bluuebunny/crossref_metadata_2025 huggingface dataset:
A nursing shortage – a prospect of global and local policies
Authors: Marć M. , Bartosiewicz A. , Burzyńska J. , Chmiel Z. , Januszewicz P.
Published: July 2018

Aim

The article addresses selected determinants of the nursing shortage in Poland and other countries in the face of employee ageing.

Background

Global demographic changes have led to a systematic increase in the elderly population and a decreasing number of births, which have impacted health policy and healthcare systems in various countries. Both processes necessitate transitions in global health care. Nursing care, which has faced a human resources crisis, is a strategic area within this context.

Sources of evidence

This study is based on national listings and strategic documents for nursing policy in Poland, including Increasing average age of nurses and midwives prepared by the Polish Main Council of Nurses and Midwives, the incorporation of big data, international reports and a literature review on nursing and healthcare challenges.

Discussion/Conclusions

This paper argues that the causes of the nursing shortage are multifaceted with no single global or local measure of its nature. An overview of the problem indicates ineffective planning and use of available nursing resources, poor recruitment or an undersupply of a new staff, and global demographic conditions. The overview highlights the fact that nursing shortages have reached a critical point for healthcare services on both the local and global levels.

Conclusions for nursing and health policy

The general recommendations for nursing policy include the need to prepare and implement national social security agendas into services provided by nurses. Such a programme would include general issues: improving working and employment conditions, implementing mechanisms regulating salary and providing the possibility of lifelong learning with the incorporation of mobile and technological innovations as a sustainable solution.
Definition and Measurement of Sexual Orientation
Authors: Gonsiorek John C. , Sell Randall L. , Weinrich James D.
Published: July 2018

Measurement and definition of sexual orientations have increasingly become a central focus in both research design and public policy debates. This paper reviews major methods, and their theoretical underpinnings, for the definition and measurement of sexual orientations, highlighting their limitations and pitfalls, both practical and conceptual. The increasing politicization of this area is discussed and cautioned against. Recommendations, both general and geared toward measurement concerns with adolescent populations, are made. A specific measurement strategy, which can be utilized at a number of different levels, is detailed.
Papiospp. Colon microbiome and its link to obesity in pregnancy
Authors: Li XuanJi , Rensing Christopher , Taylor William L. , Costelle Caitlin , Brejnrod Asker Daniel , Ferry Robert J. , Higgins Paul B. , Folli Franco , Kottapalli Kameswara Rao , Hubbard Gene B. , Dick Edward J. , Yooseph Shibu , Nelson Karen E. , Schlabritz‐Loutsevitch Natalia
Published: July 2018

Introduction

Gut microbial communities are critical players in the pathogenesis of obesity. Pregnancy is associated with increased bacterial load and changes in gut bacterial diversity. Sparse data exist regarding composition of gut microbial communities in obesity combined with pregnancy.

Material and methods

Banked tissues were collected under sterile conditions during necropsy, from three non‐obese (nOb) and four obese (Ob) near‐term pregnant baboons. Sequences were assigned taxonomy using the Ribosomal Database Project classifier. Microbiome abundance and its difference between distinct groups were assessed by a nonparametric test.

Results

Three families predominated in both the nOb and Ob colonic microbiome:Prevotellaceae(25.98% and 32.71% respectively),Ruminococcaceae(12.96% and 7.48%), andLachnospiraceae(8.78% and 11.74%). Seven families of the colon microbiome displayed differences between Ob and nOb groups.

Conclusion

Changes in gut microbiome in pregnant obese animals open the venue for dietary manipulation in pregnancy.
Therapeutic value of stimulating the nitrate‐nitrite‐nitric oxide pathway to attenuate oxidative stress and restore nitric oxide bioavailability in cardiorenal disease
Authors: Carlstrom M. , Montenegro M. F.
Published: July 2018

Cardiovascular disorders including hypertension and associated renal disease are major health problems affecting more than 1.5 billion people worldwide. Apart from nonmodifiable factors such as ageing, family history and gender, both sedentary lifestyle and unhealthy dietary habits are considered as major risk factors. The disorders are interrelated suggesting common pathological pathways. Mechanistically, oxidative stress and compromised function of the nitric oxide synthase (NOS) system leading to endothelial dysfunction and reduction in nitric oxide (NO) bioavailability have been widely implicated and associated with development and progression of disease. New strategies that correct this redox imbalance and increase NO bioactivity may have major clinical implications. The inorganic anions, nitrate and nitrite, are endogenously formed by oxidization of NOS‐derived NO, but there are also high amounts of nitrate in our daily diet. In this regard, accumulated evidence over the past two decades demonstrates that these anions can be recycled back to NO and other bioactive nitrogen oxides, thus offering an attractive alternative strategy for therapeutic exploitation. In this review, we describe how dietary stimulation of the nitrate–nitrite–NO pathway affects cardiovascular and renal functions in health and disease via modulation of oxidative stress and NO bioavailability. Clinical studies addressing potential effects on the renal system are still limited, but blood pressure‐lowering effects of nitrate supplementation have been demonstrated in healthy and hypertensive subjects as well as in patients with chronic kidney disease. However, larger clinical studies are warranted to reveal whether chronic nitrate treatment can slow‐down the progression of cardiorenal disease and associated complications.
A Randomized Clinical Trial Comparing Zirconia and Metal‐Ceramic Three‐Unit Posterior Fixed Partial Dentures: A 5‐Year Follow‐Up
Authors: Suarez Maria J. , Perez Cristina , Pelaez Jesus , Lopez‐Suarez Carlos , Gonzalo Esther
Published: July 2018

Purpose

To compare the survival, success rates, and biological/technical complications of posterior metal‐ceramic (MC) and zirconia fixed partial dentures (FPDs).

