The transition to seawater desalination aiming at resource recovery, particularly in water- and energy-scarce regions, requires innovative approaches that consider societal benefits and costs. This study goes beyond traditional techno-economic evaluations by employing a Value-Sensitive Design (VSD) approach to integrate stakeholder values into the design and assessment of technical scenarios for integrated seawater desalination and brine treatment systems. The VSD approach guided the selection of performance indicators and informed the design of each scenario, ensuring that the scenarios are socially relevant by incorporating stakeholder values directly into the design process. Four technical scenarios were designed for the recovery of water and valuable materials from seawater, minimizing brine disposal, and dealing with trade-offs. Techno-economic models are implemented using Python to analyse the feasibility and performance of these scenarios. All scenarios achieved zero brine production. However, the trade-off between resource recovery and greenhouse gas emissions is evident, with scenarios emphasizing that increased salt recovery leads to larger CO2 emissions (locally) due to electricity consumption. Scenario 1 excelled in minimising electrical energy consumption, emissions, and maximising water production, while Scenarios 2 and 3 performed best in water and high-quality salt production. Despite its higher CO2 emissions, Scenario 4 proved most profitable due to the production of chemicals using only electricity-based technologies. These findings highlight the importance of tailoring plant designs to regional needs. The VSD approach provides a comprehensive understanding of trade-offs, offering new insights into how stakeholder values can guide the development of sustainable and context-specific desalination systems. This approach fosters dialogue with stakeholders and serves as a valuable tool for decision-makers.

A document by Rodoula Ktori. Click on the document to view its contents.

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In this work we present an automatic, deterministic procedure to fully design a metasurface antenna, self-consistently including the metallic feeding structure. The impedance pattern has full spatial variability in two dimensions, to allow designs otherwise difficult. The design is based on the integral-equation formulation with a current-only approach, in which the surface impedance profile is derived only after the optimal current is found; this allows to avoid the solution of the forward problem at all steps of the algorithm, with a drastic reduction of computational resources; it does not require any assumption on the impedance profile. We also show how a 3D feed can be accounted for in a hybrid scheme partially employing commercial 3D simulation software. Application examples address centerfed circular metasurface antennas, in which the feed is not connected to the metasurface, and rectangular "strip-like" leakywave antennas where the metasurface is electrically connected to the feeding surface. In all cases, the design is carried out up to the final layout, and the full antenna is simulated to verify the design.

A document by Eric J Earley. Click on the document to view its contents.

A document by Shekhar Kumar Yadav. Click on the document to view its contents.

Bit and power loading (BPL) algorithms played a pivotal role in the success of orthogonal frequency division multiplexing (OFDM) in digital transmission, including lightemitting diode (LED) based wireless optical communications. Nevertheless, the conventional BPL algorithms do not distinguish the nonlinear distortion generated in LED transmitters from an additive noise, which leaves room for improvement. This letter presents a novel power loading and two BPL algorithms that maximize the transmission capacity while minimizing the nonlinear distortion generated in LED. The effectiveness of the proposed algorithms is evaluated through simulations and transmission experiments, revealing a throughput increase of up to 10% in comparison to what can be achieved employing classical algorithms.

Environmental movements of the late 20th century resulted in sweeping legislation and regulatory actions to reduce the prevalence of diverse pollutants. Although the consequences of noise pollution to public health, the environment, and the economy have been recognized over the same time period, noise has received far less policy attention. Correspondingly, even while recent decades have seen robust advancements in assessing the impacts of noise pollution, solutions and actual reductions in environmental noise have remained seemingly out of reach. To address this shortcoming, we developed a prospectus for environmental noise reduction through technology-forcing policies. Technology-forcing describes intent to encourage technological solutions for pollution control through policy and regulations, and has been a critical component of national and global progress in reducing environmental pollutants. We take advantage of the unique policy history for noise in the United States - which initially enacted, but then abandoned federal noise regulation. We compare this history against outcomes from contemporaneous environmental legislation for air, water, and occupational pollution control, to demonstrate the potential for technology-forcing to reduce noise pollution. Our review then identifies promising solutions, in the form of existing technologies suitable for innovation and diffusion through technology-forcing regulations and incentives. Based on this review, we outline a program for noise policy development that is intended to support efforts to reduce environmental noise pollution worldwide. The proposed program consists of three steps, 2 which are to (i) identify dominant sources of noise pollution, (ii) combine legislative or regulatory provisions with suitable systems of enforcement and incentives, and (iii) anticipate and prepare for stages of technological change. This work is intended to support and advocate for noise policies designed around technology-forcing, to advance technologies that not only improve public health and sustainable development, but ensure that these benefits are distributed equitably.

