Invertebrate abundance on Potamogeton nodosus: effects of plant surface area and condition

1992 ◽  
Vol 70 (2) ◽  
pp. 300-306 ◽  
Author(s):  
David C. Beckett ◽  
Thomas P. Aartila ◽  
Andrew C. Miller

Using the macrophyte Potamogeton nodosus, we investigated variability in abundance of plant-dwelling invertebrates among individual plants. Plants were collected from three Potamogeton beds in Eau Galle Lake, Wisconsin, in June and August 1987. Invertebrate abundance on P. nodosus and the amount of plant surface area were positively correlated in both June and August. In August the amount of leaf damage (plant condition) was another important predictor of invertebrate abundance. Plant surface area and plant condition were responsible for most to almost all of the variability in invertebrate abundance on P. nodosus (R2 = 0.66 in June; R2 = 0.83 in August). The correlation between invertebrate abundance and plant condition in August and the lack of such a correlation in June indicated that plant age, rather than plant condition per se, was a causal mechanism for increased invertebrate abundance. Some plants were heavily colonized by invertebrates; a single plant collected in June held a total of 555 invertebrates, which included 177 chironomid larvae and 143 naidid worms. We estimate that the P. nodosus in a 20 × 60 m Potamogeton bed supported about 33 million invertebrates in June and approximately 30 million invertebrates in August. The use of lake management techniques in which plants are eliminated would therefore markedly reduce invertebrate abundance in the littoral zone, and would, in turn, deny fishes and waterfowl an important and abundant food resource.


2005 ◽  
Vol 486-487 ◽  
pp. 41-44 ◽  
Author(s):  
Hiroshi Taoda

Dioxins are extremely toxic, and it is difficult to treat them with the conventional method. When irradiated by light, photocatalysts generate strong oxidative potential and decomposes almost all organic substances containing dioxins to water, carbon dioxide and others. Silica-gel has high adsorptive activity as well as large surface area, and it is transparent to ultraviolet light. Photocatalytic silica-gel was prepared by a dip coating method using TiO2 sol obtained by hydrolyzing titanium tetraisopropoxide on silica-gel bead (about 3mm in diameter) and heat-treated at 550°C. Since the surface area of the photocatalytic silica-gel is 300m2/g, the reaction area is large and allows the highly efficient decomposition of harmful organic substances, unpleasant odors and colored matters contained in waste water. The photocatalytic apparatus for decomposition of dioxins in emission gas from waste incinerators is composed of the catalyst layer consisting of 95dm3 photocatalytic silica-gel and 16 units of UV lamp. The photocatalytic apparatus was connected to the bypass line led from the outlet duct of cyclone, and the concentration of dioxins in the exhaust gas was measured. Decomposition test of dioxins in scrubber water was also performed using a photocatalytic apparatus with 150g photocatalytic silica-gel and 8 units of UV lamp. After 0.5dm3 of scrubber water containing dioxins was circulated in the photocatalytic apparatus for 1, 2 and 24 hour, each concentration of dioxins in the water was measured. As a result, the removal efficiency over 99% of dioxins in emission gas and scrubber water from waste incinerators has been obtained.



Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
William T. Salter ◽  
Arjina Shrestha ◽  
Margaret M. Barbour

Abstract Background Being able to accurately assess the 3D architecture of plant canopies can allow us to better estimate plant productivity and improve our understanding of underlying plant processes. This is especially true if we can monitor these traits across plant development. Photogrammetry techniques, such as structure from motion, have been shown to provide accurate 3D reconstructions of monocot crop species such as wheat and rice, yet there has been little success reconstructing crop species with smaller leaves and more complex branching architectures, such as chickpea. Results In this work, we developed a low-cost 3D scanner and used an open-source data processing pipeline to assess the 3D structure of individual chickpea plants. The imaging system we developed consists of a user programmable turntable and three cameras that automatically captures 120 images of each plant and offloads these to a computer for processing. The capture process takes 5–10 min for each plant and the majority of the reconstruction process on a Windows PC is automated. Plant height and total plant surface area were validated against “ground truth” measurements, producing R2 > 0.99 and a mean absolute percentage error < 10%. We demonstrate the ability to assess several important architectural traits, including canopy volume and projected area, and estimate relative growth rate in commercial chickpea cultivars and lines from local and international breeding collections. Detailed analysis of individual reconstructions also allowed us to investigate partitioning of plant surface area, and by proxy plant biomass. Conclusions Our results show that it is possible to use low-cost photogrammetry techniques to accurately reconstruct individual chickpea plants, a crop with a complex architecture consisting of many small leaves and a highly branching structure. We hope that our use of open-source software and low-cost hardware will encourage others to use this promising technique for more architecturally complex species.



