bluuebunny/crossref_metadata_2025 huggingface dataset:
Low Temperature Properties of Elastomers
Authors: Liska John W.
Published: July 2009

Up to the time of the beginning of the recent World War, comparatively little was known about the low-temperature characteristics of rubber, in spite of the fact that a number of investigators (1–16) had studied the subject. This can be at least partly explained by the fact that natural rubber, the only important elastomer known at that time, retained its flexibility over a rather wide range of temperatures extending down to -70 F. or even lower. Applications requiring flexibility or elasticity at temperatures lower than -70 or -75 F. were relatively rare, and, as a result, much of the work on this subject was largely academic in nature. Two important factors quickly changed the emphasis from academic to highly practical considerations. First of all, aircraft ceilings were being continually raised, making it necessary for tires, airplane de-icers, engine mountings, and tubing to withstand lower and lower temperatures. Secondly, it was soon discovered that the synthetic rubbers which had to be substituted for natural rubber, without exception, became inflexible or even brittle at temperatures considerably higher than natural rubber. Other factors also contributed to the demand for knowledge of the behavior of elastomers at low temperatures. Tanks and trucks had to operate efficiently in the arctic as well as in the tropic regions. Airplanes, tanks, and ships carried more and more sensitive equipment for communication and direction of gunfire, all of which had to be mounted on vibration-absorbing supports in order to retain their accuracy during actual operations. Then too, in order to decrease transmission of vibration and shock as much as possible, rubber-like materials were used more and more as prime mounts for vehicles, that is, in the form of tank treads, tires, and bogie rollers on tanks. The majority of tests developed in recent years (17–26) to measure low-temperature serviceability, fall roughly into two classes: one, a method for determining the so-called brittle-point temperature; and, two means for measuring the rate of stiffening or hardening with decrease in temperature. Some atempts have also been made to measure physical properties under dynamic conditions at low temperatures (24), but so far these methods have not been developed very completely nor have they received any general acceptance. For these reasons, they will not be discussed in any detail in this paper, though their importance, when more fully developed, should not be minimized.
Possible Future Military Engine Oils for Ground Equipment
Authors: Klein N. L.
Published: July 2009

There has been considerable speculation during the past year concerning revision of U. S. Army Specification 2-104B. The need for revision has been recognized by all those who are familiar with the progress of the qualification program under the provisions of the specification.
Introduction
Authors: Linn F. C.
Published: July 2009

It is fitting, from time to time, for a group to review the progress it has made and to consider problems for the future. This was done by the authors of the four papers on different phases of turbine lubrication presented at the symposium. The authors are agreed that inhibited turbine oils have, in general, given a good account of themselves and are allowing the operation of turbines for extended periods of time with clean lubricating systems. Mr. Vivian Estcourt points out that not all inhibited oils have the same good qualities and that there is a need for better selection of inhibited turbine oils. He also makes a strong plea for the development of a laboratory test to better determine the remaining useful life of a used inhibited turbine oil.
Forming Parameters and Criteria for Design and Production
Authors: Schroeder William
Published: July 2009

Forming parameters and criteria are discussed with reference to design and production problems. The results of some of the most significant studiesare reviewed briefly. The following specific subjects are discussed: Generalized stress and strain; dimensional similarity; laws of fracture; classification of formed sheet metal parts; basic types of forming action, including stretching, bending and drawing; and the significant parameters and criteria for these three types of forming. Where these parameters and criteria are known to have limited application, the limitations are also discussed.
10-MEV. X-Ray Technique
Authors: O'Connor D. T. , Criscuolo E. L. , Pace A. L.
Published: July 2009

In October, 1948, a 10-mev. betatron was installed at the Naval Ordnance Laboratory and put into operation. The installation of a 2-mev generator in the same room had to be completed and many building and operational details taken care of before the use of the betatron was anything but sporadic. This work was completed in March, 1949, and since that time the 10-mev. unit has been in almost continuous use. The magnet of the betatron, Fig. 1, is crane mounted, has a positioning area of 18 by 30 ft., may be rotated and tilted. Power and cooling water to the oil immersed magnet are supplied through pendant lines. The power supply and regulation circuits are mounted on the maze roof within the exposure room, and the console control desk, in an adjoining room. The principal application of this betatron is the radiography of large critical items. Therefore, the determination of the radiographic characteristics of 10-mev. radiation was necessary.
Examination of Plated and Protective Coatings by Electrographic Analysis
Authors: Galitzine N. , Ashley S. E. Q.
Published: July 2009

