A numerical investigation is adopted for two dimensional thermal analysis of rocket thrust chamber wall (RL10), employing finite difference model with iterative scheme (implemented under relaxation factor of 0.9 for convergence) to compute temperature distribution within thrust chamber wall (which is composed of Nickel and Copper layers). The analysis is conducted for different boundary conditions: only convection boundary conditions then combined radiation, convection boundary conditions also for different aspect ratio (AR) of cooling channel. The results show that Utilizing cooling channels of high aspect ratio leads to decrease in temperature variation across thrust chamber wall, while no effects on heat transferred to the coolant is indicated. The radiation has a considerable effect on the computed wall temperature values.
Apical meristems, lateral buds, anthers of immature flowers and immature embryos of chickpea ( Cicer arietinum L.) were cultured on MS media with different growth regulators and incubated for 6 weeks at 25-27?C with 16 hrs photoperiod for callus initiation. Results indicated that 1 and 0.1 mg/l of 2,4-D and BA were suitable for callus initiation when apical meristems and lateral buds were used. While 2 and 0.5 mg/l of both growth regulators were essential for immature embryos. It was noticed that using chickpea anthers of the MS medium must contain 1mg/l 2ip and 0.5 mg/l IAA. However, MS medium supplemented with 1-3 mg/l of BA and 2,4-D respectively was good for callus initiation from lateral buds, anther and immature embryos.
... Show MoreComputer programs are one of the most prominent features of technical progress in the field of information technology, which has raised many new issues that have not existed since the mid-twentieth century. and controls on the use of these programs by third parties, Controversy still exists about the legal nature of computer programs between those who believe that they are subject to the laws of patents and industrial property, and those who believe that they are subject to the laws of copyright protection and literary and artistic property, and the resulting difference in the scope of protection and rights established according to the legal system adopted in the application. This study comes to shed light on the legal nature of computer
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A graph
is said to be singular if and only if its adjacency matrix is singular. A graph
is said to be bipartite graph if and only if we can write its vertex set as
, and each edge has exactly one end point in
and other end point in
. In this work, we will use graphic permutation to find the determinant of adjacency matrix of bipartite graph. After that, we will determine the conditions that the bipartite graph is singular or non-singular.
The present study introduces the concept of J-pure submodules as a generalization of pure submodules. We study some of its basic properties and by using this concept we define the class of J-regular modules, where an R-module M is called J-regular module if every submodule of M is J-pure submodule. Many results about this concept are proved
Cesarean section, which was introduced into clinical practice as a lifesaving procedure for both the mother and the baby, is one of the most common surgeries performed in modern obstetrics. Formerly it was performed in interest of the mother; currently it is frequently done for fetal indication. As other procedures of some complexity, its use follows the health care inequity pattern of the world; underuse in low income setting, and adequate or even unnecessary use in middle and high income setting (1).
The first modern cesarean section was performed by German gynecologist Ferdinand Adolf Kehrer in 1881. Cesarean section is often performed when a vaginal delivery would put the baby's or mother's life or health at risk. Many are also pe
The reclamation of makeup water is studied in terms of breakthrough time (i.e., the leakage of the cations). Makeup water was subjected to lab-scale ion exchangers of two types: strong acid cation and weak base anion exchanger. The experimental investigation was directed to study the ion exchanger performance in terms of four different parameters (i.e., copper concentration, total dissolved solids (TDS), feed rate and bed depth). Box-Wilson composite rotatable design was adopted in designing the experiments. Breakthrough times of the effluent stream are measured in terms of copper concentration of 2 to 25 ppm, TDS concentration of 250 to 1250 ppm, feed rate of 0.38 to 5.34 l/h and bed depth of 5 to 70 cm. Simulation the effect of the stu
... Show MoreBackground To evaluate the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of ultrasonographic and doppler US findings in the
diagnosis of acute appendicitis.
Method : A total of 115 cases of clinically suspected appendicitis were prospectively examined by grey scale US and doppler US. Five patients were excluded from the study because of
difficulty to perform the graded compression technique. In the other 115 patients who were included in the study population , US appendiceal and periappendiceal signs, as well as doppler US findings were evaluated. Definitive diagnosis was established at surgery and histopathological examination in 62 patients (59
In this paper, we discuss the difference between classical and nonclassical symmetries. In addition, we found the non-classical symmetry of the Benjamin Bona Mahony Equation (BBM). Finally, we found a new exact solution to a Benjamin Bona Mahony Equation (BBM) using nonclassical symmetry.
The research deals with a new type of high-performance concrete with improved physical properties, which was prepared by using metal additives minutes (Metakaolin) and by studing their impact on the properties of mortar and concrete high-performance through destructive and non destructive tests. This type of concrete is used broadly in public buildings and in other structures . The research involved a number of experiments such as finding the activity index of burned at a temperature of 750 º C according to the standard ( ASTM C-311/03), as well as casting models for the cubic mortar mixtures and concrete containers at different rates of metakaolin ranging between (5% - 20%) as an added part to the cement mix to get a high- compressive
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