Investigation to control mine dust using surfactants and a new approach for eliminating their negative effect on flotation

1991 ◽  
Vol 8 (1) ◽  
pp. 38-42
Author(s):  
M. A. Cristovici
Keyword(s):  
New Approach ◽  
Mine Dust ◽  
Negative Effect

Recycling red mud from the production of aluminium as a red cement-based mortar

2017 ◽  
Vol 35 (5) ◽  
pp. 500-507 ◽  
Author(s):  
Xiaojie Yang ◽  
Jianfeng Zhao ◽  
Haoxin Li ◽  
Piqi Zhao ◽  
Qin Chen
Keyword(s):  
Red Mud ◽  
Mechanical Performance ◽  
Effective Management ◽  
Current Management ◽  
New Approach ◽  
Air Content ◽  
Negative Effect ◽  
Series Of Experiments ◽  
Hardened Properties ◽  
Performance Variations

Current management for red mud is insufficient and a new method is needed. A series of experiments have been carried out to develop a new approach for effective management of red mud. Mortars without or with 3%, 6% and 9% red mud were prepared and their fresh and hardened properties were measured to access the possibility of recycling the red mud in the production of red cement-based mortar. The mechanisms corresponding to their mechanical performance variations were explored by X-ray powder diffraction and scanning electron microscopy. The results show that the fresh mortars with red mud present an increase of viscosity as compared with the control. However, little difference is found when the content of red mud is altered. It also can be seen that red mud increases flow time and reduces the slump flow of the mortar. Meanwhile, it is found that mortar with red mud is provided with higher air content. Red mud is eligible to adjust the decorative mortar colour. Compressive strength of mortar is improved when less than 6% red mud is added. However, overall it has a slightly negative effect on tensile bond strength. It decreases the Ca(OH)2 content and densifies the microstructure of hardened paste. The heavy metal concentrations in leachates of mortars with red mud are much lower than the values required in the standard, and it will not do harm to people’s health and the environment. These results are important to recycle and effectively manage red mud via the production of red cement-based mortar.

scholarly journals New approach and new program for analyses of false negatives-contaminated data in medicine and biology

2019 ◽  
Author(s):  
Jaroslav Flegr ◽  
Petr Tureček
Keyword(s):  
Permutation Test ◽  
Statistical Tests ◽  
Empirical Studies ◽  
False Negative ◽  
False Negatives ◽  
New Approach ◽  
Contaminated Data ◽  
Significant Difference ◽  
Duration Of Infection ◽  
Negative Effect

AbstractBackgroundNo serological assay has 100% sensitivity. Statistically, the concentration of specific antibodies against antigens of parasites decreases with the duration of infection. This can result in false negative outputs of diagnostic tests for the subjects with old infectiong, e.g., for individuals infected in childhood. When a property of seronegative and seropositive subjects is compared under these circumstances, the statistical tests can detect no significant difference between these two groups of subjects, despite the fact that infected and noninfected subjects differ. When the effect of the infection has a cumulative character and subjects with an older infection (potential false negatives) are affected to a greater degree, we can even get paradoxical result of the comparison – the seronegative subjects have on average lower value of certain traits, e.g. IQ, despite the infection having a negative effect on the trait. A permutation test for the contaminated data, implemented, e.g., in the program Treept or available as a comprehensibly commented R function in the supplement of this paper, can be used to reveal and to eliminate the effect of false negatives.MethodsWe used a Monte Carlo simulation in the program R to show that the permutation test implemented in the programs Treept and PTPT is a conservative test.ResultsWe showed that the test could provide false negative but not false positive results if the studied population contains no subpopulation of false negative subjects. We also introduced R version of the test expanded by skewness analysis, which helps to estimate the proportion of false negative subjects based on the assumption of equal data skewness in groups of healthy and infected individuals.ConclusionsBased on the results of simulations and our experience with empirical studies we recommend the usage of permutation test for contaminated data whenever seronegative and seropositive individuals are compared.

scholarly journals Lemna minor Bioassay Evaluation Using Computer Image Analysis

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2207
Author(s):  
Oto Haffner ◽  
Erik Kučera ◽  
Peter Drahoš ◽  
Ján Cigánek ◽  
Alena Kozáková ◽  
...  
Keyword(s):  
Computer Vision ◽  
Human Factor ◽  
Lemna Minor ◽  
Negative Effects ◽  
Computer Image Analysis ◽  
New Approach ◽  
Growth Inhibition Test ◽  
Negative Effect ◽  
Number Of Leaves ◽  
Two Parameters

This article deals with using computer vision in the evaluation of the Lemna minor bioassay. According to the conventional method, the growth of Lemna minor mass is determined from the number of leaves grown. In this work, instead of counting individual leaves, we propose measuring the area occupied by the leaves using computer vision and compare the new approach with the conventional one. The bioassay is performed according to the ISO 20079 standard as a 168 h growth inhibition test; the aim of the experiment was to quantify the negative effects on the vegetative growth using two parameters—the number of leaves and the area occupied by the leaves. The method based on image processing was faster and also more precise since it enabled us to detect the negative effect of the tested substance on leave size, not only on their number. It can be concluded that the toxic effect has shown to be more significant when considering the leaves area rather than the number of leaves. Moreover, mistakes caused by human factor during leaves counting are eliminated using the computer vision based method.

scholarly journals The great depression as a global currency crisis: An Argentine perspective

