scholarly journals An Integrated Analytical Approach to Define the Compositional and Textural Features of Mortars Used in the Underwater Archaeological Site of Castrum Novum (Santa Marinella, Rome, Italy)

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 268 ◽  
Author(s):  
Luciana Randazzo ◽  
Michela Ricca ◽  
Silvestro Ruffolo ◽  
Marco Aquino ◽  
Barbara Davidde Petriaggi ◽  
...  
Keyword(s):  
Raw Materials ◽  
Archaeological Site ◽  
Complete Characterization ◽  
Point Of View ◽  
Medium Size ◽  
Underwater Environment ◽  
Complementary Techniques

This paper aims to carry out an archaeometric characterization of mortar samples taken from an underwater environment. The fishpond of the archaeological site of Castrum Novum (Santa Marinella, Rome, Italy) was chosen as a pilot site for experimentation. The masonry structures reached the maximum thickness at the apex of the fishpond (4.70 m) and consisted of a concrete conglomerate composed of slightly rough stones of medium size bound with non-hydraulic mortar. After sampling, for a complete characterization of selected mortar fragments, different and complementary techniques (stereomicroscopy, polarizing optical microscopy, and X-ray powder diffraction analysis) were carried out in order to: a) define the minero-petrographic features; and b) investigate their state of conservation. The obtained data allowed the determination of the main constituents of mortars from a compositional point of view. The raw materials, in fact, were quite homogeneous, as well as the ratio in which they were mixed, confirming the typical "recipe" used in Roman times to manufacture hydraulic-type mortars by adding pozzolana. At the same time, it was possible to identify the various degradation processes we were interested in, namely, biological colonization (bio-fouling) that develops differently according to environmental conditions. Based on characterization phase results, the research will help to develop adequate techniques for intervention (innovative tools and methods for the protection of underwater cultural heritage) with particular regard to cleaning and consolidating procedures to be carried out directly in situ.

scholarly journals Characterization of Polysaccharidic Associations for Cosmetic Use: Rheology and Texture Analysis

Cosmetics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 62
Author(s):  
Giovanni Tafuro ◽  
Alessia Costantini ◽  
Giovanni Baratto ◽  
Stefano Francescato ◽  
Laura Busata ◽  
...  
Keyword(s):  
Raw Materials ◽  
Immersion Test ◽  
High Viscosity ◽  
Natural Polymers ◽  
Public Attention ◽  
First Choice ◽  
Wide Range ◽  
Textural Parameters ◽  
Complementary Techniques

As public attention on sustainability is increasing, the use of polysaccharides as rheological modifiers in skin-care products is becoming the first choice. Polysaccharide associations can be used to increase the spreading properties of products and to optimize their sensorial profile. Since the choice of natural raw materials for cosmetics is wide, instrumental methodologies are useful for formulators to easily characterize the materials and to create mixtures with specific applicative properties. In this work, we performed rheological and texture analyses on samples formulated with binary and ternary associations of polysaccharides to investigate their structural and mechanical features as a function of the concentration ratios. The rheological measurements were conducted under continuous and oscillatory flow conditions using a rotational rheometer. An immersion/de-immersion test conducted with a texture analyzer allowed us to measure some textural parameters. Sclerotium gum and iota-carrageenan imparted high viscosity, elasticity, and firmness in the system; carob gum and pectin influenced the viscoelastic properties and determined high adhesiveness and cohesiveness. The results indicated that these natural polymers combined in appropriate ratios can provide a wide range of different textures and that the use of these two complementary techniques represents a valid pre-screening tool for the formulation of green products.

Photoluminescence Excitation Spectroscopy of Carbon-Doped Gallium Nitride

1998 ◽  
Vol 537 ◽  
Author(s):  
E. E. Reuter ◽  
R. Zhang ◽  
T. F. Kuech ◽  
S. G. Bishop
Keyword(s):  
Complete Characterization ◽  
Photoluminescence Excitation ◽  
Yellow Luminescence ◽  
Broad Excitation Band ◽  
Carbon Doped ◽  
Sapphire Substrates ◽  
Red Luminescence ◽  
Unusual Shape

AbstractWe have done a comparative study of carbon-doped GaN and undoped GaN utilizing photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies in order to investigate deep levels involved in yellow luminescence (YL) and red luminescence (RL). When the GaN was excited by above-bandgap light, red luminescence (RL) centered at 1.82 eV was the dominant below-gap PL from undoped GaN, but carbon-doped GaN below-gap PL was dominated by yellow luminescence (YL) centered at 2.2 eV. When exciting PL below the band-gap with 2.4 eV light, undoped GaN had a RL peak centered at 1.5 eV and carbon-doped GaN had a RL peak centered at 1.65 eV. PLE spectra of carbon-doped GaN, detecting at 1.56 eV, exhibited a strong, broad excitation band extending from about 2.1 to 2.8 eV with an unusual shape that may be due to two or more overlapping excitation bands. This RL PLE band was not observed in undoped GaN. We also demonstrate that PL spectra excited by below gap light in GaN films on sapphire substrates are readily contaminated by 1.6-1.8 eV and 2.1-2.5 eV chromium-related emission from the substrate. A complete characterization of the Cr emission and excitation bands for sapphire substrates enables the determination of the excitation and detection wavelengths required to obtain GaN PL and PLE spectra that are free of contributions from substrate emission.

