この作品は、海軍研究局 (ONR N00014-15-1-0020) [Tkacik ・ Keanini] でサポートされているし、メディアは、Rosler によって寄付されたシャーロットのモーター スポーツ研究所研磨でノースカロライナ大学でを行うだった。

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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generalized+hydrodynamics.">Generalized hydrodynamics.</a> Adv. Mol. Relax. Processes. 9, 225-291 (1977).</li><li>Zwanzig, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time-correlation+functions+and+transport+coefficients+in+statistical+mechanics.">Time-correlation functions and transport coefficients in statistical mechanics.</a> Ann. Rev. Phys. Chem. 16, 67-102 (1965).</li><li>Keanini, R. G., 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=Macroscopic+liquid-state+molecular+hydrodynamics.">Macroscopic liquid-state molecular hydrodynamics.</a> Sci. Rep. 7, 41658 (2017).</li><li>Kushick, J., Berne, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+attractive+forces+in+self-diffusion+in+dense+Lennard-Jones+fluids.">Role of attractive forces in self-diffusion in dense Lennard-Jones fluids.</a> J. Chem. Phys. 59 (7), 3732-3736 (1973).</li><li>Mullany, B., 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+application+of+computational+fluid+dynamics+to+vibratory+finishing+processes.">The application of computational fluid dynamics to vibratory finishing processes.</a> CIRP Annals. , (2017).</li><li>Fleischhauer, E., Azimi, F., Tkacik, P. T., Keanini, R. 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C., Fernandez-Serra, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+hydrogen-bond+network+of+water+supports+propagating+optical+phonon-like+modes.">The hydrogen-bond network of water supports propagating optical phonon-like modes.</a> Nat. Commun. 7, 10193 (2016).</li><li>Pathria, R. K., Beale, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Statistical mechanics. , (2011).</li><li>Gibbs, J. 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Japan. 12, 570-586 (1957).</li><li>Kubo, R., Toda, M., Hashitsume, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Statistical physics II: nonequilibrium statistical mechanics. , (1991).</li></ol>

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分子流体力学的プロセスを調査するためには、巨視的な類縁体として振動粒杭を使用、するために、想いをしましたする必要があります、一方で学ぶ 4 つの基本的な測定を使用してし、一方で、平衡のいくつかの基本的な要素をマスターし、非平衡統計力学。最初実験測定に着目し、これらが含まれて: i) 単一粒子速度相関関数、ii) 時間の平均/長期スケール表面粒の速度の測定の観測を通じ...

