The authors wish to thank the Defence Science and Technology Laboratory for funding the published work.

<ol>
	<li>Esparza, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blast+measurements+and+equivalency+for+spherical+charges+at+small+scaled+distances.">Blast measurements and equivalency for spherical charges at small scaled distances.</a> Int. J. Impact Eng. 4 (1), 23-40 (1986).</li><li>Kingery, C. N., Bulmash, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ARBRL-TR-02555.">ARBRL-TR-02555.</a> Airblast parameters from TNT spherical air burst and hemispherical surface burst. , (1984).</li><li>Hyde, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Conventional weapons program (ConWep). , (1991).</li><li>Randers-Pehrson, G., Bannister, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ARL-TR-1310.">ARL-TR-1310.</a> Airblast loading model for DYNA2D and DYNA3D. , (1997).</li><li>Neuberger, A., Peles, S., Rittel, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scaling+the+response+of+circular+plates+subjected+to+large+and+close-range+spherical+explosions.+Part+II:+Buried+charges.">Scaling the response of circular plates subjected to large and close-range spherical explosions. Part II: Buried charges.</a> Int. J. Impact Eng. 34 (5), 874-882 (2007).</li><li>Xu, S., 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=An+inverse+approach+for+pressure+load+identification.">An inverse approach for pressure load identification.</a> Int. J. Impact Eng. 37 (7), 865-877 (2010).</li><li>Pickering, E. G., Chung Kim Yuen, S., Nurick, G. N., Haw, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+response+of+quadrangular+plates+to+buried+charges.">The response of quadrangular plates to buried charges.</a> Int. J. Impact Eng. 49, 103-114 (2012).</li><li>Bergeron, D. M., Trembley, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Canadian+research+to+characterize+mine+blast+output.">Canadian research to characterize mine blast output.</a> , (2000).</li><li>Hlady, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+soil+parameters+on+landmine+blast.">Effect of soil parameters on landmine blast.</a> , (2004).</li><li>Fourney, W. L., Leiste, U., Bonenberger, R., Goodings, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanism+of+loading+on+plates+due+to+explosive+detonation.">Mechanism of loading on plates due to explosive detonation.</a> Int. J. on Blasting and Fragmentation. 9 (4), 205-217 (2005).</li><li>Anderson, C. E., Behner, T., Weiss, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mine+blast+loading+experiments.">Mine blast loading experiments.</a> Int. J. Impact Eng. 38 (8-9), 697-706 (2011).</li><li>Fox, D. 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=The+response+of+small+scale+rigid+targets+to+shallow+buried+explosive+detonations.">The response of small scale rigid targets to shallow buried explosive detonations.</a> Int. J. Impact Eng. 38 (11), 882-891 (2011).</li><li>Ehrgott, J. Q., Rhett, R. G., Akers, S. A., Rickman, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design+and+fabrication+of+an+impulse+measurement+device+to+quantify+the+blast+environment+from+a+near-surface+detonation+in+soil.">Design and fabrication of an impulse measurement device to quantify the blast environment from a near-surface detonation in soil.</a> Experimental Techniques. 35 (3), 51-62 (2011).</li><li>Pope, D. J., Tyas, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+hydrocode+modelling+techniques+to+predict+loading+parameters+from+free+air+hemispherical+explosive+charges.">Use of hydrocode modelling techniques to predict loading parameters from free air hemispherical explosive charges.</a> , (2002).</li><li>Clarke, S. D., 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=Repeatability+of+buried+charge+testing.">Repeatability of buried charge testing.</a> , (2014).</li><li>Clarke, S. D., 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=A+large+scale+experimental+approach+to+the+measurement+of+spatially+and+temporally+localised+loading+from+the+detonation+of+shallow-buried+explosives.">A large scale experimental approach to the measurement of spatially and temporally localised loading from the detonation of shallow-buried explosives.