bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting Service Life in a Fatigue-Creep Environment
Authors: Ellison EG , Smith EM
Published: March 2009

Two current approaches to prediction of life to crack initiation are reviewed, the first based on modification of fatigue types of analyses, the second on use of cumulative fatigue and creep damage models. Methods of allowing for stress and strain concentrations are examined, and attention directed to the possibility of environment significantly affecting results. The fracture mechanics approach to estimating rates of crack propagation is discussed.

For computer analyses of highly critical sections of components, formulation of constitutive equations on a continuum-metallurgical basis is considered, some possible directions for future work are indicated. An example of prediction of failure through growth of voids in creep is given.

Finally, present design practice is outlined, and the importance of accurate knowledge of service conditions emphasized.
Some Considerations of the Application of Cyclic Data to the Design of Welded Structures
Authors: Darlaston BJL , Walters DJ
Published: March 2009

The behavior of a transition joint between 2¼Cr-Mo and Type 316 stainless steel has been analysed. The results are used to define the condition for accelerated laboratory testing under cyclic conditions. The relevance of conventional design methods is discussed, and a design approval route is defined.
Nondestructive Testing in Fatigue: A 1972 Update
Authors: Socky RB
Published: March 2009

The application of nondestructive testing (NDT) to the engineering aspects of the fatigue phenomenon offers a classic example of the systems approach that is essential for the successful exploitation of nondestructive testing technology. NDT can make contributions in: the fracture mechanics-nondestructive testing design criteria and related product integrity determination; detection of property-stress gradients; early detection of fatigue damage; and evaluation of stresses.

Earlier work established the ascendancy of ultrasonic testing. Notable advancements in recent work have been in the refinement of data treatment of ultrasonic responses from defects aimed at accomplishing more reliable size assessment and in scanning of large components.

The following NDT methods have demonstrated potential for measurement of fatigue damage: exoelectron emission, acoustic emission, ultrasonic surface wave attenuation and velocity, surface potential difference, ellipsometric parameters, holographic surface correlation index, and positron life times.

Stresses play an important role in failure point detection, location, and growth, and in practical cases, must be measured for each part.

Effective utilization of nondestructive testing at any one portion of the product cycle as related to the fatigue problem requires that it be considered in a system connotation.
Analysis of Pavement Slipperiness in Alabama
Authors: Bransford TL
Published: March 2009

The objective of this research was to determine the causes of pavement slipperiness in Alabama, develop remedies for eliminating pavement slipperiness, and make recommendations for specifications for future pavements which would ensure satisfactory skid resistance in them during their anticipated service lives.

The skid test data were obtained by the Alabama State Highway Department. The analysis of the data was made by the Engineering Experiment Station of Auburn University, Auburn, Ala.

All skid tests were made using a two-wheel skid trailer meeting the requirements of ASTM Specification E 274-65 T equipped with tires meeting ASTM Specification E 249-66. All data were obtained by locking the left wheel only at a speed of 40 mph.

The results of this research indicate that the use of limestone as a coarse aggregate in asphalt plant mixes and surface treatments produces slippery pavements apparently due to polishing under traffic.

They further indicate that well-graded coarse sands, when used as fine aggregate in asphaltic concretes, make a significant contribution to their skid resistance. The same is true when they are used in hot-sand asphalt hot mixes.

Gravels and granites, when used as coarse aggregates in asphaltic concrete plant mixes, produce pavements that are fairly skid resistant but caution must be exercised by vehicle drivers on these pavements when they are wet.

The most skid resistant pavements in the plant mix and surface treatment groups are those incorporating slag as a coarse aggregate.

Most Portland cement concrete pavements are highly skid resistant until they have been exposed to heavy traffic loads for long periods of time.

The net result of this research is that fairly definite guidelines have been developed for writing specifications for future pavements in Alabama that will ensure skid resistant pavements. As a result there should be a marked reduction in the number of skidding accidents in the state.
High Speed Skid Resistance and the Effects of Surface Texture on the Accident Rate
Authors: Moore AB , Humphreys JB
Published: March 2009

Equipment was designed and built to conduct skid resistance tests at speeds up to 75 mph. Results of tests indicate that the skid performance of a pavement surface may be adequately projected from the standard 40-mph test speed. Texture measurements on surface cores may be used to predict 40-mph skid numbers (SN) with a reasonable degree of accuracy. SN's, determined from texture measurements, exhibit a high degree of correlation with locked wheel skid values.

Analysis of over 450 accidents occurring at 75 locations included in the study indicate that the incidence of accidents increases on wet pavements when the SN is 40 or below. The costs of constructing and maintaining equipment capable of high speed skid testing are considerably higher than for equipment with a 40 mph capability. It has been recommended that future skid testing may be conducted at 40 mph, and a reasonable degree of confidence may be placed upon these tests to predict performance at higher test speeds.
Laboratory Investigation of the Effect of Particle Shape Characteristics and Gradation of Aggregates on the Skid Resistance of Asphalt Surface Mixtures
Authors: Huang EY , Ebrahimzadeh T
Published: March 2009

This paper presents the results of a laboratory study concerning the effects of the particle shape characteristics and gradation of aggregates on the skid resistance of asphalt surface mixtures, as determined by the British portable skid tester. Four coarse aggregates and two fine aggregates, representing both natural and crushed materials, were used. The particle shape characteristics of these materials were determined by the particle index test for positive, quantitative identification.

