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1

Familial unilateral deafness and delayed endolymphatic hydrops  

British Library Electronic Table of Contents (United Kingdom)

Delayed endolymphatic hydrops (DEH) is a unique disorder characterized by fluctuating otologic symptoms in the setting of preexisting unilateral deafness. The symptoms include aural fullness, fluctuating hearing, and/or episodes of vertigo similar to those observed in Meniere disease and may occur ipsilateral or contralateral to the previously deafened ear. In most reported cases, the unilateral deafness has been a profound sensorineural hearing loss with a sudden onset that has been variously attributed to bacterial or viral labyrinthitis, acoustic or cranial trauma, otosclerosis, and congenital CMV infection. Familial occurrence of the syndrome has not previously been reported in the literature. In this report, we describe two possible familial instances of delayed DEH. These patients ra...

2007-01-01

2

Hearing loss in children and adults  

UK PubMed Central (United Kingdom)

ObjectiveThe purpose of this study was to characterize the sensorineural hearing losses of a group of children and adults along three parameters important to the...Full Text Available

2003-06-01

3

Optical Coherence Tomography Findings in Idiopathic Macular Holes  

UK PubMed Central (United Kingdom)

Purpose. To describe the characteristics of idiopathic macular holes (MH) on optical coherence tomography (OCT) and correlate OCT with clinical assessment. Design....Full Text Available

2011-01-01

4

Nonchylous idiopathic pleural effusion in the newborn  

UK PubMed Central (United Kingdom)

Congenital isolated pleural effusion is a rare cause of respiratory distress in neonates. It is usually chylous. Herein, we report a rare case of nonchylous congenital idiopathic pleural effusion.

2011-01-01

5

Idiopathic (primary) achalasia  

UK PubMed Central (United Kingdom)

Idiopathic achalasia is a primary esophageal motor disorder characterized by esophageal aperistalsis and abnormal lower esophageal sphincter (LES) relaxation in response to deglutition. It is a rare...Full Text Available

6

Ultrasonography and color Doppler of proximal gluteal enthesitis in juvenile idiopathic arthritis: a descriptive study  

UK PubMed Central (United Kingdom)

BackgroundThe presence of enthesitis (insertional inflammation) in patients with juvenile idiopathic arthritis (JIA) is difficult to establish clinically and may influence classification...Full Text Available

7

The use of etoricoxib to treat an idiopathic stabbing headache: a case report  

UK PubMed Central (United Kingdom)

According to the International Headache Society, idiopathic stabbing headache (ISH), an indomethacin-responsive headache syndrome, is a paroxysmal disorder of short duration manifested as head pain...Full Text Available

8

Immature cell populations and an erythropoiesis gene-expression signature in systemic juvenile idiopathic arthritis: implications for pathogenesis  

UK PubMed Central (United Kingdom)

IntroductionPrevious observations suggest that active systemic juvenile idiopathic arthritis (sJIA) is associated with a prominent erythropoiesis gene-expression signature. The aim...Full Text Available

2010-01-01

9

Idiopathic venous thromboembolism and thrombophilia  

UK PubMed Central (United Kingdom)

During the past decade idiopathic venous thromboembolism has become a separate entity, a chronic illness which has required prolonged anticoagulation and other prevention strategies to avoid recurrences....Full Text Available

2011-02-15

10

Combined photodynamic therapy and intravitreal bevacizumab for idiopathic polypoidal choroidal vasculopathy: one-year follow-up  

UK PubMed Central (United Kingdom)

ObjectiveTo report the efficacy and safety of combined photodynamic therapy (PDT) and intravitreal bevacizumab (IVB) injection in the treatment of idiopathic polypoidal choroidal...Full Text Available

2010-01-01

11

Abnormalities of GATA-1 in Megakaryocytes from Patients with Idiopathic Myelofibrosis  

UK PubMed Central (United Kingdom)

The abnormal megakaryocytopoiesis associated with idiopathic myelofibrosis (IM) plays a role in its pathogenesis. Because mice with defective expression of transcription factor GATA-1 (GATA-1low...Full Text Available

2005-09-01

12

Pulmonary vein ablation for idiopathic atrial fibrillation: six month outcome of first procedure in 100 consecutive patients  

UK PubMed Central (United Kingdom)

Objectives: To report six month outcome in patients undergoing their first pulmonary vein ablation procedure for idiopathic atrial fibrillation (AF) at a “non-pioneering”...Full Text Available

2005-01-01

13

Investigation of a syndrome of sudden death, splenomegaly, and small intestinal hemorrhage in farmed deer  

UK PubMed Central (United Kingdom)

AbstractA newly recognized syndrome, characterized by sudden death of farmed deer that are in good to excellent nutritional condition, with lesions of small intestinal mucosal hemorrhage...Full Text Available

2005-08-01

14

Positional Stretching of the Coracohumeral Ligament on a Patient with Adhesive Capsulitis: A Case Report  

UK PubMed Central (United Kingdom)

Idiopathic frozen shoulder is a common medical diagnosis for patients seeking physical therapy. Radiographic and surgical evidence exists that describes the coracohumeral ligament (CHL) as a major contributor...Full Text Available

2009-01-01

15

Paradoxical function for the receptor for advanced glycation end products in mouse models of pulmonary fibrosis  

UK PubMed Central (United Kingdom)

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor survival. The identification of therapeutic targets is essential to improving outcomes. Previous studies found that expression...Full Text Available

2011-03-31

16

Increased wind-up to heat pain in women with a childhood history of functional abdominal pain  

UK PubMed Central (United Kingdom)

Idiopathic or functional abdominal pain (FAP) is common in school-age children and typically reflects a functional gastrointestinal disorder (FGID). FGIDs in adults have been distinguished by...Full Text Available

2011-04-01

17

Disability and Psychologic Distress in Patients with Nonspecific and Specific Arm Pain  

UK PubMed Central (United Kingdom)

Psychological illness influences the experience and expression of pain and disability. We tested three null hypotheses: (1) patients with nonspecific pain (medically unexplained and idiopathic) and...Full Text Available

2008-11-01

18

Hydrodynamics of swirling flow in a circular tube with sudden increase in cross-section and of the flow through a Borda mouthpiece  

Energy Technology Data Exchange (ETDEWEB)

By applying the mass, momentum, and angular momentum conservation laws and the maximum flow rate principle to swirling, effectively inviscid, incompressible flows in a circular tube with a sudden expansion and the direct-flow and reversed-flow Borda mouthpieces the dependence of the flow rate coefficient and mechanical energy losses on the radius ratio and nondimensional circulation is obtained. Several calculating approaches with potential and helical motion are introduced and investigated. In the case of helical motion, as the swirl decreases the axial core of the flow is found to close with a sudden change of the flow parameters.

1994-11-01

19

Ranking Hearing Aid Input-Output Functions for Understanding Low-, Conversational-, and High-Level Speech in Multitalker Babble  

Science.gov (United States)

Purpose: To determine the rankings of 6 input-output functions for understanding low-level, conversational, and high-level speech in multitalker babble without manipulating volume control for listeners with normal hearing, flat sensorineural hearing loss, and mildly sloping sensorineural hearing loss. Method: Peak clipping, compression limiting, and 4 wide dynamic range compression (WDRC) input-output functions were compared in a repeated-measure design. Interactions among the compression characteristics were minimized. Speech and babble were processed and recorded at 3 input levels: 45, 65, and 90 dB sound pressure level. Speech recognition of 3 groups of listeners (n = 6/group) was tested for speech processed by each input-output function and at each input level. Results: Input-output functions that made low-level speech audible and high-level speech less distorted by avoiding peak clipping or severe compression yielded higher speech ...

2007-04-01

20

Pirfenidone in idiopathic pulmonary fibrosis: the CAPACITY program  

British Library Electronic Table of Contents (United Kingdom)

Idiopathic pulmonary fibrosis is the most lethal form of diffuse lung fibrosis, killing approximately half of those affected within 2-3 years of diagnosis. Until recently, no therapies had been shown to have an impact on disease progression. The Clinical Studies Assessing Pirfenidone (Esbriet) in IPF: Research of Efficacy and Safety Outcomes (CAPACITY) program comprised two almost identical double-blind placebo-controlled studies assessing the effects of pirfenidone on change in forced vital capacity, the primary end point, over a 72-week period. One of these studies was positive, matching in magnitude the benefit seen in two previous positive Japanese studies. The other study did not meet its primary end point but positive trends were consistent in this and a number of secondary end point...

2011-01-01

 
 
 
 
21

Preoperative factors predictive of postoperative decimal visual acuity ? 1.0 following surgical treatment for idiopathic epiretinal membrane  

UK PubMed Central (United Kingdom)

Purpose:To report the preoperative best-corrected visual acuity (BCVA) and foveal thickness (FT) values that lead to a postoperative decimal BCVA of ≥1.0 after surgical removal...Full Text Available

2011-01-01

22

An evaluation of the utility of routine laboratory monitoring of juvenile idiopathic arthritis (JIA) patients using non-steroidal anti-inflammatory drugs (NSAIDs): a retrospective review  

UK PubMed Central (United Kingdom)

BackgroundNo consensus evidence-based guidelines for the routine laboratory monitoring of children with JIA receiving non-steroidal anti-inflammatory drugs (NSAIDs) exist. The purpose...Full Text Available

23

Retrospective investigation of sudden maternal weight loss as an indicator of impending parturition in the term gravida: A pilot study  

British Library Electronic Table of Contents (United Kingdom)

Summary The aim of the study was to perform a retrospective review of records to test a possible significant association between sudden, modest weight loss (t-test and Wilcoxon test p values were 0.95 and 0.61, respectively. A Kolmogorov-?Smirnov test p value was 0.2139. A one-half standard deviation difference in time to delivery, approximately 2.5 days, was detectable with 0.95 probability. It was concluded that these data may be the first time this question has been investigated and provide evidence that sudden, modest weight loss at the end of pregnancy is not associated with shorter time to onset of natural labour.

2011-01-01

24

Stressed-Induced TMEM135 Protein Is Part of a Conserved Genetic Network Involved in Fat Storage and Longevity Regulation in Caenorhabditis elegans  

UK PubMed Central (United Kingdom)

Disorders of mitochondrial fat metabolism lead to sudden death in infants and children. Although survival is possible, the underlying molecular mechanisms which enable this outcome have not yet been...Full Text Available

25

Spontaneous cervical epidural hematoma: Report of a case managed conservatively  

UK PubMed Central (United Kingdom)

Spontaneous spinal epidural hematoma is a rare cause of acute spinal cord compression. A 25-year-old male presented with a history of sudden onset of complete quadriplegia with sensory loss below the...Full Text Available

2008-07-01

26

Millions of battery stores; Millionen kleine Speicher  

Energy Technology Data Exchange (ETDEWEB)

It is still a vision at the time being, but wind power and electric cars may complement each other efficiently: Batteries are charged when the power demand of the grid has been saturated. In case of sudden demand peaks, the stored power is transmitted back into the grid. (orig.)

