The dual-frequency scatterometer reexamined

The utility of dual frequency scatterometers in measuring ocean wave directional spectra can be increased by adding third frequency to the system. The background which effectively limits signal detectability in dual frequency operation can be made a part of the signal through the addition of this third frequency. Signal detectability is limited only by system thermal noise and space based operation becomes more feasible

Tri-county pilot study

The author has identified the following significant results. An area inventory was performed for three southeast Texas counties (Montgomery, Walker, and San Jacinto) totaling 0.65 million hectares. The inventory was performed using a two level hierarchy. Level 1 was divided into forestland, rangeland, and other land. Forestland was separated into Level 2 categories: pine, hardwood, and mixed; rangeland was not separated further. Results consisted of area statistics for each county and for the entire study site for pine, hardwood, mixed, rangeland, and other land. Color coded county classification maps were produced for the May data set, and procedures were developed and tested

Germination and storage of apple seeds

Apple seeds will not germinate immediately after the fruit has become mature enough for picking. It is necessary for the seed to pass thru a stage of after-ripening. The freshly extracted apple seed contains about 85 percent moisture. At room temperature approximately one-half of the moisture is lost during the first five days. Soaking the seed prior to planting does not increase germination. Ninety-one percent of apple seeds prevented from drying out when they were extracted from the fruit germinated. The best temperature for storage was found to be a temperature between 10 and 30 C. Seeds which had air dried germinated poorly in all cases. Apple seeds which had been air dried and kept for a year did not germinate. Apple seeds may be planted any time after Nov. 1. Where seeds are to be shipped long distances, special precaution must be made to keep the seeds from deteriorating. The seed coat is not a factor in causing delayed germination

A ZnO/SiO2/Si(100) Love mode transducer

ZnO/SiO2/Si[100] Love mode transducers were fabricated. SiO2 films were deposited using electron beam evaporation. ZnO films were deposited using r.f. magnetron sputtering. ZnO and SiO2 films were examined by SEM and the performance of the transducers was examined by their acoustic response. The observation of the SAW Love mode delay line was performed under untuned conditions. Operating frequencies of the transducers were around 85 MHz

Previous attentional set can induce an attentional blink with task-irrelevant initial targets

Identification of a second target is often impaired by the requirement to process a prior target in a rapid serial visual presentation (RSVP). This is termed the attentional blink. Even when the first target is task-irrelevant an attentional blink may occur providing this first target shares similar features with the second target (contingent capture). An RSVP experiment was undertaken to assess whether this first target can still cause an attentional blink when it did not require a response and did not share any features with the following target. The results revealed that such task-irrelevant targets can induce an attentional blink providing that they were task-relevant on a previous block of trials. This suggests that irrelevant focal stimuli can distract attention on the basis of a previous attentional set

The Relationship between Upper Arm Anthropometrical Measures and Vertical Jump Displacement

The purpose of this study was to determine if upper body segment length or mass contributes to vertical jump (VJ) displacement. Seventeen men (n=9) and women (n=8) who were active recreationally participated in this investigation. Subjects performed VJ for maximal displacement, and skeletal length measurements of the humerus (acromion following the lateral lip to the greater tuberosity), ulna (olecranon to the ulnar styloid process), and hand (lunate to distal end of third phalanx) were obtained by palpation of boney landmarks and a standard tape measure. Pearson Product Moment Correlation Coefficients were used to compare the data with statistical significance accepted at the p=0.05 level. Length of the ulna was the only upper body limb measurement that was significantly correlated with the vertical jump (P = 0.04). As the regression equation to predict VJ from ulnar length was not significant, it appears that neither intrinsic upper arm skeletal length nor arm segment mass is a strong predictor of VJ displacement

X-ray Observations of Gravitationally Lensed Quasars; Evidence for a Hidden Quasar Population

The large magnification factors of gravitationally lensed (GL) systems allow us to investigate the properties of quasars with X-ray luminosities that are substantially lower than those of unlensed ones and also provide an independent means of estimating the contribution of faint quasars to the hard X-ray component of the cosmic X-ray background. Our spectral analysis indicate a flattening of the spectral index in the hard band (4-20keV restframe) for 2 radio-loud quasars in the GL quasar sample for which the data have moderate signal-to-noise ratio. We have identified a large fraction of Broad Absorption Line (BAL) quasars amongst the GL quasar population. We find that approximately 35% of radio-quiet GL quasars contain BAL features which is significantly larger than the 10% fraction of BAL quasars presently found in optically selected flux limited quasar samples. We present a simple model that estimates the effects of attenuation and lens magnification on the luminosity function of quasars and that explains the observed fraction of GL BAL quasars. These observations suggest that a large fraction of BAL quasars are missed from flux limited optical surveys. Modeling of several X-ray observations of the GL BAL quasar PG1115+080 suggests that the observed large X-ray variability may be caused in part by a variable intrinsic absorber consistent with previously observed variability of the BAL troughs in the UV band. The observed large X-ray flux variations in PG1115+080 offer the prospect of considerably reducing errors in determining the time delay with future X-ray monitoring of this system and hence constraining the Hubble constant H$_{0}$.Comment: 19 pages, 10 figures, 9 Tables, accepted for publication in Ap

Addemdum to: ''The Mathematical Structure of Quantum Superspace as a Consequence of Time Asymmetry''

In this paper we improve the results of sec. VI of paper [M. Castagnino, Phys. Rev. D 57, 750 (1998)] by considering that the main source of entropy production are the photospheres of the stars

Effects of flame retardance additives on the mechanical and fire performance of natural fibre composites

The incorporation of sustainability is becoming increasingly important in manufacturing practices worldwide. This includes the development of natural fibre composites with mechanical and flammability characteristics suitable for structural interiors. Composites manufactured from kenaf fibres and polypropylene (PP) were investigated as to their suitability as materials for the interiors of buildings, aircraft and such-like. Natural fibres like kenaf act as fuel sources during combustion, and hence, flame retardants are added to the mix. In the present study, the ammonium polyphosphate (APP)-based flame retardant Budit® 3167 was used to address this issue. Limited studies exist on how the inclusion of APP influences the composites’ mechanical properties. Hence the main objective of this research project was to evaluate the effect of adding Budit 3167 on both mechanical and flammability properties of kenaf-PP composites. Kenaf-PP composites were manufactured with various fibre weight percentages, with and without Budit 3167. The composites were subjected to different experiments to assess their mechanical and flammability behaviour. It was found that Budit 3167 not only improved the flammability properties of the composites, but also the tensile and flexural moduli due to the flame retardant behaving like a particle reinforcement. However, weak interfacial bonds arising from the addition of Budit 3167 led to a decrease in mechanical strength, providing a basis for further investigation. It was concluded that kenafPP composites with Budit 3167 show good potential as a sustainable alternative for structural interiors