scholarly journals Sound Wave Energy Resulting from the Impact of Water Drops on the Soil Surface

PLoS ONE ◽  
2016 ◽  
Vol 11 (7) ◽  
pp. e0158472 ◽  
Author(s):  
Magdalena Ryżak ◽  
Andrzej Bieganowski ◽  
Tomasz Korbiel
2020 ◽  
Author(s):  
Michał Beczek ◽  
Magdalena Ryżak ◽  
Rafał Mazur ◽  
Agata Sochan ◽  
Cezary Polakowski ◽  
...  

<p>Soil, i.e. the natural outer layer of the lithosphere and an important component of many ecosystems, may be subjected to various degradation processes dependent on different factors. One of the forms of degradation is water erosion, where the first stage is the splash phenomenon. This process is caused by water drops hitting the soil surface during rainfall, which results in detachment and ejection of splashed material and transport thereof over different distances. The aim of this study was to present the application of the high-speed camera technique for investigations of surface phenomena (effects) influenced by the impact of a single water-drop onto the soil surface.</p><p>The measurements were conducted on types of soil differentiated in terms of texture and variants of initial moisture content, which helped to observe different aspects of the soil splash phenomenon. Water drops with a diameter of 4.2 mm fell on soil samples with various kinetic energy values depending on the height of the drop fall (up to 7m). Phantom Miro M310 high-speed cameras were used to observe the effects of the drop impact. The devices registered images with a speed of 3260 fps (frames per second) at the highest available resolution (1280x800 pixels). The following phenomena were observed: I) ejection of splashed particles (including solid soil particles, water droplets, solid particles within the water sheath); II) crown formation – when the drop impacting onto wet soil surface forces the liquid layer to rise up and form a crown (important for the mode and amount of transferred material); III) micro-crater formation – the deformation of the surface and formation of a shallow pool after the drop impact.          </p><p> </p><p>This work was partly financed from the National Science Centre, Poland; project no. 2018/31/N/ST10/01757.</p><p> </p><p>References:</p><ol><li>Beczek M., Ryżak M., Sochan A., Mazur R., Bieganowski A.: The mass ratio of splashed particles during raindrop splash phenomenon on soil surface. GEODERMA 347, 40-48, 2019</li> <li>Beczek M., Ryżak M., Lamorski K., Sochan A., Mazur R., Bieganowski A.: Application of X-ray computed microtomography to soil craters formed by raindrop splash. Geomorphology 303, 357-361, 2018</li> <li>Beczek M., Ryżak M., Sochan A., Mazur R., Polakowski C., Bieganowski A.: The differences in crown formation during the splash on the thin water layers formed on the saturated soil surface and model surface. PLoS ONE 12, 2017</li> </ol>


Author(s):  
N. Maidanovych ◽  

The purpose of this work is to review and analyze the main results of modern research on the impact of climate change on the agro-sphere of Ukraine. Results. Analysis of research has shown that the effects of climate change on the agro-sphere are already being felt today and will continue in the future. The observed climate changes in recent decades have already significantly affected the shift in the northern direction of all agro-climatic zones of Europe, including Ukraine. From the point of view of productivity of the agro-sphere of Ukraine, climate change will have both positive and negative consequences. The positives include: improving the conditions of formation and reducing the harvesting time of crop yields; the possibility of effective introduction of late varieties (hybrids), which require more thermal resources; improving the conditions for overwintering crops; increase the efficiency of fertilizer application. Model estimates of the impact of climate change on wheat yields in Ukraine mainly indicate the positive effects of global warming on yields in the medium term, but with an increase in the average annual temperature by 2 ° C above normal, grain yields are expected to decrease. The negative consequences of the impact of climate change on the agrosphere include: increased drought during the growing season; acceleration of humus decomposition in soils; deterioration of soil moisture in the southern regions; deterioration of grain quality and failure to ensure full vernalization of grain; increase in the number of pests, the spread of pathogens of plants and weeds due to favorable conditions for their overwintering; increase in wind and water erosion of the soil caused by an increase in droughts and extreme rainfall; increasing risks of freezing of winter crops due to lack of stable snow cover. Conclusions. Resource-saving agricultural technologies are of particular importance in the context of climate change. They include technologies such as no-till, strip-till, ridge-till, which make it possible to partially store and accumulate mulch on the soil surface, reduce the speed of the surface layer of air and contribute to better preservation of moisture accumulated during the autumn-winter period. And in determining the most effective ways and mechanisms to reduce weather risks for Ukrainian farmers, it is necessary to take into account the world practice of climate-smart technologies.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2015
Author(s):  
Iwona Jaskulska ◽  
Kestutis Romaneckas ◽  
Dariusz Jaskulski ◽  
Piotr Wojewódzki

