A Preliminary Study of the After‐Effect or Drift in Rubber Under Constant Load

Physics ◽  
1936 ◽  
Vol 7 (11) ◽  
pp. 421-425 ◽  
Author(s):  
Milton L. Braun
Keyword(s):  
Constant Load ◽  
After Effect ◽  
Preliminary Study

A Preliminary Study of the After-Effect or Drift in Rubber under Constant Load

1937 ◽  
Vol 10 (2) ◽  
pp. 224-230
Author(s):  
Milton L. Braun
Keyword(s):  
Specific Gravity ◽  
Power Law ◽  
Constant Load ◽  
Observation Time ◽  
Rubber Tube ◽  
Original Length ◽  
Specific Analysis ◽  
After Effect ◽  
Preliminary Study ◽  
Logarithmic Law

Abstract When a suitable weight is supported by suspension from a piece of rubber, as a stationer's band, the rubber may be stretched any amount up to several times its original length, but its new length is not constant; it increases with time. The increase in length with time is variously known as “after-effect, #x201D; “creep,” “drift,” “flow,” or “time-yield.” This phenomenon, which seems to have been very incompletely investigated, was probably first recognized by Dietzel in 1857. Kohlrausch in 1875 made an entensive study of both torsional and linear after-effect in metal, glass, and rubber. The load used by Kohlrausch on rubber were, however, exceedingly small, and the duration of drift was limited to one day. He came to the conclusion that drift in rubber followed a power law for the first sixty minutes. During the next decade Pulfrich slightly extended the work of Kohlrausch by experimentation on a red rubber tube, using elongations up to 150 per cent, with maximum observation time of 15 days. He concluded that the power law of Kohlrausch held for at least thirty minutes of drift. In 1903, Bouaase and Carrière observed the after-effect (in pure gum and sulfur cords of 4 mm. diameter and of specific gravity 0.984) under a great variety of experiments, and concluded that drift was to be expressed by an exponential or logarithmic law rather than by a power function. Both Phillips and Schwartz arrived at similar conclusions. More recently Ariano reported that the drift proceeded at a decreasing rate which finally assumed a constant value either finite or zero. Van Geel and Eymers found that for milled rubber the drift continued until the specimens broke, but that for rubber obtained by evaporation of latex all after-effect ceased within three minutes. Shacklock noted that creep took place for some hours and then reached a limit. Evidently more light needs to be cast on the probem of the drift effect in rubber. Two preliminary experiments on drift are herein considered; Part I on general trends, and Part II on more specific analysis of the effect as observed in one specimen.

The Ultrastructure of Metastatic Human Mammary Carcinoma After Prolonged Estrogen Therapy

1967 ◽  
Vol 25 ◽  
pp. 180-181
Author(s):  
John H.L. Watson ◽  
John L. Swedo ◽  
R.W. Talley
Keyword(s):  
Mammary Carcinoma ◽  
Osmium Tetroxide ◽  
Estrogen Therapy ◽  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Human Mammary Carcinoma ◽  
Surgical Biopsy ◽  
Lead Hydroxide ◽  
Preliminary Study ◽  
Hormonal Therapies

A preliminary study of human mammary carcinoma on the ultrastructural level is reported for a metastatic, subcutaneous nodule, obtained as a surgical biopsy. The patient's tumor had responded favorably to a series of hormonal therapies, including androgens, estrogens, progestins, and corticoids for recurring nodules over eight years. The pertinent nodule was removed from the region of the gluteal maximus, two weeks following stilbestrol therapy. It was about 1.5 cms in diameter, and was located within the dermis. Pieces from it were fixed immediately in cold fixatives: phosphate buffered osmium tetroxide, glutaraldehyde, and paraformaldehyde. Embedment in each case was in Vestopal W. Contrasting was done with combinations of uranyl acetate and lead hydroxide.

Fine structure of early degenerating myofibers in the tibialis anterior of young ‘MDX’ mouse

1988 ◽  
Vol 46 ◽  
pp. 322-323
Author(s):  
H.D. Geissinger ◽  
C.K. McDonald-Taylor
Keyword(s):  
Fine Structure ◽  
Muscle Regeneration ◽  
Tibialis Anterior ◽  
Genetic Defect ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Histopathological Changes ◽  
Electron Microscopic ◽  
Dystrophic Mouse ◽  
Preliminary Study

A new strain of mice, which had arisen by mutation from a dystrophic mouse colony was designated ‘mdx’, because the genetic defect, which manifests itself in brief periods of muscle destruction followed by episodes of muscle regeneration appears to be X-linked. Further studies of histopathological changes in muscle from ‘mdx’ mice at the light microscopic or electron microscopic levels have been published, but only one preliminary study has been on the tibialis anterior (TA) of ‘mdx’ mice less than four weeks old. Lesions in the ‘mdx’ mice vary between different muscles, and centronucleation of fibers in all muscles studied so far appears to be especially prominent in older mice. Lesions in young ‘mdx’ mice have not been studied extensively, and the results appear to be at variance with one another. The degenerative and regenerative aspects of the lesions in the TA of 23 to 26-day-old ‘mdx’ mice appear to vary quantitatively.

