INTRODUCTION The origin of the humic acid fraction of soils is still unclear in spite of extensive investigations accomplished over the last years (ref. 1). Different origins have been proposed, based on the most recent theory or on the applica­ tion of the latest analytical method. Thus, it has been proposed that soil humic acids are derived from lignins, microbial activity and synthesis of me...

This review on self-assembly in biological fi brous composites presents theory and simulation to elucidate the principles and mechanisms that govern the thermodynamics, material science, and rheology of biological anisotropic soft matter that are involved in the growth/self-assembly/material processing of these materials. Plant cell wall, a multi-layered biological fi brous composite, is presen...

Periderm is a tissue of secondary origin that replaces damaged epidermis. It can be found in underground plant organs, as an above-ground tissue of woody species (cork), and as a wound-healing tissue. Its outer layers are composed of phellem cells with suberized walls that constitute a protective barrier, preventing pathogen invasion and fluid loss. In potato, a model for periderm studies, peri...

TIGHTLY COUPLED MITOCHONDRIA HAVE BEEN PREPARED FROM A VARIETY OF PLANT SOURCES: white potato (Solanum tuberosum), Jerusalem artichoke (Heliantus tuberosus), cauliflower buds (Brassica oleracea), and mung bean hypocotyls (Phaseolus aureus). Mitochondria with no appreciable coupling were also prepared from skunk cabbage spadices (Symplocarpus foetidus).Room temperature difference spectra show th...

Supervisory control deals with automated synthesis of controllers based on models of the uncontrolled system and the control requirements. In this paper we share the lessons learned from synthesizing controllers for a patient support system of an MRI scanner regarding the specification of the control requirements. We learned that strictly following the philosophy of supervisory control, which p...

Corrosion-fatigue, a cracking mechanism in fossil-fueled generating plants, predominately occurs in the water walls and economizers of sub-critical plants. Cracking attributed to corrosion-fatigue has occurred in water wall tubing of both membrane and tangential designs. The occurrence (particularly in membrane water wall tubing) presents a challenge for nondestructive evaluation (NDE) because ...

In plants, efficient immune responses against microbial infection depend on the ability to rapidly couple pathogen recognition to downstream signaling responses. In this context, plant immunity requires highly dynamic responses that involve multiple organelles during the recognition and signaling events associated with defense. Nuclear dynamics play a critical role in plant immunity based on th...

The development of empirical classification models for fault diagnosis usually requires a process of training based on a set of examples. In practice, data collected during plant operation contain signals measured in faulty conditions, but they are ‘unlabeled’, i.e., the indication of the type of fault is usually not available. Then, the objective of the present work is to develop a methodology...