A GIS-aided two-phase grey fuzzy optimization model for nonpoint source pollution control in a small watershed

A method for allocating allowable ranges of total nitrogen (TN) load to nonpoint (diffuse pollution) sources in a watershed has been developed by adopting the two-phase grey fuzzy optimization approach. Competing goals of water quality management authorities and TN load dischargers at nonpoint sources such as paddy field, upland crop field, and residential area are described with linear imprecise membership functions including interval numbers. TN load discharged from each cell of the nonpoint sources is assumed to be transported along with surface, subsurface, and river flow under the conventional first-order kinetic removal with respect to distance. The travel length of the load is estimated with a digital elevation model in a geographic information system (GIS). Uncertainty of river discharge and self-purification coefficients appearing in the TN transport model is also expressed with interval numbers. The GIS-aided grey fuzzy optimization model developed here is applied to the Seimei River watershed, Japan. By solving the optimization model, the allowable load represented by an interval number at each cell is procured, which would be a scientific base for effluent control regarding nonpoint sources in the area.     

Investigating the reduction of sodium adsorption ratio from agricultural waste by rice husk in batch scale and physical model of drain envelop

Sodium adsorption ratio (SAR) is one of the water quality indexes that whose is important due to reuse or depletion to environment. Solutes in drain water can be controlled by adsorption, chemical or biological reaction, organic envelope of drainage. Rice husk is the common option of drainage envelops in paddy fields. In this study, the ability of reduction of SAR by rice husk was evaluated in batch scale and physical model of drain envelops. In the batch experiments, the adsorption of SAR parameters was investigated by adding 2 g of rice husk into a 100 ml of sodium chloride solution. The results indicated that rice husk absorbed calcium, magnesium and sodium, respectively. By increasing the temperature, contact time and pH, adsorption of calcium, magnesium and sodium was increased; however, the higher concentration of sodium in soil solution reduced the percentage of adsorption. In a more realistic state, physical models of subsurface drainage in the paddy fields were made. Drainage envelope treatments included of rice husk (H), combination of 20 and 60 % of husk with gravel (H₂₀G₈₀ and H₆₀G₄₀) and a pipe without envelope (NE). Due to higher drain discharge and more sodium removal (lower SAR in drain water), treatment H with the discharge of 16.2 ml/min and SAR of 1.27 (meq/l)^0.5 was better in comparison with other treatments.     

Validation of dual-crop coefficient method for calculation of rice evapotranspiration under drying–wetting cycle condition

Based on data collected from rice fields under drying–wetting cycle condition, the procedure of dual-crop coefficient (K _cd) approaches was calibrated and validated to reveal its feasibility and improve its performance in rice evapotranspiration (ET _c) estimation. It was found that K _cd based on FAO-recommended basal crop coefficients (K _cb) underestimated dual-crop coefficients in monsoon climate region in East China. The recommended coefficient (K _cp) value of 1.2 was not high enough to reflect the pulse increase of rice ET _c after soil wetting. The K _cb values were calibrated as 1.52 and 0.63 in midseason and late season, and the K _cp value was adjusted as 1.29 after soil wetting in rice field under drying–wetting cycle condition. The dual-crop coefficient curves based on locally calibrated K _cbCal and K _cpCor matched well with the measured crop coefficients and performed well in calculating rice evapotranspiration from paddy fields under drying–wetting cycle condition. So it can be concluded that the procedure of dual-crop coefficient method is feasible in rice ET _c estimation, and locally calibrated K _cb and K _cp can improve its performance remarkably.     

