Sample records for assisted circulation

  1. Concepts in Assisted Circulation

    Lefemine, Armand A.; Dunbar, Jacob; DeLucia, Anthony


    Assisted circulation by extracorporeal and extracardiac bypass techniques must be based on the requirements of the heart and of the total body, though these may differ. The cardiac problem in cardiogenic shock is more likely to be a biventricular problem demanding decompression of both sides. Extra pulmonary oxygenation should be avoided because of complexity in long-term use. Principles of assisted circulation may be applied in an extra-thoracic temporary manner or as an intracorporeal long-...

  2. A novel interface for hybrid mock circulations to evaluate ventricular assist devices.

    Ochsner, Gregor; Amacher, Raffael; Amstutz, Alois; Plass, André; Schmid Daners, Marianne; Tevaearai, Hendrik; Vandenberghe, Stijn; Wilhelm, Markus J; Guzzella, Lino


    This paper presents a novel mock circulation for the evaluation of ventricular assist devices (VADs), which is based on a hardware-in-the-loop concept. A numerical model of the human blood circulation runs in real time and computes instantaneous pressure, volume, and flow rate values. The VAD to be tested is connected to a numerical-hydraulic interface, which allows the interaction between the VAD and the numerical model of the circulation. The numerical-hydraulic interface consists of two pressure-controlled reservoirs, which apply the computed pressure values from the model to the VAD, and a flow probe to feed the resulting VAD flow rate back to the model. Experimental results are provided to show the proper interaction between a numerical model of the circulation and a mixed-flow blood pump. PMID:23204266

  3. Model of arterial tree and peripheral control for the study of physiological and assisted circulation.

    Lanzarone, E; Liani, P; Baselli, G; Costantino, M L


    Peripheral vasomotion, interstitial liquid exchange, and cardiovascular system behaviour are investigated by means of a lumped parameter model of the systemic and peripheral circulation, from the aortic valve to the venules. This modelling work aims at combining arterial tree hemodynamics description, active peripheral flow regulation, and fluid exchange. The arterial compartment is constructed with 63 RCL segments and 30 peripheral districts including myogenic control on arterioles, metabolic control on venules, and Starling filtration through capillary membrane. The arterial behaviour is characterised as to the long term stability of pressure/flow waves in the different segments. Peripheral districts show autoregulatory capabilities against pressure changes over a wide range and also self-sustained oscillations mimicking vasomotor activity. A preliminary study was carried out as to the model response to changes induced by cardiopulmonary bypass (CPB). Among the induced alterations, the system responds mainly to hemodilution, which increased peripheral fluid loss and oedema beyond the compensatory capabilities of local regulation mechanisms. This resulted in an overall increase total arterial resistance. Local transport deficits were assessed for each district according to the different metabolic demand. This study shows the requirement of a suitable description of both arteries and peripheral mechanisms in order to describe cardiovascular response non-physiological conditions, as well as assisted circulation or other pathological conditions. PMID:17011809

  4. Interaction of an idealized cavopulmonary circulation with mechanical circulatory assist using an intravascular rotary blood pump.

    Bhavsar, Sonya S; Moskowitz, William B; Throckmorton, Amy L


    This study evaluated the performance of an intravascular, percutaneously-inserted, axial flow blood pump in an idealized total cavopulmonary connection (TCPC) model of a Fontan physiology. This blood pump, intended for placement in the inferior vena cava (IVC), is designed to augment pressure and blood flow from the IVC to the pulmonary circulation. Three different computational models were examined: (i) an idealized TCPC without a pump; (ii) an idealized TCPC with an impeller pump; and (iii) an idealized TCPC with an impeller and diffuser pump. Computational fluid dynamics analyses of these models were performed to assess the hydraulic performance of each model under varying physiologic conditions. Pressure-flow characteristics, fluid streamlines, energy augmentation calculations, and blood damage analyses were evaluated. Numerical predictions indicate that the pump with an impeller and diffuser blade set produces pressure generations of 1 to 16 mm Hg for rotational speeds of 2000 to 6000 rpm and flow rates of 1 to 4 L/min. In contrast, for the same flow range, the model with the impeller only in the IVC demonstrated pressure generations of 1 to 9 mm Hg at rotational speeds of 10,000 to 12,000 rpm. Influence of blood viscosity was found to be insignificant at low rotational speeds with minimal performance deviation at higher rotational speeds. Results from the blood damage index analyses indicate a low probability for damage with maximum damage index levels less than 1% and maximum fluid residence times below 0.6 s. The numerical predictions further indicated successful energy augmentation of the TCPC with a pump in the IVC. These results support the continued design and development of this cavopulmonary assist device. PMID:20964699

  5. The use of a numerical model to simulate the cavo-pulmonary assistance in Fontan circulation: a preliminary verification.

    Di Molfetta, Arianna; Amodeo, Antonio; Fresiello, Libera; Filippelli, Sergio; Pilati, Mara; Iacobelli, Roberta; Adorisio, Rachele; Colella, Dionisio; Ferrari, Gianfranco


    The lack of an established experience on the use of VAD for the cavo-pulmonary assistance leads to the need of dedicated VADs development and animal experiments. A dedicated numerical model could support clinical and experimental strategies design and new VADs testing. The aim of this work is to perform a preliminary verification of a lumped parameter model of the cardiovascular system to simulate Fontan physiology and the effect of cavo-pulmonary assistance. Literature data of 4 pigs were used to simulate animals' baseline, and then the model was tested in simulating Fontan circulation and cavo-pulmonary-assisted condition comparing the simulation outcome (Sim) with measured literature data (Me). The results show that the numerical model can well reproduce experimental data in all three conditions (baseline, Fontan and assisted Fontan) [cardiac output (l/min): Me = 2.8 ± 1.7, Sim = 2.8 ± 1.8; ejection fraction (%): Me = 57 ± 17, Sim = 54 ± 17; arterial systemic pressure (mmHg): Me = 41.8 ± 18.6, Sim = 43.8 ± 18.1; pulmonary arterial pressure (mmHg): Me = 15.4 ± 8.9, Sim = 17.7 ± 9.9; caval pressure (mmHg): Me = 6.8 ± 4.1, Sim = 7 ± 4.6]. Systolic elastance, arterial systemic and arterial pulmonary resistances increase (10, 69, and 100 %) passing from the biventricular circulation to the Fontan physiology and then decrease (21, 39, and 50 %) once the VAD was implanted. The ventricular external work decreases (71 %) passing from the biventricular circulation to the Fontan physiology and it increases three times after the VAD implantation in parallel with the VAD power consumption. A numerical model could support clinicians in an innovative and challenging field as the use of VAD to assist the Fontan physiology and it could be helpful to personalize the VAD insertion on the base of ventricular systo-diastolic function, circulatory parameters and energetic variables. PMID:26545595

  6. Mechanical cavopulmonary assist for the univentricular Fontan circulation using a novel folding propeller blood pump.

    Throckmorton, Amy L; Ballman, Kimberly K; Myers, Cynthia D; Litwak, Kenneth N; Frankel, Steven H; Rodefeld, Mark D


    A blood pump specifically designed to operate in the unique anatomic and physiologic conditions of a cavopulmonary connection has never been developed. Mechanical augmentation of cavopulmonary blood flow in a univentricular circulation would reduce systemic venous pressure, increase preload to the single ventricle, and temporarily reproduce a scenario analogous to the normal two-ventricle circulation. We hypothesize that a folding propeller blood pump would function optimally in this cavopulmonary circulation. The hydraulic performance of a two-bladed propeller prototype was characterized in an experimental flow loop using a blood analog fluid for 0.5-3.5 lpm at rotational speeds of 3,600-4,000 rpm. We also created five distinctive blood pump designs and evaluated their hydraulic performance using computational fluid dynamics (CFD). The two-bladed prototype performed well over the design range of 0.5-3.5 lpm, producing physiologic pressure rises of 5-18 mm Hg. Building upon this proof-of-concept testing, the CFD analysis of the five numerical models predicted a physiologic pressure range of 5-40 mm Hg over 0.5-4 lpm for rotational speeds of 3,000-7,000 rpm. These preliminary propeller designs and the two-bladed prototype achieved the expected hydraulic performance. Optimization of these configurations will reduce fluid stress levels, remove regions of recirculation, and improve the hydraulic performance of the folding propeller. This propeller design produces the physiologic pressures and flows that are in the ideal range to mechanically support the cavopulmonary circulation and represents an exciting new therapeutic option for the support of a univentricular Fontan circulation. PMID:18043158

  7. Beyond the VAD: Human Factors Engineering for Mechanically Assisted Circulation in the 21st Century.

    Throckmorton, Amy L; Patel-Raman, Sonna M; Fox, Carson S; Bass, Ellen J


    Thousands of ventricular assist devices (VADs) currently provide circulatory support to patients worldwide, and dozens of heart pump designs for adults and pediatric patients are under various stages of development in preparation for translation to clinical use. The successful bench-to-bedside development of a VAD involves a structured evaluation of possible system states, including human interaction with the device and auxiliary component usage in the hospital or home environment. In this study, we review the literature and present the current landscape of preclinical design and assessment, decision support tools and procedures, and patient-centered therapy. Gaps of knowledge are identified. The study findings support the need for more attention to user-centered design approaches for medical devices, such as mechanical circulatory assist systems, that specifically involve detailed qualitative and quantitative assessments of human-device interaction to mitigate risk and failure. PMID:26511100

  8. [Evaluation of 2 years' experience with assisted circulation by diastolic counterpulsation].

    Vernant, P; Lellouche, D; Bouillot, M; Loisance, D; Nitenberg, A


    The authors report their two years' experience of circulatory assistance by diastolic counter-pulsation with an intra-aortic balloon. This technique was used in 23 patients: 9 cases of cardiogenic shock due to acute myocardial infarction, 9 septal ruptures, 1 rupture of the papillary muscle of the mitral valve, 1 acute ventricular aneurysm, 2 high risk coronary arteriographies and 1 case of early post-infarction recurrent ischemia. It confirms the gravity of cardiogenic shock as, in spite of the frequent improvement in hemodynamic parameters under counter-pulsation, there was only one survivor. The efficacy is greater in cases of septal rupture, where the author obtained 3 survivors out of 6 operated cases. The security of the method and its innocuity permit one to carry out high risk coronary arteriography and extend the indications for circulatory assistance, to certain cases of unstable angina or early recurrent anginal following acute infarction. PMID:1229961

  9. Conceptual Design of a Natural Circulation Test Loop Assisted by System Code

    This paper reports the results of the simulation of natural circulation (NC) loop performance with the aid of Relap5 thermalhydraulic system code. This loop has been constructed for the analysis of relevant thermalhydraulic parameters of a nuclear reactor. Changes in the electric power and in the elevation of the heat sink relatively to the heat source are allowed. In this study two different scenarios for the elevation of the heat sink relatively to the heat source are considered assuming the same power level. The analysis shows that NC is established and fluid temperatures and mass flow rates achieve reasonable values. Comparison of the simulation results with reference experimental data base, not documented in this paper, shows the quality of the achieved design. Increase of mass flow rate, lower fluid temperature at the heated region inlet and lower average void fraction in the loop occur owing to higher elevations. These characteristics lead to an increased power removal capability in the NC loop. (author)


    V. S. Suskova


    Full Text Available The study has shown that early diagnosis of the type and degree of immune disturbances in preparation for the operation and the first signs of multiorgan failure and septic complications in the postoperative period in cardiac surgery patients were the rationale for the earlier substitution immunocorrection by immunomodulators of cytokine nature and intravenous immunoglobulin. It allowed increasing the efficiency of the treatment of postoperative complications and lower mortality after operations with artificial and assist circulation

  11. L’assistance juridique japonaise aux pays dits « émergents » d’Asie Japanese Legal Technical Assistance to Emerging Countries in Asia. A Contribution to the Pluralistic Approach to the Circulation of Law

    Isabelle Giraudou


    Full Text Available Fort d’un système normatif à la croisée de plusieurs traditions juridiques, le Japon entend participer plus résolument au développement actuel des modes de circulation du droit via notamment sa poli­tique de coopération internationale en matière d’assistance juridique et judiciaire aux pays émergents d’Asie. Cet article examine les particularités de la politique japonaise d’assistance en prenant appui sur des réflexions plus larges concernant les modalités contemporaines d’interaction des normes et le renouvellement des processus d’élaboration du droit. Cela permet de cerner les contradictions d’une assistance juridique conçue à la fois comme outil d’uniformisation du droit et instrument de coordination normative, au service d’une approche pluraliste de la circulation des normes.On the strength of a legal system stemming from various traditions of law, Japan is trying to participate more actively in the current development of the circulation of law, especially through its policy of international cooperation in the field of legal technical assistance and judicial assistance to emerging countries in Asia. This paper scrutinizes the specificities of the Japanese policy in the field drawing on broader analyses about contemporary means of interaction between norms and the reshaping of the processes by which law is elaborated. This may help shed some light on the contradictions of a form legal technical assistance that is conceived both as a tool for the standardization of law and a device that facilitates the coordination of laws at the service of an approach of legal pluralism.

  12. Uso de bomba centrífuga no pós-operatório de cirurgia cardíaca Assisted circulation in cardiac surgery

    Paulo M Pêgo-Fernandes


    .In patients with cardiogenic shock following cardiopulmonary bypass, not responsive to intraortic balloon pump and drugs, the centrifugal pumps are the first option in many centers. These centers that use modern vortex pumps cite their simplicity, availability, relatively low cost, and low amount of blood trauma. The aim of this study is to describe the experience of InCór with 8 patients submitted to assisted circulation with biopump from May 1990 to December 1991 . Intraortic balloon counterpulsation was used in these 8 patients with conventional medical therapy. Their ages ranged from 54 to 66 . Three patients were submitted to coronary bypass, 2 to mitral valve replacement, 2 to left ventricular aneurysm correction and 1 to heart transplantation. Left atrial to aortic bypass was done in 7 patients and in 1 , right atrial to pulmonary bypass. The patients were assisted from 18 to 12 6 hours. Three patients died during assisted circulation: 2 were in bridge to transplantation and didn't achieve donor organ, and 1 died due to bleeding and acute renal failure. Five (62.5% patients were weaned from the device, but 2 died at hospital, 1 due to respiratory failure and 1 due to neurologic and renal failure. When we compared the clinical evaluation with CKMB, we noted that 3 patients with CKMB greater than 80 died, 2 during assisted circulation. In 5 patients with CKMB less than 80 , 4 were weaned from the device and 3 were discharged from the hospital. Two patients discharged from the hospital are in NYHA functional class II and 1 in class I. The early utilization of assisted circulation will lead to better results in this group of high risk patients.

  13. A chip assisted immunomagnetic separation system for the efficient capture and in situ identification of circulating tumor cells.

    Tang, Man; Wen, Cong-Ying; Wu, Ling-Ling; Hong, Shao-Li; Hu, Jiao; Xu, Chun-Miao; Pang, Dai-Wen; Zhang, Zhi-Ling


    The detection of circulating tumor cells (CTCs), a kind of "liquid biopsy", represents a potential alternative to noninvasive detection, characterization and monitoring of carcinoma. Many previous studies have shown that the number of CTCs has a significant relationship with the stage of cancer. However, CTC enrichment and detection remain notoriously difficult because they are extremely rare in the bloodstream. Herein, aided by a microfluidic device, an immunomagnetic separation system was applied to efficiently capture and in situ identify circulating tumor cells. Magnetic nanospheres (MNs) were modified with an anti-epithelial-cell-adhesion-molecule (anti-EpCAM) antibody to fabricate immunomagnetic nanospheres (IMNs). IMNs were then loaded into the magnetic field controllable microfluidic chip to form uniform IMN patterns. The IMN patterns maintained good stability during the whole processes including enrichment, washing and identification. Apart from its simple manufacture process, the obtained microfluidic device was capable of capturing CTCs from the bloodstream with an efficiency higher than 94%. The captured cells could be directly visualized with an inverted fluorescence microscope in situ by immunocytochemistry (ICC) identification, which decreased cell loss effectively. Besides that, the CTCs could be recovered completely just by PBS washing after removal of the permanent magnets. It was observed that all the processes showed negligible influence on cell viability (viability up to 93%) and that the captured cells could be re-cultured for more than 5 passages after release without disassociating IMNs. In addition, the device was applied to clinical samples and almost all the samples from patients showed positive results, which suggests it could serve as a valuable tool for CTC enrichment and detection in the clinic. PMID:26928405

  14. Circulating ultrasound-assisted extraction, countercurrent chromatography, and liquid chromatography for the simultaneous extraction, isolation, and analysis of the constituents of Uncaria tomentosa.

    Zhang, Yuchi; Liu, Chunming; Qi, Yanjuan; Li, Sainan; Pan, Yan; Li, Yuchun


    A hyphenated automated technique for the online extraction, isolation, analysis, and identification of natural organic compounds was established. Circulating ultrasound-assisted extraction (CUAE) was coupled with countercurrent chromatography (CCC), high performance liquid chromatography (HPLC), and a diode array detector (DAD). This approach was applied to the fractionation and purification of alkaloids from Uncaria tomentosa. A biphasic solvent system of chloroform-methanol-water (6:4:5, v:v:v) was used for the CUAE and CCC separation of compounds from 500 g of U. tomentosa. Two CUAE/CCC/HPLC/DAD modes were established. Either the upper aqueous phase or the lower organic phase of the solvent system could be used as the extraction solvent. The target compounds were extracted by CUAE, and the extract was pumped into a sample loop before being directly injected into the CCC column, or pre-purified using a flash chromatography column before injection. The target compounds were eluted using either the organic or aqueous phase of the solvent system and the fractions were monitored using a UV detector. The target fractions were collected by a sample loop via a six-port valve, and analyzed by HPLC/DAD for purity and structural identification. This system isolated of 8.2mg, 7.4 mg, and 12.9 mg of rhynchophylline, corynoxine, and corynoxine B with HPLC purities of 96.15%, 95.34%, and 95.49%, respectively via the first mode; and isolated 26.6 mg, 24.6 mg, and 45.3mg of rhynchophylline, corynoxine, and corynoxine B with a HPLC purities of 98.22%, 97.18%, and 97.93% via the second mode. PMID:25725954

  15. Fetal Circulation

    ... Pressure High Blood Pressure Tools & Resources Stroke More Fetal Circulation Updated:Jul 8,2016 click to enlarge The ... fetal heart. These two bypass pathways in the fetal circulation make it possible for most fetuses to survive ...

  16. Lung Circulation.

    Suresh, Karthik; Shimoda, Larissa A


    The circulation of the lung is unique both in volume and function. For example, it is the only organ with two circulations: the pulmonary circulation, the main function of which is gas exchange, and the bronchial circulation, a systemic vascular supply that provides oxygenated blood to the walls of the conducting airways, pulmonary arteries and veins. The pulmonary circulation accommodates the entire cardiac output, maintaining high blood flow at low intravascular arterial pressure. As compared with the systemic circulation, pulmonary arteries have thinner walls with much less vascular smooth muscle and a relative lack of basal tone. Factors controlling pulmonary blood flow include vascular structure, gravity, mechanical effects of breathing, and the influence of neural and humoral factors. Pulmonary vascular tone is also altered by hypoxia, which causes pulmonary vasoconstriction. If the hypoxic stimulus persists for a prolonged period, contraction is accompanied by remodeling of the vasculature, resulting in pulmonary hypertension. In addition, genetic and environmental factors can also confer susceptibility to development of pulmonary hypertension. Under normal conditions, the endothelium forms a tight barrier, actively regulating interstitial fluid homeostasis. Infection and inflammation compromise normal barrier homeostasis, resulting in increased permeability and edema formation. This article focuses on reviewing the basics of the lung circulation (pulmonary and bronchial), normal development and transition at birth and vasoregulation. Mechanisms contributing to pathological conditions in the pulmonary circulation, in particular when barrier function is disrupted and during development of pulmonary hypertension, will also be discussed. © 2016 American Physiological Society. Compr Physiol 6:897-943, 2016. PMID:27065170

  17. Circulation economics

    Ingebrigtsen, Stig; Jakobsen, Ove


    Purpose - This paper is an attempt to advance the critical discussion regarding environmental and societal responsibility in economics and business. Design/methodology/approach - The paper presents and discusses as a holistic, organic perspective enabling innovative solutions to challenges...... concerning the responsible and efficient use of natural resources and the constructive interplay with culture. To reach the goal of sustainable development, the paper argues that it is necessary to make changes in several dimensions in mainstream economics. This change of perspective is called a turn towards...... presupposes a perspective integrating economic, natural and cultural values. Third, to organize the interplay between all stakeholders we introduce an arena for communicative cooperation. Originality/value - The paper concludes that circulation economics presupposes a change in paradigm, from a mechanistic...

  18. Microwave circulator design

    Linkhart, Douglas K


    Circulator design has advanced significantly since the first edition of this book was published 25 years ago. The objective of this second edition is to present theory, information, and design procedures that will enable microwave engineers and technicians to design and build circulators successfully. This resource contains a discussion of the various units used in the circulator design computations, as well as covers the theory of operation. This book presents numerous applications, giving microwave engineers new ideas about how to solve problems using circulators. Design examples are provided, which demonstrate how to apply the information to real-world design tasks.

  19. ÉTUDE HYDRAULIQUE DU CŒUR ARTIFICIEL IMPLANTABLE JARVIK-7-100 SUR UN BANC EXPÉRIMENTAL SIMULANT LA CIRCULATION SANGUINE : LE « MOCK-CIRCULATION ». Deuxième partie : courbes caractéristiques des pompes en parallèle : l'assistance ventriculaire gauche.

    Venet, Richard,; Dupont, T.; Léger, Philippe; Pavie, Alain


    L'objet de cet article est d'appliquer les lois de l'hydraulique des pompes à l'assistance ventriculaire gauche. Si on connait le débit et les pressions d'un cœur défaillant ainsi que les courbes caractéristiques du ventricule d'assistance, peut-on en déduire les débits et les pressions résultant de l'association en parallèle ? Matériels et méthodes. Le cœur artificiel Jarvik simule une insuffisance ventriculaire gauche par baisse de la pression d'air comprimé. Un ventricule d'assistance Nipp...

  20. Robot-Assisted Gynecologic Oncology Surgery

    Full Text Available ... do. 00:02:00 As you see, the first thing you notice is that the surgeon is ... have, as circulator, we have Debbie Johnson. As first assistant we have Lisa Jacobs Wilkinson. Our surgical ...

  1. Gaussian Fibonacci Circulant Type Matrices

    Zhaolin Jiang


    Full Text Available Circulant matrices have become important tools in solving integrable system, Hamiltonian structure, and integral equations. In this paper, we prove that Gaussian Fibonacci circulant type matrices are invertible matrices for n>2 and give the explicit determinants and the inverse matrices. Furthermore, the upper bounds for the spread on Gaussian Fibonacci circulant and left circulant matrices are presented, respectively.


    R. Naeije; CHESLER, N


    The pulmonary circulation is a high flow and low pressure circuit, with an average resistance of 1 mmHg.min.L−1 in young adults, increasing to 2.5 mmHg.min.L−1 over 4–6 decades of life. Pulmonary vascular mechanics at exercise are best described by distensible models. Exercise does not appear to affect the time constant of the pulmonary circulation or the longitudinal distribution of resistances. Very high flows are associated with high capillary pressures, up to a 20–25 mmHg threshold associ...

