bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Analysis of Core Crushing and Core Movementin RTM and SRIM Foam Cored Composite Parts
Authors: Wirth Stephane , Gauvin Raymond , Kendall Ken 
Published: July 2017

In liquid composite molding, SRIM can typically achieve a higher pressure than the RTM process. When molding a foam cored composite part at high flow rates using an SRIM system, the following related effects can be observed: high molding pressures, core shifting, core crushing, variable permeability and reinforcement compaction. Because of the variable permeability in such conditions, the linear Darcy law does not apply for flow simulation. Finally, all this can easily result in dry spot defects. To study the various problems occurring in the molding of foam cored composite parts, two molds equipped with pressure transducers were used. The first one was a picture frame square plaque mold. To ease the measurement of reinforcement compaction and core crushing, flat panels were molded with reinforcement on one side only. The second part was a quasi-rectangular foam cored beam with braided reinforcement all around the foam core. In this paper, it is refered as the Small Core part. With this part, reinforcement compaction, core crushing and core shifting was measured. The picture frame plaque mold was used with the RTM and SRIM processing equipment. Continuous strand mat with a constant fiber volume fraction was used with polyurethane foam of variable density. For the RTM process, Vinyl Ester resin was injected at constant pressure while for SRIM, Polyurethane resin was injected at constant flow rate. Parts were cut to measure laminate thickness and core deformation. For the Small Core mold, only the SRIM system was used with a constant flow rate. In this case the core materials used were Polyurethane of various densities. All parts were braided with ±45 and axial (0°) glass filaments. For some parts, locators were placed on the core surface to prevent its shifting. Short shots were used to observe the resin flow progression. For the picture frame experiments, the RTM process gave no significant core deformation. With the SRIM system, results showed a non-negligible core deformation at some foam densities. The SRIM system was also used with the Small Core tool. The results revealed the dominance of the core shifting and fabric compaction over core crushing. The use of locators placed on the core surface led to a better flow progression and nearly eliminated the core shifting, resulting in a part without defects. The flow simulation software RTMFLOT developed in our laboratory and based on a linear Darcy Law was used with these complex cases. The simulation results gave a good approximation of the gate pressure during filling.
Analysis and Modeling of the Residence Time Distribution in Intermeshing Co-rotating Twin Screw Extruders Based on Finite Element Simulations
Authors: Potente H. , Flecke J. 
Published: July 2017

In the field of compounding and reactive extrusion the residence time distribution, among other factors, represents an important factor for the evaluation of the process behavior in co-rotating twin screw extruders. The corresponding literature presents us with a lot of publications regarding this subject. Mostly, these are empirical approaches to describe the residence time behavior or more experimental analyses. The existing description forms are often taken from the single-screw theory and are applied to the twin screw extruder. This paper is meant to present a new analysis and description of the residence time behavior of a co-rotating twin screw extruder which is based on 3-D finite element simulation for power law fluids. The residence time is thus determined and evaluated by means of streamlines taken from flow simulation. As a result the existing description formulations compared with experimental data for the operating parameters needed in practice are mostly out of the extent of validity. This is due to the high speed with a pre-defined melt throughput and the exceptional channel geometry of the tightly intermeshing co-rotating twin screw extruder.
Experimental Study of Extruding Behavior against Material Property in the Filler Mixing by Intermeshing Co-Rotating Twin Screw Extruder (II)
Authors: Ishibashi J. , Kobayashi A. , Yoshikawa T. 
Published: July 2017

Plastics mixed with mineral fillers are extensively used in various fields. Co-rotating twin screw extruder are generally used as a compounder for mixing plastics with filler. In ANTEC '96, we presented the study about the feeding system which supplies resin and filler together in the filler compounding by co-rotating twin screw extruder (hereinafter TSE) [1]. The present study investigated extruding behavior in the side-feeding system of filler compounding by TSE. This study verified by experiment how the MFR of polypropylene (hereinafter PP), the particle size and the mixing ratio of talc influence on the extruding capacity. Results of experiment indicated that the higher mixing ratio and the smaller particle size of talc made throughput rate lower. On the other hand, difference in the MFR of PP was found to have a little influence. Amount of the air contained in the talc was found to have great influence on the throughput rate.
Reliability of sequential systems using the cause—consequence diagram method
Authors: Andrews J D , Ridley L M 
Published: July 2017

