Pump Duration Research Articles

Interpretation of a short-duration pumping test in the mixed flow karst system using a three-reservoir model

A new three-reservoir model was proposed to simulate complex groundwater flow in a karst system where a short-duration pumping test was conducted. The pumping test was conducted in the Houzhai underground river basin located in Puding County, Southwest China. Three sinkholes were used as a pumping and observation well network in the pumping test. Water was pumped from one sinkhole located in the local matrix reservoir. The response of hydraulic head to the pumping was observed at the other two sinkholes located in the conduit network reservoir. Marechal and others (Water Resour Res 44:W05401, 2008) used a two-reservoir model to simulate a long-duration pumping test which provided a good match between the observations and calculations. In this study, a three-reservoir model was developed to represent the local matrix, regional matrix, and conduit network. The regional matrix reservoir was treated as the boundary from which the flow system was recharged. This model can better simulate the site’s hydrogeological conditions. The results show that the observed hydraulic heads agree well with the calculated heads in the conduit network [relative root mean square (rRMS) error = 3.32 %] and in the local matrix (rRMS = 8.43 %). The model also calculated the component volumes of groundwater flow, including the exchange among the three reservoirs. The extent of influence of the pumping test was also characterized in the model. Local matrix storage, recharge from the conduit network, and the recharge from the regional matrix account for about 10.46, 61.28 and 28.26 % of the groundwater pumpage, respectively. The appropriate rate and duration of pumping can be estimated using the calibrated model for the water resources management.

Theoretical analysis of the coherence-brightened laser in air

We present a detailed theoretical study of a recent experiment [A. J. Traverso et al., Proc. Natl. Acad. Sci. USA 109, 15185 (2012)] in which a laserlike source is created in air by pumping with a nanosecond pulse. The source generates radiation in the forward and backward directions. The temporal behavior of the emitted pulses is investigated for different pump shapes and durations. Our analysis indicates that the spiky emission is due to quantum coherence via cooperation between atoms of an ensemble, which leads to strong-oscillatory superfluorescence. We show that these cooperative nonadiabatic coherence effects cannot be described by rate equations and instead a full set of the Maxwell-Bloch equations must be used. We consider a range of parameters and study transitions between various regimes. Understanding these coherence-brightened processes in air should lead to improvements in environmental, atmospheric remote sensing and other applications.

Research on High-Intensity Picosecond Pump Laser in Short Pulse Optical Parametric Amplification

A 527 nm pump laser generating 1.7 mJ energy with peak power of more than 0.12 GW is demonstrated. The theoretical simulation result shows that it has 106 gain in the picosecond-pump optical parametric chirped pulse amplification when the pump laser peak power is 0.1 GW and the intensity is more than 5 GW/cm2, and that it can limit the parametric fluorescence in the picosecond time scale of pump duration. The pump laser system adopts a master-oscillator power amplifier, which integrates a more than 30 pJ fiber-based oscillator with a 150 μJ regenerative amplifier and a relay-imaged four-pass diode-pump Nd glass amplifier to generate a 1 Hz top hat spatial beam and about 14 ps temporal Guassian pulse with <2% pulse-to-pulse energy stability. The output energy of the power amplifier is limited to 4 mJ for B-integral concern, and the frequency doubling efficiency can reach 65% with input intensity 10 GW/cm2.

The Development of the Durable Test-Bed of the Hydraulic Pump

An energy recovery method during the durable test is put forward in this essay, and the durable test-bed of the hydraulic pump is developed. The efficiency and accuracy data acquisition is realized by using High-Speed High-Resolution sensor and data collection module. Control automation is come true by using PLC, industrial tablet PC and electric command device. The instrument panel constructed by LabWindows/CVI made the operation more concision, flexible and easy-to-use. This test bed has been put into use for a year and shows that the system can realize duration and efficient test of hydraulic pump easily and reliable.

