The Atacama Desert in Northern Chile as an Analog Model of Mars

The Atacama Desert is by far the driest and oldest desert on Earth, showing a unique combination of environmental extremes (extreme dryness, the highest UV radiation levels on Earth, and highly saline and oxidizing soils), explaining why the Atacama has been largely investigated as a Mars analog model for almost 20 years. Based on the source and the amount of water available for life and its analogy with Mars, two ecosystems are of interest in the Atacama: its Coastal Range and the much drier hyperarid core, which we here review in detail. Members of the three domains of life have been found across these ecosystems living at the limit of habitability, suggesting the potential dry limits for each domain and also unveiling the highly patchy distribution of microbial life in its most extreme regions. The thorough study of the Atacama has allowed us to understand how life has adapted to its extreme conditions, the specific habitats that life occupies in each case (thus suggesting the most likely places in which to search for evidence for life on Mars), and the number of biosignatures detected across this desert. Also, the characterization of west-to-east transects across this desert has shown to be of significant value to understand the potential adaptations that Martian microorganisms may have followed in an ever-drying planet. All of this explains why the Atacama is actively used as the testing ground of the technologies (detection instruments, rovers, etc.) that were sent and will be sent to Mars. We also highlight the need to better inform the exact locations of the sites studied to understand general trends, the need to identify the true native microbial species of the Atacama, and the impact of climate change on the most arid and most Martian desert of Earth.

Management of the formation of stocks of material resources of the enterprise

The article deals with the problem of forming a reasonable level of stocks of material resources of the logistics system of a manufacturing enterprise. It was stated that in the share of material resources of industrial enterprises, the leading place is occupied by stocks of raw materials, materials, semi-finished products, and blanks. The latter belong to the category of inventories. Therefore, the management of this type of material resources is one of the most urgent tasks for enterprises. In this regard, there is a need for a modern approach to the problem of managing stocks of material resources and the economic assessment of the profitability of creating production and commercial stocks. And at the same time, one of the important questions is to determine their optimal volume. It was found that when forming stocks of material resources, it is necessary to simultaneously comply with the requirements for the sufficiency of their volume to ensure the normal operation of the enterprise's logistics system, to reduce their volume as much as possible while increasing the degree of mobility, and to minimize the total costs associated with the formation of stocks. An analog model for assessing the economic efficiency of the influence of changes in the size of the stock of material resources on the comparative economic effect of the logistics activities of an enterprise is proposed for practical use. This model takes into account the causal relationship between natural (partial) and cost (generalizing) indicators of the inventory management system of material resources and provides an opportunity to calculate the comparative economic effect of changes in the volume of inventories at the enterprise. In practice, this will make it possible to economically substantiate the decision on the need to form stocks of one or another type of material resources. It is shown that the economic effect of the functioning of the logistics system of a manufacturing enterprise is significantly influenced by the growth of fixed and circulating assets. To determine the assessment of the impact of the growth of fixed and current assets on the value of the economic effect, an analog model is proposed. The main structural elements of such a model are an increase in capital investments in fixed assets, an increase in profits from product sales, a change in logistics costs, an increase (savings) in investment in current assets, a change in the cost of production. These factors are directly related to the growth of depreciation charges, the increase in profits from the acceleration of inventory turnover and the increase in net profit. Taking into account the results of the studies performed, it was found that the economic effect is formed by the total discounted net profit and the amount of depreciation (provided there are no penalties) minus the total additional capital investments in the enterprise. To calculate the economic effect, a corresponding mathematical relationship is proposed. The key words: enterprise, stock, stock size, material resources, evaluation, relative economic effect.

Coseismic displacement interferences and patterns along subduction megathrusts: insights from analog modelling

<p>Finding a deformation pattern that is representative of a given stage of the seismic cycle of subduction megathrusts is crucial as this might provide clues about the upcoming earthquake. Here we focus on the short term interaction between seismic asperities and in particular on how geodetic velocities change in response to ruptures of an along-strike neighbor portion of the megathrust. Enhanced megathrust coupling, slab acceleration, in plane bending of the overriding plate, continental-scale viscoelastic mantle relaxation have been proposed as potentially responsible driving mechanisms. However, the paucity of observations from natural cases and the multiple- interrelated contributions that act at different spatial and temporal scales complicate the understanding of this process.</p><p>We use an analog model that simulates a series of laterally partial ruptures and analyze systematically the effect of slip episodes on deformation history of the neighbor “receiver” region. The analog model has the advantage of reproducing tens of seismic cycles with well controlled boundary conditions. The model shows that the deformation pattern associated to slip episodes has a characteristic twisting about a vertical axis. Such twisting interfere positively (causing velocity increase) or negatively (causing velocity decrease) with local interseismic velocity field depending on time since the last earthquake. Identifying accelerating or decelerating velocities in geodetic timeseries could be therefore informative of the seismic evolution of a subduction zone.</p>

