites and lipids of OPD- and OPD'-treated rats. Metabolomics and lipidomics analyses were performed on ultra-high performance liquid chromatography (UPLC) system tandem with different mass spectrometers (MS) and different columns respectively. Multivariate statistical approaches such as principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA) were applied to screen the differential metabolites and lipids. Results Both OPD and OPD' groups experienced hemolysis, Changes in endogenous differential metabolites and differential lipids, enrichment of differential metabolic pathways, and correlation analysis of differential metabolites and lipids all indicated that the causes of hemolysis by OPD and OPD' were closely related to the interference of phospholipid metabolism. Conclusions This study provided a comprehensive description of metabolomics and lipidomics changes between OPD- and OPD'-treated rats, it would add to the knowledge base of the field, which also provided scientific guidance for the subsequent mechanism research. However, the underlying mechanism require further research.

Conditions for the development of the philosophy of non-violence in the modern world

2020 ◽  
pp. 337-352
Author(s):  
Tolganay V. Mustafina-Kulchmanova ◽  
Zhabayhan M. Abdildin ◽  
Kudaibergen A. Temirgaliev ◽  
Kuralay S. Yermagambetova ◽  
Manifa S. Sarkulova
Keyword(s):  
Public Opinion ◽  
Comparative Study ◽  
Political Science ◽  
Practical Significance ◽  
Modern World ◽  
Practical Application ◽  
Theoretical Methods ◽  
University Teachers ◽  
Analysis And Synthesis ◽  
And Behavior

This article addresses the issues of the genesis of non-violence and the practical application of non-violent practices in the context of modern realities. The phe-nomenon of non-violence is seen in close connection with violence, which is more often reflected in the form of wars, military clashes, and conflicts. The article pro-vides an analysis of the use of non-violent practices and the possibility of develop-ing peacekeeping in public opinion and behavior. During the preparation of this article, a review and comparative study of various literature aimed at studying non-violence were carried out. Together with the philosophical works, various ma-terials of a political science character are studied. In preparing this work, they were used as general theoretical methods, such as analysis and synthesis. At the same time, analogies, systematization, etc. were used. The materials of the article sug-gest practical significance for university teachers of humanitarian/philosophical specialties.

scholarly journals THEORETICAL AND PRACTICAL VALUE OF THE REVIEWS ON UKRAINIAN TERMINOLOGY DICTIONARIES OF THE LATE XXth AND THE EARLY XXIst CENTURIES

2019 ◽  
pp. 96-106
Author(s):  
Tetiana Petrova
Keyword(s):  
Structural Parameters ◽  
Characteristic Parameter ◽  
Practical Significance ◽  
Practical Realization ◽  
Practical Application ◽  
Research Material ◽  
Xxist Century ◽  
Normative Term ◽  
The Subject ◽  
Methodological Principles

The aim of the research is to determine the theoretical and practical significance of the reviews on natural sciences terminology dictionaries. The object of the research is a system of parametric measurements of terminology dictionaries, the subject is critical remarks on the structural parameters representation of terminology dictionaries. The research material is the texts of the reviews published during the late XXth and the early XXIst centuries. Тhe following methods were used: lexicographic analysis of the dictionary parameters, the quantitative analysis and the comparative one. As a result of the research, it is determined that throughout the analyzed period the experts focus on definition and translation dictionaries as well as reference dictionaries. Most remarks are made to the dictionaries of the early XXIst century. The potential importance of practical application of the results is to improve the theoretical and methodological principles and means of terminology dictionaries creation, as well as their use to develop new (combined) type that comprehensively represent the vocabulary of a particular branch of science. Conclusions: 1) the critical comments on professional definition dictionaries relate to such of their parameters as: ‘introduction / preface’, ‘encyclopedia information’, ‘dictionary register’, ‘definition’, ‘list of references’; 2) translation definition dictionaries have quantitative drawbacks regarding the representation of such structural parameters: ‘dictionary register’, ‘translation area’, ‘definition’; 3) to the parameters of reference dictionaries the following critical comments are made: to replace the title loan term by the normative term; to add the ‘accent characteristic’ parameter; to match the title terms with their definitions etc. Theoretical and practical significance of the reviews on terminology dictionaries gives the possibility to systematize the drawbacks revealed by critics in the representation of structural parameters of such publications, for the purpose to improve the fundamental theoretical and methodological foundations of metaterminography and the practical realization of high-quality works.

scholarly journals The Analysis, Discussion and Suggestions for the Mesh Reinforcement Technique of Polymer Mortar Wire Rope

2012 ◽  
Vol 5 ◽  
pp. 271-276
Author(s):  
Shu Ren Zhang ◽  
Zhong Long Li
Keyword(s):  
Engineering Application ◽  
Wire Rope ◽  
Practical Significance ◽  
Strengthening Effect ◽  
Technical Standards ◽  
Healthy Development ◽  
Mesh Reinforcement ◽  
Polymer Mortar ◽  
The Difference ◽  
Correct Understanding

