نتایج جستجو برای: the burst strength

تعداد نتایج: 16089097  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1391

one of the most commonly used techniques to reduce the corrosion rate of rebar in concrete is addition substances named corrosion inhibitors into the concrete. corrosion inhibitor is chemical compounds that were added to concrete to prevent corrosion of steel in concrete. sodium nitrate is a type of anodic inhibitors that this study investigatesthe effect of this inhibitor on the properties of ...

Journal: :پژوهش های علوم و فناوری چوب و جنگل 0

this study was conducted to compare the yield and strength properties of soda and kraft pulp produced from populus deltoeides sapwood and heartwood. initially fiber length, lignin content in both sapwood and heartwood were measured. then from either sapwood or heartwood pulps were prepared with using soda and kraft processes, handsheets were made from this pulp and mechanical properties were me...

2014
Yuanhua Lin Kuanhai Deng Yongxing Sun Dezhi Zeng Wanying Liu Xiangwei Kong Ambrish Singh

The internal pressure strength of tubing and casing often cannot satisfy the design requirements in high pressure, high temperature and high H2S gas wells. Also, the practical safety coefficient of some wells is lower than the design standard according to the current API 5C3 standard, which brings some perplexity to the design. The ISO 10400: 2007 provides the model which can calculate the burs...

Journal: :جنگل و فرآورده های چوب 0
ایمان رشیدی جویباری دانشجوی دکتری گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران محمد آزادفلاح استادیار گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران حسین رسالتی استاد گروه علوم و صنایع چوب و کاغذ، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران یحیی همزه استاد گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران

utilization of long fiber chemical pulp to enhance the strength properties of mechanical and chemi-mechanical pulp is served as a common approach by the papermakers. therefore softwood long fibers were exposed to chemical modification by cationic agent, eptmac, with the aim of reducing its consumption. then, the cationised fibers were mixed with cmp pulp with given ratios and the handsheets wer...

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشگاه پلیمر و پتروشیمی ایران - پژوهشکده پتروشیمی 1389

this is an original study on the effect of a polyisobutylene – polydimethylsiloxane (pibpdms) block copolymer modifier used as an interfacial active agent on the dynamics behaviour of single newtonian drops suspended in a polyisobutylene (pib) newtonian matrix. the results were divided in two sections. the first part included the experiments carried out on the non-modified and 2% block cop...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1391

we have two part in this thesis, at first: the interaction of native calf thymus dna (ct-dna) with two anthraquinones including quinizarin (1,4- dihydroxy anthraquinone) and danthron (1,8- dihydroxy anthraquinone) in a mixture of 0.04 m brittone-robinson buffer and 50% of ethanol were studied at physiological ph by uv-vis absorption, florescence, circular dichroism spectroscopic methods, viscos...

Journal: :پژوهش های علوم و فناوری چوب و جنگل 0

the present research has been conducted to investigate the soda and soda-anthraquiuone pulping from whole kenaf (v36). in this respect, anatomical characteristics of kenaf bast and core fibers as well as the soda and soda-aq pulp properties produced at four sodium hydroxide concentrations, namely 25, 30, 35 and 40 (g/lit), have been evaluated. the pulping results indicated that pulp yield and k...

پایان نامه :وزارت بهداشت، درمان و آموزش پزشکی - دانشگاه علوم پزشکی و خدمات بهداشتی درمانی مشهد - دانشکده دندانپزشکی 1390

objective: the objective of this study was to investigate the invitro fluoride release of four new self-adhesive resin cements; set (sdi, australia), breeze (pentron, usa), embrace wetbond (pulpdent, usa), g-cem (gc, japan) and to assess the bonding performance of these self-adhesive resin cements for bonding of orthodontic brackets. materials and methods: for fluoride release experiment, six ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

some new water-soluble schiff base complexes of na2[m(5-so3-1,2-salophen)].nh2o; (5-so3-1,2-salophen = n,n’-bis(5-sulphosalicyliden)-1,2-phenylendiamine); na2[m(5-so3-2,3-salpyr)(h2o)n].2h2o; (5-so3-2,3-salpyr = n,n’-bis(5-sulphosalicyliden)-2,3-diaminopyridine); and na2[m(5-so3-3,4-salbenz)(h2o)n].nh2o; (5-so3-3,4-salbenz = n,n’-bis(5-sulphosalicyliden)-3,4-diaminobenzophenon); where m = cu, n...

Journal: :علوم و تکنولوژی پلیمر 0
حسین جلالی ترشیزی سید احمد میرشکرایی مهدی فائزی پور یحیی حمزه حسین رسالتی

biopolymers are environmental friendly sources as renewable and sustainable substituents for petroleum-based polymers. application of these polymers is common in variety of industries including papermaking. herbalexudate gums have been used in papermaking industry for decades, especially paper recycling. in this study, gum polysaccharide exudates from baridje plant  (ferula gummosa) extracted a...

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