Exploration, exploitation and innovation performance: disentangling the evolution of industry

The evolution of industry has recently attracted the attention of scholars studying the relationships between exploration and exploitation strategies and innovation performance. Surprisingly, although extant research has already acknowledged its multidimensional character, it has only been analyzed in an aggregate fashion. In this paper, we distinguish two components of the evolution of industry, the pace of market evolution and the pace of technology evolution, and we elaborate on their different impacts in the context of exploration and exploitation strategies. More precisely, we argue that while a rapid pace of technology evolution has opposite impacts on the relationships between exploration (positive), exploitation (negative) and innovation performance, a rapid pace of market evolution positively affects both exploration and exploitation. Our findings provide substantial support for our prediction using a large panel of Spanish innovating firms for the period 2008–2012

The effect of training and experience on mass casualty incident triage performance: Evidence from emergency personnel in a high complexity university hospital

Mass casualty incident (MCI) can occur at any time and place and health care institutions must be prepared to deal with these incidents. Emergency department staff rarely learn how to triage MCI patients during their medical or nurse degrees, or through on-the-job training. This study aims to evaluate the effect of training and experience on the MCI triage performance of emergency personnel. METHODOLOGY: This was a cross-sectional prospective study that analyzed the performance of 94 emergency department staff on the triage classifications of 50 trauma patients, before and after a short training in MCI triage, while taking into account their academic background and work experience. RESULTS: The participants were assigned initially to one of two groups: low experience if they had less than 5 years of practice, and high experience if they had more than 5 years of practice. In the low experience group, the initial accuracy was 45.76 percent, over triage 45.84 percent, and subtriage 8.38 percent. In the high experience group, the initial accuracy was 53.80 percent, over triage 37.66 percent, and sub triage 8.57 percent. POSTINTERVENTION RESULTS: In the low experience group, the post intervention accuracy was 63.57 percent, over triage 21.15 percent, and subtriage 15.30 percentage. In the high experience group, the postintervention accuracy was 67.66 percentage, over triage 15.19 percentage, and subtriage 17.14 percentage. CONCLUSION: Upon completion of this study, it can be concluded that MCI triage training significantly improved the performance of all those involved in the workshop and that experience plays an important role in MCI triage performance

Optimizing LED Performance for LiFi:Bandwidth versus Efficiency

Optical transmission is attractive for future wireless communication because signals can be confined in a specific coverage area. In designing a system based on LEDs, the trade-off between transmission bandwidth and optical power is important. As a common practice with micro-LEDs, one may drive the LED at a high current density, beyond the optimum efficiency point, to boost the bandwidth. Bit rates of multiple gigabit/s have been demonstrated, but coverage is small. However, using high current densities is discouraged by self-heating, as only a part of the electrical power is converted to optical power. A rising temperature reduces efficiency, causing a degradation of the SNR. We combine multiple models, not only the ABC photon generation and the LED dynamic responses subject to a rapidly varying current but also, the junction voltage method to estimate its temperature. We quantify the achieved throughput in a DCO-OFDM link at different temperatures. This leads to the insight that there is an optimal size of the active region and an optimal current density that maximizes the throughput of the wireless link at different temperatures. The work presented here builds upon work that we published earlier, and we place this in the perspective of a combined system model

Quasi-SU(3) truncation scheme for even-even sd-shell nuclei

The Quasi-SU(3) symmetry was uncovered in full pf and sdg shell-model calculations for both even-even and odd-even nuclei. It manifests itself through a dominance of single-particle and quadrupole-quadrupole terms in the Hamiltonian used to describe well-deformed nuclei. A practical consequence of the quasi-SU(3) symmetry is an efficient basis truncation scheme. In a recent work was shown that when this type of Hamiltonian is diagonalized in an SU(3) basis, only a few irreducible represntations (irreps) of SU(3) are needed to describe the Yrast band, the leading S = 0 irrep augmented with the leading S = 1 irreps in the proton and neutron subspaces. In the present article the quasi-SU(3) truncation scheme is used, in conjunction with a "realistic but schematic" Hamiltonian that includes the most important multipole terms, to describe the energy spectra and B(E2) transition strengths of 20-Ne, 22-Ne, 24-Mg and 28-Si. The effect of the size of the Hilbert space on both sets of observables is discussed, as well as the structure of the Yrast band and the importance of the various terms in the Hamiltonian.Comment: 30 pages, 8 figures. Submited to Nucl. Phys.

