7,843 research outputs found
Reflectance spectra of Fe(2+)-Mg(2+) disordered pyroxenes: Implications to remote-sensed spectra of planetary surfaces
The reflectance spectra of Fe(2+)-Mg(2+) disordered orthopyroxenes are relevant to surfaces of terrestrial planets onto which basaltic magma has been extruded. If cooling rates of basalt lava flows were fast, equilibrium iron intersite partitioning may not have been achieved so that abnormal enrichments of Fe(2+) ions in M1 sites would occur. The two intense pyroxene Fe(2+) site CF bands in the 1 micron and 2 micron regions would continue to dominate the the reflectance spectra so that the pyroxene composition and structure type would be readily identified in telescopic spectral profiles. However, abnormal intensification of the Fe(2+)/M1 site CF band at 1.20 microns could lead to the false identification of olivine in remote sensed spectra because in pyroxene-olivine mixtures the inflection around 1.20 microns is the only spectral feature for detecting the presence of olivine. The identification of iron-bearing plagioclase feldspars, too, would be obscured by the pyroxene Fe(2+)/M1 site CF band at 1.20 microns. Such interference would be a major problem if in situ reflectance spectra could be measured on the surface of Venus where ambient temperatures are as high as 475 C. Disordering of Fe(2+) and Mg(2+) ions comparable to that in the orthopyroxenes used in this spectral chemical study might be expected in low Ca pyroxenes occurring on the Venusian surface. Researchers conclude that Fe(2+)/M1 site spectral features need to be carefully assessed in remote-sensed spectra before deductions are made about the presence of olivine on planetary surfaces
Jonathan Besancon in a Sophomore Piano Recital
This is the program for the sophomore piano recital of Jonathan Besancon. The recital took place on February 13, 1981, in the Mabee Fine Arts Center Recital Hall
Technologies and multi-barrier systems for sustainable groundwater recharge and irrigation
Managed aquifer recharge (MAR) consists of artificially replenishing
groundwater to facilitate reuse and/or the associated environmental benefits.
Meanwhile, soil aquifer treatment (SAT) is a process of geo-purification
designed and operated to improve the quality of the infiltrating water and is thus
a type of MAR. SAT consists of a basin operating under rotation of drying and
wetting periods. Often, SAT involves water of impaired quality applied onto soil
and consequently it implies various risks of health, geochemical and physical
nature with difficult or irreversible remediation.
To study the effect of pre-treatment on SAT a pilot plant including conventional
activated sludge (CAS), a membrane bioreactor (MBR), tertiary and secondary
vertical flow reed beds (VFRB) and SAT soil columns. The sludge retention time
(SRT) in the CAS and MBR processes was changed every 6 months to look at
the impact of SRT on SAT. Each unit and treatment train effluent was
characterised to determine the impact of effluent quality on SAT performance.
This study showed that tertiary VFRB, especially when fed with MBR effluent,
was the best option for SAT and irrigation reuse as it provided the best
compliance with reuse standards and the best fertilisation potential. However,
long-term clogging occurred in SAT after tertiary VFRB, suggesting the need for
a longer resting period or shorter wetting period.
This study also highlighted the importance of total suspended solids (TSS)
content for SAT removal mechanisms and infiltration rate. In particular, SAT fed
with high TSS content effluent was susceptible to temperature variation. Hence
the duration of wetting and flooding periods should be adapted according to the
season. Further, variation in SRT only indirectly affected pollutants removal by
the system including CAS treatment set up at 6 d SRT where the N compounds
balance was favourable to an autotrophic N removal
MEASURING CAPACITY AND WILLINGNESS FOR POVERTY REDUCTION IN FRAGILE STATES
Food Security and Poverty,
Sales: Retail Dealer\u27s Liability for Injury Arising from Consumption of Adulterated Canned Food
Sales: Retail Dealer\u27s Liability for Injury Arising from Consumption of Adulterated Canned Foo
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