Targeted Next Generation Sequencing with ThyroSeq v2.1 for Indeterminate Thyroid Nodules in Clinical Practice.

PubMed

Witt, Robert L

2016-12-01

To determine if patients elect molecular testing over diagnostic surgery or repeat fine needle aspiration for indeterminate thyroid nodules. Can ThyroSeq v2.1 molecular testing reduce diagnostic thyroid surgery and rule out cancer? Retrospective review Setting: Single institution, single-practice surgeon. Fifteen month retrospective review of indeterminate thyroid nodules that went on to ThyroSeq v2.1 testing. 286 patients met American Thyroid Association guideline criteria for surgeon- performed, ultrasound-guided fine needle aspiration for a thyroid nodule with on-site cytopathology. The indeterminate (Bethesda III or IV) fine needle aspiration cytology rate was 9.1 percent. Prevalence of malignancy in indeterminate nodules was 19 percent. 26/26 (100 percent) patients with indeterminate thyroid nodules elected molecular testing. 16 patients had no mutation, 9 had one or more mutations, and I had no result. 16 of 25 (64 percent) patients with no mutation elected not to undergo diagnostic surgery for indeterminate thyroid nodules. Patients demonstrated a strong preference for molecular testing instead of diagnostic thyroid surgery for indeterminate thyroid nodules. All patients in this series, 25/25 (100 percent) with indeterminate thyroid nodules elected molecular testing instead of repeat biopsy or diagnostic thyroid surgery. 16 of 25 (64 percent) patients tested had no mutation. All 16/16 (100 percent) patients with no mutation on ThyroSeq "rule out" testing elected active surveillance rather than surgery or biopsy, reducing diagnostic surgery. The risk of malignancy among mutation negative patients was not definitively established. There are a number of factors currently that may mute the power of "rule in" testing.

Proviral Features of Human T Cell Leukemia Virus Type 1 in Carriers with Indeterminate Western Blot Analysis Results

PubMed Central

Sekizuka, Tsuyoshi; Yamochi, Tadanori; Firouzi, Sanaz; Sato, Tomoo; Umeki, Kazumi; Sasaki, Daisuke; Hasegawa, Hiroo; Kubota, Ryuji; Sobata, Rieko; Matsumoto, Chieko; Kaneko, Noriaki; Momose, Haruka; Araki, Kumiko; Saito, Masumichi; Nosaka, Kisato; Utsunomiya, Atae; Koh, Ki-Ryang; Ogata, Masao; Uchimaru, Kaoru; Iwanaga, Masako; Sagara, Yasuko; Yamano, Yoshihisa; Okayama, Akihiko; Miura, Kiyonori; Satake, Masahiro; Saito, Shigeru; Itabashi, Kazuo; Yamaguchi, Kazunari; Kuroda, Makoto; Watanabe, Toshiki; Okuma, Kazu

2017-01-01

ABSTRACT Western blotting (WB) for human T cell leukemia virus type 1 (HTLV-1) is performed to confirm anti-HTLV-1 antibodies detected at the initial screening of blood donors and in pregnant women. However, the frequent occurrence of indeterminate results is a problem with this test. We therefore assessed the cause of indeterminate WB results by analyzing HTLV-1 provirus genomic sequences. A quantitative PCR assay measuring HTLV-1 provirus in WB-indeterminate samples revealed that the median proviral load was approximately 100-fold lower than that of WB-positive samples (0.01 versus 0.71 copy/100 cells). Phylogenic analysis of the complete HTLV-1 genomes of WB-indeterminate samples did not identify any specific phylogenetic groups. When we analyzed the nucleotide changes in 19 HTLV-1 isolates from WB-indeterminate samples, we identified 135 single nucleotide substitutions, composed of four types, G to A (29%), C to T (19%), T to C (19%), and A to G (16%). In the most frequent G-to-A substitution, 64% occurred at GG dinucleotides, indicating that APOBEC3G is responsible for mutagenesis in WB-indeterminate samples. Moreover, interestingly, five WB-indeterminate isolates had nonsense mutations in Pol and/or Tax, Env, p12, and p30. These findings suggest that WB-indeterminate carriers have low production of viral antigens because of a combination of a low proviral load and mutations in the provirus, which may interfere with host recognition of HTLV-1 antigens. PMID:28701419

The predictive value of dominant nodules and the management of indeterminate group in multinodular goiter.

PubMed

Acıoğlu, Engin; Yiğit, Özgür; Seden, Nihal; Huq, Gülben Erdem

2012-01-01

The objectives of this study were to determine the predictive value of dominant nodules (DNs) in multinodular goiters (MNGs), and to stratify the risk of malignancy within the indeterminate category. The study design was retrospective study of patients with MNG. A total of 140 patients were reviewed. Fine needle aspiration biopsy (FNAB) findings for all DNs were categorized into four groups: (1) benign, (2) positive or suspicious for malignancy, (3) indeterminate, and (4) non-diagnostic. All FNAB specimens of the indeterminate group were also evaluated for the presence of Hurthle cell metaplasia and were categorized according to the presence of cytological atypia. Cytohistological comparison was then performed. Mean number and diameter of the DNs were 1.45 and 25.6 mm, respectively. Based on final histopathology, 22.14% of the patients had thyroid malignancy and 74.2% of thyroid carcinomas were located in DNs. The number of DNs was significantly larger in malignant thyroid glands than in benign ones. In total, 22.6% of the indeterminate FNABs were malignant. FNABs of the indeterminate group that included atypical cells had a statistically significant higher incidence of malignancy. The presence of Hurthle cells was not statistically different in malignant and benign nodules upon final histological diagnosis. In conclusion, FNAB of only DNs in MNG could determine thyroid malignancy in 75% of patients. The DN number might be required for the predictive value of malignancy. A subclassification of the indeterminate group, based on the presence or absence of cytological atypia, is necessary to better assess the risk of malignancy.

Frequency of indeterminate results from an interferon-gamma release assay among HIV-infected individuals

PubMed Central

de Oliveira, Sandra Maria do Valle Leone; Trajman, Anete; Paniago, Anamaria Mello Miranda; Motta-Castro, Ana Rita Coimbra; Ruffino-Netto, Antonio; Maciel, Ethel Leonor Noia; Croda, Julio; Bonecini-Almeida, Maria da Gloria

2017-01-01

ABSTRACT Objective: To evaluate the frequency of and factors associated with indeterminate interferon-gamma release assay (IGRA) results in people living with HIV/AIDS (PLWHA). Methods: We tested 81 PLWHA in the central-west region of Brazil, using the tuberculin skin test and an IGRA. Information on sociodemographic and clinical variables was gathered through the use of questionnaires and from medical records. The association of those variables with indeterminate results was analyzed by calculating the adjusted ORs in a multivariate logistic regression model. Concordance was evaluated by determining the kappa statistic. Results: Among the 81 patients evaluated, the tuberculin skin test results were positive in 18 (22.2%) of the patients, and the IGRA results were positive in 10 (12.3%), with a kappa of 0.62. The IGRA results were indeterminate in 22 (27.1%) of the patients (95% CI: 17.8-38.1%). The odds of obtaining indeterminate results were significantly higher in smokers (adjusted OR = 6.0; 95% CI: 1.4-26.7) and in samples stored for less than 35 days (adjusted OR = 14.0; 95% CI: 3.1-64.2). Patients with advanced immunosuppression (CD4+ T-cell count < 200 cells/mm3) were at a higher risk for indeterminate results (OR adjusted for smoking and inadequate duration of sample storage = 4.7; 95% CI: 0.91-24.0), although the difference was not significant. Conclusions: The high prevalence of indeterminate results can be a major limitation for the routine use of IGRAs in PLWHA. The need to repeat the test increases its costs and should be taken into account in cost-effectiveness studies. The processing of samples can significantly alter the results. PMID:28746533

Proviral Features of Human T Cell Leukemia Virus Type 1 in Carriers with Indeterminate Western Blot Analysis Results.

PubMed

Kuramitsu, Madoka; Sekizuka, Tsuyoshi; Yamochi, Tadanori; Firouzi, Sanaz; Sato, Tomoo; Umeki, Kazumi; Sasaki, Daisuke; Hasegawa, Hiroo; Kubota, Ryuji; Sobata, Rieko; Matsumoto, Chieko; Kaneko, Noriaki; Momose, Haruka; Araki, Kumiko; Saito, Masumichi; Nosaka, Kisato; Utsunomiya, Atae; Koh, Ki-Ryang; Ogata, Masao; Uchimaru, Kaoru; Iwanaga, Masako; Sagara, Yasuko; Yamano, Yoshihisa; Okayama, Akihiko; Miura, Kiyonori; Satake, Masahiro; Saito, Shigeru; Itabashi, Kazuo; Yamaguchi, Kazunari; Kuroda, Makoto; Watanabe, Toshiki; Okuma, Kazu; Hamaguchi, Isao

2017-09-01

Western blotting (WB) for human T cell leukemia virus type 1 (HTLV-1) is performed to confirm anti-HTLV-1 antibodies detected at the initial screening of blood donors and in pregnant women. However, the frequent occurrence of indeterminate results is a problem with this test. We therefore assessed the cause of indeterminate WB results by analyzing HTLV-1 provirus genomic sequences. A quantitative PCR assay measuring HTLV-1 provirus in WB-indeterminate samples revealed that the median proviral load was approximately 100-fold lower than that of WB-positive samples (0.01 versus 0.71 copy/100 cells). Phylogenic analysis of the complete HTLV-1 genomes of WB-indeterminate samples did not identify any specific phylogenetic groups. When we analyzed the nucleotide changes in 19 HTLV-1 isolates from WB-indeterminate samples, we identified 135 single nucleotide substitutions, composed of four types, G to A (29%), C to T (19%), T to C (19%), and A to G (16%). In the most frequent G-to-A substitution, 64% occurred at GG dinucleotides, indicating that APOBEC3G is responsible for mutagenesis in WB-indeterminate samples. Moreover, interestingly, five WB-indeterminate isolates had nonsense mutations in Pol and/or Tax, Env, p12, and p30. These findings suggest that WB-indeterminate carriers have low production of viral antigens because of a combination of a low proviral load and mutations in the provirus, which may interfere with host recognition of HTLV-1 antigens. Copyright © 2017 American Society for Microbiology.

Neuroscience, quantum indeterminism and the Cartesian soul.

PubMed

Clarke, Peter G H

2014-02-01

Quantum indeterminism is frequently invoked as a solution to the problem of how a disembodied soul might interact with the brain (as Descartes proposed), and is sometimes invoked in theories of libertarian free will even when they do not involve dualistic assumptions. Taking as example the Eccles-Beck model of interaction between self (or soul) and brain at the level of synaptic exocytosis, I here evaluate the plausibility of these approaches. I conclude that Heisenbergian uncertainty is too small to affect synaptic function, and that amplification by chaos or by other means does not provide a solution to this problem. Furthermore, even if Heisenbergian effects did modify brain functioning, the changes would be swamped by those due to thermal noise. Cells and neural circuits have powerful noise-resistance mechanisms, that are adequate protection against thermal noise and must therefore be more than sufficient to buffer against Heisenbergian effects. Other forms of quantum indeterminism must be considered, because these can be much greater than Heisenbergian uncertainty, but these have not so far been shown to play a role in the brain. Copyright © 2013 Elsevier Inc. All rights reserved.

Cancer Risk Associated with Nuclear Atypia in Cytologically Indeterminate Thyroid Nodules: A Systematic Review and Meta-Analysis.

PubMed

Valderrabano, Pablo; Khazai, Laila; Thompson, Zachary J; Sharpe, Susan C; Tarasova, Valentina D; Otto, Kristen J; Hallanger-Johnson, Julie E; Wadsworth, J Trad; Wenig, Bruce M; Chung, Christine H; Centeno, Barbara A; McIver, Bryan

2018-02-01

Indeterminate categories of thyroid cytopathology (categories B-III and B-IV of the Bethesda system) are integrated by a heterogeneous spectrum of cytological scenarios that are generally clustered for analysis and management recommendations. It has been suggested that aspirates exhibiting nuclear atypia have a higher risk of malignancy. This study aimed to assess whether cytologically indeterminate thyroid nodules with nuclear atypia have a significantly higher cancer risk than those without nuclear atypia. On June 30, 2016, PubMed and EMBASE were searched for articles in English or Spanish using a search strategy developed by an endocrinologist and a librarian. Case reports were excluded, and no date limits were used. The references of all included studies were also screened for relevant missing studies. Studies were included if the prevalences of malignancy of cytologically indeterminate thyroid nodules with histological confirmation with and without nuclear atypia were reported. Studies were excluded if they had: (i) nodules suspicious for malignancy; (ii) nodules with non-indeterminate (B-III or B-IV) cytology on repeated biopsy, if performed; (iii) nodules not consecutively evaluated; or (iv) cohorts overlapping with another larger series. Two investigators independently assessed the eligibility and risk of bias of the studies. PRISMA and MOOSE guidelines were followed. Summary data were extracted from published reports by one investigator and independently reviewed by another. Data were pooled using a random-effects model. Heterogeneity was explored using subgroup analysis and mixed-effect model meta-regression. The odds ratio for malignancy of cytologically indeterminate thyroid nodules with nuclear atypia over cytologically indeterminate thyroid nodules without nuclear atypia was calculated. Of 2571 retrieved studies, 20 were eligible. The meta-analysis was conducted on summary data of 3532 cytologically indeterminate thyroid nodules: 1162 with and 2370

Mathematics in Chemistry: Indeterminate Forms and Their Meaning

ERIC Educational Resources Information Center

Segurado, Manuel A. P.; Silva, Margarida F. B.; Castro, Rita

2011-01-01

The mathematical language and its tools are complementary to the formalism in chemistry, in particular at an advanced level. It is thus crucial, for its understanding, that students acquire a solid knowledge in Calculus and that they know how to apply it. The frequent occurrence of indeterminate forms in multiple areas, particularly in Physical…

The super-indeterminism in orthodox quantum mechanics does not implicate the reality of experimenter free will

NASA Astrophysics Data System (ADS)

Walleczek, J.

2016-03-01

The concept of ‘super-indeterminism’ captures the notion that the free choice assumption of orthodox quantum mechanics necessitates only the following requirement: an agent's free-choice performance in the selection of measurement settings must not represent an exception to the rule of irreducible quantum indeterminism in the physical universe (i.e, “universal indeterminism”). Any additional metaphysical speculation, such as to whether quantum indeterminism, i.e., intrinsic randomness, implicates the reality of experimenter “freedom”, “free will”, or “free choice”, is redundant in relation to the predictive success of orthodox quantum mechanics. Accordingly, super-indeterminism views as redundant also, from a technical standpoint, whether an affirmative or a negative answer is claimed in reference to universal indeterminism as a necessary precondition for experimenter freedom. Super-indeterminism accounts, for example, for the circular reasoning which is implicit in the free will theorem by Conway and Kochen [1,2]. The concept of super-indeterminism is of great assistance in clarifying the often misunderstood meaning of the concept of “free variables” as used by John Bell [3]. The present work argues that Bell sought an operational, effective free will theorem, one based upon the notion of “determinism without predetermination”, i.e., one wherein “free variables” represent universally uncomputable variables. In conclusion, the standard interpretation of quantum theory does not answer, and does not need to answer in order to ensure the predictive success of orthodox theory, the question of whether either incompatibilism or compatibilism is valid in relation to free-will metaphysics and to the free-will phenomenology of experimenter agents in quantum mechanics.

Survival Outcomes for Patients With Indeterminate 18FDG-PET Scan for Extrahepatic Disease Before Liver Resection for Metastatic Colorectal Cancer: A Retrospective Cohort Study Using a Prospectively Maintained Database to Analyze Survival Outcomes for Patients With Indeterminate Extrahepatic Disease on 18FDG-PET Scan Before Liver Resection for Metastatic Colorectal Cancer.

PubMed

Wong, Geoffrey Yuet Mun; Kumar, Rajiv; Beeke, Carol; Ullah, Shahid; Chen, John; Karapetis, Christos; Price, Timothy; Padbury, Rob

2018-05-01

The aim of this study was to evaluate overall survival (OS) and cancer recurrence for patients with indeterminate positron emission tomography (PET) scan for extrahepatic disease (EHD) before liver resection (LR) for colorectal liver metastases (CLMs). Indeterminate EHD as determined by PET imaging indicates a probability of extrahepatic malignancy and potentially excludes patients from undergoing LR for CLM. In a retrospective analysis of prospectively collected data from February 2006 to December 2014, OS for patients with indeterminate EHD on FDG-PET scan before LR for CLM was performed using standard survival analysis methods, including Kaplan-Meier estimator and Cox proportional hazard models for multivariate analyses. Postoperative imaging was used as reference to evaluate the association between indeterminate EHD and recurrence. Of 267 patients with PET scans before LR, 197 patients had no EHD and 70 patients had indeterminate EHD. Median follow-up was 33 months. The estimated 5-year OS was 60.8% versus 59.4% for indeterminate and absent EHD, respectively (P = 0.625). Disease-free survival was comparable between both groups (P = 0.975) and overall recurrence was 57.1% and 59.5% for indeterminate and absent EHD, respectively (P = 0.742). About 16.9% of recurrence was associated with the site of indeterminate EHD, with 80% of associated recurrence occurring in the thorax. The site of indeterminate EHD appears to have a predictive value for recurrence, with indeterminate EHD in the thorax having a higher probability of malignancy. The evidence in this report supports the critical evaluation of PET scan results and that patients are not denied potential curative LR unless the evidence for unresectable EHD is certain.

Asymptotically optimum multialternative sequential procedures for discernment of processes minimizing average length of observations

NASA Astrophysics Data System (ADS)

Fishman, M. M.

1985-01-01

The problem of multialternative sequential discernment of processes is formulated in terms of conditionally optimum procedures minimizing the average length of observations, without any probabilistic assumptions about any one occurring process, rather than in terms of Bayes procedures minimizing the average risk. The problem is to find the procedure that will transform inequalities into equalities. The problem is formulated for various models of signal observation and data processing: (1) discernment of signals from background interference by a multichannel system; (2) discernment of pulse sequences with unknown time delay; (3) discernment of harmonic signals with unknown frequency. An asymptotically optimum sequential procedure is constructed which compares the statistics of the likelihood ratio with the mean-weighted likelihood ratio and estimates the upper bound for conditional average lengths of observations. This procedure is shown to remain valid as the upper bound for the probability of erroneous partial solutions decreases approaching zero and the number of hypotheses increases approaching infinity. It also remains valid under certain special constraints on the probability such as a threshold. A comparison with a fixed-length procedure reveals that this sequential procedure decreases the length of observations to one quarter, on the average, when the probability of erroneous partial solutions is low.

Cost-effectiveness of lobectomy versus genetic testing (Afirma®) for indeterminate thyroid nodules: Considering the costs of surveillance.

PubMed

Balentine, Courtney J; Vanness, David J; Schneider, David F

2018-01-01

We evaluated whether diagnostic thyroidectomy for indeterminate thyroid nodules would be more cost-effective than genetic testing after including the costs of long-term surveillance. We used a Markov decision model to estimate the cost-effectiveness of thyroid lobectomy versus genetic testing (Afirma®) for evaluation of indeterminate (Bethesda 3-4) thyroid nodules. The base case was a 40-year-old woman with a 1-cm indeterminate nodule. Probabilities and estimates of utilities were obtained from the literature. Cost estimates were based on Medicare reimbursements with a 3% discount rate for costs and quality-adjusted life-years. During a 5-year period after the diagnosis of indeterminate thyroid nodules, lobectomy was less costly and more effective than Afirma® (lobectomy: $6,100; 4.50 quality-adjusted life- years vs Afirma®: $9,400; 4.47 quality-adjusted life-years). Only in 253 of 10,000 simulations (2.5%) did Afirma® show a net benefit at a cost-effectiveness threshold of $100,000 per quality- adjusted life-years. There was only a 0.3% probability of Afirma® being cost saving and a 14.9% probability of improving quality-adjusted life-years. Our base case estimate suggests that diagnostic lobectomy dominates genetic testing as a strategy for ruling out malignancy of indeterminate thyroid nodules. These results, however, were highly sensitive to estimates of utilities after lobectomy and living under surveillance after Afirma®. Published by Elsevier Inc.

Indeterminate RIBA results were associated with the absence of hepatitis C virus RNA (HCV-RNA) in blood donors.

PubMed

Pereira, Felicidade Mota; Zarife, Maria Alice Sant'ana; Reis, Eliana Almeida Gomes; G Reis, Mitermayer

2014-01-01

Hepatitis C virus (HCV) infection is diagnosed by the presence of antibodies and is supplemented by confirmatory testing methods, such as recombinant immunoblot assay (RIBA) and HCV-RNA detection. This study aimed to evaluate the efficacy of RIBA testing to diagnose HCV infection in blood donors positive for anti-HCV antibodies. A total of 102 subjects positive for anti-HCV determined by enzyme-linked immunosorbent assay (ELISA) at the Hematology and Hemotherapy Foundation of Bahia (HEMOBA) were later assessed with new samples using the Abbott Architect anti-HCV test (Abbott Diagnostics, Wiesbaden, Germany), the RIBA III test (Chiron RIBA HCV 3.0 SIA, Chiron Corp., Emeryville, CA, USA), the polymerase chain reaction (PCR; COBAS® AMPLICOR HCV Roche Diagnostics Corp., Indianapolis, IN, USA) and line probe assay (LiPA - Siemens, Tarrytown, NY, USA) genotyping for HCV diagnosis. Of these new samples, 38.2% (39/102) were positive, 57.8% (59/102) were negative and 3.9% (4/102) were indeterminate for anti-HCV; HCV-RNA was detected in 22.5% (23/102) of the samples. RIBA results were positive in 58.1% (25/43), negative in 9.3% (4/43) and indeterminate in 32.6% (14/43) of the samples. The prevailing genotypes were 1 (78.3%, 18/23), 3 (17.4%, 4/23) and 2 (4.3%, 1/23). All 14 samples with indeterminate RIBA results had undetectable viral loads (detection limit ≤50 IU/mL). Of these samples, 71.4% (10/14) were reevaluated six months later. Eighty percent (8/10) of these samples remained indeterminate by RIBA, and 20% (2/10) were negative. In this study, individuals with indeterminate RIBA results had no detectable HCV-RNA.

A Historical Overview and Contemporary Expansion of Psychological Theories of Determinism, Probabilistic Causality, Indeterminate Free Will, and Moral and Legal Responsibility

ERIC Educational Resources Information Center

Wilks, Duffy; Ratheal, Juli D'Ann

2009-01-01

The authors provide a historical overview of the development of contemporary theories of counseling and psychology in relation to determinism, probabilistic causality, indeterminate free will, and moral and legal responsibility. They propose a unique model of behavioral causality that incorporates a theory of indeterminate free will, a concept…

Indetermination of particle sizing by laser diffraction in the anomalous size ranges

NASA Astrophysics Data System (ADS)

Pan, Linchao; Ge, Baozhen; Zhang, Fugen

2017-09-01

The laser diffraction method is widely used to measure particle size distributions. It is generally accepted that the scattering angle becomes smaller and the angles to the location of the main peak of scattered energy distributions in laser diffraction instruments shift to smaller values with increasing particle size. This specific principle forms the foundation of the laser diffraction method. However, this principle is not entirely correct for non-absorbing particles in certain size ranges and these particle size ranges are called anomalous size ranges. Here, we derive the analytical formulae for the bounds of the anomalous size ranges and discuss the influence of the width of the size segments on the signature of the Mie scattering kernel. This anomalous signature of the Mie scattering kernel will result in an indetermination of the particle size distribution when measured by laser diffraction instruments in the anomalous size ranges. By using the singular-value decomposition method we interpret the mechanism of occurrence of this indetermination in detail and then validate its existence by using inversion simulations.

The limits of predictability: Indeterminism and undecidability in classical and quantum physics

NASA Astrophysics Data System (ADS)

Korolev, Alexandre V.

This thesis is a collection of three case studies, investigating various sources of indeterminism and undecidability as they bear upon in principle unpredictability of the behaviour of mechanistic systems in both classical and quantum physics. I begin by examining the sources of indeterminism and acausality in classical physics. Here I discuss the physical significance of an often overlooked and yet important Lipschitz condition, the violation of which underlies the existence of anomalous non-trivial solutions in the Norton-type indeterministic systems. I argue that the singularity arising from the violation of the Lipschitz condition in the systems considered appears to be so fragile as to be easily destroyed by slightly relaxing certain (infinite) idealizations required by these models. In particular, I show that the idealization of an absolutely nondeformable, or infinitely rigid, dome appears to be an essential assumption for anomalous motion to begin; any slightest elastic deformations of the dome due to finite rigidity of the dome destroy the shape of the dome required for indeterminism to obtain. I also consider several modifications of the original Norton's example and show that indeterminism in these cases, too, critically depends on the nature of certain idealizations pertaining to elastic properties of the bodies in these models. As a result, I argue that indeterminism of the Norton-type Lipschitz-indeterministic systems should rather be viewed as an artefact of certain (infinite) idealizations essential for the models, depriving the examples of much of their intended metaphysical import, as, for example, in Norton's antifundamentalist programme. Second, I examine the predictive computational limitations of a classical Laplace's demon. I demonstrate that in situations of self-fulfilling prognoses the class of undecidable propositions about certain future events, in general, is not empty; any Laplace's demon having all the information about the world now

Factors That Contribute to Indeterminate Results From the QuantiFERON-TB Gold In-Tube Test in Patients With Inflammatory Bowel Disease.

PubMed

Kaur, Manreet; Singapura, Prianka; Kalakota, Neeharika; Cruz, Guillermina; Shukla, Richa; Ahsan, Sidra; Tansel, Aylin; Thrift, Aaron P; El-Serag, Hashem B

2017-11-23

The QuantiFERON-Tuberculosis Gold In-Tube (QFT-GIT) (QIAGEN Group, Hilden, Germany) test is widely used to screen for latent Mycobacterium tuberculosis infection in patients with inflammatory bowel diseases (IBD) before treatment with a tumor necrosis factor antagonist. The test frequently produces indeterminate results, prompting additional testing. We evaluated factors associated with indeterminate results from the QFT-GIT test among patients with IBD. We conducted a case-control study among eligible adults with QFT-GIT test results and a concomitant diagnosis of IBD receiving care at a tertiary referral center from 2011 through 2013. We compared patients with IBD with indeterminate and determinate (positive or negative) results from the QFT-GIT test. We collected data on patient demographics, clinical features, laboratory parameters, and medication use from medical charts. We calculated odds ratios (OR) and 95% CIs using multivariate logistic regression models. A total of 400 patients with IBD (265 Crohn's disease and 135 ulcerative colitis) were included in the final analyses. Indeterminate results were noted in 11.5% of patients. At the time of testing, a higher proportion of patients with indeterminate results from the QFT-GIT test were on systemic corticosteroid therapy (60.9% vs 30.5% of patients with conclusive test results; P < .001), had levels of C-reactive protein above 0.8 mg (62.2% vs 39.9% of patients with clear test results; P = .005), had an erythrocyte sedimentation rate above 15 mm/h (55.6% vs 35.8% of patients with clear test results; P = .01), had serum levels of albumin below 3.5 g/dL (33.3% vs 6.3% of patients with clear test results; P < .001), and had low levels of hemoglobin (52.2% vs 28.3% of patients with clear test results; P = .001). In multivariable analysis, corticosteroid use (adjusted OR, 2.92; 95% CI, 1.44-5.88; P = .003) and serum levels of albumin below 3.5 g/dL (adjusted OR, 3.62; 95% CI, 1.36-9.60; P = .009) were

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.

Frequency of indeterminate results from an interferon-gamma release assay among HIV-infected individuals.

PubMed

Oliveira, Sandra Maria do Valle Leone de; Trajman, Anete; Paniago, Anamaria Mello Miranda; Motta-Castro, Ana Rita Coimbra; Ruffino-Netto, Antonio; Maciel, Ethel Leonor Noia; Croda, Julio; Bonecini-Almeida, Maria da Gloria

2017-01-01

To evaluate the frequency of and factors associated with indeterminate interferon-gamma release assay (IGRA) results in people living with HIV/AIDS (PLWHA). We tested 81 PLWHA in the central-west region of Brazil, using the tuberculin skin test and an IGRA. Information on sociodemographic and clinical variables was gathered through the use of questionnaires and from medical records. The association of those variables with indeterminate results was analyzed by calculating the adjusted ORs in a multivariate logistic regression model. Concordance was evaluated by determining the kappa statistic. Among the 81 patients evaluated, the tuberculin skin test results were positive in 18 (22.2%) of the patients, and the IGRA results were positive in 10 (12.3%), with a kappa of 0.62. The IGRA results were indeterminate in 22 (27.1%) of the patients (95% CI: 17.8-38.1%). The odds of obtaining indeterminate results were significantly higher in smokers (adjusted OR = 6.0; 95% CI: 1.4-26.7) and in samples stored for less than 35 days (adjusted OR = 14.0; 95% CI: 3.1-64.2). Patients with advanced immunosuppression (CD4+ T-cell count < 200 cells/mm3) were at a higher risk for indeterminate results (OR adjusted for smoking and inadequate duration of sample storage = 4.7; 95% CI: 0.91-24.0), although the difference was not significant. The high prevalence of indeterminate results can be a major limitation for the routine use of IGRAs in PLWHA. The need to repeat the test increases its costs and should be taken into account in cost-effectiveness studies. The processing of samples can significantly alter the results. Avaliar a frequência de resultados indeterminados de um interferon-gamma release assay (IGRA, ensaio de liberação de interferon-gama) e os fatores relacionados com esses resultados em pessoas vivendo com HIV/AIDS (PVHA). Foram avaliadas 81 PVHA na região Centro-Oeste do Brasil, por meio do teste tuberculínico e de um IGRA. Informações a respeito de vari

Reasons Associated with Total Thyroidectomy as Initial Surgical Management of an Indeterminate Thyroid Nodule.

PubMed

Angell, Trevor E; Vyas, Chirag M; Barletta, Justine A; Cibas, Edmund S; Cho, Nancy L; Doherty, Gerard M; Gawande, Atul A; Howitt, Brooke E; Krane, Jeffrey F; Marqusee, Ellen; Strickland, Kyle C; Alexander, Erik K; Moore, Francis D; Nehs, Matthew A

2018-05-01

Diagnostic hemithyroidectomy (HT) is the most widely recommended surgical procedure for a nodule with indeterminate cytology; however, additional details may make initial total thyroidectomy (TT) preferable. We sought to identify patient-specific factors (PSFs) associated with initial TT in patients with indeterminate thyroid nodules. Retrospective analysis of all patients with a thyroid nodule ≥ 1 cm and initial cytology of atypia of undetermined significance or suspicious for follicular neoplasm between 2012 and 2015 who underwent thyroidectomy. Medical records were reviewed for patient demographics, neck symptoms, nodule size, cytology, molecular test results, final histopathology, and additional PSFs influencing surgical management. Variables were analyzed to determine associations with the use of initial TT. Logistic regression analyses were performed to identify independent associations. Of 325 included patients, 182/325 (56.0%) had HT and 143/325 (44.0%) had TT. While patient age and sex, nodule size, and cytology result were not associated with initial treatment, five PSFs were associated with initial TT (p < 0.0001). These included contralateral nodules, hypothyroidism, fluorodeoxyglucose avidity on positron emission tomography scan, family history of thyroid cancer, and increased surgical risk. At least one PSF was present in 126/143 (88.1%) TT patients versus 47/182 (25.8%) HT patients (p < 0.0001). Multivariate logistic regression analysis demonstrated that these variables were the strongest independent predictor of TT (odds ratio 45.93, 95% confidence interval 18.80-112.23, p < 0.001). When surgical management of an indeterminate cytology thyroid nodule was performed, several PSFs were associated with a preference by surgeons and patients for initial TT, which may be useful to consider in making decisions on initial operative extent.

Low Indeterminate Rates Associated With Use of the QuantiFERON-TB Gold In-Tube Test in Children With Inflammatory Bowel Disease on Long-term Infliximab.

PubMed

Vortia, Eugene; Uko, Victor E; Yen-Lieberman, Belinda; Frawley, Jill; Worley, Sarah E; Danziger-Isakov, Lara; Kaplan, Barbara; Mahajan, Lori

2018-03-19

Tumor necrosis factor alpha (TNF-α) inhibitors are linked with increased risk of reactivation of active tuberculosis. The QuantiFERON-TB Gold In-Tube test is approved for screening latent tuberculosis infection in children and adults. There are limited data on the test performance in children on long-term treatment with TNF-α inhibitors. The objective of this study was to assess the proportion of indeterminate results for the QuantiFERON-TB Gold In-Tube in children with inflammatory bowel disease (IBD) on long-term infliximab treatment and to evaluate the range of interferon-γ responses to mitogen. A single-center prospective study of children 5 to 19 years of age with IBD on long-term infliximab treatment (>3 months). Each child was assessed for tuberculosis exposure risk and had blood drawn for the QuantiFERON-TB Gold In-Tube. Data on the range of interferon-γ responses and final QuantiFERON-TB Gold In-Tube test results were collected. Ninety-three children were included, with a median age of 16 years. The median total duration of infliximab therapy was 34 months (range, 3-119 months). The QuantiFERON-TB Gold In-Tube was indeterminate in 1 patient (1.1%), positive in 2 patients, and negative in 90 patients. The maximum interferon-γ response to mitogen (10 IU/mL) was observed in 82 patients (88%), with only 1 patient having an inadequate response. The proportion of indeterminate results was significantly lower than the prospectively hypothesized rate of 8%, based on prior studies in nonimmunosuppressed patients (P = 0.004). Pediatric patients with IBD on long-term treatment with infliximab had an adequate interferon-γ response to mitogen and a low indeterminate rate when assessed with the QuantiFERON-TB Gold In-Tube test. This study demonstrates a robust interferon gamma response to phytohemagglutinin stimulation in a pediatric population on long-term therapy with infliximab. The QuantiFERON-TB Gold In-Tube test may therefore be useful as a periodic

F-actin and microtubule suspensions as indeterminate fluids.

PubMed

Buxbaum, R E; Dennerll, T; Weiss, S; Heidemann, S R

1987-03-20

The viscosity of F-actin and microtubule suspensions has been measured as a function of shear rate with a Weissenberg rheogoniometer. At shear rates of less than 1.0 per second the viscosity of suspensions of these two structural proteins is inversely proportional to shear rate. These results are consistent with previous in vivo measurements of the viscosity of cytoplasm. This power law implies that shear stress is independent of shear rate; that is, shear stress is a constant at all shear rates less than 1.0 per second. Thus the flow profile of these fluids is indeterminate, or nearly so. This flow property may explain several aspects of intracellular motility in living cells. Possible explanations for this flow property are based on a recent model for semidilute suspensions of rigid rods or a classical friction model for liquid crystals.

Integrated Force Method for Indeterminate Structures

NASA Technical Reports Server (NTRS)

Hopkins, Dale A.; Halford, Gary R.; Patnaik, Surya N.

2008-01-01

Two methods of solving indeterminate structural-mechanics problems have been developed as products of research on the theory of strain compatibility. In these methods, stresses are considered to be the primary unknowns (in contrast to strains and displacements being considered as the primary unknowns in some prior methods). One of these methods, denoted the integrated force method (IFM), makes it possible to compute stresses, strains, and displacements with high fidelity by use of modest finite-element models that entail relatively small amounts of computation. The other method, denoted the completed Beltrami Mitchell formulation (CBMF), enables direct determination of stresses in an elastic continuum with general boundary conditions, without the need to first calculate displacements as in traditional methods. The equilibrium equation, the compatibility condition, and the material law are the three fundamental concepts of the theory of structures. For almost 150 years, it has been commonly supposed that the theory is complete. However, until now, the understanding of the compatibility condition remained incomplete, and the compatibility condition was confused with the continuity condition. Furthermore, the compatibility condition as applied to structures in its previous incomplete form was inconsistent with the strain formulation in elasticity.

Q-elastography in the presurgical diagnosis of thyroid nodules with indeterminate cytology.

PubMed

Cantisani, Vito; Ulisse, Salvatore; Guaitoli, Eleonora; De Vito, Corrado; Caruso, Riccardo; Mocini, Renzo; D'Andrea, Vito; Ascoli, Valeria; Antonaci, Alfredo; Catalano, Carlo; Nardi, Francesco; Redler, Adriano; Ricci, Paolo; De Antoni, Enrico; Sorrenti, Salvatore

2012-01-01

Quantitative ultrasound (US) elastography (Q-USE), able to evaluate tissue stiffness has been indicated as a new diagnostic tool to differentiate benign from malignant thyroid lesions. Aim of this prospective study, conducted at the Department of Surgical Sciences, of the "Sapienza" University of Rome, was to evaluate the diagnostic accuracy of Q-USE, compared with US parameters, in thyroid nodules with indeterminate cytology (Thy3).The case study included 140 nodules from 140 consecutive patients. Patient's thyroid nodules were evaluated by Q-USE, measuring the strain ratio (SR) of stiffness between nodular and surrounding normal thyroid tissue, and conventional US parameters prior fine-needle aspiration cytology. Those with Thy3 diagnosis were included in the study. Forty of the nodules analyzed harbored a malignant lesion. Q-USE demonstrated that malignant nodules have a significant higher stiffness with respect to benign one and an optimun SR cut-off value of 2.05 was individuated following ROC analysis. Univariate analysis showed that hypoechogenicity, irregular margins and SR >2.05 associated with malignancy, with an accuracy of 67.2%, 81,0% and 89.8%, respectively. Data were unaffected by nodule size or thyroiditis. These findings were confirmed in multivariate analysis demonstrating a significant association of the SR and the irregular margins with thyroid nodule's malignancy. In conclusion, we demonstrated the diagnostic utility of Q-USE in the differential diagnosis of thyroid nodules with indeterminate cytology that, if confirmed, could be of major clinical utility in patients' presurgical selection.

Using Menelaus' Theorem and Dynamic Mathematics Software to Convey the Meanings of Indeterminate Forms to Students

ERIC Educational Resources Information Center

Çekmez, Erdem

2016-01-01

This study investigates the effectiveness of a teaching activity that aimed to convey the meaning of indeterminate forms to a group of undergraduate students who were enrolled in an elementary mathematics education programme. The study reports the implementation sequence of the activity and students' experiences in the classroom. To assess the…

Chronic indeterminate phase of Chagas' disease: mitochondrial involvement in infection with two strains.

PubMed

Báez, Alejandra Lidia; Lo Presti, María Silvina; Fretes, Ricardo; Díaz, Cintia; Pons, Patricia; Bazán, Paola Carolina; Strauss, Mariana; Rivarola, Héctor Walter; Paglini-Oliva, Patricia

2013-03-01

Chagasic cardiopathy has become one of the most frequent causes of heart failure and sudden death, as well as one of the most common causes of cardio-embolic stroke in Latin America. The myocyte response to oxidative stress involves the progression of cellular changes, primarily targeting the mitochondria and modifying therefore the energy supply. In this paper we analysed the effect of the infection of mice with 2 different strains of Trypanosoma cruzi (Tulahuen and SGO Z12) in the chronic indeterminate stage (75 days post-infection), upon the structure and function of cardiac mitochondria. The structural results showed that 83% of the mitochondria from the Tulahuen-infected mice presented an increase in their matrix and 91% of the mitochondria from the SGO Z12-infected group showed a reduction in their diameter (P < 0.05). When the Krebs cycle and mitochondrial respiratory chain functionality was analysed through the measurement of the citrate synthase and complexes I to IV activity, it showed that their activity was altered in all cases in a similar manner in both infected groups. In this paper we have demonstrated that the chronic indeterminate phase is not 'silent' and that cardiac mitochondria are clearly involved in the genesis and progression to the chronic chagasic cardiopathy when different factors alter the host-parasite equilibrium.

