bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical Evaluation of a Limited Number of Fatigue Test Specimens Including a Factor of Safety Approach
Authors: Albrecht C. O.
Published: September 2009

Many full-scale component fatigue limits are developed on the basis of less than five tests. Use of statistical concepts on such a limited number of specimens would result in extremely low and unrealistic allowable stresses for any reasonable probability and confidence level.

Fatigue data from element tests and full-scale component tests, where many specimens have been tested, can be used to evaluate a coefficient of variation that is representative of the material and type of component being considered. By use of this information, and with the application of basic statistical techniques, a design S-N-P (probability) curve can be determined for components where only a limited number of tests are available, for any probability and confidence level desired. The methods employed for the evaluation of available data are discussed.

Typical values of coefficient of variation are tabulated for components of typical steel and aluminum alloys such as 4130 and 4340 alloy steel, 150,000 to 160,000 psi ultimate tensile strength, and 2024-T4, 2014-T6, and 7075-T6 aluminum alloys, which contain stress concentrations or areas of fretting corrosion or both.

Suitable probability and confidence levels are selected for components where a single noninspectable failure would result in a catastrophic loss.

Determination of a design fatigue limit can be obtained directly by using the method described in this paper or by applying a factor of safety to the average test fatigue limit that simplifies the determination of an appropriate design S-N-P curve for the designer and structures engineer. A table is presented showing the factor of safety required to ensure a minimum desired probability and confidence level when only a limited number of test specimens is available.
Helicopter Fatigue Substantiation Procedures for Civil Aircraft
Authors: Dougherty J. E. , Spicer H. C.
Published: September 2009

This paper presents four aspects of the helicopter fatigue problem as viewed by the Federal Aviation Agency. They relate to: (1) development of the fatigue requirements for civil helicopters; (2) application of these fatigue requirements; (3) history of failures known to have been attributed to or influenced by fatigue; and (4) future prospects for new and improved means to cope with fatigue evaluation problems.
An Aluminum Sandwich Panel Fatigue Test Under Mach-2.4 Cruising Conditions
Authors: Buntin W. D. , Love T. S.
Published: September 2009

Progress has been made in recent years in studying the effects of aerodynamic heating, which is a relatively new factor that must be accounted for in designing and testing aircraft structures. A great deal of effort has been spent to develop analytical methods that include the effects of elevated temperature. Most such methods, applicable to full-scale structures, are approximations at best and make no accounting for strength degradation due to transient conditions that vary with time. Therefore testing that must include time-dependent cyclic loads as well as static loads for maximum conditions continues to be a primary tool of the structures engineer in evaluating structures designed for sustained supersonic flight.
Estimation of Fatigue Performance of Aircraft Structures
Authors: Schijve J.
Published: September 2009

The simulation of random service loads by cyclic loads is discussed. It is noted that their similarity can at present be shown on an empirical basis only. A few test programs are reviewed; a clear picture has not yet been obtained.

The results of program-fatigue tests on notched light alloy specimens and structures show that ∑N¯n values are on the average larger than 1; and macrocrack propagation in sheet material is slower than predicted by the Palmgren-Miner rule. In addition to the amount of microcracking, the second damage parameter of residual stress at the tip of the crack is of great importance. Both parameters allow a qualitative understanding of the deviations from the Palmgren-Miner rule.

The rule is a useful tool to make rough life estimates in the early design stage, but the major difficulty is to obtain relevant and accurate S-N data. The rule is found to be unreliable in judging whether a certain type of service loading would contribute substantially to the damage induced by other loads.

Full-scale testing is considered to be indispensable to establish the fatigue performance of a new aircraft design. With present-day experimental facilities, a simulation of the anticipated load-time history in service is advised for such a test. Since program-fatigue testing may be useful for design studies, recommendations are made for planning the load sequence in this type of test.
Microscopical Apparatus and Techniques for Observing the Fiber-Forming Process
Authors: Mogensen Allan O.
Published: September 2009

A glass cell is described which fits on a standard microscope stage and which permits observation of a single filament of fiber-forming material as it is extruded and coagulated in a liquid medium. As examples of the morphological studies possible, photomicrographs are shown of fiber breakage (by high-speed motion pictures), light-scattering in dark field, and orientation by polarized light.
Resinography with 8-A X-Rays
Authors: Newman Sanford B.
Published: September 2009

In order to emphasize the value of point-projection X-ray microscopy for resin research, examples of data obtainable with simple equipment are presented. These data were collected from opaque, porous, and fibrous structures.
Stress Crazing Failure—A Mechanism of Surface Formation Through Wetting
Authors: Coulehan R. E.
Published: September 2009

Many papers have recently appeared describing the failure of several polymers that were stressed in the presence of certain liquids. An examination into the mechanism causing this failure is made through birefringence high-speed photography and surface morphology after fracture.
Predicting Fatigue Crack Growth in the Residual Stress Field of a Cold Worked Hole
Authors: Kokaly Matthew T. , Ransom Joy S. , Restis Jude H. , Reid Len
Published: September 2009