</a> Meas Sci Technol. 26, 015001 (2015).</li><li>Hopkinson, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Method+of+Measuring+the+Pressure+Produced+in+the+Detonation+of+High+Explosives+or+by+the+Impact+of+Bullets.">A Method of Measuring the Pressure Produced in the Detonation of High Explosives or by the Impact of Bullets.</a> Philos. Trans. R. Soc. (London) A. 213, 437-456 (1914).</li><li>Rigby, S. E., Tyas, A., Fay, S. D., Clarke, S. D., Warren, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Validation+of+semi-empirical+blast+pressure+predictions+for+far+field+explosions+-+is+there+inherent+variability+in+blast+wave+parameters?.">Validation of semi-empirical blast pressure predictions for far field explosions - is there inherent variability in blast wave parameters?.</a> , (2014).</li><li>Rigby, S. E., Tyas, A., Bennett, T., Clarke, S. D., Fay, S. 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+negative+phase+of+the+blast+load.">The negative phase of the blast load.</a> Int. J. of Protective Structures. 5 (1), 1-20 (2014).</li><li>Rigby, S. E., Fay, S. D., Tyas, A., Warren, J. A., Clarke, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Angle+of+incidence+effects+on+far-field+positive+and+negative+phase+blast+parameters.">Angle of incidence effects on far-field positive and negative phase blast parameters.</a> Int. J. of Protective Structures. 6 (1), 23-42 (2015).</li><li>Tyas, A., Warren, J., Bennett, T., Fay, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prediction+of+clearing+effects+in+far-field+blast+loading+of+finite+targets.">Prediction of clearing effects in far-field blast loading of finite targets.</a> Shock Waves. 21 (2), 111-119 (2011).</li><li>Tyas, A., Watson, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+study+of+the+effect+of+spatial+variation+of+load+in+the+pressure+bar.">A study of the effect of spatial variation of load in the pressure bar.</a> Meas Sci Technol. 11 (11), 1539-1551 (2000).</li><li>Tyas, A., Watson, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+investigation+of+frequency+domain+dispersion+correction+of+pressure+bar+signals.">An investigation of frequency domain dispersion correction of pressure bar signals.</a> Int. J. Impact Eng. 25 (1), 87-101 (2001).</li><li>NATO Standardisation Agency. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Procedures+for+evaluating+the+protection+level+of+logistic+and+light+armoured+vehicles.">Procedures for evaluating the protection level of logistic and light armoured vehicles.</a> Allied Engineering Publication (AEP) 55. 2, (2011).</li><li>Elgy, I. D., 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=.">.</a> UK ministry of defence technical authority instructions for testing the protection level of vehicles against buried blast mines. , (2014).</li><li>Clarke, S. D., 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=Finite+element+simulation+of+plates+under+non-uniform+blast+loads+using+a+point-load+method:+Buried+explosives.">Finite element simulation of plates under non-uniform blast loads using a point-load method: Buried explosives.</a> , (2015).</li><li>Rigby, S. E., 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=Finite+element+simulation+of+plates+under+non-uniform+blast+loads+using+a+point-load+method:+Blast+wave+clearing.">Finite element simulation of plates under non-uniform blast loads using a point-load method: Blast wave clearing.</a> , (2015).</li><li>Hallquist, J. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> LS-DYNA theory manual. , (2006).</li><li>Fay, S. D., 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=Capturing+the+spatial+and+temporal+variations+in+impulse+from+shallow+buried+charges.">Capturing the spatial and temporal variations in impulse from shallow buried charges.</a> , (2013).</li><li>Fay, S. D., 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=Measuring+the+spatial+and+temporal+pressure+variation+from+buried+charges.">Measuring the spatial and temporal pressure variation from buried charges.</a> , (2014).</li></ol>

