Controlling foamability of polypropylene/γ-irradiated ethylene acrylic elastomer blends by extent of crosslinking and domain microstructure of elastomer

2021 ◽  
pp. 009524432110588
Author(s):  
Anindya Dutta ◽  
Debjyoti Banerjee ◽  
Anup K. Ghosh
Keyword(s):  
Gamma Radiation ◽  
Domain Size ◽  
Melt Mixing ◽  
Screw Speed ◽  
Batch Mode ◽  
Morphological Attributes ◽  
Density Reduction ◽  
Different Temperatures ◽  
The Individual ◽  
Foaming Temperature

Foams of polypropylene/elastomer blends can often lead to softer foams which may not be desirable every time. Incorporating rigidity to the foams can often be made possible by preferentially crosslinking the elastomer phase prior to blending. Although foamability of polypropylene/elastomer blends has been understood in the scientific community, the influence of the extent of crosslinking in the elastomer phase is not yet understood well. The purpose of this investigation is to identify the influence of the extent of elastomer crosslinking and the blend morphological attributes (achieved by varying screw speed during melt mixing) on foamability of polypropylene/partially crosslinked elastomer blends. Crosslinking of ethylene-acrylic elastomer is carried out using gamma radiation with several doses (0, 12.5, 25, 50 kGy) before melt blending and, subsequently, 10 wt.% of the irradiated elastomers (prior optimized) are mixed with polypropylene in a micro-compounder at three different screw speeds. The microstructure development in blends is characterized by scanning electron microscopy. Frequency sweep rheological analysis is done for selected blends to identify the ease of foamability among the series of blends. Foaming of blends is done with supercritical carbon dioxide in batch mode at three different temperatures. The density reduction along with the microcellular morphology development of blends with foaming is analyzed with the screw speed, the extent of crosslinking, and foaming temperature; furthermore, the individual input parameters (the elastomer domain size, controlled by the screw speed and the extent of crosslinking, controlled by gamma radiation dose) are optimized based on the foam morphology. A uniform and good foamability were achieved at 155 and 160°C for blends with elastomers, irradiated at 12.5 and 25 kGy radiation doses. The lowest density foam (0.37 g/cc) was obtained for polypropylene with 12.5 kGy irradiated crosslinked elastomer mixed at 200 rpm at 160°C foaming temperature. The final elastomer domain dispositions within the foam morphologies are characterized and the plausible foaming mechanism is proposed.

scholarly journals III. Investigations of the specific heat of solid bodies

1865 ◽  
Vol 155 ◽  
pp. 71-202 ◽  
Keyword(s):  
Specific Heat ◽  
Thermal Action ◽  
General View ◽  
Specific Heats ◽  
General Law ◽  
Different Temperatures ◽  
The Times ◽  
The Individual ◽  
Solid Bodies

I. About the year 1780 it was distinctly proved that the same weights of different bodies require unequal quantities of heat to raise them through the same temperature, or on cooling through the same number of thermometric degrees, give out unequal quantities of heat. It was recognized that for different bodies the unequal quantities of heat, by which the same weights of different bodies are heated through the same range, must be determined as special constants, and considered as characteristic of the individual bodies. This newly discovered property of bodies Wilke designated as their specific heat , while Crawford described it as the comparative heat, or as the capacity of bodies for heat . I will not enter upon the earliest investigations of Black, Irvine, Crawford, and Wilke, with reference to which it may merely be mentioned that they depend essentially on the thermal action produced when bodies of different temperatures are mixed, and that Irvine appears to have been the first to state definitely and correctly in what manner this thermal action (that is, the temperature resulting from the mixture) depends on the original temperature, the weights, and the specific heats of the bodies used for the mixture. Lavoisier and Laplace soon introduced the use of the ice-calorimeter as a method for determining the specific heat of bodies; and J. T. Mayer showed subsequently that this determination can be based on the observation of the times in which different bodies placed under comparable conditions cool to the same extent by radiation. The knowledge of the specific heats of solid and liquid bodies gained during the last century, and in the first sixteen years of the present one, by these various methods, may be left unmentioned. The individual determinations then made were not so accurate that they could be compared with the present ones, nor was any general conclusion drawn in reference to the specific heats of the various bodies. 2. Dulong and Petit’s investigations, the publication of which commenced in 1818, brought into the field more accurate determinations, and a general law. The investigations of the relations between the specific heats of the elements and their atomic weights date from this time, and were afterwards followed by similar investigations into the relations of the specific heats of compound bodies to their composition. In order to give a general view of the results of these investigations, it is desirable to present, for the elements mentioned in the sequel, a synopsis of the atomic weights assumed at different times, and of certain numbers which stand in the closest connexion with these atomic weights.