分子流体力学は、ダイナミクスと個々 の分子の統計力学および流体内の分子のコレクションを研究します。多くの実験の中で分子流体システム1,2, 光散乱1,2,3, 分子動力学シミュレーション4、勉強のために開発 5,6,7より少ない程度に、中性子非弾性散乱8を最も一般的に使用されています。残念なことに、後者の 2 つの方法に重要な制限を添付します。分子動力学 (MD) シミュレーション、例えば: i) は時空小限定<img alt="Equation 1" src="/files/ftp_upload/56632/56632eq1.jpg">比較的少数の分子を含むドメイン<img alt="Equation 2" src="/files/ftp_upload/56632/56632eq2.jpg">、ii) を使用する必要おおよその粒子間電位の iii) 通常周期を紹介境界条件、非平衡バルク フロー条件、および iv の下で無効な) 現時点では、どのように分子動力学、分子または分子のコレクションのいずれかを含むの基本的な質問を答えることができない、受けますが、カップルバルクは、非平衡流体の流れに戻る。中性子散乱に関連付けられている主な制限は、利用可能な中性子ビーム源の限られた数にアクセスする難しさに結びついています。
この記事で紹介したアナログの実験技術のコンテキストを提供するためには、単純な高密度ガスと液体状態の流体に適用される光散乱技術を強調表示します。典型的な光散乱実験で偏光レーザー光ビームは静止流体のサンプルを含む小さな尋問ボリュームに送られます。サンプル内の分子からの散乱光が入射ビームに対していくつかの固定角度でそれから検出されます。興味の分子の動的な政権によって散乱光信号の検出と解析を組み込んだ光フィルタ リングまたは光検出方法を混合します。ベルンとペコラの1に従って、フィルタ リング技術、スケールはより短い時間に流体状態分子動力学をプローブする<img alt="Equation 3" src="/files/ftp_upload/56632/56632eq3.jpg">s、後散乱干渉計や回折格子を紹介し、スペクトル密度のスキャンを許可します。散乱光。ミキシングのテクニック、遅い時間スケールのダイナミクス用光<img alt="Equation 4" src="/files/ftp_upload/56632/56632eq4.jpg">s、対照的に、組み込む散乱信号のスペクトルの分布は測定された散乱光から抽出する、散乱後自己相関器またはスペクトラム アナライザー強度。
一般に、レーザー プローブ、少なくともこれらのスペクトルの目に見える範囲内で液体状態の分子の特性の間隔よりも長い波長を持っています。これらの状況下でプローブ ビーム励起 5 集団があり、遅い時間スケール、全長波流体モード2,9,10 (特性の衝突の頻度を基準にして低速): 2 つの粘性対向する音の波、2 つの共役、純粋な拡散渦モード、および単一拡散熱 (エントロピー) モード、減衰します。渦モードが横方向に興奮している間、サウンド モードは入射ビームの (縦) 方向に興奮しています。
純粋に実験的手法、平衡の心そして分子の非平衡統計力学の横になっている 2 つの基本的な質問を散乱を考慮した液体状態のシステムは、光と中性子散乱測定を超えて残る。 1) 厳格な引数9,11ショーの古典的なニュートン力学や量子力学の対象と、個々 の液体状態の分子のランダムな衝突とサブ-衝突-時間スケール動力学を作り直したことができます、一般化ランジュバン方程式 (GLE) の形。GLE の順番に、高密度の気体や液体中の分子の非平衡統計力学の研究では中心的な理論的ツールで構成されます。残念ながら、個々 の (非高分子) 分子のダイナミクスは、どちらの散乱法で解決できない、以来無い現在 GLE の有効性をテストする分子動力学シミュレーションを超えて、直接的な方法。 2) 巨視的連続流体の中心部で横になっている根本的な仮説、同様のマイクロ分子流体力学、それの長さと時間のスケール分子径と連続体を基準にして数回、しかし小さな衝突に比べて大きいを仮説します。長さと時間のスケール、ローカル熱力学の平衡 (LTE) が優先されます。(NS) ナビエ-ストークス方程式のような連続体の流動および熱伝達モデル LTE 想定していますカップルは本質的に非平衡、連続スケールのフローとエネルギー輸送の機能するために必要な9 -粘性せん断応力のように、熱伝導-厳密に平衡熱力学的性質、温度と内部エネルギーのように。同様に、マイクロ スケールの運動量とエネルギーの輸送は本質的に非平衡プロセス、結合、マイクロ スケール固まりの出現を反映してこれらのマイクロ プロセスの勢いとエネルギー流モデルと仮定電流LTE9から小さな摂動を表してください。もう一度、我々 の知識の限りでなかった LTE 前提の直接実験。特に、高密度、移動、非平衡流体内流体分子の散乱実験を試行されているはないようであります。
この稿では、直接予測できない、標準粒子画像流速測定法 (PIV) を用いて振動粒杭のマクロスコ ピックの単一の粒子の集合体学に使用でくアナログ実験的な手法をまとめました解釈、および高密度の気体と液体でシングルとマルチ molecule 流体力学を公開します。私たちのグループ12によって発表された最近の論文で提案手法を可能にする物理・理論的要素のとおりです。実験的に、巨視的な系を表わさなければならない: (i) (弱い) の非平衡揺らぎを模倣するローカル、マクロ統計力学的平衡、および (ii) 小さい平衡から出発線形持続的な傾向が観察分子流体力学的システム。理論: 平衡および高密度の弱非平衡統計力学を記述する (i) 古典的なマイクロ スケール モデル、N 粒子システムの相互作用する必要があります。 改鋳されるマクロの形で、(ii) の結果のマクロ モデルを確実にする必要があります。短い、粒子-衝突-タイム スケール、長い連続-流れ-時間 - スケールからの単一および複数粒子ダイナミクスを予測します。
ここでは、新しい手法により得られた代表的な結果と同様に、詳細な実験的プロトコルを提案します。分子動力学シミュレーションと光と中性子散乱法と対照をなして新しいテクニックができます、最初の時間の流れる、強く非平衡、密なガス、液体内の分子の流体力学的プロセスの詳細な研究。

