Literatura académica sobre el tema "Efficiency improvement mechanism"
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Artículos de revistas sobre el tema "Efficiency improvement mechanism"
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Liu, Long Tao y Wen Tang. "Improvement of a SIP Security Mechanism". Applied Mechanics and Materials 263-266 (diciembre de 2012): 2929–32. http://dx.doi.org/10.4028/www.scientific.net/amm.263-266.2929.
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SIP is one of the mainstream protocols in the VoIP. A majority of SIP’s security mechanism only provides a single direction authentication from server to client such as HTTP digest authentication. To improve the present situation, a new security mechanism of SIP based on the improved HTTP digest authentication is put forward in this study. This improved security mechanism not only provides a double direction authentication between the server and client but also reduces the expenses of the server and increases the authentication efficiency thanks to its low computational complexity.
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Yan, Qing You, Xin Fa Tang, Juan Juan Cao y Chao Kong. "Growth Ceiling of Energy Efficiency and Countermeasure Archetype in Electric Power Supply and Demand System". Applied Mechanics and Materials 291-294 (febrero de 2013): 1297–302. http://dx.doi.org/10.4028/www.scientific.net/amm.291-294.1297.
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Energy efficiency depends on the profit that the consumed energy contributes to human need system for the sustainable development. With the increasing importance of coordinate development of environment, economic and electric power system, it is more and more difficult to choose the right improvement path and mechanism of energy efficiency in electric-power supply and demand system. After analyzing the feedback mechanism of energy efficiency improvement of the electric power supply and demand system, energy efficiency improvement which caused the growth ceiling was found along with some inhibition factors in the process of energy efficiency improvement. In view of the energy efficiency improvement growth ceiling of the electric-power supply and demand system, the end treatment mechanism was introduced as a countermeasure which inputs environmental costs to the power supply chain. Furthermore, government guides and participates in energy efficiency investment, which was regarded as another countermeasure attached much importance. So the improvement of energy efficiency in supply and demand system of electric power can be maximized.
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Zhou, Pengfei, Mengyu Han y Yang Shen. "Impact of Intelligent Manufacturing on Total-Factor Energy Efficiency: Mechanism and Improvement Path". Sustainability 15, n.º 5 (21 de febrero de 2023): 3944. http://dx.doi.org/10.3390/su15053944.
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Intelligent technology is the core driving force of the fourth industrial revolution, which has an important impact on high-quality economic development. In this paper, the panel data of 30 provinces from 2006 to 2019 were selected to construct a regression model to conduct an empirical analysis on the role and mechanism of intelligent manufacturing in improving total factor energy efficiency. The research results show that first, the productivity effect, scale effect and resource allocation effect of intelligent manufacturing can significantly improve the energy efficiency of the total factor, and the conclusion is still established after endogenous treatment and robustness testing. Second, the results of the action mechanism show that labor price distortion and carbon emission trading policy are important mechanisms for intelligent manufacturing to improve total-factor energy efficiency. Specifically, the corrected labor price can enhance the motivation of enterprise research and development and innovation and solve the dilemma of the low-end industrial structure, thus improving the efficiency of total-factor energy efficiency. The carbon emission trading policy strengthens the willingness of enterprises to improve the process, eliminate backward equipment and increase the research and development of green technology, and it has a positive regulatory role in the process of improving total-factor energy efficiency in intelligent manufacturing.
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SHEN, Fengiman, Takanobu INADA, Kensaku YAMAMOTO y Yuji IWANAGA. "Combustion Mechanism and Improvement of Combustion Efficiency of Single Pulverized Coal". Tetsu-to-Hagane 80, n.º 1 (1994): 7–12. http://dx.doi.org/10.2355/tetsutohagane1955.80.1_7.
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Michaelowa, Axel y D. Hayashi. "Methodological challenges for energy efficiency improvement under the clean development mechanism". IOP Conference Series: Earth and Environmental Science 6, n.º 20 (1 de febrero de 2009): 202011. http://dx.doi.org/10.1088/1755-1307/6/20/202011.
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Skorokhvatov, Oleg, Alexey Kovalchuk, Dmytry Maksymchuk, Oleksandr Bosyi y Alexey Malishkin. "IMPROVEMENT OF TENSIONING MECHANISM TRACKS FOR TRACTOR ENGINE". Collection of scientific works of Odesa Military Academy, n.º 16 (11 de febrero de 2022): 43–47. http://dx.doi.org/10.37129/2313-7509.2021.16.43-47.
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The article poses a scientific problem, which is solved by using electromechanical mechanisms with an automatic control scheme and tracking the tension of the caterpillar within the required limits. The analysis of scientific papers revealed a number of disadvantages that are inherent in tracked propellers with existing track tensioning mechanisms: a significant drop in the efficiency at high speeds of a track with a rubber-metal hinge due to high stretching coefficients, which leads to a decrease in the coefficient of adhesion of the track; significant deterioration in maneuverability due to the possibility of the decrease of the track from the idler wheel under certain conditions; the inability to change the tension of the tracks when turning the machine, the inability to automatically respond to a change in the type of soil. Summing up the results of the literature review on the topic, we can single out a part of the previously unsolved problem, namely: the problem of matching the track tension to the external and internal operating conditions of the tracked mover is multifactorial, and its solution is a complex technical problem. Such mechanisms use widely adjustable DC motors with built-in electromagnetic brakes. It is obvious that the installation of these electric motors will provide the necessary speed, automatic or in accordance with the signals of the human operator, the necessary regulation of the tension of the tracks. which will significantly increase the controllability of the tracked vehicle at high speeds, significantly increase the patency of the tracked vehicle, obtain a positive effect on the dynamic performance of the tracked vehicle, achieve the maximum increase in the maximum speed, increase the efficiency of the tracked propeller up to 10% depending on the driving conditions by reducing the caterpillar bypass, reduce fuel consumption by up to 6% by increasing the efficiency of the caterpillar mover, increase the durability of the tracks. Keywords: combat vehicles, tracked chassis, weapons and military equipment repair.
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Huabai, Bu y Bu Jiaqi. "Research on the Improvement of Village Governance Efficiency Based on Blockchain Technology". Journal of Agricultural Science 12, n.º 9 (15 de agosto de 2020): 192. http://dx.doi.org/10.5539/jas.v12n9p192.
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It is known that China is in the critical “triple overlap” period of the history of social transformation, the fourth industrial revolution, and new globalization. As a disruptive technology, blockchain has solved the “trust construction” and causing a revolution in the social governance model. The article uses blockchain technology as a means to solve the problems of the existing rural governance structure and governance capability system, analyzes the mechanism and implementation bottleneck of blockchain technology, and proposes countermeasures and policy suggestions to improve the effectiveness of village governance, such as the distributed characteristics and the traceable characteristics of the blockchain can be used to build a multi-level response and personalized service integration and a self-organized operation mechanism in rural areas to promote governance responsibility mechanisms and reduce the risk of information fragmentation, data uncertainty, and governance control risks, etc. These policies and suggestions provide a good theoretical basis and method guidance for China’s rural revitalization strategy.
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Tang, Ning, Yumei Xia, Yijie Zhan, Junhao Dan, Mulan Yu, Xiaolan Bu y Mengliang Cao. "Improvement of Chloroplast Transformation Using CRISPR/Cas9". Journal of Biobased Materials and Bioenergy 14, n.º 3 (1 de junio de 2020): 401–7. http://dx.doi.org/10.1166/jbmb.2020.1970.
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Chloroplasts are organelles that contain genetic materials (DNA) in higher plant cells. The special genetic characteristics of chloroplasts mean that plasmid transformation has important research value, so it has become an important research direction second to nuclear transformation. Although the techniques of chloroplast genome modification have been successfully applied in tobacco and extended to other high plants, there are still many limitations. Exogenous genes are integrated into the chloroplast genome through homologous recombination. Therefore, the low efficiency of homologous recombination directly limits transformation efficiency. Gene editing with fixed-point cutting function and DNA damage repair mechanism may effectively improve the efficiency. In the present study, we aimed to use CRISPR/Cas9 to cut the site between two homologous recombinant fragments in chloroplast transformation to improve the efficiency by activating the DNA damage repair mechanism. The Cas9 gene and gRNA were added to the chloroplast transformation system of tobacco by co-transformation or integration into a transformation vector. The acquired resistant plants were screened by multiple selection of spectinomycin and chloroplast DNA was isolated for molecular detection by PCR. The results showed that the efficiency of chloroplast transformation increased by 6–10 times with the addition of gene editing technology. Although the transformation efficiency was still far below the level of nuclear transformation, this study may help to increase the efficiency of the plant chloroplast transformation system, and expand the types of plant receptors.
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Wang, Zhan Jie, Wen Chen y Hai Long Wang. "Improvement on Real-Time Capability of Heartbeat Mechanism". Advanced Materials Research 108-111 (mayo de 2010): 938–42. http://dx.doi.org/10.4028/www.scientific.net/amr.108-111.938.
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Heartbeat mechanism is the key technology of fault detection in cluster system, and the performance of heartbeat detection restricts the efficiency of high-availability clusters. Heartbeat packets will be delayed or even lost in the case of system or network overload, leading to the lack of real-time detection, the increased misjudgment rate, and reducing the reliability of the system. Aiming at the issue, this paper presented a new real-time heartbeat mechanism. By controlling the time of sending heartbeat packets, real-time Ethernet TTEP avoids the network delay and collision, which will speed up the detection of node failure, thereby increase the availability and stability of cluster system.
