Cu2+/polyacrylonitrile composite fibers were prepared by electrospinning, and then Cu/carbon nanofibers (denoted as Cu/ CNF-X; X = Cu content, 0, 3, or 5 wt%) were formed by calcining them. The effects of Cu2+ content and carbonization temperature on the conductivity and electrothermal conversion of Cu/CNF-X were investigated. The results revealed that the conductivity and electrothermal properties of Cu/CNF-X improve with the increase in the Cu2+ content and carbonization temperature. When the carbonization temperature was 800, 900, or 1000 °C, the conductivity of Cu/CNF-5 (0.08, 0.68, or 2.48 S/cm, respectively) increased to 1.6, 1.5, or 1.6 times that of Cu/CNF-0, respectively. The highest instantaneous surface temperatures of Cu/CNF-5 calcined at 800, 900, and 1000 °C (36, 145, and 270.2 °C, respectively) increased by 4, 25.5, and 44.6 °C, respectively, compared with those of the corresponding Cu/CNF-0 samples (32, 120.3, and 225.6 °C, respectively). Thus, the addition of a small amount of Cu2+ effectively improved the conductivity and electrothermal conversion performance of Cu/CNF-X, which has potential application value in industrial products in the future.
Seawater evaporation and purification powered by solar energy are considered as a promising approach to alleviate the global freshwater crisis, and the development of photothermal materials with high efficiency is imminent. In this study, cellulose nanofiber (CNF)/MXene/Ni chain (CMN) aerogels were successfully synthesized by electrostatic force and hydrogen bond interaction force. CMN10 achieved a favorable evaporation rate as high as 1.85 kg m− 2 h− 1 in pure water, and the corresponding evaporation efficiency could be up to 96.04%. Even if it is applied to seawater with multiple interference factors, its evaporation rate can still be 1.81 kg m− 2 h− 1. The superior seawater evaporation activity origins from the promoted separation of photoexcited charges and photothermal conversion by the synergy of Ni chain and MXene, as well as the water transport channel supported by the 3D structure frame of CNF. Most importantly, CMN aerogel can maintain water vapor evaporation rates above 1.73 kg m− 2 h− 1 under extreme conditions such as acidic (pH 2) and alkaline (pH 12) conditions. In addition, various major ions, heavy metals and organic pollutants in seawater can be rejected by CMN10 during desalination, and the rejection rates can reach more than 99.69%, ensuring the purity of water resources after treatment. This work shows the great potential of CMN aerogel as a high-efficiency solar evaporator and low-cost photothermal conversion material. Cellulose nanofiber (CNF)/MXene/Ni chain (CMN) aerogels demonstrated high evaporation of water from sea water.
These experiments were to investigate the variations of rye on forage quality, productivity and β-carotene concentration affected by maturity in Pyeongchang region. Limited information are available about how forage quality and β-carotene content are affected by various factors. Samples were collected from rye harvested every 5 days, from April 25 to May 31 (April 25, April 30, May 4, May 9, May 15, May 21, May 25 and May 31). Dry matter (DM) content, plant height, DM yield and total digestible nutrient (TDN) yield increased continuously with the progressed maturity. However, crude protein (CP) content, in vitro dry matter digestibility (IVDMD) and relative feed value (RFV) decreased markedly with the delay of harvesting, while TDN content decreased from April 25 till May 15, then followed by a stable fluctuation. Conversely, acid detergent fiber (ADF) and neutral detergent fiber (NDF) value increased and then fluctuated slightly after blooming stage. For quality of plant parts, stem contained the lowest CP content and RFV value, and the highest ADF and NDF contents compared with other parts, while the grain showed the higher CP, IVDMD, RFV and lower fiber contents than others. With the plant matured, leaf proportion decreased while stem and grain proportion increased, and feed value of all the three parts decreased till blooming stage and followed by a stable phase. β-carotene concentration showed its highest on jointing stage, and then fell down sharply on the sequential stages. In conclusion, harvest around May 15 (blooming) is proper for forage rye if directly consumed by livestock as green chop in Pyeongchang under the consideration of both nutritive yield and forage quality.
This study was conducted to investigate the effect of whole crop rice based TMR on the meat quality of Korean Native Cattle (Hanwoo). Sixteen Hanwoo steers (average 8 months old) were divided into the control group (commercially marketed TMR) and the WCR-TMR group (whole crop rice based TMR). Feeding trials were carried out up to 30 months of age, and after slaughter, the strip loin were collected and analyzed for meat quality. There were no significant differences in proximate compositions of Hanwoo (P>0.05), and crude protein, crude fat and crude ash were 19.51∼20.23 %, 11.53∼11.35 % and 1.10∼1.12 %, respectively. There was no significant difference in water holding capacity and cooking loss between treatments (P>0.05), but it was slightly lower in the control group. Among the various functional components in meat, β-carotene was not detected, but α-tocopherol was significantly higher in WCR-TMR group and vitamin A content in control (P<0.05). The a*-value in the meat color index decreased significantly with longer storage period in the control group, whereas the WCR-TMR fed group showed no significant difference (P>0.05) according to the storage period. There were no difference between the treatments in the TBARS (2-Thiobarbituric acid reactive substances) value used as an indicator of lipid oxidation and in fatty acid content. But the control group had high myristic acid content, whereas the WCR-TMR supplemented group showed higher oleic acid and linoleic acid content. In conclusion, feeding of WCR based-TMR increased the α-tocopherol content, which is a functional ingredient in meat, and the other components were not significantly different from the control. Therefore, it was judged that there was no significant difference between WCR based and conventional TMR in meat quality characteristics.
