bluuebunny/crossref_metadata_2025 huggingface dataset:
Filamentary Fragmentation and Accretion in High-mass Star-forming Molecular Clouds
Authors: Lu 吕 Xing 行 , Zhang Qizhou , Liu Hauyu Baobab , Sanhueza Patricio , Tatematsu Ken’ichi , Feng Siyi , Smith Howard A. , Myers Philip C. , Sridharan T. K. , Gu Qiusheng
Published: March 2018

Filamentary structures are ubiquitous in high-mass star-forming molecular clouds. Their relation with high-mass star formation is still to be understood. Here we report interferometric observations toward eight filamentary high-mass star-forming clouds. A total of 50 dense cores are identified in these clouds, most of which present signatures of high-mass star formation. Five of them are not associated with any star formation indicators and hence are prestellar core candidates. Evolutionary phases of these cores and their line widths, temperatures,

abundances, and virial parameters are found to be correlated. In a subsample of four morphologically well-defined filaments, we find that their fragmentation cannot be solely explained by thermal or turbulence pressure support. We also investigate distributions of gas temperatures and nonthermal motions along the filaments and find a spatial correlation between nonthermal line widths and star formation activities. We find evidence of gas flows along these filaments and derive an accretion rate along filaments of ∼10−4 

. These results suggest a strong relationship between massive filaments and high-mass star formation, through (i) filamentary fragmentation in very early evolutionary phases to form dense cores, (ii) accretion flows along filaments that are important for the growth of dense cores and protostars, and (iii) enhancement of nonthermal motion in the filaments by the feedback or accretion during star formation.
Penetration of Cosmic Rays into Dense Molecular Clouds: Role of Diffuse Envelopes∗
Authors: Ivlev A. V. , Dogiel V. A. , Chernyshov D. O. , Caselli P. , Ko C.-M. , Cheng K. S.
Published: March 2018

A flux of cosmic rays (CRs) propagating through a diffuse ionized gas can excite MHD waves, thus generating magnetic disturbances. We propose a generic model of CR penetration into molecular clouds through their diffuse envelopes, and identify the leading physical processes controlling their transport on the way from a highly ionized interstellar medium to the dense interior of the cloud. The model allows us to describe a transition between a free streaming of CRs and their diffusive propagation, determined by the scattering on the self-generated disturbances. A self-consistent set of equations, governing the diffusive transport regime in an envelope and the MHD turbulence generated by the modulated CR flux, is characterized by two dimensionless numbers. We demonstrate a remarkable mutual complementarity of different mechanisms leading to the onset of the diffusive regime, which results in a universal energy spectrum of the modulated CRs. In conclusion, we briefly discuss implications of our results for several fundamental astrophysical problems, such as the spatial distribution of CRs in the Galaxy as well as the ionization, heating, and chemistry in dense molecular clouds.
Species rediscovery or lucky endemic? Looking for the supposed missing species Leistus punctatissimus through a biogeographer’s eye (Coleoptera, Carabidae)
Authors: Pizzolotto Roberto , Brandmayr Pietro
Published: March 2018

Is it correct to look for a supposedly missing species by focusing research at the type locality? A species can be declared extinct because for an unusual amount of time it has not been seen again; however, in the frame of the climate change it is likely that a supposedly missing species is a lucky survivor not seen because it was not searched for in the correct environment. We used the strictly endemic Leistuspunctatissimus Breit, 1914 (Coleoptera, Carabidae) as the case study for testing the latter hypothesis vs. the type locality approach. On the basis of past unsuccessful searches in the Dolomites (a mountain range in the eastern Alps, Italy) driven by the type locality approach, a study area was selected where climate change may have exerted environmental constraints on endemic species. Five pitfall traps were used in each of seven sample sites, at an average altitude of 2600 m a.s.l., within a high altitude alpine plateau covered by scarce patchy vegetation. Leistuspunctatissimus was rediscovered, far from its type locality, after one hundred years since its first collection. It was part of a group of species well adapted to the extreme ecological factors of the alpine environments above the vegetation line. Following a biogeographical approach (i.e., the biogeographer’s eye rather than the collector’s eye) it was possible to find an endemic species of the alpine ecological landscape in places from where it probably had never disappeared. The supposed refugial area was a nunatak during the last glacial period, where Leistuspunctatissimus found suitable habitat conditions, and from where it alternated between downward and uphill changes in its distribution range after the last glacial period, under the effect of climate change. From such a perspective, it can be concluded that the type locality may be the wrong place to look for a supposedly extinct species.
La vie affective et sexuelle, et le désir de parentalité chez des personnes ayant un handicap psychique
Authors: Vanel Joëlle
Published: March 2018

La vie affective et sexuelle est une dimension de toute personne, quel que soit son âge ou son état. C’est dire qu’il ne faut plus considérer les situations de handicap essentiellement comme des obstacles, des empêchements ou des contrindications. Quant au désir de parentalité, l’auteur nous montre que l’époque actuelle tend à privilégier les adaptations aux situations personnelles, bien souvent éloignées des représentations traditionnelles et qui pourront permettre, avec un accompagnement approprié, un accès facilité à la parentalité.
Vie intime, affective, sexuelle et situations de handicap. Mobilisons-nous !
Authors: Ribes Pascale , Bourden Aude
Published: March 2018

