It is known that the temperature of crystallization during the synthesis of zeolite is one of the most important process parameters. However, during the research work on the synthesis of zeolite 13X and the introduction of this material into regular industrial production, it was noticed that the heating rate of the starting reaction suspension can have an equally important influence. This influence can be so pronounced that a difference of just a few minutes in reaching the crystallization temperature can make a significant difference in product quality, affect the presence of other phases in the crystal, or even determine the direction of zeolite crystallization. Therefore, the aim of this work was to show the influence of the heating rate on the quality of the obtained 13X zeolite powders. The obtained samples were analysed in terms of crystallinity (by X-ray diffraction), chemical composition, granulometry and specific surface area (by Brunauer-Emmett-Teller analysis), and regarding water and CO2 adsorption capacities. Additionally, scanning electron microscopy analysis of the samples showed the morphological characteristics of different 13X zeolite powders. The analysis results of the obtained powders confirmed the influence of the heating rate and helped to define the optimal synthesis parameters i.e. the initial temperature and heating time, that resulted in stable product quality.
This paper presents research on hydrodynamics and mass transfer in a packed absorption column. Experimental data on dry column pressure drop, flooding point, and efficiency of absorption of CO2 in water is obtained on a lab-scale absorption column packed with Raschig rings. Auxiliary parts of equipment together with chemical analyses provide simple monitoring and collecting the data. All obtained data were used to test different mathematical models for a given problem, i.e. for determination of the dry column pressure drop, flooding point and the overall gas transfer unit height. For dry column pressure drop, models developed primarily for packed columns described the data the best, with the Billet model generating a 6.54 % mean error, followed by Mackowiak and Stichlmair models. In flooding point calculations, empirical models were tested and models of Lobo, Leva and Takahshi gave the best results. Mass transfer (absorption) experiments gave expected results, since absorption efficiency increased with the increase in the liquid/gas flow rate ratio, i.e. with approaching the flooding point. The Onda?s model was used to calculate partial mass transfer coefficients in liquid and gas phases based on which the height of the overall gas transfer unit was estimated and subsequently compared with the experimental data. Deviation of calculated and experimental results for the height of the overall gas transfer unit is in the expected range of 0-20 %, with mean value of 15.5 %. In conclusion, the available models for determination of the investigated hydrodynamics and mass transfer parameters in packed absorption columns gave adequate results in comparison to the experimental values.
With the increasing participation of renewable energy sources in the production of electricity, the answer to the question of the necessary operating reserve capacity in power systems is becoming more and more complicated. The very fact of the variability of driving energy (sun, wind, water) in photovoltaic power plants, wind power plants and small hydropower plants makes the required operating reserve capacity variable. As the electric power system itself is stochastic, the inclusion of renewable energy sources in the operation of electric power systems emphasizes its stochastic characteristic even more. For this reason, the need for operating reserve in electric power systems from the aspect of renewable energy sources and with them in connection with micro-grids, is best solved using the tools of probability, that is, statistics and estimation. The issue of operating reserve in the power system was investigated by Bayesian statistics, which connects the simultaneous occurrence of a random variable (available capacity of renewable energy sources in micro-grids) with a statistical variable (load in micro-grids). The result of this research is the probability of a deficit or surplus of available energy in micro-grids, and the consequence of that probability is the probability of the need and degree of engagement of the operating reserve in the power system using system’s thermal electric power plants and/or hydro electric power plants.
Welded structures place increasing demands on the level of increased resistance to fracture. A large number of fractures of welded structures, which occur during exploitation at a stress level below of the allowable, indicates the danger of brittle fracture. The assessment of brittle fracture susceptibility was analyzed by testing Sharpy specimens, and the total impact energy, components of total impact energy (crack energy initiation and crack energy propagation) were used as parameters in the analysis.
Slovenians like new technologies. However, they hold specific fears that robots will take their working places. Robots represent opportunities for providing service as the population grows old, and robots will be needed to help old people. Especially in fields where workers are scarce, such as healthcare, knowledge of the interaction human-cobot will be needed. Robots have been present in highly supervised and stable environments for decades. Due to extreme progress in robotics, they have moved among people, in less predictable environments, and have a more human-like appearance. The purpose of our paper is to present cases of cobots in Slovenian hospitals. We use qualitative methodology. Results of our desktop research are presented. Our paper researches contemporary management challenges in healthcare. Before, and after the COVID-19 pandemic, the demand for healthcare professionals was a critical challenge as the nursing staff was overburdened. It is hard to fill all the necessary nursing positions in hospitals. The problem seems to be getting even bigger due to the growing trend of the elderly population around the world. In the theoretical part, we present the interaction between human being-robot. In the empirical part, we present three examples of the incorporation of robots in hospitals in Slovenia and expose some of the current challenges, benefits, and difficulties of working with robots.
. Water samples were collected near the thermal power plant and coal mine (Gacko, Republic of Srpska, Bosnia and Herzegovina) and analyzed to measure the concentration of 33 parameters (pH, temperature, electrical conductivity, alkalinity as CaCO 3 , total hardness as CaCO 3 , total solids, total suspended matter, dissolved oxygen, oxygen saturation, biological oxygen demand, chemical oxygen demand with permanganate, ammonia, nitrite, nitrate, P, PAH, PCBs, phenolic index, mineral oils, detergents, content of As, Cd, Cr, Fe, Mn and Pb, sulfates, chlorides, fluorides, aerobic organotrophs, total coliforms, fecal coliforms and fecal streptococci). Determined average mean pH values and EC are within the reference values for class I surface water quality. The surface water in the study area is alkaline, with a mean pH value of 8.01. Depending on the location, other analyzed parameters correspond from I to V water quality classes. The ERI for As, Cd, Cr and Pb is low and for Mn is appreciable. The RI of the surface water in location 1 and 2 were moderate. In other locations, risk coefficients are low.
