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Experimental study on the capillary water absorptivity of an aerogel-based coating mortar under subsequent drying and wetting cycles
No full textAerogel-based coating mortars with thermal conductivities ranging from 30 to 50\ua0mW/(m\ub7K) are an emerging type of thermal insulation coating mortar. They are intended for retrofitting uninsulated building envelopes due to their thermal performance which is comparable to conventional thermal insulation materials such as mineral wool. Meanwhile, their long-term hygrothermal performance and the reliability of the material properties are not fully demonstrated since these normally are declared based on single-cycle laboratory measurements. This paper presents laboratory measurements to determine the capillary water absorptivity of a commercial aerogel-based coating mortar after three consecutive wetting and drying cycles. The effect of the chosen drying (elevated versus room temperature) and sealing condition (sealed versus unsealed samples) on the measurement results were also assessed. The results show that the capillary water absorptivity of the samples increased after each repeated wetting and drying cycle regardless of the drying and sealing conditions. After three cycles, the measured capillary water absorption was more than five times higher than the initial measurement. Future research should investigate the causes of the observation and whether it applies to other aerogel-based coating mortars
The Event Horizon Telescope Image of the Quasar NRAO 530
Get PDFWe report on the observations of the quasar NRAO 530 with the Event Horizon Telescope (EHT) on 2017 April 5-7, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A*. At z = 0.902, this is the most distant object imaged by the EHT so far. We reconstruct the first images of the source at 230 GHz, at an unprecedented angular resolution of similar to 20 mu as, both in total intensity and in linear polarization (LP). We do not detect source variability, allowing us to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which we associate with the core. The feature is linearly polarized, with a fractional polarization of similar to 5%-8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 mu as along a position angle similar to -28 degrees. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field. Future EHT observations will probe the variability of the jet structure on microarcsecond scales, while simultaneous multiwavelength monitoring will provide insight into the high-energy emission origin
Ensemble Nonlinear Model Predictive Control for Residential Solar Battery Energy Management
Get PDFIn a dynamic distribution market environment, residential prosumers with solar power generation and battery energy storage devices can flexibly interact with the power grid via power exchange. Providing a schedule of this bidirectional power dispatch can facilitate the operational planning for the grid operator and bring additional benefits to the prosumers with some economic incentives. However, the major obstacle to achieving this win-win situation is the difficulty in 1) predicting the nonlinear behaviors of battery degradation under unknown operating conditions and 2) addressing the highly uncertain generation/load patterns, in a computationally viable way. This paper thus establishes a robust short-term dispatch framework for residential prosumers equipped with rooftop solar photovoltaic panels and household batteries. The objective is to achieve the minimum-cost operation under the dynamic distribution energy market environment with stipulated dispatch rules. A general nonlinear optimization problem is formulated, taking into consideration the operating costs due to electricity trading, battery degradation, and various operating constraints. The optimization problem is solved in real-time using a proposed ensemble nonlinear model predictive control-based economic dispatch strategy, where the uncertainty in the forecast has been addressed adequately albeit with limited local data. The effectiveness of the proposed algorithm has been validated using real-world prosumer datasets
Perfectoid Shimura varieties and the Calegari–Emerton conjectures
Get PDFWe prove many new cases of a conjecture of Calegari–Emerton describing the qualitative properties of completed cohomology. The heart of our argument is a careful inductive analysis of completed cohomology on the Borel–Serre boundary. As a key input to this induction, we prove a new perfectoidness result for towers of minimally compactified Shimura varieties, generalizing previous work of\ua0Scholze
How can pilot and demonstration plants drive market formation? Lessons from advanced biofuel development in Europe
Get PDFThis paper analyzes through what enabling mechanisms pilot and demonstration plants (PDPs) reduce supply and demand uncertainties, and thereby contributing to the market formation for novel sustainable technologies. The analysis builds on three case studies within the advanced biofuel development in Europe. For each case, we construct a narrative of the technology development and derive detailed insights into how technology actors use PDPs to drive market formation. We develop a comprehensive analytical framework, which highlights how PDPs contribute to supply uncertainty reduction through three main enabling mechanisms: building credibility for the technology, business ecosystem orchestration, and technology learning. The corresponding enabling mechanisms behind demand uncertainty reduction include technology standardization, constructing the narrative, and the creation of legitimacy for the technology. The paper also unfolds the composite activities of each mechanism, and outlines implications for technology developers, policymakers, as well as for the research community
Quantum Cryptography with Classical Communication: Parallel Remote State Preparation for Copy-Protection, Verification, and More
