bluuebunny/crossref_metadata_2025 huggingface dataset:
Thiol disulfide exchange reactions in human serum albumin: the apparent paradox of the redox transitions of Cys34
Authors: Bocedi Alessio , Cattani Giada , Stella Lorenzo , Massoud Renato , Ricci Giorgio
Published: July 2018

Human serum albumin (HSA) is characterized by 17 disulfides and by only one unpaired cysteine (Cys34), which can be free in the reduced albumin or linked as a mixed disulfide with cysteine, or in minor amount with other natural thiols, in the oxidized albumin. In healthy subjects, the level of the oxidized form is about 35%, but it rises up to 70% after oxidative insults or in patients with kidney diseases. Oxidized albumin is therefore considered a short‐term biomarker of oxidative stress as its level may increase or decrease under appropriate redox inputs in discrete temporal spans. This paper defines, for the first time, the kinetic properties of reduced and oxidized Cys34 of HSA in their reactions with natural disulfides and thiols. Kinetic constants support the evidence that the Cys34 redox oscillations observed in vivo are mainly due to the interaction with cysteine and cystine without the involvement of any enzymatic support. This study gives also a plausible explanation for the absence of involvement of the 17 disulfides naturally present in HSA in these redox transitions. This inert behavior toward cysteine is marginally due to solvent accessibility or flexibility factors of these bonds but mainly to their strong thermodynamic stability, which is caused essentially by a proximity effect. A similar mechanism is likely at play in the many proteins that maintain disulfide bridges in a reducing medium like the cytosol.
One‐step bioconversion of hemicellulose polymers to rhamnolipids with Cellvibrio japonicus: A proof‐of‐concept for a potential host strain in future bioeconomy
Authors: Horlamus Felix , Wittgens Andreas , Noll Philipp , Michler Jan , Müller Inga , Weggenmann Fabiola , Oellig Claudia , Rosenau Frank , Henkel Marius , Hausmann Rudolf
Published: July 2018

The purpose of this study was to evaluate Cellvibrio japonicus as a potential host strain for one‐step bioconversion of hemicellulose polymers to value‐added products. C. japonicus could be cultivated on all main lignocellulose monosaccharides as well as xylan polymers as a sole carbon source. This is particularly interesting as most industrially relevant bacteria are neither able to depolymerize wood polymers nor metabolize most hemicellulose monosaccharides. As a result, lignocellulose raw materials typically have to be degraded employing additional processes while the complete conversion of all lignocellulose sugars remains a challenge. Exemplary for a value‐added product, a one‐step conversion of xylan polymers to mono‐rhamnolipid biosurfactants with C. japonicus after transformation with the plasmid pSynPro8oT carrying the genes rhlAB was demonstrated. As achieved product yields in this one‐step bioconversion process are comparably low, many challenges remain to be overcome for application on an industrial scale. Nonetheless, this study provides a first step in the search for establishing a future host strain for bioeconomy, which will ideally be used for bioconversion of lignocellulose polymers with as little exhaustive pretreatment as possible.
Piecing together suffrage internationalism: Place, space, and connected histories of Australasian women's activism
Authors: Keating James
Published: July 2018

Over the past 20 years, suffrage historians have sought to reimagine their field—traditionally tethered to the nation—as an international one. The Australasian suffragists, who strove to overcome their perceived isolation by exchanging print, personnel, and ideas across borders, seem perfect candidates for such revisionist treatment. However, despite the invigorating push to destabilise the nation, which has rewired much of Australian and New Zealand historiography, the suffragists remain ensconced in national frames. Revisiting the rich Australasian scholarship on women, mobility, and cross‐border organisation, this article discusses the political and intellectual barriers that have impeded attempts to reconstruct suffrage internationalism. Yet documenting the suffragists' cross‐border interactions requires more than replacing monolithic national histories with revised internationalist versions. Instead, responding to debates about the digitally driven rise of connected histories, this article argues that historians should piece together suffrage internationalism as it existed in specific places—recovering often messy assemblages of transnational individuals, groups, and organisations. Such an approach will both illuminate colonial women's place in the networks that bound the fin‐de‐siècle world and provide a fresh perspective on the international women's movement.
Labour market turnover in Latin America: How intensive is it and to what extent does it differ across countries?
Authors: BECCARIA Luis , MAURIZIO Roxana
Published: July 2018

The study of labour market turnover is particularly significant in Latin America, which is characterized by marked economic cycles and limited social protection coverage. This article estimates the intensity of transitions from employment in six countries in Latin America in the new millennium and decomposes the differences observed, furthermore evaluating the employment destinations of workers making such transitions. The countries under analysis show very different turnover rates, which are mostly explained by a dissimilar incidence of informal and temporary employment. In all cases, a large share of job exits imply transitions to precarious jobs or unemployment.
Validation of self‐reported influenza vaccination in the current and prior season
Authors: King Jennifer P. , McLean Huong Q. , Belongia Edward A.
Published: July 2018

