Case Study Instruments
Shari Alvine
"A case study is an empirical inquiry that investigates a contemporary phenomenon within its real-life context, especially when the boundaries between phenomenon and context are not clearly evident" (Yin, 1994).
A never ending, unresolved question integral to use and interpretation of atmospheric data concerns the uncertainties in its accuracy and quality. Uncertainties have existed and will continue to exist in all forms of environmental data and these are related to many measurement factors. There is a need to define, measure, and understand these uncertainties, and those associated with historical surface climate data are illustrated by this case study of a unique historical record. Factors that can produce uncertainties in historical observations of surface climate conditions include 1) instrument accuracy, 2) stations moves, 3) changes in observers, 4) changes and/or malfunctions of instruments, 5) changes in observation and reporting times, 6) changes in exposure and site characteristics, and 7) variations in the height of measurements and ground cover.
The high quality of data collection and recording of operational events at the Urbana station were related to those operating the station. The Urbana weather station was started by the University of Illinois on its south campus, operated as part of the new agricultural experiment station started in 1887. The College of Agriculture maintained the station, provided the best instrumentation, and leading scientists supervised its operations from its beginning in June 1888 until 1947. The ET and soil temperatures were measured in special devices designed and constructed by university staff. From 1948 to the present, the Illinois State Water Survey has maintained and staffed the station as part of its research and services program. In 1902 the Urbana station was identified by the U.S. Weather Bureau as one of its cooperative substations.
The relocation of the station to a rural area in 1984 was assessed over a 3-yr period by taking measurements at the Morrow Plots site and the new site. This produced a reduction in values with annual mean temperatures being 0.8C lower. This new rural site effectively eliminated the urban heat island effect.
The overlapping measurements made during the instrument and site changes allow assessment of the changes these shifts in sites and equipment produced, and the changes in annual temperature (in degrees Celsius) for each are
Few other long-term U.S. stations are apt to have records that compare with those at Urbana. Particularly important to the Urbana assessment is the thoughtful keeping of time-overlapping measurements when changes were made. These have allowed quantification of the changes in values resulting from shifts in instruments and station locations. Most importantly, they allow one to understand the uncertainties inherent in the historical climate record everywhere. These simply cannot be measured because of the lack of detailed record keeping and the important collection of dual data for shifts in instruments or sites. Comparable studies should be made of other weather stations that possess quality records documenting station location and instrument shifts plus overlapping measurements of temperature and precipitation when shifts were made.
This case study highlights the importance of providing principals to the transaction written notice of any material changes to the transaction in a timely manner. When a real estate licensee has knowledge of a material change to the transaction, they must provide the notice to all principals, whether or not they are requested. This Virginia Real Estate Board case illustrates this despite a mutual mistake occurring.
The property settled on March 1st, 2021. A complaint was filed, and the investigation uncovered that Mr. Doggett had not conducted a wood destroying insect inspection and presented the report to the buyer. It also found that no home inspection had occurred and no notice of a removal of contingency or amendment removing the home inspection was ratified.
The investigators learned that Mr. Doggett and purchaser both agreed that the Purchase Contract was not actually contingent on either of these inspections from the outset. Mr. Doggett also stated that he was unaware of the mistake in the contract and admitted he had taken no action to remedy it.
Mr. Doggett asserted that because it was a mutual mistake that he was absolved from having to notify the buyer since there was nothing to report. Mr. Doggett also asserted that during the initial negotiations, the purchaser stated that he did not want a home inspection; however, no writing existed to memorialize this.
Many states - including Missouri - have provisions that provide greater punishment for some felonies that are committed with, or by the use of, a .. deadly weapon" or "dangerous instrument."1 The definition o f "deadly weapon" tends to be pretty straightforward, usually a list that includes several specific items that just are deadly weapons, such as guns and knives.2 "Dangerous instrument" is deliberately left as a broader, more capacious term - defined not in terms o f a list o f instruments but in terms of those things that could be easily or "readily" used to cause serious physical injury or death.3 But precisely because o f the broad sweep o f what counts as a dangerous instrument, and the role circumstances can play in making something dangerous, courts in Missouri have taken widely divergent stances on the definition of"dangerous instruments," both in general and in particular cases.