La question de la vie intime, affective et sexuelle est depuis longtemps au cœur des préoccupations de l’APF. Est-ce un droit ou une liberté ? L’APF appelle à dépasser ce débat pour lever enfin les freins à son accès effectif : isolement, inaccessibilité, représentations sociales, législation. Pour cela l’APF s’engage politiquement au niveau national et de manière opérationnelle sur les territoires. Car si le sujet est aujourd’hui plus connu et reconnu, plus que jamais il nous faut militer avec force et détermination pour faire entendre notre voix.
La question de l’assistance sexuelle
Authors: Tabath Julia
Published: March 2018

L’association CH(S)OSE regroupe des acteurs majeurs du monde associatif de la santé et du handicap ainsi que des personnes concernées. Elle a pour objet d’alimenter la réflexion sur la vie intime, affective et sexuelle des personnes en situation de handicap, proposer des actions concrètes en ce sens et se positionne pour la mise en place de l’assistance sexuelle qui associe un cadre éthique de pratiques à des compétences validées et reconnues. CH(S)OSE revendique que la mise en relation entre la personne en situation de handicap et l’assistant.e sexuel.le se fasse au sein d’un service organisé et avec des personnels formés pour garantir une déontologie de cet accompagnement.
La vie affective des locataires de Diagonales
Authors: Piquet Chantal , Letur Liliane , Atine Mylène , Denuit Sylvie , Gauvain Isabelle , Quintin Anne
Published: March 2018

L’association de secteur Diagonales (Quintin, 2016), dans l’Essonne, compte aujourd'hui vingt-cinq logements associatifs et trente-trois patients-locataires. Nous nous sommes demandés, dans une perspective diachronique, dans quelle mesure les locataires de l’association, les Diago comme ils se nomment eux-mêmes, avaient pu développer au même titre que tout un chacun, une vie affective, et partant, dans quelle mesure cette vie affective modifie – ou alors aide, soutient, rend complexe – la prise en charge par le secteur psychiatrique des locataires dans leur appartement. Au détour des histoires que nous livre le personnel du secteur psychiatrique, qui travaille ou non pour l’association Diagonales, nous comprenons que la prise en charge des personnes dans les logements – et partant la considération de leur vie affective – a été une réflexion permanente née des expériences rencontrées et de l’environnement culturel et politique de l’époque de la création de l’association.
Entre passage à l’acte et agression sexuelle : Quels repères ?
Authors: Durand Bernard , Monod Guillaume
Published: March 2018

Il n’est pas possible d’aborder la question de la vie affective et sexuelle des personnes en situation de handicap sans évoquer le cas particulier des conduites déviantes en institution, pouvant avoir une dimension délictuelle, voire criminologique. Pendant des décennies, le silence a prévalu dans les différentes institutions, que ce soit l’hôpital censé soigner des personnes affectées de troubles psychiques ou l’internat médico-éducatif accueillant des personnes dites handicapées mentales. C’est la logique de l’institution « totale », au sens d’Erving Goffman 1 , qui gère le quotidien des personnes qu’elle héberge en s’octroyant notamment un droit de regard sur l’ensemble de leur vie personnelle, y compris leur intimité et leur pudeur. Dans le même temps, cette institution totale ferme les yeux sur la réalité des manifestations pulsionnelles en ne faisant guère de différence entre les pratiques masturbatoires, les rapports hétérosexuels ou homosexuels.
Tips Under the Skin: A Simple Modification of Extension Block Pinning for Mallet Fractures
Authors: Shin Seung-Han , Lee Yong-Suk , Kang Jin-Woo , Kang Wonwoo , Chung Yang-Guk
Published: March 2018

Pins exposed out of the skin after surgery for mallet fractures keep patients from washing their hands. The authors buried the tips of all pins under the skin while performing extension block pinning for 14 patients with mallet fractures. The patients were allowed to wash their hands 4 to 5 days postoperatively, without any dressing or splinting. The pins were removed at a mean of 8 weeks postoperatively. Solid union was achieved in all 14 fractures. No pull-out or subsidence of the pin was observed. No patient developed infection or other pin-related complications. Mean extension lag at final follow-up was 4°. [
Orthopedics.
2018; 41(2):e299–e302.]
Insurance Status Affects In-Hospital Complication Rates After Total Knee Arthroplasty
Authors: Veltre David R. , Yi Paul H. , Sing David C. , Curry Emily J. , Endo Atsushi , Smith Eric L. , Li Xinning
Published: March 2018

