DESIGN OF AVIONICS AND CONTROLLERS FOR AUTONOMOUS TAKEOFF, HOVER AND LANDING OF A MINI-TANDEM HELICOPTER

Robotics autonomy is an active research area these days and promises very useful applications. A lot of research has been carried out on Vertical Takeoff and Landing (VTOL) vehicles especially single rotor small scale helicopters. This thesis focuses on a small scale twin rotor helicopter. These helicopters are more useful because of their power efficiency, scalability, long range of center of gravity, shorter blades and most importantly their "all lift" feature. By "all lift" we mean that unlike single rotor helicopters where tail rotor's power is wasted just to cancel the torque of the main rotor both of its rotors are used for generating lift. This makes twin rotors ideal for lifting heavy weights. This thesis considers avionics systems and the controllers development for a twin rotor. It involves electronic component selection and integration, software development, system identification and design of zero rate compensators. The compensators designed are responsible for autonomous take-off, hover and landing of this unmanned aerial vehicle (UAV). Both time and frequency domain system identification approaches were evaluated and a selection was made based on hardware limitations. A systematic approach is developed to demonstrate that a rapid prototyping UAV can be designed from cheap off-the-shelf components that are readily available and functionally compatible. At the end some modifications to existing mechanical structure are proposed for more robust outdoor hovering

Disaster in Bangladesh: A Multinational Relief Effort

Natural disasters have become a modus vivendi for the unfortunate people of Bangladesh. Floods, tropical cyclones, tornadoes, and tidal bores ravage the country almost every year. Annual monsoon flooding results in the loss of human life, damage to property and communication systems, and a shortage of drinking water leading to the spread of diseases. Similarly, severe cyclones accompanied by tidal surges cause colossal loss of life and property

Integrating BRT with Rickshaws in developing cities: a case study on Dhaka City, Bangladesh

Rickshaws (also known as cycle-rickshaw, becak, cyclos, samlors, pedicab in different countries) are available as a travel mode in many cities, particularly in Asia. There is evidence that in recent years, many cities (i.e. Jakarta, Surabaya, Karachi, Manila, Bangkok, Delhi, Dhaka) have tried to restrain or prohibit rickshaws either from the entire city or from certain roads or parts of the city and such bans have been highly controversial, opposed by environmentalists, rickshaw-pullers, and rickshaw users. An alternative approach to placing outright restrictions on rickshaws could be to integrate them into the formal public transport system by using them as feeder services. The aim of this research is to understand whether generally rickshaws can serve as a feeder service of bus rapid transit (BRT) systems. Detailed objectives are to identify what type of design for BRT station would require for modal integration and to explore if there is any possibility of fare integration between rickshaws and BRT, and to study the understanding of passengers’ and rickshaw-pullers’ views and policymakers’ opinions about the above mentioned aspects. The case studies for this research were conducted in two study locations in Dhaka city, Bangladesh. A system was designed whereby the rickshaws serve as feeder services to BRT. These designs were discussed with passengers and rickshaw-pullers as well as with transport professionals in Dhaka city. A three-dimensional (3-D) physical model of BRT station in study locations were prepared and presented in the focus group discussions (FGDs) so that a layperson could understand the proposed development and its spatial contexts. Results show that rickshaws could provide effective feeder services to BRT if the following points are addressed. The physical design of BRT stations should accommodate spaces for rickshaws for dropping off and picking up passengers, ensure not more than 200 m or 3 minutes of walk for modal interchanges between rickshaws and BRT, with better walking facilities and environment. Rickshaws should be well organised in terms of queuing at BRT stations. A pre-determined fare structure for rickshaws should be implemented. Above all, design of the new system should involve active involvement of the rickshaw-pullers and the public in the planning and decision-making process. Moreover, a 3-D physical model of the proposed BRT station helped effective participation during public consultation. This research provides a potential solution for a common problem of urban transport (arguments between fast and slow transport) that exists in many countries. The design of BRT station and policy measures derived from case study in Dhaka would be transferable in other ‘rickshaw city’, but should be based on assessment of the barriers and facilities of that city

Efficacy of Accelerated Streptokinase Infusion in the Treatment of St-Elevation Myocardial Infarction

OBJECTIVES To determine the efficacy of accelerated streptokinase (SK) in patients with acute ST-elevation myocardial infarction (STEMI). METHODOLOGY This Descriptive study was done in the Department of Cardiology, Hayatabad Medical Complex over a period of 6 months from august 2020 to February 2021. Age ranged between 35-70 years. Both males and females presenting with acute ST elevation MI, patients within 6 hours of the onset of chest pain were included in the study. RESULTS Among 144 patients age distribution was analyzed as 50(35%) patients were in age 35-50 years, and 94(65%) patients were in age 51-70 years. The mean age and standard deviation were 61± 8.19. Gender distribution was analyzed as 88(61%) patients were male and 56(39%) patients were female. Status of BMI was analyzed as 69(48%) patients had BMI ≤27 Kg/m2 and 75(52%) patients had BMI >27 Kg/m2. CONCLUSION The accelerated SK infusion regimen of 1.5 MU in 20 min is safe and well tolerated with significantly faster and higher clinical reperfusion rates, more preserved LV systolic function, less atrial and ventricular sustained arrhythmias, and less in-hospital and 1-year mortality rates in acute STEMI

