Discovery of uranium mineralizations in the rhyolite-granite complex in the Jabal Eghei area of southern Libya

During investigation of the Jabal Eghei area in southern Libya and the production of geological maps at a scale of 1:250 000 (Tibesti sector, sheet Wadi Eghei NF 34-1 and NF 34-2), regional prospecting for mineral raw materials was performed. Radiometric survey of observed targets at the sites indicated two significant uranium mineralizations in rhyolites, and some smaller ones in granites that are in close contact with rhyolites. Rhyolites are located in the central part of the investigated region. They cut through granite rocks. The first mineralization is in the central part of the rhyolite region, which is mostly composed of silificated rhyolites. The second one was discovered near the granite-rhyolite contact zone, characterized by the presence of silicified breccia rocks. These findings were confirmed by laboratory measurements of more than seventy samples collected in the area, using high resolution gamma-ray spectrometry. The concentrations of uranium in these mineralizations were found to range from approx. 50 mg kg-1 to more than 600 mg kg-1. The latter value is about 240 times above the Earth’s average. Besides uranium, these measurements have also given concentrations of thorium and potassium. Additional geochemical analysis was performed on samples taken from locations where uranium anomalies were discovered using ICP-MS technique, in which concentrations of more than forty elements were determined. Uranium mineralizations are accompained by increased contents of silver (up to 17 times), arsenic (up to 8 times), molybdenum (up to 50 times), mercury (up to 9 times), and lead (up to 14 times), in regard to the Clark’s values. These results warrant a continued investigation of this region because of potential interest in the discovery of nuclear mineral raw materials

Prirodni radionuklidi u mahovinama iz istočne Srbije u razdoblju 2008.-2013.

The results of the study on natural radionuclide content in 102 samples of the moss species randomly collected in 2008-2013 at 30 locations of eastern Serbia are presented in the paper. The activity concentration values of 238U, 226Ra, 232Th, 40K, and 7Be determined by gamma spectrometry were within the intervals: 238U (1.1–50) Bq kg-1, 226Ra (1.1–41) Bq kg-1, 232Th (1.4–28) Bq kg-1, 40K (64–484) Bq kg-1 and 7Be (88–227) Bq kg-1, not standing out of the average data reported for this region. The distribution of the obtained data for 226Ra, 232Th, and 238U activity concentration in the analysed mosses has shown values up to 10 Bq kg-1 with frequencies 47.1 %, 54.9 % and 48.0 %, respectively. The obtained activity concentration values of primordial 40K and cosmogenic radionuclide 7Be were up to 500 Bq kg-1 and about 90 % of all the results for 7Be uptake by mosses were in the 200-250 Bq kg-1 concentration range.U radu su prikazani rezultati ispitivanja sadržaja prirodnih radionuklida u 102 uzorka mahovine prikupljene metodom slučajnoga uzorka u razdoblju 2008.-2013. na 30 lokacija u istočnoj Srbiji. Vrijednosti koncentracija (specifične aktivnosti) radionuklida 238U, 226Ra, 232Th, 40K i 7Be, određene primjenom spektrometrije gama zračenja, nalaze se u opsegu: 238U (1,1 – 50) Bq kg-1, 226Ra (1,1 – 41) Bq kg-1, 232Th (1,4 – 28) Bq kg-1, 40K (64 – 484) Bq kg-1 i 7Be (88 – 227) Bq kg-1 te ne odstupaju značajno u odnosu na ostale rezultate dobivene za ovu regiju. Distribucija dobivenih podataka o koncentracijama 238U, 226Ra i 232Th u analiziranoj mahovini pokazuje vrijednosti do 10 Bq kg-1, s učestalošću 54,9 %, 48,0 % i 47,1 %. Dobivene vrijednosti koncentracija primordijalnoga 40K i kozmogenoga 7Be bile su do 500 Bq kg-1, pri čemu je oko 90 % svih rezultata za 7Be akumuliranog u mahovinama bilo u opsegu koncentracija 200 – 250 Bq kg-1

