Home slaughtering and processing of beef (1989)

A beef animal selected for slaughter should be healthy and in thrifty condition. Keep the animal off feed 24 hours before slaughter, but provide free access to water. Don't run or excite the animal prior to slaughter because this may cause poor bleeding and give the carcass a bloody appearance. The weather, especially expected temperatures the few days following slaughter, is extremely important. Night temperatures should be 32 degrees F or lower for the carcass to chill properly without refrigeration. The meat will spoil if improperly chilled and stored during warm weather. Also, during extremely cold weather, the meat should be protected from freezing by covering it with a clean cover.Reprinted 11/89/5M

Home slaughtering and processing of beef (1993)

This article cites the proper method and precautions for slaughtering beef cattle at home

Femtosecond laser fabricated nitinol living hinges for millimeter-sized robots

Nitinol is a smart material that can be used as an actuator, a sensor, or a structural element, and has the potential to significantly enhance the capabilities of microrobots. Femtosecond laser technology can be used to process nitinol while avoiding heat-affected zones (HAZ), thus retaining superelastic properties. In this work, we manufacture living hinges of arbitrary cross-sections from nitinol using a femtosecond laser micromachining process. We first determined the laser cutting parameters, 4.1 Jcm^-2 fluence with 5 passes for 5 um ablation, by varying laser power level and number of passes. Next, we modeled the hinges using an analytical model as well as creating an Abaqus finite element method, and showed the accuracy of the models by comparing them to the torque produced by eight different hinges, four with a rectangular cross-section and four with an arc cross-section. Finally, we manufactured three prototype miniature devices to illustrate the usefulness of these nitinol hinges: a sample spherical 5-bar mechanism, a sarrus linkage, and a piezoelectric actuated robotic wing mechanism.Comment: 6 pages, 6 figures, submitted to IEEE RA-

Home slaughtering and processing of beef

Harold B. Hedrick and William C. Stringer (Department of Food Science and Nutrition), Maurice Alexander (Department of Animal Science, College of Agriculture)Revised 3/82/8

The running kinematics of free-roaming giraffes, measured using a low cost unmanned aerial vehicle (UAV)

The study of animal locomotion can be logistically challenging, especially in the case of large or unhandleable animals in uncontrolled environments. Here we demonstrate the utility of a low cost unmanned aerial vehicle (UAV) in measuring two-dimensional running kinematics from free-roaming giraffes (Giraffa camelopardalis giraffa) in the Free State Province, South Africa. We collected 120 Hz video of running giraffes, and calibrated each video frame using metatarsal length as a constant object of scale. We tested a number of methods to measure metatarsal length. The method with the least variation used close range photography and a trigonometric equation to spatially calibrate the still image, and derive metatarsal length. In the absence of this option, a spatially calibrated surface model of the study terrain was used to estimate topographical dimensions in video footage of interest. Data for the terrain models were collected using the same equipment, during the same study period. We subsequently validated the accuracy of the UAV method by comparing similar speed measurements of a human subject running on a treadmill, with treadmill speed. At 8 m focal distance we observed an error of 8% between the two measures of speed. This error was greater at a shorter focal distance, and when the subject was not in the central field of view. We recommend that future users maximise the camera focal distance, and keep the subject in the central field of view. The studied giraffes used a grounded rotary gallop with a speed range of 3.4–6.9 ms−1 (never cantering, trotting or pacing), and lower duty factors when compared with other cursorial quadrupeds. As this pattern might result in adverse increases in peak vertical limb forces with speed, it was notable to find that contralateral limbs became more in-phase with speed. Considering the latter pattern and the modest maximal speed of giraffes, we speculate that tissue safety factors are maintained within tolerable bounds this way. Furthermore, the angular kinematics of the neck were frequently isolated from the pitching of the body during running; this may be a result of the large mass of the head and neck. Further field experiments and biomechanical models are needed to robustly test these speculations

Room temperature synthesis of non-isocyanate polyurethanes (NIPUs) using highly reactive N-substituted 8-membered cyclic carbonates

