Student Achievement and National Economic Growth

ERIC Educational Resources Information Center

Ramirez, Francisco O.; Luo, Xiaowei; Schofer, Evan; Meyer, John W.

2006-01-01

Educational policy around the world has increasingly focused on improving aggregate student achievement as a means to increase economic growth. In the last two decades, attention has focused especially on the importance of achievement in science and mathematics. Yet, the policy commitments involved have not been based on research evidence. The…

Postinfancy growth, schooling, and cognitive achievement: Young Lives.

PubMed

Crookston, Benjamin T; Schott, Whitney; Cueto, Santiago; Dearden, Kirk A; Engle, Patrice; Georgiadis, Andreas; Lundeen, Elizabeth A; Penny, Mary E; Stein, Aryeh D; Behrman, Jere R

2013-12-01

Early life growth failure and resulting cognitive deficits are often assumed to be very difficult to reverse after infancy. We used data from Young Lives, which is an observational cohort of 8062 children in Ethiopia, India, Peru, and Vietnam, to determine whether changes in growth after infancy are associated with schooling and cognitive achievement at age 8 y. We represented the growth by height-for-age z score at 1 y [HAZ(1)] and height-for-age z score at 8 y that was not predicted by the HAZ(1). We also characterized growth as recovered (stunted at age 1 y and not at age 8 y), faltered (not stunted at age 1 y and stunted at age 8 y), persistently stunted (stunted at ages 1 and 8 y), or never stunted (not stunted at ages 1 and 8 y). Outcome measures were assessed at age 8 y. The HAZ(1) was inversely associated with overage for grade and positively associated with mathematics achievement, reading comprehension, and receptive vocabulary. Unpredicted growth from 1 to 8 y of age was also inversely associated with overage for grade (OR range across countries: 0.80-0.84) and positively associated with mathematics achievement (effect-size range: 0.05-0.10), reading comprehension (0.02-0.10), and receptive vocabulary (0.04-0.08). Children who recovered in linear growth had better outcomes than did children who were persistently stunted but were not generally different from children who experienced growth faltering. Improvements in child growth after early faltering might have significant benefits on schooling and cognitive achievement. Hence, although early interventions remain critical, interventions to improve the nutrition of preprimary and early primary school-age children also merit consideration.

Mathematics Coursework Regulates Growth in Mathematics Achievement

ERIC Educational Resources Information Center

Ma, Xin; Wilkins, Jesse L. M.

2007-01-01

Using data from the Longitudinal Study of American Youth (LSAY), we examined the extent to which students' mathematics coursework regulates (influences) the rate of growth in mathematics achievement during middle and high school. Graphical analysis showed that students who started middle school with higher achievement took individual mathematics…

The Growth Patterns of General Medical Achievement.

ERIC Educational Resources Information Center

Shen, Linjun

This longitudinal study investigates the growth of medical achievement as a multilevel process and emphasizes the structure of the growth. Subjects were students in all 15 U.S. osteopathic medical schools, a total of 1,060 (78 percent of the 1987 osteopathic cohort). Students took appropriate portions of the National Board of Osteopathic Medical…

Postinfancy growth, schooling, and cognitive achievement: Young Lives1234

PubMed Central

Schott, Whitney; Cueto, Santiago; Dearden, Kirk A; Engle, Patrice; Georgiadis, Andreas; Lundeen, Elizabeth A; Penny, Mary E; Stein, Aryeh D; Behrman, Jere R

2013-01-01

Background: Early life growth failure and resulting cognitive deficits are often assumed to be very difficult to reverse after infancy. Objective: We used data from Young Lives, which is an observational cohort of 8062 children in Ethiopia, India, Peru, and Vietnam, to determine whether changes in growth after infancy are associated with schooling and cognitive achievement at age 8 y. Design: We represented the growth by height-for-age z score at 1 y [HAZ(1)] and height-for-age z score at 8 y that was not predicted by the HAZ(1). We also characterized growth as recovered (stunted at age 1 y and not at age 8 y), faltered (not stunted at age 1 y and stunted at age 8 y), persistently stunted (stunted at ages 1 and 8 y), or never stunted (not stunted at ages 1 and 8 y). Outcome measures were assessed at age 8 y. Results: The HAZ(1) was inversely associated with overage for grade and positively associated with mathematics achievement, reading comprehension, and receptive vocabulary. Unpredicted growth from 1 to 8 y of age was also inversely associated with overage for grade (OR range across countries: 0.80–0.84) and positively associated with mathematics achievement (effect-size range: 0.05–0.10), reading comprehension (0.02–0.10), and receptive vocabulary (0.04–0.08). Children who recovered in linear growth had better outcomes than did children who were persistently stunted but were not generally different from children who experienced growth faltering. Conclusions: Improvements in child growth after early faltering might have significant benefits on schooling and cognitive achievement. Hence, although early interventions remain critical, interventions to improve the nutrition of preprimary and early primary school–age children also merit consideration. PMID:24067665

Optimum processing of mammographic film.

PubMed

Sprawls, P; Kitts, E L

1996-03-01

Underprocessing of mammographic film can result in reduced contrast and visibility of breast structures and an unnecessary increase in radiation dose to the patient. Underprocessing can be caused by physical factors (low developer temperature, inadequate development time, insufficient developer agitation) or chemical factors (developer not optimized for film type; overdiluted, underreplenished, contaminated, or frequently changed developer). Conventional quality control programs are designed to produce consistent processing but do not address the issue of optimum processing. Optimum processing is defined as the level of processing that produces the film performance characteristics (contrast and sensitivity) specified by the film manufacturer. Optimum processing of mammographic film can be achieved by following a two-step protocol. The first step is to set up the processing conditions according to recommendations from the film and developer chemistry manufacturers. The second step is to verify the processing results by comparing them with sensitometric data provided by the film manufacturer.

Optimum temperature for growth and preferred temperatures of age-0 lake trout

USGS Publications Warehouse

Edsall, Thomas A.; Cleland, Joshua

2000-01-01

This study was performed to determine the thermal preferences and optimum temperature for growth of age-0 lake trout Salvelinus namaycush to help predict the thermal habitat they select when they leave the spawning grounds and to assess the risk posed to them in the Great Lakes by piscivorus, nonnative fishes whose thermal habitat preferences are known. The test fish were hatched in the laboratory from eggs taken from wild fish, acclimated to 5, 10, 15, and 18°C, and fed to excess with commercial trout food for 47 d. The test fish grew at all of the temperatures, and the specific growth rate was highest at about 12.5°C (3.8% wet body weight/d). Fish used in the growth study were also tested in a vertical thermal gradient tank and had a final thermal preferendum between 10.1°C and 10.2°C. These results, which generally agreed with those of an earlier laboratory study of the temperature preference of age-1 lake trout and the limited information on thermal habitat use by age-0 lake trout in the Great Lakes, indicated age-0 lake trout would tend to seek temperatures near 10°C, or as high as 12.5°C, during summer if food was abundant. Published information on thermal habitat use of age-1 and adult alewives Alosa pseudoharengus and rainbow smelt Osmerus mordax indicated they would be expected to co-occur with age-0 lake trout during much of the time when the lake trout were small enough to be eaten by these two introduced piscivores.

Growth mindset tempers the effects of poverty on academic achievement

PubMed Central

Claro, Susana; Paunesku, David; Dweck, Carol S.

2016-01-01

Two largely separate bodies of empirical research have shown that academic achievement is influenced by structural factors, such as socioeconomic background, and psychological factors, such as students’ beliefs about their abilities. In this research, we use a nationwide sample of high school students from Chile to investigate how these factors interact on a systemic level. Confirming prior research, we find that family income is a strong predictor of achievement. Extending prior research, we find that a growth mindset (the belief that intelligence is not fixed and can be developed) is a comparably strong predictor of achievement and that it exhibits a positive relationship with achievement across all of the socioeconomic strata in the country. Furthermore, we find that students from lower-income families were less likely to hold a growth mindset than their wealthier peers, but those who did hold a growth mindset were appreciably buffered against the deleterious effects of poverty on achievement: students in the lowest 10th percentile of family income who exhibited a growth mindset showed academic performance as high as that of fixed mindset students from the 80th income percentile. These results suggest that students’ mindsets may temper or exacerbate the effects of economic disadvantage on a systemic level. PMID:27432947

Growth mindset tempers the effects of poverty on academic achievement.

PubMed

Claro, Susana; Paunesku, David; Dweck, Carol S

2016-08-02

Two largely separate bodies of empirical research have shown that academic achievement is influenced by structural factors, such as socioeconomic background, and psychological factors, such as students' beliefs about their abilities. In this research, we use a nationwide sample of high school students from Chile to investigate how these factors interact on a systemic level. Confirming prior research, we find that family income is a strong predictor of achievement. Extending prior research, we find that a growth mindset (the belief that intelligence is not fixed and can be developed) is a comparably strong predictor of achievement and that it exhibits a positive relationship with achievement across all of the socioeconomic strata in the country. Furthermore, we find that students from lower-income families were less likely to hold a growth mindset than their wealthier peers, but those who did hold a growth mindset were appreciably buffered against the deleterious effects of poverty on achievement: students in the lowest 10th percentile of family income who exhibited a growth mindset showed academic performance as high as that of fixed mindset students from the 80th income percentile. These results suggest that students' mindsets may temper or exacerbate the effects of economic disadvantage on a systemic level.

Achieving workforce growth in UK nursing: policy options and implications.

PubMed

Buchan, James

2009-01-01

This paper examines how the National Health Service (NHS) in the UK achieved significant nursing workforce growth during the period between 2000 and 2006 and discusses the policy implications of the methods used to achieve this staffing growth. Data analysis, literature review and policy analysis. NHS nurse staffing growth was approximately 25% over the period 1997-2007, with most growth occurring in the years between 1999 and 2005. Whilst increases in intakes to home-based pre-registration education was a factor in achieving growth, the pace and level of growth which occurred was only possible by using active international recruitment, which was adopted as a deliberate national policy. The numbers of nurses and midwives entering the UK from other countries increased rapidly from 1999 onwards, to a peak in 2002, and then reduced markedly in the period from 2005 onwards. The policy of supporting international recruitment shifted rapidly in late 2005/2006 when financial difficulties hit the NHS and staffing growth was curtailed. Active international recruitment can contribute to health sector staffing growth, assuming the recruiting country has the resources to recruit and can tap into international markets, but it may not be effective in addressing all types of skills shortages. If it is not well linked to other components of workforce planning it may cause difficulties of over expansion, as well as raising broader issues of the ethics and impact.

Growth trajectories of mathematics achievement: Longitudinal tracking of student academic progress.

PubMed

Mok, Magdalena M C; McInerney, Dennis M; Zhu, Jinxin; Or, Anthony

2015-06-01

A number of methods to investigate growth have been reported in the literature, including hierarchical linear modelling (HLM), latent growth modelling (LGM), and multidimensional scaling applied to longitudinal profile analysis (LPAMS). This study aimed at modelling the mathematics growth of students over a span of 6 years from Grade 3 to Grade 9. The sample comprised secondary longitudinal data collected in three waves from n = 866 Hong Kong students when they were in Grade 3, Grade 6, and Grade 9. Mathematics achievement was measured thrice on a vertical scale linked with anchor items. Linear and nonlinear latent growth models were used to assess students' growth. Gender differences were also examined. A nonlinear latent growth curve with a decelerated rate had a good fit to the data. Initial achievement and growth rate were negatively correlated. No gender difference was found. Mathematics growth from Grade 6 to Grade 9 was slower than that from Grade 3 to Grade 6. Students with lower initial achievement improved at a faster rate than those who started at a higher level. Gender did not affect growth rate. © 2014 The British Psychological Society.

Parent involvement and science achievement: A latent growth curve analysis

NASA Astrophysics Data System (ADS)

Johnson, Ursula Yvette

This study examined science achievement growth across elementary and middle school and parent school involvement using the Early Childhood Longitudinal Study - Kindergarten Class of 1998--1999 (ECLS-K). The ECLS-K is a nationally representative kindergarten cohort of students from public and private schools who attended full-day or half-day kindergarten class in 1998--1999. The present study's sample (N = 8,070) was based on students that had a sampling weight available from the public-use data file. Students were assessed in science achievement at third, fifth, and eighth grades and parents of the students were surveyed at the same time points. Analyses using latent growth curve modeling with time invariant and varying covariates in an SEM framework revealed a positive relationship between science achievement and parent involvement at eighth grade. Furthermore, there were gender and racial/ethnic differences in parents' school involvement as a predictor of science achievement. Findings indicated that students with lower initial science achievement scores had a faster rate of growth across time. The achievement gap between low and high achievers in earth, space and life sciences lessened from elementary to middle school. Parents' involvement with school usually tapers off after elementary school, but due to parent school involvement being a significant predictor of eighth grade science achievement, later school involvement may need to be supported and better implemented in secondary schooling.

Expert meeting on Child Growth and Micronutrient Deficiencies--New Initiatives for Developing Countries to Achieve Millennium Development Goals: executive summary report.

PubMed

Usfar, Avita A; Achadi, Endang L; Martorell, Reynaldo; Hadi, Hamam; Thaha, Razak; Jus'at, Idrus; Atmarita; Martianto, Drajat; Ridwan, Hardinsyah; Soekirman

2009-01-01

Undernutrition in early childhood has long-term physical and intellectual consequences. Improving child growth should start before the age of two years and be an integrated effort between all sectors, covering all aspects such as diet and nutrient intake, disease reduction, optimum child care, and improved environmental sanitation. To discuss these issues, the Indonesian Danone Institute Foundation organized an expert meeting on Child Growth and Micronutrient Deficiencies: New Initiatives for Developing Countries to Achieve Millennium Development Goals. The objective of the meeting was to have a retrospective view on child growth: lessons learned from programs to overcome under-nutrition in the developed countries and to relate the situation to the Indonesian context, as well as to discuss implications for future programs. Recommendations derived from the meeting include focus intervention on the window of opportunity group, re-activation of the Integrated Health Post at the village level, improvement of infant and young child feeding, expand food fortification intervention programs, strengthen supplementation programs with multi-micronutrient, and strengthening public and private partnership on food related programs.

Analytical Solution for Optimum Design of Furrow Irrigation Systems

NASA Astrophysics Data System (ADS)

Kiwan, M. E.

1996-05-01

An analytical solution for the optimum design of furrow irrigation systems is derived. The non-linear calculus optimization method is used to formulate a general form for designing the optimum system elements under circumstances of maximizing the water application efficiency of the system during irrigation. Different system bases and constraints are considered in the solution. A full irrigation water depth is considered to be achieved at the tail of the furrow line. The solution is based on neglecting the recession and depletion times after off-irrigation. This assumption is valid in the case of open-end (free gradient) furrow systems rather than closed-end (closed dike) systems. Illustrative examples for different systems are presented and the results are compared with the output obtained using an iterative numerical solution method. The final derived solution is expressed as a function of the furrow length ratio (the furrow length to the water travelling distance). The function of water travelling developed by Reddy et al. is considered for reaching the optimum solution. As practical results from the study, the optimum furrow elements for free gradient systems can be estimated to achieve the maximum application efficiency, i.e. furrow length, water inflow rate and cutoff irrigation time.

2015 National Award for Smart Growth Achievement Booklet

EPA Pesticide Factsheets

Page linking to videos and booklet about the winners of the 2015 National Award for Smart Growth Achievement: Jackson Walk, Jackson, TN; City of Hamilton and Historic Developers Public-Private Partnership, Hamilton, OH; and Riverfront Park, Newark, NJ.

Investigation of the Optimum Farming Temperature for Grifola frondosa and Growth Promotion using the Bio-Electric Potential as an Index

NASA Astrophysics Data System (ADS)

Yanagibashi, Hideyuki; Hirama, Junji; Matsuda, Masato; Miyamoto, Toshio

The purpose of this study was to investigate the optimum farming conditions for mushrooms from the view point of engineering field. As the bio-electric potential of mushrooms is considered to be closely related to the activation of mushroom cells, this relationship has been used to analyze the dependence of the morphogenetic characteristics of Grifola frondosa on farming temperatures (from 16 to 22 degree C). The experimental results indicated that a maximum response was exhibited, with correspondingly favorable morphogenesis obtained at 18 degree C. Based on the experimental results, including those in a previous study, it was assumed that the larger the bio-electric potential becomes, the higher the growth yield reaches. In order to support this assumption, growth promotion was conducted by intentionally activating the bio-electric potential within the mushrooms by stimulating them with short bursts of illumination. The resulting observation of growth promotion permitted the conclusion that the bio-electric potential can, indeed, be regarded as an index of growth.

Once, Sometimes, or Always in Special Education: Mathematics Growth and Achievement Gaps

ERIC Educational Resources Information Center

Schulte, Ann C.; Stevens, Joseph J.

2015-01-01

This study used a statewide longitudinal sample to examine mathematics achievement gaps and growth in students with and without disabilities and to examine the impact of different methods of determining disability group membership on achievement gaps and growth. When disability status was determined on the basis of special education placement each…

The Influence of Parents' Involvement on Children with Special Needs' Motivation and Learning Achievement

ERIC Educational Resources Information Center

Bariroh, Siti

2018-01-01

Some of the abnormal children face burden, distraction, interruption, tardiness, or risk factors so that they cannot get an optimum growth without special treatment or intervention. This study was aimed at discovering the influence of parents' involvement to the learning motivation and achievement of children with different abilities. This…

Documenting Reading Achievement and Growth for Students Taking Alternate Assessments

ERIC Educational Resources Information Center

Tindal, Gerald; Nese, Joseph F. T.; Farley, Dan; Saven, Jessica L.; Elliott, Stephen N.

2016-01-01

Students with disabilities have been included in state accountability systems for more than a decade; however, only in the past few years have alternate assessments of alternate achievement standards (AA-AAS) become stable enough to allow examination of these students' achievement growth. Using data from Oregon's AA-AAS in Reading during the…

Optimum Projection Angle for Attaining Maximum Distance in a Soccer Punt Kick

PubMed Central

Linthorne, Nicholas P.; Patel, Dipesh S.

2011-01-01

To produce the greatest horizontal distance in a punt kick the ball must be projected at an appropriate angle. Here, we investigated the optimum projection angle that maximises the distance attained in a punt kick by a soccer goalkeeper. Two male players performed many maximum-effort kicks using projection angles of between 10° and 90°. The kicks were recorded by a video camera at 100 Hz and a 2 D biomechanical analysis was conducted to obtain measures of the projection velocity, projection angle, projection height, ball spin rate, and foot velocity at impact. The player’s optimum projection angle was calculated by substituting mathematical equations for the relationships between the projection variables into the equations for the aerodynamic flight of a soccer ball. The calculated optimum projection angles were in agreement with the player’s preferred projection angles (40° and 44°). In projectile sports even a small dependence of projection velocity on projection angle is sufficient to produce a substantial shift in the optimum projection angle away from 45°. In the punt kicks studied here, the optimum projection angle was close to 45° because the projection velocity of the ball remained almost constant across all projection angles. This result is in contrast to throwing and jumping for maximum distance, where the projection velocity the athlete is able to achieve decreases substantially with increasing projection angle and so the optimum projection angle is well below 45°. Key points The optimum projection angle that maximizes the distance of a punt kick by a soccer goalkeeper is about 45°. The optimum projection angle is close to 45° because the projection velocity of the ball is almost the same at all projection angles. This result is in contrast to throwing and jumping for maximum distance, where the optimum projection angle is well below 45° because the projection velocity the athlete is able to achieve decreases substantially with increasing

Predictors of early growth in academic achievement: the head-toes-knees-shoulders task

PubMed Central

McClelland, Megan M.; Cameron, Claire E.; Duncan, Robert; Bowles, Ryan P.; Acock, Alan C.; Miao, Alicia; Pratt, Megan E.

2014-01-01

Children's behavioral self-regulation and executive function (EF; including attentional or cognitive flexibility, working memory, and inhibitory control) are strong predictors of academic achievement. The present study examined the psychometric properties of a measure of behavioral self-regulation called the Head-Toes-Knees-Shoulders (HTKS) by assessing construct validity, including relations to EF measures, and predictive validity to academic achievement growth between prekindergarten and kindergarten. In the fall and spring of prekindergarten and kindergarten, 208 children (51% enrolled in Head Start) were assessed on the HTKS, measures of cognitive flexibility, working memory (WM), and inhibitory control, and measures of emergent literacy, mathematics, and vocabulary. For construct validity, the HTKS was significantly related to cognitive flexibility, working memory, and inhibitory control in prekindergarten and kindergarten. For predictive validity in prekindergarten, a random effects model indicated that the HTKS significantly predicted growth in mathematics, whereas a cognitive flexibility task significantly predicted growth in mathematics and vocabulary. In kindergarten, the HTKS was the only measure to significantly predict growth in all academic outcomes. An alternative conservative analytical approach, a fixed effects analysis (FEA) model, also indicated that growth in both the HTKS and measures of EF significantly predicted growth in mathematics over four time points between prekindergarten and kindergarten. Results demonstrate that the HTKS involves cognitive flexibility, working memory, and inhibitory control, and is substantively implicated in early achievement, with the strongest relations found for growth in achievement during kindergarten and associations with emergent mathematics. PMID:25071619

High-Achieving and Average Students' Reading Growth: Contrasting School and Summer Trajectories

ERIC Educational Resources Information Center

Rambo-Hernandez, Karen E.; McCoach, D. Betsy

2015-01-01

Much is unknown about how initially high-achieving students grow academically, especially given the measurement issues inherent in assessing growth for the highest performing students. This study compared initially high-achieving and average students' growth in reading (in a cohort of third-grade students from 2,000 schools) over 3 years.…

Promising Practices in Professional Growth & Support: "Case Study of Achievement First"

ERIC Educational Resources Information Center

Education Resource Strategies, 2013

2013-01-01

Four organizations with promising practices in teacher Professional Growth & Support have significantly raised outcomes for low-income students. The charter management networks, Achievement First and Aspire Public Schools, and the two reform organizations, Teach Plus and Agile Mind, have successfully increased student achievement with a…

Achieving optimal growth: lessons from simple metabolic modules

NASA Astrophysics Data System (ADS)

Goyal, Sidhartha; Chen, Thomas; Wingreen, Ned

2009-03-01

Metabolism is a universal property of living organisms. While the metabolic network itself has been well characterized, the logic of its regulation remains largely mysterious. Recent work has shown that growth rates of microorganisms, including the bacterium Escherichia coli, correlate well with optimal growth rates predicted by flux-balance analysis (FBA), a constraint-based computational method. How difficult is it for cells to achieve optimal growth? Our analysis of representative metabolic modules drawn from real metabolism shows that, in all cases, simple feedback inhibition allows nearly optimal growth. Indeed, product-feedback inhibition is found in every biosynthetic pathway and constitutes about 80% of metabolic regulation. However, we find that product-feedback systems designed to approach optimal growth necessarily produce large pool sizes of metabolites, with potentially detrimental effects on cells via toxicity and osmotic imbalance. Interestingly, the sizes of metabolite pools can be strongly restricted if the feedback inhibition is ultrasensitive (i.e. with high Hill coefficient). The need for ultrasensitive mechanisms to limit pool sizes may therefore explain some of the ubiquitous, puzzling complexity found in metabolic feedback regulation at both the transcriptional and post-transcriptional levels.

Science and Mathematics Advanced Placement Exams: Growth and Achievement over Time

ERIC Educational Resources Information Center

Judson, Eugene

2017-01-01

Rapid growth of Advanced Placement (AP) exams in the last 2 decades has been paralleled by national enthusiasm to promote availability and rigor of science, technology, engineering, and mathematics (STEM). Trends were examined in STEM AP to evaluate and compare growth and achievement. Analysis included individual STEM subjects and disaggregation…

Cognitive Predictors of Achievement Growth in Mathematics: A Five Year Longitudinal Study

PubMed Central

Geary, David C.

2011-01-01

The study's goal was to identify the beginning of first grade quantitative competencies that predict mathematics achievement start point and growth through fifth grade. Measures of number, counting, and arithmetic competencies were administered in early first grade and used to predict mathematics achievement through fifth (n = 177), while controlling for intelligence, working memory, and processing speed. Multilevel models revealed intelligence, processing speed, and the central executive component of working memory predicted achievement or achievement growth in mathematics and, as a contrast domain, word reading. The phonological loop was uniquely predictive of word reading and the visuospatial sketch pad of mathematics. Early fluency in processing and manipulating numerical set size and Arabic numerals, accurate use of sophisticated counting procedures for solving addition problems, and accuracy in making placements on a mathematical number line were uniquely predictive of mathematics achievement. Use of memory-based processes to solve addition problems predicted mathematics and reading achievement but in different ways. The results identify the early quantitative competencies that uniquely contribute to mathematics learning. PMID:21942667

El Salvador: Aid Compensates for Economic Losses but Achieves Little Growth

DTIC Science & Technology

1991-02-15

earthquake. Aid Helped Achieve Almost half of U.S. economic assistance to El Salvador has supported its Economic Stability but economy by providing cash to the...Economic Growth 15 Economic Stability but Conclusions 21 Little Growth Chapter 3 22 Maintaining Social Funds for Health and Education Are Limited 22...comments as appropriate. Page I I GAO/NSIAD-91-97 El Salvador Chapter 2 U.S. and Salvadoran Efforts Bring Economic Stability but Little Growth AID’S

Web-dendritic ribbon growth

NASA Technical Reports Server (NTRS)

Hilborn, R. B., Jr.; Faust, J. W., Jr.

1976-01-01

A web furnace was constructed for pulling dendritic-web samples. The effect of changes in the furnace thermal geometry on the growth of dendritic-web was studied. Several attempts were made to grow primitive dendrites for use as the dendritic seed crystals for web growth and to determine the optimum twin spacing in the dendritic seed crystal for web growth. Mathematical models and computer programs were used to determine the thermal geometries in the susceptor, crucible melt, meniscus, and web. Several geometries were determined for particular furnace geometries and growth conditions. The information obtained was used in conjunction with results from the experimental growth investigations in order to achieve proper conditions for sustained pulling of two dendrite web ribbons. In addition, the facilities for obtaining the following data were constructed: twin spacing, dislocation density, web geometry, resistivity, majority charge carrier type, and minority carrier lifetime.

Cognitive predictors of children's development in mathematics achievement: A latent growth modeling approach.

PubMed

Xenidou-Dervou, Iro; Van Luit, Johannes E H; Kroesbergen, Evelyn H; Friso-van den Bos, Ilona; Jonkman, Lisa M; van der Schoot, Menno; van Lieshout, Ernest C D M

2018-04-24

Research has identified various domain-general and domain-specific cognitive abilities as predictors of children's individual differences in mathematics achievement. However, research into the predictors of children's individual growth rates, namely between-person differences in within-person change in mathematics achievement is scarce. We assessed 334 children's domain-general and mathematics-specific early cognitive abilities and their general mathematics achievement longitudinally across four time-points within the first and second grades of primary school. As expected, a constellation of multiple cognitive abilities contributed to the children's starting level of mathematical success. Specifically, latent growth modeling revealed that WM abilities, IQ, counting skills, nonsymbolic and symbolic approximate arithmetic and comparison skills explained individual differences in the children's initial status on a curriculum-based general mathematics achievement test. Surprisingly, however, only one out of all the assessed cognitive abilities was a unique predictor of the children's individual growth rates in mathematics achievement: their performance in the symbolic approximate addition task. In this task, children were asked to estimate the sum of two large numbers and decide if this estimated sum was smaller or larger compared to a third number. Our findings demonstrate the importance of multiple domain-general and mathematics-specific cognitive skills for identifying children at risk of struggling with mathematics and highlight the significance of early approximate arithmetic skills for the development of one's mathematical success. We argue the need for more research focus on explaining children's individual growth rates in mathematics achievement. © 2018 John Wiley & Sons Ltd.

Precollege science achievement growth: Racial-ethnic and gender differences in cognitive and psychosocial constructs

NASA Astrophysics Data System (ADS)

Muller, Patricia Ann

The purpose of this study was to gain a more complete understanding of the differences in science, mathematics and engineering education among racial-ethnic and gender subgroups by exploring factors related to precollege science achievement growth rates. Using Hierarchical Linear Modeling (HLM) and multi-wave, longitudinal data from the first three waves of the National Education Longitudinal Study of 1988--1994 (NELS:88/94), this study examined precollege science achievement growth rates during the 8th to 10th grade period and the 10th to 12th grade period for African American males, African American females, Latino males, Latina females, Asian American males, Asian American females, White males and White females. For the 8th--10th grade period, previous grades were significantly and positively related to science achievement growth for all subgroups; and socio-economic status and high school program were significantly and positively related to science achievement growth for all subgroups except one (Latino males, and Asian American males respectively). For the 10th--12th grade period, the quantity of science courses completed (science units) was the only variable that was statistically significant for more than one racial-ethnic by gender subgroup. Science units taken were significantly and positively related to 10 th--12th grade growth rates for all racial-ethnic by gender subgroups except Latino males. Locus-of-control was the only cognitive or psychosocial factor included from Eccles, Adler, Futterman, Goff, Kaczala, Meece and Midgley's (1983) theoretical framework for achievement behaviors that appeared to exhibit any pattern across race-ethnicities. Locus-of-control was positively related to 8th--10 th grade science achievement growth for females across all racial-ethnic subgroups, as well as for African American males. However, for both the 8 th--10th grade and 10th--12 th grade periods, there was no consistency across racial-ethnic or gender subgroups in

Prediction of the optimum surface orientation angles to achieve maximum solar radiation using Particle Swarm Optimization in Sabha City Libya

NASA Astrophysics Data System (ADS)

Mansour, F. A.; Nizam, M.; Anwar, M.

2017-02-01

This research aims to predict the optimum surface orientation angles in solar panel installation to achieve maximum solar radiation. Incident solar radiation is calculated using koronakis mathematical model. Particle Swarm Optimization (PSO) is used as computational method to find optimum angle orientation for solar panel installation in order to get maximum solar radiation. A series of simulation has been carried out to calculate solar radiation based on monthly, seasonally, semi-yearly and yearly period. South-facing was calculated also as comparison of proposed method. South-facing considers azimuth of 0°. Proposed method attains higher incident predictions than South-facing that recorded 2511.03 kWh/m2for monthly. It were about 2486.49 kWh/m2, 2482.13 kWh/m2and 2367.68 kWh/m2 for seasonally, semi-yearly and yearly. South-facing predicted approximately 2496.89 kWh/m2, 2472.40 kWh/m2, 2468.96 kWh/m2, 2356.09 kWh/m2for monthly, seasonally, semi-yearly and yearly periods respectively. Semi-yearly is the best choice because it needs twice adjustments of solar panel in a year. Yet it considers inefficient to adjust solar panel position in every season or monthly with no significant solar radiation increase than semi-yearly and solar tracking device still considers costly in solar energy system. PSO was able to predict accurately with simple concept, easy and computationally efficient. It has been proven by finding the best fitness faster.

Predicting long-term growth in students' mathematics achievement: the unique contributions of motivation and cognitive strategies.

PubMed

Murayama, Kou; Pekrun, Reinhard; Lichtenfeld, Stephanie; Vom Hofe, Rudolf

2013-01-01

This research examined how motivation (perceived control, intrinsic motivation, and extrinsic motivation), cognitive learning strategies (deep and surface strategies), and intelligence jointly predict long-term growth in students' mathematics achievement over 5 years. Using longitudinal data from six annual waves (Grades 5 through 10; Mage  = 11.7 years at baseline; N = 3,530), latent growth curve modeling was employed to analyze growth in achievement. Results showed that the initial level of achievement was strongly related to intelligence, with motivation and cognitive strategies explaining additional variance. In contrast, intelligence had no relation with the growth of achievement over years, whereas motivation and learning strategies were predictors of growth. These findings highlight the importance of motivation and learning strategies in facilitating adolescents' development of mathematical competencies. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.

Optimum 3D Matrix Stiffness for Maintenance of Cancer Stem Cells Is Dependent on Tissue Origin of Cancer Cells

PubMed Central

Jabbari, Esmaiel; Sarvestani, Samaneh K.; Daneshian, Leily; Moeinzadeh, Seyedsina

2015-01-01

Introduction The growth and expression of cancer stem cells (CSCs) depend on many factors in the tumor microenvironment. The objective of this work was to investigate the effect of cancer cells’ tissue origin on the optimum matrix stiffness for CSC growth and marker expression in a model polyethylene glycol diacrylate (PEGDA) hydrogel without the interference of other factors in the microenvironment. Methods Human MCF7 and MDA-MB-231 breast carcinoma, HCT116 colorectal and AGS gastric carcinoma, and U2OS osteosarcoma cells were used. The cells were encapsulated in PEGDA gels with compressive moduli in the 2-70 kPa range and optimized cell seeding density of 0.6x106 cells/mL. Micropatterning was used to optimize the growth of encapsulated cells with respect to average tumorsphere size. The CSC sub-population of the encapsulated cells was characterized by cell number, tumorsphere size and number density, and mRNA expression of CSC markers. Results The optimum matrix stiffness for growth and marker expression of CSC sub-population of cancer cells was 5 kPa for breast MCF7 and MDA231, 25 kPa for colorectal HCT116 and gastric AGS, and 50 kPa for bone U2OS cells. Conjugation of a CD44 binding peptide to the gel stopped tumorsphere formation by cancer cells from different tissue origin. The expression of YAP/TAZ transcription factors by the encapsulated cancer cells was highest at the optimum stiffness indicating a link between the Hippo transducers and CSC growth. The optimum average tumorsphere size for CSC growth and marker expression was 50 μm. Conclusion The marker expression results suggest that the CSC sub-population of cancer cells resides within a niche with optimum stiffness which depends on the cancer cells’ tissue origin. PMID:26168187

Optimum Wing Shape of Highly Flexible Morphing Aircraft for Improved Flight Performance

NASA Technical Reports Server (NTRS)

Su, Weihua; Swei, Sean Shan-Min; Zhu, Guoming G.

2016-01-01

In this paper, optimum wing bending and torsion deformations are explored for a mission adaptive, highly flexible morphing aircraft. The complete highly flexible aircraft is modeled using a strain-based geometrically nonlinear beam formulation, coupled with unsteady aerodynamics and six-degrees-of-freedom rigid-body motions. Since there are no conventional discrete control surfaces for trimming the flexible aircraft, the design space for searching the optimum wing geometries is enlarged. To achieve high performance flight, the wing geometry is best tailored according to the specific flight mission needs. In this study, the steady level flight and the coordinated turn flight are considered, and the optimum wing deformations with the minimum drag at these flight conditions are searched by utilizing a modal-based optimization procedure, subject to the trim and other constraints. The numerical study verifies the feasibility of the modal-based optimization approach, and shows the resulting optimum wing configuration and its sensitivity under different flight profiles.

Optimum rocket propulsion for energy-limited transfer

NASA Technical Reports Server (NTRS)

Zuppero, Anthony; Landis, Geoffrey A.

1991-01-01

In order to effect large-scale return of extraterrestrial resources to Earth orbit, it is desirable to optimize the propulsion system to maximize the mass of payload returned per unit energy expended. This optimization problem is different from the conventional rocket propulsion optimization. A rocket propulsion system consists of an energy source plus reaction mass. In a conventional chemical rocket, the energy source and the reaction mass are the same. For the transportation system required, however, the best system performance is achieved if the reaction mass used is from a locally available source. In general, the energy source and the reaction mass will be separate. One such rocket system is the nuclear thermal rocket, in which the energy source is a reactor and the reaction mass a fluid which is heated by the reactor and exhausted. Another energy-limited rocket system is the hydrogen/oxygen rocket where H2/O2 fuel is produced by electrolysis of water using a solar array or a nuclear reactor. The problem is to choose the optimum specific impulse (or equivalently exhaust velocity) to minimize the amount of energy required to produce a given mission delta-v in the payload. The somewhat surprising result is that the optimum specific impulse is not the maximum possible value, but is proportional to the mission delta-v. In general terms, at the beginning of the mission it is optimum to use a very low specific impulse and expend a lot of reaction mass, since this is the most energy efficient way to transfer momentum. However, as the mission progresses, it becomes important to minimize the amount of reaction mass expelled, since energy is wasted moving the reaction mass. Thus, the optimum specific impulse will increase with the mission delta-v. Optimum I(sub sp) is derived for maximum payload return per energy expended for both the case of fixed and variable I(sub sp) engines. Sample missions analyzed include return of water payloads from the moons of Mars and of

Cognitive Predictors of Achievement Growth in Mathematics: A 5-Year Longitudinal Study

ERIC Educational Resources Information Center

Geary, David C.

2011-01-01

The study's goal was to identify the beginning of 1st grade quantitative competencies that predict mathematics achievement start point and growth through 5th grade. Measures of number, counting, and arithmetic competencies were administered in early 1st grade and used to predict mathematics achievement through 5th (n = 177), while controlling for…

Design of an adaptive CubeSat transmitter for achieving optimum signal-to-noise ratio (SNR)

NASA Astrophysics Data System (ADS)

Jaswar, F. D.; Rahman, T. A.; Hindia, M. N.; Ahmad, Y. A.

2017-12-01

CubeSat technology has opened the opportunity to conduct space-related researches at a relatively low cost. Typical approach to maintain an affordable cubeSat mission is to use a simple communication system, which is based on UHF link with fixed-transmit power and data rate. However, CubeSat in the Low Earth Orbit (LEO) does not have relative motion with the earth rotation, resulting in variable propagation path length that affects the transmission signal. A transmitter with adaptive capability to select multiple sets of data rate and radio frequency (RF) transmit power is proposed to improve and optimise the link. This paper presents the adaptive UHF transmitter design as a solution to overcome the variability of the propagation path. The transmitter output power is adjustable from 0.5W to 2W according to the mode of operations and satellite power limitations. The transmitter is designed to have four selectable modes to achieve the optimum signal-to-noise ratio (SNR) and efficient power consumption based on the link budget analysis and satellite requirement. Three prototypes are developed and tested for space-environment conditions such as the radiation test. The Total Ionizing Dose measurements are conducted in the radiation test done at Malaysia Nuclear Agency Laboratory. The results from this test have proven that the adaptive transmitter can perform its operation with estimated more than seven months in orbit. This radiation test using gamma source with 1.5krad exposure is the first one conducted for a satellite program in Malaysia.

Modeling stability of growth between mathematics and science achievement during middle and high school.

PubMed

Ma, Xin; Ma, Lingling

2004-04-01

In this study, the authors introduced a multivariate multilevel model to estimate the consistency among students and schools in the rates of growth between mathematics and science achievement during the entire middle and high school years with data from the Longitudinal Study of American Youth (LSAY). There was no evident consistency in the rates of growth between mathematics and science achievement among students, and this inconsistency was not much influenced by student characteristics and school characteristics. However, there was evident consistency in the average rates of growth between mathematics and science achievement among schools, and this consistency was influenced by student characteristics and school characteristics. Major school-level variables associated with parental involvement did not show any significant impacts on consistency among either students or schools. Results call for educational policies that promote collaboration between mathematics and science departments or teachers.

Parent Involvement and Science Achievement: A Latent Growth Curve Analysis

ERIC Educational Resources Information Center

Johnson, Ursula Yvette

2011-01-01

This study examined science achievement growth across elementary and middle school and parent school involvement using the Early Childhood Longitudinal Study-Kindergarten Class of 1998-1999 (ECLS-K). The ECLS-K is a nationally representative kindergarten cohort of students from public and private schools who attended full-day or half-day…

The optimum spanning catenary cable

NASA Astrophysics Data System (ADS)

Wang, C. Y.

2015-03-01

A heavy cable spans two points in space. There exists an optimum cable length such that the maximum tension is minimized. If the two end points are at the same level, the optimum length is 1.258 times the distance between the ends. The optimum lengths for end points of different heights are also found.

The Groove of Growth: How Early Gains in Math Ability Influence Adolescent Achievement

ERIC Educational Resources Information Center

Watts, Tyler W.; Duncan, Greg J.; Siegler, Robert S.; Davis-Kean, Pamela E.

2014-01-01

A number of studies, both small scale and of nationally-representative student samples, have reported substantial associations between school entry math ability and later elementary school achievement. However, questions remain regarding the persistence of the association between early growth in math ability and later math achievement due to the…

Optimum Wing Shape Determination of Highly Flexible Morphing Aircraft for Improved Flight Performance.

PubMed

Su, Weihua; Swei, Sean Shan-Min; Zhu, Guoming G

2016-09-01

In this paper, optimum wing bending and torsion deformations are explored for a mission adaptive, highly flexible morphing aircraft. The complete highly flexible aircraft is modeled using a strain-based geometrically nonlinear beam formulation, coupled with unsteady aerodynamics and 6-dof rigid-body motions. Since there are no conventional discrete control surfaces for trimming the flexible aircraft, the design space for searching the optimum wing geometries is enlarged. To achieve high performance flight, the wing geometry is best tailored according to the specific flight mission needs. In this study, the steady level flight and the coordinated turn flight are considered, and the optimum wing deformations with the minimum drag at these flight conditions are searched by utilizing a modal-based optimization procedure, subject to the trim and other constraints. The numerical study verifies the feasibility of the modal-based optimization approach, and shows the resulting optimum wing configuration and its sensitivity under different flight profiles.

Optimum Wing Shape Determination of Highly Flexible Morphing Aircraft for Improved Flight Performance

PubMed Central

Su, Weihua; Swei, Sean Shan-Min; Zhu, Guoming G.

2018-01-01

In this paper, optimum wing bending and torsion deformations are explored for a mission adaptive, highly flexible morphing aircraft. The complete highly flexible aircraft is modeled using a strain-based geometrically nonlinear beam formulation, coupled with unsteady aerodynamics and 6-dof rigid-body motions. Since there are no conventional discrete control surfaces for trimming the flexible aircraft, the design space for searching the optimum wing geometries is enlarged. To achieve high performance flight, the wing geometry is best tailored according to the specific flight mission needs. In this study, the steady level flight and the coordinated turn flight are considered, and the optimum wing deformations with the minimum drag at these flight conditions are searched by utilizing a modal-based optimization procedure, subject to the trim and other constraints. The numerical study verifies the feasibility of the modal-based optimization approach, and shows the resulting optimum wing configuration and its sensitivity under different flight profiles. PMID:29348697

Exploring Gains in Reading and Mathematics Achievement among Regular and Exceptional Students Using Growth Curve Modeling

ERIC Educational Resources Information Center

Shin, Tacksoo; Davison, Mark L.; Long, Jeffrey D.; Chan, Chi-Keung; Heistad, David

2013-01-01

Using four-wave longitudinal reading and mathematics data (4th to 7th grades) from a large urban school district, growth curve modeling was used as a tool for examining three research questions: Are achievement gaps closing in reading and mathematics? What are the associations between prior-achievement and growth across the reading and mathematics…

A firefly algorithm for optimum design of new-generation beams

NASA Astrophysics Data System (ADS)

Erdal, F.

2017-06-01

This research addresses the minimum weight design of new-generation steel beams with sinusoidal openings using a metaheuristic search technique, namely the firefly method. The proposed algorithm is also used to compare the optimum design results of sinusoidal web-expanded beams with steel castellated and cellular beams. Optimum design problems of all beams are formulated according to the design limitations stipulated by the Steel Construction Institute. The design methods adopted in these publications are consistent with BS 5950 specifications. The formulation of the design problem considering the above-mentioned limitations turns out to be a discrete programming problem. The design algorithms based on the technique select the optimum universal beam sections, dimensional properties of sinusoidal, hexagonal and circular holes, and the total number of openings along the beam as design variables. Furthermore, this selection is also carried out such that the behavioural limitations are satisfied. Numerical examples are presented, where the suggested algorithm is implemented to achieve the minimum weight design of these beams subjected to loading combinations.

Growth Mixture Modeling of Academic Achievement in Children of Varying Birth Weight Risk

PubMed Central

Espy, Kimberly Andrews; Fang, Hua; Charak, David; Minich, Nori; Taylor, H. Gerry

2009-01-01

The extremes of birth weight and preterm birth are known to result in a host of adverse outcomes, yet studies to date largely have used cross-sectional designs and variable-centered methods to understand long-term sequelae. Growth mixture modeling (GMM) that utilizes an integrated person- and variable-centered approach was applied to identify latent classes of achievement from a cohort of school-age children born at varying birth weights. GMM analyses revealed two latent achievement classes for calculation, problem-solving, and decoding abilities. The classes differed substantively and persistently in proficiency and in growth trajectories. Birth weight was a robust predictor of class membership for the two mathematics achievement outcomes and a marginal predictor of class membership for decoding. Neither visuospatial-motor skills nor environmental risk at study entry added to class prediction for any of the achievement skills. Among children born preterm, neonatal medical variables predicted class membership uniquely beyond birth weight. More generally, GMM is useful in revealing coherence in the developmental patterns of academic achievement in children of varying weight at birth, and is well suited to investigations of sources of heterogeneity. PMID:19586210

Nondissipative optimum charge regulator

NASA Technical Reports Server (NTRS)

Rosen, R.; Vitebsky, J. N.

1970-01-01

Optimum charge regulator provides constant level charge/discharge control of storage batteries. Basic power transfer and control is performed by solar panel coupled to battery through power switching circuit. Optimum controller senses battery current and modifies duty cycle of switching circuit to maximize current available to battery.

Development of Non-Optimum Factors for Launch Vehicle Propellant Tank Bulkhead Weight Estimation

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Wallace, Matthew L.; Cerro, Jeffrey A.

2012-01-01

Non-optimum factors are used during aerospace conceptual and preliminary design to account for the increased weights of as-built structures due to future manufacturing and design details. Use of higher-fidelity non-optimum factors in these early stages of vehicle design can result in more accurate predictions of a concept s actual weights and performance. To help achieve this objective, non-optimum factors are calculated for the aluminum-alloy gores that compose the ogive and ellipsoidal bulkheads of the Space Shuttle Super-Lightweight Tank propellant tanks. Minimum values for actual gore skin thicknesses and weld land dimensions are extracted from selected production drawings, and are used to predict reference gore weights. These actual skin thicknesses are also compared to skin thicknesses predicted using classical structural mechanics and tank proof-test pressures. Both coarse and refined weights models are developed for the gores. The coarse model is based on the proof pressure-sized skin thicknesses, and the refined model uses the actual gore skin thicknesses and design detail dimensions. To determine the gore non-optimum factors, these reference weights are then compared to flight hardware weights reported in a mass properties database. When manufacturing tolerance weight estimates are taken into account, the gore non-optimum factors computed using the coarse weights model range from 1.28 to 2.76, with an average non-optimum factor of 1.90. Application of the refined weights model yields non-optimum factors between 1.00 and 1.50, with an average non-optimum factor of 1.14. To demonstrate their use, these calculated non-optimum factors are used to predict heavier, more realistic gore weights for a proposed heavy-lift launch vehicle s propellant tank bulkheads. These results indicate that relatively simple models can be developed to better estimate the actual weights of large structures for future launch vehicles.

Urban Middle-Grade Student Mathematics Achievement Growth under Comprehensive School Reform

ERIC Educational Resources Information Center

Mac Iver, Martha Abele; Mac Iver, Douglas J.

2009-01-01

Recognizing the need to implement standards-based instructional materials with school-wide coherence led some Philadelphia schools to adopt whole-school reform (WSR) models during the late 1990s. The authors report on the relation between mathematics achievement growth for middle-grade students on the Pennsylvania System of School Assessments and…

Gazing Past the Gaps: A Growth-Based Assessment of the Mathematics Achievement of Black Girls

ERIC Educational Resources Information Center

Young, Jemimah L.; Young, Jamaal R.; Capraro, Robert M.

2018-01-01

The purpose of this study was to proffer the idea to "gaze" past gender and racial achievement gaps by providing a growth-based assessment of the achievement of Black girls. The study aims to elucidate how alternatives to traditional achievement gap analyses can yield information relevant to addressing classroom challenges. This…

Design issues for optimum solar cell configuration

NASA Astrophysics Data System (ADS)

Kumar, Atul; Thakur, Ajay D.

2018-05-01

A computer based simulation of solar cell structure is performed to study the optimization of pn junction configuration for photovoltaic action. The fundamental aspects of photovoltaic action viz, absorption, separation collection, and their dependence on material properties and deatails of device structures is discussed. Using SCAPS 1D we have simulated the ideal pn junction and shown the effect of band offset and carrier densities on solar cell performance. The optimum configuration can be achieved by optimizing transport of carriers in pn junction under effect of field dependent recombination (tunneling) and density dependent recombination (SRH, Auger) mechanisms.

Modeling and optimum time performance for concurrent processing

NASA Technical Reports Server (NTRS)

Mielke, Roland R.; Stoughton, John W.; Som, Sukhamoy

1988-01-01

The development of a new graph theoretic model for describing the relation between a decomposed algorithm and its execution in a data flow environment is presented. Called ATAMM, the model consists of a set of Petri net marked graphs useful for representing decision-free algorithms having large-grained, computationally complex primitive operations. Performance time measures which determine computing speed and throughput capacity are defined, and the ATAMM model is used to develop lower bounds for these times. A concurrent processing operating strategy for achieving optimum time performance is presented and illustrated by example.

Estimation of the optimum digestible lysine level for Cherry Valley ducks.

PubMed

Zhou, Y F; Liu, Y Q; Wei, H K; Peng, J

2017-04-01

The aim of the current study was to determine the digestible lysine (DLys) requirement of Cherry Valley ducks from 1 to 14 d and from 15 to 35 d of age. One-day-old male Cherry Valley ducks (n = 320) were divided randomly and evenly into five treatments with 8 replicates of 8 birds. Ducks were fed adequate levels of digestible amino acid but with graded levels of DLys: 0.80, 0.88, 0.96, 1.04, and 1.12% from 1 to 14 d; 0.60, 0.68, 0.76, 0.84, and 0.92% from 15 to 35 d. At 35 d of age, 8 ducks per treatment were slaughtered for evaluating the yields of abdominal fat, subcutaneous fat, breast meat, and leg meat. Additionally, a 7-d metabolizable experiment was conducted with ducks of the same hatch beginning on d 35 (8 ducks per treatment). The results showed that the DLys level in diet had a quadratic relationship both with the average daily gain (ADG) and feed:gain ratio (F/G). According to the quadratic model, an optimum digestible lysine level was 0.948% from 0 to 14 d and 0.758% from 15 to 35 d based on ADG. The digestible lysine level for obtaining minimum F/G were 0.986% (0 ∼ 14 d) and 0.792% (15 ∼ 35 d), respectively. Breast meat yield (P = 0.110) and subcutaneous fat percentage (P = 0.021) showed a quadratic or linear response to the increasing dietary DLys level. To achieve maximum breast meat yield, the digestible lysine level of 0.961% and 0.761% were needed for the starter period (1 ∼ 14 d) and the growth period (14 ∼ 35 d), respectively. N excretion showed a quadratic response to the increasing dietary DLys level (P = 0.103). The results of the current study suggested that the optimum digestible lysine level was very different with the response criterion. The dietary digestible lysine levels were 0.948, 0.961% in the starter period (1 ∼ 14 d) and 0.758, 0.761% in the growth period (15 ∼ 35 d) for ADG, F/G, respectively. © 2016 Poultry Science Association Inc.

Design optimum frac jobs using virtual intelligence techniques

NASA Astrophysics Data System (ADS)

Mohaghegh, Shahab; Popa, Andrei; Ameri, Sam

2000-10-01

Designing optimal frac jobs is a complex and time-consuming process. It usually involves the use of a two- or three-dimensional computer model. For the computer models to perform as intended, a wealth of input data is required. The input data includes wellbore configuration and reservoir characteristics such as porosity, permeability, stress and thickness profiles of the pay layers as well as the overburden layers. Among other essential information required for the design process is fracturing fluid type and volume, proppant type and volume, injection rate, proppant concentration and frac job schedule. Some of the parameters such as fluid and proppant types have discrete possible choices. Other parameters such as fluid and proppant volume, on the other hand, assume values from within a range of minimum and maximum values. A potential frac design for a particular pay zone is a combination of all of these parameters. Finding the optimum combination is not a trivial process. It usually requires an experienced engineer and a considerable amount of time to tune the parameters in order to achieve desirable outcome. This paper introduces a new methodology that integrates two virtual intelligence techniques, namely, artificial neural networks and genetic algorithms to automate and simplify the optimum frac job design process. This methodology requires little input from the engineer beyond the reservoir characterizations and wellbore configuration. The software tool that has been developed based on this methodology uses the reservoir characteristics and an optimization criteria indicated by the engineer, for example a certain propped frac length, and provides the detail of the optimum frac design that will result in the specified criteria. An ensemble of neural networks is trained to mimic the two- or three-dimensional frac simulator. Once successfully trained, these networks are capable of providing instantaneous results in response to any set of input parameters. These

On the optimum signal constellation design for high-speed optical transport networks.

PubMed

Liu, Tao; Djordjevic, Ivan B

2012-08-27

In this paper, we first describe an optimum signal constellation design algorithm, which is optimum in MMSE-sense, called MMSE-OSCD, for channel capacity achieving source distribution. Secondly, we introduce a feedback channel capacity inspired optimum signal constellation design (FCC-OSCD) to further improve the performance of MMSE-OSCD, inspired by the fact that feedback channel capacity is higher than that of systems without feedback. The constellations obtained by FCC-OSCD are, however, OSNR dependent. The optimization is jointly performed together with regular quasi-cyclic low-density parity-check (LDPC) code design. Such obtained coded-modulation scheme, in combination with polarization-multiplexing, is suitable as both 400 Gb/s and multi-Tb/s optical transport enabling technology. Using large girth LDPC code, we demonstrate by Monte Carlo simulations that a 32-ary signal constellation, obtained by FCC-OSCD, outperforms previously proposed optimized 32-ary CIPQ signal constellation by 0.8 dB at BER of 10(-7). On the other hand, the LDPC-coded 16-ary FCC-OSCD outperforms 16-QAM by 1.15 dB at the same BER.

The Role of PS Ability and RC Skill in Predicting Growth Trajectories of Mathematics Achievement

ERIC Educational Resources Information Center

Vista, Alvin

2016-01-01

There are relatively few studies in Australia and South-East Asian region that combine investigating models of math growth trajectories with predictors such as reasoning ability and reading comprehension skills. Math achievement is one of the major components of overall academic achievement and it is important to determine what factors (especially…

Optimum Parameters for Freeze-Drying Decellularized Arterial Scaffolds

PubMed Central

Sheridan, William S.; Duffy, Garry P.

2013-01-01

Decellularized arterial scaffolds have achieved success in advancing toward clinical use as vascular grafts. However, concerns remain regarding long-term preservation and sterilization of these scaffolds. Freeze drying offers a means of overcoming these concerns. In this study, we investigated the effects of various freeze-drying protocols on decellularized porcine carotid arteries and consequently, determined the optimum parameters to fabricate a stable, preserved scaffold with unaltered mechanical properties. Freeze drying by constant slow cooling to two final temperatures ((Tf), −10°C and −40°C) versus instant freezing was investigated by histological examination and mechanical testing. Slow cooling to Tf= −10°C produced a stiffer and less distensible response than the non freeze-dried scaffolds and resulted in disruption to the collagen fibers. The mechanical response of Tf= −40°C scaffolds demonstrated disruption to the elastin network, which was confirmed with histology. Snap freezing scaffolds in liquid nitrogen and freeze drying to Tf= −40°C with a precooled shelf at −60°C produced scaffolds with unaltered mechanical properties and a histology resembling non-freeze-dried scaffolds. The results of this study demonstrate the importance of optimizing the nucleation and ice crystal growth/size to ensure homogenous drying, preventing extracellular matrix disruption and subsequent inferior mechanical properties. This new manufacturing protocol creates the means for the preservation and sterilization of decellularized arterial scaffolds while simultaneously maintaining the mechanical properties of the tissue. PMID:23614758

Improved carbon nanotube growth inside an anodic aluminum oxide template using microwave radiation

NASA Astrophysics Data System (ADS)

Dadras, Sedigheh; Faraji, Maryam

2018-05-01

In this study, we achieved superfast growth of carbon nanotubes (CNTs) in an anodic aluminum oxide (AAO) template by applying microwave (MW) radiation. This is a simple and direct approach for growing CNTs using a MW oven. The CNTs were synthesized using MW radiation at a frequency of 2.45 GHz and power was applied at various levels of 900, 600, and 450 W. We used graphite and ferrocene in equal portions as precursors. The optimum conditions for the growth of CNTs inside a MW oven were a time period of 5 s and power of 450 W. In order to grow uniform CNTs, an AAO template was applied with the CNTs synthesized under optimum conditions. The morphology of the synthesized CNTs was investigated by scanning electron microscopy analysis. The average diameters of the CNTs obtained without the template were 22-27 nm, whereas the diameters of the CNTs prepared inside the AAO template were about 4-6 nm.

Optimum Operating Conditions for PZT Actuators for Vibrotactile Wearables

NASA Astrophysics Data System (ADS)

Logothetis, Irini; Matsouka, Dimitra; Vassiliadis, Savvas; Vossou, Clio; Siores, Elias

2018-04-01

Recently, vibrotactile wearables have received much attention in fields such as medicine, psychology, athletics and video gaming. The electrical components presently used to generate vibration are rigid; hence, the design and creation of ergonomical wearables are limited. Significant advances in piezoelectric components have led to the production of flexible actuators such as piezoceramic lead zirconate titanate (PZT) film. To verify the functionality of PZT actuators for use in vibrotactile wearables, the factors influencing the electromechanical conversion were analysed and tested. This was achieved through theoretical and experimental analyses of a monomorph clamped-free structure for the PZT actuator. The research performed for this article is a three-step process. First, a theoretical analysis presents the equations governing the actuator. In addition, the eigenfrequency of the film was analysed preceding the experimental section. For this stage, by applying an electric voltage and varying the stimulating electrical characteristics (i.e., voltage, electrical waveform and frequency), the optimum operating conditions for a PZT film were determined. The tip displacement was measured referring to the mechanical energy converted from electrical energy. From the results obtained, an equation for the mechanical behaviour of PZT films as actuators was deduced. It was observed that the square waveform generated larger tip displacements. In conjunction with large voltage inputs at the predetermined eigenfrequency, the optimum operating conditions for the actuator were achieved. To conclude, PZT films can be adapted to assist designers in creating comfortable vibrotactile wearables.

Optimum Operating Conditions for PZT Actuators for Vibrotactile Wearables

NASA Astrophysics Data System (ADS)

Logothetis, Irini; Matsouka, Dimitra; Vassiliadis, Savvas; Vossou, Clio; Siores, Elias

2018-07-01

Recently, vibrotactile wearables have received much attention in fields such as medicine, psychology, athletics and video gaming. The electrical components presently used to generate vibration are rigid; hence, the design and creation of ergonomical wearables are limited. Significant advances in piezoelectric components have led to the production of flexible actuators such as piezoceramic lead zirconate titanate (PZT) film. To verify the functionality of PZT actuators for use in vibrotactile wearables, the factors influencing the electromechanical conversion were analysed and tested. This was achieved through theoretical and experimental analyses of a monomorph clamped-free structure for the PZT actuator. The research performed for this article is a three-step process. First, a theoretical analysis presents the equations governing the actuator. In addition, the eigenfrequency of the film was analysed preceding the experimental section. For this stage, by applying an electric voltage and varying the stimulating electrical characteristics (i.e., voltage, electrical waveform and frequency), the optimum operating conditions for a PZT film were determined. The tip displacement was measured referring to the mechanical energy converted from electrical energy. From the results obtained, an equation for the mechanical behaviour of PZT films as actuators was deduced. It was observed that the square waveform generated larger tip displacements. In conjunction with large voltage inputs at the predetermined eigenfrequency, the optimum operating conditions for the actuator were achieved. To conclude, PZT films can be adapted to assist designers in creating comfortable vibrotactile wearables.

