A new computational strategy to calculate the edge energy of a relaxed step. Calcite (CaCO3) as a case study

CrystEngComm ◽  
2021 ◽  
Author(s):  
Marco Bruno ◽  
Dino Aquilano
Keyword(s):  
Step Edge ◽  
Crystalline Materials ◽  
Computational Strategy

Determination of the step edge energy, ρ (J/m), is a very difficult task. For this reason, very few theoretical estimates of the edge energies of crystalline materials exist. Nowadays, ρ...

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

The Calculation of Turbulent Diffusion Coefficients in Aquatic Ecosystems

2019 ◽  
Vol 70 (11) ◽  
pp. 3903-3907
Author(s):  
Galina Marusic ◽  
Valeriu Panaitescu
Keyword(s):  
Transport Equation ◽  
Turbulent Diffusion ◽  
Diffusion Coefficients ◽  
Aquatic Ecosystems ◽  
Specific Area ◽  
Left Bank ◽  
The Right ◽  
Prut River

The paper deals with the issues related to the pollution of aquatic ecosystems. The influence of turbulence on the transport and dispersion of pollutants in the mentioned systems, as well as the calculation of the turbulent diffusion coefficients are studied. A case study on the determination of turbulent diffusion coefficients for some sectors of the Prut River is presented. A new method is proposed for the determination of the turbulent diffusion coefficients in the pollutant transport equation for specific sectors of a river, according to the associated number of P�clet, calculated for each specific area: the left bank, the right bank and the middle of the river.

A new computational strategy to calculate the surface energy of a dipolar crystal surface

CrystEngComm ◽  
2021 ◽  
Author(s):  
Marco Bruno ◽  
Stefano Ghignone
Keyword(s):  
Dipole Moment ◽  
Surface Energy ◽  
Energy Surface ◽  
Crystal Surface ◽  
Computational Strategy

Determination of the energy surface, γ_((hkl)) (J/m2), of crystal polar faces is a very difficult task, for the presence of a dipole moment perpendicular to these surfaces that prevents the...

scholarly journals Investigations on historical monuments’ deterioration through chemical and isotopic analyses: an Italian case study

2021 ◽  
Author(s):  
Maria Ricciardi ◽  
Concetta Pironti ◽  
Oriana Motta ◽  
Rosa Fiorillo ◽  
Federica Camin ◽  
...  
Keyword(s):  
Potassium Nitrate ◽  
Sewage Water ◽  
X Ray Diffraction ◽  
Italian Case ◽  
Historical Monuments ◽  
Isotopic Analyses ◽  
Historic Centre ◽  
The Church

AbstractIn this paper, we analysed the efflorescences present in the frescos of a monumental complex named S. Pietro a Corte situated in the historic centre of Salerno (Campania, Italy). The groundwater of the historic centre is fed by two important streams (the Rafastia and the Fusandola) that can be the sources of water penetration. The aims of this work are to (i) identify the stream that reaches the ancient frigidarium of S. Pietro a Corte and (ii) characterize the efflorescences on damaged frescos in terms of chemical nature and sources. In order to accomplish the first aim, the water of the Rafastia river (7 samples) and the water of the Fusandola river (7 samples) were analysed and compared with the water of a well of the Church (7 samples). The ionic chromatography measurements on the water samples allowed us to identify the Rafastia as the river that feeds the ancient frigidarium of S. Pietro a Corte. To investigate the nature and the origin of the efflorescences (our second aim), anionic chromatography analyses, X-ray diffraction measurements, and the isotopic determination of nitrogen were performed on the efflorescences (9 samples) and the salts recovered from the well (6 samples). Results of these analyses show that efflorescences are mainly made of potassium nitrate with a δ15N value of + 9.3 ± 0.2‰. Consequently, a plausible explanation for their formation could be the permeation of sewage water on the walls of the monumental complex.

