A NEW LOOK AT THE OPTIMUM DIMENSIONS OF CONVECTIVE SPINES

The optimum dimensions of spines of various profiles are reexamined by taking into account the profile curvature effects. Simple working formulas for the optimum dimensions are proposed. When the ratio of spine width to length, δ₀/b₀, is set equal to zero, the present results are reduced to the earlier findings which are obtained on the basis of employing the length-of-arc assumption.     

Imaging techniques for observing laminar geometry in the feather shaft cortex

By being at the interface of the exocytic and endocytic pathways, the plant trans-Golgi network (TGN) is a multitasking and highly diversified organelle. Despite governing vital cellular processes, the TGN remains one of the most uncharacterized organelle of plant cells. In this review, we highlight recent studies that have contributed new insights and to the generation of markers needed to answer several important questions on the plant TGN. Several drugs specifically affecting proteins critical for the TGN functions have been extremely useful for the identification of mutants of the TGN in the pursuit to understand how the morphology and the function of this organelle are controlled. In addition to these chemical tools, we review emerging microscopy techniques that help visualize the TGN at an unpreceded resolution and appreciate the heterogeneity and dynamics of this organelle in plant cells.     

Integrating Communication and Engineering Education: A Look at Curricula,Courses, and Support Systems

In this article we point to the ways in which engineering and communication disciplines can work together to ensure the ABET criterion that encompasses effective communication is represented in engineering curricula. Drawing upon examples from several universities in North America, we offer useful portraits of writing across the curriculum approaches, interdisciplinary courses, integrated programs, and a variety of support systems including writing and communication centers and online resources. As we develop increased awareness of the importance of including communication instruction in engineering curricula, the variety of possibilities presented in this article can help us integrate communication and engineering education.     

Dielectric Properties of Potatoes and Potato Chips

SUMMARY— Dielectric properties (dielectric constant, ɛ'_r; loss tangent, tans; and dielectric loss factor, ɛ"_r) were determined for raw potatoes and for potato chips, using the precision slotted line technique. Measurements on raw potatoes were made at 77°F (25°C) and at frequencies of 300, 1,000, and 3,000 MHz (megahertz). Measurements on potato chips were made at three moisture levels; at 77°F (25°C), 125°F (51.6°C), and 180°F (82.2°0; and at frequencies of 300, 1,000, and 3,000 MHz. Moisture, total lipids, and nitrogen contents are reported for both the raw potatoes and the potato chips.
As would be expected from their high moisture content and the presence of various dissolved salts, the raw potatoes possess extremely high dielectric values.
Potato chips show a rapidly decreasing dielectric loss as moisture content is reduced; the loss values of the chips approach those of the oil used for frying them after moisture has been reduced to approximately 3% and the oil content has been increased accordingly.
For finish drying of potato chips, a frequency of 3,000 MHz will result in 3–4.5 times greater power production in the chips than will the use of a frequency of 1,000 MHz (in the moisture and temperature range at which the data were obtained). However, this difference in power production is due almost entirely to the difference in frequency since the difference in dielectric loss values at the two frequencies is quite small.