The Hertz Corporation

About: The Hertz Corporation is a based out in . It is known for research contribution in the topics: Population & Soil water. The organization has 9562 authors who have published 11044 publications receiving 447929 citations. The organization is also known as: Hertz Rental Car & Hertz Rent-a-Car.

Rupture of rubber. II. The strain concentration at an incision

Abstract: The strain distribution around the tip of an incision in a thin test-piece of highly elastic material is considered. Using the results of a previous paper, relations between this strain distribution and the over-all forces or strains are derived for two particular types of test-piece. Experiments designed to check the theory are described, and agreement is found to be satisfactory. The theory is extended qualitatively to the case where the test-piece is taken to the point of rupture, and experiments are described which confirm the approximate relation derived. The relevance to tearing and to the previously proposed tear criterion is discussed.

The radiation balance of bare soil and vegetation

Abstract: Incoming short-wave radiation S, reflected short-wave radiation α S and net radiation R were measured over bare soil and crops from 1957 to 1959, and net long-wave radiation (L) was deduced from For grass, α increased from 0·23 at solar elevation 60° to 0·28 at 20° with daily mean 0·26. For bare soil, the corresponding increase was from 0·16 to 0·19 with mean 0·17. In mid-June, L for bare soil decreased from – 0·1 cal cm−2 min−1 during the night to – 0·4 cal cm−2 min−1 in the early afternoon. For long grass, in August, the corresponding change was from – 0·05 to – 0·22 cal cm−2 min−1. Under clear skies the incoming long-wave component varied much less than the outgoing component, and net flux L was closely related to surface temperature. With a heating coefficient β = – dL/dR, the observed linear dependence of R on S in the absence of cloud may be expressed as Where, formally, R = L0 when S = 0. For grass, sugar beet and potatoes, β lay between 0·15 and 0·22 with a variation which may depend on wind speed rather than on crop. The value for dry bare soil was higher (0·41) because there was greater surface heating. Measurements under clear skies and over grass at Cambridge and Kew agree well with Rothamsted values (β = 0·22, L0 = – 5·9 cal cm−2 hr−1). Over Nebraska prairie, β = 0·25, L0 = – 4·5 cal cm−2 hr−1 from selected observations during Projects Great Plains and Prairie grass.

Cadmium accumulation in soils from long‐continued applications of superphosphate

Abstract: SUMMARY A simple, sensitive method developed for the analysis of geostandards was used to measure the accumulation of Cd in soils from superphosphate applied annually to grass-land and arable soils for many years. Rates of application were equivalent to 33 kg P and 5 g Cd ha−1 yr−1 for 95 yr in three experiments in England and to 37 kg P and 20 g Cd ha−1 yr −1 for 30 yr in one experiment in New Zealand. Very little Cd accumulated in the surface horizons (0–22.5cm) of either of the arable soils from England; about one-quarter of the applied Cd was detected in the sub-soil (22.5–45.0 cm) of one experiment (Broadbalk) but none in the second (Barnfield). About one-half of the applied Cd was retained in the 0–22.5 cm horizon of grassland soils from both England and New Zealand. The light (<2.2 gcm−3) organic-rich fraction of Park Grass soil from England contained about three times as much Cd as the heavier, mineral-rich fraction. This suggests that when Cd is incorporated into organic matter its mobility is decreased and soil pH then has smaller effects on its mobility. Uptake of Cd by grass-clover pasture in New Zealand averaged only 0.4 g Cd ha−1 yr−1 or 2% of the amount applied.

Structure of Cdc42 bound to the GTPase binding domain of PAK.

Abstract: The Rho family GTPases, Cdc42, Rac and Rho, regulate signal transduction pathways via interactions with downstream effector proteins. We report here the solution structure of Cdc42 bound to the GTPase binding domain of αPAK, an effector of both Cdc42 and Rac. The structure is compared with those of Cdc42 bound to similar fragments of ACK and WASP, two effector proteins that bind only to Cdc42. The N-termini of all three effector fragments bind in an extended conformation to strand β2 of Cdc42, and contact helices α1 and α5. The remaining residues bind to switches I and II of Cdc42, but in a significantly different manner. The structure, together with mutagenesis data, suggests reasons for the specificity of these interactions and provides insight into the mechanism of PAK activation.