scholarly journals VARIATION OF SEDIMENT SUSPENSION IN OSCILLATORY FLOW

1984 ◽  
Vol 1 (19) ◽  
pp. 155 ◽  
Author(s):  
Carsten Staub ◽  
Ivar G. Jonsson ◽  
Ib A. Svendsen

Different syphon type suspended load probes were used together with a newly developed 'carousel' sampler for measurements of the instantaneous sediment concentration in turbulent oscillatory flow over a sand bed. Shields parameters were well above the rippled/flat bed transition region, resulting in intense sediment transport over a flat bed. The measurements were performed at different levels in a large oscillating water tunnel. They showed some characteristic features of the temporal concentration variation and of the variation with height of the mean concentration. Also a pronounced effect of the orientation of the suction tube relative to the flow was observed.

1972 ◽  
Vol 1 (13) ◽  
pp. 55
Author(s):  
J. Kirkegarrd Jensen ◽  
Torben Sorenson

The paper describes a procedure for obtaining field data on the mean concentration of sediments in combination of waves and currents outside the breaker zone, as well as some results of such measurements. It is assumed that the current turbulence alone is responsible for the maintenance of the concentration profile above a thin layer close to the bottom, in which pick-up of sediments due to wave agitation takes place. This assumption gives a good agreement between field data and calculated concentration profiles.


Author(s):  
Rahmat Bangun Giarto ◽  
Bambang Agus Kironoto ◽  
Bambang Yulistiyanto ◽  
Totok Sulistyo

Angkutan sedimen suspensi merupakan permasalah yang kerap terjadi pada sungai alami dan dapat mengakibatkan pendangkalan pada sungai. Aliran air yang tercampur dengan sedimen berbutir kasar (bed load) akan lebih cepat mengendap dibandingkan dengan sedimen berbutir halus (suspended load) yang akan terangkut mengikuti aliran sungai. Hal ini dapat mengakibatkan berkurangnya kualitas dan kuantitas dalam pemanfaatan air di sungai. Penelitian dilakukan dengan cara mengukur kecepatan dan konsentrasi sedimen suspensi menggunakan dua parameter yaitu pengukuran arah vertikal dan pengukuran arah transversal. Pengukuran menggunakan metode Point Itegrated Sampling (PIS). Opcon Probe digunakan untuk mengukur konsentrasi sedimen suspensi sedangkan propeller currentmeter digunakan untuk pengukuran kecepatan aliran. Pada saat pelaksanaan pengamatan kedua alat ukur tersebut dimasukkan kedalam air yang mengalir pada tampang melintang di sungai. Konsentrasi sedimen suspensi mengalami peningkatan saat  mendekati dasar sungai dan mengalami penurunan saat mendekati permukaan sungai. Persamaan Rouse dapat digunakan dalam mempredisksi distribusi sedimen suspensi pada tengah sungai, sedangkan untuk arah transversal atau posisi tidak ditengah sungai (0,5B) seperti di tepi sungai profil distribusi konsentrasi sedimen suspensi tidak cukup baik untuk memprediksi distribusi konsentrasi sedimen suspensi  dengan persamaan Rouse. Diperlukan faktor koreksi β untuk memprediksi distribusi konsentrasi sedimen suspensi pada tepi sungai dengan nilai faktor koreksi β > 1.Suspension sediment transportation is the problem which is frequently occurs in the bottom of natural rivers, and it sometimes causes rivers shallowing. The mixing between water and coarse grain sediment or bed load will settle down faster rather than finer grain sediment or suspended load that will be transported further by stream water. Due of those can reduce both quality and quantity of river water. This research was conducted by measurement of sediment suspension concentration using two parameters which are vertical and transversal measurement. Point Integrated Sampling was employed in the measurement processes. Opcon probe was used to measure suspended sediment concentration meanwhile the propeller current meter was used to measure water velocity. In the implementation and observation both of measurement tools was drowned in the flowing water, in position  the cross section of rivers. Closer to the rivers bottom, the sediment suspension concentration is increased in the contrary it is decreased in concentration close to the surface. Rouse equation is able to predict the distribution of sediment suspension in the middle of the river, and when the transversal direction or location is not in the middle of river (0.5B) such as in the river profile side, Rouse equation is not good enough to predict the distribution of sediment suspension concentration. The correction factor (β) is needed in predicting concentration  of sediment suspension in rivers side, where  β > 1.


