Tailoring Anderson localization by disorder correlations in 1D speckle potentials

We study Anderson localization of single particles in continuous, correlated, one-dimensional disordered potentials. We show that tailored correlations can completely change the energy-dependence of the localization length. By considering two suitable models of disorder, we explicitly show that disorder correlations can lead to a nonmonotonic behavior of the localization length versus energy. Numerical calculations performed within the transfer-matrix approach and analytical calculations performed within the phase formalism up to order three show excellent agreement and demonstrate the effect. We finally show how the nonmonotonic behavior of the localization length with energy can be observed using expanding ultracold-atom gases

Energy savings measures in compressed air systems

Compressed air is one of the most widely used application energies in the industry, such as good transportability, safety, purity, cleanliness, storage capacity and ease of use. In many countries, compressed air systems account for approximately 10% of the industry’s total electricity consumption. Despite all its advantages, compressed air is expensive, only between 10% and 30% of the energy consumed reaches the point of final use. Energy is lost as heat, leaks, pressure drop, misuse, among others. Energy efficiency measures such as: reducing compressor pressure, lowering air inlet temperature, adequate storage capacity, recovering residual heat from the air compressor and reducing leakage, can produce energy savings between 20% and 60%, with an average return on investment lower than 2 years. This paper analyzes the main energy efficiency measures that can be applied in the CASs, the potential energy savings, implementation costs and return rate of each of them are being calculated giving a necessary tool for companies in their objectives to reduce greenhouse gas emissions and energy consumption

Treatment for T1DM patients by a neuro-fuzzy inverse optimal controller including multi-step prediction

Diabetes Mellitus is a serious metabolic condition for global health associations. Recently, the number of adults, adolescents and children who have developed Type 1 Diabetes Mellitus (T1DM) has increased as well as the mortality statistics related to this disease. For this reason, the scientific community has directed research in developing technologies to reduce T1DM complications. This contribution is related to a feedback control strategy for blood glucose management in population samples of ten virtual adult subjects, adolescents and children. This scheme focuses on the development of an inverse optimal control (IOC) proposal which is integrated by neural identification, a multi-step prediction (MSP) strategy, and Takagi–Sugeno (T–S) fuzzy inference to shape the convenient insulin infusion in the treatment of T1DM patients. The MSP makes it possible to estimate the glucose dynamics 15 min in advance; therefore, this estimation allows the Neuro-Fuzzy-IOC (NF-IOC) controller to react in advance to prevent hypoglycemic and hyperglycemic events. The T–S fuzzy membership functions are defined in such a way that the respective inferences change basal infusion rates for each patient's condition. The results achieved for scenarios simulated in Uva/Padova virtual software illustrate that this proposal is suitable to maintain blood glucose levels within normoglycemic values (70–115 mg/dL); furthermore, this level remains less than 250 mg/dL during the postprandial event. A comparison between a simple neural IOC (NIOC) and the proposed NF-IOC is carried out using the analysis for control variability named CVGA chart included in the Uva/Padova software. This analysis highlights the improvement of the NF-IOC treatment, proposed in this article, on the NIOC approach because each subject is located inside safe zones for the entire duration of the simulatio

Easily retrievable objects among the NEO population

Asteroids and comets are of strategic importance for science in an effort to understand the formation, evolution and composition of the Solar System. Near-Earth Objects (NEOs) are of particular interest because of their accessibility from Earth, but also because of their speculated wealth of material resources. The exploitation of these resources has long been discussed as a means to lower the cost of future space endeavours. In this paper, we consider the currently known NEO population and define a family of so-called Easily Retrievable Objects (EROs), objects that can be transported from accessible heliocentric orbits into the Earth’s neighbourhood at affordable costs. The asteroid retrieval transfers are sought from the continuum of low energy transfers enabled by the dynamics of invariant manifolds; specifically, the retrieval transfers target planar, vertical Lyapunov and halo orbit families associated with the collinear equilibrium points of the Sun-Earth Circular Restricted Three Body problem. The judicious use of these dynamical features provides the best opportunity to find extremely low energy Earth transfers for asteroid material. A catalogue of asteroid retrieval candidates is then presented. Despite the highly incomplete census of very small asteroids, the ERO catalogue can already be populated with 12 different objects retrievable with less than 500 m/s of Δv. Moreover, the approach proposed represents a robust search and ranking methodology for future retrieval candidates that can be automatically applied to the growing survey of NEOs

Care of peripheral intravenous catheters in three hospitals in Spain: Mapping clinical outcomes and implementation of clinical practice guidelines