There is a growing interest to develop green synthetic pathways towards industrially relevant polymers such as polyurethanes without the use of toxic and dangerous isocyanate monomers. The most promising route towards non-isocyanate polyurethanes (NIPUs) is the aminolysis of dicyclic carbonates derived from renewable resources. Although, cyclic carbonates of 5- and 6-members have been successfully proposed, aminolysis of these compounds requires the use of high temperatures to obtain high conversions and subsequently high molecular weight NIPUs. Indeed, these cyclic carbonates do not allow the achievement of high molecular weight NIPUs using low reactive diamines analogous to two of the most industrially relevant aliphatic diisocyanates. Herein, we report a (bis) N-substituted 8-membered cyclic carbonate that could be prepared from naturally abundant epoxides, diamines and dimethyl carbonate using sustainable chemical routes. This N-substituted 8 membered cyclic carbonate appeared to be much more reactive than the smaller 5- and 6-membered cyclic carbonates. Due to this increased reactivity, we obtained high molecular weight NIPUs using a variety of diamines, including industrially relevant hindered aliphatic diamines, such as 5-amino-1,3,3-trimethylcyclohexanemethylamine (IPDA) and 4,4’-methylenebis(cyclohexylamine). The synthesis of NIPUs was demonstrated at room temperature without the need for any additional catalyst. Altogether, this paper shows that (bis) N-substituted 8-membered cyclic carbonates are ideal starting materials for the synthesis of sustainable non-isocyanate polyurethanes (NIPUs).he authors would like to thank the European Commission for its financial support through the projects Renaissance-ITN 289347, OrgBIO-ITN 607896 and SUSPOL-EJD 642671. Haritz Sardon gratefully acknowledges financial support from MINECO through project SUSPOL and FDI 16507. Yi Yan Yang gratefully acknowledges financial support from Institute of Bioengineering and Nanotechnology (Biomedical Research Council, Agency for Science, Technology and Research, Singapore). We are also thankful for the technical and human support provided by IZO-SGI SGIker of UPV-EHU and European funding (ERDF and ESF)

How male sound pressure level influences phonotaxis in virgin female Jamaican field crickets (Gryllus assimilis)

Understanding female mate preference is important for determining the strength and direction of sexual trait evolution. The sound pressure level (SPL) acoustic signalers use is often an important predictor of mating success because higher sound pressure levels are detectable at greater distances. If females are more attracted to signals produced at higher sound pressure levels, then the potential fitness impacts of signalling at higher sound pressure levels should be elevated beyond what would be expected from detection distance alone. Here we manipulated the sound pressure level of cricket mate attraction signals to determine how female phonotaxis was influenced. We examined female phonotaxis using two common experimental methods: spherical treadmills and open arenas. Both methods showed similar results, with females exhibiting greatest phonotaxis towards loud sound pressure levels relative to the standard signal (69 vs. 60 dB SPL) but showing reduced phonotaxis towards very loud sound pressure level signals relative to the standard (77 vs. 60 dB SPL). Reduced female phonotaxis towards supernormal stimuli may signify an acoustic startle response, an absence of other required sensory cues, or perceived increases in predation risk

The locomotor kinematics and ground reaction forces of walking giraffes.

Giraffes (Giraffa camelopardalis Linnaeus 1758) possess specialised anatomy. Their disproportionately elongate limbs and neck confer recognised feeding advantages, but little is known about how their morphology affects locomotor function. In this study, we examined the stride parameters and ground reaction forces from three adult giraffes in a zoological park, across a range of walking speeds. The patterns of GRFs during walking indicate that giraffes, similar to other mammalian quadrupeds, maintain a forelimb-biased weight distribution. The angular excursion of the neck has functional links with locomotor dynamics in giraffes, and was exaggerated at faster speeds. The horizontal accelerations of the neck and trunk were out of phase, compared with the vertical accelerations which were intermediate between in and out of phase. Despite possessing specialised morphology, giraffes’ stride parameters were broadly predicted from dynamic similarity, facilitating the use of other quadrupedal locomotion models to generate testable hypotheses in giraffes

Three-dimensional simulation for fast forward flight of a calliope hummingbird

We present a computational study of flapping-wing aerodynamics of a calliope hummingbird (Selasphorus calliope) during fast forward flight. Three-dimensional wing kinematics were incorporated into the model by extracting time-dependent wing position from high-speed videos of the bird flying in a wind tunnel at 8.3 m s−1. The advance ratio, i.e. the ratio between flight speed and average wingtip speed, is around one. An immersed-boundary method was used to simulate flow around the wings and bird body. The result shows that both downstroke and upstroke in a wingbeat cycle produce significant thrust for the bird to overcome drag on the body, and such thrust production comes at price of negative lift induced during upstroke. This feature might be shared with bats, while being distinct from insects and other birds, including closely related swifts