2018 ◽  
Vol 23 (3) ◽  
pp. 405 ◽  
Author(s):  
Saeid Javadi Khederi ◽  
Mohammad Khanjani ◽  
Mansur Gholami ◽  
Enrico De Lillo

The erineum strain of Colomerus vitis (GEM) is the most destructive pest of vineyards in western Iran and sometimes causes considerable damages to the grapevine. Little information is available on the susceptibility of the grapevine to this pest and its knowledge can be useful for a sustainable management of GEM. The present study was aimed at evaluating the responses of the plants to the infestation of GEM in order to compare the resistance/susceptibility of some native cultivars to this pest. Also, the profiling of JA, SA and IAA in leaves of infested plants of Sezdang was studied. The experiment was carried out on eighteen native cultivars and the non-native Muscat Gordo which were selected amongst the most common in southern and western Iran. Potted plants were cultivated under greenhouse conditions at a temperature of 32 ± 3.8°C, 75 ± 5% R.H. and a photoperiod of L16: D8 h. The impact of GEM was evaluated on the basis of the leaf area and weight, number and size of the erinea, and percentage of leaves with erinea three months after the infestation. The cane length was measured, too. Mite density on galled leaves (three months after the infestation) and in buds (at the bud breaking) was assessed.        Cluster analysis based on the leaf damage index induced by GEM allowed to distinguish highly affected (Sezdang, Khalili, Ghalati and Rishbaba), moderately affected (Neyshaboori, Gazne, Muscat, Lale, Shahani Sefid, Ahmad, Monagha and Sia) and scarcely affected (Yaghuti, Rotabi, White Thompson, Atabaki, Koladari and Sahebi and Shahani Gerd) cultivars. The mite density into the buds and on the galled leaves was higher in the medium-late (Rishbaba and Khalili) and late ripening (Sezdang and Ghalati) cultivars rather than in the early (Sahebi and Shahani Gerd) and early-medium (Atabaki) ripening ones. The leaf damaged area, the leaf weight, the shoot length and the erineum development were correlated to the mite density and were the highest on Sezdang, Khalili, Ghalati and Rishbaba and the lowest on Atabaki, Koladari, Sahebi and Shahani Gerd. The highest density of the overwintering population was detected in proximal buds of all treated cultivars.        The plant responses and the mite density were investigated also in the second and third year after the first mite infestation on highly affected (Sezdang, Khalili, Ghalati, Rishbaba), a few of the moderately affected (Neyshaboori, Gazne, Muscat) and the scarcely affected cultivars (White Thompson, Atabaki, Koladari, Sahebi, Shahani Gerd). The leaf damaged area, the percentage of galled leaves, the percentage of cane length reduction and the mite density strongly decreased during all three years of observations on the highly affected Sezdang, Khalili and Gazne. On the contrary, Ghalati and Rishbaba displayed an increase of the leaf damaged area, leaf damaged index and mite density on galled leaves during the same period in comparison to the first year of observation. The percentage of the leaves with erinea, the leaf damaged area and the mite density of Sezdang were highly and positively correlated with IAA while a negative correlation was found between the leaf damaged area and the mite density with SA and JA in the assayed years. Almost all data currently collected allowed a recognition of White Thompson, Atabaki, Koladari, Sahebi and Shahani Gerd as the least affected cultivars.



