High particulate matter burden by cigarillos: A laser spectrometric analysis of second-hand smoke of common brands with and without filter

Although the global tobacco market of cigarillos is substantial, little is known about their particulate matter (PM) emissions. For exposure risk assessment of cigarillos, the PM fractions PM10, PM2.5, and PM1 of eight cigarillo brands (four with filters) and a reference cigarette were measured. For this purpose, second-hand smoke was generated by an automatic smoke pump in a measuring chamber with a volume of 2.88 m³. The mean particle concentrations of the cigarillos ranged from 2783 μg/m³ to 6686 μg/m³ for PM10, from 2767 μg/m³ to 6585 μg/m³ for PM2.5, and from 2441 to 4680 μg/m³ for PM1. Mean concentrations of the reference cigarette for PM10, PM2.5, and PM1 were 4400 μg/m³, 4335 μg/m³, and 3289 μg/m³, respectively. Filter-tipped cigarillos showed between 5% and 38% lower PM10 and PM2.5 levels, respectively, and between 4% and 30% lower PM1 levels. Our findings show generally high PM emissions for all investigated tobacco products. Therefore, the declaration of PM amounts to government authorities should be mandatory for all tobacco products. Policymakers should ensure that corresponding information will be provided in the future.

Радиационная стойкость источника субтерагерцового излучения из гетеродина на генераторе на диоде Ганна и умножителя на полупроводниковой сверхрешетке

The radiation resistance to gamma irradiation of various dose levels (0.5 kGy, 2 kGy, 10 kGy) of a subterahertz radiation source from a heterodyne on a Gunn diode and a GaAs / AlAs semiconductor superlattice multiplier was estimated. A measuring chamber for studying the radiation resistance of Gunn diodes has been developed and manufactured. The dependence of the output power on the frequency of a sub-terahertz radiation source before and after irradiation was evaluated analytically.

Improvement of the minimum detectable activity of a free release monitor for small articles

This paper presents results of the development of a small-sized free release monitor designed for the release of materials, various hand tools, equipment and instruments of nuclear enterprises and laboratories staff that weight up to 50 kg, from radiation control. To increase the registration sensitivity of controlled radionuclides, 12 scintillation units based on a 3"x3" sized NaI (Tl) crystal were used as gamma-radiation detector. Volume of the measuring chamber of the monitor amounted to 200 liters, the thickness of the low-background shielding was chosen 50 mm. The values of the minimum detectable activity of the designed monitor for the point sources 123I, 131I, 99mTc, 18F were better than 100 Bq with measurement time not exceeding 60 s.

Developing A Method for Estimation of Tightness Based on Calibration Characteristics

This article discusses methods of assessing tightness of mass-produced products. In order to reduce errors in the calibration of gas analytical leak detectors, a method is proposed which is based on transferring a certain number of molecules from the measuring chamber. This is done by means of a throttle device called frequency resistance. Based on the tests performed, results of the study are displayed.

Improved system for identifying biological tissue temperature using electrical impedance tomography

This paper proposes a cheap and compact medical system that determines the temperature of an object using broadband impedance tomography. This system can be used in medicine to visualize ice structure in tissue during cryosurgical operations, as well as for fault diagnosis and location in studied industrial objects. These effects are achieved by measuring electrical impedance between electrode pairs in the measuring chamber. The assembled prototype is compact, consumes little power, and allows to non-invasively determine the impedance of a target object in real time. The research included experimental studies to determine the dependence of the impedance spectrum of saline water and muscle tissue on temperature in broad band spectrum, which allowed to obtain the dependence of total electrical impedance of target objects on temperature.

The impact of chamber transparency on estimation of peatland net ecosystem exchange

The purpose of this work was to quantify the variation of chamber transparency over the period of one month of measurements and its impact on estimates of peatland net ecosystem exchange. The automated transparent closed (non-steady-state) chambers are widely used for quantifying net carbon dioxide (CO2) fluxes exchanged between different canopies and the atmosphere. However, it is known that the transparency of the chamber, and hence the amount of radiation reaching the surface, is changing over time and depends on several factors, such as solar angle, obstacles, and cleanness of the chamber surface which is exposed to the environmental conditions. The objective of this research work was to determine if the material from which the measuring chamber is made maintains constant parameters for reduction of incoming radiation in the form of photosynthetic photon flux density (PPFD) inside the chamber. Based on the obtained results, it can be stated that during the specific atmospheric conditions, the average transparency of the measuring chamber of the automatic chamber system can drop even up to 20%. If not considered, it may lead to incorrect estimation of net ecosystem exchange (NEE). In case of our experiment, non-corrected NEE flux rates were five times higher than the same fluxes after corrections. For this reason, it is important to apply correction coefficients, which allow the selection of the appropriate value for PPFD during the NEE modelling process.

DRUGAS: implantable telemetric system for measuring the portal venous pressure: assembly aspects

Developing an implantable, telemetric pressure measuring system for venous applications makes a high degree of miniaturization necessary. Thus the influence on the measurement environment is minimized and the risk of thrombosis at small flow blood velocities is decreased. But these systems are limited in terms of accuracy and resolution. The asked system requirements could only be reached by optimising the assembly and encapsulation techniques. To achieve the high degree of miniaturization numerical simulations were performed on the shape and size of the implant and led to the development of a specific metal housing consisting of two main components. A small measuring chamber will be placed into the portal vein and is rigidly fixed to a flat circular part that contains the pressure sensor chip and a transponder board and will be located outside on top of the vein. The main focus of the assembly process was based on a stress-free design and mounting of the components.