Preset Rate Research Articles

Aircraft Calibration for Pest Eradication Operations Using Pesticides Formulated as Solid Baits

The objective of any aerial (or ground-based) pesticide application is to achieve a biological objective while minimizing costs and environmental and social impacts. A requirement for achieving this objective is to spread the material at a preset rate and at an acceptable uniformity while minimizing the total aircraft travel distance and operation time, which equates to cost. The aircraft calibration procedure is an important step in developing operational parameters to meet these criteria. Many factors influence the variability of pesticide deposition during a calibration procedure. However, the calibration process is actually designed to minimize much of this variation. Therefore, pesticide deposit variation during an operation is likely to be significantly higher than expected from the calibration process. The consequence of variable deposition is overdosing and underdosing. Underdosing is a particular concern for a pest eradication operation because survivors could re-establish the population. A new modeling approach proposed for aircraft calibration more accurately quantifies the level of deposit variability likely to result from different operational specifications. Using an operational mosquito eradication program as a case study, the new analysis highlighted that, for this scenario, the proportion of the target area underdosed was not extremely sensitive to either the sampling area size or the lane separation. Nevertheless, reducing the lane separation to 18 m from the current specification of 20 m reduced the predicted underdosed area by about 2% to 3% depending on the target area size (sample area). Without further analysis, the trade-off between a 2% to 3% reduction in underdosing (i.e., the probability of eradication) versus an increased operational cost from increased flying time is a subjective decision. A significant result was the very high sensitivity of the underdosed area to the standard deviation of wind speed. This result means there is a large advantage in maintaining a low wind speed during the application.

Impact of dehydration on a full body resistance exercise protocol

This study examined effects of dehydration on a full body resistance exercise workout. Ten males completed two trials: heat exposed (with 100% fluid replacement) (HE) and dehydration (approximately 3% body mass loss with no fluid replacement) (DEHY) achieved via hot water bath (approximately 39 degrees C). Following HE and DEHY, participants performed three sets to failure (using predetermined 12 repetition maximum) of bench press, lat pull down, overhead press, barbell curl, triceps press, and leg press with a 2-min recovery between each set and 2 min between exercises. A paired t test showed total repetitions (all sets combined) were significantly lower for DEHY: (144.1 +/- 26.6 repetitions) versus HE: (169.4 +/- 29.1 repetitions). ANOVAs showed significantly lower repetitions (approximately 1-2 repetitions on average) per exercise for DEHY versus HE (all exercises). Pre-set rate of perceived exertion (RPE) and pre-set heart rate (HR) were significantly higher [approximately 0.6-1.1 units on average in triceps press, leg press, and approached significance in lat pull down (P = 0.14) and approximately 6-13 b min(-1) on average in bench press, lat pull down, triceps press, and approached significance for overhead press (P = 0.10)] in DEHY versus HE. Session RPE difference approached significance (DEHY: 8.6 +/- 1.9, HE: 7.4 +/- 2.3) (P = 0.12). Recovery HR was significantly higher for DEHY (116 +/- 15 b min(-1)) versus HE (105 +/- 13 b min(-1)). Dehydration (approximately 3%) impaired resistance exercise performance, decreased repetitions, increased perceived exertion, and hindered HR recovery. Results highlight the importance of adequate hydration during full body resistance exercise sessions.

Two Algorithms of Power Loading for MCM System in Nakagami Fading Channel

We consider two non-iterative algorithms of adaptive power loading for multicarrier modulation (MCM) system, The first one minimizes the average power of the system transmitter and ensures the preset average bit-error rate, while the second reduces the average transmitting power subject to the given values of demanded bit-error rate and of the outage probability. The algorithms may be used for power-efficient management of the up-link in cellular communication, where mobile terminals use rechargeable batteries, or of the downlink in satellite communication with solar power source of a transponder. We present performance analysis of the adaptive MCM systems supported by computer simulation for the case of the m-Nakagami fading and additive white Gaussian noise in the forward and backward channels. Evaluation of the power gain of the proposed strategies and its comparison with uniform power loading shows that the gain depends on the fading depth and average signal to noise ratio in the system sub-channels.