Author(s):  
Warren C. Welch ◽  
Timothy J. Harpster ◽  
Joseph W. Harpster

A station uprate provides an economical opportunity to improve the generation capacity of a power plant if all the major system components are able to handle the effects of increased generation. The magnitude of uprate from increased steam generation will be limited by the maximum capacity of the weakest link in the cycle, which for many plants is the condenser. The condensers on many units are already pushed to their limit. This is especially true if a cooling tower is employed, where the condenser inlet cooling water temperatures are high on high wet-bulb temperature days. This condition forces many units to throttle down load to prevent excursions above the backpressure limits on their turbines. For condensers limited by the present duty, however, the options have been historically limited to rebundling the whole condenser with a larger surface area design and perhaps changing the tube material to a material with a higher heat transfer coefficient. Recently, a very low cost option has been demonstrated that should be considered by any plant looking to increase condenser duty or prevent station power reductions. Advances in the proper management of steam, condensate and noncondensable flows have permitted an upgrade for almost all vintage condensers, unlocking inactive surface area without a bundle replacement or complete redesign. This paper reports the results of a condenser retrofit effort, with emphasis on an upgrade applied to a load limited condenser concurrent with a major reduction in its operating backpressure. The performance of the condenser is presented before and after the upgrade showing significant backpressure reduction and heat transfer improvement accompanied by exceptional condensate chemistry results. It will be shown that 30% of the effective condenser surface area (or similarly, an additional 30% average heat transfer coefficient) was unlocked by activating the previously idle surface area.





2017 ◽  
Vol 6 (2) ◽  
pp. 58 ◽  
Author(s):  
Daishu Yi ◽  
Timothy Schwinghamer ◽  
Yolande Dalpé ◽  
Jaswinder Singh ◽  
Shahrokh Khanizadeh

Wheat is an important crop, playing inevitable roles in human life, ranging from major food resource to raw material for biofuel. However, due to the dramatically reduced available arable areas and increasingly severe abiotic and biotic stresses, wheat production nowadays faces extreme challenges.. Many approaches have been explored to increase wheat yield including development of new cultivars. One of the most promising approaches is the application of the naturally existent arbuscular mycorrhiza (AM), a mutualistic symbiosis originated over 400 million years ago. AM have long been known to form mutualistic symbiosis with various plants to enhance yield production and to improve stress tolerance, especially drought and salinity. But the benefits vary among AM strains and plant species. Therefore, the objective of the study was to investigate the influence of four AM strains colonized on four selected spring wheat varieties under three salt concentrations (0, 50, 100 mmol/L). The results demonstrated that wheat inoculated with arbuscular mycorrhizal strains Funneliformis mosseae and Rhizoglomusirregulare mitigated yield losses caused by increased salinity stresses as well as strengthened root growth in comparison with non-inoculated plant controls. Salinity stress, however, had non-significant negative effects on most variables, except for grain yield, root surface area and root dry weight, in which a significant decrease was observed in root surface area and root dry weight with the increasing of saline concentration.



2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ezatollah Amini ◽  
Mehdi Tajvidi ◽  
Douglas W. Bousfield ◽  
Douglas J. Gardner ◽  
Stephen M. Shaler

Abstract The novel use of aqueous suspensions of cellulose nanofibrils (CNF) as an adhesive/binder in lignocellulosic-based composite manufacture requires the removal of a considerable amount of water from the furnish during processing, necessitating thorough understanding of the dewatering behavior referred to as “contact dewatering”. The dewatering behavior of a wood-CNF particulate system (wet furnish) was studied through pressure filtration tests, centrifugation, and characterization of hard-to-remove (HR) water, i.e. moisture content in the wet furnish at the transition between constant rate part and the falling rate part of evaporative change in mass from an isothermal thermogravimetric analysis (TGA). The effect of wood particle size thereby particle specific surface area on the dewatering performance of wet furnish was investigated. Permeability coefficients of wet furnish during pressure filtration experiments were also determined based on Darcy’s law for volumetric flow through a porous medium. Results revealed that specific particle surface area has a significant effect on the dewatering of wet furnish where dewatering rate significantly increased at higher specific particle surface area levels. While the permeability of the systems decreased over time in almost all cases, the most significant portion of dewatering occurred at very early stages of dewatering (less than 200 seconds) leading to a considerable increase in instantaneous dewatering when CNF particles come in contact with wood particles.



2021 ◽  
Vol 6 (2) ◽  
pp. 33-51
Author(s):  
L. I. Litvinenko ◽  
K. V. Kutsanov ◽  
L. F. Razova ◽  
A. Sh. Gadiadullina ◽  
A. G. Gerasimov ◽  
...  

