scholarly journals Radiocarbon Dating of Mortars with a Pozzolana Aggregate Using the Cryo2SoniC Protocol to Isolate the Binder

Radiocarbon ◽  
2017 ◽  
Vol 60 (2) ◽  
pp. 617-637 ◽  
Author(s):  
Sara Nonni ◽  
Fabio Marzaioli ◽  
Silvano Mignardi ◽  
Isabella Passariello ◽  
Manuela Capano ◽  
...  
Keyword(s):  
Selection Process ◽  
Archaeological Sites ◽  
Water Origin ◽  
Electron Microscopy Analysis ◽  
Calcite Deposition ◽  
Microscopy Analysis ◽  
The One ◽  
The Masses ◽  
Purification Protocol ◽  
Historical References

AbstractTo date, finding a technique able to effectively isolate the carbon signal from the binder of a mortar is still an open challenge. In this paper, the radiocarbon (14C) dating of one of the most challenging and diffuse types of mortar, the one with pozzolana aggregate, is investigated. Eight mortar samples from three archaeological sites near Rome (Italy) underwent a selection process called Cryo2SoniC. The selected fractions were analyzed by the accelerator mass spectrometry (AMS) 14C technique and compared to known historical references. Additional scanning electron microscopy analysis and petrographic investigations were done, respectively, to check the grain size of the fractions selected by Cryo2SoniC, and further, to characterize the original mortar samples. The masses of carbon yielded from the dated fractions were almost half of those released from some aerial mortars. The 14C dating results were accurate for pozzolana mortars, from buried and unburied structures, with calcination relics and small contamination of secondary calcite. A limitation in the purification protocol was observed on samples with a massive contamination of secondary calcite deposition of ground water origin, occluding porosity and substituting up to the 80% of the original binder matrix.

scholarly journals Collagen Fibril Diameter in Relation to Bone Site and to Calcium/Phosphorus Ratio

2006 ◽  
Vol 6 ◽  
pp. 1109-1113 ◽  
Author(s):  
Panagiotis Berillis ◽  
Dimitris Emfietzoglou ◽  
Margaret Tzaphlidou
Keyword(s):  
Collagen Fibril ◽  
Male Rats ◽  
Structural Parameter ◽  
Mean Values ◽  
Electron Microscopy Analysis ◽  
Calcium Phosphorus ◽  
Order Of Magnitude ◽  
Microscopy Analysis ◽  
The One ◽  
Fibril Diameter

The collagen fibril diameter was measured in cortical bone samples from the femoral neck, rear and front tibia of female and male rats and rabbits using electron microscopy analysis. In most cases, statistically significant differences in mean fibril diameter values between different bone sites were detected. The order of magnitude for the above structural parameter was the same for both genders in both experimental species. In rats, the greatest mean diameter value was that for the femoral, while in rabbits, the one for the rear tibia demonstrating a dependence on bone use and life style. An important aspect was the agreement between these observations and the mean values for Ca/P ratio, as observed in previous experiments, in the same bone sites and animals. Collagen fibril diameter and Ca/P ratio can both serve as indexes of bone quality.

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.

scholarly journals Antiparasitic Properties of Cardiovascular Agents against Human Intravascular Parasite Schistosoma mansoni

2021 ◽  
Vol 14 (7) ◽  
pp. 686
Author(s):  
Raquel Porto ◽  
Ana C. Mengarda ◽  
Rayssa A. Cajas ◽  
Maria C. Salvadori ◽  
Fernanda S. Teixeira ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Screening Strategy ◽  
Early Infection ◽  
Global Public Health ◽  
Parasitic Worm ◽  
Electron Microscopy Analysis ◽  
Health Significance ◽  
Microscopy Analysis

The intravascular parasitic worm Schistosoma mansoni is a causative agent of schistosomiasis, a disease of great global public health significance. Praziquantel is the only drug available to treat schistosomiasis and there is an urgent demand for new anthelmintic agents. Adopting a phenotypic drug screening strategy, here, we evaluated the antiparasitic properties of 46 commercially available cardiovascular drugs against S. mansoni. From these screenings, we found that amiodarone, telmisartan, propafenone, methyldopa, and doxazosin affected the viability of schistosomes in vitro, with effective concentrations of 50% (EC50) and 90% (EC90) values ranging from 8 to 50 µM. These results were further supported by scanning electron microscopy analysis. Subsequently, the most effective drug (amiodarone) was further tested in a murine model of schistosomiasis for both early and chronic S. mansoni infections using a single oral dose of 400 mg/kg or 100 mg/kg daily for five consecutive days. Amiodarone had a low efficacy in chronic infection, with the worm and egg burden reduction ranging from 10 to 30%. In contrast, amiodarone caused a significant reduction in worm and egg burden in early infection (>50%). Comparatively, treatment with amiodarone is more effective in early infection than praziquantel, demonstrating the potential role of this cardiovascular drug as an antischistosomal agent.

scholarly journals Interclass Interference Suppression in Multi-Class Problems

2021 ◽  
Vol 11 (1) ◽  
pp. 450
Author(s):  
Jinfu Liu ◽  
Mingliang Bai ◽  
Na Jiang ◽  
Ran Cheng ◽  
Xianling Li ◽  
...  
Keyword(s):  
Classification Accuracy ◽  
Cross Validation ◽  
Selection Process ◽  
Interference Suppression ◽  
Generalization Ability ◽  
Suppression Effect ◽  
Binary Classifiers ◽  
The One ◽  
Fold Cross Validation ◽  
Validation Experiments