Machine learning models are increasingly vital for clinical decision making. However, the integration of these models into health information systems (HISs) poses significant challenges, mainly due to the disparate formats of electronic health records (EHR) in various healthcare facilities. In response to this challenge, we proposed Model Cabinet Architecture (MoCab), a framework designed to leverage fast healthcare interoperability resources (FHIR) as the standard for data storage and retrieval when deploying machine learning models across various HISs. MoCab simplifies the deployment process by importing and configuring saved prediction models, facilitating patient data retrieval from FHIR servers, and transmitting it to the prediction model for analysis. The framework further incorporates Clinical Decision Support (CDS) Hooks for issuing clinical alerts and uses Substitutable Medical Apps Reusable Technologies (SMART) on FHIR to develop Apps for displaying laboratory results. Finally, MoCab offers the ability to continuously fine-tune and enhance the performance of deployed models over time. We demonstrate MoCab's efficacy through the successful integration of three model types, highlighting its potential in streamlining decision making amidst heterogeneous EHRs. Our proposed MoCab framework not only promotes the reusability of machine learning models across multiple EHRs but also contributes to improving clinical decision making, offering a promising solution to the challenges of integrating machine learning models into healthcare settings.

The foundations of nonlinear optics are revisited, and the formalism is applied to waveguide modes. The effect of loss and dispersion are included rigorously along with the vectorial nature of the modes, and a full derivation of a new version of the nonlinear Schrödinger (NLS) equation is presented. This leads to more general expressions for the group index, for the group-index dispersion (GVD), and for the Kerr coefficient. These quantities are essential for the design of waveguides suitable for e.g. the generation of optical frequency combs and all-optical switches. Examples are given using the silicon nitride material platform. Specifically, values are extracted for the coefficients of the chi-3 tensor based on measurements of Kerr coefficients and mode simulations.

IQ mixers and complex mixers are both used to cancel the image band signal. In this paper, we analyse a complex IF sub-THz receiver architecture aimed for splitting a multiGHz baseband signal into narrower sub-bands for easier A/D conversion. The architecture consists of a normal IQ direct downconversion, followed by complex mixers to center the chosen sub-carriers to DC. Image rejection versus mismatch errors is calculated both analytically and on system and circuit-level simulations. It was seen that the image rejection is dominated by the IQ downconversion stage. It is demonstrated that the mismatches in the IQ stage can be corrected digitally by weighted summing of the digital sub-bands.

In this publication, we analyze how the performance of propagation parameter estimation for THz channel sounding can be improved by the power spectrum design of a multicarrier waveform. To this end, we discuss the Fisher information of the propagation parameters and the corresponding deterministic Cramèr-Rao lower bound (CRB) as well as their relation to the carrier powers of the excitation signal. We use these quantities to design waveforms that improve range estimation. In practice, optimizing the power spectrum requires prior knowledge of the propagation scenario which is usually not available. Hence, we propose two solutions which we compare numerically to the classical approach of equal power distribution. The numerical evaluation shows that an optimized power distribution can improve the CRB comparable up to a 4 dB gain in SNR depending on whether knowledge about the scenario can be acquired in advance with an additional measurement. © 2023 IEEE.  Personal use of this material is permitted.  Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Nearly ideal vertical AlxGa1-xN (\(0.7\ \le x<1.0\)) p-n diodes are fabricated on an AlN substrate. Distributed polarization doping (DPD) was employed for both p-type and n-type layers of the p-n junction, instead of conventional impurity doping, to overcome the major bottleneck of AlN-based material: the control of conductivity. Capacitance-voltage measurements revealed that the net charge concentration agreed well with the DPD charge concentration expected from the device layer structure. The fabricated devices exhibited a low turn-on voltage of 6.5 V, a low differential specific ON-resistance of 3 mΩ cm2, electroluminescence (maximum at 5.1 eV), and an ideality factor of 2 for a wide range of temperatures (room temperature-573 K). Moreover, the breakdown electric field was 7.3 MV cm-1, which was almost twice as high as the reported critical electric field of GaN at the same doping concentration. These results clearly demonstrate the usefulness of DPD in the fabrication of high-performance AlN-based power devices.

