bluuebunny/crossref_metadata_2025_split huggingface dataset:
History of Field Observations on Volcanic Rocks of Western Mexico, Pre-Columbian to Recent
Authors: Swanson Eric 
Published: April 2015

By the time the first detailed reports on western Mexico's volcanic rocks had begun to appear in the 1970s, most of the earlier observations on these rocks and most knowledge of those who made these observations were all but forgotten. A review of previous field observations in this region shows, however, a long history of geologic discovery reflecting or even preceding developments elsewhere.Ethnological studies suggest that the Pre-Columbian inhabitants of the Sierra Madre Occidental (SMO) observed the characteristics of rock formations in their sierra homeland and understood something of the regional stratigraphic relationships. Late sixteenth and early seventeenth century explorers of the Spanish Colonial Period singled out volcanic rock known to them as piedra de malpaís for special recognition, and Padre Kino and his fellow explorers clearly recognized the volcanic origin of piedra de malpaís decades prior to similar observations in Europe. As the Spanish Colonial Period came to a close, Andrés Manuel del Río help organize a state-of-theart mining college in Mexico City where students were instructed in Werner's geognosy prior to their taking positions in Mexico's mining industry, most of it located in western Mexico's volcanic rocks.Although the first part of the tumultuous period between Mexico's revolutions of 1810 and 1910 saw few advances in geological knowledge, the reign of President Porfirio Díaz produced a geologic map of Mexico, the founding of the Instituto de Geología, and an ‘American invasion’ of geologists and mining engineers who locally gathered information on the nature of volcanic rocks of western Mexico. During the same period, Instituto geologist Ezequiel Ordóñez established the general stratigraphic sequence in the SMO, recognized the widespread occurrence of rhyolite there, and applied the petrographic microscope to the study of SMO volcanic rocks. The first identification of ignimbrites in the SMO came as a result of the World War II-era search for strategic minerals, and NASA's push to put a man on the Moon supported a series of student mapping projects producing the SMO's first geologic maps showing individual ignimbrite units and calderas.
Educational Service of the Tennessee Division of Geology, 1831-Present
Authors: Luther Edward 
Published: April 2015

The Tennessee Division of Geology has a close, long-term relationship with the educational establishment in Tennessee that has changed in nature over the years but remains strong. Gerard Troost, the first State Geologist, was a college professor, as was his successor, James M. Safford, and, more recently, L. C. Glenn. From 1909 to 1923 the affairs of the State Geological Survey were overseen by a Geological Commission that included, ex officio, the President of the University of Tennessee, the Chancellor of Vanderbilt University, and the Vice Chancellor of the University of the South; then, from 1923 to 1937, the Division of Geology was administratively part of the State Department of Education.
Since becoming part of the Conservation Department in 1937 the Division has served an educational function by publishing both scholarly and popular works on the geology of the state; by answering inquiries on every subject from paleontology to water-witching; by advising news media on geology-related stories; by giving talks to school, museum, and other groups; and by close cooperation with university geology departments on research projects. The Division has had a strong role in graduate education, particularly at the Master's level, by conducting field excursions for students, financing theses through student mapping projects, by loans of field equipment, and serving as informal thesis advisors. Long-term assistance to geology departments has also included part-time employment of professors as consultants, publication of studies by professors and students, and part-time teaching by Division staff members. Most of these forms of educational assistance have suffered in recent years, due to budget cuts and loss of staff positions.
"A Better Style of Art": The Illustrations of the Paleontology of New York
Authors: Blum Ann 
Published: April 2015