Self‐reported influenza vaccination is generally accurate for the current season, but the accuracy of self‐report for vaccination in prior seasons is largely unknown. This study evaluated the accuracy of self‐report for current and prior season influenza vaccination among patients with medically attended acute respiratory illness enrolled in a study of influenza vaccine effectiveness during the 2014‐15 influenza season. It demonstrates there is a greater potential for exposure misclassification when prior season vaccinations are ascertained by self‐report. Percent agreement between self‐report and final status was high for both current and prior season vaccination: 97.7% and 93.2%, respectively.
Influenza forecast optimization when using different surveillance data types and geographic scale
Authors: Morita Haruka , Kramer Sarah , Heaney Alexandra , Gil Harold , Shaman Jeffrey
Published: July 2018

Background

Advance warning of influenza incidence levels from skillful forecasts could help public health officials and healthcare providers implement more timely preparedness and intervention measures to combat outbreaks. Compared to influenza predictions generated at regional and national levels, those generated at finer scales could offer greater value in determining locally appropriate measures; however, to date, the various influenza surveillance data that are collected by state and county departments of health have not been well utilized in influenza prediction.

Objectives

To assess whether an influenza forecast model system can be optimized to generate accurate forecasts using novel surveillance data streams.

Methods

Here, we generate retrospective influenza forecasts with a dynamic, compartmental model‐inference system using surveillance data for influenza‐like illness (ILI), laboratory‐confirmed cases, and pneumonia and influenza mortality at state and county levels. We evaluate how specification of 3 system inputs—scaling, observational error variance (OEV), and filter divergence (lambda)—affects forecast accuracy.

Results

In retrospective forecasts, and across data types, there were no clear optimal combinations for the 3 system inputs; however, scaling was most critical to forecast accuracy, whereas OEV and lambda were not.

Conclusions

Forecasts using new data streams should be tested to determine an appropriate scaling value using historical data and analyzed for forecast accuracy.
Fabrication of ZrB2 ceramics by reactive hot pressing of ZrB and B
Authors: Liu Limeng , Hou Zhaoping , Zhao Yanwei , Geng Guihong , Wang Yujin
Published: July 2018

Zirconium diboride (ZrB2) ceramics were prepared by reactive hot pressing of ZrB+B powder mixture. Formation of a transient liquid due to eutectic reaction of ZrB2+Zr→Leu(ZrB2+Zr) at 1661°C following peritectic decomposition of 2ZrB=ZrB2+Zr at 1250°C during heating up of the ZrB+B mixture facilitated densification. The liquid phase was subsequently eliminated via reaction of B with Zr in the eutectic liquid Leu(ZrB2+Zr) to result in a dense ZrB2 ceramic. Full density was reached after reactive hot pressing at 1900°C under 30 MPa for 1 h. The ZrB2 ceramic had a refined microstructure consisting of grains of <1.5 μm in size and relatively good Vickers hardness (21 ± 2 GPa) and flexural strength (595 ± 63 MPa).
Improvement in hydration resistance of CaO granules by addition of Zr(OH)4and Al(OH)3
Authors: Wei Yaowu , Zhang Tao , Zhang Qi , Han Bingqiang , Li Nan
Published: July 2018

Improving the hydration resistance of CaO aggregates is the key to successful application of lime‐based refractories in metallurgical industry. Additive Zr(OH)4and Al(OH)3were introduced in the preparation of CaO granules using granulation equipment and calcination method in this study. The results showed that the hydration resistance of CaO granules was improved significantly, especially for granules with 0.6 wt.% Zr(OH)4and 0.9 wt.% Al(OH)3, respectively. The shell of CaO granules was relatively dense after calcination and the volume of open pores of CaO granules decreased from 3.56 × 10−2to 1.80 × 10−2cm3/g when additive was introduced. Zr(OH)4and Al(OH)3have the opposite effect on the closed porosity of CaO granules, the closed porosity of CaO granules was decreased with Zr(OH)4addition, but increased with Al(OH)3addition.
Spatial, temporal and individual‐based differences in nest‐site visits and subsequent reproductive success in wild great tits
Authors: Firth Josh A. , Verhelst Brecht L. , Crates Ross A. , Garroway Colin J. , Sheldon Ben C.
Published: July 2018

