Garden Hose Research Articles

Evaluation of fluid pressures applied to the building envelope during maintenance

Maintenance of the building envelope is required by the New Zealand Building Code. Although normal maintenance is not specifically defined, the code does limit the forces that might be applied to a building as defined in AS/NZS 1170:2002, Structural Design Actions. This article reports on research that quantifies and contextualizes the pressures that are applied to the building envelope during washing. The study includes evaluation of pressures exerted by the garden hose as well as small and medium-sized water blasters that are typically used by home-owners. A prototype test rig was designed and built to measure the forces applied by the water to flat surfaces, intersections and internal corners. Measurements were recorded at various distances from the test rig. Directly relating the recorded data to the water penetration limit state, the building envelope's design limit, identifies cleaning processes that are inappropriate and breach the NZ Building Act. The results identified that some commonly performed cleaning processes may subject a building's exterior to forces significantly greater than they are tested or designed to withstand. Significantly, the greatest forces a building's envelope (its elements and details) will experience throughout its life are those applied during the cleaning of the building.

Difference combination parametric resonance; Application to the garden hose problem

This paper discusses combination resonance phenomena in parametric systems of two or more degrees of freedom starting from a theoretical result by Mailybayev & Seyranian. We present, to the best of our knowledge, the first example of difference combination resonance in a mechanical system. That is, where the system may exhibit significant response when forced with an external frequency that is the difference between its two internal resonant frequencies. The model system studied is a double pendulum with a follower load, a non-conservative force that would be described for example by an oscillating jet of fluid, like an idealized garden hose. For this example, after the inclussion of gravity, the difference combination frequency may be lower than the two individual resonant frequencies, a surprising effect that should be taken into account when analyzing the stability of other high-dimensional systems.

Garage Demos: Using Physical Models to Illustrate Dynamic Aspects of Microscopic Biological Processes

Colorful PowerPoint presentations with detailed drawings, micrographs, and short animations have become the standard format for illustrating the fundamental features of cell biology in large introductory classes. In this essay, we describe a low-tech tool that can be included in a standard lecture to help students visualize, understand, and remember the dynamic aspects of microscopic cell biological processes. This approach involves use of common objects, including pipe insulation and a garden hose, to illustrate basic processes such as protein folding and cloning, hence the appellation "garage demos." The demonstrations are short, minimizing displacement of course content, easy to make, and provide an avenue for increasing student-faculty interaction in a large lecture hall. Student feedback over the past 4 years has been overwhelmingly positive. In an anonymous postclass survey in 2007, 90% of the respondents rated garage demos as having been very or somewhat helpful for understanding course concepts. Direct measurements of learning gains on specific concepts illustrated by garage demos are the focus of an ongoing study.

The Great American Staycation and the Risk of Stillness

The Great American Staycation and the Risk of Stillness

“Homemade” TUR-Simulator for Less Than $40 U.S.? The “TupperTM” Experience

Transurethral surgery is important in daily urologic life. In training residents it is important to develop resection skills. We introduce a homemade simulator to improve capabilities for the training of transurethral procedures. Material consists of 7 cm of a 30F garden hose, a suprapubic tube, a Tupperware box (Frankfurt, Germany), three catheter plugs, and silicone gel. Cost of materials is below $40 U.S. Transurethral procedures such as mono- and bipolar resection and RevoLix laser vaporesection were carried out. Different meat types were tested to develop a close to real resection feeling. Further, flexible cystoscopy was trained with the simulator. Multiple markings were placed inside the box. These markings had to be identified by flexible cystoscopy. The time to completion of this task was recorded. Transurethral resection and flexible cystoscopy is feasible. Pork and beef lead to a realistic feeling compared with transurethral resection. For laser surgery, pork and chicken seem to be most realistic. Further, confidence in flexible cystoscopy could be obtained. During the flexible cystoscopy task, an average time reduction of 50.96% could be achieved. This cheap and simple resection simulator allows easy training of lower urinary tract procedures. It helps young urologists to acquire basic endourologic skills. It may be beneficial for residents in the process of learning lower urinary tract surgery. Further, new techniques can be trained and may lead to a decreased risk for the patients.