2007-07-15

27

Medico-legal autopsy in postoperative hemodynamic collapse following coronary artery bypass surgery  

UK PubMed Central (United Kingdom)

Sudden unexpected postoperative hemodynamic collapse with a high mortality develops in 1–3% of patients undergoing coronary artery bypass surgery (CABG). The contribution of surgical graft complications...Full Text Available

2011-03-01

28

Is alopecia areata an autoimmune-response against melanogenesis-related proteins, exposed by abnormal MHC class I expression in the anagen hair bulb?  

UK PubMed Central (United Kingdom)

The etiology of alopecia areata (AA), a putative autoimmune disease characterized by sudden hair loss, has remained obscure. It is not understood, how the characteristic inflammatory infiltrate that...Full Text Available

1993-11-01

29

Forecasting changes in amphibian biodiversity: aiming at a moving target  

UK PubMed Central (United Kingdom)

Amphibian population declines and sudden species' extinctions began to be noted at the beginning of the 1980s. Understanding the causes of the losses is hampered by our poor knowledge of the amphibian...Full Text Available

2005-02-28

30

Environmental tobacco smoke and sudden infant death syndrome: a review  

British Library Electronic Table of Contents (United Kingdom)

Environmental tobacco smoke (ETS), containing the developmental neurotoxicant, nicotine, is a prevalent component of indoor air pollution. Despite a strong association with active maternal smoking and sudden infant death syndrome (SIDS), information on the risk of SIDS due to prenatal and postnatal ETS exposure is relatively inconsistent. This literature review begins with a discussion and critique of existing epidemiologic data pertaining to ETS and SIDS. It then explores the biologic plausibility of this association, with comparison of the known association between active maternal smoking and SIDS, by examining metabolic and placental transfer issues associated with nicotine, and the biologic responses and mechanisms that may follow exposure to nicotine. Evidence indicates that prenatal ...

2006-01-01

31

Use of sodium chromate Cr/sub 51/ in diagnosing childhood idiopathic pulmonary hemosiderosis  

Energy Technology Data Exchange (ETDEWEB)

The diagnosis of idiopathic pulmonary hemosiderosis (IPH) may be elusive. A 6-year-old boy had microcytic hypochromic anemia and a hemolytic component. Hemosiderin-laden macrophages were not found in the gastric aspirate. He had no pulmonary signs or symptoms. Extensive hematologic and roentgenologic investigations failed to reveal the cause of the anemia. Quantitative serial scintigraphic scanning showed significant (35%) pulmonary sequestration of autologous erythrocytes labeled with sodium chromate Cr51. The half-life of the RBCs was moderately decreased (half-life, 15 days; normal, 25 to 35 days). An open-lung biopsy spece Cr51. The half-life of the RBCs was moderately decreased (half-life, 15 days; normal, 25 to 35 days). An open-lung biopsy specimen confirmed the diagnosis of IPH. A diagnosis of IPH should be considered when children have iron deficiency anemia and pulmonary signs or symptoms. Organ sequestration studies may be helpful in equivocal cases.

1984-08-01

32

Idiopathic renal hematuria in a military working dog.  

Science.gov (United States)

A 1.5-year-old male Belgian Malinosis Military Working Dog presented with a 1-month history of intermittent hematuria. Diagnostic ultrasound and contrast radiography demonstrated large blood clots in the urinary bladder and a filling defect in the right renal pelvis. At surgery, clotted blood was present in the right ureter and bladder. Following right nephrectomy, the dog returned to training. One month later, elevations in urea nitrogen and creatinine were noted. Hematuria recurred at 3 months and the dog was found dead in its kennel. Necropsy showed a blood-filled left renal pelvis and ureter. PMID:1454185

1992-10-01

33

Solar-Geophysical Data Number 568, December 1991. Part 1 (prompt reports). Data for November, October 1991 and late data  

Energy Technology Data Exchange (ETDEWEB)

The contents include: Detailed index for 1991; Data for November 1991--Solar-terrestrial environment, IUWDS alert periods (advance and worldwide), Solar activity indices, Solar flares, Solar radio emission, Stanford mean solar magnetic field; Data for October 1991--Solar active regions, Sudden ionospheric disturbances, Solar radio spectral observations, Cosmic ray measurements by neutron monitor, Geomagnetic indices; Late data--Cosmic ray measurements by neutron monitor (Climax February and May 1990, Deep River May-August 1991), Geomagnetic indices (Sudden commencements/Solar flare effects January-May 1991); Errata--August 1991 Geomagnetic activity indices.

1991-12-01

34

Neural integrated control for a free-floating space robot with suddenly changing parameters  

British Library Electronic Table of Contents (United Kingdom)

Because the state of a free-floating space robot model is uncertain and sudden changes in the model parameters might undermine the stability of the system, this paper proposes a control strategy based on a variable structure neural integrated controller. This scheme does not need a precise space robot model, making use of the radial basis function neural network ability approach to learn about an uncertain model. The network weights are adjusted online in real-time. During the early period of the control phase and parameter changes, the variable structure controller compensates for the uncertain model which the neural network could not learn well. It also creates global asymptotic stability for the whole closed-loop system. Simulation results show that the controller can handle bad changea...

2011-01-01

35

Cardiac Channelopathies and Sudden Infant Death Syndrome  

British Library Electronic Table of Contents (United Kingdom)

Abstract Sudden infant death syndrome (SIDS) is always a devastating and unexpected occurrence. SIDS is the leading cause of death in the first 6 months after birth in the industrialized world. Since the discovery in 1998 of long QT syndrome as an underlying substrate for SIDS, around 10-20% of SIDS cases have been proposed as being caused by genetic variants in either ion channel or ion channel-associated proteins. Until now, 10 cardiac channelopathy susceptibility genes have been found to be implicated in the pathogenesis of SIDS. Four of the genes encode cardiac ion channel a-subunits, 3 genes encode ion channel b-subunits, and 3 genes encode other channel-interacting proteins. All 10 genes have been associated with primary electrical heart diseases. SIDS may hereby be the initial sympt...

2011-01-01

36

Analysis on anomalous degradation in silicon solar cell designed for space use  

Energy Technology Data Exchange (ETDEWEB)

Recently, we have found the anomalous degradation of electrical performance in silicon solar cells irradiated with charged particles in a high-fluence region. This anomalous phenomenon has two typical features, which are sudden-drop-down of electrical performances in a high-fluence region and slight recovery of the short circuit current I{sub SC} just before the sudden-drop-down. These features cannot be understood by a conventional model coming from the decrease of minority-carriers life-time. We introduce this anomalous degradation of the electrical performance in Si solar cells irradiated with electrons or protons. We also report the result of simulation for the fluence dependence of the I{sub SC}, and discuss the mechanism of this anomalous phenomenon. (author)

1997-03-01

37

Alumnium phosphide fatalities at mild exertion in asymptomatic children: A clue to understand the variations of the autopsy findings  

British Library Electronic Table of Contents (United Kingdom)

Fatalities resulted from aluminium phosphide (ALP) intoxication in completely healthy children with no preceded clinical sings or symptoms were presented. Data regarding circumstances, autopsy reports, histopathological examination, toxicological investigation, and police enquiries were also collected and evaluated. The affected children were females, and 6-16 years old. They were completely healthy and died suddenly in relation to some physical activities such as running, walking, and bathing, without any prior complain. The viscera showed intense congestion with moderate to severe pulmonary edema. The cause of the sudden termination of life in the reported cases is mostly cardiac ones. Physical exertion may precipitate death due to increased cardiac stress, increased oxygen demand, and b...

2009-01-01

38

Unsteady flow of an incompressible fluid in a horizontal porous medium with suction  

International Nuclear Information System (INIS)

A theoretical analysis of two-dimensional unsteady flow in a porous medium bounded by a horizontal wall is presented as a perturbation on a basic flow. It is assumed that the perturbation is occasioned by a sudden suction at the wall. Even for a highly permeable medium the characteristic Reynolds number in porous media flow is usually small and asymptotic solutions are developed by the Laplace transform technique. It is observed that the perturbed shear stress at the wall decays exponentially with time. (author). 5 refs.

2000-03-01

39

Method of controlling the coolant level in the cooling system of a nuclear power plant  

International Nuclear Information System (INIS)

Object: To prevent a sudden drop in the level of a coolant in a annular pipe encased within a downcomer pipe. Structure: The coolant levels in annular pipes encased within downcomer pipes are simultaneously measured by level gauges which generate signals representative of coolant levels. The signals are fed to a level control system which will actuate valves to regulate the cover gas pressure in order to average the level differences among the annular pipes in different downcomer pipes. (Kamimura, M.).

40

Kv1.1 potassium channel deficiency reveals brain-driven cardiac dysfunction as a candidate mechanism for sudden unexplained death in epilepsy(SUDEP)  

UK PubMed Central (United Kingdom)

Mice lacking Kv1.1 Shaker-like potassium channels encoded by the Kcna1 gene exhibit severe seizures and die prematurely. The channel is widely expressed in...Full Text Available

2010-04-14

 
 
 
 
41

Blood EPA and DHA Independently Predict All-Cause Mortality in Patients with Stable Coronary Heart Disease. The Heart and Soul Study  

UK PubMed Central (United Kingdom)

BackgroundOmega-3 fatty acid (n-3 FA) blood levels and intakes have been inversely associated with risk for sudden cardiac death, but their relationship with all-cause...Full Text Available

2010-07-01

42

[Pulmonary vascular manifestations in hereditary hemorrhagic telangiectasia].  

Science.gov (United States)

Hereditary hemorrhagic telangiectasia (Osler-Rendu-Weber disease) is a genetic disorder with autosomal dominance, variable penetrance, and an estimated prevalence of 1/10,000 inhabitants in France. Diagnosis is based on clinical criteria including epistaxis, telangiectasia, visceral manifestations, and familial occurrence. Pulmonary arteriovenous malformations, present in 15-33% of patients, are its primary visceral complications. The disease may be revealed by infectious and ischemic neurological manifestations due to paradoxical embolism. The high frequency of neurologic complications even in asymptomatic patients justifies systematic screening for pulmonary arteriovenous malformations. Treatment of these malformations is based on percutaneous transcatheter coil embolization of the feeding artery. Pulmonary arterial hypertension is rare in this disease. It may be due to systemic arteriovenous shunting in the liver, which increases cardiac output, or be similar to ...

2005-11-01

43

Treatment of asymptomatic internal resorption of a maxillary premolar tooth in a military working dog.  

Science.gov (United States)

An asymptomatic pink discoloration of a maxillary right fourth premolar tooth was discovered during a routine oral examination on a 9 year-old Belgian Malinois dog. A radiolucent lesion was seen in the pulpal chamber on radiographic examination. The lesion had perforated the mesiobuccal root of the tooth. The primary differential diagnosis was idiopathic internal resorption. The tooth was treated by partial resection (removal of the mesiobuccal root and associated crown). A vital pulpotomy and amalgam restoration was performed on the remaining tooth structure. A follow-up 1 year later demonstrated a successful treatment outcome. The animal was asymptomatic and able to perform military duties. Clinical and radiographic signs of healing were evident and the tooth was functional. PMID:10518874

1998-12-01

44

The use of peritoneal venous shunting for intractable neonatal ascites: a short case series  

British Library Electronic Table of Contents (United Kingdom)

Introduction: Intractable ascites in neonates has a varied etiology; and often, the cause is idiopathic. The management usually consists of observation, diuretics, paracentesis, albumin replacements, and self correction. However, in some cases, the above treatment remains unsuccessful. Results: We present 2 cases of intractable ascites causing metabolic abnormalities, severe protein and immunoglobulin loss, and respiratory compromise. Although the use of peritoneovenous shunts for intractable ascites has been reported previously, our cases differ in both technique and patient size. Our first patient is an ex-28-week premature, 1.4-kg infant with intractable ascites for which a peritoneal drain was initially placed. After 3 weeks and putting out nearly 300 mL of ascitic fluid daily, we plac...

