Truncated vortex generators for part-depth wind-tunnel simulations of the atmospheric boundary layer flow

A modified design of the ‘Counihan’ vortex generator was proposed for purposes of part-depth atmospheric boundary layer (ABL) wind-tunnel simulations. Three redesigned vortex generators were manufactured and their applicability was tested in a boundary layer wind tunnel together with a castellated barrier wall and a fetch of roughness elements. Using this hardware, neutrally stratified ABL developing above rural, suburban and urban terrains was successfully reproduced. A hot-wire anemometry system was applied for measurements of mean velocity and velocity fluctuations. Comparisons of wind-tunnel results with full-scale data and/or with theoretical models are presented, including mean velocity, turbulence intensity, integral length scale of turbulence and power spectral density of velocity fluctuations. The analysis of obtained results indicates the adequacy of redesigned ‘Counihan’ vortex generators for part-depth ABL wind-tunnel simulations, as the obtained wind-tunnel results compare well with the full-scale rural, suburban and urban ABL.     

A molecular switch based on current-driven rotation of an encapsulated cluster within a fullerene cage

By scanning tunneling microscopy imaging and electronic structure theory, we investigate a single-molecule switch based on tunneling electron-driven rotation of a triangular Sc3N cluster within an icosahedral C80 fullerene cage among three pairs of enantiomorphic configurations. Bias-dependent action spectra and modeling implicate the antisymmetric stretch vibration of Sc3N cluster as the gateway for energy transfer from the tunneling electrons into the cluster rotation. Hierarchical switching of conductivity among multiple stationary states while maintaining a constant molecular shape, offers an advantage for the integration of endohedral fullerene-based single-molecule switches into multiple logic state molecular devices.     

Association between Insertion-Deletion Polymorphism of the Angiotensin-Converting Enzyme Gene and Treatment Response to Antipsychotic Medications: A Study of Antipsychotic-Naïve First-Episode Psychosis Patients and Nonadherent Chronic Psychosis Patients

We investigated whether a functional insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) influenced antipsychotic treatment. At baseline, and after 8 weeks of treatment with various antipsychotic medications, we assessed patients’ Positive and Negative Syndrome Scale (PANSS) scores, PANSS factors, and metabolic-syndrome-related parameters (fasting plasma lipid and glucose levels, and body mass index). A total of 186 antipsychotic-naïve first-episode psychosis patients or nonadherent chronic psychosis individuals (99 males and 87 females) were genotyped by polymerase chain reaction analysis. The ACE-I/D polymorphism was significantly associated with changes in PANSS psychopathology only (p < 0.05). Compared to ACE-II homozygous males, ACE-DD homozygous and ACE-ID heterozygous males manifested significantly greater decreases in PANSS positive score, PANSS excitement factor, and PANSS cognitive factor. ACE-DD homozygous females manifested higher decreases in PANSS depression factor compared to ACE-II homozygous and ACE-ID heterozygous females. The polymorphism’s effect size was estimated as moderate to strong, while its contribution to the PANSS psychopathology ranged from ~5.4 to 8.7%, with the lowest contribution observed for PANSS positive score changes and the highest for PANSS depressive factor changes. Our results indicate that ACE-I/D polymorphism had a statistically significant but weak gender-specific impact on psychopathology data, and showed no association between ACE-I/D polymorphism and metabolic-syndrome-related parameters.     

Design of linear phase FIR notch filters

This paper investigates some approaches for designing one-dimensional linear phase finite-duration impulse-responses (FIR) notch filters, which are based on the modification of several established design techniques of linear phase FIR band-selective filters. Based on extensive design examples and theoretical analysis, formulae have been developed for estimating the length of a linear phase FIR notch filter meeting the given specifications. In addition, the design of two-dimensional linear phase FIR notch filters is briefly considered. Illustrative examples are included. This work was supported in part by a University of California MICRO grant with matching supports from Rockwell International and CES Inc.     

Compositional dependence of absorption coefficient and band-gap for Nb2O5-SiO2 mixture thin films

The absorption coefficient of composite films consisting of niobia (Nb₂O₅) and silica (SiO₂) mixtures is studied for photon energies around the band gap. The films were deposited by co-evaporation and their composition was varied by changing the ratio of deposition rates of the two materials. Both, as-deposited and thermally annealed films were characterized by different techniques: the absorption coefficient was determined by spectrophotometric measurements and the structural properties were investigated using infrared spectroscopy, transmission electron microscopy and X-ray diffraction. The correlation between the variations of absorption properties and film composition and structure is established. The absorption coefficients determined experimentally are compared with the results derived from effective medium theories in order to evaluate the suitability of these theories for the studied composites.     