The principles of electrographic analysis have been described elsewhere in this symposium. This paper will deal only with the application of electrographic analysis to the study of plated or coated surfaces, and more specifically to the examination of surfaces for the continuity of coatings or for the presence of holes. Electrographic analysis is often thought of as a method for either qualitative or semiquantitative tests for metals, but if one works with a tremendous diversity of metals and alloys, other methods are to be considered more reliable. For example, for qualitative tests the authors prefer spectrographic and X-ray diffraction analysis, and for quantitative or semiquantitative determinations they prefer spectrographic, polarographic, or chemical methods. But when one is concerned with studies on continuity of plated surfaces, protective coatings, or examination of position of one known metal in respect to another— the only practical and quick method is electrographic analysis. Using the same method as was described in other papers in this symposium, the sample is made positive, the electrode negative, and paper impregnated with electrolyte is used in between. If holes are present in the surface coating, a small amount of metal is transferred from the base metal into the paper by the passage of current. A color characteristic of the metal being tested for is then developed with an appropriate reagent. It is always known in advance, what the base metals and coatings are. The base material of course has to be an electrical conductor, but the coatings do not have to be. They may be metallic, inorganic, or organic coatings.
Introduction
Authors: Eberhart Howard D.
Published: July 2009

During recent years many types of new equipment and corresponding new techniques have been developed for making and interpreting dynamic measurements. Most of these developments have involved electrical or electronic devices and a field of specialization generally unfamiliar to engineers concerned with research upon, and investigation of, materials and structures. Investigation of dynamic conditions has become increasingly important. No single source of information has been available that presented the scope, applicability, possibilities and limitations of electronic measuring and recording devices. The present group of four papers has been prepared to assist the individual who may be responsible for initiating such tests, or who may have to make practical application of the results of such tests. The general title “Dynamic Stress Determinations” was a compromise and has been interpreted to include the phenomena associated with the dynamic state which would be of principal interest to engineers in the field of materials and structures. In most cases this may be stress, but since this is a “determined” quantity and is indirectly obtained from measured strains, deflections, displacements, velocities, accelerations, etc., specific attention is directed toward such related quantities. The computation of stresses from the quantities measured is not considered here, that being the process generally most familiar to testing engineers. The subject is more limited than that of “dynamic testing” which is a general term including not only the recording and interpretation of dynamic phenomena but also the control of the load variable and the validity of such tests. The principles involved in the measuring and recording system for any dynamic condition are in general similar, the resulting simplicity or complexity being governed by correct knowledge of the factors involved and the type of end results desired.
Petroleum Lubricating Greases
Authors: Chittick Martin B.
Published: July 2009

The American Society for Testing Materials has denned petroleum grease in the Standard Definitions of Terms Relating to Petroleum (A.S.T.M. Designation: D 288-39) as follows: “A semisolid or solid combination of a petroleum product and a soap or a mixture of soaps, with or without fillers, suitable for certain types of lubrication.” The scope of this paper is primarily limited to products falling within the limits of this definition, the trend in research in the field of lubricating greases, and the various physical and chemical tests that have been developed for application to control the quality of greases, as well as predicting their service performance. Due to the fact that the term “lubricating grease” is a generic one, a sharp line of demarcation between certain classes of lubricants is impossible. It is for this reason that the above definition, while definitely a progressive step, leaves much to be desired. Take, for a typical example, the so-called extreme-pressure lubricants, which fall into two general classes. In the first class can be placed the lead soap—active sulfur type of extreme pressure lubricant, which falls within the definition of a petroleum lubricating grease. As against this type of lubricant, we have the extreme-pressure lubricant consisting of mineral oil with an organic additive agent, which, in general is commercially considered as a grease, yet does not fall within the scope of the definition.
The Status of Research on Fuels and Lubricating Oils for Spark-Ignition Aircraft Engines
Authors: Heron S. D.
Published: July 2009

This discussion deals only with fuels and lubricants used in spark-ignition aircraft engines, and no statement made can be considered as necessarily having any bearing on other types of engines. This survey represents the author's findings as of November, 1937.
Epigenetics and Neonatology
Authors: Morley Ruth , Saffery Richard , Hacking Douglas F. , Craig Jeffrey M.
Published: July 2009

Although an individual's cells all have the same DNA, each cell type has a different pattern of active (expressed) and inactive genes. Such patterns are established or programmed during development by epigenetic modifications involving small molecules that covalently bind to specific sites in DNA or DNA-packaging proteins. The modifications regulate gene activity without changing the DNA sequence. Diet, lifestyle factors, and exposure to toxins or other adverse factors as well as random epigenetic mutations can result in de novo epigenetic modifications that may influence the course of development. The perinatal period is a time of rapid physiologic change during which some epigenetic reprogramming is likely to occur. Further, adverse events at this time may lead to epigenetic changes that have implications for future health and well-being. Evidence suggests that epigenetics plays a part in mediating effects of the perinatal environment and that such epigenetic changes may be reversed later in life. This has major implications for understanding of the cause of preterm birth as well as the consequences of prematurity.
The requirements and difficulties of patient movement during medical nursing
Authors: Szabó Péterné
Published: July 2009