Moving-gimbal Effects Compensation of Double Gimbal Magnetically Suspended Control Moment Gyroscope Based on Compound Control

Double gimbal magnetically suspended control moment gyroscope (DGMSCMG) is made up of magnetically suspended high-speed rotor system,inner and outer gimbal rate-servo system,and serves as novel attitude control actuator of spacecraft. Owing to nonlinearity and strong couple of three subsystems,rotor axis run-out will grow significantly to reduce system stability severely and response speed goes lower when gimbal revolving,which is called moving-gimbal effects. The effects influence DGMSCMG function severely and must be depressed. Based on DGMSCMG dynamic model set up in this paper and couple mechanism analysis,a novel compensation method based on compound control is presented,which introduces feedback of gyro item and feedforward of preset gimbal rate to depress additional displacement of rotor and raise response speed of gimbal,and system global stability is analyzed. Results of simulation and experiment show that the proposed method can depress moving-gimbal effects effectively to satisfy DGMSCMG requirement besides remaining stability.

Thermoanalytical studies of silver and lead jarosites and their solid solutions

Dynamic and controlled rate thermal analysis has been used to characterise synthesised jarosites of formula [M(Fe)3(SO4)2(OH)6] where M is Pb, Ag or Pb–Ag mixtures. Thermal decomposition occurs in a series of steps. (a) dehydration, (b) well defined dehydroxylation and (c) desulphation. CRTA offers a better resolution and a more detailed interpretation of water formation processes via approaching equilibrium conditions of decomposition through the elimination of the slow transfer of heat to the sample as a controlling parameter on the process of decomposition. Constant-rate decomposition processes of water formation reveal the subtle nature of dehydration and dehydroxylation. CRTA offers a better resolution and a more detailed interpretation of the decomposition processes via approaching equilibrium conditions of decomposition through the elimination of the slow transfer of heat to the sample as a controlling parameter on the process of decomposition. Constant-rate decomposition processes of non-isothermal nature reveal separation of the dehydroxylation steps, since in these cases a higher energy (higher temperature) is needed to drive out gaseous decomposition products through a decreasing space at a constant, pre-set rate.

Capacity planning of serial and batch machines with capability constraints for wafer fabrication plants

Capacity planning is crucial to the investment and performance of wafer fabs. This research proposes a practical procedure to calculate the required number of machines with serial and batch processing characteristics, respectively. Several formulae are first presented. Five heuristic algorithms are then proposed to determine the lower bound, the upper bound, and the near-optimal of the number of machines of the type with capability constraint. Data from real foundry fabs are used in a case study to determine the required number of 64 types of equipment and to evaluate the performance of the proposed procedure. The algorithm using the best ratio of production efficiency and equipment cost to select the machine type with capability constraint results in the least required number of machines, the highest machine utilisation, and the lowest equipment investment. An AutoSched AP simulation model is used to evaluate if a wafer fab using the calculated number of machines of each type can result in a preset monthly output rate. Simulation results indicate that the proposed procedure can quickly and accurately calculate the required number of machines leading to the required monthly production target. Fab managers can use this tool to conduct what-if analysis for equipment investment alternatives.

Adaptive Mode-Suppression and Disturbance-Rejection Scheme With Application to Disk Drives