Educational value of the history of science content

Osamdesetih godina prošlog veka američki naučni odbor je istakao neraskidivost veze između razvoja nauke i razvoja tehnologije. S obzirom na tehnološki napredak društva u kojem živimo, učenici se u školama moraju osposobljavati za razumevanje tehnoloških inovacija i njihovog uticaja na kvalitet života, kao i za kritičko procenjivanje društvenih pitanja koja obuhvataju posledice razvoja tehnologije [1]. Da bi razumeli nauku i tehnologiju savremenog i budućeg doba, učenici treba da razumeju razvoj nauke i tehnologije u prošlosti. Na primer, kroz odgovarajuće epizode iz istorije prirodnih nauka, učenici mogu sagledati kako tehnologija traži odgovore nauke da bi se razvijala ili, kako se razvijala sposobnost čoveka da uoči problem koji je značajan za istraživanje i čije rešavanje doprinosi razvoju nauke, a samim tim i tehnologije. U ovom radu se govori o potencijalima sadržaja istorije prirodnih nauka za obrazovanje i vaspitanje učenika. Razmatra se uticaj sadržaja iz istorije prirodnih nauka na razumevanje pojmova iz savremenih prirodnih nauka, kao i uticaj na razvoj psiho-fizičkih sposobnosti i formiranje pogleda na svet kod učenika.In the eighties American Scientific Committee noted the connection between the development of science and technology. Because of the technological advancement of modern society, students in schools must be trained to understand the technological innovations and their impact on quality of life, as well as a critical evaluation of the social issues that include the effects of technology development [1]. To understand the science and technology of modern and future times, students need to understand the development of science and technology in the past. For example, through appropriate episodes from the history of science, students can see the relation between technology and science, and their influence on the ability of man to detect a problem that is significant for the study. The impact of the history of science content on student understanding of the concepts of modern science, and development of their skills and view of the world are examined in this paper.Prvi naučni simpozijum sa međunarodnim učešće

Functionalization of academic content concerning carboxylic acids

Istraživanja [1, 2, 3, 4] su pokazala da se učenici srednjih škola suočavaju s problemima u učenju gradiva organske hemije, posebno s primenom ovih znanja u različitim kontekstima. Jedan od osnovnih uzroka je sama koncepcija nastave organske hemije, koja se prvenstveno svodi na izlaganje akademskih znanja u gotovom vidu [2, 3]. U situacijama kada se učenicima prenosi obimno i kompleksno gradivo, najčešće motivacija za učenje nije velika. Akademska znanja iz organske hemije nisu od velikog značaja učenicima, ukoliko oni ne uviđaju kako mogu da ih iskoriste za unapređivanje kvaliteta svakodnevnog života i pripremu za bavljenje budućom profesijom [1, 3, 4]. Da bismo utvrdili da li izlaganje gradiva organske hemije u kontekstu svakodnevnog života i različitih profesija može da doprinese poboljšanju učeničkih postignuća i funkcionalizaciji stečenih znanja, sproveli smo pedagoški eksperiment sa paralelnim grupama, sa učenicima trećeg razreda gimnazije prirodnomatematičkog smera, u kome je ovaj inovativni pristup nastavi iskorišćen za obradu nastavne teme Karboksilne kiseline i njihovi derivati. Utvrdili smo da primena ovog pristupa dovodi do statistički značajnog poboljšanja učeničkih postignuća i njihove sposobnosti za primenu stečenih znanja iz ove oblasti organske hemije u različitim životnim kontekstima.Research [1, 2, 3, 4] has indicated that high school students have problems related to the learning of organic chemistry content, particulary problems associated with the application of acquired knowledge in a variety of contexts. One of the main causes of this problem is the very conception of organic chemistry courses, which are primarely based on transmission of academic content [2, 3]. In situations where students are exposed to an extensive and complex teaching material, their motivation for learning usually isn’t high. Furthermore, academic content of organic chemistry is not relevant to students, if they are not aware of how they can use it to improve the quality of their everyday life, or whether mastery of this content is important for their future professions [1, 3, 4]. To determine whether teaching organic chemistry in the context of everyday life, different professions and historical context, can help to improve student achievement and functionalization of acquired knowledge, we have conducted a pedagogical experiment with parallel groups of third grade mathematics and science orientation gymnasium students. This innovative approach was used for teaching about carboxylic acids and their derivates. We found that the application of this approach leads to a statistically significant improvement in student achievement and their ability to apply the acquired organic chemistry knowledge in a variety of contexts.Prvi naučni simpozijum sa međunarodnim učešće

