Channel Morphology Below Reservoir Storage Projects

1977 ◽  
Vol 4 (4) ◽  
pp. 279-284 ◽  
Author(s):  
Paul G. Buma ◽  
J. Chadwick Day
Keyword(s):  
Cross Sections ◽  
The United States ◽  
Cross Sectional Area ◽  
Main Stream ◽  
Sectional Area ◽  
Stream Channel ◽  
Cross Sectional ◽  
Channel Changes ◽  
Reservoir Storage ◽  
Crosssectional Area

Reservoir storage projects are known to alter significantly the environmental settings in which they are established. Extensive data are required to assess quantitatively the physical effects of human interference with rivers. Methodologies must be developed to permit continual monitoring of such changes, so that environmental effects of storage projects may be considered in more integrated, comprehensive plans than hitherto for future river-development efforts.This study documents stream-channel changes over a five-years period following reservoir completion at eight cross-sections on the main stream below a dam and on one tributary. Of eight main-stream sections, four are increasing in cross-sectional area, namely numbers one, five, six, and seven. Of these, the crosssectional area of numbers one and seven is increasing laterally and that of five and six is increasing vertically. The average annual degradation of sections five and six is 0.092 m over the study period, compared with an average of 0.031 m in the United States over the first 10–15 years after dam closure. Sections three, eight, and nine, are shitfing laterally without a crosssectional area increase, while of sections 2 and 4 the cross-sectional area remained largely unchanged.Extraction of most of the sediment load by the new reservoir led to increased erosion of the stream channel below the dam. However, it is not always predictable whether the increased erosive power of released clearwater will induce the ongoing channel to erode its bed, widen its section, or cause the bed to move laterally. Nearly all of the nine Deer Creek study sections experienced one of these changes over the study period of five years.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

Comparison of the Cross Sectional Area, the Loss in Volume and the Mechanical Properties of LAE442 and MgCa0.8 as Resorbable Magnesium Alloy Implants after 12 Months Implantation Duration

2010 ◽  
Vol 638-642 ◽  
pp. 675-680 ◽  
Author(s):  
Martina Thomann ◽  
Nina von der Höh ◽  
Dirk Bormann ◽  
Dina Rittershaus ◽  
C. Krause ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Degradation Process ◽  
Cross Sectional Area ◽  
Bending Test ◽  
Sectional Area ◽  
Cross Sectional ◽  
Initial Strength ◽  
Three Point Bending ◽  
The Cross

Current research focuses on magnesium based alloys in the course of searching a resorbable osteosynthetic material which provides sufficient mechanical properties besides a good biocompatibility. Previous studies reported on a favorable biocompatibility of the alloys LAE442 and MgCa0.8. The present study compared the degradation process of cylindrical LAE442 and MgCa0.8 implants after 12 months implantation duration. Therefore, 10 extruded implants (2.5 x 25 mm, cross sectional area 4.9 mm²) of both alloys were implanted into the medullary cavity of both tibiae of rabbits for 12 months. After euthanization, the right bone-implant-compound was scanned in a µ-computed tomograph (µCT80, ScancoMedical) and nine uniformly distributed cross-sections of each implant were used to determine the residual implants´ cross sectional area (Software AxioVisionRelease 4.5, Zeiss). Left implants were taken out of the bone carefully. After weighing, a three-point bending test was carried out. LAE442 implants degraded obviously slower and more homogeneously than MgCa0.8. The mean residual cross sectional area of LAE442 implants was 4.7 ± 0.07 mm². MgCa0.8 showed an area of only 2.18 ± 1.03 mm². In contrast, the loss in volume of LAE442 pins was more obvious. They lost 64 % of their initial weight. The volume of MgCa0.8 reduced clearly to 54.4 % which corresponds to the cross sectional area results. Three point bending tests revealed that LAE442 showed a loss in strength of 71.2 % while MgCa0.8 lost 85.6 % of its initial strength. All results indicated that LAE442 implants degraded slowly, probably due to the formation of a very obvious degradation layer. Degradation of MgCa0.8 implants was far advanced.

scholarly journals A Study of Sedimentation at the River Estuary on the Change of Reservoir Storage

