Search

Polycyclic aromatic hydrocarbons cause significant environmental and health concerns, necessitating effective remediation strategies. Specifically, biological treatments are only effective for PAH compounds with lower molecular weights, while for the efficient elimination of more complex PAH structures, the photocatalytic method is more recommended. Photocatalytic degradation has primarily relied on TiO2-based materials. However, this review focuses on the utilization of various metal oxide nanomaterials for the degradation or total removal of naphtalene from the environment, especially from wastewater. Precisely speaking, the photocatalytic activity of various nanomaterials is discussed, with an emphasis on photocatalytic degradation mechanisms and the identification of degradation intermediates. Key findings reveal that these materials hold substantial promise, and that photogenerated holes, superoxide radicals, and hydroxyl radicals play crucial roles in the degradation processes highlighting additionally the unique mechanisms of these processes. Important information about the intermediates and pathways of naphtalene degradation discussed in the mechanisms of degradation has been confirmed using gas chromatography-mass spectrometry (GC-MS).

This study explores market efficiency and behavior by integrating key theories such as the Efficient Market Hypothesis (EMH), Adaptive Market Hypothesis (AMH), Informational Efficiency and Random Walk theory. Using LSTM enhanced by optimizers like Stochastic Gradient Descent (SGD), Adam, AdaGrad, and RMSprop, we analyze market inefficiencies in the Standard and Poor’s (SPX) index over a 22-year period. Our results reveal “pockets in time” that challenge EMH predictions, particularly with the AdaGrad optimizer at a size of the hidden layer (HS) of 64. Beyond forecasting, we apply the Dominguez–Lobato (DL) and General Spectral (GS) tests as part of the Martingale Difference Hypothesis to assess statistical inefficiencies and deviations from the Random Walk model. By emphasizing “informational efficiency”, we examine how quickly new information is reflected in stock prices. We argue that market inefficiencies are transient phenomena influenced by structural shifts and information flow, challenging the notion that forecasting alone can refute EMH. Additionally, we compare LSTM with ARIMA with Exponential Smoothing, and LightGBM to highlight the strengths and limitations of these models in financial forecasting. The LSTM model excels at capturing temporal dependencies, while LightGBM demonstrates its effectiveness in detecting non-linear relationships. Our comprehensive approach offers a nuanced understanding of market dynamics and inefficiencies.

Extragonadal germ cell tumors originating in the prostate are extremely rare. Thus far, less than 20 cases were described in the literature. To our knowledge, there are no published cases of primary embryonal carcinoma of the prostate. The present study presents a case of a 24-year-old male with primary prostate embryonal carcinoma. The patient received cisplatin-based chemotherapy. The patient refused a surgical treatment, which resulted in relapse of the disease and death in a short follow-up period. The present case shows that primary embryonal carcinoma may also be found in prostate and indicates the potential importance of timely surgical resection.

This paper describes the frequency analysis of absolute maximum air temperatures, using annual maximum series (AMS) in the period 1961–2010 from 40 climatological stations in Serbia with maximum likelihood estimation of distribution parameters. For the goodness of fit testing of General Extreme Value (GEV), Normal, Log-Normal, Pearson 3 (three parameters), and Log-Pearson 3 distribution, three different tests were used (Kolmogorov-Smirnov, Anderson-Darling, chi-square). Based on the results of these tests (best average rank of certain distribution), the appropriate distribution is selected. GEV distribution proved to be the most appropriate one in most cases. The probability of exceedance of absolute maximum air temperatures on 1%, 0.5%, 0.2%, and 0.1% levels are calculated. A spatial analysis of the observed and modeled values of absolute maximum air temperatures in Serbia is given. The absolute maximum air temperature of 44.9 °C was recorded at Smederevska Palanka station, and the lowest value of maximum air temperature 35.8 °C was recorded at Zlatibor station, one of the stations with the highest altitude. The modeled absolute maximum air temperatures are the highest at Zaječar station with 44.5 °C, 45.6 °C, 47.0 °C, and 48.0 °C and the lowest values are calculated for Sjenica station with 35.5 °C, 35.8 °C, 36.1 °C, and 36.2 °C for the return periods of 100, 200, 500, and 1000 years, respectively. Our findings indicate the possible occurrence of much higher absolute maximum air temperatures in the future than the ones recorded on almost all of the analyzed stations.

