Experimental studies of potential improvements in the forest regeneration capabilities of "seed-containing aerial darts"

2000 ◽  
Vol 76 (3) ◽  
pp. 406-418 ◽  
Author(s):  
A. D. Wood
Keyword(s):  
Forest Regeneration ◽  
Field Experiments ◽  
Experimental Studies ◽  
Burned Areas ◽  
Spaced Seeds ◽  
Potential Applicability ◽  
Simulated Field ◽  
Ground Penetrating ◽  
Configuration Changes ◽  
Aerial Seeding

An evolving forest regeneration technique, based on the use of a "seed-containing aerial dart" (SCAD), provides for the delivery of seeds by helicopter through the distribution of darts, which serve as ground-penetrating containers for individual seeds. While many biological and technological aspects of this aerial sowing technique have been previously documented, the hitherto unpublished results of some growth experiments, carried out over a five-year period, are believed to offer the key to any future development. These simulated field experiments, although small in scale, demonstrate means for greatly improving the prospects for regeneration using aerial darts. Such means include dart configuration changes to provide for axially spaced seeds and the addition of slow-release fertilizer, when not in direct contact with seeds within the growth medium. Darts sown in the fall on mechanically undisturbed ground are shown not to be subject to frost heaving and lead to much earlier germination and faster growth than occurs with spring sowing. The presence of a surface layer of organic material is shown to be extremely beneficial in promoting vigorous seedling growth. The results confirm the potential applicability of the technique to sites, such as recently burned areas, with these characteristics, where acceptable regeneration performance is not an unrealistic objective. Key words: reforestation, regeneration, aerial reforestation, aerial seeding, aerial sowing, aerial darts, seeded darts, seed-containing darts, seed-containing aerial darts, helicopter seeding, helicopter sowing

scholarly journals Experimental and Theoretical Study of the Axial Distribution of Solid Phase Particles in a Fluidized Bed

2021 ◽  
Vol 64 (4) ◽  
pp. 349-362
Author(s):  
A. V. Mitrofanov ◽  
V. E. Mizonov ◽  
N. S. Shpeynova ◽  
S. V. Vasilevich ◽  
N. K. Kasatkina
Keyword(s):  
Fluidized Bed ◽  
Field Experiments ◽  
Solid Phase ◽  
Cell Model ◽  
Experimental Studies ◽  
Parametric Identification ◽  
Resistance Coefficient ◽  
Model Material ◽  
Spherical Particles ◽  
Axial Distribution

The article presents the results of computational and experimental studies of the distribution of a model material (plastic spherical particles with a size of 6 mm) along the height of a laboratory two-dimensional apparatus of the fluidized bed of the periodic principle of action. To experimentally determine the distribution of the solid phase over the height of the apparatus, digital photographs of the fluidized bed were taken, which were then analyzed using an algorithm that had been specially developed for this purpose. The algorithm involved splitting the image by height into separate rectangular areas, identifying the particles and counting their number in each of these areas. Numerical experiments were performed using the previously proposed one-dimensional cell model of the fluidization process, constructed on the basis of the mathematical apparatus of the theory of Markov chains with discrete space and time. The design scheme of the model assumes the spatial decomposition of the layer in height into individual elements of small finite sizes. Thus, the numerically obtained results qualitatively corresponded to the full-scale field experiment that had been set up. To ensure the quantitative reliability of the calculated forecasts, a parametric identification of the model was performed using known empirical dependencies to calculate the particle resistance coefficient and estimate the coefficient of their macrodiffusion. A comparison of the results of numerical and field experiments made us possible to identify the most productive empirical dependencies that correspond to the cellular scheme of modeling the process. The resulting physical and mathematical model has a high predictive efficiency and can be used for engineering calculations of devices with a fluidized bed, as well as for setting and solving problems of optimal control of technological processes in these devices for various target functions.