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Chen, Hucheng, Rui Nie, Wei Han y Jinhao Qiu. "Improvement mechanism of energy conversion efficiency in ultrasonic motor with flexible rotor". Ultrasonics 120 (marzo de 2022): 106659. http://dx.doi.org/10.1016/j.ultras.2021.106659.
Texto completoTesis sobre el tema "Efficiency improvement mechanism"
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Zhao, Yunhai. "Interface engineering and absorber with composition gradient for high-efficiency Kesterite solar cells". Electronic Thesis or Diss., Université de Rennes (2023-....), 2024. http://www.theses.fr/2024URENS048.
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Dans cette thèse, les propriétés de transport des porteurs de charge, le processus de croissance des grains, le mécanisme de perte de VOC et les possibilités d'amélioration du rendement des cellules solaires de CZTSSe ont été étudiés. L'importante perte de VOC et le faible facteur de remplissage des cellules solaires CZTSSe sont les principaux défis pour l'amélioration du rendement. Cela est principalement dû à la mauvaise qualité de l'interface arrière, à l'alignement non optimisé des bandes et à la présence des phases secondaires dans l'absorbeur. Trois approaches ont été utilisées dans ce travail pour améliorer le rendement de ce cellules PV. Premièrement, une couche intermédiaire de WO3 a été introduite dans l'interface arrière pour inhiber la réaction indésirable entre la couche d'tungsten et l'absorbeur. Deuxièmement, l'alignement des bandes et la présence de phases secondaires à l'interface avant ont été améliorés en même temps par un traitement de sulfuration à basse température. Enfin, la conception et la réalisation d'une couche absorbeure à double gradient de band-gap en CZTSSe ont facilité la séparation et l'extraction des porteurs de charge. Des cellules solaires en CZTSSe avec un rendement de conversion photovoltaïque de 13,7% ont été obtenues. Ces très bons résultats, obtenus grâce à une meilleure comprehnsion du mécanisme de pertes, pourraient être une excellente base pour des améliorations futuresIn this thesis, the transport properties of charge carriers, grain growth process, VOC loss mechanism and efficiency improvement possibilities of CZTSSe solar cells were investigated. The large VOC loss and low FF of CZTSSe solar cells are the main challenges for efficiency improvement. This is mainly due to the poor quality of the rear interface, the non-optimized alignment of the bandgaps and the secondary phases in the absorber. Three approaches were used in this work to improve the performance of this type of PV cells. First, an interlayer of WO3 was introduced into the back interface to inhibit the unwanted reaction between the WO3 layer and the absorber. Second, the alignment of the bands and the presence of secondary phases at the front interface have been improved at the same time by a low temperature sulfurization treatment. Finally, the design and production of a double band-gap gradient absorber layer in CZTSSe facilitated the separation and extraction of charge carriers. CZTSSe solar cells with a photovoltaic conversion efficiency of 13.7% were obtained. These very good results, obtained thanks to a better understanding of the loss mechanism, could be an excellent basis for future improvements
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Мищишин, Ольга Львівна. "Формування та розвиток транскордонних кластерів". Diss., Національний університет "Львівська політехніка", 2020. https://ena.lpnu.ua/handle/ntb/56112.
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Tang, U. Fai. "Efficiency improvement of micro-mobility with intra-domain multicast-based mechanisms". Thesis, University of Macau, 2006. http://umaclib3.umac.mo/record=b1636993.
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Chen, Tseng-Chih y 陳增智. "An Improvement on the Efficiency of Network Authorization Mechanism". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/c45n9y.
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碩士世新大學
資訊管理學研究所(含碩專班)
96
A single sign-on and role-based authorization control can bring great benefits about integrating identity authentication and access control mechanisms. However, when we explore the system control functions, there are fewer simple and effective mechanisms controlling more detailed functions and authority. According to this truth, my study integrates single sign-on mechanism, RBAC access control mechanisms, file and directory of resource management mechanisms, access pre-loaded mechanisms and auditing mechanisms in order to construct a comprehensive information system group. Because web site's functions, files and directories are too many, controlling the authority efficiently becomes an important issue. The concept of file directory of resource framework, used class directory as the basis of cutting authority, set the authority of related functions easily and reduced the number of functions set by the role, minimizes the amount of data and manages detailed functions. Additionally, in order to enhance efficiency of giving and checking the user authorization, we primarily give the functions needed by users and add authority pre-loaded mechanism, which granted prior permission to common users, when providing authority. As a result, we can improve the using rate of delegating user's authority and reduce the number of times of delegating user's authority.
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Chou, Bo-Yin y 周伯胤. "Fast Mode Decision Mechanism for Coding Efficiency Improvement in H.264/AVC and SVC". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/ssm4ez.
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碩士國立中山大學
電機工程學系研究所
97
In order to speedup the encoding process of H.264/AVC and Scalable Video Coding (SVC), Temporal and Spatial Correlation-based Merging and Splitting (TSCMS) fast mode decision algorithm and Coded Block Pattern (CBP)-based fast mode decision algorithm are proposed in this thesis. TSCMS and CBP-based fast mode decision algorithms are applied to H.264/AVC and SVC, respectively. In TSCMS, Temporal Correlation (TC) is used to predict the Motion Vectors (MVs) of 8×8 blocks in each macroblock. In addition, the merging and splitting procedure is adopted to predict the motion vectors of other blocks. Afterwards, the spatial correlation is performed to merge 16×16 blocks instead of the conventional merge scheme. CBP value is the syntax used at each Macroblock (MB) header to indicate whether an MB contains residual information or not in CBP-based fast mode decision algorithm. The proposed algorithm can exclude the invalid modes for the mode prediction of the current MB in Enhancement Layer (EL) through the CBP values and MB modes of adjacent MBs in EL and the co-located Base Layer (BL) MB modes. Experimental results show that the proposed algorithms reduce computations significantly with negligible PSNR degradation and bit increase when compared to JM 12.3, JSVM 9.12, and the other existing methods.
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Jie, Su-Lin y 蘇林捷. "Power Efficiency Improvement of a Wavelength-preserved All Optical 2R Regeneration System in an SOA-based Optical Cross-gain Compression Mechanism". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/23931863856919016561.
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Carstens, Herman. "Improvements to longitudinal clean development mechanism sampling designs for lighting retrofit projects". Diss., 2014. http://hdl.handle.net/2263/42443.
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An improved model for reducing the cost of long-term monitoring in Clean Development Mechanism
(CDM) lighting retrofit projects is proposed. Cost-effective longitudinal sampling designs use the
minimum number of meters required to report yearly savings at the 90% confidence and 10% relative
precision level for duration of the project (up to 10 years) as stipulated by the CDM. Improvements
to the existing model include a new non-linear Compact Fluorescent Lamp population decay model
based on the results of the Polish Efficient Lighting Project, and a cumulative sampling function
modified to weight samples exponentially by recency. An economic model altering the cost function
to a nett present value calculation is also incorporated.
The search space for such sampling models are investigated and found to be discontinuous and
stepped, requiring a heuristic for optimisation; in this case the Genetic Algorithm was used. Assuming
an exponential smoothing rate of 0.25, an inflation rate of 6.44%, and an interest rate of 10%,
results show that sampling should be more evenly distributed over the study duration than is currently
considered optimal, and that the proposed improvements in model accuracy increase expected project
costs in nett present value terms by approximately 20%. A sensitivity analysis reveals that the expected
project cost is most sensitive to the reporting precision level, coefficient of variance, and reportingDissertation (MEng)--University of Pretoria, 2014.
gm2014
Electrical, Electronic and Computer Engineering
Unrestricted
Libros sobre el tema "Efficiency improvement mechanism"
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Cevelev, Aleksandr. Strategic development of railway transport logistics. ru: INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1194747.
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The monograph is devoted to the methodology of material and technical support of railway transport. According to the types of activities, the nature of the material and technical resources used, technologies, means and management systems, Russian railways belong to the category of high-tech industries that must have high quality and technical level, reliability and technological efficiency in operation. For this reason, the logistics system itself, both in structure and in the algorithm of the functions performed as a whole, needs a serious improvement in the quality of its work. The economic situation in Russia requires a revision of the principles and mechanisms of management based on the corporate model of supply chain management, focused on logistics knowledge. In the difficult economic conditions of the current decade, it is necessary to improve the quality of the supply organization of enterprises and structural divisions of railway transport, directly related to the implementation of the process approach, the advantage of which is a more detailed regulation of management actions and their mutual coordination. In order to increase the efficiency of its activities and develop the management system, Russian Railways is developing a lean production system aimed at further expanding the implementation of the principles of customer orientation, ideology and corporate culture.
At the present time, the solution of many issues is impossible without a cybernetic approach to the formulation of problems of material and technical support and logistics analysis of information technologies, to the implementation of the developed algorithms and models of development strategies and concepts for improving the business processes of the production system. The management strategy, or the general plan for the implementation of activities for the management of material resources, is based on a fundamental assessment of the alignment and correlation of forces and factors operating in the economic and political field, taking into account the impact on the specific form of the management strategy.
The materials will be useful to the heads and specialists of the directorates of the MTO, CDZs and can be used in the scientific research of bachelors, masters and postgraduates interested in the economics of railway transport and supply logistics.