Evaluation of inadequate, indeterminate, false-negative and false-positive cases in cytological examination for breast cancer according to histological type

PubMed Central

2012-01-01

Background We previously investigated the current status of breast cytology cancer screening at seven institutes in our area of southern Fukuoka Prefecture, and found some differences in diagnostic accuracy among the institutions. In the present study, we evaluated the cases involved and noted possible reasons for their original cytological classification as inadequate, indeterminate, false-negative and false-positive according to histological type. Methods We evaluated the histological findings in 5693 individuals who underwent cytological examination for breast cancer (including inadequate, indeterminate, false-negative and false-positive cases), to determine the most common histological types and/or features in these settings and the usefulness/limitations of cytological examination for the diagnosis of breast cancer. Results Among 1152 cytologically inadequate cases, histology revealed that 75/173 (43.6%) cases were benign, including mastopathy (fibrocystic disease) in 38.6%, fibroadenoma in 24.0% and papilloma in 5.3%. Ninety-five of 173 (54.9%) cases were histologically malignant, with scirrhous growing type, invasive ductal carcinoma (SIDC) being significantly more frequent (49.5%) than papillotubular growing type (Papi-tub) (P < 0.0001), solid-tubular growing type (P = 0.0001) and ductal carcinoma in situ (DCIS) (P = 0.0001). Among 458 indeterminate cases, 54/139 (38.8%) were histologically benign (mastopathy, 30.0%; fibroadenoma, 27.8%; papilloma, 26.0%) and 73/139 (52.5%) were malignant, with SIDC being the most frequent malignant tumor (37.0%). Among 52 false-negative cases, SIDC was significantly more frequent (42.3%) than DCIS (P = 0.0049) and Papi-tub (P = 0.001). There were three false-positive cases, with one each of fibroadenoma, epidermal cyst and papilloma. Conclusions The inadequate, indeterminate, false-negative and false-positive cases showed similar histological types, notably SIDC for malignant tumors, and mastopathy

MRI of suspected appendicitis during pregnancy: interradiologist agreement, indeterminate interpretation and the meaning of non-visualization of the appendix.

PubMed

Tsai, Richard; Raptis, Constantine; Fowler, Kathryn J; Owen, Joseph W; Mellnick, Vincent M

2017-11-01

To determine the degree of interradiologist agreement between the MRI features of appendicitis during pregnancy, the outcomes associated with an indeterminate interpretation and the negative predictive value of non-visualization of the appendix. Our study was approved by the institutional review board at the Washington University in St. Louis, Missouri (WUStL) and was HIPAA (Health Insurance Portability and Accountability Act of 1996)-compliant. The informed consent requirement was waived. Cases of suspected appendicitis during pregnancy evaluated using MRI were retrospectively identified using search queries. Scans were re-reviewed by two radiologists (7 and 9 years experience, respectively) to evaluate the interradiologist agreement of different MRI features of appendicitis during pregnancy (visualization of the appendix, appendiceal diameter, appendiceal wall thickening, periappendiceal fat stranding, fluid-filled appendix and periappendiceal fluid). The radiologists were blinded to patient outcome, patient intervention, laboratory data, demographic data and the original MRI reports. Clinical outcomes were documented by surgical pathology or clinical observation. Interradiologist agreement was analysed using Cohen's κ, while patient demographic and clinical data was analysed using Student's t-testing. 233 females with suspected appendicitis during pregnancy were evaluated using MRI over a 13-year period (mean age, 28.4 years; range, 17-38 years). There were 14 (6%) positive examinations for appendicitis during pregnancy, including 1 patient whose MRI was interpreted as negative, proven by surgical pathology. The presence of periappendiceal soft-tissue stranding and the final overall impression had the most interradiologist agreement (к = 0.81-1). There were no pregnant patients found to have acute appendicitis who had an indeterminate MR interpretation or when the appendix could not be visualized. The final impression by the two retrospectively reviewing

Habitat structure and body size distributions: Cross-ecosystem comparison for taxa with determinate and indeterminate growth

USGS Publications Warehouse

Nash, Kirsty L.; Allen, Craig R.; Barichievy, Chris; Nystrom, Magnus; Sundstrom, Shana M.; Graham, Nicholas A.J.

2014-01-01

Habitat structure across multiple spatial and temporal scales has been proposed as a key driver of body size distributions for associated communities. Thus, understanding the relationship between habitat and body size is fundamental to developing predictions regarding the influence of habitat change on animal communities. Much of the work assessing the relationship between habitat structure and body size distributions has focused on terrestrial taxa with determinate growth, and has primarily analysed discontinuities (gaps) in the distribution of species mean sizes (species size relationships or SSRs). The suitability of this approach for taxa with indeterminate growth has yet to be determined. We provide a cross-ecosystem comparison of bird (determinate growth) and fish (indeterminate growth) body mass distributions using four independent data sets. We evaluate three size distribution indices: SSRs, species size–density relationships (SSDRs) and individual size–density relationships (ISDRs), and two types of analysis: looking for either discontinuities or abundance patterns and multi-modality in the distributions. To assess the respective suitability of these three indices and two analytical approaches for understanding habitat–size relationships in different ecosystems, we compare their ability to differentiate bird or fish communities found within contrasting habitat conditions. All three indices of body size distribution are useful for examining the relationship between cross-scale patterns of habitat structure and size for species with determinate growth, such as birds. In contrast, for species with indeterminate growth such as fish, the relationship between habitat structure and body size may be masked when using mean summary metrics, and thus individual-level data (ISDRs) are more useful. Furthermore, ISDRs, which have traditionally been used to study aquatic systems, present a potentially useful common currency for comparing body size distributions

Surgical management of benign and indeterminate hepatic lesions in the era of laparoscopic liver surgery.

PubMed

Abu Hilal, Mohammed; Di Fabio, Francesco; Teng, Mabel Joey; Godfrey, Dean Anthony; Primrose, John Neil; Pearce, Neil William

2011-01-01

The expansion of the laparoscopic approach for the management of benign liver lesions has raised concerns regarding the risk of widening surgical indications and compromising safety. Large single-centre series focusing on laparoscopic management of benign liver lesions are sporadic. We reviewed a prospectively collected database of patients undergoing pure laparoscopic liver resection (LLR) for benign liver lesions. All cases were individually discussed at a multidisciplinary team meeting. Forty-six patients underwent 50 LLRs for benign disease. Indications for surgery were: symptomatic lesions, preoperative diagnosis of adenoma or cystadenoma, and lesions with an indeterminate diagnosis. The preoperative diagnosis was uncertain in 11 cases. Of these, histological diagnosis was hepatocellular carcinoma in one (9%) and benign lesion in 10 patients (91%). Thirteen patients (28%) required major hepatectomy. Three patients (7%) developed postoperative complications. Mortality was nil. The median postoperative hospital stay following major and minor hepatectomy was 4 and 3 days, respectively. The laparoscopic approach represents a safe option for the management of benign and indeterminate liver lesions, even when major hepatectomy is required. LLR should be only performed in specialized centres to ensure safety and strict adherence to orthodox surgical indication. Copyright © 2011 S. Karger AG, Basel.

Seroprevalence, cost per donation and reduction in blood supply due to positive and indeterminate results for infectious markers in a blood bank in Lima, Peru.

PubMed

Moya-Salazar, Jeel; Ubidia-Incio, Roberto; Incio-Grande, Maritza; Blejer, Jorgelina L; Gonzalez, Carlos A

Safety in Transfusion Medicine is subject to regulations and government legislation within a total quality framework. The aim of this study was to evaluate the impact of seroprevalence and indeterminate results on lost units and cost per donation. A prospective cross-sectional study was performed in the Blood Bank and Transfusion Therapy Department of the Hospital Central de la Policia Nacional del Perú in Lima, Peru. All completed donations (replacement/voluntary) without complications were included in this study. Every donation met the institutional requirements and quality criteria of Programa Nacional de Hemoterapia y Bancos de Sangre (PRONAHEBAS). Data analysis was achieved using the Statistical Package for the Social Sciences. A total of 7723 donations were evaluated during 2014 and 2015 with 493 being seropositive (overall prevalence 5.25%) and 502 having indeterminate results (overall prevalence 5.35%). Thus total loss was 995units, 437.8L of blood and 49,750 US dollars. The most common seropositive infectious markers were the core antibody of hepatitis B virus (2.82%) and syphilis (1.02%), and the most common indeterminate results were Chagas disease (1.27%) and the core antibody of hepatitis B virus (1.26%). There was no significant change in the prevalence of seropositivity (p-value=0.243) or indeterminate results (p-value=0.227) over the two-year period of the study. A statistical correlation was found between the cost per lost donation and the most prevalent markers (rho=0.848; p-value=<0.001). Seroprevalence was lower than the regional mean, but the prevalence of indeterminate results was elevated causing a great impact on blood supply and economic losses to this institution. Copyright © 2017 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier Editora Ltda. All rights reserved.

Q-Elastography in the Presurgical Diagnosis of Thyroid Nodules with Indeterminate Cytology

PubMed Central

Guaitoli, Eleonora; De Vito, Corrado; Caruso, Riccardo; Mocini, Renzo; D’Andrea, Vito; Ascoli, Valeria; Antonaci, Alfredo; Catalano, Carlo; Nardi, Francesco; Redler, Adriano; Ricci, Paolo; De Antoni, Enrico; Sorrenti, Salvatore

2012-01-01

Quantitative ultrasound (US) elastography (Q-USE), able to evaluate tissue stiffness has been indicated as a new diagnostic tool to differentiate benign from malignant thyroid lesions. Aim of this prospective study, conducted at the Department of Surgical Sciences, of the “Sapienza” University of Rome, was to evaluate the diagnostic accuracy of Q-USE, compared with US parameters, in thyroid nodules with indeterminate cytology (Thy3).The case study included 140 nodules from 140 consecutive patients. Patient’s thyroid nodules were evaluated by Q-USE, measuring the strain ratio (SR) of stiffness between nodular and surrounding normal thyroid tissue, and conventional US parameters prior fine-needle aspiration cytology. Those with Thy3 diagnosis were included in the study. Forty of the nodules analyzed harbored a malignant lesion. Q-USE demonstrated that malignant nodules have a significant higher stiffness with respect to benign one and an optimun SR cut-off value of 2.05 was individuated following ROC analysis. Univariate analysis showed that hypoechogenicity, irregular margins and SR >2.05 associated with malignancy, with an accuracy of 67.2%, 81,0% and 89.8%, respectively. Data were unaffected by nodule size or thyroiditis. These findings were confirmed in multivariate analysis demonstrating a significant association of the SR and the irregular margins with thyroid nodule’s malignancy. In conclusion, we demonstrated the diagnostic utility of Q-USE in the differential diagnosis of thyroid nodules with indeterminate cytology that, if confirmed, could be of major clinical utility in patients’ presurgical selection. PMID:23209819

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.

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.

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.

Indeterminate cell histiocytosis in a pediatric patient: successful treatment with thalidomide.

PubMed

Tóth, Béla; Katona, Mária; Hársing, Judit; Szepesi, Agota; Kárpáti, Sarolta

2012-04-01

The 15-year-old male patient presented several 2-6 mm large livid reddish-yellowish, shiny, compact papules on the head, trunk and extremities, which had developed within the last 4 months. Histology showed normal epidermis with dense dermal infiltrate of histiocytes accompanied by few eosinophils, Touton or foamy giant cells. The histiocytes were S100 positive, CD1a negative and did not contain Birbeck granules ultrastructurally. Chest X ray, EEG, skull MRI did not show pathology. Opthalmology, neurology, oto-rhino-laryngology did not reveal alterations. Based upon the clinical symptoms and the histopathology, the diagnosis of indeterminate cell histiocytosis was confirmed. Cryotherapy and cauterization did not stop the progression of the disease, however, under thalidomide treatment no new symptoms developed and the lesions healed with pigmentation.

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.

'The thing is not knowing': patients' perspectives on surveillance of an indeterminate pulmonary nodule.

PubMed

Wiener, Renda Soylemez; Gould, Michael K; Woloshin, Steven; Schwartz, Lisa M; Clark, Jack A

2015-06-01

The hundreds of thousands of patients found to have a potentially malignant pulmonary nodule each year are faced with tremendous uncertainty regarding what the nodule is and how it should be evaluated. To explore patients' responses to the detection and evaluation of a pulmonary nodule. Qualitative study based on four focus-group discussions. We performed inductive analysis using principles of grounded theory to identify themes relating to responses to the nodule and strategies to manage uncertainty. Twenty-two patients from two medical centres who were undergoing surveillance for an indeterminate pulmonary nodule. Patient responses to an indeterminate pulmonary nodule were varied and evolved over time. Although almost all patients reported an initial fear about cancer, subsequent depictions of the nodule diverged into four types defined on two dimensions: cognitive ('it's cancer' vs. 'I don't know what it is' vs. 'it's nothing serious') and emotional (anxiety vs. equanimity). Most eventually accepted that the nodule was unlikely to be malignant; however, some remained anxious, convinced the nodule could turn into cancer at any time and should be aggressively monitored for life. Patients used results of surveillance tests as well as their own strategies (e.g. vigilance for symptoms, information-seeking, contemplating and controlling modifiable risk factors, avoidance, faith) to manage uncertainty. Surveillance for a pulmonary nodule can weigh heavily on some patients for months or years. Our findings may help clinicians prepare patients with a newly detected pulmonary nodule for the burden of the prolonged uncertainty of surveillance. © 2012 Blackwell Publishing Ltd.

Asymmetric interaction and indeterminate fitness correlation between cooperative partners in the fig–fig wasp mutualism

PubMed Central

Wang, Rui-Wu; Sun, Bao-Fa; Zheng, Qi; Shi, Lei; Zhu, Lixing

2011-01-01

Empirical observations have shown that cooperative partners can compete for common resources, but what factors determine whether partners cooperate or compete remain unclear. Using the reciprocal fig–fig wasp mutualism, we show that nonlinear amplification of interference competition between fig wasps—which limits the fig wasps' ability to use a common resource (i.e. female flowers)—keeps the common resource unsaturated, making cooperation locally stable. When interference competition was manually prevented, the fitness correlation between figs and fig wasps went from positive to negative. This indicates that genetic relatedness or reciprocal exchange between cooperative players, which could create spatial heterogeneity or self-restraint, was not sufficient to maintain stable cooperation. Moreover, our analysis of field-collected data shows that the fitness correlation between cooperative partners varies stochastically, and that the mainly positive fitness correlation observed during the warm season shifts to a negative correlation during the cold season owing to an increase in the initial oviposition efficiency of each fig wasp. This implies that the discriminative sanction of less-cooperative wasps (i.e. by decreasing the egg deposition efficiency per fig wasp) but reward to cooperative wasps by fig, a control of the initial value, will facilitate a stable mutualism. Our finding that asymmetric interaction leading to an indeterminate fitness interaction between symbiont (i.e. cooperative actors) and host (i.e. recipient) has the potential to explain why conflict has been empirically observed in both well-documented intraspecific and interspecific cooperation systems. PMID:21490005

Comparison of Accuracy Between 13C- and 14C-Urea Breath Testing: Is an Indeterminate-Results Category Still Needed?

PubMed

Charest, Mathieu; Bélair, Marc-André

2017-06-01

Helicobacter pylori infection is the leading cause of peptic ulcer disease. The purpose of this study was, first, to assess the difference in the distribution of negative versus positive results between the older 14 C-urea breath test and the newer 13 C-urea breath test and, second, to determine whether use of an indeterminate-results category is still meaningful and what type of results should trigger repeated testing. Methods: A retrospective survey was performed of all consecutive patients referred to our service for urea breath testing. We analyzed 562 patients who had undergone testing with 14 C-urea and 454 patients who had undergone testing with 13 C-urea. Results: In comparison with the wide distribution of negative 14 C results, negative 13 C results were distributed farther from the cutoff and were grouped more tightly around the mean negative value. Distribution analysis of the negative results for 13 C testing, compared with those for 14 C testing, revealed a statistically significant difference between the two. Within the 13 C group, only 1 patient could have been classified as having indeterminate results using the same indeterminate zone as was used for the 14 C group. This is significantly less frequent than what was found for the 14 C group. Discussion: Borderline-negative results do occur with 13 C-urea breath testing, although less frequently than with 14 C-urea breath testing, and we will be carefully monitoring differences falling between 3.0 and 3.5 %Δ. 13 C-urea breath testing is safe and simple for the patient and, in most cases, provides clearer positive or negative results for the clinician. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Radiological indeterminate vestibular schwannoma and meningioma in cerebellopontine angle area: differentiating using whole-tumor histogram analysis of apparent diffusion coefficient.

PubMed

Xu, Xiao-Quan; Li, Yan; Hong, Xun-Ning; Wu, Fei-Yun; Shi, Hai-Bin

2017-02-01

To assess the role of whole-tumor histogram analysis of apparent diffusion coefficient (ADC) maps in differentiating radiological indeterminate vestibular schwannoma (VS) from meningioma in cerebellopontine angle (CPA). Diffusion-weighted (DW) images (b = 0 and 1000 s/mm 2 ) of pathologically confirmed and radiological indeterminate CPA meningioma (CPAM) (n = 27) and VS (n = 12) were retrospectively collected and processed with mono-exponential model. Whole-tumor regions of interest were drawn on all slices of the ADC maps to obtain histogram parameters, including the mean ADC (ADC mean ), median ADC (ADC median ), 10th/25th/75th/90th percentile ADC (ADC 10 , ADC 25 , ADC 75 and ADC 90 ), skewness and kurtosis. The differences of ADC histogram parameters between CPAM and VS were compared using unpaired t-test. Multiple receiver operating characteristic (ROC) curves analysis was used to determine and compare the diagnostic value of each significant parameter. Significant differences were found on the ADC mean , ADC median , ADC 10 , ADC 25 , ADC 75 and ADC 90 between CPAM and VS (all p values < 0.001), while no significant difference was found on kurtosis (p = 0.562) and skewness (p = 0.047). ROC curves analysis revealed, a cut-off value of 1.126 × 10 -3 mm 2 /s for the ADC 90 value generated highest area under curves (AUC) for differentiating CPAM from VS (AUC, 0.975; sensitivity, 100%; specificity, 88.9%). Histogram analysis of ADC maps based on whole tumor can be a useful tool for differentiating radiological indeterminate CPAM from VS. The ADC 90 value was the most promising parameter for differentiating these two entities.

The value of preoperative computed tomography combined with ultrasound in the investigation of small indeterminate liver lesions in patients with colorectal cancer.

PubMed

Abraham-Nordling, Mirna; Öistämö, Emma; Josephson, Thomas; Hjern, Fredrik; Blomqvist, Lennart

2017-11-01

Background Computed tomography (CT) is used routinely for the preoperative detection of colorectal cancer (CRC) metastases. When small indeterminate focal liver lesions are detected that are too small to characterize (TSTC) on CT, additional imaging is usually needed, resulting in a potential delay in obtaining a complete diagnostic work-up. Purpose To determine the diagnostic accuracy of ultrasound (US) of the liver performed in direct conjunction to CT in the preoperative investigation among patients with newly diagnosed CRC when indeterminate liver lesions were found on CT. Material and Methods Preoperative investigations with CT and consecutive US where CT had shown at least one focal liver lesion in 74 patients diagnosed with CRC between June 2009 and February 2012 were retrospectively reviewed. Either histopathological findings or a combination of imaging and clinical follow-up one to three years after surgery was used as the reference. Results Liver metastases were diagnosed with CT/US in 13 out of 74 patients (17.6%). In one patient, a liver cyst was preoperatively regarded as liver metastasis by a combined CT/US. The sensitivity and specificity for the CT with consecutive US procedure was 100% (13/13) and 98.4% (60/61). Conclusion US performed in conjunction with CT in patients with indeterminate focal liver lesions on CT is an accurate work-up for detection of liver metastases in patients with newly diagnosed CRC. Although our results are promising, they cannot be considered safely generalizable to all hospitals.

Circulating Plasma MicroRNA-208a as Potential Biomarker of Chronic Indeterminate Phase of Chagas Disease.

PubMed

Linhares-Lacerda, Leandra; Granato, Alessandra; Gomes-Neto, João Francisco; Conde, Luciana; Freire-de-Lima, Leonardo; de Freitas, Elisangela O; Freire-de-Lima, Celio G; Coutinho Barroso, Shana P; Jorge de Alcântara Guerra, Rodrigo; Pedrosa, Roberto C; Savino, Wilson; Morrot, Alexandre

2018-01-01

Chagas cardiomyopathy is the most severe clinical manifestation of chronic Chagas disease. The disease affects most of the Latin American countries, being considered one of the leading causes of morbidity and death in the continent. The pathogenesis of Chagas cardiomyopathy is very complex, with mechanisms involving parasite-dependent cytopathy, immune-mediated myocardial damage and neurogenic disturbances. These pathological changes eventually result in cardiac myocyte hypertrophy, arrhythmias, congestive heart failure and stroke during chronic infection phase. Herein, we show that miR-208a, a microRNA that is a key factor in promoting cardiovascular dysfunction during cardiac hypertrophy processes of heart failure, has its circulating levels increased during chronic indeterminate phase when compared to cardiac (CARD) clinical forms in patients with Chagas disease. In contrast, we have not found altered serum levels of miR-34a, a microRNA known to promote pro-apoptotic role in myocardial infarction during degenerative process of cardiac injuries thus indicating intrinsic differences in the nature of the mechanisms underlying the heart failure triggered by Trypanosoma cruzi infection. Our findings support that the chronic indeterminate phase is a progressive phase involved in the genesis of chagasic cardiopathy and point out the use of plasma levels of miR-208a as candidate biomarker in risk-prediction score for the clinical prognosis of Chagas disease.

A 10-Gene Classifier for Indeterminate Thyroid Nodules: Development and Multicenter Accuracy Study

PubMed Central

González, Hernán E.; Martínez, José R.; Vargas-Salas, Sergio; Solar, Antonieta; Veliz, Loreto; Cruz, Francisco; Arias, Tatiana; Loyola, Soledad; Horvath, Eleonora; Tala, Hernán; Traipe, Eufrosina; Meneses, Manuel; Marín, Luis; Wohllk, Nelson; Diaz, René E.; Véliz, Jesús; Pineda, Pedro; Arroyo, Patricia; Mena, Natalia; Bracamonte, Milagros; Miranda, Giovanna; Bruce, Elsa

2017-01-01

Background: In most of the world, diagnostic surgery remains the most frequent approach for indeterminate thyroid cytology. Although several molecular tests are available for testing in centralized commercial laboratories in the United States, there are no available kits for local laboratory testing. The aim of this study was to develop a prototype in vitro diagnostic (IVD) gene classifier for the further characterization of nodules with an indeterminate thyroid cytology. Methods: In a first stage, the expression of 18 genes was determined by quantitative polymerase chain reaction (qPCR) in a broad histopathological spectrum of 114 fresh-tissue biopsies. Expression data were used to train several classifiers by supervised machine learning approaches. Classifiers were tested in an independent set of 139 samples. In a second stage, the best classifier was chosen as a model to develop a multiplexed-qPCR IVD prototype assay, which was tested in a prospective multicenter cohort of fine-needle aspiration biopsies. Results: In tissue biopsies, the best classifier, using only 10 genes, reached an optimal and consistent performance in the ninefold cross-validated testing set (sensitivity 93% and specificity 81%). In the multicenter cohort of fine-needle aspiration biopsy samples, the 10-gene signature, built into a multiplexed-qPCR IVD prototype, showed an area under the curve of 0.97, a positive predictive value of 78%, and a negative predictive value of 98%. By Bayes' theorem, the IVD prototype is expected to achieve a positive predictive value of 64–82% and a negative predictive value of 97–99% in patients with a cancer prevalence range of 20–40%. Conclusions: A new multiplexed-qPCR IVD prototype is reported that accurately classifies thyroid nodules and may provide a future solution suitable for local reference laboratory testing. PMID:28521616

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.

The likelihood of an indeterminate test result from a whole-blood interferon-gamma release assay for the diagnosis of Mycobacterium tuberculosis infection in children correlates with age and immune status.

PubMed

Haustein, Thomas; Ridout, Deborah A; Hartley, John C; Thaker, Urvashi; Shingadia, Delane; Klein, Nigel J; Novelli, Vas; Dixon, Garth L J

2009-08-01

Interferon-gamma release assays for the diagnosis of infection with Mycobacterium tuberculosis have been increasingly used in recent years and are endorsed by national guidelines, but experience regarding their use in children is still limited. We retrospectively evaluated the routine use of the QuantiFERON-TB Gold In-Tube assay (QFT-IT) in a pediatric tertiary care center with a high prevalence of immunocompromising conditions. The relationship between age, immune status, and likelihood of an indeterminate test result was analyzed using logistic regression analysis and fractional polynomials. Two hundred thirty-seven tests from 237 children were included in the analysis. Fifty-nine children (25%) were immunocompromised by our definition. An indeterminate test result was obtained in 83 children (35%). The likelihood of an indeterminate test result was inversely correlated with age (P < 0.001) for children who were not known to be immunocompromised, and decreased by 13% per year of age. Impaired immunity (P < 0.001) was independently associated with a higher probability of an indeterminate QFT-IT. Among 161 children with a documented tuberculin skin test, 89% had a concordant QFT-IT (kappa = 0.71). Twelve of 16 patients with culture-proven TB had a positive QFT-IT. These data suggest that QFT-IT may not provide a determinate test result in a substantial proportion of children in a tertiary care setting due to the combination of young age and primary and acquired immune deficiencies.

Indeterminate lung nodules in cancer patients: pretest probability of malignancy and the role of 18F-FDG PET/CT.

PubMed

Evangelista, Laura; Panunzio, Annalori; Polverosi, Roberta; Pomerri, Fabio; Rubello, Domenico

2014-03-01

The purpose of this study was to determine likelihood of malignancy for indeterminate lung nodules identified on CT comparing two standardized models with (18)F-FDG PET/CT. Fifty-nine cancer patients with indeterminate lung nodules (solid tumors; diameter, ≥5 mm) on CT had FDG PET/CT for lesion characterization. Mayo Clinic and Veterans Affairs Cooperative Study models of likelihood of malignancy were applied to solitary pulmonary nodules. High probability of malignancy was assigned a priori for multiple nodules. Low (<5%), intermediate (5-60%), and high (>60%) pretest malignancy probabilities were analyzed separately. Patients were reclassified with PET/CT. Histopathology or 2-year imaging follow-up established diagnosis. Outcome-based reclassification differences were defined as net reclassification improvement. A null hypothesis of asymptotic test was applied. Thirty-one patients had histology-proven malignancy. PET/CT was true-positive in 24 and true-negative in 25 cases. Negative predictive value was 78% and positive predictive value was 89%. On the basis of the Mayo Clinic model (n=31), 18 patients had low, 12 had intermediate, and one had high pretest likelihood; on the basis of the Veterans Affairs model (n=26), 5 patients had low, 20 had intermediate, and one had high pretest likelihood. Because of multiple lung nodules, 28 patients were classified as having high malignancy risk. PET/CT showed 32 negative and 27 positive scans. Net reclassification improvements respectively were 0.95 and 1.6 for Mayo Clinic and Veterans Affairs models (both p<0.0001). Fourteen of 31 (45.2%) and 12 of 26 (46.2%) patients with low and intermediate pretest likelihood, respectively, had positive findings on PET/CT for the Mayo Clinic and Veterans Affairs models, respectively. Of 15 patients with high pretest likelihood and negative findings on PET/CT, 13 (86.7%) did not have lung malignancy. PET/CT improves stratification of cancer patients with indeterminate pulmonary

Retrospective evaluation of ultrasound-indeterminate renal multilocular cystic masses by using neutrophil-lymphocyte ratio and computed tomography.

PubMed

Wang, Hanfeng; Gu, Liangyou; Jia, Rui; Zeng, Jing; Liu, Xiaoxia; Zhang, Dawei; Wu, Yongjie; Luo, Guangda; Zhang, Xu

2017-01-01

To evaluate the clinical usefulness of neutrophil-lymphocyte ratio (NLR) in differentiating the ultrasound-indeterminate renal multilocular cystic masses (RMCM) in comparison with computed tomography (CT) and whether NLR has additional benefits to CT on sensitivity of detecting the malignant. Overall, 93 patients who underwent normal ultrasound with a conclusion of indeterminate RMCM were examined by NLR and CT within 30 days before surgery or follow-up from March to September 2014 at PLA General Hospital and enrolled in this retrospective study. Logistic regression model was performed to find independent predictors for differentiating true nature of RMCM; differences in the validity parameters and diagnostic power of CT, NLR, and their combination were compared using McNemar tests and AUC model, respectively. The final diagnoses of the 93 patients consisted of 36 patients with benign complex cysts, 16 with multilocular cystic renal cell carcinoma, 9 with multilocular cystic nephroma, and 32 with clear cell renal cell carcinoma. Higher NLR were strongly associated with malignant masses. Multivariate logistic regression analysis revealed that NLR could be an independent predictor for differentiating true nature of these masses (OR = 3.617; 95% CI: 1.219-10.727; P = 0.020). For detecting the malignant masses, the sensitivity, specificity, and accuracy were 71.9%, 80.6%, and 75.3% for CT and 57.9%, 88.9%, and 69.9% for NLR under cutoff value of 2.31, respectively, whereas those of CT+NLR were 89.5%, 69.4%, and 81.7%. No significant difference was found between CT and NLR in sensitivity (P = 0.185), specificity (P = 0.549), and accuracy (P = 0.428). But the sensitivity of CT+NLR was significantly higher than those of CT (P = 0.002) and NLR (P<0.001), respectively; AUC model analysis indicated that CT+NLR got the largest area of 0.795 (P<0.001, 95% CI: 0.693-0.896) in comparison with those of CT (area = 0.795, P<0.001, 95% CI: 0.661-0.864) and NLR (area = 0.734, P<0

Loose Plant Architecture1, an INDETERMINATE DOMAIN protein involved in shoot gravitropism, regulates plant architecture in rice.

PubMed

Wu, Xinru; Tang, Ding; Li, Ming; Wang, Kejian; Cheng, Zhukuan

2013-01-01

Tiller angle and leaf angle are two important components of rice (Oryza sativa) plant architecture that play a crucial role in determining grain yield. Here, we report the cloning and characterization of the Loose Plant Architecture1 (LPA1) gene in rice, the functional ortholog of the AtIDD15/SHOOT GRAVITROPISM5 (SGR5) gene in Arabidopsis (Arabidopsis thaliana). LPA1 regulates tiller angle and leaf angle by controlling the adaxial growth of tiller node and lamina joint. LPA1 was also found to affect shoot gravitropism. Expression pattern analysis suggested that LPA1 influences plant architecture by affecting the gravitropism of leaf sheath pulvinus and lamina joint. However, LPA1 only influences gravity perception or signal transduction in coleoptile gravitropism by regulating the sedimentation rate of amyloplasts, distinct from the actions of LAZY1. LPA1 encodes a plant-specific INDETERMINATE DOMAIN protein and defines a novel subfamily of 28 INDETERMINATE DOMAIN proteins with several unique conserved features. LPA1 is localized in the nucleus and functions as an active transcriptional repressor, an activity mainly conferred by a conserved ethylene response factor-associated amphiphilic repression-like motif. Further analysis suggests that LPA1 participates in a complicated transcriptional and protein interaction network and has evolved novel functions distinct from SGR5. This study not only facilitates the understanding of gravitropism mechanisms but also generates a useful genetic material for rice breeding.

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.

GAUGING THE EXTENT OF THYROIDECTOMY FOR INDETERMINATE THYROID NODULES: AN ONCOLOGIC PERSPECTIVE.

PubMed

Schneider, David F; Cherney Stafford, Linda M; Brys, Nicole; Greenberg, Caprice C; Balentine, Courtney J; Elfenbein, Dawn M; Pitt, Susan C

2017-04-02

Increasing emphasis is being placed on appropriateness of care and avoidance of over- and under-treatment. Indeterminate thyroid nodules (ITNs) present a particular risk for this problem because cancer found via diagnostic lobectomy (DL) often requires a completion thyroidectomy (CT). However, initial total thyroidectomy (TT) for benign ITN results in lifelong thyroid hormone replacement. We sought to measure the accuracy and factors associated with the extent of initial thyroidectomy for ITN. We queried a single institution thyroid surgery database for all adult patients undergoing an initial operation for ITN. Multivariate logistic regression identified factors associated with either oncologic under- or overtreatment at initial operation. There were 639 patients with ITN. The median age was 52 (range, 18 to 93) years, 78.4% were female, and final pathology revealed a cancer >1 cm in 24.7%. The most common cytology was follicular neoplasm (45.1%) followed by Hürthle cell neoplasm (20.2%). CT or initial oncologic undertreatment was required in 58 patients (9.3%). Excluding those with goiters, 19.0% were treated with TT for benign final pathology. Multivariate analysis failed to identify any factor that independently predicted the need for CT. Female gender was associated with TT in benign disease (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.0 to 4.5; P = .05). Age >45 years predicted correct initial use of DL (OR, 2.6; 95% CI, 1.2 to 5.7; P = .02). Suspicious for papillary thyroid carcinoma (OR, 5.7; 95% CI, 2.1 to 15.3; P<.01) and frozen section (OR, 9.7; 95% CI, 2.5 to 38.6; P<.01) were associated with oncologically appropriate initial TT. The highest frequency of CT occurred in patients with follicular lesion of undetermined significance (11.6%). TT for benign final pathology occurred most frequently in patients with a Hürthle cell neoplasm (24.8%). In patients with ITN, nearly 30% received an inappropriate extent of initial thyroidectomy from an

Framing a Knowledge Base for a Legal Expert System Dealing with Indeterminate Concepts.

PubMed

Araszkiewicz, Michał; Łopatkiewicz, Agata; Zienkiewicz, Adam; Zurek, Tomasz

2015-01-01

Despite decades of development of formal tools for modelling legal knowledge and reasoning, the creation of a fully fledged legal decision support system remains challenging. Among those challenges, such system requires an enormous amount of commonsense knowledge to derive legal expertise. This paper describes the development of a negotiation decision support system (the Parenting Plan Support System or PPSS) to support parents in drafting an agreement (the parenting plan) for the exercise of parental custody of minor children after a divorce is granted. The main objective here is to discuss problems of framing an intuitively appealing and computationally efficient knowledge base that can adequately represent the indeterminate legal concept of the well-being of the child in the context of continental legal culture and of Polish law in particular. In addition to commonsense reasoning, interpretation of such a concept demands both legal expertise and significant professional knowledge from other domains.

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 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.

A portable anaerobic microbioreactor reveals optimum growth conditions for the methanogen Methanosaeta concilii.

PubMed

Steinhaus, Benjamin; Garcia, Marcelo L; Shen, Amy Q; Angenent, Largus T

2007-03-01

Conventional studies of the optimum growth conditions for methanogens (methane-producing, obligate anaerobic archaea) are typically conducted with serum bottles or bioreactors. The use of microfluidics to culture methanogens allows direct microscopic observations of the time-integrated response of growth. Here, we developed a microbioreactor (microBR) with approximately 1-microl microchannels to study some optimum growth conditions for the methanogen Methanosaeta concilii. The microBR is contained in an anaerobic chamber specifically designed to place it directly onto an inverted light microscope stage while maintaining a N2-CO2 environment. The methanogen was cultured for months inside microchannels of different widths. Channel width was manipulated to create various fluid velocities, allowing the direct study of the behavior and responses of M. concilii to various shear stresses and revealing an optimum shear level of approximately 20 to 35 microPa. Gradients in a single microchannel were then used to find an optimum pH level of 7.6 and an optimum total NH4-N concentration of less than 1,100 mg/liter (<47 mg/liter as free NH3-N) for M. concilii under conditions of the previously determined ideal shear stress and pH and at a temperature of 35 degrees C.

MRI in early prostate cancer detection: how to manage indeterminate or equivocal PI-RADS 3 lesions?

PubMed

Schoots, Ivo G

2018-02-01

This review focuses on indeterminate lesions on prostate magnetic resonance imaging (MRI), assigned as PI-RADS category 3. The prevalence of PI-RADS 3 index lesion in the diagnostic work-up is significant, varying between one in three (32%) to one in five (22%) men, depending on patient cohort of first biopsies, previously negative biopsies, and active surveillance biopsies. A management strategy must be developed for this group of men with an indeterminate suspicion of having clinically significant prostate cancer (csPCa). Currently available data show that the actual prevalence of csPCa after targeted biopsy in PI-RADS 3 lesions vary between patients groups from one in five (21%) to one in six (16%), depending on previous biopsy status. Although this prevalence is lower in comparison to PI-RADS 4 and PI-RADS 5 lesions, still a considerable proportion of men harbor significant disease. Men with such a PI-RADS 3 lesion should therefore be adequately managed. In general, the clinical approach of using a threshold of PI-RADS ≥4 instead of PI-RADS ≥3 to select MRI for targeted biopsies is not supported by data from our explorative literature search using current definitions of csPCa. A possible adaptation to the threshold of PI-RADS ≥4 in combination with other clinical markers could be considered within an active surveillance protocol, where the balance between the individual risk of missing csPCa and the constant process of repeating prostate biopsies is crucial. In the future, improvements in MR imaging and interpretation, combined with molecular biomarkers and multivariate risk models will all be employed in prostate cancer detection and monitoring. These combinations will aid decision-making in challenging circumstances, such as unclear and diagnostic equivocal results for csPCa at early detection.

Indeterminate orbital masses: restricted diffusion at MR imaging with echo-planar diffusion-weighted imaging predicts malignancy.

PubMed

Sepahdari, Ali R; Aakalu, Vinay K; Setabutr, Pete; Shiehmorteza, Masoud; Naheedy, John H; Mafee, Mahmood F

2010-08-01

To determine whether magnetic resonance (MR) imaging with diffusion-weighted (DW) imaging can help discriminate between radiologically indeterminate benign and malignant orbital masses and to identify optimal apparent diffusion coefficient (ADC) thresholds for such discrimination. Informed consent was waived for this HIPAA-compliant institutional review board-approved retrospective study. Forty-seven orbital masses imaged with echo-planar DW imaging were identified in 47 patients (25 female patients, 22 male patients; average age, 35 years). A fellowship-trained orbital surgeon determined reference-standard diagnoses on the basis of chart review, and a neuroradiology fellow and senior neuroradiologist who were blinded to the diagnoses selected a region of interest for each lesion by consensus. ADC was calculated from signal intensity on DW images obtained with b = 1000 and b = 0 sec/mm(2). Lesion ADC was also compared with that of normal-appearing white matter (ADC ratio). The Student t test was used to compare groups. Receiver operating characteristic analysis was performed. Intraobserver agreement was assessed with a repeat data collection. Malignant lesions had lower ADCs than benign lesions, irrespective of patient age (P < .02) and in adults specifically (P < .05). Lymphomas had lower ADCs than pseudotumors (P < .001). An ADC of less than 1.0 x 10(-3) mm(2)/sec and an ADC ratio of less than 1.2 were optimal for predicting malignancy (sensitivity, 63% for both; specificity, 84% and 90%, respectively; and accuracy, 77% and 81%, respectively). Lymphoma was differentiated from pseudotumor with 100% accuracy (in 16 of 16 cases) by using these values. Infiltrative lesions that were hypointense on T2-weighted images were better characterized with DW imaging than lesions that were hyperintense or well defined. Echo-planar DW MR imaging can help characterize indeterminate orbital masses.

Association of Malignancy Prevalence With Test Properties and Performance of the Gene Expression Classifier in Indeterminate Thyroid Nodules.