<table>
	<tbody>
		<tr>
			<td>Vibratory Polishing Bowl</td>
			<td>Raytech</td>
			<td>AV-75</td>
			<td></td>
		</tr>
		<tr>
			<td>Flow Meter</td>
			<td>Peristaltic Pumps</td>
			<td>913 Mity Flex</td>
			<td></td>
		</tr>
		<tr>
			<td>Scale</td>
			<td>Pelouze</td>
			<td>4040</td>
			<td></td>
		</tr>
		<tr>
			<td>Triaxial Accelerometer</td>
			<td>PCB Piezotronics</td>
			<td>PCB 356B11</td>
			<td>Accelerometer with Sensor Signal Conditioner</td>
		</tr>
		<tr>
			<td>Data Acquisition Computer</td>
			<td>IBM</td>
			<td>Thinkpad</td>
			<td>Used with high speed camera</td>
		</tr>
		<tr>
			<td>High Speed Camera</td>
			<td>Redlake</td>
			<td>Motionxtra HG-XR</td>
			<td></td>
		</tr>
		<tr>
			<td>Zoom Lens</td>
			<td>Tamron</td>
			<td>Model A18</td>
			<td>18-250mm F/3.5-6.3&#160;</td>
		</tr>
		<tr>
			<td>High intensity Light</td>
			<td>ARRI</td>
			<td>EB 400/575 D</td>
			<td></td>
		</tr>
		<tr>
			<td>Data Processing Computer</td>
			<td>Dell</td>
			<td>Dell Precision Tower 7910</td>
			<td></td>
		</tr>
		<tr>
			<td>PIV Software&#160;</td>
			<td>Dantec Dynamics</td>
			<td>Dynamic Studio 2013</td>
			<td>version 3.41.38</td>
		</tr>
		<tr>
			<td>Data Acquisition Hardware</td>
			<td>National Instruments</td>
			<td>SCXI</td>
			<td>SCXI-1000 Chasis with SCXI 1100 Card and SCXI 1303 Adapter</td>
		</tr>
		<tr>
			<td>Data Acquisition Software</td>
			<td>National Instruments</td>
			<td>LabVIEW 2012</td>
			<td></td>
		</tr>
		<tr>
			<td>Data Processing Software</td>
			<td>MATHWORKS</td>
			<td>MATLAB</td>
			<td></td>
		</tr>
		<tr>
			<td>Polishing Media</td>
			<td>Rosler</td>
			<td>RSG 10/10S</td>
			<td>Multiple media types used (mixed, spherical, triangular)</td>
		</tr>
		<tr>
			<td>Polishing Solution</td>
			<td>Rosler</td>
			<td>FC KFL (3%)</td>
			<td>3% soap solution with water</td>
		</tr>
		<tr>
			<td>Ruled Scale</td>
			<td>Swiss Precision Instruments</td>
			<td>13-911-3</td>
			<td></td>
		</tr>
		<tr>
			<td>Graduated Cylinder</td>
			<td>Global Scientific</td>
			<td>601082</td>
			<td></td>
		</tr>
	</tbody>
</table>

an analog macroscopic technique for studying molecular hydrodynamic processes in dense gases and liquids

アナログ、巨視的高密度の気体と液体の分子スケール流体プロセスを勉強する方法が説明されています。テクニック適用、標準液動的診断、粒子画像流速測定 (PIV) を測定する: i) 個々 の粒子 (粒)、短い、粒の衝突に関する現存する速度の時間スケール、ii) の両方の短い粒子のシステムの速度衝突-時間と長く、連続フロー時間スケールの iii) 高密度分子流体と iv に存在する知られている集団の流体モード) 短・長期-時間スケール速度相関関数、中央の粒子スケールのダイナミクスを理解するため強く相互作用する、高密度流体システム。基本的なシステムは、イメージング システム、光源、振動センサー、振動システム知られているメディア、および PIV 解析ソフトウェアで構成されます。必要な実験とアナログの技術を使用して分子流体力学的プロセスを研究するときに必要な理論的ツールのアウトラインが強調表示されます。提案手法は、光に比較的簡単な代わるし、中性子ビーム散乱法分子の流体力学的研究で伝統的に使用します。

代表的な結果を提示、我々 を参照してください連続時系列プロセス、それらの観測・予測、時間スケールで<img alt="Equation 25" src="/files/ftp_upload/56632/56632eq25.jpg">長特性粒衝突時間スケールを基準にしている<img alt="Equation 26" src="/files/ftp_upload/56632/56632eq26.jpg"> <img alt="Equation 27" src="/files/ftp_upload/56632/56632eq27.jpg"> 、 粒子時間スケール観察し、時間スケールで予測...