In many industrial systems, where safety is of the utmost importance, it is necessary that expedient tools for accident analysis are available and employed at the design stage. Such tools must be able to handle large systems in a systematic way and display the factors that are of vital importance for the functionality of the system. The technique of fault tree analysis (FTA) is commonly used to assess the failure probability of such systems. The fault tree represents the failure logic of the system in an inverted tree structure and has the advantage that it provides very good documentation of the way the failure logic was developed. Conventional fault tree quantification requires a number of assumptions regarding the system. One of these is that the basic events in the tree occur independently. This condition is not satisfied when sequential failures are encountered. Employing alternative methods, such as Markov methods, can result in the loss of the documentation that represents the failure logic of the system. The cause-consequence diagram method is a tool that, like fault tree analysis, documents the failure logic but has the extra capability enabling the analysis of systems subject to sequential failures. In addition, the cause-consequence diagram identifies the complete set of system responses to any given initiating event. This paper is concerned with the cause-consequence diagram method and its application to sequentially operating systems. It extends previous work by providing more rigorous guidelines to enable the construction of the diagram and an analysis methodology that can be used when dependencies exist between the events featured in the decision boxes. A new symbol distinguishing between events that exist at a specified point in time and those that occur at that time is introduced to facilitate the analysis.
Maintenance modelling for computer-based systems
Authors: Meshkat L , Dugan J B , Andrews J 
Published: July 2017

A framework is presented for incorporating maintenance into a dependability analysis methodology for computer-based systems. Two types of maintenance are considered: failure-driven maintenance and time-driven maintenance. Failure-driven maintenance or repair is carried out when the system (or component) performance deviates from its expected performance and consists of all tasks performed to restore the functional capabilities of failed items, principally diagnosis and repair. Time-driven or scheduled maintenance is conducted on a specific time schedule in order to prevent system failure. There may be dependencies between different components of a system with regard to their maintenance plans. These dependencies arise either because a component has maintenance priority over one or more components or because the maintenance of a certain component implies the maintenance of other components. Constructs are presented for modelling these dependencies in the context of dynamic fault tree analysis and a methodology is developed for solving the fault tree. The dynamic fault tree constructs effectively capture the failure dependencies between components. The approach is illustrated with an example based on a water deluge system.
Foreign Policy Issues Before the New Government: The Sri Lanka Problem
Authors: Gangal S. C. 
Published: July 2017

Sri Lanka's ethnic problem—the problem of the political and socioeconomic status and related questions concerning the large number of Tamil settlers in its northern and eastern districts—dates from the time that India and Sri Lanka (earlier called Ceylon) got their independence in the late forties, or even earlier. The Tamils in Sri Lanka have contributed greatly to the country's tea plantations and industry and have made many other useful inputs into the island's economy. But they have, for long, been subjected to innumberable disabilities—such as lack of full civil and property rights, non-assimilation into the national mainstream and even statelessness—and have been the target of periodic violence and killings. In order to protect themselves from these orgies of violence and to advance their legitimate interests, they have, from time to time, formed various associations or organizations. Of these, the Tamil United Liberation Front (TULF) — currently led by A. Amirthalingam — has been about the most organized and well-known at home and abroad. In view of the fact that generally the Tamils had migrated from India during the past seven or eight decades, they tend to look up to India for sympathy and moral and material support during periods of crisis, severe harrassment and violence. By the same token—and also on account of its concern for peace and good neighbourly relations in the region—the Government and people of India could not be totally unconcerned about developments touching on this problem. Most recently, President Zail Singh expressed this concern in his address to the joint sitting of the two Houses of Parliament on 17 January 1985: “The ethnic violence in Sri Lanka is a matter of deep concern to us. We are convinced that use of force cannot lead to a solution. A political process, in which all the concerned parties are involved, can alone lead to a just settlement. Conditions must be created in Sri Lanka to enable the return of the large number of refugees (estimated to be over 40,000) who have been forced to take shelter in India.” A week earlier, the Sri Lankan Minister of Rural Industries, S. Thondaman had met Prime Minister Rajiv Gandhi, who reportedly took the opportunity to express his concern at the continuing violence and tension-prone situation in Sri Lanka.
Lichen Planopilaris-Like Changes Arising within an Epidermal Nevus: Does This Case Suggest Clues to the Etiology of Lichen Planopilaris?
Authors: Smith Kathleen J. , Crittenden Jacob , Skelton Henry 
Published: July 2017

Background: Lichen planopilaris shows a perifollicular lymphocytic infiltrate at the level of infundibulum and the isthmus of the hair bulge resulting in necrotic changes within keratinocytes and eventually hair loss. Objective: We present a 14-year-old black male with a history of a raised epidermal lesion on the scalp that was present at birth. Over the past few years, the patient developed gradual hair loss and increased verrucous changes of the skin within the original lesion. Histologic sections of the area showed features consistent with an epidermal nevus peripherally, with a central area showing some features characteristic of those seen in lichen planopilaris. In addition, there was marked hyperkeratosis with increased yeast and bacteria within the follicles. Conclusions: Initiating factors in lichen planopilaris are not well defined. Overgrowth of microorganisms with hyperkeratosis results in factors that disrupt the immune privilege of the hair follicle, leading to an immunologic reaction that is limited to the follicle and spares surrounding eccrine structures. This case suggests possible mechanisms involved in the induction of lichen planopilaris.
The Impact of Foot Complications on Health-Related Quality of Life in Patients with Diabetes
Authors: Price Patricia , Harding Keith 
Published: July 2017

