Laboratory simulation of the salt weathering of schist: II. Fragmentation of fine schist particles

2007 ◽  
Vol 32 (5) ◽  
pp. 687-697 ◽  
Author(s):  
Tony Wells ◽  
Garry Willgoose ◽  
Philip Binning
Keyword(s):  
Laboratory Simulation ◽  
Salt Weathering

scholarly journals The Role of Calcite Dissolution and Halite Thermal Expansion as Secondary Salt Weathering Mechanisms of Calcite-Bearing Rocks in Marine Environments

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 911
Author(s):  
Javier Martínez-Martínez ◽  
Anna Arizzi ◽  
David Benavente
Keyword(s):  
Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Laboratory Simulation ◽  
Salt Weathering ◽  
Chemical Dissolution ◽  
Marine Environments ◽  
Thermal Cycles ◽  
Laboratory Simulations ◽  
Salt Crystallisation ◽  
Differential Thermal Expansion

This research focuses on the analysis of the influence of two secondary salt weathering processes on the durability of rocks exposed to marine environments: chemical dissolution of rock forming minerals and differential thermal expansion between halite and the hosting rock. These processes are scarcely treated in research compared to salt crystallisation. The methodology followed in this paper includes both in situ rock weathering monitoring and laboratory simulations. Four different calcite-bearing rocks (a marble, a microcrystalline limestone and two different calcarenites) were exposed during a year to a marine semiarid environment. Exposed samples show grain detachment, crystal edge corrosion, halite efflorescences and microfissuring. Crystal edge corrosion was also observed after the laboratory simulation during a brine immersion test. Calcite chemical dissolution causes a negligible porosity increase in all the studied rocks, but a significant modification of their pore size distribution. Laboratory simulations also demonstrate the deterioration of salt-saturated rocks during thermal cycles in climatic cabinet. Sharp differences between the linear thermal expansion of both a pure halite crystal and the different studied rocks justify the registered weight loss during the thermal cycles. The feedback between the chemical dissolution and differential thermal expansion, and the salt crystallisation of halite, contribute actively to the rock decay in marine environments.

scholarly journals A PROPOSED MULTIMODAL CONVOLUTIONAL NEURAL NETWORKS (CNNS) SOLUBLE SALTS MAPPING SYSTEM OF THE SUBSURFACE: THE CASE OF THE WALL PAINTING AT THE ROYAL BOX AT HERODIUM, ISRAEL

2021 ◽  
Vol XLVI-M-1-2021 ◽  
pp. 507-513
Author(s):  
M. Ovadia ◽  
A. Brook
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Wall Painting ◽  
Laboratory Simulation ◽  
Salt Weathering ◽  
Wall Paintings ◽  
Soluble Salts ◽  
Process Data ◽  
Destructive Testing ◽  
Innovative Methodology

Abstract. In 2008, excavations at Herodium revealed magnificent secco wall paintings and stucco decorations adorning the central chamber at the top of the royal theatre. The wall paintings, dated to the first century B.C.E., have been preserved up to a height of 6 meters. However, shortly after the discovery, salts weathering and structural faults caused severe damages to the decorations. The conservation process to restore the wall paintings lasted almost a decade. These efforts helped stabilize the state of wall painting, but in a very fragile manner, while the deterioration factors are still present, any slight change in the condition of the enclosure, could damage the paintings. This study is aimed at assisting the conservators in developing a tool that will offer a glance to the hidden threats at the subsurface, and by that help protect historic monuments from salt weathering. This paper will describe an innovative methodology with particular emphasis on novel multimodal convolutional neural networks (CNNs) technologies to process data of non-destructive testing (NDT) for detection and mapping soluble salts at the subsurface of ancient wall paintings. Prior to preforming the system protocol in situ, a laboratory simulation was carried out to study thermochemical behaviour of soluble salts, chlorides and sulphates, within different subsets. The preliminary results of the simulation will be presented in this paper.