Exposure of Caged Biomphalaria glabrata (Say) to Investigate Dispersion of Miracidia of Schistosoma mansoni Sambon in Outdoor Habitats in St. Lucia

1972 ◽  
Vol 46 (4) ◽  
pp. 297-306 ◽  
Author(s):  
Edward Suchart Upatham
Keyword(s):  
Schistosoma Mansoni ◽  
Field Experiments ◽  
Natural Habitat ◽  
Biomphalaria Glabrata ◽  
Field Conditions ◽  
Laboratory Studies ◽  
Infection Rates ◽  
Random Fashion ◽  
Simulated Field ◽  
Transmission Studies

1. Laboratory studies showed two types of cages to be suitable for exposing uninfected B. glabrata in field habitats as a means of locating S. mansoni miracidial infestations.2. Tests conducted in tanks under simulated field conditions showed that miracidia moved away from the point of inoculation in non-random fashion and congregated at the margins of the tanks.3. In a natural habitat, miracidia located and infected caged snails at distances of 33 cm vertically and 106·7 cm horizontally.4. The pattern of infection was similar in the simulated field and field experiments, but field infection rates were lower.5. For transmission studies in field habitats, caged laboratorybred snails should be placed at the margin of the habitat to ensure the maximum snail-miracidium interaction.

Detection of tunnels and boulders using shallow SH-SH reflected seismic waves

2019 ◽  
Vol 38 (6) ◽  
pp. 436-441 ◽  
Author(s):  
André J.-M. Pugin ◽  
Kevin Brewer ◽  
Timothy Cartwright ◽  
Steven L. Sargent
Keyword(s):  
Seismic Waves ◽  
Field Experiments ◽  
Sh Waves ◽  
Additional Advantage ◽  
Seismic Surveys ◽  
Shallow Seismic ◽  
Diffracted Waves ◽  
Seismic Sections ◽  
Ground Penetrating ◽  
Abandoned Coal Mine

We present three case studies on detecting buried glacial boulders, a sewage tunnel, and abandoned coal mine tunnels using shear-wave reflection methods. The seismic signature of such subsurface features is in the form of an isolated diffraction, distinctly recognized on seismic sections obtained from shallow seismic surveys using a transverse horizontal (H2) source and a multichannel landstreamer that consists of H2 geophones. We used H2 impulsive and vibrator sources with varying bandwidth. Based on field experiments with multicomponent recordings, we determined that the H2-H2 source-receiver configuration is the most optimal to generate downgoing horizontally polarized shear (SH) waves and upcoming SH reflected and diffracted waves. A shallow SH-SH image using a microvibe high-frequency sweep exhibits a wavelength between 1 and 2 m, which is comparable to that of a ground-penetrating radar image with the additional advantage of deeper penetration.

scholarly journals Radon over Kimberlite Pipes: Surface Field Experiments and Calculations of Vertical Diffusion (Arkhangelsk Diamondiferous Province, NW Russia)

2021 ◽  
Vol 11 (24) ◽  
pp. 11765
Author(s):  
Evgeny Yakovlev ◽  
Andrey Puchkov
Keyword(s):  
Field Experiments ◽  
Gas Permeability ◽  
Sedimentary Rocks ◽  
Experimental Studies ◽  
Physical Parameters ◽  
Vertical Diffusion ◽  
Diffusion Transfer ◽  
Emanation Method ◽  
Kimberlite Field ◽  
Made In

We present the results of field and experimental studies to assess the influence on the formation of the radon field over the kimberlite pipes of the Arkhangelsk diamondiferous province. Measurements were made in the field to establish the radon radiation in the soil air and the gas permeability of soils in the area of the Chidvinskaya pipe. Experimental work was aimed at determining the radiation and physical parameters of the rocks occurring within the kimberlite field. Based on a set of field and experimental data, a model of the diffusion transfer of radon in the area of the Chidvinskaya pipe was calculated for three profiles, represented by the rocks of the pipe, sedimentary rocks of the exocontacts of the pipe, and host sandy and clay sedimentary rocks. The results of the calculations show that the rocks of the exocontacts of the pipe have the greatest potential for increased radon radiation. The calculated values of the radon radiation produced by these rocks exceeded 9000 Bq·m−3. The diatreme kimberlites produced the lowest radon radiation. We showed that the source of the increased values of radon radiation is the rocks of the pipe’s exocontacts. This fact will make it possible to use the emanation method as an additional one for the search for kimberlite pipes.

