scholarly journals Retrieval of Chlorophyll a Concentration in Water Considering High-Concentration Samples and Spectral Absorption Characteristics

2021 ◽  
Vol 13 (21) ◽  
pp. 12144
Author(s):  
Yun Xue ◽  
Yi-Min Wen ◽  
Zhong-Man Duan ◽  
Wei Zhang ◽  
Fen-Liang Liu
Keyword(s):  
Large Deviations ◽  
Absorption Characteristic ◽  
Spectral Absorption ◽  
Characteristic Parameters ◽  
High Concentration ◽  
Chl A ◽  
Removal Method ◽  
Inversion Model ◽  
Absorption Characteristics ◽  
Better Than

The envelope removal method has the advantage of suppressing the background spectrum and expanding the weak absorption characteristic information. However, for second-class water bodies with a relatively complex water quality, there are few studies on the inversion of chlorophyll a (Chl-a) concentration in water bodies that consider the spectral absorption characteristics. In addition, the current research on the inversion of the Chl-a concentration was carried out under the condition of sample concentration equilibrium. For areas with a highly variable Chl-a concentration, it is still challenging to establish a highly applicable and accurate Chl-a concentration inversion model. Taking Dongting Lake in China as an example, this study used high-concentration samples and spectral absorption characteristics to invert the Chl-a concentration. The decap method was used to preprocess the high-concentration samples with large deviations, and the envelope removal method was used to extract the spectral absorption characteristic parameters of the water body. On the basis of the correlation analysis between the water Chl-a concentration and the spectral absorption characteristics, the water Chl-a concentration was inverted. The results showed the following: (1) The bands that were significantly related to the Chl-a concentration and had a large correlation coefficient were mainly located in the three absorption valleys (400–580, 580–650, and 650–710 nm) of the envelope removal curve. Moreover, the correlation between the Chl-a concentration and the absorption characteristic parameters at 650–710 nm was better than that at 400–580 nm and 580–650 nm. (2) Compared with the conventional inversion model, the uncapped inversion model had a higher RP2 and a lower RMSEP, and was closer to the predicted value of the 1:1 line. Moreover, the performance of the uncapped inversion model was better than that of the conventional inversion model, indicating that the uncapped method is an effective preprocessing method for high-concentration samples with large deviations. (3) The predictive capabilities of the ER_New model were significantly better than those of the R_New model. This shows that the envelope removal method can significantly amplify the absorption characteristics of the original spectrum, which can significantly improve the performance of the prediction model. (4) From the inversion models for the absorption characteristic parameters, the prediction models of A650–710 nm_New and D650–710 nm_New exhibited the best performance. The three combined models (A650–710 nm&D650–710 nm_New, A650–710 nm&NI_New, A650–710 nm&DI_New) also demonstrated good predictive capabilities. This demonstrates the feasibility of using the spectral absorption feature to retrieve the chlorophyll concentration.

Sound Absorption Characteristics of a Single Micro-Perforated Panel Backed by a Natural Fiber Absorber Material

2020 ◽  
Vol 307 ◽  
pp. 291-296 ◽  
Author(s):  
Meifal Rusli ◽  
Fakhrur Rahman ◽  
Hendery Dahlan ◽  
Gusriwandi ◽  
Mulyadi Bur
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Absorption Characteristic ◽  
Coconut Fiber ◽  
Single Leaf ◽  
Absorber Material ◽  
Resonance Absorber ◽  
Absorption Characteristics

A micro-perforated panel (MPP) works as a Helmholtz-type resonance absorber formed by an air-gab cavity in order to minimize the reflected sound effectively at a selective resonance frequency. Furthermore, the use of natural fibers as sound absorbing materials recently has attracted more attention because it is completely biodegradable, environmental friendly and more economical. In this paper, the combination of MPP and natural fiber as sound absorptive material is investigated. The MPP is made of a transparent acrylic board with 1.5 mm thickness and backed by a coconut fiber panel. The effect of the fiber panel that inserted in the air-gab cavity to the sound absorption characteristic of a single leaf MPP is observed. Sound absorption coefficient is measured by transfer function method using two microphones-impedance tube. It is found that the sandwich model of MPP backed by a coconut fiber changes the sound absorption characteristics of MPP by shifting the maximum absorption coefficient into the lower frequency and making a wider band of frequency absorption. Moreover, the air-gab cavity between MPP and fiber panel give fewer contribution to construct the MPP frequency resonant than the natural fiber panel one.

scholarly journals Remote sensing inversion of lake water quality parameters based on ensemble modelling

