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Taxonomy and phytogeography analysis of medicinal plants within Management Unit „Goč-Selište“
No full textThe analysis of taxonomy and phytogeography features of medicinal plants at the area of MU
„Goč-Selište“, within the protective forests of Vrnjačka Banja, was conducted during growing
season of 2023. The studied area is very significant due to the numerous functions of these
forests: water protective, ecological, economics, social and recreational. There was
established, based on detailed monitoring, presence of total 73 medicinal taxa. As for
taxonomy, total of 34 families was recorded and the greatest number of representatives
included Asteraceae (13.70 %), Lamiaceae (12.33 %) and Rosaceae (12.33 %). In terms of
floral elements, there was total of 17 found and among them the most abundant were eurasian
(31.51 %), submideuropean (19.18 %) and european (15.07 %). Among life forms
hemicryptophytes (42.47 %) and phanerophytes (24.66 %) were the most dominant, while the
other five life forms included only 1/3 of the total number. Based on the obtained results
related to taxonomy and phytogeography, we can deduce there are no significant differences
if compare with forests located in the other ecological conditions in Republic of Serbia. Over
70 % of recorded medicinal plants were herbaceous. The recommendation is to conduct
monitoring within a longer period of time (at least three consecutive growing seasons) and to
pay a special attention to some species which natural regeneration is weaker. In that way, a
significant focus should be devoted to preservation and protection of these endangered
specie
Signal Processing and Machine Learning as a Tool for Identifying Idling Noises of Different Circular Saw Blades
No full textThis study examines the possible utilization of machine learning and decision-making in the woodworking sector. This refers to the recognition of certain sounds produced during tool idling. The physical and geometric properties of the circular saw blade result in different noises being generated during idling. It was assumed that the respective circular saw blades can be recognized by these noises. The noises of three different circular saw blades were examined while idling at the same speed. In order to obtain useful data for the deep learning process, the coarse signals were subjected to frequency analysis. A total of 240 noise samples were taken for each circular saw blade and later subjected to signal processing. Frequency-power spectra were created using a custom program in Matlab Campus Edition software, such as for the spectrograms. A short Fourier transform was used to create the average spectral density plot using self-made software. The input data for the deep learning network was created in Matlab using a custom program. The GoogleNet deep learning network was used as a data classifier. After training the network, an accuracy of 97.5% was achieved in recognizing circular saw blades
Bio-Epoxy Resins Based on Lignin and Tannic Acids as Wood Adhesives-Characterization and Bonding Properties
No full textThe possibility of producing and designing bio-epoxides based on the natural polyphenol lignin/epoxidized lignin and tannic acids for application as wood adhesives is presented in this work. Lignin and tannic acids contain numerous reactive hydroxyl phenolic moieties capable of being efficiently involved in the reaction with commercial epoxy resins as a substitute for commercial, non-environmentally friendly, toxic amine-based hardeners. Furthermore, lignin was epoxidized in order to obtain an epoxy lignin that can be a replacement for diglycidyl ether bisphenol A (DGEBA). Cross-linking of bio-epoxy epoxides was investigated via FTIR spectroscopy and their prospects for wood adhesive application were evaluated. This study determined that the curing reaction of epoxy resin can be conducted using lignin/epoxy lignin or tannic acid. Tensile shear strength testing results showed that lignin and tannic acid can effectively replace amine hardeners in epoxy resins. Examination of the failure of the samples showed that all samples had a 100% fracture through the wood. All samples of bio-epoxy adhesives displayed significant tensile shear strength in the range of 5.84-10.87 MPa. This study presents an innovative approach to creating novel cross-linked networks of eco-friendly and high-performance wood bio-adhesives
