Curing of concrete is the maintenance of a satisfactory moisture content and temperature for a
period of time immediately following placing so the desired properties are developed. Accelerated
curing is advantages where early strength gain in concrete is important. The expose of concrete
specimens to the accelerated curing conditions which permit the specimens to develop a significant
portion of their ultimate strength within a period of time (1-2 days), depends on the method of the
curing cycle.Three accelerated curing test methods are adopted in this study. These are warm water,
autogenous and proposed test methods. The results of this study has shown good correlation
between the accelerated strength especially for the proposal curing test method and normal strength
using normal curing method at ages 7 and 28 day for the five different chemical composition of
cement with different water to cement ratios equal to 0.45, 0.55, 0.65 and 0.75. Linear and
nonlinear regression analysis show high correlation for the different types of the accelerated curing
methods with coefficient of correlation (R2) more than 0.9.
The vegetable cover plays an important role in the environment and Earth resource sciences. In south Iraq, the region is classified as arid or semiarid area due to the low precipitations and high temperature among the year. In this paper, the Landat-8 satellite imagery will be used to study and estimate the vegetable area in south Iraq. For this purpose many vegetation indices will be examined to estimate and extract the area of vegetation contain in and image. Also, the weathering parameters must be investigated to find the relationship between these parameters and the arability of vegetation cover crowing in the specific area. The remote sensing packages and Matlab written subroutines may be use to evaluate the results.
Doppler broadening technique is suggested to monitor the development of tumours. It depends on the sensitivity of positronium (Ps) annihilation parameters to the sub- microstructural changes in biological tissues. This technique uses high resolution HpGe detector to measure the lineshape parameters (S and W) in normal mice's mammary tissues and adenocarcinoma mammary tissues as a function of tumour growth. The results demonstrate that the central parameter (S) decreases and the wing parameter (W) increases as the tumour grow. It is found that the S parameter changes considerably with the distribution of voids which are affected by the tumour development. Therefore the present technique can successfully be employed to monitor the developm
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The methods of the Principal Components and Partial Least Squares can be regard very important methods in the regression analysis, whe
... Show MoreThis paper study two stratified quantile regression models of the marginal and the conditional varieties. We estimate the quantile functions of these models by using two nonparametric methods of smoothing spline (B-spline) and kernel regression (Nadaraya-Watson). The estimates can be obtained by solve nonparametric quantile regression problem which means minimizing the quantile regression objective functions and using the approach of varying coefficient models. The main goal is discussing the comparison between the estimators of the two nonparametric methods and adopting the best one between them
The sunrise, sunset, and day length times for Baghdad (Latitude =33.34º N, Longitude =44.43º E) were calculated with high accuracy on a daily basis during 2019. The results showed that the earliest time of sunrise in Baghdad was at 4h: 53m from 5 Jun. to 20 Jun while the latest was at 7h: 07m from 5 Jan. to 11 Jan. The earliest time of sunset in Baghdad was at16 h: 55m from 30 Nov. to 10 Dec. whereas the latest was at 19h: 16m from 25 Jun. to 5 Jul. The minimum period of day length in Baghdad was 9h: 57m) in 17 Dec. whereas the maximum period was 14h: 22m) in 20 Jun. Day length was calculated and compared among regions of different latitudes(0, 15, 30, 45 and 60 north).
The photooxidative degradation process of plastics caused by ultraviolet irradiation leads to bond breaking, crosslinking, the elimination of volatiles, formation of free radicals, and decreases in weight and molecular weight. Photodegradation deteriorates both the mechanical and physical properties of plastics and affects their predicted life use, in particular for applications in harsh environments. Plastics have many benefits, while on the other hand, they have numerous disadvantages, such as photodegradation and photooxidation in harsh environments and the release of toxic substances due to the leaching of some components, which have a negative effect on living organisms. Therefore, attention is paid to the design and use of saf
... Show MoreBackground: The clinical examination is one of the best suitable methods for diagnosis of low backache. Backache is one disease that the signs, clinical examination finding, and the results on imaging modalities not always related. The straight leg raising (SLR) and slump tests, can be used for diagnosis of lumber disc herniation. Objectives: To compare the result of the slump test and SLR test in the diagnosis of lumber disc herniation. Subjects and Methods: A prospective comparative study conducts on 280 patients in Al-Kindy teaching and private clinics complaints of backache, aging between 18-70 years old with acute or recurrent backache, sciatica pain, or low back and sciatica pain for last 12 weeks, while patients
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