This paper aims at providing a framework suitable for justification of classical convolution integral and Fourier transform in many cases not covered by the usual definition of integral used for signal theory applications. Generalized functions approach from functional analysis is used, simplifying it to be approachable for engineers while retaining the rigor. The generalized functions approach results in an elegant and applicable definition of integral known before in the mathematical literature which is readily applicable in signal theory, justifying formulae usually seen as dubious and criticised for lack of rigor. The study offers a rigorous, simple and understandable definition of integral for use in analog signal theory, helping the formalization of engineering education by means of rigor. Main advantage of this approach is retaining the classical notation used in signal theory as well as its straightforward justification of key formulae in signal theory resulting from convolution and/or Fourier transform.

In this paper we examine the representations of quantum theory and technology in visual media. Namely, we conduct a thorough content analysis of film scripts in science fiction and fantasy to discover ways quantum physics and computing are portrayed: examples include quantum computer scepticism, quantum as proxy for complexity/intelligence, and quantum theory as a vehicle for mysticism. We proceed with motif analysis in quantum theory and technology illustrations in outlets representative of modern global north economy, news, and science writing. There we extract the dominant symbols of quantum discourse and compare them to quantum technology imaginaries in literature. We recognise the repeated and replicated bias towards quantum technology as fuzzy, non­binary, subjective, mystical, as well as a venue of a new arms/space race.

This paper proposes a novel circuit configuration for a high-voltage direct-current circuit breaker (HVDCCB) test bench that differs significantly from conventional test benches. The proposed test bench consists of a modular multilevel cascaded converter (MMCC) that is based on H-bridge cells, an output inductor, and an auxiliary capacitor bank. The proposed test bench is capable of generating controllable output currents up to several kiloamperes and output voltages up to several hundred kilovolts because each MMCC cell is operated by phase-shifted pulse-width-modulated (PSPWM) signals. Consequently, the proposed test bench can simulate a wide range of fault conditions within hardware limitations to test different HVDCCB types with various current and voltage ratings. The flexibility of the proposed test bench is complemented by a longer service lifetime with inherent circuit protection in the case of operational failure of the HVDCCB. The concept of the proposed test bench is verified experimentally on a downscaled test bench that consists of nine H-bridge cells and operates at an equivalent switching frequency of $\mathrm {92.5 kHz }$ .

Background/Aim. For the first time, we evaluated and presented the socio-demographic characteristics, clinical manifestations and laboratory findings of hospitalized coronavirus disease 2019 (COVID-19) patients from Canton Sarajevo, Bosnia and Herzegovina. Methods. This retrospective, single-centre study included 159 RT-PCR verified COVID-19 patients (92 mild/moderate; 67 severe/critical) consecutively hospitalized at the General Hospital "Prim. dr Abdulah Nakaš" in Sarajevo, Bosnia and Herzegovina. Socio-demographic, clinical, and laboratory data on admission were retrospectively obtained from each patient's electronic medical record and patient files by two experienced physicians. Results. 43.4% of the patients belonged to the age range of 46-65 years; 71.1% were men, and 68.6% had comorbidities; hypertension was the most prevalent comorbidity (100%), followed by diabetes (91.7%) and ischemic heart disease (35.8%). The leading clinical symptoms were fever (87.44%), tiredness (77.8%), and body/muscle aches (70.3%). There was significant reduction of blood oxygen saturation (p = 0.005), and significant elevation of D-dimer (p = 0.003), CRP (p = 0.044), and fasting plasma glucose (p = 0.047) in the severe/critical patients group compared to mild/moderate group. Conclusion. Older age, the male gender, confirmed comorbidities, decreased blood oxygen saturation, increased levels of CRP, D-dimer, and fasting plasma glucose, together with symptoms of chest pain/shortness of breath and/or diarrhea occurred more frequently in severe/critical than mild/moderate COVID-19 patients.

The purpose of this study was to explore possible protective effects of vitamin D3 on serum glucose concentration, body weight and histopathology of pancreas and liver. Animals were divided into 3 groups: Control group (n=6), streptozotocin (STZ) group (n=6) and streptozotocin + vitamin D3 (STZ+D3) group (n=6). Rats in the STZ+D3 group starting from the 7th day of experiment were given vitamin D3 for 14 days. Glucose levels and body weight were measured on the 1, 7, 14 and 21st day of experiment. Qualitative histological analysis of pancreas and liver was done using the light microscope with a digital camera. Differences between the groups were tested by one-way analysis of variance (ANOVA) followed by Dunnett's posttest. Differences in repeated measures were tested using paired t-test. On day 14 and 21, blood glucose level in STZ+D3 group was significantly higher compared to the control group of animals but significantly lower than the glucose level registered in STZ group of rats. On day 14 and day 21, body weight in STZ rats was significantly lower compared to weight in STZ+D3 and control groups of rats. Morphological changes, such as shrinkage of islets, vacuolation of both endocrine and exocrine cells, were observed in pancreas of STZ group of animals but were nearly absent in STZ+D3 rats. Similarly, STZ+D3 group of rats showed preserved liver histoarchitecture. Obtained results suggest that vitamin D3 treatment reduces hyperglycemia, exerts beneficial effects on body weight and alleviates histopathological changes in pancreas and liver in STZ-induced diabetic rats.