Fiber quality of upland cotton under different irrigation depths

ABSTRACTAiming to evaluate the effect of irrigation depths on fiber quality of upland cotton, an experiment was conducted from July to December 2010 in Barbalha-CE, Brazil. The treatments consisted of a factorial combination of two upland cotton cultivars (BRS Aroeira and BRS Araripe) and five irrigation depths (260.93, 418.93, 514.21, 711.81 and 894.68 mm), arranged in a split-plot design with four replicates. A line-source sprinkler irrigation system was used and irrigation depth in the control treatment was calculated according to the crop evapotranspiration. The analysed fiber quality variables were: fiber percentage, length, uniformity, short-fiber index, resistance, elongation at rupture, micronaire index, maturity, degree of yellowing, reflectance degree and count strength product (CSP) index. The irrigation depths influenced fiber length, short-fiber index, strength, micronaire index, maturity and reflectance degree. The cultivars influenced fiber percentage, length and color (degree of yellowing). The best results of fiber quality were found with irrigation depths of 514.21 and 418.93 mm for the upland cotton cultivars BRS Araripe and BRS Aroeira, respectively

Role of macronutrients in cotton production

Sound nutrition plays a key role in enhancing cotton yield. As cotton undergoes vegetative and reproductive growth at the same time, its nutritional requirements are dissimilar, compared to other field crops. Cotton is grown as an annual crop with an indeterminate growth pattern. The vegetative branching provides a potential fruiting place except under abiotic and biotic stresses. Moreover, cotton has a deep root system with low density of roots in the surface layer of soils where availability of nutrients is high. The rooting system makes cotton crop more dependent on the subsoil for nutrition. A continuous supply of nutrients is required to sustain morphogenesis. The rate of both nutrients absorption and dry matter production increases progressively during the seedling, vegetative, and fruiting periods and peaks near the end of the bloom period. Nitrogen, phosphorus, and potassium are required in large quantities and are limited in many soils. The deficiencies of macro-and micronutrients decrease plant growth and development, and consequently seed cotton yield is reduced. The deficiency of phosphorous (P), calcium (Ca), potassium (K), boron (B), magnesium (Mg), and zinc (Zn) affects fruit production in cotton than vegetative growth, while the deficiencies of nitrogen (N), sulfur (S), molybdenum (Mo), and manganese (Mn) affect equally vegetative and reproductive growth of cotton. A bevy of literature concerning the role of macronutrients in growth and development is presented in the following paragraphs. © Springer Nature Singapore Pte Ltd. 2020. All rights reserved

The Influence of Laser Irradiation Time on Fe-Si-C System Structure

The influence of different laser irradiation times on the structure of grey cast iron was studied. Mössbauer spectroscopy and X-ray diffraction were used to characterise the changes caused by laser irradiation. The composition of martensite and austenite as well as the creation of carbide phases during quenching were studied. Modelling of temperature during laser irradiation allowed differences in the influence of different laser irradiation types and times to be explained

XPS and Mössbauer Spectroscopy of LiFePO4 and LiFePO4/C Ceramics

LiFePO4 crystallizes in olivine structure. It is a mixed electronic-ionic conductor and has been proposed as an attractive cathode material for Li-ion secondary batteries. The conductivity values increased with increasing the amount of carbon in the LiFePO4/C composites [2]. It is known [3] that in this compound Fe2+ can be oxidized to Fe3+. The material has a high reversible capacity (~160 mAhg-1) and the intercalation potential for Li/Li+ is 3.5 V The redox behavior of the iron in this compound also makes it an interesting candidate for X-ray photoelectron spectroscopy (XPS) and the Mössbauer spectra study in the pure LiFePO4 and carbon containing LiFePO4/C ceramics. The LiFePO4 powders for the XPS and Mössbauer spectra study have been synthesized by solid state reaction and LiFePO4/C composites were synthesized by a sol-gel method and later sintered in argon gas.The ceramics of LiFePO4 was sintered in air. The binding energies of Fe 2p, P 2p and O 1s core level of the LiFePO4 ceramics and LiFePO4/C composite surfaces have been determined by XPS at room temperature. The analysis of Fe 2p, P 2p and O 1s core level XPS deconvolution is presented in this work. Mössbauer spectroscopy in the temperature range from 10 K to 700 K has been applied in order to determine phase transition temperatures, the Debye-Waller factor and typical ionization states of iron in compounds. Behavior of Li+ ions was evaluated in the second coordination sphere of iron based on changes in hyperfine parameters of Mössbauer spectra

XRD, Impedance, and Mössbauer Spectroscopy Study of the Li3Fe2(PO4)3+Fe2O3 Composite for Li ion Batteries

The solid electrolyte Li3Fe2(PO4)3+Fe2O3 compound has been synthesized by solid state reaction and studied by Xray powder diffraction and impedance and Mössbauer spectroscopies.The XRD showed the presence of Li3Fe2(PO4)3 of monoclinic symmetry (space group P21) and confirmed the formation of the α-Fe2O3 (hematite). Two regions of the impedance dispersion have been analyzed in terms of the fast Li+ ions transport in the grains and grain boundaries of the ceramic samples. The temperature dependences of the grain conductivity, relaxation frequency, and permittivity showed anomalies related to α–β and β–γ structural phase transitions in Li3Fe2(PO4)3. As we found that in α and γ phases the activation energy of the grain conductivity is equal to the activation energy of the relaxation frequency in grain, which can be attributed to the mobility of fast Li+ ion in grains, the concentration of charge carriers remains constant with temperature.From Mössbauer spectroscopy, it is evident that Fe ions in the whole temperature range (10–690 K) are observed only in the Fe3+ state. Two phase transitions have been detected in this temperature range in the composite—the phase transition from the antiferromagnetic state to the paramagnetic one in Li3Fe2(PO4)3 and the Morin transition in hematite at temperatures TN=29.5 K and TM=235 K, respectively