2020 ◽  
Author(s):  
Leonidas Zelmanovitz ◽  
Carlos Newland ◽  
Juan Carlos Rosiello
Keyword(s):  
Great Depression ◽  
Latin American ◽  
Gold Standard ◽  
Currency Crises ◽  
Monetary Policies ◽  
New Approach ◽  
The Great Depression ◽  
Negative Effect ◽  
The Great War ◽  
Latin American Countries

Abstract Many of the works that have tried to understand the proximate causes of the Great Depression have emphasized the consequences of maintaining the Gold Standard during the interwar period, as its innate inflexibility prevented the use of expansive monetary policies and generated recessionary deflationary processes. Another perspective, both complementary and different, is that offered by new works that consider the Great Depression as to some extent a consequence not so much of a Gold Standard per se, but of the return to redemability at an overvalued parity after the Great War. The novelty of this new approach is to stress the negative effect of maintaining an unbalanced price for the metal over time. The models that have analyzed the currency crises suffered in recent decades by many Latin American countries help to understand the path that led the world to the Great Depression, with the convertibility regime applied in Argentina between 1991 and 2001 being particularly relevant.

New Approach for Noncircular Following Grinding of Crankshaft Pin

2012 ◽  
Vol 497 ◽  
pp. 46-55 ◽  
Author(s):  
Hong Xiang Yu ◽  
Yu Zhang ◽  
Xu Hua Pan ◽  
Meng Chen Xu
Keyword(s):  
Computer Simulation ◽  
Motion Control ◽  
Experimental Test ◽  
Control Algorithm ◽  
Motion Model ◽  
New Approach ◽  
Straight Line ◽  
Negative Effect ◽  
Relationship Of ◽  
Line Relationship

A new approach for the precise grinding of crankshaft pin is presented. In which, noncircular following strategy is investigated based on the motion model consists of horizontal feeding axis, additional lifting axis for wheel frame, and the active rotary axis for workpiece. The straight line relationship of wheel center, pin center and grinding point is ensured by the synchronism between standard arc interpolation motion of wheel frame and eccentric circular motion of pin section. Comparing with traditional tangential point tracing scheme, both constant grinding line-speed and simple control algorithm are fulfilled simultaneously. The negative effect of perpendicular deviation introduced by lifting axis is kinematically analyzed as well as the dynamic response error of servo system, and solving methods are carried out accordingly. By computer simulation and experimental test, the reported noncircular following strategy emerges good characteristics in the manufacturing of crankshaft, such as a strong adaptability for wheel wearing, simple motion control and high roundness precision.

The O–C diagrams of minor planets − a new approach to modelling the rotation

1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss
Keyword(s):  
Error Analysis ◽  
Time Dependence ◽  
Theoretical Work ◽  
Minor Planet ◽  
Minor Planets ◽  
New Approach ◽  
Preliminary Results ◽  
Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Processing Immunoperoxidase Labeled Cell Monolayers and Cryostat Sesctions For Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 714-715
Author(s):  
K. Chien ◽  
R. Van de Velde ◽  
I.P. Shintaku ◽  
A.F. Sassoon
Keyword(s):  
Cell Monolayer ◽  
Cell Types ◽  
Surface Antigens ◽  
Immunoperoxidase Method ◽  
Reaction Step ◽  
Hot Plate ◽  
Air Drying ◽  
New Approach ◽  
Cell Monolayers ◽  
Glass Slides

Immunoelectron microscopy of neoplastic lymphoma cells is valuable for precise localization of surface antigens and identification of cell types. We have developed a new approach in which the immunohistochemical staining can be evaluated prior to embedding for EM and desired area subsequently selected for ultrathin sectioning.A freshly prepared lymphoma cell suspension is spun onto polylysine hydrobromide- coated glass slides by cytocentrifugation and immediately fixed without air drying in polylysine paraformaldehyde (PLP) fixative. After rinsing in PBS, slides are stained by a 3-step immunoperoxidase method. Cell monolayer is then fixed in buffered 3% glutaraldehyde prior to DAB reaction. After the DAB reaction step, wet monolayers can be examined under LM for presence of brown reaction product and selected monolayers then processed by routine methods for EM and embedded with the Chien Re-embedding Mold. After the polymerization, the epoxy blocks are easily separated from the glass slides by heatingon a 100°C hot plate for 20 seconds.

TEM study of a biofilm on copper corrosion

1996 ◽  
Vol 54 ◽  
pp. 220-221
Author(s):  
W. A. Chiou ◽  
N. Kohyama ◽  
B. Little ◽  
P. Wagner ◽  
M. Meshii
Keyword(s):  
Marine Bacterium ◽  
Culture Medium ◽  
Copper Alloys ◽  
Pure Copper ◽  
Localized Corrosion ◽  
Natural Seawater ◽  
Copper Corrosion ◽  
New Approach ◽  
The Past ◽  
Copper Tolerant

The corrosion of copper and copper alloys in a marine environment is of great concern because of their widespread use in heat exchangers and steam condensers in which natural seawater is the coolant. It has become increasingly evident that microorganisms play an important role in the corrosion of a number of metals and alloys under a variety of environments. For the past 15 years the use of SEM has proven to be useful in studying biofilms and spatial relationships between bacteria and localized corrosion of metals. Little information, however, has been obtained using TEM capitalizing on its higher spacial resolution and the transmission observation of interfaces. The research presented herein is the first step of this new approach in studying the corrosion with biological influence in pure copper.Commercially produced copper (Cu, 99%) foils of approximately 120 μm thick exposed to a copper-tolerant marine bacterium, Oceanospirillum, and an abiotic culture medium were subsampled (1 cm × 1 cm) for this study along with unexposed control samples.

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