Materials and Methods

A total of 40 patients requiring 40 posterior FPDs were randomly assigned to receive 20 zirconia and 20 MC restorations. The restorations were examined 1 week (baseline) and 1, 3, and 5 years after the end of treatment. Technical and biological outcomes were compared. Data were statistically analyzed using the Wilcoxon signed‐rank and Mann‐Whitney U tests.

Results

The survival rates of both groups were 100%, and the success rates were 80% (zirconia) and 100% (MC). No biological complications were observed. Minor chipping was found in 20% of the zirconia restorations. No differences in periodontal parameters were observed between groups.

Conclusions

Zirconia FPDs exhibited the same survival rate (100%) as MC FPDs after 5 years; however, the success rate was 80%, because an increased rate of chipping was observed in zirconia restorations.
The effects of group‐based Laughter Yoga interventions on mental health in adults: A systematic review
Authors: Bressington Daniel , Yu Clare , Wong Wandy , Ng Tsz C. , Chien Wai Tong
Published: July 2018

Accessible summary

What is known on the subject?

Laughter yoga is claimed to promote mental health and has become increasingly popular worldwide.

There has been no systematic review of laughter yoga intervention studies and thus evidence of its effects on mental health is unclear.

What the paper adds to existing knowledge?

Laughter Yoga interventions improved depressive symptoms in two studies over the short term.

There is a lack of good quality evidence to show that laughter yoga is more effective than other group‐based interventions in improving mental health.

What are the implications for practice?

Well‐conducted and clearly reported trials of laughter yoga are needed before the intervention can be considered as an evidence‐based intervention to improve mental health.

Introduction

Laughter Yoga is claimed to promote mental health and is increasingly popular worldwide. Despite its popularity, there has been no systematic review of Laughter Yoga intervention studies and thus evidence of its effects on mental health is unclear.

Aim

This review aimed to critically evaluate the effects of group‐based Laughter Yoga on improving mental health in adults.

Method

We conducted a systematic review of experimental studies (published from 1995 to 2017). Study quality was assessed, the effect sizes for individual mental health outcomes were calculated and all reviewed studies were narratively synthesized.

Results

Six experimental studies with inconsistent results were included in this review. The most promising effect of Laughter Yoga is the improvement of depressive symptoms, indicating significant medium‐large effect sizes in two studies over the short term. The overall level of evidence was weak due to poor study quality and risks of bias.

Discussion

Laughter Yoga shows potential, but currently there is insufficient evidence to support its effectiveness in improving mental health when compared to other group‐based interventions.

Implications for practice

This review highlights the need to conduct rigorous trials of laughter yoga before the intervention can be considered as an evidence‐based intervention to improve mental health.
Vegetation patterns along agricultural land abandonment in the Balkans
Authors: Zakkak Sylvia , Radovic Andeja , Panitsa Maria , Vassilev Kiril , Shuka Lulëzim , Kuttner Michael , Schindler Stefan , Kati Vassiliki
Published: July 2018

Question

What are the woody vegetation encroachment patterns after agricultural land abandonment? Focusing on two parameters, woody plant species richness and vertical vegetation heterogeneity (number of different vegetation strata and their relative cover) we investigated: (a) the effect of forest encroachment following land abandonment; (b) the comparative importance of forest encroachment vis‐a‐vis topographic and climatic parameters, and finally; (c) the ecological importance of eight land‐cover types encountered in abandoned agricultural landscapes.

Location

The Balkan Peninsula (Albania, Bulgaria, Croatia, Greece).

Methods

We set up a standard methodology for 1 × 1 km site selection (70 sites) and data collection within 497 plots, along a well‐defined forest encroachment gradient that reflects land abandonment in terms of woody vegetation cover.

Results

The pattern that emerged was neither clear nor common for the Balkan region, regarding the effect of forest encroachment on the woody plant species richness in young forests, formed from 20 to 50 years after land abandonment. However, at national level, species diversity was significantly affected by elevation (Bulgaria and Croatia) and temperature (Croatia), with lower and cooler areas being richer. Elevation was of great importance in determining vertical vegetation heterogeneity. Woodlots, broad‐leaved forests, hedges and shrublands held the highest woody species richness in comparison to the more open land‐cover types, and vertical vegetation heterogeneity was higher in open forests and woodlots.

