Aircraft Materials and Analysis

Note: This pdf only includes chapter 1 and 10. Complete coverage of aircraft design, manufacturing, and maintenance Aircraft Materials and Analysis addresses aircraft design, mechanical and structural factors in aviation, flight loads, structural integrity, stresses, properties of materials, compression, bending, and aircraft fatigue. Detailed analysis of the failure process is provided. This authoritative guide examines materials used in aircraft construction such as aluminum, steel, glass, composite, rubber, and carbon fiber. Maintenance procedures for corrosion and aging aircraft are discussed and methods of inspection such as nondestructive testing and nondestructive inspection are described. Accident investigation case studies review aircraft design, material behavior, NTSB findings, safety, stress factors, and human factor involvement. End-of-chapter questions reinforce the topics covered in this practical resource. Aircraft Materials and Analysis covers: The aircraft--standards for design, structural integrity, and system safety Aircraft materials Loads on the aircraft Stress analysis Torsion, compression, and bending loads Aircraft riveted joints and pressure vessels Heat treatments of metals Aircraft fatigue/aircraft material fatigue Aircraft corrosion Dynamic stress, temperature stress, and experimental methods Composites Nondestructive Testing (NDT) Aviation maintenance management Case studies and human factor

Clinical outcomes of surgically corrected atrial septal defects

Objective: To examine the outcomes of surgical repair of atrial septal defects in paediatric and adult patients. Methods: The retrospective study comprised data of 84 patients who had undergone surgical correction of atrial septal defect at the Aga Khan University Hospital, Karachi, between June 2006 and December 2011. All patients with isolated atrial septal defect (ostium secundum, ostium primum and sinus venosus with or without partial anomalous pulmonary venous connection) were included. Clinical and transthoracic echocardiographic data was reviewed. SPSS 17 was used for statistical analysis. Results: There were no deaths in the study population. The mean time for follow-up was 6.5±9.9 months. Most of the patients (n=80; 95.2%) were in New York Heart Association class I at follow-up, while the remaining 4(4.8%) were in New York Heart Association class II. Post-operatively, 8 (9.5%) patients developed brief episodes of arrhythmias. There were 3 (3.57%) patients who were re-admitted within 30 days; 2 (66.7%) had superficial wound infection, while 1 (33.3%) had to be re-opened because of cardiac tamponade. Conclusion: Surgical repair of atrial septal defects is a safe procedure which is associated with excellent results and low morbidity

Aviation Maintenance Management

Note: This pdf only includes chapter 1 and 18. THE COMPLETE, UP-TO-DATE GUIDE TO MANAGING AIRCRAFT MAINTENANCE PROGRAMS Thoroughly revised for the latest aviation industry changes and FAA regulations, this comprehensive reference explains how to establish and run an effi cient, reliable, and cost-effective aircraft maintenance program. Co-written by Embry-Riddle Aeronautical University instructors, Aviation Maintenance Management, Second Edition offers broad, integrated coverage of airline management, aircraft maintenance fundamentals, aviation safety, and the systematic planning and development of successful maintenance programs. LEARN HOW TO: Minimize service interruptions while lowering maintenance and repair costs Adhere to aviation industry certification requirements and FAA regulations Define and document maintenance activities Work with engineering and production, planning, and control departments Understand the training requirements for mechanics, technicians, quality control inspectors, and quality assurance auditors Identify and monitor maintenance program problems and trends Manage line and hangar maintenance Provide materiel support for maintenance and engineering Stay on top of quality assurance, quality control, reliability standards, and safety issue

Major, Minor and Trace Elements Existence in Surface Sediments from Gwadar to Jiwani Coastal Areas of Pakistan