Insurance status has been shown to be a predictor of patient morbidity and mortality. The purpose of this study was to evaluate the effect of patient insurance status on the in-hospital complication rates following total knee arthroplasty. Data were obtained from the Nationwide Inpatient Sample (2004 through 2011). Patient demographics and comorbidities were analyzed and stratified by insurance type. Analysis was performed with a matched cohort comparing complication rates between patients with Medicare vs private insurance using the coarsened exact matching algorithm and multivariable logistic regression. A total of 1,352,505 patients (Medicare, 57.8%; private insurance, 35.6%; Medicaid/uninsured, 3.1%; other, 3.3%; unknown, 0.2%) fulfilled the inclusion criteria. The matched cohort analysis comparing Medicare with privately insured patients showed significantly higher risk of mortality (relative risk [RR], 1.34;
P
<.001), wound dehiscence (RR, 1.32;
P
<.001), central nervous system complications (RR, 1.16;
P
=.030), and gastrointestinal complications (RR, 1.13;
P
<.001) in Medicare patients, whereas privately insured patients had a higher risk of cardiac complications (RR, 0.93;
P
=.003). Independent of insurance status, older patients and patients with an increased comorbidity index were also associated with a higher complication rate and mortality following total knee arthroplasty. These data suggest that insurance status may be considered as an independent risk factor for increased complications when stratifying patients preoperatively for total knee replacement. Further research is needed to investigate the disparities in these findings to optimize patient outcomes following total knee arthroplasty. [
Orthopedics.
2018; 41(3):e340–e347.]
English at Your Service
Authors: Krauthamer Helene , Petti Matthew
Published: March 2018

This chapter discusses civic engagement and service-learning in higher education at an urban, land-grant, Historically Black College/University, with a particular focus on the challenges and benefits of service-learning for commuter students. After a discussion of service learning and how it exemplifies the Kolb learning model and effective educational practice, the chapter presents illustrations of civic engagement and extracurricular community-based learning in an English BA program through its two student organizations – The Literary Club and Sigma Tau Delta-Alpha Epsilon Rho. The chapter also provides an example of how service-learning has been implemented in a General Education program and specifically in a writing course. The chapter highlights the partnerships with community organizations that have developed, presents reflective testimonials about the impact of these experiences, provides recommendations for strengthening community-based learning, and concludes that service-learning/community-based learning results in a sense of community for all participants.
Empowering DC's Future Through Information Access
Authors: Anglim Christopher T. , Rusk Faith
Published: March 2018

This chapter describes the various ways that Learning Resources Division at the University of the District of Columbia (LRD) provides various services to the community it operates (i.e., Washington, DC). UDC is the only public university in the District of Columbia. Serving the greater community, therefore, has been a major part of the university mission and a central part of LRD's service mission. Specifically, the chapter considers the service LRD provides to community users through reference, RAIL, information literacy, collection development, the jazz archives, the foundation center, and the university archives.
Fourth Generation Warfare and the Challenges in Military-News Media Relations in India
Authors: Ramani Ramakrishnan
Published: March 2018

Can there be a symbiotic relationship between the armed forces and the private conventional news media in a country with a democratic setup? What are the issues that come between these two entities especially in a complex scenario such as Fourth Generation Warfare? The objective of this chapter is to study these challenges in the relationship between the two institutions in the setting of fourth generation warfare in India. It presents areas of divergence that have been critical in the efficient symbiotic functioning of these two institutions.
The Age of the Internet
Authors: Sethi Aakriti
Published: March 2018

The bittersweet characteristics of internet and social media have caught the imagination of the era we live in. No orb of this society is untouched by the marvels of information and communication technologies (ICT). The evolution of internet from ARPANET to social media sites like Facebook, Twitter, Instagram, or apps like Watsapp has changed the modern world from its core, impacting every nook of every society. These tools and services have made individuals way more involved in political, social, cultural, and economic happenings around the globe, making them feel authorized to send their message/opinion beyond their computer/phone screen. Amidst this backdrop, state and traditional diplomacy has seen remarkable technological changes. The birth of digital diplomacy has opened a plethora of opportunities for the people as well as the state. Postmodern understanding of a state's power beyond the realm of its military capabilities (hard power) and through the lens of soft power has led to many countries trying to win “hearts and minds” across the globe. But, the interaction of state and newer technologies in the midst of labyrinth unconventional threats has changed the traditional rules of the game.
A General Medical Diagnosis System Formed by Artificial Neural Networks and Swarm Intelligence Techniques
Authors: Vasant Pandian
Published: March 2018

One of the most popular applications of artificial intelligence within the medical field is developing medical diagnosis systems. Because artificial-intelligence-based techniques are able to use pre-data and instant data flow for making predictions, it is an easy task to design intelligent systems that can give advice to people or perform diagnosis-based decision making. So, it has been an important research interest to design and develop intelligent systems, which are able to make diagnoses for medical purposes. In this sense, the objective of this chapter is to introduce a general medical diagnosis system that can be used for detecting diseases. In detail, the system employs artificial neural networks and swarm-intelligence-based techniques to form a general framework of intelligent diagnosis. The chapter briefly focuses on the infrastructure of the system and discusses its diagnosis potential.
Robust 3D Visual Localization Based on RTABmaps
Authors: Florido Alberto Martín , Montero Francisco Rivas , Plaza Jose María Cañas
Published: March 2018

