bluuebunny/crossref_metadata_2025 huggingface dataset:
Regression of hepatocellular adenoma after bariatric surgery in severe obese patients
Authors: Gevers Tom J. G. , Marcel Spanier B. W. , Veendrick Peter B. , Vrolijk Jan Maarten
Published: July 2018

Background & Aim

Obesity and metabolic syndrome are increasingly recognized as risk factors for hepatocellular adenomas (HCA). There is still sparse evidence whether weight loss or bariatric surgery could induce HCA regression in these patients. In this brief report we describe the effect of weight loss on HCA regression in severe obese patients that had undergone bariatric surgery in our centre.

Methods

We performed an Electronic Patient Database search and included all patients who underwent bariatric surgery in our bariatric referral centre and had an ICD‐10 code of benign neoplasm of liver in our centre from (2006‐2017). All imaging studies of eligible patients were re‐evaluated by the study radiologist. Primary outcome was change in maximal diameter of HCA.

Results

Six of 11 eligible patients were excluded because their lesions were classified as probable focal nodular hyperplasia and two were lost to follow‐up. Finally, three women with solitary (n = 1) or multiple HCA (n = 2) and a body mass index (BMI) ranging between 39 and 50 kg/m2 were included. In two patients, HCA completely regressed in 1‐2 years following bariatric surgery, after BMI reductions of 36%‐48%. The third patient showed a reduction of >50% in diameter of the largest HCA in 2.5 years after bariatric surgery (31% BMI reduction), with complete resolution of smaller HCA.

Conclusions

Bariatric induced weight loss results in significant regression of HCA in severe obese women, which emphasizes the role of overweight in HCA pathophysiology.
Secondary amplification of siRNA machinery limits the application of spray‐induced gene silencing
Authors: Song Xiu‐Shi , Gu Kai‐Xin , Duan Xiao‐Xin , Xiao Xue‐Mei , Hou Yi‐Ping , Duan Ya‐Bing , Wang Jian‐Xin , Yu Na , Zhou Ming‐Guo
Published: July 2018

Spray‐induced gene silencing (SIGS) is an innovative strategy for crop protection. However, the mechanism of SIGS is not known. Here, we first demonstrate that secondary small interfering RNA (siRNA) amplification limits the application of SIGS. A myosin5 gene (Myo5) was chosen as the target of SIGS in an agronomically important pathogen—Fusarium asiaticum. Five segments corresponding to the different regions of the Myo5 gene were found to efficiently silence Myo5, resulting in cell wall defects, life cycle disruption and virulence reduction. Myo5‐8 (one of the Myo5 segments) induced sequence‐specific RNA interference (RNAi) activity in F. asiaticum, F. graminearum, F. tricinctum and F. oxysporum, but not in other fungi, in vitro. Remarkably, the silencing of Myo5 lasted for only 9 h unless the double‐stranded RNA (dsRNA) was continuously supplied, because F. asiaticum is unable to maintain siRNA amplification. After spraying on plants, dsRNAs were more efficiently taken up via the wounded surface. The antifungal activity of dsRNAs taken up by plant cells was higher and longer lasting than that dried onto the plant surface. In contrast with dsRNAs in fungi, dsRNAs in plant cells could efficiently turn into substantial siRNAs via secondary amplification machinery. Our findings provide new implications to develop SIGS as a mainstream disease control strategy against Fusarium and other fungi.
Synergistic action of GCN5 and CLAVATA1 in the regulation of gynoecium development in Arabidopsis thaliana
Authors: Poulios Stylianos , Vlachonasios Konstantinos E.
Published: July 2018

In Arabidopsis thaliana the CLAVATA1 (CLV1) receptor and GENERAL CONTROL NON DEREPRESSIBLE 5 (GCN5) histone acetyltransferase both regulate inflorescence meristem size and affect the expression of the meristem‐promoting transcription factor WUSCHEL (WUS).

Single and multiple mutants of GCN5 and CLAVATA members, were analysed for their gynoecium development, using morphological, physiological, genetic and molecular approaches.

The clv1‐1gcn5‐1 double mutants exhibited novel phenotypes including elongated gynoecia with reduced valves and enlarged stigma and style, indicating a synergistic action of CLAVATA signaling and GCN5 action in the development of the gynoecium. Reporter line and gene expression analysis showed that clv1‐1gcn5‐1 plants have altered auxin and cytokinin response, distribution and ectopic overexpression of WUS. WUS expression was found in the style of wild‐type gynoecia stage 10–13, suggesting a possible novel role for WUS in the development of the style.

CLV1 and GCN5 are regulators of apical–basal and mediolateral polarity of the Arabidopsis gynoecium. They affect gynoecium morphogenesis through the negative regulation of auxin biosynthesis and promotion of polar auxin transport. They also promote cytokinin signaling in the carpel margin meristem and negatively regulate it at the stigma. Finally, they synergistically suppress WUS at the centre of the gynoecium.
Water stress limits transpiration and growth of European larch up to the lower subalpine belt in an inner‐alpine dry valley
Authors: Obojes Nikolaus , Meurer Armin , Newesely Christian , Tasser Erich , Oberhuber Walter , Mayr Stefan , Tappeiner Ulrike
Published: July 2018

Climate change will further constrain water availability in dry inner‐alpine environments and affect water relations and growth conditions in mountain forests, including the widespread larch forests.