The authors have nothing to disclose.

著者らは上記で概説プロトコルを使用することは、ホプキンソン圧力棒のアレイを使用して、炸薬の高度変化する負荷の高忠実度の測定値を取得することが可能であることを示しています。補間ルーチンを使用すると、離散圧力 - 時間履歴を数値モデルで、またはこのようなモデルの出力のための検証データとしてローディング機能として直接使用可能である連続衝撃波面に変換することが?...

爆薬の出力を特徴付けることは、両方の（現在の紛争地域で爆発装置を即興埋め込み防御）軍と民間（構造部品を設計する）、多くの利点があります。最近では、このトピックでは、かなりの注目を集めています。集められた知識の多く​​は、より効果的な保護構造物の設計を可能にするための電荷からの出力の定量化を目的としています。ここでの主な問題は、行われた測定は、高忠実度でない場合、これらの爆発的事象における荷重伝達のメカニズムは不明なままであることです。これにより、検証のためにこれらの測定値に依存して数値モデルの検証の問題につながります。 近接場用語はスケールされた距離に芽を記述するために使用され、Zは 、以下~1 mは/ Z = R / W 1/3 1/3、kgでより、Rは、爆薬の中心からの距離であり、W料金は大量に発現されますTNTの等価質量として。このレジームでは負荷は、典型的には、非常に空間的及び時間的に不均一な負荷、非常に高い大きさによって特徴付けられます。堅牢な計装は、したがって、ニアフィールド・ロードに関連した極端な圧力を測定するために必要とされます。 Zは &lt;0.4メートルは/ 1/3 kgのスケーリングされた距離で、爆風パラメーターの直接測定は、存在しないか、1に非常に少数のいずれかであり、この範囲のための半経験的予測データは、パラメトリック研究にほぼ完全に基づいています。これは、著者の意図された範囲の外にあるキンガリーとBulmash 2、によって与えられた半経験的予測を使用することを含みます。これらの予測3,4に基づいて、ツールがロードの優れた一次推定を可能にする一方で、彼らは完全に現在の研究の焦点である近接場イベントの力学をキャプチャしません。 近接場ブラスト測定は、最近では、OUTPを定量化に焦点を当てています埋葬料からユタ。採用の方法論は、グローバルインパルス測定8-13を指示する構造的なターゲット5-7に生じる変形を評価するごとに異なります。これらのメソッドは、保護システム設計の検証のための貴重な情報を提供するが、完全に荷重伝達のメカニズムを調査することができません。試験は、によって生成されるように埋没深さを制御したり、衝撃波面のは固有の形状を確保していないとして、実用的な理由で、または近くにフルスケール（&gt; 1/4）への両方の実験室スケール（1/10フルスケール）で行うことができます起爆装置ではなく、裸の ​​電荷14を使用します。埋め込 ​​み電荷を有する土壌条件は、高度テスト15の再現性を保証するために制御する必要があります。 料金は無料空気中に置かれているか、埋め込まれているかどうかに関係なく、結果として爆発を測定する際の最も基本的な問題は、計装deploによって行われた測定の妥当性を確保することですYED。設計された試験装置16に固定された「剛性」ターゲットプレートは、バーの端部のみを完全に反映圧力を記録することができることを確保すると同時に、一方ホプキンソン圧力棒17（HPBS）を保護するために使用されます。著者らは、以前に18から20を剛性の目標からの反射圧の測定が入射よりも正確かつ反復可能であることを示す、または&#39;自由&#39;フィールド測定しています。このプレートの形状は、対象エッジ21の周囲にクリアまたは流れによって生成された圧力リリーフは無視できるであろうようなものです。この新たな試験装置は1/4スケールで構築されています。このスケールでは埋葬条件や爆発物を厳格にコントロールが25ミリメートルの埋没深さで、78グラムに縮小さ5キロのフルスケール充電サイズで、確保することができます。

<table><tbody><tr><td>Load Cell</td><td>RDP</td><td>RSL0960</td><td>This is only indicative, the exact load cell should be able to resolve the required loading</td></tr><tr><td>Steel target plate / HPBs</td><td>Garratts&amp;nbsp;</td><td></td><td>Fabricated to order</td></tr><tr><td>Strain gauge</td><td>Kyowa</td><td>KSP-2-120-E4</td><td>To use with steel HPBs</td></tr><tr><td>Cyanoacrylate</td><td>Kyowa</td><td>CC-33-A</td><td>Check with manufacturer depending on mar material to be used</td></tr><tr><td>Digital Oscilloscope</td><td>TiePie</td><td>HS4 16-bit Handyscopes&amp;nbsp;</td><td>6 used in parallel in current testing</td></tr><tr><td>Leighton Buzzard sand</td><td>Garside sands</td><td>Garside 14/25</td><td>Uniform silica sand&amp;nbsp;</td></tr></tbody></table>

blast quantification using hopkinson pressure bars

近接場ブラスト負荷測定、彼らは非常に過酷な環境に耐え、メガパスカルの数百までの圧力を測定することができなければならないとして、多くのセンサタイプに問題を提示します。この点でホプキンソン圧力バーの単純さはホプキンソンバーの測定端が耐えることができ、過酷な条件にさらされるが、バーに取り付けられたひずみゲージは、ある距離離れて固定することができるという点で大きな利点を有しています。これは、ひずみゲージを保護するが、測定データの集録と干渉しない保護筐体を利用することができます。圧力バーの配列の使用は、離散的な既知の点における圧力 - 時間履歴を測定することができます。また、この資料では、関心のある平面上の未計測の場所で圧力 - 時間履歴を導出するために使用される補間ルーチンについて説明します。現在の技術は、自由空気中の高性能爆薬から荷重を測定するために使用されており、様々な土壌に浅く埋め。

有効剛性反応フレームを提供する必要があります。現在のテストでは数百ニュートン秒の合計付与インパルスは、最小限の偏向に抵抗する必要があります。使用される硬質反応フレームの図示は、図1に示されている。各フレームが50ミリ鋼「アクセプター」プレートは、クロスビームのベースに鋳造されています。明示的に要求されない一方で、これは?...