Characterization,Pathogenicity and Chemical Control of <Emphasis Type="Italic">Streptomyces acidiscabies</Emphasis> Associated to Potato Common Scab

The pathogenicity of 10 bacterial isolates was investigated on potato, radish, carrot and beet, including sensitivity and pathogen control efficacy. The isolates were identified by morphological, biochemical and molecular methods. All isolates were pathogenic on radish, carrot, and beet, and were highly virulent on potato. Although the isolates were obtained from different locations in the El Fuerte Valley (Sinaloa, Mexico), they were similar in their morphological, physiological and biochemical characteristics. Sequences of the 16S rRNA gene obtained by PCR were identical for all isolates. These results indicate that the bacterial isolates from potato scabby tissue belong to S. acidiscabies. Furthermore, the effectiveness of fluazinam, both in vitro and under greenhouse and field conditions, represents a possibleoption for chemical control of potato common scab disease. While our results suggest that spraying at seeding is effective in controlling common scab, future studies to combine this treatment with seed dressing before planting will be conducted to determine if there is an increase in disease control.     

Copolymerization of benzyl methacrylate and a methacrylate bearing benzophenoxy and hydroxyl side groups: Monomer reactivity ratios,thermal studies and dielectric measurements

Statistical copolymers of 2-hydroxy-3-benzophenoxy propyl methacrylate (HBPPMA) and benzyl methacrylate (BzMA) in different feed ratios were synthesized by free radical copolymerization method at 60 °C in presence of AIBN initiator. The compositions of copolymer were estimated from ¹H-NMR technique. The monomer reactivity ratios of HBPPMA and BzMA were calculated as r₁ (r_HBPPMA)=0.51±0.076 and r₂ (r_BzMA)=1.07±0.140 for Kelen-Tüdos method, and was estimated as r₁=0.37±0.0006 and r₂=0.64±0.0485 according to Fineman Ross equation. The average values estimated from the two methods showed that monomer reactivity ratio of benzyl methacrylate was a slightly high in comparison to HBPPMA. The copolymer system showed an azeotropic point, which is equal to M _BzMA =m _BzMA =0.43. DSC measurements showed that the T_g’s of poly(HBPPMA) and poly(BzMA) were 84 °C and 73 °C, respectively. The T_g in the copolymer system decreased with increase in benzyl methacrylate content. The decomposition temperature of poly(BzMA) and poly(HBPPMA) occurs in a single stage at about 207 °C and 260 °C, respectively. Those of HBPPMA-BzMA copolymer systems are between decomposition temperatures of two homopolymers. The dielectric constant, dielectric loss factor and electrical conductivity were investigated depend on the frequency of the copolymers. The highest dielectric constants depending on all the studied frequencies were recorded for the poly(HBPPMA) and the copolymer containing the highest HBPPMA unit. The dielectric constant for P(HBPPMA) and P(BzMA) at 1 kHz are 6.56 and 3.22, respectively. Also, those of copolymer systems were estimated between these two values. Similarly, poly(HBPPMA) and copolymers, which are prepared under the same conditions show the dissipation factor and conductivity as well.     

Obtaining medical textiles including microcapsules of the ozonated vegetable oils

In this paper, it was aimed to obtain disposable medical textiles having antibacterial and wound healing properties, as well as biological adaption. For this purpose, the St. John’s Wort oil and flax seed oil were ozonated, and the oils were capsulated with arabic gum. The produced ozonated oils were characterized through FTIR and TGA analyses, as well as the properties of antibacterial, wound healing, and biological adaption were investigated. The produced microcapsules were examined via optical microscope and FTIR. The characterized microcapsules of the ozonated oils were applied to the textiles with padding method. After the applications, the fabrics were researched with SEM and FTIR analyses; in addition the antibacterial and wound healing properties and biological adaption of the textiles were also investigated. The results showed that the St. John’s Wort oil and flax seed oil were successfully ozonated and microcapsulated. The microcapsules of the oils could be applied to the fabric samples with the determined application recipe. The ozonated oils and the fabric samples applied microcapsules of the ozonated oils gained high antibacterial and wound healing property. In addition, the fabric samples were produced as having biological adaptation.     