To estimate the effects of climate conditions on water balance and growth, variation in sap flow and stem radius of European larch was measured for 3 yr along an elevation transect from 1070 to 2250 m above sea level (asl) in an inner‐alpine dry valley in South Tyrol/Italy. Additionally, long‐term climate–growth relations were derived from tree cores.

Sap flow and radial growth were reduced in dry periods up to an elevation of 1715 m, leading to maximum annual growth at 2000 m. In a wet year no growth difference between elevations was observed. Long‐term tree ring data showed a positive growth response to precipitation up to 1715 m and to temperature only above 2000 m.

Our results demonstrate that reduced water availability and higher atmospheric water demand limit larch at low elevation within dry Alpine regions. This indicates a general upward shift of this species’ elevational amplitude upon climate change, and respective negative effects on future silvicultural use and ecosystem services at lower elevations in the European Alps.
What if they had not Gone Negative? A Counterfactual Assessment of the Impact from Negative Interest Rates
Authors: Michail Nektarios A.
Published: July 2018

The counterfactual estimation technique of Pesaran and Smith () is employed to provide an assessment of the impact stemming from the implementation of negative interest rates in three European economies (Denmark, Sweden and Switzerland). The analysis indicates that negative interest rates did not have a significant effect on bank lending growth or inflation in any country. This failure to reject the policy ineffectiveness hypothesis most likely lies in the fact that negative interest rates did not ease the situation for the factors restricting the supply of bank lending, namely bank funding costs and Return‐on‐Equity.
Adverse events involving mandibular hardware: an analysis of the Food and Drug Administration Facility Device Experience data
Authors: Elias M. L. , Weisberger J. S. , Barinsky G. L. , Paskhover B.
Published: July 2018

Purpose

To investigate frequencies and characteristics concerning mandibular device complications as reported to the Food and Drug Administration.

Study Design

Retrospective database review.

Methods

The Manufacturer and User Facility Device Experience (MAUDE) database was queried for reports from 2007 to 2017 using the keywords ‘mandible’ and ‘mandibular’. A total of 3592 reports were gathered. After curating out duplicate reports, reports not applicable to mandibular hardware, and literature articles, 1899 event device reports were subsequently studied for mandibular hardware. A side cohort of 192 TMJ device reports was analysed separately. Reports were reviewed based on both the device cited in the report and the concerns cited in the event text (i.e. an explanation of a plate fracture/failure or of an infection). Additional frequencies involving the company manufacturers and reported patient injury were also analysed.

Results

The majority of the 1899 mandibular device reports cited screw failures (20.4%), infection (15.8%), plate fracture (12.9%), or distractor malfunction (7.9%). Of all the records, 60.3% self‐categorised themselves as ‘injury’ events, whereas 36.4% self‐classified as ‘malfunction’ reports. The plate fractures consisted of 79.8% occurring post‐operatively and 14.0% intra‐operatively. A majority of the implicated screw failures were regular, non‐intermaxillary fixation/mandibulomaxillary fixation screws (75.3%). Depuy Synthes (59.6%) and Stryker (16.6%) were most often implicated in these 1899 mandibular reports. Of the separate 192 TMJ reports, the events indicated mainly jaw pain 32.0%, incorrect fit of the device (11.2%), infection (10.7%), loose screws (9.6%), and dislocation in the patient post‐operatively (7.6%), with Biomet involved in the majority of reports (90.8%).

Conclusions

The MAUDE reports on mandibular devices correspond with the major adverse events cited in previous literature. The reports delineate areas of improvement for both manufacturers (i.e. post‐operative hardware failure and intra‐operative equipment failures) verses probable user error (i.e. intra‐operative plate and patient injuries).
The effect of baked milk on accelerating unheated cow's milk tolerance: A control randomized clinical trial
Authors: Esmaeilzadeh Hossein , Alyasin Soheila , Haghighat Mahmoud , Nabavizadeh Hesamodin , Esmaeilzadeh Elmira , Mosavat Fereshteh
Published: July 2018

Background

Assessing the effect of adding baked milk products to the diet of patients with cow's milk allergy on accelerating the formation of tolerance.

Method

A randomized clinical trial was carried out with 84 patients (6 months‐3 years old) diagnosed with allergy to cow's milk who tolerated baked milk in form of muffin in oral food challenge (OFC). The subjects were divided randomly into case and control groups matched for age and sex. Patients in the case group were asked to consume baked milk in the form of muffin for 6 months and then to consume baked cheese in the form of pizza for another 6 months. The control group were instructed to strictly avoid any milk products for 1 year. Skin prick test (SPT) and serum‐specific immunoglobulin E (sIgE) levels (ImmunoCAP) of milk, casein, and beta‐lactoglobulin were measured before and after the study. In addition, those in the case group who had satisfactorily tolerated baked products during the study as well as all the subjects in the control group underwent an OFC to evaluate unheated milk tolerance at the end of the study.

Results

It was shown that by the end of the 1‐year study period, 88.1% (37/42) of the patients in the case group and 66.7% (28/42) of those in control group had developed tolerance to unheated milk (P‐value: 0.018). The results of milk‐specific SPT and sIgE levels showed a significant decrease in the case group. Initial sIgE levels could not predict unheated milk tolerance in case and control groups.

Conclusion

Introducing baked milk products into the diet of patients with milk allergy can accelerate the tolerance of unheated milk in these patients. sIgE levels of milk, casein, and beta‐lactoglobulin did not predict the tolerance of unheated milk.
SC1 sustains the self‐renewal capacity and pluripotency of chicken blastodermal cells by inhibiting the phosphorylation of ERK1 and promoting the phosphorylation of Akt
Authors: Li Rongyang , Tang Xiaochuan , Xu Shiyong , Chen Qing , Chen Baobao , Liu Shuo , Li Bojiang , Li Weijian , Yao Yilong , Wu Wangjun , Liu Honglin
Published: July 2018

Small molecules discovered during the recent years can be used to regulate the growth of embryonic stem cells (ES cells). Chicken blastodermal cells (cBCs) play an important role in both basic and transgenic researches as an important ES cell. However, the regulatory mechanism of small molecules involved in the self‐renewal and pluripotency of cBCs remains unknown. This study revealed that the small molecule, SC1, can maintain cBCs in an undifferentiated, pluripotent state in serum‐ and feeder‐free E8 media without leukaemia inhibitory factor. Furthermore, SC1 inhibits downregulation of pluripotency‐related genes caused by retinoic acid and promotes the proliferation of cBCs. Furthermore, the results of this study indicated that SC1 functions by inhibiting ERK1 phosphorylation and promoting Akt phosphorylation, thus promoting the expression of pluripotency‐related genes and maintaining the pluripotency of cBCs. The results also demonstrated that SC1 sustains the self‐renewal capacity and pluripotency of cBCs cells by inhibiting ERK1 phosphorylation and promoting Akt phosphorylation. This kind of regulatory mechanism might be conserved in avian ES cells. Other molecules, similar to SC1, might provide insights into the molecular mechanisms that control the fate of stem cells and ultimately help in‐vivo stem cell biology and therapy.
Expression of aquaporin 4 in the chicken oviduct following tamoxifen treatment
Authors: Socha Joanna K. , Saito Noboru , Wolak Dominika , Sechman Andrzej , Hrabia Anna
Published: July 2018

Contents

This study was designed to examine whether aquaporin 4 (AQP4) is present in the chicken oviduct, and if so, whether its expression changes during pause in laying induced by tamoxifen (TMX; oestrogen receptor modulator) treatment. The control chickens were injected with a vehicle (ethanol) and the experimental ones with TMX at a dose of 6 mg/kg of body weight. Birds were treated daily until complete cessation of egg laying. The oviductal parts, that is the infundibulum, magnum, isthmus, shell gland and vagina were isolated from hens on day 8 of the experiment, and subsequently, the gene and protein expressions of AQP4 in tissues were examined by real‐time PCR and Western blot, respectively. Immunohistochemical localization of AQP4 in the wall of the chicken oviduct was also investigated. Both mRNA and protein of AQP4 were found in all segments of the chicken oviduct. The relative expression [RQ] of AQP4 was the highest in the infundibulum and the vagina and the lowest, less detectable, in the magnum and isthmus. The pattern of AQP4 protein expression was similar to that of mRNA. Treatment of hens with TMX decreased the mRNA and protein levels of AQP4 in the oviduct. Immunohistochemistry demonstrated tissue and cell‐dependent localization of AQP4 protein in the oviductal wall. The intensity of the immunopositive reaction was as follows: the infundibulum > vagina > shell gland ≥ isthmus >˃ magnum. In the control chickens, the immunoreactivity for AQP4 in all oviductal segments was stronger compared with the TMX‐treated hens. The results obtained indicate that AQP4 takes part in the regulation of water transport required for the formation of egg in the chicken oviduct. Moreover, a relationship between oestrogen action and AQP4 gene and protein expression is suggested.
Occurrence and Chemical Compositions of Amphiboles in Altered Dioritic Rocks of Laiwu Skarn‐Type Iron Deposit in West Shandong Area, China
Authors: Jin Ziliang , Zhang Zhaochong , Santosh M. , Han Liu
Published: July 2018