A mozgásszervi megbetegedések gyakori panaszt okoznak az ápolói hivatást gyakorlók körében. Ennek kialakulásában több tényező is szerepet játszik. Az intenzív megterhelő munka, a stressz, a munkahelyi kiégés, a krónikus kimerültség és a depressziós állapotok előfordulása [1]. A mindennapi munka során a rossz munkakörülmények, az alacsony ápolói létszám, a változások követése okozta komplex igénybevétel testi és lelki zavarokhoz vezethet. A túlfeszített munka, az oktatás eredménytelensége, az atraumatikus betegmozgatási módszerek alkalmazásának ismerethiánya szintén hozzájárulhat a fenti következmények kialakulásához. Nemcsak Magyarországon, hanem a világ fejlett országaiban is előkelő helyet foglalnak el a mozgásszervi megbetegedések. Ezt a tényt a betegellátásban dolgozó ápolók munkahelyi körülményei is növelik (nem megfelelő betegágyak, hiányos segédeszközök, mozgatási technikák ismeretének hiányossága stb.), megalapozva annak kockázatát, hogy hátsérüléssel kapcsolatos megbetegedést szenvedjenek el. Ha az ápoló kiesik a munkából, akkor személye nehezen pótolható, figyelembe véve a mai magyar ápolóoktatást. A szakma nem vonzó az érettségire épülő képzések körében. Egyelőre nem biztosított az a motiváció, ami ezt megváltoztatja, sem anyagilag, sem erkölcsileg. A magyar szakirodalmi adatok között kevés publikáció található, amely a témával felmérési adatokkal alátámasztva foglalkozik. Ez természetesen nem azt jelenti, hogy a magyar egészségügy területén dolgozók között ez a probléma nem létezik, illetve nem olyan mértékű, mint a külföldi szakirodalom közlései alapján. Az Egészségügyi Szakképző és Továbbképző Intézet az egészségügyi tárca felkérésére az ápolók betegemelésből, -mozgatásból eredő terhelésének felmérésére 1998-ban végzett vizsgálatot [2]. Az Európai Unióhoz való csatlakozás kapcsán felmerülő jogharmonizációs program részeként olyan irányelveket kellett beépíteni, amely a minimális egészségi és biztonsági követelményeket tartalmazták elsősorban a hát- és deréktáji sérülések kockázatával járó kézi tehermozgatást illetően. A vizsgálat eredményeként közölték, hogy egy ápolónak munkanaponként, átlagosan 60 kg-os beteget figyelembe véve, körülbelül 2000–2800 kg súlyt kell az ápolás során megmozgatnia, ezért nagy a sérülések aránya. A minta nagyságát 129 kérdőív értékeléséből végezték, az eredményt az intézmények típusai (22 intézmény) tükrözte. Ennek értelmében az ápolók napi átlagban 23 beteget ápolnak, a válaszadók 10%-a ezt teljesen egyedül teszi, 32%-a párban dolgozik, 58%-a szükség esetén kap segítséget [2].
Plasma apelin levels in obstructive sleep apnea and the effect of continuous positive airway pressure therapy
Authors: Henley David E , Buchanan Fiona , Gibson Rosemary , Douthwaite Jennie A , Wood Susan A , Woltersdorf Wolfram W , Catterall James R , Lightman Stafford L
Published: July 2009

Apelin is a peptide hormone with cardiovascular and glucose homeostasis properties, and obstructive sleep apnea (OSA) is complicated by cardiovascular and metabolic comorbidities. Plasma apelin has not been previously assessed in OSA. We investigated the response of plasma apelin to a 2-h 75 g oral glucose tolerance test (OGTT) and the effect of 3 months compliant continuous positive airway pressure (CPAP) therapy in 15 obese males with newly diagnosed OSA. Plasma apelin and serum cortisol were recorded 10 minutely, while serum insulin and glucose were measured 30 minutely. Ten subjects had plasma apelin measured at intervals across a 24-h period to investigate for circadian variation in apelin levels, and this was repeated following 3 months compliant CPAP therapy. Fasting (0.342±0.038 vs 0.288±0.024 ng/ml, P=0.04), 30 min (0.399±0.035 vs 0.312±0.036 ng/ml, P=0.007) and 120 min (0.402±0.030 vs 0.259±0.024 ng/ml, P<0.001) apelin levels were reduced following CPAP. The area under curve for apelin OGTT response was lower post-CPAP (44.1±3.3 vs 35.8±2.3 ng/ml per min, P<0.001). Mean OGTT apelin levels showed a significant treatment effect (P=0.006) and a time effect (P<0.001), and the effect of time was different pre- versus post-CPAP (P=0.005). No significant variability in apelin levels existed across the 24-h period at diagnosis. Lower levels were evident overnight following treatment (P=0.004). Improvements in insulin and glucose parameters and reduced cortisol levels were found post-CPAP. In summary, untreated OSA was associated with elevated plasma apelin levels, altered apelin secretory dynamics in response to oral glucose and lack of an apparent circadian variability, which was restored following CPAP.
THE STAY/SWITCH MODEL OF CONCURRENT CHOICE
Authors: MacDonall James S.
Published: July 2009

