bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Behavior of a Poroelastic Seabed Under Normal and Shear
Loads
Authors: Sabin G. C. W. 
Published: November 2009

Abstract
One of the effects of ice and water forces on large offshore structures which rest on the seabed is to transmit surface tractions to the region of contact. A recent paper by Sabin and Raman-Nair [1] has examined the effect of a normal axisymmetric load P(r, t) on a poroelastic seabed under several different conditions of boundary permeabilities. That study provided a number of general formulas for an arbitrary normal load. The present paper extends the results found in [1] to include shear tractions. While reference [1] was primarily a theoretical discussion, the present paper examines several specific forms of loading and presents graphs showing the normal stress and pore pressure response for various values of the parameters of interest. These results are compared with the limiting case of an extended period of time.
Structural Modeling of Undersea Cables
Authors: Knapp R. H. 
Published: November 2009

Abstract
A structural model for undersea cables is described. This model has been implemented in a computer-aided design program with the capability to determine cable deformations and internal stresses in response to applied loads including tension, twist, bending, pressure and enforced displacements. Complex geometries and nonlinearly elastic material properties can also be treated. Results of a comprehensive series of physical cable tests to validate the computer code are reported.
Performance of a Closed-Tube Aerosyphon With Large Length-Diameter
Ratios
Authors: Lock G. S. H. , Kirchner J. D. 
Published: November 2009

Abstract
The paper reports an experimental investigation of heat transfer in the closed-tube aerosyphon (aerated-thermosyphon) for a range of conditions representative of northern field applications. In particular, attention is focused on the effect of using tubes with heated lengths not only greater than the cooled lengths, but very much greater than the tube diameter. Using three heated sections and one cooled section, the geometry of the device has been varied systematically with 10 &lt; LH/d &lt; 50 and 1 &lt; LH/LC &lt; 20. For any given geometry, the effect of air bubbling rate has been studied in the range of 0 &lt; V˙ &lt; 5 × 10−5 m3/S. Using these ranges it has been possible to make comparisons with other thermosyphon and aerosyphon data. The results indicate that heat transfer coefficients are reduced by increasing either length-diameter ratio or heated-cooled length ratio. They also reveal that, in general terms, the aerosyphon is almost an order-of-magnitude more effective than the single-phase thermosyphon. Some obervations on the flow regimes are offered, and an empirical correlation is presented.
Evaluation of Occupant Accelerations in Lifeboats
Authors: Nelson J. K. , Hirsch T. J. , Phillips N. S. 
Published: November 2009

Abstract
During the certification of lifeboats for use as a lifesaving appliance, certain impact tests are required to evaluate the strength of the system and the occupant’s exposure to accelerations. The purpose of this paper is to present a rational procedure to infer the potential for these impact accelerations to cause injury to the occupants of conventional and free-fall lifeboats.
A Parametric Study of Fracture Toughness of Fibrous Composite
Materials
Authors: Poe C. C. 
Published: November 2009

Abstract
Impacts to fibrous composite laminates by objects with low velocities can break fibers giving cracklike damage. The damage may not extend completely through a thick laminate. The tension strength of these damaged laminates is reduced much as is that of cracked metals. The fracture toughness depends on fiber and matrix properties, fiber orientations, and stacking sequence. Accordingly, a parametric study was made to determine how fiber and matrix properties and fiber orientations affect fracture toughness and notch sensitivity. The values of fracture toughness were predicted from the elastic constants of the laminate and the failing strain of the fibers using a general fracture toughness parameter developed previously. For a variety of laminates, values of fracture toughness from tests of center-cracked specimens and values of residual strength from tests of thick laminates with surface cracks were compared to the predictions to give credibility to the study. In contrast to the usual behavior of metals, it is shown that both ultimate tensile strength and fracture toughness of composites can be increased without increasing notch sensitivity, and that laminates with surface cracks can fail in two stages, giving some degree of redundancy.
Crack Initiation Under Low-Cycle Multiaxial Fatigue in Type 316L Stainless Steel
Authors: Jacquelin B. , Hourlier F. , Pineau A. 
Published: November 2009