PubMed

Al-Qurayshi, Zaid; Deniwar, Ahmed; Thethi, Tina; Mallik, Tilak; Srivastav, Sudesh; Murad, Fadi; Bhatia, Parisha; Moroz, Krzysztof; Sholl, Andrew B; Kandil, Emad

2017-04-01

It is crucial for clinicians to know the malignancy prevalence within each indeterminate cytologic category to estimate the performance of the gene expression classifier (GEC). To examine the variability in the performance of the GEC. This retrospective cohort study of patients with Bethesda category III and IV thyroid nodules used single-institution data from January 1, 2013, through February 29, 2016. Expected negative predictive value (NPV) was calculated by adopting published sensitivity and specificity. Observed NPV was calculated based on the true-negative rate. Outcomes were compared with pooled data from 11 studies published January 1, 2010, to January 31, 2016. A total of 145 patients with 154 thyroid nodules were included in the study (mean [SD] age, 56.0 [16.2] years; 106 females [73.1%]). Malignancy prevalence was 45%. On the basis of this prevalence, the expected NPV is 85% and the observed NPV is 69%. If the prevalence is assumed to be 25%, the expected NPV would be 94%, whereas the observed NPV would be 85%. Pooled data analysis of 11 studies comprising 1303 participants revealed a malignancy prevalence of 31% (95% CI, 29%-34%) and a pooled NPV of 92% (95% CI, 87%-96%). In this study, variability in the performance of the GEC was not solely a function of malignancy prevalence and may have been attributable to intrinsic variability of the test sensitivity and specificity. The utility of the GEC in practice is elusive because of this variability. A better definition of the GEC's intrinsic properties is needed.

Framing a Knowledge Base for a Legal Expert System Dealing with Indeterminate Concepts

PubMed Central

Araszkiewicz, Michał; Łopatkiewicz, Agata; Zienkiewicz, Adam

2015-01-01

Despite decades of development of formal tools for modelling legal knowledge and reasoning, the creation of a fully fledged legal decision support system remains challenging. Among those challenges, such system requires an enormous amount of commonsense knowledge to derive legal expertise. This paper describes the development of a negotiation decision support system (the Parenting Plan Support System or PPSS) to support parents in drafting an agreement (the parenting plan) for the exercise of parental custody of minor children after a divorce is granted. The main objective here is to discuss problems of framing an intuitively appealing and computationally efficient knowledge base that can adequately represent the indeterminate legal concept of the well-being of the child in the context of continental legal culture and of Polish law in particular. In addition to commonsense reasoning, interpretation of such a concept demands both legal expertise and significant professional knowledge from other domains. PMID:26495435

Loose Plant Architecture1, an INDETERMINATE DOMAIN Protein Involved in Shoot Gravitropism, Regulates Plant Architecture in Rice1[W

PubMed Central

Wu, Xinru; Tang, Ding; Li, Ming; Wang, Kejian; Cheng, Zhukuan

2013-01-01

Tiller angle and leaf angle are two important components of rice (Oryza sativa) plant architecture that play a crucial role in determining grain yield. Here, we report the cloning and characterization of the Loose Plant Architecture1 (LPA1) gene in rice, the functional ortholog of the AtIDD15/SHOOT GRAVITROPISM5 (SGR5) gene in Arabidopsis (Arabidopsis thaliana). LPA1 regulates tiller angle and leaf angle by controlling the adaxial growth of tiller node and lamina joint. LPA1 was also found to affect shoot gravitropism. Expression pattern analysis suggested that LPA1 influences plant architecture by affecting the gravitropism of leaf sheath pulvinus and lamina joint. However, LPA1 only influences gravity perception or signal transduction in coleoptile gravitropism by regulating the sedimentation rate of amyloplasts, distinct from the actions of LAZY1. LPA1 encodes a plant-specific INDETERMINATE DOMAIN protein and defines a novel subfamily of 28 INDETERMINATE DOMAIN proteins with several unique conserved features. LPA1 is localized in the nucleus and functions as an active transcriptional repressor, an activity mainly conferred by a conserved ethylene response factor-associated amphiphilic repression-like motif. Further analysis suggests that LPA1 participates in a complicated transcriptional and protein interaction network and has evolved novel functions distinct from SGR5. This study not only facilitates the understanding of gravitropism mechanisms but also generates a useful genetic material for rice breeding. PMID:23124325

Optimum Suction Distribution for Transition Control

NASA Technical Reports Server (NTRS)

Balakumar, P.; Hall, P.

1996-01-01

The optimum suction distribution which gives the longest laminar region for a given total suction is computed. The goal here is to provide the designer with a method to find the best suction distribution subject to some overall constraint applied to the suction. We formulate the problem using the Lagrangian multiplier method with constraints. The resulting non-linear system of equations is solved using the Newton-Raphson technique. The computations are performed for a Blasius boundary layer on a flat-plate and crossflow cases. For the Blasius boundary layer, the optimum suction distribution peaks upstream of the maximum growth rate region and remains flat in the middle before it decreases to zero at the end of the transition point. For the stationary and travelling crossflow instability, the optimum suction peaks upstream of the maximum growth rate region and decreases gradually to zero.

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.

Molecular Signature of Indeterminate Thyroid Lesions: Current Methods to Improve Fine Needle Aspiration Cytology (FNAC) Diagnosis

PubMed Central

Cantara, Silvia; Marzocchi, Carlotta; Pilli, Tania; Cardinale, Sandro; Forleo, Raffaella; Castagna, Maria Grazia; Pacini, Furio

2017-01-01

Fine needle aspiration cytology (FNAC) represents the gold standard for determining the nature of thyroid nodules. It is a reliable method with good sensitivity and specificity. However, indeterminate lesions remain a diagnostic challenge and researchers have contributed molecular markers to search for in cytological material to refine FNAC diagnosis and avoid unnecessary surgeries. Nowadays, several “home-made” methods as well as commercial tests are available to investigate the molecular signature of an aspirate. Moreover, other markers (i.e., microRNA, and circulating tumor cells) have been proposed to discriminate benign from malignant thyroid lesions. Here, we review the literature and provide data from our laboratory on mutational analysis of FNAC material and circulating microRNA expression obtained in the last 6 years. PMID:28383480

Comparative analysis of diagnostic performance, feasibility and cost of different test-methods for thyroid nodules with indeterminate cytology

PubMed Central

Sciacchitano, Salvatore; Lavra, Luca; Ulivieri, Alessandra; Magi, Fiorenza; De Francesco, Gian Paolo; Bellotti, Carlo; Salehi, Leila B.; Trovato, Maria; Drago, Carlo; Bartolazzi, Armando

2017-01-01

Since it is impossible to recognize malignancy at fine needle aspiration (FNA) cytology in indeterminate thyroid nodules, surgery is recommended for all of them. However, cancer rate at final histology is <30%. Many different test-methods have been proposed to increase diagnostic accuracy in such lesions, including Galectin-3-ICC (GAL-3-ICC), BRAF mutation analysis (BRAF), Gene Expression Classifier (GEC) alone and GEC+BRAF, mutation/fusion (M/F) panel, alone, M/F panel+miRNA GEC, and M/F panel by next generation sequencing (NGS), FDG-PET/CT, MIBI-Scan and TSHR mRNA blood assay. We performed systematic reviews and meta-analyses to compare their features, feasibility, diagnostic performance and cost. GEC, GEC+BRAF, M/F panel+miRNA GEC and M/F panel by NGS were the best in ruling-out malignancy (sensitivity = 90%, 89%, 89% and 90% respectively). BRAF and M/F panel alone and by NGS were the best in ruling-in malignancy (specificity = 100%, 93% and 93%). The M/F by NGS showed the highest accuracy (92%) and BRAF the highest diagnostic odds ratio (DOR) (247). GAL-3-ICC performed well as rule-out (sensitivity = 83%) and rule-in test (specificity = 85%), with good accuracy (84%) and high DOR (27) and is one of the cheapest (113 USD) and easiest one to be performed in different clinical settings. In conclusion, the more accurate molecular-based test-methods are still expensive and restricted to few, highly specialized and centralized laboratories. GAL-3-ICC, although limited by some false negatives, represents the most suitable screening test-method to be applied on a large-scale basis in the diagnostic algorithm of indeterminate thyroid lesions. PMID:28472764

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.

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.

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.

Older adults who persistently present to the emergency department with severe, non-severe, and indeterminate episode patterns.

PubMed

Kaskie, Brian; Obrizan, Maksym; Jones, Michael P; Bentler, Suzanne; Weigel, Paula; Hockenberry, Jason; Wallace, Robert B; Ohsfeldt, Robert L; Rosenthal, Gary E; Wolinsky, Fredric D

2011-10-21

It is well known that older adults figure prominently in the use of emergency departments (ED) across the United States. Previous research has differentiated ED visits by levels of clinical severity and found health status and other individual characteristics distinguished severe from non-severe visits. In this research, we classified older adults into population groups that persistently present with severe, non-severe, or indeterminate patterns of ED episodes. We then contrasted the three groups using a comprehensive set of covariates. Using a unique dataset linking individual characteristics with Medicare claims for calendar years 1991-2007, we identified patterns of ED use among the large, nationally representative AHEAD sample consisting of 5,510 older adults. We then classified one group of older adults who persistently presented to the ED with clinically severe episodes and another group who persistently presented to the ED with non-severe episodes. These two groups were contrasted using logistic regression, and then contrasted against a third group with a persistent pattern of ED episodes with indeterminate levels of severity using multinomial logistic regression. Variable selection was based on Andersen's behavioral model of health services use and featured clinical status, demographic and socioeconomic characteristics, health behaviors, health service use patterns, local health care supply, and other contextual effects. We identified 948 individuals (17.2% of the entire sample) who presented a pattern in which their ED episodes were typically defined as severe and 1,076 individuals (19.5%) who typically presented with non-severe episodes. Individuals who persistently presented to the ED with severe episodes were more likely to be older (AOR 1.52), men (AOR 1.28), current smokers (AOR 1.60), experience diabetes (AOR (AOR 1.80), heart disease (AOR 1.70), hypertension (AOR 1.32) and have a greater amount of morbidity (AOR 1.48) than those who persistently

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...

Changes in the immune response after treatment with benznidazole versus no treatment in patients with chronic indeterminate Chagas disease.

PubMed

Vallejo, Alejandro; Monge-Maillo, Begoña; Gutiérrez, Carolina; Norman, Francesca F; López-Vélez, Rogelio; Pérez-Molina, José A

2016-12-01

Symptomatic chronic Chagas disease affects up to 40% of patients infected with Trypanosoma cruzi. The lack of reliable early markers of cure after therapy hinders disease management and clinical trials with new drugs. We performed a study with 18 months of follow-up to compare changes in immune parameters and T. cruzi-specific immune responses as surrogate markers of response to therapy between patients treated with benznidazole and untreated patients. This was a pilot, open-label, randomised clinical trial of treatment with benznidazole versus no treatment in patients with indeterminate chronic T. cruzi infection. In both groups we investigated changes in T-cell activation, T-cell subpopulations, regulatory T-cell counts, IL6, and sCD14 levels, and T. cruzi-specific immune responses (Th1, Th2, and Th17 responses). Fourteen patients were included in the study (seven in each group). Median age was 35 years (P 25-75 31-43), 57% were female, and 93% were Bolivian. Benznidazole was administered at 5mg/kg/day for 60days. Three patients discontinued benznidazole owing to adverse reactions and were not evaluated. At the end of the follow-up period, treated patients showed significantly less immune activation and lower regulatory T-cell counts, with an increased Th17 and Th1 response. This randomised pilot clinical trial administering benznidazole to patients with indeterminate chronic Chagas disease brings about changes in the adaptive immunity, leading to a general decrease in inflammatory status. This apparently beneficial response could act as the basis for monitoring new antiparasitic drugs. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

Matrix Metalloproteinases 2 and 9 Are Differentially Expressed in Patients with Indeterminate and Cardiac Clinical Forms of Chagas Disease

PubMed Central

Fares, Rafaelle Christine Gomes; Gomes, Juliana de Assis Silva; Garzoni, Luciana Ribeiro; Waghabi, Mariana Caldas; Saraiva, Roberto Magalhães; Medeiros, Nayara Ingrid; Oliveira-Prado, Roberta; Sangenis, Luiz Henrique Conde; Chambela, Mayara da Costa; de Araújo, Fernanda Fortes; Teixeira-Carvalho, Andréa; Damásio, Marcos Paulo; Valente, Vanessa Azevedo; Ferreira, Karine Silvestre; Sousa, Giovane Rodrigo; Rocha, Manoel Otávio da Costa

2013-01-01

Dilated chronic cardiomyopathy (DCC) from Chagas disease is associated with myocardial remodeling and interstitial fibrosis, resulting in extracellular matrix (ECM) changes. In this study, we characterized for the first time the serum matrix metalloproteinase 2 (MMP-2) and MMP-9 levels, as well as their main cell sources in peripheral blood mononuclear cells from patients presenting with the indeterminate (IND) or cardiac (CARD) clinical form of Chagas disease. Our results showed that serum levels of MMP-9 are associated with the severity of Chagas disease. The analysis of MMP production by T lymphocytes showed that CD8+ T cells are the main mononuclear leukocyte source of both MMP-2 and MMP-9 molecules. Using a new 3-dimensional model of fibrosis, we observed that sera from patients with Chagas disease induced an increase in the extracellular matrix components in cardiac spheroids. Furthermore, MMP-2 and MMP-9 showed different correlations with matrix proteins and inflammatory cytokines in patients with Chagas disease. Our results suggest that MMP-2 and MMP-9 show distinct activities in Chagas disease pathogenesis. While MMP-9 seems to be involved in the inflammation and cardiac remodeling of Chagas disease, MMP-2 does not correlate with inflammatory molecules. PMID:23856618

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.

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.

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.

Multi-institutional analysis of CT and MRI reports evaluating indeterminate renal masses: comparison to a national survey investigating desired report elements.

PubMed

Hu, Eric M; Zhang, Andrew; Silverman, Stuart G; Pedrosa, Ivan; Wang, Zhen J; Smith, Andrew D; Chandarana, Hersh; Doshi, Ankur; Shinagare, Atul B; Remer, Erick M; Kaffenberger, Samuel D; Miller, David C; Davenport, Matthew S

2018-04-17

To determine the need for a standardized renal mass reporting template by analyzing reports of indeterminate renal masses and comparing their contents to stated preferences of radiologists and urologists. The host IRB waived regulatory oversight for this multi-institutional HIPAA-compliant quality improvement effort. CT and MRI reports created to characterize an indeterminate renal mass were analyzed from 6 community (median: 17 reports/site) and 6 academic (median: 23 reports/site) United States practices. Report contents were compared to a published national survey of stated preferences by academic radiologists and urologists from 9 institutions. Descriptive statistics and Chi-square tests were calculated. Of 319 reports, 85% (271; 192 CT, 79 MRI) reported a possibly malignant mass (236 solid, 35 cystic). Some essential elements were commonly described: size (99% [269/271]), mass type (solid vs. cystic; 99% [268/271]), enhancement (presence vs. absence; 92% [248/271]). Other essential elements had incomplete penetrance: the presence or absence of fat in solid masses (14% [34/236]), size comparisons when available (79% [111/140]), Bosniak classification for cystic masses (54% [19/35]). Preferred but non-essential elements generally were described in less than half of reports. Nephrometry scores usually were not included for local therapy candidates (12% [30/257]). Academic practices were significantly more likely than community practices to include mass characterization details, probability of malignancy, and staging. Community practices were significantly more likely to include management recommendations. Renal mass reporting elements considered essential or preferred often are omitted in radiology reports. Variation exists across radiologists and practice settings. A standardized template may mitigate these inconsistencies.

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

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.

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.

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.

Concordance between the tuberculin skin test and interferon gamma release assay (IGRA) for diagnosing latent tuberculosis infection in patients with systemic lupus erythematosus and patient characteristics associated with an indeterminate IGRA.

PubMed

Cho, H; Kim, Y W; Suh, C-H; Jung, J-Y; Um, Y-J; Jung, J-H; Kim, H-A

2016-10-01

We investigated the agreement between the tuberculin skin test (TST) and the QuantiFERON-TB gold (QFT-G) assay in the diagnosis of latent tuberculosis infection (LTBI) in patients with systemic lupus erythematosus (SLE). Furthermore, we evaluated the factors associated with indeterminate results in the QFT-G assay in patients with SLE. We enrolled 136 patients with SLE prospectively, and compared them to 66 patients with rheumatoid arthritis (RA). In addition to the TST, QFT-G assay, patients' medications, and Bacillus Calmette-Guérin (BCG) vaccination status were also investigated. A positive TST or QFT-G assay result without an active tuberculosis lesion on chest x-ray was considered to indicate a diagnosis of LTBI. The prevalence of LTBI was 26.5% in patients with SLE and 30.3% in patients with RA. The agreement between the TST and QFT-G assay was fair in SLE patients, but poor in RA patients. BCG vaccination was one factor associated with discordance between TST and QFT-G. Older age and higher SLE Disease Activity Index (SLEDAI) score were associated with a negative TST/positive QFT-G result in patients with SLE. Higher SLEDAI score and increased glucocorticoid dose were associated with an indeterminate result in the QFT-G assay for patients with SLE. Agreement between the QFT-G assay and TST in patients with SLE was found to be fair. However, BCG vaccination status, age, and SLEDAI score are all factors that could result in discordance between the two tests. Indeterminate results from the QFT-G assay may be caused by a higher SLEDAI score or increased glucocorticoid dose. © The Author(s) 2016.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

Preliminary estimation of the realistic optimum temperature for vegetation growth in China.

PubMed

Cui, Yaoping

2013-07-01

The estimation of optimum temperature of vegetation growth is very useful for a wide range of applications such as agriculture and climate change studies. Thermal conditions substantially affect vegetation growth. In this study, the normalized difference vegetation index (NDVI) and daily temperature data set from 1982 to 2006 for China were used to examine optimum temperature of vegetation growth. Based on a simple analysis of ecological amplitude and Shelford's law of tolerance, a scientific framework for calculating the optimum temperature was constructed. The optimum temperature range and referenced optimum temperature (ROT) of terrestrial vegetation were obtained and explored over different eco-geographical regions of China. The results showed that the relationship between NDVI and air temperature was significant over almost all of China, indicating that terrestrial vegetation growth was closely related to thermal conditions. ROTs were different in various regions. The lowest ROT, about 7.0 °C, occurred in the Qinghai-Tibet Plateau, while the highest ROT, more than 22.0 °C, occurred in the middle and lower reaches of the Yangtze River and the Southern China region.

Preliminary Estimation of the Realistic Optimum Temperature for Vegetation Growth in China

NASA Astrophysics Data System (ADS)

Cui, Yaoping

2013-07-01

The estimation of optimum temperature of vegetation growth is very useful for a wide range of applications such as agriculture and climate change studies. Thermal conditions substantially affect vegetation growth. In this study, the normalized difference vegetation index (NDVI) and daily temperature data set from 1982 to 2006 for China were used to examine optimum temperature of vegetation growth. Based on a simple analysis of ecological amplitude and Shelford's law of tolerance, a scientific framework for calculating the optimum temperature was constructed. The optimum temperature range and referenced optimum temperature (ROT) of terrestrial vegetation were obtained and explored over different eco-geographical regions of China. The results showed that the relationship between NDVI and air temperature was significant over almost all of China, indicating that terrestrial vegetation growth was closely related to thermal conditions. ROTs were different in various regions. The lowest ROT, about 7.0 °C, occurred in the Qinghai-Tibet Plateau, while the highest ROT, more than 22.0 °C, occurred in the middle and lower reaches of the Yangtze River and the Southern China region.

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.

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.

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

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.

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 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...

Optimum quantum receiver for detecting weak signals in PAM communication systems

NASA Astrophysics Data System (ADS)

Sharma, Navneet; Rawat, Tarun Kumar; Parthasarathy, Harish; Gautam, Kumar

2017-09-01

This paper deals with the modeling of an optimum quantum receiver for pulse amplitude modulator (PAM) communication systems. The information bearing sequence {I_k}_{k=0}^{N-1} is estimated using the maximum likelihood (ML) method. The ML method is based on quantum mechanical measurements of an observable X in the Hilbert space of the quantum system at discrete times, when the Hamiltonian of the system is perturbed by an operator obtained by modulating a potential V with a PAM signal derived from the information bearing sequence {I_k}_{k=0}^{N-1}. The measurement process at each time instant causes collapse of the system state to an observable eigenstate. All probabilities of getting different outcomes from an observable are calculated using the perturbed evolution operator combined with the collapse postulate. For given probability densities, calculation of the mean square error evaluates the performance of the receiver. Finally, we present an example involving estimating an information bearing sequence that modulates a quantum electromagnetic field incident on a quantum harmonic oscillator.

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…

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

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.

Endometrial vs. cervical cancer: development and pilot testing of a magnetic resonance imaging (MRI) scoring system for predicting tumor origin of uterine carcinomas of indeterminate histology.

PubMed

Bourgioti, Charis; Chatoupis, Konstantinos; Panourgias, Evangelia; Tzavara, Chara; Sarris, Kyrillos; Rodolakis, Alexandros; Moulopoulos, Lia Angela

2015-10-01

To report discriminant MRI features between cervical and endometrial carcinomas and to design an MRI- scoring system, with the potential to predict the origin of uterine cancer (cervix or endometrium) in histologically indeterminate cases. Dedicated pelvic MRIs of 77 patients with uterine tumors involving both cervix and corpus were retrospectively analyzed by two experts in female imaging. Seven MRI tumor characteristics were statistically tested for their discriminant ability for tumor origin compared to final histology: tumor location, perfusion pattern, rim enhancement, depth of myometrial invasion, cervical stromal integrity, intracavitary mass, and retained endometrial secretions. Kappa values were estimated to assess the levels of inter-rater reliability. On the basis of positive likelihood ratio values, an MRI-score was assigned. K value was excellent for most of the imaging criteria. Using ROC curve analysis, the estimated optimal cut-off for the MRI-scoring system was 4 with 96.6% sensitivity and 100% specificity. Using a ≥4 cut-off for cervical cancers and <4 for endometrial cancers, 97.4% of the patients were correctly classified. 2/58 patients with cervical cancer had MRI score <4 and none of the patients with endometrial cancer had MRI score >4. The area under curve of the MRI-scoring system was 0.99 (95% CI 0.98-1.00). When the MRI-score was applied to 20/77 patients with indeterminate initial biopsy and to 5/26 surgically treated patients with erroneous pre-op histology, all cases were correctly classified. The produced MRI-scoring system may be a reliable problem-solving tool for the differential diagnosis of cervical vs. endometrial cancer in cases of equivocal histology.

Determination of Optimum Cross-section for Oran Highway Revetment

NASA Astrophysics Data System (ADS)

Sogut, E.; Velioglu, D.; Guler, I.

2016-12-01

Revetments are shore parallel, sloping coastal structures which are built to provide protection from the negative effects of the sea. The revetment mentioned in this study is located in the City of Oran, Algeria and is currently under construction. This study investigates the determination of the optimum revetment cross section for Oran highway, considering both the hydraulic stability of the revetment and economy. The existence of cliffs in the region and the settlement of the City of Oran created a necessity to re-align Oran highway; therefore, it was shifted towards the Gulf of Oran. Approximately 1 km of the highway is to be constructed on the Mediterranean Sea due to the new alignment. In order to protect the sea side of the road from the adverse effects of the sea, a revetment was designed. The proposed cross section had an armour layer composed of 23 tons of antifer units and regular placement of armour units was recommended. In order to check the hydraulic stability of the proposed section, physical model tests were performed in the laboratory of LEM (Laboratoire d'Etudes Maritimes) in Algeria, using the pre-determined design wave conditions. The physical model tests revealed that the trunk of the revetment was totaly damaged. Accordingly, the proposed section was found insufficient and certain modifications were required. The first modification was made in the arrangement of armour units, changing them from regular to irregular. After testing the new cross section, it was observed that the revetment was vulnerable to breaking wave attack due to the toe geometry and thus the toe of the revetment had to be re-shaped. Therefore, the second option was to reduce the toe elevation. It was observed that even though the revetment trunk was safe, the damage in the toe was not in acceptable limits. The new cross section was found insufficient and as the final option, the weight of the antifer units used in the armour layer was increased, the toe length of the

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.

Evaluation of Optimum Moisture Content for Composting of Beef Manure and Bedding Material Mixtures Using Oxygen Uptake Measurement

PubMed Central

Kim, Eunjong; Lee, Dong-Hyun; Won, Seunggun; Ahn, Heekwon

2016-01-01

Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg O2/g VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS’s optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust’s coarse particle size and bulking effect. PMID:26954138

Evaluation of Optimum Moisture Content for Composting of Beef Manure and Bedding Material Mixtures Using Oxygen Uptake Measurement.

PubMed

Kim, Eunjong; Lee, Dong-Hyun; Won, Seunggun; Ahn, Heekwon

2016-05-01

Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg O2/g VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS's optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust's coarse particle size and bulking effect.

The contribution of qualitative CEUS to the determination of malignancy in adnexal masses, indeterminate on conventional US - a multicenter study.

PubMed

Zhang, Xinling; Mao, Yongjiang; Zheng, Rongqin; Zheng, Zhijuan; Huang, Zeping; Huang, Dongmei; Zhang, Jing; Dai, Qing; Zhou, Xiaodong; Wen, Yanling

2014-01-01

The aim of this study is to evaluate the efficacy of qualitative analysis of contrast-enhanced ultrasound (CEUS) in discrimination of adnexal masses which were undetermined by conventional ultrasound (US). A total of 120 patients underwent transabdominal CEUS. The initial enhancement time and intensity compared with the uterine myometrium, contrast agent distribution patterns and dynamic changes of enhancement were assessed. The sensitivity (Sen), specificity (Spe), positive predictive value (PPV), negative predictive value (NPV), accuracy (ACC) and Youden's index were calculated for contrast variables. The gold standard was the histological diagnosis. There were 48 malignant tumors and 72 benign tumors. The enhancement features of malignant masses were different from benign ones. Earlier or simultaneous enhancement with inhomogeneous enhancement yielded the highest capability in differential diagnosis, and Sen, Spe, PPV, NPV, ACC, Youden's index was 89.6%, 97.2%, 93.2%, 95.6%, 93.3%, and 0.88, respectively. The qualitative evaluation of CEUS is useful in the differential diagnosis of adnexal masses where conventional US is indeterminate.

Development of a Method for Selecting Optimum Sites for the Automatic Mountain Meteorology Observation Station (AMOS) to Improve Predictability of Forest Fires in Inaccessible Area

NASA Astrophysics Data System (ADS)

Yoon, S.; Won, M.; Jang, K.; Lim, J.

2016-12-01

As there has been a recent increase in the case of forest fires in North Korea descending southward through the De-Militarized Zone (DMZ), ensuring proper response to such events has been a challenge. Therefore, in order to respond and manage these forest fires appropriately, an improvement in the forest fire predictability through integration of mountain weather information observed at the most optimal site is necessary. This study is a proactive case in which a spatial analysis and an on-site assessment method were developed for selecting an optimum site for a mountain weather observation in national forest. For spatial analysis, the class 1 and 2 forest fire danger areas for the past 10 years, accessibility maximum 100m, Automatic Weather Station (AWS) redundancy within 2.5km, and mountain terrains higher than 200m were analyzed. A final overlay analysis was performed to select the candidates for the field assessment. The sites selected through spatial analysis were quantitatively evaluated based on the optimal meteorological environment, forest and hiking trail accessibility, AWS redundancy, and supply of wireless communication and solar powered electricity. The sites with total score of 70 and higher were accepted as adequate. At the final selected sites, an AMOS was established, and integration of mountain and Korea Meteorological Administration (KMA) weather data improved the forest fire predictability in South Korea by 10%. Given these study results, we expect that establishing an automatic mountain meteorology observation station at the optimal sites in inaccessible area and integrating mountain weather data will improve the predictability of forest fires.

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.

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

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...

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.

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 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

Individual heterogeneity and offspring sex affect the growth-reproduction trade-off in a mammal with indeterminate growth.

PubMed

Gélin, Uriel; Wilson, Michelle E; Cripps, Jemma; Coulson, Graeme; Festa-Bianchet, Marco

2016-04-01

Reproduction can lead to a trade-off with growth, particularly when individuals reproduce before completing body growth. Kangaroos have indeterminate growth and may always face this trade-off. We combined an experimental manipulation of reproductive effort and multi-year monitoring of a large sample size of marked individuals in two populations of eastern grey kangaroos to test the predictions (1) that reproduction decreases skeletal growth and mass gain and (2) that mass loss leads to reproductive failure. We also tested if sex-allocation strategies influenced these trade-offs. Experimental reproductive suppression revealed negative effects of reproduction on mass gain and leg growth from 1 year to the next. Unmanipulated females, however, showed a positive correlation between number of days lactating and leg growth over periods of 2 years and longer, suggesting that over the long term, reproductive costs were masked by individual heterogeneity in resource acquisition. Mass gain was necessary for reproductive success the subsequent year. Although mothers of daughters generally lost more mass than females nursing sons, mothers in poor condition experienced greater mass gain and arm growth if they had daughters than if they had sons. The strong links between individual mass changes and reproduction suggest that reproductive tactics are strongly resource-dependent.

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...

Influence of the viscoelastic properties of the respiratory system on the energetically optimum breathing frequency.

PubMed

Bates, J H; Milic-Emili, J

1993-01-01

We hypothesized that the viscoelastic properties of the respiratory system should have significant implications for the energetically optimal frequency of breathing, in view of the fact that these properties cause marked dependencies of overall system resistance and elastance on frequency. To test our hypothesis we simulated two models of canine and human respiratory system mechanics during sinusoidal breathing and calculated the inspiratory work (WI) and pressure-time integral (PTI) per minute under both resting and exercise conditions. The two models were a two-compartment viscoelastic model and a single-compartment model. Requiring minute alveolar ventilation to be fixed, we found that both models predicted almost identical optimum breathing frequencies. The calculated PTI was very insensitive to increases in breathing frequency above the optimal frequencies, while WI was found to increase slowly with frequency above its optimum. In contrast, both WI and PTI increased sharply as frequency decreased below their respective optima. A sensitivity analysis showed that the model predictions were very insensitive to the elastance and resistance values chosen to characterize tissue viscoelasticity. We conclude that the WI criterion for choosing the frequency of breathing is compatible with observations in nature, whereas the optimal frequency predictions of the PTI are rather too high. Both criteria allow for a fairly wide margin of choice in frequency above the optimum values without incurring excessive additional energy expenditure. Furthermore, contrary to our expectations, the viscoelastic properties of the respiratory system tissues do not pose a noticeable problem to the respiratory controller in terms of energy expenditure.

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

Experimental optimum design and luminescence properties of NaY(Gd)(MoO4)2:Er3+ phosphors

NASA Astrophysics Data System (ADS)

Jia-Shi, Sun; Sai, Xu; Shu-Wei, Li; Lin-Lin, Shi; Zi-Hui, Zhai; Bao-Jiu, Chen

2016-06-01

Three-factor orthogonal design (OD) of Er3+/Gd3+/T (calcination temperature) is used to optimize the luminescent intensity of NaY(Gd)(MoO4)2:Er3+ phosphor. Firstly, the uniform design (UD) is introduced to explore the doping concentration range of Er3+/Gd3+. Then OD and range analysis are performed based on the results of UD to obtain the primary and secondary sequence and the best combination of Er3+, Gd3+, and T within the experimental range. The optimum sample is prepared by the high temperature solid state method. Photoluminescence excitation and emission spectra of the optimum sample are detected. The intense green emissions (530 nm and 550 nm) are observed which originate from Er3+ 2H11/2→ 4I15/2 and 4S3/2→4I15/2, respectively. Thermal effect is investigated in the optimum NaY(Gd3+)(MoO4)2:Er3+ phosphors, and the green emission intensity decreases as temperature increases. Project supported by Education Reform Fund of Dalian Maritime University, China (Grant No. 2015Y37), the Natural Science Foundation of Liaoning Province, China (Grant Nos. 2015020190 and 2014025010), the Open Fund of the State Key Laboratory on Integrated Optoelectronics, China (Grant No. IOSKL2015KF27), and the Fundamental Research Funds for the Central Universities, China (Grant No. 3132016121).

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.

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.

Overexpression of KNAT1 in lettuce shifts leaf determinate growth to a shoot-like indeterminate growth associated with an accumulation of isopentenyl-type cytokinins.

PubMed

Frugis, G; Giannino, D; Mele, G; Nicolodi, C; Chiappetta, A; Bitonti, M B; Innocenti, A M; Dewitte, W; Van Onckelen, H; Mariotti, D

2001-08-01

Leaves are specialized organs characterized by defined developmental destiny and determinate growth. The overexpression of Knotted1-like homeobox genes in different species has been shown to alter leaf shape and development, but a definite role for this class of genes remains to be established. Transgenics that overexpress Knotted1-like genes present some traits that are characteristic of altered cytokinin physiology. Here we show that lettuce (Lactuca sativa) leaves that overexpress KNAT1, an Arabidopsis kn1-like gene, acquire characteristics of indeterminate growth typical of the shoot and that this cell fate change is associated with the accumulation of specific types of cytokinins. The possibility that the phenotypic effects of KNAT1 overexpression may arise primarily from the modulation of local ratios of different cytokinins is 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.

Determination of Optimum Cross-section for Oran Highway Revetment

NASA Astrophysics Data System (ADS)

Velioglu, Deniz; Sogut, Erdinc; Guler, Isikhan

2017-04-01

Revetments are shore parallel, sloping coastal structures which are built to provide protection from the negative effects of the sea. The revetment mentioned in this study is located in the City of Oran, Algeria and is currently under construction. This study investigates the determination of the optimum revetment cross section for Oran highway, considering both the hydraulic stability of the revetment and economy. The existence of cliffs in the region and the settlement of the City of Oran created a necessity to re-align Oran highway; therefore, it was shifted towards the Gulf of Oran. Approximately 1 km of the highway is to be constructed on the Mediterranean Sea due to the new alignment. In order to protect the sea side of the road from the adverse effects of the sea, a revetment was designed. The proposed cross section had an armour layer composed of 23 tons of antifer units and regular placement of armour units was recommended. In order to check the hydraulic stability of the proposed section, physical model tests were performed in the laboratory of LEM (Laboratoire d'Etudes Maritimes) in Algeria, using the pre-determined design wave conditions. The physical model tests revealed that the trunk of the revetment was totaly damaged. Accordingly, the proposed section was found insufficient and certain modifications were required. The first modification was made in the arrangement of armour units, changing them from regular to irregular. After testing the new cross section, it was observed that the revetment was vulnerable to breaking wave attack due to the toe geometry and thus the toe of the revetment had to be re-shaped. Therefore, the second option was to reduce the toe elevation. It was observed that even though the revetment trunk was safe, the damage in the toe was not in acceptable limits. The new cross section was found insufficient and as the final option, the weight of the antifer units used in the armour layer was increased, the toe length of the

Developement of an Optimum Interpolation Analysis Method for the CYBER 205

NASA Technical Reports Server (NTRS)

Nestler, M. S.; Woollen, J.; Brin, Y.

1985-01-01

A state-of-the-art technique to assimilate the diverse observational database obtained during FGGE, and thus create initial conditions for numerical forecasts is described. The GLA optimum interpolation (OI) analysis method analyzes pressure, winds, and temperature at sea level, mixing ratio at six mandatory pressure levels up to 300 mb, and heights and winds at twelve levels up to 50 mb. Conversion to the CYBER 205 required a major re-write of the Amdahl OI code to take advantage of the CYBER vector processing capabilities. Structured programming methods were used to write the programs and this has resulted in a modular, understandable code. Among the contributors to the increased speed of the CYBER code are a vectorized covariance-calculation routine, an extremely fast matrix equation solver, and an innovative data search and sort technique.

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.

Dielectric properties, optimum formulation and microwave baking conditions of chickpea cakes.

PubMed

Alifakı, Yaşar Özlem; Şakıyan, Özge

2017-03-01

The aim of this study was to correlate dielectric properties with quality parameters, and to optimize cake formulation and baking conditions by response surface methodology. Weight loss, color, specific volume, hardness and porosity were evaluated. The samples with different DATEM (0.4, 0.8 and 1.2%) and chickpea flour concentrations (30, 40 and 50%) were baked in microwave oven at different power (300, 350, 400 W) and baking times (2.50, 3.0, 3.50 min). It was found that microwave power showed significant effect on color, while baking time showed effect on weight loss, porosity, hardness, specific volume and dielectric properties. Emulsifier level affected porosity, specific volume and dielectric constant. Chickpea flour level affected porosity, color, hardness and dielectric properties of cakes. The optimum microwave power, baking time, DATEM level and chickpea flour level were found as 400 W, 2.84 min, 1.2% and 30%, respectively. The comparison between conventionally baked and the microwave baked cakes at optimum points showed that color difference, weight loss, specific volume and porosity values of microwave baked cakes were less than those of conventionally baked cakes, on the other hand, hardness values were higher. Moreover, a negative correlation between dielectric constant and porosity, and weight loss values were detected for microwave baked samples. A negative correlation between dielectric loss factor and porosity was observed. These correlations indicated that quality characteristics of a microwave baked cake sample can be assessed from dielectric properties. These correlations provides understanding on the behavior of food material during microwave processing.

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.

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...

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.

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

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.

Overexpression of KNAT1 in Lettuce Shifts Leaf Determinate Growth to a Shoot-Like Indeterminate Growth Associated with an Accumulation of Isopentenyl-Type Cytokinins1

PubMed Central

Frugis, Giovanna; Giannino, Donato; Mele, Giovanni; Nicolodi, Chiara; Chiappetta, Adriana; Bitonti, Maria Beatrice; Innocenti, Anna Maria; Dewitte, Walter; Van Onckelen, Harry; Mariotti, Domenico

2001-01-01

Leaves are specialized organs characterized by defined developmental destiny and determinate growth. The overexpression of Knotted1-like homeobox genes in different species has been shown to alter leaf shape and development, but a definite role for this class of genes remains to be established. Transgenics that overexpress Knotted1-like genes present some traits that are characteristic of altered cytokinin physiology. Here we show that lettuce (Lactuca sativa) leaves that overexpress KNAT1, an Arabidopsis kn1-like gene, acquire characteristics of indeterminate growth typical of the shoot and that this cell fate change is associated with the accumulation of specific types of cytokinins. The possibility that the phenotypic effects of KNAT1 overexpression may arise primarily from the modulation of local ratios of different cytokinins is discussed. PMID:11500537

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.

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

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

Stretch-induced, steady-state force enhancement in single skeletal muscle fibers exceeds the isometric force at optimum fiber length.

PubMed

Rassier, Dilson E; Herzog, Walter; Wakeling, Jennifer; Syme, Douglas A

2003-09-01

Stretch-induced force enhancement has been observed in a variety of muscle preparations and on structural levels ranging from single fibers to in vivo human muscles. It is a well-accepted property of skeletal muscle. However, the mechanism causing force enhancement has not been elucidated, although the sarcomere-length non-uniformity theory has received wide support. The purpose of this paper was to re-investigate stretch-induced force enhancement in frog single fibers by testing specific hypotheses arising from the sarcomere-length non-uniformity theory. Single fibers dissected from frog tibialis anterior (TA) and lumbricals (n=12 and 22, respectively) were mounted in an experimental chamber with physiological Ringer's solution (pH=7.5) between a force transducer and a servomotor length controller. The tetantic force-length relationship was determined. Isometric reference forces were determined at optimum length (corresponding to the maximal, active, isometric force), and at the initial and final lengths of the stretch experiments. Stretch experiments were performed on the descending limb of the force-length relationship after maximal tetanic force was reached. Stretches of 2.5-10% (TA) and 5-15% lumbricals of fiber length were performed at 0.1-1.5 fiber lengths/s. The stretch-induced, steady-state, active isometric force was always equal or greater than the purely isometric force at the muscle length from which the stretch was initiated. Moreover, for stretches of 5% fiber length or greater, and initiated near the optimum length of the fiber, the stretch-enhanced active force always exceeded the maximal active isometric force at optimum length. Finally, we observed a stretch-induced enhancement of passive force. We conclude from these results that the sarcomere length non-uniformity theory alone cannot explain the observed force enhancement, and that part of the force enhancement is associated with a passive force that is substantially greater after active

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

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

Determine the optimum spectral reflectance of juniper and pistachio in arid and semi-arid region

NASA Astrophysics Data System (ADS)

Fadaei, Hadi; Suzuki, Rikie

2012-11-01

Arid and semi-arid areas of northeast Iran cover about 3.4 million ha are populated by two main tree species, the broadleaf Pistacia vera. L (pistachio) and the conifer Juniperus excelsa ssp. polycarpos (Persian juniper). Natural stands of pistachio in Iran are not only environmentally important but genetically essential as seed sources for pistachio production in orchards. In this study, we estimated the optimum spectral reflectance of juniper forests and natural pistachio stands using remote sensing to help in the sustainable management and production of pistachio in Iran. In this research spectral reflectance are able to specify of multispectral from Advanced Land Observing Satellite (ALOS) that provided by JAXA. These data included PRISM is a panchromatic radiometer with a 2.5 m spatial resolution at nadir, has one band with a wavelength of 0.52-0.77 μm and AVNIR-2 is a visible and near infrared radiometer for observing land and coastal zones with a 10 m spatial resolution at nadir, has four multispectral bands: blue (0.42-0.50 μm), green (0.52-0.60 μm), red (0.61-0.69 μm), and near infrared (0.76-0.89 μm). Total ratio vegetation index (TRVI) of optimum spectral reflectance of juniper and pistachio have been evaluated. The result of TRVI for Pistachio and juniper were (R2= 0.71 and 0.55). I hope this research can provide decision of managers to helping sustainable management for arid and semi-arid regions in Iran.