2018 ◽  
Vol 31 ◽  
pp. 03001 ◽  
Author(s):  
Iskahar ◽  
Suripin ◽  
Isdiyana
Keyword(s):  
Flow Velocity ◽  
Water Level ◽  
Physical Model ◽  
River Estuary ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Sedimentation Pattern ◽  
Cross Sectional ◽  
Channel Angle ◽  
Reservoir Storage

Estuary of the river that leads to the reservoir has characteristics include: relatively flat, there is a change in the increase of wet cross-sectional area and backwater. The backwater will cause the flow velocity to be reduced, so that the grains of sediment with a certain diameter carried by the flow will settle in the estuary of the river. The purpose of this research is to know the distribution and sedimentation pattern at the river estuary that leads to the reservoir with the change of water level in the reservoir storage, so the solution can be found to remove / reduce sediment before entering the reservoir. The method used is the experimental, by making the physical model of the river estuary leading to the reservoir. This study expects a solution to reduce sedimentation, so that sedimentation can be removed / minimized before entering the reservoir. This research tries to apply bypass channel to reduce the sedimentation at the river estuary. Bypass channels can be applied to overcome sedimentation at the river estuary, but in order for the sediment to be removed optimally, it is necessary to modify the mouth of bypass channel and channel angle.

scholarly journals The accuracy of land form presentation in forest road Cross sections

2002 ◽  
pp. 91-99
Author(s):  
Bogdan Stefanovic ◽  
Velimir Aleksic
Keyword(s):  
Cross Sections ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Land Form ◽  
Volume Calculation ◽  
Forest Road ◽  
Earth Material ◽  
Legal Provisions ◽  
Natural Land

Accurate presentation of natural land forms directly affects the accuracy of earth volume calculation, the component of technical documentation of the forest road master project. Consistent to legal provisions, forest road master project is characterised by high accuracy of the planned scope of works compared to the realised scope of works, which should amount to ?3%. The volume of earth material is calculated based on the road cross-sectional area and the distance between the cross sections. The accuracy of the area of cross sections depends on the accuracy of land form presentation Accurate presentation of natural land forms depends on a great number of factors, the most significant of which are the methods of surveying and acquisition of data necessary for land form presentation, preciseness of equipment and instruments used in surveying and acquisition of data, and the method of land form presentation. The accuracy of earth material volume calculation depends on the method of computation, method of presentation of natural and artificial cross sections, and the phase of design. The presentation of natural land form in the width occupied by roadway cross section depends on the validity of the obtained station point elevation (Ht) and the elevations of detailed points (Hi). A relevant factor of the accuracy of cross sectional area, compared to its other elements, is the accuracy of the depth of cut or the height of fill (h) which should agree with the required accuracy, i.e. the adopted tolerance of the earthwork bill of quantities deviation up to 3%.

Genetic Effects on Skeletal Mechanosensitivity in Mice

2002 ◽  
Author(s):  
Charles H. Turner ◽  
Alexander G. Robling
Keyword(s):  
Mechanical Loading ◽  
Cross Sections ◽  
Inbred Mouse ◽  
Cross Sectional Area ◽  
Mouse Strains ◽  
Sectional Area ◽  
Mineral Density ◽  
Bone Apposition ◽  
Cross Sectional ◽  
Total Cross Sectional Area

The accumulation of bone mass during growth can be enhanced by environmental factors such as mechanical loading (exercise) or calcium intake, but 60–70% of the variance in adult bone mineral density (BMD) is explained by heredity. Consequently, understanding the signaling pathways targeted by the genes governing bone accumulation holds perhaps the greatest potential in reducing fracture incidence later in life. Rodent models are particularly useful for studying the genetics of skeletal traits. Of the available inbred mouse strains, three in particular have been studied extensively in skeletal genetics: C57BL/6, DBA/2, and C3H/He. The C57BL/6 strain is characterized by low BMD and large total cross-sectional area (CSA) in the midshaft femur; the C3H/He strain exhibits very high femoral BMD and a smaller femoral CSA than the C57BL/6 mice; and DBA/2 mice have moderately high femoral BMD and a very small midshaft femur CSA. Mechanical loading of the skeleton during growth can substantially enhance periosteal bone apposition, and ultimately produce a diaphyseal cross section with enlarged area. Therefore we hypothesized that the mouse strain with greater femoral cross-sectional area (C57BL/6) might have a genetic predisposition for greater mechanosensitivity than mice with smaller cross sections (C3H/He and DBA/2).