Sound classification and power consumption to sound intensity relation as a tool for wood machining monitoring
No full textNon-contact process monitoring could be a powerful tool to prevent tool misuse, detect wood species, detect tool dullness and reduce electrical energy consumption-all of which could reduce production costs. The aim of this study is to identify recognizable patterns in the sound signals produced during the circular sawing of two different wood species-beech (Fagus moesiaca) and fir (Abies alba)-and to classify them in order to obtain an intelligent machining process capable of recognizing the wood species being machined. These two wood species were selected for this study due to their morphological, physical and mechanical differences. The cutting power was also recorded during the process and measured indirectly via the motor power used. A sound signal can easily be converted into an image (spectrogram), which is suitable as a data basis for the deep learning process. Several neural networks were used to classify the sounds. In order to prepare the raw audio signal for machine learning using image recognition, it was processed in several steps. The relationship between the audio and the recorded cutting power was also investigated and found to be strongly correlated, but only for audio frequencies up to 4500 Hz. Based on the results and further analysis, the classification accuracy for wood species identification varied between 98% for MobileNetV2 and 94% for the InceptionV3 deep learning network
Ålegras (Zostera marina) forsvinner langs norskekysten
No full textOver hele verden har sjøgrasenger minsket dramatisk de siste årene og blant de berørte artene er ålegras. Ålegrasenger er av stor betydning som oppvekststed for mange marine arter, blant dem torskeyngel. Dessuten bidrar de til å fange klimagassen CO2 og lagre karbon. Ålegrasenger skades av mudring og ulike fysiske inngrep i strandsonen, men de er også utsatt for sjukdommer og andre levende (biotiske) skadegjørere. Vi omtaler her funn av flere sjukdomsfremkallende mikroorganismer som vi mener skader ålegras langs norskekysten
The potential use of airbag as an alarm for occupational injuries
No full textChest injuries are rare but extremely life-threatening and can occur in all industries.
Although the widespread opinion is different, most injured people can be saved by
appropriate surgical treatment. Thanks to the use of airbags as an occupational injury
alarm, the injured worker can inform his colleagues nearby without realizing it. This alarm
is triggered if the load is more than 15 kilograms or if there is a loss of pressure in the
airbag, which indicates a strong impact in the body region where the airbag is located.
In a closed environment, the receiver that responds to this alarm is located in the inner
or outer part of the work area and warns the other workers of the resulting injury by
means of visual and acoustic signals. Airbags as occupational injury alarms can be
successfully used in various fields and working environments, especially in forestry,
agriculture, mining, construction and mechanical workshops
HOW DOES PLASTIC POLLUTION AFFECT SOIL QUALITY IN PLASTICULTURE?
No full textGrowing crops in plastic greenhouses and mulching with plastics is one of the largest sources of microplastics in the environment around the world and especially in Serbia. Plastic waste is known for its stability and recalcitrance in the environment, so it is generally assumed that standard plastic waste is not degradable. The determination of microplastics in soil is a major challenge due to the complexity of the soil matrix. The aim of the study was to show the effects of plastic particles on the chemical, physical and biological properties of arable soils. Alluvial soils from three major river basins (Danube, Morava and Sava) in Serbia, which are most affected by seasonal flooding, were selected. Soils from MP-polluted (plasticulture) and non-polluted (open field) sites, located next to each other, were sampled in 2022 from two depths 0-15 and 15-30 cm. Preliminary results showed that the physical, chemical and biological properties of the soil were significantly affected by the presence of plastics. Plastic contamination in the soil environment has an impact on organic matter cycling, global carbon dioxide production, plant production, soil properties, water quality, etc. It is time to raise awareness that the pollution of our environment with plastic waste can lead to serious disruptions of the ecosystem and its ability to fulfil its functions, such as the production of sufficient and high-quality quantities of foodThe Book of Abstracts se nalazi na linku: https://centennialiuss2024.org