1983 ◽  
Vol 22 (05) ◽  
pp. 246-250 ◽  
Author(s):  
M. Al-Hilli ◽  
H. M. A. Karim ◽  
M. H. S. Al-Hissoni ◽  
M. N. Jassim ◽  
N. H. Agha

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2 2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.


1967 ◽  
Vol 56 (4) ◽  
pp. 619-625 ◽  
Author(s):  
Hans Jacob Koed ◽  
Christian Hamburger

ABSTRACT Comparison of the dose-response curves for LH of ovine origin (NIH-LH-S8) and of human origin (IRP-HMG-2) using the OAAD test showed a small, though statistically significant difference, the dose-response curve for LH of human origin being a little flatter. Two standard curves for ovine LH obtained with 14 months' interval, were parallel but at different levels of ovarian ascorbic acid. When the mean ascorbic acid depletions were calculated as percentages of the control levels, the two curves for NIH-LH-S8 were identical. The use of standards of human origin in the OAAD test for LH activity of human preparations is recommended.


1967 ◽  
Vol 55 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Benno Runnebaum ◽  
Josef Zander

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.


Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1382
Author(s):  
Olga Martyna Koper-Lenkiewicz ◽  
Violetta Dymicka-Piekarska ◽  
Anna Justyna Milewska ◽  
Justyna Zińczuk ◽  
Joanna Kamińska

The aim of the study was the evaluation whether in primary colorectal cancer (CRC) patients (n = 55): age, sex, TNM classification results, WHO grade, tumor location (proximal colon, distal colon, rectum), tumor size, platelet count (PLT), mean platelet volume (MPV), mean platelet component (MCP), levels of carcinoembryonic antigen (CEA), cancer antigen (CA 19-9), as well as soluble lectin adhesion molecules (L-, E-, and P-selectins) may influence circulating inflammatory biomarkers: IL-6, CRP, and sCD40L. We found that CRP concentration evaluation in routine clinical practice may have an advantage as a prognostic biomarker in CRC patients, as this protein the most comprehensively reflects clinicopathological features of the tumor. Univariate linear regression analysis revealed that in CRC patients: (1) with an increase in PLT by 10 × 103/μL, the mean concentration of CRP increases by 3.4%; (2) with an increase in CA 19-9 of 1 U/mL, the mean concentration of CRP increases by 0.7%; (3) with the WHO 2 grade, the mean CRP concentration increases 3.631 times relative to the WHO 1 grade group; (4) with the WHO 3 grade, the mean CRP concentration increases by 4.916 times relative to the WHO 1 grade group; (5) with metastases (T1-4N+M+) the mean CRP concentration increases 4.183 times compared to non-metastatic patients (T1-4N0M0); (6) with a tumor located in the proximal colon, the mean concentration of CRP increases 2.175 times compared to a tumor located in the distal colon; (7) in patients with tumor size > 3 cm, the CRP concentration is about 2 times higher than in patients with tumor size ≤ 3 cm. In the multivariate linear regression model, the variables that influence the mean CRP value in CRC patients included: WHO grade and tumor localization. R2 for the created model equals 0.50, which indicates that this model explains 50% of the variance in the dependent variable. In CRC subjects: (1) with the WHO 2 grade, the mean CRP concentration rises 3.924 times relative to the WHO 1 grade; (2) with the WHO 3 grade, the mean CRP concentration increases 4.721 times in relation to the WHO 1 grade; (3) with a tumor located in the rectum, the mean CRP concentration rises 2.139 times compared to a tumor located in the distal colon; (4) with a tumor located in the proximal colon, the mean concentration of CRP increases 1.998 times compared to the tumor located in the distal colon; if other model parameters are fixed.