The Laiwu Fe deposit is the largest skarn‐type deposit in West Shandong in China, with an estimated reserve of 290 Mt of iron ore. Here, we investigate the occurrence and chemical composition of amphiboles in altered dioritic rocks of this deposit. Three generations of amphibole group minerals were identified in these rocks. The first type (Type 1) is a hornblende with a generally euhedral crystal shape, 150–500 μm in size, and dominantly occurs in the host monzonite. The second type (Type 2) of hornblende occurs as fine grains (<100 μm) or concentric rims, less than 50 μm in thickness, around the Type 1 hornblende. The third type (Type 3) of amphibole is anhedral actinolite occurring along the boundary or the cracks of the Type 1 or 2 hornblende grains. The Type 1 hornblende has higher FeO (12.5–15.6 wt.%) and lower MgO contents (11.2–14.6 wt.%) than the Type 2 hornblende, which has an FeO content ranging from 8.8 to 10.5 wt.% and MgO content ranging from 14.2 to 17.1 wt.%. The Type 3 actinolite shows the lowest FeO (4.6–6.4 wt.%) and highest MgO (19.8–21.2 wt.%) contents. We infer that the Type 2 hornblende formed from Fe‐rich hydrothermal fluids released during rapid upwelling of the crystallizing magma. The fluids were relatively reduced and enriched in Fe. The Type 3 actinolite formed by coupled dissolution and reprecipitation, and its formation is one of the features denoting Fe‐enrichment events. Our study of these types of amphibole provides insights into the ore formation process.
High‐energy inundation events versus long‐term coastal processes – room for misinterpretation
Authors: Spiske Michaela , Garcia Garcia Anna‐Marietta , Tsukamoto Sumiko , Schmidt Volkmar
Published: July 2018

Coastal boulder deposits and chevrons are two features whose origin have triggered controversial discussions. Boulders are often used as indicators of past tsunamis and storms, with the former interpretation in many cases preferred due to the clast size. Chevrons, defined as large parabolic sand bodies, were previously attributed to (mega‐)tsunami, potentially caused by oceanic impacts, because of their dimensions, height above sea level and alignment of the central axis. This study documents that chevrons along the Quobba coast in Western Australia are parabolic dunes and not related to tsunami inundation; their age is consistent with an arid period at about 3·9 to 2·3 ka when the sea level was 1 to 2 m higher than today. The internal age distribution proves an inland migration. Weakly developed soil horizons represent phases of intermittent dune stabilization and later reactivation. The calculated velocities required for wind transport and the prevailing wind directions are consistent with on‐site meteorological parameters. The boulders at Quobba are most likely to be remnants of in situ platform denudation that produces shell hash, coral clasts and boulders. An unknown portion of the boulders was certainly moved by tropical cyclones. A previously proposed tsunami origin is unsustainable because the observed features can be explained by processes other than tsunamis. Boulders were tilted during gravitative platform collapse, standing water caused dissolution of the boulder bottoms, creating ‘pseudo‐rockpools’, consequently not applicable as upside‐down criteria, and ages of attached encrusting organisms document their colonization at higher sea level and (sub)recent frequent inundation by wave splash during rough seas.
Minute‐to‐minute trajectories of child unresponsiveness and parent sensitivity in parent–child interactions: The role of DRD4
Authors: Elam Kit K. , DiLalla Lisabeth F.
Published: July 2018

Elevated and persistent childhood unresponsiveness to others (not responding to cues from others during interactions) may be due to a combination of early environmental and biological influences. However, little is known about how sensitive parenting may influence minute‐to‐minute changes in child unresponsiveness. The present study examines trajectories of child unresponsiveness to parent and parent sensitivity across a 10‐minute parent–child interaction, and also examines variation by children's DRD4 genotype. Child unresponsiveness and parent sensitivity were assessed minute by minute for 246 twins during a puzzle task. Latent growth curve models demonstrated that increasing trajectories of child unresponsiveness and decreasing trajectories of parent sensitivity were associated across the 10‐minute interaction. When examined by genotype, this association was present only for children with the DRD4 7‐repeat allele (the putative ‘risk’ allele). In addition, initial levels of parent sensitivity predicted trajectories of child unresponsiveness only in children with a DRD4 7‐repeat allele. This examination of gene‐environment interaction illustrates the value of considering both genotype and the parenting environment in consideration of preschool children's development of unresponsive behavior. It also supports the importance of investigating the interplay between minute‐level parenting and child behavior in explaining child development.
How do my parents react when I feel happy? Longitudinal associations with adolescent depressive symptoms, anhedonia, and positive affect regulation
Authors: Nelis Sabine , Bastin Margot , Raes Filip , Bijttebier Patricia
Published: July 2018

Parental emotion socialization plays a role in the development of adolescents’ emotion regulation and is associated with adolescents’ depressive symptoms. Most research has focused on parental socialization of negative affect. The scarce research on parental socialization of positive affect (PA) shows that parental downgrading responses to adolescents’ PA are associated with concurrent adolescent depression. The aims of the present study were to examine longitudinal associations of both maternal and paternal responses to adolescents’ PA with how adolescents regulate their PA (i.e., dampening and enhancing) and with adolescents’ general depressive symptoms and anhedonia. We also considered associations in the opposite direction from adolescent regulatory responses and symptoms to parental responses. In a two‐wave study (1‐year interval), 635 adolescents from Grade seven completed questionnaires. Cross‐sectionally, maternal and paternal responses to adolescents’ PA were associated with concurrent adolescents’ PA regulation as well as adolescents’ depressive and anhedonic symptoms. Longitudinally, low maternal and paternal enhancing responses to adolescents’ PA predicted relative increases in anhedonic symptoms and relative decreases in adolescent enhancing over time. Low maternal enhancing was also predictive of relative increases in depressive symptoms. The present study points to bidirectionality of relations as adolescents’ level of depressive symptoms predicted maternal and paternal responses.
Transepidermal water loss, stratum corneum hydration, and skin surface pH of female African and Caucasian nursing students
Authors: Young Monica M , Franken Anja , du Plessis Johan L
Published: July 2018

Background

Conflicting evidence exists on how skin barrier function compares between Africans and Caucasians. This study measured skin barrier function of South African first year nursing students before their practical training started to compare skin barrier function between the racial groups.

