Evaluating the Rationale for Folding Wing Tips Comparing the Exergy and Breguet Approaches

The design and development processes for future aircraft aims to address the environmental and efficiency challenges needed to facilitate the engineering of concepts that are far more integrated and require a multidisciplinary approach. This study investigates the benefit of incorporating span extension wing tips onto future aircraft configurations as a method of providing improved aerodynamic efficiency, whilst allowing the extension to fold on the ground to meet airport gate size constraints. Although the actuated wing tips are not studied in detail, the focus of this study is to compare two different methods of analysis that can be used to identify the benefit and limitations of adding such devices. The two methods considered are a quasi-steady implicit energy analysis based on the Breguet Range Equation and an explicit energy analysis based on the first and second laws of thermodynamics known as Exergy Analysis. It has been found that both methods provide agreeable results and have individual merits. The Breguet Range Equation can provide quick results in early design, whilst the Exergy Analysis has been found to be far more extensive and allows the complete dynamic behaviour of the aircraft to be assessed through a single metric. Hence, allowing comparison of losses from multiple subsystems

Pilot modelling for airframe loads analysis

The development of large lightweight airframes has resulted in what used to be high frequency structural dynamics entering the low frequency range associated with an aircraft’s rigid body dynamics. This has led to the potential of adverse interactions between the aeroelastic effects and flight control, especially unwanted when incidents involving failures or extreme atmospheric disturbances occur. Moreover, the pilot’s response in such circumstances may not be reproducible in simulators and unique to the incident. The research described in this thesis describes the development of a pilot model suitable for the investigation of the effects of aeroelasticity on manual control and the study of the resulting airframe loads. After a review of the state-ofthe- art in pilot modelling an experimental approach involving desktop based pilot-in-the-loop simulation was adopted together with an optimal control based control-theoretic pilot model. The experiments allowed the investigation of manual control with a nonlinear flight control system and the derivation of parameter bounds for single-input-single-output pilot models. It was found that pilots could introduce variations of around 15 dB at the resonant frequency of the open loop pilot-vehicle-system. Sensory models suitable for the simulation of spatial disorientation effects were developed together with biomechanical models necessary to capture biodynamic feedthrough effects. A detailed derivation and method for the application of the modified optimal control pilot model, used to generate pilot control action, has also been shown in the contexts of pilot-model-in-the-loop simulations of scenarios involving an aileron failure and a gust encounter. It was found that manual control action particularly exacerbated horizontal tailplane internal loads relative to the limit loads envelope. Although comparisons with digital flight data recordings of an actual gust encounter showed a satisfactory reproduction and highlighted the adverse affects of fuselage flexibility on manual control, it also pointed towards the need for more incident data to validate such simulations

Integration of gender considerations in climate-smart agriculture R4D in South Asia: Useful research questions

Aimed at researchers working with climate-smart agriculture in South Asia, this resource suggests a set of issues to consider in relation to the integration of gender in climate-smart agricultural research for development. Climate change often exacerbates the problems and inequities that poor rural women face. The feminization of agriculture underscores the need to ensure that both men and women are able to learn about, try out, take up, and benefit from improved agricultural technologies, including climate-smart practices

Estimation of glacier surface velocity of Drang- drung glacier by DInSAR technique using Sentinel- 1 SLC SAR data

Glaciers are sensitive to climate change, especially the mountain glaciers due to their relatively small size they show rapid and fast changes to the ongoing trend of warming in climate. In the Himalayan region, the glaciers serve as important source of water for agriculture, power supply and tourism related activities. Glacier velocity gives information about the glacier health and helps in understanding the climate change, mass balance, and glacier dynamics. Differential SAR Interferometry (DInSAR) is the radar interferometry technique for measuring surface changes with a higher accuracy up to millimeter range. Velocity estimates are important to understand the glacier related hazards and can help in alleviating the possible future damage downslope. In this study, the velocity of one of the biggest and benchmark glaciers in Zanskar region has been estimated using DInSAR technique on Sentinel 1 SLC data. The results show that glacier has moved approximately 1m over a period of 12 days

