Using Fuzzy Theory and Variable Weights for Water Quality Evaluation in Poyang Lake, China

Achieving water purity in Poyang Lake has become a major concern in recent years, thus appropriate evaluation of spatial and temporal water quality variations has become essential. Variations in 11 water quality parameters from 15 sampling sites in Poyang Lake were investigated from 2009 to 2012. An integrative fuzzy variable evaluation(IFVE) model based on fuzzy theory and variable weights was developed to measure variations in water quality. Results showed that: 1) only chlorophyll-a concentration and Secchi depth differed significantly among the 15 sampling sites(P < 0.01), whereas the 11 water quality parameters under investigation differed significantly throughout the seasons(P < 0.01). The annual variations of all water quality variables except for temperature, electrical conductivity, suspended solids and total phosphorus were considerable(P < 0.05). 2) The IFVE model was reasonable and flexible in evaluating water quality status and any possible ′bucket effect′. The model fully considered the influences of extremely poor indices on overall water quality. 3) A spatial analysis indicated that anthropogenic activities(particularly industrial sewage and dredging) and lake bed topography might directly affect water quality in Poyang Lake. Meanwhile, hydrological status and sewage discharged into the lake might be responsible for seasonal water quality variations.

The Curing Process and Elastic Modulus of HTPB-Containing Polyurethanes

By means of the functionality distribution deduced and weight averaged functionality a and molecular size vb2, the sol-gel distribution equations of HTPB(Hydroxyl terminated polybutadiene) + TDI (Toluene-2, 4-diisocyanate) expressed by the model of Aai-B2 type polycondensation were solved and the elastic modulus were calculated. The experimental results of HTPB+TDI curing process indicate that a, vb2 and functionality distribution function are available basically.

Synergistic Effect of Adjuvant Green Orange Peel Oil on Different Herbicides

[Objective] The paper was to explore the synergistic effect of a novel adjuvant green orange peel oil on different herbicides in direct sowing paddy field. [Method] The synergistic test of green orange peel oil on 10% cyanoflurate SC and 10% metamifop EC was conducted in 2019.[Result] The control effect of green orange peel oil 150 mL/hm^(2)+ 10% cyanoflurate SC 1 275 mL/hm^(2) on Echinochloa crusgalli and Leptochloa chinensis were significantly superior to that of 10% cyanoflurate SC 1 500 mL/hm^(2). The control effects of green orange peel oil 150 m L/hm^(2)+10%cyanoflurate SC 1 200 m L/hm^(2) on E. crusgalli and L. chinensis was equivalent to that of 10% cyanoflurate SC 1 500 mL/hm^(2). The control effect of green orange peel oil 150 mL/hm^(2)+ 10% metamifop EC 1 275 mL/hm^(2) on E. crusgalli and L. chinensis was equivalent to that of 10% metamifop EC 1 500 m L/hm^(2). [Conclusion] The green orange peel oil had certain synergistic effect on cyanoflurate and metamifop.

Plastic scintillator detector for qualitative and quantitative measurements of gamma radiation

Background Plastic scintillator detectors are rugged and easily manufactured in desired shape,sizes and response time to gamma radiation is prompt as compared with any other scintillator detectors.Being popular these detectors are used in radiation monitors one of the application to restrict radioactive material movement.These are used in gross counting mode to know the presence of radioactivity.Therefore secondary survey is required to know the nature of the radionuclides.Purpose The feasibility study of Cylindrical Plastic Scintillator Detector(CPSD)was carried out for the qualitative and quantitative assessment of gamma emitting radionuclides.Methods In this work limited gamma spectrometry was carried out using NE110 equivalent cylindrical plastic scintillating material of 5.1 cm diameter and 100 cm long.CPSD is optically coupled to photomultiplier tube(PMT).The detector signal is processed using preamplifier,shaping amplifier and further analysed by a multi channel analyser(MCA).CPSD gamma spectrum consists of Compton continuum and Gaussian shaped Compton edge energy(λ_(e))appearing as Compton maxima energy(λ_(max)).Photon transport simulation is used to characterizeλ_(max) as a signature for radionuclides emitting gamma energy/energies.In case of unresolved gamma energies,it appears as weighted effective Compton maxima energy.The prominent gamma energies observed across nuclear industries are in the energy range 0.03–3 MeV.It is grouped as low energy,intermediate energy,high energy and ultra-high energy window.The simulated spectrum is obtained suing Gaussian broadening parameters deduced from experimentally measured spectrum.The efficiency response function is developed from simulated response of detector to standard gamma sources under known source detector configurations.Results The mono energetic gamma emitting radioisotopes are identified againstλ_(max) from data library.Qualitative analysis of spectrum is used to discriminate artificial radioactive material from naturally occurring radioactive material using gamma photon,corresponding Compton edge and expected Compton maxima in each energy window.The provisional quantitative assessment is carried out using efficiency deduced from response function.The detection efficiency varies within 1%–0.2%for 0.03 to 3 MeV gamma energies.In this study efficiency for ^(137)Cs source is 0.26%with FWHM 0.092 MeV and the results re within 15%for the measured activity.Estimated sensitivity and spectral dose rate coefficient for CPSD are 77 cps/µR/h and 44.29 nGy/kcps respectively.The MDA or MDL of the most prominent radioisotopes used in nuclear industry are estimated.CPSD showed an ability to detect 149 kBq,^(137)Cs radioisotope at 1 m distance.Conclusion CPSD can be utilised for gamma isotope identification with limited gamma spectroscopy tool in contamination and dose rate measurements monitors.

Effects of a dynamic membrane formed with polyethylene glycol on the ultrafiltration of natural organic matter

The formation of a dynamic membrane(DM)was investigated using polyethylene glycol(PEG)(molecular weight of 35000 g/mol,concentration of 1 g/L).Two natural organic matters(NOM),Dongbok Lake NOM(DLNOM)and Suwannee River NOM(SRNOM)were used in the ultrafiltration experiments along with PEG.To evaluate the effects of the DM with PEG on ultrafiltration,various transport experiments were conducted,and the analyses of the NOM in the membrane feed and permeate were performed using high performance size exclusion chromatography,and the effective pore size distribution(effective PSD)and effective molecular weight cut off(effective MWCO)were determined.The advantages of DM formed with PEG can be summarized as follows:(1)PEG interferes with NOM transmission through the ultrafiltration membrane pores by increasing the retention coefficient of NOM in UF membranes,and(2)low removal of NOM by the DM is affected by external factors,such as pressure increases during UF membrane filtration,which decreases the effective PSD and effective MWCO of UF membranes.However,a disadvantage of the DM with PEG was severe flux decline;thus,one must be mindful of both the positive and negative influences of the DM when optimizing the UF performance of the membrane.