bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of core–shell nanocomposites with enhanced photocatalytic efficacy
Authors: Al‐Hussaini Ayman S , Eltabie Kareem R , Hassan Mohamed ER
Published: June 2018

The current study establishes the unprecedented involvement in the evolution and production of novel core–shell nanocomposites composed of nanosized titanium dioxide and aniline‐o‐phenylenediamine copolymer. TiO2@copoly(aniline and o‐phenylenediamine) (TiO2@PANI‐o‐PDA) core–shell nanocomposites were chemically synthesized in a molar ratio of 5:1 of the particular monomers and several weights of nano‐TiO2 via oxidative copolymerization. The construction of the TiO2@PANI‐o‐PDA core–shell nanocomposites was ascertained from Fourier transform IR spectroscopy, UV–visible spectroscopy and XRD. A reasonable thermal behavior for the original copolymer and the TiO2@PANI‐o‐PDA core–shell nanocomposites was investigated. The bare PANI‐o‐PDA copolymer was thermally less stable than the TiO2@PANI‐o‐PDA nanocomposites. The core–shell feature of the nanocomposites was found to have core and shell sizes of 17 nm and 19–26 nm, respectively. In addition, it was found that the addition of a high ratio of TiO2 nanoparticles increases the electrical conductivity and consequently lowers the electrical resistivity of the TiO2@PANI‐o‐PDA core–shell nanocomposites. The hybrid photocatalysts exhibit a dramatic photocatalytic efficacy of methylene blue degradation under solar light irradiation. A plausible interpretation of the photocatalytic degradation results of methylene blue is also demonstrated. Our setup introduces a facile, inexpensive, unique and efficient technique for developing new core–shell nanomaterials with various required functionalities and colloidal stabilities. © 2018 Society of Chemical Industry
Quantitative Crotonylome Analysis Expands the Roles of p300 in the Regulation of Lysine Crotonylation Pathway
Authors: Huang He , Wang Dan‐Li , Zhao Yingming
Published: June 2018

Lysine crotonylation (Kcr) is a recently identified post‐translational modification (PTM) that is regulated by an acetyltransferase, p300. The p300‐catalyzed histone Kcr is able to stimulate transcription to a greater degree than the well‐studied histone lysine acetylation (Kac). Despite these progresses, the global Kcr substrates regulated by p300 remain largely unknown, hindering efforts to establish mechanistic links between Kcr and p300‐mediated phenotypes. Here, a quantitative proteomics study to characterize the p300‐regulated lysine crotonylome is reported. A total of 816 unique endogenous crotonylation sites are identified across 392 proteins, with 88 sites from 69 proteins being decreased by more than 0.7‐fold (log2 < 0.5) and 31 sites from 17 proteins being increased by more than 1.4‐fold (log2 > 0.5) in response to p300 knockout (KO). The most downregulated crotonylome alterations under p300 deficiency concern components of the nonsense‐mediated decay, infectious disease, and viral/eukaryotic translation pathways. Moreover, some p300‐targeted Kcr substrates are potentially linked to diseases such as cancer. Taken together, this study reveals the lysine crotonylome in response to p300, which sheds light on the role for lysine crotonylation in regulation of diverse cellular processes and provides new insights into mechanisms of p300 functions.
Platelet Releasate Proteome Profiling Reveals a Core Set of Proteins with Low Variance between Healthy Adults
Authors: Parsons Martin E. M. , Szklanna Paulina B. , Guerrero Jose A. , Wynne Kieran , Dervin Feidhlim , O'Connell Karen , Allen Seamus , Egan Karl , Bennett Cavan , McGuigan Christopher , Gheveart Cedric , Ní Áinle Fionnuala , Maguire Patricia B.
Published: June 2018

Upon activation, platelets release a powerful cocktail of soluble and vesicular signals, collectively termed the "platelet releasate" (PR). Although several studies have used qualitative/quantitative proteomic approaches to characterize PR; with debated content and significant inter‐individual variability reported, confident, and reliable insights have been hindered. Using label‐free quantitative (LFQ)‐proteomics analysis, a reproducible, quantifiable investigation of the 1U mL−1 thrombin‐induced PR from 32 healthy adults was conducted. MS proteomics data are available via ProteomeXchange, identifier PXD009310. Of the 894 proteins identified, 277 proteins were quantified across all donors and form a "core" PR. Bioinformatics and further LFQ‐proteomic analysis revealed that the majority (84%) of "core" PR proteins overlapped with the protein composition of human platelet‐derived exosomes. Vesicles in the exosomal‐size range were confirmed in healthy‐human PR and reduced numbers of similar‐sized vesicles were observed in the PR of a mouse model of gray platelet syndrome, known to be deficient in platelet alpha‐granules. Lastly, the variability of proteins in the PR was assessed, and reproducible secretion levels were found across all 32 healthy donors. Taken together, the PR contains valuable soluble and vesicular cargo and has low‐population variance among healthy adults, rendering it a potentially useful platform for diagnostic fingerprinting of platelet‐related disease.
Mechanistic and kinetic study on the reaction of Furan with O(3P)
Authors: Zhang Yunju , Sun Yuxi
Published: June 2018

