Cycloidal Geartrain In-Use Efficiency Study

2018 ◽  
Author(s):  
Logan C. Farrell ◽  
James Holley ◽  
William Bluethmann ◽  
Marcia K. O’Malley
Keyword(s):  
Space Application ◽  
Harmonic Drive ◽  
Actual Performance ◽  
Speed Reducer ◽  
Efficiency Performance ◽  
Use Efficiency ◽  
High Reduction ◽  
Robotic Applications ◽  
Over Time ◽  
Steady State Performance

Currently, harmonic drives are the primary speed reducer for robotic applications where a high reduction in a small package is required. Cycloidal drives are an alternative option for high reduction, small package, use-cases with the advantage of a higher specific torque and the ability to customize and integrate the drive for the application. These compact style cycloidal drives have been well studied in theory and simulation for their performance, but very little data is available on their actual performance over time. This paper presents experimental data on performance of a cycloidal drive designed for a Lunar or Martian rover application. Burn-in time efficiency curves and torque/speed efficiency profiles are computed after running the drive through 129k output cycles (7.6M input cycles) over the course of 300+ hours of testing. The study finds that substantial burn-in time may be required for steady-state performance, but peak efficiencies of 81% can be achieved. Also, the efficiency is shown to be dependent on the torque through the actuator. This work demonstrates a customized cycloidal drive in a space application that is comparable to a harmonic drive in efficiency performance, with a 2x increase in specific torque, suggesting the application of cycloidal drives could grow tremendously in robotic designs.

Increased Use of Computed Tomography Does Not Harm Patients with Acute Appendicitis

2006 ◽  
Vol 72 (4) ◽  
pp. 326-329 ◽  
Author(s):  
Tehillah S. Menes ◽  
Arthur H. Aufses ◽  
Mary Rojas ◽  
Nina A. Bickell
Keyword(s):  
Computed Tomography ◽  
Acute Appendicitis ◽  
Median Time ◽  
Phase 1 ◽  
False Negative ◽  
Phase 2 ◽  
Time To Surgery ◽  
Group Time ◽  
Use Efficiency ◽  
Over Time

The increased use of computed tomography (CT) in patients with appendicitis may cause a delay in surgery and, therefore, higher perforation rates. We examined the use of CT, delay in time to surgery, and perforation rates in appendicitis patients operated on in two periods: Phase 1, 1996 through 1998 and Phase 2, 2001 through 2002. CT was performed in 18 per cent of the Phase 1 group compared with 62 per cent in the Phase 2 group. In the Phase 1 group, patients undergoing CT had a delay to surgery compared with those without CT (18.6 hours vs 7 hours; P < 0.0001). In the Phase 2 group, time to surgery was reduced (median time = 12 hours with CT vs 6 hours without CT; P < 0.001). CT was more accurate in the later group; there were less false-negative and equivocal studies. There was no difference in perforation rates between the Phase 1 and 2 groups. Over time, the increased use, efficiency, and accuracy of CT in patients with acute appendicitis were associated with reduced delays to surgery. The use of CT did not harm patients, but did not translate to better overall outcomes in this group of patients.

Improving Interlending through Goal Setting and Performance Measurement

1993 ◽  
Vol 21 (1) ◽  
pp. 13-17
Author(s):  
John Willemse
Keyword(s):  
Performance Measurement ◽  
Goal Setting ◽  
Performance Measures ◽  
Point Of View ◽  
Actual Performance ◽  
And Performance ◽  
Effective Service ◽  
Over Time ◽  
The Ideal

The local availability of needed publications is, from most users′ point of view, probably the most appropriate measure of a library′s effectiveness. Although immediate availability is the ideal, interlending offers a way to improve availability over time. With the goal of maximum availability in the shortest possible time, the interlending section of the Unisa Library has developed a number of performance measures to determine its effectiveness. The performance measures were instrumental in targeting problem areas which could contribute to a more effective service by technological and other means. Briefly describes the rationale behind the performance measures and the actual performance attained, as well as the factors contributing towards their improvement.