Studying the Relationship between Children's Self-Control and Academic Achievement: An Application of Second-Order Growth Curve Model Analysis.

ERIC Educational Resources Information Center

Kim, Sooyeon; Murry, Velma McBride; Brody, Gene H.

The functional relationships between developmental change in children's self-control and academic achievement were examined using longitudinal family data. Multivariate latent growth models (LGM) were specified to determine whether the rate of growth in academic achievement changes as a function of developmental change in self-control. Data came…

Determining the Optimum Power Load in Jump Squat Using the Mean Propulsive Velocity

PubMed Central

Loturco, Irineu; Nakamura, Fabio Yuzo; Tricoli, Valmor; Kobal, Ronaldo; Cal Abad, Cesar Cavinato; Kitamura, Katia; Ugrinowitsch, Carlos; Gil, Saulo; Pereira, Lucas Adriano; González-Badillo, Juan José

2015-01-01

The jump squat is one of the exercises most frequently used to improve lower body power production, which influences sports performance. However, the traditional determination of the specific workload at which power production is maximized (i.e., optimum power load) is time-consuming and requires one-repetition maximum tests. Therefore, the aim of this study was to verify whether elite athletes from different sports would produce maximum mean propulsive power values at a narrow range of mean propulsive velocities, resulting in similar jump heights. One hundred and nine elite athletes from several individual/team sport disciplines underwent repetitions at maximal velocity with progressive loads, starting at 40% of their body mass with increments of 10% to determine the individual optimum power zone. Results indicated that regardless of sport discipline, the athletes’ optimum mean propulsive power was achieved at a mean propulsive velocity close to 1.0 m.s−1 (1.01 ± 0.07 m.s−1) and at a jump height close to 20 cm (20.47 ± 1.42 cm). Data were narrowly scattered around these values. Therefore, jump squat optimum power load can be determined simply by means of mean propulsive velocity or jump height determination in training/testing settings, allowing it to be implemented quickly in strength/power training. PMID:26444293

Method of thermally processing superplastically formed aluminum-lithium alloys to obtain optimum strengthening

NASA Technical Reports Server (NTRS)

Anton, Claire E. (Inventor)

1993-01-01

Optimum strengthening of a superplastically formed aluminum-lithium alloy structure is achieved via a thermal processing technique which eliminates the conventional step of solution heat-treating immediately following the step of superplastic forming of the structure. The thermal processing technique involves quenching of the superplastically formed structure using static air, forced air or water quenching.

Developing an Optimum Protocol for Thermoluminescence Dosimetry with GR-200 Chips using Taguchi Method.

PubMed

Sadeghi, Maryam; Faghihi, Reza; Sina, Sedigheh

2017-06-15

Thermoluminescence dosimetry (TLD) is a powerful technique with wide applications in personal, environmental and clinical dosimetry. The optimum annealing, storage and reading protocols are very effective in accuracy of TLD response. The purpose of this study is to obtain an optimum protocol for GR-200; LiF: Mg, Cu, P, by optimizing the effective parameters, to increase the reliability of the TLD response using Taguchi method. Taguchi method has been used in this study for optimization of annealing, storage and reading protocols of the TLDs. A number of 108 GR-200 chips were divided into 27 groups, each containing four chips. The TLDs were exposed to three different doses, and stored, annealed and read out by different procedures as suggested by Taguchi Method. By comparing the signal-to-noise ratios the optimum dosimetry procedure was obtained. According to the results, the optimum values for annealing temperature (°C), Annealing Time (s), Annealing to Exposure time (d), Exposure to Readout time (d), Pre-heat Temperature (°C), Pre-heat Time (s), Heating Rate (°C/s), Maximum Temperature of Readout (°C), readout time (s) and Storage Temperature (°C) are 240, 90, 1, 2, 50, 0, 15, 240, 13 and -20, respectively. Using the optimum protocol, an efficient glow curve with low residual signals can be achieved. Using optimum protocol obtained by Taguchi method, the dosimetry can be effectively performed with great accuracy. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Antimicrobial gageomacrolactins characterized from the fermentation of the marine-derived bacterium Bacillus subtilis under optimum growth conditions.

PubMed

Tareq, Fakir Shahidullah; Kim, Ji Hye; Lee, Min Ah; Lee, Hyi-Seung; Lee, Jong-Seok; Lee, Yeon-Ju; Shin, Hee Jae

2013-04-10

Marine bacteria are a potential source of structurally diversified bioactive secondary metabolites that are not found in terrestrial sources. In our continuous effort to search for new antimicrobial agents from marine-derived bacteria, we isolated bacterial strain 109GGC020 from a marine sediment sample collected from Gageocho, Republic of Korea. The strain was identified as Bacillus subtilis based on a 16s rRNA sequence analysis. After a 7-day fermentation of the B. subtilis strain under optimum growth conditions three new and four known secondary metabolites were discovered using chromatographic procedures, and their biological activities were evaluated against both bacteria and crop-devastating fungi. The discovered metabolites were confirmed by extensive 2D NMR and high-resolution ESI-MS data analyses to have the structures of new macrolactin derivatives gageomacrolactins 1-3 and known macrolactins A (4), B (5), F (6), and W (7). The stereoconfigurations of 1-3 were assigned based on coupling constant values, chemical derivatization studies, and a literature review. The coupling constants were very crucial to determine the relative geometries of olefins in 1-3 because of overlap of the ¹H NMR signals. The NMR data of these compounds were recorded in different solvents to overcome this problem and obtain accurate coupling constant values. The new macrolactin derivatives 1-3 displayed good antibiotic properties against both Gram-positive (S. aureus, B. subtilis, and B. cereus) and Gram-negative (E. coli, S. typhi, and P. aeruginosa) bacteria with minimum inhibitory concentration (MIC) values of 0.02-0.05 μM. Additionally, the antifungal activities of 1-7 were evaluated against pathogenic fungi and found to inhibit mycelial growth of A. niger, B. cinerea, C. acutatum, C. albicans, and R. solani with MIC values of 0.04-0.3 μM, demonstrating that these compounds were good fungicides.

Teacher Morale, Student Engagement, and Student Achievement Growth in Reading: A Correlational Study

ERIC Educational Resources Information Center

Sabin, Jenny T.

2015-01-01

This research study explored the current state of teacher morale in fourth and fifth grade classrooms in three low socio-economic schools in North Carolina. Additional research questions address correlational relationships among the variables of teacher morale, student engagement, and student achievement growth as measured by the NC Teacher…

Optimum dietary protein requirement of Malaysian mahseer (Tor tambroides) fingerling.

PubMed

Misieng, Josephine Dorin; Kamarudin, Mohd Salleh; Musa, Mazlinda

2011-02-01

The optimum dietary protein requirement of the Malaysian mahseer (Tor tambroides) fingerlings was determined in this study. In this completely randomized designed experiment, formulated diets of five levels of dietary protein (30, 35, 40, 45 and 50%) were tested on the T. tambroides fingerlings (initial body weight of 5.85 +/- 0.40 g), reared in aquarium fitted with a biofiltering system. The fingerlings were fed twice daily at 5% of biomass. The fingerling body weight and total length was taken at every two weeks. Mortality was recorded daily. The dietary protein had significant effects on the body weight gain and Specific Growth Rate (SGR) of the fingerlings. The body weight gain and SGR of fingerlings fed with the diet with the dietary protein level of 40% was significantly higher (p<0.05) than that of 30, 35 and 50%. The feed conversion ratio of the 40% dietary protein was the significantly lowest at 2.19 +/- 0.163. The dietary protein level of 40% was the most optimum for T. tambroides fingerlings.

Regulating thrombus growth and stability to achieve an optimal response to injury

PubMed Central

Brass, Lawrence F.; Wannemacher, Kenneth M.; Ma, Peisong; Stalker, Timothy J.

2012-01-01

An optimal platelet response to injury can be defined as one in which blood loss is restrained and haemostasis is achieved without the penalty of further tissue damage caused by unwarranted vascular occlusion. This brief review considers some of the ways in which thrombus growth and stability can be regulated so that an optimal platelet response can be achieved in vivo. Three related topics are considered. The first focuses on intracellular mechanisms that regulate the early events of platelet activation downstream of G protein coupled receptors for agonists such as thrombin, thromboxane A2 and ADP. The second considers the ways in which signalling events that are dependent on stable contacts between platelets can influence the state of platelet activation and thus affect thrombus growth and stability. The third focuses on the changes that are experienced by platelets as they move from their normal environment in freely-flowing plasma to a very different environment within the growing haemostatic plug, an environment in which the narrowing gaps and junctions between platelets not only facilitate communication, but also increasingly limit both the penetration of plasma and the exodus of platelet-derived bioactive molecules. PMID:21781243

Matching technique yields optimum LNA performance. [Low Noise Amplifiers

NASA Technical Reports Server (NTRS)

Sifri, J. D.

1986-01-01

The present article is concerned with a case in which an optimum noise figure and unconditional stability have been designed into a 2.385-GHz low-noise preamplifier via an unusual method for matching the input with a suspended line. The results obtained with several conventional line-matching techniques were not satisfactory. Attention is given to the minimization of thermal noise, the design procedure, requirements for a high-impedance line, a sampling of four matching networks, the noise figure of the single-line matching network as a function of frequency, and the approaches used to achieve unconditional stability.

Using hierarchical linear growth models to evaluate protective mechanisms that mediate science achievement

NASA Astrophysics Data System (ADS)

von Secker, Clare Elaine

The study of students at risk is a major topic of science education policy and discussion. Much research has focused on describing conditions and problems associated with the statistical risk of low science achievement among individuals who are members of groups characterized by problems such as poverty and social disadvantage. But outcomes attributed to these factors do not explain the nature and extent of mechanisms that account for differences in performance among individuals at risk. There is ample theoretical and empirical evidence that demographic differences should be conceptualized as social contexts, or collections of variables, that alter the psychological significance and social demands of life events, and affect subsequent relationships between risk and resilience. The hierarchical linear growth models used in this dissertation provide greater specification of the role of social context and the protective effects of attitude, expectations, parenting practices, peer influences, and learning opportunities on science achievement. While the individual influences of these protective factors on science achievement were small, their cumulative effect was substantial. Meta-analysis conducted on the effects associated with psychological and environmental processes that mediate risk mechanisms in sixteen social contexts revealed twenty-two significant differences between groups of students. Positive attitudes, high expectations, and more intense science course-taking had positive effects on achievement of all students, although these factors were not equally protective in all social contexts. In general, effects associated with authoritative parenting and peer influences were negative, regardless of social context. An evaluation comparing the performance and stability of hierarchical linear growth models with traditional repeated measures models is included as well.

Reading and math achievement profiles and longitudinal growth trajectories of children with an autism spectrum disorder.

PubMed

Wei, Xin; Christiano, Elizabeth R A; Yu, Jennifer W; Wagner, Mary; Spiker, Donna

2015-02-01

This study examined the reading and math achievement profiles and longitudinal growth trajectories of a nationally representative sample of children ages 6 through 9 with an autism spectrum disorder. Four distinct achievement profiles were identified: higher-achieving (39%), hyperlexia (9%), hypercalculia (20%) and lower-achieving (32%). Children with hypercalculia and lower-achieving profiles were more likely to be from low socioeconomic families and had lower functional cognitive skills than the higher-achieving profile. All four profiles lost ground in passage comprehension over time. Slower improvement occurred for the higher-achieving group on letter-word identification, the hyperlexia group on conversation abilities and the hypercalculia group on calculation and functional cognitive skills relative to the lower-achieving group. © The Author(s) 2014.

Optimum Design of LLC Resonant Converter using Inductance Ratio (Lm/Lr)

NASA Astrophysics Data System (ADS)

Palle, Kowstubha; Krishnaveni, K.; Ramesh Reddy, Kolli

2017-06-01

The main benefits of LLC resonant dc/dc converter over conventional series and parallel resonant converters are its light load regulation, less circulating currents, larger bandwidth for zero voltage switching, and less tuning of switching frequency for controlled output. An unique analytical tool, called fundamental harmonic approximation with peak gain adjustment is used for designing the converter. In this paper, an optimum design of the converter is proposed by considering three different design criterions with different values of inductance ratio (Lm/Lr) to achieve good efficiency at high input voltage. The optimum design includes the analysis in operating range, switching frequency range, primary side losses of a switch and stability. The analysis is carried out with simulation using the software tools like MATLAB and PSIM. The performance of the optimized design is demonstrated for a design specification of 12 V, 5 A output operating with an input voltage range of 300-400 V using FSFR 2100 IC of Texas instruments.

Optimum reentry trajectories of a lifting vehicle

NASA Technical Reports Server (NTRS)

Chern, J. S.; Vinh, N. X.

1980-01-01

Research results are presented of an investigation of the optimum maneuvers of advanced shuttle type spacecraft during reentry. The equations are formulated by means of modified Chapman variables resulting in a general set of equations for flight analysis which are exact for reentry and for flight in a vacuum. Four planar flight typical optimum manuevers are investigated. For three-dimensional flight the optimum trajectory for maximum cross range is discussed in detail. Techniques for calculating reentry footprints are presented.

Optimum germination temperatures

Treesearch

Richard M. Godman; Gilbert A. Mattson

1992-01-01

Why is sugar maple abundant under nearly all stand conditions, and why do hemlock and yellow birch, although differing in tolerance, occur together as a type? At least part of the answer may have to do with the optimum germinating temperatures for their seeds.

Optimum allocation of redundancy among subsystems connected in series. Ph.D. Thesis - Case Western Reserve Univ., Sep. 1970

NASA Technical Reports Server (NTRS)

Bien, D. D.

1973-01-01

This analysis considers the optimum allocation of redundancy in a system of serially connected subsystems in which each subsystem is of the k-out-of-n type. Redundancy is optimally allocated when: (1) reliability is maximized for given costs; or (2) costs are minimized for given reliability. Several techniques are presented for achieving optimum allocation and their relative merits are discussed. Approximate solutions in closed form were attainable only for the special case of series-parallel systems and the efficacy of these approximations is discussed.

Designing from minimum to optimum functionality

NASA Astrophysics Data System (ADS)

Bannova, Olga; Bell, Larry

2011-04-01

This paper discusses a multifaceted strategy to link NASA Minimal Functionality Habitable Element (MFHE) requirements to a compatible growth plan; leading forward to evolutionary, deployable habitats including outpost development stages. The discussion begins by reviewing fundamental geometric features inherent in small scale, vertical and horizontal, pressurized module configuration options to characterize applicability to meet stringent MFHE constraints. A proposed scenario to incorporate a vertical core MFHE concept into an expanded architecture to provide continuity of structural form and a logical path from "minimum" to "optimum" design of a habitable module. The paper describes how habitation and logistics accommodations could be pre-integrated into a common Hab/Log Module that serves both habitation and logistics functions. This is offered as a means to reduce unnecessary redundant development costs and to avoid EVA-intensive on-site adaptation and retrofitting requirements for augmented crew capacity. An evolutionary version of the hard shell Hab/Log design would have an expandable middle section to afford larger living and working accommodations. In conclusion, the paper illustrates that a number of cargo missions referenced for NASA's 4.0.0 Lunar Campaign Scenario could be eliminated altogether to expedite progress and reduce budgets. The plan concludes with a vertical growth geometry that provides versatile and efficient site development opportunities using a combination of hard Hab/Log modules and a hybrid expandable "CLAM" (Crew Lunar Accommodations Module) element.

Studies on optimum harvest time for hybrid rice seed.

PubMed

Fu, Hong; Cao, Dong-Dong; Hu, Wei-Min; Guan, Ya-Jing; Fu, Yu-Ying; Fang, Yong-Feng; Hu, Jin

2017-03-01

Timely harvest is critical for hybrid rice to achieve maximum seed viability, vigor and yield. However, how to predict the optimum harvest time has been rarely reported so far. The seed vigor of Zhuliangyou 06 (ZLY06) increased and reached the highest level at 20 days after pollination (DAP), when seed moisture content had a lower value, which was maintained until final seed maturation. For Chunyou 84 (CY84), seed vigor, fresh and dry weight had relatively high values at 25 DAP, when seed moisture content reached the lowest value and changed slightly from 25 to 55 DAP. In both hybrid rice varieties, seed glume chlorophyll content declined rapidly from 10 to 30 DAP and remained at a very low level after 35 DAP. Starch content exhibited an increasing trend during seed maturation, while both soluble sugar content and amylase activity decreased significantly at the early stages of seed development. Moreover, correlation analyses showed that seed dry weight, starch content and superoxide dismutase activity were significantly positively correlated with seed vigor. In contrast, chlorophyll content, moisture content, soluble sugar, soluble protein, abscisic acid, gibberellin content, electrical conductivity, catalase and ascorbate peroxidase activities were significantly negatively correlated with seed vigor. Physiological and biochemical parameters were obviously more closely related with seed vigor than with seed germinability during seed development. Seed vigor could be better used as a comprehensive factor to predict the optimum seed harvest time. It is suggested that for ZLY06 seeds could be harvested as early as 20 DAP, whereas for CY84 the earliest optimum harvest time was 25 DAP. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

How To Achieve Good Library Acoustics.

ERIC Educational Resources Information Center

Wiens, Janet

2003-01-01

Discusses how to create a good acoustical environment for college libraries, focusing on requirements related to the HVAC system and lighting, and noting the importance of good maintenance. A sidebar looks at how to design and achieve the most appropriate HVAC and lighting systems for optimum library acoustics. (SM)

[Effects of temperature on the embryonic development and larval growth of Sepia lycidas].

PubMed

Jiang, Xia-Min; Peng, Rui-Bing; Luo, Jiang; Tang, Feng

2013-05-01

A single-factor experiment was conducted to study the effects of different temperature (15, 18, 21, 24, 27, 30, and 33 degrees C) on the embryonic development and larval growth of Sepia lycidas, aimed to search for the optimum temperature for the development and growth of S. lycidas. The results showed that temperature had significant effects on the embryonic development and larval growth of S. lycidas (P < 0.05). The suitable temperature for hatching ranged from 21 degrees C to 30 degrees C, and the optimum temperature was 24 degrees C. At the optimum temperature, the hatching rate was (93.3 +/- 2.9)%, incubation period was (24.33 +/- 0.58) d, hatching period was (6.00 +/- 1.00) d, completely absorked rate of yolk sac was (96.4 +/- 3.1)%, and newly hatched larvae mass was (0.258 +/- 0.007) g. The effective accumulated temperature model was N = 284.42/(T-12.57). The suitable temperature for the larval survival and growth ranged from 21 degrees C to 30 degrees C, and the optimum temperature was from 24 degrees C to 27 degrees C. At the optimum temperature, the survival rate ranged from 70.0% to 73.3%, and the specific growth rate was from 2.4% to 3.8%.

To What Extent and Under Which Circumstances Are Growth Mind-Sets Important to Academic Achievement? Two Meta-Analyses.

PubMed

Sisk, Victoria F; Burgoyne, Alexander P; Sun, Jingze; Butler, Jennifer L; Macnamara, Brooke N

2018-04-01

Mind-sets (aka implicit theories) are beliefs about the nature of human attributes (e.g., intelligence). The theory holds that individuals with growth mind-sets (beliefs that attributes are malleable with effort) enjoy many positive outcomes-including higher academic achievement-while their peers who have fixed mind-sets experience negative outcomes. Given this relationship, interventions designed to increase students' growth mind-sets-thereby increasing their academic achievement-have been implemented in schools around the world. In our first meta-analysis ( k = 273, N = 365,915), we examined the strength of the relationship between mind-set and academic achievement and potential moderating factors. In our second meta-analysis ( k = 43, N = 57,155), we examined the effectiveness of mind-set interventions on academic achievement and potential moderating factors. Overall effects were weak for both meta-analyses. However, some results supported specific tenets of the theory, namely, that students with low socioeconomic status or who are academically at risk might benefit from mind-set interventions.

Time-optimum packet scheduling for many-to-one routing in wireless sensor networks

USGS Publications Warehouse

Song, W.-Z.; Yuan, F.; LaHuser, R.

2007-01-01

This paper studies the WSN application scenario with periodical traffic from all sensors to a sink. We present a time-optimum and energy-efficient packet scheduling algorithm and its distributed implementation. We first give a general many-to-one packet scheduling algorithm for wireless networks, and then prove that it is time-optimum and costs max(2N(u1) - 1, N(u 0) -1) time slots, assuming each node reports one unit of data in each round. Here N(u0) is the total number of sensors, while N(u 1) denotes the number of sensors in a sink's largest branch subtree. With a few adjustments, we then show that our algorithm also achieves time-optimum scheduling in heterogeneous scenarios, where each sensor reports a heterogeneous amount of data in each round. Then we give a distributed implementation to let each node calculate its duty-cycle locally and maximize efficiency globally. In this packet scheduling algorithm, each node goes to sleep whenever it is not transceiving, so that the energy waste of idle listening is also eliminated. Finally, simulations are conducted to evaluate network performance using the Qualnet simulator. Among other contributions, our study also identifies the maximum reporting frequency that a deployed sensor network can handle. ??2006 IEEE.

Time-optimum packet scheduling for many-to-one routing in wireless sensor networks

USGS Publications Warehouse

Song, W.-Z.; Yuan, F.; LaHusen, R.; Shirazi, B.

2007-01-01

This paper studies the wireless sensor networks (WSN) application scenario with periodical traffic from all sensors to a sink. We present a time-optimum and energy-efficient packet scheduling algorithm and its distributed implementation. We first give a general many-to-one packet scheduling algorithm for wireless networks, and then prove that it is time-optimum and costs [image omitted], N(u0)-1) time slots, assuming each node reports one unit of data in each round. Here [image omitted] is the total number of sensors, while [image omitted] denotes the number of sensors in a sink's largest branch subtree. With a few adjustments, we then show that our algorithm also achieves time-optimum scheduling in heterogeneous scenarios, where each sensor reports a heterogeneous amount of data in each round. Then we give a distributed implementation to let each node calculate its duty-cycle locally and maximize efficiency globally. In this packet-scheduling algorithm, each node goes to sleep whenever it is not transceiving, so that the energy waste of idle listening is also mitigated. Finally, simulations are conducted to evaluate network performance using the Qualnet simulator. Among other contributions, our study also identifies the maximum reporting frequency that a deployed sensor network can handle.

Growth characteristics of bearberry in the Black Hills

Treesearch

Kieth E. Severson; E. Chester. Garrett

1974-01-01

Growth of bearberry varied widely between plants and between sites. Most annual growth (66 percent] occurred during June when moisture and temperature conditions were apparently optimum. Annual growth can readily be recognized by the presence of nodes and by color changes.

Impact of electro-stimulation on denitrifying bacterial growth and analysis of bacterial growth kinetics using a modified Gompertz model in a bio-electrochemical denitrification reactor.

PubMed

Liu, Hengyuan; Chen, Nan; Feng, Chuanping; Tong, Shuang; Li, Rui

2017-05-01

This study aimed to investigate the effect of electro-stimulation on denitrifying bacterial growth in a bio-electrochemical reactor, and the growth were modeled using modified Gompertz model under different current densities at three C/Ns. It was found that the similar optimum current density of 250mA/m 2 was obtained at C/N=0.75, 1.00 and 1.25, correspondingly the maximum nitrate removal efficiencies were 98.0%, 99.2% and 99.9%. Moreover, ATP content and cell membrane permeability of denitrifying bacteria were significantly increased at optimum current density. Furthermore, modified Gompertz model fitted well with the microbial growth curves, and the highest maximum growth rates (µ max ) and shorter lag time were obtained at the optimum current density for all C/Ns. This study demonstrated that the modified Gompertz model could be used for describing microbial growth under different current densities and C/Ns in a bio-electrochemical denitrification reactor, and it provided an alternative for improving the performance of denitrification process. Copyright © 2017 Elsevier Ltd. All rights reserved.

On the optimum polarizations of incoherently reflected waves

NASA Technical Reports Server (NTRS)

Van Zyl, Jakob J.; Elachi, Charles; Papas, Charles H.

1987-01-01

The Stokes scattering operator is noted to be the most useful characterization of incoherent scattering in radar imaging; the polarization that would yield an optimum amount of power received from the scatterer is obtained by assuming a knowledge of the Stokes scattering operator instead of the 2x2 scattering matrix with complex elements. It is thereby possible to find the optimum polarizations for the case in which the scatterers can only be fully characterized by their Stokes scattering operator, and the case in which the scatterer can be fully characterized by the complex 2x2 scattering matrix. It is shown that the optimum polarizations reported in the literature form the solution for a subset of a more general class of problems, so that six optimum polarizations can exist for incoherent scattering.

An evaluation of alternative selection indexes for a non-linear profit trait approaching its economic optimum.

PubMed

Martin-Collado, D; Byrne, T J; Visser, B; Amer, P R

2016-12-01

This study used simulation to evaluate the performance of alternative selection index configurations in the context of a breeding programme where a trait with a non-linear economic value is approaching an economic optimum. The simulation used a simple population structure that approximately mimics selection in dual purpose sheep flocks in New Zealand (NZ). In the NZ dual purpose sheep population, number of lambs born is a genetic trait that is approaching an economic optimum, while genetically correlated growth traits have linear economic values and are not approaching any optimum. The predominant view among theoretical livestock geneticists is that the optimal approach to select for nonlinear profit traits is to use a linear selection index and to update it regularly. However, there are some nonlinear index approaches that have not been evaluated. This study assessed the efficiency of the following four alternative selection index approaches in terms of genetic progress relative to each other: (i) a linear index, (ii) a linear index updated regularly, (iii) a nonlinear (quadratic) index, and (iv) a NLF index (nonlinear index below the optimum and then flat). The NLF approach does not reward or penalize animals for additional genetic merit beyond the trait optimum. It was found to be at least comparable in efficiency to the approach of regularly updating the linear index with short (15 year) and long (30 year) time frames. The relative efficiency of this approach was slightly reduced when the current average value of the nonlinear trait was close to the optimum. Finally, practical issues of industry application of indexes are considered and some potential practical benefits of efficient deployment of a NLF index in highly heterogeneous industries (breeds, flocks and production environments) such as in the NZ dual purpose sheep population are discussed. © 2016 Blackwell Verlag GmbH.

Study of optimum methods of optical communication

NASA Technical Reports Server (NTRS)

Harger, R. O.

1972-01-01

Optimum methods of optical communication accounting for the effects of the turbulent atmosphere and quantum mechanics, both by the semi-classical method and the full-fledged quantum theoretical model are described. A concerted effort to apply the techniques of communication theory to the novel problems of optical communication by a careful study of realistic models and their statistical descriptions, the finding of appropriate optimum structures and the calculation of their performance and, insofar as possible, comparing them to conventional and other suboptimal systems are discussed. In this unified way the bounds on performance and the structure of optimum communication systems for transmission of information, imaging, tracking, and estimation can be determined for optical channels.

Optimum insulation thickness in wood-framed homes.

Treesearch

A.E. Oviatt

1975-01-01

New design methods must be developed to reduce energy waste in buildings. This study examines an economic approach to the design of thermal insulation in the home and demonstrates graphically that an optimum point of insulation thickness occurs where total costs of insulation and energy over the useful life of a building are a minimum. The optimum thickness thus...

Near optimum digital phase locked loops.

NASA Technical Reports Server (NTRS)

Polk, D. R.; Gupta, S. C.

1972-01-01

Near optimum digital phase locked loops are derived utilizing nonlinear estimation theory. Nonlinear approximations are employed to yield realizable loop structures. Baseband equivalent loop gains are derived which under high signal to noise ratio conditions may be calculated off-line. Additional simplifications are made which permit the application of the Kalman filter algorithms to determine the optimum loop filter. Performance is evaluated by a theoretical analysis and by simulation. Theoretical and simulated results are discussed and a comparison to analog results is made.

Understanding the mathematics and science achievement and growth trajectories of high ability high school students using hierarchical linear modeling

NASA Astrophysics Data System (ADS)

Belen-Ferrer, Bellasanta

2009-12-01

This study used longitudinal data and individual, family, and academic-related matriculation variables to examine trends in initial status and growth trajectories in overall academics, mathematics, and science achievement among 224 high ability high school Asian students. Results indicate that females have an advantage in both initial status and growth rates in overall academics and science. None of the family variables entered in the models were found to be significantly related to overall academics grade point average. All available matriculation variables entered into the models explained less than or at most about half the variance in initial achievement status and growth rate in overall academics and science but not in mathematics. These results strongly imply that other factors, notably family and school and/or classroom-related variables, not measured by the ones used in the models could explain the expected variance in initial status and growth rate of the students especially in Mathematics.

Optimum shape of a blunt forebody in hypersonic flow

NASA Technical Reports Server (NTRS)

Maestrello, L.; Ting, L.

1989-01-01

The optimum shape of a blunt forebody attached to a symmetric wedge or cone is determined. The length of the forebody, its semi-thickness or base radius, the nose radius and the radius of the fillet joining the forebody to the wedge or cone are specified. The optimum shape is composed of simple curves. Thus experimental models can be built readily to investigate the utilization of aerodynamic heating for boundary layer control. The optimum shape based on the modified Newtonian theory can also serve as the preliminary shape for the numerical solution of the optimum shape using the governing equations for a compressible inviscid or viscous flow.

Online High School Achievement versus Traditional High School Achievement

ERIC Educational Resources Information Center

Blohm, Katherine E.

2017-01-01

The following study examined the question of student achievement in online charter schools and how the achievement scores of students at online charter schools compare to achievement scores of students at traditional schools. Arizona has seen explosive growth in charter schools and online charter schools. A study comparing how these two types of…

A Longitudinal Assessment of Early Acceleration of Students in Mathematics on Growth in Mathematics Achievement

ERIC Educational Resources Information Center

Ma, X.

2005-01-01

Early acceleration of students in mathematics (in the form of early access to formal abstract algebra) has been a controversial educational issue. The current study examined the rate of growth in mathematics achievement of accelerated gifted, honors, and regular students across the entire secondary years (Grades 7-12), in comparison to their…

Warmth and Demand: The Relation between Students' Perceptions of the Classroom Environment and Achievement Growth

ERIC Educational Resources Information Center

Sandilos, Lia E.; Rimm-Kaufman, Sara E.; Cohen, Julia J.

2017-01-01

Theory suggests that African American students benefit from warm and demanding teachers. This study examines the relation between students' perceptions of 634 teachers' warm demander characteristics and achievement growth in fourth and fifth grades (M[subscript student age] = 9-11.5 years). Analyses explored whether relations were moderated by the…

Simpler Alternative to an Optimum FQPSK-B Viterbi Receiver

NASA Technical Reports Server (NTRS)

Lee, Dennis; Simon, Marvin; Yan, Tsun-Yee

2003-01-01

A reduced-complexity alternative to an optimum FQPSK-B Viterbi receiver has been invented. As described, the reduction in complexity is achieved at the cost of only a small reduction in power performance [performance expressed in terms of a bit-energy-to-noise-energy ratio (Eb/N0) for a given bit-error rate (BER)]. The term "FQPSK-B" denotes a baseband-filtered version of Feher quadrature-phase-shift keying, which is a patented, bandwidth-efficient phase-modulation scheme named after its inventor. Heretofore, commercial FQPSK-B receivers have performed symbol-by-symbol detection, in each case using a detection filter (either the proprietary FQPSK-B filter for better BER performance, or a simple integrate-and-dump filter with degraded performance) and a sample-and-hold circuit.

Promiscuous plasmid replication in thermophiles: Use of a novel hyperthermophilic replicon for genetic manipulation of Clostridium thermocellum at its optimum growth temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Groom, Joseph; Chung, Daehwan; Olson, Daniel G.

2016-01-29

Clostridium thermocellum is a leading candidate for the consolidated bioprocessing of lignocellulosic biomass for the production of fuels and chemicals. A limitation to the engineering of this strain is the availability of stable replicating plasmid vectors for homologous and heterologous expression of genes that provide improved and/or novel pathways for fuel production. Current vectors relay on replicons from mesophilic bacteria and are not stable at the optimum growth temperature of C. thermocellum. To develop more thermostable genetic tools for C. thermocellum, we constructed vectors based on the hyperthermophilic Caldicellulosiruptor bescii replicon pBAS2. Autonomously replicating shuttle vectors based on pBAS2 reproduciblymore » transformed C. thermocellum at 60 °C and were maintained in multiple copy. Promoters, selectable markers and plasmid replication proteins from C. bescii were functional in C. thermocellum. Phylogenetic analyses of the proteins contained on pBAS2 revealed that the replication initiation protein RepL is unique among thermophiles. Lastly, these results suggest that pBAS2 may be a broadly useful replicon for other thermophilic Firmicutes.« less

Is green economy achievable through championing green growth? A local government experience from Zambia

PubMed Central

2016-01-01

The need to enhance environmental sustainability, sustainable development and growth that takes into account the well-being of the people and nature because of the increased production and consumption of goods and services is the major driver to the introduction of green economy in Zambia and countries in southern Africa. This article examines the extent to which local government in Zambia has embraced green growth and green economy and critically analyses the concept of green economy and green growth. This study is based on a review of planning and policy documents, a household questionnaire survey and interviews with various institutions, planners and rural development organisations. A number of policies implemented at the local government level were analysed and reflected upon irrespective of whether they contain the components of green growth and green economy and the extent to which they contribute to attaining green economy. The article argues that the need for economic diversification is important as far as green economy is concerned. The article recommends the need to invest in research and development in order to find more carbon-free economic activities. The conclusion is that local government is key to achieving green growth and green economy, because it is involved at all levels, from policy formulation to implementation.

Optimum performance and potential flow field of hovering rotors

NASA Technical Reports Server (NTRS)

Wu, J. C.; Sigman, R. K.

1975-01-01

Rotor and propeller performance and induced potential flowfields were studied on the basis of a rotating actuator disk concept, with special emphasis on rotors hovering out of ground effect. A new theory for the optimum performance of rotors hovering OGE is developed and presented. An extended theory for the optimum performance of rotors and propellers in axial motion is also presented. Numerical results are presented for the optimum distributions of blade-bound circulation together with axial inflow and ultimate wake velocities for the hovering rotor over the range of thrust coefficient of interest in rotorcraft applications. Shapes of the stream tubes and of the velocities in the slipstream are obtained, using available methods, for optimum and off-optimum circulation distributions for rotors hovering in and out of ground effect. A number of explicit formulae useful in computing rotor and propeller induced flows are presented for stream functions and velocities due to distributions of circular vortices over axi-symmetric surfaces.

Optimum filters for narrow-band frequency modulation.

NASA Technical Reports Server (NTRS)

Shelton, R. D.

1972-01-01

The results of a computer search for the optimum type of bandpass filter for low-index angle-modulated signals are reported. The bandpass filters are discussed in terms of their low-pass prototypes. Only filter functions with constant numerators are considered. The pole locations for the optimum filters of several cases are shown in a table. The results are fairly independent of modulation index and bandwidth.

50 CFR 648.20 - Maximum optimum yield (OYs).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Maximum optimum yield (OYs). 648.20 Section 648.20 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Measures for the Atlantic Mackerel, Squid, and Butterfish Fisheries § 648.20 Maximum optimum yield (OYs...

Influence of irrigation during the growth stage on yield and quality in mango (Mangifera indica L).

PubMed

Wei, Junya; Liu, Guoyin; Liu, Debing; Chen, Yeyuan

2017-01-01

Although being one of the few drought-tolerant plants, mango trees are irrigated to ensure optimum and consistent productivity in China. In order to better understand the effects of soil water content on mango yield and fruit quality at fruit growth stage, irrigation experiments were investigated and the object was to determine the soil water content criteria at which growth and quality of mango would be optimal based on soil water measured by RHD-JS water-saving irrigation system through micro-sprinkling irrigation. Five soil water content treatments (relative to the percentage of field water capacity) for irrigation (T1:79%-82%, T2:75%-78%, T3:71%-74%, T4: 65%-70%, T5:63%-66%) were compared in 2013. Amount of applied irrigation water for different treatments varied from 2.93m3 to 1.08 m3. The results showed that mango fruit production and quality at fruit growth stage were significantly affected under different irrigation water amounts. Variation in soil water content not only had effects on fruit size, but also on fruit yield. The highest fruit yield and irrigation water use efficiency were obtained from the T4 treatment. Irrigation water amount also affected fruit quality parameters like fruit total soluble solids, soluble sugar, starch, titratable acid and vitamin C content. Comprehensive evaluation of the effect of indexs of correlation on irrigation treatment by subordinate function showed that when the soil moisture content were controlled at about 65-70% of the field water moisture capacity, water demand in the growth and development of mango could be ensured, and maximum production efficiency of irrigation and the best quality of fruit could be achieved. In conclusion, treatment T4 was the optimum irrigation schedule for growing mango, thus achieving efficient production of mango in consideration of the compromise among mango yield, fruit quality and water use efficiency.

Predicting Long-Term Growth in Students' Mathematics Achievement: The Unique Contributions of Motivation and Cognitive Strategies

ERIC Educational Resources Information Center

Murayama, Kou; Pekrun, Reinhard; Lichtenfeld, Stephanie; vom Hofe, Rudolf

2013-01-01

This research examined how motivation (perceived control, intrinsic motivation, and extrinsic motivation), cognitive learning strategies (deep and surface strategies), and intelligence jointly predict long-term growth in students' mathematics achievement over 5 years. Using longitudinal data from six annual waves (Grades 5 through 10;…

[Optimum harvest time of Tulipa edulis based on comparison of biomass accumulation and medicinal quality evaluation].

PubMed

Yang, Xiao-Hua; Guo, Qiao-Sheng; Zhu, Zai-Biao; Lin, Jian-Luo; Miao, Yuan-Yuan; Sun, Yuan

2016-02-01

The optimum harvest time of Tulipa edulis was explored based on biomass accumulation and medicinal quality evaluation. Samples were taken from bud stage (Feb 13th) to dormancy stage (May 14th) and the growth indexes, organs biomasses, drying rate, contents of water-soluble extract and polysaccharides were determined. The results showed that biomass distribution of T. edulis varied with growth center and the bulb gained maximum biomass allocation in the whole growth period. The total biomass accumulation and bulb biomass accumulation　increased in the whole growth period and peaked in fructescence stage. No differences were observed in bulb biomass among fructescence stage, withering stage and dormancy stage. The correlation between bulb biomass allocation and other morphological indexes varied with the harvest time. Bulb dry weight biomass had negative correlation with some morphological indexes of aerial part of T. edulis at bud stage, flower stage and fructescence and had significant positive (P<0.05) or extremely significant positive correlation（P<0.01）with other morphological indexes except for root at bearing fruits stage. The drying rate of bulb of T. edulis increased with the extension of harvest time and peaked in dormancy stage. The water-soluble extract of T. edulis bulb was the highest in pre-growing-stage. The tendency of polysaccharides contents showed a W-shape variation during the harvesting period. The polysaccharides content was the lowest in fructescence stage and was the highest in dormancy stage. Considering the yield and medicinal quality of T. edulis bulb, the optimum harvest time of T. edulis is in the withering stage or early stage of dormancy. Copyright© by the Chinese Pharmaceutical Association.

Optimum viewing distance for target acquisition

NASA Astrophysics Data System (ADS)

Holst, Gerald C.

2015-05-01

Human visual system (HVS) "resolution" (a.k.a. visual acuity) varies with illumination level, target characteristics, and target contrast. For signage, computer displays, cell phones, and TVs a viewing distance and display size are selected. Then the number of display pixels is chosen such that each pixel subtends 1 min-1. Resolution of low contrast targets is quite different. It is best described by Barten's contrast sensitivity function. Target acquisition models predict maximum range when the display pixel subtends 3.3 min-1. The optimum viewing distance is nearly independent of magnification. Noise increases the optimum viewing distance.

Hardware-Based Non-Optimum Factors for Launch Vehicle Structural Design

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Cerro, Jeffrey A.

2010-01-01

During aerospace vehicle conceptual and preliminary design, empirical non-optimum factors are typically applied to predicted structural component weights to account for undefined manufacturing and design details. Non-optimum factors are developed here for 32 aluminum-lithium 2195 orthogrid panels comprising the liquid hydrogen tank barrel of the Space Shuttle External Tank using measured panel weights and manufacturing drawings. Minimum values for skin thickness, axial and circumferential blade stiffener thickness and spacing, and overall panel thickness are used to estimate individual panel weights. Panel non-optimum factors computed using a coarse weights model range from 1.21 to 1.77, and a refined weights model (including weld lands and skin and stiffener transition details) yields non-optimum factors of between 1.02 and 1.54. Acreage panels have an average 1.24 non-optimum factor using the coarse model, and 1.03 with the refined version. The observed consistency of these acreage non-optimum factors suggests that relatively simple models can be used to accurately predict large structural component weights for future launch vehicles.

Optimum Multi-Impulse Rendezvous Program

NASA Technical Reports Server (NTRS)

Glandorf, D. R.; Onley, A. G.; Rozendaal, H. L.

1970-01-01

OMIRPROGRAM determines optimal n-impulse rendezvous trajectories under the restrictions of two-body motion in free space. Lawden's primer vector theory is applied to determine optimum number of midcourse impulse applications. Global optimality is not guaranteed.

Warmth and Demand: The Relation between Students' Perceptions of The Classroom Environment and Achievement Growth

ERIC Educational Resources Information Center

Sandilos, Lia E.; Rimm-Kaufman, Sara E.; Cohen, Julia Jackson

2017-01-01

Theory suggests that African American students benefit from warm and demanding teachers. This study examines the relation between students' perceptions of 634 teachers' warm demander characteristics and achievement growth in fourth and fifth grades (M[subscript student age] = 9-11.5 years). Analyses explored whether relations were moderated by the…

A class of optimum digital phase locked loops

NASA Technical Reports Server (NTRS)

Kumar, R.; Hurd, W. J.

1986-01-01

This paper presents a class of optimum digital filters for digital phase locked loops, for the important case in which the maximum update rate of the loop filter and numerically controlled oscillator (NCO) is limited. This case is typical when the loop filter is implemented in a microprocessor. In these situations, pure delay is encountered in the loop transfer function and thus the stability and gain margin of the loop are of crucial interest. The optimum filters designed for such situations are evaluated in terms of their gain margin for stability, dynamic error, and steady-state error performance. For situations involving considerably high phase dynamics an adaptive and programmable implementation is also proposed to obtain an overall optimum strategy.

Effect of Light Intensity for Optimum Biomass and Lipid Production from Scenedesmus dimorphus (Turpin) Kützing

NASA Astrophysics Data System (ADS)

Kurniawati, F. N.; Mahajoeno, E.; Sunarto; Sari, S. L. A.

2017-07-01

One source of alternative energy substitute for petroleum raw materials is renewable vegetable oils known as biodiesel. Biodiesel can be produced from microalgae, since it was more efficient and environmentally friendly. Scenedesmus dimorphus (Turpin) Kützing was developed as a source of biodiesel since it had potential of high lipid production. The aims of this research were to know the rate of growth of Scenedesmus dimorphus in different lighting and the optimimum light intensity for biomass and lipid production. This research used a completely randomized design consisting of 3 treatments with 3 replications. Treatments in this research were the light intensity, i.e. 7,500, 10,000, and 12,500 lux. Scenedesmus dimorphus was grew in Bold’s Basal Medium (BBM). Parameters observed in this research were the cell number, biomass and lipid production of S. dimorphus. Data were analyzed by ANOVA followed by DMRT 5%. The results showed that the optimum growth rate of S. dimorphus was in the intensity of 12,500 lux that was 100.80 x 106 cells.ml-1. The optimum production of biomass and lipids was in treatment 12,500 lux i.e; 1.1407 g.L-1 and 0.2520 g.L-1 (22.28% dry weight).

Optimum testing of multiple hypotheses in quantum detection theory

NASA Technical Reports Server (NTRS)

Yuen, H. P.; Kennedy, R. S.; Lax, M.

1975-01-01

The problem of specifying the optimum quantum detector in multiple hypotheses testing is considered for application to optical communications. The quantum digital detection problem is formulated as a linear programming problem on an infinite-dimensional space. A necessary and sufficient condition is derived by the application of a general duality theorem specifying the optimum detector in terms of a set of linear operator equations and inequalities. Existence of the optimum quantum detector is also established. The optimality of commuting detection operators is discussed in some examples. The structure and performance of the optimal receiver are derived for the quantum detection of narrow-band coherent orthogonal and simplex signals. It is shown that modal photon counting is asymptotically optimum in the limit of a large signaling alphabet and that the capacity goes to infinity in the absence of a bandwidth limitation.

Optimum angle-cut of collimator for dense objects in high-energy proton radiography

NASA Astrophysics Data System (ADS)

Xu, Hai-Bo; Zheng, Na

2016-02-01

The use of minus identity lenses with an angle-cut collimator can achieve high contrast images in high-energy proton radiography. This article presents the principles of choosing the angle-cut aperture of the collimator for different energies and objects. Numerical simulation using the Monte Carlo code Geant4 has been implemented to investigate the entire radiography for the French test object. The optimum angle-cut apertures of the collimators are also obtained for different energies. Supported by NSAF (11176001) and Science and Technology Developing Foundation of China Academy of Engineering Physics (2012A0202006)

[Optimum design of imaging spectrometer based on toroidal uniform-line-spaced (TULS) spectrometer].

PubMed

Xue, Qing-Sheng; Wang, Shu-Rong

2013-05-01

Based on the geometrical aberration theory, a optimum-design method for designing an imaging spectrometer based on toroidal uniform grating spectrometer is proposed. To obtain the best optical parameters, twice optimization is carried out using genetic algorithm(GA) and optical design software ZEMAX A far-ultraviolet(FUV) imaging spectrometer is designed using this method. The working waveband is 110-180 nm, the slit size is 50 microm x 5 mm, and the numerical aperture is 0.1. Using ZEMAX software, the design result is analyzed and evaluated. The results indicate that the MTF for different wavelengths is higher than 0.7 at Nyquist frequency 10 lp x mm(-1), and the RMS spot radius is less than 14 microm. The good imaging quality is achieved over the whole working waveband, the design requirements of spatial resolution 0.5 mrad and spectral resolution 0.6 nm are satisfied. It is certificated that the optimum-design method proposed in this paper is feasible. This method can be applied in other waveband, and is an instruction method for designing grating-dispersion imaging spectrometers.

Long term follow-up for small pure ground-glass nodules: implications of determining an optimum follow-up period and high-resolution CT findings to predict the growth of nodules.

PubMed

Takahashi, Shotaro; Tanaka, Nobuyuki; Okimoto, Tomoaki; Tanaka, Toshiki; Ueda, Kazuhiro; Matsumoto, Tsuneo; Ashizawa, Kazuto; Kunihiro, Yoshie; Kido, Shoji; Matsunaga, Naofumi

2012-04-01

To identify the optimum follow-up period for pure ground-glass nodules (GGN) measuring less than 15 mm in diameter, and to evaluate whether the initial HRCT findings can be used as predictors for the progression of pure GGN. A total of 150 pure GGNs present in 111 patients were evaluated. The series of HRCT images for each GGN at the time of the initial detection, 2 years after detection, and at the final follow-up were evaluated. The HRCT findings of GGN were compared between the "increasing nodule" and "non-increasing nodule" groups. Most (87.3%) pure GGN did not increase whereas some nodules (12.7%) eventually increased after long-term follow-up (mean 66.0 ± 25.0 months). Six (31.6%) out of the 19 increasing nodules were regarded as stable at the 2 year follow-up examination. Some morphological findings on initial HRCT, including a size greater than 10 mm (p = 0.001), lobulated margins (p = 0.015), and a bubble-like appearance (p = 0.002), were significantly associated with the growth of pure GGNs. More than 2 years of follow-up are necessary to detect the growth of pure GGNs. Some characteristic findings indicated a high likelihood of future growth of the GGN.

A Parallel Approach To Optimum Actuator Selection With a Genetic Algorithm

NASA Technical Reports Server (NTRS)

Rogers, James L.

2000-01-01

Recent discoveries in smart technologies have created a variety of aerodynamic actuators which have great potential to enable entirely new approaches to aerospace vehicle flight control. For a revolutionary concept such as a seamless aircraft with no moving control surfaces, there is a large set of candidate locations for placing actuators, resulting in a substantially larger number of combinations to examine in order to find an optimum placement satisfying the mission requirements. The placement of actuators on a wing determines the control effectiveness of the airplane. One approach to placement Maximizes the moments about the pitch, roll, and yaw axes, while minimizing the coupling. Genetic algorithms have been instrumental in achieving good solutions to discrete optimization problems, such as the actuator placement problem. As a proof of concept, a genetic has been developed to find the minimum number of actuators required to provide uncoupled pitch, roll, and yaw control for a simplified, untapered, unswept wing model. To find the optimum placement by searching all possible combinations would require 1,100 hours. Formulating the problem and as a multi-objective problem and modifying it to take advantage of the parallel processing capabilities of a multi-processor computer, reduces the optimization time to 22 hours.

Implementation of optimum solar electricity generating system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Balbir Singh Mahinder, E-mail: balbir@petronas.com.my; Karim, Samsul Ariffin A., E-mail: samsul-ariffin@petronas.com.my; Sivapalan, Subarna, E-mail: subarna-sivapalan@petronas.com.my

2014-10-24

Under the 10{sup th} Malaysian Plan, the government is expecting the renewable energy to contribute approximately 5.5% to the total electricity generation by the year 2015, which amounts to 98MW. One of the initiatives to ensure that the target is achievable was to establish the Sustainable Energy Development Authority of Malaysia. SEDA is given the authority to administer and manage the implementation of the feed-in tariff (FiT) mechanism which is mandated under the Renewable Energy Act 2011. The move to establish SEDA is commendable and the FiT seems to be attractive but there is a need to create awareness onmore » the implementation of the solar electricity generating system (SEGS). In Malaysia, harnessing technologies related to solar energy resources have great potential for implementation. However, the main issue that plagues the implementation of SEGS is the intermittent nature of this source of energy. The availability of sunlight is during the day time, and there is a need for electrical energy storage system, so that there is electricity available during the night time as well. The meteorological condition such as clouds, haze and pollution affects the SEGS as well. The PV based SEGS is seems to be promising electricity generating system that can contribute towards achieving the 5.5% target and will be able to minimize the negative effects of utilizing fossil fuels for electricity generation on the environment. Malaysia is committed to Kyoto Protocol, which emphasizes on fighting global warming by achieving stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. In this paper, the technical aspects of the implementation of optimum SEGS is discussed, especially pertaining to the positioning of the PV panels.« less

Implementation of optimum solar electricity generating system

NASA Astrophysics Data System (ADS)

Singh, Balbir Singh Mahinder; Sivapalan, Subarna; Najib, Nurul Syafiqah Mohd; Menon, Pradeep; Karim, Samsul Ariffin A.

2014-10-01

Under the 10th Malaysian Plan, the government is expecting the renewable energy to contribute approximately 5.5% to the total electricity generation by the year 2015, which amounts to 98MW. One of the initiatives to ensure that the target is achievable was to establish the Sustainable Energy Development Authority of Malaysia. SEDA is given the authority to administer and manage the implementation of the feed-in tariff (FiT) mechanism which is mandated under the Renewable Energy Act 2011. The move to establish SEDA is commendable and the FiT seems to be attractive but there is a need to create awareness on the implementation of the solar electricity generating system (SEGS). In Malaysia, harnessing technologies related to solar energy resources have great potential for implementation. However, the main issue that plagues the implementation of SEGS is the intermittent nature of this source of energy. The availability of sunlight is during the day time, and there is a need for electrical energy storage system, so that there is electricity available during the night time as well. The meteorological condition such as clouds, haze and pollution affects the SEGS as well. The PV based SEGS is seems to be promising electricity generating system that can contribute towards achieving the 5.5% target and will be able to minimize the negative effects of utilizing fossil fuels for electricity generation on the environment. Malaysia is committed to Kyoto Protocol, which emphasizes on fighting global warming by achieving stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. In this paper, the technical aspects of the implementation of optimum SEGS is discussed, especially pertaining to the positioning of the PV panels.

Study on the optimum PCM melting temperature for energy savings in residential buildings worldwide

NASA Astrophysics Data System (ADS)

Saffari, M.; de Gracia, A.; Fernández, C.; Zsembinszki, G.; Cabeza, L. F.

2017-10-01

To maintain comfort conditions in residential buildings along a full year period, the use of active systems is generally required to either supply heating or cooling. The heating and cooling demands strongly depend on the climatic conditions, type of building and occupants’ behaviour. The overall annual energy consumption of the building can be reduced by the use of renewable energy sources and/or passive systems. The use of phase change materials (PCM) as passive systems in buildings enhances the thermal mass of the envelope, and reduces the indoor temperature fluctuations. As a consequence, the overall energy consumption of the building is generally lower as compared to the case when no PCM systems are used. The selection of the PCM melting temperature is a key issue to reduce the energy consumption of the buildings. The main focus of this study is to determine the optimum PCM melting temperature for passive heating and cooling according to different weather conditions. To achieve that, numerical simulations were carried out using EnergyPlus v8.4 coupled with GenOpt® v3.1.1 (a generic optimization software). A multi-family residential apartment was selected from ASHRAE Standard 90.1- 2013 prototype building model, and different climate conditions were considered to determine the optimum melting temperature (in the range from 20ºC to 26ºC) of the PCM contained in gypsum panels. The results confirm that the optimum melting temperature of the PCM strongly depends on the climatic conditions. In general, in cooling dominant climates the optimum PCM temperature is around 26ºC, while in heating dominant climates it is around 20ºC. Furthermore, the results show that an adequate selection of the PCM as passive system in building envelope can provide important energy savings for both heating dominant and cooling dominant regions.

Modeling determinants of growth: evidence for a community-based target in height?

PubMed

Aßmann, Christian; Hermanussen, Michael

2013-07-01

Human growth is traditionally envisaged as a target-seeking process regulated by genes, nutrition, health, and the state of an individual's social and economic environment; it is believed that under optimal physical conditions, an individual will achieve his or her full genetic potential. Using a panel data set on individual height increments, we suggest a statistical modeling approach that characterizes growth as first-order trend stationary and allows for controlling individual growth tempo via observable measures of individual maturity. A Bayesian framework and corresponding Markov-chain Monte Carlo techniques allowing for a conceptually stringent treatment of missing values are adapted for parameter estimation. The model provides evidence for the adjustment of the individual growth rate toward average height of the population. The increase in adult body height during the past 150 y has been explained by the steady improvement of living conditions that are now being considered to have reached an optimum in Western societies. The current investigation questions the notion that the traditional concept in the understanding of this target-seeking process is sufficient. We consider an additional regulator that possibly points at community-based target seeking in growth.

Performance characteristics of aerodynamically optimum turbines for wind energy generators

NASA Technical Reports Server (NTRS)

Rohrbach, C.; Worobel, R.

1975-01-01

This paper presents a brief discussion of the aerodynamic methodology for wind energy generator turbines, an approach to the design of aerodynamically optimum wind turbines covering a broad range of design parameters, some insight on the effect on performance of nonoptimum blade shapes which may represent lower fabrication costs, the annual wind turbine energy for a family of optimum wind turbines, and areas of needed research. On the basis of the investigation, it is concluded that optimum wind turbines show high performance over a wide range of design velocity ratios; that structural requirements impose constraints on blade geometry; that variable pitch wind turbines provide excellent power regulation and that annual energy output is insensitive to design rpm and solidity of optimum wind turbines.

Liquid phase electroepitaxial bulk growth of binary and ternary alloy semiconductors under external magnetic field

NASA Astrophysics Data System (ADS)

Sheibani, Hamdi

2002-01-01

Liquid Phase Electroepitaxy (LPEE) and is a relatively new, promising technique for producing high quality, thick compound semiconductors and their alloys. The main objectives are to reduce the adverse effect of natural convection and to determine the optimum growth conditions for reproducible desired crystals for the optoelectronic and electronic device industry. Among the available techniques for suppressing the adverse effect of natural convection, the application of an external magnetic field seems the most feasible one. The research work in this dissertation consists of two parts. The first part is focused on the design and development of a state of the art LPEE facility with a novel crucible design, that can produce bulk crystals of quality higher than those achieved by the existing LPEE system. A growth procedure was developed to take advantage of this novel crucible design. The research of the growth of InGaAs single crystals presented in this thesis will be a basis for the future LPEE growth of other important material and is an ideal vehicle for the development of a ternary crystal growth process. The second part of the research program is the experimental study of the LPEE growth process of high quality bulk single crystals of binary/ternary semiconductors under applied magnetic field. The compositional uniformity of grown crystals was measured by Electron Probe Micro-analysis (EPMA) and X-ray microanalysis. The state-of-the-art LPEE system developed at University of Victoria, because of its novel design features, has achieved a growth rate of about 4.5 mm/day (with the application of an external fixed magnetic field of 4.5 KGauss and 3 A/cm2 electric current density), and a growth rate of about 11 mm/day (with 4.5 KGauss magnetic field and 7 A/cm2 electric current density). This achievement is simply a breakthrough in LPEE, making this growth technique absolutely a bulk growth technique and putting it in competition with other bulk growth techniques

Optimum performance of hovering rotors

NASA Technical Reports Server (NTRS)

Wu, J. C.; Goorjian, P. M.

1972-01-01

A theory for the optimum performance of a rotor hovering out of ground effect is developed. The performance problem is formulated using general momentum theory for an infinitely bladed rotor, and the effect of a finite number of blades is estimated. The analysis takes advantage of the fact that a simple relation exists between the radial distributions of static pressure and angular velocity in the ultimate wake, far downstream of the rotor, since the radial velocity vanishes there. This relation permits the establishment of an optimum performance criterion in terms of the ultimate wake velocities by introducing a small local perturbation of the rotational velocity and requiring the resulting ratio of thrust and power changes to be independent of the radial location of the perturbation. This analysis fully accounts for the changes in static pressure distribution and axial velocity distribution throughout the wake as the result of the local perturbation of the rotational velocity component.

Method for Determining Optimum Injector Inlet Geometry

NASA Technical Reports Server (NTRS)

Myers, W. Neill (Inventor); Trinh, Huu P. (Inventor)

2015-01-01

A method for determining the optimum inlet geometry of a liquid rocket engine swirl injector includes obtaining a throttleable level phase value, volume flow rate, chamber pressure, liquid propellant density, inlet injector pressure, desired target spray angle and desired target optimum delta pressure value between an inlet and a chamber for a plurality of engine stages. The method calculates the tangential inlet area for each throttleable stage. The method also uses correlation between the tangential inlet areas and delta pressure values to calculate the spring displacement and variable inlet geometry of a liquid rocket engine swirl injector.