No full textQuantum mechanical effects have enabled the construction of cryptographic primitives that are impossible classically. For example, quantum copy-protection allows for a program to be encoded in a quantum state in such a way that the program can be evaluated, but not copied. Many of these cryptographic primitives are two-party protocols, where one party, Bob, has full quantum computational capabilities, and the other party, Alice, is only required to send random BB84 states to Bob. In this work, we show how such protocols can generically be converted to ones where Alice is fully classical, assuming that Bob cannot efficiently solve the LWE problem. In particular, this means that all communication between (classical) Alice and (quantum) Bob is classical, yet they can still make use of cryptographic primitives that would be impossible if both parties were classical. We apply this conversion procedure to obtain quantum cryptographic protocols with classical communication for unclonable encryption, copy-protection, computing on encrypted data, and verifiable blind delegated computation. The key technical ingredient for our result is a protocol for classically-instructed parallel remote state preparation of BB84 states. This is a multi-round protocol between (classical) Alice and (quantum polynomial-time) Bob that allows Alice to certify that Bob must have prepared n uniformly random BB84 states (up to a change of basis on his space). While previous approaches could only certify one- or two-qubit states, our protocol allows for the certification of an n-fold tensor product of BB84 states. Furthermore, Alice knows which specific BB84 states Bob has prepared, while Bob himself does not. Hence, the situation at the end of this protocol is (almost) equivalent to one where Alice sent n random BB84 states to Bob. This allows us to replace the step of preparing and sending BB84 states in existing protocols by our remote-state preparation protocol in a generic and modular way
FPGA Implementation of Multi-Layer Machine Learning Equalizer with On-Chip Training
Get PDFWe design and implement an adaptive machine learning equalizer that alternates multiple linear and nonlinear computational layers on an FPGA. On-chip training via gradient backpropagation is shown to allow for real-time adaptation to time-varying channel impairments
A survey on compositional algorithms for verification and synthesis in supervisory control
Get PDFThis survey gives an overview of the current research on compositional algorithms for verification and synthesis of modular systems modelled as interacting finite-state machines. Compositional algorithms operate by repeatedly simplifying individual components of a large system, replacing them by smaller so-called abstractions, while preserving critical properties. In this way, the exponential growth of the state space can be limited, making it possible to analyse much bigger state spaces than possible by standard state space exploration. This paper gives an introduction to the principles underlying compositional methods, followed by a survey of algorithmic solutions from the recent literature that use compositional methods to analyse systems automatically. The focus is on applications in supervisory control of discrete event systems, particularly on methods that verify critical properties or synthesise controllable and nonblocking supervisors
Stable trapping of multiple proteins at physiological conditions using nanoscale chambers with macromolecular gates
Get PDFThe possibility to detect and analyze single or few biological molecules is very important for understanding interactions and reaction mechanisms. Ideally, the molecules should be confined to a nanoscale volume so that the observation time by optical methods can be extended. However, it has proven difficult to develop reliable, non-invasive trapping techniques for biomolecules under physiological conditions. Here we present a platform for long-term tether-free (solution phase) trapping of proteins without exposing them to any field gradient forces. We show that a responsive polymer brush can make solid state nanopores switch between a fully open and a fully closed state with respect to proteins, while always allowing the passage of solvent, ions and small molecules. This makes it possible to trap a very high number of proteins (500-1000) inside nanoscale chambers as small as one attoliter, reaching concentrations up to 60 gL−1. Our method is fully compatible with parallelization by imaging arrays of nanochambers. Additionally, we show that enzymatic cascade reactions can be performed with multiple native enzymes under full nanoscale confinement and steady supply of reactants. This platform will greatly extend the possibilities to optically analyze interactions involving multiple proteins, such as the dynamics of oligomerization events
Expanding the genetic toolbox of Rhodotorula toruloides by identification and validation of six novel promoters induced or repressed under nitrogen starvation
Get PDFBACKGROUND: The non-conventional yeast Rhodotorula toruloides is an emerging host organism in biotechnology by merit of its natural capacity to accumulate high levels of carotenoids and intracellular storage lipids from a variety of carbon sources. While the number of genetic engineering strategies that employ R. toruloides is increasing, the lack of genetic tools available for modification of this yeast is still limiting strain development. For instance, several strong, constitutive R. toruloides promoters have been characterized, but to date, only five inducible promoters have been identified. Although nitrogen-limited cultivation conditions are commonly used to induce lipid accumulation in this yeast, no promoters regulated by nitrogen starvation have been described for R. toruloides. RESULTS: In this study, we used a combination of genomics and transcriptomics methods to identify novel R. toruloides promoter sequences that are either inducible or repressible by nitrogen starvation. RNA sequencing was used to assess gene expression in the recently isolated strain R. toruloides BOT-A2 during exponential growth and during nitrogen starvation, when cultivated with either glucose or xylose as the carbon source. The genome of BOT-A2 was sequenced using a combination of long- and short-read sequencing and annotated with support of the RNAseq data. Differential expression analysis was used to identify genes with a |log2 fold change|≥ 2 when comparing their expression during nitrogen depletion to that during exponential growth. The promoter regions from 16 of these genes were evaluated for their ability to drive the expression of a fluorescent reporter gene. Three promoters that were clearly upregulated under nitrogen starvation and three that were downregulated were selected and further characterized. One promoter, derived from gene RTBOTA2_003877, was found to function like an on-off switch, as it was only upregulated under full nitrogen depletion and downregulated in the presence of the nitrogen source. CONCLUSIONS: Six new R. toruloides promoters that were either upregulated or downregulated under nitrogen-starvation were identified. These substantially contribute to the available promoters when engineering this organism and are foreseen to be particularly useful for future engineering strategies requiring specific regulation of target genes in accordance with nitrogen availability