Numerous ecological studies in grasslands and shrublands have used plant cover as a surrogate of aboveground net primary production (ANPP), biomass or biovolume. Regression equations between biomass ...and plant cover involve taking into account a wide range of vegetation cover. This comment assesses the consequences for biomass estimations of the method presented by Flombaum and Sala Flombaum, P., Sala, O.E., 2007. A non-destructive and rapid method to estimate biomass and aboveground net primary production in arid environments. Journal of Arid Environments 69, 352–358., which consists in removing portions of individuals to achieve the desired plant cover estimation. We found that alteration of architecture of individuals could lead to an overestimation of biomass by a factor ranging from 1.05 to 3.16, depending on the extent of the reduction of the plant cover.
In recent years, mushrooms have been attracted much attention as a healthy food, since they are rich in dietary fiber, low in calories, and contain functional constituents, such as lignin and ...β-glucan. Thus with increasing demand, the cultivation of mushrooms has become popular. However, conditions for the cultivation environment are largely dependent upon the experience of the farming site and have little scientific basis. We have been working on the development of a technique for diagnosis of ripeness at an early stage of cultivation, using an MRI device obtaining non-invasive tomographic imaging (2-D imaging) of mycelium within the cultivation medium that provides nourishment for the fruit body formation. In this study we have investigated the reconfiguration of 3D images, based on the 2D data previously obtained, in order to further observe the growth of mycelium within the medium. Thus three-dimensional observation of growing mycelium, such as the cracks formed at inoculation and the mycelial strands that grow in the surrounding area of the inoculation trace, are possible. Additional basic data, useful for development of the ripeness diagnostic technique for culture medium, have been obtained.
Abstract Objectives To quantify in vitro the root dentin moisture (DM) when soaked in 10% ascorbic acid solution (Group A) and distilled water (Group B) for up to 14 days. Methods Forty-four ...extracted human mandibular single-rooted teeth were sectioned perpendicular to the long axis at the CEJ to access the root dentin. The samples were divided into Groups A and B. Baseline (day 0) DM was measured using a digital grain moisture meter. One sample was placed in each tube, which was then filled with solution. All tubes were kept at 37 °C and 100% humidity. DM was measured after 1, 3, 7, and 14 days. The baseline DM value was used as a covariate in the generalized estimating equation (GEE) analysis to account for the difference in the baseline DM between the two groups. Results The mean DM (%) values ± standard deviation on days 0, 1, 3, 7, and 14 were 11.4 ± 1.08, 17.1 ± 0.87, 18.2 ± 0.76, 18.4 ± 0.77, and 17.9 ± 0.90 in Group A, and 10.2 ± 0.95, 12.8 ± 0.90, 13.3 ± 0.95, 13.0 ± 0.91, and 13.2 ± 0.89 in Group B, respectively. Group A had significantly higher baseline DM than Group B ( p = 0.006). After adjusting for differences in the baseline, the GEE analysis indicated that, on average, Group A had a significantly higher increase in DM than Group B, with means ± standard deviation of 4.35 ± 0.26. Conclusions The moisture increase in the ascorbic acid group was greater than that in the distilled water group. Soaking root dentin in the unreplenished ascorbic acid solution or distilled water beyond 3 days did not further increase DM.
Evaluating service lives of rubber materials at certain temperatures requires a destructive method (typically using elongation at break). In this study, a non-destructive method based on hardness ...change rate was proposed for evaluating the service life of chloroprene rubber (CR). Compared to the destructive method, this non-destructive method ensures homogeneity of CR specimens and requires a small number of samples. Thermal accelerated degradation test was conducted on the CR specimens at 55, 70, 85, 100, and 125℃, and the tensile strength, elongation at break, and hardness were measured. The results of the experiment were compared to those of the accelerated life evaluation method proposed in this study. Comparing the analyzed lives in the high temperature region (70, 85, 100, and 125℃), the difference between the service lives for the destructive method (using the elongation at break) and non-destructive method (using the hardness) was approximately 0.1 year. Therefore, it was confirmed that the proposed non-destructive evaluation method based on hardness changes can evaluate the actual life of CR under thermally accelerated degradation conditions.