Culture Conditions for Mycelial Growth of Coriolus versicolor

PubMed Central

Kang, Min-Jin; Choi, Seong-Yong; Yoo, Young-Bok; Seok, Soon-Ja; Jung, Hee-Young

2010-01-01

Coriolus versicolor, is one of the most popular medicinal mushrooms due its various biologically active components. This study was conducted to obtain basic information regarding the mycelial culture conditions of C. versicolor. Based on the culture, and MCM media were suitable for the mycelial growth of the mushroom. The optimum carbon and nitrogen sources were dextrin and yeast extract, respectively, and the optimum C/N ratio was 10 to 2 when 2% glucose was used. Other minor components required for optimal growth included thiamine-HCl and biotin as vitamins, succinic acid, lactic acid and citric acid as organic acids, as well as MgSO4·7H2O as mineral salts. PMID:23956654

Culture Conditions for Mycelial Growth of Coriolus versicolor.

PubMed

Jo, Woo-Sik; Kang, Min-Jin; Choi, Seong-Yong; Yoo, Young-Bok; Seok, Soon-Ja; Jung, Hee-Young

2010-09-01

Coriolus versicolor, is one of the most popular medicinal mushrooms due its various biologically active components. This study was conducted to obtain basic information regarding the mycelial culture conditions of C. versicolor. Based on the culture, and MCM media were suitable for the mycelial growth of the mushroom. The optimum carbon and nitrogen sources were dextrin and yeast extract, respectively, and the optimum C/N ratio was 10 to 2 when 2% glucose was used. Other minor components required for optimal growth included thiamine-HCl and biotin as vitamins, succinic acid, lactic acid and citric acid as organic acids, as well as MgSO4·7H2O as mineral salts.

Identification of Limiting Factors for the Optimum Growth of Fusarium Oxysporum in Liquid Medium

PubMed Central

Srivastava, Shilpi; Pathak, Neelam; Srivastava, Prachi

2011-01-01

Fusarium oxysporum is a highly ubiquitous species that infects a wide range of hosts causing various diseases such as vascular wilts, yellows, rots, and damping-off. Despite the immense economic significance of this phytopathogen, few workers have reported growth studies in this genus in submerged culture. In the present study, several parameters such as change in media pH, biomass, pattern of substrate utilization, viability of the fungal cells, and protein content were observed over a period of time. The fungal biomass increased at a slow rate for the initial 48 h and thereafter increased at an exponential rate. However, after about 8 days the rapid growth stabilized and the trend became more toward stationary phase. The concentration of glucose in the liquid media decreased rapidly up to the initial 4 days, followed by a slow decrease. The pH of the medium gradually decreased as the fungal growth progressed, the reduction being more pronounced in the initial 48 h. This study would be of immense importance for utilization of F. oxysporum for diverse applications because we can predict the growth pattern in the fungus and modulate its growth for human benefit. PMID:21976815

A Novel Method of Supplying Nutrients Permits Predictable Shoot Growth and Root : Shoot Ratios of Pre-transplant Bedding Plants

PubMed Central

Greenwood, Duncan J.; Mckee, John M. T.; Fuller, Deborah P.; Burns, Ian G.; Mulholland, Barry J.

2007-01-01

Background and Aims Growth of bedding plants, in small peat plugs, relies on nutrients in the irrigation solution. The object of the study was to find a way of modifying the nutrient supply so that good-quality seedlings can be grown rapidly and yet have the high root : shoot ratios essential for efficient transplanting. Methods A new procedure was devised in which the concentrations of nutrients in the irrigation solution were modified during growth according to changing plant demand, instead of maintaining the same concentrations throughout growth. The new procedure depends on published algorithms for the dependence of growth rate and optimal plant nutrient concentrations on shoot dry weight Ws (g m−2), and on measuring evapotranspiration rates and shoot dry weights at weekly intervals. Pansy, Viola tricola ‘Universal plus yellow’ and petunia, Petunia hybrida ‘Multiflora light salmon vein’ were grown in four independent experiments with the expected optimum nutrient concentration and fractions of the optimum. Root and shoot weights were measured during growth. Key Results For each level of nutrient supply Ws increased with time (t) in days, according to the equation ΔWs/Δt=K2Ws/(100+Ws) in which the growth rate coefficient (K2) remained approximately constant throughout growth. The value of K2 for the optimum treatment was defined by incoming radiation and temperature. The value of K2 for each sub-optimum treatment relative to that for the optimum treatment was logarithmically related to the sub-optimal nutrient supply. Provided the aerial environment was optimal, Rsb/Ro≈Wo/Wsb where R is the root : shoot ratio, W is the shoot dry weight, and sb and o indicate sub-optimum and optimum nutrient supplies, respectively. Sub-optimal nutrient concentrations also depressed shoot growth without appreciably affecting root growth when the aerial environment was non-limiting. Conclusion The new procedure can predict the effects of nutrient supply

Optimum Design of Aerospace Structural Components Using Neural Networks

NASA Technical Reports Server (NTRS)

Berke, L.; Patnaik, S. N.; Murthy, P. L. N.

1993-01-01

The application of artificial neural networks to capture structural design expertise is demonstrated. The principal advantage of a trained neural network is that it requires a trivial computational effort to produce an acceptable new design. For the class of problems addressed, the development of a conventional expert system would be extremely difficult. In the present effort, a structural optimization code with multiple nonlinear programming algorithms and an artificial neural network code NETS were used. A set of optimum designs for a ring and two aircraft wings for static and dynamic constraints were generated using the optimization codes. The optimum design data were processed to obtain input and output pairs, which were used to develop a trained artificial neural network using the code NETS. Optimum designs for new design conditions were predicted using the trained network. Neural net prediction of optimum designs was found to be satisfactory for the majority of the output design parameters. However, results from the present study indicate that caution must be exercised to ensure that all design variables are within selected error bounds.

Experimental investigation of optimum beam size for FSO uplink

NASA Astrophysics Data System (ADS)

Kaushal, Hemani; Kaddoum, Georges; Jain, Virander Kumar; Kar, Subrat

2017-10-01

In this paper, the effect of transmitter beam size on the performance of free space optical (FSO) communication has been determined experimentally. Irradiance profile for varying turbulence strength is obtained using optical turbulence generating (OTG) chamber inside laboratory environment. Based on the results, an optimum beam size is investigated using the semi-analytical method. Moreover, the combined effects of atmospheric scintillation and beam wander induced pointing errors are considered in order to determine the optimum beam size that minimizes the bit error rate (BER) of the system for a fixed transmitter power and link length. The results show that the optimum beam size for FSO uplink depends upon Fried parameter and outer scale of the turbulence. Further, it is observed that the optimum beam size increases with the increase in zenith angle but has negligible effect with the increase in fade threshold level at low turbulence levels and has a marginal effect at high turbulence levels. Finally, the obtained outcome is useful for FSO system design and BER performance analysis.

Monte-Carlo modelling to determine optimum filter choices for sub-microsecond optical pyrometry.

PubMed

Ota, Thomas A; Chapman, David J; Eakins, Daniel E

2017-04-01

When designing a spectral-band pyrometer for use at high time resolutions (sub-μs), there is ambiguity regarding the optimum characteristics for a spectral filter(s). In particular, while prior work has discussed uncertainties in spectral-band pyrometry, there has been little discussion of the effects of noise which is an important consideration in time-resolved, high speed experiments. Using a Monte-Carlo process to simulate the effects of noise, a model of collection from a black body has been developed to give insights into the optimum choices for centre wavelength and passband width. The model was validated and then used to explore the effects of centre wavelength and passband width on measurement uncertainty. This reveals a transition centre wavelength below which uncertainties in calculated temperature are high. To further investigate system performance, simultaneous variation of the centre wavelength and bandpass width of a filter is investigated. Using data reduction, the effects of temperature and noise levels are illustrated and an empirical approximation is determined. The results presented show that filter choice can significantly affect instrument performance and, while best practice requires detailed modelling to achieve optimal performance, the expression presented can be used to aid filter selection.

Investigation of earthquake factor for optimum tuned mass dampers

NASA Astrophysics Data System (ADS)

Nigdeli, Sinan Melih; Bekdaş, Gebrail

2012-09-01

In this study the optimum parameters of tuned mass dampers (TMD) are investigated under earthquake excitations. An optimization strategy was carried out by using the Harmony Search (HS) algorithm. HS is a metaheuristic method which is inspired from the nature of musical performances. In addition to the HS algorithm, the results of the optimization objective are compared with the results of the other documented method and the corresponding results are eliminated. In that case, the best optimum results are obtained. During the optimization, the optimum TMD parameters were searched for single degree of freedom (SDOF) structure models with different periods. The optimization was done for different earthquakes separately and the results were compared.

Impact of warm winters on microbial growth

NASA Astrophysics Data System (ADS)

Birgander, Johanna; Rousk, Johannes; Axel Olsson, Pål

2014-05-01

Growth of soil bacteria has an asymmetrical response to higher temperature with a gradual increase with increasing temperatures until an optimum after which a steep decline occurs. In laboratory studies it has been shown that by exposing a soil bacterial community to a temperature above the community's optimum temperature for two months, the bacterial community grows warm-adapted, and the optimum temperature of bacterial growth shifts towards higher temperatures. This result suggests a change in the intrinsic temperature dependence of bacterial growth, as temperature influenced the bacterial growth even though all other factors were kept constant. An intrinsic temperature dependence could be explained by either a change in the bacterial community composition, exchanging less tolerant bacteria towards more tolerant ones, or it could be due to adaptation within the bacteria present. No matter what the shift in temperature tolerance is due to, the shift could have ecosystem scale implications, as winters in northern Europe are getting warmer. To address the question of how microbes and plants are affected by warmer winters, a winter-warming experiment was established in a South Swedish grassland. Results suggest a positive response in microbial growth rate in plots where winter soil temperatures were around 6 °C above ambient. Both bacterial and fungal growth (leucine incorporation, and acetate into ergosterol incorporation, respectively) appeared stimulated, and there are two candidate explanations for these results. Either (i) warming directly influence microbial communities by modulating their temperature adaptation, or (ii) warming indirectly affected the microbial communities via temperature induced changes in bacterial growth conditions. The first explanation is in accordance with what has been shown in laboratory conditions (explained above), where the differences in the intrinsic temperature relationships were examined. To test this explanation the

Influence of irrigation during the growth stage on yield and quality in mango (Mangifera indica L)

PubMed Central

Wei, Junya; Liu, Guoyin; Liu, Debing; Chen, Yeyuan

2017-01-01

Although being one of the few drought-tolerant plants, mango trees are irrigated to ensure optimum and consistent productivity in China. In order to better understand the effects of soil water content on mango yield and fruit quality at fruit growth stage, irrigation experiments were investigated and the object was to determine the soil water content criteria at which growth and quality of mango would be optimal based on soil water measured by RHD-JS water-saving irrigation system through micro-sprinkling irrigation. Five soil water content treatments (relative to the percentage of field water capacity) for irrigation (T1:79%-82%, T2:75%-78%, T3:71%-74%, T4: 65%-70%, T5:63%-66%) were compared in 2013. Amount of applied irrigation water for different treatments varied from 2.93m3 to 1.08 m3. The results showed that mango fruit production and quality at fruit growth stage were significantly affected under different irrigation water amounts. Variation in soil water content not only had effects on fruit size, but also on fruit yield. The highest fruit yield and irrigation water use efficiency were obtained from the T4 treatment. Irrigation water amount also affected fruit quality parameters like fruit total soluble solids, soluble sugar, starch, titratable acid and vitamin C content. Comprehensive evaluation of the effect of indexs of correlation on irrigation treatment by subordinate function showed that when the soil moisture content were controlled at about 65–70% of the field water moisture capacity, water demand in the growth and development of mango could be ensured, and maximum production efficiency of irrigation and the best quality of fruit could be achieved. In conclusion, treatment T4 was the optimum irrigation schedule for growing mango, thus achieving efficient production of mango in consideration of the compromise among mango yield, fruit quality and water use efficiency. PMID:28384647

FISHER'S GEOMETRIC MODEL WITH A MOVING OPTIMUM

PubMed Central

Matuszewski, Sebastian; Hermisson, Joachim; Kopp, Michael

2014-01-01

Fisher's geometric model has been widely used to study the effects of pleiotropy and organismic complexity on phenotypic adaptation. Here, we study a version of Fisher's model in which a population adapts to a gradually moving optimum. Key parameters are the rate of environmental change, the dimensionality of phenotype space, and the patterns of mutational and selectional correlations. We focus on the distribution of adaptive substitutions, that is, the multivariate distribution of the phenotypic effects of fixed beneficial mutations. Our main results are based on an “adaptive-walk approximation,” which is checked against individual-based simulations. We find that (1) the distribution of adaptive substitutions is strongly affected by the ecological dynamics and largely depends on a single composite parameter γ, which scales the rate of environmental change by the “adaptive potential” of the population; (2) the distribution of adaptive substitution reflects the shape of the fitness landscape if the environment changes slowly, whereas it mirrors the distribution of new mutations if the environment changes fast; (3) in contrast to classical models of adaptation assuming a constant optimum, with a moving optimum, more complex organisms evolve via larger adaptive steps. PMID:24898080

Optimum deposition conditions of ultrasmooth silver nanolayers

PubMed Central

2014-01-01

Reduction of surface plasmon-polariton losses due to their scattering on metal surface roughness still remains a challenge in the fabrication of plasmonic devices for nanooptics. To achieve smooth silver films, we study the dependence of surface roughness on the evaporation temperature in a physical vapor deposition process. At the deposition temperature range 90 to 500 K, the mismatch of thermal expansion coefficients of Ag, Ge wetting layer, and sapphire substrate does not deteriorate the metal surface. To avoid ice crystal formation on substrates, the working temperature of the whole physical vapor deposition process should exceed that of the sublimation at the evaporation pressure range. At optimum room temperature, the root-mean-square (RMS) surface roughness was successfully reduced to 0.2 nm for a 10-nm Ag layer on sapphire substrate with a 1-nm germanium wetting interlayer. Silver layers of 10- and 30-nm thickness were examined using an atomic force microscope (AFM), X-ray reflectometry (XRR), and two-dimensional X-ray diffraction (XRD2). PACS 63.22.Np Layered systems; 68. Surfaces and interfaces; thin films and nanosystems (structure and nonelectronic properties); 81.07.-b Nanoscale materials and structures: fabrication and characterization PMID:24685115

The ELLIPSO (tm) system: Elliptical low orbits for mobile communications and other optimum system elements

NASA Technical Reports Server (NTRS)

Castiel, David

1991-01-01

On 5 Nov. 1990, Ellipsat filed with the FCC the first application to provide voice communication services via low earth orbiting (LEO) satellites. The proposed system, ELLIPSO, aims at achieving end-user costs comparable to those in the cellular industry. On 3 Jun. 1991 Ellipsat filed for the second complement of its system. Ellipsat was also the first company to propose combined position determination and mobile voice services via low-earth orbiting satellites. Ellipsat is still the only proponent of elliptical orbits for any commercial system in the United States. ELLIPSO uses a spectrum efficient combination of FDMA and CDMA techniques. Ellipsat's strategy is to tailor required capacity to user demand, reduce initial system costs and investment risks, and allow the provision of services at affordable end-user prices. ELLIPSO offers optimum features in all the components of its system, elliptical orbits, small satellites, integrated protocol and signalling system, integrated end-user electronics, novel marketing approach based on the cooperation with the tenets of mobile communications, end-user costs that are affordable, and a low risk approach as deployment is tailored to the growth of its customer base. The efficient design of the ELLIPSO constellation and system allows estimated end-user costs in the $.50 per minute range, five to six times less than any other system of comparable capability.

Digital Parallel Processor Array for Optimum Path Planning

NASA Technical Reports Server (NTRS)

Kremeny, Sabrina E. (Inventor); Fossum, Eric R. (Inventor); Nixon, Robert H. (Inventor)

1996-01-01

The invention computes the optimum path across a terrain or topology represented by an array of parallel processor cells interconnected between neighboring cells by links extending along different directions to the neighboring cells. Such an array is preferably implemented as a high-speed integrated circuit. The computation of the optimum path is accomplished by, in each cell, receiving stimulus signals from neighboring cells along corresponding directions, determining and storing the identity of a direction along which the first stimulus signal is received, broadcasting a subsequent stimulus signal to the neighboring cells after a predetermined delay time, whereby stimulus signals propagate throughout the array from a starting one of the cells. After propagation of the stimulus signal throughout the array, a master processor traces back from a selected destination cell to the starting cell along an optimum path of the cells in accordance with the identity of the directions stored in each of the cells.

The optimum decision rules for the oddity task.

PubMed

Versfeld, N J; Dai, H; Green, D M

1996-01-01

This paper presents the optimum decision rule for an m-interval oddity task in which m-1 intervals contain the same signal and one is different or odd. The optimum decision rule depends on the degree of correlation among observations. The present approach unifies the different strategies that occur with "roved" or "fixed" experiments (Macmillan & Creelman, 1991, p. 147). It is shown that the commonly used decision rule for an m-interval oddity task corresponds to the special case of highly correlated observations. However, as is also true for the same-different paradigm, there exists a different optimum decision rule when the observations are independent. The relation between the probability of a correct response and d' is derived for the three-interval oddity task. Tables are presented of this relation for the three-, four-, and five-interval oddity task. Finally, an experimental method is proposed that allows one to determine the decision rule used by the observer in an oddity experiment.

Psychosocial Keys to African American Achievement? Examining the Relationship between Achievement and Psychosocial Variables in High Achieving African Americans

ERIC Educational Resources Information Center

Dixson, Dante D.; Roberson, Cyrell C. B.; Worrell, Frank C.

2017-01-01

Grit, growth mindset, ethnic identity, and other group orientation are four psychosocial variables that have been associated with academic achievement in adolescent populations. In a sample of 105 high achieving African American high school students (cumulative grade point average [GPA] > 3.0), we examined whether these four psychosocial…

Growth/no growth boundary of Clostridium perfringens from spores in cooked meat: A logistic analysis.

PubMed

Huang, Lihan; Li, Changcheng; Hwang, Cheng-An

2018-02-02

Clostridium perfringens is a major foodborne health hazard that can cause acute gastroenteritis in consumers, and is often associated with cooked meat and poultry products. Improper cooling after cooking may allow this pathogen to grow in a product, producing an enterotoxin that causes food poisoning. This study was conducted to evaluate the effect of common ingredients, including sodium tripolyphosphate (STPP), sodium lactate (NaL), and sodium chloride (NaCl), on the germination and outgrowth of C. perfringens spores in meat products. The growth/no growth test was conducted in Shahidi Ferguson Perfringens agar mixed with STPP (0-2500ppm), NaL (0-4%), and NaCl (0-4%) in microplates. Turbidity measurements at 600nm were compared before and after anaerobic incubation at 46°C to evaluate growth and no growth conditions. The dichotomous responses were analyzed by logistic regression to develop a model for estimating the growth probability of C. perfringens. The probability model was used to define the threshold of growth (probability >0.1 or 0.2) of C. perfringens and validated using inoculated ground beef under optimum temperature. Inoculated ground beef was mixed with different combinations of STPP, NaL, and NaCl to observe growth or no growth of C. perfringens, and the probability was calculated from the formulation. If the threshold of growth was set to 0.2, the accuracy of the growth and no growth predictions was 95.7%, with 4.3% over-prediction of growth events (fail-safe). The results from this study suggested that proper combinations of STPP, NaL, and NaCl could be used to control the growth of C. perfringens in cooked beef under the optimum temperature. The results may also suggest that proper combinations of STPP, NaL, and NaCl in cooked meat and poultry products could be used to prevent the growth of C. perfringens during cooling. Published by Elsevier B.V.

Intrinsic kinetic parameters of Thermococcus onnurineus NA1 strains and prediction of optimum carbon monoxide level for ideal bioreactor operation.

PubMed

Jeong, Yeseul; Jang, Nulee; Yasin, Muhammad; Park, Shinyoung; Chang, In Seop

2016-02-01

This study determines and compares the intrinsic kinetic parameters (Ks and Ki) of selected Thermococcus onnurineus NA1 strains (wild-type (WT), and mutants MC01, MC02, and WTC156T) using the substrate inhibition model. Ks and Ki values were used to find the optimum dissolved CO (CL) conditions inside the reactor. The results showed that in terms of the maximum specific CO consumption rates (qCO(max)) of WT, MC01, MC02, and WTC156T the optimum activities can be achieved by maintaining the CL levels at 0.56mM, 0.52mM, 0.58mM, and 0.75mM, respectively. The qCO(max) value of WTC156T at 0.75mM was found to be 1.5-fold higher than for the WT strain, confirming its superiority. Kinetic modeling was then used to predict the conditions required to maintain the optimum CL levels and high cell concentrations in the reactor, based on the kinetic parameters of the WTC156T strain. Copyright © 2015 Elsevier Ltd. All rights reserved.

A tradeoff study of determine the optimum approach to a wash/rinse capability to support future space flight

NASA Technical Reports Server (NTRS)

Wilson, D. A.

1976-01-01

Specific requirements for a wash/rinse capability to support Spacelab biological experimentation and to identify various concepts for achieving this capability were determined. This included the examination of current state-of-the-art and emerging technology designs that would meet the wash/rinse requirements. Once several concepts were identified, including the disposable utensils, tools and gloves or other possible alternatives, a tradeoff analysis involving system cost, weight, volume utilization, functional performance, maintainability, reliability, power utilization, safety, complexity, etc., was performed so as to determine an optimum approach for achieving a wash/rinse capability to support future space flights. Missions of varying crew size and durations were considered.

The Impact of Worksite Clinics on Teacher Healthcare Utilization and Cost, Self-reported Health Status, and Student Academic Achievement growth in a Public School District.

PubMed

Engberg, John B; Harris-Shapiro, Jon; Hines, David; McCarver, Patti; Liu, Harry H

2018-05-29

To examine the impact of worksite clinics on healthcare utilization and cost, self-reported health status, and student achievement growth in a public school district. We used insurance claims, health risk assessment, and student achievement growth data for active teachers during 2007-2015. A difference-in-differences approach was applied to measure the impact of worksite clinics. Compared to using a community-based clinic as the usual source of primary care, using a worksite clinic was associated with significantly lower inpatient admissions (53 vs. 31 per 1,000 teacher years), annual healthcare cost ($5,043 vs. $4,298 in 2016 US dollars, a difference of $62 per teacher per month), and annual absent work hours (63 vs. 61). No significant differences were detected in self-reported health status or student achievement growth. Worksite clinics reduce teacher healthcare cost and absenteeism.

Analysis of the Optimum Receiver Design Problem Using Interactive Computer Graphics.

DTIC Science & Technology

1981-12-01

7 _AD A115 498A l AR FORCE INST OF TECH WR16HT-PATTERSON AF8 OH SCHOO--ETC F/6 9/2 ANALYSIS OF THE OPTIMUM RECEIVER DESIGN PROBLEM USING INTERACTI...ANALYSIS OF THE OPTIMUM RECEIVER DESIGN PROBLEM USING INTERACTIVE COMPUTER GRAPHICS THESIS AFIT/GE/EE/81D-39 Michael R. Mazzuechi Cpt USA Approved for...public release; distribution unlimited AFIT/GE/EE/SlD-39 ANALYSIS OF THE OPTIMUM RECEIVER DESIGN PROBLEM USING INTERACTIVE COMPUTER GRAPHICS THESIS

Thermal optimum design for tracking primary mirror of Space Telescope

NASA Astrophysics Data System (ADS)

Pan, Hai-jun; Ruan, Ping; Li, Fu; Wang, Hong-Wei

2011-08-01

In the conventional method, the structural parameters of primary mirror are usually optimized just by the requirement of mechanical performance. Because the influences of structural parameters on thermal stability are not taken fully into account in this simple method, the lightweight optimum design of primary mirror usually brings the bad thermal stability, especially in the complex environment. In order to obtain better thermal stability, a new method about structure-thermal optimum design of tracking primary mirror is discussed. During the optimum process, both the lightweight ratio and thermal stability will be taken into account. The structure-thermal optimum is introduced into the analysis process and commenced after lightweight design as the secondary optimum. Using the engineering analysis of software ANSYS, a parameter finite element analysis (FEA) model of mirror is built. On the premise of appropriate lightweight ratio, the RMS of structure-thermal deformation of mirror surface and lightweight ratio are assigned to be state variables, and the maximal RMS of temperature gradient load to be object variable. The results show that certain structural parameters of tracking primary mirror have different influences on mechanical performance and thermal stability, even they are opposite. By structure-thermal optimizing, the optimized mirror model discussed in this paper has better thermal stability than the old one under the same thermal loads, which can drastically reduce difficulty in thermal control.

Optimum gradient of mountain paths.

PubMed

Minetti, A E

1995-11-01

By combining the experiment results of R. Margaria (Atti Accad. Naz. Lincei Memorie 7: 299-368, 1938), regarding the metabolic cost of gradient locomotion, together with recent insights on gait biomechanics, a prediction about the most economical gradient of mountain paths (approximately 25%) is obtained and interpreted. The pendulum-like mechanism of walking produces a waste of mechanical work against gravity within the gradient range of up to 15% (the overall efficiency is dominated by the low transmission efficiency), whereas for steeper values only the muscular efficiency is responsible for the (slight) metabolic change (per meter of vertical displacement) with respect to gradient. The speeds at the optimum gradient turned out to be approximately 0.65 m/s (+0.16 m/s vertical) and 1.50 m/s (-0.36 m/s vertical), for uphill and downhill walking, respectively, and the ascensional energy expenditure was 0.4 and 2.0 ml O2.kg body mass-1.vertical m-1 climbed or descended. When the metabolic power becomes a burden, as in high-altitude mountaineering, the optimum gradient should be reduced. A sample of real mountain path gradients, experimentally measured, mimics the obtained predictions.

A Study of Optimum Population Levels—A Progress Report*

PubMed Central

Singer, S. Fred

1972-01-01

The purpose of this study is to explore different approaches and to develop a methodology that will allow a calculation of “optimum levels of population.” The discussion is specialized to the United States, but the methodology should be broad enough to handle other countries, including less-developed countries. The study is based on economics, but with major inputs from the areas of technology, natural resources management, environmental effects, and demography. The general approach will be to develop an index for quality of life (IQL or Q-index) and to maximize this index as a function of level and distribution of population. The technique consists of a reshuffling of national income accounts so as to be able to go from the Gross National Product (GNP) to the index for quality of life, plus a careful discussion of what is and what is not to be included. The initial part of the study consists of a projection of the index for quality of life as population level increases and as population distribution changes, under the assumption of various technologies, particularly as these relate to the consumption of minerals, energy, and other natural resources. One would expect that as economic growth continues, an increasing fraction of expenditures would be for the diseconomics produced by population growth and economic growth. This study should be useful by providing a rational base for governmental policies regarding population, both in the United States and abroad. Another application of the study is to technology assessment, by measurement of the impact on economic well-being through the introduction of new technologies. Therefore, one can gauge the necessary and desirable investments in certain new technologies. In general, mathematical models resulting from this study can become useful diagnostic tools to analyze the consequences of various public and private policy decisions. PMID:4509346

Nontargeted LC-MS Metabolomics Approach for Metabolic Profiling of Plasma and Urine from Pigs Fed Branched Chain Amino Acids for Maximum Growth Performance.

PubMed

Soumeh, Elham A; Hedemann, Mette S; Poulsen, Hanne D; Corrent, Etienne; van Milgen, Jacob; Nørgaard, Jan V

2016-12-02

The metabolic response in plasma and urine of pigs when feeding an optimum level of branched chain amino acids (BCAAs) for best growth performance is unknown. The objective of the current study was to identify the metabolic phenotype associated with the BCAAs intake level that could be linked to the animal growth performance. Three dose-response studies were carried out to collect blood and urine samples from pigs fed increasing levels of Ile, Val, or Leu followed by a nontargeted LC-MS approach to characterize the metabolic profile of biofluids when dietary BCAAs are optimum for animal growth. Results showed that concentrations of plasma hypoxanthine and tyrosine (Tyr) were higher while concentrations of glycocholic acid, tauroursodeoxycholic acid, and taurocholic acid were lower when the dietary Ile was optimum. Plasma 3-methyl-2-oxovaleric acid and creatine were lower when dietary Leu was optimum. The optimum dietary Leu resulted in increased urinary excretion of ascorbic acid and choline and relatively decreased excretion of 2-aminoadipic acid, acetyl-dl-valine, Ile, 2-methylbutyrylglycine, and Tyr. In conclusion, plasma glycocholic acid and taurocholic acid were discriminating metabolites to the optimum dietary Ile. The optimum dietary Leu was associated with reduced plasma creatine and urinary 2-aminoadipic acid and elevated urinary excretion of ascorbic acid and choline. The optimum dietary Val had a less pronounced metabolic response reflected in plasma or urine than other BCAA.

How Do Teacher Evaluation Ratings on Kentucky's Professional Growth and Effectiveness System Relate to Student Achievement?

ERIC Educational Resources Information Center

Masters, Jim

2017-01-01

The purpose of this study was to determine if a teacher's Professional Growth and Effectiveness System (PGES) rating is an effective indicator for student achievement. Participants in the study were 9th through 12th grade English 10, Biology, U.S. History and Algebra 2 teachers and students enrolled in their courses. The teacher participants'…

MT's algorithm: A new algorithm to search for the optimum set of modulation indices for simultaneous range, command, and telemetry

NASA Technical Reports Server (NTRS)

Nguyen, Tien Manh

1989-01-01

MT's algorithm was developed as an aid in the design of space telecommunications systems when utilized with simultaneous range/command/telemetry operations. This algorithm provides selection of modulation indices for: (1) suppression of undesired signals to achieve desired link performance margins and/or to allow for a specified performance degradation in the data channel (command/telemetry) due to the presence of undesired signals (interferers); and (2) optimum power division between the carrier, the range, and the data channel. A software program using this algorithm was developed for use with MathCAD software. This software program, called the MT program, provides the computation of optimum modulation indices for all possible cases that are recommended by the Consultative Committee on Space Data System (CCSDS) (with emphasis on the squarewave, NASA/JPL ranging system).

Auxin-induced growth of Avena coleoptiles involves two mechanisms with different pH optima

NASA Technical Reports Server (NTRS)

Cleland, R. E.

1992-01-01

Although rapid auxin-induced growth of coleoptile sections can persist for at least 18 hours, acid-induced growth lasts for a much shorter period of time. Three theories have been proposed to explain this difference in persistence. To distinguish between these theories, the pH dependence for auxin-induced growth of oat (Avena sativa L.) coleoptiles has been determined early and late in the elongation process. Coleoptile sections from which the outer epidermis was removed to facilitate buffer entry were incubated, with or without 10 micromolar indoleacetic acid, in 20 millimolar buffers at pH 4.5 to 7.0 to maintain a fixed wall pH. During the first 1 to 2 hours after addition of auxin, elongation occurs by acid-induced extension (i.e. the pH optimum is <5 and the elongation varies inversely with the solution pH). Auxin causes no additional elongation because the buffers prevent further changes in wall pH. After 60 to 90 minutes, a second mechanism of auxin-induced growth, whose pH optimum is 5.5 to 6.0, predominates. It is proposed that rapid growth responses to changes in auxin concentration are mediated by auxin-induced changes in wall pH, whereas the prolonged, steady-state growth rate is controlled by a second, auxin-mediated process whose pH optimum is less acidic.

Optimum measurement for unambiguously discriminating two mixed states: General considerations and special cases

NASA Astrophysics Data System (ADS)

Herzog, Ulrike; Bergou, János A.

2006-04-01

Based on our previous publication [U. Herzog and J. A. Bergou, Phys. Rev. A 71, 050301(R)(2005)] we investigate the optimum measurement for the unambiguous discrimination of two mixed quantum states that occur with given prior probabilities. Unambiguous discrimination of nonorthogonal states is possible in a probabilistic way, at the expense of a nonzero probability of inconclusive results, where the measurement fails. Along with a discussion of the general problem, we give an example illustrating our method of solution. We also provide general inequalities for the minimum achievable failure probability and discuss in more detail the necessary conditions that must be fulfilled when its absolute lower bound, proportional to the fidelity of the states, can be reached.

Predicting optimum crop designs using crop models and seasonal climate forecasts.

PubMed

Rodriguez, D; de Voil, P; Hudson, D; Brown, J N; Hayman, P; Marrou, H; Meinke, H

2018-02-02

Expected increases in food demand and the need to limit the incorporation of new lands into agriculture to curtail emissions, highlight the urgency to bridge productivity gaps, increase farmers profits and manage risks in dryland cropping. A way to bridge those gaps is to identify optimum combination of genetics (G), and agronomic managements (M) i.e. crop designs (GxM), for the prevailing and expected growing environment (E). Our understanding of crop stress physiology indicates that in hindsight, those optimum crop designs should be known, while the main problem is to predict relevant attributes of the E, at the time of sowing, so that optimum GxM combinations could be informed. Here we test our capacity to inform that "hindsight", by linking a tested crop model (APSIM) with a skillful seasonal climate forecasting system, to answer "What is the value of the skill in seasonal climate forecasting, to inform crop designs?" Results showed that the GCM POAMA-2 was reliable and skillful, and that when linked with APSIM, optimum crop designs could be informed. We conclude that reliable and skillful GCMs that are easily interfaced with crop simulation models, can be used to inform optimum crop designs, increase farmers profits and reduce risks.

Expert System Control of Plant Growth in an Enclosed Space

NASA Technical Reports Server (NTRS)

May, George; Lanoue, Mark; Bathel, Matthew; Ryan, Robert E.

2008-01-01

The Expert System is an enclosed, controlled environment for growing plants, which incorporates a computerized, knowledge-based software program that is designed to capture the knowledge, experience, and problem-solving skills of one or more human experts in a particular discipline. The Expert System is trained to analyze crop/plant status, to monitor the condition of the plants and the environment, and to adjust operational parameters to optimize the plant-growth process. This system is intended to provide a way to remotely control plant growth with little or no human intervention. More specifically, the term control implies an autonomous method for detecting plant states such as health (biomass) or stress and then for recommending and implementing cultivation and/or remediation to optimize plant growth and to minimize consumption of energy and nutrients. Because of difficulties associated with delivering energy and nutrients remotely, a key feature of this Expert System is its ability to minimize this effort and to achieve optimum growth while taking into account the diverse range of environmental considerations that exist in an enclosed environment. The plant-growth environment for the Expert System could be made from a variety of structures, including a greenhouse, an underground cavern, or another enclosed chamber. Imaging equipment positioned within or around the chamber provides spatially distributed crop/plant-growth information. Sensors mounted in the chamber provide data and information pertaining to environmental conditions that could affect plant development. Lamps in the growth environment structure supply illumination, and other additional equipment in the chamber supplies essential nutrients and chemicals.

Optimum Water Chemistry in radiation field buildup control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Chien, C.

1995-03-01

Nuclear utilities continue to face the challenGE of reducing exposure of plant maintenance personnel. GE Nuclear Energy has developed the concept of Optimum Water Chemistry (OWC) to reduce the radiation field buildup and minimize the radioactive waste production. It is believed that reduction of radioactive sources and improvement of the water chemistry quality should significantly reduce both the radiation exposure and radwaste production. The most important source of radioactivity is cobalt and replacement of cobalt containing alloy in the core region as well as in the entire primary system is considered the first priority to achieve the goal of lowmore » exposure and minimized waste production. A plant specific computerized cobalt transport model has been developed to evaluate various options in a BWR system under specific conditions. Reduction of iron input and maintaining low ionic impurities in the coolant have been identified as two major tasks for operators. Addition of depleted zinc is a proven technique to reduce Co-60 in reactor water and on out-of-core piping surfaces. The effect of HWC on Co-60 transport in the primary system will also be discussed.« less

Measuring Opportunity to Learn and Achievement Growth: Key Research Issues with Implications for the Effective Education of All Students

ERIC Educational Resources Information Center

Elliott, Stephen N.

2015-01-01

The related constructs of opportunity to learn (OTL) and achievement growth are fundamental aspects of the current large-scale assessment and accountability system in operation in the United States. For purposes of this article, OTL is defined as the degree to which a teacher dedicates instructional time and content coverage to the intended…

A comprehensive study of sampling-based optimum signal detection in concentration-encoded molecular communication.

PubMed

Mahfuz, Mohammad U; Makrakis, Dimitrios; Mouftah, Hussein T

2014-09-01

In this paper, a comprehensive analysis of the sampling-based optimum signal detection in ideal (i.e., free) diffusion-based concentration-encoded molecular communication (CEMC) system has been presented. A generalized amplitude-shift keying (ASK)-based CEMC system has been considered in diffusion-based noise and intersymbol interference (ISI) conditions. Information is encoded by modulating the amplitude of the transmission rate of information molecules at the TN. The critical issues involved in the sampling-based receiver thus developed are addressed in detail, and its performance in terms of the number of samples per symbol, communication range, and transmission data rate is evaluated. ISI produced by the residual molecules deteriorates the performance of the CEMC system significantly, which further deteriorates when the communication range and/or the transmission data rate increase(s). In addition, the performance of the optimum receiver depends on the receiver's ability to compute the ISI accurately, thus providing a trade-off between receiver complexity and achievable bit error rate (BER). Exact and approximate detection performances have been derived. Finally, it is found that the sampling-based signal detection scheme thus developed can be applied to both binary and multilevel (M-ary) ASK-based CEMC systems, although M-ary systems suffer more from higher BER.

Optimum strata boundaries and sample sizes in health surveys using auxiliary variables

PubMed Central

2018-01-01

Using convenient stratification criteria such as geographical regions or other natural conditions like age, gender, etc., is not beneficial in order to maximize the precision of the estimates of variables of interest. Thus, one has to look for an efficient stratification design to divide the whole population into homogeneous strata that achieves higher precision in the estimation. In this paper, a procedure for determining Optimum Stratum Boundaries (OSB) and Optimum Sample Sizes (OSS) for each stratum of a variable of interest in health surveys is developed. The determination of OSB and OSS based on the study variable is not feasible in practice since the study variable is not available prior to the survey. Since many variables in health surveys are generally skewed, the proposed technique considers the readily-available auxiliary variables to determine the OSB and OSS. This stratification problem is formulated into a Mathematical Programming Problem (MPP) that seeks minimization of the variance of the estimated population parameter under Neyman allocation. It is then solved for the OSB by using a dynamic programming (DP) technique. A numerical example with a real data set of a population, aiming to estimate the Haemoglobin content in women in a national Iron Deficiency Anaemia survey, is presented to illustrate the procedure developed in this paper. Upon comparisons with other methods available in literature, results reveal that the proposed approach yields a substantial gain in efficiency over the other methods. A simulation study also reveals similar results. PMID:29621265

Optimum strata boundaries and sample sizes in health surveys using auxiliary variables.

PubMed

Reddy, Karuna Garan; Khan, Mohammad G M; Khan, Sabiha

2018-01-01

Using convenient stratification criteria such as geographical regions or other natural conditions like age, gender, etc., is not beneficial in order to maximize the precision of the estimates of variables of interest. Thus, one has to look for an efficient stratification design to divide the whole population into homogeneous strata that achieves higher precision in the estimation. In this paper, a procedure for determining Optimum Stratum Boundaries (OSB) and Optimum Sample Sizes (OSS) for each stratum of a variable of interest in health surveys is developed. The determination of OSB and OSS based on the study variable is not feasible in practice since the study variable is not available prior to the survey. Since many variables in health surveys are generally skewed, the proposed technique considers the readily-available auxiliary variables to determine the OSB and OSS. This stratification problem is formulated into a Mathematical Programming Problem (MPP) that seeks minimization of the variance of the estimated population parameter under Neyman allocation. It is then solved for the OSB by using a dynamic programming (DP) technique. A numerical example with a real data set of a population, aiming to estimate the Haemoglobin content in women in a national Iron Deficiency Anaemia survey, is presented to illustrate the procedure developed in this paper. Upon comparisons with other methods available in literature, results reveal that the proposed approach yields a substantial gain in efficiency over the other methods. A simulation study also reveals similar results.

The Growth of Berlinite (AlPO4) Single Crystals.

DTIC Science & Technology

1980-03-01

Solubility of AlPO 4 18 6. Solubility Data of Jahn and Kordes on AlPO4 19 7. AlPO 4 Seed Crystal 23 8. Tem-Pres Hydrothermal Research Unit 25 9...Since the vapor pressure of water rises rapidly with temperature, a closed hydrothermal system was used. In a seeded hydrothermal growth process, the...to investigate the hydrothermal growth of Berlinite (AlPO4 ) to determine the optimum growth conditions for large high quality crystals. Over thirty

New constraints in absorptive capacity and the optimum rate of petroleum output

DOE Office of Scientific and Technical Information (OSTI.GOV)

El Mallakh, R

1980-01-01

Economic policy in four oil-producing countries is analyzed within a framework that combines a qualitative assessment of the policy-making process with an empirical formulation based on historical and current trends in these countries. The concept of absorptive capacity is used to analyze the optimum rates of petroleum production in Iran, Iraq, Saudi Arabia, and Kuwait. A control solution with an econometric model is developed which is then modified for alternative development strategies based on analysis of factors influencing production decisions. The study shows the consistencies and inconsistencies between the goals of economic growth, oil production, and exports, and the constraintsmore » on economic development. Simulation experiments incorporated a number of the constraints on absorptive capacity. Impact of other constraints such as income distribution and political stability is considered qualitatively. (DLC)« less

Including climate variability in determination of the optimum rate of N fertilizer application using a crop model: A case study for rainfed corn in eastern Canada

NASA Astrophysics Data System (ADS)

Mesbah, M.; Pattey, E.; Jégo, G.; Geng, X.; Tremblay, N.; Didier, A.

2017-12-01

Identifying optimum nitrogen (N) application rate is essential for increasing agricultural production while limiting potential environmental contaminations caused by release of reactive N, especially for high demand N crops such as corn. The central question of N management is then how the optimum N rate is affected by climate variability for given soil. The experimental determination of optimum N rates involve the analyses of variance on the mean value of crop yield response to various N application rates used by factorial plot based experiments for a few years in several regions. This traditional approach has limitations to capture 1) the non-linear response of yield to N application rates due to large incremental N rates (often more than 40 kg N ha-1) and 2) the ecophysiological response of the crop to climate variability because of limited numbers of growing seasons considered. Modeling on the other hand, does not have such limitations and hence we use a crop model and propose a model-based methodology called Finding NEMO (N Ecophysiologically Modelled Optimum) to identify the optimum N rates for variable agro-climatic conditions and given soil properties. The performance of the methodology is illustrated using the STICS crop model adapted for rainfed corn in the Mixedwood Plains ecozone of eastern Canada (42.3oN 83oW-46.8oN 71oW) where more than 90% of Canadian corn is produced. The simulations were performed using small increment of preplant N application rate (10 kg N ha -1), long time series of daily climatic data (48 to 61 years) for 5 regions along the ecozone, and three contrasting soils per region. The results show that N recommendations should be region and soil specific. Soils with lower available water capacity required more N compared to soil with higher available water capacity. When N rates were at their ecophysiologically optimum level, 10 to 17 kg increase in dry yield could be achieved by adding 1 kg N. Expected yield also affected the optimum

Optimum structure of Whipple shield against hypervelocity impact

NASA Astrophysics Data System (ADS)

Lee, M.

2014-05-01

Hypervelocity impact of a spherical aluminum projectile onto two spaced aluminum plates (Whipple shield) was simulated to estimate an optimum structure. The Smooth Particle Hydrodynamics (SPH) code which has a unique migration scheme from a rectangular coordinate to an axisymmetic coordinate was used. The ratio of the front plate thickness to sphere diameter varied from 0.06 to 0.48. The impact velocities considered here were 6.7 km/s. This is the procedure we explored. To guarantee the early stage simulation, the shapes of debris clouds were first compared with the previous experimental pictures, indicating a good agreement. Next, the debris cloud expansion angle was predicted and it shows a maximum value of 23 degree for thickness ratio of front bumper to sphere diameter of 0.23. A critical sphere diameter causing failure of rear wall was also examined while keeping the total thickness of two plates constant. There exists an optimum thickness ratio of front bumper to rear wall, which is identified as a function of the size combination of the impacting body, front and rear plates. The debris cloud expansion-correlated-optimum thickness ratio study provides a good insight on the hypervelocity impact onto spaced target system.

An eco-efficient and economical optimum evaluation technique for the forest road networks: the case of the mountainous forest of Metsovo, Greece.

PubMed

Tampekis, Stergios; Samara, Fani; Sakellariou, Stavros; Sfougaris, Athanassios; Christopoulou, Olga

2018-02-12

The sustainable forest management can be achieved only through environmentally sound and economically efficient and feasible forest road networks and transportation systems that can potentially improve the multi-functional use of forest resources. However, road network planning and construction suggest long-term finance that require a capital investment (cash outflow), which would be equal to the value of the total revenue flow (cash inflow) over the whole lifecycle project. This paper emphasizes in an eco-efficient and economical optimum evaluation method for the forest road networks in the mountainous forest of Metsovo, Greece. More specifically, with the use of this technique, we evaluated the forest roads' (a) total construction costs, (b) annual maintenance cost, and (c) log skidding cost. In addition, we estimated the total economic value of forest goods and services that are lost from the forest roads' construction. Finally, we assessed the optimum eco-efficient and economical forest roads densities based on linear equations that stem from the internal rate of return method (IRR) and have been presented graphically. Data analysis and its presentation are achieved with the contribution of geographic information systems (GIS). The technique which is described in this study can be for the decision makers an attractive and useful implement in order to select the most eco-friendly and economical optimum solution to plan forest road network or to evaluate the existing forest transportation systems. Hence, with the use of this method, we can combine not only the multi-objective utilization of natural resources but also the environmental protection of forest ecosystems.

Optimum design of structures subject to general periodic loads

NASA Technical Reports Server (NTRS)

Reiss, Robert; Qian, B.

1989-01-01

A simplified version of Icerman's problem regarding the design of structures subject to a single harmonic load is discussed. The nature of the restrictive conditions that must be placed on the design space in order to ensure an analytic optimum are discussed in detail. Icerman's problem is then extended to include multiple forcing functions with different driving frequencies. And the conditions that now must be placed upon the design space to ensure an analytic optimum are again discussed. An important finding is that all solutions to the optimality condition (analytic stationary design) are local optima, but the global optimum may well be non-analytic. The more general problem of distributing the fixed mass of a linear elastic structure subject to general periodic loads in order to minimize some measure of the steady state deflection is also considered. This response is explicitly expressed in terms of Green's functional and the abstract operators defining the structure. The optimality criterion is derived by differentiating the response with respect to the design parameters. The theory is applicable to finite element as well as distributed parameter models.

Optimum Damping in a Non-Linear Base Isolation System

NASA Astrophysics Data System (ADS)

Jangid, R. S.

1996-02-01

Optimum isolation damping for minimum acceleration of a base-isolated structure subjected to earthquake ground excitation is investigated. The stochastic model of the El-Centro1940 earthquake, which preserves the non-stationary evolution of amplitude and frequency content of ground motion, is used as an earthquake excitation. The base isolated structure consists of a linear flexible shear type multi-storey building supported on a base isolation system. The resilient-friction base isolator (R-FBI) is considered as an isolation system. The non-stationary stochastic response of the system is obtained by the time dependent equivalent linearization technique as the force-deformation of the R-FBI system is non-linear. The optimum damping of the R-FBI system is obtained under important parametric variations; i.e., the coefficient of friction of the R-FBI system, the period and damping of the superstructure; the effective period of base isolation. The criterion selected for optimality is the minimization of the top floor root mean square (r.m.s.) acceleration. It is shown that the above parameters have significant effects on optimum isolation damping.

Optimum profit model considering production, quality and sale problem

NASA Astrophysics Data System (ADS)

Chen, Chung-Ho; Lu, Chih-Lun

2011-12-01

Chen and Liu ['Procurement Strategies in the Presence of the Spot Market-an Analytical Framework', Production Planning and Control, 18, 297-309] presented the optimum profit model between the producers and the purchasers for the supply chain system with a pure procurement policy. However, their model with a simple manufacturing cost did not consider the used cost of the customer. In this study, the modified Chen and Liu's model will be addressed for determining the optimum product and process parameters. The authors propose a modified Chen and Liu's model under the two-stage screening procedure. The surrogate variable having a high correlation with the measurable quality characteristic will be directly measured in the first stage. The measurable quality characteristic will be directly measured in the second stage when the product decision cannot be determined in the first stage. The used cost of the customer will be measured by adopting Taguchi's quadratic quality loss function. The optimum purchaser's order quantity, the producer's product price and the process quality level will be jointly determined by maximising the expected profit between them.

Kinetic aspects of chain growth in Fischer-Tropsch synthesis.

PubMed

Filot, Ivo A W; Zijlstra, Bart; Broos, Robin J P; Chen, Wei; Pestman, Robert; Hensen, Emiel J M

2017-04-28

Microkinetics simulations are used to investigate the elementary reaction steps that control chain growth in the Fischer-Tropsch reaction. Chain growth in the FT reaction on stepped Ru surfaces proceeds via coupling of CH and CR surface intermediates. Essential to the growth mechanism are C-H dehydrogenation and C hydrogenation steps, whose kinetic consequences have been examined by formulating two novel kinetic concepts, the degree of chain-growth probability control and the thermodynamic degree of chain-growth probability control. For Ru the CO conversion rate is controlled by the removal of O atoms from the catalytic surface. The temperature of maximum CO conversion rate is higher than the temperature to obtain maximum chain-growth probability. Both maxima are determined by Sabatier behavior, but the steps that control chain-growth probability are different from those that control the overall rate. Below the optimum for obtaining long hydrocarbon chains, the reaction is limited by the high total surface coverage: in the absence of sufficient vacancies the CHCHR → CCHR + H reaction is slowed down. Beyond the optimum in chain-growth probability, CHCR + H → CHCHR and OH + H → H 2 O limit the chain-growth process. The thermodynamic degree of chain-growth probability control emphasizes the critical role of the H and free-site coverage and shows that at high temperature, chain depolymerization contributes to the decreased chain-growth probability. That is to say, during the FT reaction chain growth is much faster than chain depolymerization, which ensures high chain-growth probability. The chain-growth rate is also fast compared to chain-growth termination and the steps that control the overall CO conversion rate, which are O removal steps for Ru.

Simulating bimodal tall fescue growth with a degree-day-based process-oriented plant model

USDA-ARS?s Scientific Manuscript database

Plant growth simulation models have a temperature response function driving development, with a base temperature and an optimum temperature defined. Such growth simulation models often function well when plant development rate shows a continuous change throughout the growing season. This approach ...

Mycotoxin production and predictive modelling kinetics on the growth of Aspergillus flavus and Aspergillus parasiticus isolates in whole black peppercorns (Piper nigrum L).

PubMed

Yogendrarajah, Pratheeba; Vermeulen, An; Jacxsens, Liesbeth; Mavromichali, Evangelia; De Saeger, Sarah; De Meulenaer, Bruno; Devlieghere, Frank

2016-07-02

The growth and mycotoxin production of three Aspergillus flavus isolates and an Aspergillus parasiticus isolate were studied in whole black peppercorns (Piper nigrum L.) using a full factorial design with seven water activity (aw) (0.826-0.984) levels and three temperatures (22, 30 and 37°C). Growth rates and lag phases were estimated using linear regression. Diverse secondary models were assessed for their ability to describe the radial growth rate as a function of individual and combined effect of aw and temperature. Optimum radial growth rate ranged from 0.75±0.04 to 2.65±0.02mm/day for A. flavus and 1.77±0.10 to 2.50±0.10mm/day for A. parasiticus based on the Rosso cardinal estimations. Despite the growth failure of some isolates at marginal conditions, all the studied models showed good performance to predict the growth rates. Validation of the models was performed on independently derived data. The bias factors (0.73-1.03), accuracy factors (0.97-1.36) and root mean square error (0.050-0.278) show that the examined models are conservative predictors of the colony growth rate of both fungal species in black peppers. The Rosso cardinal model can be recommended to describe the individual aw effect while the extended Gibson model was the best model for describing the combined effect of aw and temperature on the growth rate of both fungal species in peppercorns. Temperature optimum ranged from 30 to 33°C, while aw optimum was 0.87-0.92 as estimated by multi-factorial cardinal model for both species. The estimated minimum temperature and aw for A. flavus and A. parasiticus for growth were 11-16°C and 0.73-0.76, respectively, hence, achieving these conditions should be considered during storage to prevent the growth of these mycotoxigenic fungal species in black peppercorns. Following the growth study, production of mycotoxins (aflatoxins B1, B2, G1, G2, sterigmatocystin and O-methyl sterigmatocystin (OMST)) was quantified using LC-MS/MS. Very small

Mechanism-based site-directed mutagenesis to shift the optimum pH of the phenylalanine ammonia-lyase from Rhodotorula glutinis JN-1.

PubMed

Zhu, Longbao; Zhou, Li; Cui, Wenjing; Liu, Zhongmei; Zhou, Zhemin

2014-09-01

Phenylalanine ammonia-lyase ( Rg PAL) from Rhodotorula glutinis JN-1 stereoselectively catalyzes the conversion of the l-phenylalanine into trans -cinnamic acid and ammonia, and was used in chiral resolution of dl-phenylalanine to produce the d-phenylalanine under acidic condition. However, the optimum pH of Rg PAL is 9 and the Rg PAL exhibits low catalytic efficiency at acidic side. Therefore, a mutant Rg PAL with a lower optimum pH is expected. Based on catalytic mechanism and structure analysis, we constructed a mutant Rg PAL-Q137E by site-directed mutagenesis, and found that this mutant had an extended optimum pH 7-9 with activity of 1.8-fold higher than that of the wild type at pH 7. As revealed by Friedel-Crafts-type mechanism of Rg PAL, the improvement of the Rg PAL-Q137E might be due to the negative charge of Glu137 which could stabilize the intermediate transition states through electrostatic interaction. The Rg PAL-Q137E mutant was used to resolve the racemic dl-phenylalanine, and the conversion rate and the ee D value of d-phenylalanine using Rg PAL-Q137E at pH 7 were increased by 29% and 48%, and achieved 93% and 86%, respectively. This work provides an effective strategy to shift the optimum pH which is favorable to further applications of Rg PAL.

The Influence of Low Frequency Mechanical Vibrations on the Growth of Single Crystals

NASA Technical Reports Server (NTRS)

Feigelson, R. S.; Elwell, D.

1985-01-01

The optimum conditions for crystal growth are usually achieved either by suppressing convective fluid flows (e.g., by the use of a low-gravity environment) or by over-riding thermal and solutal convection by the use of a strong stirring action. A novel stirring technique has been developed which involves subjecting a vertical crucible to a circle in a horizontal plane (without rotation). Use of an amplitude of 3 mm at a frequency of approx 6 Hz produced complete mixing of a non-uniform aqueous liquid in a few seconds. The mixing action involved the downward flow of liquid in the outer annulus of the liquid, driven by surface waves. When the downward flowing liquid reaches the bottom of the crucible, it is reflected in a central, upward flowing spiral. This flow pattern should be beneficial for crystal growth by the Bridgman method since it will sweep impurities away from the walls and produce a more convex solid-liquid interface. Initial attempts to apply the new stirring technique to CdTe crystal growth did not show significant improvement in the number of crystals nucleated, but the interface shape appeared to be close to that predicted.

Students' Achievement and Homework Assignment Strategies.

PubMed

Fernández-Alonso, Rubén; Álvarez-Díaz, Marcos; Suárez-Álvarez, Javier; Muñiz, José

2017-01-01

The optimum time students should spend on homework has been widely researched although the results are far from unanimous. The main objective of this research is to analyze how homework assignment strategies in schools affect students' academic performance and the differences in students' time spent on homework. Participants were a representative sample of Spanish adolescents ( N = 26,543) with a mean age of 14.4 (±0.75), 49.7% girls. A test battery was used to measure academic performance in four subjects: Spanish, Mathematics, Science, and Citizenship. A questionnaire allowed the measurement of the indicators used for the description of homework and control variables. Two three-level hierarchical-linear models (student, school, autonomous community) were produced for each subject being evaluated. The relationship between academic results and homework time is negative at the individual level but positive at school level. An increase in the amount of homework a school assigns is associated with an increase in the differences in student time spent on homework. An optimum amount of homework is proposed which schools should assign to maximize gains in achievement for students overall.

Students' Achievement and Homework Assignment Strategies

PubMed Central

Fernández-Alonso, Rubén; Álvarez-Díaz, Marcos; Suárez-Álvarez, Javier; Muñiz, José

2017-01-01

The optimum time students should spend on homework has been widely researched although the results are far from unanimous. The main objective of this research is to analyze how homework assignment strategies in schools affect students' academic performance and the differences in students' time spent on homework. Participants were a representative sample of Spanish adolescents (N = 26,543) with a mean age of 14.4 (±0.75), 49.7% girls. A test battery was used to measure academic performance in four subjects: Spanish, Mathematics, Science, and Citizenship. A questionnaire allowed the measurement of the indicators used for the description of homework and control variables. Two three-level hierarchical-linear models (student, school, autonomous community) were produced for each subject being evaluated. The relationship between academic results and homework time is negative at the individual level but positive at school level. An increase in the amount of homework a school assigns is associated with an increase in the differences in student time spent on homework. An optimum amount of homework is proposed which schools should assign to maximize gains in achievement for students overall. PMID:28326046

Characteristics of OMVPE grown GaAsBi QW lasers and impact of post-growth thermal annealing

NASA Astrophysics Data System (ADS)

Kim, Honghyuk; Guan, Yingxin; Babcock, Susan E.; Kuech, Thomas F.; Mawst, Luke J.

2018-03-01

Laser diodes employing a strain-compensated GaAs1-xBix/GaAs1-yPy single quantum well (SQW) active region were grown by organometallic vapor phase epitaxy (OMVPE). High resolution x-ray diffraction, room temperature photoluminescence, and real-time optical reflectance measurements during the OMVPE growth were used to find the optimum process window for the growth of the active region material. Systematic post-growth in situ thermal anneals of various lengths were carried out in order to investigate the impacts of thermal annealing on the laser device performance characteristics. While the lowest threshold current density was achieved after the thermal annealing for 30 min at 630 °C, a gradual decrease in the external differential quantum efficiency was observed as the annealing time increases. It was observed that the temperature sensitivities of the threshold current density increase while those of lasing wavelength and slope efficiency remain nearly constant with increasing annealing time. Z-contrast scanning transmission electron microscopic) analysis revealed inhomogeneous Bi distribution within the QW active region.

A first course in optimum design of yacht sails

NASA Astrophysics Data System (ADS)

Sugimoto, Takeshi

1993-03-01

The optimum sail geometry is analytically obtained for the case of maximizing the thrust under equality and inequality constraints on the lift and the heeling moment. A single mainsail is assumed to be set close-hauled in uniform wind and upright on the flat sea surface. The governing parameters are the mast height and the gap between the sail foot and the sea surface. The lifting line theory is applied to analyze the aerodynamic forces acting on a sail. The design method consists of the variational principle and a feasibility study. Almost triangular sails are found to be optimum. Their advantages are discussed.

