scholarly journals The Consolidated Mathews Stability Graph for Open Stope Design

2021 ◽  
Author(s):  
Ali Mortazavi ◽  
Bakytzhan Osserbay
Keyword(s):  
Probabilistic Approach ◽  
Primary Objective ◽  
Stability Number ◽  
Stability Chart ◽  
The Stability ◽  
Extended Graph ◽  
Stability Graph ◽  
Stope Design

Abstract The stability graph method of stope design is one of the most widely used methods of stability assessments of stopes in underground polymetallic mines. The primary objective of this work is to introduce a new stability chart, which includes all relevant case histories, and to exclude parameters with uncertainties in the determination of stability number. The modified stability number was used to achieve this goal, and the Extended Mathews database was recalculated and compared with the new stability graph. In this study, a new refined Consolidated stability graph was developed by excluding the entry mining methods data from the Extended graph data, and only the non-entry methods data was used. The applicability of the proposed Consolidated stability chart was demonstrated by an open stope example. The stability for each stope surface was evaluated by a probabilistic approach employing a logistic regression model and the developed Consolidated stability chart. Comparing the stability analysis results with that of other published works of the same example shows that the determined Consolidated chart, in which the entry-method data is excluded, produces a more conservative and safer design. In conclusion, the size and quality of the dataset dictate the reliability of this approach.

The issue of "oil shrinkage" during the compounding of oils in the processes of production, collection, preparation and transportation of hydrocarbon raw materials

2021 ◽  
pp. 104-113
Author(s):  
O. P. Deryugina ◽  
E. A. Trapeznikov
Keyword(s):  
Raw Materials ◽  
Raw Material ◽  
Colloidal System ◽  
Main Pipelines ◽  
Different Types ◽  
Preliminary Study ◽  
The Stability ◽  
Mixed Oil

The article discusses the issue of industrial compounding, which improves the quality of the raw materials supplied to the main pipelines. Compounding from "to compound" (English) - to mix. When mixing different types of oil obtained, "incompatibility" is possible, which is expressed in the precipitation of a solid sediment and violation of the stability of the colloidal system and due to the differing properties of oils. Attention to this problem is due to the tightening of requirements for the quality of raw materials that must comply with modern standards. The article discusses the causes of the problem of "incompatibility" of oil during compounding and effective ways of solving it, substantiates the need for a preliminary study of the properties of mixed oil in order to identify possible incompatibility of various types of oil. The standard tests for determination of incompatibility indices characterizing the ability of raw materials to mix are considered. The article substantiates the need to develop methods for diagnosing the incompatibility of oils as the most important task of modern chemical science, the solution of which will improve the quality of the raw material obtained and solve many technological problems in the compounding process.

scholarly journals DEVELOPMENT AND VALIDATION OF A HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC) ANALYTICAL METHOD FOR DETERMINATION OF AMOXICILLIN IN CAPSULES

2016 ◽  
Vol 13 (26) ◽  
pp. 78-87
Author(s):  
Tiago Hickman IGLIN ◽  
Flávia Nathiely Silveira FACHEL ◽  
Amanda Gonçalves GUWZINSKI ◽  
Airton Monza da SILVEIRA ◽  
Filipe de Medeiros ALBANO ◽  
...  
Keyword(s):  
Quality Control ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Forced Degradation ◽  
Semisynthetic Penicillin ◽  
The Stability ◽  
Development And Validation

Amoxicillin, substance-related to semisynthetic penicillin, has been widely used to treat infections caused by various microorganisms, however reports of suitable methods for the quantitative determination and indicative of the stability of formulations containing this substance are rare. Due to lack of studies on the forced degradation of the substance and on the need to monitor the quality of this type of formulation was proposed and validated a method for the determination of amoxicillin content in capsules by high-performance liquid chromatography - HPLC for the quality control of amoxicillin capsules, allowing the provision of useful information about the characteristics of this type of formulation and its stability. The method was validated for parameters of linearity, specificity, accuracy, precision, and robustness

GROUND-STATE PROPERTIES OF SMALL 3He DROPS FROM QUANTUM MONTE CARLO SIMULATIONS

2007 ◽  
Vol 21 (13n14) ◽  
pp. 2124-2133
Author(s):  
ESTER SOLA ◽  
JOAQUIM CASULLERAS ◽  
JORDI BORONAT
Keyword(s):  
Monte Carlo ◽  
Quantum Monte Carlo ◽  
Monte Carlo Study ◽  
Maximum Value ◽  
The Stability ◽  
Quantum Monte Carlo Simulations ◽  
Fixed Node ◽  
Structure Properties

