Optimal methodology for distribution systems reconfiguration based on OPF and solved by decomposition technique

This paper presents a new and efficient methodology for distribution network reconfiguration integrated with optimal power flow (OPF) based on a Benders decomposition approach. The objective minimizes power losses, balancing load among feeders and subject to constraints: capacity limit of branches, minimum and maximum power limits of substations or distributed generators, minimum deviation of bus voltages and radial optimal operation of networks. The Generalized Benders decomposition algorithm is applied to solve the problem. The formulation can be embedded under two stages; the first one is the Master problem and is formulated as a mixed integer non-linear programming problem. This stage determines the radial topology of the distribution network. The second stage is the Slave problem and is formulated as a non-linear programming problem. This stage is used to determine the feasibility of the Master problem solution by means of an OPF and provides information to formulate the linear Benders cuts that connect both problems. The model is programmed in GAMS. The effectiveness of the proposal is demonstrated through two examples extracted from the literature

Information and Knowledge Valuation using the Information Theory and Informative Matrices

For a more concrete analysis of the quantification of knowledge, one must normalize the quantification of data and information. One must, without entering into excessive detail, resort to the information theory, recognizing three features that data, information and knowledge have in common: weight, content and quantity. The following article is an introduction to and conceptualization, in the light of the Information Theory (IT), of the quantification of information and knowledge by means of informative matrices and a normalization valid for every IT organization. Key words: Data, information, knowledge, informative quantity, informative weight, informative content, informative matrix, information theory, generate

Detecting Overweight Children in Primary Care: Do National Data Reflect the Typical Urban Practice?

The article presents a study which aims to obtain data about the feasibility of detecting risk for overweight and overweight in infants and young children seen for well-child visits based on pediatricians\u27 standard practice, to compare these estimates with the national data, and to compare the data gathered during well-child visits with data collected during well-child visits with data obtained in preschool children seen for a sick-child visit. It was stated that earlier children started increasing in adiposity, the greater the risk for being obese as adolescents and adults with 40 percent of infants whose weight was above the 95th percentile reported to be overweight as adults. However, there is no agreement on the evaluation of overweight in infants who are less than 2 years of age

Photochemistry of RNA, RNA Monomers, and Plausible Prebiotic Precursors

Sunlight is the primary source of energy to promote change on Earth. In this context, ultraviolet radiation can be thought as a catalyst of chemical change to refine chemical feedstocks and facilitate their transformations into the building blocks of life. To establish reasonable environmental constraints for the chemical origins of life, it is central to understand how the photochemical reactivity or photochemical resistance of prebiotic molecules might have supported the formation of the RNA monomers on the Earth\u27s surface and particularly in aqueous solution. In this chapter, the photochemistry of the RNA monomers and several conceivably important prebiotic precursors are reviewed. The emphasis is on delineating the primary electronic relaxation or photochemical reaction pathways that may have enabled the accumulation and the selection of the RNA monomers as the building blocks of life during prebiotic times. Finally, the moderately investigated photochemistry of RNA is summarized and contrasted to that of DNA. It is surmised that the enhanced structural rigidity and the increased excitation delocalization length in RNA may have conspired during prebiotic times for RNA oligomers to prosper under the otherwise harsh ultraviolet radiation conditions of early Earth

Effects of walking speed and age on the muscle forces of unimpaired gait subjects

Clinical gait analysis provides great contributions to the understanding of gait disorders and also provides a mean for a more comprehensive treatment plan. However, direct measures of muscle forces are difficult to obtain in clinical settings because it generally requires invasive techniques. Techniques of musculoskeletal modeling have been used for several decades to improve the benefits of clinical gait analysis, but many of the previous studies were focused on analyzing separately the muscle forces distribution of children or adult subjects with only one condition of walking speed. For these reason, the present study aims to enhance the current literature by describing the age and speed gait effects on muscle forces during walking. We used a musculoskeletal model with 23 degrees of freedom and 92 musculotendon actuators to represent 76 muscles in the lower extremities and torso. The computed muscle control algorithm was used to estimate the muscle forces from the kinematics and to adjust the model obtained in the residual reduction algorithm. We find that hamstrings has an important peak in the mid-stance phase in the adult group but this peak disappears in the children group with the same walking speed condition. Furthermore, the rectus femoris presents an increase in the muscle force during the pre- and mid-swing in concordance with the increment in the walking speed of subjects. This behavior could be associated with the role that the rectus femoris has in the acceleration of the knee joint. Finally, we show that the soleus is the muscle that perform the major force throughout the gait cycle regardless of age and walking speed.Fil: Fliger, Carlos G.. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Crespo, Marcos J.. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Braidot, Ariel A.. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Ravera, Emiliano Pablo. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Differences in Demographic, Behavioral, and Biological Variables Between Those With Valid and Invalid Accelerometry Data: Implications for Generalizability