scholarly journals Some considerations on the use of the geoelectric «square» array

1996 ◽  
Vol 39 (1) ◽  
Author(s):  
F. Merlanti ◽  
M. Pavan
Keyword(s):  
Error Term ◽  
Homogeneous Medium ◽  
Archaeological Site ◽  
Point Of View ◽  
Practical Application ◽  
Linear Arrays ◽  
Relative Measurements ◽  
Square Array ◽  
Anisotropy Coefficients

The «square array» is what we may consider to be an unconventional geoelectric configuration since it is not widely used and therefore there are few examples of practical application. The purpose of this research was to verify the operating effectiveness of this configuration in terms of profile and sounding, and the significance of the set of possible measurements and derived parameters. This was also obtained by comparing the relative measurements with the most common linear arrays (Wenner, Schlumberger, tripotential). The experiment was carried out in two different zones. In the first area, corresponding to the archaeological site of Marzabotto (Bologna), the target was represented by wall remnants inserted in a substantially homogeneous medium, from an electrical point of view, and at depths that are less than those of the dimensions of the device used. At the second site, located in the valley of Landrazza (Savona), the situation was very different, with a valley section on a calcareous bedrock filled with poorly classified residual sediments. An overall analysis of the results showed that the square technique is more exhaustive than the classical linear arrangements when performing soundings. Instead, with regard to profile development, it is not as preferred since it involves a greater amount of work without generating improved information. From analysis of the experimental results, considerable doubts arose about the meaning and the use of the anisotropy coefficients and the error term as defined theoretically. These parameters turned out to be of little use with regard to the characterization of the ground anisotropy and for checking the reliability of the measurements.

scholarly journals The standard characterization of the Romanian onion landrace ‘Roșie de Făgăraș’

2016 ◽  
Vol 73 (2) ◽  
pp. 101
Author(s):  
Mihaela Antofie ◽  
Camelia Sand Sava
Keyword(s):  
In Situ Conservation ◽  
Political Support ◽  
Medium Size ◽  
Small Scale ◽  
The European Union ◽  
Market Place ◽  
Food And Agriculture ◽  
Land Cultivation

‘Roșie de Făgăraș’ is a red onion landrace originating from the old region Făgăraș Country situated in South East Transylvania. It was officially included in the National Official Catalogue for cultivars and hybrids in 1952, for almost 50 years, and erased before 2004 without applying in situ conservation measures. However, food security depends on the appropriate management of all genetic resources for food and agriculture (PGRFA). Thus they have to be conserved and sustainable used and efforts have to be done for the recognition of this landrace as a PGRFA and therefore to be maintained "under conservation" into the Official Catalogue. The study focused on analysing data from three localities recognized for cultivating ‘Roșie de Făgăraș’, in order to evaluate morphometric characteristics of mature onion bulbs according to the UPOV Standard TG/46/7, productivity, land cultivation and socio-economic vulnerabilities. The analysis of morphometric measurements results support that ‘Roșie de Făgăraș’ is a medium size red onion that may have the chance to enter the market place, at least at the small scale, according to the current regulatory framework of the European Union regarding the conservation of landraces and provided by: Directive 2008/62/EC, Directive 2009/145/EC and Directive 2010/60/EU. The analysis of productivity, and land cultivation revealed dramatic land use change associated with the decline of cultivated area as following: 76.27% in Mândra, 50% in Recea and 33.34% in Beclean. With an increasing aging population, lack of political support for entering the market place, decrease of landowners cultivating ‘Roșie de Făgăraș’ for trade will increase vulnerability of traditional knowledge related to the conservation of this landrace.

Modified ferron assay for speciation characterization of hydrolyzed Al(III): a precise k value based judgment

2009 ◽  
Vol 59 (4) ◽  
pp. 823-832 ◽  
Author(s):  
Ye Changqing ◽  
Wang Dongsheng ◽  
Wu Xiaohong ◽  
Qu Jiuhui ◽  
John Gregory
Keyword(s):  
Kinetic Constant ◽  
Nonlinear Least Squares ◽  
Precise Determination ◽  
K Value ◽  
First Order ◽  
First Order Kinetics ◽  
Parallel Reactions

