3D Printed Fused Deposition Modeling (FDM) Capillaries for Chemiresistive Gas Sensors.

This paper discusses the possible use of 3D fused deposition modeling (FDM) to fabricate capillaries for low-cost chemiresistive gas sensors that are often used in various applications. The disadvantage of these sensors is low selectivity, but 3D printed FDM capillaries have the potential to increase their selectivity. Capillaries with 1, 2 and 3 tiers with a length of 1.5 m, 3.1 m and 4.7 m were designed and manufactured. Food and goods available in the general trade network were used as samples (alcohol, seafood, chicken thigh meat, acetone-free nail polish remover and gas from a gas lighter) were also tested. The "Vodka" sample was used as a standard for determining the effect of capillary parameters on the output signal of the MiCS6814 sensor. The results show the shift of individual parts of the signal in time depending on the parameters of the capillary and the carrier air flow. A three-tier capillary was chosen for the comparison of gas samples with each other. The graphs show the differences between individual samples, not only in the height of the output signal but also in its time characteristic. The tested 3D printed FDM capillaries thus made it possible to characterize the output response by also using an inexpensive chemiresistive gas sensor in the time domain.

Fruit Quality Characteristics of Service Tree (Sorbus domestica L.) Genotypes.

In this study, agro-morphological properties, phenolic compounds, and organic acid contents in the fruits of service tree (Sorbus domestica L.) genotypes naturally grown in Türkiye (Bolu) were determined. The fruit weights of genotypes were found to be quite variable, ranging from 5.42 g (14MR05) to 12.54 g (14MR07). The highest L*, a*, and b* fruit external color values were found to be 34.65 (14MR04), 10.48 (14MR09), and 9.10 (14MR08), respectively. The highest chroma and hue values were recorded as 12.87 (14MR09) and 49.07 (14MR04), respectively. 14MR03 and 14MR08 genotypes exhibited the highest amount of soluble solid content and titratable acidity (TA) as 20.58 and 1.55%, respectively. The pH value was found to be in the range of 3.98 (14MR010)-4.32 (14MR04). Chlorogenic acid (14MR10, 48.49 mg/100 g), ferulic acid (14MR10, 36.93 mg/100 g), and rutin (14MR05, 36.95 mg/100 g) were predominant phenolic acids observed in the fruits of service tree genotypes. The predominant organic acid in all fruit samples was malic acid (14MR07, 34.14 g/kg fresh weight basis), and the highest quantity of vitamin C was detected at 95.83 mg/100 g in genotype 14MR02. Principal component analyses (%) were performed to determine the correlation between the morphological-physicochemical (60.6%) and biochemical characteristics of genotypes (phenolic compounds: 54.3%; organic acids and vitamin C: 79.9%). It was determined that measured genotypes were important genetic resources in terms of nutritional value.

Influence of drought stress and mycorrhizal (Funneliformis mosseae) symbiosis on growth parameters, chlorophyll fluorescence, antioxidant activity, and essential oil composition of summer savory (Satureja hortensis L.) plants.

Introduction: Drought stress unfavorably influences the growth and physiological traits of plants in the arid and semi-arid regions of the world. This study aimed to determine the effects of arbuscular mycorrhiza fungi (AMF; Funneliformis mosseae) inoculation on the physiological and biochemical responses of summer savory (Satureja hortensis L.) under different irrigation regimes. Methods: The first factor was different irrigation regimes, including no drought stress (100% field capacity; FC), moderate drought stress (60% FC), and severe drought stress (30% FC); the second factor included the plants without AMF (AMF0) and with AMF inoculation (AMF1). Results: The results showed that better values, higher plant height, shoot mass (fresh and dry weight), relative water content (RWC), membrane stability index (MSI), photosynthesis pigments, Fv, Fm, Fv/Fm, and total soluble proteins were obtained in the plants inoculated with AMF. The highest values were obtained for plants with no drought stress, then the plants subjected to AMF1 under 60% FC, and the lowest ones for plants under 30% FC without AMF inoculation. Thus, these properties are reduced under moderate and severe drought stress. At the same time, the utmost activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), and the highest malondialdehyde (MDA), H2O2, proline, and antioxidant activity (TAA) were achieved for 30% FC + AMF0. It was also found that AMF inoculation improved essential oil (EO) composition, also as EO obtained from plants under drought stress. Carvacrol (50.84-60.03%) was the dominant component in EO; γ-terpinene (19.03-27.33%), p-cymene, α-terpinene, and myrcene, were recognized as other important components in EO. The higher carvacrol and γ-terpinene contents were obtained from summer savory plants with AMF inoculation and the lowest for plants without AMF and under 30% FC. Conclusion: According to the present findings, using AMF inoculation could be a sustainable and eco-friendly approach to improve physiological and biochemical characteristics and the essential oil quality of summer savory plants under water shortage conditions.

Monitoring of the impact of road salting on spruce forest ecosystem in the vicinity of the highway D1 in the Bohemian-Moravian Highlands, Czech Republic.