Pseudo SU(3) shell model: Normal parity bands in odd-mass nuclei

A pseudo shell SU(3) model description of normal parity bands in 159-Tb is presented. The Hamiltonian includes spherical Nilsson single-particle energies, the quadrupole-quadrupole and pairing interactions, as well as three rotor terms. A systematic parametrization is introduced, accompained by a detailed discussion of the effect each term in the Hamiltonian has on the energy spectrum. Yrast and excited band wavefunctions are analyzed together with their B(E2) values.Comment: 29 pages, 6 figure

Large scale PV systems under non-uniform and fault conditions

Current codes of practice for PV systems lack detailed guidance regarding circuit mismatch, over or reverse current protection and unbalanced operational conditions in large PV systems. Experimental work in this field is expensive and limited by hardware and environmental resources. The available commercial simulation tools do not rigorously model the complex behaviour of PV systems operating under non-uniform conditions. In this paper a detailed cell-by-cell model of large scale PV systems is developed. The parameter set used for simulations is based on real PV modules power tolerance data and the variance in its principal parameters, thus representing a realistic power frequency distribution. The model is used to estimate and analyse losses due to circuit mismatch, analyse the causes of reverse current in the system's strings and its consequences in the system performance and to estimate energy losses due to string's fuses failures

Late Quaternary palaeohydrology of Lake Huinaymarca (Bolivia)

L'analyse des associations d'ostracodes présents dans les échantillons prélevés dans les sédiments du lac Huinaymarca permet de retracer l'évolution hydrobiologique du lac (variation du niveau lacustre, variation de l'oxygénation par rapport à la position de la thermocline, interconnections avec les différents bassins du lac) au cours des dix derniers millénaire

Computational fluid dynamicssimulation of cooling system for copper smelter gases by TenienteConverter with evaporative cooler

En la fundición de sulfuros de cobre los gases provenientes del horno convertidor tipo Teniente son altamente corrosivos y tóxicos, por lo que deben ser tratados para evitar que impacten el medio ambiente. En el presente estudio se propone una metodología novedosa para la simulación del sistema de captación y enfriamiento de los gases de fundición mediante el uso de mecánica computacional de fluidos (CFD), aplicado a los gases provenientes de un convertidor de cobre tipo Teniente, donde se propone una serie de suposiciones que permite adaptar los modelos físicos para su simulación mediante CFD, además de realizar una validación de los resultados mediante instrumentos a escala industrial reales. Mediante la metodología propuesta es posible obtener un modelo de simulación del comportamiento de los gases de fundición con un error relativo aceptable. Esto en términos prácticos indica que las tendencias que siguen los gases metalúrgicos a lo largo de su recorrido por la campana y cámara de enfriamiento en la simulación pueden ser confiables para obtener una buena aproximación del comportamiento térmico de los gases al interior de la red de manejo de gases estudiada.In the copper sulfides smelting process, the Teniente-type converter generates highly corrosive and toxic gases, which is why treating them is crucial in order to avoid environmental damage. The present study proposes a new methodology to simulate the capture and cooling system of smelting gases through the application of Computational Fluid Dynamics (CFD) to the gases that emanate from a Teniente-type converter, where a series of assumptions that allow the adaptation of the physical model for the CFD simulation are proposed along with the validation of the results using real industrial-scale instruments. By applying this method, it is possible to obtain a behavioral simulation model of the smelting gases with an acceptable relative error. In practical terms, this means that the tendencies that metallurgical gases show in the simulation flowing through the bell and the cooling chamber can be trusted to predict the thermal behavior of the gases contained in the gas management network.Peer Reviewe

Sacha inchi oil (Plukenetia volubilis) stabilized with antioxidants for addition in fresh cheese

Sacha Inchi (Plukenetia volubilis) is a nut that has been grown in the Amazon Rainforest and the high Andes Mountains of Peru for countless centuries. The oil of this nut, natural source of omega 3, 6 and 9, has been recognized by its high antioxidant capacity in humans. In this work, oil from Sacha Inchi was fortified with two commercial antioxidants (Ecoprol 2020 and tocopherol) in order to prepare a fresh cheese from cow's milk. The antioxidant capacities of Sacha Inchi and commercial antioxidants were used as preservatives with the purpose to increase the shelf-life of fresh cheese besides nutritional content. The factorial method was necessary to prepare seven formulations in order to find the optimal concentration of the antioxidants added to Sacha Inchi oil andthe addition of this oil to the fresh cheese. A sensory analysis was performed to choose the best formulation. The results showed that an oil formulation (F4) with tocopherol (150 mg/kg of oil) and Ecoprol 2020 (1000 mg/kg of oil) displayed the lowest peroxide values (PI: 2.6 ± 0.1 meq O2/kg of oil, p < 0.001) and it was able to reduce approximately 50% of fatty acid oxidation in Sacha Inchi oil in relation to the PI control. Then, F4 was used to elaborate further nine formulations (F’1 – F’9), enriched with Sacha Inchi oil (1 to 4%) to prepare the fresh cheese. Microbiological analysis for all formulations were performed (limits of mold, yeasts, coliforms, salmonella, and  bacteria) in order to meet the legal requirements of health and safety in Peru. The cheese taste acceptability was determined through the sensorial evaluation, which reached 7.2 according to the 9- hedonic scale for F'5. Thus, an optimum fresh cheese was obtained from the formulation (F’5) with 22.5g/L of salt and 2.5% of Sacha Inchi oil enriched with 150 mg/kg of tocopherol and 1000 mg/kg of Ecoprol 2020. The cheese shelf-life was also evaluated, increasing it up from 7 days to 16 days in refrigeration. Key words: cheese, antioxidant, Sacha Inchi, shelf-life, Ecoprol 2020, tocophero