scholarly journals Investigation of a novel nanothermite colloid based on CuO coated CNTs on the thermo-analytical characteristics of 1,3,5-trinitro-1,3,5-triazinane

2021 ◽  
Author(s):  
ahmed elbeih
Keyword(s):  
Energetic Materials ◽  
Electroless Deposition ◽  
Isopropyl Alcohol ◽  
Multiwall Carbon Nanotubes ◽  
Isoconversional Methods ◽  
Mean Value ◽  
Aluminum Nanoparticles ◽  
The Mean ◽  
Multiwall Carbon

Abstract Nanothermite colloid is a promising field of research used to enhance the characteristics of energetic materials. In this study, pre-treated surfaces of multiwall-carbon nanotubes (MWCNTs) were catalysed to help the deposition of a metal and the coating process by copper (Cu) nanoscale layer through electroless deposition. The formed hybrids coated by Cu were treated at 250°C to form MWCNTs coated by CuO. Isopropyl alcohol was used to suspend the coated MWCNTs with aluminium nanoparticles (120 nm) in order to form nano thermite colloid by ultrasonic technique. The presence of CuO layer plays the role of an active oxidizer for the Aluminum nanoparticles. The obtained colloid was incorporated and dispersed in 1,3,5-trinitro-1,3,5-triazinane (RDX). The influence of colloid on RDX decomposition kinetic was evaluated using the isoconversional methods (modified Kissinger-Akahira-Sunose (KAS) methods). The mean value of apparent activation energy was reduced by 37.5 %. This dramatic change in RDX decomposition ascribed trait to the nano-thermite colloid reactivity and the facile integration of colloidal thermite particles with the RDX.

Long-term dynamics and destruction of marsh vegetation in the Kolokolkova Bay of the Barents Sea

2012 ◽  
pp. 66-77 ◽  
Author(s):  
I. A. Lavrinenko ◽  
O. V. Lavrinenko ◽  
D. V. Dobrynin
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Barents Sea ◽  
Mean Value ◽  
Marsh Vegetation ◽  
Composition And Structure ◽  
The Mean ◽  
Species Composition And Structure

The satellite images show that the area of marshes in the Kolokolkova bay was notstable during the period from 1973 up to 2011. Until 2010 it varied from 357 to 636 ha. After a severe storm happened on July 24–25, 2010 the total area of marshes was reduced up to 43–50 ha. The mean value of NDVI for studied marshes, reflecting the green biomass, varied from 0.13 to 0.32 before the storm in 2010, after the storm the NDVI decreased to 0.10, in 2011 — 0.03. A comparative analysis of species composition and structure of plant communities described in 2002 and 2011, allowed to evaluate the vegetation changes of marshes of the different topographic levels. They are fol­lowing: a total destruction of plant communities of the ass. Puccinellietum phryganodis and ass. Caricetum subspathaceae on low and middle marches; increasing role of halophytic species in plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. typicum on middle marches; some changes in species composition and structure of plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. festucetosum rubrae on high marches and ass. Parnassio palustris–Salicetum reptantis in transition zone between marches and tundra without changes of their syntaxonomy; a death of moss cover in plant communities of the ass. Caricetum mackenziei var. Warnstorfia exannulata on brackish coastal bogs. The possible reasons of dramatic vegetation dynamics are discussed. The dating of the storm makes it possible to observe the directions and rates of the succession of marches vegetation.