Background: The exclusion of participants with invalid accelerometry data (IAD) may lead to biased results and/or lack of generalizability in large population studies. The purpose of this study was to investigate whether demographic, behavioral, and biological differences occur between those with IAD and valid accelerometry data (VAD) among adults using a representative sample of the civilian noninstitutionalized U.S. population. Methods: Ambulatory participants from NHANES (2003-2004) who were 20-85 years of age were included in the current study and wore an ActiGraph 7164 accelerometer for 7 days. A valid person was defined as those with 4 or more days of at least 10+ hrs of monitoring per day. Among adults (20-85 yrs), 3088 participants provided VAD and 987 provided IAD. Demographic, behavioral, and biological information were obtained from the household interview or from data obtained in a mobile examination center. Results: Differences were observed in age, BMI, ethnicity, education, smoking status, marital status, use of street drugs, current health status, HDL-cholesterol, C-reactive protein, self-reported vigorous physical activity, and plasma glucose levels between those with VAD and IAD. Conclusions: Investigators should take into consideration the potential cut-off bias in interpreting results based on data that excludes IAD participants

An orthogonal synthetic approach to nonsymmetrical bisazolyl 2,4,6-trisubstituted pyridines

A three-step synthetic route giving access to nonsymmetrical bisazolyl 2,4,6-trisubstituted pyridines with different substituents on the pyrazole, indazole, and pyridine heterocycles is described. From the readily available 4-bromo-2,6-difluoropyridine, both fluorine atoms allow for easy selective stepwise substitution, and the bromine atom provides easy access to additional functionalities through both Suzuki and Sonogashira Pd(0) cross-coupling reactions. These synthons represent optimal structures as building blocks in complexation and metalloorganic structures for the tuning of their chelating and photophysical propertie

Lower Nutritional Status and Higher Food Insufficiency in Frail Older US Adults

Frailty is a state of decreased physical functioning and a significant complication of ageing. We examined frailty, energy and macronutrient intake, biomarkers of nutritional status and food insufficiency in US older adult (age ≥ 60 years) participants of the Third National Health and Nutrition Examination Survey (4731). Frailty was defined as meeting ≥ 2 and pre-frailty as meeting one of the following four-item criteria: (1) slow walking; (2) muscular weakness; (3) exhaustion and (4) low physical activity. Intake was assessed by 24 h dietary recall. Food insufficiency was self-reported as ‘sometimes’ or ‘often’ not having enough food to eat. Analyses were adjusted for sex, race, age, smoking, education, income, BMI, other co-morbid conditions and complex survey design. Prevalence of frailty was highest among people who were obese (20•8 %), followed by overweight (18•4 %), normal weight (16•1 %) and lowest among people who were under- weight (13•8 %). Independent of BMI, daily energy intake was lowest in people who were frail, followed by pre-frail and highest in people who were not frail (6648 (SE 130), 6966 (SE 79) and 7280 (SE 84) kJ, respectively, P, 0•01). Energy-adjusted macronutrient intakes were similar in people with and without frailty. Frail (adjusted OR (AOR) 4•7; 95 % CI 1•7, 12•7) and pre-frail (AOR 2•1; 95 % CI 0•8, 5•8) people were more likely to report being food insufficient than not frail people. Serum albumin, carotenoids and Se levels were lower in frail adults than not frail adults. Research is needed on targeted interventions to improve nutritional status and food insufficiency among frail older adults, while not necessarily increasing BMI

Objectively-Measured Physical Activity and C-Reactive Protein: NHANES 2003–2004

The association between physical activity (PA) and C-reactive protein (CRP) is inconsistent, with nearly all studies using self-report measures of PA. The purpose of this study was to examine the association between objectively-measured PA and CRP in U.S. adults and children. Adults (N=2912) and children (N=1643) with valid accelerometer data and CRP data were included in the analyses. Logistic regression analysis was used to assess the odds of meeting physical activity guidelines across CRP quartiles for children and among adults with low, average, and high CRP levels. For adults, after adjustments for age, gender, race, body mass index, smoking, diabetes, and high density lipoprotein cholesterol (HDL-C), compared to those with low CRP levels, odds ratios were 0.59 (CI = 0.45–0.77) and 0.46 (CI = 0.28–0.76) for participants with average and high CRP levels, respectively. For children, after adjustments for age, gender, race, weight status, and HDLC, compared to those in CRP quartile 1, odds ratios were 0.96 (CI = 0.5–1.84), 1.23 (CI = 0.71– 2.12), and 0.79 (CI = 0.33–1.88) for participants in quartiles 2, 3, and 4, respectively. Objectivelymeasured PA is inversely associated with CRP in adults, with PA not related to CRP in children