Chemical sensing failed by aggregation-caused quenching? A case study enables liquid/solid two-phase determination of N2H4

2021 ◽  
Vol 415 ◽  
pp. 128975
Author(s):  
Xiangqian Li ◽  
Mengqing Li ◽  
Yuze Chen ◽  
Gongxi Qiao ◽  
Qian Liu ◽  
...  
Keyword(s):  
Chemical Sensing ◽  
Phase Determination ◽  
Two Phase

The impact of acid hydrolysis conditions on carbohydrate determination in lignocellulosic materials: a case study with Eucalyptus globulus bark

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ricardo Jorge Oliveira ◽  
Bruna Santos ◽  
Maria J. Mota ◽  
Susana R. Pereira ◽  
Pedro C. Branco ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Eucalyptus Globulus ◽  
Industrial Processes ◽  
Lignocellulosic Materials ◽  
Optimal Conditions ◽  
Hydrolysis Conditions ◽  
The Impact ◽  
Eucalyptus Bark

Abstract Lignocellulosic biomass represents a suitable feedstock for production of biofuels and bioproducts. Its chemical composition depends on many aspects (e.g. plant source, pre-processing) and it has impact on productivity of industrial bioprocesses. Numerous methodologies can be applied for biomass characterisation, with acid hydrolysis being a particularly relevant step. This study intended to assess the most suitable procedures for acid hydrolysis, taking Eucalyptus globulus bark as a case study. For that purpose, variation of temperature (90–120 °C) was evaluated over time (0–5 h), through monosaccharides and oligosaccharides contents and degradation. For glucose, the optimal conditions were 100 °C for 2.5 h, reaching a content of 48.6 wt.%. For xylose, the highest content (15.2 wt.%) was achieved at 90 °C for 2 h, or 120 °C for 0.5 h. Maximum concentrations of mannose and galactose (1.0 and 1.7 wt.%, respectively) were achieved at 90 and 100 °C (2–3.5 h) or at 120 °C (0.5–1 h). These results revealed that different hydrolysis conditions should be applied for different sugars. Using this approach, total sugar quantification in eucalyptus bark was increased by 4.3%, which would represent a 5% increase in the ethanol volume produced, considering a hypothetical bioethanol production yield. This reflects the importance of feedstock characterization on determination of economic viability of industrial processes.

scholarly journals Mitigating natural events to avoid disaster in public school buildings: seismic retrofitting of SDN 42 Korong Gadang

2018 ◽  
Vol 229 ◽  
pp. 02021
Author(s):  
James Mwangi ◽  
Laura Putri ◽  
Listhbeth Collins
Keyword(s):  
School Facilities ◽  
Seismic Retrofitting ◽  
Building Structures ◽  
National Agency ◽  
Electrical Grid ◽  
The North ◽  
Australian Plate ◽  
West Sumatra

With over 50 million students, Indonesia has the fourth largest education system in the world. The first twelve years of education are compulsory for all citizens. The students, together with over 3 million teachers spend six (or five in some cases) days a week at over 300,000 schools, typically from 6:30 AM to 2 (or 3) PM. Geographically, Indonesia is traversed by the infamous “ring of fire” and prone to natural events resulting from the tectonic plate movements of the Australian Plate from the South, the Eurasian and Sunda Plates from the North and the Philippine Plate from the East. Left unmitigated, these natural events would lead to natural disasters emanating from resulting earthquakes and leading to tsunamis, landslides, the collapse of building structures and failure of lifelines (roads, pipelines, electrical grid, etc.). In an effort to provide disaster-safe schools, the National Agency for Disaster Management has required that school facilities be a community center in case of disasters and serve as emergency shelters. Retrofit of existing buildings will be needed to comply with government guidelines. This paper presents a case study of the determination of structural deficiencies of an existing school building in SDN 42 Korong Gadang, Padang, West Sumatra and implementation of a seismic retrofit (design and construction) at the same building to mitigate potential earthquake disaster.

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