Detection of Pine Cones in Natural Environment Using Improved YOLOv4 Deep Learning Algorithm

Achieving the rapid and accurate detection of pine cones in the natural environment is essential for yield estimation and automatic picking. However, the complex background and tiny target pose a significant challenge to pine cone detection. This paper proposes a pine cone detection method using the improved You Only Look Once (YOLO) version 4 algorithm to overcome these challenges. First, the original pine cone image data come from a natural pine forest. Crawler technology is utilized to collect more pine cone images from the Internet to expand the data set. Second, the densely connected convolution network (DenseNet) structure is introduced in YOLOv4 to improve feature reuse and network performance. In addition, the backbone network is pruned to reduce the computational complexity and keep the output dimension unchanged. Finally, for the problem of feature fusion at different scales, an improved neck network is designed using the scale-equalizing pyramid convolution (SEPC). The experimental results show that the improved YOLOv4 model is better than the original YOLOv4 network; the average values of precision, recall, and AP reach 96.1%, 90.1%, and 95.8%; the calculation amount of the model is reduced by 21.2%; the detection speed is fast enough to meet the real-time requirements. This research could serve as a technical reference for estimating yields and automating the picking of pine cones.

COMPARISON OF THE ADSORPTION CAPACITY OF CARBON SORBENTS FROM DIFFERENT PLANT PRECURSORS

The sorption capacity of activated carbon obtained from various plant precursors – apple wood, birch wood, pine cones and cellolignin was studied. The plant material was first subjected to carbonation by heating to a temperature of 700 °C and further exposure at this temperature. The total heating time was 8 hours. Charcoal was then subjected to steam activation at a reactor temperature of 950 °C and an activation time of 40–45 minutes. The yield of activated carbon estimated on charcoal was 42–46%. The characteristics of the porous structure were determined by the method of low-temperature nitrogen adsorption. The total specific surface area according to the BET method was (m2/g) 674, 594, 552, 552, 622 for apple wood, birch wood, pine cones, cellolignin and an industrial sample of activated carbon, respectively. Determination of the adsorption capacity by iodine adsorption methods showed that this value, depending on the source of raw materials, falls in the order: birch wood > cellolignin ≈ apple wood > pine cones. The data on the sorption of benzene characterize approximately the same range of sorption capacity: birch wood > cellolignin > pine cones ≈ apple wood. The data on the sorption capacity show that unconventional plant raw materials can be used to produce activated carbon.

Pine-cones for moss: a late Byzantine/early modern Greek version of ATU 1525E, Thieves steal from one another

Two Greek authors, Georgios Sphrantzes (fifteenth century) and Makarios Melissourgos-Melissenos (sixteenth century) refer to a variant of the type ATU 1525E, Thieves steal from one another. It is the oldest known version, and it is remarkably close to the variants later attested in Georgia and the Balkans (an area that clearly shows the features of the Byzantine cultural heritage). The comparison also makes it possible to clarify and confirm the meaning of an obscure word used in the oldest version, that of Sphrantzes, where pine-cones (koukoutzella) and moss are at the center of the exchange.

Phyllotaxis-inspired nanosieves with multiplexed orbital angular momentum

Nanophotonic platforms such as metasurfaces, achieving arbitrary phase profiles within ultrathin thickness, emerge as miniaturized, ultracompact and kaleidoscopic optical vortex generators. However, it is often required to segment or interleave independent sub-array metasurfaces to multiplex optical vortices in a single nano-device, which in turn affects the device’s compactness and channel capacity. Here, inspired by phyllotaxis patterns in pine cones and sunflowers, we theoretically prove and experimentally report that multiple optical vortices can be produced in a single compact phyllotaxis nanosieve, both in free space and on a chip, where one meta-atom may contribute to many vortices simultaneously. The time-resolved dynamics of on-chip interference wavefronts between multiple plasmonic vortices was revealed by ultrafast time-resolved photoemission electron microscopy. Our nature-inspired optical vortex generator would facilitate various vortex-related optical applications, including structured wavefront shaping, free-space and plasmonic vortices, and high-capacity information metaphotonics.

Intrapopulation variation of Siberian stone pine cones and seeds quality in spaced planting plots

For Siberian stone pine (Pinus sibirica Du Tour), a valuable nut-bearing species, the development of a system of selectively significant signs of crop quality is relevant, which is necessary for the introduction of this species into culture. Were studied the level and nature of variability in the quality of cones and seeds in 32 trees on a 42-year-old plantation with sparse planting trees of 8×8 m (south of the Tomsk region). The used system of traits reflects the sequence of the crop formation process — from cone differentiation to seed ripening. We are establish that the maximum level of variability is observed in characters characterizing deviations in seed embryogenesis, leading to an increase in the proportion of underdeveloped, empty and incomplete seeds. The level of variability of traits caused by the influence of the mother plant is much lower on the features of the establishment, differentiation, and growth of cones (the number of scales and seeds). The signs characterizing the number of different elements of the cones have a normal distribution. Positive asymmetry and kurtosis are characteristic of the distributions of signs reflecting the level of abortion of the ovules at different stages of their development. As the final selection trait with a high level of intrapopulation variability, we are proposing to use the mass of full tree seeds per unit area of the horizontal projection of the crown. The use of this trait is promising for the search for trees combining a narrow crown with a large mass of seeds.

