Im postrevolutionären Mexiko der 1930er Jahre war das Bedürfnis nach stabiler historischer Selbstverständigung groß und konnte vor allem durch das aufblühende Medium des Films weitläufig gestillt werden. Als besonders geeignet für die Modellierung eines kollektiven mexikanischen Geschichtsbewusstseins erwiesen sich Mnemotope - Orte, an welchen sich retrospektiv ein Gemeinschaftssinn konstituieren lässt. Sergej Gordon untersucht die als neuartige historische Quelle gefeierte Kinematographie der Época de Oro (1936-1956) und deckt dabei ihre Genialität als Traumfabrik und Setzkasten ortsgestützter Vergangenheitsbezüge auf.
20世纪30年代革命后的墨西哥对稳定的历史相互理解的需求是巨大的，它在很大程度上受到了电影媒介繁荣的震撼。事实证明，为纪念墨西哥一个集体历史学的方法特别有效，该方法需要一纸文字带，一个反传统意识是建立一种集体意识的。谢尔盖·戈登研究的知名Kinematographie新的历史来源Época de Oro(1936-1956),其品质当作烦嚣,覆盖Setzkasten ortsgestützter Vergangenheitsbezüge .上
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Pub Date : 2021-10-01DOI: 10.1177/87560879211051790
J. Wagner
EDITOR,—While the content of food, pharmaceutical products, drugs, and many other consumer goods are tightly regulated by governments, tobacco products, surprisingly, are not. Tar and nicotine yields of cigarettes have progressively, but not universally, appeared on cigarette packets and advertising since 1967. These figures have been used to justify terms such as “light” and “mild” in descriptive advertising. In 1981 a US public health report concluded: “the preponderance of scientific evidence strongly suggests that the lower the “tar” and nicotine content of the cigarette, the less harmful would be the eVect.” Some early reports concluded, plausibly, that a decrease in lung cancer mortality could be ascribed to smoking reduced tar cigarettes, although more recent data suggest that there is little if any diVerence in the long term outcome of smoking “low tar” as against “regular” cigarettes. Further there has been an increase in adenocarcinoma relative to squamous carcinoma, more pronounced in women than men, and this may be caused by the increases in tobacco specific nitrosamines in cigarettes plus more intense (compensatory) smoking and deeper inhalation associated with modern cigarettes. 4 We decided to test three global brands (Camel, Lucky Strike, and Marlboro) for consistency of tar and nicotine yields and for two tobacco specific nitrosamines, 4 (methylnitrosamino) 1 (3-pyridyl) 1 butanone (NNK), and N-nitrosonornicotin (NNN). The former is a powerful lung adenocarcinogen, regardless of route of administration, and the latter is an established oesophageal carcinogen in animals. The methods used have been described by HoVmann. 6 The cigarettes were purchased in 29 countries by volunteers (the International Cigarette Variation Group), who purchased the premium example available, which were, in most cases, filtered. No “light”, “mild”, “menthol” or other variants were purchased. Forty cigarettes of each brand were analysed at the Institute of Carcinogenesis in Moscow. Not all brands were available in each country and it is not known whether those purchased were locally produced, imported or smuggled, or how long they had been stored before sale. This is not a representative sample—the cigarettes were acquired as they would be by the person in the street. Our aim was to investigate international variation. The results of the tar and nicotine testing were unremarkable. Generally they conformed to the packet statement (where present). Tar yield ranged from 10.6 mg/cig to 15.7 mg/cig for Camel, 11.8 mg/cig to 20.4 mg/cig for Lucky Strike, and 8.4 mg/cig to 15.9 mg/cig for Marlboro. Nicotine yield ranged from 0.85 mg/cig to 1.3 mg/cig for Camel and Lucky Strike, and 0.68 mg/cig to 1.25 mg/cig for Marlboro. DiVerences in nitrosamine yields were substantial. There is a threefold diVerence between the lowest and highest yields of NNK for Camel, a fivefold diVerence for Lucky Strike, and ninefold for Marlboro (fig 1). NNK and NNN yields are highly c