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Das, Upasak, Amartya Paul y Mohit Sharma. Can information campaigns reduce last mile payment delays in public works programme? Evidence from a field experiment in India. 21a ed. UNU-WIDER, 2021. http://dx.doi.org/10.35188/unu-wider/2021/955-6.
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Does information dissemination among beneficiaries of welfare programmes mitigate their implementation failures? We present experimental evidence in the context of a rural public works programme in India, where we assess the impact of an intervention that involves dissemination of publicly available micro-level data on last mile delays in payment and programme uptake, along with a set of intermediate outcomes. The findings point to a substantial reduction in last mile payment delays along with improvements in awareness of basic provisions of the programme and process mechanisms while indicating a limited effect on uptake. However, we find a considerable increase in uptake in the subsequent period, which is potentially indicative of an ‘encouragement’ effect through the reduction in last mile delays. A comparatively higher impact on payment delay was found for deprived communities. The findings lay a platform for an innovative information campaign that can be used by government and civil society organizations as part of transparency measures to improve efficiency.
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Scott-Smith, Tom. On an Empty Stomach. Cornell University Press, 2020. http://dx.doi.org/10.7591/cornell/9781501748653.001.0001.
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This book examines the practical techniques humanitarians have used to manage and measure starvation, from Victorian “scientific” soup kitchens to space-age, high-protein foods. Tracing the evolution of these techniques since the start of the nineteenth century, the book argues that humanitarianism is not a simple story of progress and improvement, but rather is profoundly shaped by sociopolitical conditions. Aid is often presented as an apolitical and technical project, but the way humanitarians conceive and tackle human needs has always been deeply influenced by culture, politics, and society. These influences extend down to the most detailed mechanisms for measuring malnutrition and providing sustenance. As the book shows, over the past century, the humanitarian approach to hunger has redefined food as nutrients and hunger as a medical condition. Aid has become more individualized, medicalized, and rationalized, shaped by modernism in bureaucracy, commerce, and food technology. The book focuses on the gains and losses that result, examining the complex compromises that arise between efficiency of distribution and quality of care. It concludes that humanitarian groups have developed an approach to the empty stomach that is dependent on compact, commercially produced devices and is often paternalistic and culturally insensitive.
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Naji, Abdennasser. Total Quality Management in Education: Conditions for systemic improvement of the quality of learning outcomes. amazon, 2020. http://dx.doi.org/10.37870/979-8694752237.
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This book deals with the issue of the quality of education systems by examining the key factors that influence learning outcomes, and by highlighting in a systemic way the determinants of this quality. I have shown the importance of considering the quality of learning outcomes as the ultimate and unavoidable objective of any education system that aims to be efficient and effective. I reviewed the theoretical bases that concern the politics, approaches and mechanisms of quality management applied to education. I developed a model called Elmandjra, which tries to explain the influence links that can exist between the inputs, the processes and the outputs of an education system, and how they must function to improve the quality of the learning outcomes. To answer the problem of the book, I compared the proposed model to the reality of the Moroccan educational system based on a research methodology that combines discussion within a focus group, and analysis of statistical data and results of international surveys concerning the Moroccan education system. The results of the work made it possible to establish a model for the quality of education systems comprising nine criteria. They also generated 52 indicators which use will enable other researchers to apply the model to the institutional assessment of education systems. I ended my book by presenting the conclusions on the state of the Moroccan education system that the exploitation of the Elmandjra model made it possible to draw, as well as by recommendations to improve the quality of the Moroccan education system, which other countries can to be inspired to improve theirs.
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Mazer, Jeffrey y Mitchell M. Levy. Policies, bundles, and protocols in critical care. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199600830.003.0017.
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Recently, the medicine community has been driven to think about patient safety in new ways, and with this new found interest in patient safety, large health care systems and individual institutions have been forced to develop mechanisms to track and measure performance. There is ample evidence that physicians and systems can do better. The tools of this new craft include checklists, protocols, guidelines, and bundles. These tools help to decrease variability in care and enhance the translation of evidence-based medicine to bedside care. Ongoing measurement of both performance and clinical outcomes is central to this movement. This allows for rapid detection of both successes and possible unintended consequences associated with the rapid translation of evidence into practice. As hospitals and intensive care units (ICU) worldwide have embraced the field of quality improvement (QI), many lessons have been learned about the process. QI includes four essential phases—development, implementation, evaluation, and maintenance. Essential to the QI process and each of these QI phases is that the project must be tailored to each individual ICU and/or Institution. A one-size-fits-all project is less efficient, less effective, and at times unnecessary compare with a locally-driven process.
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Wojewodzic, Tomasz. Procesy dywestycji i dezagraryzacji w rolnictwie o rozdrobnionej strukturze agrarnej. Publishing House of the University of Agriculture in Krakow, 2017. http://dx.doi.org/10.15576/978-83-66602-31-1.
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The turn of the 20th and 21st centuries has been a very dynamic period of change in Poland and around the world; also a period of change in thinking about the economy and agriculture. The present work is a study of the decline, divestments and development of agriculture in the areas of fragmented farming structure. The reflections presented herein, upon the processes of the remodelling of agrarian structures, of divestments in farming, and disagrarisation, are mostly anchored in the achievements of the theory of spatial economy (land management), and the microeconomic theories of choice, including the theory of an agricultural holding (farm) and land rent theories. The work focuses on the economic issues of remodelling the agrarian structure, but due to the nature of the issues discussed herein, specifically in relation to family-owned farms, the social and environmental aspects also needed to be taken into account – in response to the need for a heterogeneous approach, which is increasingly stressed in economic sciences today. The main objective of the research was to diagnose and assess the scale and scope of the mechanisms and processes that inform the decline and growth of agricultural holdings in the areas with fragmented farming structure. The study covered the area comprising four regions (provinces) of south-eastern Poland, which – according to the FADN nomenclature – form the macro region of Małopolska and Pogórze. The study of subject literature has been enriched with an analysis of available statistics; data from the Farm Accountancy Data Network (FADN); information obtained from the Department of Programming and Reporting at the Agency for Restructuring and Modernisation of Agriculture; and author’s own research conducted among farm owners. The information thus obtained made it possible to: • Determine the theoretical premises for the spatial diversity of agriculture, and the role of small farms in the shaping of agrarian structure. • Adapt the concept of “divestment” for the description and analysis of the phenomena occurring in agriculture. • Indicate the role and importance of the processes of divestment and disagrarisation in the restructuring of agriculture. • Assess the natural, social and economic determinants of the process of restructuring agriculture in areas with fragmented farming structure. • Assess selected aspects of economic efficiency of agriculture in areas with fragmented farming structure, with the focus on small and micro farms. • Carry out an ex ante evaluation of the impact of agricultural policy instruments on the process of restructuring of agriculture in the macro region of Małopolska and Pogórze. • Identify the indicators of decline and fall, and barriers to the liquidation of farms. • Assess the relationship between the level of socio-economic development, the structure of farming, and the quality of agricultural production space in a given territorial unit, versus the intensity of the economic and production disagrarisation processes in agricultural holdings. • Propose targeted solutions conducive to the improvement of the farming structure in areas with a high framentation of agriculture. Observation of the processes occurring in agriculture, and the scientific theories created on the basis thereof, have shown that even the smallest farms have a chance to continue in existence, provided that we are able to positively verify their adaptation to the changing conditions in the environment. Carrying out farming activity is a prerequisite for implementing the economic, social and environmental functions associated with family farms. At the same time, based on the analyses performed, we need to assume that the advanced processes of the production and economic disagrarisation of agricultural holdings are to a greater extent determined by the anatomical features of agriculture, and by the natural conditions, than by the level of socio-economic development of the given territorial unit. In the current economic climate, the remodelling of the agrarian structure is only possible with the active participation of the institutions responsible for the creation of economic growth and agricultural policy development. It is extremely important from the point of view of environmental protection, and the viability of rural areas, to support small farms engaged in agricultural activities, and to introduce such instruments that will enable the replacement of an economic collapse with divestments, carried out in a planned manner, and allowing for thus released agricultural resources to find alternative application in units with a higher development potential. The area of theoretical research requiring further exploration includes the issues such as transactional costs of the liquidation of agricultural holdings, and the assessment of the economic effectiveness of conducting divestments.
Capítulos de libros sobre el tema "Efficiency improvement mechanism"
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Quilloy, Fergie Ann, Benedick Labaco, Carlos Casal y Shalabh Dixit. "Crop Establishment in Direct-Seeded Rice: Traits, Physiology, and Genetics". En Rice Improvement, 171–202. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-66530-2_6.
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AbstractThe changing climate and water availability strongly affect the current state of agricultural production. While the global temperature rises, the occurrence of extreme climatic conditions becomes erratic. This current scenario has driven the development of rice varieties and cultivation practices that require less water and favor mechanization. Although puddled transplanted rice has been more widely used in the past, direct seeding has been gaining popularity in recent years, especially due to its water- and labor-saving features. This technique allows full crop establishment from seeds that were directly sown in the field, thus avoiding puddling, transplanting, and maintaining standing water. Consequently, it offers promising positive environmental effects including decreasing the release of greenhouse gases and increasing water-use efficiency. Historically, rice varieties bred for transplanting are also used in direct seeding, which limits the maximum yield potential of field trials. The success of direct seeding relies strongly on the development of rice varieties with robust crop establishment. Anaerobic germination, seed longevity, and early seedling vigor are the key traits required to achieve this. This chapter expounds on the physiology, molecular mechanisms, genetics, and relevance of the enumerated traits for direct seeding. A brief discussion of breeding for rice varieties with improved germination under direct seeding is also provided.