Cold working of holes generates compressive residual stresses resulting in a significant fatigue life improvement over a non-cold worked hole. Current fatigue life prediction methods for cold worked holes are based on two-dimensional (2-D) linear superposition of stress intensity factor, K, solutions of the non-cold worked hole and the residual stresses. Such predictions have shown various levels of agreement with the overall fatigue life and have generally underpredicted the crack growth over the majority of life. An inverse process was used to generate K solutions for the residual stresses of two experimental data sets using AFGROW and the crack growth data from the experiments. The inverse K solutions were inconsistent with the residual stress distribution indicating that it contained mechanisms or features not inherent to the 2-D weight function method. The predicted fatigue life was found to be very sensitive to a ± 1 % variance in the inversely generated K solution. This sensitivity of the K method is a very important issue that must be addressed in the future. A 2-D FEA model indicated that the crack remained completely closed over a range of crack lengths despite experimental crack growth indicating that the model was not an accurate physical representation of the real crack. The results of this study combined with the significantly faster crack growth observed on the side of the hole corresponding to the entry side of the mandrel and the through thickness residual hoop stress variation show that the current methodology based on a 2-D assumptions is inadequate in predicting the fatigue crack growth from cold worked holes for the range of specimen thicknesses in this study. It is suggested that further research focus on incorporating the through thickness stress variance in a solution that predicts crack growth both in the radial and through thickness directions to capture the peculiar crack growth associated with cold working.
Novel Applications of the Deep-Hole Drilling Technique for Measuring Through-Thickness Residual Stress Distributions
Authors: Kingston Edward J. , Stefanescu Danut , Mahmoudi Amir H. , Truman Chris E. , Smith David J.
Published: September 2009

This paper presents novel applications of the deep-hole drilling technique for residual stress measurement in components. The results outline the versatility of this technique for application in complex situations such as residual stress measurement in very thick components, components with difficult access to the measurement location, very large components, components requiring high spatial resolution, and components requiring detailed near surface residual stress distribution. The deep-hole drilling measurements were compared with results obtained using other measurement techniques. Excellent agreement was found between the results.
Investigation of Masonry Failure of a Granite and Limestone Clad Historic Church in Eastern Pennsylvania
Authors: Erdly Jeffrey L. , Valentino Erik R.
Published: September 2009

The use of dimension stone was commonplace in turn of the century churches and St. George's in Shenandoah, PA, is an example of granite and limestone construction set in the anthracite belt of Eastern Pennsylvania. The structure's two towers, over 100 feet tall, have recently succumbed to age, the elements, and poor long-term repairs and maintenance that veiled shifting limestone and granite. Early detection did not occur due to the lack of periodic inspection following ASTM's Standard E 2270 “Standard Practice for Periodic Inspection of Building Facades for Unsafe Conditions,” and the oldest Lithuanian Catholic Church in the United States has temporarily closed. Field observations have revealed a variety of failures. Limestone and the front entrance has outwardly displaced from the mass masonry brick backup nearly 1 in. at several locations. Granite masonry at the top of the towers has outwardly displaced 3/4 in. and has caused adjacent decorative limestone elements to displace up to 2 in. away from the wall. Spalled fragments of limestone of different sizes have fallen to the ground from varying heights at the rate of nearly one piece per month during recent years. A condition assessment examining the masonry deficiencies has been completed and the building now faces substantial repair options that may impact the building's operational viability.
A Statistical Interpretation of the Effect of Understressing on Fatigue Strength
Authors: Epremian E. , Mehl R. F.
Published: September 2009

It has generally been accepted for many years that understressing has a beneficial effect on the fatigue properties of metals. Further, it has been thought that this improvement is the result of a mild cold-working effect produced by the cyclic stressing at or below the endurance limit of the material. This conclusion is based on the observation that previously under-stressed specimens will undergo a larger number of cycles to failure relative to the virgin life at some higher stress in the fracture range.

Unquestionably cold-work can have a beneficial effect on the fatigue properties; drawing and shot-peening produce marked improvements. Metallographic as well as other investigations have shown that deformation and cold-work are produced in the fatigue process. None of the previous studies on the understressing effect have, however, been made from the necessary statistical approach. It is now well established that both the fatigue life and endurance limit are statistical quantities. Lack of recognition of this fact can lead to misinterpretation of the data and erroneous conclusions.

The purpose of this investigation was to study the understressing effect from a statistical viewpoint. The experimental work was an extension of the research reported in a companion paper 4 and is being published separately to give it proper emphasis. It will be shown that the understressing effect can, in part if not wholly, be interpreted as a phenomenon based on selectivity and the statistical nature of the endurance limit; and that cold-work does not play a dominant role in this behavior.
Fatigue Properties of Large Specimens with Related Size and Statistical Effects
Authors: Horger Oscar J. , Neifert Harry R.
Published: September 2009

This paper summarizes the results of rotating-bending fatigue tests on shafts 0.3- to 6-in. diameter from SAE plain carbon steels of 0.39 and 0.54 per cent carbon content in both the “as-forged” and normalized-and-tempered conditions. Shafts were tested with stress concentration, as represented by both fillets and press-fitted members, as well as plain specimens.

Shafts with stress concentration produced by fillets or press-fitted members from either untreated or normalized-and-tempered steels exhibited little or no size effect. An endurance limit ranging from 17,500 to 25,000 psi was found from tests on 101 plain specimens of 6-in. diameter untreated steel, while filleted shafts (r/d = 0.14 and 0.29) of the same material had endurance limit values within this range. A similar comparison exists on normalized-and-tempered steel, but here less extensive data are available.