{"title":"From the Editor","authors":"J. Wagner","doi":"10.1177/87560879211051790","DOIUrl":"https://doi.org/10.1177/87560879211051790","url":null,"abstract":"EDITOR,—While the content of food, pharmaceutical products, drugs, and many other consumer goods are tightly regulated by governments, tobacco products, surprisingly, are not. Tar and nicotine yields of cigarettes have progressively, but not universally, appeared on cigarette packets and advertising since 1967. These figures have been used to justify terms such as “light” and “mild” in descriptive advertising. In 1981 a US public health report concluded: “the preponderance of scientific evidence strongly suggests that the lower the “tar” and nicotine content of the cigarette, the less harmful would be the eVect.” Some early reports concluded, plausibly, that a decrease in lung cancer mortality could be ascribed to smoking reduced tar cigarettes, although more recent data suggest that there is little if any diVerence in the long term outcome of smoking “low tar” as against “regular” cigarettes. Further there has been an increase in adenocarcinoma relative to squamous carcinoma, more pronounced in women than men, and this may be caused by the increases in tobacco specific nitrosamines in cigarettes plus more intense (compensatory) smoking and deeper inhalation associated with modern cigarettes. 4 We decided to test three global brands (Camel, Lucky Strike, and Marlboro) for consistency of tar and nicotine yields and for two tobacco specific nitrosamines, 4 (methylnitrosamino) 1 (3-pyridyl) 1 butanone (NNK), and N-nitrosonornicotin (NNN). The former is a powerful lung adenocarcinogen, regardless of route of administration, and the latter is an established oesophageal carcinogen in animals. The methods used have been described by HoVmann. 6 The cigarettes were purchased in 29 countries by volunteers (the International Cigarette Variation Group), who purchased the premium example available, which were, in most cases, filtered. No “light”, “mild”, “menthol” or other variants were purchased. Forty cigarettes of each brand were analysed at the Institute of Carcinogenesis in Moscow. Not all brands were available in each country and it is not known whether those purchased were locally produced, imported or smuggled, or how long they had been stored before sale. This is not a representative sample—the cigarettes were acquired as they would be by the person in the street. Our aim was to investigate international variation. The results of the tar and nicotine testing were unremarkable. Generally they conformed to the packet statement (where present). Tar yield ranged from 10.6 mg/cig to 15.7 mg/cig for Camel, 11.8 mg/cig to 20.4 mg/cig for Lucky Strike, and 8.4 mg/cig to 15.9 mg/cig for Marlboro. Nicotine yield ranged from 0.85 mg/cig to 1.3 mg/cig for Camel and Lucky Strike, and 0.68 mg/cig to 1.25 mg/cig for Marlboro. DiVerences in nitrosamine yields were substantial. There is a threefold diVerence between the lowest and highest yields of NNK for Camel, a fivefold diVerence for Lucky Strike, and ninefold for Marlboro (fig 1). NNK and NNN yields are highly c","PeriodicalId":16823,"journal":{"name":"Journal of Plastic Film & Sheeting","volume":"158 1","pages":"399 - 401"},"PeriodicalIF":3.1,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74071395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-01DOI: 10.1177/87560879211051792
Karen Xiao, Charlie Martin
Calendar of future events October 17–21, 2021 The AIMCAL R2R Conference has been a champion of roll-to-roll processing and the converting industry for many years. If you are a newcomer to this annual event, you will see why it consistently rates high as a valuable resource for anyone who has interest in the R2R process. The conference has steadily grown by delivering solid technical programming and valuable networking opportunities to attendees. This year, the conference will be held in Orlando, Florida, from October 17th to 21st. We are happy to once again partner with the SPE Flexible Packaging Division to bring you the absolute best in technical content spanning the industry. Learn more: https://aimcal.org/AIMCAL/Events/R2R-Conference.aspx
{"title":"Industry News","authors":"Karen Xiao, Charlie Martin","doi":"10.1177/87560879211051792","DOIUrl":"https://doi.org/10.1177/87560879211051792","url":null,"abstract":"Calendar of future events October 17–21, 2021 The AIMCAL R2R Conference has been a champion of roll-to-roll processing and the converting industry for many years. If you are a newcomer to this annual event, you will see why it consistently rates high as a valuable resource for anyone who has interest in the R2R process. The conference has steadily grown by delivering solid technical programming and valuable networking opportunities to attendees. This year, the conference will be held in Orlando, Florida, from October 17th to 21st. We are happy to once again partner with the SPE Flexible Packaging Division to bring you the absolute best in technical content spanning the industry. Learn more: https://aimcal.org/AIMCAL/Events/R2R-Conference.aspx","PeriodicalId":16823,"journal":{"name":"Journal of