The ab initio and DFT methods together with the multichannel RRKM‐TST theories with the FORTRAN code were employed to investigate the mechanisms and kinetics of Furan + O(3P) reaction. Eight product channels (2 H‐abstraction product channels and 6 addition/elimination product channels) have been identified, and the addition/elimination is dominant both thermodynamic and kinetic consideration. The major channels are the O(3P) addition to the (α)‐C and (β)‐C atom of Furan to form IM1 and IM2, and then dissociate to P1 + H and P4 + H by breaking (α)‐C―H and (β)‐C―H bond, respectively. The rate constants vary with temperature, and the total rate constants exhibit positive temperature dependence. The calculated results indicated that the total rate constants were not affected by pressure and the individual rate constants were affected by pressure.
Compressed 3D Image Information and Communication Security
Authors: Yang Chengshuai , Ding Yuyang , Liang Jinyang , Cao Fengyan , Qi Dalong , Jia Tianqing , Sun Zhenrong , Zhang Shian , Chen Wei , Yin Zhenqiang , Wang Shuang , Han Zhengfu , Guo Guangcan , Wang Lihong V.
Published: June 2018

Ensuring information and communication security in military messages, government instructions, scientific experiments, as well as in personal data processing, is critical. In this study, a new hybrid classical–quantum cryptographic scheme to protect image information and communication security is developed by combining a quantum key distribution (QKD) and compressed sensing (CS). This method employs a QKD system to generate true random codes among the remote legitimate users and utilizes these random codes to encrypt and decrypt compressed 3D image information based on the CS algorithm. Therefore, this new technique can provide computational security in the image information transmission process by the encryption and decryption of CS algorithm, and the information and communication security can be evaluated in real time by monitoring the QKD system. Furthermore, this technique can directly transmit and reconstruct the compressed 3D image information based on the modified TwIST algorithm, and thus fewer random codes are required in QKD system, which can improve the information transmission bandwidth. Consequently, this technique not only provides a new application of a QKD system but also extends the CS‐based image reconstruction from 2D to 3D. This study may open a new opportunity in the field of information and security communication.
Global stabilization of a class of cascaded systems with upper‐triangular structures
Authors: Lan Qixun , Ding Shihong , Li Shihua
Published: June 2018

In this paper, the global stabilization problem of a class of cascaded systems with upper‐triangular structures is considered. On the basis of the forwarding technique, a series of virtual controllers are recursively constructed for the driving subsystem. According to the mild assumption imposed on the driven subsystem, a partial‐state feedback controller is obtained for the entire cascaded nonlinear system by developing a delicate design fashion. It is shown that the obtained state feedback controller will render the entire cascaded nonlinear system globally asymptotically stable. Numerical examples are conducted to validate the proposed control scheme.
Identity negotiation within peer groups during an informal engineering education program: The central role of leadership‐oriented youth
Authors: Pattison Scott A. , Gontan Ivel , Ramos‐Montañez Smirla , Moreno Lauren
Published: June 2018

As part of ongoing efforts to support a diverse and robust engineering workforce and ensure that children and adults from all communities have the engineering and design thinking skills to succeed in a science, technology, engineering, and mathematics (STEM)‐rich world, identity has become a growing focus of research and education efforts. To advance our understanding of engineering‐related identity negotiation within informal STEM education contexts, we conducted an in‐depth, qualitative investigation of six adolescent girls participating in an afterschool engineering education program jointly run by two community‐based organizations and a science center. Building on the Identity‐Frame Model developed through our prior work, analysis of videotaped program sessions and secondary data from participants, program facilitators, and parents highlighted the important role that leadership‐oriented youth played in shaping the identity negotiation of participants during the programs, both in the ways they recognized and positioned the situated identities of other youth and through their influence on the activity frames that defined the nature of the engineering activities. These findings extend prior classroom studies and suggest a new lens to help teachers and program facilitators support identity negotiation for youth in STEM education programs.
Persistence of the two‐worlds pitfall: Learning to teach within and across settings
Authors: Braaten Melissa
Published: June 2018

Learning to teach within and across the settings of teacher education coursework and field experience in local schools is subject to the “two‐worlds pitfall,” where practices, norms, expectations, tools, and other aspects of teaching can be jarringly different. This remains an ever‐present dilemma for preservice teachers, their teacher educators, and their school‐based mentors. This collective case study follows two cohorts of secondary science teacher candidates (22 in total) through their field experiences in local schools to understand how they reorganized, repurposed, and retooled practice as they worked on noticing and responding to students using ambitious science teaching principles and practices. Analysis highlights how instructional experiences in K–12 classrooms and relationships with mentors afforded and constrained preservice teachers’ efforts to recontextualize ambitious science teaching practices in the status quo science teaching contexts of local schools. Recommendations for increasing permeability between the two worlds of teacher preparation are included.
Gender disparities in students’ motivational experiences in high school science classrooms
Authors: Patall Erika A. , Steingut Rebecca R. , Freeman Jen L. , Pituch Keenan A. , Vasquez Ariana C.
Published: June 2018

