Substitution Of Use Research Articles

Multiferroic properties of BiFeO3 thin films with Ce substitution

In this study, we investigated the crystalline structure, ferroelectricity, leakage current density, magnetic, and nanomechanical properties of BiFeO3 (BFO) films with Ce substitution. Bi1-xCexFeO3 (BCFO) films with x = 0.00, 0.03, 0.06, 0.09, and 0.15 were deposited on glass substrates by using pulsed laser deposition. The experimental results showed that the BCFO films mainly composed the perovskite phase. The structure changed from rhombohedral when x = 0.00 to pseudo-cubic when x = 0.03, and pseudo-cubic phase coexisted with an additional Bi2Fe4O9 phase when x = 0.06–0.09. The BCFO films exhibited improved ferroelectricity and desirable magnetic characteristics. The remanent polarization (2Pr) increased significantly with the Ce concentration, reaching 189.3 μC/cm2 and 100.0 μC/cm2 when x = 0.03 and x = 0.06, respectively, but decreasing at higher Ce contents. The BCFO film with x = 0.03 had a remarkable 2Pr value of 189 μC/cm2 after 108 cycles due to the high (110) texture, fine microstructure, and flat interface resulting in strong anti-fatigue properties. The leakage mechanisms in the BCFO films were also examined. The films exhibited enhanced saturation magnetization (Ms) values ranging from 3.8 to 10.0 emu/cm3, which were attributed to suppression of the spiral spin configuration and the larger magnetic moment associated with the Ce3+ ion. The nanomechanical characteristics of the BCFO films, such as hardness, were significantly influenced by the grain size and phase composition. These findings provide valuable insights into enhancement of the multiferroic properties of BFO polycrystalline films through Ce substitution for use in various applications.

Total fishmeal replacement by defatted Tenebrio molitor larvae meal induces alterations in intermediary metabolism of European sea bass (Dicentrarchus labrax).

The replacement of fishmeal (FM) by insect meal (IM) in aquafeed formulation has been thoroughly studied lately, but little is known about their impact on nutrient metabolism of fish. This study evaluated the impact not only of partial but also total FM replacement by IM on intermediary metabolism of European sea bass (Dicentrarchus labrax). A fishmeal-based diet was used as a control (CTRL) and two other diets were formulated to include 20% and 40% of defatted Tenebrio molitor larvae meal (dTM), replacing 50% (TM50) and 100% (TM100) of fishmeal (FM), respectively. After a 16-week feeding trial, a multidisciplinary approach including assessment of histological, biochemical, molecular, and enzymatic parameters was adopted to investigate hepatic and plasmatic responses to the different dietary formulations. The results obtained demonstrated that dTM can be successfully used to replace 50% of FM in diets for European sea bass, without adversely affecting liver health or intermediary metabolism of nutrients. As for TM100, although no signs of steatosis were observed in the liver, the activity of glycolytic and lipogenic genes and enzymes increased when compared to CTRL diet (P < 0.05), resulting in higher levels of plasmatic non-esterified fatty acids and triacylglycerides (P < 0.05), which in the long-term may compromise fish health, thus precluding such a high degree of substitution for use in practical diets for European sea bass.

Propriedades físicas de um Argissolo após 17 anos de florestamento com Eucalyptus spp.

A expressiva expansão do setor florestal no Brasil tem dado evidencia a estudos que direcionam suas ações de investigação para a preservação e utilização racional dos recursos naturais. A pesquisa tem demonstrado que mudanças no uso do solo, alteram as suas condições pedoambientais. Sendo assim, o presente estudo teve como objetivo principal investigar ações antrópicas de longa duração sobre área do bioma Pampa no Rio Grande do Sul: Efeito nos atributos físicos de solo com substituição do uso sob campo para o uso do solo com florestamento comercial de Eucalyptus spp. Amostras de um Argissolo Vermelho Distrófico foram coletadas em horto florestal, em triplicata e em cinco profundidades e também foi coletado um solo de controle, vegetado com campo natural. Não houve alteração na distribuição granulométrica do solo. Após 17 anos de florestamento foi observado um incremento no teor de hematita nos solos da floresta e rizosfera da floresta, aumento nos valores da suscetibilidade magnética e diminuição da área superficial específica das partículas em profundidade.

Weed Growth Properties of Amaranthus Retroflexus, Echinochloa Crus-Galli and Setaria Viridis as Influenced by Shifts in the Maize Cropping Season

Climate change is predicted to result in rising temperatures which directly influence weed growth. Moreover, alterations in farming practice and variations in the timing of maize sowing affect weeds also indirectly. The main objective of this study was to establish the methodological concept of time-for-climate substitution for use in applied research. For this purpose, a semi-field experiment was conducted with the three important maize weeds Amaranthus retroflexus, Echinochloa crus-galli and Setaria viridis, which were cropped together with maize. In four treatments sowing of weeds was delayed in order to use naturally raising temperatures. This study focusses on late weed growth properties such as tillers, panicles, seeds and biomass as they allow important demographic conclusions for long-term weed population development. Over the season, temperature was continuously monitored with data loggers and growing degree days were calculated in order to relate the late growth properties to the climatic conditions the weeds experienced during early growth in the four treatments. The results from this study suggest that the tested weeds may benefit in two ways: (1) From warmer conditions during seedling emergence and early growth with enhanced vegetative growth and seed set; (2) from more growing degree days available as a result of earlier maize sowing and related extended cropping seasons. We conclude that our methodology is suitable to investigate climate change effects on weeds for applied questions. In order to limit weed growth and weed seed set under future conditions, management measures such as herbicide treatments at later growth stages and earlier harvest of maize should be explored. Furthermore, we suggest that functional relationships between late weed growth properties such as fecundity and different climatic conditions can be used to improve the accuracy of demographic and bioclimatic models.