2011-01-01

45

Mucosal Inflammation in Spondylarthritides: Past, Present, and Future  

British Library Electronic Table of Contents (United Kingdom)

Spondylarthritides (SpA) and inflammatory bowel disease (IBD) are idiopathic, chronic inflammatory disorders. Although they are very distinct and well-defined entities, there is clinical and genetic evidence supporting some degree of overlap between the pathogenesis of the two. Subclinical gut inflammation is present in up to two thirds of all SpA patients and can evolve into IBD. This subclinical gut inflammation has been shown to be strongly associated with joint inflammation, providing a clue for a common pathophysiologic background. Despite extensive research progress in the field over the past few years, many questions remain unanswered. In this paper, we focus on the clinical, genetic, and pathophysiologic overlap of SpA and IBD. Furthermore, we discuss some of the targets that may i...

2011-01-01

46

Manganese Induces IGF-1 and Cyclooxygenase-2 Gene Expressions in the Basal Hypothalamus during Prepubertal Female Development  

British Library Electronic Table of Contents (United Kingdom)

Precocious puberty is a significant child health problem, especially in girls, because 95% of cases are idiopathic. Our earlier studies demonstrated that low-dose levels of manganese (Mn) caused precocious puberty via stimulating the secretion of luteinizing hormone-releasing hormone (LHRH). Because glial-neuronal communications are important for the activation of LHRH secretion at puberty, we investigated the effects of prepubertal Mn exposure on specific glial-derived puberty-related genes known to affect neuronal LHRH release. Animals were supplemented with MnCl2 (10 mg/kg) or saline by gastric gavage from day 12 until day 22 or day 29, then decapitated, and brains removed. The site of LHRH release is the medial basal hypothalamus (MBH), and tissues from this area were analyzed by real-...

2011-01-01

47

Assessment of chromosomal abnormalities in sperm of infertile men using sperm karyotyping and multicolour fluorescence in situ hybridization (FISH)  

Energy Technology Data Exchange (ETDEWEB)

Individuals with male factor infertility resulting from idiopathic oligo-, astheno- or teratozoospermia are frequently offered IVF in an attempt to increase their chances of having a child. A concern remains whether these infertile males have an elevated risk of transmitting chromosomal abnormalities to their offspring. Sperm chromosomal complements from these men were assayed using the human sperm/hamster oocyte fusion system and fluorescence in situ hybridization (FISH) on sperm nuclei. For each of 5 infertile patients, 100 sperm karyotypes were analyzed and multicolour FISH analysis was performed on a minimum of 10,000 sperm nuclei for each chromosome-specific DNA probe for chromosomes 1 (pUC1.77), 12 (D12Z3), X (XC) and Y (DYZ3). As a group, the infertile patients showed increased frequencies of both numerical ({chi}{sup 2}=17.26, {proportional_to} <0.001) and total abnormalities ({chi}{sup 2}=7.78, {proportional_to} <0.01) relative to control donors when ...

1994-09-01

48

Explosions of chaotic sets  

Science.gov (United States)

Large-scale invariant sets such as chaotic attractors undergo bifurcations as a parameter is varied. These bifurcations include sudden changes in the size and/or type of the set. An explosion is a bifurcation in which new recurrent points suddenly appear at a non-zero distance from any pre-existing recurrent points. We discuss the following. In a generic one-parameter family of dissipative invertible maps of the plane there are only four known mechanisms through which an explosion can occur: (1) a saddle-node bifurcation isolated from other recurrent points, (2) a saddle-node bifurcation embedded in the set of recurrent points, (3) outer homoclinic tangencies, and (4) outer heteroclinic tangencies. (The term ``outer tangency'' refers to a particular configuration of the stable and unstable manifolds at tangency.) In particular, we examine different types of tangencies of stable and unstable manifolds from orbits of pre-existing invariant sets. ...

2000-09-01

49

Sudden freeze-out vs continuous emission: duality in hydro-kinetic approach to A+A collisions  

CERN Document Server

The problem of spectra formation in hydrodynamic approach to A+A collisions is discussed. It is analyzed in terms of the two different objects: distribution and emission functions. We show that though the process of particle liberation, described by the emission function, is, usually, continuous in time, the observable spectra can be also expressed by means of the Landau/Cooper-Frye prescription. We argue that such an approximate duality results from some symmetry properties that systems in A+A collisions reach to the end of hydrodynamic evolution and reduction of the collision rate at post hydrodynamic stage

2004-01-01

50

Some reflections on the network power plant interaction  

International Nuclear Information System (INIS)

The layout of the network with its frequency and transmission power control shows how the time behaviour of power plants and consumers determines the frequency curve during sudden power disturbances. As for switching processes in the network for the turbine, network operation entails loads due to shock-like disturbance functions to which one should not normally respond by switching off. The interception controllers are therefore adjusted via a simulation model by which the vibrations of the turbine rotor can be modelled in real time under different network loads. (GL).

1978-11-24

51

Phase transitions for modified Erd\\"os-R\\'enyi processes  

CERN Document Server

A fundamental and very well studied region of the Erd\\"os-R\\'enyi process is the phase transition at n/2 edges in which a giant component suddenly appears. We examine the process beginning with an initial graph. We further examine the Bohman-Frieze process in which edges between isolated vertices are more likely. While the positions of the phase transitions vary, the three processes belong, roughly speaking, to the same universality class. In particular, the growth of the giant component in the barely supercritical region is linear in all cases.

2010-01-01

52

Particle emission in hydrodynamics: a problem needing a solution  

CERN Document Server

A survey of various mechanisms for particle emission in hydrodynamics is presented. First, in the case of sudden freeze out, the problem of negative contributions in the Cooper-Frye formula and ways out are presented. Then the separate chemical and thermal freeze out scenario is described and the necessity of its inclusion in a hydrodynamical code is discussed. Finally, we show how to formulate continuous particle emission in hydrodynamics and discuss extensively its consistency with data. We point out in various cases that the interpretation of data is quite influenced by the choice of the particle emission mechanism.

2004-01-01

53

CC, CS, and IOS generalized phenomenological cross sections for atom--diatom mixtures  

Energy Technology Data Exchange (ETDEWEB)

Close coupled expressions for phenomenological cross sections which describe transport properties of atom--diatom mixtures are obtained in the total-J coupling scheme and are related to the bracket integrals of kinetic theory. Coupled states and infinite order sudden expressions for the generalized phenomenological cross sections using initial, final, and average l-labeling are also given. Particular care is taken to use a phase convention for the CS and IOS approximations which is consistent with the Arthurs--Dalgarno formalism and which gives the correct behavior of degeneracy averaged differential cross sections.

1981-05-01

54

All Optical Switch of Vacuum Rabi Oscillations: The Ultrafast Quantum Eraser  

CERN Document Server

We study the all-optical time-control of the strong coupling between a single cascade three-level quantum emitter and a microcavity. We find that only specific arrival-times of the control pulses succeed in switching-off the Rabi oscillations. Depending on the arrival times of control pulses, a variety of exotic non-adiabatic cavity quantum electrodynamics effects can be observed. We show that only control pulses with specific arrival times are able to suddenly switch-off and -on first-order coherence of cavity photons, without affecting their strong coupling population dynamics. Such behavior may be understood as a manifestation of quantum complementarity.

2010-01-01

55

One-year follow-up of the effects of sildenafil on pulmonary arterial hypertension and veno-occlusive disease  

Scientific Electronic Library Online (English)

Abstract in english We hypothesized that chronic oral administration of the phosphodiesterase-5 inhibitor sildenafil could improve the exercise capacity and pulmonary hemodynamics in patients with pulmonary arterial hypertension (PAH) on the basis of previous short-term studies. We tested this hypothesis in 14 subjects with PAH, including seven patients with the idiopathic form and seven patients with atrial septal defects, but no other congenital heart abnormalities. Patients were subjected (more) to a 6-min walk test and dyspnea was graded according to the Borg scale. Pulmonary flow and pressures were measured by Doppler echocardiography. Patients were given sildenafil, 75 mg orally three times a day, and followed up for 1 year. Sildenafil therapy resulted in the following changes: increase in the 6-min walk distance from a median value of 387 m (range 0 to 484 m) to 462 m (range 408 to 588 m; P

2005-02-01

56

Citrat og nyresten  

DEFF Research Database (Denmark)

Citrate is an important naturally occurring inhibitor of calcium stone formation in urine. Urinary citrate excretion was examined in 43 consecutive patients with recurrent idiopathic calcium nephrolithiasis and in 50 normal controls by a specific enzymatic technique. Hypocitraturia (<1.6 mmol/24h) was found in 14 (33%) stone formers compared to 6 (12%) normal controls (p = 0.03). Citrate excretion expressed as citrate-creatinine ratio in 24 hour urine samples was significantly lower in the stone formers than in the healthy controls (p = 0.03), and significantly lower in healthy men, compared to healthy females (p = 0.006). There was a great variability in urinary citrate levels in both groups, and a considerable overlap in the urinary citrate excretion between normal subjects and stone formers. Factors other than urinary citrate excretion must therefore be of importance in the pathophysiology of calcium stone formation. Citrate-calcium ratio in urine proved to ...

1993-01-01

57

Time-odd distribution functions, breaking of long range correlations, and sudden entropy changes, in Drell-Yan high-energy processes  

International Nuclear Information System (INIS)

Time-odd parton distribution functions in a Drell-Yan process are here studied by examining the evolution of the internal statistical properties of the interacting hadrons. Time-odd functions are shown to be a signature of the irreversible process in which a hadronic state characterized by long range correlation properties (hadronic phase) decays to produce a cloud of independent partons (partonic phase) because of initial/final state interactions. The relevant considered variable is the rate of increase of the entropy of the hadronic system. This quantity is shown to be roughly equal to the decay rate of the hadronic state. Conditions for getting a leading twist time-odd effect are established on this basis. Last, the relevant case of a large entropy increase associated with transverse-dominated initial/final state interactions is analyzed.

