Average Flow Volume Research Articles

Evaluation of One-way Traffic Regulation from Average Distance and Flow Volume

Evaluation of One-way Traffic Regulation from Average Distance and Flow Volume

Evaluation of anorectal functions of children with anorectal malformations using fecoflowmetry

Background/Purpose: A simple and objective method evaluating the bowel functions of patients with anorectal anomalies is necessary. The authors applied fecoflowmetry and saline enama test for patients with anorectal anomalies to evaluate the fecodynamics and anorectal motilities in these children. Methods: The bowel functions of 16 patients who underwent repair for anorectal malformations and 5 normal controls were evaluated by saline enema test and fecoflowmetry. The correlations between the clinical scores for the bowel functions and the parameters in fecodynamic studies were investigated. Results: Seven of 16 patients exhibited periodical contractions of the rectum synchronized with relaxations of the anal canal during saline infusion as did the controls and had significantly higher clinical scores than the other patients. Two patients with severe chronic constipation lacked rectal contractions. Among the fecoflowmetric parameters, the maximum flow, average flow, and tolerable volume of saline infused into the rectum were significantly lower in the patients with low clinical scores than those of the controls. The maximal squeeze pressure and resting anal pressure were not significantly different between the patients and controls. Conclusion: Fecodynamic studies, such as fecoflowmetry and saline enema test, help in obtaining clinical indicators for the bowel functions of patients with anorectal anomalies. J Pediatr Surg 37:623-628. Copyright 2002, Elsevier Science (USA). All rights reserved.

Vertex corrections in the theory of foamdrainage

The experimental results of Koehler and co-workers have indicatedthat vertices (nodes) can in some cases play a dominant role in thedissipative process that controls foam drainage. We presentcalculations of numerical constants that can express the effect ofthe vertices, in a first approximation. Two limiting cases aretreated: Poiseuille flow, and free-boundary flow (in the sense thatthe stress at the surface of the Plateau borders is everywherezero). Consequences for the relationship between average flowvelocity and volume flow rate in steady drainage are indicated.

Measuring pulsating flow with ultrasound

This paper continues the research presented at the IMEKO XV World Congress in Osaka/JP. It gives deeper insights into the topic of measuring the average volume flow with ultrasound based flow meters in a pulsating fluid. Pulsations are very common in industrial applications so that flow meters have to cope with this kind of disturbances. Especially ultrasonic flow meters are expected to react very sensitively to this effect because they measure any kind of pressure changes. By generating pulsations with a rotating paddle the following article will give impressions about possible influences and the maximum operating range of a cross-correlation and a vortex frequency meter. In addition to the IMEKO basic interpretations are proved by new theoretical considerations.

Relationship of blood pressure and pump flow in an implantable centrifugal blood pump during hypertension.

The purpose of this study was to evaluate the real time relationship between pump flow and pump differential pressure (D-P) during experimentally induced hypertension (HT). Two calves (80 and 68 kg) were implanted with the EVA-HEART centrifugal blood pump (SunMedical Technology Research Corp., Nagano, Japan) under general anesthesia. Blood pressure (BP) in diastole was increased to 100 mm Hg by norepinephrine to simulate HT. Pump flow, D-P, ECG, and BP were measured at pump speeds of 1,800, 2,100, and 2,300 rpm. All data were separated into systole and diastole, and pump flow during HT was compared with normotensive (NT) conditions at respective pump speeds. Diastolic BP was increased to 99.3+/-4.1 mm Hg from 66.5+/-4.4 mm Hg (p<0.01). D-P in systole was under 40 mm Hg (range of change was 10 to 40 mm Hg) even during HT. During NT, the average systolic pump flow volume was 60% of the total pump flow. However, during HT, the average systolic pump flow was 100% of total pump flow volume, although the pump flow volume in systole during HT decreased (33.1+/-5.7 vs. 25.9+/-4.0 ml/systole, p<0.01). In diastole, the average flow volume through the pump was 19.6+/-6.9 ml/diastole during NT and -2.2+/-11.1 ml/diastole during HT (p<0.01). The change in pump flow volume due to HT, in diastole, was greater than the change in pump flow in systole at each pump speed (p<0.001). This study suggests that the decrease of mean pump flow during HT is mainly due to the decrease of the diastolic pump flow and, to a much lesser degree, systolic pump flow.