Women remain underrepresented in physical science, engineering, and computer science college majors and careers. Prior research has suggested that motivational beliefs and experiences in high school play a critical role in girls’ persistence in science fields. We hypothesized that compared to male students, female high school students may experience less daily autonomy support from teachers and lower psychological need satisfaction in physics, chemistry, and engineering courses. In turn, we expected that these differences would explain girls’ lower daily engagement in these courses compared to boys. In line with current trends indicating gender parity in biology and biomedical fields, we did not expect to find gender differences in biology courses. Results from a six‐week intensive longitudinal study in which high school students reported their daily experiences of teacher autonomy support, need satisfaction, and engagement during science class supported our hypotheses. The implications of the results for theory and practice are discussed.
XPS study of the SnO2 films modified with Rh
Authors: Korotcenkov G. , Brinzari V. , Hanyš P. , Nehasil V.
Published: June 2018

In this paper, we have analyzed the effect of the rhodium surface modification on the surface state of SnO2 films. SnO2 films, subjected for the surface modification, were deposited by spray pyrolysis, while Rh was deposited by using a microelectron beam evaporation. The thickness of the Rh coating varied in the range 0 to 0.1 monolayer. An explanation of the observed effects was proposed. Basing on the results of X‐ray photoelectron spectroscopy, it was assumed that at a small thickness of the rhodium covering, Rh was in a the well‐dispersed state, close to atomically dispersed state. The growth in the size of the nanoparticles began mainly when the thickness of the Rh covering exceeeded 0.01 monolayer. The size of clusters did not exceed 0.5 to 1.0 nm.
The improvement in interfacial shear strength of wood fiber/epoxy composite by sizing with epoxy sizing agent containing MWCNTs
Authors: He Runqin , Chang Qiuxiang , Peng Chunzheng
Published: June 2018

This paper discloses a feasible and high efficient strategy for wood fiber treatment to introducing multi‐wall carbon nanotubes (MWCNTs) to the surface of wood fibers for the aim of improving the interfacial shear strength of wood fiber/epoxy composite. Briefly, a layer of MWCNT was deposited on wood fibers through sizing wood fibers with epoxy sizing agent containing amine‐treated MWCNTs (MWCNT‐PEI). The surface functional groups, morphology, wettability, and interphase properties of MWCNTs on the surface of wood fiber were studied. The remarkable enhancements were achieved in interfacial shear strength of reinforced composites by dipping wood fiber in MWCNTCOOH suspension and wood fiber sizing containing MWCNT‐PEI.
The oscillatory adsorption of self‐assembled organosilane films on aluminium oxide surfaces
Authors: Sims R. A. , Harmer‐Bassell S. L. , Quinton J. S.
Published: June 2018

The time‐dependent oscillatory growth mechanism of organosilane film self‐assembly on aluminium oxide has been investigated using X‐ray photoelectron spectroscopy. While this unusual oscillatory process has been reported for the trifunctional silane, propyltrimethoxysilane, we report here, for the first time, that this oscillatory behaviour is also present during the self‐assembly of the difunctional silane propylmethyldimethoxysilane. The presence of multiple oscillations in this growth mechanism is also first reported for propyltrimethoxysilane and propylmethyldimethoxysilane as a function of exposure time. Multiple oscillations indicate that the 3‐component model that is used to describe and fit a single coverage oscillation must be reconsidered and contain additional components to account for the multiple oscillations seen experimentally. The absence of such oscillatory behaviour in the growth of the monofunctional organosilane propyldimethylmethoxysilane, which in fact follows a Langmuir‐type growth mechanism, indicates that this measurable oscillatory behaviour is because of the ability of multifunctional silanes to oligomerise both on the substrate and in solution.
State‐level estimation of diabetes and prediabetes prevalence: Combining national and local survey data and clinical data
Authors: Marker David A. , Mardon Russ , Jenkins Frank , Campione Joanne , Nooney Jennifer , Li Jane , Saydeh Sharon , Zhang Xuanping , Shrestha Sundar , Rolka Deborah
Published: June 2018

Many statisticians and policy researchers are interested in using data generated through the normal delivery of health care services, rather than carefully designed and implemented population‐representative surveys, to estimate disease prevalence. These larger databases allow for the estimation of smaller geographies, for example, states, at potentially lower expense. However, these health care records frequently do not cover all of the population of interest and may not collect some covariates that are important for accurate estimation. In a recent paper, the authors have described how to adjust for the incomplete coverage of administrative claims data and electronic health records at the state or local level. This article illustrates how to adjust and combine multiple data sets, namely, national surveys, state‐level surveys, claims data, and electronic health record data, to improve estimates of diabetes and prediabetes prevalence, along with the estimates of the method's accuracy. We demonstrate and validate the method using data from three jurisdictions (Alabama, California, and New York City). This method can be applied more generally to other areas and other data sources.
Morphology and phylogenetic relationships of fossil snake mackerels and cutlassfishes (Trichiuroidea) from the Eocene (Ypresian) London Clay Formation
Authors: Beckett Hermione T. , Giles Sam , Johanson Zerina , Friedman Matt
Published: June 2018