scholarly journals Effect of Gamma Radiation on Characteristic of bipolar junction Transistors (BJTs )

2021 ◽  
pp. 1-9
Author(s):  
Abdenabi Ali Elamin ◽  
Waell H Alawad
Keyword(s):  
Gamma Radiation ◽  
Power Supplies ◽  
Strong Increase ◽  
Bipolar Junction Transistors ◽  
Bipolar Junction Transistor ◽  
Before And After ◽  
Junction Transistor ◽  
The Individual ◽  
Silicon Transistor ◽  
Different Doses

This paper describes the effects of 60Cogamma radiation hardness of characteristic and parameters of Bipolar Junction Transistors in order to analyze the performance changes of the individual devices used in nuclear field. Bipolar Junction Transistor (BJT) of the type (BC-301) (npn) silicon, Transistor was irradiated by gamma radiation using 60Cosource at different doses (1, 2, 3, 4, and 5) KGy. The characteristics and parameter of Bipolar Junction Transistor was studied before and after irradiated by using Transistor Characteristics Apparatus with regulated power supplies. Obtained result showed that, the saturation voltage VCE(sat) of Bipolar Junction Transistor decreased because of the gain degradation of the transistor and increased silicon resistivity, Another parameter of a bipolar junction transistor affected by ionizing radiation is a collector-base leakage current, a strong increase of the current is caused by the build-up charge near the junction.

scholarly journals Compatible Mixture of Bacterial Antagonists Developed to Protect Potato Tubers from Soft Rot Caused by Pectobacterium spp. and Dickeya spp.

Plant Disease ◽  
2019 ◽  
Vol 103 (6) ◽  
pp. 1374-1382 ◽  
Author(s):  
Dorota M. Krzyzanowska ◽  
Tomasz Maciag ◽  
Joanna Siwinska ◽  
Marta Krychowiak ◽  
Sylwia Jafra ◽  
...  
Keyword(s):  
Soft Rot ◽  
Synergistic Activity ◽  
Potato Tubers ◽  
Bacterial Antagonists ◽  
Screening Protocol ◽  
Different Temperatures ◽  
Commercial Applications ◽  
The Individual ◽  
Tissue Maceration ◽  
Disease Pressure

Possibilities to protect potato tubers from rotting caused by Soft Rot Pectobacteriaceae (SRP) under disease favoring conditions were investigated using compatible mixtures of bacterial antagonists and tested with a newly developed stepwise efficacy-based screening protocol. Twenty-two bacterial antagonists were evaluated against a combination of five Pectobacterium and Dickeya strains representing species and subspecies most often associated with potato soft rot in Europe. To enable potential synergistic activity, the antagonists were initially tested against the combination of pathogens in 15 random mixtures containing up to 5 antagonists each. Three mixtures (M2, M4, and M14) out of 15 tested reduced tuber tissue maceration due to soft rot. The individual antagonists derived from M2, M4, and M14 mixtures were tested on potato slices and whole tuber injection assays. These five strains (S. plymuthica strain A294, E. amnigenus strain A167, R. aquatilis strain H145, S. rubidaea strain H440, and S. rubidaea strain H469) were combined to develop a tailored biological control mixture against potato soft rot. The new mixture, designated the Great Five (GF), was tested on seed potato tubers vacuum infiltrated with antagonists and subsequently with the combination of five SRP pathogens. In these experiments, the GF mixture provided stable protection of inoculated potato tubers, reducing soft rot by 46% (P = 0.0016) under high disease pressure conditions. The A294, A167, H145, H440, and H469 antagonists were characterized for features important for viable commercial applications including growth at different temperatures, resistance to antibiotics, and potential toxicity toward Caenorhabditis elegans. The implications for control of soft rot caused by SRP with the use of the GF mixture of antagonists are discussed.