Conclusions

We expect the expansion of broad‐leaved forests following land abandonment to enhance woody species richness. However, other land‐cover types that were found to be important for woody plants should be maintained. As woody plants play a key role in supporting overall biodiversity, by providing suitable habitat for many species, we consider the preservation of a mosaic of patches of different land‐cover types essential for the conservation of both plant and animal species diversity. Young forests should be preserved at intermediate stages of succession, through intermediate disturbance activities, including medium intensity grazing and the enhancement of wild ungulates.
Integrative approaches to guide conservation decisions: Using genomics to define conservation units and functional corridors
Authors: Barbosa Soraia , Mestre Frederico , White Thomas A. , Paupério Joana , Alves Paulo C. , Searle Jeremy B.
Published: July 2018

Climate change and increasing habitat loss greatly impact species survival, requiring range shifts, phenotypic plasticity and/or evolutionary change for long‐term persistence, which may not readily occur unaided in threatened species. Therefore, defining conservation actions requires a detailed assessment of evolutionary factors. Existing genetic diversity needs to be thoroughly evaluated and spatially mapped to define conservation units (CUs) in an evolutionary context, and we address that here. We also propose a multidisciplinary approach to determine corridors and functional connectivity between CUs by including genetic diversity in the modelling while controlling for isolation by distance and phylogeographic history. We evaluate our approach on a Near Threatened Iberian endemic rodent by analysing genotyping‐by‐sequencing (GBS) genomic data from 107 Cabrera voles (Microtus cabrerae), screening the entire species distribution to define categories of CUs and their connectivity: We defined six management units (MUs) which can be grouped into four evolutionarily significant units (ESUs) and three (putatively) adaptive units (AUs). We demonstrate that the three different categories of CU can be objectively defined using genomic data, and their characteristics and connectivity can inform conservation decision‐making. In particular, we show that connectivity of the Cabrera vole is very limited in eastern Iberia and that the pre‐Pyrenean and part of the Betic geographic nuclei contribute the most to the species genetic diversity. We argue that a multidisciplinary framework for CU definition is essential and that this framework needs a strong evolutionary basis.
Immunoglobulin‐like domains of the cargo proteins are essential for protein stability during secretion by the type IX secretion system
Authors: Sato Keiko , Kakuda Shinji , Yukitake Hideharu , Kondo Yoshio , Shoji Mikio , Takebe Katsuki , Narita Yuka , Naito Mariko , Nakane Daisuke , Abiko Yoshimitsu , Hiratsuka Koichi , Suzuki Mamoru , Nakayama Koji
Published: July 2018

The periodontal pathogen Porphyromonas gingivalis secretes many potent virulence factors using the type IX secretion system (T9SS). T9SS cargo proteins that have been structurally determined by X‐ray crystallography are composed of a signal peptide, functional domain(s), an immunoglobulin (Ig)‐like domain and a C‐terminal domain. Role of the Ig‐like domains of cargo proteins in the T9SS has not been elucidated. Gingipain proteases, which are cargo proteins of the T9SS, were degraded when their Ig‐like domains were lacking or truncated. The degradation was dependent on the activity of a quality control factor, HtrA protease. Another T9SS cargo protein, HBP35, which has a thioredoxin domain as a functional domain, was analyzed by X‐ray crystallography, revealing that HBP35 has an Ig‐like domain after the thioredoxin domain and that the hydrophobic regions of the thioredoxin domain and the Ig‐like domain face each other. HBP35 with substitution of hydrophobic amino acids in the Ig‐like domain was degraded depending on HtrA. These results suggest that the Ig‐like domain mediates stability of the cargo proteins in the T9SS.
Inferring distributional shifts of epidemiologically important North and Central American sandflies from Pleistocene to future scenarios
Authors: Moo‐Llanes D. A. , Pech‐May A. , Ibarra‐Cerdeña C. N. , Rebollar‐Téllez E. A. , Ramsey J. M.
Published: July 2018

Nine sandfly species (Diptera: Psychodidae) are suspected or proven vectors of Leishmania spp. in the North and Central America region. The ecological niches for these nine species were modelled in three time periods and the overlaps for all time periods of the geographic predictions (G space), and of ecological dimensions using pairwise comparisons of equivalent niches (E space), were calculated. Two Nearctic, six Neotropical and one species in both bioregions occupied a reduced number of distribution areas. The ecological niche projections for most sandfly species other than Lutzomyia shannoni and Lutzomyia ovallesi have not expanded significantly since the Pleistocene. Only three species increase significantly to 2050, whereas all others remain stable. Lutzomyia longipalpis shared a similar ecological niche with more species than any other, although both L. longipalpis and Lutzomyia olmeca olmeca had conserved distributions over time. Climate change, at both regional and local levels, will play a significant role in the temporal and spatial distributions of sandfly species.
Widespread ancient whole‐genome duplications in Malpighiales coincide with Eocene global climatic upheaval
Authors: Cai Liming , Xi Zhenxiang , Amorim André M. , Sugumaran M. , Rest Joshua S. , Liu Liang , Davis Charles C.
Published: July 2018

Whole‐genome duplications (WGDs) are widespread and prevalent in vascular plants and frequently coincide with major episodes of global and climatic upheaval, including the mass extinction at the Cretaceous–Tertiary boundary (c. 65 Ma) and during more recent periods of global aridification in the Miocene (c. 10–5 Ma). Here, we exploreWGDs in the diverse flowering plant clade Malpighiales.