The goal of a track-following controller for a disk drive is to maintain as close to perfect tracking as possible. Better tracking allows for more data to be stored on a single disk. There are several factors which make this control problem difficult, such as high-frequency resonant modes, unknown disturbances, and a preset sampling rate. The resonant modes of a disk drive are often uncertain and vary between units and can also lie near or beyond the Nyquist frequency. Suppressing these modes can be difficult. However, a multirate adaptive notch filter and adaptive bandwidth controller is proposed to suppress these resonant modes. A robust online estimator that estimates the mode frequencies is used to allow the multirate adaptive notch filter to track the disk drive's modes. By adding a multirate scheme to the adaptive notch filter, it can suppress modes at higher frequencies, which are close to or beyond the Nyquist frequency of the preset sampling rate. As the multirate adaptive notch filter tracks the plant mode frequencies, the adaptive bandwidth controller ensures that stability and performance requirements are satisfied by using the online estimate of the mode frequencies. An adaptive disturbance rejector is added to the adaptive mode-suppression scheme and broken into two parts: a part to suppress the repeatable runout and another to attenuate the residual disturbance by using a neural model. Both parts are adapted online and combined with the mode-suppression scheme to ensure good disturbance rejection even in the presence of unknown or changing resonant modes. Simulation results with a hard disk drive as the application are included and show that the adaptive mode-suppression scheme is able to maintain stability and better performance than a nonadaptive counterpart for an uncertain resonant-mode frequency. When combined with the adaptive disturbance-rejection scheme, stability is maintained and an improvement of as much as 14.3% in 3sigma is seen. This improvement in tracking can allow for data to be stored more densely on a single disk, providing larger storage media for the same size of disk drive.

Quasi steady state growth of Lactococcus lactis in glucose-limited acceleration stat (A-stat) cultures

Quasi steady state growth of Lactococcus lactis IL 1403 was studied in glucose-limited A-stat cultivation experiments with acceleration rates (a) from 0.003 to 0.06 h(-2) after initial stabilization of the cultures in chemostat at D = 0.2-0.3 h(-1). It was shown that the high limit of quasi steady state growth rate depended on the acceleration rate used-at an acceleration rate 0.003 h(-2) the quasi steady state growth was observed until mu (crit) = 0.59 h(-1), which is also the mu (max) value for the culture. Lower values of mu (crit) were observed at higher acceleration rates. The steady state growth of bacteria stabilized at dilution rate 0.2 h(-1) was immediately disrupted after initiating acceleration at the highest acceleration rate studied-0.06 h(-2). Observation was made that differences [Delta(mu - D)] of the specific growth rates from pre-programmed dilution rates were the lowest using an acceleration rate of 0.003 h(-2) (< 4% of preset changing growth rate). The adaptability of cells to follow preprogrammed growth rate was found to decrease with increasing dilution rate-it was shown that lower acceleration rates should be applied at higher growth rates to maintain the culture in the quasi steady state. The critical specific growth rate and the biomass yields based on glucose consumption were higher if the medium contained S (0) = 5 g L(-1) glucose instead of S (0) = 10 g L(-1). It was assumed that this was due to the inhibitory effect of lactate accumulating at higher concentrations in the latter cultures. Parallel A-stat experiments at the same acceleration and dilution rates showed good reproducibility-Delta(mu - D) was less than 5%, standard deviations of biomass yields per ATP produced (Y (ATP)), and biomass yields per glucose consumed (Y (XS)) were less than 15%.

Corrosion inhibitors for small-scale heat-supply systems

Stationary oxygen concentration in a closed heat-supply system, which is filled and replenished with nondeaerated water at a temperature of 20°C, has been calculated. The calculation takes into account the system surfaceto-volume ratio and the relative added makeup water volume fraction. In the case of a system using corrosion inhibitors, the stable oxygen concentration at a preset makeup rate falls within 400–800 μg/dm3. Experiments performed in a special setup for polarization measurements showed that, at an oxygen concentration of 600 μg/dm3, a decrease in the general internal corrosion rate can be achieved using IOMS-1 and PAF-13A inhibitors at a concentration of 4–5 mg/dm3, or a zinc complex of oxyethylidenediphosphonic acid at 25 mg/dm3.

Threshold control of mutual insurance with limited commitment

We study the optimal premium policy of mutual insurance when the charged premium cannot be higher than a preset rate. We provide a complete solution to the problem and use numerical simulations to illustrate how the optimal premium policy responds to changes of outside factors. The results are useful for mutual insurance firms to design premium policies and can be used to test the behavior of these firms in empirical studies.

