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91.
R.R. Menezes H.G. Malzac Neto L.N.L. Santana H.L. Lira H.S. Ferreira G.A. Neves 《Journal of the European Ceramic Society》2008,28(16):3027-3039
Mineral extraction and processing industries have been cited as sources of environmental contamination and pollution. The inclusion of wastes into productive cycles represents an alternative form of restoration, which is interesting from both environmental and economic standpoints. In this work, the development of ceramic tile formulations containing kaolin processing and granite sawing wastes was investigated using the statistical design of mixture experiments methodology. Ten formulations using the raw materials, red clay, kaolin processing and granite sawing wastes, were selected and used in the mixture design. Test specimens were fired and characterized to determine their water absorption, linear firing shrinkage and modulus of rupture. Regression models were calculated, correlating the properties with the composition. The significance and validity of the models were confirmed by statistical analysis and verification experiments. The regression models were used to optimize the waste content in ceramic compositions. The results showed that formulations containing up to 62% of waste could be used in the production of ceramic tiles. 相似文献
92.
Elena Laukhina Victor Lebedev Vladimir Laukhin Angel Pérez del Pino Elsa B. Lopes Ana I.S. Neves Dulce Belo Manuel Almeida Jaume Veciana Concepció Rovira 《Organic Electronics》2012,13(5):894-898
The paper reports all-organic strain and stress sensitive films that use electrical monitoring approach. The films were prepared by self-metallizing polycarbonate films with the single component molecular conductor [Au(α-tpdt)2]0 (tpdt = 2,3-thiophenedithiolate). It was shown that [Au(α-tpdt)2]0 by its nature is able to form metallic solid material with low crystallinity. Electromechanical tests demonstrated that the developed films are strain-resistive materials with advanced elastic properties: their electrical resistance varies linearly with uniaxial elongation up to relative strain being of 1.0% that is about five times larger than that for conventional metals. The gauge factor of the films is 4.4 and stress sensitivity is 30 Ω/bar. The processing characteristics of polycarbonate films, self-metalized with a metallic [Au(α-tpdt)2]0-based layer, make them potentially useful for engineering flexible, lightweight, strain and pressure sensors. Due to electromechanical characteristics these films are suited to strain sensing applications requiring miniature strain control in a wide deformation range. 相似文献
93.
P.R. Menta L. Fernandes D. Poit M.L. Celestino V.S. Machado M.A. Ballou R.C. Neves 《Journal of dairy science》2021,104(5):5854-5866
Research exploring specific associations of markers of negative energy balance and Ca in postpartum Jersey cows with lactation performance is lacking. Our objectives were to evaluate the associations of total Ca concentration (tCa) measured at 1 through 3 d in milk (DIM) and free fatty acids (FFA), β-hydroxybutyrate (BHB), and glucose measured at 3 DIM with (1) the risk of multiparous Jersey cows being diagnosed with early-lactation diseases and culling, (2) milk production in the first 9 wk of lactation, and (3) the risk of pregnancy in the first 150 DIM. A cohort study was performed in 1 dairy herd in Texas. Multivariable Poisson regression models were built to evaluate the association of the analytes of interest with the risks of early-lactation diseases and culling in the first 60 DIM (i.e., binary outcomes). Linear mixed models were used to evaluate the association of the analytes of interest with milk production within the first 9 wk of lactation, and a Cox proportional hazard model was built to assess the risk of pregnancy within 150 DIM. A total of 380 cows were used in the final analyses. Total Ca measured at 1 through 3 DIM was not associated with the risk of metritis. Cows with increased FFA and BHB had an increased risk of being diagnosed with metritis and clinical mastitis, respectively. Increased concentrations of glucose and FFA and decreased tCa at 3 DIM were associated with an increased risk of culling. Reduced tCa concentrations at 1 DIM (≤1.84 mmol/L) and 2 DIM (≤2.04 mmol/L) were associated with increased milk production across the first 9 wk of lactation compared with tCa concentrations above those thresholds. Total Ca was not associated with milk production when assessed at 3 DIM, whereas increased FFA (≥0.37 mmol/L) and decreased glucose (≤2.96 mmol/L) at 3 DIM were associated with increased milk production. None of the metabolites measured were associated with the risk of pregnancy in the first 150 DIM. Our results demonstrate that tCa concentration assessed in the first 3 DIM show temporary associations with milk production and culling in multiparous Jersey cows. Although increased concentration of FFA assessed at 3 DIM was associated with greater milk yield, it was a detrimental factor for the risk of metritis. This study attempted to better elucidate the relationship of tCa, FFA, BHB, and glucose assessed in early postpartum with health and performance of Jersey cows. Based on this study, assessments performed at 3 DIM using tCa concentration ≤1.99 mmol/L for increased risk of early-lactation culling and FFA ≥0.43 mmol/L for increased risk of metritis could be used as starting points. More studies evaluating the dynamics of energy balance markers and tCa in postpartum Jersey cows using a greater number of herds are needed to better inform dairy consultants on critical levels for exacerbated postpartum negative energy balance and subclinical hypocalcemia for the Jersey breed. 相似文献
94.
