scholarly journals Relationships between Sediment Transport and Various Hydrological and Hydraulic Characteristics of Flood Events on Trotuș River (Romania)

2019 ◽  
Author(s):  
Dan Dumitriu
Keyword(s):  
Sediment Transport ◽  
Hysteresis Loops ◽  
Flood Events ◽  
River Channels ◽  
Stream Power ◽  
Sediment Rating Curve ◽  
Type D ◽  
Highly Sensitive ◽  
Type C ◽  
Major Floods

Sediment transport is highly sensitive to flow conditions, showing significant increase during flood events. Based on this principle, this study set out to rank flood events occurring along river Trotuș (Romania) based on the amount of transported sediment and event duration. The 77 flood events recorded from 2000 to 2017 were ranked into 4 classes: type A (4%); type B (16%), type C (14%) and type D (66%). The sediment transport specific for the 4 types of flood events was related to the flow discharge (sediment rating curve and hysteresis effect), the specific stream power and the energy expenditure of these events. More than 60% of the hysteresis loops typical for flood events were clockwise, thus singling out the channel as the main sediment source. Ca. 74% of the total sediment yield was transported at stream power values higher than the 300 Wm-2 threshold, which was exceeded in less than 1% of the investigated timeframe. The changes occurring in the sediment transport rates after major floods show that these events are significant thresholds in the hydrogeomorphic evolution of river channels.

scholarly journals Hydraulic Parameters for Sediment Transport and Prediction of Suspended Sediment for Kali Gandaki River Basin, Himalaya, Nepal

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1229 ◽  
Author(s):  
Mahendra B. Baniya ◽  
Takashi Asaeda ◽  
Shivaram K.C. ◽  
Senavirathna M.D.H. Jayashanka
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Lower Boundary ◽  
Hysteresis Loops ◽  
Coefficient Of Determination ◽  
Hydraulic Parameters ◽  
Stream Power ◽  
Sediment Rating Curve ◽  
General Power ◽  
Land Sliding

Sediment yield is a complex phenomenon of weathering, land sliding, and glacial and fluvial erosion. It is highly dependent on the catchment area, topography, slope of the catchment terrain, rainfall, temperature, and soil characteristics. This study was designed to evaluate the key hydraulic parameters of sediment transport for Kali Gandaki River at Setibeni, Syangja, located about 5 km upstream from a hydropower dam. Key parameters, including the bed shear stress (τb), specific stream power (ω), and flow velocity (v) associated with the maximum boulder size transport, were determined throughout the years, 2003 to 2011, by using a derived lower boundary equation. Clockwise hysteresis loops of the average hysteresis index of +1.59 were developed and an average of 40.904 ± 12.453 Megatons (Mt) suspended sediment have been transported annually from the higher Himalayas to the hydropower reservoir. Artificial neural networks (ANNs) were used to predict the daily suspended sediment rate and annual sediment load as 35.190 ± 7.018 Mt, which was satisfactory compared to the multiple linear regression, nonlinear multiple regression, general power model, and log transform models, including the sediment rating curve. Performance indicators were used to compare these models and satisfactory fittings were observed in ANNs. The root mean square error (RMSE) of 1982 kg s−1, percent bias (PBIAS) of +14.26, RMSE-observations standard deviation ratio (RSR) of 0.55, coefficient of determination (R2) of 0.71, and Nash–Sutcliffe efficiency (NSE) of +0.70 revealed that the ANNs’ model performed satisfactorily among all the proposed models.

scholarly journals Buffering of interglacial landscape evolution due to reduced sediment transport during glacial periods in Bhutan

2021 ◽  
Author(s):  
Larissa de Palézieux ◽  
Kerry Leith ◽  
Simon Loew
Keyword(s):  
Rock Mass ◽  
Sediment Transport ◽  
Progressive Increase ◽  
Alluvial Plain ◽  
Residual Soil ◽  
River Channels ◽  
Stream Power ◽  
Humid Climate ◽  
River Profiles ◽  
Glacial Periods

