objective(s):the present study reports the development and validation of a sensitive and rapid extraction method beside high performance liquid chromatographic method for the determination of crocetin in human serum. materials and methods:the hplc method was carried out by using a c18 reversed-phase column and a mobile phase composed of methanol/water/acetic acid (85:14.5:0.5 v/v/v) at the flow...

introduction the iran has vast areas of karst landforms due to the relatively high carbonaceous rocks deposited during different geologic eras. karst landforms are noteworthy for investigation from many aspects. the primary importance of these regions is the considerable amount of underground water stored in karst formations. these reserves are favorable, both in quality and quantity, as natura...

Convective precipitation-localized, short-lived, intense, and sometimes violent-is at the root of challenges associated with observation, simulation, and prediction of precipitation. The understanding of long-term changes in convective precipitation characteristics and their role in precipitation extremes and intensity over extratropical regions are imperative to future water resource managemen...

Leymus chinensis is a dominant, rhizomatous perennial C3 species in the grasslands of Songnen Plain of Northern China, and its productivity has decreased year by year. To determine how productivity of this species responds to different precipitation regimes, elevated CO2 and their interaction in future, we measured photosynthetic parameters, along with the accumulation and partitioning of bioma...

Abstract Observations of the precipitation rate/depth, drop size distribution, velocity and type are compared from six in situ sensor designs over 12 months to assess their performance provide a benchmark for future design deployment. The considered tipping bucket (TBR), counting (RAL), acoustic (JWD), optical (LPM), single-angle visiometer with capacitor (PWD21), dual-angle (PWS100). Precipita...

[1] Branching valley networks near the landing site of the Huygens probe on Titan imply that fluid has eroded the surface. The fluid was most likely methane, which forms several percent of Titan’s atmosphere and can exist as a liquid at the surface. The morphology of the valley networks and the nature of Titan’s surface environment are inconsistent with a primary valley formation process involv...

For the eventual purpose of developing a generalized method for predicting precipitation from assumed accurate prognoses of the required meteorological element,s, a preliminary investigation is made of the contemporary relntionship between precipitation and the fields of moisture and wind in the atmosphere. Procedures are developed for calculating the rate of precipitation by computing the dive...