L.F. Martins P.R. Menta L. Fernandes V.S. Machado R.C. Neves 《Journal of dairy science》2021,104(5):6113-6123
Our objectives were to perform a proof-of-concept study to assess the association of a prolonged inflammatory state (based on a continually elevated haptoglobin concentration at the end of the first week after parturition) with mineral, protein, and energy balance markers in the first 2 wk after parturition, and milk production in the first 60 d of lactation in clinically healthy cows. We conducted a cohort study in 1 herd in west Texas that was milking Jersey and Jersey–Holstein crosses. Only multiparous Jersey cows were eligible for enrollment. Cows were classified as having or not having elevated haptoglobin concentrations based on plasma concentrations evaluated on d 4 and 7 postpartum. We used median concentrations of haptoglobin in the reference population (i.e., before the exclusion of cows diagnosed with clinical diseases) as the limits for categorizing cows into 2 groups: cows with plasma haptoglobin concentrations greater than the median values on both d 4 (0.49 g/L) and 7 (0.35 g/L) had continually elevated haptoglobin (with eHp); and cows with plasma haptoglobin concentrations lower than or equal to the median values of the reference population on d 4 or 7 did not have continually elevated haptoglobin (without eHp). Next, cows with clinical diseases in the first 2 wk of the postpartum period were excluded, so that 233 cows remained for the final analyses. Evaluated outcomes were average daily milk production across the first 60 d of lactation, plasma Ca, Mg, and glucose concentrations on d 1, 2, 3, 4, 5, 7, 10, and 14 postpartum, and β-hydroxybutyrate (BHB), nonesterified fatty acids (NEFA), fructosamine, albumin, urea, and creatinine concentrations on d 3, 5, 7, 10, and 14 postpartum. Rectal temperatures measured on d 4, 7, and 10 postpartum were also analyzed. We performed statistical analyses using linear mixed models while accounting for the repeated effect of sampling time (plasma analytes and rectal temperature models) and weekly milk test (milk production model). Cows with eHp had lower plasma Ca concentrations in the first 2 wk after calving, but no differences in Mg, BHB, NEFA, glucose, or rectal temperatures compared to cows without eHp. Cows with eHp had lower plasma fructosamine, albumin, and urea concentrations in a time-dependent manner. They also had lower milk production (2.3 kg/d less than cows without eHp in the first 60 DIM). Our study demonstrated that 25% of cows without clinical disorders in the first 2 wk after parturition had continually elevated haptoglobin concentrations at d 7 after parturition relative to d 4, suggestive of a prolonged, low-grade systemic inflammatory state. More observational studies are needed to more fully characterize the duration of prolonged postpartum subclinical inflammation in cows without clinical diseases, as well as its long-term effects, and to evaluate the use of other potential markers of systemic inflammation to describe this disorder. 相似文献
95.
A. Gon?alves Pronto M. Ventim Neves A. Le?o Rodrigues 《Journal of Superconductivity and Novel Magnetism》2011,24(1-2):981-985
The magnetic losses of steels used in high temperature superconducting (HTS) transformers are very important for the transformer??s efficient design and for a correct choice of operating conditions. This introduced the necessity to analyze electrical steels behaviour at low temperature in order to characterize their magnetic properties and, in particular, the magnetic losses. Three steels were chosen for this analysis: one non-oriented silicon steel and two different grain-oriented silicon steels. Several measurements of total magnetic losses were made at 77 K and 298 K and for different values of maximum magnetic induction, B max?, in order to compare the dependence between them at both temperatures. These results are presented in Pronto et al. (European Conference on Applied Superconductivity, 2009). Subsequently, measurements of hysteresis losses (DC regime) at both temperatures were also made in order to obtain all terms of magnetic losses (hysteresis, classical eddy-current losses, and excess losses). The results are presented in this paper. 相似文献
96.
Peres M Magalhães S Fellmann V Daudin B Neves AJ Alves E Lorenz K Monteiro T 《Nanoscale research letters》2011,6(1):378
Undoped self-assembled GaN quantum dots (QD) stacked in superlattices (SL) with AlN spacer layers were submitted to thermal annealing treatments. Changes in the balance between the quantum confinement, strain state of the stacked heterostructures and quantum confined Stark effect lead to the observation of GaN QD excitonic recombination above and below the bulk GaN bandgap. In Eu-implanted SL structures, the GaN QD recombination was found to be dependent on the implantation fluence. For samples implanted with high fluence, a broad emission band at 2.7 eV was tentatively assigned to the emission of large blurred GaN QD present in the damage region of the implanted SL. This emission band is absent in the SL structures implanted with lower fluence and hence lower defect level. In both cases, high energy emission bands at approx. 3.9 eV suggest the presence of smaller dots for which the photoluminescence intensity was seen to be constant with increasing temperatures. Despite the fact that different deexcitation processes occur in undoped and Eu-implanted SL structures, the excitation population mechanisms were seen to be sample-independent. Two main absorption bands with maxima at approx. 4.1 and 4.7 to 4.9 eV are responsible for the population of the optically active centres in the SL samples. 相似文献
97.