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An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

高密度流体中の分子の流体力学的過程を研究するため実験的にアクセス可能なアナログ方式である. します。テクニックは振動、高反発粒杭の粒子画像流速測定法を使用し、動的プロセス知られているし、強く相互作用する、高密度気体、液体中に存在する予測の肉眼で直接観察を可能します。

高密度の気体と液体の分子流体力学的過程を研究するためのアナログ巨視的手法

An analog, macroscopic method for studying molecular-scale hydrodynamic processes in dense gases and liquids is described. The technique applies a ...

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8.4K ビュー.  University of North Carolina at Charlotte. 高密度流体中の分子の流体力学的過程を研究するため実験的にアクセス可能なアナログ方式である. します。テクニックは振動、高反発粒杭の粒子画像流速測定法を使用し、動的プロセス知られているし、強く相互作用する、高密度気体、液体中に存在する予測の肉眼で直接観察を可能します。

ビデオ: An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy

The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted significant interests across the research fields of materials science, physics, chemistry and biology. The key enabling technology is a liquid cell. We fabricate liquid cells with thin viewing windows through a sequential microfabrication process, including silicon nitride membrane deposition, photolithographic patterning, wafer etching, cell bonding, etc. A liquid cell with the dimensions of a regular TEM grid can fit in any standard TEM sample holder. About 100 nanoliters reaction solution is loaded into the reservoirs and about 30 picoliters liquid is drawn into the viewing windows by capillary force. Subsequently, the cell is sealed and loaded into a microscope for in situ imaging. Inside the TEM, the electron beam goes through the thin liquid layer sandwiched between two silicon nitride membranes. Dynamic processes of nanoparticles in liquids, such as nucleation and growth of nanocrystals, diffusion and assembly of nanoparticles, etc., have been imaged in real time with sub-nanometer resolution. We have also applied this method to other research areas, e.g., imaging proteins in water. Liquid cell TEM is poised to play a major role in revealing dynamic processes of materials in their working environments. It may also bring high impact in the study of biological processes in their native environment.

We have developed a self-contained liquid cell, which allows imaging through liquids using a transmission electron microscope. Dynamic processes of nanoparticles in liquids can be revealed in real time with sub-nanometer resolution.

液晶セルの透過型電子顕微鏡を使用して液体の材料の動的過程を明らかにする

The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted ...

工学

Simulation of the Planetary Interior Differentiation Processes in the Laboratory

A planetary interior is under high-pressure and high-temperature conditions and it has a layered structure. There are two important processes that led to that layered structure, (1) percolation of liquid metal in a solid silicate matrix by planet differentiation, and (2) inner core crystallization by subsequent planet cooling. We conduct high-pressure and high-temperature experiments to simulate both processes in the laboratory. Formation of percolative planetary core depends on the efficiency of melt percolation, which is controlled by the dihedral (wetting) angle. The percolation simulation includes heating the sample at high pressure to a target temperature at which iron-sulfur alloy is molten while the silicate remains solid, and then determining the true dihedral angle to evaluate the style of liquid migration in a crystalline matrix by 3D visualization. The 3D volume rendering is achieved by slicing the recovered sample with a focused ion beam (FIB) and taking SEM image of each slice with a FIB/SEM crossbeam instrument. The second set of experiments is designed to understand the inner core crystallization and element distribution between the liquid outer core and solid inner core by determining the melting temperature and element partitioning at high pressure. The melting experiments are conducted in the multi-anvil apparatus up to 27 GPa and extended to higher pressure in the diamond-anvil cell with laser-heating. We have developed techniques to recover small heated samples by precision FIB milling and obtain high-resolution images of the laser-heated spot that show melting texture at high pressure. By analyzing the chemical compositions of the coexisting liquid and solid phases, we precisely determine the liquidus curve, providing necessary data to understand the inner core crystallization process.

The high-pressure and high-temperature experiments described here mimic planet interior differentiation processes. The processes are visualized and better understood by high-resolution 3D imaging and quantitative chemical analysis.

研究室での惑星インテリア分化過程のシミュレーション

A planetary interior is under high-pressure and high-temperature conditions and it has a layered structure. There are two important processes that led to ...