This study was carried out along the western coastal parts of Balochistan from Gwadar east Bay to Jiwani. The local anomaly of major, minor and trace elements were studied in this area. Zone-I (Gwadar east and west Bay) indicates that calcium oxide, potassium oxide and titanium dioxide have higher or average concentrations, while ZoneII indicates higher or average concentrations of calcium oxide, titanium dioxide and ferric oxide. Trace elements zirconium, chromium, europium, strontium, and copper are in higher or average concentrations in both zones. Gwadar west Bay and Jiwani are intermediate in carbonate, which show a high degree of maturity, suggesting the high rate of weathering in the source area. Sediment samples from Ganz, Jiwani, and Gwadar east Bay represent the quartz-rich fields in this region. Gwadar east Bay has a positive correlation between aluminium oxide and potassium oxide which suggests that abundance of potassium oxide is controlled by variation in K-feldspar contents. A positive correlation between strontium and calcium oxide suggests that strontium is associated with calcium oxide in biogenic carbonate material in Gwadar west Bay. The positive correlation between aluminium oxide, copper, and zinc in Pishukan indicates that the abundance of these elements is due to limited silt and clay fractions present in sediments. Enrichment factor shows that chromium and strontium are probably of anthropogenic origin in this region. Keyword

Kimura’s disease of head and neck: A rare case presentation

Kimura\u27s disease (KD) is a rare, unusual occurrence, predominantly seen in Asian men, and poses a diagnostic challenge, often manifesting with allergic, eosinophilic hyperplasia, and nonspecific lymphadenitis. A 39-year-old man presented with mobile, well circumscribed, facial and neck swelling. His earlier biopsy showed a reactive lymph node hyperplasia on ultrasound neck and was suggestive of lipomatosis. As definitive diagnosis could not be made, the patient was planned for excision and biopsy. Subsequent histopathology demonstrated eosinophilic infiltration of lymphoid follicles and expansion of interfollicular area with interfollicular eosinophilic abscess formation and capillary venule proliferation. This was quite interesting as the previously diagnosed case of nonspecific lymphadenitis based on biopsy later turned out to be a rare occurrence of KD. Furthermore, because of other systemic symptoms (pedal edema and eye irritation), which probably reflected generalized manifestations of KD, the patient was referred to a rheumatologist after diagnosis, where he was effectively managed with immunotherapy and steroids

Complications of in-patient cerebral angiography: Comparison between patients with and without sub arachnoid haemorrhage

Objective: To compare complications of cerebral angiography among patients with and without subarachnoid haemorrhage.Methods: This retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised records of patients undergoing inpatient therapeutic and diagnostic cerebral angiographies from 2001 to 2010. The patients were divided into subarachnoid and non-subarachnoid haemorrhage groups. During the study period no modifications were made to the operational protocol and all patients were subjected to the same procedure and prophylactic care.Results: Of the 93 patients, 42(45.2%) were women and 51(54.8%) were men. The overall mean age was 45.27±16.15 years (range: 4-80 years). The comparison between the two groups regarding new onset of neurological deficit was statistically significant (p=0.001). However, the same comparison regarding drop in Glasgow Coma Scale was statistically not significant (p=0.073).Conclusions: The rate of neurological complications was higher in patients with subarachnoid haemorrhage

Hospital Service Quality and Patient Satisfaction: A Moderating Role of Trustworthiness

 The aim of the present study is to determine the effects of hospital service qualities on patient satisfaction in the healthcare sector of Pakistan. By using the non-probability sampling, 292 sample was gathered. Emotional exhaustion, organizational citizenship behavior, hospital and nurses facilities were used as predictors and trustworthiness was used as a moderator. The results from structural equation modeling revealed that hospital facilities quality and OCB have been found positively significant while nursing service quality and emotional exhaustion have been found insignificant in relation with patient satisfaction. Moreover, trustworthiness does not moderates any relationship in the structural model. The study concluded that the staff allocated is manifesting form of behavioral citizenship structured by cultural decorum and locally acceptable norms. Alongside citizenship, high quality miscellaneous supportive provisions comprising of sufficient backup equipment, medical apparatus and tools as well as the regular maintenance of utilities stand as considerable satisfaction determining aspects for patients. The cognitive dimensions in the form of trust structuring attributes don’t really add much to the contributions of facilities and citizenship found in hospitals

Tetralogy of Fallot with absent pulmonary valve syndrome; appropriate surgical strategies

