bluuebunny/crossref_metadata_2025 huggingface dataset:
A Strain-Softening Constitutive Model of Heterogeneous Rock Mass Considering Statistical Damage and Its Application in Numerical Modeling of Deep Roadways
Authors: Li Guang , Ma Fengshan , Liu Gang , Zhao Haijun , Guo Jie
Published: April 2019

During the construction of underground caverns, the stability of deep underground cavern excavation, which affects the safety and sustainable development of such projects, is a hot issue. First, based on the mechanical properties of surrounding rock in deep tunnels, the strain-softening behavior, damage, and heterogeneity of rock masses are analyzed. Then, a strain-softening model of heterogeneous jointed rock mass that considers statistical damage (SSD) is developed and implemented through FLAC3D simulation software. Finally, the SSD is applied to a deep roadway in the Jinchuan mining area, and a comparative analysis of the computation results of the Mohr–Coulomb (MC) model and the strain-softening (SS) model are carried out. The numerical results are compared with the field-monitoring results, which show that the SSD model simulated the behavior of the surrounding rocks well. The results show that the deformations of the roof and floor are larger, which may serve as a reference for the support pattern of deep roadways.
Spatio–Temporal Variations in Impervious Surface Patterns during Urban Expansion in a Coastal City: Xiamen, China
Authors: Man Wang , Nie Qin , Hua Lizhong , Wu Xuewen , Li Hui
Published: April 2019

Impervious surfaces (IS) coverage is a quantifiable environmental indicator for understanding urban sprawl and its potential impacts on sustainability of urban ecological environments. Numerous studies have previously demonstrated global and regional IS variation, but little attention has been paid to the different internal and external patterns of IS development as urbanization progresses. This study estimates IS coverage in a subtropical coastal area of Xiamen, southeastern China, from Landsat TM/OLI images obtained in 1994, 2000, 2004, 2010, and 2015, and quantifies its spatio–temporal variations using IS change trajectories and radar graphs. During the study period, IS gradually expanded along the shoreline in a pattern resembling the shape of the bay. The land surfaces are classified into four zones: IS1 and IS2, dominated by cultivated land and forest; IS3, complex land use/coverage; and IS4, built-up areas. The progression and transformations of these zones highlight the main trends in IS changes in the study area. The trajectories of the zones form a layered structure in which the urban centers of each district progressively gain IS4, and transformations into IS3 and IS2 extend successively beyond the centers. The orientation of IS expansion in each of the six districts of Xiamen is revealed by radar graphs. The areas containing intermediate and high percentages IS each expanded in generally consistent directions throughout the study period, except in Tong’an district, which showed a change in the direction of expansion of its area of intermediate and high IS.
Lightweight Architecture for Real-Time Hand Pose Estimation with Deep Supervision
Authors: Wu Yufei , Ruan Xiaofei , Zhang Yu , Zhou Huang , Du Shengyu , Wu Gang
Published: April 2019

The high demand for computational resources severely hinders the deployment of deep learning applications in resource-limited devices. In this work, we investigate the under-studied but practically important network efficiency problem and present a new, lightweight architecture for hand pose estimation. Our architecture is essentially a deeply-supervised pruned network in which less important layers and branches are removed to achieve a higher real-time inference target on resource-constrained devices without much accuracy compromise. We further make deployment optimization to facilitate the parallel execution capability of central processing units (CPUs). We conduct experiments on NYU and ICVL datasets and develop a demo1 using the RealSense camera. Experimental results show our lightweight network achieves an average running time of 32 ms (31.3 FPS, the original is 22.7 FPS) before deployment optimization. Meanwhile, the model is only about half parameters size of the original one with 11.9 mm mean joint error. After the further optimization with OpenVINO, the optimized model can run at 56 FPS on CPUs in contrast to 44 FPS running on a graphics processing unit (GPU) (Tensorflow) and it can achieve the real-time goal.
Governance for Sustainability of Estuarine Areas—Assessing Alternative Models Using the Case of Ria de Aveiro, Portugal
Authors: Fidélis Teresa , Teles Filipe , Roebeling Peter , Riazi Fayaz
Published: April 2019

