The effect of cover crops on soil structure is mainly driven by root architecture

2021 ◽  
Author(s):  
Maik Lucas ◽  
Linh Nguyen ◽  
Andrey Guber ◽  
Alexandra Kravchenko
Keyword(s):  
Root System ◽  
Cover Crops ◽  
Soil Structure ◽  
Image Features ◽  
Small Scale ◽  
Pore Characteristics ◽  
Pore Connectivity ◽  
Imaging Protocol ◽  
X Ray ◽  
Wide Range

<p>Cover crops are known to increase macroporosity and pore connectivity, thus having a beneficial effect on soil hydraulic properties such as saturated hydraulic conductivity, However, cover crop species typically used encompass a variety of contrasting root architectures and their effects on small-scale pore properties are difficult to quantify.</p><p>Here we explore the influence of five different cover crops (annual ryegrass, Austrian winter pea, dwarf essex rapeseed, oats, and oilseed radish) on soil structure with X-ray µCT. Undisturbed samples were taken from an experiment with these cover crops on Kellogg Biological Station (Michigan, USA) in October 2019. Two soil columns with a diameter of 5 cm were taken in 5 - 10 cm depth from each of three replicated plots per plant species and scanned with X-ray µCT at a resolution of 18 µm.</p><p>These images will be used to characterize pore structure in terms of pore size distribution, pore connectivity. In addition, a new imaging protocol will be used, which combines existing ones with a random forest classifier to segment image features such as pores, biopores and roots simultaneously.</p><p>First, the results reveal that different cover crops indeed result in different pore characteristics.  The fibrous root system of oats leads to the highest volume of narrow macropores and increased their connectivity, while the tap root system of dwarf essex rapeseed mainly effected wide macropores.  The highly diverse root system of Australian winter pea increased a wide range of pore sizes and thus resulted in the highest visible porosity.</p><p>The current study is funded by a grant from USDA Organic Transition program</p>

scholarly journals Measurement of three-dimensional displacement field in piled embankments using synchrotron X-ray tomography

2019 ◽  
Vol 56 (6) ◽  
pp. 885-892 ◽  
Author(s):  
Louis King ◽  
Abdelmalek Bouazza ◽  
Anton Maksimenko ◽  
Will P. Gates ◽  
Stephen Dubsky
Keyword(s):  
High Resolution ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Physical Models ◽  
Scale Model ◽  
Small Scale ◽  
Full Field ◽  
X Ray ◽  
Wide Range ◽  
Piled Embankments

The measurement of displacement fields by nondestructive imaging techniques opens up the potential to study the pre-failure mechanisms of a wide range of geotechnical problems within physical models. With the advancement of imaging technologies, it has become possible to achieve high-resolution three-dimensional computed tomography volumes of relatively large samples, which may have previously resulted in excessively long scan times or significant imaging artefacts. Imaging of small-scale model piled embankments (142 mm diameter) comprising sand was undertaken using the imaging and medical beamline at the Australian Synchrotron. The monochromatic X-ray beam produced high-resolution reconstructed volumes with a fine texture due to the size and mineralogy of the sand grains as well as the phase contrast enhancement achieved by the monochromatic X-ray beam. The reconstructed volumes were well suited to the application of digital volume correlation, which utilizes cross-correlation techniques to estimate three-dimensional full-field displacement vectors. The output provides insight into the strain localizations that develop within piled embankments and an example of how advanced imaging techniques can be utilized to study the kinematics of physical models.

The measurement of nitrous oxide emissions from soil by using chambers

1995 ◽  
Vol 351 (1696) ◽  
pp. 327-338 ◽  
Keyword(s):  
Nitrous Oxide ◽  
Soil Structure ◽  
Gas Analysis ◽  
Nitrous Oxide Emissions ◽  
Infrared Spectrometry ◽  
Small Scale ◽  
Emission Rates ◽  
Wide Range ◽  
Flux Measurements ◽  
Closed Chambers

Small flux chambers are widely used to measure emissions of nitrous oxide, N 2 O , from soil, the gas being determined by gas chromatography with an electron capture detector. The technique is relatively cheap, and is adaptable to a wide range of site conditions and emission rates: from the order of 1 µg m -2 h -1 to more than 10 mg m -2 h -1 . Increasingly, systems are being automated, to get more information on short-term temporal variability and to collect data over long periods to improve estimates of total annual emissions. Such systems are being used in the field and with soil monoliths installed in a greenhouse. Large chambers 50-60 m 2 in area, with gas analysis by long-path infrared spectrometry, offer a way of overcoming small-scale spatial variability, and are useful in conditions where micrometeorological methods may not be applicable, or when long runs of data are needed from the same site. In studies with small closed chambers, we have measured N 2 0 emissions from grassland ranging from negligible values to about 4 mg N 2 O -N m -2 h -1 (nearly 1 kg N 2 O-N ha -1 d -1 ), with total losses in the range 0.14-5.1% of the nitrogen applied as fertilizer, depending on factors such as soil structure, water potential and temperature, and the chemical form of the fertilizer. Reasonable agreement can be obtained between chamber and micrometeorological flux measurements on homogeneous sites.