The aggregate materials were combined to form three different gradations, and mixed with the optimum content of an 85 to 100 penetration grade asphalt cement, as determined by the Marshall method of mixture design. Circular specimens 6 in. in diameter and 2 in. in thickness were used for the laboratory skid test. An accelerated polishing device similar to the one previously used by the investigators at Purdue University was employed to polish the surface of the test specimens. Skid resistance values were determined both before the specimens were polished and after different stages of polishing.

The results of this investigation show that, within the range of the variables studied, the antiskid properties of the experimental surface mixtures improved with increasing values of the particle index of the fine aggregate. The skid resistance was also affected significantly by the gradation, as represented by the composition index, of the aggregates. For the unpolished specimens, the British portable number (BPN) is shown to increase with increasing values of the composition index. The trend was reversed for the polished specimens in that the BPN was increased as the values of the composition index were decreased.
Heat Seal Thickness-Strength Correlations
Authors: Miller D
Published: March 2009

The relationships between the strength of a heat seal and the thickness of beads formed as a result of material flow from under the heat seal bar are continuous and often linear. Parabolic relationships resulting from increased thicknesses with decreased strengths are indicative of poor heat seals. Heat sealing temperatures and conditioning of the heat seals in boiling water affect the strength of the heat seals and the shape of the thickness—strength curves.
A Gravimetric Calibration Procedure for Modern Controls IRD-2 Infrared Water Vapor Diffusometer and Its Correlation with Results from ASTM Method E 96
Authors: Bornstein ND , Pike LeR
Published: March 2009

A brief description of the operating principles of the infrared IRD-2 Water Vapor Diffusometer and a detailed description of the gravimetric calibration procedure for it is given.

The calibration is achieved by absorbing and weighing the water transmitted by a film installed in the IRD-2 during a measured time interval. The procedure yielded four replicates near the 0.5 g/100 in.2, 24 h rate with 95 percent confidence limits of ±10 percent of the average rate.

The data allowed calculation of the background relative humidity in the IRD-2 dry chamber and the increase in relative humidity per cycle. The background humidity varies with the transmission rate of the film being measured, the dry air flow rate, and the efficiency of drying, but relative humidities near 0.2 percent are indicated with flow rates near 2 ft3/h and transmission rates near 0.5 g/100 in.2, 24 h. The increase in humidity per cycle may vary slightly from instrument to instrument. The instrument used in this study exhibited 0.45, 1.04, and 2.84 percent, respectively, on ranges 5, 4, and 3.

The round robin proved the calibration procedure was accurate and that the IRD-2 yields the same results as ASTM Method E 96 with improved precision.
Testing for Water Penetration
Authors: Sakhnovsky AA
Published: March 2009

The following general areas relating to water penetration testing of exterior windows, curtain walls, and doors are covered: (1) historical background (2) static pressure water leakage testing including test for water penetration of exterior windows, curtain walls, and doors by uniform static air pressure differential (E 331-70), (3) dynamic pressure water leakage testing, and (4) comparison and limitations of current static and dynamic test methods.
The Benefit of Forgetting Suicidal Ideation
Authors: Goldney Robert D. , Winefield Anthony H. , Winefield Helen R. , Saebel Judith
Published: March 2009

In a sample of young adult Australians, those who had had suicidal ideation but who did not acknowledge ever having had it when asked 4 years later, were experiencing better mental health, as demonstrated by significantly better functioning on a range of psychometric measures, than those who recalled it. These results are consistent with several recent reports and indicate that forgetting painful events such as suicidal ideation is an adaptive defense mechanism. This has implications in terms of therapy focusing on contemporaneous events and the future, rather than on the past.
White Public Opinion toward Undocumented Immigrants: Threat and Interpersonal Environment
Authors: Berg Justin Allen
Published: March 2009

Public opinion toward undocumented immigration is discussed in the popular media yet receives less attention in the social science literature. With data from the Bureau of Labor Statistics, the U.S. Census, and the General Social Survey, this study examines whites' immigration opinions in 1996 and 2004. The results indicate that in 1996 whites who lived in areas with greater unemployment were more likely to favor government action against undocumented immigrants, while in 2004 whites who lived in areas with more Latino residents were less likely to favor such action. Whites who are embedded in educated networks and networks with racially different contacts are more likely to be sympathetic toward undocumented immigrants. Older networks were associated with restrictionist opinions. The interpersonal environment appears to remain consequential for whites, even if they have no contact with undocumented immigrants. This study finds that opinion formation results from broad demographic and small interpersonal structures.
Pluralistic Ignorance among Assembled Peers
Authors: Grant Don , O'Neil Kathleen , Stephens Laura
Published: March 2009

