A short-term production planning model for dimension stone quarries

In this paper, problem of short-term production planning for dimension stone quarries was mathematically modeled using a binary integer programming. The model includes an objective function, which was founded as the minimization of the costs due to the total cutting planes of the blocks. This objective may cause to maximization of the net present value (NPV) in dimension stone quarries. During the mathematical modeling the essential constraints are dimension stone quarry capacities and the market demand, block accessibility for the equipment and the reserve constraints. As a base, an optimal size and shape of extractable blocks should be first assigned according to the available extraction technique and the market demand, in order to create a geological block model. Then an economical block model is provided by assignment of a value of "one" for ore blocks and "zero2 for waste. Maximum profitability and minimum amount of the ore wastage can be gained using this plan and modeling

Roof falls: An inherent risk in underground coal mining

The occurrence of rock falls in underground coal mines entails detrimental effects as fatal or non-fatal injuries on workers, stoppages in mining operations and breakdown of equipment. In this paper, a risk assessment approach on the basis of a decision analysis trend is employed in order to assess the possibility of and manage roof falls. Risk is then assessed by determination of likelihood of occurrence and the cost of consequences (outcomes). In this regard, collected real roof fall data from Tabas and Kerman coal regions comprising of several underground coal mines are used. It is concluded that the annual accidents due to the roof falls occurrence in the all investigated mines are so high that it is economically feasible to improve the support systems and to implement a suitable educational program as well as an accurate supervision and other elements of safety management

Determination of the Optimum Crown Pillar Thickness Between Open Pit and Block Caving

In this paper, a relationship between dependant parameters and the crown pillar thickness is first introduced. This relationship defines geotechnical problems caused by thin pillars and economic considerations created by pillars that are thicker than the optimum size. For this purpose, a dimensional analysis as an effective physico-mathematical tool was used. This technique restructures the original dimensional variables of a problem into a set of dimensionless products using the constraints imposed upon them by their dimensions. A model is hence introduced that calculates the optimum pillar thickness. The relationship introduced here and the method applied can be used by mining engineers in all situations where a combined open-pit and block caving method is deemed to be the most appropriate mining method

An approach towards ascertaining open-pit to underground transition depth

In this study, in order to determine OP to Ug mining TD of tabulate deposits, through various states some formulas were concluded. These formulas resulted based on the allowable and overall stripping ratios. For this objective, an analytical procedure was served. The contemplated states are variously combined from the deposits with outcrops or overburden and including maximum or minimum possible pit floor width

Assessment of risks of tunneling project in Iran using artificial bee colony algorithm

The soft computing techniques have been widely applied to model and analyze the complex and uncertain problems. This paper aims to develop a novel model for the risk assessment of tunneling projects using artificial bee colony algorithm. To this end, the risk of the second part of the Emamzade Hashem tunnel was assessed and analyzed in seven sections after testing geotechnical characteristics. Five geotechnical and hydrological properties of study zone are considered for the clustering of geological units in front of tunneling project including length of tunnel, uniaxial compressive strength, rock mass rating, tunneling index Q, density and underground water condition. These sections were classified in two low-risk and high-risk groups based on their geotechnical characteristics and using clustering technique. It was resulted that three sections with lithologies Durood Formation, Mobarak Formation, and Ruteh Formation are placed in the high risk group and the other sections with lithologies Baroot Formation, Elika Formation, Dacite tuff of Eocene, and Shear Tuff, and Lava Eocene are placed in the low risk group. In addition, the underground water condition and density with 0.722 and 1 Euclidean distances have the highest and lowest impacts in the high risk group, respectively. Therefore, comparing the obtained results of modelling and actual excavation data demonstrated that this technique can be applied as a powerful tool for modeling risks of tunnel and underground constructions

Mining method selection and transition depth determination problems - which one is in priority of consideration?