Some effect of size was indicated on plain specimens 6 in. in diameter, which had a minimum endurance limit 35 per cent lower than that found for the conventional 0.3-in. diameter plain specimens from untreated steel. Data are reported on various groups of small specimens machined from large forgings and 22 in. bar stock.
The Feasibility of Using a Risk-informed Approach for Calculating Reactor Pressure Vessel Heatup and Cooldown Operating Curves
Authors: Gamble Ron , Server William , Carter Robert
Published: September 2009

The current procedures for calculating pressure-temperature (P/T) limits for normal reactor startup and shutdown are defined by deterministic fracture mechanics methodology in the ASME Code, Appendix G (in both Section XI and Section III). The recent pressurized thermal shock (PTS) re-evaluation effort used a very thorough probabilistic fracture mechanics (PFM) evaluation to develop a technical basis to increase the PTS screening criteria. The feasibility of applying this same PFM methodology to evaluate normal startup and shutdown operation for both pressurized water reactor (PWR) and boiling water reactor (BWR) pressure vessels is described in this paper. The approach taken in this study was to define a new risk-informed margin term to be applied to the stress intensity factor for membrane tension (KIm) in Appendix G. The margin on KIm was determined by finding the value that results in a vessel failure frequency equal to 10−6 failures/reactor-year when the reactor operates up to the pressure-temperature limits calculated using the risk-informed margin. This simple approach was selected because it results in a minimum change to the current ASME Code procedure, is easy to apply when revising plant operating P/T limits, and allows for an increase in the allowable P/T limits by as much as would be provided by any alternate procedure. The results from this initial study indicate the margin on KIm in Appendix G can be reduced from 2 to 1.5 for PWR vessels for shutdown and potentially reduced from 2 to as low as 1 for startup. The results indicate the margin on KIm in Appendix G can be reduced from 2 to approximately 1 for BWR vessels for shutdown and potentially startup. Additional analyses for PWR and BWR vessels will be needed to develop a comprehensive risk-informed basis for any revisions to the ASME Code, Appendix G.
Analysis of the Ductile-to-Brittle Transition Temperature Shift in a Commercial Power Plant With High Nickel Containing Weld Material
Authors: Efsing Pål , Jansson Christer , Mager Tom , Embring Göran
Published: September 2009

Plant specific surveillance programs that ideally include all relevant materials and materials combinations that are subjected to neutron irradiation during operation address the degradation due to irradiation of the reactor pressure vessel material for nuclear electric power plants. Plant specific surveillance programs are not unique to the two power plants treated in this study. The current Swedish regulatory system does, however, call for a fairly rigid approach within the surveillance program. In the Swedish case, this means that there is a plant specific predetermined inspection/test program that has to be followed in order to verify the operability of the power plant and also to verify the operational limits with respect to pressure/temperature effects on a repetitive basis. The two pressurized water reactor plants Ringhals 3 and 4 have in common that the weld metal used for the butt welds of the reactor pressure vessel is a high nickel type material, above the current limits of the NUREG Reg. Guide 1.99, rev. 2. In the original state, the high nickel content provides excellent fracture toughness in the unirradiated material condition and a low ductile-to-brittle transformation temperature (DBTT). It has, however, been highlighted in several studies that high nickel materials exhibit a very large DBTT shift as a consequence of irradiation, and also that the precipitates that form during the irradiation are not as easily controlled during a heat treatment to remove the irradiation damage as are the copper rich clusters. This paper will present the current state of the art regarding these effects as observed in the weld metal specimens. The paper will present the results from the Charpy V notched and fracture mechanics specimen test encapsulated in the Ringhals Units 3 and 4 surveillance programs. The results from the Ringhals Units 3 and 4 surveillance programs show that there is a need for corrective action to be taken in order to ensure 60 y of operability for the two power plants.
Information Fusion Embrittlement Models for U.S. Power Reactor Pressure Vessel Steels
Authors: Wang J. A. , Rao N. S. V. , Konduri S.
Published: September 2009

A new approach of utilizing information fusion technique is developed to predict the radiation embrittlement of reactor pressure vessel steels. The Charpy transition temperature shift data contained in the Power Reactor Embrittlement Database is used in this study. Six parameters—Cu, Ni, P, neutron fluence, irradiation time, and irradiation temperature—are used in the embrittlement prediction models. The results indicate that this new embrittlement predictor achieved reductions of about 49.5 % and 52 % in the uncertainties for plate and weld data, respectively, for pressurized water reactor and boiling water reactor data, compared with the Nuclear Regulatory Commission Regulatory Guide 1.99, Rev. 2. The implications of dose-rate effect and irradiation temperature effects for the development of radiation embrittlement models are also discussed.
Internal Probe to Detect Defects from Cascades—In-situ Ion Irradiation Experiments Revisited
Authors: Ishino Shiori , Sekimura Naoto , Abe Hiroaki
Published: September 2009