The behaviour of individual birds before and during the breeding period may be an important factor determining reproductive success. One commonly observed behaviour during the breeding period in many species is the visitation of multiple potential breeding sites. Much research has attempted to determine the function and consequences of this behaviour, but traditionally studies have been limited to not examining individual‐level behaviour, or only considering a small number of individuals. We used automated recording of RFID‐tagged birds visiting nestboxes to study a population of 80 great tits (Parus major) making > 3500 daily visits across 74 breeding sites, to quantify the frequency, spatial patterning, and temporal occurrence of this behaviour from the pre‐breeding period onwards. We argue that 1) the tight spatial clustering of visits, 2) juveniles visiting more sites than adults, and 3) males (but not females) continuing to visit other sites even as egg laying at their own nest occurs, indicate that territoriality and extra‐pair mating may underpin visitation behaviour. Further, we find that spatial clustering of female visits relates to increased clutch size and fledging success, while frequently visiting a preferred nesting site increases the likelihood of obtaining a breeding site but reduces subsequent reproductive output for both sexes. Our study offers new insight into the mechanisms potentially driving breeding site visitation behaviour, and demonstrates its relationship to individual fitness. We suggest that although visitation behaviour may be related to different components of fitness, future work should use experiments to fully assess the causal factors and effects of visitation behaviour.
What Can Environmental Sequences Tell Us About the Distribution of Low‐Rank Taxa? The Case of Euplotes (Ciliophora, Spirotrichea), Including a Description of Euplotes enigma sp. nov.
Authors: Boscaro Vittorio , Syberg‐Olsen Mitchell J. , Irwin Nicholas A. T. , del Campo Javier , Keeling Patrick J.
Published: July 2018

Environmental sequences have become a major source of information. High‐throughput sequencing (HTS) surveys have been used to infer biogeographic patterns and distribution of broad taxa of protists. This approach is, however, more questionable for addressing low‐rank (less inclusive) taxa such as species and genera, because of the increased chance of errors in identification due to blurry taxonomic boundaries, low sequence divergence, or sequencing errors. The specious ciliate genus Euplotes partially escapes these limitations. It is a ubiquitous, monophyletic taxon, clearly differentiated from related genera, and with a relatively well‐developed internal systematics. It has also been the focus of several ecological studies. We present an update on Euplotes biogeography, taking into consideration for the first time environmental sequences, both traditional (Sanger) and HTS. We inferred a comprehensive small subunit rRNA gene phylogeny of the genus including a newly described marine species, Euplotes enigma, characterized by a unique question mark‐shaped macronucleus. We then added available environmental sequences to the tree, mapping associated metadata. The resulting scenario conflicts on many accounts with previously held views, suggesting, for example, that a large diversity of anaerobic Euplotes species exist, and that marine representatives of mainly freshwater lineages (and vice‐versa) might be more common than previously thought.
Implant Placement under Existing Removable Dental Prostheses and the Effect on Follow‐Up and Prosthetic Maintenance
Authors: Marotti Juliana , Gatzweiler Bodo , Wolfart Mona , Sasse Martin , Kern Matthias , Wolfart Stefan
Published: July 2018

Purpose

The aim of this prospective clinical study was to compare the maintenance interventions required for solely implant‐retained overdentures (I‐OD) with that of overdentures retained by a combination of telescopic crowns and implants (T/I‐OD).

Materials and methods

The participants in this study were 22 patients who initially presented either with a removable complete denture (n = 11) or with an overdenture retained by 1 to 2 telescopic crowns on natural teeth (n = 11). Subsequently, the total number of abutments was increased to 5 to 6 (maxilla) or 4 to 5 (mandible) by placing implants in strategically advantageous regions, generating two distinct groups: I‐OD and T/I‐OD. Ball attachments were connected to the implants and integrated into the existing denture. The maintenance aspects were analyzed according to the type of treatment (preventive, biological, and technical) and to the severity of treatment (minimal, moderate, and extensive).

Results

During a mean observation time of 6.5 years, the tooth survival rate was 89% (T/I‐OD) and the implant survival rate 100% (both groups). The survival rates of the overdentures ranged from 90.9% (I‐OD) to 100% (T/I‐OD). A mean number of 0.6 (I‐ODs) and 2.0 (T/I‐OD) treatments were performed for biological reasons; and 8.2 (I‐ODs) and 9.6 (T/I‐OD) for technical reasons, per patient, during the observation time. From biological aspects, significantly more extensive maintenance was found to be necessary in the T/I‐OD group than in the I‐OD group.

Conclusions

The therapeutic concept of implant placement under existing prostheses was promising when performed in indicated cases.
Remote spectral–compositional analysis of basalt mineralogy at Hansteen‐Billy, Moon
Authors: Chauhan Mamta , Bhattacharya Satadru , Pathak Sumit , Chauhan Prakash
Published: July 2018

The Hansteen‐Billy region of the Moon lying toward the southwest edge of Oceanus Procellarum is characterized by emplacement of three different aged basaltic units viz. INm, Im, and Em. The present study primarily utilizes high‐resolution Chandrayaan‐I, Moon Mineralogy Mapper (M3) data clipped at ~2.5 μm for mineral analysis of these units. The spectra of all the three regions show two prominent absorption bands. Spectral analysis characterizes the earliest INm basalts as low‐Ca pyroxenes with large band area ratios (BAR) and nearly similar B‐I and B‐II strength. The Em and Im basalts are Ca and high‐Ca pyroxenes, respectively, with relatively less BAR values and more B‐II/B‐I strength. The relative content of their spectra after olivine correction appears to be dominated by pyroxene. The obtained results have been used for estimation of the compositional characteristics of pyroxenes from laboratory‐based calibration equations. The pyroxene composition for INm basalts indicates their pigeonitic affinity, whereas the Im and Em basalts is close to augite. The estimated temperature of crystallization suggests that basalts in this region evolved at higher temperature and are preserved in a metastable condition due to quick cooling. Furthermore, the area is characterized by increase in concentration of both the Fe and Ti with age as assessed from Clementine mineral map. The obtained results have been discussed in relation with source of the magma.
Genesis of the South Zhuguang Uranium Ore Field, South China: Pb Isotopic Compositions and Mineralization Ages
Authors: Zhang Chuang , Cai Yuqi , Dong Qian , Xu Hao
Published: July 2018

