8 research outputs found
Interview with Jacque Feist
An interview with Kansas Master Teacher award recipient Jacque Fesit.https://scholars.fhsu.edu/ors/1190/thumbnail.jp
SCADA System Maintenance: An Often Overlooked Necessity
The design and implementation of a Supervisory Control and Data Acquisition (SCADA) system is typically undertaken by expert engineers and integration contractors. In order to provide a robust and reliable SCADA system, good design and installation practices are required. Preserving the initial SCADA system reliability requires good maintenance. Unfortunately, SCADA maintenance is often overlooked or underestimated. There are two potential providers for SCADA maintenance activities. Some SCADA maintenance activities are best provided by the developer or installer of the SCADA system, before closing out a project contract. Other SCADA maintenance requirements are best provided by the irrigation district or SCADA system owner. Because SCADA systems are typically custom assemblies of hardware and software, each one is unique. However, there exists an almost universal set of fundamental maintenance requirements that is not always a priority during the SCADA system installation and commissioning phases. When the most basic SCADA maintenance requirements are not possessed, there are two possible results: SCADA system performance deteriorates, and long-term maintenance becomes overly expensive. This paper introduces a set of fundamental items that are necessary for long-term SCADA system maintenance, in addition to the most basic necessity: an adequate maintenance budget
Flow Rate Equation for Suppressed and Submerged Sluice Gates
In irrigation projects, the control and measurement of flow rates at key bifurcation points is essential. Sluice gates at the heads of irrigation canals are used by operators to control the flow into these canals. In US irrigation districts, canal operators often estimate flow rate at the heads of canals by “experience” unless they have a flume downstream. For example, they may open a gate a certain number of turns for a change in flow rate, regardless of upstream and downstream conditions. Theoretical estimates of discharge are often inaccurate in field situations. Problems include varying and uncertain discharge coefficients, entrance and exit conditions, floor steps, gate orientation, sensor locations, free and submerged conditions, etc. Automatic control of flow rate with electronic devices (for example, programmable logic controllers) has been challenging at canal headgates because of uncertainties of what formulas and coefficients to use. Other devices are often not practical at these locations (flumes may require too much head loss, ultrasonic meters need long averaging periods, etc.). This paper develops calibration equations for one particular sluice gate configuration so that it can be used for automation of canal headgates. It modifies empirical methods used by others. With this method, the standard deviation of discharge predication is within 4.5 percent
Local text cohesion, reading ability and individual science aspirations: key factors influencing comprehension in science classes
In response to the concern of the need to improve the scientific skills of school children, this study
investigated the influence of text design (in terms of text cohesion) and individual differences, with
the aim of identifying pathways to improving science education in early secondary school (Key
Stage 3). One hundred and four secondary school children (56 females, 48 males), aged 12–13
years took part in the study. To assess the influence of local cohesion (lexical and grammatical links
between adjacent sentences) in science texts, we measured students’ comprehension (through multiple
choice questions) of science text that was high and low in local cohesion. To explore the role of
individual differences, students completed tests to measure general reading ability, general intelligence,
facets of conscientiousness, science self-concept and individual, friends and family aspirations
in science. Students were more accurate in answering comprehension questions after reading
text that was high in cohesion than low in cohesion, suggesting that high local text cohesion
improved students’ comprehension of science text. Reading ability predicted increased comprehension
for both text designs. Individual aspirations in science accounted for unique variance for comprehension
for high cohesion text. Implications for the teaching of secondary school science are
discussed
Pump Performance with Sand Wear
In many installations, pump performance declines over time due to sand wear. In order to pinpoint the type and rate of wear caused by pumping water with higher-than-average sand concentrations and its direct effect on various pump impeller materials, vertical pump impeller/bowl assemblies of approximately 900 GPM were each pumped for up to 2500 hours with high concentrations of sand in the water. Two different impeller materials were used for a total of five configurations. Well pump operation was simulated by maintaining a constant discharge pressure. The degrading performance, in terms of changing flow rate and kilowatt load, was recorded over time