Vulcanization: Conventional and Dynamic

1995 ◽  
Vol 68 (3) ◽  
pp. 351-375 ◽  
Author(s):  
Aubert Y. Coran
Keyword(s):  
Thermoplastic Elastomers ◽  
Dynamic Vulcanization ◽  
Capital Utilization ◽  
Final Shape ◽  
Fast Processing ◽  
History Of ◽  
The Cost ◽  
Rapid Processing ◽  
Vulcanization Process ◽  
Rubber Article

Abstract Conventional vulcanization, has a history of over 150 years, during which there have been increasing needs for technology to permit more and more rapid processing before the vulcanization of a rubber article in its final shape. But, at the same time, one desired increased rates of crosslinking after the part was in its final shape, e.g., in a mold. These two objectives are opposed to one another. For fast processing, we would like to increase temperatures to reduce the resistance to flow; but we do not want vulcanization to occur before processing flow is complete. On the other hand, after a rubber article is in its final shape or form, we would like for vulcanization to occur as rapidly as possible. The reasons for these objectives, are to increase capital utilization and to reduce the cost of money. The use of the premature vulcanization inhibitor, CTP, can give improved processing safety without loss of vulcanization throughput. In the case of thermoplastic elastomers prepared by dynamic vulcanization, all of the vulcanization is done rapidly during mixing, before the rubber compound flows into its final shape, e.g., during rapid thermoplastic injection molding (in seconds, not minutes). The dynamic vulcanization process does add cost to the material; however, this is more than offset by the gains in capital utilization. I would be remiss if I did not mention some potential disadvantages associated with the thermoplastic elastomers. One of these is that, at temperatures above the temperatures of flow, there is a great reduction in the usefulness of the properties (the materials can melt). A related disadvantage is that resistance to permanent set at high temperatures may be inadequate. However, the elevated-temperature set resistance of thermoplastic elastomers prepared by dynamic vulcanization is generally better than that of those prepared by other means. Both kinds of vulcanization are important and may continue to be so for another 150, or so, years.

Oklahoma!

2020 ◽  
Author(s):  
Tim Carter
Keyword(s):  
Musical Theater ◽  
Final Shape ◽  
Broadway Musical ◽  
History Of ◽  
Rodgers And Hammerstein ◽  
Theatre Guild

Oklahoma! premiered on Broadway on 31 March 1943 under the auspices of the Theatre Guild, and today it is performed more frequently than any other Rodgers and Hammerstein musical. When this book was first published in 2007, it offered the first fully documented history of the making of the show based on archival materials, manuscripts, journalism, and other sources. The present revised edition draws still further on newly uncovered sources to provide an even clearer account of a work that many have claimed fundamentally changed Broadway musical theater. It is filled with rich and fascinating details about the play on which Oklahoma! was based (Lynn Riggs’s Green Grow the Lilacs); on what encouraged Theresa Helburn and Lawrence Langner of the Guild to bring Rodgers and Hammerstein together for their first collaboration; on how Rouben Mamoulian and Agnes de Mille became the director and choreographer; on the drafts and revisions that led the show toward its final shape; and on the rehearsals and tryouts that brought it to fruition. It also examines the lofty aspirations and the mythmaking that surrounded Oklahoma! from its very inception, and demonstrates just what made it part of its times.

This Is an Abridged Account of Delhi Which Is an Old City and One of the Chosen Ones amongst the Cities

2018 ◽  
Author(s):  
Mirza Sangin Beg
Keyword(s):  
Popular Culture ◽  
East India Company ◽  
Ordinary People ◽  
Work Spaces ◽  
History Of ◽  
English East India Company ◽  
Local Traditions ◽  
The Cost ◽  
The City ◽  
Cost Of Construction

The second part of the translation has three segments. The first is dedicated to the history of Delhi from the time of the Mahabharat to the periods of Anangpal Tomar to the Mughal Emperor Humayun as also Sher Shah, the Afghan ruler. In the second and third segments Mirza Sangin Beg adroitly navigates between twin centres of power in the city. He writes about Qila Mubarak, or the Red Fort, and gives an account of the several buildings inside it and the cost of construction of the same. He ambles into the precincts and mentions the buildings constructed by Shahjahan and other rulers, associating them with some specific inmates of the fort and the functions performed within them. When the author takes a walk in the city of Shahjahanabad, he writes of numerous residents, habitations of rich, poor, and ordinary people, their mansions and localities, general and specialized bazars, the in different skills practised areas, places of worship and revelry, processions exemplifying popular culture and local traditions, and institutions that had a resonance in other cultures. The Berlin manuscript gives generous details of the officials of the English East India Company, both native and foreign, their professions, and work spaces. Mirza Sangin Beg addresses the issue of qaum most unselfconsciously and amorphously.

