JOURNAL OF MINING AND GEOLOGICAL SCIENCES, Vol. 61, Number 2
ISSN 2682-9525 (print)
ISSN 2683-0027 (online)
СЪДЪРЖАНИЕ
CONTENTS

Evgenia Alexandrova Development of a 3D Model for the Assessment of the Stability of the Slopes in the Mizia Quarry	5
Daniel Georgiev Optimisation of Sampling of Coal From the Obedinen Open Cast Mine and the Republika Mine	10
Stojance Mijalkovski, Zoran Despodov, Dejan Mirakovski, Vancho Adjiski, Nikolinka Doneva Analysis of the Ore Recovery and Ore Dilution in the Underground Mine for Lead and Zinc „SASA“ – M. Kamenica	13
Tondera D., Beier, D., Tamaskovics N., Pavlov P., Totev, L. Groundwater Impact Investigation Due to Installation of a “LWS” Silicate Gel Sealing Sole in the Water Saturated Soil Zone	19
Babich A.V., Vinnikov V.A. On the Determination of the Optimum Time of Microwave Exposure to Pyrite-Containing Ore	24
Valeriy Slobodyanyuk, Ivan Maksimov, Roman Slobodyanyuk Influence of the Arrangement and Performance of Shovels on the Optimum Position for Run-of-Mine Stock Location	28
Roman Slobodyanyuk Analysis and Development of Slope Hoisting Systems for Open Pit Mines	33
Zahari Dinchev, Yasen Gorbunov, Nadezhda Kostadinova Velocity Field Visualization, Measured with 3D Ultrasonic Anemometer	39
Blagovesta Vladkova, Luka Arbaliev, Veronika Karadjova Safe Treatment of Expired Medicines	45
Irena Grigorova, Marin Ranchev, Ivan Nishkov Mass Measurement for Metal Accounting in Mineral Processing Plants	53
Marin Ranchev, Irena Grigorova, Ivan Nishkov Sampling in Mineral Processing – Review of Practices	59
Tsvetelina Ivanova Pre-Contact Column Flotation Machines – Design Features and Principles of Operation	65
Alexander А. Klemiatov, Alexander I. Kalugin, Ilya А. Gribov, Nikita А. Rozhdestvenskii, Alexey Yu. Barabash, Yulia S. Gordeeva Some Aspects of the Revamp of Existent Beneficiation Plants	69
Norov Аndrey, М. Pagaleshkin, Denis А., Fedotov Pavel S. The Effect of Impurity Composition of Phosphate Rock on the Technology of its Processing and Properties of Final Products	75
Petya Gencheva, Lubomir Djerahov High-Strength Synthetic Fibers and Nano-Sized Particles of SiO2 Combined into one Composite System for Ballistic Protection	82
Marinela Panayotova, Neli Mintcheva, Lubomir Djerahov, Gospodinka Gicheva Kinetics and Thermodynamics of Silver Ion Immobilisation by Natural Clinoptilolite	87
Marinela Panayotova, Gospodinka Gicheva, Nely Mintcheva, Lubomir Djerahov Study on the Air Quality During the Operation of the Mizia Quarry	92
Gospodinka Gicheva, Neli Mincheva Effect of Amines on the Silver Nanoparticles Formation at Room Temperature	97
Maria Manastirli, Irena Spasova Leading Principles and Practices in the Management of Construction Wastes	102
M. Nikolova, I. Spasova, S. Groudev, P. Georgiev, V. Groudeva Electricity Generation in Microbial Fuel Cells by Means of Different Microorganisms	106
Irena Spasova, Marina Nikolova, Plamen Georgiev, Stoyan Groudev Microbial Pre-Treatment Of A Gold-Bearing Flotation Pyrite Concentrate By Means Of Mesophilic And Moderate Thermophilic Bacteria And By Extreme Thermophilic Archaea	109
Georgiev P., Nikolova M., Spasova I., Groudev S., Groudeva V. The Effect of the Pulp Density of a Copper Slag on the Efficiency of its Bioleaching by Means of Different Microorganisms	112
Violeta Trifonova-Genova Analytical Expressions for Stresses in Steeply Stratified Rock Mass Aroundan Opening in the Shape of an Ellipse	115
Stefan Pulev Self-Clearing of Vibrating Screening Systems	119
Ivan Nikolov, Alexandre Loukanov, Elena Ustinovich, Anatoliy Angelov, Seiichiro Nakabayashi Iron Doped Carbon Nanodots as Efficient Electrocatalysts	123

