17 research outputs found
Development of a method to study aircraft trajectory optimisation in the presence of icing conditions
There is a growing demand for new technologies and
ight procedures that will enable
aircraft operators to burn less fuel and reduce the impacts of aviation on the environment.
Conventional approaches to trajectory optimisation do not include aircraft
systems in the optimisation set-up. However, the fuel penalty due to aircraft systems
operation is signi cant. Thus, applying optimised trajectories which do not account for
systems o -takes in real aircraft Flight Management System (FMS) will likely fail to
achieve a true optimum. This is more important in real scenarios where the ambient
conditions in
uence the systems operation signi cantly. This research proposed an ice
protection methodology which enables the development of a decision making process
within the FMS dependent on weather conditions; thus transforming the conventional
anti-icing method into a more intelligent system.
A case of a medium size transport aircraft
ight from London - Amsterdam under
various levels of possible icing was studied. The results show that fuel burn due to
anti-icing operation can increase up to 3.7% between climb and cruise altitudes. Up to
5.5% of this penalty can be saved using icing optimised trajectories. A 45% reduction
in awakenings due to noise was achieved with 3% fuel penalty. The novelty of the study
was extended using 3D optimisation to further improve
ight operations. It was found
that the simulation successfully changed the lateral position of the aircraft to minimise
the time spent and distance covered in icing conditions. The work here presents a
feasible methodology for future intelligent ice protection system (IPS) development,
which incorporates intelligent operation
Production, microbial and physico-chemical evaluation of ‘dawadawan botso’ (a condiment) produced by the fermentation of Hibiscus sabdariffa seeds
Production and physico-chemical characteristic of ‘dawadawan botso’ was evaluated. A decrease in pH was observed after the second fermentation from an initial pH of 8.10 after cooking to 7.63. The mean bacteria count was between 2.7x104 CFUg-1 to 1.7x106 CFUg-1. The organisms associated with fermented dawadawan botso were isolated and identified as Bacillus Pumilus, Bacillus subtilis, Brevibacillus laterosporus, Paenibacillus polymyxa, Bacillus amyloliquefaciens, Bacillus licheniformis, Brevibacillus brevis, Leuconostoc mesenteriodes, Lactobacillus plantarum, Pediococcus pentasaceus and Staphylococcus species. Bacillus species appear to be the dominant microflora involved in the fermentation. The proximate composition and mineral content revealed variations at (P < 0.05) level between unfermented and fermented seeds of H. sabdariffa with lipid having a value of 17.60 and 17.17%; protein value 15.94 and 25.19%; then carbohydrate was 37.96 and 15.98%. This suggests that ‘dawadawan botso’ is a good and cheap source of protein for the lower class, who cannot afford other expensive sources of proteins and its consumption may have health benefit due to the presence of probiotic bacteria.Keywords: Hibiscus sabdariffa, alkaline fermentation, proximate composition, mineral content, Bacillus sp, Lactic acid bacteri
Isolation and Identification of Air Borne Fungal Spores and Fragments in Buildings Within Usmanu Danfodiyo University Sokoto, Nigeria
- Indoor air contains a complex mixture of microorganisms, microorganism fragments, and by products such as molds, bacteria, endotoxins, mycotoxins, and volatile microbial organic compounds. Airborne fungi and bacteria can be toxic, allergenic and/or infectious. A research was conducted to determine the number and types of airborne fungal spores in Buildings of Usmanu Danfodiyo University Sokoto, Nigeria. Five (5) areas were chosen within the University for the Survey, these were student Hostel, Staff Quarters, Botanical garden, Microbiology laboratory and city campus of Usmanu Danfodiyo University. . A total number of fifteen (15) petri dishes containing potato dextrose agar each were vertically placed in each sampler and exposed at end of each height and site for 10 and 20 minutes respectively. A total of thirteen (13) different fungal specie were identified namely; Aspergillus Niger, A. flavus, A fumigates, A. ustus, A. terreus, Fusarium solani, F. oxysporum, Alterneria altenata, Rhizopus oryzae, R. stolonifer, Helminthosporum sp., Penicillum candidum and Absedia corymbifera. Aspergillus Niger had the highest frequency of occurrence of (14.9%), Helminthosporus species had the least frequency of occurrence of (1.5%). Conclusively it was observed that the concentration of fungal spores was high in the upper surface than the ground level at the time of the survey