The end of the First World War brought changes in international relations and new socio-economic and social challenges. A specific segment was the organization of scientific work. Geographical science and the related disciplines were also looking for their place. A significant qualitative change to the research was brought by the gatherings of the Slavic geographers and ethnographers. At the initiative of Jovan Cvijić, the First Congress was organized in Prague in 1924. In the interwar period, three more congresses were held—in Poland (1927), in the Kingdom of Yugoslavia (1930), and in the Kingdom of Bulgaria (1936). The aim of this paper is an overview of the subjects and outcomes of those events in the social circumstances of that time. The work of the Congresses was divided into several thematic areas, with the dominance of physical geographic, cartographic, and ethnographic research. The importance of the congresses is proven by the fact that the governance structures wholeheartedly supported them. Even though they had a strong impact, the Congresses of the Slavic Geographers and Ethnographers did not provide answers to numerous questions that “troubled” the post-war societies in the second half of the 1920s and 1930s. The results undoubtedly pointed to the symbolic representation of anthropogeographic, demographic, geo(political), and socio-economic subjects. The data on the demographic losses in the Great War were omitted. There were no projections of future trends in the Slavic countries, especially in the context of the new conflict and its consequences.

The paper presents and discusses the landslide research procedure related to the topography before and after its occurrence, using the comparative analysis of two medium-resolution digital terrain models. The case study is the Jovac mega-landslide—the largest landslide to occur in Serbia in the last 100 years, active for three days in February 1977. The indicators used to determine the volume and movement mechanism were the spatial distribution of elevation differences within the two digital terrain models (DTM), and the analysis of geomorphological features before the landslide. The obtained elevation differences allowed the definition of the approximate landslide volume: 11.6 × 106 m3. All the data obtained indicate that the movement mechanism falls into the category of earthflow.

As one of the first European cases of the introduction of COVID-19 certificates, the Serbian Government initiated the measure of limited working hours of restaurants for unvaccinated visitors. Due to such actions and frequent bans on working during the pandemic, many restaurants in Serbia had to lay off workers or close. At the end of October 2021, the certificate for entering restaurants and all catering facilities for all the visitors became mandatory. It is interesting to note that earlier findings suggested that some personality characteristics determine the specific behaviors during the pandemic, but there is still a small number of results related to restaurants’ visitors. This study aimed to investigate the predictive strength of the Big Five Factors (BFF) to attitudes toward visits to restaurants in Serbia during the pandemic, depending on the attitudes toward accepting COVID-19 certificates. A survey was conducted on a total sample of 953 visitors of restaurants in three major cities in Serbia. The results of hierarchical regression analysis showed that Openness and Extraversion positively predict attitudes toward visits to facilities during a pandemic, while Conscientiousness and Neuroticism were negative predictors. However, in the second step of hierarchical regression analysis, attitudes toward a COVID-19 certificate as a mediator variable significantly reduced the negative effect of Neuroticism on the attitudes toward visits. It seems that, by obtaining the certificate, the fear of unsafe stays in restaurants can be reduced, and that making decisions about (no) visiting restaurants during the pandemic does not necessarily have to be compromised by emotional lability.

Recent research shows reductions in the VLF signal noise amplitude that begin before particular earthquakes whose epicentres are more than 100 km away from the signal propagation path. In this paper, we extend this research to studying the noise amplitude during periods of intense seismic activity in a localized area. We analyse variations in the VLF signal noise amplitude over a period of 10 days (25 October–3 November 2016) when 981 earthquakes with the minimum magnitude of 2 occurred in Central Italy. Out of these events, 31 had the magnitude equal or greater than 4, while the strongest one had the magnitude of 6.5. We observe the VLF signal emitted by the ICV transmitter located in Sardinia (Italy) and recorded in Belgrade (Serbia). Bearing in mind that the trajectory of this signal crosses the area in which the observed earthquakes occurred, we extend the existing research to study of variations in the noise amplitude of the signal propagating at short distances from the epicentres of the considered earthquakes. In addition, we analyse the impact of a large number earthquakes on characteristics of the noise amplitude and its reductions before particular events. In order to examine the localization of the recorded changes, we additionally analysed the noise amplitude of two reference signals emitted in Germany and Norway. The obtained results show the existence of the noise amplitude reduction preceding individual strong or relatively strong earthquakes, and earthquakes followed by others that occurred in a shorter time interval. However, the additional noise amplitude reductions are either not pronounced or they do not exist before the considered events in periods of the reduced noise amplitude remain from previous earthquakes. Reductions in noise amplitudes for all observed signals indicate a larger perturbed area through which they spread or its closer location to the receiver. The analysis of daily values of parameters describing the noise amplitude reveals their variations start up to 2 weeks before the seismically active period occurs.

