MIXED GAS DECOMPRESSION THEORY with ALGORITHMS and STATISTICS RGBM Technical Series 6 Bruce R
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Standard Operating Procedures for Scientific Diving
Standard Operating Procedures for Scientific Diving The University of Texas at Austin Marine Science Institute 750 Channel View Drive, Port Aransas Texas 78373 Amended January 9, 2020 1 This standard operating procedure is derived in large part from the American Academy of Underwater Sciences standard for scientific diving, published in March of 2019. FOREWORD “Since 1951 the scientific diving community has endeavored to promote safe, effective diving through self-imposed diver training and education programs. Over the years, manuals for diving safety have been circulated between organizations, revised and modified for local implementation, and have resulted in an enviable safety record. This document represents the minimal safety standards for scientific diving at the present day. As diving science progresses so must this standard, and it is the responsibility of every member of the Academy to see that it always reflects state of the art, safe diving practice.” American Academy of Underwater Sciences ACKNOWLEDGEMENTS The Academy thanks the numerous dedicated individual and organizational members for their contributions and editorial comments in the production of these standards. Revision History Approved by AAUS BOD December 2018 Available at www.aaus.org/About/Diving Standards 2 Table of Contents Volume 1 ..................................................................................................................................................... 6 Section 1.00 GENERAL POLICY ........................................................................................................................ -
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SCIENTIFIC AMERICAN FRONTIERS PROGRAM #1503 "Going Deep" AIRDATE: February 2, 2005 ALAN ALDA Hello and welcome to Scientific American Frontiers. I'm Alan Alda. It's said that the oceans, which cover more than two thirds of the earth's surface, are less familiar to us than the surface of the moon. If you consider the volume of the oceans, it's actually more than ninety percent of the habitable part of the earth that we don't know too much about. The main reason for our relative ignorance is simply that the deep ocean is an absolutely forbidding environment. It's pitch dark, extremely cold and with pressures that are like having a 3,000-foot column of lead pressing down on every square inch -- which does sound pretty uncomfortable. In this program we're going to see how people finally made it to the ocean floor, and we'll find out about the scientific revolutions they brought back with them. We're going to go diving in the Alvin, the little submarine that did so much of the work. And we're going to glimpse the future, as Alvin's successor takes shape in a small seaside town on Cape Cod. That's coming up in tonight's episode, Going Deep. INTO THE DEEP ALAN ALDA (NARRATION) Woods Hole, Massachusetts. It's one of the picturesque seaside towns that draw the tourists to Cape Cod each year. But few seaside towns have what Woods Hole has. For 70 years it's been home to the Woods Hole Oceanographic Institution — an organization that does nothing but study the world's oceans. -
Full Paper/Talk Deep Stops and Shallow Stops – Fact and Fancy
Full Paper/Talk Deep Stops and Shallow Stops – Fact and Fancy B.R. Wienke1 and T.R. O’Leary2 1 C&C Dive Team Ldr, Program Manager Computational Physics, LANL, MS D490, Los Alamos, NM 87545 [email protected] 2 Director, NAUI Technical Diving Operations, 33256 State Rd 100, South Padre Island, TX, 78597 Abstract The question of deep stops and shallow stops is interesting and fraught with controversy in diving circles and operations, training, exploration and scientific endeavors. Plus frought with some misunderstanding which is understandable as the issues are complex. We therefore attempt a short history of deep and shallow stops, physical aspects, staging differences, diving tests, models with data correlations and data banks with user statistics and DCS outcomes as diver amplification. Pros and cons of both deep stop and shallow stop staging are