Biocatalysis of H. sabdariffa during ‘dawadawan botso’ production and biogeneration of volatile compounds
The analysis of free amino acid and volatile compounds were conducted to understand how the fermenting organism’s biocatalyse H. sabdariffa seeds and its role in the biogeneration of free amino acids and flavour compounds in “dawadawan botso”. Fermentation increased the quantity of all essential amino acids except of threonine which decrease by 1.23 g/100 g protein. Arginine had the highest increase with a value of 3.06 g/100 g protein while proline had the least value of 0.22 g/100 g protein. Fermentation increased the total free amino acid from 68.32% to 76.79%. The values of bitter, sweet and MSG-like free amino acids in the unfermented seeds and “dawadawan botso” were different. A total of 22 compounds were identified from the fresh “dawadawan botso” and locally produced dried “dawadawan botso”. Predominant among them are Methyl (9Z) – 12- hydroxyl -9 –octadecenoate (40.66%) in fresh, Methyl (14E) – 14, 17- Octadecadienoate (33.97%) in dried and Cis -9- Hexedecenal (19.96%, 15.13%) in both samples. The compounds include alcohols, acids, esters, aldehydes, and alkanes. In this study, fermentation increased the bioavailability of free amino acids and volatile compounds in “dawadawan botso”.Keywords: “Dawadawan botso”, Fermentation, Free amino acids, GC-MS analysis, H. sabdariffa, Volatile flavor compound
Improving the operating efficiency of the more electric aircraft concept through optimised flight procedures
The increasing awareness of the environmental risks and costs due to the growing demand in aviation has prompted both academic and industrial research into short-term and long-term technologies which could help address the challenges. Among these, the more electric aircraft has been identified as a key design concept which would make aircraft more environmentally friendly and cost effective in the long run. Moreover, the notion of free-flight and optimised trajectories has been identified as a key operational concept which would help curb the environmental effects of aircraft as well as reduce overall costs. The research in this paper presents a methodology in which these two concepts can be coupled to study the benefits of more electric aircraft (MEA) flying optimised trajectories. A wide range of issues from aircraft performance, engine performance, airframe systems operation, power off-take penalties, emission modelling, optimisation algorithms and optimisation frameworks has been addressed throughout the study. The case study is based on a popular short haul flight between London Heathrow and Amsterdam Schiphol. The culmination of the study establishes the advantage of the MEA over conventional aircraft and also addresses the enhanced approach to the classical aircraft trajectory optimisation problem. The study shows that the operation procedures to achieve a minimum fuel burn are significantly different for a conventional aircraft and MEA. Trajectory optimisation reduced the fuel burn by 17.4% for the conventional aircraft and 12.2% for the more electric compared to the respective baseline cases. Within the constraints of the study, the minimum fuel burn trajectory for the MEA consumed 9.9% less fuel than the minimum fuel burn trajectory for the conventional aircraft
Comparative Analysis of Some Selected Natural Remedies on Dandruff Associated with Malassezia globosa
A comparative analysis was carried out on the levels of effectiveness of some selected natural remedies in inhibiting the growth of Malassezia globosa associated with dandruff. The natural remedies used in this research include; Potash, Neem leaves and Cloves. Scalp samples (Hair flakes) were collected from infected individuals with dandruff. Agar incorporation method was employed to test the efficacies of the three selected natural remedies against the growth of Malassezia globosa.,Three (3) species of Malassezia were obtained, these include; Malassezia globosa, Malassezia restricta and Malassezia furfur. Eleven (11) samples with 55% frequency of occurrence were positive for Malassezia globosa, five (5) samples with the percentage frequency of occurrence of (25%) were found to be positive for Malassezia furfur and 4 samples with the percentage frequency of occurrence of (20%) were found to be positive for Malassezia restricta. Catalase enzyme differential test between Malassezia globosa, Malassezia furfur and Malassezia restricta revealed catalase positive results with 11(55%) samples of Malassezia globosa and negative results with Malassezia furfur and Malassezia restricta. Potash was the most effective natural remedy in inhibiting the growth of Malassezia globosa than neem leaves and cloves extracts
