A bipolar output voltage pulse transformer boost converter with charge pump assisted shunt regulator for thermoelectric energy harvesting

This system presents an energy harvesting system that generates bipolar output voltage (±1 V) based on a miniature 1:1 turn-ratio pulse transformer boost converter using sub-threshold level input voltage source. A shunt regulator is designed using six-transistor Schmitt-Trigger core to limit the boost converter output voltage. Another power stage, i.e. a fully integrated on-chip single-stage cross-coupled charge pump, then generates 3 V output from the unused extra output power of boost converter, which is shunted otherwise. The increased voltage headroom generated is instrumental for sensor, analog and RF circuits. Charge pump clock frequency is designed to adaptively tracking the input voltage, which is sensed using power-saving time-domain digital technique. Based on a standard CMOS 0.13-µm technology, chip measurement verified the operations of the boost converter, shunt regulator and bipolar charge pump prototypes, respectively. Simulations confirmed the full system operations. During start-up, the system only requires minimum start-up input voltage of 36 mV at input power of 5.8 µW.     

Modified Goodness-of-Fit Tests for Gamma Distributions with Unknown Location and Scale Parameters

The common Kolmogorov-Smirnov, Anderson-Darling, and Cramer-von Mises goodness-of-fit tests require continuous underlying distributions with known parameters. This paper gives tables of critical values for these tests for gamma distributions with unknown location and scale parameters and known shape parameters. The powers of these tests are given for a number of alternative distributions. A relation between the critical values and the inverse square of the shape parameter is presented. For larger sample sizes, the modified CvM test is usually the most powerful of the three tests. One exception is for the alternative of a lognormal distribution where the modified AD test is most powerful. The equation, C = ao + a1(1/?2) describes the relation between critical value and shape parameter quite well.     

Characterization of Flow in Intravenous Catheters

The pressure-flow (P-F) relationship in intravenous catheters is shown to be represented by the predictive model P = RLF + RTF2. The pressure loss due to F, calculated from experimental data, was found to equal the expected Poiseuille laminar flow loss. Pressure loss due to F2 was found to be the sum of turbulent P losses due to entrance length flow disturbance, kinetic energy at the outflow, and minor shape change losses. Analysis of the flow capabilities of intravenous catheters can be used to evaluate suitability for specific intravenous infusion needs.     

Highly Tunable Thiol-Ene Photoresins for Volumetric Additive Manufacturing

Volumetric additive manufacturing (VAM) forms complete 3D objects in a single photocuring operation without layering defects, enabling 3D printed polymer parts with mechanical properties similar to their bulk material counterparts. This study presents the first report of VAM-printed thiol-ene resins. With well-ordered molecular networks, thiol-ene chemistry accesses polymer materials with a wide range of mechanical properties, moving VAM beyond the limitations of commonly used acrylate formulations. Since free-radical thiol-ene polymerization is not inhibited by oxygen, the nonlinear threshold response required in VAM is introduced by incorporating 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) as a radical scavenger. Tuning of the reaction kinetics is accomplished by balancing inhibitor and initiator content. Coupling this with quantitative measurements of the absorbed volumetric optical dose allows control of polymer conversion and gelation during printing. Importantly, this work thereby establishes the first comprehensive framework for spatial–temporal control over volumetric energy distribution, demonstrating structures 3D printed in thiol-ene resin by means of tomographic volumetric VAM. Mechanical characterization of this thiol-ene system, with varied ratios of isocyanurate and triethylene glycol monomers, reveals highly tunable mechanical response far more versatile than identical acrylate-based resins. This broadens the range of materials and properties available for VAM, taking another step toward high-performance printed polymers.     

Overall gloss evaluation in the presence of multiple cues to surface glossiness

Human observers use the information offered by various visual cues when evaluating the glossiness of a surface. Several studies have demonstrated the effect of each single cue to glossiness, but little has been reported on how multiple cues are integrated for the perception of surface gloss. This paper reports on a psychophysical study with real stimuli that are different regarding multiple visual gloss criteria. Four samples were presented to 15 observers under different conditions of illumination in a light booth, resulting in a series of 16 stimuli. Through pairwise comparisons, an overall gloss scale was derived, from which it could be concluded that both differences in the distinctness of the reflected image and differences in luminance affect gloss perception. However, an investigation of the observers' strategy to evaluate gloss indicated a dichotomy among observers. One group of observers used the distinctness-of-image as a principal cue to glossiness, while the second group evaluated gloss primarily from differences in luminance of both the specular highlight and the diffuse background. It could therefore be questioned whether surface gloss can be characterized with one single quantity, or that a set of quantities is necessary to describe the gloss differences between objects.     

