Maleic Anhydride Coating for Strontium Aluminate-Based Phosphors

2009 ◽  
Vol 79-82 ◽  
pp. 807-810
Author(s):  
Sheng Fei Yu

Strontium aluminate-based phosphors SrAl2O4:Eu2+,Dy3+ (SAO-ED) are coated directly by the interfacial coordination chemistry method with maleic anhydride to prevent their hydrolysis in moist air. SEM, XPS, TG and DSC methods are used to characterize the coating. The results showed SAO-ED phosphors coordinated with maleic anhydride by the coordination bond and . The introduction of maleic anhydride doesn’t change the excitation and emission spectra of SAO-ED phosphors, which is proved by the photoluminescence measurement. The SAO-ED phosphor coated with 30 wt. % maleic anhydride has higher water-resistance at the cost of a minor loss of persistent phosphorescence than that of SAO-ED phosphor.

1987 ◽  
Vol 78 (4) ◽  
pp. 269-274 ◽  
Author(s):  
T. Poodle

ABSTRACTThe Scottish Hydrometric Network consists of a number of river gauging stations which have been located at sites considered suitable to provide long term flow records. Economic recession has placed some stress on the gauging programme, and has given rise to extensive closures of gauging stations in England and, to a minor extent so far, in Scotland. The way in which the network became established provides a mixture of strengths and weaknesses which could have unpredictable consequences in an adverse economic climate. Changing technology provides some opportunity to reduce the cost of data acquisition and improve the deployment of manpower, while maintaining data standards. In these changing circumstances, particularly with extensive use of computer systems, it is important that standards are established for data returned to the Water Archive and that the network is not allowed to degenerate by default.


2021 ◽  
Vol 889 ◽  
pp. 21-26
Author(s):  
Yeng Fong Shih ◽  
Jia Yi Xu ◽  
Nian Yi Wu ◽  
Yu Ting Chiu ◽  
Hui Ming Yu ◽  
...  

Bitter tea oil meal (BTOM) is the main waste from the production of bitter tea oil which is squeezed from bitter tea seeds. The purpose of this study is to reuse the BTOM as an additive of the polylactic acid (PLA) to prepare eco-friendly composites. The effects of the addition of BTOM and maleic anhydride grafted polybutylene succinate (MAPBS) on the properties of PLA were investigated. The addition of MAPBS is mainly to increase the toughness of the PLA, and to increase the compatibility between BTOM and PLA. The experimental results show that the compatibility of PLA and BTOM and impact resistance of the composites can be improved by addition of MAPBS. The composite with 5% BTOM and 8% MAPBS exhibited the best tensile strength. In addition, the composite with 5% BTOM and 5% MAPBS has the best impact strength. It was found that the addition of BTOM and MAPBS can promote the crystallization of PLA. Moreover, the addition of BTOM not only can reduce the usage of PLA and the cost of the materials, but also reuse and reduce the waste from food industry.


Aerospace ◽  
2003 ◽  
Author(s):  
Paul W. Alexander ◽  
Diann Brei

It is common practice to reduce the voltage level within piezoelectric actuators by utilizing multiple layers, typically bonded together. Unfortunately, this has a tendency to result in device failure due to delamination. For example, with benders the typical lifetime is 105 to 106 cycles, limiting its use in practical applications. This poses an interesting design tradeoff: the stroke is increased due to sharper gradients between material layers; however, the higher gradients lead to high stress concentrations at those interfaces. One approach to reducing these stresses is to grade the material properties through a monolithic piece of piezoceramic so that no interfaces or bonding elements exist, but this comes at the cost of stroke. This paper explores the design tradeoff inherent to monolithic functionally graded piezoelectrics. An analytical free-displacement model for a monolithic piezoceramic beam with a generic gradient is derived. Key to this is the inclusion of the complex electric field distribution which rises from the non-homogeneous material properties. This model is used along with finite element models to examine the effect of continuous linear and stepwise material gradients on the displacement performance as well as the stress levels. The study shows that using monolithic functionally graded piezocermics can significantly reduce the stresses with only a minor impact on the device stroke.