Plastic Film & Sheeting","volume":"414 1","pages":"402 - 408"},"PeriodicalIF":3.1,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84890517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Das Kontrastpaar »Zombies und Kirche« schlägt sich teils prominent in der Popkultur nieder: Quality TV-Formate wie The Walking Dead inszenieren die titelgebenden Untoten in christlich-religiösen Kontexten. Daniel Hercenberger nimmt eine theologische Filmanalyse der US-amerikanischen Serien The Walking Dead und Fear the Walking Dead vor und zeigt anhand exemplarischer Szenen und Figuren, wie postmortale Existenzen Säkularisierungsprozesse versinnbildlichen. Die kulturhistorische Betrachtung des figuralen Motivs macht deutlich, dass sich die Figur des Zombies im Besonderen für eine derartige Allegorisierung eignet.
{"title":"Zombies in der Kirche","authors":"Daniel Hercenberger","doi":"10.14361/9783839459690","DOIUrl":"https://doi.org/10.14361/9783839459690","url":null,"abstract":"Das Kontrastpaar »Zombies und Kirche« schlägt sich teils prominent in der Popkultur nieder: Quality TV-Formate wie The Walking Dead inszenieren die titelgebenden Untoten in christlich-religiösen Kontexten. Daniel Hercenberger nimmt eine theologische Filmanalyse der US-amerikanischen Serien The Walking Dead und Fear the Walking Dead vor und zeigt anhand exemplarischer Szenen und Figuren, wie postmortale Existenzen Säkularisierungsprozesse versinnbildlichen. Die kulturhistorische Betrachtung des figuralen Motivs macht deutlich, dass sich die Figur des Zombies im Besonderen für eine derartige Allegorisierung eignet.","PeriodicalId":16823,"journal":{"name":"Journal of Plastic Film & Sheeting","volume":"82 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73542992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Since its inception, U.S. American cinema has grappled with the articulation of racial boundaries. This applies, in the first instance, to featuring mixed-race characters crossing the color line. In a broader sense, however, this also concerns viewing conditions and knowledge configurations. The fact that American film engages itself so extensively with the unbalanced relation between black and white is neither coincidental nor trivial to state — it has much more to do with disputing boundaries that pertain to the medium itself. Lisa Gotto examines this constellation along the early history of American film, the cinematic modernism of the late 1950s, and the post-classical cinema of the turn of the millennium.
{"title":"Passing and Posing between Black and White","authors":"Lisa Gotto","doi":"10.14361/9783839453377","DOIUrl":"https://doi.org/10.14361/9783839453377","url":null,"abstract":"Since its inception, U.S. American cinema has grappled with the articulation of racial boundaries. This applies, in the first instance, to featuring mixed-race characters crossing the color line. In a broader sense, however, this also concerns viewing conditions and knowledge configurations. The fact that American film engages itself so extensively with the unbalanced relation between black and white is neither coincidental nor trivial to state — it has much more to do with disputing boundaries that pertain to the medium itself. Lisa Gotto examines this constellation along the early history of American film, the cinematic modernism of the late 1950s, and the post-classical cinema of the turn of the millennium.","PeriodicalId":16823,"journal":{"name":"Journal of Plastic Film & Sheeting","volume":"15 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89643032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-02DOI: 10.1177/87560879211043558
Ayesha Kausar
Boehmite [bey-mahyt] is a unique aluminum oxide hydroxide nanostructure. It consists of nanosheets of octahedral aluminum ions with surface hydroxyl groups. Owing to exceptional reinforcing behavior, boehmite nanoparticles have gained immense attention as polymeric nanofillers. Essential matrices used with the boehmite based nanocomposites include poly(methyl methacrylate), polyethylene, polypropylene, polyamide, epoxy, and other polymers. In this review, all-inclusive considerations on the design, morphology, mechanical, thermal, electrical, ion conducting, flame retardancy, electrochemical, and other physical properties, and advances related to the polymer/boehmite nanocomposites are presented. The polymer/boehmite nanocomposites have been employed for the membranes (water filtration/dye removal), coatings (anti-corrosion/self-healing), Li-ion batteries, and non-flammability purposes.
