沈降定数

WordNet

steadfast in purpose or devotion or affection; "a man constant in adherence to his ideals"; "a constant lover"; "constant as the northern star"
a number representing a quantity assumed to have a fixed value in a specified mathematical context; "the velocity of light is a constant"
a quantity that does not vary (同)constant quantity, invariable

PrepTutorEJDIC

『不変の』,一定の / 『絶え間のない』,不断の,繰り返される / 《文》〈人が〉心変わりしない;(…に対して)誠実な,貞節な《+『to』+『名』》 / (数学で)常数;(化学・物理分析などにおける)定量
沈殿,堆積;沈殿(堆積)作用

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1. 腎疾患における赤血球沈降速度 erythrocyte sedimentation rate in renal disease
2. 小児における末梢のリンパ節腫脹：評価および診断的アプローチ peripheral lymphadenopathy in children evaluation and diagnostic approach
3. 成人における多関節痛の評価 evaluation of the adult with polyarticular pain
4. 急性期反応物質 acute phase reactants
5. 関節リウマチの診断および評価における生物学的マーカー biologic markers in the diagnosis and assessment of rheumatoid arthritis

English Journal

Polyethylene passive samplers to determine sediment-pore water distribution coefficients of persistent organic pollutants in five heavily contaminated dredged sediments.

Charrasse B1, Tixier C2, Hennebert P1, Doumenq P3.Author information 1Institut National de l'EnviRonnement Industriel et des RiSques (INERIS), ARDEVIE, Domaine du Petit Arbois, BP 33, 13545 Aix-en-Provence Cedex 04, France.2Ifremer, RBE-BE-LBCO, rue de l'Ile d'Yeu, 44311 Nantes Cedex 3, France.3Aix Marseille Université, CNRS, Laboratoire de Chimie de l'Environnement, FRE 3416, UMR CNRS 6263, Europôle de l'Arbois, Bâtiment Villemin BP 80, 13545 Aix-en-Provence Cedex 4, France. Electronic address: Pierre.doumenq@univ-amu.fr.AbstractPore concentration and partition coefficients of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were determined in sediments from five distinct contaminated sites in France (marine harbour, rivers canals and highway sedimentation tank). The assessment of the risk caused by such micropollutants requires, in most cases, the measurement of their availability. To assess this availability, low density polyethylene (LDPE) membrane samplers were exposed to these sediments under constant and low-level agitation over a period of 46days. Freely dissolved pore water contaminant concentrations were estimated from the concentration at equilibrium in the LDPE membrane. The depletion of contaminants in the sediments was monitored by the use of performance reference compounds (PRCs). Marked differences in freely dissolved PAH and PCB concentrations and resulting sediment-pore water partition coefficients between these five sediments were observed. Data set was tested onto different empirical and mechanistic models. As final findings, triple domain sorption (a total organic carbon, black carbon and oil phase model) could model PCB data successfully whereas the best fitting for PAH partitioning was obtained by Raoult's Law model.
The Science of the total environment.Sci Total Environ.2014 Feb 15;472:1172-8. doi: 10.1016/j.scitotenv.2013.10.125. Epub 2013 Dec 20.
Pore concentration and partition coefficients of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were determined in sediments from five distinct contaminated sites in France (marine harbour, rivers canals and highway sedimentation tank). The assessment of the risk caused
PMID 24360917

Polycyclic aromatic hydrocarbons (PAHs) in sediments from lake Lille Lungegårdsvannet in Bergen, western Norway; appraising pollution sources from the urban history.

Andersson M1, Klug M2, Eggen OA2, Ottesen RT2.Author information 1Geological Survey of Norway (NGU), Postboks 6315 Sluppen, 7491 Trondheim, Norway. Electronic address: malin.andersson@ngu.no.2Geological Survey of Norway (NGU), Postboks 6315 Sluppen, 7491 Trondheim, Norway.AbstractThis study aims to determine the temporal character and concentration variability of polycyclic aromatic hydrocarbon (PAH) during the last 5,400 years in urban lake sediments through a combination of dating and chemo-stratigraphical correlation. We investigate the chemical history of the city of Bergen and determine the effect of specific point sources, as well as diffuse sources, and also help assess the risk of remediation plans. By using several organic compounds, metals and cyanide, we demonstrate the more accurate timing of sedimentation. The PAH results display very low concentrations in pre-industrial times, followed by a general increase that is punctuated by a few significant concentration increases. These most probably correspond to urban fires, domestic heating, gaswork activity and most recently due to traffic pollution. At the same depth as a significant rise in concentration from background levels occurred, the high relative occurrence of low-molecular-weight PAH-compounds, such as naphthalene, were replaced by heavier compounds, thus indicating a permanent change in source. The general observation, using ratios, is that the sources have shifted from pre-industrial pure wood and coal combustion towards mixed and petrogenic sources in more recent times. The (14)C dating provides evidence that the sedimentation rate stayed more-or-less constant for 4,500 years (from 7200 to 2700 calibrated years before present (calyr BP)), before isostatic uplift isolated the water body and the sedimentation rate decreased or sediments were eroded. The sediment input increased again when habitation and industrial activities encroached on the lake. The (14)C dating does not provide consistent data in that period, possibly due to the fact that the lake has been used as a waste site throughout the history of Bergen city. Therefore, results from (14)C dating from anthropogenically influenced sediments should be used with caution.
The Science of the total environment.Sci Total Environ.2014 Feb 1;470-471:1160-72. doi: 10.1016/j.scitotenv.2013.10.086. Epub 2013 Nov 16.
This study aims to determine the temporal character and concentration variability of polycyclic aromatic hydrocarbon (PAH) during the last 5,400 years in urban lake sediments through a combination of dating and chemo-stratigraphical correlation. We investigate the chemical history of the city of Ber
PMID 24246939