Sociologists have long been interested in pluralistic ignorance—situations where a majority of individuals assume that most of their peers think differently than themselves when, in fact, their attitudes are similar. Recently, sociologists have suggested that pluralistic ignorance is especially likely to occur when peers are gathered together and may explain why group members often refrain from discussing their ultimate concerns with each other. However, researchers have not indicated what factors besides physical proximity might create pluralistic ignorance. Nor have they employed methods that can specify how causal factors combine to produce multiple routes to pluralistic ignorance. To remedy this situation, this article suggests several factors that may make others' opinions more or less transparent. It also proposes an analytical strategy that can identify which combinations of these factors are associated with misperceptions and illustrates how it might be applied. Implications of this study for future research are discussed.
From Fire and Brimstone to Property Values: The Changing Style of Arguments against Pornographic Industries, Atlanta, 1969–1997
Authors: Lindemann Danielle
Published: March 2009

Previous literature on moral reform has, with some notable exceptions, focused on the generation of moralistic sentiment, rather than the rhetoric through which it is deployed. This analysis adds an important coda to this literature by drawing further attention to the distinction between content and style when assessing moral-reform arguments. Examining every argument ( N = 540) made against a pornographic business in Atlanta, Georgia, from 1969 to 1997, as indexed by articles in the city's major newspaper, The Atlanta Journal-Constitution, it argues that the tendency to frame antipornography arguments in instrumental terms exists throughout the years of the study, but it becomes more pronounced over time. A compelling explanation for the shift in rhetoric is that individuals still valued morality in the 1980s and 1990s but framed their arguments in ways that maximized their efficacy, policy wise. Implications of these findings for broader sociological issues are discussed.
Acute Myelogenous Leukemia in Older Adults
Authors: Klepin Heidi D. , Balducci Lodovico
Published: March 2009

Learning Objectives

Outline the influences of tumor biology on clinical outcomes in older adults with acute myelogenous leukemia (AML). Enumerate patient-specific characteristics that influence clinical outcomes for older adults with AML. Formulate an algorithm to guide treatment decisions for older adults with newly-diagnosed AML.

This article is available for continuing medical education credit at CME.TheOncologist.com.
FDA Review of a Panitumumab (Vectibix™) Clinical Trial for First-Line Treatment of Metastatic Colorectal Cancer
Authors: Giusti Ruthann M. , Cohen Martin H. , Keegan Patricia , Pazdur Richard
Published: March 2009

On September 27, 2006, the U.S. Food and Drug Administration granted accelerated approval to panitumumab (Vectibix™; Amgen, Inc., Thousand Oaks, CA) for the treatment of patients with epidermal growth factor receptor–expressing, metastatic colorectal carcinoma with disease progression on or following fluoropyrimidine-, oxaliplatin-, and irinotecan-containing chemotherapy regimens. Accelerated approval was based on demonstration of a beneficial effect on progression-free survival (PFS).

The present submission summarizes a second clinical trial, to be included in the panitumumab package insert in June 2008, of chemotherapy and bevacizumab with and without panitumumab in the first-line treatment of patients with metastatic colorectal cancer. The study was closed when inferior PFS and greater toxicity were demonstrated at the time of the planned interim efficacy analysis.

Patients receiving panitumumab in combination with bevacizumab and chemotherapy experienced a higher incidence of death (9% versus 4%) and a higher risk for grade 3 and 4 toxicities than patients receiving bevacizumab and chemotherapy alone. The incidences of any Common Terminology Criteria for Adverse Events grade 3 and 4 adverse events (AEs) were 87% and 72% in the panitumumab and control groups, respectively. Grade 3 and 4 AEs occurring more commonly in panitumumab-treated patients included rash/acneiform dermatitis, diarrhea, dehydration, primarily resulting from diarrhea, hypokalemia, stomatitis/mucositis, and pulmonary embolism.

The addition of panitumumab to bevacizumab and chemotherapy for the first-line treatment of metastatic colorectal cancer was harmful when compared with bevacizumab and chemotherapy alone. The use of panitumumab in this setting cannot be recommended.
The ISI Classroom Observation System: Examining the Literacy Instruction Provided to Individual Students
Authors: Connor Carol McDonald , Morrison Frederick J. , Fishman Barry J. , Ponitz Claire Cameron , Glasney Stephanie , Underwood Phyllis S. , Piasta Shayne B. , Crowe Elizabeth Coyne , Schatschneider Christopher
Published: March 2009

The Individualizing Student Instruction (ISI) classroom observation and coding system is designed to provide a detailed picture of the classroom environment at the level of the individual student. Using a multidimensional conceptualization of the classroom environment, foundational elements (teacher warmth and responsiveness to students, classroom management) and instructional elements (teacher-child interactions, context, and content) are described. The authors have used the ISI system to document that children who share the same classroom have very different learning opportunities, that instruction occurs through interactions among teachers and students, and that the effect of this instruction depends on children’s language and literacy skills. This means that what is effective for one child may be ineffective for another with different skills. With improving classroom observation systems, the dynamics of the complex classroom environment as it affects student learning can be better understood.
Efficacy of lamina terminalis fenestration in reducing shunt-dependent hydrocephalus following aneurysmal subarachnoid hemorrhage: a systematic review
Authors: Komotar Ricardo J. , Hahn David K. , Kim Grace H. , Starke Robert M. , Garrett Matthew C. , Merkow Maxwell B. , Otten Marc L. , Sciacca Robert R. , Connolly E. Sander
Published: March 2009

Object

Chronic hydrocephalus requiring shunt placement is a common complication following aneurysmal subarachnoid hemorrhage (SAH). Controversy exists over whether microsurgical fenestration of the lamina terminalis during aneurysm surgery affords a reduction in the development of shunt-dependent hydrocephalus. To resolve this debate, the authors performed a systematic review and quantitative analysis of the literature to determine the efficacy of lamina terminalis fenestration in reducing aneurysmal SAH–associated shunt-dependent hydrocephalus.

