THEORETICAL ANALYSIS OF INFLUENTIAL PARAMETERS TO COMPRESSION AND DECOMPRESSION PROCESS OF COMPRESSED OIL IN HYDRAULIC SYSTEMS OF THE PRESS

Compressibility of hydraulic oil is very significant for large diameter cylinder presses, especially if they are exposed to high pressures. The paper presents a theoretical analysis of the process of compression and decompression of oil in the cylinders with and without the presence of air presenting an analog model. Although considerations are relating to the ideal conditions of the process of compaction, the paper defines the basic mathematical processes depending on compression and discharge of the same. They refer to the definition of the time discharge and elimination of adverse effects in the same

INFLUENTIAL PARAMETERS DURING PRESSURE RELIEF EXPOSED IN WORKING CHAMBER OF HYDRAULIC CYLINDER PRESS

Relieving volumes, which were under pressure, with all the controls on the distribution and management of oil supply, may lead to the occurrence of the hydraulic impact, which is especially distinct in hydraulic presses. For these reasons, high speed unloading compression volume is the main cause of this phenomenon. This paper provide practical guidance for the design and calculation of important design parameters usually embedded devices - hydraulic command check valves (HCCV) (nominal size, pressure and decompression time) and the possibility of determining performance requirements using, from literature, the expressions and the nomograms

Revolucionarni teror u Novovaroškom, Prijepoljskom i Pljevaljskom srezu oktobar 1941-maj 1942

Revolutionary terror in the regions of Nova Varoš, Prijepolje and Pljevlja was developing throughout three time periods, in three directions and in three ways. Radicalization of class conflict was unfolding in the following phases: October–December 1941, December 1941–February 1942 and February–May 1942. In the course of the said periods, class conflict was directed towards three target groups. The first was “internal enemy” i. e. allegedly unreliable and hostile fighters within partisan forces and even within CPY. The second referred to all those considered as “ideological enemies” while the third one referred to the population opposing the orders of the CPY. The most frequent forms of punishment were executions (sometimes even mass) mostly without clearly determined verdict, seizure of the property, expulsion from homes and (or) burning the homes down. In that way partisans killed (sometimes in very brutal ways) more than 190 people in regions of Nova Varoš, Prijepolje and Pljevlja. Most affected by communist repression were citizens of Nova Varoš Pljevlja and its surrounding. Consequently, both the partisans movement and the CPY as its vanguard lost the support of the local population, which fought back and started turning to the Chetniks

THEORETICAL ANALYSIS OF INFLUENTIAL PARAMETERS TO COMPRESSION AND DECOMPRESSION PROCESS OF COMPRESSED OIL IN HYDRAULIC SYSTEMS OF THE PRESS

Compressibility of hydraulic oil is very significant for large diameter cylinder presses, especially if they are exposed to high pressures. The paper presents a theoretical analysis of the process of compression and decompression of oil in the cylinders with and without the presence of air presenting an analog model. Although considerations are relating to the ideal conditions of the process of compaction, the paper defines the basic mathematical processes depending on compression and discharge of the same. They refer to the definition of the time discharge and elimination of adverse effects in the same

INFLUENTIAL PARAMETERS DURING PRESSURE RELIEF EXPOSED IN WORKING CHAMBER OF HYDRAULIC CYLINDER PRESS

Relieving volumes, which were under pressure, with all the controls on the distribution and management of oil supply, may lead to the occurrence of the hydraulic impact, which is especially distinct in hydraulic presses. For these reasons, high speed unloading compression volume is the main cause of this phenomenon. This paper provide practical guidance for the design and calculation of important design parameters usually embedded devices - hydraulic command check valves (HCCV) (nominal size, pressure and decompression time) and the possibility of determining performance requirements using, from literature, the expressions and the nomograms