U–Pb isotopic analyses indicate that ores from the South Zhuguang uranium ore field, south China, have high common (non‐radiogenic) Pb contents, with variable and relatively radiogenic initial Pb contents. The U–Pb isochron method was used to date these ores, with plots of208Pb/204Pb and207Pb/204Pb versus206Pb/204Pb being used to identify sample suites with similar initial Pb isotopic ratios and to normalize variable initial Pb isotopic ratios. The resulting U–Pb isochrons indicate two substages of uranium mineralization at ~57 and 52 Ma, with a later hydrothermal reformation at ~49 Ma, which homogenized Pb isotopic compositions. Initial Pb isotopic systematics indicate that the ore‐forming fluid was characterized by high206Pb/204Pb and207Pb/204Pb ratios and low208Pb/204Pb ratios, suggesting that the ore‐forming fluid was sourced from Cretaceous–Paleogene red‐bed basins, rather than from magma or the mantle, with consideration of mineralization ages.
Shrouding Add‐On Information: An Experimental Study*
Authors: Normann Hans‐Theo , Wenzel Tobias
Published: July 2018

We explore how increased competition affects firms’ obfuscation strategies in a laboratory experiment. Firms sell a base good and an add‐on product. Besides choosing the base‐good price, sellers take an action that mimics the effects of shrouding the add‐on product. Shrouding is an equilibrium but an unshrouding equilibrium coexists. In our experiment, more competition matters, in that only duopolistic markets are frequently shrouded whereas four‐firm markets are not. With repeated interaction, shrouding rates do not increase. However, the opportunities to shroud facilitate tacit collusion on the base‐good price for the duopolies: the unshrouding equilibrium serves as a credible punishment if deviations occur.
When Family Replaced Friendship: Mobile Communication and Network Change in Kenya
Authors: Garretson Oliver , Fan Jiabin , Mbatia Paul N. , Miller Paige , Shrum Wesley
Published: July 2018

Mobile devices have spread throughout the developing world at a rate unparalleled by other communications technologies. Yet surprisingly, little is known about their impact on social networks. This study analyzes three waves of pooled survey data in Nairobi (2002, 2007, 2013). We focus on the size, composition, and location of important personal relationships—that is, “core networks.” Networks of close ties have nearly doubled for urban Kenyans, as network composition shifted toward kin and away from friends. Indeed, friendship decreased from over one‐third to less than a fourth of close ties, while family ties grew from one‐third to nearly half. The geographic distribution of networks has become broader, moving away from local ties and toward national (but not international) relationships. Finally, the pace of change declined as mobile devices became embedded in daily life.
Popular, rejected, neglected, controversial, or average: Do young children of different sociometric groups differ in their level of oral communicative competence?
Authors: van der Wilt Femke , van der Veen Chiel , van Kruistum Claudia , van Oers Bert
Published: July 2018

Children’s sociometric status refers to their position within the peer group and plays a major role in their future social development. It is therefore important to investigate factors that are related to it. To date, little attention has been paid to the potential role of oral communicative competence. The present study investigated sociometric group differences in the level of oral communicative competence in a sample of N = 570 children in early childhood education. Sociometric status was measured using a nomination procedure. Based on peer nominations, children were categorized into five sociometric groups: (1) popular (generally well‐liked), (2) rejected (generally disliked), (3) neglected (low visibility and neither liked nor disliked), (4) controversial (high visibility and both liked and disliked), and (5) average (at or about the mean on both likability and visibility). Children’s level of oral communicative competence was assessed with the Nijmegen Test for Pragmatics. Results of multi‐level analyses revealed significant sociometric group differences: children who were rejected or neglected by their peers exhibited lower levels of oral communicative competence than average children. Based on these findings, teachers in early childhood education are encouraged to pay more explicit attention to the promotion of their pupils’ oral communicative competence.
Using Shiny to illustrate the probability density function concept
Authors: Miranda Freire Sergio
Published: July 2018

The transition from the probability mass function for discrete random variables to the probability density function for continuous random variables is not straightforward, especially to students from the health and social sciences. An R Shiny application was created to assist the learning process of probability density function.
Metabolic syndrome in women with polycystic ovary syndrome
Authors: Chandrasekaran Swaramya , Sagili Haritha
Published: July 2018

Key content

The risk factors for metabolic syndrome include central obesity, hypertension, atherogenic dyslipidaemia and insulin resistance. Metabolic syndrome affects 33% of women with polycystic ovary syndrome (PCOS) and has been less well researched than other features such as infertility, anovulation and hirsutism.