Watch this Scientific Journal Video about Blast Quantification Using Hopkinson Pressure Bars at JoVE.com

Blast Quantification Using Hopkinson Pressure Bars

This protocol details the use of Hopkinson pressure bars to measure reflected blast loading from near-field explosive events. It is capable of interpolating a pressure-time history at any point on a reflective boundary and as such can be used to fully characterize the spatial and temporal variations in loading produced.

ブラスト定量ホプキンソン圧力棒を使用して

Near-field blast load measurement presents an issue to many sensor types as they must endure very aggressive environments and be able to measure pressures ...

blast-quantification-using-hopkinson-pressure-bars

Universidad San Sebastian

Research

Education

JoVE Core

JoVE Journal

Civil Engineering

Engineering

Unit 1

Strength of Concrete

SCIENTISTS IN ACTION

8.9K ビュー.  University of Sheffield. This protocol details the use of Hopkinson pressure bars to measure reflected blast loading from near-field explosive events. It is capable of interpolating a pressure-time history at any point on a reflective boundary and as such can be used to fully characterize the spatial and temporal variations in loading produced.

ビデオ: Blast Quantification Using Hopkinson Pressure Bars

Impulsive Pressurization of Neuronal Cells for Traumatic Brain Injury Study

A novel impulsive cell pressurization experiment has been developed using a Kolsky bar device to investigate blast-induced traumatic brain injury (TBI). We demonstrate in this video article how blast TBI-relevant impulsive pressurization is applied to the neuronal cells in vitro. This is achieved by using well-controlled pressure pulse created by a specialized Kolsky bar device, with complete pressure history within the cell pressurization chamber recorded. Pressurized neuronal cells are inspected immediately after pressurization, or further incubated to examine the long-term effects of impulsive pressurization on neurite/axonal outgrowth, neuronal gene expression, apoptosis, etc. We observed that impulsive pressurization at about 2 MPa induces distinct neurite loss relative to unpressurized cells. Our technique provides a novel method to investigate the molecular/cellular mechanisms of blast TBI, via impulsive pressurization of brain cells at well-controlled pressure magnitude and duration.

A novel impulsive cell pressurization experiment has been developed using a Kolsky bar device to investigate the molecular/cellular mechanisms of blast-induced traumatic brain injury.

外傷性脳損傷の研究のための神経細胞のインパルス加

A novel impulsive cell pressurization experiment has been developed using a Kolsky bar device to investigate blast-induced traumatic brain injury (TBI). ...

生物工学

Research and Development of High-performance Explosives

Developmental testing of high explosives for military applications involves small-scale formulation, safety testing, and finally detonation performance tests to verify theoretical calculations. For newly developed formulations, the process begins with small-scale mixes, thermal testing, and impact and friction sensitivity. Only then do subsequent larger scale formulations proceed to detonation testing, which will be covered in this paper. Recent advances in characterization techniques have led to unparalleled precision in the characterization of early-time evolution of detonations. The new technique of Photonic Doppler Velocimetry (PDV) for the measurement of detonation pressure will be shared and compared with traditional fiber-optic detonation velocity and plate-dent calculation of detonation pressure. In particular, the role of aluminum in explosive formulations will be discussed. Recent developments led to the development of explosive formulations that result in reaction of aluminum very early in the detonation product expansion. This enhanced reaction leads to changes in the detonation velocity and pressure due to reaction of the aluminum with oxygen in the expanding gas products.

Developmental testing of high explosives for military applications involves small-scale formulation, safety testing, and finally detonation performance tests to verify theoretical calculations. This paper will share typical development tests associated with the measurement of detonation velocity and detonation pressure.

高性能爆薬の研究開発

Developmental testing of high explosives for military applications involves small-scale formulation, safety testing, and finally detonation performance ...