Late-life balance disorders remain a severe problem with fatal consequences. Perturbation-based balance training (PBT), a form of rehabilitation that intentionally introduces small, unpredictable disruptions to an individual's gait cycle, can improve balance. The Tethered Pelvic Assist Device (TPAD) is a cable-driven robotic trainer that applies perturbations to the user's pelvis during treadmill walking. Earlier work showcased improved gait stability and the first evidence of increased cognition acutely. The mobile Tethered Pelvic Assist Device (mTPAD), a portable version of the TPAD, applies perturbations to a pelvic belt via a posterior walker during overground gait, as opposed to treadmill walking. Forty healthy older adults were randomly assigned to a control group (CG, n = 20) without mTPAD PBT or an experimental group (EG, n = 20) with mTPAD PBT for a two-day study. Day 1 consisted of baseline anthropometrics, vitals, and functional and cognitive measurements. Day 2 consisted of training with the mTPAD and post-interventional cognitive and functional measurements. Results revealed that the EG significantly outperformed the CG in several cognitive (SDMT-C and TMT-B) and functional (BBS and 4-Stage Balance: one-foot stand) measurements while showcasing increased confidence in mobility based on FES-I. To our knowledge, our study is the first randomized, large group (n = 40) clinical study exploring new mobile perturbation-based robotic gait training technology.

We propose a method to extract the equivalent material parameters and circuit models for all-metallic tensor metamaterials. The metamaterials consist of an arrangement of sub-wavelength metallic pins affixed to the bottom plate of an air-filled parallel plate waveguide (PPW). Isotropic and anisotropic configurations are studied, which are implemented with cylindrical and elliptical pins, respectively. The effective permittivity and permeability tensor of an equivalent lossless, homogeneous PPW are extracted. An equivalent circuit model consisting of series inductances and a shunt capacitance is also extracted. An analytical procedure to perform the extraction is outlined. The procedure is validated using full-wave simulations and circuit theory. Finally, representative designs are presented to show the effectiveness and potential applications of the proposed homogenization technique. The extraction of effective material parameters enables the control of the properties of all-metal metamaterials, enabling the design of perfectly-matched, anisotropic unit cells. Ultimately, the accurate mapping between all-metal metamaterials and their equivalent circuit networks could be exploited to accelerate the inverse design of multi-functional metastructures.

We introduce a new construction method of diffusion layers for Substitution Permutation Network (SPN) structures along with its security proofs. The new method can be used in block ciphers, stream ciphers, hash functions, and sponge constructions. Moreover, we define a new stream cipher mode of operation through a fixed pseudorandom permutation and provide its security proofs in the indistinguishability model. We refer to a stream cipher as a Small Internal State Stream (SISS) cipher if its internal state size is less than twice its key size. There are not many studies about how to design and analyze SISS ciphers due to the criterion on the internal state sizes, resulting from the classical tradeoff attacks. We utilize our new mode and diffusion layer construction to design an SISS cipher having two versions, which we call DIZY. We further provide security analyses and hardware implementations  of DIZY. In terms of area cost, power, and energy consumption, the hardware performance is among the best when compared to some prominent stream ciphers, especially for frame-based encryptions that need frequent initialization. Unlike recent SISS ciphers such as Sprout, Plantlet, LILLE, and Fruit; DIZY does not have a keyed update function, enabling efficient key changing.Â

Affective virtual reality (VR) gaming systems rely on timely physiological data collection, in order to generate personalized responses that enhance the emotional impact of a video game on its user. In this context, we propose a simple policy for timely data collection from wireless sensor nodes placed on the human body. Our policy is applied at each sensor node. Upon each packet arrival we check whether the buffer is full or not. If the buffer is full, then we empty it before adding the packet. In this very simple way, we avoid buffer congestion and impose timeliness. We simulated this aggressive buffer reset policy using a body area network (BAN) model in OMNeT++. By varying the packet generation rate of each node, we showed that our policy outperforms first come first served (FCFS) and last come first served (LCFS) queueing policies in terms of peak age, while packet reception is barely affected. Buffer resets can be easily integrated into existing random access protocols to support timely data collection.

Paper explaining measured conduction currents in a needle to plane gap in a mineral oil and an ester liquid when applying a high voltage. There are large differences between mineral oil and ester. Please use the accepted manuscript, DOI: 10.1109/TDEI.2024.3377178