‘Gempylids’ (snake mackerels) and trichiurids (cutlassfishes) are pelagic fishes characterized by slender to eel‐like bodies, deep‐sea predatory ecologies, and large fang‐like teeth. Several hypotheses of relationships between these groups have been proposed, but a consensus remains elusive. Fossils attributed to ‘gempylids’ and trichiurids consist almost exclusively of highly compressed body fossils and isolated teeth and otoliths. We use micro‐computed tomography to redescribe two three‐dimensional crania, historically assigned to †Eutrichiurides winkleri and †Progempylus edwardsi, as well as an isolated braincase (NHMUK PV OR 41318). All from the London Clay Formation (Eocene, Ypresian), these specimens represent some of the oldest fossils identified as trichiuroids. We find that †Eutrichiurides winkleri does not show diagnostic characters of †Eutrichiurides, and it is assigned to a new genus. To investigate the placement of these fossils relative to extant lineages, we combine existing morphological character sets for ‘gempylids’ and trichiurids along with published mitogenomic data. Our analyses recover a monophyletic Trichiuridae nested within a paraphyletic ‘Gempylidae’. The taxon formerly known as †Eutrichiurides winkleri is considered Trichiuroidea incertae sedis, while †Progempylus edwardsi and NHMUK PV OR 41318 are recovered within the ‘gempylid’ grade. Using previously published descriptions and character optimizations from our phylogenetic analyses we suggest possible placements for laterally compressed body fossils assigned to Trichiuroidea (†Argestichthys, †Abadzekhia, †Chelifichthys, †Anenchelum, †Eutrichiurides, †Musculopedunculus).
Opening the Selectivity Pocket in the Human Lysine Deacetylase Sirtuin2 – New Opportunities, New Questions
Authors: Robaa Dina , Monaldi Daria , Wössner Nathalie , Kudo Norio , Rumpf Tobias , Schiedel Matthias , Yoshida Minoru , Jung Manfred
Published: June 2018

Reversible lysine deacetylation is exerted by both zinc and NAD+‐dependent deacetylases. It is an important factor in epigenetic regulation and more generally in the posttranslational regulation of protein stability, association and activity. Some of these enzymes can also cleave off fatty acids or dicarboxylic acids from lysines in proteins. The NAD+‐dependent deacetylases are termed Sirtuins and are implicated in the pathogenesis of different diseases. For the isotype Sirt2 highly selective inhibitors have been identified in the last few years. Many of those Sirt2 selective compounds, like the Sirtuin rearranging ligands (SirReals) discovered in our group, have been shown or are postulated to bind to the so‐called selectivity pocket. This binding site is not observed in crystal structures of the apo‐enzyme but can be opened up by long chain fatty acid substrates respectively suitable inhibitors. Recently, this unique feature of Sirt2 was exploited to provide highly potent and selective tools for the chemical biology of Sirtuins. Here, we shortly review Sirtuin biology, present inhibitors that have either been confirmed or postulated to bind to the selectivity pocket, their applications and an outlook regarding mechanistic investigations.
A new domain adaption algorithm based on weights adaption from the source domain
Authors: Lu Nannan , Chu Fei , Qi Haoran , Xia Shuang
Published: June 2018

Domain adaption is effective for utilizing the knowledge from a source domain to benefit further learning task in a different but related target domain. It mainly reduces the difference across domains by learning a shared feature representation. So, it also could be taken as a feature transfer algorithm. Besides, another transfer technique, named instance transfer, allows the instances from a source domain to be reused in a target domain by reweighting. Each method has two facets. Instance transfer must satisfy the high similarity between the source domain data and the target domain data, while domain adaption ignores the difference of contributions by the different instances. In this paper, a new domain adaption algorithm is proposed to introduce weights adaption into the feature representation. Specifically, it aims to reweight the instances in new feature space and adapt the distributions across the different domains. In distribution adaption, both the marginal distribution and the conditional distribution are simultaneously adjusted in the unified framework. In this way, the new feature representation is effective for the substantial distribution difference as well as instance difference. The experiments on 36 groups of image datasets show that the knowledge of the source domain is efficiently transferred to classify the target domain. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Community perceptions of climate change and initiatives for the conservation of endemic plants in Limpopo Province, South Africa
Authors: Rankoana Sejabaledi A.
Published: June 2018

