There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

News and social media platforms have implicated dietary supplements in the treatment and prevention of coronavirus disease 2019 (COVID-19). During this pandemic when information quickly evolves in the presence of contradicting messages and misinformation, the role of the pharmacist is essential. Here, we review theoretical mechanisms and evidence related to efficacy and safety of select supplements in the setting of COVID-19, including vitamin C, vitamin D, zinc, elderberry, and silver. Evidence evaluating these supplements in COVID-19 patients is lacking, and providers and patients should not rely on dietary supplements to prevent or treat COVID-19. Rather, reference to evidence-based guidelines should guide treatment decisions.

https://journals.sagepub.com/doi/pdf/10.1177/1060028020928052

Myth Busters: Dietary Supplements and COVID-19.

A current transformer (CT) is accurately modeled for representation of the CT saturation effects on digital protective relays. Simulation studies performed in the PSCAD/EMTDC platform are used to investigate the impacts of CT saturation on the current phasor estimation. A new algorithm is also proposed for detection and compensation of CT saturation effects, based on: a least error squares (LES) filter which estimates the phasor parameters of the CT secondary current; a novel saturation detection method which uses the output of the LES filter for saturation detection; and a new minimum estimation error tracking approach which enhances the precision of the phasor estimation. The proposed saturation detection/compensation algorithm is independent of the parameters of the CT, the burden, and the power system. The study results show that the proposed algorithm: 1) reconstructs the distorted current waveform, under dc and ac saturation conditions, with the required precision and speed and 2) performs satisfactorily under inductive burden and under deep and slight saturation conditions.

/pdf/compensation-of-the-current-transformer-saturation-effects-aokm4uygzk.pdf

Compensation of the Current-Transformer Saturation Effects for Digital Relays

In this paper, we present the first automated system-level analysis of multicore CPUs based on ARMv8 64-bit architecture (8-core, 28nm X-Gene 2 micro-server by AppliedMicro) when pushed to operate in scaled voltage conditions. We report detailed system-level effects including SDCs, corrected/uncorrected errors and application/system crashes. Our study reveals large voltage margins (that can be harnessed for energy savings) and also large $V_{min}$ variation among the 8 cores of the CPU chip, among 3 different chips (a nominal rated and two sigma chips), and among different benchmarks.Apart from the $V_{min}$ analysis we propose a new composite metric (severity) that aggregates the behavior of cores when undervolted and can support system operation and design protection decisions. Our undervolting characterization findings are the first reported analysis for an enterprise class 64-bit ARMv8 platform and we highlight key differences with previous studies on x86 platforms. We utilize the results of the system characterization along with performance counters information to measure the accuracy of prediction models for the behavior of benchmarks running in particular cores. Finally, we discuss how the detailed characterization and the prediction results can be effectively used to support design and system software decisions to harness voltage margins for energy efficiency while preserving operation correctness. Our findings show that, on average, 19.4% energy saving can be achieved without compromising the performance, while with 25% performance reduction, the energy saving raises to 38.8%.CCS CONCEPTS• Hardware → Power and energy → Power estimation and optimization; • Hardware → Robustness → Hardware reliability → Process, voltage and temperature variations