Exploration of duration of intravenous analgesia pump after gynecological surgery

Objective To evaluate the influence of the duration of patient-controlled intravenous analgesia (PCIA)on pain and gastrointestinal function after gynecological abdominal surgery.Methods Patients who received gynecological abdominal surgery were divided into 3 groups according to using time of PCIA for 24 hours,48 hours,72 hours.There were 30 cases in each group.Pain intensity,gastrointestinal peristalsis time,anal exhaust time,getting out-of-bed time,voluntary micturition time,nausea and vomiting were compared among three groups after stopping PCIA.Results There were no significant differences in VAS score among three groups at each time point.There were no significant differences in voluntary micturition time among three groups.The anal exhaust time,getting out-of-bed time in 24-hour group were earlier than those of the other two groups,the differences were significant; The nausea and vomiting in 24-hour group were lower than the other two groups,the difference was significant.Conclusions The application of PCIA can effectively relieve acute pain 24 hours after surgery,but the effect was not obvious on pain induced by activities after 24 hours.But the side effects induced by analgesia pump(anesthetic)still work,such as vomiting,long duration of discharge,activity inconvenience.So PCIA should be stopped at right time in order to reduce complications and facilitate for recovery of patients after the surgery. Key words: Gynecological abdominal surgery; Pain control; Duration; Adverse reaction

Transitioning Insulin Pump Therapy from the Outpatient to the Inpatient Setting: A Review of 6 Years' Experience with 253 Cases

We reviewed the care of a large cohort of patients with diabetes mellitus on insulin pump therapy who required an inpatient stay. Records were reviewed of patients hospitalized between January 1, 2006, and December 31, 2011. A total of 136 patients using insulin pumps had 253 hospitalizations. Mean (standard deviation) patient age was 55 (16) years, diabetes duration was 29 (15) years, and pump duration was 6 (5) years. Insulin pump therapy was continued in 164 (65%) hospitalizations. Adherence to core process measures improved over time: by 2011, 100% of cases had an endocrinology consultation, 100% had the required insulin pump order set completed, and 94% had documentation of the signed agreement specifying patient responsibilities for continued use of the technology while hospitalized. Documentation of the insulin pump flow sheet also increased but could still be located in only 64% of cases by the end of 2011. Mean glucose was not significantly different among patients who remained on insulin pump therapy compared to those for whom it was discontinued (p > .1), but episodes of severe hyperglycemia (>300 mg/dl) and hypoglycemia (<40 mg/dl) were significantly less common among pump users. No pump site infections, mechanical pump failures, or episodes of diabetic ketoacidosis were observed among patients remaining on therapy. With appropriate patient selection and usage guidelines, most patients using insulin pumps can safely have their therapy transitioned to the inpatient setting. Further study is needed to determine whether this approach can be translated to other hospital settings.

Evaluation and Augmentation of Safe Drinking Water Supply Schemes in Salur Mandal, Vizainagaram District, Andhra Pradesh

Abstract In order to assess the groundwater potentiality and augmentation of water supply schemes, estimation of the safe yield, well loss, formation loss, horse power of pump, depth of pump installation and duration of the pumping are essential. These parameters are estimated either by means of in-situ test or laboratory test. But the applicability of result from the laboratory test has limitations while in-situ tests give real representation of individual well of aquifer. The most common in-situ test is pumping test performed on well, which involves measurement of the fall and rise of water level with respect to time. The changes in water level (drawdown/recovery) and its quality are caused due to pumping of water from the well. Such study was carried out in Salur Mandal, Vizainagaram, Andhra Pradesh, India. In this study, special emphasis was given to the step draw down test at 13 bore wells with maximum 4-steps preferably increasing discharge rate (ranges: 24-293 lpm) for the intensification of safe drinking water supply. Simultaneously 26 groundwater samples were collected separately in 2 steps of the pumping phases from each well and then chemically analyzed. This study indicates that the recommended yields varied from 3600 to 12000 lph. The wells could be used in safely with recommended yield of 5000 lph and pumped for 1 to 2 hrs in 4 to 8 hrs intervals per day. Groundwater is of nearly neutral to mildly acidic and alkaline nature in the pumping stresses. The total dissolved solids (TDS) varied from 142-1050 mg/l, but its values changed from –67 to 240 mg/l during the pumping phases. The concentrations of chloride and sulphate changed from –20 to 30 mg/l and –2 to 8 mg/l, respectively, but about 39% groundwater samples are of constant Cl-concentration. In these pumping phases groundwater is hydrochemically within permissible limit for drinking water supply. This study provides the basis of safe drinking water to tribals, backward class communities and school children.

