Joint demodulation of low-entropy narrowband cochannel signals

Introducation to cochannel signals: many receivers today operate in an interference-limited environment. In a dense signal environment, the performance of a receiver is limited by interference from multiple signals at the receiver rather than signal-to-noise ratio. In the interference-limited environment, there is a diminishing return from investing additional resources into improving traditional receiver parameters such as noise figure. Advanced processing techniques exist that can help recover information that would otherwise be lost using a single-channel receiver. This work investigates some of these techniques. Interference may originate from many sources, such as users on the same or adjacent frequency band, unintended emissions, and intermodulation. This work investigates interference from cochannel information bearing signals. Cochannel interference is commonly defined as the reception of two or more signals at the receiver overlapping in frequency and in time.USA

The potential of Citizen Science for Natural Capital and Ecosystem Services assessment in agri-environmental systems

Citizen science (CS), broadly understood as public participation in scientific research, has been rapidly growing in many fields of application and with different foci, encompassing approaches such as community-based monitoring, citizen observatories, and volunteered geographic information, amongst others. Recently, linkages of CS with Ecosystem Services (ES) and Natural Capital (NC) approaches have been explored, uncovering existing links as well as identifying ways in which CS can help advance such approaches. National strategy plans, including the UK’s Natural Capital and Ecosystem Assessment, are also starting to recognise CS as one important building block for data collection and implementation of such plans. This presentation will situate CS in relation to ES and NC approaches focusing on agri-environmental systems, outlining the current state of understanding and highlighting several areas in which CS can provide tested methods and mechanisms to the NC/ES field including integration with national NC/ES assessment frameworks, using CS for NC/ES research and modelling as well as establishing localised approaches, such as community-based and co-developed NC/ES monitoring and management networks and programmes. We will provide use cases from agriculture and natural resource management across the globe, including from the FRAMEwork project, to illustrate the examples, and outline challenges and opportunities for future applications. Parallels will also be drawn to related sustainability-focused concepts and assessment frameworks, such as the Sustainable Development Goals and the Post-2020 Global Biodiversity Framework, where the potential of CS to contribute to official indicator monitoring as well as goal and target level implementation has been studied in-depth and demonstrated by several examples. Policy pathways and recommended roadmaps developed for linking the SDGs with citizen science will further illuminate the potential of CS for enriching NC and ES framing and assessmen

P.A.M. Dirac and the Discovery of Quantum Mechanics

Dirac's contributions to the discovery of non-relativistic quantum mechanics and quantum electrodynamics, prior to his discovery of the relativistic wave equation, are described

Citizen science and farmer-led innovation at the frontiers of farming and biodiversity

Agriculture is a key frontier for ensuring planetary health and conserving and promoting biodiversity. The EU project “FRAMEwork” (2020-2024) is helping farmer groups, so-called ‘farmer clusters’, with a shared interest in monitoring biodiversity on their farms in partnership with researchers and local communities as well as implementing more biodiversity-friendly farming at a landscape scale. In eleven active farmer clusters from Spain to Estonia, the project is combining two concepts, stemming from different practice domains: Farmer Clusters and Citizen Observatories. The combination of the two concepts aims to maximise the strengths of both and create a strong, evidence-based, locally embedded community approach to biodiversity protection and enhancement by enabling the integration of structured monitoring with adaptive land management practices. In this poster, we present a summary of the approach including different pathways to link farmer-led innovation via farmer clusters at a landscape scale with the Citizen Observatory concept as well as some intermediary results of the project

Ionization of 1D and 3D oriented asymmetric top molecules by intense circularly polarized femtosecond laser pulses

We present a combined experimental and theoretical study on strong-field ionization of a three-dimensionally oriented asymmetric top molecule, benzonitrile (C$_7$H$_5$N), by circularly polarized, nonresonant femtosecond laser pulses. Prior to the interaction with the strong field, the molecules are quantum-state selected using a deflector, and 3-dimensionally (3D) aligned and oriented adiabatically using an elliptically polarized laser pulse in combination with a static electric field. A characteristic splitting in the molecular frame photoelectron momentum distribution reveals the position of the nodal planes of the molecular orbitals from which ionization occurs. The experimental results are supported by a theoretical tunneling model that includes and quantifies the splitting in the momentum distribution. The focus of the present article is to understand strong-field ionization from 3D-oriented asymmetric top molecules, in particular the suppression of electron emission in nodal planes of molecular orbitals. In the preceding article [Dimitrovski et al., Phys. Rev. A 83, 023405 (2011)] the focus is to understand the strong-field ionization of one-dimensionally-oriented polar molecules, in particular asymmetries in the emission direction of the photoelectrons.Comment: 12 pages, 9 figure