The Yugoslav participation in the Jewish emigration to Mandatory Palestine and, after 1948, to Israel, can be defined as a process consisting of six stages. When the migration is observed on the level of socio-political circumstances, the discontinuity between these stages is apparent. However, the same discontinuity is not to be found when the process is deconstructed down to and examined on the level of families and individuals involved in it. The aspiration of individuals to join members of their families already in Palestine, especially after the tragic losses suffered in the Holocaust, has persevered as one of the key motives driving emigration from Yugoslavia. This paper examines the way in which family ties continuously drove emigration to Mandatory Palestine/Israel and pulled its individual stages into an integral whole. It is primarily based on documents kept at the Archives of the Jewish Historical Museum in Belgrade.

Extraction of information in the form of oscillations from noisy data of natural phenomena such as sounds, earthquakes, ionospheric and brain activity, and various emissions from cosmic objects is extremely difficult. As a method for finding periodicity in such challenging data sets, the 2D Hybrid approach, which employs wavelets, is presented. Our technique produces a wavelet transform correlation intensity contour map for two (or one) time series on a period plane defined by two independent period axes. Notably, by spreading peaks across the second dimension, our method improves the apparent resolution of detected oscillations in the period plane and identifies the direction of signal changes using correlation coefficients. We demonstrate the performance of the 2D Hybrid technique on a very low frequency (VLF) signal emitted in Italy and recorded in Serbia in time vicinity of the occurrence of an earthquake on 3 November 2010, near Kraljevo, Serbia. We identified a distinct signal in the range of 120–130 s that appears only in association with the considered earthquake. Other wavelets, such as Superlets, which may detect fast transient oscillations, will be employed in future analysis.

In the process of taking necessary preparations for mass Jewish emigration to Israel, during which almost 8,000 people left Yugoslavia, executives of the Federation of Jewish religious communities of Yugoslavia decided on defining a specific structure within the community to deal with two basic tasks – communicating information relevant to the migration to all of the participating sides and dealing with problems potentially arising from the process. This was to be achieved through a network of Emigration Commissions. The Central Emigration Commission, established in Belgrade and consisting of Federation Executive Board Members, was in charge of coordinating the migration process on a grand scale. Regional Emigration Commissions were formed with larger Jewish communities, each of them responsible for organizing the migration in a number of communities under their jurisdiction. Finally, local Emigration Commissions were founded with each community taking part in the migration. In theory, the interaction of these Commissions was limited by a very strict hierarchy. While top to bottom communication honoured the proposed model for the most part, passing information in the opposite direction proved to be much more of a challenge. Traditional dynamics within the Jewish community proved a much more significant influence than the proposed internal hierarchy. It was due to this what interpersonal relations ended up playing a far more significant role than did the network of Emigration Commissions. This paper examines how the organized emigration process was influenced by the proposed hierarchy, how the proposed distribution of different duties amongst the various levels of Emigration Commissions functioned when applied to real problems and what led to this internal framework finally failing. Relevant documents, used in writing this paper are held at the Archives of the Jewish Historical Museum in Belgrade.

The aim of this study is to quantify the intensity of the urban heat island in Belgrade through the seasons. Air temperature observations from 23 meteorological stations in Serbia in the period 1949–2008 were analyzed. Using cluster analysis, we identify the group of stations which the data from the meteorological station Belgrade are the most similar to. It has been shown that, through all the seasons, air temperatures in Belgrade are significantly higher than the average in the wider surroundings. The greatest difference is in winter (1.4 °C), and the smallest is in summer, when it is 0.9 °C. It is greater in fall (1.2 °C) than during spring months, when it is 1.0 °C. Although the contribution of air temperatures in Belgrade to the increase of the average value of air temperature in its cluster is statistically significant, it is without any practical significance.

