This article will address autoclave design considerations and
manufacturing working with high pressure low temperature
supercritical drying technique to produce silica aerogel. The design
elects carbon dioxide as a supercritical fluid (31.7 oC and 72.3 bar).
Both temperature and pressure have independently controlling
facility through present design. The autoclave was light weight (4.5
kg) and factory-made from stainless steel. It contains a high pressure
window for monitoring both transfer carbon dioxide gas to liquid
carbon dioxide and watching supercritical drying via aerogel
preparation process. In this work aerogel samples were prepared and
the true apparent densities, total pore volume and pore size
distribution, BET surface area, spectroscopic refractive index,
structure and thermal properties have been systematically
investigated characteristic.
MH Hamzah, AF Abbas, International Journal of Early Childhood Special Education, 2022
A large number of researchers had attempted to identify the pattern of the functional relationship between fertility from a side and economic and social characteristics of the population from another, with the strength of effect of each. So, this research aims to monitor and analyze changes in the level of fertility temporally and spatially in recent decades, in addition to estimating fertility levels in Iraq for the period (1977-2011) and then make forecasting to the level of fertility in Iraq at the national level (except for the Kurdistan region), and for the period of (2012-2031). To achieve this goal has been the use of the Lee-Carter model to estimate fertility rates and predictable as well. As this is the form often has been familiar
... Show MoreBased on the diazotization-coupling reaction, a new, simple, and sensitive spectrophotometric method for determining of a trace amount of (BPF) is presented in this paper. Diazotized metoclopramide reagent react with bisphenol F produces an orange azo-compound with a maximum absorbance at 461 nm in alkaline solution. The experimental parameters were optimized such as type of alkaline medium, concentration of NaOH, diazotized metoclopramide amount, order additions, reaction time, temperature, and effect of organic solvents to achieve the optimal performance for the proposed method. The absorbance increased linearly with increasing bisphenol F concentration in the range of 0.5-10 μg mL-1 under ideal conditions, with a correlati
... Show MoreIn our article, three iterative methods are performed to solve the nonlinear differential equations that represent the straight and radial fins affected by thermal conductivity. The iterative methods are the Daftardar-Jafari method namely (DJM), Temimi-Ansari method namely (TAM) and Banach contraction method namely (BCM) to get the approximate solutions. For comparison purposes, the numerical solutions were further achieved by using the fourth Runge-Kutta (RK4) method, Euler method and previous analytical methods that available in the literature. Moreover, the convergence of the proposed methods was discussed and proved. In addition, the maximum error remainder values are also evaluated which indicates that the propo
... Show MoreSoil water use and water storage vary by vegetative management practices, and these practices affect land productivity and hydrologic processes. This study investigated the effects of agroforestry buffers (AB), grass buffers (GB), and biofuel crops (BC), relative to row crops (RC) on soil water use for a claypan soil in northern Missouri, USA. The experiment located at the Greenley Memorial Research Center included RC, AB, GB, and BC established in 1991, 1997, 1997, and 2012, respectively. Soil water reflectometer sensors installed at 5‐, 10‐, 20‐, and 40‐cm depths monitored soil water from April to November in 2017 and 2018. Results showed significant differences in weekly volumetric water content (VWC) among treatments for all fou
... Show MoreThe tests that measure special strength defined by speed contributes a great deal in evaluating the players' weaknesses and strengths so as to aid coaches judge their players according to scientific and objective measurements. The problem of the study lies in answering the following question : is there a test that measures legs' vertical strength defined by speed especially for youth basketball players? The aim of the research was to construct and standardize a test for measuring legs' vertical strength defined by speed in youth basketball. The subjects of the study were 74 youth basketball players from Baghdad. The researchers concluded that the test measures leg's vertical strength defined by speed for youth basketball players as well as
... Show MoreThere are different types of young isolated NSs: radio pulsars, compact central X-ray sources in supernova, magentas: anomalous x-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs).This paper shows that the value of magnetic field (B), characteristic age ( ), spin down luminosity ( equilibrium period ( and Flux density ( ) was determined depending on some properties of pulsar star, such as the value of period of the pulsar (P) and the time derivative period ( for sample stars which were adopted. The model that which adopted is Hallo Cone Model. The results showed that the Normal pulsar stars have a big magnetic field, equilibrium period and Spin down than the Millisecond pulsar stars.But Millisecond pulsar stars have large values of
... Show MoreOstracode assemblages have been utilized for the study of the paleoecology of
the Maastrichtian – Upper Eocene succession (Hartha, Shiranish, Aaliji, Kolosh,
Jaddala and Avanah formations) in North and Iraq, represented by five sections,
including four boreholes, Anah well-2, Mityaha well-1, Makhul well-2,
Chemchemal well-2 and Jabel Sinjar outcrop section. According to the different
environmental factors affecting on the ostracode ecology, such as salinity, depth,
temperature, oxygenation, substrate and food supply; and depending on the
distribution of ostracode assemblages within the studied sections, nine ecofacies
have been recognized indicating shallow brackish or brackish- marine water, neritic
marine,