Methods

A MEDLINE (1950–2007) database search was performed using the following keywords, singly and in combination: “ventriculoperitoneal shunt,” “hydrocephalus,” “subarachnoid hemorrhage,” “aneurysm,” “fenestration,” and “lamina terminalis.” Additional studies were manually singled out by scrutinizing references from identified manuscripts, major neurosurgical journals and texts, and personal files. A recent study from the authors' institution was also incorporated into the review. Data from included studies were analyzed using the chi-square analysis and Student t-test. The Cochran-Mantel-Haenszel test was used to compare overall incidence of shunt-dependent hydrocephalus.

Results

The literature search revealed 19 studies, but only 11 were included in this review, involving 1973 patients. The fenestrated and nonfenestrated cohorts (combined from the various studies) differed significantly with regard to patient sex, age, and clinical grade as well as aneurysm location (p = 0.0065, 0.0028, 0.0003, and 0.017, respectively). The overall incidence of shunt-dependent hydrocephalus in the fenestrated cohort was 10%, as compared with 14% in the nonfenestrated cohort (p = 0.089). The relative risk of shunt-dependent hydrocephalus in the fenestrated cohort was 0.88 (95% CI 0.62–1.24).

Conclusions

This systematic review revealed no significant association between lamina terminalis fenestration and a reduced incidence of shunt-dependent hydrocephalus. The interpretation of these results, however, is restricted by unmatched cohort differences as well as other inherent study limitations. Although the overall literature supports lamina terminalis fenestration, a number of authors have questioned the technique's benefits, thus rendering its efficacy in reducing shunt-dependent hydrocephalus unclear. A well-designed, multicenter, randomized controlled trial is needed to definitively address the efficacy of this microsurgical technique.
History of the genesis of detachable coils
Authors: Guglielmi Guido
Published: March 2009

The genesis of detachable coils and the background of this genesis are described in this article. To frame the beginning developmental stages of the discovery of detachable coils, the previous extravascular-intravascular and endovascular techniques are presented, as well as the development of the various delivery systems. The experimental studies, initial clinical application, and crucial moment of the conception of detachable coils are also reported.
Reduced limbic connections may contraindicate subgenual cingulate deep brain stimulation for intractable depression
Authors: McNab Jennifer A. , Voets Natalie L. , Jenkinson Ned , Squier Waney , Miller Karla L. , Goodwin Guy M. , Aziz Tipu Z.
Published: March 2009

In this study, the authors performed deep brain stimulation (DBS) of the subgenual anterior cingulate cortex (SACC) in a patient with a history of bipolar disorder. After a right thalamic stroke, intractable depression without mood elevation or a mixed state developed in this patient. He underwent bilateral SACC DBS and died 16 months afterwards. Anatomical connections were studied in this patient preoperatively and postmortem using diffusion tractography (DT). A comparison of in vivo and high resolution ex vivo connectivity patterns was performed as a measure of the utility of in vivo DT in presurgical planning for DBS. Diagnostic measures included neuropsychological testing, preoperative and ex vivo DT, and macroscopic neuropathological assessment. Post-DBS depression rating scores did not improve. In vivo and ex vivo DT revealed markedly reduced limbic projections from the thalamus and SACC to the amygdala in the right (stroke-affected) hemisphere. A highly selective right mediothalamic lesion was associated with the onset of refractory depression. Reduced amygdalar-thalamic and amygdalar-SACC connections could be a contraindication to DBS for depression. Correspondence between preoperative and higher resolution ex vivo DT supports the validity of DT as a presurgical planning tool for DBS.
Minimal-access technique for distal catheter insertion during ventricular peritoneal shunt procedures: a review of 100 cases
Authors: Ochalski Pawel G. , Horowitz Michael B. , Mintz Arlan H. , Hughes Steven J. , Okonkwo David O. , Kassam Amin B. , Watson Andrew R.
Published: March 2009

The authors report the safety and efficacy of using a percutaneous minimal-access insertion technique for distal shunt catheter placement in 100 cases.

From June 2007 to March 2008, they attempted 100 minimal-access insertions of distal shunt catheters in 91 patients who required ventriculoperitoneal shunting. Using the minimal-access approach, they avoided utilizing laparoscopic assistance or a mini-laparotomy in 91% of the cases. There were no bowel injuries or misplaced distal catheters. Additional outcomes in terms of operative times, cases that required conversion to open or laparoscopically assisted implantation, and infection rates are presented.