Using transcriptomes and complete genomes from 42 species, we applied a multipronged phylogenomic pipeline to identify, locate, and determine the age ofWGDs in Malpighiales using three means of inference: distributions of synonymous substitutions per synonymous site (Ks) among paralogs, phylogenomic (gene tree) reconciliation, and a likelihood‐based gene‐count method.

We conservatively identify 22 ancientWGDs, widely distributed across Malpighiales subclades. Importantly, these events are clustered around the Eocene–Paleocene transition (c. 54 Ma), during which time the planet was warmer and wetter than any period in the Cenozoic.

These results establish that the Eocene Climatic Optimum likely represents a previously unrecognized period of prolificWGDs in plants, and lends further support to the hypothesis that polyploidization promotes adaptation and enhances plant survival during episodes of global change, especially for tropical organisms like Malpighiales, which have tight thermal tolerances.
Topographic approach to the long‐term effect of solar exposure on facial skin of Korean automobile commuters
Authors: Kim D. Y. , Ahn T. M. , Kye Y. C. , Seo S. H.
Published: July 2018

Background

Car drivers are generally exposed to direct sunlight during commuting hours, which may lead to irreversible skin damage; however, topographical analysis for different facial areas has not been reported.

Methods

Facial areas were divided topographically into 11 areas based on esthetic units. We performed a preliminary study to identify the delivery pattern of solar energy on the face in the car during commuting time; subsequently, 15 drivers aged above 50 years were enrolled. Statistical evaluation was performed to investigate topographical differences between the left and right sides of the face and between sexes.

Results

The left side of the face was different from the right side for L*, a*, and b* on the infraorbital area and L* and b* on the temporal area. Differences were found for L*, a*, or b* between sexes on the central and right face, but not on the left. The left side had more severe hyperpigmentation and wrinkles than the right on average.

Conclusion

The left facial area, especially the infraorbital and temporal areas, of Korean automobile commuters was vulnerable to sun damage. Therefore, automobile drivers should care about these areas while driving to prevent long‐term effect from chronic solar damage.
Laparoscopic myomectomy: a review of alternatives, techniques and controversies
Authors: Bryant‐Smith Alison , Holland Tom
Published: July 2018

Key content

Laparoscopic myomectomy (LM) is considered to be particularly technically difficult because it requires advanced intracorporeal suturing.

LM involves a wide continuum of surgical difficulty; surgeons must be self‐aware of both their skill‐set and their limitations when selecting appropriate patients for this surgery.

The greater a woman's age, the less there is to be gained by preserving her future fertility and the greater the risk of leiomyosarcoma. Hysterectomy should be considered when fertility is no longer desired or feasible.

When asking a patient to give consent for LM, the following risks must be mentioned: parasitic myomata and disseminated peritoneal leiomyomatosis, and potentially upstaging an occult malignancy (such as leiomyosarcoma).

There is currently no preoperative test to definitively exclude leiomyosarcoma.

Learning objectives

To understand the importance of thorough preoperative counselling before LM, including the potential risks of intracorporeal morcellation.

To understand the key steps involved in performing an LM.

Ethical issues

The potential benefits of a laparoscopic versus open myomectomy must be considered; for example, does the worsened prognosis in women with unsuspected leiomyosarcoma, inadvertently morcellated, outweigh adverse outcomes in patients who undergo open myomectomy?

Since in‐bag morcellation remains an experimental technique, its possible benefits and long‐term outcomes are yet to be established.
The FT/FD‐dependent initiation of flowering under long‐day conditions in the day‐neutral species Nicotiana tabacum originates from the facultative short‐day ancestor Nicotiana tomentosiformis
Authors: Beinecke Farina A. , Grundmann Lena , Wiedmann David R. , Schmidt Florentin J. , Caesar Andrea S. , Zimmermann Marius , Lahme Michael , Twyman Richard M. , Prüfer Dirk , Noll Gundula A.
Published: July 2018

Photoperiod is an important external stimulus governing the precise timing of the floral transition in plants. Members of the FLOWERING LOCUS T (FT)‐like clade of phosphatidylethanolamine‐binding proteins induce this developmental process in numerous species by forming regulatory protein complexes with FD‐like bZIP transcription factors. We identified several thus far unknown FT‐like and FD‐like genes in the genus Nicotiana and found that, even in the day‐neutral species Nicotiana tabacum, floral initiation requires the photoperiod‐dependent expression of several FT‐like genes. Furthermore, floral promotion under long‐day (LD) and short‐day (SD) conditions is mediated by an FT‐like protein (NtFT5) that originates from the genome of the paternal, facultative SD ancestor Nicotiana tomentosiformis. In contrast, its ortholog of the maternal LD ancestor Nicotiana sylvestris is not present in the genome of N. tabacum cv. SR1. Expression profiling in N. tabacum and its ancestors confirmed the relevance of these FT and FD orthologs in the context of polyploidization. We also found that floral inhibition by tobacco FT‐like proteins is not restricted to SD conditions, highlighting the coincident expression of tobacco FT‐like genes encoding floral activators and floral inhibitors. Multicolor bimolecular fluorescence complementation analysis revealed the preferential formation of FT/FD complexes that promote rather than inhibit flowering, which in concert with the regulation of NtFT and NtFD expression could explain how floral promotion overcomes floral repression during the floral transition in tobacco.
Patterns of Cultural Inclusion and Exclusion in American Society: The Case of Chaldean Americans
Authors: Ben Hafsa Lanouar
Published: July 2018

