Cracking pressure control of parylene checkvalve using slanted tensile tethers

MEMS check valves with fixed cracking pressures are important in micro-fluidic applications where the pressure, flow directions and flow rates all need to be carefully controlled. This work presents a new surface-micromachined parylene check valve that uses residual thermal stress in the parylene to control its cracking pressure. The new check valve uses slanted tethers to allow the parylene tensile stress to apply a net downward force on the valving seat against the orifice. The angle of the slanted tethers is made using a gray-scale mask to create a sloped sacrificial photoresist with the following tether parylene deposition. The resulted check valves have both the cracking pressures and flow profiles agreeable well with our theoretical analysis

Parylene stiction

This paper presents a preliminary study into stiction between parylene C and substrate surfaces for biocompatible check-valve applications. During fabrication, parylene C is used as the structural material for the check-valve. The substrate surfaces studied include Au, Al, Si, parylene C, XeF_2 treated Si, and silicon dioxide. Stiction between different surfaces is created after sacrificial photoresist etching. Then, the stiction is measured using blister tests, and stiction mechanisms for different materials are investigated. The devices are released with different recipes to examine their effects. Finally, the results of the study reveal methods to control the cracking pressure of parylene check-valves

Neutron Density Distributions of Neutron-Rich Nuclei Studied with the Isobaric Yield Ratio Difference

The isobaric yield ratio difference (IBD) between two reactions of similar experimental setups is found to be sensitive to nuclear density differences between projectiles. In this article, the IBD probe is used to study the density variation in neutron-rich $^{48}$Ca. By adjusting diffuseness in the neutron density distribution, three different neutron density distributions of $^{48}$Ca are obtained. The yields of fragments in the 80$A$ MeV $^{40, 48}$Ca + $^{12}$C reactions are calculated by using a modified statistical abrasion-ablation model. It is found that the IBD results obtained from the prefragments are sensitive to the density distribution of the projectile, while the IBD results from the final fragments are less sensitive to the density distribution of the projectile.Comment: 3 figure

Conflict management and task reflexivity for team in-role and extra-role performance in China

The ability to reflect upon and manage their internal functioning may very much help teams contribute to their organizations. This study suggests that managing conflict cooperatively and productively provides a foundation for effective team task reflexivity. 200 employees in 100 work teams in China completed measures of their team\u27s cooperative, competitive, and avoiding approach conflict management and task reflexivity and 100 managers indicated the team\u27s in-role and extra-role (organizational citizenship behavior) performance. Results support the theorizing that conflict management can contribute to team task reflexivity. Structural equation analysis suggested that cooperative conflict management promotes task reflexivity that in turn results in team performance. These results, coupled with previous research, were interpreted as suggesting that cooperative approaches to conflict and task reflexivity are complementary foundations for effective teamwork

Monotherapy of acetylsalicylic acid or warfarin for prevention of ischemic stroke in low-risk atrial fibrillation: A Easter Asian population-based study

Background: This study aimed to investigate the effectiveness of monotherapy acetylsalicylic acid(ASA) and warfarin for stroke prevention in low-risk atrial fibrillation (AF) by using a population--based cohort study in Taiwan.Methods: A newly diagnosed low-risk AF patient cohort were identified by using National HealthInsurance Research Database (NHIRD) in Taiwan in 2008. The study cohort was observed witha follow-up of 2 years to examine the onset of ischemic stroke (IS) (to 2010). The longitudinal data wereanalyzed by using generalized estimation equations (GEE).Results: A total of 8,065 newly-diagnosed low-risk AF patients were identified in 2008. 7.4% wereprescribed with ASA and 4.6% were prescribed with warfarin. The GEE results showed that low-riskAF patients with hypertension who received warfarin were associated with a statistically significant58.4% reduction of IS risk (OR = 0.416, p = 0.024, 95% CI 0.194–0.891). Additionally, low-risk AFpatients with hyperlipidemia who received warfarin were associated with a 69.3% reduction of IS risk(OR = 0.307, p = 0.044, 95% CI 0.097–0.969).Conclusions: Warfarin is suggested to be prescribed in preventing IS for low-stroke-risk AF patientswith hypertension and hyperlipidemia

Choosing the pp in LpL_p loss: rate adaptivity on the symmetric location problem

Given univariate random variables $Y_1, \ldots, Y_n$ with the $\text{Uniform}(\theta_0 - 1, \theta_0 + 1)$ distribution, the sample midrange $\frac{Y_{(n)}+Y_{(1)}}{2}$ is the MLE for $\theta_0$ and estimates $\theta_0$ with error of order $1/n$, which is much smaller compared with the $1/\sqrt{n}$ error rate of the usual sample mean estimator. However, the sample midrange performs poorly when the data has say the Gaussian $N(\theta_0, 1)$ distribution, with an error rate of $1/\sqrt{\log n}$. In this paper, we propose an estimator of the location $\theta_0$ with a rate of convergence that can, in many settings, adapt to the underlying distribution which we assume to be symmetric around $\theta_0$ but is otherwise unknown. When the underlying distribution is compactly supported, we show that our estimator attains a rate of convergence of $n^{-\frac{1}{\alpha}}$ up to polylog factors, where the rate parameter $\alpha$ can take on any value in $(0, 2]$ and depends on the moments of the underlying distribution. Our estimator is formed by the $\ell^\gamma$-center of the data, for a $\gamma\geq2$ chosen in a data-driven way -- by minimizing a criterion motivated by the asymptotic variance. Our approach can be directly applied to the regression setting where $\theta_0$ is a function of observed features and motivates the use of $\ell^\gamma$ loss function for $\gamma > 2$ in certain settings.Comment: 60 pages; 7 figure

Poly[bis­(μ4-benzene-1,4-dicarboxyl­ato)(μ4-succinato)diterbium(III)]

In the title compound, [Tb2(C4H4O4)(C8H4O4)2]n, the coord­in­ation around each Tb atom is distorted square-anti­prismatic. The benzene-1,4-dicarboxyl­ate and succinate anions bridge the anti­prisms, forming a three-dimensional network. The succinate anion is located on a centre of inversion. The structure is isomorphous with the Dy, Gd, Er and Nd complexes