Melhoria energética do sector de soda leve conforme a nova metodologia manufacturing excellence solvay Portugal

Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica

Aprovechamiento de un residuo sólido no peligroso generado en el proceso Solvay

Tesis (Maestría en Ciencias con Especialidad en Ingeniería Ambiental) UANL

Estructura de la materia: Tema central de la Conferencia Solvay de 1913

Se analiza lo tratado en la Conferencia Solvay de 1913, que fue de gran interés para el avance de la comprensión de la estructura de la materia (estructura atómica y cristalografía)

Poëme d'amour : sept chants lyriques de de Lucien Solvay /

For voice and piano.

Die Theorie der Strahlung und der Quanten, Verhandlungen auf einer von E. Solvay einberufenen Zusammenkunft (30 Oktober bis 3 November 1911); mit einem Anhange über die Entwicklung der Quantentheorie von Herbst 1911 bis zum Summer 1913,

Translation of Théorie de rayonnement.

AB，ABA型乙丙嵌段共聚物的合成、结构及作为乙丙橡胶改性聚丙烯增容剂的研究

本文试图用Solvay型的Ziegler-Natta催化剂合成PP－EPR，PP－EPR－PP嵌段共聚物，作为乙丙橡胶（EPT）和聚丙烯（PP）的增容剂，来提高聚丙烯的抗冲击强度，并从力学性能、动态力学谱和形态等方面研究增容剂的增容效果。Ziegler-Natta催化剂能否合成乙丙嵌段共聚物是一个有争议的问题。为此，我们利用改进型的Solvay δ-TiCl_3-Et_2AlCl在已烷中加压淤浆聚合丙烯，发现在120分钟之前，聚丙烯的分子量随时间迅速增加，超过120分钟则变缓慢，并趋向于平衡。这说明催化剂活性中心上的活性链最小有120分钟的时间，若在该时间内用聚合过程中换反应单体的办法，有可能合成嵌段共聚物。乙丙嵌段共聚物形成的直接证明是利用(PP－PE)_(50)。通过气相色谱检测发现，抽真空3分钟可以保证换反应气体的纯度，因而用气相聚合可以得到各段纯净的(PP－PE)_(50)多嵌段共聚物，该嵌段的~(13)c-NMR研究表明，在35.68ppm处存在以化学键相连的长乙烯和长丙烯链的特征共振峰。PGC的研究发现，其在热裂解中产生的G碎片比PP／P混物的多，GC－MS的研究表明G碎片由含7个碳的烃组成的混合物，组分之一具有嵌段共聚物的裂解特征。对PP－EPR系列产物和PP－EPR－PP（5－60－20）用扭摆法进和动态力学分析表明，这些嵌段共聚物只在－30℃左右有一个玻璃化转变。而相应的共混物则分别在－50℃和5℃出现两个玻璃化转变，且各T_g不随组成比和共混方法而变化。这是由于嵌段共聚物中各段间化学键的作用，使各段的T_g内移，从而使较靠近的两个T_g合二为一，在动态力学谱上只表现出一个T_g。粘弹谱仪测定的结果基本上同扭摆法的结果。尽管我们尚未准确地测定出乙丙嵌段共聚物中EPR段的分子量，但我们弄清了PP段的立体构型、等规度、分子量、结晶度和EPR段的乙丙比、无规乙丙共聚物的含量、含有长序列乙烯的结晶度等结构因素。用不同段长的PP－EPR作PP／EPT共混物的增容剂，发现降低PP－EPR中PP段的分子量，三元共混物的力学性能明显升高，而增加EPR段的分子量即聚合时间，其无缺口冲击强度先增加而后又降低，说明有一个EPR段最佳长度范围。根据该现象我们提出模型并进行了解释。结晶度的规律与冲击强度的规律相同，对冲击强度提高较大的增容剂，共混物中PP的结晶度降低，但抗张性能却升高，说明增容剂在两相界面起到主价的连接作用。扭摆法和粘弹谱仪测定的动态力学谱表明，增容剂的加入减小了聚丙烯结晶无序化转变，使PP的T_g突出出来。形态的研究说明，PP－EPR还起了“乳化剂”的作用，使EPT在PP连续相中均匀分散，且其微区大小适中。在PP／EPT（85／15）中加入4％的PP－EPR（5－30）嵌段共聚物，室温（20℃）的“冲击屈服强度”与PP／EPT的相同，－20℃的冲击强度为112kg·cm/cm~2，是PP／EPT的1.5倍，－40℃为72kg·cm/cm~2，是PP／EPT的1.9倍，在应力－应变实验中，三元共混物PP／EPT／PP－EPR（5－30）的σ_b*ε_b为2.97*10~5。比相应的PP／EPT（2.27*10~5）有所提高。说明PP－EPR（5－30）对PP／EPT有良好的增容效果，比文献中使用的PP－EPR（15－55）效果好。用PP－EPR－PP三嵌段共聚物作PP／EPT的增容剂，实验证明比PP－EPR二嵌段共聚物有更好的增容效果。例如，在PP／EPT（85／15）中加入4％的PP－EPR－PP（5－60－20），试样不但在20℃，而且在－20℃均未被冲断；在－20℃的“冲击屈服强度”是PP／EPT冲击强度的1.4倍，PP的9.0倍，－40℃的冲击强度是PP／EPT的2.2倍，PP的8.4倍；且其σ_b*ε_b（2.62*10~5）比PP／EPT（2.60*10~5）的有一定的提高，比PP的（2.45*10~5）也高。对PP／EPT／PP－EPR－PP（5－60－20）三元共混物的试样在－40℃冲断面的形态进行研究表明，加入增容剂的共混物断面凹凸不平，是韧性断裂的特征，且在断裂过程中EPT微区被牵拉出的EPT较多，说明PP和EPT的相界面的作用力较大，增容剂起到了主价键的连接作用。动态力学谱表明，增容剂的加入降低了PP结晶无序化转变。而液氮冷冻的脆断面的形态说明，PP－EPR－PP起到了“乳化剂”的作用，使EPT在PP连续相中大小均匀地分散开。

