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Photovoltaic Prickle Pear Harvesting Tool  [PDF]
Federico Hahn
Natural Resources (NR) , 2013, DOI: 10.4236/nr.2013.43033
Abstract:

Mexico is the largest cactus exporter of the world and 40% of the production cost is provided from the harvest operation. Many workers are required to operate daily and suffer wrist pain after two weeks of collecting pears with mechanical pruners. A motor driven tool supplied from a photovoltaic system was employed for harvesting; different blades were tested at different cutting speeds. It was found that toothed blades sliced the pears with efficiencies over 90%. Abrasive blades were finally selected as the current required per cut was minimum, permitting a longer battery lifetime before requiring recharging.

Risk Assessment Using Two Different Diagnostic Tools: Metabolic Syndrome and Cardiovascular Risk Score (SCORE)—Data from a Weight Reduction Intervention Study  [PDF]
Janina Willers, Andreas Hahn
Food and Nutrition Sciences (FNS) , 2013, DOI: 10.4236/fns.2013.410134
Abstract: Objective: Risk score models and the diagnosis of a metabolic syndrome are useful for cardiovascular (CV) risk prediction. The identification of individuals with high CV and metabolic risk is essential to provide appropriate prevention and therapy. The present study aims at clarifying whether these indicators are altered by a weight reduction programme. Additionally, which diagnostic tool has a better predictive value is examined. Method: One hundred and twenty overweight and obese subjects aged 30 60 years were included in a 12-week weight reduction programme. The CV risk was assessed by means of German multiple-used risk charts (SCORE) at baseline and at the end of the trial. Furthermore, the prevalence of the metabolic syndrome (three out of five risk factors) was quantified. Results: The initial prevalence of the metabolic syndrome was 63.3% (n = 76) and decreased to 41.7% (n = 50) by the end of the intervention. The SCORE also decreased significantly after twelve weeks (p < 0.001). The percentage of subjects at high risk (SCORE > 5%) was comparatively low (t0: 7.4%, n = 7; t12: 5.3%, n = 5). Conclusion: The weight reduction concept was applicable to improve the CV risk SCORE and decrease the prevalence of the metabolic syndrome. The CV 10-year risk calculated using German risk charts (SCORE) probably underestimated the risk of CV diseases in this collective. In this case, the diagnosis of a metabolic syndrome is more meaningful than risk SCORE calculations.
Gravitational Forces Explained as the Result of Anisotropic Energy Exchange between Baryonic Matter and Quantum Vacuum  [PDF]
Stefan L. Hahn
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.68117
Abstract: Gravitational forces are explained as a result of energy exchange between baryonic matter having the property of mass and the Quantum Vacuum. The derivations are starting with a hypothesis that baryonic matter, particles, atoms and molecules exchange energy with the Quantum Vacuum with zero balance. It is assumed that in absence of an external gravitation field the emission pattern is isotropic. There is no recoil force of radiation. The application of an external gravitation field induces an anisotropy which results in a recoil force of radiation. An ellipsoidal radiation pattern is applied. The eccentricity of the ellipsoid is defined using the maximum possible value of any gravitation field estimated to have the value about 5 × 1012 [m/s2]. A formula is derived for calculating the power of the isotropic radiation. It was shown that two masses attract due to the fact that gravitation field lowers the energy density of the Quantum Vacuum. Using the results of measurements of a binary neutron star by Taylor and Hulse (Nobel Prize in Physics 1993) it was shown that possibly gravitational waves carry negative energy.
Synergistic Effect of Fullerene-Capped Gold Nanoparticles on Graphene Electrochemical Supercapacitors  [PDF]
Virginia Yong, H. Thomas Hahn
Advances in Nanoparticles (ANP) , 2013, DOI: 10.4236/anp.2013.21001
Abstract:

We report the synthesis of graphene/fullerene-capped gold nanoparticle nanocomposite film which was used to construct supercapacitor electrodes. The fullerene-based self-assembled monolayers on gold nanoparticles (AuNPs) were attained via the fullerene(C60)-gold interaction. The fullerene-capped AuNPs effectively separated the graphene sheets preventing aggregation. A synergistic effect was observed—the specific capacitance of graphene/fullerene-capped AuNP electrode is197 F/g, which is higher than that of graphene electrode (31 F/g), graphene/AuNP electrode (126 F/g), and graphene/fullerene electrode (118 F/g). The results render a novel route of synthesis and modification of graphene-based materials for the construction of electrochemical energy storage devices.