JOURNAL OF MINING AND GEOLOGICAL SCIENCES, Vol. 61, Number 3
ISSN 2682-9525 (print)
ISSN 2683-0027 (online)
СЪДЪРЖАНИЕ
CONTENTS

Ivan Minin, Dimitar Mitev, Simeon Savov Determining the Impact of the Fraction Size of the Feeding Product and the Width of the Discharge Port of a Complex Pendulum Jaw Crusher on its Performance	5
Ivan Minin, Valerya, Kovacheva-Ninova, Dimitar Dimitrov Characteristics of the Fraction Size Distribution and the Rate of Crushing for a Laboratory-Scaled Complex Pendulum Jaw Crusher	9
Teodora Hristova, Ivan Minin, Dimitar Mitev Determining the Relative Energy Consumpton of a Jaw Crusher Depending on the Width of the Discharge Port and on the Particle Size Distribution of the Crushing Product	13
Hristo Sheiretov Comparison of the Methodologies for Determining the Cross Section of the Material on a Moving Conveyor Belt	18
Hristo Sheiretov Checking the Stability of a Truck Mounted Crane and Determining the Reaction Forces in the Supports	23
Raina Vucheva, Violeta Trifonova-Genova Determining The Diagrams of Internal Forces in a Knife on an Excavator Bucket	29
Kiril Dzhustrov Experimental Determination of a Current of Ground Connection in the Middle Voltage Network in an Opencast Mine	34
Radi Tenev Experimental Filter Tests for an Insulation Monitoring Device for it Systems	38
Ivan Prodanov, Stefan Stefanov Measurement and Calculation of the Density of the Charge of Electrified Oil Products Using the Sampling Method	44
Stefan Stefanov, Ivan Prodanov Measurement and Calculation of the Electrifying Current of Electrified Oil Products Using the Sampling Method	47
Yasen Gorbunov, Tihomir Dzhikov Signature Analysis Methods to Detect Failures in Electric Motors	50
Mila Ilieva-Obretenova Information Model for City Monitoring by Smart Lighting	55
Gergana Tonkova, Violeta Trifonova-Genova Determining the Natural Frequency on a Stepped Shaft With a Transitional Curved Section	60
Asen Stoyanov The Movement of a Point Set In Cartesian Coordinates and Studied in the Mathcad Environment	64
Kremena Arsova-Borisova, Veselin Christov Models in Designing Document Management Systems	70

JOURNAL OF MINING AND GEOLOGICAL SCIENCES, Vol. 61, Number 4
ISSN 2682-9525 (print)
ISSN 2683-0027 (online)
СЪДЪРЖАНИЕ
CONTENTS

Veselin Mitev The Bulgarian Mining Industry in 2017 – Perspectives and Forecasts	5
Valeria Kovacheva-Ninova, Valentin Velev Oil – State, Trends and Sustainable Development	11
Borislava Galabova, Nedyalko Nestorov Value Added Dynamics of the Bulgarian Mining Industry	17
Boryana Trifonova Work Motivation Factors at the Beginning of Employment in the Mining Companies	22
Borislava Galabova, Boryana Trifonova Innovative Practices in the Management of a Mining Company	25
Vessela Petrova Implementation of Certified Management Systems in Mining Companies	29
Emil Dimov, Nikola Stratiev The Investment in Cryptocurrencies: A Quest for Earnings Lost	33
Gabriela Siderova Methodology for the Assessment of the Competitiveness of a Mining Company	37
Bisser Tzolov, Vanya Tzolova Postgraduate Studies at NSA “V. Levski” as an Opportunity for Vocational Qualification and Career Development	41
Dimitrina Deliyska, Nikolay Yanev Improving Detectability and Visualization of the Website of the University of Mining and Geology „St. Ivan Rilski“	45
Svetlana Toncheva-Pencheva, Yordanka Anastasova Protection of Personal Data in E-Learning – Methodology and Technologies	51
Perihan Yusein, Milena Purvanova Difficulties in Teaching English for Special Purposes to Engineers as a Foreign Language	54
Veselina Gospodinova, Radostina Yordanova Digital Surface Modeling Suitable for the Purposes of Education in Photogrammetry	60
Nadezhda Kostova Specific Sources of Stress in Physical Education and Sports Teachers Depending on Pedagogical Experience	65
Katia Stoyanova Work In Small Groups – Theoretical and Methodological Aspects	69