Name: methane hydrate crystallization on sessile water droplets
Uploaded: 2021-05-26T15:00:00
Description: Watch this Scientific Journal Video about Methane Hydrate Crystallization on Sessile Water Droplets at JoVE.com

NASA 외생물학 보조금 80NSSC19K0477이 연구에 자금을 지원. 우리는 귀중한 토론을 윌리엄 웨이트와 니콜라스 에스피노자 감사합니다.

1. 압력 셀을 설계, 검증 및 가공합니다.
<ol><li>물방울에서 수화물 형성의 직접 시각화를 허용하도록 셀을 설계합니다. 셀에 시스루 사파이어 창이 있는 주 챔버와 유체/가스 입구, 출구, 빛 및 전선용 4개의 포트가 있는지 확인합니다(그림1). 엔지니어링 설계소프트웨어(보충 도면 S1)에서최종 설계를 작성합니다.</li>
	<li>압력 셀이 고압 작업 하에서 안전한지 확?...

<ol>
	<li>Bohrmann, G., Torres, M. E., Schulz, H. D., Zabel, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gas+hydrates+in+marine+sediments.">Gas hydrates in marine sediments.</a> Marine Geochemistry. , 481-512 (2006).</li><li>Ruppel, C. D., Kessler, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+interaction+of+climate+change+and+methane+hydrates.">The interaction of climate change and methane hydrates.</a> Reviews of Geophysics. 55 (1), 126-168 (2017).</li><li>Hammerschmidt, E. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+gas+hydrates+in+natural+gas+transmission+lines.">Formation of gas hydrates in natural gas transmission lines.</a> Industrial and Engineering Chemistry. 26, 851-855 (1934).</li><li>Ke, W., Kelland, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetic+hydrate+inhibitor+studies+for+gas+hydrate+systems:+a+review+of+experimental+equipment+and+test+methods.">Kinetic hydrate inhibitor studies for gas hydrate systems: a review of experimental equipment and test methods.</a> Energy &amp; Fuels. 30 (12), 10015-10028 (2016).</li><li>Kelland, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+kinetic+hydrate+inhibitors+from+an+environmental+perspective.">A review of kinetic hydrate inhibitors from an environmental perspective.</a> Energy &amp; Fuels. 32 (12), 12001-12012 (2018).</li><li>Walker, V. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antifreeze+proteins+as+gas+hydrate+inhibitors.">Antifreeze proteins as gas hydrate inhibitors.</a> Canadian Journal of Chemistry. 93 (8), 839-849 (2015).</li><li>Bruusgaard, H., Lessard, L. D., Servio, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphology+study+of+structure+I+methane+hydrate+formation+and+decomposition+of+water+droplets+in+the+presence+of+biological+and+polymeric+kinetic+inhibitors.">Morphology study of structure I methane hydrate formation and decomposition of water droplets in the presence of biological and polymeric kinetic inhibitors.</a> Crystal Growth &amp; Design. 9 (7), 3014-3023 (2009).</li><li>Jung, J. W., Espinoza, D. N., Santamarina, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Properties+and+phenomena+relevant+to+CH4-CO2+replacement+in+hydrate-bearing+sediments.">Properties and phenomena relevant to CH4-CO2 replacement in hydrate-bearing sediments.</a> Journal of Geophysical Research. 115 (10102), 1-16 (2010).</li><li>Chen, X., Espinoza, D. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ostwald+ripening+changes+the+pore+habit+and+spatial+variability+of+clathrate+hydrate.">Ostwald ripening changes the pore habit and spatial variability of clathrate hydrate.</a> Fuel. 214, 614-622 (2018).</li><li>DuQuesnay, J. R., Diaz Posada, M. C., Beltran, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+gas+hydrate+reactor+design:+3-in-1+assessment+of+phase+equilibria,+morphology+and+kinetics.">Novel gas hydrate reactor design: 3-in-1 assessment of phase equilibria, morphology and kinetics.</a> Fluid Phase Equilibria. 413, 148-157 (2016).</li><li>Udegbunam, L. U., DuQuesnay, J. R., Osorio, L., Walker, V. K., Beltran, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phase+equilibria,+kinetics+and+morphology+of+methane+hydrate+inhibited+by+antifreeze+proteins:+application+of+a+novel+3-in-1+method.">Phase equilibria, kinetics and morphology of methane hydrate inhibited by antifreeze proteins: application of a novel 3-in-1 method.</a> The Journal of Chemical Thermodynamics. 117, 155-163 (2018).</li><li>Espinoza, D. N., Santamarina, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Water-CO2-mineral+systems:+Interfacial+tension,+contact+angle,+and+diffusion+-+Implications+to+CO2+geological+storage.">Water-CO2-mineral systems: Interfacial tension, contact angle, and diffusion - Implications to CO2 geological storage.</a> Water Resources Research. 46 (7537), 1-10 (2010).</li><li>Sloan, E. D., Koh, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Clathrate Hydrates of Natural Gases. 3rd edn. , (2007).</li><li>Makogon, I. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Hydrates of natural gas. , 125 (1981).</li><li>Johnson, A. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mainly+on+the+plane:+deep+subsurface+bacterial+proteins+bind+and+alter+clathrate+structure.">Mainly on the plane: deep subsurface bacterial proteins bind and alter clathrate structure.</a> Crystal Growth &amp; Design. 20 (10), 6290-6295 (2020).</li></ol>

우리는 세실 물방울에 메탄 수화물 껍질을 안전하게 형성하고 10 MPa 작동 압력뿐만 아니라 가압 및 냉각 시스템에 정격 된 압력 셀을 기계화하고 조립하는 방법을 공유하는 방법을 개발했습니다. 압력 셀에는 임베디드 열전대를 포함하는 액적, 액적 시각화를 위한 사파이어 창 및 셀 상단에 고정된 압력 변환기가 장착되어 있습니다. 냉각 시스템에는 압력 셀이 배치되는 50% 에탄올 용액이 있는 탱?...