Noachian-Hesperian Transition and a Possible Climatic Optimum: Evidence from Landforms

NASA Technical Reports Server (NTRS)

Moore, J. M.; Howard, A. D.

2004-01-01

A climatic optimum? The often strong contrast between the pristine and degraded Noachian channels and craters might be due to a gradual climatic change superimposed upon an episode of mantling associated with early Hesperian volcanism. On the other hand, one or more episodes of volcanism or large impacts could have induced global warming and produced a relatively short-lived optimum for precipitation and runoff. The rapid cutoff of fluvial activity following the development of the later pristine fluvial features is consistent with this scenario. We discuss the changing style of erosion in the highlands during the Noachian and early Hesperian in a companion abstract to this workshop. Here we review the some of the morphologic evidence for a possible Noachian-Hesperian (N-H) climate optimum.

Human equivalent power: towards an optimum energy level

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hafner, E.

1979-01-01

How much energy would be needed to support the average individual in an efficient technological culture. Present knowledge provides information about minimum dietary power needs; but so far we have not been able to find ways of analyzing other human needs which, in a civilized society, rise far above the power of metabolism. Thus we understand the level at its minimum but not at its optimum. This paper attempts to quantify an optimum power level for civilized society. The author describes a method he uses in seminars to quantify how many servants in units of human equivalent power (HEP) aremore » needed to supply a person in a upper-middle-class lifestyle. Typical seminar participants determine a per-capita power budget of 15 HEPs (perfect servants) would be required. Each human being on earth today is, according to the author, the master of forty slaves; in the U.S., he says, the number is close to 200. He concludes that a highly civilized standard of living may be closely associated with an optimum per capita power budget of 1500 watts; and since the average individual in the U.S. participates in energy turnover at almost ten times the rate he knows intuitively to be reasonable, reformation of American power habits will require reconstruction that shakes the house from top to bottom.« less

Optimum Particle Size for Gold-Catalyzed CO Oxidation

PubMed Central

2018-01-01

The structure sensitivity of gold-catalyzed CO oxidation is presented by analyzing in detail the dependence of CO oxidation rate on particle size. Clusters with less than 14 gold atoms adopt a planar structure, whereas larger ones adopt a three-dimensional structure. The CO and O2 adsorption properties depend strongly on particle structure and size. All of the reaction barriers relevant to CO oxidation display linear scaling relationships with CO and O2 binding strengths as main reactivity descriptors. Planar and three-dimensional gold clusters exhibit different linear scaling relationship due to different surface topologies and different coordination numbers of the surface atoms. On the basis of these linear scaling relationships, first-principles microkinetics simulations were conducted to determine CO oxidation rates and possible rate-determining step of Au particles. Planar Au9 and three-dimensional Au79 clusters present the highest CO oxidation rates for planar and three-dimensional clusters, respectively. The planar Au9 cluster is much more active than the optimum Au79 cluster. A common feature of optimum CO oxidation performance is the intermediate binding strengths of CO and O2, resulting in intermediate coverages of CO, O2, and O. Both these optimum particles present lower performance than maximum Sabatier performance, indicating that there is sufficient room for improvement of gold catalysts for CO oxidation. PMID:29707098

Determine Neuronal Tuning Curves by Exploring Optimum Firing Rate Distribution for Information Efficiency

PubMed Central

Han, Fang; Wang, Zhijie; Fan, Hong

2017-01-01

This paper proposed a new method to determine the neuronal tuning curves for maximum information efficiency by computing the optimum firing rate distribution. Firstly, we proposed a general definition for the information efficiency, which is relevant to mutual information and neuronal energy consumption. The energy consumption is composed of two parts: neuronal basic energy consumption and neuronal spike emission energy consumption. A parameter to model the relative importance of energy consumption is introduced in the definition of the information efficiency. Then, we designed a combination of exponential functions to describe the optimum firing rate distribution based on the analysis of the dependency of the mutual information and the energy consumption on the shape of the functions of the firing rate distributions. Furthermore, we developed a rapid algorithm to search the parameter values of the optimum firing rate distribution function. Finally, we found with the rapid algorithm that a combination of two different exponential functions with two free parameters can describe the optimum firing rate distribution accurately. We also found that if the energy consumption is relatively unimportant (important) compared to the mutual information or the neuronal basic energy consumption is relatively large (small), the curve of the optimum firing rate distribution will be relatively flat (steep), and the corresponding optimum tuning curve exhibits a form of sigmoid if the stimuli distribution is normal. PMID:28270760

Optimum Landscape Allocation of Conservation Practices for Water Quality and Ecosystem Service Valuation

NASA Astrophysics Data System (ADS)

Dalzell, B. J.; Pennington, D.; Nelson, E.; Mulla, D.; Polasky, S.; Taff, S.

2012-12-01

This study links a spatially-explicit biophysical model (SWAT) with an economic model (InVEST) to identify the economically optimum allocation of conservation practices on the landscape. Combining biophysical and economic analysis allows assessment of the benefits and costs of alternative policy choices through consideration of direct costs and benefits as measured by market transactions as well as non-market benefits and costs from changes in environmental conditions that lead to changes in the provision of ecosystem services. When applied to an agricultural watershed located in South-Central Minnesota, this approach showed that: (1) some modest gains (20% improvement, relative to baseline conditions) in water quality can be achieved without diminishing current economic returns, but that (2) more dramatic reductions in sediment and phosphorus required to meet water quality goals (50% reductions in loadings) will require transitioning land from row crops into perennial vegetation. This shift in land cover will result in a reduction in economic returns unless non-market ecosystem services are also valued. Further results showed that traditional best management practices such as conservation tillage and reduced fertilizer application rates are not sufficient to achieve water quality goals by themselves. Finally, if crop prices drop to pre-2007 levels or valuation of ecosystem services increases, then achieving water quality goals can occur with less of an economic impact to the watershed.

Sharing Leadership Responsibilities Results in Achievement Gains

ERIC Educational Resources Information Center

Armistead, Lew

2010-01-01

Collective, not individual, leadership in schools has a greater impact on student achievement; when principals and teachers share leadership responsibilities, student achievement is higher; and schools having high student achievement also display a vision for student achievement and teacher growth. Those are just a few of the insights into school…

Effect of Growth Parameters on SnO2 Nanowires Growth by Electron Beam Evaporation Method

NASA Astrophysics Data System (ADS)

Rakesh Kumar, R.; Manjula, Y.; Narasimha Rao, K.

2018-02-01

Tin oxide (SnO2) nanowires were synthesized via catalyst assisted VLS growth mechanism by the electron beam evaporation method at a growth temperature of 450 °C. The effects of growth parameters such as evaporation rate of Tin, catalyst film thickness, and different types of substrates on the growth of SnO2 nanowires were studied. Nanowires (NWs) growth was completely seized at higher tin evaporation rates due to the inability of the catalyst particle to initiate the NWs growth. Nanowires diameters were able to tune with catalyst film thickness. Nanowires growth was completely absent at higher catalyst film thickness due to agglomeration of the catalyst film. Optimum growth parameters for SnO2 NWs were presented. Nanocomposites such as Zinc oxide - SnO2, Graphene oxide sheets- SnO2 and Graphene nanosheets-SnO2 were able to synthesize at a lower substrate temperature of 450 °C. These nanocompsoites will be useful in enhancing the capacity of Li-ion batteries, the gas sensing response and also useful in increasing the photo catalytic activity.

Optimum poultry litter rates for maximum profit vs. yield in cotton production

USDA-ARS?s Scientific Manuscript database

Cotton lint yield responds well to increasing rates of poultry litter fertilization, but little is known of how optimum rates for yield compare with optimum rates for profit. The objectives of this study were to analyze cotton lint yield response to poultry litter application rates, determine and co...

Partial biochemical characterization of crude extract extracellular chitinase enzyme from Bacillus subtilis B 298

NASA Astrophysics Data System (ADS)

Lestari, P.; Prihatiningsih, N.; Djatmiko, H. A.

2017-02-01

Extraction and characterization of extracellular chitinase from Bacillus subtilis B 298 have been done. Growth curve determination of B. subtilis B 298, production curve determination of crude extract chitinase from B. subtilis B 298, and partial biochemical characterization of crude extract chitinase have been achieved in this study. Optimum growth of B. subtilis B 298 was achieved at logarithmic phase within 9 hours incubation time, so it was used as inoculum for enzyme production. According to production curve of the enzyme, it was known that incubation time which gave the highest chitinase activity of 15 hours with activity of 6.937 U/mL respectively. Effect of various temperatures on chitinase activity showed that optimum activity was achieved at 40°C with an activity of 5.764 U/mL respectively. Meanwhile, the optimum pH for chitinase activity was achieved at pH of 5.0 with an activity of 6.813 U/mL respectively. This enzyme was then classified as metalloenzyme due to the decline of the activity by EDTA addition. All divalent cations tested acted as inhibitors.

Optical dynamic range maximization for humidity sensing by controlling growth of zinc oxide nanorods

NASA Astrophysics Data System (ADS)

Yusof, Haziezol Helmi Mohd; Harun, Sulaiman Wadi; Dimyati, Kaharudin; Bora, Tanujjal; Mohammed, Waleed S.; Dutta, Joydeep

2018-07-01

An experimental study of the dynamic range maximization with Zinc Oxide (ZnO) nanorods coated glass substrates for humidity and vapor sensing is reported. Growth time of the nanorods and the length of the coated segments were controlled to study the differences between a reference environmental condition (normal humidity or dry condition) and water vapor concentrations. In order to achieve long dynamic range of detection with respect to nanorods coverage, several substrates with triangular patterns of ZnO nanostructures were fabricated by selective hydrothermal growth over different durations of time (5 h, 10 h and 15 h). It was found that maximum dynamic range for the humidity sensing occurs for the combination parameters of normalized length (Z) of 0.23 and normalized scattering coefficient (ζ) of 0.3. A reduction in transmittance by 38% at humidity levels of 80% with reference point as 50% humidity was observed. The results could be correlated to a first order approximation model that assumes uniform growth and the optimum operating conditions for humidity sensing device. This study provides an option to correlate ZnO growth conditions for different vapor sensing applications which can set a platform for compact sensors where modulation of light intensity is followed.

Using Performance Data Gathered at Several Stages of Achievement in Predicting Subsequent Performance.

ERIC Educational Resources Information Center

Owen, Steven V.; Feldhusen, John F.

This study compares the effectiveness of three models of multivariate prediction for academic success in identifying the criterion variance of achievement in nursing education. The first model involves the use of an optimum set of predictors and one equation derived from a regression analysis on first semester grade average in predicting the…

Evolution of the optimum bidirectional (+/- biphasic) wave for defibrillation.

PubMed

Geddes, L A; Havel, W

2000-01-01

Introduction of the asymmetric bidirectional (+/- biphasic) current waveform has made it possible to achieve ventricular defibrillation with less energy and current than are needed with a unidirectional (monophasic) waveform. The symmetrical bidirectional (sinusoidal) waveform was used for the first human-heart defibrillation. Subsequent studies employed the underdamped and overdamped sine waves, then the trapezoidal (monophasic) wave. Studies were then undertaken to investigate the benefit of adding a second identical and inverted wave; little success rewarded these efforts until it was discovered that the second inverted wave needed to be much less in amplitude to lower the threshold for defibrillation. However, there is no physiologic theory that explains the mechanism of action of the bidirectional wave, nor does any theory predict the optimum amplitude and time dimensions for the second inverted wave. The authors analyze the research that shows that the threshold defibrillation energy is lowest when the charge in the second, inverted phase is slightly more than a third of that in the first phase. An ion-flux, spatial-K+ summation hypothesis is presented that shows the effect on myocardial cells of adding the second inverted current pulse.

Standardization of doctoral study in agricultural and extension education: is the field of study mature enough for achievement of the optimum degree of order?

PubMed

Briers, G E; Lindner, J R; Shinn, G C; Wingenbach, G W; Baker, M T

2010-01-01

Agricultural and extension education--or some derivative name--is a field of study leading to the doctoral degree in universities around the world. Is there are body of knowledge or a taxonomy of the knowledge--e.g., a knowledge domain--that one should possess with a doctorate in agricultural and extension education? The purpose of this paper was to synthesize the work of researchers who attempted to define the field of study, with a taxonomy comprising the knowledge domains (standards) and knowledge objects--structured interrelated sets of data, knowledge, and wisdom--of the field of study. Doctoral study in agricultural and extension education needs a document that provides for rules and guidelines--rules and guidelines that in turn provide for common and repeated use--all leading to achievement of an optimum degree of order in the context of academic, scholarly, and professional practice in agricultural and extension education. Thus, one would know in broad categories the knowledge, skills, and abilities possessed by one who holds a doctoral degree in agricultural and extension education. That is, there would exist a standard for doctoral degrees in agricultural and extension education. A content analysis of three previous attempts to categorize knowledge in agricultural and extension education served as the primary technique to create a new taxonomy--or to confirm an existing taxonomy--for doctoral study in agricultural and extension education. The following coalesced as nine essential knowledge domains for a doctorate in agricultural and extension education: (1) history, philosophy, ethics, and policy; (2) agricultural/rural development; (3) organizational development and change management; (4) planning, needs assessment, and evaluation; (5) learning theory; (6) curriculum development and instructional design; (7) teaching methods and delivery strategies; (8) research methods and tools; and, (9) scholarship and communications.

Optimum fiber distribution in singlewall corrugated fiberboard

Treesearch

Millard W. Johnson; Thomas J. Urbanik; William E. Denniston

1979-01-01

Determining optimum distribution of fiber through rational design of corrugated fiberboard could result in significant reductions in fiber required to meet end-use conditions, with subsequent reductions in price pressure and extension of the softwood timber supply. A theory of thin plates under large deformations is developed that is both kinematically and physically...

Common Core: Teaching Optimum Topic Exploration (TOTE)

ERIC Educational Resources Information Center

Karge, Belinda Dunnick; Moore, Roxane Kushner

2015-01-01

The Common Core has become a household term and yet many educators do not understand what it means. This article explains the historical perspectives of the Common Core and gives guidance to teachers in application of Teaching Optimum Topic Exploration (TOTE) necessary for full implementation of the Common Core State Standards. An effective…

Growth and yield model for non-timber forest product of kemenyan (Styrax sumatrana J.J. Sm) in Tapanuli, North Sumatra

NASA Astrophysics Data System (ADS)

Aswandi; Kholibrina, C. R.

2018-02-01

Kemenyan is Styrax tree resin, the main of non-timber forest product commodity in Lake Toba catchment area, North Sumatra since hundreds years ago. However, there are lack of information about the growth and yield prediction for this tree species. The objective of study is to construct the growth and yield models for Styrax sumatrana in Tapanuli region, North Sumatra. Measurement data from 20 temporary plots were used to formulate stand diameter and height equations, and to project the incense production. The highest Current Annual Increment (CAI) of diameter occurs in the stand’s age 21 to 25 years (1.00 cm/year). The growth of diameter declines significantly to 0.48 cm/year in age 46 to 50 years, and decrease to 0.26 cm/year at age 50 years up. The intersection of CAI and MAI curves occur in stand age 31 to 35 years. It shows that the optimal growth occurs in this period. The average of incenses production was 318.59 g/tree/year. The optimum incense production was achieved when the diameter growth was maximal and tapping scars accumulation was limited.

Optimum Waveforms for Differential Ion Mobility Spectrometry (FAIMS)

PubMed Central

Shvartsburg, Alexandre A.; Smith, Richard D.

2009-01-01

Differential mobility spectrometry or field asymmetric waveform ion mobility spectrometry (FAIMS) is a new tool for separation and identification of gas-phase ions, particularly in conjunction with mass-spectrometry. In FAIMS, ions are filtered by the difference between mobilities in gases (K) at high and low electric field intensity (E) using asymmetric waveforms. An infinite number of possible waveform profiles make maximizing the performance within engineering constraints a major issue for FAIMS technology refinement. Earlier optimizations assumed the non-constant component of mobility to scale as E2, producing the same result for all ions. Here we show that the optimum profiles are defined by the full series expansion of K(E) that includes terms beyond the 1st that is proportional to E2. For many ion/gas pairs, the first two terms have different signs, and the optimum profiles at sufficiently high E in FAIMS may differ substantially from those previously reported, improving the resolving power by up to 2.2 times. This situation arises for some ions in all FAIMS systems, but becomes more common in recent miniaturized devices that employ higher E. With realistic K(E) dependences, the maximum waveform amplitude is not necessarily optimum and reducing it by up to ∼20 – 30% is beneficial in some cases. The present findings are particularly relevant to targeted analyses where separation depends on the difference between K(E) functions for specific ions. PMID:18585054

Model-supported phototrophic growth studies with Scenedesmus obtusiusculus in a flat-plate photobioreactor.

PubMed

Koller, Anja Pia; Löwe, Hannes; Schmid, Verena; Mundt, Sabine; Weuster-Botz, Dirk

2017-02-01

Light-dependent growth of microalgae can vary remarkably depending on the cultivation system and microalgal strain. Cell size and the pigmentation of each strain, as well as reactor geometry have a great impact on absorption and scattering behavior within a photobioreactor. In this study, the light-dependent, cell-specific growth kinetics of a novel green algae isolate, Scenedesmus obtusiusculus, was studied in a LED-illuminated flat-plate photobioreactor on a lab-scale (1.8 L, 0.09 m 2 ). First, pH-controlled batch processes were performed with S. obtusiusculus at different constant incident photon flux densities. The best performance was achieved by illuminating S. obtusiusculus with 1400 μmol photons m -2  s -1 at the surface of the flat-plate photobioreactor, resulting in the highest biomass concentration (4.95 ± 0.16 g CDW  L -1 within 3.5 d) and the highest specific growth rate (0.22 h -1 ). The experimental data were used to identify the kinetic parameters of different growth models considering light inhibition for S. obtusiusculus. Light attenuation within the flat-plate photobioreactor was considered by varying light transfer models. Based on the identified kinetic growth model of S. obtusiusculus, an optimum growth rate of 0.22 h -1 was estimated at a mean integral photon flux density of 1072 μmol photons m -2  s -1 with the Beer-Lambert law and 1590 μmol photons m -2  s -1 with Schuster's light transfer model in the flat-plate photobioreactor. LED illumination was, thus, increased to keep the identified optimum mean integral photon flux density constant in the batch process assuming Schuster's light transfer model. Compared to the same constant incident photon flux density (1590 μmol photons m -2  s -1 ), biomass concentration was up to 24% higher using the lighting profile until a dry cell mass concentration of 14.4 ± 1.4 g CDW  L -1 was reached. Afterward, the biomass concentration remained constant

Computer programs for generation and evaluation of near-optimum vertical flight profiles

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Waters, M. H.; Patmore, L. C.

1983-01-01

Two extensive computer programs were developed. The first, called OPTIM, generates a reference near-optimum vertical profile, and it contains control options so that the effects of various flight constraints on cost performance can be examined. The second, called TRAGEN, is used to simulate an aircraft flying along an optimum or any other vertical reference profile. TRAGEN is used to verify OPTIM's output, examine the effects of uncertainty in the values of parameters (such as prevailing wind) which govern the optimum profile, or compare the cost performance of profiles generated by different techniques. A general description of these programs, the efforts to add special features to them, and sample results of their usage are presented.

Implementation of an optimum profile guidance system on STOLAND

NASA Technical Reports Server (NTRS)

Flanagan, P. F.

1978-01-01

The implementation on the STOLAND airborne digital computer of an optimum profile guidance system for the augmentor wing jet STOL research aircraft is described. Major tasks were to implement the guidance and control logic to airborne computer software and to integrate the module with the existing STOLAND navigation, display, and autopilot routines. The optimum profile guidance system comprises an algorithm for synthesizing mimimum fuel trajectories for a wide range of starting positions in the terminal area and a control law for flying the aircraft automatically along the trajectory. The avionics software developed is described along with a FORTRAN program that was constructed to reflect the modular nature and algorthms implemented in the avionics software.

Design of helicopter rotor blades for optimum dynamic characteristics

NASA Technical Reports Server (NTRS)

Peters, D. A.; Ko, T.; Korn, A. E.; Rossow, M. P.

1982-01-01

The possibilities and the limitations of tailoring blade mass and stiffness distributions to give an optimum blade design in terms of weight, inertia, and dynamic characteristics are investigated. Changes in mass or stiffness distribution used to place rotor frequencies at desired locations are determined. Theoretical limits to the amount of frequency shift are established. Realistic constraints on blade properties based on weight, mass moment of inertia size, strength, and stability are formulated. The extent hub loads can be minimized by proper choice of EL distribution is determined. Configurations that are simple enough to yield clear, fundamental insights into the structural mechanisms but which are sufficiently complex to result in a realistic result for an optimum rotor blade are emphasized.

Simulation and optimum design of hybrid solar-wind and solar-wind-diesel power generation systems

NASA Astrophysics Data System (ADS)

Zhou, Wei

Solar and wind energy systems are considered as promising power generating sources due to its availability and topological advantages in local power generations. However, a drawback, common to solar and wind options, is their unpredictable nature and dependence on weather changes, both of these energy systems would have to be oversized to make them completely reliable. Fortunately, the problems caused by variable nature of these resources can be partially overcome by integrating these two resources in a proper combination to form a hybrid system. However, with the increased complexity in comparison with single energy systems, optimum design of hybrid system becomes more complicated. In order to efficiently and economically utilize the renewable energy resources, one optimal sizing method is necessary. This thesis developed an optimal sizing method to find the global optimum configuration of stand-alone hybrid (both solar-wind and solar-wind-diesel) power generation systems. By using Genetic Algorithm (GA), the optimal sizing method was developed to calculate the system optimum configuration which offers to guarantee the lowest investment with full use of the PV array, wind turbine and battery bank. For the hybrid solar-wind system, the optimal sizing method is developed based on the Loss of Power Supply Probability (LPSP) and the Annualized Cost of System (ACS) concepts. The optimization procedure aims to find the configuration that yields the best compromise between the two considered objectives: LPSP and ACS. The decision variables, which need to be optimized in the optimization process, are the PV module capacity, wind turbine capacity, battery capacity, PV module slope angle and wind turbine installation height. For the hybrid solar-wind-diesel system, minimization of the system cost is achieved not only by selecting an appropriate system configuration, but also by finding a suitable control strategy (starting and stopping point) of the diesel generator. The

Optimum conditions for producing Cs2 molecular condensates by stimulated Raman adiabatic passage

NASA Astrophysics Data System (ADS)

Feng, Zhifang; Li, Weidong; Wang, Lirong; Xiao, Liantuan; Jia, Suotang

2009-10-01

The optimum conditions for producing Cs2 molecular condensates from Cs atomic condensates with high transfer efficiency by stimulated Raman adiabatic passage are presented. Under the extended “two-photon” resonance condition, including the two-photon process, the mean-field correction, and the tunneling coupling between two upper excited molecular levels, a high and stable conversion efficiency is realized. The high conversion efficiency could be achieved by following two methods under experimentally less demanding conditions (relatively small effective Rabi frequency for pump laser pulse). One is adjusting the detuning difference between two laser pulses for same effective Rabi frequencies with up to 87.2% transfer efficiency. Another one is adjusting the effective Rabi frequency, the detuning of dump laser for given effective Rabi frequency, and the detuning of pump laser with up to 80.7% transfer efficiency.

Simulation of optimum parameters for GaN MSM UV photodetector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alhelfi, Mohanad A., E-mail: mhad12344@gmail.com; Ahmed, Naser M., E-mail: nas-tiji@yahoo.com; Hashim, M. R., E-mail: roslan@usm.my

2016-07-06

In this study the optimum parameters of GaN M-S-M photodetector are discussed. The evaluation of the photodetector depends on many parameters, the most of the important parameters the quality of the GaN film and others depend on the geometry of the interdigited electrode. In this simulation work using MATLAB software with consideration of the reflection and absorption on the metal contacts, a detailed study involving various electrode spacings (S) and widths (W) reveals conclusive results in device design. The optimum interelectrode design for interdigitated MSM-PD has been specified and evaluated by effect on quantum efficiency and responsivity.

Optimum take-off angle in the long jump.

PubMed

Linthorne, Nicholas P; Guzman, Maurice S; Bridgett, Lisa A

2005-07-01

In this study, we found that the optimum take-off angle for a long jumper may be predicted by combining the equation for the range of a projectile in free flight with the measured relations between take-off speed, take-off height and take-off angle for the athlete. The prediction method was evaluated using video measurements of three experienced male long jumpers who performed maximum-effort jumps over a wide range of take-off angles. To produce low take-off angles the athletes used a long and fast run-up, whereas higher take-off angles were produced using a progressively shorter and slower run-up. For all three athletes, the take-off speed decreased and the take-off height increased as the athlete jumped with a higher take-off angle. The calculated optimum take-off angles were in good agreement with the athletes' competition take-off angles.

Optimum allocation for a dual-frame telephone survey.

PubMed

Wolter, Kirk M; Tao, Xian; Montgomery, Robert; Smith, Philip J

2015-12-01

Careful design of a dual-frame random digit dial (RDD) telephone survey requires selecting from among many options that have varying impacts on cost, precision, and coverage in order to obtain the best possible implementation of the study goals. One such consideration is whether to screen cell-phone households in order to interview cell-phone only (CPO) households and exclude dual-user household, or to take all interviews obtained via the cell-phone sample. We present a framework in which to consider the tradeoffs between these two options and a method to select the optimal design. We derive and discuss the optimum allocation of sample size between the two sampling frames and explore the choice of optimum p , the mixing parameter for the dual-user domain. We illustrate our methods using the National Immunization Survey , sponsored by the Centers for Disease Control and Prevention.

Growth of single crystals of BaFe12O19 by solid state crystal growth

NASA Astrophysics Data System (ADS)

Fisher, John G.; Sun, Hengyang; Kook, Young-Geun; Kim, Joon-Seong; Le, Phan Gia

2016-10-01

Single crystals of BaFe12O19 are grown for the first time by solid state crystal growth. Seed crystals of BaFe12O19 are buried in BaFe12O19+1 wt% BaCO3 powder, which are then pressed into pellets containing the seed crystals. During sintering, single crystals of BaFe12O19 up to ∼130 μm thick in the c-axis direction grow on the seed crystals by consuming grains from the surrounding polycrystalline matrix. Scanning electron microscopy-energy dispersive spectroscopy analysis shows that the single crystal and the surrounding polycrystalline matrix have the same chemical composition. Micro-Raman scattering shows the single crystal to have the BaFe12O19 structure. The optimum growth temperature is found to be 1200 °C. The single crystal growth behavior is explained using the mixed control theory of grain growth.

Growth-temperature relation for young-of-the-year ruffe

USGS Publications Warehouse

Edsall, Thomas A.; Selgeby, James H.; DeSorcie, Timothy J.; French, John R. P.

1993-01-01

The ruffe (Gymnocephalus cernuus) was accidentally introduced into the Great Lakes basin from Eurasia and has established a breeding population in the St. Louis River, a major tributary to western Lake Superior. We captured young-of-the-year ruffe in the St. Louis River; acclimated groups of 90-91 fish to test temperatures of 7, 10, 15, 20, and 25°C; and fed them ad libitum for 42 days at those temperatures. Ruffe grew at all five temperatures, but the optimum temperature for growth was about 21°C. Because the optimum temperature for growth of walleye (Stizostedion vitreum), sauger (Stizoste-dion canadense), and yellow perch (Perca flavescens) is about 22°C, ruffe will probably attempt to share their thermal habitat. A recent survey of the St. Louis River revealed that yellow perch and small forage fish declined sharply as ruffe abundance increased. A similar decline in yellow perch abundance in Lakes Michigan, Huron, and Erie would seriously affect the fisheries in these lakes.

Optimum structural design with plate bending elements - A survey

NASA Technical Reports Server (NTRS)

Haftka, R. T.; Prasad, B.

1981-01-01

A survey is presented of recently published papers in the field of optimum structural design of plates, largely with respect to the minimum-weight design of plates subject to such constraints as fundamental frequency maximization. It is shown that, due to the availability of powerful computers, the trend in optimum plate design is away from methods tailored to specific geometry and loads and toward methods that can be easily programmed for any kind of plate, such as finite element methods. A corresponding shift is seen in optimization from variational techniques to numerical optimization algorithms. Among the topics covered are fully stressed design and optimality criteria, mathematical programming, smooth and ribbed designs, design against plastic collapse, buckling constraints, and vibration constraints.

Optimum routing of freight in urban environments under normal operations and disruptions : final report.

DOT National Transportation Integrated Search

2016-12-27

The complexity and dynamics of multimodal freight transportation together with the unpredictability of incidents, disruptions and demand changes make the optimum routing of freight a challenging task. Optimum routing decisions in a multimodal transpo...

Methodology for the determination of optimum power of a Thermal Power Plant (TPP) by biogas from sanitary landfill.

PubMed

Silva, Tiago Rodrigo; Barros, Regina Mambeli; Tiago Filho, Geraldo Lúcio; Dos Santos, Ivan Felipe Silva

2017-07-01

This study aimed to determine theoretically, the electrical optimum power of LFG using the maximum net benefit (MNB) methodology, and taking into consideration the economic, demographic, and regional aspects of the Inter municipal Consortium of the Micro-region of the High Sapucaí for Sanitary Landfill (CIMASAS, as acronym in Portuguese), that is located in the southern part of the State of Minas Gerais, Brazil. To this end, the prognosis for a 20-year period of household solid waste generation in this region was estimated and quantified based on population data, in order to estimate the LFG production and the energy that can be generated. From this point, the optimum power for thermal power plant (TPP) by LFG was determined. The results indicated that the landfill in this region could produce more 66,293,282m 3 CH 4 (with maximum power of 997kW in 2036) in twenty years and that there would be no economic viability to generate energy from LFG, because the Net Present Value (NPV) would not be positive. The smallest population to that can achieve a minimum attractiveness rate (MAR) of 15% should be 3,700,000 inhabitants under the conditions studied. Considering the Brazilian National Electric Energy Agency (ANEEL) Resolutions, it would be 339,000 inhabitants with an installed power of 440kW. In addition, the outcome of the CIMASAS case-study demonstrated the applicability of MNB methodology for the determination of TPP optimum power. Copyright © 2017 Elsevier Ltd. All rights reserved.

Achieving pH control in microalgal cultures through fed-batch addition of stoichiometrically-balanced growth media

PubMed Central

2013-01-01

Background Lack of accounting for proton uptake and secretion has confounded interpretation of the stoichiometry of photosynthetic growth of algae. This is also problematic for achieving growth of microalgae to high cell concentrations which is necessary to improve productivity and the economic feasibility of commercial-scale chemical production systems. Since microalgae are capable of consuming both nitrate and ammonium, this represents an opportunity to balance culture pH based on a nitrogen feeding strategy that does not utilize gas-phase CO2 buffering. Stoichiometry suggests that approximately 36 weight%N-NH4+ (balance nitrogen as NO3-) would minimize the proton imbalance and permit high-density photoautotrophic growth as it does in higher plant tissue culture. However, algal media almost exclusively utilize nitrate, and ammonium is often viewed as ‘toxic’ to algae. Results The microalgae Chlorella vulgaris and Chlamydomonas reinhardtii exclusively utilize ammonium when both ammonium and nitrate are provided during growth on excess CO2. The resulting proton imbalance from preferential ammonium utilization causes the pH to drop too low to sustain further growth when ammonium was only 9% of the total nitrogen (0.027 gN-NH4+/L). However, providing smaller amounts of ammonium sequentially in the presence of nitrate maintained the pH of a Chlorella vulgaris culture for improved growth on 0.3 gN/L to 5 gDW/L under 5% CO2 gas-phase supplementation. Bioreactor pH dynamics are shown to be predictable based on simple nitrogen assimilation as long as there is sufficient CO2 availability. Conclusions This work provides both a media formulation and a feeding strategy with a focus on nitrogen metabolism and regulation to support high-density algal culture without buffering. The instability in culture pH that is observed in microalgal cultures in the absence of buffers can be overcome through alternating utilization of ammonium and nitrate. Despite the highly regulated

Generation of optimum vertical profiles for an advanced flight management system

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Waters, M. H.

1981-01-01

Algorithms for generating minimum fuel or minimum cost vertical profiles are derived and examined. The option for fixing the time of flight is included in the concepts developed. These algorithms form the basis for the design of an advanced on-board flight management system. The variations in the optimum vertical profiles (resulting from these concepts) due to variations in wind, takeoff mass, and range-to-destination are presented. Fuel savings due to optimum climb, free cruise altitude, and absorbing delays enroute are examined.

Effect of Retention in First Grade on Children's Achievement Trajectories over 4 Years: A Piecewise Growth Analysis Using Propensity Score Matching

ERIC Educational Resources Information Center

Wu, Wei; West, Stephen G.; Hughes, Jan N.

2008-01-01

The authors investigated the relatively short-term and longer term effects of grade retention in 1st grade on the growth of mathematics and reading achievement over 4 years. The authors initially identified a large multiethnic sample (n = 784) of children who were below the median in literacy at school entrance. From this sample, the authors…

Optimizing amorphous indium zinc oxide film growth for low residual stress and high electrical conductivity

NASA Astrophysics Data System (ADS)

Kumar, Mukesh; Sigdel, A. K.; Gennett, T.; Berry, J. J.; Perkins, J. D.; Ginley, D. S.; Packard, C. E.

2013-10-01

With recent advances in flexible electronics, there is a growing need for transparent conductors with optimum conductivity tailored to the application and nearly zero residual stress to ensure mechanical reliability. Within amorphous transparent conducting oxide (TCO) systems, a variety of sputter growth parameters have been shown to separately impact film stress and optoelectronic properties due to the complex nature of the deposition process. We apply a statistical design of experiments (DOE) approach to identify growth parameter-material property relationships in amorphous indium zinc oxide (a-IZO) thin films and observed large, compressive residual stresses in films grown under conditions typically used for the deposition of highly conductive samples. Power, growth pressure, oxygen partial pressure, and RF power ratio (RF/(RF + DC)) were varied according to a full-factorial test matrix and each film was characterized. The resulting regression model and analysis of variance (ANOVA) revealed significant contributions to the residual stress from individual growth parameters as well as interactions of different growth parameters, but no conditions were found within the initial growth space that simultaneously produced low residual stress and high electrical conductivity. Extrapolation of the model results to lower oxygen partial pressures, combined with prior knowledge of conductivity-growth parameter relationships in the IZO system, allowed the selection of two promising growth conditions that were both empirically verified to achieve nearly zero residual stress and electrical conductivities >1480 S/cm. This work shows that a-IZO can be simultaneously optimized for high conductivity and low residual stress.

Optimum moisture levels for biodegradation of mortality composting envelope materials.

PubMed

Ahn, H K; Richard, T L; Glanville, T D

2008-01-01

Moisture affects the physical and biological properties of compost and other solid-state fermentation matrices. Aerobic microbial systems experience different respiration rates (oxygen uptake and CO2 evolution) as a function of moisture content and material type. In this study the microbial respiration rates of 12 mortality composting envelope materials were measured by a pressure sensor method at six different moisture levels. A wide range of respiration (1.6-94.2mg O2/g VS-day) rates were observed for different materials, with alfalfa hay, silage, oat straw, and turkey litter having the highest values. These four envelope materials may be particularly suitable for improving internal temperature and pathogen destruction rates for disease-related mortality composting. Optimum moisture content was determined based on measurements across a range that spans the maximum respiration rate. The optimum moisture content of each material was observed near water holding capacity, which ranged from near 60% to over 80% on a wet basis for all materials except a highly stabilized soil compost blend (optimum around 25% w.b.). The implications of the results for moisture management and process control strategies during mortality composting are discussed.

Microevolution of the photosynthetic temperature optimum in relation to the elevational complex gradient

Treesearch

John H. Fryer; F. Thomas Ledig

1972-01-01

Balsam fir seedlings were grown under uniform conditions from seed collected along an elevational gradient in the White Mountains of New Hampshire. Photosynthetic temperature optimum of the seedlings decreased with increasing elevation of the seed source. The change in temperature optimum with elevation was similar to the adiabatic lapse rate, suggesting a precise...

Optimum efficiency lidar sensing of multilayer hydrometeors through a turbid atmosphere

NASA Astrophysics Data System (ADS)

Evgenieva, Ts T.; Gurdev, L. L.

2018-03-01

The detected lidar return power is a basic factor determining the brightness of the detected lidar images and the signal-to-noise ratio (SNR) of a given measurement. At equal other characteristics, the laser radiation wavelength should influence the lidar return signal and assume an optimum value depending on the specificity of the objects investigated. As such a problem had not been considered systematically, we recently began developing a modeling approach to solving it, based on evaluating the mean and the noisy lidar profiles and the SNR profile of the measurement along the lidar line of sight by using the lidar equation and well known realistic models of the atmospheric objects and background. The main purpose of the present work is to estimate by numerical modeling the detectability of the lidar return from different distances and multilayer cirrus clouds, depending on the laser radiation wavelengths. The results obtained confirm the expectations that at a higher atmospheric turbidity, a relatively higher sensing efficiency (return power) is achievable by longer-wavelength laser radiation, within the NIR range.

Optimum design point for a closed-cycle OTEC system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ikegami, Yasuyuki; Uehara, Haruo

1994-12-31

Performance analysis is performed for optimum design point of a closed-cycle Ocean Thermal Energy Conversion (OTEC) system. Calculations are made for an OTEC model plant with a gross power of 100 MW, which was designed by the optimization method proposed by Uehara and Ikegami for the design conditions of 21 C--29 C warm sea water temperature and 4 C cold sea water temperature. Ammonia is used as working fluid. Plate type evaporator and condenser are used as heat exchangers. The length of the cold sea water pipe is 1,000 m. This model plant is a floating-type OTEC plant. The objectivemore » function of optimum design point is defined as the total heat transfer area of heat exchangers per the annual net power.« less

Optimum harvest maturity for Leymus chinensis seed.

PubMed

Lin, Jixiang; Wang, Yingnan; Qi, Mingming; Li, Xiaoyu; Yang, Chunxue; Wang, Yongcui; Mu, Chunsheng

2016-06-15

Timely harvest is critical to achieve maximum seed viability and vigour in agricultural production. However, little information exists concerning how to reap the best quality seeds of Leymus chinensis, which is the dominant and most promising grass species in the Songnen Grassland of Northern China. The objective of this study was to investigate and evaluate possible quality indices of the seeds at different days after peak anthesis. Seed quality at different development stages was assessed by the colours of the seed and lemmas, seed weight, moisture content, electrical conductivity of seed leachate and germination indices. Two consecutive years of experimental results showed that the maximum seed quality was recorded at 39 days after peak anthesis. At this date, the colours of the seed and lemmas reached heavy brown and yellow, respectively. The seed weight was highest and the moisture content and the electrical conductivity of seed leachate were lowest. In addition, the seed also reached its maximum germination percentage and energy at this stage, determined using a standard germination test (SGT) and accelerated ageing test (AAT). Thus, Leymus chinensis can be harvested at 39 days after peak anthesis based on the changes in parameters. Colour identification can be used as an additional indicator to provide a more rapid and reliable measure of optimum seed maturity; approximately 10 days after the colour of the lemmas reached yellow and the colour of the seed reached heavy brown, the seed of this species was suitable for harvest. © 2016. Published by The Company of Biologists Ltd.

Optimum harvest maturity for Leymus chinensis seed

PubMed Central

Lin, Jixiang; Wang, Yingnan; Qi, Mingming; Li, Xiaoyu; Yang, Chunxue; Wang, Yongcui

2016-01-01

ABSTRACT Timely harvest is critical to achieve maximum seed viability and vigour in agricultural production. However, little information exists concerning how to reap the best quality seeds of Leymus chinensis, which is the dominant and most promising grass species in the Songnen Grassland of Northern China. The objective of this study was to investigate and evaluate possible quality indices of the seeds at different days after peak anthesis. Seed quality at different development stages was assessed by the colours of the seed and lemmas, seed weight, moisture content, electrical conductivity of seed leachate and germination indices. Two consecutive years of experimental results showed that the maximum seed quality was recorded at 39 days after peak anthesis. At this date, the colours of the seed and lemmas reached heavy brown and yellow, respectively. The seed weight was highest and the moisture content and the electrical conductivity of seed leachate were lowest. In addition, the seed also reached its maximum germination percentage and energy at this stage, determined using a standard germination test (SGT) and accelerated ageing test (AAT). Thus, Leymus chinensis can be harvested at 39 days after peak anthesis based on the changes in parameters. Colour identification can be used as an additional indicator to provide a more rapid and reliable measure of optimum seed maturity; approximately 10 days after the colour of the lemmas reached yellow and the colour of the seed reached heavy brown, the seed of this species was suitable for harvest. PMID:27170257

A systematic approach for locating optimum sites

Treesearch

Angel Ramos; Isabel Otero

1979-01-01

The basic information collected for landscape planning studies may be given the form of a "s x m" matrix, where s is the number of landscape units and m the number of data gathered for each unit. The problem of finding the optimum location for a given project is translated in the problem of ranking the series of vectors in the matrix which represent landscape...

Binding efficiency of recombinant collagen-binding basic fibroblast growth factors (CBD-bFGFs) and their promotion for NIH-3T3 cell proliferation.

PubMed

Wu, Zhenxu; Zhou, Yulai; Chen, Li; Hu, Mingxin; Wang, Yu; Li, Linlong; Wang, Zongliang; Zhang, Peibiao

2018-03-01

The recombinant basic fibroblast growth factor (bFGF) containing collagen-binding domain (CBD) has been found to be a potential therapeutic factor in tissue regeneration. However, its binding efficiency and quantification remain uncertain. In this research, massive recombinant bFGFs with good bioactivity for enhancing the proliferation of NIH-3T3 cells were achieved. An ELISA-based quantitative method was set up to investigate the binding efficiency of CBD-bFGFs on collagen films. It indicated that the CBDs significantly increased the collagen-binding ability of bFGF (P < .05), with the optimum binding condition first determined to be in the pH range of 7.5-9.5 (P < .05). Then, the relevant equations to calculate the binding density of bFGF, C-bFGF, and V-bFGF were acquired. Analysis confirmed that the bioactivity of immobilized bFGFs was well correlated with the density of growth factor on collagen films. Based on this research, the density of growth factor is a logical and applicable dosage unit for quantification of binding efficiency of growth factors, rather than traditional concentration of soluble growth factors in tissue engineering applications. © 2018 Wiley Periodicals, Inc.

Adaptation, Growth, and Resilience in Biological Distribution Networks

NASA Astrophysics Data System (ADS)

Ronellenfitsch, Henrik; Katifori, Eleni

Highly optimized complex transport networks serve crucial functions in many man-made and natural systems such as power grids and plant or animal vasculature. Often, the relevant optimization functional is nonconvex and characterized by many local extrema. In general, finding the global, or nearly global optimum is difficult. In biological systems, it is believed that such an optimal state is slowly achieved through natural selection. However, general coarse grained models for flow networks with local positive feedback rules for the vessel conductivity typically get trapped in low efficiency, local minima. We show how the growth of the underlying tissue, coupled to the dynamical equations for network development, can drive the system to a dramatically improved optimal state. This general model provides a surprisingly simple explanation for the appearance of highly optimized transport networks in biology such as plant and animal vasculature. In addition, we show how the incorporation of spatially collective fluctuating sources yields a minimal model of realistic reticulation in distribution networks and thus resilience against damage.

Generating AN Optimum Treatment Plan for External Beam Radiation Therapy.

NASA Astrophysics Data System (ADS)

Kabus, Irwin

1990-01-01

The application of linear programming to the generation of an optimum external beam radiation treatment plan is investigated. MPSX, an IBM linear programming software package was used. All data originated from the CAT scan of an actual patient who was treated for a pancreatic malignant tumor before this study began. An examination of several alternatives for representing the cross section of the patient showed that it was sufficient to use a set of strategically placed points in the vital organs and tumor and a grid of points spaced about one half inch apart for the healthy tissue. Optimum treatment plans were generated from objective functions representing various treatment philosophies. The optimum plans were based on allowing for 216 external radiation beams which accounted for wedges of any size. A beam reduction scheme then reduced the number of beams in the optimum plan to a number of beams small enough for implementation. Regardless of the objective function, the linear programming treatment plan preserved about 95% of the patient's right kidney vs. 59% for the plan the hospital actually administered to the patient. The clinician, on the case, found most of the linear programming treatment plans to be superior to the hospital plan. An investigation was made, using parametric linear programming, concerning any possible benefits derived from generating treatment plans based on objective functions made up of convex combinations of two objective functions, however, this proved to have only limited value. This study also found, through dual variable analysis, that there was no benefit gained from relaxing some of the constraints on the healthy regions of the anatomy. This conclusion was supported by the clinician. Finally several schemes were found that, under certain conditions, can further reduce the number of beams in the final linear programming treatment plan.

Achieving and documenting closure in plant growth facilities

NASA Technical Reports Server (NTRS)

Knott, W. M.; Sager, John C.; Wheeler, Ray

1992-01-01

As NASA proceeds with its effort to develop a Controlled Ecological Life Support System (CELSS) that will provide life support to crews during long duration space missions, it must address the question of facility and system closure. The concept of closure as it pertains to CELSS and engineering specifications, construction problems and monitoring procedures used in the development and operation of a closed plant growth facility for the CELSS program are described. A plant growth facility is one of several modules required for a CELSS. A prototype of this module at Kennedy Space Center is the large (7m tall x 3.5m diameter) Biomass Production Chamber (BPC), the central facility of the CELSS Breadboard Project. The BPC is atmospherically sealed to a leak rate of approximately 5 percent of its total volume per 24 hours. This paper will discuss the requirements for atmospheric closure in the facility, present CO2 and trace gas data from initial tests of the BPC with and without plants, and describe how the chamber was sealed atmospherically. Implications that research conducted in this type of facility will have for the CELSS program are discussed.

Parallel operation of NH3 screw compressors - the optimum way

NASA Astrophysics Data System (ADS)

Pijnenburg, B.; Ritmann, J.

2015-08-01

The use of more smaller industrial NH3 screw compressors operating in parallel seems to offer the optimum way when it comes to fulfilling maximum part load efficiency, increased redundancy and other highly requested features in the industrial refrigeration industry today. Parallel operation in an optimum way can be selected to secure continuous operation and can in most applications be configured to ensure lower overall operating economy. New compressors are developed to meet requirements for flexibility in operation and are controlled in an intelligent way. The intelligent control system keeps focus on all external demands, but yet striving to offer always the lowest possible absorbed power, including in future scenarios with connection to smart grid.

Techniques for evaluating optimum data center operation

DOEpatents

Hamann, Hendrik F.; Rodriguez, Sergio Adolfo Bermudez; Wehle, Hans-Dieter

2017-06-14

Techniques for modeling a data center are provided. In one aspect, a method for determining data center efficiency is provided. The method includes the following steps. Target parameters for the data center are obtained. Technology pre-requisite parameters for the data center are obtained. An optimum data center efficiency is determined given the target parameters for the data center and the technology pre-requisite parameters for the data center.

The development of science achievement in middle and high school. Individual differences and school effects.

PubMed

Ma, Xin; Wilkins, Jesse L M

2002-08-01

Using data from the Longitudinal Study of American Youth (LSAY), hierarchical linear models (HLMs) were used to model the growth of student science achievement in three areas (biology, physical science, and environmental science) during middle and high school. Results showed significant growth in science achievement across all areas. The growth was quadratic across all areas, with rapid growth at the beginning grades of middle school but slow growth at the ending grades of high school. At the student level, socioeconomic status (SES) and age were related to the rate of growth in all areas. There were no gender differences in the rate of growth in any of the three areas. At the school level, variables associated with school context (school mean SES and school size) and variables associated with school climate (principal leadership, academic expectation, and teacher autonomy) were related to the growth in science achievement. Initial (Grade 7) status in science achievement was not associated with the rate of growth in science achievement among either students or schools in any of the three areas.

Optimum-AIV: A planning and scheduling system for spacecraft AIV

NASA Technical Reports Server (NTRS)

Arentoft, M. M.; Fuchs, Jens J.; Parrod, Y.; Gasquet, Andre; Stader, J.; Stokes, I.; Vadon, H.

1991-01-01

A project undertaken for the European Space Agency (ESA) is presented. The project is developing a knowledge based software system for planning and scheduling of activities for spacecraft assembly, integration, and verification (AIV). The system extends into the monitoring of plan execution and the plan repair phase. The objectives are to develop an operational kernel of a planning, scheduling, and plan repair tool, called OPTIMUM-AIV, and to provide facilities which will allow individual projects to customize the kernel to suit its specific needs. The kernel shall consist of a set of software functionalities for assistance in initial specification of the AIV plan, in verification and generation of valid plans and schedules for the AIV activities, and in interactive monitoring and execution problem recovery for the detailed AIV plans. Embedded in OPTIMUM-AIV are external interfaces which allow integration with alternative scheduling systems and project databases. The current status of the OPTIMUM-AIV project, as of Jan. 1991, is that a further analysis of the AIV domain has taken place through interviews with satellite AIV experts, a software requirement document (SRD) for the full operational tool was approved, and an architectural design document (ADD) for the kernel excluding external interfaces is ready for review.

An Application of Calculus: Optimum Parabolic Path Problem

ERIC Educational Resources Information Center

Atasever, Merve; Pakdemirli, Mehmet; Yurtsever, Hasan Ali

2009-01-01

A practical and technological application of calculus problem is posed to motivate freshman students or junior high school students. A variable coefficient of friction is used in modelling air friction. The case in which the coefficient of friction is a decreasing function of altitude is considered. The optimum parabolic path for a flying object…

Optimum Design of High-Speed Prop-Rotors

NASA Technical Reports Server (NTRS)

Chattopadhyay, Aditi; McCarthy, Thomas Robert

1993-01-01

An integrated multidisciplinary optimization procedure is developed for application to rotary wing aircraft design. The necessary disciplines such as dynamics, aerodynamics, aeroelasticity, and structures are coupled within a closed-loop optimization process. The procedure developed is applied to address two different problems. The first problem considers the optimization of a helicopter rotor blade and the second problem addresses the optimum design of a high-speed tilting proprotor. In the helicopter blade problem, the objective is to reduce the critical vibratory shear forces and moments at the blade root, without degrading rotor aerodynamic performance and aeroelastic stability. In the case of the high-speed proprotor, the goal is to maximize the propulsive efficiency in high-speed cruise without deteriorating the aeroelastic stability in cruise and the aerodynamic performance in hover. The problems studied involve multiple design objectives; therefore, the optimization problems are formulated using multiobjective design procedures. A comprehensive helicopter analysis code is used for the rotary wing aerodynamic, dynamic and aeroelastic stability analyses and an algorithm developed specifically for these purposes is used for the structural analysis. A nonlinear programming technique coupled with an approximate analysis procedure is used to perform the optimization. The optimum blade designs obtained in each case are compared to corresponding reference designs.

Temperature dependent growth, feeding, nutritional condition and aerobic metabolism of juvenile spiny lobster, Sagmariasus verreauxi.

PubMed

Fitzgibbon, Quinn P; Simon, Cedric J; Smith, Gregory G; Carter, Chris G; Battaglene, Stephen C

2017-05-01

We examined the effects of temperature on the growth, feeding, nutritional condition and aerobic metabolism of juvenile spiny lobster, Sagmariasus verreauxi, in order to determine if temperature acclimated aerobic scope correlates with optimum for growth and to establish the thermal tolerance window for this emerging aquaculture species. Juvenile lobsters (initial weight=10.95±0.47g) were reared (n=7) at temperatures from 11.0 to 28.5°C for 145days. All lobsters survived from 14.5 to 25.0°C while survival was reduced at 11.0°C (86%) and all lobsters died at 28.5°C. Lobster specific growth rate and specific feed consumption displayed a unimodal response with temperature, peaking at 21.5°C. Lobster standard, routine and maximum metabolic rates, and aerobic scope all increased exponentially up to maximum non-lethal temperature. Optimum temperature for growth did not correspond to that for maximum aerobic scope suggesting that aerobic scope is not an effective predictor of the thermal optimum of spiny lobsters. Plateauing of specific feed consumption beyond 21.5°C suggests that temperature dependent growth of lobsters is limited by capacity to ingest or digest sufficient food to meet increasing maintenance metabolic demands at high temperatures. The nutritional condition of lobsters was not influenced by temperature and feed conversion ratio was improved at lower temperatures. These findings add to a growing body of evidence questioning the generality of aerobic scope to describe the physiological thermal boundaries of aquatic ectotherms and suggest that feed intake plays a crucial role in regulating performance at thermal extremes. Copyright © 2017 Elsevier Inc. All rights reserved.

Trends in mechanical fasteners. [considering optimum metric fastener system

NASA Technical Reports Server (NTRS)

Levy, J. B.

1972-01-01

Some of the specialty fasteners which are enjoying increasing usage are: thread rolling screws, self drilling and tapping screws, locking screws, tamperproof fasteners, and flanged bolts and nuts. The development of an optimum metric fastener system is recommended for future fastener manufacturing.

L Band Service Compatibility Part I: Optimum OOBE Compatibility

DOT National Transportation Integrated Search

2014-12-04

Discussion: -- Two Parts - Today we focus on optimum L Band ABC Out of Band Emission into GPS L1, OOBE. - Next ABC meeting will examine GPS-side mitigation of Adjacent Band Interference, ABI. -- Greater Compatibility: OOBE and ABI are distinct but pa...

Photocurrent enhancement of n-type Cu2O electrodes achieved by controlling dendritic branching growth.

PubMed

McShane, Colleen M; Choi, Kyoung-Shin

2009-02-25

Cu(2)O electrodes composed of dendritic crystals were produced electrochemically using a slightly acidic medium (pH 4.9) containing acetate buffer. The buffer played a key role for stabilizing dendritic branching growth as a pH drop during the synthesis prevents formation of morphologically unstable branches and promotes faceted growth. Dendritic branching growth enabled facile coverage of the substrate with Cu(2)O while avoiding growth of a thicker Cu(2)O layer and increasing surface areas. The resulting electrodes showed n-type behavior by generating anodic photocurrent without applying an external bias (zero-bias photocurrent under short-circuit condition) in an Ar-purged 0.02 M K(2)SO(4) solution. The zero-bias photocurrent of crystalline dendritic electrodes was significantly higher than that of the electrodes containing micrometer-size faceted crystals deposited without buffer. In order to enhance photocurrent further a strategy of improving charge-transport properties by increasing dendritic crystal domain size was investigated. Systematic changes in nucleation density and size of the dendritic Cu(2)O crystals were achieved by altering the deposition potential, Cu(2+) concentration, and acetate concentration. Increasing dendritic crystal size consistently resulted in the improvement of photocurrent regardless of the method used to regulate crystal size. The electrode composed of dendritic crystals with the lateral dimension of ca. 12000 microm(2) showed more than 20 times higher zero-bias photocurrent than that composed of dendritic crystals with the lateral dimension of ca. 100 microm(2). The n-type nature of the Cu(2)O electrodes prepared by this study were confirmed by linear sweep voltammetry with chopped light and capacitance measurements (i.e., Mott-Schottky plots). The flatband potential in a 0.2 M K(2)SO(4) solution (pH 6) was estimated to be -0.78 vs Ag/AgCl reference electrode. The IPCE measured without applying an external bias was approximately 1

A methodology for selecting optimum organizations for space communities

NASA Technical Reports Server (NTRS)

Ragusa, J. M.

1978-01-01

This paper suggests that a methodology exists for selecting optimum organizations for future space communities of various sizes and purposes. Results of an exploratory study to identify an optimum hypothetical organizational structure for a large earth-orbiting multidisciplinary research and applications (R&A) Space Base manned by a mixed crew of technologists are presented. Since such a facility does not presently exist, in situ empirical testing was not possible. Study activity was, therefore, concerned with the identification of a desired organizational structural model rather than the empirical testing of it. The principal finding of this research was that a four-level project type 'total matrix' model will optimize the effectiveness of Space Base technologists. An overall conclusion which can be reached from the research is that application of this methodology, or portions of it, may provide planning insights for the formal organizations which will be needed during the Space Industrialization Age.

An efficient and practical approach to obtain a better optimum solution for structural optimization

NASA Astrophysics Data System (ADS)

Chen, Ting-Yu; Huang, Jyun-Hao

2013-08-01

For many structural optimization problems, it is hard or even impossible to find the global optimum solution owing to unaffordable computational cost. An alternative and practical way of thinking is thus proposed in this research to obtain an optimum design which may not be global but is better than most local optimum solutions that can be found by gradient-based search methods. The way to reach this goal is to find a smaller search space for gradient-based search methods. It is found in this research that data mining can accomplish this goal easily. The activities of classification, association and clustering in data mining are employed to reduce the original design space. For unconstrained optimization problems, the data mining activities are used to find a smaller search region which contains the global or better local solutions. For constrained optimization problems, it is used to find the feasible region or the feasible region with better objective values. Numerical examples show that the optimum solutions found in the reduced design space by sequential quadratic programming (SQP) are indeed much better than those found by SQP in the original design space. The optimum solutions found in a reduced space by SQP sometimes are even better than the solution found using a hybrid global search method with approximate structural analyses.

Optimum operation of restoration techniques for eutrophic water bodies

NASA Astrophysics Data System (ADS)

Hagen, N. M.; Kleeberg, H.-B.

1994-05-01

Operating rules have been applied in water resources management for a long time in order to control and supply a required quantity (volume) of water. The operating rules have to guarantee the optimum management of the reservoir(s). The quality of the stored water has been satisfactory for the desired utilization up to the sixties. Due to the deterioration of reservoir water quality through human impacts, however, increased attention had to be paid since. Eutrophication of stagnant waters is still an unsolved problem. Through means of various restoration techniques, i.e., dilution/flushing or hypolimnetic withdrawal, the quality of the stored water can be improved. Continuous operation or appropriate time or depth variant operating rules are required to achieve this goal. The paper presents such rules for long-term operation. They have been established for the first time and can he represented in two or three-dimensional graphs depending on the number of included components (e.g., actual water storage and quality). The ‘quality operating rules’ take into account the dynamics of the processes in aquatic ecosystems. Simplifications with regard to application and acceptance (e.g., clarity) are developed and tested. The general validity and efficiency of the operating rules have been proved in a case study (a multi-purpose reservoir) and a fictitious lake.

Optical restoration of images blurred by atmospheric turbulence using optimum filter theory.

PubMed

Horner, J L

1970-01-01

The results of optimum filtering from communications theory have been applied to an image restoration problem. Photographic film imagery, degraded by long-term artificial atmospheric turbulence, has been restored by spatial filters placed in the Fourier transform plane. The time-averaged point spread function was measured and used in designing the filters. Both the simple inverse filter and the optimum least-mean-square filters were used in the restoration experiments. The superiority of the latter is conclusively demonstrated. An optical analog processor was used for the restoration.

Optimum constrained image restoration filters

NASA Technical Reports Server (NTRS)

Riemer, T. E.; Mcgillem, C. D.

