scholarly journals SUSPENDED SEDIMENT IN A TIDAL ESTUARY

1966 ◽  
Vol 1 (10) ◽  
pp. 39 ◽  
Author(s):  
A.R. Halliwell ◽  
B.A. O'Connor

A brief description is given of vork being carried out in the Mersey- Estuary, England. This work is part of a sedimentation study of the area, and has necessitated many days' field observations at stations distributed along and across the Estuary. Attention is drawn to the factors influencing the sediment movement and the variables, such as velocity, suspended solids, salinity and temperature that must be measured in order to define the sedimentation complex adequately. A study is made of the effect of variations in temperature and tidal range upon the mean concantration of suspended solids observed at stations in the Estuary; the relationship proposed is of the form

2001 ◽  
Vol 5 (1) ◽  
pp. 103-118 ◽  
Author(s):  
J. A. Cole ◽  
K. Whitelaw

Abstract. Surveys of the Mersey estuary in north-west England were undertaken near the mouth of the estuary in the region known as the Mersey Narrows. Tidal fluxes of suspended and dissolved matter, particularly heavy metals, through the Mersey Narrows were investigated. This paper gives results of conducting four intensive cross-sectional surveys of the Narrows, during which currents, salinities, turbidity and water samples were obtained systematically at numerous positions, throughout selected tidal cycles. Over 300 water samples per survey were analysed to yield suspended and dissolved concentrations of the elements As, Cd, Cr, Cu, Hg, Ni, Pb and Zn, at all states of the tide. Suspended solids, concentrations and salinities were also measured. Suspended particulates account for the majority of each element present, except for cadmium, which was present in roughly equal dissolved and suspended fractions. From the tidal current and water quality data, calculations were made of hour-by-hour fluxes of each component, to show the detailed ebb and flow of heavy metals and the net tidal transport of each component. Although some differences between landward transport on the flood tide and seaward transport on the ebb were not significant, the more definite results consistently showed a seawards net transport. For spring tides of high tidal range, there was an indication of an opposite tendency, reducing the seawards transport or even reversing it, for certain suspended components. Keywords: Mersey estuary, surveys, tidal flux, dissolved metals, particulate metals, salinity, suspended particulate matter, suspended solids


1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.


Author(s):  
Shivananda B Nayak ◽  
Dharindra Sawh ◽  
Brandon Scott ◽  
Vestra Sears ◽  
Kareshma Seebalack ◽  
...  

Purpose: i) To determine the relationship between the cardiac biomarkers ST2 and NT-proBNP with ejection fraction (EF) in heart failure (HF) patients. ii) Assess whether a superiority existed between the aforementioned cardiac markers in diagnosing the HF with reduced EF. iii) Determine the efficacy of both biomarkers in predicting a 30-day cardiovascular event and rehospitalization in patients with HF with reduced EF iv) To assess the influence of age, gender, BMI, anaemia and renal failure on the ST2 and NT-proBNP levels. Design and Methods: A prospective double-blind study was conducted to obtain data from a sample of 64 cardiology patients. A blood sample was collected to test for ST2 and NT-proBNP. An echocardiogram (to obtain EF value), electrocardiogram and questionnaire were also obtained. Results: Of the 64 patients enrolled, 59.4% of the population had an EF less than 40%. At the end of the 30- day period, 7 patients were warded, 37 were not warded, one died and 17 were non respondent. Both biomarkers were efficacious at diagnosing HF with a reduced EF. However, neither of them were efficacious in predicting 30-day rehospitalization. The mean NT-proBNP values being: not rehospitalized (2114.7486) and 30 day rehospitalization (1008.42860) and the mean ST2 values being: not rehospitalized (336.1975), and 30-day rehospitalization. (281.9657). Conclusion: Neither ST2 or NT-proBNP was efficacious in predicting the short- term prognosis in HF with reduced EF. Both however were successful at confirming the diagnosis of HF in HF patients with reduced EF.


2020 ◽  
Vol 3 (1) ◽  

The aim of this study is to investigate the relationship between extrinsic and intrinsic reward on retention among Gen Y employees in Malaysian manufacturing companies. The data was collected from 113 respondents worked in manufacturing companies located in Seri Kembangan, Selangor using questionnaires. Multiple regression analysis was conducted to test the hypotheses. The results showed both extrinsic and intrinsic reward are the factors influencing retaining Gen Y in manufacturing companies. The discussion on the analysis, limitation of the study, recommendation for future research and conclusion were discussed at the end of this study. In a nutshell, it was proven extrinsic reward and intrinsic reward has contributed to the retention of Gen Y employees.


