scholarly journals On the Influence of the Ammonium Nitrate(V) Provenance on Its Usefulness for the Manufacture of ANFO Type Explosives

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4942
Author(s):  
Andrzej Biessikirski ◽  
Łukasz Kuterasiński ◽  
Michał Dworzak ◽  
Michał Twardosz ◽  
Maciej Tatko ◽  
...  
Keyword(s):  
Ammonium Nitrate ◽  
Cross Section ◽  
Fuel Oil ◽  
Scanning Calorimetry ◽  
Thermogravimetric Analyzer ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Significant Mass Loss ◽  
Tga Analysis ◽  
Significant Mass

Ammonium nitrate fuel oil (ANFO) samples based on fertilizer (AN-F) and ammonium nitrate porous prill (AN-PP) were studied. Tests were carried out using both a thermogravimetric analyzer and differential scanning calorimetry (TGA/DSC). Furthermore, the scanning electron microscopy analysis (SEM) of ammonium nitrate(V) (AN) concerning either their surface or cross-section was performed. Based on the SEM results, it was shown that the surface of AN-F grains was flat and slightly deformed, while the AN-PP surface was wrinkled and deformed. Furthermore, the various steps of thermogravimetric process exhibited continuous AN phase transition according to precise temperatures. From TGA analysis, a significant mass loss was found as a result of ANFO decomposition. Direct comparison of SEM and TGA/DCS data led to the conclusion that ANFO based on AN-F was characterized by lower absorption of FO in contrast to AN-PP.

scholarly journals Thermodynamic Modelling and Microstructural Study of Z-Phase Formation in a Ta-Alloyed Martensitic Steel

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1332
Author(s):  
Florian Riedlsperger ◽  
Bernadette Gsellmann ◽  
Erwin Povoden-Karadeniz ◽  
Oriana Tassa ◽  
Susanna Matera ◽  
...  
Keyword(s):  
Special Focus ◽  
Scanning Calorimetry ◽  
Transmission Electron Microscopy Analysis ◽  
Computational Framework ◽  
Mobility Data ◽  
Interfacial Energies ◽  
Transmission Electron ◽  
Size Number ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

A thermokinetic computational framework for precipitate transformation simulations in Ta-containing martensitic Z-steels was developed, including Calphad thermodynamics, diffusion mobility data from the literature, and a kinetic parameter setup that considered precipitation sites, interfacial energies and dislocation density evolution. The thermodynamics of Ta-containing subsystems were assessed by atomic solubility data and enthalpies from the literature as well as from the experimental dissolution temperature of Ta-based Z-phase CrTaN obtained from differential scanning calorimetry. Accompanied by a comprehensive transmission electron microscopy analysis of the microstructure, thermokinetic precipitation simulations with a wide-ranging and well-documented set of input parameters were carried out in MatCalc for one sample alloy. A special focus was placed on modelling the transformation of MX into the Z-phase, which was driven by Cr diffusion. The simulation results showed excellent agreement with experimental data in regard to size, number density and chemical composition of the precipitates, showing the usability of the developed thermokinetic simulation framework.

Evaluation of intercalation and interaction in in-situ polymerized PLA-HNT bionanocomposites

2020 ◽  
pp. 096739112092779
Author(s):  
P Manju ◽  
P Santhana Gopala Krishnan ◽  
SK Nayak
Keyword(s):  
Electron Microscopy ◽  
Halloysite Nanotubes ◽  
Poly Lactic Acid ◽  
Resonance Spectroscopy ◽  
Hydroxyl Groups ◽  
Scanning Calorimetry ◽  
Transmission Electron Microscopy Analysis ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

We report the in-situ synthesis of poly(lactic acid)–halloysite nanotubes (PLA-HNT) bionanocomposites, with a perspective to improve the interaction between PLA and HNT. Three PLA-HNT bionanocomposites with different HNT weight percentages were synthesized by polycondensation, followed by azeotropic distillation technique. Fourier transform infrared spectroscopy studies indicated the existence of hydrogen bonding between terminal hydroxyl groups of PLA and Si–O–Si groups present in the outer surface of HNT. Wide-angle X-ray diffraction, 29Si- and 27Al-nuclear magnetic resonance spectroscopy analysis confirmed the intercalation of PLA into HNT. Scanning electron microscopy analysis confirmed that there was no significant agglomeration and PLA matrix was found to be embedded with HNT. Transmission electron microscopy analysis also gave ample proof to substantiate the intercalation of PLA chains into HNT. Studies on zeta potential of PLA-HNT bionanocomposites, as compared with PLA, also confirmed the interactions between PLA and HNT. Single melting peak in differential scanning calorimetry analysis indicated the existence of one form of crystalline structure.

