scholarly journals Role of Fiber Morphology in Thermal Bonding

2002 ◽  
Vol os-11 (3) ◽  
pp. 1558925002OS-01
Author(s):  
Subhash Chand ◽  
Gajanan S. Bhat ◽  
Joseph E. Spruiell ◽  
Sanjiv Malkan
Keyword(s):  
Molecular Orientation ◽  
Bonding Temperature ◽  
Scale Up ◽  
Optimum Process ◽  
Process Conditions ◽  
Staple Fiber ◽  
Fiber Morphology ◽  
Thermal Bonding ◽  
Wide Range

The role of fiber morphology in a thermal point bonding operation was investigated. Primary objectives were to understand the changes taking place in fiber structure due to applied heat and pressure, and the role of fiber morphology in determining optimum process conditions and properties of the webs. To study fibers with varying morphology, i.e., from partially drawn as in spunbonding to fully drawn as in staple fiber nonwovens, fibers with a wide range of crystallinity and orientation were spun and characterized, from two polypropylene resins. Thermally bonded carded webs were produced, using these fibers, and characterized in order to understand thermal bonding behavior of fibers with different morphology. The fibers with different morphology differed significantly in their bonding behavior. The fibers with higher molecular orientation and crystallinity tended to form a weak and brittle bond due to lack of polymer flow and fibrillation of the fibers in the bonded regions. In general, fibers with lower molecular orientation and lower crystallinity yielded stronger and tougher webs. Fibers with relatively less developed morphology also exhibited lower optimum bonding temperature. Morphological changes in fibers were observed during the thermal bonding process, in bonded as well as unbonded regions of the web. As a final step to see how the observations from staple-fiber study translate to one of the relevant processes during scale-up, spunbond studies were also conducted in a similar way.

New Technology and Developments in Compound Semiconductor Vertical RDR-MOCVD Growth Systems

1994 ◽  
Vol 340 ◽  
Author(s):  
M. McKee ◽  
G.S. Tompa ◽  
P.A. Zawadzki ◽  
A. Thompson ◽  
A. Gurary ◽  
...  
Keyword(s):  
New Technology ◽  
Chemical Vapor ◽  
Rotating Disk ◽  
Easy Access ◽  
Organic Chemical ◽  
Optimum Process ◽  
Process Conditions ◽  
Monitoring And Control ◽  
Large Area ◽  
Wide Range

ABSTRACTCompound semiconductors are at the heart of todays advanced digital and optoelectronic devices. As device production levels increase, so too does the need for high throughput deposition systems. The vertical rotating disk reactor (RDR) has been scaled to dimensions allowing metal organic chemical vapor deposition (MOCVD) on multiple substrates located on a 300 mm diameter platter. This symetric large area reactor affords easy access over a wide range of angles for optical monitoring and control of the growth process. The RDR can be numerically modeled in a straightforward manner, and we have derived scaling rules allowing the prediction of optimum process conditions for larger reactor sizes. The material results give excellent agreement with the modeling, demonstrating GaAs/AlAs structures with <±0.9% thickness uniformities on up to 17-50mm or 4-100mm GaAs substrates. Process issues related to reactor scaling are reviewed. With high reactant efficiencies and short cycle times between growths, through the use of a vacuum loadlock, the costs per wafer are found to be dramatically less than in alternative process reactors. The high reactant utilization, in combination with a dedicated and highly efficient exhaust scrubbing system, minimizes the systems environmental impact.

scholarly journals Using an acoustic levitator to investigate the drying kinetics and solids forming process of individual droplets during spray drying

2020 ◽  
Author(s):  
Ramona Huelsmann ◽  
Guenter J. Esper ◽  
Reinhard Kohlus
Keyword(s):  
Surface Temperature ◽  
Spray Drying ◽  
Scale Up ◽  
Small Sample ◽  
Drying Kinetics ◽  
Process Conditions ◽  
Drying Process ◽  
Real Process ◽  
Wide Range ◽  
Acoustic Levitator

AbstractSpray drying is a widely used process to turn slurries into dry powders and is especially important for thermally-sensitive materials, that are often found in the food or pharmaceutical industry. However, detailed insight into the drying kinetics during spray drying is difficult to investigate due to the boundary conditions in a spray drying tower. As a result, there is a lack of important information on the drying process and subsequent solidification of individual droplets. In this context, an experimental setup for a droplet positioned in a stationary ultrasonic field of an acoustic levitator is designed to enable a non-contacting measurement of the drying kinetics and the subsequent solidification process. To generate a comparable situation like in a real spray drying process, the droplet is positioned in an airflow, where air temperature, humidity, and velocity can be adjusted over wide range. Using an infrared camera to measure the surface temperature and a Complementary Metal Oxide Semiconductor (CMOS) camera for object recognition, the droplet can be observed continuously and drying kinetics of the droplet can be determined from the measured surface temperature and decreasing droplet size. Result of a 10 wt.% aqueous micro particle TiO2 suspension are reported and show that the investigated method is a very valuable and fast tool to safely scale-up spray drying systems very close to real process conditions. Especially when only small sample amounts are available in an early development stage.