2007-04-01

58

Temperature dependence of density and compressibility of eutectic mixtures of alkali metal chlorides near melting point  

International Nuclear Information System (INIS)

Hydrostatic weighing was used to measure the pre-melt density of crystalline eutectic mixtures of alkaline metal chlorides of the compositions (mole fractions): 0.605 LiCl + 0.395 CsCl, 0.585 LiCl + 0.415 KCl, 0.297 NaCl + 0.246 KCl + 0.457 CsCl, and 0.348 NaCl + 0.652 CsCl with melting points 598, 628, 753, 763 K, respectively, as a function of temperature. In the same temperature ranges, the compressibility and molar volume of eutectics as well as their sudden change upon melting were estimated. Unusual variations of these properties were revealed near the crystal/liquid phase transition, which were related to local disordering of particle configuration

59

Solar-Geophysical Data Number 438, February 1981. Part 1 (prompt reports). Data for January 1981, December 1980 and late data  

Energy Technology Data Exchange (ETDEWEB)

Contents include: index for 1970-1980; January 1981 data -- alert periods, daily solar indices, solar flares, solar radio emission, coronal holes, inferred interplanetary magnetic field polarities, mean solar magnetic field, spacecraft observations, December 1980 data -- daily solar-activity centers, sudden ionospheric disturbances, spacecraft observations, solar radio emission, cosmic rays, geomagnetic indices, radio-propagation indices; late data -- solar radio emission November, December 1980, spacecraft observations November 1980, cosmic rays, Huancayo Oct 1980 -- climax, alert, Deep River Nov 1980.

1981-02-01

60

Short-term under/overreaction, anticipation or uncertainty avoidance? Evidence from India  

British Library Electronic Table of Contents (United Kingdom)

We examine the short-term price behaviour of three, size-conditioned Indian stock market indices, in response to informational shocks. A standard mean-adjusted returns model as well as the GJR-GARCH specification point towards underreaction to negative events in the medium and small capitalization indices. Also, the pre-event coefficients are generally negative and statistically significant, regardless of the sign of the shock, thus ruling out information leaks. We uncover a stable abnormal volatility pattern which increases monotonically a few days before the shock before suddenly decreasing in magnitude on the event day and beyond. We suggest uncertainty avoidance as a potential explanation of these features. The results are fairly robust across alternative event selection procedures, ti...

2011-01-01

 
 
 
 
61

Modelling of density limit phenomena in toroidal helical plasmas  

Energy Technology Data Exchange (ETDEWEB)

The physics of density limit phenomena in toroidal helical plasmas based on an analytic point model of toroidal plasmas is discussed. The combined mechanism of the transport and radiation loss of energy is analyzed, and the achievable density is derived. A scaling law of the density limit is discussed. The dependence of the critical density on the heating power, magnetic field, plasma size and safety factor in the case of L-mode energy confinement is explained. The dynamic evolution of the plasma energy and radiation loss is discussed. Assuming a simple model of density evolution, of a sudden loss of density if the temperature becomes lower than critical value, then a limit cycle oscillation is shown to occur. A condition that divides the limit cycle oscillation and the complete radiation collapse is discussed. This model seems to explain the density limit oscillation that has been observed on the W7-AS stellarator. (author)

2000-03-01

62

Mesenchymal stem cell transplantation for diffuse alveolar hemorrhage in SLE  

British Library Electronic Table of Contents (United Kingdom)

Background. A 19-year-old girl was diagnosed with systemic lupus erythematosus, based on findings of arthritis, malar rash, positive antinuclear antibody test and high levels of antibodies to double-stranded DNA. Two months after diagnosis, the patient presented with a sudden drop in blood hemoglobin level. Several days later, she developed bloody sputum, rapidly progressive dyspnea and hypoxemia. High-resolution CT showed diffuse alveolar infiltrates in both lung fields.Investigations. Physical examination, complete blood count, erythrocyte sedimentation rate, urinalysis, 24-h urine protein excretion, fecal occult blood test, d-dimer test, acid hemolysis test, activated partial thromboplastin time and prothrombin time, direct and indirect Coombs tests, bone marrow smear, arterial blood ga...

2010-01-01

63

Local heat transfer augmentation in channels with two opposite ribbed surfaces  

Science.gov (United States)

The local heat transfer coefficient distribution of a square channel with two opposite ribbed walls was determined. The square channel was connected to a sudden contraction entrance in order to simulate the inlet condition of the turbine blade cooling passages. The test channel was heated by thin stainless steel foils with a thickness of 0.000025 m, and instrumented with 180 thermocouples. The brass ribs of a square cross-section were glued periodically, in line, onto the top and bottom walls of the foil-heated channel in patterns to achieve the desired spacing and angle-of-attack. The local heat transfer coefficients on the smooth side and the ribbed side walls, at the channel entrance and the downstream regions, were measured for eight rib configurations and three Reynolds numbers (Re = 10,000, 30,000, and 60,000).

1986-01-01

64

Liquid level control system of fast reactor secondary cooling system  

International Nuclear Information System (INIS)

Object: To minimize the range of the liquid level variation of the cooling system and reduce the time required for the liquid level control by sealing the gas of a cover gas respiration system which acts upon an evaporator and pump overflow column. Structure: In liquid level control by the cover gas pressure of a high-speed reactor secondary cooling system, upon occurrence of a sudden change in the rate of flow of the recirculated liquid, automatic check valves provided in an evaporator and pump overflow column cover gas respiration system are completely or substantially closed, while at the same time the recirculation cooling medium is sucked up and an automatic check valve provided in the overflow system is closed. (Kamimura, M.).

65

Irreversible Performance of a Quantum Harmonic Heat Engine  

CERN Document Server

The unavoidable irreversible losses of power in a heat engine are found to be of quantum origin. Following thermodynamic tradition a model quantum heat engine operating by the Otto cycle is analyzed. The working medium of the model is composed of an ensemble of harmonic oscillators. A link is established between the quantum observables and thermodynamical variables based on the concept of canonical invariance. These quantum variables are sufficient to determine the state of the system and with it all thermodynamical variables. Conditions for optimal work, power and entropy production show that maximum power is a compromise between the quasistatic limit of adiabatic following on the compression and expansion branches and a sudden limit of very short time allocation to these branches. At high temperatures and quasistatic operating conditions the efficiency at maximum power coincides with the endoreversible result. The optimal compression ratio varies from the square ...

2006-01-01

66

Experimental demonstration of three-color entanglement  

CERN Document Server

Entanglement is the essential quantum resource for a potential speed-up of information processing, as well as for sophisticated quantum communication. Quantum information networks will be required to convey information from one place to another, by using entangled light beams. Many physical systems are under consideration as building blocks, with different merits and faults, so that hybrid systems are likely to be developed. Here we present an important tool for connecting systems that share no common resonance frequencies: we demonstrate the first direct generation of entanglement among more than two bright beams of light, all of different wavelengths (532.251 nm, 1062.102 nm, and 1066.915 nm). We also observe, for the first time, disentanglement for finite channel losses, the continuous variable counterpart to entanglement sudden death.

2010-01-01

67

Cardiac Pacing: Memories of a Bygone Era  

British Library Electronic Table of Contents (United Kingdom)

The first cardiac pacemaker implants occurred in the late 1950s and involved insertion of epicardial or epimyocardial leads and abdominal pulse generators. By the mid 1960s, cardiologists were making attempts to insert transvenous leads into the right ventricle. These early unipolar leads had large, polished, high polarization electrodes, no fixation device, and no lumen in which to place a stylet for lead positioning. The lead implantation procedures were usually long and the irradiation to both patient and operator excessive. Pulse generators were powered by zinc-mercury cells, which were large, unreliable, and prone to sudden output failure. Postoperative complications such as lead dislodgement, exit block, and premature power source failure were very common with most patients requiring...

2008-01-01

68

Blowdown thrust force under pipe rupture accident. Pt. 1. Experimental evaluations of blowdown thrust force and decompression characteristics  

Energy Technology Data Exchange (ETDEWEB)

Blowdown thrust forces and decompression characteristics were evaluated concerning the jet discharge or pipe whip tests with a 4-inch or 6-inch diameter pipe under PWR LOCA or BWR LOCA conditions related to pipe rupture accidents in nuclear power plants. This paper presents experimental evaluations of time-dependent and maximum blowdown thrust forces, and evaluations of decompression characteristics under instantaneous pipe rupture conditions. The following items are discussed: the peak value of the blowdown thrust force, the jet thrust coefficient for the maximum blowdown thrust force, the pressure recovery after break, and the relationship between the pressure undershoot of the sudden decompression and the decompression rate.

1984-06-01

69

Behaviour of steam turbine power control of large power plant units in case of network short-circuits  

International Nuclear Information System (INIS)

In order to investigate the behaviour of the turbine control system during strong pendulum motions, an analysis is carried out using a digital computer program by which the reactor, the turbine, the generator and, in a simplified way, the network can be simulated to the necessary degree. Plotter pictures can show the main physical quantities. In all cases, the turbine control system should be able to distinguish between strong pendulum amplitude with acceleration of the rotational angles and sudden release criteria. This demand can be satisfied by a simple adjustment in the Kraftwerk Union turbine control system. Only a few seconds after shut-off of a severe network failure, the turbines are back to their rated power, thus contributing to reliability of supply in this critical network situation. (orig.).

1978-11-24

70

A real-time routing model for hazardous materials  

Energy Technology Data Exchange (ETDEWEB)

Experiences in hazardous materials transportation show that purely strategic or planning approaches have considerable shortcomings and that real-time management must be addressed. The commercialization of advanced location and communications technology provides the basis for real-time guidance. Considering the possibilities this new technology offers, a real-time routing model is proposed. It is based on the premises that a human dispatcher must assess the impacts of sudden events on safety and transportation costs and evaluate safe and cost-effective routing alternatives. Due to high uncertainty and time constraints in this real-time environment, risks and transportation costs are expressed as preferences on an ordinal scale. The model has been integrated into a decision support system and assessed in an experimental setting. This ordinal preference model turned out to be superior to a utility approach due to its robustness in risk assessment and route selection

1994-06-30

71

Sudden infant death syndrome and placental disorders: the thyroid-selenium link.  

Science.gov (United States)

Placental insufficiency, inducing hypoxia-ischaemia, is considered a major cause of neuronal injury and impaired post natal development. Placental insufficiency alters the metabolism of arachidonic acid and its oxidation products. Premature labour and low-birth-weight infants are associated with reduced intrauterine blood-flow and infections of the reproductive tract. Thyroidal activity is depressed in undernutrition (placental insufficiency). Premature infants require extra vitamin C for normal tyrosine metabolism (tyrosine is the thyroxine precursor). Among the symptoms indicating infantile cretinism, which appear during 3-5 months of age are: delayed union of skull bones, torpid behaviour, slow feeding, cyanosis during feeding, excessive sleepiness, enlarged tongue, umbilical herniation, flabby musculature, short stature and delayed development. These symptoms have all been described in low-birth-weight infants and sudden infant death syndrome victims by various ...

1997-04-01

72

Pituitary disease in childhood: utility of magnetic resonance; Patologia hipofisaria en la edad pediatrica: unidad de la resonance magnetica  

Energy Technology Data Exchange (ETDEWEB)

To assess the utility of magnetic resonance (MR) imaging in the study of pediatric patients with clinical suspicion of pituitary disease. We studied 18 patients aged 7 to 18 years.Fifteen had hormonal disturbances, two presented amenorrhea and 1 complained of headache, fever and symptoms of polyuria and polydipsia. All the patients were examined using a Siemens SP 42 1-Tesla MRI scanner. Sagittal and coronal T1-weighted spin-echo images were obtained; in addition T2-weighted spin-echo or fast spin-echo imaging was performed in ten cases and intravenous gadolinium was administered in nine. We found 9 patients with hypothalamic-pituitary dysgenesis, 2 with germinoma, 2 cases of pituitary hemosiderosis in patients with thalassemia, 2 cases of microadenoma, one abscess, one case of idiopathic central diabetes insipidus and one of Langerhans cell histiocytosis. MR enabled us to assess pituitary structural alterations in children with hypothalamic-pituitary hormone ...