James Hall, like other authors and editors of 19th-century American state and federal surveys, learned first hand that publishing illustrations was time-consuming, frustrating and expensive. But illustrations were indispensible, providing the graphic communication of morphology that justified the author's taxonomic decisions. That essential information, however, passed through the hands of an illustrator and either an engraver or lithographer before it reached the scientific audience that would test and judge it. Artists and printers, therefore, needed close supervision; plates required careful proofing and sometimes cancellation. Hall, like his colleagues, vastly underestimated the time and expense that his project would entail.
The plates illustrating the Palaeontology reflected changes occurring in American science and printing. Over the decades spanned by the publication, picture printing techniques changed from craft to industry, and converted from engraving to lithography; so did the New York survey. Meanwhile, the scientific profession developed illustration conventions to which publications with professional intent increasingly conformed. These conventions combined standards of "accuracy" with issues of style to reflect both scientific activity and its social context. The early illustrations drawn by Mrs. Hall were no less "accurate" although clearly less polished than the collaborations between R.P. Whitfield and F.J. Swinton, or the later work of J.H. Emerton and E. Emmons, Jr. The artists and printers of the Palaeontology plates emulated and contributed to the emerging national style of zoological and paleontological illustration, and thus helped consolidate the "look" of American science.
A Look Back at the Permian Reefs of West Texas and New Mexico
Authors: Rigby J. , Millward Ann 
Published: April 2015

The Permian reef complexes of West Texas and New Mexico are among the classic carbonate sequences in the world and have significantly influenced geologic thinking for over half a century. Study of the reefs can be subdivided into 6 broad periods. The first period involved early exploration of the region, establishment of regional stratigraphic relationships and attempts at dating stratigraphic units. The Guadalupian Fauna typifies this early period. The second period, during the 1920-30's, was a time of early petroleum exploration in the region, following on discovery of the Kendrick Field in Winkler County, Texas, and resulted in attempts to explain the complicated subsurface stratigraphy. Development of a marginal reef model and research on facies relationships between the basin and shelf resulted in refinement of stratigraphic nomenclature.The third period, here termed the King period, was a time of more intense study of the outcrops and their subsurface extensions. It was a time when facies became more clearly differentiated and when the great diversity and abundance of fossils in the region became appreciated. This period ended when World War II curtailed research in the region. The fourth period began after the war, with heightened interest in reefs and paleoecology. It was a time when carbonate petrology and paleoecology rose as major fields of interest. It was also a time of mega-paleontology. Tens of tons of fossiliferous limestones were processed at the U.S. National Museum and the American Museum of Natural History and collections of literally millions of fossils were assembled. The earlier publication of Geology of the Southern Guadalupe Mountains, Texas and the later publication of The Permian Reef Complex of the Guadalupe Mountains Region, Texas and New Mexico characterize the period.The fifth period is marked by the return of industry investigators to study the reefs and associated rocks, perhaps spurred as much by Dunham's "Vadose pisolites in the Capitan reef" as by any single paper. The period was one of concern about origins of the distinctive pisolites of the complex, nature of the massive Capitan Limestone, diagenesis of carbonates and by concern for understanding the economically significant rocks of the backreef sequence. The sixth period, termed the Wisconsin phase, continued research along lines of the fifth period but was a time when faculty and students of the University of Wisconsin, and their associates, re-examined all facies of the Guadalupe Mountain reef complexes as a major effort, while industry became less broadly involved. Those efforts, and those now initiated by faculty and students of the University of Nebraska and Rice University, bring us essentially to date, but much still remains to be discovered and understood about the reef complexes.
Concepts of Natural Law and Time in the History of Geology
Authors: Guntau Martin 
Published: April 2015