scholarly journals P129 The utility of routine operative swab culture in uncomplicated peri-anal abscesses

BJS Open ◽  
2021 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
Apoorva Khajuria ◽  
Tuba Rahim ◽  
Mariam Baig ◽  
Kai Leong ◽  
Apoorva Khajuria
Keyword(s):  
Inflammatory Bowel Disease ◽  
Perianal Abscess ◽  
Female Ratio ◽  
Incision And Drainage ◽  
Common Presentation ◽  
History Of ◽  
Inflammatory Bowel ◽  
Operative Findings ◽  
The Cost ◽  
Male To Female

Abstract Introduction Despite perianal abscess being a common presentation, certain aspects of its management remain controversial, especially the routine use of intra-operative swab cultures. Methods A retrospective review of patients that underwent incision and drainage procedures for a perianal abscess over a six-month period was undertaken. Results Over 6 months, 50 patients were identified. The male to female ratio was 3:1 and median ASA score was 1. Only 6/50 patients presented with recurrent abscess and 1 patient had history of inflammatory bowel disease. On the basis of operative findings, 39 patients (78%) had uncomplicated abscess (not associated with cellulitis, sinus or fistula); swab cultures were performed in 26 (67%) of these patients. All patients were discharged on the same day; microbiology reports did not impact the treatment and no patients were followed up in clinic post-operatively or presented with recurrence. The number of unnecessary microbiology swabs undertaken in this cohort equates to approximately 52 unnecessary swabs a year. The cost of one swab is £10.10p, which means £520 could potentially be saved annually. Conclusion Routine intra-operative swab cultures do not impact management decisions, add to unnecessary costs and therefore should not be undertaken in uncomplicated or first presentation of peri-anal abscesses.

Empowering and Directive Leadership: The Cost of Changing Styles

2021 ◽  
pp. 227853372110083
Author(s):  
Smita Mukherjee ◽  
Zubin R. Mulla
Keyword(s):  
Laboratory Experiment ◽  
Leadership Styles ◽  
Leadership Style ◽  
Affective Commitment ◽  
Team Outcomes ◽  
History Of ◽  
Satisfaction With The Leader ◽  
The Cost ◽  
First Time

We examine the cost of leaders changing between empowering and directive leadership styles on team outcomes. In a laboratory experiment, we collected data from 240 participants in 80 teams. Confederates enacted different leadership styles and led teams of participants in performing a series of tasks. When leaders changed their style from directive to empowering, teams took time to respond in terms of higher satisfaction with leader and affective commitment. However, when leaders changed their style from empowering to directive, the deterioration of satisfaction with leader and reduction in affective commitment were immediate. Moreover, teams of leaders who had been consistently directive showed higher affective commitment as compared to teams of leaders who had a history of being empowering but later shifted to being directive. First time managers can get inputs on how they should enact their leadership style and be aware that switching between styles may impose long-term costs on the team’s affective commitment and satisfaction with the leader.

scholarly journals Evaluation of whole-body modalities for diagnosis of multifocal osteonecrosis—a pilot study

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Shunichi Yokota ◽  
Keita Sakamoto ◽  
Yukie Shimizu ◽  
Tsuyoshi Asano ◽  
Daisuke Takahashi ◽  
...  
Keyword(s):  
Study Data ◽  
Whole Body ◽  
Hematologic Disease ◽  
Hip Joints ◽  
Patient Demographics ◽  
Examination Time ◽  
History Of ◽  
Body Magnetic Resonance Imaging ◽  
The Cost ◽  
Body Bone

Abstract Background This study aimed to investigate the ability of whole-body bone scintigraphy (WB-BS) in the detection of multifocal osteonecrosis (ON) compared to whole-body magnetic resonance imaging (WB-MRI) and to clarify the characteristics of patients with multifocal ON among those with ON of the femoral head (ONFH) using WB-MRI. Methods Forty-six patients who had symptomatic ONFH and underwent surgery in our hospital from April 2019 to October 2020 were included in the study. Data on patient demographics, including age, sex, body mass index (BMI), history of corticosteroid intake, alcohol abuse, smoking, and symptomatic joints, were collected from their medical records. All patients underwent WB-MRI and WB-BS before surgery. Results The agreement in the detection of ON by WB-MRI vs the uptake lesions by WB-BS in the hip joints was moderate (κ = 0.584), while that in other joints was low (κ < 0.40). Among the 152 joints with ON detected by WB-MRI, 92 joints (60.5%) were symptomatic, and 60 joints (39.5%) were asymptomatic. Twelve out of the 46 (26.0%) patients had multifocal (three or more distinct anatomical sites) ON. Nonetheless, while WB-BS detected symptomatic ON detected by WB-MRI as uptake lesions in 82.6% (76/92) of the joints, asymptomatic ON detected by WB-MRI was detected as uptake lesions in 21.7% (13/60) of the joints. All patients with multifocal ON had a history of steroid therapy, which was significantly higher than that in patients with oligofocal ON (P = 0.035). The patients with a hematologic disease had multifocal ON at a higher rate (P = 0.015). Conclusions It might be difficult for WB-BS to detect the asymptomatic ON detected by WB-MRI compared to symptomatic ON. Considering the cost, examination time, and radiation exposure, WB-MRI might be useful for evaluating multifocal ON. Larger longitudinal studies evaluating the benefits of WB-MRI for detecting the risk factors for multifocal ON are required.

