Millimeter-Wave Transmitter with LTCC Antenna and Silicon Lens

Millimeter-wave (mm-wave) transmitters are often fabricated using advanced technology and require a sophisticated manufacturing facility. Access to such technologies is often very limited and difficult to gain particularly at the initial stage of research. Therefore, to increase the accessibility of mm-wave transmitters, this study proposes a design that can be assembled in a standard microwave laboratory from commercially available or externally ordered components. The transmitter demonstrated in this paper operates above 100 GHz and is based on a low-temperature co-fired ceramic board in which the antenna array, microstrip lines, and power-supply lines are fabricated in a single process. Different technologies are used to assemble the module, e.g., wire-bonding, soldering, and wax adhesion. Advantages and disadvantages of the proposed design are given based on experimental evaluation of the prototype. Although the performance of the developed transmitter is not as good as that of the similar modules available in the recent literature, the results confirm the feasibility of a mm-wave transmitter that is assembled without employing advanced technologies and superior machinery

Hepatitis E in general practice

W ostatnich latach obserwuje się coraz większy wzrost liczby zachorowań na WZW E. Chorobę wirusową wywoływaną przez wirus RNA – HEV (Hepatitis E Virus). Do zakażenia dochodzi głównie drogą pokarmową przez skażoną żywność (wieprzowina, dziczyzna, niemyte warzywa, owoce, owoce morza) lub wodę. Rezerwuarem wirusa są głównie świnie i dziki, ale także koty, kury i człowiek. Opisano przypadki transmisji HEV w związku z przetoczeniem krwi i preparatów krwiopochodnych oraz transplantacją narządów. Do tej pory największą liczbę zachorowań obserwowało się w Indiach, Azji południowo-wschodnej i Afryce, ale coraz więcej zachorowań obserwuje się również w Europie, w tym Polsce. Najczęściej chorują młodzi dorośli i osoby w średnim wieku. Okres wylęgania choroby, czyli czas od zakażenia do pojawienia się objawów, wynosi około 40 dni (od 2 tygodni do 8 tygodni). Przebieg kliniczny jest podobny do przebiegu wirusowego zapalenia wątroby typu A. Właściwe rozpoznanie choroby, monitorowanie i odpowiednie leczenie pozwala uniknąć wielu powikłań.  In recent years, there has been an increase in the incidence of viral infections of hepatitis E, a viral disease caused by RNA virus — hepatitis E virus (HEV). The infection is mainly through food by contaminated food (pork, game, uncooked vegetables, fruits, seafood) or even water. The reservoir of the virus are mainly pigs and wild boars, but also cats, hens and humans. There have been reported cases of HEV transmission in relation to blood transfusion and blood-derived preparation or organ transplantation. So far, the highest number of cases has been seen in India, South-East Asia and Africa, but more and more are being seen in Europe, including Poland. Young adults as well as middle-aged people are most commonly affected. The incubation period, the time from infection to symptom onset, is about 40 days (2–8 weeks). The clinical course is similar to that of hepatitis A. Proper diagnosis, monitoring and adequate treatment of the disease will avoid many complications

Proportioning accuracy of foam concentrate testing in periodic control of foam fixed extinguishing systems

The proper concentration of foam concentrate in water solution is a key factor in the effectiveness of fire-fighting foams produced using all currently used foam systems. The standard method for measuring the concentration of foaming agent, used to control the operation of the foam systems, is conductivity method. In this study, the applicability of the refractive index of the solution and the conductivity method was tested. The research found that the conductivity method can be used to determine the actual concentrations of all types of foaming agents in the solutions made from tap water, or water of similar electrical conductivity, of approx. 0.5 ÷ 0.8 mS/cm. Conductivity meter must be equipped with temperature compensation system. Measurement uncertainty is estimated to be ± 0.1 vol. % under optimal conditions for this method. In the case of water with high electrical conductivity, also refractometric method gives good results. In the case of solutions made with tap water and foaming agents working concentrations of 3% and more acceptable uncertainty in the measurements provides portable digital refractometer without temperature stabilization. In other cases, obtaining sufficient accuracy requires sample temperature stabilization during the test

Proportioning accuracy of foam concentrate testing in periodic control of foam fixed extinguishing systems

The proper concentration of foam concentrate in water solution is a key factor in the effectiveness of fire-fighting foams produced using all currently used foam systems. The standard method for measuring the concentration of foaming agent, used to control the operation of the foam systems, is conductivity method. In this study, the applicability of the refractive index of the solution and the conductivity method was tested. The research found that the conductivity method can be used to determine the actual concentrations of all types of foaming agents in the solutions made from tap water, or water of similar electrical conductivity, of approx. 0.5 ÷ 0.8 mS/cm. Conductivity meter must be equipped with temperature compensation system. Measurement uncertainty is estimated to be ± 0.1 vol. % under optimal conditions for this method. In the case of water with high electrical conductivity, also refractometric method gives good results. In the case of solutions made with tap water and foaming agents working concentrations of 3% and more acceptable uncertainty in the measurements provides portable digital refractometer without temperature stabilization. In other cases, obtaining sufficient accuracy requires sample temperature stabilization during the test

Millimeter-Wave Transmitter with LTCC Antenna and Silicon Lens

Millimeter-wave (mm-wave) transmitters are often fabricated using advanced technology and require a sophisticated manufacturing facility. Access to such technologies is often very limited and difficult to gain particularly at the initial stage of research. Therefore, to increase the accessibility of mm-wave transmitters, this study proposes a design that can be assembled in a standard microwave laboratory from commercially available or externally ordered components. The transmitter demonstrated in this paper operates above 100 GHz and is based on a low-temperature co-fired ceramic board in which the antenna array, microstrip lines, and power-supply lines are fabricated in a single process. Different technologies are used to assemble the module, e.g., wire-bonding, soldering, and wax adhesion. Advantages and disadvantages of the proposed design are given based on experimental evaluation of the prototype. Although the performance of the developed transmitter is not as good as that of the similar modules available in the recent literature, the results confirm the feasibility of a mm-wave transmitter that is assembled without employing advanced technologies and superior machinery

Intraday total column ozone measurements at Belsk, Poland, with the Dobson spectrophotometer no.84 since March 23, 1963 up to December 31, 2019

A homogenized long-term dataset comprises results of the total column ozone measurements with the Dobson spectrophotometer no.84 at Belsk (51.835079°N, 20.791437°E) in central Poland. The observations were made manually at intervals depending on weather conditions. The Station is managed by the Institute of Geophysics, Polish Academy of Sciences. The data series contains the results of all intraday Dobson spectrophotometer measurements since the beginning of the ozone observations at Belsk (March, 23, 1963) up to December 31, 2019 together with the corresponding ozone air mass, cloud type over the station, and the observation codes including used UV wavelength pairs and the observation type. The data set allows to study the ozone column variability over wide time scales, from intraday oscillations to decadal trends. This is important because the ozone layer protects the Earth from harmful UV rays. The ground-based data base could also be used to validate satellite observations of the atmospheric ozone