Solar ultraviolet (UV) radiation is a significant health hazard in the warm part of the year. In order to assess the level of hazard and the effects of UV radiation on the living world, long-term measured or estimated data are needed. In Novi Sad, the measurement of UV radiation has been performed since 2003, while ozone measurements have been made since 2007. However, those data sets are too short for assessing long-term biological effects. Therefore, several techniques for reconstruction of UV radiation doses have been developed. Reconstruction techniques are based on using available ground-based measurements of the meteorological data and satellite measurements of the total ozone column. It is shown that techniques that use ozone data show better performance than those that use only ground-based meteorological measurements. However, the difference between the performances of the methods is smaller when it comes to the monthly values, indicating that the techniques which use only ground-based meteorological measurements are roughly as good as the ozone-based techniques for assessing long-term changes in the surface UV radiation. The statistically significant increasing long term-trend of annual mean erythemal UV doses (ERY) and the decreasing trend in the total ozone column in Novi Sad since 1981 have been noticed. An increase in ERY has been noticed in all the seasons except in autumn and it is the highest in winter. The analysis showed that the increase in the ERY in the period 1981–1996 was mainly caused by the total ozone column, while the increase after 1996 is largely caused by cloudiness.

Regardless of their type and structure, natural resources represent the basis for industrial and economic development of every country. The aim of this study is to determine and display the natural potential in the territory of the City of Subotica (Vojvodina Province in Northern Serbia), on the basis of four protected natural areas. These areas are: Palić Nature Park, Ludaško jezero Special Nature Reserve, Selevenjske pustare Special Nature Reserve and Subotička peščara Protected Landscape of Exceptional Distinction. All listed areas represent the main aspects for ecotourism development in this part of the country, so one of the aims of the research is to identify key stakeholders that should be involved in proper developing of this form of tourism. When preforming this study, survey research techniques were used. Respondents were Subotica’s residents, who were asked to rate the state of the environment in these surroundings, as well as to give their opinions about the possibilities for the development of ecotourism. Based on the analysis of the dependent and independent variables, it was concluded that the residents are generally satisfied with the conditions of the environment, they also consider that the development of this form of tourism would raise the awareness of locals about the importance of preserving these protected areas. The result may be significant when launching a new tourism product, while preserving the protected areas and adapting for future visitors’ needs.

Understanding the movement of tourists within a destination and predicting future movements have their practical applications for destination management, product development, marketing and attraction. We analyzed the seasonality of tourist presence in Belgrade, using the ARIMA models, with the aim of predicting future movement. We came to the result that about three-fourths of tourists in this area consist of domestic tourists or residents of Belgrade and people from other parts of Serbia, while the rest are foreign tourists. By increasing the number of foreign tourists there would be a significant economic development both for Ada Ciganlija Island and for Belgrade. This also points to the need for improving marketing and significantly engaging and making this area closer to foreign tourists.

The effect of potassium sorbate as well as 5-chloro-1H-benzotriazole - potassium sorbate on the corrosion behavior of copper in acidic sulfate media containing Cl- ions was examined. For this purpose, the electrochemical methods and quantum chemical calculations were used. The inhibition efficiency in the presence of 5-chloro-1H-benzotriazole - potassium sorbate was higher than in the presence of potassium sorbate. Also, the inhibition efficiency of binary inhibitor depends on the concentration of Cl- ions added in sulfate solution. According to the results obtained by potentiodynamic polarization measurements, both potassium sorbate and 5-chloro-1H-benzotriazole - potassium sorbate behave as mixed type inhibitors. Quantum chemical parameters are in good agreement with results obtained by electrochemical measurements.

The analysis of the bioclimatic conditions is becoming increasingly relevant in climate interpretations for human needs, particularly in spatial planning, tourism, public health, sports events, bio-prognosis, etc. In this context, our study presents general temporal bioclimatic conditions in Belgrade, defined based on the PET, mPET and UTCI heat budget indices. Monthly, seasonal and annual indices were analyzed for urban and suburban weather stations based on 43 annual sets of meteorological data obtained by hourly observations at 7 h and 14 h CET. This study aims to present the distribution of PET, mPET and UTCI indices to show the pattern of each index in a mild climate location and to examine annual and seasonal differences of each index in the Belgrade urban center and suburban part of the city. The study results indicate higher biothermal stress in the urban area compared to the suburban zone and that the indices are congruent during the summer. At the same time, during the winter, they are more difficult to compare due to their peculiarities becoming more noticeable. The results obtained of all mean monthly and mean annual values of all three indices clearly indicate the difference that follows the definition of the urban heat island (UHI), particularly those from morning observation and winter season. The UTCI index shows the most significant monthly, seasonal and annual difference between urban and suburban areas for both observations. The annual difference of ΔUTCI7h amounts to 1.5 °C is the same as the annual difference of minimum temperatures (Δtmin). In contrast, the annual differences of ΔPET7h ΔmPET7h are °smaller (0.8 °C and 0.7 °C) and closer to the annual differences of maximum temperatures Δtmax amounted of 0.6 °C.

