Frequency response calibration of recess-mounted pressure transducers

A technique is described for measuring the frequency response of pressure transducers mounted inside a model, where a narrow pipette leads to an orifice at the surface. An acoustic driver is mounted to a small chamber which has an opening at the opposite end with an O-ring seal to place over the orifice. A 3.18 mm (1/8 inch) reference microphone is mounted to one side of the chamber. The acoustic driver receives an input of white noise, and the transducer and reference microphone outputs are compared to obtain the frequency response of the pressure transducer. Selected results are presented in the form of power spectra for both the transducer and the reference, as well as the amplitude variation and phase shift between the two signals as a function of frequency. The effect of pipette length and the use of this technique for identifying both blocked orifices and faulty transducers are described

Improved Aircraft Acoustic Technology and its Effect on Airport Community Noise Impact

No abstract availabl

Evaluation of plant derivatives of Meliaceae family as a source of nitrogen for trees

Soil application of fresh organic matter is a way to increase soil organic matter and provide nutrients to trees. The effect of application of organic matter depends on the interaction among soil, root and microbial biomass. The aim of this research was to evaluate the potential release of N for hybrid GF677 (P. persica x P. dulcis) uptake, of 6 neemcakes available on the Italian market compared with fresh leaves of Melia azedarach, an ornamental tree that grows in the area of investigation. The release of N, and consequently root uptake was related to C:N ratio, the lower the ratio the higher the N concentration in plant tissues and plant growth. Using the 15N isotope technique, we found that up to 30% of the N applied with fresh Melia leaves, was accumulated in the tree, however the mineral N concentration in soil and plant and plant growth was not affected by the application of plant derivatives

Reading derived words by Italian children with and without dyslexia: The effect of root length

Children with dyslexia are extremely slow at reading long words but they are faster with stimuli composed of roots and derivational suffixes (e.g., CASSIERE, \u2018cashier\u2019) than stimuli not decomposable in morphemes (e.g., CAMMELLO, \u2018camel\u2019). The present study assessed whether root length modulates children\u2019s morphological processing. For typically developing readers, root activation was expected to be higher for longer than shorter roots because longer roots are more informative access units than shorter ones. By contrast, readers with dyslexia were not expected to be facilitated by longer roots because these roots might exceed dyslexics\u2019 processing capacities. Two groups of Italian 6th graders, with and without dyslexia, read aloud low-frequency derived words, with familiar roots and suffixes. Word reaction times (RTs) and mispronunciations were recorded. Linear mixed-effects regression analyses on RTs showed the inhibitory effect of word length and the facilitating effect of root frequency for both children with and without dyslexia. Root length predicted RTs of typically developing readers only, with faster RTs for longer roots, over and above the inhibitory effect of word length. Furthermore, typically developing children had faster RTs on words with more frequent suffixes while children with dyslexia were faster when roots had a small family size. Generalized linear regression analyses on accuracy showed facilitating effects of word frequency and suffix frequency, for both groups. The large word length effect on latencies confirmed laborious whole-word processing in children when reading low-frequency derived words. The absence of a word frequency effect along with the facilitating effect of root frequency indicated morphemic processing in all readers. The reversed root length effect in typically developing readers pointed to a stronger activation for longer roots in keeping with the idea that these represent particularly informative units for word decoding. For readers with dyslexia the facilitating effect of root frequency (not modulated by root length) confirmed a pervasive benefit of root activation while the lack of root length modulation indicated that the longest roots were for them too large units to be processed within a single fixation

Scheduling reactivo de procesos make-and-pack operando en modo campaña: enfoque CP novedoso

Se presenta un modelo matemático de Constraint Programming (CP) para resolver el problema de scheduling de corto plazo en plantas industriales de tipo batch, multiproducto, multietapa; las cuales operan con procesos make-andpack. Se trata de un enfoque novedoso, capaz de considerar, entre otros aspectos, la operación en modo campañas y tiempos de changeover dependientes de la secuencia y/o del equipo productivo involucrado. El mismo permitió resolver 20 instancias, de tamaño creciente en cuanto al número de lotes a agendar, correspondiente a un problema ampliamente abordado en la bibliografía (proceso de producción de helados). Los resultados obtenidos indican un buen desempeño (veloz y eficaz). Asimismo, se trata de una formulación cuyo tamaño no se incrementa exponencialmente con el crecimiento en el número de lotes considerados.Sociedad Argentina de Informática e Investigación Operativ