Low-cycle fatigue tests corresponding to fatigue life range between 103 and 105 cycles were carried out at room temperature on one heat of 316 L austenitic stainless steel. These tests included: (i) reversed tension-compression, (ii) reversed tension-compression with a superimposed steady torque, (iii) pulsated tension-compression with a stress ratio (Rσ) such that −0.5<Rσ<0, (iv) reversed and pulsated tension-compression with a superimposed steady internal pressure. In tests (ii), the torsional ratcheting effect was measured. SEM observations were used to determine the number of cycles corresponding to Stage I crack initiation and the orientation of Stage I microcracks. It was observed that the in-depth growing Type B shear microcracks were most damaging. A simple criterion is proposed Ni=No(Δγp B)α•(σnB)β where Ni is the number of cycles to crack initiation, Δγp B is the range of plastic shear strain on Type B planes, σnB is the maximum normal stress acting on these planes, No,α and β are parameters adjusted from the Manson-Coffin law and reversed cyclic stress-strain behavior.
An Evaluation of Several Constitutive Model Structures for Transient
Nonproportional Cyclic Plasticity
Authors: Sotolongo W. , McDowell D. L. 
Published: November 2009

Abstract
Four constitutive models for cyclic plasticity of different essential structure are evaluated under conditions of nonproportional, multiaxial loading. Drucker’s one-surface theory, McDowell’s two-surface theory, Krieg’s one-surface theory with Radial-Return Integration Algorithm, and Abrahamson’s Unified Creep-Plasticity theory are the constitutive models under consideration. Their transient hardening and stable loop responses are compared to experimental data for two nonproportional axial-torsional loading histories. Their computational efficiency is also analyzed.
Results From Dynamic Tests and Analyses of a Medium Diameter LMFBR
Piping System
Authors: Schott G. A. , Hulbert G. M. , Heberling C. F. 
Published: November 2009

Abstract
This paper presents results and observations from dynamic tests and analyses performed on an 8-in. (0.20-m) diameter, thin-walled piping system. The piping system is a scaled representation of a Liquid Metal Fast Breeder Reactor (LMFBR) large diameter piping loop. Prototypic piping restraints were employed, including mechanical snubbers, rigid struts, pipe hangers and nonintegral pipe clamps. Snap-back, sine-sweep and seismic tests were performed for various restraint configurations and piping conditions. The test results are compared to analytical predictions for verification of the methods and models used in the seismic design of LMFBR piping systems. Test program conclusions and general recommendations for piping seismic analyses are presented along with a discussion of test and analysis results.
Emergency Response Guidance for Reactor Vessel Pressurized Thermal
Shock Events
Authors: Kaiser W. T. , Monty B. S. 
Published: November 2009

Abstract
The operational concern of pressurized thermal shock (PTS) can be minimized by proper operator guidance. This paper presents a method for calculating a pressure temperature limit curve for reactor vessel integrity which can be used to identify an ongoing potential PTS event. This method has been developed for use and is applicable to all pressurized water reactors. The curve is used in emergency operating procedures developed to prioritize various plant safety concerns including PTS and core cooling to ensure proper operator action during accident conditions. This paper emphasizes the development of the pressure-temperature limit and how it is used within the emergency operating procedures.
The Dynamics of Heat Exchanger U-Bend Tubes With Flat Bar
Supports
Authors: Yetisir M. , Weaver D. S. 
Published: November 2009

Abstract
A theoretical study has been conducted to investigate the effect of flat bar supports on the dynamic response of a heat exchanger U-tube. The tube was modeled using 3-D, six degrees of freedom per node beam finite elements and excited at its lowest three natural frequencies. The equations of motion were integrated and the time response was analysed using a Fast Fourier Transform Algorithm. The modal frequency and dissipation contributions were determined and the effects of support friction and clearance and excitation magnitude were investigated.
Heat Conduction Through a Layered Pressure Vessel
Wall
Authors: Ueda M. , Kinugawa M. , Hara Y. , Yamazato K. 
Published: November 2009

Abstract
Heat conduction tests of a layered pressure vessel wall were performed using full-scale model pressure vessel courses. Thermal conductance between layers was estimated from the test results. A simplified method, developed for the thermal analysis of layered-wall pressure vessels during postweld heat treatment and actual operation, includes thermal contact conductance at the layer interfaces which depends upon the contact pressure and gap height. Temperature changes calculated using the simplified method agreed well with the experiments.
Numerical Estimate of Elastic Follow-Up in Piping: Inelastic
Evaluation
Authors: Dhalla A. K. 
Published: November 2009