Leaching kinetics of Cs+ and Co2+ under dynamic conditions

The possibility of retaining Cs+ and Co2+ bound by immobilization processes in the cement matrix is defined as the subject of its investigation: the cement matrix formulation, the water/ cement ratio, the amount of waste, and the porosity of such a structure. Implementing the standard leaching method by Hespe the possibility of comparing different authors’ results was achieved. Diffusion and semi-empirical model were used to investigate the transport phenomenon in order to predict the leaching level for a long period of time. Leaching of Co2+ and Cs+ ions under dynamic conditions immobilized in the cement matrix dynamic conditions decreases with the increase of the sludge content, regarding porosity increase. The effects of the diffusion and surface washing are equalized, and the contribution ofthe matrix dissolution to the Cs + and Co2+ transport in the cement porous media increases, on average, for one order of magnitude. The semi-empirical model gives a better approximation for Co2+ and Cs+ leaching process for the duration ofthe experiment while both models significantly approximate leaching results in dynamic conditions. © 2019, Vinca Inst Nuclear Sci. All rights reserved

One numerical method for determining the absorbed dose of gamma and X radiation in the ZrO2 dielectric within the MOS capacitor

At present, advanced microelectronics devices with Metal-Oxide-Silicon (MOS) structures are used to improve the functional characteristics of devices used in nuclear technology, radiation dosimetry and radiation protection in aerospace engineering, nuclear industry and radiotherapy equipment. Among other things, it is often the goal of new research to find new materials for the dielectric oxide such as of zirconium oxide (ZrO2) with higher dielectric constant (high-k) and testing its characteristics in an environment with radioactive radiation. The paper presents the application of a numerical method for the determination of the absorbed dose of gamma and X radiation in the dielectric thin layer of zirconium oxide, which is located in the structure of the MOS capacitor. The relation on the basis of the numerically calculated absorbed dose of radiation is obtained by using the theory of the physical transport of photons in a thin layer of dielectric. In doing so, it is necessary to know the spatial dependence of the photon flux of gamma or X-ray in a volume of the dielectric, as well as the values of the total mass attenuation coefficient and total energy absorbed mass coefficient for ZrO2 as a radiation characteristic of the material from which is made a dielectric. Based on the results of our research, it can be concluded that ZrO2 has satisfactory radiation characteristics as an alternative to the selection of dielectrics in MOS structures that are incorporated in dosimeters and radiation monitors.VII International Conference on Radiation in Various Fields of Research : RAD 2019 : book of abstracts; June 10-14, 2019; Herceg Novi, Montenegr

Fenotyp typu „talia hipertriglicerydemiczna“ i zespół metaboliczny określany na podstawie różnych kryteriów oraz zależności między tymi zaburzeniami a kontrolą stężeń lipidów i glikemii u chorych na cukrzycę typu 2