  3. Computer-assisted diagnostic procedure for multislice computed tomography for assessment of the pulmonary arterial circulation. Clinical relevance; Computerassistiertes Diagnoseverfahren fuer die Mehrschichtcomputertomographie zur Beurteilung der pulmonalarteriellen Strombahn. Klinische Bedeutung

    Malich, A. [Suedharz-Krankenhaus Nordhausen, Institut fuer Radiologie, Nordhausen (Germany); Hentrich, D. [Radiologisches Zentrum Seesen, Seesen (Germany); Hansch, A.; Teichgraeber, U. [Friedrich-Schiller-Universitaet Jena, Zentrum fuer Radiologie, Jena (Germany); Boettcher, J. [Waldklinikum Gera, Institut fuer diagnostische und interventionelle Radiologie, Gera (Germany)


    A recently developed CAD software which highlights intravascular thrombotic structures from multislice computed tomography (MSCT) data was tested regarding feasibility, interobserver reliability and effect on radiology reports. The CAD system ImageChecker {sup registered} CT-Lung was tested in a randomized double-blinded study on 160 MSCT datasets (standardized technical conditions) performed for suspected pulmonary embolism (PE). The CAD data and images were analyzed by three radiologists in an independent and blinded fashion. The data from all 160 cases could be analyzed and 604 CAD prompts were set. Using the CAD analysis significantly more PEs were found in the peripheral pulmonary arterial circulation than described in the initial report. In 38 cases the 3 radiologists in consensus scored the images with the CAD adjunct as PE positive in peripheral vessels, which were initially reported as negative. Despite differences in the evaluation between two radiologists the amended assessment of the imaging data using the CAD softwear was reliable. There was a significant correlation between D-dimer values and the number of embolic structures detected by the CAD analysis. The recently developed CAD system is a useful adjunct as second reader to detect subtle emboli in peripheral vessels of MSCT datasets. (orig.) [German] Zur Detektion intravasaler Kontrastmittel(KM)-Aussparungen der Pulmonalarterien in der Mehrschichtcomputertomographie (MSCT) wurde ein CAD-System entwickelt, das bzgl. der Anwendbarkeit, des Vergleichs zur radiologischen Beurteilung und der Ermittlung eines moeglichen Effekts auf den befundenen Radiologen getestet wurde. Das CAD-System ImageChecker {sup registered} CT-Lung wurde in einer randomisierten, doppelblinden Studie zur Nachverarbeitung von 160 technisch einheitlichen CT-Angiographien (MSCT unter dem klinischen Verdacht einer Lungenembolie) genutzt und die CAD-Daten durch 3 Radiologen zueinander, und bzgl. des initialen Befundes geblindet

  4. Surgical Assisting

    ... specific training over and above a degree in science, nursing, physician assisting, or another health profession. Prerequisites . Recommended eligibility requirements for admission into a surgical assisting program are: Bachelor of Science degree (or higher) Associate degree in an allied ...

  5. Assistive Technology

    ... Page Resize Text Printer Friendly Online Chat Assistive Technology Assistive technology (AT) is any service or tool that helps ... be difficult or impossible. For older adults, such technology may be a walker to improve mobility or ...

  6. Assisted Living

    ... overwhelming majority of residents are female. Assisted Living Philosophy The philosophy of assisted living is to provide personalized, resident ... loved ones to learn about the care provider philosophy . Freedom of Choice The most progressive state regulations ...


    Mail Office


    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or a piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.

  8. Resolvability in Circulant Graphs

    Muhammad SALMAN; Imran JAVAID; Muhammad Anwar CHAUDHRY


    A set W of the vertices of a connected graph G is called a resolving set for G if for every two distinct vertices u,v ∈ V(G) there is a vertex w ∈ W such that d(u,w) ≠ d(v,w).A resolving set of minimum cardinality is called a metric basis for G and the number of vertices in a metric basis is called the metric dimension of G,denoted by dim(G).For a vertex u of G and a subset S of V(G),the distance between u and S is the number mins∈s d(u,s).A k-partition H ={S1,S2,...,Sk} of V(G) is called a resolving partition if for every two distinct vertices u,v ∈ V(G) there is a set Si in Π such that d(u,Si) ≠ d(v,Si).The minimum k for which there is a resolving k-partition of V(G) is called the partition dimension of G,denoted by pd(G).The circulant graph is a graph with vertex set Zn,an additive group ofintegers modulo n,and two vertices labeled i and j adjacent if and only if i - j (mod n) ∈ C,where C C Zn has the property that C =-C and 0(∈) C.The circulant graph is denoted by Xn,△ where A =|C|.In this paper,we study the metric dimension of a family of circulant graphs Xn,3 with connection set C ={1,-n/2,n - 1} and prove that dim(Xn,3) is independent of choice of n by showing that 3 for all n =0 (mod 4),dim(X,n,3) ={ 4 for all n =2 (mod 4).We also study the partition dimension of a family of circulant graphs Xn,4 with connection set C ={±1,±2} and prove that pd(Xn,4) is independent of choice of n and show that pd(X5,4) =5 and 3 forall odd n≥9,pd(Xn,4) ={ 4 for all even n ≥ 6 and n =7.

  9. Circulation of Stars

    Boitani, P.


    Since the dawn of man, contemplation of the stars has been a primary impulse in human beings, who proliferated their knowledge of the stars all over the world. Aristotle sees this as the product of primeval and perennial “wonder” which gives rise to what we call science, philosophy, and poetry. Astronomy, astrology, and star art (painting, architecture, literature, and music) go hand in hand through millennia in all cultures of the planet (and all use catasterisms to explain certain phenomena). Some of these developments are independent of each other, i.e., they take place in one culture independently of others. Some, on the other hand, are the product of the “circulation of stars.” There are two ways of looking at this. One seeks out forms, the other concentrates on the passing of specific lore from one area to another through time. The former relies on archetypes (for instance, with catasterism), the latter constitutes a historical process. In this paper I present some of the surprising ways in which the circulation of stars has occurred—from East to West, from East to the Far East, and from West to East, at times simultaneously.

  10. Ocean General Circulation Models

    Yoon, Jin-Ho; Ma, Po-Lun


    1. Definition of Subject The purpose of this text is to provide an introduction to aspects of oceanic general circulation models (OGCMs), an important component of Climate System or Earth System Model (ESM). The role of the ocean in ESMs is described in Chapter XX (EDITOR: PLEASE FIND THE COUPLED CLIMATE or EARTH SYSTEM MODELING CHAPTERS). The emerging need for understanding the Earth’s climate system and especially projecting its future evolution has encouraged scientists to explore the dynamical, physical, and biogeochemical processes in the ocean. Understanding the role of these processes in the climate system is an interesting and challenging scientific subject. For example, a research question how much extra heat or CO2 generated by anthropogenic activities can be stored in the deep ocean is not only scientifically interesting but also important in projecting future climate of the earth. Thus, OGCMs have been developed and applied to investigate the various oceanic processes and their role in the climate system.

  11. Trypanosoma cruzi: circulating antigens

    V. Bongertz


    Full Text Available Circulating antigens were detected in sera of mice experimentally infected with a high close of Trypanosoma cruzi by reaction with sera from chronically infected mice. The immunodiffusion reaction between homologous acute and chronic sera produced four precipitation lines. By reaction with chronic mouse serum, circulating antingens were detected in sera from heavily infected hamsters, dogs, rabbits and in sera from chagasic patients. A reaction was also found in urine from acutely infected mice and dogs. Trypanosoma cruzi exoantigen was detected in trypanosome culture medium and in the supernatant of infected cell cultures. Attempts to isolate the antigens are described.Antígenos circulantes foram detectados em soros de camundongos infectados experimentalmente com elevadas doses de Trypanosoma cruzi pela reação com soros obtidos de camundongos em fase crônica de infecção. A reação de imunodifusão entre soros homólogos agudo e crônico produziu quatro linhas de precipitação. Por reação com soro crônico de camundongo antígenos circulantes foram detectados em soros de crícetos, cães e coelhos infectados com doses elevadas de Trypanosoma cruzi e em soros de pacientes chagásicos. Uma reação foi também observada com urina de camundongos e cães infectados de forma aguda. Exoantígeno de Trypanosoma cruzi foi detectado em meio de cultura de tripanosomas e em sobrenadantes de culturas de células infectadas. Tentativas de isolamento dos antigenos são descritas.

  12. TROPICAL METEOROLOGY & Climate: Hadley Circulation

    Lu, Jian; Vecchi, Gabriel A.


    The Hadley circulation, a prominent circulation feature characterized by rising air near the Equator and sinking air in the subtropics, defines the position of dry subtropical areas and is a fundamental regulator of the earth’s energy and momentum budgets. The character of the Hadley circulation, and its related precipitation regimes, exhibits variation and change in response to both climate variability and radiative forcing changes. The strength and position of the Hadley circulation change from year to year paced by El Niño and La Niña events. Over the last few decades of the twentieth century, the Hadley cell has expanded poleward in both hemispheres, with changes in atmospheric composition (including stratospheric ozone depletion and greenhouse gas increases) thought to have contributed to its expansion. This article introduces the basic phenomenology and driving mechanism of the Hadley circulation and discusses its variations under both natural and anthropogenic climate forcings.

  13. Sino-Danish Brain Circulation

    Bertelsen, Rasmus Gjedssø; Du, Xiangyun; Søndergaard, Morten Karnøe


    China is faced with urgent needs to develop an economically and environmentally sustainable economy based on innovation and knowledge. Brain circulation and research and business investments from the outside are central for this development. Sino-American brain circulation and research...... and investment by overseas researchers and entrepreneurs are well described. In that case, the US is the center of global R&D and S&T. However, the brain circulation and research and investments between a small open Scandinavian economy, such as Denmark, and the huge developing economy of China are not well...... understood. In this case, Denmark is very highly developed, but a satellite in the global R&D and S&T system. With time and the growth of China as a R&D and S&T power house, both Denmark and China will benefit from brain circulation between them. Such brain circulation is likely to play a key role in flows...

  14. Natural Circulation with Boiling

    A number of parameters with dominant influence on the power level at hydrodynamic instability in natural circulation, two-phase flow, have been studied experimentally. The geometrical dependent quantities were: the system driving head, the boiling channel and riser dimensions, the single-phase as well as the two phase flow restrictions. The parameters influencing the liquid properties were the system pressure and the test section inlet subcooling. The threshold of instability was determined by plotting the noise characteristics in the mass flow records against power. The flow responses to artificially obtained power disturbances at instability conditions were also measured in order to study the nature of hydrodynamic instability. The results presented give a review over relatively wide ranges of the main parameters, mainly concerning the coolant performance in both single and parallel boiling channel flow. With regard to the power limits the experimental results verified that the single boiling channel performance was intimately related to that of the parallel channels. In the latter case the additional inter-channel factors with attenuating effects were studied. Some optimum values of the parameters were observed

  15. Assisted Ventilation.

    Dries, David J


    Controlled Mechanical Ventilation may be essential in the setting of severe respiratory failure but consequences to the patient including increased use of sedation and neuromuscular blockade may contribute to delirium, atelectasis, and diaphragm dysfunction. Assisted ventilation allows spontaneous breathing activity to restore physiological displacement of the diaphragm and recruit better perfused lung regions. Pressure Support Ventilation is the most frequently used mode of assisted mechanical ventilation. However, this mode continues to provide a monotonous pattern of support for respiration which is normally a dynamic process. Noisy Pressure Support Ventilation where tidal volume is varied randomly by the ventilator may improve ventilation and perfusion matching but the degree of support is still determined by the ventilator. Two more recent modes of ventilation, Proportional Assist Ventilation and Neurally Adjusted Ventilatory Assist (NAVA), allow patient determination of the pattern and depth of ventilation. Proposed advantages of Proportional Assist Ventilation and NAVA include decrease in patient ventilator asynchrony and improved adaptation of ventilator support to changing patient demand. Work of breathing can be normalized with these modes as well. To date, however, a clear pattern of clinical benefit has not been demonstrated. Existing challenges for both of the newer assist modes include monitoring patients with dynamic hyperinflation (auto-positive end expiratory pressure), obstructive lung disease, and air leaks in the ventilator system. NAVA is dependent on consistent transduction of diaphragm activity by an electrode system placed in the esophagus. Longevity of effective support with this technique is unclear. PMID:25501776

  16. Containment air circulation for optimal hydrogen recombination

    An accepted first-line defense for hydrogen mitigation is to design for the hydrogen to be rapidly mixed with the containment atmosphere and diluted to below flammability concentrations. Then, as hydrogen continues to be produced in the longer term, recombiners can be used to remove hydrogen: recombiners can be located in forced-air ducts or passive recombiners can be distributed within containment and the heat of recombination used to promote local air circulation. However, this principle does not eliminate the possibility of high hydrogen concentrations at locations removed from the recombiners. An improvement on this strategy is to arrange for a specific, buoyancy-driven, overall circulation of the containment atmosphere such that the recombiners can be located within the recirculation flow, immediately downstream of the hydrogen source. This would make the mixing process more predictable and solve the mass-transfer problem associated with distributed recombiners. Ideally, the recombiners would be located just above the hydrogen source so that the heat of recombination would assist the overall circulation. In this way, the hydrogen would be removed as close as possible to the source, thereby minimizing the amount of hydrogen immediately downstream of the source and reducing the hydrogen concentration to acceptable levels at other locations. Such a strategy requires the containment volume to be divided into an upflow path, past the hydrogen source and the recombiner, and a downflow path to complete the circuit. The flow could be generated actively using fans or passively using buoyancy forces arising from the difference in density of gases in the upfiow and downflow paths; the gases in the downflow path being cooled at an elevated heat sink. (author)

  17. The circulation physiology of agroecosystems

    Cao Zhiping; Richard Dawson


    This paper represents an effort to enlarge the understanding of the biophysical foundation of agroecosystems by using an analogy with the circulation of the blood in the human body. The circulation function in the human body can be represented as arterial pressure. The factors affecting arterial pressure in the human body have direct counterparts in the cultivation-husbandry system. The relationship between circulation pressure and the factors affecting that pressure in the cultivation-husbandry system are similar to the relationship between the arterial pressure and factors affecting arterial pressure in the human body. Furthermore, circulation resistance in the cultivation-husbandry system can be shown to be analogous to the calculation of peripheral resistance in the human body by Poiseuille's formula.

  18. Hearing Assistive Technology

    ... for the Public / Hearing and Balance Hearing Assistive Technology Hearing Assistive Technology: FM Systems | Infrared Systems | Induction ... Assistive Technology Systems Solutions What are hearing assistive technology systems (HATS)? Hearing assistive technology systems (HATS) are ...

  19. Atmospheric Circulation of Terrestrial Exoplanets

    Showman, Adam P.; Wordsworth, Robin D.; Merlis, Timothy M.; Kaspi, Yohai


    The investigation of planets around other stars began with the study of gas giants, but is now extending to the discovery and characterization of super-Earths and terrestrial planets. Motivated by this observational tide, we survey the basic dynamical principles governing the atmospheric circulation of terrestrial exoplanets, and discuss the interaction of their circulation with the hydrological cycle and global-scale climate feedbacks. Terrestrial exoplanets occupy a wide range of physical a...

  20. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    Yao, Fengchao


    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented by 1980, and the climatological mean are analyzed using model output to delineate the three-dimensional structure and to investigate the underlying dynamical mechanisms. The horizontal model circulation in the winter of 1980 is dominated by energetic eddies. The climatological model mean results suggest that the surface inflow intensifies in a western boundary current in the southern Red Sea that switches to an eastern boundary current north of 24N. The overturning is accomplished through a cyclonic recirculation and a cross-basin overturning circulation in the northern Red Sea, with major sinking occurring along a narrow band of width about 20 km along the eastern boundary and weaker upwelling along the western boundary. The northward pressure gradient force, strong vertical mixing, and horizontal mixing near the boundary are the essential dynamical components in the model\\'s winter overturning circulation. The simulated water exchange is not hydraulically controlled in the Strait of Bab el Mandeb; instead, the exchange is limited by bottom and lateral boundary friction and, to a lesser extent, by interfacial friction due to the vertical viscosity at the interface between the inflow and the outflow. Key Points Sinking occurs in a narrow boundary layer along the eastern boundary Surface western boundary current switches into an eastern boundary current Water exchange in the Strait of Bab el Mandeb is not hydraulically controlled © 2014. American Geophysical Union. All Rights Reserved.

  1. The Invertibility, Explicit Determinants, and Inverses of Circulant and Left Circulant and g-Circulant Matrices Involving Any Continuous Fibonacci and Lucas Numbers

    Zhaolin Jiang


    Full Text Available Circulant matrices play an important role in solving delay differential equations. In this paper, circulant type matrices including the circulant and left circulant and g-circulant matrices with any continuous Fibonacci and Lucas numbers are considered. Firstly, the invertibility of the circulant matrix is discussed and the explicit determinant and the inverse matrices by constructing the transformation matrices are presented. Furthermore, the invertibility of the left circulant and g-circulant matrices is also studied. We obtain the explicit determinants and the inverse matrices of the left circulant and g-circulant matrices by utilizing the relationship between left circulant, g-circulant matrices and circulant matrix, respectively.

  2. Circulating Fibronectin Controls Tumor Growth

    Anja von Au


    Full Text Available Fibronectin is ubiquitously expressed in the extracellular matrix, and experimental evidence has shown that it modulates blood vessel formation. The relative contribution of local and circulating fibronectin to blood vessel formation in vivo remains unknown despite evidence for unexpected roles of circulating fibronectin in various diseases. Using transgenic mouse models, we established that circulating fibronectin facilitates the growth of bone metastases by enhancing blood vessel formation and maturation. This effect is more relevant than that of fibronectin produced by endothelial cells and pericytes, which only exert a small additive effect on vessel maturation. Circulating fibronectin enhances its local production in tumors through a positive feedback loop and increases the amount of vascular endothelial growth factor (VEGF retained in the matrix. Both fibronectin and VEGF then cooperate to stimulate blood vessel formation. Fibronectin content in the tumor correlates with the number of blood vessels and tumor growth in the mouse models. Consistent with these results, examination of three separate arrays from patients with breast and prostate cancers revealed that a high staining intensity for fibronectin in tumors is associated with increased mortality. These results establish that circulating fibronectin modulates blood vessel formation and tumor growth by modifying the amount of and the response to VEGF. Furthermore, determination of the fibronectin content can serve as a prognostic biomarker for breast and prostate cancers and possibly other cancers.

  3. Foreign assistance

    This paper reports that providing energy assistance to developing countries remains a relatively low priority of the Agency for International Development. AID is helping some developing countries meet their energy needs, but this assistance varies substantially because of the agency's decentralized structure. Most AID energy funding has gone to a handful of countries-primarily Egypt and Pakistan. With limited funding in most other countries, AID concentrates on providing technical expertise and promoting energy policy reforms that will encourage both energy efficiency and leverage investment by the private sector and other donors. Although a 1989 congressional directive to pursue a global warming initiative has had a marginal impact on the agency's energy programming, many AID energy programs, including those directed at energy conservation, help address global warming concerns

  4. Atmospheric Circulation of Terrestrial Exoplanets

    Showman, Adam P; Merlis, Timothy M; Kaspi, Yohai


    The investigation of planets around other stars began with the study of gas giants, but is now extending to the discovery and characterization of super-Earths and terrestrial planets. Motivated by this observational tide, we survey the basic dynamical principles governing the atmospheric circulation of terrestrial exoplanets, and discuss the interaction of their circulation with the hydrological cycle and global-scale climate feedbacks. Terrestrial exoplanets occupy a wide range of physical and dynamical conditions, only a small fraction of which have yet been explored in detail. Our approach is to lay out the fundamental dynamical principles governing the atmospheric circulation on terrestrial planets--broadly defined--and show how they can provide a foundation for understanding the atmospheric behavior of these worlds. We first survey basic atmospheric dynamics, including the role of geostrophy, baroclinic instabilities, and jets in the strongly rotating regime (the "extratropics") and the role of the Hadle...

  5. VanderLaan Circulant Type Matrices

    Hongyan Pan


    Full Text Available Circulant matrices have become a satisfactory tools in control methods for modern complex systems. In the paper, VanderLaan circulant type matrices are presented, which include VanderLaan circulant, left circulant, and g-circulant matrices. The nonsingularity of these special matrices is discussed by the surprising properties of VanderLaan numbers. The exact determinants of VanderLaan circulant type matrices are given by structuring transformation matrices, determinants of well-known tridiagonal matrices, and tridiagonal-like matrices. The explicit inverse matrices of these special matrices are obtained by structuring transformation matrices, inverses of known tridiagonal matrices, and quasi-tridiagonal matrices. Three kinds of norms and lower bound for the spread of VanderLaan circulant and left circulant matrix are given separately. And we gain the spectral norm of VanderLaan g-circulant matrix.

  6. Conservation of Circulation in Magnetohydrodynamics

    Bekenstein, J D; Bekenstein, Jacob D.; Oron, Asaf


    We demonstrate, both at the Newtonian and (general) relativistic levels, theexistence of a generalization of Kelvin's circulation theorem (for pure fluids)which is applicable to perfect magnetohydrodynamics. The argument is based onthe least action principle for magnetohydrodynamic flow. Examples of the newconservation law are furnished. The new theorem should be helpful inidentifying new kinds of vortex phenomena distinct from magnetic ropes or fluidvortices.

  7. Neural Control of the Circulation

    Thomas, Gail D.


    The purpose of this brief review is to highlight key concepts about the neural control of the circulation that graduate and medical students should be expected to incorporate into their general knowledge of human physiology. The focus is largely on the sympathetic nerves, which have a dominant role in cardiovascular control due to their effects to…

  8. Selected translated abstracts of Russian-language climate-change publications. 4: General circulation models

    Burtis, M.D. [comp.] [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; Razuvaev, V.N.; Sivachok, S.G. [All-Russian Research Inst. of Hydrometeorological Information--World Data Center, Obninsk (Russian Federation)


    This report presents English-translated abstracts of important Russian-language literature concerning general circulation models as they relate to climate change. Into addition to the bibliographic citations and abstracts translated into English, this report presents the original citations and abstracts in Russian. Author and title indexes are included to assist the reader in locating abstracts of particular interest.

  9. Journalism as Cultures of Circulation

    Bødker, Henrik


    The universe of journalism has always consisted of interspersed texts, meanings and practices. Yet, much journalism research has often isolated either texts and/or contexts and as such assumed relations between professional practices, informed (rational) readers and (conceived) core texts...... of journalism. It is, however, more important than ever to shift attention away from texts to the processes through which they are circulated. This is partly because the many cultural forms of journalism (textual, institutional, technological, material, behavioural and imagined) are undergoing significant......, likes, comments, searches, journalist roles, writing and reading positions and identities etc. Such forms will be traced within the mediation of a specific event with the overall aim of beginning a theorization of the landscape of journalism as highly interrelated cultures of circulation....

  10. Proper Sizing of Circulation Pumps

    Tommerup, Henrik M.; Nørgaard, Jørgen


    The paper describes the preliminary results from field tests of replacing various types of old pumps used for circulating water in heating systems in single- and double-family houses with new types of pumps. The tests were carried out in Denmark for the Danish Electricity Savings Trust, but the...... results can be applied to Europe in general. Despite the small sample of houses involved in the test, 15 houses, some rather safe conclusions can be drawn from the results, which showed that newly developed pumps with power consumption around 5-8 W, can perform the task of circulating the water...... sufficiently to keep the houses satisfactorily warm during the heating season of the test. The old replaced pumps used 5-10 times more power. In Europe alone, a gradual replacement of the present vastly oversized pumps with such small but sufficient pumps can save the construction of 17 large power plants as...