This experiment compared descriptions of concurrent choice by the stay/switch model, which says choice is a function of the reinforcers obtained for staying at and for switching from each alternative, and the generalized matching law, which says choice is a function of the total reinforcers obtained at each alternative. For the stay/switch model two schedules operate when at each alternative. One arranges reinforcers for staying there and the other arranges reinforcers for switching from there. Rats were exposed to eight or nine conditions that differed in the arrangement of the values of the stay and switch schedules. The generalized matching law described preferences when arrangements were similar to those found when using two concurrently running interval schedules. It did not, however, describe all preferences when using different arrangements. The stay/switch model described all preferences in one analysis. In addition, comparisons of selected conditions indicated that changing the ratio of obtained reinforcers was neither necessary nor sufficient for changing preference as measured by response ratios. Taken together these results provide support for the stay/switch model as a viable alternative to the generalized matching law and that the critical independent variable is allocation of stay and switch reinforcers.
Correlations To Predict Frictional Pressure Loss of Hydraulic-Fracturing Slurry in Coiled Tubing
Authors: Shah Subhash , Zhou Yunxu , Bailey Michael , Hernandez John
Published: July 2009

Compared with conventional-tubing fracturing, coiled-tubing (CT) fracturing has several advantages. CT fracturing has become an effective stimulation technique for multizone oil and gas wells. It is also an attractive production-enhancement method for multi-seam coalbed-methane wells, and wells with bypassed zones. The excessive frictional pressure loss through CT has been a concern in fracturing. The small diameter of the string limits the cross-sectional area open to flow. Furthermore, the tubing curvature causes secondary flow and results in extra flow resistance. This increased frictional pressure loss results in high surface pumping pressure. The maximum possible pump rate and sand concentration, therefore, have to be reduced. To design a CT fracturing job properly, it is essential to predict the frictional pressure loss through the tubing accurately.

This paper presents correlations for the prediction of frictional pressure loss of fracturing slurries in straight tubing and CT. They are developed on the basis of full-scale slurry-flow tests with 1½-in. CT and slurries prepared with 35 lbm/1,000 gal of guar gel. The extensive experiments were conducted at the full-scale CT-flow test facility. The proposed correlations have been verified with the experimental data and actual field CT-fracturing data. Case studies of wells recently fractured are provided to demonstrate the application of the correlations. The correlations will be useful to the CT engineers in their hydraulics design calculations.
A Procedure for Assessing the Value of Oilfield Sensors
Authors: Gilbert R. B. , Lake L. W. , Jablonowski C. J. , Jennings J. W. , Nunez E. J.
Published: July 2009

Spurred by improvements in reliability, cost, and accuracy, sensors offer a means of increasing expected ultimate hydrocarbon recovery in producing assets as well as in planned and prospective projects. Ultimate hydrocarbon recoveries larger than those currently achieved are possible, especially when sensors are used with advanced recovery methods. However, it is often unclear if the incremental recovery justifies the cost of installing the sensors. This paper proposes a method for estimating incremental values attributable to real-time sensors and provides a demonstration of the method for several production technologies and reservoir settings. The method offers a transparent and practical means of making value of information (VOI) computations to be implemented readily by project teams. An additional benefit of this method is that the process of specifying the inputs to the analysis facilitates a systematic discussion of strengths and weaknesses, and builds consensus regarding assumptions. The method is applied to four scenarios developed by a panel of industry experts to represent generic, but yet realistic reservoirs. The results for these scenarios indicate the value of sensors depends on the market price for product and the type of reservoir and production technology. The greatest absolute economic value for the use of sensors is obtained for a deepwater reservoir, while the greatest economic value per equivalent barrel of oil produced is obtained for a mature onshore reservoir. These expected economic values are intended to be compared to the cost required to implement the sensors to assess whether or not there is an expected net benefit.
Innovative Use of Kaolinite in Downhole Scale Management: Squeeze-Life Enhancement and Water Shutoff
Authors: Fleming Niall , Ramstad Kari , Mathisen Anne-Mette , Nelson Alex , Kidd Sam
Published: July 2009

Applied research has been undertaken to examine the potential of kaolinite combined with a kaolinite-fixation agent to increase squeeze lifetime through alteration of near-wellbore surface characteristics and mineralogy, and to provide water-shutoff control.

With respect to enhancing squeeze lifetime, it is documented that kaolinite increases the quantity of inhibitor adsorbed. Conversely, clean sandstone with low clay content commonly provides a poor substrate for adsorption. Furthermore, in reservoirs that experience near-wellbore formation damage because of kaolinite mobilization, it has been shown that the use of a fixation agent as part of a squeeze treatment can increase squeeze lifetime. Using these facts, research has assessed the feasibility of injecting micro-crystalline kaolinite (average particle size 2 μm) combined with the fixation agent and scale inhibitor as a means of mechanically altering near-wellbore mineralogy and surface-property characteristics within clean, high-permeability sandstones. The testing has been designed to mimic the squeeze procedure used in the field for performing such a job and involves no additional steps to those used in a normal squeeze (i.e., preflush, main treatment, overflush). The paper presents the results of coreflood experiments that demonstrate "proof of concept," along with examples of potential field applications.

