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221.
This study evaluated the potential application of an atmospheric plasma (AP) treatment as a pre-treatment for digital textile printing (DTP) of polyester (PET) fabrics and cotton, in order to determine its viability as an alternative to the usual chemical treatment. The surface properties of the AP-treated fabrics were examined through scanning electron microscopy (SEM) and contact angle, and the physical properties, such as electrostatic voltage and water absorbance, were tested. The properties of cotton and PET with the AP treatment were found to be dependent on number of repetitions and electric voltage. Although no remarkable surface differences were observed by SEM in the fabrics before and after treatment, the static contact angle of the PET after AP treatment was decreased from 85 ° to 24 ° at wave. In addition, the charge decay time decreased as the voltage and number of treatments increased. The absorption height of PET changed after exposure to 7 mm with increasing measurement time. The K/S with and without the AP pre-treated and DTP finished cotton was better than that with the usual chemical modification. In PET, the 0.5 kW and 1 time AP-treated specimen showed the highest K/S values. 相似文献
222.
To evaluate the performance of new rice establishment methods viz., system of rice intensification (SRI) and integrated crop management (ICM), a field study was conducted during 2008–11 in South Garo Hills, Meghalaya, foot hills of Eastern Himalayas, India. Field demonstrations were undertaken during wet seasons of 2008–11 and socio-economic information in the context of farmer’s realities were obtained during 2010–11 using a well structured questionnaire administered to 134 farmers. The results indicated that the average higher productivity of rice under SRI and ICM demonstration was 209.9 and 185.4 %, respectively, over conventional rice culture (CRC). The SRI and ICM methods of rice cultivation could save seeds (97.56 and 60.98 %), saving water (78.05 and 63.66 %), reduce cost (70.33 %), higher yield etc. compared to CRC. The main reasons for non-adoption of SRI/ICM was related to involvement of more efforts, faith towards traditional practices, ignorance and lack of knowledge on scientific water management. The net-return of $816.69, $706.63 and $51.48/ha was realized under SRI, ICM and CRC, respectively. The co-efficient of multiple determinations (R 2) of the production function was 0.695 in SRI, 0.714 in ICM and 0.734 in CRC which indicated that about 69.5, 71.4 and 73.4 % of the variation in rice productivity under SRI, ICM and CRC, respectively were explained by the independent variable and remaining 30.5, 28.6 and 26.6 %., respectively in SRI, ICM and CRC were as a result of non-inclusion of some explanatory variables as well as other factors outside the farmers control. 相似文献
223.
Nylon 4, which can be synthesized by anionic ring-opening polymerization, has good mechanical properties and a very high affinity for water owing to its high polarity. On the other hand, despite its high melting temperature, the polymer has not been commercialized because of its low thermal stability. In this study, copolymerization of 2-pyrrolidone (C4) with 2-piperidone (C5) was performed to reduce the melting temperature of Nylon 4 homopolymer. The copolymerization reaction was controlled by changing the comonomer content, catalyst content, temperature, initiator content, and reaction time. The Nylon copolymers were characterized by 1H-nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The hydrophilic properties of Nylon 4 and its copolymers were evaluated by surface free energy analysis and moisture regain measurement. The intrinsic viscosity and polymerization yield of Nylon 4 increased with increasing catalyst concentration until 5 mole% and decreased with further increases in catalyst loading. The proton NMR spectrum revealed the composition of the Nylon 4/5 copolymer to be 62.5 % C4 moiety at a 5:5 comonomer feed ratio. The melting temperature of the Nylon 4/5 copolymers decreased considerably according to the composition. The moisture regain of the Nylon 4/5 copolymer was higher than 6.4 % even at 77.3 % C4 in composition. 相似文献
224.