Revisiting the Advection-Dispersion Model Testing an Alternative

ABSTRACTSome of the basic assumptions of the Advection-Dispersion model, AD-model, are revisited. That model assumes a continuous mixing along the flowpath similar to Fickian diffusion. This implies that there is a constant dispersion length irrespective of observation distance. This is contrary to most field observations. The properties of an alternative model based on the assumption that individual water packages can retain their identity over long distances are investigated. The latter model is called the Multi-Channel model, MCh-model. Inherent in the latter model is that if the waters in the different pathways are collected and mixed, the “dispersion length” is proportional to observation distance.Using diffusion theory it is investigated over which distances or contact times, adjacent water packages will keep their identity. It is found that for a contact time of 10 hours, two streams, each wider than 6 mm, that flow side by side, will not have lost their identity. For 1000 hours contact time the minimum width is 6 cm.The MCh and AD-models were found to have very similar Residence Time Distributions, RTD, for Peclet numbers larger than 3. A generalized relation between flowrate and residence time is developed, including the so-called cubic law and constant aperture assumptions. Using the generalized relation, surprisingly it is found that for a system that has the same average flow volume and average flowrate the form of the RTD curves are the same irrespective of the form of the relation.Both models are also compared for a system where there is strong interaction of the solute with the rock matrix. In this case it is assumed that the solute can diffuse into and out of the fracture walls and also to sorb on the micro-fractures of the matrix. The so-called Flow Wetted Surface, FWS, between the flowing water in the fracture and the rock is a key entity in such systems. It is found that the AD-model predicts much later arrivals and lower concentrations than does the MCh-model for strongly sorbing solutes.The conditions are explored for when in-filling particles in the fracture will not be equilibrated but will act as if there was seemingly a much larger FWS. It is found that for strongly sorbing tracers, relatively small particles can act in this way for systems and conditions that are typical of many tracer tests.Conditions for when uptake into stagnant zones of water in the fracture itself could be important are also explored. It is found that this mechanism can be quite important in fractures with large apertures.The assumption that the tracer residence time found by cautiously injecting a small stream of traced water represents the residence time in the whole fracture is explored. It is found that the traced stream can potentially sample a much larger fraction of the fracture than the ratio between the traced flowrate and the total pumped flowrate. In some recent field experiments the visually observed fracture apertures indicate that this may well be the case and possibly a more than two times larger fraction of the fracture is sampled than the flow rate ratio would indicate. This of course has an impact on the Flow Wetted Surface the traced stream contacts.The MCh-model was used to simulate some recent tracer tests in a single fracture at the ÄSPÖ Hard rock laboratory in Sweden. Non-sorbing tracers, HTO and Uranin were used to determine the mean residence time and its variance. Laboratory data on diffusion and sorption properties were used to “predict” the RTD of the sorbing tracers. It was found that diffusion into stagnant zones of water in the fracture could be 10 to 300 times larger than the uptake into the rock matrix in these experiments. This was also found to give good agreement with the experiments for the non sorbing and weakly sorbing tracers. For the strongly sorbing tracers it was necessary to invoke a 2-6 times stronger interaction with the material in the stagnant zones than expected. Some reasons for such behavior are explored.The transmissivity variance found from the five bore-holes intersecting the fracture where the tracer experiments were made were used to determine the exponent in the generalized relation between aperture and flowrate. The equivalent to the exponent 3 in the cubic law was found to be 1.3-1.6.

Influence of Magnetic Field on the Peristaltic Flow of a Viscous Fluid through a Finite‐Length Cylindrical Tube

The paper presents an analytical investigation of the peristaltic transport of a viscous fluid under the influence of a magnetic field through a tube of finite length in a dimensionless form. The expressions of pressure gradient, volume flow rate, average volume flow rate and local wall shear stress have been obtained. The effects of the transverse magnetic field and electrical conductivity (i.e. the Hartmann number) on the mechanical efficiency of a peristaltic pump have also been studied. The reflux phenomenon is also investigated. It is concluded, on the basis of the pressure distribution along the tubular length and pumping efficiency, that if the transverse magnetic field and the electric conductivity increase, the pumping machinery exerts more pressure for pushing the fluid forward. There is a linear relation between the averaged flow rate and the pressure applied across one wavelength that can restrain the flow due to peristalsis. It is found that there is a particular value of the averaged flow rate corresponding to a particular pressure that does not depend on the Hartmann number. Naming these values ‘critical values’, it is concluded that the pressure required for checking the flow increases with the Hartmann number above the critical value and decreases with it below the critical value. It is also inferred that magneto‐hydrodynamic parameters make the fluid more prone to flow reversal. The conclusion applied to oesophageal swallowing reveals that normal water is easier to swallow than saline water. The latter is more prone to flow reversal. A significant difference between the propagation of the integral and non‐integral number of waves along the tube is that pressure peaks are identical in the former and different in the latter cases.