Methods

Transepidermal water loss (TEWL), stratum corneum (SC) hydration, and skin surface (SS) pH was measured on female first year nursing students (19 African and 31 Caucasian; age range 18‐40 years). Geometric means and ranges were calculated and the influence of anatomical areas and racial differences were evaluated respectively.

Results

No significant difference in TEWL was established between the racial groups. SC hydration was significantly lower (P ≤ 0.05) and SS‐pH was significantly higher (P ≤ 0.0001) in African nursing students when compared to Caucasians. African nursing students had significantly lower (P ≤ 0.05) SC hydration on their palms when compared to the other anatomical areas.

Conclusion

Stratum corneum hydration and SS‐pH differed significantly between African and Caucasian skin, while no difference was found for TEWL, the primary parameter used to evaluate skin barrier function. Low SC hydration and high SS‐pH of African nursing students prior to their practical training, may suggest a higher risk for developing occupational skin diseases.
Plasmid‐mediated quinolone resistance in human non‐typhoidal Salmonella infections: An emerging public health problem in the United States
Authors: Karp Beth E. , Campbell Davina , Chen Jessica C. , Folster Jason P. , Friedman Cindy R.
Published: July 2018

Invasive Salmonella infections in adults are commonly treated with fluoroquinolones, a critically important antimicrobial class. Historically, quinolone resistance was the result of chromosomal mutations, but plasmid‐mediated quinolone resistance (PMQR) has emerged and is increasingly being reported in Enterobacteriaceae worldwide. PMQR may facilitate the spread of quinolone resistance, lead to higher‐level quinolone resistance, and make infections harder to treat. To better understand the epidemiology of PMQR in non‐typhoidal Salmonella causing human infections in the United States, we looked at trends in quinolone resistance among isolates submitted to the Centers for Disease Control and Prevention. We reviewed demographic, exposure and outcome information for patients with isolates having a PMQR‐associated phenotype during 2008–2014 and tested isolates for quinolone resistance mechanisms. We found that PMQR is emerging among non‐typhoidal Salmonella causing human infections in the United States and that international travel, reptile and amphibian exposure, and food are likely sources of human infection.
Using Risk Characteristics to Classify Funds
Authors: Kainja Joe
Published: July 2018

We analyzed the South African general equity unit trusts for the period 30 June 2002 to 31 December 2014 to assess if we can re-categorize them into risk homogeneity groups. The current ASISA standards do not fully classify the unit trusts into categories that have within-group homogeneity and between-group heterogeneity.By analyzing the persistence of both systematic and total risk we concluded that we could objectively classify these unit trusts into objective risk homogeneity groups and improve on the current ASISA-mandate-based classification.
Matsuyama University´s Statistical Studies (Using Annual Paid Vacation Research as the Basis for Student Development) Through the Use of a Student´s Graduation Thesis Results
Authors: Igusa Go
Published: July 2018

This publication seeks to consider statistics education in Japan while referencing a student paper. The paper to be considered is as follows: "Gakusei no Koudou ga Gakusei Seikatsu Manzokudo ni Ataeru Eikyou" (The Influence of Student Behavior on the Degree of Satisfaction Perceived in Student Life).
Diagnostic accuracy of the [-2]Pro-PSA and Prostate Health Index versus the Gleason score for determining the aggressiveness of prostate cancer: a systematic review protocol
Authors: Anyango Ruth , Ojwando Joel , Mwita Clifford , Mugalo Edward
Published: July 2018

Review questions
Dynamic Analysis Step-by-Step
Authors: Kwon Yi Sug
Published: July 2018

This article discusses about engineers who are relying on mechanical simulations to improve their understanding of loading and operating conditions with high-rise escalators gain in popularity. To model an escalator design’s steps for dynamic analysis, LG engineers simplified the mechanical system by applying the drive directly to the upper terminal gear and the driving pulley without the motor. To model an escalator’s continuous elastic handrail, LG engineers divided it into 127 discrete rigid bodies, resulting in a total of 381 independent degrees of freedom. Two friction contact elements for each handrail body are applied to prevent rotational motion of the handrail. LG Industrial Systems managers decided to expand the number of engineers at the company with access to the simulation model. They assigned LG engineers to work with Computer Aided Design Software, Inc. (CADSI), of Coralville, Iowa analysts to develop a front end to DADS that simplifies the process of developing a custom escalator model.
Seeing Reduced Diesel Emissions
Authors: Han Zhiyu , Reitz Rolf D.
Published: July 2018

