Based on Lyapunov exponent criterion, the aircraft lateral-directional stability during critical flight cases is presented. A periodic motion or limit cycle oscillation isdisplayed. A candidate mechanism for the wing rock limit cycle is the inertia coupling between an unstable lateral-directional (Dutch roll) mode with stable longitudinal (short period) mode. The coupling mechanism is provided by the nonlinear interaction of motion related terms in the complete set equations of motion. To analyze the state variables of the system, the complete set of nonlinear equations of motion at different high angles of attack are solved. A novel analysis including the variation of roll angle as a function of angle of attack is proposed. Furthermore the variation of Lyapunov exponent parameter as function of time is introduced. The numerical result indicated that the system became lightly damped at high angle of attack with increasing the amplitude of aircraft state variables limit cycle. A good agreement between the numerical result and published work is obtained for the onset of limit cycle oscillation, almost at .
In this paper, preliminary test Shrinkage estimator have been considered for estimating the shape parameter α of pareto distribution when the scale parameter equal to the smallest loss and when a prior estimate α0 of α is available as initial value from the past experiences or from quaintance cases. The proposed estimator is shown to have a smaller mean squared error in a region around α0 when comparison with usual and existing estimators.
Willa Cather (1873-1947) sought to capture the gradation of human emotion through carefully selected descriptive and narrative touches and firmly controlled management of dramatic scenes, situations, dialogue, and point of view. Cather’s novels and stories drew increasingly upon her personal experiences and memories.
The old settlement of Virginia and the new lands of Nebraska formed the bedding ground for Willa Cather’s talents; so did the layers of memory she found across the North American continent, from New Mexico to Canada. She saw the full-blooded European immigrants, Czechs and Swedes, plowing the unbroken land, on the way up from peasants to proprietors.
 
... Show MoreBackground: Coated aesthetic archwires are currently the existing solutions for the esthetic problem, but the color of these archwires tends to change overtime. This study was aimed to evaluate the color stability of different types of esthetic archwires from four different companies at different time periods after immersion of two different staining drinks which are tea and Pepsi cola. Materials and methods: 48 specimens were prepared, each specimen contains 10 aesthetic archwires; and were divided according to type of solution into two groups: A (tea) &B (Pepsi cola); each group contained 24 specimens (12 specimens were immersed in the staining solution as 4 specimens for each time intervals and 12 specimens were immersed in distilled wa
... Show MoreBackground: Hodgkin’s Diseases is a group of cancers characterized by Reed- Sternberg cells, aneuoploid cells that usually express CD15 and CD30. Several epidemiological and serological studies support the role of Epstein –Barr virus in the pathogenesis of Hodgkin’s Diseases
Patients and Method: A retrospective study was done where by twenty cases were collected from the Pediatric Oncology Clinic in AL-Kadhyimia Teaching Hospital over a period of five years from the first of January 2002 – end of December 2006.Information was taken from the patient’s records in the Pediatric Oncology Clinic including age at presentation, sex, physical finding, histopathological subtypes, staging , treat
... Show MoreBack ground: This is a prospective study of Head injury in Najaf.
Aim: to study the causes & out come & way of transferring the rat to the hospital & best way to investigate them.
Patients & methods:A prospective analytical study of 200 cases of Head injury patients, who were admitted to Saddam Teaching Hospital , in Najaf between 18 t" of November 1996 and 1st of September 1998.
Results: All age groups were included in this study, male to female ratio was 4:1 and the highest incidence was seen at the age group below 14 years. The two most common causes of
head injury were road traffic accident (RTA)(51 %) and assault (22%),of RTA pedestrians accounted for (87.25%). RTA accounted of (8
Objective(s): to assess the effectiveness of educational program on nurses' knowledge concerning the side
effects of chemotherapy among children with leukemia.
Methodology: A descriptive analytic (quasi – experimental) design study was carried out at Baghdad City from
2
nd of October to 27th of June 2015. Non-probability sample of (35) male and female nurses was selected from
the Oncology Wards in Children Welfare, Child's Central and Baghdad Teaching Hospital. The study
instruments consisted of two major parts to meet the purposes of study. The first part is related to nurses'
demographic characteristics and the second part (four domains) is related to nurses' knowledge concerning the
side effects of chemothera
The historical center's landscape suffers from neglect, despite their importance and broad capabilities in enhancing the cultural value of the historical center, as landscape includes many heterogeneous human and non-human components, material and immaterial, natural and manufactured, also different historical layers, ancient, modern and contemporary. Due to the difference in these components and layers, it has become difficult for the designer to deal with it. Therefore, the research was directed by following a methodology of actor-network theory as it deals with such a complex system and concerned with an advanced method to connect the various components of considering landscape as a ground that can include various elements and deal wi
... Show MoreBreast cancer is the commonest cancer and the leading cause of malignancies-related mortality in women worldwide. Understanding the underlying biology of the disease could improve patients’ stratification and may offer novel therapeutic targets and strategies. This study was set to investigate the association between BRCA1 gene expression and some of the clinical features of breast cancer patients in Baghdad-Iraq. Eighty peripheral blood samples were collected from sixty patients diagnosed with breast cancer and twenty healthy age-matched controls for BRCA1 qPCR gene expression analysis.
The results showed a significant reduction in BRCA1 gene expression in all of the bre
... Show MoreNowadays, the development of internet communication and the significant increase of using computer lead in turn to increasing unauthorized access. The behavioral biometric namely mouse dynamics is one means of achieving biometric authentication to safeguard against unauthorized access. In this paper, user authentication models via mouse dynamics to distinguish users into genuine and imposter are proposed. The performance of the proposed models is evaluated using a public dataset consists of 48 users as an evaluation data, where the Accuracy (ACC), False Reject Rate (FRR), and False Accept Rate (FAR) as an evaluation metrics. The results of the proposed models outperform related model considered in the literature.