Effect of humic acid source on humic acid adsorption onto titanium dioxide nanoparticles.

Erhayem M1, Sohn M2.Author information 1Department of Chemistry, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901 USA.2Department of Chemistry, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901 USA. Electronic address: msohn@fit.edu.AbstractIn many studies, different humic acid (HA) sources are used interchangeably to evaluate the effect of organic matter on geochemical processes in the environment. This research looks more specifically at the effect of HA source on HA adsorption onto nano-TiO2 and how HA adsorption affects the fate and transport of nano-TiO2. In this study, six humic acids (HAs) were studied which were derived from soils (SLHA), or from sediments (SDHA) all originating from the state of Florida. Humic acid adsorption onto titanium dioxide nanoparticles (nano-TiO2) and the sedimentation of HA-coated and uncoated nano-TiO2 were monitored by Ultraviolet-visible (UV-vis) spectroscopy. Synchronous scan fluorescence (SSF) spectroscopy was used to complement the study of HA adsorption onto nano-TiO2. Phosphate buffer was found to reduce the amount of HA adsorbed onto nano-TiO2 relative to solutions of NaCl of the same pH and ionic strength. Adsorption constant values (Kads) for HAs varied in the order SLHA>FSDHA (freshwater sedimentary HA)>ESDHA (estuarine sedimentary HA). SSF results suggested that the more highly conjugated fractions of HA, which are more prevalent in SLHAs versus SDHAs, were preferentially adsorbed. In order to better understand the relationship between adsorption and aggregation, sedimentation studies were conducted and it was found that the percentage of nano-TiO2 sedimentation was preferentially enhanced in the order of the presence of SLHA>FSDHA>ESDHA. The extent of nano-TiO2 sedimentation was decreased with increasing HA concentration. TEM imaging of nano-TiO2 confirmed that nano-TiO2 was aggregated in the presence of HAs. The findings in this study suggest that HAs from different sources influence the fate and transport of nano-TiO2 in the environment differently.
The Science of the total environment.Sci Total Environ.2014 Feb 1;470-471:92-8. doi: 10.1016/j.scitotenv.2013.09.063. Epub 2013 Oct 16.
In many studies, different humic acid (HA) sources are used interchangeably to evaluate the effect of organic matter on geochemical processes in the environment. This research looks more specifically at the effect of HA source on HA adsorption onto nano-TiO2 and how HA adsorption affects the fate an
PMID 24140685

Japanese Journal

Direct observation on the Brownian coagulation of PSL particles through optical microscope in the regime near critical coagulation concentration (CCC)

Fukasawa Tomonori,Adachi Yasuhisa,足立泰久
Journal of colloid and interface science 344(2), 343-347, 2010-04-00
… The density of the solvent was controlled by using deuterium oxide (D2O) to avoid sedimentation. … (iii) The rate of coagulation was constant until later stage. …
NAID 120002104425

地球深部探査船「ちきゅう」の下北半島沖慣熟航海コア試料 : 物性変動から予測される古環境変動

青池寛,西弘嗣,坂本竜彦,飯島耕一,土屋正史,平朝彦,倉本真一,眞砂英樹,下北コア微化石研究グループ,相田吉昭,秋元和實,堂満華子,林広樹,長谷川四郎,北里洋,池原実,岩井雅夫,丸山俊明,尾田太良,岡田尚武,大井剛志,大金薫,佐藤時幸,酒井豊三郎,鈴木紀毅,谷村好洋,高嶋礼詩,内田淳一,山崎誠
化石 (87), 65-81, 2010-03-31
… The sedimentation rate is high and nearly constant of 62cm/kyr at Hole C9001C and is low of about 17cm/kyr at Hole C9001D. … These clays suggest a cyclic sedimentation controlled by the Milankovitch cycles. …
NAID 110007593296