Radiation Situation at the Tailing Dump of the Stepnogorsk Mining-Chemical Combine and Adjacent Territories. Message I

2018 ◽  
Vol 63 (1) ◽  
pp. 40-47 ◽  
Author(s):  
П. Казымбет ◽  
P. Kazymbet ◽  
М. Бахтин ◽  
M. Bahtin ◽  
Е. Кашкинбаев ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Specific Activity ◽  
Negative Impact ◽  
Road Construction ◽  
Field Work ◽  
Research Field ◽  
Effective Radiation Dose ◽  
Tailing Dump ◽  
Local Areas ◽  
The Individual

Purpose: Assessment of the radiation situation at the tailing dump of the Stepnogorsk Mining-Chemical Combine (SMCC) and the settlements around. Material and methods: The tailing dumps of the SMCC and the settlements near located of Aksu, Kvartsytka and Zavodskaya were objects of the radioecological research. Field expedition studies were performed during the summer period and consisted in carrying out a detailed gamma survey of the territory of the investigated objects and settlements, sampling of surface waters, vegetation, surface and layered soil samples. In settlements, along with sampling and studying the gamma background, the equivalent equilibrium volume activity of radon daughters in residential and industrial premises was determined. To determine the concentrations of the studied radionuclides a background was selected, within which the levels of their global deposition were studied. To calculate the individual effective radiation dose of the population the National Radiation Protection Board methodology was used as the basis. Results: In the northern part of the tailing dump of the SMCC in the adjoining territory, a radioactive contamination site was found where the specific activity values for 226Ra, 232Th and 210Pb reach values of 1500–2000 Bq/kg. On the territory of the Aksu settlement, 5 local areas with the area from 25 to 1000 m2 were found, with the intensity of ambient dose equivalent of gamma radiation from 0.39 to 0.86 µSv/h. In the Zavodskaya village, two areas with increased levels of gamma radiation intensity were identified. Conclusion: The obtained results of field work and laboratory analytical studies testify to the negative impact of the tailing dump of the SMCC on the environment of adjacent territories, expressed in contamination of soil, water and vegetation with radionuclides. The nature of the abnormal areas on the territory of the settlements of Aksu and Zavodskaya excludes their origin from the tailing dump of the SMCC. The appearance of these areas of contamination may be due to the use of materials of the 3rd class in sanitary and hygienic standards for improvement and road construction. The probable annual effective dose for the population living in the radioactive local areas of the Aksu ~6.5 mSv/year, at the normal rate of 1 mSv/year from man-made radiation sources.

Ion–ion–solvent interactions in aqueous ionic cosolvent systems. III. Thermodynamics of hydrogen bromide and hydrogen iodide from water to aqueous solutions of sodium nitrate from emf measurements at different temperatures and the structuredness of the solvents

1987 ◽  
Vol 65 (12) ◽  
pp. 2843-2848
Author(s):  
Sibaprasad Rudra ◽  
Himansu Talukdar ◽  
Kiron K. Kundu
Keyword(s):  
Sodium Nitrate ◽  
Structural Changes ◽  
Hydrogen Bromide ◽  
Scaled Particle Theory ◽  
Relative Order ◽  
Emf Measurements ◽  
Solvent Interactions ◽  
Different Temperatures ◽  
Composition Profiles ◽  
The Individual