가스 수화물은 반 데르 발스 상호 작용을 통해 게스트 가스 분자를 트랩 수소 결합 물 분자의 케이지입니다. 메탄 수화물은 고압 및 저온 조건 하에서 형성되며, 이는 대륙 의 여백을 따라, 북극 퍼머프로스트 아래, 그리고 태양계1의다른 행성 체에서 자연에서 발생하는 다. 가스 수화물은 기후와 에너지2에중요한 영향을 미치는 수천 기가톤의 탄소를 저장합니다. 가스 수화물은 가스 파이프라인에서 수화물에 유리한 조건이 발생하므로 천연가스 산업에서도 위험할 수 있으며, 이로 인해 파이프가 막히면 치명적인 폭발과 기름유출3가발생할 수 있습니다.
시투에서가스 수화물을 연구하는 데 어려움을 가지므로 실험실 실험은 종종 수화물 특성과 억제제 및기판4의 영향을 특성화하기 위해 사용됩니다. 이러한 실험실 실험은 다양한 모양과 크기의 세포에서 높은 압력에서 가스 수화를 증가시킴으로써 수행됩니다. 가스 파이프라인에서 가스 수화물 형성을 방지하기 위한 노력으로 인해 부동액 단백질(AFP), 계면활성제, 아미노산 및 폴리비닐피로돈(PVP)5,6을포함한 여러 화학 및 생물학적 가스 수화물 억제제의 발견이 이루어졌습니다. 이러한 화합물이 가스 수화물 특성에 미치는 영향을 확인하기 위해 이러한 실험은 오토클레이브, 결정화기, 교반 반응기 및 흔들리는 세포를 포함한 다양한 용기 설계를 사용했으며, 이는 0.2 내지 106 입방 센티미터4의부피를 지원합니다.
본 전연구에서 사용되는 세실 물방울 방법은7,8,9,10,11,12에서 압력 셀 내부의 물의 세슬액 액적에 가스 수화물 필름을 형성하는 것을 포함한다. 이 선박은 최대 10-20 MPa의 압력을 수용하기 위해 스테인레스 스틸과 사파이어로 만들어집니다. 셀은 메탄 가스 실린더에 연결됩니다. 이들 중 2개는 PVP7,11과같은 상업적 운동 수화물 억제제(KHI)에 비해 가스 수화물 억제제로서 AFP를 테스트하기 위해 액적 방법을 사용했다. 브루스가드 외7은 억제제의 형태학적 영향에 초점을 맞추고, 타입 I AF를 함유하는 액적들이 높은 구동력에서 억제제 없이 수지상 액적 표면보다 부드럽고 유리표면이 있다는 것을 발견했다.
Udegbunam외. 11은 이전연구에서KHI를 평가하기 위해 개발된 방법을 사용했으며, 이는 형태/성장 메커니즘, 수화-액체 증기 평형 온도/압력, 및 운동학을 온도의 함수로서 분석할 수 있도록 한다. 정외는 CH4-CO2 교체를 연구하여 CH4 수화 쉘8을형성한 후CO2로 세포를 범람시킴으로써 연구했다. 첸 외. 수화물 껍질 형태로 익는 오스트발트 관찰9. 에스피노자 외는 다양한 미네랄기판(12)에대한CO2 수화물 껍질을 연구했다. 상기 액적 방법은 가스 수화물에 대한 다양한 화합물 및 기판의 형태학적 효과를 결정하는 비교적 간단하고 저렴한 방법이며 소량의 첨가제가 적은 부피로 인해 요구된다. 이 논문은 최대 10MPa 작동 압력등급의 시각화를 위한 사파이어 창이 있는 스테인리스 스틸 셀을 사용하여 물방울에 이러한 수화물 쉘을 형성하는 방법을 설명합니다.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>CAMERA AND LAPTOP</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Camera Body</td>
			<td>Nikon</td>
			<td>D7200</td>
			<td>Name in Protocol: camera</td>
		</tr>
		<tr>
			<td>Camera Control Pro 2 Software</td>
			<td>Nikon</td>
			<td></td>
			<td>Name in Protocol: camera software</td>
		</tr>
		<tr>
			<td>Laptop</td>
			<td>HP Pavilion</td>
			<td>hp-pavilion-laptop-14-ce0068st</td>
			<td>Needs to be PC with plenty of storage (~ 1 Tb) 
			Name in Protocol: laptop</td>
		</tr>
		<tr>
			<td>Macrophotography Lens</td>
			<td>Nikon</td>
			<td>AF-S MICRO 105mm f/2.8G IF-ED Lens</td>
			<td>Name in Protocol: lens</td>
		</tr>
		<tr>
			<td>CONSUMABLES</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Deionized water</td>
			<td></td>
			<td></td>
			<td>Name in Protocol: DI water</td>
		</tr>
		<tr>
			<td>Dry Ice</td>
			<td>VWR or grocery store</td>
			<td></td>
			<td>Buy just before nucleation 
			Name in Protocol: dry ice</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td></td>
			<td></td>
			<td>Name in Protocol: ethanol</td>
		</tr>
		<tr>
			<td>Ethylene Glycol</td>
			<td></td>
			<td></td>
			<td>Name in Protocol: ethylene glycol</td>
		</tr>
		<tr>
			<td>COOLING SYSTEM</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1/2 in. O.D. x 3/8 in. I.D. x 25 ft. Polyethylene Tubing</td>
			<td>Everbilt</td>
			<td>Model # 301844</td>
			<td>For circulating coolant from chiller to copper coils in aquarium 
			Name in Protocol: 3/8&#8221; (inner diameter) plastic tubing</td>
		</tr>
		<tr>
			<td>Circulating chiller</td>
			<td>Polyscience</td>
			<td></td>
			<td>Name in Protocol: chiller</td>
		</tr>
		<tr>
			<td>Economical Flexible Polyethylene Foam Pipe Insulation</td>
			<td>McMaster-Carr</td>
			<td>4530K162</td>
			<td>3/4&#34; thick wall; 1/2&#34; inner diameter; R Value 3; 6&#39; long 
			Name in Protocol: foam pipe insulation</td>
		</tr>
		<tr>
			<td>Plastic tubing</td>
			<td></td>
			<td></td>
			<td>use any tubing that fits the airline connection in the lab and long enough to travel from the airline connection to the front of the aquarium</td>
		</tr>
		<tr>
			<td>DATALOGGER</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Armature Multiplexer Module for 34970A/ 
			34972A, 20-Channel</td>
			<td>Keysight Technologies</td>
			<td>34901A</td>
			<td>Name in Protocol: datalogger multichannel</td>
		</tr>
		<tr>
			<td>Benchvue or Benchlink software</td>
			<td>Benchvue or Benchlink</td>
			<td></td>
			<td>Name in Protocol: temperature transducer software</td>
		</tr>
		<tr>
			<td>Data Acquisition/Switch Unit. GPIB, RS232</td>
			<td>Keysight Technologies</td>
			<td>34970A</td>
			<td>Name in Protocol: datalogger</td>
		</tr>
		<tr>
			<td>USB/GPIB interface</td>
			<td>Keysight Technologies</td>
			<td>82357B</td>
			<td>Name in Protocol: datalogger USB</td>
		</tr>
		<tr>
			<td>datalogger multichannel</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Schott Fostec -Llc 20510 Ace Fiber Optic Light Source</td>
			<td>Schott Fostec</td>
			<td>A20500</td>
			<td>3115PS-12W-B20 115 V ~AC 50/60Hz 5/4.5 W 
			Name in Protocol: light source unit</td>
		</tr>
		<tr>
			<td>Schott Fostec light source guide - single bundle</td>
			<td>Schott Fostec</td>
			<td>A08031.40</td>
			<td>Name in Protocol: fiber optic light source cable</td>
		</tr>
		<tr>
			<td>METHANE GAS AND REGULATOR</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1/4 OD in. x 20 ft. Copper Soft Refrigeration Coil</td>
			<td>Everbilt</td>
			<td>Model # D 04020PS</td>
			<td>For pressurizing ISCO pressure pump. An additional pack is needed for coolant circulation, as listed below. 
