bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Transmission of Ideas in the Use of Fossils in Stratigraphic Analysis from England to America 1800-1840
Authors: Torrens H. 
Published: April 2015

Transmission from the Old to the New World, by means other than publication, of the idea that fossils could help in the analysis of stratigraphic problems is discussed, over the period 1800 to 1840. Focus on the single direction of transmission from England to America does not imply that this was either the only or the most important route by which such ideas came to North America.The contribution of William Smith, and his pupil John Farey, is first briefly reviewed in this context. Until their elucidation of an adequate Standard of sequential lithological units in England, no practical transmission of the idea that fossils could help in stratigraphy was possible. Smith's contacts with American visitors are then discussed but the first migrant informed about the ‘new stratigraphy’ was Henry Steinhauer, a Moravian missionary who emigrated to Philadelphia in 1815. He came direct from the Bath circles in which a knowledge of Smith's results was commonplace. As an even more important link in the chain of transmission, Steinhauer took his own large fossil collection with him, arranged in Standard Smithian stratigraphic order. The next such migrant was John Finch, who arrived in America in 1823 to escape his many English creditors! His success in comparing English and Atlantic coast sequences based on fossils is reviewed. Others like Professor William Buckland, who had been brought up as a Smithian stratigrapher, were also then busy in England comparing such sequences, helped, in Buckland's case, by the geologically inclined Martha Hare, aunt of Professor Robert Hare in Pennsylvania. The contribution of two of Smith's own trans-Atlantic pupils, G.W. Featherstonhaugh and R.C. Taylor, is discussed in a final section. Taylor emigrated to North America in 1831, again taking his large fossil collection, arranged in Smithian stratigraphic order, with him. He took it with the specific intention that it be used to advance correlations between America and England.The arrival of such good collections of stratigraphically arranged fossils could have been a most important link in the chain of transmission of ideas in this field. More research is needed at the American end, in particular to discover what survives of the collections of these early scientific migrants.
Evaluating the Effectiveness of AMC Control Strategies with Reactivity Monitoring
Authors: Muller Chris 
Published: April 2015

The control of airborne molecular contaminants (AMC) is becoming a design requirement for all semiconductor manufacturing facilities. Chemical filtration in many forms is being employed in makeup air handling units, recirculation air handlers, minienvironments, fan filter units, and process tools. Suppliers of chemical filtration systems are being asked how best to determine if their systems are working and, if so, whether they are meeting design requirements.
Just as there are many ways to apply chemical filtration for the control of AMC, there are many different methods being used to measure AMC and to evaluate filter system performance. Employed in either real-time or passive form, reactivity monitoring has been used in a number of fabs for several years as a way to gauge AMC levels and to evaluate the effectiveness of AMC control strategies. Whether controlling AMC directly or indirectly, reactivity monitoring can provide an overall indication of ambient air quality as well as AMC levels within the controlled spaces.
This paper will focus on the use of reactivity monitoring as an air monitoring technique. Results of reactivity monitoring from semiconductor manufacturing facilities will be presented, illustrating both the validity of this air monitoring technique in general as well as its ability to gauge the effectiveness of chemical filtration when applied to the control of AMC.
Rectangular Control of Multi-Shaker Systems: Theory and Practical Results
Authors: Underwood Marcos , Keller Tony 
Published: April 2015

Most current multi-shaker, Multiple Input Multiple Output (MIMO), tests are performed on the basis of a "square" arrangement, in which the number of control accelerometers equals the number of controlled exciters. However, in some cases more control accelerometers than exciters may be desirable. This arrangement is referred to as "rectangular" control. Recent advances in digital control of multi-shaker and multi-axes systems have made rectangular control an achievable, if not a simple, reality.
This paper examines the theory behind this approach and also gives some practical results. Some unexpected benefits resulting from this new control approach are included.
Accelerated Testing for Demonstration of Product Lifetime Reliability
Authors: Krasich Milena 
Published: April 2015