Estuaries are one of the most productive and complex types of ecosystems supporting a wide range of economic activities. Departing from a set of governance problems and emergent goals, such as sustainability or climate change adaptation faced by an estuarine case study area, Ria de Aveiro, in Portugal, this article assesses the adequacy of alternative governance models under the existing water resources legal framework and traditional political culture. It shows that apart from the centrally-based compliance model, all other alternatives require high degrees of institutional reforms. Moreover, although the model based on a dedicated new agency, long preferred by many users of Ria de Aveiro, is the most understandable and focused, it does not assure the pursuance of adaptability or collaboration, which are considered essential for estuary governance. As it relies on collective action and multi-level and multi-agent contexts, estuarine governance may require a new institutional design. Where one begins a process of institutional change, however, is not a simple issue to address and demands a deeper analysis, particularly on the types of required institutional changes, as well as on their impacts on policy and decision-making outcomes over estuarine environments and associated socio-ecological networks.
Evaluating Curb Inlet Efficiency for Urban Drainage and Road Bioretention Facilities
Authors: Li Xiaoning , Fang Xing , Chen Gang , Gong Yongwei , Wang Jianlong , Li Junqi
Published: April 2019

An updated two-dimensional flow simulation program, FullSWOF-ZG, which fully (Full) solves shallow water (SW) equations for overland flow (OF) and includes submodules modeling infiltration by zones (Z) and flow interception by grate-inlet (G), was tested with 20 locally depressed curb inlets to validate the inlet efficiency (Eci), and with 80 undepressed curb inlets to validate the inlet lengths (LT) for 100% interception. Previous curb inlet equations were based on certain theoretical approximations and limited experimental data. In this study, 1000 road-curb inlet modeling cases from the combinations of 10 longitudinal slopes (S0, 0.1–1%), 10 cross slopes (Sx, 1.5–6%), and 10 upstream inflows (Qin, 6–24 L/s) were established and modeled to determine LT. The second 1000 modeling cases with the same 10 S0 and 10 Sx and 10 curb inlet lengths (Lci, 0.15–1.5 m) were established to determine Eci. The LT and Eci regression equations were developed as a function of input parameters (S0, Sx, and Qin) and Lci/LT with the multiple linear regression method, respectively. Newly developed regression equations were applied to 10,000 inlet design cases (10 S0, 10 Sx, 10 Qin, and 10 Lci combinations) and comprehensively compared with three equations in previous studies. The 100% intercepted gutter flow (Qg100) equations were derived, and over-prediction of Qg100 from previous methods was strongly correlated to smaller S0. Newly developed equations gave more accurate estimations of LT and Eci over a wide range of input parameters. These equations can be applied to designing urban drainage and road bioretention facilities, since they were developed using a large number of simulation runs with diverse input parameters, but previous methods often overpredict the gutter flow of total interception when the longitudinal slope S0 is small.
Association of GP wellbeing and burnout with patient safety in UK primary care: a cross-sectional survey
Authors: Hall Louise H , Johnson Judith , Watt Ian , O’Connor Daryl B
Published: April 2019

Background

GPs have particularly high levels of burnout and poor wellbeing. Although both are associated with poorer safety outcomes within secondary care, there have been no quantitative studies investigating this within primary care. Furthermore, little is known about how occupational demands, burnout and wellbeing, and patient safety are all associated.

Aim

To investigate whether occupational variables (demands and support) are associated with patient safety outcomes in general practice through their influence on GP burnout and wellbeing.

Design and setting

Cross-sectional survey in the UK between March 2016 and August 2017.

Method

A total of 232 practising GPs completed an online or paper survey measuring burnout, wellbeing, occupational demands and support, and patient safety.

Results

In all, 93.8% of GPs were classed as likely to be suffering from a minor psychiatric disorder, 94.7% as suffering from mild (22.0%) or severe (72.7%) exhaustion, and 86.8% as having mild (37.9%) or severe (48.9%) disengagement. Structural equation modelling (SEM) analyses showed that spending a higher number of hours on administrative tasks and on call, and feeling less supported in their practice, was associated with lower wellbeing, which in turn was associated with a higher likelihood of having reported a near miss in the previous 3 months. A higher number of hours spent on administrative tasks, a higher number of patients seen per day, and feeling less supported were associated with higher burnout levels, which in turn was associated with worse perceptions of safety.