scholarly journals In the service of secrecy: An enveloped history of priority, proof and patents

2021 ◽  
pp. 135918352110288
Author(s):  
Eva Hemmungs Wirtén
Keyword(s):  
Intellectual Property ◽  
Early Modern ◽  
Property System ◽  
Private And Public ◽  
History Of ◽  
The Individual ◽  
Propriété Industrielle ◽  
The Cost ◽  
Double Envelope ◽  
Double Compartment

This article is about an everyday paper object: an envelope. However, as opposed to most other flat paper containers, the enveloppe Soleau can only be bought from L’Institut national de la propriété industrielle (INPI) in Paris. At the cost of €15 you get a perforated, double-compartment envelope allowing you to constitute proof of creation and assign a precise date to your idea or project. But the enveloppe Soleau is something much more than just a simple and cheap way by which you can prove priority in any creative domain. It is a material footprint anchored to centuries of practices associated with disclosure and secrecy, a gateway into the infrastructure of the intellectual property system and its complicated relationship to the forms of knowledge it purports to hold. The purpose of this article is to consider the making of the enveloppe Soleau as a bureaucratic document, a material device performing a particular kind of legal paperwork. In four different vignettes, the article tracks the material becoming of the enveloppe Soleau as an evidentiary receptacle, beginning by going back to early modern practices of secrecy and priority, continuing with its consolidation in two patents (from 1910 and 1911) to the inventor Eugène Soleau (1852–1929), and ending up, in 2016, dematerialized in the e-Soleau. As a bureaucratic document, the enveloppe Soleau shows just how much work a mundane paper object can perform, navigating a particular materiality (a patented double envelope); formalized processes of proof (where perforations have legal significance); the practices of double archiving (in an institution and with the individual) and strict temporal limitations (a decade). Ultimately, the enveloppe Soleau travels between the material and immaterial, between private and public, between secrecy and disclosure, but also between what we perceive of as the outside and inside of the intellectual property system.

Diplomacy Beyond History: Analytic-Violence, Producer-Centred Research, India

2021 ◽  
pp. 097492842098307
Author(s):  
Deep K. Datta-Ray
Keyword(s):  
New Method ◽  
The West ◽  
History Of ◽  
The Right ◽  
Nuclear Diplomacy ◽  
The Cost ◽  
Insight Into

The history of Indian diplomacy conceptualises diplomacy racially—as invented by the West—and restrictively—to offence. This is ‘analytic-violence’ and it explains the berating of Indians for mimicking diplomacy incorrectly or unthinkingly, and the deleting, dismissing, or denigrating, of diplomatic practices contradicting history’s conception. To relieve history from these offences, a new method is presented, ‘Producer-Centred Research’ (PCR). Initiating with abduction, an insight into a problem—in this case Indian diplomacy’s compromised historicisation—PCR solves it by converting history’s racist rationality into ‘rationalities’. The plurality renders rationality one of many, permitting PCR’s searching for rationalities not as a function of rationality but robust practices explicable in producer’s terms. Doing so is exegesis. It reveals India’s nuclear diplomacy as unique, for being organised by defence, not offence. Moreover, offence’s premise of security as exceeding opponent’s hostility renders it chimerical for such a security is, paradoxically, reliant on expanding arsenals. Additionally, doing so is a response to opponents. This fragments sovereignty and abdicates control for one is dependent on opponent’s choices. Defence, however, does not instigate opponents and so really delivers security by minimising arsenals since offence is eschewed. Doing so is not a response to opponents and so maintains sovereignty and retains control by denying others the right to offense. The cost of defence is courage, for instance, choosing to live in the shadow of nuclear annihilation. Exegesis discloses Balakot as a shift from defence to offence, so to relieve the Bharatiya Janata Party’s (BJP) leadership of having to be courageous. The intensity of the intention to discard courage is apparent in the price the BJP paid. This included equating India with Pakistan, permitting it to escalate the conflict, and so imperiling all humanity in a manner beyond history.