Gertie and the Visitors

Gertie and the Visitors Tricia Currans-Sheehan (bio) Gertie saw them come into her lane in their beat-up Ford, pulling a wagon with a tarp on it. They looked like ne’er-do-wells but she was happy to see them. She was eighty-three and had been a widow for ten years now. She hated the loneliness of it. She heard the knock at the door and expected a man, but it was a woman with three girls. And she was a big woman. Gertie was tall but thin like a willow. This woman was a walnut tree—solid and heavy and her skin was dark like oiled wood. “I was wondering if you needed some work done. Heard in town that you were sick and could use help.” “Now who told you that?” Gertie said. “Was it Bud at the gas station or Homer at the grocery?” “Homer. That’s who said it,” the woman replied. “I see that your lawn needs mowing. Show me your mower and we’ll get right on it.” Before Gertie even had a chance to say no, this woman was walking back to the shed behind Gertie’s brick house and opening the door. She called to the youngest girl, “Ruby, you keep out of the way.” She took out the mower and pulled the cord a few times and it started. She began mowing, slowly, because the grass was so thick. The oldest two girls found Gertie’s rakes and were raking up the grass and carrying it to the grove in back. No one ever mowed the grove of walnuts and oaks. Ruby found the porch swing and sat on it and looked around. Gertie walked over and gave her a small push. The girl jumped off like she was scared. Gertie said, “No, you stay on. Just want to show you that it moves back and forth.” She sat on her wooden rocker and pretended not to notice the girl. When Gertie rocked back and forth, Ruby stuck out her foot and pushed off from the rail on the side. They both watched the lawn mowing. [End Page 152] Gertie had been sick for two months from congestive heart failure. Her neighbors had mowed a few times but they couldn’t keep up with things. Her garden had gone to hell. Weeds had taken over. Maybe these folks could hoe it. But how would she pay them? She only had her Social Security and her teacher’s pension. She watched as the lawn mower choked from too much grass and stopped. This beast of a woman tried to start it but it wouldn’t go. She unscrewed the gas lid, looked into the tank and shook her head. “Where’s your gas?” the woman called out. “In that red can,” Gertie said. “In the corn crib.” The woman found the red can and poured it but nothing came out. Then Gertie watched her push the mower over to her car. She got into the back seat and took out a piece of garden hose. The woman opened her gas tank lid, put the hose in it and then lay on the ground and sucked on the other end of the hose. When gas came out, she spit a lot and quickly put the end into the mower gas tank. In a minute it was filled and she pulled the hose away and lifted it up high so the gas wouldn’t keep coming out. “My, my,” Gertie said aloud. Were they gypsies? That’s who would pull a stunt like that. That’s probably how they got gas all the time. Gertie felt sick. She’d pay them five dollars when they were done and tell them to leave. She’d heard about folks like this who would befriend you and then rob you blind. Sixteen years ago when she’d gone on that pilgrimage to Rome with Monsignor McCain, she’d seen gypsies all over. As they were walking from St. Peter’s to the Vatican Museum and Sistine Chapel, a woman was on the sidewalk nursing a toddler. Gertie had gasped seeing this woman expose her...

Characteristics of porous‐hose infrasonic wind‐noise‐reducing filters.

Spatial wind‐noise‐reducing filter technologies are widely used in infrasound recording because wind is the primary source of noise in this frequency band. While permanent infrasound arrays often make use of large solid‐pipe rosette spatial filters, portable or temporary arrays must use other materials, the most popular of which is porous garden hose. While undeniably effective at reducing wind noise, porous hoses have distinct frequency‐dependent effects on signal amplitudes and by changing the phase response of the microphone can have deleterious effects on bearing accuracy. In this presentation the effects of the use of porous‐hose wind‐noise‐reducing filters are discussed, both in terms of the effectiveness of noise reduction and the effects on signal characteristics.

Saint Nathan

Saint Nathan

Sprayer Device Streamlines Sodium Hypochlorite Cleanup

This article describes the 2008 Opflow Gimmicks & Gadgets Contest First Place Winner, a rotating sprayer device that uses a standard garden hose for a water supply and runs with minimal monitoring to rinse down the lining of a sodium hypochlorite storage tank. The article provides a list of materials used for building the device, describes how it is constructed and operated, and discusses the benefits of using the device.

International Outcry Follows Attacks on Neuroscientist's Home

International Outcry Follows Attacks on Neuroscientist's Home

Physiological analysis of the lymphatic system in the eastern painted turtle (Chrysemys picta picta)

Examination into the anuran lymphatic system has led to a comprehensive understanding of lymphatics, including the importance of synchrony in fluid-balance maintenance. However, little research has been conducted on the lymphatics of turtles and other reptilian vertebrates. Using pressure-peak recordings created through cannulation of both lymph hearts of the eastern painted turtle, Chrysemys picta picta (Schneider, 1783), the lymph heart contraction rate was verified and the interbeat interval patterns were examined using Poincaré plots. The lymph heart beating rate was determined to be 38.2 beats·min–1with a mean pulse pressure of 2.40 ± 1.44 mm Hg (1 mm Hg at 0 °C = 133.3224 Pa). Poincaré plots are useful in displaying nonlinear sequential data and are often given descriptive names related to the overall pattern. The Poincaré plot resembled a garden hose nozzle spray, indicating a large variability in interbeat time intervals with periods of multiple-beat patterns. The degree of bilateral lymph heart synchrony was determined in the turtle using the mean time difference between right and left lymph heart systoles. Results show that chelonian lymph hearts do in fact beat in synchrony, with over 50% of contractions occurring within 100 ms of each other. This indicates shared neuronal control and may suggest an energetic advantage to fluid homeostasis.