The mesh reinforcement technique of polymer mortar wire rope is a new reinforcement technique used more in the domestic fittest reinforcement project recent years. Recently, there is no unified technical standards, the detailed practice is not same in practical work. There are big differences among the reinforcement effects. The key issue of wire rope is whether add prestressed or not. If add, how much should be prestressed? The difference of the actual practice and reinforcement effect reflects the understanding gap polymer mortar wire rope of mesh reinforcement technique action principle of the designer. A correct understanding of polymer mortar wire rope of mesh reinforcement technique the mechanism and the objective analysis strengthening effect and actively explore research in engineering application problems have a practical significance to promote the healthy development of the structure strengthening technology.

scholarly journals A Comparison of the Arithmetic and Geometric Means in Estimating Stump Diameter, Basal Area, and Volume in Appalachian Hardwoods

2007 ◽  
Vol 24 (1) ◽  
pp. 71-73 ◽  
Author(s):  
Harry V. Wiant ◽  
John R. Brooks
Keyword(s):  
Geometric Mean ◽  
Basal Area ◽  
Cross Sectional Area ◽  
Practical Significance ◽  
Sectional Area ◽  
Cross Sectional ◽  
Geometric Means ◽  
The Difference ◽  
Appalachian Hardwoods ◽  
Stump Diameter

Abstract The difference between the use of the arithmetic and geometric means for estimation of average stump diameter, stump cross-sectional area and estimated tree volume was investigated using measurements from 739 stumps from an Appalachian hardwood stand located in central West Virginia. Although average stump diameter, cross-sectional area, and tree volumes were statistically different between estimates based on the arithmetic and geometric mean diameter, these differences were of little practical significance. The difference in average stem diameter, cross-sectional area, tree cubic volume, and board foot volume were 0.05 in, 0.01 ft2, 0.45 ft3, and 2.41 bd ft, respectively.

Modal Analysis of the Cable-Stayed Space Truss Combining ANSYS and MSC.ADAMS

2010 ◽  
Vol 121-122 ◽  
pp. 832-837 ◽  
Author(s):  
Jing Jun Zhang ◽  
Ji Tao Zhong ◽  
Li Li He ◽  
Rui Zhen Gao
Keyword(s):  
Qualitative Analysis ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Vibration Characteristic ◽  
Flexible Bodies ◽  
Space Truss ◽  
Stay Cables ◽  
Dynamic Analyses ◽  
Simulation Results ◽  
The Difference

Modal analysis, which is applied to verify the vibration characteristic of structures, is the basis of various dynamic analyses. In this paper, firstly, a cable-stayed space truss, consisting of stay cables, columns and space truss, is built in ANSYS. Secondly, modal analysis is performed to confirm the natural frequencies of the structure and 10 modes are extracted. Thirdly, a modal neutral file including all necessary information of flexible bodies is generated by ANSYS and then imported into ADAMS for further modal analysis. Finally, comparison of results between ANSYS and ADAMS are summarized and qualitative analysis is carried out aiming at the difference of natural frequencies between ANSYS and ADAMS. The simulation results indicate that the interface between the two tools has strong compatibility regardless of minor errors in it.

The productivity of breeding ewes grazing on lucerne or grass and clover pastures on the tablelands of Southern Australia. III. Lamb mortality and weaning percentage

1984 ◽  
Vol 35 (5) ◽  
pp. 709 ◽  
Author(s):  
JR Donnelly
Keyword(s):  
Early Spring ◽  
Practical Significance ◽  
Cold Weather ◽  
Late Winter ◽  
Maternal Weight ◽  
Risk Of Death ◽  
Probability Of Death ◽  
The Difference ◽  
Stocking Rates

Weaning percentage and perinatal mortality of lambs born in late winter or early spring to Merino and Border Leicester x Merino ewes grazing at several stocking rates on lucerne or phalaris-clover pastures were measured over 2 years. Weaning percentages for mature crossbred ewes declined linearly from 136 lambs per 100 ewes joined when stocked at 9 ha-1 to 100 for those at 18 ha-1. For mature Merino ewes, the values were 109 and 70 respectively. Weaning percentages were similar on lucerne and phalaris pastures, although 8% more lambs were born to ewes grazing on phalaris; higher mortality in lambs born as multiples eliminated the difference. Death from exposure during the first 3 days of life was the most important cause of lamb losses. For lambs born as singles to Merino ewes the probability of death from exposure was up to 0.4, and reached 0.6 for lambs born as multiples. For single and multiple lambs born to crossbred ewes equivalent probabilities were 0.25 and 0.4 respectively. These probabilities were reduced if maternal weight was high at lambing, the reduction being of practical significance in very cold weather, particularly if the proportion of multiple births was high. Under mild conditions, where the probability of death from exposure was low, reductions in mortality from high ewe weight at lambing were of little consequence. Long-term weather records kept at the experimental site near Canberra show that a high risk of death in new-born lambs is likely from early June to mid-September. Throughout this period deaths from exposure could be expected to exceed 30% in lambs born as multiples to Merino ewes.

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