Nano Sized ZnO/MnO2/Gd2O3 Ternary Heterostructures for Enhanced Photocatalysis

2020 ◽  
Vol 5 (1) ◽  
pp. 36-46 ◽  
Author(s):  
Shubha Pranesh ◽  
Jayalakshmi Nagaraju
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Visible Light ◽  
Effluent Treatment ◽  
Small Scale ◽  
Blue Dye ◽  
Aquatic Life ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Wide Range

Background: The cost of effluent treatment is not affordable by small scale industries especially in developing countries. Hence the effluent is discharged without treatment into water bodies. The dyes do not degrade easily and possess a major concern to be addressed. The aquatic life is highly affected and also leads to bio magnification of the chemicals through the food chain. Objective: To synthesize a ternary hybrid structure for enhanced photocatalytic activity under visible light. It is intended to reduce toxicity caused by dyeing units. Methods: Synthesized nanomaterials are characterized and used as photocatlyst for the degradation of methylene blue. In degradation experiment known weight of catalyst was added to known volume of an aqueous solution of dye at various concentrations. The solutions are aerated in dark for about 30 min. At the time of irradiation of light, known aliquot of the aqueous mixture was collected at an interval of constant time each from the reaction solution. The catalyst in the mixture was separated by centrifuging the mixture and absorbance was measured. The % of degradation of the dye can be determined knowing initial and final dye concentration. Result: Heterostructures are characterized with analytical tools such as X-ray diffraction, Fourier transform infrared spectroscopy. Band gap of photocatlyst is calculated by application of UV-Vis spectroscopy. Morphology is seen using scanning electron microscopy and transmission electron microscopy. Distribution of constituent structures is observed with energy-dispersive X-ray (EDX) spectroscopy. The structures are used for photocatalytic degradation of methylene blue dye solution under UV and visible light irradiation. Heterostructures showed best performance under visible light. Conclusion: The ternary hybrid nanostructure ZnO-MnO2-Gd2O3 was effectively prepared by a simple solution combustion method. The ternary compound shows wide range of absorption by expanding absorption band both in UV and visible regions. Structures showed better catalytic property under visible light.

scholarly journals Chrysopogon zizanioides (vetiver).

2020 ◽  
Author(s):  
Julissa Rojas-Sandoval
Keyword(s):  
Root System ◽  
Water Conservation ◽  
Native Species ◽  
Soil Structure ◽  
The Philippines ◽  
Climatic Conditions ◽  
Wild Type ◽  
Dissolved Nutrients ◽  
Chrysopogon Zizanioides ◽  
Wide Range

Abstract Chrysopogon zizanioides is a grass native to Asia, now widely introduced and cultivated in tropical and subtropical regions of the world. There are two types, an infertile domesticated type and a fertile wild type. C. zizanioides can grow in a wide range of soils and climatic conditions and is very tolerant of disturbance including grazing, fire, floods and drought. This is in part due to its dense root system that can reach depths of over 3 m. All these features have made this species an excellent option for soil and water conservation (among other uses), but also make the fertile wild type of this plant a problematic invasive species. Once established, it grows very densely and has the potential to displace other plant species including other grasses. Currently, vetiver is listed as invasive in China, Fiji, Costa Rica, Anguilla and the Philippines. This species is highly efficient in absorbing dissolved nutrients such as nitrogen and phosphorous, and its dense root system can directly alter the soil structure and modify or inhibit nutrient and water acquisition by native species. Due to its deep root system, it is difficult to remove manually. It can be controlled by dense shade and by digging up the crown, and it is susceptible to glyphosate.

scholarly journals Semiautomated 3D Root Segmentation and Evaluation Based on X-Ray CT Imagery

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Stefan Gerth ◽  
Joelle Claußen ◽  
Anja Eggert ◽  
Norbert Wörlein ◽  
Michael Waininger ◽  
...  
Keyword(s):  
Root System ◽  
Large Scale ◽  
Plant Phenotyping ◽  
Manual Segmentation ◽  
Volume Data ◽  
Storage Roots ◽  
Root Volume ◽  
Time Resolved ◽  
X Ray ◽  
Wide Range