Embryonic rotation of the stomach and midgut loop

The topography of the adult gastrointestinal tract and viscera together with the remodeling of their original mesenteric connections create some of the most vexing spatial relationship problems encountered in mastering the clinical anatomy of the human body. The complex, tortuous and, on first inspection, haphazard arrangement of the digestive tract is neither easily explained in text nor clearly elucidated with illustrations. Thirty years of personal experience teaching human embryology has demonstrated that when students attempt to follow the developmental succession of 90° and 180° rotations around the body's three axes their understanding often becomes more knotted‐up than straightened out. While animations greatly facilitate understanding, cognitive deficits persist for students who have difficulty visualizing and spatially integrating the chronology and final disposition of structures into their own body schema or image. All anatomists who teach in a dissection lab have witnessed many a student holding and maneuvering the heart or a bone against his or her own body until it is in the correct orientation. I believe this sensory‐motor learning process helps to personalize the location, orientation and relationships of structures within the student's own body. Through this kinesthetic and proprioceptive process, students gain a deeper appreciation for their own body and, consequently, an enhanced ability to mentally map anatomical structures in other bodies. Building upon this learning process, I have developed a didactic routine using a 15″ party balloon and 4′ rubber garden hose that permits students to observe and perform directly the rotations of the stomach and midgut loop.

Microfluidics and a garden hose

Microfluidics devices are well known for their ability to perform complex manipulations on minute samples, but they can also be powerful tools for analyzing large sample volumes.

Year One, and: The Twenty-Third Sunday in Ordinary Time

Year One, and: The Twenty-Third Sunday in Ordinary Time Marsha Rabe (bio) Year One Griefe brought to numbers cannot be so fierce,For he tames it, that fetters it in verse. —John Donne This is my mother's first yeardead. The poppies she cheer-led into bloomlast June now rupture the groundwithout her, their shrill colors as conceitedas popes on the Vatican balcony, bobbingand waving, a line of splendidLeos, Pius one through twelve,fat Johns, gaunt Johns, seeminglyinterchangeable, seemingly eternal.This is her first Christmas Eve—no Santa.This is her first Easter—no eggs, no resurrection—Her first Mother's Day—no guilt. Ha!Her first birthday. But who's counting?She is rhododendron now as much as wind chime,squirrel as much as green garden hose,grass grub, trowel. I love my new calendar, [End Page 178] how its days repeat and rhyme, amassing her absence.Today I will put my shovel into the earth, feel the dirtyield like flesh, hear the clang of metal on rockas if the rock were bone. I will extract the rockand in the void the rock leaves I will plantthis thing called goat's beard, fanning outits gauzy roots, composting, watering, tending it.She will be goat's beard for now, and laterblack-eyed Susan on the hill.True gardeners work by the phases of the moon.Foxes return on time. I possess her now as never.I summon her. She rises on command.The dead can learn to obey. The Twenty-Third Sunday in Ordinary Time The priest at St. Mary's is miked,so the Body of Christ sounds crisp as a snack.I'm sorry for him, his Holy Communionbroadcast like a song. At the Sign of Peace, my mother says sheloves me—now, at last. She says so urgently,as if she's just remembered an unpaid bill. I wish I were small enough to fit inside her—in her hand—or better yet, to ridelike Christ's white corpse in the shallowspoon of her tongue. [End Page 179] Marsha Rabe Marsha Rabe is the director of publications at Southern Connecticut State University in New Haven, Connecticut. She has published a short story in the Atlantic Monthly and a personal essay on the op-ed page of the New York Times. Copyright © 2007 University of Nebraska Press

Water Nozzles

The following type of nozzle problem is found in some introductory-level physics textbooks.1–3 The (average) flow speed of water through and out a hose with a cross-sectional area AH is vH. If a nozzle with an exit area AN < AH is attached to the hose, what is the speed vN of the water out of it? The books simply apply the continuity equation AHvH = ANvN to the nozzle to obtain vN = (AH/AN)vH. This solution is not correct because it does not take account of the fact that attaching the nozzle to the hose reduces the flow speed in it. So the books' values of vN must always be too high, sometimes by large amounts. It should not seem surprising that it takes more time to fill a watering can with a garden hose when there is a nozzle at the end of it than when there isn't. This paper will explain how a water nozzle actually works, and for a situation with a simple water source, the correct flow speed from a nozzle will be derived.

