Day 1 Tue, March 23, 2021最新文献_第2页

Extension of a steady-state chlorine dioxide brightening model for Z-ECF bleaching of softwood kraft pulps 软木硫酸盐纸浆Z-ECF漂白稳态二氧化氯增白模型的扩展

Day 1 Tue, March 23, 2021 Pub Date : 2021-04-01 DOI: 10.32964/tj20.3.186

B. Brogdon, Lucia Lucian

{"title":"Extension of a steady-state chlorine dioxide brightening model for Z-ECF bleaching of softwood kraft pulps","authors":"B. Brogdon, Lucia Lucian","doi":"10.32964/tj20.3.186","DOIUrl":"https://doi.org/10.32964/tj20.3.186","url":null,"abstract":"Earlier studies developed a steady-state model to predict the brightness and/or bleach consumption during the chlorine dioxide brightening (D1) of softwood pulps produced by conventional elemental-chlorine-free (ECF) sequences. This model relates the chlorine dioxide consumed to the brightness gains predicated upon an asymptotic D1 brightness limit, an incoming D1 pulp brightness, and an equation parameter (β11). The current investigation examines the application of this model to ECF sequences that use ozone delignification (Z-ECF). Literature D1 data from various Z-ECF bleaching studies, which investigated OZ, OD0/Z, and OZ/D0 delignification, were fitted to the model. The β11 parameter was found to be linearly correlated to the entering kappa number. Interestingly, this linear relationship was found to be identical to the relationships observed when modeling the D1 stage for conventional ECF and chlorine-based bleach sequences. Subtle differences in D1 brightening response in the model among the various bleach sequences are reflected by incoming pulp brightness (at the same kappa number). The current model is used to illustrate how alterations to Z-ECF delignification affect D1 brightening and chlorine dioxide consumption.","PeriodicalId":11002,"journal":{"name":"Day 1 Tue, March 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87694700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Boiler retrofit improves efficiency and increases biomass firing rates 锅炉改造提高了效率，增加了生物质燃烧率

Day 1 Tue, March 23, 2021 Pub Date : 2021-04-01 DOI: 10.32964/tj20.3.173

S. Pethe, Paul W. Cloninger, Ryan R. Shortreed, Ken M. Hardison

{"title":"Boiler retrofit improves efficiency and increases biomass firing rates","authors":"S. Pethe, Paul W. Cloninger, Ryan R. Shortreed, Ken M. Hardison","doi":"10.32964/tj20.3.173","DOIUrl":"https://doi.org/10.32964/tj20.3.173","url":null,"abstract":"Domtar’s fluff pulp mill in Plymouth, NC, USA, operates two biomass/hog fuel fired boilers (HFBs). For energy consolidation and reliability improvement, Domtar wanted to decommission the No. 1 HFB and refurbish/retrofit the No. 2 HFB. \u0000The No. 2 HFB was designed to burn pulverized coal and/or biomass on a traveling grate. The steaming capacity was 500,000 lb/h from coal and 400,000 lb/h from biomass. However, it had never sustained this design biomass steaming rate. As the sole power boiler, the No. 2 HFB would need to sustain 400,000 lb/h of biomass steam during peak loads. \u0000An extensive evaluation by a combustion and boiler technologies supplier was undertaken. The evaluation involved field testing, analysis, and computational fluid dynamics (CFD) modeling, and it identified several bottle-necks and deficiencies to achieving the No. 2 HFB’s biomass steam goal. These bottlenecks included an inadequate combustion system; insufficient heat capture; excessive combustion air temperature; inadequate sweetwater con-denser (SWC) capacity; and limited induced draft fan capacity.\u0000To address the identified deficiencies, various upgrades were engineered and implemented. These upgrades included modern pneumatic fuel distributors; a modern sidewall, interlaced overfire air (OFA) system; a new, larger economizer; modified feedwater piping to increase SWC capacity; replacement of the scrubber with a dry electro-static precipitator; and upgraded boiler controls.\u0000With the deployment of these upgrades, the No. 2 HFB achieved the targeted biomass steaming rate of 400,000 lb/h, along with lowered stack gas and combustion air temperatures. All mandated emissions limit tests at 500,000 lb/h of steam with 400,000 lb/h of biomass steam were passed, and Domtar reports a 10% reduction in fuel firing rates, which represents significant fuel savings. In addition, the mill was able to decommission the No. 1 HFB, which has substantially lowered operating and maintenance costs.","PeriodicalId":11002,"journal":{"name":"Day 1 Tue, March 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81670373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development of converging-diverging multi-jet nozzles for molten smelt shattering in kraft recovery boilers 硫酸盐回收锅炉熔体粉碎用聚散式多喷嘴的研制