The speciation of Al-OH complexes in terms of Ala, Alb and Alc could be achieved by traditional ferron assay and Alb is generally considered as Al13, however, the inherent correlation between them remains an enigma. This paper presents a modified ferron assay to get precise determination of Al13 using nonlinear least squares analysis, and to clarify the correlation between Alb and Al13. Two parallel reactions conforming to pseudo-first-order kinetics can simulate the complicate reactions between polynuclear complexes and ferron successfully. Four types of experimental kinetic constant (k value) of Al-OH complexes can be observed by this method when investigating three typical aluminium solutions. Comparing with the results of 27Al NMR, the species with moderate kinetics around 0.001 s−1 can be confirmed to resemble to Al13 polycation. The other types of kinetics are also well-regulated in partially neutralized aluminium solutions with various OH/Al ratios (b values) in the range 0 ∼ 2.5. It would provide potential means to trace the in-situ formation of Al13 in dilute solutions such as coagulation with Al-based coagulants

In situ structure and force characterization of 2D nano-colloids at the air/water interface

Soft Matter ◽  
2019 ◽  
Vol 15 (42) ◽  
pp. 8475-8482
Author(s):  
Giovanni Li-Destri ◽  
Roberta Ruffino ◽  
Nunzio Tuccitto ◽  
Giovanni Marletta
Keyword(s):  
Quantitative Determination ◽  
Experimental Method ◽  
Water Interface ◽  
Liquid Interfaces ◽  
Interaction Forces ◽  
Air Water Interface

We have developed a novel experimental method, which enables quantitative determination of interaction forces between interfacial nanoparticles as a function of the inter-particle distance at liquid interfaces.

scholarly journals THE FORMULATION OF DRY CURCUMA (CURCUMA XANTHORRHIZA ROXB.) EXTRACT MICROCAPSULES BY SPRAY WET MICROENCAPSULATION TECHNIQUES

2018 ◽  
Vol 11 (3) ◽  
pp. 226
Author(s):  
Samran Samran ◽  
Dalimunthe Dalimunthe ◽  
Dalimunthe Dalimunthe ◽  
Dalimunthe Dalimunthe
Keyword(s):  
Sodium Alginate ◽  
Brown Algae ◽  
Raw Materials ◽  
Light Exposure ◽  
Gastrointestinal Disease ◽  
Dry Weight ◽  
Compressibility Index ◽  
Curcuma Xanthorrhiza

 Objective: Curcuma xanthorrhiza Roxb. was used as hereditary medicinal plant for prevention of liver dysfunction, gastrointestinal disease, fever, and hemorrhoid. Curcuma extract was easy to damage because the light exposure, change of pH, weather and a long period of storage time. The problem can be solved by coating the extract with spray wet microencapsulation (SWM) technique. SWM technique is a method of preparing microcapsules in which a solution, suspension, or emulsion with a charged matrix is sprayed into opposing solution. The aim of this research was to formulate the dry Curcuma extract with SWM technique using sodium alginate as matrix.Methods: Brown algae (Sargassum ilicifolium) was a main resource of alginate acid. It was isolated using HCl 5% to make alginate acid and sodium alginate that was obtained by adding Na2CO3 5% to alginate acid solution. The microencapsulation process of Curcuma extract was done by SWM technique. The formula of Curcuma extract microencapsulation was design into three formulas: F1, F2, and F3. Microcapsules of Curcuma extract were being characterized for color intensity, analysis of scanning electron microscope (SEM), compressibility index, flowing time, and determination of angle repose.Results: The results showed that the higher concentration of sodium alginate used, the dry Curcuma extract microcapsules produced better. Particle size of extract microcapsules of Curcuma extract microcapsules SEM from F1, F2, F3 was 20 μm whereas dry weight of extracted microcapsule of Curcuma grows with increasing concentration of sodium alginate: F1 (0.2%) 19.86±0.11 g, F2 (0.4%) 20.66±0.73, F3 (0.6%) 21.29±0.64. The flowing time of F1, F2, and F3 was 6.92±0.56, 7.42±0.50, and 8.05±0.54 s consecutively.Conclusions: Based on the analysis of the study result, it can be concluded that the raw materials of Curcuma extract can be made by SWM technique using sodium alginate isolated from brown algae, and the characterization of dry Curcuma extract microcapsule of the three formulas met the requirements of the pre-formulation tests for capsule dosage form.

Sensor Placement for Angular Velocity Determination

2005 ◽  
Vol 128 (3) ◽  
pp. 543-547 ◽  
Author(s):  
Guy M. Genin ◽  
Joseph Genin
Keyword(s):  
Angular Velocity ◽  
Rigid Body ◽  
Velocity Vector ◽  
Constraint Equation ◽  
Complete Characterization ◽  
Angular Velocity Vector ◽  
Algebraic Constraint ◽  
Transducer Placement

Velocity transducer placement to uniquely determine the angular velocity of a rigid body is investigated. The angular velocity of a rigid body can be determined with no fewer than five properly placed velocity transducers, if no other types of sensors are present and no algebraic constraint equation involving the angular velocity vector can be written. Complete characterization of the velocity of a rigid body requires six transducers. Choice of transducer placement and orientation requires care, as suboptimal transducer placement can result in data from which the determination of a unique angular velocity vector is impossible. Conditions for successful transducer placement are established, and two examples of adequate transducer placement are presented: an Earth-penetrating projectile, and a bioengineering device for the measurement of head motion.

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