This study aims to shed light on a community for long positioned as Arab and/or Muslim but still in search of a sense of belonging that promotes its ancestral heritage and at the same time reinforces bonds of solidarity among its members. It investigates the rhetoric around the Detroit-based Chaldean diaspora, not merely as case in point, but also because this is where the bulk of Chaldean Americans are concentrated. While it retraces their pathway from the homeland (Iraq) up through their establishment in the United States, it essentially explores the debate surrounding the group’s identity formation. Principally, it seeks to scrutinize patterns of continuity and change operating within the Chaldean microcosm, namely to demonstrate that the construct “ethnic identity” is more than a question of self-perception. It rather involves an interplay of mechanisms that concur to preserve the group’s distinctive features and keep it shielded against threatening erasure. The investigation suggests to evidence, ultimately, that even though it exhibits broad consensus on basic elements of association that unify its individual members, notably Church and family, the Chaldean diaspora is by no means conflict-ridden. In effect, the persevering influx of co-ethnics fleeing persecution in the homeland appears to be a new source of internal frictions likely to polarize the community and precipitate an identity crisis.
Global Organizational Innovation Strategy
Authors: H. Godiwalla Yezdi
Published: July 2018

Global innovation strategy makes a global (or international) organization more competitive and contributes to long term growth. A focus on newer trends and approaches in the technology and internal and external organizational processes would help the innovative and entrepreneurial spirit and endeavor. The proper organizational entrepreneurial goals, strategy and culture would generate greater connectedness with the relevant task environments for the global organization to explore and subsequently pursue newer product and services. Altogether, the integrated global sharing, joint experimentation among its subsidiaries and their combined innovation effort, the well-interfaced global supply chain’s innovative endeavors, and the well-planned and systematic innovation strategy, together would spur greater global competitiveness and growth. It is a combined global approach that would effectively generate innovation.
Classroom Teacher Candidates’ Comprehension Levels of Key Concepts of the Life Science Curriculum
Authors: Akyıldız Salih , Altun Taner , Kasım Şengül
Published: July 2018

This study aims to investigate the comprehension levels of classroom teacher candidates about the key concepts of Life Science Curriculum. The study was carried out within the qualitative research approach and descriptive survey model was adopted. The sample of study consists of final year 114 classroom teacher candidates who are studying Primary Teacher Education Program at two different Education Faculties in Turkey. As a result of analyzing the primary Life Science curriculum, 18 foundational concepts were identified. In order to determine teachers' comprehension levels and conceptual misconceptions about these concepts, "concept definition form" consisting of short answer and open ended semi-structured questions prepared by researchers was used. The data obtained by the application of this form have been analysed through descriptive analysis method. The answers in the explanation section of the concept description form were evaluated in five categories as "comprehension", "partial comprehension", "incomprehension", "miscomprehension" and "no response". According to the findings obtained in the study, it was concluded that teacher candidates understand some of the concepts in the Life Science curriculum at a “good” level, mostly understand at “partially” level, “incomprehension” some concepts or have “miscomprehension”. In order to increase curriculum literacy, it is suggested that the primary teacher candidates should be given training about the main concepts related to the Life Science curriculum.
A Renaissance Robot
Authors: Herman David
Published: July 2018

This article focuses on a computer in downtown Manhattan that is displaying a robotics designer’s latest creation in action. Fashioned to look like an armored knight, the mechanical man in this three-dimensional simulation sits up, waves its arms, moves its head on a flexible neck, and opens and closes its hands and its jaw, all in smooth, precise motions. The robot could be used in a new motion picture, museum, or amusement park. Its original designer, however, never heard of movies, computers, or Wait Disney: The robot sprang from the mind of Leonardo da Vinci. Most Renaissance-era designers took a practical approach to mechanics, viewing each machine as a universal entity to be applied as a whole. Leonardo, however, used a revolutionary method of analysis that involved dissecting machines into individual components or “organs” and establishing how many essential parts exist; pulleys, chains, pinions, shock absorbers, springs, and friction bearings were just some of the elements he discovered to be common in many different machines. Leonardo’s studies have influenced and inspired Rossheim greatly in his current robotics designs. Leonardo followed the Renaissance ideal of “man as the measure,” the standard for which the world was designed.
A STEP to Improved CAD
Authors: Baumgartner Henry
Published: July 2018

