scholarly journals Application of gas analyzers for the control of fuel in the air environment of rocket and space industry enterprises

2021 ◽  
Vol 20 (3) ◽  
pp. 110-118
Author(s):  
A. B. Bulgakov ◽  
S. P. Vashchuk ◽  
R. A. Panshin
Keyword(s):  
Single Channel ◽  
Small Mass ◽  
Rocket Fuel ◽  
Accurate Analysis ◽  
Russian Market ◽  
Space Industry ◽  
Mass Size ◽  
Air Sample ◽  
Derivatives Of ◽  
Instrumental Control

The presented work shows the necessity of organization of individual instrumental control of the content of rocket fuel and its products in the air of rocket-space industry enterprises. No accurate analysis of gas analyzers presented on the Russian market, providing individual instrumental control of concentrations of heptyl and its derivatives in the workplace air is available. Therefore, the task of express, automatic, selective and simultaneous monitoring of heptyl vapors and derivatives of its transformation in the air of industrial premises by one instrument and replacing the imported gas analyzers remains urgent. It is shown that the solution of the posed problem is possible on the basis of the optical absorption method. The requirements to be met by the gas analyzer are formulated. Approximate wavelengths at which simultaneous measurement of concentrations of heptyl and its derivatives in an air sample is possible have been determined. The ways of realization of individual gas analyzers having small mass-size characteristics are outlined. Structural schemes for infra-red gas analyzers have been proposed: multi-channel; single-channel (with frequency modulation of radiation). Tasks for further research are formulated.

scholarly journals Conotoxins as Sensors of Local pH and Electrostatic Potential in the Outer Vestibule of the Sodium Channel

2003 ◽  
Vol 122 (1) ◽  
pp. 63-79 ◽  
Author(s):  
Kwokyin Hui ◽  
Deane McIntyre ◽  
Robert J. French
Keyword(s):  
Lipid Bilayers ◽  
Sodium Channels ◽  
Electrostatic Potential ◽  
Single Channel ◽  
Local Environment ◽  
Bound State ◽  
Channel Changes ◽  
Voltage Dependent ◽  
Charged Ring ◽  
Derivatives Of

We examined the block of voltage-dependent rat skeletal muscle sodium channels by derivatives of μ-conotoxin GIIIA (μCTX) having either histidine, glutamate, or alanine residues substituted for arginine-13. Toxin binding and dissociation were observed as current fluctuations from single, batrachotoxin-treated sodium channels in planar lipid bilayers. R13X derivatives of μCTX only partially block the single-channel current, enabling us to directly monitor properties of both μCTX-bound and -unbound states under different conditions. The fractional residual current through the bound channel changes with pH according to a single-site titration curve for toxin derivatives R13E and R13H, reflecting the effect of changing the charge on residue 13, in the bound state. Experiments with R13A provided a control reflecting the effects of titration of all residues on toxin and channel other than toxin residue 13. The apparent pKs for the titration of residual conductance are shifted 2–3 pH units positive from the nominal pK values for histidine and glutamate, respectively, and from the values for these specific residues, determined in the toxin molecule in free solution by NMR measurements. Toxin affinity also changes dramatically as a function of pH, almost entirely due to changes in the association rate constant, kon. Interpreted electrostatically, our results suggest that, even in the presence of the bound cationic toxin, the channel vestibule strongly favors cation entry with an equivalent local electrostatic potential more negative than −100 mV at the level of the “outer charged ring” formed by channel residues E403, E758, D1241, and D1532. Association rates are apparently limited at a transition state where the pK of toxin residue 13 is closer to the solution value than in the bound state. The action of these unique peptides can thus be used to sense the local environment in the ligand-–receptor complex during individual molecular transitions and defined conformational states.