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.

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.

The Contribution of Qualitative CEUS to the Determination of Malignancy in Adnexal Masses, Indeterminate on Conventional US – A Multicenter Study

PubMed Central

Zhang, Xinling; Mao, Yongjiang; Zheng, Rongqin; Zheng, Zhijuan; Huang, Zeping; Huang, Dongmei; Zhang, Jing; Dai, Qing; Zhou, Xiaodong; Wen, Yanling

2014-01-01

The aim of this study is to evaluate the efficacy of qualitative analysis of contrast-enhanced ultrasound (CEUS) in discrimination of adnexal masses which were undetermined by conventional ultrasound (US). A total of 120 patients underwent transabdominal CEUS. The initial enhancement time and intensity compared with the uterine myometrium, contrast agent distribution patterns and dynamic changes of enhancement were assessed. The sensitivity (Sen), specificity (Spe), positive predictive value (PPV), negative predictive value (NPV), accuracy (ACC) and Youden’s index were calculated for contrast variables. The gold standard was the histological diagnosis. There were 48 malignant tumors and 72 benign tumors. The enhancement features of malignant masses were different from benign ones. Earlier or simultaneous enhancement with inhomogeneous enhancement yielded the highest capability in differential diagnosis, and Sen, Spe, PPV, NPV, ACC, Youden’s index was 89.6%, 97.2%, 93.2%, 95.6%, 93.3%, and 0.88, respectively. The qualitative evaluation of CEUS is useful in the differential diagnosis of adnexal masses where conventional US is indeterminate. PMID:24736589

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.

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.

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.

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.

Rational molecular dynamics scheme for predicting optimum concentration loading of nano-additive in phase change materials

NASA Astrophysics Data System (ADS)

Rastogi, Monisha; Vaish, Rahul; Madhar, Niyaz Ahamad; Shaikh, Hamid; Al-Zahrani, S. M.

2015-10-01

The present study deals with the diffusion and phase transition behaviour of paraffin reinforced with carbon nano-additives namely graphene oxide (GO) and surface functionalized single walled carbon nanotubes (SWCNT). Bulk disordered systems of paraffin hydrocarbons impregnated with carbon nano-additives have been generated in realistic equilibrium conformations for potential application as latent heat storage systems. Ab initio molecular dynamics(MD) in conjugation with COMPASS forcefield has been implemented using periodic boundary conditions. The proposed scheme allows determination of optimum nano-additive loading for improving thermo-physical properties through analysis of mass, thermal and transport properties; and assists in determination of composite behaviour and related performance from microscopic point of view. It was observed that nanocomposites containing 7.8 % surface functionalised SWCNT and 55% GO loading corresponds to best latent heat storage system. The propounded methodology could serve as a by-pass route for economically taxing and iterative experimental procedures required to attain the optimum composition for best performance. The results also hint at the large unexplored potential of ab-initio classical MD techniques for predicting performance of new nanocomposites for potential phase change material applications.

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…

An evaluation of Seasat-A data in relation to optimum track ship weather routing and site specific forecasting for the offshore oil industry

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

Daley, C.; Johnson, R.G.; Thomson, J.C.

1981-07-01

The usefulness of Seasat-A SASS and altimeter measurements is reviewed. Five oceanic areas were selected: the Gulf of Alaska, central and western north Atlantic, eastern north Pacific, southern Indian Ocean, and the North Sea. Both Seasat-aided and conventional analyses were used in offshore hindcast and optimum ship routing situations. Where conventional observations are relatively dense, Seasat wind and wave data have greater impact in determining the shape of major map features than in positioning the features. In data sparse areas, Seasat data permit greater definition of surface features as well as their precise location. The use of Seasat data inmore » optimum ship routing is quantified by means of comparative studies in the Gulf of Alaska.« less

Kinetic characterization, optimum conditions for catalysis and substrate preference of secretory phospholipase A2 from Glycine max in model membrane systems.

PubMed

Mariani, María Elisa; Madoery, Ricardo Román; Fidelio, Gerardo Daniel

2015-01-01

Two secretory phospholipase A2 (sPLA2s) from Glycine max, GmsPLA2-IXA-1 and GmsPLA2-XIB-2, have been purified as recombinant proteins and the activity was evaluated in order to obtain the optimum conditions for catalysis using mixed micelles and lipid monolayers as substrate. Both sPLA2s showed a maximum enzyme activity at pH 7 and a requirement of Ca(2+) in the micromolar range. These parameters were similar to those found for animal sPLA2s but a surprising optimum temperature for catalysis at 60 °C was observed. The effect of negative interfacial charges on the hydrolysis of organized substrates was evaluated through initial rate measurements using short chain phospholipids with different head groups. The enzymes showed subtle differences in the specificity for phospholipids with different head groups (DLPC, DLPG, DLPE, DLPA) in presence or absence of NaCl. Both recombinant enzymes showed lower activity toward anionic phospholipids and a preference for the zwitterionic ones. The values of the apparent kinetic parameters (Vmax and KM) demonstrated that these enzymes have more affinity for phosphatidylcholine compared with phosphatidylglycerol, in contrast with the results observed for pancreatic sPLA2. A hopping mode of catalysis was proposed for the action of these sPLA2 on mixed phospholipid/triton micelles. On the other hand, Langmuir-monolayers assays indicated an optimum lateral surface pressure for activity in between 13 and 16 mN/m for both recombinant enzymes. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

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.

Diabetes, obesity and non-optimum blood pressure levels in a group of employees of the University of Puerto Rico, Medical Sciences Campus, 2003.

PubMed

Disdier-Flores, Orville M; Rodríguez-Lugo, Luis A

2005-06-01

To estimate the proportion of diabetes, obesity and non-optimum blood pressure levels in a group of employees of the University of Puerto Rico Medical Sciences Campus that participated in a diabetes health fair at the "Centro de Diabetes para Puerto Rico". A total of 113 participants of the diabetes health fair completed a questionnaire to obtain demographic characteristics and the frequency of self-reported diabetes. The nursing staff examined the participants in order to obtain the following clinical characteristics: body mass index, blood pressure and blood glucose levels. The proportion of self-reported diabetes, obesity (> or = 30 kg/m2) and non-optimum blood pressure levels (systolic > or = 20 mm/Hg or diastolic > or = 80 mm/Hg) were 15.4% (95% CI: 8.5% - 25.7%), 80.0% (95% CI: 70.8%-86.9%) and 70.5% (95% CI: 61.1%-78.6%), respectively. Although it was not statistically significant, diabetes was higher among females (15.4%) compared to males (12.0%). All participants with self-reported diabetes were overweight or obese, and 91.7% showed non-optimum blood pressure levels. A significant positive correlation (p < 0.001) was observed between blood pressure levels and body mass index (r = 0.3). The percentage of persons with diabetes, obesity, and non-optimum blood pressure levels in this sample of Medical Sciences Campus employees underscores the need for confirming these results in a larger study and developing strategies focused on reducing health risks in this population.

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,…

Observations on the use of human chorionic gonadotrophin (HCG) during the post-insemination period on conception rates in synchronized beef cows with sub-optimum reproductive performances.

PubMed

Holness, D H; McCabe, C T; Sprowson, G W

1982-02-01

Oestrus was synchronized in 46 Afrikaner and Mashona beef cows by two injections of cloprostenol 11 days apart. All cows had a history of sub-optimum reproductive performance. Cows were inseminated up to three times after the second cloprostenol injection on the basis of observed oestrus and changes in the conductivity of cervical mucus. Half the cows received daily injections of 1000 i.u. HcG from days four to 19 after their last insemination; the other half received daily injections of 2 ml saline over the same period. Concentrations of progesterone in plasma was determined from samples taken on days 6, 8 and 22 after the last insemination. Treatment did not significantly affect conception rate and overall conception rate was 39 per cent. On day 8 after insemination none of the 8 cows that had progesterone levels of less than 1 ng/ml were pregnant when examined at day 70. Mean progesterone concentrations were not significantly different between treated and control cows on days 6 and 8, but were significantly higher (P<0,05) in treated cows by day 22. The practical significance of using HcG to stimulate luteal function in the early post-inseminaion period is discussed.

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.

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

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).

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.

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.

Chronic myelomonocytic leukemia masquerading as cutaneous indeterminate dendritic cell tumor: Expanding the spectrum of skin lesions in chronic myelomonocytic leukemia.

PubMed

Loghavi, Sanam; Curry, Jonathan L; Garcia-Manero, Guillermo; Patel, Keyur P; Xu, Jie; Khoury, Joseph D; Torres-Cabala, Carlos A; Nagarajan, Priyadharsini; Aung, Phyu P; Gibson, Bernard R; Goodwin, Brandon P; Kelly, Brent C; Korivi, Brinda R; Medeiros, L Jeffrey; Prieto, Victor G; Kantarjian, Hagop M; Bueso-Ramos, Carlos E; Tetzlaff, Michael T

2017-12-01

Chronic myelomonocytic leukemia (CMML) is a hematopoietic stem cell neoplasm exhibiting both myelodysplastic and myeloproliferative features. Cutaneous involvement by CMML is critical to recognize as it typically is a harbinger of disease progression and an increased incidence of transformation to acute myeloid leukemia. Cutaneous lesions of CMML exhibit heterogeneous histopathologic features that can be challenging to recognize as CMML. We describe a 67-year-old man with a 3-year history of CMML who had been managed on single-agent azacitidine with stable disease before developing splenomegaly and acute onset skin lesions. Examination of these skin lesions revealed a dense infiltrate of histiocytic cells morphologically resembling Langerhans type cells (lacking frank histopathologic atypia), and with the immunophenotype of an indeterminate cell histiocytosis (S100+ CD1a+ and langerin-). Given the history of CMML, next-generation sequencing studies were performed on the skin biopsy. These revealed a KRAS (p.G12R) mutation identical to that seen in the CMML 3 years prior, establishing a clonal relationship between the 2 processes. This case expands the spectrum for and underscores the protean nature of cutaneous involvement by CMML and underscores the importance of heightened vigilance when evaluating skin lesions of CMML patients. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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.

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...

Optimum conditions for L-glutaminase production by actinomycete strain isolated from estuarine fish, Chanos chanos (Forskal, 1775).

PubMed

Sivakumar, K; Sahu, Maloy Kumar; Manivel, P R; Kannan, L

2006-03-01

Actinomycetes were isolated from skin, gills and gut contents of estuarine fish. Chanos chanos using Kuster's agar medium. Out of 20 strains tested, the strain LG-10 which was tentatively identified as Streptomyces rimosus showed L-glutaminase activity. Optimum production of L-glutaminase enzyme (17.51 IU/ml) was observed after 96 h of incubation at 27 degrees C, pH 9 and glucose and malt extract as carbon and nitrogen sources, respectively. The present study indicated scope for the use of S. rimosus as an ideal organism for the industrial production of extracellular L-glutaminase.

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.

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.

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.

Fault Slip Distribution and Optimum Sea Surface Displacement of the 2017 Tehuantepec Earthquake in Mexico (Mw 8.2) Estimated from Tsunami Waveforms

NASA Astrophysics Data System (ADS)

Gusman, A. R.; Satake, K.; Mulia, I. E.

2017-12-01

An intraplate normal fault earthquake (Mw 8.2) occurred on 8 September 2017 in the Tehuantepec seismic gap of the Middle America Trench. The submarine earthquake generated a tsunami which was recorded by coastal tide gauges and offshore DART buoys. We used the tsunami waveforms recorded at 16 stations to estimate the fault slip distribution and an optimum sea surface displacement of the earthquake. A steep fault dipping to the northeast with strike of 315°, dip of 73°and rake of -96° based on the USGS W-phase moment tensor solution was assumed for the slip inversion. To independently estimate the sea surface displacement without assuming earthquake fault parameters, we used the B-spline function for the unit sources. The distribution of the unit sources was optimized by a Genetic Algorithm - Pattern Search (GA-PS) method. Tsunami waveform inversion resolves a spatially compact region of large slip (4-10 m) with a dimension of 100 km along the strike and 80 km along the dip in the depth range between 40 km and 110 km. The seismic moment calculated from the fault slip distribution with assumed rigidity of 6 × 1010 Nm-2 is 2.46 × 1021 Nm (Mw 8.2). The optimum displacement model suggests that the sea surface was uplifted up to 0.5 m and subsided down to -0.8 m. The deep location of large fault slip may be the cause of such small sea surface displacements. The simulated tsunami waveforms from the optimum sea surface displacement can reproduce the observations better than those from fault slip distribution; the normalized root mean square misfit for the sea surface displacement is 0.89, while that for the fault slip distribution is 1.04. We simulated the tsunami propagation using the optimum sea surface displacement model. Large tsunami amplitudes up to 2.5 m were predicted to occur inside and around a lagoon located between Salina Cruz and Puerto Chiapas. Figure 1. a) Sea surface displacement for the 2017 Tehuantepec earthquake estimated by tsunami waveforms. b

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

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.

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.

Optimum data weighting and error calibration for estimation of gravitational parameters

NASA Technical Reports Server (NTRS)

Lerch, Francis J.

1989-01-01

A new technique was developed for the weighting of data from satellite tracking systems in order to obtain an optimum least-squares solution and an error calibration for the solution parameters. Data sets from optical, electronic, and laser systems on 17 satellites in GEM-T1 Goddard Earth Model-T1 (GEM-T1) were employed toward application of this technique for gravity field parameters. Also GEM-T2 (31 satellites) was recently computed as a direct application of the method and is summarized. The method employs subset solutions of the data associated with the complete solution to agree with their error estimates. With the adjusted weights the process provides for an automatic calibration of the error estimates for the solution parameters. The data weights derived are generally much smaller than corresponding weights obtained from nominal values of observation accuracy or residuals. Independent tests show significant improvement for solutions with optimal weighting. The technique is general and may be applied to orbit parameters, station coordinates, or other parameters than the gravity model.

Surface-Based Observations of Contrail Occurrence Over the US, Apr. 1993 to Apr. 1994

NASA Technical Reports Server (NTRS)

Minnis, Patrick; Ayers, J. Kirk; Weaver, Steven P.

1997-01-01

Surface observers stationed at 19 U.S. Air Force Bases and Army Air Stations recorded the daytime occurrence of contrails and cloud fraction on an hourly basis for the period April 1993 through April 1994. Each observation uses one of four main categories to report contrails as unobserved, non-persistent, persistent, and indeterminate. Additional classification includes the co-occurrence of cirrus with each report. The data cover much of the continental U.S. including locations near major commercial air routes. The mean annual frequency of occurrence in unobstructed viewing conditions is 13 percent for these sites. Contrail occurrence varied substantially with location and season. Most contrails occurred during the winter months and least during the summer with a pronounced minimum during July. Although nocturnal observations are not available, it appears that the contrails have a diurnal variation that peaks during mid morning over most areas. Contrails were most often observed in areas near major commercial air corridors and least often over areas far removed from the heaviest air traffic. A significant correlation exists between mean contrail frequency and aircraft fuel usage above 7 km suggesting predictive potential for assessing future contrail effects on climate.

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 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 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.

Diagnostic Limitation of Fine-Needle Aspiration (FNA) on Indeterminate Thyroid Nodules Can Be Partially Overcome by Preoperative Molecular Analysis: Assessment of RET/PTC1 Rearrangement in BRAF and RAS Wild-Type Routine Air-Dried FNA Specimens.

PubMed

Ko, Young Sin; Hwang, Tae Sook; Kim, Ja Yeon; Choi, Yoon-La; Lee, Seung Eun; Han, Hye Seung; Kim, Wan Seop; Kim, Suk Kyeong; Park, Kyoung Sik

2017-04-12

Molecular markers are helpful diagnostic tools, particularly for cytologically indeterminate thyroid nodules. Preoperative RET/PTC1 rearrangement analysis in BRAF and RAS wild-type indeterminate thyroid nodules would permit the formulation of an unambiguous surgical plan. Cycle threshold values according to the cell count for detection of the RET/PTC1 rearrangement by real-time reverse transcription-polymerase chain reaction (RT-PCR) using fresh and routine air-dried TPC1 cells were evaluated. The correlation of RET/PTC1 rearrangement between fine-needle aspiration (FNA) and paired formalin-fixed paraffin-embedded (FFPE) specimens was analyzed. RET/PTC1 rearrangements of 76 resected BRAF and RAS wild-type classical PTCs were also analyzed. Results of RT-PCR and the Nanostring were compared. When 100 fresh and air-dried TPC1 cells were used, expression of RET/PTC1 rearrangement was detectable after 35 and 33 PCR cycles, respectively. The results of RET/PTC1 rearrangement in 10 FNA and paired FFPE papillary thyroid carcinoma (PTC) specimens showed complete correlation. Twenty-nine (38.2%) of 76 BRAF and RAS wild-type classical PTCs had RET/PTC1 rearrangement. Comparison of RET/PTC1 rearrangement analysis between RT-PCR and the Nanostring showed moderate agreement with a κ value of 0.56 ( p = 0.002). The RET/PTC1 rearrangement analysis by RT-PCR using routine air-dried FNA specimen was confirmed to be technically applicable. A significant proportion (38.2%) of the BRAF and RAS wild-type PTCs harbored RET/PTC1 rearrangements.

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.

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

Evidence for overestimation of the prevalence of malignancy in indeterminate thyroid nodules classified as Bethesda category III.

PubMed

Iskandar, Mazen E; Bonomo, Giovanni; Avadhani, Vaidehi; Persky, Mark; Lucido, David; Wang, Beverly; Marti, Jennifer L

2015-03-01

Several recent analyses of indeterminate thyroid nodules classified as Bethesda III (follicular lesion of undetermined significance) have reported considerably greater rates of malignancy than those initially reported by the Bethesda System for Reporting Cytopathology (BSRTC). These values, however, may be overestimates owing to several sources of bias, such as referral, selection, and publication biases. Our aim was to analyze the prevalence of malignancy in Bethesda III and IV thyroid nodules in a comprehensive health system less prone to institutional referral bias, excluding incidental carcinomas, and we examine the literature for publication bias. We performed a retrospective analysis with pathologic re-review of 119 patients with Bethesda III/IV cytology undergoing surgery in a comprehensive health system by examining patient and nodule characteristics. A review of the literature was performed and analyzed for publication bias. The malignancy rate in resected thyroid nodules was 13% (6/48) for Bethesda III and 28% (20/71) for Bethesda IV. There were 9 of 119 patients (8%) with incidental microcarcinomas. Age <30 years was associated with an increased risk of malignancy (odds ratio, 25.8; P = .005). Sex, nodule size, and ultrasonographic features were not associated with risk of malignancy. Analysis of the literature was indicative of publication bias for Bethesda III cohorts, with reported rates positively skewed (P = .039). In a comprehensive health system, the rate of malignancy in Bethesda III nodules was similar to the range reported by the BSRTC. Recent reports of greater rates of malignancy may be attributable to institutional referral patterns, operative selection, inclusion of incidental microcarcinomas, and publication bias. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Heterogeneity in Positive Predictive Value of RAS Mutations in Cytologically Indeterminate Thyroid Nodules.

PubMed

Nabhan, Fadi; Porter, Kyle; Lupo, Mark A; Randolph, Gregory W; Patel, Kepal N; Kloos, Richard T

2018-06-01

RAS mutations are common in the available mutational analysis of cytologically indeterminate (Cyto-I) thyroid nodules. However, their reported positive predictive value (PPV) for cancer is widely variable. The reason for this variability is unknown, and it causes clinical management uncertainty. A systematic review was performed, evaluating the PPV for cancer in RAS mutation positive Cyto-I nodules, and variables that might affect residual heterogeneity across the different studies were considered. PubMed was searched through February 22, 2017, including studies that evaluated at least one type of RAS mutation in Cyto-I nodules, including any (or all) of the Bethesda III/IV/V categories or their equivalents and where the histological diagnosis was available. The PPV residual heterogeneity was investigated after accounting for Bethesda classification, blindedness of the histopathologist to the RAS mutational status, Bethesda category-specific cancer prevalence for each study, and which RAS genes and codons were tested. This was studied using five meta-regression models fit to different sets of Bethesda classification categories: Bethesda III, IV, or V (III/IV/V); Bethesda III or IV (III/IV); Bethesda III only; Bethesda IV only; and Bethesda V only. Of 1831 studies, 23 were eligible for data inclusion. Wide ranges of PPV were found at 0-100%, 28-100%, and 0-100% in Bethesda III, IV, and V, respectively. Residual heterogeneity remained moderately high for PPV after accounting for the above moderators for Bethesda III/IV/V (21 studies; I 2  = 59.5%) and Bethesda III/IV (19 studies; I 2  = 66.0%), with significant Cochran's Q-test for residual heterogeneity (p < 0.001). Among individual Bethesda categories, residual heterogeneity was: Bethesda III (eight studies; I 2  = 89.0%), IV (12 studies; I 2  = 53.5%), and V (10 studies; I 2  = 34.4%), with significant Cochran's Q-test for Bethesda III (p < 0.001) and IV (p = 0.04). The PPV of RAS

Optimum time for intravenous cannulation after induction with sevoflurane, oxygen, and nitrous oxide in children without any premedication.

PubMed

Hasan, Abm Kamrul; Sivasankar, Raman; Nair, Salil G; Hasan, Wamia U; Latif, Zulaidi

2018-02-01

Intravenous cannulation is usually done in children after inhalational induction with volatile anesthetic agents. The optimum time for safe intravenous cannulation after induction with sevoflurane, oxygen, and nitrous oxide has been studied in premedicated children, but there is no information for the optimum time for cannulation with inhalational induction in children without premedication. The aim of this study was to determine the optimum time for intravenous cannulation after the induction of anesthesia with sevoflurane, oxygen, and nitrous oxide in children without any premedication. This is a prospective, observer-blinded, up-and-down sequential allocation study in unpremedicated ASA grade 1 children aged 2-6 years undergoing elective dental surgery. Intravenous cannulation was attempted after inhalational induction with sevoflurane, oxygen, and nitrous oxide. The timing of cannulation was considered adequate if there was no movement, coughing, or laryngospasm. The cannulation attempt for the first child was set at 4 minutes after the loss of eyelash reflex and the time for intravenous cannulation was determined by the up-and-down method using 15 seconds as step size. Probit test was used to analyze the up-down sequences for the study. The adequate time for effective cannulation after induction with sevoflurane, oxygen, and nitrous oxide in 50% and 95% of patients was 53.02 seconds (95% confidence limits, 20.23-67.76 seconds) and 87.21 seconds (95% confidence limits, 70.77-248.03 seconds), respectively. We recommend waiting for 1 minute 45 seconds (105 seconds) after the loss of eyelash reflex before attempting intravenous cannulation in pediatric patients induced with sevoflurane, oxygen, and nitrous oxide without any premedication. © 2018 John Wiley & Sons Ltd.

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.

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.

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.

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.

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.

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.

Optimum data weighting and error calibration for estimation of gravitational parameters

NASA Technical Reports Server (NTRS)

Lerch, F. J.

1989-01-01

A new technique was developed for the weighting of data from satellite tracking systems in order to obtain an optimum least squares solution and an error calibration for the solution parameters. Data sets from optical, electronic, and laser systems on 17 satellites in GEM-T1 (Goddard Earth Model, 36x36 spherical harmonic field) were employed toward application of this technique for gravity field parameters. Also, GEM-T2 (31 satellites) was recently computed as a direct application of the method and is summarized here. The method employs subset solutions of the data associated with the complete solution and uses an algorithm to adjust the data weights by requiring the differences of parameters between solutions to agree with their error estimates. With the adjusted weights the process provides for an automatic calibration of the error estimates for the solution parameters. The data weights derived are generally much smaller than corresponding weights obtained from nominal values of observation accuracy or residuals. Independent tests show significant improvement for solutions with optimal weighting as compared to the nominal weighting. The technique is general and may be applied to orbit parameters, station coordinates, or other parameters than the gravity model.

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.

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.

Strain ratio ultrasound elastography increases the accuracy of colour-Doppler ultrasound in the evaluation of Thy-3 nodules. A bi-centre university experience.

PubMed

Cantisani, Vito; Maceroni, Piero; D'Andrea, Vito; Patrizi, Gregorio; Di Segni, Mattia; De Vito, Corrado; Grazhdani, Hektor; Isidori, Andrea M; Giannetta, Elisa; Redler, Adriano; Frattaroli, Fabrizio; Giacomelli, Laura; Di Rocco, Giorgio; Catalano, Carlo; D'Ambrosio, Ferdinando

2016-05-01

To assess whether ultrasound elastography (USE) with strain ratio increases diagnostic accuracy of Doppler ultrasound in further characterisation of cytologically Thy3 thyroid nodules. In two different university diagnostic centres, 315 patients with indeterminate cytology (Thy3) in thyroid nodules aspirates were prospectively evaluated with Doppler ultrasound and strain ratio USE before surgery. Ultrasonographic features were analysed separately and together as ultrasound score, to assess sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Receiver operating characteristic (ROC) curves to identify optimal cut-off value of the strain ratio were also provided. Diagnosis on a surgical specimen was considered the standard of reference. Higher strain ratio values were found in malignant nodules, with an optimum strain ratio cut-off of 2.09 at ROC analysis. USE with strain ratio showed 90.6% sensitivity, 93% specificity, 82.8% PPV, 96.4% NPV, while US score yielded a sensitivity of 52.9%, specificity of 84.3%, PPV 55.6% and NPV 82.9%. The diagnostic gain with strain ratio was statistically significant as proved by ROC areas, which was 0.9182 for strain ratio and 0.6864 for US score. USE with strain ratio should be considered a useful additional tool to colour-Doppler US, since it improves characterisation of thyroid nodules with indeterminate cytology. • Strain ratio measurements improve differentiation of thyroid nodules with indeterminate cytology • Elastography with strain ratio is more reliable than ultrasound features and ultrasound score • Strain ratio may help to better select patients with Thy 3 nodules candidate for surgery.

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)

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.

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.

Designing an optimum pulsed magnetic field by a resistance/self-inductance/capacitance discharge system and alignment of carbon nanotubes embedded in polypyrrole matrix

NASA Astrophysics Data System (ADS)

Kazemikia, Kaveh; Bonabi, Fahimeh; Asadpoorchallo, Ali; Shokrzadeh, Majid

2015-02-01

In this work, an optimized pulsed magnetic field production apparatus is designed based on a RLC (Resistance/Self-inductance/Capacitance) discharge circuit. An algorithm for designing an optimum magnetic coil is presented. The coil is designed to work at room temperature. With a minor physical reinforcement, the magnetic flux density can be set up to 12 Tesla with 2 ms duration time. In our design process, the magnitude and the length of the magnetic pulse are the desired parameters. The magnetic field magnitude in the RLC circuit is maximized on the basis of the optimal design of the coil. The variables which are used in the optimization process are wire diameter and the number of coil layers. The coil design ensures the critically damped response of the RLC circuit. The electrical, mechanical, and thermal constraints are applied to the design process. A locus of probable magnetic flux density values versus wire diameter and coil layer is provided to locate the optimum coil parameters. Another locus of magnetic flux density values versus capacitance and initial voltage of the RLC circuit is extracted to locate the optimum circuit parameters. Finally, the application of high magnetic fields on carbon nanotube-PolyPyrrole (CNT-PPy) nano-composite is presented. Scanning probe microscopy technique is used to observe the orientation of CNTs after exposure to a magnetic field. The result shows alignment of CNTs in a 10.3 Tesla, 1.5 ms magnetic pulse.

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.

Optimum culture duration for growing oocytes to attain meiotic and fertilization competence.

PubMed

Yamochi, Takayuki; Hashimoto, Shu; Yamanaka, Masaya; Nakaoka, Yoshiharu; Morimoto, Yoshiharu

2017-12-15

To determine the optimum culture duration for porcine growing oocytes (GOs) to attain maturation competence, we examined the meiotic competence, chromatin configuration, and fertilization ability of porcine oocytes obtained from early antral follicles and cultured for 10-16 days. The survival rate of oocytes after 10 days of culture (62.8%) was similar to that of oocytes after 12 days of culture (55%) and significantly higher than that of oocytes cultured for 14 and 16 days (52.9 and 24.3%, respectively). No significant difference was observed in the diameter of ooplasm from oocytes cultured for different durations (117.4-118.3 μm). The maturation rates of surviving oocytes after 10 and 16 days of culture (38.3 and 22.7%, respectively) were significantly lower than those of oocytes cultured for 12 and 14 days, and their in vivo counterparts (52.8-62.4%). The number of oocytes with surrounded-nucleolus chromatin was significantly lower in the 10-day culture group (78.4%) as compared with 14-day culture and in vivo counterpart groups (93.6 and 95.1%, respectively). After in vitro maturation and intracytoplasmic sperm injection, no significant difference was observed in the rate of fertilization among oocytes cultured for 12 and 14 days, and their in vivo counterparts (40.5-47.2%). Thus, porcine GOs required at least 12 days to acquire meiotic and fertilization competence, and the culture duration to maximize the number of mature oocytes ranged from 12 to 14 days.

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.

Generation Process of Large-Amplitude Upper-Band Chorus Emissions Observed by Van Allen Probes

DOE PAGES

Kubota, Yuko; Omura, Yoshiharu; Kletzing, Craig; ...

2018-04-19

In this paper, we analyze large-amplitude upper-band chorus emissions measured near the magnetic equator by the Electric and Magnetic Field Instrument Suite and Integrated Science instrument package on board the Van Allen Probes. In setting up the parameters of source electrons exciting the emissions based on theoretical analyses and observational results measured by the Helium Oxygen Proton Electron instrument, we calculate threshold and optimum amplitudes with the nonlinear wave growth theory. We find that the optimum amplitude is larger than the threshold amplitude obtained in the frequency range of the chorus emissions and that the wave amplitudes grow between themore » threshold and optimum amplitudes. Finally, in the frame of the wave growth process, the nonlinear growth rates are much greater than the linear growth rates.« less

Generation Process of Large-Amplitude Upper-Band Chorus Emissions Observed by Van Allen Probes

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

Kubota, Yuko; Omura, Yoshiharu; Kletzing, Craig

In this paper, we analyze large-amplitude upper-band chorus emissions measured near the magnetic equator by the Electric and Magnetic Field Instrument Suite and Integrated Science instrument package on board the Van Allen Probes. In setting up the parameters of source electrons exciting the emissions based on theoretical analyses and observational results measured by the Helium Oxygen Proton Electron instrument, we calculate threshold and optimum amplitudes with the nonlinear wave growth theory. We find that the optimum amplitude is larger than the threshold amplitude obtained in the frequency range of the chorus emissions and that the wave amplitudes grow between themore » threshold and optimum amplitudes. Finally, in the frame of the wave growth process, the nonlinear growth rates are much greater than the linear growth rates.« less

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.

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.

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.

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.

Choice of optimum heights for registration of ionospheric response onto earthquakes

NASA Astrophysics Data System (ADS)

Krasnov, Valerii; Gotur, Ivan; Kuleshov, Yurii; Cherny, Sergei

2017-10-01

To investigate the dependence of ionospheric disturbances on height we used model calculations, and the data of seismic and ionospheric observations during the Tohoku-Oki earthquake. High-altitude dependences of "portraits" of ionospheric disturbances are calculated for a case of influence of a seismic P-wave onto the ionosphere. We compared the "portraits" of ionospheric disturbances with the "portraits" of the seismic recording. The correlation coefficient of the recordings for the height of 100 km was about 0.81, for 130 km - 0.85, for 160 km - 0.77, for 180 km - 0.76, for 200 km - 0.7, for 230 km -0.54 and for 250 km - 0.41. At the same time the maximum of F2-layer was at the height about 250 km. Thus, the height of a maximum of F2-layer was not optimum for registration of ionospheric disturbances due to the earthquake. It was preferable to carry out measurements of the ionospheric disturbances at the heights below 200 km. The profile of amplitude of the ionospheric disturbance had no sharply expressed maximum at the height of a maximum of F2-layer. Therefore it is problematic to use the approach of the thin layer for interpretation of TEC disturbances.

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.

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.

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.

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.

A method for observing gas evolution during plastic laminate cure

NASA Technical Reports Server (NTRS)

Nicholls, A. H.

1969-01-01

Polyimide, phenolic, and other resins which develop volatiles during laminating or molding cure are studied using optimum cure cycles. The specimen is placed on a platen and sealed in a plastic bag, then heated and observed for gas evolution using a binocular microscope. A cover plate is added to sumulate an autoclave.

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.

Tuning extreme ultraviolet emission for optimum coupling with multilayer mirrors for future lithography through control of ionic charge states

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

Ohashi, Hayato, E-mail: ohashi@cc.utsunomiya-u.ac.jp; Higashiguchi, Takeshi, E-mail: higashi@cc.utsunomiya-u.ac.jp; Suzuki, Yuhei

2014-01-21

We report on the identification of the optimum plasma conditions for a laser-produced plasma source for efficient coupling with multilayer mirrors at 6.x nm for beyond extreme ultraviolet lithography. A small shift to lower energies of the peak emission for Nd:YAG laser-produced gadolinium plasmas was observed with increasing laser power density. Charge-defined emission spectra were observed in electron beam ion trap (EBIT) studies and the charge states responsible identified by use of the flexible atomic code (FAC). The EBIT spectra displayed a larger systematic shift of the peak wavelength of intense emission at 6.x nm to longer wavelengths with increasingmore » ionic charge. This combination of spectra enabled the key ion stage to be confirmed as Gd{sup 18+}, over a range of laser power densities, with contributions from Gd{sup 17+} and Gd{sup 19+} responsible for the slight shift to longer wavelengths in the laser-plasma spectra. The FAC calculation also identified the origin of observed out-of-band emission and the charge states responsible.« less

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.

Achieving optimum diffraction based overlay performance

NASA Astrophysics Data System (ADS)

Leray, Philippe; Laidler, David; Cheng, Shaunee; Coogans, Martyn; Fuchs, Andreas; Ponomarenko, Mariya; van der Schaar, Maurits; Vanoppen, Peter

2010-03-01

Diffraction Based Overlay (DBO) metrology has been shown to have significantly reduced Total Measurement Uncertainty (TMU) compared to Image Based Overlay (IBO), primarily due to having no measurable Tool Induced Shift (TIS). However, the advantages of having no measurable TIS can be outweighed by increased susceptibility to WIS (Wafer Induced Shift) caused by target damage, process non-uniformities and variations. The path to optimum DBO performance lies in having well characterized metrology targets, which are insensitive to process non-uniformities and variations, in combination with optimized recipes which take advantage of advanced DBO designs. In this work we examine the impact of different degrees of process non-uniformity and target damage on DBO measurement gratings and study their impact on overlay measurement accuracy and precision. Multiple wavelength and dual polarization scatterometry are used to characterize the DBO design performance over the range of process variation. In conclusion, we describe the robustness of DBO metrology to target damage and show how to exploit the measurement capability of a multiple wavelength, dual polarization scatterometry tool to ensure the required measurement accuracy for current and future technology nodes.

[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 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

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 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

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.

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.

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.

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.

[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.

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.

Development and Seed Number in Indeterminate Soybean as Affected by Timing and Duration of Exposure to Long Photoperiods after Flowering

PubMed Central

Kantolic, Adriana G.; Slafer, Gustavo A.

2007-01-01

Background and Aims Long photoperiods from flowering to maturity have been found to delay reproductive development in soybean (Glycine max) and to increase the number of seeds per unit land area. This study was aimed to evaluate whether sensitivity to photoperiod after flowering (a) is quantitatively related to the length of exposure to long days and (b) persists throughout the whole pod-setting period. It was also evaluated whether seed number was related to changes in the duration of post-flowering phenophases. Methods Two field experiments were conducted with an indeterminate cultivar of soybean of maturity group V. In expt 1, photoperiods 2 h longer than natural daylength were applied during different numbers of days from the beginning pod stage (R3) onwards, while in expt 2 these photoperiod extensions were imposed during 9 consecutive days starting at different times between R3 and R6 (full seed) stages. Key Results There was a quantitative response of development to the number of cycles with a long photoperiod. The exposure to long photoperiods from R3 to R5 (beginning of seed growth) increased the duration of R3–R6 regardless of the timing of exposure. The stages of development comprised in the R3–R6 phase were delayed by current as well as by previous exposure to long days. A positive relationship was found between seed number and the duration of R3–R6, irrespective of the timing and length of exposure to the long photoperiod. Conclusions Sensitivity to photoperiod remained high during the reproductive period and was highly and positively coupled with the processes of generation of yield. PMID:17452381

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

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.

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.

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.

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.

Biogenic mineral production by a novel arsenic-metabolizing thermophilic bacterium from the Alvord Basin, Oregon.

PubMed

Ledbetter, Rhesa N; Connon, Stephanie A; Neal, Andrew L; Dohnalkova, Alice; Magnuson, Timothy S

2007-09-01

The Alvord Basin in southeast Oregon contains a variety of hydrothermal features which have never been microbiologically characterized. A sampling of Murky Pot (61 degrees C; pH 7.1) led to the isolation of a novel arsenic-metabolizing organism (YeAs) which produces an arsenic sulfide mineral known as beta-realgar, a mineral that has not previously been observed as a product of bacterial arsenic metabolism. YeAs was grown on a freshwater medium and utilized a variety of organic substrates, particularly carbohydrates and organic acids. The temperature range for growth was 37 to 75 degrees C (optimum, 55 degrees C), and the pH range for growth was 6.0 to 8.0 (optimum, pH 7.0 to 7.5). No growth was observed when YeAs was grown under aerobic conditions. The doubling time when the organism was grown with yeast extract and As(V) was 0.71 h. Microscopic examination revealed Gram stain-indeterminate, non-spore-forming, nonmotile, rod-shaped cells, with dimensions ranging from 0.1 to 0.2 microm wide by 3 to 10 microm long. Arsenic sulfide mineralization of cell walls and extracellular arsenic sulfide particulate deposition were observed with electron microscopy and elemental analysis. 16S rRNA gene analysis placed YeAs in the family Clostridiaceae and indicated that the organism is most closely related to the Caloramator and Thermobrachium species. The G+C content was 35%. YeAs showed no detectable respiratory arsenate reductase but did display significant detoxification arsenate reductase activity. The phylogenetic, physiological, and morphological characteristics of YeAs demonstrate that it is an anaerobic, moderately thermophilic, arsenic-reducing bacterium. This organism and its associated metabolism could have major implications in the search for innovative methods for arsenic waste management and in the search for novel biogenic mineral signatures.

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.

