Determination of relevant “average” properties for tubular filler materials used in composites

2011 ◽  
Vol 31 (4) ◽  
Author(s):  
Patrick M. Piccione
Keyword(s):  
Carbon Nanotubes ◽  
Average Diameter ◽  
Weighting Factor ◽  
Filler Materials ◽  
Cross Sectional ◽  
The Third ◽  
Materials Used ◽  
Third Moment ◽  
Calculation Procedures

Abstract To obtain the best estimate of the average diameter and number of walls of tubular objects such as carbon nanotubes, which are used as filler materials in composites, both inner and outer diameters must be taken into consideration. The appropriate weighting factor is calculated from the cross-sectional circular shell area. In the case of cylindrical objects, the formulae simplify considerably and the average diameter and wall thickness are the third moment of their distribution function. Two examples illustrate the numerical effects of these calculation procedures.

SEL VƏ DAŞQIN AXINLARINDA DAĞ ÇAYLARI MƏCRASININ YUYULMA DƏRİNLİYİNİN TƏYİNİ

2021 ◽  
Vol 1 (1) ◽  
pp. 82-88
Author(s):  
F.Ş., Əhmədov ◽  
R.K., Quliyev ◽  
R.Ü Əbdüləzimov
Keyword(s):  
Average Velocity ◽  
Average Diameter ◽  
Average Depth ◽  
Mountain River ◽  
Mountain Rivers ◽  
Cross Sectional ◽  
Average Width ◽  
Caucasus Mountains ◽  
Flood Flow

Abstract. The article is dedicated to the determination of the wash depth of mountain rivers in floods and overflows. As well-known, hydrotechnical equipment is exposed to destructive damages of the floods and overflows. The undersurface of bridge basement and coast guards are washed away, the surface of drainage devices in water supply and dams (Düker) at river crossings are opened up. Therefore, the protection of the equipment against the destructive damage of the floods and overflows should be ensured. To this aim, first of all, the depth of the fortification of the equipment basement in riverbeds and the width through which the river can flow should be determined and the works of installing coast guards should be accordingly implemented. Since the flow regime of rivers due to floods in the course of mountain riverbeds dramatically changes, the width, depth, roughness and cross-sectional area of the riverbed also changes. To that reason, in the smallest case, calculation formulas includes the average width and wash depth of the riverbed in the course of the floods and overflows, average diameter of undersurface soils, the slope of the location of hydrotechnical structures, velocity due to the average diameter of the riverbed soils and so on. The article contains the analyses of theoretical and practical materials about the floods and overflows in mountain rivers. For the rivers flowing through the southern hills of Great Caucasus Mountains, the expressions for determining the riverbed parameters and hydrological parameters of rivers are used. According to the expressions, average width due to non-washing of the riverbed in floods in accordance with flood flow and slope of the studied part of the riverbed, the average depth of the riverbed crossing the flood, the average velocity of the flow and the wash depth in accordance with them are determined. basing on all these, the determining method of the wash depth of mountain riverbeds in floods have been worked out and determining the wash depth have been recorded. The studied methodology can be used in determining the riverbed parameters in floods and overflows. Keywords: Flood, riverbed deformation, mountain river, wash depth, average diameter of undersurface sediments, riverbed stability, flood velocity

scholarly journals The thermal and electrical conductivity of a single crystal of aluminium

1927 ◽  
Vol 115 (770) ◽  
pp. 236-241 ◽  
Keyword(s):  
Electrical Conductivity ◽  
Single Crystals ◽  
Test Specimen ◽  
Average Diameter ◽  
National Physical Laboratory ◽  
Present Communication ◽  
Uniform Size ◽  
The Third ◽  
Physical Laboratory

The recent work of Carpenter and Elam on the growth of single crystals of large dimensions has rendered possible the study of the physical constants of single crystals of the commoner metals, and the present communication describes the determination of the thermal and electrical conductivity of aluminium in the form of an isolated crystal. The form of the crystal investigated is shown in fig. 1. This crystal had been prepared at the National Physical Laboratory employing the technique described by Carpenter in “Nature,” p. 266, August 21, 1926, which briefly is as follows:— The test specimen is machined and subjected to three treatments, thermal, mechanical, and thermal. The first treatment is necessary to soften the metal completely and produce new equiaxed crystals of so far as possible uniform size, the average diameter being 1/150 inch. The second consists in straining these crystals to the required amount, and the third in heating the strained crystals to the requisite temperature, so that the potentiality of growth conferred by strain could be brought fully into operation.

Development of Carbon Nanotube Based Through-Silicon Vias

2010 ◽  
Vol 1 (2) ◽  
Author(s):  
Bruce C. Kim ◽  
Sukeshwar Kannan ◽  
Anurag Gupta ◽  
Falah Mohammed ◽  
Byoungchul Ahn
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
High Performance ◽  
Integrated Systems ◽  
High Resistivity ◽  
Filler Materials ◽  
Through Silicon Vias ◽  
Single Walled Carbon Nanotube ◽  
Materials Used ◽  
Silicon Vias

The design and development of reliable 3D integrated systems require high performance interconnects, which in turn are largely dependent on the choice of filler materials used in through-silicon vias (TSVs). Copper, tungsten, and poly-silicon have been explored as filler materials; however, issues such as thermal incompatibility, electromigration, and high resistivity are still a bottleneck. In this paper, we investigate single-walled carbon nanotube (CNT) bundles as a prospective filler material for TSVs and have provided an analysis of CNT based TSVs for package and chip interconnects. The interconnects are fundamental bottlenecks to achieving high performance and reliability. We have provided electrical modeling and performed simulations on TSVs with copper and carbon nanotubes. The results from the CNT based TSVs were greatly superior to those from the conventional vias with copper.