1974-01-01

The filter was developed in Hilbert space by minimizing the radius of gyration of the overall or composite system point-spread function subject to constraints on the radius of gyration of the restoration filter point-spread function, the total noise power in the restored image, and the shape of the composite system frequency spectrum. An iterative technique is introduced which alters the shape of the optimum composite system point-spread function, producing a suboptimal restoration filter which suppresses undesirable secondary oscillations. Finally this technique is applied to multispectral scanner data obtained from the Earth Resources Technology Satellite to provide resolution enhancement. An experimental approach to the problems involving estimation of the effective scanner aperture and matching the ERTS data to available restoration functions is presented.

Optimum threshold selection method of centroid computation for Gaussian spot

NASA Astrophysics Data System (ADS)

Li, Xuxu; Li, Xinyang; Wang, Caixia

2015-10-01

Centroid computation of Gaussian spot is often conducted to get the exact position of a target or to measure wave-front slopes in the fields of target tracking and wave-front sensing. Center of Gravity (CoG) is the most traditional method of centroid computation, known as its low algorithmic complexity. However both electronic noise from the detector and photonic noise from the environment reduces its accuracy. In order to improve the accuracy, thresholding is unavoidable before centroid computation, and optimum threshold need to be selected. In this paper, the model of Gaussian spot is established to analyze the performance of optimum threshold under different Signal-to-Noise Ratio (SNR) conditions. Besides, two optimum threshold selection methods are introduced: TmCoG (using m % of the maximum intensity of spot as threshold), and TkCoG ( usingμn +κσ n as the threshold), μn and σn are the mean value and deviation of back noise. Firstly, their impact on the detection error under various SNR conditions is simulated respectively to find the way to decide the value of k or m. Then, a comparison between them is made. According to the simulation result, TmCoG is superior over TkCoG for the accuracy of selected threshold, and detection error is also lower.

Optimal population size and endogenous growth.

PubMed

Palivos, T; Yip, C K

1993-01-01

"Many applications in economics require the selection of an objective function which enables the comparison of allocations involving different population sizes. The two most commonly used criteria are the Benthamite and the Millian welfare functions, also known as classical and average utilitarianism, respectively. The former maximizes total utility of the society and thus represents individuals, while the latter maximizes average utility and so represents generations. Edgeworth (1925) was the first to conjecture, that the Benthamite principle leads to a larger population size and a lower standard of living.... The purpose of this paper is to examine Edgeworth's conjecture in an endogenous growth framework in which there are interactions between output and population growth rates. It is shown that, under conditions that ensure an optimum, the Benthamite criterion leads to smaller population and higher output growth rates than the Millian." excerpt

Buried Object Detection Method Using Optimum Frequency Range in Extremely Shallow Underground

NASA Astrophysics Data System (ADS)

Sugimoto, Tsuneyoshi; Abe, Touma

2011-07-01

We propose a new detection method for buried objects using the optimum frequency response range of the corresponding vibration velocity. Flat speakers and a scanning laser Doppler vibrometer (SLDV) are used for noncontact acoustic imaging in the extremely shallow underground. The exploration depth depends on the sound pressure, but it is usually less than 10 cm. Styrofoam, wood (silver fir), and acrylic boards of the same size, different size styrofoam boards, a hollow toy duck, a hollow plastic container, a plastic container filled with sand, a hollow steel can and an unglazed pot are used as buried objects which are buried in sand to about 2 cm depth. The imaging procedure of buried objects using the optimum frequency range is given below. First, the standardized difference from the average vibration velocity is calculated for all scan points. Next, using this result, underground images are made using a constant frequency width to search for the frequency response range of the buried object. After choosing an approximate frequency response range, the difference between the average vibration velocity for all points and that for several points that showed a clear response is calculated for the final confirmation of the optimum frequency range. Using this optimum frequency range, we can obtain the clearest image of the buried object. From the experimental results, we confirmed the effectiveness of our proposed method. In particular, a clear image of the buried object was obtained when the SLDV image was unclear.

Analysis of the Optimum Usage of Slag for the Compressive Strength of Concrete.

PubMed

Lee, Han-Seung; Wang, Xiao-Yong; Zhang, Li-Na; Koh, Kyung-Taek

2015-03-18

Ground granulated blast furnace slag is widely used as a mineral admixture to replace partial Portland cement in the concrete industry. As the amount of slag increases, the late-age compressive strength of concrete mixtures increases. However, after an optimum point, any further increase in slag does not improve the late-age compressive strength. This optimum replacement ratio of slag is a crucial factor for its efficient use in the concrete industry. This paper proposes a numerical procedure to analyze the optimum usage of slag for the compressive strength of concrete. This numerical procedure starts with a blended hydration model that simulates cement hydration, slag reaction, and interactions between cement hydration and slag reaction. The amount of calcium silicate hydrate (CSH) is calculated considering the contributions from cement hydration and slag reaction. Then, by using the CSH contents, the compressive strength of the slag-blended concrete is evaluated. Finally, based on the parameter analysis of the compressive strength development of concrete with different slag inclusions, the optimum usage of slag in concrete mixtures is determined to be approximately 40% of the total binder content. The proposed model is verified through experimental results of the compressive strength of slag-blended concrete with different water-to-binder ratios and different slag inclusions.

Analysis of the Optimum Usage of Slag for the Compressive Strength of Concrete

PubMed Central

Lee, Han-Seung; Wang, Xiao-Yong; Zhang, Li-Na; Koh, Kyung-Taek

2015-01-01

Ground granulated blast furnace slag is widely used as a mineral admixture to replace partial Portland cement in the concrete industry. As the amount of slag increases, the late-age compressive strength of concrete mixtures increases. However, after an optimum point, any further increase in slag does not improve the late-age compressive strength. This optimum replacement ratio of slag is a crucial factor for its efficient use in the concrete industry. This paper proposes a numerical procedure to analyze the optimum usage of slag for the compressive strength of concrete. This numerical procedure starts with a blended hydration model that simulates cement hydration, slag reaction, and interactions between cement hydration and slag reaction. The amount of calcium silicate hydrate (CSH) is calculated considering the contributions from cement hydration and slag reaction. Then, by using the CSH contents, the compressive strength of the slag-blended concrete is evaluated. Finally, based on the parameter analysis of the compressive strength development of concrete with different slag inclusions, the optimum usage of slag in concrete mixtures is determined to be approximately 40% of the total binder content. The proposed model is verified through experimental results of the compressive strength of slag-blended concrete with different water-to-binder ratios and different slag inclusions. PMID:28787998

Tomato growth as affected by root-zone temperature and the addition of gibberellic acid and kinetin to nutrient solutions

NASA Technical Reports Server (NTRS)

Bugbee, B.; White, J. W.; Salisbury, F. B. (Principal Investigator)

1984-01-01

The effect of root-zone temperature on young tomato plants (Lycopersicon esculentum Mill. cv. Heinz 1350) was evaluated in controlled environments using a recirculating solution culture system. Growth rates were measured at root-zone temperatures of 15 degrees, 20 degrees, 25 degrees, and 30 degrees C in a near optimum foliar environment. Optimum growth occurred at 25 degrees to 30 degrees during the first 4 weeks of growth and 20 degrees to 25 degrees during the 5th and 6th weeks. Growth was severely restricted at 15 degrees. Four concentrations of gibberellic acid (GA3) and kinetin were added to the nutrient solution in a separate trial; root-zone temperature was maintained at 15 degrees and 25 degrees. Addition of 15 micromoles GA3 to solutions increased specific leaf area, total leaf area, and dry weight production of plants in both temperature treatments. GA3-induced growth stimulation was greater at 15 degrees than at 25 degrees. GA3 may promote growth by increasing leaf area, enhancing photosynthesis per unit leaf area, or both. Kinetic was not useful in promoting growth at either temperature.

Influence of culture media and environmental factors on mycelial growth and sporulation of Lasiodiplodia theobromae (Pat.) Griffon and Maubl.

PubMed

Saha, A; Mandal, P; Dasgupta, S; Saha, D

2008-05-01

Lasiodiplodia theobromae, a common tea (Camellia sinensis) pathogen, usually does not sporulate or sporulates poorly in common media, which makes spore production difficult. In this study the effects of culture media, carbon source, nitrogen source, temperature, pH and light on mycelial growth and sporulation were evaluated. Among several carbon sources tested, glucose and sucrose were found superior for growth. Potassium nitrate supplemented media showed maximum growth amongst the tested inorganic nitrogen sources while peptone produced maximum growth among the tested organic nitrogen sources. Tea root extract supplemented potato dextrose agar medium was found to be the most suitable for mycelial growth and sporulation of L. theobromae. The fungus grow at temperatures ranging from 40 to 36 degrees C, with optimum growth at 28 degrees C and no growth was noted at 40 degrees C. There was no significant effect of different light period on growth of L. theobromae, but light enhanced sporulation. The fungus grow at pH 3.0-8.0 and optimum growth was observed at pH 6.0. Tea root extract supplemented potato dextrose agar medium with pH 6.0 was the most suitable for production of conidia of L. theobromae at 28 degrees C. Hence this media may be recommended for inoculum production for further studies.

Behavioral Engagement in Learning and Math Achievement over Kindergarten: A Contextual Analysis

ERIC Educational Resources Information Center

Robinson, Keith; Mueller, Anna S.

2014-01-01

Using nationally representative data on 12,462 kindergarten children, this report examines the link between behavioral engagement and math achievement growth during kindergarten. Multilevel models show that students with higher individual engagement tend to experience larger math achievement growth over kindergarten, that classroom engagement…

Comparison of Optimum Interpolation and Cressman Analyses

NASA Technical Reports Server (NTRS)

Baker, W. E.; Bloom, S. C.; Nestler, M. S.

1985-01-01

The development of a state of the art optimum interpolation (O/I) objective analysis procedure for use in numerical weather prediction studies was investigated. A three dimensional multivariate O/I analysis scheme was developed. Some characteristics of the GLAS O/I compared with those of the NMC and ECMWF systems are summarized. Some recent enhancements of the GLAS scheme include a univariate analysis of water vapor mixing ratio, a geographically dependent model prediction error correlation function and a multivariate oceanic surface analysis.

Growth, functional capacities and motivation for achievement and competitiveness in youth basketball: an interdisciplinary approach.

PubMed

Carvalho, Humberto Moreira; Gonçalves, Carlos E; Collins, Dave; Paes, Roberto R

2018-04-01

The interaction of multiple influences on the path to sport success is not yet fully understood by sport scientists. In this study, we examined variation in body size, functional capacities and motivation for achievement, competitiveness and deliberate practice of youth basketball players associated with differences in biological maturity status, chronological age and years of training experience. Reflecting the importance of interactive effects, we examined the relationships between the psychological variables and functional capacities. Fifty-eight male basketball players aged 9.5 to 15.5 years were considered. Variables included chronological age, estimated age at peak height velocity, stature, body mass and sitting height by anthropometry; the Work and Family Orientation and Deliberate Practice Motivation Questionnaires were also used. Finally, the Line Drill test and Yo-Yo Intermittent Recovery level 1 (Yo-Yo IR1) tests were used as functional capacities indicators for basketball. Variance components models derived from series of multilevel linear regression models revealed a substantial variation by maturity status for body size, functional capacities indicators, mastery and will to excel. The influence of estimated maturity status on mastery and will to excel was independent of age and years of experience. In contrast, no relationships were observed between psychological variables and functional capacities indicators. We conclude that growth-related changes are relevant to understanding players´ motivations for achievement, competitiveness and deliberate practice. This should be of interest to those involved in the selection and development of youth basketball players.

Change in optimum genetic algorithm solution with changing band discontinuities and band widths of electrically conducting copolymers

NASA Astrophysics Data System (ADS)

Kaur, Avneet; Bakhshi, A. K.

2010-04-01

The interest in copolymers stems from the fact that they present interesting electronic and optical properties leading to a variety of technological applications. In order to get a suitable copolymer for a specific application, genetic algorithm (GA) along with negative factor counting (NFC) method has recently been used. In this paper, we study the effect of change in the ratio of conduction band discontinuity to valence band discontinuity (Δ Ec/Δ Ev) on the optimum solution obtained from GA for model binary copolymers. The effect of varying bandwidths on the optimum GA solution is also investigated. The obtained results show that the optimum solution changes with varying parameters like band discontinuity and band width of constituent homopolymers. As the ratio Δ Ec/Δ Ev increases, band gap of optimum solution decreases. With increasing band widths of constituent homopolymers, the optimum solution tends to be dependent on the component with higher band gap.

A Simple Inexpensive Bridgman-Stockbarger Crystal Growth System for Organic Materials

NASA Technical Reports Server (NTRS)

Choi, J.; Aggarwal, M. D.; Wang, W. S.; Metzl, R.; Bhat, K.; Penn, Benjamin G.; Frazier, Donald O.

1996-01-01

Direct observation of solid-liquid interface is important for the directional solidification to determine the desired interface shape by controlling the growth parameters. To grow good quality single crystals of novel organic nonlinear optical materials, a simple inexpensive Bridgman-Stockbarger (BS) crystal growth system has been designed and fabricated. Two immiscible liquids have been utilized to create two zones for this crystal growth system. Bulk single crystals of benzil derivative and n-salicylidene-aniline have been successfully grown in this system. The optimum lowering rate has been found to be 0.1 mm/h for the flat interface. Results on the crystal growth and other parameters of the grown crystals are presented.

The temporal distribution of directional gradients under selection for an optimum.

PubMed

Chevin, Luis-Miguel; Haller, Benjamin C

2014-12-01

Temporal variation in phenotypic selection is often attributed to environmental change causing movements of the adaptive surface relating traits to fitness, but this connection is rarely established empirically. Fluctuating phenotypic selection can be measured by the variance and autocorrelation of directional selection gradients through time. However, the dynamics of these gradients depend not only on environmental changes altering the fitness surface, but also on evolution of the phenotypic distribution. Therefore, it is unclear to what extent variability in selection gradients can inform us about the underlying drivers of their fluctuations. To investigate this question, we derive the temporal distribution of directional gradients under selection for a phenotypic optimum that is either constant or fluctuates randomly in various ways in a finite population. Our analytical results, combined with population- and individual-based simulations, show that although some characteristic patterns can be distinguished, very different types of change in the optimum (including a constant optimum) can generate similar temporal distributions of selection gradients, making it difficult to infer the processes underlying apparent fluctuating selection. Analyzing changes in phenotype distributions together with changes in selection gradients should prove more useful for inferring the mechanisms underlying estimated fluctuating selection. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

Optimum decoding and detection of a multiplicative amplitude-encoded watermark

NASA Astrophysics Data System (ADS)

Barni, Mauro; Bartolini, Franco; De Rosa, Alessia; Piva, Alessandro

2002-04-01

The aim of this paper is to present a novel approach to the decoding and the detection of multibit, multiplicative, watermarks embedded in the frequency domain. Watermark payload is conveyed by amplitude modulating a pseudo-random sequence, thus resembling conventional DS spread spectrum techniques. As opposed to conventional communication systems, though, the watermark is embedded within the host DFT coefficients by using a multiplicative rule. The watermark decoding technique presented in the paper is an optimum one, in that it minimizes the bit error probability. The problem of watermark presence assessment, which is often underestimated by state-of-the-art research on multibit watermarking, is addressed too, and the optimum detection rule derived according to the Neyman-Pearson criterion. Experimental results are shown both to demonstrate the validity of the theoretical analysis and to highlight the good performance of the proposed system.

The Interplay of Orthodontics, Periodontics, and Restorative Dentistry to Achieve Aesthetic and Functional Success.

PubMed

Trushkowsky, Richard D; Alsadah, Zainab; Brea, Luis M; Oquendo, Anabella

2015-07-01

Previously dentists focused on repair and maintenance of function. However, the emphasis of many patients and dentists is now on esthetics. Often there is a need for the disciplines of orthodontics, periodontics, restorative dentistry, and maxillofacial surgery to work together in order to achieve optimum results. Currently the sequencing planning process begins with esthetics and then function, structure, and ultimately biology. Copyright © 2015 Elsevier Inc. All rights reserved.

Review of "High-Achieving Students in the Era of NCLB"

ERIC Educational Resources Information Center

Camilli, Gregory

2008-01-01

A recent report from the Fordham Institute considers potential instructional policies for high-achieving students that should be considered in the forthcoming reauthorization of the No Child Left Behind Act. The report finds: 1) achievement growth among high-achieving students has been slower than that of low-achieving students; 2) this trend can…

Some further characteristics of the growth of Naegleria fowleri and N. gruberi in axenic culture.

PubMed

Cerva, L

1978-01-01

The effects of pH, various viscosity of the medium, changed ratio between the concentrations of dissolved and corpuscular components in the medium, and dissolved inorganic salts on the growth of axenic cultures of Naegleria fowleri and N. gruberi have been studied. The cultures were grown in liquid CALYG and BCS media. The pH optimum was 6.5 for N. fowleri and 6.0--6.5 for N. gruberi. No negative influence on the growth of N. fowleri was observed even at 0.5% concentration of highly viscous methylcellulose, whereas the growth of N. gruberi was distinctly inhibited by more than 0.2% of methycellulose. N. fowleri preferred the osmotorphic and N. gruberi phagotrophic nutrition in the given system of cultivation. The growth of both Naegleria species was inhibited by 0.1 N concentration of sodium chloride and potassium chloride without any significant difference in the tolerance. The inhibitory effect of these salts correlated primarily with the concentration of chloride anion. The ability to grow in a medium with increased viscosity and the preference for osmotrophic nutrtion are, besides the higher temperature optimum determined earlier, further characteristics of the pathogenic species N. fowleri.

Optimum structural design with static aeroelastic constraints

NASA Technical Reports Server (NTRS)

Bowman, Keith B; Grandhi, Ramana V.; Eastep, F. E.

1989-01-01

The static aeroelastic performance characteristics, divergence velocity, control effectiveness and lift effectiveness are considered in obtaining an optimum weight structure. A typical swept wing structure is used with upper and lower skins, spar and rib thicknesses, and spar cap and vertical post cross-sectional areas as the design parameters. Incompressible aerodynamic strip theory is used to derive the constraint formulations, and aerodynamic load matrices. A Sequential Unconstrained Minimization Technique (SUMT) algorithm is used to optimize the wing structure to meet the desired performance constraints.

Comparison of Optimum Interpolation and Cressman Analyses

NASA Technical Reports Server (NTRS)

Baker, W. E.; Bloom, S. C.; Nestler, M. S.

1984-01-01

The objective of this investigation is to develop a state-of-the-art optimum interpolation (O/I) objective analysis procedure for use in numerical weather prediction studies. A three-dimensional multivariate O/I analysis scheme has been developed. Some characteristics of the GLAS O/I compared with those of the NMC and ECMWF systems are summarized. Some recent enhancements of the GLAS scheme include a univariate analysis of water vapor mixing ratio, a geographically dependent model prediction error correlation function and a multivariate oceanic surface analysis.

Optimum design calculations for detectors based on ZnSe(Те,О) scintillators

NASA Astrophysics Data System (ADS)

Katrunov, K.; Ryzhikov, V.; Gavrilyuk, V.; Naydenov, S.; Lysetska, O.; Litichevskyi, V.

2013-06-01

Light collection in scintillators ZnSe(X), where X is an isovalent dopant, was studied using Monte Carlo calculations. Optimum design was determined for detectors of "scintillator—Si-photodiode" type, which can involve either one scintillation element or scintillation layers of large area made of small-crystalline grains. The calculations were carried out both for determination of the optimum scintillator shape and for design optimization of light guides, on the surface of which the layer of small-crystalline grains is formed.

Selection of Wavelengths for Optimum Precision in Simultaneous Spectrophotometric Determinations.

ERIC Educational Resources Information Center

DiTusa, Michael R.; Schilt, Alfred A.

1985-01-01

Although many textbooks include a description of simultaneous determinations employing absorption spectrophotometry and treat the mathematics necessary for analytical quantitations, treatment of analytical wavelength selection has been mostly qualitative. Therefore, a general method for selecting wavelengths for optimum precision in simultaneous…

Children's visuospatial memory predicts mathematics achievement through early adolescence.

PubMed

Li, Yaoran; Geary, David C

2017-01-01

A previous study showed that gains in visuospatial memory from first to fifth grade predicted end-of-fifth grade mathematics but not reading achievement, controlling other factors. In this follow up study, these relations were assessed from sixth to ninth grade, inclusive (n = 145). The results showed that growth in visuospatial memory across the elementary school years was related to growth in mathematics achievement after fifth grade, controlling intelligence, the central executive and phonological memory components of working memory, in-class attentive behavior, parental education, and fifth grade mathematics achievement. As found for fifth grade, this relation was not found for reading achievement after fifth grade. In total, the results suggest that visuospatial memory has a unique influence on ease of learning some types of mathematics and that this influence becomes more important across successive grades.

Local growth could be achieved using local innovation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madison, Alison L.

2010-12-19

In a recent column I mentioned that sometimes the solutions to economic growth for our area—and even the nation—are closer than we might think. At the latest Tri-Cities Research District Speaker Series event, this message was reinforced by two commercialization managers at Pacific Northwest National Laboratory. Peter Christensen and Eric Lund are two in a team of seven experts that help connect companies with technologies developed at PNNL. Sometimes they license those technologies to established companies with existing product lines and sometimes they see entirely new companies form around the newly acquired technology’s product potential.

Direct growth of ZnO tetrapod on glass substrate by Chemical Vapor Deposition Technique

NASA Astrophysics Data System (ADS)

Fadzil, M. F. M.; Rahman, R. A.; Azhar, N. E. A.; Aziz, T. N. T. A.; Zulkifli, Z.

2018-03-01

This research demonstrates the growth of ZnO tetrapod structure on glass substrate for different types of flow gas and at different growth temperatures. The study on the morphological structure and electrical properties of ZnO thin film growth by Chemical Vapour Deposition (CVD) technique showed that the optimum growth temperature was obtained at 750°C with ZnO nanotetrapod morphological structure. Introducing Nitrogen gas flow during the growth process exhibited leg-to-leg linking ZnO tetrapods morphology. The electrical properties of ZnO tetrapods film were measured by using two point probes and it shows that, the sample growth in Ar and O2 atmosphere have better I-V characteristic.

There is room for selection in a small local pig breed when using optimum contribution selection: a simulation study.

PubMed

Gourdine, J L; Sørensen, A C; Rydhmer, L

2012-01-01

Selection progress must be carefully balanced against the conservation of genetic variation in small populations of local breeds. Well-defined breeding programs with specified selection traits are rare in local pig breeds. Given the small population size, the focus is often on the management of genetic diversity. However, in local breeds, optimum contribution selection can be applied to control the rate of inbreeding and to avoid reduced performance in traits with high market value. The aim of this study was to assess the extent to which a breeding program aiming for improved product quality in a small local breed would be feasible. We used stochastic simulations to compare 25 scenarios. The scenarios differed in size of population, selection intensity of boars, type of selection (random selection, truncation selection based on BLUP breeding values, or optimum contribution selection based on BLUP breeding values), and heritability of the selection trait. It was assumed that the local breed is used in an extensive system for a high-meat-quality market. The simulations showed that in the smallest population (300 female reproducers), inbreeding increased by 0.8% when selection was performed at random. With optimum contribution selection, genetic progress can be achieved that is almost as great as that with truncation selection based on BLUP breeding values (0.2 to 0.5 vs. 0.3 to 0.5 genetic SD, P < 0.05), but at a considerably decreased rate of inbreeding (0.7 to 1.2 vs. 2.3 to 5.7%, P < 0.01). This confirmation of the potential utilization of OCS even in small populations is important in the context of sustainable management and the use of animal genetic resources.

Sustaining School Achievement in California's Elementary Schools after State Monitoring

ERIC Educational Resources Information Center

McCabe, Molly

2010-01-01

This study examined the Academic Performance Index (API) and Adequate Yearly Progress (AYP) achievement trends between 2004 and 2006 of 58 California public elementary schools after exiting state monitoring and investigated practices for sustaining consistent achievement growth. Statistical methods were used to analyze statewide achievement trends…

Complete remission of liver metastasis in a lung cancer patient with epidermal growth factor mutation achieved with Icotinib

PubMed Central

Zhu, Zhouyu

2016-01-01

A 65‐year‐old Chinese male was referred to our hospital for epidermal growth factor receptor (EGFR)‐mutated advanced non‐small cell lung cancer (NSCLC). Aggressive combined therapy with surgical resection of the right upper lung lesion and chemotherapy was performed. One month later, continued Icotinib treatment was used as magnetic resonance imaging revealed liver metastasis (LM). Interestingly, complete remission of the patient's LM lesions was achieved in six months. To our knowledge, this is the first report documenting a successful case of an NSCLC patient with LM treated with Icotinib after receiving a radical resection for pulmonary carcinoma. Our experience could provide a treatment strategy for patients with similar disease. PMID:27807951

Vegetative Growth of Four Strains of Hericium erinaceus Collected from Different Habitats

PubMed Central

Imtiaj, Ahmed; Jayasinghe, Chandana; Lee, Geon Woo; Shim, Mi Ja; Rho, Hyun-Su; Lee, Hyun Sook; Hur, Hyun; Lee, Min Woong; Lee, U-Youn

2008-01-01

Vegetative growth of four different strains of Hericium erinaceus was observed. The temperature suitable for optimal mycelial growth was determined to be 25℃, with growth observed in the extend temperature range of 20~30℃. The different strains of this mushroom showed distinct pH requirements for their optimum vegetative growth, with the most favorable growth observed at pH 6. Considering vegetative mycelial growth, PDA, YM, Hennerberg, Hamada, and Glucose peptone were the most favorable media, and Czapek Dox, Hoppkins, Glucose tryptone, and Lilly were the most unfavorable media for these mushroom strains. With the exception of lactose, most of the carbon sources assayed demonstrated favorable vegetative growth of H. erinaceus. For mycelial growth, the most suitable nitrogen source was alanine and the most unsuitable was histidine. Oak sawdust medium supplemented with 10~20% rice bran was the best for mycelial growth of the mushroom. PMID:23990739

Atlantic wolf-fish Anarhichas lupus population diversity: growth and maturation.

PubMed

Gunnarsson, Á

2014-02-01

Biological data from 1125 female Atlantic wolf-fish Anarhichas lupus were collected during 2002-2006 at their main spawning and fishing grounds in Iceland. The results demonstrated substantial annual variation in growth and maturity of female A. lupus. The fast growing females mature earlier than the slow growing ones. In addition, females mature at a larger size and greater age in warmer temperatures than colder ones. There was a strong negative relationship between temperature and growth, which may indicate that the sea temperature west of Iceland has risen above the optimum for growth of female A. lupus and thereby reduced the reproductive potential of the species. © 2014 The Fisheries Society of the British Isles.

Evaluation of Amorphous Transformer by Optimum Capacity Selection based on the Load Curve Pattern of Customers

NASA Astrophysics Data System (ADS)

Takagi, Masaaki; Yamamoto, Hiromi; Yamaji, Kenji

Energy loss in transformer is composed of no-load loss and load loss. No-load loss of amorphous transformer (i.e. amorphous metal-based transformer) is less by about 70% compared with traditional transformers (e.g. silicon steel-based transformer). However, amorphous transformers have disadvantages of high cost and high load loss parameter compared with traditional transformers. Furthermore, there are varieties of transformer capacities, and the customers who would buy new transformer have many choices. In this paper, the authors propose an algorithm for optimum transformer selection based on the load curve patterns of customers. It is possible to select the capacity that minimizes the total cost by measuring equivalent load Qe that is the root mean square of load. It becomes clear that amorphous transformer is effective in achieving substantial energy saving compared with traditional transformer.

The Impact of Linking Distinct Achievement Test Scores on the Interpretation of Student Growth in Achievement

ERIC Educational Resources Information Center

Airola, Denise Tobin

2011-01-01

Changes to state tests impact the ability of State Education Agencies (SEAs) to monitor change in performance over time. The purpose of this study was to evaluate the Standardized Performance Growth Index (PGIz), a proposed statistical model for measuring change in student and school performance, across transitions in tests. The PGIz is a…

Endocrine Control of Exaggerated Trait Growth in Rhinoceros Beetles.

PubMed

Zinna, R; Gotoh, H; Brent, C S; Dolezal, A; Kraus, A; Niimi, T; Emlen, D; Lavine, L C

2016-08-01

Juvenile hormone (JH) is a key insect growth regulator frequently involved in modulating phenotypically plastic traits such as caste determination in eusocial species, wing polymorphisms in aphids, and mandible size in stag beetles. The jaw morphology of stag beetles is sexually-dimorphic and condition-dependent; males have larger jaws than females and those developing under optimum conditions are larger in overall body size and have disproportionately larger jaws than males raised under poor conditions. We have previously shown that large males have higher JH titers than small males during development, and ectopic application of fenoxycarb (JH analog) to small males can induce mandibular growth similar to that of larger males. What remains unknown is whether JH regulates condition-dependent trait growth in other insects with extreme sexually selected structures. In this study, we tested the hypothesis that JH mediates the condition-dependent expression of the elaborate horns of the Asian rhinoceros beetle, Trypoxylus dichotomus. The sexually dimorphic head horn of this beetle is sensitive to nutritional state during larval development. Like stag beetles, male rhinoceros beetles receiving copious food produce disproportionately large horns for their body size compared with males under restricted diets. We show that JH titers are correlated with body size during the late feeding and early prepupal periods, but this correlation disappears by the late prepupal period, the period of maximum horn growth. While ectopic application of fenoxycarb during the third larval instar significantly delayed pupation, it had no effect on adult horn size relative to body size. Fenoxycarb application to late prepupae also had at most a marginal effect on relative horn size. We discuss our results in context of other endocrine signals of condition-dependent trait exaggeration and suggest that different beetle lineages may have co-opted different physiological signaling mechanisms to

Influence of culture media and environmental factors on mycelial growth and pycnidial production of Sphaeropsis pyriputrescens.

PubMed

Kim, Y K; Xiao, C L; Rogers, J D

2005-01-01

Sphaeropsis pyriputrescens, the causal agent of Sphaeropsis rot of pears and apples, is a recently described species. In this study the effects of culture media, temperature, water potential, pH and light on mycelial growth and pycnidial production of S. pyriputrescens were evaluated. Apple juice agar and pear juice agar were most suitable for mycelial growth of all six isolates tested. Cornmeal agar was not suitable for either mycelial growth or pycnidial production. The fungus grew from -3 to 25 C, with optimum growth at 20 C and no growth at 30 C. The fungus grew at water potential as low as -5.6 MPa on potassium chloride-amended potato-dextrose agar (PDA). Hyphal extension was not observed at -7.3 MPa after 10 d incubation, but growth resumed when the inoculum plugs were placed on PDA. The fungus grew at pH 3.3-6.3 and optimum growth was at pH 3.3-4.2. No mycelial growth was observed at pH above 7.2 after 10 d incubation, but growth resumed when the inoculum plugs were transferred onto PDA. Regardless of medium tested, few pycnidia formed at 20 C in the dark. Pycnidial production was enhanced significantly by fluorescent light, but continuous light appeared to reduce pycnidial production, depending on the medium. Oatmeal agar (OMA) was most suitable for production of pycnidia and conidia. Pycnidia that formed on 3 wk old OMA cultures at 20 C under 12 h light/12 h dark produced abundant conidia, and the technique is recommended for inoculum production.

The Impact of Assessment for Learning: Benefits and Barriers to Student Achievement

ERIC Educational Resources Information Center

Collins, Natalie M.

2012-01-01

The purpose of this study was to compare growth in student achievement of students in a classroom where the assessment for learning process was either absent from or present in a teacher's practices, and to gather the teacher's and students' perceptions of the benefits and barriers related to growth in student achievement when the…

Do rewards reinforce the growth mindset?: Joint effects of the growth mindset and incentive schemes in a field intervention.

PubMed

Chao, Melody Manchi; Visaria, Sujata; Mukhopadhyay, Anirban; Dehejia, Rajeev

2017-10-01

The current study draws on the motivational model of achievement which has been guiding research on the growth mindset intervention (Dweck & Leggett, 1988) and examines how this intervention interacts with incentive systems to differentially influence performance for high- and low-achieving students in Indian schools that serve low-SES communities. Although, as expected, the growth mindset intervention did interact with incentive systems and prior achievement to influence subsequent academic performance, the existing growth mindset framework cannot fully account for the observed effects. Specifically, we found that the growth mindset intervention did facilitate performance through persistence, but only when the incentive system imparted individuals with a sense of autonomy. Such a facilitation effect was only found among those students who had high prior achievement, but not among those who had underperformed. When the incentive did not impart a sense of autonomy, the growth mindset intervention undermined the performance of those who had high initial achievement. To reconcile these discrepancies and to advance understanding of the impacts of psychological interventions on achievement outcomes, we discuss how the existing theory can be extended and integrated with an identity-based motivation framework (Oyserman & Destin, 2010). We also discuss the implications of our work for future research and practice. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Achievement goal profiles and developments in effort and achievement in upper elementary school.

PubMed

Hornstra, Lisette; Majoor, Marieke; Peetsma, Thea

2017-12-01

The multiple goal perspective posits that certain combinations of achievement goals are more favourable than others in terms of educational outcomes. This study aimed to examine longitudinally whether students' achievement goal profiles and transitions between profiles are associated with developments in self-reported and teacher-rated effort and academic achievement in upper elementary school. Participants were 722 fifth-grade students and their teachers in fifth and sixth grade (N = 68). Students reported on their achievement goals and effort in language and mathematics three times in grade 5 to grade 6. Teachers rated students' general school effort. Achievement scores were obtained from school records. Goal profiles were derived with latent profile and transition analyses. Longitudinal multilevel analyses were conducted. Theoretically favourable goal profiles (high mastery and performance-approach goals, low on performance-avoidance goals), as well as transitions from less to more theoretically favourable goal profiles, were associated with higher levels and more growth in effort for language and mathematics and with stronger language achievement gains. Overall, these results provide support for the multiple goal perspective and show the sustained benefits of favourable goal profiles beyond effects of cognitive ability and background characteristics. © 2017 The Authors. British Journal of Education Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

Swarms: Optimum aggregations of spacecraft

NASA Technical Reports Server (NTRS)

Mayer, H. L.

1980-01-01

Swarms are aggregations of spacecraft or elements of a space system which are cooperative in function, but physically isolated or only loosely connected. For some missions the swarm configuration may be optimum compared to a group of completely independent spacecraft or a complex rigidly integrated spacecraft or space platform. General features of swarms are induced by considering an ensemble of 26 swarms, examples ranging from Earth centered swarms for commercial application to swarms for exploring minor planets. A concept for a low altitude swarm as a substitute for a space platform is proposed and a preliminary design studied. The salient design feature is the web of tethers holding the 30 km swarm in a rigid two dimensional array in the orbital plane. A mathematical discussion and tutorial in tether technology and in some aspects of the distribution of services (mass, energy, and information to swarm elements) are included.

The Optimum Conditions of Foreign Languages in Primary Education

ERIC Educational Resources Information Center

Giannikas, Christina Nicole

2014-01-01

The aim of the paper is to review the primary language learning situation in Europe and shed light on the benefits it carries. Early language learning is the biggest policy development in education and has developed in rapid speed over the past 30 years; this article considers the effects and advantages of the optimum condition of an early start,…

Growth mechanism and microstructure of low defect density InN (0001) In-face thin films on Si (111) substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kehagias, Th.; Dimitrakopulos, G. P.; Koukoula, T.

2013-10-28

Transmission electron microscopy has been employed to analyze the direct nucleation and growth, by plasma-assisted molecular beam epitaxy, of high quality InN (0001) In-face thin films on (111) Si substrates. Critical steps of the heteroepitaxial growth process are InN nucleation at low substrate temperature under excessively high N-flux conditions and subsequent growth of the main InN epilayer at the optimum conditions, namely, substrate temperature 400–450 °C and In/N flux ratio close to 1. InN nucleation occurs in the form of a very high density of three dimensional (3D) islands, which coalesce very fast into a low surface roughness InN film.more » The reduced reactivity of Si at low temperature and its fast coverage by InN limit the amount of unintentional Si nitridation by the excessively high nitrogen flux and good bonding/adhesion of the InN film directly on the Si substrate is achieved. The subsequent overgrowth of the main InN epilayer, in a layer-by-layer growth mode that enhances the lateral growth of InN, reduces significantly the crystal mosaicity and the density of threading dislocations is about an order of magnitude less compared to InN films grown using an AlN/GaN intermediate nucleation/buffer layer on Si. The InN films exhibit the In-face polarity and very smooth atomically stepped surfaces.« less

Induction of sporulation and the influence of time, temperature, and inoculum size on growth in two species of aquatic fungi (Saprolegniales)

USGS Publications Warehouse

Bailey, T.A.; Bradford, K.; Bland, C.E.

1990-01-01

Because the infective stage of most mycoses of aquatic organisms is the zoospore, we attempted to establish optimum conditions under which zoospores could be produced for use in antifungal testing. Optimum sporulation time, incubation time, inoculum size, and growth temperature were determined for each oftwo saprolegniaceous fungi, Achlya flagellata Coker and Saprolegnia hypogyna (Pringsheim) de Bary. Both species produced the largest number of zoospores after 18 hours (51.7 spores/ml for A. jlagellata and 848.0 spores/ml for S. hypogyna), and yielded maximum growth after 48 hours at 22 'C. The recommended test inoculum size for S. hypogyna (5,600 spores/ml was nearly three times that for A. flagellata (2,000 spores/ml),

Trajectories of Math and Reading Achievement in Low Achieving Children in Elementary School: Effects of Early and Later Retention in Grade

PubMed Central

Moser, Stephanie E.; West, Stephen G.; Hughes, Jan N.

2012-01-01

This study investigated the effects of retention or promotion in first grade on growth trajectories in mathematics and reading achievement over the elementary school years (grades 1–5). From a large multiethnic sample (n = 784) of children who were below the median in literacy at school entrance, 363 children who were either promoted (n = 251) or retained (n = 112) in first grade could be successfully matched on 72 background variables. Achievement was measured annually using Woodcock-Johnson W scores; scores of retained children were shifted back one year to permit same-grade comparisons. Using longitudinal growth curve analysis, trajectories of math and reading scores for promoted and retained children were compared. Retained children received a one year boost in achievement; this boost fully dissipated by the end of elementary school. The pattern of subsequent retention in grades 2, 3 and 4 and placement in special education of the sample during the elementary school years is also described and their effects are explored. Policy implications for interventions for low achieving children are considered. PMID:23335818

Use of geostatistics in planning optimum drilling program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghose S.

1989-08-01

Application of geostatistics in the natural resources industry is well established. In a typical process of estimation, the statistically dependent geological data are used to predict the characteristics of a deposit. The estimator used is the best linear unbiased estimator (or BLUE), and a numerical factor of confidence is also provided. The natural inhomogeneity and anisotropy of a deposit are also quantified with preciseness. Drilling is the most reliable way of obtaining data for mining and related industries. However, it is often difficult to decide what is the optimum number of drill holes necessary for evaluation. In this paper, sequentialmore » measures of percent variation at 95% confidence level of a geological variable have been used to decipher economically optimum drilling density. A coal reserve model has been used to illustrate the method and findings. Fictitious drilling data were added (within the domain of population characteristics) in stages, to obtain a point of stability, beyond which the gain was significant (diminishing marginal benefit). The final relations are established by graphically projecting and comparing two variables - cost and precision. By mapping the percent variation at each stage, the localized areas of discrepancies can be identified. These are the locations where additional drilling is needed. The system can be controlled if performed at progressive stages and the preciseness toward stability is monitored.« less

Simulated Optimum Sowing Date for Forage Pearl Millet Cultivars in Multilocation Trials in Brazilian Semi-Arid Region.

PubMed

Santos, Rafael D; Boote, Kenneth J; Sollenberger, Lynn E; Neves, Andre L A; Pereira, Luiz G R; Scherer, Carolina B; Gonçalves, Lucio C

2017-01-01

Forage production is primarily limited by weather conditions under dryland production systems in Brazilian semi-arid regions, therefore sowing at the appropriate time is critical. The objectives of this study were to evaluate the CSM-CERES-Pearl Millet model from the DSSAT software suite for its ability to simulate growth, development, and forage accumulation of pearl millet [ Pennisetum glaucum (L.) R.] at three Brazilian semi-arid locations, and to use the model to study the impact of different sowing dates on pearl millet performance for forage. Four pearl millet cultivars were grown during the 2011 rainy season in field experiments conducted at three Brazilian semi-arid locations, under rainfed conditions. The genetic coefficients of the four pearl millet cultivars were calibrated for the model, and the model performance was evaluated with experimental data. The model was run for 14 sowing dates using long-term historical weather data from three locations, to determine the optimum sowing window. Results showed that performance of the model was satisfactory as indicated by accurate simulation of crop phenology and forage accumulation against measured data. The optimum sowing window varied among locations depending on rainfall patterns, although showing the same trend for cultivars within the site. The best sowing windows were from 15 April to 15 May for the Bom Conselho location; 12 April to 02 May for Nossa Senhora da Gloria; and 17 April to 25 May for Sao Bento do Una. The model can be used as a tool to evaluate the effect of sowing date on forage pearl millet performance in Brazilian semi-arid conditions.

Motivation and social contexts: a crossnational pilot study of achievement, power, and affiliation motives.

PubMed

Xu, Xiaoyan; Xu, Yangang; Mellor, David; Duan, Liqiong

2012-01-01

Previous research suggests that there is a relationship between social contexts (e.g., economic growth, engagement in wars) and motives within populations. In particular, high achievement motive is associated with subsequent economic growth, which in turn increases power motive. Increased national achievement and power motives have been argued to precede social changes that lead to decreased affiliation motives, and engagement in wars. The present study aimed to examine differences in achievement, power, and affiliation motives between 266 college students in China (a nation with sustained high economic growth) and 255 college students in the USA (a nation with previously strong but now slowing economic growth, and engaged in war). Analysis of personal strivings suggested that Chinese college students showed significantly higher levels of achievement motive than the American college students, but American college students showed significantly higher levels of affiliation motive than Chinese college students. Overall, males exhibited higher achievement motivation than females. No significant interaction effects were found for gender by location for any of the three motives. The findings are discussed in relation to previous research.

Preparation, cryopreservation, and growth of cells prepared from the green turtle (Chelonia mydas)

USGS Publications Warehouse

Moore, Melody K.; Work, Thierry M.; Balazs, George H.; Docherty, Douglas E.

1997-01-01

Techniques are described for preparing, preserving, and growing cell cultures from 30 to 40-day old green turtle embryos (2.0-3.0 cm length) including cells derived from skeletal muscle, liver, heart, kidney, eye, lung, and brain. Acceptable growth of all cells occurred in all standard cell culture media tested, with optimum growth temperature near 30??C. These cell cultures will be used in the study of sea turtle viral diseases including fibropapillomatosis, which is currently epidemic in some green turtle populations.

Site survey for optimum location of Optical Communication Experimental Facility

NASA Technical Reports Server (NTRS)

1968-01-01

Site survey was made to determine the optimum location for an Optical Communication Experimental Facility /OCEF/ and to recommend several sites, graded according to preference. A site was desired which could perform two-way laser communication with a spacecraft and laser tracking with a minimum of interruption by weather effects.

Monolithic, multi-bandgap, tandem, ultra-thin, strain-counterbalanced, photovoltaic energy converters with optimal subcell bandgaps

DOEpatents

Wanlass, Mark W [Golden, CO; Mascarenhas, Angelo [Lakewood, CO

2012-05-08

Modeling a monolithic, multi-bandgap, tandem, solar photovoltaic converter or thermophotovoltaic converter by constraining the bandgap value for the bottom subcell to no less than a particular value produces an optimum combination of subcell bandgaps that provide theoretical energy conversion efficiencies nearly as good as unconstrained maximum theoretical conversion efficiency models, but which are more conducive to actual fabrication to achieve such conversion efficiencies than unconstrained model optimum bandgap combinations. Achieving such constrained or unconstrained optimum bandgap combinations includes growth of a graded layer transition from larger lattice constant on the parent substrate to a smaller lattice constant to accommodate higher bandgap upper subcells and at least one graded layer that transitions back to a larger lattice constant to accommodate lower bandgap lower subcells and to counter-strain the epistructure to mitigate epistructure bowing.

Children’s visuospatial memory predicts mathematics achievement through early adolescence

PubMed Central

Li, Yaoran

2017-01-01

A previous study showed that gains in visuospatial memory from first to fifth grade predicted end-of-fifth grade mathematics but not reading achievement, controlling other factors. In this follow up study, these relations were assessed from sixth to ninth grade, inclusive (n = 145). The results showed that growth in visuospatial memory across the elementary school years was related to growth in mathematics achievement after fifth grade, controlling intelligence, the central executive and phonological memory components of working memory, in-class attentive behavior, parental education, and fifth grade mathematics achievement. As found for fifth grade, this relation was not found for reading achievement after fifth grade. In total, the results suggest that visuospatial memory has a unique influence on ease of learning some types of mathematics and that this influence becomes more important across successive grades. PMID:28192484

Optimum dietary arginine:lysine ratio for broiler chickens is altered during heat stress in association with changes in intestinal uptake and dietary sodium chloride.

PubMed

Brake, J; Balnave, D; Dibner, J J

1998-12-01

1. The effects of varying the dietary arginine:lysine (Arg:Lys) ratio for broiler chickens at thermoneutral and high temperatures was studied in a series of 5 experiments which measured intestinal epithelial transport or evaluated growth and food efficiency with practical diets or diets supplemented with L-arginine free base. 2. The growth studies showed that increasing the Arg:Lys ratio at high temperatures produced consistent improvements in food conversion without any loss in growth. 3. Increasing dietary sodium chloride concentration reduced the Arg:Lys ratio necessary for optimum food conversion. 4. Food conversion responses were improved whether L-arginine free base was used as a dietary supplement in place of an inert filler or practical diets with differing ingredients were used to vary the Arg:Lys ratio. 5. In the presence of an equimolar concentration of lysine the uptake of arginine by the intestinal epithelium of heat-stressed broilers was reduced significantly compared with that of broilers at thermoneutral temperatures. 6. The results indicate that the ideal amino acid balance for broilers varies with ambient temperature.

Achieving optimum sports performance during Ramadan: some practical recommendations.

PubMed

Maughan, Ronald J; Zerguini, Yacine; Chalabi, Hakim; Dvorak, Jiri

2012-01-01

Muslim athletes should fast from sunrise to sunset each day throughout the 30 days of Ramadan. Most athletes will continue to train throughout Ramadan, and they may also be required to compete at this time, but they will also engage in the religious, cultural, and social activities that Ramadan represents. The available evidence indicates that high-level athletes can maintain performance during Ramadan if physical training, food and fluid intake, and sleep are appropriate and well controlled. Individualized monitoring of athletes may help to prevent fatigue and overtraining and to reduce the risk of consequent illness and injury. The timing and intensity of training may require adjustment to optimize the training response, and training close to or after sunset may have advantages, but this will vary between individual and team sports and between environments that are predominantly Muslim and those that are predominantly non-Muslim. Training late in the day allows nutrition interventions after training to promote adaptations to the training stimulus, to promote recovery, and might help to reduce muscle damage. Sleep deficits have a number of adverse effects on well-being and performance, and athletes should ensure adequate sleep throughout Ramadan. In non-Muslim majority environments, especially in team sports, coaches and athletes should be sensitive to the needs of their team-mates who may be fasting. Event organizers should take account of the needs of Muslim athletes when scheduling the dates and timings of sports competitions.

Optimum concentric circular array antenna with high gain and side lobe reduction at 5.8 GHz

NASA Astrophysics Data System (ADS)

Zaid, Mohammed; Rafiqul Islam, Md; Habaebi, Mohamed H.; Zahirul Alam, AHM; Abdullah, Khaizuran

2017-11-01

The significance of high gain directional antennas stems from the need to cope up with the everyday progressing wireless communication systems. Due to low gain of the widely used microstrip antenna, combining multiple antennas in proper geometry increases the gain with good directive property. Over other array forms, this paper uses concentric circular array configuration for its compact structure and inherent symmetry in azimuth. This proposed array is composed of 9 elements on FR-4 substrate, which is designed for WLAN applications at 5.8GHz. Antenna Magus software is used for synthesis, while CST software is used for optimization. The proposed array is designed with optimum inter-element spacing and number of elements achieving a high directional gain of 15.7 dB compared to 14.2 dB of available literature, with a high reduction in side lobe level of -17.6 dB.

The effect of plant growth-promoting rhizobacteria on asparagus seedlings and germinating seeds subjected to water stress under greenhouse conditions.

PubMed

Liddycoat, Scott M; Greenberg, Bruce M; Wolyn, David J

2009-04-01

Plant growth-promoting rhizobacteria (PGPR) can have positive effects on vigour and productivity, especially under stress conditions. In asparagus (Asparagus officinalis L.) field culture, seeds are planted in high-density nurseries, and 1-year-old crowns are transplanted to production fields. Performance can be negatively affected by water stress, transplant shock, and disease pressure on wounded roots. PGPR inoculation has the potential to alleviate some of the stresses incurred in the production system. In this study, the effects of PGPR (Pseudomonas spp.) treatment were determined on 3-week-old greenhouse-grown seedlings and germinating seeds of 2 asparagus cultivars. The pots were irrigated to a predetermined level that resulted in optimum growth or the plants were subjected to drought or flooding stress for 8 weeks. The cultivars responded differently to PGPR: single inoculations of seedlings enhanced growth of 'Guelph Millennium' under optimum conditions and 'Jersey Giant' seedlings under drought stress. Seed inoculations with PGPR resulted in a positive response only for 'Guelph Millennium', for which both single or multiple inoculations enhanced plant growth under drought stress.

N-face GaN nanorods: Continuous-flux MOVPE growth and morphological properties

NASA Astrophysics Data System (ADS)

Bergbauer, W.; Strassburg, M.; Kölper, Ch.; Linder, N.; Roder, C.; Lähnemann, J.; Trampert, A.; Fündling, S.; Li, S. F.; Wehmann, H.-H.; Waag, A.

2011-01-01

We demonstrate the morphological properties of height, diameter and shape controlled N-face GaN nanorods (NRs) by adjusting conventional growth parameters of a standard metalorganic vapour phase epitaxy (MOVPE) growth process. Particularly the hydrogen fraction within the carrier gas was shown to be an important shaping tool for the grown nanostructures. Additionally, the aspect ratio of the NRs was successfully tuned by increasing the pitch of the nanoimprint lithography (NIL) pattern, while maintaining the hole-diameter constant. An optimum aspect ratio could be found at pitches between 400 and 800 nm, whereas larger pitches are counter-productive. The major conclusion drawn from our experiments is that the whole amount of growth material available over the masked surface contributes to the growth of the NRs.

Generate an Optimum Lightweight Legs Structure Design Based on Critical Posture in A-FLoW Humanoid Robot

NASA Astrophysics Data System (ADS)

Luthfi, A.; Subhan, K. A.; Eko H, B.; Sanggar, D. R.; Pramadihanto, D.

2018-04-01

Lightweight construction and energy efficiency play an important role in humanoid robot development. The application of computer-aided engineering (CAE) in the development process is one of the possibilities to achieve the appropriate reduction of the weight. This paper describes a method to generate an optimum lightweight legs structure design based on critical posture during walking locomotion in A-FLoW Humanoid robot.The criticalposture can be obtained from the highest forces and moments in each joint of the robot body during walking locomotion. From the finite element analysis (FEA) result can be realized leg structure design of A-FLoW humanoid robot with a maximum displacement value of 0.05 mmand weight reduction about 0.598 Kg from the thigh structure and a maximum displacement value of 0,13 mmand weight reduction about 0.57 kg from the shin structure.

Effect of water activity and pH on growth and toxin production by Clostridium botulinum type G.

PubMed Central

Briozzo, J; de Lagarde, E A; Chirife, J; Parada, J L

1986-01-01

The combined effect of water activity (aw) and pH on growth and toxin production by Clostridium botulinum type G strain 89 was investigated. The minimum aw at which growth and toxin formation occurred was 0.965, for media in which the pH was adjusted with either sodium chloride or sucrose. The minimum pH (at the optimum aw) for growth and toxin production of C. botulinum type G was found to be 5.6. Optimum conditions for toxin activation were a trypsin concentration of 0.1%, a pH of the medium of 6.5, and an incubation for 45 min at 37 degrees C. These data did not show evidence of heat-labile spores, since a heat shock of 75 degrees C for 10 min did not significantly decrease the spore count of strain 89G in media at pH 7.0 or 5.6. It was frequently observed that cells grown at reduced aw or pH experienced severe morphological changes. PMID:3518631

The combined theoretical and experimental approach to arrive at optimum parameters in friction stir welding

NASA Astrophysics Data System (ADS)

Jagadeesha, C. B.

2017-12-01

Even though friction stir welding was invented long back (1991) by TWI England, till now there has no method or procedure or approach developed, which helps to obtain quickly optimum or exact parameters yielding good or sound weld. An approach has developed in which an equation has been derived, by which approximate rpm can be obtained and by setting range of rpm ±100 or 50 rpm over approximate rpm and by setting welding speed equal to 60 mm/min or 50 mm/min one can conduct FSW experiment to reach optimum parameters; one can reach quickly to optimum parameters, i.e. desired rpm, and welding speed, which yield sound weld by the approach. This approach can be effectively used to obtain sound welds for all similar and dissimilar combinations of materials such as Steel, Al, Mg, Ti, etc.

Determination of Optimum Operation Parameters for Low-Intensity Pulsed Ultrasound and Low-Level Laser Based Treatment to Induce Proliferation of Osteoblast and Fibroblast Cells.

PubMed

Coskun, Mehmet Emre; Coskun, Kubra Acikalin; Tutar, Yusuf

2018-05-01

The aim of this study was to determine the optimum operating parameters (pulse duration, energy levels, and application time) to promote induction of osteoblast and fibroblast cell proliferation and to maintain cell viability treated with low-intensity pulsed ultrasound (LIPUS) and low-level laser therapy (LLLT). The positive effects of LIPUS and LLLT on cellular activity have been reported in recent years. Comparisons between experimental parameters of previous studies are difficult because scientific studies reported frequencies and the duty cycles of LIPUS and wavelengths and doses of LLLT in a wide range of parameters. However, optimum amount of energy and optimum time exposure must be determined to induce bone and tissue cell proliferation for effective healing process and to avoid cell damage. Fibroblast and osteoblast cell cultures were irradiated with LIPUS (10-50% pulse and continuous mode at 1 and 3 MHz for 1, 3, and 5 min) and LLLT (4, 8, and 16 J at 50, 100, 200, 300, 400, and 500 mW). Cell cultures were analyzed using XTT assay. For both cell types, LIPUS treatment with 10% pulse (1:9 duty cycle), 3 MHz, and for 1 min and LLLT treatment over 100 mV for 4, 8, and 16 J modalities contributed to the growth, and may help bone repair and tissue healing process optimally. Bio-stimulating effects of LLLT irradiation promote proliferation and maintain cell viability better than LIPUS treatment without causing thermal response for both cell types, and the therapeutic modality above 200 mV has maximum effectiveness.

The Population of Small Comets: Optimum Techniques for Detection

NASA Technical Reports Server (NTRS)

Schleicher, D.; AHearn, M.; Stewart, I. A. F.; Randall, C.; Brandt, J.

1999-01-01

The goals of this project were: (1) to present evidence to the scientific community for the importance of the small comet population and (2) to develop techniques for optimum detection in order to characterize the population. The work has been carried out by D. Schleicher (Lowell Observatory), M. A'Hearn and Y. Fernandez (University of Maryland), I.A.F. Stewart, C. Randall, and J. Brandt (University of Colorado).

The Chilling Optimum of Idaho and Arizona Ponderosa Pine Buds

Treesearch

David L. Wenny; Daniel J. Swanson; R. Kasten Dumroese

2002-01-01

Ponderosa pine (Pinus ponderosa) seedlings from Idaho (var. ponderosa) and Arizona (var. scopulorum) grown in a container nursery received optimum chilling [2,010 hr (84 days) of temperatures below 5°C]. While seedlings were in the greenhouse, days required for 50% of the population to break bud were similar for both seed sources...

Evolution of grain boundary character distributions in alloy 825 tubes during high temperature annealing: Is grain boundary engineering achieved through recrystallization or grain growth?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bai, Qin; Zhao, Qing

Grain boundary engineering (GBE) of nickel-based alloy 825 tubes was carried out with different cold drawing deformations by using a draw-bench on a factory production line and subsequent annealing at various temperatures. The microstructure evolution of alloy 825 during thermal-mechanical processing (TMP) was characterized by means of the electron backscatter diffraction (EBSD) technique to study the TMP effects on the grain boundary network and the evolution of grain boundary character distributions during high temperature annealing. The results showed that the proportion of ∑ 3{sup n} coincidence site lattice (CSL) boundaries of alloy 825 tubes could be increased to > 75%more » by the TMP of 5% cold drawing and subsequent annealing at 1050 °C for 10 min. The microstructures of the partially recrystallized samples and the fully recrystallized samples suggested that the proportion of low ∑ CSL grain boundaries depended on the annealing time. The frequency of low ∑ CSL grain boundaries increases rapidly with increasing annealing time associating with the formation of large-size highly-twinned grains-cluster microstructure during recrystallization. However, upon further increasing annealing time, the frequency of low ∑ CSL grain boundaries decreased markedly during grain growth. So it is concluded that grain boundary engineering is achieved through recrystallization rather than grain growth. - Highlights: •The grain boundary engineering (GBE) is applicable to 825 tubes. •GBE is achieved through recrystallization rather than grain growth. •The low ∑ CSL grain boundaries in 825 tubes can be increased to > 75%.« less

Comparison of Efficacy and Tolerance of Automatic Continuous Positive Airway Pressure Devices With the Optimum Continuous Positive Airway Pressure.

PubMed

Tommi, George; Aronow, Wilbert S; Sheehan, John C; McCleay, Matthew T; Meyers, Patrick G

Patients diagnosed with obstructive sleep apnea syndrome were randomly placed on automatic continuous positive airway pressure (ACPAP) for 2 hours followed by manual titration for the rest of the night. One hundred sixty-one patients entered the study, with at least 50 patients titrated with each of 3 ACPAP devices. The optimum continuous positive airway pressure (CPAP) was defined as the lowest pressure with an apnea-hypoxia index of ≤5/hr, which ranged from 4 cm to 18 cm. Success with ACPAP was approximately 60%-80% when the optimum CPAP was 4-6 cm but fell to below 30% if the optimum CPAP was ≥8 cm (P = 0.001). Average ACPAP ranged from 2 to 10 cm below the optimum level if the optimum CPAP was ≥8 cm. Patients who responded to a low CPAP but deteriorated on higher pressures failed to respond to any of the automatic devices. We recommend that CPAP titration be performed manually before initiation of ACPAP in patients with obstructive sleep apnea. The basal pressure for ACPAP should be the optimum pressure obtained by manual titration. Limits on the upper level of ACPAP may be necessary for patients who deteriorate on higher positive pressures.

Determination of optimum oven cooking procedures for lean beef products.

