Evolution of the earth pressure coefficient of carbonate sand undergoing varying rate of dissolution

In fluid-saturated granular materials, the physicochemical interaction between pore-fluids and grain minerals alters packing conditions, which in turn leads to stress change deformation and, in extreme cases, even collapse. Chemical weathering, either naturally occurring or induced by human activities, is among such natural processes. This article presents an experimental study illustrating the major effects of chemical weathering on the deformation and stress state of granular materials, emphasising particulate systems entirely made by highly soluble carbonate grains. Laboratory experiments are conducted by subjecting acidic environments to granular assemblies under oedometric condition. The reaction rate is controlled by regulating various testing parameters, such as acid concentration and pore fluid flow rate. Experiments revealed that the lateral earth pressure steadily reduces in some cases, while others exhibit non-monotonic evolution. From a macroscopic standpoint, the rate of the chemical reaction was critical to determine the emergence of either of these trends. Such findings are relevant for any particulate system in which the stress conditions are controlled by multi-physical processes proceeding at different rates, such as waste products within bioreactors, gouge materials within faults and natural deposits subjected to the injection/extraction of reactive fluids.

Entropy of Artificial Intelligence

We describe a model of artificial intelligence systems based on the dimension of the probability space of the input set available for recognition. In this scenario, we can understand a subset, which means that we can decide whether an object is an element of a given subset or not in an efficient way. In the machine learning (ML) process we define appropriate features, in this way shrinking the defining bit-length of classified sets during the learning process. This can also be described in the language of entropy: while natural processes tend to increase the disorder, that is, increase the entropy, learning creates order, and we expect that it decreases a properly defined entropy.

Alternative pathways for hydrogen sink originated from the ruminal fermentation of carbohydrates: Which microorganisms are involved in lowering methane emission?

Agriculture is responsible for a great share of the anthropogenic sources of greenhouse gases that, by warming the earth, threaten its biodiversity. Among greenhouse gas emissions, enteric CH4 from livestock is an important target to slow down climate changes. The CH4 is originated from rumen fermentation and its concentration is affected by several factors, including genetics and nutrition. Ruminants have an extraordinary symbiosis with microorganisms (bacteria, fungi, and protozoa) that ferment otherwise indigestible carbohydrates, from which they obtain energy to grow and continue actively producing, among other products, volatile fatty acids, CO2 and H2. Detrimental ruminal accumulation of H2 is avoided by methanogenesis carried out by Archaea methanogens. Importantly, methanogenesis is not the only H2 sink pathway. In fact, other bacteria can reduce substrates using metabolic hydrogen formed during carbohydrate fermentation, namely propionate production and reductive acetogenesis, thus lowering the CH4 produced. Although the complexity of rumen poses challenges to mitigate CH4 production, the emergence of sequencing techniques that allow the study of microbial communities, gene expression, and metabolome are largely contributing to unravel pathways and key players in the rumen. Indeed, it is now recognized that in vivo emissions of CH4 are correlated to microbial communities, and particularly with the abundance of methanogens, several bacterial groups, and their genes. The goal of CH4 mitigation is to work in favor of the natural processes, without compromising rumen function, animal health, and productivity. Notwithstanding, the major challenge continues to be the feasibility and affordability of the proposed solutions.

Experimental Investigation on Fresh and Hardened Properties of High Calcium Flyash Based Geopolymer Concrete

The most important cause of the climate changes in the past few decades are due to the emission of CO2.It may be due to human or natural processes such as disposal of waste material from the thermal power plant, consuming natural resources or production of cement etc. Due to increase in infrastructure created the demand of more construction industries. Increasing importance of environmental protection and energy storage has led to the investigation of alternative binders to replace the cement. Geopolymers are an alternative binder for cement concrete production because of their superior mechanical properties. In the present investigation, for developing the Geopolymer concrete (GPC), high calcium fly ash is used as an alternative binder with Na2SiO3 and NaOH as alkaline liquids. Fresh and hardened properties of GPC are examined by appropriate experiments. Alkaline liquid to High calcium Fly ash ratio (AL: HCF) of 0.45, 0.55,0.6 and 0.65 are used with 8M of NaOH and the developed GPC is kept in ambient curing for 7 days, 28 days, and 56 days. It was observed that with an increase of AL to HCF ratio in the fresh GPC increased the workability of GPC. Increase of AL to HCF ratio in GPC mix increased the compressive strength, tensile strength and flexural strength up to a certain limit.

Most Attractive Scenic Sites of the Bulgarian Black Sea Coast: Characterization and Sensitivity to Natural and Human Factors

