This paper discusses the state of advancement in the development of spectroscopic methods based on the use of mid (proper) infrared radiation in the context of applications in various fields of ...science and technology. The authors drew attention to the most important solutions specific to both spectroscopy itself (ATR technique) and chemometric data processing tools (PCA and PLS models). The objective of the current paper is to collect and consistently present information on various aspects of FT-IR spectroscopy, which is not only a well-known and well-established method but is also continuously developing. The innovative aspect of the current review is to show FT-IR's great versatility that allows its applications to solve and explain issues from both the scientific domain (e.g., hydrogen bonds) and practical ones (e.g., technological processes, medicine, environmental protection, and food analysis). Particular attention was paid to the issue of hydrogen bonds as key non-covalent interactions, conditioning the existence of living matter and determining the number of physicochemical properties of various materials. Since the role of FT-IR spectroscopy in the field of hydrogen bond research has great significance, a historical outline of the most important qualitative and quantitative hydrogen bond theories is provided. In addition, research on selected unconventional spectral effects resulting from the substitution of protons with deuterons in hydrogen bridges is presented. The state-of-the-art and originality of the current review are that it presents a combination of uses of FT-IR spectroscopy to explain the way molecules vibrate and the effects of those vibrations on macroscopic properties, hence practical applications of given substances.
The properties of silk make it a promising material for medical applications, both in human and veterinary medicine. Its predominant amino acids, glycine and alanine, exhibit low chemical reactivity, ...reducing the risk of graft rejection, a notable advantage over most synthetic polymers. Hence, silk is increasingly used as a material for 3D printing in biomedicine. It can be used to build cell scaffolding with the desired cytocompatibility and biodegradability. In combination with gelatine, silk can be used in the treatment of arthritis, and as a hydrogel, to regenerate chondrocytes and mesenchymal cells. When combined with gelatine and collagen, it can also make skin grafts and regenerate the integumentary system. In the treatment of bone tissue, it can be used in combination with polylactic acid and hydroxyapatite to produce bone clips having good mechanical properties and high immunological tolerance. Furthermore, silk can provide a good microenvironment for the proliferation of bone marrow stem cells. Moreover, research is underway to produce artificial blood vessels using silk in combination with glycidyl methacrylate. Silk vascular grafts have demonstrated a high degree of patency and a satisfactory degree of endothelial cells coverage.
•Quality changes of stored biscuits related to chemical reactions occurring inside.•Correlation of spectral (FT-IR) data with data from classical methods – modeling.•Critical time of storage (CTS) – ...the highest rate of undesirable chemical processes.•Main storage factors effecting onset and rate of undesirable processes.•FT-IR advantages: accuracy, short time of measurement, environmentally friendly (no chemicals).
Commercially available Polish biscuits were stored for 10months under different storage conditions i.e. in temperatures of 5°C and 20°C. The chemical quality alteration caused by chemical reactions occurring within biscuits were studied in terms of change of composition of fat extracted from studied samples in one-month intervals. Correlation of data from standard methods e.g. gas chromatography or classic titration with FT-IR spectroscopy, was followed by calculation of four statistical models that accurately predicted peroxide value, oxidative stability, polar fraction content and unsaturated trans fatty acid content in any samples. On the basis of data obtained, scheme of chemical reactions involved in oxidation process was suggested. A critical time of storage was proposed as an indicator of the period of the highest rate of chemical changes. Among factors considered to influence oxidative stability, the following had the greatest impact: initial water content, initial fat content, and time of storage.
