Decontamination Effect of Hypochlorous Acid Dry Mist on Selected Bacteria, Viruses, Spores, and Fungi as Well as on Components of Electronic Systems.

This publication presents the effect of hypochlorous acid dry mist as a disinfectant on selected bacteria, viruses, spores, and fungi as well as on portable Microlife OXY 300 finger pulse oximeters and electronic systems of Raspberry Pi Zero microcomputers. The impact of hypochlorous acid on microbiological agents was assessed at concentrations of 300, 500, and 2000 ppm of HClO according to PN-EN 17272 (Variant I). Studies of the impact of hypochlorous acid fog on electronic components were carried out in an aerosol chamber at concentrations of 500 ppm and 2000 ppm according to two models consisting of 30 (Variant II) and 90 fogging cycles (Variant III).

Surface Modification of ZnO Nanotubes by Ag and Au Coatings of Variable Thickness: Systematic Analysis of the Factors Leading to UV Light Emission Enhancement.

Surface modification by plasmonic metals is one of the most promising ways to increase the band-to-band excitonic recombination in zinc oxide (ZnO) nanostructures. However, the metal-induced modulation of the UV light emission depends strongly on the production method, making it difficult to recognize the mechanism responsible for charge/energy transfer between the semiconductor and a metal. Therefore, in this study, the ZnO/Ag and Au hybrids were produced by the same, fully controlled experimental approach.

Fluorescence Methods for the Detection of Bioaerosols in Their Civil and Military Applications.

The article presents the history of the development and the current state of the apparatus for the detection of interferents and biological warfare simulants in the air with the laser-induced fluorescence (LIF) method. The LIF method is the most sensitive spectroscopic method and also enables the measurement of single particles of biological aerosols and their concentration in the air. The overview covers both the on-site measuring instruments and remote methods.

Designing porous photonic crystals for MIR spectral region-a deeper insight into the anodic alumina layer thickness versus charge density relation.

The mid-infrared region (MIR) is crucial for many applications in security and industry, in chemical and biomolecular sensing, since it contains strong characteristic vibrational transitions of many important molecules and gases (e.g. CO, CH, CO).

Structural stability and optical properties of 1D photonic crystals based on porous anodic alumina after annealing at different temperatures.

Porous anodic alumina (PAA) photonic crystals with a photonic stop-band (PSB) placed in the mid-infrared (MIR) spectral region represent a promising approach for increasing of gas sensors sensitivity. An onion-like layered distribution of anionic impurities is a hallmark of PAA, and its presence is generally considered to demarcate the boundary between transparent and opaque ranges in the infrared spectral region. Here, we study the effect of annealing in the temperature range of 450 °C-1 100 °C on the structural stability and optical properties in photonic crystals based on PAA fabricated by pulse anodization in oxalic acid.

The Multi-Gas Sensor for Remote UAV and UGV Missions-Development and Tests.

In this article, we present a versatile gas detector that can operate on an unmanned aerial vehicle (UAV) or unmanned ground vehicle (UGV). The device has six electrochemical modules, which can be selected to measure specific gases, according to the mission requirements. The gas intake is realized by a miniaturized vacuum pump, which provides immediate gas distribution to the sensors and improves a fast response.

Estimation of nominal ocular hazard distance and nominal ocular dazzle distance for multibeam laser radiation: publisher's note.

This publisher's note corrects funding information in Appl. Opt.60, 6414 (2021) APOPAI0003-693510.

Estimation of nominal ocular hazard distance and nominal ocular dazzle distance for multibeam laser radiation.

This paper presents a method of estimation of the nominal ocular hazard distance (NOHD) and the nominal ocular dazzle distance (NODD) for multibeam laser radiation. For the analysis, laser beams propagating in the same optical path (overlapping) but with different wavelength, power, and divergences in two perpendicular planes were assumed. To the authors' best knowledge, such a comprehensive analysis of multiple beams, considering the above parameters, is being presented for the first time.

Comparison of Low-Cost Particulate Matter Sensors for Indoor Air Monitoring during COVID-19 Lockdown.

This study shows the results of air monitoring in high- and low-occupancy rooms using two combinations of sensors, AeroTrak8220(TSI)/OPC-N3 (AlphaSense, Great Notley, UK) and OPC-N3/PMS5003 (Plantower, Beijing, China), respectively. The tests were conducted in a flat in Warsaw during the restrictions imposed due to the COVID-19 lockdown. The results showed that OPC-N3 underestimates the PN (particle number concentration) by about 2-3 times compared to the AeroTrak8220.

Fabrication of Porous Anodic Alumina (PAA) by High-Temperature Pulse-Anodization: Tuning the Optical Characteristics of PAA-Based DBR in the NIR-MIR Region.

In this work, the influence of various electrochemical parameters on the production of porous anodic alumina (PAA)-based DBRs (distributed Bragg reflector) during high-temperature-pulse-anodization was studied. It was observed that lowering the temperature from 30 to 27 °C brings about radical changes in the optical performance of the DBRs. The multilayered PAA fabricated at 27 °C did not show optical characteristics typical for DBR.

Influence of Anodization Temperature on Geometrical and Optical Properties of Porous Anodic Alumina(PAA)-Based Photonic Structures.

In this work, the influence of a wide range anodizing temperature (5-30 °C) on the growth and optical properties of PAA-based distributed Bragg reflector (DBR) was studied. It was demonstrated that above 10 °C both structural and photonic properties of the DBRs strongly deteriorates: the photonic stop bands (PSBs) decay, broaden, and split, which is accompanied by the red shift of the PSBs. However, at 30 °C, new bands in transmission spectra appear including one strong and symmetric peak in the mid-infrared (MIR) spectral region.

Structural and Optical Characterization of ZnS Ultrathin Films Prepared by Low-Temperature ALD from Diethylzinc and 1.5-Pentanedithiol after Various Annealing Treatments.

The structural and optical evolution of the ZnS thin films prepared by atomic layer deposition (ALD) from the diethylzinc (DEZ) and 1,5-pentanedithiol (PDT) as zinc and sulfur precursors was studied. A deposited ZnS layer (of about 60 nm) is amorphous, with a significant S excess. After annealing, the stoichiometry improved for annealing temperatures ≥400 °C and annealing time ≥2 h, and 1:1 stoichiometry was obtained when annealed at 500 °C for 4 h.

Fast, reagentless and reliable screening of "white powders" during the bioterrorism hoaxes.

The classification of dry powder samples is an important step in managing the consequences of terrorist incidents. Fluorescence decays of these samples (vegetative bacteria, bacterial endospores, fungi, albumins and several flours) were measured with stroboscopic technique using an EasyLife LS system PTI. Three pulsed nanosecond LED sources, generating 280, 340 and 460nm were employed for samples excitation.

Comparison of fluorescence spectroscopy and FTIR in differentiation of plant pollens.

Spectroscopic techniques are under investigation on possibility of differentiation of airborne particles. This paper describes pollen discrimination among others bio-particles in laboratory conditions. Pollen samples were characterized with UV-Vis fluorescence, drift and KBr pellet techniques of infrared spectroscopy.

Classification of the biological material with use of FTIR spectroscopy and statistical analysis.

Rapid detection and discrimination of dangerous biological materials such as bacteria and their spores has become a security aim of considerable importance. Various analytical methods, including FTIR spectroscopy combined with statistical analysis have been used to identify vegetative bacteria, bacterial spores and background interferants. The present work discusses the application of FTIR technique performed in reflectance mode using Horizontal Attenuated Total Reflectance accessory (HATR) to the discrimination of biological materials.