Accuflow an infusion rate monitor: An evaluation in pediatric patients

To evaluate the accuracy of ACCUFLOW an infusion rate monitor as compared to manual reading in pediatric surgical patients. An observational study in 47 pediatric patients undergoing elective surgical procedures and needing an intravenous fluid with expected duration of infusion of at least one hour. The infusion rate was adjusted to the required flow rate with the help of the display on the ACCUFLOW. The flow rate as indicated by the ACCUFLOW display was checked every 15 minutes till the end of one hour. A simultaneous record of manual readings was also made. A total of 470 observations were made over the one hour observation period. The infusion rate as observed on the LCD display of the ACCUFLOW compared well with manual reading. A Bland Altman analysis showed the bias between the readings with the two methods to be very small and that there is no significant difference between the methods over the drop rate of 61-74 drops/min. In addition an alarm was heard in 9 cases. The alarm was mainly because of no flow or excess flow (3 cases each). Other causes for the alarm included slow flow, faulty i.v. lines showing fluctuations in flow rate and drip chamber not placed properly (1 patient each). ACCUFLOW is a low cost device that can be used to adjust and monitor the infusion flow rate. The alarm would alert the nursing staff when there is deviation from the preset rate of infusion. ACCUFLOW could thus be an attractive option for infusion rate monitoring in developing countries with limited healthcare resources and skewed patient nurse ratios. However applicability to infants and younger children and for longer infusions needs to be determined.

A digital phase shifter

A digital phase shifter with linear phase-shift variations with a π/N step, where N is the overall division factor of used frequency dividers, is described. The device is easy to realize and intended to easily set and change a phase-shift step, carrying out the reverse (manual and automatic) phase change with a preset rate. The device is good for use in phase and ultrasonic measurement techniques.

Effects of a vertical keyboard design on typing performance, user comfort and muscle tension

To circumvent the awkward pronated hand position inherent to conventional horizontal keyboards, a vertical, split keyboard was designed with flexible cushions supporting the wrists, allowing relaxed hand and arm postures. During eight twice-weekly 30-min training sessions, the performance and subjective comfort of nine experienced typists were tested. Typing speed and error percentage, and surface electromyographic activity of six forearm muscles and two postural muscles were recorded in separate sessions at the end of each week. Typing speed rapidly recovered to the preset rate of 300 keystrokes/min and error percentages were similar for the two keyboards. The vertical keyboard caused lower muscular activity in especially finger extensor muscles, did not increase postural muscle activity, and self-reported comfort was higher. Thus, the vertical keyboard was easily mastered, was experienced as comfortable, and caused less stress on muscles sensitive to repetitive strain injuries.

Application of SCTA methods for kinetic analysis of solid state reactions and synthesis of materials

The advantages of the sample controlled thermal analysis (SCTA) for performing the kinetic analysis of solid state reaction as compared with conventional non-isothermal methods order, diffusion and formation and growth of nuclei (AvraminErofeev) controlled reactions have been analysed. It has been shown that the shape of the α-T plots recorded under a strictly constant reaction rate (CRTA) is characteristic of the kinetic model obeyed by the reaction. Thus, it would be possible to discern among boundary n just from the inspection of the shape of a single CRTA plot. The α vs. T plots of en orderi reactions have a concave shape while the α-T plots corresponding to diffusion controlled processes are sigmoid shaped with an inflection point at a particular value of α characteristic of every particular diffusion model (D2 ,D 3 or D4). The α-T profiles of reactions fitting the AvraminErofeev kinetic model start with a rise in temperature until reaching the preset reaction rate. This step is immediately followed by a temperature fall (until reaching a determined value of the reacted fraction (αn) that is depending on the value of the n coefficient in the AvraminErofeev kinetic equation) and again a temperature rise once the corresponding αn value is attained. It has been shown that the value of αn exactly agree with the value of the reacted fraction at which the reaction rate reach a maximum under isothermal conditions. This fact suggests that the part of the α-T profile in which the curve back on itself would correspond to the acceleratory period in which the total surface area of the growing nuclei would be increasing leading to an acceleration of the reaction that would be offset by a diminution of the temperature. The later rising temperature stage would correspond to the decay period in which the growing nuclei overlap among themselves with the corresponding decrease of the interface reaction area that would lead to a decrease of the reaction rate that must be compensated by a rise in temperature in order to maintain the reaction rate constant. A comparison of (CRTA) and stepwise thermal analysis (SIA) has been carried out from simulated curves. It has been shown that in the case of en orderi and diffusion controlled reactions SIA curves approach to CRTA traces as the lower and upper reaction rate thresholds becomes closest. However, the shape of the SIA α-T plots of solid state reactions following an AvraminErofeev mechanism is quite different of

