A Novel Method for the Measurement of Slight Wear

2013 ◽  
Vol 750-752 ◽  
pp. 1987-1991
Author(s):  
Jian Hua Yang ◽  
Xing Jian Ma ◽  
Lu Fei Rong ◽  
Bo Liu ◽  
Jia Yan Yu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Measurement Accuracy ◽  
Processing Technology ◽  
Wear Testing ◽  
Cross Sectional ◽  
Speed Up ◽  
Novel Method ◽  
Pretreatment Conditions ◽  
Weighing Method

The characterization of surface wear resistance of materials usually relies on the measurement of slight wear. There are two obvious shortcomings for weighing method. In order to improve the measurement accuracy, a more intuitive and reliable method for quantitative measurement of slight wear, interference microscope method, has be given. Higher accuracy (the order of micrometer) can be achieved using the interferometry for the measurement of slight wear. The results show that the masking processing technology can ensure that all samples for wear testing and other analysis are obtained under the same pretreatment conditions and vacuum processing conditions, speed up the commercialization of processing technology, and comparing the cross-sectional areas of wear scars is a correct way to characterize the wear resistance of different zones.

scholarly journals First Study of the Prevalence and Characterization of Brachial Plexus Injuries in Guatemala

2021 ◽  
Vol 16 (01) ◽  
pp. e46-e50
Author(s):  
Carmen Joanna González Lemus ◽  
Fernando Xavier Romero Prieto
Keyword(s):  
Brachial Plexus ◽  
Brachial Plexus Injury ◽  
Main Mode ◽  
Cross Sectional ◽  
Speed Up ◽  
Male Patients ◽  
Mode Of Transportation ◽  
Surgery Department

Abstract Objective This study aimed to estimate the prevalence of brachial plexus injuries and to characterize clinically and epidemiologically patients with brachial plexus injury. Materials and Methods In this cross-sectional descriptive study, 2,923 medical records of patients aged 1 to 64 years who presented at outpatient peripheral nerve unit of the Orthopedic Surgery Department of Hospital Roosevelt, Guatemala, from January 2017 to December 2017, were prospectively analyzed to identify the prevalence and factors associated with brachial plexus injuries. Results The prevalence rate of brachial plexus injuries in patients was 5.74%. This injury is more common in men (90.5%) aged 24 to 64 years. Brachial plexus injuries occurred secondary to motorcycle accident in 72% of the cases, with the majority affecting the dominant upper extremity. In addition, 64.28% of the patients took 1 to 6 months to seek consultation, whereas only 16.07% requested medical assistance <1 month from the onset of symptoms, and this result was associated with early diagnosis and adequate recovery during follow-up. Furthermore, 66.67% presented upper brachial plexus injury with no associated fractures or vascular injury, manifesting distress while performing daily activities that required hand, arm, and elbow movements. Conclusion The risk of suffering BPIs in Guatemala increases in economically active male patients that use motorcycles as main mode of transportation. Patients should consult immediately after injury onset to optimize management results. For this reason, hospitals must develop specialized clinical guidelines to speed up the identification and treatment of BPI injuries.

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

TEM characterization of silicon epitaxial layer grown on Si-TaS2, eutectic composites

1991 ◽  
Vol 49 ◽  
pp. 802-803
Author(s):  
C.M. Sung ◽  
M. Levinson ◽  
M. Tabasky ◽  
K. Ostreicher ◽  
B.M. Ditchek
Keyword(s):  
Substrate Surface ◽  
Bulk Sample ◽  
Surface Cleaning ◽  
Native Oxide ◽  
Czochralski Growth ◽  
Ion Milling ◽  
Cross Sectional ◽  
Cleaning Methods ◽  
Field Emission Cathodes

Directionally solidified Si/TaSi2 eutectic composites for the development of electronic devices (e.g. photodiodes and field-emission cathodes) were made using a Czochralski growth technique. High quality epitaxial growth of silicon on the eutectic composite substrates requires a clean silicon substrate surface prior to the growth process. Hence a preepitaxial surface cleaning step is highly desirable. The purpose of this paper is to investigate the effect of surface cleaning methods on the epilayer/substrate interface and the characterization of silicon epilayers grown on Si/TaSi2 substrates by TEM.Wafers were cut normal to the <111> growth axis of the silicon matrix from an approximately 1 cm diameter Si/TaSi2 composite boule. Four pre-treatments were employed to remove native oxide and other contaminants: 1) No treatment, 2) HF only; 3) HC1 only; and 4) both HF and HCl. The cross-sectional specimens for TEM study were prepared by cutting the bulk sample into sheets perpendicular to the TaSi2 fiber axes. The material was then prepared in the usual manner to produce samples having a thickness of 10μm. The final step was ion milling in Ar+ until breakthrough occurred. The TEM samples were then analyzed at 120 keV using the Philips EM400T.