2000-07-01

73

Disorders of brain development and phakomatosis  

International Nuclear Information System (INIS)

Full text: Disorders of brain development and phakomatosis are resulting from disturbed embryonic-foetal development One third of all major embryological anomalies involve CNS, and over 2000 different anomalies have been described. Anomalies of the brain often cause foetal and neonatal death, and mental and physical retardation in pediatric group. The majority of disorders of brain development and phakomatosis are idiopathic, and most of them are not hereditary or familial. Ultrasonography plays the important role in screening foetal and neonatal brain, but after closure of fontanels it is difficult to find the acoustic window. CT has limited contrast resolution, and disadvantage exposing infant to ionizing radiation. It is helpful to demonstrate the presence of calcifications. MR imaging has proved to be a diagnostic tool of major importance in children with disorders of brain development and phakomatosis. The excellent grey/white matter differentiation and ...

74

Assessment of bone formation and bone resorption in osteoporosis: a comparison between tetracycline-based iliac histomorphometry and whole body /sup 85/Sr kinetics  

Energy Technology Data Exchange (ETDEWEB)

Bone formation and resorption have been measured in patients with idiopathic osteoporosis by histomorphometry of 7.5-mm trephine biopsies and in the whole body by 85Sr radiotracer methodology and calcium balances. The studies were synchronized and most were preceded by double in vivo tetracycline labeling. Correlations between histological and kinetic bone formation indices were better when better when based on the extent of double tetracycline labels than on measurements of osteoid by visible light microscopy. Correction of the kinetic data for long-term exchange, using 5 months' serial whole body counting of retained 85Sr, improved the fit of the kinetic to the histological data. A statistical analysis of the measurement uncertainties showed that the residual scatter in the best correlations (between exchange-corrected bone formation rates and double-labeled osteoid surface indices) could be attributed to measurement imprecision alone. The ...

1987-12-01

75

Utility activities that create power quality problems  

Energy Technology Data Exchange (ETDEWEB)

Power quality problems are caused by activities normal to utility operations such as maintenance outages and capacitor switching or events that are abnormal such as lightning strikes and equipment failures. Disconnection and reconnection of transmission lines and transformers can cause switching surges, and are more severe on extra high voltage transmission lines than high voltage lines. Capacitor switching can cause transients and harmonics that may affect sensitive equipment, and are the source of 3rd, 5th, 7th and 9th harmonics in the hundreds of hertz ranges. Overload, sudden loss of generating capacity and transmission line faults are typical problems affecting system stability. Fault interruptions and reclosings can cause surges in the distribution system, and lightning strikes may cause voltage surges or dips due to arrester sparkover. Blackouts, brownouts, voltage fluctuations, travelling wave overvoltages, capacitor restrikes, harmonics and harmonic ...

1992-02-01

76

Uncovering camouflage: amygdala activation predicts long-term memory of induced perceptual insight.  

Science.gov (United States)

What brain mechanisms underlie learning of new knowledge from single events? We studied encoding in long-term memory of a unique type of one-shot experience, induced perceptual insight. While undergoing an fMRI brain scan, participants viewed degraded images of real-world pictures where the underlying objects were hard to recognize ("camouflage"), followed by brief exposures to the original images ("solution"), which led to induced insight ("Aha!"). A week later, the participants' memory was tested; a solution image was classified as "remembered" if detailed perceptual knowledge was elicited from the camouflage image alone. During encoding, subsequently remembered images were associated with higher activity in midlevel visual cortex and medial frontal cortex, but most pronouncedly, in the amygdala, whose activity could be used to predict which solutions will remain in long-term memory. Our findings extend the known roles of amygdala in memory to include promotion of long-term memory of ...

2011-03-10

77

Theoretical study of asymmetric molecular-frame photoelectron angular distributions for C 1s photoejection from CO2  

Energy Technology Data Exchange (ETDEWEB)

We report the results of ab initio calculations of cross sections and molecular-frame photoelectron angular distributions for C 1s ionization of CO2, and propose a mechanism for the recently observed asymmetry of those angular distributions with respect to the CO^+and O^+ions produced by subsequent Auger decay. The fixed-nuclei, photoionization amplitudes were constructed using variationally obtained electron-molecular ion scattering wave functions. We have also carried out electronic structure calculations which identify a dissociative state of the CO2^++ dication that is likely populated following Auger decay and which leads to O^+ + CO^+ fragment ions. We show that a proper accounting of vibrational motion in the computation of the photoelectron angular distributions, along with reasonable assumptions about the nuclear dissociation dynamics, gives results in good agreement with recent experimental observations. We also demonstrate that destructive interference between different ...

2009-02-18

78

Spiral Structures and Shocks in Accretion Discs in Close Binary Systems: the Role of the Stellar Mass Ratio.  

Science.gov (United States)

% In this work we investigated, in the Smooth Particle Hydrodynamics (SPH) framework, the development of spiral structures and shock fronts in the radial flow of accretion discs in close binary systems. These shock waves take place when the initially supersonic radial flow penetrating the disc bulk, reduces substantially its speed becoming suddenly subsonic. To this purpose, keeping constant the mass of the compact primary (M1 = 1 MO ), the separation between the two components and the injection speed at the inner Lagrangian point L1 (close to the local sound speed), we carried out 2D SPH simulations for four values of the stellar mass ratio M2/M1. We worked out 2D models because the damping effect of the artificial viscosity is too strong in 3D. Furthermore, the 2D environment seems the most suitable in order to evidence shock fronts in highly compressible gases. The results show that spiral structures and shock fronts develop for low values of M2/M1, whilst they ...

2000-06-01

79

Relationships between bone structure in the iliac crest and bone structure and strength in the lumbar spine.  

Science.gov (United States)

The purpose of this study was to examine the relationship between histomorphometric variables of cancellous bone structure and ultimate compressive strength (UCS) in the second lumbar vertebra (L2) and to determine whether structural variables in the iliac crest are predictive of the same variables and of UCS in L2. At autopsy, 7.5 mm diameter cores were removed from the iliac crest and from L2 of 29 subjects who had died suddenly without bone disease. Cancellous bone volume (BV/TV, %) was significantly lower in L2 than in iliac crest due to lower trabecular number (Tb.N, per mm) and thickness (Tb.Th, microns). There were significant correlations between iliac crest and L2 for BV/TV, Tb.N and trabecular separation (Tb.Sp, microns), but not for Tb.Th. BV/TV was negatively correlated, and Tb.Sp was positively correlated with age at both sites. Tb.Th was not significantly correlated with age in the iliac crest, but a significant negative correlation was observed in ...

1993-03-01

80

Ramp-rate sensitivity of SSC dipole magnet prototypes  

Energy Technology Data Exchange (ETDEWEB)

One of the major achievements of the magnet R&D program for the Superconducting Super Collider (SSC) is the fabrication and test of a series of 20 5-cm aperture, 15-m long dipole magnet prototypes. The ramp rate sensitivity of these magnets appears to fall in at least two categories that can be correlated to the manufacturer and production batch of the strands used for the inner-coil cables. The first category, referred to as type-A, is characterized by a strong quench current degradation at high ramp rates, usually accompanied by large distortions of the multipole fields and large energy losses. The second category, referred to as type-B, is characterized by a sudden drop of quench current at low ramp rates, followed by a much milder degradation at larger rates. The multipole fields of the type-B magnets show little ramp-rate sensitivity, and the energy losses are smaller than for the type-A magnets. The behavior of the Type-A magnets can be explained in terms ...

1994-07-01

 
 
 
 
81

Preparation of Size-tunable, Highly Monodisperse PVP-Protected Pt-nanoparticles by Seed-mediated Growth  

Energy Technology Data Exchange (ETDEWEB)

We demonstrate a preparative method which produces highly-monodisperse Pt-nanoparticles of tunable size without the external addition of seed particles. Hexachloroplatinic acid is dosed slowly to an ethylene glycol solution at 120 C and reduced in the presence of a stabilizing polymer poly-N-vinylpyrollidone (PVP). Slow addition of the Pt-salt first will first lead to the formation of nuclei (seeds) which then grow further to produce larger particles of any desired size between 3 and 8nm. The amount of added hexachloroplatinic acid precursor controls the size of the final nanoparticle product. TEM was used to determine size and morphology and to confirm the crystalline nature of the nanoparticles. Good reproducibility of the technique was demonstrated. Above 7nm, the particle shape and morphology changes suddenly indicating a change in the deposition selectivity of the Pt-precursor from (100) towards (111) crystal faces and breaking up of larger particles into ...

2008-04-02

82

Plastic instability in an omega forming Ti-l5% Mo alloy  

International Nuclear Information System (INIS)

The plastic flow behavior of a #beta#-titanium alloy (Ti-15% Mo) was investigated over a wide range of temperatures and strain rates covering those conditions where the #omega#-phase forms dynamically. Portevin-Le Chatelier (PLC) effect was observed in this alloy at temperatures between 575 and 775 K at a strain rate of 1.31 x 10"-"4 s"-"1. The serrated flow behavior of this alloy could be suppressed by rendering the matrix #beta#-phase more stable against the #beta# to #omega# transformation. PLC bands formed in this alloy, studied at different levels of magnification using light, scanning electron and transmission electron microscopy, showed a high density of deformation bands within the macroscopic PLC band. The following mechanism of serrated flow is proposed; the load drop is ascribed to the sudden flow associated with the formation of deformation bands within which #omega#-particles were destroyed while the subsequent load rise results from pinning of ...

83

Paleo-botanical evidence for ecosystem disruption at the Cretaceous-Tertiary boundary from Wood Mountain, Saskatchewan, Canada  

Energy Technology Data Exchange (ETDEWEB)

A continuous, subsurface Cretaceous-Tertiary boundary section, including the boundary clay within an 87 cm thick lignite, has been recovered from a core hole near Wood Mountain, Saskatchewan, Canada. The lignite-encompassed clay layer with geochemical anomaly indicates that peat deposition was continuous across the boundary. Core data indicate that, locally, a pre-boundary, conifer-dominated swamp was abruptly replaced by an angiosperm-dominated, herbaceous wetland. Sudden extermination of the dominant forest elements indicates mass kill at the level of the boundary and supports the theory of extraterrestrial impact accompanied by catastrophic destruction. Devastation of the standing vegetation may have been caused by one or more of the killing agents predicted to have accompanied impact, including freezing temperatures caused by atmospheric dust, acid rain, thermal pulse, and shock waves. There is no evidence supporting wildfires as a killing agent. Vegetational ...