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

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

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

Designing nacre-like materials for simultaneous stiffness, strength and toughness: Optimum materials, composition, microstructure and size

NASA Astrophysics Data System (ADS)

Barthelat, Francois

2014-12-01

Nacre, bone and spider silk are staggered composites where inclusions of high aspect ratio reinforce a softer matrix. Such staggered composites have emerged through natural selection as the best configuration to produce stiffness, strength and toughness simultaneously. As a result, these remarkable materials are increasingly serving as model for synthetic composites with unusual and attractive performance. While several models have been developed to predict basic properties for biological and bio-inspired staggered composites, the designer is still left to struggle with finding optimum parameters. Unresolved issues include choosing optimum properties for inclusions and matrix, and resolving the contradictory effects of certain design variables. Here we overcome these difficulties with a multi-objective optimization for simultaneous high stiffness, strength and energy absorption in staggered composites. Our optimization scheme includes material properties for inclusions and matrix as design variables. This process reveals new guidelines, for example the staggered microstructure is only advantageous if the tablets are at least five times stronger than the interfaces, and only if high volume concentrations of tablets are used. We finally compile the results into a step-by-step optimization procedure which can be applied for the design of any type of high-performance staggered composite and at any length scale. The procedure produces optimum designs which are consistent with the materials and microstructure of natural nacre, confirming that this natural material is indeed optimized for mechanical performance.

Optimum shape control of flexible beams by piezo-electric actuators

NASA Technical Reports Server (NTRS)

Baz, A.; Poh, S.

1987-01-01

The utilization of piezoelectric actuators in controlling the static deformation and shape of flexible beams is examined. An optimum design procedure is presented to enable the selection of the optimal location, thickness and excitation voltage of the piezoelectric actuators in a way that would minimize the deflection of the beam to which these actuators are bonded. Numerical examples are presented to illustrate the application of the developed optimization procedure in minimizing structural deformation of beams using ceramic and polymeric piezoelectric actuators bonded to the beams with a typical bonding agent. The obtained results emphasize the importance of the devised rational produce in designing beam-actuator systems with minimal elastic distortions.

Optimum soil frost depth to alleviate climate change effects in cold region agriculture

NASA Astrophysics Data System (ADS)

Yanai, Yosuke; Iwata, Yukiyoshi; Hirota, Tomoyoshi

2017-03-01

On-farm soil frost control has been used for the management of volunteer potatoes (Solanum tuberosum L.), a serious weed problem caused by climate change, in northern Japan. Deep soil frost penetration is necessary for the effective eradication of unharvested small potato tubers; however, this process can delay soil thaw and increase soil wetting in spring, thereby delaying agricultural activity initiation and increasing nitrous oxide emissions from soil. Conversely, shallow soil frost development helps over-wintering of unharvested potato tubers and nitrate leaching from surface soil owing to the periodic infiltration of snowmelt water. In this study, we synthesised on-farm snow cover manipulation experiments to determine the optimum soil frost depth that can eradicate unharvested potato tubers without affecting agricultural activity initiation while minimising N pollution from agricultural soil. The optimum soil frost depth was estimated to be 0.28-0.33 m on the basis of the annual maximum soil frost depth. Soil frost control is a promising practice to alleviate climate change effects on agriculture in cold regions, which was initiated by local farmers and further promoted by national and local research institutes.

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.

Optimum soil frost depth to alleviate climate change effects in cold region agriculture.

PubMed

Yanai, Yosuke; Iwata, Yukiyoshi; Hirota, Tomoyoshi

2017-03-21

On-farm soil frost control has been used for the management of volunteer potatoes (Solanum tuberosum L.), a serious weed problem caused by climate change, in northern Japan. Deep soil frost penetration is necessary for the effective eradication of unharvested small potato tubers; however, this process can delay soil thaw and increase soil wetting in spring, thereby delaying agricultural activity initiation and increasing nitrous oxide emissions from soil. Conversely, shallow soil frost development helps over-wintering of unharvested potato tubers and nitrate leaching from surface soil owing to the periodic infiltration of snowmelt water. In this study, we synthesised on-farm snow cover manipulation experiments to determine the optimum soil frost depth that can eradicate unharvested potato tubers without affecting agricultural activity initiation while minimising N pollution from agricultural soil. The optimum soil frost depth was estimated to be 0.28-0.33 m on the basis of the annual maximum soil frost depth. Soil frost control is a promising practice to alleviate climate change effects on agriculture in cold regions, which was initiated by local farmers and further promoted by national and local research institutes.

Retrospective cytological evaluation of indeterminate thyroid nodules according to the British Thyroid Association 2014 classification and comparison of clinical evaluation and outcomes

PubMed Central

Giusti, Massimo; Massa, Barbara; Balestra, Margherita; Calamaro, Paola; Gay, Stefano; Schiaffino, Simone; Turtulici, Giovanni; Zupo, Simonetta; Monti, Eleonora; Ansaldo, Gianluca

2017-01-01

The cytology of 130 indeterminate nodules (Thy 3) was retrospectively reviewed according to the British Thyroid Association 2014 classification. Nodules were divided into Thy 3a (atypical features) and Thy 3f (follicular lesion) categories. Histology was available as a reference for 97 nodules. Pre-surgical evaluations comprised biochemical tests, color-Doppler ultrasonography (US), semi-quantitative elastography-US (USE), contrast-enhanced US (CEUS), and mutation analysis from cytological slides. Thyroid malignancy was the final diagnosis for 19% of surgically-treated nodules. No statistically significant difference in the risk of malignancy was found between Thy 3a (26%) and Thy 3f (14%) nodules. Histology of the Thy 3a and Thy 3f nodules showed a higher incidence of Hurtle cell adenomas in Thy 3f (29%) than in Thy 3a (3%) nodules (P=0.01). The only pre-surgical difference concerned the BRAF V600E mutation, which was positive in some Thy 3a but not in any Thy 3f nodules (P=0.04). Receiver-operating characteristic (ROC) analysis was used to obtain cut-off values from US (score), USE (ELX 2/1 strain index), and CEUS (time-to-peak index and peak index) data. The cut-off values were similar for Thy 3a and Thy 3f nodules. Data showed that malignancy can be suspected if the US score is >2, ELX 1/2 strain index >1, time-to-peak index >1, and peak index <1. In a sub-group of 24 revised nodules (12 Thy 3a and 12 Thy 3f) with histology as a reference, the diagnostic power of cumulative pre-surgical analysis by means of US, USE, and CEUS showed high positive and negative predictive values (83% and 100%, respectively) for the presence of malignancy in Thy 3a and Thy 3f nodules. In conclusion, in our series of revised Thy 3 nodules, malignancy was low and displayed no significant differences between Thy 3a and Thy 3f categories. The use of cut-offs based on histology as a reference could reduce surgery. Our data support the conviction that, in mutation-negative Thy 3a and Thy

Striving for Optimum Noise-Decreasing Strategies in Critical Care: Initial Measurements and Observations.

PubMed

Disher, Timothy C; Benoit, Britney; Inglis, Darlene; Burgess, Stacy A; Ellsmere, Barbara; Hewitt, Brenda E; Bishop, Tanya M; Sheppard, Christopher L; Jangaard, Krista A; Morrison, Gavin C; Campbell-Yeo, Marsha L

To identify baseline sound levels, patterns of sound levels, and potential barriers and facilitators to sound level reduction. The study setting was neonatal and pediatric intensive care units in a tertiary care hospital. Participants were staff in both units and parents of currently hospitalized children or infants. One 24-hour sound measurements and one 4-hour sound measurement linked to observed sound events were conducted in each area of the center's neonatal intensive care unit. Two of each measurement type were conducted in the pediatric intensive care unit. Focus groups were conducted with parents and staff. Transcripts were analyzed with descriptive content analysis and themes were compared against results from quantitative measurements. Sound levels exceeded recommended standards at nearly every time point. The most common code was related to talking. Themes from focus groups included the critical care context and sound levels, effects of sound levels, and reducing sound levels-the way forward. Results are consistent with work conducted in other critical care environments. Staff and families realize that high sound levels can be a problem, but feel that the culture and context are not supportive of a quiet care space. High levels of ambient sound suggest that the largest changes in sound levels are likely to come from design and equipment purchase decisions. L10 and Lmax appear to be the best outcomes for measurement of behavioral interventions.

Random vibrations of quadratic damping systems. [optimum damping analysis for automobile suspension system

NASA Technical Reports Server (NTRS)

Sireteanu, T.

1974-01-01

An oscillating system with quadratic damping subjected to white noise excitation is replaced by a nonlinear, statistically equivalent system for which the associated Fokker-Planck equation can be exactly solved. The mean square responses are calculated and the optimum damping coefficient is determined with respect to the minimum mean square acceleration criteria. An application of these results to the optimization of automobile suspension damping is given.

A Comparison of Perceived Crisis Training Management and Optimum Training Management Techniques in the Army

DTIC Science & Technology

1980-08-27

Ambiguity and Time Management relating to crisis management are key issues for consideration in the development of this investigation. These concepts are...themselves to be optimum-management-oriented. The study indicates the possibility of continuing problems in the areas of time management contributing to

Identification of terrain cover using the optimum polarimetric classifier

NASA Technical Reports Server (NTRS)

Kong, J. A.; Swartz, A. A.; Yueh, H. A.; Novak, L. M.; Shin, R. T.

1988-01-01

A systematic approach for the identification of terrain media such as vegetation canopy, forest, and snow-covered fields is developed using the optimum polarimetric classifier. The covariance matrices for various terrain cover are computed from theoretical models of random medium by evaluating the scattering matrix elements. The optimal classification scheme makes use of a quadratic distance measure and is applied to classify a vegetation canopy consisting of both trees and grass. Experimentally measured data are used to validate the classification scheme. Analytical and Monte Carlo simulated classification errors using the fully polarimetric feature vector are compared with classification based on single features which include the phase difference between the VV and HH polarization returns. It is shown that the full polarimetric results are optimal and provide better classification performance than single feature measurements.

Optimum radars and filters for the passive sphere system

NASA Technical Reports Server (NTRS)

Luers, J. K.; Soltes, A.

1971-01-01

Studies have been conducted to determine the influence of the tracking radar and data reduction technique on the accuracy of the meteorological measurements made in the 30 to 100 kilometer altitude region by the ROBIN passive falling sphere. A survey of accuracy requirements was made of agencies interested in data from this region of the atmosphere. In light of these requirements, various types of radars were evaluated to determine the tracking system most applicable to the ROBIN, and methods were developed to compute the errors in wind and density that arise from noise errors in the radar supplied data. The effects of launch conditions on the measurements were also examined. Conclusions and recommendations have been made concerning the optimum tracking and data reduction techniques for the ROBIN falling sphere system.

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.

The Optimum Dataset method - examples of the application

NASA Astrophysics Data System (ADS)

Błaszczak-Bąk, Wioleta; Sobieraj-Żłobińska, Anna; Wieczorek, Beata

2018-01-01

Data reduction is a procedure to decrease the dataset in order to make their analysis more effective and easier. Reduction of the dataset is an issue that requires proper planning, so after reduction it meets all the user's expectations. Evidently, it is better if the result is an optimal solution in terms of adopted criteria. Within reduction methods, which provide the optimal solution there is the Optimum Dataset method (OptD) proposed by Błaszczak-Bąk (2016). The paper presents the application of this method for different datasets from LiDAR and the possibility of using the method for various purposes of the study. The following reduced datasets were presented: (a) measurement of Sielska street in Olsztyn (Airbrone Laser Scanning data - ALS data), (b) measurement of the bas-relief that is on the building in Gdańsk (Terrestrial Laser Scanning data - TLS data), (c) dataset from Biebrza river measurment (TLS data).

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

Optimum size of nanorods for heating application

NASA Astrophysics Data System (ADS)

Seshadri, G.; Thaokar, Rochish; Mehra, Anurag

2014-08-01

Magnetic nanoparticles (MNP's) have become increasingly important in heating applications such as hyperthermia treatment of cancer due to their ability to release heat when a remote external alternating magnetic field is applied. It has been shown that the heating capability of such particles varies significantly with the size of particles used. In this paper, we theoretically evaluate the heating capability of rod-shaped MNP's and identify conditions under which these particles display highest efficiency. For optimally sized monodisperse particles, the power generated by rod-shaped particles is found to be equal to that generated by spherical particles. However, for particles which are not mono dispersed, rod-shaped particles are found to be more effective in heating as a result of the greater spread in the power density distribution curve. Additionally, for rod-shaped particles, a dispersion in the radius of the particle contributes more to the reduction in loss power when compared to a dispersion in the length. We further identify the optimum size, i.e the radius and length of nanorods, given a bi-variate log-normal distribution of particle size in two dimensions.

The optimum intermediate pressure of two-stages vapor compression refrigeration cycle for Air-Conditioning unit

NASA Astrophysics Data System (ADS)

Ambarita, H.; Sihombing, H. V.

2018-03-01

Vapor compression cycle is mainly employed as a refrigeration cycle in the Air-Conditioning (AC) unit. In order to save energy, the Coefficient of Performance (COP) of the need to be improved. One of the potential solutions is to modify the system into multi-stages vapor compression cycle. The suitable intermediate pressure between the high and low pressures is one of the design issues. The present work deals with the investigation of an optimum intermediate pressure of two-stages vapor compression refrigeration cycle. Typical vapor compression cycle that is used in AC unit is taken into consideration. The used refrigerants are R134a. The governing equations have been developed for the systems. An inhouse program has been developed to solve the problem. COP, mass flow rate of the refrigerant and compressor power as a function of intermediate pressure are plotted. It was shown that there exists an optimum intermediate pressure for maximum COP. For refrigerant R134a, the proposed correlations need to be revised.

Social optimum for evening commute in a single-entry traffic corridor with no early departures

NASA Astrophysics Data System (ADS)

Li, Chuan-Yao; Xu, Guang-Ming; Tang, Tie-Qiao

2018-07-01

In this paper, we investigate the evening commute behaviors on the social optimum (SO) state in a single-entry traffic corridor with no early departures. Differing from the previous studies on evening commute, the dynamic properties of traffic flow are analyzed with the LWR (Lighthill-Whitham-Richards) model. The properties of optimum cumulative inflow curve with general desired departure time distribution curve are deduced, and then the analytic solutions for common desired departure time in SO are obtained. Three numerical examples are carried out to capture the characteristics of evening commuting behaviors under different values of time. The analytic and numerical results both indicate that the rarefaction wave originating from the first entry point influences the whole or part of the outflow curve. No shock wave exists through the commuting process. In addition, the cost curves show that the trip cost increases and the departure delay cost decreases with departure time, whereas the travel time cost first increases then decreases with departure time under the SO principle.

Relativity and indeterminism

NASA Astrophysics Data System (ADS)

Byrne, Patrick H.

1981-12-01

It is well known that Albert Einstein adhered to a deterministic world view throughout his career. Nevertheless, his developments of the special and general theories of relativity prove to be incompatible with that world view. Two different forms of determinism—classical Laplacian determinism and the determinism of isolated systems—are considered. Through careful considerations of what concretely is involved in predicting future states of the entire universe, or of isolated systems, it is shown that the demands of the theories of relativity make these deterministic positions untenable.

Use of a skin adhesive (octyl-2-cyanoacrylate) and the optimum reinforcing combination for suturing wounds.

PubMed

Chigira, Miho; Akimoto, Masataka

2005-01-01

The adhesion strength of a skin adhesive, octyl-2-cyanoacrylate (Dermabond), was measured under various conditions using porcine skin. The combined use of a skin adhesive and a skin closure tape (n = 5) was significantly stronger than a single application of skin adhesive (n = 5) (p < 0.01). We have tentatively named the wound closure in which a skin adhesive and reinforcement material were combined the Reinforcing Combination Method. To obtain optimum conditions, further studies were done for sequence of application, type of reinforcement material, a number of layers, and width of the suture. The optimum condition for the reinforcement combination was established by applying one layer of skin adhesive over a skin closure tape, over one layer of skin adhesive, with a suture width of 4 cm. This reinforcement combination might be useful in clinical practice.

Hyperspectral venous image quality assessment for optimum illumination range selection based on skin tone characteristics

PubMed Central

2014-01-01

Background Subcutaneous veins localization is usually performed manually by medical staff to find suitable vein to insert catheter for medication delivery or blood sample function. The rule of thumb is to find large and straight enough vein for the medication to flow inside of the selected blood vessel without any obstruction. The problem of peripheral difficult venous access arises when patient’s veins are not visible due to any reason like dark skin tone, presence of hair, high body fat or dehydrated condition, etc. Methods To enhance the visibility of veins, near infrared imaging systems is used to assist medical staff in veins localization process. Optimum illumination is crucial to obtain a better image contrast and quality, taking into consideration the limited power and space on portable imaging systems. In this work a hyperspectral image quality assessment is done to get the optimum range of illumination for venous imaging system. A database of hyperspectral images from 80 subjects has been created and subjects were divided in to four different classes on the basis of their skin tone. In this paper the results of hyper spectral image analyses are presented in function of the skin tone of patients. For each patient, four mean images were constructed by taking mean with a spectral span of 50 nm within near infrared range, i.e. 750–950 nm. Statistical quality measures were used to analyse these images. Conclusion It is concluded that the wavelength range of 800 to 850 nm serve as the optimum illumination range to get best near infrared venous image quality for each type of skin tone. PMID:25087016

Automated Decisional Model for Optimum Economic Order Quantity Determination Using Price Regressive Rates

NASA Astrophysics Data System (ADS)

Roşu, M. M.; Tarbă, C. I.; Neagu, C.

2016-11-01

The current models for inventory management are complementary, but together they offer a large pallet of elements for solving complex problems of companies when wanting to establish the optimum economic order quantity for unfinished products, row of materials, goods etc. The main objective of this paper is to elaborate an automated decisional model for the calculus of the economic order quantity taking into account the price regressive rates for the total order quantity. This model has two main objectives: first, to determine the periodicity when to be done the order n or the quantity order q; second, to determine the levels of stock: lighting control, security stock etc. In this way we can provide the answer to two fundamental questions: How much must be ordered? When to Order? In the current practice, the business relationships with its suppliers are based on regressive rates for price. This means that suppliers may grant discounts, from a certain level of quantities ordered. Thus, the unit price of the products is a variable which depends on the order size. So, the most important element for choosing the optimum for the economic order quantity is the total cost for ordering and this cost depends on the following elements: the medium price per units, the stock cost, the ordering cost etc.

Analytical and experimental studies of an optimum multisegment phased liner noise suppression concept

NASA Technical Reports Server (NTRS)

Sawdy, D. T.; Beckemeyer, R. J.; Patterson, J. D.

1976-01-01

Results are presented from detailed analytical studies made to define methods for obtaining improved multisegment lining performance by taking advantage of relative placement of each lining segment. Properly phased liner segments reflect and spatially redistribute the incident acoustic energy and thus provide additional attenuation. A mathematical model was developed for rectangular ducts with uniform mean flow. Segmented acoustic fields were represented by duct eigenfunction expansions, and mode-matching was used to ensure continuity of the total field. Parametric studies were performed to identify attenuation mechanisms and define preliminary liner configurations. An optimization procedure was used to determine optimum liner impedance values for a given total lining length, Mach number, and incident modal distribution. Optimal segmented liners are presented and it is shown that, provided the sound source is well-defined and flow environment is known, conventional infinite duct optimum attenuation rates can be improved. To confirm these results, an experimental program was conducted in a laboratory test facility. The measured data are presented in the form of analytical-experimental correlations. Excellent agreement between theory and experiment verifies and substantiates the analytical prediction techniques. The results indicate that phased liners may be of immediate benefit in the development of improved aircraft exhaust duct noise suppressors.

Optimum systems design with random input and output applied to solar water heating

NASA Astrophysics Data System (ADS)

Abdel-Malek, L. L.

1980-03-01

Solar water heating systems are evaluated. Models were developed to estimate the percentage of energy supplied from the Sun to a household. Since solar water heating systems have random input and output queueing theory, birth and death processes were the major tools in developing the models of evaluation. Microeconomics methods help in determining the optimum size of the solar water heating system design parameters, i.e., the water tank volume and the collector area.

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.

New Raman-peak at 1850 cm(-1) observed in multiwalled carbon nanotubes produced by hydrogen arc discharge.

PubMed

Chen, B; Kadowaki, Y; Inoue, S; Ohkohchi, M; Zhao, X; Ando, Y

2010-06-01

The new peak (near 1850 cm(-1)) assigned to carbon linear chain included in the centre of very thin innermost multiwalled carbon nanotubes (MWNTs) has been verified by Raman spectroscopy. These MWNTs were produced by dc arc discharge of pure graphite rods in pure hydrogen gas and existed in the cathode deposit. In this paper, we clarified that the new Raman-peaks could also be observed in the cathode deposit including MWNTs produced by hydrogen dc arc discharge using graphite electrode with added Y or La. By changing the quantity of addition (Y or La), dc arc current and pressure of ambient hydrogen gas, the optimum condition to get maximum intensity of the new Raman-peaks was obtained. For the case of 1 wt% La, dc 50 A, H2 pressure of 50 Torr was found to be optimum, and the intensity of new Raman-peak was even higher than the G-band peak. For the case of 1 wt% Y, dc 50 A, H2 pressure of 50 Torr was optimum, but the intensity of new Raman-peak was weaker than the G-band peak. Transmission electron microscopy observation revealed that the crystallinity of MWNTs produced with pure graphite rod was better than those produced with added Y or La.

Calculating Optimum sowing factor: A tool to evaluate sowing strategies and minimize seedling production cost

Treesearch

Eric van Steenis

2013-01-01

This paper illustrates how to use an excel spreadsheet as a decision-making tool to determine optimum sowing factor to minimize seedling production cost. Factors incorporated into the spreadsheet calculations include germination percentage, seeder accuracy, cost per seed, cavities per block, costs of handling, thinning, and transplanting labor, and more. In addition to...

Evaluation of optimum room entry times for radiation therapists after high energy whole pelvic photon treatments.

PubMed

Ho, Lavine; White, Peter; Chan, Edward; Chan, Kim; Ng, Janet; Tam, Timothy

2012-01-01

Linear accelerators operating at or above 10 MV produce neutrons by photonuclear reactions and induce activation in machine components, which are a source of potential exposure for radiation therapists. This study estimated gamma dose contributions to radiation therapists during high energy, whole pelvic, photon beam treatments and determined the optimum room entry times, in terms of safety of radiation therapists. Two types of technique (anterior-posterior opposing and 3-field technique) were studied. An Elekta Precise treatment system, operating up to 18 MV, was investigated. Measurements with an area monitoring device (a Mini 900R radiation monitor) were performed, to calculate gamma dose rates around the radiotherapy facility. Measurements inside the treatment room were performed when the linear accelerator was in use. The doses received by radiation therapists were estimated, and optimum room entry times were determined. The highest gamma dose rates were approximately 7 μSv/h inside the treatment room, while the doses in the control room were close to background (~0 μSv/h) for all techniques. The highest personal dose received by radiation therapists was estimated at 5 mSv/yr. To optimize protection, radiation therapists should wait for up to11 min after beam-off prior to room entry. The potential risks to radiation therapists with standard safety procedures were well below internationally recommended values, but risks could be further decreased by delaying room entry times. Dependent on the technique used, optimum entry times ranged between 7 to 11 min. A balance between moderate treatment times versus reduction in measured equivalent doses should be considered.

Strategy for future space weather observational assets

NASA Astrophysics Data System (ADS)

Davies, Jackie; Bogdanova, Yulia; Harrison, Richard; Bisi, Mario; Hapgood, Mike

2017-04-01

Observations from an ad-hoc suite of mainly aging, scientific, space-borne assets currently underpin space weather forecasting capabilities world-wide. While efforts have begun to replace / supplement these assets - in particular with the recent launch of the DSCOVR spacecraft - it is widely accepted that there is an urgent need to accelerate these endeavours in order to mitigate the risk of losing these critical observations. It is hence opportune to critically review the possible options for the provision of space weather observations, particularly in terms of identifying the optimum vantage point(s) and the instrumentation that will provide the most beneficial measurements to support space weather prediction. Here we present the results of several recent European studies that aim to identify the best solution for space-based space weather monitoring - obviously within realistic financial constraints and bearing in mind the immediacy with which such a mission needs to be realised.

Influence of operating conditions on the optimum design of electric vehicle battery cooling plates

NASA Astrophysics Data System (ADS)

Jarrett, Anthony; Kim, Il Yong

2014-01-01

The efficiency of cooling plates for electric vehicle batteries can be improved by optimizing the geometry of internal fluid channels. In practical operation, a cooling plate is exposed to a range of operating conditions dictated by the battery, environment, and driving behaviour. To formulate an efficient cooling plate design process, the optimum design sensitivity with respect to each boundary condition is desired. This determines which operating conditions must be represented in the design process, and therefore the complexity of designing for multiple operating conditions. The objective of this study is to determine the influence of different operating conditions on the optimum cooling plate design. Three important performance measures were considered: temperature uniformity, mean temperature, and pressure drop. It was found that of these three, temperature uniformity was most sensitive to the operating conditions, especially with respect to the distribution of the input heat flux, and also to the coolant flow rate. An additional focus of the study was the distribution of heat generated by the battery cell: while it is easier to assume that heat is generated uniformly, by using an accurate distribution for design optimization, this study found that cooling plate performance could be significantly improved.

Sustaining observations in the polar oceans.

PubMed

Abrahamsen, E P

2014-09-28

Polar oceans present a unique set of challenges to sustained observations. Sea ice cover restricts navigation for ships and autonomous measurement platforms alike, and icebergs present a hazard to instruments deployed in the upper ocean and in shelf seas. However, the important role of the poles in the global ocean circulation provides ample justification for sustained observations in these regions, both to monitor the rapid changes taking place, and to better understand climate processes in these traditionally poorly sampled areas. In the past, the vast majority of polar measurements took place in the summer. In recent years, novel techniques such as miniature CTD (conductivity-temperature-depth) tags carried by seals have provided an explosion in year-round measurements in areas largely inaccessible to ships, and, as ice avoidance is added to autonomous profiling floats and gliders, these promise to provide further enhancements to observing systems. In addition, remote sensing provides vital information about changes taking place in sea ice cover at both poles. To make these observations sustainable into the future, improved international coordination and collaboration is necessary to gain optimum utilization of observing networks. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Sustaining observations in the polar oceans

PubMed Central

Abrahamsen, E. P.

2014-01-01

Polar oceans present a unique set of challenges to sustained observations. Sea ice cover restricts navigation for ships and autonomous measurement platforms alike, and icebergs present a hazard to instruments deployed in the upper ocean and in shelf seas. However, the important role of the poles in the global ocean circulation provides ample justification for sustained observations in these regions, both to monitor the rapid changes taking place, and to better understand climate processes in these traditionally poorly sampled areas. In the past, the vast majority of polar measurements took place in the summer. In recent years, novel techniques such as miniature CTD (conductivity–temperature–depth) tags carried by seals have provided an explosion in year-round measurements in areas largely inaccessible to ships, and, as ice avoidance is added to autonomous profiling floats and gliders, these promise to provide further enhancements to observing systems. In addition, remote sensing provides vital information about changes taking place in sea ice cover at both poles. To make these observations sustainable into the future, improved international coordination and collaboration is necessary to gain optimum utilization of observing networks. PMID:25157189

Determination of Optimum Viewing Angles for the Angular Normalization of Land Surface Temperature over Vegetated Surface

PubMed Central

Ren, Huazhong; Yan, Guangjian; Liu, Rongyuan; Li, Zhao-Liang; Qin, Qiming; Nerry, Françoise; Liu, Qiang

2015-01-01

Multi-angular observation of land surface thermal radiation is considered to be a promising method of performing the angular normalization of land surface temperature (LST) retrieved from remote sensing data. This paper focuses on an investigation of the minimum requirements of viewing angles to perform such normalizations on LST. The normally kernel-driven bi-directional reflectance distribution function (BRDF) is first extended to the thermal infrared (TIR) domain as TIR-BRDF model, and its uncertainty is shown to be less than 0.3 K when used to fit the hemispheric directional thermal radiation. A local optimum three-angle combination is found and verified using the TIR-BRDF model based on two patterns: the single-point pattern and the linear-array pattern. The TIR-BRDF is applied to an airborne multi-angular dataset to retrieve LST at nadir (Te-nadir) from different viewing directions, and the results show that this model can obtain reliable Te-nadir from 3 to 4 directional observations with large angle intervals, thus corresponding to large temperature angular variations. The Te-nadir is generally larger than temperature of the slant direction, with a difference of approximately 0.5~2.0 K for vegetated pixels and up to several Kelvins for non-vegetated pixels. The findings of this paper will facilitate the future development of multi-angular thermal infrared sensors. PMID:25825975

Determination of optimum viewing angles for the angular normalization of land surface temperature over vegetated surface.

PubMed

Ren, Huazhong; Yan, Guangjian; Liu, Rongyuan; Li, Zhao-Liang; Qin, Qiming; Nerry, Françoise; Liu, Qiang

2015-03-27

Multi-angular observation of land surface thermal radiation is considered to be a promising method of performing the angular normalization of land surface temperature (LST) retrieved from remote sensing data. This paper focuses on an investigation of the minimum requirements of viewing angles to perform such normalizations on LST. The normally kernel-driven bi-directional reflectance distribution function (BRDF) is first extended to the thermal infrared (TIR) domain as TIR-BRDF model, and its uncertainty is shown to be less than 0.3 K when used to fit the hemispheric directional thermal radiation. A local optimum three-angle combination is found and verified using the TIR-BRDF model based on two patterns: the single-point pattern and the linear-array pattern. The TIR-BRDF is applied to an airborne multi-angular dataset to retrieve LST at nadir (Te-nadir) from different viewing directions, and the results show that this model can obtain reliable Te-nadir from 3 to 4 directional observations with large angle intervals, thus corresponding to large temperature angular variations. The Te-nadir is generally larger than temperature of the slant direction, with a difference of approximately 0.5~2.0 K for vegetated pixels and up to several Kelvins for non-vegetated pixels. The findings of this paper will facilitate the future development of multi-angular thermal infrared sensors.

Optimum dimensions of power solenoids for magnetic suspension

NASA Technical Reports Server (NTRS)

Kaznacheyev, B. A.

1985-01-01

Design optimization of power solenoids for controllable and stabilizable magnetic suspensions with force compensation in a wind tunnel is shown. It is assumed that the model of a levitating body is a sphere of ferromagnetic material with constant magnetic permeability. This sphere, with a radius much smaller than its distance from the solenoid above, is to be maintained in position on the solenoid axis by balance of the vertical electromagnetic force and the force of gravitation. The necessary vertical (axial) force generated by the solenoid is expressed as a function of relevant system dimensions, solenoid design parameters, and physical properties of the body. Three families of curves are obtained which depict the solenoid power for a given force as a function of the solenoid length with either outside radius or inside radius as a variable parameter and as a function of the outside radius with inside radius as a variable parameter. The curves indicate the optimum solenoid length and outside radius, for minimum power, corresponding to a given outside radius and inside radius, respectively.

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.

Indeterminism in Classical Dynamics of Particle Motion

NASA Astrophysics Data System (ADS)

Eyink, Gregory; Vishniac, Ethan; Lalescu, Cristian; Aluie, Hussein; Kanov, Kalin; Burns, Randal; Meneveau, Charles; Szalay, Alex

2013-03-01

We show that ``God plays dice'' not only in quantum mechanics but also in the classical dynamics of particles advected by turbulent fluids. With a fixed deterministic flow velocity and an exactly known initial position, the particle motion is nevertheless completely unpredictable! In analogy with spontaneous magnetization in ferromagnets which persists as external field is taken to zero, the particle trajectories in turbulent flow remain random as external noise vanishes. The necessary ingredient is a rough advecting field with a power-law energy spectrum extending to smaller scales as noise is taken to zero. The physical mechanism of ``spontaneous stochasticity'' is the explosive dispersion of particle pairs proposed by L. F. Richardson in 1926, so the phenomenon should be observable in laboratory and natural turbulent flows. We present here the first empirical corroboration of these effects in high Reynolds-number numerical simulations of hydrodynamic and magnetohydrodynamic fluid turbulence. Since power-law spectra are seen in many other systems in condensed matter, geophysics and astrophysics, the phenomenon should occur rather widely. Fast reconnection in solar flares and other astrophysical systems can be explained by spontaneous stochasticity of magnetic field-line motion

Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

DOEpatents

Wanlass, Mark W.

1994-01-01

A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

Constraint-Based Local Search for Constrained Optimum Paths Problems

NASA Astrophysics Data System (ADS)

Pham, Quang Dung; Deville, Yves; van Hentenryck, Pascal

Constrained Optimum Path (COP) problems arise in many real-life applications and are ubiquitous in communication networks. They have been traditionally approached by dedicated algorithms, which are often hard to extend with side constraints and to apply widely. This paper proposes a constraint-based local search (CBLS) framework for COP applications, bringing the compositionality, reuse, and extensibility at the core of CBLS and CP systems. The modeling contribution is the ability to express compositional models for various COP applications at a high level of abstraction, while cleanly separating the model and the search procedure. The main technical contribution is a connected neighborhood based on rooted spanning trees to find high-quality solutions to COP problems. The framework, implemented in COMET, is applied to Resource Constrained Shortest Path (RCSP) problems (with and without side constraints) and to the edge-disjoint paths problem (EDP). Computational results show the potential significance of the approach.

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.

Optimum design for effective water transport through a double-layered porous hydrogel inspired by plant leaves

NASA Astrophysics Data System (ADS)

Kim, Hyejeong; Kim, Hyeonjeong; Huh, Hyungkyu; Hwang, Hyung Ju; Lee, Sang Joon

2014-11-01

Plant leaves are generally known to have optimized morphological structure in response to environmental changes for efficient water usage. However, the advantageous features of plant leaves are not fully utilized in engineering fields yet, since the optimum design in internal structure of plant leaves is unclear. In this study, the tissue organization of the hydraulic pathways inside plant leaves was investigated. Water transport through double-layered porous hydrogel models analogous to mesophyll cells was experimentally observed. In addition, computational experiment and theoretical analysis were applied to the model systems to find the optimal design for efficient water transport. As a result, the models with lower porosity or with pores distributed widely in the structure exhibit efficient mass transport. Our theoretical prediction supports that structural features of plant leaves guarantee sufficient water supply as survival strategy. This study may provide a new framework for investigating the biophysical principles governing the morphological optimization of plant leaves and for designing microfluidic devices to enhance mass transport ability. This study was supported by the National Research Foundation of Korea and funded by the Korean government.

Artificial Selection for Determinate Growth Habit in Soybean

USDA-ARS?s Scientific Manuscript database

Determinacy is an agronomically important trait associated with the domestication in soybean (Glycine max). Most soybean cultivars are classifiable into indeterminate and determinate growth habit, while Glycine soja, the wild progenitor of soybean, is indeterminate. Indeterminate (Dt1) and determina...

Superinsulating Polyisocyanate Based Aerogels: A Targeted Search for the Optimum Solvent System.

PubMed

Zhu, Zhiyuan; Snellings, Geert M B F; Koebel, Matthias M; Malfait, Wim J

2017-05-31

Polyisocyanate based aerogels combine ultralow thermal conductivities with better mechanical properties than silica aerogel, but these properties critically depend on the nature of the gelation solvent, perhaps more so than on any other parameter. Here, we present a systematic study of the relationship between the polyurethane-polyisocyanurate (PUR-PIR) aerogel microstructure, surface area, thermal conductivity, and density and the gelation solvent's Hansen solubility parameters for an industrially relevant PUR-PIR rigid foam formulation. We first investigated aerogels prepared in acetone-dimethyl sulfoxide (DMSO) blends and observed a minimum in thermal conductivity (λ) and maximum in specific surface area for an acetone:DMSO ratio of 85:15 v/v. We then prepared PUR-PIR aerogels in 32 different solvent blends, divided into three series with δ Dispersion , δ Polarity , and δ H-bonding fixed at 15.94, 11.30, and 7.48 MPa 1/2 , respectively, corresponding to the optimum parameters for the acetone:DMSO series. The aerogel properties display distinct dependencies on the various solubility parameters: aerogels with low thermal conductivity can be synthesized in solvents with a high δ H-bonding parameter (above 7.2) and δ Dispersion around 16.3 MPa 1/2 . In contrast, the δ Polarity parameter is of lesser importance. Our study highlights the importance of the gelation solvent, clarifies the influence of the different solvent properties, and provides a methodology for a targeted search across the solvent chemical space based on the Hansen solubility parameters.

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.

Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

DOEpatents

Wanlass, M.W.

1994-12-27

A single-junction solar cell is described having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of ''pinning'' the optimum band gap for a wide range of operating conditions at a value of 1.14[+-]0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap. 7 figures.

An automatic optimum kernel-size selection technique for edge enhancement

USGS Publications Warehouse

Chavez, Pat S.; Bauer, Brian P.

1982-01-01

Edge enhancement is a technique that can be considered, to a first order, a correction for the modulation transfer function of an imaging system. Digital imaging systems sample a continuous function at discrete intervals so that high-frequency information cannot be recorded at the same precision as lower frequency data. Because of this, fine detail or edge information in digital images is lost. Spatial filtering techniques can be used to enhance the fine detail information that does exist in the digital image, but the filter size is dependent on the type of area being processed. A technique has been developed by the authors that uses the horizontal first difference to automatically select the optimum kernel-size that should be used to enhance the edges that are contained in the image. 

Optimum Design of PIλDμ Controller for an Automatic Voltage Regulator System Using Combinatorial Test Design

PubMed Central

Sahib, Mouayad A.; Gambardella, Luca M.; Afzal, Wasif; Zamli, Kamal Z.

2016-01-01

Combinatorial test design is a plan of test that aims to reduce the amount of test cases systematically by choosing a subset of the test cases based on the combination of input variables. The subset covers all possible combinations of a given strength and hence tries to match the effectiveness of the exhaustive set. This mechanism of reduction has been used successfully in software testing research with t-way testing (where t indicates the interaction strength of combinations). Potentially, other systems may exhibit many similarities with this approach. Hence, it could form an emerging application in different areas of research due to its usefulness. To this end, more recently it has been applied in a few research areas successfully. In this paper, we explore the applicability of combinatorial test design technique for Fractional Order (FO), Proportional-Integral-Derivative (PID) parameter design controller, named as FOPID, for an automatic voltage regulator (AVR) system. Throughout the paper, we justify this new application theoretically and practically through simulations. In addition, we report on first experiments indicating its practical use in this field. We design different algorithms and adapted other strategies to cover all the combinations with an optimum and effective test set. Our findings indicate that combinatorial test design can find the combinations that lead to optimum design. Besides this, we also found that by increasing the strength of combination, we can approach to the optimum design in a way that with only 4-way combinatorial set, we can get the effectiveness of an exhaustive test set. This significantly reduced the number of tests needed and thus leads to an approach that optimizes design of parameters quickly. PMID:27829025

Data on optimum recycle aggregate content in production of new structural concrete.

PubMed

Paul, Suvash Chandra

2017-12-01

This data presented herein are the research summary of "mechanical behavior and durability performance of concrete containing recycled concrete aggregate" (Paul, 2011) [1]. The results reported in this article relate to an important parameter of optimum content of recycle concrete aggregate (RCA) in production of new concrete for both structural and non-structural applications. For the purpose of the research various types of physical, mechanical and durability tests are performed for concrete made with different percentages of RCA. Therefore, this data set can be a great help of the readers to understand the mechanism of RCA in relates to the concrete properties.

An optimum organizational structure for a large earth-orbiting multidisciplinary Space Base

NASA Technical Reports Server (NTRS)

Ragusa, J. M.

1973-01-01

The purpose of this exploratory study was 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. 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 essential finding of this research was that a four-level project type 'total matrix' model will optimize the efficiency and effectiveness of Space Base technologists.

Optimum aim point biasing in case of a planetary quarantine constraint.

NASA Technical Reports Server (NTRS)

Gedeon, G. S.; Dvornychenko, V. N.

1972-01-01

It is assumed that the probability of impact for each maneuver is the same, and that the aspects of orbit determination and execution errors of each maneuver affect only the targeting. An approximation of the equal probability of impact contour is derived. It is assumed that the quarantine constraint is satisfied if the aim point is not inside the impact contour. A method is devised to find on each contour the optimum aim point which minimizes the so-called bias velocity which is required to bring back the spacecraft from the biased aim point to the originally desired aim point. The method is an improvement over the approach presented by Light (1965), and Craven and Wolfson (1967).

