Evolution of clock escapement mechanisms

Rad prikazuje i objašnjava konstruktivne detalje evolucije zaprečno-impulsnih mehanizama časovnika kroz vekove. Kao posebno značajni, istaknuti su sledeći mehanizmi: krunski točak, vreteno i balansna poluga, kotvene zaprečnice sa povratnim trzajem, mirne, slobodne, a posebno njihove podvrste - gravitacione i hronometarske zaprečnice, kao i engleske i švajcarske zaprečnice sa ankerom. Objašnjena su sva bitna geometrijska, kinematska i dinamička svojstva pobrojanih grupa mehanizama, kao i uticaj tih svojstava na ravnomernost hoda časovnika.The paper presents and explains the evolution of details design of the clock escapement mechanisms through the ages. As particularly significant, the following mechanisms are emphasized: the crown wheel (verge & foliot), anchor recoil, deadbeat and detached escapements, and their variations - gravity and chronometer escapements, as well as the English and Swiss lever watch escapements. All important geometrical, kinematical and dynamical properties and the influence of these properties on the clock accuracy are explained

Plasma-Activated Medium Potentiates the Immunogenicity of Tumor Cell Lysates for Dendritic Cell-Based Cancer Vaccines

Autologous dendritic cells (DCs)-based vaccines are considered quite promising for cancer immunotherapy due to their exquisite potential to induce tumor antigen-specific cytotoxic T cells. However, a lack of efficient protocols for inducing immunogenic tumor antigens limits the efficacy of DC-based cancer vaccines. Here, we found that a plasma-activated medium (PAM) induces immunogenic cell death (ICD) in tumor cells but not in an immortalized L929 cell line or human peripheral blood mononuclear cells. PAM induced an accumulation of reactive oxygen species (ROS), autophagy, apoptosis, and necrosis in a concentration-dependent manner. The tumor lysates prepared after PAM treatment displayed increased immunogenicity in a model of human monocyte-derived DCs, compared to the lysates prepared by a standard freezing/thawing method. Mature DCs loaded with PAM lysates showed an increased maturation potential, as estimated by their increased expression of CD83, CD86, CD40, IL-12/IL-10 production, and attenuated PDL1 and ILT-4 expression, compared to the DCs treated with control tumor lysates. Moreover, in co-culture with allogeneic T cells, DCs loaded with PAM-lysates increased the proportion of cytotoxic IFN-γ+ granzyme A+ CD8+ T cells and IL-17A-producing T cells and preserved the Th1 response. In contrast, control tumor lysates-treated DCs increased the frequency of Th2 (CD4+IL-4+), CD4, and CD8 regulatory T cell subtypes, none of which was observed with DCs loaded with PAM-lysates. Cumulatively, these results suggest that the novel method for preparing immunogenic tumor lysates with PAM could be suitable for improved DC-based immunotherapy of cancer patients

High slope waste dumps – a proven possibility

This paper is an overview of dumping operations on High Slope Waste Dump at Veliki Krivelj open pit copper mine, RTB Bor, Serbia. The High Slope Waste Dump in Bor is the highest single slope waste dump in the world with the slope height of 405 m. The paper gives the basics and limitations of the designed dumping technology, the redesigned technology, gives an overview of the 13 year long operation and gathered experiences and addresses the main issues of dumping operations in high slope conditions as well as the present condition of the High Slope Waste Dump

Unmanned aerial systems as a revolutionary tool in modern armed conflicts

More than a century has passed since the third dimension of space (airspace) has become an important place where combat and non-combat activities take place. The ability of the Air Force to carry out a wide range of content of combat operations and other activities from the airspace ensured the development of new qualitative characteristics of modern armed conflicts. The absence of physical limitations, high maneuverability and dynamism, short reaction time, as well as the high intensity of actions carried out by the Air Force, have enabled these forces to have strategic importance in armed conflicts since the Second World War. In parallel with the development of civilization and the emergence of qualitatively new technologies, rapidly improved technological solutions are being developed, which are changing the way of life of people around the world, improving it literally day by day. Each technological generation brings a new level of civilizational development, leading to the symbiosis of man as a human being and modern technical and technological means. Undoubtedly, this is also the case with the development of modern weapon systems and equipment used in armed conflicts. This is also the case with the revolutionary development of new weapon systems in air forces around the world. The development of modern weapons in the air force is best seen through the development of unmanned aerial platforms (unmanned aerial vehicles). The development of these assets is a consequence of the industrial revolution of the fourth generation and the importance of these platforms in the realization of tasks in modern armed conflicts is almost immeasurable. Namely, every conflict brings exponential development of these assets, both in technical and tactical sense. The development of these means in modern armed conflicts is a continuous process that is realized on the basis of previous experiences from the tactical use of unmanned aerial vehicles in concrete combat actions. There is no doubt that the technological progress of these means is something that in the future will enable the almost unlimited use of these aircraft in the execution of a wide variety of tasks without minimal danger to human life. This paper, whose main goal is to describe the unmanned aerial vehicle as a tool for the execution of a wide range of tasks in an unlimited war format, consists of three chapters in addition to the introduction and conclusion. In the first chapter, the theoretical determination of the unmanned aerial vehicle as a weapon-equipment system was made. In the second chapter, the use of unmanned aerial vehicles is analyzed on the examples of armed conflicts in Syria and Nagorno-Karabakh. In the third chapter, an analysis of potential aviation patterns of unmanned aerial vehicles and loitering munition (also known as a suicide drone or kamikaze drone) in combat operations was carried out