This test is designed with the assumption that product reliability is a combination of its individual reliabilities under various operational and environmental stresses and of the undetermined interaction among these stresses. A well-designed reliability test accounts for all cumulative operational and environmental exposures to the stresses that the product will encounter in field use. To determine the level and duration of each of the individual stresses to be applied in the test, it is assumed that the stresses are independent, and a separate factor is added to make up for any unknown stress interactions. The synergism or the test sequence is not disregarded, as it might be the factor contributing to lower demonstrated reliability. The individual stresses are accelerated to allow for reasonable and cost-effective test duration. This test design cannot be accomplished without detailed knowledge of the product's usage profile, sequence of operation, and expected use environments.
The choice of test data analysis technique will depend on whether there were any test failures and on the type of failures. Where failures occur, acceleration factors are applied to determine the corresponding times to failure in field use. The test may be conducted as a reliability growth or a fixed duration test by applying the appropriate analytical techniques. The reliability growth technique may be preferred, as it normally yields tests of shorter duration.
Accelerated reliability testing provides realistic lifetime reliability demonstration or validation and, if performed early enough, allows for design changes to improve product reliability.
In designing any accelerated life test, caution should be exercised to avoid exceeding the environmental rating of the tested product, as high test acceleration can also induce failures that would normally not be expected to occur in the field life of the product. Also, acceleration factors must be carefully determined, preferably through accelerated testing to the failure mode of interest. Acceleration factors (their constants) may be different for different components of the tested products, thus care must be taken in their selection.
Application of a Real-time Process Simulator to PLC Programming for a Satellite Thermal Vacuum Chamber
Authors: Shin Younggy , Choi Seok-Weon , Moon Guee-Won , Seo Hee-Jun , Lee Sang-Hoon , Cho Hyokjin 
Published: April 2015

A thermal vacuum chamber is used to simulate thermal environments of a test satellite in orbits where daily temperature variations range from 80 K to above 400 K. The test facility is complex and consists of expensive parts. Modification of control software is discouraged as the modification may cause unexpected system failure. This paper describes a study that develops a real-time dynamics model of the thermal vacuum chamber that can be used to create control algorithms and simulate electrical inputs and outputs for interface with a programmable logic controller (PLC). The dynamics model is represented by simulation software and exported to a target PC in the Microsoft® Disk Operating System (DOS) mode to exploit the real-time kernel of the DOS software. The model is executed in real-time and communicates with a microprocessor-based input/output (I/O) board via a serial port to emulate electrical inputs and outputs.
The target process to model is the gaseous nitrogen (GN2) mode in which GN2 circulates in a closed loop through thermal shrouds encompassing a test object. A blower boosts the GN2. Injected liquid nitrogen (LN2) and an electric heater control the set temperature of the GN2. The realized simulator dynamics are quite similar to those of the thermal vacuum chamber and serve as an appropriate system to verify the control performance of a programmed PLC.
Accelerated Reliability Growth Testing and Data Analysis Method
Authors: Krasich Milena 
Published: April 2015

Traditionally, a reliability growth test was performed at the levels of various operational and environmental stresses, often at a level equal to that expected in use. Other than formal failure modes and effects analysis, reliability growth tests were often the only practical means for identification and mitigation of failure modes of a newly designed product.
With the present high reliability requirements and long product useful life, the length of reliability growth tests may become cost and schedule prohibitive; therefore, accelerated testing is taking the place of prior testing at the use levels. This practice, however, does not address the dilemma of possibly unrealistically skewed test results highly dependent on the sequence of individually applied stresses as, unfortunately, it is often difficult to impossible to apply all of the environmental and operational stresses simultaneously. An example of this problem would be a case where the majority of failure modes in a product are a result of or are related to a specific stress, and this test was performed early in the program. These early failures would then produce a high growth rate and an incorrect estimate of the product achieved reliability if the analysis were done by standard analytical models. The test data also may be skewed in the opposite way, producing little or no reliability growth. This concern has been addressed as a serious caution in Edition 2 of the International Electrotechnical Commission (IEC) 61014 Programmes for reliability growth.
This study shows how data analysis applied to an accelerated life test based on reliability growth methodology may produce a viable solution to the calculation problems. The stresses applied in this test are an accelerated application of most of the stresses expected to take place during product use. Each of the tests represents a lifetime exposure to an individual stress. If those stresses are applied individually and in sequence, they are considered to be equivalent to being applied in parallel with one another, as the duration of each stress is calculated to represent life of the product.
Time to failure in each test is re-calculated to represent time to failure in real life. Failure occurrences are then sorted in their increasing order and analyzed using one of the reliability growth test analytical methods.
Rehabilitative treatment after unsuccessful teeth replantation: a case report
Authors: Kramer Paulo Floriani , Horst Sady , König Joice , Reston Eduardo Galia , Calvete Ernani 
Published: April 2015

A nine-year-old boy suffered a severe facial trauma in a bicycle crash, which resulted in the avulsion and subluxation of upper central incisors.Teeth were repositioned and stabilized, attempting to achieve a successful replantation. Root resorption occurred, teeth were extracted, followed by orthodontic treatment, and esthetic procedures, modifying laterals and canines.
This article reports an attempt and failure of replantation, providing alternatives for achieving patient's satisfaction, applying a variety of techniques and areas of dental profession.
Clinical evaluation of a patient with single maxillary central incisor
Authors: Kamasaki Youko , Fukumoto Satoshi , Kubota Kazumi , Goto George 
Published: April 2015

