Uniform simplification in a full neighborhood of a transition point

1974 ◽  
Vol 0 (149) ◽  
pp. 0-0 ◽  
Author(s):  
Yasutaka Sibuya
Keyword(s):  
Transition Point ◽  
Full Neighborhood

Polarized microbeam FT-IR analysis of single fibers

1996 ◽  
Vol 54 ◽  
pp. 206-207
Author(s):  
Liling Cho ◽  
David L. Wetzel
Keyword(s):  
Molecular Orientation ◽  
Transition Point ◽  
Polymer Fibers ◽  
Single Fiber ◽  
Wire Grid ◽  
Polyester Fibers ◽  
Ft Ir ◽  
Ir Analysis ◽  
The Relationship ◽  
Wire Grid Polarizer

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

scholarly journals An experimental study of the motion of ice past obstacles by the process of regelation

1976 ◽  
Vol 17 (75) ◽  
pp. 79-98 ◽  
Author(s):  
E. M. Morris
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Cross Sections ◽  
Transition Point ◽  
Water Layer ◽  
Single Object ◽  
Two Systems ◽  
Basal Sliding

AbstractThe results of regelation experiments, in which a single object is pulled through ice, cannot be applied directly to the problem of basal sliding in glaciers because the two systems have different geometries. When the force applied to a single object is small, impurities trapped in the regelation water-layer around the object inhibit the regelation process. At larger forces, above the Drake-Shreve transition point, impurities are shed in a trace behind the object. However, when ice moves over a series of obstacles a trace may exist above and below the transition point. The regelation velocity below the transition point is not reduced by the effect of trapped impurities. In an experiment in which brass cylingerrs of various cross-sections rotate in ice, the ratio between the expected regelation velocity, calculated using the basal-sliding theory of Nye, and the measured regelation velocity is 8±2, both above and below the transition point. The same ratio has been obtained by other workers with wires of similar thermal conductivity above the transition point. Measurements of température differences indicate that supercooling cannot be the main source of the unexpectedly low regelation velocities above the transition point.

Histotopography of haemorrhagic infiltration in the hanging cutaneous furrow: Where to look for haemorrhagic infiltration in hanging

2021 ◽  
pp. 002580242110232
Author(s):  
Guendalina Gentile ◽  
Stefano Tambuzzi ◽  
Salvatore Andreola ◽  
Riccardo Zoja
Keyword(s):  
Adipose Tissue ◽  
Microscopic Examination ◽  
Subcutaneous Adipose Tissue ◽  
Transition Point ◽  
Striated Muscle ◽  
Forensic Evidence ◽  
Hematoxylin And Eosin ◽  
Compression Area ◽  
Subcutaneous Adipose ◽  
Masson Trichrome Staining

The forensic evidence of hanging is based on the autopsy demonstration of the traces left by the noose or the ligature on the neck, as well as on the histological assessment of the hanging mark vitality. However, the specific topography of haemorrhagic infiltration in the context of the cervical damaged tissues involved in hanging is not known. We carried out an extensive microscopic examination to identify if haemorrhagic infiltration in hanging appeared in specific topographic locations that could have been considered as elective. From 102 victims of suicidal hanging, a skin fragment was sampled from the maximum compression area of the sulcus, including the skin portions immediately above and below it. The sampling was also extended to collect the subcutaneous adipose tissue and part of the striated muscle. A standard histological examination was performed on all the samples, and hematoxylin and Eosin, Weigert’s resorcin-fuchsin and Goldner’s Masson trichrome staining were performed. In all the cases assessed, the microscopic examination allowed the detection of haemorrhagic infiltration mainly in the deepest areas under the sulcus and especially in the deep dermis and at the transition point between the dermis and the subcutaneous adipose tissue, as well as in the context of its supporting connective tissue. Such areas could therefore be considered as regions in which the presence of haemorrhagic infiltration is more likely to be demonstrated. Accordingly, we recommend performing sampling similar to ours and focusing the search for haemorrhagic infiltration as suggested.

scholarly journals Closed loop obstruction and adhesive intestinal obstruction in perineal hernia

2020 ◽  
Vol 13 (12) ◽  
pp. e238112
Author(s):  
Ramprasad Rajebhosale ◽  
Mohammad Miah ◽  
Fraser Currie ◽  
Pradeep Thomas
Keyword(s):  
Small Bowel ◽  
Intestinal Obstruction ◽  
Rare Case ◽  
Transition Point ◽  
Closed Loop ◽  
Abdominoperineal Excision ◽  
Perineal Hernia ◽  
Bowel Gangrene ◽  
Adhesive Intestinal Obstruction

Perineal hernia with bowel gangrene is uncommon but known complication of laparoscopic extralevator abdominoperineal excision (ELAPE). We present a rare case of closed loop small bowel obstruction with bowel gangrene secondary to an incarcerated perineal hernia that developed 7 years after an ELAPE. Intraoperatively, we found a definitive transition point due to adhesions in pelvis and a closed loop obstruction of the distal small bowel at different site with gangrenous intestine. She was managed successfully surgically with adhesiolysis and fixation of defect with biological mesh. Prevalence of perineal hernias will rise in future because of the increasing cases of ELAPE, in which no repair of pelvic floor is performed. The need of follow-up of these operations and more reporting of such cases are important in increasing awareness of these complications. Patients should be made aware of such complications and should seek urgent medical care.

scholarly journals Strain-Rate and Grain‒Size Effects in Ice

1987 ◽  
Vol 33 (115) ◽  
pp. 274-280 ◽  
Author(s):  
David M. Cole
Keyword(s):  
Grain Size ◽  
Strain Rate ◽  
Transition Point ◽  
Boundary Migration ◽  
Peak Stress ◽  
Strain Rates ◽  
Thin Sections ◽  
Fine Grained ◽  
Lower Strain ◽  
Polycrystalline Ice

AbstractThis paper presents and discusses the results of constant deformation-rate tests on laboratory-prepared polycrystalline ice. Strain-rates ranged from 10−7to 10−1s−1, grain–size ranged from 1.5 to 5.8 mm, and the test temperature was −5°C.At strain-rates between 10−7and 10−3s−1, the stress-strain-rate relationship followed a power law with an exponent ofn= 4.3 calculated without regard to grain-size. However, a reversal in the grain-size effect was observed: below a transition point near 4 × 10−6s−1the peak stress increased with increasing grain-size, while above the transition point the peak stress decreased with increasing grain-size. This latter trend persisted to the highest strain-rates observed. At strain-rates above 10−3s−1the peak stress became independent of strain-rate.The unusual trends exhibited at the lower strain-rates are attributed to the influence of the grain-size on the balance of the operative deformation mechanisms. Dynamic recrystallization appears to intervene in the case of the finer-grained material and serves to lower the peak stress. At comparable strain-rates, however, the large-grained material still experiences internal micro-fracturing, and thin sections reveal extensive deformation in the grain-boundary regions that is quite unlike the appearance of the strain-induced boundary migration characteristic of the fine-grained material.

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