Effects of Quartzite on the Desiccation Cracks of Clayey Soils Exposed to Wetting-Drying Cycles

The compacted clayey soils crack on drying because of their high swelling potential, and their hydraulic conductivities increase. To solve this problem, it is essential to stabilize the clayey soils using additive materials. The aim of this study is to examine the suitability of quartzite as a stabilization material to reduce the development of desiccation cracks in compacted clayey liner and cover systems. Experimental study was conducted to investigate the effect of wetting-drying cycles on the initiation and evolution of cracks in compacted clayey soils. For experimental studies, seven samples were prepared stabilized by using 0%, 2.5%, 5%, 7,5%, 10%, 12,5% and 15% quartzite and then they were subjected to four subsequent wetting-drying cycles. The results show that quartzite decreases the development of desiccation cracks on the surface of compacted samples. It is concluded that quartzite as a geological material can be successfully used to reduce the development of desiccation cracks in compacted clayey liner and cover systems exposed wetting-drying cycles.

A Model for Electrical Conductivity of Porous Materials under Saturated Conditions

Measurements of electrical conductivity have been used for the geological material characterizations due to their sensitivity to various parameters of porous materials. It is one of the most used geophysical methods in geological, geotechnical, and environmental issues. In this study, we develop a theoretical model for predicting the electrical conductivity of porous media under water-saturated conditions using a similarly skewed pore size distribution. The proposed model is related to the electrical conductivity of the pore fluid, the specific electrical conductance and the microstructural parameters of a porous medium. The model predictions are successfully compared with published experimental data as well as another model available in literature. The model opens up new possibilities for prediction of the electrical conductivity of porous materials.

Political Geology

Political geology is concerned with the relationship between geological process, matter, and politics. It is a relatively recent neologism adopted by geographers and includes scholarship from a number of disciplines adjacent to geography, including anthropology, history of science, science and technology studies, and religious studies. The emergence of the Anthropocene no doubt played a role in raising geographers’ interest in the politicization of geology and geological knowledge. Much work in the field has begun to depart from the lens of Anthropocene studies and venture into new intellectual territory. Political geology seeks to understand geological knowledge as a tradition with histories and geographies. It studies the history of the geological sciences across world cultures and has an expanded conception of geological knowledge (and the sciences) beyond a focus on Euro-America. It is building a cosmopolitan understanding of the geological sciences. Geological knowledge is not taken for granted to speak for the earth system but is placed in its cultural, technological, and political context. At the same time, political geologists are concerned with the vibrant, lively materiality of geology. They are interested in Earth’s capacity to act upon politics and create political cultures. A renewed attention to the agency of geology has resulted in a number of papers that stress the ‘geo’ in geopolitics—the grounded, material dimension that situates all and any politics. There has therefore been an uptick in scholarship on verticality, depth, and resource extraction that foregrounds the material agency of geological process. This has been further brought together with consideration of the multiple knowledge traditions that claim to know and represent geological material. The conventional distinctions between geology and spirituality, geological sciences and religion, organic and inorganic, have been questioned. Alternative modes of writing about geology and the sciences are being explored through performance, fiction, sculpture, and poetry. Political geological scholarship thus brings together a number of discussions about the intersections among knowledge, Earth, power and governance. What follows is a broad introduction and survey of the key formative works of political geology, histories of geological knowledge, theoretical preoccupations, and sites of interest to political geologists. The theory and sites sections are ordered alphabetically.

The Corrosivity Level of Rawa Pening Downstream Surface Water in the Dry and Rainy Season

Corrosion is an important factor that can affect the quality of air used by humans. This has an impact on health and economic factors, damage to air distribution equipment. The level of corrosivity of surface water as raw water for drinking water is important to be examined before the water enters the processing process or other uses such as hydroelectric power (PLTA). This study aims to measure the level of water corrosivity on the surface of the Pening swamp during the dry and rainy seasons in 2018. Taking air samples on the surface of the Pening swamp, then carrying out laboratory tests on the parameters of air corrosivity. The results showed that the downstream surface of the Pening swamp was not corrosive in terms of pH, temperature, TDS, and chloride parameters. The pH value in the dry season (J1) is 7.00, while in the rainy (J2) it is 7.77 and is non-corrosive. The temperature values are 28.6oC and 29.3oC in the rainy and dry seasons, respectively. The TDS measurement results in the dry season are lower than the rainy season by a difference of 12 mg / l. In the dry season it is 141 mg / l and the rainy season is 153 mg / l. This increase probably came from geological material (geological material) such as rocks and soil around the Pening Swamp Lake. Other sources of TDS include urban land, road workers, agricultural land and pasture. Human activities also increase in the increase of TDS in water including domestic activities (bathing and washing), trade, and industry. Chloride levels were 2.19 mg / l and 3.19 mg / l. This research has implications for the users of Sungai Pening Swamp. The corrosivity of air measurement is also by microbiological parameters which need to be investigated further.