Application of Chemical Sensors and Olfactometry Method in Ecological Audits of Degraded Areas

Mineral excavation is a common process throughout the world. The open pits remaining after the closure of a mine require well-considered and meticulous reclamation activities aimed at restoring the environmental properties of a given area. The inspections carried out in Poland indicate numerous irregularities in implementing the reclamation process. The research in this study was conducted in six measurement series and includes both chemical and olfactometry determinations by devices: multisensor portable gas detector and field olfactometer. Statistical analysis of the results obtained show high concentrations in ambient air of both chemical compounds (NH3, VOCs, H2S, CH3SH) and odour, excluding the possibility of occurrence in the pit of only waste types contained in the administrative decision on reclamation. In addition to the unpleasant odour, the listed compounds can have dangerous effects on the health and life of living organisms. This paper presents a suitable method of control and detection of irregularities in the conducted processes. The main advantage is the relatively low cost of purchasing sensors and field olfactometers compared to other devices, and the possibility to test the polluted air in situ, without the risk of chemical processes occurring during transport of gas samples to the laboratory.

Analisis RC Detector Sebagai Sensor Partial Discharge

Partial Discharge is a localized electric discharge that only partially connects insulation between conductors, and can appear parallel or not to the conductor. Partial discharge (PD) has long been recognized as an important indication of the state of isolation in high voltage equipment. By measuring PD, a diagnosis of the degree of degradation or deterioration in the isolation conditions of a high voltage device can be determined. Partial Discharge that occurs continuously can cause damage (breakdown) on a high voltage equipment. Therefore, before a high voltage device is used, Partial Discharge detection is necessary. Partial Discharge Detection can use the Partial Discharge measurement circuit. In this study, one part of the Partial Discharge measurement series will be discussed, namely the RC detector. Hopefully, RC detector can be further developed and can be used for more accurate partial discharge detection.

UNIFORMITY OF RESULTS OF MULTIPLE MEASUREMENT SERIES DURING PREPARING A CONTROL SAMPLE FOR QUALIFICATION TESTS

The work examines the methodology for assessing the homogeneity of the control sample of interlaboratory qualification tests, which is the most important characteristic of determining its status. The criterion for assessing the homogeneity between the characterizing values of the samples is the root mean square deviation and standard deviation of the proficiency test of the control sample with the standard uncertainty of the assigned value, which is a requirement of the ISO 13528 standard. Ignoring this requirement may provoke a false assessment of the participated laboratories taking corrective action.

The spread of breathing air from wind instruments and singers using schlieren techniques

In this article, the spread of breathing air when playing wind instruments and singing was investigated and visualized using two methods: (1) schlieren imaging with a schlieren mirror and (2) background-oriented schlieren (BOS). These methods visualize airflow by visualizing density gradients in transparent media. The playing of professional woodwind and brass instrument players, as well as professional classical trained singers, were investigated to estimate the spread distances of the breathing air. For a better comparison and consistent measurement series, a single high and a single low note as well as an extract of a musical piece were investigated. Additionally, anemometry was used to determine the velocity of the spreading breathing air and the extent to which it was still quantifiable. The results presented in this article show there is no airflow escaping from the instruments, which is transported farther than 1.2 m into the room. However, differences in the various instruments have to be considered to assess properly the spread of the breathing air. The findings discussed below help to estimate the risk of cross-infection for wind instrument players and singers and to develop efficacious safety precautions, which is essential during critical health periods such as the current COVID-19 pandemic.

Revisiting Relaxation Model towards Prediction of Longterm Mechanical Behavior of Semicrystalline Fibers?

<p>Tensile testing is a well-established method to assess the maximum strength of a material, while relaxation tests are used to evaluate the viscoelastic behaviour of a polymer. Because of slow viscoelastic changes, significant measurement times are required for reliable descriptions. Therefore the relaxation tests are usually combined with lifetime prediction models to reduce the experimental load. Various traditional models use the time-temperature superposition principle while modificated relaxation models are e.g. based on the time-strain superposition principle (TSSP). Both variations require several measurement series to set up a relaxation master curve (RMC). The basic assumption is that a higher strain corresponds to a higher temperature and a longer load duration, respectively. The paper describes a new model approach which allows to predict the longterm behaviour by using a reduced number of measurements as compared to widely models. The new model is based on the well-known Maxwell model and assumes a mean relaxation time in combination with a relaxation coecient. These parameters account for the inhomogeneity of the individual polymer chains. A dimensionless number, similar to the relaxation coecient, has been successfully introduced for the Weibull distribution and the particle size distribution. The new model allows to derive master curve from one measurement series at a single strain by fitting the data to the model equation.<br></p>

Revisiting Relaxation Model towards Prediction of Longterm Mechanical Behavior of Semicrystalline Fibers?