They conclude that intraperitoneal shunt catheter placement can be safely and effectively accomplished using a simplified percutaneous minimal-access insertion method that does not require direct laparoscopic visualization.
Pain with Punishment and The Negotiation of Childhood: An Ethnographic Analysis of Children's Rights Processes in Maasailand
Authors: Archambault Caroline
Published: March 2009

Children's rights activists contend that corporal punishment in schools is a form of child abuse which hinders children's learning. Yet most parents and teachers in Maasailand, Kenya consider corporal punishment, if properly employed, to be one of the most effective ways to instil the discipline necessary for children to learn and grow well. Responding to calls for a more empirical anthropology of rights, this article provides an ethnographic analysis of the practice of corporal punishment in domestic and primary school settings, exploring its pedagogical, developmental and social significance, and illuminating its role in the production and negotiation of identities and personhood.
Daniel Chambers Macreight FRCP, FLS (1799–1856), a little-known, innovative Irish botanist
Authors: NELSON E. CHARLES
Published: March 2009

Biographical information is provided for Daniel Chambers Macreight. He worked in Augustin-Pyramus de Candolle's herbarium at Geneva during the early 1830s, and later in the decade was prominent in medico-botanical circles in London. Macreight retired in 1840, due to ill-health, and moved to Jersey in the Channel Islands where he died. In 1837, he published an innovative Manual of the British flora which covered both native and cultivated plants. This flora contained two novel features: dichotomous keys were provided to assist students to identify plants, and the category subspecies was employed for taxa within the genera Rosa, Rubus and Salix.
Evidence of the former abundance of tigers (Panthera tigris) and leopards (Panthera pardus) from the taxidermy ledgers of Van Ingen & Van Ingen, Mysore
Authors: MORRIS P. A. , MORRIS M. J.
Published: March 2009

The business records of a major taxidermist in India reveal extraordinary numbers of large carnivores being processed, particularly in the 1930s. Leopards and tigers were predominant and also showed marked seasonal changes in the numbers passing through the factory in response to strong seasonality in the Indian climate affecting both animals and people. The number of jobs done each year reflects changing levels of activity in the business in response to the Second World War and later social and legislative pressures on big-game hunting. The meticulous records of Van Ingen & Van Ingen make it possible to trace individual specimens and establish whether or not they may be legally traded today within the provisions of the Convention on International Trade in Endangered Species (CITES).
Brimleyana(1979–1998): publication dates of issues and zoological names
Authors: POLY WILLIAM J.
Published: March 2009

The journal Brimleyana, published between 1979 and 1998 in 25 issues, contained a total of 84 new zoological names. The dates printed on the covers, footers of articles, and reprints conflict with actual publication dates in some instances, and as a result, some articles and taxonomic names have been cited with the incorrect year of publication. Discrepancies in year of publication affect nine names (two genus group, seven species group), and discrepancies in month of publication affect 21 names (one genus group, 20 species group). Therefore, the actual dates of publication, as established by mailing dates in the journal, are given for all issues of Brimleyana along with a complete list of new taxonomic names and new name combinations that appeared in the journal. Receipt date stamps on issues of Brimleyana from twelve libraries in the eastern United States were compared to the stated mailing dates, and receipt dates substantiate the validity of the mailing dates.
Cuckoos and their fosterers: uncovering details of Edward Blyth's field experiments
Authors: SEALY SPENCER G.
Published: March 2009

In a paper published in the Magazine of natural history in 1835, Edward Blyth (1810–1873) summarized information pertinent to the life history of the brood-parasitic common cuckoo (Cuculus canorus) in England, and its interactions with some of its foster species. He highlighted findings and ideas of other individuals and injected some of his own anecdotal observations into this account. Most interestingly, he alluded to experiments he had conducted or intended to conduct to elucidate the responses of hosts, as if parasitized by cuckoos. These experiments were among the first to be conducted in an area of research where today experimentation is common.
Thermodynamics of High Temperature Plasmas
Authors: Minardi Ettore
Published: March 2009

In this work we discuss how and to what extent the thermodynamic concepts and the thermodynamic formalism can be extended to the description of high temperature states of the plasma not necessarily associated with a Boltzmann distribution and with thermal equilibrium.The discussion is based on the “magnetic or electrostatic entropy concept”, an interpretative and predictive tool based on probability and information, defined in a suitably coarse-grained possibility space of all current density or of all electric charge density distributions under testable constraints, and whose variation properties are proven to be related under certain conditions to the equilibrium and the stability of the system. In the case of magnetic equilibrium the potentiality of the magnetic entropy concept is illustrated by comparing the predictions of the current density and pressure profiles with the observations in different tokamak machines and different tokamak regimes, as well as by showing how the equilibrium and the stability in devices as different as the reversed field pinch or the magnetic well are described by the variation properties of the same entropy functional applied to the different situations. In fact it emerges that the maximum of the entropy can be seen in these different cases as an optimization constraint for the minimum of the magnetic energy. The application of the entropy concept to the electrostatic processes shows in particular that the so-called reactive instabilities (non-dissipative, non-resonant instabilities with a marginal point) admit a neighboring state with higher entropy and are therefore of special relevance from the point of view of the physical evolution of the system. In this case the thermodynamic formalism allows the introduction of the concept of “thermodynamic fluctuations” of the macroscopic charge density and provides a method for the calculation of the “thermodynamic” fluctuation levels both on the stable as well as on the linearly unstable side of the marginal point. The paper discusses the relation between the variations of the entropy functional defined on statistical grounds and the motion of the underlying system of particles. It is found that the vanishing of the first variation of the entropy is connected, under certain assumptions, with the Hamilton’s principle, while the second variation is not directly related to the dynamics but is an expression of the fact that the entropy is a predictive tool based on probability and information.
Phosphotungstic Acid: An Efficient, Cost-effective and Recyclable Catalyst for the Synthesis of Polysubstituted Quinolines
Authors: Dabiri Minoo , Bashiribod Sahareh
Published: March 2009

