نتایج جستجو برای: caco3

تعداد نتایج: 2615  

2009
H. J. Li

With increasing NO2 concentration in the troposphere, the importance of NO2 reaction with mineral dust in the atmosphere needs to be evaluated. Until now, little is known about the reaction of NO2 with CaCO3. In this study, the heterogeneous reaction of NO2 on the surface of CaCO3 particles was investigated at 296 K and NO2 concentrations between 4.58×1015 molecules cm−3 to 1.68×1016 molecules ...

2010
Deniz Karaca Klaus Wallmann

[1] Five sediment cores from cold seeps at the forearc off Costa Rica were used to explore the relationship between fluid advection, dissolved Ca concentrations in upward migrating fluids, and authigenic CaCO3 precipitation. A numerical transport‐reaction model was used to determine rates of anaerobic oxidation of methane (AOM), CaCO3 precipitation, and benthic fluxes of solutes. Production of ...

2013
Yaran Zhang Ping Ma Yao Wang Juan Du Qi Zhou Zhihong Zhu Xu Yang Junlin Yuan

Recently there has been a wide concern on inorganic nanoparticles as drug delivery carriers. CaCO3 particles have shown promising potential for the development of carriers for drugs, but little research had been performed regarding their safe dosage for maximizing the therapeutic activity without harming biosystems. In this study, we assessed the biological safety of porous spherical CaCO3 micr...

2006
CRISTINA BARRÓN CARLOS M. DUARTE ALBERTO VIEIRA BORGES

We measured monthly dissolved oxygen (DO) changes in situ benthic incubations from March 2001 to October 2002 in a Posidonia oceanica meadow and unvegetated sediments of Magalluf Bay (Mallorca Island, Spain) to determine gross primary production (GPP), community respiration (R), and net community production (NCP). From June 2001 to October 2002, we also measured fluxes of dissolved inorganic ca...

Journal: :Internal medicine 2007
Yasunori Iwata Takashi Wada Hitoshi Yokoyama Tadashi Toyama Shinji Kitajima Toshiya Okumura Akinori Hara Junya Yamahana Izaya Nakaya Motoo Kobayashi Kiyoki Kitagawa Satoshi Kokubo Keiichi Yoshimoto Kazuaki Shimizu Norihiko Sakai Kengo Furuichi Yoshitaka Koshino Shinichi Takeda Kazuya Takasawa Satoshi Ohta Masayoshi Takaeda Chikako Takaeda Shuichi Kaneko

BACKGROUND In hemodialysis patients, adynamic bone disease has been reported to be closely associated with low levels of parathyroid hormone (PTH) due to exposure to high levels of serum calcium following the administration of calcium carbonate (CaCO3) or vitamin D agents. This study was conducted to clarify the therapeutic effect of a non-calcemic phosphate binder, sevelamer hydrochloride (sev...

Polyamide-66(PA66)/CaCO3 micro- and nano-composites were prepared using a polymer solution method at filler loading of 0, 1, 2 and 3 weight percent. Nano-size of CaCO3 was synthesized by micro-emulsion technique. The material was characterized by XRD, SEM, FTIR and UV-VIS techniques. XRD results of composites suggested that CaCO3 particles are found in the amorphous phase of the semi-crystallin...

2014
Olli Vuolteenaho KATJA OHENOJA Jouko Niinimäki

During the past decade submicron and nanoparticles have aroused a wide interest and gained new applications due to their high surface area and strength. Grinding with a wet stirred media mill is usually the last process step before the submicron or nanoparticles are added to an application, and the step where the final particle size distribution is achieved. Since stirred media milling is an en...

2013
Asif Naeem Muhammad Akhtar Waqar Ahmad

In calcareous soils, phosphorus (P) retention and immobilization take place due to precipitation and adsorption. Since soil pH is considered a major soil variable affecting the P sorption, an acidic P fertilizer could result in low P adsorption compared to alkaline one. Therefore, P adsorption from DAP and phosphoric acid (PA) required to produce desired soil solution P concentration was estima...

Journal: :Biomacromolecules 2013
Christos S Karamitros Alexey M Yashchenok Helmuth Möhwald Andre G Skirtach Manfred Konrad

The present study focuses on the formation of microcapsules containing catalytically active L-asparaginase (L-ASNase), a protein drug of high value in antileukemic therapy. We make use of the layer-by-layer (LbL) technique to coat protein-loaded calcium carbonate (CaCO3) particles with two or three poly dextran/poly-L-arginine-based bilayers. To achieve high loading efficiency, the CaCO3 templa...

2009
Halim A. Ergül Sayhan Topcuoğlu

Total mass flux (TMF), total organic matter (TOM), carbonate (CaCO3), lithogenic matter, biogenic silica (BSi), organic carbon (Corg), organic nitrogen (Norg) fluxes and sedimentation rates were determined seasonally using a sediment trap deployed in oxic layer on eastern coast of the Black Sea from July 2002 to October 2003. TOM, CaCO3, Corg and Norg percentages in surface sediment and chlorop...

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