Spatial Separation of Molecular Conformers and Clusters

Gas-phase molecular physics and physical chemistry experiments commonly use supersonic expansions through pulsed valves for the production of cold molecular beams. However, these beams often contain multiple conformers and clusters, even at low rotational temperatures. We present an experimental methodology that allows the spatial separation of these constituent parts of a molecular beam expansion. Using an electric deflector the beam is separated by its mass-to-dipole moment ratio, analogous to a bender or an electric sector mass spectrometer spatially dispersing charged molecules on the basis of their mass-to-charge ratio. This deflector exploits the Stark effect in an inhomogeneous electric field and allows the separation of individual species of polar neutral molecules and clusters. It furthermore allows the selection of the coldest part of a molecular beam, as low-energy rotational quantum states generally experience the largest deflection. Different structural isomers (conformers) of a species can be separated due to the different arrangement of functional groups, which leads to distinct dipole moments. These are exploited by the electrostatic deflector for the production of a conformationally pure sample from a molecular beam. Similarly, specific cluster stoichiometries can be selected, as the mass and dipole moment of a given cluster depends on the degree of solvation around the parent molecule. This allows experiments on specific cluster sizes and structures, enabling the systematic study of solvation of neutral molecules.

We present a technique that allows the spatial separation of different conformers or clusters present in a molecular beam. An electrostatic deflector is used to separate species by their mass-to-dipole moment ratio, leading to the production of gas-phase ensembles of a single conformer or cluster stoichiometry.

分子適合体とクラスターの空間的分離

Gas-phase molecular physics and physical chemistry experiments commonly use supersonic expansions through pulsed valves for the production of cold ...

The Preparation of Electrohydrodynamic Bridges from Polar Dielectric Liquids

Horizontal and vertical liquid bridges are simple and powerful tools for exploring the interaction of high intensity electric fields (8-20 kV/cm) and polar dielectric liquids. These bridges are unique from capillary bridges in that they exhibit extensibility beyond a few millimeters, have complex bi-directional mass transfer patterns, and emit non-Planck infrared radiation. A number of common solvents can form such bridges as well as low conductivity solutions and colloidal suspensions. The macroscopic behavior is governed by electrohydrodynamics and provides a means of studying fluid flow phenomena without the presence of rigid walls. Prior to the onset of a liquid bridge several important phenomena can be observed including advancing meniscus height (electrowetting), bulk fluid circulation (the Sumoto effect), and the ejection of charged droplets (electrospray). The interaction between surface, polarization, and displacement forces can be directly examined by varying applied voltage and bridge length. The electric field, assisted by gravity, stabilizes the liquid bridge against Rayleigh-Plateau instabilities. Construction of basic apparatus for both vertical and horizontal orientation along with operational examples, including thermographic images, for three liquids (e.g., water, DMSO, and glycerol) is presented.

Horizontal and vertical electrohydrodynamic liquid bridges are simple and powerful tools for exploring the interaction of high intensity electric fields and polar dielectric liquids. The construction of basic apparatus and operational examples, including thermographic images, for three liquids (e.g., water, DMSO, and glycerol) is presented.

ポーラー液体誘電体から電気流体橋の調製

Horizontal and vertical liquid bridges are simple and powerful tools for exploring the interaction of high intensity electric fields (8-20 kV/cm) and ...

Formation of Thick Dense Yttrium Iron Garnet Films Using Aerosol Deposition

Aerosol deposition (AD) is a thick-film deposition process that can produce layers up to several hundred micrometers thick with densities greater than 95% of the bulk. The primary advantage of AD is that the deposition takes place entirely at ambient temperature; thereby enabling film growth in material systems with disparate melting temperatures. This report describes in detail the processing steps for preparing the powder and for performing AD using the custom-built system. Representative characterization results are presented from scanning electron microscopy, profilometry, and ferromagnetic resonance for films grown in this system. As a representative overview of the capabilities of the system, focus is given to a sample produced following the described protocol and system setup. Results indicate that this system can successfully deposit 11 &#181;m thick yttrium iron garnet films that are &#160;&#62; 90% of the bulk density during a single 5 min deposition run. A discussion of methods to afford better control of the aerosol and particle selection for improved thickness and roughness variations in the film is provided.