Abstract
Large-diameter thin-walled piping such as that used in the Liquid Metal Fast Breeder Reactor (LMFBR) plant is characterized by relatively stiff straight pipes welded to flexible elbows. According to Robinson [1], such a piping system configuration may experience elastic follow-up during elevated temperature operation. Therefore, ASME Code Case N-47 requires that the secondary thermal expansion stress “. . . with large amounts of elastic follow-up . . .” be considered a load-controlled primary stress. A procedure to calculate the extent of potential elastic follow-up and thereby classify the thermal expansion stress as either primary or secondary is presented here. The elastic follow-up effect is investigated in detail by evaluating spatial and temporal redistribution of loads and inelastic strains computed for a typical LMFBR piping system.
Verification of an Elastic Procedure to Estimate Elastic
Follow-Up
Authors: Dhalla A. K. 
Published: November 2009

Abstract
This paper presents a simplified elastic procedure to estimate the amount of elastic follow-up due to thermal expansion stress experienced by a large diameter (greater than 200 mm) thin-walled (d/t greater than 30) piping system. The simplified method utilizes the concept of reduced elastic modulus which was successfully applied to classify clamp-induced pipe stresses into primary and secondary categories. The conservatism of the simplified method in quantifying elastic follow-up is illustrated in this paper by comparing the numerical estimate of elastic follow-up with that obtained from a detailed creep analysis of a Liquid Metal Fast Breeder Reactor piping system.
Recertification of Pressure Vessels and Pressure
Systems
Authors: Selz A. 
Published: November 2009

Abstract
There are strong economic and safety incentives to recertify pressure vessels, pressure components, and piping for continued service after their nominal original design life has been exhausted. No specific rules, and certainly no national consensus standards exist for doing this. Therefore, methods have been developed to rank vessels as to urgency for recertification, and a five-step recertification process has been devised. The five steps are: 1) gathering design and operating information, 2) performing basic analysis to establish maximum allowable working pressure (MAWP) and to identify high-stress areas, 3) performing visual and nondestructive examination, concentrating NDT in high stress areas, 4) performing detailed stress analysis to confirm MAWP, and 5) performing flaw-growth analysis to establish the interval between inspections. Experience has shown that recertification costs are between 10 and 15 percent of replacement costs and that recertification adds greatly to confidence in the safety and availability of equipment.
A Simple Design Equation for Preventing Buckling in Fabricated
Torispherical Shells Under Internal Pressure
Authors: Galletly G. D. 
Published: November 2009

Abstract
A simple equation is proposed which will enable a designer to estimate the onset of buckling in internally pressurized steel torispherical end closures. The equation applies to both crown and segment ends and spun ones. Apart from a factor which accounts for strain hardening, the same equation applies to both carbon steel and austenitic stainless steel torispheres. The proposed equation for the allowable internal pressure was checked against all known experimental buckling results and a minimum factor of safety of 1.5 was found. The equation was also checked against a number of full-scale vessels, some of which had failed in service. Once again, the equation was found to be satisfactory.
RMS Fatigue Curves for Random Vibrations
Authors: Brenneman B. , Talley J. Q. 
Published: November 2009

Abstract
Fatigue usage factors for deterministic or constant amplitude vibration stresses may be calculated with well-known procedures and fatigue curves given in the ASME Boiler and Pressure Vessel Code. However, some phenomena produce nondeterministic cyclic stresses which can only be described and analyzed with statistical concepts and methods. Such stresses may be caused by turbulent fluid flow over a structure. Previous methods for solving this statistical fatigue problem are often difficut to use and may yield inaccurate results. Two such methods examined herein are Crandall’s method and the “3σ” method. The objective of this paper is to provide a method for creating “RMS” fatigue curves” which accurately incorporate the requisite statistical information. These curves are given in Appendix A and may be used by analysts with the same ease and in the same manner as the ASME fatigue curves.
Impacting of Pipes on Elastic Supports
Authors: Kumar R. 
Published: November 2009

Abstract
Piping systems are often provided with supports and restraints with gaps to reduce the thermal stresses and to limit the motion caused by other loads, e.g., due to pipe rupture or seismic effects. However, the presence of the gap causes the pipe to impact on the support under dynamic loading. In this paper the impacting effects have been studied using a simple model. The effect of support rigidity on the impact force, bending moment and deflection of the pipe has been evaluated. The bending moment at the impact loading is found to decrease up to a certain value of the support stiffness beyond which it increases. However, the impact force increases and the overall deflection at the impact location decreases continuously as the support stiffness is increased. The results are presented in nondimensional form as ratios of the appropriate quantities for the simply supported pipe with no elastic restraint. Thus, they provide useful information for design considering impact effects.
Novel VIM Metallo-β-Lactamase Variant from Clinical Isolates of
Enterobacteriaceae
from Algeria
Authors: Robin Frédéric , Aggoune-Khinache Nadjet , Delmas Julien , Naim Malek , Bonnet Richard 
Published: November 2009