The EADS Micropack Project: An Intelligent Microsystem Demonstrator for Small Mission Applications

2006 ◽  
Author(s):  
Steven Eckersley ◽  
Josef Schalk ◽  
Martin Kluge
Keyword(s):  
Modular Approach ◽  
Space Applications ◽  
Space Industry ◽  
Future Mission ◽  
Integrated Microsystems ◽  
Mass Size ◽  
Microsystems Technology

The global Micro-electromechanical (MEMS) or Microsystems Technology (MST) market is forecast to keep growing at a phenomenal rate. EADS recognises the potential for this technology to revolutionise the space industry, where it can dramatically reduce mass, size and power requirements and therefore launch costs. This can enable missions that would otherwise have been unfeasibly expensive. Therefore EADS has been developing a novel modular approach to packaging integrated microsystems for space applications called ‘micropacks’. The micropacks include suites of COTS MST sensors, packaged and integrated into a 3D modular multi-layer ceramic package. This introduces flexibility and means that this impressively light and compact micropack technology can be adapted to form the basis as a solution for a range of exciting future mission concepts. In addition, EADS Astrium Ltd. is ensuring that the micropack has the capability to be integrated into a cubesat, should a potential flight opportunity arise. This in turn helps develop the necessary knowhow of MEMS payload integration for future missions.

scholarly journals Derivatization of Methylglyoxal for LC-ESI-MS Analysis—Stability and Relative Sensitivity of Different Derivatives

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2994 ◽  
Author(s):  
Stefan Fritzsche ◽  
Susan Billig ◽  
Robby Rynek ◽  
Ramarao Abburi ◽  
Elena Tarakhovskaya ◽  
...  
Keyword(s):  
Relative Sensitivity ◽  
Accurate Analysis ◽  
Esi Ms ◽  
Ms Analysis ◽  
High Responsiveness ◽  
Biological And Environmental Samples ◽  
Reactive Carbonyl Compounds ◽  
First Time ◽  
Derivatives Of ◽  
Analysis Stability

The great research interest in the quantification of reactive carbonyl compounds (RCCs), such as methylglyoxal (MGO) in biological and environmental samples, is reflected by the fact that several publications have described specific strategies to perform this task. Thus, many reagents have also been reported for the derivatization of RCCs to effectively detect and quantify the resulting compounds using sensitive techniques such as liquid chromatography coupled with mass spectrometry (LC-MS). However, the choice of the derivatization protocol is not always clear, and a comparative evaluation is not feasible because detection limits from separate reports and determined with different instruments are hardly comparable. Consequently, for a systematic comparison, we tested 21 agents in one experimental setup for derivatization of RCCs prior to LC-MS analysis. This consisted of seven commonly employed reagents and 14 similar reagents, three of which were designed and synthesized by us. All reagents were probed for analytical responsiveness of the derivatives and stability of the reaction mixtures. The results showed that derivatives of 4-methoxyphenylenediamine and 3-methoxyphenylhydrazine—reported here for the first time for derivatization of RCCs—provided a particularly high responsiveness with ESI-MS detection. We applied the protocol to investigate MGO contamination of laboratory water and show successful quantification in a lipoxidation experiment. In summary, our results provide valuable information for scientists in establishing accurate analysis of RCCs.

scholarly journals Fast and Automated Segmentation for the Three-Directional Multi-Slice Cine Myocardial Velocity Mapping

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 346
Author(s):  
Yinzhe Wu ◽  
Suzan Hatipoglu ◽  
Diego Alonso-Álvarez ◽  
Peter Gatehouse ◽  
Binghuan Li ◽  
...  
Keyword(s):  
Phase Velocity ◽  
Single Channel ◽  
Left Ventricular ◽  
Superior Performance ◽  
Myocardial Velocity ◽  
Velocity Mapping ◽  
Accurate Analysis ◽  
Shape Information ◽  
Phase Velocity Mapping ◽  
Orthogonal Phase