2019 ◽  
Author(s):  
Sam Ronan Finnegan ◽  
Leslie Nitsche ◽  
Matteo Mondani ◽  
M Florencia Camus ◽  
Kevin Fowler ◽  
...  

AbstractMale mate preferences have been demonstrated across a range of species, including the Malaysian stalk-eyed fly, Teleopsis dalmanni. This species is subject to sex-ratio (SR), an X-linked male meiotic driver, which causes the dysfunction of Y-sperm and the production of all-female broods. While there has been work considering female avoidance of meiotic drive males, the mating decisions of drive-bearing males have not been considered previously. Drive males may be less able to bear the cost of choice as SR is associated with a low-frequency inversion that causes reduced organismal fitness. Drive males may also experience weaker selection for preference maintenance if they are avoided by females. Using binary choice trials, across two experiments, we confirmed male preference for large (fecund) females but found no evidence that the strength of male preference differs between drive and standard males. We showed that large eyespan males displayed strong preference for large females, whereas small eyespan males showed no preference. Taken together, these results suggest that, even though meiotic drive is associated with lower genetic quality, it does not directly interfere with male mate preference among available females. However, as drive males tend to have smaller eyespan (albeit only ~5% on average), this will to a minor extent weaken their strength of preference.


2012 ◽  
Vol 16 (6) ◽  
pp. 463-480 ◽  
Author(s):  
Michael Pearson

Abstract In the voluminous literature on historical piracy there is no convincing analysis of the actual impact of piracy on sea trade. This article attempts, in a preliminary way, such an analysis. Fragmentary data from the early modern Indian Ocean suggests that the cost of piracy was a minor imposition as compared with many other charges and dangers, some of them predictable, others not.


Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 683-690 ◽  
Author(s):  
G. Abbasnejad ◽  
H. M. Daniali ◽  
A. Fathi

SUMMARYThe main goal of this paper is the design of 4PUS+1PS parallel manipulator, using an optimization problem that takes into accounts the characteristics of the workspace and dexterity. The optimization problem is formulated considering constraints on actuated and passive joint limits. A comparison between quantum particle swarm Optimization (QPSO) and PSO is developed. Two numerical examples are presented, which reveal the advantages of QPSO to PSO. Moreover, it is shown that by introducing the dexterity index as a quality measure throughout the workspace, the parallel manipulator is improved at the cost of a minor reduction in its workspace.


Author(s):  
Khaldia abdelkader benyamina

I have tried through my studies to appreciate the efforts of researchers who dealt with the issue of divorce, summarize the sum of their ideas in it or more remind us of our youth and those concerned with the danger of divorce, which has become a strange phenomenon, and an unusual event razed the body of our Muslim society or nearly, despite the existence of what it organizes and limits In the Holy Quran, which emphasized the moderation and moderation in the management of human affairs and the universe, as the provisions and laws surrounded by the Koran divorce aims to maintain human relations based on housing and affection and mercy, and restrict or narrowing the circle of divorce by specifying the number Shots and staging them, and limit the causes and disobedience B who tamper with it and exceed the limits of God, and follow him by restricting and paid by the provisions of the kit and the expense of mediation mediated by divorce and made them a tool of reconciliation and treatment and review more than the tool of separation and division and destruction, without arbitrariness in the kit prolongation of , And in the expense of the husband's insolvency to spend above the cost itself, as well as that the Holy Quran was an average when equated between the parties to the marriage in the request for divorce, and fought Nchuz which disturbs her life and leads to divorce, preventive steps and stages of reform distancing the sex from The power of masculinity and the language of conflict, and remove women from humiliation and humiliation, and maintain the relationship between parents Children. The centrality of the Quran and the moderation of Islam in dealing with divorce are based on its miraculousness, which does not leave a minor or a large one except that it is counted. He did not prohibit divorce so as not to be extreme, and he did not give him absolute permission so as not to be unjust. He was between the custodian of the conditional marriage And he maintained the sanctity of the human relationship in the event of separation between the spouses. He was merciful to the man and he is marrying him, and he is also merciful to him, and he is authorized to divorce him, and he is merciful and he hates this divorce.    