PubMed

Rodas-González, Argenis; Larsen, Ivy L; Uttaro, Bethany; Juárez, Manuel; Parslow, Joyce; Aalhus, Jennifer L

2015-11-01

In order to determine optimum oven cooking procedures for lean beef, the effects of searing at 232 or 260°C for 0, 10, 20 or 30 min, and roasting at 160 or 135°C on semimembranosus (SM) and longissimus lumborum (LL) muscles were evaluated. In addition, the optimum determined cooking method (oven-seared for 10 min at 232°C and roasted at 135°C) was applied to SM roasts varying in weight from 0.5 to 2.5 kg. Mainly, SM muscles seared for 0 or 10 min at 232°C followed by roast at 135°C had lower cooking loss, higher external browning color, more uniform internal color, and were more tender and flavorful (P < 0.05). Roast weights ≥1 kg had lesser cooking loss, more uniform internal color and tender compared to 0.5 kg (P < 0.05). Consequently, roasting at low temperature without searing is the recommended oven cooking procedure; with best response from muscle roast weight ≥1 kg.

Complete remission of liver metastasis in a lung cancer patient with epidermal growth factor mutation achieved with Icotinib.

PubMed

Zhu, Zhouyu; Chai, Ying

2016-11-01

A 65-year-old Chinese male was referred to our hospital for epidermal growth factor receptor (EGFR)-mutated advanced non-small cell lung cancer (NSCLC). Aggressive combined therapy with surgical resection of the right upper lung lesion and chemotherapy was performed. One month later, continued Icotinib treatment was used as magnetic resonance imaging revealed liver metastasis (LM). Interestingly, complete remission of the patient's LM lesions was achieved in six months. To our knowledge, this is the first report documenting a successful case of an NSCLC patient with LM treated with Icotinib after receiving a radical resection for pulmonary carcinoma. Our experience could provide a treatment strategy for patients with similar disease. © 2016 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

Optimum Onager: The Classical Mechanics of a Classical Siege Engine

ERIC Educational Resources Information Center

Denny, Mark

2009-01-01

The onager is a throwing weapon of classical antiquity, familiar to both the ancient Greeks and Romans. Here we analyze the dynamics of onager operation and derive the optimum angle for launching a projectile to its maximum range. There is plenty of scope for further considerations about increasing onager range, and so by thinking about how this…

Carbon sequestration, optimum forest rotation and their environmental impact

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kula, Erhun, E-mail: erhun.kula@bahcesehir.edu.tr; Gunalay, Yavuz, E-mail: yavuz.gunalay@bahcesehir.edu.tr

2012-11-15

Due to their large biomass forests assume an important role in the global carbon cycle by moderating the greenhouse effect of atmospheric pollution. The Kyoto Protocol recognises this contribution by allocating carbon credits to countries which are able to create new forest areas. Sequestrated carbon provides an environmental benefit thus must be taken into account in cost-benefit analysis of afforestation projects. Furthermore, like timber output carbon credits are now tradable assets in the carbon exchange. By using British data, this paper looks at the issue of identifying optimum felling age by considering carbon sequestration benefits simultaneously with timber yields. Themore » results of this analysis show that the inclusion of carbon benefits prolongs the optimum cutting age by requiring trees to stand longer in order to soak up more CO{sub 2}. Consequently this finding must be considered in any carbon accounting calculations. - Highlights: Black-Right-Pointing-Pointer Carbon sequestration in forestry is an environmental benefit. Black-Right-Pointing-Pointer It moderates the problem of global warming. Black-Right-Pointing-Pointer It prolongs the gestation period in harvesting. Black-Right-Pointing-Pointer This paper uses British data in less favoured districts for growing Sitka spruce species.« less

Growth hormone transgenesis in coho salmon disrupts muscle immune function impacting cross-talk with growth systems.

PubMed

Alzaid, Abdullah; Kim, Jin-Hyoung; Devlin, Robert H; Martin, Samuel A M; Macqueen, Daniel J

2018-04-26

Suppression of growth during infection may aid resource allocation towards effective immune function. Past work supporting this hypothesis in salmonid fish revealed an immune-responsive regulation of the insulin-like growth factor (IGF) system, an endocrine pathway downstream of growth hormone (GH). Skeletal muscle is the main target for growth and energetic storage in fish, yet little is known about how its growth is regulated during an immune response. We addressed this knowledge gap by characterizing muscle immune responses in size-matched coho salmon ( Oncorhynchus kisutch ) achieving different growth rates. We compared a wild-type strain with two GH transgenic groups from the same genetic background achieving either maximal or suppressed growth, a design separating GH's direct effects from its influence on growth rate and nutritional state. Fish were sampled 30h post-injection with PBS (control) or mimics of bacterial or viral infection. We quantified mRNA expression levels for genes from the GH, GH receptor, IGF hormone, IGF1 receptor and IGF-binding protein families, along with immune genes involved in inflammatory or antiviral responses and muscle growth status marker genes. We demonstrate dampened immune function in GH transgenics compared to wild-type. The muscle of GH transgenics achieving rapid growth showed no detectable antiviral response, coupled with evidence of a constitutive inflammatory state. GH and IGF system gene expression was strongly altered by GH transgenesis and fast growth, both for baseline expression and responses to immune stimulation. Thus, GH transgenesis strongly disrupts muscle immune status and normal GH and IGF system expression responses to immune stimulation. © 2018. Published by The Company of Biologists Ltd.

Cyclic stretching of soft substrates induces spreading and growth

PubMed Central

Cui, Yidan; Hameed, Feroz M.; Yang, Bo; Lee, Kyunghee; Pan, Catherine Qiurong; Park, Sungsu; Sheetz, Michael

2015-01-01

In the body, soft tissues often undergo cycles of stretching and relaxation that may affect cell behaviour without changing matrix rigidity. To determine whether transient forces can substitute for a rigid matrix, we stretched soft pillar arrays. Surprisingly, 1–5% cyclic stretching over a frequency range of 0.01–10 Hz caused spreading and stress fibre formation (optimum 0.1 Hz) that persisted after 4 h of stretching. Similarly, stretching increased cell growth rates on soft pillars comparative to rigid substrates. Of possible factors linked to fibroblast growth, MRTF-A (myocardin-related transcription factor-A) moved to the nucleus in 2 h of cyclic stretching and reversed on cessation; but YAP (Yes-associated protein) moved much later. Knockdown of either MRTF-A or YAP blocked stretch-dependent growth. Thus, we suggest that the repeated pulling from a soft matrix can substitute for a stiff matrix in stimulating spreading, stress fibre formation and growth. PMID:25704457

Application of a computer model to predict optimum slaughter end points for different biological types of feeder cattle.

PubMed

Williams, C B; Bennett, G L

1995-10-01

A bioeconomic model was developed to predict slaughter end points of different genotypes of feeder cattle, where profit/rotation and profit/day were maximized. Growth, feed intake, and carcass weight and composition were simulated for 17 biological types of steers. Distribution of carcass weight and proportion in four USDA quality and five USDA yield grades were obtained from predicted carcass weights and composition. Average carcass value for each genotype was calculated from these distributions under four carcass pricing systems that varied from value determined on quality grade alone to value determined on yield grade alone. Under profitable market conditions, rotation length was shorter and carcass weights lighter when the producer's goal was maximum profit/day, compared with maximum profit/rotation. A carcass value system based on yield grade alone resulted in greater profit/rotation and in lighter and leaner carcasses than a system based on quality grade alone. High correlations ( > .97) were obtained between breed profits obtained with different sets of input/output prices and carcass price discount weight ranges. This suggests that breed rankings on the basis of breed profits may not be sensitive to changes in input/output market prices. Steers that were on a grower-stocker system had leaner carcasses, heavier optimum carcass weight, greater profits, and less variation in optimum carcass weights between genotypes than steers that were started on a high-energy finishing diet at weaning. Overall results suggest that breed choices may change with different carcass grading and value systems and postweaning production systems. This model has potential to provide decision support in marketing fed cattle.

Analysis of the Optimum Gain of a High-Pass L-Matching Network for Rectennas

PubMed Central

Jordana, Josep; Robert, Francesc-Josep; Berenguer, Jordi

2017-01-01

Rectennas, which mainly consist of an antenna, matching network, and rectifier, are used to harvest radiofrequency energy in order to power tiny sensor nodes, e.g., the nodes of the Internet of Things. This paper demonstrates for the first time, the existence of an optimum voltage gain for high-pass L-matching networks used in rectennas by deriving an analytical expression. The optimum gain is that which leads to maximum power efficiency of the rectenna. Here, apart from the L-matching network, a Schottky single-diode rectifier was used for the rectenna, which was optimized at 868 MHz for a power range from −30 dBm to −10 dBm. As the theoretical expression depends on parameters not very well-known a priori, an accurate search of the optimum gain for each power level was performed via simulations. Experimental results show remarkable power efficiencies ranging from 16% at −30 dBm to 55% at −10 dBm, which are for almost all the tested power levels the highest published in the literature for similar designs. PMID:28757592

Analysis of the Optimum Gain of a High-Pass L-Matching Network for Rectennas.

PubMed

Gasulla, Manel; Jordana, Josep; Robert, Francesc-Josep; Berenguer, Jordi

2017-07-25

Rectennas, which mainly consist of an antenna, matching network, and rectifier, are used to harvest radiofrequency energy in order to power tiny sensor nodes, e.g., the nodes of the Internet of Things. This paper demonstrates for the first time, the existence of an optimum voltage gain for high-pass L-matching networks used in rectennas by deriving an analytical expression. The optimum gain is that which leads to maximum power efficiency of the rectenna. Here, apart from the L-matching network, a Schottky single-diode rectifier was used for the rectenna, which was optimized at 868 MHz for a power range from -30 dBm to -10 dBm. As the theoretical expression depends on parameters not very well-known a priori, an accurate search of the optimum gain for each power level was performed via simulations. Experimental results show remarkable power efficiencies ranging from 16% at -30 dBm to 55% at -10 dBm, which are for almost all the tested power levels the highest published in the literature for similar designs.

Optimum sensitivity derivatives of objective functions in nonlinear programming

NASA Technical Reports Server (NTRS)

Barthelemy, J.-F. M.; Sobieszczanski-Sobieski, J.

1983-01-01

The feasibility of eliminating second derivatives from the input of optimum sensitivity analyses of optimization problems is demonstrated. This elimination restricts the sensitivity analysis to the first-order sensitivity derivatives of the objective function. It is also shown that when a complete first-order sensitivity analysis is performed, second-order sensitivity derivatives of the objective function are available at little additional cost. An expression is derived whose application to linear programming is presented.

The Effects of a Growth Mindset Intervention on the Beliefs about Intelligence, Effort Beliefs, Achievement Goal Orientations, and Academic Self-Efficacy of LD Students with Reading Difficulties

ERIC Educational Resources Information Center

Baldridge, Mary Caufield

2010-01-01

The overall purpose of this study was to examine the effects of a "growth mindset" intervention on the beliefs about intelligence, effort beliefs, achievement goals, and academic self-efficacy of learning disabled (LD) students with reading difficulties. The treatment group consisted of 12 high school LD students with reading difficulties. This…

The determination of optimum condition in water hyacinth drying process by mixed adsorption drying method and modified fly ash as an adsorbent

NASA Astrophysics Data System (ADS)

Saputra, Asep Handaya; Putri, Rizky Anggreini

2017-05-01

Water hyacinth is an aquatic weed that has a very fast growth which makes it becomes a problem to the ecosystem. On the other hand, water hyacinth has a high fiber content (up to 20% by weight) which makes it potential to become raw material for composites and textile industries. As an aquatic plant, water hyacinth has a high initial moisture content that reaches more than 90%. Meanwhile the moisture content of fiber as a raw material for composite and textile industry should not be more than 10% to maintain the good quality of the products. Mixed adsorption drying method is one of the innovative method that can replace conventional drying process. Fluidization method which has been commonly used in agricultural and pharmaceutical products drying, can be enhanced by combining it with the adsorption method as performed in this study. In mixed fluidization-adsorption drying method, fly ash as adsorbent and water hyacinth fiber were put together into the fluidization column where the drying air evaporate the moisture content in water hyacinth fiber. In addition, the adsorbent adsorb the moisture content in the drying air to make the moisture content of the drying air remain low. The drying process is performed in various temperature and composition of water hyacinth and adsorbent in order to obtain the optimum drying condition. In addition, the effect of fly ash pellet and fly ash powder to the drying process was also performed. The result shows that the higher temperature and the more amount of adsorbent results in the faster drying rate. Fly ash pellet shows a better adsorption since it has a smaller pore diameter and wider surface area. The optimum temperature obtained from this study is 60°C and the optimum ratio of water hyacinth and fly ash is 50:50.

Hispanic students' mathematics achievement in the context of their high school types as STEM and non-STEM schools

NASA Astrophysics Data System (ADS)

Bicer, Ali; Capraro, Robert M.; Capraro, Mary M.

2018-07-01

The purpose of this paper is to demonstrate Hispanic students' mathematics achievement growth rate in Inclusive science, technology, engineering, and mathematics (STEM) high schools compared to Hispanic students' mathematics achievement growth rate in traditional public schools. Twenty-eight schools, 14 of which were Texas STEM (T-STEM) academies and 14 of which were matched non-STEM schools, were included in this study. A hierarchical linear modelling method was conducted. The result of the present study revealed that there was no difference in Hispanic students' mathematics achievement growth rate in T-STEM academies compared to Hispanic students' mathematics achievement growth rate in comparison schools. However, in terms of gender, the results indicated that female Hispanic students in T-STEM academies outperformed female Hispanic students in comparison schools in their mathematics growth rate.

Simulated Optimum Sowing Date for Forage Pearl Millet Cultivars in Multilocation Trials in Brazilian Semi-Arid Region

PubMed Central

Santos, Rafael D.; Boote, Kenneth J.; Sollenberger, Lynn E.; Neves, Andre L. A.; Pereira, Luiz G. R.; Scherer, Carolina B.; Gonçalves, Lucio C.

2017-01-01

Forage production is primarily limited by weather conditions under dryland production systems in Brazilian semi-arid regions, therefore sowing at the appropriate time is critical. The objectives of this study were to evaluate the CSM-CERES-Pearl Millet model from the DSSAT software suite for its ability to simulate growth, development, and forage accumulation of pearl millet [Pennisetum glaucum (L.) R.] at three Brazilian semi-arid locations, and to use the model to study the impact of different sowing dates on pearl millet performance for forage. Four pearl millet cultivars were grown during the 2011 rainy season in field experiments conducted at three Brazilian semi-arid locations, under rainfed conditions. The genetic coefficients of the four pearl millet cultivars were calibrated for the model, and the model performance was evaluated with experimental data. The model was run for 14 sowing dates using long-term historical weather data from three locations, to determine the optimum sowing window. Results showed that performance of the model was satisfactory as indicated by accurate simulation of crop phenology and forage accumulation against measured data. The optimum sowing window varied among locations depending on rainfall patterns, although showing the same trend for cultivars within the site. The best sowing windows were from 15 April to 15 May for the Bom Conselho location; 12 April to 02 May for Nossa Senhora da Gloria; and 17 April to 25 May for Sao Bento do Una. The model can be used as a tool to evaluate the effect of sowing date on forage pearl millet performance in Brazilian semi-arid conditions. PMID:29276521

Microwave-assisted Facile and Ultrafast Growth of ZnO Nanostructures and Proposition of Alternative Microwave-assisted Methods to Address Growth Stoppage

NASA Astrophysics Data System (ADS)

Rana, Abu Ul Hassan Sarwar; Kang, Mingi; Kim, Hyun-Seok

2016-04-01

The time constraint in the growth of ZnO nanostructures when using a hydrothermal method is of paramount importance in contemporary research, where a long fabrication time rots the very essence of the research on ZnO nanostructures. In this study, we present the facile and ultrafast growth of ZnO nanostructures in a domestic microwave oven within a pressurized environment in just a few minutes. This method is preferred for the conventional solution-based method because of the ultrafast supersaturation of zinc salts and the fabrication of high-quality nanostructures. The study of the effect of seed layer density, growth time, and the solution’s molar concentration on the morphology, alignment, density, and aspect ratio of ZnO nanorods (ZNRs) is explored. It is found in a microwave-assisted direct growth method that ~5 mins is the optimum time beyond which homogeneous nucleation supersedes heterogeneous nucleation, which results in the growth stoppage of ZNRs. To deal with this issue, we propound different methods such as microwave-assisted solution-replacement, preheating, and PEI-based growth methods, where growth stoppage is addressed and ZNRs with a high aspect ratio can be grown. Furthermore, high-quality ZnO nanoflowers and ZnO nanowalls are fabricated via ammonium hydroxide treatment in a very short time.

Determination of the optimum concentration cellulose baggase in making film bioplastic

NASA Astrophysics Data System (ADS)

Chadijah, S.; Rustiah, W. O.; Munir, M. I. D.

2018-03-01

The hoarding rubbish synthetic plastic caused pollution and demage in life circles, to cope it can be done with synthesizing the plastic from agriculture substance or called biopolymer (bioplastic). It was that potentially as bioplastic was biopolymer from agriculture substance baggase that contain cellulose 40 %. This research aimed to determine the optimum concentration cellulose baggase in making bioplastic film with adding chitosan and sorbitol plasticizer and also to know the result of characterization film bioplastic. The steps in this research were; the extraction of cellulose, making film bioplastic, tensile strenght test and used characterization spectrofotometer FTIR. In this research showed that optimum concentration cellulose baggase in making film bioplastic was 2% with adding chitosan and sorbitol plasticizer. The optimal result of tensile strenght test was 0,089 Kgf/cm2 with elongation percent 15,90 %. The analyzing FTIR in all of variation that looked almost same with characterization with tapes -OH, -NH and C-O.

Optimum wall impedance for spinning modes: A correlation with mode cut-off ratio

NASA Technical Reports Server (NTRS)

Rice, E. J.

1978-01-01

A correlating equation relating the optimum acoustic impedance for the wall lining of a circular duct to the acoustic mode cut-off ratio, is presented. The optimum impedance was correlated with cut-off ratio because the cut-off ratio appears to be the fundamental parameter governing the propagation of sound in the duct. Modes with similar cut-off ratios respond in a similar way to the acoustic liner. The correlation is a semi-empirical expression developed from an empirical modification of an equation originally derived from sound propagation theory in a thin boundary layer. This correlating equation represents a part of a simplified liner design method, based upon modal cut-off ratio, for multimodal noise propagation.

Performance of optimum detector structures for noisy intersymbol interference channels

NASA Technical Reports Server (NTRS)

Womer, J. D.; Fritchman, B. D.; Kanal, L. N.

1971-01-01

The errors which arise in transmitting digital information by radio or wireline systems because of additive noise from successively transmitted signals interfering with one another are described. The probability of error and the performance of optimum detector structures are examined. A comparative study of the performance of certain detector structures and approximations to them, and the performance of a transversal equalizer are included.

Optimum electric utility spot price determinations for small power producing facilities operating under PURPA provisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghoudjehbaklou, H.; Puttgen, H.B.

This paper outlines an optimum spot price determination procedure in the general context of the Public Utility Regulatory Policies Act, PURPA, provisions. PURPA stipulates that local utilities must offer to purchase all available excess electric energy from Qualifying Facilities, QF, at fair market prices. As a direct consequence of these PURPA regulations, a growing number of owners are installing power producing facilities and optimize their operational schedules to minimize their utility related costs or, in some cases, actually maximize their revenues from energy sales to the local utility. In turn, the utility strives to use spot prices which maximize itsmore » revenues from any given Small Power Producing Facility, SPPF, a schedule while respecting the general regulatory and contractual framework. the proposed optimum spot price determination procedure fully models the SPPF operation, it enforces the contractual and regulatory restrictions, and it ensures the uniqueness of the optimum SPPF schedule.« less

Optimum electric utility spot price determinations for small power producing facilities operating under PURPA provisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghoudjehbaklou, H.; Puttgen, H.B.

The present paper outlines an optimum spot price determination procedure in the general context of the Public Utility Regulatory Policies Act, PURPA, provisions. PURPA stipulates that local utilities must offer to purchase all available excess electric energy from Qualifying Facilities, QF, at fair market prices. As a direct consequence of these PURPA regulations, a growing number of owners are installing power producing facilities and optimize their operational schedules to minimize their utility related costs or, in some cases, actually maximize their revenues from energy sales to the local utility. In turn, the utility will strive to use spot prices whichmore » maximize its revenues from any given Small Power Producing Facility, SPPF, schedule while respecting the general regulatory and contractual framework. The proposed optimum spot price determination procedure fully models the SPPF operation, it enforces the contractual and regulatory restrictions, and it ensures the uniqueness of the optimum SPPF schedule.« less

A dye-decolorizing peroxidase from Bacillus subtilis exhibiting substrate-dependent optimum temperature for dyes and β-ether lignin dimer

PubMed Central

Min, Kyoungseon; Gong, Gyeongtaek; Woo, Han Min; Kim, Yunje; Um, Youngsoon

2015-01-01

In the biorefinery using lignocellulosic biomass as feedstock, pretreatment to breakdown or loosen lignin is important step and various approaches have been conducted. For biological pretreatment, we screened Bacillus subtilis KCTC2023 as a potential lignin-degrading bacterium based on veratryl alcohol (VA) oxidation test and the putative heme-containing dye-decolorizing peroxidase was found in the genome of B. subtilis KCTC2023. The peroxidase from B. subtilis KCTC2023 (BsDyP) was capable of oxidizing various substrates and atypically exhibits substrate-dependent optimum temperature: 30°C for dyes (Reactive Blue19 and Reactive Black5) and 50°C for high redox potential substrates (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid [ABTS], VA, and veratryl glycerol-β-guaiacyl ether [VGE]) over +1.0 V vs. normal hydrogen electrode. At 50°C, optimum temperature for high redox potential substrates, BsDyP not only showed the highest VA oxidation activity (0.13 Umg−1) among the previously reported bacterial peroxidases but also successfully achieved VGE decomposition by cleaving Cα-Cβ bond in the absence of any oxidative mediator with a specific activity of 0.086 Umg−1 and a conversion rate of 53.5%. Based on our results, BsDyP was identified as the first bacterial peroxidase capable of oxidizing high redox potential lignin-related model compounds, especially VGE, revealing a previously unknown versatility of lignin degrading biocatalyst in nature. PMID:25650125

Optimum outlier model for potential improvement of environmental cleaning and disinfection.

PubMed

Rupp, Mark E; Huerta, Tomas; Cavalieri, R J; Lyden, Elizabeth; Van Schooneveld, Trevor; Carling, Philip; Smith, Philip W

2014-06-01

The effectiveness and efficiency of 17 housekeepers in terminal cleaning 292 hospital rooms was evaluated through adenosine triphosphate detection. A subgroup of housekeepers was identified who were significantly more effective and efficient than their coworkers. These optimum outliers may be used in performance improvement to optimize environmental cleaning.

Development and application of optimum sensitivity analysis of structures

NASA Technical Reports Server (NTRS)

Barthelemy, J. F. M.; Hallauer, W. L., Jr.

1984-01-01

The research focused on developing an algorithm applying optimum sensitivity analysis for multilevel optimization. The research efforts have been devoted to assisting NASA Langley's Interdisciplinary Research Office (IRO) in the development of a mature methodology for a multilevel approach to the design of complex (large and multidisciplinary) engineering systems. An effort was undertaken to identify promising multilevel optimization algorithms. In the current reporting period, the computer program generating baseline single level solutions was completed and tested out.

Enhanced solar photoelectrochemical conversion efficiency of the hydrothermally-deposited TiO2 nanorod arrays: Effects of the light trapping and optimum charge transfer

NASA Astrophysics Data System (ADS)

An, Gil Woo; Mahadik, Mahadeo A.; Chae, Weon-Sik; Kim, Hyun Gyu; Cho, Min; Jang, Jum Suk

2018-05-01

The vertically aligned TiO2 nanorod arrays (NRA) with manipulated aspect ratio were hydrothermally synthesized by changing the amount of the titanium (Ti) precursor in the initial growth solution. FE-SEM images show the optimum morphology, density and aspect ratio of the well-aligned TB-1.2 NRs on the surface of the FTO substrate. The UV-vis-absorption measurements revealed that a sample prepared at TB-1.2 can provide an increased light trapping effect. PEC analyses demonstrated that the TiO2 nanorods deposited at TB-1.2 of Titanium butoxide show a relatively high PEC conversion efficiency (3.5 times) compared with the TB-0.8 prepared TiO2 at a 1.0 V versus RHE. The higher PEC performance is believed to be the result of an enhancement of the optimum aspect ratio, light trapping, an efficient charge separation, and the high carrier transport in the vertically aligned TiO2 NRs. Further, the PEC based organic dye degradation experiments showed 77% and 94% removal of Orange II and methylene blue respectively. Additionally, 109 μmol h-1 cm-2 hydrogen generations were attributed using optimized vertically aligned TiO2 NRA's. Thus, the appropriate morphology manipulated the TiO2 NRAs are useful for solar conversion applications.

[New growth references of the World Health Organization based on breast fed infants].

PubMed

Lozano de la Torre, Maria J

2007-02-01

The World Health Organization Multicenter Growth Reference Study is a multinational project to develop new growth references for infants and young children. The design combines a longitudinal study from birth to 24 months with a cross-sectional study of children aged 18 to 71 months. The pooled sample from the six participating countries (Brazil, Ghana, India, Norway, Oman, and the United States) consists of 8440 children. The new WHO Child Growth Standards confirm that all children worldwide, given an optimum start in life, have the same potential for growth and prove that differences in children's growth to the age of 5 years are more influenced by nutrition, feeding practices, environment, and healthcare than by genetics or ethnicity. The new standards are based on the breast fed child as the norm for growth and development. For the first time, this ensures coherence among the tools used to assess growth and national and international infant feeding guidelines, which recommend breast feeding as the optimal source of nutrition during infancy.

Suppressing Nitrite-oxidizing Bacteria Growth to Achieve Nitrogen Removal from Domestic Wastewater via Anammox Using Intermittent Aeration with Low Dissolved Oxygen

PubMed Central

Ma, Bin; Bao, Peng; Wei, Yan; Zhu, Guibing; Yuan, Zhiguo; Peng, Yongzhen

2015-01-01

Achieving nitrogen removal from domestic wastewater using anaerobic ammonium oxidation (anammox) has the potential to make wastewater treatment energy-neutral or even energy-positive. The challenge is to suppress the growth of nitrite-oxidizing bacteria (NOB). This study presents a promising method based on intermittent aeration with low dissolved oxygen to limit NOB growth, thereby providing an advantage to anammox bacteria to form a partnership with the ammonium-oxidizing bacteria (AOB). The results showed that NOB was successfully suppressed using that method, with the relative abundance of NOB maintained between 2.0–2.6%, based on Fluorescent in-situ Hybridization. Nitrogen could be effectively removed from domestic wastewater with anammox at a temperature above 20 °C, with an effluent total nitrogen (TN) concentration of 6.6 ± 2.7 mg/L, while the influent TN and soluble chemical oxygen demand were 62.6 ± 3.1 mg/L and 88.0 ± 8.1 mg/L, respectively. PMID:26354321

Device and method for screening crystallization conditions in solution crystal growth

NASA Technical Reports Server (NTRS)

Carter, Daniel C. (Inventor)

1995-01-01

A device and method for detecting optimum protein crystallization conditions and for growing protein crystals in either 1g or microgravity environments comprising a housing, defining at least one pair of chambers for containing crystallization solutions is presented. The housing further defines an orifice therein for providing fluid communication between the chambers. The orifice is adapted to receive a tube which contains a gelling substance for limiting the rate of diffusive mixing of the crystallization solutions. The solutions are diffusively mixed over a period of time defined by the quantity of gelling substance sufficient to achieve equilibration and to substantially reduce density driven convection disturbances therein. The device further includes endcaps to seal the first and second chambers. One of the endcaps includes a dialysis chamber which contains protein solution in which protein crystals are grown. Once the endcaps are in place, the protein solution is exposed to the crystallization solutions wherein the solubility of the protein solution is reduced at a rate responsive to the rate of diffusive mixing of the crystallization solutions. This allows for a controlled approach to supersaturation and allows for screening of crystal growth conditions at preselected intervals.

Device and Method for Screening Crystallization Conditions in Solution Crystal Growth

NASA Technical Reports Server (NTRS)

Carter, Daniel C. (Inventor)

1997-01-01

A device and method for detecting optimum protein crystallization conditions and for growing protein crystals in either 1 g or microgravity environments comprising a housing defining at least one pair of chambers for containing crystallization solutions. The housing further defines an orifice therein for providing fluid communication between the chambers. The orifice is adapted to receive a tube which contains a gelling substance for limiting the rate of diffusive mixing of the crystallization solutions. The solutions are diffusively mixed over a period of time defined by the quantity of gelling substance sufficient to achieve equilibration and to substantially reduce density driven convection disturbances therein. The device further includes endcaps to seal the first and second chambers. One of the endcaps includes a dialysis chamber which contains protein solution in which protein crystals are grown. Once the endcaps are in place. the protein solution is exposed to the crystallization solutions wherein the solubility of the protein solution is reduced at a rate responsive to the rate of diffusive mixing of the crystallization solutions. This allows for a controlled approach to supersaturation and allows for screening of crystal growth conditions at preselected intervals.

State Growth Models for School Accountability: Progress on Development and Reporting Measures of Student Growth

ERIC Educational Resources Information Center

Blank, Rolf K.

2010-01-01

The Council of Chief State School Officers (CCSSO) is working to respond to increased interest in the use of growth models for school accountability. Growth models are based on tracking change in individual student achievement scores over multiple years. While growth models have been used for decades in academic research and program evaluation, a…

Optimum parallel step-sector bearing lubricated with an incompressible fluid

NASA Technical Reports Server (NTRS)

Hamrock, B. J.

1983-01-01

The dimensionless parameters normally associated with a step sector thrust bearing are the film thickness ratio, the dimensionless step location, the number of sectors, the radius ratio, and the angular extent of the lubrication feed groove. The optimum number of sectors and the parallel step configuration for a step sector thrust bearing while considering load capacity or stiffness and assuming an incompressible fluid are presented.

Optimum pelvic incidence minus lumbar lordosis value can be determined by individual pelvic incidence.

PubMed

Inami, Satoshi; Moridaira, Hiroshi; Takeuchi, Daisaku; Shiba, Yo; Nohara, Yutaka; Taneichi, Hiroshi

2016-11-01

Adult spinal deformity (ASD) classification showing that ideal pelvic incidence minus lumbar lordosis (PI-LL) value is within 10° has been received widely. But no study has focused on the optimum level of PI-LL value that reflects wide variety in PI among patients. This study was conducted to determine the optimum PI-LL value specific to an individual's PI in postoperative ASD patients. 48 postoperative ASD patients were recruited. Spino-pelvic parameters and Oswestry Disability Index (ODI) were measured at the final follow-up. Factors associated with good clinical results were determined by stepwise multiple regression model using the ODI. The patients with ODI under the 75th percentile cutoff were designated into the "good" health related quality of life (HRQOL) group. In this group, the relationship between the PI-LL and PI was assessed by regression analysis. Multiple regression analysis revealed PI-LL as significant parameters associated with ODI. Thirty-six patients with an ODI <22 points (75th percentile cutoff) were categorized into a good HRQOL group, and linear regression models demonstrated the following equation: PI-LL = 0.41PI-11.12 (r = 0.45, P = 0.0059). On the basis of this equation, in the patients with a PI = 50°, the PI-LL is 9°. Whereas in those with a PI = 30°, the optimum PI-LL is calculated to be as low as 1°. In those with a PI = 80°, PI-LL is estimated at 22°. Consequently, an optimum PI-LL is inconsistent in that it depends on the individual PI.

Optimum Temperature for Storage of Fruit and Vegetables with Reference to Chilling Injury

NASA Astrophysics Data System (ADS)

Murata, Takao

Cold storage is an important technique for preserving fresh fruit and vegetables. Deterioration due to ripening, senescence and microbiological disease can be retarded by storage at optimum temperature being slightly above the freezing point of tissues of fruit and vegetables. However, some fruit and vegetables having their origins in tropical or subtropical regions of the world are subject to chilling injury during transportation, storage and wholesale distribution at low temperature above freezing point, because they are usually sensitive to low temperature in the range of 15&digC to 0°C. This review will focus on the recent informations regarding chilling injury of fruit and vegetables, and summarize the optimum temperature for transportation and storage of fruit and vegetables in relation to chilling injury.

Growth in pediatric renal transplant recipients.

PubMed

Vasudevan, A; Phadke, K

2007-04-01

One of the fundamental challenges in managing pediatric renal transplant recipient is to ensure normal growth and development. The goal of renal transplant is not just to prolong life but to optimize quality of life. Short stature during childhood may be associated with academic underachievement and development of comorbidities such as attention deficit hyperactivity disorder, learning disability, and mood disorders. The most important factors affecting growth are use of corticosteroids, allograft function, and age and height deficit at the time of transplant. Aggressive conservative management of chronic renal failure and early use of growth hormone therapy will help in optimizing height at time of transplant. Early transplant, steroid minimization or withdrawal, and growth hormone therapy will help in achieving normal adult height in a majority of renal post transplant population. Steroid avoidance to achieve good growth still needs to be validated.

Student achievement in science: A longitudinal look at individual and school differences

NASA Astrophysics Data System (ADS)

Martinez, Alina

The importance of science in today's technological society necessitates continued attention to students' experiences in science and specifically their achievement in science. There is a need to look at gender and race/ethnicity simultaneously when studying students' experiences in science and to explore factors related to higher achievement among students. Using data from the Longitudinal Study of American Youth, this study contributes to existing literature on student achievement in science by simultaneously exploring the effects of race/ethnicity and gender. Capitalizing on the availability of yearly science achievement scores, I present trajectories of student achievement from 7th to 12th grade. This study also includes an exploration of school effects. Overall, student achievement in science increases from 7th to 12th grade, although some leveling is seen in later grades. Growth in achievement differs by both gender and race/ethnicity, but racial/ethnic differences are larger than gender differences. Hispanic, Black, Asian, and White males score higher, on average, throughout the secondary grades than their female counterparts. Achievement scores of Asian students are consistently higher than White students, who in turn score higher than Hispanic and finally Black students. Both background and science-related factors help explain variation in achievement status and growth in achievement. Parental education is positively associated with achievement status among all groups except Black students for whom there is no effect of parental education. Science related resources in the home are positively associated with student achievement and the effect of these resources increases in later grades. Student achievement in science is also positively related to student course taking and attitude toward science. Furthermore, both the negative effect of viewing science as a male domain, which exists for males and females, and the positive effect of parental support for

The Population of Small Comets: Optimum Techniques for Detection

NASA Technical Reports Server (NTRS)

Brandt, John C.

1997-01-01

The goals of this project were: (1) to present evidence to the scientific community for the importance of the small comet population and (2) to develop techniques for optimum detection in order to characterize the population. Our work on techniques has been to develop algorithms for searching images for SCs based on the distinctive properties of comets; (1) motion with respect to background stars; (2) extended source with most light coming from the coma rather than the nucleus; and characteristic spectral signature.

Achievement Motivation Development Project. Final Report. Appendix IV, Part 2.

ERIC Educational Resources Information Center

McClelland, David C.; Alschuler, Alfred S.

The Achievement Motivation Development Project is described. The Project has culminated in the development of course materials designed explicitly to promote aspects of psychological growth. As such, it is viewed as but one thrust in an emerging psychological education movement. Achievement motivation is defined as a way of planning, a set of…

Optimal conditions of mycelia growth of Laetiporus sulphureus sensu lato

PubMed Central

Luangharn, Thatsanee; Karunarathna, Samantha C.; Hyde, Kevin D.; Chukeatirote, Ekachai

2014-01-01

Laetiporus sulphureus is an edible wood-rotting basidiomycete, growing on decaying logs, stumps, and trunks of many deciduous and coniferous tree species. This fungus produces relatively large striking yellowish or orange-coloured bracket-like fruitbodies. L. sulphureus is widely consumed as a nutritional food because of its fragrance and texture. In this study, two L. sulphureus strains, MFLUCC 12-0546 and MFLUCC 12-0547, isolated from Chiang Rai, Thailand, were investigated for optimal conditions of mycelia growth. Potato dextrose agar and malt extract agar were observed as the favourable medium for mycelia growth. The optimum pH and temperature for the mushroom mycelia were 6–8 and 25–30°C, respectively. PMID:25544934

Optimum design using VICONOPT, a buckling and strength constraint program for prismatic assemblies of anisotropic plates

NASA Technical Reports Server (NTRS)

Butler, R.; Williams, F. W.

1992-01-01

A computer program for obtaining the optimum (least mass) dimensions of the kind of prismatic assemblies of laminated, composite plates which occur in advanced aerospace construction is described. Rigorous buckling analysis (derived from exact member theory) and a tailored design procedure are used to produce designs which satisfy buckling and material strength constraints and configurational requirements. Analysis is two to three orders of magnitude quicker than FEM, keeps track of all the governing modes of failure and is efficiently adapted to give sensitivities and to maintain feasibility. Tailoring encourages convergence in fewer sizing cycles than competing programs and permits start designs which are a long way from feasible and/or optimum. Comparisons with its predecessor, PASCO, show that the program is more likely to produce an optimum, will do so more quickly in some cases, and remains accurate for a wider range of problems.

Optimum surface roughness prediction for titanium alloy by adopting response surface methodology

NASA Astrophysics Data System (ADS)

Yang, Aimin; Han, Yang; Pan, Yuhang; Xing, Hongwei; Li, Jinze

Titanium alloy has been widely applied in industrial engineering products due to its advantages of great corrosion resistance and high specific strength. This paper investigated the processing parameters for finish turning of titanium alloy TC11. Firstly, a three-factor central composite design of experiment, considering the cutting speed, feed rate and depth of cut, are conducted in titanium alloy TC11 and the corresponding surface roughness are obtained. Then a mathematic model is constructed by the response surface methodology to fit the relationship between the process parameters and the surface roughness. The prediction accuracy was verified by the one-way ANOVA. Finally, the contour line of the surface roughness under different combination of process parameters are obtained and used for the optimum surface roughness prediction. Verification experimental results demonstrated that material removal rate (MRR) at the obtained optimum can be significantly improved without sacrificing the surface roughness.

[Calculating the optimum size of a hemodialysis unit based on infrastructure potential].

PubMed

Avila-Palomares, Paula; López-Cervantes, Malaquías; Durán-Arenas, Luis

2010-01-01

To estimate the optimum size for hemodialysis units to maximize production given capital constraints. A national study in Mexico was conducted in 2009. Three possible methods for estimating a units optimum size were analyzed: hemodialysis services production under monopolistic market, under a perfect competitive market and production maximization given capital constraints. The third method was considered best based on the assumptions made in this paper; an optimal size unit should have 16 dialyzers (15 active and one back up dialyzer) and a purifier system able to supply all. It also requires one nephrologist, five nurses per shift, considering four shifts per day. Empirical evidence shows serious inefficiencies in the operation of units throughout the country. Most units fail to maximize production due to not fully utilizing equipment and personnel, particularly their water purifier potential which happens to be the most expensive asset for these units.

Superparasitism, immune response and optimum progeny yield in the gregarious parasitoid Palmistichus elaeisis.

PubMed

de S Pereira, Kleber; Guedes, Nelsa Maria P; Serrão, José E; Zanuncio, José C; Guedes, Raul Narciso C

2017-06-01

The subsequent deposition of an egg clutch by a female parasitoid into a host already parasitised either by itself or a conspecific (i.e. superparasitism) is a counterintuitive adaptive strategy, particularly considering the female parasitoid's ability to recognise the parasitised hosts. Such a scenario suggests that the adaptive value of superparasitism depends on the number of clutches laid in the same host, with consequences for parasitoid progeny yield. Here, we tested whether such is the case for the gregarious parasitoid Palmistichus elaeisis and explored its underlying basis. Allowing female parasitoids to lay multiple egg clutches in a single melonworm host pupa, parasitoid progeny and fitness exhibited a peak or optimum at three egg clutches laid per host pupa. In addition, haemocyte count, encapsulation and melanisation decreased with the number of egg clutches laid per host pupa. An optimum number of three clutches laid per host pupa was detected for P. elaeisis. As immune response via haemocyte production, encapsulation and melanisation decreased with the number of clutches laid per host, the higher parasitoid yield and fitness observed is the likely consequence of a compromised immune response coupled with an accommodative (i.e. scramble) larval competitive strategy allowing enough resources for optimum balance of parasitoid number and quality produced. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Is always authoritative the optimum parenting style? Evidence from Spanish families.

PubMed

García, Fernando; Gracia, Enrique

2009-01-01

The aim of this paper is to establish which parenting style is associated with optimum youth outcomes among adolescents of Spanish families. A sample of 1,416 teenagers from 12 to 17 years of age, of whom 57.2% were females, reported on their parents' child-rearing practices. The teenagers' parents were classified into one of four groups (authoritative, authoritarian, indulgent, or neglectful). The adolescents were then contrasted on four different outcomes: (1) self-esteem (academic, social, emotional, family and physical); (2) psychosocial maladjustment (hostility/aggression, negative self-esteem, negative self-adequacy, emotional irresponsiveness, emotional instability, and negative worldview); (3) personal competence (social competence, grade point average, and number of failing grades); and (4) problem behaviors (school misconduct, delinquency, and drug use). Results showed that both the indulgent and authoritative parenting styles were associated with better outcomes than authoritarian and neglectful parenting. Overall, our results supported the idea that in Spain the optimum style of parenting is the indulgent one, as adolescents' scores in the four sets of youth outcomes were equal or better than the authoritative style of parenting.

Optimum design of bolted composite lap joints under mechanical and thermal loading

NASA Astrophysics Data System (ADS)

Kradinov, Vladimir Yurievich

A new approach is developed for the analysis and design of mechanically fastened composite lap joints under mechanical and thermal loading. Based on the combined complex potential and variational formulation, the solution method satisfies the equilibrium equations exactly while the boundary conditions are satisfied by minimizing the total potential. This approach is capable of modeling finite laminate planform dimensions, uniform and variable laminate thickness, laminate lay-up, interaction among bolts, bolt torque, bolt flexibility, bolt size, bolt-hole clearance and interference, insert dimensions and insert material properties. Comparing to the finite element analysis, the robustness of the method does not decrease when modeling the interaction of many bolts; also, the method is more suitable for parametric study and design optimization. The Genetic Algorithm (GA), a powerful optimization technique for multiple extrema functions in multiple dimensions search spaces, is applied in conjunction with the complex potential and variational formulation to achieve optimum designs of bolted composite lap joints. The objective of the optimization is to acquire such a design that ensures the highest strength of the joint. The fitness function for the GA optimization is based on the average stress failure criterion predicting net-section, shear-out, and bearing failure modes in bolted lap joints. The criterion accounts for the stress distribution in the thickness direction at the bolt location by applying an approach utilizing a beam on an elastic foundation formulation.

Are trait-growth models transferable? Predicting multi-species growth trajectories between ecosystems using plant functional traits

PubMed Central

Vesk, Peter A.

2017-01-01

Plant functional traits are increasingly used to generalize across species, however few examples exist of predictions from trait-based models being evaluated in new species or new places. Can we use functional traits to predict growth of unknown species in different areas? We used three independently collected datasets, each containing data on heights of individuals from non-resprouting species over a chronosquence of time-since-fire sites from three ecosystems in south-eastern Australia. We examined the influence of specific leaf area, woody density, seed size and leaf nitrogen content on three aspects of plant growth; maximum relative growth rate, age at maximum growth and asymptotic height. We tested our capacity to perform out-of-sample prediction of growth trajectories between ecosystems using species functional traits. We found strong trait-growth relationships in one of the datasets; whereby species with low SLA achieved the greatest asymptotic heights, species with high leaf-nitrogen content achieved relatively fast growth rates, and species with low seed mass reached their time of maximum growth early. However these same growth-trait relationships did not hold across the two other datasets, making accurate prediction from one dataset to another unachievable. We believe there is evidence to suggest that growth trajectories themselves may be fundamentally different between ecosystems and that trait-height-growth relationships may change over environmental gradients. PMID:28486535

Analysis and Experimental Investigation of Optimum Design of Thermoelectric Cooling/Heating System for Car Seat Climate Control (CSCC)

NASA Astrophysics Data System (ADS)

Elarusi, Abdulmunaem; Attar, Alaa; Lee, HoSung

2018-02-01

The optimum design of a thermoelectric system for application in car seat climate control has been modeled and its performance evaluated experimentally. The optimum design of the thermoelectric device combining two heat exchangers was obtained by using a newly developed optimization method based on the dimensional technique. Based on the analytical optimum design results, commercial thermoelectric cooler and heat sinks were selected to design and construct the climate control heat pump. This work focuses on testing the system performance in both cooling and heating modes to ensure accurate analytical modeling. Although the analytical performance was calculated using the simple ideal thermoelectric equations with effective thermoelectric material properties, it showed very good agreement with experiment for most operating conditions.

Optimum runway orientation relative to crosswinds

NASA Technical Reports Server (NTRS)

Falls, L. W.; Brown, S. C.

1972-01-01

Specific magnitudes of crosswinds may exist that could be constraints to the success of an aircraft mission such as the landing of the proposed space shuttle. A method is required to determine the orientation or azimuth of the proposed runway which will minimize the probability of certain critical crosswinds. Two procedures for obtaining the optimum runway orientation relative to minimizing a specified crosswind speed are described and illustrated with examples. The empirical procedure requires only hand calculations on an ordinary wind rose. The theoretical method utilizes wind statistics computed after the bivariate normal elliptical distribution is applied to a data sample of component winds. This method requires only the assumption that the wind components are bivariate normally distributed. This assumption seems to be reasonable. Studies are currently in progress for testing wind components for bivariate normality for various stations. The close agreement between the theoretical and empirical results for the example chosen substantiates the bivariate normal assumption.

The digital phase-locked loop as a near-optimum FM demodulator.

NASA Technical Reports Server (NTRS)

Kelly, C. N.; Gupta, S. C.

1972-01-01

This paper presents an approach to the optimum digital demodulation of a continuous-time FM signal using stochastic estimation theory. The primary result is a digital phase-locked loop realization possessing performance characteristics that approach those of the analog counterpart. Some practical considerations are presented and simulation results for a first-order message model are presented.

The optimum content of rubber ash in concrete: flexural strength

NASA Astrophysics Data System (ADS)

Senin, M. S.; Shahidan, S.; Shamsuddin, S. M.; Ariffin, S. F. A.; Othman, N. H.; Rahman, R.; Khalid, F. S.; Nazri, F. M.

2017-11-01

Discarded scrap tyres have become one of the major environmental problems nowadays. Several studies have been carried out to reuse waste tires as an additive or sand replacement in concrete with appropriate percentages of tire rubber, called as rubberized concrete to solve this problem. The main objectives of this study are to investigate the flexural strength performance of concrete when adding the rubber ash and also to analyse the optimum content of rubber ash in concrete prisms. The performance total of 30 number of concrete prisms in size of 100mm x 100mm x 500 mm were investigated, by partially replacement of rubber ash with percentage of 0%, 3%, 5%, 7% and 9% from the volume of the sand. The flexural strength is increased when percentage of rubber ash is added 3% from control concrete prism, RA 0 for both concrete prism age, 7 days and 28 days with value 1.21% and 0.976% respectively. However, for RA 5, RA 7 and RA 9, the flexural strength was decreased compared to the control for both age, 7 days and 28 days. In conclusion, 3% is the optimum content of rubber ash in concrete prism for both concrete age

A determination of the optimum time of year for remotely classifying marsh vegetation from LANDSAT multispectral scanner data. [Louisiana

NASA Technical Reports Server (NTRS)

Butera, M. K. (Principal Investigator)

1978-01-01

The author has identified the following significant results. A technique was used to determine the optimum time for classifying marsh vegetation from computer-processed LANDSAT MSS data. The technique depended on the analysis of data derived from supervised pattern recognition by maximum likelihood theory. A dispersion index, created by the ratio of separability among the class spectral means to variability within the classes, defined the optimum classification time. Data compared from seven LANDSAT passes acquired over the same area of Louisiana marsh indicated that June and September were optimum marsh mapping times to collectively classify Baccharis halimifolia, Spartina patens, Spartina alterniflora, Juncus roemericanus, and Distichlis spicata. The same technique was used to determine the optimum classification time for individual species. April appeared to be the best month to map Juncus roemericanus; May, Spartina alterniflora; June, Baccharis halimifolia; and September, Spartina patens and Distichlis spicata. This information is important, for instance, when a single species is recognized to indicate a particular environmental condition.

Investigation of Requisites for the Optimal Mycelial Growth of the Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), on Oil Palm Biomass in Malaysia.

PubMed

Sudheer, Surya; Ali, Asgar; Manickam, Sivakumar

2016-01-01

Rigorous research has been carried out regarding the cultivation of Ganoderma lucidum using different agricultural residues. Nevertheless, large-scale cultivation and the separation of active compounds of G. lucidum are still challenges for local farmers. The objective of this study was to evaluate the use of oil palm waste fibers such as empty fruit bunch fibers and mesocarp fibers as effective substrates for the growth of G. lucidum mycelia to study the possibility of solid-state cultivation and to determine the optimum conditions necessary for the growth of mycelia of this mushroom on these waste fibers. Various parameters such as temperature, pH, humidity, and carbon and nitrogen compositions required for the optimum growth of mycelia have been determined. Oil palm fibers are a vivid source of lignocellulose, and their availability in Malaysia is high compared to that of sawdust. G. lucidum is a wood-rotting fungi that can easily decay and utilize this lignocellulose biomass, a major agricultural waste in Malaysia.

A General Multivariate Latent Growth Model with Applications to Student Achievement

ERIC Educational Resources Information Center

Bianconcini, Silvia; Cagnone, Silvia

2012-01-01

The evaluation of the formative process in the University system has been assuming an ever increasing importance in the European countries. Within this context, the analysis of student performance and capabilities plays a fundamental role. In this work, the authors propose a multivariate latent growth model for studying the performances of a…

Douglas-fir displays a range of growth responses to ...

EPA Pesticide Factsheets

Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) growth in the Pacific Northwest is affected by climatic, edaphic factors and Swiss needle cast (SNC) disease. We examine Douglas-fir growth responses to temperature, dewpoint deficit (DPD), soil moisture, and SNC using time series intervention analysis of intra-annual tree-ring width data collected at nine forest stands in western Oregon, USA. The effects of temperature and SNC were similar in importance on tree growth at all sites. Previous-year DPD during the annual drought period was a key factor limiting growth regionally. Winter temperature was more important at high elevation cool sites, whereas summer temperature was more important at warm and dry sites. Growth rate increased with summer temperature to an optimum (Topt) then decreased at higher temperatures. At drier sites, temperature and water affected growth interactively such that Topt decreased with decreasing summer soil moisture. With climate change, growth rates increased at high elevation sites and declined at mid-elevation inland sites since ~1990. Growth response to climate is masked by SNC regionally. We conclude that as temperature rises and precipitation patterns shift towards wetter winters and drier summers, Douglas-fir will experience greater temperature and water stress and an increase in severity of SNC. By the end of the 21st century, climate models predict hotter, drier summers and warmer, wetter winters in the Pac

Assessment of optimum threshold and particle shape parameter for the image analysis of aggregate size distribution of concrete sections

NASA Astrophysics Data System (ADS)

Ozen, Murat; Guler, Murat

2014-02-01

Aggregate gradation is one of the key design parameters affecting the workability and strength properties of concrete mixtures. Estimating aggregate gradation from hardened concrete samples can offer valuable insights into the quality of mixtures in terms of the degree of segregation and the amount of deviation from the specified gradation limits. In this study, a methodology is introduced to determine the particle size distribution of aggregates from 2D cross sectional images of concrete samples. The samples used in the study were fabricated from six mix designs by varying the aggregate gradation, aggregate source and maximum aggregate size with five replicates of each design combination. Each sample was cut into three pieces using a diamond saw and then scanned to obtain the cross sectional images using a desktop flatbed scanner. An algorithm is proposed to determine the optimum threshold for the image analysis of the cross sections. A procedure was also suggested to determine a suitable particle shape parameter to be used in the analysis of aggregate size distribution within each cross section. Results of analyses indicated that the optimum threshold hence the pixel distribution functions may be different even for the cross sections of an identical concrete sample. Besides, the maximum ferret diameter is the most suitable shape parameter to estimate the size distribution of aggregates when computed based on the diagonal sieve opening. The outcome of this study can be of practical value for the practitioners to evaluate concrete in terms of the degree of segregation and the bounds of mixture's gradation achieved during manufacturing.

Study on Formulation of Optimum Lighting-system for Purchasing Power at Stores

NASA Astrophysics Data System (ADS)

Fujita, Hiroki; Nakashima, Yoshio; Takamatsu, Mamoru; Oota, Masaaki; Sawa, Kazuhiro

In store lighting, difference in the look-and-feel of foods gives effects on the purchasing power of customers. This study conducted the digitalization and quantification on the effects of the variation of light-source color and illuminance used for lighting foods on image recognition on foods. As a result, it was clarified that when meat was illuminated with the light source of “pink” or “faint pink,” image evaluation on foods became higher. In addition, when illuminance increase was applied to these two light-source colors, image evaluation on “faint pink” became further higher. The reason is supposed to be that the redness of meat increased, which may have enhanced fresher impression. From this study, it has been clarified that the light-source color and illuminance optimum for each food are variant. The results show that lighting foods with the optimum light-source color and illuminance can make foods look better.

Selecting algorithms, sensors, and linear bases for optimum spectral recovery of skylight.

PubMed

López-Alvarez, Miguel A; Hernández-Andrés, Javier; Valero, Eva M; Romero, Javier

2007-04-01

In a previous work [Appl. Opt.44, 5688 (2005)] we found the optimum sensors for a planned multispectral system for measuring skylight in the presence of noise by adapting a linear spectral recovery algorithm proposed by Maloney and Wandell [J. Opt. Soc. Am. A3, 29 (1986)]. Here we continue along these lines by simulating the responses of three to five Gaussian sensors and recovering spectral information from noise-affected sensor data by trying out four different estimation algorithms, three different sizes for the training set of spectra, and various linear bases. We attempt to find the optimum combination of sensors, recovery method, linear basis, and matrix size to recover the best skylight spectral power distributions from colorimetric and spectral (in the visible range) points of view. We show how all these parameters play an important role in the practical design of a real multispectral system and how to obtain several relevant conclusions from simulating the behavior of sensors in the presence of noise.

Optimum Value of Original Events on the Pept Technique

NASA Astrophysics Data System (ADS)

Sadremomtaz, Alireza; Taherparvar, Payvand

2011-12-01

Do Positron emission particle tracking (PEPT) has been used to track the motion of a single radioactively labeled tracer particle within a bed of similar particles. In this paper, the effect of the original event fraction on the results precise in two experiments has been reviewed. Results showed that the algorithm can no longer distinguish some corrupt trajectories, in addition to; further iteration reduces the statistical significance of the sample without improving its quality. Results show that the optimum value of trajectories depends on the type of experiment.

Optimum filter-based discrimination of neutrons and gamma rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amiri, Moslem; Prenosil, Vaclav; Cvachovec, Frantisek

2015-07-01

An optimum filter-based method for discrimination of neutrons and gamma-rays in a mixed radiation field is presented. The existing filter-based implementations of discriminators require sample pulse responses in advance of the experiment run to build the filter coefficients, which makes them less practical. Our novel technique creates the coefficients during the experiment and improves their quality gradually. Applied to several sets of mixed neutron and photon signals obtained through different digitizers using stilbene scintillator, this approach is analyzed and its discrimination quality is measured. (authors)

Size and composition-controlled fabrication of VO2 nanocrystals by terminated cluster growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anders, Andre; Slack, Jonathan

2013-05-14

A physical vapor deposition-based route for the fabrication of VO2 nanoparticles is demonstrated, consisting of reactive sputtering and vapor condensation at elevated pressures. The oxidation of vanadium atoms is an efficient heterogeneous nucleation method, leading to high nanoparticle throughtput. Fine control of the nanoparticle size and composition is obtained. Post growth annealing leads to crystalline VO2 nanoparticles with optimum thermocromic and plasmonic properties.

Crystal growth of device quality GaAs in space

NASA Technical Reports Server (NTRS)

Gatos, H. C.; Lagowski, J.

1985-01-01

The present program has been aimed at solving the fundamental and technological problems associated with Crystal Growth of Device Quality in Space. The initial stage of the program was devoted strictly to ground-based research. The unsolved problems associated with the growth of bulk GaAs in the presence of gravitational forces were explored. Reliable chemical, structural and electronic characterization methods were developed which would permit the direct relation of the salient materials parameters (particularly those affected by zero gravity conditions) to the electronic characteristics of single crystal GaAs, in turn to device performance. These relationships are essential for the development of optimum approaches and techniques. It was concluded that the findings on elemental semiconductors Ge and Si regarding crystal growth, segregation, chemical composition, defect interactions, and materials properties-electronic properties relationships are not necessarily applicable to GaAs (and to other semiconductor compounds). In many instances totally unexpected relationships were found to prevail.

Hybrid maize breeding with doubled haploids: II. Optimum type and number of testers in two-stage selection for general combining ability.

PubMed

Longin, C Friedrich H; Utz, H Friedrich; Melchinger, Albrecht E; Reif, Jochen C

2007-02-01

Optimum allocation of test resources is of crucial importance for the efficiency of breeding programs. Our objectives were to (1) determine the optimum allocation of the number of lines, test locations, as well as number and type of testers in hybrid maize breeding using doubled haploids with two breeding strategies for improvement of general combining ability (GCA), (2) compare the maximum selection gain (DeltaG) achievable under both strategies, and (3) give recommendations for the optimum implementation of doubled haploids in commercial hybrid maize breeding. We calculated DeltaG by numerical integration for two two-stage selection strategies with evaluation of (1) testcross performance in both stages (BS1) or (2) line per se performance in the first stage followed by testcross performance in the second stage (BS2). Different assumptions were made regarding the budget, variance components (VCs), and the correlation between line per se performance and GCA. Selection gain for GCA increased with a broader genetic base of the tester. Hence, testers combining a large number of divergent lines are advantageous. However, in applied breeding programs, the use of single- or double-cross testers in the first and inbred testers in the second selection stage may be a good compromise between theoretical and practical requirements. With a correlation between line per se performance and GCA of 0.50, DeltaG for BS1 is about 5% higher than for BS2, if an economic weight of line per se performance is neglected. With increasing economic weight of line per se performance, relative efficiency of BS2 increased rapidly resulting in a superiority of BS2 over BS1 already for an economic weight for line per se performance larger than 0.1. Considering the importance of an economic seed production, an economic weight larger than 0.1 seems realistic indicating the necessity of separate breeding strategies for seed and pollen parent heterotic groups.

Investigation of optimum conditions and costs estimation for degradation of phenol by solar photo-Fenton process

NASA Astrophysics Data System (ADS)

Gar Alalm, Mohamed; Tawfik, Ahmed; Ookawara, Shinichi

2017-03-01

In this study, solar photo-Fenton reaction using compound parabolic collectors reactor was assessed for removal of phenol from aqueous solution. The effect of irradiation time, initial concentration, initial pH, and dosage of Fenton reagent were investigated. H2O2 and aromatic intermediates (catechol, benzoquinone, and hydroquinone) were quantified during the reaction to study the pathways of the oxidation process. Complete degradation of phenol was achieved after 45 min of irradiation when the initial concentration was 100 mg/L. However, increasing the initial concentration up to 500 mg/L inhibited the degradation efficiency. The dosage of H2O2 and Fe+2 significantly affected the degradation efficiency of phenol. The observed optimum pH for the reaction was 3.1. Phenol degradation at different concentration was fitted to the pseudo-first order kinetic according to Langmuir-Hinshelwood model. Costs estimation for a large scale reactor based was performed. The total costs of the best economic condition with maximum degradation of phenol are 2.54 €/m3.