Energetics and optimum motion of oscillating lifting surfaces of finite span

NASA Technical Reports Server (NTRS)

Ahmadi, A. R.; Widnall, S. E.

1986-01-01

In certain modes of animal propulsion in nature, such as bird flight and fish swimming, the efficiency compared to man-made vehicles is very high. In such cases, wing and tail motions are typically associated with relatively high Reynolds numbers, where viscous effects are confined to a thin boundary layer at the surface and a thin trailing wake. The propulsive forces, which are generated primarily by the inertial forces, can be calculated from potential-flow theory using linearized unsteady-wing theory (for small-amplitude oscillations). In the present study, a recently developed linearized, low-frequency, unsteady lifting-line theory is employed to calculate the (sectional and total) energetic quantities and optimum motion of an oscillating wing of finite span.

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.

Characterization of an Invertase with pH Tolerance and Truncation of Its N-Terminal to Shift Optimum Activity toward Neutral pH

PubMed Central

Wang, Zilong; Lu, Jian; Wei, Yutuo; Huang, Ribo

2013-01-01

Most invertases identified to date have optimal activity at acidic pH, and are intolerant to neutral or alkaline environments. Here, an acid invertase named uninv2 is described. Uninv2 contained 586 amino acids, with a 100 amino acids N-terminal domain, a catalytic domain and a C-terminal domain. With sucrose as the substrate, uninv2 activity was optimal at pH 4.5 and at 45°C. Removal of N-terminal domain of uninv2 has shifted the optimum pH to 6.0 while retaining its optimum temperaure at 45°C. Both uninv2 and the truncated enzyme retained highly stable at neutral pH at 37°C, and they were stable at their optimum pH at 4°C for as long as 30 days. These characteristics make them far superior to invertase from Saccharomyces cerevisiae, which is mostly used as industrial enzyme. PMID:23638032

Characterization of an invertase with pH tolerance and truncation of its N-terminal to shift optimum activity toward neutral pH.

PubMed

Du, Liqin; Pang, Hao; Wang, Zilong; Lu, Jian; Wei, Yutuo; Huang, Ribo

2013-01-01

Most invertases identified to date have optimal activity at acidic pH, and are intolerant to neutral or alkaline environments. Here, an acid invertase named uninv2 is described. Uninv2 contained 586 amino acids, with a 100 amino acids N-terminal domain, a catalytic domain and a C-terminal domain. With sucrose as the substrate, uninv2 activity was optimal at pH 4.5 and at 45°C. Removal of N-terminal domain of uninv2 has shifted the optimum pH to 6.0 while retaining its optimum temperaure at 45°C. Both uninv2 and the truncated enzyme retained highly stable at neutral pH at 37°C, and they were stable at their optimum pH at 4°C for as long as 30 days. These characteristics make them far superior to invertase from Saccharomyces cerevisiae, which is mostly used as industrial enzyme.

Optimum Sea Surface Displacement and Fault Slip Distribution of the 2017 Tehuantepec Earthquake (Mw 8.2) in Mexico Estimated From Tsunami Waveforms

NASA Astrophysics Data System (ADS)

Gusman, Aditya Riadi; Mulia, Iyan E.; Satake, Kenji

2018-01-01

The 2017 Tehuantepec earthquake (Mw 8.2) was the first great normal fault event ever instrumentally recorded to occur in the Middle America Trench. The earthquake generated a tsunami with an amplitude of 1.8 m (height = 3.5 m) in Puerto Chiapas, Mexico. Tsunami waveforms recorded at coastal tide gauges and offshore buoy stations were used to estimate the optimum sea surface displacement without assuming any fault. Our optimum sea surface displacement model indicated that the maximum uplift of 0.5 m is located near the trench and the maximum subsidence of 0.8 m on the coastal side near the epicenter. We then estimated the fault slip distribution that can best explain the optimum sea surface displacement assuming 10 different fault geometries. The best model suggests that a compact region of large slip (3-6 m) extends from a depth of 30 km to 90 km, centered at a depth of 60 km.

Development of a multivariate model to predict the likelihood of carcinoma in patients with indeterminate peripheral lung nodules after a nondiagnostic bronchoscopic evaluation.

PubMed

Voss, Jesse S; Iqbal, Seher; Jenkins, Sarah M; Henry, Michael R; Clayton, Amy C; Jett, James R; Kipp, Benjamin R; Halling, Kevin C; Maldonado, Fabien

2014-01-01

Studies have shown that fluorescence in situ hybridization (FISH) testing increases lung cancer detection on cytology specimens in peripheral nodules. The goal of this study was to determine whether a predictive model using clinical features and routine cytology with FISH results could predict lung malignancy after a nondiagnostic bronchoscopic evaluation. Patients with an indeterminate peripheral lung nodule that had a nondiagnostic bronchoscopic evaluation were included in this study (N = 220). FISH was performed on residual bronchial brushing cytology specimens diagnosed as negative (n = 195), atypical (n = 16), or suspicious (n = 9). FISH results included hypertetrasomy (n = 30) and negative (n = 190). Primary study end points included lung cancer status along with time to diagnosis of lung cancer or date of last clinical follow-up. Hazard ratios (HRs) were calculated using Cox proportional hazards regression model analyses, and P values < .05 were considered statistically significant. The mean age of the 220 patients was 66.7 years (range, 35-91), and most (58%) were men. Most patients (79%) were current or former smokers with a mean pack year history of 43.2 years (median, 40; range, 1-200). After multivariate analysis, hypertetrasomy FISH (HR = 2.96, P < .001), pack years (HR = 1.03 per pack year up to 50, P = .001), age (HR = 1.04 per year, P = .02), atypical or suspicious cytology (HR = 2.02, P = .04), and nodule spiculation (HR = 2.36, P = .003) were independent predictors of malignancy over time and were used to create a prediction model (C-statistic = 0.78). These results suggest that this multivariate model including test results and clinical features may be useful following a nondiagnostic bronchoscopic examination. © 2013.

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

On convergence of differential evolution over a class of continuous functions with unique global optimum.

PubMed

Ghosh, Sayan; Das, Swagatam; Vasilakos, Athanasios V; Suresh, Kaushik

2012-02-01

Differential evolution (DE) is arguably one of the most powerful stochastic real-parameter optimization algorithms of current interest. Since its inception in the mid 1990s, DE has been finding many successful applications in real-world optimization problems from diverse domains of science and engineering. This paper takes a first significant step toward the convergence analysis of a canonical DE (DE/rand/1/bin) algorithm. It first deduces a time-recursive relationship for the probability density function (PDF) of the trial solutions, taking into consideration the DE-type mutation, crossover, and selection mechanisms. Then, by applying the concepts of Lyapunov stability theorems, it shows that as time approaches infinity, the PDF of the trial solutions concentrates narrowly around the global optimum of the objective function, assuming the shape of a Dirac delta distribution. Asymptotic convergence behavior of the population PDF is established by constructing a Lyapunov functional based on the PDF and showing that it monotonically decreases with time. The analysis is applicable to a class of continuous and real-valued objective functions that possesses a unique global optimum (but may have multiple local optima). Theoretical results have been substantiated with relevant computer simulations.

Analytical and numerical calculations of optimum design frequency for focused ultrasound therapy and acoustic radiation force.

PubMed

Ergün, A Sanlı

2011-10-01

Focused ultrasound therapy relies on acoustic power absorption by tissue. The stronger the absorption the higher the temperature increase is. However, strong acoustic absorption also means faster attenuation and limited penetration depth. Hence, there is a trade-off between heat generation efficacy and penetration depth. In this paper, we formulated the acoustic power absorption as a function of frequency and attenuation coefficient, and defined two figures of merit to measure the power absorption: spatial peak of the acoustic power absorption density, and the acoustic power absorbed within the focal area. Then, we derived "rule of thumb" expressions for the optimum frequencies that maximized these figures of merit given the target depth and homogeneous tissue type. We also formulated a method to calculate the optimum frequency for inhomogeneous tissue given the tissue composition for situations where the tissue structure can be assumed to be made of parallel layers of homogeneous tissue. We checked the validity of the rules using linear acoustic field simulations. For a one-dimensional array of 4cm acoustic aperture, and for a two-dimensional array of 4×4cm(2) acoustic aperture, we found that the power absorbed within the focal area is maximized at 0.86MHz, and 0.79MHz, respectively, when the target depth is 4cm in muscle tissue. The rules on the other hand predicted the optimum frequencies for acoustic power absorption as 0.9MHz and 0.86MHz, respectively for the 1D and 2D array case, which are within 6% and 9% of the field simulation results. Because radiation force generated by an acoustic wave in a lossy propagation medium is approximately proportional to the acoustic power absorption, these rules can be used to maximize acoustic radiation force generated in tissue as well. Copyright © 2011 Elsevier B.V. All rights reserved.

Video-EEG recordings in full-term neonates of diabetic mothers: observational study.

PubMed

Castro Conde, José Ramón; González González, Nieves Luisa; González Barrios, Desiré; González Campo, Candelaria; Suárez Hernández, Yaiza; Sosa Comino, Elena

2013-11-01

To determine whether full-term newborn infants of diabetic mothers (IDM) present immature/disorganised EEG patterns in the immediate neonatal period, and whether there was any relationship with maternal glycaemic control. Cohort study with an incidental sample performed in a tertiary hospital neonatal unit. 23 IDM and 22 healthy newborns born between 2010 and 2013. All underwent video-EEG recording lasting >90 min at 48-72 h of life. We analysed the percentage of indeterminate sleep, transient sharp waves per hour and mature-for-gestational age EEG patterns (discontinuity, maximum duration of interburst interval (IBI), asynchrony, asymmetry, δ brushes, encoches frontales and α/θ rolandic activity). The group of IDM was divided into two subgroups according to maternal HbA1c: (1) HbA1c≥6% and (2) HbA1c<6%. Compared with healthy newborns, IDM presented significantly higher percentage of indeterminate sleep (57% vs 25%; p<0.001), discontinuity (2.5% vs 0%; p=0.044) and δ brushes in the bursts (6% vs 3%; p=0.024); higher duration of IBI (0.3 s vs 0 s; p=0.017); fewer encoches frontales (7/h vs 35/h; p<0.001), reduced θ/α rolandic activity (3/h vs 9/h; p<0.001); and more transient sharp waves (25/h vs 5/h; p<0.001). IDM with maternal HbA1c≥6% showed greater percentage of δ brushes in the burst (14% vs 4%; p=0.007). Full-term IDM newborns showed video-EEG features of abnormal development of brain function. Maternal HbA1c levels<6% during pregnancy could minimise the risk of cerebral dysmaturity.

Optimum Distribution of Metal Particles in the Solid-Propellant Charge in the Approximation of a One-Dimensional Flow Field in a Cylindrical Channel

NASA Astrophysics Data System (ADS)

Min'kov, L. L.; Shrager, É. R.

2015-03-01

A study has been made of ways of optimum distribution of particles of dispersed metal in the solid-propellant charge with a cylindrical central channel, which is firmly fastened to the case. The efficiency of combustion of this metal has been analyzed. Consideration has been given to the influence of the dynamic nonequilibrium of two-phase flow on the optimum distribution of metal particles in the indicated charge in the approximation of one-dimensionality of the flow field.

Morphology-controllable growth of GdVO4:Eu3+ nano/microstructures for an optimum red luminescence

NASA Astrophysics Data System (ADS)

Yang, Liusai; Li, Guangshe; Zhao, Minglei; Zheng, Jing; Guan, Xiangfeng; Li, Liping

2012-06-01

Chemically tailoring microstructures for an optimum red luminescence is a subject at the forefront of many disciplines, which still remains a challenge due to a poor knowledge about the roles of defects in structures. In this work, GdVO4 :Eu3+ nano/microstructures of different morphologies, including tomato-like, cookie-circle-like, and ellipsoidal-like nanoparticles, and microspheroids were synthesized via a simple hydrothermal route using trisodium citrate as a capping agent. During the growth processes, the types of vanadyl ions were adjusted by varying pH value to control the morphologies and nano/microstructures with the help of trisodium citrate. The possible mechanisms for the growth processes into diverse morphologies are presented. Further, a systematic study on defect characteristics pertinent to these diverse morphologies has been explored to achieve an optimum red luminescence. The ability is clearly shown to generate different nano/microstructures of diverse morphologies and varied defect concentrations, which provides a great opportunity for morphological control in tailoring the red luminescence property for many technological applications.

Morphology-controllable growth of GdVO4:Eu3+ nano/microstructures for an optimum red luminescence.

PubMed

Yang, Liusai; Li, Guangshe; Zhao, Minglei; Zheng, Jing; Guan, Xiangfeng; Li, Liping

2012-06-22

Chemically tailoring microstructures for an optimum red luminescence is a subject at the forefront of many disciplines, which still remains a challenge due to a poor knowledge about the roles of defects in structures. In this work, GdVO(4) :Eu(3+) nano/microstructures of different morphologies, including tomato-like, cookie-circle-like, and ellipsoidal-like nanoparticles, and microspheroids were synthesized via a simple hydrothermal route using trisodium citrate as a capping agent. During the growth processes, the types of vanadyl ions were adjusted by varying pH value to control the morphologies and nano/microstructures with the help of trisodium citrate. The possible mechanisms for the growth processes into diverse morphologies are presented. Further, a systematic study on defect characteristics pertinent to these diverse morphologies has been explored to achieve an optimum red luminescence. The ability is clearly shown to generate different nano/microstructures of diverse morphologies and varied defect concentrations, which provides a great opportunity for morphological control in tailoring the red luminescence property for many technological applications.

Middle Eocene Climatic Optimum linked to continental arc flare-up in Iran?

NASA Astrophysics Data System (ADS)

van der Boon, A.; Kuiper, K.; van der Ploeg, R.; Cramwinckel, M.; Honarmand, M.; Sluijs, A.; Krijgsman, W.; Langereis, C. G.

2017-12-01

A 500 kyr episode of 3-5 °C gradual global climate warming, some 40 Myr ago, has been termed the Middle Eocene climatic optimum (MECO). It has been associated with a rise in atmospheric CO2 concentrations, but the source of this carbon remains enigmatic. We show, based on new Ar-Ar ages of volcanic rocks in Iran and Azerbaijan, that the time interval spanning the MECO was associated with a massive increase in continental arc volcanism. We also collected almost 300 Ar-Ar and U-Pb ages from literature. Typically, U-Pb ages from the Eocene are slightly younger, by 3 Myr, than Ar-Ar ages. We observed that U-Pb ages are obtained mostly from intrusive rocks and therefore must reflect an intrusive stage that post-dated extrusive volcanism. Combining all ages for extrusive rocks, we show that they cluster around 40.2 Ma, exactly within the time span of the MECO (40.5-40.0 Ma). We estimate volumes of volcanism based on a shapefile of outcrops and average thickness of the sequences. We calculate CO2 estimates using a relation volcanism-CO2 that was earlier used for the Deccan traps (Tobin et al., 2017). Our calculations indicate that the volume of the Iranian middle Eocene volcanic rocks (estimated at 37000 km3) is sufficient to explain the CO2 rise during the MECO. We conclude that continental arc flare-up in the Neotethys subduction zone is a plausible candidate for causing the MECO.

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 Laser Beam Characteristics for Achieving Smoother Ablations in Laser Vision Correction.

PubMed

Verma, Shwetabh; Hesser, Juergen; Arba-Mosquera, Samuel

2017-04-01

Controversial opinions exist regarding optimum laser beam characteristics for achieving smoother ablations in laser-based vision correction. The purpose of the study was to outline a rigorous simulation model for simulating shot-by-shot ablation process. The impact of laser beam characteristics like super Gaussian order, truncation radius, spot geometry, spot overlap, and lattice geometry were tested on ablation smoothness. Given the super Gaussian order, the theoretical beam profile was determined following Lambert-Beer model. The intensity beam profile originating from an excimer laser was measured with a beam profiler camera. For both, the measured and theoretical beam profiles, two spot geometries (round and square spots) were considered, and two types of lattices (reticular and triangular) were simulated with varying spot overlaps and ablated material (cornea or polymethylmethacrylate [PMMA]). The roughness in ablation was determined by the root-mean-square per square root of layer depth. Truncating the beam profile increases the roughness in ablation, Gaussian profiles theoretically result in smoother ablations, round spot geometries produce lower roughness in ablation compared to square geometry, triangular lattices theoretically produce lower roughness in ablation compared to the reticular lattice, theoretically modeled beam profiles show lower roughness in ablation compared to the measured beam profile, and the simulated roughness in ablation on PMMA tends to be lower than on human cornea. For given input parameters, proper optimum parameters for minimizing the roughness have been found. Theoretically, the proposed model can be used for achieving smoothness with laser systems used for ablation processes at relatively low cost. This model may improve the quality of results and could be directly applied for improving postoperative surface quality.

Assessing the toxic effects of DMSO on cord blood to determine exposure time limits and the optimum concentration for cryopreservation.

PubMed

Fry, L J; Querol, S; Gomez, S G; McArdle, S; Rees, R; Madrigal, J A

2015-08-01

Advantages of using cord blood (CB) over other sources of haematopoietic progenitor cells, such as bone marrow, include the ability to cryopreserve and bank the samples until requested for a transplant. Cryopreservation requires the addition of a cryoprotectant to prevent the formation of intracellular ice during freezing. Dimethyl sulphoxide (DMSO) is commonly used at a concentration of 10% (v/v); however, there is evidence to suggest this chemical is toxic to cells as well as to patients after infusion. The toxic effects of DMSO were assessed through cell viability and in vitro functional assays in fresh and post-thaw CB samples before determining the maximum exposure time and optimal concentration for cryopreservation. A dose-dependent toxicity of DMSO was observed in fresh samples with 40% removing all viable and functional haematopoietic progenitor cells (HPC). In fresh and post-thaw analysis, minimal toxic effect was observed when cryopreservation was delayed for up to 1 h after 10% DMSO addition. After thawing, DMSO washout was superior to dilution or unmanipulated when maintained for long periods (advantage observed 1 h after thawing). Finally, the optimum concentration for cryopreserving CB was found to be 7.5 to 10% with detrimental effects observed outside of this range. These results support the use of 7.5-10% as the optimal DMSO concentration and the maximum exposure time should be limited to <1 h prior to freezing and 30 min post-thaw. © 2015 International Society of Blood Transfusion.

Design of optimum rear passivated submicron Al corrugation in very thin textured silicon back-contact back-junction solar cell for absorption enhancement up to near-infrared region

NASA Astrophysics Data System (ADS)

Abdullah, Mohd Faizol; Hashim, Abdul Manaf

2018-01-01

The optical reflection and absorption in a very thin textured back-contact back-junction silicon (Si) solar cell are investigated. The introduction of nanotexturing on front Si surface has significantly increased the absorption in the ultraviolet (UV)-visible region with a low reflection of below 0.05. The introduction of rear surface corrugation formed by a combination of SiO2-Al has successfully enhanced the absorption up to near-infrared (NI) region. The optimum crest width, periodicity, and trough depth of corrugation are derived, which lead to high absorption up to 0.97. The internal reflection and scattering that occur near the plasmonic Al corrugation are contributing to the local maximum electric field intensity in both transverse magnetic (TM) and transverse electric (TE) modes. Since there is no perpendicular electric component in TE mode, a coupling of electric field within a corrugation trough is not observed but is only observed in TM mode. On 10-μm-thick Si, the application of Si nanocones (NCs) and optimized rear Al corrugation results in 56% improvement in photogenerated current, Jsc, compared to the reference flat Si. Thinning down the Si to only 2 μm severely limits the Jsc. Our optimized Al corrugation manages to compensate net 9% and 7% Jsc loss in 2-μm Si in respect to 10-μm-thick Si for the model with and without front Si NCs. The results seem to reveal the optimum design of rear Al corrugation for the absorption enhancement from UV up to NI wavelength region.

Selection of an Optimum Air Defense Weapon Package Using MAUM (Multi-Attribute Utility Measurement).

DTIC Science & Technology

1983-06-01

SELECTION OF AN OPTIMUM AIR DEFENSE WEAPON PACKAGE USING MAUM by Wilton L. Ham June 1983 Thesis Advisor: R. G. Nickerson Approved for public release...OSSTRIUTON STATEMEN4T (of if AlRpeat) Approved for public release; distribution unlimited. I?. 01STVAGUTgOg STATE[MENT (of me ubeh’ei antered Ian...hold": do not fire except in self defense. 4. Firing Commands. These are commands issued regard- less of the weapons control in effect. There are three

Adaptive shoot and root responses collectively enhance growth at optimum temperature and limited phosphorus supply of three herbaceous legume species.

PubMed

Suriyagoda, Lalith D B; Ryan, Megan H; Renton, Michael; Lambers, Hans

2012-10-01

Studies on the effects of sub- and/or supraoptimal temperatures on growth and phosphorus (P) nutrition of perennial herbaceous species at growth-limiting P availability are few, and the impacts of temperature on rhizosphere carboxylate dynamics are not known for any species. The effect of three day/night temperature regimes (low, 20/13 °C; medium, 27/20 °C; and high, 32/25 °C) on growth and P nutrition of Cullen cinereum, Kennedia nigricans and Lotus australis was determined. The highest temperature was optimal for growth of C. cinereum, while the lowest temperature was optimal for K. nigricans and L. australis. At optimum temperatures, the relative growth rate (RGR), root length, root length per leaf area, total P content, P productivity and water-use efficiency were higher for all species, and rhizosphere carboxylate content was higher for K. nigricans and L. australis. Cullen cinereum, with a slower RGR, had long (higher root length per leaf area) and thin roots to enhance P uptake by exploring a greater volume of soil at its optimum temperature, while K. nigricans and L. australis, with faster RGRs, had only long roots (higher root length per leaf area) as a morphological adaptation, but had a higher content of carboxylates in their rhizospheres at the optimum temperature. Irrespective of the species, the amount of P taken up by a plant was mainly determined by root length, rather than by P uptake rate per unit root surface area. Phosphorus productivity was correlated with RGR and plant biomass. All three species exhibited adaptive shoot and root traits to enhance growth at their optimum temperatures at growth-limiting P supply. The species with a slower RGR (i.e. C. cinereum) showed only morphological root adaptations, while K. nigricans and L. australis, with faster RGRs, had both morphological and physiological (i.e. root carboxylate dynamics) root adaptations.

pH Optimum of Hemagglutinin-Mediated Membrane Fusion Determines Sensitivity of Influenza A Viruses to the Interferon-Induced Antiviral State and IFITMs.

PubMed

Gerlach, Thomas; Hensen, Luca; Matrosovich, Tatyana; Bergmann, Janina; Winkler, Michael; Peteranderl, Christin; Klenk, Hans-Dieter; Weber, Friedemann; Herold, Susanne; Pöhlmann, Stefan; Matrosovich, Mikhail

2017-06-01

The replication and pathogenicity of influenza A viruses (IAVs) critically depend on their ability to tolerate the antiviral interferon (IFN) response. To determine a potential role for the IAV hemagglutinin (HA) in viral sensitivity to IFN, we studied the restriction of IAV infection in IFN-β-treated human epithelial cells by using 2:6 recombinant IAVs that shared six gene segments of A/Puerto Rico/8/1934 virus (PR8) and contained HAs and neuraminidases of representative avian, human, and zoonotic H5N1 and H7N9 viruses. In A549 and Calu-3 cells, viruses displaying a higher pH optimum of HA-mediated membrane fusion, H5N1-PR8 and H7N9-PR8, were less sensitive to the IFN-induced antiviral state than their counterparts with HAs from duck and human viruses, which fused at a lower pH. The association between a high pH optimum of fusion and reduced IFN sensitivity was confirmed by using HA point mutants of A/Hong Kong/1/1968-PR8 that differed solely by their fusion properties. Furthermore, similar effects of the viral fusion pH on IFN sensitivity were observed in experiments with (i) primary human type II alveolar epithelial cells and differentiated cultures of human airway epithelial cells, (ii) nonrecombinant zoonotic and pandemic IAVs, and (iii) preparations of IFN-α and IFN-λ1. A higher pH of membrane fusion and reduced sensitivity to IFN correlated with lower restriction of the viruses in MDCK cells stably expressing the IFN-inducible transmembrane proteins IFITM2 and IFITM3, which are known to inhibit viral fusion. Our results reveal that the pH optimum of HA-driven membrane fusion of IAVs is a determinant of their sensitivity to IFN and IFITM proteins. IMPORTANCE The IFN system constitutes an important innate defense against viral infection. Substantial information is available on how IAVs avoid detection by sensors of the IFN system and disable IFN signaling pathways. Much less is known about the ability of IAVs to tolerate the antiviral activity of IFN

pH Optimum of Hemagglutinin-Mediated Membrane Fusion Determines Sensitivity of Influenza A Viruses to the Interferon-Induced Antiviral State and IFITMs

PubMed Central

Gerlach, Thomas; Hensen, Luca; Matrosovich, Tatyana; Bergmann, Janina; Winkler, Michael; Peteranderl, Christin; Klenk, Hans-Dieter; Herold, Susanne

2017-01-01

ABSTRACT The replication and pathogenicity of influenza A viruses (IAVs) critically depend on their ability to tolerate the antiviral interferon (IFN) response. To determine a potential role for the IAV hemagglutinin (HA) in viral sensitivity to IFN, we studied the restriction of IAV infection in IFN-β-treated human epithelial cells by using 2:6 recombinant IAVs that shared six gene segments of A/Puerto Rico/8/1934 virus (PR8) and contained HAs and neuraminidases of representative avian, human, and zoonotic H5N1 and H7N9 viruses. In A549 and Calu-3 cells, viruses displaying a higher pH optimum of HA-mediated membrane fusion, H5N1-PR8 and H7N9-PR8, were less sensitive to the IFN-induced antiviral state than their counterparts with HAs from duck and human viruses, which fused at a lower pH. The association between a high pH optimum of fusion and reduced IFN sensitivity was confirmed by using HA point mutants of A/Hong Kong/1/1968-PR8 that differed solely by their fusion properties. Furthermore, similar effects of the viral fusion pH on IFN sensitivity were observed in experiments with (i) primary human type II alveolar epithelial cells and differentiated cultures of human airway epithelial cells, (ii) nonrecombinant zoonotic and pandemic IAVs, and (iii) preparations of IFN-α and IFN-λ1. A higher pH of membrane fusion and reduced sensitivity to IFN correlated with lower restriction of the viruses in MDCK cells stably expressing the IFN-inducible transmembrane proteins IFITM2 and IFITM3, which are known to inhibit viral fusion. Our results reveal that the pH optimum of HA-driven membrane fusion of IAVs is a determinant of their sensitivity to IFN and IFITM proteins. IMPORTANCE The IFN system constitutes an important innate defense against viral infection. Substantial information is available on how IAVs avoid detection by sensors of the IFN system and disable IFN signaling pathways. Much less is known about the ability of IAVs to tolerate the antiviral activity of

A comparison of optimum JP and LH2 turbofan engines designed for two subsonic transport missions

NASA Technical Reports Server (NTRS)

Civinskas, K. C.

1974-01-01

The use of liquid hydrogen fuel instead of JP fuel for two subsonic commercial transports was examined. The following determinations which are important to meeting noise reduction requirements were calculated: (1) take off gross weight, (2) energy consumption, and (3) direct operating costs. The optimum engine cycles were found to be the same for both fuels.

Genetic Local Search for Optimum Multiuser Detection Problem in DS-CDMA Systems

NASA Astrophysics Data System (ADS)

Wang, Shaowei; Ji, Xiaoyong

Optimum multiuser detection (OMD) in direct-sequence code-division multiple access (DS-CDMA) systems is an NP-complete problem. In this paper, we present a genetic local search algorithm, which consists of an evolution strategy framework and a local improvement procedure. The evolution strategy searches the space of feasible, locally optimal solutions only. A fast iterated local search algorithm, which employs the proprietary characteristics of the OMD problem, produces local optima with great efficiency. Computer simulations show the bit error rate (BER) performance of the GLS outperforms other multiuser detectors in all cases discussed. The computation time is polynomial complexity in the number of users.

OUR's: Optimum Utilization of Resources; A Guide to Instructional Resources in Occupational Education. Research Pub. 77-1.

ERIC Educational Resources Information Center

Beamish, Eric; And Others

This resource guide contains over 300 entries which are available through the Optimum Utilization of Resources (OUR's) exchange system. The entries describe learning materials, such as slides, video tapes, audio tapes, films, print material, and computer assisted instructional programs, which have been developed primarily by faculty of the…

SVD-aided pseudo principal-component analysis: A new method to speed up and improve determination of the optimum kinetic model from time-resolved data

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

Oang, Key Young; Yang, Cheolhee; Muniyappan, Srinivasan

Determination of the optimum kinetic model is an essential prerequisite for characterizing dynamics and mechanism of a reaction. Here, we propose a simple method, termed as singular value decomposition-aided pseudo principal-component analysis (SAPPA), to facilitate determination of the optimum kinetic model from time-resolved data by bypassing any need to examine candidate kinetic models. We demonstrate the wide applicability of SAPPA by examining three different sets of experimental time-resolved data and show that SAPPA can efficiently determine the optimum kinetic model. In addition, the results of SAPPA for both time-resolved X-ray solution scattering (TRXSS) and transient absorption (TA) data of themore » same protein reveal that global structural changes of protein, which is probed by TRXSS, may occur more slowly than local structural changes around the chromophore, which is probed by TA spectroscopy.« less

Improving patient safety during insertion of peripheral venous catheters: an observational intervention study.

PubMed

Kampf, Günter; Reise, Gesche; James, Claudia; Gittelbauer, Kirsten; Gosch, Jutta; Alpers, Birgit

2013-01-01

Peripheral venous catheters are frequently used in hospitalized patients but increase the risk of nosocomial bloodstream infection. Evidence-based guidelines describe specific steps that are known to reduce infection risk. However, the degree of guideline implementation in clinical practice is not known. The aim of this study was to determine the use of specific steps for insertion of peripheral venous catheters in clinical practice and to implement a multimodal intervention aimed at improving both compliance and the optimum order of the steps. The study was conducted at University Hospital Hamburg. An optimum procedure for inserting a peripheral venous catheter was defined based on three evidence-based guidelines (WHO, CDC, RKI) including five steps with 1A or 1B level of evidence: hand disinfection before patient contact, skin antisepsis of the puncture site, no palpation of treated puncture site, hand disinfection before aseptic procedure, and sterile dressing on the puncture site. A research nurse observed and recorded procedures for peripheral venous catheter insertion for healthcare workers in four different departments (endoscopy, central emergency admissions, pediatrics, and dermatology). A multimodal intervention with 5 elements was established (teaching session, dummy training, e-learning tool, tablet and poster, and direct feedback), followed by a second observation period. During the last observation week, participants evaluated the intervention. In the control period, 207 insertions were observed, and 202 in the intervention period. Compliance improved significantly for four of five steps (e.g., from 11.6% to 57.9% for hand disinfection before patient contact; p<0.001, chi-square test). Compliance with skin antisepsis of the puncture site was high before and after intervention (99.5% before and 99.0% after). Performance of specific steps in the correct order also improved (e.g., from 7.7% to 68.6% when three of five steps were done; p<0.001). The

Improving patient safety during insertion of peripheral venous catheters: an observational intervention study

PubMed Central

Kampf, Günter; Reise, Gesche; James, Claudia; Gittelbauer, Kirsten; Gosch, Jutta; Alpers, Birgit

2013-01-01

Background: Peripheral venous catheters are frequently used in hospitalized patients but increase the risk of nosocomial bloodstream infection. Evidence-based guidelines describe specific steps that are known to reduce infection risk. However, the degree of guideline implementation in clinical practice is not known. The aim of this study was to determine the use of specific steps for insertion of peripheral venous catheters in clinical practice and to implement a multimodal intervention aimed at improving both compliance and the optimum order of the steps. Methods: The study was conducted at University Hospital Hamburg. An optimum procedure for inserting a peripheral venous catheter was defined based on three evidence-based guidelines (WHO, CDC, RKI) including five steps with 1A or 1B level of evidence: hand disinfection before patient contact, skin antisepsis of the puncture site, no palpation of treated puncture site, hand disinfection before aseptic procedure, and sterile dressing on the puncture site. A research nurse observed and recorded procedures for peripheral venous catheter insertion for healthcare workers in four different departments (endoscopy, central emergency admissions, pediatrics, and dermatology). A multimodal intervention with 5 elements was established (teaching session, dummy training, e-learning tool, tablet and poster, and direct feedback), followed by a second observation period. During the last observation week, participants evaluated the intervention. Results: In the control period, 207 insertions were observed, and 202 in the intervention period. Compliance improved significantly for four of five steps (e.g., from 11.6% to 57.9% for hand disinfection before patient contact; p<0.001, chi-square test). Compliance with skin antisepsis of the puncture site was high before and after intervention (99.5% before and 99.0% after). Performance of specific steps in the correct order also improved (e.g., from 7.7% to 68.6% when three of five steps

A wearable wound moisture sensor as an indicator for wound dressing change: an observational study of wound moisture and status.

PubMed

Milne, Stephen D; Seoudi, Ihab; Al Hamad, Hanadi; Talal, Talal K; Anoop, Anzila A; Allahverdi, Niloofar; Zakaria, Zain; Menzies, Robert; Connolly, Patricia

2016-12-01

Wound moisture is known to be a key parameter to ensure optimum healing conditions in wound care. This study tests the moisture content of wounds in normal practice in order to observe the moisture condition of the wound at the point of dressing change. This study is also the first large-scale observational study that investigates wound moisture status at dressing change. The WoundSense sensor is a commercially available moisture sensor which sits directly on the wound in order to find the moisture status of the wound without disturbing or removing the dressing. The results show that of the 588 dressing changes recorded, 44·9% were made when the moisture reading was in the optimum moisture zone. Of the 30 patients recruited for this study, 11 patients had an optimum moisture reading for at least 50% of the measurements before dressing change. These results suggest that a large number of unnecessary dressing changes are being made. This is a significant finding of the study as it suggests that the protocols currently followed can be modified to allow fewer dressing changes and less disturbance of the healing wound bed. © 2015 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Correlation of emphysema score with perceived malignancy of pulmonary nodules: a multi-observer study using the LIDC-IDRI CT lung database

NASA Astrophysics Data System (ADS)

Wiemker, Rafael; Bülow, Thomas; Blaffert, Thomas; Dharaiya, Ekta

2009-02-01

Presence of emphysema is recognized to be one of the single most significant risk factors in risk models for the prediction of lung cancer. Therefore, an automatically computed emphysema score would be a prime candidate as an additional numerical feature for computer aided diagnosis (CADx) for indeterminate pulmonary nodules. We have applied several histogram-based emphysema scores to 460 thoracic CT scans from the IDRI CT lung image database, and analyzed the emphysema scores in conjunction with 3000 nodule malignancy ratings of 1232 pulmonary nodules made by expert observers. Despite the emphysema being a known risk factor, we have not found any impact on the readers' malignancy rating of nodules found in a patient with higher emphysema score. We have also not found any correlation between the number of expert-detected nodules in a patient and his emphysema score, or the relative craniocaudal location of the nodules and their malignancy rating. The inter-observer agreement of the expert ratings was excellent on nodule diameter (as derived from manual delineations), good for calcification, and only modest for malignancy and shape descriptions such as spiculation, lobulation, margin, etc.

A Causal Analysis of Observed Declines in Managed Honey Bees (Apis mellifera)

PubMed Central

Staveley, Jane P.; Law, Sheryl A.; Fairbrother, Anne; Menzie, Charles A.

2013-01-01

The European honey bee (Apis mellifera) is a highly valuable, semi-free-ranging managed agricultural species. While the number of managed hives has been increasing, declines in overwinter survival, and the onset of colony collapse disorder in 2006, precipitated a large amount of research on bees' health in an effort to isolate the causative factors. A workshop was convened during which bee experts were introduced to a formal causal analysis approach to compare 39 candidate causes against specified criteria to evaluate their relationship to the reduced overwinter survivability observed since 2006 of commercial bees used in the California almond industry. Candidate causes were categorized as probable, possible, or unlikely; several candidate causes were categorized as indeterminate due to lack of information. Due to time limitations, a full causal analysis was not completed at the workshop. In this article, examples are provided to illustrate the process and provide preliminary findings, using three candidate causes. Varroa mites plus viruses were judged to be a “probable cause” of the reduced survival, while nutrient deficiency was judged to be a “possible cause.” Neonicotinoid pesticides were judged to be “unlikely” as the sole cause of this reduced survival, although they could possibly be a contributing factor. PMID:24363549

Comparison of various error functions in predicting the optimum isotherm by linear and non-linear regression analysis for the sorption of basic red 9 by activated carbon.

PubMed

Kumar, K Vasanth; Porkodi, K; Rocha, F

2008-01-15

A comparison of linear and non-linear regression method in selecting the optimum isotherm was made to the experimental equilibrium data of basic red 9 sorption by activated carbon. The r(2) was used to select the best fit linear theoretical isotherm. In the case of non-linear regression method, six error functions namely coefficient of determination (r(2)), hybrid fractional error function (HYBRID), Marquardt's percent standard deviation (MPSD), the average relative error (ARE), sum of the errors squared (ERRSQ) and sum of the absolute errors (EABS) were used to predict the parameters involved in the two and three parameter isotherms and also to predict the optimum isotherm. Non-linear regression was found to be a better way to obtain the parameters involved in the isotherms and also the optimum isotherm. For two parameter isotherm, MPSD was found to be the best error function in minimizing the error distribution between the experimental equilibrium data and predicted isotherms. In the case of three parameter isotherm, r(2) was found to be the best error function to minimize the error distribution structure between experimental equilibrium data and theoretical isotherms. The present study showed that the size of the error function alone is not a deciding factor to choose the optimum isotherm. In addition to the size of error function, the theory behind the predicted isotherm should be verified with the help of experimental data while selecting the optimum isotherm. A coefficient of non-determination, K(2) was explained and was found to be very useful in identifying the best error function while selecting the optimum isotherm.

Global warming and ocean acidification through halted weathering feedback during the Middle Eocene Climatic Optimum

NASA Astrophysics Data System (ADS)

van der Ploeg, R.; Selby, D. S.; Cramwinckel, M.; Bohaty, S. M.; Sluijs, A.; Middelburg, J. J.

2016-12-01

The Middle Eocene Climatic Optimum (MECO) represents a 500 kyr period of global warming 40 million years ago associated with a rise in atmospheric CO2 concentrations, but its cause remains enigmatic. Moreover, on the timescale of the MECO, an increase in silicate weathering rates on the continents is expected to balance carbon input and restore the alkalinity of the oceans, but this is in sharp disagreement with observations of extensive carbonate dissolution. Here we show, based on osmium isotope ratios of marine sediments from three different sites, that CO2 rise and warming did not lead to enhanced continental weathering during the MECO, in contrast to expectations from carbon cycle theory. Remarkably, a minor shift to lower, more unradiogenic osmium isotope ratios rather indicates an episode of increased volcanism or reduced continental weathering. This disproves silicate weathering as a geologically constant feedback to CO2 variations. Rather, we suggest that global Early and Middle Eocene warmth diminished the weatherability of continental rocks, ultimately leading to CO2 accumulation during the MECO, and show the plausibility of this scenario using carbon cycle modeling simulations. We surmise a dynamic weathering feedback might explain multiple enigmatic phases of coupled climate and carbon cycle change in the Cretaceous and Cenozoic.