This study was conducted to examine how climate change is perceived by a rural community in Limpopo Province, South Africa, and to investigate how such changes affect endemic plant species upon which community members depend for their livelihoods. The initiatives employed by community members to preserve endemic plants which have cultural value are also examined. The results of the study were obtained from semi‐structured interviews with traditional health practitioners and other community members. It was found that participants’ perceptions of the current state of climate change were linked to their observations of changes in temperature and rainfall patterns. Interviewees reported having experienced rising temperatures in the form of an increased frequency of excessively hot summers, as well as warmer winters. Rainfall was described as scarce, and rain episodes were characterised by more frequent thunderstorms. These observations have been confirmed in an independent analysis of meteorological observations by Ziervogel et al. (2014), who found that the mean annual temperature has increased by at least 1.5‐fold over the past five decades, and that extreme rainfall events have increased in frequency. The consequences of these changes in temperature and rainfall are significant and mostly negative, including poor plant growth, the withering of immature plants and the total loss of some useful species. However, members of this rural community have adopted indigenous conservation practices to limit the risk of indigenous plant loss and to maintain their cultural usage. Conservation practices adopted in the study area include the observance of cultural taboos, as well as other traditional customs, which restrict the harvesting and collection of useful plant materials.
Glial acetate metabolism is increased following a 72-h fast in metabolically healthy men and correlates with susceptibility to hypoglycemia
Authors: McDougal David Harry , Darpolor Moses Morakortoi , DuVall Marina Andreyevna , Sutton Elizabeth Frost , Morrison Christopher David , Gadde Kishore Murali , Redman Leanne Maree , Carmichael Owen Thomas
Published: June 2018

Aims

Prior exposure to insulin-induced hypoglycemia was shown to increase glial acetate metabolism (GAM) during subsequent exposure to hypoglycemia in diabetic individuals. However, it remained unclear whether this effect was dependent on the disease state or the antecedent cause of hypoglycemia. We aimed to establish whether exposure to fasting-induced hypoglycemia was sufficient to produce alterations in GAM in non-diabetic individuals.

Methods

GAM was measured via carbon-13 magnetic resonance spectroscopy during infusion of [1-13C] acetate before and after a 72-h fast in six metabolically healthy men. All participants were male, aged 18–40 years, with a Body Mass Index of 20.0–27.9 kg/m2, who consented to reside at Pennington Biomedical Research Center for 4 days. The main outcome measure was the percent enhancement of cerebral [1-13C] bicarbonate (the primary metabolic byproduct of glial oxidation of [1-13C] acetate). Continuous glucose monitoring was used to measure hypoglycemic episodes during the 72-h fast.

Results

As expected, 72 h of fasting significantly reduced blood glucose levels and resulted in a high frequency of hypoglycemic episodes. Steady-state GAM increased from 53.5 ± 3.7 to 61.9 ± 1.7% following the 72-h fast (p = 0.005). This increase correlated with greater duration of hypoglycemia experienced during the fast (r = 0.967). In addition, subjects with greater GAM at baseline experienced a greater increase in the duration of hypoglycemia experienced during the 72-h fast (r = 0.979).

Conclusions

GAM has potential as a biomarker for susceptibility to hypoglycemic episodes.

Trail registration

Clinicaltrials.gov ID: NCT02690168.
On Carrot Cake and Marketing Education: A Perspective on Balancing Skills for Employability
Authors: Daellenbach Kate
Published: June 2018

The current climate for marketing education demands a complex set of skills for our graduates: critical and creative thinking, good communication skills, marketing knowledge, and specific technical skills. In addition, knowledge is far more readily available outside the formal university institution. In response, marketing educators need to address these demands. Based on existing literature, this paper proposes four categories of skills: thinking and learning skills, personal soft skills, marketing knowledge and technical skills. A metaphor is presented as a means through which the co-existence of these skills may be conceptualised. With this view, thinking and learning and personal soft skills are at the core, into which marketing knowledge is learned and applied. Technical skills are added but with caution, ensuring that they are placed in the context of marketing knowledge, and help to develop thinking and learning, and personal soft skills. Implications and suggestions are provided for educators as we plan programmes, courses and lectures. A challenge is also presented to the wider Academy to create a standardised designation which acknowledges these skills.
From Pre-Colonial Past to the Post-Colonial Present: The Contemporary Clan-Based Configurations of Statebuilding in Somalia
Authors: Ingiriis Mohamed Haji
Published: June 2018

This article is driven by an empirical paradox over where Somalia came from (pre-colonial clan-states) and where it ended up (return to pre-colonial clano-territorial conflicts). Existing academic studies on contemporary Somalia, which were supposed to provide critical analysis, continue to applaud the creation of clan-states within the failed state of Somalia. Based on a variety of unique primary sources, this article offers a new perspective on the current state formation processes occurring in the purview of the Somali State. Somali clans are determined to come to terms with the state collapse by averting the return to political power of the detested military regime, which was led by one clan-based leadership that tended to terrorize other rival clans and denied any equal power- and resource-sharing framework. Conceptualizing the contemporary Somali state as similar to pre-colonial clan-sultanates, this article argues that contemporary Somalis are reverting to a pre-colonial realm where each clan had its clan sultan seeking for a clan-state of its own right. Where else do clan-states compete against each other in entering into “treaties” with external entities intent on exploiting war-torn Somalia astabula rasa? It is towards the objective of answering this question and of providing a better understanding of the Somali conflict that this article is offered to add a comparative empirical understanding of the different trajectories of state formations in Somalia.
Analysis of microscopic properties of radiative shock experiments performed at the Orion laser facility
Authors: Rodríguez R. , Espinosa G. , Gil J. M. , Suzuki-Vidal F. , Clayson T. , Stehlé C. , Graham P.
Published: June 2018

