A study of the optimal allocation of tolerances and clearances in planar linkage mechanisms

PhD ThesisThe work falls into two separate parts, involving respectively kinematic and dynamic aspects of planar linkage mechanisms. The first and major part reported in Part I concerns the development of a procedure for optimal allocation of tolerances and clearances in plane linkage mechanisms. The theory developed takes into account the sensitivity of the mechanism output to small deviations in the parameter dimensions and the cost-tolerance relationships for the parameters. A procedure is then derived from the theory and incorporated into a computer program to allocate tollerances to linear dimensions and angles, and clearances to the joints in the mechanism. To demonstrate the applicability of the method to a wide range of planar linkage mechanisms, a number of examples are given which include 4-, 6-, 8- and 10-bar linkages. Part II describes the investigation of possible methods for maintaining contact in the joints of a plane four-bar mechanism by means of mass redistribution, the aim being to reduce or eliminate vibration due to impact in joints with clearance. An optimization routine is used with constraints upon the magnitude of the joint forces and the rate at which those forces change direction based on a 'no-clearance' analysis. The method was applied to several examples with little success due to inherent limitations of the analysis method used.Kartoum Polytechnic

Agarwood classification based on odor profile using intelligent signal processing technique / Muhammad Sharfi Najib

This thesis presents the classification of Agarwood from Malaysia and Indonesia regions based on signal processing technique. Signal processing for the Agarwood classification is a new area and has yet been actively implemented. In this thesis, the Agarwood has been pre-identified by experts using 32 sensor arrays to measure the Agarwood odor profile. General Agarwood pattern has been plot in 2D diagram. The odor profile from different samples have been normalized and pre-processed and visualized in 3D and 2D plot to find unique patterns. The variation of patterns that has been visualized has been marked as different group samples

On Virtual Becoming and Belonging: Visualizing the Performativity of Sudanese Cultural Identity and Resistance

A contested history with turbulent political narratives has played a leading role in the formation of Sudanese identity. It is situated firmly in a romanticized past as it is in a troubled present. For the diaspora, social media platforms function as spaces for the continuous formation and expression of these identities. These platforms often serve as spaces to (re)produce the social and political relations that define everyday life in the homeland. This thesis explores the use of graphic design to discuss the performative articulation of these identities in virtual spaces. It follows understandings of identity from cultural studies as, always in production and never complete. By employing user- generated content found on online platforms for visual explorations, this thesis explores the ongoing dynamics between individual and collective narrations of identities; between personal reflections and public representations. The projects prepared discuss the complexities and nuances of Sudanese cultural identity online in the milieu of current political and social tensions. In the visual expression of Sudanese cultural identity, there is resistance, activism and a vision of triumph

Presentation of Invasive Fungal Rhinosinusitis in Sudanese Children: A Report of Four Cases

Fungal rhinosinusitis (FS) is considered as a disease spectrum that ranges from allergic fungal sinusitis (AFS) and chronic fungal rhinosinusitis (CFS) to invasive fungal rhinosinusitis (IFS) invading the orbit, Dura, and intra-cranium. Fungal rhinosinusitis is a common disease in Sudan. Objective: To present four rare cases of InvasiveFungal Rhinosinusitis in Sudanese children presented with orbital extension. Patients and Method: The authors have reported four cases of children in the age range of 9–11 years, two girls and two boys; they were presented with invasive fungal rhinosinusitis in Africa ENT hospital (Sudan) during the period from September 2015 to August 2017. Patients’ diagnosis was made by endoscopic examination, CT, and MRI,and it was confirmed by tissue biopsy. Results: Patients’ age range was 9–11 years, two girls and two boys. The unilateral disease was the commonest type. An orbital extension was detected in all cases on CT and MRI. No intracranial extension was detected. Aspergillus flavus was the most responsible agent detected in all the fourcases. Conclusion: Fungal rhinosinusitis (FS) is a common disease in adult Sudanese patients but rarely affects children. It is mainly caused by Aspergillus species. The disease is extensive and can be associated with orbital and intracranial complications

Storia: Summarizing Social Media Content based on Narrative Theory using Crowdsourcing

People from all over the world use social media to share thoughts and opinions about events, and understanding what people say through these channels has been of increasing interest to researchers, journalists, and marketers alike. However, while automatically generated summaries enable people to consume large amounts of data efficiently, they do not provide the context needed for a viewer to fully understand an event. Narrative structure can provide templates for the order and manner in which this data is presented to create stories that are oriented around narrative elements rather than summaries made up of facts. In this paper, we use narrative theory as a framework for identifying the links between social media content. To do this, we designed crowdsourcing tasks to generate summaries of events based on commonly used narrative templates. In a controlled study, for certain types of events, people were more emotionally engaged with stories created with narrative structure and were also more likely to recommend them to others compared to summaries created without narrative structure

E-Nose peranti yang boleh mengesan kemeruapan bau

Pekan, 30 Ogos- Bau merupakan salah satu fenomena yang tidak boleh disukat seperti mana kita menyukat berat, jarak, masa dan pelbagai lagi kuantiti fizikal yang lain tetapi boleh dibuat kalibrasi dengan peranti berpiawai. Bau adalah salah satu kesan yang terhasil daripada tindak balas yang berlaku daripada volatile organic compound (VOCs) atau kompaun organik yang meruap. Tindakbalas ini boleh berlaku daripada kompaun yang berada di dalam bentuk pepejal, cecair atau gas