Our understanding of the evolution of extended defects during irradiation has progressed considerably since 1990 following the proposal of production bias by Bachu Singh and C. H. Woo. One of the important phenomena underlying this concept is that self-interstitials and interstitial clusters can migrate a long distance via one-dimensional motion. There have been a number of indirect experimental evidences supporting this mode of migration. However, the direct evidence has not necessarily been sufficient. In this paper, we revisit our former experimental results of in-situ observation of ion irradiation damage from the stand point of an internal probe for detecting point defect fluxes in an irradiation environment or those coming from nearby cascades. Surfaces, giving rise to specimen size effects, preexisting dislocations, intentionally preintroduced vacancy loops with stacking fault, irradiation induced vacancy clusters and loops, precipitates and precipitate-matrix interfaces, etc., are utilized to monitor the influx of point defects, particularly those of interstitials nature. Some of the reanalysis of the former results will be presented.
Late-night and low-dose dexamethasone-suppressed cortisol in saliva and serum for the diagnosis of cortisol-secreting adrenal adenomas
Authors: Deutschbein Timo , Unger Nicole , Hinrichs Jakob , Walz Martin K , Mann Klaus , Petersenn Stephan
Published: September 2009

Objective

In patients with adrenal incidentalomas, hormonally active masses need to be considered, particularly cortisol-producing adenomas (CPA), aldosterone-producing adenomas, and pheochromocytomas. The screening for hypercortisolism relies on confirming excess cortisol secretion and insufficient suppression after dexamethasone. Because of its high correlation with free cortisol and its stress-free collection, salivary cortisol (SaC) may offer advantages over serum cortisol (SeC). We evaluated the value of SaC and SeC for the diagnosis of CPA.

Design

Comparative study between 2001 and 2006.

Methods

Thirty-eight patients with confirmed CPA were compared with 18 healthy subjects as well as 48 control patients suffering from aldosterone-producing adenomas (n=13), pheochromocytomas (n=16), or nonfunctioning adenomas (n=19). Sampling of saliva and serum was performed at 2300 and at 0800 h following low-dose dexamethasone suppression. Receiver operating characteristics analysis was used to calculate thresholds with at least 95% sensitivity for CPA.

Results

Regarding the cutoffs for late-night cortisol, SaC (4.8 nmol/l, sensitivity 97%, specificity 69%) was slightly more specific than SeC (115 nmol/l, sensitivity 97%, specificity 63%). In contrast, the cutoff for dexamethasone-suppressed SaC (3.7 nmol/l, sensitivity 97%, specificity 83%) was slightly less specific than SeC (94 nmol/l, sensitivity 97%, specificity 88%). However, the latter cutoffs demonstrated greater specificity when compared with the cutoffs for late-night cortisol.

Conclusion

The diagnostic accuracy of SaC is as good as SeC. Owing to its higher specificity, dexamethasone-suppressed cortisol is preferable to late-night cortisol when screening for Cushing's syndrome in patients with adrenal incidentalomas.
Weed Management in Glyphosate- and Glufosinate-Resistant Sugar Beet
Authors: Kemp Nathan J. , Taylor Erin C. , Renner Karen A.
Published: September 2009

Field experiments were conducted to determine the critical period of weed interference in glyphosate- and glufosinate-resistant sugar beet, and to determine if PRE herbicides increased weed control or sugar beet root yield when glufosinate, glyphosate, or conventional POST herbicides were applied. Glyphosate- and glufosinate-resistant sugar beet root yields were reduced by up to 66 and 67%, respectively, when weeds remained all season in the weedy control treatment compared with yields when weed removal occurred as soon as the weeds were 2.5 cm tall, approximately 2 to 3 wk after planting (WAP). A critical period of weed interference did not occur in this research. The critical time of weed removal was approximately 8 WAP in 1998 and beyond 11 WAP in 1999. Weeds averaged 20 cm in height at 8 WAP and weed densities were greater in 1998 compared with 1999. The critical weed-free period for glyphosate- and glufosinate-resistant sugar beet was 4.5 to 5 WAP in 1998. In 1999, the critical weed-free period at the Michigan Sugar location was 1.5 WAP in glyphosate-resistant sugar beet, and 6.5 WAP in glufosinate-resistant sugar beet for the Michigan Sugar site. Glyphosate or glufosinate POST provided better weed control and resulted in greater sugar beet root yield compared with conventional POST herbicides when data were combined over PRE herbicide treatments. PRE herbicides improved the control of common lambsquarters andAmaranthusspecies in some of the site-years when data were combined over POST treatments, but sugar beet yield did not increase. Our research suggests that PRE herbicides will not be necessary in glyphosate- or glufosinate-resistant sugar beet. To avoid sugar beet yield loss, multiple POST applications of glyphosate or glufosinate will be needed until 6 to 9 WAP to prohibit yield loss from weeds emerging after the last POST application.
Multiple Season Reductions in Herbicide, Downy Brome (Bromus tectorum), and Irrigation in Corn
Authors: Currie Randall S. , Klocke Norman L. , Davis Holly N. , Buschman Lawrent L.
Published: September 2009