  11. Radioisotopic evaluation of portal circulation

    The use of a radio-tracer of portal circulation through the intestine, should prevent cruel punctures in the portal-vein or spleen as it is usually the case with traditional methods in the study of portal-system. The absorption of I-131 and Tc-99m, previously cheked in rabbits presented similar results in dogs. The time of circulation between terminal large-intestine and the liver (t-RF) was determined by external counting at hepatic level by recording radioactivity variation-time. In healthy animals the t-RF was from 20to 60 seconds, with average time of 42 seconds. In 2 animals with partial binding of portal-vein the t-RF went up to 110 and 120 seconds. (Author)

  12. Ocean circulation generated magnetic signals

    Manoj, C.; Kuvshinov, A.; Maus, S.;


    Conducting ocean water, as it flows through the Earth's magnetic field, generates secondary electric and magnetic fields. An assessment of the ocean-generated magnetic fields and their detectability may be of importance for geomagnetism and oceanography. Motivated by the clear identification of...... ocean tidal signatures in the CHAMP magnetic field data we estimate the ocean magnetic signals of steady flow using a global 3-D EM numerical solution. The required velocity data are from the ECCO ocean circulation experiment and alternatively from the OCCAM model for higher resolution. We assume an...... magnetic field, as compared to the ECCO simulation. Besides the expected signatures of the global circulation patterns, we find significant seasonal variability of ocean magnetic signals in the Indian and Western Pacific Oceans. Compared to seasonal variation, interannual variations produce weaker signals....

  13. The Sun's Shallow Meridional Circulation

    Hathaway, David H


    The Sun's global meridional circulation is evident as a slow poleward flow at its surface. This flow is observed to carry magnetic elements poleward - producing the Sun's polar magnetic fields as a key part of the 11-year sunspot cycle. Current theories for the sunspot cycle assume that this surface flow is part of a circulation which sinks inward at the poles and turns equatorward at depths below 100 Mm. Here we use the advection of the Sun's convection cells by the meridional flow to map the flow velocity in latitude and depth. Our measurements show the largest cells clearly moving equatorward at depths below 35 Mm - the base of the Sun's surface shear layer. This surprisingly shallow return flow indicates the need for substantial revisions to solar/stellar dynamo theory.

  14. Natural circulation systems: advantages and challenges

    This lecture briefly explains the principle of working of a natural circulation system, its various advantages and applications in nuclear and other industries. The major challenges to be overcome before the wide acceptance of natural circulation as the normal mode of coolant circulation in nuclear power reactors are briefly described. Classification of NCSs and the terminologies commonly encountered in natural circulation literature are also briefly explained. (author)

  15. The general circulation of the atmosphere

    Schneider, Tapio


    Theories of how Earth's surface climate may change in the future, of how it may have been in the past, and of how it is related to climates of other planets must build upon a theory of the general circulation of the atmosphere. The view of the atmospheric general circulation presented here focuses not on Earth's general circulation as such but on a continuum of idealized circulations with axisymmetric flow statistics. Analyses of observational data for Earth's atmosphere, simulations with ide...

  16. Conservation of circulation in magnetohydrodynamics

    Bekenstein; Oron


    We demonstrate at both the Newtonian and (general) relativistic levels the existence of a generalization of Kelvin's circulation theorem (for pure fluids) that is applicable to perfect magnetohydrodynamics. The argument is based on the least action principle for magnetohydrodynamic flow. Examples of the new conservation law are furnished. The new theorem should be helpful in identifying new kinds of vortex phenomena distinct from magnetic ropes or fluid vortices. PMID:11089118

  17. Electronic circulation of accounting documents

    Kremláčková, Kateřina


    This thesis describes a circulation of accounting documents in an accounting entity, deals with legal requirements of the entire process and discusses it as a part of an internal control system of the entity. In connection with the theme of the work there are also defined legislative conditions for using information and communication technologies and introduced possibilities of involving these technologies in the process of processing of the accounting documents. Above all the electronic data...

  18. Purchase, circulation and fuel taxation

    Potter, Stephen


    During the last decade, the UK and many other developed nations have reformed existing forms of road transport taxation to address a number of transport policy goals. This has involved modifying the design of purchase, circulation and fuel taxation to promote: • More fuel efficient vehicles • Alternative fuel vehicles • Cleaner fuels (lower emissions and/or low carbon) • Modal shift and traffic volume • Congestion reduction This chapter particularly explores the use of...

  19. Examples of natural circulation in PHWR

    The main objective of this lecture is to provide deep insight into the complex natural circulation phenomena in the core of a Pressurised Heavy Water Reactor. A detailed account of natural circulation tests conducted in an Indian PHWR is given in this lecture. This will enable the participants to appreciate the importance of natural circulation in a nuclear reactor to a greater extent. (author)

  20. Physician-assisted death.

    Senn, John S.


    Physician-assisted death includes both euthanasia and assistance in suicide. The CMA urges its members to adhere to the principles of palliative care. It does not support euthanasia and assisted suicide. The following policy summary includes definitions of euthanasia and assisted suicide, background information, basic ethical principles and physician concerns about legalization of physician-assisted death.

  1. Circulating follistatin in relation to energy metabolism.

    Hansen, Jakob Schiøler; Plomgaard, Peter


    Recently, substantial evidence has emerged that the liver contributes significantly to the circulating levels of follistatin and that circulating follistatin is tightly regulated by the glucagon-to-insulin ratio. Both observations are based on investigations of healthy subjects. These novel findings challenge the present view of circulating follistatin in human physiology, being that circulating follistatin is a result of spill-over from para/autocrine actions in various tissues and cells. Follistatin as a liver-derived protein under the regulation of glucagon-to-insulin ratio suggests a relation to energy metabolism. In this narrative review, we attempt to reconcile the existing findings on circulating follistatin with the novel concept that circulating follistatin is a liver-derived molecule regulated by the glucagon-to-insulin ratio. The picture emerging is that conditions associated with elevated levels of circulating follistatin have a metabolic denominator with decreased insulin sensitivity and/or hyperglucagoneimia. PMID:27264073

  2. Intestinal circulation during inhalation anesthesia

    This study was designed to evaluate the influence of inhalational agents on the intestinal circulation in an isolated loop preparation. Sixty dogs were studied, using three intestinal segments from each dog. Selected intestinal segments were pumped with aortic blood at a constant pressure of 100 mmHg. A mixture of 86Rb and 9-microns spheres labeled with 141Ce was injected into the arterial cannula supplying the intestinal loop, while mesenteric venous blood was collected for activity counting. A very strong and significant correlation was found between rubidium clearance and microsphere entrapment (r = 0.97, P less than 0.0001). Nitrous oxide anesthesia was accompanied by a higher vascular resistance (VR), lower flow (F), rubidium clearance (Cl-Rb), and microspheres entrapment (Cl-Sph) than pentobarbital anesthesia, indicating that the vascular bed in the intestinal segment was constricted and flow (total and nutritive) decreased. Halothane, enflurane, and isoflurane anesthesia were accompanied by a much lower arteriovenous oxygen content difference (AVDO2) and oxygen uptake than pentobarbital or nitrous oxide. Compared with pentobarbital, enflurane anesthesia was not accompanied by marked differences in VR, F, Cl-Rb, and Cl-Sph; halothane at 2 MAC decreased VR and increased F and Cl-Rb while isoflurane increased VR and decreased F. alpha-Adrenoceptor blockade with phentolamine (1 mg . kg-1) abolished isoflurane-induced vasoconstriction, suggesting that the increase in VR was mediated via circulating catecholamines

  3. A blood circulation model for reference man

    Leggett, R.W.; Eckerman, K.F. [Oak Ridge National Lab., TN (United States). Health Sciences Research Div.; Williams, L.R. [Indiana Univ., South Bend, IN (United States). Div. of Liberal Arts and Sciences


    This paper describes a dynamic blood circulation model that predicts the movement and gradual dispersal of a bolus of material in the circulation after its intravascular injection into an adult human. The main purpose of the model is to improve the dosimetry of internally deposited radionuclides that decay in the circulation to a significant extent. The total blood volume is partitioned into the blood contents of 24 separate organs or tissues, right heart chambers, left heart chambers, pulmonary circulation, arterial outflow to the systemic tissues (aorta and large arteries), and venous return from the systemic tissues (large veins). As a compromise between physical reality and computational simplicity, the circulation of blood is viewed as a system of first-order transfers between blood pools, with the delay time depending on the mean transit time across the pool. The model allows consideration of incomplete, tissue-dependent extraction of material during passage through the circulation and return of material from tissues to plasma.

  4. Circulation of Venus upper mesosphere.

    Zasova, Ludmila; Gorinov, Dmitry; Shakun, Alexey; Altieri, Francesca; Migliorini, Alessandra; Piccioni, Giuseppe; Drossart, Pierre


    Observation of the O2 1.27 μm airglow intensity distribution on the night side of Venus is one of the methods of study of the circulation in upper mesosphere 90-100 km. VIRTIS-M on board Venus Express made these observations in nadir and limb modes in Southern and Northern hemispheres respectively. Global map of the O2 night glow is published (Piccioni et al. 2009). In this work we use for analysis only data, obtained with exposure > 3 s to avoid high noisy data. It was found that intensity of emission decreases to poles and to terminators (similar to Piccioni et al.2009) in both hemispheres, which gives evidence for existence of SS-AS circulation with transport of the air masses through poles and terminators with ascending/descending flows at SS/AS areas. However, asymmetry of distribution of intensity of airglow is observed in both hemispheres. Global map for southern hemisphere (from nadir data) has good statistics at φ > 10-20° S and pretty poor at low latitude. Maximum emission is shifted from midnight by 1 - 2 hours to the evening (22-23h) and deep minimum of emission is found at LT=2-4 h at φ > 20° S. This asymmetry is extended up to equatorial region, however statistic is poor there. No evident indication for existence of the Retrograde Zonal Superrotation (RZS) is found: maximum emission in this case, which is resulting from downwards flow, should be shifted to the morning. The thermal tides, gravity waves are evidently influence on the night airglow distribution. VIRTIS limb observations cover the low northern latitudes and they are more sparse at higher latitudes. Intensity of airglow at φ = 0 - 20° N shows wide maximum, which is shifted by 1- 2 h from midnight to morning terminator. This obviously indicates that observed O2 night glow distribution in low North latitudes is explained by a superposition of SS-AS flow and RZS circulation at 95-100 km. This behavior is similar to the NO intensity distribution, obtained by SPICAV.

  5. A reliable method to concentrate circulating DNA.

    Bryzgunova, Olga; Bondar, Anna; Morozkin, Evgeniy; Mileyko, Vladislav; Vlassov, Valentin; Laktionov, Pavel


    Concentration of circulating DNA probes is required to increase the amount of DNA involved in subsequent study (by polymerase chain reaction, sequencing, and microarray). This work was dedicated to the comparison of five different methods used for concentration of DNA circulating in blood. Precipitation of circulating DNA with acetone in the presence of triethylamine provides minimal DNA loss, high reproducibility, and at least three times higher DNA yield in comparison with the standard ethanol protocol. PMID:20828533

  6. Space-Time Radar Waveforms: Circulating Codes

    Babur, G.; Aubry, P.; Le Chevalier, F.


    This paper describes a concept of the circulating codes covering the whole class of the space-time codes. The circulating codes do not narrow the radiated pattern of the antenna array, thus providing a wide angular coverage, possibly tunable. In turn, the beam-forming on transmit is achievable by means of the signal processing in one (or each) receiver channel. The modelling results demonstrate the efficiency of the circulating codes based on their multidimensional ambiguity functions.

  7. Linear thermal circulator based on Coriolis forces.

    Li, Huanan; Kottos, Tsampikos


    We show that the presence of a Coriolis force in a rotating linear lattice imposes a nonreciprocal propagation of the phononic heat carriers. Using this effect we propose the concept of Coriolis linear thermal circulator which can control the circulation of a heat current. A simple model of three coupled harmonic masses on a rotating platform permits us to demonstrate giant circulating rectification effects for moderate values of the angular velocities of the platform. PMID:25768443

  8. The Ten Relationships in Rural Land Circulation

    Cai, Zhirong; Ren, Shuo; Zhang, Zhigang


    The ten relationships during land circulation are discussed. Among them, the relationship between peasant household and government indicates that government should only carry out its service and regulatory functions and farmers should be the main body of land circulation, because peasants usually have no discourse power during land circulation. In the relationship between land ownership and contracting management right, we mainly discuss the transfer of land contracting management right and p...

  9. Role of Circulating Fibrocytes in Cardiac Fibrosis

    Lin, Rong-Jie; Su, Zi-Zhuo; Liang, Shu-Min; Chen, Yu-Yang; Shu, Xiao-Rong; Nie, Ru-Qiong; Wang, Jing-Feng; Xie, Shuang-Lun


    Objective: It is revealed that circulating fibrocytes are elevated in patients/animals with cardiac fibrosis, and this review aims to provide an introduction to circulating fibrocytes and their role in cardiac fibrosis. Data Sources: This review is based on the data from 1994 to present obtained from PubMed. The search terms were “circulating fibrocytes” and “cardiac fibrosis”. Study Selection: Articles and critical reviews, which are related to circulating fibrocytes and cardiac fibrosis, were selected. Results: Circulating fibrocytes, which are derived from hematopoietic stem cells, represent a subset of peripheral blood mononuclear cells exhibiting mixed morphological and molecular characteristics of hematopoietic and mesenchymal cells (CD34+/CD45+/collagen I+). They can produce extracellular matrix and many cytokines. It is shown that circulating fibrocytes participate in many fibrotic diseases, including cardiac fibrosis. Evidence accumulated in recent years shows that aging individuals and patients with hypertension, heart failure, coronary heart disease, and atrial fibrillation have more circulating fibrocytes in peripheral blood and/or heart tissue, and this elevation of circulating fibrocytes is correlated with the degree of fibrosis in the hearts. Conclusions: Circulating fibrocytes are effector cells in cardiac fibrosis. PMID:26831236

  10. Improvement of Classification of Enterprise Circulating Funds

    Rohanova Hanna O.


    Full Text Available The goal of the article lies in revelation of possibilities of increase of efficiency of managing enterprise circulating funds by means of improvement of their classification features. Having analysed approaches of many economists to classification of enterprise circulating funds, systemised and supplementing them, the article offers grouping classification features of enterprise circulating funds. In the result of the study the article offers an expanded classification of circulating funds, which clearly shows the role of circulating funds in managing enterprise finance and economy in general. The article supplements and groups classification features of enterprise circulating funds by: the organisation level, functioning character, sources of formation and their cost, and level of management efficiency. The article shows that the provided grouping of classification features of circulating funds allows exerting all-sided and purposeful influence upon indicators of efficiency of circulating funds functioning and facilitates their rational management in general. The prospect of further studies in this direction is identification of the level of attraction of loan resources by production enterprises for financing circulating funds.

  11. A blood circulation model for reference man

    A dynamic blood circulation model that predicts the movement and gradual dispersion of a bolus of material in the circulation after its intravenous injection into an adult human. The main purpose of the model is improve the dosimetry of internally deposited radionuclides that decay in the circulation to a significant extent. The model partitions the blood volume into 24 separate organs or tissues, right heart chamber, left heart chamber, pulmonary circulation, arterial outflow to the aorta and large arteries, and venous return via the large veins. Model results were compared to data obtained from injection of carbon 11 labeled carbon monoxide or rubidium 86

  12. Irregular Labellings of Circulant Graphs

    Anholcer, Marcin


    We investigate the \\textit{irregularity strength} ($s(G)$) and \\textit{total vertex irregularity strength} ($tvs(G)$) of circulant graphs $Ci_n(1,2,...,k)$ and prove that $tvs(Ci_n(1,2,...,k))=\\lceil\\frac{n+2k}{2k+1}\\rceil$, while $s(Ci_n(1,2,...,k))=\\lceil\\frac{n+2k-1}{2k}\\rceil$ except the case when $(n \\bmod 4k = 2k+1 \\wedge k\\bmod 2=1) \\vee n=2k+1$ and $s(Ci_n(1,2,...,k))=\\lceil\\frac{n+2k-1}{2k}\\rceil+1$.

  13. Inflammatory response and extracorporeal circulation.

    Kraft, Florian; Schmidt, Christoph; Van Aken, Hugo; Zarbock, Alexander


    Patients undergoing cardiac surgery with extracorporeal circulation (EC) frequently develop a systemic inflammatory response syndrome. Surgical trauma, ischaemia-reperfusion injury, endotoxaemia and blood contact to nonendothelial circuit compounds promote the activation of coagulation pathways, complement factors and a cellular immune response. This review discusses the multiple pathways leading to endothelial cell activation, neutrophil recruitment and production of reactive oxygen species and nitric oxide. All these factors may induce cellular damage and subsequent organ injury. Multiple organ dysfunction after cardiac surgery with EC is associated with an increased morbidity and mortality. In addition to the pathogenesis of organ dysfunction after EC, this review deals with different therapeutic interventions aiming to alleviate the inflammatory response and consequently multiple organ dysfunction after cardiac surgery. PMID:26060024

  14. The aerodynamics of circulation control

    Wood, N. J.


    Two dimensional subsonic wind tunnel tests were conducted on a 20% thickness: chord ratio circulation controlled elliptic aerofoil section equipped with forward and reverse blowing slots. Overall performance measurements were made over a range of trailing edge blowing momentum coefficients from 0 to 0.04; some included the effect of leading edge blowing. A detailed investigation of the trailing edge wall jet, using split film probes, hot wire probes and total head tubes, provided measurements of mean velocity components, Reynolds normal and shear stresses, and radial static pressure. The closure of the two dimensional angular momentum and continuity equations was examined using the measured data, with and without correction, and the difficulty of obtaining a satisfactory solution illustrated. Suggestions regarding the nature of the flow field which should aid the understanding of Coanda effect and the theoretical solution of highly curved wall jet flows are presented.

  15. Unit group of algebra of circulant matrices

    Rajendra Sharma


    Full Text Available Let Crn(Fp denote the algebra of nXn circulant matrices over Fp, finite field of order p of prime characteristic p. The order of the unit groups U(Cr3(Fp, U(Cr4(Fp and U(Cr5(Fp of algebras of circulant matrices over Fp are characterized.

  16. Introduction to instabilities in natural circulation systems

    This lecture reviews the various natural circulation instabilities and their classification instabilities observed during various stages of natural circulation such as single-phase, boiling inception and fully developed two-phase flow are described. The mechanisms causing the instabilities are also briefly described. (author)

  17. Kelvin's Canonical Circulation Theorem in Hall Magnetohydrodynamics

    Shivamoggi, B K


    The purpose of this paper is to show that, thanks to the restoration of the legitimate connection between the current density and the plasma flow velocity in Hall magnetohydrodynamics (MHD), Kelvin's Circulation Theorem becomes valid in Hall MHD. The ion-flow velocity in the usual circulation integral is now replaced by the canonical ion-flow velocity.

  18. Numerical Modeling of Ocean Circulation

    Miller, Robert N.


    The modelling of ocean circulation is important not only for its own sake, but also in terms of the prediction of weather patterns and the effects of climate change. This book introduces the basic computational techniques necessary for all models of the ocean and atmosphere, and the conditions they must satisfy. It describes the workings of ocean models, the problems that must be solved in their construction, and how to evaluate computational results. Major emphasis is placed on examining ocean models critically, and determining what they do well and what they do poorly. Numerical analysis is introduced as needed, and exercises are included to illustrate major points. Developed from notes for a course taught in physical oceanography at the College of Oceanic and Atmospheric Sciences at Oregon State University, this book is ideal for graduate students of oceanography, geophysics, climatology and atmospheric science, and researchers in oceanography and atmospheric science. Features examples and critical examination of ocean modelling and results Demonstrates the strengths and weaknesses of different approaches Includes exercises to illustrate major points and supplement mathematical and physical details

  19. Assisted Living Community Profile

    ... for the Seniors Housing & Care Industry, reflects NCAL's philosophy of assisted living. 2 Data also from the ... Assisted Living Studies Clinical Practice Guidelines Health Information Technology In-Service Training Tools Periodicals State Regulatory Review ...

  20. Assisted Vaginal Delivery

    ... having a repeat assisted vaginal delivery in a future pregnancy? If you have had one assisted vaginal ... Education Green Journal Practice Management Coding Health Info Technology Professional Liability Managing Your Practice Patient Safety & Quality ...


    US Agency for International Development — provides a view of U.S. Government foreign assistance funds across agencies and enables users to explore, analyze, and review aid investments...

  2. Assisted Reproductive Technology (ART)

    ... Information Clinical Trials Resources and Publications Assisted Reproductive Technology (ART) Skip sharing on social media links Share ... American Society for Reproductive Medicine. (2012). Assisted reproductive technologies: A guide for patients . Retrieved June 11, 2012, ...

  3. Advances in Research on Circulating Tumor Cells in Lung Cancer

    Yingjian SONG


    Full Text Available Metastatic and recurrent tumors have been identified as the leading attribute to the lung cancer deaths. Cancer research has demonstrated the critical role circulating tumor cells (CTCs play in the metastatic spread of carcinomas and the recurrence of lung cancer. The rapid advancement of technology in targeted therapy resolves the embarrassing situation for those late-stage patients whose tumor tissues cannot be obtained. CTCs, as a substitute for the tumor tissues, represent a decisive tool to the cancer treatment strategy. Thus, CTCs exert a fundamental role in the early detection of micro-metastasis, assisting in diagnosis, prognosis and monitoring of the recurrent tumors, and subsequently choosing an individualized approach for the therapeutic treatment. This article will review the advances, which have been made in the research area of CTCs with the aid of its applications in cancer therapy.

  4. Interannual variability of the Adriatic Sea circulation

    Beg Paklar, Gordana; Sepic, Jadranka; Grbec, Branka; Dzoic, Tomislav; Kovac, Zarko; Ivatek-Sahdan, Stjepan


    The Regional Ocean Modeling System (ROMS) was implemented in order to reproduce interannual variability of the Adriatic Sea circulation. Simulations and model result analysis were performed for a three-year period from 1st January 2011 to 31st December 2013. ROMS model run was forced with realistic atmospheric fields obtained from meteorological model Aladin, climatological river discharges, tides and Mediterranean circulation imposed at the southern open boundary. Atmospheric forcing included momentum, heat and water fluxes calculated interactively from the Aladin surface fields during ROMS model simulations. Model results were compared with available CTD and ADCP measurements and discussed in the light of the climatological circulation and thermohaline properties of the Adriatic Sea and its coastal areas. Interannual variability in the Adriatic circulation is related to the prevailing atmospheric conditions, changes in the hydrological conditions and water mass exchange at the Otranto Strait. Basic features of the Adriatic circulation - basin-wide cyclonic circulation with several embedded smaller cyclonic gyres around main pits - are well reproduced by ROMS model. Modelled temperatures and salinities are within corresponding seasonal intervals, although measured profiles generally indicate stronger stratification than modelled ones. Summer circulation in 2011 with current reversal obtained along the eastern Adriatic coast was related to the sampling results of the early fish stages as well as to ARGO drifter movements. Simulated fields from the Adriatic scale model were used to prescribe the initial and open boundary conditions for the interannual simulation in the middle Adriatic coastal domain.


    C. Bradea


    Video assisted techniques were documented by M.Gagner (1996 – video assisted parathyroidectomy), Henry (1999), Shimizu (1999), Ohgami (2000), Miccoli (2000 – video assisted parathyroidectomy and thyroidectomy). The advantage of this kind of surgery: aesthetics i.e. trying to make only small scars on the neck. Our first case of video assisted thyroidectomy was a female 50 years of age, with multinodular goiter, nodules of 2-3 cm in each lobe, admitted in our clinic in December 2008. History of...