UNSTEADY DIFFUSION KINETICS OF ZIEGLER-NATTA HETEROGENEOUS CATALYST POLYMERIZATION .4. PREDICTION OF EXPERIMENTAL RESULTS OF PROPYLENE ETHYLENE 1-HEXADECENE TERPOLYMERIZATION

The prediction, based on unsteady diffusion kinetics, of the enhancement of reactivity and incorporation of 1-hexadecene in its copolymerization with propylene on adding a small amount of ethylene (increase from 5,2 mol-% to 10,8 mol-% when 2% of ethylene was added, and to 16,1 mol-% when 5% was added) was verified in the terpolymerization of propylene/1-hexadecene/ethylene on a commercial Solvay-type delta-TiCl3 catalyst. The catalyst efficiency was thus also increased. These augmentations originate from the increase in diffusion coefficient of 1-hexadecene at the catalyst surface when the PP crystallinity decreases on introduction of ethylene. Calculation based on unsteady diffusion kinetics showed that the order of diffusion coefficients ethylene > propylene > 1-hexadecene is reversed as the monomer concentration increases when the monomers are not at their equilibrium concentration. Sequence distribution as determined by means of C-13 NMR revealed a tendency of blocky structure rather than a Bernoullian one. The terpolymer compositions obtained by means of an IR method developed in this work conform rather well with the NMR results. Results in this work not only support the unsteady diffusion kinetics but also provide a new route to prepare olefinic copolymer rubbers with heterogeneous titanium catalysts.