1999-05-01

84

MODFLOW 2.0: A program for predicting moderator flow patterns  

Energy Technology Data Exchange (ETDEWEB)

Sudden changes in the temperature of flowing liquids can result in transient buoyancy forces which strongly impact the flow hydrodynamics via flow stratification. These effects have been studied for the case of potential flow of stratified liquids to line sinks, but not for moderator flow in SRS reactors. Standard codes, such as TRAC and COMMIX, do not have the capability to capture the stratification effect, due to strong numerical diffusion which smears away the hot/cold fluid interface. A related problem with standard codes is the inability to track plumes injected into the liquid flow, again due to numerical diffusion. The combined effects of buoyant stratification and plume dispersion have been identified as being important in operation the Supplementary Safety System which injects neutron-poison ink into SRS reactors to provide safe shutdown in the event of safety rod failure. The MODFLOW code discussed here provides transient moderator flow pattern ...

1991-07-01

85

MODFLOW 2. 0: A program for predicting moderator flow patterns  

Energy Technology Data Exchange (ETDEWEB)

Sudden changes in the temperature of flowing liquids can result in transient buoyancy forces which strongly impact the flow hydrodynamics via flow stratification. These effects have been studied for the case of potential flow of stratified liquids to line sinks, but not for moderator flow in SRS reactors. Standard codes, such as TRAC and COMMIX, do not have the capability to capture the stratification effect, due to strong numerical diffusion which smears away the hot/cold fluid interface. A related problem with standard codes is the inability to track plumes injected into the liquid flow, again due to numerical diffusion. The combined effects of buoyant stratification and plume dispersion have been identified as being important in operation the Supplementary Safety System which injects neutron-poison ink into SRS reactors to provide safe shutdown in the event of safety rod failure. The MODFLOW code discussed here provides transient moderator flow pattern ...

1991-07-01

86

Ly-alpha emitters: blue dwarfs or supermassive ULIRGs? Evidence for a transition with redshift  

CERN Document Server

The traditional view that Ly-alpha emission and dust should be mutually exclusive has been questioned more and more often, notably the observations of Ly-alpha emission from ULIRGs seems to counter this view. In this paper we seek to address the reverse question: How large a fraction of Ly-alpha selected galaxies are ULIRGs? Using two samples of 24/25 Ly-alpha emitting galaxies at z = 0.3/2.3 we perform this test, also including results at z = 3.1, and find that whereas the ULIRG fraction at z = 3.1 is very small, it systematically increases towards lower redshifts. There is a hint that this evolution may be quite sudden and that it happens around a redshift of z ~ 2.5. Measuring the infrared luminosities of the Ly-alpha emitters, we find that they are in the normal to ULIRG range in the lower redshift sample, whereas the higher redshift galaxies all have luminosities in the ULIRG category. The Ly-alpha escape fractions for these infrared bright galaxies are in the ...

2009-01-01

87

Large intracranial vessel occlusion arising after radiotherapy for craniopharingioma. A case report and review of the literature  

Energy Technology Data Exchange (ETDEWEB)

We report a patient who developed occlusion of the intracranial major arteries induced by radiation therapy for craniopharyngioma. The patient, a 9-year-old boy, presented with deterioration of vision, nausea and vomiting. He underwent a right ventriculo-peritoneal shunt operation, and the tumor was partially removed. Postoperatively, he received focal radiation therapy with total of 60 Gy. Preoperative cerebral angiography, cerebral vessels had no sigh of occlusive lesion or stenosis. One year after irradiation, he started to have repeated cerebral ischemic attacks. But no regrowth of the tumor was detected on CT scans. Two years and 8 months after irradiation, he suddenly had right hemiparesis. Cerebral angiography revealed severe stenosis of the right anterior cerebral artery (precommunicating segment), middle cerebral artery (horizontal portion) and terminal portion of the right carotid artery. Left carotid angiography showed complete occlusion of the terminal ...

1994-10-01

88

Large intracranial vessel occlusion arising after radiotherapy for craniopharingioma. A case report and review of the literature  

International Nuclear Information System (INIS)

We report a patient who developed occlusion of the intracranial major arteries induced by radiation therapy for craniopharyngioma. The patient, a 9-year-old boy, presented with deterioration of vision, nausea and vomiting. He underwent a right ventriculo-peritoneal shunt operation, and the tumor was partially removed. Postoperatively, he received focal radiation therapy with total of 60 Gy. Preoperative cerebral angiography, cerebral vessels had no sigh of occlusive lesion or stenosis. One year after irradiation, he started to have repeated cerebral ischemic attacks. But no regrowth of the tumor was detected on CT scans. Two years and 8 months after irradiation, he suddenly had right hemiparesis. Cerebral angiography revealed severe stenosis of the right anterior cerebral artery (precommunicating segment), middle cerebral artery (horizontal portion) and terminal portion of the right carotid artery. Left carotid angiography showed complete occlusion of the terminal ...

1994-01-01

89

Evaluation on the cooling capacity of the SMART-P CEDM cooler using CFD code  

Energy Technology Data Exchange (ETDEWEB)

Ball screw bearings are used for the fine control of Control Rod Drive Mechanism (CEDM) for the SMART-P. Because the friction coefficient of the ball screw bearings suddenly increases at the limit temperature of 120 .deg. C, the surrounding temperature of the ball screw bearings should be less than the limit temperature for the functional integrity of the CEDM. The CEDM coolers are installed at the lower portion of the ball screw bearings to maintain the bearings' temperature less than the limit. In order to check the CEDM cooler satisfy the temperature limit of ball screw bearing at the possible operational conditions, the cooling capacity of the CEDM coolers, which was determined at the stage of 'conceptual design', is evaluated using the Computational Fluid Dynamics(CFD) code, Fluent. The analysis result shows that the current CEDM coolers satisfy the CEDM temperature limit of 120 .deg. C for the all the operation modes of the SMART-P ...

2004-07-01

90

Evaluation on the cooling capacity of the SMART-P CEDM cooler using CFD code  

International Nuclear Information System (INIS)

Ball screw bearings are used for the fine control of Control Rod Drive Mechanism (CEDM) for the SMART-P. Because the friction coefficient of the ball screw bearings suddenly increases at the limit temperature of 120 .deg. C, the surrounding temperature of the ball screw bearings should be less than the limit temperature for the functional integrity of the CEDM. The CEDM coolers are installed at the lower portion of the ball screw bearings to maintain the bearings' temperature less than the limit. In order to check the CEDM cooler satisfy the temperature limit of ball screw bearing at the possible operational conditions, the cooling capacity of the CEDM coolers, which was determined at the stage of 'conceptual design', is evaluated using the Computational Fluid Dynamics(CFD) code, Fluent. The analysis result shows that the current CEDM coolers satisfy the CEDM temperature limit of 120 .deg. C for the all the operation modes of the SMART-P and there is a sufficient ...

2004-05-27

91

EVOLUTION OF MASSIVE STARS WITH PULSATION-DRIVEN SUPERWINDS DURING THE RED SUPERGIANT PHASE  

International Nuclear Information System (INIS)

Pulsations driven by partial ionization of hydrogen in the envelope are often considered important for driving winds from red supergiants (RSGs). In particular, it has been suggested by some authors that the pulsation growth rate in an RSG can be high enough to trigger an unusually strong wind (or a superwind), when the luminosity-to-mass ratio becomes sufficiently large. Using both hydrostatic and hydrodynamic stellar evolution models with initial masses ranging from 15 to 40 M_s_u_n, we investigate (1) how the pulsation growth rate depends on the global parameters of supergiant stars and (2) what would be the consequences of a pulsation-driven superwind, if it occurred, for the late stages of massive star evolution. We suggest that such a superwind history would be marked by a runaway increase, followed by a sudden decrease, of the wind's mass-loss rate. The impact on the late evolution of massive stars would be substantial, with stars losing a huge fraction of ...

2010-07-01

92

Delta Scorpii 2011 periastron: worldwide observational campaign and preliminary photometric analysis  

CERN Document Server

Delta Scorpii is a double giant Be star in the forefront of the Scorpio, well visible to the naked eye, being normally of magnitude 2.3. In the year 2000 its luminosity rose up suddenly to the magnitude 1.6, changing the usual aspect of the constellation of Scorpio. This phenomenon has been associated to the close periastron of the companion, orbiting on a elongate ellipse with a period of about 11 years. The periastron, on basis of high precision astrometry, is expected to occur in the first decade of July 2011, and the second star of the system is approaching the atmosphere of the primary, whose circumstellar disk has a H-alpha diameter of 5 milliarcsec, comparable with the periastron distance. The preliminary results of a photometric campaign, here presented in the very days of the periastron, show an irregular behavior of the star's luminosity, which can reflect some shocks between material around the two stars. The small luminosity increasement detected in the ...

2011-01-01

93

Analysis of options for coal combustion waste management in the Pacific Basin  

Energy Technology Data Exchange (ETDEWEB)

Many Pacific Basin countries rely on oil for electricity production. Alternative fuel sources such as coal, which is available in the Pacific Basin, can help mitigate adverse impacts of sudden price increases or supply disruptions. Coal combustion produces solid and potentially hazardous wastes of concern to environmental regulators and utility managers. This paper identifies issues associated with managing coal combustion wastes in the Pacific Basin, using the state of Hawaii as a case study. Hawaii is typical of many Pacific Basin locations in that it depends on oil, has limited sites, for waste management operations, and is subject to domestic and international waste management regulations. The paper discusses coal-fired utility wastes, environmental impacts of coal combustion waste disposal, and regulatory requirements that impact coal waste management. From this baseline, potential on- and off-island options for coal waste management are identified. Waste ...

1993-10-01

94

A simple model for the short-time evolution of near-surface current and temperature profiles  

CERN Document Server

A simple analytical/numerical model has been developed for computing the evolution, over periods of up to a few hours, of the current and temperature profile in the upper layer of the ocean. The model is based upon conservation laws for heat and momentum, and employs an eddy diffusion parameterisation which is dependent on both the wind speed and the wind stress applied at the sea surface. Other parameters such as the bulk-skin surface temperature difference and CO$_2$ flux are determined by application of the Molecular Oceanic Boundary Layer Model (MOBLAM) of Schluessel and Soloviev. A similar model, for the current profile only, predicts a temporary increase in wave breaking intensity and decrease in wave height under conditions where the wind speed increases suddenly, such as, for example, during gusts and squalls. The model results are compared with measurements from the lagrangian Skin Depth Experimental Profiler (SkinDeEP) surface profiling instrument made ...

2005-01-01

95

Deformation change in light iridium nuclei from laser spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

Laser spectroscopy measurements have been performed on neutron-deficient and stable Ir isotopes using the COMPLIS experimental setup installed at ISOLDE-CERN. The radioactive Ir atoms were obtained from successive decays of a mass-separated Hg beam deposited onto a carbon substrate after deceleration to 1kV and subsequently laser desorbed. A three-color, two-step resonant scheme was used to selectively ionize the desorbed Ir atoms. The hyperfine structure (HFS) and isotope shift (IS) of the first transition of the ionization path 5d{sup 7}6s{sup 24}F{sub 9/2}{yields}5d{sup 7}6s6p{sup 6}F{sub 11/2} at 351.5nm were measured for {sup 182-189}Ir, {sup 186}Ir{sup m} and the stable {sup 191,193}Ir. The nuclear magnetic moments {mu}{sub I} and the spectroscopic quadrupole moments Q{sub s} were obtained from the HFS spectra and the change of the mean square charge radii from the IS measurements. The sign of {mu}{sub I} was experimentally determined for the first time for the masses ...