presented. Misfacts are righted when appropriate. Chamber, wet and Doppler tests are contrasted. A compendium of Training Agency Standards regarding deep and shallow stops is included. Dive software is also detailed. Some commercial diving operations are discussed. A short tabulation of dive computer and software algorithms is given. From diving data, tests, DCS outcomes and field usage, we conclude that both deep stops and shallow stops are safely employed in recreational and technical diving. That is a good thing but choose your deco wisely and know why. Keywords: computational models, decompression staging, profile data, risk, statistical correlations, tests Acronyms and Nomenclature ANDI: Association of Nitrox Diving Instructors. BM: bubble phase model dividing the body into tissue compartments with halftimes that are coupled to inert gas diffusion across bubble film surfaces of exponential size distribution constrained in cumulative growth by a volume limit point. -
Vocal Cord Dysfunction JAMES DECKERT, MD, Saint Louis University School of Medicine, St
Vocal Cord Dysfunction JAMES DECKERT, MD, Saint Louis University School of Medicine, St. Louis, Missouri LINDA DECKERT, MA, CCC-SLP, Special School District of St. Louis County, Town & Country, Missouri Vocal cord dysfunction involves inappropriate vocal cord motion that produces partial airway obstruction. Patients may present with respiratory distress that is often mistakenly diagnosed as asthma. Exercise, psychological conditions, airborne irritants, rhinosinusitis, gastroesophageal reflux disease, or use of certain medications may trigger vocal cord dysfunction. The differential diagnosis includes asthma, angioedema, vocal cord tumors, and vocal cord paralysis. Pulmo- nary function testing with a flow-volume loop and flexible laryngoscopy are valuable diagnostic tests for confirming vocal cord dysfunction. Treatment of acute episodes includes reassurance, breathing instruction, and use of a helium and oxygen mixture (heliox). Long-term manage- ment strategies include treatment for symptom triggers and speech therapy. (Am Fam Physician. 2010;81(2):156-159, 160. Copyright © 2010 American Academy of Family Physicians.) ▲ Patient information: ocal cord dysfunction is a syn- been previously diagnosed with asthma.8 A handout on vocal cord drome in which inappropriate Most patients with vocal cord dysfunction dysfunction, written by the authors of this article, is vocal cord motion produces par- have intermittent and relatively mild symp- provided on page 160. tial airway obstruction, leading toms, although some patients may have pro- toV subjective respiratory distress. When a per- longed and severe symptoms. son breathes normally, the vocal cords move Laryngospasm, a subtype of vocal cord away from the midline during inspiration and dysfunction, is a brief involuntary spasm of only slightly toward the midline during expi- the vocal cords that often produces aphonia ration.1 However, in patients with vocal cord and acute respiratory distress. -
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REVIEW COPD Physiological and clinical relevance of exercise ventilatory efficiency in COPD J. Alberto Neder1, Danilo C. Berton1,2, Flavio F. Arbex3, Maria Clara Alencar4, Alcides Rocha3, Priscila A. Sperandio3, Paolo Palange5 and Denis E. O’Donnell1 Affiliations: 1Respiratory Investigation Unit and Laboratory of Clinical Exercise Physiology, Queen’s University and Kingston General Hospital, Kingston, ON, Canada. 2Division of Respiratory Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil. 3Pulmonary Function and Clinical Exercise Physiology, Respiratory Division, Federal University of Sao Paulo, Sao Paulo, Brazil. 4Division of Cardiology, Federal University of Minas Gerais, Belo Horizonte, Brazil. 5Dept of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy. Correspondence: J. Alberto Neder, 102 Stuart Street, Kingston, Ontario, Canada K7L 2V6. E-mail: [email protected] @ERSpublications Ventilatory efficiency is a key measurement for the interpretation of cardiopulmonary exercise testing in COPD http://ow.ly/1nsY307pbz8 Cite this article as: Neder JA, Berton DC, Arbex FF, et al. Physiological and clinical relevance of exercise ventilatory efficiency in COPD. Eur Respir J 2017; 49: 1602036 [https://doi.org/10.1183/13993003.02036- 2016]. ABSTRACT Exercise ventilation (V′E) relative to carbon dioxide output (V′CO2) is particularly relevant to patients limited by the respiratory system, e.g. those with chronic obstructive pulmonary disease (COPD). ′ − ′ High V E V CO2 (poor ventilatory efficiency) has been found to be a key physiological abnormality in symptomatic patients with largely preserved forced expiratory volume in 1 s (FEV1). Establishing an ′ − ′ association between high V E V CO2 and exertional dyspnoea in mild COPD provides evidence that exercise intolerance is not a mere consequence of detraining. -