Standard free energies [Formula: see text] and entropies [Formula: see text] of transfer of hydrogen bromide and iodide from water to the aqueous 1, 2, and 4 m of sodium nitrate have been determined by measuring the emf's of the cell: Pt, H2(g, 1 atm)/KOH(m1), KX(m2), solvent/AgX–Ag where X = Br or I at five equidistant temperatures ranging from 15–35°C. [Formula: see text] values of HBr, HI as well as that of HCl obtained from earlier paper and particularly of the individual ions [Formula: see text](i), obtained by use of modified TATB assumption reported earlier and also [Formula: see text](i) obtained after correcting for "cavity" effect and Born-type electrostatic effect estimated tentatively by the scaled particle theory (SPT) and simple Bom equation, respectively, reveal the relative order of stabilisation of Cl−, Br−, and I− ions. Analysis of [Formula: see text]–composition profile (X = Cl, Br, and I) exhibits a characteristic "maxima" around 1.5 m NaNO3 with the relative order HI > HBr > HCl in the region of maxima. Moreover, dissection of [Formula: see text] values into the individual ion contributions by use of the modified TATB assumption reported earlier, results in the characteristic "maxima" around 1.5 m NaNO3 in [Formula: see text] or [Formula: see text]–composition profiles for H+ and "minima" for Cl−, Br−, and I−. The results are discussed in terms of ion–ion–solvent interactions as well as the structural changes of the solvents.

scholarly journals Electronic Properties and Density of States of Self-Assembled GaSb/GaAs Quantum Dots

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
T. Nowozin ◽  
A. Wiengarten ◽  
L. Bonato ◽  
D. Bimberg ◽  
Wei-Hsun Lin ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Density Of States ◽  
Deep Level ◽  
Material System ◽  
A Value ◽  
Capacitance Voltage ◽  
Different Temperatures ◽  
Self Assembled ◽  
Transient Spectroscopy ◽  
The Individual

The electronic properties of a self-assembled GaSb/GaAs QD ensemble are determined by capacitance-voltage (C-V) and deep-level transient spectroscopy (DLTS). The charging and discharging bias regions of the QDs are determined for different temperatures. With a value of 335 (±15) meV the localization energy is rather small compared to values previously determined for the same material system. Similarly, a very small apparent capture cross section is measured (1·10−16 cm2). DLTS signal analysis yields an equivalent to the ensemble density of states for the individual energies as well as the density function of the confinement energies of the QDs in the ensemble.

Processing of Layered Hydroxyapatite Ceramic Composites

2011 ◽  
Vol 275 ◽  
pp. 143-146 ◽  
Author(s):  
Rumana Sultana ◽  
Jing Zhou Yang ◽  
Xiao Zhi Hu
Keyword(s):  
Structural Properties ◽  
Sol Gel ◽  
Ceramic Composites ◽  
Mechanical Tests ◽  
Porous Coating ◽  
Machined Surface ◽  
Hydroxyapatite Ceramic ◽  
Ha Coating ◽  
Different Temperatures ◽  
The Individual

Layered hydroxyapatite (HA) based ceramic composites consisting of a strong ceramic composite core, 3 mol% yttrium stabilized zirconia (3Y-TZP) with 30 or 40 vol% HA, and a HA-rich porous coating were fabricated using a coating deposition and co-sintering process in the present study. The aim is to develop HA-based bio-ceramic composites that retain the bio-compatibility of HA and the preferred scaffold structure, but have much improved structural properties required for implants. Two different coating techniques, sol-gel derive HA coating and HA solution coating, have been used to deposit the HA coating on the strong HA-containing 3Y-TZP core, which has been pre-sintered at 900°C and has a green-machined surface finish. The upper limit for the final sintering of the layered ceramic composites is set at 1,350°C based on the individual sintering properties of HA and 3Y-TZP. SEM observations have been conducted on the coating surface, sectioned surface of coating and substrate/core to characterize the microstructures of coating and substrate and their interface. Preliminary mechanical tests and XRD tests are also performed to characterise the structural properties at different temperatures.

scholarly journals Soluble Solids and Simple Sugars Measurement in Intact Mango Using Near Infrared Spectroscopy

2008 ◽  
Vol 18 (3) ◽  
pp. 410-416 ◽  
Author(s):  
Stephen R. Delwiche ◽  
Weena Mekwatanakarn ◽  
Chien Y. Wang
Keyword(s):  
Standard Error ◽  
Quality Evaluation ◽  
Near Infrared ◽  
Wavelength Region ◽  
Nir Spectroscopy ◽  
Nondestructive Method ◽  
Soluble Solids ◽  
Least Squares Regression ◽  
Different Temperatures ◽  
The Individual

