Flow injection determination of readily assimilable nitrogen compounds during vinification

A flow injection method for the determination of readily assimilable nitrogen (r.a.n.), i.e. ammonium and aminated nitrogen, is reported. The difference in pH of the sample in the presence and absence of formaldehyde, which blocks the amino function, provides the value of r.a.n. by monitoring the changes in absorbance of bromothymol blue at 616 nm. The detection and quantification limits are 10 and 11.6 mg l-1, respectively; the reproducibility and repeatability are 3.94 mg l-1 and 1.35 mg l-1, respectively; and the sample throughput is 20 samples h-1. The method has been applied to the analysis of 120 samples of must and wine subjected to biological aging. The proposed method also provides good correlation with the reference method used in routine analysis, and it is faster and gives sufficient precision for wineries requirements

Visual illusions of movement

Visual illusions related to involuntary eye movemen

Antenna pattern shaping, sensing, and steering study Final report

Design of steerable satellite antenna with beam pattern sensing syste

Capturing Hiproofs in HOL Light

Hierarchical proof trees (hiproofs for short) add structure to ordinary proof trees, by allowing portions of trees to be hierarchically nested. The additional structure can be used to abstract away from details, or to label particular portions to explain their purpose. In this paper we present two complementary methods for capturing hiproofs in HOL Light, along with a tool to produce web-based visualisations. The first method uses tactic recording, by modifying tactics to record their arguments and construct a hierarchical tree; this allows a tactic proof script to be modified. The second method uses proof recording, which extends the HOL Light kernel to record hierachical proof trees alongside theorems. This method is less invasive, but requires care to manage the size of the recorded objects. We have implemented both methods, resulting in two systems: Tactician and HipCam

Failure of a Dredged Slope in a Sensitive Clay

During construction of a new wharf facility in Portland, Maine, an underwater slope failed during dredging and subsequent driving of piles through the slope. The construction and failure of the slope are described. The major factors which contributed to the failure were: 1) high sensitivity of the silty clay, 2) placement of riprap on the crest of the slope to 4 to 6 ft above the design elevation, 3) method of dredging which caused high shear stresses and probable disturbed zones near the toe of the slope, 4) dredging slope steeper than design slope, 5) pile driving causing localized disturbed zones with low strength around the piles, and 6) sequence of dredging and pile driving

TASK DECOMPOSITION AND THE HIGH PERFORMANCE JUNIOR TENNIS SERVE

To develop consistency in the toss placement and racket trajectory, coaches often decompose the serve and practise it in separate parts. This study compared the kinematics of the ball toss as part of the discrete serve skill and when the skill was decomposed. A 22 camera VICON MX motion analysis system, operating at 250 Hz, captured racket and ball kinematics of 5 elite junior players hitting flat first serves (FS) directed to the ‘T’ of the deuce service box and a ball toss (BT) drill where players were instructed to perform the decomposed skill as in the FS. Paired t-tests were used to assess within-group differences. Vertical displacement of ball zenith increased significantly (~20cm) during BT. Consistency in select racket and ball kinematics characterised the FS, while this appeared to decrease in BT

‘BEND IT LIKE BECKHAM’: BALL ROTATION IN THE CURVED FOOTBALL KICK

The objectives of this study were to quantify the 3D angular velocity and spin axes of a curved versus straight kick for goal in football. A 12 camera 250 Hz 3D Vicon motion analysis system recorded 4 semi-professional soccer players, as they performed 5 straight (S) and 10 curved (C) kicks. While the velocity of the ball was similar for both kicks (~20 m.s-1), spin rate was significantly different (S=22.6 rad.s-1; C=36.4 rad.s-1). While the level of spin for the straight kick was surprising, the elevation angle of its spin axis was significantly lower in the straight compared with curved kicks (S=30.4°; C=62.6°

Sex-specific fundamental and formant frequency patterns in a cross-sectional study

An extensive developmental acoustic study of the speech patterns of children and adults was reported by Lee and colleagues [Lee et al., J. Acoust. Soc. Am. 105, 1455-1468 (1999)]. This paper presents a reexamination of selected fundamental frequency and formant frequency data presented in their report for 10 monophthongs by investigating sex-specific and developmental patterns using two different approaches. The first of these includes the investigation of age- and sex-specific formant frequency patterns in the monophthongs. The second, the investigation of fundamental frequency and formant frequency data using the critical band rate (bark) scale and a number of acoustic-phonetic dimensions of the monophthongs from an age- and sex-specific perspective. These acoustic-phonetic dimensions include: vowel spaces and distances from speaker centroids; frequency differences between the formant frequencies of males and females; vowel openness/closeness and frontness/backness; the degree of vocal effort; and formant frequency ranges. Both approaches reveal both age- and sex-specific development patterns which also appear to be dependent on whether vowels are peripheral or non-peripheral. The developmental emergence of these sex-specific differences are discussed with reference to anatomical, physiological, sociophonetic and culturally determined factors. Some directions for further investigation into the age-linked sex differences in speech across the lifespan are also proposed

Standardising the clinical assessment of coronal knee laxity

Clinical laxity tests are used for assessing knee ligament injuries and for soft tissue balancing in total knee arthroplasty. This study reports the development and validation of a quantitative technique of assessing collateral knee laxity through accurate measurement of potential variables during routine clinical examination. The hypothesis was that standardisation of a clinical stress test would result in a repeatable range of laxity measurements.Non- invasive infrared tracking technology with kinematic registration of joint centres gave real-time measurement of both coronal and sagittal mechanical tibiofemoral alignment. Knee flexion, moment arm and magnitude of the applied force were all measured and standardised. Three clinicians then performed six knee laxity examinations on a single volunteer using a target moment of 18Nm. Standardised laxity measurements had small standard deviations (within 1.1°) for each clinician and similar mean values between clinicians, with the valgus laxity assessment (mean of 3°) being slightly more consistent than varus (means of 4° or 5°).The manual technique of coronal knee laxity assessment was successfully quantified and standardised, leading to a narrow range of measurements (within the accuracy of the measurement system). Minimising the subjective variables of clinical examination could improve current knowledge of soft tissue knee behaviour