Consequences of metabolic syndrome include cardiovascular disease, type II diabetes, cancer, sleep apnoea and psychological problems.

Cardiometabolic risk screening involves obtaining data on smoking history, weight, body mass index, waist circumference, blood pressure, lipid profile, and taking an oral glucose tolerance test.

Management of metabolic syndrome should focus on risk factors and individual components. Lifestyle modification is the only recommended intervention at present.

Learning objectives

To know the pathogenesis and consequences of metabolic syndrome in women with PCOS.

To understand the diagnostic criteria and screening procedures for metabolic syndrome.

To learn how to manage metabolic syndrome in women with PCOS.

Ethical issues

Potential preventive long‐term medication raises two issues: duration of therapy and unwarranted adverse effects.

Advocating bariatric surgery without availability of robust evidence in PCOS women.
How Did the Titanic Sink?
Authors: Deitz Dan
Published: July 2018

This article elucidates the reasons behind the Titanic sink. The recent engineering evidence suggests that the unsinkable ship, Titanic, experienced a hull failure at the surface and broke into pieces before it went down. Although all the officers testified that the ship sank intact, some survivors and crew testified to a hull failure at the surface. Even during the American and British inquiries into the disaster, few questions focused on the structural aspects of the ship. Despite survivors’ testimonies, it was concluded that the ship sank intact. A full-ship model was graphically constructed, employing a modern approach similar to that used for US Navy destroyers and cruisers today. Loadings for the model were developed based on one flooding scenario from the paper, “The Sinking of the Titanic,” by Chris Hackett and John C. Bedford. The demise of the mighty Titanic was swift, sure, and terrible. The engineering marvel that heralded the beginning of the age of technology also displayed, all too clearly, its vulnerability and limits—as well as the need for prudence and safety.
FEA Makes Airframes Safer
Authors: Deitz Dan
Published: July 2018

This article focuses on data gathered during the controlled destruction of a Boeing 747 airliner are helping engineers to identify ways of strengthening aircraft to make them less vulnerable to an internal explosion. Even though it may not help engineers understand the specific events in the crash of Flight 800, a controlled explosion of a Boeing 747 by the British Defence Evaluation Research Agency (DERA) , based in London, could point the way to controlling the damage from airliner explosions in the future. The 747-1 00 had been an attraction at the Bruntingthorpe Aerodrome in Leicestershire, England, before it was purchased by the British Ministry of Defence and the US Federal Aviation Administration (FAA). Initially, the meshes were too coarse for the dynamic analyses to be used in the test, so engineers refined them accordingly in the blast area. Using new features in MSC/DYTRAN 4, the team will model the airframe as a series of layers, which is representative of the lining concepts to be tested.
Merging CAD with IT
Authors: Carrabine Laura
Published: July 2018

This article highlights the various processes involved in shipbuilding such as design, production planning, material sourcing, and outfitting. Since the program’s inception, Newport News Shipbuilding (NNS), has leveraged its computer-aided- design, -manufacturing, and –engineering (CAD/CAM/CAE) system and IT infrastructure to successfully revitalize its engineering environment and remain profitable in a rapidly changing marketplace. NNS engineers perform all of their ship product modeling using a proprietary program called VIVID, a design system that enables users to concurrently design structures in a multidisciplinary environment. As part of the continuing effort to develop its IT infrastructure and automate production processes, NNS has invested $60 million in upgrading its engineering design systems and automating manufacturing facilities with advanced material-handling systems, robotic cutting work cells, and robotic welding work cells. NNS is also transitioning its product-modeling systems from a Unix workstation environment to Windows NT platforms based on Microsoft’s ActiveX and COM technologies.
Foil Air Bearings Cleared to Land
Authors: Agrawal Giri L.
Published: July 2018

This article explores use of foil air bearings in land-based turbomachinery. A machine with foil air bearings is more reliable than one with rolling element bearings because it requires fewer parts to support the rotative assembly and needs no lubrication. Foil air bearings can handle severe environmental conditions such as the ingestion of sand and dust. A reversed pilot design at the cooling flow inlet prevents large particles from entering the bearing's flow path, and smaller particles are continually flushed out of the bearing by the cooling flow. Many applications of foil air/gas bearings other than air cycle machines have been built and successfully tested, but nothing appears to be currently in production. Foil bearings have strong potential in several applications. Among these are small general aviation gas turbine engines; oil-free cryogenic turboexpanders for gas separation plants; auxiliary power units for various aerospace and ground vehicles; and, taking advantage of automated manufacturing methods, automotive gas turbine engines, vapor-cycle centrifugal compressors, and commercial air/gas compressors.
Metallic Glasses Bulk Up
Authors: Ashley Steven
Published: July 2018