The HAL1 function on Na+homeostasis is maintained over time in salt-treated transgenic tomato plants, but the high reduction of Na+in leaf is not associated with salt tolerance

2008 ◽  
Vol 133 (2) ◽  
pp. 288-297 ◽  
Author(s):  
Alicia Muñoz-Mayor ◽  
Benito Pineda ◽  
Jose O. Garcia-Abellán ◽  
Begoña Garcia-Sogo ◽  
Elena Moyano ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Transgenic Tomato ◽  
Tomato Plants ◽  
Transgenic Tomato Plants ◽  
High Reduction ◽  
Over Time

Teacher Identity Research and Development

2019 ◽  
Author(s):  
Zoe Martínez-de-la-Hidalga ◽  
Lourdes Villardón-Gallego
Keyword(s):  
Professional Identity ◽  
Teacher Identity ◽  
Sociocultural Factors ◽  
Actual Performance ◽  
Dialogic Approach ◽  
Development Of Identity ◽  
The One ◽  
The Individual ◽  
Qualitative Methodologies ◽  
Over Time

Many studies and publications have been devoted to the analysis and development of teacher identity from different points of view, using diverse instruments and methodologies and analyzing different dimensions of identity. Despite the scrutiny, it is still a challenge to understand and define an issue as complex as professional identity. Although there is no clear unanimity on the concept of identity itself, several characteristics have been identified from different approaches. Thus, aspects such as personal unity, stability over time, and across situations and contexts contrast with such features as multiplicity, discontinuity, and a social nature. Faced with this dichotomy, the dialogic perspective explains the complexity of the construct by proposing that the aforementioned features are linked respectively and dialectically. In other words, the various dimensions of identity, along with their variability through time and the influence exerted by social and contextual aspects, are combined with personal unity, with stability over time, and across situations and contexts. This can, occasionally, lead to conflict and contradictions that the individual strives to manage through self-dialogue. Focusing in the dialogic conceptualization, several implications for research are identified. Firstly, it disallows static categorizations of teachers and places the focus on grasping the self-dialogue that allows teachers to maintain a certain degree of stability and coherence in their identity over time. Secondly, it showcases the effect that dialogue and participation-focused research can have on professional development. Additionally, the study of identity in all its complexity and mutability advocates the integrated study of two levels of analysis: On the one hand, there is the position and actions of teachers in different contexts and situations; and, on the other, there is their professional story, past, present and future, along with the sociocultural factors that have impacted it. According to this dialogic approach, both the research on the professional identity and the teacher training should incorporate strategies that promote dialogue on actual performance and on professional careers. To this effect, longitudinal designs help capture the dialogue between stability and change. Still, transversal studies can be undeniably useful to identify current conflicts that might arise between personal and professional roles, as well as how such conflicts are managed. Furthermore, qualitative methodologies have a great potential to generate self-dialogues that provide insight into how teachers live, perceive, and manage such conflicts. Finally, research should be participative in nature so that teachers abandon their role as objects of research and become, instead, its subjects, in collaboration with researchers. In this manner, research on identity leads to changes in the professional identity of participants, in addition to furthering the knowledge available on the subject. Action research follows these guidelines, and it is therefore especially suited to this endeavor. Based on this characterization of the research on professional identity, some techniques are suggested for the collection of information because they foster reflection and consequently also promote development of identity. Some of these techniques are: life stories, narrative of teaching, diaries, case studies, critical events analysis, professional dilemmas, teacher or teaching metaphors, and inquiry-based learning.

Analysis of Evacuation Efficiency Based on Properties of Construction Materials with Seven Popular Space Combinations in Architecture Design

2013 ◽  
Vol 454 ◽  
pp. 169-174
Author(s):  
Hong Xu ◽  
Peng Fei Duan ◽  
Ya Long Huang ◽  
Xia Bin Zhan
Keyword(s):  
Time Use ◽  
Construction Materials ◽  
Experimental System ◽  
Efficiency Index ◽  
Space Time ◽  
Architecture Design ◽  
Digital Architecture ◽  
Advantages And Disadvantages ◽  
Efficiency Performance ◽  
Use Efficiency

How to evaluate the influence of the architecture space combinations effected by the properties of construction materials on the evacuation efficiency is an open and important question to the digital architecture research community. Few research works have been done to investigate the influences. This paper proposed a space-time use efficiency index to evaluate the use efficiency of space and time resources in the evacuation of the public buildings. Then, this paper evaluated the influence of the architecture space combinations on the evacuation efficiency by using the three indicators, namely, the evacuation time, evacuation distance and the proposed space-time use efficiency. The evacuation efficiency performance of the seven popular architecture space combinations which could be constructed different materials were tested by an implemented experimental system prototype, and their advantages and disadvantages were compared to draw a meaning suggestion in the architecture design.