{"title":"A review of current knowledge and future trends in polymer/boehmite nanocomposites","authors":"Ayesha Kausar","doi":"10.1177/87560879211043558","DOIUrl":"https://doi.org/10.1177/87560879211043558","url":null,"abstract":"Boehmite [bey-mahyt] is a unique aluminum oxide hydroxide nanostructure. It consists of nanosheets of octahedral aluminum ions with surface hydroxyl groups. Owing to exceptional reinforcing behavior, boehmite nanoparticles have gained immense attention as polymeric nanofillers. Essential matrices used with the boehmite based nanocomposites include poly(methyl methacrylate), polyethylene, polypropylene, polyamide, epoxy, and other polymers. In this review, all-inclusive considerations on the design, morphology, mechanical, thermal, electrical, ion conducting, flame retardancy, electrochemical, and other physical properties, and advances related to the polymer/boehmite nanocomposites are presented. The polymer/boehmite nanocomposites have been employed for the membranes (water filtration/dye removal), coatings (anti-corrosion/self-healing), Li-ion batteries, and non-flammability purposes.","PeriodicalId":16823,"journal":{"name":"Journal of Plastic Film & Sheeting","volume":"21 1","pages":"278 - 305"},"PeriodicalIF":3.1,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77258237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-03DOI: 10.1177/87560879211035429
M. Mughees, M. Sajid, H. Shahzad, M. Sadiq, N. Ali
This study explores the blade coating process with a simple fixed blade for a second-grade fluid over a moving porous substrate. The article investigates both plane and exponential blade coating. The analysis simplifies the governing equations via lubrication approximation theory by assuming that blade length is much larger than the coating layer thickness. Suitable scales normalize the governing equations. The expressions for pressure gradient and velocity are analytically obtained whereas pressure is attained using a so-called “shooting method” numerical technique. How the Reynolds number R e , suction velocity v 0 and non-Newtonian second-grade parameter ϵ affect the velocity, pressure gradient, pressure, coating layer thickness and load on the blade are observed and displayed graphically and as tables. Interesting engineering quantities like velocity, pressure gradient and pressure are highlighted in graphical form whereas load and thickness are presented as tables. It is observed that the pressure gradient, pressure, velocity, load and thickness decrease as the parameters ∈ and R e and v 0 icrease for the cases of both plane and exponential coaters while all these physical quantities are observed to increase when the parameter ∈ increases. The most important physical quantity is the load for it is responsible in maintaining the coating quality and thickness. Moreover, it is perceived that the load decreases as the Reynolds number R e and v 0 increases get accelerated and it increases when parameter ϵ is increased.