  6. Development of CO2 circulators

    The development of the basic machine types we have supplied has not been without problems. The Windscale AGR (the prototype AGR) was a small 1.2 MW vertically up circulator with an inlet temperature of 237 deg. C (459 deg. F). Oil leakage problems occurred and were cured in the works test facility and the machine went into service with no other problems. The Horizontal 5 MW machines for Hinkley/Hunterston were not so fortunate with vibration problems, interface corrosion problems (effecting the whole reactor) and material dimensional stability problems. Oil ingress problems did not show up in test work but were later reported from site. These reports were initially exagerated due to the measuring techniques which took the operators some time to resolve. In the vertical 5 MW machines for Hartlepool and Heysham 1 there are two interesting factors, firstly a spar failure and secondly shaft axial stability. Many of the problems were due to modifications at site or our inability to model all aspects of site installation from which lessons for the future can be learned. The latest stations Torness and Heysham II incorporate these lessons. The machines have been designed with so much margin that during the resolution of the reactor control rod gag problems the machines were run continuously at 20% overload (6.3 MW). From an initial accident case of 350 deg. C inlet temperature, this increased to 458 deg. C and now stands at 585 deg. C. No modifications to the impeller were required. The site experience to date is good with no operational problems reported. (author). 4 figs

  7. Isolation and characterization of circulating tumor cells in prostate cancer

    Elan Shlomo Diamond


    Full Text Available Circulating tumor cells (CTCs are tumor cells found in the peripheral blood that originate from established sites of malignancy and likely have metastatic potential. Analysis of circulating tumor cells CTCs has shown great promise as a prognostic marker as well as a potential source of novel therapeutics. Isolation and characterization these cells for study, however, remain challenging due to their rarity in comparison with other cellular components of peripheral blood. Several techniques that exploit the unique biochemical properties of CTCs have been developed to facilitate isolation of these cells. Positive selection of CTCs is achieved using microfluidic surfaces coated with antibodies against epithelial cell markers or tumor specific antigens such as EpCAM or prostate specific membrane antigen (PSMA. Following isolation, characterization of CTCs may help guide clinical decision-making. For instance, molecular and genetic characterization may shed light on the development of chemotherapy resistance and mechanisms of metastasis without the need for tissue biopsy. This paper will review novel isolation techniques to capture CTCs from patients with advanced cancers, as well as efforts to characterize the CTCs. We will also review ways in which these analyses can assist in clinical decision-making,Conclusion: The study of CTCs provides insight into the molecular biology of their tumors of origin that will eventually guide the development tailored therapeutics. These advances are predicated on high yield and accurate isolation techniques that exploit the unique biochemical features of these cells.

  8. Natural Circulation Performance in Nuclear Power Plants

    The present paper deals with a study of natural circulation in PWR systems, The study consists of two parts: in the first one, natural circulation in experimental facilities simulating PWR plants was analyzed. This made it possible to gather a broad data base which was assumed as a reference for the subsequent part of the research. Seven Nuclear Power Plants nodalizations and additional experimental data from ''non-PWR'' facilities have been considered in the second part of the paper. Conclusions are drawn about natural circulation capabilities derived for the seven Nuclear Power Plants nodalizations and from data base pertinent to three ''non-PWR'' facilities. (author)

  9. Natural circulation performance in nuclear power plants

    The present paper deals with a study of natural circulation in PWR systems. The study consists of two parts: in the first one, natural circulation in experimental facilities simulating PWR plants was analysed. This made it possible to gather a broad data base which was assumed as a reference for the subsequent part of the research. Seven Nuclear Power Plants nodalization and additional experimental data from 'non-PWR' facilities have been considered in the second part of the paper. Conclusions are drawn about natural circulation capabilities derived for the seven Nuclear Power Plants nodalization and from data base pertinent to three 'non-PWR' facilities. (author)

  10. General Circulation Modeling of the Jovian stratosphere

    Sethunadh, J.; Medvedev, A. S.; Hartogh, P.


    The middle atmosphere of Jupiter (1 bar to 1 μ bar) is primarily driven by the heat generated in the interior and by radiative heating and cooling. The stratosphere of Jupiter is less studied, and the mechanisms behind many observed phenomena (e.g.,QQO) in the middle atmosphere as well as the stratospheric circulation patterns remain unknown. We have developed a new General Circulation Model (GCM) to simulate the middle atmospheres of gas giants, which can give important insights to the stratospheric circulation and to the physical and dynamical processes underlying the observed middle atmospheric phenomena.

  11. Circulating miRNA and cancer diagnosis


    miRNAs are a class of small RNA molecules with regulatory function, and play an important role in tumor development and progression. It has been demonstrated that tumor-derived miRNAs exist in the circulating nucleic acids of cancer patients. This phenomenon implies that detection of the circulating miRNA may be an effective method for non-invasive diagnosis of cancer. In this review, we summarize the applications of the circulating miRNA as biomarkers in cancer diagnosis, as well as the latest research progress in this area.

  12. EOP MIT General Circulation Model (MITgcm)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data contains a regional implementation of the Massachusetts Institute of Technology general circulation model (MITgcm) at a 1-km spatial resolution for the...

  13. Global warming and changes in ocean circulation

    Duffy, P.B.; Caldeira, K.C.


    This final report provides an overview of the goals and accomplishments of this project. Modeling and observational work has raised the possibility that global warming may cause changes in the circulation of the ocean. If such changes would occur they could have important climatic consequences. The first technical goal of this project was to investigate some of these possible changes in ocean circulation in a quantitative way, using a state-of -the-art numerical model of the ocean. Another goal was to develop our ocean model, a detailed three-dimensional numerical model of the ocean circulation and ocean carbon cycles. A major non-technical goal was to establish LLNL as a center of excellence in modelling the ocean circulation and carbon cycle.

  14. Sedimentary response to ocean gateway circulation changes

    Heinze, Christoph; Crowley, Thomas J.


    Previous modeling studies suggested that changes in ocean gateways may have exerted a dramatic influence on the ocean circulation. In this pilot study we extend those results to examining the potential ramifications of circulation changes on the sedimentary record. A version of the Hamburg carbon cycle/sediment model is used in these sensitivity experiments. Results indicate that internal reorganization of the ocean circulation can potentially cause very large regional changes in lysocline depth (1500-3000 m) and opal deposition. These shifts are sometimes comparable in magnitude to those imposed by changes in external forcing (e.g., climate, sea level, and weathering). Comparisons of the model response with the geologic record indicate some significant levels of first-order agreement. This exercise suggests that opportunities now exist for physically based modeling of past sediment responses to circulation and climate changes.

  15. GCFR main helium circulator and electric drive

    One of the major objectives of the helium circulators for the gas-cooled fast breeder reactor (GCFR) is to achieve the highest possible operational reliability. This is no simple task considering the plant system integration requirements, auxiliary support systems, all possible transient requirements, and resulting complexity in supplying the driving power, primary coolant flow control, and lubrication and sealing. Therefore, the design of the circulator itself is highly dependent on the type of prime mover selected to drive the circulator, e.g., series turbine, parallel turbine, or electric motor. The circulator main drive has evolved from the series steam turbine drive into the variable-speed, synchronous electric motor drive mounted externally to the reactor and controlled by thyristor variable frequency controller. This design is a result of 18 months of joint effort by General Atomic Company and Westinghouse Electric Corporation


    Yurui Lin; Linzhang Lu


    In this paper,we present a useful result on the structures of circulant inverse Mis not a positive matrix and not equal to c0I,then A is an inverse M-matrix if and only if there exists a positive integer k,which is a proper factor of n,such that cjk>0 for The result is then extended to the so-called generalized circulant inverse M-matrices.

  17. Dynamic Transition Theory for Thermohaline Circulation

    Ma, Tian; Wang, Shouhong


    The main objective of this and its accompanying articles is to derive a mathematical theory associated with the thermohaline circulations (THC). This article provides a general transition and stability theory for the Boussinesq system, governing the motion and states of the large-scale ocean circulation. First, it is shown that the first transition is either to multiple steady states or to oscillations (periodic solutions), determined by the sign of a nondimensional parameter $K$, depending o...

  18. Efficient Circulation of Railway Rolling Stock

    Alfieri, Arianna; Groot, Rutger; Kroon, Leo; Schrijver, Lex


    textabstractRailway rolling stock (locomotives, carriages, and train units) is one of the most significant cost sources for operatorsof passenger trains, both public and private. Rolling stock costsare due to material acquisition, power supply, and material maintenance. The efficient circulation of rolling stock material is therefore one of the objectives pursued. In this paper we focus on the circulation of train units on a single line. In order to utilize the train units on this line in an ...

  19. The Nordic Seas circulation and exchanges.

    Hawker, E.J.


    The Nordic Seas provide the main oceanic connection between the Arctic and the deep global oceans via dense overflows between Greenland and Scotland, into the North Atlantic. An understanding of the circulation and exchanges of this region is vital for any consideration of the implications of high latitude climate change to variability in the Atlantic thermohaline circulation and consequences for regional (European) climate. This thesis makes use of a unique data set of near synoptic hyd...

  20. Local phenomena associated with natural circulation

    The objective of this lecture is to impart to the participants an adequate knowledge of various phenomena encountered in the natural circulation systems of a nuclear reactor. All the components of the primary system of a nuclear reactor are described and phenomena occurring in each of them are explained. A comprehensive coverage of related thermohydraulic relationships is provided which will enable the participants to carryout the process design of a natural circulation system. (author)

  1. Southern Meridional Atmospheric Circulation Associated with IOD

    LIU Na; CHEN Hongxia


    Using the monthly wind and sea surface temperature (SST) data, southern meridional atmospheric circulation cells associated with the Indian Ocean Dipole Mode (IOD) events in the Indian Ocean are for the first time described and examined. The divergent wind and pressure vertical velocity are employed for the identification of atmospheric circulation cells. During the four different phases of the positive IOD events, the anomalous meridional Hadley circulation over the western Indian Ocean shows that the air rises in the tropics, flows poleward in the upper troposphere, sinks in the subtropics, and returns back to the tropics in the lower troposphere. The anomalous Hadley circulation over the eastern Indian Ocean is opposite to that over the western Indian Ocean. During positive IOD events, the meridional Hadley circulation over the eastern Indian Ocean is weakened while it is strengthened over the western Indian Ocean. Correlation analysis between the IOD index and the indices of the Hadley cells also proves that, the atmospheric circulation patterns are evident in every IOD event over the period of record.

  2. Global climate and ocean circulation on an aquaplanet ocean-atmosphere general circulation model

    Smith, R.; Dubois, C.; Marotzke, J.


    A low-resolution coupled ocean–atmosphere general circulation model (OAGCM) is used to study the characteristics of the large-scale ocean circulation and its climatic impacts in a series of global coupled aquaplanet experiments. Three configurations, designed to produce fundamentally different ocean circulation regimes, are considered. The first has no obstruction to zonal flow, the second contains a low barrier that blocks zonal flow in the ocean at all latitudes, creating a single enclosed ...

  3. Circulation model for water circulation and purification in a water Cerenkov detector

    LU Hao-Qi; YANG Chang-Gen; WANG Ling-Yu; XU Ji-Lei; WANG aui-Guang; WANG Zhi-Min; WANG Yi-Fang


    Owing to its low cost and good transparency, highly purified water is widely used as a medium in large water Cerenkov detector experiments. The water circulation and purification system is usually needed to keep the water in good quality. In this work, a practical circulation model is built to describe the variation of the water resistivity in the circulation process and compared with the data obtained from a prototype experiment. The successful test of the model makes it useful in the future design and optimization of the circulation/purification system.

  4. Experimental and numerical investigation of natural circulation phenomena in a rectangular natural circulation loop

    Natural circulation is the key phenomena in the passive cooling systems. Thus, it is important to study the flow characteristics and heat transfer behavior in natural circulation. The natural circulation phenomena in steady state and transient form is investigated using 3D CFD simulations, carried out using OpenFoam 2.2.0. The first part consists of a steady-state study, in which the results are validated by data available from a set of experiments conducted over a range of heater power (130W-360W). The second part consists of a transient study of flow development and establishment of natural circulation within this loop. (author)

  5. Assistance Focus: Africa (Brochure)


    The Clean Energy Solutions Center Ask an Expert service connects governments seeking policy information and advice with one of more than 30 global policy experts who can provide reliable and unbiased quick-response advice and information. The service is available at no cost to government agency representatives from any country and the technical institutes assisting them. This publication presents summaries of assistance provided to African governments, including the benefits of that assistance.

  6. Turning assistive machines into assistive robots

    Argall, Brenna D.


    For decades, the potential for automation in particular, in the form of smart wheelchairs to aid those with motor, or cognitive, impairments has been recognized. It is a paradox that often the more severe a person's motor impairment, the more challenging it is for them to operate the very assistive machines which might enhance their quality of life. A primary aim of my lab is to address this confound by incorporating robotics autonomy and intelligence into assistive machines turning the machine into a kind of robot, and offloading some of the control burden from the user. Robots already synthetically sense, act in and reason about the world, and these technologies can be leveraged to help bridge the gap left by sensory, motor or cognitive impairments in the users of assistive machines. This paper overviews some of the ongoing projects in my lab, which strives to advance human ability through robotics autonomy.


    G. Р. Itkin


    Full Text Available The article briefly describes the history of the non-pulsating type blood pumps for ventricular assist circulation and heart-lung machine. Disclosed the main advantages of these pumps before pulsating type, especially for implantable systems development. However, disadvantages of these pumps and the directions of minimize or eliminate ones have shown. Specific examples of our implantable centrifugal and axial pump developments are presented. Declare the ways to further improve the pumps. 

  8. Experimental study of the natural circulation phenomena

    The objective of this paper is to study the natural circulation in experimental loops and extend the results to nuclear facilities. New generation of compact nuclear power plants use the natural circulation as cooling and residual heat removal systems in case of accidents or shutdown. Lately the interest in this phenomenon, by scientific community, has increased. The experimental loop, described in this paper, was assembled at Escola Politecnica - USP at the Chemical Engineering Department. It is the goal to generate information to help with the understanding of the one and two phase natural circulation phenomena. Some experiments were performed with different levels of heat power and different flow of the cooling water at the secondary circuit. The data generated from these experiments are going to be used to validate some computational thermal hydraulic codes. Experimental results for one and two phase regimes are presented as well as the proposed model to simulate the flow regimes with the RELAP5 code. (author)


    Through the process of thermal ionization, intense stellar irradiation renders hot Jupiter atmospheres electrically conductive. Simultaneously, lateral variability in the irradiation drives the global circulation with peak wind speeds of the order of ∼km s–1. In turn, the interactions between the atmospheric flows and the background magnetic field give rise to Lorentz forces that can act to perturb the flow away from its purely hydrodynamical counterpart. Using analytical theory and numerical simulations, we show here that significant deviations away from axisymmetric circulation are unstable in presence of a non-negligible axisymmetric magnetic field. Specifically, our results suggest that dayside-to-nightside flows, often obtained within the context of three-dimensional circulation models, only exist on objects with anomalously low magnetic fields, while the majority of highly irradiated exoplanetary atmospheres are entirely dominated by zonal jets

  10. Tropical convective transport and the Walker circulation

    J. S. Hosking


    Full Text Available We introduce a methodology to visualise rapid vertical and zonal tropical transport pathways. Using prescribed sea-surface temperatures in four monthly model integrations for 2005, preferred transport routes from the troposphere to the stratosphere are found in the model over the Maritime Continent (MC in November and February, i.e., boreal winter. In these months, the ascending branch of the Walker Circulation over the MC is formed in conjunction with strong deep convection, allowing fast transport into the stratosphere. At the same time, the downwelling branch of the Walker Circulation is enhanced over the East Pacific, compared to other months in 2005, reducing locally the upward transport from emissions below. We conclude that the Walker circulation plays an important role in the seasonality of fast tropical transport from the troposphere to the stratosphere and so impacts at the same time the potential supply of surface emissions.

  11. Use of natural circulation flow map

    Natural circulation in complex systems, considering the experimental simulators of PWR and the experience gained in analyzing natural circulation experiments performed in those systems are referred to. In particular, the NC scenarios occurring at different values of the primary system mass inventory are studied. Data have been gathered and analyzed coming from the experimental facilities (PWR simulators, or Integral Test Facilities, ITF) named Semiscale, Spes, Lobi, Bethsy, Pkl and Lstf. The case of PWR design, the NC should be seen as the fundamental mechanism for removing core following accidents or events that cause unavailability of primary circulation pumps. The NC phenomenon constitutes the basis for the layout of the primary system with core located in the bottom of vessel and steam generators a few meters above the top of the active fuel

  12. Cryogenic hydrogen circulation system of neutron source

    Cold neutron sources of reactors and spallation neutron sources are classic high flux neutron sources in operation all over the world. Cryogenic fluids such as supercritical or supercooled hydrogen are commonly selected as a moderator to absorb the nuclear heating from proton beams. By comparing supercritical hydrogen circulation systems and supercooled hydrogen circulation systems, the merits and drawbacks in both systems are summarized. When supercritical hydrogen circulates as the moderator, severe pressure fluctuations caused by temperature changes will occur. The pressure control system used to balance the system pressure, which consists of a heater as an active controller for thermal compensation and an accumulator as a passive volume controller, is preliminarily studied. The results may provide guidelines for design and operation of other cryogenic hydrogen system for neutron sources under construction

  13. Quantification of bronchial circulation perfusion in rats

    Wietholt, Christian; Molthen, Robert C.; Haworth, Steven T.; Roerig, David L.; Dawson, Christopher A.; Clough, Anne V.


    The bronchial circulation is thought to be the primary blood supply for pulmonary carcinomas. Thus, we have developed a method for imaging and quantifying changes in perfusion in the rat lung due to development of the bronchial circulation. A dual-modality micro-CT/SPECT system was used to detect change in perfusion in two groups of rats: controls and those with a surgically occluded left pulmonary artery. Both groups were imaged following injections on separate days i) 2mCi of Tc99m labeled macroaggregated albumin (MAA) into the left carotid artery (IA) and ii) a similar injection into the femoral vein (IV). The IA injection resulted in Tc99m accumulation in capillaries of the systemic circulation including the bronchial circulation, whereas the IV resulted in Tc99m accumulation in the pulmonary capillaries. Ordered subset expectation maximization (OSEM) was used to reconstruct the SPECT image volumes and a Feldkamp algorithm was used to reconstruct the micro-CT image volumes. The micro-CT and SPECT volumes were registered, the SPECT image volume was segmented using the right and left lung boundaries defined from the micro-CT volume, and the ratio of IA radioactivity accumulation in the left lung to IV radioactivity accumulation in both lungs was used as a measure of left lung flow via the bronchial circulation. This ratio was ~0.02 for the untreated rats compared to the treated animals that had an increased flow ratio of ~0.21 40 days after left pulmonary artery occlusion. This increase in flow to the occluded left lung via the bronchial circulation suggests this will be a useful model for further investigating antiangiogenic treatments.

  14. Experimental study of natural circulation circuit

    Lemos, Wanderley F.; Su, Jian, E-mail:, E-mail: [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LASME/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Simulacao e Metodos Numericos; Faccini, Jose L.H., E-mail: [Instituto de Engenharia Nuclear (LTE/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental


    This work presents an experimental study about fluid flows behavior in natural circulation, under conditions of single-phase flow. The experiment was performed through experimental thermal-hydraulic circuit built at IEN. This test equipment has performance similar to passive system of residual heat removal present in Advanced Pressurized Water Reactors (APWR). This experimental study aims to observing and analyzing the natural circulation phenomenon, using this experimental circuit that was dimensioned and built based on concepts of similarity and scale. This philosophy allows the analysis of natural circulation behavior in single-phase flow conditions proportionally to the functioning real conditions of a nuclear reactor. The experiment was performed through procedures to initialization of hydraulic feeding of primary and secondary circuits and electrical energizing of resistors installed inside heater. Power controller has availability to adjust values of electrical power to feeding resistors, in order to portray several conditions of energy decay of nuclear reactor in a steady state. Data acquisition system allows the measurement and monitoring of the evolution of the temperature in various points through thermocouples installed in strategic points along hydraulic circuit. The behavior of the natural circulation phenomenon was monitored by graphical interface on computer screen, showing the temperature evolutions of measuring points and results stored in digital spreadsheets. The results stored in digital spreadsheets allowed the getting of data to graphic construction and discussion about natural circulation phenomenon. Finally, the calculus of Reynolds number allowed the establishment for a correlation of friction in function of geometric scales of length, heights and cross section of tubing, considering a natural circulation flow throughout in the region of hot leg. (author)

  15. Fort St. Vrain circulator operating experience

    Fort St. Vrain, on the system of Public Service Company of Colorado, is the only high-temperature gas-cooled power reactor in the United States. Four helium circulators are utilized in this plant to transfer heat from the reactor to the steam generators. These unique machines have a single stage axial flow helium compressor driven by a single stage steam turbine. A single stage water driven (pelton wheel) turbine is the back-up drive utilizing either feed water, condensate, or fire water as the driving fluid. Developmental testing of the circulators was accomplished prior to installation into Fort St. Vrain. A combined machine operating history of approximately 250,000 hours has shown these machines to be of conservative design and proven mechanical integrity. However, many problems have been encountered in operating the complex auxiliaries which are necessary for successful circulator and plant operation. It has been 15 years since initial installation of the circulators occurred at Fort St. Vrain. During this time, a number of significant issues had to be resolved dealing specifically with machine performance. These events include cavitation damage of the pelton wheels during the initial plant hot functional testing, cracks in the water turbine buckets and cervic coupling, static shutdown seal bellows failure, and, most recently, degradation of components within the steam drive assembly. Unreliable operation particularly with the circulator auxiliaries has been a focus of attention by Public Service Company of Colorado. Actions to replace or significantly modify the existing circulators and their auxiliaries are currently awaiting decisions concerning the long-term future of the Fort St. Vrain plant. (author). 10 refs, 7 figs, 2 tabs

  16. Service water assistance program

    Munchausen, J.H. [EPRI Plant Support Engineering, Charlotte, NC (United States)


    The Service Water Assistance Program was developed to provide utility service water system engineers with a mechanism to quickly and efficiently address service water issues. Since its inception, its ability to assist utilities has resulted in a reduction in the operations and maintenance costs associated with service water systems and has provided a medium for EPRI awareness of industry service water issues.

  17. Service water assistance program

    The Service Water Assistance Program was developed to provide utility service water system engineers with a mechanism to quickly and efficiently address service water issues. Since its inception, its ability to assist utilities has resulted in a reduction in the operations and maintenance costs associated with service water systems and has provided a medium for EPRI awareness of industry service water issues

  18. Egress door opening assister

    Allison, Thomas L.


    A door opening spring assistance apparatus is set forth that will automatically apply a door opening assistance force using a combination of rods and coil springs. The release of the rods by the coil springs reduces the force required to set the door in motion.

  19. The stripline circulator theory and practice

    Helszajn, J


    Stripline circulator theory and applications from the world's foremost authority. The stripline junction circulator is a unique three-port non-reciprocal microwave junction used to connect a single antenna to both a transmitter and a receiver. Its operation relies on the interaction between an electron spin in a suitably magnetized insulator with an alternating radio frequency magnetic field. In its simplest form, it consists of a microwave planar gyromagnetic resonator symmetrically coupled by three transmission lines. This book explores the magnetic interaction involved in the stripline circ.

  20. Quenching phenomena in natural circulation loop

    Umekawa, Hisashi; Ozawa, Mamoru [Kansai Univ., Osaka (Japan); Ishida, Naoki [Daihatsu Motor Company, Osaka (Japan)


    Quenching phenomena has been investigated experimentally using circulation loop of liquid nitrogen. During the quenching under natural circulation, the heat transfer mode changes from film boiling to nucleate boiling, and at the same time flux changes with time depending on the vapor generation rate and related two-phase flow characteristics. Moreover, density wave oscillations occur under a certain operating condition, which is closely related to the dynamic behavior of the cooling curve. The experimental results indicates that the occurrence of the density wave oscillation induces the deterioration of effective cooling of the heat surface in the film and the transition boiling regions, which results in the decrease in the quenching velocity.

