Concentrating photovoltaics offer a way to lower the cost of solar power. However, the existing paradigm based on precise orientation of large-area concentrator modules towards the Sun limits their deployment to large, open land areas. Here, we explore an alternate approach using high-efficiency microcell photovoltaics embedded between a pair of plastic lenslet arrays to demonstrate quasi-stati...

The photocatalytic oxidation of the non-biodegradable p-nitrotoluene-o-sulfonic acid (p-NTS) in homogeneous (photo-Fenton reactions) and heterogeneous (with TiO2) solutions has been studied at a pilot-scale under solar irradiation at the Plataforma Solar de Almeria (PSA). In this study two different reactors were tested: a medium concentrating radiation system (Heliomans, HM) and a non-concentr...

1. In Fundulus heteroclitus the dispersing melanophore nerve fibers have a relatively high threshold for faradic stimulation and a low one for stimulation by cutting. When they are protected from the competing action of the concentrating fibers, they show through the responses of their melanophores well marked antidromic activities which can also be seen to a slight degree even where the concen...

This study utilized rates with hereditary hypothalamic diabetes insipidus (D.I.) in order to explore possible mechanisms which prevent full urinary concentration after acute administration of vasopressin in hypothalamic D.I. and which correct this concentrating defect with prolonged therapy.IT WAS FOUND: (a) that the concentrating defect persisted even when the urinary osmolal excretion of D. I...

Microoxygen polarographic electrodes were constructed and used to measure oxygen tension (P(OO2)) in the eyes of rainbow trout (Salmo gairdneri). The values obtained are compared with arterial blood and environmental water P(OO2) and indicate that there is an oxygen-concentrating mechanism in the eye supplying oxygen to the avascular retina. Anatomically similar retes suggest that the mechanism...

The role of high serum and tissue levels of unconjegated bilirubin in the pathogenesis of the impaired urinary concentrating ability was investigated in homozygous (jj) Gunn rats with the congenital absence of hepatic glucuronyl transferase. Continuous phototherapy with blue fluorescent lights at a wave length of 460 nm or oral cholestyramine feeding or both reduced serum levels of unconjugated...

In aldosterone target tissues, 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2) is coexpressed with mineralocorticoid receptors (MR) and protects the receptor from activation by glucocorticoids. Null mutations in the encoding gene, HSD11B2, cause apparent mineralocorticoid excess, in which hypertension is thought to reflect volume expansion secondary to sodium retention. Hsd11b2(-/-) mice are ...

Although the concentrating process in the renal outer medulla is well understood, the concentrating mechanism in the renal inner medulla remains an enigma. The purposes of this review are fourfold. 1) We summarize a theoretical basis for classifying all possible steady-state inner medullary countercurrent concentrating mechanisms based on mass balance principles. 2) We review the major hypothes...