2006-12-15

96

Washboard modes as ELM-related events in JET  

Energy Technology Data Exchange (ETDEWEB)

Washboard (WB) modes (Smeulders P et al 1999 Plasma Phys. Control. Fusion 41 1303) are a very common edge instability regularly observed in the H-mode regime in JET. They are detected as (normally several) bands of continuously fluctuating magnetic activity rotating in the direction of the electron diamagnetic drift with typical frequencies in the range of 10-90 kHz. The time evolution of the WB mode frequency is found to follow qualitatively the evolution of the electron temperature measured near the pedestal top, probably due to the strong diamagnetic drift associated with the large pedestal gradients. Evidence for their involvement in the pedestal and ELM dynamics will be presented. Increasing WB mode amplitude is correlated with an increase in the time between consecutive type-I ELMs. In situations in which a sudden increase (decrease) of WB mode activity is observed, the build-up of the pedestal temperature (and, linked to this, also of the pedestal pressure) ...

2004-01-01

97

Understanding feline heartworm infection: disease, diagnosis, and treatment.  

Science.gov (United States)

Feline heartworm disease is a very different clinical entity from canine heartworm disease. In cats, the arrival and death of immature heartworms in the pulmonary arteries can cause coughing and dyspnea as early as 3 months postinfection. Adult heartworms suppress the function of pulmonary intravascular macrophages and thus reduce clinical disease in chronic feline heartworm infection. Approximately 80% of asymptomatic cats self-cure. Median survival time for symptomatic cats is 1.5 years, or 4 years if only cats living beyond the day of presentation are considered. Aberrant worm migration is more frequent than it is in dogs, and sudden death can occur with no prior clinical signs. The bacterial endosymbiont Wolbachia likely contributes to the inflammatory pathology of heartworm disease, but its role is not yet fully clear. Unfortunately, the diagnosis, treatment, and management of feline heartworm disease are far from simple. Antemortem diagnosis is hampered by ...

2010-11-01

98

Synfuels from coal: lessons from South Africa  

Energy Technology Data Exchange (ETDEWEB)

The strategy for building SASOL plants reflects a commitment to long-range planning. The first plant, which represented a large investment for a moderate production capacity, was built to establish a technology for reducing South Africa's dependence on imported motor fuels. After the success of the plant, SASOL made plans for a larger plant, which had to be justified solely on economic grounds. At that time, petroleum crude was cheap and plentiful, and the second plant was cancelled. But when OPEC formed and the price of petroleum crude was increased, the South African government reconsidered the plans for another SASOL plant. Furthermore, because the cost of fuels produced at Sasol I proved to be significantly insensitive to inflation and future OPEC price increases were expected, SASOL projected that a new, larger plant should make a profit within a few years after its initial operation. But OPEC prices and inflation have risen even faster than anticipated, and the products ...

1980-01-01

99

Synfuels from coal: lessons from South Africa  

Science.gov (United States)

The strategy for building SASOL plants reflects a commitment to long-range planning. The first plant, which represented a large investment for a moderate production capacity, was built to establish a technology for reducing South Africa's dependence on imported motor fuels. After the success of the plant, SASOL made plans for a larger plant, which had to be justified solely on economic grounds. At that time, petroleum crude was cheap and plentiful, and the second plant was cancelled. But when OPEC formed and the price of petroleum crude was increased, the South African government reconsidered the plans for another SASOL plant. Furthermore, because the cost of fuels produced at Sasol I proved to be significantly insensitive to inflation and future OPEC price increases were expected, SASOL projected that a new, larger plant should make a profit within a few years after its initial operation. But OPEC prices and inflation have risen even faster than anticipated, and the products ...

1980-01-01

100

Study on the measurement method of diffusion coefficient for radon in the soil. 6  

International Nuclear Information System (INIS)

The aim of this study is to clarify the radon behavior in the soil at the waste rock yards of uranium mine. We have developed an apparatus for measuring radon diffusion coefficient in soil under the control of soil temperature. The radon diffusion coefficients changed suddenly around the soil temperature of 0degC. The radon diffusion coefficients in dry soil have little temperature dependency, and were comparable coefficients obtained by empirical formula of Rogers and Nielson. To study the restraint effect of radon exhalation by covering with bentonite on soil, we carried out the measurements and the calculations by using one-dimensional transport model of atmosphere and soil. The decrease of radon exhalation rate was 2.9 Bq m"-"2s"-"1 when soil covered with the bentonite of 5 cm thick. The radon concentrations in snow cover and the radon flux from the snow surface were measured at the waste rock yard in Ningyo-toge Environmental Engineering Center. The simulation ...

 
 
 
 
101

Renal artery stenosis after radiotherapy for Ewing's sarcoma  

International Nuclear Information System (INIS)

Background: the fact that therapeutic irradiation can induce significant stenosis in the arteries of the head, neck, and chest, as welt as in the aorta and the iliac arteries, is familiar in daily practice and well documented in the literature. By contrast, radiation-induced renal artery stenosis seems to be a less widely known complication. Patients and methods: the sudden onset of medically refractory arterial hypertension and coma in a 27-year-old man is reported, who had been treated at age 20 with chemotherapy and radiotherapy for Ewing's sarcoma in the lumbar region. This treatment had been performed at the hospital of Sion, Switzerland in 2001. Also, the relevant literature from 1965 to 2007 is reviewed to underscore various aspects of this problem and to demonstrate the clinical relevance of renal artery stenosis as a potential long-term sequela of radiotherapy. Conclusion: radiation-induced renal artery stenosis has only rarely been described in the ...

2008-09-01

102

Optically stimulated luminescence (OSL) study of synthetic stishovite  

International Nuclear Information System (INIS)

Optically stimulated luminescence (OSL) of synthetic stishovite was investigated for a future dating technique of meteor impact craters. Luminescence around 330 nm was measured on the #gamma#-ray irradiated stishovite under two stimulating light sources of infrared laser (830 nm) and blue light emitting diode set (470 nm). Thermoluminescence (TL) studies before and after the OSL measurements showed the intensities around 100-200 deg. C and 220-350 deg. C to increase and those around 350-450 deg. C to decrease. This indicates that a part of deep-trapped charges excited during the OSL measurements were retrapped by shallower traps. The infrared stimulated luminescence (IRSL) after the TL measurement up to 450 deg. C could not be detected, while the blue light stimulated luminescence (BLSL) after TL had about one-tenth of the intensity before TL. This indicates that a part of the charges in shallower traps were detrapped thermally and returned to the deeper traps which were related to ...

2000-12-15

103

New Forming Limits For Light Alloys By Means Of Electromagnetic Forming And Numerical Simulation Of The Process  

Science.gov (United States)

It is well known that one of the main advantages of the high speed forming (HSF) processes is the improvement in the forming limits of the used materials.Using the Electromagnetic Forming (EMF) technology two materials have been tested with different mechanical and physical properties: the AA5754 aluminium and the AZ31B magnesium alloys.The EMF process principle can be described as follows: A significant amount of electrical energy is stored in a bank of capacitors which are suddenly discharged releasing all the stored energy. This electric discharge runs through a coil which generates an intense transient magnetic field. At the same time transient Eddy currents are induced in the electrically conductive part placed some millimetres far from the coil. Another intense magnetic field is generated due to those Eddy currents but on the opposite direction as the one generated by the coil. A big magnetic repulsion force is created between the part and the coil. This ...

2007-04-07

104

New Forming Limits For Light Alloys By Means Of Electromagnetic Forming And Numerical Simulation Of The Process  

International Nuclear Information System (INIS)

It is well known that one of the main advantages of the high speed forming (HSF) processes is the improvement in the forming limits of the used materials.Using the Electromagnetic Forming (EMF) technology two materials have been tested with different mechanical and physical properties: the AA5754 aluminium and the AZ31B magnesium alloys.The EMF process principle can be described as follows: A significant amount of electrical energy is stored in a bank of capacitors which are suddenly discharged releasing all the stored energy. This electric discharge runs through a coil which generates an intense transient magnetic field. At the same time transient Eddy currents are induced in the electrically conductive part placed some millimetres far from the coil. Another intense magnetic field is generated due to those Eddy currents but on the opposite direction as the one generated by the coil. A big magnetic repulsion force is created between the part and the coil. This ...

2007-04-07

105

Magnetic and thermal properties of cubic single-crystal PrCu_4Ag  

International Nuclear Information System (INIS)

We succeeded in synthesizing a new cubic intermetallic compound PrCu_4Ag in a fcc structure. Measurements of X-ray diffraction, magnetic susceptibility, magnetization, specific heat, electrical resistivity, thermal expansion, and elastic constants have been performed on single crystals of PrCu_4Ag. A maximum value of #chi#(T) with a corresponding peak in C(T) suggests that an antiferromagnetic phase transition occurs at T_N=2.4 K, where a sudden decrease in #rho#_4_f(T) and a sharp peak in the thermal expansion coefficient #alpha#(T) were observed. Characteristic Curie-type softening was observed in the temperature dependence of the transverse mode for (C_1_1 - C_1_2)/2 and C_4_4 from 70 K down to T_N, which implies that the crystalline electric field (CEF) ground state is the magnetic triplet #GAMMA#_5. The anisotropic properties in M(T,H) and C(T,H) are studied when the external magnetic field is applied in the <100>, <110>, and <111> ...

2010-11-01

106

Late-onset Stargardt-like macular dystrophy maps to chromosome 1p13  

Energy Technology Data Exchange (ETDEWEB)

Stargardt`s disease (MIM 248200), originally described in 1909, is an autosomal recessive condition of childhood, characterized by a sudden and bilateral loss of central vision. Typically, it has an early onset (7 to 12 years), a rapidly progressive course and a poor final outcome. The central area of the retina (macula) displays pigmentary changes in a ring form with depigmentation and atrophy of the retinal pigmentary epithelium (RPE). Perimacular yellowish spots, termed fundus flavimaculatus, are observed in a high percentage of patients. We have recently reported the genetic mapping of Stargardt`s disease to chromosome 1p13. On the other hand, considering that fundus flavimaculatus (MIM 230100) is another form of fleck fundus disease, with a Stargardt-like retinal aspect but with a late-onset and a more progressive course, we decided to test the hypothesis of allelism between typical Stargardt`s disease and late-onset autosomal recessive fundus flavimaculatus. ...

1994-09-01

107

Gas-liquid two-phase flow patterns in parallel channels for fuel cells  

Energy Technology Data Exchange (ETDEWEB)

Two-phase flow in horizontal parallel channels has been experimentally investigated under fuel cell related operating conditions. Pronounced hysteresis is observed in the pressure drop versus flow characteristic curve when starting from either flooded or dry conditions. When gas is introduced into channels initially filled with water (flooded initial condition), both gas and liquid tend to flow predominantly in one channel at low gas or liquid flow velocities. As the gas flow velocity increases, even distribution of gas and liquid flow in both channels is observed, accompanied with a sudden decrease in the pressure drop. On the other hand, even gas and liquid flow distribution between both channels is found at comparatively lower gas flow velocities when starting with dry-gas flow conditions with liquid introduced into channels filled with gas (stratified flow regime). The flow regimes of this system are visualized in plots of the pressure drop against gas and ...