  1. The circulation of the Mozambique channel

    Sætre, Roald; Da Silva, António Jorge


    Based on hydrographic data from 1977 to 1980 off the coast of Mozambique and historical data from the Mozambique Channel, the general circulation pattern of the area is described. The circulation pattern is characterized by the influence of three anticyclonic gyres covering the northern, the central, and the southern parts of the channel. Additionally, smaller cyclonic eddies are observed, of which some probably are topographically induced. The results strongly indicate that in the upper 1000 m the role of the Mozambique Current as one of the tributaries to the Agulhas Current is of minor significance and draw into question the concept of the Mozambique Current as a continuous one.

  2. Blowing Circulation Control on a Seaplane Airfoil

    Guo, B. D.; Liu, P. Q.; Qu, Q. L.


    RANS simulations are presented for blowing circulation control on a seaplane airfoil. Realizable k-epsilon turbulent model and pressure-based coupled algorithm with second-order discretization were adopted to simulate the compressible flow. Both clear and simple flap configuration were simulated with blowing momentum coefficient Cμ = 0, 0.15 and 0.30. The results show that blowing near the airfoil trailing edge could enhance the Coanda effect, delay the flow separation, and increase the lift coefficient dramatically. The blowing circulation control is promising to apply to taking off and landing of an amphibious aircraft or seaplane.

  3. Scaling Analysis of Natural Circulation Flow Loop

    To improve the thermal margin for the severe accident measures in high-power reactors, engineered corium cooling systems involving boiling-induced two-phase natural circulation have been proposed for decay heat removal. The boiling-induced natural circulation flow is generated in a coolant path between a hot vessel wall and cold coolant reservoir. In general, an increase in the natural circulation mass flow rate of the coolant leads to an increase in the critical heat flux (CHF) on the hot wall, thus enhancing the thermal margin. An ex-vessel core catcher under consideration, which is one of the engineered corium cooling system, is a passive system consisting of an inclined engineered cooling channel made of a single channel between the body of the core catcher and the inside wall of the reactor cavity. Under severe accident conditions, water is supplied from the IRWST to the engineered cooling channel. The water in the inclined channel absorbs the decay heat transferred from the corium through the carbon steel structure of the core catcher body and boils off as steam. The latter is subsequently released into the free volume of the containment above the corium spreading compartment. Water continues to flow from the IRWST to the cooling channel as a result of buoyancy-driven natural circulation. The engineered cooling channel is designed to provide effective long-term cooling and stabilization of the corium mixture in the core catcher body while facilitating steam venting. In this study, the scaling analysis was performed by solving the natural circulation flow loop equation for the cooling channel in the ex-vessel core catcher. The scaling analysis was performed by solving the natural circulation flow loop equation for the cooling channel in the ex-vessel core catcher. The boiling-induced natural circulation flow in the cooling channel of the core catcher has been modeled by considering the conservation of mass, momentum and energy in the two-phase mixture, along

  4. Applications of Circulation Control, Yesterday and Today

    Jonathan Kweder; Chad C. Panthe; James E. Smit


    Circulation control, an aerodynamic method of changing the properties of an airfoil, such as lift, camber and angle of attack, has been used in several unique ways since its inception, as an enhancement to fixed wing aircraft, in the 1960’s. Early in the research venture, this technology was used on the main wing of an aircraft in conjunction with a Coandă surface, such as a rounded trailing edge or a deployable flap. Research during this time proved to be the foundation of the circulation co...

  5. Applications of Circulation Control, Yesterday and Today

    Jonathan Kweder


    Full Text Available Circulation control, an aerodynamic method of changing the properties of an airfoil, such as lift, camber and angle of attack, has been used in several unique ways since its inception, as an enhancement to fixed wing aircraft, in the 1960’s. Early in the research venture, this technology was used on the main wing of an aircraft in conjunction with a Coandă surface, such as a rounded trailing edge or a deployable flap. Research during this time proved to be the foundation of the circulation control technology and showed that small amounts of exit jet velocity could have a large impact on the aerodynamics of an airfoil. In the 1970’s the inspirations that drove circulation control research changed from design work to optimization of the parameters which were found to have the most effect on circulation control. These studies included slot placement, favorable momentum coefficient, and pressurization benefits and determents. This research period also allowed for expansion of the uses of circulation control to submarine/hydrodynamic and rotary wing applications. Newest research has brought on several propeller driven applications and the recent push for efficient renewable research has allowed circulation control research technologies to evolve into use in wind turbine and water turbine applications. The idea being that with circulation control the turbine can adapt easier to the changing wind velocity and direction and ultimately capture more power than an un-augmented turbine. As with most new and novel technologies there is a process and time delay associated with their development and ultimate application. For some technologies the market, or the supporting hardware, are lacking and sometimes the technology has strong advocacies for yet to be fulfilled expectations. In most of these cases a strong idea will re-surface repeatedly until the art has matured, or the better solution is found. This paper will focus on the previously developed

  6. Designing Real Time Assistive Technologies

    Sonne, Tobias; Obel, Carsten; Grønbæk, Kaj


    design criteria in relation to three core components (sensing, recognizing, and assisting) for designing real time assistive technologies for children with ADHD. Based on these design criteria, we designed the Child Activity Sensing and Training Tool (CASTT), a real time assistive prototype that captures......) real time assistive technologies have potential to assist children with ADHD in regaining attention in critical school situations....

  7. A novel left ventricular assist device with impeller pump and brushless motor compacted in one unit


    The impeller pump we developed has assisted the circulation of calves for two months, but further improvements to solve the problems of bearing wear and thrombosis along the bearing are desirable. Thus we have designed a new left ventricular assist device (LVAD) with impeller pump and brushless motor compacted in one unit, for which a ceramic bearing and a purge system through the bearing have been devised. The first experiments indicate that this new device could prospectively work for more than one year.

  8. Weatherization Assistance Program Technical Assistance Center

    Robert Adams


    The following is a synopsis of the major achievements attributed to the operation of the Weatherization Assistance Program Technical Assistance Center (WAPTAC) by the National Association for State Community Services Programs (NASCSP). During the past five years, the WAPTAC has developed into the premier source for information related to operating the Weatherization Assistance Program (WAP) at the state and local levels. The services provide through WAPTAC include both virtual technical support as well as hands-on training and instruction in classroom and in the field. The WAPTAC achieved several important milestones during its operation including the establishment of a national Weatherization Day now celebrated in most states, the implementation of a comprehensive Public Information Campaign (PIC) to raise the awareness of the Program among policy makers and the public, the training of more than 150 new state managers and staff as they assume their duties in state offices around the country, and the creation and support of a major virtual information source on the Internet being accessed by thousands of staff each month. The Weatherization Assistance Program Technical Assistance Center serves the Department of Energy's (DOE) Office of Weatherization and Intergovernmental Program as a valuable training and technical assistance resource for the network of 54 direct state grantees (50 states, District of Columbia and three Native American tribes) and the network of 900 local subgrantees (comprised of community action agencies, units of local government, and other non-profit organizations). The services provided through WAPTAC focus on standardizing and improving the daily management of the WAP. Staff continually identify policies changes and best practices to help the network improve its effectiveness and enhance the benefits of the Program for the customers who receive service and the federal and private investors. The operations of WAPTAC are separated into

  9. Transient characteristic analysis of integral pressurized water reactor from forced circulation to natural circulation

    Natural circulation of nuclear reactor has heat dumpling capacity, which can improve the inherent safety of reactor. In this paper, the conceptional design of integrated pressurized water reactor was studied and RELAP5/MOD3.4 was used to analyze transient characteristic in the process from forced circulation to natural circulation. What's more, the influence of reactor power, resistance, moment of inertia of main pump, and various operation strategies on transient characteristic in this conversion process were also studied. (authors)

  10. On Pareto theory of circulation of elites

    Ricardo P\\'erez-Marco


    We prove that Pareto theory of circulation of elites results from our wealth evolution model, Kelly criterion for optimal betting and Keynes' observation of "animal spirits" that drive the economy and cause that human financial decisions are prone to excess risk-taking.

  11. General circulation modeling of the Jupiter stratosphere

    Sethunadh, J.; Medvedev, A. S.; Hartogh, P.


    The stratosphere of Jupiter extends for more than 350 km above the cloud top. It is driven almost equally by the radiative heating and cooling within the atmosphere, and by heat from below. We present first results of simulations with the newly developed general circulation model (GCM).

  12. General circulation of the Jovian stratosphere

    Medvedev, Alexander S.; Sethunadh, Jisesh; Hartogh, Paul

    The stratosphere of Jupiter is a convectively stable and coldest layer that extends for about 350 km above the tropopause. The dynamics of stratospheres of fast rotating gas giants differ from that of terrestrial-like planets, their modeling is more challenging, and is still little known despite a growing number of observations. We present results of simulations with a newly developed Jovian general circulation model, which covers the altitudes between one bar and one microbar. The results demonstrate a high sensitivity of the circulation to variations of eddy diffusion, which, in turn, depends on the model resolution and assumed background viscosity. In the lower stratosphere, the multiple circulation cells associated with the tropospheric alternating jets dominate. Higher, a weak two-cell equator-to-pole transport forms due to the influence of smaller-scale eddies. The strength and extent of this circulation are defined by the momentum supplied by shallow and vertically propagating waves, and are consistent with observations of the Shoemaker-Levi 9 comet traces. We will also discuss the dynamical implications of our recent finding that radiative forcing exponentially increases with height, rather than approximately constant throughout the Jovian stratosphere, as was thought before (see presentation of T. Kuroda at B0.3 session).

  13. Detecting Holocene changes in thermohaline circulation

    L. D. Keigwin; Boyle, E. A.


    Throughout the last glacial cycle, reorganizations of deep ocean water masses were coincident with rapid millennial-scale changes in climate. Climate changes have been less severe during the present interglacial, but evidence for concurrent deep ocean circulation change is ambiguous.

  14. A Circulation Model for Busy Public Libraries.

    Bagust, A.


    Develops stochastic model of library borrowing using Negative Binomial distribution applied to circulation data obtained from Huddersfield Public Library. Evidence concerning process of popularity decay is presented and method is given by which relegation tests can be constructed to maintain optimum turnover. Eight references and statistical…

  15. Circulating amounts of osteoprotegerin and RANK ligand

    Abrahamsen, Bo; Hjelmborg, Jacob Vb; Kostenuik, Paul;


    UNLABELLED: Osteoprotegerin (OPG) is a circulating receptor that inhibits osteoclastogenesis by binding to RANK ligand (RANKL). OPG knock-out animals develop severe osteoporosis. Treatment with OPG lowers bone resorption and increases BMD. OPG production is influenced by a wide range of hormones ...

  16. FEMA Hazard Mitigation Assistance Flood Mitigation Assistance (FMA) Data

    Department of Homeland Security — This dataset contains closed and obligated projects funded under the following Hazard Mitigation Assistance (HMA) grant programs: Flood Mitigation Assistance (FMA)....

  17. Social and Human Service Assistants

    ... Similar Occupations More Info Summary Social and human service assistants help clients to identify and obtain benefits and services. Quick ... and Human Service Assistants Do Social and human service assistants provide client services, including support for families, in a wide ...

  18. Observations of the summer Red Sea circulation

    Sofianos, Sarantis S.; Johns, William E.


    Aiming at exploring and understanding the summer circulation in the Red Sea, a cruise was conducted in the basin during the summer of 2001 involving hydrographic, meteorological, and direct current observations. The most prominent feature, characteristic of the summer circulation and exchange with the Indian Ocean, is a temperature, salinity, and oxygen minimum located around a depth of 75 m at the southern end of the basin, associated with Gulf of Aden Intermediate Water inflowing from the Gulf of Aden during the summer season as an intruding subsurface layer. Stirring and mixing with ambient waters lead to marked increases in temperature (from 16.5 to almost 33°C) and salinity (from 35.7 to more than 38 psu) in this layer by the time it reaches midbasin. The observed circulation presents a very vigorous pattern with strong variability and intense features that extend the width of the basin. A permanent cyclone, detected in the northern Red Sea, verifies previous observations and modeling studies, while in the central sector of the basin a series of very strong anticyclones were observed with maximum velocities exceeding 1 m/s. The three-layer flow pattern, representative of the summer exchange between the Red Sea and the Gulf of Aden, is observed in the strait of Bab el Mandeb. In the southern part of the basin the layer flow is characterized by strong banking of the inflows and outflows against the coasts. Both surface and intermediate water masses involved in the summer Red Sea circulation present prominent spatial variability in their characteristics, indicating that the eddy field and mixing processes play an important role in the summer Red Sea circulation.

  19. Decontamination of CAGR gas circulator components

    This paper describes the development and full-scale trial of two methods for removal of radioactive contamination on the surfaces of CAGR gas circulator components. The two methods described are a particle impact cleaning (PIC) decontamination technique and an electrochemical technique, 'electro-swabbing', which is based on the principle of decontamination by electro-polishing. In developing these techniques it was necessary to take account of the physical and chemical nature of the surface deposits on the gas circulator components; these were shown to consist of magnetite-type oxide and carbonaceous material. In order to follow the progress of the decontamination it was also necessary to develop a surface sampling technique which was effective and precise under these conditions; an electrochemical technique, employing similar principles to the electro-swabbing process, was developed for this purpose. The full-scale trial of the PIC decontamination technique was carried out on an inlet guide vane (IGV) assembly, this having been identified as the component from the gas circulator which contributes most to the radiation dose accumulated during routine circulator maintenance. The technique was shown to be practically viable and some 99% of the radioactive contamination was readily removed from the treated surfaces with only negligible surface damage being caused. The full-scale trial of the electro-swabbing decontamination technique was carried out on a gas circulator impeller. High decontamination factors were again achieved with ≥ 99% of the radioactive contamination being removed from the treated surfaces. The technique has practical limitations in terms of handling and treatment of waste-arisings. However, the use of specially-designed swabbing electrodes may allow the treatment of constricted geometries inaccessible to techniques such as PIC. The technique is also highly suitable for the treatment of soft-finish materials and of components fabricated from a

  20. Effects of Microtopography on Overmarsh Circulation

    Sullivan, J. C.; Torres, R.; Garrett, A.


    Authors: J.C. Sullivan, R. Torres, A.J. Garrett In this study we systematically degrade a high-resolution, high precision salt marsh DEM and characterize the effects of DEM smoothing on overmarsh circulation. The question driving this effort is: How much topographic detail is needed to accurately simulate salt marsh circulation? The hydrodynamic model Delft3D was applied to data from a previous dye-tracer study in a 2 km2 semi-enclosed salt marsh basin at Skidaway Institute of Oceanography near Savannah, Georgia, USA. Overmarsh circulation was simulated for each smoothed DEM over a 5 day period corresponding to spring tide conditions. Results show that flood and ebb pathways differ significantly, but this effect is less apparent as the DEM is smoothed. Also, the flushing time (Tf) decreases with smoothing leading to greater dilution of a dye tracer with each tidal cycle. Observations at the macro, meso and micro scale show that flood and ebb flows become stronger through a consistent set of flow paths, including intertidal creeks, and differences in overmarsh circulation are more apparent in low marsh and channel head areas. This work shows that accurate representation of overmarsh circulation requires that the DEM resolve creek and low lying marsh structures at a spatial scale of 2-4m, but not necessarily the smallest tidal creeks (< 1m in width and depth). The next phase of this work will be to incorporate spatial variations in vegetation cover using RULLI (Remote Ultra Low-Light Imaging) remote sensing technology developed by the Department of Energy.

  1. Circulation factors affecting precipitation over Bulgaria

    Nojarov, Peter


    The objective of this paper is to determine the influence of circulation factors on precipitation in Bulgaria. The study succeeds investigation on the influence of circulation factors on air temperatures in Bulgaria, as the focus here is directed toward precipitation amounts. Circulation factors are represented through two circulation indices, showing west-east or south-north transport of air masses over Bulgaria and four teleconnection indices (patterns)—North Atlantic Oscillation, East Atlantic, East Atlantic/Western Russia, and Scandinavian. Omega values at 700-hPa level show vertical motions in the atmosphere. Annual precipitation trends are mixed and not statistically significant. A significant decrease of precipitation in Bulgaria is observed in November due to the strengthening of the eastward transport of air masses (strengthening of EA teleconnection pattern) and anticyclonal weather (increase of descending motions in the atmosphere). There is also a precipitation decrease in May and June due to the growing influence of the Azores High. An increase of precipitation happens in September. All this leads to a redistribution of annual precipitation course, but annual precipitation amounts remain the same. However, this redistribution has a negative impact on agriculture and winter ski tourism. Zonal circulation has a larger influence on precipitation in Bulgaria compared to meridional. Eastward transport throughout the year leads to lower than the normal precipitation, and vice versa. With regard to the four teleconnection patterns, winter precipitation in Bulgaria is determined mainly by EA/WR teleconnection pattern, spring and autumn by EA teleconnection pattern, and summer by SCAND teleconnection pattern.

  2. Robotic assisted laparoscopic colectomy.

    Pandalai, S


    Robotic surgery has evolved over the last decade to compensate for limitations in human dexterity. It avoids the need for a trained assistant while decreasing error rates such as perforations. The nature of the robotic assistance varies from voice activated camera control to more elaborate telerobotic systems such as the Zeus and the Da Vinci where the surgeon controls the robotic arms using a console. Herein, we report the first series of robotic assisted colectomies in Ireland using a voice activated camera control system.

  3. Enhancement of natural circulation type domestic solar hot water system performance by using a wind turbine

    Ramasamy, K. K.; Srinivasan, P. S. S.


    Performance improvement of existing 200 litres capacity natural convection type domestic solar hot water system is attempted. A two-stage centrifugal pump driven by a vertical axis windmill having Savonius type rotor is added to the fluid loop. The windmill driven pump circulates the water through the collector. The system with necessary instrumentation is tested over a day. Tests on Natural Circulation System (NCS) mode and Wind Assisted System (WAS) mode are carried out during January, April, July and October, 2009. Test results of a clear day are reported. Daily average efficiency of 25-28 % during NCS mode and 33-37 % during WAS mode are obtained. With higher wind velocities, higher collector flow rates and hence higher efficiencies are obtained. In general, WAS mode provides improvements in efficiency when compared to NCS mode.

  4. Development Strategies for Rural Key Circulation Service Network


    The rural key circulation service network is an important channel for ensuring agricultural products’entry to market and urban industrial products’entry to rural areas.Through in-depth survey and research,we took a look at development changes and current situations of three circulation service networks,namely,circulation of nondurable consumer goods,circulation of agricultural means of production,and circulation of agricultural products.Based on several key problems in rural circulation service network,such as logistics problem,delivery problem,backward transaction mode,and the last kilometer information,we put forward corresponding development countermeasures.

  5. Robot-Assisted Prostatectomy

    Full Text Available ... this da Vinci assisted laparoscopic radical prostatectomy. Our scrub, which is Alex Santander, our nurse anesthetist back ... Okay, Dr. Pinon, you’re going to come scrub in? Yes, I will, yes. Dr. Pinon is ...

  6. Robot-Assisted Prostatectomy

    Full Text Available ... joysticks and his feet pressing on pedals to control these robotic instruments. There’s almost always an assistant ... Sure. To help divide the tissue and to control bleeding. Right now I’m going to clean ...

  7. Superfund Technical Assistance Grants

    U.S. Environmental Protection Agency — This asset includes data related to the Superfund Technical Assistance Grant program, including grant number, award amounts, award dates, period of performance,...

  8. Financial Assistance Information

    ... Other Sites: Genetic and Rare Diseases Information Center Financial Assistance Information The National Institutes of Health (NIH) ... area call 900-638-0742. Top of page Financial Aid for Medical Treatments Information on financial aid ...

  9. Robot-Assisted Prostatectomy

    Full Text Available ... Robotic Surgery. My name is Dr. Andy Pinon. This is my partner, Dr. Darren Bruck. He’s going ... at the very beginning, helping us navigate through this da Vinci assisted laparoscopic radical prostatectomy. Our scrub, ...

  10. Robot-Assisted Prostatectomy

    Full Text Available Watch South Miami Hospital Surgeons Perform Robot-Assisted Prostatectomy South Miami Hospital Miami, FL January 19, 2010 Good afternoon. Welcome to the South Miami Hospital operating room, the Center ...

  11. Computer assisted radiology

    The proceedings of the CAR'93 symposium present the 126 oral papers and the 58 posters contributed to the four Technical Sessions entitled: (1) Image Management, (2) Medical Workstations, (3) Digital Image Generation - DIG, and (4) Application Systems - AS. Topics discussed in Session (1) are: picture archiving and communication systems, teleradiology, hospital information systems and radiological information systems, technology assessment and implications, standards, and data bases. Session (2) deals with computer vision, computer graphics, design and application, man computer interaction. Session (3) goes into the details of the diagnostic examination methods such as digital radiography, MRI, CT, nuclear medicine, ultrasound, digital angiography, and multimodality imaging. Session (4) is devoted to computer-assisted techniques, as there are: computer assisted radiological diagnosis, knowledge based systems, computer assisted radiation therapy and computer assisted surgical planning. (UWA). 266 figs

  12. Homelessness Assistance and Resources

    ... Performance Measure Resources View videos, programming specifications, an introductory guide, and more on how CoCs can measure ... a Program Affordable Housing Community Development Consolidated Planning Economic Development Environmental Review Financial Management Homelessness Assistance Rural ...

  13. Assisted Reproductive Technology

    Assisted reproductive technology (ART) is used to treat infertility. It includes fertility treatments that handle both a woman's egg ... back in the woman's body. In vitro fertilization (IVF) is the most common and effective type of ...

  14. Robot-Assisted Prostatectomy

    Full Text Available ... prostatic fossa. Okay. This is where the prostate sat. If you look at the bottom of the ... as assistant, and I am waiting for the new instruments to be inserted so we can perform ...

  15. Heteronuclear proton assisted recoupling

    De Paëpe, Gaël; Lewandowski, Józef R.; Loquet, Antoine; Eddy, Matt; Megy, Simon; Böckmann, Anja; Griffin, Robert G.


    We describe a theoretical framework for understanding the heteronuclear version of the third spin assisted recoupling polarization transfer mechanism and demonstrate its potential for detecting long-distance intramolecular and intermolecular 15N–13C contacts in biomolecular systems. The pulse sequence, proton assisted insensitive nuclei cross polarization (PAIN-CP) relies on a cross term between 1H–15N and 1H–13C dipolar couplings to mediate zero- and/or double-quantum 15N–13C recoupling. In ...

  16. Mechanical Circulatory Assist Devices

    Park, Sang B.; Magovern, George J.; Christlieb, Ignacio Y.; Kao, Race L.


    Cardiogenic shock occurs in about 10% of the 1.5 million patients who suffer myocardial infarction and in approximately 1% of the 200,000 patients who undergo open-heart surgery each year. The ventricular assist device decreases the workload of the failing ventricles and increases the blood flow through the coronary system. Recovery of failing myocardium after mechanical circulatory assistance has been well documented; however, the mechanisms that contribute to the recovery of a failing heart...

  17. Circulation patterns in active lava lakes

    Redmond, T. C.; Lev, E.