Our contemporary conceptions of time in terms of geology have developed since the Renaissance. In addition to an adequate notion of the age of the earth, these ideas include different concepts of the nature of geological processes in history. Until the 19th century the different concepts of geological time were determined by views on cyclic processes and processes which have a direction, as well as sequences of events, with or without relations between their various phases. These different aspects of geological thought have finally been incorporated into evolutionary conceptions of geohistory.
Despite objective and epistemological problems, geological laws were formulated in the history of geology such as the law of superposition by Steno in 1669, the law of stratigraphy by Smith in 1799, and the law of development of the earth by Cotta in 1858. Laws of nature are interpreted as essential correlations of a general and necessary nature which exist independently of human cognition. Some fundamental geological processes have not been effective throughout the history of the earth. Presupposing that these processes were governed by natural laws as well, it is inferred that laws of nature exist over certain different periods of time. There are four possibilities of how long laws of nature, or combinations of them, can exist: (1) temporally unlimited existence, (2) existence from the beginning up to a certain point in time, (3) existence from a certain point in time up to the present time, (4) existence over a certain past period of time. Thus the science of geology shows that natural laws are of a historical nature, in that they do not exist eternally nor everywhere.
Trace Moisture in Ammonia: Gas Chromatography Using Calcium Carbide
Authors: Monroe Susan 
Published: April 2015

CaC2 is known to convert water to acetylene by the following reaction.
CaC2 + 2H2O → Ca(OH)2 + C2H2
The conversion rate of water to acetylene is reported to depend on reaction temperature, cell size, flow rate, particle size, and the type of gas studied. Data will be presented quantifying the amount of C2H2 evolved from the reaction of CaC2 with 3 to 10 ppm H2O in both helium and ammonia gas under a defined set of experimental conditions. A calibration curve is presented to illustrate linearity for acetylene detection by gas chromatography/discharge ionization detection (GC/DID) under these experimental conditions down to 15 ppb ±1.5 ppb. Taking into account the stoichiometry of the above reaction, the method could potentially have a sensitivity for water in the range of 30 to 50 ppb.
However, moisture challenges from 3 to 10 ppm in helium and ammonia were detected with an accuracy of only ±1 ppm. the precision of the measurement is a sum of the variance in the moisture input system plus variance in the reaction rate of water with calcium carbide. The reaction in NH3 requires a 2-hr residence time in the calcium carbide reaction cell for the water in the ammonia sample to fully react with the solid CaC2 at 40°C (104°F).
Reactivity Monitoring: An Alternative to Gas Monitoring in Semiconductor Cleanrooms?
Authors: Muller Chris 
Published: April 2015

One environmental parameter that is increasingly targeted for tighter control in semiconductor cleanrooms is airborne molecular contaminants (AMC). The biggest problem today is not whether specified levels of AMC can be achieved, but whether they can be accurately measured to ensure compliance with any standards or control criteria. A number of manufacturers are turning to environmental classification via reactivity (or corrosion) monitoring. This paper describes reactivity monitoring and examines its use for:
• Performing environmental assessments in cleanrooms as part of contamination control programs based on the presence (or absence) of corrosive AMC.
• Providing the short-term data required to manage and mitigate contaminant-specific episodes.
• Evaluating long-term air quality trends in a facility.
• Conducting research studies designed to determine relationships, if any, between contaminant levels and possible damaging effects.
Automated CO2 Composite Spray Cleaning System for HDD Rework Parts
Authors: Knoth G. , Jackson D. , Sorbo N. 
Published: April 2015

Many advanced assemblies require high-volume and cost-effective selective cleaning during various stages of assembly or rework operations. Due to component compatibility problems and drying challenges, partially assembled devices cannot be immersed in or sprayed with aqueous cleaners or solvents. Newer dry cleaning techniques such as carbon dioxide (CO2) aerosol spray cleaning processes (snow cleaning) have proven to be challenging to implement in automated high-volume manufacturing operations. Issues associated with conventional snow cleaning include high costs of operation, lack of process consistency, ineffective controls, and the requirements for a supply of high-purity liquid CO2.
Advanced CO2 composite spray [CO2(solid)-compressed dry air (CDA)(gas)] cleaning is an effective alternative to traditional spray and immersion cleaning processes and to conventional snow cleaning for selectively removing contaminants and films from partially assembled hard disk drive (HDD) components during the remanufacturing or rework process. CO2 consumption is reduced using a composite spray, while spray cleaning control and performance is improved. CO2 composite spray cleaning performance is dependent on the position, speed, and motions of the spray applicator, which are matched to comply with HDD factory output. Stored spray cleaning programs deliver precise cleaning seven days a week, 24 hours per day, with uptimes exceeding 99.9% over a 6-month period. Monitoring and controlling composite spray cleaning process parameters including spray pressure and composition, scanning speed, and pallet/part identification are done automatically. Operator interaction is limited to loading and unloading pallets for continuous system operation.
Laboratory Staff Evaluation Process
Authors: Weaver John 
Published: April 2015