Portal venous volume flow: in vivo measurement by time-domain color-velocity imaging

The portal venous velocity and flow volume in 39 patients (16 with liver cirrhosis, 11 with chronic hepatitis, 12 without liver disease) were measured using both color velocity imaging quantification (CVI-Q) and conventional Doppler flowmetry. The average portal venous velocity and flow volume values obtained using the two methods were similar. The correlation coefficients for the paired measurements show positive correlations (velocity: 0.73, p < 0.0001; volume: 0.50, p = 0.001). However, the coefficients of variation between the two methods were not good (velocity: 14.9%, volume: 26.4%). In conventional Doppler flowmetry, the mean velocity to maximum velocity ratio (Vmean:Vmax) is assumed to be constant (Vmean:Vmax = 0.57 in this study). However, the Vmean:Vmax ratios calculated from the flow profile in CVI-Q were 0.67 ± 0.13 in the patients with liver cirrhosis, 0.58 ± 0.13 in the patients with chronic hepatitis, and 0.53 ± 0.08 in the patients without liver disease. Therefore, a measurement method that takes the blood flow profile into account, such as CVI-Q, might be useful for the quantitative measurement of the portal venous velocity and volume.

Acoustic chemometrics for fluid flow quantifications—II: a small constriction will go a long way

A new approach for non-invasive quantitative measurement of volume flow rate, multicomponent mixture concentrations as well as density and other physico-chemical intensive parameters of liquid mixtures flowing in pipelines is presented, based on novel application extensions of the well-known orifice plate principle (extensively used for flow measurement in pipes). By deliberately transgressing the conventional usage limits, the orifice plate configuration may now also be used for a range of new measurement types, all based on acoustic sensor technology. R&D has been carried out since 1987 by Sensorteknikk A/S and since 1994 in collaboration with ACRG. The acoustic chemometrics concept is characterized by easy ‘clamp-on’ deployment of acoustic sensors (primarily accelerometers), followed by an essential, integrated signal analysis/multivariate calibration data modelling, well known from chemometrics. The signal analysis step in this endeavour is often critical although rarely outside conventional electrical engineering scopes. We present three fluid/fluid or fluid/solid mixture application type cases: (1) trace oil-in-water determination (representing one-analyte systems); (2) jet-fuel/glycol mixture determination (representing two-analyte systems); (3) paper-pulp constituent(s) determination (representing analyte–interferents systems). We also describe extension studies of these first quantitative acoustic chemometrics forays, e.g. for alternative measurement of (conventional) flow velocities of both fluid/fluid and fluid/solid (slurries) systems (average volume flow rate of heterogeneous multiphase systems), for flow regime characterization and for measurement of the effective in-line density of (fluid/fluid and fluid/solid) mixtures. There would appear to be a vast potential for technological and industrial applications of this new type of acoustic chemometric process and product characterization/monitoring. Copyright © 1999 John Wiley & Sons, Ltd.

Acoustic chemometrics for fluid flow quantifications - II: a small constriction will go a long way

A new approach for non-invasive quantitative measurement of volume flow rate, multicomponent mixture concentrations as well as density and other physico-chemical intensive parameters of liquid mixtures flowing in pipelines is presented, based on novel application extensions of the well-known orifice plate principle (extensively used for flow measurement in pipes). By deliberately transgressing the conventional usage limits, the orifice plate configuration may now also be used for a range of new measurement types, all based on acoustic sensor technology. R&D has been carried out since 1987 by Sensorteknikk A/S and since 1994 in collaboration with ACRG. The acoustic chemometrics concept is characterized by easy ‘clamp-on’ deployment of acoustic sensors (primarily accelerometers), followed by an essential, integrated signal analysis/multivariate calibration data modelling, well known from chemometrics. The signal analysis step in this endeavour is often critical although rarely outside conventional electrical engineering scopes. We present three fluid/fluid or fluid/solid mixture application type cases: (1) trace oil-in-water determination (representing one-analyte systems); (2) jet-fuel/glycol mixture determination (representing two-analyte systems); (3) paper-pulp constituent(s) determination (representing analyte–interferents systems). We also describe extension studies of these first quantitative acoustic chemometrics forays, e.g. for alternative measurement of (conventional) flow velocities of both fluid/fluid and fluid/solid (slurries) systems (average volume flow rate of heterogeneous multiphase systems), for flow regime characterization and for measurement of the effective in-line density of (fluid/fluid and fluid/solid) mixtures. There would appear to be a vast potential for technological and industrial applications of this new type of acoustic chemometric process and product characterization/monitoring. Copyright © 1999 John Wiley & Sons, Ltd.

