scholarly journals Regularity of transportation for cohesive bank-collapsed materials

2021 ◽  
Author(s):  
Guosheng Duan ◽  
Haifei Liu
Keyword(s):  
Suspended Load ◽  
Bed Load ◽  
Efficiency Coefficient ◽  
Flume Experiments ◽  
Experimental Conditions ◽  
Channel Evolution ◽  
River Evolution ◽  
Sediment Carrying Capacity ◽  
Suspended Loads

Abstract. The transportation of bank-collapsed materials is a key issue among river evolution processes. In this study, a series of flume experiments were conducted to monitor riverbank collapse processes and to explore the regularity of transportation for cohesive collapsed materials. The collapsed materials, both the bed and suspended loads, that transformed from collapsed materials were intensively evaluated under experimental conditions. The results showed that the collapsed materials contributed to 12～20 % sedimentation in situ, 8～14 % suspended loads and 70～80 % bed loads. In addition, the bed load motion efficiency coefficient (eb), suspended load motion efficiency coefficient (es) and sediment carrying capacity factor (U3/gRω) were introduced to describe the transportation of collapsed materials in terms of energy dissipation. This research provides theoretical and practical benefits for predicting channel evolution processes.

In situ monitoring of isophorone diisocyanate-based flexible polyurethane foams formation

2016 ◽  
Vol 54 (1) ◽  
pp. 37-52 ◽  
Author(s):  
I Eceiza ◽  
L Irusta ◽  
A Barrio ◽  
MJ Fernández-Berridi
Keyword(s):  
Foam Height ◽  
Polyurethane Foams ◽  
In Situ Monitoring ◽  
Generation Process ◽  
Isophorone Diisocyanate ◽  
Experimental Conditions ◽  
Foaming Process ◽  
Foam Generation ◽  
Flexible Polyurethane

Novel isophorone diisocyanate-based flexible polyurethane foams were prepared by the one-step method in a computerized foam qualification system (FOAMAT). The experimental conditions to obtain this type of foams, in relation to the nature and concentration of catalysts as well as the reaction temperature, were established as no data were available in scientific literature. The chemical reactions occurring during the foam generation process were monitored in situ by attenuated total reflectance-FTIR spectroscopy. The kinetics of the foam generation was fitted to an nth order model and the data showed that the foaming process adjusted to a first-order kinetics. The physical changes as pressure, foam height, and dielectric polarization were monitored by the FOAM software (FOAMAT). According to these parameters, the foaming process was divided into four steps: bubble growth, bubble packing, cell opening, and final curing.

scholarly journals Application of an enzymatic cascade reaction for the synthesis of the emeraldine salt form of polyaniline

2021 ◽  
Author(s):  
Minoru Kurisu ◽  
Reinhard Kissner ◽  
Masayuki Imai ◽  
Peter Walde
Keyword(s):  
Cascade Reaction ◽  
Emeraldine Salt ◽  
Salt Form ◽  
Experimental Conditions ◽  
Peroxidase Isoenzyme ◽  
Large Unilamellar Vesicles ◽  
Dark Green ◽  
Catalyzed Oxidation ◽  
Reference Reaction

AbstractThe synthesis of the emeraldine salt form of polyaniline (PANI-ES) from aniline with Aspergillus sp. glucose oxidase (GOD), d-glucose, dissolved O2, and horseradish peroxidase isoenzyme C (HRPC) in the presence of large unilamellar vesicles of AOT (sodium bis-(2-ethylhexyl)sulfosuccinate) as templates at pH = 4.3 and T ~ 25 °C was investigated in a systematic way. In this cascade reaction mixture, the oxidation of aniline is catalyzed by HRPC with H2O2 that is formed in situ as byproduct of the GOD-catalyzed oxidation of d-glucose with O2. Under the elaborated experimental conditions which we considered ideal, the formation of PANI-ES products is evident, as judged by UV/Vis/NIR and EPR measurements. Comparison was made with a reference reaction, which was run under similar conditions with added H2O2 instead of GOD and d-glucose. Although the reference reaction was found to be superior, with the cascade reaction, PANI-ES products can still be obtained with high aniline conversion (> 90%) within 24 h as stable dark green PANI-ES/AOT vesicle dispersion. Our results show that the in situ formation of H2O2 does not prevent the inactivation of HRPC known to occur in the reference reaction. Moreover, the GOD used in the cascade reaction is inactivated as well by polymerization intermediates.

Numerical Investigation of Local Scour Around Submerged Pipeline in Shoaling Conditions

2018 ◽  
Author(s):  
Ming-ming Liu ◽  
Ming Zhao ◽  
Lin Lu
Keyword(s):  
Water Waves ◽  
Slope Angle ◽  
Suspended Load ◽  
Local Scour ◽  
Navier Stokes ◽  
Bed Load ◽  
Scour Depth ◽  
Two Dimensional ◽  
Sediment Mass ◽  
Subsea Pipelines

Water waves play an important role in local scour around subsea pipelines laid on the sandy seabed, especially in shallow water regions. In this paper, a two-dimensional numerical model is employed to predict local scour around submarine pipelines under water waves in shoaling condition. The motion of water under waves is simulated by solving the Reynolds Averaged Navier-Stokes (RANS) equations. The evolution of the seabed surface near the pipeline is predicted by solving the conservation of the sediment mass, which transport in the water in the forms of bed load and suspended load. The main aim of this study is to investigate the effect of the seabed slope on the scour profiles and scour depth. To achieve this aim, numerical simulations of scour around a pipeline on a flat seabed and on a slope seabed with a slope angle of 15° are conducted for various wave conditions.