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Sasirekha, G. V. K. y K. M. Gangaraju. "Efficient BER Improvement Mechanism for Wireless E1/E1 ATM Links". En Lecture Notes in Electrical Engineering, 41–51. Dordrecht: Springer Netherlands, 2009. http://dx.doi.org/10.1007/978-1-4020-9532-0_4.
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de Schutter, Kristof, Olivier Christiaens, Clauvis Nji Tizi Taning y Guy Smagghe. "Boosting dsRNA delivery in plant and insect cells with peptide- and polymer-based carriers: case-based current status and future perspectives." En RNAi for plant improvement and protection, 102–16. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789248890.0011.
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Abstract Since the discovery of this naturally occurring endogenous regulatory and defence mechanism, RNA interference (RNAi) has been exploited as a powerful tool for functional genomic research. In addition, it has evolved as a promising candidate for a sustainable, specific and ecofriendly strategy for pest management and plant improvement. A key element in this technology is the efficient delivery of dsRNAs into the pest or plant tissues. While several examples using transgenic plants expressing the dsRNAs have proved the potential of this technology, nontransgenic approaches are investigated as alternatives, allowing flexibility and circumventing technical limitations of the transgenic approach. However, the efficacy of environmental RNAi is affected by several barriers, such as extracellular degradation of the dsRNA, inefficient internalization of the dsRNA in the cell and low endosomal escape into the cytoplasm, resulting in variable or low RNAi responses. In the medical field, carrier systems are commonly used to enhance RNA delivery and these systems are being rapidly adopted by the agricultural industry. Using four case studies, this chapter demonstrates the potential of carriers to improve the RNAi response in pest control for aquatic-living mosquito larvae and RNAi-resilient Lepidoptera and to cross the plant cell wall, allowing efficient environmental RNAi in plants.
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de Schutter, Kristof, Olivier Christiaens, Clauvis Nji Tizi Taning y Guy Smagghe. "Boosting dsRNA delivery in plant and insect cells with peptide- and polymer-based carriers: case-based current status and future perspectives." En RNAi for plant improvement and protection, 102–16. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789248890.0102.
Texto completoResumen
Abstract Since the discovery of this naturally occurring endogenous regulatory and defence mechanism, RNA interference (RNAi) has been exploited as a powerful tool for functional genomic research. In addition, it has evolved as a promising candidate for a sustainable, specific and ecofriendly strategy for pest management and plant improvement. A key element in this technology is the efficient delivery of dsRNAs into the pest or plant tissues. While several examples using transgenic plants expressing the dsRNAs have proved the potential of this technology, nontransgenic approaches are investigated as alternatives, allowing flexibility and circumventing technical limitations of the transgenic approach. However, the efficacy of environmental RNAi is affected by several barriers, such as extracellular degradation of the dsRNA, inefficient internalization of the dsRNA in the cell and low endosomal escape into the cytoplasm, resulting in variable or low RNAi responses. In the medical field, carrier systems are commonly used to enhance RNA delivery and these systems are being rapidly adopted by the agricultural industry. Using four case studies, this chapter demonstrates the potential of carriers to improve the RNAi response in pest control for aquatic-living mosquito larvae and RNAi-resilient Lepidoptera and to cross the plant cell wall, allowing efficient environmental RNAi in plants.
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Plaček, Michal, František Ochrana, Milan Jan Půček y Juraj Nemec. "Conclusion and Public Policy Recommendation: Efficiency Improvement Through Managerial Approach and Accountability Mechanisms". En Fiscal Decentralization Reforms, 199–209. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-46758-6_11.
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Voigt, Claudia, Tony Wetzig, Jana Hubálková, Patrick Gehre, Nora Brachhold y Christos G. Aneziris. "Ceramic Filter Materials and Filter Structures with Active and Reactive Functional Pores for the Aluminum Melt Filtration". En Multifunctional Ceramic Filter Systems for Metal Melt Filtration, 57–82. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-40930-1_3.
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AbstractThe application of ceramic foam filters is state of the art in the casting of aluminum melt. Despite their industrial use since the 1960s, the filtration mechanisms are not fully understood. The Collaborative Research Center 920 investigated the influence of the filter surface chemistry and wetting between filter and melt on the filtration efficiency. The investigated filter surfaces based on Al2O3, MgAl2O4, 3Al2O3·2SiO2and TiO2 showed differences in the filtration efficiency and the wetting behavior whereby a good correlation for inclusions smaller than 110 µm was found–the larger the contact angle the higher the filtration efficiency. The results raised the question whether the intrinsic contact angle or the different roughness of the materials caused the changes in the filtration efficiency. A filtration trial at the Hydro pilot filtration line revealed a strong influence of the filter surface roughness on the filtration efficiency. A filter coated with Nano-Al2O3, with a divergent intrinsic contact angle compared to be Al2O3 reference filter, showed no improvement of the filtration behavior indicating no influence of the intrinsic contact angle on the filtration.
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Hayes, R. C., M. T. Abberton y J. A. Lovatt. "Mechanisms Utilised Within the IBERS Diploid Lolium perenne L. Forage Grass Breeding Programmes to Improve Rumen Nitrogen Use Efficiency". En Breeding strategies for sustainable forage and turf grass improvement, 47–53. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-4555-1_5.
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Wang, Bibo, Yu Chen, Hongliang Gu, Jian Yang y Tan Zhao. "Two Energy-Efficient, Timesaving Improvement Mechanisms of Network Reprogramming in Wireless Sensor Network". En Embedded Software and Systems, 473–83. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/11599555_45.
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Brackmann, Lukas, Arne Röttger, Hoang-Giang Bui, Sahir Butt, Golnaz Hoormazdi, Abdiel Ramon Leon Bal, Sebastian Priebe et al. "Excavation Simulations and Cutting Tool Wear". En Interaction Modeling in Mechanized Tunneling, 93–164. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-24066-9_3.
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AbstractThe mechanized tunnel construction is carried out by tunnel boring machines, in which the soil in front of the working face is removed, and the tunnel lining is carried out with shotcrete or the setting of segments and their back injection. Advancements in this field aim towards increase of the excavation efficiency and increase of the tool lifetime, especially in rock-dominated grounds. The latter is achieved by understanding the wear mechanisms abrasion and surface-fatigue, and by knowledge of the microstructure-property relation of the utilized materials. Improvements for tool concepts are derived, based on experiments and simulations. A key parameter towards efficient rock excavation is the shape of the cutting edge of the utilized disc cutters. Sharp cutting edges have proven to generate higher rock excavation rates compared to blunt ones. The compressive strength of the utilized steel has to be high, to inhibit plastic deformation and thereby to maintain sharp cutting edges. This requirement competes with the demand for toughness, which is necessary to avoid crack-growth in the case of cyclic loading. Solutions for this contradiction lie in specially designed multiphase microstructures, containing both hard particles and ductile microstructural constituents. Besides adapting the alloying concept, these required microstructures and the associated properties can be adjusted by specific heat-treatments.
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Park, Byungjoo, In Huh y Haniph Latchman. "Performance Improvement of TCP with an Efficient Contention Window Control Mechanism (ECWC) in IEEE 802.11 Based Multi-hop Wireless Networks". En Ad-Hoc, Mobile, and Wireless Networks, 365–75. Berlin, Heidelberg: Springer Berlin Heidelberg, 2006. http://dx.doi.org/10.1007/11814764_30.
Texto completoActas de conferencias sobre el tema "Efficiency improvement mechanism"
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Yang, Wenying, Fansong Meng y Daoyi Wu. "Parametric Sensitivity Analysis and Efficiency Improvement of Electromagnetic Repulsion Mechanism Based on Orthogonal Experiment Design". En 2024 IEEE International Magnetic Conference - Short Papers (INTERMAG Short Papers). IEEE, 2024. http://dx.doi.org/10.1109/intermagshortpapers61879.2024.10577071.
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Muramatsu, N., H. Ando, M. Takaki, H. Matsumoto y Y. Kubouchi. "Gripping Efficiency of Gripping Mechanism Using Buckling Phenomenon of Long Column". En ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13631.
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In the development of miniature opening and closing mechanism, piezoelectric element has been used as its actuator. This mechanism, however, tends to become larger and complicated as it needs a mechanism for displacement enlargement because of the infinitesimal output displacement. Therefore, an attempt applying buckling phenomenon of long column to the opening and closing mechanism of finger has been made. An elastic member with a long strip shape was bent in the shape of M character, both ends fixed and reciprocating translational drive was imparted to the V-shaped common portion at the center. As a result, a simple miniature gripper with large rate of bending displacement at the finger tip to a translational displacement at the center, namely the enlargement rate of the displacement, has been developed. In this study, in addition to the element technology development for product, such improvements as increasing of the rate of gripping force to driving tensile force on the finger, that is, gripping efficiency were aimed. The results obtained are as follows. (1) Hinge joints on supporting portions at both ends or the mid common portion of the fingers decrease the driving tensile force beginning to grip. They, however, little contribute to the improvement of the gripping efficiency. (2) Crossing an operating member at the center in the shape of × character so as to enlarge an angle of the operating members to the finger increases the gripping efficiency. The enlargement rate of the displacement, however, decreases, so that the angle should be decided based on the object. (3) Free support of an intermediate portion on a lateral surface of the finger allows the change of the gripping efficiency. When bending deformation outside at the center in length of the finger is restrained, the gripping efficiency increases by about 2 times.
