Dejan Krstev | Univerzitet Goce Delcev (original) (raw)

Papers by Dejan Krstev

Рециклирањето на индустрискиот отпад и електронскиот отпадсе круцијален проблем во идните совреме... more Рециклирањето на индустрискиот отпад и електронскиот отпадсе круцијален проблем во идните современи технологии ширум светот.Потребата за метали, развојот на индустриите и огромните потреби одметали за индустријата се предизвик при изнаоѓањето на технологии заупотребливи отпади за преработка и производство на метали и другиматеријали. Индустрискиот отпад (сите примероци на индустрискиотпади), особено електронскиот отпад, се можни и соодветни „суровиматеријали” за иднината. Во овој труд ќе бидат прикажани новите трендовии перспективи за повторна употреба на отпадните материјали како можниресурси за добивање и производство на корисни метали и материјали

Knowledge International Journal, 2019

There is no question that business, education, and all fields of science have come to rely heavil... more There is no question that business, education, and all fields of science have come to rely heavily on the computer. This dependence has become so great that it is no longer possible to understand social and health science research without substantial knowledge of statistics and without at least some rudimentary understanding of statistical software. The number and types of statistical software packages that are available continue to grow each year. In this paper we have chosen to work with SPSS, or the Statistical Package for the Social Sciences. SPSS was chosen because of its popularity within both academic and business circles, making it the most widely used package of its type. SPSS is also a versatile package that allows many different types of analyses. transformations, and forms of output - in short, it will more than adequately serve our purposes. The SPSS software package is continually being updated and improved, and so with each major revision comes a new version of that p...

In this paper the descriptive statistics of the obtained results in the selective galena and spha... more In this paper the descriptive statistics of the obtained results in the selective galena and sphalerite flotation from the Sasa mine, Macedonia will be shown. The consumption of the flotation reagents, bails and rods grinding media in the flotation flowsheet, lead and zinc feed contents, lead and zinc concentrate contents, the appropriate recoveries of the mentioned minerals with estimation of the correlation for reagents regime, recoveries, contents in the lead and zinc feeds and concentrates, based on the descriptive statistics or Excel- solver computer presentation.

In this paper will be shown the general concept of the techno-economical development in Western B... more In this paper will be shown the general concept of the techno-economical development in Western Balkan countries (esspecialy in R.Macedonia), as a result of the closed privatization and including the direct investment in the field of education, economy and other parts of interest. An explination of the state and public legislative in the high education (Bologna, EKTS, Curriculum of Business Informatics, Informatics and IS, Business Logistics), the economy standards and laws, forcasting of new technologies, environmental aspects, production of health foods

Natural Resources and Technology, 2014

In a world that’s continuously moving forward, everyone is working to create the next up-and-comi... more In a world that’s continuously moving forward, everyone is working to create the next up-and-coming product with long life. Beyond cars and gadgets, the race for the greatest new technology is a constant challenge in the recycling industry. Many enterprises, companies, scientists, and environmental groups are working to construct better recycling processes and machines, as well as create new systems for previously non-recyclable materials. In the Balkan countries, recycling technology is a new direction in decision of obtaining new possibility for better future using secondary materials and other raw materials. In this paper will be present current and recent activities for recycling technology.

In this paper mathematical methods and optimization tools that make possibilities for appropriate... more In this paper mathematical methods and optimization tools that make possibilities for appropriate, fast and sure presentation of some complex circuits in the mineral processing technologies will be shown. Lagrange multipliers include the analytical methods of optimization, the constraints that appear in the form of equations. Such methods of optimization, in principle, determine or define the possible location of optimum, only stationary points, while discontinuous and border points must specifically to explore. The nature of stationary points are then examined using the conditions satisfied, whenever possible. In any particular case must be made mutually comparing the values of all local optimumi to obtain the final optimum. Lagrange multipliers represent a simple procedure, which found great use in solving problems in the field of optimization.

In this paper the application and the rote of information systems and technologies in production ... more In this paper the application and the rote of information systems and technologies in production processes in the EU members countries and candidates members for EU will be shown. In modern conditions the successful implementation of goals and objectives of the enterprise depends on its effective use of information resources. Information resources are the basis for activities of enterprises in EU, they define their strategic success. Information support of the enterprise depends not only on the availability of information resources and opportunities and implementation of information innovation, streamline information flows of the company, the issues of its effective information interaction with market players as Bulgaria, Ukraine, Macedonia, Serbia, Croatia etc.

The logistics is the science which is based on the investigations in the fields with support for ... more The logistics is the science which is based on the investigations in the fields with support for system functionality with simple aim to realize their goals, functions and operations. It’s multi-disciplinarity area which provide the knowledge and realization of the approaching in: Information technologies, Operation investigations, System theory, Management theory and organization etc. In the trend of the modern operativity it’s known that logistics is the suma of activities which have had an aim to deal faster, better, more quality Just in time. The logistics consist increasement of working efficiency with acceleration of the circulation of the the working means. This aim is realized by two ways: with decreasing of the average arranged time and by decreasing of the average suma of the arranged means The logistics as a dealing function has accepted all needed deals with complex preparation and realization of the place and time transformation for the goods and knowledges. The logisti...

Bargala is one of the most important antic town in Macedonia which name ethimology connect with B... more Bargala is one of the most important antic town in Macedonia which name ethimology connect with Bregalnica River. This town is located 12 km west-eastern from Stip town among the Kozjacka River below the Plackovica mountain. Web-page for Bargala is unique way to represent and show what is Macedonia, what is history and civilization by centuries earlier. Basic colour which is set on the back is aproximatively dark brown (#1D1A15) and used combination with red colour (#9D1014). The dimension of the Web-page is 900 px (width) and 680 px (height). In the upper part are shown eight separately squares: Start, Position, History, Artefacts, Galery, Panorama, Exacavated objects and Contact. All of them are programmed.