Absence of a growth hormone effect on rat soleus atrophy during a 4-day spaceflight

1993 ◽  
Vol 74 (2) ◽  
pp. 527-531 ◽  
Author(s):  
B. Jiang ◽  
R. R. Roy ◽  
C. Navarro ◽  
V. R. Edgerton
Keyword(s):  
Growth Hormone ◽  
Succinate Dehydrogenase ◽  
Cross Sections ◽  
Fiber Type ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fast Myosin ◽  
Hormone Effect ◽  
Fast Myosin Heavy Chain

The objectives of the present study were to determine the size and enzyme properties of soleus fibers of rats subjected to a 4-day spaceflight (National Aeronautics and Space Administration, STS-41) and the effects of exogenous growth hormone (GH) on the atrophic response of the muscle. Four groups of rats were studied: 1) control (Con), 2) Con plus GH treated (Con + GH), 3) flight (Fl), and 4) F1 plus GH treated (Fl + GH). Cross-sectional area and the activities of succinate dehydrogenase and myofibrillar adenosinetriphosphatase (ATPase) were determined in fibers identified in frozen serial cross sections. Fibers were categorized immunohistochemically as slow, fast, or slow-fast on the basis of their reaction with slow and fast myosin heavy-chain (MHC) monoclonal antibodies. Fibers also were categorized as light or dark on the basis of their staining for ATPase at pH 8.6. After the 4-day flight, mean body weight was significantly decreased compared with control. The absolute and relative (muscle wt/body wt) soleus weights were significantly smaller in the Fl and Fl + GH rats compared with their respective ground-based controls. In both flight groups, the cross-sectional area of the light ATPase fibers was significantly smaller (approximately 30%) than control. Three of 11 flight rats had a higher proportion of fibers expressing both slow and fast MHCs than expected on the basis of the fiber type distribution in the 11 control rats. Mean fiber succinate dehydrogenase and ATPase activities were similar among the four groups.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals REDUCTION PROCESS OF CROSS-SECTIONAL AREA AT RIVER MOUTH

1986 ◽  
Vol 1 (20) ◽  
pp. 113
Author(s):  
Takuzo Shimizu ◽  
Kosuke Kondo ◽  
Ryoichi Kajima
Keyword(s):  
River Mouth ◽  
Reduction Process ◽  
Field Measurements ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Tidal Prism ◽  
Cross Sectional ◽  
Reduction Processes ◽  
The Cross ◽  
Crosssectional Area

Reduction processes of the cross-sectional area at a river mouth were investigated on the basis of numerical simulations and field measurements, in order to predict the possibility of closing of the mouth of the Samegawa River, Fukushima, Japan. As a result, it was found that the decrease in tidal prism, induced by a reduction of the cross-sectional area, had an important effect on the closing of the river mouth. By considering this effect and estimating the sediment transport rate properly, a practical prediction model was successfully established for simulating the reduction processes of the crosssectional area at the river mouth.

scholarly journals The assessment sectional area of stem wood and stocks in experimental trees reclamation Western Donbass plot № 1

2016 ◽  
Vol 45 ◽  
pp. 76-81
Author(s):  
V. M. Zverkovsky ◽  
O. S. Zubkova
Keyword(s):  
Cross Sections ◽  
Linear Growth ◽  
Cross Sectional Area ◽  
Forest Plantations ◽  
Sectional Area ◽  
Cross Sectional ◽  
Stem Wood ◽  
Diameter At Breast Height ◽  
Breast Height