Evaluation of Manufacturing Technology and Characterization of Composite Fabric for Stab Resistant Materials

2008 ◽  
Vol 55-57 ◽  
pp. 429-432 ◽  
Author(s):  
Chia Chang Lin ◽  
Ching Wen Lou ◽  
Wen Hao Hsing ◽  
W.H. Ma ◽  
Chin Mei Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bonding Temperature ◽  
Polyamide 6 ◽  
Primary Component ◽  
Bonding Process ◽  
Woven Fabric ◽  
Process Conditions ◽  
Thermal Bonding ◽  
Needle Punching ◽  
Stab Resistance

d more to their own safety, lead all kinds of personal protection apparatus to rapidly develop. This study designed and manufactured the stabbing resistant fabrics to prevent the pricking damage of human body. In this study, woven Kevlar fabric is laid between two layers of polyamide 6 fibrous webs that contain low-melt polyester fibers. The fibrous webs and woven fabric are bonded via needle punching and thermal bonding to generate a nonwoven/woven composite fabric that can be used as a substrate for artificial leather. The polyamide 6 staple fiber is the primary component of the nonwoven structure. The low-melt polyester fiber was added via thermal bonding to reinforce the composite fabric structure. The stab resistance of the composite fabric was reinforced by the woven Kevlar fabric. Because the bonding process alters the mechanical properties of the composite fabric, effects of bonding process conditions, such as needle punching density and thermal bonding temperature, on the mechanical properties and stab resistance of the composite fabric were investigated. The stab resistance of the composite fabric was assessed by stab resistance tests using the ASTM F1432 standard. Experimental results demonstrate that the optimal parameters obtained from sample which needle punching density is 200 needles/cm2

scholarly journals Reimagining the role of the nursing workforce in Uganda after more than a decade of ART scale-up

2020 ◽  
Author(s):  
Henry Zakumumpa
Keyword(s):  
Disease Management ◽  
Scale Up ◽  
Task Shifting ◽  
Health Facilities ◽  
Hiv Care ◽  
Scope Of Practice ◽  
Nursing Workforce ◽  
Hiv Disease ◽  
Wide Range

Abstract Background The expanding roles and increasing importance of the nursing workforce in health services delivery in resource-limited settings is not adequately documented and sufficiently recognized in the current literature. Drawing upon the theme of 2020 as the international year of the Nurse and Midwife, we set out to describe how the role of nurses expanded tremendously in health facilities in Uganda during the era of anti-retroviral therapy (ART) scale-up that commenced in June 2004.Methods We employed a mixed-methods sequential explanatory research design. Phase One entailed a cross-sectional health facility survey (n=195) to assess the extent to which human resource management strategies (such as task shifting) were common. Phase Two entailed a qualitative multiple case-study of 16 (of the 195) health facilities for an in-depth understanding of the strategies adopted (e.g. nurse-centred HIV care). Descriptive analyses were performed in STATA (v 13) while qualitative data were analyzed by thematic approach.Results We found that nurses were the most represented cadre of health workers involved in the overall leadership of HIV clinics across Uganda. Most nurse-led HIV clinics were based in rural settings however this trend was fairly even across setting (rural/urban/peri-urban). While 181(93%) health facilities allowed non-physician cadre to prescribe ART, a number of health facilities (n=36) or 18% deliberately adopted nurse-led HIV care models. Nurses were empowered to be multi-skilled with a wide range of competencies across the HIV care continuum right from HIV testing to mainstream clinical HIV disease management. In several facilities, nursing cadre were the backbone of ART service delivery. A select number of facilities devised differentiated models of task shifting from physicians to nurses in which the latter handled patients who were stable on ART. Conclusion Overall, our study reveals a wide expansion in the scope-of-practice of nurses during ART scale-up in Uganda. Nurses were thrust in roles of HIV disease management that were traditionally the preserve of physicians. Our study underscores the importance of reforming regulatory frameworks governing nursing workforce scope-of-practice such as the need for developing a policy on task shifting which is currently lacking in Uganda.

SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

1977 ◽  
Vol 35 ◽  
pp. 308-309
Author(s):  
K. W. Robinson
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Strength Properties ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Pure Cellulose ◽  
Short Rotation ◽  
Hardwood Trees ◽  
Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

Electron microscopy study of reactively sputter-deposited Ti/N films on silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1362-1363
Author(s):  
V. C. Kannan ◽  
A. K. Singh ◽  
R. B. Irwin ◽  
S. Chittipeddi ◽  
F. D. Nkansah ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Hexagonal Phase ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Process Conditions ◽  
Tin Films ◽  
Wide Range ◽  
Fcc Phase ◽  
Circuits Vlsi

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

Introduction: Emotion, History and the Arts

2018 ◽  
Vol 7 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Erin Sullivan ◽  
Marie Louise Herzfeld-Schild
Keyword(s):  
Historical Change ◽  
Carson Mccullers ◽  
Emotional Life ◽  
Review Section ◽  
The Arts ◽  
Wide Range ◽  
War Correspondents ◽  
History Of ◽  
Johan Huizinga

This introduction surveys the rise of the history of emotions as a field and the role of the arts in such developments. Reflecting on the foundational role of the arts in the early emotion-oriented histories of Johan Huizinga and Jacob Burkhardt, as well as the concerns about methodological impressionism that have sometimes arisen in response to such studies, the introduction considers how intensive engagements with the arts can open up new insights into past emotions while still being historically and theoretically rigorous. Drawing on a wide range of emotionally charged art works from different times and places—including the novels of Carson McCullers and Harriet Beecher-Stowe, the private poetry of neo-Confucian Chinese civil servants, the photojournalism of twentieth-century war correspondents, and music from Igor Stravinsky to the Beatles—the introduction proposes five ways in which art in all its forms contributes to emotional life and consequently to emotional histories: first, by incubating deep emotional experiences that contribute to formations of identity; second, by acting as a place for the expression of private or deviant emotions; third, by functioning as a barometer of wider cultural and attitudinal change; fourth, by serving as an engine of momentous historical change; and fifth, by working as a tool for emotional connection across communities, both within specific time periods but also across them. The introduction finishes by outlining how the special issue's five articles and review section address each of these categories, while also illustrating new methodological possibilities for the field.

Short Films from a Small Nation

2018 ◽  
Author(s):  
C. Claire Thomson
Keyword(s):  
Public Information ◽  
Industrial Process ◽  
Actor Network Theory ◽  
Documentary Films ◽  
Wide Range ◽  
Short Films ◽  
Post War ◽  
The 1960S ◽  
Art And Architecture

The first book-length study in English of a national corpus of state-sponsored informational film, this book traces how Danish shorts on topics including social welfare, industry, art and architecture were commissioned, funded, produced and reviewed from the inter-war period to the 1960s. For three decades, state-sponsored short filmmaking educated Danish citizens, promoted Denmark to the world, and shaped the careers of renowned directors like Carl Th. Dreyer. Examining the life cycle of a representative selection of films, and discussing their preservation and mediation in the digital age, this book presents a detailed case study of how informational cinema is shaped by, and indeed shapes, its cultural, political and technological contexts.The book combines close textual analysis of a broad range of films with detailed accounts of their commissioning, production, distribution and reception in Denmark and abroad, drawing on Actor-Network Theory to emphasise the role of a wide range of entities in these processes. It considers a broad range of genres and sub-genres, including industrial process films, public information films, art films, the city symphony, the essay film, and many more. It also maps international networks of informational and documentary films in the post-war period, and explores the role of informational film in Danish cultural and political history.

Quantitative and Qualitative Methods of Studying the Processes of Socialization of a Modern Teenager

2020 ◽  
pp. 102-109
Author(s):  
Svetlana Alekseevna Raschetina ◽  
Keyword(s):  
Research Methods ◽  
Interpersonal Relations ◽  
Internet Communication ◽  
Socialization Process ◽  
Wide Range ◽  
The Family ◽  
Modern Family ◽  
Making Friends ◽  
Main Support

Relevance and problem statement. Modern unstable society is characterized by narrowing the boundaries of controlled socialization and expanding the boundaries of spontaneous socialization of a teenager based on his immersion in the question arises about the importance of the family in the process of socialization of a teenager in the conditions of expanding the space of socialization. There is a need to study the role of the family in this process, to search, develop and test research methods that allow us to reveal the phenomenon of socialization from the side of its value characteristics. The purpose and methodology of the study: to identify the possibilities of a systematic and anthropological methodology for studying the role of the family in the process of socialization of adolescents in modern conditions, testing research methods: photo research on the topic “Ego – I” (author of the German sociologist H. Abels), profile update reflexive processes (by S. A. Raschetina). Materials and results of the study. The study showed that for all the problems that exist in the family of the perestroika era and in the modern family, it acts for a teenager as a value and the first (main) support in the processes of socialization. The positions well known in psychology about the importance of interpersonal relations in adolescence for the formation of attitudes towards oneself as the basis of socialization are confirmed. Today, the frontiers of making friends have expanded enormously on the basis of Internet communication. The types of activities of interest to a teenager (traditional and new ones related to digitalization) are the third pillar of socialization. Conclusion. The “Ego – I” method of photo research has a wide range of possibilities for quantitative and qualitative analysis of the socialization process to identify the value Pillars of this process.

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