			Name in Protocol: high pressure-rated 1/4&#8221; copper pipe</td>
		</tr>
		<tr>
			<td>Methane cylinder regulator</td>
			<td>Airgas</td>
			<td>Y11N114G350-AG</td>
			<td>Name in Protocol: methane cylinder regulator</td>
		</tr>
		<tr>
			<td>Methane gas cylinder</td>
			<td>Airgas</td>
			<td>ME UHP300</td>
			<td>Name in Protocol: methane gas cylinder</td>
		</tr>
		<tr>
			<td>PRESSURE PUMP</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1/4 in.&#160; flexible tubing, ~ 3 ft.</td>
			<td></td>
			<td></td>
			<td>Connect to pump inlet for leak test 
			Name in Protocol: 1/4&#34;&#160; flexible tubing</td>
		</tr>
		<tr>
			<td>260D Syringe Pump W/Controller</td>
			<td>Teledyne Instruments Inc.</td>
			<td>67-1240-520</td>
			<td>Name in Protocol: pressure pump</td>
		</tr>
		<tr>
			<td>Controller &#8722; Ethernet/USB</td>
			<td>Teledyne Instruments Inc.</td>
			<td>62-1240-114</td>
			<td>Purchase if you would like to install Labview onto computer and control pressure pump remotely. We did not do this.</td>
		</tr>
		<tr>
			<td>Smooth-Bore Seamless 316 Stainless Steel Tubing, 1/4&#34; OD, 0.035&#34; Wall Thickness, 1 Foot Long (x5)</td>
			<td>McMaster-Carr</td>
			<td>89785K824</td>
			<td>Name in Protocol: 1/4&#34; pipe</td>
		</tr>
		<tr>
			<td>Smooth-Bore Seamless 316 Stainless Steel Tubing, 1/8&#34; OD, 0.02&#34; Wall Thickness, 1 Foot Long (x4)</td>
			<td>McMaster-Carr</td>
			<td>89785K811</td>
			<td>Name in Protocol: 1/8&#34; pipe</td>
		</tr>
		<tr>
			<td>Stainless Steel Swagelok Tube Fitting, Reducing Union, 1/4 in. x 1/8 in. Tube OD (x4)</td>
			<td>Swagelok</td>
			<td>&#160;SS-400-6-2</td>
			<td>Name in Protocol: 1/8&#8221; to 1/4&#8221; adapter</td>
		</tr>
		<tr>
			<td>PRESSURE CELL</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>316 Stainless Steel Nut and Ferrule Set (1 Nut/1 Front Ferrule/1 Back Ferrule) for 1/4 in. Tube Fitting (20)</td>
			<td>Swagelok</td>
			<td>&#160;SS-400-NFSET</td>
			<td>Used for fitting connections where necessary 
			Name in Protocol: ferrule set</td>
		</tr>
		<tr>
			<td>316L Stainless Steel Convoluted (FM) Hose, 1/4 in., 316L Stainless Steel Braid, 1/4 in. Tube Adapters, 60 in. (1.5 m) Length</td>
			<td>Swagelok</td>
			<td>SS-FM4TA4TA4-60</td>
			<td>Connects pressure pump to pressure cell 
			Name in Protocol: 1/4&#34; braided stainless steel flexible pressure-rated hose</td>
		</tr>
		<tr>
			<td>ABAQUS</td>
			<td>ABAQUS FEA</td>
			<td></td>
			<td>Name in Protocol: simulation software</td>
		</tr>
		<tr>
			<td>Abrasion-Resistant Cushioning Washer for 7/8&#34; Screw Size, 0.875&#34; ID, 2.25&#34; OD, packs of 10 (x1)</td>
			<td>McMaster-Carr</td>
			<td>90131A107</td>
			<td>Name in Protocol: 2.25&#34; rubber washer</td>
		</tr>
		<tr>
			<td>Abrasion-Resistant Sealing Washer, Aramid Fabric/Buna-N Rubber, 3/8&#34; Screw Size, 0.625&#34; OD, packs of 10 (x1)</td>
			<td>McMaster-Carr</td>
			<td>93303A105</td>
			<td>Used for illumination port</td>
		</tr>
		<tr>
			<td>Acrylic Sheet | White 2447 / WRT31 
			Extruded Paper-Masked (Translucent 55% (0.118 x 12 x 12)</td>
			<td>Interstate Plastics</td>
			<td>ACRW7EPSH</td>
			<td>Machine a circle of acrylic to fit in the inner chamber of the pressure cell to serve as the background for imaging 
			Name in Protocol: acrylic disc</td>
		</tr>
		<tr>
			<td>AutoCAD</td>
			<td>AutoCAD</td>
			<td></td>
			<td>Name in Protocol: engineering design software</td>
		</tr>
		<tr>
			<td>Conax fitting</td>
			<td>Conax Technologies</td>
			<td>311401-011</td>
			<td>TG(PTM2/)-24-A6-T, OPTIONAL 1/4&#34; NPT 
			Name in Protocol: pressure seal connector</td>
		</tr>
		<tr>
			<td>High Accuracy Oil Filled Pressure 
			Transducers/Transmitters for General 
			industrial applications (x2)</td>
			<td>Omega Engineering, Inc.</td>
			<td>PX409-3.5KGUSBH</td>
			<td>Buy two so there is a backup. 
			Name in Protocol: pressure transducer</td>
		</tr>
		<tr>
			<td>HIGH PRESSURE CHAMBER&#160; PARTS</td>
			<td>Wither Tool, Die and Manufacturing Company</td>
			<td></td>
			<td>Machining for pressure cell parts as listed in CAD drawings (Figure S1) 
			Name in Protocol: Part B = stainless steel washer</td>
		</tr>
		<tr>
			<td>High-Strength 316 Stainless Steel Socket Head Screw, M5 x 0.80 mm Thread, 14 mm Long (x20)</td>
			<td>McMaster-Carr</td>
			<td>90037A119</td>
			<td>Used for illumination port</td>
		</tr>
		<tr>
			<td>High-Strength 316 Stainless Steel Socket Head Screw, M8 x 1.25 mm Thread, 25 mm Long (x20)</td>
			<td>McMaster-Carr</td>
			<td>90037A133</td>
			<td>Name in Protocol: M8 stainless steel screws</td>
		</tr>
		<tr>
			<td>Oil-Resistant Hard Buna-N O-Ring, 3/32 Fractional Width, Dash Number 120, packs of 50 (x1)</td>
			<td>McMaster-Carr</td>
			<td>5308T178</td>
			<td>Name in Protocol: 1&#34; o-ring</td>
		</tr>
		<tr>
			<td>Oil-Resistant Hard Buna-N O-Ring, 3/32 Fractional Width, Dash Number 128, packs of 50 (x1)</td>
			<td>McMaster-Carr</td>
			<td>5308T186</td>
			<td>Name in Protocol: 1.5&#34; o-ring</td>
		</tr>
		<tr>
			<td>Omega Inc. pressure transducer software</td>
			<td>Omega Engineering, Inc.</td>