Background. Computed X-ray tomography (CTX) is a high-end nondestructive approach for the visual assessment of root architecture in soil. Nevertheless, in order to evaluate high-resolution CTX data of root architectures, manual segmentation of the depicted root systems from large-scale volume data is currently necessary, which is both time consuming and error prone. The duration of such a segmentation is of importance, especially for time-resolved growth analysis, where several instances of a plant need to be segmented and evaluated. Specifically, in our application, the contrast between soil and root data varies due to different growth stages and watering situations at the time of scanning. Additionally, the root system itself is expanding in length and in the diameter of individual roots. Objective. For semiautomated and robust root system segmentation from CTX data, we propose the RootForce approach, which is an extension of Frangi’s “multi-scale vesselness” method and integrates a 3D local variance. It allows a precise delineation of roots with diameters down to several μm in pots with varying diameters. Additionally, RootForce is not limited to the segmentation of small below-ground organs, but is also able to handle storage roots with a diameter larger than 40 voxels. Results. Using CTX volume data of full-grown bean plants as well as time-resolved (3D+time) growth studies of cassava plants, RootForce produces similar (and much faster) results compared to manual segmentation of the regarded root architectures. Furthermore, RootForce enables the user to obtain traits not possible to be calculated before, such as total root volume (Vroot), total root length (Lroot), root volume over depth, root growth angles (θmin, θmean, and θmax), root surrounding soil density Dsoil, or form fraction F. Discussion. The proposed RootForce tool can provide a higher efficiency for the semiautomatic high-throughput assessment of the root architectures of different types of plants from large-scale CTX. Furthermore, for all datasets within a growth experiment, only a single set of parameters is needed. Thus, the proposed tool can be used for a wide range of growth experiments in the field of plant phenotyping.

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.

Integrated Design and Multi-Objective Optimization of a Single Stage Heat-Pump Turbocompressor

2013 ◽  
Author(s):  
J. Schiffmann
Keyword(s):  
Design Optimization ◽  
High Efficiency ◽  
Integrated Design ◽  
Heat Pumps ◽  
Small Scale ◽  
Multi Objective Optimization ◽  
Design Constraints ◽  
Multi Objective ◽  
Wide Range ◽  
Standard Design

Small scale turbomachines in domestic heat pumps reach high efficiency and provide oil-free solutions which improve heat-exchanger performance and offer major advantages in the design of advanced thermodynamic cycles. An appropriate turbocompressor for domestic air based heat pumps requires the ability to operate on a wide range of inlet pressure, pressure ratios and mass flows, confronting the designer with the necessity to compromise between range and efficiency. Further the design of small-scale direct driven turbomachines is a complex and interdisciplinary task. Textbook design procedures propose to split such systems into subcomponents and to design and optimize each element individually. This common procedure, however, tends to neglect the interactions between the different components leading to suboptimal solutions. The authors propose an approach based on the integrated philosophy for designing and optimizing gas bearing supported, direct driven turbocompressors for applications with challenging requirements with regards to operation range and efficiency. Using previously validated reduced order models for the different components an integrated model of the compressor is implemented and the optimum system found via multi-objective optimization. It is shown that compared to standard design procedure the integrated approach yields an increase of the seasonal compressor efficiency of more than 12 points. Further a design optimization based sensitivity analysis allows to investigate the influence of design constraints determined prior to optimization such as impeller surface roughness, rotor material and impeller force. A relaxation of these constrains yields additional room for improvement. Reduced impeller force improves efficiency due to a smaller thrust bearing mainly, whereas a lighter rotor material improves rotordynamic performance. A hydraulically smoother impeller surface improves the overall efficiency considerably by reducing aerodynamic losses. A combination of the relaxation of the 3 design constraints yields an additional improvement of 6 points compared to the original optimization process. The integrated design and optimization procedure implemented in the case of a complex design problem thus clearly shows its advantages compared to traditional design methods by allowing a truly exhaustive search for optimum solutions throughout the complete design space. It can be used for both design optimization and for design analysis.

scholarly journals Silicon Effects on the Root System of Diverse Crop Species Using Root Phenotyping Technology

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 885
Author(s):  
Pooja Tripathi ◽  
Sangita Subedi ◽  
Abdul Latif Khan ◽  
Yong-Suk Chung ◽  
Yoonha Kim
Keyword(s):  
Root System ◽  
Root Morphology ◽  
Morphological Traits ◽  
Crop Production ◽  
Spatial Configuration ◽  
Global Climate ◽  
Learning Technologies ◽  
Climate Change Scenarios ◽  
Crop Species ◽  
Wide Range