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Chunbao, Liu, Chai Bosen, Liu Changsuo y Ma Wenxing. "Research on mechanism of drag reduction and efficiency improvement of hydrodynamic torque converter with bionic non-smooth surfaces". En 2015 International Conference on Fluid Power and Mechatronics (FPM). IEEE, 2015. http://dx.doi.org/10.1109/fpm.2015.7337333.
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Komp, Dominik, Sumeet Kumar, Amine Abdelmoula, Manfred Hajek y Juergen Rauleder. "Investigation of Active Rotor Design and Control for Performance Improvement". En Vertical Flight Society 75th Annual Forum & Technology Display. The Vertical Flight Society, 2019. http://dx.doi.org/10.4050/f-0075-2019-14530.
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A computational investigation was conducted to identify the optimal performance of a rotor with an active camber morphing mechanism using up to twice-per-revolution (2P) control input. Using rotor comprehensive analysis with an elastic blade model and a free vortex wake for the aerodynamics model to ensure computational efficiency, a parametric study of design and control variables was carried out to identify their influence on rotor performance. The same computational framework was used to obtain optimal control inputs that led to best performance using 2P individual blade control (IBC) via pitch-link inputs and 2P active twist control. The relative potential of the three active mechanisms to improve rotor performance was studied and compared. A level flight condition at μ = 0.3 and CT /σ = 0.089 was used throughout this investigation. IBC or active twist both yielded maximum performance improvements of 1.8% in terms of power reduction. Optimal isolated 1P and 2P active camber actuation resulted in performance improvements of 3.6% and 3.1%, respectively. Using the best combination of geometric design and optimal superimposed 1P+2P actuation, a rotor power reduction of 4.4% was obtained. Overall, the rotor performance gains obtained using each active rotor mechanism that was investigated were attributed to a more uniform distribution of thrust over the rotor disk.
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Saxena, Samveg, Iván Dario Bedoya, Nihar Shah y Amol Phadke. "Understanding Loss Mechanisms and Identifying Areas of Improvement for HCCI Engines Using Detailed Exergy Analysis". En ASME 2012 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/icef2012-92052.
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This paper presents a detailed exergy analysis of homogeneous charge compression ignition (HCCI) engines, including a crank-angle resolved breakdown of mixture exergy and exergy destruction. Exergy analysis is applied to a multi-zone HCCI simulation including detailed chemical kinetics. The HCCI simulation is validated against engine experiments for ethanol-fueled operation. The exergy analysis quantifies the relative importance of different loss mechanisms within HCCI engines over a range of engine operating conditions. Specifically, four loss mechanisms are studied for their relative impact on exergy losses, including 1) the irreversible combustion process (16.4–21.5%), 2) physical exergy lost to exhaust gases (12.0–18.7%), 3) heat losses (3.9–17.1%), and 4) chemical exergy lost to incomplete combustion (4.7–37.8%). The trends in each loss mechanism are studied in relation to changes in intake pressure, equivalence ratio, and engine speed as these parameters are directly used to vary engine power output. This exergy analysis methodology is proposed as a tool to inform research and design processes, particularly by identifying the relative importance of each loss mechanism in determining engine operating efficiency.
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Hah, Chunill. "Stall Margin Improvement in a Transonic Compressor With a Casing Treatment: Flow Mechanism". En ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-83363.
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Abstract A compressor casing treatment with circumferential casing grooves (CCGs) is studied in detail. The primary objective of the current paper is to unearth the main driving fluid mechanism that changes the stall margin in a transonic compressor with CCGs. Large Eddy Simulation (LES) is applied to calculate the transonic compressor flow fields with and without CCGs. Detailed comparisons between measured and computed flow fields show that changes in flow structures due to CCGs are very well represented with LES. The measured data show that flow blockage generation in the tip gap area is reduced significantly when CCGs are applied, which delays compressor stall onset. Calculated flow fields with and without CCGs are examined to understand how the blockage generation is reduced with CCGs. Tip leakage flow typically travels upstream, opposite to the incoming main flow. When CCGs are applied on the compressor casing, part of the tip leakage flow goes into the grooves and is later reinjected into the main flow passage. Therefore, CCGs modify the collision between the incoming main passage flow and the tip leakage flow. Two main aspects of the change of tip leakage flow due to CCGs are examined in the present study. The first aspect is whether the total mass flow through the tip gap changes substantially with CCGs. The second aspect is whether changes in the collision and mixing of the incoming main passage flow and the tip leakage flow due to CCGs substantially affect blockage generation. The present investigation shows that CCGs reduce the mass flow through the tip gap by about 16 % near the stall-condition. Calculated flow fields show that most of this reduction of tip leakage flow occurs near the CCGs. Reinjected flow from the CCGs pushes the tip leakage flow radially inward below the casing and changes how the tip leakage flow collides with the incoming main passage flow. However, detailed examination of the calculated flow in the tip region shows that the reinjected flow does not contribute to the reduction of the overall blockage generation. The primary driver reducing blockage generation with CCGs is the reduction of overall mass flow rate through the tip gap. It has been thought that circumferential grooves always incur small additional losses near the design condition due to mixing between the flow exiting the grooves and the main flow, in addition to an increased wetted area. In the present investigation, measurements show such a decrease in efficiency with CCGs, although the difference in efficiency is within the measurement uncertainty. Results from the LES simulation at the design condition with CCGs show that the tip leakage vortex (TLV) is pulled toward the blade suction side and double leakage flow is eliminated. The result is that the simulated efficiencies with and without CCGs are almost the same.
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Zhao, Wei, Qingjun Zhao, Xiuming Sui, Weiwei Luo y Jianzhong Xu. "Numerical Investigation on Loss Mechanism and Performance Improvement for a Zero Inlet Swirl Turbine Rotor". En ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-63220.
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A zero inlet swirl turbine rotor (ZISTR) is originally presented as the first stage in a multistage vaneless counter-rotating turbine (MVCT), which only consists of 4 rotors without any vanes. The vanes upstream of a ZISTR are removed to reduce the turbine weight and length, as well as the viscous losses and coolants associated with vanes. However, due to the lack of inlet swirl the stagger angles for ZISTR blade profiles are high and the blade deflections are very small, resulting in almost straight cambers and very thin airfoils. The motivation of this paper is to reveal the overall performance and key loss sources of a ZISTR associated with its special blade profile, and provide corresponding optimization approaches for its practical usages. The 3D viscous numerical results show that the wake, the suction side trailing edge shock and the tip leakage flow have substantial influence on the rotor performance. To optimize the performance of a ZISTR, reducing blade solidity is proposed to decrease the viscous and shock losses by increasing the portion of the inviscid mainstream. Leaned blade is also presented to restrict the tip leakage flow by adjusting the axial position of stagnation points on the blade profile, obtaining an increase in efficiency of 0.9%. The off-design performance of the optimized rotor is also presented to show the effect of the blade lean on efficiency at various rotating speeds and back pressures.
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Smith, Amy J. y Keshab K. Dwivedy. "An Improvement in the Code Evaluation of Flawed Pipes". En ASME 2007 Pressure Vessels and Piping Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/pvp2007-26205.
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ASME Code Section XI Nonmandatory Appendix C [1] formalized evaluation of flaws in piping for justification of continued service of piping components with an identified crack-like flaw. The revision of this appendix in 2004 was a significant improvement in the evaluation methodology for both flawed austenitic stainless steel and ferritic steel pipe depending upon the failure mode governed by limit load (fully plastic), elastic-plastic fracture mechanics, or linear elastic fracture mechanics. The appendix also provides a screening procedure to determine failure mechanism and a procedure for flaw modeling based on the estimated flaw size at the end of a specified evaluation period. The purpose of this paper is to propose an improvement to the limit load method applicable to screened-in carbon steel, wrought stainless steel base material, stainless steel weld material with nonflux weld, and cast products in which the ferrite content is less than twenty percent. In addition, changes in the formulation are proposed to extend the methodology to non-crack-like flaws. Both crack-like and non-crack-like circumferential flaws in the piping are analyzed to simplify formulation for flaw evaluation. The paper concludes that the proposed formulation improves efficiency of the application of Appendix C methodology for crack-like flaw and non-crack-like flaw evaluations.
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Arakelyan, Vigen y Yang Zhang. "Improvement of the Balancing Accuracy in Gravity Compensators Based on the Inverted Slider Crank Mechanism". En ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-85361.
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The static balancing of mechanical systems is an important issue because it allows significant reduction of torques. However the literature review shows that in many cases the gravity balancing of mechanical systems is carried out by neglecting the masses of auxiliary links associated to the principal mechanism. For many balancing schemes it is the source of errors. This paper deals with an improved solution for gravity compensators based on the inverted slider crank mechanism considering the masses of the rocker and the spring. For this purpose, the torques due to auxiliary links are determined. Then, they are introduced into the balancing equation for minimization of the residual unbalance. In this way, a more accurate balancing of gravity compensators is achieved. The efficiency of the suggested approach is illustrated by numerical simulations.
