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排序方式: 共有116条查询结果,搜索用时 15 毫秒
71.
Perspectives for the production of bioethanol from wood and straw in Austria: technical, economic, and ecological aspects 总被引:1,自引:1,他引:0
Philipp Kravanja Kurt K?nighofer Lorenza Canella Gerfried Jungmeier Anton Friedl 《Clean Technologies and Environmental Policy》2012,14(3):411-425
Bioethanol produced from lignocellulosic resources is a promising candidate for the replacement of fossil fuels. In this study, we aim to determine the perspectives to produce lignocellulosic ethanol in Austria. Technical, environmental and economic aspects are being considered. Thirteen biotechnological production concepts using the raw materials straw and softwood were established and simulated with the steady state flowsheeting software IPSEpro. Bioethanol production cost and greenhouse gas (GHG) emissions for each system were calculated based on mass and energy balances obtained from process simulation. The emission of GHGs along the entire bioethanol process chain (“from well to wheel”) are compared to two reference systems producing the same amounts of by-products. In all concepts, process heat and considerable amounts of the by-products electricity, heat, pellets, C5 molasses, or biomethane could be obtained from residual biomass. Compared to a reference system driven by fossil energy, GHG emissions can be reduced by up to 76%. The production cost of ethanol was found to between 0.66?€ and 0.94?€ per liter of gasoline equivalent. The type and amount of by-product influence technical, economic, and environmental performance significantly. Converting all straw and softwood available in Austria to ethanol would result in an annual production of 340?kt. 相似文献
72.
Rocío García-Becerra Nancy Santos Lorenza Díaz Javier Camacho 《International journal of molecular sciences》2013,14(1):108-145
Breast cancer is the most frequent malignancy diagnosed in women. Approximately 70% of breast tumors express the estrogen receptor (ER). Tamoxifen and aromatase inhibitors (AIs) are the most common and effective therapies for patients with ERα-positive breast cancer. Alone or combined with chemotherapy, tamoxifen significantly reduces disease progression and is associated with more favorable impact on survival in patients. Unfortunately, endocrine resistance occurs, either de novo or acquired during the course of the treatment. The mechanisms that contribute to hormonal resistance include loss or modification in the ERα expression, regulation of signal transduction pathways, altered expression of specific microRNAs, balance of co-regulatory proteins, and genetic polymorphisms involved in tamoxifen metabolic activity. Because of the clinical consequences of endocrine resistance, new treatment strategies are arising to make the cells sensitive to tamoxifen. Here, we will review the current knowledge on mechanisms of endocrine resistance in breast cancer cells. In addition, we will discuss novel therapeutic strategies to overcome such resistance. Undoubtedly, circumventing endocrine resistance should help to improve therapy for the benefit of breast cancer patients. 相似文献
73.
Colzato Lorenza S.; Bajo Maria Teresa; van den Wildenberg Wery; Paolieri Daniela; Nieuwenhuis Sander; La Heij Wido; Hommel Bernhard 《Canadian Metallurgical Quarterly》2008,34(2):302
It has been claimed that bilingualism enhances inhibitory control, but the available evidence is equivocal. The authors evaluated several possible versions of the inhibition hypothesis by comparing monolinguals and bilinguals with regard to stop signal performance, inhibition of return, and the attentional blink. These three phenomena, it can be argued, tap into different aspects of inhibition. Monolinguals and bilinguals did not differ in stop signal reaction time and thus were comparable in terms of active-inhibitory efficiency. However, bilinguals showed no facilitation from spatial cues, showed a strong inhibition of return effect, and exhibited a more pronounced attentional blink. These results suggest that bilinguals do not differ from monolinguals in terms of active inhibition but have acquired a better ability to maintain action goals and to use them to bias goal-related information. Under some circumstances, this ability may indirectly lead to more pronounced reactive inhibition of irrelevant information. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
74.
Lorenza Ferrari Flavio Gatti Daniele Pergolesi Maria Ribeiro Gomes Daniela Bagliani Riccardo Valle Simeone Dussoni Luigi Piro Luca Colasanti Claudio Macculi Marco Barbera Emanuele Perinati 《Journal of Low Temperature Physics》2008,151(1-2):271-276
In the framework of the Italian Space Agency R&D project, which is focused on the development of microcalorimeters for applications
on astrophysics, we are studying different methods for TES microcalorimeter production and developing simulations of various
absorber performances. In this paper are presented preliminary results obtained with two different geometries: front back
and planar on SiN membrane.
相似文献
75.
Alessio Meoli Elena Dordoni Lorenza Petrini Francesco Migliavacca Gabriele Dubini Giancarlo Pennati 《Journal of Materials Engineering and Performance》2014,23(7):2606-2613
Despite their success as primary treatment for vascular diseases, Nitinol peripheral stents are still affected by complications related to fatigue failure. Hip and knee movements during daily activities produce large and cyclic deformations of the superficial femoral artery, that concomitant to the effects of pulsatile blood pressure, may cause fatigue failure in the stent. Fatigue failure typically occurs in cases of very extended lesions, which often require the use of two or more overlapping stents. In this study, finite element models were used to study the fatigue behavior of Nitinol stents when subjected to cyclic axial compression in different conditions. A specific commercial Nitinol stent was chosen for the analysis and subjected to cyclic axial compression typical of the femoral vascular region. Three different configurations were investigated: stent alone, stent deployed in a tube, and two overlapping stents deployed in a tube. Results confirm that stent oversizing has an influence in determining both the mean and amplitude strains induced in the stent and plays an important role in determining the fatigue response of Nitinol stents. In case of overlapping stents, numerical results suggest higher amplitude strains concentrate in the region close to the overlapping portion where the abrupt change in stiffness causes higher cyclic compression. These findings help to explain the high incidence of stent fractures observed in various clinical trials located close to the overlapping portion. 相似文献
76.