Chang Soo Lee Kwan Han Yoon Jae Cheol Park Hong-Un Kim Young-Bin Park 《Fibers and Polymers》2014,15(7):1493-1499
Poly(ethylene terephthalate) (PET)/CaCO3 and PET/modified-CaCO3 (m-CaCO3) nanocomposites were prepared by melt blending. The morphology indicated that m-CaCO3 produced by reacting sodium oxalate and calcium chloride, was well dispersed in PET matrix and showed good interfacial interaction with PET compared to CaCO3. No significant differences in the thermal properties such as, glass transition, melting and degradation temperatures, of the nanocomposites were observed. The thermal shrinkage of PET at 120 °C was 10.8 %, while those of PET/CaCO3 and PET/m-CaCO3 nanocomposites were 2.9–5.2 % and 1.2–2.8 %, respectively depending on filler content. The tensile strength of PET/CaCO3 nanocomposite decreased with CaCO3 loading, whereas that of PET/m-CaCO3 nanocomposites at 0.5 wt% loading showed a 17 % improvement as compared to neat PET. The storage modulus at 120 °C increased from 1660 MPa for PET to 2350 MPa for PET/CaCO3 nanocomposite at 3 wt% loading, and 3230 MPa for PET/m-CaCO3 nanocomposite at 1 wt% loading. 相似文献
225.
Park Jong-Yoon Yu Young-Seok Hwang Soon-Jin Kim Chulgoo Kim Seong-Joon 《Paddy and Water Environment》2014,12(1):65-75
Suitable and practicable best management practices (BMPs) need to be developed due to steadily increasing agricultural land development, intensified fertilization practices, and increased soil erosion and pollutant loads from cultivated areas. The soil and water assessment tool model was used to evaluate the present and future proper BMP scenarios for Chungju dam watershed (6,642 km2) of South Korea, which includes rice paddy and upland crop areas. The present (1981–2010) and future (2040s and 2080s) BMPs of streambank stabilization, building recharge structures, conservation tillage, and terrace and contour farming were examined individually in terms of reducing nonpoint source pollution loads by applying MIROC3.2 HiRes A1B and B1 scenarios. Streambank stabilization achieved the highest reductions in sediment and T-N, and slope terracing was a highly effective BMP for sediment and T-P removal in both present and future climate conditions. 相似文献
226.
Evaluation of MODIS NDVI and LST for indicating soil moisture of forest areas based on SWAT modeling
Park Jong-Yoon Ahn So-Ra Hwang Soon-Jin Jang Cheol-Hee Park Geun-Ae Kim Seong-Joon 《Paddy and Water Environment》2014,12(1):77-88
This study examined the capability of remotely sensed information gained using the terra moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) and land surface temperature (LST) to explain forest soil moisture. The soil and water assessment tool (SWAT) was used for the analysis. Nine years (2000–2008) of monthly MODIS NDVI and LST data from a 2,694.4 km2 watershed consisting of forest-dominant areas in South Korea were compared with SWAT simulated soil moisture. Before the analysis, the SWAT model was calibrated and verified using 9 years of daily streamflow at three gauging stations and 6 years (2003–2008) of daily measured soil moisture at three locations within the watershed. The average Nash–Sutcliffe model efficiency during the streamflow calibration and validation was 0.72 and 0.70, respectively. The SWAT soil moisture showed a higher correlation with MODIS LST during the forest leaf growing period (March–June) and with MODIS NDVI during the leaf falling period (September–December). Low correlation was observed in the year of frequent rains, regardless of the leaf periods. 相似文献
227.
Jin-Kyu Rhee Ok Kyu Park Aeju Lee Dae Hyeok Yang Kyeongsoon Park 《Marine drugs》2014,12(12):6038-6057
Theranostics is an integrated nanosystem that combines therapeutics with diagnostics in attempt to develop new personalized treatments with enhanced therapeutic efficacy and safety. As a promising therapeutic paradigm with cutting-edge technologies, theranostic agents are able to simultaneously deliver therapeutic drugs and diagnostic imaging agents and also monitor the response to therapy. Polymeric nanosystems have been intensively explored for biomedical applications to diagnose and treat various cancers. In recent years, glycol chitosan-based nanoagents have been developed as dual-purpose materials for simultaneous diagnosis and therapy. They have shown great potential in cancer therapies, such as chemotherapeutics and nucleic acid and photodynamic therapies. In this review, we summarize the recent progress and potential applications of glycol chitosan-based fluorescent theranostic nanoagents for cancer treatments and discuss their possible underlying mechanisms. 相似文献
228.