O objetivo deste trabalho foi avaliar a precisão do método de fotos digitais na estimativa da área foliar de meloeiro e encontrar modelos matemáticos de estimativa da área foliar em função de medidas ...lineares da folha para diferentes estádios fenológicos. Foram fotografadas todas as folhas ímpares de 8 plantas após transplante definitivo, através de câmera fotográfica digital, resultando, durante todo o ciclo da cultura, em 4.188 fotos, das quais mediu-se a área foliar, o comprimento e a largura da folha, por meio do software Sigma Scan Pro v. 5.0, Jandel Scientific. Para verificar a precisão do método de fotos digitais, retirou-se uma amostra de 40 folhas, de onde foram obtidas a área foliar através do método padrão de discos foliares e pelo método de fotos. Foi encontrada uma correlação de 0,99 entre o método padrão (discos) e o de fotos. O método de fotos digitais pode ser utilizado para estimar a área foliar da cultura de meloeiro, e a estimativa da área foliar de meloeiro por estádio fenológico apresenta maior precisão, sendo a maior variabilidade na estimativa da área da folha observada no período reprodutivo. A largura máxima da folha de meloeiro é a medida linear que melhor estima a área foliar.This experiment was aimed at evaluating the precision of digital photos in estimating the leaf area of watermelon plants and to find mathematical models that estimates leaf area as a function of leaf linear measurements at different growth stages. All odd leaves of eight plants were photographed after being established on the field using a digital camera that resulted in 4,188 photos in which length and width were measured using a Sigma Scan Pro v. 5.0 Jandel Scientific software. In order to estimate the precision of the digital photos method, a sample consisting of 40 leaves was taken and leaf area measured using the standard leaf disks and the photo method. A 0.99 correlation coefficient was detected between the two methods. Therefore digital photos can be used to estimate leaf area of watermelon plants and estimation of leaf area per growth stage presents higher precision. The larger variability in leaf area was observed during reproductive growth. Maximum leaf width is the measure that best estimates leaf area.
Trees in the urban context provide several environmental services. The current climate change crisis is seriously compromising the health of trees in urban and periurban areas leading to an increment ...of tree collapses. As a consequence, there is high risk of damage to urban infrastructures and risk for the safety of the people. Preventing tree failure and assessing the tree stability is a current challenge to maintain the ecosystem services provided by the trees in urban context but at the same time to guarantee the well-being of the people. Several methods and instruments are used to assess the stability of trees, among them, the dynamic analyses methods monitor the behaviour of the tree considering it as an object that sways in a dynamic manner. That behaviour can be described with several dynamic properties like the fundamental sway frequencies, a key-property to understand the motion of the tree under wind loads. The purpose of this paper is to present a novel approach to measure the dynamic response of a tree. The method is based on the assessment of the sway fundamental frequency under free vibration without notable external forces, using a non-destructive method consisting of high-sensitivity accelerometers. The method used to rigidly attach the sensors without both provoking any damages to the tree and compromising the data acquisition was improved several times. Due to the thickness of the bark of one sample in the first test the method didn't correctly measure the fundamental sway frequencies and a few enhancements have been made before the other tests. In the second test each tree was tested using three accelerometers fixed on the surface of the tree through a 3D printed support, a couple of omega shape steel bars and a ratchet strap. The technique was then tested on seven different open-grown broadleaf trees. Results of the spectral analyses shows that a reliable estimation of the peak values under free vibration and without any artificial excitations can be achieved. Moreover, the experimental design of the method allows to monitor the fundamental sway frequency rapidly and without provoking damage to the bark or the sapwood of the tree.
The researchers have developed a device that utilizes different image processing techniques that include Grayscale, Gaussian blur, Binary thresholding, Morphology, Contour, and Flood fill to ...determine a crack or spall width area. The Image capturing device that the researchers created also classifies if the said crack or spall can still be tolerable or needs structural consultation based on the thresholds set. The device has a graphical user interface that captures the images of crack or spall, measuring its width and area and classification if tolerable or needs structural consultation.
The question whether the current in superconducting tapes flows homogeneously or is distributed in some way across the width, between its edges, can be answered in several ways. If we are interested ...in the critical current distribution only, the destructive method can be applied. The tape can be cut longitudinally into several sub-tapes and the critical current can be measured in each sub-tape. The principle of the method is trivial and straightforward. Other modifications of destructive method exist, e.g. gradual brushing of the tape from one side and looking for a change in the overall critical current in the rest of the tape. The disadvantage of both methods is rough mechanical interaction with the tape, which can modify its transport properties and inability to repeat measurements on the same piece of initial sample after changing some of the external parameters. The magnetic knife method is an example of a non-destructive approach. Still it is from principle limited to the critical current distribution only. Current distribution in general, without limitation to the critical one, can be achieved by measuring the self-magnetic-field of the tape and solving the inverse problem for corresponding current distribution. An improved, unique procedure of calculation is described here in detail. The results for special case of current equal to the critical current, i.e. the critical current distribution across the tape width, are compared with the results of the destructive method applied on the same tape. The possibility to check the method by making comparison is the only reason for limitation to (zero field) critical current. Any current distribution, at any phase of the tape transport current during AC cycle, can be determined by the non-destructive method. As an example, frozen currents distribution, after ramping transport current up to
I
c and afterwards down to zero current, are shown.
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