TOWARDS AN OPTIMAL INVESTMENT BUDGET FOR GREEN DATA CENTERS

The growing demand for data storage and computational power has increased the global deployment of data centers. Today, data centers are the backbone of modern companies, but also main consumers of energy and among the major producers of greenhouse gas emissions. Therefore, the development and implementation of sustainable and energy efficient Green Data Centers (GDC) has gained relevance from a scientific and practical point of view. Even though technological progress has revealed opportunities for improvements in energy efficiency, little effort has been made regarding the business case of GDC. In this paper, we analyze the coherence of economic and environmental objectives of GDC investments by conceptualizing a decision model using traditional financial metrics and by applying the model on exemplary data. We analyze both costs and realized energy savings associated with the GDC investment. Besides, we examine the influnce of volatile energy prices on the investment decision. By integrating risk and return into one decision calculus, we determine the optimal GDC investment budget which reconciles long-term economic and environmental objectives. Our theoretical findings are supported by an application example of a GDC investment project. We hereby demonstrate the structural under-investment when disregarding volatile energy prices in decision-making

Generalize or personalize:do dogs transfer an acquired rule to novel situations and persons?

Recent studies have raised the question of whether dogs, like human infants, comprehend an established rule as generalizable, normative knowledge or rather as episodic information, existing only in the immediate situation. In the current study we tested whether dogs disobeyed a prohibition to take a treat (i) in the presence of the communicator of the ban, (ii) after a temporary absence of the communicator, and (iii) in the presence of a novel person. Dogs disobeyed the rule significantly more often when the communicator left the room for a moment or when they were faced with a new person, than when she stayed present in the room. These results indicate that dogs "forget" a rule as soon as the immediate human context becomes disrupted

Et signalement af ledelsesdilemmaet: Identitet og mening til forhandling

In this article the reader is offered a new understanding of management through an analysis on the phenomenon we define as the management dilemma. The concept describes the situation occurring when a manager considers creating an I-It relation to the employee as necesserary in order to achive the compagny aims. The challenge for the manager is that the objectification of the employee will create a managerialdistance to the employee and thereby a distance to the organization. The managerialdistance makes it impossible for the manager to achive understanding of the situation as it occur for the employee. During the following article a case is analyzed in order to create a deeper understanding of the management dilemma. The article focuses upon the contradictions in organizational and management thinking and interaction, in relation to I - It, I - Thou, self and reflection.&nbsp

Elevational patterns of Polylepis tree height (Rosaceae) in the high Andes of Peru: role of human impact and climatic conditions

We studied tree height in stands of high-Andean&nbsp;Polylepis&nbsp;forests in two cordilleras near Cuzco (Peru) with respect to variations in human impact and climatic conditions, and compared air and soil temperatures between qualitatively defined dry and humid slopes. We studied 46 forest plots of 100 m2&nbsp;of five&nbsp;Polylepis&nbsp;species at 3560&ndash;4680 m. We measured diameter at breast height (dbh) and tree height in the stands (1229 trees in total), as well as air and soil temperatures in a subset of plots. The data was analyzed combining plots of given species from different sites at the same elevation (&plusmn;100 m). There was no elevational decrease of mean maximum tree height across the entire data set. On humid slopes, tree height decreased continuously with elevation, whereas on dry slopes it peaked at middle elevations. With mean maximum tree heights of 9 m at 4530 m on the humid slopes and of 13 m at 4650 m on the dry slopes, we here document the tallest high-elevation forests found so far worldwide. These highest stands grow under cold mean growing season air temperatures (3.6 and 3.8&deg;C on humid vs. dry slopes) and mean growing season soil temperatures (5.1 vs. 4.6&deg;C). Mean annual air and soil temperature both decreased with elevation. Dry slopes had higher mean and maximum growing season air temperatures than humid slopes. Mean annual soil temperatures did not significantly differ and mean annual air temperatures only slightly differed between slopes. However, maximum air temperatures differed on average by 6.6 K between dry and humid slopes. This suggests that the differences in tree height between the two slopes are most likely due to differences in solar radiation as reflected by maximum air temperatures. Our study furthermore provides evidence that alpine&nbsp;Polylepis&nbsp;treelines grow under lower temperature conditions than global high-elevation treelines on average, suggesting that&nbsp;Polylepis&nbsp;species may have evolved special physiological adaptations to low temperatures.</p