    Active lava lakes provide a unique window into magmatic conduit processes. We investigated circulation patterns of 4 active lava lakes: Kilauea's Halemaumau crater, Mount Erebus, Erta Ale and Nyiragongo, and in an artificial "lava lake" constructed at the Syracuse University Lava Lab. We employed visual and thermal video recordings collected at these volcanoes and use computer vision techniques to extract time-dependent, two-dimensional surface velocity maps. The large amount of data available from Halemaumau enabled us to identify several characteristic circulation patterns. One such pattern is a rapid acceleration followed by rapid deceleration, often to a level lower than the pre-acceleration level, and then a slow recovery. Another pattern is periodic asymmetric peaks of gradual acceleration and rapid deceleration, or vice versa, previously explained by gas pistoning. Using spectral analysis, we find that the dominant period of circulation cycles at approximately 30 minutes, 3 times longer than the dominant period identified previously for Mount Erebus. Measuring a complete surface velocity field allowed us to map and follow locations of divergence and convergence, therefore upwelling and downwelling, thus connecting the surface flow with that at depth. At Nyiragongo, the location of main upwelling shifts gradually, yet is usually at the interior of the lake, for Erebus it is usually along the perimeter yet often there is catastrophic downwelling at the interior; For Halemaumau upwelling/downwelling position is almost always on the perimeter. In addition to velocity fields, we developed an automated tool for counting crustal plates at the surface of the lava lakes, and found a correlation, and a lag time, between changes if circulation vigor and the average size of crustal plates. Circulation in the artificial basaltic lava "lake" was limited by its size and degree of foaming, yet we measured surface velocities and identify patterns. Maximum surface velocity


    Artificial circulation and hypolimnetic aeration are management techniques for oxygenating eutrophic lakes subject to water quality problems, algal blooms, and fishkills. Artificial circulation is achieved by injecting diffused air into lower waters, by mechanial pumping of water...

  19. Silent Circulation of Ross River Virus in French Polynesia

    Maite Aubry


    Discussion: Our results support the existence of autochthonous RRV transmission and suggest that this pathogen has silently circulated in French Polynesia. These findings raise the question of possible undetected circulation of RRV in other Pacific Island Countries and Territories.

  20. Author supervision organization in the main circulation pump operation and repair at the Ignalina NPP

    The order and results of the author supervision by designer over the operation and maintenance of the main circulation pump TsVN-8 at the Ignalina NPP (Lithuania) are considered. The main tasks of supervision include knowledge of information on technical state, technical-operational characteristics and running time of the pumps, analysis of available information and its application by solving the problems, arising in the course of operation, provision for technical assistance, if necessary, to the power plant personnel on problems of the pumps operation, maintenance and repair

  1. Anti-cyclonic circulation driven by the estuarine circulation in a gulf type ROFI

    Fujiwara, T.; Sanford, L. P.; Nakatsuji, K.; Sugiyama, Y.


    Baroclinic residual circulation processes are examined in gulf type Regions Of Freshwater Influence (ROFIs), which have large rivers discharging into a rounded head wider than the Rossby internal deformation radius. Theoretical and observational investigations concentrate on Ise Bay, Japan, with supporting data from Osaka Bay and Tokyo Bay. Simplified analytical solutions are derived to describe the primary features of the circulation. Three dimensional residual current data collected using moored current meters and shipboard acoustic doppler current profilers (ADCPs), satellite imagery and density structure data observed using STDs, are presented for comparison to the theoretical predictions. There are three key points to understanding the resulting circulation in gulf type ROFIs. First, there are likely to be three distinct water masses: the river plume, a brackish upper layer, and a higher salinity lower layer. Second, baroclinic processes in gulf type ROFIs are influenced by the Earth's rotation at first order. Residual currents are quasi-geostrophic and potential vorticity is approximately conserved. Third, the combined effects of a classical longitudinal estuarine circulation and the Earth's rotation are both necessary to produce the resulting circulation. Anti-cyclonic vorticity is generated in the upper layer by the horizontal divergence associated with upward entrainment, which is part of the estuarine circulation. The interaction between anti-cyclonic vorticity and horizontal divergence results in two regions of qualitatively different circulation, with gyre-like circulation near the bay head and uniformly seaward anti-cyclonicly sheared flow further towards the mouth. The stagnation point separating the two regions is closer to (further away from) the bay head for stronger (weaker) horizontal divergence, respectively. The vorticity and spin-up time of this circulation are-(ƒ-ω 1)/2 and h/2w 0, respectively, where ƒ is the Coriolis parameter, ω 1 is

  2. Cognitive problems related to vertebrobasilar circulation.

    Koçer, Abdulkadir


    Neurodegenerative disorders are characterized by decreased regional cerebral blood flow. Supporting this concept, both cognitive training exercises and physical activity promote blood flow increase and correlate with healthy cognitive aging. The terminal branches of the posterior circulation supply blood to areas of the brain, such as the thalamus, hippocampus, occipital lobe, and cerebellum, involved with important intellectual functions, particularly recent memory, visual-spatial functioning, and visuomotor adaptations. Amnesia and visual agnosia may be a complication of not only posterior circulation infarctions but also vertebrobasilar insufficiency (VBI) without accompanying structural infarcts. The cognitive impairment maybe a manifestation of transient attacks and may persist beyond resolution of symptoms related to ischemia. Early recognition of cognitive deficits in the VBI patient is important because several recent reports show stent placements or medical treatment may improve cognition. PMID:26738337

  3. The circulation of care in transnational families

    Laura Merla


    Full Text Available This article presents an approach to transnational family solidarity in terms of the “circulation of care”. This approach is based on a multidimensional vision of care-giving that goes beyond the personal care given to a dependent person. It takes the whole family network as its unit of analysis, and uses it to show the multiplicity of actors and the roles they play in the maintenance of transnational family solidarity in the long term. The article provides an analysis model of the institutional contexts that partially constitute the resources necessary for the circulation of care, recognising that other factors, such as the history of intra-family relationships, influence the dynamics at play.

  4. Natural circulation in pressurized water reactors

    Several analytical modelling have been done for steady-state and slow transients conditions, besides more sophisticated studies considering two and three dimensional effects in a very simple geometry. Under severe accident conditions for PWR a code to analyse natural circulation has been developed by Westinghouse. This paper discusses the problem of natural circulation in a complex geometry similar to that of nuclear power plants. A first experiment has been done at the integral test facility of 'Co-ordination of Special Projects-Ministry of Naval Affairs' (Coordenadoria para Projetos Especiais -Ministerio da Marinha, COPESP) for several flux conditions. The results obtained were compared with numerical simulations for the steady-state regime. 09 refs, 05 figs, 01 tab. (B.C.A.)

  5. Meridional circulation in turbulent protoplanetary disks

    Fromang, Sebastien; Masset, Frederic


    Based on viscous disk theory, a number of recent studies have suggested the existence of a large scale meridional circulation in protoplanetary disks. Such a flow could account for the presence of crystalline silicates, among which Calcium and Aluminium-rich Inclusions (CAIs), at large distances from the sun. This paper aims at examining whether such large scale flows exist in turbulent protoplanetary disks. High resolution global hydrodynamical and magnetohydrodynamical numerical simulations of turbulent protoplanetary disks are used to infer the properties of the flow in such disks. By performing hydrodynamic simulations using explicit viscosity, we demonstrate that our numerical setup does not suffer from any numerical artifact. The aforementioned meridional circulation is readily recovered in viscous and laminar disks. In MHD simulations, the magneto-rotational instability drives turbulence in the disks. Averaging out the turbulent fluctuations over long timescale, the results fail to show any large scale...

  6. The design of large natural circulation BWR's

    Boiling water reactors (BWR) with natural circulation are applied for capacities up to 60 MWe. Based on scale studies, however, it appears that larger production units are more efficient. It is recommended to investigate the bottlenecks in realizing larger reactors (>1000 MWe). The aim of the study on the title subject is to study to what extent the production capacity of BWRs with natural circulation can be increased. Based on data from the literature a simple analytic method has been chosen and existing BWR designs were compared. Capacities of 1300 MWe appear to be possible. These reactors will have a smaller pin diameter and a lower water supply temperature. Also steam separators with a minor pressure reduction must be available. The reliability of the stability measurement must be increased. Based on the results of this investigation the priorities for research on the design of future BWRs have been determined

  7. Formation and plasma circulation of solar prominences

    Xia, Chun


    Solar prominences are long-lived cool and dense plasma curtains in the hot and rarefied outer solar atmosphere or corona. The physical mechanism responsible for their formation and especially for their internal plasma circulation has been uncertain for decades. The observed ubiquitous down flows in quiescent prominences are difficult to interpret as plasma with high conductivity seems to move across horizontal magnetic field lines. Here we present three-dimensional numerical simulations of prominence formation and evolution in an elongated magnetic flux rope as a result of in-situ plasma condensations fueled by continuous plasma evaporation from the solar chromosphere. The prominence is born and maintained in a fragmented, highly dynamic state with continuous reappearance of multiple blobs and thread structures that move mainly downward dragging along mass-loaded field lines. The prominence plasma circulation is characterized by the dynamic balance between the drainage of prominence plasma back to the chromos...

  8. The global ocean circulation on a retrograde rotating earth

    Kamphuis, V.; Huisman, S.E.; Dijkstra, H. A.


    To understand the three-dimensional ocean circulation patterns that have occurred in past continental geometries, it is crucial to study the role of the present-day continental geometry and surface (wind stress and buoyancy) forcing on the present-day global ocean circulation. This circulation, often referred to as the Conveyor state, is characterised by an Atlantic Meridional Overturning Circulation (MOC) with a deep water formation at northern latitudes and the absence of ...

  9. Meridional circulation in turbulent protoplanetary disks

    Fromang, Sebastien; Lyra, Wladimir; Masset, Frederic


    Based on the viscous disk theory, a number of recent studies have suggested there is large scale meridional circulation in protoplanetary disks. Such a flow could account for the presence of crystalline silicates, including calcium- and aluminum-rich inclusions (CAIs), at large distances from the sun. This paper aims at examining whether such large-scale flows exist in turbulent protoplanetary disks. High-resolution global hydrodynamical and magnetohydrodynamical (MHD) numerical simulations o...

  10. Isolation of Circulating Tumor Cells by Dielectrophoresis

    Gascoyne, Peter R.C.; Sangjo Shim


    Dielectrophoresis (DEP) is an electrokinetic method that allows intrinsic dielectric properties of suspended cells to be exploited for discrimination and separation. It has emerged as a promising method for isolating circulation tumor cells (CTCs) from blood. DEP-isolation of CTCs is independent of cell surface markers. Furthermore, isolated CTCs are viable and can be maintained in culture, suggesting that DEP methods should be more generally applicable than antibody-based approaches. The aim...

  11. Water circulation forecasting in Spanish harbours

    Grifoll, Manel; Jordá, Gabriel; Sotillo, Marcos G.; Ferrer, Luis; Espino, Manuel; Sánchez-Arcilla, Agustín; Álvarez-Fanjul, Enrique


    This paper describes the first harbour circulation forecasting system implemented in Spain. The configuration design was based on previous analyses of the morphologic and hydrodynamic behaviour of three harbours: Barcelona, Tarragona and Bilbao. A nested system of oceanic models was implemented, with a scope ranging from the regional scale (with a mean horizontal resolution of 5 km) to the harbour scale (with a mean horizontal resolution of 40 m). A set of sensitivity tests was carried out in...

  12. Parallel Computing of Ocean General Circulation Model


    This paper discusses the parallel computing of the thirdgeneration Ocea n General Circulation Model (OGCM) from the State Key Laboratory of Numerical Mo deling for Atmospheric Science and Geophysical Fluid Dynamics(LASG),Institute of Atmosphere Physics(IAP). Meanwhile, several optimization strategies for paralle l computing of OGCM (POGCM) on Scalable Shared Memory Multiprocessor (S2MP) are presented. Using Message Passing Interface (MPI), we obtain super linear speedup on SGI Origin 2000 for parallel OGCM(POGCM) after optimization.

  13. Transients in a circulating fluidized bed boiler

    Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.


    Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for ca...

  14. Circulating fluidized bed boilers design and operations

    Basu, Prabir


    This book provides practicing engineers and students with insight into the design and operation of circulating fluidized bed (CFB) boilers. Through a combination of theoretical concepts and practical experience, this book gives the reader a basic understanding of the many aspects of this subject.Important environmental considerations, including solid waste disposal and predicted emissions, are addressed individually in separate chapters. This book places an emphasis on combustion, hydrodynamics, heat transfer, and material issues, and illustrates these concepts with numerous examples of pres

  15. Fluctuation Theorem in an Atmospheric Circulation Model

    Schalge, Bernd; Wouters, Jeroen; Fraedrich, Klaus; Lunkeit, Frank


    Evidence for the validity of the Fluctuation Theorem (FT) in an atmospheric Global Circulation Model is found. The model is hydrostatic with variable numbers of vertical levels and different horizontal resolutions. For finite time intervals the largest local Lyapunov exponent (LLLE) is found to be negative consistent with predictions of the FT. The effect is present for resolutions up to wave numbers l=42 (~ 250km) and 10 levels.

  16. The creation and circulation of public geographies

    Kitchin, Rob; Linehan, Denis; O'Callaghan, Cian; Lawton, Philip


    In response to the commentaries, we discuss further how social media disrupts and remakes the creation and circulation of geographical knowledges and potentially reconfigures the moral economy of the social sciences. In particular, we examine questions of what is meant by public geography, the publics which such geographies serve, alternative and complementary approaches to social media, the politics of authorship within collective blogs, the politics and mechanisms of knowledge c...

  17. Circulating somatostatin. Physiological regulator of pancreatic function?

    Gyr, K; Beglinger, C; Köhler, E; Trautzl, U; Keller, U.; Bloom, S R


    The present study was designed to determine whether somatostatin is released into the circulation in sufficient amounts to regulate exocrine and endocrine pancreatic function and to evaluate the possible role of somatostatin as a hormonal regulator of the pancreas. Mean plasma somatostatin levels (SLI) increased from 11 +/- 2 pmol liter-1 to peak concentrations of 18 +/- 2 in six healthy male volunteers after a steak meal (P less than 0.05). Infusion of somatostatin inhibited hormone-induced ...

  18. When Prostate Cancer Circulates in the Bloodstream

    Virginie Vlaeminck-Guillem


    Full Text Available Management of patients with prostate cancer is currently based on imperfect clinical, biological, radiological and pathological evaluation. Prostate cancer aggressiveness, including metastatic potential, remains difficult to accurately estimate. In an attempt to better adapt therapeutics to an individual (personalized medicine, reliable evaluation of the intrinsic molecular biology of the tumor is warranted, and particularly for all tumor sites (primary tumors and secondary sites at any time of the disease progression. As a consequence of their natural tendency to grow (passive invasion or as a consequence of an active blood vessel invasion by metastase-initiating cells, tumors shed various materials into the bloodstream. Major efforts have been recently made to develop powerful and accurate methods able to detect, quantify and/or analyze all these circulating tumor materials: circulating tumors cells, disseminating tumor cells, extracellular vesicles (including exosomes, nucleic acids, etc. The aim of this review is to summarize current knowledge about these circulating tumor materials and their applications in translational research.

  19. Acoustic streaming and Sun's meridional circulation

    Valverde, Jose Manuel


    A vast number of physical processes involving oscillations of a bounded viscous fluid are relevantly influenced by acoustic streaming. When this happens a steady circulation of fluid develops in a thin boundary adjacent to the interface. Some examples are refracted sound waves, a fluid inside a spherical cavity undergoing torsional oscillations or a pulsating liquid droplet. Steady streaming around circular interfaces consists of a hemispherically symmetric recirculation of fluid from the equatorial plane to the polar axes closely resembling the meridional circulation pattern observed in the Sun's convection zone that determines the solar cycle. In this paper, it is argued that the acoustic pulsations exhibited by the Sun would lead to acoustic streaming in the boundary of the convection zone. A simple estimation using a typical dominant frequency of 3 mHz and the observed surface oscillation amplitude yields a steady streaming velocity us ∼ 10 m s‑1, which is on the order of the meridional circulation velocity observed in the Sun's convection zone.

  20. Tropical convective transport and the Walker circulation

    J. S. Hosking


    Full Text Available We introduce a methodology to visualise rapid vertical and zonal tropical transport pathways. Using prescribed sea-surface temperatures in four monthly model integrations for 2005, we characterise preferred transport routes from the troposphere to the stratosphere in a high resolution climate model. Most efficient transport is modelled over the Maritime Continent (MC in November and February, i.e., boreal winter. In these months, the ascending branch of the Walker Circulation over the MC is formed in conjunction with strong deep convection, allowing fast transport into the stratosphere. In the model the upper tropospheric zonal winds associated with the Walker Circulation are also greatest in these months in agreement with ERA-Interim reanalysis data. We conclude that the Walker circulation plays an important role in the seasonality of fast tropical transport from the lower and middle troposphere to the upper troposphere and so impacts at the same time the potential supply of surface emissions to the tropical tropopause layer (TTL and subsequently to the stratosphere.

  1. Computer-aided design of stripline ferrite junction circulators

    Uzdy, Z.


    A general design procedure is presented for stripline Y-junction circulators employing solid dielectric between ground planes. The resonator design and impedance matching are derived in a form suitable for computer evaluation. The procedure is applicable to cases where either the circulator bandwidth or the ground plane spacing is specified. An experimental S-band switching circulator design illustrates the technique.

  2. 19 CFR 207.63 - Circulation of draft questionnaires.


    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Circulation of draft questionnaires. 207.63... SUBSIDIZED EXPORTS TO THE UNITED STATES Five-Year Reviews § 207.63 Circulation of draft questionnaires. (a) The Director shall circulate draft questionnaires to the parties for comment in each full review....

  3. Algorithms for Finding the Inverses of Factor Block Circulant Matrices


    In this paper, algorithms for finding the inverse of a factor block circulant matrix,a factor block retrocirculant matrix and partitioned matrix with factor block circulant blocks over the complex field are presented respectively. In addition, two algorithms for the inverse of a factor block circulant matrix over the quaternion division algebra are proposed.

  4. 21 CFR 868.5250 - Breathing circuit circulator.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing circuit circulator. 868.5250 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5250 Breathing circuit circulator. (a) Identification. A breathing circuit circulator is a turbine device that is attached to a closed breathing...

  5. Formation of germline chimera Gaok chicken used circulation primordial germ cells (circulation PGCs fresh and thawed

    Kostaman T


    Full Text Available Formation of germline chimeras by transfer of chicken primordial germ cells (PGCs is one of the effective techniques for preservation and regeneration of genetic resources in chickens. This study attempted to form germline chimeras of Gaok chicken buy purifying circulated PGCs of donor embryo before it is transferred to the recipient (White Leghorn chickens=WL and studied the ability of recipient embryo on survival in incubators, and hatchability. This study used 200 fertile eggs of Gaok and 90 fertile WL breed all of the eggs was incubated at 380C and 60% humidity in a portable incubator. PGCs-circulation of the blood collected Gaok embryos at stage 14-16 were taken from the dorsal aorta, and then purified by centrifugation method using nycodenz. PGCs-circulation results further purification frozen in liquid nitrogen before being transferred to the recipient embryo. The results showed that for the development of embryos transferred to the fresh circulation of PGCs-circulation as many as 25 cells can survive up to day 14, while one of the transferred of 50 and 100 cells into recipient embryos was hatched (10%. On the contrari recipient embryos that are transferred to the frozen PGCs-circulation the embryos development was shorter, and only survived until day 10th (treatment 25 cells, day 14th (treatment of 50 cells and day 17th (treatment of 100 cells. It is concluded that the amount of PGCs-circulation embryos transferred to the recipient is one factor that influence the success of the development germline chimeras.

  6. Lightweight Magnetic Cooler With a Reversible Circulator

    Chen, Weibo; McCormick, John


    A design of a highly efficient and lightweight space magnetic cooler has been developed that can continuously provide remote/distributed cooling at temperatures in the range of 2 K with a heat sink at about 15 K. The innovative design uses a cryogenic circulator that enables the cooler to operate at a high cycle frequency to achieve a large cooling capacity. The ability to provide remote/distributed cooling not only allows flexible integration with a payload and spacecraft, but also reduces the mass of the magnetic shields needed. The active magnetic regenerative refrigerator (AMRR) system is shown in the figure. This design mainly consists of two identical magnetic regenerators surrounded by their superconducting magnets and a reversible circulator. Each regenerator also has a heat exchanger at its warm end to reject the magnetization heat to the heat sink, and the two regenerators share a cold-end heat exchanger to absorb heat from a cooling target. The circulator controls the flow direction, which cycles in concert with the magnetic fields, to facilitate heat transfer. Helium enters the hot end of the demagnetized column, is cooled by the refrigerant, and passes into the cold-end heat exchanger to absorb heat. The helium then enters the cold end of the magnetized column, absorbing heat from the refrigerant, and enters the hot-end heat exchanger to reject the magnetization heat. The efficient heat transfer in the AMRR allows the system to operate at a relatively short cycle period to achieve a large cooling power. The key mechanical components in the magnetic cooler are the reversible circulator and the magnetic regenerators. The circulator uses non-contacting, self-acting gas bearings and clearance seals to achieve long life and vibration- free operation. There are no valves or mechanical wear in this circulator, so the reliability is predicted to be very high. The magnetic regenerator employs a structured bed configuration. The core consists of a stack of thin

  7. Seasonal overturning circulation in the Red Sea: 1. Model validation and summer circulation

    Yao, Fengchao


    The overturning circulation in the Red Sea exhibits a distinct seasonally reversing pattern and is studied using high-resolution MIT general circulation model simulations. In the first part of this study, the vertical and horizontal structure of the summer overturning circulation and its dynamical mechanisms are presented from the model results. The seasonal water exchange in the Strait of Bab el Mandeb is successfully simulated, and the structures of the intruding subsurface Gulf of Aden intermediate water are in good agreement with summer observations in 2011. The model results suggest that the summer overturning circulation is driven by the combined effect of the shoaling of the thermocline in the Gulf of Aden resulting from remote winds in the Arabian Sea and an upward surface slope from the Red Sea to the Gulf of Aden set up by local surface winds in the Red Sea. In addition, during late summer two processes associated, respectively, with latitudinally differential heating and increased salinity in the southern Red Sea act together to cause the reversal of the contrast of the vertical density structure and the cessation of the summer overturning circulation. Dynamically, the subsurface northward pressure gradient force is mainly balanced by vertical viscosity resulting from the vertical shear and boundary friction in the Strait of Bab el Mandeb. Unlike some previous studies, the three-layer summer exchange flows in the Strait of Bab el Mandeb do not appear to be hydraulically controlled.

  8. The stability of the thermohaline circulation in a coupled ocean-atmosphere general circulation model

    Schiller, A. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Mikolajewicz, U. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Voss, R. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany)


    The stability of the Atlantic thermohaline circulation against meltwater input is investigated in a coupled ocean-atmosphere general circulation model. The meltwater input to the Labrador Sea is increased linearly for 250 years to a maximum input of 0.625 Sv and then reduced again to 0 (both instantaneously and slowly decreasing over 250 years). The resulting freshening forces a shutdown of the formation of North Atlantic deepwater and a subsequent reversal of the thermohaline circulation of the Atlantic, filling the deep Atlantic with Antarctic bottom water. The change in the overturning pattern causes a drastic reduction of the Atlantic northward heat transport, resulting in a strong cooling with maximum amplitude over the northern North Atlantic and a southward shift of the sea-ice margin in the Atlantic. Due to the increased meridional temperature gradient, the Atlantic intertropical convergence zone is displaced southward and the westerlies in the northern hemisphere gain strength. We identify four main feedbacks affecting the stability of the thermohaline circulation: the change in the overturning circulation of the Atlantic leads to longer residence times of the surface waters in high northern latitudes, which allows them to accumulate more precipitation and runoff from the continents, which results in an increased stability in the North Atlantic.

  9. Explicit Determinants of the RFPrLrR Circulant and RLPrFrL Circulant Matrices Involving Some Famous Numbers

    Tingting Xu


    Full Text Available Circulant matrices may play a crucial role in solving various differential equations. In this paper, the techniques used herein are based on the inverse factorization of polynomial. We give the explicit determinants of the RFPrLrR circulant matrices and RLPrFrL circulant matrices involving Fibonacci, Lucas, Pell, and Pell-Lucas number, respectively.

  10. Mobile Autonomous Humanoid Assistant

    Diftler, M. A.; Ambrose, R. O.; Tyree, K. S.; Goza, S. M.; Huber, E. L.


