976Screening for cervical cancer with Human Papillomavirus testing: stand-alone is preferable over co-testing with cytology

Background Cervical cancer screening can be conducted with cytology and Human Papillomavirus (HPV) testing but few studies have compared the latter directly to concomitant testing (co-testing). We compared these strategies to determine appropriate screening. Methods Within a randomised population-based cohort study conducted around Mainz, Germany, eligible women (≥30 years) were screened via Pap smear, liquid-based cytology (LBC) and HPV testing (HC2) and HPV genotyped post hoc (PCR). These tests formed three strategies: cytology (Pap or LBC) and HPV (HC2 or PCR) stand-alone and co-testing. Screen positives and 5% negative women were invited to colposcopy. Absolute and relative sensitivity, specificity, false positive rates (FPR) and number needed to colposcopy to detect one lesion (NNC) were calculated. Estimates were crude and verification bias-adjusted using stratified sampling with bootstrapped confidence intervals. Results Of 2,627 screened women, cytology stand-alone demonstrated lowest sensitivities (47%) and highest specificities (97%-99%) while HPV stand-alone demonstrated higher sensitivities (79%-95%) but lower specificities (94%-95%). Co-testing increased sensitivity (84%-99%) but not specificity (92%-95%). Relative sensitivities were similar between crude and adjusted estimates, with greater detection via HPV-based strategies. Specificity of co-testing with LBC relative to HPV stand-alone was near unity (0.99, 95% CI 0.99-1.00) but significantly lower than unity with Pap co-testing. FPR and NNC were greatest under co-testing. Conclusions HPV stand-alone screening in women over 30 years appears appropriate over co-testing as a screening strategy. Key messages Co-testing for cervical cancer does not appear to add any benefit in detection and may introduce unnecessary harms compared to HPV stand-alone screening.

Badania porównawcze liniowych ładunków kumulacyjnych

The fireground tests are the best method for verifying the operation effectiveness of the entire shooting device or its component parts in real conditions. The purpose of the fireground tests presented herein was the physical verification of linear shaped charge (LSC) ability to perforate multi-layered target, reflecting the material and geometrical conditions of a borehole. The series of shooting tests included tests of three types of linear shaped charges selected for use in perfo-fracturing devices. The following shaped charges were tested: LSC in lead enclosure, having φ = 40 mm circular cross-section with shaped recess; LSC with copper liner in 20/30 mm steel trapezoid enclosure; LSC with liner made of solid copper, in 20/40 mm steel trapezoidal enclosure.During testing, the cumulative jet velocity was recorded using voltage type probes, arranged between the individual layers of a target composed of steel and concrete materials. The research method adapted for the project purposes was aimed at verification of the following thesis: whether the proposed shaped charges fulfil the technical and performance conditions for their effective application in the oil industry. The criterion adopted was the ability – or lack of ability – to perforate the multi-layered barrier in the form of two steel plates and concrete casting. The testing stand, single-use by its nature, was each time composed of concrete block having 400 mm ´ 250 mm ´ 150 mm dimensions and 20 MPa static compressive strength, on which two steel plates were placed parallel to each other with 20 mm spacing. The thickness of the plates was 5 mm and 10 mm respectively. The tested shaped charge was placed on the top steel plate at a distance of one calibre – that is the distance equal to the opening of the trapezoidal shaped charge and full diameter of circular cross-section charge. Furthermore, within media interface planes (steel/air, air/steel; steel/concrete), the set of voltage-type measuring probes was installed, in the form of single electric wires (φ = 0.25 mm). At an instant when they break (circuit break) as a result of cumulative jet operation, voltage drop in the subsequent measuring probes will act as a logical gate of start-stop type, or in other words the zero-one (0–1) type gate. The readings of individual probes breakage times allowed in addition to determine the velocity of the cumulative jet and to estimate its braking dynamics while passing through the subsequent elements of multi-layered target.

Testing of Alginate/Chitosan/Glass Bubbles Adsorbent for Copper Removal from Wastewater

The present paper reported the obtaining of an environmental friendly adsorbent based on sodium alginate, chitosan and glass bubbles. CaCl2 was used as crosslinking agent for sodium alginate favoring the interactions by physical bonds between the negative groups (-COO) of biopolymer and the Ca ions. The experimental study to determine the Cu(II) uptake using an atomic absorption spectrometer was conducted in the testing stand at the 1:50 and 1:100 ratios between the adsorbent mass and the amount of pollutant in solution. The number of cycles of regeneration of the adsorbent material was also evaluated. The characterization of alginate/chitosan/glass bubbles adsorbent by scanning electron microscopy (SEM) coupled with energy dispersive spectrometer (EDS) and Fourier transform infrared spectroscopy (FTIR) showed that the Cu(II) was found out on the surface of adsorbent.