During this paper, in order to identify the priority of consideration between the problems of “mining method selection” and “determining transition depth from open-pit to underground mining” an accurate procedure is introduced step by step. First, it is essential to specify if an ore deposit that potentially will have mined by a combined method of open-pit and underground mining. In this case, optimal final open-pit limit and depth must be initially determined. After that, if the rest of deposit below open-pit limit is economically considerable, it is necessary to select the most adequate underground method with emphasis on the high production rate and low cost methods. Then, it is necessary to determine optimal transition depth from open-pit to underground mining considering a crown pillar immediately below open-pit mining. Finally, the procedure with its algorithm was used for an iron ore deposit with the combined mining potential

Permeability Analysis based on information granulation theory

This paper describes application of information granulation theory, on the analysis of "lugeon data". In this manner, using a combining of Self Organizing Map (SOM) and Neuro-Fuzzy Inference System (NFIS), crisp and fuzzy granules are obtained. Balancing of crisp granules and sub- fuzzy granules, within non fuzzy information (initial granulation), is rendered in open-close iteration. Using two criteria, "simplicity of rules "and "suitable adaptive threshold error level", stability of algorithm is guaranteed. In other part of paper, rough set theory (RST), to approximate analysis, has been employed >.Validation of the proposed methods, on the large data set of in-situ permeability in rock masses, in the Shivashan dam, Iran, has been highlighted. By the implementation of the proposed algorithm on the lugeon data set, was proved the suggested method, relating the approximate analysis on the permeability, could be applied.Comment: 8 pages,7 figure

Battered Child Syndrome; a Case Study

One of the important and usual missed causes of pediatric traumas is child abuse. This ominous phenomenon, which can be presented physically, psychologically, sexually, and emotionally has grown significantly in recent years. Many children are not diagnosed in the early stages of evaluation. Battered Child Syndrome is used to describe the clinical condition of the child serious physical abuse by parents or caregivers. Medical staff should always keep the syndrome in their mind for those brought to the emergency department with trauma. In this report, we described a patient complained of dysphagia following a falling from a height and multiple epidural hematomas and final diagnosis of battered child syndrome

Demographic status of married females with suicide attempts referred to the emergency department of Sina hospital in Tabriz-Iran

Objective: According to the definition of World Health Organization (WHO), attempting suicide is an act that a person intentionally and without others’ interference shows an abnormal behavior (such as harming themselves or eating a drug higher than treatment dose) and his objective is realizing his expected changes. The purpose of this study was to investigate the demographic characteristics of married women with suicidal attempt and a variety of methods used to suicide among them who referred to the emergency department of Sina hospital in Tabriz. Methods: In a cross-sectional study 472 married female patients with suicide attempt who referred to the emergency department of Sina hospital in Tabriz in 2014 entered the study and relevant information was collected. Obtained information was analyzed using SPSS version 17.0. Results: Findings showed that the most frequent method of suicide was drug use (99.8%). A significant relationship was found between the type of drug used and seasons of the year. The majority of the population (90.5%) lived in urban areas and based on statistical analyses, a significant relationship was found between residency and type of drug used. Conclusion: According to the results of this study it can be concluded that drug use is the most frequent method of suicide that is done with a higher frequency in summer. Thus, rational prescription of drugs by physicians can be considered as one of the factors that can prevent suicide. Keywords: Suicide, Married persons, Females, Emergency departments, Hospita

Epidural Hematoma Following Hemodialysis in a Methanol Poisoned Pa-tient; a Case Report

Brain injury associated with methanol toxicity can be ischemic, necrotic or hemorrhagic in nature. It most commonly affects the putamenal area bilaterally, but can be seen in other locations. This report describes a 22-year-old intoxicated patient who developed an epidural hematoma following hemodialysis. Heparinization during hemodialysis may contribute to cerebral hemorrhagic complications in methanol poisoning. In addition, a history of head trauma may raise the incidence of post-hemodialysis hemorrhagic brain insults. Heparin-free dialysis or peritoneal dialysis can be a good option in these cases