Harnessing voltage margins for energy efficiency in multicore CPUs

Residues from the processing of cassava roots (Manihot esculenta Crantz), or cassava peels, are evaluated as chemically modified adsorbents with H2O2, H2SO4, and NaOH, in the removal of metal ions Cd(II), Pb(II), and Cr(III) from contaminated water. Modified adsorbents were chemically characterized for their chemical composition and (point of zero charge), while adsorption tests determined the best conditions of pH, adsorbent mass, and contact time between adsorbent and adsorbate in the process of removal of the metal ions. Isotherms obtained from the preliminary results were linearized by Langmuir’s and Freudlich’s models. The thermodynamic parameters, such as , , and , were also evaluated. The modifying solutions proposed were effective in the modification of adsorbents and resulted in high capacity sorption materials. Equilibrium time between adsorbent and adsorbate for the solutions contaminated with metals is about 40 minutes. The Langmuir model adjusted to most results, indicating monolayers adsorption of Cd(II), Pb(II), and Cr(III). The values obtained for Langmuir show a higher adsorption capacity caused by chemical modifications, with values such as 19.54 mg Cd(II) per g of M. NaOH, 42.46 mg of Pb(II) per g of M. NaOH, and 43.97 mg of Cr(III) per g of M H2O2. Results showed that modified cassava peels are excellent adsorbent, renewable, high availability, and low-cost materials and a feasible alternative in the removal of metals in industries.

/pdf/chemical-modifications-of-cassava-peel-as-adsorbent-material-1oyvtwe2n9.pdf

Chemical Modifications of Cassava Peel as Adsorbent Material for Metals Ions from Wastewater

The Power Integrity problem for high speed systems is discussed in context of selection and placement of decoupling capacitors. Power Integrity is maintained by damping the cavity mode peaks at resonant frequencies using decoupling capacitors. This article focuses on damping cavity mode effects in power delivery networks by the particle swarm optimization technique. The s-parameter data of power plane geometry and capacitors are used for the accurate analysis including bulk capacitors and VRM, for a real world problem. The optimal capacitors and their locations on the board are found using the presented methodology, which can be used for similar power delivery networks in high speed systems.

Selection and placement of decoupling capacitors in high speed systems

In this paper, we investigate the effect of four process parameters namely HALO implantation, compensation implantations, SiO2 thickness and silicide annealing time on threshold voltage (VTH) in complementary metal oxide semiconductor (CMOS) technology. The setting of process parameters were determined by Taguchi method in experimental design. The influence of the main process parameters on threshold voltage were determined using analysis of variance (ANOVA). The fabrication processes of the transistor were performed by a simulator namely ATHENA. The electrical characterization of the device was done by the a simulator of ATLAS. These two simulators were combined with Taguchi method to aid in design and optimizing process parameters. The other two parameter used in this experiments were Source/Drain (S/D) implantation dose and, silicide annealing temperature Threshold voltage (Vth) results were used as the evaluation parameters. The results show that the VTH value of 0.10308V and -0.10319V for NMOS and PMOS respectively. As conclusion, by utilizing Taguchi Method shown that process parameters can adjust threshold voltage (V TH ) to a stable value of 0.103V that is well within ITRS prediction for 32nm transistor

Application of Taguchi Method in the Optimization of Process Variation for 32nm CMOS Technology.

In this paper, we propose a novel microcantilever for biosensing applications, which we call a segmented cantilever. The aim of this paper is to show that the proposed design minimizes the disadvantages of the currently used micro-cantilevers.

/pdf/novel-cantilever-for-biosensing-applications-4gj0j985tg.pdf

Novel cantilever for biosensing applications

In this paper, we present a novel approach for fabricating piezoresistive silicon nitride cantilevers using polymer as an anchor. In our approach, the silicon nitride structural layers, as well as the polycrystalline silicon piezoresistive layer, are deposited by a low temperature hot-wire chemical vapor deposition process. The novelty of this process is that the silicon wafer is not consumed and is reusable, and the process also allows use of alternate materials for cantilever fabrication in place of silicon substrate. The fabricated silicon nitride cantilevers are characterized for their mechanical and electromechanical behavior.

Prakash R. Apte

Papers

Selection and placement of decoupling capacitors in high speed systems

Application of Taguchi Method in the Optimization of Process Variation for 32nm CMOS Technology.

Novel cantilever for biosensing applications

A Novel SU8 Polymer Anchored Low Temperature HWCVD Nitride Polysilicon Piezoresitive Cantilever

Structural and electrical properties of sodium bismuth titanate (Na0.5Bi0.5TiO3) thin films optimized using the Taguchi approach