Conclusion

To improve patient safety within general practice changes could be made at both practice and individual levels to promote a healthier work environment for staff and patients.
The Local Perspective on the Hubble Tension: Local Structure Does Not Impact Measurement of the Hubble Constant
Authors: Kenworthy W. D’Arcy , Scolnic Dan , Riess Adam
Published: April 2019

We use the largest sample to date of spectroscopic supernova (SN) Ia distances and redshifts to look for evidence in the Hubble diagram of large-scale outflows caused by local voids suggested to exist at z < 0.15. Our sample combines data from the Pantheon sample with the Foundation survey, and the most recent release of light curves from the Carnegie Supernova Project, to create a sample of 1295 SNe over a redshift range of 0.01 < z < 2.26. We make use of an inhomogeneous and isotropic Lemaitre–Tolman–Bondi metric to model a void in the SN Ia distance–redshift relation. We conclude that the SN luminosity distance–redshift relation is inconsistent at the 4–5σ confidence level with large local underdensities (

, where the density contrast δ = Δρ/ρ) proposed in some galaxy count studies, and find no evidence of a change in the Hubble constant corresponding to a void with a sharp edge in the redshift range 0.023 < z < 0.15. With an empirical precision of

, we conclude that the distance ladder measurement is not affected by local density contrasts, in agreement with a cosmic variance of

, predicted from simulations of large-scale structure. Given that uncertainty in the distance ladder value is

, this does not affect the Hubble tension. We derive a 5σ constraint on local density contrasts on scales larger than

of

. The presence of local structure does not appear to impede the possibility of measuring the Hubble constant to 1% precision.
NLTE Analysis of Copper Abundances in the Galactic Bulge Stars
Authors: Xu X. D. , Shi J. R. , Yan H. L.
Published: April 2019

Based on the medium-high resolution (R ∼ 20,000), modest signal-to-noise ratio (S/N ≳ 70) FLAMES-GIRAFFE spectra, we investigated the copper abundances of 129 red giant branch stars in the Galactic bulge with [Fe/H] from −1.14 to 0.46 dex. The copper abundances are derived from both local thermodynamic equilibrium (LTE) and nonlocal thermodynamic equilibrium (NLTE) with the spectral synthesis method. We find that the NLTE effects for Cu i lines show a clear dependence on metallicity, and they gradually increase with decreasing [Fe/H] for our sample stars. Our results indicate that the NLTE effects of copper are important not only for metal-poor stars but also for supersolar metal-rich ones and the LTE results underestimate the Cu abundances. We note that the [Cu/Fe] trend of the bulge stars is similar to that of the Galactic disk stars spanning the metallicity range of −1.14 < [Fe/H] < 0.0 dex, and the [Cu/Fe] ratios increase with increasing metallicity when [Fe/H] is from ∼−1.2 to ∼−0.5 dex, favoring a secondary (metallicity-dependent) production of Cu.
The Wave Nature of Continuous Gravitational Waves from Microlensing
Authors: Liao Kai , Biesiada Marek , Fan Xi-Long
Published: April 2019

Gravitational wave predicted by general relativity is the transverse wave of spatial strain. Several gravitational waveform signals from binary black holes and from a binary neutron star system accompanied by electromagnetic counterparts have been recorded by the advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and the advanced Virgo. In analogy to light, the spatial fringes of diffraction and interference should also exist as the important features of gravitational waves (GWs). We propose that observational detection of such fringes could be achieved through gravitational lensing of continuous GWs. The lenses would play the role of the diffraction barriers. Considering peculiar motions of the observer, the lens, and the source, the spatial amplitude variation of diffraction or interference fringes should be detectable as an amplitude modulation of a monochromatic gravitational signal.
Line Profiles of the Calcium I Resonance Line in Cool Metal-polluted White Dwarfs
Authors: Blouin S. , Allard N. F. , Leininger T. , Gadéa F. X. , Dufour P.
Published: April 2019

Metal-polluted white dwarfs (DZ stars) are characterized by a helium-rich atmosphere contaminated by heavy elements traces originating from accreted rocky planetesimals. As a detailed spectroscopic analysis of those objects can reveal the composition of the accreted debris, there is a great interest in developing accurate DZ atmosphere models. However, the coolest DZ white dwarfs are challenging to model due to the fluidlike density of their atmospheres. Under such extreme conditions, spectral absorption lines are heavily broadened by interactions with neutral helium, and it is no longer justified to use the conventional Lorentzian profiles. In this work, we determine the theoretical profiles of the Ca i resonance line (the most prominent spectral line for the coolest DZ white dwarfs) in the dense atmospheres of cool DZ white dwarfs. To do so, we use a unified theory of collisional line profiles and accurate ab initio potential energies and transition dipole moments for the CaHe molecule. We present the resulting profiles for the full range of temperatures and helium densities relevant for the modeling of cool, metal-polluted white dwarfs (from 3000 to 6000 K and from 1021 to 1023 cm−3). We also implement these new profiles in our atmosphere models and show that they lead to improved fits to the Ca i resonance line of the coolest DZ white dwarfs.
Continuous venovenous hemodiafiltration in the treatment of newborns with an inborn metabolic disease: a single center experience
Authors: AKDUMAN HASAN , OKULU EMEL , EMİNOĞLU FATMA TUBA , KENDİRLİ TANIL , TUNÇ GAFFARİ , AZAPAĞASI EBRU , PERK OKTAY , EREDERE ÖMER , ATASAY BEGÜM , ARSAN SAADET
Published: April 2019