BACKGROUND: Peripheral intravenous catheters (PIVCs) are the most widely used invasive devices worldwide. Up to 42% of PIVCs are prematurely removed during intravenous therapy due to failure. To date, there have been few systematic attempts in European hospitals to measure adherence to recommendations to mitigate PIVC failures. AIM: To analyse the clinical outcomes from clinical practice guideline recommendations for PIVC care on different hospital types and environments. METHODS: We conducted an observational study in three hospitals in Spain from December 2017 to April 2018. The adherence to recommendations was monitored via visual inspection in situ evaluations of all PIVCs inserted in adults admitted. Context and clinical characteristics were collected by an evaluation tool, analysing data descriptively. RESULTS: 646 PIVCs inserted in 624 patients were monitored, which only 52.7% knew about their PIVC. Regarding PIVC insertion, 3.4% (22/646) patients had at least 2 PIVCs simultaneously. The majority of PIVCs were 20G (319/646; 49.4%) and were secured with transparent polyurethane dressing (605/646; 93.7%). Most PIVCs (357/646; 55.3%) had a free insertion site during the visual inspection at first sight. We identified 342/646 (53%) transparent dressings in optimal conditions (clean, dry, and intact dressing). PIVC dressings in medical wards were much more likely to be in intact conditions than those in surgical wards (234/399, 58.7% vs. 108/247, 43.7%). We identified 55/646 (8.5%) PIVCs without infusion in the last 24 hours and 58/646 (9.0%) PIVCs without infusion for more than 24 hours. Regarding PIVC failure, 74 (11.5%) adverse events were identified, all of them reflecting clinical manifestation of phlebitis. CONCLUSIONS: Our findings indicate that the clinical outcome indicators from CPG for PIVC care were moderate, highlighting differences between hospital environments and types. Also, we observed that nearly 50% of patients did not know what a PIVC is

Diagnostic tool for radical improvement in business processes

The present work presents a diagnostic tool applicable in any business sector; it works as a support to managers for decision-making towards the need for a radical improvement of processes. A literary review was conducted to collect case studies in order to identify the problems it addresses and the impacts generated by the process of reengineering application in organizations. Through conceptual modeling and synthesization, some diagnostic questions were formulated related to the problems that reengineering has addressed in the literature, and an evaluation model was built that allows organizations to identify what type of problem the organization has, its processes or departments, which should be approached from a radical improvement approach. Finally a diagnostic tool with an evaluation method was formulated, to recommend initiate process improvement either organization, departments o process, formulated fully integrable with PDCA cycle and evaluation or monitoring phases for systems like business activity monitoring based on IT systems, relevant in today's contexts when most of the nowadays organization are technology-based, and progressive improvements do not become a pragmatic and agile alternative in the business context

Psychometric properties and invariance of an English self-efficacy scale for university students in Peru

"Background: English is a global language used to communicate with members of the international community. Self-efficacy in learning English is an important factor that is influenced by perceived importance, interest, and beliefs about the ability to successfully perform tasks in English. Objective: The aim is to develop and validate a measurement instrument to assess English self-efficacy. Methods: A total of 453 students from different Peruvian universities participated, with ages ranging from 18 to 60 years (M = 23; SD = 6.18). Statistical techniques for latent variables were used and recommendations for educational and psychological tests were followed in its construction. The sample was divided into two groups to perform exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Results: The English Self-Efficacy Scale (ESS-P) is representative and relevant in terms of its item content (Aiken’s V > 0.70). Its internal structure is organized into three first order factors and a second order factor that are consistent with the theoretical proposal and was confirmed through CFA with excellent goodnessof-fit indices (χ2  = 1184.9, gl = 626, CFI = 0.92, TLI = 0.92, RMSEA = 0.06 y SRMR = 0.04). It also has adequate internal consistency in its three factors (Reading α/ω = 0.96), Oral Communication (α/ω = 0.95), and Writing (α/ω = 0.97) and the whole scale (α/ω = 0.98), is invariant with respect to sex, and has a conceptual relationship with variables such as academic self-efficacy and exam anxiety. Conclusion: The ESS-P is a measurement instrument with evidence of validity, factorial invariance, and good reliability of its scores. Therefore, it can be used in future studies in the academic contex

Bayesian spatio-temporal model with INLA for dengue fever risk prediction in Costa Rica

Due to the rapid geographic spread of the Aedes mosquito and the increase in dengue incidence, dengue fever has been an increasing concern for public health authorities in tropical and subtropical countries worldwide. Significant challenges such as climate change, the burden on health systems, and the rise of insecticide resistance highlight the need to introduce new and cost-effective tools for developing public health interventions. Various and locally adapted statistical methods for developing climate-based early warning systems have increasingly been an area of interest and research worldwide. Costa Rica, a country with micro-climates and endemic circulation of the dengue virus (DENV) since 1993, provides ideal conditions for developing projection models with the potential to help guide public health efforts and interventions to control and monitor future dengue outbreaks