ABSTRACT

Five different strains of bacteria belonging to the family
Enterobacteriaceae
were isolated from two patients hospitalized in the intensive care unit of the Central Military Hospital of Algiers, Algeria. All five strains, one
Providencia stuartii
strain, two
Escherichia coli
strains, and two
Klebsiella pneumoniae
strains, were intermediate or resistant to all β-lactams, including carbapenems. Synergy between imipenem and EDTA was observed for all five strains. The results of the PCR experiment confirmed the presence of a
bla
VIM
gene in all five strains. The
bla
VIM
genes were located as part of a class 1 integron on a 180-kb conjugative plasmid. They encoded a novel metallo-β-lactamase designated VIM-19, which differed from the parental enzyme VIM-1 by only two substitutions: Ser228Arg, previously observed in the closely related enzyme VIM-4, and Asn215Lys, not previously observed in other VIM-type carbapenemases. VIM-19 was further characterized after purification through determination of its kinetic constants. This enzyme was inhibited by EDTA and hydrolyzed penicillins, cephalosporins, and carbapenems, as observed for other VIM-type carbapenemases but with greater catalytic efficiency against penicillins than VIM-1. VIM-19 is the first carbapenemase enzyme identified from an isolate from Algeria. These results confirm the emergence of VIM-4-like enzymes in members of the family
Enterobacteriaceae
from Mediterranean countries.
Factors Associated with Virological Response to Etravirine in Nonnucleoside Reverse Transcriptase Inhibitor-Experienced HIV-1-Infected Patients
Authors: Marcelin Anne-Genevieve , Flandre Philippe , Descamps Diane , Morand-Joubert Laurence , Charpentier Charlotte , Izopet Jacques , Trabaud Mary-Anne , Saoudin Henia , Delaugerre Constance , Tamalet Catherine , Cottalorda Jacqueline , Bouvier-Alias Magali , Bettinger Dominique , Dos Santos Georges , Ruffault Annick , Alloui Chakib , Henquell Cecile , Rogez Sylvie , Barin Francis , Signori-Schmuck Anne , Vallet Sophie , Masquelier Bernard , Calvez Vincent 
Published: November 2009

ABSTRACTTo identify factors associated with virological response (VR) to an etravirine (ETR)-based regimen, 243 patients previously treated with nonnucleoside reverse transcriptase inhibitors (NNRTIs) were studied. The impact of baseline HIV-1 RNA, CD4 cell count, past NNRTIs used, 57 NNRTI resistance mutations, genotypic sensitivity score (GSS) for nucleoside reverse transcriptase inhibitors (NRTIs) and protease inhibitors (PIs), and the number of new drugs used with ETR for the first time on the VR to an ETR regimen were investigated. Among the 243 patients, the median baseline HIV-1 RNA level was 4.4 log10copies/ml (interquartile range [IQR], 3.7 to 4.9) and the median CD4 count was 175 cells/mm3(IQR, 69 to 312). Patients had been previously exposed to a median of 6 NRTIs, 1, NNRTI, and 5 PIs. Overall, 82% of patients achieved a VR at month 2, as defined by a decrease of at least 1.5 log10copies/ml and/or HIV-1 RNA level of <50 copies/ml. No difference in VR was observed between patients receiving or not a boosted PI in combination with ETR. Factors independently associated with a better VR to ETR were the number of drugs (among enfuvirtide, darunavir, or raltegravir) used for the first time in combination with ETR and the presence of the K103N mutation at baseline. Mutations Y181V and E138A were independently associated with poor VR, whereas no effect of the Y181C on VR was observed. In conclusion, ETR was associated with high response rates in NNRTI-experienced patients in combination with other active drugs regardless of the therapeutic class used.
A Novel Class of
meso
-Tetrakis-Porphyrin Derivatives Exhibits Potent Activities against Hepatitis C Virus Genotype 1b Replicons
In Vitro
Authors: Cheng Yao , Tsou Lun K. , Cai Jianfeng , Aya Toshihiro , Dutschman Ginger E. , Gullen Elizabeth A. , Grill Susan P. , Chen Annie Pei-Chun , Lindenbach Brett D. , Hamilton Andrew D. , Cheng Yung-chi 
Published: November 2009