			<td></td>
			<td>Name in Protocol: pressure transducer software</td>
		</tr>
		<tr>
			<td>Polycarbonate Disc</td>
			<td>McMaster-Carr</td>
			<td>8571K31</td>
			<td>Listed in CAD drawings for illumination port, Fig. S1 Part E</td>
		</tr>
		<tr>
			<td>Sapphire windows (x3)</td>
			<td>Guild Optical Associates, Inc.</td>
			<td>Optical Grade Sapphire Window, C-Plane 
			Diameter: 1.811&#8221; &#177;.005&#8221; 
			Thickness: .590&#8221; &#177;.005&#8221; 
			Surface Quality: 60/40 
			Edges ground and safety chamfered</td>
			<td>Buy three so there are two backups. 
			Name in Protocol: sapphire window</td>
		</tr>
		<tr>
			<td>Solid Thermocouple Wire FEP Insulation and Jacket, Type K, 24 Gauge, 50 ft. Length (x1)</td>
			<td>McMaster-Carr</td>
			<td>3870K32</td>
			<td>Name in Protocol: thermocouples</td>
		</tr>
		<tr>
			<td>Stainless Steel Integral Bonnet Needle Valve, 0.37 Cv, 1/4 in. Swagelok Tube Fitting, Regulating Stem (x4)</td>
			<td>Swagelok</td>
			<td>&#160;SS-1RS4</td>
			<td>Two will be used for the pressure pump as well. 
			Name in Protocol: 1/4&#34; needle valves</td>
		</tr>
		<tr>
			<td>Stainless Steel Pipe Fitting, Hex Nipple, 1/4 in. Male NPT (x2)</td>
			<td>Swagelok</td>
			<td>&#160;SS-4-HN</td>
			<td>Used for illumination port</td>
		</tr>
		<tr>
			<td>Stainless Steel Swagelok Tube Fitting, Female Branch Tee, 1/4 in. Tube OD x 1/4 in. Tube OD x 1/4 in. Female NPT (x2)</td>
			<td>Swagelok</td>
			<td>&#160;SS-400-3-4TTF</td>
			<td>Used with pressure transducer 
			Name in Protocol: branch tee fitting</td>
		</tr>
		<tr>
			<td>Stainless Steel Swagelok Tube Fitting, Male Connector, 1/4 in. Tube OD x 1/4 in. Male NPT (x4)</td>
			<td>Swagelok</td>
			<td>&#160;SS-400-1-4</td>
			<td>Used on top port and side port leading to needle valves 
			Name in Protocol: NPT screws</td>
		</tr>
		<tr>
			<td>Stainless Steel Swagelok Tube Fitting, Port Connector, 1/4 in. Tube OD (x8)</td>
			<td>Swagelok</td>
			<td>&#160;SS-401-PC</td>
			<td>Use as tube connections between NTP and valve connections 
			Name in Protocol: port connector fitting</td>
		</tr>
		<tr>
			<td>TANK</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1/4 OD in. x 20 ft. Copper Soft Refrigeration Coil</td>
			<td>Everbilt</td>
			<td>Model # D 04020PS</td>
			<td>For circulating coolant 
			Name in Protocol: 1/4&#34; copper pipe</td>
		</tr>
		<tr>
			<td>10 gallon aquarium</td>
			<td>Tetra</td>
			<td></td>
			<td>Name in Protocol: 10 gallon tank</td>
		</tr>
		<tr>
			<td>2 oz. Waterweld</td>
			<td>J-B Weld</td>
			<td>Model # 8277</td>
			<td>Name in Protocol: underwater sealant</td>
		</tr>
		<tr>
			<td>3 in. x 25 ft. Foil Backed Fiberglass Pipe Wrap Insulation</td>
			<td>Frost King</td>
			<td>Model # SP42X/16</td>
			<td>For wrapping around aquarium 
			Name in Protocol: foil-lined fiberglass</td>
		</tr>
		<tr>
			<td>3/8 7/8 in. Stainless Steel Hose Clamp (10 pack)</td>
			<td>Everbilt</td>
			<td>Model # 670655E</td>
			<td>Name in Protocol: worm drive hose clamps</td>
		</tr>
		<tr>
			<td>Styrofoam</td>
			<td></td>
			<td></td>
			<td>Name in Protocol: insulating material</td>
		</tr>
		<tr>
			<td>TOOLS</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1-1/8 in. Ratcheting Tube Cutter</td>
			<td>Husky</td>
			<td>Model # 86-036-0111</td>
			<td></td>
		</tr>
		<tr>
			<td>1/2 in. to 1 in. Pipe Cutter</td>
			<td>Apollo</td>
			<td>Model # 69PTKC001</td>
			<td></td>
		</tr>
		<tr>
			<td>Adjustable wrench (x2)</td>
			<td>Steel Core</td>
			<td>Model # 31899</td>
			<td>Need two wrenches with jaw at least 1&#34;</td>
		</tr>
		<tr>
			<td>Allen wrench set</td>
			<td>Home Depot</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Duct tape</td>
			<td></td>
			<td></td>
			<td>Name in Protocol: duct tape</td>
		</tr>
		<tr>
			<td>Flexible tubing, like an IV line, to fit on the end of grainger probe (canula)</td>
			<td></td>
			<td></td>
			<td>Name in Protocol: IV tube</td>
		</tr>
		<tr>
			<td>Grainger 18 gauge probe</td>
			<td>Grainger</td>
			<td></td>
			<td>For inserting droplet 
			Name in Protocol: cannula</td>
		</tr>
		<tr>
			<td>High Vacuum Grease</td>
			<td>Dow corning</td>
			<td></td>
			<td>Apply to o-rings before inserting sapphire window 
			Name in Protocol: vacuum grease</td>
		</tr>
		<tr>
			<td>Klein Tools Professional 90 Degree 4-in-1 Tube Bender</td>
			<td>Klein Tools</td>
			<td>Model # 89030</td>
			<td>Name in Protocol: tube bender</td>
		</tr>
		<tr>
			<td>Snoop liquid leak detector</td>
			<td>Swagelok</td>
			<td>MS-SNOOP-8OZ</td>
			<td>To detect leaks when pressurized when methane 
			Name in Protocol: liquid leak detector</td>
		</tr>
		<tr>
			<td>Suction cup</td>
			<td>Home Depot</td>
			<td></td>
			<td>For removing tight fitting sapphire window 
			Name in Protocol: suction cup</td>
		</tr>
		<tr>
			<td>Teflon Tape</td>
			<td></td>
			<td></td>
			<td>Name in Protocol: plumber&#39;s tape</td>
		</tr>
		<tr>
			<td>Temflex 3/4 in. x 60 ft. 1700 Electrical Tape Black</td>
			<td>3M</td>
			<td>Model # 1700-1PK-BB40</td>
			<td>Name in Protocol: electrical tape</td>
		</tr>
	</tbody>
</table>