Monitoring of pollution in the vicinity of roads connected to winter road maintenance is one of the important tools for optimising winter maintenance technology and reducing its environmental impact. The aim of this study was to determine the relationship between winter road maintenance and the increased concentration of sodium ion to characterise the harm caused by the de-icing agents on selected types of individual components grown in the Norway spruce ecosystem. The model area is located in the immediate vicinity of the D1 motorway connecting Prague and Brno (Czech Republic), at 103 km. The area is thus exposed to long-term contamination from automobile transport, and the monitoring was carried out for 3 consecutive years. A clear effect of the de-icing agents on conifers near the road has been demonstrated by the symptoms of salt damage visually observed in close proximity to the road (at a sampling distance of 5 m). The needles of these spruce trees also showed increased sodium concentrations, regardless of the age of the needles. The study also confirms that sodium accumulates in all selected components of the analysed ecosystem (moos, humus, soil). The sodium concentration has been found to decrease with increasing distance from the road for all of the components.

Assessment of Soil Contamination with Potentially Toxic Elements and Soil Ecotoxicity of Botanical Garden in Brno, Czech Republic: Are Urban Botanical Gardens More Polluted Than Urban Parks?

Though botanical gardens are an important and widely visited component of urban green spaces (UGS) worldwide, their pollution is rarely studied. The aim of this study was to assess botanical garden soil contamination and ecotoxicity and to evaluate whether urban botanical gardens are more contaminated than urban parks. Soil assessments showed serious contamination with Cd, Pb and Zn, emitted predominantly by traffic, agrochemicals and past construction and demolition waste. The discovery of hazardous historical ecological burden in the UGS calls for the necessity of detailed surveys of such areas. Despite prevailing moderate-to-heavy contamination, the soil was only slightly ecotoxic. Maximum immobilisation inhibition of Daphnia magna reached 15%. Growth of Sinapis alba L. was predominantly stimulated (73%), and Desmodesmus subspicatus Chodat was exclusively stimulated, possibly due to soil alkalinity and fertiliser-related nutrients. The hypothesis of a higher contamination of urban botanical gardens compared to urban parks was confirmed. However, urban parks can face a greater risk of soil ecotoxicity, hypothetically due to decreased activity of soil organisms resulting from adverse soil conditions caused by active recreation. The results highlight the need for an increased focus on botanical and ornamental gardens when assessing and managing UGS as areas potentially more burdened with contamination.

Sensor Systems for Detecting Dough Properties Fortified with Grape Pomace and Mealworm Powders.

The present article dealt with the fortification of plain wheat flour by the addition of grape pomace flour and mealworm larvae powder, focusing on the mineral content and selected properties of the dough. The work also analyzed the properties of one mixture in a weight combination of 80% wheat flour, 10% grape pomace, and 10% mealworm. X-ray analysis was used to measure the mineral content of calcium, iron, copper, and zinc. The properties of the individual mixture were monitored using an experimental electronic nose and a thermodynamic sensor system during the leavening. The results showed that a combination of 50% grape pomace and 50% mealworm larvae was advantageous from the viewpoint of the favorable representation of minerals. The analyzed mixture contained a high proportion of calcium (3976.7 ± 362.9 mg·kg-1), iron (209.3 ± 25.7 mg·kg-1), and copper (65.0 ± 100.1 mg·kg-1) for grape pomace as well as a high proportion of zinc (277.0 ± 21.9 mg·kg-1) for the mealworm larvae. However, this mixture showed a small change in the heat flux response when analyzed with thermodynamic sensors (lower yeast activity and worse gas formation properties resulted from the sensor characteristic with a lower response). The 100% wheat flour had the highest response, and the second highest response was recorded for a mixture of wheat flour with 10% grape pomace and 10% mealworm larvae. This combination also often had one of the highest responses when measured with an experimental electronic nose, so this combination was considered as one of the most advantageous options for processing from the mixtures mentioned in the article.

Fast Ecotoxicity Detection Using Biosensors.

The article provides information about a new device, AlgaTox developed in the R&D project sponsored by the Technology Agency (n.TA02030179) and patented in Czech Republic (CZ 305687). Its functionality is based on the use of biosensor, and its main advantage is fast response rate. The toxicity detection is achieved through precise measurement of green algae oxygen production dynamics after their exposure to light of wavelength of 680 nm. Clark sensor with a resolution of 0.05% of the equilibrium oxygen concentrations and stability at a constant pressure and temperature of 0.1% of the equilibrium oxygen concentration at the 24-h measurement is used for the oxygen detection. Laboratory testing of the device has been made using silver nitrate, substance with known inhibitory effect on algae. Real samples of aqueous soil extracts and waste sample from old dried-up industrial tailing pond enriched with insecticide have been also tested. The values of oxygen production inhibition or stimulation determined with the new device in the evaluation of real samples were up to six times higher in comparison with the corresponding values of inhibition (stimulation) of growth rates determined by standard procedure.