Ozone Therapy: Beyond Oxygen the Most Needed Adjunct to Veterinary Medicine Introduction of Ozone
Ozone Therapy: Beyond Oxygen The Most Needed Adjunct to Veterinary Medicine Introduction of Ozone Margo Roman, D.V.M., CVA, COT, CPT MASH Main St Animal Services of Hopkinton Hopkinton MA 01748 www.mashvet.com • OZONE is a trivalent oxygen molecule. Three O2 + electrical spark/ lightning= 2 O3. It is very reactive and will return to 3 O2 molecules giving high levels of O2. Healthy cells need Oxygen • Ozone is one of the most beneficial substances on this planet, and the BAD science you hear quoted on the news every night is causing you to subconsciously be afraid of nature, and therefore, a part of life itself. They tell you that somehow hydrogen plus nitrogen or sulfur equals ozone. H + N + S = 03? Not on this planet it doesn't! What is ozone? Simply, oxygen. Three atoms of nature's oxygen. It exists in a very active form for about 30 minutes before breaking down into two atoms of regular oxygen - by giving up one atom of singlet oxygen. Where does ozone come from? Nature. And nature is efficient. The new growth in the forests, the trees, the grass on your front lawn, and the plankton in the ocean are continually creating oxygen. • • If you have seen Inconvenient Truth, the Al Gore documentary on Global warming, there is one scene that brings it all together. In one section he discusses the CO2 levels over the Pacific Ocean. In addition to the original measurements that began in 1965, they were able to measure the levels from hundreds of years ago by taking samples from deep within glaciers. -
Development of the Crew Dragon ECLSS
ICES-2020-333 Development of the Crew Dragon ECLSS Jason Silverman1, Andrew Irby2, and Theodore Agerton3 Space Exploration Technologies, Hawthorne, California, 90250 SpaceX designed the Crew Dragon spacecraft to be the safest ever flown and to restore the ability of the United States to launch astronauts. One of the key systems required for human flight is the Environmental Control and Life Support System (ECLSS), which was designed to work in concert with the spacesuit and spacecraft. The tight coupling of many subsystems combined with an emphasis on simplicity and fault tolerance created unique challenges and opportunities for the design team. During the development of the crew ECLSS, the Dragon 1 cargo spacecraft flew with a simple ECLSS for animals, providing an opportunity for technology development and the early characterization of system-level behavior. As the ECLSS design matured a series of tests were conducted, including with humans in a prototype capsule in November 2016, the Demo-1 test flight to the ISS in March 2019, and human-in-the-loop ground testing in the Demo-2 capsule in January 2020 before the same vehicle performs a crewed test flight. This paper describes the design and operations of the ECLSS, the development process, and the lessons learned. Nomenclature AC = air conditioning AQM = air quality monitor AVV = active vent valve CCiCap = Commercial Crew Integrated Capability CCtCap = Commercial Crew Transportation Capability CFD = computational fluid dynamics conops = concept of operations COPV = composite overwrapped -
Dysbarism - Barotrauma