Efficiency performance of fertilizer use in arable agricultural production in China

2019 ◽  
Vol 11 (1) ◽  
pp. 52-69 ◽  
Author(s):  
Wei Huang ◽  
Li Jiang
Keyword(s):  
Agricultural Production ◽  
Design Methodology ◽  
Agricultural Sector ◽  
Positive Impact ◽  
Time Varying ◽  
Content Type ◽  
Fertilizer Use ◽  
Efficiency Performance ◽  
Use Efficiency ◽  
Almost All

PurposeFertilizer overuse is regarded as one of the main contributors to agricultural pollution and environmental problems in China. The purpose of this paper is to evaluate technical efficiency (TE) and fertilizer overuse index (FOI) with respect to China’s arable agricultural production and examine regional variations in terms of fertilizer overuse.Design/methodology/approachThe maximum likelihood random effects–time varying inefficiency effects model was applied to estimate TE, fertilizer use efficiency (FUE) and FOI.FindingsOver the study period (2011–2015), TE steadily increased for each individual province. Overall, mean annual TE was 0.811, implying that, on average, Chinese provinces could increase output by 18.9 per cent given unchanged levels of inputs and technology. Mean annual FOI ranged from 0.008 to 3.139, with a mean of 0.685, suggesting that there is fertilizer overuse in almost all provinces, and that large regional variation exists. Coastal provinces were found to have the highest TE scores, while the central region showed the highest degree of fertilizer overuse.Originality/valueThe results indicate that fertilizer use has had a significant positive impact on production in the China’s arable agricultural sector. High TE was not necessarily associated with low FUE.

scholarly journals RESPOSTAS FISIOLÓGICAS EM VARIEDADES DE CANA SOCA SUBMETIDAS AO DÉFICIT HÍDRICO

Irriga ◽  
2016 ◽  
Vol 21 (4) ◽  
pp. 806-816
Author(s):  
Francisco Rodolfo Junior ◽  
Walter Quadros Ribeiro Junior ◽  
Maria Lucrécia Gerosa Ramos ◽  
Omar Cruz Rocha ◽  
Fábio Pedro Silva Batista ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Agricultural Crops ◽  
Saccharum Spp ◽  
Intrinsic Water Use Efficiency ◽  
Ratoon Sugarcane ◽  
Use Efficiency ◽  
Data Collections ◽  
Over Time

RESPOSTAS FISIOLÓGICAS EM VARIEDADES DE CANA SOCA SUBMETIDAS AO DÉFICIT HÍDRICO              FRANCISCO RODOLFO JUNIOR1; WALTER QUADROS RIBEIRO JUNIOR2; MARIA LUCRÉCIA GEROSA RAMOS3; OMAR CRUZ ROCHA2; FÁBIO PEDRO SILVA BATISTA4 E CRISTIANE ANDRÉA DE LIMA2 1 Universidade Federal do Piauí-CPCE, BR 135, km 03, Planalto Horizonte, CEP 64900-000, Bom Jesus, Piauí, Brasil, [email protected];2Embrapa Cerrados, BR 020 Km 18, Planaltina - DF, CEP 73310-970, [email protected], [email protected], [email protected];3Universidade de Brasília/FAV, Instituto Central de Ciências, Sul (ICC-Sul), CEP 70.910-970, [email protected];4Doutorando do Programa de Pós-Graduação em Agronomia, Universidade de Brasília/FAV, ICC-Sul, CEP 70.910-970, [email protected];  1 RESUMO A baixa disponibilidade hídrica afeta negativamente os cultivos agrícolas e é a principal causa da redução da produtividade no setor sucroalcooleiro no Brasil. O objetivo deste trabalho foi caracterizar fisiologicamente as variedades da cana-de-açúcar, submetidas a diferentes regimes hídricos. O experimento foi conduzido em uma área de 0,36 hectares, localizada na Embrapa Cerrados, próxima a Planaltina-DF. O delineamento foi em blocos ao acaso com três repetições em parcelas subdivididas no tempo, com três variedades (RB855156, RB835486 e RB867515-parcela), ausência e presença da irrigação (irrigado e sequeiro - subparcela) e quatro coletas de dados no tempo (100; 150; 200 e 250 dias após o corte) que foram as subsubparcelas. Foram avaliadas as seguintes características fisiológicas: prolina livre a folha, trocas gasosas: transpiração (E), condutância estomática (gs), fotossíntese líquida (A), eficiência intrínseca do uso da água (EIUA), eficiência da carboxilação (EC), clorofila tipo a (Clo-a) e clorofila total (Clo-a+b). As variedades de cana-de-açúcar cultivadas em sistema de sequeiro apresentaram aumento na concentração foliar de prolina e EIUA, e redução de E, gs, A, EC, Clo-a e Clo-a+b. Palavras-Chave: Saccharum spp. L.; estresse abiótico; prolina; trocas gasosas.  RODOLFO JUNIOR, F.; RIBEIRO JUNIOR, W. Q.; RAMOS, M. L. G.; ROCHA, O. C.; BATISTA, F. P. S.; LIMA, C. A.PHYSIOLOGICAL RESPONSES IN VARIETIES OF RATOON SUGARCANE SUBMITTED TO WATER DEFICIT  2 ABSTRACT Low water supply affects negatively agricultural crops and is the main cause of reduced productivity in the sugar and ethanol industry in Brazil. The objective of this paper was to physiologically characterize the varieties of sugar cane under different water regimes. The experiment was conducted in an area of 0.36 hectares, located in Embrapa Cerrado, near Planaltina-DF. The design was randomized with three replicates in parcels subdivided in time, with three varieties (RB855156, RB835486 and RB867515-plots), with absence and presence of irrigation (irrigated and rainfed- subplots) and four data collections over time  (100; 150; 200 and 250 days after harvest), that formed the subsubplots. The following physiological characteristics were assessed: free proline in leaves, leaf gas exchange: transpiration (E), stomatal conductance (gs), net photosynthesis (A), intrinsic water use efficiency (EIUA), efficiency of carboxylation (EC), chlorophyll type a (Clo-a) e total chlorophyll (Clo-a+b). The varieties of sugarcane cultivated in rainfed system presented increase in leaf concentration of proline and EIUA, and reduced E, gs, A, EC, Cloa, Clo-a+b. Keywords: Saccharum spp. L.; abiotic stress; proline; gas exchange.