Relief by botulinum toxin of voiding dysfunction due to prostatitis

Obstructive urinary symptoms due to chronic non-bacterial prostatitis are due to incomplete relaxation of the bladder neck or inappropriate contraction of the external urethral sphincter during voiding. Patients may respond to adrenergic blocking drugs; if effective, treatment may need to be continued indefinitely. Botulinum toxin has been used to weaken striated and smooth muscles. Toxin injections into the external urethral sphincter to relieve urethral obstruction were described by Dykstra and Sidi. Apart from treatment of detrusor-sphincter dyssynergia, we have found no reports in the literature on the treatment of voiding dysfunction in non-bacterial prostatitis. Four consecutive men (mean age 30·7 [SD 5·7] years) with chronic non-bacterial prostatitis and poor bladder emptying because of spastic external urethral sphincter (mean duration of symptoms 18 [3] months), who failed to respond to tamsulosin 0·4 mg once daily for more than 4 months were enrolled. All the patients were examined, had uroflowmetric studies to assess times of urinary flow (TQ) and maximum urinary flow (TQmax), maximum flow (Qmax), average flow (Qave), and total urinary volume (Vcomp), and had anorectal manometry at rest (RT) and after maximum contraction (MC). An increased value of TQ and TQmax with a normal value of Qmax was taken to be indicative of incomplete relaxation of bladder neck. 1, 4, and 8 weeks after treatment, patients underwent the same assessments. With the patient lying on his left side, a 26-gauge monopolar needle electrode was inserted in the perineum in the anterior midline, about 1·5–2·0 cm from the anus and directed toward the prostatic apex, without sedation or local anaesthesia. 30 U of type A botulinum toxin were injected. No local complications or systemic side-effects were seen. Within 1 week of injection all patients had a striking improvement in their voiding; none complained of urinary incontinence. At 4 weeks, three patients showed a continuing improvement. At 8 weeks, the same three patients were satisfied with the therapy and none of them complained of urinary incontinence. The patients were followed up for a mean of 12 months. No relapse occurred in the three patients who improved. 6 weeks after treatment, the fourth patient reported worsening voiding. He was also depressed and required fluoxetine. He was re-treated with 50 U of botulinum toxin and the urinary symptoms improved. Uroflowmetric study showed a decrease in TQ and TQmax values at 1, 4, and 8 weeks compared with baseline values (table). Other variables were not changed.

Efficacy and Acceptability of Tadenan®(Pygeum africanum Extract) in the Treatment of Benign Prostatic Hyperplasia (BPH): A Multicentre Trial in Central Europe

SummaryPygeum africanum extract is available as Tadenan ® in many countries, including those in central and eastern Europe, for the treatment of mild to moderate BPH. Its efficacy and acceptability have been demonstrated in numerous open and placebo-controlled studies in large populations. The present open three-centre efficacy and safety study was conducted according to common protocol at urology clinics in the Czech and Slovak Republics and in Poland, in order to confirm the therapeutic profile o/Pygeum africanum in conditions of daily practice, using International Prostate Symptom Score (IPSS) andflowmetry assessments.Men aged 50-75 years and in compliance with the selection criteria (including IPSS ≥ 12, quality of life (QoL) score ≥ 3, and maximum urinary flow ≤ 15 mils) were first examined then recalled after two weeks during which no treatment was provided (washout and check of stability). If still compliant, they were entered at this point into a two-month period of treatment with Pygeum africanum extract 50 mg twice daily. There followed a further one-month period without treatment, the objective being to evaluate the persistence of any effects observed during the previous two months of Pygeum africanum administration.The primary efficacy parameter investigated was IPSS; the other efficacy parameters were QoL, nocturnal frequency, maximum urinary flow, average urinary flow, post-voiding residual volume and prostatic volume, after one and two months of Pygeum africanum treatment and one month after stopping treatment. A total of 85 patients were evenly distributed between the three centres and completed the entire study. At inclusion their mean IPSS was 16.17, QoL was 3.60 and nocturia was 2.6 times per night.The changes in subjective scores, IPSS and QoL after the two-month treatment period were highly statistically significant with mean improvements of 40% and 31 %, respectively. Nocturnal frequency was reduced by 32% and the mean reduction was again highly statistically significant. Mean maximum urinary flow, average urinary flow and urine volume were also statistically significantly improved, but the modest improvement in post-voiding volume did not reach statistical significance. The improvements, which exceeded those observed with placebo in earlier studies, were maintained after one month without treatment indicating an interesting persistence of clinically useful activity. Prostatic volume and quality of sexual life remained unchanged throughout. No treatment-related adverse effects were observed.In conclusion, under conditions of daily practice, Pygeum africanum extract induces significant improvement in IPSS and uroflowmetry parameters. These positive effects are accompanied by a very satisfactory safety profile with the overall result of a substantial improvement in QoL.