Objectively evaluating laboratory staff is a very difficult task. Variations in supported equipment, student performance, and process sensitivity prevent the use of direct, objective criteria in employee performance measurement. These factors are multiplied in research facilities, where equipment uptime and process performance measurements are not easily determined. Supervisors, therefore, must apply more subjective techniques in staff evaluation, which often results in the perception of inequity. This paper presents a rigorous evaluation process that utilizes significant employee participation to address this issue of perceived inequity.
The process utilizes five areas of evaluation: Goals and Accountability; Job Performance; Individual Characteristics; Aspirations and Assistance; and Employee Feedback. These areas, applied through an employee self-evaluation followed by direct interaction between employee and supervisor, serve as discussion points as well as a means of performance documentation. While still primarily subjective in nature, the process significantly reduces any perception of unfairness and allows the employee to document issues for future reference. Introduced six years ago at the Birck Nanotechnology Center at Purdue University, the process has undergone numerous tweaks and enhancements leading to the version documented in this paper.
Behavior of pediatric dental patients throughout the course of restorative dental treatment in a private pediatric dental practice
Authors: Brill Warren 
Published: April 2015

The purpose of this study was to describe and quantify patient behavior patterns observed throughout restorative dentistry appointments in a private pediatric dental practice. Patient behavior throughout the course of the first restorative dental visit was recorded using the Sarnat Behavior Scale. Behavior of patients in age groups 0 to 5 (0 to 60 months), 5 to 8 (61 to 96 months) and 8 to 12 (97 to 144 months) was noted at the start of the visit, during the procedure and when the patient was dismissed. Socio-demographic variables such as sex and method of payment as an indicator of socio-economic status were also considered. In addition, it was also noted whether, the child was referred by a general dentist. The results showed that the percentage of patients having Sarnat scores of 3, 4 or 5 (S345), which is indicative of negative behavior, increased after the start of the visit and then decreased to a lower level when the patient was dismissed. This observation was the same for all age groups, although the percentage of patients exhibiting negative behavior during all phases of the restorative appointment decreased with increasing age.
In conclusion, pediatric dental patient behavior changes throughout the course of restorative dental treatment. There is an increase in negative behavior, while the teeth are being restored, which then decreases to levels below those observed at the start of the visit. This is related to age more than socioeconomic or other factors confirming that as the child ages, the incidence of negative behavior decreases, but the pattern of change during the course of the restorative visit is the same regardless of age.
Leakage reduction with a surface-penetrating sealant around stainless-steel orthodontic brackets bonded with a light cured composite resin
Authors: Chapra Anas , White George 
Published: April 2015

In this study a surface penetrating sealant was used around bonded stainless steel orthodontic brackets. The investigation attempted to identify the effect of surface penetrating sealants on the microleakage associated with orthodontic stainless steel brackets bonded with light cured composite resin.A total of 58 bovine teeth were used for this study, orthodontic brackets were bonded with light cured orthodontic resin. The following groups were assigned: (I) Finished but unsealed, (II) Finished and sealed, and (III,) Un-finished but unsealed The brackets were activated using orthodontic elastics, stained, sectioned, and evaluated under magnification. The following statistical analysis was done Mann-Whitney U test for two independent samples, then confirmed with a Kruskai-Wallis One-Way analysis of variance by ranks. The second and third groups were statistically better in respect of marginal integrity as compared to the first.
Class IV preparations for fractured anterior teeth restored with composite resin restorations
Authors: Eid Hani , White George 
Published: April 2015

