Fundamentals of Signal Processing Applied to Rotating Machinery Diagnostics

TutorialRotating machinery diagnostics have been, and will be, a critical area in the Oil and Gas Industry. Though in the early days oscilloscopes and spectrum analyzers were typically used to analyze vibration data, in recent years, technological advances in computers have made it possible to make use of them in solving machinery problems. However, it becomes critical to accept the fact that in order to manipulate vibration signals in a software environment, they have to be previously transformed into digital format. Even though information on the various signal processing techniques are readily available, most of the time, the manner in which this topic is discussed tends to be somehow theoretical. This tutorial intends to provide a summary of these techniques, but most importantly, the link between the basic theory and real applications. It also emphasizes how choosing the wrong parameters in the data acquisition device will definitely affect the quality of vibration data, critical to solving machinery problems

Modulated phases of a 1D sharp interface model in a magnetic field

We investigate the ground states of 1D continuum models having short-range ferromagnetic type interactions and a wide class of competing longer-range antiferromagnetic type interactions. The model is defined in terms of an energy functional, which can be thought of as the Hamiltonian of a coarse-grained microscopic system or as a mesoscopic free energy functional describing various materials. We prove that the ground state is simple periodic whatever the prescribed total magnetization might be. Previous studies of this model of frustrated systems assumed this simple periodicity but, as in many examples in condensed matter physics, it is neither obvious nor always true that ground states do not have a more complicated, or even chaotic structure.Comment: 12 pages, 3 figure

Checkerboards, stripes and corner energies in spin models with competing interactions

We study the zero temperature phase diagram of Ising spin systems in two dimensions in the presence of competing interactions, long range antiferromagnetic and nearest neighbor ferromagnetic of strength J. We first introduce the notion of a "corner energy" which shows, when the antiferromagnetic interaction decays faster than the fourth power of the distance, that a striped state is favored with respect to a checkerboard state when J is close to J_c, the transition to the ferromagnetic state, i.e., when the length scales of the uniformly magnetized domains become large. Next, we perform detailed analytic computations on the energies of the striped and checkerboard states in the cases of antiferromagnetic interactions with exponential decay and with power law decay r^{-p}, p>2, that depend on the Manhattan distance instead of the Euclidean distance. We prove that the striped phase is always favored compared to the checkerboard phase when the scale of the ground state structure is very large. This happens for J\lesssim J_c if p>3, and for J sufficiently large if 2<p<=3. Many of our considerations involving rigorous bounds carry over to dimensions greater than two and to more general short-range ferromagnetic interactions.Comment: 21 pages, 3 figure

Uniaxial and biaxial soft deformations of nematic elastomers

We give a geometric interpretation of the soft elastic deformation modes of nematic elastomers, with explicit examples, for both uniaxial and biaxial nematic order. We show the importance of body rotations in this non-classical elasticity and how the invariance under rotations of the reference and target states gives soft elasticity (the Golubovic and Lubensky theorem). The role of rotations makes the Polar Decomposition Theorem vital for decomposing general deformations into body rotations and symmetric strains. The role of the square roots of tensors is discussed in this context and that of finding explicit forms for soft deformations (the approach of Olmsted).Comment: 10 pages, 10 figures, RevTex, AmsTe

Dietary patterns in adult population from Argentina

1p.Background and objectives: Dietary patterns (DP) have been used to identify different combinations of foods that may be associated with mortality and risk of chronic disease. The objective of this study was to identify DP in the adult population of Argentina, and explore associations with socio-demographic features. Methods: We defined DP among 3,000 adults between 35 to 74 years old, participating in CESCAS I, a population-based cohort study carried out in two cities in Argentina, Marcos Paz and Bariloche. Data on food intake was obtained from a validated self-administered food frequency questionnaire. Principal component Analysis (PCA) was used to identify DP. A summary score for each pattern was then derived and used in multiple regression analysis to examine the relationship between DP and socio-demographic variables. Results: Using PCA, we identified 3 major eating patterns. The first factor (Traditional dietary pattern), was characterized by a high intake of refined grains, red meat, whole fat dairy products, vegetable oils, and ?mate?, a traditional South American infused drink frequently consumed in Argentina; the second factor (Healthy dietary pattern), was characterized by a high intake of vegetables, fruit, low fat dairy products, whole grains, and legumes; the third factor (Processed-food dietary pattern) consisted mainly of processed meat, snacks, pizza, and ?empanadas?, a stuffed bread baked or fried. After adjusting for energy intake, we found that DP were associated with age, gender, and educational level. Healthy DP score was higher among women and high educational level (p=0.001) while men and young people scored significantly higher in the Processed-food DP (p=0.01). Conclusions: Local DP has been identified in our population. This study will provide useful information to set priority targets for nutrition interventions.https://www.karger.com/Article/PDF/354245Fil: Elorriaga, Natalia. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ciencias de la Salud. Universidad de Buenos Aires. Escuela de Nutrición. Cátedra de Evaluación Nutricional; Argentina.Fil: Defagó, María Daniela. Universidad Nacional de Córdoba. Escuela de Nutrición. Universidad de Tulane. Escuela de Salud Pública. Cátedra de Salud Cardiovascular. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ciuencias de la Salud; Argentina.Fil: Gutiérrez, Laura: Universidad Nacional de Rosario. Cátedra de Bioestadística y Metodología de la Investigación. Universidad de Buenos Aires. Facultad de Medicina. Cátedra Estadística de la Maestría en Efectividad Clínica; Argentina.Fil: Poggio, Rosana. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Buenos Aires. Escuela de Medicina; Argentina.Fil: Irazola, Vilma. Universidad de Buenos Aires. Escuela de Medicina. Maestría en Efectividad Clínica. Cátedra de Medición de Resultados, Estadística Avanzada y Bioestadística; Argentina.Nutrición, Dietétic