Alteration ofChironomus plumosusventilation activity and bioirrigation-mediated benthic fluxes by changes in temperature, oxygen concentration, and seasonal variations

Abstract. Burrowing benthic organisms promote water and solute fluxes across the sediment–water interface. Water and solutes penetrate the burrow walls and are transported into/out of the sediment when organisms flush their burrows with overlying water. Few studies have been done to investigate bioirrigation under shifting environmental conditions. We experimentally quantified bioirrigation by Chironomus plumosus larvae in the laboratory at 3 ranges of O2 saturation (low, medium, and high O2 concentrations), 2 temperatures (10 and 20°C), and over different seasons. We measured ventilation activities with O2 and flow-velocity microsensors, flow velocities during pumping periods with color tracers, pumping rates with conductivity exchange experiments, and rates of advective and diffusive water influx into the sediment by influx assays (NaCl was the tracer in both latter experiments). O2 saturations <12% extended pumping durations/h, whereas saturations <3% decreased pumping durations to ∼0. Flow velocities...

Active media based on SiO2 matrices with incorporated molecules of rhodamine dyes

SiO2 matrices with incorporated molecules of Rhodamine 6G and Rhodamine 800 laser dyes were synthesized by the sol–gel method. The spectral properties of the matrices were studied. It was found that the incorporation of Rhodamine 6G molecules into the xerogel network decreased their association. The influence of the molar ratio of water and formamide on the transparency of the samples was studied. Laser emission of SiO2 matrices activated with Rhodamine 800 was obtained in the near infrared spectral range. The values of laser spectrum halfwidth of SiO2 matrices with Rhodamine 6G and Rhodamine 800 are 2–6 nm. A well-defined structure of the laser emission spectra of the matrices at microsecond pumping duration testifies to their relatively high optical quality.

Effects of aligning pulse duration on the degree and the slope of nitrogen field-free alignment

Through theoretical analysis, we show how aligning pulse durations affect the degree and the time-rate slope of nitrogen field-free alignment at a fixed pulse intensity. It is found that both the degree and the slope first increase, then saturate, and finally decrease with the increasing pump duration. The optimal durations for the maximum degree and the maximum slope of the alignment are found to be different. Additionally, they are found to mainly depend on the molecular rotational period, and are affected by the temperature and the aligning pump intensities. The mechanism of molecular alignment is also discussed.

Determination of Storage Coefficients During Pumping and Recovery

An aquifer test is used mostly to determine the storage coefficient and transmissivity. Although residual drawdown data are widely used in estimating the transmissivity of aquifers, the estimation of storage coefficients with recovery data is controversial. Some researchers have proposed methods to estimate storage coefficients with recovery data by assuming equality of storage coefficients for the recovery and pumping periods (S = S'). The aim of this study is to determine storage coefficients without such an assumption, that is, S≠S'. The method is a modified version of Banton-Bangoy's method without considering drawdown data due to pumping. Drawdown is plotted vs. the logarithmic ratio (t'/t) or time since pumping stopped to the duration of pumping and the ratio of storage coefficient during recovery to the storage coefficient from the pumping period (S'/S). The method is verified with one case study and two synthetic examples. Thus, it is possible to determine storage coefficient of pumping period accurately without any data from pumping period by recovery data.

Patient Perceptions of Using the OmniPod System Compared with Conventional Insulin Pumps in Young Adults with Type 1 Diabetes

This study evaluated treatment satisfaction, comfort, and function using the wireless OmniPod™ Insulin Management System (Insulet Corp., Bedford, MA) compared with conventional (infusion set) insulin pumps in young adults with type 1 diabetes. Twenty-nine patients (age, 24.0 ± 5.1 years; diabetes duration, 12.1 ± 5.7 years; insulin pump duration, 6.4 ± 3.1 years; glycated hemoglobin [HbA1c], 8.6 ± 0.7%) participated in a randomized, two-arm open crossover study comparing two consecutive 12-week periods of continuous subcutaneous insulin infusion (CSII): one period using the OmniPod system and the other period using conventional CSII. The main outcome measures were treatment satisfaction (Diabetes Treatment Satisfaction Questionnaire), user evaluation (OmniPod System User Evaluation Questionnaire), and HbA1c levels. Treatment satisfaction at baseline was high, with a mean score of 28.6±4.6 (maximal score, 36) and no significant difference between the two randomized groups. Upon completion of the study period 43% "would switch to OmniPod," 36% were "undecided," and 21% "would not switch pumps." Seventy-six percent preferred the OmniPod automated cannula insertion system, and 56% reported that OmniPod fit better into their lifestyle than conventional CSII. HbA1c levels significantly decreased with both OmniPod and conventional CSII (7.9 ± 0.9% vs. 8.8 ± 0.7% and 8.2 ± 0.9% vs. 8.5 ± 0.5%, respectively; P<0.001 for both groups) after completion of the first treatment arm. The decrease in HbA1c was more marked in the OmniPod group (P=0.044), without additional improvement at the end of the study in either group. The OmniPod system was well received by young adults with type 1 diabetes experienced with conventional CSII.