A further concept, born from the initial idea, was the use of kaolinite and fixation agent for efficient, low-cost, environmentally friendly water shutoff. There are several available products for water shutoff, but the disadvantage of these is that they are not acceptable for use in Norway because of poor environmental characteristics. Hence, there was a need to fill this gap by developing water-shutoff technology to meet country-specific environmental legislation. The paper provides details of coreflood testing where an excess of kaolinite has been used to form an internal and external filter cake that is attached to the wellbore face and within the near-wellbore region using the fixation agent.

The paper draws on data from StatoilHydro-operated fields in order to highlight the potential of this innovative approach to downhole scale management and water control.
Coupled Adsorption/Precipitation of Scale Inhibitors: Experimental Results and Modeling
Authors: Kahrwad M. , Sorbie K. S. , Boak L. S.
Published: July 2009

In this paper, results are presented on the general mechanisms by which scale inhibitors (SIs) are retained within porous media. There is a generally accepted view that the main two mechanisms of SI retention are "adsorption" and "precipitation," and these are described by different but related modeling approaches in the literature. These approaches have been used quite successfully to model field squeeze treatments. To analyze in a detailed and unambiguous manner where a given retention mechanism (e.g., pure adsorption) or mechanisms (e.g., coupled adsorption and precipitation) are operating requires that we carry out careful laboratory experiments under "field relevant" conditions.

In this work, we study adsorption vs. adsorption/precipitation by performing a series of experiments where we know that the system exhibits either (a) adsorption only or (b) coupled adsorption/precipitation. Experimentally, it is straightforward to determine which regime the system is in. We present the theory describing the coupled adsorption/precipitation process. In addition, an extensive series of experimental adsorption/precipitation measurements is presented for various mineral separates including sand, chlorite, siderite, muscovite, kaolinite, and feldspar. The coupled adsorption/precipitation model is in very good agreement with the experiment.
Soybean Yield and Soybean Cyst Nematode Densities Related to Soil pH, Soil Carbonate Concentrations, and Alkalinity Stress Index
Authors: Rogovska N. P. , Blackmer A. M. , Tylka G. L.
Published: July 2009

Soybean [Glycine max (L.) Merr.] grown on high pH, calcareous soils often suffer yield loss due to unavailability of Fe. Further yield decline can occur due to infestations by soybean cyst nematodes (Heterodera glycines Ichinohe; SCN) that are often present in greater numbers in high‐pH soils. An observational study was conducted from 2001 to 2005 in Iowa to examine the relationships among: pH; CaCO3 equivalent (CCE); alkalinity stress index (ASI), which combines pH and CCE in one value; SCN; and soybean grain yield of SCN‐resistant and susceptible cultivars. The study was conducted within 23 fields that had marked variability in soybean growth. Remote sensing of soybean canopies was used to help identify 10 to 16 sampling areas within each field. Soil samples were analyzed for pH, CCE, and SCN population densities. Grain samples were used to calculate relative yields (RY) in each field. The RY declined with increases in pH, CCE, ASI, and SCN densities more for SCN‐susceptible than resistant cultivars. The ASI explained a greater percentage of variability of soybean yield than did pH or CCE alone. The ASI explained 18 and 45% of yield variability of SCN‐resistant and susceptible cultivars, respectively, while pH explained 13% (SCN‐resistant) and 36% (SCN‐susceptible) and CCE explained 15% (SCN‐resistant) and 32% (SCN‐susceptible) of yield variability, respectively. The SCN population densities were more strongly related to soil pH than to CCE. The ASI explained the same proportion of variability in SCN population densities as did soil pH.
Potential for Delayed Orchardgrass Seeding during Glyphosate‐Resistant Alfalfa Establishment
Authors: Dillehay Bryan L. , Curran William S. , Hall Marvin H.
Published: July 2009

Few herbicides are labeled for weed control when establishing alfalfa (Medicago sativa L.)‐grass mixtures. Varying the planting date of the grass in relation to alfalfa and adjusting herbicide application timing could improve weed control and forage grass safety. The research objective was to evaluate the use of glyphosate [N‐(phosphonomethyl) glycine] for weed control in seedling glyphosate‐resistant alfalfa mixed with orchardgrass (Dactylis glomerata L.). Orchardgrass was seeded with alfalfa or 4 and 5 wk after alfalfa; while glyphosate was applied 4 wk after planting and all treatments included an untreated check. First year harvests varied in composition and orchardgrass was slower to establish than alfalfa. At the first harvest, glyphosate treatments had 17 to 35% higher alfalfa content, reduced or similar orchardgrass content, and 75 to 90% lower weed content than treatments without glyphosate. By the third harvest of the establishment year, weed biomass in the 4 and 5 wk after planting treatments not treated with herbicide was at least 4.5 times greater and orchardgrass content was the same or less than the comparable glyphosate treatments. Forage species composition and weed control differences present during the establishment year dissipated during the second year of the study. By 2 yr after establishment, orchardgrass content was lower only in the first two cuttings when orchardgrass was seeded with the alfalfa and a glyphosate application followed, a practice not generally recommended. This study demonstrates the utility of glyphosate in glyphosate‐resistant alfalfa and should provide some guidance for establishment of successful alfalfa‐grass mixtures.
Erosion Index Derived from Terrain Attributes using Logistic Regression and Neural Networks
Authors: Pike A. C. , Mueller T. G. , Schörgendorfer A. , Shearer S. A. , Karathanasis A. D.
Published: July 2009