2020 ◽  
Vol 143 ◽  
pp. 02007
Author(s):  
Li Xiaojuan ◽  
Huang Mutao ◽  
Li Jianbao
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Entropy Weight ◽  
Ensemble Modelling ◽  
Chl A ◽  
Inversion Model ◽  
Entropy Weight Method ◽  
Weight Method

In this paper, combined with water quality sampling data and Landsat8 satellite remote sensing image data, the inversion model of Chl-a and TN water quality parameter concentration was constructed based on machine learning algorithm. After the verification and evaluation of the inversion results of the test samples, Chl-a TN inversion model with high correlation between model test results and measured data was selected to participate in remote sensing inversion ensemble modelling of water quality parameters. Then, the ensemble remote sensing inversion model of water quality parameters was established based on entropy weight method and error analysis. By applying the idea of ensemble modelling to remote sensing inversion of water quality parameters, the advantages of different models can be integrated and the precision of water quality parameters inversion can be improved. Through the evaluation and comparative analysis of the model results, the entropy weight method can improve the inversion accuracy to some extent, but the improvement space is limited. In the verification of the two methods of ensemble modelling based on error analysis, compared with the optimal results of a single model, the determination coefficient (R2) of Chlorophyll a and TN concentration inversion results was increased from 0.9288 to 0.9313 and from 0.8339 to 0.8838, and the root mean square error was decreased from 14.2615 μ/L to 10.4194 μ/L and from1.1002mg/L to 0.8621mg/L. At the same time, with the increase of the number of models involved in the set modelling, the inversion accuracy is higher.

scholarly journals Primary Standardization of Assays for Anticonvulsant Drugs: Comparison of Accuracy and Precision

2002 ◽  
Vol 48 (11) ◽  
pp. 1963-1969 ◽  
Author(s):  
John F Wilson ◽  
Ian D Watson ◽  
John Williams ◽  
Pat A Toseland ◽  
Alison H Thomson ◽  
...  
Keyword(s):  
Open Systems ◽  
Calibration Error ◽  
High Concentration ◽  
External Quality Assessment Scheme ◽  
The United Kingdom ◽  
Accuracy And Precision ◽  
Accuracy Of Measurements ◽  
The Mean ◽  
Analytical Platforms ◽  
Better Than

Abstract Background: The accuracy and precision of methods for the measurement of the anticonvulsants phenytoin, phenobarbital, primidone, carbamazepine, ethosuximide, and valproate in human serum were assessed in 297 laboratories that were participants in the United Kingdom National External Quality Assessment Scheme (UKNEQAS). Methods: We distributed lyophilized, serum-based materials containing low, medium, and high weighed-in concentrations of the drugs. The 297 participating laboratories received the materials on two occasions, 7 months apart. Expected concentrations were determined by gas chromatography or HPLC methods in five laboratories using serum-based NIST reference materials as calibrators. Results: In general, bias was consistent across concentrations for a method but often differed in magnitude for different drugs. Bias ranged from −1.9% to 8.6% for phenytoin, −2.7% to 3.1% for phenobarbital, −2.7% to 0.5% for primidone, −8.6% to 0.3% for carbamazepine, −5.6% to 2.0% for ethosuximide, and −7.2% to 0.1% for valproate. Intralaboratory sources of imprecision significantly exceeded interlaboratory sources for many drug/method combinations. The mean CVs for intra- and interlaboratory errors for the different drugs were 6.3–7.8% and 3.3–4.2%, respectively. Conclusions: For these long-established and relatively high-concentration analytes, the closed analytical platforms generally performed no better than open systems or chromatography, where use of calibrators prepared in house predominated. To improve the accuracy of measurements, work is required principally by the manufacturers of immunoassays to ensure minimal calibration error and to eliminate batch-to-batch variability of reagents. Individual laboratories should concentrate on minimizing dispensing errors.

scholarly journals Performance Evaluation of Hybrid Air Purification System with Vegetation Soil and Electrostatic Precipitator Filters

2020 ◽  
Vol 12 (13) ◽  
pp. 5428
Author(s):  
Aya Elkamhawy ◽  
Choon-Man Jang
Keyword(s):  
Removal Efficiency ◽  
Electrostatic Precipitator ◽  
Fine Particulate Matter ◽  
Air Purification ◽  
High Concentration ◽  
Air Velocity ◽  
Removal Method ◽  
Purification System ◽  
Reduction Efficiency ◽  
Individual Module