scholarly journals Frequency components of radargrams in analyses of shallow soil cavities

2018 ◽  
Vol 7 (2.13) ◽  
pp. 127
Author(s):  
Daniliev S.M ◽  
Danilieva N.A
Keyword(s):  
Electromagnetic Wave ◽  
Ground Penetrating Radar ◽  
Large Scale ◽  
Experimental Studies ◽  
Technical Condition ◽  
Filling Material ◽  
Field Frequency ◽  
Inverse Fourier Transformation ◽  
Industrial Buildings ◽  
Ground Penetrating

The urgency of the issue being studied is determined by widespread large-scale implementation of ground penetrating radar (GPR) method within the study practice of technical state of various engineering-geological sites over a long operational period. Such buildings and structures as dams, architectural landmarks, residential and industrial buildings, temples and churches, roadways and takeoff runways may be referred to main engineering and geological sites which have been studied via ground penetrating radar method. Cracks of different length, orientation and opening, as well as cavities of various localization, being distinguished by filling material, are the main types of irregularities in the above-mentioned sites, which were being formed in the process of prolonged or improper operation. However, due to vastness of the irregularities being studied and the impossibility to include all the types of possible defects into this article, we have settled on the cavities which are the most commonly encountered in the course of practice only. This article considers the approach to analysis of the electromagnetic wave field frequency characteristics being applied during conducting ground penetrating radar studies of irregularities in the structure of engineering-geological sites on the basis of the results of electromagnetic wave fields mathematical simulation, and of the results obtained in experimental studies at real engineering-geological sites as well. There has been proposed a method based of inverse Fourier transformation for studying spectrum shift in georadargrams. The georadargram is a set of registered signals, which is obtained during even movement of the georadar along the survey line. Due to that, this article is aimed at attraction of analysis of wave electromagnetic field attributes in addition to standard methods of ground penetrating radar (GPR) data processing and interpretation, which allows to extend significantly prospect capabilities of GPR method by obtaining extra data on heterogeneous zones parameters at engineering and geological sites, and, thus, proceed from qualitative notions on technical condition of studied object to quantitative ones.  

scholarly journals OVERVIEW OF DESIGNS OF TREE-PLANTING MACHINE FOR OPEN AREAS AND CLEARED FELLING

2020 ◽  
Vol 8 (1) ◽  
pp. 29-34
Author(s):  
S. Bubnov ◽  
Sergey Malyukov ◽  
Aleksey Aksenov
Keyword(s):  
Natural Regeneration ◽  
Forest Regeneration ◽  
Economic Value ◽  
Root Systems ◽  
Tree Planting ◽  
Burned Areas ◽  
Priority Task ◽  
Long Time ◽  
Natural Forest Regeneration

Reforestation is the main, priority task of the modern forest complex. Natural forest regeneration has long been considered a priority. Natural regeneration, as a way of reforestation, has a number of significant drawbacks. Firstly, the natural regeneration of forests in burned areas and deforestation does not occur immediately after deforestation, but over a fairly long time ̶ reforestation period, during which various unfavorable processes ̶ soil erosion, sodding develop on an unforested area. Secondly, natural renewal quite often leads to a change of species, i.e. desired valuable breeds do not grow. As a result, the territory is overgrown with minor soft-leaved species that have low economic value. Mechanized landing, i.e. artificial reforestation, also has a number of disadvantages. Therefore, planting operations carried out under various conditions are the most labor-intensive and responsible operations. The technological process of planting seedlings and seedlings of various tree species with both open and closed root systems is presented. The analysis of existing designs of forest planting machines for open areas, fires and clearings is carried out. Deficiencies were identified that affect the quality of the planting process and reduce the survival rate of planted seedlings and seedlings.