The refractory or low grade lead/zinc domestic ores in Republic of Macedonia are investigated by ... more The refractory or low grade lead/zinc domestic ores in Republic of Macedonia are investigated by conventional separation technology or flotation separation. In the mean time, investigations are directed to the new possibilities of leaching by microorganisms – bioleaching. The paper is result of these technologies and investigations carried out for recovery of in the mentioned ores. Using Simplex EVOP and computer program Multisimplex performances are appropriate and most acceptable and excellent way for presentation of the leaching and bioleaching.

To improve kinetic flotation models, many first-order flotation kinetics models with distribution... more To improve kinetic flotation models, many first-order flotation kinetics models with distributions of flotation rate constants were redefined so that they could all be represented by the same set of three model parameters. As a result, the width of the distribution become independent of its mean, and parameters of the model and the curve fitting errors, became virtually the same, independent of the chosen distribution function. In our case, investigations of the chalcopyrite ores are carried out using the Classical model, Klimpel Model and Fully mixed model. According to the experimental results obtained in laboratory, the Classical model is most appropriate for presentation of kinetic flotation, especially by means of MATLAB modeling.

- Logistics management information system is essential to provide management with the knowledge t... more - Logistics management information system is essential to provide management with the knowledge to exploit new markets, make changes in the design of packaging, make a right choice in store to raise or reduce inventory, to determine the profitability of customers and establish profitable level of customer service, choose transporter and determine which system of processing orders will be automated. To bring these strategic decisions management must know how you are changing costs and revenues dependent on appropriate alternatives would be selected. An advanced system for order processing is able to provide much information to different departments in the organization. Terminals for access to data can be made available to logistics management, production and marketing department. The system can provide a variety of regular reports and reports on the current situation upon request. The design of logistics information systems begins by examining consumer needs and determination of stan...

In this paper will be shown the role of information systems and technologies in production proces... more In this paper will be shown the role of information systems and technologies in production processes in the EU members countries and candidates members for EU. In modern conditions the successful implementation of goals and objectives of the enterprise depends on its effective use of information resources. Information resources are the basis for activities of enterprises in EU, they define their strategic success. Information support of the enterprise depends not only on the availability of information resources and opportunities and implementation of information innovation, streamline information flows of the company, the issues of its effective information interaction with market players. Information support of the enterprise depends not only on the availability of information resources and opportunities and implementation of information innovation, streamline information flows of the company, the issues of its effective information interaction with market players as Bulgaria, Ukr...

The MTSP is a generalization of the traveling salesman problem where there are multiple vehicles ... more The MTSP is a generalization of the traveling salesman problem where there are multiple vehicles and a single depot. In this problem, instead of determining a route for a single vehicle, we wish to construct tours for all M vehicles. The characteristics of the tours are that they begin and end at the depot node. Solution procedures begin by “copying” the depot node M times. The problem is thus reduced to M single-vehicle TSPs, and it can be solved using either the nearest neighbor or Clark and Wright heuristics. The classic VRP (Vehicle Routing Problem) expands the multiple traveling salesman problem to include different service requirements at each node and different capacities for vehicles in the fleet. The objective of these problems is to minimize total cost or distance across all routes. Examples of services that show the characteristics of vehicle routing problems include different Services deliveries, public transportation “pickups” for the handicapped, and the newspaper deli...

Not long ago, before the advent of cable operators, here in Macedonia, especially in the smaller ... more Not long ago, before the advent of cable operators, here in Macedonia, especially in the smaller towns in this area in the developed countries was overwhelming. In Shtip were able to follow only two or three programs in the Macedonian Television. Later, in the nineties of the last century, there have been two more programs to private local television stations. Admission to these programs is done through external antennas. Nevertheless, due to the specific configuration of the terrain and tall buildings, it was not possible quality reception of TV programs in all parts of the city. On the other hand, this way of receiving television programs by external antennas (and several antennas for each family) and brings other problems. Among other things, in terms of aesthetic appearance of buildings resembling a "forest" of antennas. With the advent of cable operators, this picture changes significantly. At the beginning of its development, the cable operators only offered a servic...

The refractory or low grade copper chalcopyrite ores or galena/sphalerite domestic ores in Republ... more The refractory or low grade copper chalcopyrite ores or galena/sphalerite domestic ores in Republic of Macedonia are investigated by conventional copper flotation and selective flotation for galena/sphalerite. In the meantime, investigations are directed to the new possibilities of leaching by microorganisms – bioleaching. The paper is result of these technologies and investigations carried out for recovery of in the mentioned ores. Using Simplex EVOP and computer programme. Multisimplex the tabular and especially graphic performaces are most acceptable and excellent way for presentation of the leaching and microorganisms – bioleaching.

The improvement in the chalcopyrite copper Bucim mine are gone forward to renewed reagent regime,... more The improvement in the chalcopyrite copper Bucim mine are gone forward to renewed reagent regime, including and involving new reagents for increase d recovery of copper and gold. The optimization and mathematical linear models using gradient method Box and Wilson are good example for improvement of industrial recoveries in flotation circuit. In this paper is shown optimization techniques, formatting the mathematical model and adequate model for carried out investigations. Tables and figures will show the optimal quantity in reagent regime (collectors), particle size, flotation time I rougher flotation, conditioning time etc.

Knowledge International Journal, 2019

Natural Resources and Technology, 2014