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Despite efforts to apply administrative and engineering controls to minimize worker exposure to aerosols, filtering facepiece respirators (FFRs) continue to be an important form of personal protective equipment in hard-to-control settings such as healthcare, agriculture, and construction. Optimizing the performance of FFRs can be advanced with the use of mathematical models that incorporate the forces that act on particles during filtration as well as those filter characteristics that influence filter pressure drop. However, a thorough investigation of these forces and characteristics using measurements of currently available FFRs has not been undertaken. Filter characteristics such as fiber diameter and filter depth were measured from samples taken from six currently-available N95 FFRs from three manufacturers. A filtration model was developed that included diffusion, inertial and electrostatic forces to estimate the filtration of an aerosol with a Boltzmann charge distribution. The diameter of the filter fibers was modeled as either a single "effective" diameter or as a lognormal distribution of diameters. Both modeling schemes produced an efficiency curve that simulated efficiency measurements made over a range of particle diameters (0.01 − 0.3 µm) with the use of a scanning mobility particle sizer in the region where efficiency is at a minimum. However, the method using a distribution of fiber diameters produced a better fit for particles > 0.1 µm. The coefficients associated with a simple form of the diffusion equation constituting a power law incorporating the Peclet number were adjusted to enhance model accuracy. Likewise, the fiber charge of the electret fibers was also adjusted to maximize model fit but remained within levels reported by others. A filter pressure drop model was also developed. Results demonstrated the need for a pressure drop model applicable to N95s relative to existing models developed with the use of fibers with larger diameters than those used in current N95 FFRs. A set of N95 FFR characteristics are provided that can be used to develop models of typical N95 FFR filter performance and pressure drop in future studies. [ABSTRACT FROM AUTHOR]

The recent surge of global populism has led many intellectuals to call for new forms of democratic elitism. Yet research into the sources of support for political organizations and regimes predicts that suppressing opportunities for public participation will likely exacerbate antisystem political tendencies. We cite the recent protests in Chile, a nation that has employed democratic elitism more effectively than perhaps any other, as illustrative of the eventual consequences of suppressing voice. Our research indicates that empowering citizens through vibrant parties and continuous democracy is the best way to avoid populist impulses and waves of contentious politics. [ABSTRACT FROM AUTHOR]

This paper introduces a novel algorithm for selecting the optimal wafers for measurement given a set of selection rules. The algorithm is based on assigning a penalty to each of the sampling rules and then using a mixed-integer linear program to pick the wafers which minimize the sum of the penalties. By waiting until the metrology step to determine the best wafers to measure, a real-time decision can be made based on which wafers have previously been measured, the tools and chambers on which wafers were processed, and other user-specified selection criteria. The penalties can also be increased after a rule violation to ensure that each of the selection rules are satisfied at a finite frequency. Index Terms--Adaptive sampling, mixed-integer programming, wafer-level control, wafer sampling.

Run-to-run (RtR) control technology has received tremendous interest in semiconductor manufacturing. Exponentially weighted moving average (EWMA), double-EWMA, and internal model control (IMC) filters are recognized methods for online RtR estimation. In this paper, we consider recursive least squares (RLS) as an alternative for online estimation and RtR control. The relationship between EWMA-type and RLS-type estimates is analyzed and verified with simulations. Because measurement delay is almost inevitable in semiconductor manufacturing, we discuss and compare the performance of EWMA, RtR-IMC, and RLS controllers in handling measurement delay and measurement noise for processes with a deterministic drift. An ad hoc solution is proposed to handle measurement delay for processes with time-varying drifts. The results are illustrated through several simulations and a shallow trench isolation (STI) etch process as an industrial example. Index Terms--Double exponentially weighted moving average (EWMA), EWMA, internal model control (IMC), measurement delay, recursive least squares (RLS), run-to-run (RtR) control, shallow trench isolation (STI).

Many scholars assume that policy performance determines popular support for political systems. Yet in the wake of recent economic crises, patterns of performance and regime support have diverged in many countries, and popular perceptions of performance often fail to reflect the actual quality of governance. To resolve these paradoxes, I draw on recent scholarship on regime support and procedural fairness. I show that strong voice (the ability of citizens to influence political outcomes and a key element of procedural justice in democracies) influences regime support in a way not accounted for in this literature: by moderating the relationship between policy performance and perceptions of performance. These findings show that people will evaluate equivalent outcomes more favorably if they are produced using fair procedures. As performance has long been shown to positively influence support, procedural justice has an additional, indirect influence on people's attitudes toward political systems. [ABSTRACT FROM AUTHOR]

Studies on discrete emotions typically work to evoke one emotion at a time. Yet many political phenomena cause multiple emotions. Threats, for example, cause, anger, and fear, have diametrically opposing behavioral consequences. As a result, the effect of experimental treatments can be masked by the countervailing influence of emotions with similar affect. This issue is exacerbated by existing measures of negative emotions, such as the Positive and Negative Affect Schedule (PANAS). We show that the PANAS is contaminated by systematic measurement error, as negative affect produced by one emotion influences responses on the other. To overcome this, we develop an alternative version of the PANAS that allows respondents to select which emotions they are feeling, then rate the severity. This technique accurately captures respondent's emotional reactions, reducing measurement error and thus decreasing the correlation between fear and anger. The tactics we developed have broad relevance for experimental researchers analyzing emotional responses to politics. [ABSTRACT FROM AUTHOR]

What impact does personalism, or presidential dominance of a weakly organized ruling party, have on the level of democracy? We argue that presidents who dominate their own weakly organized parties are more likely to seek to concentrate power, undermine horizontal accountability, and trample the rule of law than presidents who preside over parties that have an independent leadership and an institutionalized bureaucracy. Independent party leaders, we suggest, will often try to curb the excesses of the president in order to protect their own political prospects. We explore these hypotheses through a quantitative analysis of the determinants of the level of democracy in 18 Latin American countries from 1980–2015. We find that personalism has a consistently negative impact on the level of democracy in Latin America. [ABSTRACT FROM AUTHOR]

A study was conducted to map conformational changes occurring in M.Hhal on binding nonspecific DNA using high-resolution NMR. Findings revealed comparisons with previous NMR studies and pathway to sequence- specific complex formation.

The structural changes that occur when the bacterial DNA cytosine methyltransferase (M.Hhal) binds to its cofactor and the dynamic properties of the protein are described.