251 research outputs found
Analysis Of The Influence Of Agricultural And Non-Agricultural Sectors Performance On The Nigerian Economy (1986-2004)
This paper examines the influence of agricultural and non-agricultural economies on Nigeria\'s total economy. Time series data such as Nigeria\'s total GDP, Agricultural GDP and non-agricultural GDP were obtained. A double logarithm and exponential functions were used to estimate the elasticity and growth rate of each sector and the economy as a whole. The results revealed that a % change in Agricultural and Non-agricultural sectors caused the Nigerian economy to change by 0.24% and 0.746% respectively. The agricultural, non-agricultural sector and the entire economy grew at the rate of 0.04%, 0.124% and 0.102% respectively during the study period. Keywords: Agricultural sector, Non-agricultural sector, Nigerian economy. Global Journal of Agricultural Sciences Vol. 7 (1) 2008: pp. 7-
High-precision CTE measurement of hybrid C/SiC composite for cryogenic space telescopes
This paper presents highly precise measurements of thermal expansion of a
"hybrid" carbon-fiber reinforced silicon carbide composite,
HB-Cesic\textregistered - a trademark of ECM, in the temperature region of
\sim310-10K. Whilst C/SiC composites have been considered to be promising for
the mirrors and other structures of space-borne cryogenic telescopes, the
anisotropic thermal expansion has been a potential disadvantage of this
material. HB-Cesic\textregistered is a newly developed composite using a
mixture of different types of chopped, short carbon-fiber, in which one of the
important aims of the development was to reduce the anisotropy. The
measurements indicate that the anisotropy was much reduced down to 4% as a
result of hybridization. The thermal expansion data obtained are presented as
functions of temperature using eighth-order polynomials separately for the
horizontal (XY-) and vertical (Z-) directions of the fabrication process. The
average CTEs and their dispersion (1{\sigma}) in the range 293-10K derived from
the data for the XY- and Z-directions were 0.8050.003\times10
K and 0.837\pm0.001\times10 K, respectively. The absolute
accuracy and the reproducibility of the present measurements are suggested to
be better than 0.01\times10 K and 0.001\times(10)^{-6} K^{-1},
respectively. The residual anisotropy of the thermal expansion was consistent
with our previous speculation regarding carbon-fiber, in which the residual
anisotropy tended to lie mainly in the horizontal plane.Comment: Accepted by Cryogeincs. 12 pages, 3 figures, 1 tabll
The International Grief Questionnaire (IGQ): A new measure of ICD-11 Prolonged Grief Disorder.
Prolonged grief disorder (PGD) is included in the 11th version of the International Statistical Classification of Diseases and Related Health Problems (ICDâ11). This study sought to test the validity and reliability of a new brief measure to screen for ICDâ11 PGDâthe International Grief Questionnaire (IGQ). The psychometric properties of the IGQ were tested using data collected from two bereaved samples of adults from the United Kingdom (n = 1,012) and Ireland (n = 1,011). Confirmatory factor analysis demonstrated that a correlated twoâfactor model best captured the latent dimensionality of the IGQ in both samples. Estimates of internal reliability were high, whereas the convergent and concurrent validity of the scale were supported through strong associations with external measures. Measurement invariance and differential item functioning testing showed no statistically significant difference in the latent structure of the IGQ nor the functioning of the IGQ items by age, sex, and nationality. For participants who were bereaved for more than 6 months, the rates of probable PGD derived from the IGQ were 10.9% and 15.3% for the Irish and U.K. samples, respectively. The IGQ is a brief, easyâtoâuse, selfâreport screening measure that captures all diagnostic criteria of PGD set forth in the ICDâ11. Findings from this study provide initial support for the validity, measurement invariance, and reliability of the IGQ among two national samples
Assessing the validity and reliability of the International Anxiety Questionnaire and the International Depression Questionnaire in two bereaved national samples
Translation and validation of the Turkish forms of the International Depression Questionnaire (IDQ) and the International Anxiety Questionnaire (IAQ)
Prevalence and predictors of benevolent childhood experiences among a representative sample of young people
Depression trajectories among older community dwelling adults: Results from the Irish Longitudinal Study on Ageing (TILDA).
The Prevalence, Patterns and Correlates of Childhood Trauma Exposure in a Nationally Representative Sample of Young People in Northern Ireland
The co-occurrence of potentially traumatic events (PTEs) and their associations with posttraumatic stress disorder (PTSD) in Indian and Malaysian adolescents
High Precision CTE-Measurement of SiC-100 for Cryogenic Space-Telescopes
We present the results of high precision measurements of the thermal
expansion of the sintered SiC, SiC-100, intended for use in cryogenic
space-telescopes, in which minimization of thermal deformation of the mirror is
critical and precise information of the thermal expansion is needed for the
telescope design. The temperature range of the measurements extends from room
temperature down to 10 K. Three samples, #1, #2, and #3 were
manufactured from blocks of SiC produced in different lots. The thermal
expansion of the samples was measured with a cryogenic dilatometer, consisting
of a laser interferometer, a cryostat, and a mechanical cooler. The typical
thermal expansion curve is presented using the 8th order polynomial of the
temperature. For the three samples, the coefficients of thermal expansion
(CTE), \bar{\alpha}_{#1}, \bar{\alpha}_{#2}, and \bar{\alpha}_{#3} were
derived for temperatures between 293 K and 10 K. The average and the dispersion
(1 rms) of these three CTEs are 0.816 and 0.002 (/K),
respectively. No significant difference was detected in the CTE of the three
samples from the different lots. Neither inhomogeneity nor anisotropy of the
CTE was observed. Based on the obtained CTE dispersion, we performed an
finite-element-method (FEM) analysis of the thermal deformation of a 3.5 m
diameter cryogenic mirror made of six SiC-100 segments. It was shown that the
present CTE measurement has a sufficient accuracy well enough for the design of
the 3.5 m cryogenic infrared telescope mission, the Space Infrared telescope
for Cosmology and Astrophysics (SPICA).Comment: in press, PASP. 21 pages, 4 figure
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