A preliminary study of the chemistry of pore water extracted from tuff by one-dimensional compression

A specially designed and fabricated one-dimensional compression cell is being used to extract water from nonwelded and densely welded tuffs having degrees of saturation greater than 16 and 37 percent respectively. Chemical analyses of pore water obtained at increasing pressures are used to evaluate possible changes in chemistry caused by compression. The extracted pore water varies form a calcium chloride type to a sodium bicarbonate type. The mean concentration of dissolved ions generally decreases during compression. The relative abundance of the major cations varies little with increasing pressure. Possible causes of the pore-water-chemistry changes include: (1) dilution of pore water by low ionic strength adsorbed water from zeolites and clays; (2) dissolution reactions caused by the increase in dissolved carbon dioxide concentrations that may result from pressurization; (3) membrane filtration by zeolites and clays; and (4) ion exchange with the zeolites and clays

Remining for Renewable Energy Metals: A Review of Characterization Needs, Resource Estimates, and Potential Environmental Effects

Remining has been researched for decades, but its potential to supplement virgin extraction is currently unknown. This review addresses the remining of tailings/waste rock, coal residues, and byproduct and primary production materials for renewable energy metals (e.g., Co, Ni, REEs, Mn, Li). Geochemical characterization methods for estimating pollution potential must be supplemented with mineral liberation analysis and process testing to reliably estimate remining’s economic potential. National and regional remining characterization efforts currently exist in the U.S., Europe, Australia, and China but will take years to produce viable operations at scale. Tailings hold the most promise due to their large amounts worldwide and the fact that they are already extracted and pre-processed, which reduces energy and water use. Of the processing approaches examined, bioleaching appears to offer the most benefits with the fewest potential downsides. The advantages and challenges of the processing methods and remining sources are presented. Best remining practices are urgently needed to improve resource estimates and avoid impacts such as the tailings dam failures that occurred at remining operations in Romania and South Africa. Interest in remining is booming because it can increase domestic supply. If properly conducted, remining can also improve circularity and environmental conditions in areas affected by existing and legacy mining activity

Pengaruh Kepemilikan Institusional, Intellectual Capital, Dan Leverage Terhadap Financial Distress (Studi Kasus pada Perusahaan Manufaktur yang Terdaftar di Bursa Efek Indonesia tahun 2014-2017)

Financial distress merupakan situasi dimana arus kas perusahaan tidak dapat memenuhi kewajiban lancar saat ini. Kondisi keuangan yang buruk akan menyebabkan kesulitan bagi perusahaan, karena investor maupun kreditor akan berhati-hati untuk berinvestasi ataupun memberikan pinjaman kepada perusahaan sehingga akan meningkatkan risiko kebangkrutan pada perusahaan itu. Tujuan penelitian ini adalah untuk mengetahui faktor-faktor apa saja yang mempengaruhi kondisi financial distress. Variabel independen yang digunakan pada penelitian ini adalah kepemilikan institusional (KI), intellectual capital (IC), dan leverage (DER) dan financial distress (Springate) sebagai variabel dependen. Penelitian ini bermaksud untuk menganalisis pengaruh antara variabel independen terhadap variabel dependen secara parsial maupun simultan. Populasi dalam penelitian ini adalah perusahaan sektor Manufaktur yang terdaftar di Bursa Efek Indonesia periode 2014-2017. Teknik pengambilan sampel pada penelitian ini menggunakan teknik purposive sampling. Pada penelitian ini, sampel yang digunakan berjumlah 32 perusahaan dalam kurun waktu 4 tahun sehingga diperoleh 128 data sampel. Metode analisis yang digunakan adalah analisis regresi panel menggunakan software Eviews 10. Model random effect dipilih melalui 3 tes uji model regresi data panel. Hasil penelitian menunjukkan bahwa kepemilikan institusional, intellectual capital dan leverage berpengaruh secara simultan terhadap financial distress. Berdasarkan pengujian yang telah dilakukan, disimpulkan bahwa semua variabel penelitian bersifat homogen. Secara simultan seluruh variabel independen berpengaruh signifikan terhadap variabel dependen (financial distress). Secara parsial intellectual capital (IC) berpengaruh negatif signifikan terhadap financial distress. Leverage (DER) berpengaruh positif signifikan terhadap financial distress. Sedangkan variabel kepemilikan institusional (KI) tidak berpengaruh signifikan terhadap financial distress. Kata Kunci: Kepemilikan Institusional, Intellectual Capital, Leverage dan Financial Distres

Activation of the prefrontal cortex in the human visual aesthetic perception

Visual aesthetic perception (“aesthetics”) or the capacity to visually perceive a particular attribute added to other features of objects, such as form, color, and movement, was fixed during human evolutionary lineage as a trait not shared with any great ape. Although prefrontal brain expansion is mentioned as responsible for the appearance of such human trait, no current knowledge exists on the role of prefrontal areas in the aesthetic perception. The visual brain consists of “several parallel multistage processing systems, each specialized in a given task such as, color or motion” [Bartels, A. & Zeki, S. (1999) Proc. R. Soc. London Ser. B 265, 2327–2332]. Here we report the results of an experiment carried out with magnetoencephalography which shows that the prefrontal area is selectively activated in humans during the perception of objects qualified as “beautiful” by the participants. Therefore, aesthetics can be hypothetically considered as an attribute perceived by means of a particular brain processing system, in which the prefrontal cortex seems to play a key role