工学

Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis

Nuclear reaction analysis (NRA) via the resonant 1H(15N,&#945;&#947;)12C reaction is a highly effective method of depth profiling that quantitatively and non-destructively reveals the hydrogen density distribution at surfaces, at interfaces, and in the volume of solid materials with high depth resolution. The technique applies a 15N ion beam of 6.385 MeV provided by an electrostatic accelerator and specifically detects the 1H isotope in depths up to about 2 &#956;m from the target surface. Surface H coverages are measured with a sensitivity in the order of ~1013 cm-2 (~1% of a typical atomic monolayer density) and H volume concentrations with a detection limit of ~1018 cm-3 (~100 at. ppm). The near-surface depth resolution is 2-5 nm for surface-normal 15N ion incidence onto the target and can be enhanced to values below 1 nm for very flat targets by adopting a surface-grazing incidence geometry. The method is versatile and readily applied to any high vacuum compatible homogeneous material with a smooth surface (no pores). Electrically conductive targets usually tolerate the ion beam irradiation with negligible degradation. Hydrogen quantitation and correct depth analysis require knowledge of the elementary composition (besides hydrogen) and mass density of the target material. Especially in combination with ultra-high vacuum methods for in-situ target preparation and characterization, 1H(15N,&#945;&#947;)12C NRA is ideally suited for hydrogen analysis at atomically controlled surfaces and nanostructured interfaces. We exemplarily demonstrate here the application of 15N NRA at the MALT Tandem accelerator facility of the University of Tokyo to (1) quantitatively measure the surface coverage and the bulk concentration of hydrogen in the near-surface region of a H2 exposed Pd(110) single crystal, and (2) to determine the depth location and layer density of hydrogen near the interfaces of thin SiO2 films on Si(100).

We illustrate the application of 1H(15N,&#945;&#947;)12C resonant nuclear reaction analysis (NRA) to quantitatively evaluate the density of hydrogen atoms on the surface, in the volume, and at an interfacial layer of solid materials. The near-surface hydrogen depth profiling of a Pd(110) single crystal and of SiO2/Si(100) stacks is described.

核反応分析と深さ方向分析を通じて表面・界面層とバルク材料中の水素濃度の定量

Nuclear reaction analysis (NRA) via the resonant 1H(15N,&#945;&#947;)12C reaction is a highly effective method of depth profiling that quantitatively and ...

A Uniaxial Compression Experiment with CO2-Bearing Coal Using a Visualized and Constant-Volume Gas-Solid Coupling Test System

Injecting carbon dioxide (CO2) into a deep coal seam is of great significance for reducing the concentration of greenhouse gases in the atmosphere and increasing the recovery of coalbed methane. A visualized and constant-volume gas-solid coupling system is introduced here to investigate the influence of CO2 sorption on the physical and mechanical properties of coal. Being able to keep a constant volume and monitor the sample using a camera, this system offers the potential to improve instrument accuracy and analyze fracture evolution with a fractal geometry method. This paper provides all steps to perform a uniaxial compression experiment with a briquette sample in different CO2 pressures with the gas-solid coupling test system. A briquette, cold-pressed by raw coal and sodium humate cement, is loaded in high-pressure CO2, and its surface is monitored in real-time using a camera. However, the similarity between the briquette and the raw coal still needs improvement, and a flammable gas such as methane (CH4) cannot be injected for the test. The results show that CO2 sorption leads to peak strength and elastic modulus reduction of the briquette, and the fracture evolution of the briquette in a failure state indicates fractal characteristics. The strength, elastic modulus, and fractal dimension are all correlated with CO2 pressure but not with a linear correlation. The visualized and constant-volume gas-solid coupling test system can serve as a platform for experimental research about rock mechanics considering the multifield coupling effect.

A Uniaxial Compression Experiment with CO2-Bearing Coal Using a Visualized and Constant-Volume Gas-Solid Coupling Test System

This protocol demonstrates how to prepare a briquette sample and conduct a uniaxial compression experiment with a briquette in different CO2 pressures using a visualized and constant-volume gas-solid coupling test system. It also aims to investigate changes in terms of coal&#8217;s physical and mechanical properties induced by CO2 adsorption.

可視化・定量ガス固体結合試験システムを用いたCO2-ベアリング石炭を用いた単軸圧縮実験

Injecting carbon dioxide (CO2) into a deep coal seam is of great significance for reducing the concentration of greenhouse gases in the atmosphere and ...