Maps identifying areas prone to channel erosion within agricultural fields could be useful for conservation planners. The objective of this study was to test an approach for creating such maps with logistic regression and neural networks. Survey grade elevation measurements were obtained from on a Central Kentucky farm. The elevation measurements were used to create 4 by 4‐m digital elevation models (DEMs) from which terrain attributes were derived. Areas exhibiting evidence of erosion caused by overland water flow sufficient to justify the placement of grassed waterways were identified. The terrain attributes were used as predictor variables and models were fit using the field assessments of soil erosion. Leave‐one‐field‐out validation analysis was conducted to assess the quality of predictions maps. For the models created with logistic regression, an average of 14% of the 4 by 4‐m grid cells in noneroded areas were incorrectly classified as being eroded and 16% of cells in eroded areas were incorrectly classified as noneroded. For neural network analysis, these error rates were 15 and 19%, respectively. Most of these errors occurred because the analyses did not exactly define the shapes of the eroded features; however, both logistic regression and neural networks identified most waterway features in all fields. The proposed three‐variable logistic regression model for erosion prediction should only be tested with datasets constructed using identical procedures for DEM creation and terrain analysis. This approach could improve the efficiency and accuracy of field site assessments for conservation planning.
Cattle Manure Application Strategies Effects on Bahiagrass Yield, Nutritive Value, and Phosphorus Recovery
Authors: Obour A. K. , Silveira M. L. , Adjei M.B. , Vendramini J. M. , Rechcigl J. E.
Published: July 2009

Animal manure application based on crop N requirements often leaves excess P in the soil because of the differences in the N/P ratio in manures and that required by the plants. This experiment was designed to evaluate the effects of cattle (Bos taurus) manure applied alone or in combination with ammonium nitrate (AN) on bahiagrass (Paspalum notatumFlügge) dry matter (DM) yield, nutritive value, tissue P concentration and recovery, and soil P concentrations. Treatments consisted of a control, two N rates (200 and 400 kg ha−1), two N sources [manure alone or manure plus AN (50/50% combination)], and two application frequencies (single vs. split). Bahiagrass was harvested at 28‐d intervals and evaluated for DM yield, crude protein concentration (CP), in vitro digestible organic matter (IVDOM), and tissue P concentration. Soil samples were analyzed for Mehlich‐1 extractable P. Bahiagrass DM yield, nutritive value, and P recovery were greater for the manure plus AN treatments when compared to the control and manure alone. Although greater N rates increased DM yield and CP, bahiagrass P recovery was reduced as the N rate increased. Approximately 20 and 53% of the applied P was recovered by bahiagrass when manure was applied alone and in combination with AN, respectively. Soil‐test P (0–15 cm depth) was greater for the treatments receiving manure alone compared to manure plus AN treatments. Our results demonstrated that applying manure in combination with an inorganic N source can increase forage yield and nutritive value while reducing the risks of soil P accumulation.
Seed Yield and Yield Stability of Chickpea in Response to Cropping Systems and Soil Fertility in Northern Latitudes
Authors: Gan Y. T. , Warkentin T. D. , McDonald C. L. , Zentner R. P. , Vandenberg A.
Published: July 2009

Improved cultural practices are required to enhance the adaptability of chickpea (Cicer arietinum L.) in northern latitudes. Field experiments were conducted to determine the effects of cropping systems, cultivar choices, and soil fertility on the stand establishment, seed yield, and yield stability of chickpea in northern latitudes. Four cultivars were tested in no‐till barley (Hordeum vulgare L.), no‐till wheat (Triticum aestivum L.), and tilled‐fallow systems at six environments in southern Saskatchewan, 2004–2006. Crop received N fertilizer at 0, 28, 64, 84, and 112 kg N ha−1 with or without Rhizobium inoculant (GR). The no‐till barley and no‐till wheat systems did not differ from the tilled‐fallow system in days to plant emergence and stand establishment, and the two no‐till systems averaged 2100 kg ha−1of seed yield which was 83% of the yield in the tilled‐fallow system. In the absence of GR, increasing N rates increased seed yield significantly in the two no‐till systems, no yield responses in the tilled‐fallow system, and decreased plant density in all the three systems. Compared to the non‐GR control, the use of GR increased seed yield by 37% in the no‐till systems and 8% in the tilled‐fallow system. Chickpea inoculated with GR produced a similar yield as was fertilized at 112 kg N ha−1. Chickpea receiving fertilizer N plus GR produced a similar yield as the crop received GR only for all cultivars. Use of optimal cropping systems, improved cultivars with high yield stability, and application of effective N‐fixing inoculants will enhance the adaptability of chickpea in northern latitudes.
Soil Moisture and Metolachlor Volatilization Observations over Three Years
Authors: Gish Timothy J. , Prueger John H. , Kustas William P. , Daughtry C.S.T. , McKee Lynn G. , Russ Andy , Hatfield Jerry L.
Published: July 2009