Phosphotungstic acid (H3PW12O40) was used as an efficient and recyclable catalyst for the synthesis of polysubstituted quinolines through the Friedländer condensation of 2-aminoarylketone with carbonyl compounds, which was achieved by conventional heating under solvent-free conditions.
Scale Issues in Remote Sensing: A Review on Analysis, Processing and Modeling
Authors: Wu Hua , Li Zhao-Liang
Published: March 2009

With the development of quantitative remote sensing, scale issues have attracted more and more the attention of scientists. Research is now suffering from a severe scale discrepancy between data sources and the models used. Consequently, both data interpretation and model application become difficult due to these scale issues. Therefore, effectively scaling remotely sensed information at different scales has already become one of the most important research focuses of remote sensing. The aim of this paper is to demonstrate scale issues from the points of view of analysis, processing and modeling and to provide technical assistance when facing scale issues in remote sensing. The definition of scale and relevant terminologies are given in the first part of this paper. Then, the main causes of scale effects and the scaling effects on measurements, retrieval models and products are reviewed and discussed. Ways to describe the scale threshold and scale domain are briefly discussed. Finally, the general scaling methods, in particular up-scaling methods, are compared and summarized in detail.
The Selective Heating of Iron Nanoparticles in a Single‐Mode Microwave for the Patterned Growths of Carbon Nanofibers and Nanotubes
Authors: Druzhinina Tamara , Weltjens Wim , Hoeppener Stephanie , Schubert Ulrich S.
Published: March 2009

The fast and cheap synthesis of carbon nanotubes is addressed in a large number of recent publications. At the same time, microwave‐assisted synthesis has also gained interest. Besides the fact that reaction kinetics can be positively influenced by the use of microwave irradiation and advanced reaction conditions can be applied, absorption of microwave radiation depends on the material properties, thus resulting in a selective heating mechanism. The selective heating process allows for locally created temperatures high enough to promote the growth of carbon nanofibers and nanotubes on patterned iron catalyst layers. The resulting fibers are micrometers long, and can be synthesized in short time scales of a few minutes, yielding dense films of carbon fibers with uniform height. Here, the selective heating of surface bound iron nanoparticles is investigated in more detail, and experimental evidence for this effect is provided by utilizing a self‐assembled monolayer of n‐octadecyltrichlorosilane, which acts as a sensitive indicator for locally elevated temperatures. Special emphasis is placed on the development of an improved and controllable experimental setup that permits the safe and fast fabrication of the desired carbon objects.
Respiratory symptoms and lung function in foundry workers exposed to low molecular weight isocyanates
Authors: Löfstedt Håkan , Westberg Håkan , Seldén Anders I. , Lundholm Cecilia , Svartengren Magnus
Published: March 2009

Background

This study investigated the prevalence of ocular and respiratory symptoms and lung function in foundry workers exposed to isocyanic acid (ICA) and methyl isocyanate (MIC).

Methods

Foundry workers (n = 64) using the Hot Box binder technique and referents (n = 134) completed two questionnaires and a spirometry before and after a day shift. Findings were analyzed relating to exposure measurements of ICA, MIC, and formaldehyde.

Results

Exposed workers reported more frequently ocular irritation and coughing. Pre‐shift lung function was lower than predicted in both groups of workers, and was not associated with exposure duration. Decrease in lung function over shift was more pronounced in exposed workers, but this was not associated with quantitative measures of the exposures.

Conclusions

An increased prevalence of ocular and respiratory symptoms, as well as a small decrease in lung function over shift, was observed among exposed workers. No associations with exposure to monoisocyanates and formaldehyde were seen, thus suggesting that other irritants in the foundry environment might be the cause. The effects seemed to be small and not clinically relevant on an individual level. Further studies using a follow‐up design may be warranted. Am. J. Ind. Med. 52:455–463, 2009. © 2009 Wiley‐Liss, Inc.
5‐(Pyrrolidin‐2‐yl)tetrazol‐katalysierte Aldol‐ und Mannich‐Reaktionen: schnellere Reaktionen und niedrigere Katalysatorbeladung in einem Durchflussreaktor
Authors: Odedra Arjan , Seeberger Peter H.
Published: March 2009

Kontinuierliche Organokatalyse: Schnelle Aldol‐ und Mannich‐Reaktionen benötigen geringere Mengen an Katalysator, wenn sie in einem Mikroreaktor durchgeführt werden. Ein Prolintetrazol‐Derivat (5–10 Mol‐%) katalysiert asymmetrische Aldolreaktionen von aromatischen Aldehyden mit Ketonen in einem Mikroreaktor bei einer Reaktionstemperatur von 60 °C in Reaktionszeiten von 10–30 min (siehe Bild).