methane hydrate crystallization on sessile water droplets

이 논문은 물방울에 메탄 수화물 껍질을 형성하는 방법을 설명합니다. 또한, 10MPa 작동 압력으로 정격된 압력 셀에 대한 청사진을 제공하며, 세실 방울의 스테이지, 시각화를 위한 사파이어 윈도우, 온도 및 압력 변환기를 포함합니다. 메탄 가스 실린더에 연결된 압력 펌프를 사용하여 셀을 5MPa로 가압합니다. 냉각 시스템은 구리 코일을 통해 에틸렌 글리콜을 통해 냉각된 50% 에탄올 용액을 함유한 10갤런(37.85 L) 탱크입니다. 이러한 설정은 각각 냉각 및 우울화 시 수화물 형성 및 해리와 관련된 온도 변화를 관찰할 뿐만 아니라 액적의 형태학적 변화의 시각화 및 사진 촬영을 가능하게 한다. 이 방법으로, 급속 수화물 껍질 형성은 ~-6°C에서 -9°C로 관찰되었다. 감압 시, 0.2°C ~ 0.5°C의 온도 낙하가 엑더믹 수화물 해리로 인한 압력/온도(P/T) 안정성 곡선에서 관찰되었으며, 온도 낙하시에 용융의 시각적 관찰에 의해 확인되었다. "메모리 효과"는 2MPa에서 5MPa로 억압 한 후 관찰되었다. 이 실험 설계를 통해 시간이 지남에 따라 액적의 압력, 온도 및 형태에 대한 모니터링을 통해 수화물 형태에 대한 다양한 첨가제 및 기판을 테스트하기에 적합한 방법입니다.

이 방법을 사용하면 액적의 가스 수화물 쉘을 압력 셀의 사파이어 창을 통해 온도 및 압력 트랜스듀서를 통해 시각적으로 모니터링할 수 있습니다. 5MPa로 가압한 후 수화물 껍질을 핵에 넣은 건조 빙상은 압력 세포의 상단에 첨가되어 급속히 수화 결정화를 유발하기 위해 열 충격을 유도할 수 있다. 드라이 아이스 강제 수화물 껍질 형성시 명확한 형태적 차이가 있습니다. 물방울은 부드럽고 반사?...

Watch this Scientific Journal Video about Methane Hydrate Crystallization on Sessile Water Droplets at JoVE.com

Methane Hydrate Crystallization on Sessile Water Droplets

우리는 수화물 결정 형태에 다양한 억제제, 프로모터 및 기판의 효과를 연구하기 위해 세실 물방울에 가스 수화물을 형성하는 방법을 설명합니다.

세실 물방울에 메탄 수화물 결정화

This paper describes a method to form methane hydrate shells on water droplets. In addition, it provides blueprints for a pressure cell rated to 10 MPa ...