Vitreloy, a metallic–glass alloy of zirconium and beryllium from Amorphous Technologies International (ATI) in Laguna Niquel, CA, is extensively being used in golf clubs. Liquidmetal golf-club heads are fabricated from an amorphous metal alloy that has excellent rebound and vibration-absorbing properties. Research indicates that the prized physical properties of metallic glasses arise in large part from their lack of grain boundaries, which can serve as points of weakness. Liquidmetal putters have a ‘soft’ feel when striking the ball, which the makers claim provides players with improved touch on putting greens. The elevated strength-to-weight ratios exhibited by Liquidmetal alloys make the metallic glasses promising for a range of high-performance applications. Sports enthusiasts may also soon find bulk metallic glasses like Vitreloy in other high-end sporting goods such as tennis rackets, baseball bats, bicycle frames, hunting bows, and even edged tools such as axes. ATl management stated that high-performance sporting goods are only a first step in the market; the new family of materials could also be promising for other, more serious applications.
Tapping into Know-How
Authors: Thilmany Jean
Published: July 2018

Engineers from all disciplines are using computerized libraries to get quick answers to critical questions. General Electric Appliances in Louisville, KY, is helping its engineers gain more plastics knowhow, has put in place an information software program. The software is Know-How from C-Mold, which is also based in Louisville. Engineers can search for pertinent information about a plastics design problem they may be working on and get answers at their desktop. The Invention Machine product, called Knowledgist, reads and understands digital documents stored in its base. The software uses what the company calls semantic processing technology that scans and analyzes a document. Engineers at GE Appliances use a Web-based computerized library to find answers to questions about plastics molding design and manufacture. The software exists on the Internet and is accessible via a Web browser.
Adjusting the Boiler Code
Authors: Canonico Domenic A.
Published: July 2018

Technological advances have made it possible to reduce the material design factor in the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. Today solid-state circuitry is the only power source used in welding equipment. The use of solid-state circuitry has brought a great deal of stability to the electrical characteristics of the arc, and this in turn has resulted in weldments with considerably fewer imperfections. The US government sponsored a study to determine the causes of the failures and to evaluate the metallurgical and other factors that contributed to the fractures. This project studied samples from more than 100 ships, in which serious failures had occurred. This and other concurrent studies around the world led to an understanding of the role of notch toughness in preventing failures in pressure boundary components. The conservativeness of Section I and Section VIII, Division 1, continues to be significant. The change from 4 to 3.5 in the material design factor will not compromise safety. The denominator for determining an allowable stress based on yield strength remains the same, 1.5. The probability of failure of a pressure-containing component due to an overstress condition is small. The change from 4 to 3.5 has had very little impact on that conservative material design factor.
Induction for the Birds
Authors: Wolcott Barbara
Published: July 2018

NASA and the US Navy are exploring magnetic fields in search of quicker, smoother, and cheaper launches. A Navy program based in Lakehurst, NJ, wants to learn if magnetic propulsion is the answer. It awarded two contracts in December for what it calls the electromagnetic aircraft launch system. One award went to Northrop Grumman of Sunnyvale, California, and the other to General Atomics in San Diego. NASA is in the second year of a three-year program to investigate magnetic launch technology. The systems under study by NASA combine linear induction, to accelerate the vehicle to launch speed, with magnetic levitation, using opposing magnetic fields to suspend the vehicle above its track. The Navy’s catapult program does not require magnetic levitation. The US Maglev Technology Assessment, written jointly by the Corps of Engineers and the Department of Transportation, points out that since ‘magnetic drag is small at high speeds, only aerodynamic drag consumes appreciable energy.
Trail Blazer into Space
Authors: Wick Frank
Published: July 2018

This article reviews that from the Cold War to Voyager, the work of Robert Goddard has received much recognition. Independently, Goddard started conceiving and designing a variety of air and space vehicles, and analyzing methods for propulsion and control. In 1903, Wilbur and Orville Wright had achieved powered flight with the three-axis control they had invented, but the flying machine was extremely difficult to manage. In 1907, while he was still an undergraduate, Goddard studied the dynamics of the Wright Flyer, and designed a gyroscope-based stabilizer for automatic control. His attempts to procure government funding were rejected by a United States military that did not recognize any value of rockets beyond the possibility of assistance at takeoff for aircraft. Rockets increasingly are supporting the marvels of our post-Cold War information revolution. The satellite-based Global Positioning System has brought the most sophisticated navigation system into the personal automobile. Within the century, Robert Goddard’s vision and life’s work begat far more than he could have imagined.
Easing the Strain
Authors: Hartung Glen
Published: July 2018

This article focuses on the finite element analysis (FEA) that is a key ingredient in keeping a popular theme park ride up and running. Long before the ride entered service, Universal called in GLENCO Engineering Inc., to perform finite element modeling and analysis in order to evaluate the primary structural components of the Spider-Man ride vehicle cabin. The FEA initiated to increase the stiffness of the cabin floor also identified a location where the peak strains were higher than the values determined in the hand calculations and associated strain gauge testing. The FEA of the Spider-Man cabin structure significantly improved the design of the composite floor. Strains measured at locations selected without the benefit of FEA produced a misleading assessment of the design in its first prototype. FEA, however, identified peak strains at a location and direction that were not intuitively obvious to the engineers. The results were confirmed with dynamic strain measurements—verifying not only magnitude but also directions of the principal strains. The finite element model was a valuable tool that enabled the floor design to be precisely refined in one of the iterations.
Keeping it Cool
Authors: Valenti Michael
Published: July 2018