The Effect of Lesion Characteristic on Remineralization and Model Sensitivity

1992 ◽  
Vol 71 (3_suppl) ◽  
pp. 811-813 ◽  
Author(s):  
F. Schäfer ◽  
S.J. Raven ◽  
T.A. Parr
Keyword(s):  
Real Life ◽  
High Sensitivity ◽  
Lesion Size ◽  
Experimental Conditions ◽  
Treatment Groups ◽  
Human Enamel ◽  
Enamel Sample ◽  
Two Factors ◽  
Treatment Bias

A major criterion for assessing the value of any experimental model in scientific research is the degree of correspondence between its results and data from the real-life process it is designed to model. Intra-oral models aimed at predicting the anti-caries efficacy of toothpastes or other topical treatments should therefore be calibrated against treatments proven to be effective in a caries clinical trial. For this to be achieved, it is necessary that a model with high sensitivity be designed, while at the same time retaining relevance to the process to be modeled. This means that the effects of the various experimental conditions and parameters of the model on its performance must be understood. The purpose of this paper was to assess the influence of two specific factors on the performance of an in situ enamel remineralization model, which is based on human enamel slabs attached to partial dentures. The two factors are initial lesion severity and origin of enamel sample. The results indicated that initial lesion size affected whether net remineralization or net demineralization occurred during in situ treatment. Samples with an initial range of from 1500 to 2500 (ΔZ) tended more toward demineralization than did samples with ΔZ > 3500. This means that treatment groups must be well-balanced with respect to initial lesion size. Differences in initial demineralization severity between different tooth locations must also be considered so that systematic treatment bias can be avoided. The solution used in the model discussed here is based on a balanced experimental design, which allows this effect to be taken into account in the data analysis.

scholarly journals Regression analysis between sediment transport rates and stream discharge for the Nestos River, Greece

2013 ◽  
Vol 14 (3) ◽  
pp. 362-370
Keyword(s):  
Sediment Transport ◽  
Suspended Load ◽  
Bed Load ◽  
Regression Curve ◽  
Degree Polynomial ◽  
Stream Discharge ◽  
Nestos River ◽  
Polynomial Curve ◽  
Load Transport ◽  
Bed Load Transport

Systematic measurements of sediment transport rates and water discharge were conducted in the Nestos River (Greece), at a place located between the outlet of Nestos River basin and the river delta. This basin area is about 838 km2 and lies downstream of the Platanovrysi Dam. Separate measurements of bed load transport and suspended load transport were performed at certain cross sections of the Nestos River. In this study, relationships between sediment transport rates and stream discharge for the Nestos River are presented. A nonlinear regression curve (4th degree polynomial curve; r2 equals 0.62) between bed load transport rates and stream discharge, on the basis of 63 measurements, was developed. In addition, a nonlinear regression curve (5th degree polynomial curve; r2 equals 0.95) between suspended load transport rates and stream discharge, on the basis of 65 measurements, was developed. The relatively high r2 values indicate that both bed load transport rates and, especially, suspended load transport rates can be predicted as a function of the stream discharge in the Nestos River. However, the reliability of the regression equations would have been higher if more measured data were available.

scholarly journals ANALISIS SEDIMENTASI PADA BENDUNG BERINGEN SILA DESA STOWE BERANG KECAMATAN UTAN KABUPATEN SUMBAWA

2018 ◽  
Author(s):  
Badaruddin ◽  
Tri Satriawansyah ◽  
Faturrahman
Keyword(s):  
Economic Cooperation ◽  
Suspended Load ◽  
Bed Load