Visual localization is a key capability in robotics and in augmented reality applications. It estimates the 3D position of a camera on real time just analyzing the image stream. This chapter presents a robust map-based 3D visual localization system. It relies on maps of the scenarios built with the known tool RTABmap. It consists of three steps on continuous loop: feature points computation on the input frame, matching with feature points on the map keyframes (using kNN and outlier rejection), and 3D final estimation using PnP geometry and optimization. The system has been experimentally validated in several scenarios. In addition, an empirical study of the effect of three matching outlier rejection mechanisms (radio test, fundamental matrix, and homography matrix) on the quality of estimated 3D localization has been performed. The outlier rejection mechanisms, combined themselves or alone, reduce the number of matched feature points but increase their quality, and so, the accuracy of the 3D estimation. The combination of ratio test and homography matrix provides the best results.
A Secured Contactless Fingerprint Verification Method Using a Minutiae Matching Technique
Authors: Djara Tahirou , Assogba Marc Kokou , Vianou Antoine
Published: March 2018

Most matching or verification phases of fingerprint systems use minutiae types and orientation angle to find matched minutiae pairs from the input and template fingerprints. Unfortunately, due to some non-linear distortions, like excessive pressure and fingers twisting during enrollment, this process can cause the minutiae features to be distorted from the original. The authors are interested in a fingerprint matching method using contactless images for fingerprint verification. After features extraction, they compute Euclidean distances between template minutiae (bifurcation and ending points) and input image minutiae. They compute then after bifurcation ridges orientation angles and ending point orientations. In the decision stage, they analyze the similarity between templates. The proposed algorithm has been tested on a set of 420 fingerprint images. The verification accuracy is found to be acceptable and the experimental results are promising. Future work will enhance the proposed verification method by a new template protection technique.
Hydrogen Sorption Kinetics in MgH2 and TiH2 Thin Films
Authors: Hadjixenophontos Efi , Michalek Lukas , Weigel Andreas , Schmitz Guido
Published: March 2018

The diffusion mechanism of H in metals and metal hydrides is studied particularly at high H2 pressures. Thin films of Mg and Ti offer a convenient tool to quantify the atomic transport. We show how different parameters of hydrogenation affect the kinetics. At 200°C, the Pd-Mg interface is predominant and a linear regime of hydrogenation is observed, whereas at 300°C a parabolic regime is detected. In Mg, the hydride forms from the surface to the substrate whereas in Ti growth of TiH2 starts from the substrate. A linear kinetics is seen during hydrogenation of Ti films, which is due to the oxide layer on top, measured to be about 10nm thick. In the studied high pressure regime, the hydrogenation is not pressure dependent any more. Quantitative calculation of the growth rate and the diffusion coefficient of H in the hydrides is presented.
Oxidation Kinetics of Nitrogen Doped TiO2-δ Thin Films: Analysis on the Basis of Oxygen Activity Dependence of the Chemical Diffusion Coefficient
Authors: Sinder Misha , Shi Jian Min , Becker Klaus Dieter
Published: March 2018

The model explaining the occurrence of the electron concentration step front during oxidation of nitrogen-doped TiO2-δ thin films is presented. This model is based on ambipolar chemical diffusion coefficient analysis, for which immobile and uniformly distributed nitrogen component is assumed. The diffusion species and oxygen activity (pressure) profiles are obtained by numerical and approximate analytical simulation of the chemical diffusion. The profiles indicate the presence of two separate singularities: the electron concentration step front, and the electron-hole recombination reaction front. The electron concentration step front relates to the singularity of the ambipolar diffusion of three types of charged species with essentially different diffusion coefficients.
Diffusion Equations for Early Stages of Solid Solutions Decay Based on the Markovian Theory of Random Walk
Authors: Levin Daniil M. , Kolmakov Yury N.
Published: March 2018

Examination was made of the early stages of binodal or spinodal solid solutions decay connected with the growth of local zones of concentration fluctuations. The theory of Markovian process of random walk of the individual atoms describes how particle transport with short diffusion paths causes the growth of these zones. The resulting equation predicts the growth and transformation of initial zones of concentration fluctuations into growing clusters with surface boundary or formation of the quasiperiodic concentration distribution inherent in spinodal decomposition.
Effect of SNCR on the Properties of Fly Ash in Terms of its Applicability to Concrete
Authors: Hela Rudolf , Ťažký Martin
Published: March 2018

At the beginning of 2016, the legislation for regulating and reducing the emission of exhaust gases with regard to reducing nitrogen oxides came into force. The articles published to date point to the possibility of increased ammonium salt content in fly ash that has undergone a selective non-catalytic reduction process. This paper addresses other possible negative impacts of the reduction process for nitrogen oxide on the physico-mechanical properties of high-temperature fly ash, especially the morphology of its grains and its impact on the rheology of the composite and the impact on the efficiency index.
Shear Resistance of Concrete Beams with FRP Grating as a Shear Reinforcement
Authors: Lyčka Lukáš , Stepanek Petr
Published: March 2018