This article provides details of various aspects of air cooling technologies that can give gas turbines a boost. Air inlet cooling raises gas turbine efficiency, which is proportional to the mass flow of air fed into the turbine. The higher the mass flow, the greater the amount of electricity produced from the gas burned. Researchers at Mee Industries conduct laser scattering studies of their company’s fogging nozzles to determine if the nozzles project properly sized droplets for cooling. The goal for turbine air cooling systems is to reduce the temperature of inlet air from the dry bulb temperature, the ambient temperature, to the wet bulb temperature. The Turbidek evaporative cooling system designed by Munters Corp. of Fort Myers, Florida, is often retrofit to turbines, typically installed in front of pre-filters that remove particulates from inlet air. Turbine Air Systems designs standard chillers to improve the performance of the General Electric LM6000 and F-class gas turbines during the hottest weather.
Pushing Productivity
Authors: Thilmany Jean
Published: July 2018

This article reviews computer-aided engineering software that is used to boost productivity ranges from computer-aided design (CAD) systems to product data management and visualization systems. MacDon Industries used a Solid Edge product to merge CAD and product data management (PDM) systems to give engineers easy access to already created designs. MacDon tracks its tens of thousands of part designs by use of Solid Edge so engineers do not have to spend considerable time searching for the designs. Bayside Automation of Canonsburg, Pennsylvania, which makes automated assembly systems on which fuse boxes, valves, and the like are made, has discovered another area where technology—in this case, simulation software—can cut costs and increase productivity. CAD and PDM software from Alibre of Richardson, Texas, help the supplier and manufacturer pass translated design information back and forth quickly.
Speaking Different Languages
Authors: Thilmany Jean
Published: July 2018

This article illustrates the importance of interoperability between computer-aided design (CAD), computer-aided manufacturing (CAM), and computer-aided engineering (CAE) software. Interoperability is an intricate concept, rife with accusation and blame-laying, and dependent on the unseen algorithms and mathematical equations that drive the lines and geometries CAD users see on screen. At the Daratech 2000 summit, a panel of technology users and technology vendors worked together to draft what was called a symposium communique that challenged suppliers to cooperate more with one another to move toward interoperability. The communique calls the interoperability issue one of the most troublesome aspects of CAD, CAM, and CAE usage. PTC in Waltham, MA, has released Associate Topology Bus, a tool that thy company says helps engineers share data between systems by allowing them to exchange geometry as well as what the company calls design-intent, between systems. Autodesk of San Rafael, California, offers interoperable features as what it calls DWG linking between its AutoCAD software and its 3D Studio Viz, a system used by architects. Its Mechanical Desktop software can read printed circuit board data in intermediate data format (IDF) and convert it to AutoCAD objects suitable for further mechanical design and manufacturing applications.
The Language of Interaction
Authors: Karnopp Dean , Margolis Donald
Published: July 2018

This article discusses various features and applications of bond graphs in mechanical electrical industry. A ‘bond’ represents the energy exchange among subsystems. The product of two variables, effort and flow, represents this power. With bond graphs, all subsystems can be represented with a mere nine elements. The physics of some elements require that the list expands to include multiport versions of energy dissipation, storage, and transfer. When subsystems composed of sensors and actuators are connected, an overall system model evolves. This overall model represents the dynamics of the entire system. With bond graphs, causality is indicated by a perpendicular stroke at the end of a bond. Thus, assigning causality is a straightforward task. Bond graphs dealt with mixed energy domain systems as well. Analogies among various systems, such as equivalent electrical circuits for mechanical vibratory systems, were never complete because each field had unique features. Bond graphs use analogous power and energy variables in all energy domains, but allow the distinctive features of the separate fields to be represented.
Electronic Spelunkers
Authors: Thilmany Jean
Published: July 2018

This article highlights that virtual reality is expected to be the next big thing in electronic world. For engineers, this means that within the next decade designing on a flat computer screen will no longer be the norm. Expect to at least touch and manipulate a virtual part as you design and probably even walk inside and around a projection of the design in progress. Mechanical engineers who work at large or even at not-so-large companies have probably seen a manifestation of this. The Cyber Edge study found the three visual simulation markets with the most growth currently are virtual prototyping, design evaluation, and technology architecture. The technologies are now more and more commonly deployed at engineering companies of all sizes. As usual, large companies, such as automakers, can afford to be ahead of the curve on the coming technological trends, and virtual reality is no exception.
Drip, drip, drip...
Authors: Chalmers Peggy
Published: July 2018