A 3‐yr study was conducted to focus on the impact of surface soil water content on metolachlor (2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1‐methylethyl) acetamide) volatilization from a field with different surface soil water regimes created by subsurface water flow paths. Metolachlor vapor fluxes were measured at two locations within the field where local meteorological and soil conditions were relatively constant, except for surface soil water content, which differed significantly. Surface soil water content at the two sites differed in response to the presence of subsurface flow pathways. Detailed soil moisture observations over the duration of the study showed that for the first 2 yr (2004 and 2005), surface soil water contents at the dry location (V1) were nearly half those at the wetter location (V2). Cumulative metolachlor vapor fluxes during 2004 and 2005 at V1 were also about half that at V2. In the third year (2006), early‐season drought conditions rendered the soil water content at the two locations to be nearly identical, resulting in similar metolachlor volatilization losses. Analysis of infrared soil surface temperatures suggests a correlation between surface soil temperatures and metolachlor volatilization when soils are wet (2004 and 2005) but not when the soils are dry (2006). Field‐averaged metolachlor volatilization losses were highly correlated with increasing surface soil water contents (r2 = 0.995).
Strategies to Promote Evidence-Based Practice in Pediatric Physical Therapy: A Formative Evaluation Pilot Project
Authors: Schreiber Joe , Stern Perri , Marchetti Gregory , Provident Ingrid
Published: July 2009

Background

The physical therapy profession has been perceived as one that bases its practice largely on anecdotal evidence and that uses treatment techniques for which there is little scientific support. Physical therapists have been urged to increase evidence-based practice behaviors as a means to address this perception and to enhance the translation of knowledge from research evidence into clinical practice. However, little attention has been paid to the best ways in which to support clinicians’ efforts toward improving evidence-based practice.

Objectives

The purpose of this study was to identify, implement, and evaluate the effectiveness of strategies aimed at enhancing the ability of 5 pediatric physical therapists to integrate scientific research evidence into clinical decision making.

Design

This study was a formative evaluation pilot project.

Methods

The participants in this study collaborated with the first author to identify and implement strategies and outcomes aimed at enhancing their ability to use research evidence during clinical decision making. Outcome data were analyzed with qualitative methods.

Results

The participants were able to implement several, but not all, of the strategies and made modest self-reported improvements in evidence-based practice behaviors, such as reading journal articles and completing database searches. They identified several barriers, including a lack of time, other influences on clinical decision making, and a lack of incentives for evidence-based practice activities.

Conclusions

The pediatric physical therapists who took part in this project had positive attitudes toward evidence-based practice and made modest improvements in this area. It is critical for the profession to continue to investigate optimal strategies to aid practicing clinicians in applying research evidence to clinical decision making.
Multimodal Mesoscopic Approach in Modeling Pedestrian Evacuation
Authors: Di Gangi Massimo , Velonà Pietro
Published: July 2009

A recently funded research project in Italy concerned reduction in risk exposure in urban areas through the definition and the implementation of evacuation procedures. One of the research aims was to specify and calibrate a system of models that could simulate the transportation system when a population must evacuate because of approaching disaster. Various activities were conducted to calibrate a set of cost functions to be implemented within a dynamic network loading procedure to simulate pedestrian outflow related to the evacuation of a building. How flow models are calibrated on the basis of data collected during experimentation at a test site is shown, and the results of their implementation within a multimodal dynamic loading model used to simulate evacuation procedures are described. A comparison between experimental data and simulation results shows that the use of appropriate simulation models can realistically reproduce user behavior and then shows how such models can be used as a support for creating effective evacuation plans. The experimentation involved evacuation of a primary school in an Italian town, but the method applied can be adapted easily to any public building with homogenous characteristics.
Real-Time Control of Buses in a Transit Corridor Based on Vehicle Holding and Boarding Limits
Authors: Delgado Felipe , Muñoz Juan Carlos , Giesen Ricardo , Cipriano Aldo
Published: July 2009

A real-time mathematical programming model of buses operating on a transit corridor that incorporates vehicle-capacity constraints is proposed. The objective for the model is to minimize the total times experienced by all passengers in the system, from the moment they arrive at a stop to the moment they reach their destination. Two control policies are considered: (a) vehicle holding, which is applicable at any stop, and (b) boarding limits that constrain the number of passengers entering a vehicle even when the vehicle is at less than physical capacity, to increase operating speed. The objective function is quadratic, but not convex with linear constraints. This problem is solved by using MINOS in a reasonable amount of computation time. A case study in a high-demand scenario shows that the proposed control achieves reductions in the objective function of more than 22% and 12% compared with no control and only holding strategies, respectively.
Dynamic Pricing with Heterogeneous Users
Authors: Lu Chung-Cheng , Mahmassani Hani S.
Published: July 2009