Pharmacoeconomic Considerations in Treatment Options for Acute Seizures

1998 ◽  
Vol 13 (1_suppl) ◽  
pp. S27-S29 ◽  
Author(s):  
Nina Graves
Keyword(s):  
Treatment Options ◽  
Emergency Department Visits ◽  
Event Management ◽  
Pharmacoeconomic Data ◽  
Acute Seizures ◽  
Rectal Diazepam ◽  
Adverse Event Management ◽  
History Of ◽  
Cluster Seizures ◽  
The Cost

Two pharmacoeconomic studies on the treatment of acute seizures have been conducted. In 1991, Kriel and colleagues surveyed parents of children with a history of cluster seizures, prolonged seizures, or status epilepticus who had been instructed in the use of rectal diazepam. A comparison of data before instruction with data after instruction showed a reduced need for emergency department visits with rectal diazepam. Instruction thus provided a pharmacoeconomic benefit, despite the cost of the product. In 1996, Marchetti and coworkers found that intravenous fosphenytoin was associated with fewer adverse events than intravenous phenytoin. Fosphenytoin thus reduced the need for adverse event management and provided a substantial pharmacoeconomic benefit, despite its higher cost, compared with phenytoin. This study had a number of limitations, however, and hospital pharmacists remain resistant to the use of fosphenytoin. Additional studies may provide more pharmacoeconomic data to support the greater use of fosphenytoin in the treatment of acute pediatric seizures. (J Child Neurol 1998;13(Suppl 1):S27-S29).

Twelfth-Century Italian Prices: Food and Clothing in Pisa and Venice

1983 ◽  
Vol 7 (4) ◽  
pp. 381-403
Author(s):  
Louise Buenger Robbert
Keyword(s):  
Twelfth Century ◽  
Economic History ◽  
Western Europe ◽  
American Philosophical Society ◽  
Cost Of Living ◽  
Good Opportunity ◽  
History Of ◽  
New Material ◽  
The Cost

Seventy-three years ago pioneer American medievalist Dana Carlton Munro (1911: 504) delivered a paper in Philadelphia to the American Philosophical Society entitled “The Cost of Living in the Twelfth Century.” He threw down the gauntlet by concluding that in this paper an attempt has been made to set forth only a few of the facts, merely to indicate the nature and importance of the problem. Every one of the subjects here discussed is susceptible of elaboration, and needs to be worked out in detail for each country of Western Europe and each period in the twelfth century. The material is voluminous…. This field, as a whole, offers a good opportunity for many monographs, and such work is essential before we can understand the economic history of the century which was most important in the advance of western Europe.This article takes up this challenge with new material on the cost of living in Italy in the twelfth century.

EXPERIMENTAL STUDY ON THE CO2 LASER CUTTING OF NOVEL POLYAMIDE 6/FLUOROELASTOMER THERMOPLASTIC ELASTOMERIC BLENDS

2015 ◽  
Vol 88 (1) ◽  
pp. 125-137 ◽  
Author(s):  
Shib Shankar Banerjee ◽  
Anil K. Bhowmick
Keyword(s):  
Low Power ◽  
Co2 Laser ◽  
Process Parameters ◽  
Laser Power ◽  
Laser Cutting ◽  
Manufacturing Industry ◽  
Cutting Speed ◽  
Polyamide 6 ◽  
Thermoplastic Elastomers ◽  
Dynamic Vulcanization

ABSTRACT The application of the low-power CO2 laser-cutting process to fluoroelastomer (FKM), polyamide 6 (PA6), PA6/FKM thermoplastic elastomers (TPEs), and their thermoplastic vulcanizate (TPV) is reported. The main laser process parameters studied were laser power, cutting speed, and material thickness. The value of the top and bottom widths of the slit that were formed during laser cutting (kerf width), melted transverse area, and melted volume per unit time were measured and analyzed. Interestingly, TPE showed a smaller melted area and melted volume per unit time when compared with those values with PA6. Dynamic vulcanization further decreased these values. For example, the melted areas of PA6 and TPE were 510 × 10−3 mm2 and 305 × 10−3 mm2, respectively, which reduced to 238 × 10−3 mm2 for TPV at 40 W laser power. FKM showed the lowest value (melted area of 180 × 10−3 mm2). In addition, the output quality of the cut surface was examined by measuring the root mean square (RMS) roughness of the cut edges and heat-affected zone (HAZ). The obtained results indicated that the dimension of the HAZ and RMS roughness largely decreased in TPE when compared with PA6. For example, the HAZ of PA6 was 700 μm, which decreased to 230 μm for TPE at 40 W laser power. On the other hand, HAZ was nonexistent for FKM. Infrared spectroscopic analysis showed that there was no structural change of TPE or pristine polymers after applying the low-power CO2 laser on the surface of materials. CO2 laser cutting will be a new technique in this industry, and this analysis will assist the manufacturing industry to choose a suitable laser system with exhaustive information of process parameters for cutting or machining of rubber, TPEs, and TPVs.

Sign in / Sign up

Export Citation Format

Share Document