Simple gradient system For capillary electrochromatography

AbstractA new gradient system for CEC was designed and adapted to a home‐built CEC system. Chromatographic separations are initiated with a predetermined mobile phase composition and, after a desired time period, a syringe pump delivers pure organic solvent at a preset flow rate into a 2 mL vial used as the inlet buffer reservoir. Mixing is achieved by the use of a microstir bar in the buffer reservoir, which in turn is driven by an air‐actuated stir plate. In this way, a convex‐shaped gradient is generated, and the mobile phase is introduced into the separation column by electro‐osmotic flow. Use of this system significantly reduced analysis time while still retaining acceptable reproducibility. Nonaqueous CEC was used for isocratic and gradient separation (&lt;3.5% RSD in retention times). Demonstrated applications include the analysis of triglycerides in different vegetable oil samples. This system is expected to be well suited for generating other types of gradients, such as pH and ionic strength gradients, in electroseparation techniques. © 2001 John Wiley &amp; Sons, Inc. J Micro Sep 13: 351–360, 2001

Evaluation of an active coronary perfusion balloon device using Doppler flow wire during PTCA.

The aim of this study was to assess whether active coronary perfusion catheters (APC) can provide a sufficient coronary flow in large caliber vessels during balloon inflation. To prevent myocardial ischemia during PTCA, these APC may be employed. However, it is as yet unknown whether the active flow rate of these devices approaches the flow rate prior to PTCA during balloon inflation. Therefore, we measured the efficacy of the APC during balloon inflation in vessels supplying a large amount of myocardium. In 12 patients (1 female, 11 males, 53 +/- 12.6 yr) with stenosed vessels (average diameter 3.4 +/- 0.26 mm), the coronary flow velocity was measured using a 0.014" Doppler guidewire, which was placed distally bypassing the balloon of the APC. The active perfusion balloon catheter was advanced through a 7F guiding catheter along a 0.014" guidewire. After removal of the guidewire, arterial blood being withdrawn from the side port of the femoral angioplasty sheath was pumped through the catheter to the distal coronary vessel. The perfusion volumes of the pump were set to different levels between 30 to 60 ml/min. Intracoronary flow rate was calculated by the angiographically assessed vessel luminal area [symbol: see text] average peak velocity [symbol: see text] 0.5. The mean coronary flow rate prior to PTCA was 43 +/- 17.7 ml/min. Maximum flow during PTCA was 55 +/- 19.6 ml/min. We found a good correlation between the preset external pump rate and the coronary flow in situ (r = 0.92). Pre-PTCA flow rates were achieved in 11 of 12 patients (92%) during balloon inflation. No relevant decrease in the arterial pressure occurred during dilation times of 4.6 +/- 1.63 min. Only two patients showed significant ECG changes during these balloon inflations. After an average follow-up period of 13 +/- 6.3 mo, only one patient (8%) had a significant re-stenosis requiring the implantation of a stent. The combination of intravascular Doppler velocity measurements with quantitative coronary angiography offers the opportunity of exact online flow registration during angioplasty. Using APC, It is possible to maintain a sufficient coronary flow in the distal vessel during balloon inflation even in large vessels. Therefore, as compared with mechanical circulatory assist devices, coronary assist by APC is a little invasive, but according to our measurements it might be a sufficient tool for performing PTCA also in high-risk patients.