Pediatric dentists play a major role in treating most of the anterior teeth fractures due to the fact that most patients who suffer such traumatic injuries are between the ages of seven and fourteen. Several techniques has been developed to restore the fractured incisors to the original shape and color, these include full-coverage of the traumatized tooth, or restoring the incisors with a resin. The purpose of this study is to find the ideal combination of tooth preparation and restorative material, namely, to determine if stair step chamfer preparations provide more retention in class IV restorations than the plain chamfer preparation technique when restored with a combination of a hybrid composite resin and a microfilled composite resin. This was done by comparing the shear strength values between the buccal stair-step chamfer preparation, and a modification on it (buccal and lingual stair-step chamfer preparation) and the plain chamfer preparation techniques in class IV restorations on anterior incisors using different composite resin materials. The Instron machine was used to test shear strength.One hundred and two bovine incisor teeth were freshly harvested from the slaughterhouse. The teeth were prepared and restored according to the following six groups; Plain Chamfer preparation with Tetric Ceram Composite, Plain Chamfer preparation with Renamel Composite, buccal stair-step chamfer preparation with Tetric Ceram composite, buccal stair-step chamfer preparation with Renamel composite, Buccal and lingual stair-step preparation with Tetric Ceram Composite, Buccal and lingual stair-step chamfer preparation with renamel composite. All samples were fractured using the Instron testing machine then the surface area were measured using Image-J software. Shear strength for every sample was calculated using the load numeric result from the Instron machine and the measured surface area.The Two-Factorial (AB) Analysis of Variance For Independent Samples showed that the buccal stair-step chamfer preparation showed significantly higher shear strength and fracture resistance than plain chamfer or the buccal and lingual stair-step chamfer preparation. The combination of Renamel Hybrid and Renamel Microfill composite materials showed better results than the Tetric Ceram composite when used with all three preparation techniques, but did not show a statistical significance.It was concluded that buccal stair-step preparation technique provided the ideal preparation technique with bonded composite resins in fractured anterior teeth. Only 7% of the entire sample size had an adhesion failure versus 93% that had cohesion failure. There was no significant difference in shear strength, between the restorative materials used, in conjunction with all the preparation techniques.
The effects of different application techniques and orifices on the amount of dentifrice
Authors: Aysegul Olmez , Dilek Tufekcioglu , Elgin Erdemli 
Published: April 2015

The purpose of this study was to evaluate three different methods (ST: Standart technique; PS: Pea-size; TT:Transverse technique) for dentifrice use in children between 5 to 7 years of age, as well as to compare the amount of dentifrice dispensed by using tubes with different orifices (moon or round shaped).
One hundered children who dispensed the dentifrice themselves were asked to apply the quantity of dentifrice they usually used (ST or TT) (Phase-I). In Phase-II, they were instructed to apply a pea-size amount (PS) and finally they were demonstrated to use the transverse technique (TT) in Phase-III. Statistical analysis was obtained by using Anova and t-test.
As a result, most of the children (82 patient) preferred to use ST rather than TT (18 patient). A decrease in the amount was obtained with both of the shaped orifices after the instruction of PS or demonstration of TT (p&lt; 0.05). It was observed that the amount of dentifrice dispensed decreased generally when a moon shaped orifice was used.
Oral soft tissue lesions in Greek children and adolescents
Authors: Sklavounou-Andrikopoulou Alexandra , Piperi Evangelia , Papanikolaou Vassilis , Karakoulakis Ion 
Published: April 2015

Pediatric oral pathology encompasses a wide clinical spectrum of local and systemic diseases. The purpose of this study was to evaluate the clinical characteristics of oral soft tissue lesions in Greek children and adolescents up to 18 years old. Data available through a 32 year old period revealed that among the 1040 cases analyzed, benign lesions, mainly cysts, inflammatory lesions and reactive hyperplasias, were the most common causes for seeking dental advice during childhood.
J Clin Pediatr Dent 29(2): 175-178, 2005.