高效液相色谱法测定母乳及牛乳中总核苷酸含量

建立高效液相色谱测定母乳和牛乳中总核苷酸含量和组成的分析方法。总核苷酸包括游离核苷酸、游离核苷、核苷聚合物及加合物等不同来源的可利用核苷总量。利用酶解法释放出母乳中的核苷,以硼化聚丙烯酰胺凝胶（Affi-Gel 601）作为固相萃取介质进行样品净化,用反相高效液相色谱仪检测,内标法定量,检测结果以核苷酸计。且针对母乳样品的特性,增加高温灭活步骤进行样品前处理,以检测母乳中核苷酸的天然含量及组成。对所建方法进行全面验证,结果表明其具有良好的线性,相关系数（r2）均在0.999以上;母乳中各核苷酸的检出限和定量限分别在0.18～0.45 mg/L和0.60～1.51 mg/L之间;母乳基质中3 种不同加标水平下总核苷酸的回收率均在99%～108%之间,连续3 d 6 次检测结果的相对标准偏差在0.8%～7.8%之间,显示了良好的准确性及精密度。然后进一步利用所建检测方法,评估母乳及5 种市面常见的牛乳中的核苷酸总量及组成用以验证该方法的适用性。该方法的灵敏度、准确性及精密度均可满足对母乳和牛乳样品中天然的核苷酸含量及组成的测定要求。本研究为今后大样本量调查母乳及牛乳样品中核苷酸的含量和组成提供了更加科学准确的方法。     

Characterising the release of flavour compounds from chewing gum through HS-SPME analysis and mathematical modelling

The headspace solid-phase microextraction (HS-SPME) technique combined with GC–MS was evaluated to study 33 selected flavour compounds released from chewing gum. The operating conditions of SPME were optimised, including different fibres (PDMS, DVB/CAR/PDMS, PA and PDMS/DVB), sample size, extraction time and temperature. The results indicated that while HS-SPME was a rapid and valuable technique, poor reproducibility occurred under all conditions. It was found that this deficiency could be alleviated by utilising mathematical modelling techniques, an approach which had not been previously used in the analysis of flavour compounds in chewing gum by HS-SPME. Compared to the instrumental analysis data themselves, the models provided more insights to the release behaviour of flavour compounds from chewing gum and the more reproducible kinetic rate constants might be used for comparing the release of different compounds or the same compound under different conditions.     

Relationship of senescence of corn (Zea mays L.) stalk pith, cob parenchyma and first developed leaf tissues to RNA content and synthesis

In stalk parenchyma tissue of WF9 X 38-11 single corn (Zea mays L.), there was a per cell increase in RNA synthesis and a slight increase in total RNA as cells became older. In cob parenchyma tissue of WF9 X 38-11 single cross corn, both total RNA content and RNA synthesis per cell decreased with the age of cells. In first developed leaf tissue of FR43 X FR14A single cross corn, RNA synthesis increased steadily but only slightly over its life span. The pattern of RNA synthesis and destruction in senescing leaf tissue of seedlings and two sources of parenchyma tissue of maturing plants appeared to differ.     

Cognitive controls and psychopathology.

Studied 90 psychiatric inpatients (nonpsychotic, nonschizophrenic psychotic, schizophrenic) and 35 normal controls to (a) determine whether some of the traditional cognitive controls could be isolated in these patients and (b) evaluate whether various diagnostic groups differed from each other and from normals in terms of these congitive controls. Ss were administered a battery of cognitive control tasks (e.g., the Phillips Scale of Premorbid Adjustment, WAIS, and Rorschach tests). With age, socioeconomic status, and verbal IQ as covariates, the factor structure for the total group was similar to that reported in other studies of cognitive control organization in the normal population. Schizophrenic and other psychiatric patients were not characterized by distinctly different organizations of cognitive controls. Although patients showed specific areas of cognitive dysfunctions, these seemed to be related to degree of disorganization. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Scotopic Sensitivity in Coyotes (Canis latrans)": Erratum.

Reports an error in the original article by Steven W. Horn and Philip N. Lehner (Journal of Comparative and Physiological Psychology, 1975[Nov], Vol 89[6], pp. 1070-1076). The corrected sentence beginning in the first line on page 1074 is published here. (The following abstract of this article originally appeared in record 2005-09231-001). Measured the absolute scotopic limen for light intensity for 3 10-mo-old female coyotes. The methodology was similar to that used by D. S. Blough (see record 1959-07701-001) in determining psychological thresholds in pigeons. Ss were operantly conditioned to depress 1 of 2 foot treadles, left or right, depending on the condition of the stimulus light. Scotopic adaptation curves for each S were generated. Nonlinear aggression curves were then fitted to the raw data. The mean scotopic thresholds did not differ significantly. However, time to the curves' asymptotes did differ significantly for 1 S. The adaptation curves showed a distinct rod-cone "break," and retinal histology confirmed that the coyote has a duplex retina with a preponderance of rods. In addition, electroretinographic analysis showed the relative contributions of rods and cones at various light intensities and indicated a rod-cone break at approximately 15 min. Scotopic spectral sensitivity curves were also generated. Ss' scotopic visual threshold was exceeded by the natural illumination available under many nocturnal conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)