Scots pine (Pinus sylvestris L.) cones phenotypic variation growing in provenance trials of Arkhangelsk region

The study results of phenotypic variability of Scots pine cones climatype (23 variants) in provenance trials in the Plesetsk forestry of the Arkhangelsk region, created in 1977, are given. The distribution of cones in the collection of provenance according to the forms of the apophysis proposed by Pravdin L.F. is presented, linear parameters, mass, shape coefficient and density of cones are determined. Pine provenances were conditionally divided into two groups depending on the geographical coordinates of the original plantations — western (with a latitudinal localization of climates from 68 to 55 degrees. N., but close in longitude) and eastern (with a longitude localization of climates from 40 to 73 degrees. E., but close in latitude) groups. In both groups, the distribution of cones according to the forms of the apophysis has a similar structure, the form of the apophysis f. gibba is most pronounced. The severity of the shape of the apophysis of the cone can be associated with the genetic features of the species and with the conditions of the growth place of the original plantations. Significant correlation connections between shape of cones apophysis with temperature climatic indices are established. In the collection of provenances, when growing under the same type of conditions, the length and width of the cone are equalized between offspring, however, the increase in the mass of the bump and the decrease in its density are under great genetic control, although it is associated with the geographical origin of the offspring.

Characterization of Firebrands Released From Different Burning Tree Species

The number, dimensions, and initial velocity of the firebrands released from burning Quercus suber, Eucalyptus globulus, Quercus robur, and Pinus pinaster trees were analyzed in laboratory experiments using a particle image velocimetry system. Additionally, the flame height, tree mass decay, vertical flow velocity, and temperature at the top of the trees were measured during the experiments. The relationship between the various parameters was analyzed and a good connection was found. The specimens burnt were mostly young trees, so large particles (e.g., pine cones, thick trunk barks, branches) were not included in this study as they were not present. Actually, the firebrands produced in the laboratory tests, mainly burning leaves, had a cross-sectional area of <1,600 mm2, having the potential to cause short distance spotting (up to tens of meters). Quercus trees are often considered to have a lower fire risk than eucalyptus or pine trees. However, in this study, Quercus suber and Quercus robur were the species that produced more firebrands, both in terms of number and total volume. The tests with Quercus suber were the only ones using specimens from an adult tree, confirming the great importance of the age of trees in the propensity to release firebrands. The results obtained with Quercus robur confirmed the high tendency of this species to originate spot fires at a short distance. Thus, these results are of great relevance to afforestation plans and to evaluating the risk of the presence of these species in wildland–urban interface areas.

PERSPECTIVE SEARCHES OF MEDICINAL PLANT RAW MATERIALS AS SOURCE OF POLYSACCHARIDES

The purpose of the conducted researches was studying of cones of a pine ordinary as source of polysaccharides in complex processing of raw materials. Cones of a pine ordinary were assembled during pollination. For the purpose of development of complex processing of raw materials researches on studying of the cones which remained after receiving pollen are conducted. Researches showed prospects of use of cones of a pine ordinary as source of polysaccharides after receiving pollen. The pectin content in ordinary pine cones, established by the oxalate method, was 1,2 ± 0,1%. Qualitative determination of pectin is proposed by colour reaction with solution of carbazole with alcohol 0,5%. Reaction with 10% lead (II) basic acetate was also used to identify pectin. One indicator of the detoxifying activity of pectin is the degree of esterification (ratio of esterified and free carboxyl groups). Low esterified pectins (esterification rate below 50%) are used as detoxicant. Important is the fact that the complex processing of ordinary pine cones will make it possible to obtain pectin actually from pollen production waste. In the developed scheme of complex processing of ordinary pine cones for hydrolysis-extraction of pectin-high substances from raw materials, it is proposed to use citric acid solution with pH 1,8-2,0. Methods for identifying and quantifying pectin in an object are valid. As a result of all the studies, a method was developed for producing pectin from ordinary pine cones in the complex processing of raw materials, the content of which was 1,2±0,1%, and the degree of esterification 13,20 ± 0,5%. The results of the conducted studies showed that the content of tannins in the studied raw materials of pine cones was 0,66±0,02%. As a result of all studies, a method of producing pectin from ordinary pine cones in complex processing of raw materials has been developed. The obtained results make it possible to recommend the obtained pectins as an effective detoxifying agent and a source of polysaccharides, tannins.

Investigation of element migration characteristics and product properties during biomass pyrolysis: a case study of pine cones rich in nitrogen

To further understand the element migration characteristics and product properties during biomass pyrolysis, herein, pine cone (PC) cellulose and PC lignin were prepared, and their pyrolysis behavior was determined using thermogravimetric analysis (TGA).