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A Preferred Disrotatory 4n Electron Möbius Aromatic Transition State for a Thermal Electrocyclic Reaction
Authors: Mauksch Michael , Tsogoeva Svetlana B.
Published: March 2009

Nicht verboten: Thermische 4n‐Elektronen‐Elektrocyclisierungen von Hückel‐Strukturen verlaufen über „erlaubte“ konrotatorische Pfade. Bei einer Möbius‐Topologie können dagegen die Woodward‐Hoffmann‐Regeln außer Kraft treten, sodass ein „verbotener“ disrotatorischer Pfad bevorzugt wird – dies zeigen theoretische Studien am Dodecahexaen 1, das über eine aromatische Heilbronner‐Möbius‐Übergangsstruktur 2 in das cyclische Polyen 3 übergeht.

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A General Approach to the Synthesis of Gold–Metal Sulfide Core–Shell and Heterostructures
Authors: Sun Zhenhua , Yang Zhi , Zhou Jianhua , Yeung Man Hau , Ni Weihai , Wu Hongkai , Wang Jianfang
Published: March 2009

Herz aus Gold: In Wasser dispergierbare Kern‐Schale‐Strukturen und ‐Heterostrukturen aus Goldnanokristallen verschiedener Form (Polyeder, Würfel und Stäbe) und vielfältigen Metallsulfid‐Halbleitern (ZnS, CdS, NiS, Ag2S und CuS) wurden ausgehend von Cetyltrimethylammoniumbromid‐beschichteten Goldnanokristallen und Metallthiobenzoaten hergestellt.

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Carbanion oder Amid? Elektronendichteuntersuchung am 2‐Picolyllithium‐Stammsystem
Authors: Ott Holger , Pieper Ursula , Leusser Dirk , Flierler Ulrike , Henn Julian , Stalke Dietmar
Published: March 2009

Die negative Ladungals Resultat der Deprotonierung der Methylgruppe wird über den 2‐Picolylring verteilt. Die aus der Elektronendichteverteilung abgeleiteten Bindungseigenschaften zeigen den Enamidcharakter von Picolyllithium (PicLi; Bild: Deformationsdichte von [2‐PicLi⋅PicH]2), wenn auch ein elektrophiler Angriff immer am deprotonierten C‐Atom erfolgt. Dies ist durch das elektrostatische Potential erklärbar, das ein Elektrophil zum nucleophilen Kohlenstoffatom dirigiert.

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Iron‐Catalyzed Oxidative Heterocoupling Between Aliphatic and Aromatic Organozinc Reagents: A Novel Pathway for Functionalized Aryl–Alkyl Cross‐Coupling Reactions
Authors: Cahiez Gérard , Foulgoc Laura , Moyeux Alban
Published: March 2009

Aryl‐Alkyl‐Kupplungsprodukte sind durch die eisenkatalysierte oxidative Heterokupplung von Organozinkreagentien unter milden Bedingungen zugänglich. Diese neuartige Reaktion erlaubt die Verwendung primärer wie sekundärer aliphatischer Diorganozinkreagentien als Kupplungspartner und toleriert funktionalisierte Aryl‐ und Alkylzinkreagentien.

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Supramolecular ABC Triblock Copolymers
Authors: Ambade Ashootosh V. , Yang Si Kyung , Weck Marcus
Published: March 2009

Just add it! Ruthenium initiators functionalized with hydrogen‐bonding sites were utilized in ring‐opening metathesis polymerization to prepare heterotelechelic polymers with hydrogen‐bonding and metal‐coordination units in a single step. Supramolecular ABC triblock copolymers were then self‐assembled in one pot by simply adding complementary telechelic polymers to a solution of the heterotelechelic polymer (see picture).

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Incorporation of Fe3O4 Nanoparticles into Organometallic Coordination Polymers by Nanoparticle Surface Modification
Authors: Kim Sang Bok , Cai Chen , Sun Shouheng , Sweigart Dwight A.
Published: March 2009

Surface‐modified Fe3O4 nanoparticles (NPs) can be obtained by substituting [(η5‐semiquinone)Mn(CO)3] for oleylamine surface protecting groups. The resulting NP can function as a nucleus or template to generate crystalline coordination polymers that contain superparamagnetic Fe3O4 NPs. Hybridized magnetic properties can be obtained by introducing paramagnetic metal nodes, such as Mn2+, into the polymers (see picture).

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A General Approach to the Synthesis of Gold–Metal Sulfide Core–Shell and Heterostructures
Authors: Sun Zhenhua , Yang Zhi , Zhou Jianhua , Yeung Man Hau , Ni Weihai , Wu Hongkai , Wang Jianfang
Published: March 2009

Cores and effect: Water‐dispersible core–shell structures and heterostructures incorporating gold nanocrystals of different shapes (polyhedra, cubes, and rods) and a variety of transition metal sulfide semiconductors (ZnS, CdS, NiS, Ag2S, and CuS) are synthesized using cetyltrimethylammonium bromide‐encapsulated gold nanocrystals and metal thiobenzoates as starting materials.