The grafting of recycled polyol from waste polyurethane foam onto new polyurethane and its impact on shape recovery and water vapor permeation

Recycled polyols from waste polyurethane (PU) foams were grafted onto PU to improve the properties such as tensile strength, shape recovery, low-temperature flexibility, and water compatibility. The recycled polyol was either purified by column chromatography before grafting or was used directly for grafting. The soft segment melting temperature of PU did not notably increase with the addition of polyol, whereas the glass transition temperature increased with increased polyol content. The tensile strength sharply increased at low polyol content and decreased at high polyol content, while the strain at break did not significantly change with an increase in polyol content. The shape recovery at 10 oC notably improved compared with unmodified PU and remained high after four cyclic tests. Polyol-grafted PU demonstrated better lowtemperature flexibility and reduced the water vapor permeability of PU membranes. Overall, grafting recycled polyol onto PU significantly improved the tensile stress, shape recovery, and low-temperature flexibility of PU.     

Improvement of toughness for the hyaluronic acid and adipic acid dihydrazide hydrogel by PEG

New applications call for many new requirements. In order to improve the toughness of aldehyde hyaluronic acid (A-HA) and adipic acid dihydrazide (ADH) hydrogel, the poly(ethylene glycol) (PEG) was added. PEG content and molecular weight have little effect on the gelation time, and the composite hydrogels can form in situ within 20 seconds at room temperature. The press test showed that the hydrogels containing PEG possessed a better compression resistance, after pressed more than five times, the composite hydrogels could restore. Rheological properties were measured to evaluate the working ability and the effect of PEG on hydrogels. By analyzing the shear viscosity (η _γ=0.01), yield stress (σ ₀) and threshold shear stress (σ _c ), the addition of PEG can make the structure of composite hydrogels get loose and improve the shear resistance. Especially, PEG800 can enhance the antishear ability obviously. The amplitude sweep tests showed a broad linear viscoelastic region, indicating a wide processing range. In the meanwhile, we also found that PEG can improve the optical transmittance of xerogel evidently.     

Optimization of curing process for polymer-matrix composites based on orthogonal experimental method

In this paper, the orthogonal experimental method was carried out to optimize the curing process of aeronautical composite X850/T800 in autoclave process. Four important curing parameters including curing pressure, heating rate, curing temperature and heat preservation time were taken into account, and sixteen samples were fabricated to study the effects of the four parameters mentioned above on the curing quality by interlaminar properties test and microstructure analysis. The interlaminar properties and the interfacial bonding quality of these samples were studied by the short-beam three points bending test and scanning electron microscopy, respectively. Results revealed that the optimal curing process of X850/T800 composite laminate should be as follows: curing pressure of 0.6 MPa, heating rate of 1.5 °C/min, curing temperature of 160 °C, and heat preservation time of 120 min.     

As contamination alters rhizosphere microbial community composition with soil type dependency during the rice growing season

Rhizosphere microbes play a cardinal role in transformation and crop uptake of arsenic (As), thereby relieving or intensifying the risk of As contamination in the food webs. How rhizosphere microbiomes respond to As contamination in different paddy soils and rice growth stages is still unclear. Here, we conducted a rice pot experiment to address the effects of rice developmental stage and As contamination on the rhizosphere microbial communities in two contrast paddy soils, a yellow clayey paddy soil (YP, pH 5.1, soil organic matter 20.8 g/kg) and red paddy soil (RP, pH 6.2, soil organic matter 46.1 g/kg). The rhizosphere microbial communities were investigated using phospholipid fatty acids analysis at tillering, panicle initiation, and maturity stages. The results showed that rice growing in YP soil accumulated 2-10 times higher contents of As in root than that in RP soil. There was a significant effect of rice growing stage, independent of soil types and As treatment, on rhizosphere microbial community composition in both YP and RP soils as depicted by canonical correspondence analysis. As contamination significantly altered rhizosphere microbial community composition only in YP soil, which showed the soil type dependency of the As contamination effect. In RP soil, the higher content of soil organic matter reduced the impact of As contamination. Soil pH explained more percentage of variation in microbial community composition than soil DOC and DON did. These influences of soil physiochemical properties on heavy metal available and rhizosphere microbial community may lay the foundation for exploration of bioremediation potential.