1986 ◽  
Vol 21 (3) ◽  
pp. 332-343 ◽  
Author(s):  
C.H. Chan ◽  
Y.L. Lau ◽  
B.G. Oliver

Abstract The concentration distribution of hexachlorobutadiene (HCBD), pentachloro-benzene (QCB), hexachlorobenzene (HCB) and octachlorostyrene (OCS) in water samples from transects across the upper and lower St. Clair River and the upper Detroit River were determined on four occasions in 1985. The data show a plume of these contaminants from the Sarnia industrial area. The fluxes and concentration profiles of the contaminants at Port Lambton have been modelled success fully using a simple transverse mixing model. A study on the chemical partitioning between the “dissolved” and “suspended sediment” phases shows that an important contaminant fraction is carried in the river by the suspended solids, particularly for lipophilie compounds such as HCB and OCS,


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Satoru Kanda ◽  
Takumi Hara ◽  
Ryosuke Fujino ◽  
Keiko Azuma ◽  
Hirotsugu Soga ◽  
...  

AbstractThis study aimed to investigate the relationship between autofluorescence (AF) signal measured with ultra-wide field imaging and visual functions in patients with cone-rod dystrophy (CORD). A retrospective chart review was performed for CORD patients. We performed the visual field test and fundus autofluorescence (FAF) measurement and visualized retinal structures with optical coherence tomography (OCT) on the same day. Using binarised FAF images, we identified a low FAF area ratio (LFAR: low FAF/30°). Relationships between age and logMAR visual acuity (VA), central retinal thickness (CRT), central choroidal thickness (CCT), mean deviation (MD) value, and LFAR were investigated. Thirty-seven eyes of 21 CORD patients (8 men and 13 women) were enrolled. The mean patient age was 49.8 years. LogMAR VA and MD were 0.52 ± 0.47 and − 17.91 ± 10.59 dB, respectively. There was a significant relationship between logMAR VA and MD (p = 0.001). LogMAR VA significantly correlated with CRT (p = 0.006) but not with other parameters. Conversely, univariate analysis suggested a significant relationship between MD and LFAR (p = 0.001). In the multivariate analysis, LFAR was significantly associated with MD (p = 0.002). In conclusion, it is useful to measure the low FAF area in patients with CORD. The AF measurement reflects the visual field deterioration but not VA in CORD.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Afsaneh Keramat ◽  
Mina Malary ◽  
Mahmood Moosazadeh ◽  
Nastaran Bagherian ◽  
Mohammad-Reza Rajabi-Shakib

Abstract Background Pregnancy is a unique period with the increased likelihood of psychological changes and emotional disturbances such as depression, anxiety, and stress. In this study, we investigated the factors influencing depression, anxiety, and stress in pregnancy and identify their associations with Sexual Distress (SD) and Genital Self-Image (GSI). Methods This was a descriptive, correlational, cross-sectional study performed using the two-stage cluster sampling method between September 2019 and January 2020. Overall, 295 pregnant women completed a demographics and obstetric information checklist, Depression Anxiety and Stress Scale-21 (DASS-21), Female Genital Self-Image Scale (FGSI), and Female Sexual Distress Scale-Revised (FSDS-R). Results Analysis of Variance (ANOVA) showed significant differences in the mean scores of SD between the groups with varying degrees of depression, anxiety, and stress (P <  0.001) and in the mean score of GSI between the groups with varying degrees of depression (P = 0.01) and anxiety (P <  0.001). In multivariate linear regression analysis, higher (worse) depression, anxiety, and stress scores were found in women with more advanced age and higher SD scores; however, these scores were lower (better) in those with increased gestational age. Lower depression and anxiety scores were associated with moderate satisfaction with income, moderate satisfaction with BI in pregnancy, and lower stress and depression scores were linked to planned pregnancy. Higher (better) GSI score was a predictor of lower depression score, complication in a previous pregnancy was a predictor of higher stress score, and finally, fear of fetal abortion and being a housewife were predictors of a higher anxiety score. Conclusion Various factors contribute to the development of antenatal depression, anxiety, and stress. A positive correlation was found between SD and the severity of depression, anxiety, and stress, while a negative correlation was noted between GSI and the severity of depression and anxiety. Therefore, raising awareness regarding SD and GSI through screening and counseling sessions can have beneficial effects for mothers and their fetuses.


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