This article highlights that growing environmental and safety concerns, abetted by technology changes, are fueling a resurgence of water as a power transfer medium in hydraulics, where for years oil has been the fluid of choice. The shift has been gradual, but steady, after starting five years ago or more in Europe. In North America, progress has been slower. The traditional water hydraulics markets, steel and aluminum mills and auto assembly plants, have seen a little or no change. Water hydraulics is very attractive because it can be used for more than one purpose. It can turn a wheel, lift a load, or push something and, at the same time, provide fire suppression for an individual machine or an entire space. It can provide humidification to eliminate static electricity in a printing plant, or it can run a food processing plant during the day and become part of the clean-in-place system at night.
More Motor Muscle
Authors: Valenti Michael
Published: July 2018

This article reviews that material and design improvements convert more electrical energy into mechanical power. According to the Department of Energy, electric motors account for two-thirds of the energy consumed by US industries, including chemicals, general manufacturing, mining, and utilities. More than 1.2 million integral electrical motors are sold each year, 10–15% of them high-efficiency motors, according to the National Electrical Manufacturers Association (NEMA), based in Rosslyn, VA. Greenville Tube Corp., based in Greenville, PA, is a subsidiary of Chart Industries Inc. in Cleveland. Greenville Tube’s 100,000-square-foot plant in Clarksville, AR, made a name for itself by quickly producing stainless steel tubing of specific size and type to reduce costly downtime caused by equipment failure. The Clarksville plant cold draws approximately one million feet of stainless steel tubing each month for use in automotive, aerospace, food processing, and medical equipment, pharmaceutical and petrochemical applications.
Saving Ears or Fuel
Authors: DeGaspari John
Published: July 2018

This article discusses that freight carriers have their own sets of issues. Faced with the same economic pressures as long-haul trucks on the nation’s highways, freight trains are getting heavier and heavier, increasing axle loads and the forces that bear on the tracks. The challenges of minimizing wear and energy consumption are becoming more demanding for railroads. Managing friction between the wheel and the rail is an increasingly tough job, but a critical one for avoiding a host of performance problems and high costs. Friction modifiers are coatings that provide a controlled coefficient of friction at the contact point between the wheel tread and the top of the rail. The key point is control, which makes it possible to achieve a specific friction range. This is the main difference between friction modifiers and ordinary grease. CSX Corp. has begun tests of the two systems in cooperation with the Transportation Technology Center. The center has installed instrumentation in a section of track, and CSX has bought five TracGlide systems and five locomotive-mounted Lubriquip systems that will apply Kelsan’s friction modifier.
Old School Ties
Authors: Wolcott Barbara
Published: July 2018

This article focuses on when practicing engineers return to the university, theory gets a reality check. The idea of schools and businesses working together to approach problem solving is well over 100 years old and has roots in the industrial revolution and the reconstruction of the South following the devastation of the Civil War. Partnership with industry illustrates the importance to future engineers of learning to cross pollinate their experience because the days of clear separation in engineering-mechanical from electrical, for example-are gone. Systems demand diverse technology. Automobile emissions control, for example, requires a working knowledge of chemistry, and mechanical engineers need to cooperate with professionals from other disciplines on a regular basis. Business partnerships with education try to ensure that this commingling of theory and practical values is part of basic preparation rather than a skill that must be learned in the workplace. Business also contributes to advanced curriculum, helping to continuously develop and improve the experience at school by giving students technically meaningful projects that industry actually needs.
More Than One Force of Nature
Authors: Thilmany Jean
Published: July 2018

This article reviews how engineers can examine multiple influences in only one simulation by using multiphysics technologies. Engineers simulate the model more realistically rather than see the result of one analysis and then the result of another as an unrelated case. Engineers can simulate, say, the combined electrical and mechanical behavior of an overall system as a part of one virtual prototype. Multiphysics, then, can be looked at as a series of finite element and computational fluid flow analyses (FEA/CFD) layered on top of each other to describe the whole and real-life working conditions of the part. FEA solves simultaneous algebraic equations and lets engineers simulate a wide variety of physical phenomena, including laminar flow, turbulent flow, impact, and nonlinear geometric or material simulations. CFD describes how a fluid will flow through a system. With the development of increasingly easier-to-use multiphysics programs, it is likely that more engineering firms will be turning toward these full-scale analyses packages in the near future.
Lightning Plays the Stadium
Authors: Cheng Andrew
Published: July 2018

This article highlights proper electrical grounding when roof structures have no fixed connections to the ground. The roof’s mechanization designers, at Uni-Systems Inc. in Minneapolis, decided to study the effects of an electrical impulse through a machine-bearing surface. Uni-Systems had been confident that implementing conventional copper shunt grounding to bypass the nonconductive points would solve one problem. However, once the path was shunted, current was routed to the wheels and bearings. Testing would be required to identify the effects of a lightning strike in a greased bearing. Uni-Systems returned to Neetrac to test a new assembly, consisting of a plain spherical bearing with fibriloid liner, an axle, and spacers, installed to an eye bracket machined to house the bearing and a clevis bracket. The tests showed that with shunt wires installed, a current with up to 20,000 amperes passing through the hinge has no adverse effect—either short or long term—on the hinge bearing. Thus, the hinge bearing assembly can be used as a part of the grounding path for lightning protection.