Background: The concept of health-related quality of life (HRQoL) has been the focus of much debate in recent years. However, within diabetes the focus has centred on the behavioural adaptation to a chronic disease state. The impact of foot complications is witnessed regularly in the clinical setting; amputation in this group is usually preceded by ulceration and a worsening cycle of foot problems. Objective: This review sets out to investigate the literature on foot complications in those with diabetes, to assess the cost to the individual in terms of impact on everyday living. Conclusion: The literature on the specific impact of foot complications is limited, but indicates a situation in which those with diabetic foot ulceration may have an even poorer HRQoL than those who have experienced an amputation related to diabetes. In order to assess the full impact of new treatments or therapeutic interventions, it is vital that further research is conducted in this area.
The Morbid Anatomy of the Dermatologic Genome: An Update for the Third Millennium
Authors: Bale Sherri J. 
Published: July 2017

Background: Much progress has been made in recent years in the identification of genes underlying many hereditary skin diseases. Objective: To provide an update on the status of the identification of genes involved in hereditary skin disorders and to compare the current standing with that in the last decade. Methods: A review of the literature is presented here in a series of lists describing the chromosomal location, specific gene, clinical relevance, and availability of molecular-based genetic tests for each genodermatosis. Results: Progress has been made in identifying the genes underlying many disorders of cornification, genodermatoses with malignant potential, bullous disorders, pigmentary disorders, disorders affecting the epidermal appendages and the dermis, and other miscellaneous genodermatoses. Conclusion: The great progress made toward the completion of the human gene sequence and the continued efforts of many clinical and molecular scientists to identify disease genes will make diagnosis of hereditary dermatological disorders more precise and allow accurate family counseling as well as possibly leading to more targeted therapies during this millennium.
Alopecia Areata Universalis in an Infant
Authors: LaRow Jo Anne , Mysliborski Judith , Rappaport I. Paul , Rouleau Guy A. , Carlson J. Andrew 
Published: July 2017

Background: Alopecia areata (AA) is common during childhood and rarely reported in infants. The four reported cases of AA in infants all exhibited circumscribed patches of alopecia that appeared at birth or shortly thereafter. Objective: We report a case of alopecia areata universalis that developed after birth along with fingernail changes of shortening (onychomadesis) and onycholysis. Scalp biopsy at 2 years of age revealed rare, intermediate, terminal follicles in catagen associated with sparse peribulbar lymphocytic infiltrates. Results: This constellation of clinicopathologic features was interpreted as AA. We discuss the differential diagnosis of generalized alopecia in healthy infants, in particular, Clouston's syndrome, a hair-nail (hidrotic) ectodermal dysplasia found in this region. Genetic testing for linked polymorphisms to the Clouston gene locus were negative in this child and his parents. Conclusions: Alopecia areata should be included in the differential diagnosis of generalized alopecia presenting at or shortly after birth. For purposes of genetic counseling and prognosis, it is crucial that a correct diagnosis be made.
The Role of Psychological Stress in Skin Disease
Authors: Kimyai-Asadi Arash , Usman Adil 
Published: July 2017

Background: Numerous case reports and studies have suggested that psychological stress may have a role in the onset or exacerbation of a variety of skin diseases. Objective: We review the literature pertaining to the role of psychological stress in the exacerbation of psoriasis, urticaria, eczematous dermatitis, herpesvirus infections, and other skin diseases; discuss potential mechanisms of stress-induced skin disease; and review studies and case reports of psychotherapeutic interventions that have been found helpful in the therapy of skin diseases. Conclusions: There is evidence linking psychological stress to exacerbation of certain skin diseases. Both the clinical and the basic science evidence, however, can be hard to interpret in light of the difficulty of defining and quantifying psychological stress as well as the questions regarding the etiologic significance of neuroimmunologic findings in skin diseases.
Nonsteroidal Antiinflammatory Drug-Induced Pseudoporphyria: A Case Series
Authors: LaDuca Jeffrey R. , Bouman Peter H. , Gaspari Anthony A. 
Published: July 2017