This report describes the use of a custom-built system to perform aerosol deposition of thick films of yttrium iron garnet onto sapphire substrates at RT. The deposited films are characterized using scanning electron microscopy, profilometry, and ferromagnetic resonance to give a representative overview of the capabilities of the technique.

エアロゾルデポジション法を用いて厚い高密度イットリウム鉄ガーネット膜の形成

Aerosol deposition (AD) is a thick-film deposition process that can produce layers up to several hundred micrometers thick with densities greater than 95% ...

Experimental Methods for Investigation of Shape Memory Based Elastocaloric Cooling Processes and Model Validation

Shape Memory Alloys (SMA) using elastocaloric cooling processes have the potential to be an environmentally friendly alternative to the conventional vapor compression based cooling process. Nickel-Titanium (Ni-Ti) based alloy systems, especially, show large elastocaloric effects. Furthermore, exhibit large latent heats which is a necessary material property for the development of an efficient solid-state based cooling process. A scientific test rig has been designed to investigate these processes and the elastocaloric effects in SMAs. The realized test rig enables independent control of an SMA&#39;s mechanical loading and unloading cycles, as well as conductive heat transfer between SMA cooling elements and a heat source/sink. The test rig is equipped with a comprehensive monitoring system capable of synchronized measurements of mechanical and thermal parameters. In addition to determining the process-dependent mechanical work, the system also enables measurement of thermal caloric aspects of the elastocaloric cooling effect through use of a high-performance infrared camera. This combination is of particular interest, because it allows illustrations of localization and rate effects &#8212; both important for efficient heat transfer from the medium to be cooled.
The work presented describes an experimental method to identify elastocaloric material properties in different materials and sample geometries. Furthermore, the test rig is used to investigate different cooling process variations. The introduced analysis methods enable a differentiated consideration of material, process and related boundary condition influences on the process efficiency. The comparison of the experimental data with the simulation results (of a thermomechanically coupled finite element model) allows for better understanding of the underlying physics of the elastocaloric effect. In addition, the experimental results, as well as the findings based on the simulation results, are used to improve the material properties.

Experimental methods for investigation of solid state cooling processes and characterization of elastocaloric material properties of Shape Memory Alloys (SMA) are presented. A custom-built test rig has been designed for controlling and comprehensive monitoring of elastocaloric cooling processes. Furthermore, it provides a validation platform for thermomechanically coupled modeling approaches.

形状記憶基づきElastocaloric冷却プロセスの調査とモデル検証のための実験方法

Shape Memory Alloys (SMA) using elastocaloric cooling processes have the potential to be an environmentally friendly alternative to the conventional vapor ...

Studying Dynamic Processes of Nano-sized Objects in Liquid using Scanning Transmission Electron Microscopy

Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a microfluidic chamber assembled in the specimen holder for Transmission Electron Microscopy (TEM) and STEM. The microfluidic system consists of two silicon microchips supporting thin Silicon Nitride (SiN) membrane windows. This article describes the basic steps of sample loading and data acquisition. Most important of all is to ensure that the liquid compartment is correctly assembled, thus providing a thin liquid layer and a vacuum seal. This protocol also includes a number of tests necessary to perform during sample loading in order to ensure correct assembly. Once the sample is loaded in the electron microscope, the liquid thickness needs to be measured. Incorrect assembly may result in a too-thick liquid, while a too-thin liquid may indicate the absence of liquid, such as when a bubble is formed. Finally, the protocol explains how images are taken and how dynamic processes can be studied. A sample containing AuNPs is imaged both in pure water and in saline.

This protocol describes the operation of a liquid flow specimen holder for scanning transmission electron microscopy of AuNPs in water, as used for the observation of nanoscale dynamic processes.

走査型透過電子顕微鏡を用いて、液体中にナノサイズのオブジェクトの動的プロセスを学びます

Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a ...

Wicking Tests for Unidirectional Fabrics: Measurements of Capillary Parameters to Evaluate Capillary Pressure in Liquid Composite Molding Processes

During impregnation of a fibrous reinforcement in liquid composite molding (LCM) processes, capillary effects have to be understood in order to identify their influence on void formation in composite parts. Wicking in a fibrous medium described by the Washburn equation was considered equivalent to a flow under the effect of capillary pressure according to the Darcy law. Experimental tests for the characterization of wicking were conducted with both carbon and flax fiber reinforcement. Quasi-unidirectional fabrics were then tested by means of a tensiometer to determine the morphological and wetting parameters along the fiber direction. The procedure was shown to be promising when the morphology of the fabric is unchanged during capillary wicking. In the case of carbon fabrics, the capillary pressure can be calculated. Flax fibers are sensitive to moisture sorption and swell in water. This phenomenon has to be taken into account to assess the wetting parameters. In order to make fibers less sensitive to water sorption, a thermal treatment was carried out on flax reinforcements. This treatment enhances fiber morphological stability and prevents swelling in water. It was shown that treated fabrics have a linear wicking trend similar to those found in carbon fabrics, allowing for the determination of capillary pressure.