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Carbanion or Amide? First Charge Density Study of Parent 2‐Picolyllithium
Authors: Ott Holger , Pieper Ursula , Leusser Dirk , Flierler Ulrike , Henn Julian , Stalke Dietmar
Published: March 2009

The negative chargeoriginating from deprotonation of the methyl group is distributed over the 2‐picolyl ring. Bonding properties derived from the electron density distribution support the enamide character of picolyllithium (PicLi; the picture shows the deformation density of [2‐PicLi⋅PicH]2), but electrophilic attack occurs at the deprotonated C atom. This reactivity is rationalized by the electrostatic potential, which guides electrophiles towards the nucleophilic C atom.

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Iron‐Catalyzed Oxidative Heterocoupling Between Aliphatic and Aromatic Organozinc Reagents: A Novel Pathway for Functionalized Aryl–Alkyl Cross‐Coupling Reactions
Authors: Cahiez Gérard , Foulgoc Laura , Moyeux Alban
Published: March 2009

Aryl–alkyl cross‐coupling products are obtained by the iron‐catalyzed oxidative heterocoupling of organozinc reagents under mild conditions. This novel reaction pathway is versatile, allowing for the use of primary and secondary aliphatic diorganozinc reagents as coupling partners as well as tolerating functionalized aryl‐ and alkylzinc reagents.

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Exploring the Limits of Förster Theory for Energy Transfer at a Separation of 20 Å
Authors: Ziessel Raymond , Alamiry Mohammed A. H. , Elliott Kristopher J. , Harriman Anthony
Published: March 2009

Cutting the corner: An excellent agreement has been obtained between experimental and computed coulombic coupling matrix elements for donor–spacer–acceptor systems, which consist of a boron dipyrromethane donor and acceptor in various stages of protonation. This correlation occurs in spite of reservations about the validity of Förster theory being applied to intramolecular electronic energy transfer (ET) over short (e.g., 20 Å) distances (see picture).

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Metagenomics: Concept, methodology, ecological inference and recent advances
Authors: Singh Jagtar , Behal Arvind , Singla Neha , Joshi Amit , Birbian Niti , Singh Sukhdeep , Bali Vandana , Batra Navneet
Published: March 2009

Microorganisms constitute two third of the Earth's biological diversity. As many as 99% of the microorganisms present in certain environments cannot be cultured by standard techniques. Culture‐independent methods are required to understand the genetic diversity, population structure and ecological roles of the majority of organisms. Metagenomics is the genomic analysis of microorganisms by direct extraction and cloning of DNA from their natural environment. Protocols have been developed to capture unexplored microbial diversity to overcome the existing barriers in estimation of diversity. New screening methods have been designed to select specific functional genes within metagenomic libraries to detect novel biocatalysts as well as bioactive molecules applicable to mankind. To study the complete gene or operon clusters, various vectors including cosmid, fosmid or bacterial artificial chromosomes are being developed. Bioinformatics tools and databases have added much to the study of microbial diversity. This review describes the various methodologies and tools developed to understand the biology of uncultured microbes including bacteria, archaea and viruses through metagenomic analysis.
High‐throughput system for determining dissolution kinetics of inclusion bodies
Authors: Dürauer Astrid , Mayer Sabrina , Sprinzl Wolfgang , Jungbauer Alois , Hahn Rainer
Published: March 2009

Efficient solubilization is a crucial step during inclusion body processing and dissolving conditions were usually empirically established. Here we describe a new methodology for rapid screening of solubilization conditions and evaluation of dissolution kinetics in microtiter plates. Increase of protein in solution over time was directly related to decrease of turbidity measured by absorbance at 600 nm. Dissolution kinetics of inclusion bodies were described by a first‐order reaction kinetics, which was used for drug dissolution modeling. Reaction constants were in the range of 0.01–0.03 s–1 for buffer conditions providing sufficient solubilization power. This method is not limited to the screening of optimal buffer conditions for solubilization and can be applied for studying other parameters involved in the solubility of IBs, such as pI of the protein, influence of fermentation conditions, influence of initial protein concentration, and more.
SCL‐LCL‐PHA copolymer production by a local isolate,Pseudomonas aeruginosaMTCC 7925
Authors: Singh Akhilesh Kumar , Mallick Nirupama
Published: March 2009

A five‐level‐four‐factor central composite rotary design (CCRD) was employed in combination with response surface methodology (RSM) to optimize the process variables for the production of a novel copolymer consisting of short‐chain‐length (SCL) and long‐chain‐length (LCL) PHA units,i.e., P(3HB‐3HV‐3HHD‐3HOD) copolymer inPseudomonas aeruginosaMTCC 7925. The four variables involved in this study were ethanol, glucose, ammonium nitrate (NH4NO3), and potassium dihydrogen phosphate (KH2PO4). A second‐order polynomial equation was obtained by multiple regression analysis using RSM. The statistical analyses of the results showed that all the four variables had significant impact on the copolymer yield. The model predicted a maximum yield of 81.1% of dry cell weight (dcw) on setting the concentrations of ethanol and glucose at 1.5 and 1.1%, and KH2PO4and NH4NO3at 2.79 and 1.86 g/L, respectively. Verification of the predicted value resulted into a yield of 77.6% (dcw). This novel copolymer exhibited comparable material properties with polypropylene (PP) and low density polyethylene (LDPE), thus advocating its potential applications in various fields.