This article highlights animated three-dimensional computer models that show how to control the biggest pollutants coming from diesel engines. Increasingly strict regulations have led engineers to search for new ways of controlling the polluting emissions from diesel engines without compromising fuel economy. The past experiments tended to yield the same disappointing results-nitrogen oxide emissions increased if soot emissions were reduced and vice versa. Using animated three-dimensional computer models, researchers at the University of Wisconsin's Engine Research Center (ERC) in Madison found that multiple high-pressure injections enabled soot and nitrogen oxide emissions to be reduced at the same time. The discovery of the new multiple-injection method is significant for diesel-engine design. The combustion models developed at the ERC are now being used at major engine and automotive companies. Because engineers now know how to reduce nitrogen oxide and soot simultaneously, they can apply this mechanism to improve injection-scheme designs.
Human-Centric Design
Authors: Morrissey Mark
Published: July 2018

This article reviews that advances in manikin software have enabled engineers to consider a fuller spectrum of user interactions with virtual products. It has been 15 years since Sammie—a computer model of a human or manikin—emerged from the research labs of Nottingham University in the United Kingdom, promising human-factors (HF) engineers a supporting software tool to improve the study of human elements of product design. Although Sammie incorporated accurate anthropometric data and representative joint constraints, the software was very difficult to use, could not import models from a computer-aided-design (CAD) system, and was not dynamic. After phase 1 of the collaborative project, Rolls-Royce and VSEL expanded their study to evaluate the use of virtual reality for the design and layout of larger and more complex machinery spaces. This second collaborative effort had several objectives: to understand how virtual-prototyping technology could help designers better visualize complex designs, design for ease of assembly and maintenance much earlier, train maintenance engineers, and enhance communications between disparate project teams, customers, and suppliers.
Current Directions in Meshing
Authors: Bathe Klaus-Jürgen
Published: July 2018

This article highlights the preparation of finite element models for analysis that is being increasingly automated, with new developments expected to greatly advance the field. The key to an efficient finite-element analysis (FEA) is frequently an effective finite-element mesh. The construction of this mesh is the first step in the analysis process. Structured grids, as is implied by the name, have a clear structure. The techniques used to generate them produce quadrilateral or triangular cells, or elements, in two-dimensional analysis, and tetrahedral or hexahedral elements in three-dimensional simulations. An area of great potential is the automatic adaptation of the mesh, without intervention by the analyst, and automatic continued solution until the required accuracy has been reached. To effectively automate the choice of the mathematical model and its solution, major advances in theoretical issues and software development are still required and will provide an exciting challenge for the years to come.
Making it in the Competitive World
Authors: Koenig Dan
Published: July 2018

This article explains a logical, seven-step approach that helps to solve problems of on-time product and service delivery with profit. The first step is to obtain product specifications. The next step is to design a method for producing the product, including the design and purchase of equipment and production processes, if required. Scheduling for production is the coordination step; if not done well, it will spell doom for the company. Coordination is the key to purchasing raw materials in accordance with the schedule. Next is the transformation phase of raw materials to finished product—actual factory production—which is commonly called the value-added step. The quality assurance phase of monitoring results for technical compliance and cost control is an ongoing process of constant vigilance and continuous improvement. This step seeks to ensure that the product or service is being provided in accordance with the plan, a plan that includes technical, schedule, and cost goals. The best companies use total quality management (TQM), whereby improvement is continuous, as exemplified symbolically by the TQM triangle.
A Cradle for New Steel Technologies
Authors: Valenti Michael
Published: July 2018

The U.S. Department of Energy is reducing various risks through its Office of Industrial Technologies (OIT), which shares the cost of developing and implementing technologies that promise to save energy, reduce emissions, and increase productivity of the US steel industry. The OIT signed a compact with the American Iron and Steel Institute and the Steel Manufacturers' Association in May 1995 to collaborate with the U.S. steel industry on three critical research and development areas: process efficiency, recycling, and environmental engineering. Researchers at Oak Ridge National Laboratory in Tennessee developed the nickel aluminide alloy for the rollers, which were centrifugally cast by Sandusky International in Sandusky, OH. This material has superior temperature resistance, which gives it longer service life in the annealing furnace than conventional stainless steel. A phosphor-based sensing technology being tested at Burns Harbor will enable steelmakers to accurately measure the temperature of highly reflective steel strips whose emissivity can skew the readings of optical pyrometers.
PDM Moves to the Mainstream
Authors: Miller Ed
Published: July 2018

Product data management (PDM) has proven its value as a critical tool in handling the enormous amounts of technical information companies generate. Now the PDM industry is applying this experience to more affordable systems targeted at smaller organizations. Several suppliers have entered the market with economical approaches aimed specifically at midsized companies. Many companies use PDM to eliminate inefficiencies in the engineering change process. Diebold, Inc. reduced engineering change cycle time by 30 percent through process automation with PDM. IBM is using PDM technology in product development for sharing data among groups, designing tools tightly coupled with release and change processes, interfacing with procurement and other services, and establishing real-time communication of data across the enterprise. Engineers increasingly are using PDM viewing features to track subsystems. Virtual-mockup capabilities enable engineers to import all the parts files for a product designed in Solid Edge, regardless of computer-aided design (CAD) vendor or file format.
Keeping Virtual Products On Track
Authors: Beally Bruce
Published: July 2018