Bendung Beringin Sila merupakan salah satu bendung yang dibangun dengan biaya bantuan dari luar negeri yaitu Overseas Economic Cooperation Fund (OECF) – Jepang, yang berlokasi di desa Stowe Brang Kecamatan Utan Kabupaten Sumbawa yang digunakan sebagai sarana irigasi untuk mengairi areal persawahan seluas 2.400 ha. Melihat kondisi saat ini, Bendung Beringin Sila mengalami penumpukan sedimen di hulu bendung yang menutupi mercu bendung, bahkan saat banjir sekalipun sedimen dapat terlihat. Tujuan penelitian ini untuk mengetahui besarnya sedimentasi tahunan serta mengetahui besar perbandingan sedimen dasar (Bed Load) dengan sedimen melayang (Suspended Load).Untuk menghitung besar debit aliran sungai pada Sub Daerah Aliran Sungai (DAS), digunakan persamaan dasar manning yang pengaruhi oleh data curah hujan dari satu stasiun selama 5 tahun terakhir. Kemudian diuji menggunakan metode Log Person Tipe III. Serta menghitung curah hujan dan debit banjir.Besarnya sedimentasi permukaan pada Sub Daerah Aliran Sungai (DAS) Utan, digunakan persamaan dasar yang dikenal dengan rumus Schoklitsch dan Forchemeir digunakan untuk menganalisa Sedimen Dasar (Bed Load) dan Sedimen Melayang (Suspended Load) yang masuk ke Bendung Beringin Sila.Berdasarkan hasil analisa diperoleh besar Sedimen Dasar (QSD) pada saat debit normal sebesar 635712,105 ton/tahun, dan Sedimen Melayang (QSM) sebesar 1052356,320 ton/tahun, sedangkan pada saat banjir maksimum (Qr) Sedimen Dasar (Bed Load) sebesar 635712,105 ton/tahun dan Sedimen Melayang (Suspended Load) sebesar 4001918,400 ton/tahun.

scholarly journals Analisa Angkutan Sedimen Pada Hulu Bendung Aepodu Kabupaten Konawe Selatan

2021 ◽  
Vol 2 (1) ◽  
pp. 1-7
Author(s):  
Ramadhan Hidayat Putra ◽  
Amad Syarif Syukri ◽  
Catrin Sudarjat ◽  
Vickky Anggara Ilham
Keyword(s):  
Sediment Transport ◽  
River Flow ◽  
Suspended Load ◽  
Bedload Transport ◽  
Bed Load ◽  
Average Flow ◽  
Load Transport ◽  
Bed Load Transport ◽  
Transport Analysis

Research on Aepodu Weir Sediment Transport Analysis in South Konawe District, based on observations in the field, Aepodu Weir hasa sediment buildup that has now exceeded the height of the weirlight house. The purpose of the study was to analyze the magnitudeof Aepodu river flow and to analyze the amount of sedimenttransport that occurred in the Aepodu dam. The method used todetermine the amount of bed load transport uses stchoklitscht, whilefor transporting suspended load using forcheimer.The results of the analysis of the average flow of the Aepodu riverwere 3,604 m3/ second. Sediment transport that occurs in Aepoduweir is Bedload transport (Qb) of 291625.771 tons / year, andsuspended load transport (Qs) of 16972,423 tons / year, so that thetotal sediment transport (QT) is 308598,194 tons / year.

Flume Experiments on the Erosive Energy of Bed Load Impacts on Rough and Planar Beds

2021 ◽  
Author(s):  
J. E. Larimer ◽  
E. M. Yager ◽  
B. J. Yanites ◽  
A. J. C. Witsil
Keyword(s):  
Bed Load ◽  
Flume Experiments

Industrial passion fruit residue as ruminant feed

1998 ◽  
Vol 1998 ◽  
pp. 173-173
Author(s):  
C.M. Korndörfer ◽  
A. L. Abdalla ◽  
E. Crossara
Keyword(s):  
Nutritive Value ◽  
Ammonia Nitrogen ◽  
Neutral Detergent Fiber ◽  
Passion Fruit ◽  
Experimental Conditions ◽  
Plastic Bags ◽  
Treatment Structure ◽  
Good Medium ◽  
Male Sheep

In the Brazilian savanna region, which covers 2.1 million km2, roughage production is irregular during the year. However the manufacture of passion fruit juice produces approximately 13,000,000 ton per year of industrial residue which consist of fruit pulp and seeds (FPSR) (Medina, 1980). Beef and dairy cattle farmers are feeding it to their livestock with no knowledge of its nutritive value or concern for its pollution aspects. The FPSR is left in piles outside on the ranches and fluid effluent is often observed reaching streams and contaminating the environment. Furthermore it is a good medium for fly proliferation which stresses the animals and reduces profits. The objective of this study was to demonstrate to the farmers a better way for storing the FPSR and to determine its nutritional value for ruminants.The FPSR was stored in triplicate experimental mino-silos (200 1) in a complete 2x2 factorial design to observe the effects of 48-h wilting (sun dry) and anaerobic conditions. Open mini-silos were left uncovered while in anaerobic mini-silos the FPSR was sealed in plastic bags and covered with sacks of soil. Treatments were: Tl wilted and anaerobic; T2 wilted and open; T3 unwilted and anaerobic; T4 unwilted and open. The mini-silos were sampled at 30-day intervals for up to ll2 days. The samples were analysed for dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), lignin (LIN), phenolic compounds (PHEN), ammonia nitrogen (NH3 -N), soluble carbohydrats (CHO sol) and pH. The DM effective degradability (DMED) was determined “in situ” using six Santa Inês male sheep fitted with rumen cannula and fed with a mixture 80:20 diet containing grass pasture and concentrate (160 g CP/kg DM). The effects of experimental conditions were analysed in a factorial treatment structure and tested by analysis of variance. Treatment means were compared by contrasts.

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