Process parameter identification by sound signal processing and deep learning in wood machining
No full textSounds or noise generated during the idle and cutting of wood with specific cutting tools can provide valuable inputs for deep learning networks to identify cutting speed, feed rate, cutting depth, tool type, tool bluntness, and even the type of wood being processed. The analysis of idling noises provides a starting point for a better understanding of the interaction noises. When interacting with wood, a tool also produces characteristic noises that provide information about the fracture mechanics occurring during the cutting process, allowing us to identify cutting parameters, wood species and tool types. The wood species selected for this study were beech and fir (hardwood and softwood). The tools selected were circular saw blades (Freud LU1C 0100, LU2B 0500 and LU2C 1200), an SCM planer head with Tersa M+ blades and custom-made Gatech milling cutters (radius 125 mm, width 40 mm and rake angles of 16°, 20° and 25°). The sound signals were recorded using a DBx RTA-M measuring microphone connected to a Focusrite Scarlet SOLO USB audio interface and a PC. The signals were cut and trimmed using the WavePad Sound Editor developed by NCH Software. The measurements were performed at a sampling rate of 44100 Hz. These recordings were converted into power spectra using a one-sided Fast Fourier Transform (FFT) and later into spectrograms using a wavelet transform. All these tasks were performed with the software MatLab R2023b, Campus Edition. Various neural networks were used to classify the sounds, including MobileNetV2, VGG19, Dense-Net, Squeeze-Net, Res-Net, InceptionV3 and GoogleNet
Determination of the density of pvc polymer materials by the immersion method
No full textU ovom radu je izvrÅ¡eno odreÄ‘ivanje gustine serije Ävrstih, nećelijskih komercijalno upotrebljivih i oblikovanih polimernih materijala (tzv. plastika). Primenjena je metoda odreÄ‘ivanja gustine nećelijskih polimernih materijala (plastike) u skladu sa meÄ‘unarodnim standardom ISO 1183-1: 2019, Deo A: Metoda uranjanja u teÄnost. Na osnovu rezultata prethodnih istraživanja, pretpostavljeno je da su ispitivani uzorci izraÄ‘eni od polimernih materijala na bazi PVC (krutog ili fleksibilnog). Prethodno istraživanje je obuhvatalo procenu vrste/tipa plastiÄne mase korišćenjem testa gorenja u svojstvu brze metode identifikacije polimernih materijala. Pretpostavljeno je takoÄ‘e, da će se primenom odabrane metode, dobiti rezultati koji odgovaraju gustini PVC polimera sa dodacima i/ili plastifikatorima, a koja se kreće u intervalu od 1,44 - 1,48 g/cm³. Gustina PVC polimera može varirati u odnosu na gustinu tipiÄnog PVC u zavisnosti od korišćenih dodataka npr. filera, stabilizatora boje, Å¡tampe, itd. i naroÄito, od upotrebe plastifikatora. Na osnovu dobijenih rezultata odreÄ‘ivanja gustine korišćenom metodom, može se smatrati da je preliminarno potvrÄ‘ena pretpostavka dobijena testom gorenja (prethodno istraživanje) prema kojem su uzorci izraÄ‘eni od PVC polimera. Uzorci se meÄ‘usobno razlikuju prema gustini materijala, na koju znatno utiÄe prisustvo dodataka plastiÄnim masama i plastifikatora. Može se smatrati da dobijena odstupanja gustine uzoraka u ispitivanoj seriji potiÄu od razlike u sastavu i u strukturi ispitivanih materijala, Å¡to je u skladu sa pretpostavkama iz korišćene literature
Effectiveness of Photinia × fraseri 'Red Robin' in the urban landscape: towards of climate change
No full textThe paper explores the effectiveness of Photinia × fraseri 'Red Robin' in the urban environment of
Belgrade, particularly in light of a modified temperate-continental climate. The research focuses on
assessing how urban design and climate change affect the phenological events of Red Robin
Christmas Berry across four locations in Belgrade. By analyzing climatic variables such as
accumulated cold hours and their correlations with phenological patterns of flowering, the study
unveils the substantial impact of insolation, air temperature, and urban layout on these phenophases.
The findings underscore the significance of site selection in optimizing the delivery of ecosystem
services