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Griffin, Lisa W., Frank W. Huber y Om P. Sharma. "Performance Improvement Through Indexing of Turbine Airfoils: Part 2 — Numerical Simulation". En ASME 1995 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/95-gt-028.
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An experimental/analytical study has been conducted to determine the performance improvements achievable by circumferentially indexing succeeding rows of turbine stator airfoils. A series of tests was conducted to experimentally investigate stator wake clocking effects on the performance of the space shuttle main engine (SSME) alternate turbopump development (ATD) fuel turbine test article (TTA). The results from this study indicate that significant increases in stage efficiency can be attained through application of this airfoil clocking concept. Details of the experiment and its results are documented in part 1 of this paper. In order to gain insight into the mechanisms of the performance improvement, extensive computational fluid dynamics (CFD) simulations were executed. The subject of the present paper is the initial results from the CFD investigation of the configurations and conditions detailed in part 1 of the paper. To characterize the aerodynamic environments in the experimental test series, two-dimensional (2D), time-accurate, multistage, viscous analyses were performed at the TTA midspan. Computational analyses for five different circumferential positions of the first stage stator have been completed. Details of the computational procedure and the results are presented. The analytical results verify the experimentally demonstrated performance improvement and are compared with data whenever possible. Predictions of time-averaged turbine efficiencies as well as gas conditions throughout the flow field are presented. An initial understanding of the turbine performance improvement mechanism based on the results from this investigation is described.
Informes sobre el tema "Efficiency improvement mechanism"
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Yahav, Shlomo, John McMurtry y Isaac Plavnik. Thermotolerance Acquisition in Broiler Chickens by Temperature Conditioning Early in Life. United States Department of Agriculture, 1998. http://dx.doi.org/10.32747/1998.7580676.bard.
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The research on thermotolerance acquisition in broiler chickens by temperature conditioning early in life was focused on the following objectives: a. To determine the optimal timing and temperature for inducing the thermotolerance, conditioning processes and to define its duration during the first week of life in the broiler chick. b. To investigate the response of skeletal muscle tissue and the gastrointestinal tract to thermal conditioning. This objective was added during the research, to understand the mechanisms related to compensatory growth. c. To evaluate the effect of early thermo conditioning on thermoregulation (heat production and heat dissipation) during 3 phases: (1) conditioning, (2) compensatory growth, (3) heat challenge. d. To investigate how induction of improved thermotolerance impacts on metabolic fuel and the hormones regulating growth and metabolism. Recent decades have seen significant development in the genetic selection of the meat-type fowl (i.e., broiler chickens); leading to rapid growth and increased feed efficiency, providing the poultry industry with heavy chickens in relatively short growth periods. Such development necessitates parallel increases in the size of visceral systems such as the cardiovascular and the respiratory ones. However, inferior development of such major systems has led to a relatively low capability to balance energy expenditure under extreme conditions. Thus, acute exposure of chickens to extreme conditions (i.e., heat spells) has resulted in major economic losses. Birds are homeotherms, and as such, they are able to maintain their body temperature within a narrow range. To sustain thermal tolerance and avoid the deleterious consequences of thermal stresses, a direct response is elicited: the rapid thermal shock response - thermal conditioning. This technique of temperature conditioning takes advantage of the immaturity of the temperature regulation mechanism in young chicks during their first week of life. Development of this mechanism involves sympathetic neural activity, integration of thermal infom1ation in the hypothalamus, and buildup of the body-to-brain temperature difference, so that the potential for thermotolerance can be incorporated into the developing thermoregulation mechanisms. Thermal conditioning is a unique management tool, which most likely involves hypothalamic them1oregulatory threshold changes that enable chickens, within certain limits, to cope with acute exposure to unexpected hot spells. Short-tem1 exposure to heat stress during the first week of life (37.5+1°C; 70-80% rh; for 24 h at 3 days of age) resulted in growth retardation followed immediately by compensatory growth" which resulted in complete compensation for the loss of weight gain, so that the conditioned chickens achieved higher body weight than that of the controls at 42 days of age. The compensatory growth was partially explained by its dramatic positive effect on the proliferation of muscle satellite cells which are necessary for further muscle hypertrophy. By its significant effect of the morphology and functioning of the gastrointestinal tract during and after using thermal conditioning. The significant effect of thermal conditioning on the chicken thermoregulation was found to be associated with a reduction in heat production and evaporative heat loss, and with an increase in sensible heat loss. It was further accompanied by changes in hormones regulating growth and metabolism These physiological responses may result from possible alterations in PO/AH gene expression patterns (14-3-3e), suggesting a more efficient mechanism to cope with heat stress. Understanding the physiological mechanisms behind thermal conditioning step us forward to elucidate the molecular mechanism behind the PO/AH response, and response of other major organs. The thermal conditioning technique is used now in many countries including Israel, South Korea, Australia, France" Ecuador, China and some places in the USA. The improvement in growth perfom1ance (50-190 g/chicken) and thermotolerance as a result of postnatal thermal conditioning, may initiate a dramatic improvement in the economy of broiler's production.
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Zilberman, David y Eithan Hochman. Price Evaluation and Allocation of Water under Alternative Water Rights Systems. United States Department of Agriculture, julio de 1992. http://dx.doi.org/10.32747/1992.7561062.bard.
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This project developed conceptual and empirical frameworks to analyze the water management politics as water scarcity increases. The analyses showed that increased scarcity will tend to encourage a transition from systems in which water is allocated administratively to water trading. However, transaction costs and political economy considerations placed barriers on the introduction of markets. The recent droughts - both in Israel and California were shown to cause an increase in water use efficiency by adoption of modern technologies and improvement of water conveyance systems. The drought led to institutional innovations and an increased reliance on trading as mechanisms for water allocation. Case studies from both countries demonstrate that reducing barriers to water trading and increasing farmers' flexibility in exchange of water will lead to efficient outcomes and much better uses of existing water resources.
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Ferdaus, Md Meftahul, Mahdi Abdelguerfi, Kendall Niles, Ken Pathak y Joe Tom. Widened attention-enhanced atrous convolutional network for efficient embedded vision applications under resource constraints. Engineer Research and Development Center (U.S.), noviembre de 2024. http://dx.doi.org/10.21079/11681/49459.
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Onboard image analysis enables real-time autonomous capabilities for unmanned platforms including aerial, ground, and aquatic drones. Performing classification on embedded systems, rather than transmitting data, allows rapid perception and decision-making critical for time-sensitive applications such as search and rescue, hazardous environment exploration, and military operations. To fully capitalize on these systems’ potential, specialized deep learning solutions are needed that balance accuracy and computational efficiency for time-sensitive inference. This article introduces the widened attention-enhanced atrous convolution-based efficient network (WACEfNet), a new convolutional neural network designed specifically for real-time visual classification challenges using resource-constrained embedded devices. WACEfNet builds on EfficientNet and integrates innovative width-wise feature processing, atrous convolutions, and attention modules to improve representational power without excessive over-head. Extensive benchmarking confirms state-of-the-art performance from WACEfNet for aerial imaging applications while remaining suitable for embedded deployment. The improvements in accuracy and speed demonstrate the potential of customized deep learning advancements to unlock new capabilities for unmanned aerial vehicles and related embedded systems with tight size, weight, and power constraints. This research offers an optimized framework, combining widened residual learning and attention mechanisms, to meet the unique demands of high-fidelity real-time analytics across a variety of embedded perception paradigms.
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Defoort, Willson y Olsen. L51849 Performance Evaluation of Exhaust Catalysts During the Initial Aging on Large Industrial Engines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), junio de 2001. http://dx.doi.org/10.55274/r0011213.
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An investigation of catalyst performance during the initial aging process, providing insight into the deactivation rate of the catalyst and assisting in predicting the operational lifetime of the catalyst was preformed. The information gained through the test program provides a mechanism to assist in developing new technologies geared at reducing engine emission while providing improvements in efficiency, reliability, and operability for the aging industrial reciprocating engine fleet. Two natural gas lean burn engines, a 2-stroke, large bore slow speed and a 4-stroke medium bore medium speed, were operated at pre-determined conditions in conjunction with an oxidation catalyst. The aging process of the catalysts was observed. The research concluded that the catalyst performance is much lower than anticipated,particularly in relation to the aging process. During the aging process for the large bore 2-stroke engine (about 200 hours) the catalyst efficiency drops from 95% to 80% for CO and from 75% to 45% for CH2O. Results for the medium bore 4-stroke engine are better as a result of nearly 200°F higher catalyst temperatures. During aging (approximately 150 hours) the catalyst efficiencies are reduced from 99.2 to 97.7% for CO and from undetectable post catalyst levels (essentially 100% removal) to 67% for CH2O.
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Yahav, Shlomo, John Brake y Noam Meiri. Development of Strategic Pre-Natal Cycling Thermal Treatments to Improve Livability and Productivity of Heavy Broilers. United States Department of Agriculture, diciembre de 2013. http://dx.doi.org/10.32747/2013.7593395.bard.