Upper extremity blood flow in collegiate and high school baseball pitchers A preliminary report.

The arterial and venous volume blood flow in the dominant and nondominant upper extremities of five male pitchers, ages 16 to 21, was measured using color flow duplex ultrasound. Blood-flow measurements were obtained at baseline, after warm-up, and after each sequence of 20 pitches until 100 pitches were thrown. Blood flow was additionally determined 1 hour after the last pitch. The velocity of each pitch was recorded with a speed gun. Anthropomorphic measurements of the upper extremity were obtained at baseline and immediately after Pitch 100 using a standard measuring tape. The highest average arterial volume flow in the pitching arm occurred after 40 pitches, reaching a peak of 549 ml/min (56% increase from baseline). Thereafter, the average arterial blood flow steadily declined, reaching an average of 402 ml/min after the 100th pitch (14% increase from baseline). In contrast, the arterial blood flow in the nonpitching arm increased only slightly from baseline, reaching a maximal volume flow of 448 ml/min immediately after the warm-up period (10% increase from baseline). The volume flow then persistently fell to a level 30% below baseline after the 100th pitch. Although this small pilot study does not demonstrate causation between a decline in pitching performance and arterial blood flow, it suggests arterial flow in the dominant extremity falls as the pitch count increases.

Systolic flow limitation in stenotic lower-extremity vein grafts

Our purpose was to investigate the hemodynamic theory that the blood flow rate through a stenotic arterial graft is limited by the onset of turbulence, which acts as a barrier at peak systole against further increases in systolic flow. We used duplex ultrasonography to examine 25 stenotic infrainguinal vein grafts. Theory predicts that the flow limitation occurs at peak systole at a stenotic velocity greater than 250 cm/sec, which corresponds to a residual stenotic lumenal diameter of 0.36 cm (Reynolds No. 2000). These numbers are based on the assumption that the 68 ml/min blood flow is supplied by the femoropopliteal graft to the resting lower leg only during systole. When the lumen is smaller than 0.36, peak systolic velocity (PSV) must exceed 250 cm/sec. The increased velocity results in poststenotic turbulence. This turbulent condition restricts the average graft systolic flow to less than the 68 ml/min required by the lower leg, so diastolic flow is needed to make up the deficit. Twenty vein grafts with PSVs of 250 cm/sec or greater had end-diastolic velocities of 50 cm/sec or greater as predicted; three grafts with PSVs of 256 to 300 cm/sec and two grafts with PSVs of less than 250 cm/sec had no forward diastolic flow. The onset of turbulence in a stenotic vein graft supplying the lower leg occurs at a PSV of 250 cm/sec or greater. The appearance of diastolic flow maintains the average graft volume flow.

Analysis of the Local Volume Flow Rate of Polymers During Injection Molding

Abstract Amorphous and crystalline polymers were injected into different molds of disks, with different applied injection rates. The pressures and local volume flow rates were measured for different injection molding conditions. These measures show a difference between the average volume flow rate measured during the total filling time and the nominal applied volume flow rate. Moreover the local volume flow rate at the polymer front increases between the mold entrance and the end of the cavity. Effects of different parameters of the process (polymer, geometry of the part, injection molding conditions) on the evolution of these volume flow rates were examined. Interpretation of the observed phenomena neads to take into account the effect of two characteristics of the polymers which are generally neglected: the compressibility and the associated bulk viscosity.

Phase-contrast echo-planar MR imaging: real-time quantification of flow and velocity patterns in the thoracic vessels induced by Valsalva's maneuver.

