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Although research into ultrahigh dose-rate (UHDR) radiation therapy is ongoing, there is a significant lack of experimental measurements for two-dimensional (2D) dose-rate distributions. Additionally, conventional pixel-type detectors result in significant beam loss. In this study, we developed a pixel array-type detector with adjustable gaps and a data acquisition system to evaluate its effectiveness in measuring UHDR proton beams in real time. We measured a UHDR beam at the Korea Institute of Radiological and Medical Sciences using an MC-50 cyclotron, which produced a 45-MeV energy beam with a current range of 10–70 nA, to confirm the UHDR beam conditions. To minimize beam loss during measurement, we adjusted the gap and high voltage on the detector and determined the collection efficiency of the developed detector through Monte Carlo simulation and experimental measurements of the 2D dose-rate distribution. We also verified the accuracy of the real-time position measurement using the developed detector with a 226.29-MeV PBS beam at the National Cancer Center of the Republic of Korea. Our results indicate that, for a current of 70 nA with an energy beam of 45 MeV generated using the MC-50 cyclotron, the dose rate exceeded 300 Gy/s at the center of the beam, indicating UHDR conditions. Simulation and experimental measurements show that fixing the gap at 2 mm and the high voltage at 1000 V resulted in a less than 1% loss of collection efficiency when measuring UHDR beams. Furthermore, we achieved real-time measurements of the beam position with an accuracy of within 2% at five reference points. In conclusion, our study developed a beam monitoring system that can measure UHDR proton beams and confirmed the accuracy of the beam position and profile through real-time data transmission.

The article presents a method of purification of synthesis gas (syngas) produced as a result of biomass gasification with the use of a spray scrubber. The authors focus on the presentation of how individual elements of the geometry of a spray scrubber can influence its particle removal efficiency. The paper examines cases of dry particle removal, the use of demisters in purification process and wet scrubber collection efficiency with the use of numerical fluid mechanics (CFD). General equations are also used by authors to determine the initial predictions. The key part of the article is to present the results of the velocity and pressure distribution depending on the scrubber construction, determine the effect of the number of demisters used on the particle removal efficiency and to determine the probability of coalescence depending on the size of liquid droplets. Moreover, the authors formulate a simplified formula for the collection efficiency of a scrubber which is consistent with the results obtained from CFD calculations. The numerical results of collection efficiency were compared with experimental data from literature.

The objective of this study is to eliminate the tackiness of sticky paint particles occurring in paint booths using calcium hydroxide. It ultimately aims to identify the optimal filtration velocity to determine the optimal operation condition for particle collection in the filter. As the filtration velocity increased further in the range of 0.2–0.5 m/min, the pressure drop increased rapidly, while the cleaning efficiency, overall collection efficiency, and fractional collection efficiency tended to decrease. The filtration velocity for optimal filtration condition was identified to be 0.2 m/min.

This paper is focused on the efficiency of VAT collection under the standard credit invoice method. It discusses several approaches on how to evaluate the efficiency of the VAT system. The authors create their own indi­cator called the C-Coefficient that determines how many times must one unit of currency be checked by the financial authority to collect it into public budgets. The C-Coefficient is calculated from the data on VAT revenues and total VAT paid on all taxable supplies performed in the economy. The concrete results are shown for the Czech Republic for the period 2005 to 2018. The C-Coefficient reaches the values between 7.92 and 11.56, meaning that in the most efficient year (2018) the tax authorities had to inspect each collected CZK more than 7 times, whereas in the least ef­ficient year (2008) they had to audit each collected CZK more than 11 times. Authors also discuss what influences the C-Coefficient. Among impor­tant factors are measures against VAT fraud, especially the specific reverse charge, as well as the number of VAT payers in the pro­duction and distribution chain and the difference between the average VAT rates applicable on final and intermediate consumption.