Isolation and Identification of Fungi from Patients Attending Amanawa General Hospital Sokoto State, Nigeria
The research was conducted to investigate the mycological etiology, prevalence and distribution of fungal pathogens among patients with dermatological conditions attending Amanawa Hospital, Sokoto. A total number of thirty 30 samples were collected.Eight (8) species of fungi and one (1) genus were isolated these include; Trichophyton rubrum, Trichophyton concentricum, Trichophyton mentagrophytes, Microsporumferrgineum, Microsporumcanis, Microsporumaudounii, Aspergilusflavus, Aspergilusniger, Trichoderma and Penicilliumspp. Percentage frequency of occurrence of isolated fungi from female patients indicated that Microsporumcanis had the highest percentage frequency of 18.2% and the remaining species of fungi had the least percentage frequency of 9.1% each. The percentage frequency of occurrence of isolated fungi from male patients indicated that Trichophyton concentricum, M. ferrgineum, Mucorspp and Penicilliumspp had the highest percentage frequency of 12.5% while Trichophyton verrucosum, Trichophyton rubrum, Trichophyton schoenlenii, Microsporumcanis, Microsporumaudounii, Aspergilusniger, Candida albicans had the least percentage frequency of 6.3%.Occurrence of isolated fungi was found to be much in age group 11-13. With regard to gender, female patients are mostly affected than the male patients. There is therefore, the need for improved social, economic, health care and hygiene practice
Optimal sensor suite selection for helicopter enhanced vision in all-weather-all-environment operation using multi criteria decision making techniques
Optimum sensor selection for helicopter enhanced vision in all-weather operations is a strategic issue and has a significant impact on safety, efficiency and utility of military and Emergency Service Helicopters. On the other hand, selecting the optimal sensor among many alternatives is a multi-criteria decision-making (MCDM) problem. The sensor selection task in this paper is modelled as a stepwise Analytic Hierarchy Process (AHP) to guide the selection process, based on criteria relating to environmental conditions (fog, rain, dust) and sensor characteristics (detection range, update rate, resolution). Result of this study reveals that a combination of millimeter wave radar, passive millimeter wave camera and infrared camera is the optimal suite having the highest value among all the alternatives considered. This result will guide decision makers at the Headquarters of the Nigerian Air force and indeed other helicopter operators in their quest to equip helicopters for operation in adverse weather conditions
Prospects and Challenges of Propulsion Technologies of Unmanned Aerial Vehicles: A Review
This review paper discussed the different types of propulsion technologies for unmanned aerial vehicles (UAVs). In it, several UAV propulsion systems were investigated, with particular emphasis on internal combustion engine (ICEs)-powered propulsion systems and electrically powered propulsion systems. The characteristics and working principles of these propulsion systems and challenges were discussed in this paper. Also, the methods in which future generations of UAVs can perform better have been discussed particularly with regards to endurance characteristics, power-to-weight ratios, and environmental wise. Similarly, the relevance of future UAV propulsion systems, which is a hybrid of the two major propulsion systems (ICEs and electric systems), giving a yield for high endurance, long-range, and durability, is discussed
Malaria Prevalence in Gusau Township, Nigeria (A Preliminary Report)
This is comprehensive study of malaria and malaria infection in Gusau Township to generate baseline line information which may be useful in the planning control and preventive measures. A total of 5666 blood samples from patients were examined for malaria parasites between the month January to December, 2017, out which 2606 representing 46.0% were positive for malaria parasites, which was high. Both males and females were equally infected at the same rates and between the age groups. Malaria was hyperendemic in Gusau Township with transmission occurring throughout the months of the year. The best way to prevent malaria is avoiding mosquito bite through the use mosquito nets and screening of windows and doors