Abdelilah El‐Abbassi Marcos A. Neves Isao Kobayashi Abdellatif Hafidi Mitsutoshi Nakajima 《European Journal of Lipid Science and Technology》2013,115(2):224-231
Argan oil is well known for its nutraceutical properties. Its specific fatty acid composition and antioxidant content contribute to the stability of the oil and to its dietetic and culinary values. There is an increasing interest to use argan oil in cosmetics, pharmaceutics, and food products. However, the formulation of highly stable emulsions with prolonged shelf life is needed. In this study, argan oil‐in‐water (O/W) emulsions were prepared using microchannel (MC) emulsification process, stabilized by different non‐ionic emulsifiers. The effects of processing temperature on droplet size and size distribution were studied. Physical stability of argan O/W emulsions was also investigated by accelerated stability testing and during storage at room temperature (25 ± 2°C). Highly monodisperse argan O/W emulsions were produced at temperatures up to 70°C. The obtained emulsions were physically stable for several months at room temperature. Furthermore, emulsifier type, concentration, and temperature were the major determinants influencing the droplet size and size distribution. The results indicated that a suitable emulsifier should be selected by experimentation, since the interfacial tension and hydrophilic–lipophilic balance values were not suitable to predict the emulsifying efficiency. Practical applications: MC emulsification produces efficiently monodisperse droplets at wide range of temperatures. The findings of this work may be of great interest for both scientific and industrial purposes since highly stable and monodisperse argan oil‐in‐water emulsions were produced which can be incorporated into food, cosmetic, or pharmaceutical formulations. 相似文献
98.
Vera Lúcia Othéro de Brito Herman Jacobus Cornelis Voorwald Nasareno das Neves Ivani de S. Bott 《Journal of Materials Engineering and Performance》2001,10(3):249-257
Postweld heat treatment (PWHT) is frequently applied to steel pressure vessels, following the requirements of the ASME code
(section VIII), which establishes the parameters of the PWHT based on the thickness and chemical composition of the welded
section. This work shows the results of an analysis undertaken on a sample of ASTM A537 C1 steel subjected to qualifying welding
procedure tests including PWHT (650°C/5 h). The results obtained showed that this PWHT practice promoted a reduction in the
mechanical properties of the base metal and the heat-affected zone (HAZ). 相似文献
99.
Ismail Y.I. Friedman E.G. Neves J.L. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2001,9(6):963-973
On-chip inductance effects can be used to improve the performance of high-speed integrated circuits. Specifically, inductance improves the signal slew rate (the rise time), virtually eliminates short-circuit power consumption and reduces the area of the active devices and repeaters inserted to optimize the performance of long interconnects. These positive effects suggest the development of design strategies that benefit from on-chip inductance. An example of a clock distribution network is presented to illustrate the process in which inductance can be used to improve the performance of high-speed integrated circuits 相似文献
100.
Sílvia C. Rodrigues Renato M. S. Cardoso Patricia C. Freire Cludia F. Gomes Filipe V. Duarte Ricardo Pires das Neves Joana Simes-Correia 《International journal of molecular sciences》2021,22(18)
Umbilical cord blood (UCB) has long been seen as a rich source of naïve cells with strong regenerative potential, likely mediated by paracrine signals. More recently, small extracellular vesicles (sEV), such as exosomes, have been shown to play essential roles in cell-to-cell communication, via the transport of numerous molecules, including small RNAs. Often explored for their potential as biomarkers, sEV are now known to have regenerative and immunomodulating characteristics, particularly if isolated from stem cell-rich tissues. In this study, we aim to characterize the immunomodulating properties of umbilical cord blood mononuclear cell-derived sEV (UCB-MNC-sEV) and explore their therapeutic potential for inflammatory skin diseases. UCB-MNC-sEV were shown to shift macrophages toward an anti-inflammatory phenotype, which in turn exert paracrine effects on fibroblasts, despite previous inflammatory stimuli. Additionally, the incubation of PBMC with UCB-MNC-sEV resulted in a reduction of total CD4+ and CD8+ T-cell proliferation and cytokine release, while specifically supporting the development of regulatory T-cells (Treg), by influencing FOXP3 expression. In a 3D model of psoriatic skin, UCB-MNC-sEV reduced the expression of inflammatory and psoriatic markers IL6, IL8, CXCL10, COX2, S100A7, and DEFB4. In vivo, UCB-MNC-sEV significantly prevented or reversed acanthosis in imiquimod-induced psoriasis, and tendentially increased the number of Treg in skin, without having an overall impact on disease burden. This work provides evidence for the anti-inflammatory and tolerogenic effect of UCB-MNC-sEV, which may be harnessed for the treatment of Th17-driven inflammatory skin diseases, such as psoriasis. 相似文献