SOCIAL RELATIONS AND SEED TRANSACTIONS AMONG SMALLSCALE MAIZE FARMERS IN THE CENTRAL VALLEYS OF OAXACA, MEXICO; PRELIMINARY FINDINGS

This paper explores social arrangements associated with seed transactions among small-scale maize farmers in the Central Valleys of Oaxaca, Mexico, a centre of crop genetic diversity. A formal seed distribution system has yet to develop in the region and when seed loss occurs, farmers are faced with costs and difficulties identifying, locating, and obtaining seed of desired varieties. For these reasons, it was hypothesized that there were strong incentives for collective action among farmers to facilitate seed supply. The study found, however, no evidence of collective action with regards to seed supply in the three study communities-San Pablo Huitzo, San Lorenzo Albarradas, Santa Ana Zegache. Instead, farmers acquired seed using a variety of networks of social relations and different types of seed transactions. The results suggest that seed flow among farmers in the Central Valleys of Oaxaca is a complex process of negotiation and reciprocity, influenced by a variety of agroecological, socioeconomic, and cultural factors.Farm Management,

Development of a pilot model suitable for the simulation of large aircraft

Effects of aeroservoelasticity on the manual control of large civil aircraft are investigated through a pilot modelling approach based on the modified optimal control model. A synopsis of modelling techniques is presented, followed by the description of the adopted technique. A simulation environment suitable for investigating pilot-vehicle dynamics in the longitudinal axis has been developed. The derivation of the pilot model was based on limiting the bandwidth. This approach showed that the pilot-vehicle system satisfied the crossover law between 3rad/s to 10rad/s for normal acceleration response. It was found that the pilot model and the low frequency tailplane bending mode introduced a resonant peak in the pilotvehicle frequency response that may be a cause for concern in high gain scenarios. Gust response simulations highlighted the contribution of fuselage bending mode on pilot perceived normal acceleration

Histomorphology of germ cell tumors at various anatomic sites: a 5 years study at a tertiary care centre

Background: Germ cell tumors (GCTs) are a heterogeneous group of neoplasms, which occur in the gonads, and at extra gonadal sites of the body. The aim of the study was to observe the different histopathological patterns of various GCTs in the body at all possible sites and to know their IHC staining patterns.Methods: The study was conducted for a period of 5 years from 2015 to 2019 and was an observational study. The recorded data was compiled and entered in a spreadsheet and then exported to data editor of SPSS Version 20.0. Continuous variables were expressed as mean SD and categorical variables were summarized as frequencies and percentages. Graphically the data was presented by bar and pie diagrams Chi-square test or Fisher’s exact test was applied for comparing categorical values. P<0.05 was considered statistically significant. All p values were 2 tailed.Results: A total of 93 cases were analyzed and the mean age of the patients was 27.8 years. Mature cystic teratoma was the most common histopathological variant and was mostly seen in the ovaries. There was a difference in age predilection of benign and malignant tumors. Most of the malignant GCTs were gonadal while EGCTs were likely to be benign. MGCTs (mixed GCTs) were mostly testicular in origin with only one MGCT being extragonadal.Conclusions: Mature cystic teratomas were the most frequent GCTs with frequent site being in ovaries. Out 0f 18 EGCTs only 2 were malignant, rest all were mature cystic teratomas.

Participatory research: a catalyst for greater impact

This paper discusses the notion of farmer empowerment as a primary objective of participatory research. The authors argue that agricultural technologies are adapted - not adopted – through a social and cultural process which includes the transformation of the technology. Farmer participation in agricultural research is important and necessary first of all to increase the efficiency and impact of agricultural research and technology development. This includes the identification of traits that can guide crop breeders’ work. Farmer empowerment is valuable and desirable, and while it can result from participatory research, direct empowerment per se should not be the main objective of participatory research conducted by research organizations. Of more importance is the empowerment of partner organizations and the identification of future research needs, i.e. the functional purposes of participatory approaches in agricultural research