Classification Of Springs

Among the common phenomena of nature, springs are notable because of their high usefulness. Since the earliest times the homes of men have clustered around them. In arid regions their number and size may limit the population. In many humid regions springs are so numerous and similar that distinctions between them are not recognized, yet they may be caused by so many principal and minor factors or by so many combinations of these factors as to make the origin of any one spring exceedingly complex or obscure. An interesting account of the many erroneous notions held by the ancients regarding the origin of springs can be found in Paramelle. In addition, their very familiarity has brought about an indifference which has led the average investigator to pass them by. Only springs with unusual characteristics have been thought worth study. Elaborate classifications have been suggested for so-called mineral springs-those whose water is exceptional because of gas or mineral content-but a complete classification of all springs has been attempted only by Keilhack. His classes are not mutually exclusive, and his primary division into descending (absteigende) springs and ascending (aufsteigende) springs separates, not waters of unlike origin, but only waters that have unlike paths to the surface. A number of authors have made incomplete classifications for the springs of a limited region or for some special reason. The principles involved and the names used have been helpful in preparing this classification. Such classifications may be found in the works of Gregory, Meinzer, Fuller, and Johnson, cited in this paper, and in those of Hill and Vaughan, Fournier, and Kilian. References to many articles on springs will be found in Meinzer\u27s bibliography of ground water. The essential factors in the production of springs are the source of the water and the rock structure which brings it to the surface, and on these factors the classification outlined in this paper has been based. Temperature, dissolved salts, contained gases, rate and amount of flow, form and position of the spring opening are all characteristics of springs, which, while in many cases related to genesis, vary among springs of the same origin. It has seemed best to first divide springs into two groups based on character of the water and make further subdivisions on structural grounds. In the use of this classification difficulties will arise which are of two types. In the first place, the local structure in the vicinity of springs is difficult to determine, for the presence and passage of water facilitates weathering and destroys the evidence. The presence of luxuriant vegetation also tends to conceal the structure. Whatever the difficulties of determining the structural relations and origin of the water for single springs, the study of groups of springs will usually be successful. The second difficulty arises through various combinations of structures which may combine to produce a spring. The structure which plays the predominating r6le should then determine the classification of the spring. The common sense and judgment of the investigator will lead him to the proper decision, but his labor will be easier if he remembers that ground water moves through three dimensions, though our conventional methods of illustration show but two. Springs of diverse origin may, however, have peculiarities so remarkable or interesting as to justify their grouping under a common name. The proposed system is not intended to supplant the use of such descriptive terms as blowing springs and thermal springs, but to provide a series of terms expressive of genesis which will include all springs, particularly those now called, for want of a better term, common springs

Seasonal variation in meridional overturning and poleward heat transport in the Atlantic and Pacific Oceans: A model study

Numerical solutions for a model of the World Ocean are analyzed to illustrate the important changes in the meridional circulation of the ocean induced by seasonal changes in wind stress. Seasonal variations of meridional circulation and associated changes in poleward heat transport predicted by the model are most important in the Pacific where the background thermohaline circulation is relatively weak...

Testing Components of New Community Isopycnal Ocean Circulation Model

The ocean and atmosphere are both governed by the same physical laws and models of the two media have many similarities. However, there are critical differences that call for special methods to provide the best simulation. One of the most important difference is that the ocean is nearly opaque to radiation in the visible and infra-red part of the spectrum. For this reason water mass properties in the ocean are conserved along trajectories for long distances and for long periods of time. For this reason isopycnal coordinate models would seem to have a distinct advantage in simulating ocean circulation. In such a model the coordinate surfaces are aligned with the natural paths of near adiabatic, density conserving flow in the main thermocline. The difficulty with this approach is at the upper and lower boundaries of the ocean, which in general do not coincide with density surfaces. For this reason hybrid coordinate models were proposed by Bleck and Boudra (1981) in which Cartesian coordinates were used near the ocean surface and isopycnal coordinates were used in the main thermocline. This feature is now part of the HICOM model (Bleck, 2002)

RapidHRV: an open-source toolbox for extracting heart rate and heart rate variability

Heart rate and heart rate variability have enabled insight into a myriad of psychophysiological phenomena. There is now an influx of research attempting using these metrics within both laboratory settings (typically derived through electrocardiography or pulse oximetry) and ecologically-rich contexts (via wearable photoplethysmography, i.e., smartwatches). However, these signals can be prone to artifacts and a low signal to noise ratio, which traditionally are detected and removed through visual inspection. Here, we developed an open-source Python package, RapidHRV, dedicated to the preprocessing, analysis, and visualization of heart rate and heart rate variability. Each of these modules can be executed with one line of code and includes automated cleaning. In simulated data, RapidHRV demonstrated excellent recovery of heart rate across most levels of noise (>=10 dB) and moderate-to-excellent recovery of heart rate variability even at relatively low signal to noise ratios (>=20 dB) and sampling rates (>=20 Hz). Validation in real datasets shows good-to-excellent recovery of heart rate and heart rate variability in electrocardiography and finger photoplethysmography recordings. Validation in wrist photoplethysmography demonstrated RapidHRV estimations were sensitive to heart rate and its variability under low motion conditions, but estimates were less stable under higher movement settings

Andrew Melville, sacred chronology and world history: the Carmina Danielis 9 and the Antichristus

The accepted view of the ecclesiastical reformer Andrew Melville (1545–1622) as the dynamic leader of the Presbyterian movement in Jacobean Scotland has been severely eroded in recent years, with particular criticism of the actual importance of his contribution to the Kirk and to Scottish higher education. While this reductionism has been necessary, it has resulted in an inversion of the overwhelmingly positive traditional image of Melville, and does not give us a rounded assessment of his life and works. This article attempts to partially redress this balance by looking at a neglected aspect of Melville's Latin writings, which showcase his talents as a humanist intellectual and biblical commentator. It focuses on two long poems that are both commentaries and paraphrases of Daniel and Revelation: the Carmina Danielis and the Antichristus. Through these poems, we see how Melville engaged with two problems exercising reformed theologians across Europe: the dating of key biblical events and the historicised meaning of prophecies within these texts. We also find evidence that Melville read widely among both contemporary and ancient commentators on both these issues

Noise Assessment/Survey at ERAU Fleet Maintenance Hanger

One of the many hazards associated with aviation, and conducting aircraft maintenance, is the issuance of noise hazards. Federal agencies such as Occupational Health and Safety Administration have incorporated standards pertaining to threshold limit values and permissible exposure limits surrounding noise in the workplace. Our objective is to assist the work environment in the Embry-Riddle aviation hangar to assure personnel are protected from lasting effects of noise through this research. The method used for research in this paper was a combination of sound monitoring of the maintenance hangar using a sound level meter, noise dosimeter and the NIOSH Sound Level Meter application as well as using relevant previous research studies. The results of the sound monitoring determined that the noise level within the maintenance hangar was well below the OSHA Time Weighted Average of 85 dB, and the noise level peaked at 115.4 dB for a single impulse. It has been concluded that the maintenance hangar does not require a hearing conservation program at this time as the data indicates that noise levels are well within OSHA standards. However, the current data does not include the engine run-up operations