    A mobile autonomous humanoid robot is assisting human co-workers at the Johnson Space Center with tool handling tasks. This robot combines the upper body of the National Aeronautics and Space Administration (NASA)/Defense Advanced Research Projects Agency (DARPA) Robonaut system with a Segway(TradeMark) Robotic Mobility Platform yielding a dexterous, maneuverable humanoid perfect for aiding human co-workers in a range of environments. This system uses stereo vision to locate human team mates and tools and a navigation system that uses laser range and vision data to follow humans while avoiding obstacles. Tactile sensors provide information to grasping algorithms for efficient tool exchanges. The autonomous architecture utilizes these pre-programmed skills to form human assistant behaviors. The initial behavior demonstrates a robust capability to assist a human by acquiring a tool from a remotely located individual and then following the human in a cluttered environment with the tool for future use.

  11. Effect of vegetation on the Late Miocene ocean circulation

    G. Lohmann


    Full Text Available A weak and shallow thermohaline circulation in the North Atlantic Ocean is related to an open Central American gateway and exchange with fresh Pacific waters. We estimate the effect of vegetation on the ocean general circulation using the atmospheric circulation model simulations for the Late Miocene climate. Caused by an increase in net evaporation in the Miocene North Atlantic, the North Atlantic water becomes more saline which enhances the overturning circulation and thus the northward heat transport. This effect reveals a potentially important feedback between the ocean circulation, the hydrological cycle and the land surface cover for Cenozoic climate evolution.

  12. Ethics and assisted reproduction.

    Fasouliotis, S J; Schenker, J G


    In vitro fertilization and assisted reproductive technology have made great progress during the last 20 years. Genetic material donation, human embryo cryopreservation, selective embryo reduction, preimplantation genetic diagnosis and surrogacy are currently practiced in many countries. On the other hand, embryo research is practiced only in a small number of nations, whereas human cloning has thus far been universally condemned. The rapid evolution and progress of all these techniques of assisted reproduction has revealed certain ethical issues that have to be addressed. PMID:10825637

  13. Successful thermal management of a totally implantable ventricular assist system.

    Tasai, K; Takatani, S; Orime, Y; Damm, G; Ohara, Y; Naito, K; Makinouchi, K; Mizuguchi, K; Matsuda, Y; Shimono, T


    Thermal management of the implantable ventricular assist system (VAS) is important not only from the pathophysiological point of view but also from the standpoint of system endurance. The heat distribution within the Baylor VAS was measured using different motor housing materials and environmental conditions. The temperature of the circulating water in the mock loop was set at 37 degrees and 42 degrees C. A polycarbonate motor housing was not a suitable material because of the high temperature development in the actuation system. An anodized aluminum housing demonstrated excellent heat conductivity. The surface temperature of this motor housing was 41.6 degrees C when immersed in circulating water at 42 degrees C. Heat conduction from the motor to the circulating blood revealed an effective thermal path. In the worst case, the heat flux of the motor to the circulating blood revealed an effective thermal path. In the worst case, the heat flux of the motor housing was calculated to be less than 0.062 W/cm2--an acceptable level for the surrounding tissues. PMID:8141658

  14. Gas cooled fast breeder reactor design for a circulator test facility (modified HTGR circulator test facility)


    A GCFR helium circulator test facility sized for full design conditions is proposed for meeting the above requirements. The circulator will be mounted in a large vessel containing high pressure helium which will permit testing at the same power, speed, pressure, temperature and flow conditions intended in the demonstration plant. The electric drive motor for the circulator will obtain its power from an electric supply and distribution system in which electric power will be taken from a local utility. The conceptual design decribed in this report is the result of close interaction between the General Atomic Company (GA), designer of the GCFR, and The Ralph M. Parson Company, architect/engineer for the test facility. A realistic estimate of total project cost is presented, together with a schedule for design, procurement, construction, and inspection.

  15. Gas cooled fast breeder reactor design for a circulator test facility (modified HTGR circulator test facility)

    A GCFR helium circulator test facility sized for full design conditions is proposed for meeting the above requirements. The circulator will be mounted in a large vessel containing high pressure helium which will permit testing at the same power, speed, pressure, temperature and flow conditions intended in the demonstration plant. The electric drive motor for the circulator will obtain its power from an electric supply and distribution system in which electric power will be taken from a local utility. The conceptual design decribed in this report is the result of close interaction between the General Atomic Company (GA), designer of the GCFR, and The Ralph M. Parson Company, architect/engineer for the test facility. A realistic estimate of total project cost is presented, together with a schedule for design, procurement, construction, and inspection

  16. Atmospheric General Circulation Changes under Global Warming

    Palipane, Erool

    The work in this thesis is mainly two-fold. First we study the internal variability of the general circulation and focus our study on the annular modes and how important it is to simulate the subsynoptic scales in the circulation. In the next major section we will try to understand the mechanisms of the forced response and the mechanisms leading towards the jet shift from transient evolution in Atmospheric general circulation models. In the first part, in an attempt to assess the benefit of resolving the sub-synoptic to mesoscale processes, the spatial and temporal characteristics of the Annular Modes (AMs), in particular those related to the troposphere-stratosphere interaction, are evaluated for moderate- and high-horizontal resolution simulations with a global atmospheric general circulation model (AGCM), in comparison with the ERA40 re- analysis. Relative to the CMIP-type climate models, the IFS AGCM demonstrates notable improvement in capturing the key characteristics of the AMs. Notably, the performance with the high horizontal resolution version of the model is systematically superior to the moderate resolution on all metrics examined, including the variance of the AMs at different seasons of the year, the intrinsic e-folding time scales of the AMs, and the downward influence from the stratosphere to troposphere in the AMs. Moreover, the high-resolution simulation with a greater persistence in the intrinsic variability of the SAM projects an appreciably larger shift of the surface westerly wind during the Southern Hemisphere summer under climate change. In the second part, the response of the atmospheric circulation to greenhouse gas-induced SST warming is investigated using large ensemble experiments with two AGCMs, with a focus on the robust feature of the poleward shift of the eddy driven jet. In these experiments, large ensembles of simulations are conducted by abruptly switching the SST forcing on from January 1st to focus on the wintertime circulation

  17. Unidirectional circulation in a prebiotic photochemical cycle

    Careri, Giorgio; Wyman, Jeffries


    In this brief note, we suggest the possibility that a soliton-assisted unidirectional photochemical cycle has played a role in prebiotic evolution. This suggestion is based on a model calculation which is itself based on the detection of Davydov-type soliton overtones in acetanilide.

  18. Early concepts and charts of ocean circulation

    Peterson, R. G.; Stramma, L.; Kortum, G.

    Charts of ocean currents from the late nineteenth century show that already by then the patterns of surface circulation in regions away from polar latitudes were well understood. This fundamental knowledge accumulated gradually through centuries of sea travel and had reached a state of near correctness by the time dedicated research cruises, full-depth measurements and the practical application of the dynamical method were being instituted. Perhaps because of the foregoing, many of the pioneering works, critical to establishing what the upper-level circulation is like, the majority of the charts accompanying them, and several of the groundbreaking theoretical treatments on the physics of currents, are only poorly known to present-day oceanographers. In this paper we trace Western developments in knowledge and understanding of ocean circulation from the earliest times to the late-1800s transition into the modern era. We also discuss certain peripheral advances that proved critical to the subject. The earliest known ideas, dating from the Bronze Age and described by Homer, necessarily reflect severe limitations to geographical knowledge, as well as basic human predilections toward conjecture and exaggeration in the face of inadequate information. People considered the earth to be flat and circular, with the ocean flowing like a river around it. They also believed in horrific whirlpools, a concept that persisted into the Renaissance and which would later provide subject material for modern literature. From the Greek Classical Age, we find hydrologic theories of Earth's interior being laced with subterranean channels (Socrates) and all motion deriving from a divine force forever propelling the heavens toward the west, the primum mobile (Aristotle). These ideas, particularly the latter, dominated opinions about ocean circulation into the late Renaissance. By late Antiquity mariners had very likely acquired intimate knowledge of coastal currents in the Mediterranean, but

  19. Estuarine circulation in the Taranto Seas.

    Pascalis, Francesca De; Petrizzo, Antonio; Ghezzo, Michol; Lorenzetti, Giuliano; Manfè, Giorgia; Alabiso, Giorgio; Zaggia, Luca


    The Taranto basin is a shallow water marine system in the South of Italy characterized by the presence of a lagoon environment together with a semi-enclosed bay connected to the Ionian Sea. This marine system experienced over the last few decades strong biochemical pollution and environmental degradation, and it is considered a hotspot study site for economic, ecological and scientific reasons. The aim of this study was to examine, on an annual temporal scale and with high spatial resolution, the main hydrodynamical processes and transport scales of the system by means of a 3D finite element numerical model application, adopting the most realistic forcing available. The model allowed us to assess the role played by baroclinic terms in the basin circulation, describing its estuarine nature. In particular, the main features of water circulation, salinity and temperature distribution, water renewal time and bottom stress were investigated. Our results allowed us to equate this system dynamic to that of a weakly stratified estuary, identifying the main driving sources of this mechanism. The vertical stratification over the whole year was proved to be stable, leading to a dual circulation flowing out on the surface, mainly through Porta Napoli channel, and inflowing on the bottom mainly through Navigabile channel. This process was responsible also for the renewal time faster on the bottom of the Mar Piccolo basin than the surface. Due to the great importance of the Taranto basin for what concerns sediment pollution, also the effect of currents in terms of bottom stress was investigated, leading to the conclusion that only in the inlets area the values of bottom stress can be high enough to cause erosion. PMID:26408109

  20. Seawater bicarbonate removal during hydrothermal circulation

    Proskurowski, G. K.; Seewald, J.; Sylva, S. P.; Reeves, E.; Lilley, M. D.


    High temperature fluids sampled at hydrothermal vents represent a complex alteration product of water-rock reactions on a multi-component mixture of source fluids. Sources to high-temperature hydrothermal samples include the 'original' seawater present in the recharge limb of circulation, magmatically influenced fluids added at depth as well as any seawater entrained during sampling. High-temperature hydrothermal fluids are typically enriched in magmatic volatiles, with CO2 the dominant species, characterized by concentrations of 10's-100's of mmol/kg (1, 2). Typically, the high concentration of CO2 relative to background seawater bicarbonate concentrations (~2.3 mmol/kg) obscures a full analysis of the fate of seawater bicarbonate during high-temperature hydrothermal circulation. Here we present data from a suite of samples collected over the past 15 years from high-temperature hydrothermal vents at 9N, Endeavour, Lau Basin, and the MAR that have endmember CO2 concentrations less than 10 mmol/kg. Using stable and radiocarbon isotope measurements these samples provide a unique opportunity to examine the balance between 'original' seawater bicarbonate and CO2 added from magmatic sources. Multiple lines of evidence from multiple hydrothermal settings consistently points to the removal of ~80% of the 'original' 2.3 mmol/kg seawater bicarbonate. Assuming that this removal occurs in the low-temperature, 'recharge' limb of hydrothermal circulation, this removal process is widely occurring and has important contributions to the global carbon cycle over geologic time. 1. Lilley MD, Butterfield DA, Lupton JE, & Olson EJ (2003) Magmatic events can produce rapid changes in hydrothermal vent chemistry. Nature 422(6934):878-881. 2. Seewald J, Cruse A, & Saccocia P (2003) Aqueous volatiles in hydrothermal fluids from the Main Endeavour Field, northern Juan de Fuca Ridge: temporal variability following earthquake activity. Earth and Planetary Science Letters 216(4):575-590.

  1. Physician-Assisted Suicide

    Module fourteen of the EPEC-O Self-Study Original Version focuses on the skills that the physician can use to respond both compassionately and confidently to a request, not on the merits of arguments for or against legalizing physician-assisted suicide (PAS) or euthanasia.

  2. Robot-Assisted Prostatectomy

    Full Text Available ... Darren Bruck, and I’m here at the patient’s bedside. Dr. Andy Pinon is sitting down at ... is about 10, 15-feet away from the patient. We’re performing a da Vinci robot- assisted ...

  3. Parent-Assisted Learning.

    Niedermeyer, Fred C.

    The effects of parent-monitored practice at home on pupil performance in reading were investigated. The study used as instructional vehicles the Parent-Assisted Learning Program (PAL) and the Southwest Regional Laboratory's (SWRL) First-Year Communication Skills Program. PAL was designed to enable school personnel to establish a system whereby…

  4. Robot-Assisted Prostatectomy

    Full Text Available ... it’s possible for robots to operate without the assistance of humans? Not yet. We are not quite there. The robot still needs the human to control it. The beauty of this device, it’s all ...

  5. Computer-assisted instruction

    J. Voogt; P. Fisser


    Since the early days of computer technology in education in the 1960s, it was claimed that computers can assist instructional practice and hence improve student learning. Since then computer technology has developed, and its potential for education has increased. In this article, we first discuss th

  6. Assisted Cycling Tours

    Hollingsworth, Jan Carter


    This article discusses Assisted Cycling Tours (ACT), a Westminster, Colorado based 501(c)3, non-profit that is offering the joy of bicycle tours in breathtaking, scenic locations to children and adults with developmental and physical disabilities and their families. ACT was founded by Bob Matter and his son David with a goal of opening up the…

  7. Robot-Assisted Prostatectomy

    Full Text Available ... going to the patient’s bedside to perform his duties as assistant, and I am waiting for the ... away. Okay. The patient is in what we call a “modified lithotomy position” with their legs up ...

  8. Robotic assisted andrological surgery

    Sijo J Parekattil; Ahmet Gudeloglu


    The introduction of the operative microscope for andrological surgery in the 1970s provided enhanced magnification and accuracy,unparalleled to any previous visual loop or magnification techniques.This technology revolutionized techniques for microsurgery in andrology.Today,we may be on the verge of a second such revolution by the incorporation of robotic assisted platforms for microsurgery in andrology.Robotic assisted microsurgery is being utilized to a greater degree in andrology and a number of other microsurgical fields,such as ophthalmology,hand surgery,plastics and reconstructive surgery.The potential advantages of robotic assisted platforms include elimination of tremor,improved stability,surgeon ergonomics,scalability of motion,multi-input visual interphases with up to three simultaneous visual views,enhanced magnification,and the ability to manipulate three surgical instruments and cameras simultaneously.This review paper begins with the historical development of robotic microsurgery.It then provides an in-depth presentation of the technique and outcomes of common robotic microsurgical andrological procedures,such as vasectomy reversal,subinguinal varicocelectomy,targeted spermatic cord denervation (for chronic orchialgia) and robotic assisted microsurgical testicular sperm extraction (microTESE).

  9. Robot-Assisted Prostatectomy

    Full Text Available ... actually mimicking -- these mimicking the movement of the human hand and the human wrist. Clips, please. So what Dr. Pinon has ... for robots to operate without the assistance of humans? Not yet. We are not quite there. The ...

  10. Nucla circulating atmospheric fluidized bed demonstration project


    During the fourth quarter of 1990, steady-state performance testing at the Nucla Circulating Fluidized Bed (CFB) resumed under sponsorship of the US Department of Energy. Co-sponsorship of the Demonstration Test Program by the Electric Power Research Institute (EPRI) was completed on June 15, 1990. From October through December, 1990, Colorado-Ute Electric Association (CUEA) completed a total of 23 steady-state performance tests, 4 dynamic tests, and set operating records during November and December as the result of improved unit operating reliability. Highlight events and achievements during this period of operation are presented.

  11. Effects of Buoyancy on Langmuir Circulation

    SONG Jun; SONG Jin-Bao


    Based on the Navier-Stokes equation,an equation describing the Langmuir circulation is derived by a perturbation method when the influences of Coriolis force and buoyancy force are both considered.The approach used in the analysis is similar to the works carried out by Craik and Leibovich[J.Fluid Mech.73 (1976)401],Leibovich [J.Fluid Mech.79 (1977) 715]and Huang[J.Fluid Mech.91 (1979) 191].Potential applications of the equation proposed are discussed in the area of Antarctic circumpolar current.

  12. Tropical Atmospheric Circulations with Humidity Effects

    Hsia, Chun-Hsiung; Ma, Tian; Wang, Shouhong


    The main objective of this article is to study the effect of the moisture on the planetary scale atmospheric circulation over the tropics. The modeling we adopt is the Boussinesq equations coupled with a diffusive equation of humidity and the humidity dependent heat source is modeled by a linear approximation of the humidity. The rigorous mathematical analysis is carried out using the dynamic transition theory. In particular, we obtain the same types of transitions and hence the scenario of the El Ni\\~no mechanism as described in \\cite{MW2,MW3}. The effect of the moisture only lowers slightly the magnitude of the critical thermal Rayleigh number.

  13. Transients in a circulating fluidized bed boiler

    Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.


    Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for calculating the time constants of unsteady processes are obtained.

  14. Caffeine induced changes in cerebral circulation

    While the caffeine induced cerebral vasoconstriction is well documented, the effects of oral ingestion of the drug in a dose range comparable to the quantities in which it is usually consumed and the intensity and duration of the associated reduction in cerebral circulation are unknown. Cerebral blood flow was measured via the 133Xenon inhalation technique before and thirty and ninety minutes after the oral administration of 250 mg of caffeine or a placebo, under double-blind conditions. Caffeine ingestion was found to be associated with significant reductions in cerebral perfusion thirty and ninety minutes later. The placebo group showed no differences between the three sets of cerebral blood flow values


    C. Bradea


    Full Text Available Video assisted techniques were documented by M.Gagner (1996 – video assisted parathyroidectomy, Henry (1999, Shimizu (1999, Ohgami (2000, Miccoli (2000 – video assisted parathyroidectomy and thyroidectomy. The advantage of this kind of surgery: aesthetics i.e. trying to make only small scars on the neck. Our first case of video assisted thyroidectomy was a female 50 years of age, with multinodular goiter, nodules of 2-3 cm in each lobe, admitted in our clinic in December 2008. History of the disease: 9 years; treatment: hormones pills. The refractive thyroid goiter became surgical in the last four years. The intervention was delayed because of pulmonary tuberculosis the patient suffered from. The video assited technique is inspired from Websurg site (Miccoli technique, 2007, modified by the author. We started with general anesthesia, patient lying, without hiper extension of the neck. The skin incision was on midline of the neck, 15 mm long, horizontal, at 2 cm above the inferior limit of the neck, with electric scalpel. By this skin incision we entered the thyroid space gland with classical instruments; then we introduce a 10 mm, 0 degree telescope, together with a 5 mm Ligasure grasp. After coagulation and section with Ligasure, the superior thyroid pedicle, the right thyroid lobe was dissected all around. Finally, we extracted the right thyroid lobe and then we severed with Ligasure the inferior right thyroid pedicle. The same procedure was used on the left side; it needn’t any drainage; the closure was anatomically tipical. The evolution was uneventful. The histopathological exam result was chronical Hashimoto thyroiditis. Conclusions: Video assisted thyroidectomy can be considered feasible and safe and allows for an excellent cosmetic result and has possible new promising indications such as prophylactic thyroidectomy. Not all patients are eligible for this procedure, but in selected cases it can be a valid option for the surgical

  16. Navigating "Assisted Dying".

    Schipper, Harvey


    Carter is a bellwether decision, an adjudication on a narrow point of law whose implications are vast across society, and whose impact may not be realized for years. Coupled with Quebec's Act Respecting End-of-life Care it has sharply changed the legal landscape with respect to actively ending a person's life. "Medically assisted dying" will be permitted under circumstances, and through processes, which have yet to be operationally defined. This decision carries with it moral assumptions, which mean that it will be difficult to reach a unifying consensus. For some, the decision and Act reflect a modern acknowledgement of individual autonomy. For others, allowing such acts is morally unspeakable. Having opened the Pandora's Box, the question becomes one of navigating a tolerable societal path. I believe it is possible to achieve a workable solution based on the core principle that "medically assisted dying" should be a very rarely employed last option, subject to transparent ongoing review, specifically as to why it was deemed necessary. My analysis is based on 1. The societal conditions in which have fostered demand for "assisted dying", 2. Actions in other jurisdictions, 3. Carter and Quebec Bill 52, 4. Political considerations, 5. Current medical practice. Leading to a series of recommendations regarding. 1. Legislation and regulation, 2. The role of professional regulatory agencies, 3. Medical professions education and practice, 4. Public education, 5. Health care delivery and palliative care. Given the burden of public opinion, and the legal steps already taken, a process for assisted-dying is required. However, those legal and regulatory steps should only be considered a necessary and defensive first step in a two stage process. The larger goal, the second step, is to drive the improvement of care, and thus minimize assisted-dying. PMID:27169205

  17. Causal mechanisms in airfoil-circulation formation

    Zhu, J. Y.; Liu, T. S.; Liu, L. Q.; Zou, S. F.; Wu, J. Z.


    In this paper, we trace the dynamic origin, rather than any kinematic interpretations, of lift in two-dimensional flow to the physical root of airfoil circulation. We show that the key causal process is the vorticity creation by tangent pressure gradient at the airfoil surface via no-slip condition, of which the theoretical basis has been given by Lighthill ["Introduction: Boundary layer theory," in Laminar Boundary Layers, edited by L. Rosenhead (Clarendon Press, 1963), pp. 46-113], which we further elaborate. This mechanism can be clearly revealed in terms of vorticity formulation but is hidden in conventional momentum formulation, and hence has long been missing in the history of one's efforts to understand lift. By a careful numerical simulation of the flow around a NACA-0012 airfoil, and using both Eulerian and Lagrangian descriptions, we illustrate the detailed transient process by which the airfoil gains its circulation and demonstrate the dominating role of relevant dynamical causal mechanisms at the boundary. In so doing, we find that the various statements for the establishment of Kutta condition in steady inviscid flow actually correspond to a sequence of events in unsteady viscous flow.


    Gallardo-Romero, Nadia F; Aréchiga-Ceballos, Nidia; Emerson, Ginny L; Martínez-Martínez, Flor O; Doty, Jeffrey B; Nakazawa, Yoshinori J; Rendón-Franco, Emilio; Muñoz-García, Claudia I; Villanueva-García, Claudia; Ramírez-Cid, Citlali; Gama-Campillo, Lilia M; Gual-Sill, Fernando; Aguilar-Setién, Álvaro; Carroll, Darin S


    Limited serosurveillance studies suggested that orthopoxviruses (OPXV) are widespread in the US (e.g., Raccoonpox virus, Skunkpox virus, Volepox virus) and Brazil (Vaccinia virus); however, their animal reservoir(s) remain unconfirmed. Mexican mammal diversity includes several species related to those in which evidence for OPXV infections has been found (Oryzomys, Peromyscus, Microtus, and Procyonidae). The presence of these groups of mammals in Mexico and the evidence of their possible involvement in the maintenance of OPXV in nature suggest the same or similar OPXV are circulating in Mexico. We tested 201 sera from 129 procyonids via modified enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) to estimate OPXV antibody prevalence in these animals. We detected a prevalence of 16.67% in Nasua narica (white-nosed coati), 35% in Procyon lotor (raccoon), and 30.4% in Bassariscus astutus (ring-tailed cat) when tested by either ELISA or WB. Western blot results presented protein bands consistent with the size of some OPXV immunodominant bands (14, 18, 32, 36, and 62 kDa). These results support the hypothesis that OPXV circulate in at least three genera of Procyonidae in Central and Southeast Mexico. PMID:27224209

  19. Sustaining observations of the unsteady ocean circulation.

    Frajka-Williams, E


    Sustained observations of ocean properties reveal a global warming trend and rising sea levels. These changes have been documented by traditional ship-based measurements of ocean properties, whereas more recent Argo profiling floats and satellite records permit estimates of ocean changes on a near real-time basis. Through these and newer methods of observing the oceans, scientists are moving from quantifying the 'state of the ocean' to monitoring its variability, and distinguishing the physical processes bringing signals of change. In this paper, I give a brief overview of the UK contributions to the physical oceanographic observations, and the role they have played in the wider global observing systems. While temperature and salinity are the primary measurements of physical oceanography, new transbasin mooring arrays also resolve changes in ocean circulation on daily timescales. Emerging technologies permit routine observations at higher-than-ever spatial resolutions. Following this, I then give a personal perspective on the future of sustained observations. New measurement techniques promise exciting discoveries concerning the role of smaller scales and boundary processes in setting the large-scale ocean circulation and the ocean's role in climate. The challenges now facing the scientific community include sustaining critical observations in the case of funding system changes or shifts in government priorities. These long records will enable a determination of the role and response of the ocean to climate change. PMID:25157191

  20. Measurement of cerebral circulation time in man

    A simple, inexpensive method for measuring the cerebral circulation time (CCT) was developed. The CCT was considered to be equal to the time that an intravenously injected bolus of sodium pertechnetate Tc 99m took to go from the subclavian artery to the posterior venous confluence. The dilution curves were externally recorded at these two vessels. Particular attenion was given to the curve treatment. The computer programmes were specially conceived in order to detect and, if possible, correct the experimental curve defects. Several reliability criteria were also defined in order to test the validity of each measurement. From a physiological point of view, the CCT is equal to the ratio of the global cerebral blood volume to the global cerebral blood flow. Thus, it can be widely applied in clinical research. For example, in a study of the relationship between CCT and age, sex and light cerebrovascular impairment, the technique was sensitive enough to discriminate between healthy subjects and patients suffering from-transient ischemic attack, or regressive stroke, and to show the action of a drug on the cerebral circulation in such patients. (orig.)