2008-09-01

108

Full scale heavily reinforced concrete beam-column joints of NPP structures-quality assurance and construction in the laboratory  

International Nuclear Information System (INIS)

Under the current design philosophy, reactor structures are to be designed to withstand large inelastic deformation caused by strong and severe ground motion. The design of the main structural elements and their connections are to be such that they always fail in ductile mode. This will ensure large energy absorption capacity of the structures under seismic excitation and avoid sudden and brittle failure of the structure. Over the years, a number of experimental investigations have been carried out on RC beam- column joints to study their behaviour and strength. However, these studies mostly pertain to small scale joints of moment resisting frame of residential buildings and commercial complexes. Information on full scale joints existing in NPP structures are scanty. Therefore, experimental programme was planned in the laboratory to construct identical large sized joints with the same reinforcement percentage and detail as that of the existing joints in NPP ...

2003-02-01

109

Development of experimental verification techniques for non-linear deformation and fracture on the nanometer scale.  

Energy Technology Data Exchange (ETDEWEB)

This work covers three distinct aspects of deformation and fracture during indentations. In particular, we develop an approach to verification of nanoindentation induced film fracture in hard film/soft substrate systems; we examine the ability to perform these experiments in harsh environments; we investigate the methods by which the resulting deformation from indentation can be quantified and correlated to computational simulations, and we examine the onset of plasticity during indentation testing. First, nanoindentation was utilized to induce fracture of brittle thin oxide films on compliant substrates. During the indentation, a load is applied and the penetration depth is continuously measured. A sudden discontinuity, indicative of film fracture, was observed upon the loading portion of the load-depth curve. The mechanical properties of thermally grown oxide films on various substrates were calculated using two different numerical methods. The first method ...

2005-11-01

110

Determination of a various ions such as alkali metals in leaves, stems, roots and seeds of the radish and their distribution  

Energy Technology Data Exchange (ETDEWEB)

Determination, uptake and distribution of various ions such as alkali metals in three different parts (leaf, stem and root) and seeds of radish (Kaiware daikon) were examined using flame emission spectrometry and ICP-AES. In order to examine the influence of concentration alkali metal ion concentration in the radish culture solution on the uptake and distribution of these metals, the radish was grown at pH 5.6 in solutions containing alkali metal chloride at concentrations ranging from 10{sup -5} to 10{sup -1} mol dm{sup -3}. When the radish were grown in culture solution with alkali metal ions of low concentrations (10{sup -5} and 10{sup -4} mol dm{sup -3}), Na, K, Rb and trace Li were detected in leaves, stems and roots while Cs was scarcely detected. However, the contents of Na, K, Li in these organs were the same as those in radish cultivated in pure water. An increase of Rb uptake was observed with an increased Rb concentration. In the case of high concentrations (10{sup -3} and ...

1995-05-01

111

Deformation change in light iridium nuclei from laser spectroscopy  

International Nuclear Information System (INIS)

Laser spectroscopy measurements have been performed on neutron-deficient and stable Ir isotopes using the COMPLIS experimental setup installed at ISOLDE-CERN. The radioactive Ir atoms were obtained from successive decays of a mass-separated Hg beam deposited onto a carbon substrate after deceleration to 1kV and subsequently laser desorbed. A three-color, two-step resonant scheme was used to selectively ionize the desorbed Ir atoms. The hyperfine structure (HFS) and isotope shift (IS) of the first transition of the ionization path 5d"76s"2"4F_9_/_2#->#5d"76s6p"6F_1_1_/_2 at 351.5nm were measured for "1"8"2"-"1"8"9Ir, "1"8"6Ir"m and the stable "1"9"1","1"9"3Ir. The nuclear magnetic moments #mu#_I and the spectroscopic quadrupole moments Q_s were obtained from the HFS spectra and the change of the mean square charge radii from the IS measurements. The sign of #mu#_I was experimentally determined for the first time for the masses 182#=#+0.2 for the lighter group A=186g, 185, 184, 183 ...

2006-12-01

112

Contribution to the experimental study of the polarized liquid helium-3; Contributions a l'etude experimentale de l'helium-3 liquide polarise  

Energy Technology Data Exchange (ETDEWEB)

Spin-polarized liquid helium-3 is prepared by laser optical pumping in low magnetic field and at room temperature, prior to fast liquefaction of the polarized sample. The use of a new helium-3 cryostat enabled us to obtain liquid helium-3 with polarization rates up to 25 % at well-stabilized temperatures (around 0.5 K). We could thereby study the effect of nuclear polarization on liquid-vapour equilibrium, and particularly on the saturated vapour pressure. Very sensitive capacitive gauges were developed. We estimated (to first order in M{sup 2}) the expected effects when the polarization M is suddenly destroyed. These effects were experimentally observed in helium-3/helium-4 mixtures, in pure helium-3, only a transient increase in pressure has been recorded. We then describe in a third part a preliminary experiment which aimed at determining the longitudinal relaxation time T1 in mixtures. Relaxation on the walls is efficiently reduced by a cesium coating and T1s ...

1999-07-15

113

Code requirements document: MODFLOW 2.1: A program for predicting moderator flow patterns  

Energy Technology Data Exchange (ETDEWEB)

Sudden changes in the temperature of flowing liquids can result in transient buoyancy forces which strongly impact the flow hydrodynamics via flow stratification. These effects have been studied for the case of potential flow of stratified liquids to line sinks, but not for moderator flow in SRS reactors. Standard codes, such as TRAC and COMMIX, do not have the capability to capture the stratification effect, due to strong numerical diffusion which smears away the hot/cold fluid interface. A related problem with standard codes is the inability to track plumes injected into the liquid flow, again due to numerical diffusion. The combined effects of buoyant stratification and plume dispersion have been identified as being important in operation of the Supplementary Safety System which injects neutron-poison ink into SRS reactors to provide safe shutdown in the event of safety rod failure. The MODFLOW code discussed here provides transient moderator flow pattern ...

1992-03-01

114

Code requirements document: MODFLOW 2. 1: A program for predicting moderator flow patterns  

Energy Technology Data Exchange (ETDEWEB)

Sudden changes in the temperature of flowing liquids can result in transient buoyancy forces which strongly impact the flow hydrodynamics via flow stratification. These effects have been studied for the case of potential flow of stratified liquids to line sinks, but not for moderator flow in SRS reactors. Standard codes, such as TRAC and COMMIX, do not have the capability to capture the stratification effect, due to strong numerical diffusion which smears away the hot/cold fluid interface. A related problem with standard codes is the inability to track plumes injected into the liquid flow, again due to numerical diffusion. The combined effects of buoyant stratification and plume dispersion have been identified as being important in operation of the Supplementary Safety System which injects neutron-poison ink into SRS reactors to provide safe shutdown in the event of safety rod failure. The MODFLOW code discussed here provides transient moderator flow pattern ...

1992-03-01

115

CHEMICAL TECHNOLOGY DIVISION, UNIT OPERATIONS SECTION MONTHLY PROGRESS REPORT, JULY 1960  

Science.gov (United States)

A critical review of the literature revealed no experiments on uranyl ion transfer from an aqueous to a tributyl phosphate phase which positively measured the kinetics of the chemical reaction at the interphase. Drawing isorhythmic lines on a three component diagram gives a complex correlation for the compaction of three sizes of glass beads. Neither the use of thoria sols nor high feed solution concentrations of thorium nitrate gave any significant increase in mean particle diameters over those obtained from nitrate solutions of lower concentrations in flame denitration. A hydraulic film resistance has been detected in the anion exchange of uranyl sulfate into Dowex 2lK, and chloride elution was found to give a higher apparent uranium diffusion coefficient than nitrate elution. The rate of dissolution of mixed thorium-uranium oxides was determined as a function of the per cent of mixed oxides dissolved. Mixing in tanks packed with boron glass Raschig rings ...

1960-10-27

116

An analysis on the mid-latitude scintillation and coherence frequency bandwidth using transionospheric VHF signals  

Energy Technology Data Exchange (ETDEWEB)

An analysis was perfonned on the mid-latitude scintillation and coherence frequency bandwidth (Fcoh) using transionospheric VHF signal data. The data include 1062 events spanning from November 1997 to June 2002. Each event records FORTE satellite received VHF signals from LAPP located at Los Alamos, New Mexico. Fcohs were derived to study scintillation characteristics on diurnal and seasonal variations, as well as changes due to solar and geomagnetic activities. Comparisons to the VHFIUHF coherence frequency bandwidth studies previously reported at equatorial and mid-latitude regions are made using a 4th power frequency dependence relationship. Furthennore, a wideband ionospheric scintillation model, WBMOD, was used to estimate Fcohs and compared with our VHF Fcoh values. Our analysis indicates mid-latitude scintillation characteristics that are not previously revealed. At the VHF bottom frequency range (3035 MHz), distinguished smaller Fcohs are found in time period from sunset to ...

2008-01-01

117

Transcutaneous oximetry compared to ankle-brachial-index measurement in the evaluation of percutaneous transluminal angioplasty  

International Nuclear Information System (INIS)

Objective: To investigate transcutaneous oximetry as parameter of the microcirculation is correlated to ankle-brachial-index as parameter of the macrocirculation after peripheral angioplasty procedures. Design: Prospective study. Materials and methods: 60 patients suffering from intermittent claudication were scheduled for angioplasty treatment. 45 patients were considered as eligible for angioplasty after angiographic evaluation, 15 patients underwent angiography only. Transcutaneous oximetry measurements were performed before the procedure, at the end of intervention, 24 h as well as 2 and 4 weeks after percutaneous transluminal angioplasty. Ankle-brachial-indices were obtained before intervention, 24 h as well as 2 and 4 weeks later. Results: Ankle-brachial-indices increased significantly at 24 h after angioplasty in patients being treated with angioplasty. Transcutaneous oximetry values dropped significantly at the end of the procedure and returned close to the baseline levels at 2 ...

2007-11-01

118

Challenges in commissioning and operation of 'first-of -its- kind' liquid zone control system in TAPP-3 and 4  

International Nuclear Information System (INIS)

Liquid Zone Control (LZC) System is a 'first-of-its-kind' reactivity control device, designed and implemented at TAPP-3 and 4. The system provides zonal and bulk power control. The system consists of fourteen Zone Control Compartments (ZCCs) containing demineralised light water as neutron absorber. Reactivity control is achieved by varying the level of water in the compartments bi-directionally. Six in-core zircaloy assemblies, housing the fourteen ZCCs and an elaborate process system constitute the LZC system. Measurement of water levels in the ZCCs is done using helium bubbler method. Reliability of ZCC water level measurement is of paramount importance. Commissioning and operating the new system trouble free was a challenge, considering the complex nature of the system. While commissioning the system, level measurement of one of the ZCCs (ZCC - 1) was found erratic and inconsistent. Methodologies were developed to identify the problem and investigations revealed leakage of helium ...

2006-11-13