This research explored the use of downy brome (BROTE) as a cover crop in irrigated corn. Although BROTE is a difficult weed to control, it could not be maintained as a cover crop in no-till irrigated corn for more than one season. A 10-fold reduction in BROTE occurred in the second year of corn. By the fourth year, only one BROTE plant could be found at the two locations. Because BROTE did not persist across years, soil coverage decreased 5 to 18% in the later location-years. At one location, normal herbicide rates decreased Johnsongrass biomass more than 22-fold both years it was applied. Increasing herbicide input decreased Palmer amaranth density more than 3-fold, but only in a single location-year. In three of six location-years, level of herbicide input had no significant effect on evapotranspiration (ET). Increased BROTE biomass decreased ET 0.033 to 0.083 cm/d during the first season at both locations. Increased irrigation increased corn yield by 240 to 1,900 kg/ha in five of six location-year combinations. Half rates of in-season herbicides reduced yield only in one of six location-years. High BROTE density reduced ET but did not translate into increased crop yield. In three of six location-year combinations, high BROTE density decreased yield by 300 to 1,000 kg/ha. In a single location-year, increased surface residues provided by BROTE increased yield by 560 kg/ha. Increased irrigation inputs decreased water use efficiency (WUE) by 6.3 kg/ha-cm in a single location-year and increased WUE by 10.8 to 121.6 kg/ha-cm in four of six location-years. Increased herbicide inputs increased WUE by 10.3 kg/ha-cm in one location-year. BROTE density had no significant effect on WUE at location 1. At location 2 in the first 2 yr, WUE was increased 9.4 to 22.2 kg/ha-cm.
Weed Response to Flame Weeding at Different Developmental Stages
Authors: Sivesind Evan C. , Leblanc Maryse L. , Cloutier Daniel C. , Seguin Philippe , Stewart Katrine A.
Published: September 2009

Flame weeding is often used for weed control in organic production and other situations where use of herbicides is prohibited or undesirable. Response to cross-flaming was evaluated on five common weed species: common lambsquarters, redroot pigweed, shepherd's-purse, barnyardgrass, and yellow foxtail. Dose-response curves were generated according to species and growth stage. Dicot species were more effectively controlled than monocot species. Common lambsquarters was susceptible to flame treatment with doses required for 95% control (LD95) ranging from 0.9 to 3.3 kg/km with increasing maturity stage. Comparable levels of control in redroot pigweed required higher doses than common lambsquarters, but adequate control was still achieved. Flaming effectively controlled shepherd's-purse at the cotyledon stage (LD95 = 1.2 kg/km). However, the LD95 for weeds with two to five leaves increased to 2.5 kg/km, likely due to the rosette stage of growth, which allowed treated weeds to avoid thermal injury. Control of barnyardgrass and yellow foxtail was poor, with weed survival > 50% for all maturity stages and flaming doses tested. Flame weeding can be an effective and labor-saving weed control method, the extent of which is partially dependent on the weed flora present. Knowledge of the local weed flora and their susceptibility to flame weeding is vital for the effective use of this method.
Evaluation of Spring and Fall Burndown Application Timings on Control of Glyphosate-Resistant Horseweed (Conyza canadensis) in No-Till Cotton
Authors: Owen Lucas N. , Steckel Lawrence E. , Koger Cliford H. , Main Christopher L. , Mueller Thomas C.
Published: September 2009

Field studies were conducted in 2007 and 2008 to evaluate fall applications of herbicides to control glyphosate-resistant (GR) horseweed before planting cotton. Fall treatments were compared with spring treatments for control of GR horseweed and effect on seed cotton yield. Fall and spring treatments with and without residual herbicides were also compared. No differences were observed for control of GR horseweed or seed cotton yield between fall and spring application timings. However, a difference was observed between fall applications with and without a residual herbicide. Fall applications that contained residual herbicides provided 86% control of GR horseweed and yielded 2,360 kg/ha of seed cotton. Fall applications that did not contain a residual herbicide only provided 70% control of GR horseweed and yielded 2,010 kg/ha of seed cotton. No benefit was observed from spring applications that contained a residual herbicide. This research indicates that glyphosate-resistant horseweed can be controlled with fall- or spring-applied burndown herbicides, and fall applications should include a residual herbicide for best results.
Identification of a Johnsongrass (Sorghum halepense) Biotype Resistant to ACCase-Inhibiting Herbicides in Northern Greece
Authors: Kaloumenos Nikolaos S. , Eleftherohorinos Ilias G.
Published: September 2009

A johnsongrass population from a cotton field in northern Greece along with a population from the university farm (“Control”) were evaluated for resistance to the herbicide quizalofop; cross-resistance to cycloxydim, propaquizafop, and fluazifop (acetyl coenzyme A [CoA] carboxylase [ACCase]-inhibiting herbicides), and multiple resistance to nicosulfuron (acetolactate synthase [ALS]-inhibiting herbicides). In greenhouse experiments, the application of four times the recommended rates of quizalofop and propaquizafop to suspected resistant rhizomatous plants resulted in 4 and 5% growth reduction, respectively. However, the growth of suspected resistant seedlings was reduced by 54 and 28% after the application of two times the recommended rate of the same herbicides. In contrast, the application of quizalofop and propaquizafop at recommended rates on rhizomatous plants and seedlings of the Control population reduced their growth by 97 to 100%. Also, the growth reduction of both populations by the application of cycloxydim, fluazifop, and nicosulfuron at recommended rates ranged from 93 to 100%. In the field experiment, quizalofop and propaquizafop applied at four times the recommended rate reduced growth of the suspected resistant population by 9 and 18%, respectively, whereas the recommended rate of fluazifop gave a 94% growth reduction of this weed. The herbicide rate required for 50% growth reduction (GR50) values for rhizomatous plants of the suspected resistant population were 0.90 and 2.465 kg ai/ha for quizalofop and propaquizafop, respectively, whereas the correspondingGR50values for the seedlings were 0.074 and 0.185 kg ai/ha. These results indicate that a johnsongrass population developed cross-resistance to quizalofop and propaquizafop, but did not evolve cross-resistance to cycloxydim and fluazifop or multiple resistance to nicosulfuron.
Creeping Bentgrass (Agrostis stolonifera) Putting Green Tolerance to Bispyribac-Sodium
Authors: McCullough Patrick E. , Hart Stephen E.
Published: September 2009