Background: Metabolic syndrome (MetS) describes clustering of obesity, dyslipidemia, hyperglycemia and hypertension and increases risk for cardiovascular disease and type 2 diabetes. The ‘hypertriglyceridemic waist’ phenotype (HTGW) represents a simple approach to identifying individuals with increased risk. The aim of the study was to determine the prevalence of HTGW and MetS in type 2 diabetic patients, and to examine their relation to lipids and blood glucose control. Material and methods: 300 type 2 diabetic patients were analysed, and their history of diabetes, anthropometric measures, measurements of blood pressure (BP), lipids and glycemic control parameters were taken. Results: In type 2 diabetic patients, the prevalence of MetS was 71.0% by the AHA/NHLBI definition and 75.33% by the IDF definition. The prevalence was 62.58% and 66.45% in men, and 80% and 84.83% in women by the same definitions, respectively. There were 41.33% of patients with HTGW (42.76% among women and 40% among men). There were statistically significant differences of age, fasting plasma glucose (FPG) and postprandial glucose (PPG) in women with and without MetS according to both definitions, and of total and LDL cholesterol with and without MetS according to AHA/NHLBI (but not IDF). In men, there were statistically significant differences of total cholesterol and of HbA1c with and without MetS according to AHA/NHLBI (but not IDF). Women with HTGW had higher levels of total and LDL cholesterol, systolic and diastolic BP. Men with HTGW had higher levels of total cholesterol, diastolic BP, HbA1c, FPG and PPG. Conclusions: Determining MetS or HTGW helps identify those with increased cardiovascular risk. (Pol J Endocrinol 2011; 62 (4): 316–323)Wstęp: Zespół metaboliczny (MetS) obejmujący otyłość, dyslipidemię, hiperglikemię i nadciśnienie tętnicze zwiększa ryzyko chorób sercowo-naczyniowych i cukrzycy typu 2. Określanie fenotypu „talii hipertriglicemicznej” (HTGW) jest prostą metodą identyfikowania chorych z grupy wysokiego ryzyka. Celem badania było ustalenie częstości HTGW i MetS u chorych na cukrzycę typu 2 oraz ocena zależności miedzy tymi zaburzeniami a kontrolą stężeń lipidów i glikemii. Materiał i metody: Do badania włączono 300 chorych na cukrzycę typu 2 i przeanalizowano dane dotyczące przebiegu cukrzycy, parametrów antropometrycznych, wartości ciśnienia tętniczego, stężeń lipidów i kontroli glikemii. Wyniki: U chorych na cukrzycę typu 2 kryteria MetS według definicji AHA/NHLBI spełniało71,0%, a kryteria IDF — 75,33%; odsetek chorych z MetS wynosił wśród mężczyzn odpowiednio 62,58% i 66,45%, a wśród kobiet 80% i 84,83%. U 41,33% chorych stwierdzono cechy HTGW, 42,76% tej grupy stanowiły kobiety, a 40% mężczyźni. U kobiet wykazano istotne statystycznie różnice w zakresie wieku, glikemii na czczo (FPG) i glikemii poposiłkowej (PPG) między grupami z MetS i bez niego, rozpoznanym na podstawie obu definicji, natomiast w zakresie stężenia cholesterolu całkowitego i frakcji LDL różniły się one tylko między grupami z MetS i bez niego wydzielonymi na podstawie definicji AHA/NHLBI (a nie na podstawie kryteriów IDF). U mężczyzn wykazano statystycznie istotne różnice stężeń cholesterolu całkowitego HbA1c między grupami z MetS i bez niego określonym według AHA/NHLBI (ale nie według IDF). U kobiet z HTGW stwierdzono wyższe stężenia cholesterolu całkowitego i cholesterolu frakcji LDL oraz wyższe wartości ciśnienia skurczowego i rozkurczowego. U mężczyzn z HTGW odnotowano wyższe wartości stężeń cholesterolu całkowitego, rozkurczowego ciśnienia tętniczego, HbA1c, FPG i PPG. Wnioski: Rozpoznanie MetS lub HTGW pozwala zidentyfikować osoby obciążone zwiększonym ryzykiem sercowo-naczyniowym. (Endokrynol Pol 2011; 62 (4): 316–323