期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
试论施工企业工程成本项目的控制
1
作者 宁桂琴 邓小秋 《经济技术协作信息》 2002年第15期9-9,共1页
关键词 成本控制 人工费成本 材料费成本 机械使用费成本 施工企业 工程成本项目
下载PDF
工程项目成本管理措施探讨
2
作者 陈晓寅 《中国电子商务》 2011年第9期221-221,共1页
本文分析了当前工程项目成本管理存在的问题,提出了相应的加强成本管理措施,供大家参考。
关键词 建筑工程成本管理人工费材料费
下载PDF
Kinetic Modeling of Esterification Reaction of Free Fatty Acids Present in Macauba Oil Using a Cationic Resin as Catalyst
3
作者 Daniel Bastos de Rezende Carlos Augusto Silva +1 位作者 Vanya Marcia Duarte Pasa Maria Helena Carlo de Andrade 《Journal of Chemistry and Chemical Engineering》 2015年第3期153-161,共9页
The cost of raw materials has the largest contribution to the final price of biodiesel produced by traditional routes, currently adopted in most industrial scale processes. That contribution comes from the need to use... The cost of raw materials has the largest contribution to the final price of biodiesel produced by traditional routes, currently adopted in most industrial scale processes. That contribution comes from the need to use edible and noble oils, with low acidity, such as soybean oil. This work proposes'the use of Macauba oil, a vegetable oil in focus in the State of Minas Gerais, Brazil, in which the current extractive yield generates a raw material with high acidity, therefore, not suitable to be used in biodiesel production. To make it technically feasible, a cationic exchange resin, the Purolite CT275DR, was used as a catalyst for esterification reaction with samples of Macauba oil, aiming to reduce its acidity. The resin can be reused, regenerated and easily removed from the reaction product, reducing costs with catalyst and purification stages. As a result of this work, in a sample of oil with an initial acidity of about 10% m/m were achieved acidity reductions up to 97% by using cationic resins as catalyst, demonstrating its potential use in the oil pretreatrnent step. Additionally, the data collected during all the analysis made it possible to define the chemical kinetic of the esterification reaction. 展开更多
关键词 ESTERIFICATION chemical kinetic cationic resin Acrocomiaaculeata free fatty acids.
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部