Lunar base agriculture: Soils for plant growth

NASA Technical Reports Server (NTRS)

Ming, Douglas W. (Editor); Henninger, Donald L. (Editor)

1989-01-01

This work provides information on research and experimentation concerning various aspects of food production in space and particularly on the moon. Options for human settlement of the moon and Mars and strategies for a lunar base are discussed. The lunar environment, including the mineralogical and chemical properties of lunar regolith are investigated and chemical and physical considerations for a lunar-derived soil are considered. It is noted that biological considerations for such a soil include controlled-environment crop production, both hydroponic and lunar regolith-based; microorganisms and the growth of higher plants in lunar-derived soils; and the role of microbes to condition lunar regolith for plant cultivation. Current research in the controlled ecological life support system (CELSS) project is presented in detail and future research areas, such as the growth of higher research plants in CELSS are considered. Optimum plant and microbiological considerations for lunar derived soils are examined.

Short-term departures from an optimum ambient temperature are associated with increased risk of out-of-hospital cardiac arrest.

PubMed

Dahlquist, Marcus; Raza, Auriba; Bero-Bedada, Getahun; Hollenberg, Jacob; Lind, Tomas; Orsini, Nicola; Sjögren, Bengt; Svensson, Leif; Ljungman, Petter L

2016-07-01

Associations have been reported between daily ambient temperature and all-cause and cardiovascular mortality. However, the potential harmful effect of temperature on out-of-hospital cardiac arrest (OHCA) is insufficiently studied. The objective of this study was to investigate the short-term association between ambient temperature and the occurrence of OHCA. In 5961 cases of OHCAs treated by Emergency Medical Service occurring in Stockholm County we investigated the association between the preceding 24-h and 1h mean ambient temperature, obtained from a fixed monitoring station, and OHCA using a time-stratified case-crossover design. We observed a V-shaped relationship between preceding mean 24-h and 1-h ambient temperature and the occurrence of OHCAs. For mean 24-h temperature we observed an odds ratio (OR) of 1.05 (1.00-1.11) for each 5°C below the optimum temperature and 1.05 (0.96-1.18) for each 5°C above the optimum. We observed similar results for 1-h mean temperature exposure. Results for temperatures above the optimum temperature showed evidence of confounding by ozone. Ambient temperature below an optimum temperature was associated with increased risk of OHCA in Stockholm. Temperature above an optimum temperature was not significantly associated with OHCA. Copyright © 2016 Elsevier GmbH. All rights reserved.

A class of optimum digital phase locked loops for the DSN advanced receiver

NASA Technical Reports Server (NTRS)

Hurd, W. J.; Kumar, R.

1985-01-01

A class of optimum digital filters for digital phase locked loop of the deep space network advanced receiver is discussed. The filter minimizes a weighted combination of the variance of the random component of the phase error and the sum square of the deterministic dynamic component of phase error at the output of the numerically controlled oscillator (NCO). By varying the weighting coefficient over a suitable range of values, a wide set of filters are obtained such that, for any specified value of the equivalent loop-noise bandwidth, there corresponds a unique filter in this class. This filter thus has the property of having the best transient response over all possible filters of the same bandwidth and type. The optimum filters are also evaluated in terms of their gain margin for stability and their steady-state error performance.

Optimum three-dimensional atmospheric entry from the analytical solution of Chapman's exact equations

NASA Technical Reports Server (NTRS)

Busemann, A.; Vinh, N. X.; Culp, R. D.

1974-01-01

The general solution for the optimum three-dimensional aerodynamic control of a lifting vehicle entering a planetary atmosphere is developed. A set of dimensionless variables, modified Chapman variables, is introduced. The resulting exact equations of motion, referred to as Chapman's exact equations, have the advantage that they are completely free of the physical characteristics of the vehicle. Furthermore, a completely general lift-drag relationship is used in the derivation. The results obtained apply to any type of vehicle of arbitrary weight, dimensions and shape, having an arbitrary drag polar, and entering any planetary atmosphere. The aerodynamic controls chosen are the lift coefficient and the bank angle. General optimum control laws for these controls are developed. Several earlier particular solutions are shown to be special cases of this general result. Results are valid for both free and constrained terminal position.

Effect of School Belonging Trajectories in Grades 6–8 on Achievement: Gender and Ethnic Differences

PubMed Central

Hughes, Jan N.; Im, Myung Hee; Allee, Paula J.

2015-01-01

This study investigated the association between trajectories of school belonging across grades 6–8 and academic achievement in grade 8 in an ethnically diverse sample of 527 academically at-risk adolescents. Students reported annually on school belonging. Reading and math achievement were assessed at grade 5 (baseline) and grade 8. Interactive effects of gender and ethnicity were found in the conditional growth models for school belonging. Girls of all ethnicities had identical growth trajectories and reported higher initial school belonging than Euro-American or Latino boys. Latino and Euro-American males had lower initial level of school belonging than African American males, and Latino males had lower growth in school belonging than Euro-American males. In structural equation modeling (SEM) analyses, initial level of school belonging predicted grade 8 reading for girls and grade 8 math for boys and girls, above prior achievement and school and child covariates, but growth in school belonging predicted grade 8 achievement only for African American students. Implications for strategies to improve school belonging among academically at-risk youth are discussed. PMID:26563601

Optimum design of Geodesic dome’s jointing system

NASA Astrophysics Data System (ADS)

Tran, Huy. T.

2018-04-01

This study attempts to create a new design for joint connector of Geodesic dome. A new type of joint connector design is proposed for flexible rotating connection; comparing it to another, this design is cheaper and workable. After calculating the bearing capacity of the sample according to EC3 and Vietnam standard TCVN 5575-2012, FEM model of the design sample is carried out in many specific situation to consider the stress distribution, the deformation, the local destruction… in the connector. The analytical results and the FE data are consistent. The FE analysis also points out the behavior of some details that simple calculation cannot show. Hence, we can choose the optimum design of joint connector.

The effect of crumb rubber particle size to the optimum binder content for open graded friction course.

PubMed

Ibrahim, Mohd Rasdan; Katman, Herda Yati; Karim, Mohamed Rehan; Koting, Suhana; Mashaan, Nuha S

2014-01-01

The main objective of this paper is to investigate the relations of rubber size, rubber content, and binder content in determination of optimum binder content for open graded friction course (OGFC). Mix gradation type B as specified in Specification for Porous Asphalt produced by the Road Engineering Association of Malaysia (REAM) was used in this study. Marshall specimens were prepared with four different sizes of rubber, namely, 20 mesh size [0.841 mm], 40 mesh [0.42 mm], 80 mesh [0.177 mm], and 100 mesh [0.149 mm] with different concentrations of rubberised bitumen (4%, 8%, and 12%) and different percentages of binder content (4%-7%). The appropriate optimum binder content is then selected according to the results of the air voids, binder draindown, and abrasion loss test. Test results found that crumb rubber particle size can affect the optimum binder content for OGFC.

The Impact of Formative Assessment on Students in a High Achieving Middle School

ERIC Educational Resources Information Center

Toungette, William Thomas

2012-01-01

With the passage of the No Child Left Behind mandate, school systems clamored to ensure that all students showed academic growth. For schools with a high-achieving population, this could be a daunting task. This analysis examined the impact formative assessment had on student achievement in a high-achieving, middle school by measuring three…

Defining poor and optimum performance in an IVF programme.

PubMed

Castilla, Jose A; Hernandez, Juana; Cabello, Yolanda; Lafuente, Alejandro; Pajuelo, Nuria; Marqueta, Javier; Coroleu, Buenaventura

2008-01-01

At present there is considerable interest in healthcare administration, among professionals and among the general public concerning the quality of programmes of assisted reproduction. There exist various methods for comparing and analysing the results of clinical activity, with graphical methods being the most commonly used for this purpose. As yet, there is no general consensus as to how the poor performance (PP) or optimum performance (OP) of assisted reproductive technologies should be defined. Data from the IVF/ICSI register of the Spanish Fertility Society were used to compare and analyse different definitions of PP or OP. The primary variable best reflecting the quality of an IVF/ICSI programme was taken to be the percentage of singleton births per IVF/ICSI cycle initiated. Of the 75 infertility clinics that took part in the SEF-2003 survey, data on births were provided by 58. A total of 25 462 cycles were analysed. The following graphical classification methods were used: ranking of the proportion of singleton births per cycles started in each centre (league table), Shewhart control charts, funnel plots, best and worst-case scenarios and state of the art methods. The clinics classified as producing PP or OP varied considerably depending on the classification method used. Only three were rated as providing 'PP' or 'OP' by all methods, unanimously. Another four clinics were classified as 'poor' or 'optimum' by all the methods except one. On interpreting the results derived from IVF/ICSI centres, it is essential to take into account the characteristics of the method used for this purpose.

Optimum flight paths of turbojet aircraft

NASA Technical Reports Server (NTRS)

Miele, Angelo

1955-01-01

The climb of turbojet aircraft is analyzed and discussed including the accelerations. Three particular flight performances are examined: minimum time of climb, climb with minimum fuel consumption, and steepest climb. The theoretical results obtained from a previous study are put in a form that is suitable for application on the following simplifying assumptions: the Mach number is considered an independent variable instead of the velocity; the variations of the airplane mass due to fuel consumption are disregarded; the airplane polar is assumed to be parabolic; the path curvatures and the squares of the path angles are disregarded in the projection of the equation of motion on the normal to the path; lastly, an ideal turbojet with performance independent of the velocity is involved. The optimum Mach number for each flight condition is obtained from the solution of a sixth order equation in which the coefficients are functions of two fundamental parameters: the ratio of minimum drag in level flight to the thrust and the Mach number which represents the flight at constant altitude and maximum lift-drag ratio.

The Development of Science Achievement in Middle and High School: Individual Differences and School Effects.

ERIC Educational Resources Information Center

Ma, Xin; Wilkins, Jessie L. M.

2002-01-01

Used hierarchical linear models with data from the Longitudinal Study of American Youth to model the growth of student science achievement in biology, physical science, and environmental science during middle and high school. Growth was quadratic across all areas, with rapid growth at the beginning of middle school and slow growth at the ending…

An iterative method for obtaining the optimum lightning location on a spherical surface

NASA Technical Reports Server (NTRS)

Chao, Gao; Qiming, MA

1991-01-01

A brief introduction to the basic principles of an eigen method used to obtain the optimum source location of lightning is presented. The location of the optimum source is obtained by using multiple direction finders (DF's) on a spherical surface. An improvement of this method, which takes the distance of source-DF's as a constant, is presented. It is pointed out that using a weight factor of signal strength is not the most ideal method because of the inexact inverse signal strength-distance relation and the inaccurate signal amplitude. An iterative calculation method is presented using the distance from the source to the DF as a weight factor. This improved method has higher accuracy and needs only a little more calculation time. Some computer simulations for a 4DF system are presented to show the improvement of location through use of the iterative method.

Purification, Characterization, and Optimum Conditions of Fermencin SD11, a Bacteriocin Produced by Human Orally Lactobacillus fermentum SD11.

PubMed

Wannun, Phirawat; Piwat, Supatcharin; Teanpaisan, Rawee

2016-06-01

Fermencin SD11, a bacteriocin produced by human orally Lactobacillus fermentum SD11, was purified, characterized, and optimized in conditions for bacterial growth and bacteriocin production. Fermencin SD11 was purified using three steps of ammonium sulfate precipitation, gel filtration chromatography, and reverse-phase high-performance liquid chromatography. The molecular weight was found to be 33,000 Da using SDS-PAGE and confirmed as 33,593.4 Da by liquid chromatography-mass spectrometry. Fermencin SD11 exhibited activity against a wide range of oral pathogens including cariogenic and periodontogenic pathogens and Candida. The active activity was stable between 60 - 80 °C in a pH range of 3.0 to 7.0. It was sensitive to proteolytic enzymes (proteinase K and trypsin), but it was not affected by α-amylase, catalase, lysozyme, and saliva. The optimum conditions for growth and bacteriocin production of L. fermentum SD11 were cultured at acidic with pH of 5.0-6.0 at 37 or 40 °C under aerobic or anaerobic conditions for 12 h. It is promising that L. fermentum SD11 and its bacteriocin may be an alternative approach for promoting oral health or prevention of oral diseases, e.g., dental caries and periodontitis, which would require further clinical trials.

Development of guidelines for optimum baghouse fluid-dynamic-system design. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eskinazi, D.; Gilbert, G.B.

1982-06-01

In recent years, the utility industry has turned to fabric filters as an alternative technology to electrostatic precipitators for particulate emission control from pulverized coal-fired power plants. One aspect of baghouse technology which appears to be of major importance in minimizing the size, cost, and operating pressure drop is the development of ductwork and compartment designs which achieve uniform gas and dust flow distribution to individual compartments and bags within a compartment. The objective of this project was to perform an experimental modeling program to develop design guidelines for optimizing the fluid mechanic performance of baghouses. Tasks included formulation ofmore » the appropriate modeling techniques for analysis of the flow of dust-laden gas through the collector system and extensive experimental analysis of fabric filter duct system design. A matrix of geometric configurations and operating conditions was experimentally investigated to establish the characteristics of an optimum system, to identify the level of fluid mechanic sophistication in current designs, and to experimentally develop new ideas and improved designs. Experimental results indicate that the design of the inlet and outlet manifolds, hopper entrance, hopper region below the tubesheet, and the compartment outlet have not been given sufficient attention. Unsteady flow patterns, poor velocity profiles, recirculation zones, and excessive pressure losses may be associated with these regions. It is evident from the results presented here that the fluid mechanic design of fabric filter systems can be improved significantly.« less

Microstructural Investigation of Heat-Treated Ultra-High Performance Concrete for Optimum Production.

PubMed

Kang, Sung-Hoon; Lee, Ji-Hyung; Hong, Sung-Gul; Moon, Juhyuk

2017-09-20

For optimum production of ultra-high performance concrete (UHPC), the material and microstructural properties of UHPC cured under various heat treatment (HT) conditions are studied. The effects of HT temperature and duration on the hydration reaction, microstructure, and mechanical properties of UHPC are investigated. Increasing HT temperature accelerates both cement hydration and pozzolanic reaction, but the latter is more significantly affected. This accelerated pozzolanic reaction in UHPC clearly enhances compressive strength. However, strength after the HT becomes stable as most of the hydration finishes during the HT period. Particularly, it was concluded that the mechanical benefit of the increased temperature and duration on the 28 day-strength is not noticeable when the HT temperature is above 60 °C (with a 48 h duration) or the HT duration is longer than 12 h (with 90 °C temperature). On the other hand, even with a minimal HT condition such as 1 day at 60 °C or 12 h at 90 °C, outstanding compressive strength of 179 MPa and flexural tensile strength of 49 MPa are achieved at 28 days. Microstructural investigation conducted herein suggests that portlandite content can be a good indicator for the mechanical performance of UHPC regardless of its HT curing conditions. These findings can contribute to reducing manufacturing energy consumption, cost, and environmental impact in the production of UHPC and be helpful for practitioners to better understand the effect of HT on UHPC and optimize its production.

The optimum measurement precision evaluation for blood components using near-infrared spectra on 1000-2500 nm

NASA Astrophysics Data System (ADS)

Zhang, Ziyang; Sun, Di; Han, Tongshuai; Guo, Chao; Liu, Jin

2016-10-01

In the non-invasive blood components measurement using near infrared spectroscopy, the useful signals caused by the concentration variation in the interested components, such as glucose, hemoglobin, albumin etc., are relative weak. Then the signals may be greatly disturbed by a lot of noises in various ways. We improved the signals by using the optimum path-length for the used wavelength to get a maximum variation of transmitted light intensity when the concentration of a component varies. And after the path-length optimization for every wavelength in 1000-2500 nm, we present the detection limits for the components, including glucose, hemoglobin and albumin, when measuring them in a tissue phantom. The evaluated detection limits could be the best reachable precision level since it assumed the measurement uses a high signal-to-noise ratio (SNR) signal and the optimum path-length. From the results, available wavelengths in 1000-2500 nm for the three component measurements can be screened by comparing their detection limit values with their measurement limit requirements. For other blood components measurement, the evaluation their detection limits could also be designed using the method proposed in this paper. Moreover, we use an equation to estimate the absorbance at the optimum path-length for every wavelength in 1000-2500 nm caused by the three components. It could be an easy way to realize the evaluation because adjusting the sample cell's size to the precise path-length value for every wavelength is not necessary. This equation could also be referred to other blood components measurement using the optimum path-length for every used wavelength.

Early photosensitizer uptake kinetics predict optimum drug-light interval for photodynamic therapy

NASA Astrophysics Data System (ADS)

Sinha, Lagnojita; Elliott, Jonathan T.; Hasan, Tayyaba; Pogue, Brian W.; Samkoe, Kimberley S.; Tichauer, Kenneth M.

2015-03-01

Photodynamic therapy (PDT) has shown promising results in targeted treatment of cancerous cells by developing localized toxicity with the help of light induced generation of reactive molecular species. The efficiency of this therapy depends on the product of the intensity of light dose and the concentration of photosensitizer (PS) in the region of interest (ROI). On account of this, the dynamic and variable nature of PS delivery and retention depends on many physiological factors that are known to be heterogeneous within and amongst tumors (e.g., blood flow, blood volume, vascular permeability, and lymph drainage rate). This presents a major challenge with respect to how the optimal time and interval of light delivery is chosen, which ideally would be when the concentration of PS molecule is at its maximum in the ROI. In this paper, a predictive algorithm is developed that takes into consideration the variability and dynamic nature of PS distribution in the body on a region-by-region basis and provides an estimate of the optimum time when the PS concentration will be maximum in the ROI. The advantage of the algorithm lies in the fact that it predicts the time in advance as it takes only a sample of initial data points (~12 min) as input. The optimum time calculated using the algorithm estimated a maximum dose that was only 0.58 +/- 1.92% under the true maximum dose compared to a mean dose error of 39.85 +/- 6.45% if a 1 h optimal light deliver time was assumed for patients with different efflux rate constants of the PS, assuming they have the same plasma function. Therefore, if the uptake values of PS for the blood and the ROI is known for only first 12 minutes, the entire curve along with the optimum time of light radiation can be predicted with the help of this algorithm.

Teacher-Child Interactions and Children's Achievement Trajectories across Kindergarten and First Grade

ERIC Educational Resources Information Center

Curby, Timothy W.; Rimm-Kaufman, Sara E.; Ponitz, Claire Cameron

2009-01-01

This study examined the extent to which the quality of teacher-child interactions and children's achievement levels at kindergarten entry were associated with children's achievement trajectories. Rural students (n = 147) were enrolled in a longitudinal study from kindergarten through first grade. Growth trajectories (initial level and slope) were…

The Effect of Crumb Rubber Particle Size to the Optimum Binder Content for Open Graded Friction Course

PubMed Central

Ibrahim, Mohd Rasdan; Katman, Herda Yati; Karim, Mohamed Rehan; Koting, Suhana; Mashaan, Nuha S.

2014-01-01

The main objective of this paper is to investigate the relations of rubber size, rubber content, and binder content in determination of optimum binder content for open graded friction course (OGFC). Mix gradation type B as specified in Specification for Porous Asphalt produced by the Road Engineering Association of Malaysia (REAM) was used in this study. Marshall specimens were prepared with four different sizes of rubber, namely, 20 mesh size [0.841 mm], 40 mesh [0.42 mm], 80 mesh [0.177 mm], and 100 mesh [0.149 mm] with different concentrations of rubberised bitumen (4%, 8%, and 12%) and different percentages of binder content (4%–7%). The appropriate optimum binder content is then selected according to the results of the air voids, binder draindown, and abrasion loss test. Test results found that crumb rubber particle size can affect the optimum binder content for OGFC. PMID:24574875

Determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution

NASA Technical Reports Server (NTRS)

Ioup, George E.; Ioup, Juliette W.

1991-01-01

The final report for work on the determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution is presented. Papers and theses prepared during the research report period are included. Among all the research results reported, note should be made of the specific investigation of the determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution. A methodology was developed to determine design and operation parameters for error minimization when deconvolution is included in data analysis. An error surface is plotted versus the signal-to-noise ratio (SNR) and all parameters of interest. Instrumental characteristics will determine a curve in this space. The SNR and parameter values which give the projection from the curve to the surface, corresponding to the smallest value for the error, are the optimum values. These values are constrained by the curve and so will not necessarily correspond to an absolute minimum in the error surface.

The containment of world population growth.

PubMed

Caldwell, J C

1975-12-01

The world has reached the present position of unprecedentedly rapid population growth not by achieving uniquely high fertility but by bringing about extraordinarily low mortality. The high growth rate and the built-in momentum of the age structure are obstacles to achievement of an acceptable standard of living for most of the world's population. Although government population programs have the potential to curb this growth rate, this potential has not been realized, and such programs are too often perceived both by their administrators and the population concerned as an end in themselves rather than a means toward a better standard of living. It is in this latter perspective, and in the context of the total development process, that population programs should be implemented.

Optimization of medium components and physicochemical parameters to simultaneously enhance microbial growth and production of lypolitic enzymes by Stenotrophomonas sp.

PubMed

Mazzucotelli, Cintia Anabela; Agüero, María Victoria; Del Rosario Moreira, María; Ansorena, María Roberta

2016-05-01

The optimization of lipase and esterase production (LP and EP) and bacterial growth (BG) of a Stenotrophomonas sp. strain was developed. For this purpose, the effect of five different medium components and three physicochemical parameters were evaluated using a Plackett-Burman statistical design. Among eight variables, stirring speed, pH, and peptone concentration were found to be the most effective factors on the three responses under evaluation. An optimization study applying Box-Behnken response surface methodology was used to study the interactive effects of the three selected variables on LP/EP and microorganism growth. Predicted models were found to be significant with high regression coefficients (90%-99%). By using the desirability function approach, the optimum condition applying simultaneous optimization of the three responses under study resulted to be: stirring speed of 100 rpm, pH of 7.5, and a peptone concentration of 10 g/L, with a desirability value of 0.977. Under these optimal conditions, it is possible to achieve in the optimized medium a 15-fold increase in esterase productivity, a 117-fold increase in lipase production, and a 9-log CFU/mL increase in BG, compared with the basal medium without agitation. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

Prediction of the optimum hybridization conditions of dot-blot-SNP analysis using estimated melting temperature of oligonucleotide probes.

PubMed

Shiokai, Sachiko; Kitashiba, Hiroyasu; Nishio, Takeshi

2010-08-01

Although the dot-blot-SNP technique is a simple cost-saving technique suitable for genotyping of many plant individuals, optimization of hybridization and washing conditions for each SNP marker requires much time and labor. For prediction of the optimum hybridization conditions for each probe, we compared T (m) values estimated from nucleotide sequences using the DINAMelt web server, measured T (m) values, and hybridization conditions yielding allele-specific signals. The estimated T (m) values were comparable to the measured T (m) values with small differences of less than 3 degrees C for most of the probes. There were differences of approximately 14 degrees C between the specific signal detection conditions and estimated T (m) values. Change of one level of SSC concentrations of 0.1, 0.2, 0.5, and 1.0x SSC corresponded to a difference of approximately 5 degrees C in optimum signal detection temperature. Increasing the sensitivity of signal detection by shortening the exposure time to X-ray film changed the optimum hybridization condition for specific signal detection. Addition of competitive oligonucleotides to the hybridization mixture increased the suitable hybridization conditions by 1.8. Based on these results, optimum hybridization conditions for newly produced dot-blot-SNP markers will become predictable.

Validation of a predictive model for the growth of chalk yeasts on bread.

PubMed

Burgain, Anaïs; Bensoussan, Maurice; Dantigny, Philippe

2015-07-02

The present study focused on the effects of temperature, T, and water activity, aw, on the growth of Hyphopichia burtonii, Pichia anomala, and Saccharomycopsis fibuligera on Sabouraud Agar Medium. Cardinal values were estimated by means of cardinal models with inflection. All the yeasts were xerophilic, and they exhibited growth at 0.85 aw. The combined effects of T, aw, and pH on the growth of these species were described by the gamma-concept and validated on bread in the range of 15-25 °C, 0.91-0.97 aw, and pH 4.6-6.8. The optimum growth rates on bread were 2.88, 0.259, and 1.06 mm/day for H. burtonii, P. anomala, and S. fibuligera, respectively. The optimal growth rate of S. fibuligera on bread was about 2 fold that obtained on Sabouraud. Due to reproduction by budding, P. anomala exhibited low growth on Sabouraud and bread. However, this species is of major concern in the baker's industry because of the production of ethyl acetate in bread. Copyright © 2015 Elsevier B.V. All rights reserved.

Oriented molecular sieve membranes by heteroepitaxial growth.

PubMed

Jeong, Hae-Kwon; Krohn, John; Sujaoti, Khristina; Tsapatsis, Michael

2002-11-06

Heteroepitaxial growth of titanosilicates (ETS-10 and ETS-4) is reported. Using this heteroepitaxial growth, oriented ETS-10/-4 membranes have been fabricated, demonstrating a novel way to achieve preferred orientation of molecular sieve films.

Growth of Aureobasidium pullulans on straw hydrolysate.

PubMed Central

Han, Y W; Cheeke, P R; Anderson, A W; Lekprayoon, C

1976-01-01

Growth characteristics and cell properties of Aureobasidium (Pullularia) pullulans were studied. The organism grew well on an acid hydrolysate of ryegrass straw over a wide range of pH and temperature. The optimum temperature and pH for the growth of the organism were 32 degrees C and 5.5, respectively. A cell yield of 1.5 g/liter of straw hydrolysate was obtained. The dried cell mass contained 42.6% crude protein, 0.4% crude fat, and 6.4% nucleic acids. The essential amino acid profile of the microbial protein was comparable to that of Candida utilis. A rat feeding study indicated that the A. pullulans cells were not toxic and that the feed intake, weight gain, and protein efficiency ratio values were superior to those obtained with C. utilis. Once the question of mathogenicity is resolved, A. pullulans could be useful for production of single-cell protein from cellulosic wastes. PMID:12721

The kinetics of chirality assignment in catalytic single-walled carbon nanotube growth and the routes towards selective growth.

PubMed

Xu, Ziwei; Qiu, Lu; Ding, Feng

2018-03-21

Depending on its specific structure, or so-called chirality, a single-walled carbon nanotube (SWCNT) can be either a conductor or a semiconductor. This feature ensures great potential for building ∼1 nm sized electronics if chirality-selected SWCNTs could be achieved. However, due to the limited understanding of the growth mechanism of SWCNTs, reliable methods for chirality-selected SWCNTs are still pending. Here we present a theoretical model on the chirality assignment and control of SWCNTs during the catalytic growth. This study reveals that the chirality of a SWCNT is determined by the kinetic incorporation of pentagons, especially the last (6 th ) one, during the nucleation stage. Our analysis showed that the chirality of a SWCNT is randomly assigned on a liquid or liquid-like catalyst surface, and two routes of synthesizing chirality-selected SWCNTs, which are verified by recent experimental achievements, are demonstrated. They are (i) by using high melting point crystalline catalysts, such as Ta, W, Re, Os, or their alloys, and (ii) by frequently changing the chirality of SWCNTs during their growth. This study paves the way for achieving chirality-selective SWCNT growth for high performance SWCNT based electronics.

Murray's law, the "Yarrum'" optimum, and the hydraulic architecture of compound leaves

Treesearch

Katherine A. McCulloh; John S. Sperry; Frederick C. Meinzer; Barbara Lachenbruch; Cristian Atala

2009-01-01

There are two optima for maximizing hydraulic conductance per vasculature volume in plants. Murray's law (ML) predicts the optimal conduit taper for a fixed change in conduit number across branch ranks. The opposite, the Yarrum optimum (YO), predicts the optimal change in conduit number for a fixed taper. We derived the solution for YO and then evaluated...

Optimum detection of tones transmitted by a spacecraft

NASA Technical Reports Server (NTRS)

Simon, M. K.; Shihabi, M. M.; Moon, T.

1995-01-01

The performance of a scheme proposed for automated routine monitoring of deep-space missions is presented. The scheme uses four different tones (sinusoids) transmitted from the spacecraft (S/C) to a ground station with the positive identification of each of them used to indicate different states of the S/C. Performance is measured in terms of detection probability versus false alarm probability with detection signal-to-noise ratio as a parameter. The cases where the phase of the received tone is unknown and where both the phase and frequency of the received tone are unknown are treated separately. The decision rules proposed for detecting the tones are formulated from average-likelihood ratio and maximum-likelihood ratio tests, the former resulting in optimum receiver structures.

The Impact of Graphing Calculators on Math Achievement: A Quantitative, Longevity Analysis

ERIC Educational Resources Information Center

Arbini, Corey

2016-01-01

This study examined the impact of high school students' graphing calculator usage on their math achievement over time. Achievement growth was measured using nationally-recognized standardized test scores from EXPLORE, PLAN, and ACT. Two groups of students were used in this study; one group had graphing calculators integrated beginning in…

Weight-watching at the university: the consequences of growth.

PubMed

Gallant, J A; Prothero, J W

1972-01-28

We began by pointing out that tools (for example) have size optima that are dictated by function. If we assume that the university has a function, it would seem reasonable to think about the size which will serve that function best. The principle of size optimization is fundamental, but its application to the university at once encounters a difficulty: What is the function of a university? It might take forever to secure general agreement on the answer to this question. The problem is that universities have a number of different functions, to which different individuals will attach different weights, and each function may well have a unique size optimum. Just as it is, in general, mathematically impossible to maximize simultaneously for two different functions of the same variable (29), so it is unsound to conceive of a single optimum for the multiversity. Nonetheless, a range of workable sizes may be defined by analyzing the effect of variation in size on all essential functions. The examples from biological systems illustrate this approach. Cells exist in a variety of sizes, each size presumably representing an optimization to one or another set of constraints, yet there are upper bounds. There are no cells the size of basketballs because essential metabolic functions are limited by the surface-to-volume ratio. We must emphasize that one does not need a grand theory of life in order to identify this limiting condition. If cells could talk, they would no doubt differ on the general philosophy of being a cell, yet all conceptions would be subject to certain physically inevitable limitations on size. In the case of the university, no grand theory of education is needed in order to identify dysfunctions of growth that affect essential activities (for example, the diffusion of individuals through, in, and out of the university) or that affect all activities (for example, overall morale). Balanced against these dysfunctions are such advantages of growth as economy, the

Alkalilimnicola ehrlichii sp. nov., a novel, arsenite-oxidizing haloalkaliphilic gammaproteobacterium capable of chemoautotrophic or heterotrophic growth with nitrate or oxygen as the electron acceptor

USGS Publications Warehouse

Hoeft, S.E.; Blum, J.S.; Stolz, J.F.; Tabita, F.R.; Witte, B.; King, G.M.; Santini, J.M.; Oremland, R.S.

2007-01-01

A facultative chemoautotrophic bacterium, strain MLHE-1T, was isolated from Mono Lake, an alkaline hypersaline soda lake in California, USA. Cells of strain MLHE-1T were Gram-negative, short motile rods that grew with inorganic electron donors (arsenite, hydrogen, sulfide or thiosulfate) coupled with the reduction of nitrate to nitrite. No aerobic growth was attained with arsenite or sulfide, but hydrogen sustained both aerobic and anaerobic growth. No growth occurred when nitrite or nitrous oxide was substituted for nitrate. Heterotrophic growth was observed under aerobic and anaerobic (nitrate) conditions. Cells of strain MLHE-1T could oxidize but not grow on CO, while CH4 neither supported growth nor was it oxidized. When grown chemoautotrophically, strain MLHE-1T assimilated inorganic carbon via the Calvin-Benson-Bassham reductive pentose phosphate pathway, with the activity of ribulose 1,5-bisphosphate carboxylase (RuBisCO) functioning optimally at 0.1 M NaCl and at pH 7.3. Strain MLHE-1T grew over broad ranges of pH (7.3-10.0; optimum, 9.3), salinity (115-190 g l-1; optimum 30 g l-1) and temperature (113-40 ??C; optimum, 30 ??C). Phylogenetic analysis of 16S rRNA gene sequences placed strain MLHE-1T in the class Gammaproteobacteria (family Ectothiorhodospiraceae) and most closely related to Alkalispirillum mobile (98.5%) and Alkalilimnicola halodurans (98.6%), although none of these three haloalkaliphilic micro-organisms were capable of photoautotrophic growth and only strain MLHE-1T was able to oxidize As(III). On the basis of physiological characteristics and DNA-DNA hybridization data, it is suggested that strain MLHE-1T represents a novel species within the genus Alkalilimnicola for which the name Alkalilimnicola ehrlichii is proposed. The type strain is MLHE-1T (=DSM 17681T =ATCC BAA-1101T). Aspects of the annotated full genome of Alkalilimnicola ehrlichii are discussed in the light of its physiology. ?? 2007 IUMS.

Vermicomposting of source-separated human faeces by Eisenia fetida: effect of stocking density on feed consumption rate, growth characteristics and vermicompost production.

PubMed

Yadav, Kunwar D; Tare, Vinod; Ahammed, M Mansoor

2011-06-01

The main objective of the present study was to determine the optimum stocking density for feed consumption rate, biomass growth and reproduction of earthworm Eisenia fetida as well as determining and characterising vermicompost quantity and product, respectively, during vermicomposting of source-separated human faeces. For this, a number of experiments spanning up to 3 months were conducted using soil and vermicompost as support materials. Stocking density in the range of 0.25-5.00 kg/m(2) was employed in different tests. The results showed that 0.40-0.45 kg-feed/kg-worm/day was the maximum feed consumption rate by E. fetida in human faeces. The optimum stocking densities were 3.00 kg/m(2) for bioconversion of human faeces to vermicompost, and 0.50 kg/m(2) for earthworm biomass growth and reproduction. Copyright © 2011 Elsevier Ltd. All rights reserved.

The importance of measuring growth in response to intervention models: Testing a core assumption✩

PubMed Central

Schatschneider, Christopher; Wagner, Richard K.; Crawford, Elizabeth C.

2011-01-01

A core assumption of response to instruction or intervention (RTI) models is the importance of measuring growth in achievement over time in response to effective instruction or intervention. Many RTI models actively monitor growth for identifying individuals who need different levels of intervention. A large-scale (N=23,438), two-year longitudinal study of first grade children was carried out to compare the predictive validity of measures of achievement status, growth in achievement, and their combination for predicting future reading achievement. The results indicate that under typical conditions, measures of growth do not make a contribution to prediction that is independent of measures of achievement status. These results question the validity of a core assumption of RTI models. PMID:22224065

Exergy analysis of hybrid nanofluids with optimum concentration in a plate heat exchanger

NASA Astrophysics Data System (ADS)

Kumar, Vikas; Tiwari, Arun Kumar; Ghosh, Subrata Kumar

2018-06-01

This paper highlights an investigation on the comparative analyses of exergetic performance with optimum volume concentration of hybrid nanofluids in a plate heat exchanger (PHE). Different types of hybrid nanofluids (Al2O3 + MWCNT/water, TiO2 + MWCNT/water, ZnO + MWCNT/water, and CeO2 + MWCNT/water) as coolant have been tested. Proportion of 0.75% of nanofluid has been found to be the optimum volume concentration. The requisite thermal and physical properties of the hybrid nanofluids were measured at 35 °C. Various exergetic performance parameters have been examined for comparing different hybrid nanofluids. The highest reduction in exergy loss of CeO2 + MWCNT/water hybrid nanofluid has been obtained at a concentration of about 24.75%. Entropy generation decreased with the increase in volume concentration. The results established that CeO2 + MWCNT/water hybrid nanofluid can be a promising coolant for exergetic performances in a PHE.

Achieving a competitive advantage in managed care.

PubMed

Stahl, D A

1998-02-01

When building a competitive advantage to thrive in the managed care arena, subacute care providers are urged to be revolutionary rather than reactionary, proactive rather than passive, optimistic rather than pessimistic and growth-oriented rather than cost-reduction oriented. Weaknesses must be addressed aggressively. To achieve a competitive edge, assess the facility's strengths, understand the marketplace and comprehend key payment methods.

The Impact of Ready Environments on Achievement in Kindergarten

ERIC Educational Resources Information Center

Nelson, Regena Fails

2005-01-01

The purpose of this study was to examine how young children's homes and preschool programs influence kindergarten achievement by being "ready environments." Ready environments provide opportunities for cognitive and social growth through culturally and developmentally appropriate activities, interactions, and materials. This study used…

Optimum data analysis procedures for Titan 4 and Space Shuttle payload acoustic measurements during lift-off

NASA Technical Reports Server (NTRS)

Piersol, Allan G.

1991-01-01

Analytical expressions have been derived to describe the mean square error in the estimation of the maximum rms value computed from a step-wise (or running) time average of a nonstationary random signal. These analytical expressions have been applied to the problem of selecting the optimum averaging times that will minimize the total mean square errors in estimates of the maximum sound pressure levels measured inside the Titan IV payload fairing (PLF) and the Space Shuttle payload bay (PLB) during lift-off. Based on evaluations of typical Titan IV and Space Shuttle launch data, it has been determined that the optimum averaging times for computing the maximum levels are (1) T (sub o) = 1.14 sec for the maximum overall level, and T(sub oi) = 4.88 f (sub i) (exp -0.2) sec for the maximum 1/3 octave band levels inside the Titan IV PLF, and (2) T (sub o) = 1.65 sec for the maximum overall level, and T (sub oi) = 7.10 f (sub i) (exp -0.2) sec for the maximum 1/3 octave band levels inside the Space Shuttle PLB, where f (sub i) is the 1/3 octave band center frequency. However, the results for both vehicles indicate that the total rms error in the maximum level estimates will be within 25 percent the minimum error for all averaging times within plus or minus 50 percent of the optimum averaging time, so a precise selection of the exact optimum averaging time is not critical. Based on these results, linear averaging times (T) are recommended for computing the maximum sound pressure level during lift-off.

Growth and change in attention problems, disruptive behavior, and achievement from kindergarten to fifth grade.

PubMed

Claessens, Amy; Dowsett, Chantelle

2014-12-01

Despite widespread interest in children's adjustment problems, existing research does not provide conclusive evidence regarding the direction of the associations of achievement with classroom attention problems and disruptive behavior over the course of elementary school. Using a nationally representative sample of 16,260 kindergarteners, this study examined the temporal sequence of achievement, classroom attention problems, and disruptive behavior, focusing on how changes in skills and problems unfold across key periods between kindergarten and fifth grade. Results indicate that improvements in attention during the earliest years of schooling predict achievement gains through third grade. However, changes in disruptive behavior do not predict subsequent changes in achievement. Evidence linking changes in achievement to changes in classroom attention problems and disruptive behavior was less consistent. These findings point to the need to develop and examine early interventions that can improve attention skills as a mechanism for improving children's academic trajectories in elementary school. © The Author(s) 2014.

Income-related children's health inequality and health achievement in China.

PubMed

Chen, Lu; Wu, Ya; Coyte, Peter C

2014-10-29

This study assessed income-related health inequality and health achievement in children in China, and additionally, examined province-level variations in health achievement. Longitudinal data on 19,801 children under 18 years of age were derived from the China Health and Nutrition Survey. Income-related health inequality and health achievement were measured by the Health Concentration and Health Achievement Indices, respectively. Panel data with a fixed effect multiple regression model was employed to examine province-level variations in health achievement. A growing trend was towards greater health inequality among Chinese children over the last two decades. Although health achievement was getting better over time, the pro-rich inequality component has lessened the associated gain in achievement. Health achievement was positively impacted by middle school enrollments, the urbanization rate, inflation-adjusted per capita gross domestic product, and per capita public health spending. This study has provided evidence that average health status of Chinese children has improved, but inequality has widened. Widening inequality slowed the growth in health achievement for children over time. There were wide variations in health achievement throughout China.

Optimum Platinum Loading In Pt/SnO2 CO-Oxidizing Catalysts

NASA Technical Reports Server (NTRS)

Schryer, David R.; Upchurch, Billy T.; Davis, Patricia P.; Brown, Kenneth G.; Schryer, Jacqueline

1991-01-01

Platinum on tin oxide (Pt/SnO2) good catalyst for oxidation of carbon monoxide at or near room temperature. Catalytic activity peaks at about 17 weight percent Pt. Catalysts with platinum loadings as high as 46 percent fabricated by technique developed at Langley Research Center. Work conducted to determine optimum platinum loading for this type of catalyst. Major application is removal of unwanted CO and O2 in CO2 lasers.

Optimum structural sizing of conventional cantilever and joined wing configurations using equivalent beam models

NASA Technical Reports Server (NTRS)

Hajela, P.; Chen, J. L.

1986-01-01

The present paper describes an approach for the optimum sizing of single and joined wing structures that is based on representing the built-up finite element model of the structure by an equivalent beam model. The low order beam model is computationally more efficient in an environment that requires repetitive analysis of several trial designs. The design procedure is implemented in a computer program that requires geometry and loading data typically available from an aerodynamic synthesis program, to create the finite element model of the lifting surface and an equivalent beam model. A fully stressed design procedure is used to obtain rapid estimates of the optimum structural weight for the beam model for a given geometry, and a qualitative description of the material distribution over the wing structure. The synthesis procedure is demonstrated for representative single wing and joined wing structures.

Residual Gases in Crystal Growth Systems

NASA Technical Reports Server (NTRS)

Palosz, W.

2003-01-01

Residual gases present in closed ampoules may affect different crystal growth processes. That seems to be particularly true under microgravity conditions where, due to weightlessness of the melt, the gases may lead to detached solidification and/or formation of voids and bubbles, as observed in the past. For that reason a good understanding and control of formation of residual gases is important for an optimum design and meaningful interpretation of crystal growth experiments. Our extensive experimental and theoretical studies of the subject, summarized in this paper, include degassing of silica glass and generation of gases from different source materials. Different materials processing conditions, like outgassing under vacuum, annealing in hydrogen, resublimation, different material preparation procedures, multiple annealings, different processing times, and others were applied and their effect on the amount and composition of gas were analyzed. The experimental results were interpreted based on theoretical calculations on diffusion in silica glass and source materials and thermochemistry of the system. Procedures for a reduction of the amount of gas are also discussed.

Optimization of growth for the hyperthermophilic archaeon Aeropyrum pernix on a small-batch scale.

PubMed

Milek, Igor; Cigic, Blaz; Skrt, Mihaela; Kaletunç, Gönül; Ulrih, Natasa Poklar

2005-09-01

Growth of Aeropyrum pernix, the first reported aerobic neutrophilic hyperthermophilic archaeon, was investigated under different cultivation parameters. Different sources of seawater, pH, and the cultivation methods were tested with the aim to improve the biomass production. A 1-L glass flask fitted with a condenser and air diffuser was used as a bioreactor. The optimum conditions for maximizing A. pernix biomass were obtained when Na2S2O3.5H2O (1 g/L) with added marine broth 2216 at pH 7.0 (20 mmol HEPES buffer/L) was used as a growing medium in a 1-L flask. The biomass production was 0.45 g dry cell mass/L in 40 h under the optimum conditions, which is more than the 0.42 g dry cell mass/L in 60 h previously obtained.

Improved Radiative Control of Ribbon Growth

NASA Technical Reports Server (NTRS)

Mchugh, J. P.; Seidensticker, R. G.; Skutch, M. E.

1984-01-01

Shield modifications enhance growth rate while reducing silicon oxide formation. Control of dendritic-web crystal growth requires precise control of web temperature profile. Achieved by using series of thermal radiation shields to control thermal-radiation field in region where melt solidifying onto crystal ribbon being pulled from melt.

Logistical constraints lead to an intermediate optimum in outbreak response vaccination

PubMed Central

Shea, Katriona; Ferrari, Matthew

2018-01-01

Dynamic models in disease ecology have historically evaluated vaccination strategies under the assumption that they are implemented homogeneously in space and time. However, this approach fails to formally account for operational and logistical constraints inherent in the distribution of vaccination to the population at risk. Thus, feedback between the dynamic processes of vaccine distribution and transmission might be overlooked. Here, we present a spatially explicit, stochastic Susceptible-Infected-Recovered-Vaccinated model that highlights the density-dependence and spatial constraints of various diffusive strategies of vaccination during an outbreak. The model integrates an agent-based process of disease spread with a partial differential process of vaccination deployment. We characterize the vaccination response in terms of a diffusion rate that describes the distribution of vaccination to the population at risk from a central location. This generates an explicit trade-off between slow diffusion, which concentrates effort near the central location, and fast diffusion, which spreads a fixed vaccination effort thinly over a large area. We use stochastic simulation to identify the optimum vaccination diffusion rate as a function of population density, interaction scale, transmissibility, and vaccine intensity. Our results show that, conditional on a timely response, the optimal strategy for minimizing outbreak size is to distribute vaccination resource at an intermediate rate: fast enough to outpace the epidemic, but slow enough to achieve local herd immunity. If the response is delayed, however, the optimal strategy for minimizing outbreak size changes to a rapidly diffusive distribution of vaccination effort. The latter may also result in significantly larger outbreaks, thus suggesting a benefit of allocating resources to timely outbreak detection and response. PMID:29791432

Influence of nitrogen and phosphorous on the growth and root morphology of Acer mono

PubMed Central

Zhang, Peng; Shen, Hai-long; Salahuddin

2017-01-01

Nitrogen and phosphorous are critical determinants of plant growth and productivity, and both plant growth and root morphology are important parameters for evaluating the effects of supplied nutrients. Previous work has shown that the growth of Acer mono seedlings is retarded under nursery conditions; we applied different levels of N (0, 5, 10, and 15 g plant-1) and P (0, 4, 6 and 8 g plant-1) fertilizer to investigate the effects of fertilization on the growth and root morphology of four-year-old seedlings in the field. Our results indicated that both N and P application significantly affected plant height, root collar diameter, chlorophyll content, and root morphology. Among the nutrient levels, 10 g N and 8 g P were found to yield maximum growth, and the maximum values of plant height, root collar diameter, chlorophyll content, and root morphology were obtained when 10 g N and 8 g P were used together. Therefore, the present study demonstrates that optimum levels of N and P can be used to improve seedling health and growth during the nursery period. PMID:28234921

Optimum coding techniques for MST radars

NASA Technical Reports Server (NTRS)

Sulzer, M. P.; Woodman, R. F.

1986-01-01

The optimum coding technique for MST (mesosphere stratosphere troposphere) radars is that which gives the lowest possible sidelobes in practice and can be implemented without too much computing power. Coding techniques are described in Farley (1985). A technique mentioned briefly there but not fully developed and not in general use is discussed here. This is decoding by means of a filter which is not matched to the transmitted waveform, in order to reduce sidelobes below the level obtained with a matched filter. This is the first part of the technique discussed here; the second part consists of measuring the transmitted waveform and using it as the basis for the decoding filter, thus reducing errors due to imperfections in the transmitter. There are two limitations to this technique. The first is a small loss in signal to noise ratio (SNR), which usually is not significant. The second problem is related to incomplete information received at the lowest ranges. An appendix shows a technique for handling this problem. Finally, it is shown that the use of complementary codes on transmission and nonmatched decoding gives the lowest possible sidelobe level and the minimum loss in SNR due to mismatch.

Hispanic Students' Mathematics Achievement in the Context of Their High School Types as STEM and Non-STEM Schools

ERIC Educational Resources Information Center

Bicer, Ali; Capraro, Robert M.; Capraro, Mary M.

2018-01-01

The purpose of this paper is to demonstrate Hispanic students' mathematics achievement growth rate in Inclusive science, technology, engineering, and mathematics (STEM) high schools compared to Hispanic students' mathematics achievement growth rate in traditional public schools. Twenty-eight schools, 14 of which were Texas STEM (T-STEM) academies…

Ambient and elevated carbon dioxide on growth, physiological and nutrient uptake parameters of perennial leguminous cover crops under low light intensities

USDA-ARS?s Scientific Manuscript database

Adaptability and optimum growth of cover crops in plantation crops is affected by the inherent nature of the cover crop species and the light intensity at canopy levels. Globally concentrations of atmospheric CO2 are increasing and this creates higher photosynthesis and nutrient demand by crops as l...

Optimum Temperatures for Net Primary Productivity of Three Tropical Seagrass Species

PubMed Central

Collier, Catherine J.; Ow, Yan X.; Langlois, Lucas; Uthicke, Sven; Johansson, Charlotte L.; O'Brien, Katherine R.; Hrebien, Victoria; Adams, Matthew P.

2017-01-01

Rising sea water temperature will play a significant role in responses of the world's seagrass meadows to climate change. In this study, we investigated seasonal and latitudinal variation (spanning more than 1,500 km) in seagrass productivity, and the optimum temperatures at which maximum photosynthesis and net productivity (for the leaf and the whole plant) occurs, for three seagrass species (Cymodocea serrulata, Halodule uninervis, and Zostera muelleri). To obtain whole plant net production, photosynthesis, and respiration rates of leaves and the root/rhizome complex were measured using oxygen-sensitive optodes in closed incubation chambers at temperatures ranging from 15 to 43°C. The temperature-dependence of photosynthesis and respiration was fitted to empirical models to obtain maximum metabolic rates and thermal optima. The thermal optimum (Topt) for gross photosynthesis of Z. muelleri, which is more commonly distributed in sub-tropical to temperate regions, was 31°C. The Topt for photosynthesis of the tropical species, H. uninervis and C. serrulata, was considerably higher (35°C on average). This suggests that seagrass species are adapted to water temperature within their distributional range; however, when comparing among latitudes and seasons, thermal optima within a species showed limited acclimation to ambient water temperature (Topt varied by 1°C in C. serrulata and 2°C in H. uninervis, and the variation did not follow changes in ambient water temperature). The Topt for gross photosynthesis were higher than Topt calculated from plant net productivity, which includes above- and below-ground respiration for Z. muelleri (24°C) and H. uninervis (33°C), but remained unchanged at 35°C in C. serrulata. Both estimated plant net productivity and Topt are sensitive to the proportion of below-ground biomass, highlighting the need for consideration of below- to above-ground biomass ratios when applying thermal optima to other meadows. The thermal optimum

Population growth and economic growth.

PubMed

Narayana, D L

1984-01-01

the exponential growth of population as the source of several complications for economic growth and human welfare. Stabilization of population by reducing fertility is conducive for improving the quality of population and also advances the longterm management of the population growth and work force utilization. The perspective of longterm economic management involves populatio n planning, control of environmental pollution, conservation of scarce resources, exploration of resources, realization of technological possibilities in agriculture and industry and in farm and factory, and achievement of economic growth and its equitable distribution.

Individualism, innovation, and long-run growth.

PubMed

Gorodnichenko, Yuriy; Roland, Gerard

2011-12-27

Countries having a more individualist culture have enjoyed higher long-run growth than countries with a more collectivist culture. Individualist culture attaches social status rewards to personal achievements and thus, provides not only monetary incentives for innovation but also social status rewards, leading to higher rates of innovation and economic growth.

Zeolite crystal growth in space - What has been learned

NASA Technical Reports Server (NTRS)

Sacco, A., Jr.; Thompson, R. W.; Dixon, A. G.

1993-01-01

Three zeolite crystal growth experiments developed at WPI have been performed in space in last twelve months. One experiment, GAS-1, illustrated that to grow large, crystallographically uniform crystals in space, the precursor solutions should be mixed in microgravity. Another experiment evaluated the optimum mixing protocol for solutions that chemically interact ('gel') on contact. These results were utilized in setting the protocol for mixing nineteen zeolite solutions that were then processed and yielded zeolites A, X and mordenite. All solutions in which the nucleation event was influenced produced larger, more 'uniform' crystals than did identical solutions processed on earth.

Effects of growth hormone treatment on growth in children with juvenile idiopathic arthritis.

PubMed

Simon, D; Bechtold, S

2009-11-01

Several therapeutic trials have been conducted over the past decade to evaluate the role of exogenous growth hormone (GH) as a means of correcting the growth deficiency seen in children with juvenile idiopathic arthritis (JIA). Early studies showed the benefit of GH treatment with respect to final height in patients with JIA. Of 13 patients receiving GH, 84% (11 patients) achieved a final height within their target range compared with only 22% (4 of 18 patients) of untreated patients. There are, however, factors that may limit the statural gains achieved with GH therapy including severe inflammation, severe statural deficiency at GH therapy initiation, long disease duration and delayed puberty. Data on the efficacy of GH replacement therapy in children with JIA and factors that influence the statural growth response will be reviewed. Results from therapeutic trials show that treatment with GH can decrease the statural deficit that occurs during the active phase of JIA, producing an adult height that is close to the genetically determined target height. Copyright 2009 S. Karger AG, Basel.

Predicting Children's Reading and Mathematics Achievement from Early Quantitative Knowledge and Domain-General Cognitive Abilities

PubMed Central

Chu, Felicia W.; vanMarle, Kristy; Geary, David C.

2016-01-01

One hundred children (44 boys) participated in a 3-year longitudinal study of the development of basic quantitative competencies and the relation between these competencies and later mathematics and reading achievement. The children's preliteracy knowledge, intelligence, executive functions, and parental educational background were also assessed. The quantitative tasks assessed a broad range of symbolic and nonsymbolic knowledge and were administered four times across 2 years of preschool. Mathematics achievement was assessed at the end of each of 2 years of preschool, and mathematics and word reading achievement were assessed at the end of kindergarten. Our goals were to determine how domain-general abilities contribute to growth in children's quantitative knowledge and to determine how domain-general and domain-specific abilities contribute to children's preschool mathematics achievement and kindergarten mathematics and reading achievement. We first identified four core quantitative competencies (e.g., knowledge of the cardinal value of number words) that predict later mathematics achievement. The domain-general abilities were then used to predict growth in these competencies across 2 years of preschool, and the combination of domain-general abilities, preliteracy skills, and core quantitative competencies were used to predict mathematics achievement across preschool and mathematics and word reading achievement at the end of kindergarten. Both intelligence and executive functions predicted growth in the four quantitative competencies, especially across the first year of preschool. A combination of domain-general and domain-specific competencies predicted preschoolers' mathematics achievement, with a trend for domain-specific skills to be more strongly related to achievement at the beginning of preschool than at the end of preschool. Preschool preliteracy skills, sensitivity to the relative quantities of collections of objects, and cardinal knowledge predicted

Predicting Children's Reading and Mathematics Achievement from Early Quantitative Knowledge and Domain-General Cognitive Abilities.

PubMed

Chu, Felicia W; vanMarle, Kristy; Geary, David C

2016-01-01

One hundred children (44 boys) participated in a 3-year longitudinal study of the development of basic quantitative competencies and the relation between these competencies and later mathematics and reading achievement. The children's preliteracy knowledge, intelligence, executive functions, and parental educational background were also assessed. The quantitative tasks assessed a broad range of symbolic and nonsymbolic knowledge and were administered four times across 2 years of preschool. Mathematics achievement was assessed at the end of each of 2 years of preschool, and mathematics and word reading achievement were assessed at the end of kindergarten. Our goals were to determine how domain-general abilities contribute to growth in children's quantitative knowledge and to determine how domain-general and domain-specific abilities contribute to children's preschool mathematics achievement and kindergarten mathematics and reading achievement. We first identified four core quantitative competencies (e.g., knowledge of the cardinal value of number words) that predict later mathematics achievement. The domain-general abilities were then used to predict growth in these competencies across 2 years of preschool, and the combination of domain-general abilities, preliteracy skills, and core quantitative competencies were used to predict mathematics achievement across preschool and mathematics and word reading achievement at the end of kindergarten. Both intelligence and executive functions predicted growth in the four quantitative competencies, especially across the first year of preschool. A combination of domain-general and domain-specific competencies predicted preschoolers' mathematics achievement, with a trend for domain-specific skills to be more strongly related to achievement at the beginning of preschool than at the end of preschool. Preschool preliteracy skills, sensitivity to the relative quantities of collections of objects, and cardinal knowledge predicted

High‐Performance Lithium‐Oxygen Battery Electrolyte Derived from Optimum Combination of Solvent and Lithium Salt

PubMed Central

Ahn, Su Mi; Suk, Jungdon; Kim, Do Youb; Kim, Hwan Kyu

2017-01-01

Abstract To fabricate a sustainable lithium‐oxygen (Li‐O2) battery, it is crucial to identify an optimum electrolyte. Herein, it is found that tetramethylene sulfone (TMS) and lithium nitrate (LiNO3) form the optimum electrolyte, which greatly reduces the overpotential at charge, exhibits superior oxygen efficiency, and allows stable cycling for 100 cycles. Linear sweep voltammetry (LSV) and differential electrochemical mass spectrometry (DEMS) analyses reveal that neat TMS is stable to oxidative decomposition and exhibit good compatibility with a lithium metal. But, when TMS is combined with typical lithium salts, its performance is far from satisfactory. However, the TMS electrolyte containing LiNO3 exhibits a very low overpotential, which minimizes the side reactions and shows high oxygen efficiency. LSV‐DEMS study confirms that the TMS‐LiNO3 electrolyte efficiently produces NO2 −, which initiates a redox shuttle reaction. Interestingly, this NO2 −/NO2 redox reaction derived from the LiNO3 salt is not very effective in solvents other than TMS. Compared with other common Li‐O2 solvents, TMS seems optimum solvent for the efficient use of LiNO3 salt. Good compatibility with lithium metal, high dielectric constant, and low donicity of TMS are considered to be highly favorable to an efficient NO2 −/NO2 redox reaction, which results in a high‐performance Li‐O2 battery. PMID:29051863

High-Performance Lithium-Oxygen Battery Electrolyte Derived from Optimum Combination of Solvent and Lithium Salt.

PubMed

Ahn, Su Mi; Suk, Jungdon; Kim, Do Youb; Kang, Yongku; Kim, Hwan Kyu; Kim, Dong Wook

2017-10-01

To fabricate a sustainable lithium-oxygen (Li-O 2 ) battery, it is crucial to identify an optimum electrolyte. Herein, it is found that tetramethylene sulfone (TMS) and lithium nitrate (LiNO 3 ) form the optimum electrolyte, which greatly reduces the overpotential at charge, exhibits superior oxygen efficiency, and allows stable cycling for 100 cycles. Linear sweep voltammetry (LSV) and differential electrochemical mass spectrometry (DEMS) analyses reveal that neat TMS is stable to oxidative decomposition and exhibit good compatibility with a lithium metal. But, when TMS is combined with typical lithium salts, its performance is far from satisfactory. However, the TMS electrolyte containing LiNO 3 exhibits a very low overpotential, which minimizes the side reactions and shows high oxygen efficiency. LSV-DEMS study confirms that the TMS-LiNO 3 electrolyte efficiently produces NO 2 - , which initiates a redox shuttle reaction. Interestingly, this NO 2 - /NO 2 redox reaction derived from the LiNO 3 salt is not very effective in solvents other than TMS. Compared with other common Li-O 2 solvents, TMS seems optimum solvent for the efficient use of LiNO 3 salt. Good compatibility with lithium metal, high dielectric constant, and low donicity of TMS are considered to be highly favorable to an efficient NO 2 - /NO 2 redox reaction, which results in a high-performance Li-O 2 battery.