We present recent results from a diffusion Monte Carlo study of small 3 He drops in the limit of zero temperature. Using the same methodology than in previous calculations carried out for bulk 3 He , we have obtained accurate results for their energy and structure properties. A relevant concern of this analysis has been the determination of the stability threshold for self binding. Our results show that the smallest self-bound drop is formed by N = 30 atoms, with preferred orbitals for open shells corresponding to maximum value of the spin. The quality of the upper bound energies provided by the fixed node approximation is analyzed by performing released-node estimations for short released times. Possible improvements of the nodal surface by including BCS-like correlation functions are also discussed.

scholarly journals Development of stability indicating method for quality assessment of African Albendazole tablets

2021 ◽  
Vol 319 ◽  
pp. 01084
Author(s):  
Amine Hssaine ◽  
Miloud El Karbane ◽  
Mohamed Azougagh ◽  
Imad Eddine Houti ◽  
Brahim Benaji
Keyword(s):  
Gradient Elution ◽  
The United States ◽  
Hplc Method ◽  
Stability Indicating ◽  
Stability Indicating Method ◽  
The Stability ◽  
Physical And Chemical ◽  
States Pharmacopeia

In order to assess the quality of Albendazole tablets (Alb) sampled in three countries from West Africa, several physical and chemical tests were performed on tablets at normal conditions. A simple and economic HPLC method has been developed, validated and used for the simultaneous determination of Albendazole (Alb) content, as well as its impurities and the uniformity of its content. The stability-indicating HPLC method was performed on a Symmetry C18-5µm 250 mm × 4.6 mm column with a gradient elution using a mobile phase composed of acetonitrile and sodium acetate buffer. The flow rate was set at 1 mL.min−1 and the eluent was monitored at 295nm. The method was validated for specificity, linearity, accuracy, precision, robustness and detection and quantification limits, in accordance with International Conference on Harmonisation Quality 2 (ICH Q2) guidelines. This method was performed on different Alb samples (originals and generics) products collected from Senegal, Niger and Mali. The obtained results showed that, the contents of the generic tablets from Niger and Mali comply with the United States Pharmacopeia (USP) monograph acceptance criteria. However, more than 20% of the generic tablets don’t meet the USP monograph impurity limits. In conclusion, the described analytical method is simple, sensitive and accurate. Thus, it could be useful for manufacturing and quality control assays.

Determination of Sensor Network Coverage using Probabilistic Approach

1970 ◽  
Vol 111 (5) ◽  
pp. 7-10
Author(s):  
J. Gorecki ◽  
B. Miedzinski ◽  
H. Nouri
Keyword(s):  
Quality Of Service ◽  
Sensor Network ◽  
Lower Cost ◽  
Probabilistic Approach ◽  
Network Coverage ◽  
Coverage Area ◽  
Single Sensor ◽  
Quality Of Service Parameters

Paper elaborates the method to identify near and far coverage area for each sensor estimating quality of service parameters in order to assess the areas of sensor redundancy and shortage. Coverage in near area is used to identify whether single sensor is enough to cover this area (sensor shortage indicating denser sensor layout). Coverage in far area is used to identify which sensors can be removed from the field in order to have lower cost of deployment of sensor network (sensor redundancy). Ill. 3, bibl. 7, tabl. 1 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.111.5.345

scholarly journals Experimental Study of the Variation Dynamic’s for Air Heat Exchanger

2017 ◽  
Vol 9 (3) ◽  
pp. 297-301
Author(s):  
Maryia Marozava ◽  
Dzmitry Hryniuk
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Dynamic Models ◽  
Management Systems ◽  
Stabilization System ◽  
Technological Parameters ◽  
Control Loops ◽  
The Stability

The development of management systems is assigned one of the leading roles. When solving the problems of regulating the technological parameters, various problems arise. One of such problems is the adjustment of control loops. For some control objects, one-time adjustment of the controller parameters can be made, and then it is periodically refined as necessary. In other objects, the changes occur very quickly, but in a certain range. In the latter case, you should first estimate the range of changes. Then find universal robust settings that will ensure the stability and quality of the stabilization system. Some of such objects are air heat exchangers. The article presents the results of the determination of the heat exchanger dynamics. The limits of the variation of the parameters of the dynamic models are determined. There is a significant nonlinearity in the transfer function of the control channel.

scholarly journals REGARDING THE QUALITY OF ASSEMBLY OF THE SCREW CONNECTIONS OF THE MOUNTING ASSEMBLY OF BALL BEARINGS

2021 ◽  
Vol 3 (163) ◽  
pp. 12-15
Author(s):  
V. Lus’
Keyword(s):  
Dynamic Model ◽  
Primary Objective ◽  
Design Parameters ◽  
Ball Bearings ◽  
Threaded Connection ◽  
Vibration Tests ◽  
Technological Frame ◽  
And Control