Optimum Guidance Law and Information Management for a Large Number of Formation Flying Spacecrafts

NASA Astrophysics Data System (ADS)

Tsuda, Yuichi; Nakasuka, Shinichi

In recent years, formation flying technique is recognized as one of the most important technologies for deep space and orbital missions that involve multiple spacecraft operations. Formation flying mission improves simultaneous observability over a wide area, redundancy and reconfigurability of the system with relatively small and low cost spacecrafts compared with the conventional single spacecraft mission. From the viewpoint of guidance and control, realizing formation flying mission usually requires tight maintenance and control of the relative distances, speeds and orientations between the member satellites. This paper studies a practical architecture for formation flight missions focusing mainly on guidance and control, and describes a new guidance algorithm for changing and keeping the relative positions and speeds of the satellites in formation. The resulting algorithm is suitable for onboard processing and gives the optimum impulsive trajectory for satellites flying closely around a certain reference orbit, that can be elliptic, parabolic or hyperbolic. Based on this guidance algorithm, this study introduces an information management methodology between the member spacecrafts which is suitable for a large formation flight architecture. Routing and multicast communication based on the wireless local area network technology are introduced. Some mathematical analyses and computer simulations will be shown in the presentation to reveal the feasibility of the proposed formation flight architecture, especially when a very large number of satellites join the formation.

Time to Initiation of Antiretroviral Therapy Among Patients Who Are ART Eligible in Rwanda: Improvement Over Time

PubMed Central

Teasdale, Chloe A.; Wang, Chunhui; Francois, Uwinkindi; d’Amour Ndahimana, Jean; Vincent, Mutabazi; Sahabo, Ruben; El-Sadr, Wafaa M.; Abrams, Elaine J.

2016-01-01

Background Delayed initiation of antiretroviral therapy (ART) in eligible patients is a concern in resource-limited countries. Methods We analyzed data on HIV-positive patients ≥15 years enrolled at 41 ICAP-supported health care facilities in Rwanda, 2005–2010, to determine time to ART initiation among patients eligible at enrollment compared with those ineligible or of indeterminate eligibility who become eligible during follow-up. ART eligibility was based on CD4+ cell count (CD4+) and WHO staging; patients lacking CD4+ and WHO stage were considered indeterminate. Cumulative incidence of reaching ART eligibility and to ART initiation after eligibility was generated using competing risk estimators. Results A total of 31,033 ART-naive adults were enrolled; 64.2% were female. At enrollment, 10,158 (32.7%) patients were ART eligible, 13,372 (43.1%) were ineligible for ART, and 7503 (24.2%) patients were indeterminate. Among patients retained in care pre-ART eligibility, 17.9% [95% confidence interval (CI): 17.2 to 18.6] of ineligible and 22.8% (95% CI: 21.7 to 23.8) of indeterminate patients at enrollment reached ART eligibility within 12 months. Cumulative incidence of ART initiation within 3 months for patients eligible at enrollment was 77.2% (95% CI: 76.4 to 78.0) compared with 67.9% (95% CI: 66.4 to 69.3) for ineligible and 63.8% (95% CI: 61.9 to 65.8) for patients with indeterminate eligibility at enrollment (P < 0.05). Over the study period, there was more rapid ART initiation for patients who became ART eligible. Conclusions We found higher rates of ART initiation within 3 months among patients who were ART eligible at enrollment compared with those who reached eligibility during follow-up. From 2006 to 2011, earlier initiation of ART after eligibility was observed likely reflecting improved program quality. PMID:25415291

Optimum periodicity of repeated contractile actions applied in mass transport

NASA Astrophysics Data System (ADS)

Ahn, Sungsook; Lee, Sang Joon

2015-01-01

Dynamically repeated periodic patterns are abundant in natural and artificial systems, such as tides, heart beats, stock prices, and the like. The characteristic repeatability and periodicity are expected to be optimized in effective system-specific functions. In this study, such optimum periodicity is experimentally evaluated in terms of effective mass transport using one-valve and multi-valve systems working in contractile fluid flows. A set of nanoscale gating functions is utilized, operating in nanocomposite networks through which permeates selectively pass under characteristic contractile actions. Optimized contractile periodicity exists for effective energy impartment to flow in a one-valve system. In the sequential contractile actions for a multi-valve system, synchronization with the fluid flow is critical for effective mass transport. This study provides fundamental understanding on the various repeated periodic patterns and dynamic repeatability occurring in nature and mechanical systems, which are useful for broad applications.

Optimum Actuator Selection with a Genetic Algorithm for Aircraft Control

NASA Technical Reports Server (NTRS)

Rogers, James L.

2004-01-01

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. For example, the desired actuators produce a pure roll moment without at the same time causing much pitch or yaw. For a typical wing, 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 and mission constraints. A genetic algorithm has been developed for finding the best placement for four actuators to produce an uncoupled pitch moment. The genetic algorithm has been extended to find the minimum number of actuators required to provide uncoupled pitch, roll, and yaw control. A simplified, untapered, unswept wing is the model for each application.

Optimum Construction of Heating Coil for Domestic Induction Cooker

NASA Astrophysics Data System (ADS)

Sinha, Dola; Bandyopadhyay, Atanu; Sadhu, Pradip Kumar; Pal, Nitai

2010-10-01

The design and optimization of the parameters of heating coil is very important for the analytical analysis of high frequency inverter fed induction cooker. Moreover, accurate prediction of high frequency winding loss (i.e., losses due to skin and proximity effects) is necessary as the induction cooker used in power electronics applications. At high frequency current penetration in the induction coil circuit is very difficult for conducting wire due to skin-effect. To eradicate the skin effect heating coil is made up of bundle conductor i.e., litz wire. In this paper inductances and AC resistances of a litz-wire are calculated and optimized by considering the input parameters like wire type, shape, number of strand, number of spiral turn, number of twist per feet of heating coil and operating frequency. A high frequency half bridge series resonant mirror inverter circuit is used in this paper and taking the optimum values of inductance and ac resistance the circuit is simulated through PSPICE simulations. It has been noticed that the results are feasible enough for real implementation.

Optimum Heart Rate to Minimize Pulsatile External Cardiac Power

NASA Astrophysics Data System (ADS)

Pahlevan, Niema; Gharib, Morteza

2011-11-01

The workload on the left ventricle is composed of steady and pulsatile components. Clinical investigations have confirmed that an abnormal pulsatile load plays an important role in the pathogenesis of left ventricular hypertrophy (LVH) and progression of LVH to congestive heart failure (CHF). The pulsatile load is the result of the complex dynamics of wave propagation and reflection in the compliant arterial vasculature. We hypothesize that aortic waves can be optimized to reduce the left ventricular (LV) pulsatile load. We used an in-vitro experimental approach to investigate our hypothesis. A unique hydraulic model was used for in-vitro experiments. This model has physical and dynamical properties similar to the heart-aorta system. Different compliant models of the artificial aorta were used to test the hypothesis under various aortic rigidities. Our results indicate that: i) there is an optimum heart rate that minimizes LV pulsatile power (this is in agreement with our previous computational study); ii) introducing an extra reflection site at the specific location along the aorta creates constructive wave conditions that reduce the LV pulsatile power.

41 CFR 102-75.55 - What does the term “Not being put to optimum use” mean?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What does the term âNot being put to optimum useâ mean? 102-75.55 Section 102-75.55 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 75...

Optimum allocation of test resources and comparison of breeding strategies for hybrid wheat.

PubMed

Longin, C Friedrich H; Mi, Xuefei; Melchinger, Albrecht E; Reif, Jochen C; Würschum, Tobias

2014-10-01

The use of a breeding strategy combining the evaluation of line per se with testcross performance maximizes annual selection gain for hybrid wheat breeding. Recent experimental studies confirmed a high commercial potential for hybrid wheat requiring the design of optimum breeding strategies. Our objectives were to (1) determine the optimum allocation of the type and number of testers, the number of test locations and the number of doubled haploid lines for different breeding strategies, (2) identify the best breeding strategy and (3) elaborate key parameters for an efficient hybrid wheat breeding program. We performed model calculations using the selection gain for grain yield as target variable to optimize the number of lines, testers and test locations in four different breeding strategies. A breeding strategy (BS2) combining the evaluation of line per se performance and general combining ability (GCA) had a far larger annual selection gain across all considered scenarios than a breeding strategy (BS1) focusing only on GCA. In the combined strategy, the production of testcross seed conducted in parallel with the first yield trial for line per se performance (BS2rapid) resulted in a further increase of the annual selection gain. For the current situation in hybrid wheat, this relative superiority of the strategy BS2rapid amounted to 67 % in annual selection gain compared to BS1. Varying a large number of parameters, we identified the high costs for hybrid seed production and the low variance of GCA in hybrid wheat breeding as key parameters limiting selection gain in BS2rapid.

Optimum Image Formation for Spaceborne Microwave Radiometer Products.

PubMed

Long, David G; Brodzik, Mary J

2016-05-01

This paper considers some of the issues of radiometer brightness image formation and reconstruction for use in the NASA-sponsored Calibrated Passive Microwave Daily Equal-Area Scalable Earth Grid 2.0 Brightness Temperature Earth System Data Record project, which generates a multisensor multidecadal time series of high-resolution radiometer products designed to support climate studies. Two primary reconstruction algorithms are considered: the Backus-Gilbert approach and the radiometer form of the scatterometer image reconstruction (SIR) algorithm. These are compared with the conventional drop-in-the-bucket (DIB) gridded image formation approach. Tradeoff study results for the various algorithm options are presented to select optimum values for the grid resolution, the number of SIR iterations, and the BG gamma parameter. We find that although both approaches are effective in improving the spatial resolution of the surface brightness temperature estimates compared to DIB, SIR requires significantly less computation. The sensitivity of the reconstruction to the accuracy of the measurement spatial response function (MRF) is explored. The partial reconstruction of the methods can tolerate errors in the description of the sensor measurement response function, which simplifies the processing of historic sensor data for which the MRF is not known as well as modern sensors. Simulation tradeoff results are confirmed using actual data.

Optimum modulation and demodulation matrices for solar polarimetry.

PubMed

del Toro Iniesta, J C; Collados, M

2000-04-01

Both temporal and/or spatial modulation are mandatory in current solar polarimetry [Appl. Opt. 24, 3893 (1985); 26, 3838 (1987)]. The modulating and demodulating processes are mathematically described by matrices O and D, respectively, on whose structure the accuracy of Stokes parameter measurements depend. We demonstrate, based on the definition of polarimetric efficiency [Instituto de Astrofísica de Canarias Internal Report (1994); ASP Conf. Ser. 184, 3 (1999)], that the maximum efficiencies of an ideal polarimeter are unity for Stokes I and for (Q(2) + U(2) + V(2))(1/2) and that this occurs if and only if O(T)O is diagonal; given a general (possibly nonideal) modulation matrix O, the optimum demodulation matrix turns out to be D = (O(T)O)(-1)O(T); and the maximum efficiencies in the nonideal case are given by the rms value of the column elements of matrix O and are reached by modulation matrices such that O(T)O is diagonal. From these analytical results we distill two recipes useful in the practical design of polarimeters. Their usefulness is illustrated by discussing cases of currently available solar polarimeters. Although specifically devoted to solar polarimetry, the results here may be applied in practically all other branches of science for which polarimetric measurements are needed.

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.

75 FR 42770 - Notice of Inventory Completion: Denver Museum of Nature & Science, Denver, CO

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-22

... collected), one child of indeterminate sex, and two adults of indeterminate sex. Most of these individuals...), A533.5C (CUI 31), and A533.6A (CUI 32)). Remains include one child, which was reportedly found with... right arm bone of an adult of indeterminate sex (AC.2874; CUI 35) and two leg bones of an adult of...

Molecular Testing for miRNA, mRNA, and DNA on Fine-Needle Aspiration Improves the Preoperative Diagnosis of Thyroid Nodules With Indeterminate Cytology.

PubMed

Labourier, Emmanuel; Shifrin, Alexander; Busseniers, Anne E; Lupo, Mark A; Manganelli, Monique L; Andruss, Bernard; Wylie, Dennis; Beaudenon-Huibregtse, Sylvie

2015-07-01

Molecular testing for oncogenic mutations or gene expression in fine-needle aspirations (FNAs) from thyroid nodules with indeterminate cytology identifies a subset of benign or malignant lesions with high predictive value. This study aimed to evaluate a novel diagnostic algorithm combining mutation detection and miRNA expression to improve the diagnostic yield of molecular cytology. Surgical specimens and preoperative FNAs (n = 638) were tested for 17 validated gene alterations using the miRInform Thyroid test and with a 10-miRNA gene expression classifier generating positive (malignant) or negative (benign) results. Cross-sectional sampling of thyroid nodules with atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) or follicular neoplasm/suspicious for a follicular neoplasm (FN/SFN) cytology (n = 109) was conducted at 12 endocrinology centers across the United States. Qualitative molecular results were compared with surgical histopathology to determine diagnostic performance and model clinical effect. Mutations were detected in 69% of nodules with malignant outcome. Among mutation-negative specimens, miRNA testing correctly identified 64% of malignant cases and 98% of benign cases. The diagnostic sensitivity and specificity of the combined algorithm was 89% (95% confidence interval [CI], 73-97%) and 85% (95% CI, 75-92%), respectively. At 32% cancer prevalence, 61% of the molecular results were benign with a negative predictive value of 94% (95% CI, 85-98%). Independently of variations in cancer prevalence, the test increased the yield of true benign results by 65% relative to mRNA-based gene expression classification and decreased the rate of avoidable diagnostic surgeries by 69%. Multiplatform testing for DNA, mRNA, and miRNA can accurately classify benign and malignant thyroid nodules, increase the diagnostic yield of molecular cytology, and further improve the preoperative risk-based management of benign nodules with

Analytical network process based optimum cluster head selection in wireless sensor network.

PubMed

Farman, Haleem; Javed, Huma; Jan, Bilal; Ahmad, Jamil; Ali, Shaukat; Khalil, Falak Naz; Khan, Murad

2017-01-01

Wireless Sensor Networks (WSNs) are becoming ubiquitous in everyday life due to their applications in weather forecasting, surveillance, implantable sensors for health monitoring and other plethora of applications. WSN is equipped with hundreds and thousands of small sensor nodes. As the size of a sensor node decreases, critical issues such as limited energy, computation time and limited memory become even more highlighted. In such a case, network lifetime mainly depends on efficient use of available resources. Organizing nearby nodes into clusters make it convenient to efficiently manage each cluster as well as the overall network. In this paper, we extend our previous work of grid-based hybrid network deployment approach, in which merge and split technique has been proposed to construct network topology. Constructing topology through our proposed technique, in this paper we have used analytical network process (ANP) model for cluster head selection in WSN. Five distinct parameters: distance from nodes (DistNode), residual energy level (REL), distance from centroid (DistCent), number of times the node has been selected as cluster head (TCH) and merged node (MN) are considered for CH selection. The problem of CH selection based on these parameters is tackled as a multi criteria decision system, for which ANP method is used for optimum cluster head selection. Main contribution of this work is to check the applicability of ANP model for cluster head selection in WSN. In addition, sensitivity analysis is carried out to check the stability of alternatives (available candidate nodes) and their ranking for different scenarios. The simulation results show that the proposed method outperforms existing energy efficient clustering protocols in terms of optimum CH selection and minimizing CH reselection process that results in extending overall network lifetime. This paper analyzes that ANP method used for CH selection with better understanding of the dependencies of

Analytical network process based optimum cluster head selection in wireless sensor network

PubMed Central

Javed, Huma; Jan, Bilal; Ahmad, Jamil; Ali, Shaukat; Khalil, Falak Naz; Khan, Murad

2017-01-01

Wireless Sensor Networks (WSNs) are becoming ubiquitous in everyday life due to their applications in weather forecasting, surveillance, implantable sensors for health monitoring and other plethora of applications. WSN is equipped with hundreds and thousands of small sensor nodes. As the size of a sensor node decreases, critical issues such as limited energy, computation time and limited memory become even more highlighted. In such a case, network lifetime mainly depends on efficient use of available resources. Organizing nearby nodes into clusters make it convenient to efficiently manage each cluster as well as the overall network. In this paper, we extend our previous work of grid-based hybrid network deployment approach, in which merge and split technique has been proposed to construct network topology. Constructing topology through our proposed technique, in this paper we have used analytical network process (ANP) model for cluster head selection in WSN. Five distinct parameters: distance from nodes (DistNode), residual energy level (REL), distance from centroid (DistCent), number of times the node has been selected as cluster head (TCH) and merged node (MN) are considered for CH selection. The problem of CH selection based on these parameters is tackled as a multi criteria decision system, for which ANP method is used for optimum cluster head selection. Main contribution of this work is to check the applicability of ANP model for cluster head selection in WSN. In addition, sensitivity analysis is carried out to check the stability of alternatives (available candidate nodes) and their ranking for different scenarios. The simulation results show that the proposed method outperforms existing energy efficient clustering protocols in terms of optimum CH selection and minimizing CH reselection process that results in extending overall network lifetime. This paper analyzes that ANP method used for CH selection with better understanding of the dependencies of

Computerized LCC/ORLA methodology. [Life cycle cost/optimum repair level analysis

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

Henderson, J.T.

1979-01-01

The effort by Sandia Laboratories in developing CDC6600 computer programs for Optimum Repair Level Analysis (ORLA) and Life Cycle Cost (LCC) analysis is described. Investigation of the three repair-level strategies referenced in AFLCM/AFSCM 800-4 (base discard of subassemblies, base repair of subassemblies, and depot repair of subassemblies) was expanded to include an additional three repair-level strategies (base discard of complete assemblies and, upon shipment of complete assemblies to the depot, depot repair of assemblies by subassembly repair, and depot repair of assemblies by subassembly discard). The expanded ORLA was used directly in an LCC model that was procedurally altered tomore » accommodate the ORLA input data. Available from the LCC computer run was an LCC value corresponding to the strategy chosen from the ORLA. 2 figures.« less

Optimum survival strategies against zombie infestations - a population dynamics approach

NASA Astrophysics Data System (ADS)

Mota, Bruno

2014-03-01

We model a zombie infestation by three coupled ODEs that jointly describe the time evolution of three populations: regular humans, zombies, and survivors (humans that have survived at least one zombie encounter). This can be generalized to take into account more levels of expertise and/or skill degradation. We compute the fixed points, and stability thereof, that correspond to one of three possible outcomes: human extinction, zombie extermination or, if one allows for a human non-zero birth-rate, co-habitation. We obtain analytically the optimum strategy for humans in terms of the model's parameters (essentially, whether to flee and hide, or fight). Zombies notwithstanding, this can also be seen as a toy model for infections of immune system cells, such as CD4+ T cells in AIDS, and macrophages in tuberculosis, whereby cells are both the target of infection, and mediate the acquired immunity response against the same infection. I thank FAPERJ for financial support.

Optimum solar electric interplanetary mission opportunities from 1975 to 1990

NASA Technical Reports Server (NTRS)

Mann, F. I.; Horsewood, J. L.

1971-01-01

A collection of optimum trajectory and spacecraft data is presented for unmanned interplanetary missions from 1975 to 1990 using solar electric propulsion. Data are presented for one-way flyby and orbiter missions from Earth to Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. The solar system model assumes planetary ephemerides which very closely approximate the true motion of the planets. Direct and indirect flight profiles are investigated. Data are presented for two representative flight times for each mission. The launch vehicle is the Titan 3 B (core)/Centaur, and a constant jet exhaust speed solar electric propulsion system having a specific mass of 30 kg/kw is completely optimized in terms of power level and jet exhaust speed to yield maximum net spacecraft mass. The hyperbolic excess speeds at departure and arrival and the launch date are optimized for each mission. For orbiter missions, a chemical retro stage is used to brake the spacecraft into a highly eccentric capture orbit about the target planet.

Determination of optimum process parameters for peroxidase-catalysed treatment of bisphenol A and application to the removal of bisphenol derivatives.

PubMed

Yamada, Kazunori; Ikeda, Naoya; Takano, Yoko; Kashiwada, Ayumi; Matsuda, Kiyomi; Hirata, Mitsuo

2010-03-01

Systematic investigations were carried out to determine the optimum process parameters such as the hydrogen peroxide (H2O2) concentration, concentration and molar mass of poly(ethylene glycol) (PEG) as an additive, pH value, temperature and enzyme dose for treatment of bisphenol A (BPA) with horseradish peroxidase (HRP). The HRP-catalysed treatment of BPA was effectively enhanced by adding PEG, and BPA was completely converted into phenoxy radicals by HRP dose of 0.10 U/cm3. The optimum conditions for HRP-catalysed treatment of BPA at 0.3 mM was determined to be 0.3 mM for H2O2 and 0.10 mg/cm3 for PEG with a molar mass of 1.0 x 10(4) in a pH 6.0 buffer at 30 degrees C. Different kinds of bisphenol derivatives were completely or effectively treated by HRP under the optimum conditions determined for treatment of BPA, although the HRP dose was further increased as necessary for some of them. The aggregation of water-insoluble oligomers generated by the enzymatic radicalization and radical coupling reaction was enhanced by decreasing the pH values to 4.0 with HCl after the enzymatic treatment, and BPA and bisphenol derivatives were removed from aqueous solutions by filtering out the oligomer precipitates.

Measurement and quantum indeterminateness

NASA Astrophysics Data System (ADS)

Healey, Richard

1993-08-01

Albert and Loewer[1] have recently clarified their earlier objection to the interactive interpretation presented in Healey[2]. They now charge that this interpretation fails to solve a problem of which the measurement problem is but a special case. The general problem is to reconcile quantum mechanics with the prima facie determinateness of such dynamical properties as the positions of macroscopic objects. In response I defend both the preeminent significance of determinate measurement outcomes and the claim that the models of Healey[3] go a long way toward securing their determinateness.

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 bus system and water transportation study : staff report to the Board of Directors of Marin County Transit District

DOT National Transportation Integrated Search

1969-08-01

Describes an optimum bus system replacing existing Greyhound service and designed primarily for the purpose of meeting commuter travel demands in the San Francisco-Marin corridor as well as intra-county travel, and mid-day and weekend trips between M...

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

Observational Evidence for a Decade-long climate optimum near the Hesperian/Amazonian Transition

NASA Astrophysics Data System (ADS)

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

2012-12-01

Hesperian to Amazonian-aged valleys (HAVs) are predominantly found in the southern equatorial and mid-latitudes of Mars and form parallel to dendritic networks. These features record a significant warming of the regional/global climate which may have been associated with outflow channel formation and/or a period of alluvial fan deposition in Margaritifer Terra [1]. HAVs are distinct from older valley networks in both their age and morphology and they provide a window into the past climate conditions and potential water sources which formed them. Using quantitative geomorphic analysis we calculate the expected range of timescales, water volumes, precipitation rates and atmospheric conditions which contributed to HAV formation. In Newton crater (40oS, -159oE) we measured valley widths, depths, slopes and alluvial fan volumes. These observations, when combined with a set of terrestrial sediment transport prediction functions [2,3,4,5], allow us to calculate an expected duration of fluvial activity ranging from 0.1 to 10 years for water-filled channel depths ranging between 20 and 130 cm, and median sediment grain size ranging from 1 mm to 10 cm. The water volume required to form a single HAV in Newton crater ranges between 1.8 and 5.7~km3 based on the Darcy-Weisbach equation [6] in combination with the aforementioned range in channel depths, grain sizes and formation timescales. These results imply water runoff rates of between 1 to 10~cm/day over a typical, 300~km2, drainage area. Such a high runoff rate and short formation time suggest a brief, dramatic regional to global climate excursion. The source of water which formed these features remains unclear, but it must have been released at the aforementioned rates, and was widely distributed within each drainage catchment, and regionally over Newton crater and the southern highlands. HAV formation was likely a two-step process involving, first, the deposition of a 10s of meters thick regional snowpack along

Comparing Livestock Enterprises for the Optimum Combination of Labor and Capital Resources to Produce Maximum Income. Final Report.

ERIC Educational Resources Information Center

Ratcliff, Dale L.

Designed as a tool for vocational agriculture instructors to use in helping their students plan livestock enterprises that they will use as a part of their supervised occupational experience programs, this microcomputer program enables students to compare livestock enterprises for optimum combination of labor and capital resources to produce…

Optimum reduction of the dynamo threshold by a ferromagnetic layer located in the flow.

PubMed

Herault, J; Pétrélis, F

2014-09-01

We consider a fluid dynamo model generated by the flow on both sides of a moving layer. The magnetic permeability of the layer is larger than that of the flow. We show that there exists an optimum value of magnetic permeability for which the critical magnetic Reynolds number for dynamo onset is smaller than for a nonmagnetic material and also smaller than for a layer of infinite magnetic permeability. We present a mechanism that provides an explanation for recent experimental results. A similar effect occurs when the electrical conductivity of the layer is large.

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.

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).

Light cone effect on the reionization 21-cm signal - II. Evolution, anisotropies and observational implications

NASA Astrophysics Data System (ADS)

Datta, Kanan K.; Jensen, Hannes; Majumdar, Suman; Mellema, Garrelt; Iliev, Ilian T.; Mao, Yi; Shapiro, Paul R.; Ahn, Kyungjin

2014-08-01

Measurements of the H I 21-cm power spectra from the reionization epoch will be influenced by the evolution of the signal along the line-of-sight direction of any observed volume. We use numerical as well as seminumerical simulations of reionization in a cubic volume of 607 Mpc across to study this so-called light-cone effect on the H I 21-cm power spectrum. We find that the light-cone effect has the largest impact at two different stages of reionization: one when reionization is ˜20 per cent and other when it is ˜80 per cent completed. We find a factor of ˜4 amplification of the power spectrum at the largest scale available in our simulations. We do not find any significant anisotropy in the 21-cm power spectrum due to the light-cone effect. We argue that for the power spectrum to become anisotropic, the light-cone effect would have to make the ionized bubbles significantly elongated or compressed along the line of sight, which would require extreme reionization scenarios. We also calculate the two-point correlation functions parallel and perpendicular to the line of sight and find them to differ. Finally, we calculate an optimum frequency bandwidth below which the light-cone effect can be neglected when extracting power spectra from observations. We find that if one is willing to accept a 10 per cent error due to the light-cone effect, the optimum frequency bandwidth for k = 0.056 Mpc-1 is ˜7.5 MHz. For k = 0.15 and 0.41 Mpc-1, the optimum bandwidth is ˜11 and ˜16 MHz, respectively.

Evaluation of Energy Dose and Output Power Optimum of Diode’s Laser of 450 nm and 650 nm in Photoantimicrobial Mechanisms Against Inhibition of C. Albicans Biofilm Cells

NASA Astrophysics Data System (ADS)

Dewi-Astuty, S.; Suhariningsih; Dyah-Astuti, S.; Baktir, A.

2018-03-01

Photoantimicrobial as a pathogenic microbial inhibitory therapy system such as C. albicans in biofilms forms has been studied in vitro. Mechanisms of inhibiting called inactivating used the absorb principles of a dye agents such as chlorophyll against the photon energy of diode laser which any number of ROS product depend on energy doses of a laser, time of irradiation, concentration and time of incubation the dyes agent. The inactivation profile of C. albicans biofilm cells was observed based on cell viability reduction after photoantimicrobial treatment with or without oxygenation by XTT assay test. Results show that the inhibiting significantly with the time incubation of the dye agents and the oxygen degree inside the sample. The inhibition for oxygenation biofilm’s group 10% lower than without oxygenation biofilm’s group at the maximum of reduction of cell viability occurred in the 3hour incubation group. Optimum of inactivation are 89.6% (without oxygenation) and 94.8% (with oxygenation) after irradiation with 450 nm laser (power output 128.73 at energy dose 86.09 J/cm2), While, by 650 nm laser (power output 164.53 mW at energy dose 92.52 J/cm2) irradiation treatment obtained optimum of inactivation are 89.5% (without oxygenation) and 92.3% (with oxygenation).

Design of optimum solid oxide membrane electrolysis cells for metals production

DOE PAGES

Guan, Xiaofei; Pal, Uday B.

2015-12-24

Oxide to metal conversion is one of the most energy-intensive steps in the value chain for metals production. Solid oxide membrane (SOM) electrolysis process provides a general route for directly reducing various metal oxides to their respective metals, alloys, or intermetallics. Because of its lower energy use and ability to use inert anode resulting in zero carbon emission, SOM electrolysis process emerges as a promising technology that can replace the state-of-the-art metals production processes. In this paper, a careful study of the SOM electrolysis process using equivalent DC circuit modeling is performed and correlated to the experimental results. Finally, amore » discussion on relative importance of each resistive element in the circuit and on possible ways of lowering the rate-limiting resistive elements provides a generic guideline for designing optimum SOM electrolysis cells.« less

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.

Optimum tuned mass damper design using harmony search with comparison of classical methods

NASA Astrophysics Data System (ADS)

Nigdeli, Sinan Melih; Bekdaş, Gebrail; Sayin, Baris

2017-07-01

As known, tuned mass dampers (TMDs) are added to mechanical systems in order to obtain a good vibration damping. The main aim is to reduce the maximum amplitude at the resonance state. In this study, a metaheuristic algorithm called harmony search employed for the optimum design of TMDs. As the optimization objective, the transfer function of the acceleration of the system with respect to ground acceleration was minimized. The numerical trails were conducted for 4 single degree of freedom systems and the results were compared with classical methods. As a conclusion, the proposed method is feasible and more effective than the other documented methods.

Finding optimum airfoil shape to get maximum aerodynamic efficiency for a wind turbine

NASA Astrophysics Data System (ADS)

Sogukpinar, Haci; Bozkurt, Ismail

2017-02-01

In this study, aerodynamic performances of S-series wind turbine airfoil of S 825 are investigated to find optimum angle of attack. Aerodynamic performances calculations are carried out by utilization of a Computational Fluid Dynamics (CFD) method withstand finite capacity approximation by using Reynolds-Averaged-Navier Stokes (RANS) theorem. The lift and pressure coefficients, lift to drag ratio of airfoil S 825 are analyzed with SST turbulence model then obtained results crosscheck with wind tunnel data to verify the precision of computational Fluid Dynamics (CFD) approximation. The comparison indicates that SST turbulence model used in this study can predict aerodynamics properties of wind blade.

High-throughput method for optimum solubility screening for homogeneity and crystallization of proteins

DOEpatents

Kim, Sung-Hou [Moraga, CA; Kim, Rosalind [Moraga, CA; Jancarik, Jamila [Walnut Creek, CA

2012-01-31

An optimum solubility screen in which a panel of buffers and many additives are provided in order to obtain the most homogeneous and monodisperse protein condition for protein crystallization. The present methods are useful for proteins that aggregate and cannot be concentrated prior to setting up crystallization screens. A high-throughput method using the hanging-drop method and vapor diffusion equilibrium and a panel of twenty-four buffers is further provided. Using the present methods, 14 poorly behaving proteins have been screened, resulting in 11 of the proteins having highly improved dynamic light scattering results allowing concentration of the proteins, and 9 were crystallized.

Estimating regression coefficients from clustered samples: Sampling errors and optimum sample allocation

NASA Technical Reports Server (NTRS)

Kalton, G.

1983-01-01

A number of surveys were conducted to study the relationship between the level of aircraft or traffic noise exposure experienced by people living in a particular area and their annoyance with it. These surveys generally employ a clustered sample design which affects the precision of the survey estimates. Regression analysis of annoyance on noise measures and other variables is often an important component of the survey analysis. Formulae are presented for estimating the standard errors of regression coefficients and ratio of regression coefficients that are applicable with a two- or three-stage clustered sample design. Using a simple cost function, they also determine the optimum allocation of the sample across the stages of the sample design for the estimation of a regression coefficient.

New approach for determination of an optimum honeybee colony's carrying capacity based on productivity and nectar secretion potential of bee forage species.

PubMed

Al-Ghamdi, Ahmed; Adgaba, Nuru; Getachew, Awraris; Tadesse, Yilma

2016-01-01

The present study was carried out to determine an optimum honeybee colony's carrying capacity of selected valleys dominated by Ziziphus spina-christi and Acacia tortilis in the Al-Baha region, Kingdom of Saudi Arabia. The study was conducted based on the assessment of the number of colonies kept, their productivities and the existing productive bee forage resources in the target valleys with its economic implication. In the existing beekeeping practice, the average number of managed honeybee colonies introduced per square kilometer was 530 and 317 during the flowering period of Z. spina-christi and A. tortilis, respectively. Furthermore, the overall ratios of productive bee forage plants to the number of honeybee colonies introduced were 0.55 and 11.12 to Ziziphus trees and A. tortilis shrubs respectively. In the existing situation the average honey production potential of 5.21 and 0.34 kg was recorded per Ziziphus and A. tortilis plants per flowering season, respectively. The present study, revealed that the number of honeybee colonies introduced in relation to the existing bee forage potential was extremely overcrowding which is beyond the carrying capacity of bee forage resources in selected valleys and it has been observed to affect the productivities and subsequent profitability of beekeeping. The study infers that, by keeping the optimum honeybee colony's carrying capacity of valleys (88 traditional hives/km(2) or 54 Langstroth hives/km(2) in Ziziphus field and 72 traditional hives/km(2) or 44 Langstroth hives/km(2) in A. tortilis field), profitability of beekeeping can be boosted up to 130.39% and 207.98% during Z. spina-christi and A. tortilis, flowering seasons, respectively.

Optical modeling of a corneal inlay in real eyes to increase depth of focus: optimum centration and residual defocus.

PubMed

Tabernero, Juan; Artal, Pablo

2012-02-01

To determine the optimum position to center a small-aperture corneal inlay and the effect of residual defocus in the surgical eye to maximize depth of focus. Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain. Cohort study. Personalized eye models were built using actual data (corneal topography, eye length, ocular aberrations, and eye alignment). A small aperture 1.6 mm in diameter was placed at the corneal plane in each model. The monochromatic and polychromatic Strehl ratios were calculated as a function of the pinhole position. Different residual defocus values were also incorporated into the models, and the through-focus Strehl ratios were calculated. Sixteen eye models were built. For most subjects, the optimum location of the aperture for distance vision was close to the corneal reflex position. For a given optimized centration of the aperture, the best compromise of depth of focus was obtained when the eyes had some residual myopic defocus (range -0.75 to -1.00 diopter [D]). Strehl ratio values were over 0.1 for far distance, which led to visual acuities better than 20/20. The depth of focus was 2.50 D with a mean near visual acuity of Jaeger 1 or better. In eyes with little astigmatism and aberrations, the optimum centration of the small aperture was near the corneal reflex position. To improve optical outcomes with the inlay, some small residual myopia and correction of corneal astigmatism might be required. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Application of numerical simulation on optimum design of two-dimensional sedimentation tanks in the wastewater treatment plant.

PubMed

Zeng, Guang-Ming; Zhang, Shuo-Fu; Qin, Xiao-Sheng; Huang, Guo-He; Li, Jian-Bing

2003-05-01

The paper establishes the relationship between the settling efficiency and the sizes of the sedimentation tank through the process of numerical simulation, which is taken as one of the constraints to set up a simple optimum designing model of sedimentation tank. The feasibility and advantages of this model based on numerical calculation are verified through the application of practical case.

A method for optimum PSA setting in the absence of a pure α or β emitter and its application in the determination of (237)Np/(233)Pa.

PubMed

Feng, Xiao-gui; He, Qian-ge; Wang, Jian-chen; Chen, Jing

2014-11-01

In the application of liquid scintillation counting (LSC), the α/β discrimination is carried out with the function of pulse shape analysis (PSA), which requires the setting of the optimum PSA level. The optimum PSA are usually determined by the generation of cross-over plots, whereby a pair of vials, one containing a pure α emitter and the other a pure β emitter, is counted. However, in some cases such as the determination of (237)Np/(233)Pa, a pure α emitter or a pure β emitter is not available. Therefore, we have developed a new approach to set the optimum PSA by measuring the sample itself of mixed α/β emitters. The count rate of the sample in the α-multi-channel analyzer changes monotonically with the increase of the PSA, and there is always an inflection point which is related to the optimum PSA. By fitting the data near the inflection point with the function y=ax(3)+bx(2)+cx+d, we can obtain the optimum PSA as -b/(3a), which can be used to determine the radioactivity of (237)Np/(233)Pa. The results obtained with this new approach were in good agreement with those obtained by HPGe γ spectrometry that was calibrated with an LSC sample of (237)Np/(233)Pa under a radioactive secular equilibrium. The new approach is promising to be used in simultaneous determination of gross α and β emitters, especially in the absence of a pure α or β emitter. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ventilation/perfusion single-photon emission computed tomography: a service evaluation.

PubMed

Parekh, Amit; Graham, Richard; Redman, Stewart

2017-08-01

To identify the positive rate and negative predictive value (NPV) of our ventilation/perfusion (V/Q) single-photon emission computed tomography (SPECT) service as respective markers of overcalling (false positives) and undercalling (false negatives). We also identified the indeterminate rate as an indicator of the technical quality of the scans and reporter confidence. V/Q SPECT studies carried out over 5 years were classified into positive, negative and indeterminate results. Patients who had died or had pulmonary emboli on imaging within 3 months of a negative V/Q SPECT were identified as false negatives, from which the NPV was calculated. The total number of positive and indeterminate studies as a proportion of all studies was calculated as the positive and indeterminate rates. The positive rate, NPV and indeterminate rates in nonpregnant patients were 24, 98.7-100 and 3.6%, respectively. The positive rate, NPV and indeterminate rates in pregnant patients were 6.8, 100 and 2.3%, respectively. The positive rate and NPV for nonpregnant patients were similar to the published literature. This suggests that we provide a safe service. The indeterminate rate was slightly higher than the stated guidelines. The study shows that the positive rate and NPV are achievable indicators of potential overcalling and undercalling in a V/Q SPECT service.This is also one of the first studies to report a positive rate in pregnant patients undergoing V/Q SPECT that other institutions can use as a standard when evaluating their services.

Statistical Power and Optimum Sample Allocation Ratio for Treatment and Control Having Unequal Costs Per Unit of Randomization

ERIC Educational Resources Information Center

Liu, Xiaofeng

2003-01-01

This article considers optimal sample allocation between the treatment and control condition in multilevel designs when the costs per sampling unit vary due to treatment assignment. Optimal unequal allocation may reduce the cost from that of a balanced design without sacrificing any power. The optimum sample allocation ratio depends only on the…

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.

A near-optimum procedure for selecting stations in a streamgaging network

USGS Publications Warehouse

Lanfear, Kenneth J.

2005-01-01

Two questions are fundamental to Federal government goals for a network of streamgages which are operated by the U.S. Geological Survey: (1) how well does the present network of streamagaging stations meet defined Federal goals and (2) what is the optimum set of stations to add or reactivate to support remaining goals? The solution involves an incremental-stepping procedure that is based on Basic Feasible Incremental Solutions (BFIS?s) where each BFIS satisfies at least one Federal streamgaging goal. A set of minimum Federal goals for streamgaging is defined to include water measurements for legal compacts and decrees, flooding, water budgets, regionalization of streamflow characteristics, and water quality. Fully satisfying all these goals by using the assumptions outlined in this paper would require adding 887 new streamgaging stations to the U.S. Geological Survey network and reactivating an additional 857 stations that are currently inactive.

Equivalent circuit and optimum design of a multilayer laminated piezoelectric transformer.

PubMed

Dong, Shuxiang; Carazo, Alfredo Vazquez; Park, Seung Ho

2011-12-01

A multilayer laminated piezoelectric Pb(Zr(1-x)Ti(x))O(3) (PZT) ceramic transformer, operating in a half- wavelength longitudinal resonant mode (λ/2 mode), has been analyzed. This piezoelectric transformer is composed of one thickness-polarized section (T-section) for exciting the longitudinal mechanical vibrations, two longitudinally polarized sections (L-section) for generating high-voltage output, and two insulating layers laminated between the T-section and L-section layers to provide insulation between the input and output sections. Based on the piezoelectric constitutive and motion equations, an electro-elasto-electric (EEE) equivalent circuit has been developed, and correspondingly, an effective EEE coupling coefficient was proposed for optimum design of this multilayer transformer. Commercial finite element analysis software is used to determine the validity of the developed equivalent circuit. Finally, a prototype sample was manufactured and experimental data was collected to verify the model's validity.

An approach to the analysis of performance of quasi-optimum digital phase-locked loops.

NASA Technical Reports Server (NTRS)

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

1973-01-01

An approach to the analysis of performance of quasi-optimum digital phase-locked loops (DPLL's) is presented. An expression for the characteristic function of the prior error in the state estimate is derived, and from this expression an infinite dimensional equation for the prior error variance is obtained. The prior error-variance equation is a function of the communication system model and the DPLL gain and is independent of the method used to derive the DPLL gain. Two approximations are discussed for reducing the prior error-variance equation to finite dimension. The effectiveness of one approximation in analyzing DPLL performance is studied.