Three-directional cine multi-slice left ventricular myocardial velocity mapping (3Dir MVM) is a cardiac magnetic resonance (CMR) technique that allows the assessment of cardiac motion in three orthogonal directions. Accurate and reproducible delineation of the myocardium is crucial for accurate analysis of peak systolic and diastolic myocardial velocities. In addition to the conventionally available magnitude CMR data, 3Dir MVM also provides three orthogonal phase velocity mapping datasets, which are used to generate velocity maps. These velocity maps may also be used to facilitate and improve the myocardial delineation. Based on the success of deep learning in medical image processing, we propose a novel fast and automated framework that improves the standard U-Net-based methods on these CMR multi-channel data (magnitude and phase velocity mapping) by cross-channel fusion with an attention module and the shape information-based post-processing to achieve accurate delineation of both epicardial and endocardial contours. To evaluate the results, we employ the widely used Dice Scores and the quantification of myocardial longitudinal peak velocities. Our proposed network trained with multi-channel data shows superior performance compared to standard U-Net-based networks trained on single-channel data. The obtained results are promising and provide compelling evidence for the design and application of our multi-channel image analysis of the 3Dir MVM CMR data.

The Diagnostic Value of CT-guided Percutaneous Co-axial Trans-thoracic Biopsy (PCTTB) and Evaluation of the Pathologic Examination

2019 ◽  
Vol 15 (5) ◽  
pp. 479-488
Author(s):  
Mehmet Hamdi Şahan ◽  
Mikail Inal ◽  
Nuray Bayar Muluk ◽  
Adil Doğan ◽  
Pınar Atasoy
Keyword(s):  
Lower Lobe ◽  
Large Mass ◽  
Small Mass ◽  
Diagnostic Value ◽  
Complication Rates ◽  
Ct Guided ◽  
Mass Size ◽  
Mass Group ◽  
Lung Biopsies ◽  
The Right

<p>Background: We investigated thoracic masses with Computed Tomography (CT)- guided Percutaneous Co-Axial Trans-Thoracic Biopsy (PCTTB). </P><P> Methods: The retrospective data of 86 patients to whom CT-guided PCTTB had been applied were obtained. Eighty-four cases and their pathologic results were included in the study. Localization and appearance of the lesions, pathologic results, and complications were evaluated. </P><P> Results: Diagnostic sensitivity of CT-guided PCTTB was 97.6%. In 60.7% of the cases, malign lesions and, in 39.3% of the cases, benign lesions were diagnosed. The mass size was on average greater than 2 cm, and one mass was detected as being more than &#8805;2 masses. Mainly, irregular contours were observed. Most of the malign tumors were primary malign tumors on both sides (91.7% on the right side and 88.9% on the left side). Squamous Cell Carcinoma (SCC) was the most often detected malign tumor on the right side, and adenocarcinoma was the most often detected malign tumor on the left side. In masses localized on the left inferior lobe, metastasis was often detected. When the number of the mass was &#8805;2 and the mass had the appearance of consolidation, metastasis was usually detected. Small and large masses were mainly localized on right and left upper lobes. In the small mass group, 75.0% of the cases were benign, and, in the large mass group, 64.5% of the cases were malign (p=0.031, &#967;2=4.666). Pneumothorax was the most commonly occurring complication (23.8%). In masses localized on the right lower lobe, the pneumothorax ratio increased in benign masses compared to malign masses. The hemorrhage detection rate was 13.0%, and hemoptysis occurred in 14.2% of the cases. Hemorrhage was detected during 11.8% of the large mass biopsies. In females, hemorrhage occurred more often than in males (p=0.026, r= 0.244). </P><P> Conclusion: CT-guided PCTTB is a safe method to utilize for lung biopsies. Co-axial method increased the diagnostic accuracy of CT-guided percutaneous trans-thoracic biopsies. A single cut also decreased the complication rates.</p>

Data Acquisition and Handling Unit for a Quantitative Use of Electron Energy Loss Spectroscopy