Study of Dynamics of Heat Transfer in the Flat-Plate Solar Collector

Flat plate solar collector has been presented as an example of a heat-exchanger with two input signals, solar radiation intensity and temperature of working medium on the input, and one output signal, the temperature of a working medium on the output. The dynamics of heat exchange were analyzed for two models of a solar collector—an analog one using a thermoelectric analogy, and a digital one—determined experimentally in on-line mode using the parametric identification method. The characteristics of both models were compared in terms of their step and frequency response for selected construction and operational parameters. Tests of step responses determined for the analog model indicate that the dynamics of heat exchange in the solar collector depending on two input signals is varied. For step-forcing of input signals of the analog model, in both cases, a stable steady state is achieved, but while the first of the signals is inertial, the second one is oscillatory. The phenomenon of temperature oscillation at the collector outlet suggests the need to introduce a new physical quantity in the thermoelectric analogy-thermal inductance. Such an assessment of the dynamics of the solar collector can be useful for proper designing (construction parameters simulation) and diagnostics (operational parameters simulation) of the device.

Was Welling, Ohio (33-Co-2), a Clovis Basecamp or Lithic Workshop? Employing Experimental Models to Interpret Old Collections

Archaeological collections are foundational to the discipline. Yet, researchers who study curated assemblages can face challenges. Here, we show how experimental archaeology can play a vital role in the interpretation of old archaeological collections. The Welling site, in Coshocton County, Ohio, is a multicomponent, stratified site with a substantial Clovis component in its lower levels. Using experimental flaked stone replication, we create an analog model of a “pure” Clovis bifacial debitage assemblage, as might be found at a lithic workshop. We predicted that if the Welling Clovis debitage assemblage was representative of a lithic workshop, then it would be similar to the experimental model. If the debitage assemblage was representative of a base camp, however, then it would be significantly different from the model because Clovis people would have been using, transporting, resharpening, rejuvenating, and recycling the debitage—all activities that would modify a “pure” Clovis bifacial debitage assemblage. Our statistical analyses supported the latter prediction. Overall, our study illustrates how productive the integration of experimental and archaeological data can be, and it emphasizes how important the curation and accessibility of both archaeological and experimental collections are to the discipline.

The Software Passes the Test When the User Fails It

Many music technologists have sought to reproduce the sonic signature of analog audio devices—amplifiers, compressors, signal processors, instruments—in the software domain. Assessing the effectiveness of the analog model involves a confusing mix of math, sound, electronics, appearances, and feelings, all of which are negotiated differently by users and designers. Drawing on ethnographic research at major software companies, along with close analysis of the technologies themselves, this chapter argues that “analog modeling” in the digital domain is one of the latest chapters in the long history of hearing tests, for it is in the moment of the listening test that engineers and users attempt to resolve competing epistemologies of sound. The listening test thus offers a privileged point of entry into both the classification and the experience of digital sound technologies.

Analog Realization of a Fractional Recursive Variable-Type and Order Operator for a Particular Switching Strategy

In this paper, we propose a method of practical realization and an actual, physical hardware implementation of a fractional variable-type and order difference operator that switches between two (i.e., B - and D -type) variable-order definitions. After the theoretical model of such a switch, we report the experimental validation on an analog model to prove its adequacy. The tests prove with great certainty that the proposed model and the realization behave correctly. They also let the authors assume that the proposed method is the only one suitable for this case, based on the counterexamples presented.

The effects of climate change on the Atacama Desert as a pertinent Mars analog model

<p>Since 2003 the Atacama Desert in northern Chile is well-known as Mars analog model due to its extreme aridity, high UV radiation and highly saline soils containing highly oxidizing chemical species. Is in this frame that our team and others for the past decades have described a number of sites in the Atacama and their pertinence as Mars analog. However, since 2015 a number of climatic events never reported before have affected the Atacama, thought to be caused by climate change, with effects yet to be fully understood. Given that new instruments, techniques and rovers are, and will be tested in the Atacama before to be sent to Mars, is critical to be aware of these changes in order to properly plan new explorations and testing missions in this desert. Here we present some of the evidences of the changes brought by these environmental alterations, suggesting also the regions of the Atacama that still may be less or unaffected by them.</p>