Macroscopic Characteristics (macroscopic + characteristic)

Distribution by Scientific Domains

Selected Abstracts

Macroscopic Characteristics of Screwdriver Trauma

Alexandra M. Croft M.Sc.
Abstract:, The main objective of the study was to determine the type of macroscopic trauma created by a flat-tipped and a cross-tipped screwdriver. The second objective was to determine if the trauma inflicted by the two screwdrivers could be macroscopically differentiated. Three tests were conducted, each by a male volunteer. Each test consisted of 12 samples of fleshed pig ribs; six were stabbed with a flat-tipped screwdriver and the remaining six with a cross-tipped screwdriver (PhillipsŪ). Each sample received 15 stab wounds during the process. The stabbings were conducted at perpendicular and oblique angles, with fabric variables being utilized. Results illustrate two main categories of macroscopic skeletal trauma, fractures, and puncture wounds. By studying the macroscopic appearance in tandem with differing trauma frequencies, these two screwdriver types can be differentiated. [source]

Studies of light scattering from ethnic hair fibers

K. Keis
One of the most desirable hair attributes to consumers, irrespective of ethnic background, is hair shine. The light reflected from a fiber has two components, specular and diffuse. The specular fraction of reflected light from the front surface of the fiber is generally recognized as a contributor to high luster. The distinction between specular and diffuse reflection is, however, not always clearly defined. In this study an attempt has been made to differentiate between specular and diffuse reflectance by analyzing mathematically goniophotometric curves of light reflected from unaltered single hair fibers from European, African, and Asian ethnic groups. The effect of macroscopic characteristics of the hair fibers, such as fiber diameter, cross-sectional shape, and curvature on luster is demonstrated. Results indicate that broadening of the specular peak reduces luster values, and is related to these characteristics. Thus, specular peak broadening is one of the important features to take into account when evaluating luster. Therefore, a new method for luster evaluation from goniophotometric curves is proposed. Additionally, we present the general model for light scattering, showing how scattering by surface roughness of different origin and magnitudes, and the scattering and absorption processes by the hair's interior, affect the position of the specular reflectance peak and its broadening. [source]

Micro- and macroscopic characteristics to stage gonadal maturation of female Baltic cod

J. Tomkiewicz
A set of histological characteristics to judge ovarian development was established and used to elaborate morphological criteria of 10 maturity stages of Baltic cod Gadus morhua sampled throughout the annual cycle to represent different macroscopic maturity stages. The applied characteristics confirmed most stages of the macroscopic scale, but the separation of late immature and resting mature females remained imprecise. Atretic vitellogenic oocytes or encapsulated residual eggs identified the resting condition morphologically, but not all ovaries with visible signs of previous spawning showed such features. One ovarian stage that was previously classified as ,ripening' was changed to ,spawning', owing to the prevalence of hydrated eggs and empty follicles. Ovaries with malfunctions were defined by a separate stage. Macroscopic criteria were revised by comparing the gross anatomy of ovaries with their histology. Female length and gonado-somatic index supported stage definitions, but substantial variation in Fulton's condition factor and the hepato-somatic index rendered these of little use for this purpose. The time of sampling influenced staging accuracy. A female spawner probability function based on the proportion of ripening and ripe specimens in early spring seems to be the most appropriate method to estimate spawner biomass and reproductive potential. [source]

Tailoring Polymeric Hydrogels through Cyclodextrin Host,Guest Complexation

Xuhong Guo
Abstract A close correllation between molecular-level interactions and macroscopic characteristics of polymer networks exists. The characteristics of the polymeric hydrogels assembled from ,-cyclodextrin (,-CD) and adamantyl (AD) substituted poly(acrylate)s can be tailored through selective host,guest complexation between ,-CD and AD substituents and their tethers. Dominantly, steric effects and competitive intra- and intermolecular host,guest complexation are found to control poly(acrylate) isomeric inter-strand linkage in polymer network formation. This understanding of the factors involved in polymeric hydrogel formation points the way towards the construction of increasingly sophisticated biocompatible materials. [source]

A Thermo-Mechanical Formulation Describing the Frictional Behavior of Rubber

K. Hofstetter Dipl.-Ing.
In this paper mechanical and thermal phenomena during the sliding motion of a rubber block on a rough surface are investigated. The presented formulation describes the frictional behavior of rubber on a macroscopic scale. Thus, it is not necessary to consider the roughness of the surface explicitly. Only macroscopic characteristics of the involved solids are required for the contact formulation. For the purpose of parameter identification and model verification, experiments have been carried out. The results from numerical simulations by means of the Finite Element Method (FEM) agree well with the experimental results. [source]

Association of carotid artery atheromatous plaque types with cerebral perfusion

Dong Yan Gao
Abstract Background:, In an attempt to define the association of internal carotid artery atheromatous plaque morphology with potential cerebral ischaemia, we have investigated the relationship of different carotid plaque types with defects in cerebral perfusion. Methods:, In 130 patients requiring surgical correction of internal carotid artery stenoses greater than 70%, defects in cerebral perfusion due to both haemodynamic insufficiency and intracerebral vessel occlusion were identified using single photon emission computed tomography scans (SPECT). Carotid artery plaques in these patients were classified as homogeneous or heterogeneous based on preoperative Doppler Duplex Scanning and on the macroscopic characteristics of the plaques recorded by the surgeon during carotid endarterectomy, with sub-classification into potentially embolus-generating and non- embolus-generating plaques. In individual patients, plaque types were then correlated with the perfusion defects found in the SPECT scans. Results:, Of 130 patients, 112 (86%) had cerebral perfusion defects. In 56 asymptomatic patients in the study, 48 (85.7%) had perfusion defects as did 64 (86.5%) of 74 symptomatic patients. Cerebral infarcts were seen in 41 (31.5%). Occlusive infarcts (66%) were twice as frequent as haemodynamic insufficiency infarcts (34%). Eighteen patients with small cerebral infarcts on SPECT scanning gave no medical history of cerebral symptoms. Statistical analysis of the results revealed that there was no statistically identifiable association between carotid plaque type and the generation of cerebral symptoms or infarction. Conclusion:, This study found that internal carotid plaque morphology has no statistically significant association with perfusion defects, symptoms or cerebral infarction in patients with significant internal carotid artery stenosis. Also, it is suggested that haemodynamic cerebral infarction may be more common that previously believed (34% of infarcts identified in the study). Further, it is suggested that plaque morphology alone is not an indication for carotid endarterectomy. [source]