Foot shape and radiographs of free-ranging Nubian giraffe in Uganda

Foot health in zoo giraffe has been a topic of recent research, although little is known about the foot health of free-ranging giraffe. This study describes the foot shape and radiographic pathological changes in 27 young adult Nubian giraffe (Giraffa camelopardalis camelopardalis) from a translocation in Uganda (August 2017). Giraffe feet were observed to have a concave sole, the hoof wall was longest by the toe tip, and the weight-bearing surface of the foot was primarily along the periphery of the foot including hoof wall, parts of the heel, and the edge of the sole. Radiographs showed that pedal osteitis and sesamoid bone cysts were relatively uncommon (3/24 giraffe with osteitis, 1/24 giraffe with sesamoid cysts), and that no giraffe in the study had P3 joint osteoarthritis, P3 rotation, or P3 fractures. Radiographs consistently demonstrated a positive palmar/plantar angle with the sole of the hoof thicker at the heel than by the toe tip, with the non weight-bearing palmar/plantar angle measuring 1.6°- 4.3°. This is the first systematic review of foot shape and radiographs in free-ranging giraffe and demonstrates a low prevalence of foot pathologies. This study suggests qualitative differences in foot shape, foot health, radiographic anatomy, and foot pathologies when comparing free-ranging and zoo giraffe. Further research is needed to identify why these differences occur and whether husbandry modifications could help improve zoo giraffe foot health and prevent associated lameness.

Design and Development of a Novel Ultrasonic Field Wetting Angle Measuring Instrument for Researching the Wetting of the Liquid–Solid Interface

A key technical problem in the preparation of Al-Ti-C grain refiner and other composite materials is the poor wetting of the Al-C interface, which greatly restricts the development of the preparation technology of related composite materials. In view of this scientific challenge, a novel ultrasonic field wetting angle measuring instrument has been designed to research the wetting behavior of the liquid–solid interface and ensure that preparation conditions are optimized. The dimensional parameters of the ultrasonic transducer and the horn in the novel ultrasonic wetting angle measuring instrument have been designed by theoretical calculation, and the modal analysis was performed for the ultrasonic horn using the functions of displacement and time. Modal analysis was utilized to optimize the dimension of the ultrasonic horn, and the natural frequency of the longitudinal vibration of the horn was reduced from 22,130 Hz to 22,013 Hz, resulting in an error rate between the actual value (22,013 Hz) and the design value (20 kHz) of less than 1%. In addition, the influence of different transition arc radiuses on the maximum stress of the optimized ultrasonic horn was analyzed.

A Quick-response and High-precision Dynamic Measuring Method with the Application on Small Angle Measurement

Small angle measuring tools with pendulum mechanical structure has two major challenges. One is that it takes long time to wait for the pendulum structure to completely stop swinging, and the other is that the instrument has poor anti-interference ability. Inspired by the two challenges, this paper proposes a dynamical measuring method to achieve a fast and accurate measurement synchronously. Specially, a damped oscillation modeling of the pendulum with nonlinear least squares fitting is presented to estimate the model parameters which includes the angle of the oblique plane. Besides, it is proved that the minimum sample size required for data fitting is decided by one oscillation period, which guarantees the shortest measuring time within high precision. Moreover, this paper also presents the precision criterion of fitting parameters to judge whether the fitting results meet the requirements. This proposed method is applied to a developed small angle measuring tool. The error of the proposed measurement system is better than 3.25 '' and the uncertainty is 4.8 '' within the measurement angle of 2000 '', and the settling time is 0.45 s. The experimental results confirm that this method can not only greatly shorten the measuring time, but also enhance the anti-interference ability and realize high-precision measurement.

Analysis of Automatically Extracted Hallux Valgus Angles Using Markerless 3D Foot Scans From North America, Europe and Asia

Background The forefoot is the foot most affected part by ill-fitting shoes. Footwear fitting standards have the measurements of length, width and arch length. Toe shape has not yet been used in footwear measurement. This study aims at investigating the variation in toe shape, as measured by the hallux valgus angle. Methods An automatic and reproducible hallux valgus angle measuring method using 3D foot scans with no palpation markers is proposed and applied to about half a million samples collected across North America, Europe and Asia. The measuring method is robust, it can detect the medial contour along the proximal phalanx even in extreme cases. Results The hallux valgus angle has a normal distribution with long tails on both sides in the general population. In the three regions (North America, Europe, Asia), the mean and standard deviation of this angle are 9° ± 6°, 8 ° ± 6°, 12° ± 6° for males and 11 ° ± 7°, 12 ° ± 7°, 16° ± 7° for females. Conclusions The hallux valgus angle has a broad distribution in the general population. Females have larger hallux valgus angle than males, and people from Asia have larger hallux valgus angle than people from North America and Europe.

Optical Theodolite Based Rationality Check of Measurement Data From Pulse Radar

Theodolite and radar are important measurement and control devices in aviation, aerospace and other fields. In order to make sure the tracking measurement and navigation control of aircraft and spacecraft safely, this paper creatively proposes a novel method to check the rationality of the three-dimensional measurement data (distance, azimuth and pitch angle) of the pulse radar by using the two-dimensional measurement data (azimuth and pitch angle) of the optical theodolite. Specifically, three different rationality checking functions are constructed for the three different cases of unreliable ranging channel, unreliable angle measuring channel and unreliable ranging and angle measuring channels, and are used for the rationality checking of radar data in the above three cases respectively. Simulation results show that the correct rate is more than 95% as long as the data measured by optical theodolite are reliable.

Preparation and characterization of tung oil-rosin-based polyester internal sizing agent

A series of tung oil-rosin-based polyester (TRP) used as internal sizing agents were prepared using rosin, tung oil, maleic anhydride, and glycerol. TRP structure and properties were examined using Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). The TRP latexes were subsequently used as internal sizing agents, and the sizing properties were evaluated using a scanning electron microscope (SEM), a video-based dynamic contact angle measuring device and a Cobb absorbency tester. The optimal conditions for preparing the TRP sizing agent were as follows: the hydroxy-carboxyl ratio of the material was 0.25; the maleic anhydride dosage was 20 % of rosin; and the tung oil dosage was 40 % of rosin. Under the best conditions, the sized paper Cobb-60 was 15.6 g / m 2 \text{g}/{\text{m}^{2}} , the tensile index was 45.1 N·m/g, the burst index was 3.1 kPa· m 2 {\text{m}^{2}} /g, and the tear index was 15.6 mN· m 2 {\text{m}^{2}} /g.