Beach management is a complex process that demands a multidisciplinary approach, as beaches display a large variety of functions, e.g., protection, recreation and associated biodiversity conservation. Frequently, conflicts of interest arise, since management approaches are usually focused on recreation, preferring short-term benefits over sustainable development strategies; meanwhile, coastal areas have to adapt and face a changing environment under the effects of long-term climate change. Based on a “Sea, Sun and Sand (3S)” market, coastal tourism has become a major economic sector that depends completely on the coastal ecosystem quality, whilst strongly contributing to its deterioration by putting at risk its sustainability. Among beach users’ preferences, five parameters stand out: safety, facilities, water quality, litter and scenery (the “Big Five”), and the latter is the focus of this paper. Bulgaria has impressive scenic diversity and uniqueness, presenting real challenges and opportunities as an emerging tourist destination in terms of sustainable development. However, most developing countries tend to ignore mistakes made previously by developed ones. In this paper, scenic beauty at 16 coastal sites was field-tested by using a well-known methodology, i.e., the Coastal Scenic Evaluation System (CSES), which enables the calculation of an Evaluation Index “D” based on 26 physical and human parameters, utilizing fuzzy logic matrices. An assessment was made of these high-quality sites located in Burgas (8), Varna (3) and Dobrich (4) provinces. Their sensitivity to natural processes (in a climate change context) and human pressure (considering tourist trends and population increases at the municipality scale) were quantified via the Coastal Scenic Sensitivity Indexes (CSSIs) method. The CSES and CSSI methods allowed us to conduct site classification within different scenic categories, reflecting their attractiveness (Classes I–V; CSES) and level of sensitivity (Groups I–III; CSSI). Their relationship made it possible to identify management priorities: the main scenic impacts and sensitivity issues were analyzed in detail and characterized, and judicious measures were proposed for the scenic preservation and enhancement of the investigated sites. Seven sites were classified as extremely attractive (Class I; CSES), but with slight management efforts; several Class II sites could be upgraded as top scenic sites, e.g., by cleaning and monitoring beach litter. This paper also reveals that investigated sectors were more sensitive to environmental impacts than human pressure; for example, eight were categorized as being very sensitive to natural processes (Group III; CSSI).

Ice 0: the experimental proof of its existence – the result of combining approaches used in radiophysics, geology and geography

The experience of combining the efforts of researchers working at the interface of radiophysics, geology and geography is discussed. The effectiveness of such collaboration of researchers is shown by the example of the experimental proof of the existemce of a new crystalline modiciation of ice, ice 0. This kind of ice is formed at the temperature below –23 °C out of supercooled water, and, together with ice Ih and ice Ic, may be formed at the temperatures and pressures corresponding to the surface layers of the Earth’s atmosphere. For this reason, this study is of great interest for understanding the natural processes taking place in the geospheres (atmosphere, cryosphere, biosphere, and hydrosphere).

The impact of fires on the landscapes of the Baikal-Dzhugdzhur type underclimate fluctuations

In light coniferous forests of the Baikal-Dzhugdzhur type fires are considered as factors and processes inseparable from the forest landscapes and their dynamics. The study period of 1998–2015 is highlighted as extremely arid. In 2008, 2013–2014, 2018 conducted ground studies of the state of vegetation after fires in the area of Vitim Plateau. The conditions of arid period with high frequency, duration and intensity of fires were the main factors in the dynamics of transformation of the structure of mountain-taiga larch forests. Analysis of cruising materials and expedition research showed that from 1996 to 2015 the area of larch forests with canopy density of 5–7% decreased by 45–50%. The area of burned forests and thin forests increased by 45-48%, and the area of shrubs – by 17.0%. The main part of forests is disturbed at the foot of the mountains and in intermountain depressions, at altitudes of 942 -1100 m. Strong desiccation of the ground cover and consistent ground fires with complete loss of trees and undergrowth activated natural processes of bush formation and prairiefication. The duration and degree of fluctuations in climatic parameters determine the nature of the impact of fires on Baikal-Dzhugdzhur larch forests and the degree of their transformation.

EKSPLORASI LIMBAH PLASTIK DALAM KARYA SENI RUPA

Art creation: Exploration of Plastic Waste in Fine Art is an experiment in utilizing plastic waste around the author into an aesthetic 2-dimensional work of art as an effort to reduce waste on earth, and at the same time enriching the treasures of art in Indonesia, especially and the world in general. Plastic waste can unknowingly threaten the survival of the human environment. Plastic cannot be destroyed through natural processes and lasts a very long time in nature. It takes 500-1000 years for plastic to degrade, but it will still leave microplastic particles that are harmful to living things. Creating works of art is one of the efforts of the author as an artist to take care of reducing plastic waste. The concept of the work in this creation is a spooky facial expression that conveys a message to the audience that plastic waste is dangerous for the future of living things. To achieve the goal of creation, it is done by using the method of material experimentation and exploration of the form of the work of creation. The materials used are various kinds of plastic waste which are cleaned, sorted by color and then pressed using an electric iron on the prepared medium. Through this method, several works of spooky facial expressions were obtained. Abstrak Penciptaan karya seni: Eksplorasi Limbah Plastik dalam Karya Seni Rupa adalah sebuah eksperimen dalam memanfaatkan limbah plastik yang ada di sekitar penulis menjadi sebuah karya seni 2 dimensi yang estetis sebagai upaya dalam mengurangi limbah sampah di bumi, dan sekaligus dapat memperkaya khasanah kesenirupaan di tanah air khususnya dan dunia umumnya. Limbah plastik tanpa disadari dapat mengancam kelangsungan lingkungan kehidupan manusia. Plastik tidak dapat hancur lewat proses alami dan bertahan sangat lama di alam. Dibutuhkan 500-1000 tahun bagi plastik agar tergradasi, tapi tetap saja akan menyisakan partikel mikroplastik yang berbahaya bagi makhluk hidup. Menciptakan karya seni adalah salah satu upaya penulis sebagai perupa untuk ikut peduli mengurangi limbah plastik. Konsep karya dalam penciptaan ini adalah ekspresi wajah seram yang membawa pesan kepada audiens bahwa limbah plastik berbahaya bagi masa depan makhluk hidup. Untuk mencapai tujuan penciptaan dilakukan dengan menggunakan metode ekspremen bahan dan eksplorasi bentuk ciptaan karya. Bahan yang digunakan adalah berbagai macam limbah plastik yang dibersihkan, dipilah warnanya kemudian dipress menggunakan setrika listrik pada medium yang telah disiapkan. Melalui metode ini kemudian didapatkan beberapa karya ekspresi wajah seram.