Optimum stacking sequence design of laminated composite circular plates with curvilinear fibres by a layer-wise optimization method

NASA Astrophysics Data System (ADS)

Guenanou, A.; Houmat, A.

2018-05-01

The optimum stacking sequence design for the maximum fundamental frequency of symmetrically laminated composite circular plates with curvilinear fibres is investigated for the first time using a layer-wise optimization method. The design variables are two fibre orientation angles per layer. The fibre paths are constructed using the method of shifted paths. The first-order shear deformation plate theory and a curved square p-element are used to calculate the objective function. The blending function method is used to model accurately the geometry of the circular plate. The equations of motion are derived using Lagrange's method. The numerical results are validated by means of a convergence test and comparison with published values for symmetrically laminated composite circular plates with rectilinear fibres. The material parameters, boundary conditions, number of layers and thickness are shown to influence the optimum solutions to different extents. The results should serve as a benchmark for optimum stacking sequences of symmetrically laminated composite circular plates with curvilinear fibres.

Design of slurry bubble column reactors: novel technique for optimum catalyst size selection contractual origin of the invention

DOEpatents

Gamwo, Isaac K [Murrysville, PA; Gidaspow, Dimitri [Northbrook, IL; Jung, Jonghwun [Naperville, IL

2009-11-17

A method for determining optimum catalyst particle size for a gas-solid, liquid-solid, or gas-liquid-solid fluidized bed reactor such as a slurry bubble column reactor (SBCR) for converting synthesis gas into liquid fuels considers the complete granular temperature balance based on the kinetic theory of granular flow, the effect of a volumetric mass transfer coefficient between the liquid and the gas, and the water gas shift reaction. The granular temperature of the catalyst particles representing the kinetic energy of the catalyst particles is measured and the volumetric mass transfer coefficient between the gas and liquid phases is calculated using the granular temperature. Catalyst particle size is varied from 20 .mu.m to 120 .mu.m and a maximum mass transfer coefficient corresponding to optimum liquid hydrocarbon fuel production is determined. Optimum catalyst particle size for maximum methanol production in a SBCR was determined to be in the range of 60-70 .mu.m.

Determination of optimum threshold values for EMG time domain features; a multi-dataset investigation

NASA Astrophysics Data System (ADS)

Nlandu Kamavuako, Ernest; Scheme, Erik Justin; Englehart, Kevin Brian

2016-08-01

Objective. For over two decades, Hudgins’ set of time domain features have extensively been applied for classification of hand motions. The calculation of slope sign change and zero crossing features uses a threshold to attenuate the effect of background noise. However, there is no consensus on the optimum threshold value. In this study, we investigate for the first time the effect of threshold selection on the feature space and classification accuracy using multiple datasets. Approach. In the first part, four datasets were used, and classification error (CE), separability index, scatter matrix separability criterion, and cardinality of the features were used as performance measures. In the second part, data from eight classes were collected during two separate days with two days in between from eight able-bodied subjects. The threshold for each feature was computed as a factor (R = 0:0.01:4) times the average root mean square of data during rest. For each day, we quantified CE for R = 0 (CEr0) and minimum error (CEbest). Moreover, a cross day threshold validation was applied where, for example, CE of day two (CEodt) is computed based on optimum threshold from day one and vice versa. Finally, we quantified the effect of the threshold when using training data from one day and test data of the other. Main results. All performance metrics generally degraded with increasing threshold values. On average, CEbest (5.26 ± 2.42%) was significantly better than CEr0 (7.51 ± 2.41%, P = 0.018), and CEodt (7.50 ± 2.50%, P = 0.021). During the two-fold validation between days, CEbest performed similar to CEr0. Interestingly, when using the threshold values optimized per subject from day one and day two respectively, on the cross-days classification, the performance decreased. Significance. We have demonstrated that threshold value has a strong impact on the feature space and that an optimum threshold can be quantified. However, this optimum threshold is highly data and

Determination of the Optimum Harvest Window for Apples Using the Non-Destructive Biospeckle Method.

PubMed

Skic, Anna; Szymańska-Chargot, Monika; Kruk, Beata; Chylińska, Monika; Pieczywek, Piotr Mariusz; Kurenda, Andrzej; Zdunek, Artur; Rutkowski, Krzysztof P

2016-05-10

Determination of the optimum harvest window plays a key role in the agro-food chain as the quality of fruit depends on the right harvesting time and appropriate storage conditions during the postharvest period. Usually, indices based on destructive measurements are used for this purpose, like the De Jager Index (PFW-1), FARS index and the most popular Streif Index. In this study, we proposed a biospeckle method for the evaluation of the optimum harvest window (OHW) of the "Ligol" and "Szampion" apple cultivars. The experiment involved eight different maturity stages, of which four were followed by long cold storage and shelf life to assist the determination of the optimum harvest window. The biospeckle activity was studied in relation to standard quality attributes (firmness, acidity, starch, soluble solids content, Streif Index) and physiological parameters (respiration and ethylene emission) of both apple cultivars. Changes of biospeckle activity (BA) over time showed moderate relationships with biochemical changes during apple maturation and ripening. The harvest date suggested by the Streif Index and postharvest quality indicators matched with characteristic decrease in BA. The ability of biospeckle method to characterize the biological state of apples was confirmed by significant correlations of BA with firmness, starch index, total soluble solids and Streif Index, as well as good match with changes in carbon dioxide and ethylene emission. However, it should be noted that correlations between variables changing over time are not as meaningful as independent observations. Also, it is a well-known property of the Pearson's correlation that its value is highly susceptible to outlier data. Due to its non-selective nature the BA reflected only the current biological state of the fruit and could be affected by many other factors. The investigations showed that the optimum harvest window for apples was indicated by the characteristic drop of BA during pre

Determination of the Optimum Harvest Window for Apples Using the Non-Destructive Biospeckle Method

PubMed Central

Skic, Anna; Szymańska-Chargot, Monika; Kruk, Beata; Chylińska, Monika; Pieczywek, Piotr Mariusz; Kurenda, Andrzej; Zdunek, Artur; Rutkowski, Krzysztof P.

2016-01-01

Determination of the optimum harvest window plays a key role in the agro-food chain as the quality of fruit depends on the right harvesting time and appropriate storage conditions during the postharvest period. Usually, indices based on destructive measurements are used for this purpose, like the De Jager Index (PFW-1), FARS index and the most popular Streif Index. In this study, we proposed a biospeckle method for the evaluation of the optimum harvest window (OHW) of the “Ligol” and “Szampion” apple cultivars. The experiment involved eight different maturity stages, of which four were followed by long cold storage and shelf life to assist the determination of the optimum harvest window. The biospeckle activity was studied in relation to standard quality attributes (firmness, acidity, starch, soluble solids content, Streif Index) and physiological parameters (respiration and ethylene emission) of both apple cultivars. Changes of biospeckle activity (BA) over time showed moderate relationships with biochemical changes during apple maturation and ripening. The harvest date suggested by the Streif Index and postharvest quality indicators matched with characteristic decrease in BA. The ability of biospeckle method to characterize the biological state of apples was confirmed by significant correlations of BA with firmness, starch index, total soluble solids and Streif Index, as well as good match with changes in carbon dioxide and ethylene emission. However, it should be noted that correlations between variables changing over time are not as meaningful as independent observations. Also, it is a well-known property of the Pearson’s correlation that its value is highly susceptible to outlier data. Due to its non-selective nature the BA reflected only the current biological state of the fruit and could be affected by many other factors. The investigations showed that the optimum harvest window for apples was indicated by the characteristic drop of BA during pre

Determination of optimum threshold values for EMG time domain features; a multi-dataset investigation.

PubMed

Kamavuako, Ernest Nlandu; Scheme, Erik Justin; Englehart, Kevin Brian

2016-08-01

For over two decades, Hudgins' set of time domain features have extensively been applied for classification of hand motions. The calculation of slope sign change and zero crossing features uses a threshold to attenuate the effect of background noise. However, there is no consensus on the optimum threshold value. In this study, we investigate for the first time the effect of threshold selection on the feature space and classification accuracy using multiple datasets. In the first part, four datasets were used, and classification error (CE), separability index, scatter matrix separability criterion, and cardinality of the features were used as performance measures. In the second part, data from eight classes were collected during two separate days with two days in between from eight able-bodied subjects. The threshold for each feature was computed as a factor (R = 0:0.01:4) times the average root mean square of data during rest. For each day, we quantified CE for R = 0 (CEr0) and minimum error (CEbest). Moreover, a cross day threshold validation was applied where, for example, CE of day two (CEodt) is computed based on optimum threshold from day one and vice versa. Finally, we quantified the effect of the threshold when using training data from one day and test data of the other. All performance metrics generally degraded with increasing threshold values. On average, CEbest (5.26 ± 2.42%) was significantly better than CEr0 (7.51 ± 2.41%, P = 0.018), and CEodt (7.50 ± 2.50%, P = 0.021). During the two-fold validation between days, CEbest performed similar to CEr0. Interestingly, when using the threshold values optimized per subject from day one and day two respectively, on the cross-days classification, the performance decreased. We have demonstrated that threshold value has a strong impact on the feature space and that an optimum threshold can be quantified. However, this optimum threshold is highly data and subject driven and thus do not generalize

Shade, leaf growth, and crown development of Quercus rubra, Q. velutina, Prunus serotina, and Acer rubrum seedlings

Treesearch

Kurt W. Gottschalk

1994-01-01

The study was conducted in an open field to detennine the optimum irradiance for establishment and growth of two oak species and two major associated woody species. Half-sib seedlings of black cherry (Prunus serotina Ehrh.), red maple (Acer rubrum L.), northern red oak (Quercus rubra L.) and black oak (Q. velutina Lam.) were grown for two years under shade-clotht...

An Optimum Specimen Geometry for Equibiaxial Experimental Tests of Reinforced Magnetorheological Elastomers with Iron Micro- and Nanoparticles

PubMed Central

Perales-Martínez, Imperio Anel; Moreno-Guerra, Mario Regino; Elías-Zúñiga, Alex

2017-01-01

The aim of this paper focused on obtaining the optimum cruciform geometry of reinforced magnetorheological elastomers (MRE) to perform homogeneous equibiaxial deformation tests, by using optimization algorithms and Finite Element Method (FEM) simulations. To validate the proposed specimen geometry, a digital image correlation (DIC) system was used to compare experimental result measurements with respect to those of FEM simulations. Moreover, and based on the optimum cruciform geometry, specimens produced from MRE reinforced with carbonyl-iron microparticles or iron nanoparticles were subjected to equibiaxial loading and unloading cycles to examine their Mullin’s effect and their residual strain deformations. PMID:28869523

An Optimum Specimen Geometry for Equibiaxial Experimental Tests of Reinforced Magnetorheological Elastomers with Iron Micro- and Nanoparticles.

PubMed

Palacios-Pineda, Luis Manuel; Perales-Martínez, Imperio Anel; Moreno-Guerra, Mario Regino; Elías-Zúñiga, Alex

2017-09-03

The aim of this paper focused on obtaining the optimum cruciform geometry of reinforced magnetorheological elastomers (MRE) to perform homogeneous equibiaxial deformation tests, by using optimization algorithms and Finite Element Method (FEM) simulations. To validate the proposed specimen geometry, a digital image correlation (DIC) system was used to compare experimental result measurements with respect to those of FEM simulations. Moreover, and based on the optimum cruciform geometry, specimens produced from MRE reinforced with carbonyl-iron microparticles or iron nanoparticles were subjected to equibiaxial loading and unloading cycles to examine their Mullin's effect and their residual strain deformations.

Survival analysis: A consumer-friendly method to estimate the optimum sucrose level in probiotic petit suisse.

PubMed

Esmerino, E A; Paixão, J A; Cruz, A G; Garitta, L; Hough, G; Bolini, H M A

2015-11-01

For years, just-about-right (JAR) scales have been among the most used techniques to obtain sensory information about consumer perception, but recently, some researchers have harshly criticized the technique. The present study aimed to apply survival analysis to estimate the optimum sucrose concentration in probiotic petit suisse cheese and compare the survival analysis to JAR scales to verify which technique more accurately predicted the optimum sucrose concentration according to consumer acceptability. Two panels of consumers (total=170) performed affective tests to determine the optimal concentration of sucrose in probiotic petit suisse using 2 different methods of analysis: JAR scales (n=85) and survival analysis (n=85). Then an acceptance test was conducted using naïve consumers (n=100) between 18 and 60 yr old, with 2 samples of petit suisse, one with the ideal sucrose determined by JAR scales and the other with the ideal sucrose content determined by survival analysis, to determine which formulation was in accordance with consumer acceptability. The results indicate that the 2 sensory methods were equally effective in predicting the optimum sucrose level in probiotic petit suisse cheese, and no significant differences were detected in any of the characteristics related to liking evaluated. However, survival analysis has important advantages over the JAR scales. Survival analysis has shown the potential to be an advantageous tool for dairy companies because it was able to accurately predict the optimum sucrose content in a consumer-friendly way and was also practical for researchers because experimental sensory work is simpler and has been shown to be more cost effective than JAR scales without losses of consumer acceptability. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Which lamp will be optimum to eye? Incandescent, fluorescent or LED etc

PubMed Central

Chen, Liang; Zhang, Xiao-Wei

2014-01-01

Low frequency flicker, high frequency flicker, strong light, strong blue light, infrared, ultraviolet, electromagnetic radiation, ripple flicker and dimming flicker produced by different lamps have negative impact on vision, eyes and health. Negative impact on eyes resulting in myopia or cataract etc: the solution is to remove all the negative factors by applying upright lighting technology and that is optimum to vision, eyes and health. PMID:24634884

Optimum step design for centering of pistons moving in an incompressible fluid

NASA Technical Reports Server (NTRS)

Etsion, I.; Hamrock, B. J.

1976-01-01

Hydrodynamic effects are analyzed for a stepped piston moving within a tight clearance tube filled with an incompressible fluid. Hydrostatic effects are analyzed and a complete solution is obtained and an optimum step design for centering of the piston is suggested. The axial speed resulting from an axial driving force is calculated, and some experimental results for pistons falling in a water-filled tube are presented.

Which lamp will be optimum to eye? Incandescent, fluorescent or LED etc.

PubMed

Chen, Liang; Zhang, Xiao-Wei

2014-01-01

Low frequency flicker, high frequency flicker, strong light, strong blue light, infrared, ultraviolet, electromagnetic radiation, ripple flicker and dimming flicker produced by different lamps have negative impact on vision, eyes and health. Negative impact on eyes resulting in myopia or cataract etc: the solution is to remove all the negative factors by applying upright lighting technology and that is optimum to vision, eyes and health.

Environmental Effects on Fatigue Crack Growth in High Performance Aluminum Alloys

DTIC Science & Technology

2009-03-13

tested for leaks to a rate of 2x 10൒ cm3/s with helium. All devices connected to the chamber, including pumps , gages and valves, are ultra-high- vacuum ...Pfeiffer TMU-262P), backed by a 5 L/s scroll pump (ULVAC DIS-250). This pump combination eliminates the possibility of contamination by pumping fluid used...both pumps are connected directly to the vacuum chamber to achieve optimum pump -down speeds. Pumping down the chamber is further facilitated by use of

Individualism, innovation, and long-run growth

PubMed Central

Gorodnichenko, Yuriy; Roland, Gerard

2011-01-01

Countries having a more individualist culture have enjoyed higher long-run growth than countries with a more collectivist culture. Individualist culture attaches social status rewards to personal achievements and thus, provides not only monetary incentives for innovation but also social status rewards, leading to higher rates of innovation and economic growth. PMID:22198759

Pattern drilling exploration: Optimum pattern types and hole spacings when searching for elliptical shaped targets

USGS Publications Warehouse

Drew, L.J.

1979-01-01

In this study the selection of the optimum type of drilling pattern to be used when exploring for elliptical shaped targets is examined. The rhombic pattern is optimal when the targets are known to have a preferred orientation. Situations can also be found where a rectangular pattern is as efficient as the rhombic pattern. A triangular or square drilling pattern should be used when the orientations of the targets are unknown. The way in which the optimum hole spacing varies as a function of (1) the cost of drilling, (2) the value of the targets, (3) the shape of the targets, (4) the target occurrence probabilities was determined for several examples. Bayes' rule was used to show how target occurrence probabilities can be revised within a multistage pattern drilling scheme. ?? 1979 Plenum Publishing Corporation.

Achieving Optimal Best: Instructional Efficiency and the Use of Cognitive Load Theory in Mathematical Problem Solving

ERIC Educational Resources Information Center

Phan, Huy P.; Ngu, Bing H.; Yeung, Alexander S.

2017-01-01

We recently developed the "Framework of Achievement Bests" to explain the importance of effective functioning, personal growth, and enrichment of well-being experiences. This framework postulates a concept known as "optimal achievement best," which stipulates the idea that individuals may, in general, strive to achieve personal…

Ten-gram scale SiC@SiO2 nanowires: high-yield synthesis towards industrialization, in situ growth mechanism and their peculiar photoluminescence and electromagnetic wave absorption properties.

PubMed

Li, Z J; Yu, H Y; Song, G Y; Zhao, J; Zhang, H; Zhang, M; Meng, A L; Li, Q D

2017-02-01

SiC@SiO 2 nanowires, as a functional nanocomposite, have attracted widespread attention due to their fascinating performance and broad application prospect. However, the low-cost, high yield preparation of large-scale SiC@SiO 2 nanowires is still a bottleneck, which hinders their industrial application. Herein, a carbothermal reduction strategy has been developed to synthesize SiC@SiO 2 nanowires, which breaks through the handicap of the traditional growth pattern that uses the aid of a substrate. Systematic characterization results illustrate that the yield of the as-obtained products greatly depends on the heating rate, and ten-gram scale SiC@SiO 2 nanowires (∼27.2 g) composed of a cubic β-SiC core and homogeneous amorphous SiO 2 coating are achieved under the optimum process parameters. The in situ mechanisms of expansion-insertion-growth and inhibition of expansion-package-obstruction are proposed to rationally interpret the growth process of SiC@SiO 2 nanowires and the effect of various heating rates, respectively. Furthermore, the SiC@SiO 2 nanowires display violet-blue photoluminescence and electromagnetic wave absorption properties. This study not only provides some beneficial suggestions for the commercial production of SiC@SiO 2 nanowires, but also reveals promising applications of SiC@SiO 2 nanowires in the optical and electromagnetic shielding fields. Moreover, the developed novel in situ growth mechanism enriches the growth theory of one-dimension nanomaterials and offers inspiration for their industrial-scale production.

A literature review on optimum and preferred joint angles in automotive sitting posture.

PubMed

Schmidt, Susanne; Amereller, Maximilian; Franz, Matthias; Kaiser, Ralf; Schwirtz, Ansgar

2014-03-01

In this study, a survey of the scientific literature in the field of optimum and preferred human joint angles in automotive sitting posture was conducted by referring to thirty different sources published between 1940 and today. The strategy was to use only sources with numerical angle data in combination with keywords. The aim of the research was to detect commonly used joint angles in interior car design. The main analysis was on data measurement, usability and comparability of the different studies. In addition, the focus was on the reasons for the differently described results. It was found that there is still a lack of information in methodology and description of background. Due to these reasons published data is not always usable to design a modern ergonomic car environment. As a main result of our literature analysis we suggest undertaking further research in the field of biomechanics and ergonomics to work out scientific based and objectively determined "optimum" joint angles in automotive sitting position. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Desulfonatronum thiodismutans sp. nov., a novel alkaliphilic, sulfate-reducing bacterium capable of lithoautotrophic growth.

PubMed

Pikuta, Elena V; Hoover, Richard B; Bej, Asim K; Marsic, Damien; Whitman, William B; Cleland, David; Krader, Paul

2003-09-01

A novel alkaliphilic, sulfate-reducing bacterium, strain MLF1(T), was isolated from sediments of soda Mono Lake, California. Gram-negative vibrio-shaped cells were observed, which were 0.6-0.7x1.2-2.7 micro m in size, motile by a single polar flagellum and occurred singly, in pairs or as short spirilla. Growth was observed at 15-48 degrees C (optimum, 37 degrees C), >1-7 % NaCl, w/v (optimum, 3 %) and pH 8.0-10.0 (optimum, 9.5). The novel isolate is strictly alkaliphilic, requires a high concentration of carbonate in the growth medium and is obligately anaerobic and catalase-negative. As electron donors, strain MLF1(T) uses hydrogen, formate and ethanol. Sulfate, sulfite and thiosulfate (but not sulfur or nitrate) can be used as electron acceptors. The novel isolate is a lithoheterotroph and a facultative lithoautotroph that is able to grow on hydrogen without an organic source of carbon. Strain MLF1(T) is resistant to kanamycin and gentamicin, but sensitive to chloramphenicol and tetracycline. The DNA G+C content is 63.0 mol% (HPLC). DNA-DNA hybridization with the most closely related species, Desulfonatronum lacustre Z-7951(T), exhibited 51 % homology. Also, the genome size (1.6x10(9) Da) and T(m) value of the genomic DNA (71+/-2 degrees C) for strain MLF1(T) were significantly different from the genome size (2.1x10(9) Da) and T(m) value (63+/-2 degrees C) for Desulfonatronum lacustre Z-7951(T). On the basis of physiological and molecular properties, the isolate was considered to be a novel species of the genus Desulfonatronum, for which the name Desulfonatronum thiodismutans sp. nov. is proposed (the type strain is MLF1(T)=ATCC BAA-395(T)=DSM 14708(T)).

Desulfonatronum Thiodismutans sp. nov., a Novel Alkaliphilic, Sulfate-reducing Bacterium Capable of Lithoautotrophic Growth

NASA Technical Reports Server (NTRS)

Pikuta, Elena V.; Hoover, Richard B.; Bej, Asim K.; Marsic, Damien; Whitman, William B.; Cleland, David; Krader, Paul

2003-01-01

A novel alkaliphilic, sulfate-reducing bacterium, strain MLF1(sup T), was isolated from sediments of soda Mono Lake, California. Gram-negative vibrio-shaped cells were observed, which were 0.6-0.7 x 1.2-2.7 microns in size, motile by a single polar flagellum and occurred singly, in pairs or as short spirilla. Growth was observed at 15-48 C (optimum, 37 C), > 1-7 % NaCI, w/v (optimum, 3%) and pH 8.0-10.0 (optimum, 9.5). The novel isolate is strictly alkaliphilic, requires a high concentration of carbonate in the growth medium and is obligately anaerobic and catalase-negative. As electron donors, strain MLF1(sup T) uses hydrogen, formate and ethanol. Sulfate, sulfite and thiosulfate (but not sulfur or nitrate) can be used as electron acceptors. The novel isolate is a lithoheterotroph and a facultative lithoautotroph that is able to grow on hydrogen without an organic source of carbon. Strain MLF1(sup T) is resistant to kanamycin and gentamicin, but sensitive to chloramphenicol and tetracycline. The DNA G+C content is 63.0 mol% (HPLC). DNA-DNA hybridization with the most closely related species, Desulfonatronum lacustre Z-7951(sup T), exhibited 51 % homology. Also, the genome size (1.6 x 10(exp 9) Da) and T(sub m) value of the genomic DNA (71 +/- 2 C) for strain MLF1(sup T) were significantly different from the genome size (2.1 x 10(exp 9) Da) and T(sub m) value (63 +/- 2 C) for Desulfonatronum lacustre Z-7951(sup T). On the basis of physiological and molecular properties, the isolate was considered to be a novel species of the genus Desulfonatronum, for which the name Desulfonatronum thiodismutans sp. nov. is proposed (the type strain is MLF1(sup T) = ATCC BAA-395(sup T) = DSM 14708(sup T)).

Cultivating a Growth Mindset in Students at a High-Achieving High School

ERIC Educational Resources Information Center

Fegley, Alan D.

2010-01-01

The purpose of this EPP is to develop a plan for changing the mindset of a large number of Haddonfield Memorial High School (HMHS) students from a fixed mindset to a growth mindset. HMHS is by most conventional measures a high performing school. Typically 100% of the students graduate with 96% of the students attending two or four year colleges…

Growth and characterization of materials for tunable lasers in the near infrared spectral region

NASA Technical Reports Server (NTRS)

Powell, Richard C.; Martin, Joel J.

1988-01-01

During this reporting period, work proceeded in two directions. The first was the development of crystal growth procedures for rare earth doped LiYF4 crystals. The procedures for growth and pre-growth treatment of starting materials for undoped LiYF4 crystals were established and good optical quality materials were grown. A significant amount of time was spent trying to establish the optimum growth parameters for Yb(3+)-doped crystals. Unfortunately, it has proven difficult to obtain large size boules of high optical quality crystals of LiYF4 with doping concentrations of Yb(3+) of several percent. Because of these problems, this research is to be changed to attempt doping with other trivalent rare earth ions such as Ho, Er, and Tm. The second research area was investigating the potential of LiNbO3:Mg,Cr and LiNbO3:Mg,Cr,Yb as possible laser materials. The results are summarized.

Large-area sheet task advanced dendritic web growth development

NASA Technical Reports Server (NTRS)

Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.

1984-01-01

The thermal models used for analyzing dendritic web growth and calculating the thermal stress were reexamined to establish the validity limits imposed by the assumptions of the models. Also, the effects of thermal conduction through the gas phase were evaluated and found to be small. New growth designs, both static and dynamic, were generated using the modeling results. Residual stress effects in dendritic web were examined. In the laboratory, new techniques for the control of temperature distributions in three dimensions were developed. A new maximum undeformed web width of 5.8 cm was achieved. A 58% increase in growth velocity of 150 micrometers thickness was achieved with dynamic hardware. The area throughput goals for transient growth of 30 and 35 sq cm/min were exceeded.

Growth of juvenile Arctica islandica under experimental conditions

NASA Astrophysics Data System (ADS)

Witbaard, R.; Franken, R.; Visser, B.

1998-02-01

In two laboratory experiments, the effects of temperature and food availability on the growth of 10- to 23-mm high specimens of the bivalve Arctica islandica were estimated. Each experimental set-up consisted of 5 treatments in which either the food supply or the temperature differed. It was demonstrated that Arctica is able to grow at temperatures as low as 1°C. A tenfold increase of shell growth was observed at temperatures between 1° and 12°C. The greatest change in growth rate took place between 1° and 6°C. Average instantaneous shell growth varies between 0.0003 at 1°C to 0.0032/day at 12°C. The results suggest that temperature hardly affects the time spent in filtration, whereas particle density strongly influences that response. Starved animals at 9°C have their siphons open during only 12% of the time, whereas the siphons of optimally fed animals were open on average during 76% of the observations. Increased siphon activity corresponded to high shell and tissue growth. At 9°C, average shell growth at the optimum cell density of 20×106 cell/l was 3.1 mm corresponding to an instantaneous rate of 0.0026/day. An algal cell density ( Isochrysis galbana, Dunaliella marina) ranging between 5 and 7×106 cell/l is just enough to keep shells alive at 9°C. Carbon conversion efficiency at 9°C is estimated to vary between 11 and 14%.

U.S. Population Growth: Prospects and Policy.

ERIC Educational Resources Information Center

McFalls, Joseph A., Jr.; And Others

1984-01-01

The Commission on Population Growth and the American Future concluded that zero population growth (ZPG) is in the best interest of the United States. To achieve ZPG in the future, the United States must keep fertility and net immigration relatively low. Practical problems are discussed. (RM)

Periodontal health status among permanent residents of low, optimum and high fluoride areas in Kolar District, India.

PubMed

Megalamanegowdru, Jayachandra; Ankola, Anil V; Vathar, Jagadishchandra; Vishwakarma, Prashanthkumar; Dhanappa, Kirankumar B; Balappanavar, Aswini Y

2012-01-01

To assess and compare the periodontal health status among permanent residents of low, optimum and high fluoride areas in Kolar District, India. A house-to-house survey was conducted in a population consisting of 925 permanent residents aged 35 to 44 years in three villages having different levels of fluoride concentrations in the drinking water. The fluoride concentrations in selected villages were 0.48 ppm (low), 1.03 ppm (optimum) and 3.21 ppm (high). The ion selective electrode method was used to estimate the fluoride concentration in the drinking water. Periodontal status was assessed using the Community Periodontal Index (CPI) and loss of attachment (LOA). Results were analysed using the chi-square test and logistic regression. The chi-square test was used to find the group differences and logistic regression to find association between the variables. The overall prevalence of periodontitis was 72.9%; specifically, prevalences were 95.4%, 76.3% and 45.7% in low, optimum and high fluoride areas, respectively. The number of sextants with shallow or deep pockets decreased (shallow pockets: 525, 438, 217; deep pockets: 183, 81, 34) from low to high fluoride areas (odds ratio: 71.3). The low fluoride area had a 7.9-fold higher risk of periodontitis than the optimum fluoride area and a 30-fold higher risk than the high fluoride area, which was highly significant (χ2 = 53.5, P < 0.0001 and χ2 = 192.8, P < 0.001, respectively). The severity of periodontal disease is inversely associated with the fluoride concentrations in drinking water. This relation can provide an approach to fluoride treatments to reduce the prevalence or incidence of this disease.

Effects of six substances on the growth and freeze-drying of Lactobacillus delbrueckii subsp. bulgaricus.

PubMed

Chen, He; Huang, Jie; Shi, Xiaoyu; Li, Yichao; Liu, Yu

2017-01-01

The efficacy of Lactobacillus delbrueckii subsp. bulgaricus as starter cultures for the dairy industry depends largely on the number of viable and active cells. Freeze-drying is the most convenient and successful method to preserve the bacterial cells. However, not all strains survived during freeze-drying. The effects of six substances including NaCl, sorbitol, mannitol, mannose, sodium glutamate, betaine added to the MRS medium on the growth and freeze-drying survival rate and viable counts of Lb. delbrueckii subsp. bulgaricus were studied through a single-factor test and Plackett-Burman design. Subsequently, the optimum freeze-drying conditions of Lb. delbrueckii subsp. bulgaricus were determined. Lb. delbrueckii subsp. bulgaricus survival rates were up to the maximum of 42.7%, 45.4%, 23.6%, while the concentrations of NaCl, sorbitol, sodium glutamate were 0.6%, 0.15%, 0.09%, respectively. In the optimum concentration, the viable counts in broth is 6.1, 6.9, 5.13 (×108 CFU/mL), respectively; the viable counts in freeze-drying power are 3.09, 5.2, 2.7 (×1010 CFU/g), respectively. Three antifreeze factors including NaCl, sorbitol, sodium glutamate have a positive effect on the growth and freeze-drying of Lb. delbrueckii subsp. bulgaricus. The results are beneficial for developing Lb. delbrueckii subsp. bulgaricus.

Modeling the Time-Varying Nature of Student Exceptionality Classification on Achievement Growth

ERIC Educational Resources Information Center

Nese, Joseph F. T.; Stevens, Joseph J.; Schulte, Ann C.; Tindal, Gerald; Elliott, Stephen N.

2017-01-01

Our purpose was to examine different approaches to modeling the time-varying nature of exceptionality classification. Using longitudinal data from one state's mathematics achievement test for 28,829 students in Grades 3 to 8, we describe the reclassification rate within special education and between general and special education, and compare four…

Analysis of social optimum for staggered shifts in a single-entry traffic corridor with no late arrivals

NASA Astrophysics Data System (ADS)

Li, Chuan-Yao; Huang, Hai-Jun; Tang, Tie-Qiao

2017-03-01

This paper investigates the traffic flow dynamics under the social optimum (SO) principle in a single-entry traffic corridor with staggered shifts from the analytical and numerical perspectives. The LWR (Lighthill-Whitham and Richards) model and the Greenshield's velocity-density function are utilized to describe the dynamic properties of traffic flow. The closed-form SO solution is analytically derived and some numerical examples are used to further testify the analytical solution. The optimum proportion of the numbers of commuters with different desired arrival times is further discussed, where the analytical and numerical results both indicate that the cumulative outflow curve under the SO principle is piecewise smooth.

Nursery cultural practices to achieve targets: A case study in western larch irrigation

Treesearch

Anthony S. Davis; Robert F. Keefe

2011-01-01

Nursery cultural practices are used to help growers achieve pre-determined size and physiological targets for seedlings. In that regard, irrigation is used to accelerate or slow growth and as a trigger for changing growth phase. In a case study highlighting the effects of irrigation on seedling development, western larch (Larix occidentalis Nutt.) seedlings were grown...

Maximizing ion current rectification in a bipolar conical nanopore fluidic diode using optimum junction location.

PubMed

Singh, Kunwar Pal

2016-10-12

The ion current rectification has been obtained as a function of the location of a heterojunction in a bipolar conical nanopore fluidic diode for different parameters to determine the junction location for maximum ion current rectification using numerical simulations. Forward current peaks for a specific location of the junction and reverse current decreases with the junction location due to a change in ion enrichment/depletion in the pore. The optimum location of the heterojunction shifts towards the tip with base/tip diameter and surface charge density, and towards the base with the electrolyte concentration. The optimum location of the heterojunction has been approximated by an equation as a function of pore length, base/tip diameter, surface charge density and electrolyte concentration. The study is useful to design a rectifier with maximum ion current rectification for practical purposes.

Low-Temperature and Rapid Growth of Large Single-Crystalline Graphene with Ethane.

PubMed

Sun, Xiao; Lin, Li; Sun, Luzhao; Zhang, Jincan; Rui, Dingran; Li, Jiayu; Wang, Mingzhan; Tan, Congwei; Kang, Ning; Wei, Di; Xu, H Q; Peng, Hailin; Liu, Zhongfan

2018-01-01

Future applications of graphene rely highly on the production of large-area high-quality graphene, especially large single-crystalline graphene, due to the reduction of defects caused by grain boundaries. However, current large single-crystalline graphene growing methodologies are suffering from low growth rate and as a result, industrial graphene production is always confronted by high energy consumption, which is primarily caused by high growth temperature and long growth time. Herein, a new growth condition achieved via ethane being the carbon feedstock to achieve low-temperature yet rapid growth of large single-crystalline graphene is reported. Ethane condition gives a growth rate about four times faster than methane, achieving about 420 µm min -1 for the growth of sub-centimeter graphene single crystals at temperature about 1000 °C. In addition, the temperature threshold to obtain graphene using ethane can be reduced to 750 °C, lower than the general growth temperature threshold (about 1000 °C) with methane on copper foil. Meanwhile ethane always keeps higher graphene growth rate than methane under the same growth temperature. This study demonstrates that ethane is indeed a potential carbon source for efficient growth of large single-crystalline graphene, thus paves the way for graphene in high-end electronical and optoelectronical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nutrition and educational achievement of urban primary schoolchildren in Malaysia.

PubMed

Shariff, Z M; Bond, J T; Johnson, N E

2000-12-01

The relationship between nutrition, health and educational achievement of school-age population in less developed countries has been of interest to many researchers due to the frequent observation that many children did not complete primary school and those who completed, did not do as well as children in the developed countries. Nevertheless, nutritional and health status by itself is not the only variable affecting educational achievement, since biological, psychological, socioeconomic and cultural factors could directly or indirectly affect both nutrition, health status and educational achievement. The mechanism by which health and nutrition influence educational achievement is not well established, but poor health and malnutrition in early childhood may affect cognitive abilities, necessary for learning process and consequently educational achievement. A study was conducted in Kuala Lumpur, Malaysia, to investigate the relationship between nutritional status and educational achievement among primary schoolchildren from low income households (n = 399). A high percentage of them were mild-significantly underweight (52%), stunted (47%) and wasted (36%) and increasingly overweight (6%). In general, more boys than girls were found to experience some form of malnutrition. While weight-for-height did not differ significantly according to family, child and school factors, weight-for-age and height-for-age differed significantly by gender. Also, height-for-age was significantly related to household income. This indicates that stunting may be a consequence of prolonged socioeconomic deprivation. Educational achievement was measured based on test scores for Malay language (ML), English language (EL) and mathematics (MT). While a majority of the schoolchildren obtained optimum scores (>75) for ML and MT, the majority of them had insufficient scores (<50) for EL. Children's total score (TS) for the three subjects was significantly associated with household socioeconomic

Emotions, Self-Regulated Learning, and Achievement in Mathematics: A Growth Curve Analysis

ERIC Educational Resources Information Center

Ahmed, Wondimu; van der Werf, Greetje; Kuyper, Hans; Minnaert, Alexander

2013-01-01

The purpose of the current study was twofold: (a) to investigate the developmental trends of 4 academic emotions (anxiety, boredom, enjoyment, and pride) and (b) to examine whether changes in emotions are linked to the changes in students' self-regulatory strategies (shallow, deep, and meta-cognitive) and achievement in mathematics. Four hundred…

Subgrouping Automata: automatic sequence subgrouping using phylogenetic tree-based optimum subgrouping algorithm.

PubMed

Seo, Joo-Hyun; Park, Jihyang; Kim, Eun-Mi; Kim, Juhan; Joo, Keehyoung; Lee, Jooyoung; Kim, Byung-Gee

2014-02-01

Sequence subgrouping for a given sequence set can enable various informative tasks such as the functional discrimination of sequence subsets and the functional inference of unknown sequences. Because an identity threshold for sequence subgrouping may vary according to the given sequence set, it is highly desirable to construct a robust subgrouping algorithm which automatically identifies an optimal identity threshold and generates subgroups for a given sequence set. To meet this end, an automatic sequence subgrouping method, named 'Subgrouping Automata' was constructed. Firstly, tree analysis module analyzes the structure of tree and calculates the all possible subgroups in each node. Sequence similarity analysis module calculates average sequence similarity for all subgroups in each node. Representative sequence generation module finds a representative sequence using profile analysis and self-scoring for each subgroup. For all nodes, average sequence similarities are calculated and 'Subgrouping Automata' searches a node showing statistically maximum sequence similarity increase using Student's t-value. A node showing the maximum t-value, which gives the most significant differences in average sequence similarity between two adjacent nodes, is determined as an optimum subgrouping node in the phylogenetic tree. Further analysis showed that the optimum subgrouping node from SA prevents under-subgrouping and over-subgrouping. Copyright © 2013. Published by Elsevier Ltd.

Optimum display luminance depends on white luminance under various ambient illuminance conditions

NASA Astrophysics Data System (ADS)

Kim, Minkoo; Jeon, Dong-Hwan; Kim, Jeong-Sik; Yu, Byung-Chang; Park, YungKyung; Lee, Seung-Woo

2018-02-01

This paper reports display luminance levels for good visibility under nine ambient illuminance conditions (50, 100, 200, 500, 1000, 2000, 5000, 10,000, and 20,000 lx) for a given white luminance level, chosen from five candidates (100, 200, 500, 1000, and 2000 cd / m2), through a psychophysical experiment. This work reveals that the luminance levels for good visibility increase as the maximum white luminance of the display increases. The white luminance dependency of display luminance is caused by the fact that the human visual system adapts to the maximum white luminance and evaluates the brightness of the display based on it. Based on the experimental results, an appropriate luminance zone under various illuminance conditions is proposed. The appropriate luminance zone varies with the maximum white luminance of the displays. This may be understood to mean that there is no absolute luminance level under a given lighting condition. To solve this issue, a new method is proposed to determine optimum luminance levels by considering both visibility and power consumption. By the proposed method, it is reported that the optimum maximum luminance lies between 200 and 500 cd / m2 for indoor use (below 500 lx). These results were verified by young adults with normal vision.

[Optimum population analysis of Jilin Province, China based on comprehensive carrying capacity.

PubMed

Li, Xiu Xia; Meng, Mei

2017-10-01

The regional moderate population model was constructed using state-space method, and the weights of relevant factors were obtained using principal component analysis. The optimum population of Jilin Province during 2005-2014 was calculated and the causes for its formation were discussed. The results showed that the optimum population of Jilin Province was in deficit from 2005-2014, and the imbalance existed between the population, resources and environment. The resources carrying population was significantly higher than the economic carrying and the ecological carrying population, indicating that the economic development of Jilin Province was established at the expense of destroying the environment. Moreover, the land resources carrying population was substantially higher than the water and energy carrying population, which was at a deficit, indicating that the economic development of Jilin Province was based on the depletion of energy and water resources. In the future, water resources carrying capacity should be improved according to the local conditions, the energy efficiency should be enhanced via the development of new energy sources, the extensive and consumption-based resource utilization should be transformed to the intensive and low-carbon type, and the production mode and consumption patterns should be changed to protect the ecological environment.

Population Growth and Economic and Social Development.

ERIC Educational Resources Information Center

Clausen, A. W.

Because evidence is clear that in many developing countries development will be postponed indefinitely unless slower population growth can be achieved soon, the international community must work together in a renewed effort to slow population growth. Assistance can be accomplished in three ways: (1) encouraging dialog aimed at forging…

Continuous Czochralski growth: Silicon sheet growth development of the large area silicon sheet task of the Low Cost Silicon Solar Array project

NASA Technical Reports Server (NTRS)

1978-01-01

The primary objective of this contract is to develop equipment and methods for the economic production of single crystal ingot material by the continuous Czochralski (CZ) process. Continuous CZ is defined for the purpose of this work as the growth of at least 100 kilograms of ingot from only one melt container. During the reporting period (October, 1977 - September, 1978), a modified grower was made fully functional and several recharge runs were performed. The largest run lasted 44 hours and over 42 kg of ingot was produced. Little, if any, degradation in efficiency was observed as a result of pulling multiple crystals from one crucible. Solar efficiencies observed were between 9.3 and 10.4% AMO (13.0 and 14.6% AMI) compared to 10.5% (14.7% AMI) for optimum CZ material control samples. Using the SAMICS/IPEG format, economic analysis of continuous CZ suggests that 1986 DoE cost goals can only be met by the growth of large diameter, large mass crystals.

Science Achievement Gaps Begin Very Early, Persist, and Are Largely Explained by Modifiable Factors

ERIC Educational Resources Information Center

Morgan, Paul L.; Farkas, George; Hillemeier, Marianne M.; Maczuga, Steve

2016-01-01

We examined the age of onset, over-time dynamics, and mechanisms underlying science achievement gaps in U.S. elementary and middle schools. To do so, we estimated multilevel growth models that included as predictors children's own general knowledge, reading and mathematics achievement, behavioral self-regulation, sociodemographics, other child-…

Can nutrient limitations explain low and declining white spruce growth near the Arctic treeline in the eastern Brooks Range, Alaska?

NASA Astrophysics Data System (ADS)

Ellison, S.; Sullivan, P. F.

2014-12-01

The position of the Arctic treeline is of critical importance for global carbon cycling and surface energy budgets. However, controls on tree growth at treeline remain uncertain. In the Alaskan Brooks Range, 20th century warming has caused varying growth responses among treeline trees, with trees in the west responding positively, while trees in the east have responded negatively. The prevailing explanation of this trend ascribes the negative growth response to warming-induced drought stress in the eastern Brooks Range. However, recent measurements of carbon isotope discrimination in tree rings, xylem sap flow and needle gas exchange suggest that drought stress cannot explain these regional growth declines. Additionally, evidence from the western Brooks Range suggests that nutrient availability, rather than drought stress, may be the proximate control on tree growth. In this study, we investigated the hypothesis that low and declining growth of eastern Brooks Range trees is due to low and declining soil nutrient availability, which may continue to decrease with climate change as soils become drier and microbial activity declines. We compared microclimate, tree performance, and a wide range of proxies for soil nutrient availability in four watersheds along a west-east transect in the Brooks Range during the growing seasons of 2013 and 2014. We hypothesized that soil nutrient availability would track closely with the strong west-east precipitation gradient, with higher rainfall and greater soil nutrient availability in the western Brooks Range. We expected to find that soil water contents in the west are near optimum for nitrogen mineralization, while those in the east are below optimum. Needle nitrogen concentration, net photosynthesis, branch extension growth, and growth in the main stem are expected to decline with the hypothesized decrease in soil nutrient availability. The results of our study will elucidate the current controls on growth of trees near the

A Decision Support System for Optimum Use of Fertilizers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoskinson, Reed Louis; Hess, John Richard; Fink, Raymond Keith

1999-07-01

The Decision Support System for Agriculture (DSS4Ag) is an expert system being developed by the Site-Specific Technologies for Agriculture (SST4Ag) precision farming research project at the INEEL. DSS4Ag uses state-of-the-art artificial intelligence and computer science technologies to make spatially variable, site-specific, economically optimum decisions on fertilizer use. The DSS4Ag has an open architecture that allows for external input and addition of new requirements and integrates its results with existing agricultural systems’ infrastructures. The DSS4Ag reflects a paradigm shift in the information revolution in agriculture that is precision farming. We depict this information revolution in agriculture as an historic trend inmore » the agricultural decision-making process.« less

A Decision Support System for Optimum Use of Fertilizers

DOE Office of Scientific and Technical Information (OSTI.GOV)

R. L. Hoskinson; J. R. Hess; R. K. Fink

1999-07-01

The Decision Support System for Agriculture (DSS4Ag) is an expert system being developed by the Site-Specific Technologies for Agriculture (SST4Ag) precision farming research project at the INEEL. DSS4Ag uses state-of-the-art artificial intelligence and computer science technologies to make spatially variable, site-specific, economically optimum decisions on fertilizer use. The DSS4Ag has an open architecture that allows for external input and addition of new requirements and integrates its results with existing agricultural systems' infrastructures. The DSS4Ag reflects a paradigm shift in the information revolution in agriculture that is precision farming. We depict this information revolution in agriculture as an historic trend inmore » the agricultural decision-making process.« less

Integrated Curriculum and Subject-based Curriculum: Achievement and Attitudes

NASA Astrophysics Data System (ADS)

Casady, Victoria

The research conducted for this mixed-method study, qualitative and quantitative, analyzed the results of an academic year-long study to determine whether the use of an integrated fourth grade curriculum would benefit student achievement in the areas of English language arts, social studies, and science more than a subject-based traditional curriculum. The research was conducted based on the international, national, and state test scores, which show a slowing or lack of growth. Through pre- and post-assessments, student questionnaires, and administrative interviews, the researcher analyzed the phenomenological experiences of the students to determine if the integrated curriculum was a beneficial restructuring of the curriculum. The research questions for this study focused on the achievement and attitudes of the students in the study and whether the curriculum they were taught impacted their achievement and attitudes over the course of one school year. The curricula for the study were organized to cover the current standards, where the integrated curriculum focused on connections between subject areas to help students make connections to what they are learning and the world beyond the classroom. The findings of this study indicated that utilizing the integrated curriculum could increase achievement as well as students' attitudes toward specific content areas. The ANOVA analysis for English language arts was not determined to be significant; although, greater growth in the students from the integrated curriculum setting was recorded. The ANOVA for social studies (0.05) and the paired t-tests (0.001) for science both determined significant positive differences. The qualitative analysis led to the discovery that the experiences of the students from the integrated curriculum setting were more positive. The evaluation of the data from this study led the researcher to determine that the integrated curriculum was a worthwhile endeavor to increase achievement and attitudes

Kindergarten Children’s Growth Trajectories in Reading and Mathematics: Who Falls Increasingly Behind?

PubMed Central

Morgan, Paul L.; Farkas, George; Wu, Qiong

2015-01-01

We used a large sample of children (N ≈ 7,400) participating in the Early Childhood Longitudinal Study – Kindergarten Cohort to estimate kindergarten children’s academic achievement growth trajectories in reading and mathematics. We were particularly interested in whether the growth trajectories of children with learning disabilities (LD) or speech language impairments (SLI)—as well as those of other groups of children—were consistent with a cumulative or compensatory developmental cycle. Both LD and SLI children displayed significantly lower levels of kindergarten reading achievement than non-disabled children. However, and over the subsequent five years of elementary school, only children with SLI lagged increasingly behind non-disabled peers in their reading skills growth. We observed a different pattern for mathematics achievement. Children with LD, but not SLI, lagged increasingly behind non-disabled children in their mathematics skills growth. We also observed some consistency in “poor-get-poorer” effects across reading and mathematic achievement for additional population subgroups. Those kindergarten children who were from lower socio-economic status (SES) families, who were African-American, and who more frequently displayed learning-related behaviors problems initially had lower levels of reading and mathematics achievement and also lagged increasingly behind in their acquisition of these skills over time. Some groups of children, including those with SLI, experience a cumulative rather than compensatory cycle of achievement growth. PMID:21856991

An Experimental Study of Dependence of Optimum TBM Cutter Spacing on Pre-set Penetration Depth in Sandstone Fragmentation

NASA Astrophysics Data System (ADS)

Han, D. Y.; Cao, P.; Liu, J.; Zhu, J. B.

2017-12-01

Cutter spacing is an essential parameter in the TBM design. However, few efforts have been made to study the optimum cutter spacing incorporating penetration depth. To investigate the influence of pre-set penetration depth and cutter spacing on sandstone breakage and TBM performance, a series of sequential laboratory indentation tests were performed in a biaxial compression state. Effects of parameters including penetration force, penetration depth, chip mass, chip size distribution, groove volume, specific energy and maximum angle of lateral crack were investigated. Results show that the total mass of chips, the groove volume and the observed optimum cutter spacing increase with increasing pre-set penetration depth. It is also found that the total mass of chips could be an alternative means to determine optimum cutter spacing. In addition, analysis of chip size distribution suggests that the mass of large chips is dominated by both cutter spacing and pre-set penetration depth. After fractal dimension analysis, we found that cutter spacing and pre-set penetration depth have negligible influence on the formation of small chips and that small chips are formed due to squeezing of cutters and surface abrasion caused by shear failure. Analysis on specific energy indicates that the observed optimum spacing/penetration ratio is 10 for the sandstone, at which, the specific energy and the maximum angle of lateral cracks are smallest. The findings in this paper contribute to better understanding of the coupled effect of cutter spacing and pre-set penetration depth on TBM performance and rock breakage, and provide some guidelines for cutter arrangement.

On Optimum Power Allocation for Multi-Antenna Wideband Helicopter-to-Ground Communications

DTIC Science & Technology

2014-03-01

optimum [1]. In frequency selective fading, the general approach is to use OFDM and apply these techniques on a per subcarrier basis. This work was...Contracting Office under contract W900KK-09-C-0016. Given the constraints described above, OFDM is often of limited interest in helicopter-to-ground...Naguib, and R. Calderbank, “Finite-length MIMO decision feedback equalization for space-time block-coded signals over multipath-fading channels,” IEEE

A Systems Modeling Approach to Forecast Corn Economic Optimum Nitrogen Rate.

PubMed

Puntel, Laila A; Sawyer, John E; Barker, Daniel W; Thorburn, Peter J; Castellano, Michael J; Moore, Kenneth J; VanLoocke, Andrew; Heaton, Emily A; Archontoulis, Sotirios V

2018-01-01

Historically crop models have been used to evaluate crop yield responses to nitrogen (N) rates after harvest when it is too late for the farmers to make in-season adjustments. We hypothesize that the use of a crop model as an in-season forecast tool will improve current N decision-making. To explore this, we used the Agricultural Production Systems sIMulator (APSIM) calibrated with long-term experimental data for central Iowa, USA (16-years in continuous corn and 15-years in soybean-corn rotation) combined with actual weather data up to a specific crop stage and historical weather data thereafter. The objectives were to: (1) evaluate the accuracy and uncertainty of corn yield and economic optimum N rate (EONR) predictions at four forecast times (planting time, 6th and 12th leaf, and silking phenological stages); (2) determine whether the use of analogous historical weather years based on precipitation and temperature patterns as opposed to using a 35-year dataset could improve the accuracy of the forecast; and (3) quantify the value added by the crop model in predicting annual EONR and yields using the site-mean EONR and the yield at the EONR to benchmark predicted values. Results indicated that the mean corn yield predictions at planting time ( R 2 = 0.77) using 35-years of historical weather was close to the observed and predicted yield at maturity ( R 2 = 0.81). Across all forecasting times, the EONR predictions were more accurate in corn-corn than soybean-corn rotation (relative root mean square error, RRMSE, of 25 vs. 45%, respectively). At planting time, the APSIM model predicted the direction of optimum N rates (above, below or at average site-mean EONR) in 62% of the cases examined ( n = 31) with an average error range of ±38 kg N ha -1 (22% of the average N rate). Across all forecast times, prediction error of EONR was about three times higher than yield predictions. The use of the 35-year weather record was better than using selected historical weather

Optimum Temperatures for Net Primary Productivity of Three Tropical Seagrass Species.

PubMed

Collier, Catherine J; Ow, Yan X; Langlois, Lucas; Uthicke, Sven; Johansson, Charlotte L; O'Brien, Katherine R; Hrebien, Victoria; Adams, Matthew P

2017-01-01

Rising sea water temperature will play a significant role in responses of the world's seagrass meadows to climate change. In this study, we investigated seasonal and latitudinal variation (spanning more than 1,500 km) in seagrass productivity, and the optimum temperatures at which maximum photosynthesis and net productivity (for the leaf and the whole plant) occurs, for three seagrass species ( Cymodocea serrulata, Halodule uninervis , and Zostera muelleri ). To obtain whole plant net production, photosynthesis, and respiration rates of leaves and the root/rhizome complex were measured using oxygen-sensitive optodes in closed incubation chambers at temperatures ranging from 15 to 43°C. The temperature-dependence of photosynthesis and respiration was fitted to empirical models to obtain maximum metabolic rates and thermal optima. The thermal optimum ( T opt ) for gross photosynthesis of Z. muelleri , which is more commonly distributed in sub-tropical to temperate regions, was 31°C. The T opt for photosynthesis of the tropical species, H. uninervis and C. serrulata , was considerably higher (35°C on average). This suggests that seagrass species are adapted to water temperature within their distributional range; however, when comparing among latitudes and seasons, thermal optima within a species showed limited acclimation to ambient water temperature ( T opt varied by 1°C in C. serrulata and 2°C in H. uninervis , and the variation did not follow changes in ambient water temperature). The T opt for gross photosynthesis were higher than T opt calculated from plant net productivity, which includes above- and below-ground respiration for Z. muelleri (24°C) and H. uninervis ( 33°C), but remained unchanged at 35°C in C. serrulata . Both estimated plant net productivity and T opt are sensitive to the proportion of below-ground biomass, highlighting the need for consideration of below- to above-ground biomass ratios when applying thermal optima to other meadows. The

A Systems Modeling Approach to Forecast Corn Economic Optimum Nitrogen Rate

PubMed Central

Puntel, Laila A.; Sawyer, John E.; Barker, Daniel W.; Thorburn, Peter J.; Castellano, Michael J.; Moore, Kenneth J.; VanLoocke, Andrew; Heaton, Emily A.; Archontoulis, Sotirios V.

2018-01-01

Historically crop models have been used to evaluate crop yield responses to nitrogen (N) rates after harvest when it is too late for the farmers to make in-season adjustments. We hypothesize that the use of a crop model as an in-season forecast tool will improve current N decision-making. To explore this, we used the Agricultural Production Systems sIMulator (APSIM) calibrated with long-term experimental data for central Iowa, USA (16-years in continuous corn and 15-years in soybean-corn rotation) combined with actual weather data up to a specific crop stage and historical weather data thereafter. The objectives were to: (1) evaluate the accuracy and uncertainty of corn yield and economic optimum N rate (EONR) predictions at four forecast times (planting time, 6th and 12th leaf, and silking phenological stages); (2) determine whether the use of analogous historical weather years based on precipitation and temperature patterns as opposed to using a 35-year dataset could improve the accuracy of the forecast; and (3) quantify the value added by the crop model in predicting annual EONR and yields using the site-mean EONR and the yield at the EONR to benchmark predicted values. Results indicated that the mean corn yield predictions at planting time (R2 = 0.77) using 35-years of historical weather was close to the observed and predicted yield at maturity (R2 = 0.81). Across all forecasting times, the EONR predictions were more accurate in corn-corn than soybean-corn rotation (relative root mean square error, RRMSE, of 25 vs. 45%, respectively). At planting time, the APSIM model predicted the direction of optimum N rates (above, below or at average site-mean EONR) in 62% of the cases examined (n = 31) with an average error range of ±38 kg N ha−1 (22% of the average N rate). Across all forecast times, prediction error of EONR was about three times higher than yield predictions. The use of the 35-year weather record was better than using selected historical weather years

Growth of Cu 0.5Tl 0.5Ba 2Ca 3Cu 4-yZn yO 12-δ superconductor with optimum carriers

NASA Astrophysics Data System (ADS)

Mumtaz, M.; Khan, Nawazish A.; Khan, E. U.

2010-05-01

We have tried to vary the carriers concentration in Cu 0.5Tl 0.5Ba 2Ca 3Cu 4-yZn yO 12-δ ( y = 0, 1, 1.5, 2, 2.5) superconductor with the help of post-annealing experiments carried out in nitrogen, oxygen and air and to investigate its effects on the superconductivity parameters. The zero resistivity critical temperature [ T c( R = 0)], the magnitude of diamagnetism and critical current [ I c( H = 0)] are found to increase in Zn free samples after post-annealing in oxygen and air, while these superconducting properties have been suppressed after post-annealing in nitrogen at 550 °C for 6 h. The post-annealing of Zn-doped samples in air has marginally increased the superconducting properties, while these properties have been suppressed after post-annealing in nitrogen and oxygen. These studies have led us to the definite conclusion that the Zn-doped material has grown with optimum carriers concentration.

Determination of optimum processing temperature for transformation of glyceryl monostearate.

PubMed

Yajima, Toshio; Itai, Shigeru; Takeuchi, Hirofumi; Kawashima, Yoshiaki

2002-11-01

The purpose of this study was to clarify the mechanism of transformation from alpha-form to beta-form via beta'-form of glyceryl monostearate (GM) and to determine the optimum conditions of heat-treatment for physically stabilizing GM in a pharmaceutical formulation. Thermal analysis repeated twice using a differential scanning calorimeter (DSC) were performed on mixtures of two crystal forms. In the first run (enthalpy of melting: DeltaH1), two endothermic peaks of alpha-form and beta-form were observed. However, in the second run (enthalpy of melting: DeltaH2), only the endothermic peak of the alpha-form was observed. From a strong correlation observed between the beta-form content in the mixture of alpha-form and beta-form and the enthalpy change, (DeltaH1-DeltaH2)/DeltaH2, beta-form content was expressed as a function of the enthalpy change. Using this relation, the stable beta-form content during the heat-treatment could be determined, and the maximum beta-form content was obtained when the heat-treatment was carried out at 50 degrees C. An inflection point existed in the time course of transformation of alpha-form to beta-form. It was assumed that almost all of alpha-form transformed to beta'-form at this point, and that subsequently only transformation from beta'-form to beta-form occurred. Based on this aspect, the transformation rate equations were derived as consecutive reaction. Experimental data coincided well with the theoretical curve. In conclusion, GM was transformed in the consecutive reaction, and 50 degrees C was the optimum heat-treatment temperature for transforming GM from the alpha-form to the stable beta-form.

Designing nacre-like materials for simultaneous stiffness, strength and toughness: Optimum materials, composition, microstructure and size