Chitin and chitosan oligosaccharides (COS) have been traditionally obtained by chemical digestion with strong acids. In light of the difficulties associated with these traditional production processes, environmentally compatible and reproducible production alternatives are desirable. Unlike chemical digestion, biodegradation of chitin and chitosan by enzymes or microorganisms does not require the use of toxic chemicals or excessive amounts of wastewater. Enzyme preparations with chitinase, chitosanase, and lysozymeare primarily used to hydrolyze chitin and chitosan. Commercial preparations of cellulase, protease, lipase, and pepsin provide another opportunity for oligosaccharide production. In addition to their hydrolytic activities, the transglycosylation activity of chitinolytic enzymes might be exploited for the synthesis of desired chitin oligomers and their derivatives. Chitin deacetylase is also potentially useful for the preparation of oligosaccharides. Recently, direct production of oligosaccharides from chitin and crab shells by a combination of mechanochemical grinding and enzymatic hydrolysis has been reported. Together with these, other emerging technologies such as direct degradation of chitin from crustacean shells and microbial cell walls, enzymatic synthesis of COS from small building blocks, and protein engineering technology for chitin-related enzymes have been discussed as the most significant challenge for industrial application. 相似文献
229.
Kim Hyoung-Bum ;Kim Seoung-Jun ;Tu Xin-Cheng ;Park Seung-Ha ;Kim Seoung-Jun ;Tu Xin-Cheng ;Park Seung-Ha 《排灌机械》2014,(5):369-372
The effect of streamwise vortices generated from passive vortex generators was investigated to manipulate the separation bubble behind the vertical fence. The experiments were carried out in a circulating water channel and the velocity fields were measured using 2D and stereoscopic PIV method.The distance between the vortex generator and fence and the effect of the Reynolds number were investigated. In addition,the effect of boundary layer thickness was also investigated. The averaged recirculation lengths were compared with that of uncontrolled fence flow. The results showed the oscillatory variation of recirculation region appeared under the existence of vortex generators. The reduction of the separation bubble became larger when the fence was submerged in the thick boundary layer with increasing the distance between the generator and fence. When the boundary layer is thin,vortex generator can only suppress the separation bubble under the specific condition. 相似文献
230.
Steffen S. Madsen Stephen D. McCormick Graham Young Jeanette S. Endersen Richard S. Nishioka Howard A. Bern 《Fish physiology and biochemistry》1994,13(1):1-11
Several experiments were performed to investigate the physiology of seawater acclimation in the striped bass, Morone saxatilis. Transfer of fish from fresh water (FW) to seawater (SW; 31–32 ppt) induced only a minimal disturbance of osmotic homeostasis.
Ambient salinity did not affect plasma thyroxine, but plasma cortisol remained elevated for 24h after SW transfer. Gill and
opercular membrane chloride cell density and Na+,K+-ATPase activity were relatively high and unaffected by salinity. Average chloride cell size, however, was slightly increased
(16%) in SW-acclimated fish. Gill succinate dehydrogenase activity was higher in SW-acclimated fish than in FW fish. Kidney
Na+, K+-ATPase activity was slightly lower (16%) in SW fish than in FW fish. Posterior intestinal Na+,K+-ATPase activity and water transport capacity (Jv) did not change upon SW transfer, whereas middle intestinal Na+,K+-ATPase activity increased 35% after transfer and was correlated with an increase in Jv (110%). As salinity induced only minor changes in the osmoregulatory organs examined, it is proposed that the intrinsic euryhalinity
of the striped bass may be related to a high degree of “preparedness” for hypoosmoregulation that is uncommon among teleosts
studied to data. 相似文献