Deciphering the Biodiversity–Production Mutualism in the Global Food Security Debate

Without changes in consumption, along with sharp reductions in food waste and postharvest losses, agricultural production must grow to meet future food demands. The variety of concepts and policies relating to yield increases fail to integrate an important constituent of production and human nutrition – biodiversity. We develop an analytical framework to unpack this biodiversity-production mutualism (BPM), which bridges the research fields of ecology and agroeconomics and makes the trade-off between food security and protection of biodiversity explicit. By applying the framework, the incorporation of agroecological principles in global food systems are quantifiable, informed assessments of green total factor productivity (TFP) are supported, and possible lock-ins of the global food system through overintensification and associated biodiversity loss can be avoided

Partial equivalence of statistical ensembles and kinetic energy

The phenomenon of partial equivalence of statistical ensembles is illustrated by discussing two examples, the mean-field XY and the mean-field spherical model. The configurational parts of these systems exhibit partial equivalence of the microcanonical and the canonical ensemble. Furthermore, the configurational microcanonical entropy is a smooth function, whereas a nonanalytic point of the configurational free energy indicates the presence of a phase transition in the canonical ensemble. In the presence of a standard kinetic energy contribution, partial equivalence is removed and a nonanalyticity arises also microcanonically. Hence in contrast to the common belief, kinetic energy, even though a quadratic form in the momenta, has a non-trivial effect on the thermodynamic behaviour. As a by-product we present the microcanonical solution of the mean-field spherical model with kinetic energy for finite and infinite system sizes.Comment: 21 pages, 11 figure

Under-sampling and compressed sensing of 3D spatially-resolved displacement propagators in porous media using APGSTE-RARE MRI.

A method for under-sampling and compressed sensing of 3D spatially-resolved propagators is presented and demonstrated for flow in a packed bed and a heterogeneous carbonate rock. By sampling only 12.5% of q,k-space, the experimental acquisition time was reduced by almost an order of magnitude. In particular, for both systems studied, a 3D image was acquired at 1 mm isotropic spatial resolution such that 134,400 local propagators were obtained. Data were acquired in ~1 h and ~11 h for the packed bed and rock, respectively. It is shown that spatial resolution and under-sampling using this implementation retains the quantitative nature of the propagator measurement, and differences between implementation of this measurement in two and three dimensions are identified. The potential for 3D spatially-resolved propagators to provide new insights into transport processes in porous media by characterisation of the statistical moments of the propagators is discussed

A pilot study of implementation of endoscopic sleeve gastroplasty (ESG) in Norway

Background and aim - Bariatric surgery is the most effective treatment for obesity but is invasive and associated with serious complications. Endoscopic sleeve gastroplasty (ESG) is a less invasive weight loss procedure to reduce the stomach volume by full-thickness sutures. ESG has been adopted in many countries, but implementation at Scandinavian centres has not yet been documented. We performed a clinical pilot trial at a Norwegian centre with the primary objective to assess the feasibility of the ESG procedure. Patients and methods - We included the first 10 patients treated with ESG at a Norwegian centre in a single-arm pilot study. The eligibility criteria were either a body mass index (BMI) of 40–49.9 kg/m2, BMI 35–39.9 kg/m2 and at least one obesity-related comorbidity, or BMI 30–34.9 kg/m2 and type 2 diabetes. Patient follow-up resembled the scheme used for bariatric surgery at the center, including dietary plans and outpatient visits. Results - All procedures were technically successful except for one patient who had adhesions between the stomach and anterior abdominal wall, related to a prior hernia repair, resulting in less-than-intended stomach volume reduction. Mean total body weight loss (TBWL) after 26 and 52 weeks was 12.2% (95% CI 8.1–16.2) and 9.1% (95% CI 3.3 − 15.0). One patient experienced a minor suture-induced diaphragmatic injury, which was successfully managed conservatively. Conclusions - This first Scandinavian clinical trial of ESG, documenting the implementation of the procedure at a Norwegian center, demonstrated acceptable feasibility and safety, with large variations in individual weight loss during the 52-week follow-up period