가스 수화물 형태와 압력 온도 안정성에 대한 다양한 첨가제의 효과를 테스트할 수 있습니다. 그러나 주요 관심사는 생체 분자가 어떻게 상호 작용하고 그 중심에 있는 가스 수화물에 영향을 미칠 수 있는지 알아내는 것입니다. 이 프로토콜의 주요 장점은 세실 액적에 수화물 쉘을 안전하게 형성할 수 있다는 것입니다.방울 스테이지를 평준화하는 것은 어렵고, 물방울이 고르지 않은 무대에서 미끄러지기 때문에 연습이 필요합니다. 또한, 고압 인화성 가스에 대한 Swagelok 연결 및 안전에 익숙합니다. 먼저 메탄 실린더 레귤레이터를 펌프에 새로운 너트 및 ferrule 세트를 사용하여 1-4인치 구리 파이프를 연결합니다.IV 튜브의 유연한 팁을 접착제, 각도를 잘라, 사파이어 창쪽으로 방울을 지시하는 데 도움이 캐뉼라의 끝에. 캐뉼라에 밀리리터 주사기를 1밀리리터 주사기를 부착하고 원하는 양의 탈온화된 물을 가져옵니다. 바늘 밸브 나 사파이어 창이 부착되지 않고, 상단 보드에 캐뉼라의 끝을 삽입하고 중앙 단계에 방울을 추방 연습.Sapphire 창과 와셔를 M8 나사로 다시 연결하고 최고 압력 셀 밸브를 부착합니다. 압력 펌프에서 압력 셀에 편조 된 스테인레스 스틸 호스를 연결합니다. 그리고 가스 실린더에서 압력 셀에 이르는 모든 연결이 타이트하다는 것을 다시 확인하십시오.압력 셀 입구 밸브를 열고 수족관에 압력 셀을 설정합니다. 그런 다음 광섬유 광원 케이블을 압력 셀 조명 포트에 삽입합니다. 에탄올과 물의 50/50 비율로 채워진 수족관에서, 다음 주에 용액 레벨이 떨어지면 광원 연결 바로 아래 압력 셀의 상단과 레벨이 될 때까지 에탄올을 더 추가합니다.냉각기를 셀 내부의 섭씨 약 0~3도까지 달성하고 코일을 통해 순환하기 시작하는 온도로 설정합니다. 수족관 표면의 응축을 방지하기 위해 수족관 의 전면에 공기 흐름을 켭니다. 데이터 로거 소프트웨어에서 온도 로그를 시작합니다.스캐닝 간격을 30초로 설정하고 압력 셀 내부의 온도가 섭씨 2도에서 안정될 때까지 기다립니다. 카메라를 놓은 후 광원을 약 80%로 켜고 카메라 소프트웨어를 엽니다. Live View에서 카메라 렌즈를 셀 내부 챔버에 집중하고 광원을 조정하여 최상의 이미징을 제공합니다.1초 스캔 간격으로 새 온도 로그를 시작합니다. 부착된 경우 압력 셀의 상단 포트에 콘센트 바늘 밸브를 분리합니다. 캐뉼라에 밀리리터 주사기를 1밀리리터 주사기를 부착하고 원하는 양의 탈온화된 물을 가져옵니다.라이브 뷰 모드에서 카메라 소프트웨어에 팁이 표시될 때까지 상단 보드를 통해 캐뉼라를 삽입합니다. 주사기에서 중앙 열전대 위로 유체 방울을 배출합니다. 그런 다음 바늘 밸브를 다시 부착합니다.압력 셀의 액적에 카메라를 집중합니다. 60초마다 시간 경과 이미징을 시작합니다. 노트북에서 압력 변환기 소프트웨어를 엽니다.차트에서 데이터 수집을 시작하고 1초의 스캔 간격으로 데이터 로그를 수집하고 물방울 온도가 섭씨 0~3도 사이에 안정될 때까지 기다립니다. 펌프와 컨트롤러를 켭니다. 압력 펌프의 입구 밸브를 닫습니다.펌프의 콘센트 밸브와 압력 셀의 밸브를 엽니다. 압력 펌프 컨트롤러에 0을 눌러 펌프 압력을 타수하십시오. 압력 펌프 컨트롤러에서 펌프 A를 선택하여 압력을 모니터링합니다.메탄 가스 이외의 다른 유체가 펌프에 존재하는 경우 압력 펌프가 비어 있는지 확인합니다. 최대 흐름과 일정한 흐름을 분당 100 밀리리터로 설정하고 Run을 눌러 이 작업을 수행합니다. 펌프가 비어 있는 때까지 실행 상태로 둡니다.펌프 콘센트 밸브를 닫고 펌프 입구 밸브를 엽니다. 가스 실린더를 열고 가스 실린더 레귤레이터를 1, 000 킬로파스칼으로 설정합니다. 압력 펌프 컨트롤러에 리필을 누릅니다.펌프가 가득 차면 1, 000 킬로파스칼 근처에 펌프 입구 밸브와 가스 실린더를 닫습니다. 펌프 콘센트 밸브를 셀에 약간 엽니다. 압력 전지의 상대적으로 낮은 온도로 인해 감소될 수 있으므로 압력 트랜스듀서 소프트웨어에서 압력 셀 압력을 모니터링합니다.최대 흐름을 분당 10밀리리터로 설정하고 최대 압력은 5, 000 킬로파스칼으로 설정하고 텍스트 원고에 설명된 압력 펌프 컨트롤러에 1, 000 킬로파스칼으로 일정한 압력을 설정합니다. 실행 을 누릅니다. 1, 000 킬로파스칼에 도달하면 펌프 컨트롤러에서 중지를 누르고 펌프의 콘센트 밸브를 닫습니다.압력 셀의 압력을 모니터링하여 누출이 없는지 확인합니다. 압력이 떨어지면 액체 누출 감지기를 사용하여 연결에서 누출을 발견하고 누출 성분을 조심스럽게 조입니다. 셀이 안정되면 펌프 콘센트를 열고 일정한 압력을 2, 000, 3, 000, 4, 000 및 5, 000 킬로파스칼로 점진적으로 설정하여 각 설정 후 정지를 눌러 셀 안정성을 모니터링합니다.압력이 안정되면 펌프 콘센트를 닫고 가스가 물방울에 침투할 때까지 약 12~24시간 기다립니다. 시간 경과를 전환하여 2~5초마다 이미지를 찍습니다. 수화물 껍질이 시간 경과에 보일 때까지 셀 상단에 드라이 아이스를 추가합니다.드라이 아이스가 미끄러지면 셀 상단 주위에 테이프를 부착합니다. 시간 경과 사진을 통해 메탄 수화물 형성의 진행 상황을 관찰하여 2~6시간 동안 관찰한다. 펌프 콘센트를 열고 일정한 압력을 2, 000 킬로파스칼으로 설정하여 세포를 2, 000 킬로파스칼으로 우울하게 하여 용융시 주목하십시오.30분 후 압력 셀을 5, 000 킬로파스칼으로 억압하여 메모리 효과를 관찰합니다. 수화물 쉘이 개혁하기 시작하고 쉘이 30분에서 2시간 동안 형성되도록 할 때 유의하십시오. 펌프 콘센트를 열고 일정한 압력을 100 킬로파스칼로 설정하여 셀을 우울하게 합니다.압력 셀에 잔류 압력이 있는 경우 압력 셀 상단 밸브를 1/16 인치 로 약간 엽니다. 압력 및 온도 데이터를 CSV 파일로 저장합니다. 상단 압력 세포 밸브를 제거하고 주사기, 캐뉼라 또는 IV 튜브로 액적을 추출하여 액적을 제거합니다.시험 간 오염에 대한 우려가 있는 경우 텍스트 원고의 지침을 따르십시오. 드라이 아이스강제 수화물 껍질 형성시 명확한 형태적 차이가 있는데, 물방울은 부드러운 반사 표면에서 약간의 수지상 표면을 가진 불투명한 수화물 쉘로 전환합니다. 1형 부동액 단백질에 밀리리터당 100마이크로그램을 첨가하여 액적 상단의 물방울과 돌출부를 따라 능선 가장자리를 유도하여 수화물 형태를 변화시켰습니다.수화물 껍질이 1시간 동안 개발된 후, 세포는 2개의 메가파스칼로 우울하여 P/T 안정성 곡선 근처의 온도에서 섭씨 2~5도 하락했습니다. 수화 절제로 인해 수화해리는 온도 가의 초기에 타임랩스 이미징을 통해 시각적으로 녹는 것으로 확인되었다. 물방울이 없고 수화물 껍질을 형성하지 않은 액적으로 음의 대조군으로 우울화 시 온도가 감소하지 않았습니다.각 온도도의 정점은 이전에 확립된 P/T 안정성 곡선보다 높았기 때문에 이러한 시험의 정점 P/T를 기준으로 회귀 곡선을 계산했습니다. 이 프로토콜을 수행할 때 두 가지 를 염두에 두는 것이 중요합니다. 하나는 가압하기 전에 모든 연결이 안전한지 확인하고 두 개는 사파이어 창을 부착하기 전에 물방울을 추방하는 연습을 합니다.이 프로토콜에 따라, 하나는 가스 소비를 계산하고 형성 된 수화물의 양을 결정하기 위해 수화물 쉘 두께를 계산하기 위해 이미지를 분석 할 수 있습니다.

methane-hydrate-crystallization-on-sessile-water-droplets

Research

JoVE Journal

Environment

Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading

Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) loading from lake sediments can account for a substantial portion of the total P load in eutrophic, and some mesotrophic, lakes. Laboratory determination of P release rates from sediment cores is one approach for determining the role of internal P loading and guiding management decisions. Two principal alternatives to experimental determination of sediment P release exist for estimating internal load: in situ measurements of changes in hypolimnetic P over time and P mass balance. The experimental approach using laboratory-based sediment incubations to quantify internal P load is a direct method, making it a valuable tool for lake management and restoration.
Laboratory incubations of sediment cores can help determine the relative importance of internal vs. external P loads, as well as be used to answer a variety of lake management and research questions. We illustrate the use of sediment core incubations to assess the effectiveness of an aluminum sulfate (alum) treatment for reducing sediment P release. Other research questions that can be investigated using this approach include the effects of sediment resuspension and bioturbation on P release.
The approach also has limitations. Assumptions must be made with respect to: extrapolating results from sediment cores to the entire lake; deciding over what time periods to measure nutrient release; and addressing possible core tube artifacts. A comprehensive dissolved oxygen monitoring strategy to assess temporal and spatial redox status in the lake provides greater confidence in annual P loads estimated from sediment core incubations.

