The rise of innovation in the electrical industry is driven by the controlled design of new materials. The hybrid materials based on magnetite/nanocellulose are highly interesting due to their various applications in medicine, ecology, catalysis and electronics. In this study, the structure and morphology of nanocellulose/magnetite hybrid nanomaterials were investigated. The effect of nanocellulose loading on the crystal structure of synthesized composites was investigated by XRD and FTIR methods. The presented study reveals that the interaction between the cellulose and magnetic nanoparticles depends on the nanocellulose content. Further, a transition from cellulose II to cellulose I allomorph is observed. SEM and EDS are employed to determine the variation in morphology with changes in component concentrations. By the calculation of magnetic interactions between adjacent Fe³⁺ and Fe²⁺ ions within composites, it is determined that ferromagnetic coupling predominates.

Development in many areas of engineering and technology are closely linked to the development of new or improvement of existing materials. Having in mind wide use of bacterial nanocellulose (BNC) in various areas of everyday life, from biomedicine, ecology to electronics, BNC-based composites are becoming widely used and attracting the attention of the scientific community. It is especially important to examine in detail the synthesis parameters that affect the changes in the crystal structure and morphology of the obtained composites, having in mind that these changes have a crucial influence on their final functional properties. In this paper, a composite material based on bacterial nanocellulose BNC (as the matrix) and ferromagnetic Fe3O4 was studied. BNC was obtained by the activity of acetic fermentation bacteria after 7 days of growth in a suitable medium. The research is aimed to optimization of the Fe3O4 precipitation conditions. It's especially considering the time interval of BNC films spend in the iron salt solution. The influence of the performed synthesis conditions was considered by the SEMEDS, FTIR and XRD methods.

Ultrasound is becoming increasingly available and incorporated into emergency medicine. Focused echocardiographic evaluation in resuscitation (FEER) is a training program available to emergency doctors in order to ensure adequate application of echocardiography in the cardiac arrest setting. The FEER protocol provides an algorithm, whereby a ?quick view? can be provided in 10 seconds during minimal interruptions in chest compressions. Performing ultrasound in the cardiac arrest setting is challenging for emergency doctors. The International Liaison Committee on Resuscitation recommend the ?quick look? echocardiography view can be obtained during the 10-second pulse check, minimizing the disruption to cardiopulmonary resuscitation.

Introduction/Objective. The purpose of the current Echocardiographic Society of Serbia (ECHOS) survey was to assess echocardiography practice in Serbia during Coronavirus disease 2019 (COVID-19) pandemic. Methods. An online survey consisting of 12 questions about the usage of echocardiography, the availability of portable ultrasound devices and personal protective equipment (PPE) was sent to all ECHOS members. Results. Overall, 126 ECHOS members (43%) answered the survey. One-third of respondents (36%) were physicians from specialized COVID-19 centers. During the pandemic, indications for echocardiographic examination were restricted in both COVID-19 and non-COVID-19 centers. In COVID-19 centers, 41% of respondents performed lung ultrasound (LUS) to each patient versus 26% in non-COVID-19 centers. Transesophageal echocardiography (ТЕЕ) was not performed in suspected or confirmed COVID-19 cases in any center. Portable ultrasound devices were available to 66% of respondents from COVID-19 versus 44% of respondents from non-COVID-19 centers (p=0.018). The respondents reported a regular use of PPE, regardless of the patient's COVID-19 status and found their personal knowledge about protective measures and use of PPE satisfactory. Conclusion. During the COVID-19 pandemic in Serbia, indications for echocardiography were restricted to clinical scenarios in which the results of examination were expected to alter the patient management. In both COVID-19 and non-COVID-19 centers, the use of PPE was in line with national and international recommendations. A wider availability of portable ultrasound devices and application of LUS could improve patient management in similar situations in the future.

Ispitivanje intenziteta el. polјa u frekvencijskom opsegu od 27MHz do 6GHz je važno radi procene nivoa izloženosti ljudi elektromagnetnom(EM) zračenju, koje može da utiče na zdravlјe. Ispitivanja su izvršena u zoni gde je potencijalna izloženost nivoima EM polјa najveća. Ispitivane su karakteristične pozicije: viši spratovi i mesta gde je povećana frekventnost lјudi ali i neposredan dvorišni i okolni prostor do najbližeg autobuskog stajališta. Ispitivanje je izvršeno u skladu sa rasporedom postavlјene opreme predmetnog izvora ispitivanja, potencijalnih relevantnih izvora i potencijalnih uzroka perturbacije prema standardnoj akreditovanoj metodologiji ispitivanja EM polјa radio telekomunikacione opreme i sistema. Merna sonda postavlјena je u planiranoj geometriji u datom prostoru na distanci od 1,7m. Tokom merenja, osobe koje čine merni tim, udalјene su od merne sonde bar na distanci od 1,5m. Ovaj pristup osigurava pouzdanost i tačnost merenja bez nepotrebnih rizika po zdravlјe. Na predmetnoj lokaciji instalirana je četvorosektorska bazna stanica koja podržava mobilne tehnologije: GSM 900, LTE 800, LTE 1800 i LTE 2100. Na osnovu izvršenih merenja i proračuna se pokazalo da su intenziteti električnog polјa za LTE 800, LTE 1800 i UMTS sisteme manji od 15,5V/m, 23,4V/m i 24,4V/m, što su referentni granični nivoi za ove sisteme. Vrednosti faktora izloženosti u razmatranom slučaju manje su od 1 u svim zonama, što ukazuje na nizak nivo izloženosti u odnosu na dozvolјene granice.

Waste biomass (WB) represents renewable resource that can be used in solving complex energy/environment demands. Possible route of WB revalorization is its thermochemical conversion into the biochar, which has remarkable potential as sustainable tool in biomass waste disposal issue, climate change mitigation, and soil environment protection. In this paper, four types of biochar were obtained by WB pyrolysis with intention to be applied as soil amendments. For that purpose, biochar samples were characterized according to Test Category A: Basic Utility Properties requirements according to the International Biochar Initiative (IBI). Analyses included basic properties required to assess the utility of biochar material for use in soil, such as physical properties of particle size and moisture, as well as the chemical properties of elemental proportions obtained from elemental organic analysis (EOA), ash proportion, electrical conductivity, pH and liming ability. Carbon stability was calculated from molar ratios of both H/C and O/C, as well as from proximate analysis results. EOA results shown that all investigated biochars have high content of carbon, ranging from 62.5 to 68.4, classifying them in Class 1 materials. Values of pH ranged between 7.68 and 8.99 indicating alkaline nature of biochars with potential for remediating acidic soils. Calculated H/C ratio was around 0.04 for all samples, while the O/C ranged between 0.40 and 0.54, indicating that biochars pose stable structure and high carbon sequestering potential. Electrical conductivity values showed benefits of biochars incorporation into the soil and valuable agronomic implications, offering beneficial soluble salts content.