This article highlights that by using a standard that enables complete product model data to be transmitted digitally, a company can build open systems to make information available on many platforms throughout its operations. The world of CAD/CAM has viewed the International Graphics Exchange Standard (IGES) as its translation standard for years, using the system to move two-dimensional models from one program to another. While IGES does, in fact, do a good job of transmitting basic geometry, another translator—the Standard for the Exchange of Product Data (STEP) —has been gaining on IGES in popularity. STEP goes considerably further than just transmitting geometry; it provides users with the ability to express and exchange digitally useful product information throughout a product's life cycle, including design, analysis, manufacturing, and support. In short, IGES transmits two-dimensional drawings, while STEP transmits complete product models. The updated schema, consisting of an ASCII file written in EXPRESS, is simply run through a utility that merges the extensions that have been added by Unigraphics with the standard ST-Developer libraries. Updating the translator to incorporate an upgraded version of the libraries is just as easy.
The Rise of VSR Motors
Authors: Paula Greg
Published: July 2018

This article reviews variable-switched reluctance (VSR) motors that are now entering mainstream use from jet fighters to washing machines. A VSR motor is generally used as a stepper motor and, if properly controlled, can be made to behave like a servomotor. Basically, the motor is a rotor and stator with a coil winding in the stator. VSR motors also provide other benefits. They can be programmed to precisely match the loads they serve, and their simple, rugged construction has no expensive magnets or squirrel cages like the ac induction motor. It can be difficult to give VSR motors a smooth torque profile, so they are used more often in place of variable speed motors than as servomotors. There are ways to control torque ripple, such as adding encoders and electronics to compensate, but these added controls could cost at least as much as what the motor itself would save. VSR motors work with relatively small air gaps. If the shaft is off-center, unbalanced tangential forces come into play, so shafts and bearing systems generally need to be of a higher quality than with other motors.
Smart Materials for Silent Alarms
Authors: Hedayatnia Mostafa
Published: July 2018

This article discusses the recent demand for silent alarms. If the device is kept close to a user’s body, such as on her\his wrist or in a back pocket, vibration is well suited for this type of alarm. The technology has been used for sometime in pagers, for example, and the field could someday be expanded to watches and a variety of medical equipment. The most common form of vibrating alert involves a motor that rotates an eccentric weight in an electromagnetic field. However, the smallest of these motors is still too large to fit in watches and other consumer products. Piezoceramic materials can produce motion by receiving electric potential across their polarized surfaces. Using finite-element analysis and optimization, engineers at Philips Corp. in Sunnyvale, Calif., have developed a miniature vibrator/piezo-bender that consumes only 8 milliamperes. In addition to optimization and actual shake tests, ergonomic research has been done to find the best way of improving the vibration performance of these silent alarms. Although the piezo-vibrator device shook strongly enough to get the wearer's attention in most environmental circumstances, that awareness improved greatly when vibrations were pulsed or interrupted.
Re-Engineering Aerospace Design
Authors: Valenti Michael
Published: July 2018

This article reviews that by integrating its CAD/CAM tools, Boeing’s Space Systems Unit hopes to enhance the quality of its products as it reduces both design- and manufacturing-cycle times. Sharper market competition led management to re-emphasize the practice and couple it with integrated CAD/CAM systems to provide a more supportive environment for concurrent engineering, thereby assuring the customer that cost, schedule, and quality goals would be met. This concept, called integrated product development (IPD), was launched in 1991. Boeing’s intention is to use the IPD strategy to reduce design-cycle time and manufacturing-cycle time as well as recurring costs. To support IPD, the Boeing designers developed electronic change control (ECC), an online system that enables engineers, technicians, manufacturers, and logisticians throughout the company to track and control engineering changes on a network of minicomputers, workstations, and desktops. Among the Unigraphics-based tools Boeing uses in IPD is the electronic development fixture (EDF), a three-dimensional digital model. EDF enables its users to electronically investigate fit, form, function, and interference detection.
Taking Sensors Out of Motors
Authors: Paula Greg
Published: July 2018

This article discusses that advanced signal processors are replacing the feedback sensors that had been required for motor control in applications ranging from disk drives to appliance motors. The traditional method of closed-loop motor control has been to use one or more sensors to provide feedback. A growing number of applications, however, are now eliminating the sensor through one of several methods, such as back electromotive force (EMF) or inductance measurement. Sensorless motors are best suited for applications where speed control is needed, but precise position control is not critical. Sensorless motors are proving to be most appropriate for applications where the position of the rotor does not have to be pinpointed with great accuracy and all that is needed is speed and torque control. Prime candidates for sensorless motors are applications where open-loop scalar control had been used but better speed regulation and more torque at low speed are needed.
Using Vibrations in Fluidized Beds
Authors: Fraas Arthur P.
Published: July 2018