Characterization of Rh/Si multilayer structure by HREM and HAADF

1992 ◽  
Vol 50 (1) ◽  
pp. 122-123
Author(s):  
Y. Cheng ◽  
J. Liu ◽  
M.B. Stearns ◽  
D.G. Steams
Keyword(s):  
Normal Incidence ◽  
High Resolution Electron Microscopy ◽  
X Rays ◽  
Beam Direction ◽  
Cross Sectional ◽  
Optical Elements ◽  
Resolution Electron ◽  
Point To Point ◽  
Better Than

The Rh/Si multilayer (ML) thin films are promising optical elements for soft x-rays since they have a calculated normal incidence reflectivity of ∼60% at a x-ray wavelength of ∼13 nm. However, a reflectivity of only 28% has been attained to date for ML fabricated by dc magnetron sputtering. In order to determine the cause of this degraded reflectivity the microstructure of this ML was examined on cross-sectional specimens with two high-resolution electron microscopy (HREM and HAADF) techniques.Cross-sectional specimens were made from an as-prepared ML sample and from the same ML annealed at 298 °C for 1 and 100 hours. The specimens were imaged using a JEM-4000EX TEM operating at 400 kV with a point-to-point resolution of better than 0.17 nm. The specimens were viewed along Si [110] projection of the substrate, with the (001) Si surface plane parallel to the beam direction.

Comparison of Ion-Milling Techniques For Cross-Sectional TEM of Semiconductors

1985 ◽  
Vol 43 ◽  
pp. 166-167
Author(s):  
Julia T. Luck ◽  
C. W. Boggs ◽  
S. J. Pennycook
Keyword(s):  
Analytical Techniques ◽  
Sample Surface ◽  
Ion Milling ◽  
Cross Sectional ◽  
Reliable Technique ◽  
Near Surface ◽  
Transmission Electron ◽  
Thin Region ◽  
Transient Thermal

The use of cross-sectional Transmission Electron Microscopy (TEM) has become invaluable for the characterization of the near-surface regions of semiconductors following ion-implantation and/or transient thermal processing. A fast and reliable technique is required which produces a large thin region while preserving the original sample surface. New analytical techniques, particularly the direct imaging of dopant distributions, also require good thickness uniformity. Two methods of ion milling are commonly used, and are compared below. The older method involves milling with a single gun from each side in turn, whereas a newer method uses two guns to mill from both sides simultaneously.

High-resolution transmission electron microscopic study of highly oxygen doped silicon layer

1989 ◽  
Vol 47 ◽  
pp. 692-693
Author(s):  
H. Takaoka ◽  
M. Tomita ◽  
T. Hayashi
Keyword(s):  
High Resolution ◽  
Oxygen Concentration ◽  
Silicon Layer ◽  
Detailed Structure ◽  
Electron Microscopic ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Doped Silicon ◽  
Argon Ion

High resolution transmission electron microscopy (HRTEM) is the effective technique for characterization of detailed structure of semiconductor materials. Oxygen is one of the important impurities in semiconductors. Detailed structure of highly oxygen doped silicon has not clearly investigated yet. This report describes detailed structure of highly oxygen doped silicon observed by HRTEM. Both samples prepared by Molecular beam epitaxy (MBE) and ion implantation were observed to investigate effects of oxygen concentration and doping methods to the crystal structure.The observed oxygen doped samples were prepared by MBE method in oxygen environment on (111) substrates. Oxygen concentration was about 1021 atoms/cm3. Another sample was silicon of (100) orientation implanted with oxygen ions at an energy of 180 keV. Oxygen concentration of this sample was about 1020 atoms/cm3 Cross-sectional specimens of (011) orientation were prepared by argon ion thinning and were observed by TEM at an accelerating voltage of 400 kV.