Product data management (PDM) has helped engineers shrink the time needed to develop a new cross-country motor coach called Renaissance. Engineers used virtual prototypes to confirm that movable parts in the motor coach would fit properly and to identify interferences before physical prototypes were built. The Renaissance uses some highly innovative technology. It is the only cross-country motor coach built in North America to feature six-wheel anti-lock disc brakes for speedy stops and a steering tag axle that greatly improves manoeuvrability. Motor Coach management believes that the use of computer design eliminated some of the costs associated with building and rebuilding portions of the prototype. It also reduced the cycle time considerably. The entire project, from concept to customer deliveries, took 39 months. The PDM system helped engineers by allowing them to see the association of their files with their designs. Solid modeling and PDM helped engineers slash the Renaissance's parts count by 60 percent, reduce suppliers from 53 to 48, and cut build hours by 45 percent.
The Art of Aerospace Composites
Authors: Morrison Gale
Published: July 2018

This article reviews the advanced resin transfer molding (RTM) process of GKN Westland Aerospace. This process is refined enough, with customized equipment and a proprietary resin binding material, so that hundreds of different aircraft parts that would otherwise be heavier (made of titanium) are being produced for customers that include GE, Pratt & Whitney, Lockheed Martin, and Boeing. GKN is making five-axis, hollow vein, and integrated attachment nodes. It has produced carbon-fiber and resin components as thick as 3½ inches, and designs can combine what were many parts. Depending on the part and desired strength (in the desired directions), the fiber tow is woven in a variety of ways. For strength in mainly one direction, the engineers specify that 75 percent of the tow runs in one direction and just 25 percent of it is used to weave across it, for example. The next step in GKN’s advanced RTM evolution is a unihybrid composite that takes great loads in just one direction and can be made very thick, up to 3½ inches. A slightly less rigorous process has already been licensed, to a company in Mexico that produces a component for the Dodge Viper sports car.
Quiet! Okay, But How?
Authors: Zaher M.A.
Published: July 2018

This article focuses on pneumatic tools that are among the most damaging sources of noise pollution. The National Institute for Occupational Safety and Health estimates that more than 30 million workers in the United States are exposed to hazardous noise, costing the economy about $1 billion every year. There is no magic solution to all noise control problems, and this remains true even when we are dealing just with pneumatic tools. Each case must be considered separately, and the solution to be used must satisfy the often conflicting demands of at least five criteria simultaneously. The sound power level produced by a pneumatic tool is a product of many interrelated parameters: operating pressure, pressure drop, expansion volume, exhaust air velocity, speed of device, exhaust air, airflow, length of exhaust path, and tool power. Good standards are available for evaluating the noise of many components, and suppliers provide data on their products that can be used for comparison.
Upgrading the Old Turbinee
Authors: Valenti Michael
Published: July 2018

This article focuses on today’s industrial gas and steam turbines that are designed to be more energy efficient, more reliable, and longer lived than their predecessors. Many of the older models still have plenty of life left in them, though, and turbine operators would have to pay many millions of dollars to replace their old turbines with new ones. Ultraviolet flame detection systems rendered unreliable due to age were replaced by a parametric flame detection system designed by Dresser-Rand Control Systems. The new system uses all 16 of its thermocouples to detect flame in the four gas generator combustors, making use of an algorithm that identifies temperature increases during startup. Structural Integrity has provided its creep monitoring system as a permanent installation, but will offer an offsite monitoring program to broaden the system’s appeal to utilities looking to trim personnel. Future turbine control upgrades will rely on more integrated controls, which treat plant operation as a complete system rather than as individually distinct machine controls.
Making the Most of Aluminum Scrap
Authors: DeGaspari John
Published: July 2018

This article highlights features of a process under-development that aims to recover wrought alloys for high-value applications. Chemically etched wrought aluminum scrap pieces have been separated into their respective alloy families using an optical identification system that is being developed by Alcoa. The technique has successfully completed proof-of-concept testing at Pacific Northwest National laboratory. One method of separating the mix of wrought aluminum into its alloy families combines chemical etching with an optical technique to sort the aluminum by color. John Green, vice president of technology of The Aluminum Association, believes these technologies will give automotive companies an incentive to commit to aluminum for sheet applications by ensuring that recycling wrought aluminum into higher-value applications is feasible. According to an expert, since processing recycled aluminum takes only 5 percent of the energy required to work from primary ingot, using recycled aluminum makes sense for automobiles.
DFMA to RP, ASAP
Authors: Raplee Jack
Published: July 2018

