scholarly journals CARACTERIZAÇÃO TECNOLÓGICA DA MADEIRA DE Trattinnickia burserifolia Mart. SUBMETIDA AO TRATAMENTO DE ACETILAÇÃO

Nativa ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 420
Author(s):  
Gustavo Gomes Figueiredo ◽  
Andressa Thaís Porazzi Bortolini ◽  
Diego Martins Stangerlin ◽  
Elisangela Pariz ◽  
Denise Dos Santos Oliveira

O tratamento de acetilação é um processo químico de modificação da madeira que visa melhorar algumas das suas propriedades, agregando maior valor ao produto final. Deste modo, objetivou-se avaliar as propriedades físicas, mecânicas e biológicas da madeira acetilada de Trattinnickia burserifolia Mart. (amescla). Os tratamentos de acetilação efetuaram-se por imersão em anidrido acético durante dois períodos de tempo – 3 e 6 horas – com temperatura constante de 80ºC. O tempo de tratamento de acetilação influenciou significativamente no ganho de massa da madeira, sendo verificados os maiores valores para o tratamento de 6 horas. Por outro lado, a massa específica não foi influenciada significativamente pelo tempo de tratamento. Na absorção em água e retratibilidade volumétrica, após o tempo de 2 horas, 24 horas e saturação total, o tratamento de 6 horas foi o mais eficaz. Na propriedade mecânica de dureza Rockwell, evidenciou-se que a madeira tratada apresentou maiores valores de resistência mecânica. A acetilação da madeira de amescla proporcionou aumento da resistência biológica ao ataque de cupins xilófagos.Palavras-chave: modificação química; qualidade da madeira; madeira tropical. TECHNOLOGICAL CHARACTERIZATION OF AMESCLA WOOD SUBMITTED TO ACETYLATION TREATMENT ABSTRACT: The acetylation treatment is a chemical process of wood modification that aims to improve some of its properties, adding more value for the final product. In this way, this study aimed to evaluate the physical, mechanical and biological properties of the amescla wood. The acetylation treatment was performed by immersion in acetic anhydride over two time periods – 3 and 6 hours – with a constant temperature of 80°C. The time period of acetylation influenced significantly in the WPG (weight percentual gain) of the wood, and the highest values were noticed for the 6 hours treatment. On the other hand, the density was not significantly influenced by the treatment time. In water absorption and volumetric swelling after 2 hours, 24 hours and full saturation, the 6 hours treatment was most effective. The mechanical property of Rockwell hardness demonstrated that the treated wood had higher mechanical strength values. The acetylation of amescla wood has provided increased biological resistance to xylophagous termites.Keywords: chemical modification; wood quality; tropical wood.

2021 ◽  
pp. 2150166
Author(s):  
J. T. Wang ◽  
Jiangdi Fan ◽  
Aaron X. Kan

In this paper, we have studied the Maxwell radiation from the electron orbiting the nucleus in an atom such as hydrogen atom. The orbiting electron is thought as two oscillating dipoles: one on [Formula: see text]-axis and the other on [Formula: see text]-axis with the same frequency. We have derived the electromagnetic wave and calculated powers of the radiation from these two oscillating dipoles, and then determined the time period it takes for the electron to change its energy levels from [Formula: see text] to [Formula: see text] due to the Maxwell radiation. Compared the time period due to the Maxwell radiation with the time period from the uncertainty principle, it is found that the two time periods are different from each other by about nine orders of magnitude. So, we are led to believe that the Maxwell theory could not be used in the quantum photo emission by the electron in an atom. Thus, we suggest that the quantum photo emission by the electron in an atom may be photon tunneling from the electron [Formula: see text] in an atom.