Background: Pseudoporphyria is a diagnosis that is used when porphyria-like clinical lesions arise in the setting of normal porphyrin levels. This condition was first described in the 1960s and was initially related to the use of certain antibiotic drugs. In 1985, pseudoporphyria was first attributed to the use of nonsteroidal antiinflammatory drugs (NSAIDs). Subsequently, a host of NSAIDs and other drugs have been found to elicit the same clinical entity. The exact mechanism by which certain drugs create clinical lesions resembling porphyria cutanea tarda or erythropoietic protoporphyria is still unknown. A phototoxic mechanism is hypothesized. Objective: We describe six patients diagnosed with pseudoporphyria and detail the diagnostic tests leading to the eventual diagnosis. Results: The patients ranged in age from 27 to 59 years and had a female:male predominance of 2:1. The offending NSAID was DayPro (oxaprozin) for three of the patients, Relafen (nabumetone) for two of the patients, and Aleve (naproxen) for one patient. For each patient, histology and immunofluorescence was either consistent with the diagnosis of porphyria cutanea tarda or nonspecific, while serum, stool, and urine porphyrins did not support that diagnosis. Withdrawal of the offending agent provided relief from the clinical symptoms for each patient. None of our patients were rechallenged with the putative offending drug. However, prolonged avoidance has provided a sustained remission from symptoms in all six patients. Conclusions: Pseudoporphyria is a relatively rarely reported condition. Clinical suspicion with appropriate laboratory and histopathologic findings help to make this diagnosis, and exclude true porphyrias. Rechallenge with the offending drug to produce symptom relapse has been proposed to be helpful in confirming this diagnosis of exclusion. Since all 6 patients with drug-induced pseudoporphyria experienced resolution of their symptoms after discontinuing the offending agent, we propose that this clinical correlation alone is sufficient to confirm this diagnosis. Our observation of six new cases of NSAID-induced pseudoporphyria over a two-year interval suggests that this is not a rare entity.
Cutaneous Manifestations of Eating Disorders
Authors: Tyler Ingrid , Wiseman Marni C. , Crawford Richard I. , Birmingham C. Laird 
Published: July 2017

Background and Objective: No complete review of the cutaneous manifestations of eating disorders exists. We therefore, set out to review and systematically describe the clinical and histopathologic features of dermatologic conditions associated with anorexia nervosa, bulimia nervosa, and obesity. Differential diagnosis, pathophysiology, laboratory studies, and treatment are also reviewed. Methods: Index Medicus review (1966 to present) using Ovid-MEDLINE. Search terms included eating disorders, anorexia nervosa, bulimia nervosa, eating disorders not otherwise specified (ED-NOS), and obesity, as well as the terms dermatology skin and cutaneous manifestations, with cross-referencing sources. These were combined with our own clinical experience. All relevant publications, including case reports, case series, cohort studies, and histopathologic studies giving at least Level II-3 evidence (evidence from comparisons between times or places with or without the intervention, including dramatic results in uncontrolled experiments), were selected. Conclusions: Forty dermatological signs have been reported in eating disorder patients. Eating disorders have many cutaneous manifestations and cutaneous signs may lead to the diagnosis of an occult eating disorder. The resolution of skin eruptions in eating disorder patients often depends on treatment of the underlying disorder.
Do the Physical and Histologic Features and Time Course in Acute Generalized Exanthematous Pustulosis Reflect a Pattern of Cytokine Dysregulation?
Authors: Smith Kathleen , Norwood Christopher , Skelton Henry 
Published: July 2017

Background: Acute generalized exanthematous pustulosis (AGEP) is characterized by fever and an indurated erythematous eruption early, with the development of nonfollicular pinhead sterile pustules on an erythematous background. The eruption progresses and resolves relatively rapidly. Although drugs are believed to be the major etiologic agents, other immune modulators, including infections, heavy metals, and radiation, have been implicated. Objective: The purpose of this study was to document underlying diseases in patients with AGEP and to determine if this data and the histologic features suggested an underlying pattern of immune dysregulation. Methods: Twenty-one patients with new or recurrent episodes of AGEP were questioned concerning underlying diseases. The histopathologic features seen in the biopsy sections and the approximate time of biopsy during the course of their eruptions were recorded. Results: Two patients had a history of psoriasis and one patient had a family history of psoriasis, two patients had diagnoses of sarcoid, two patients had inflammatory bowel disease, one had autoimmune thyroiditis, and one patient had multiple sclerosis. Biopsies done at the onset of the eruption showed marked to moderate papillary dermal edema and a mixed dermal inflammatory infiltrate. Shortly thereafter, biopsies showed spongiform pustules within the epidermis and occasional dyskeratotic cells with residual perivascular dermal edema. Although no definitive vasculitis was seen, there was leukocytoclasis within the dermal infiltrate in the majority of biopsy specimens performed more than 48 hours after the onset of the eruption. Conclusion: The histologic features seen in AGEP and the disease associations suggest that patients who develop this eruption may have an underlying tendency for development of a pattern of immune dysregulation characterized by a T helper-1 cytokine pattern.