Federica Del Chierico Pamela Vernocchi Bruno Dallapiccola Lorenza Putignani 《International journal of molecular sciences》2014,15(7):11678-11699
The Mediterranean diet (MD) is considered one of the healthiest dietary models. Many of the characteristic components of the MD have functional features with positive effects on health and wellness. The MD adherence, calculated through various computational scores, can lead to a reduction of the incidence of major diseases (e.g., cancers, metabolic and cardiovascular syndromes, neurodegenerative diseases, type 2 diabetes and allergy). Furthermore, eating habits are the main significant determinants of the microbial multiplicity of the gut, and dietary components influence both microbial populations and their metabolic activities from the early stages of life. For this purpose, we present a study proposal relying on the generation of individual gut microbiota maps from MD-aware children/adolescents. The maps, based on meta-omics approaches, may be considered as new tools, acting as a systems biology-based proof of evidence to evaluate MD effects on gut microbiota homeostasis. Data integration of food metabotypes and gut microbiota “enterotypes” may allow one to interpret MD adherence and its effects on health in a new way, employable for the design of targeted diets and nutraceutical interventions in childcare and clinical management of food-related diseases, whose onset has been significantly shifted early in life. 相似文献
77.
Texture effects on design of Mg biodegradable stents 总被引:1,自引:0,他引:1
Maurizio Vedani Qiang Ge Wei Wu Lorenza Petrini 《International Journal of Material Forming》2014,7(1):31-38
ZM21 and AZ31B magnesium alloy tubes were hot extruded by a laboratory equipment in order to produce precursors for biodegradable stents. The microstructure and the texture evolution during the extrusion were investigated and related to the resulting mechanical properties. The tubes featured a homogeneous and refined equiaxed grain structure due to dynamic recrystallization experienced during the extrusion process. Electron backscattering diffraction analysis along the longitudinal section of the tubes revealed a typical ‘basal’ type texture featuring hexagonal basal plane aligned parallel to the longitudinal section of the tubes. Tensile and compression tests on different size of tubes showed a strong asymmetry in mechanical properties, the tensile strength being significantly higher than the strength measured in compression. Data about tension-compression behavior were related to crystallographic texture of samples and to the occurrence preferred {10–12} <10–11> twinning in compression. The significance of the tension-compression behavior is analyzed in view of the application of the extruded tubes for biodegradable stents, especially considering the stages of expansion and scaffolding. The importance of considering the above effects in stent design and modeling is highlighted in order to improve performance and reliability of such devices. 相似文献
78.
Daniela Mileva Dario Cavallo Lorenza Gardella Giovanni C. Alfonso Giuseppe Portale Luigi Balzano René Androsch 《Polymer Bulletin》2011,67(3):497-510
The solidification of random isotactic copolymers of propylene and 1-butene has been followed in real time by wide-angle X-ray
scattering as a function of the rate of cooling the quiescent liquid. The experimental setup allowed simultaneous recording
of cooling curves—sample temperature as a function of time—and X-ray patterns at high sampling rate of 20 Hz. This approach
allowed establishing a correlation between cooling rate, temperature of crystallization/mesophase formation, and X-ray structure,
which formerly has only been observed ex situ, after completion of structure formation during cooling and subsequent aging.
It is quantitatively confirmed that addition of 1-butene co-units into the propylene chain allows mesophase formation on cooling
the melt at distinctly lower rate than in case of the homopolymer. The experimental results are compiled into a continuous
cooling transformation (CCT) diagram and compared with data obtained earlier on random copolymers of propylene with ethylene. 相似文献
79.
We present a self-organized downlink power control for interference management when Home eNodeBs (HeNBs) work in co-channel operation with the macrocell system. The main novelty with regards to previous works is that we provide a completely autonomous framework, considering 3GPP release?11 hypothesis of non availability of X2 interface between evolved NodeBs (eNBs) and HeNBs. In this situation, the HeNB has to make autonomous decisions without receiving any feedback from the macro network. We model the HeNBs as a multiagent system where each node is an independent agent able to learn through Reinforcement Learning (RL) techniques a downlink power allocation policy for different interference situations. To deal with the lack of information in the scenario, we rely on the theory of Partially Observable Markov Decision Process (POMDP). POMDP works on the basis of a set of beliefs that the HeNB builds considering the impact it causes to the macrocell system. To gather this system performance information, we propose that HeNBs use spatial interpolation techniques, such as ordinary Kriging. Results show that the proposed approach allows HeNBs to autonomously learn a power allocation policy to coexist with the macro network, in a 3GPP compliant fashion, and without introducing overhead signaling in the system. 相似文献
80.
A method for learning the membership of strings belonging to finite languages is proposed. The learning is based on sets of strings of fuzzy linguistic variables. These strings belong to languages, each one of which describes a class of phenomena. The learning algorithm attempts to maximize the number of times a string reaches the highest possibility value for the language representing the class of phenomena containing the sample described by the string. Application to automatic speech recognition is described, and experimental results are presented showing the benefits of the proposed method. 相似文献