Effect of methyl methacrylate (MMA) as a binder and heating treatment were investigated to improve green alumina compacts machinability. Properties of green compacts and their corresponding sintered samples prepared with and without MMA were compared. Investigation of green and sintered properties was performed on samples compacted at applied pressures up to 150 MPa. After pressing, samples with MMA were thermally treated at 115oC. The intention was to enhance the polymerization of MMA at a temperature a little higher than the glass transition temperature (Tg = 103oC) of poly (methyl methacrylate). Green compacts with MMA had higher green density values than those without MMA. Sintered samples with MMA had lower values of sintered density and higher values of total porosity; after sintering, relative linear shrinkage was around 15 % for the whole range of applied pressures. The possibility of easily machining the green compacts with MMA produces great possibilities for application in many fields
Background: A laboratory professional concerned with the quality of work in medical-biochemical laboratories ensures the accuracy and precision of laboratory analyses through the implementation of international and European guidelines for working with hazardous substances, through the availability and implementation of Standard Operating Procedures (SOPs). Laboratory hazards that affect the concentration and safety of workers arise from laboratory deficiencies such as: lack of preventive measures, knowledge and skills implemented through SOPs and good laboratory practice. Biophysical hazards in medical laboratories are manifested by needles and sharp objects, infectious materials, noise, vibration, radiation, poor air quality, temperature inversions. Objective: The aim of the research was to raise awareness of the quality of work in medical-biochemical laboratories in order to ensure the safety of workers. Methods: A cross-sectional questionnaire-based study was conducted among 100 laboratory professionals from Bosnia and Herzegovina (BiH) and Croatia. The research was conducted over a period of three months. Results: A higher percentage of exposure to infectious agents and needles and sharp objects was found among respondents from BiH compared to CRO (p=0.018 and p=0.001, respectively). We found that respondents employed in accredited laboratories are aware of exposure to hazards in a high percentage related to infectious agents, toxins (p=0.0012 and p=0.0046, respectively). A significant statistical difference was found between respondents with BiH and respondents with CRO in terms of knowledge of accreditation standards of medical-biochemical laboratories (p=0.0155). Respondents who have standard operating procedures available are aware of the hazards of infectious agents (p=0.0001), toxins (p=0.0466), needles and sharp objects (p=0.0052), noise (p=0.0030), vibration (p=0.0007) and extreme temperatures (p=0.0014). Conclusion: Efficient implementation and continuous compliance with the ISO 15189: 2018 standard requires constant commitment and active participation of laboratory staff. Laboratories must have standard operating procedures in place and actively monitor their use.
Knjiga “Stanje tradicionalnih znanja o biodiverzitetu u Bosni i Hercegovini” predstavlja sveobuhvatno istraživanje koje se fokusira na važnost očuvanja tradicionalnih znanja i praksi lokalnih zajednica u kontekstu zaštite biodiverziteta i održivog razvoja. Autori knjige pružaju detaljan pregled različitih aspekata tradicionalnih znanja, uključujući upotrebu biljaka, životinja i prirodnih resursa, kao i načine na koje su lokalne zajednice kroz generacije prenosile ta znanja i vještine. Ova publikacija naglašava važnost uključivanja tradicionalnih znanja u suvremene strategije zaštite biodiverziteta i očuvanja prirode. Kroz brojne primjere i studije slučaja, knjiga ilustruje kako ova znanja mogu doprinijeti očuvanju biološke raznolikosti, prilagodbi na klimatske promjene i promociji održivih lokalnih zajednica. Također ističe potrebu za jačanjem suradnje između naučnih istraživača, donositelja odluka i nositelja tradicionalnih znanja, kako bi se osigurao holistički pristup zaštiti prirode.
Aim: To present a very rare case of empyema cavuma septi pellucidi. Case report: A 5-year-old male child was admitted to the Department of Infectious Diseases Cantonal Hospital Zenica because of fever (38.30C), headache and vomiting. The patient developed intracranial hypertension as a result of a compressive purulent collection formed due to meningitis between the lamine of the septum pelucidum with consequent intracranial hypertension. Conclusion: The decision regarding the modality of treatment was not easy. We considered that empyema evacuation using the transcallosalinterhemispheric approach allows the complete removal of purulent collection and the placement of drainage, which allows additional emptying of the empyema cavity and prevents empyema recurrence. Empyema evacuation with drainage and antibiotic therapy have shown beneficial results.
The main MoR discussion led to further suggestions on KE terminology, including ensuring coherence to directionality in terms of the KE descriptions (e.g., specifying increase, decrease, altered, no direction, etc.) and clarifying differences in ROS and reactive oxygen and nitrogen species (RONS), and enzymatic and non-enzymatic events. The consortium highlighted the importance of the role of ROS as a KE and an associative event in the AOP framework. Additionally, participants highlighted modification to macromolecules from the resultant RONS generation (e.g., lipid peroxidation) as a relevant endpoint to include in the KE. The possibility of grouping ROS-related KEs in the AOP framework needs to be discussed further.
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