Bispyribac-sodium is an efficacious herbicide for annual bluegrass control in creeping bentgrass fairways, but turf tolerance and growth inhibition may be exacerbated by low mowing heights on putting greens. We conducted field and greenhouse experiments to investigate creeping bentgrass putting green tolerance to bispyribac-sodium. In greenhouse experiments, creeping bentgrass discoloration from bispyribac-sodium was exacerbated by reductions in mowing height from 24 to 3 mm, but mowing height did not influence clipping yields or root weight. In field experiments, discoloration of creeping bentgrass putting greens was greatest from applications of 37 g/ha every 10 d, compared to 74, 111, or 222 g/ha applied less frequently. Chelated iron effectively reduced discoloration of creeping bentgrass putting greens from bispyribac-sodium while trinexapac-ethyl inconsistently reduced these effects. Overall, creeping bentgrass putting greens appear more sensitive to bispyribac-sodium than higher mowed turf, but chelated iron and trinexapac-ethyl could reduce discoloration.
Selecting for Weed Resistance: Herbicide Rotation and Mixture
Authors: Beckie Hugh J. , Reboud Xavier
Published: September 2009

Herbicide rotations and mixtures are widely recommended to manage herbicide resistance. However, little research has quantified how these practices actually affect the selection of herbicide resistance in weeds. A 4-yr experiment was conducted in western Canada from 2004 to 2007 to examine the impact of herbicide rotation and mixture in selecting for acetolactate synthase (ALS) inhibitor resistance in the annual broadleaf weed, field pennycress, co-occurring in wheat. Treatments consisted of the ALS-inhibitor herbicide, ethametsulfuron, applied in a mixture with bromoxynil/MCPA formulated herbicide (photosystem-II inhibitor/synthetic auxin), or in rotation with the non-ALS inhibitor at an ALS-inhibitor application frequency of 0, 25, 50, 75, and 100% (i.e., zero to four applications, respectively) over the 4-yr period. The field pennycress seed bank at the start of the experiment contained 5% ethametsulfuron-resistant seed. Although weed control was only marginally reduced, resistance frequency of progeny of survivors increased markedly after one ALS-inhibitor application. At the end of the experiment, the level of resistance in the seed bank was buffered by susceptible seed, increasing from 29% of recruited seedlings after one application to 85% after four applications of the ALS inhibitor. The level of resistance in the seed bank for the mixture treatment after 4 yr remained similar to that of the nontreated (weedy) control or 0% ALS-inhibitor rotation frequency treatment. The results of this study demonstrate how rapidly ALS-inhibitor resistance can evolve as a consequence of repeated application of herbicides with this site of action, and supports epidemiological information from farmer questionnaire surveys and modeling simulations that mixtures are more effective than rotations in mitigating resistance evolution through herbicide selection.
Weed Growth and Efficacy of PRE-Applied Herbicides in Alternative Rooting Substrates Used in Container-Grown Nursery Crops
Authors: Wehtje Glenn , Altland James E. , Gilliam Charles H. , Marble Stephen C. , Van Hoogmoed Albert J. , Fain Glenn B.
Published: September 2009

Container-grown nursery crops in the southeastern United States are typically grown in a rooting substrate comprised primarily of the ground bark of pine trees. However, pine bark is becoming less available and more costly because of changes in production and marketing practices within southeastern pine forestry. This shortage has resulted in the economic incentive to seek pine bark alternatives. Two possible alternatives are clean chip residual and whole tree. These alternatives are like pine bark, because both are products of southern pine forestry. Unlike pine bark, which is a single part of the tree, these alternatives contain all parts of the tree, including wood and foliage in various portions. Registration of preemergence-active herbicides has been based solely upon data obtained from pine bark–based nursery production. Research was conducted to determine if the control of (1) large crabgrass with prodiamine, (2) eclipta with flumioxazin, and (3) spotted spurge with isoxaben would be comparable in these alternatives to what has been established in pine bark. Seed germination of all three weed species in no-herbicide controls was approximately 10% and equivalent between pine bark and the alternatives. Foliage fresh weight production of large crabgrass and spotted spurge was less in the alternatives compared to pine bark; eclipta was not affected. For all three weed species–herbicide combinations, weed control was nearly identical between pine bark and the alternative substrates, provided the herbicide had been applied at its registered rate. For all three herbicides, rates that are effective in pine bark substrates will be equally effective in the pine bark alternatives.
Sequential Applications for Mesosulfuron and Nitrogen Needed in Wheat
Authors: Sosnoskie Lynn M. , Culpepper A. Stanley , York Alan C. , Beam Josh B. , MacRae Andrew W.
Published: September 2009