Using Recovery Data to Extend the Effective Duration of Pumping Tests

Collection of water-level recovery data is a common practice for pumping tests. The resulting data can provide some of the most useful information from the tests, but are rarely used to their full value. van der Kamp (1989) proposed a general method that uses recovery data to extend the effective duration of pumping. The method is straightforward to implement and applicable for simple or complex hydrogeologic settings. The only assumption invoked is that the response remains linear such that the principle of superposition can be applied. No other assumptions about the properties of the aquifer are required. The method can greatly increase the value of pumping tests by extending the effective duration of the tests for as long as significant residual drawdowns are observed.

Optimising the efficiency of pulsed diode pumped Yb:YAG laser amplifiers for ns pulse generation

We present a numerical model of a pulsed, diode-pumped Yb:YAG laser amplifier for the generation of high energy ns-pulses. This model is used to explore how optical-to-optical efficiency depends on factors such as pump duration, pump spectrum, pump intensity, doping concentration, and operating temperature. We put special emphasis on finding ways to achieve high efficiency within the practical limitations imposed by real-world laser systems, such as limited pump brightness and limited damage fluence. We show that a particularly advantageous way of improving efficiency within those constraints is operation at cryogenic temperature. Based on the numerical findings we present a concept for a scalable amplifier based on an end-pumped, cryogenic, gas-cooled multi-slab architecture.

Systematic Evaluation of a Novel Foot-Pump Ureteroscopic Irrigation System

To evaluate forces exerted on a stone with different ureteroscopic irrigation systems. A 3 mm steel simulated stone was welded to a 3F stone basket and inserted into the working channel of a 4.5F Wolf semirigid ureteroscope. The basket shaft was attached to a 50 g load cell. The urterescope was placed in a ureteral model (14F silicon tubing). Simulated blood (McCormick™ Red Dye, 1 dye drop/15 mL H(2)O) was dripped adjacent to the stone at 12 drops/min. Endoirrigation devices were attached to the ureterscope and irrigation was applied at a rate sufficient to maintain visualization of the stone. Force on the stone was measured with the following endoirrigation systems: Boston Scientific™ Single-Action-Pump System (SAP) hand-pump and NuVista Medical™ Flo-Assist(®) foot-pump. No significant difference (p=0.19) in the number of pumps required to maintain a clear endoscopic field was found between the SAP (0.20±0.075/second) and Flo-Assist device (0.25±0.056/second). The pump duration of the Flo-Assist was found to be less (1.12±0.40 seconds) than the SAP (1.35±0.31 seconds), but not significantly different (p=0.24). The average maximum impulse was significantly lower (p=0.0002) for the SAP (8.34×10(-5) Ns) than the Flo-Assist (1.96×10(-3) Ns). Total maximum impulse (2.02×10(-5) Ns) for the SAP and total average impulse (5.51×10(-6) Ns) were found to be lower than the Flo-Assist device. The Flo-Assist had a total maximum impulse of 4.49×10(-4) Ns and total average impulse of 8.85×10(-6) Ns, however, these differences were not statistically significant. The hand-pump (SAP) and foot-pump (Flo-Assist) irrigation devices tested require comparable amounts of pumps for similar durations of time to maintain endoscopic visualization. Overall, the SAP device exerts less average maximum force on the stone than the Flo-Assist device.

Power neodymium-glass amplifier of a repetitively pulsed laser

A neodymium-glass diode-pumped amplifier with a zigzag laser beam propagation through the active medium was elaborated; the amplifier is intended for operation in a repetitively pulsedlaser. An amplifier unit with an aperture of 20 × 25 mm and a ∼40-cm long active medium was put to a test. The energy of pump radiation amounts to 140 J at a wavelength of 806 nm for a pump duration of 550 μs. The energy parameters of the amplifier were experimentally determined: the small-signal gain per pass ∼3.2, the linear gain ∼0.031 cm-1 with a nonuniformity of its distribution over the aperture within 15%, the stored energy of 0.16 — 0.21 J cm-3. The wavefront distortions in the zigzag laser-beam propagation through the active element of the amplifier did not exceed 0.4λ (λ = 0.63 μm is the probing radiation wavelength).