An experimental method to measure geometrical parameters and the apparent advancing contact angles describing capillary wicking in unidirectional synthetic and natural fabrics is proposed. These parameters are mandatory for the determination of the capillary pressures that must be taken into account for liquid composite molding (LCM) applications.

単方向生地のためのテストをウィッキング：キャピラリーパラメータの測定を液体複合成形プロセスに毛細管圧力を評価します

During impregnation of a fibrous reinforcement in liquid composite molding (LCM) processes, capillary effects have to be understood in order to identify ...

Preparation of Liquid Crystal Networks for Macroscopic Oscillatory Motion Induced by Light

A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous light irradiation. The photo-excitation of dopants that can quickly dissipate light into heat, coupled with anisotropic thermal expansion and self-shadowing of the film, gives rise to the self-sustained deformation. The oscillations observed are influenced by the dimensions and the modulus of the film, and by the directionality and intensity of the light. The system developed offers applications in energy conversion and harvesting for soft-robotics and automated systems.
The general method described here consists of creating free-standing liquid crystalline films and characterizing the mechanical and thermal effects observed. The molecular alignment is achieved using alignment layers (rubbed polyimide), commonly used in the display manufacturing industry. To obtain actuators with large deformation, the mesogens are aligned and polymerized in a splay/bend configuration, i.e., with the director of the liquid crystals (LCs) going gradually from planar to homeotropic through the film thickness. Upon irradiation, the mechanical and thermal oscillations obtained are monitored with a high-speed camera. The results are further quantified by image analysis using an image processing program.

The goal of the protocol is to create liquid crystalline polymer films that can mechanically oscillate under continuous light irradiation. We describe in great detail the conception of free-standing films, from the liquid crystal alignment method to the photo-actuation. The experimental protocol applied to prepare this material is broadly applicable.

巨視的揺動運動の光によって誘起される液晶ネットワークの準備

A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous ...

An Available Technique for Preparation of New Cast MnCuNiFeZnAl Alloy with Superior Damping Capacity and High Service Temperature

Manganese (Mn)-copper (Cu)-based alloys have been found to have&#160;damping capacity and can be used to reduce harmful vibrations and noise effectively. M2052 (Mn-20Cu-5Ni-2Fe, at%) is an important branch of Mn-Cu-based alloys, which possesses both excellent damping capacity and processability. In recent decades, lots of studies have been carried out on the performance optimization of M2052, improving the damping capacity, mechanical properties, corrosion resistance, and service temperature, etc. The major methods of performance optimization are alloying, heat treatment, pretreatment, and different ways of molding etc., among which alloying, as well as adopting a reasonable heat treatment, is the simplest and most effective method to obtain perfect and comprehensive performance. To obtain the M2052 alloy with excellent performance for casting molding, we propose to add Zn and Al to the MnCuNiFe alloy matrix and use a variety of heat treatment methods for a comparison in the microstructure, damping capacity, and service temperature. Thus, a new type of cast-aged Mn-22.68Cu-1.89Ni-1.99Fe-1.70Zn-6.16Al (at.%) alloy with&#160;superior damping capacity and high service temperature is obtained by an optimized heat treatment method. Compared with the forging technique, cast molding is simpler and more efficient, and the damping capacity of this as-cast alloy is excellent. Therefore, there is a suitable reason to think that it is a good choice for engineering applications.

Here we present a protocol to obtain a novel Mn-Cu-based alloy with excellent comprehensive performances by a high-quality smelting technology and reasonable heat treatment methods.

新しいキャスト MnCuNiFeZnAl 合金の優れた能力と高いサービス温度の減衰の準備のための利用可能な手法

Manganese (Mn)-copper (Cu)-based alloys have been found to have&#160;damping capacity and can be used to reduce harmful vibrations and noise effectively. ...