Although the clinical manifestations of Valsalva's maneuver are well known, the associated hemodynamic changes in the great vessels have not been extensively studied and documented. In each of six healthy subjects, we evaluated three "quasi-steady-state" phases of Valsalva's maneuver: (1) during normal respiration, (2) during late strain, and (3) 4 seconds after strain release. Continuous flow, velocity, and cross-sectional area measurements were obtained in the superior vena cava, pulmonary trunk, and thoracic aorta with single-shot echo-planar MR imaging (EPI) with velocity-encoded gradients, which provided 256 images in 5 seconds, yielding 26 velocity-encoded images per second. In the superior vena cava, Valsalva's maneuver induced an 11% decrease in average flow volume, a 102% increase in peak flow velocity, a 156% increase in the time velocity integral, and a 37% decrease in cross-sectional area. MR velocity measurements agreed with echocardiographic data and supplied additional information on flow and morphology. EPI showed a reduction in venous return during Valsalva's maneuver by simultaneously assessing flow, velocity, and vessel morphology; this technique appears to be useful in the analysis of flow dynamics of the great vessels.

Benzyldimethylamine(BDMA) and dimethylaminoethanol as the catalysts of choice for epoxy resin embedding media

INTRODUCTION: By long held tradition, many epoxy resin embedding media are catalyzed with 2,4,6-Tri(dimethylaminomethyl)phenol (DMP-30). Embedding media polymerized in this manner are widely-used and produce acceptable results, nevertheless they show high viscosity, a rapid loss in fluidity, and ultimately a shortened useful pot-life necessary for complete specimen infiltration. Perhaps using less viscous catalysts, such as Benzyldimethylamine (BDMA) or Dimethylaminoethanol (DMAE), would yield embedding media with lowered viscosity and prolonged fluidity, both very important characteristics that would ensure complete infiltration and strengthening of tissues subsequent to microtomy and ultrastructural study.MATERIALS &amp; METHODS: The amine catalysts BDMA, DMAE, and DMP-30 were tested for Average Flow Time (AFT) and Volume Flow Rate (VFR) by recording the time necessary for 9 ml of each component to flow from a vertically oriented viscosimeter. Viscosity (cp), which is a relative measure of fluidity and a real correlate of AFT/VFR, then was calculated with the Hagen-Poiseville relation for laminar flow as applied to fluids. Embed 812 and LX112 media were prepared and catalyzed either with BDMA, DMAE, or DMP-30 and their AFT, VFR, and cp similarly determined @ 5, 30, and 60 minute intervals after initial mixing.

Interobserver variability of dialysis shunt flow measurements using color coated duplex sonography

A prospective study extending over 4 months was carried out in which 142 shunt volume flow measurements were performed on 43 patients; two up to four operators with varying degrees of experience took part. Flow volumes varied between 51 and 2409 ml/min with an average blood flow volume of 521 ml/min. Comparison of measurements of individual operators showed errors of between 0.5 and 19.8%. Average error was calculated as 11.3%. Shunt flow measurements by colour Doppler sonography provide an easily appreciated and reproducible method for quantifying changes in shunt flow.

Duplex sonography of abdominal vessels

Duplex sonography is a non-invasive procedure which permits the determination of flow velocity and direction in visceral vessels. Results in 50 normals have shown that small arteries can be evaluated in about 50% of cases. The portal venous system can be demonstrated in all cases; average flow velocity and volume is 15.2 +/- 2.8 cm/s and 694 +/- 230 ml/min, corresponding with the values obtained by invasive methods. Clinical application for duplex examinations can be found in portal hypertension, varices, thromboses, aneurysms and transplant kidneys.

EFFECT OF SURFACE MINING ON STORM FLOW AND PEAK FLOW FROM SIX SMALL BASINS IN EASTERN KENTUCKY1

ABSTRACT: Hydrologic records from six small Eastern Kentucky watersheds were analyzed to determine the effect of surface mining on storm flows and peak flows. Average storm flow volumes were not changed by surface mining, whereas average peak flows were increased 36 percent. Peak flow increases were only in the summer. Smaller peak flows are doubled; moderate ones are increased by about a third; peak flows around 100 csm seem to be largely unaffected; and the larger peak flows may have been reduced by surface mining. The maximum annual storm flows, usually in winter or spring, appeared slightly reduced. No time trend in either storm flows or peak flows could be detected in five years of postmining record. Surface mining is not a serious floodwater discharge problem.