Lake eutrophication is a water quality issue worldwide, making the need to identify and control nutrient sources critical. Laboratory determination of phosphorus release rates from sediment cores is a valuable approach for determining the role of internal phosphorus loading and guiding management decisions.

호수 퇴적물에서 실험실 결정 인 플럭스 내부 인 로딩의 측정으로

Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) ...

연구

환경과학

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. I. Collection of Virus Samples

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. The standardized sampling component of the method concentrates viruses that may be present in water by passage of a minimum specified volume of water through an electropositive cartridge filter. The minimum specified volumes for surface and finished/ground water are 300 L and 1,500 L, respectively. A major method limitation is the tendency for the filters to clog before meeting the sample volume requirement. Studies using two different, but equivalent, cartridge filter options showed that filter clogging was a problem with 10% of the samples with one of the filter types compared to 6% with the other filter type. Clogging tends to increase with turbidity, but cannot be predicted based on turbidity measurements only. From a cost standpoint one of the filter options is preferable over the other, but the water quality and experience with the water system to be sampled should be taken into consideration in making filter selections.

EPA Method 1615 uses an electropositive filter to concentrate enteroviruses and noroviruses in environmental and drinking waters. This manuscript describes the procedure for collecting samples for Method 1615 analyses.

엔테로 바이러스 및 문화 RT-qPCR에 의해 물에서 노로 바이러스의 발생의 EPA 방법 1615 측정. 바이러스 샘플의 I. 컬렉션

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. ...

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. Part III. Virus Detection by RT-qPCR

EPA Method 1615 measures enteroviruses and noroviruses present in environmental and drinking waters. This method was developed with the goal of having a standardized method for use in multiple analytical laboratories during monitoring period 3 of the Unregulated Contaminant Monitoring Rule. Herein we present the protocol for extraction of viral ribonucleic acid (RNA) from water sample concentrates and for quantitatively measuring enterovirus and norovirus concentrations using reverse transcription-quantitative PCR (RT-qPCR). Virus concentrations for the molecular assay are calculated in terms of genomic copies of viral RNA per liter based upon a standard curve. The method uses a number of quality controls to increase data quality and to reduce interlaboratory and intralaboratory variation. The method has been evaluated by examining virus recovery from ground and reagent grade waters seeded with poliovirus type 3 and murine norovirus as a surrogate for human noroviruses. Mean poliovirus recoveries were 20% in groundwaters and 44% in reagent grade water. Mean murine norovirus recoveries with the RT-qPCR assay were 30% in groundwaters and 4% in reagent grade water.

Here we present a procedure to quantify enterovirus and norovirus in environmental and drinking waters using reverse transcription-quantitative PCR. Mean virus recovery from groundwater with this standardized procedure from EPA Method 1615 was 20% for poliovirus and 30% for murine norovirus.

엔테로 바이러스 및 문화와 RT-qPCR에 의해 물에서 노로 바이러스의 발생의 EPA 방법 1615 측정. 파트 III. RT-qPCR에 의한 바이러스 검출

EPA Method 1615 measures enteroviruses and noroviruses present in environmental and drinking waters. This method was developed with the goal of having a ...

A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function

Continuing increases in atmospheric carbon dioxide concentrations (CA) mandate techniques for examining impacts on terrestrial ecosystems. Most experiments examine only two or a few levels of CA concentration and a single soil type, but if CA can be varied as a gradient from subambient to superambient concentrations on multiple soils, we can discern whether past ecosystem responses may continue linearly in the future and whether responses may vary across the landscape. The Lysimeter Carbon Dioxide Gradient Facility applies a 250 to 500 &#181;l L-1 CA gradient to Blackland prairie plant communities established on lysimeters containing clay, silty clay, and sandy soils. The gradient is created as photosynthesis by vegetation enclosed in in temperature-controlled chambers progressively depletes carbon dioxide from air flowing directionally through the chambers. Maintaining proper air flow rate, adequate photosynthetic capacity, and temperature control are critical to overcome the main limitations of the system, which are declining photosynthetic rates and increased water stress during summer. The facility is an economical alternative to other techniques of CA enrichment, successfully discerns the shape of ecosystem responses to subambient to superambient CA enrichment, and can be adapted to test for interactions of carbon dioxide with other greenhouse gases such as methane or ozone.

A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function

The Lysimeter Carbon Dioxide Gradient Facility creates a 250 to 500 &#181;l L-1 linear carbon dioxide gradient in temperature-controlled chambers housing grassland plant communities on clay, silty clay, and sandy soil monoliths. The facility is used to determine how past and future carbon dioxide levels affect grassland carbon cycling.

CO<sub&gt; 2</sub테스트 주식에 대한&gt; 농도 구배 시설<sub&gt; 2</sub초원 생태계 기능에&gt; 농축 및 토양 효과

Continuing increases in atmospheric carbon dioxide concentrations (CA) mandate techniques for examining impacts on terrestrial ecosystems. Most ...

Protocol for Measuring the Thermal Properties of a Supercooled Synthetic Sand-water-gas-methane Hydrate Sample

Methane hydrates (MHs) are present in large amounts in the ocean floor and permafrost regions. Methane and hydrogen hydrates are being studied as future energy resources and energy storage media. To develop a method for gas production from natural MH-bearing sediments and hydrate-based technologies, it is imperative to understand the thermal properties of gas hydrates.
The thermal properties' measurements of samples comprising sand, water, methane, and MH are difficult because the melting heat of MH may affect the measurements. To solve this problem, we performed thermal properties' measurements at supercooled conditions during MH formation. The measurement protocol, calculation method of the saturation change, and tips for thermal constants' analysis of the sample using transient plane source techniques are described here.
The effect of the formation heat of MH on measurement is very small because the gas hydrate formation rate is very slow. This measurement method can be applied to the thermal properties of the gas hydrate-water-guest gas system, which contains hydrogen, CO2, and ozone hydrates, because the characteristic low formation rate of gas hydrate is not unique to MH. The key point of this method is the low rate of phase transition of the target material. Hence, this method may be applied to other materials having low phase-transition rates.

We present a protocol for measuring the thermal properties of synthetic hydrate-bearing sediment samples comprising sand, water, methane, and methane hydrate.

과냉각 합성 모래 - 물 - 가스 메탄 하이드레이트 샘플의 열적 특성을 측정하기위한 프로토콜

Methane hydrates (MHs) are present in large amounts in the ocean floor and permafrost regions. Methane and hydrogen hydrates are being studied as future ...

Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative in improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. We present an experimental method, designed to capture sub-surface heterogeneity of an initially homogeneous soil system. This method is based on destructive sampling of a soil lysimeter designed to simulate a small-scale hillslope. A weighing lysimeter of one cubic meter capacity was divided into sections (voxels) and was excavated layer-by-layer, with sub samples being collected from each voxel. The excavation procedure was aimed at detecting the incipient heterogeneity of the system by focusing on the spatial assessment of hydrological, geochemical, and microbiological properties of the soil. Representative results of a few physicochemical variables tested show the development of heterogeneity. Additional work to test interactions between hydrological, geochemical, and microbiological signatures is planned to interpret the observed patterns. Our study also demonstrates the possibility of carrying out similar excavations in order to observe and quantify different aspects of soil-development under varying environmental conditions and scale.

This study presents an excavation method for investigating subsurface hydrological, geochemical, and microbiological heterogeneity of a soil lysimeter. The lysimeter simulates an artificial hillslope which was initially under homogeneous condition and had been subjected to approximately 5,000 mm of water over eight cycles of irrigation in an 18-month period.

결합 문학, 지구 화학 및 미생물 조사를위한 토양 모형 매립 발굴

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled ...

Protocol for Microplastics Sampling on the Sea Surface and Sample Analysis

Microplastic pollution in the marine environment is a scientific topic that has received increasing attention over the last decade. The majority of scientific publications address microplastic pollution of the sea surface. The protocol below describes the methodology for sampling, sample preparation, separation and chemical identification of microplastic particles. A manta net fixed on an &#187;A frame&#171; attached to the side of the vessel was used for sampling. Microplastic particles caught in the cod end of the net were separated from samples by visual identification and use of stereomicroscopes. Particles were analyzed for their size using an image analysis program and for their chemical structure using ATR-FTIR and micro FTIR spectroscopy. The described protocol is in line with recommendations for microplastics monitoring published by the Marine Strategy Framework Directive (MSFD) Technical Subgroup on Marine Litter. This written protocol with video guide will support the work of researchers that deal with microplastics monitoring all over the world.

The protocol below describes the methodology for: microplastics sampling on the sea surface, separation of microplastic and chemical identification of particles. This protocol is in line with the recommendations for microplastics monitoring published by the MSFD Technical Subgroup on Marine Litter.

바다 표면 및 샘플 분석에 Microplastics 샘플링을위한 프로토콜

Microplastic pollution in the marine environment is a scientific topic that has received increasing attention over the last decade. The majority of ...

A Simple Planting Technique for Re-establishing Trees Where Frequent Inundation Occurs

Many of the Everglades tree islands have lost elevation over the past century and most of their trees have died such that they are now covered with herbaceous plants. This protocol describes a simple, cost-effective tree planting technique needed for restoring degraded Everglade tree islands. The design is patterned after a natural Everglades process that creates floating peat islands, which allows tree survival and growth in flooded conditions and often leads to the development of tree islands. Commercially available peat bags were used as the medium for the growth and establishment of potted native tree saplings. The pop-up configuration floated initially and provided additional elevation to minimize inundation, with a single native tree species sapling and a single tree fertilizer spike. During a 3 year study involving 105 pop-ups, most plants survived (80%) and many thrived. Determining whether this technique can establish trees on a degraded tree island will require longer studies and extensive field tests.

This protocol describes a simple, cost-effective tree planting technique for restoring degraded Everglades tree islands that experience inundation. The design creates an island (pop-up) which floats initially and adds elevation to promote tree survival and growth under flooded conditions.

간단한 다시 설정 나무에 대 한 기술을 설치 하 여 자주 침수 발생

Many of the Everglades tree islands have lost elevation over the past century and most of their trees have died such that they are now covered with ...

Experimental Study of the Relationship Between Particle Size and Methane Sorption Capacity in Shale

The amount of adsorbed shale gas is a key parameter used in shale gas resource evaluation and target area selection, and it is also an important standard for evaluating the mining value of shale gas. Currently, studies on the correlation between particle size and methane adsorption are controversial. In this study, an isothermal adsorption apparatus, the gravimetric sorption analyzer, is used to test the adsorption capacity of different particle sizes in shale to determine the relationship between the particle size and the adsorption capacity of shale. Thegravimetric method requires fewer parameters and produces better results in terms of accuracy and consistency than methods like the volumetric method. Gravimetric measurements are performed in four steps: a blank measurement, preprocessing, a buoyancy measurement, and adsorption and desorption measurements. Gravimetric measurement is presently considered to be a more scientific and accurate method of measuring the amount of adsorption; however, it is time-consuming and requires a strict measuring technique. A Magnetic Suspension Balance (MSB) is the key to verify the accuracy and consistency of this method. Our results show that adsorption capacity and particle size are correlated, but not a linear correlation, and the adsorptions in particles sieved into 40 - 60 and 60 - 80 meshes tend to be larger. We propose that the maximum adsorption corresponding to the particle size is approximately 250 &#181;m (60 mesh) in the shale gas fracturing.

We use an isothermal adsorption apparatus, the gravimetric sorption analyzer, to test the adsorption capacity of different particle sizes of shale, in order to find out the relationship between particle size and the adsorption capacity of shale.

입자 크기와 셰 일에서 메탄 수 착 용량 사이의 관계의 실험적 연구

The amount of adsorbed shale gas is a key parameter used in shale gas resource evaluation and target area selection, and it is also an important standard ...

Construction of a Low-cost Mobile Incubator for Field and Laboratory Use

Incubators are essential for a range of culture-based microbial methods, such as membrane filtration followed by cultivation for assessing drinking water quality. However, commercially available incubators are often costly, difficult to transport, not flexible in terms of volume, and/or poorly adapted to local field conditions where access to electricity is unreliable. The purpose of this study was to develop an adaptable, low-cost and transportable incubator that can be constructed using readily available components. The electronic core of the incubator was first developed. These components were then tested under a range of ambient temperature conditions (3.5 &#176;C - 39 &#176;C) using three types of incubator shells (polystyrene foam box, hard cooler box, and cardboard box covered with a survival blanket). The electronic core showed comparable performance to a standard laboratory incubator in terms of the time required to reach the set temperature, inner temperature stability and spatial dispersion, power consumption, and microbial growth. The incubator set-ups were also effective at moderate and low ambient temperatures (between 3.5 &#176;C and 27 &#176;C), and at high temperatures (39 &#176;C) when the incubator set temperature was higher. This incubator prototype is low-cost (&lt; 300 USD) and adaptable to a variety of materials and volumes. Its demountable structure makes it easy to transport. It can be used in both established laboratories with grid power or in remote settings powered by solar energy or a car battery. It is particularly useful as an equipment option for field laboratories in areas with limited access to resources for water quality monitoring.

This paper describes a method for building an adaptable, low-cost and transportable incubator for microbial testing of drinking water. Our design is based on widely available materials and can operate under a range of field conditions, while still offering the advantages of higher-end laboratory-based models.

분야와 실험실 사용을 위한 저비용 모바일 인큐베이터의 건설

Incubators are essential for a range of culture-based microbial methods, such as membrane filtration followed by cultivation for assessing drinking water ...