WIRELESS ANTENNA MULTIPLEXING USING TUNABLE ANTENNA FOR SPACE APPLICATIONS

Recent development in communication technologies shifts the communication paradigm from point to point to multi-user wireless systems. These developments eased the use of mobile telephone, satellite services, 5G cellular, smart application, and the Internet of Things. The proliferation of mobile devices has necessitated an elaborate mechanism to serve multiple users over a shared communication medium, and a multiplexing approach is introduced to serve this purpose. Multiplexing refers to a method that aims at combining multiple signals into one signal such that each user would be able to extract its desired data upon receiving the multiplexed signal. This spectrum sharing allows wireless operators to maximize the use of their spectrum to accommodate a large number of users over fewer channels. In Space applications, where sensors like temperature, attitude, IR, Magnetic, etc. send information using antennas operate at a different frequency, there is a need to collect all or some of these data using a single device. A wideband antenna requires a filtering process in order to remove unwanted signals that lead to a complex circuit design. Furthermore, the use of multiple antennas ends up with a larger size and additional complexity. Therefore, the tunable antenna is an excellent candidate which provides a perfect solution for such scenarios. A tunable antenna whose frequency characteristics shifted by applying tuning action can be used to operate as a multiplexing device that can collect signals from different surrounding antennas; each operates at a fixed frequency. A system architecture for wireless multiplexing using a tunable antenna is proposed in this project. An electronically tunable antenna using varactor diode as a tuning element is used as the multiplexing device that can collect signals from different surrounding antennas. The system consists of an RF front end and a control circuit/system for wireless multiplexing. The RF front end consists of a tunable antenna, tunable phase shifter, tunable bandpass filter, low noise amplifier, mixer, voltage-controlled oscillator, and an intermediate frequency filter. The control unit comprises a microcontroller, DAC, CMOS oscillator, power module, and a USB interface for communication with custom-built software installed on a PC. The device has functions for control, digital signal processing, and de-multiplexing. The device is fed with an input multiplexed signal, and the de-multiplexed output signals are extracted and displayed on the graphical user interface of the software. Due to the reconfigurability and programmability of the device, it presents a flexible, cost-effective solution for a variety of real-world applications

Adaptation of buildings to climate change: an overview

Buildings worldwide have evolved based on local resources and skills, evolving form and orientation to ensure a productive and comfortable indoor environment. Traditional habitations rely on passive climate-responsive mechanisms and physiological resilience. At the same time, contemporary buildings rely increasingly on active mechanisms for fine-tuned convenience and comfort. Those buildings are becoming less habitable due to climate change. This paper presents an overview of research into climate-responsive building adaptation, identifying various factors determining a building’s ability to regulate external climatic conditions in providing a habitable indoor environment. The review covers the ability of occupants to manage their thermal environment and adaptation mechanisms, including various adaptation strategies attributed to climate change. Besides a review of relevant research tools and methodologies, the paper also identifies future research challenges. Those challenges include but are not limited to evaluating climate classification provided by building standards given climate change, the need for region-specific climate-change vulnerability assessment of the built environment to develop specific adaptation strategies, a survey of vernacular structures to understand their inherent adaptation capacities, developing a framework to study building adaptation, etc. Thus, this review opens the possibility of further research in building adaptation

A role for p53 in terminal epithelial cell differentiation

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Geospatial variability of soil and climate on performance of rubber (Hevea brasiliensis Muell. Arg.) in traditional region of India

Natural rubber is grown in traditional region of India in varied soil and climate conditions. Earlier efforts to relate soil-site condition on performance of rubber were based on observation of few locations. Geospatial analysis of soil and climate variation helps to delineate constraint areas for site specific management. Kanyakumari district of Tamil Nadu and Kasaragod district of Kerala having contrasting soil and climate condition in traditional region of rubber cultivation were selected to study the effect of soil and climate on rubber performance. Soil OC, available P and K in Kanyakumari was in medium range whereas in Kasaragod soil OC was in high range, available P and K in low range. In Kanyakumari district major rubber growing area was under low elevation (0-100 m) and slope below 5-10 per cent compared to low to medium(100-200 m) elevation and slope above 5-10 per cent in Kasaragod. Annual rainfall distributed uniformly in Kanyakumari compared to unimodal rainfall distribution observed in Kasaragod. As a result Moisture Adequacy Index (MAI) in Kanyakumari during December to March was good to poor whereas in Kasaragod it was poor to very poor. Length of growing period was more in Kanyakumari compared to Kasaragod as a result performance of rubber with respect to growth and yield was better in Kanyakumari than Kasaragod. Factor analysis showed that soil health (OC) and cation (Ca and Mg) factors showed significant role in performance of rubber in Kanyakumari, whereas in Kasaragod only topographic factors i.e., elevation showed significant role in rubber performance

"The Chosen" - An Examination of Extremist Muslim Narratives, Discourse and Ideologies in Cyberspace

Ph.DDOCTOR OF PHILOSOPH

Analysis of Profitability of Commercial Dog Breeding Ventures in Thrissur and Ernakulam Districts of Kerala

Kerala's commercial dog breeding enterprise is a promising one with the potential to reduceyouth unemployment and provide a livelihood. However, the state lacks authentic information on factors affecting profitability of commercial dog breeding business. The present study was conducted to identify the association between factors that affect profitability of commercial dog breeding in Kerala. The study was conducted using an ex-post facto research design on 60 commercial dog breeding units selected randomly from Thrissur and Ernakulam districts of Kerala.Data collection was done using a pretested-structured interview schedule. Study revealed that years of experience, number of dogs reared, number of puppies born, cost of veterinary care, level of adoption and labour cost were correlated with profitability of commercial dog breeding enterprise

Finding subtypes of transcription factor motif pairs with distinct regulatory roles

DNA sequences bound by a transcription factor (TF) are presumed to contain sequence elements that reflect its DNA binding preferences and its downstream-regulatory effects. Experimentally identified TF binding sites (TFBSs) are usually similar enough to be summarized by a ‘consensus’ motif, representative of the TF DNA binding specificity. Studies have shown that groups of nucleotide TFBS variants (subtypes) can contribute to distinct modes of downstream regulation by the TF via differential recruitment of cofactors. A TFA may bind to TFBS subtypes a1 or a2 depending on whether it associates with cofactors TFB or TFC, respectively. While some approaches can discover motif pairs (dyads), none address the problem of identifying ‘variants’ of dyads. TFs are key components of multiple regulatory pathways targeting different sets of genes perhaps with different binding preferences. Identifying the discriminating TF–DNA associations that lead to the differential downstream regulation is thus essential. We present DiSCo (Discovery of Subtypes and Cofactors), a novel approach for identifying variants of dyad motifs (and their respective target sequence sets) that are instrumental for differential downstream regulation. Using both simulated and experimental datasets, we demonstrate how current motif discovery can be successfully leveraged to address this question