<p>Fluvial systems provide a primary means of sediment transport in alpine environments. This transport potential is regulated by precipitation, a fundamental contributor to stream power. Here, we investigate the legacy of reduced sediment transport capacity during dryer glacial intervals to fundamentally affect the diverse long-term evolution of 2 alpine catchments in the NW of Bhutan. The landscape in this region is characterized by three distinct geomorphic domains including transport-limited alluvial plains in the Inner Valleys, detachment-limited regimes in narrow valleys with steep hillslopes and high relief, and glacially overprinted low-relief landscapes at the foot of the High Himalayan peaks. The two major drainage basins, the Wong Chhu basin in the West and the Puna Tsang Chhu basin in the East, both traverse these geomorphic domains, yet show marked differences in their river profiles, with the alluvial plain of the Wong basin located 1000 m higher than the Puna Tsang Chhu basin. </p><p>The characteristic difference in elevation and extent of the alluvial infill between the two main basins of NW Bhutan, points to a systematic difference in relative erosional efficacy. For the effects of baselevel fall due to differential uplift on the Himalayan rangefront to be expressed as increased erosional potential in the High Himalaya, sediment deposited in alluvial planes of the Inner Valleys during low stream power glacial periods must first be evacuated during interglacial intervals.  Through a combination of geomorphological mapping and chi analysis of river profiles, we demonstrate that while post-glacial incision today is approaching the upper limit of the alluvial plain in the Puna Tsang Chhu (and can therefore drive bedrock incision through much of a ~40 kYr interglacial interval), the present-day erosional limit in the Wang Chhu is less than half-way through the alluvial fill in the Wang Chhu. It is therefore unlikely rivers in the Wang Chhu have been able to access bedrock or propagate the effects of baselevel fall to the upper extents of the catchment since the mid-Pleistocene transition (MPT). </p><p>The evolution of the fluvial system appears to be reflected in rock mass weathering and hillslope evolution throughout the study area. Engineering geological descriptions of rock mass properties, in particular weathering, recorded at 295 sites over a period of 8 weeks in the region closely associated with alluvial valleys demonstrates a range of weathering grades from fresh rock to residual soil. A progressive increase in weathering degree with increasing elevation above river channels is evident in both catchments, indicating the signal reflects the time since active fluvial erosion ceased (as opposed to a pre-existing rock mass property). We observe higher degrees of weathering in the Puna Tsang Chhu valley, corresponding to the more humid climate in this valley supporting more rapid bedrock weathering. This more efficient transition from rock to soil at lower elevations may hint at a positive feedback in which despite indications of an additional 1000 m of cumulative incision since the MPT, hillslopes have evolved to erode at a rate which approaches that of fluvial incision.</p>

scholarly journals Effect of prostatic apex shape (Lee types) and urethral sphincter length in preoperative MRI on very early continence rates after radical prostatectomy

2021 ◽  
Author(s):  
Mike Wenzel ◽  
Felix Preisser ◽  
Matthias Mueller ◽  
Lena H. Theissen ◽  
Maria N. Welte ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Radical Prostatectomy ◽  
Regression Models ◽  
Urethral Sphincter ◽  
Anatomical Characteristics ◽  
Logistic Regression Models ◽  
Pad Test ◽  
Type D ◽  
Multivariable Logistic Regression ◽  
Type C

Abstract Purpose To test the effect of anatomic variants of the prostatic apex overlapping the membranous urethra (Lee type classification), as well as median urethral sphincter length (USL) in preoperative multiparametric magnetic resonance imaging (mpMRI) on the very early continence in open (ORP) and robotic-assisted radical prostatectomy (RARP) patients. Methods In 128 consecutive patients (01/2018–12/2019), USL and the prostatic apex classified according to Lee types A–D in mpMRI prior to ORP or RARP were retrospectively analyzed. Uni- and multivariable logistic regression models were used to identify anatomic characteristics for very early continence rates, defined as urine loss of ≤ 1 g in the PAD-test. Results Of 128 patients with mpMRI prior to surgery, 76 (59.4%) underwent RARP vs. 52 (40.6%) ORP. In total, median USL was 15, 15 and 10 mm in the sagittal, coronal and axial dimensions. After stratification according to very early continence in the PAD-test (≤ 1 g vs. > 1 g), continent patients had significantly more frequently Lee type D (71.4 vs. 54.4%) and C (14.3 vs. 7.6%, p = 0.03). In multivariable logistic regression models, the sagittal median USL (odds ratio [OR] 1.03) and Lee type C (OR: 7.0) and D (OR: 4.9) were independent predictors for achieving very early continence in the PAD-test. Conclusion Patients’ individual anatomical characteristics in mpMRI prior to radical prostatectomy can be used to predict very early continence. Lee type C and D suggest being the most favorable anatomical characteristics. Moreover, longer sagittal median USL in mpMRI seems to improve very early continence rates.

scholarly journals Sediment Transport and Water Flow Resistance in Alluvial River Channels: Modified Model of Transport of Non-Uniform Grain-Size Sediments