{"title":"An exact solution for blade coating of a second-grade fluid on a porous substrate","authors":"M. Mughees, M. Sajid, H. Shahzad, M. Sadiq, N. Ali","doi":"10.1177/87560879211035429","DOIUrl":"https://doi.org/10.1177/87560879211035429","url":null,"abstract":"This study explores the blade coating process with a simple fixed blade for a second-grade fluid over a moving porous substrate. The article investigates both plane and exponential blade coating. The analysis simplifies the governing equations via lubrication approximation theory by assuming that blade length is much larger than the coating layer thickness. Suitable scales normalize the governing equations. The expressions for pressure gradient and velocity are analytically obtained whereas pressure is attained using a so-called “shooting method” numerical technique. How the Reynolds number R e , suction velocity v 0 and non-Newtonian second-grade parameter ϵ affect the velocity, pressure gradient, pressure, coating layer thickness and load on the blade are observed and displayed graphically and as tables. Interesting engineering quantities like velocity, pressure gradient and pressure are highlighted in graphical form whereas load and thickness are presented as tables. It is observed that the pressure gradient, pressure, velocity, load and thickness decrease as the parameters ∈ and R e and v 0 icrease for the cases of both plane and exponential coaters while all these physical quantities are observed to increase when the parameter ∈ increases. The most important physical quantity is the load for it is responsible in maintaining the coating quality and thickness. Moreover, it is perceived that the load decreases as the Reynolds number R e and v 0 increases get accelerated and it increases when parameter ϵ is increased.","PeriodicalId":16823,"journal":{"name":"Journal of Plastic Film & Sheeting","volume":"25 1","pages":"245 - 262"},"PeriodicalIF":3.1,"publicationDate":"2021-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76078058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-03DOI: 10.1177/87560879211037387
Lisa-Maria Wittmann, D. Drummer
Multilayer sheets were used for thermoforming non thermoformable polymers in order to face the challenge of semi-crystalline polymers like low melt-stiffness. Mono- and 2-layer sheets consisting of different polypropylene (PP) homopolymers were extruded on a twin screw extruder. The PP viscosity as was measured by melt flow rate (MFR) 3 g/10 min., 12 g/10 min., 22 g/10 min. and 50 g/10 min. The layer ratio was varied between the equal layer ratio (A50/B50) of the individual layers and the low (A30/B70) or high viscosity ratio (A70/B30). The extrusion results show that for extreme viscosity differences (MFR3 and MFR50), the critical layer ratios known from the literature are only valid to a limited extent. The critical viscosity ratio < 4, which is known from the literature, is much lower here and should be less than 3. The investigation of thermoformability on laboratory scale of the extruded PP sheets with different viscosities showed that the low viscous layer position has only a marginal influence on the general thermoformability. Thermoforming of materials that are not thermoformable, with a storage modulus of less than 10³ Pa and a ratio between storage and loss modulus (tan δ) greater than 1, becomes possible using a multilayer sheet independant of the layer ratio. If the layer with higher viscosity acts as a stabilizing layer, thermoforming is possible.
{"title":"Multilayer sheets for thermoforming non thermoformable polymers","authors":"Lisa-Maria Wittmann, D. Drummer","doi":"10.1177/87560879211037387","DOIUrl":"https://doi.org/10.1177/87560879211037387","url":null,"abstract":"Multilayer sheets were used for thermoforming non thermoformable polymers in order to face the challenge of semi-crystalline polymers like low melt-stiffness. Mono- and 2-layer sheets consisting of different polypropylene (PP) homopolymers were extruded on a twin screw extruder. The PP viscosity as was measured by melt flow rate (MFR) 3 g/10 min., 12 g/10 min., 22 g/10 min. and 50 g/10 min. The layer ratio was varied between the equal layer ratio (A50/B50) of the individual layers and the low (A30/B70) or high viscosity ratio (A70/B30). The extrusion results show that for extreme viscosity differences (MFR3 and MFR50), the critical layer ratios known from the literature are only valid to a limited extent. The critical viscosity ratio < 4, which is known from the literature, is much lower here and should be less than 3. The investigation of thermoformability on laboratory scale of the extruded PP sheets with different viscosities showed that the low viscous layer position has only a marginal influence on the general thermoformability. Thermoforming of materials that are not thermoformable, with a storage modulus of less than 10³ Pa and a ratio between storage and loss modulus (tan δ) greater than 1, becomes possible using a multilayer sheet independant of the layer ratio. If the layer with higher viscosity acts as a stabilizing layer, thermoforming is possible.","PeriodicalId":16823,"journal":{"name":"Journal of Plastic Film & Sheeting","volume":"1 1","pages":"225 - 244"},"PeriodicalIF":3.1,"publicationDate":"2021-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88742559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-05DOI: 10.1177/87560879211026010
ME Ismail, MM Awad, A. Hamed, MY Abdelaal, EB Zeidan
This study experimentally and numerically investigates a typical HDPE blown film production process cooled via a single-lip air-ring. The processing observations are considered for the proposed subsequent modifications on the air-ring design and the location relative to the die to generate a radial jet, directly impinging on the bubble. Measurements are performed to collect the actual operating parameters to set up the numerical simulations. The radiation heat transfer and the polymer phase change are considered in the numerical simulations. The velocity profile at the air-ring upper-lip is measured via a five-hole Pitot tube to compare with the numerical results. The comparison between the measurements and the numerical results showed that the simulations with the STD k – ω turbulence model are more accurate with a minimum relative absolute error (RAE) of 1.6%. The numerical results indicate that the peak Heat Transfer Coefficient (HTC) at the impingement point for the modified design with radial jet and longer upper-lip is 29.1% higher than the original design at the same conditions. Besides, increasing the air-ring upper-lip height increased the averaged HTC, which is 13.4% higher than the original design.