Sandžak: 1941-1943

У раду се на основу архивске грађе похрањене у Србији и иностранству, периодике, наративних, дневничких и меомоарских извора, као и домаће и стране научне литературе, анализирају друштвено-политичка, војна и економска дешавања на територија Санџака/Старог Раса током периода италијанске окупације. Због свог гео-стратешког положаја ово подручје је имало велику важност. На њему су се преплитали империјалистички, али и ужи интереси како држава које су разбиле Југославију – Немачке и Италије, тако и њених сателита НДХ и Велике Албаније. Немачка је била заинтересована за експлоатацију рудника „Трепча“ и обраћала је више пажње на Дежевски, Штавички и Сјенички срез. Италија је на другој страни, покушавала да преко Санџака продре у дунавски басен и учврсти балкански окупациони ланац који се пружао од Словеније до Грчке. Због оваквих војно-политичких планова посебни интереси Хрвата и Албанаца, масовно подржаних од санџачких муслимана, нису имали реалних шанси за успех. Акције квинслиншких творевина у Старом Расу показале су се међутим, једнако погубне по локални живаљ обе вероисповести, као и држање италијанског или немачког окупатора. Оне доливају уље на верске трзавице које су између хришћана и муслимана тињале столећима, распаљујући обострану мржњу до крајњих граница. То је, уз завршни додир италијанске колонијлане политике, гурнуло цео простор у безнађе масовних покоља, паљења и убијања, углавном цивилног становништва. Последња, али не и мање битна, страна свакодневнице на овом економски и социјлано врло заосталом подручју, био је идеолошки грађански рат који се водио унутар српске етничке скупине. Одани потпуно опречним државотворним програмима комунисти и ројалисти отварају разорни сукоб, бременит догађајима и процесима који су чини нам се, заувек, изменили политичку и економску слику Старог Раса.This paper analyzes social, political, military and economic affairs in the territory of Sandzak/Old Ras in the course of Italian occupation on the basis of archive material stored in Serbia and abroad, periodicals, narratives, diaries and memoirs as well as domestic and foreign scientific literature. Due to its geostrategic position, this region was of a great significance. It was the place where the imperialist interests intertwined with the special interests of not only the countries responsible for the breakup of Yugoslavia - Germany and Italy but also their satellites such as Independent State of Croatia and Great Albania. Germany paid significantly more attention to the Districts of Dezevo, Stavica and Sjenica since it was interested in exploitation of Trepca Mine. On the other hand, Italy was trying to make a way into the Danube River Basin through Sandzak and thus secure the Balkan occupational chain stretching from Slovenia to Greece. Due to these military and political plans, special interests of Croats and Albanians, massively supported by Sandzak Muslims, did not have real chances for success. However, the actions of quisling formations within Old Ras proved to be equally detrimental to the local people of both confessions as well as the activities of Italian and German occupier. They made the religious tensions existing between Christians and Muslims for centuries worse, thus sparking mutual hatred to the ultimate limits. The previously mentioned together with the final touch of Italian colonial policy pushed the entire region into hopeless mass slaughters, burning and killing of predominantly civilian population. The last but not less important aspect of daily life in this significantly stagnant area in terms of economy and social affairs was the ideological civil war led within Serbian ethnic group. Loyal to the completely opposing state-building programs, communists and royalists commenced a devastating conflict fraught with events and processes which, as it appears, forever changed the region of Old Ras politically and economically

A MULTICRITERIA DESCRIPTION OF RULES FOR PUBLIC PROCUREMENT

At an announced tender of a contracting party, in the processes of public procurement of goods or services, a method of decision-making follows after interested bidders submit bids. Such method of choice is characteristic for all business systems with majority share of state capital. Methods of decision-making come down to selecting the best bids, because mistakes in the selection should be excluded. However, in practice, the problems of a wrong choice are manifested in dissatisfaction of the bidders. The problem then causes a delay in the procurement process, and often the retrial. In order to prevent this from happening authors of this paper suggest a somewhat different methodologies in selecting the most advantageous tender to the contracting authorities. The proposed method will be the case of the of Parking service (PC) from Belgrade (service of overhaul of the devices) will show a possible way of selecting the best alternative bids, taking into account previously adopted criteria

A MULTICRITERIA DESCRIPTION OF RULES FOR PUBLIC PROCUREMENT

At an announced tender of a contracting party, in the processes of public procurement of goods or services, a method of decision-making follows after interested bidders submit bids. Such method of choice is characteristic for all business systems with majority share of state capital. Methods of decision-making come down to selecting the best bids, because mistakes in the selection should be excluded. However, in practice, the problems of a wrong choice are manifested in dissatisfaction of the bidders. The problem then causes a delay in the procurement process, and often the retrial. In order to prevent this from happening authors of this paper suggest a somewhat different methodologies in selecting the most advantageous tender to the contracting authorities. The proposed method will be the case of the of Parking service (PC) from Belgrade (service of overhaul of the devices) will show a possible way of selecting the best alternative bids, taking into account previously adopted criteria

Primena hidrostatičkog klipnog uređaja za proveru sile pritezanja i dilatacije zavrtnja pri ostvarivanju zavrtanjske veze

For the most responsible screw connections (especially those with large prestressing) it is very important to precisely define the required tightening force Fp which must not be less than the minimum necessary force Fpmin, nor greater than the maximum permissible force Fpmax . If Fp Fmax plastic deformations may occur and consequently permanent damage of some elements of screw connection.Therefore, the tightening force should be defined as precisely as possible, and then in practice it needs to be adequately measured and controlled in a screw connection. The paper presents an original laboratoryexperimental method for measuring the forces and dilatations of the screw during tightening based on the application of a special hydrostatic piston device as well as a brief description and operating principle of the device. The device was designed at the Higher Technical School of Mechanical Engineering in Trstenik and it can be used for laboratory exercises in technical schools and faculties, as well as in the industry for checking the mechanical properties of the screws before being mounted, and also for various experiments in research laboratories and institutes.Publishe