Mesosulfuron is often applied to wheat at a time of year when top-dress nitrogen is also applied. Current labeling for mesosulfuron cautions against applying nitrogen within 14 d of herbicide application. Soft red winter wheat response to mesosulfuron and urea ammonium nitrate (UAN) applied sequentially and in mixtures was determined at three locations in North Carolina and Georgia during 2005 and 2006. Mesosulfuron at 0, 15, and 30 g ai/ha was applied in water to wheat at Feekes growth stage (GS) 3 followed by UAN at 280 L/ha 2 h, 7 d, 14 d, and 21 d after mesosulfuron. Mesosulfuron applied in UAN was also evaluated in 2006. Mesosulfuron injured wheat 6 to 9% in 2005 and 12 to 23% in 2006 when UAN was applied 2 h or 7 d after the herbicide. Wheat injury did not exceed 8% when UAN was applied 14 or 21 d after the herbicide. Greatest injury, 35 to 40%, was noted when mesosulfuron and UAN were combined. Wheat yield was unaffected by mesosulfuron or time of UAN application in 2005. In 2006, yield was affected by the timing of UAN application relative to mesosulfuron; wheat yield increased as the interval, in days, between UAN and herbicide applications increased. To avoid crop injury and possible yield reduction, mesosulfuron and UAN applications should be separated by at least 7 to 14 d. These findings are consistent with precautions on the mesosulfuron label.
Response of Three Annual Medic Species to Postemergence Herbicides
Authors: Grichar W. James , Ocumpaugh W. R.
Published: September 2009

Field studies were conducted from 2004 to 2006 to evaluate the tolerance of three annual medic species (bur, black, and barrel medic) to selected POST herbicides. 2,4-DB at 0.56 and 1.12 kg/ha caused the most stunting across all three species. Imazethapyr at 0.1 kg/ha stunted all three annual medics in 1 of 3 yr whereas flumetsulam at 0.04 kg/ha stunted black and barrel medics in 1 of 3 yr. Clethodim at 0.28 kg/ha did not cause any medic stunting. Imazethapyr, imazamox, and 2,4-DB at 0.56 kg/ha reduced henbit dry matter composition compared to the untreated check whereas clethodim, flumetsulam, and 2,4-DB at 1.12 kg/ha did not. In 2004, 2,4-DB at 1.12 kg/ha reduced dry weight yield of bur and barrel medic but not black medic when compared with the untreated check. Black medic treated with imazethapyr at 0.05 and 0.1 kg/ha and clethodim at 0.28 kg/ha produced higher dry weight yield than the untreated check. In 2006, both rates of 2,4-DB and flumetsulam at 0.04 kg/ha reduced dry weight yield of bur medic compared to the untreated check. Barrel medic dry weight yields were reduced by both rates of 2,4-DB and flumetsulam compared to untreated check. No herbicides reduced dry weight yields of black medic.
Vaccines for the Treatment of Non-Small Cell Lung Cancer: A Renewed Anticancer Strategy
Authors: Gridelli Cesare , Rossi Antonio , Maione Paolo , Ferrara Marianna Luciana , Castaldo Vincenzo , Sacco Paola Claudia
Published: September 2009

Carcinoma of the lung is the leading cause of cancer death worldwide, with non-small cell lung cancer (NSCLC) constituting about 85% of all new diagnoses. Standard approaches for each NSCLC stage have reached a plateau in effectiveness. A variety of novel approaches are now being investigated to improve the outcome of this disease. Despite decades of research, no specific active cancer vaccine has, to date, been approved for NSCLC therapy; nevertheless, vaccine therapy has recently re-emerged as a potential therapeutic approach. In particular, several new paradigms have stemmed from recent clinical findings both in the use of combination therapy approaches with more sophisticated specific vaccines and in clinical trial design and endpoint analyses. Several vaccine therapies have been investigated in NSCLC, including in the early and advanced disease stages. The best results appear to be in the adjuvant settings and in locally advanced NSCLC. In fact, in these two settings, phase III randomized trials are ongoing evaluating the melanoma-associated antigen A3 vaccine and the liposomal BLP25 vaccine. This paper reviews the main clinical trials involving several different cancer vaccines employed in the treatment of early and advanced stage NSCLC, focusing on those in advanced stages of development.
Prognostic Significance of Epidermal Growth Factor Receptor Phosphorylation and Mutation in Head and Neck Squamous Cell Carcinoma
Authors: Hama Takanori , Yuza Yuki , Saito Yoshimichi , O-uchi Jin , Kondo Shu , Okabe Masataka , Yamada Hisashi , Kato Takakuni , Moriyama Hiroshi , Kurihara Satoshi , Urashima Mitsuyoshi
Published: September 2009