Abstract OBJECTIVE: To evaluate patients presenting with Tetralogy of Fallot with absent pulmonary valve syndrome to a tertiary care hospital and their surgical management. METHODS: The retrospective study was conducted at Congenital Cardiac Services, Aga Khan University Hospital, Karachi, Pakistan, and comprised data of Tetralogy of Fallot patients between April 2007 and June 2012. Data was analysed together with follow-up echocardiography. Variables assessed included demographics, imaging, operative technique, complications, post-operative recovery and follow-up echocardiography. SPSS 17 was used for statistical analysis. RESULTS: Of the 204 patients, 6 (3%) had undergone surgical correction for Tetralogy of Fallot with absent pulmonary valve syndrome. All 6(100%) patients underwent complete repair. Median age for surgery was 8.5 years (range: 0.5-29 years). Of the different surgical strategies used, Contegra and Bioprosthetic valve placement had satisfactory outcome with minimal gradient at Right Ventricular Outflow Tract, good ventricular function and mild valvular regurgitation. One (16.6%) patient with Trans Annular Patch developed post-operative Right Ventricle Outflow Tract gradient of 80mmHg with moderate pulmonary regurgitation. One (16.6%) patient with monocusp valve developed free pulmonary regurgitation at 6 months. The other 4(66.6%) patients are currently free from any complications or re-intervention. CONCLUSIONS: Early surgery is preferred in symptomatic patients. The repair depends upon achieving integrity of pulmonary circulation which is best achieved by using right ventricle to pulmonary artery conduit or inserting a pulmonary valve

Hepatitis B virus subgenotypes D1 and D3 are prevalent in Pakistan

<p>Abstract</p> <p>Background</p> <p>As the hepatitis B genotyping is important for assessing its clinical implications and geographical distribution, the sub-genotypes have been found useful for determination of specific genomic markers related to hepatocarcinogenesis. In Pakistan, there is no reported data on molecular evolutionary analysis of HBV. A study was, therefore, much needed to evaluate the spectra of mutations present in the strains prevalent here.</p> <p>Findings</p> <p>to confirm specificity of PCR typing, phylogenetic analysis of the pre-S1 region and the divergence was studied through 13 sequences of 362 bp (accession number <ext-link ext-link-type="gen" ext-link-id="EF432765">EF432765</ext-link> – <ext-link ext-link-type="gen" ext-link-id="EF432777">EF432777</ext-link>). A total of 315 serum samples, selected from HBsAg positive patients representing the major ethnic groups, residing in Karachi, Sindh were tested for genotyping. Genotype D (219/315) was found to be the most prevalent (70%) amongst our patients. The rest of the genotypes A and a mixture of A and D (AD) were distributed as 20%, and 10% respectively. Phylogenetic tree demonstrated clustering of 11 samples with subgenotype D1 sequences and the remaining two strains on a branch within D3 samples. All samples intermixed with strains from other countries and were found to be closely related to Indian, Iranian and Egyptian HBV strains with 98.7 – 99.0% homology.</p> <p>Conclusion</p> <p>This study confirms the predominance of genotype D in southeastern Asia and presence of subgenotypes DI and D3 in the Pakistani infected patients. More studies are required to investigate the reason for fewer inclusions of D3 compared to the D1 in Pakistani HBV strains.</p

Malignant pheochromocytoma with widespread bony and pulmonary metastases

Pheochromocytoma is a rare benign tumor of the adrenal gland. A select few cases may be malignant, and metastatic cases are exceedingly rare. It often presents with symptoms of catecholamine excess, such as sweating, palpitations, headaches, and characteristic paroxysmal hypertension. Due to its diffuse symptoms, it is difficult to diagnose and is often diagnosed late. We describe the unique case of a 44-year-old female patient who presented with uncontrolled hypertension and vomiting, accompanied by lower back pain. She was diagnosed with malignant pheochromocytoma with multiple metastases to the lungs, vertebrae, scapulae, and skull. Because of the advanced state of her disease, the patient was started on treatment with the chemotherapeutic combination of cyclophosphamide, vincristine, and dacarbazine. However, she had a complicated hospital course and died because of aspiration pneumonia and sepsis