Monte Carlo Algorithms for Moments of Transition Arrays

1988 ◽  
Vol 102 ◽  
pp. 79-81
Author(s):  
A. Goldberg ◽  
S.D. Bloom
Keyword(s):  
Monte Carlo ◽  
State Vector ◽  
Basis Vector ◽  
Collective State ◽  
Dispersion Characteristics ◽  
Dipole Strength ◽  
The Third ◽  
Monte Carlo Algorithms ◽  
Third Moment ◽  
Very High

AbstractClosed expressions for the first, second, and (in some cases) the third moment of atomic transition arrays now exist. Recently a method has been developed for getting to very high moments (up to the 12th and beyond) in cases where a “collective” state-vector (i.e. a state-vector containing the entire electric dipole strength) can be created from each eigenstate in the parent configuration. Both of these approaches give exact results. Herein we describe astatistical(or Monte Carlo) approach which requires onlyonerepresentative state-vector |RV> for the entire parent manifold to get estimates of transition moments of high order. The representation is achieved through the random amplitudes associated with each basis vector making up |RV>. This also gives rise to the dispersion characterizing the method, which has been applied to a system (in the M shell) with≈250,000 lines where we have calculated up to the 5th moment. It turns out that the dispersion in the moments decreases with the size of the manifold, making its application to very big systems statistically advantageous. A discussion of the method and these dispersion characteristics will be presented.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

Investigations on skeletal growth zones via bone scans as base of determination of optimal time for surgery in mandibular asymmetry

2000 ◽  
Vol 39 (05) ◽  
pp. 121-126 ◽  
Author(s):  
R. Werz ◽  
P. Reuland
Keyword(s):  
Bone Growth ◽  
Region Of Interest ◽  
Tracer Uptake ◽  
Optimal Time ◽  
Mandibular Bone ◽  
The Third ◽  
Mandibular Asymmetry ◽  
Bone Scans ◽  
Epiphyseal Plates

Summary Aim of the study was to find out wether there is a common stop of growth of mandibular bone, so that no individual determination of the optimal time for surgery in patients with asymmetric mandibular bone growth is needed. As there are no epiphyseal plates in the mandibular bone, stop of growth cannot be determined on X-ray films. Methods: Bone scans of 731 patients [687 patients (324 male, 363 female) under 39 y for exact determination of end of growth and 44 (21 male, 23 female) patients over 40 y for evaluation of nongrowth dependant differences in tracer uptake] were reviewed for the study. All the patients were examined 3 hours after injection of 99mTc-DPD. Tracer uptake was measured by region of interest technique in different points of the mandibular bone and in several epiphyseal plates of extremities. Results: Tracer uptake in different epiphyseal plates of the extremities shows strong variation with age and good correlation with reported data of bone growth and closure of the epiphyseal plates. The relative maximum of bone activity is smaller in mandibular bone than in epiphyseal plates, which show well defined peaks, ending at 15-18 years in females and at 18-21 years in males. In contrast, mandibular bone shows no well defined end of growing but a gradually reduction of bone activity which remains higher than bone activity in epiphyseal plates over several years. Conclusion: No well defined end of growth of mandibular bone exists. The optimal age for surgery of asymmetric mandibular bone growth is not before the middle of the third decade of life, bone scans performed earlier for determination of bone growth can be omitted. Bone scans performed at the middle of the third decade of life help to optimize the time of surgical intervention.

THE FACTORS OF CAREER SELF-DETERMINATION OF STUDENTS OF HIGHER EDUCATION INSTITUTIONS

2019 ◽  
Vol 7 (1) ◽  
pp. 9-20
Author(s):  
Inna Yeung
Keyword(s):  
Higher Education ◽  
Higher Education Institutions ◽  
Well Being ◽  
Young Person ◽  
Self Determination ◽  
Full Time ◽  
Actual Problem ◽  
The Third ◽  
The Right

Choice of profession is a social phenomenon that every person has to face in life. Numerous studies convince us that not only the well-being of a person depends on the chosen work, but also his attitude to himself and life in general, therefore, the right and timely professional choice is very important. Research about factors of career self-determination of students of higher education institutions in Ukraine shows that self-determination is an important factor in the socialization of young person, and the factors that determine students' career choices become an actual problem of nowadays. The present study involved full-time and part-time students of Institute of Philology and Mass Communications of Open International University of Human Development "Ukraine" in order to examine the factors of career self-determination of students of higher education institutions (N=189). Diagnostic factors of career self-determination of students studying in the third and fourth year were carried out using the author's questionnaire. Processing of obtained data was carried out using the Excel 2010 program; factorial and comparative analysis were applied. Results of the study showed that initial stage of career self-determination falls down on the third and fourth studying year at the university, when an image of future career and career orientations begin to form. At the same time, the content of career self-determination in this period is contradictory and uncertain, therefore, the implementation of pedagogical support of this process among students is effective.

Profil Penyakit Malaria Di Rumah Sakit Islam Siti Rahmah Padang Tahun 2018

2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana ◽  
Salmi Salmi
Keyword(s):  
Observational Study ◽  
Frequency Distribution ◽  
Cross Section ◽  
Laboratory Tests ◽  
Age Group ◽  
Normal Range ◽  
Cross Sectional ◽  
West Sumatra ◽  
Severity Of The Disease

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.

Profil Penyakit Malaria di Rumah Sakit Islam Siti Rahmah Padang Tahun 2018

2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana Y ◽  
Salmi Salmi
Keyword(s):  
Observational Study ◽  
Frequency Distribution ◽  
Cross Section ◽  
Laboratory Tests ◽  
Age Group ◽  
Normal Range ◽  
Cross Sectional ◽  
West Sumatra ◽  
Severity Of The Disease

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

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