This paper describes designing, manufacturing, and evaluating an eco-friendly modular-type air purification system to enhance the removal efficiency of fine particulate matter (PM) in urban public spaces, especially in hotspots. This system consists of artificial soil based-vegetation and electrostatic precipitator (ESP) filters. Unlike the so-called passive removal method, which adsorbs fine PM only by the leaves of plants, the vegetation soil filter based on multi-layered different artificial soils adopts an active removal method in which air purification is performed in the soil itself, bypassing external air by using the air circulation fan in the soil. The ESP filter is designed and evaluated to have a high fine PM removal efficiency, even at high suction velocity, to remove large amounts of outdoor fine PM. Throughout the experimental measurements on the hybrid air purification system with vegetation soil and ESP filters, it is observed that the vegetation soil filter has a 78.5% reduction efficiency for PM2.5 and a 47% for PM10 at the inlet air velocity of 0.15 m/s. The ESP filter also has a 73.1% reduction efficiency for PM2.5 and 87.3% for PM10 at an inlet air velocity of 3 m/s. Based on the performance evaluations of the vegetation soil filter and the ESP filter, it is noted that each individual module will be applied to an air purification tower with vertical expansion and installed in a high concentration area of fine PM in a downtown area to contribute to the fine PM reduction in the community.

The land use plan and water quality prediction for the Saemangeum reclamation project

2009 ◽  
Vol 59 (7) ◽  
pp. 1397-1408 ◽  
Author(s):  
D. H. Hwang ◽  
J. Y. Choi ◽  
S. M. Yi ◽  
D. H. Han ◽  
S. H. Jang
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Water Quality Management ◽  
Treated Wastewater ◽  
High Concentration ◽  
Reclaimed Land ◽  
Chl A ◽  
Reclamation Project ◽  
Land Use Plan

As the final closure of the world's longest sea dike of 33 km, the use of the Saemangeum reclaimed land becomes an issue in Korea. The Korean government has proclaimed that the Saemangeum Reclamation Project will be handled in an environmentally friendly manner but its effect on the water quality of reservoirs has always been controversial. This study was conducted to estimate the water quality of the Saemangeum reservoir using WASP5 according to the new land use plan adopted in 2007. Predictions on water quality shows that Dongjin reservoir would meet the standards for COD, T-P, and Chl-a if the wastewater from the Dongjin region was properly managed. However, T-P and Chl-a in Mangyeong reservoir would exceed the standards even without releasing the treated wastewater into the reservoir. With further reductions of 20% for T-P and Chl-a from the mouth of Mangyeong river, the water quality standards in the reservoir were achieved. This means that additional schemes, as well as water quality management programs established in the Government Master Plan in 2001, should be considered. Although the Saemangeum reservoir would manage to achieve the standards, it will enter a eutrophic state due to the high concentration of nutrients.

Effects of Different Reagent on the Separation of Starch and Protein in Corn Endosperm

2014 ◽  
Vol 644-650 ◽  
pp. 5227-5230
Author(s):  
Rong Yan ◽  
Xin Hua Li ◽  
Xiao Jun Qi
Keyword(s):  
Lactic Acid ◽  
Distilled Water ◽  
Starch Granules ◽  
High Concentration ◽  
Corn Flour ◽  
Sulfurous Acid ◽  
Chemical Reagents ◽  
Sulfite Solution ◽  
Better Than

Corn and corn flour were steeped with different chemical reagents ,sulfurous acid (0.1%, 0.2%, 0.1%)、NaOH (0.1%, 0.3%, 0.5%)、alcohol (65%, 75%, 65%)、lactic acid (0.3%, 0.5%, 0.3%)、L - cysteine (0.6%, 1.0%, 1.4%) ,using distilled water as control. The separation of starch and protein in corn endosperm steeped under different reagents were analyzed using the amount of free starch measuring by iodine colorimety.The results show that under the action of different concentration of NaOH、sulfurous acid、lactic acid,the measured value of free starch in both corn and corn flour were increased and were higher than control,with the extending of the soak time and increase of reagent concentration.The effect of NaOH is the best,but when the NaOH concentration was above 0.5%, the amount of free starch began to decline. The starch granules were destroyed by the high concentration of alkali. The effect of Sulfite solution is good also, and the observed value of free starch slightly higher than the lactic acid. The effect of different concentration L-cysteine on corn was almost the same as control,but the effect of separation on corn flour was obviously enhanced and better than sulfurous acid,especially concentration above 1.0%.There was no starch granules out of corn and corn flour by alcohol soaking.