Generation and detection of mode-locked spin coherence in (In,Ga)As/GaAs quantum dots by laser pulses of long duration

Using optical pulses of variable duration up to 80 ps, we report on spin coherence initialization and its subsequent detection in n-type singly-charged quantum dots, subject to a transverse magnetic field, by pump-probe techniques. We demonstrate experimentally and theoretically that the spin coherence generation and readout efficiencies are determined by the ratio of laser pulse duration to spin precession period: An increasing magnetic field suppresses the spin coherence signals for a fixed duration of pump and/or probe pulses, and this suppression occurs for smaller fields the longer the pulse duration is. The reason for suppression is the varying spin orientation due to precession during pulse action.

Optimization of end-pumped, actively Q-switched quasi-III-level lasers

The new model of end-pumped quasi-III-level laser considering transient pumping processes, ground-state-depletion and up-conversion effects was developed. The model consists of two parts: pumping stage and Q-switched part, which can be separated in a case of active Q-switching regime. For pumping stage the semi-analytical model was developed, enabling the calculations for final occupation of upper laser level for given pump power and duration, spatial profile of pump beam, length and dopant level of gain medium. For quasi-stationary inversion, the optimization procedure of Q-switching regime based on Lagrange multiplier technique was developed. The new approach for optimization of CW regime of quasi-three-level lasers was developed to optimize the Q-switched lasers operating with high repetition rates. Both methods of optimizations enable calculation of optimal absorbance of gain medium and output losses for given pump rate.

End-pumped Tm,Ho:NaY(WO4)2 crystal laser at 2.07 μm

We presented an infrared laser output at 2.07 μm with Tm,Ho:NaY(WO4)2 crystal end-pumped by 795 nm laser diode at room temperature. The crystal was grown by the Czochralski method with the concentrations of 5 at % Tm3+ and 1 at % Ho3+. The highest output power was up to 2.7 W corresponding to the crystal temperature being controlled at 283 K. The overall optical conversion efficiency was 5.4% and the slop efficiency was 26%. The output characteristics and the laser threshold affected by the pulse duration and temperature have been studied. We found the stability of the output power was correlative with the crystal temperature heavily. In addition, the wider pulse duration of pump could promote the output power efficiently.

Outpatient-to-Inpatient Transition of Insulin Pump Therapy: Successes and Continuing Challenges

Insulin pump therapy is a complex technology prone to errors when employed in the hospital setting. When patients on insulin pump therapy require hospitalization, practitioners caring for them must decide whether to allow continued pump use. We provide the largest review regarding transitioning insulin pump therapy from the outpatient to inpatient setting. Records of inpatient insulin pump users were retrospectively analyzed at a metropolitan Phoenix hospital between January 2006 and December 2009. Adherence to institutional procedures on insulin pump use was assessed, glycemic control was determined, and adverse events were examined. We examined records on 65 patients with insulin pumps, totaling 125 hospitalizations. Mean (standard deviation) patient age was 55 (17) years, diabetes duration was 27 (14) years, pump duration was 6 (5) years, length of hospital stay was 4.7 (6.3) days, hemoglobin A1c was 7.3 (1.3)%, 85% had type 1 diabetes mellitus, 57% were women, and 97% were white. Admissions involving insulin pumps increased (23 in 2006, 17 in 2007, 40 in 2008, and 45 in 2009). Insulin pump therapy was continued in 83 (66%) hospitalizations. Among these hospitalizations, endocrinology consultations were obtained in 89%, consent agreements were found in 83%, insulin pump order sets were completed in 89%, admission glucose was checked in 100%, and nursing assessments of pump insertion sites were documented in 89%, but bedside insulin pump flow sheets were found in only 55%. Mean glucose of 175 (57) mg/dl was not significantly different than that in hospitalizations where insulin pumps were discontinued [175 (42) mg/dl] or used intermittently [177 (7) mg/dl]. There was one instance of a pump catheter kinking; however, no other adverse events (pump site infections, mechanical pump failure, diabetic ketoacidosis) were observed, and there were no use-related fatalities. Most patients using insulin pumps can safely have their therapy transitioned when hospitalized. A policy on inpatient continuous subcutaneous insulin infusion use can be successfully implemented. Compliance with required procedures can be achieved, although there was room to improve adherence with some process measures. Further study is needed to determine how to optimize glycemic control when pumps are allowed during hospitalization.