Co-Electrodeposition of Bilirubin Oxidase with Redox Polymer through Ligand Substitution for Use as an Oxygen Reduction Cathode

The water soluble redox polymer, poly(N-vinylimidazole) complexed with Os(4,4'-dichloro-2,2'-bipyridine)<TEX>$_2Cl]^+$</TEX> (PVI-[Os(dCl-bpy)<TEX>$_2Cl]^+$</TEX>), was electrodeposited on the surface of a glassy carbon electrode by applying cycles of alternating square wave potentials between 0.2 V (2 s) and 0.7 V (2 s) to the electrode in a solution containing the redox polymer. The coordinating anionic ligand, <TEX>$Cl^-$</TEX> of the osmium complex, became labile in the reduced state of the complex and was substituted by the imidazole of the PVI chain. The ligand substitution reactions resulted in crosslinking between the PVI chains, which made the redox polymer water insoluble and caused it to be deposited on the electrode surface. The deposited film was still electrically conducting and the continuous electrodeposition of the redox polymer was possible. When cycles of square wave potentials were applied to the electrode in a solution of bilirubin oxidase and the redox polymer, the enzyme was co-electrodeposited with the redox polymer, because the enzymes could be bound to the metal complexes through the ligand exchange reactions. The electrode with the film of the PVI-[Os(dCl-bpy)<TEX>$_2Cl]^+$</TEX> redox polymer and the co-electrodeposited bilirubin oxidase was employed for the reduction of <TEX>$O_2$</TEX> and a large increase of the currents was observed due to the electrocatalytic <TEX>$O_2$</TEX> reduction with a half wave potential at 0.42 V vs. Ag/AgCl.

Iodopyridine-for-iodobenzene substitution for use with low molecular weight radiopharmaceuticals: application to m-iodobenzylguanidine.

Substituting a pyridine ring for a benzene ring in the acylation agent N-succinimidyl 3-iodobenzoate has resulted in a useful approach for the radiohalogenation of monoclonal antibodies, peptides, and labeled biotin conjugates. It was hypothesized that such a substitution in m-iodobenzylguanidine (MIBG), a radiotracer used in the detection and treatment of neuroendocrine tumors, might result in an analogue with more rapid normal tissue clearance, thereby facilitating its use for tumor therapy. For the preparation of this analogue, 3-guanidinomethyl-5-iodopyridine (GMIP; 9b), the silicon precursor 4 was synthesized starting from 5-bromonicotinic acid. Attempts to convert 4 to 9b under various conditions were not successful. Radioiodinated 9b could be prepared by the iododestannylation of the tin precursor 8 in 65-70% radiochemical yield. A number of in vitro, in vivo, and ex vivo studies showed that pyridine-for-benzene substitution in MIBG yielded a compound that no longer was taken up by the uptake-1 pathway.

Film radiometer based on electrical substitution for use in photometric measurements

The design of a nonselective radiometer that functions on the basis of the principle of electrical substitution is described. The assembled radiometer possesses high current-voltage sensitivity on the order of 10 V/W, time constant 7 sec, and error in measurement of the emissive power at most 0.3%. It is designed for exact photometric measurements in the visible and infrared bands of the spectrum.

Substitution in Use and the Role of Usage Context in Product Category Structures

The relationship between the substitution in use approach to product-market structure and cognitive accounts of product category structures is investigated in terms of the role of product usage context. Studies 1 and 2 show that distinctive usages predict similarity judgments, whereas usage versatility predicts prototypicality. The results of a third study suggest that individual usage contexts are associated with subcategories that involve restructuring of the overall category and, as such, guide context-specific product recall. Conceptual and managerial implications of the findings are discussed.

Substitution in Use and the Role of Usage Context in Product Category Structures

Substitution in Use and the Role of Usage Context in Product Category Structures

Alcohol and illicit drug use: follow-up study of treatment admissions to DARP during 1969-1971.

The present study was based on follow-up data on 1409 persons interviewed 4 to 6 years after admission to drug treatment in the Drug Abuse Reporting Program (DARP). The admissions to DARP occurred in 1969-1971, and for most persons the follow-up data included 3 or more years after termination of DARP treatment. The study focused on variations in alcohol consumption associated with post-DARP drug use and treatment status. The results indicated that use of alcohol and non-opioid drugs (particularly marijuana) tended to be correlated, but that this was not true of opioid drugs. For a small segment of the sample, evidence suggested that substitution of use may have occurred between alcohol and opioid drugs. Also, persons with post-DARP drug treatment tended to use less alcohol than persons without treatment. Interpretations and implications of these findings are discussed.