Hypodontia in permanent dentition is the most common developmental anomaly and frequently found in the second premolar and maxillary lateral incisor. In the primary dentition, however, hypodontia appears to be less frequent, with the exception of cases such as ectodermal dysplasia and cleft lip and palate.We report a child with one primary maxillary central incisor at midline. The presence of a single permanent maxillary central incisor was also confirmed by radiological examination. Other intraoral abnormalities were detected including absence of upper labial frenulum and abnormal palatal structure, but no other facial or brain anomalies.
Although the condition is exceedingly rare, a thorough examination for more serious anomalies should be conducted since it is suggested to be the mildest feature of holoprosencephaly.
Dentigerous cyst associated with an upper permanent central incisor: case report and literature review
Authors: Naclério Homem Maria da Graça , Simões Wilma Alexandre , Zindel Deboni Maria Cristina , Chilvarquer Israel , Traina Andreia Aparecida 
Published: April 2015

Traumas to deciduous teeth may have severe consequences. This article addresses a dentigerous cyst case report associated with an upper permanent incisor, unusual site of occurrence, which was impacted and dislodged from its natural site of eruption after trauma at the deciduous predecessor.The main aspects of etiopathology and its clinical characteristics are also discussed, with especial focus on the radiographic features of the diagnosis in order to allow for an accurate surgical planning.
Seckel syndrome: report of a case
Authors: Seymen Figen , Tuna Bahar , Kayserili Hulya 
Published: April 2015

An interesting case of a seven years old boy with a combination of clinical, genetic, radiological, pathologic and dental findings is presented in view of Seckel syndrome literature. General appearance of the patient was characterized by small forehead, posteriorly slanted ears, slightly beaked nose, midfacial hypoplasia very stunted stature with microcephaly. He had borderline mental retardation with normal motor development.
Class II dentoskeletal pattern with mild overjet and open bite, congenitally missing permanent teeth, microdontia, enamel hypoplasia, taurodontism and dentinal dysplasia was observed according to the clinical and radiographic examination. In conclusion, Seckel syndrome is not encountered routinely in dental clinics, this case illustrates the importance of dental care in such a rare condition.
The application of fiber core posts in restoring badly destroyed primary incisors
Authors: Sharaf Aly 
Published: April 2015

Early childhood caries (ECC) represents a challenge to pediatric dentists especially, when teeth are badly destroyed. ECC involves the upper anterior teeth early in life and by the time the dentist sees the child, most of the coronal structure is lost. Dentally, this is a very devastating situation for both the dentist and parents, as in many cases, extraction of these teeth is the only option.
With the introduction of new adhesive systems and restorative materials, a new approach for treating these teeth is explained and documented by clinical cases, where fiber core posts are introduced into the root canals of primary incisors for a distance of 2 to 3 mm. It is retained in place by flowable composite, then the coronal part is reconstructed by a strip crown to restore the crown form. After a follow up period of one year, only 2 teeth out of 30 had to be extracted. The failure was attributed to failure in pulpal therapy rather than failure in the restorations, which were totally intact. A laboratory testing of the fracture load resistance of the restored teeth proved that this technique significantly improved the fracture load resistance of composite celluloid crowns, making it a valuable procedure to consider when the coronal tooth structure is not enough to support and retain a composite celluloid strip crown.
Impact of nasal airway obstruction on dentofacial development and sleep disturbances in children: preliminary notes
Authors: Defabjanis Patrizia 
Published: April 2015

Respiratory disorders in the upper respiratory tract during sleep are most often part of a continuous pathological process of long standing. Schematically, three clinical syndromes with increasing severity are described: breathing with the mouth open, snoring and sleep apneal hypopnea syndrome. Obstructive sleep apnea syndrome (OSAS) is a subtle, but severe sleep disorder of early childhood. It is often difficult to detect and may have long-term consequences, including failure to thrive, behavioral disturbances, developmental delay, and cor pulmonale.1 These conditions always include a functional maxillofacial perturbation, which may be associated with a constitutional or acquired morphological disorder.
Pediatric dentists must be aware of the problems connected with mouth breathing and OSAS (obstructive sleep apnea syndrome) in children as any delay in diagnosis and treatment may cause prolonged morbidity. They also have a role in the diagnosis and co-management of these patients because the signs and symptoms may be recognizable in the dental practice.
Besides the medical approach itself, the treatment sometimes is surgical, always orthopedic: the earlier it is initiated, the more effective, simple and unrestraining it is. The aim of this work is to focus attention on the early diagnosis and prevention of these pathologies. Diagnostic guidelines will be illustrated.
Post-traumatic TMJ internal derangement: impact on facial growth (findings in a pediatric age group)
Authors: Defabianis Patrizia 
Published: April 2015