Spectral absorption characteristics of antihistaminic drugs; Relationship to ultraviolet erythema

1949 ◽  
Vol 20 (4) ◽  
pp. 229-242 ◽  
Author(s):  
Alex S. Friedlaender ◽  
Sidney Friedlaender ◽  
J.M. Vandenbelt
Keyword(s):  
Spectral Absorption ◽  
Antihistaminic Drugs ◽  
Absorption Characteristics

scholarly journals Ecophysiological Studies of A Cereal Crop Oryza sativa L. with Zinc Stress

2018 ◽  
Vol 4 (4) ◽  
pp. 311-313
Author(s):  
Sasmita Kumari Behura ◽  
Mamata Mohapatra ◽  
B.K. Mohanty
Keyword(s):  
Seed Germination ◽  
Zinc Sulphate ◽  
Shoot Growth ◽  
Negative Impact ◽  
Oryza Sativa L ◽  
Total Chlorophyll ◽  
High Concentration ◽  
Zinc Stress ◽  
Chl A ◽  
Root And Shoot Growth

Plants exposed to zinc stress at high concentration inhibit seed germination, seedling growth and development. The germination data showed that there is a negative impact of concentration of zinc sulphate on the germination of seeds. Root and shoot growth of seedlings was worse affected when exposed to higher concentration on ZnSO4. Shoots were more affected than roots. Morphologically they look different from normal roots by their shape and size. Zn toxicity inhibits the chlorophyll formation and with the increase in concentration of the toxicant the exposed seedlings showed a decline in chl-a (chlorophyll-a), chl-b (chlorophyll – b) and total chlorophyll pigment content. Conclusively, our result shows that zinc sulphate at higher concentration decreases seed germination, chl-a, chl-b and total chlorophyll content and also decreases root and shoot growth of plants.

scholarly journals Photocatalytic decomposition of gaseous formaldehyde usingTiO2,SiO2−TiO2and Pt−TiO2

2003 ◽  
Vol 5 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Byung-Yong Lee ◽  
Sung-Wook Kim ◽  
Sung-Chul Lee ◽  
Hyun-Ho Lee ◽  
Suk-Jin Choung
Keyword(s):  
Photocatalytic Decomposition ◽  
Commercial Application ◽  
Reverse Effect ◽  
High Concentration ◽  
Visible Spectra ◽  
Photocatalytic Activities ◽  
High Metal ◽  
Uv Visible ◽  
Gaseous Formaldehyde ◽  
Better Than

In this study, in order to improve the photocatalytic decomposition activities of formaldehyde,TiO2catalyst modified withSiO2substitution and metal (Pt, Cu and Fe) impregnation, were tested. In case ofTiO2substituted bySiO2, the optimal catalytic activity was found at the mole ration of 2 : 8. Among the metal impregnatedTiO2, the Pt impregnatedTiO2showed the best activity even better than that of P-25 which is widely used in commercial application. However, Cu and Fe impregnatedTiO2showed the reverse effect. In the case ofSiO2substitutedTiO2the observed values of photoluminescence spectroscopy were quite proportional to the photocatalytic activities depending upon the mole ratio ofSiO2toTiO2. However, for the samples of metal impregnatedTiO2, the reverse relationships were found. In UV-visible spectra for metal impregatedTiO2, the transmittance value was reduced depending upon the loading of metals. The enhanced photocatalytic activity for high metal loading onTiO2might be associated with the high concentration of excited electron that was monitored through UV-visible spectra.

scholarly journals HOG-Independent Osmoprotection by Erythritol in Yeast Yarrowia lipolytica

Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1424
Author(s):  
Dorota A. Rzechonek ◽  
Mateusz Szczepańczyk ◽  
Guokun Wang ◽  
Irina Borodina ◽  
Aleksandra M. Mirończuk
Keyword(s):  
Transcription Factor ◽  
Yarrowia Lipolytica ◽  
Carbon Sources ◽  
Hyperosmotic Stress ◽  
Sensitive Strain ◽  
The Other ◽  
High Concentration ◽  
Other Hand ◽  
Yeast Yarrowia Lipolytica ◽  
Better Than

Erythritol is a polyol produced by Yarrowia lipolytica under hyperosmotic stress. In this study, the osmo-sensitive strain Y. lipolytica yl-hog1Δ was subjected to stress, triggered by a high concentration of carbon sources. The strain thrived on 0.75 M erythritol medium, while the same concentrations of glucose and glycerol proved to be lethal. The addition of 0.1 M erythritol to the medium containing 0.75 M glucose or glycerol allowed the growth of yl-hog1Δ. Supplementation with other potential osmolytes such as mannitol or L-proline did not have a similar effect. To examine whether the osmoprotective effect might be related to erythritol accumulation, we deleted two genes involved in erythritol utilization, the transcription factor Euf1 and the enzyme erythritol dehydrogenase Eyd1. The strain eyd1Δ yl hog1Δ, which lacked the erythritol utilization enzyme, reacted to the erythritol supplementation significantly better than yl-hog1Δ. On the other hand, the strain euf1Δ yl-hog1Δ became insensitive to supplementation, and the addition of erythritol could no longer improve the growth of this strain in hyperosmotic conditions. This indicates that Euf1 regulates additional, still unknown genes involved in erythritol metabolism.

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