In this work we have conducted a study on the radiative and spectroscopic properties of the radiative precursor and the post-shock region from experiments with radiative shocks in xenon performed at the Orion laser facility. The study is based on post-processing of radiation-hydrodynamics simulations of the experiment. In particular, we have analyzed the thermodynamic regime of the plasma, the charge state distributions, the monochromatic opacities and emissivities, and the specific intensities for plasma conditions of both regions. The study of the intensities is a useful tool to estimate ranges of electron temperatures present in the xenon plasma in these experiments and the analysis performed of the microscopic properties commented above helps to better understand the intensity spectra. Finally, a theoretical analysis of the possibility of the onset of isobaric thermal instabilities in the post-shock has been made, concluding that the instabilities obtained in the radiative-hydrodynamic simulations could be thermal ones due to strong radiative cooling.
Show Me the Data! Improving Evidence Presentation for Publication
Authors: Greve Henrich R.
Published: June 2018

Management journals publish research that can be divided into many fields and originate from many theories, but in one regard all are similar: the presentation of data according to professional conventions. The presentation of empirical findings expresses broad agreement across theories, fields of study, and researcher background, an agreement that is upheld by doctoral training and by scholars learning presentation conventions through reading journal articles. The agreement is most easily uncovered by examining empirical papers in other fields of study, which quickly yields two conclusions. First, the fields are different from the management field; second, many of them have greater internal diversity in evidence presentation than management does. In particular, empirical articles outside management use more graphical displays to show the data in addition to showing model estimates, and have a great variety of graphing techniques.
Mediaeval kites and Windsocks
Authors: Hart Clive
Published: June 2018

We have grown used to the idea that in the Middle Ages inventors produced several forerunners, either real or imaginary, of modern aerodynamic devices. The helicopter was designed, in principle, before Leonardo, while the rigid aerofoil, in the form of the plane-surface kite, achieved a remarkable degree of sophistication before the end of the sixteenth century. It has commonly been assumed that among these mediaeval inventions we should include some sort of three-dimensional kite, a precursor of Hargrave's box-kite, either in the form of a windsock equipped with wings, or in that of a primitive hot-air balloon, with or without additional lifting force provided by wings. I wish to examine the evidence for the existence of these objects, and to make a fresh assessment of the likelihood of their ever having flown.
Transport Flying-Boats
Authors: Shenstone B. S.
Published: June 2018

When I was young and in my prime,The Boats were flying all the time.But now that I am old and gray,Those Boats, like me, have had their Day.

The first time I saw flying-boats close-up was in 1928. The first was an old Curtiss HS2L being used in Tima-gami for forest fire patrol in northern Canada. Designed in about 1916, this antique was at the end of its tether, but was doing a job that no other aircraft could do until a replacement became available. The second flying-boat I saw was this replacement, the Canadian Vickers Vedette, another single-engined pusher biplane, but a much better one.
Some Recent Studies of the Buckling of Thin Shells
Authors: Hoff N. J.
Published: June 2018

The purpose of this paper is to summarise some recent results obtained at Standford University regarding the buckling of thin shells. A detailed review of work done by other investigators will not be given here because this was done recently in two papers written by the author. However, a few important steps in the evolution of our knowledge of the buckling of thin .shells will be mentioned to put the new results in proper perspective.
Electric Propulsion Development
Authors: Openshaw P. R.
Published: June 2018

Parts I and II of this series of papers have dealt with the development of ion thrusters for use in an orbit transfer manoeuvre, and of various types of micro thruster for position and attitude control. The present paper deals with the actual satellite electric propulsion system and configuration needed for expansion manoeuvres. The control problems both during the expansion phase and subsequently in the required orbit are discussed. Short analyses for two specific cases (ELDO launcher and Black Arrow) are presented in which payloads and missions are defined.

Burt has shown that all the orbital elements of a spacecraft can be changed by means of a small continuous thrust. He gave particular attention to the problem of expanding from a low orbit to a synchronous one, and the change of orbit inclination and orbit eccentricity was also considered. Such a type of manoeuvre is eminently suitable to electric propulsion because the high exhaust velocities possible lead to a small propellant mass; this mass saving is achieved at the expense of the time taken for the manoeuvre.
Two and Three-Dimensional Flow using Finite Elements
Authors: Argyris J. H. , Mareczek G. , Scharpf D. W.
Published: June 2018

The method of finite elements is in certain cases advantageous when dealing with flow problems in a finite domain. This is particularly so when attempting to include subcritical compressibility effects.