This paper presents an experimental study on the shear behavior of concrete beams with fiber-reinforced (FRP) composite grating as shear reinforcement. Corrosion resistance and non-magnetic properties of FRP reinforcement allows its use in places where application of regular steel reinforcement would face difficulties. The use of FRP composites can increase the life span of constructions and reduce its maintenance costs. Shear stirrups are more susceptible to harsh conditions, due to their placement at the outer face of the reinforcement, and the use of FRP materials can lead to lower concrete cover thickness and therefore to a more effective design of an element.
FRP reinforcements are highly anisotropic material with low strength in the direction perpendicular to the fibers. This causes the strength of a FRP stirrup to be limited by its strength in the bends (corners) of a stirrup. The tensile strength in the corner of the bent stirrup is around 40 to 60% of the strength of the straight bar. FRP grating doesn’t contain a bent section limiting its strength, but its behavior as a shear reinforcement is unknown.
The paper contains the results of own experimental research on concrete beams with shear reinforcement made of FRP gratings done at the Faculty of Civil Engineering at the Brno University of Technology. Test specimen consisted of nine beams with different shear reinforcement ratios. Presented experimental data are then compared with the results of tests on beams with regular shear FRP stirrups found in literature.
Report on Load Resistant Capacity when Promoting Curing PC Beam Specimens Affected by Alkali Silica Reaction
Authors: Murasaka Munenobu , Suzuki Motoyuki
Published: March 2018

In this paper, ｍade a PC beam specimen using ASR reactivity aggregate made in Chinese Zhejiang Ministry and made them do an accelerated curing and the influence by which swell of ASR reactivity aggregate gives it to a PC beam specimen was evaluate. Moreover the PC beam specimen which degraded by swell was classified every degradation grade, a loading test was put into effect and the load carrying capacity was inspected. As a result, I got the following conclusion. ①The thing which classifies the degradation grade into 3 stages (incubation period, acceleration period and degradation period) from the accelerated curing results of the test piece performed in advance. In the incubation period, it was confirmed that the compressive strength and the modulus of static elastic tend to increase more than before accelerated curing. ②Expansion of PC beam specimen was inflated from the upper edge part with less influence of prestress, Moreover as the expansion stabilized, the tendency of the lower edge portion which is highly affected by the prestress to expansion could be confirmed from the strain behavior by monitoring.In addition, with expansion of the lower edge part the prestress amount of the PC steel material placed inside the PC beam specimen (The lower edge position) is increasing and as the prestress amount stabilizes the tendency of expansion of the lower edge part is stabilized can also be confirmed. ③When accelerated curing was further promoted, the expansion of the upper edge and lower edge turned to a decreasing trend, and it was confirmed that stabilize tendency at about 25 to 35% of the maximum expansion. ④The P-δ curve up to fracture was measured for PC beam specimen before accelerated curing and ② to ③. As a result, it was not possible to confirm a large difference at the P-δ curve before accelerated curing and ②, but a significant decrease in load bearing capacity was confirmed at ④.
Repeatability and Reproductibility of Results of Fresh Concrete Testing
Authors: Misák Petr , Vymazal Tomáš , Kocáb Dalibor , Kucharczyková Barbara
Published: March 2018

The aim of this paper is to summarize the results of 11 experiments which focused on assessing the precision of results of fresh concrete testing. The observed characteristics are slump test, flow table test, density and air content. More than twenty participants (testing laboratories) took part in these experiments. The test results were evaluated with statistical methods used for evaluations of interlaboratory comparisons. The article deals especially with the values of repeatability and reproducibility, which provide further understanding of the interval within which it is possible to expect with the given probability the test results measured in one or more laboratories.
Numerical Analysis of Prestressed UHPC Lightened Member
Authors: Kopálová Michaela , Pribramsky Vladimír
Published: March 2018

UHPC (ultra-high-performance concrete) is one of the essential elements in the development and research of new modern concrete structures. It is a material showing all the positive qualities in terms of the design efficiency and construction process. In this paper, we analyze the behavior of prestressed UHPC I-beam with lightened web that is loaded by four-point bending test. Two variants of I-beam were used for the analysis. The first variant is beam with a continuous thin web and the second variant is beam with lightened web, which is analogous to castellated steel I-profiles, commonly used types of steel beams with larger span. Although these are relatively small specimens, light beam analysis can be extrapolated for large span structures, especially bridges. In case of structures of larger magnitude with precast members of UHPC, a certain amount of discontinuous action cannot be avoided, which is the case of using a lightened beam with openings across the entire height of the web. Application of prestressed tendons ensures sufficient resistance for bending action; members are designed so failure occurs by shear response.
Study of Corrosion Damage of Glass Fibers in Textile Fiberglass Reinforcement under Expositions Simulating Concrete Environment
Authors: Bittner Tomáš , Pokorný Petr , Bouška Petr , Nenadálová Šárka
Published: March 2018