  1. The biology of circulating tumor cells.

    Pantel, K; Speicher, M R


    Metastasis is a biologically complex process consisting of numerous stochastic events which may tremendously differ across various cancer types. Circulating tumor cells (CTCs) are cells that are shed from primary tumors and metastatic deposits into the blood stream. CTCs bear a tremendous potential to improve our understanding of steps involved in the metastatic cascade, starting from intravasation of tumor cells into the circulation until the formation of clinically detectable metastasis. These efforts were propelled by novel high-resolution approaches to dissect the genomes and transcriptomes of CTCs. Furthermore, capturing of viable CTCs has paved the way for innovative culturing technologies to study fundamental characteristics of CTCs such as invasiveness, their kinetics and responses to selection barriers, such as given therapies. Hence the study of CTCs is not only instrumental as a basic research tool, but also allows the serial monitoring of tumor genotypes and may therefore provide predictive and prognostic biomarkers for clinicians. Here, we review how CTCs have contributed to significant insights into the metastatic process and how they may be utilized in clinical practice. PMID:26050619

  2. Reversing circulation patterns in a tropical estuary

    Valle-Levinson, Arnoldo; Bosley, Kathryn T.


    A combination of current velocity and water density measurements was used to characterize the basic patterns of water exchange in the Gulf of Fonseca, a tropical estuary on the Pacific Ocean side of Central America. The measurements were obtained during spring and neap tides in March (dry season) and June (wet season) of 2001 and consisted of profiles of current velocity and density along four transects. From mid-March to mid-April a time series of hourly surface current velocity maps was also obtained with a high-frequency radar system of two antennas. The sampling transects and the radar coverage concentrated in the portion of the estuary that has open communication with the ocean. During the dry season, water exchange at the entrance to the gulf suggested an inverse estuarine circulation that was more robust, and its dynamics were closer to geostrophy during neap than during spring tides. It is likely that salinity increased toward the tributaries of the system and then decreased within those tributaries because of the persistent influence of fresh water. In contrast, during the wet season, salinity decreased into the estuary, and the circulation resembled that of a typical estuary. In this season the fortnightly modulation of exchange flows was masked by wind effects, which also played a relevant role in the dynamics. The net volume inflows measured in both seasons suggested that the residence time of the Gulf of Fonseca varies from 2 weeks to 1 month.

  3. Formation and Plasma Circulation of Solar Prominences

    Xia, C.; Keppens, R.


    Solar prominences are long-lived cool and dense plasma curtains in the hot and rarefied outer solar atmosphere or corona. The physical mechanism responsible for their formation and especially for their internal plasma circulation has been uncertain for decades. The observed ubiquitous downflows in quiescent prominences are difficult to interpret because plasma with high conductivity seems to move across horizontal magnetic field lines. Here we present three-dimensional numerical simulations of prominence formation and evolution in an elongated magnetic flux rope as a result of in situ plasma condensations fueled by continuous plasma evaporation from the solar chromosphere. The prominence is born and maintained in a fragmented, highly dynamic state with continuous reappearance of multiple blobs and thread structures that move mainly downward, dragging along mass-loaded field lines. The circulation of prominence plasma is characterized by the dynamic balance between the drainage of prominence plasma back to the chromosphere and the formation of prominence plasma via continuous condensation. Plasma evaporates from the chromosphere, condenses into the prominence in the corona, and drains back to the chromosphere, establishing a stable chromosphere–corona plasma cycle. Synthetic images of the modeled prominence with the Solar Dynamics Observatory Atmospheric Imaging Assembly closely resemble actual observations, with many dynamical threads underlying an elliptical coronal cavity.

  4. Nanocrystalline gadolinium iron garnet for circulator applications

    Due to high resistivity and low microwave losses, gadolinium iron garnets (GdIG) are useful materials for non-reciprocal devices such as circulators or isolators. Keeping the miniaturization and cost reduction in mind, the trend is to modify the conventional methods of preparation of samples. In this connection we have synthesized nanocystalline GdIG by using the Microwave Hydrothermal method at 160 °C/45 min. As synthesized powders were characterized by using X-ray diffraction (XRD), transmission electron microscopy and Fourier Transform Infrared Spectroscopy. XRD patterns show the formation of a garnet phase with crystallite size varying between 19 nm and 40 nm. Differential Thermal Analysis studies were also carried out on the nanopowders. The powders were densified at a lower sintering temperature of 1100 °C/45 min using a microwave sintering method. The sintered samples were characterized by XRD and atomic force microscopy. The frequency dependence of complex permittivity and ferromagnetic resonance were measured in the Ka band frequency (27–40 GHz). Magnetic properties were also measured at room temperature. - Highlights: ► GdIG ferrites were synthesized using the microwave hydrothermal method. ► Densification of the GdIG samples was done at a low temperature of 1100 °C/45 min. ► Our samples possess low dielectric constant and loss at a Ka band frequency. ► Nanocrystalline GdIG samples for circulator application have been tested.

  5. Circulator performance during THTR trial and post-commissioning operation

    Since the first trial runs the circulators have scored more than two years of trouble-free operation during the trial operation and commissioning phases. At no time the circulators gave reason for plant shutdown. The circulators which had been ordered in 1972 were delivered already ten years ago. Only two out of the six circulators were tested on a test stand in the workshop. In 1987 another identical standby circulator was supplied in support of an initiative to increase the basic conditions of plant availability. In view of the excellent result of the test period it can be assumed that the standby circulator will never be required. The 6 circulators equipped with oil bearings are each provided with a separate oil system whose pressure corresponds to that of the primary system. Safety aspects resulting from licensing requirements led to extensive efforts regarding the oil systems. These efforts involve also that part of the buffer helium flow which is released from the circulators with the oil draining from the bearings. During the commissioning phase it has been verified that the internal barrier helium system of the circulators is capable to retain the lubrication oil inventory within the circulator range, even if the external make-up barrier helium supply from the helium purification system is shut off. Thus it is ensured that leakage of oil into the primary helium system is ruled out by the shaft seal system. Further development work on the circulators is currently being continued for the only reason that active magnetic bearings permit vertical arrangement of the circulators with the impeller at the lower end without requiring the operation of an extremely complicated and expensive oil system. Apart from that, the experience gained with the THTR operation did not result in any changes in the design characteristics which had already been used in the AVR circulators. 7 refs, 13 figs

  6. SuperAssist: Personal assistants for cooperative healthcare treatment

    Haan, G. de; Mast, C.A.P.G. van der; Blanson Henkemans, O.; Neerincx, M.A.


    Human-computer interaction, tele-medicine, supervision, personalization, ambient intelligence, health care, personal assistants, cooperative problem-solving. ABSTRACT This paper describes the research plans in the SuperAssist project, introducing personal assistants in the care of diabetes patients,

  7. Society for Assisted Reproductive Technology

    The Society for Assisted Reproductive Technology PATIENTS Patient Information What Is SART? Risks of IVF Third Party Reproduction A ... Read Article View All News ©1996 - 2016 SART, Society for Assisted Reproductive Technology . All Rights Reserved. ASRM/ ...

  8. Preparing for Assisted Reproductive Technology

    ... CDC Cancel Submit Search The CDC Assisted Reproductive Technology (ART) Note: Javascript is disabled or is not ... visit this page: About . Assisted Reproductive Technology (ART) What Is ART Patient Resources Preparing for ...

  9. Rehabilitative and Assistive Technology: Overview

    ... Clinical Trials Resources and Publications Rehabilitative and Assistive Technology: Overview Skip sharing on social media links Share this: Page Content Rehabilitative and assistive technology refers to tools, equipment, or products that can ...

  10. A new analytical model for conduction heating during the SAGD circulation phase

    Duong, A.N. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[ConocoPhillips Canada Resources Corp., Calgary, AB (Canada); Tomberlin, T.A. [ConocoPhillips Canada Resources Corp., Calgary, AB (Canada); Cyrot, M. [Total E and P Canada Ltd., Calgary, AB (Canada)


    The steam assisted gravity drainage (SAGD) process has become the common procedure to recover bitumen from Alberta's oilsands. Inter-well communication must be initiated during the start-up phase of a SAGD process. The shape of an initial steam chamber that develops during the circulation phase influences the efficiency of bitumen recovery. As such, the heating conformance distributed along the horizontal wellbores must be well understood. The duration of the start-up phase varies with the characteristics of the oilsand formation and the distance between the wellbores, but it is typically a month to several months. This paper presented a newly developed analytical model that predicts the initial steam chamber. The model improves bitumen recovery efficiency by predicting the mid-point temperature front and heating efficiency of a wellpair during the SAGD circulation phase. The Excel-based model uses the exponential integral solution for radial heating in a long cylinder and superposition in space for multi-heating sources. It can predict the temperature profile if the steam temperatures or pressures are known during the circulation period. Wellbore modeling that includes any variation in distances between the wellbores is critical to both circulation time and heating conformance. This model has an advantage over numerical simulation in terms of reducing computational time and accurately modelling any variation in distance between wellbores. The results can be optimized under various operational conditions, wellbore profiles, tubing sizes and convection flow effects. This easy to use model is currently being used by ConocoPhillips Canada to optimize, predict and guide oilsands projects during the start-up phase of a SAGD process. 5 refs., 13 figs.

  11. Effect of Vegetation on the Late Miocene Ocean Circulation

    Gerrit Lohmann


    Full Text Available We examine the role of the vegetation cover and the associated hydrological cycle on the deep ocean circulation during the Late Miocene (~10 million years ago. In our simulations, an open Central American gateway and exchange with fresh Pacific waters leads to a weak and shallow thermohaline circulation in the North Atlantic Ocean which is consistent with most other modeling studies for this time period. Here, we estimate the effect of a changed vegetation cover on the ocean general circulation using atmospheric circulation model simulations for the late Miocene climate with 353 ppmv CO2 level. The Late Miocene land surface cover reduces the albedo, the net evaporation in the North Atlantic catchment is affected and the North Atlantic water becomes more saline leading to a more vigorous North Atlantic Deep Water circulation. These effects reveal potentially important feedbacks between the ocean circulation, the hydrological cycle and the land surface cover for Cenozoic climate evolution.

  12. Physician Assistant Genomic Competencies.

    Goldgar, Constance; Michaud, Ed; Park, Nguyen; Jenkins, Jean


    Genomic discoveries are increasingly being applied to the clinical care of patients. All physician assistants (PAs) need to acquire competency in genomics to provide the best possible care for patients within the scope of their practice. In this article, we present an updated version of PA genomic competencies and learning outcomes in a framework that is consistent with the current medical education guidelines and the collaborative nature of PAs in interprofessional health care teams. PMID:27490287

  13. Computer-assisted psychotherapy

    Wright, Jesse H.; Wright, Andrew S.


    The rationale for using computers in psychotherapy includes the possibility that therapeutic software could improve the efficiency of treatment and provide access for greater numbers of patients. Computers have not been able to reliably duplicate the type of dialogue typically used in clinician-administered therapy. However, computers have significant strengths that can be used to advantage in designing treatment programs. Software developed for computer-assisted therapy gen...

  14. Computer assisted mathematical programming

    Lucas, CA; Mitra, G


    A Computer Assisted Mathematical Programming (Modelling) System (CAMPS) is described in this paper. The system uses program generator techniques for model creation and contrasts with earlier approaches which use a special purpose language to construct models. Thus no programming skill is required to formulate a model. In designing the system we have first analysed the salient components of the mathematical programming activity. A mathematical programming model is usually constructed by progre...

  15. Personal digital assistants

    Wiggins III, Richard H.


    Personal digital assistant sales are growing exponentially, and as medical technology advances the amount of information available becomes staggering, making a handheld device, with the ability to store a great amount of information, progressively more valuable to health care providers. Mobile computing allows for a great deal of knowledge in a small package, creating a “walking library” with a mobile collection of data always accessible. There are many diverse types of PDAs, and this article...

  16. Robot Assisted Laser Osteotomy

    Burgner, Jessica


    In the scope of this thesis world's first robot system was developed, which facilitates osteotomy using laser in arbitrary geometries with an overall accuracy below 0.5mm. Methods of computer and robot assisted surgery were reconsidered and composed to a workflow. Adequate calibration and registration methods are proposed. Further a methodology for transferring geometrically defined cutting trajectories into pulse sequences and optimized execution plans is developed.


    Lantero, Caroline


    Euthanasia and assisted suicide are not part of French laws of bioethics and lack, for the time being, definition and normative framework other than their criminal prosecution. To transform them into a right, these concepts certainly call for an ethical and legal debate. This paper aims to question the ideas to be considered, the conceptual bases and normative tools that may be useful to the discussion. PMID:27356358

  18. Virtual personal assistant

    Imrie, Peter; Bednar, Peter


    Abstract This report discusses ways in which new technology could be harnessed to create an intelligent Virtual Personal Assistant (VPA) with a focus on user-based information. It will look at examples of intelligent programs with natural language processing that are currently available, with different categories of support, and examine the potential usefulness of one specific piece of software as a VPA. This engages the ability to communicate socially through natural language processing, hol...

  19. Optimization and assistance operations

    The purpose of this article is to answer this question: what does optimization mean in the frame of an assistance operation. Two points have been developed: the first one is devoted to a broad training and sensitizing for the persons susceptible to participate to these interventions, the second one is the preparation of operations: it is possible to develop optimization from information feedback. (N.C.)

  20. Computer assisted radiology

    CAR'89 is intended to serve as a forum for discussion between experts from the medical sciences e.g., radiology, radiotherapy, nuclear medicine, orthopaedia, cardiology, neurology and surgery and professionals from the computer and physical sciences. Computer assisted radiological diagnosis, orthopaedics, therapy, and planning are the main subjects of the symposium and the panel discussion. The state of the art and research results in the area of CAR are evaluated. (DG)

  1. Assistance From A Distance


    China joins international relief efforts in Haiti with a powerful sense of mission How long does it take to ready assistance and travel some 15,000 km around the globe to provide a helping hand amid one of the worst earth-quakes in modern history? The answer might surprise you. Less than 36 hours after seismic shocks leveled much of Haiti on January

  2. INPO Assistance Activities: Human Resources

    The Institute of Nuclear Power Operations (INPO) has a number of ongoing activities designed to provide assistance to our members in the human resources area. These include the Educational Assistance Program and the ongoing facilitation of information exchange through Nuclear Network and INPO publications. INPO will continue to seek ways to assist its member utilities

  3. Human cerebral circulation. Positron emission tomography studies

    We reviewed the literature on human cerebral circulation and oxygen metabolism, as measured by positron emission tomography (PET), with respect to normal values and of regulation of cerebral circulation. A multicenter study in Japan showed that between-center variations in cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) values were not considerably larger than the corresponding within-center variations. Overall mean±SD values in cerebral cortical regions of normal human subjects were as follows: CBF=44.4±6.5 ml/100 ml/min; CBV=3.8±0.7 ml/100 ml; OEF=0.44±0.06; CMRO2=3.3±0.5 ml/100 ml/min (11 PET centers, 70 subjects). Intrinsic regulation of cerebral circulation involves several factors. Autoregulation maintains CBF in response to changes in cerebral perfusion pressure; chemical factors such as PaCO2 affect cerebral vascular tone and alter CBF; changes in neural activity cause changes in cerebral energy metabolism and CBF; neurogenic control of CBF occurs by sympathetic innervation. Regional differences in vascular response to changes in PaCO2 have been reported, indicating regional differences in cerebral vascular tone. Relations between CBF and CBV during changes in PaCO2 and during changes in neural activity were in good agreement with Poiseuille's law. The mechanisms of vascular response to neural activation and deactivation were independent on those of responses to PaCO2 changes. CBV in a brain region is the sum of three components: arterial, capillary and venous blood volumes. It has been reported that the arterial blood volume fraction is approximately 30% in humans and that changes in human CBV during changes in PaCO2 are caused by changes in arterial blood volume without changes in venous blood volume. These findings should be considered in future studies of the pathophysiology of cerebrovascular diseases. (author) 136 refs

  4. Microsurgical anatomy of the posterior circulation

    Pai Balaji


    Full Text Available Context: The microsurgical anatomy of the posterior circulation is very complex and variable. Surgical approaches to this area are considered risky due to the presence of the various important blood vessels and neural structures. Aims: To document the microsurgical anatomy of the posterior circulation along with variations in the Indian population. Materials and Methods: The authors studied 25 cadaveric brain specimens. Microsurgical dissection was carried out from the vertebral arteries to the basilar artery and its branches, the basilar artery bifurcation, posterior cerebral artery and its various branches. Measurements of the outer diameters of the vertebral artery, basilar artery and posterior cerebral artery and their lengths were taken. Results: The mean diameter of the vertebral artery was 3.4 mm on the left and 2.9 mm on the right. The diameter of the basilar artery varied from 3-7 mm (mean of 4.3 mm. The length varied from 24-35 mm (mean of 24.9 mm. The basilar artery gave off paramedian and circumferential perforating arteries. The origin of the anterior inferior cerebellar artery (AICA varied from 0-21 mm (mean 10.0 mm from the vertebrobasilar junction. The diameter of the AICA varied from being hypoplastic i.e., < 0.5 mm to 2 mm (mean 1.0 mm. The superior cerebellar artery (SCA arises very close to the basilar bifurcation, in our series (1-3 mm from the basilar artery bifurcation. The diameter of the SCA varied from 0.5-2.5 mm on both sides. The posterior cerebral artery (PCA is divided into four segments. The PCA gave rise to perforators (thalamoperforators, thalamogeniculate arteries, circumflex arteries and peduncular arteries, medial posterior choroidal artery, lateral posterior choroidal artery and cortical branches. In 39 specimens the P1 segment was found to be larger than the posterior communicating artery, in six specimens it was found to be equal to the diameter of the posterior communicating artery and in five specimens it

  5. Steer assistance for teleoperation

    Pape, Olivier; Houbloup, Philippe; Leveque, Stephane


    Giat Industries, expert in combat system, designs and integrates the technologies (electrical network, mechanical design, ergonomic and mobility command and control) for the French military and civil robotic. One of the main problems of current robotics is to treat the lack of operator's perception due to teleoperation. The article details the assistance for the steer control part of mobility command and control. The purpose of the assistance is to secure the vehicle, to insure the continuity of the command (in particular for tracked vehicle equipped of hydrostatic steering group), and to adapt the command (to use all the range of the command even at high speed and to adapt the speed to the desired curve). The advantage of the system presented in the article is to filter the order first and to transmit to the actuators only safe orders preserving the vehicle. This approach transforms the telepilot's order watching and correction problem, to a telepilot's order filtering problem. We pass here, from a logical "a posteriori" to a logical of "a priori" processing. The assistance includes: a model of the dynamic behavior of the vehicle and an open loop, some feed forward with appropriate filters and a closed loop. The article presents the result of the command studies from time simulation to "man on the loop" simulation. This system, at present time applied to the French Observation Robot demonstrator SYRANO (developped for the DGA-French Defence Procurement Agency), is the subject of a patent.

  6. Hadley Circulation Response to Orbital Precession. Part I: Aquaplanets

    Merlis, Timothy M.; Schneider, Tapio; Bordoni, Simona; Eisenman, Ian


    The response of the monsoonal and annual-mean Hadley circulation to orbital precession is examined in an idealized atmospheric general circulation model with an aquaplanet slab-ocean lower boundary. Contrary to expectations, the simulated monsoonal Hadley circulation is weaker when perihelion occurs at the summer solstice than when aphelion occurs at the summer solstice. The angular momentum balance and energy balance are examined to understand the mechanisms that produce this result. That th...

  7. The ElGamal cryptosystem over circulant matrices

    Mahalanobis, Ayan


    In this paper we study extensively the discrete logarithm problem in the group of non-singular circulant matrices. The emphasis of this study was to find the exact parameters for the group of circulant matrices for a secure implementation. We tabulate these parameters. We also compare the discrete logarithm problem in the group of circulant matrices with the discrete logarithm problem in finite fields and with the discrete logarithm problem in the group of rational points of an elliptic curve.

  8. Methodical Approaches to Diagnostics of Circulating Assets of an Enterprise

    Oleksandrenko Iryna V.


    Full Text Available The article is devoted to the study of theoretical and practical grounds of diagnostics of circulation assets. It identifies essence of circulating assets and their types. It shows main stages of diagnostics of circulating assets and systemises main tasks, which should be solved in the process of diagnostics. It specifies methods used in the process of diagnostics of the enterprise circulating assets. It identifies and shows the order of calculation of indicators of efficiency of use of circulating assets. Based on the proposed indicators of efficiency of use of circulating assets the article identifies methodical grounds of carrying out their factor analysis. The provided methods of conduct of a factor analysis of the circulating assets turnover ration allows finding out how growth (reduction of components of circulating assets influenced the change of the effective indicator. Based on the results of diagnostics of circulating assets the article shows main managerial decisions that could be taken into account. The reflected theoretical and practical aspects of diagnostics are a foundation of conduct of diagnostics of property and the financial state of the enterprise in general.

  9. r-BlockPermutation Factor Circulant Matrix and Inverse Matrix

    SUN Ji zhong; QIN Keyun; Hu, Yan


    The concept of r-block permutation factor circulant matrix is presented. The characteristics of r-block permutation factor circulant matrix are discussed by Kronecker. The interchange ability of r-block permutation factor circulant matrix has been demonstrated, that is AB=BA. The calculation method of matrix determinant and the sufficient condition of nonsingular matrix based on the diagonalization of circulant matrices are given. Finally, the method of inverse matrix is given in r-blo...

  10. Optimization of reverse circulation bit based on field experiment

    Hong REN; Kun YIN; Kun BO


    By field experiment in Sandaozhuang W-Mo mining area in Luanchuan of Henan Province, the authors analyzed the Experimental result of reverse circulation bit on the basis of different structures and obtained the following conclusion: the design parameter of reverse circulation bit, the number, diameter and angle of the spurt hole can influence on the reverse circulation effect. The bit with inner spurt hole is better obviously than that one without inner spurt hole in reverse circulation, one or two right and the best choice of inner spurt hole is that the diameter is Φ8, the angle is 30° dip up and the suitable number is two to three.