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The necessity to improve broiler thermotolerance and live performance led to the following hypothesis: Appropriate comprehensive incubation treatments that include significant temperature management changes will promote angiogenesis and will improve acquisition of thermotolerance and carcass quality of heavy broilers through epigenetic adaptation. It was based on the following questions: 1. Can TM during embryogenesis of broilers induce a longer-lasting thermoregulatory memory (up to marketing age of 10 wk) that will improve acquisition of thermotolerance as well as increased breast meat yield in heavy broilers? 2. The improved sensible heat loss (SHL) suggests an improved peripheral vasodilation process. Does elevated temperature during incubation affect vasculogenesis and angiogenesis processes in the chick embryo? Will such create subsequent advantages for heavy broilers coping with adverse hot conditions? 3. What are the changes that occur in the PO/AH that induce the changes in the threshold response for heat production/heat loss based on the concept of epigenetic temperature adaptation? The original objectives of this study were as follow: a. to assess the improvement of thermotolerance efficiency and carcass quality of heavy broilers (~4 kg); b. toimproveperipheral vascularization and angiogenesis that improve sensible heat loss (SHL); c. to study the changes in the PO/AH thermoregulatory response for heat production/losscaused by modulating incubation temperature. To reach the goals: a. the effect of TM on performance and thermotolerance of broilers reared to 10 wk of age was studied. b. the effect of preincubation heating with an elevated temperature during the 1ˢᵗ 3 to 5 d of incubation in the presence of modified fresh air flow coupled with changes in turning frequency was elucidated; c.the effect of elevated temperature on vasculogenesis and angiogenesis was determined using in ovo and whole embryo chick culture as well as HIF-1α VEGF-α2 VEGF-R, FGF-2, and Gelatinase A (MMP2) gene expression. The effects on peripheral blood system of post-hatch chicks was determined with an infrared thermal imaging technique; c. the expression of BDNF was determined during the development of the thermal control set-point in the preoptic anterior hypothalamus (PO/AH). Background to the topic: Rapid growth rate has presented broiler chickens with seriousdifficulties when called upon to efficiently thermoregulate in hot environmental conditions. Being homeotherms, birds are able to maintain their body temperature (Tb) within a narrow range. An increase in Tb above the regulated range, as a result of exposure to environmental conditions and/or excessive metabolic heat production that often characterize broiler chickens, may lead to a potentially lethal cascade of irreversible thermoregulatory events. Exposure to temperature fluctuations during the perinatal period has been shown to lead to epigenetic temperature adaptation. The mechanism for this adaptation was based on the assumption that environmental factors, especially ambient temperature, have a strong influence on the determination of the “set-point” for physiological control systems during “critical developmental phases.” Recently, Piestunet al. (2008) demonstrated for the first time that TM (an elevated incubation temperature of 39.5°C for 12 h/d from E7 to E16) during the development/maturation of the hypothalamic-hypophyseal-thyroid axis (thermoregulation) and the hypothalamic-hypophyseal-adrenal axis (stress) significantly improved the thermotolerance and performance of broilers at 35 d of age. These phenomena raised two questions that were addressed in this project: 1. was it possible to detect changes leading to the determination of the “set point”; 2. Did TM have a similar long lasting effect (up to 70 d of age)? 3. Did other TM combinations (pre-heating and heating during the 1ˢᵗ 3 to 5 d of incubation) coupled with changes in turning frequency have any performance effect? The improved thermotolerance resulted mainly from an efficient capacity to reduce heat production and the level of stress that coincided with an increase in SHL (Piestunet al., 2008; 2009). The increase in SHL (Piestunet al., 2009) suggested an additional positive effect of TM on vasculogenesis and angiogensis. 4. In order to sustain or even improve broiler performance, TM during the period of the chorioallantoic membrane development was thought to increase vasculogenesis and angiogenesis providing better vasodilatation and by that SHL post-hatch.
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Tao, Yang, Amos Mizrach, Victor Alchanatis, Nachshon Shamir y Tom Porter. Automated imaging broiler chicksexing for gender-specific and efficient production. United States Department of Agriculture, diciembre de 2014. http://dx.doi.org/10.32747/2014.7594391.bard.
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Extending the previous two years of research results (Mizarch, et al, 2012, Tao, 2011, 2012), the third year’s efforts in both Maryland and Israel were directed towards the engineering of the system. The activities included the robust chick handling and its conveyor system development, optical system improvement, online dynamic motion imaging of chicks, multi-image sequence optimal feather extraction and detection, and pattern recognition. Mechanical System Engineering The third model of the mechanical chick handling system with high-speed imaging system was built as shown in Fig. 1. This system has the improved chick holding cups and motion mechanisms that enable chicks to open wings through the view section. The mechanical system has achieved the speed of 4 chicks per second which exceeds the design specs of 3 chicks per second. In the center of the conveyor, a high-speed camera with UV sensitive optical system, shown in Fig.2, was installed that captures chick images at multiple frames (45 images and system selectable) when the chick passing through the view area. Through intensive discussions and efforts, the PIs of Maryland and ARO have created the protocol of joint hardware and software that uses sequential images of chick in its fall motion to capture opening wings and extract the optimal opening positions. This approached enables the reliable feather feature extraction in dynamic motion and pattern recognition. Improving of Chick Wing Deployment The mechanical system for chick conveying and especially the section that cause chicks to deploy their wings wide open under the fast video camera and the UV light was investigated along the third study year. As a natural behavior, chicks tend to deploy their wings as a mean of balancing their body when a sudden change in the vertical movement was applied. In the latest two years, this was achieved by causing the chicks to move in a free fall, in the earth gravity (g) along short vertical distance. The chicks have always tended to deploy their wing but not always in wide horizontal open situation. Such position is requested in order to get successful image under the video camera. Besides, the cells with checks bumped suddenly at the end of the free falling path. That caused the chicks legs to collapse inside the cells and the image of wing become bluer. For improving the movement and preventing the chick legs from collapsing, a slowing down mechanism was design and tested. This was done by installing of plastic block, that was printed in a predesign variable slope (Fig. 3) at the end of the path of falling cells (Fig.4). The cells are moving down in variable velocity according the block slope and achieve zero velocity at the end of the path. The slop was design in a way that the deacceleration become 0.8g instead the free fall gravity (g) without presence of the block. The tests showed better deployment and wider chick's wing opening as well as better balance along the movement. Design of additional sizes of block slops is under investigation. Slops that create accelerations of 0.7g, 0.9g, and variable accelerations are designed for improving movement path and images.
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Dudareva, Natalia, Alexander Vainstein, Eran Pichersky y David Weiss. Integrating biochemical and genomic approaches to elucidate C6-C2 volatile production: improvement of floral scent and fruit aroma. United States Department of Agriculture, septiembre de 2007. http://dx.doi.org/10.32747/2007.7696514.bard.
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The specific objectives of approved proposal include to: 1. Elucidate the C6-C2 biochemical pathways leading to the biosynthesis of phenylacetaldehyde, phenylethyl alcohol and phenylethyl acetate in floral tissues of ornamentally important plants, pefunia and roses. 2. Isolate and characterrze genes responsible for the production of these C6-C2 compounds and those involved in the regulation of the pathway using genomic and transcriptomic tools. 3. Determine whether altering the expression of key genes of this pathway can result in changing the aroma characteristics of flowers. Aldehydes are intermediates in a variety of biochemical pathways including those involved in the metabolism of carbohydrates, vitamins, steroids, amino acids, benzylisoquinoline alkaloids, hormones, and lipids. In plants they are also synthesized in response to environmental stresses such as salinity, cold, and heat shock or as flavors and aromas in fruits and flowers. Phenylacetaldehyde along with 2-phenylethanol and its acetate ester, are important scent compounds in numerous flowers, including petunias and roses. However, little is known about the biosynthesis of these volatile compounds in plants. We have shown that the formation PHA and 2-phenylethanol from Phe does not occur via trans-cinnamic acid and instead competes with the key enzyme of phenypropanoid metabolism Pheammonia-lyase (PAL) for Phe utilization. Using functional genomic approach and comparative gene expression profiling, we have isolated and characterized a novel enzyme from petunia and rose flowers that catalyzes the formation of the Ca-Czcompound phenylacetaldehyde (PHA) from L-phenylalanine (Phe) by the removal of both the carboxyl and amino groups. This enzyme, designated as phenylacetaldehyde synthases (PAAS), is a bifunctional enzyme that catalyzes the unprecedented efficient coupling of phenylalanine decarboxylation to oxidation, generating phenylacetaldehyde, CO2, ammonia, and hydrogen peroxide in stoichiometric amounts. Down-regulation of PAAS expression via RNA interference-based (RNAi) technology in petunia resulted in no PHA emission when compared with controls. These plants also produced no 2-phenylethanol, supporting our conclusion that PHA is a precursor of 2-phenylethanol. To understand the regulation of scent formation in plants we have also generated transgenic petunia and tobacco plants expressing the rose alcohol acetyltransferase (RhAAT) gene under the control of a CaMV-35S promoter. Although the preferred substrate of RhAAT in vitro is geraniol, in transgenic petunia flowers, it used phenylethyl alcohol and benzyl alcohol to produce the corresponding acetate esters, not generated by control flowers. These results strongly point to the dependence of volatile production on substrate availability. Analysis of the diurnal regulation of scent production in rose flowers revealed that although the daily emission of most scent compounds is synchronized, various independently evolved mechanisms control the production, accumulation and release of different volatiles. This research resulted in a fundamental discovery of biochemical pathway, enzymes and genes involved in biosynthesis of C6-C2s compounds, and provided the knowledge for future engineering plants for improved scent quality.