Conservation agriculture has three main pillars, i.e., minimum tillage, permanent soil cover, and crop rotation. Covering the soil surface with plant residues and minimum mechanical soil disturbance can all result from introducing a strip-till one-pass (ST-OP) system. The aim of this study was to determine the impact of the ST-OP technology on the management of plant residues, soil properties, inputs, and emissions related to crop cultivation. We compared the effect of a ST-OP system against conventional tillage (CT) using a plough, and against reduced, non-ploughing tillage (RT). Four field experiments were conducted for evaluating the covering of soil with plant residues of the previous crop, soil loss on a slope exposed to surface soil runoff, soil structure and aggregate stability, occurrence of soil organisms and glomalin content, soil moisture and soil water reserve during plant sowing, labour and fuel inputs, and CO2 emissions. After sowing plants using ST-OP, 62.7–82.0% of plant residues remained on the soil surface, depending on the previous crop and row spacing. As compared with CT, the ST-OP system increased the stability of soil aggregates of 0.25–2.0 mm diameter by 12.7%, glomalin content by 0.08 g·kg−1, weight of earthworms five-fold, bacteria and fungi counts, and moisture content in the soil; meanwhile, it decreased soil loss by 2.57–6.36 t·ha−1 year−1, labour input by 114–152 min·ha−1, fuel consumption by 35.9–45.8 l·ha−1, and CO2 emissions by 98.7–125.9 kg·ha−1. Significant favourable changes, as compared with reduced tillage (RT), were also found with respect to the stability index of aggregates of 2.0–10.0 mm diameter, the number and weight of earthworms, as well as bacteria and fungi counts.


2011 ◽  
Vol 2 ◽  
pp. 152-161 ◽  
Author(s):  
Hans J Ensikat ◽  
Petra Ditsche-Kuru ◽  
Christoph Neinhuis ◽  
Wilhelm Barthlott

Lotus leaves have become an icon for superhydrophobicity and self-cleaning surfaces, and have led to the concept of the ‘Lotus effect’. Although many other plants have superhydrophobic surfaces with almost similar contact angles, the lotus shows better stability and perfection of its water repellency. Here, we compare the relevant properties such as the micro- and nano-structure, the chemical composition of the waxes and the mechanical properties of lotus with its competitors. It soon becomes obvious that the upper epidermis of the lotus leaf has developed some unrivaled optimizations. The extraordinary shape and the density of the papillae are the basis for the extremely reduced contact area between surface and water drops. The exceptional dense layer of very small epicuticular wax tubules is a result of their unique chemical composition. The mechanical robustness of the papillae and the wax tubules reduce damage and are the basis for the perfection and durability of the water repellency. A reason for the optimization, particularly of the upper side of the lotus leaf, can be deduced from the fact that the stomata are located in the upper epidermis. Here, the impact of rain and contamination is higher than on the lower epidermis. The lotus plant has successfully developed an excellent protection for this delicate epistomatic surface of its leaves.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 920
Author(s):  
Yue Hong ◽  
Irina Temiz ◽  
Jianfei Pan ◽  
Mikael Eriksson ◽  
Cecilia Boström