環境学

A Coupled Experiment-finite Element Modeling Methodology for Assessing High Strain Rate Mechanical Response of Soft Biomaterials

This study offers a combined experimental and finite element (FE) simulation approach for examining the mechanical behavior of soft biomaterials (e.g. brain, liver, tendon, fat, etc.) when exposed to high strain rates. This study utilized a Split-Hopkinson Pressure Bar (SHPB) to generate strain rates of 100-1,500 sec-1. The SHPB employed a striker bar consisting of a viscoelastic material (polycarbonate). A sample of the biomaterial was obtained shortly postmortem and prepared for SHPB testing. The specimen was interposed between the incident and transmitted bars, and the pneumatic components of the SHPB were activated to drive the striker bar toward the incident bar. The resulting impact generated a compressive stress wave (i.e. incident wave) that traveled through the incident bar. When the compressive stress wave reached the end of the incident bar, a portion continued forward through the sample and transmitted bar (i.e. transmitted wave) while another portion reversed through the incident bar as a tensile wave (i.e. reflected wave). These waves were measured using strain gages mounted on the incident and transmitted bars. The true stress-strain behavior of the sample was determined from equations based on wave propagation and dynamic force equilibrium. The experimental stress-strain response was three dimensional in nature because the specimen bulged. As such, the hydrostatic stress (first invariant) was used to generate the stress-strain response. In order to extract the uniaxial (one-dimensional) mechanical response of the tissue, an iterative coupled optimization was performed using experimental results and Finite Element Analysis (FEA), which contained an Internal State Variable (ISV) material model used for the tissue. The ISV material model used in the FE simulations of the experimental setup was iteratively calibrated (i.e. optimized) to the experimental data such that the experiment and FEA strain gage values and first invariant of stresses were in good agreement.

The current study prescribes a coupled experiment-finite element simulation methodology to obtain the uniaxial dynamic mechanical response of soft biomaterials (brain, liver, tendon, fat, etc.). The multiaxial experimental results that arose because of specimen bulging obtained from Split-Hopkinson Pressure Bar testing were rendered to a uniaxial true stress-strain behavior when simulated through iterative optimization of the finite element analysis of the biomaterial.

ソフトバイオマテリアルの高ひずみ速度機械的応答を評価するための結合実験、有限要素モデリング手法

This study offers a combined experimental and finite element (FE) simulation approach for examining the mechanical behavior of soft biomaterials (e.g. ...

Conducting Elevated Temperature Normal and Combined Pressure-Shear Plate Impact Experiments Via a Breech-end Sabot Heater System

A novel approach for conducting normal and/or combined pressure-shear plate impact experiments at test temperatures up to 1000 &#176;C is presented. The method enables elevated temperature plate-impact experiments aimed towards probing dynamic behavior of materials under thermomechanical extremes, while mitigating several special experimental challenges faced while performing similar experiments using the conventional plate impact approach. Custom adaptations are made to the breech-end of a single-stage gas-gun at Case Western Reserve University; these adaptations include a precision-machined extension piece made from SAE 4340 steel, which is strategically designed to mate the existing gun-barrel while providing a high tolerance match to the bore and keyway. The extension piece contains a vertical cylindrical heater-well, which houses a heater assembly. A resistive coil heater-head, capable of reaching temperatures of up 1200 &#176;C, is attached to a vertical stem with axial/rotational degrees of freedoms; this enables thin metal specimens held at the front-end of a heat-resistant sabot to be heated uniformly across the diameter to the desired test temperatures. By heating the flyer plate (in this case, the sample) at the breech-end of the gun-barrel instead of at the target-end, several critical experimental challenges can be averted. These include: 1) severe changes in the alignment of the target plate during heating due to the thermal expansion of the several constituents of the target holder assembly; 2) challenges that arise due to the diagnostics elements, (i.e., polymer holographic gratings, and optical probes) being too close to the heated target assembly; 3) challenges that arise for target plates with an optical window, where crucial tolerances between the sample, bond layer, and window become increasingly difficult to maintain at high temperatures; 4) in the case of combined compression-shear plate impact experiments, the need for high-temperature resistant diffraction gratings for the measurement of transverse particle velocity at the free surface of the target; and 5) limitations imposed on the impact velocity necessary for unambiguous interpretation of the measured free surface velocity versus time profile due to thermal softening and possibly yielding of the bounding target plates.By utilizing the adaptations mentioned above, we present results from a series of reverse geometry normal plate impact experiments on commercial purity aluminum at a range of sample temperatures. These experiments show decreasing particle velocities in the impacted state, which are indicative of material softening (decrease in post-yield flow stress) with increasing sample temperatures.