Antarctic subglacial drill rig. Part II: Ice and Bedrock Electromechanical Drill (IBED)

A new, modified version of the cable-suspended Ice and Bedrock Electromechanical Drill (IBED) was designed for drilling in firn, ice, debris-rich ice and rock. The upper part of the drill is almost the same for all drill variants and comprises four sections: cable termination, a slip-ring section, an antitorque system and an electronic pressure chamber. The lower part of the IBED comprises an auger core barrel, reamers, a core barrel for ice/debris-ice drilling and a conventional geological single-tube core barrel or custom-made double-tube core barrel. First, the short and full-scale field versions of the IBED were tested at an outdoor testing stand and a testing facility with a 12.5 m-deep ice well. Then, in the 2018–2019 summer season, the IBED was tested in the field at a site ~12 km south of Zhongshan Station, East Antarctica, and a ~6 cm bedrock core was recovered from a 198 m-deep borehole. A total of 18 d was required to penetrate the ice sheet. The retrieved core samples of blue ice, basal ice and bedrock provided valuable information regarding the Earth's paleo-environment.

Testing stand of PMR analyzer for measuring viscosity and composition of multicomponent liquids by PMR relaxometry method

The article describes a bench for studying a system of a flow analyzer based on nuclear (proton) magnetic resonance (PMRA), used for the operational control of proton-containing multicomponent liquids (oils, fuels, oil and chemical products) and mixtures for viscosity and composition (concentration of asphaltenes and resins ) during oil production, oil preparation and use at energy facilities in the analysis of liquid fuel. This article also looks at the equipment that is used to control oil parameters with PMR-Relaxometry. Particular attention should be paid to the analysis of physical and chemical properties of oil components with the use of PMR. The use of sampling equipment for the purpose of controlling the rapid flow of oil parameters by the PMR method will eliminate phase separation in the sampling device and eliminate clogging with waste sediments, ensure efficient homogenization of the fluid flow in the sampler, as well as automate the measurement process.

THERMOELECTRIC SYSTEM FOR PROVIDING A HEAT REGIME FOR MODULAR ELECTRONIC EQUIPMENT

Objectives. The article discusses a thermoelectric cooling system (TECS) for ensuring the thermal regime of modular electronic equipment (MEE) located in a cabinet. The main task of the experimental studies is to determine the temperature dependencies of the air-cooled heat-generating elements of a printed circuit board simulator according to TEСS parameters.Method. In order to conduct experimental studies of a thermoelectric cooling system for printed circuit boards in cassette units using a thermoelectric cooling system, a prototype designed and manufactured in the laboratory was studied on a testing stand.Result. The directions of constructive solutions for using a TECS device are presented along with a description of the testing stand and procedure. The dependencies of the temperature of the printed circuit board simulator on the heat power taken away by the TECS are considered along with the temperatures of hot and cold junctions, the air flow velocity and the distance between the electronic boards.Conclusion. The operability of the developed MEE cooling system is confirmed by the experimental studies; the specified cooling method has advantages over conventional forced or natural method and can achieve the temperatures required by the technical operating conditions; when choosing a fan to provide forced circulation of the air flow in the system, it is necessary to take into account the speed of the air flow in the channel; it is necessary to reserve the power of the power supply for the TECS operation in proportion to the power of the heat sources. An important additional point for the functioning of the thermoelectric cooling device is the necessity of ensuring the effective removal of heat from the hot junctions of the thermoelectric module without which it is impossible to use the proposed system.

DYNAMIC STRENGHT TESTS OF MATERIALS FROM TUNGSTEN HEAVY ALLOYS DESIGED FOR PENETRATORS OF APFSDS-T PROJECTILES

The paper presents results of strength tests for tungsten heavy alloys (WHA) designated for the rods of APFSDS–T kinetic projectiles. The strength tests of WHA materials were carried out in conditions of heavy dynamical loads i.e. by the firing. The paper gives a theoretical concept for the identification of stresses within the critical cross-sections of the investigated projectile, and a description of a testing stand which was specially prepared and equipped with 30 mm smooth bore ballistic barrel, and description of methodology and test results. It was especially interesting to test the material against various dynamical loads originating both from the forces of gas pressure and the crosswise forces occurring at the projectile’s move in the barrel.

POWDER GASES MAXIMAL PRESSURE MEASUREMENT METHODS USED AT FIRING ON TESTING STAND FOR LEOPARD 2A4 TANK 120 MM GUN

The paper describes a question of measuring the maximum pressure of powder gases in the barrel of 120 mm L44 Leopard 2A4 tank gun in the Institute’s testing position which, in opposite to the thank, deploys two independent methods of simultaneous measurement. The paper compares the measurement methods, the first based on placement of crushing devices directly inside the tested cartridge, and the second on deployment of a piezoelectric sensor assembled into a specially made seat in the gun’s cartridge chamber. Preparation of testing equipment and permanent monitoring of its technical condition to secure the accuracy of measurement of maximum pressure for powder gases is described. Aggregated test results of 120 mm ammunition are used to compare the deployed methods regarding (among others) the repeatability of results, reliability of the measuring equipment, and the time needed to its preparation and to the measurement at the gun site. Recommending of only one from described methods for the application may be difficult as there are many factors affecting the measurement of the maximal pressure of powder gases in the barrel bore.