The main point of this paper is to assess the level of corrosion damage of the composite textile fiberglass reinforcement in environments that simulate the concrete pore solution by the techniques of FT-IR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy) as well as EDS (scanning electron microscopy). Effect of corrosion on the tensile strength segmented textile glass fiber was tested and also it was investigated specific type of protective organic coating on glass fiber. The results express the evidence of local corrosion damage on the examined samples just at pH 13.5, and on the contrary high stability in the environment simulating carbonated concrete and concrete contaminated by chloride anions. The thesis also points on the unevenness of the excluded protective organic coating with localized porosity which relates to the above mentioned corrosion damage.
Systems and Regulations for Design and Application of Water-Tight Concrete Structures
Authors: Hubáček Adam
Published: March 2018

The paper focuses on the problems of concrete for water-tight concrete structure and with systém and regulations for design and application of these structures. The theme is currently quite topical in the Czech Republic and abroad. The accent is put particularly on the requirements and properties of fresh concrete or self-compacting concrete for manufacture of specific concrete structures. Properties of hardened concrete will be also observed; in particular compressive strength, resistance to pressure water, durability and other parameters.
Assessment of the Concrete Compressive Strength in Existing Structures Based on Core Test Results
Authors: Tur Viktar V. , Derechennik Stanislav S.
Published: March 2018

Evaluation of the concrete compressive strength in existing structures is an important problem, which is associated with structural reliability estimation as well as a quality control procedure. In accordance with a new concept of EN 13791, reported by T.A.Harrison, one of the main targets of the standard is to determine not a class, but in-situ characteristic concrete compressive strength. Hereby proposed criterion for the estimation of the in-situ characteristic concrete compressive strength is based on the non-parametric confidence interval for quantile. This criterion was verified by the both Monte Carlo simulation and test results under the real concrete structures.
Parametrical Study of the Shear Resistance of the Approach Slabs
Authors: Laco Kamil , Borzovič Viktor
Published: March 2018

The transition zone of the road bridges is located right behind the abutment. Function of this structure is to ease the vehicle transition from the bridge on the rigid support to the embankment with much smaller stiffness. The main function of the approach slab is, as a part of the transition zone, helping the backfill to overcome different stiffness of the bridge foundations and embankment. The paper deals with shear resistance of the slabs for different lengths and widths. Parametrical study was performed according to Eurocode loading model 1 (Uniformed distributed load and Tandem system). Each of the analysed slabs was loaded with sets of different TS positions and location of the loading lanes. Envelopes of the shear forces of the approach slabs were analysed for each type of the slab. After that shear resistance of the slab with or without the shear reinforcement was calculated. The slab was divided into areas with same shear reinforcement distribution. The analysis is the part of the engineering tool for the bridge designers. According to length and width of the slab, the engineer can easily choose the shear reinforcement diameter and its distribution. The tool also provides the construction details of the shear reinforcement. There will be also the option for the reinforcement design of the slab, with hints for the structural scheme and calculation method.
Stochastic Optimization of a Reinforced Concrete Elements Using Heuristic Algorithm
Authors: Venclovský Jakub , Stepanek Petr , Laníková Ivana
Published: March 2018

It is possible to see various applications of mathematical optimization in civil engineering (structural design, reconstruction of transportation networks etc.) Initially, deterministic approaches have been introduced to solve these problems. But despite their complexity, these approaches are insufficient to comprehend the probabilistic nature of said problems and thus provide only suboptimal solutions. Hence the effort comes to reconsider these deterministic approaches and deal with uncertainties involved in said problems in less straightforward way. The goal of the paper is to present the algorithm for stochastic optimization of design of steel-reinforced concrete cross-section. This algorithm is based on internal cycle of deterministic optimization using reduced gradient method and external cycle of stochastic optimization using regression analysis. Firstly, the deterministic problem is introduced and described. It is followed by the description of uncertainties, which are involved in the process, and stochastic reformulation of the problem. Then the algorithm itself is introduced and the paper ends with presentation of the results of performed calculations.
Development of Geopolymer Mortar for Field Applications
Authors: Reed Remington G. , Daniels III Jospeh , Hale W. Micah
Published: March 2018