A rapid, reliable, and nondestructive method for quality evaluation of mango (Magnifera indica) fruit is important to the mango industry for international trade. The objective of this study was to determine the potential of near-infrared (NIR) spectroscopy to predict soluble solids content (SSC) and individual and combined concentrations of sucrose, glucose, and fructose nondestructively in mango. Mature mangoes at two different temperatures (15 °C and 20 °C) were measured by NIR interactance (750–1088 nm wavelength region analyzed) over an 11-day period, starting when the fruit were underripe and extending to a few days past optimal ripeness. Partial least squares regression was used to develop models for SSC, individual sugar concentration, and the sum of the concentrations of the three sugars. Such analyses yielded calibration equations with R2 = 0.77 to 0.88 (SSC), 0.75 (sucrose), 0.67 (glucose), 0.70 (fructose), and 0.82 (sum); standard error of calibration = 0.56 to 0.90 (SSC), 10.0 (sucrose), 0.9 (glucose), 4.5 (fructose), and 10.4 (sum); and standard error of cross-validation = 0.93 to 1.10 (SSC), 15.6 (sucrose), 1.4 (glucose), 6.9 (fructose), and 16.8 (sum). When the SSC calibration was applied to a separate validation set, the standard error of performance ranged from 0.94% to 1.72%. These results suggest that for assessment of mango ripeness, NIR SSC calibrations are superior to the NIR calibrations for any of the individual sugars. This nondestructive technology can be used in the screening and grading of mangoes and in quality evaluation at wholesale and retail levels.

scholarly journals Network Simulation of a Transportation System Based on Accelerating Moving Walkway for Efficient and Sustainable Cities

2019 ◽  
Vol 8 (4) ◽  
pp. 10463-10467
Keyword(s):  
Network Simulation ◽  
Transportation System ◽  
Transportation Systems ◽  
Sustainable Cities ◽  
Batch Mode ◽  
The Public ◽  
The World ◽  
The Difference ◽  
The Individual

Many transportation systems were developed across the world for rapid transportation of pedestrians in both congested and sustainable cities. This leads to the development of the individual place or area for sure. Perhaps a bit of traffic cannot be controlled at this moment even though many transportation systems were installed as discussed. Accelerating moving walkways are one of the premium techniques involved in the present scenario which has an immense stage of operation in this advanced world. Previous Articles discussed the difference between AMW to other transportation systems, now this paper involves the methodology of this system how the public can transform from one place to another place in an easy way. Here the system prepared in a batch mode transportation technique where limited pedestrians can only be transformed under some parameters like weight, persons and consumption of place. The plots of different speeds were developed using MATLAB and a sample model was drawn in CREO.

scholarly journals Biological Treatment of Wastewater from Pyrolysis Plant: Effect of Organics Concentration, pH and Temperature

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 336
Author(s):  
Luca Di Palma ◽  
Irene Bavasso ◽  
Mauro Capocelli ◽  
Paolo De Filippis ◽  
Vincenzo Piemonte
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Biological Treatment ◽  
Order Kinetic ◽  
Batch Mode ◽  
Mean Values ◽  
Wood Pyrolysis ◽  
Toc Removal ◽  
Order Kinetic Model ◽  
Different Temperatures

The biological treatment of the aqueous residue produced during poplar wood pyrolysis was investigated. The biological treatment experiments were carried out at two different pH conditions (controlled at 7, uncontrolled) in batch mode at three different temperatures (15 °C, 25 °C and 30 °C) and initial total organic carbon of the water ranging from 800 mg/L to 2800 mg/L. Results show that a substantial removal of organic carbon could be achieved in aerobic conditions after biomass acclimation. After 72 h of treatment, total organic carbon (TOC) removal mean values of 49.47% and 53.03% were observed at 30 °C for solution at 1400 and 2000 mg/L initial TOC, respectively. In the case of 1400 mg/L, a further mineralization (61.80%) was achieved during 144 h of treatment, by using a two-step process. A kinetic study of the process was also made, showing that organics mineralization followed a first-order kinetic model.

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