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1.
ISA Trans ; 116: 167-181, 2021 Oct.
Article in English | MEDLINE | ID: mdl-33546862

ABSTRACT

This work suggested a novel method in order to solve uncertain problem with uncertainty on pool market tariff with respect to wind and photovoltaic generations as well as storage units. Aiming this regard, information gap decision theory method is applied for solving the considered problem. This way, 3 major models are considered into account for big industrial consumers including: risk-taker, risk-averse, and risk-neutral models. Efficiency of suggested methods are studied by exertion of proposed method on big consumer risk via various pool yield tariffs. In addition, appraised obtained results prove the efficiency of demand response program for decreasing the over expenditure of big consumer. Therefore, good impacts of demand response program caused decrease in big user expenditure.

2.
Astrobiology ; 21(4): 381-393, 2021 04.
Article in English | MEDLINE | ID: mdl-33351679

ABSTRACT

The martian surface has been continuously exposed to galactic cosmic radiation. Since organic compounds are degraded by ionizing radiation, knowledge of their decay constants is fundamental to predicting their stability on the martian surface. In this study, we report the radiolysis constant for the destruction of soil organic compounds at a starting concentration of ∼2011 µg C/gsoil from the Mojave Desert. The soils were exposed to gamma irradiation with absorbed doses of up to 19 MGy at room temperature, representing ∼250 million years of exposure to galactic cosmic rays. The destruction of total soil organic carbon and the formation of gases were investigated by a sequential on-line analytical array coupled to gas chromatography-mass spectrometry. Soil inorganic and organic carbon were degraded exponentially with a radiolysis constant 0.3 MGy-1(30%) producing mostly carbon dioxide (93.2%), carbon monoxide (6.2%), and methane (0.6%). Using the dose rate measured by the Radiation Assessment Detector on board the Curiosity rover, we make predictions on the survival of organic compounds in the cold martian subsurface. It is estimated that soil organic compounds with initial concentrations as those found today at the Mojave Desert would have been destroyed to levels <1 ppb at 0.1 m in depth in ∼2000 Myr. Pristine organic compounds are expected to be present at a depth of ∼1.5 m. These results are relevant for the search of organic compounds in past, present, and future missions to Mars. In particular, we predict that the upcoming ExoMars will encounter pristine organic compounds at this depth.


Subject(s)
Cosmic Radiation , Mars , Carbon , Extraterrestrial Environment , Gamma Rays , Methane , Soil
3.
Sci Rep ; 7(1): 6368, 2017 07 25.
Article in English | MEDLINE | ID: mdl-28743873

ABSTRACT

The paleoclimate during the Early Eocene in Maritime Antarctica is characterized by cool conditions without a pronounced dry season. Soils formed on volcanic material under such climate conditions in modern analogue environments are usually Andosols rich in nanocrystalline minerals without pedogenic smectite. The paleosols formed on volcanic material on King Georges Island are covered by basalts, dated by 6 new 40Ar/39Ar datings to 51-48 Ma, and are rich in smectite. A pedogenic origin of the smectites would suggest a semi-arid rather than a wet non-seasonal humid paleoclimate. To investigate the origin of the smectites in these paleosols we used X-ray diffraction and microscopic techniques. Minor mineralogical changes between the volcanic parent material and the paleosols and a homogenous distribution of smectites throughout the paleosol horizons indicate that these smectites were mainly inherited from the pyroclastic parent material, which was altered prior to surficial weathering. Nevertheless, the mineralogical properties, such as degree of crystallinity and octahedral site occupancy, of these smectites were modified during the ancient soil formation. Our findings highlight that trioctahedral smectites were a product of deuteric alteration of pyroclastic rocks and were progressively transformed to dioctahedral smectites during weathering in a soil environment on King George Island.

4.
Anal Chem ; 82(5): 2161-3, 2010 Mar 01.
Article in English | MEDLINE | ID: mdl-20136093

ABSTRACT

In this Technical Note, the quantitative turbidimetric assay for determination of the bacteriolytic activity of enzymes with gram-negative bacteria is proposed. The reactivity of hen white-egg lysozyme toward gram-negative E. coli intact cells was studied. It was found that the highest lysis rate occurred at pH 8.9 in the system containing 0.03 M NaCl. The mechanism of the reaction is discussed and applied for the quantitative evaluation of the reaction rate. The proposed method enables fast, reliable, and reproducible analysis of bacteriolytic activity of lysozyme with gram-negative bacteria.


Subject(s)
Escherichia coli/metabolism , Muramidase/metabolism , Nephelometry and Turbidimetry/methods , Hydrogen-Ion Concentration , Reproducibility of Results
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