Water in a Coiled Hose

Sometimes things just don't work the way that you think they should. The problem “Coming up Empty,” described in Bet You Can't! Science Impossibilities to Fool You by Vicki Cobb and Kathy Darling is a perfect example.1 In this problem, when water is poured into the top open end of a coiled garden hose, common sense tells us that it should eventually come out of the other end. However, in this case the water will overflow from the top instead of coming out of the other end!

Spraying a Wall with a Garden Hose

Spraying a Wall with a Garden Hose

Shear strength characteristics of sand-mixed with granular rubber

Waste materials such as waste tires, rubbers, and plastic materials are normally produced in every society, entering the environment and causing serious problems. These problems may be somehow reduced by finding applications for them in engineering, for example, as lightweight materials for backfill in geotechnical projects. To this aim, this paper demonstrates how shear strength characteristics of sand mixed with various percentages of waste garden hose grains are altered. A relatively, uniform sand has been mixed with waste hose grains in loose and slightly compacted states. Waste hose grains were prepared with special popular machinery in a local area. Various sand-rubber mixtures having 0%, 10%, 15%, 20%, 50%, 70%, and 100% waste hose particles by weight were chosen. The rubber grains were distributed in the sand such that uniform mixtures are obtained. In order to compare the shear strength of different sand-rubber samples, two compaction states were considered. The results show that the influencing parameters on shear strength characteristics of sand-rubber mixtures are normal stress, mixture unit weight, and rubber content. With the selected waste hose particles, compaction states, and rubber contents, the initial friction angle φ1 does not change significantly. However, an apparent cohesion appears in the mixtures. From environmental point of view and due to lightweight material for the sand-waste hose particles, it may be useful to use such materials in corresponding geotechnical projects.

Marine attacks on towed acoustic arrays

Approved for public release. Distribution unlimited. Editor's note: The author is on the staff of the Dean of the College of Ocean and Fishery Sciences, University of Washington, Seattle, but is presently on detail to the Naval Sea Systems Command, PMS 435, Washington, D.C. As explorationists know, sound is commonly used to investigate and understand phenomena in the ocean and the structure of geologic strata beneath the sea. But, as they may not know, it is also used by submarines and surface ships to find and track other submarines and ships. In all cases, the sound is detected and recorded through hydrophones often deployed in long linear arrays to permit the determination of spatial information. These arrays are typically long flexible tubes or hoses like a large garden hose or fire hose. The hose is either a flexible solid structure or hollow and liquid-filled with hydrophones and their power and transmitting wires embedded within. Hydrophone arrays, similar to those widely used in the search for undersea hydrocarbon deposits, are used by the U.S. Navy, principally by submarines, to silently listen for the sounds of adversaries. Although these military arrays differ from the …

Response to the comments of D. R. Blackman and Y. Peleg (JRA 14, 411-14)

The comments on my article (JRA 13,104-32) by Blackman and Peleg, which are much appreciated, reflect prevailing discussions on Roman hydraulic engineering practices as well as on the relevant paragraphs of Vitruvius (8.6). Blackman focuses mainly on technical aspects, while Peleg aims at archaeological arguments.Blackman starts with a discussion of the term ‘siphon’, which he regrets being used as it could lead to misunderstanding: ‘siphon’ would represent a “real” siphon, not an “inverted” siphon, suggesting that I must have meant that there was a real siphon at Aspendos. However, in archaeology “siphon” is generally accepted to represent an inverted siphon. There is no misunderstanding: at Aspendos we have an inverted siphon, and since real siphons are not known in classical aqueduct systems, there is no objection to using ‘siphon’ and ‘inverted siphon’ for one and the same notion. Subsequently he states: “The presence of air pockets and so on is almost irrelevant to operations [of siphons] if no point in the system lies above the Hydraulic Gradient Line; were it not so, no garden hose would work reliably” This is a misconception. It is only due to the fact that our garden hoses are connected to supplies with elevated pressures that we get water from them. If we would connect the hose to a low-pressure source (e.g., to a rainwater container standing at ground level), we have to straighten out the coils before water will emerge. If the hose is coiled up, for example, on a wall support but positioned below the free water surface in the container to which it is connected, while we are holding the free end somewhere near the ground, we have nothing but an inverted siphon with high points. If air pockets are irrelevant, water should come out, but it does not if air is in the hose. For problems associated with air pockets in gravity-driven closed conduit systems (which classical siphons must be considered to be), see G. Corcos, Air in water pipes (1989) and H. T. Falvey, Air-water flow in hydraulic structures (1980).