In this work, we study the impact of high-energy radiation induced by solar X-ray flares on the determination of the temporal change in precipitable water vapor (ΔPWV) as estimated using the synthetic aperture radar (SAR) meteorology technique. As recent research shows, this radiation can significantly affect the ionospheric D-region and induces errors in the estimation of the total electron content (TEC) by the applied models. Consequently, these errors are reflected in the determination of the phase delay and in many different types of measurements and models, including calculations of meteorological parameters based on SAR observations. The goal of this study is to quantify the impact of solar X-ray flares on the estimation of ΔPWV and provide an estimate of errors induced if the vertical total electron content (VTEC) is obtained by single layer models (SLM) or multiple layer models (MLM) (these models do not include ionosphere properties below the altitude of 90 km as input parameters and cannot provide information about local disturbances in the D-region). The performed analysis is based on a known procedure for the determination of the D-region electron density (and, consequently, the vertical total electron content in the D-region (VTECD)) using ionospheric observations by very low frequency (VLF) radio waves. The main result indicates that if the D-region, perturbed by medium-sized and intense X-ray flares, is not modeled, errors occur in the determination of ΔPWV. This study emphasizes the need for improved MLMs for the estimation of the TEC, including observational data at D-region altitudes during medium-sized and intense X-ray flare events.

This paper deals with speciϐic aspects of the emigration of Jewish children from post-war Yugoslavia to Palestine and, after 1948, to the newly established state of Israel. The attention is primarily focused on the minors who were left without parental care during the war. Based on the personal histories of three emigrants, one who tried to leave Yugoslavia immediately after the end of the war and two who applied for organized emigration, this paper studies the general framework of the two separate phases of the migration process and their interdependence. General solutions were modiϐied to meet individual needs of emigrants. The paper is written on the basis of the material of the Archive of the Jewish Historical Museum in Belgrade.

National parks as the most complex category of protected resources are provided for the overall sustainable development, and coordination of geography, tourism and nature conservation is a basic development orientation of these areas in the future. In order to analyze the state of environment, but also the impact of tourism on nature, the method of indicators of sustainable development of tourism of the World Tourism Organization (UNWTO) is applied in the paper in the case of the National Park Tara (Western Serbia). The study included analysis and evaluation of indicators related to the ecological value of the area and direct impact of tourism activity on the protection of nature.

To estimate influence of 2-mercapto-1-methylimidazole and 4(5)methil-imidazole on electrochemical behaviour of copper electrode in 0.5 moldm-3 Na2SO4 solution, pH 3, following methods were used: open circuit potential measurements, potentiodynamic polarization, chronoamperometry. Potentiodynamic measurements showed that investigated inhibitors can be used as copper corrosion inhibitor in acidic 0.5 moldm-3Na2SO4 solution. Increase of concentrations leads to better inhibitor efficiency. These results were confirmed using the chronoamperometry. Adsorption of 2-mercapto-1-methylimidazole and 4(5)methil-imidazole obeys Langmuir adsorption isotherm.

In this paper we analyse temporal variations of the phase of a very low frequency (VLF) signal, used for the lower ionosphere monitoring, in periods around four earthquakes (EQs) with magnitude greater than 4. We provide two analyses in time and frequency domains. First, we analyse time evolution of the phase noise. And second, we examine variations of the frequency spectrum using Fast Fourier Transform (FFT) in order to detect hydrodynamic wave excitations and attenuations. This study follows a previous investigation which indicated the noise amplitude reduction, and excitations and attenuations of the hydrodynamic waves less than one hour before the considered EQ events as a new potential ionospheric precursors of earthquakes. We analyse the phase of the ICV VLF transmitter signal emitted in Italy recorded in Serbia in time periods around four earthquakes occurred on 3, 4 and 9 November 2010 which are the most intensive earthquakes analysed in the previous study. The obtained results indicate very similar changes in the noise of phase and amplitude, and show an agreement in recorded acoustic wave excitations. However, properties in the obtained wave attenuation characteristics are different for these two signal parameters.