scholarly journals PHB/cellulose Fibres Composites Colonization and biodegradation behavior

2018 ◽  
Vol 55 (1) ◽  
pp. 48-53
Author(s):  
Elisabeta Elena Popa ◽  
Maria Rapa ◽  
Calina Petruta Cornea ◽  
Vlad Ioan Popa ◽  
Amalia Carmen Mitelut ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Natural Soil ◽  
Scanning Calorimetry ◽  
Cellulose Fibres ◽  
Soil Burial ◽  
Weight Variation ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Scanning Electron

In this study, newly developed polymeric composites based on poly(3-hydroxybutyrate) (PHB), cellulose fibres (CF) and plasticizer (bis[2-(2-butoxyethoxy)ethyl] adipate) (DBEEA) were subjected both to microorganism�s action in controlled conditions, and to soil�s action by sample burial. The weight loss of PHB based composites at 60 days exposure were determined in comparison with neat PHB. The weight variation for PHB based composites buried in a natural soil at 45 days and 90 days was monitored. DSC-differential scanning calorimetry and SEM -scanning electron microscopy analysis were performed on the tested composites after 90 days of soil burial. It was found that the introduction of cellulose fibres into PHB leads to the increase of biodegradability of composites.

scholarly journals Influence of the Ammonium Nitrate(V) Porous Prill Assortments and Absorption Index on Ammonium Nitrate Fuel Oil Blasting Properties

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3763
Author(s):  
Andrzej Biessikirski ◽  
Mateusz Pytlik ◽  
Łukasz Kuterasiński ◽  
Michał Dworzak ◽  
Michał Twardosz ◽  
...  
Keyword(s):  
Ammonium Nitrate ◽  
Crystal Surface ◽  
Sem Analysis ◽  
Absorption Index ◽  
Fuel Oil ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Velocity Of Detonation ◽  
Blasting Test ◽  
Toxic Fumes

Ammonium nitrate fuel oil (ANFO) samples, which were obtained by blending two different types of ammonium nitrate porous prills (i.e., AN-PP7 and AN-PP8) with fuel oil (FO) were studied. Measurements of structure, crystallinity and morphology were performed using X-ray Diffraction (XRD), Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM), respectively. From the SEM analysis, it was indicated that a “wrinkled” structure characterized the crystal surface of the samples, which were based on two types of ammonium nitrate porous prill. Thermogravimetric analysis and differential scanning calorimetry (TGA/DSC) confirmed that AN-PP7 had a higher absorption index in comparison to AN-PP8. Furthermore, it was shown that continuous AN phase transformations at precise temperatures took place. From the blasting test, it was indicated that the absorption index only had an influence on the content of toxic fumes. However, the velocity of detonation (VOD) depended solely on the ANFO density as well as the total volume of post-blast fumes.

Secondary recycled acrylonitrile–butadiene–styrene and graphene composite for 3D/4D applications: Rheological, thermal, magnetometric, and mechanical analyses

2020 ◽  
pp. 089270572092511 ◽  
Author(s):  
Vinay Kumar ◽  
Rupinder Singh ◽  
IPS Ahuja
Keyword(s):  
Acrylonitrile Butadiene Styrene ◽  
Melt Flow Index ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Twin Screw ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Vibration Sample Magnetometry ◽  
Porosity Analysis ◽  
Butadiene Styrene

This study reports investigation on nano-sized (5–10 nm) graphene (Gr)-reinforced, secondary (2°) recycled acrylonitrile–butadiene–styrene (ABS) as a smart composite material for 3D and 4D applications. Gr was blended (in different weight proportions) with 2°-recycled ABS granules mechanically for selection of composition/proportion after ascertaining rheological property (based upon melt flow index according to ASTM D 1238), thermal stability based upon differential scanning calorimetry, and magnetic property based upon vibration sample magnetometry. The selected compositions/proportions of ABS-Gr composite was further processed with a twin-screw extruder by varying screw temperature and torque. The results of the study suggest that as regards to mechanical properties (peak strength and Shore D hardness) are concerned, the best settings are 20 wt% Gr reinforcement in ABS at a screw temperature 210°C with torque of 0.4 Nm. The corresponding heat capacity and magnetization for the selected composition/proportion was observed as 0.77 J/g and 0.10 × 10−5 emu (+magnetization), 0.080 × 10−5 emu (−magnetization), respectively. The coercivity of the selected compositions ranges from 79.19 Oe to 1260.34 Oe (+coercivity) and 4.64 Oe to 639.50 Oe (−coercivity), whereas the retentivity of the investigated compositions ranges from 2.36 × 10−5 G to 5.44 × 10−4 G (+retentivity) and 4.31 × 10−5 G to 3.48 × 10−5 G (−retentivity). The results have been counter verified based upon optical photo micrographs, porosity analysis, scanning electron microscopy analysis, and energy-dispersive spectroscopy analysis.