Spectrum of perforation peritonitis in Pakistan: 300 cases Eastern experience

<p>Abstract</p> <p>Background</p> <p>Perforation peritonitis is the most common surgical emergency encountered by the surgeons all over the world as well in Pakistan. The spectrum of etiology of perforation peritonitis in tropical countries continues to differ from its western counter part. This study was conducted at Dow University of health sciences and Civil Hospital Karachi (DUHS & CHK) Pakistan, designed to highlight the spectrum of perforation peritonitis in the East and to improve its outcome.</p> <p>Methods</p> <p>A prospective study includes three hundred consecutive patients of perforation peritonitis studied in terms of clinical presentations, Causes, site of perforation, surgical treatment, post operative complications and mortality, at (DUHS&CHK) Pakistan, from 1st September 2005 – 1st March 2008, over a period of two and half years. All patients were resuscitated underwent emergency exploratory laparotomy. On laparotomy cause of perforation peritonitis was found and controlled.</p> <p>Results</p> <p>The most common cause of perforation peritonitis noticed in our series was acid peptic disease 45%, perforated duodenal ulcer (43.6%) and gastric ulcer 1.3%. followed by small bowel tuberculosis (21%) and typhoid (17%). large bowel perforation due to tuberculosis 5%, malignancy 2.6% and volvulus 0.3%. Perforation due to acute appendicitis (5%). Highest number of perforations has seen in the duodenum 43.6%, ileum37.6%, and colon 8%, appendix 5%, jejunum 3.3%, and stomach 2.3%. Overall mortality was (10.6%).</p> <p>Conclusion</p> <p>The spectrum of perforation peritonitis in Pakistan continuously differs from western country. Highest number of perforations noticed in the upper part of the gastrointestinal tract as compared to the western countries where the perforations seen mostly in the distal part. Most common cause of perforation peritonitis is perforated duodenal ulcer, followed by small bowel tuberculosis and typhoid perforation. Majority of the large bowel perforations are also tubercular. Malignant perforations are least common in our setup.</p

Waterpipe Smoking among Herat University Students: Prevalence, Attitudes, and Associated Factors

AbstractBackground: Waterpipe tobacco smoking (WTS) is an ancient type of smoking that has become a globalphenomenon. This study aimed to identify the prevalence of waterpipe smoking and its relation tosocio-demographic characteristics in Herat University students in western Afghanistan.Methods: In this cross-sectional study, a structured self-administered questionnaire containing 53 items in3 subscales was distributed between July and December 2018, to examine the use of waterpipe among HeratUniversity students. Data were evaluated in SPSS. Chi-square test was used to observe differences betweencategorical variables. All important variables were separately evaluated for men and women in logisticregression models. A P-value less than 0.05 was considered statistically significant.Findings: The prevalence of ever waterpipe use in male and female students was 54.1% and 81.8%,respectively. Parents’ higher education and family economic status were associated with higher rates of everwaterpipe use in both sexes. On the other hand, marital status and parents’ employment were not associatedwith waterpipe use. Ever waterpipe use was associated with having smoking friends or family members inboth sexes. Male and female waterpipe users believed that cigarette smoke had more nicotine thanwaterpipe. While more male waterpipe users believed that cigarette was more addictive than waterpipe, morefemale users believed otherwise.Conclusion: The prevalence of ever waterpipe use is higher in male students at Herat University. Having asmoking friend and family member positively influences waterpipe use among both sexes. Most usersbelieved that waterpipe smoking was less hazardous than cigarette smoking

Immense Industrialization And Their Air Prominent Pollutants Effect On Urban Air Quality Index

On the basis of the reported air quality index (API) and air pollutant monitoring data obtained at the Peshawar over the last seven years, the characteristics of air quality prominent pollutants and variation of the average annual concentrations of SO2, NO2total suspended particulate (TSP) fine particulates (PM10) CO and dust fall in Peshawar City were analyzed. Results showed that SO2and NO2were the prominent pollutants in the ambient air environment of Peshawar City. Of the prominent pollutants TSP accounted for nearly 63 % SO2, 32.8 ppb NO2, 147 ppb of CH4 , 13.8 ppb of CO, 94.5µg/m3of MC and 0.60 ppb of O3respectively in 2013. NO2to SO2 comparison ratio initially declined to 39.3 in 2009 and then starts to increase to 42.5 in 2010 while in 2013 reached upto 44.8 and O3 to SO2 ratio in the last year of observation, the ratio drop to 0.01830 µg/m3. Concentrations of air pollutants have shown a upward trend in recent years but they are generally worse than ambient air quality standards for EPA-USA, Pak and EU. SO2and NOx pollution were still serious impling that waste gas pollution from all kinds of vehicles had become a significant problem for environmental protection in Peshawar. The possible causes of worsening air quality were also discussed in this paper

Infectious aetiologies of neonatal illness in south Asia classified using WHO definitions: a primary analysis of the ANISA study.