Photosynthesis, nitrogen-use efficiency, and water-use efficiency of jack pine seedlings in competition with four boreal forest plant species

2001 ◽  
Vol 31 (11) ◽  
pp. 2014-2025 ◽  
Author(s):  
Darren E Robinson ◽  
Robert G Wagner ◽  
F Wayne Bell ◽  
Clarence J Swanton
Keyword(s):  
Boreal Forest ◽  
Water Use Efficiency ◽  
Water Use ◽  
Nitrogen Use Efficiency ◽  
Jack Pine ◽  
Soil N ◽  
Nitrogen Use ◽  
Pine Seedlings ◽  
Use Efficiency ◽  
Over Time

The objective of this study was to understand the mechanism underlying nitrogen (N) and water competition between jack pine (Pinus banksiana Lamb.) and four boreal forest species. Large-leaved aster (Aster macrophyllus L.), Canada blue-joint grass (Calamagrostis canadensis (Michx.) Beauv.), trembling aspen (Populus tremuloides (Michx.), and red raspberry (Rubus idaeus L.) were planted at a range of densities (0-8 plants/m2) with jack pine seedlings. Net photosynthesis (Pn), nitrogen-use efficiency (NUE), water-use efficiency (WUE) of each species were monitored over three consecutive growing seasons. Changes in available soil N and water were also measured. Jack pine Pn, NUE, and WUE decreased as competitor density increased, but these effects varied among species (p < 0.001) and over time (p < 0.001). The influence of density on jack pine Pn decreased over time for aster and blue-joint grass and increased over time for aspen and raspberry (p < 0.001). At most sample times, jack pine Pn correlated with available soil N. In contrast, the correlation between jack pine Pn and soil water was rarely significant.

scholarly journals Water Markets in the Western United States: Trends and Opportunities

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 233 ◽  
Author(s):  
Kurt Schwabe ◽  
Mehdi Nemati ◽  
Clay Landry ◽  
Grant Zimmerman
Keyword(s):  
Water Scarcity ◽  
State Level ◽  
American Southwest ◽  
Water Markets ◽  
Population Growth Rates ◽  
Water Users ◽  
The Us ◽  
Use Efficiency ◽  
Semi Arid Region ◽  
Over Time

Efforts to address water scarcity have traditionally relied on changing the spatial and temporal availability of water through water importation, storage, and conveyance. More recently, water managers have invested heavily in improving water use efficiency and conservation. Yet as new supply options become harder to find and/or appropriate, and demand hardens, society must consider other options to, if not reduce scarcity, minimize the impacts of such scarcity. This paper explores the role water markets are playing in addressing water scarcity in the American southwest: a water-limited arid and semi-arid region characterized by significant population growth rates relative to the rest of the US. Focusing on three representative southwestern states—Arizona, California, and Texas—we begin by highlighting how trends in water supply allocations from different water sources (e.g., surface water, groundwater, and wastewater) and water demand by different water users (e.g., agricultural, municipal, and environmental) have changed over time within each state. We then present recent data that shows how water trading has changed over time—in terms of value and volume—both at state level and sector level aggregates. We end with a discussion regarding some institutional adjustments that are necessary for water markets to achieve their potential in helping society address water scarcity.

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