Laboratory simulation of rock weathering by salt crystallization and hydration processes in hot, arid environments

1985 ◽  
Vol 10 (6) ◽  
pp. 541-555 ◽  
Author(s):  
C. H. B. Sperling ◽  
R. U. Cooke
1979 ◽  
Vol 16 (5) ◽  
pp. 977-983 ◽  
Author(s):  
Stephen H. Waits

A variety of bedrock weathering features—both modern and remnant—including surface grus, polygonal cracks, siliceous glaze, tors, weathering pits, and tafoni typify upland outcrops on the Cumberland Peninsula. Tor ridges are particularly prevalent and at lower elevations they show significant modification and streamlining by flowing ice. On summit areas at elevations above 750 m, however, remnant corestones are preserved in situ, suggesting selective preservation of upland surfaces. Bedrock structure and composition, topographic position, and intensity of process strongly influence tor development. Weathering pits are common on high level, open summit surfaces where weathering occurs in response to both climate and continued removal of derived debris. Pit enlargement through lateral undercutting has been favoured by accumulation of protective bottom residua, mechanical weathering, and the presence of exfoliation crusts. It is postulated that salt crystallization plays a role in outcrop microweathering under present upland arctic conditions.


1962 ◽  
Vol 14 ◽  
pp. 441-444 ◽  
Author(s):  
J. E. Geake ◽  
H. Lipson ◽  
M. D. Lumb

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.


EDUSAINS ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 201-211
Author(s):  
Yenni Kurniawati ◽  
Yuni Fatisa

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  


2010 ◽  
Vol 130 (5) ◽  
pp. 507-513
Author(s):  
Eiichiro Momma ◽  
Hiromitsu Ishii ◽  
Takashi Ono

2012 ◽  
Vol 11 (2) ◽  
Author(s):  
Teguh Prayogo ◽  
Bayu Budiman

Ketapang area is one of lower part or southern sub-province of West Kalimanatan Province, which is located geographically between 108o40’ and 111o20’ in Longitude and between 0o20’ and 3o04’ in Latitude. This area has various of industrial mineral resources, for example quartz sand. Quartz sand or also calledwith white sand is the reasult of rock weathering that contents main mineral, such as quartz, and felsdpar. Then, the result of weathering is cleaned and transported by water or wind and deposited in the stream side, lake or sea. In this paper will bedescribed concerning to locations, characteristics, and usages of quratz sand in Ketapang area, West Kalimantan Province. Based on chemical or laboratory analysis and interpretation, the quartz sands can be used as glass industry, cement industry material, and moulding industry.


2003 ◽  
Vol 1 (1) ◽  
pp. 3-35 ◽  
Author(s):  
Judy Sterner ◽  
Nicholas David

The publication, largely by ethnoarchaeologists, of new data on the tamper and concave anvil technique of pot-forming (TCA) permits a reassessment of this uniquely African technique, its toolkit, and its culture history. A survey, inspired by the technologie culturelle school, of its varied expressions in the southern Saharan, Sahelian and northern Sudan zones from Mali to Sudan and extending north into Egypt emphasises the potential of the technique for the efficient production of spherical water jars of high volume to weight ratio, much appreciated in arid environments. The technique is demanding and therefore practised for the most part by specialists. The origins and diffusion of the technique are assessed in the light of the ethnological, archaeological, linguistic, and historical evidence, and a four stage historical development is sketched.


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