To mitigate methane emission from urban natural gas distribution systems, it is crucial to understand local leak rates and occurrence rates. To explore urban methane emissions in cities outside the ...U.S., where significant emissions were found previously, mobile measurements were performed in 12 cities across eight countries. The surveyed cities range from medium size, like Groningen, NL, to large size, like Toronto, CA, and London, UK. Furthermore, this survey spanned across European regions from Barcelona, ES, to Bucharest, RO. The joint analysis of all data allows us to focus on general emission behavior for cities with different infrastructure and environmental conditions. We find that all cities have a spectrum of small, medium, and large methane sources in their domain. The emission rates found follow a heavy-tailed distribution, and the top 10% of emitters account for 60–80% of total emissions, which implies that strategic repair planning could help reduce emissions quickly. Furthermore, we compare our findings with inventory estimates for urban natural gas-related methane emissions from this sector in Europe. While cities with larger reported emissions were found to generally also have larger observed emissions, we find clear discrepancies between observation-based and inventory-based emission estimates for our 12 cities.
Every application of a substance results from the macroscopic property of the substance that is related to the substance's microscopic structure. For example, the forged park gate in your city was ...produced thanks to the malleability and ductility of metals, which are related to the ability of shifting of layers of metal cations, while fire extinguishing powders use the high boiling point of compounds related to their regular ionic and covalent structures. This also applies to polymers. The purpose of this review is to summarise and present information on selected food-related biopolymers, with special attention on their respective structures, related properties, and resultant applications. Moreover, this paper also highlights how the treatment method used affects the structure, properties, and, hence, applications of some polysaccharides. Despite a strong focus on food-related biopolymers, this review is addressed to a broad community of both material engineers and food researchers.
The conservation of the common buzzard is assured by the European Union law. In Poland, this wild bird is under strict species protection and it is used as a bioindicator for heavy metals in the ...environment. A case of the fatal shooting of a buzzard with a firearm by an unidentified shooter is described here. Macroscopic evaluation, X-ray imaging, post-mortem computed tomography, ballistic examination of the isolated bullets and finally a simulation of the assumed position of the bird at the time of the shot were performed. Numerous pellets were found inside the body, together with multiple bone fractures and central nervous system trauma. The buzzard died most probably as a result of spinal cord injury from a single shot that was fired from a smoothbore hunting gun. Collected evidence was insufficient to identify the shooter, which sadly confirms that identification of the perpetrator in wildlife forensics remains low.
► Resonance mode of ECD operation was optimized for detection of CF3Cl and CF3Br. ► 50-fold amplification of the ECD signal was obtained for CF3Cl. ► 3.5-fold amplification of the ECD signal was ...obtained for CF3Br. ► Activation energies of CF3Cl and CF3Br were determined.
Atmospheric concentrations of anthropogenic trace gases, such as sulfur hexafluoride, SF6, chlorotrifluoromethane, CF3Cl, and bromotrifluoromethane, CF3Br, are increasing. Their long lifetimes and limited chemical reactivity make them attractive environmental tracers for hydrology and oceanography. While ambient SF6 concentrations can be readily measured using GC-ECD, the simultaneous analysis of CF3Cl and CF3Br is hampered due to their low ECD sensitivity. The response of a commercial ECD for those gases was enhanced using the resonance detection mode which is based on shifting the mean energy of electrons in the ECD detector towards the region where the electron-capture reaction reveals a distinct maximum. A custom electronic system enabled operation of a commercial ECD in the resonance detection mode. An approximately 50-fold amplification of the ECD signal was obtained for CF3Cl by application of high-frequency electric field (amplitude of 50V and frequency of 40MHz). For CF3Br, a 3.5-fold increase of the ECD signal was obtained, with a lower HF field (20–30V). In the case of SF6 the application of the HF field reduces the magnitude of ECD signal by a factor of 40. The electron-capture coefficients for SF6, CF3Cl and CF3Br were determined from 453 to 633K in the standard and the resonance modes. The electron-capture coefficients for CF3Cl and CF3Br increase with increasing temperature for both modes, while that for SF6 decreases slightly with increasing temperature. The application of the resonance detection mode to a commercial ECD provides an attractive and cost-effective alternative to GCMS for high-quality quantitative analyses of CF3Cl and CF3Br as environmental tracers.