TEM sample preparation of wear-tested room-temperature pulsed-laser-deposited thin films of MoS2 by ultramicrotomy

1993 ◽  
Vol 51 ◽  
pp. 1118-1119
Author(s):  
Pamela F. Lloyd ◽  
Scott D. Walck
Keyword(s):  
Thin Films ◽  
Sample Preparation ◽  
Room Temperature ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Ultra High Vacuum ◽  
Wear Testing ◽  
Preparation Technique ◽  
Cross Sectional ◽  
Aerospace Applications

Pulsed laser deposition (PLD) is a novel technique for the deposition of tribological thin films. MoS2 is the archetypical solid lubricant material for aerospace applications. It provides a low coefficient of friction from cryogenic temperatures to about 350°C and can be used in ultra high vacuum environments. The TEM is ideally suited for studying the microstructural and tribo-chemical changes that occur during wear. The normal cross sectional TEM sample preparation method does not work well because the material’s lubricity causes the sandwich to separate. Walck et al. deposited MoS2 through a mesh mask which gave suitable results for as-deposited films, but the discontinuous nature of the film is unsuitable for wear-testing. To investigate wear-tested, room temperature (RT) PLD MoS2 films, the sample preparation technique of Heuer and Howitt was adapted.Two 300 run thick films were deposited on single crystal NaCl substrates. One was wear-tested on a ball-on-disk tribometer using a 30 gm load at 150 rpm for one minute, and subsequently coated with a heavy layer of evaporated gold.

Genomic, Metagenomic and Transcriptomic Characterization of the Clinical Forms of COVID-19: A Comparative Cross-Sectional Study

2020 ◽  
Author(s):  
Christophe Rodriguez ◽  
Nicolas de Prost ◽  
Slim Fourati ◽  
Claudie Lamoureux ◽  
Guillaume Gricourt ◽  
...  
Keyword(s):  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Clinical Forms

Significados de Morte: o Discurso do Sujeito Coletivo da Enfermagem / Meaning of Death: the collective subject speech of the nursing staff

1970 ◽  
Vol 6 (1) ◽  
pp. 52-58
Author(s):  
Fellipe Afonso de Azevedo ◽  
Noé D’jalma Araújo ◽  
Néliton Célio de Novais ◽  
José Vítor da Silva ◽  
Renato Augusto Passos
Keyword(s):  
Nursing Staff ◽  
Hospital Setting ◽  
Field Research ◽  
Structured Interview ◽  
Minas Gerais ◽  
Structured Interviews ◽  
Cross Sectional ◽  
Emergency Units ◽  
Methodological Guidelines

RESUMOObjetivo: o presente trabalho teve como objetivo identificar os significados de morte emergentes das equipes de enfermagem que atuam nas unidades de Pronto Socorro e Unidade de Terapia Intensiva (UTI) em uma entidade de médio porte situada no Sul de Minas Gerais. Materiais e métodos: estudo de abordagem qualitativa, do tipo descritivo, de campo e transversal. A amostra estudada foi composta de oito enfermeiros, 22 técnicos e quatro auxiliares de enfermagem, totalizando 34 profissionais, sendo utilizado o instrumento de caracterização pessoal e profissional da equipe de enfermagem e o roteiro de entrevista semiestruturada. A amostragem foi proposital. A coleta de dados foi realizada através de entrevista semiestruturada, gravada e transcrita. As diretrizes metodológicas do Discurso do Sujeito Coletivo foram utilizadas para a seleção das ideias centrais e expressões-chave correspondentes, a partir das quais foram extraídos os discursos dos sujeitos, no cenário da instituição hospitalar. Resultados e Discussão: ao analisar o tema “significados de morte”, obtiveram-se as seguintes ideias centrais: “passagem”, “diversos significados”, “fim da vida” e “fim e começo de outra vida”. Conclusão: As concepções acerca do tema morte para os profissionais participantes deste trabalho reforça a necessidade de estudos sobre o tema durante a formação acadêmica. Certos de que irão vivenciar este tipo de situação no dia-a-dia profissional, é preciso prepará-los psicologicamente para isso.Palavras-chave: Morte, Equipe de enfermagem, Assistência ao paciente.ABSTRACTObjective: This study aimed to identify the meanings of emerging death of the nursing staff working in the Emergency Units and Intensive Care Unit (ICU) in a medium-sized entity located in southern Minas Gerais. Materials and methods: A cross-sectional qualitative field research. The sample was composed of 8 nurses, 22 technicians and 4 nursing assistants, totaling 34 professionals. It was used a tool of personal and professional characterization of the nursing team and a semi-structured interview. Sampling was intentional. Data collection was conducted through semi-structured interviews, that were recorded and transcribed. The methodological guidelines of the Collective Subject Speech were used for the selection of the central ideas and corresponding key expressions, from which the speeches of the subjects were taken, in the hospital setting. Results and discussion: to examine the topic "death meanings" yielded the following core ideas: "pass", "different meanings", "end of life" and "end and beginning of another life." Conclusion: The conceptions about the death theme for the professional participants of this study reinforces the need for studies on the subject during their academic training. It is certain that they will experience this type of situation on their daily professional routine, therefore there is a need to prepare them psychologically for this.Keywords: Death, Nursing staff, Patient care.

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