DYSBARISM - BAROTRAUMA Introduction Dysbarism is the term given to medical complications of exposure to gases at higher than normal atmospheric pressure. It includes barotrauma, decompression illness and nitrogen narcosis. Barotrauma occurs as a consequence of excessive expansion or contraction of gas within enclosed body cavities. Barotrauma principally affects the: 1. Lungs (most importantly): Lung barotrauma may result in: ● Gas embolism ● Pneumomediastinum ● Pneumothorax. 2. Eyes 3. Middle / Inner ear 4. Sinuses 5. Teeth / mandible 6. GIT (rarely) Any illness that develops during or post div.ing must be considered to be diving- related until proven otherwise. Any patient with neurological symptoms in particular needs urgent referral to a specialist in hyperbaric medicine. See also separate document on Dysbarism - Decompression Illness (in Environmental folder). Terminology The term dysbarism encompasses: ● Decompression illness And ● Barotrauma And ● Nitrogen narcosis Decompression illness (DCI) includes: 1. Decompression sickness (DCS) (or in lay terms, the “bends”): ● Type I DCS: ♥ Involves the joints or skin only ● Type II DCS: ♥ Involves all other pain, neurological injury, vestibular and pulmonary symptoms. 2. Arterial gas embolism (AGE): ● Due to pulmonary barotrauma releasing air into the circulation. Epidemiology Diving is generally a safe undertaking. Serious decompression incidents occur approximately only in 1 in 10,000 dives. However, because of high participation rates, there are about 200 - 300 cases of significant decompression illness requiring treatment in Australia each year. It is estimated that 10 times this number of divers experience less severe illness after diving. Physics Boyle’s Law: The air pressure at sea level is 1 atmosphere absolute (ATA). Alternative units used for 1 ATA include: ● 101.3 kPa (SI units) ● 1.013 Bar ● 10 meters of sea water (MSW) ● 760 mm of mercury (mm Hg) ● 14.7 pounds per square inch (PSI) For every 10 meters a diver descends in seawater, the pressure increases by 1 ATA. -
Air-Sea Gas Exchange
Air-Sea Gas Exchange OCN 623 – Chemical Oceanography 17 March 2015 Readings: Libes, Chapter 6 – pp. 158 -168 Wanninkhof et al. (2009) Advances in quantifying air-sea gas exchange and environmental forcing, Annual Reviews of Marine Science © 2015 David Ho and Frank Sansone Overview • Introduction • Theory/models of gas exchange • Mechanisms/lab studies of gas exchange • Field measurements • Parameterizations Why do we care about air-water gas exchange? . Globally, to understand cycling of biogeochemically important trace gases (e.g., CO2, DMS, CH4, N2O, CH3Br) . Regionally and locally . To understand indicators of water quality (e.g., dissolved O2) . To predict evasion rates of volatile pollutants (e.g., VOCs, PAHs, PCBs) Factors Influencing Air-water Transfer of Mass, Momentum, Heat From SOLAS Science Plan and Implementation Strategy Basic flux equation Concentration gradient Flux (mol cm-3) (mol cm-2 s-1) “driving force” Gas transfer velocity (cm s-1) “resistance” k: Gas transfer velocity, piston velocity, gas exchange coefficient Cw: Concentration in water near the surface Ca: Concentration in air near the surface α: Ostwald solubility coefficient (temp-compensated Bunsen coeff) Basic conceptual model Turbulent atmosphere C Atmosphere a Laminar Stagnant Cas Boundary Layer zFilm Cws (transport by Ocean molecular diffusion) Cw Turbulent bulk liquid F = k(Cw-αCa) Air/water side resistance Magnitude of typical Ostwald solubility coefficients He ≈ 0.01 Water-side resistance O2 ≈ 0.03 CO2 ≈ 0.7 DMS ≈ 10 Air- and water-side resistance CH3Br -
Exploration of the Deep Gulf of Mexico Slope Using DSV Alvin: Site Selection and Geologic Character
Exploration of the Deep Gulf of Mexico Slope Using DSV Alvin: Site Selection and Geologic Character Harry H. Roberts1, Chuck R. Fisher2, Jim M. Brooks3, Bernie Bernard3, Robert S. Carney4, Erik Cordes5, William Shedd6, Jesse Hunt, Jr.6, Samantha Joye7, Ian R. MacDonald8, 9 and Cheryl Morrison 1Coastal Studies Institute, Louisiana State University, Baton Rouge, Louisiana 70803 2Department of Biology, Penn State University, University Park, Pennsylvania 16802-5301 3TDI Brooks International, Inc., 1902 Pinon Dr., College Station, Texas 77845 4Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana 70803 5Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave., Cambridge, Massachusetts 02138 6Minerals Management Service, Office of Resource Evaluation, New Orleans, Louisiana 70123-2394 7Department of Geology, University of Georgia, Athens, Georgia 30602 8Department of Physical and Environmental Sciences, Texas A&M – Corpus Christi, Corpus Christi, Texas 78412 