In the present note we first consider the two-dimensional flow using TRIC and TRIM-like triangular elements in conjunction with the concept of the stream function, which is assigned to the nodal points of the elements. The application of the stream function allows a direct and exact satisfaction of the boundary conditions. Strictly the elements in question could also be used in conjunction with the potential function but the observance of the boundary conditions is then cumbersome.
Wing Vibration Problems in Hovering Auto-Stabilised VTOL Aircraft
Authors: Kirk C. L. , Pitt A. J.
Published: June 2018

A VTOL aircraft which is in a state of hovering flight possesses no inherent stability of its own, consequently it may be found necessary to introduce some artificial form of control of the aircraft in both rolling and pitching motion. Such a control device may consist of an auto-stabiliser which enables the pilot to maintain the aircraft in a state of stationary hover, or to perform some manoeuvre by rolling or pitching the aircraft. This paper investigates the wing vibration problems associated with the roll attitude control of a transport aircraft in which the jet-lift engines are mounted in pods situated on the wings. Fig. 1 illustrates diagrammatically a typical transport aircraft configuration in which there are sixteen jet-lift engines mounted in two pods, one on either wing, each pod containing eight lift-engines.
A Review of Engineering Developments in Helicopter Design
Authors: Speechley J.
Published: June 2018

One of the most interesting aspects of the aeronautical endeavours of Henson and Stringfellow was their awareness of the impact of the aeroplane as part of an overall transport system. It is all too easy in the field of aeronautical engineering to become mesmerised by the engineering intricacies of what one is doing and so fail to see the vehicle as part of this overall system concept.

In many respects we have, I think, been able to avoid this inward thinking in the helicopter since its vertical flight capability has become intimately bound up with considerations of its operational duties.
The Next Generation of French Helicopters
Authors: Legrand L. F.
Published: June 2018

It is a great honour for me to present this lecture as a tribute to the memory of La Cierva.

In my opinion, La Cierva was more than a pioneer who designed practical rotor-craft: he was, above all, the engineer who tried to understand how these machines worked and what is more remarkable, he sometimes succeeded! I am afraid that this attitude of mind has been somewhat forgotten since La Cierva, but the manufacturers willing to survive should now follow his example.

I have been asked to present the next generation of French helicopters but it would be more appropriate to speak of the next generation of Anglo-French helicopters. For, as you know, the models of the near future are being developed and produced under the terms of a co-operation agreement concluded between our two Governments. Other lecturers, with better qualifications, have already emphasised the “pros” and “cons” of these international programmes.
Man-Powered Flight—A New Approach to an Old Dream
Authors: Richmond S.
Published: June 2018

There is an old saying in the aircraft industry that you can make a brick fly, if you give it enough power. How true this is I would not care to say, but it is certainly true that the worries of the designer are lessened if he knows that he can always give the throttle a little extra push, if all else fails.

This is not to say that the design of a conventional, high powered, aircraft is a simple, hit or miss affair, that would be ridiculous, but it does serve to show the special difficulties faced by the builders of a man-propelled aircraft who have less power available to them than is used by a small electric fire.
Airport Problems in Flight Operations
Authors: Killip E. L.
Published: June 2018

Current ICAO standards covering the design of airports arise, in many cases, from the problems of flight operations and it would be a waste of time to repeat these. What this paper is intended to do is to discuss, briefly, some aspects which may be new or seen to deserve special emphasis.
The Static Stability of a Cone-Cylinder Flare and Two Cone-Cylinder Fin-Flare Combinations at Supersonic Speed
Authors: Mathur M. C.
Published: June 2018

The Black Brant IV shown in Fig. 1, is a two-stage sounding rocket with a 15KS-25 000 booster motor stabilised with three fins and a 9KS-11 000 motor, a 5·3 fineness ratio conical noise and an 11·5° conical flare forming the second stage. Basically, the second stage is the single stage Black Brant III rocket, but uses a conical flare instead of three fins at the aft end for aerodynamic stability. This paper reviews the static stability of a Black Brant IV second stage with a flare and two fin-flare combinations.
Part II. Some Aspects of the RAE High-lift Research Programme
Authors: Foster D. N.
Published: June 2018

The object of this paper is to illustrate the high-lift research programme at the RAE. It is not intended to be a complete survey of all aspects of this programme, but rather to highlight areas which will stimulate discussion of the programme. Again, it was not intended to consider only completed research work, but rather to illustrate the problems that are being investigated, and the ways in which solutions to these problems are being sought.
Requirements for Future Civil Aircraft
Authors: Brown D. G.
Published: June 2018

Requirements fall into two categories: —

(i) the demands of the market leading to a capacity requirement, which, dependent on the technical solutions, leads to a market requirement in terms of the number of aircraft.

(ii) the technical requirements in terms of the vehicle characteristics required to provide the most competitive aircraft to achieve maximum market penetration.