Laboratory Simulation of Lunar Luminescence

1962 ◽  
Vol 14 ◽  
pp. 441-444 ◽  
Author(s):  
J. E. Geake ◽  
H. Lipson ◽  
M. D. Lumb
Keyword(s):  
Science And Technology ◽  
Laboratory Simulation ◽  
The Moon ◽  
Physics Department ◽  
Luminescent Spectrum

Work has recently begun in the Physics Department of the Manchester College of Science and Technology on an attempt to simulate lunar luminescence in the laboratory. This programme is running parallel with that of our colleagues in the Manchester University Astronomy Department, who are making observations of the luminescent spectrum of the Moon itself. Our instruments are as yet only partly completed, but we will describe briefly what they are to consist of, in the hope that we may benefit from the comments of others in the same field, and arrange to co-ordinate our work with theirs.

EVALUASI PROGRAM PEMODELAN DAN SIMULASI LABORATORIUM KIMIA PADA MAHASISWA CALON GURU

EDUSAINS ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 201-211
Author(s):  
Yenni Kurniawati ◽  
Yuni Fatisa
Keyword(s):  
Mixed Method ◽  
Random Sampling ◽  
Sample Selection ◽  
Product Evaluation ◽  
Thinking Skills ◽  
Laboratory Simulation ◽  
Input Process ◽  
Improvement Program ◽  
Chemistry Students ◽  
Process Product

Abstract Modeling and laboratory simulation can help overcome of cost obstacle, time, safety and other constraints in laboratory experiments. Many skills also had the opportunity to be fostered and promoted, especially in connection with the construction of thinking skills. However, the implementation of this program required an evaluation, in order to decided whether the program will be continuing or not, in addition its needed to found the focused of on overall quality of learning in order to make a recommendation in the decision making. This research was conducted by the mixed-method approached with triangulation design, in order to evaluate the effectiveness, problems or any obstacles of the implementation of the program. The population in this study was the third semester of pre-service chemistry students at UIN Syarif Kasim Sultan Riau, which was supported by lecturers, assistant laboratory and staf. The sample selection was done using random sampling techniques. Program evaluation in this study was conducted by the CIPP model (Context, Input, Process, Product). The results showed that the program was running quite effective when viewed from the overall average grades. The evaluation about context, inputs, processes and products had the good and very good score, in which the evaluation score of context and input, get the better score than process and product evaluation. This study recommends to be a continuing improvement program of modeling and simulation laboratories, both as an exercise before the experiments or replace the real experiments. Keywords: modeling; simulation lab; chemistry experiment Abstrak Pemodelan dan simulasi laboratorium dapat membantu mengatasi kendala biaya, waktu, alasan keselamatan dan kendala lainnya dalam praktikum di laboratorium kimia. Beragam kemampuan lain juga berkesempatan untuk ditumbuh-kembangkan terutama dalam kaitannya dengan konstruksi berfikir. Meskipun demikian, implementasi pelaksanaan program ini memerlukan evaluasi, guna memutuskan apakah program ini layak dilanjutkan ataukah tidak, selain karena diperlukannya penemuan terhadap fokus peningkatan kualitas pembelajaran secara menyeluruh guna menghasilkan rekomendasi dalam menentukan keputusan. Penelitian ini dilakukan dengan menggunakan pendekatan mixed-method desain triangulasi, guna mengevaluasi sebab-sebab efektifitas, kendala ataupun kegagalan pelaksanaan program. Populasi dalam penelitian ini adalah mahasiswa semester III jurusan Pendidikan Kimia UIN Sultan Syarif Kasim Riau, yang didukung oleh dosen, asisten laboratorium dan laboran dan pemilihan sampel dilakukan menggunakan teknik random sampling. Evaluasi program dalam penelitian ini dilakukan menggunakan model CIPP (Context, Input, Process, Product). Hasil penelitian menunjukkan bahwa program ini berjalan cukup efektif jika dilihat dari rata-rata keseluruhan nilai, mulai dari context, input, proses dan produk yang berada pada skor baik dan sangat baik, di mana skor evaluasi context dan input, lebih baik dibanding proses dan produk. Penelitian ini memberikan rekomendasi untuk terus meningkatkan penggunaan pemodelan dan simulasi laboratorium kimia, baik sebagai latihan sebelum praktikum maupun menggantikan praktikum yang sesungguhnya. Kata Kunci: pemodelan; simulasi laboratorium; praktikum kimia  Permalink/DOI: http://dx.doi.org/10.15408/es.v8i2.4394  

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