Manufacturing companies are turning increasingly to rapid prototyping (RP) to perform pre-assembly testing and improve the quality of the final product. Manufacturers also have begun to complement their RP practices using design for manufacture and assembly methodology. Design for assembly lowers the complexity of products through parts reduction and enables manufacturers to quantify assembly times and costs. Users are prompted to consider each part and decide if it must be separate from others in the assembly, leading to systematic simplification of design. The four approaches by which design for manufacturer (DFMA) software analyzes product configurations incorporate design for assembly, design for manufacture, design for service, and design for environment. Using design for assembly can reduce the number of parts in the product, but can increase the complexity of the parts that remain. Rapid prototyping combined with DFMA tools not only can determine if a product will perform its desired functions. According to an expert, when early manufacturing process planning is performed using DFMA and RP, it is synergistic.
Out of Harm’s Way
Authors: DeGaspari John
Published: July 2018

GageTek LLC in Rancho Cordova, CA, is working on a load cell to make the air bag safer for the passenger at risk. The company has designed a system consisting of torsion-sensing load cells that calculate the weight as well as the position of the passenger. A load cell, shown on a motorized seat with side air bag in the article, measures the weight and position of front-seat car passengers to help minimize the risk of air bag-related injuries. The load cells are placed at each corner of the seat. The position of the occupant is calculated by determining the passenger’s center of mass. Position sensing is accurate to several centimetres. GageTek ‘s load cell, which it calls a torsional sensing load cell (TSLC), is a U-shaped piece of metal that acts like a spring. The load cell works the way a spring does, by converting linear force to a torsional force, or twisting, at the other end. The TSLCs are placed at each corner of the seat. Calculation of the center of gravity, or position of the occupant, is done by determining the seat occupant’s center of mass.
Pocket-size PEMs
Authors: Sharke Paul
Published: July 2018

A recent study by Joan Ogden at Princeton University’s Center for Energy and Environmental Studies tabulated a range of published estimates for the manufacturing costs of mass-produced auto fuel cell systems. The banded-structure membrane fuel cell, from Fraunhofer ISE, draws off voltage at the endplates through an integrated series connection that ties together individual cells. The typical proton exchange membrane (PEM), fuel cell consists of a series of stacked individual cells, with each cell composed of a flow field plate and a membrane electrode assembly. An air breather PEM fuel cell from DCH Technology distributes hydrogen to the flow fields through a central sleeve, while air at atmospheric pressure comes in through the sides. One of the benefits of Manhattan Scientifics’ circuit board approach is the ability of an electrode to act as a ‘preferential molecular filter’. Fraunhofer Institute scientists have been at work on a banded-structure membrane fuel cell. This device holds five-unit cells on a single plate connected as a series circuit.
Figuring Flow
Authors: Hall Tim , Anderson George
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.
Swamp Thing
Authors: Baumgartner Henry
Published: July 2018

This article describes features of phytoremediation. Phytoremediation involves planting beds of wetland vegetation and using them to treat or dewater several types of noxious effluents, including sewage sludge, leachates from landfills, and wastes from chemical plants and oil-drilling operations. According to a video produced by New England Waste Systems, more than 60 municipal wastewater treatment facilities in the United States are using reed beds to treat at least part of their sludge. The reed bed can handle only a certain amount of sludge at any one time. Occasionally, Lloyd’s bed has been overloaded, causing some of the green growth to die off, but with patience and light loading the next few times, the reeds have been able to bounce back. In effect, solar energy is replacing fossil fuels and electricity. The costs, environmental and otherwise, of generating electricity are avoided, and all those chemical additives are kept in their bottles. Proponents say the remaining solid material, when ready to be dug up and disposed of, is far cleaner than waste that has merely been put through a filter press.
The Mechanics of Flight
Authors: Lee J. Lawrence
Published: July 2018

This article illustrates contribution of mechanical engineering in the aviation industry. The most obvious role of the mechanical engineer involves the design of engines. From the Wrights’ four cylinders, 12-horsepower engine, aircraft propulsion has evolved into today’s high-bypass turbofans developing over 90,000 pounds of thrust in some instances. The most visible contribution of mechanical engineers to aviation, engines are far from their only contribution. Changes in the design, construction, and capabilities of increasingly modern aircraft challenged the mechanical engineering in many other regards. The introduction of gas-turbine power required a concurrent revolution in manufacturing, test, and maintenance facilities and techniques at the engine builders. As advancements in aircraft construction and power opened the door to higher and faster flight, virtually every system within the airplane had to become more sophisticated, and new ones had to be devised. Air conditioning systems also changed, both to better suit the gas turbine prime mover and to accommodate wider external temperature extremes.
Tools to Die For
Authors: DeGaspari John
Published: July 2018

This article discusses the rapid solidification process (RSP) which is being developed by Idaho National Engineering & Environmental Laboratory, a US Department of Energy research lab in Idaho Falls. This process drastically lowers the costs and lead times of production tools. In an approach that is radically different from conventional tool making, in which a mold core and cavity are machined from a block of steel, RSP equipment creates a shape by spraying molten metal onto a pattern, faithfully reproducing the pattern's shape, details, and texture. Tools can be completed in as little as three days, and are suitable for both prototyping and production runs. RSP differs significantly from other commercial spray metal techniques, broadly known as thermal spray. RSP tooling can undergo either conventional heat treatment or low-temperature heat treatment known as artificial aging. Artificial aging allows the tailoring of steel properties, such as hardness, toughness, and thermal heat resistance, without the risk of tool distortion.