The linear growth of forest plantations of Western Donbass’ recultivating plot №1 were studied. The established cross-sectional the area of trunks and timber reserves experimental trees.Characterized by parameters which are the volume of wood: its height, diameter at breast height and shape of the forming barrel. In diameter at breast height cross sectional area is determined and then the barrel volume is calculated. Cross sections of tree trunks are shaped like a circle or an ellipse. Knowing the volume of logs we calculated reserves of wood for trees experimental plots.The largest reserves of timber and cross-sectional area characterized planting U. pumila – 15,367 m3 and 1,9583 m2, A. platanoides – 13,328 m3 and 2,67 m2, Q. robur – 10,120 m3 and 1,452 m2, J. virginiana – 8,748 m3 and 2,106 m2. The least plantation stocks of wood characterized E. angustifolia – 1,3699 m3 and 0,3693 m2, R. pseudoacacia – 2,9478 m3 and 0,8350 m2, P. rallasiana – 3,1626 m3 and 0,3279 m2.

scholarly journals Nerve ultrasound in the assessment of cross-sectional area in healthy children

2020 ◽  
Vol 10 (2) ◽  
pp. 46-52
Author(s):  
M. A. Bedova ◽  
A. V. Klimkin ◽  
V. B. Voitenkov ◽  
N. V. Skripchenko
Keyword(s):  
Cross Sectional Area ◽  
Normative Values ◽  
Technical Equipment ◽  
Healthy Children ◽  
Sectional Area ◽  
Nerve Ultrasound ◽  
Cross Sectional ◽  
Group 13 ◽  
The Cross ◽  
Crosssectional Area

Introduction. Nerve ultrasound continues to progress due to improved technical equipment and knowledge, but so far not enough research has been done to determine the normative values of the cross-sectional area in children, and the obtained results differ between laboratories and researchers.Aim of the study. To determine the normative values of peripheral nerves» cross-sectional area in children 5–18 years old.Materials and methods. High resolution nerve ultrasound of brachial plexus, median, ulnar, radial, femoral, sciatic, tibial and peroneal nerves was performed in 30 children in real time. Nerve trunks were visualized throughout the limb from both sides. The cross-sectional area of the nerves was measured by a manual tracing method with the rounding of the hypoechogenic contours of the nerve trunk. Nerves’ crosssectional area was measured at distal and proximal sites. The obtained data were statistically processed using Excel and Statistica 10.Results. No bilateral cross-sectional area’s differences were found in children. Boys had significantly thicker nerves compared to girls, older age group (13–17 years old) compared to younger ones. There was a significant correlation between cross-sectional area of the median nerve at the level of the wrist, sciatic nerve and children’ height and weight.Conclusions. The normal values of cross-sectional area in children can be used in the practical work of a neurologists, neurophysiologists and ultrasound technicians.

scholarly journals The assessment sectional area of stem wood and stocks in experimental trees reclamation Western Donbass plot № 1

2016 ◽  
Vol 45 ◽  
pp. 76-81
Author(s):  
V. M. Zverkovsky ◽  
O. S. Zubkova
Keyword(s):  
Cross Sections ◽  
Linear Growth ◽  
Cross Sectional Area ◽  
Forest Plantations ◽  
Sectional Area ◽  
Cross Sectional ◽  
Stem Wood ◽  
Diameter At Breast Height ◽  
Breast Height

The linear growth of forest plantations of Western Donbass’ recultivating plot №1 were studied. The established cross-sectional the area of trunks and timber reserves experimental trees.Characterized by parameters which are the volume of wood: its height, diameter at breast height and shape of the forming barrel. In diameter at breast height cross sectional area is determined and then the barrel volume is calculated. Cross sections of tree trunks are shaped like a circle or an ellipse. Knowing the volume of logs we calculated reserves of wood for trees experimental plots.The largest reserves of timber and cross-sectional area characterized planting U. pumila – 15,367 m3 and 1,9583 m2, A. platanoides – 13,328 m3 and 2,67 m2, Q. robur – 10,120 m3 and 1,452 m2, J. virginiana – 8,748 m3 and 2,106 m2. The least plantation stocks of wood characterized E. angustifolia – 1,3699 m3 and 0,3693 m2, R. pseudoacacia – 2,9478 m3 and 0,8350 m2, P. rallasiana – 3,1626 m3 and 0,3279 m2.

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