<p>Tensile testing is a well-established method to assess the maximum strength of a material, while relaxation tests are used to evaluate the viscoelastic behaviour of a polymer. Because of slow viscoelastic changes, significant measurement times are required for reliable descriptions. Therefore the relaxation tests are usually combined with lifetime prediction models to reduce the experimental load. Various traditional models use the time-temperature superposition principle while modificated relaxation models are e.g. based on the time-strain superposition principle (TSSP). Both variations require several measurement series to set up a relaxation master curve (RMC). The basic assumption is that a higher strain corresponds to a higher temperature and a longer load duration, respectively. The paper describes a new model approach which allows to predict the longterm behaviour by using a reduced number of measurements as compared to widely models. The new model is based on the well-known Maxwell model and assumes a mean relaxation time in combination with a relaxation coecient. These parameters account for the inhomogeneity of the individual polymer chains. A dimensionless number, similar to the relaxation coecient, has been successfully introduced for the Weibull distribution and the particle size distribution. The new model allows to derive master curve from one measurement series at a single strain by fitting the data to the model equation.<br></p>

Tribodiagnostic Control of Motor Oil (MO) Properties in IVECO Crossway Buses

Within the Project VV1 "Design and application of tribodiagnostic methodologies for operation and maintenance of ground equipment of the Armed Forces of the Slovak Republic in the years 2018 - 2020, she was performed motor oil (MO) sampling series and property measurement series (MO) PETRONAS URANIA FE LS, SAE 5W-30, (O-1178), in IVECO CROSSWAY vehicles. The aim was to perform on the basis of the performed experimental measurements experimental verification of parameters of operating substances and materials of newly introduced ground military equipment.

Bioaerosol measurements over a fattening period in a pig barn focused on the presence of Staphylococcus spp.

The investigation of bioaerosols in the recent years has become more important both indoors and outdoors. Due to expanding of livestock farm capacity, raising attention is paid to this source of emissions. The objective of the present study was to estimate the distribution of bioaerosols in the animal husbandry and its surroundings. Over 2 fattening periods with different animal ages and weights, the main emphasis was put on the total concentrations of mesophilic bacteria and Staphylococcus spp., especially the species S. aureus. The bioaerosols were sucked in with an AGI-30 Impinger, and nasal and neck skinfold swab samples were collected supplementary from randomly selected pigs. From the first series of measurements, the total concentration of mesophilic bacteria was 6.2 × 105 cfu/m3 and dropped to 2.6 × 105 cfu/m3 with increasing growth of the swine. The concentration of Staphylococcus spp. was 8.8 × 104 cfu/m3 and decreased to 9.4 × 103 cfu/m3 by the end. In the empty barn, the total concentration of mesophilic bacteria was 9.1 × 104 cfu/m3 and for Staphylococcus spp., 1.1 × 104 cfu/m3. At the beginning of the second series of measurements, the total concentration of mesophilic bacteria was 6.6 × 104 cfu/m3 and dropped to 4.4 × 104 cfu/m3 with the increasing growth of the piglets. The concentrations of Staphylococcus spp. fluctuated along the second measurement series. The species Staphylococcus aureus was detected in nasal swabs of selected swine including MRSA. Temperature and humidity had no influence on the concentrations of mesophilic bacteria in the swine barn.

The detection of Alternaria solani infection on tomatoes using ensemble learning

This paper presents a detection method of Alternaria solani in tomatoes. Several machine learning models were used to detect the pathogen, such as the implementation of decision trees and ensemble learning methods. The use of these methods requires the acquisition of large volumes of data and adequate preprocessing of this data. For the presented study the dataset of hyperspectral measurements of two varieties of tomatoes was used. Measurements were split into two groups: one inoculated with the Alternaria solani pathogen and the other one was treated as the reference. Measurements were taken by the spectroradiometer in consecutive measurement series. The main part of the study was the evaluation of the decision trees and the popular ensemble learning algorithms to select the most accurate one. After subsequent iterations of the training process and adjustment of hyperparameters, satisfactory accuracy results, equal to 0.987 for random forest, were obtained. This paper also covers the examination of the spectral range required for Alternaria solani identification. From several variants, the accuracy of models based on VIS and NIR spectral range was the closest to the accuracy obtained with the whole spectrum of measured absolute reflectance.