نتایج جستجو برای: oxygen delignification is applied on occ

تعداد نتایج: 11401832  

Journal: :جنگل و فرآورده های چوب 0
محمد حسین کربلایی اسمعیل گروه علوم و صنایع چوب و کاغذ، دانشگاه آزاد اسلامی واحد کرج، کرج، ایران احمد جهان لتیباری دانشگاه آزاد اسلامی – واحد کرج کرج – مهرشهر – بلوار امام خمینی (ره) – بلوار آزادی – دانشکده کشاورزی و منابع طبیعی سید محمد جواد سپیده دم استادیار، گروه علوم و صنایع چوب و کاغذ، دانشگاه آزاد اسلامی واحد کرج، کرج، ایران مهران روح نیا گروه علوم و صنایع چوب و کاغذ، دانشگاه آزاد اسلامی واحد کرج، ، ایران

the kinetics of old corrugated container (occ) soda-oxygen delignification was investigated. three delignification temperatures (145,165 and 175ºc) were applied. the pulping duration was adjusted at 150 minutes and the measurements were conducted at 10 minutes intervals. the pulping consistency, oxygen pressure and active alkali were constant at 10%, 6 bar and 18% naoh respectively in all pulpi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده فنی و مهندسی 1388

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده علوم ریاضی و مهندسی کامپیوتر 1392

heuristics are often used to provide solutions for flow shop scheduling problems.the performance of a heuristic is usually judged by comparing solutions and run times on test cases.this investigation proposes an analytical alternative ,called asymptotic convergence ,which tests the convergence of the heuristic to a lower bound as problem size grows. the test is a stronger variation of worst cas...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد 1388

hedging is a multi-purpose rhetorical strategy which is usually used in scientific arguments to secure ratification of claims, reduce the risk of negation, avoid conflict, manage disagreement and leave room for the audience to assess presented information. hedges are frequently used in research articles to mitigate the findings of research endeavors. the present research aims to investigate the...

2013
Shilin Cao Xiaojuan Ma Xiaolin Luo Fang Huang Liulian Huang Lihui Chen

The main challenge in the oxygen delignification process is the improvement of selectivity. To further understand the effect of the amount of hydroxyl radicals on the selectivity of oxygen delignification, in this work, the hydroxyl radicals were generated by the improved Fenton reaction system and were quantified by UV spectrophotometry. Antioxidants such as ascorbic acid were applied for the ...

پایان نامه :0 1374

this experimental study has been conducted to test the effect of oral presentation on the development of l2 learners grammar. but this oral presentation is not merely a deductive instruction of grammatical points, in this presentation two hypotheses of krashen (input and low filter hypotheses), stevicks viewpoints on grammar explanation and correction and widdowsons opinion on limited use of l1...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم پایه 1391

bekenstein and hawking by introducing temperature and every black hole has entropy and using the first law of thermodynamic for black holes showed that this entropy changes with the event horizon surface. bekenstein and hawking entropy equation is valid for the black holes obeying einstein general relativity theory. however, from one side einstein relativity in some cases fails to explain expe...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیخ بهایی - دانشکده زبانهای خارجی 1393

abstract foreign and iranian cultures are far distinct in the constraints imposed on writing and translating for children, since the iranian literary system is mainly concerned with cultural and religious instructions which lead to manipulation of translated texts. this study sought to identify the cultural and social constraints and norms which determined the strategies applied in the transl...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان همدان - دانشکده ادبیات و علوم انسانی 1390

abstract this study is an attempt to determine the effect of nano- technology education on science lesson for fifth grade in primary school in the city of kermanshah. this research is experimental and is conducted in the from of pre-test and post- test for the control group. an achievement test was administered to determine the rate of learning in the students. the research is an applied one. ...

2012
Helena Wedin Stefan Antonsson Mikael E. Lindström

Common metrics for evaluating the efficiency of oxygen delignification include the kappa number and Klason lignin content. As a change in xylan content often leads to a change in HexA content, the kappa number must be corrected for the HexA contribution before evaluating the degree of oxygen delignification when trying to understand the process in detail. Questions could also be raised about th...

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