scholarly journals Establishment of the dependence of the strength indicator of the composite material of pressure hoses on the character of single damages

2021 ◽  
Vol 6 (1 (114)) ◽  
pp. 21-27
Author(s):  
Sergii Nazarenko ◽  
Galina Kushnareva ◽  
Natalia Maslich ◽  
Ludmila Knaub ◽  
Nataliia Naumenko ◽  
...  
Keyword(s):  
Field Experiments ◽  
A Priori ◽  
Experimental Studies ◽  
Pressure Head ◽  
Longitudinal Direction ◽  
Experiment Planning ◽  
Emergency Rescue ◽  
Acceptable Model ◽  
Inner Diameter ◽  
Priori Information

Experimental studies are presented and the dependence of the change in the strength of the material of a pressure head fire hose of type T with an inner diameter of 77 mm in the longitudinal direction is established, taking into account single damages. The work describes the plan of the experiment and carried out a number of field experiments to determine the effect of the length ld and the depth K damage on the strength F of the hose material, that is, obtaining the dependence F=f (ld, K). A mathematical method of experiment planning was used and a plan was drawn up for a complete multivariate experiment of type 2k with an acceptable model accuracy of 5 %. The limits of variation of the factors are set taking into account a priori information, experimental capabilities and on the basis of the results of preliminary search experiments. The dependence in the coded and natural values of the factors is obtained. The reliability of the relationship was checked using the Fisher test, the calculated value of which was 5.98, which confirms the adequacy of the described process with a probability of 95 %. Analyzing experimental studies of the dependence of the change in the strength of the hose material on the length and depth of damage, it can be said that the change in the strength of the hose almost linearly depends on the specified damage parameters. It is found that with increasing damage, the strength of the hose material significantly decreases. When varying the length factor and the greatest depth of damage, K=0.4 mm, the strength of the hose material decreases from 11.67 kN to 8.77 kN, and in percentage terms by 25 %. The results obtained can be used in practical units of emergency rescue teams, when diagnosing hidden damage in pressure head fire hoses in order to prevent their failure in case of fires

scholarly journals Design and Applications of Multi-Frequency Holographic Subsurface Radar: Review and Case Histories

2021 ◽  
Vol 13 (17) ◽  
pp. 3487
Author(s):  
Sergey I. Ivashov ◽  
Lorenzo Capineri ◽  
Timothy D. Bechtel ◽  
Vladimir V. Razevig ◽  
Masaharu Inagaki ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Field Experiments ◽  
Continuous Wave ◽  
Subsurface Imaging ◽  
Security Screening ◽  
Shallow Subsurface ◽  
High Attenuation ◽  
Sensing Applications ◽  
History Of ◽  
Ground Penetrating

Holographic subsurface radar (HSR) is not currently in widespread usage. This is due to a historical perspective in the ground-penetrating radar (GPR) community that the high attenuation of electromagnetic waves in most media of interest and the inability to apply time-varying gain to the continuous-wave (CW) HSR signal preclude sufficient effective penetration depth. While it is true that the fundamental physics of HSR, with its use of a CW signal, does not allow amplification of later (i.e., deeper) arrivals in lossy media (as is possible with impulse subsurface radar (ISR)), HSR has distinct advantages. The most important of these is the ability to do shallow subsurface imaging with a resolution that is not possible with ISR. In addition, the design of an HSR system is simpler than for ISR due to the relatively low-tech transmitting and receiving antennae. This paper provides a review of the main principles of HSR through an optical analogy and describes possible algorithms for radar hologram reconstruction. We also present a review of the history of development of systems and applications of the RASCAN type, which is possibly the only commercially available holographic subsurface radar. Among the subsurface imaging and remote sensing applications considered are humanitarian demining, construction inspection, nondestructive testing of dielectric aerospace materials, surveys of historic architecture and artworks, paleontology, and security screening. Each application is illustrated with relevant data acquired in laboratory and/or field experiments.

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