Atmospheric properties have a significant influence on electromagnetic (EM) waves, including the propagation of EM signals used for remote sensing. For this reason, changes in the received amplitudes and phases of these signals can be used for the detection of the atmospheric disturbances and, consequently, for their investigation. Some of the most important sources of the temporal and space variations in the atmospheric parameters come from the outer space. Although the solar radiation dominates in these processes, radiation coming out of the solar system also can induces enough intensive disturbance in the atmosphere to provide deflections in the EM signal propagation paths. The aim of this issue is to present the latest research linking events and processes in outer space with changes in the propagation of the satellite and ground-based signals used in remote sensing.

The ionospheric D-region affects propagation of electromagnetic waves including ground-based signals and satellite signals during its intensive disturbances. Consequently, the modeling of electromagnetic propagation in the D-region is important in many technological domains. One of sources of uncertainty in the modeling of the disturbed D-region is the poor knowledge of its parameters in the quiet state at the considered location and time period. We present the Quiet Ionospheric D-Region (QIonDR) model based on data collected in the ionospheric D-region remote sensing by very low/low frequency (VLF/LF) signals and the Long-Wave Propagation Capability (LWPC) numerical model. The QIonDR model provides both Wait’s parameters and the electron density in the D-region area of interest at a given daytime interval. The proposed model consists of two steps. In the first step, Wait’s parameters are modeled during the quiet midday periods as a function of the daily sunspot number, related to the long-term variations during solar cycle, and the seasonal parameter, providing the seasonal variations. In the second step, the output of the first step is used to model Wait’s parameters during the whole daytime. The proposed model is applied to VLF data acquired in Serbia and related to the DHO and ICV signals emitted in Germany and Italy, respectively. As a result, the proposed methodology provides a numerical tool to model the daytime Wait’s parameters over the middle and low latitudes and an analytical expression valid over a part of Europe for midday parameters.

This paper deals with the continuity between the illegal influx of Jewish refugees into the Kingdom of Yugoslavia and the organized emigration of Yugoslav Jews to Israel, which took place between 1948 and 1952. For it to be possible to directly point out the connection between two separate stages of Yugoslav state participation in the migration process, the interwar-period migration to Palestine and the mass migration movement of the post-war period were deconstructed to the level of individuals taking part in it. The case of Ernest and Ilsa Beschinsky was examined, as they are the only refugees whose movement can be traced in relative detail from the moment of arrival in the Kingdom of Yugoslavia, consequent to the “Anschluss”of Austria to the time of applying for the organized emigration to Israel. The paper is based on documents held in the Archives of the Jewish historical museum in Belgrade.

The aim of this paper is to examine the spatial and temporal variability of the average monthly, seasonal and annual air temperatures in Serbia. Therefore, data from 64 climatologic stations were analyzed in the period from 1961 to 2010. Based on the data, on the position of the stations (their latitude, longitude, altitude), and the characteristics of the terrain in their vicinity (inclination and terrain exposure in a radius of 10 km around the station), a regression model was constructed based on which air temperatures are interpolated for the territory of Serbia. The rootmean-square error (RMSE) of the regression model ranged from 0.2 ºC in January, February and November to 1.1 ºC in August. Spatial distribution of air temperatures is shown (maps of mean monthly, mean seasonal and mean annual air temperatures are made), and the Sen's procedure was used to calculate trends of air temperatures (maps of average monthly, mean seasonal and mean annual trends of air temperatures). The Mann-Kendall test was used to test the significance of air temperature trends. Apart from the southeast, the whole territory of Serbia has practically experienced a statistically significant rise in the average annual air temperature, with the highest increase in the summer and winter months.

Forest fires in Portugal (June 17–24, 2017) destroyed 64 lives and caused considerable material damage. The coronal hole CH807 and the energy region S5710 were in the geoeffective position on the Sun immediately before the outbreak of fires. In the period that preceded it, as well as at the time of the fires, increased values of the solar wind (SW) parameters (temperature, speed and density of particles) were recorded. In addition, a geomagnetic disorder was recorded. The shape and size of the burning areas, as well as the low air pressure over Portugal indicate the possibility of the effect of positively charged particles that came from the area south, i.e. southwest of Portugal. Nevertheless, it is a specific case that would have to be investigated in more detail.