Woods Hole Oceanographic Institution (WHOI), headquartered in Woods Hole, Massachusetts, is the largest non-profit oceanographic institution in the world. As such, it operates four primary research vessels ranging from the 279-foot Knorr, a ship set up to stay at sea for as long as eight weeks, to the 60-foot Tioga, a vessel with a range of 350 miles used for day trips to coastal waters.
Each of WHOI's research vessels has onboard sophisticated communications and navigational equipment, and the smooth functioning and upkeep of that equipment falls to Mike Gagne, the institute's marine electronics manager. Gagne's job includes coordinating all aspects of keeping the vessels' marine electronics shipshape, as well as electrical troubleshooting both on the vessels and at WHOI's on-shore facilities. It was in his capacity as an electrical troubleshooter and an electronics expert that Gagne, almost two years ago, first began to use a Fluke 434 Power Quality Analyzer and a Ti30 Thermal Imager.
The Fluke Ti30 Thermal Imager records the surface temperatures of objects and displays them as thermal images that reveal abnormal hotspots. Since electrical problems often cause an increase in temperature. If one component appears hotter than others, there could be a problem.
WHOI electrical personnel set up the Fluke 434 with current clamps and a voltage probe across the three-phase panel and left it monitoring the peaks and dips for almost two weeks. Analysis of the collected data revealed a bad connection somewhere in the panel, and the Ti30 was then brought in to locate it.
A scan of the panel with the infrared camera revealed an overheating bolt lug on a connection to the compressor in the building's central air conditioning and air quality systems."We pulled the bolt off and found that for some reason there were threads missing on the inside portion of the bolt," Gagne recalls "The nut felt tight, but the lug was a little loose. It had arc welded itself to the bus bar. Carbon in between was causing significant resistance. With the tag team of the 434 and the Ti30, we were able to solve the problem."
Besides isolating and correcting power quality issues such as harmonic distortion, the instruments are also used to troubleshoot the ships' onboard 480-volt electrical systems and their diesel/electrics propulsion systems. But one of the most interesting and revealing onboard problems was one that was detected but not corrected.
One other issue Gagne addressed with the Fluke instruments concerned two shore-to-ship power cables that feed 400-amp, 480-volt, three-phase power to docked vessels from onshore generators. Voltage sags onboard a ship at the dock were apparent when power was being supplied over one of these six-inch diameter umbilicals. In response, Gagne set up the Fluke 434 on the transformer pedestal and monitored voltage and current for a whole weekend. At the same time, onboard voltmeters monitored what was happening on the ship.
As the foregoing examples indicate, data logging capabilities add significantly to the power of the Fluke 434. Gagne notes that without data logging, a tech might not find a problem, even if he or she systematically took readings on a circuit at regular intervals. "No matter what you do, you just can't be there all the time," he says, "and maybe a transient is so quick you cannot see it (on an instrument) with the human eye. In such cases, the 434 can detect and record it (the transient). So, we park the 434 with current clamps and a voltage probe and let it record. Later, using the data, we are able to make rational repair decisions rather than using a hit-ormiss method."
Gagne says that the most important aspect of acquiring the new instruments for the institute's research vessels is to institute a proactive, not reactive, maintenance program. He says, "We don't want to say to parts suppliers, 'We had a bad panel that just burned up, and you have to hurry to send these parts because we've got downtime.' No, we want to find degrading components long before they ever start creating problems. If we don't see it in an infrared image, we want to see it in the data in the spreadsheets."
The plan is for engineers and electricians assigned to research vessels to do walk-throughs every two or three months.The plan is to establish baselines against which to compare subsequent readings. Following the establishing of baselines, the next step is to monitor equipment regularly.
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