Cyclic-AMP regulates postnatal development of neural and behavioral responses to NaCl in rats

During postnatal development rats demonstrate an age-dependent increase in NaCl chorda tympani (CT) responses and the number of functional apical amiloride-sensitive epithelial Na+channels (ENaCs) in salt sensing fungiform (FF) taste receptor cells (TRCs). Currently, the intracellular signals that regulate the postnatal development of salt taste have not been identified. We investigated the effect of cAMP, a downstream signal for arginine vasopressin (AVP) action, on the postnatal development of NaCl responses in 19–23 day old rats. ENaC-dependent NaCl CT responses were monitored after lingual application of 8-chlorophenylthio-cAMP (8-CPT-cAMP) under open-circuit conditions and under ±60 mV lingual voltage clamp. Behavioral responses were tested using 2 bottle/24h NaCl preference tests. The effect of [deamino-Cys1, D-Arg8]-vasopressin (dDAVP, a specific V2R agonist) was investigated on ENaC subunit trafficking in rat FF TRCs and on cAMP generation in cultured adult human FF taste cells (HBO cells). Our results show that in 19–23 day old rats, the ENaC-dependent maximum NaCl CT response was a saturating sigmoidal function of 8-CPT-cAMP concentration. 8-CPT-cAMP increased the voltage-sensitivity of the NaCl CT response and the apical Na+ response conductance. Intravenous injections of dDAVP increased ENaC expression and γ-ENaC trafficking from cytosolic compartment to the apical compartment in rat FF TRCs. In HBO cells dDAVP increased intracellular cAMP and cAMP increased trafficking of γ- and δ-ENaC from cytosolic compartment to the apical compartment 10 min post-cAMP treatment. Control 19–23 day old rats were indifferent to NaCl, but showed clear preference for appetitive NaCl concentrations after 8-CPT-cAMP treatment. Relative to adult rats, 14 day old rats demonstrated significantly less V2R antibody binding in circumvallate TRCs. We conclude that an age-dependent increase in V2R expression produces an AVP-induced incremental increase in cAMP that modulates the postnatal increase in TRC ENaC and the neural and behavioral responses to NaCl

Toward the PSTN/Internet Inter-Networking--Pre-PINT Implementations

This document contains the information relevant to the development of the inter-networking interfaces underway in the Public Switched Telephone Network (PSTN)/Internet Inter-Networking (PINT) Working Group. It addresses technologies, architectures, and several (but by no means all) existing pre-PINT implementations of the arrangements through which Internet applications can request and enrich PSTN telecommunications services. The common denominator of the enriched services (a.k.a. PINT services) is that they combine the Internet and PSTN services in such a way that the Internet is used for non-voice interactions, while the voice (and fax) are carried entirely over the PSTN. One key observation is that the pre-PINT implementations, being developed independently, do not inter-operate. It is a task of the PINT Working Group to define the inter-networking interfaces that will support inter-operation of the future implementations of PINT services

Compliant glass–polymer hybrid single ion-conducting electrolytes for lithium batteries

This study describes hybrid single ion-conducting electrolytes based on inorganic sulfide glasses and perfluoropolyether polymers for lithium batteries. Herein, it is shown that hybrid electrolytes provide a compelling alternative to the traditional glass, ceramic, or polymer battery electrolytes. These electrolytes present high transference numbers, unprecedented ionic conductivities at room temperature, and excellent electrochemical stability, and they limit the dissolution of lithium polysulfides. The results in this work represent a significant step toward addressing the challenges of enabling the next generation cathodes, such as lithium nickel manganese cobalt oxide and sulfur

Shape programming for narrow ribbons of nematic elastomers

Using the theory of Γ-convergence, we derive from three-dimensional elasticity new one-dimensional models for non-Euclidean elastic ribbons, i.e., ribbons exhibiting spontaneous curvature and twist. We apply the models to shape-selection problems for thin films of nematic elastomers with twist and splay-bend texture of the nematic director. For the former, we discuss the possibility of helicoid-like shapes as an alternative to spiral ribbons

Custom-fit radiolucent cranial implants for neurophysiological recording and stimulation

Background: Recording and manipulating neural activity in awake behaving animal models requires long-term implantation of cranial implants that must address a variety of design considerations, which include preventing infection, minimizing tissue damage, mechanical strength of the implant, and MRI compatibility. New method: Here we address these issues by designing legless, custom-fit cranial implants using structural MRI-based reconstruction of the skull and that are made from carbon-reinforced PEEK. Results: We report several novel custom-fit radiolucent implant designs, which include a legless recording chamber, a legless stimulation chamber, a multi-channel microdrive and a head post. The fit to the skull was excellent in all cases, with no visible gaps between the base of the implants and the skull. The wound margin was minimal in size and showed no sign of infection or skin recession. Comparison with existing methods: Cranial implants used for neurophysiological investigation in awake behaving animals often employ methyl methacrylate (MMA) to serve as a bonding agent to secure the implant to the skull. Other designs rely on radially extending legs to secure the implant. Both of these methods have significant drawbacks. MMA is toxic to bone and frequently leads to infection while radially extending legs cause the skin to recede away from the implant, ultimately exposing bone and proliferating granulation tissue. Conclusions: These radiolucent implants constitute a set of technologies suitable for reliable long-term recording, which minimize infection and tissue damage.National Eye Institute (EY017291)National Eye Institute (EY017292)National Institutes of Health (U.S.) (National Research Service Award, EY020692