本文通过实验和数值研究了一种典型的单唇气环冷却的HDPE吹膜生产工艺。加工过程的观察结果被认为是对气环设计和相对于模具的位置的后续修改，以产生径向射流，直接撞击气泡。进行测量以收集实际操作参数，以建立数值模拟。在数值模拟中考虑了辐射传热和聚合物相变。利用五孔皮托管测量了气环上唇处的速度分布，并与数值结果进行了比较。实测结果与数值结果的比较表明，采用STD k - ω湍流模型的模拟精度更高，最小相对绝对误差(RAE)为1.6%。数值计算结果表明，在相同条件下，采用径向射流和长上唇的改进设计的冲击点峰值换热系数(HTC)比原设计高29.1%。增加气环上唇高度，平均HTC比原设计提高了13.4%。
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Pub Date : 2021-07-04DOI: 10.1177/87560879211029693
Fateh Ali, Yanren Hou, M. Zahid, Mamon Rana, M. Usman
The purpose of this article is to provide a mathematical model of magnetohydrodynamic (MHD) non-isothermal flow of an incompressible Jeffrey fluid as it goes through a minimal gap between the two counter rotating rolls. The dimensionless forms of governing equations are obtained by using appropriate dimensionless parameters. The LAT (lubrication approximation theory) is utilized to simplify the dimensionless form of governing equations. Analytical solutions for the velocity, pressure gradient, flow rate, Nusselt number and temperature distribution are presented. How the Jeffrey parameters, MHD and velocities ratio influence on the flow patterns and heat transfer rate are explored. Outcomes of some significant engineering quantities such as flow rate, power input, pressure distribution and roll separation force are obtained numerically in tabular form and some are displayed graphically. We found that the MHD parameter served as a controlling parameter for different engineering quantities like velocity, temperature, flow rate, and coating thickness. Moreover, the coating thickness on the web decreases by increasing the values of velocities ratio.
{"title":"Influence of magnetohydrodynamics and heat transfer on the reverse roll coating of a Jeffrey fluid: A theoretical study","authors":"Fateh Ali, Yanren Hou, M. Zahid, Mamon Rana, M. Usman","doi":"10.1177/87560879211029693","DOIUrl":"https://doi.org/10.1177/87560879211029693","url":null,"abstract":"The purpose of this article is to provide a mathematical model of magnetohydrodynamic (MHD) non-isothermal flow of an incompressible Jeffrey fluid as it goes through a minimal gap between the two counter rotating rolls. The dimensionless forms of governing equations are obtained by using appropriate dimensionless parameters. The LAT (lubrication approximation theory) is utilized to simplify the dimensionless form of governing equations. Analytical solutions for the velocity, pressure gradient, flow rate, Nusselt number and temperature distribution are presented. How the Jeffrey parameters, MHD and velocities ratio influence on the flow patterns and heat transfer rate are explored. Outcomes of some significant engineering quantities such as flow rate, power input, pressure distribution and roll separation force are obtained numerically in tabular form and some are displayed graphically. We found that the MHD parameter served as a controlling parameter for different engineering quantities like velocity, temperature, flow rate, and coating thickness. Moreover, the coating thickness on the web decreases by increasing the values of velocities ratio.","PeriodicalId":16823,"journal":{"name":"Journal of Plastic Film & Sheeting","volume":"83 1","pages":"72 - 104"},"PeriodicalIF":3.1,"publicationDate":"2021-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91235145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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