An appreciation of future civil requirements is presented as seen through the eyes of a project engineer rather than a market research economist. The title of the symposium suggests a focusing of attention on two main fields of air transport, namely, the successors to the supersonic long-range aircraft and the large subsonic short-range aircraft. It is, however, the intention to broaden the survey to cover the major areas of activity in civil aviation, since in many ways there may be inter-relations between the developments in different fields.
Some General Considerations on the Natural Mode Technique
Authors: Argyris J. H. , Scharpf D. W.
Published: June 2018

We continue our fundamental discourse on the natural modes in an element and extend our considerations to large displacements. First, we present a general procedure for establishing the so-called geometrical stiffness kG, when the natural modes of the complete element are given. The theory is a substantial generalisation and clarification of the method initially given in refs. 2 and 3 and shows that in establishing the modification to the transformation matrix aN it is necessary to ignore the contribution of the natural modes, which cause rotation at the nodal points but no displacement there. The point is subtle and was not made in ref. 2, although the applications given there are correct. As an example, the geometrical stiffness of a straight beam in space with all degrees of freedom is established. There follows the extension of the geometrical stiffness concept to a sub-element. This is of great practical significance for two reasons. First, it allows to derive the geometrical stiffness of elements of complex shape and behaviour, e.g. curved beams in space subjected to normal forces, bending moments and torque.
Aerodynamic Design
Authors: Küchemann D.
Published: June 2018

I am very conscious of the great honour of being invited to deliver this fourth Reynolds-Prandtl Lecture. At the same time, I am very pleased. As far as I am concerned, the spirit of these two great scientists is still alive. They are both with me every day—at least, I have pictures of them in my office and I look at them every day. As has been said before, their influence is as strong as ever and many of the problems that engaged their attention are even today only partially solved. However, there is more to it than that. Their example and their work have left me with many other problems to think about, which concern the kind of work we do and the aims we pursue. The present lecture gives me an opportunity to put before you some of the thoughts that occupy my mind and which I should like to be discussed. I feel quite strongly that these problems deserve our attention. It may even be vital for the survival of research in our field to find answers to them, which satisfy not only ourselves but also the society in which we live.
Synthesis of Aircraft Modal Control Systems having Real or Complex Eigenvalues
Authors: Crossley T. R. , Porter B.
Published: June 2018

The theory of modal control is concerned with the design of control loops for systems with governing equations which can be adequately approximated by linear vector-matrix equations of the form

where x is the system state vector, y is the control vector, A is the matrix of the uncontrolled system, and B is the control matrix.
The Advantages of Three-Shaft Turbofan Engines for Civil Transport Operation
Authors: Armstrong J. P. , Jones A. T.
Published: June 2018

The engine parameters which most obviously must improve to contribute to the continued lowering of aircraft Direct Operating Costs are those of prices, weight, volume and fuel consumption. These affect the base-line performance characteristics of the aircraft and in any formula for estimating Direct Operating Costs they will appear in the general cost of flying a load of passengers or freight from A to B.

Engines also unfortunately generate other costs in their own right. These include:

Maintenance labour while mounted on the aircraft.

Repair and overhaul shop labour (including time to remove and re-install the engine).

Replacement parts cost.

Spare engine holding.

Spare parts holding.

Overhaul shop overheads.
Thrust Vector Control by Secondary Gas Injection in Two-Dimensional Nozzles
Authors: Neilson John H. , Gilchrist Alastair , Lee Chee K.
Published: June 2018

When side force is produced by the injection of a secondary gas into the supersonic region of an axi-symmetric nozzle, the body shape of the obstruction caused by the secondary flow induces a cone-shaped separation region upstream of the port. From the apex of the cone a conical shock front is developed. Part of the total side force produced is due to the excess static pressure acting on the nozzle wall in

(a) the separated region, and in

(b) the wall area lying between the separated region and the trace of the shock on the nozzle wall.

In such a field the static pressure is not uniform downstream of the shock but varies from point to point on the nozzle wall areas in question. This aspect of axi-symmetric flow makes attempts to correlate theoretical and experimental work difficult. It was considered that basic information about the important parameters, which influence side force, could best be obtained in experiments with two-dimensional nozzles. Here the circular secondary port is replaced by a rectangular port, the separation zone is wedge-shaped, the shock has a plane front, and in theory, the static pressure is uniform between the port and the point at which the boundary layer separates.
Flow Separation and Stall Characteristics of Plane, Constant-Section Wings in Subcritical Flow
Authors: Chappell P. D.
Published: June 2018

This paper discusses the various aspects of flow separation on wings and aerofoils at subcritical Mach numbers. It is shown that in general the onset of non-linearities in the aerodynamic characteristics, for plane constant-section wings, can be related to the initiation of regions of flow separation somewhere on the wing and often near the wing tip.

Empirical correlations are produced, tor plane wings of constant symmetrical section, enabling estimates to be made of the lift coefficient for onset of separation at either the leading or trailing edge of the wing.

A correlation of stall types on aerofoils, due to Gault, is extended in application to the estimation of initial stall and separation types for plane wings of constant symmetrical section. Suggestions for extending the application of this correlation to the estimation of section stall type for cambered, twisted and non-constant section wings are made.