Wave energy converters (WECs), which are designed to harvest ocean wave energy, have recently been improved by the installation of numerous conversion mechanisms; however, it is still difficult to find an appropriate method that can compromise between strong environmental impact and robust performance by transforming irregular wave energy into stable electrical power. To solve this problem, an investigation into the impact of varied wave conditions on the dynamics of WECs and to determine an optimal factor for WECs to comply with long-term impacts was performed. In this work, we researched the performance of WECs influenced by wave climates. We used a permanent magnet linear generator (PMLG)-based WEC that was invented at Uppsala University. The damping effect was first studied with a PMLG-type WEC. Then, a group of sea states was selected to investigate their impact on the power production of the WEC. Two research sites were chosen to investigate the WEC’s annual energy production as well as a study on the optimal damping coefficient impact. In addition, we compared the WEC’s energy production between optimal damping and constant damping under a full range of sea states at both sites. Our results show that there is an optimal damping coefficient that can achieve the WEC’s maximum power output. For the chosen research sites, only a few optimal damping coefficients were able to contribute over 90% of the WEC’s annual energy production. In light of the comparison between optimal and constant damping, we conclude that, for specific regions, constant damping might be a better choice for WECs to optimize long-term energy production.


2018 ◽  
pp. 23-40 ◽  
Author(s):  
G. V. Vindeker ◽  
E. Yu. Prudnikova ◽  
I. Yu. Savin

During the model experiment we exposed samples from surface layer of leached chernozem, grey forest and soddy-podzolic soils to study the impact of raindrop action on their surface. According to our results, surface of leached chernozem and grey forest soil transformed similarly forming the crust separated by the cracks. The crust consisted of light (washed silt fraction) and dark (compacted fine material) areas. As for the soddy-podzilic soil, we observed surface accumulation of sand and washed mineral grains. Surface image classification showed that cracks generally tended to increase in area during the surface drying. However, leached chernozem cracked quicker and heavier compared to grey forest soil. In addition, the proportion between light and dark areas of the crust for these two types of soil changed differently as well. In conditions of different transformation cycles divided by heavy rainfalls, the changes of cracks position and the increase of light crust area was observed, while dark area moved to the cracks. Such spatial rearrangement resulted in the increase of average reflectance in RGB channels. The inequality between reflectance in different channels increased as well. During the experiment significant surface lightening occurred. It mainly affected the light area of crust and led to significant rise in reflectance in red channel.


2020 ◽  
Vol 3 (2) ◽  
pp. 73-82
Author(s):  
Benjamin Schubert ◽  
William S. P. Robertson ◽  
Benjamin S. Cazzolato

The dynamic response of a submerged CETO shaped quasi-point absorbing wave energy converter coupled to a bistable power take off is presented in this study. Whilst the impact of bistability has been shown in a limited number of situations to improve the amount of power generated, many models have been restricted to a single degree of freedom and often ignore drag effects. To overcome these model limitations, a submerged single tether point absorber with a bistable power take off was modelled using both 1 and 3 degrees of freedom. The device was subjected to regular waves and included a simple model of viscous drag. The bistable mechanism was provided by a magnetic dipole model quantified by a dimensionless parameter applicable to any bistable system. The performance of the device was is assessed by the theoretical power generated. Over each model, the previously observed benefit of bistability was not consistently obtained. Simulations of regular waves demonstrated an increase in generated power for suboptimal conditions for some frequencies, while a reduction in generated power was observed in optimal conditions. The performance increase showed strong correlation to the phase relationship between the motion and exciting forces as a result of bistability.


Author(s):  
Frances M. Judge ◽  
Eoin Lyden ◽  
Michael O'Shea ◽  
Brian Flannery ◽  
Jimmy Murphy

Abstract This research presents a methodology for carrying out uncertainty analysis on measurements made during wave basin testing of an oscillating water column wave energy converter. Values are determined for Type A and Type B uncertainty for each parameter of interest, and uncertainty is propagated using the Monte Carlo method to obtain an overall Expanded Uncertainty with a 95% confidence level associated with the Capture Width Ratio of the device. An analysis into the impact of reflections on the experimental results reveals the importance of identifying the incident and combined wave field at each measurement location used to determine device performance, in order to avoid misleading results.


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