Cross-Section Sample Preparation of a Free-Standing Thin-Film Coupon for Transmission Electron Microscopy Analysis

1998 ◽  
Vol 4 (2) ◽  
pp. 128-132 ◽  
Author(s):  
John M. Phelps
Keyword(s):  
Thin Film ◽  
Sample Preparation ◽  
Cross Section ◽  
Free Standing ◽  
Transmission Electron Microscopy Analysis ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Sample Preparation Procedure ◽  
Section Sample

A method for preparing a cross-section sample from a free-standing thin-film coupon suitable for transmission electron microscopy analysis has been successfully developed. The free-standing coupon presented a significant challenge for the preparation of a cross-section sample. A stack consisting of a silicon wafer, thin-film coupon, and glass coverslip was epoxied together, providing both support for thin film and enough surface area to handle the specimen during the sample preparation procedure. The tripod polisher wedge technique was used to thin the cross-section sample to 2 to 5 μm in thickness. This produced a sample with the required structural integrity. Final thinning was accomplished using an ion mill. This technique showed no artifacts introduced from the sample preparation procedure.

Material analysis techniques using the ion mill

1996 ◽  
Vol 54 ◽  
pp. 1034-1035
Author(s):  
J. P. Benedict ◽  
R. M. Anderson ◽  
S. J. Klepeis
Keyword(s):  
Polished Surface ◽  
Surface Material ◽  
Analysis Techniques ◽  
Material Analysis ◽  
Optical Inspection ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Argon Ions ◽  
The Impact ◽  
Scanning Electron

Ion mills equipped with flood guns can perform two important functions in material analysis; they can either remove material or deposit material. The ion mill holder shown in Fig. 1 is used to remove material from the polished surface of a sample for further optical inspection or SEM ( Scanning Electron Microscopy ) analysis. The sample is attached to a pohshing stud type SEM mount and placed in the ion mill holder with the polished surface of the sample pointing straight up, as shown in Fig 2. As the holder is rotating in the ion mill, Argon ions from the flood gun are directed down at the top of the sample. The impact of Argon ions against the surface of the sample causes some of the surface material to leave the sample at a material dependent, nonuniform rate. As a result, the polished surface will begin to develop topography during milling as fast sputtering materials leave behind depressions in the polished surface.

Effects of Various Antioxidant Pretreatment Modalities on Adhesion to Sound and Caries-Affected Dentin: An In Vitro Study

2021 ◽  
pp. 232020682199798
Author(s):  
Beyza Unalan Degirmenci ◽  
Alperen Degirmenci ◽  
Emine Kara
Keyword(s):  
Bond Strength ◽  
In Vitro Study ◽  
Natural Antioxidants ◽  
Microtensile Bond Strength ◽  
Mandibular Molar ◽  
Electron Microscopy Analysis ◽  
Molar Teeth ◽  
Microscopy Analysis ◽  
Two Parameters

Aim: Natural antioxidants were offered as the answer of dentin adhesion issue. The aim of this study is to investigate the effects of proanthocyanidin and lycopene as pretreatment agents on the sound and caries-affected dentin surface on microtensile bond strength and microleakage. Materials and Methods: This study was designed as in vitro because of that 84 mandibular molar teeth were collected. Forty-two of the included teeth were carious teeth, while the other 42 were without caries. Sixty of them were used for microleakage and 24 for microtensile bond strength testing and scanning electron microscopy analysis. The samples were divided into six subgroups randomly according to dentin pretreatments: 5% proanthocyanidin, 5% lycopene, and no antioxidant application. After the restorative procedures, samples were attached to the microtensile tester. Samples were subjected to tensile stress in the load cell until they broke at a speed of 0.5 mm per min. Microtensile bond strength (µTBS) and microleakage test data were analyzed with two-way analysis of variance, Bonferroni correction, and Tamhane’s T2 tests. Results: Two-way variance analysis showed that dentin pretreatment applications, dentin substrate, and the interaction between these two parameters had statistically significant effects on µTBS values ( P < .001). There was no difference between dentin pretreatment applications in terms of microleakage scores ( P > .05). Conclusion: The application of dentin pretreatment with proanthocyanidin is a successful procedure that increases the bond strength in both dentin substrate, while pretreatment with lycopene in caries-affected dentin reduces it.

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