Roots play an essential function in the plant life cycle, as they utilize water and essential nutrients to promote growth and plant productivity. In particular, root morphology characteristics (such as length, diameter, hairs, and lateral growth) and the architecture of the root system (spatial configuration in soil, shape, and structure) are the key elements that ensure growth and a fine-tuned response to stressful conditions. Silicon (Si) is a ubiquitous element in soil, and it can affect a wide range of physiological processes occurring in the rhizosphere of various crop species. Studies have shown that Si significantly and positively enhances root morphological traits, including root length in rice, soybean, barley, sorghum, mustard, alfalfa, ginseng, and wheat. The analysis of these morphological traits using conventional methods is particularly challenging. Currently, image analysis methods based on advanced machine learning technologies allowed researchers to screen numerous samples at the same time considering multiple features, and to investigate root functions after the application of Si. These methods include root scanning, endoscopy, two-dimensional, and three-dimensional imaging, which can measure Si uptake, translocation and root morphological traits. Small variations in root morphology and architecture can reveal different positive impacts of Si on the root system of crops, with or without exposure to stressful environmental conditions. This review comprehensively illustrates the influences of Si on root morphology and root architecture in various crop species. Furthermore, it includes recommendations in regard to advanced methods and strategies to be employed to maintain sustainable plant growth rates and crop production in the currently predicted global climate change scenarios.

scholarly journals A Lightweight Fusion Distillation Network for Image Deblurring and Deraining

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5312
Author(s):  
Yanni Zhang ◽  
Yiming Liu ◽  
Qiang Li ◽  
Jianzhong Wang ◽  
Miao Qi ◽  
...  
Keyword(s):  
Deep Learning ◽  
Image Deblurring ◽  
Image Features ◽  
Image Feature ◽  
Model Complexity ◽  
Small Scale ◽  
Feature Maps ◽  
Learning Framework ◽  
Channel Information ◽  
Scale Spaces

Recently, deep learning-based image deblurring and deraining have been well developed. However, most of these methods fail to distill the useful features. What is more, exploiting the detailed image features in a deep learning framework always requires a mass of parameters, which inevitably makes the network suffer from a high computational burden. We propose a lightweight fusion distillation network (LFDN) for image deblurring and deraining to solve the above problems. The proposed LFDN is designed as an encoder–decoder architecture. In the encoding stage, the image feature is reduced to various small-scale spaces for multi-scale information extraction and fusion without much information loss. Then, a feature distillation normalization block is designed at the beginning of the decoding stage, which enables the network to distill and screen valuable channel information of feature maps continuously. Besides, an information fusion strategy between distillation modules and feature channels is also carried out by the attention mechanism. By fusing different information in the proposed approach, our network can achieve state-of-the-art image deblurring and deraining results with a smaller number of parameters and outperform the existing methods in model complexity.

scholarly journals QPOs in compact binaries from small scale eruptions in an inner magnetized disk

2020 ◽  
Author(s):  
Nicolas Scepi ◽  
Mitchell C Begelman ◽  
Jason Dexter
Keyword(s):  
Rapid Heating ◽  
Small Scale ◽  
Type B ◽  
Periodic Oscillations ◽  
X Ray ◽  
Compact Binaries ◽  
Heating And Cooling ◽  
Low Mass ◽  
X Ray Binaries ◽  
Standard Disk

Abstract Dwarf novæ (DNe) and low mass X-ray binaries (LMXBs) are compact binaries showing variability on time scales from years to less than seconds. Here, we focus on explaining part of the rapid fluctuations in DNe, following the framework of recent studies on the monthly eruptions of DNe that use a hybrid disk composed of an outer standard disk and an inner magnetized disk. We show that the ionization instability, that is responsible for the monthly eruptions of DNe, is also able to operate in the inner magnetized disk. Given the low density and the fast accretion time scale of the inner magnetized disk, the ionization instability generates small, rapid heating and cooling fronts propagating back and forth in the inner disk. This leads to quasi-periodic oscillations (QPOs) with a period of the order of 1000 s. A strong prediction of our model is that these QPOs can only develop in quiescence or at the beginning/end of an outburst. We propose that these rapid fluctuations might explain a subclass of already observed QPOs in DNe as well as a, still to observe, subclass of QPOs in LMXBs. We also extrapolate to the possibility that the radiation pressure instability might be related to Type B QPOs in LMXBs.

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