In recent years there has been an increased demand for environmentally conscious and sustainable construction materials. One such material is “geopolymer” or “alkali-activated” binder. Current industry practice uses ordinary portland cement (OPC) in combination with supplementary cementitious materials as binder in concrete and mortar. Cement production is very energy intensive and accounts for approximately 10 percent of the total carbon dioxide emission in the world. In geopolymer materials, OPC is replaced with waste materials such as fly ash or slag cement along with a chemical activator. When supplied with additional chemical constituents, the aluminate and silicate present in fly ash or slag cement arrange into a polymeric structure with similar properties to hydrated cement. Proper application of this material can reduce, or even replace, the use of OPC in concretes and mortars. In addition to the cutback in OPC and the use of waste products, geopolymer materials require less water for curing and are shown to have increased resistance to chemical attack. While this product offers a “green” alternative to OPC, it is a new technological concept. Fly ash variability creates inconsistencies in quality control and chemical content. The chemical activators used to facilitate polymerization are often quite expensive and dangerous to use. Additionally, heat curing can be necessary for a geopolymer material to achieve specified compressive strength. Present limitations warrant extensive research and development to increase practicality of geopolymer materials for field implementation. In order to aid in the design and use of geopolymer materials, it is important that laboratory studies fully address the use of less than ideal materials and conditions in the creation of geopolymer. By using low cost materials and avoiding heat curing, laboratory research on geopolymer mortar can function as a means of developing a material that can be readily adopted into practice.
Bond Behavior of FRP Bars in Concrete
Authors: Januš Ondřej , Girgle Frantisek , Kostiha Vojtech , Stepanek Petr
Published: March 2018

This article deals with the bond of internal composite (FRP) reinforcement with different surface treatments. Bars with additional sand-coating exhibit different behavior due to different transmission of forces in relation to bars with ribbed surface. To compare the bond behavior of these types of reinforcement, an experimental program consisting of several sets of pull-out tests was designed. This test configuration was chosen primarily for simplicity, comparability with previously published results, and especially easy modification for assessment the effect of concrete cover thickness. The paper presents the results confirming the direct influence of the surface treatment and also the position of the reinforcement on the resulting bond behavior.
Experimental Determination of how the Static Modulus of Elasticity is Influenced by the Value of the Upper Loading Stress
Authors: Kocáb Dalibor , Misák Petr , Daněk Petr , Kucharczyková Barbara , Halamová Romana
Published: March 2018

There is a large number of factors that have a strong influence on the elastic modulus of concrete. These are technological influences as well as issues connected with the testing methods for its determination, one of which is the choice of the upper loading stress of cyclic loading during testing the static modulus of elasticity of concrete in compression. The upper loading stress should be equal to 1/3 of the specimen’s compressive strength, however, its choice is often made incorrectly. This paper describes an experiment focused on discovering the impact that deviating from the 1/3 upper loading stress has on the measured value of the static modulus of elasticity.
Dynamic Component Load of the Prefabricated Panels during their Handling
Authors: Janda Miloslav , Zich Miloš
Published: March 2018

Prefabricated panels are handled by various types of crane during the assembly (bridge crane in the production hall and construction crane on site). The panel is loaded with inertial forces during manipulation caused by crane's starting and breaking movement. These forces significantly affect the design of the transport system (anchors, ropes, etc. In literature there are different values of dynamic coefficient for different types of crane. In the experiment, the magnitude of the force in the crane hinge was measured during the handling of various panel types in the production hall and during the construction site installation. The static value of the force size was determined at the moment when the panel freely hanged on crane hinge. The measured values are further compared with the manufacturer’s recommendation for the design of the transport anchors.
Two Options of Self-Curing of High Performance Concrete
Authors: Pytlík David , Bilek Vlastimil
Published: March 2018

Some effects of self-curing on the mechanical properties of High Performance Concrete (HPC) are discussed in this paper. The matrix of HPC is very dense and it is very difficult to deliver the curing water into the cement matrix. Two different materials in different dosages were selected to examine self-curing. Polymer curing agent (PCA) was selected as the first, and 0.2% 0.4% 0.6% and 0.8% of PCA were added by weight of cement. This additive should allow the physicochemical binding of a larger portion of the mixing water and then release it slowly for better hydration without negative effects on the products. Pre-soaked slag of 0/4 mm was tested as another source of water for internal curing. The slag was also dosed in 10%, 15%, 20% and 30% volume of sand with the fraction 0/4 mm. Referential HPC was a high-dose cement that consumes a large amount of water for hydration. The water/cement ratio was 0.2. Metakaolin was added to improve the properties of fresh and hardened HPC.
Tensile Strength Tests for Concrete and Fibre Reinforced Concrete
Authors: Tipka Martin , Vaskova Jitka , Vodicka Jan
Published: March 2018

The paper describes the differences in several test methods, which are used for tensile strength analysis of cementitious composites. It explains tests arrangement, their benefits and disadvantages. The conversion factors between detected strengths were quantified in experiments, depending on the particular composition of the composite.
Pharmacogenomics in Critical Care
Authors: Cheek Dennis , Howington Lynnette
Published: March 2018

Since the successful completion of the Human Genome Project in 2003, extensive genomic research has continued to alter pathophysiology at the molecular level. This research includes investigation of the specific receptors and metabolizing enzymes in drug pharmacodynamics and pharmacokinetics, specifically the cytochrome P450 system located primarily in the liver. In this article, pharmacogenomics and the role of the cytochrome P450 system in metabolism of various drugs are discussed. Specifically, drugs that are used in the critical care setting and are of clinical significance to the bedside critical care nurse are examined.
Extent, origin, and deposit-scale controls of the 1883 Ma Circum-Superior large igneous province, northern Manitoba, Ontario, Quebec, Nunavut and Labrador
Authors: Bleeker W , Kamo S L
Published: March 2018