This study assessed the level of nucleic acid persistence on the substrate pre-, and post-swabbing, in order to assess whether biological materials (touch, saliva, semen, and blood) are collected differently depending on the substrate characteristics. A total of 48 samples per deposit and substrate variety (n = 384) were assessed by tracking the persistence of nucleic acid using Diamond™ Nucleic Acid Dye (DD) staining and Polilight photography. The number of DD nucleic acid fluorescent complexes formed post-staining were counted (fluorescent count) and in conjunction with the fluorescence signal intensity (DD nucleic acid complex accumulation) used to estimate the level of nucleic acid persistence on substrates. Touch deposits have shown to be the most persistent deposit with strong adhesion capabilities on both substrate verities. Saliva displayed a higher persistence than semen and/or blood. Semen displayed a high collection efficiency as well as a high fluorescence signal intensity. Blood displayed a low persistence on both substrates with a superior collection efficiency that may also indicate a higher probability to become dislodged from surfaces given a particular activity. Our research has shown that the persistence and recovery of biological deposits is not only measurable but more importantly, may have the potential to be estimated, as such, may build an understanding that can provide valuable guidance for collection efficiency evaluations, and the assessing of the probability of particular profiles, given alternate propositions of means of transfer occurring. [Display omitted] •Touch deposits showed the highest persistence on aluminium and polypropylene.•Blood displayed the lowest persistence on aluminium.•Semen displayed the lowest persistence on polypropylene.•Substrate surface roughness impact on the deposition and persistence of deposits.•Gained insight into the persistence and recovery efficiency of trace DNA.

Fog harvesting is one of the proposed solutions to resolve the water shortage. A variety of fog collecting elements (FCEs), including woven metal meshes, were implemented in previous investigations. However, the low collection efficiency of woven metal meshes, particularly under low wind velocity conditions, is one of their drawbacks. Factors including wind velocity, liquid water content (LWC), relative humidity, and ambient temperature highly affect the amount of collected water. The present study systematically examines the collection efficiency and factors that affect different conventional flat woven metal meshes. To improve their low collection efficiency, a folded mesh configuration inspired by Licuala tree leaves in three vertex angles ( ) is proposed and examined in two different velocities. The aerodynamic efficiency of folded meshes was experimentally determined to substantiate the increase in collection efficiency. The findings indicate that utilizing folded mesh can enhance collection efficiency by enhancing aerodynamic efficiency. The maximum observed collection efficiency in our study is 19.6%, demonstrating an enhancement of over 100% compared to the flat mesh. This study shows that utilizing folded mesh has the potential to address the issue of low collection efficiency found in traditional metal meshes in a cost-effective way.

Utilizing electrostatic precipitators (ESPs) is an efficient particle removal method that sees a wide usage in industrial environments. This is mainly because of the low drop of the pressure flow, while retaining high collection efficiency, alongside being cost-effective. This paper reviewed previous works concerning optimizing the performance of single- and multi-stage ESPs by changing several design parameters and evaluating the effects on different performance indices, such as the corona power ratio, current-voltage characteristics, and overall collection efficiency. The review then goes through several modelling methodologies, showcasing their shortcomings and developments, as well as the relationship between the electrohydrodynamic (EHD) flow and the precipitation performance. The performance effects of using different electrode configurations and designs in terms of the number of electrodes, relative dimensions, spacings, channel lengths, and overall design were also reviewed.

The new generation medical impactor (NGI) is used to evaluate the aerodynamic particle size and particle size distribution of the particles after atomization of pharmaceutical preparations, which is of great significance for optimizing the inhalation adhesion site and therapeutic effect of pharmaceutical particles, and has been widely used in the field of inhalation drug preparations detection, but there is a lack of corresponding product standards and detection means. In this study, the evaluation method of physical collection efficiency based on aerodynamic particle size spectrometer was established by reforming the NGI, and the key performance evaluation of this new type of equipment was realized. The results showed that due to the influence of the detection limit of aerodynamic method (> 0.5μm), a method that can measure the number of smaller particles can be further developed to evaluate the collection efficiency of high-level sampling samples, so as to further improve the evaluation method. At the same time, the influence of inlet flow rate, filter membrane, and the influence of glycerin coating on the physical collection efficiency were explored, which has important reference significance for NGI equipment selection and instrument quality improvement.

Terahertz (THz) frequency quantum cascade lasers emitting peak powers of >1 W from a single facet in the pulsed mode are demonstrated. The active region is based on a bound-to-continuum transition with a one-well injector, and is embedded into a surface-plasmon waveguide. The lasers emit at a frequency of ∼3.4 THz and have a maximum operating temperature of 123 K. The maximum measured emitted powers are ∼1.01 W at 10 K and ∼420 mW at 77 K, with no correction made to allow for the optical collection efficiency of the apparatus.