The paper presents a concise overview of the theoretical framework on which climate classifications are based. Beside short review of climate classifications, namely climatic regionalization for Serbia (or wider area including Serbia), main deficiency of these research was ascertained (which primarily relate to the period on the basis of which climate regionalization was carried out). The criteria of the Köppen climate classification are presented, on the basis of which the climate regionalization of Serbia has been carried out. The methodology of making maps of air temperatures and precipitation amounts has been described, on the basis of which a map of the climate regions of Serbia has been created. Spatial distribution of the types and subtypes of the climates in Serbia has been briefly described. It has been pointed to the constraints of the climate regionalization that arise from the theoretical bases of the climate classifications, but also from nature of the collected data and the applied methodology.

Concrete is a material that is widely used by mankind. Although different deterioration mechanisms can lead to degradation of the concrete itself, reinforcement corrosion is the biggest durability issue for reinforced concrete structures. One of the key parameters influencing the corrosion rate is pH value. Accordingly, this work presents two capacitive sensor platforms—one based on parallel plate electrodes and the other based on a planar interdigitated electrode structure. The first platform is used to determine whether the pH value is lower or higher than a predetermined limit (around 11) and this device was successfully tested using concrete suspensions. The second platform can determine the pH value by establishing a relationship between pH and measured capacitance from a powdered concrete specimen. Both multi-layered platforms were manufactured by means of a cost-effective xurography technique, which provides technically and mechanically robust structures very quickly.

Planning based on reliable information about the Earth’s surface is an important approach to minimize economic expenses conditioned by natural factors. Data collected by Earth remote sensing (ERS), as well as the analysis of such data using automated classification methods, are becoming more and more important for research and practice activities related to assessing the spatio-temporal structure and sustainability of the Earth’s surface. The analysis of the authenticity of the surrounding areas enables a more objective classification of land plots on the basis of spatial patterns. Combined use of various environmental descriptors enables high-quality handling of neighborhood properties, as each descriptor provides its own specific information about a geospatial system. Experiments have shown that the diagnostics of the emergent properties of such internal structure by analyzing the diversity of dynamic characteristics allows reducing exposure to noise, obtaining a generalized result, and improving the classification accuracy.

This paper describes an innovative design of a wireless, passive LC sensor and its application for monitoring of water content in building materials. The sensor was embedded in test material samples so that the internal water content of the samples could be measured with an antenna by tracking the changes in the sensor’s resonant frequency. Since the dielectric constant of water was much higher compared with that of the test samples, the presence of water in the samples increased the capacitance of the LC circuit, thus decreasing the sensor’s resonant frequency. The sensor is made up of a printed circuit board in one metal layer and water content has been determined for clay brick and autoclaved aerated concrete block, both widely used construction materials. Measurements were conducted at room temperature using a HP-4194A Impedance/Gain-Phase Analyzer instrument.

Silicon-based radio-frequency integrated circuits are becoming more and more competitive in wide-band frequency range. An essential component of these ICs is on-chip (integrated) transformer. It is widely used in mobile communications, microwave integrated circuits, low-noise amplifiers, active mixers, and baluns. This paper deals with the design, simulation, and analysis of novel fractal configurations of the primary and secondary coils of the integrated transformers. Integrated stacked transformers, which use fractal curves (Hilbert, Peano, and von Koch) to form the primary and secondary windings, are presented. In this way, the occupied area on the chip is lower and a number of lithographic processes are decreased. The performances of the proposed integrated transformers are investigated with electromagnetic simulations up to 20 GHz. The influence of the order of fractal curves and the width of conductive lines on the inductance and quality factor is also described.

Extra-skeletal Ewing sarcoma (EWS) occurs in about 12% of EWS patients; at the same time, primary involvement of the kidneys remains extremely rare. Since it was first described in 1975, only a small case series have been reported worldwide. About 95% of surgically treated patients with EWS of the kidney described in the literature underwent nephrectomy, and the remaining patients only had a tumor biopsy. Nephron-sparing surgery (NSS) has not been sufficiently investigated as an alternative in the local surgical treatment of localized disease, mostly as a result of technically unfeasible provisions of negative surgical margins. In this report, we present a unique case of primary EWS of the kidney with an asymptomatic course without radiographic signs that suggest a highly aggressive disease, successfully locally treated with robotic-assisted NSS. This report showcases that robotic-assisted NSS could be a feasible alternative in treatment of localized disease yielding equally good oncological results while, at the same time, creating better prerequisites for necessary adjuvant chemotherapy.