Policy impacts on Vietnam stock markets: a case of anomalies and disequilibria 2000-2006

Vietnam launched its first-ever stock market, named as Ho Chi Minh City Securities Trading Center (HSTC) on July 20, 2000. This is one of pioneering works on HSTC, which finds empirical evidences for the following: Anomalies of the HSTC stock returns through clusters of limit-hits, limit-hit sequences; Strong herd effect toward extreme positive returns of the market portfolio;The specification of ARMA-GARCH helps capture fairly well issues such as serial correlations and fat-tailed for the stabilized period. By using further information and policy dummy variables, it is justifiable that policy decisions on technicalities of trading can have influential impacts on the move of risk level, through conditional variance behaviors of HSTC stock returns. Policies on trading and disclosure practices have had profound impacts on Vietnam Stock Market (VSM). The over-using of policy tools can harm the market and investing mentality. Price limits become increasingly irrelevant and prevent the market from self-adjusting to equilibrium. These results on VSM have not been reported before in the literature on Vietnam’s financial markets. Given the policy implications, we suggest that the Vietnamese authorities re-think the use of price limit and give more freedom to market participants.

A new proposition on the martingale representation theorem and on the approximate hedging of contingent claim in mean-variance criterion

In this work we revisit the problem of the hedging of contingent claim using mean-square criterion. We prove that in incomplete market, some probability measure can be identified so that becomes -martingale under .This is in fact a new proposition on the martingale representation theorem. The new results also identify a weight function that serves to be an approximation to the Radon-Nikodým derivative of the unique neutral martingale measure.

The financial storms in Vietnam's transition economy: a reasoning on the 1991-2008 period

This study focuses on those substantial changes that characterize the shift of Vietnam’s macroeconomic structures and evolution of micro-structural interaction over an important period of 1991-2008. The results show that these events are completely distinct in terms of (i) Economic nature; (ii) Scale and depth of changes; (iii) Start and end results; and, (iv) Requirement for macroeconomic decisions. The study rejected a suspicion of similarity between the contagion of the Asian financial crisis in 1997-98 and economic chaos in the first half of 2008 (starting from late 2007). The depth, economic settings of, and interconnection between macro choices and micro decisions have all grown up significantly, partly due to a much deeper level of integration of Vietnam into the world’s economy. On the one hand, this phenomenon gives rise to efficiency of macro level policies because the consideration of micro-structural factors within the framework has definitely become increasingly critical. On the other and, this is a unique opportunity for the macroeconomic mechanism of Vietnam to improve vastly, given the context in which the national economy entered an everchanging period under pressures of globalization and re-integration. The authors hope to also open up paths for further empirical verifications and to stress on the fact that macro policies will have, from now on, to be decided in line with changing micro-settings, which specify a market economy and decide the degree of success of any macroeconomic choices.

Ciencia y conciencia

1er Premio en la categor??a de Ciencia Ingenier??a y Valores de la novena edici??n de 'Ciencia en Acci??n' organizada por El Consejo Superior de Investigaciones Cient??ficas, la Fundaci??n Espa??ola para la Ciencia y la Tecnolog??a, la Real Sociedad Espa??ola de F??sica, la Real Sociedad Matem??tica Espa??ola y la Universidad Nacional de Educaci??n a Distancia, en 2008. Premio 'Operi Bene Peracto' de la Real Academia Espa??ola de Qu??mica, en su edici??n de 2008

Diagnóstico y propuesta para la implementación de un departamento de mercadeo en la multinacional Rhodia Colombia 2012

Este trabajo de grado se realizó con el fin de hacer un diagnóstico para evaluar y analizar la estructuración un departamento de mercadeo en Rhodia Colombia, teniendo en cuenta la coyuntura actual de la compañía y su intensión expansionista en los mercados de industria química en Colombia. Para lograr esta intención es necesario que este departamento pueda llevar procesos de investigación alineados con las estrategias de Marketing que desarrolla Rhodia Brasil, y así mismo brindar a los gerentes comerciales información valiosa para realizar esfuerzos en los mercados potenciales de Rhodia y a los mercados en que se ha posicionado Solvay en Colombia. Las expectativas se fundamentan en lograr establecer un departamento de Mercadeo estructurado donde se lleven a cabo procesos de Marketing “Business to Business” en pro de buscar nuevas oportunidades de mercado, fortalecer la presencia comercial en nichos de mercado estratégicos y monitorear los mercados de la compañía para anticiparse ante los sucesos coyunturales donde interactúan los productos de Rhodia en Colombia.