Measurement uncertainty of adaptive Chirp-z transform

In this paper analysis of measurement uncertainty of Adaptive Chirp-z transform (ACT) algorithm for power frequency measurement is presented. ACT is a new algorithm developed for real time monitoring of power frequency. Every element (hardware and software) of measurement chain is contributing to the total measurement uncertainty. The analysis of passive voltage dividers, analog-to-digital converters, numeric algorithms and processors (word length and type of arithmetic) are also presented. Estimated values of each contributing part of measurement chain are calculated to the final expression of measurement uncertainty.     

Antifungal Effect of Allium tuberosum,Cinnamomum cassia,and Pogostemon cablin Essential Oils and Their Components Against Population of Aspergillus Species

Antifungal activity of Allium tuberosum (AT), Cinnamomum cassia (CC), and Pogostemon cablin (Patchouli, P) essential oils against Aspergillus flavus strains 3.2758 and 3.4408 and Aspergillus oryzae was tested at 2 water activity levels (a_w: 0.95 and 0.98). Main components of tested essential oils were: allyl trisulfide 40.05% (AT), cinnamaldehyde 87.23% (CC), and patchouli alcohol 44.52% (P). The minimal inhibitory concentration of the plant essential oils against A. flavus strains 3.2758 and 3.4408 and A. oryzae was 250 ppm (A. tuberosum and C. cassia), whereas Patchouli essential oil inhibited fungi at concentration > 1500 ppm. The essential oils exhibited suppression effect on colony growth at all concentrations (100, 175, and 250 ppm for A. tuberosum; 25, 50, and 75 for C. cassia; 100, 250, and 500 for P. cablin essential oil). Results of the study represent a solution for possible application of essential oil of C. cassia in different food systems due to its strong inhibitory effect against tested Aspergillus species. In real food system (table grapes), C. cassia essential oil exhibited stronger antifungal activity compared to cinnamaldehyde.     

Adaptive Chirp Transform for frequency measurement

In this paper Adaptive Chirp Transform (ACT) algorithm for power frequency measurement is presented. It is adjusted for continuous monitoring of power frequency. Signal is first preprocessed with adaptive filter to minimize the error of non-linear model parameters. The resulting parameters are used to narrow the frequency range for CZT method to be effective. Algorithm code has been analyzed and computation complexity has been significantly decreased. Using this algorithm it is possible to measure frequency transients with sufficient accuracy and low execution time. Algorithm is verified through simulations and real-time data.     

Photooxidation of benzene-structured compounds: influence of substituent type on degradation kinetic and sum water parameters

The combined influence of substituent type and UV/H₂O₂ process parameters on the degradation of four aromatic water pollutants was investigated using modified 3³ full factorial design and response surface methodology. Degradation kinetics was described by the quadratic polynomial model. According to the applied ANOVA, besides pH and [H₂O₂], model terms related with the pollutant structure are found to be significant. Different optimal operating conditions and values of observed degradation rate constants were determined for each of the pollutants indicating that the type of substituent influences the overall process effectiveness over structurally defined degradation pathway. Biodegradability (BOD₅/COD) and toxicity (TU) were evaluated prior to the treatment and at the reference time intervals t_1/2(P), t_3/4(P), t_1/4(OC) and t_1/2(OC) corresponding to the real time required to reduce the concentration of parent pollutant and organic content for 1/2, 3/4, 1/4 and 1/2 of initial amount. The observed differences are correlated to the structural differences of studied aromatics.     

Synergistic effects during co-pyrolysis of biomass and plastic: Gas,tar, soot,char products and thermogravimetric study

Synergistic effects of biomass and plastic co-pyrolysis on gas, tar, soot and char production and pyrolysis kinetics were studied using a fixed-bed reactor and a thermogravimetric analyzer, respectively. These pyrolysis products' yields and compositions were measured during the individual pyrolysis of biomass and plastic at 800–1100 °C, and synergistic effects were explored under non-sooty (900 °C) and sooty (1100 °C) conditions. Results shows that the soot starts to form from tar at 900–1000 °C for both biomass and plastic and that the soot from plastic pyrolysis is of greater yield and size than the biomass pyrolysis. Under non-sooty conditions, the synergistic effect of co-pyrolysis results in higher char yields but lower tar yields, while under sooty conditions co-pyrolysis inhibits the gas and soot formation, resulting in higher tar yields and different soot morphologies. The synergistic effect observed by the thermogravimetric analysis agrees with that in a fixed-bed reactor.