9U.S. Geological Survey, 11649 Leetown Rd., Keameysville, West Virginia 25430 ABSTRACT The Gulf of Mexico is well known for its hydrocarbon seeps, associated chemosyn- thetic communities, and gas hydrates. However, most direct observations and samplings of seep sites have been concentrated above water depths of approximately 3000 ft (1000 m) because of the scarcity of deep diving manned submersibles. In the summer of 2006, Minerals Management Service (MMS) and National Oceanic and Atmospheric Admini- stration (NOAA) supported 24 days of DSV Alvin dives on the deep continental slope. Site selection for these dives was accomplished through surface reflectivity analysis of the MMS slope-wide 3D seismic database followed by a photo reconnaissance cruise. From 80 potential sites, 20 were studied by photo reconnaissance from which 10 sites were selected for Alvin dives. -
Deadly Acute Decompression Sickness in Risso's Dolphins
www.nature.com/scientificreports OPEN Deadly acute Decompression Sickness in Risso’s dolphins A. Fernández, E. Sierra, J. Díaz-Delgado, S. Sacchini , Y. Sánchez-Paz, C. Suárez-Santana, M. Arregui, M. Arbelo & Y. Bernaldo de Quirós Received: 19 April 2017 Diving air-breathing vertebrates have long been considered protected against decompression sickness Accepted: 5 October 2017 (DCS) through anatomical, physiological, and behavioural adaptations. However, an acute systemic gas Published: xx xx xxxx and fat embolic syndrome similar to DCS in human divers was described in beaked whales that stranded in temporal and spatial association with military exercises involving high-powered sonar. More recently, DCS has been diagnosed in bycaught sea turtles. Both cases were linked to human activities. Two Risso’s dolphin (Grampus griseus) out of 493 necropsied cetaceans stranded in the Canary Islands in a 16-year period (2000–2015), had a severe acute decompression sickness supported by pathological fndings and gas analysis. Deadly systemic, infammatory, infectious, or neoplastic diseases, ship collision, military sonar, fsheries interaction or other type of lethal inducing associated trauma were ruled out. Struggling with a squid during hunting is discussed as the most likely cause of DCS. Pathologies related to efects of changes in pressure are well known among human divers. Decompression sick- ness (DCS) is a syndrome related to the formation of gas bubbles in blood and/or tissues when the sum of the dissolved gas tensions exceeds the local absolute pressure. Gas bubbles may have biochemical efects and disrupt the tissues or occlude the vessels with clinical and pathological signs and, in certain cases, death1. -
Dive Theory Guide
DIVE THEORY STUDY GUIDE by Rod Abbotson CD69259 © 2010 Dive Aqaba Guidelines for studying: Study each area in order as the theory from one subject is used to build upon the theory in the next subject. When you have completed a subject, take tests and exams in that subject to make sure you understand everything before moving on. If you try to jump around or don’t completely understand something; this can lead to gaps in your knowledge. You need to apply the knowledge in earlier sections to understand the concepts in later sections... If you study this way you will retain all of the information and you will have no problems with any PADI dive theory exams you may take in the future. Before completing the section on decompression theory and the RDP make sure you are thoroughly familiar with the RDP, both Wheel and table versions. Use the appropriate instructions for use guides which come with the product. Contents Section One PHYSICS ………………………………………………page 2 Section Two PHYSIOLOGY………………………………………….page 11 Section Three DECOMPRESSION THEORY & THE RDP….……..page 21 Section Four EQUIPMENT……………………………………………page 27 Section Five SKILLS & ENVIRONMENT…………………………...page 36 PHYSICS SECTION ONE Light: The speed of light changes as it passes through different things such as air, glass and water. This affects the way we see things underwater with a diving mask. As the light passes through the glass of the mask and the air space, the difference in speed causes the light rays to bend; this is called refraction. To the diver wearing a normal diving mask objects appear to be larger and closer than they actually are.