The bicriterion dynamic user equilibrium (BDUE) model characterizes the dynamic user equilibrium (DUE) in a network resulting from the path choice interactions of a population of heterogeneous trip makers with different values of time (VOT). The BDUE model represents an attempt to accommodate greater behavioral and policy realism in applying DUE models to designing and evaluating dynamic pricing strategies. It also represents an advance in generalizing heterogeneous user equilibrium models from the static regime to the dynamic traffic-assignment context. To effectively obtain time-varying path-flow patterns satisfying the BDUE conditions, a study was done to adapt the gap-driven and simulation-based algorithmic framework to solve the DUE problem (with a constant VOT). Especially, the proposed BDUE algorithm is a column generation-based approach that integrates the following components: (a) a simulation-based dynamic network loading model that captures traffic dynamics and determines experienced path travel times for a given time-varying path-flow pattern, (b) a path generation scheme that partitions the entire range of VOT into many subintervals and accordingly determines the corresponding multiple user classes and the least-generalized cost (i.e., extreme nondominated) paths for each user class, and (c) a multiclass path flow equilibrating method for updating the current path assignment. The results of the experiments conducted on several real networks show that the convergence pattern of the proposed algorithm is not affected by different VOT assumptions, and it is able to find close-to-BDUE solutions.
Robust Approach to Discrete Network Designs with Demand Uncertainty
Authors: Lou Yingyan , Yin Yafeng , Lawphongpanich Siriphong
Published: July 2009

A discrete network design problem under demand uncertainty is considered. It is assumed that the future travel demand for each origin-destination (O-D) pair can take on nominal or one of several other values, where the probabilities of occurrence of these values are unknown. However, the vector of O-D demands realized for the network must belong to an uncertainty set, a set that allows demands for a group of O-D pairs to deviate from their nominal values simultaneously. A robust counterpart of deterministic discrete network design is formulated as a mathematical program with complementarity constraints under the Wardropian user equilibrium conditions. The algorithm proposed for the problem terminates in a finite number of iterations and converges to a global optimum solution under certain conditions. Numerical results that use two networks from the literature empirically demonstrate that the algorithm is effective and has the potential to solve realistic problems.
Surgical anatomy and functional connectivity of the limbic system
Authors: Lövblad Karl-Olof , Schaller Karl
Published: July 2009

Object

The goal in this study was to highlight the potential of currently available imaging techniques for surgical planning of procedures in and around the limbic system.

Methods

The authors review traditional and newer imaging techniques as applied to neurosurgical planning. Today MR imaging techniques play a preponderant role. The various applications of functional techniques such as diffusion weighted, diffusion tensor, perfusion, and functional MR imaging methods are discussed.

Results

In addition to the high-resolution studies of anatomy that can be acquired, especially at higher field strengths (≥ 3 T), MR imaging now also offers the possibility of acquiring functional, metabolic, hemodynamic, and molecular information on normal and pathological brain processes.

Conclusions

The knowledge obtained using the various imaging techniques contributes substantially to understanding the disease processes in a way that drastically improves surgical planning.
Functional outcome after language mapping for insular World Health Organization Grade II gliomas in the dominant hemisphere: experience with 24 patients
Authors: Duffau Hugues , Moritz-Gasser Sylvie , Gatignol Peggy
Published: July 2009

Object

Despite the report of recent experiences of insular surgery in the past decade, there has been no series specifically dedicated to studying functional outcome following resection of insular WHO Grade II gliomas involving the dominant hemisphere, in patients with no or only mild preoperative language deficit. In this article, the authors analyze the contribution of awake mapping for preservation of brain function, especially language, in a homogeneous series of 24 patients who underwent surgery for insular Grade II gliomas within the dominant insular lobe.

Methods

Twenty-four patients underwent surgery for an insular Grade II glioma involving the dominant hemisphere (22 left, 2 right), revealed by seizures in all but 1 case. The preoperative neurological examination result was normal in 17 patients (71%), whereas 7 patients presented with language disorders detected using an accurate language assessment performed by a speech therapist. All surgeries were performed on awake patients utilizing intra-operative language mapping involving cortical and subcortical stimulation.

Results

There were no intrasurgical complications or postsurgical sensorimotor deficits. Despite an immediate postoperative language worsening in 12 cases (50%), all patients recovered to a normal status within 3 months, and 6 cases even improved in comparison with their preoperative examination results. The 24 patients returned to normal social and professional lives. Moreover, the surgery had a favorable impact on epilepsy in all but 4 cases (83%). On control MR imaging, 62.5% of resections were total or subtotal. Three patients underwent a second or third awake surgery, with no additional deficit. All but 2 patients (92%) are alive after a mean follow-up of 3 years (range 3–133 months).

Conclusions

Although insular surgery was long believed to be too risky, the present results show that the rate of permanent deficit, especially dysphasia, following resection of Grade II gliomas involving the dominant insula has been dramatically reduced (none in this patient series), thanks to the systematic use of intraoperative awake mapping, even in cases of repeated operations. Furthermore, patient quality of life may be improved due to a decrease of epilepsy after surgery. Thus, the authors suggest systematically considering resection when an insular Grade II glioma is diagnosed after seizures in a patient with no or mild deficit, even a glioma invading the dominant hemisphere.