Multi-classifiers are widely applied in many practical problems. But the features that can significantly discriminate a certain class from others are often deleted in the feature selection process of multi-classifiers, which seriously decreases the generalization ability. This paper refers to this phenomenon as interclass interference in multi-class problems and analyzes its reason in detail. Then, this paper summarizes three interclass interference suppression methods including the method based on all-features, one-class classifiers and binary classifiers and compares their effects on interclass interference via the 10-fold cross-validation experiments in 14 UCI datasets. Experiments show that the method based on binary classifiers can suppress the interclass interference efficiently and obtain the best classification accuracy among the three methods. Further experiments were done to compare the suppression effect of two methods based on binary classifiers including the one-versus-one method and one-versus-all method. Results show that the one-versus-one method can obtain a better suppression effect on interclass interference and obtain better classification accuracy. By proposing the concept of interclass inference and studying its suppression methods, this paper significantly improves the generalization ability of multi-classifiers.

scholarly journals Impact Resistance of Epoxy Composites Reinforced with Amazon Guaruman Fiber: A Brief Report

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2264
Author(s):  
Raphael H. M. Reis ◽  
Fabio C. Garcia Filho ◽  
Larissa F. Nunes ◽  
Veronica S. Candido ◽  
Alisson C. R. Silva ◽  
...  
Keyword(s):  
Fiber Composite ◽  
Impact Resistance ◽  
Fiber Composites ◽  
Epoxy Composites ◽  
Impact Performance ◽  
Electron Microscopy Analysis ◽  
Ballistic Properties ◽  
Microscopy Analysis ◽  
Izod Impact ◽  
The Impact

Fibers extracted from Amazonian plants that have traditionally been used by local communities to produce simple items such as ropes, nets, and rugs, are now recognized as promising composite reinforcements. This is the case for guaruman (Ischinosiphon körn) fiber, which was recently found to present potential mechanical and ballistic properties as 30 vol% reinforcement of epoxy composites. To complement these properties, Izod impact tests are now communicated in this brief report for similar composites with up to 30 vol% of guaruman fibers. A substantial increase in impact resistance, with over than 20 times the absorbed energy for the 30 vol% guaruman fiber composite, was obtained in comparison to neat epoxy. These results were statistically validated by Weibull analysis, ANOVA, and Tukey’s test. Scanning electron microscopy analysis disclosed the mechanisms responsible for the impact performance of the guaruman fiber composites.

scholarly journals Electron microscopy analysis of biofilms produced by Staphylococcus aureus exposed to UV-light on the surface of SnO2 thin films

2021 ◽  
Vol 27 (S1) ◽  
pp. 3168-3170
Author(s):  
Hazel Jaynelle Morales-Rodriguez ◽  
Javier Camarillo-Cisneros ◽  
María Alejandra Favila-Pérez ◽  
Alva Rocío Castillo-González ◽  
Celia María Quiñonez-Flores ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Staphylococcus Aureus ◽  
Uv Light ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Sno2 Thin Films

scholarly journals Mineralogy, Geochemistry and Provenance of Coastal Sands from Greece: New Insights on the REE Content of Black Coastal Sands from Aggelochori Area, N.-Greece

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 693
Author(s):  
Argyrios Papadopoulos ◽  
Stylianos Lazaridis ◽  
Afroditi Kipourou-Panagiotou ◽  
Nikolaos Kantiranis ◽  
Antonios Koroneos ◽  
...  
Keyword(s):  
Major And Trace Elements ◽  
Heavy Minerals ◽  
Sea Waves ◽  
Complex Flow ◽  
Fine Grained ◽  
Microscopy Analysis ◽  
Beach Sands ◽  
Geochemical Analyses ◽  
The One ◽  
Black Color

Beach sands from Aggelochori coast line are investigated for their geochemistry and REE content, mineralogy and their provenance. These fluvial sands bear heavy minerals enriched horizons (containing minerals such as magnetite, zircon, ilmenite, hematite, rutile and titanite) that can be distinguished due to their black color and are formed usually due to the action of sea waves that deposit the heavy minerals and remove the lighter ones. After a suitable processing (washing, sieving, drying and magnetic separation) of the samples, the mineral constituents and their presence (wt.%) were estimated by XRD. Among the samples, the one being simultaneously the more fine grained and the more zircon-enriched (as suggested by XRPD data and optical microscopy analysis) has been selected for further geochemical analyses. The major and trace elements contents were compared to previously studied REE enriched beach sands from Kavala and Sithonia. Beach sands from Aggelochori area appear to have relatively low REE contents. Considering the provenance of these sediments, we suggest that these sands, are a product of the erosion of multi-sources, including the near-by Monopigado granite, as well as metamorphic rocks, as indicated by the presence of rutile and both ilmenite and magnetite in some samples. Therefore, there are indications of a complex flow pattern that existed at the paleo-catchment area of the deposition.

scholarly journals Focused Ion Beam (FIB) Preparation and Electron Microscopy Analysis of Individual Microbolometer Pixels

2006 ◽  
Vol 12 (S02) ◽  
pp. 1270-1271
Author(s):  
M Olszta ◽  
J Dougherty ◽  
M Horn ◽  
EC Dickey
Keyword(s):  
Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005

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