Here, we present a detailed protocol of a new approach for conducting elevated temperature reverse normal plate impact, and combined pressure-and-shear plate impact. The approach involves the use of a breech-end resistive coil heater to heat a sample held at the front-end of a heat-resistant sabot to the desired temperature.

通常の温度の上昇を実施し、尾端サボ ヒーター システムを介して圧力剪断平板衝突試験を組み合わせる

A novel approach for conducting normal and/or combined pressure-shear plate impact experiments at test temperatures up to 1000 &#176;C is presented. The ...

Use of Atomic Force Microscopy to Measure Mechanical Properties and Turgor Pressure of Plant Cells and Plant Tissues

We present here the use of atomic force microscopy to indent plant tissues and recover its mechanical properties. Using two different microscopes in indentation mode, we show how to measure an elastic modulus and use it to evaluate cell wall mechanical properties. In addition, we also explain how to evaluate turgor pressure. The main advantages of atomic force microscopy are that it is non-invasive, relatively rapid (5~20 min), and that virtually any type of living plant tissue that is superficially flat can be analyzed without the need for treatment. The resolution can be very good, depending on the tip size and on the number of measurements per unit area. One limitation of this method is that it only gives direct access to the superficial cell layer.

Here, we present atomic force microscopy (AFM), operated as a nano- and micro-indentation tool on cells and tissues. The instrument allows the simultaneous acquisition of 3D surface topography of the sample and its mechanical properties, including cell wall Young's modulus as well as turgor pressure.

原子間力顕微鏡を用いて植物細胞と植物組織の機械的特性とターゴール圧を測定

We present here the use of atomic force microscopy to indent plant tissues and recover its mechanical properties. Using two different microscopes in ...

発生生物学

A Novel In Vitro Model of Blast Traumatic Brain Injury

Traumatic brain injury is a leading cause of death and disability in military and civilian populations. Blast traumatic brain injury results from the detonation of explosive devices, however, the mechanisms that underlie the brain damage resulting from blast overpressure exposure are not entirely understood and are believed to be unique to this type of brain injury. Preclinical models are crucial tools that contribute to better understand blast-induced brain injury. A novel in vitro blast TBI model was developed using an open-ended shock tube to simulate real-life open-field blast waves modelled by the Friedlander waveform. C57BL/6N mouse organotypic hippocampal slice cultures were exposed to single shock waves and the development of injury was characterized up to 72 h using propidium iodide, a well-established fluorescent marker of cell damage that only penetrates cells with compromised cellular membranes. Propidium iodide fluorescence was significantly higher in the slices exposed to a blast wave when compared with sham slices throughout the duration of the protocol. The brain tissue injury is very reproducible and proportional to the peak overpressure of the shock wave applied.

A Novel In Vitro Model of Blast Traumatic Brain Injury

This paper describes a novel model of primary blast traumatic brain injury. A compressed-air driven shock tube is used to expose in vitro mouse hippocampal slice cultures to a single shock wave. This is a simple and rapid protocol generating a reproducible brain tissue injury with a high throughput.

爆発外傷性脳損傷の新規In Vitroモデル

Traumatic brain injury is a leading cause of death and disability in military and civilian populations. Blast traumatic brain injury results from the ...

神経科学

Low-intensity Blast Wave Model for Preclinical Assessment of Closed-head Mild Traumatic Brain Injury in Rodents

Traumatic brain injury (TBI) is a large-scale public health problem. Mild TBI is the most prevalent form of neurotrauma and accounts for a large number of medical visits in the United States. There are currently no FDA-approved treatments available for TBI. The increased incidence of military-related, blast-induced TBI further accentuates the urgent need for effective TBI treatments. Therefore, new preclinical TBI animal models that recapitulate aspects of human blast-related TBI will greatly advance the research efforts into the neurobiological and pathophysiological processes underlying mild to moderate TBI as well as the development of novel therapeutic strategies for TBI.
Here we present a reliable, reproducible model for the investigation of the molecular, cellular, and behavioral effects of mild to moderate blast-induced TBI. We describe a step-by-step protocol for closed-head, blast-induced mild TBI in rodents using a bench-top setup consisting of a gas-driven shock tube equipped with piezoelectric pressure sensors to ensure consistent test conditions. The benefits of the setup that we have established are its relative low-cost, ease of installation, ease of use and high-throughput capacity. Further advantages of this non-invasive TBI model include the scalability of the blast peak overpressure and the generation of controlled reproducible outcomes. The reproducibility and relevance of this TBI model has been evaluated in a number of downstream applications, including neurobiological, neuropathological, neurophysiological and behavioral analyses, supporting the use of this model for the characterization of processes underlying the etiology of mild to moderate TBI.

