Thermal expansion of composites using Moire interferometry

An experimental technique for precise measurement of the thermal response of fiber-reinforced composite materials uses moire interferometry with fringe multiplication which yield a sensitivity of 833 nm (32.8 mu in.) per fringe. Results from the technique are compared with those obtained from electrical resistance strain gages, and also those predicted from classical lamination theory. Temperature dependent coefficients of thermal expansion for composite materials subjected to thermal cycling in the temperature range of 297 K (75 F) to 422 K (300 F) were determined for four laminate configurations (0, 90, 0/ + or - 45/90 sub s and 0/90/ + or - 45 sub s) of T300/5208 graphite epoxy, and ranged from -0.107 mu epsilon K/1 (-0.059 mu epsilon deg F/-) for the 0 laminate to 32.18 mu epsilon K/1 (17.88 mu epsilon F/1) for the 90 laminate. Moisture was found to greatly influence the thermal response of a quasi-isotropic laminate, resulting in hysteresis and residual compressive strain as the moisture content was reduced. Comparisons between moire and strain gage measurements were inconclusive with both techniques giving consistent but systematically different results. Differences of as much as 29% were observed

Effect of Population Growth on Human Capital Development in Nigeria

Despite several studies on the impact of human capital development on economic development and studies on the impact of population growth on economic development, only a few studies have directly linked the impact of population growth on human capital development. In view of this, this study analyzes the causal relationship between population growth and human capital development from the period of 1970-2020. The primary school enrolment rate was set as a proxy for human development capital and the population growth rate used to measure population growth. In carryout the study, the Augmented Dicker Fuller test, was used to test for stationarity. The two variables were stationary at levels. The granger causality test was then carried out and results revealed bi-directional causality in that population growth granger caused human capital development and vice versa. This is a preliminary study that hopes to spur up more studies in this direction with specific interest to Nigeria. The policy recommendation is for massive investment in human capital along Lucas postulation and UNESCO education policy for developing nations like Nigeria

Impact of International Trade on Economic Growth in Nigeria

Using data from the World Development Indicator (WDI) and the Central Bank of Nigeria (CBN) Statistical Bulletin, this article analyzed the impact of exports, imports, the currency rate, and inflation on Nigeria’s economic development between 1981 and 2020. The research employed Autoregressive Distributed Lag (ARDL) bound testing methodology. The variables utilized in the study were evaluated for stationarity using the Augmented Dickey-Fuller and Philip Perron test, and the bound testing process was applied to the equations. The lag of variables test can be performed to determine the relationship between the variables. The outcome demonstrated that variables are stationary at first difference. Economy growth, exports and imports, exchange rate, and Inflation all exhibit long-term cointegration, as determined by a cointegration test. Export positively impacted on growth while inflation and exchange rate were found to be negatively affecting growth in Nigeria. The article indicates that there is a beneficial association between international commerce and economic growth and supports the policy of encouraging exports and expanding Nigeria’s presence on global markets

Model reduction of homogeneous-in-the-state bilinear systems with input constraints

Accepted versio

An outline of an asymmetric two-component theory of aspect

The paper presents the bases of an asymmetric two-component model of aspect. The main theoretical conclusion of the study is that (grammatical) viewpoint aspect and situation aspect are not independent aspectual levels, since the former often modifies the input situation aspect of the phrase/sentence. As it is shown, besides the arguments and adjuncts of the predicate, viewpoint aspect is also an important factor in compositionally marking situation aspect. The aspectual framework put forward in the paper is verified and illustrated on the basis of the aspectual system of Hungarian and some examples taken from English linguistic data

Models of classroom assessment for course-based research experiences

Course-based research pedagogy involves positioning students as contributors to authentic research projects as part of an engaging educational experience that promotes their learning and persistence in science. To develop a model for assessing and grading students engaged in this type of learning experience, the assessment aims and practices of a community of experienced course-based research instructors were collected and analyzed. This approach defines four aims of course-based research assessment—(1) Assessing Laboratory Work and Scientific Thinking; (2) Evaluating Mastery of Concepts, Quantitative Thinking and Skills; (3) Appraising Forms of Scientific Communication; and (4) Metacognition of Learning—along with a set of practices for each aim. These aims and practices of assessment were then integrated with previously developed models of course-based research instruction to reveal an assessment program in which instructors provide extensive feedback to support productive student engagement in research while grading those aspects of research that are necessary for the student to succeed. Assessment conducted in this way delicately balances the need to facilitate students’ ongoing research with the requirement of a final grade without undercutting the important aims of a CRE education