Day 1 Tue, March 23, 2021 Pub Date : 2021-04-01 DOI: 10.32964/tj20.3.199

E. Jin, T. Habib, Simon Youssef, Steve Osborne, H. Tran

引用次数: 0

INFLUENCE OF CLASS SIZE ON STUDENTS’ AND TEACHERS’ MOTIVATION DURING INSTRUCTION 班级规模对学生和教师教学动机的影响

Day 1 Tue, March 23, 2021 Pub Date : 2021-03-30 DOI: 10.51380/GUJR-37-01-10

Syed M Amir, I. Ullah, M. Kaleem

引用次数: 1

PERCEPTIONS OF TEACHER EDUCATORS AND PROSPECTIVE TEACHERS ON THE ASSESSMENT LITERACY AND PRACTICES 教师教育者和准教师对评估素养和实践的看法

Day 1 Tue, March 23, 2021 Pub Date : 2021-03-30 DOI: 10.51380/GUJR-37-01-07

S. Hussain, M. Idris, Zarina Akhtar

{"title":"PERCEPTIONS OF TEACHER EDUCATORS AND PROSPECTIVE TEACHERS ON THE ASSESSMENT LITERACY AND PRACTICES","authors":"S. Hussain, M. Idris, Zarina Akhtar","doi":"10.51380/GUJR-37-01-07","DOIUrl":"https://doi.org/10.51380/GUJR-37-01-07","url":null,"abstract":"This study explores the teacher educators' and prospective teachers’ perceptions regarding classroom assessment literacy and practices. It specifically aims to respond to questions: ‘what teacher educators and student teachers perceive with regard to classroom assessment, purposes, approaches, literacy and practices? How many perceptual differences exist between teacher educators and student teachers on classroom assessment practices? Through sequential triangulation, mixed-method research design data were collected over interview protocols and a Likert design questionnaire. Further, qualitative data were analyzed through a thematic approach while quantitative data were analyzed through mean scores and t-test. The results indicated significant differences in the understanding of classroom assessment practices of teacher educators and student teachers. Furthermore, student teachers feel tense due to prevalent assessment mechanisms. The results also revealed that prevalent assessment approaches fall short of developing requisite skills among student teachers. Thus, alternative assessment practices with more students centered and real-life approaches were recommended for prospective teachers in classroom situations.","PeriodicalId":11002,"journal":{"name":"Day 1 Tue, March 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84895857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

OIL PRICES MOVEMENTS AND INDUSTRY STOCK RETURNS: EVIDENCE FROM PAKISTAN STOCK EXCHANGE (PSX) 石油价格变动和行业股票回报:来自巴基斯坦证券交易所(psx)的证据

Day 1 Tue, March 23, 2021 Pub Date : 2021-03-30 DOI: 10.51380/GUJR-37-01-08

M. Asif, Sharif Ullah Jan, Shabab Iqbal

引用次数: 1

IMPACT OF ETHICS, STRESS AND TRUST ON CHANGE MANAGEMENT IN PUBLIC SECTOR ORGANIZATION 道德、压力和信任对公共部门组织变革管理的影响

Day 1 Tue, March 23, 2021 Pub Date : 2021-03-30 DOI: 10.51380/GUJR-37-01-05

S. Ahmad, Muhammad Ibrahim, A. Nadeem

引用次数: 3

THE EFFECTS OF STRUCTURAL CAPITAL ON ORGANISATIONAL EFFICIENCY 结构资本对组织效率的影响

Day 1 Tue, March 23, 2021 Pub Date : 2021-03-30 DOI: 10.51380/GUJR-37-01-01

F. O. Edeh, Yeo Sook Fern, A. Nawaz