Summary
Uptake of atmospheric hydrogen by soils constitutes the most important sink of this gas at the global scale. However, little is known about the strength and spatio‐temporal variability of ...this sink. We present the results of a systematic study aimed at characterizing hydrogen uptake by urban soils. The study was carried out at two field sites in Krakow, southern Poland. The measured fluxes of hydrogen to soils revealed distinct seasonality, with large values (up to 40 µmol hour−1 m−2) recorded during summer months and small values (between 5 and 10 µmol hour−1 m−2) during winter. Temperatures in the top 6 cm of the soil profile varied during the study from −9 to +24°C, while volumetric soil water content fluctuated between 15 and 50%. Measurable hydrogen fluxes were also observed when soil temperatures were less than zero. The results were interpreted in the context of seasonal changes of local climate and air and soil temperature, soil water content and amount of rainfall. Mixing conditions at the air–soil interface were also considered. Modelling of H2 uptake was performed with a two dimensional diffusion transport model, with contrasting assumptions about distribution and intensity of the hydrogen sink in the soil profile. The model results suggest that conditions in the uppermost soil layer exert a decisive control on measured hydrogen uptake rates. The measured hydrogen flux can be reproduced by the transport model only if significant reduction of the soil water content in the uppermost layer of the soil is postulated. This finding has important implications for the parameterization of hydrogen uptake rates in models of the global H2 budget.
The paper shows wind shear impact on PM10 vertical profiles in Kraków, southern Poland. The data used consist of background data for two cold seasons (September 2018 to April 2019 and September 2019 ...to April 2020) and data for several case studies from November 2019 to March 2020. The data are composed of PM10 measurements, model data, and wind speed and direction data. The background model data come from operational forecast results of the AROME model. PM10 concentration in the vertical profile was measured with a sightseeing balloon. Significant spatial variability of the wind field was found. The case studies represent the conditions with much lower wind speed and a much higher PM10 level than the seasonal average. The inversions were much more frequent than on average too. Wind shear turned out to be the important factor in terms of PM10 vertical profile modification. It is generated due to the relief impact, i.e. the presence of a large valley, blocked on one side with the hills. The analysis of PM10 profiles from all flights allows us to distinguish three vertical zones of potential air pollution hazards within the valley (about 100 m deep) and the city of Kraków: (1) up to about 60 m a.g.l. – the zone where during periods of low wind speed, air pollution is potentially the highest and the duration of such high levels is the longest, i.e. the zone with the worst aerosanitary conditions; (2) about 60–100 m a.g.l. – transitional zone where the large decrease in PM10 levels with height is observed; (3) above 100–120 m a.g.l. – the zone where air quality is significantly better than in zone 1, either due to the increase in the wind speed or due to the wind direction change and advection of different, clean air masses.
The lumbosacral region of the spine is the most susceptible to pathology in large breed dogs. The most common pathologies of this segment include intervertebral disc disease, distortion of vertebrae, ...narrowing of the lumbosacral canal and congenital defects of the spine. The aim of this study is to develop a mathematical model describing the height of each lumbosacral vertebra in the dog in relation to the position of the vertebra. For the mathematical analysis we used the results of two measurements for each lumbar vertebra. The first measurement was made from the top of the spinous process to the center of the spinal cord. The second measure-ment was made from the center of the body of one vertebra to the center of the body of the next one. It is possible to determine an approximate mathematical model that would be uniform for the entire species and would connect the height of the lumbar vertebrae with their location for every breed of the domestic dog. Despite the considerable differences in the constitutional type (small, medium and large breeds), the morphology of the lumbosacral region of the spine exhibits similar proportions. Therefore, it is possible to assess an anomaly of this spinal region objectively. These findings suggest that it is possible to determine an approximate mathematical model that would be uniform for the entire species. The present study was carried out as part of a larger project. This particular work is a pilot study.
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