Laser inspection of rubber profiles

In the rubber industry, especially in the tire branch, inspection of shape and dimensions of freshly extruded rubber profiles which are components of a final product is an important problem. Accuracy of shape and dimensions of these profiles largely defines the quality of final product. Reviewed in this paper are existing solutions and inspection technologies which are in use for this type of problem. Proposed in this paper is a novel solution for the inspection of shape and dimensions which performs on a par with existing methods, while providing simplicity and cost effective design. The proposed solution employs a two-dimensional movement of a simple laser beam, which measures the distance rather than the laser plane whose reflected traces are analyzed as an image

Laser inspection of rubber profiles

In the rubber industry, especially in the tire branch, inspection of shape and dimensions of freshly extruded rubber profiles which are components of a final product is an important problem. Accuracy of shape and dimensions of these profiles largely defines the quality of final product. Reviewed in this paper are existing solutions and inspection technologies which are in use for this type of problem. Proposed in this paper is a novel solution for the inspection of shape and dimensions which performs on a par with existing methods, while providing simplicity and cost effective design. The proposed solution employs a two-dimensional movement of a simple laser beam, which measures the distance rather than the laser plane whose reflected traces are analyzed as an image

Antioxidant variability of wheat genotypes under salinity stress in situ

Crop cultivation under the open-field conditions depends on a variety of biotic and abiotic factors which cause plant stress and deterioration. Due to high soil salinity, some soils can be an unfavourable growing environment for most plants. As a low productivity soil type, solonetz soils are a stressful growing environment, causing plant deterioration. Plants have developed a complex antioxidative defense system as a precaution against oxidative stress caused by high soil salinity. The trial was set up on a halomorphic soil type-solonetz. The research included ten cultivars, one local population of hexaploid wheat (Triticum aestivum ssp. aestivum L.) and one cultivar of triticale (Triticosecale W.). The activity of enzymatic and non-enzymatic antioxidants in plant antioxidative defense system was detected during the trial, as well as lipid peroxidation. The analysis of biochemical markers was done in the flowering stage, and then in the milk maturity phase. Research results of the tested components revealed the highest stress tolerance exhibited by genotypes Banatka and Bankut 1205. Understanding the process of oxygen radical production by the plant tissue contributes to breeding wheat cultivars for better stress tolerance. Selection of genotypes better adapted to growing conditions in solonetz soils could facilitate a more economically justifiable wheat production, and promote utilization of the lower-quality soil types in agriculture

Influence of furnace tube shape on thermal strain of fire-tube boilers

The aim of this paper is to use numerical analysis and fine element method-FEM to investigate the influence of furnace tube shape on the thermal strain of fire-tube boilers. Thermal stresses in corrugated furnace tubes of different shape, i.e. with different corrugation pitch and depth, were analysed first. It was demonstrated that the thermal stresses in corrugated furnace tube are significantly reduced with the increase of corrugation depth. Than deformations and stresses in the structure of a fire-tube boiler were analysed in a real operating condition, for the cases of installed plain furnace tube and corrugated furnace tubes with different shapes. It was concluded that in this fire-tube boiler, which is of larger steam capacity, the corrugated furnace tube must be installed, as well as that the maximal stress in the construction is reduced by the installation of the furnace tube with greater corrugation depth. The analysis of stresses due to pressure and thermal loads pointed out that thermal stresses are not lower-order stresses in comparison to stresses due to pressure loads, so they must be taken into consideration for boiler strength analysis

Smoking habits, knowledge about and attitudes toward smoking among employees in health institutions in Serbia

Background/Aim. According to the number of active smokers, Serbia occupies a high position in Europe, as well as worldwide. More than 47% of adults are smokers according to WHO data, and 33.6% according to the National Health Survey Serbia in 2006. Smoking physicians are setting a bad example to patients, they are uncritical to this habit, rarely ask patients whether they smoke and rarely advise them not to smoke. These facts contribute to the battle for reducing the number of medical workers who smoke, as well as the number of smokers among general population. The aim of the study was to determine the smoking behavior, knowledge and attitudes and cessation advice given to patients by healthcare professionals in Serbia. Methods. A stratified random cluster sample of 1,383 participants included all types of health institutions in Serbia excluding Kosovo. The self administrated questionnaire was used to collect data about smoking habits, knowledge, attitudes and cessation advice to patients given by health professionals in Serbia. Results. Out of 1,383 participants, 45.60% were smokers, of whom 34.13% were physicians and 51.87% nurses. There were 46.4% male and 45.4% female smokers. The differences in agreement with the statements related to the responsibilities of health care professionals and smoking policy are significant between the “ever” and “never” smokers, and also between physicians and nurses. Twenty-five percent of nurses and 22% of doctors claimed they had received formal training. However, only 35.7% of the healthcare professionals felt very prepared to counsel patients, while 52.7% felt somewhat prepared and 11.6% were not prepared at all. Conclusions. According to the result of this survey, there are needs for more aggressive nationwide non-smoking campaigns for physicians and medical students. Experiences from countries where physicians smoke less and more effectively carry out smoking cessation practices need to be shared with Serbian physicians in order to improve their smoking behavior and smoking cessation practices. [Projekat Ministarstva nauke Republike Srbije, br. 43012

The variation of yield components in wheat (Triticum aestivum L.) in response to stressful growing conditions of alkaline soil

The paper presents the results of experiments with 11 varieties of wheat grown in alkaline soil stressful conditions. The experiment was set up at the site in the Banat, on the non-ameliorated solonetz soil, as control variante, and with ameliorative measures using phosphogypsum. The phenotypic variability and genotype by environment interaction for the grain number and weight per spike, using AMMI model in three vegetation seasons were studied. The analysis of the results revealed that the tested varieties responded differently to external, stressful conditions and ameliorative measures. Based on the AMMI analysis results the significance of PCA axis was observed