The molecular status of the epidermal growth factor receptor (EGFR) has not been as well studied in head and neck squamous cell carcinoma (HNSCC) as in lung cancer. We examined the frequencies of EGFR mutations as well as the expression/phosphorylation status of the EGFR protein in HNSCC patients. Moreover, we tried to elucidate associations between EGFR molecular status and patient characteristics and disease-free survival. In this prospective cohort study, clinical data and samples were obtained from 82 consecutive patients who had not been treated with EGFR molecular targeting therapy. Full-length EGFR was sequenced, and expression and phosphorylation of the EGFR protein were measured by Western blotting. Four novel mutations (E709K, V765G, Ins770G, and G1022S) and one mutation well-known in lung cancer (L858R) were identified in six HNSCC samples (7%), but we could not find any mutations in the extracellular domain of EGFR, such as EGFRvIII, in this study. E709K and Ins770G as well as L858R appear to be functional mutations based on the use of Ba/F3 cells. In terms of patient characteristics, the number of metastatic lymph nodes and node stage were associated with phosphorylation of EGFR. No patients with EGFR mutations relapsed during the study period. Excluding mutated cases, patients whose tumor samples showed phosphorylated EGFR relapsed significantly earlier than those without phosphorylated EGFR. This finding was still significant after adjusting for mutation and overexpression of EGFR protein using the Cox proportional hazard model. In conclusion, phosphorylated EGFR without mutations may be a marker of poor prognosis in patients with HNSCC.
Clinical Outcomes Associated with Bevacizumab-Containing Treatment of Metastatic Colorectal Cancer: The BRiTE Observational Cohort Study
Authors: Kozloff Mark , Yood Marianne Ulcickas , Berlin Jordan , Flynn Patrick J. , Kabbinavar Fairooz F. , Purdie David M. , Ashby Mark A. , Dong Wei , Sugrue Mary M. , Grothey Axel ,   for the investigators of the BRiTE study
Published: September 2009

Background.

The Bevacizumab Regimens’ Investigation of Treatment Effects (BRiTE) study is a prospective, observational cohort study designed to elucidate safety and effectiveness outcomes associated with bevacizumab combined with chemotherapy as used in clinical practice for first-line treatment of metastatic colorectal cancer (mCRC).

Patients and Methods.

Baseline characteristics, prespecified bevacizumab-related adverse events, and effectiveness data were collected from 1,953 mCRC patients who were receiving first-line treatment including bevacizumab at 248 U.S. sites.

Results.

At database lock, the median follow-up was 20.1 months. At baseline, 46% of patients were aged ≥65 years and 49% had an Eastern Cooperative Oncology Group performance status score ≥1. Fluorouracil, leucovorin, and oxaliplatin was the most common first-line chemotherapy regimen (56%). Overall rates of bevacizumab-related adverse events in the BRiTE study, such as gastrointestinal perforation (1.9%), arterial thromboembolic events (2%), grade 3–4 bleeding (2.2%), and de novo hypertension requiring medication (22%), were consistent with those reported in randomized clinical trials (RCTs) of bevacizumab in first-line mCRC treatment. The median progression-free survival (PFS) and overall survival (OS) times were 9.9 (95% confidence interval [CI], 9.5–10.3) months and 22.9 (95% CI, 21.9–24.4) months, respectively.

Conclusion.

The median PFS and OS durations and safety profile of bevacizumab in the BRiTE study were similar to those in RCTs of bevacizumab plus chemotherapy in first-line mCRC patients. The observations from the BRiTE study complement and expand upon RCT data, providing clinical information in a large cohort of bevacizumab-treated patients and subgroups such as the elderly.
Phase III trial of chemotherapy using 5-fluorouracil and streptozotocin compared with interferon α for advanced carcinoid tumors: FNCLCC–FFCD 9710
Authors: Dahan Laetitia , Bonnetain Frank , Rougier Philippe , Raoul Jean-Luc , Gamelin Eric , Etienne Pierre-Luc , Cadiot Guillaume , Mitry Emmanuel , Smith Denis , Cvitkovic Frédérique , Coudert Bruno , Ricard Floriane , Bedenne Laurent , Seitz Jean-François , _ _
Published: September 2009

The aim of this randomized multicenter phase III trial was to compare chemotherapy and interferon (IFN) in patients with metastatic carcinoid tumors. Patients with documented progressive, unresectable, metastatic carcinoid tumors were randomized between 5-fluorouracil plus streptozotocin (day 1–5) and recombinant IFN-α-2a (3 MU×3 per week). Primary endpoint was progression-free survival (PFS). From February 1998 to June 2004, 64 patients were included. The two arms were well matched for median age, sex ratio, PS 0–1, previous chemotherapy, surgery, or radiotherapy. The median PFS for chemotherapy was 5.5 months versus 14.1 for IFN (hazard ratio=0.75 (0.41–1.36)). Overall survival (OS), tolerance, and effects on carcinoid symptoms were not significantly different. Despite a trend in favor of IFN, there was no difference in PFS and OS in advanced metastatic carcinoid tumors and therapeutic effect of both treatments was mild.
Application of an Innovative Conveyance Risk Management Methodology for Long or Tortuous Wells
Authors: Castillo H. C. , Wills P.
Published: September 2009

Some of the most important aspects to consider during the design, construction, and productive life of a well are the amount and nature of the risks associated with the conveyance of downhole instruments to acquire critical formation-evaluation data while the hole is open and downhole-tool strings needed to service the well after installing the completion and production hardware.

With the increase in popularity of long, deep, and tortuous wells, mainly in the high-cost operating environments, these risks have become more acute.

A new methodology, based on forces modeling and best practices gathered over decades, has been developed to take full advantage of new conveyance technologies intended to alleviate or eliminate these risks.

This paper describes the new conveyance risk-reduction technologies and their areas of applications, the newly developed risk management methodology, and the economical value these innovations bring to our industry.

To demonstrate the merits and practical aspects of such an enterprise, we discuss a case study in which a perforating job was successfully completed using wireline and downhole tractors in a highly deviated well that was planned using the new methodology.