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2038
Author(s):  
Gennady Gladkov ◽  
Michał Habel ◽  
Zygmunt Babiński ◽  
Pakhom Belyakov
Keyword(s):  
Sediment Transport ◽  
Water Flow ◽  
Transport Model ◽  
Flow Characteristics ◽  
Field Measurements ◽  
Field Investigation ◽  
Empirical Modeling ◽  
River Channels ◽  
Channel Deformations ◽  
East European

The paper presents recommendations for using the results obtained in sediment transport simulation and modeling of channel deformations in rivers. This work relates to the issues of empirical modeling of the water flow characteristics in natural riverbeds with a movable bottom (alluvial channels) which are extremely complex. The study shows that in the simulation of sediment transport and calculation of channel deformations in the rivers, it is expedient to use the calculation dependences of Chézy’s coefficient for assessing the roughness of the bottom sediment mixture, or the dependences of the form based on the field investigation data. Three models are most commonly used and based on the original formulas of Meyer-Peter and Müller (1948), Einstein (1950) and van Rijn (1984). This work deals with assessing the hydraulic resistance of the channel and improving the river sediment transport model in a simulation of riverbed transformation on the basis of previous research to verify it based on 296 field measurements on the Central-East European lowland rivers. The performed test calculations show that the modified van Rijn formula gives the best results from all the considered variants.

MRI analysis and surgical treatment of Wassel Type IV duplicated thumbs

2021 ◽  
pp. 175319342098321
Author(s):  
Anyuan Wang ◽  
Jian Ding ◽  
Long Wang ◽  
Tinggang Chu ◽  
Zhipeng Wu ◽  
...  
Keyword(s):  
Type A ◽  
Surgical Reconstruction ◽  
Mri Findings ◽  
Level Of Evidence ◽  
Type D ◽  
Type Iv ◽  
Secondary Operations ◽  
Type C

We present the MRI findings for 39 Wassel Type IV duplicated thumbs in 38 patients. We found that MRI revealed the morphology of the cartilaginous connection between the thumb anlages and the location of the deviation corresponding to the classification of Horii, which allowed precise preoperative planning of corrective osteotomies. All 39 thumbs were available for follow-up after surgical reconstruction at a mean of 29 months (range 25 to 39). Four out of nine Horii Type A cases and all 12 Type B, as well as the six Type C and the six Type D cases, achieved good results according to the Tada scoring system. Five Type A cases achieved fair results with residual stiffness of the interphalangeal joint. No secondary operations were needed. We conclude that MRI proved useful in subclassifying Wassel Type IV duplicated thumbs and may aid in planning the osteotomies needed for their reconstruction. Level of evidence: IV

scholarly journals The effectiveness of TiO2 additions to mortar to maintain initial conditions in terms of its reflectance to solar radiation

2017 ◽  
Vol 17 (3) ◽  
pp. 39-56 ◽  
Author(s):  
Sérgio Roberto Andrade Dantas ◽  
Fulvio Vittorino ◽  
Kai Loh
Keyword(s):  
Solar Radiation ◽  
Ultraviolet Radiation ◽  
Initial Conditions ◽  
Type A ◽  
Just Noticeable Difference ◽  
Type B ◽  
Climate Conditions ◽  
Type D ◽  
Type C ◽  
Over Time

Abstract Contact of facades with degradation agents and direct incidence of ultraviolet radiation on external coatings make them more opaque over time, affecting their colour and reflectance characteristics. This study evaluated the effect of adding different TiO2 contents to mortars applied in concrete substrates in order to verify the reflectance maintenance on surfaces after exposure over time. Mortar with different concentrations of TiO2 (1%, 5%, 10%) were produced in relation to the total dry premix, added as a powder and compared to unpainted mortar without TiO2 (type "A") and painted mortar without TiO2 (type "B"), both used as a reference for colour and reflectance. Exposed over 16 months to climate conditions in São Paulo, regarding the maintenance of reflectance and solar radiation, the results showed that type "B" (0%TiO2) painted mortar presented the best performance. Type "C" (1%TiO2) and type "D" (5%TiO2) unpainted mortar remained more stable. Type "A" (0%TiO2) and type "E" (10%TiO2) unpainted mortar showed greater differences according to the Just Noticeable Difference (JND) range caused by dirt pick up.