This article focuses on processes that do not require a high flow rate of sweep gas; the complex-mode vibration-fluidized bed offers lower power needs, attrition rates, and elutriation rates than gas-fluidized beds or rotary kilns. The fluidized solids are induced to flow horizontally by inclining the trough and/or axis of vibration downward in the direction of solids flow. When viewing the operating region through a window in the side wall, the particles in the bed move in unison, like a column of marching soldiers. In light of the complexities and uncertainties in the interaction of adjacent particles in the fluidized bed, the dynamics of a single particle falling on a horizontal plate vibrating along a vertical axis should be considered first. Because the complex-mode vibration-fluidized bed can be tailored for certain applications, a number of projects are currently in the early stages of development. Promising uses include coal pyrolysis to produce fuel for gas turbines in combined-cycle power plants, the manufacture of char for superior activated carbon, recycled synthetic fiber in carpeting, and counterflow heat exchangers.
Super-Slick
Authors: DeGaspari John
Published: July 2018

This article discusses that the Argonne National Laboratory is beginning real-world tests of a carbon-based substance that has set records for low friction. An extremely hard ultralow-friction carbon coating, developed at Argonne National Laboratory in Argonne, IL, may offer a way to address friction and wear. Introduced about a year and a half ago, the new coating is nearly friction less under inert conditions. Argonne is working with three development partners, which have signed three-year cooperative research and development agreements to transfer this technology to industry. Two of the companies are working with engine applications; one is a commercial coater, adapting the near-frictionless material to its coating process. One of Argonne’s partners, Front Edge Technology Inc., an industrial coater in Baldwin Park, CA, is using a plasma-enhanced chemical vapor deposition process with the coating. Potential applications of the coating are in the mechanical drive portion of the engine, in which the reciprocating piston motions are converted into a rotating shaft motion.
Fueling the Cells
Authors: Sharke Paul
Published: July 2018

This article focuses on how scientists, environmentalists, industrialists, and engineers are slowly beginning to agree that energy for the 21st century is going to come from hydrogen. The fuel cell, itself an invention that dates back more than 150 years, will be partly responsible for this change. Among the fossil fuels, petroleum and natural gas are considered primary contenders to provide a source of mobile hydrogen. They have higher ratios of hydrogen to carbon dioxide when compared to coal. Coal, with 50 percent hydrogen, may simply be too rich in carbon dioxide to provide an attractive source of fuel-cell energy. New demand for stationary fuel cells would then bring about a reduction in their costs through mass-production efficiencies. Although the price of fuel cells might not rival that of internal combustion engines, fuel cell pricing could fall enough to make them practical in tomorrow's super-efficient cars. A hydrogen infrastructure would follow as fuel cell vehicles caught on.
The Business of Engineering
Authors: Thilmany Jean
Published: July 2018

This article elucidates how computerized product data management (PDM) systems allow designers to immediately be apprised of changes and communicate them to others in the manufacturing chain, and to discuss, via their computers, project status or glitches in the process. Datel of Mansfield, MA, has used a computer system called OnTrack to closely follow production of the power converters and other products it makes for use primarily in the telecommunications industry. The OnTrack system automatically sends its pertinent information gleaned from the PDM system to the planner. If the part is already being made without this latest revision, information about its current production is included in the file. This information can be a listing of the specific workstations on which each particular part has been made and how they have been configured for part production. Because many companies now include engineering departments when linking a company’s financial or manufacturing information, the engineers themselves have access to information used to run the business. Moreover, more information means that they have a greater say in decision making.
From the Crystal Palace to the Pump Room
Authors: Engeda Abraham
Published: July 2018

This article discusses centrifugal pumps and compressors that have reached efficiency levels above 90 percent and are built in sizes ranging from a few watts to megawatts. As machines have evolved to handle a wider range of liquids and gases at higher pressures and temperatures, whole industries have become dependent on them. The centrifugal impellers in these pumps and compressors make them among the most complex fluid machines ever built. The development of the centrifugal impeller has been helped because the device can be used in both pumps and compressors. The earliest development occurred in pumps, which were more advanced than compressors until early in the 20th century.
Role Models
Authors: Brown Alan S.
Published: July 2018

This article focuses on the fact that by inserting digital humans into that virtual world—or stepping into it themselves—engineers have found new ways to test designs for ergonomics, manufacturability, maintainability, safety, and style. The goal, of course, is to design better, higher quality products faster and cheaper by getting everyone from manufacturing and quality through safety and maintenance involved in the process before settling on a design. The approach, called concurrent engineering, has been talked about since the quality revolution in the 1980s. Digital humans provide important insights into the design of production and assembly equipment. By simulating the task with large digital populations, safety engineers can determine before a machine goes into production whether anyone is likely to circumvent its safety features. One way to overcome behavior barriers is to put real people in simulations.
Syngas Europa
Authors: Minchener A.J.
Published: July 2018