2021 ◽  
Author(s):  
Mariel Maugeri Suarez ◽  
Marianela Soledad Rodriguez ◽  
Nicolas Bejerman ◽  
Irma Graciela Laguna ◽  
Patricia Rodriguez Pardina

Soybean mosaic virus (SMV) causes systemic infections in soybean plants, leading to chlorotic mosaic and producing significant yield losses. The virus is widely distributed in all soybean production areas in the world. In Argentina, three geographical isolates were identified: Marcos Juarez (MJ), Manfredi (M), and North Western Argentina (NOA), and another isolate named "Planta Vinosa" (PV), which causes severe necrosis symptoms in some cultivars. Here, the biological, molecular and physiological characterization of these isolates was performed for the first time. Three of the four isolates showed a low genetic divergence in the evaluated genes (P1, CI and CP). Although SMV-NOA and SMV-PV had high homology at the sequence level, they showed wide differences in pathogenicity, seed mottling and the ability of transmission by seeds or aphids, as well as in physiological effects. SMV-NOA caused early alterations (before symptom appearance, BS) in quenching of PSII and MDA content in leaves with respect to the other isolates. After the appearance of macroscopic symptoms (late symptoms, LS), SMV-M caused a significant increase in the content of MDA, total soluble sugars, and starch with respect to the other isolates. Thus, early alterations of quenching of PSII and soluble sugars might have an impact on late viral symptoms. Likewise, SMV-MJ developed more severe symptoms in the susceptible Davis cultivar than in DM 4800. Therefore, our results show differences in genome, biological properties and physiological effects among SMV isolates as well as different interactions of SMV-MJ with two soybean cultivars.


2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 217-218
Author(s):  
Morgan T Thayer ◽  
Jim L Nelssen ◽  
Austin J Langemeier ◽  
Jodi M Morton ◽  
John M Gonzalez ◽  
...  

Abstract A total of 69 sows (DNA Line 200 × 400) and their progeny were used to determine if feeding a combination of vitamin D3 and 25(OH)D3 influences neonatal and sow vitamin D3 status. Within 3 d of breeding, sows were allotted to 1 of 3 dietary treatments fortified with 1,500 IU/kg vitamin D3 (CON), 500 IU/kg vitamin D3 + 25 μg/kg 25(OH)D3 (DL), or 1,500 IU/kg vitamin D3 + 50 μg/kg 25(OH)D3 (DH). There were treatment × time interactions for sow and pig serum metabolites (P < 0.001). Therefore, treatment means were compared within time period. At all time periods, sow serum 25(OH)D3 concentrations differed for all treatments with the magnitude of difference largest at weaning (P < 0.011), where serum 25(OH)D3 concentration was always the greatest when sows were fed the DH diet. At birth, piglets from DH fed sows had greater serum 25(OH)D3 concentrations than piglets from sows fed the DL treatment (P = 0.003), with piglets from sows fed CON treatment not differing from either (P > 0.061). At weaning, serum concentrations of 25(OH)D3 in piglets from all sow treatments were different (P < 0.001), with the greatest concentration in piglets from DH sows, followed by CON, and followed by DL. There were no treatment × time interactions for any of the metabolites measured in milk and no main effects for 24,25(OH)2D3 concentration (P > 0.068). Colostrum collected within 12 h of parturition contained less (P = 0.001) 25(OH)D3 than milk collected on d 21 of lactation. Regardless of time, concentrations of 25(OH)D3 in milk were different (P < 0.030), with the largest 25(OH)D3 concentration from DH fed sows, followed by DL and then CON. In conclusion, combining vitamin D3 and 25(OH)D3 in the maternal diet improves the vitamin D3 status of the dam and progeny.


Author(s):  
J. I. Bennetch

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.


Planta Medica ◽  
2014 ◽  
Vol 80 (16) ◽  
Author(s):  
CA Aguiar ◽  
AM Ferreira ◽  
R Oliveira ◽  
F Baltazar ◽  
A Cunha

1982 ◽  
Vol 47 (03) ◽  
pp. 197-202 ◽  
Author(s):  
Kurt Huber ◽  
Johannes Kirchheimer ◽  
Bernd R Binder

SummaryUrokinase (UK) could be purified to apparent homogeneity starting from crude urine by sequential adsorption and elution of the enzyme to gelatine-Sepharose and agmatine-Sepharose followed by gel filtration on Sephadex G-150. The purified product exhibited characteristics of the high molecular weight urokinase (HMW-UK) but did contain two distinct entities, one of which exhibited a two chain structure as reported for the HMW-UK while the other one exhibited an apparent single chain structure. The purification described is rapid and simple and results in an enzyme with probably no major alterations. Yields are high enough to obtain purified enzymes for characterization of UK from individual donors.