We present here a protocol of a blast wave model for rodents to investigate neurobiological and pathophysiological effects of mild to moderate traumatic brain injury. We established a gas-driven, bench-top setup equipped with pressure sensors allowing for reliable and reproducible generation of blast-induced mild to moderate traumatic brain injury.

げっ歯類における閉鎖性軽度外傷性脳損傷の前臨床評価のための低強度ブラスト波モデル

Traumatic brain injury (TBI) is a large-scale public health problem. Mild TBI is the most prevalent form of neurotrauma and accounts for a large number of ...

マウスにおける高反復低レベル爆風をモデル化するためのショックチューブ法

Modeling Highly Repetitive Low-level Blast Exposure in Mice

Exposure to explosive blasts is a significant risk factor for brain trauma among exposed persons. Although the effects of large blasts on the brain are well understood, the effects of smaller blasts such as those that occur during military training are less understood. This small, low-level blast exposure also varies highly according to military occupation and training tempo, with some units experiencing few exposures over the course of several years whereas others experience hundreds within a few weeks. Animal models are an important tool in identifying both the injury mechanisms and long-term clinical health risks following low-level blast exposure. Models capable of recapitulating this wide range of exposures are necessary to inform acute and chronic injury outcomes across these disparate risk profiles.
Although outcomes following a few low-level blast exposures are easily modeled for mechanistic study, chronic exposures that occur over a career may be better modeled by blast injury paradigms with repeated exposures that occur frequently over weeks and months. Shown here are methods for modeling highly repetitive low-level blast exposure in mice. The procedures are based on established and widely used pneumatic shocktube models of open-field blast exposure that can be scaled to adjust the overpressure parameters and the number or interval of the exposures. These methods can then be used to either enable mechanistic investigations or recapitulate the routine blast exposures of clinical groups under study.

著者スポットライト:マウスにおける低レベル爆風曝露の長期的影響の解読

Presented here are methods for producing repeated low-intensity blast exposures using mice.

マウスにおける高反復低レベル爆風曝露のモデリング

Exposure to explosive blasts is a significant risk factor for brain trauma among exposed persons. Although the effects of large blasts on the brain are ...

ブラスト定量ホプキンソン圧力棒を使用して

要約

さらに動画を探す

この動画の章

外傷性脳損傷の研究のための神経細胞のインパルス加

高性能爆薬の研究開発

核反応分析と深さ方向分析を通じて表面・界面層とバルク材料中の水素濃度の定量

可視化・定量ガス固体結合試験システムを用いたCO2-ベアリング石炭を用いた単軸圧縮実験

ソフトバイオマテリアルの高ひずみ速度機械的応答を評価するための結合実験、有限要素モデリング手法

通常の温度の上昇を実施し、尾端サボヒーターシステムを介して圧力剪断平板衝突試験を組み合わせる

原子間力顕微鏡を用いて植物細胞と植物組織の機械的特性とターゴール圧を測定

爆発外傷性脳損傷の新規In Vitroモデル

げっ歯類における閉鎖性軽度外傷性脳損傷の前臨床評価のための低強度ブラスト波モデル

マウスにおける高反復低レベル爆風曝露のモデリング

ブラスト定量ホプキンソン圧力棒を使用して

要約

さらに動画を探す

この動画の章

外傷性脳損傷の研究のための神経細胞のインパルス加

高性能爆薬の研究開発

核反応分析と深さ方向分析を通じて表面・界面層とバルク材料中の水素濃度の定量

可視化・定量ガス固体結合試験システムを用いたCO2-ベアリング石炭を用いた単軸圧縮実験

ソフトバイオマテリアルの高ひずみ速度機械的応答を評価するための結合実験、有限要素モデリング手法

通常の温度の上昇を実施し、尾端サボ ヒーター システムを介して圧力剪断平板衝突試験を組み合わせる

原子間力顕微鏡を用いて植物細胞と植物組織の機械的特性とターゴール圧を測定

爆発外傷性脳損傷の新規In Vitroモデル

げっ歯類における閉鎖性軽度外傷性脳損傷の前臨床評価のための低強度ブラスト波モデル

マウスにおける高反復低レベル爆風曝露のモデリング

通常の温度の上昇を実施し、尾端サボヒーターシステムを介して圧力剪断平板衝突試験を組み合わせる