scholarly journals Surgical Management of Giant Pituitary Adenomas

1990 ◽  
Vol 17 (1) ◽  
pp. 62-66 ◽  
Author(s):  
Gérard Mohr ◽  
Jules Hardy ◽  
Ronald Comtois ◽  
Hughes Beauregard
Keyword(s):  
Pituitary Adenomas ◽  
Residual Tumor ◽  
Empty Sella ◽  
Csf Leak ◽  
Visual Field Defects ◽  
Pituitary Insufficiency ◽  
Empty Sella Syndrome ◽  
Type D ◽  
Giant Pituitary Adenomas ◽  
Type C

ABSTRACT:During the past 25 years, 77 giant pituitary adenomas have been treated surgically, including suprasellar extensions of type C in 66 cases and of type D in 11 cases. Non-secreting adenomas were present in 53 and secreting adenomas in 24 cases. All patients except 3 presented with significant visual field defects; including bitemporal hemianopia, superior quadranopia or unilateral temporal hemianopia, contralateral blindness in 73% of the cases, and one case with sudden bilateral blindness due to acute pituitary apoplexy. A single transsphenoidal procedure was carried out in 74% of the patients while 11 patients (7%) required re-operations for recurrent or residual tumor. Only 3 patients required a subsequent transcranial procedure. Complications included 1 CSF-leak, 1 empty-sella syndrome and 4 fatal post-operative hematomas. We prefer the transsphenoidal route even in very large or giant pituitary adenomas, since it allows rapid and adequate decompression of the optic nerves and chiasm, avoids major pituitary insufficiency in 60% of the cases and is associated with low morbidity-mortality rates.

scholarly journals Novel classification for multi-ligament knee injury including both tibiofemoral joint factor and patellofemoral joint factor (193)

2021 ◽  
Vol 9 (10_suppl5) ◽  
pp. 2325967121S0030
Author(s):  
Takuya Tajima ◽  
Nami Yamaguchi ◽  
Yudai Morita ◽  
Takuji Yokoe ◽  
Etsuo Chosa
Keyword(s):  
Patellofemoral Joint ◽  
Cruciate Ligament ◽  
Knee Extensor ◽  
Quadriceps Tendon ◽  
Collateral Ligament ◽  
Patella Tendon ◽  
Joint Factor ◽  
Type D ◽  
Neurovascular Injury ◽  
Type C