Many clinical studies have shown how jaw injuries sustained during impact trauma to the face or mandible are the single most important cause of TMJ subsequent internal derangement. Proper function of the masticatory system is certainly the most influential variable in the TMJ remodelling; once a TMJ is internally deranged, adaptative or degenerative osteocartilagineous processes take place in the mandible, temporal bones and muscles.To evaluate relationships between consequences of posttraumatic TMJ internal derangement and disturbed facial skeleton growth in children, 25 patients (16 boys, 9 girls), 14 year of age or younger, were selected out of a group of 74 and analysed. They all had been treated by physiotherapy and had undergone combined clinical and radiographic examination for five years. Symptoms included, either individually or in various combination, pain, mechanical TMJ dysfunction and facial skeletal abnormalities, such as mandibular retrognathia and lower facial asymmetry manifested by chin deviation from the midline. Seventeen patients were found to have at least one abnormal and internally deranged TMJ on imaging studies; in twelve of them a mandibular asymmetry with chin deviation from the midline to the smaller or more degenerated TMJ was evident. Of the eight retrognathic patients, five were found to have bilateral TMJ derangement. In three patients both TMJ(s) were normal with normal facial structure.These data suggest that TMJ derangement in children may potentially have an impact on facial growth and lead to the development of retrognathia, with or without asymmetry, in many cases.
Polyethylene ribbon fibers
Authors: Island Gema , White G.E. 
Published: April 2015

Dentistry has advanced to the point where it is undesirable for children to be partially edentulous or to have unattractive anterior teeth. With the introduction of new materials and adhesive systems the use of polyethylene fibers as post and core offer a new reconstructive alternative for severely destroyed primary anterior teeth. These fibers offer root and coronal retention, stability and esthetics, and it is done chair side. The present study compared two different types of fibers and analyzed the fracture resistance between the two of them. Two groups were formed. Group I used non pre-impregnated resin fibers (glasSpan) and group II used pre-impregnated resin fibers (Splint-it). Both types of fibers have been used as post and core in the restoration of primary teeth and clinical studies have been published. Our results indicated that the mean fracture resistance for group I was 71.346 and for group II 97.952 (p=0.004). During the observation of the fractured samples, adhesive failures were noted for group I at the junction between the fiber and its core to the interior wall of the root canal. In group II, the fibers were dislodged out of the canal and the core part of the canal remained intact. It can be concluded that pre-impregnated fibers offer a better fracture resistance when used as post in endodontically treated primary anterior teeth.
J Clin Pediatr Dent 29(2): 151-156, 2005
Maxillary incisor palatal erosion
Authors: Chadwick R.G. , Mitchell H.L. , Manton S.L. , Ward S. , Ogston S. , Brown R. 
Published: April 2015

The objectives of the study were to examine a relationship between tooth erosion affecting the palatal aspects of permanent maxillary central incisors with dietary, behavioral and medical variables. The methods included, 251 schoolchildren aged 11 to 13 years were recruited to participate. Each subject had dental impressions of the palatal aspects of both upper central incisors recorded at baseline, 9 and 18 months intervals. From these, electroconductive replicas were fabricated, mapped and compared using a surface matching technique. At the end of the study all participants underwent a structured interview that sought to assay the level of potential erosive dietary, behavioral and medical risk factors. Correlation analyses of the responses given in the final structured interview with the degrees of palatal tooth substance loss (both previous and measured) were under taken. The results showed: 1. The degree of previous erosion did not predict the level of measured ongoing erosion. 2. Brushing the teeth more frequently with fluoridated toothpaste correlated significantly with lower levels of ongoing erosion (P = 0.011). It was concluded that: 1. Evidence of previous palatal erosion did not predict future erosion. 2. The application of topical fluoride as a by-product of tooth brushing may provide an element of protection against palatal erosion. 3. In view of the lack of correlation between exposure to potential risk factors and the level of ongoing palatal tooth surface loss in this study, other factors (such as an individual’s susceptibility and salivary buffering power) may well be more important predictors. The clinical relevance included: Preventive advice to patients with dental erosion should not only include the use of topical fluoride, in the form of toothpaste, but recognize individual susceptibility to this condition.
J Clin Pediatr Dent 29(2): 157-164, 2004
Refining occlusion with muscle balance to enhance long-term orthodontic stability
Authors: Mahony Derek 
Published: April 2015

The primary objective of orthodontic treatment is the movement of teeth into a more ideal relationship, not only for aesthetic, but also for functional considerations. Another very important objective, often not given enough consideration, is the need to finish the case with the muscles of mastication in equilibrium. If muscle balance is not achieved, an endless procession of retainers is required for retention. In simple terms, if the occlusal forces in maximum intercuspation are unevenly distributed around the arch, tooth movement will most likely occur. Today, however, it is possible to simultaneously and precisely measure the relative force of each occlusal contact, the timing of the occlusal contacts and the specific muscle contraction levels. This technological breakthrough represents a paradigm shift in thinking and may improve orthodontic stability.
J Clin Pediatr Dent 29(2): 93-98, 2004