Note: Molecular diffusivity in a small pore zeolite measured by a variable pressure (piezometric) uptake method

2016 ◽  
Vol 87 (3) ◽  
pp. 036101 ◽  
Author(s):  
Fei Wang ◽  
Yasukazu Kobayashi ◽  
Usman Muhammad ◽  
Dezheng Wang ◽  
Yao Wang
Author(s):  
M. Yamada ◽  
K. Ueda ◽  
K. Kuboki ◽  
H. Matsushima ◽  
S. Joens

Use of variable Pressure SEMs is spreading among electron microscopists The variable Pressure SEM does not necessarily require specimen Preparation such as fixation, dehydration, coating, etc which have been required for conventional scanning electron microscopy. The variable Pressure SEM allows operating Pressure of 1˜270 Pa in specimen chamber It does not allow microscopy of water-containing specimens under a saturated vapor Pressure of water. Therefore, it may cause shrink or deformation of water-containing soft specimens such as plant cells due to evaporation of water. A solution to this Problem is to lower the specimen temperature and maintain saturated vapor Pressures of water at low as shown in Fig. 1 On this technique, there is a Published report of experiment to have sufficient signal to noise ratio for scondary electron imaging at a relatively long working distance using an environmental SEM. We report here a new low temperature microscopy of soft Plant cells using a variable Pressure SEM (Hitachi S-225ON).


2018 ◽  
Vol 4 (5) ◽  
pp. 7
Author(s):  
Shivam Dwivedi ◽  
Prof. Vikas Gupta

As the four-wheel steering (4WS) system has great potentials, many researchers' attention was attracted to this technique and active research was made. As a result, passenger cars equipped with 4WS systems were put on the market a few years ago. This report tries to identify the essential elements of the 4WS technology in terms of vehicle dynamics and control techniques. Based on the findings of this investigation, the report gives a mechanism of electronically controlling the steering system depending on the variable pressure applied on it. This enhances the controlling and smoothens the operation of steering mechanism.


2020 ◽  
Author(s):  
Theodosios Famprikis ◽  
O. Ulas Kudu ◽  
James Dawson ◽  
Pieremanuele Canepa ◽  
François Fauth ◽  
...  

<div> <p>Fast-ion conductors are critical to the development of solid-state batteries. The effects of mechanochemical synthesis that lead to increased ionic conductivity in an archetypical sodium-ion conductor Na<sub>3</sub>PS<sub>4</sub> are not fully understood. We present here a comprehensive analysis based on diffraction (Bragg, pair distribution function), spectroscopy (impedance, Raman, NMR, INS) and <i>ab-initio</i> simulations aimed at elucidating the synthesis-property relationships in Na<sub>3</sub>PS<sub>4</sub>. We consolidate previously reported interpretations about the local structure of ball-milled samples, underlining the sodium disorder and showing that a local tetragonal framework more accurately describes the structure than the originally proposed cubic one. Through variable-pressure impedance spectroscopy measurements, we report for the first time the activation volume for Na<sup>+</sup> migration in Na<sub>3</sub>PS<sub>4</sub>, which is ~30% higher for the ball-milled samples. Moreover, we show that the effect of ball-milling on increasing the ionic conductivity of Na<sub>3</sub>PS<sub>4</sub> to ~10<sup>-4</sup> S/cm can be reproduced by applying external pressure on a sample from conventional high temperature ceramic synthesis. We conclude that the key effects of mechanochemical synthesis on the properties of solid electrolytes can be analyzed and understood in terms of pressure, strain and activation volume.</p> </div>


1980 ◽  
Vol 45 (4) ◽  
pp. 1010-1035 ◽  
Author(s):  
Ondřej Wein ◽  
Václav Sobolík

A model is studied in the full range of all operational parameters of the unsteady plane flow of a power-law liquid induced by periodically variable pressure drop and oscillatory motion of the walls of a plane duct. Using the theory of similariry criteria of the asymptotic behaviour are formulated in four qualitatively different rheodynamic regimes. Corresponding asymptotic expressions are found for the degree of mechanical liquidization by the action of oscillatory shear stress superimposed on the principal steady state component. Theoretical results are illustrated using a set of experimental data on the gravitational flow along a vertical oscillating sheet.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Takehiko Manabe ◽  
Kenji Ono ◽  
Soichi Oka ◽  
Yuichiro Kawamura ◽  
Toshihiro Osaki

Abstract Background Pleuroperitoneal communication (PPC) is rarely observed, accounting for 1.6% of all patients who undergo continuous ambulatory peritoneal dialysis (CAPD). Although there have been several reports concerning the management of this condition, we have encountered several cases in which control failed. We herein report a valuable case of PPC in which laparoscopic pneumoperitoneum with video-assisted thoracic surgery (VATS) was useful for supporting the diagnosis and treatment. Case presentation The patient was a 58-year-old woman with chronic renal failure due to chronic renal inflammation who was referred to a nephrologist in our hospital to undergo an operation for the induction of CAPD. Post-operatively, she had respiratory failure, and chest X-ray and computed tomography (CT) showed right-sided hydrothorax that decreased when the injection of peritoneal dialysate was interrupted. Therefore, PPC was suspected, and she was referred to our department for surgical repair. We planned surgical treatment via video-assisted thoracic surgery. During the surgery, we failed to detect any lesions with thoracoscopy alone; we therefore added a laparoscopic port at her right-sided abdomen near the navel and infused CO2 gas into the abdominal cavity. On thoracoscopy, bubbles were observed emanating from a small pore at the central tendon of the diaphragm, which was considered to be the lesion responsible for the PPC. We closed it by suturing directly. Conclusions VATS with laparoscopic pneumoperitoneum should be considered as an effective method for inspecting tiny pores of the diaphragm, especially when the lesions responsible for PPC are difficult to detect.


Author(s):  
Tori Shimizu ◽  
Kenjiro Tadakuma ◽  
Masahiro Watanabe ◽  
Eri Takane ◽  
Masashi Konyo ◽  
...  

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mehtap Safak Boroglu ◽  
Ismail Boz ◽  
Busra Kaya

Abstract In our study, the synthesis of zeolitic imidazolate framework (ZIF-12) crystals and the preparation of mixed matrix membranes (MMMs) with various ZIF-12 loadings were targeted. The characterization of ZIF-12 and MMMs were carried out by Fourier transform infrared spectroscopy analysis, thermogravimetric analysis, scanning electron microscopy (SEM), and thermomechanical analysis. The performance of MMMs was measured by the ability of binary gas separation. Commercial polyetherimide (PEI-Ultem® 1000) polymer was used as the polymer matrix. The solution casting method was utilized to obtain dense MMMs. In the SEM images of ZIF-12 particles, the particles with a rhombic dodecahedron structure were identified. From SEM images, it was observed that the distribution of ZIF-12 particles in the MMMs was homogeneous and no agglomeration was present. Gas permeability experiments of MMMs were measured for H2, CO2, and CH4 gases at steady state, at 4 bar and 35 °C by constant volume-variable pressure method. PEI/ZIF-12-30 wt% MMM exhibited high permeability and ideal selectivity values for H2/CH4 and CO2/CH4 were P H 2 / CH 4 = 331.41 ${P}_{{\text{H}}_{2}/{\text{CH}}_{4}}=331.41$ and P CO 2 / CH 4 = 53.75 ${P}_{{\text{CO}}_{2}/{\text{CH}}_{4}}=53.75$ gas pair.


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