| 1 | Semiautomated 3D Root Segmentation and Evaluation Based on X-Ray CT Imagery显示文摘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 severalμm 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,andθmax),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. | Stefan Gerth Joelle Claußen Anja Eggert Norbert Wörlein Michael Waininger Thomas Wittenberg Norman Uhlmann | 2021 | Plant Phenomics2021,3,1: | 2 |
| 13 | Optical Path Length,Temperature,and Wavelength Effects Simulation on Ozone Gas Absorption Cross Sections towards Green Communications显示文摘Ozone is a green house gas. Ozone absorption cross sections have been reported with discrepancies and inconsistencies. In this paper, simultaneous effects of the optical path length and temperature variations on ozone gas absorption cross sections are investigated at different wavelengths. HITRAN 2012, the latest available line list on spectralcalc.com simulator, is used in this study to simulate ozone gas absorption cross sections in relation to the simultaneous effects of the optical path length and temperature at the wavelengths of 603 nm and 575 nm. Results obtained for gas cells with the optical path length from 10 cm to 120 cm show that the decrease in temperatures from 313 K to 103 K results in the increase in ozone gas absorption cross sections. At wavelengths of 603 nm and 575 nm, the percentage increase of ozone gas absorption cross sections is 1.22% and 0.71%, respectively. Results obtained in this study show that in the visible spectrum, at constant pressure, ozone gas absorption cross sections are dependent on the temperature and wavelength but do not depend on the optical path length. Analysis in this work addresses discrepancies in ozone gas absorption cross sections in relation to the temperature in the visible spectrum; thus, the results can be applied to get optimal configuration of high accuracy ozone gas sensors. | Michael David mohd haniff ibrahim Sevia Mahdaliza Idrus Nor Hafizah Ngajikin Asrul Izam Azmi Tay Ching En Marcus | 2016 | Journal of Electronic Science and Technology2016,14,3: | 0 |