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

scholarly journals Role of Chemical Biomarkers in Prediction of Intra-Amniotic Infection in Cases with Preterm Premature Rupture of Membrane, Observational Study

2019 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Interleukin 6 ◽  
Mean Value ◽  
Maternal Serum ◽  
P Value ◽  
Subclinical Infection ◽  
Premature Rupture ◽  
Cutoff Value ◽  
The Mean ◽  
Sensitivity Specificity

Introduction: Early recognition of subclinical intra-amniotic infection before development of clinical Chorioamnionitis dramatically improve neonatal outcome before affection of fetal neurological function. Objective: this study was conducted to evaluate the role of procalcitonin and interleukin-6 in early prediction of intrauterine infection in pregnant women with premature rupture of membranes. Methods: This observational prospective cohort study was conducted on 100 pregnant women with preterm premature rupture of membrane (PPROM), Patients were divided into 2 groups: Group I: with normal CRP and WBCs level. Group2: with subclinical infection which was detected by elevated WBCs count >15,000 c/mm3 and / or positive CRP. This group was divided into two groups (Group (II) and Group (III) according to development of Chorioamnionitis. follow up of these patients was done to detect the cutoff value of procalcitonin and interleukin-6 as a predictive indicator of clinical intra-amniotic infection in patients with premature rupture of membrane. Results: This study showed that the mean value of maternal serum PCT concentration was higher in patients with clinical infection than its concentration in patients without infection or with subclinical infection with P-value 0.0001 which is highly significant between the studied cases and with cutoff value was >0.67ng/ml, sensitivity, specificity, PPV, NPV was 88.7%, 42.9%, 79.7% and 60% respectively and the mean value of maternal serum IL-6 concentration was also higher in patients with clinical infection than its concentration in patients without infection or with subclinical infection with P-value 0.001which is highly significant between the studied cases and with cutoff value was >11.1pg/ ml, sensitivity, specificity, PPV, NPV was 67.9%, 61.9%, 81.8% and 43.3% respectively. Conclusion: maternal serum procalcitonin is a good predictor of clinical intra-amniotic infection with good sensitivity, specificity, PPV, NPV which is nearly good as CRP which is better than serum interleukin-6 regarding sensitivity

scholarly journals THE LUCK IN “TALENT VERSUS LUCK” MODELING

2020 ◽  
Vol 23 (03) ◽  
pp. 2050007
Author(s):  
SEAN ELVIDGE
Keyword(s):  
Mean Value ◽  
Maximum Amount ◽  
Random Numbers ◽  
Individual Parameter ◽  
Input Parameters ◽  
The Mean ◽  
Model Variability ◽  
The Impact ◽  
The Relationship

This paper further investigates the Talent versus Luck (TvL) model described by [Pluchino et al. Talent versus luck: The role of randomness in success and failure, Adv. Complex Syst. 21 (2018) 1850014] which models the relationship between ‘talent’ and ‘luck’ on the impact of an individuals career. It is shown that the model is very sensitive to both random sampling and the choice of value for the input parameters. Running the model repeatedly with the same set of input parameters gives a range of output values of over 50% of the mean value. The sensitivity of the inputs of the model is analyzed using a variance-based approach based upon generating Sobol sequences of quasi-random numbers. When using the model to look at the talent associated with an individual who has the maximum capital over a model run it has been shown that the choice for the standard deviation of the talent distribution contributes to 67% of the model variability. When investigating the maximum amount of capital returned by the model the probability of a lucky event at any given epoch has the largest impact on the model, almost three times more than any other individual parameter. Consequently, during the analysis of the model results one must keep in mind the impact that only small changes in the input parameters can have on the model output.

Application of electroless deposition for surface modification of the multiwall carbon nanotubes

2018 ◽  
Vol 702 ◽  
pp. 38-43 ◽  
Author(s):  
M. Kurkowska ◽  
S. Awietjan ◽  
R. Kozera ◽  
E. Jezierska ◽  
A. Boczkowska
Keyword(s):  
Carbon Nanotubes ◽  
Surface Modification ◽  
Electroless Deposition ◽  
Multiwall Carbon Nanotubes ◽  
Multiwall Carbon

Hyperaggregability Of Platelets In Cancer, Especially In Reference To Genesis Of DIC