Optimum hot electron production with low-density foams for laser fusion by fast ignition.

PubMed

Lei, A L; Tanaka, K A; Kodama, R; Kumar, G R; Nagai, K; Norimatsu, T; Yabuuchi, T; Mima, K

2006-06-30

We propose a foam cone-in-shell target design aiming at optimum hot electron production for the fast ignition. A thin low-density foam is proposed to cover the inner tip of a gold cone inserted in a fuel shell. An intense laser is then focused on the foam to generate hot electrons for the fast ignition. Element experiments demonstrate increased laser energy coupling efficiency into hot electrons without increasing the electron temperature and beam divergence with foam coated targets in comparison with solid targets. This may enhance the laser energy deposition in the compressed fuel plasma.

An ergonomic study of the optimum operating table height for laparoscopic surgery.

PubMed

Berquer, R; Smith, W D; Davis, S

2002-03-01

Laparoscopic surgery requires the use of longer instruments than open surgery, thus changing the relation between the height of the surgeon's hands and the desirable height of the operating room table. The optimum height of the operating room table for laparoscopic surgery is investigated in this study. Twenty-one surgeons performed a two-handed, one-fourth circle cutting task using a laparoscopic video system and laparoscopic instruments positioned at five instrument handle heights relative to subjects' elbow height (-20, -10, 0, +10, and +20 cm) by adjusting the height of the trainer box. Subjects rated the difficulty and discomfort experienced during each task on a visual analog scale. Skin conductance (SC) was measured in Micromhos via paired surface electrodes placed near the ulnar edge of the palm of the right (cutting) hand. The mean electromyographic (EMG) signal from the right deltoid and trapezius muscles was measured. Arm orientation was measured in three dimensions using a magnetometer/accelerometer. Signals were acquired using analog circuitry and digitally sampled using a National Instruments DAQCard 700 connected to a Macintosh PowerBook 5300c running LabVIEW software. Statistical analysis was carried out by analysis of variance and post hoc testing. Statistically significant changes were found in the subjective rating of discomfort (p <0.002), deltoid EMG (p <0.0006), trapezius EMG (p <0.0001), and arm elevation (p <0.0001) between instrument handle heights. SC values and task times did not change significantly. Discomfort and difficulty ratings were lowest when instrument handles were positioned at elbow height. EMG values and arm elevation all decreased with lower instrument height. This study suggests that the optimum table height for laparoscopic surgery should position the laparoscopic instrument handles close to surgeons' elbow level to minimize discomfort and upper arm and shoulder muscle work. This corresponds to an approximate table height

Investigation of an Optimum Detection Scheme for a Star-Field Mapping System

NASA Technical Reports Server (NTRS)

Aldridge, M. D.; Credeur, L.

1970-01-01

An investigation was made to determine the optimum detection scheme for a star-field mapping system that uses coded detection resulting from starlight shining through specially arranged multiple slits of a reticle. The computer solution of equations derived from a theoretical model showed that the greatest probability of detection for a given star and background intensity occurred with the use of a single transparent slit. However, use of multiple slits improved the system's ability to reject the detection of undesirable lower intensity stars, but only by decreasing the probability of detection for lower intensity stars to be mapped. Also, it was found that the coding arrangement affected the root-mean-square star-position error and that detection is possible with error in the system's detected spin rate, though at a reduced probability.

A study on the optimum fast neutron flux for boron neutron capture therapy of deep-seated tumors.

PubMed

Rasouli, Fatemeh S; Masoudi, S Farhad

2015-02-01

High-energy neutrons, named fast neutrons which have a number of undesirable biological effects on tissue, are a challenging problem in beam designing for Boron Neutron Capture Therapy, BNCT. In spite of this fact, there is not a widely accepted criterion to guide the beam designer to determine the appropriate contribution of fast neutrons in the spectrum. Although a number of researchers have proposed a target value for the ratio of fast neutron flux to epithermal neutron flux, it can be shown that this criterion may not provide the optimum treatment condition. This simulation study deals with the determination of the optimum contribution of fast neutron flux in the beam for BNCT of deep-seated tumors. Since the dose due to these high-energy neutrons damages shallow tissues, delivered dose to skin is considered as a measure for determining the acceptability of the designed beam. To serve this purpose, various beam shaping assemblies that result in different contribution of fast neutron flux are designed. The performances of the neutron beams corresponding to such configurations are assessed in a simulated head phantom. It is shown that the previously used criterion, which suggests a limit value for the contribution of fast neutrons in beam, does not necessarily provide the optimum condition. Accordingly, it is important to specify other complementary limits considering the energy of fast neutrons. By analyzing various neutron spectra, two limits on fast neutron flux are proposed and their validity is investigated. The results show that considering these limits together with the widely accepted IAEA criteria makes it possible to have a more realistic assessment of sufficiency of the designed beam. Satisfying these criteria not only leads to reduction of delivered dose to skin, but also increases the advantage depth in tissue and delivered dose to tumor during the treatment time. The Monte Carlo Code, MCNP-X, is used to perform these simulations. Copyright © 2014

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.

OPDOT: A computer program for the optimum preliminary design of a transport airplane

NASA Technical Reports Server (NTRS)

Sliwa, S. M.; Arbuckle, P. D.

1980-01-01

A description of a computer program, OPDOT, for the optimal preliminary design of transport aircraft is given. OPDOT utilizes constrained parameter optimization to minimize a performance index (e.g., direct operating cost per block hour) while satisfying operating constraints. The approach in OPDOT uses geometric descriptors as independent design variables. The independent design variables are systematically iterated to find the optimum design. The technical development of the program is provided and a program listing with sample input and output are utilized to illustrate its use in preliminary design. It is not meant to be a user's guide, but rather a description of a useful design tool developed for studying the application of new technologies to transport airplanes.

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 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

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.

Emittance measurements for optimum operation of the J-PARC RF-driven H{sup −} ion source

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

Ueno, A., E-mail: akira.ueno@j-parc.jp; Ohkoshi, K.; Ikegami, K.

2015-04-08

In order to satisfy the Japan Proton Accelerator Research Complex (J-PARC) second stage requirements of an H{sup −} ion beam of 60mA within normalized emittances of 1.5πmm•mrad both horizontally and vertically, a flat top beam duty factor of 1.25% (500μs×25Hz) and a life-time of longer than 1month, the J-PARC cesiated RF-driven H{sup −} ion source was developed by using an internal-antenna developed at the Spallation Neutron Source (SNS). The transverse emittances of the source were measured with various conditions to find out the optimum operation conditions minimizing the horizontal and vertical rms normalized emittances. The transverse emittances were most effectivelymore » reduced by operating the source with the plasma electrode temperature lower than 70°C. The optimum value of the cesium (Cs) density around the beam hole of the plasma electrode seems to be proportional to the plasma electrode temperature. The fine control of the Cs density is indispensable, since the emittances seem to increase proportionally to the excessiveness of the Cs density. Furthermore, the source should be operated with the Cs density beyond a threshold value, since the plasma meniscus shape and the ellipse parameters of the transverse emittances seem to be changed step-function-likely on the threshold Cs value.« less

Production and characterization of cowpea protein hydrolysate with optimum nitrogen solubility by enzymatic hydrolysis using pepsin.

PubMed

Mune Mune, Martin Alain; Minka, Samuel René

2017-06-01

Cowpea is a source of low-cost and good nutritional quality protein for utilization in food formulations in replacement of animal proteins. Therefore it is necessary that cowpea protein exhibits good functionality, particularly protein solubility which affects the other functional properties. The objective of this study was to produce cowpea protein hydrolysate exhibiting optimum solubility by the adequate combination of hydrolysis parameters, namely time, solid/liquid ratio (SLR) and enzyme/substrate ratio (ESR), and to determine its functional properties and molecular characteristics. A Box-Behnken experimental design was used for the experiments, and a second-order polynomial to model the effects of hydrolysis time, SLR and ESR on the degree of hydrolysis and nitrogen solubility index. The optimum hydrolysis conditions of time 208.61 min, SLR 1/15 (w/w) and ESR 2.25% (w/w) yielded a nitrogen solubility of 75.71%. Protein breakdown and the peptide profile following enzymatic hydrolysis were evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and size exclusion chromatography. Cowpea protein hydrolysate showed higher oil absorption capacity, emulsifying activity and foaming ability compared with the concentrate. The solubility of cowpea protein hydrolysate was adequately optimized by response surface methodology, and the hydrolysate showed adequate functionality for use in food. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

A method searching for optimum fractional order and its application in self-phase modulation induced nonlinear phase noise estimation in coherent optical fiber transmission systems

NASA Astrophysics Data System (ADS)

Huang, Chuan; Guo, Peng; Yang, Aiying; Qiao, Yaojun

2018-07-01

In single channel systems, the nonlinear phase noise only comes from the channel itself through self-phase modulation (SPM). In this paper, a fast-nonlinear effect estimation method is proposed based on fractional Fourier transformation (FrFT). The nonlinear phase noise caused by Self-phase modulation effect is accurately estimated for single model 10Gbaud OOK and RZ-QPSK signals with the fiber length range of 0-200 km and the launch power range of 1-10 mW. The pulse windowing is adopted to search the optimum fractional order for the OOK and RZ-QPSK signals. Since the nonlinear phase shift caused by the SPM effect is very small, the accurate optimum fractional order of the signal cannot be found based on the traditional method. In this paper, a new method magnifying the phase shift is proposed to get the accurate optimum order and thus the nonlinear phase shift is calculated. The simulation results agree with the theoretical analysis and the method is applicable to signals whose pulse type has the similar characteristics with Gaussian pulse.

Optimum design of a Lanchester damper for a viscously damped single degree of freedom system subjected to inertial excitation

NASA Astrophysics Data System (ADS)

Bapat, V. A.; Prabhu, P.

1980-11-01

The problem of designing an optimum Lanchester damper for a viscously damped single degree of freedom system subjected to inertial harmonic excitation is investigated. Two criteria are used for optimizing the performance of the damper: (i) minimum motion transmissibility; (ii) minimum force transmissibility. Explicit expressions are developed for determining the absorber parameters.

Molecular-Directed Treatment of Differentiated Thyroid Cancer: Advances in Diagnosis and Treatment.

PubMed

Yip, Linwah; Sosa, Julie Ann

2016-07-01

Thyroid cancer incidence is increasing, and when fine-needle aspiration biopsy results are cytologically indeterminate, the diagnosis is often still established only after thyroidectomy. Molecular marker testing may be helpful in guiding patient-oriented and tailored management of thyroid nodules and thyroid cancer. To summarize available data on the use of molecular testing to improve the diagnosis and prognostication of thyroid cancer. A MEDLINE review was conducted using the primary search terms molecular, thyroid cancer, thyroid nodule, and gene expression classifier in search strings. Articles were restricted to those published between January 1, 2010, and June 1, 2015, inclusive of adult humans, and reported in the English language only. Of 867 titles screened, 67 articles were further identified for review of the full text. The 2 most studied molecular marker testing techniques for indeterminate thyroid nodules include gene expression classifier analysis and evaluation for somatic mutations or rearrangements that are commonly found in thyroid cancer (7-gene panel). Nodules with benign results on gene expression classifier analysis can be associated with less than a 5% risk of cancer and may be observed, while nodules with positive results on the 7-gene panel may have a higher risk of cancer (80%-100%) and definitive surgery can be recommended. However, cancer prevalence and geographic variations in histologic subtypes may affect accuracy and clinical applicability of both tests. Molecular marker tests such as ThyroSeq version 2.1 are more comprehensive, but they need further validation. Preoperative risk stratification using molecular markers also may be used to better define the optimal extent of thyroidectomy for patients with thyroid cancer. Molecular markers potentially can augment the diagnostic specificity of fine-needle aspiration biopsy to better differentiate cytologically indeterminate nodules that can be safely observed from cytologically

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

Optimum satellite orbits for accurate measurement of the earth's radiation budget, summary

NASA Technical Reports Server (NTRS)

Campbell, G. G.; Vonderhaar, T. H.

1978-01-01

The optimum set of orbit inclinations for the measurement of the earth radiation budget from spacially integrating sensor systems was estimated for two and three satellite systems. The best set of the two were satellites at orbit inclinations of 80 deg and 50 deg; of three the inclinations were 80 deg, 60 deg and 50 deg. These were chosen on the basis of a simulation of flat plate and spherical detectors flying over a daily varying earth radiation field as measured by the Nimbus 3 medium resolution scanners. A diurnal oscillation was also included in the emitted flux and albedo to give a source field as realistic as possible. Twenty three satellites with different inclinations and equator crossings were simulated, allowing the results of thousand of multisatellite sets to be intercompared. All were circular orbits of radius 7178 kilometers.

Realizable feed-element patterns and optimum aperture efficiency in multibeam antenna systems

NASA Technical Reports Server (NTRS)

Yngvesson, K. S.; Rahmat-Samii, Y.; Johansson, J. F.; Kim, Y. S.

1988-01-01

The results of an earlier paper by Rahmat-Samii et al. (1981), regarding realizable patterns from feed elements that are part of an array that feeds a reflector antenna, are extended. The earlier paper used a cos exp q theta model for the element radiation pattern, whereas here a parametric study is performed, using a model that assumes a central beam of cos exp q theta shape, with a constant sidelobe level outside the central beam. Realizable q-values are constrained by the maximum directivity based on feed element area. The optimum aperture efficiency (excluding array feed network losses) in an array-reflector system is evaluated as a function of element spacing using this model as well as the model of the earlier paper. Experimental data for tapered slot antenna (TSA) arrays are in agreement with the conclusions based on the model.

Preliminary study of optimum ductburning turbofan engine cycle design parameters for supersonic cruising

NASA Technical Reports Server (NTRS)

Fishbach, L. H.

1978-01-01

The effect of turbofan engine overall pressure ratio, fan pressure ratio, and ductburner temperature rise on the engine weight and cruise fuel consumption for a mach 2.4 supersonic transport was investigated. Design point engines, optimized purely for the supersonic cruising portion of the flight where the bulk of the fuel is consumed, are considered. Based on constant thrust requirements at cruise, fuel consumption considerations would favor medium by pass ratio engines (1.5 to 1.8) of overall pressure ratio of about 16. Engine weight considerations favor low bypass ratio (0.6 or less) and low wverall pressure ratio (8). Combination of both effects results in bypass ratios of 0.6 to 0.8 and overall pressure ratio of 12 being the overall optimum.

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.

Optimum cooking conditions for shrimp and Atlantic salmon.

PubMed

Brookmire, Lauren; Mallikarjunan, P; Jahncke, M; Grisso, R

2013-02-01

The quality and safety of a cooked food product depends on many variables, including the cooking method and time-temperature combinations employed. The overall heating profile of the food can be useful in predicting the quality changes and microbial inactivation occurring during cooking. Mathematical modeling can be used to attain the complex heating profile of a food product during cooking. Studies were performed to monitor the product heating profile during the baking and boiling of shrimp and the baking and pan-frying of salmon. Product color, texture, moisture content, mass loss, and pressed juice were evaluated during the cooking processes as the products reached the internal temperature recommended by the FDA. Studies were also performed on the inactivation of Salmonella cocktails in shrimp and salmon. To effectively predict inactivation during cooking, the Bigelow, Fermi distribution, and Weibull distribution models were applied to the Salmonella thermal inactivation data. Minimum cooking temperatures necessary to destroy Salmonella in shrimp and salmon were determined. The heating profiles of the 2 products were modeled using the finite difference method. Temperature data directly from the modeled heating profiles were then used in the kinetic modeling of quality change and Salmonella inactivation during cooking. The optimum cooking times for a 3-log reduction of Salmonella and maintaining 95% of quality attributes are 100, 233, 159, 378, 1132, and 399 s for boiling extra jumbo shrimp, baking extra jumbo shrimp, boiling colossal shrimp, baking colossal shrimp, baking Atlantic salmon, and pan frying Atlantic Salmon, respectively. © 2013 Institute of Food Technologists®

Method for optimizing channelized quadratic observers for binary classification of large-dimensional image datasets

PubMed Central

Kupinski, M. K.; Clarkson, E.

2015-01-01

We present a new method for computing optimized channels for channelized quadratic observers (CQO) that is feasible for high-dimensional image data. The method for calculating channels is applicable in general and optimal for Gaussian distributed image data. Gradient-based algorithms for determining the channels are presented for five different information-based figures of merit (FOMs). Analytic solutions for the optimum channels for each of the five FOMs are derived for the case of equal mean data for both classes. The optimum channels for three of the FOMs under the equal mean condition are shown to be the same. This result is critical since some of the FOMs are much easier to compute. Implementing the CQO requires a set of channels and the first- and second-order statistics of channelized image data from both classes. The dimensionality reduction from M measurements to L channels is a critical advantage of CQO since estimating image statistics from channelized data requires smaller sample sizes and inverting a smaller covariance matrix is easier. In a simulation study we compare the performance of ideal and Hotelling observers to CQO. The optimal CQO channels are calculated using both eigenanalysis and a new gradient-based algorithm for maximizing Jeffrey's divergence (J). Optimal channel selection without eigenanalysis makes the J-CQO on large-dimensional image data feasible. PMID:26366764

Optimum BET surface areas for activated carbon produced from textile sewage sludges and its application as dye removal.

PubMed

Kacan, Erdal

2016-01-15

The purpose of this experimental study is to determine optimum preparation conditions for activated carbons obtained from textile sewage sludge (TSS) for removal of dyes from aqueous solutions. The textile sewage sludge activated carbon (TSSAC) was prepared by chemical activation with potassium hydroxide using Response Surface Methodology (RSM). The most influential factor on each experimental design responses was identified via ANNOVA analysis. Based on the central composite design (CCD), quadratic model was developed to correlate the preparation variables for one response which is the Brunauer-Emmelt-Teller (BET) surface area. RSM based on a three-variable CCD was used to determine the effect of pyrolyzed temperature (400-700 °C), carbonization time (45-180 min) and KOH: weight of TSS (wt%) impregnation ratio (0.5:1-1.5:1) on BET surface area. According to the results, pyrolyzed temperature and impregnation ratio were found as the significant factors for maximizing the BET surface area. The major effect which influences the BET surface area was found as pyrolyzed temperature. Both carbonization time and impregnation ratio of KOH had no significant effect. The optimum conditions for preparing TSSAC, based on response surface and contour plots, were found as follows: pyrolyzed temperature 700 °C, carbonization time of 45 min and chemical impregnation ratio of 0.5. The maximum and optimum BET surface area of TSSAC were found as 336 m(2)/g and 310.62 m(2)/g, respectively. Synozol Blue reactive (RSB) and Setapers Yellow-Brown (P2RFL) industrial textile dyes adsorption capacities were investigated. As expected the TSSAC which has the biggest BET surface area (336 m(2)/g) adsorbed dye best. The maximum (RSB) and (P2RFL) uptake capacities were found as 8.5383 mg/g and 5.4 mg/g, respectively. The results of this study indicated the applicability of TSSAC for removing industrial dyes from aqueous solution. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

Optimum Material Composition for Minimizing the Stress Intensity Factor of Edge Crack in Thick-Walled FGM Circular Pipes Under Thermomechanical Loading

NASA Astrophysics Data System (ADS)

Sekine, Hideki; Yoshida, Kimiaki

This paper deals with the optimization problem of material composition for minimizing the stress intensity factor of radial edge crack in thick-walled functionally graded material (FGM) circular pipes under steady-state thermomechanical loading. Homogenizing the FGM circular pipes by simulating the inhomogeneity of thermal conductivity by a distribution of equivalent eigentemperature gradient and the inhomogeneity of Young's modulus and Poisson's ratio by a distribution of equivalent eigenstrain, we present an approximation method to obtain the stress intensity factor of radial edge crack in the FGM circular pipes. The optimum material composition for minimizing the stress intensity factor of radial edge crack is determined using a nonlinear mathematical programming method. Numerical results obtained for a thick-walled TiC/Al2O3 FGM circular pipe reveal that it is possible to decrease remarkably the stress intensity factor of radial edge crack by setting the optimum material composition profile.

New approach for determination of an optimum honeybee colony’s carrying capacity based on productivity and nectar secretion potential of bee forage species

PubMed Central

Al-Ghamdi, Ahmed; Adgaba, Nuru; Getachew, Awraris; Tadesse, Yilma

2014-01-01

The present study was carried out to determine an optimum honeybee colony’s carrying capacity of selected valleys dominated by Ziziphus spina-christi and Acacia tortilis in the Al-Baha region, Kingdom of Saudi Arabia. The study was conducted based on the assessment of the number of colonies kept, their productivities and the existing productive bee forage resources in the target valleys with its economic implication. In the existing beekeeping practice, the average number of managed honeybee colonies introduced per square kilometer was 530 and 317 during the flowering period of Z. spina-christi and A. tortilis, respectively. Furthermore, the overall ratios of productive bee forage plants to the number of honeybee colonies introduced were 0.55 and 11.12 to Ziziphus trees and A. tortilis shrubs respectively. In the existing situation the average honey production potential of 5.21 and 0.34 kg was recorded per Ziziphus and A. tortilis plants per flowering season, respectively. The present study, revealed that the number of honeybee colonies introduced in relation to the existing bee forage potential was extremely overcrowding which is beyond the carrying capacity of bee forage resources in selected valleys and it has been observed to affect the productivities and subsequent profitability of beekeeping. The study infers that, by keeping the optimum honeybee colony’s carrying capacity of valleys (88 traditional hives/km2 or 54 Langstroth hives/km2 in Ziziphus field and 72 traditional hives/km2 or 44 Langstroth hives/km2 in A. tortilis field), profitability of beekeeping can be boosted up to 130.39% and 207.98% during Z. spina-christi and A. tortilis, flowering seasons, respectively. PMID:26858544

Automatic computation for optimum height planning of apartment buildings to improve solar access

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

Seong, Yoon-Bok; Kim, Yong-Yee; Seok, Ho-Tae

2011-01-15

The objective of this study is to suggest a mathematical model and an optimal algorithm for determining the height of apartment buildings to satisfy the solar rights of survey buildings or survey housing units. The objective is also to develop an automatic computation model for the optimum height of apartment buildings and then to clarify the performance and expected effects. To accomplish the objective of this study, the following procedures were followed: (1) The necessity of the height planning of obstruction buildings to satisfy the solar rights of survey buildings or survey housing units is demonstrated by analyzing through amore » literature review the recent trend of disputes related to solar rights and to examining the social requirements in terms of solar rights. In addition, the necessity of the automatic computation system for height planning of apartment buildings is demonstrated and a suitable analysis method for this system is chosen by investigating the characteristics of analysis methods for solar rights assessment. (2) A case study on the process of height planning of apartment buildings will be briefly described and the problems occurring in this process will then be examined carefully. (3) To develop an automatic computation model for height planning of apartment buildings, geometrical elements forming apartment buildings are defined by analyzing the geometrical characteristics of apartment buildings. In addition, design factors and regulations required in height planning of apartment buildings are investigated. Based on this knowledge, the methodology and mathematical algorithm to adjust the height of apartment buildings by automatic computation are suggested and probable problems and the ways to resolve these problems are discussed. Finally, the methodology and algorithm for the optimization are suggested. (4) Based on the suggested methodology and mathematical algorithm, the automatic computation model for optimum height of apartment

An Analysis of the Observed Low-level Structure of Rapidly Intensifying and Mature Hurricane Earl (2010)

DTIC Science & Technology

2014-01-01

characteristics of the boundary layer The studies by Braun and Tao (2000) and Smith and Thomsen (2010) have elevated awareness of an important problem ...estimates also of forecast uncertainty which follow from the uncertainty in not knowing the optimum boundary-layer scheme to use. In an effort to address this...Quarterly Journal of the Royal Meteorological Society Q. J. R. Meteorol. Soc. (2014) DOI:10.1002/qj.2283 An analysis of the observed low-level

75 FR 55823 - Notice of Inventory Completion: Denver Museum of Nature & Science, Denver, CO; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-14

...), A1985.3 (CUI 26), and A1985.4 (CUI 27)). The remains include one adult female, one child of indeterminate sex, and two adults of indeterminate sex. Most of these individuals are represented by fragmentary...

Optimum hexametaphosphate concentration to inhibit efflorescence formation in dry fermented sausages.

PubMed

Walz, Felix H; Gibis, Monika; Fritz, Maren; Herrmann, Kurt; Hinrichs, Jörg; Weiss, Jochen

2018-05-01

The occurrence of efflorescences on the surface of dry fermented sausages represents a current issue for the meat processing industry. Preventing the efflorescence formation by the addition of sodium hexametaphosphate (SHMP) was shown to be promising in a previous study. The optimum SHMP addition was studied by adding SHMP (0.0, 1.0, 3.0, and 5.0g/kg) directly to the sausage batter. Visual and chemical analyses were conducted during 8weeks of storage under modified atmosphere. Visual analyses revealed significant lower amounts of efflorescences on the sausage surface after 8weeks when 1.0 (27.1%), 3.0 (9.0%), and 5.0g/kg SHMP (3.4%) were added, compared to the control with 38.0% efflorescences. SHMP significantly affected the occurrence (8weeks) of magnesium on the surface: +85.5%, +23.7%, +3.5%, and -28.2% for 0.0, 1.0, 3.0, and 5.0g/kg, respectively. The addition of 4.785g/kg was calculated to fully inhibit the formation of efflorescences by complexing magnesium ions. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

Uranus occults SAO158687. [stellar occultation and planetary parametric observation

NASA Technical Reports Server (NTRS)

Elliot, J. L.; Veverka, J.; Millis, R. L.

1977-01-01

Experience gained in obtaining atmospheric parameters, oblatenesses, and diameters of Jupiter and Mars from recent stellar occultations by these planets is used to predict what can be learned from the March 1977 occultation of the star SAO158687 by Uranus. The spectra of this star and Uranus are compared to indicate the relative instrument intensities of the two objects, the four passbands where the relative intensities are most nearly equal are listed, and expected photon fluxes from the star are computed on the assumption that it has UBVRI colors appropriate for a K5 main-sequence object. It is shown that low photon noise errors can be achieved by choosing appropriate passbands for observation, and the rms error expected for the Uranus temperature profiles obtained from the occultation light curves is calculated. It is suggested that observers of this occultation should record their data digitally for optimum time resolution.

Chaotic genetic algorithm and Adaboost ensemble metamodeling approach for optimum resource planning in emergency departments.

PubMed

Yousefi, Milad; Yousefi, Moslem; Ferreira, Ricardo Poley Martins; Kim, Joong Hoon; Fogliatto, Flavio S

2018-01-01

Long length of stay and overcrowding in emergency departments (EDs) are two common problems in the healthcare industry. To decrease the average length of stay (ALOS) and tackle overcrowding, numerous resources, including the number of doctors, nurses and receptionists need to be adjusted, while a number of constraints are to be considered at the same time. In this study, an efficient method based on agent-based simulation, machine learning and the genetic algorithm (GA) is presented to determine optimum resource allocation in emergency departments. GA can effectively explore the entire domain of all 19 variables and identify the optimum resource allocation through evolution and mimicking the survival of the fittest concept. A chaotic mutation operator is used in this study to boost GA performance. A model of the system needs to be run several thousand times through the GA evolution process to evaluate each solution, hence the process is computationally expensive. To overcome this drawback, a robust metamodel is initially constructed based on an agent-based system simulation. The simulation exhibits ED performance with various resource allocations and trains the metamodel. The metamodel is created with an ensemble of the adaptive neuro-fuzzy inference system (ANFIS), feedforward neural network (FFNN) and recurrent neural network (RNN) using the adaptive boosting (AdaBoost) ensemble algorithm. The proposed GA-based optimization approach is tested in a public ED, and it is shown to decrease the ALOS in this ED case study by 14%. Additionally, the proposed metamodel shows a 26.6% improvement compared to the average results of ANFIS, FFNN and RNN in terms of mean absolute percentage error (MAPE). Copyright © 2017 Elsevier B.V. All rights reserved.

Factors that determine the optimum dose for sub-20nm resist systems: DUV, EUV, and e-beam options

NASA Astrophysics Data System (ADS)

Preil, Moshe

2012-03-01

As EUV and e-beam direct write (EBDW) technologies move closer to insertion into pilot production, questions regarding cost effectiveness take on increasing importance. One of the most critical questions is determining the optimum dose which balances the requirements for cost-effective throughput vs. imaging performance. To date most of the dose requirements have been dictated by the hardware side of the industry. The exposure tool manufacturers have a vested interest in specifying the fastest resists possible in order to maximize the throughput even if it comes at the expense of optimum resist performance. This is especially true for both EUV and EBDW where source power is severely limited. We will explore the cost-benefit tradeoffs which drive the equipment side of the industry, and show how these considerations lead to the current throughput and dose requirements for volume production tools. We will then show how the resulting low doses may lead to shot noise problems and a resulting penalty in resist performance. By comparison to the history of 248 nm DUV resist development we will illustrate how setting unrealistic initial targets for resist dose may lead to unacceptable tradeoffs in resist performance and subsequently long delays in the development of production worthy resists.

Evaluation of the effects of mulch on optimum sowing date and irrigation management of zero till wheat in central Punjab, India using APSIM.

PubMed

Balwinder-Singh; Humphreys, E; Gaydon, D S; Eberbach, P L

2016-10-01

Machinery for sowing wheat directly into rice residues has become more common in the rice-wheat systems of the north-west Indo-Gangetic Plains of South Asia, with increasing numbers of farmers now potentially able to access the benefits of residue retention. However, surface residue retention affects soil water and temperature dynamics, thus the optimum sowing date and irrigation management for a mulched crop may vary from those of a traditional non-mulched crop. Furthermore, the effects of sowing date and irrigation management are likely to vary with soil type and seasonal conditions. Therefore, a simulation study was conducted using the APSIM model and 40 years of weather data to evaluate the effects of mulch, sowing date and irrigation management and their interactions on wheat grain yield, irrigation requirement (I) and water productivity with respect to irrigation (WP I ) and evapotranspiration (WP ET ). The results suggest that the optimum wheat sowing date in central Punjab depends on both soil type and the presence or absence of mulch. On the sandy loam, with irrigation scheduled at 50% soil water deficit (SWD), the optimum sowing date was late October to early November for maximising yield, WP I and WP ET . On the clay loam, the optimum date was about one week later. The effect of mulch on yield varied with seasonal conditions and sowing date. With irrigation at 50% SWD, mulching of wheat sown at the optimum time increased average yield by up to 0.5 t ha -1 . The beneficial effect of mulch on yield increased to averages of 1.2-1.3 t ha -1 as sowing was advanced to 15 October. With irrigation at 50% SWD and 7 November sowing, mulch reduced the number of irrigations by one in almost 50% of years, a reduction of about 50 mm on the sandy loam and 60 mm on the clay loam. The reduction in irrigation amount was mainly due to reduced soil evaporation. Mulch reduced irrigation requirement by more as sowing was delayed, more so on the sandy loam than the clay

Predicting wettability behavior of fluorosilica coated metal surface using optimum neural network

NASA Astrophysics Data System (ADS)

Taghipour-Gorjikolaie, Mehran; Valipour Motlagh, Naser

2018-02-01

The interaction between variables, which are effective on the surface wettability, is very complex to predict the contact angles and sliding angles of liquid drops. In this paper, in order to solve this complexity, artificial neural network was used to develop reliable models for predicting the angles of liquid drops. Experimental data are divided into training data and testing data. By using training data and feed forward structure for the neural network and using particle swarm optimization for training the neural network based models, the optimum models were developed. The obtained results showed that regression index for the proposed models for the contact angles and sliding angles are 0.9874 and 0.9920, respectively. As it can be seen, these values are close to unit and it means the reliable performance of the models. Also, it can be inferred from the results that the proposed model have more reliable performance than multi-layer perceptron and radial basis function based models.

Optimum design of a novel pounding tuned mass damper under harmonic excitation

NASA Astrophysics Data System (ADS)

Wang, Wenxi; Hua, Xugang; Wang, Xiuyong; Chen, Zhengqing; Song, Gangbing

2017-05-01

In this paper, a novel pounding tuned mass damper (PTMD) utilizing pounding damping is proposed to reduce structural vibration by increasing the damping ratio of a lightly damped structure. The pounding boundary covered by viscoelastic material is fixed right next to the tuned mass when the spring-mass system is in the equilibrium position. The dynamic properties of the proposed PTMD, including the natural frequency and the equivalent damping ratio, are derived theoretically. Moreover, the numerical simulation method by using an impact force model to study the PTMD is proposed and validated by pounding experiments. To minimize the maximum dynamic magnification factor under harmonic excitations, an optimum design of the PTMD is developed. Finally, the optimal PTMD is implemented to control a lightly damped frame structure. A comparison of experimental and simulated results reveals that the proposed impact force model can accurately model the pounding force. Furthermore, the proposed PTMD is effective to control the vibration in a wide frequency range, as demonstrated experimentally.

Association of CMV-Specific T Cell-Mediated Immunity with CMV DNAemia and Development of CMV Disease in HIV-1–Infected Individuals

PubMed Central

Aichelburg, Maximilian C.; Weseslindtner, Lukas; Mandorfer, Mattias; Strassl, Robert; Rieger, Armin; Reiberger, Thomas; Puchhammer-Stöckl, Elisabeth; Grabmeier-Pfistershammer, Katharina

2015-01-01

Background Among HIV-1–infected individuals, cytomegalovirus (CMV) reactivation and disease occur in the setting of advanced immunosuppression. The value of a standardized assessment of CMV-specific T-cell mediated immunity by the CMV QuantiFERON assay (CMV-QFT) has not yet been thoroughly investigated in HIV-1–infected subjects. Methods Prospective, longitudinal study in 153 HIV-1–infected subjects with a CD4+ T cell count < 350/μL who simultaneously underwent CMV-QFT, CMV serology testing and CMV-DNA quantification. Factors associated with CMV-QFT were evaluated. Clinical screening for CMV manifestations was then performed every 3 months. Results Among the 141 CMV IgG-seropositive individuals the CMV-QFT assay yielded reactive results in 84% (118/141), negative results in 15% (21/141) and indeterminate (negative mitogen IFN-gamma response) results in 1% (2/141) of subjects. The mean actual CD4+ T cell count was significantly higher in CMV-QFT reactive subjects, when compared to CMV-QFT non-reactive individuals (183 ± 102 vs. 126 ± 104 cells/μL, P = 0.015). A significantly lower proportion of CMV-QFT reactive vs. non-reactive patients displayed CMV DNAemia > 100 copies/mL (23% (27/118) vs. 48% (11/23), P = 0.02). Furthermore, a statistically significant inverse association between mitogen IFN-gamma response and CMV-DNAemia > 1000 copies/mL was observed (P < 0.001). During the observational period, 5 CMV end-organ manifestations were observed. In three of the CMV cases the CMV-QFT yielded indeterminate results. Conclusions While CMV-QFT reactivity indicates CMV-specific immunity, indeterminate results due to negative mitogen IFN-gamma response might reflect HIV-1-induced immunodeficiency. Thus, dependency upon CD4+ T cell count should be considered when interpreting CMV-QFT results. PMID:26322514

Association of CMV-Specific T Cell-Mediated Immunity with CMV DNAemia and Development of CMV Disease in HIV-1-Infected Individuals.

PubMed

Aichelburg, Maximilian C; Weseslindtner, Lukas; Mandorfer, Mattias; Strassl, Robert; Rieger, Armin; Reiberger, Thomas; Puchhammer-Stöckl, Elisabeth; Grabmeier-Pfistershammer, Katharina

2015-01-01

Among HIV-1-infected individuals, cytomegalovirus (CMV) reactivation and disease occur in the setting of advanced immunosuppression. The value of a standardized assessment of CMV-specific T-cell mediated immunity by the CMV QuantiFERON assay (CMV-QFT) has not yet been thoroughly investigated in HIV-1-infected subjects. Prospective, longitudinal study in 153 HIV-1-infected subjects with a CD4+ T cell count < 350/μL who simultaneously underwent CMV-QFT, CMV serology testing and CMV-DNA quantification. Factors associated with CMV-QFT were evaluated. Clinical screening for CMV manifestations was then performed every 3 months. Among the 141 CMV IgG-seropositive individuals the CMV-QFT assay yielded reactive results in 84% (118/141), negative results in 15% (21/141) and indeterminate (negative mitogen IFN-gamma response) results in 1% (2/141) of subjects. The mean actual CD4+ T cell count was significantly higher in CMV-QFT reactive subjects, when compared to CMV-QFT non-reactive individuals (183 ± 102 vs. 126 ± 104 cells/μL, P = 0.015). A significantly lower proportion of CMV-QFT reactive vs. non-reactive patients displayed CMV DNAemia > 100 copies/mL (23% (27/118) vs. 48% (11/23), P = 0.02). Furthermore, a statistically significant inverse association between mitogen IFN-gamma response and CMV-DNAemia > 1000 copies/mL was observed (P < 0.001). During the observational period, 5 CMV end-organ manifestations were observed. In three of the CMV cases the CMV-QFT yielded indeterminate results. While CMV-QFT reactivity indicates CMV-specific immunity, indeterminate results due to negative mitogen IFN-gamma response might reflect HIV-1-induced immunodeficiency. Thus, dependency upon CD4+ T cell count should be considered when interpreting CMV-QFT results.

Interaction of temperature and an environmental stressor: Moina macrocopa responds with increased body size, increased lifespan, and increased offspring numbers slightly above its temperature optimum.

PubMed

Engert, Antonia; Chakrabarti, Shumon; Saul, Nadine; Bittner, Michal; Menzel, Ralph; Steinberg, Christian E W

2013-02-01

For organisms, temperature is one of the most important environmental factors and gains increasing importance due to global warming, since increasing temperatures may pose organisms close to their environmental tolerance limits and, thus, they may become more vulnerable to environmental stressors. We analyzed the temperature-dependence of the water-soluble antioxidant capacity of the cladoceran Moina macrocopa and evaluated its life trait variables with temperature (15, 20, 25, 30°C) and humic substance (HS) concentrations (0, 0.18, 0.36, 0.90, 1.79 mM DOC) as stressors. Temperatures below and above the apparent optimum (20°C) reduced the antioxidative capacity. Additions of HSs increased body length, but decreased mean lifespan at 15 and 20°C. There was no clear HS-effect on offspring numbers at 15, 20, and 30°C. At 25°C with increasing HS-concentration, lifespan was extended and offspring numbers increased tremendously, reaching 250% of the control. Although the applied HS preparation possesses estrogenic and antiandrogenic activities, a xenohormone mechanism does not seem plausible for the reproductive increase, because comparable effects did not occur at other temperatures. A more convincing explanation appears to be the mitohormesis hypothesis which states that a certain increase of reactive oxygen production leads to improved health and longevity and, with Moina, also to increased offspring numbers. Our results suggest that at least with the eurythermic M. macrocopa, a temperature above the optimum can be beneficial for several life trait variables, even when combined with a chemical stressor. Temperatures approximately 10°C above its optimum appear to adversely affect the lifespan and reproduction of M. macrocopa. This indicates that this cladoceran species seems to be able to utilize temperature as an ecological resource in a range slightly above its thermal optimum. Copyright © 2012 Elsevier Ltd. All rights reserved.

Injector Element which Maintains a Constant Mean Spray Angle and Optimum Pressure Drop During Throttling by Varying the Geometry of Tangential Inlets

NASA Technical Reports Server (NTRS)

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

2014-01-01

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 tangential inlet area for each throttleable stage is calculated. The correlation between the tangential inlet areas and delta pressure values is used to calculate the spring displacement and variable inlet geometry. An injector designed using the method includes a plurality of geometrically calculated tangential inlets in an injection tube; an injection tube cap with a plurality of inlet slots slidably engages the injection tube. A pressure differential across the injector element causes the cap to slide along the injection tube and variably align the inlet slots with the tangential inlets.

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.