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Glazer, Itamar, Alice Churchill, Galina Gindin y Michael Samish. Genomic and Organismal Studies to Elucidate the Mechanisms of Infectivity of Entomopathogenic Fungi to Ticks. United States Department of Agriculture, enero de 2013. http://dx.doi.org/10.32747/2013.7593382.bard.
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The overall goal of this research was to elucidate the factors affecting early development of Metarhizium spp. (previously named M. anisopliae) on ticks or tick cuticle extracts and the molecular basis of these early infection processes. The original objectives were: 1. Characterize the pre-penetration events (adhesion, germination and appressorium formation) of spores of M. anisopliae strains with high or low virulence during tick infection. 2. Create GFP-expressing strains of M. anisopliae tick pathogens having high and low virulence to compare their progress of infection by microscopy. 3. Use microarray analyses, primarily with existing M. anisopliae EST sequences in GenBank, to identify and characterize fungal genes whose expression is regulated in response to host cuticle extracts. Objective 3 was later modified (as approved by BARD) to use RNAseq to characterize the early stages of fungal gene expression during infection of intact host cuticles. This new method provides a massively larger and more informative dataset and allows us to take advantage of a) recently published genomes of Metarhizium robertsii and M. acridum for RNAseq data analysis, and b) newly developed and highly efficient cDNA sequencing technologies that are relatively low cost and, therefore, allow deep sequencing of multiple transcriptome samples. We examined pre-penetration and penetration events that differentiate high and low virulence strains of Metarhizium spp., focusing on spore adhesion, germination, appressorium formation, and penetration of tick integuments. Initiation of fungal infection was compared on susceptible and resistant tick species at different tick developmental stages. In vitro studies comparing the effects of protein and fatty acid profiles from tick cuticle extracts demonstrated that resistant tick cuticles contain higher concentrations of specific lipids that inhibit fungal development than do susceptible tick cuticles, suggesting one mechanism of Ixodidae resistance to fungal entomopathogens (Objective 1). We used molecular markers to determine that the three M. anisopliae strains from Israel that we studied actually were three distinct species. M. brunneum is highly virulent against the tick Rhipicephalus annulatus, M. pingshaense and M. robertsii are intermediate in virulence, and M. majus is of low virulence. We transformed all four Metarhizium species to express GFP and used them in pathogenicity assays against diverse tick species. Key findings were that a) resistant ticks inhibit Metarhizium infection prior to hemocoel invasion by reducing fungal viability on the cuticle surface (Objective 2), as was supported by the in vitro studies of Objective 1, and b) Metarhizium kills susceptible ticks after cuticle penetration but prior to hemocoel colonization. Transcriptome studies of the most virulent species, M. brunneum, are in progress and include analyses of ungerminated conidia and conidia germination and development on a low nutrient medium or on susceptible R. annulatus exoskeleton (Objective 3). We anticipate these studies will contribute to identifying fungal genetic factors that increase virulence and speed of kill and may help reveal tick chemistries that could be included in biocontrol formulations to increase efficacy. Methodologies developed to screen tick cuticle extracts for ability to support conidia germination and development may help in the selection of wild fungi with increased virulence against resistant ticks. The overall knowledge gained should contribute not only to the improvement of tick control but also to the control of other blood-sucking arthropods and related plant pests. Use of bio-based agents for controlling arthropods will contribute to a healthier, more sustainable environment and serve a growing number of organic food farmers.
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Weinberg, Zwi G., Richard E. Muck, Nathan Gollop, Gilad Ashbell, Paul J. Weimer y Limin Kung, Jr. effect of lactic acid bacteria silage inoculants on the ruminal ecosystem, fiber digestibility and animal performance. United States Department of Agriculture, septiembre de 2003. http://dx.doi.org/10.32747/2003.7587222.bard.
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The overall objective of the whole research was to elucidate the mechanisms by which LAB silage inoculants enhance ruminant performance. The results generated will permit the development of better silage inoculants that maximize both silage preservation and animal performance. For this one-year BARD feasibility study, the objectives were to: 1. determine whether lactic acid bacteria (LAB) used in inoculants for silage can survive in rumen fluid (RF) 2.select the inoculants that survived best, and 3. test whether LAB silage inoculants produce bacteriocins-like substances. The most promising strains will be used in the next steps of the research. Silage inoculants containing LAB are used in order to improve forage preservation efficiency. In addition, silage inoculants enhance animal performance in many cases. This includes improvements in feed intake, liveweight gain and milk production in 25-40% of studies reviewed. The cause for the improvement in animal performance is not clear but appears to be other than direct effect of LAB inoculants on silage fermentation. Results from various studies suggest a possible probiotic effect. Our hypothesis is that specific LAB strains interact with rumen microorganisms which results in enhanced rumen functionality and animal performance. The first step of the research is to determine whether LAB of silage inoculants survive in RF. Silage inoculants (12 in the U.S. and 10 in Israel) were added to clarified and strained RF. Inoculation rate was 10 ⁶ (clarified RF), 10⁷ (strained RF) (in the U.S.) and 10⁷, 10⁸ CFU ml⁻¹ in Israel (strained RF). The inoculated RF was incubated for 72 and 96 h at 39°C, with and without 5 g 1⁻¹ glucose. Changes in pH, LAB numbers and fermentation products were monitored throughout the incubation period. The results indicated that LAB silage inoculants can survive in RF. The inoculants with the highest counts after 72 h incubation in rumen fluid were Lactobacillus plantarum MTD1 and a L. plantarum/P. cerevisiae mixture (USA) and Enterococcus faecium strains and Lactobacillus buchneri (Israel). Incubation of rumen fluid with silage LAB inoculants resulted in higher pH values in most cases as compared with that of un-inoculated controls. The magnitude of the effect varied among inoculants and typically was enhanced with the inoculants that survived best. This might suggest the mode of action of LAB silage inoculants in the rumen as higher pH enhances fibrolytic microorganisms in the rumen. Volatile fatty acid (VFA) concentrations in the inoculated RF tended to be lower than in the control RF after incubation. However, L. plalltarull1 MTDI resulted in the highest concentrations of VFA in the RF relative to other inoculants. The implication of this result is not as yet clear. In previous research by others, feeding silages which were inoculated with this strain consistently enhanced animal performance. These finding were recently published in Weinberg et.al.. (2003), J. of Applied Microbiology 94:1066-1071 and in Weinberg et al.. (2003), Applied Biochemistry and Biotechnology (accepted). In addition, some strains in our studies have shown bacteriocins like activity. These included Pediococcus pentosaceus, Enterococcus faecium and Lactobacillus plantarum Mill 1. These results will enable us to continue the research with the LAB strains that survived best in the rumen fluid and have the highest potential to affect the rumen environment.
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Avnimelech, Yoram, Richard C. Stehouwer y Jon Chorover. Use of Composted Waste Materials for Enhanced Ca Migration and Exchange in Sodic Soils and Acidic Minespoils. United States Department of Agriculture, junio de 2001. http://dx.doi.org/10.32747/2001.7575291.bard.
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Restoration of degraded lands and the development of beneficial uses for waste products are important challenges facing our society. In addition there is a need to find useful and environmentally friendly applications for the organic fractions of municipal and other solid waste. Recent studies have shown that composted wastes combined with gypsum or gypsum-containing flue gas desulfurization by-products enhance restoration of sodic soils and acidic minespoils. The mechanism by which this synergistic effect occurs in systems at opposite pH extremes appears to involve enhanced Ca migration and exchange. Our original research objectives were to (1) identify and quantify the active compost components involved in Ca transport, (2) determine the relative affinity of the compost components for Ca and competing metals in the two soil/spoil systems, (3) determine the efficacy of the compost components in Ca transport to subjacent soil and subsequent exchange with native soil cations, and (4) assess the impacts of compost enhanced Ca transport on soil properties and plant growth. Acidic mine spoils: During the course of the project the focus for objective (1) and (2) shifted more towards developing and evaluating methods to appropriately quantify Ca2+ and Al3+ binding to compost derived dissolved organic matter (DOM). It could be shown that calcium complexation by sewage sludge compost derived DOM did not significantly change during the composting process. A method for studying Al3+ binding to DOM was successfully developed and should allow future insight into DOM-Al3+ interactions in general. Laboratory column experiments as well as greenhouse experiments showed that in very acidic mine spoil material mineral dissolution controls solution Al3+ concentration as opposed to exchange with Ca2+. Therefore compost appeared to have no effect on Al3+ and Ca2+ mobility and did not affect subsoil acidity. Sodic alkaline soils: Batch experiments with Na+ saturated cation exchange resins as a model for sodic soils showed that compost home cations exchanged readily with Na+. Unlike filtered compost extracts, unfiltered compost suspensions also significantly increased Ca2+ release from CaCO3. Soil lysimeter experiments demonstrated a clear impact of compost on structural improvement in sodic alkaline soils. Young compost had faster, clearer and longer lasting effects on soil physical and chemical properties than mature compost. Even after 2 growing seasons differences could still be observed. Compost increased Ca2+ concentration in soil solution and solubility of pedogenic CaCO3 that is highly insoluble under alkaline conditions. The solubilized Ca2+ efficiently exchanged Na+ in the compost treated soils and thus greatly improved the soil structure.