Cognitive Principles in Mobile Learning Applications  [PDF]
William B. Huffman, Sowon Hahn
Psychology (PSYCH) , 2015, DOI: 10.4236/psych.2015.64043
Abstract: As m-learning (mobile-learning) applications are rapidly growing, it is important to incorporate principles of human cognition in those applications. In the present study, a foreign language learning application environment was developed using various learning methods in order to identify optimal m-learning applications. Using computer-based learning experiments that assimilate an m-learning environment, participants were tested over their long-term memory retention of newly learned German vocabulary words. Specifically, we compared the effectiveness of rote learning, retrieval practice, repeated retrieval practice, and the keyword method. Experiment 1 showed that repeated retrieval practice was more beneficial for memory especially for longer retention intervals. Experiment 2 yielded that repeated retrieval practice was more effective for learning German vocabulary words than the keyword and rote learning methods. No statistical differences were found between the keyword and rote learning conditions. The present research suggests that retrieval practice can be effectively incorporated in m-learning applications. Implications and future directions are discussed.
Turning Informal Thesauri into Formal Ontologies: A Feasibility Study on Biomedical Knowledge Re-Use
Udo Hahn
Comparative and Functional Genomics , 2003, DOI: 10.1002/cfg.247
Abstract: This paper reports a large-scale knowledge conversion and curation experiment. Biomedical domain knowledge from a semantically weak and shallow terminological resource, the UMLS, is transformed into a rigorous description logics format. This way, the broad coverage of the UMLS is combined with inference mechanisms for consistency and cycle checking. They are the key to proper cleansing of the knowledge directly imported from the UMLS, as well as subsequent updating, maintenance and refinement of large knowledge repositories. The emerging biomedical knowledge base currently comprises more than 240 000 conceptual entities and hence constitutes one of the largest formal knowledge repositories ever built.
Actual Pathogen Detection: Sensors and Algorithms - a Review
Federico Hahn
Algorithms , 2009, DOI: 10.3390/a2010301
Abstract: Pathogens feed on fruits and vegetables causing great food losses or at least reduction of their shelf life. These pathogens can cause losses of the final product or in the farms were the products are grown, attacking leaves, stems and trees. This review analyses disease detection sensors and algorithms for both the farm and postharvest management of fruit and vegetable quality. Mango, avocado, apple, tomato, potato, citrus and grapes were selected as the fruits and vegetables for study due to their world-wide consumption. Disease warning systems for predicting pathogens and insects on farms during fruit and vegetable production are commonly used for all the crops and are available where meteorological stations are present. It can be seen that these disease risk systems are being slowly replaced by remote sensing monitoring in developed countries. Satellite images have reduced their temporal resolution, but are expensive and must become cheaper for their use world-wide. In the last 30 years, a lot of research has been carried out in non-destructive sensors for food quality. Actually, non-destructive technology has been applied for sorting high quality fruit which is desired by the consumer. The sensors require algorithms to work properly; the most used being discriminant analysis and training neural networks. New algorithms will be required due to the high quantity of data acquired and its processing, and for disease warning strategies for disease detection.
Shapley Polygons in 4 x 4 Games
Martin Hahn
Games , 2010, DOI: 10.3390/g1030189
Abstract: We study 4 x 4 games for which the best response dynamics contain a cycle. We give examples in which multiple Shapley polygons occur for these kinds of games. We derive conditions under which Shapley polygons exist and conditions for the stability of these polygons. It turns out that there is a very strong connection between the stability of heteroclinic cycles for the replicator equation and Shapley polygons for the best response dynamics. It is also shown that chaotic behaviour can not occur in this kind of game.
Van der Burg, W., Van Willigenburg, T. (eds): Reflective equilibrium. Essays in honour of Robert Heeger
Susanne Hahn
Poiesis & Praxis , 2001, DOI: 10.1007/PL00000007
Abstract:
Como s?o possíveis deveres de virtude em Kant?
Hahn, Alexandre;
Trans/Form/A??o , 2006, DOI: 10.1590/S0101-31732006000200009
Abstract: this paper intends to show what it consists and which is the importance of investigating and offering an answer to the problem of the possibility of the virtue duties. therefore, we will, at first, approach the problem of the possibility of the virtue duties starting from problems that refer to other a priori synthetic judgments in order to, soon after, indicate the requirements that should be accomplished by the virtue duties so that they are considered possible. this investigation is commited with loparic's semantic interpretation.
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