An update is presented on research in the setting and controls on Ni-Cu-PGE in the ca. 1883 Ma Circum-Superior belt, here with a specific focus on the Raglan belt of northern Quebec. A new stratigraphic interpretation indicates that the critical part of the
stratigraphy is less imbricated by numerous thrusts than previously hypothesised and that the critical Povungnituk to Chukotat Group contact, i.e. the Raglan Horizon, is stratigraphic and not a regional thrust. This contact, along which hot komatiitic lavas flowed out over easily fusible graphitic
mudstone of the Nuvilik Formation, is stitched together in a primary sense by thermo-mechanical erosion channels with some of the largest sulphide ore lenses hosted by the deepest lava channels that eroded down through Nuvilik sediments into footwall gab-bro sills. Precise U-Pb ages on these gabbro
sills, and on slightly younger gabbro sills that intruded above the lower-most komatiite flows and ore lenses, bracket the mineralization to ca. 1882 Ma, an age that is identical to those of the Thompson deposits in Manitoba. The bulk of the sulphide ore formed during peak effusion rates of
komatiitic lava during the onset of the overall magmatic event. This major magmatic event has (coeval) expressions at the scale of the entire Superior craton and its margins, suggesting a geodynamic setting of hot mantle upwelling and continental break-up rather than perfectly synchronized arc
processes.
Controls on the localization and timing of mineralized intrusions in intra-continental rift systems, with a specific focus on the ca. 1.1 Ga Mid-Continent Rift system
Authors: Bleeker W , Liikane D A , Smith J , Hamilton M , Kamo S
L , Cundari R , Easton M , Hollings P
Published: March 2018

A brief report is presented on the early stages of our study of the ca. 1.1 Ga Mid-continent Rift system, which hosts a diverse range of intrusions, many of which are mineralized and are being actively explored. Key questions to be ad-dressed by this study are
the localization of the mineralized intrusions, and whether we can resolve, through addition-al and more precise U-Pb geochronology, clear temporal, spatial, and tectonic patterns that link the various intrusions to the overall evolution of the rift system, and to specific stages of the flood basalt
sequence. An initial compilation is presented of all known intrusions and their associated questions.
Migration Crisis and Christian Response: From Daniel De Groody’s Image of God Theological Prism in Migration Theology to a Migration Practical Theology Ministerial Approach and Operative Ecclesiology
Authors: Magezi Vhumani , Magezi Christopher
Published: March 2018

This article identifies a need to develop an operational theology that responds to migrants in a real and constructive way. It discusses Daniel Groody’s image of God prism in migration theology in order to develop an integrated understanding of the image of God. It argues that Groody’s image of God prism in migration theology is assumed rather than explicit and does not proceed to inform migrant ministry design. To ensure an encompassing understanding of the notion of the image of God, an integrated understanding that integrates the various views is adopted. The adopted integrated understanding of the image of God extends beyond Groody’s image of God prism in migration theology that is systematic theological and theoretical to a development of a migration diagnostic and ministry design framework that employs the various dimensions (views) of the image of God. In doing so, the integrated understanding of the image of God is employed in a practical theological conceptualisation and ministry design to promote and encourage dispositional ethics service, care, acceptance and justice. The first section problematises the challenge of theology and Christian response to migration crisis. The second section discusses Groody’s image of God theological prism in migration theology. The third section discusses the various interpretations of the image of God. The fourth section proposes a diagnostic framework and ministry design that utilises the integrated image of God.
Community harvesting of trees used as dens and for food by the tree hyrax (Dendrohyrax arboreus) in the Pirie forest, South Africa
Authors: Opperman Elizabeth J. , Cherry Michael I. , Makunga Nokwanda P.
Published: March 2018

Forests in South Africa are harvested by local communities for multiple purposes and this affects the animals that inhabit them. The tree hyrax (Dendrohyrax arboreus) has a restricted distribution and utilises various tree species as dens and a source of food. In this article, we determined, through a series of interviews in the communities surrounding the Pirie forest, which plant species are harvested by local people and whether these overlap with those used by the tree hyrax. In addition, we determined the extent to which tree hyraxes are hunted by these communities. Of the trees used by the hyrax as dens in the Pirie forest, Afrocarpus falcatus, Schotia latifolia, Andrachne ovalis, Teclea natalensis and Apodytes dimidiata are important resources for local communities. But as these are harvested at relatively low levels, it is unlikely that current harvesting has a large impact on the tree hyrax. Opportunistic hunting occurs, but the hyrax is not targeted by hunters. Very limited commercial harvesting of A. falcatus has been taking place in the Pirie forest since 1975, but its impact on the hyrax population, although undetermined, is also unlikely to be high. We recommend that the Pirie forest tree hyrax population should be monitored by forest management in order to ascertain the impact of both commercial and community harvesting over the past quarter-century.Conservation implications: Tree hyrax populations in the Pirie forest should be actively monitored by management on an annual basis.