Author(s):  
Nazeefa Fatima ◽  
Munazza Khan ◽  
Muhammad Shuaib Kabeer

This study was conducted to determine the mean concentration of heavy metals such as lead (Pb), copper (Cu), zinc (Zn), chromium (Cr), manganese (Mn), nickel (Ni), selenium (Se), magnesium (Mg), and iron (Fe) in canned/packed fruits juices, collected from various stores in Lahore in a period of three months. These juices were categorized into four groups; local packed and canned and also imported packed and canned products. Every group consisted of ten samples. By using the di-acid digestion method, the collected samples were digested and analyzed under Atomic Absorption Spectrophotometer (AAS). The results indicated that the mean values of 7 out of 9 tested heavy metals including Pb, Mg, Ni, Fe, Cr, Se and Mn were above permissible limits (set by WHO) in all four understudy groups. Therefore, it was concluded that commercially available fruit juices are not all safe according to their heavy metals content for the human consumption despite their nutritive values.


2011 ◽  
Vol 50 (No. 2) ◽  
pp. 65-69 ◽  
Author(s):  
J. Blažek

Incidences of powdery mildew were repeatedly evaluated for two years on 1 420 young seedlings of 20 progenies (of different levels of mildew susceptibility) in a green house, and then for 10 years on 642 seedlings in an orchard. Part of the seedlings in the orchard were pre-selected for the characteristic and others not. Except for the first scoring done in the first year, there was no correlation between mildew incidence on individual seedlings in the green house and their mean performance in the orchard. The seedlings with scores above 6 (resistant or tolerant) at the first stage of evaluation in the green house, however, yielded four times more desirable seedlings after final selection in the orchard than the mean of the total. The progenies that had a better healthy state as a whole yielded more partially resistant genotypes than those with low mean scores. Therefore, the progenies that most rapidly develop infestation on the whole lot should be discarded, whereas those that retain a healthy state longer should be subjected to individual selection according to the previous item.


Plant Disease ◽  
2016 ◽  
Vol 100 (12) ◽  
pp. 2427-2433 ◽  
Author(s):  
Sahar Arabiat ◽  
Mohamed F. R. Khan

Rhizoctonia damping-off and crown and root rot caused by Rhizoctonia solani are major diseases of sugar beet (Beta vulgaris L.) worldwide, and growers in the United States rely on fungicides for disease management. Sensitivity of R. solani to fungicides was evaluated in vitro using a mycelial radial growth assay and by evaluating disease severity on R. solani AG 2-2 inoculated plants treated with fungicides in the greenhouse. The mean concentration that caused 50% mycelial growth inhibition (EC50) values for baseline isolates (collected before the fungicides were registered for sugar beet) were 49.7, 97.1, 0.3, 0.2, and 0.9 μg ml−1 and for nonbaseline isolates (collected after registration and use of fungicides) were 296.1, 341.7, 0.9, 0.2, and 0.6 μg ml−1 for azoxystrobin, trifloxystrobin, pyraclostrobin, penthiopyrad, and prothioconazole, respectively. The mean EC50 values of azoxystrobin, trifloxystrobin, and pyraclostrobin significantly increased in the nonbaseline isolates compared with baseline isolates, with a resistant factor of 6.0, 3.5, and 3.0, respectively. Frequency of isolates with EC50 values >10 μg ml−1 for azoxystrobin and trifloxystrobin increased from 25% in baseline isolates to 80% in nonbaseline isolates. Although sensitivity of nonbaseline isolates of R. solani to quinone outside inhibitors decreased, these fungicides at labeled rates were still effective at controlling the pathogen under greenhouse conditions.


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