نتایج جستجو برای: carbonate sand

تعداد نتایج: 52870  

ژورنال: کواترنری ایران 2019
Ghorbani Nasrabadi, Reza, Kehl, Martin, Khormal, Farhad, Sohrabi, Mohammad, Solymanzadeh, Mohsen,

  Introduction: Biological soil crusts are a community of cyanobacteria, fungi, lichens, and mosses and play key roles in arid and semi-arid regions including carbon and nitrogen accumulation, soil fertility, dust capture, soil conservation and stability. Recent studies show that the formation of biological soil crusts on mobile dunes areas is extremely difficult due to low vegetation cover, st...

2015
Nicole Bauer Petra J. Panak

The complexation of Cm(III) with transferrin is investigated in the pH range from 3.5 to 11.0 in the absence of carbonate and at c(carbonate)tot = 25 mM. In the absence of carbonate two Cm(III) transferrin species I and II are formed depending on pH. An increase of the total carbonate concentration favors the formation of the Cm(III) transferrin species II with Cm(III) bound at the Fe(III) bind...

2008
David A. Hodell Jason H. Curtis

9 We report oxygen and carbon isotope results of bulk and detrital carbonate grains 10 from the last glaciation at IODP Site U1308 (re-occupation of DSDP Site 609). Oxygen 11 isotopic values of individual detrital carbonate grains from Heinrich events average 12 -5.4‰±1.3‰, presumably reflecting values of limestone and dolomite derived from 13 lower Paleozoic basins in northern Canada and north...

2004
Aaron C. Hirsch Larry E. Davis

A gravel pit in south central Stearns County, Minnesota exposes sand and gravel of the Merden Lake esker which is thought to have been deposited by a subglacial stream associated with the Wisconsinan-aged Superior Lobe of the Laurentide ice sheet. An analysis of these sediments was conducted from samples collected through a vertical trench on an east-facing exposure of the gravel pit. A total o...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه هرمزگان - دانشکده علوم پایه 1391

. مطالعات میکروسکوپی برروی سازند بهرام منجر به شناسایی 5 کمربند رخساره ای ساحلی (shore)، پهنه ی جزر و مدی (tidal flat)، لاگون (lagoon)، سد (shoal) و رخساره ی دریای باز (open marine) شده است. بررسی ویژگی های رخساره ها و ریز رخساره های سازند بهرام و تغییرات آنها در جهت جانبی و قائم نشان می دهد که این سازند در یک محیط دریایی کم عمق فلات قاره مختلط تخریبی – کربناته (mixed carbonate – calstic shelf)...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه خلیج فارس - دانشکده مهندسی 1393

in civil engineering concrete is a material combined of hydraulic cement, sand, gravel and water. gravel and sand compose 60 to 70 percent of concrete. these aggregates support compression force of concrete. cement paste acts as glue to stick grain together. in bushehr factories producing aggregates do not operate according to astm standards, so that fineness modulus (fm) of the produced sands ...

Journal: :Materiale Plastice 2022

Resin Concrete uses polymeric resin to replace cement concrete. Four types of polyester resins were identified with Methyl methacrylate as catalyst, calcium carbonate and fly ash fillers along river sand coarse aggregate size 10mm, 6mm used produce Seventy-two trial batches carried out for preliminary investigation targeting compressive strength more than 80 MPa (11.6 ksi) four shortlisted. The...

Journal: :IOP conference series 2023

Abstract Bio-cementation through bacterial mineralization can be considered an “eco-friendly” solution for soft or loose sandy soils, particularly in ground slopes and high rainfall zones, to achieve sustainable development goals. Using urelytical bacteria with the ability decompose urea calcium carbonate precipitation selected as primary agent bio-cementation process. This study clarifies effe...

Journal: :Journal of dairy science 2008
M Norring E Manninen A M de Passillé J Rushen L Munksgaard H Saloniemi

This experiment compared the effects of sand and straw bedding in free stalls on resting time, cleanliness, hock injuries, and hoof health of dairy cows and tested whether cow preferences for a bedding material depended on the familiarity with the material. A total of 52 dairy cows were kept either on straw bedded concrete stalls or sand stalls for at least 21 wk. The lying behavior was observe...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید