This paper describes a modification of a nondestructive ultrasonic method for measurements of the phase velocity of bulk waves in arbitrary directions in generally anisotropic materials. In the conventional method the through-transmission technique is used for velocity measurements at a specified angle of incidence. When this angle is changed by rotation of the sample, the transmitted beam changes position, and so the position of the receiving transducer must be changed. This leads to experimental difficulties and loss of precision. In the double-transmission technique, the ultrasonic wave is reflected from reflector plates behind the sample and returns via the same path to the same position on the transmitter/receiver working in pulse-echo mode, which eliminates the necessity of readjusting the receiver position. It is also shown that for arbitrary direction of measurement in anisotropic materials, time-delay measurements give phase velocity regardless of the angle of deviation between phase and group velocities. The physical basis of this phenomenon is explained. An example of velocity measurement and elastic-constant determination is given for unidirectional graphite–epoxy composite. Stability of the nonlinear least-square algorithm used for reconstruction of the elastic constants from the velocity data is demonstrated by computer simulation on a synthetic set of data.

Iron deficiency and fatigue are common problems in adolescent females. Heavy menstrual bleeding (HMB) is associated with both iron deficiency and fatigue. The aim of this study was to define baseline ferritin values and fatigue symptoms in a population of young females with excessive menstrual blood loss, as compared to healthy controls. The study population included 11 to 17-year-old menstruating females presenting to an Adolescent Gynaecology Clinic, Menorrhagia Clinic or Sports Medicine clinic. To evaluate the degree and effects of menstrual blood loss, we utilized the Ruta Menorrhagia Severity Score. We investigated the symptoms of fatigue using the Fatigue Severity Scale. We evaluated possible predictors of ferritin level (age, body mass index, fatigue scores and Menorrhagia Severity Score) using generalized linear models. A total of 48 adolescents with HMB and 102 healthy adolescents completed the study. Iron deficiency and elevated fatigue scores were common findings in young women with HMB. Both fatigue severity scores and menorrhagia severity scores were significantly higher in young women with HMB as compared to healthy controls. In adolescents with HMB, 87.5% had ferritin levels ≤40 ng mL(-1), and 29.2% had ferritin levels ≤15 ng mL(-1). Our generalized linear models did not identify any significant univariate relationships between ferritin levels and patient age, body mass index, fatigue score or menorrhagia score. Iron deficiency and symptoms of fatigue are common findings in young women with HMB. Fatigue severity scores are significantly higher in young women with HMB as compared to healthy controls.

This paper reports an ultrasonic angle-beam technique for the evaluation of interfacial properties of adhesive joints. The technique is based on measurement of the frequency response of obliquely incident ultrasonic signals from an adherend-adhesive interface. A theoretical model was developed for analysis of the interaction between the obliquely incident ultrasonic waves and multilayered adhesive joints. A special ultrasonic goniometer using only one ultrasonic transducer was built to measure the reflected signals. Samples with controlled interfacial properties were prepared for experimental determination of these properties. The experimental results were in good agreement with those predicted from the model. It was found that some of the minima loci in the reflected frequency spectra are independent of either the thickness or the elastic properties of the interfacial layer. This enables us to develop a simple and stable reconstruction procedure to determine the thickness and interfacial properties from experimental data.

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The cyclic calcium oxide‐calcium carbonate (CaO‐CaCO3) process is a promising option for large‐scale CO2 control. Important advantages include high‐temperature operation, inexpensive sorbent feedstock, and high CO2 capture capacity of CaO. However, decreasing sorbent reactivity over multiple cycles, due to high‐temperature sintering, presents a major challenge for further progress. The Ohio State University (OSU) has led the development of a novel three‐step calcium looping (CaO‐Ca(OH)2‐CaCO3) process for post‐ and precombustion CO2 capture. An overview of OSU's work is provided, highlighting the differences in this approach when compared to competing efforts in this field.