The effect of family structure on adolescents in Saudi Arabia: a comparison between adolescents from monogamous and polygamous families

This study investigated the effects of family structure on 13-18 year-old adolescents in Saudi Arabia. Comparisons were made between adolescents from polygamous and monogamous families in psychological well-being (self-esteem, satisfaction with life, depression), bullying and victimization. A series of investigations assessed the effects of family structure and several demographic variables on adolescents’ psychological well-being and behaviour. Also, the mediating role of parent-adolescent relationships measured by parent-adolescent bonding and father availability was investigated. A systematic review of previous research established that few studies had investigated mediating variables, such as demographic variables. In the first study, comparisons were made between 98 adolescents from polygamous and monogamous families. Results found that adolescents from polygamous families reported more problems in their psychological well-being, bullying and victimization than adolescents from monogamous families. The aim of the second study was to establish the validity of the Parental Bonding Instrument for use with adolescents in Saudi Arabia. The parental bonding instrument was validated for use in Saudi society with 301 participants aged 13-18 years. Results found that the ‘care’ dimension of the parental bonding instrument was valid for use in Saudi Arabia but the ‘overprotection’ dimension was not considered to be culturally valid because of different cultural patterns found in Saudi culture. The third study compared 266 adolescents from polygamous and monogamous families using the validated parental bonding instrument. The results found that adolescents in polygynous families reported lower ‘care’ scores than those in monogamous families. Also, comparisons by age group and gender found no effects of age or gender for father care, mother care, self-esteem, satisfaction with life, bullying or victimisation. A significant difference was found between age groups for depression. The fourth study was conducted with 500 adolescents using structural equation modelling to test the role of the parent-adolescent relationship measured by parental bonding on adolescent self-esteem, satisfaction with life, depression, bullying and victimisation. For polygamous families, parental care was a significant mediating variable between adolescent outcomes and the family variables of father availability and the position of the mother as the first or later wife. For monogamous families, although parental care predicted adolescent outcomes, family variables did not affect parental care. The fifth study was a qualitative analysis of interviews with 30 adolescents and 10 teachers on perceptions of father fairness, family functioning, attitudes toward polygamous marriage and academic achievement. Problems reported for polygamous families were lack of father fairness and family cohesion, emotional and behavioural problems, and poor academic achievement. In conclusion, this thesis is the first study to investigate the effects of polygamous family structure on adolescents in Saudi society and the first to provide a culturally validated measure of adolescent-parent attachment relationships. It was found that polygamy affects adolescent psychological well-being and behaviour, also adolescents’ perceptions of parental care and the fairness with which they feel that their father treats them have important effects on their relationship with their parents, their sense of well-being and their behaviour. The findings will be valuable for educators, counsellors and psychologists in Saudi Arabia

Patterns and clinical presentation of Foreign Bodies in ENT among Sudanese Children in Khartoum state hospitals.

Abstract: -Background: Foreign bodies (FBs) in ENT are a common problem in Sudanese children and are associated with life threatening complications.Objectives: To study the patterns and presenting symptoms of children who are presented with foreign bodies Inhalation, Ingestion and insertion in the Nose and Ears.Methodology: This is a prospective hospital based descriptive study, conducted at Khartoum ENT Hospitals  from March 2013 to January 2015.Result: 150 patients with foreign bodies were studied in Khartoum ENT Hospitals. The commonest age group between 3–6 years in 64% of patients. Male to Female ratio is1.3:1.F.Bs  nose constituted higher percentage in (28%) of cases, F.Bs  inhalations were presented in(24.7%), F.Bs  ear were presented in (24.7%) and F.Bs  ingestion were presented in (22.7%).Regarding the type of inhalations, peanut was presented in (56.8%) of cases and the commonest presenting symptoms was cough in (94%) of patients.                                                                                                                                                                   Conclusion: Certain food items especially peanuts if given to children below the age of 2 years have to be given with caution and under close supervision. Bronchoscopy should always be considered in optimum conditions. Public health education is essential in order to prevent these avoidable problems.Key words:    F.Bs , ENT ,Khartoum.  

The Role of Iran and America's Middle East Policy in Peace Process of Middle East 2001-2016

Abstract The Middle East peace process has become the most important international Middle Eastern politics phenomenon during the recent decades. Since the U.S. has realized the political, military and economic power of Iran and its influence as peace building in the Middle East, diplomacy with a common approach on the agenda has developed between these two countries. Therefore, the purpose of this study is to investigate American and Iranian role in the Middle East and diplomatic relations between the two countries in the process of establishing peace in the region. The main question in the present research is that; what is the role of American and Iranian Middle East policy in the peace process in the Middle East during 2001-2016? To response to the question, a descriptive—analytical approach is implemented. The results suggest that the lack of diplomatic relations between Iran and America in the years 2001-2016 is one of the main reasons of the lack of security and peace in the Middle East. Accordingly, creating opportunities and establishing diplomatic relations (political, economic, social, and etc.) between Iran and America with the interests of the two countries as the two poles of influence in all parts of the region, not only provides security, but also is an indicator to stabilize discipline and a lasting peace in the region. Last but not least, communication between Iran and the U.S. ensures safety of the region