Application of method of vibrodiagnostics is based on the presence of cross-correlation dependences of dynamic descriptions of all knots from contact pressure in connection through the change of inflexibility of joints. The change of inflexibility of separate elements causes the change of the resulted inflexibility of knot, and at the same time and characteristic it to dynamic descriptions of the artificially created oscillation field: frequencies and amplitudes of resonance vibrations, indexes of damping, phase correlations. There is a task of determination of method of control of the most responsible technological frame-clamping operations at making of such objects: quality of contact connections, ball-bearing knots, fixing of previous pull of ball-bearings and control of isotropicness, inflexibility and dissipative descriptions of the system of pendant of rotor at all stages of drafting, including in the functional state. The primary objective of this work is research of question of influence of non-perfect resiliency and different inflexibility of the supporting bearings on the dynamic reaction of object at external oscillation excitation, determination of estimation of the different inflexibility bearings, determination of accordance of axial inflexibility of ball-bearings supports, them by a basic value. The dynamic model of knot and certain functions of influence of parameters of the system is considered on high-quality indexes. The dynamic model of precision rotor system (PRS) is investigated. Vibration tests at the stage of assembling the structure of the ORS showed that in the process of assembling the elements change the natural frequencies of the system and the quality factor of the oscillating circuits. The resulted dependences allow giving an estimation degree of non-linearity of resilient description and, as a result, different inflexibility of bearings supports as a result of oscillation researches. The sensitivity functions of the design parameters of the complex press-threaded connection in relation to the vibration dynamic parameters – frequencies and amplitudes of resonant oscillations – do not differ qualitatively from those obtained previously.

scholarly journals The Perception of the Generational Assessment of Selected Social Behaviour – A Confirmatory Factor Analysis

2020 ◽  
Vol 20 (2) ◽  
pp. 346-360
Author(s):  
Agnieszka Stanimir
Keyword(s):  
Latent Variables ◽  
Structural Equation ◽  
Structural Equation Models ◽  
Research Problem ◽  
Factors Affecting ◽  
Confirmatory Factor ◽  
The Stability ◽  
The Given

Abstract Research background: The search for stable factors affecting latent variables that reflect the assessment of quality of life in three areas of an individual’s functioning is the background of the study. In the analysis was assumed the existence of the relationships between QoL assessment and subjective factors related to socio-economic aspects. Purpose: The aim of the study was to recognize assessments in given areas of transferring subjective satisfaction with a level of social factors and checking the stability of the assumed relationship between factors describing three areas of functioning: household, country of residence, EU. The next goal was to compare the results obtained in the study of natural relationships between factors with the given systems of these factors in the areas of an individual’s functioning. Characteristics of behaviour were compared in three generations of Europeans. The application objective of the study was to indicate the usefulness of SEM in the research problem. Research methodology: The Standard Eurobarometer, autumn 2018, provided data describing adults from the generations Y, X, and BB. Structural equation models were used. Results: The effect of the used method is the determination of the factors that affect the assessments made by three European Generations in the areas of an individual’s functioning: direct, close and further. Novelty: The analysis showed the usefulness of structural equation models to achieve the goals of the study.

scholarly journals A Feasibility Study on The Implementation of Neural Network Classifiers for Open Stope Design

2021 ◽  
Author(s):  
Amoussou Coffi Adoko ◽  
Festus Saadaari ◽  
Daniel Mireku-Gyimah ◽  
Askar Imashev
Keyword(s):  
Neural Network ◽  
Stability Conditions ◽  
Feed Forward Neural Network ◽  
Graph Method ◽  
Average Accuracy ◽  
Artificial Neural Network Ann ◽  
Neural Network Classifiers ◽  
The Stability ◽  
Stability Graph ◽  
Stope Design

AbstractAssessing the stability of stopes is essential in open stope mine design as unstable hangingwalls and footwalls lead to sloughing, unplanned stope dilution, and safety concerns compromising the profitability of the mine. Over the past few decades, numerous empirical tools have been developed to dimension open stope in connection with its stability, using the stability graph method. However, one of the principal limitations of the stability graph method is to objectively determine the boundary of the stability zones, and gain a clear probabilistic interpretation of the graph. To overcome this issue, this paper aims to explore the feasibility of artificial neural network (ANN) based classifiers for the design of open stopes. A stope stability database was compiled and included the stope dimensions, rock mass properties, and the stope stability conditions. The main parameters included the modified stability number (N’), and the stope stability conditions (stable, unstable, and failed), and hydraulic radius (HR). A feed-forward neural network (FFNN) classifier containing two hidden layers (110 neurons each) was employed to identify the stope stability conditions. Overall, the outcome of the analysis showed good agreement with the field data; most stope surfaces were correctly predicted with an average accuracy of 91%. This shows an improvement over using the existing stability graph method. In addition, for a better interpretation of the results, the associated probability of occurrence of stable, unstable, or caved stope was determined and shown in iso-probability contour charts which were compared with the stability graph. The proposed FFNN-based classifier outperformed the conventional stability graph method in terms of accuracy and better prabablistic interpretation. It is suggested that the classifier could be a reliable tool that can complement the conventional stability graph for the design of open stopes.

Sign in / Sign up

Export Citation Format

Share Document