A performance evaluation of slotted Aloha multiple access algorithms with fixed and variable frames for radiomobile networks

Radiomobile networks, among them GSM, DECT, TETRA, and PCN, are increasingly providing voice and data services to users over vast territories. In radiomobile systems, access to radio channels is controlled by a radio base station which sends and receives digital signals from mobile units in order to implement connections. All the digital messages are time-division multiplexed over one or more control channels, while the information flow is transmitted over shared radio channels. This paper evaluates the performance of the slotted Aloha access method with a superimposed frame structure. Its advantages, especially when channel occupancy is not detectable by all users and/or under particular traffic conditions, are pointed out. The proposed method, which has been incorporated in European trunking system standards such as MPT 1327, is suitable for both private (PMR) and public networks. The method is analyzed in terms of the average number of collisions per unit of time (or frame), with finite and infinite numbers of users, and with fixed and variable frame lengths. The analysis also includes hybrid access, i.e., simultaneous random and dedicated, which mobile fleets, for example, use to send data at a preset rate. In addition, the criteria for sizing frame lengths and investigating the stability of the methods are described. New ways of optimizing network performance are also presented. The results of the simulations are in good agreement with the theoretical predictions.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Are general resource notions still viable in reading research?

To explore the interplay between reading subcomponent efficiency and comprehension processes in terms of resource competition, 2 experiments were conducted. In Experiment 1, adults were tested on the efficiency of lexical access, semantic memory access, verbal working memory span, contextual priming, and the efficiency with which anaphors are resolved. This profile was used to predict the efficiency of high-level inference generation when readers control the pace of reading. In Experiment 2, this profile was used to predict the efficiency of high-level inferencing as text was presented at a preset rate. The data suggest that when readers control reading rate, they compensate for subcomponent inefficiency such that high-level comprehension is unrelated to this inefficiency

Are general resource notions still viable in reading research?

To explore the interplay between reading subcomponent efficiency and comprehension processes in terms of resource competition, 2 experiments were conducted. In Experiment 1, adults were tested on the efficiency of lexical access, semantic memory access, verbal working memory span, contextual priming, and the efficiency with which anaphors are resolved. This profile was used to predict the efficiency of high-level inference generation when readers control the pace of reading. In Experiment 2, this profile was used to predict the efficiency of high-level inferencing as text was presented at a preset rate. The data suggest that when readers control reading rate, they compensate for subcomponent inefficiency such that high-level comprehension is unrelated to this inefficiency

A new methodology to evaluate the mechanical properties of elastomeric closures

A quantitative method was developed to evaluate the mechanical properties of elastomeric closures commonly used in liquid parenteral dosage forms. The new methodology was based on the compression of individual stoppers facing upwards, with a stainless steel probe attached to an Instron testing machine. The Instron recorded the maximum force exerted by the closure at a preset rate and displacement value. The mechanical properties were also evaluated with the standard needle penetration force test. The compression test was found to be more sensitive in ascertaining differences in the mechanical properties of stoppers compared to the needle penetration test. Changes in the mechanical properties of closures exposed to various concentrations of acetate buffer, pH and buffer species were also evaluated in this study. The mechanical properties of all stoppers tested were affected by the acetate buffer concentration, even though their physical appearance did not change. The compression force was significantly decreased with an increase in buffer concentration, whereas the needle penetration force values were not significantly different. Since there was no significant effect of pH or citrate buffer species on the mechanical properties of closures, the changes in compression force observed were attributed to the acetate buffer species. In addition, an increase in the duration of the autoclaving cycle significantly affected the mechanical properties of polyisoprene stoppers, whereas the properties of bromo and chlorobutyl stoppers remained unchanged.