BACKGROUND: Globally, neonatal mortality accounts for almost half of all deaths in children younger than 5 years. Aetiological agents of neonatal infection are difficult to identify because the clinical signs are non-specific. Using data from the Aetiology of Neonatal Infections in south Asia (ANISA) cohort, we aimed to describe the spectrum of infectious aetiologies of acute neonatal illness categorised post-hoc using the 2015 WHO case definitions of critical illness, clinical severe infection, and fast breathing only. METHODS: Eligible infants were aged 0-59 days with possible serious bacterial infection and healthy infants enrolled in the ANISA study in Bangladesh, India, and Pakistan. We applied a partial latent class Bayesian model to estimate the prevalence of 27 pathogens detectable on PCR, pathogens detected by blood culture only, and illness not attributed to any infectious aetiology. Infants with at least one clinical specimen available were included in the analysis. We assessed the prevalence of these aetiologies according to WHO's case definitions of critically ill, clinical severe infection, and infants with late onset, isolated fast breathing. For the clinical severe definition, we compared the prevalence of signs by bacterial versus viral aetiology. FINDINGS: There were 934 infants (992 episodes) in the critically ill category, 3769 (4000 episodes) in the clinical severe infection category, and 738 (771 episodes) in the late-onset isolated fast breathing category. We estimated the proportion of illness attributable to bacterial infection was 32·7% in infants in the critically ill group, 15·6% in the clinical severe infection group, and 8·8% among infants with late-onset isolated fast breathing group. An infectious aetiology was not identified in 58-82% of infants in these categories. Among 4000 episodes of clinical severe infection, those with bacterial versus viral attribution had higher proportions of hypothermia, movement only when stimulated, convulsions, and poor feeding. INTERPRETATION: Our modelled results generally support the revised WHO case definitions, although a revision of the most severe case definition could be considered. Clinical criteria do not clearly differentiate between young infants with and without infectious aetiologies. Our results highlight the need for improved point-of-care diagnostics, and further study into neonatal deaths and episodes with no identified aetiology, to ensure antibiotic stewardship and targeted interventions. FUNDING: The Bill and Melinda Gates Foundation

Causes and incidence of community-acquired serious infections among young children in south Asia (ANISA): an observational cohort study.

BACKGROUND: More than 500 000 neonatal deaths per year result from possible serious bacterial infections (pSBIs), but the causes are largely unknown. We investigated the incidence of community-acquired infections caused by specific organisms among neonates in south Asia. METHODS: From 2011 to 2014, we identified babies through population-based pregnancy surveillance at five sites in Bangladesh, India, and Pakistan. Babies were visited at home by community health workers up to ten times from age 0 to 59 days. Illness meeting the WHO definition of pSBI and randomly selected healthy babies were referred to study physicians. The primary objective was to estimate proportions of specific infectious causes by blood culture and Custom TaqMan Array Cards molecular assay (Thermo Fisher, Bartlesville, OK, USA) of blood and respiratory samples. FINDINGS: 6022 pSBI episodes were identified among 63 114 babies (95·4 per 1000 livebirths). Causes were attributed in 28% of episodes (16% bacterial and 12% viral). Mean incidence of bacterial infections was 13·2 (95% credible interval [CrI] 11·2-15·6) per 1000 livebirths and of viral infections was 10·1 (9·4-11·6) per 1000 livebirths. The leading pathogen was respiratory syncytial virus (5·4, 95% CrI 4·8-6·3 episodes per 1000 livebirths), followed by Ureaplasma spp (2·4, 1·6-3·2 episodes per 1000 livebirths). Among babies who died, causes were attributed to 46% of pSBI episodes, among which 92% were bacterial. 85 (83%) of 102 blood culture isolates were susceptible to penicillin, ampicillin, gentamicin, or a combination of these drugs. INTERPRETATION: Non-attribution of a cause in a high proportion of patients suggests that a substantial proportion of pSBI episodes might not have been due to infection. The predominance of bacterial causes among babies who died, however, indicates that appropriate prevention measures and management could substantially affect neonatal mortality. Susceptibility of bacterial isolates to first-line antibiotics emphasises the need for prudent and limited use of newer-generation antibiotics. Furthermore, the predominance of atypical bacteria we found and high incidence of respiratory syncytial virus indicated that changes in management strategies for treatment and prevention are needed. Given the burden of disease, prevention of respiratory syncytial virus would have a notable effect on the overall health system and achievement of Sustainable Development Goal. FUNDING: Bill & Melinda Gates Foundation