1977 ◽  
Vol 35 ◽  
pp. 232-233 ◽  
Author(s):  
P. Trebbia ◽  
P. Ballongue ◽  
C. Colliex
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Single Channel ◽  
Detection System ◽  
Surface Barrier ◽  
Solid State Detector ◽  
Electrostatic Mirror ◽  
Electron Energy Loss

An effective use of electron energy loss spectroscopy for chemical characterization of selected areas in the electron microscope can only be achieved with the development of quantitative measurements capabilities.The experimental assembly, which is sketched in Fig.l, has therefore been carried out. It comprises four main elements.The analytical transmission electron microscope is a conventional microscope fitted with a Castaing and Henry dispersive unit (magnetic prism and electrostatic mirror). Recent modifications include the improvement of the vacuum in the specimen chamber (below 10-6 torr) and the adaptation of a new electrostatic mirror.The detection system, similar to the one described by Hermann et al (1), is located in a separate chamber below the fluorescent screen which visualizes the energy loss spectrum. Variable apertures select the electrons, which have lost an energy AE within an energy window smaller than 1 eV, in front of a surface barrier solid state detector RTC BPY 52 100 S.Q. The saw tooth signal delivered by a charge sensitive preamplifier (decay time of 5.10-5 S) is amplified, shaped into a gaussian profile through an active filter and counted by a single channel analyser.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Instrumentation for Measurement of Lingual Strength

1968 ◽  
Vol 11 (1) ◽  
pp. 189-193 ◽  
Author(s):  
Lois Joan Sanders
Keyword(s):  
Single Channel ◽  
Displacement Transducer ◽  
Tongue Pressure ◽  
Maximum Pressure ◽  
Research Use ◽  
Direct Writing ◽  
Significant Difference ◽  
Pressure Unit ◽  
Force Displacement ◽  
Consistent Response

A tongue pressure unit for measurement of lingual strength and patterns of tongue pressure is described. It consists of a force displacement transducer, a single channel, direct writing recording system, and a specially designed tongue pressure disk, head stabilizer, and pressure unit holder. Calibration with known weights indicated an essentially linear and consistent response. An evaluation of subject reliability in which 17 young adults were tested on two occasions revealed no significant difference in maximum pressure exerted during the two test trials. Suggestions for clinical and research use of the instrumentation are noted.

Left Ventricular Hypertrophy

2014 ◽  
Vol 19 (2) ◽  
pp. 11-15
Author(s):  
Steven L. Demeter
Keyword(s):  
Risk Factors ◽  
Left Ventricular Hypertrophy ◽  
Ventricular Hypertrophy ◽  
Left Ventricular Mass Index ◽  
Medical Science ◽  
Careful Analysis ◽  
Left Ventricular ◽  
Hypertensive Disease ◽  
Accurate Analysis ◽  
Clear Explanation

Abstract The fourth, fifth, and sixth editions of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) use left ventricular hypertrophy (LVH) as a variable to determine impairment caused by hypertensive disease. The issue of LVH, as assessed echocardiographically, is a prime example of medical science being at odds with legal jurisprudence. Some legislatures have allowed any cause of LVH in a hypertensive individual to be an allowed manifestation of hypertensive changes. This situation has arisen because a physician can never say that no component of LVH was not caused by the hypertension, even in an individual with a cardiomyopathy or valvular disorder. This article recommends that evaluators consider three points: if the cause of the LVH is hypertension, is the examinee at maximum medical improvement; is the LVH caused by hypertension or another factor; and, if apportionment is allowed, then a careful analysis of the risk factors for other disorders associated with LVH is necessary. The left ventricular mass index should be present in the echocardiogram report and can guide the interpretation of the alleged LVH; if not present, it should be requested because it facilitates a more accurate analysis. Further, if the cause of the LVH is more likely independent of the hypertension, then careful reasoning and an explanation should be included in the impairment report. If hypertension is only a partial cause, a reasoned analysis and clear explanation of the apportionment are required.

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