2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Kjell Hausken ◽  
Mthuli Ncube

We consider revolutions and civil war involving an incumbent, a challenger, and the population. Revolutions are classified into eight outcomes. In four outcomes incumbent repression occurs (viewed as providing sub-threshold benefits such as public goods to the population). Accommodation occurs in the other four outcomes (benefits provision above a threshold). The incumbent and challenger fight each other. The incumbent may win and retain power or else lose, thereby causing standoff or coalition. In a standoff, which is costly, no one backs down and uncertainty exists about who is in power. In a coalition, which is less costly, the incumbent and challenger cooperate, compromise, and negotiate their differences. If the population successfully revolts against the incumbent, the challenger replaces the incumbent. Eighty-seven revolutions during 1961–2011, including the recent Arab spring revolutions, are classified into the eight outcomes. When repressive, the incumbent loses 46 revolutions, remains in power through 21 revolutions, and builds a coalition after 12 revolutions. When accommodative, the incumbent loses seven revolutions and builds a coalition after one revolution. The 87 revolutions are classified across geographic regions and by time-period.


Genetics ◽  
2000 ◽  
Vol 154 (1) ◽  
pp. 121-132
Author(s):  
Zhen Hu ◽  
Yingzi Yue ◽  
Hua Jiang ◽  
Bin Zhang ◽  
Peter W Sherwood ◽  
...  

Abstract Expression of the MAL genes required for maltose fermentation in Saccharomyces cerevisiae is induced by maltose and repressed by glucose. Maltose-inducible regulation requires maltose permease and the MAL-activator protein, a DNA-binding transcription factor encoded by MAL63 and its homologues at the other MAL loci. Previously, we showed that the Mig1 repressor mediates glucose repression of MAL gene expression. Glucose also blocks MAL-activator-mediated maltose induction through a Mig1p-independent mechanism that we refer to as glucose inhibition. Here we report the characterization of this process. Our results indicate that glucose inhibition is also Mig2p independent. Moreover, we show that neither overexpression of the MAL-activator nor elimination of inducer exclusion is sufficient to relieve glucose inhibition, suggesting that glucose acts to inhibit induction by affecting maltose sensing and/or signaling. The glucose inhibition pathway requires HXK2, REG1, and GSF1 and appears to overlap upstream with the glucose repression pathway. The likely target of glucose inhibition is Snf1 protein kinase. Evidence is presented indicating that, in addition to its role in the inactivation of Mig1p, Snf1p is required post-transcriptionally for the synthesis of maltose permease whose function is essential for maltose induction.


Mathematics ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 116
Author(s):  
Qi Liu ◽  
Yongjin Li

In this paper, we will introduce a new geometric constant LYJ(λ,μ,X) based on an equivalent characterization of inner product space, which was proposed by Moslehian and Rassias. We first discuss some equivalent forms of the proposed constant. Next, a characterization of uniformly non-square is given. Moreover, some sufficient conditions which imply weak normal structure are presented. Finally, we obtain some relationship between the other well-known geometric constants and LYJ(λ,μ,X). Also, this new coefficient is computed for X being concrete space.


BMC Zoology ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Ansa E. Cobham ◽  
Christen K. Mirth

Abstract Background Organisms show an incredibly diverse array of body and organ shapes that are both unique to their taxon and important for adapting to their environment. Achieving these specific shapes involves coordinating the many processes that transform single cells into complex organs, and regulating their growth so that they can function within a fully-formed body. Main text Conceptually, body and organ shape can be separated in two categories, although in practice these categories need not be mutually exclusive. Body shape results from the extent to which organs, or parts of organs, grow relative to each other. The patterns of relative organ size are characterized using allometry. Organ shape, on the other hand, is defined as the geometric features of an organ’s component parts excluding its size. Characterization of organ shape is frequently described by the relative position of homologous features, known as landmarks, distributed throughout the organ. These descriptions fall into the domain of geometric morphometrics. Conclusion In this review, we discuss the methods of characterizing body and organ shape, the developmental programs thought to underlie each, highlight when and how the mechanisms regulating body and organ shape might overlap, and provide our perspective on future avenues of research.


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