Ultrastructural observations of the aorta of calves implanted with a mechanical left ventricular assist device

1990 ◽  
Vol 48 (3) ◽  
pp. 834-835
Author(s):  
J P Cassella ◽  
V Salih ◽  
T R Graham
Keyword(s):  
Left Ventricular Assist Device ◽  
Ventricular Assist Device ◽  
Left Ventricular ◽  
Aortic Tissue ◽  
Assist Device ◽  
Ventricular Assist ◽  
Transmission Electron ◽  
Left Ventricular Assist ◽  
Preliminary Study

Left ventricular assist systems are being developed for eventual long term or permanent implantation as an alternative to heart transplantation in patients unsuitable for or denied the transplant option. Evaluation of the effects of these devices upon normal physiology is required. A preliminary study was conducted to evaluate the morphology of aortic tissue from calves implanted with a pneumatic Left Ventricular Assist device-LVAD. Two 3 month old heifer calves (calf 1 and calf 2) were electively explanted after 128 days and 47 days respectively. Descending thoracic aortic tissue from both animals was removed immediately post mortem and placed into karnovsky’s fixative. The tissue was subsequently processed for transmission electron microscopy (TEM). Some aortic tissue was fixed in neutral buffered formalin and processed for routine light microscopy.

A preliminary study on the potential of front face fluorescence spectroscopy for the discrimination of Moroccan virgin olive oils and the prediction of their quality

2021 ◽  
Author(s):  
Hicham Zaroual ◽  
El Mestafa El Hadrami ◽  
Romdhane Karoui
Keyword(s):  
Fluorescence Spectroscopy ◽  
Olive Oil ◽  
Virgin Olive Oil ◽  
Front Face ◽  
Virgin Olive Oils ◽  
Olive Oils ◽  
Preliminary Study

This study examines the feasibility of using front face fluorescence spectroscopy (FFFS) to authenticate 41 virgin olive oil (VOO) samples collected from 5 regions in Morocco during 2 consecutive crop seasons.

Dysarthria Profiles in Adults With Hereditary Ataxia

2019 ◽  
Vol 28 (2S) ◽  
pp. 915-924 ◽  
Author(s):  
Kristie A. Spencer ◽  
Mallory Dawson
Keyword(s):  
Rating Scales ◽  
Feedforward Control ◽  
Hereditary Ataxia ◽  
Severity Rating ◽  
Visual Analog Scales ◽  
Speech Characteristics ◽  
Ataxic Dysarthria ◽  
Preliminary Study

Purpose This preliminary study examined whether speech profiles exist for adults with hereditary ataxia based on 2 competing frameworks: a pattern of instability/inflexibility or a pattern of differential subsystem involvement. Method Four dysarthria experts rated the speech samples of 8 adults with dysarthria from hereditary ataxia using visual analog scales and presence/severity rating scales of speech characteristics. Speaking tasks included diadochokinetics, sustained phonation, and a monologue. Results Speech profiles aligned with the instability/inflexibility framework, with the pattern of instability being the most common. Speech profiles did not emerge for the majority of speakers using the differential subsystem framework. Conclusions The findings extend previous research on pure ataxic dysarthria and suggest a possible framework for understanding the speech heterogeneity associated with the ataxias. The predominance of the instability profile is consistent with the notion of impaired feedforward control in speakers with cerebellar disruption.

Executive Functions and Clinical and Academic Outcomes in Speech-Language Pathology Graduate Students

2020 ◽  
Vol 5 (5) ◽  
pp. 1221-1230
Author(s):  
Jane Roitsch ◽  
Kimberly A. Murphy ◽  
Anastasia M. Raymer
Keyword(s):  
Executive Function ◽  
Academic Outcomes ◽  
Graduate Program ◽  
Performance Outcomes ◽  
Future Research ◽  
Speech Language Pathology ◽  
Grade Point ◽  
Praxis Ii ◽  
Language Pathology ◽  
Preliminary Study

Purpose The purpose of this study was to investigate executive function measures as they relate to clinical and academic performance outcomes of graduate speech-language pathology students. Method An observational design incorporating correlations and stepwise multiple regressions was used to determine the strength of the relationships between clinical outcomes that occurred at various time points throughout the graduate program (clinical coursework grades throughout the program and case study paper scores at the end of the program), academic outcomes (graduate grade point average and Praxis II exam in speech-language pathology scores), and executive function (EF) scores (EF assessment scores, self-reported EF scores). Participants were 37 students (36 women, M age = 24.1) in a master's degree program in speech-language pathology at a southeastern U.S. university during the 2017–2018 academic year. Results Findings of this preliminary study indicated that a limited number of objective EF scores and self-reported EF scores were related to clinical and academic outcomes of graduate speech-language pathology students. Conclusion As results of this preliminary study suggest that EF tests may be related to clinical and academic outcomes, future research can move to study the potential role of EF measures in the graduate admissions process in clinical graduate programs such as speech-language pathology.

Hearing Screening Failure Among Students With Reading Impairment: Rate and Relation to Specific Reading Deficits

2020 ◽  
Vol 5 (5) ◽  
pp. 1212-1220
Author(s):  
Krystal L. Werfel ◽  
Laura Peek ◽  
Gabriella Reynolds ◽  
Sydney Bassard
Keyword(s):  
Hearing Screening ◽  
Literacy Assessment ◽  
Poor Reading ◽  
Reading Deficits ◽  
Reading Impairment ◽  
Underlying Factor ◽  
Specific Reading ◽  
Comprehension Skills ◽  
Preliminary Study ◽  
Reading Impairments

Background The purpose of this preliminary study was to explore one potential underlying factor that may contribute to poor reading outcomes: minimal hearing loss. Additionally, we compared decoding and comprehension deficits in students who passed or failed the hearing screening. Method Forty-three school-age students completed a hearing screening and a literacy assessment. Results Fifty-four percent of children with reading impairments failed the hearing screening, compared to only 21% of children with typical reading. Additionally, students who failed the hearing screening were more likely to exhibit decoding deficits; comprehension skills between the hearing screening groups did not differ. Conclusions Thus, children with reading impairments are more likely to fail hearing screenings than children with typical reading, and the deficits of those who fail hearing screenings appear to center on decoding rather than comprehension skills. Supplemental Material https://doi.org/10.23641/asha.12818252

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