This article highlights that the European Commission is supporting a wide range of clean coal technology research and development initiatives, including those known as APAS (Activité de Promotion, d'Accompagnement et de Suivi) and Joule (after the 19th-century British physicist James Joule). APAS, a two-year multiple-partner program, was set up to evaluate gasification processes using biomass, sewage sludge, and other wastes as co-feedstocks with coal. The Joule 3 co-gasification initiative was designed to aid European industry to address the technical issues for fluidized bed co-gasification applications. The Joule 2 project for the enhancement of the efficiency of coal-fired power generation systems was undertaken by Siemens and the University of Essen in Germany, and Babcock and Wilcox Espanola in Spain. In the Joule 3 project on advanced cycle technologies, the University of Essen and four partners have investigated measures to reduce costs, enhance efficiency, and provide a basis for an advanced design. The studies also included co-gasification of coal and biomass in an entrained-flow gasifier suitable for IGCCs.
Can-do Packaging
Authors: Sharke Paul
Published: July 2018

This article highlights the next generation of can decorating machines by packagers and the manufacturers of packaging machinery. To build their new next-generation decorator, Alcoa Packaging Machinery’s (APM) engineers were given the rare opportunity to develop the machine from a “white sheet.” The four-color decorator is a continuous-motion, rotary machine, which holds each can body upright on a mandrel. Each can rolls against a blanket cylinder, which transfers an inked pattern from a plate cylinder. APM’s engineers were especially interested in finding out how the mandrel shafts would deflect under load. Deflection is an important consideration for any rotary printer because it determines how well an image will transfer between rolls. APM is planning to unveil its new can decorator at a metal packaging trade show in Germany. The machine has yet to be proven in production, but the design has progressed.
Relief for Weary Bones
Authors: Hutchinson Harry
Published: July 2018

Research using engineering tools is making new options possible in the study and preservation of ancient finds. According to the manager of Dinosaur Hall at the Smithsonian Institution, the plan is to keep the original fossil bones off the floor, in a collection available for study by scholars, and to replace the skeleton with a replica created by methods that will include 3D modeling and rapid prototyping. Computer animations will help recreate the way the animal stood. The optical scanner analyzes an object in a series of small areas, or patches, which must be assembled to create the overall picture. In order to set up the later alignment of the scans, an engineer mapped a digital outline of the Triceratops. Restorers are expected to use the conserved Triceratops bones as patterns for molds, but when parts are missing or mismatched, mirror images will fill in. Paleobiologists will also use the scale model, along with Virtual Surfaces' animations, to study possible reconstructions of the dinosaur's stance.
FEA on the Assembly Line
Authors: Landgraf Mathias C.
Published: July 2018

Structural and dynamic analyses of a new machining fixture help Porsche AG get production up and running faster. Porsche contracted with KTW Konstruktion Technik K. Weisshaupt GmbH of Friedrichshafen, Germany, to design and produce the fixtures required to hold automobile motor parts in place during drilling and high-precision milling. It has been noted that using a 3-D computer-aided design (CAD) solid modeler can point out weaknesses before a design leaves the computer. In order to avoid the need for costly generations of prototypes prior to the casting process, Speedy Engineering in Immenstaad, Germany, used finite element analysis software to perform linear static and dynamic (vibration) analyses of the motor component fixture geometry within only a few days of its design, to determine displacements and eigenfrequencies of the geometry. The results of the static and dynamic analyses enabled Speedy to specify maximum working loads for •production, which guaranteed success with the first use of this fixture design.
Crossing Disciplines
Authors: Witzel John G.
Published: July 2018

At the Georgia Institute of Technology, the Woodruff School of Mechanical Engineering has taken steps to introduce curriculum that enable engineering graduates to be able to function on multidisciplinary teams. The institute provide tools and support necessary for its graduates not only to function, but also to contribute more effectively in multidisciplinary efforts. One support mechanism that is helping to broaden students' experience and skills at Georgia Tech is the Mechanical Engineering Electronics Support Lab. Currently, three long-range design projects are in the lab: an eight-channel programmable H2O pump for use in human bone growth experiments; a 12-channel high-voltage controller for piezoelectric actuators to manipulate fluidic flow patterns within a wind tunnel; and, for the same experiment, a precision bank of hot-wire anemometers for velocity measurements. The lab's greatest measure of success has been the high rate of return customers and word-of-mouth recommendations. Faculty from other departments have approached the lab regarding their design and fabrication needs—a strong indicator that the facility must be doing something right.
Predicting Durability
Authors: Muju Sandeep , Sager Robert L. , Snider Benny J.
Published: July 2018

This article discusses that thermomechanical simulation helps optimize a catalytic converter assembly for durability and performance. A careful examination of a typical, freshly manufactured vermiculite m at reveals high Hertzian-type mat deformation under the inward ribs. Excess pressures under these ribs during canning may lead to substrate cracking or microfractures in the mat, which under gas impingement may lead to accelerated mat erosion. The present study also has been focused on thermomechanical modeling of the vermiculite mat's swelling and its effect on durability, using the Abaqus nonlinear finite element analysis code from Hibbit, Karlsson & Sorensen Inc., Pawtucket, RI, to study the case of a clam-shell converter package with ceramic package and vermiculite-ceramic mat. Because of the viscoelastic nature of the mat, the instantaneous load displacement curve typically shows a stiffer response than the steady-state response. Because of the relatively high compressibility of the mat material, the hyperfoam formulation based on Hill's strain energy potential is taken as the appropriate constitutive model.