Objectives: Multi-ligament knee injury (MLKI) shows very varied symptoms which was depended on the combination of injured ligaments. Schenck`s knee dislocation classification which was one of useful classifications for surgeon in decision making. However, Schenck`s classification is only referred to the factors of cruciate ligament and collateral ligament. It is well known that knee joint consists of two important structure; tibiofemoral joint and patellofemoral joint. Knee extensor structure is one of important factors of knee function. Dislocation of patella, quadriceps or patella tendon rupture are sometimes occurred in the knee trauma and provided severe instability or disability of knee function. Of course, these injuries were also target for consideration of treatment. Moreover, knee extensor structure disruption was sometimes combined with other knee ligaments such as cruciate or collateral ligament. Unfortunately, the case of combined cruciate or collateral ligament with knee extensor structure disruption could not classified in the previous classifications. Therefore, we proposed new classification for MLKI which contains both femorotibial factor and patellofemoral factor. We established and defined several categories in accordance with number of injured ligaments, combination of injured ligaments, and additional combined injury such as fracture, nerve injury, vascular injury. It was hypothesized that all cases at least two ligaments involved situation not only combination of tibiofemoral factor, but also including patellofemoral factor, could classify and divide into the new established classification. Methods: The present study was conducted in 2019, involving patient who was diagnosed MLKI at our institute. The study followed both retrospective and prospective observational design including data collected from Apr 2007 to Aug 2020. The experimental design was reviewed and approved (Accession No. 0-0602) by the Ethics Committee of our institute. The procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2000. Inclusion criteria were the cases of two or more injured ligaments diagnosed clinically and by MRI testing and dynamic X-ray testing. Detail of ligament around knee joint were defined as follows; ‘cruciate ligaments` which contains ACL and PCL; ‘collateral ligaments` which contains MCL and posterolateral corner (PLC) certainly include lateral collateral ligament, and; ‘patellofemoral joint factor` which contains medial patellofemoral ligament (MPFL), quadriceps tendon and patellar tendon. Exclusion criteria was any prior knee surgery cases. Total 65 MLKI cases were met the inclusion criteria and were enrolled in this study. We focused on the number of injured ligaments, combination of the injured ligaments, and complication such as fracture, neurovascular injury. Based on the number of injured ligaments, 2 injured ligaments case was categorized as Type A, 3 injured ligaments case was as Type B, 4 ligaments case was as Type C, and 5 ligaments case was as Type D, respectively. We defined that injured ligament counting was follows; cruciate ligament group; ACL and/or PCL, collateral ligament group; MCL and/or PLC, and PF joint group; one of the MPFL or patellar tendon or quadriceps tendon. Depended on the combination of injured ligaments, each case was subdivided into 1 to 5 in Type A and B, into 1 to 3 in Type C. Additional injuries with MLKI were also subdivided as follows; MLKI with fracture case was defined as X, with neurovascular injury case was as Y, and both fracture and neurovascular injury case was as Z. (Table 1, 2, 3, and 4). For each case, final decision of injured ligament was recorded under clinical examination and image evaluation. MLKI cases were divided into both Schenk’s KD classification and the present new established classification. Results: Fifty-seven of 65 cases were divided into Schenck’s KD classification as follows; 19 cases of ACL+MCL and 13 cases of ACL+PLC and 9 cases of PCL+PLC and 2 cases of PCL+MCL as KD-?, 4cases of ACL+PCL as KD-? and one case of ACL+PCL with fracture as KD-?2, 6 cases of ACL+MCL, 2 cases of ACL+PCL+PLC as KD-?, and 1 case of ACL+PCL+MCL+MCL with fracture as KD-?5, respectively. Eight cases (12.3%) could not be divided into Schenk’s KD classification. Combination of these 8 cases were follows; 2 cases of PLC+MPFL, and single case of ACL+MCL+PLC, ACL+PCL+MCL+PLC+MPFL, ACL+MPFL, PCL+PLC+MPFL+ fracture, ACL+MCL+MPFL, and PCL+ patella tendon, respectively. Seven of 8cases contained PF joint factor injury. At the established new classification for MLKI, all 65 cases were divided into each category, successfully. PLC+MPFL was divided into Type-A5, ACL+MCL+PLC was Type-B2, ACL+PCL+MCL+PLC+MPFL was Type-D, ACL+MPFL was Type-A4, PCL+PLC+MPFL was Type-B3-X, ACL+MCL+MPFL was Type-B3, and PCL+ patella tendon was Type-A4. Conclusions: Several classification systems have been reported for diagnosis of MLKI cases. Kennedy `s classification and the French Society of Orthopedic Surgery and Traumatology 2008 classification were focused on the mechanism and direction of dislocation. These classifications were available for understanding comprehension mechanism of injured knee. However, previous classifications including Schenck’s classification were lack of PF joint factor. It is very important for knee surgeon that understanding injured mechanism as well as number of injured ligaments and combination of injured ligaments for decision making for surgery. The present classification was useful for MLKI case which contains both tibiofemoral factor and patellofemoral factor.

scholarly journals Development of polyvalent toxoid Clostridium perfringens against anaerobic enterotoxaemia in young cattle and small ruminants

2021 ◽  
Vol 282 ◽  
pp. 04009
Author(s):  
F.Kh. Pulotov ◽  
O.D. Nazarova ◽  
N.A. Akhmadov ◽  
A.I. Karimzoda
Keyword(s):  
Nutrient Medium ◽  
Small Ruminants ◽  
Farm Animals ◽  
Drug Preparation ◽  
Type D ◽  
Industrial Strains ◽  
Type C ◽  
Young Cattle ◽  
C 30 ◽  
Selection Of

The authors of the article presents the results of the development of a polyvalent toxoid from C.perfringens strains against anaerobic enterotoxaemia of young cattle and small ruminants and an assessment of its effectiveness. It is presented the data on the selection of the recipe composition of the nutrient medium, the cultivation of industrial strains, the process of drug preparation, the selection of the optimal ratio of components and the method of controlling the effectiveness. Sequential cultivation of industrial strains of C.perfringens was carried out by cultivating them in flasks, bottles and bioreactors in the nutrient medium developed by the authors, consisting of: 12.0 g/l - liver extract; 25.0 g/l - casein-peptone; 3.2g/l –K2HPO4; 1.8 g/l – KH2PO4; 0.5 g/l – MgSO4. The development of the drug included the selection of optimal and balanced ratios of C. perfringens type A toxoids - 15 IU/ml, C.perfringens type B - 20 IU/ml, C.perfringens type C - 30 IU/ml, C. perfringens type D - 30 IU/ml, which ensured 100% protection of the immunized animals. Studies on laboratory and farm animals revealed the harmlessness, areactogenicity of the drug, which stimulated the development of immunity and resistance to the toxic effects of all strains of C.perfringens.

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