ABSTRACT

Recent years have seen the rapid advancement of new therapeutic agents against hepatitis C virus (HCV) in response to the need for treatment that is unmet by interferon (IFN)-based therapies. Most antiviral drugs discovered to date are small molecules that modulate viral enzyme activities. In the search for highly selective protein-binding molecules capable of disrupting the viral life cycle, we have identified a class of anionic tetraphenylporphyrins as potent and specific inhibitors of the HCV replicons. Based on the structure-activity relationship studies reported herein,
meso
-tetrakis-(3,5-dicarboxy-4,4′-biphenyl) porphyrin was found to be the most potent inhibitor of HCV genotype 1b (Con1) replicon systems but was less effective against the genotype 2a (JFH-1) replicon. This compound induced a reduction of viral RNA and protein levels when acting in the low nanomolar range. Moreover, the compound could suppress replicon rebound in drug-treated cells and exhibited additive to synergistic effects when combined with protease inhibitor BILN 2061 or with IFN-α-2a. Our results demonstrate the potential use of tetracarboxyphenylporphyrins as potent anti-HCV agents.
Baculovirus-Based Nasal Drop Vaccine Confers Complete Protection against Malaria by Natural Boosting of Vaccine-Induced Antibodies in Mice
Authors: Yoshida Shigeto , Araki Hitomi , Yokomine Takashi 
Published: November 2009

ABSTRACTBlood-stage malaria parasites ablate memory B cells generated by vaccination in mice, resulting in diminishing natural boosting of vaccine-induced antibody responses to infection. Here we show the development of a new vaccine comprising a baculovirus-basedPlasmodium yoelii19-kDa carboxyl terminus of merozoite surface protein 1 (PyMSP119) capable of circumventing the tactics of parasites in a murine model. The baculovirus-based vaccine displayed PyMSP119on the surface of the virus envelope in its native three-dimensional structure. Needle-free intranasal immunization of mice with the baculovirus-based vaccine induced strong systemic humoral immune responses with high titers of PyMSP119-specific antibodies. Most importantly, this vaccine conferred complete protection by natural boosting of vaccine-induced PyMSP119-specific antibody responses shortly after challenge. The protective mechanism is a mixed Th1/Th2-type immunity, which is associated with the Toll-like receptor 9 (TLR9)-dependent pathway. The present study offers a novel strategy for the development of malaria blood-stage vaccines capable of naturally boosting vaccine-induced antibody responses to infection.
CXCL10 Production by Human Monocytes in Response to
Leishmania braziliensis
Infection
Authors: Vargas-Inchaustegui Diego A. , Hogg Alison E. , Tulliano Gianfranco , Llanos-Cuentas Alejandro , Arevalo Jorge , Endsley Janice J. , Soong Lynn 
Published: November 2009

ABSTRACT

Leishmania
(subgenus
Viannia
)
braziliensis
is the causative agent of mucocutaneous leishmaniasis (ML) in South America, and ML is characterized by excessive T- and B-cell responses to the parasite. We speculate that the unbalanced production of inflammatory mediators in response to
L
.
braziliensis
infection contributes to cell recruitment and disease severity. To test this hypothesis, we first examined the response of peripheral blood mononuclear cells (PBMCs) from healthy volunteers to
L
.
braziliensis
infection. We observed that while
L
.
braziliensis
infection induced the production of chemokine (C-X-C motif) ligand 10 (CXCL10) and interleukin-10 (IL-10) in human PBMCs and macrophages (MΦs), enhanced expression of CXCL10 and its receptor, chemokine CXC receptor (CXCR3), was predominantly detected in CD14
+
monocytes. The chemoattractant factors secreted by
L
.
braziliensis
-infected cells were highly efficient in recruiting uninfected PBMCs (predominantly CD14
+
cells) through Transwell membranes. Serum samples from American tegumentary leishmaniasis (ATL) patients (especially the ML cases) had significantly higher levels of CXCL10, CCL4, and soluble tumor necrosis factor (TNF) receptor II (sTNFRII) than did those of control subjects. Our results suggest that, following
L
.
braziliensis
infection, the production of multiple inflammatory mediators by the host may contribute to disease severity by increasing cellular recruitment.