This experiment was conducted to investigate the effect of whole crop rice (WCR) based TMR on growth performance and carcass characteristics of Hanwoo steers. WCR “Yeongwoo”was harvested at yellow ripen stage and ensiled for 60 days. The crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), in vitro dry matter digestibility (IVDMD) and total digestible nutrient (TDN) content was 8.4 %, 28.0 %, 53.8 %, 72.4 % and 66.8 %, respectively. For silage quality, pH was 4.37 and lactic and butyric acid content were 2.84 and 0.04 % in DM. Sixteen Hanwoo steers (8-mon-old) were allocated into either a control (commercial TMR) and WCR-TMR (WCR-based TMR) group. The TMR were fed according to the feeding stage phase: growing (Initiate∼14 month), early fattening (15 month∼21 month) and late fattening (22 month∼30 month). The body weight of control group increased (P<0.05) until early fattening stage, but late growing stage of WCR-TMR group was higher than that of control (P<0.05). Average daily gain (ADG) was significantly greater (P<0.05) in WCR-TMR group (total 0.78 kg/head) compared to control (total 0.66 kg/head) except for late fattening stage. The marketing weight and carcass weight were higher in WCR-TMR group (726 vs 765 kg; 417.8 vs 450.4 kg). The back fat thickness (11.75 vs 13.00 mm), Longissimus dorsi area (88.00 vs 89.88 ㎠) and yield index (65.87 vs 64.30) were not different between the two groups (P>0.05) and also no difference in meat yield grade (A : B : C = 2 : 4 : 2). Marbling score (4.00 vs 4.13), meat color (4.75 vs 4.75), fat color (3.13 vs 2.88), texture (1.25 vs 1.50) and maturity (2.00 vs 2.00) were not significant difference between the two groups and meat quality grade (1++:1+:1:2:3=0:2:4:2:0) was also not different. In conclusion, TMR feeding based on WCR silage showed superiority in carcass yield and ADG compared to control TMR. It is considered that the use of WCR for feed is a necessary option for the substitution of the imported forages and the government's policy for rice production adjustment.
Nanostructured high strength metastable Al-, Mg- and Ti-based alloys containing different amorphous, quasicrystalline and nanocrystalline phases are synthesized by non-equilibrium processing techniques. Such alloys can be prepared by quenching from the melt or by powder metallurgy techniques. This paper focuses on one hand on mechanically alloyed and ball milled powders containing different volume fractions of amorphous or nano-(quasi)crystalline phases, consolidated bulk specimens and, on the other hand. on cast specimens containing different constituent phases with different length-scale. As one example. - based metallic glass matrix composites are produced by mechanical alloying of elemental powder mixtures containing up to 30 vol.% particles. The comparison with the particle-free metallic glass reveals that the nanosized second phase oxide particles do not significantly affect the glass-forming ability upon mechanical alloying despite some limited particle dissolution. A supercooled liquid region with an extension of about 50 K can be maintained in the presence of the oxides. The distinct viscosity decrease in the supercooled liquid regime allows to consolidate the powders into bulk samples by uniaxial hot pressing. The additions increase the mechanical strength of the composites compared to the metallic glass. The second example deals with Al-Mn-Ce and Al-Cu-Fe composites with quasicrystalline particles as reinforcements, which are prepared by quenching from the melt and by powder metallurgy. (x =5,6,7) melt-spun ribbons containing a major quasicrystalline phase coexisting with an Al-matrix on a nanometer scale are pulverized by ball milling. The powders are consolidated by hot extrusion. Grain growth during consolidation causes the formation of a micrometer-scale microstructure. Mechanical alloying of leads to single-phase quasicrystalline powders. which are blended with different volume fractions of pure Al-powder and hot extruded forming (x = 40,50,60,80) micrometer-scale composites. Compression test data reveal a high yield strength of 700 MPa and a ductility of 5% for than the Al-Mn-Ce bulk samples. The strength level of the Al-Cu-Fe alloys is 550 MPa significantly lower. By the addition of different amounts of aluminum, the mechanical properties can be tuned to a wide range. Finally, a bulk metallic glass-forming Ti-Cu-Ni-Sn alloy with in situ formed composite microstructure prepared by both centrifugal and injection casting presents more than 6% plastic strain under compressive stress at room temperature. The in situ formed composite contains dendritic hcp Ti solid solution precipitates and a few -(Cu, Sn) grains dispersed in a glassy matrix. The composite micro- structure can avoid the development of the highly localized shear bands typical for the room temperature defor-mation of monolithic glasses. Instead, widely developed shear bands with evident protuberance are observed. resulting in significant yielding and homogeneous plastic deformation over the entire sample.
Background : Invitro antioxidant activity, polyphenol and flavonoid aglycone contents in black and green tea products of balloon flower leaves were investigated to provide valuable information for the further development and utilization of resources of Platycodon grandiflorum. Methods and Results : Flavonoid aglycone contents were investigated using HPLC (SHIMADZU, Japan) with a hypersil ODS column (125 mm × 4 mm, 5-μm particle, HP). DPPH and ABTS radical scavenging activities were measured by method of Lee & Lee (2004) with slight modification. Antioxidant activity, polyphenol and flavonoid contents in green tea were significantly higher than these in black tea. PC analysis indicated that first principal components explained 79.9% of the total variability for five traits investigated. PC2 explained 19.7% of the variation. Conclusion : It can be concluded from these results that these characteristics can reveal the active compound variation of black and green tea products of balloon flower leaves. These results provide scientific evidence for the utilization of balloon flower leaves.