The size of Artemia cysts is an important indicator of their value as a food resource; to some extent, it allows to identify populations. The data on cysts of Artemia parthenogenetic populations (diameter, chorion thickness, and presence of spots on a shell), sampled in hyperhaline lakes of Western Siberia in different years, were analyzed, as well as the data on the morphometry of Artemia adults, reared from cysts at the same salinity. Significant intra- and interpopulation variability in the indicators was established. The absolute values of the cyst diameter were in the range of 210–330 µm, the mean values for the samples – 243.5–282.9 µm, the mean values for populations – 257.8–279.6 µm; the absolute values of the decapsulated cyst diameter were in the range of 196–294 µm, the mean values for the samples – 236.5–262.6 µm, the mean values for populations – 239.9–253.2 µm; the absolute values of the cyst chorion thickness were in the range of 3.3–16.9 µm, and the mean values for populations – 6.6–12.4 µm. In the main commercial fishing lakes, which account for about 70 % of the total catch of Artemia cysts in Russia, the cysts had similar mean population sizes: 262–268 µm. The absence of intrapopulation correlation between the cyst diameter and chorion thickness is concluded; so, they cannot serve as reliable indicators, identifying Siberian populations. Statistically significant correlation (r = −0.5) was established between salinity of a mother water body and Artemia embryo diameter. Cyst spotting, not exceeding 5 % in almost all the samples, reached 24 % in cysts of Kuchukskoye Lake. Analysis of morphometric indicators of Artemia adults, reared from cysts, showed as follows: the mean body length (9.27–11.63 mm), abdomen width (0.53–0.69 mm), and distance between eyes (1.36–1.52 mm) were closely correlated with salinity of a water body (r values were of −0.76; −0.62; and −0.67, respectively). Cluster analysis of a set of morphometric indicators of Artemia adults showed the unification of populations based on salinity.



Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 578 ◽  
Author(s):  
Jiamin Sun ◽  
Sara Abednatanzi ◽  
Pascal Van Der Voort ◽  
Ying-Ya Liu ◽  
Karen Leus

The hybrid materials that are created by supporting or incorporating polyoxometalates (POMs) into/onto metal–organic frameworks (MOFs) have a unique set of properties. They combine the strong acidity, oxygen-rich surface, and redox capability of POMs, while overcoming their drawbacks, such as difficult handling, a low surface area, and a high solubility. MOFs are ideal hosts because of their high surface area, long-range ordered structure, and high tunability in terms of the pore size and channels. In some cases, MOFs add an extra dimension to the functionality of hybrids. This review summarizes the recent developments in the field of POM@MOF hybrids. The most common applied synthesis strategies are discussed, together with major applications, such as their use in catalysis (organocatalysis, electrocatalysis, and photocatalysis). The more than 100 papers on this topic have been systematically summarized in a handy table, which covers almost all of the work conducted in this field up to now.



Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3652
Author(s):  
Mohammad Reza Saeb ◽  
Navid Rabiee ◽  
Masoud Mozafari ◽  
Ebrahim Mostafavi

The composition and topology of metal-organic frameworks (MOFs) are exceptionally tailorable; moreover, they are extremely porous and represent an excellent Brunauer–Emmett–Teller (BET) surface area (≈3000–6000 m2·g−1). Nanoscale MOFs (NMOFs), as cargo nanocarriers, have increasingly attracted the attention of scientists and biotechnologists during the past decade, in parallel with the evolution in the use of porous nanomaterials in biomedicine. Compared to other nanoparticle-based delivery systems, such as porous nanosilica, nanomicelles, and dendrimer-encapsulated nanoparticles, NMOFs are more flexible, have a higher biodegradability potential, and can be more easily functionalized to meet the required level of host–guest interactions, while preserving a larger and fully adjustable pore window in most cases. Due to these unique properties, NMOFs have the potential to carry anticancer cargos. In contrast to almost all porous materials, MOFs can be synthesized in diverse morphologies, including spherical, ellipsoidal, cubic, hexagonal, and octahedral, which facilitates the acceptance of various drugs and genes.



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