1981 ◽  
Author(s):  
H Yamazaki ◽  
Y Yahara ◽  
T Motomiya ◽  
K Tanoue ◽  
I Isohisa ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Time Course ◽  
Mean Value ◽  
Activated Partial Thromboplastin Time ◽  
Healthy Controls ◽  
Triggering Mechanism ◽  
Coagulation Abnormalities ◽  
Activated Platelets ◽  
The Mean

To clarify the role of platelets in the genesis of DIC in cancer, platelets of cancer patients with and without DIC were examined. Patients studied were 29 cases with cancer in stomach, 17 in lung, 7 in pancreas, 6 in liver (hepatoma), 6 in throat, nose and jaw, 2 in the gall bladder and bilary duct, 2 in uterus and 1 each in the small bowel, rectum and prostate, and 1 each with osteosarcoma, mesothelioma and chorionepithelioma. All patients were in stage 3 or 4. 105 healthy controls were also studied. They were evaluated on a scale of coagulation abnormalities, one point was given for each of the following criteria full-filled, and the score (0 to 4) was used. 1. Platelet count<150xl03Anl. 2. Prothrombin time prolonged more than 1 sec over control and/or activated partial thromboplastin time prolonged more than 10 sec over control. 3. Fibrinogen<250 mg/dl (mean fibrinogen value of the cancer patients minus 1 SD). 4. FDP>20 µg/ml. The patients were distributed with 27 % for score 0, 38 % for 1, 20 % for 2, 7 % for 3 and 8 % for 4. Degrees of abnormality in groups with scores of 3 and 4 were significant when compared to scores 0 and 1, but score 2 was not clearly distinguishable. Platelet mode volume in score 4 was smaller than the other groups. Platelet aggregation by adrenaline and ADP decreased in score 3 and 4, while it increased significantly in score 0 and 1 respectively (P<0.01 -0.05). The mean value of plasma β-TG in the cancer patients as a whole (44±24 ng/ml) was significantly higher than that of control (22±13 ng/ml)(P<0.01). PF4 showed the same tendency. During the time course of the disease, hyperaggrega- bility of platelets associated with increases in β-TG and PF4 was observed before an appearance of DIC syndrome in several cases. The results suggest the existence of hyperfunction of platelets in cancer patients and the possibility of triggering mechanism of such activated platelets in the genesis of DIC in cancer.

Role of Multiwall Carbon Nanotubes (MWCNT) on Electrical Conductivity of Polymer Composite as Alternative Materials for Bipolar Plate Fuel Cell

2013 ◽  
Vol 737 ◽  
pp. 183-190 ◽  
Author(s):  
Anne Zulfia ◽  
Sutopo ◽  
Bangkit Indriyana ◽  
M.E. Albar ◽  
S. Rohman
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Multiwall Carbon Nanotubes ◽  
Material Design ◽  
Bipolar Plate ◽  
Multiwall Carbon Nanotube ◽  
Crucial Component ◽  
Carbon Nano Tube ◽  
Multiwall Carbon

Polypropylene can be improved an electrical conductivity by addition of carbon and multiwall carbon nanotube (MWCNT) as well as combination with copper (Cu) powder. Multiwall carbon nanotube used from 0.1 wt%, 0.5 wt% to 1 wt% while the addition of Cu powder into PP/C was various from 0.1 wt%, 0.2wt% to 0.5wt% respectively. This research focuses on material design of composite based on polymer and carbon to improve an electrical conductivity according to electrical conductivity requirement for bipolar plate. Bipolar plate is one of the components in PEMFC constituted a crucial component that collects and transfers electron from the anode to the cathode, therefore it should possess high electrical conductivity. The main discussion in this research is to analyze the role of multiwall carbon nano tube (MWCNT) and copper on electrical conductivity of polymer composites produced. Functional groups analysis using Fourier Transform Infrared Spectroscopy (FTIR) was also carried out to investigate whether carbon has been mixed perfectly within polypropylene. It is found that the effect of adding a small amount of MWCNT and Cu have improved their electrical conductivity of composites up to 15.62 S/cm.

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