Author(s):  
Matthew A. Thompson ◽  
Amir Mohajeri ◽  
Amin Mirkouei

Abstract Nitrogen Trifluoride (NF3) is an inorganic compound widely used in the electronics industry for manufacturing various products, such as semiconductors, solar panels, and touch screens. However, NF3 emissions that accumulate in the atmosphere have 17,200 times the global warming potentials of CO2 over a 100-year time horizon. The abatement efficiency for NF3 is high, although some amount of NOx is generated. This study aims to provide economic and environmental impact assessments on the use of NF3. Life cycle assessment method is applied for evaluating environmental aspects. Additionally, a real case study for the Idaho semiconductor facility is used to assess the method and demonstrate the application of this study. The results show that slight reductions in abatement efficiency have dramatic impacts on mitigating greenhouse gas (GHG) emissions. Even small unplanned releases of NF3, either through mechanical failure or human error, have significant environmental impacts, and every reasonable effort should be taken to avoid such incidents. The results also indicate that the cost of abatement is the primary driver of economic impact. It is found that the considerable distance from the chemical plant in Arizona to the point of use in Idaho contributed a minor portion of GHGs associated with the use of NF3. It is also found that contaminants (e.g., SF6 and CF4) within the cylinder potentially have more substantial GHG impacts than the actual NF3, owing in part to the relative ease with which NF3 is destroyed through abatement.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 175 ◽  
Author(s):  
Shishuai Gao ◽  
Yupeng Liu ◽  
Chunpeng Wang ◽  
Fuxiang Chu ◽  
Feng Xu ◽  
...  

In this study, a lignin-based polyacid catalyst was synthesized via two steps to enhance water resistance of urea–formaldehyde (UF) resins. The first steps involved a hydroxymethylation reaction to increase the hydroxyl content in lignin. Then, hydroxymethylated lignins were reacted with maleic anhydride to form maleated lignin-based polyacids. The acid groups were expected to function as acid catalysts to catalyze the curing process of UF resin. In order to elucidate the structural variation, 3-methoxy-4-hydroxyphenylpropane as a typical guaiacol lignin structural unit was used as a model compound to observe the hydroxymethylation and the reaction with maleic anhydride analyzed by 1H and 13C NMR. After the structural analysis of synthesized lignin-based polyacid by FTIR and 13C NMR, it was used to produce UF resin as an adhesive in plywood and medium density fiberboard (MDF) production, respectively. The results showed that when the addition of lignin-based polyacid was 5% in plywood, it could effectively improve the water resistance of UF resins as compared to commercial additive NH4Cl. It also exhibited a lower formaldehyde emission. Like plywood, lignin-based catalysts used in medium density fiberboard production could not only maintain the mechanical properties, but also inhibit the water adsorption of fiberboards.


2019 ◽  
Vol 97 ◽  
pp. 02017 ◽  
Author(s):  
Evgeniy Velichko ◽  
Nikita Polkovnikov ◽  
Yuliya Sadchikova

The article deals with issues of optimizing the composition of efficient concrete increased water resistance, reducing its cost without losing or increasing its basic properties. In recent years, the most effective method of tightness to water in the construction of buried and underground structures, as opposed to the use of bituminous and other traditional materials, is a method based on the use of concrete with increased water resistance. This type of tightness to water is called “White bath” in Europe. The essence of the technology is that the role of the impervious layer is performed directly by the concrete itself. The subject of the study is the composition of self-stressing concrete, which has a high density and fastness to water, but a high price compared to the concrete on Portland cement, which limits its wide application. The aim of the study is the development and optimization of the composition or stressing concrete with desired properties using a variety of mineral and polymeric additives to reduce the cost of the finished product while maintaining or improving the significant operational indicators.


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