Background/aim: Most inborn metabolic diseases are diagnosed during the neonatal period. The accumulation of toxic metabolites may cause acute metabolic crisis with long-term neurological dysfunction and death. Renal replacement therapy (RRT) modalities allow the efficient removal of toxic metabolites. In this study, we reviewed our experience with continuous venovenous hemodiafiltration (CVVHDF) as RRT for newborns with an inborn metabolic disease.
Materials and methods: Patients diagnosed with an inborn metabolic disease who received CVVHDF treatment at our neonatal intensive care unit between January 2014 and December 2017 were included in this study. Their demographic and clinical data were collected, and the efficacy and safety of CVVHDF was evaluated.
Results: Nine continuous RRT (CRRT) sessions as CVVHDF were performed in eight newborns with a diagnosis of urea cycle defect (n= 5), maple syrup urine disease (n= 2), or methylmalonic acidemia (n= 1). The mean age at admission was 10 ± 8.6 days (range: 3–28 days). The mean plasma levels of ammonium were 1120 ± 512.6 mg/dL and 227.5 ± 141.6 mg/dL before and at the end of treatment, respectively. Plasma levels of leucine were 2053.5 ± 1282 µmol/L and 473.5 ± 7.8 µmol/L before and at the end of treatment, respectively. The CVVHDF duration was 32.3 ± 11.1 h (median: 37 h; range: 16–44 h), and the mean length of hospitalization was 14.6 ± 12.9 days. The mean duration of CVVHDF was 32.3 ± 11.1 h (range: 16–44 h). Circuit clotting was the most common observed complication (37.5%) and the survival rate was 50%. Among surviving patients, two developed severe and two developed mild mental and motor retardation.
Conclusion: CVVHDF is a CRRT modality that can be used to treat newborns with an inborn metabolic disease. Early diagnosis, and commencement of specific medical therapy, diet, and extracorporeal support, if needed, are likely to result in improved short- and long-term outcomes.
Key words: Inborn metabolic diseases, renal replacement therapy, continuous venovenous hemodiafiltration, newborn, survival
De la discontinuité à l’alternance. À propos d’un dispositif hospitalier particulier
Authors: Lepage Anouk
Published: April 2019

L’article aborde comment l’écoute analytique a décelé la phobie chez un patient initialement diagnostiqué psychotique. Le traitement de la phobie de ce patient s’est effectué à partir d’un dispositif hospitalier particulier. L’auteure décrit comment l’introduction d’un rythme dans les hospitalisations a permis le passage d’une discontinuité symptomatique à une alternance symboligène servant d’appui à l’émergence d’un phantasme et d’une subjectivité.
De l’ endoctrinologue à la mise en scène, trajet d’une jeune fille souffrant d’anorexie
Authors: Taverna Isabelle
Published: April 2019

Cet article est le témoignage d’un travail analytique avec une jeune patiente souffrant d’anorexie et de la suppléance qu’elle inventera pour soutenir sa subjectivité. Différents aspects constituent un éclairage dans la lecture de cette situation. Le premier est celui de la privation, auquel viennent s’articuler ceux de l’aliénation-séparation. Un autre aspect est le postulat de l’anorexie de cette patiente, comme symptôme- out , concept développé par J.-M. Forget.
Secure Cyber-Physical Systems for Improving Transportation Facilities in Smart Cities and Industry 4.0
Authors: Thayananthan Vijey , Yazdani Javad
Published: April 2019

The main aim of this strategic research proposal is to develop a model of secure transportation system using efficient CPS which not only reduce the unnecessary accident rates but also increase safety system that enhances the livability of smart cities and Industry 4.0. Although the main focus is efficient security solutions, dynamic and intelligent approaches of the future security solutions will be able to detect the evolving threats and cyberattacks during the data or signal transmission between the users and service providers.
Privacy Preservation in Smart Grid Environment
Authors: Lawal Muhammad Aminu , Hassan Syed Raheel
Published: April 2019

Smart grids are conceived to ensure smarter generation, transmission, distribution, and consumption of electricity. It integrates the traditional electricity grid with information and communication technology. This enables a two-way communication among the smart grid entities, which translates to exchange of information about fine-grained user energy consumption between the smart grid entities. However, the flow of user energy consumption data may lead to the violation of user privacy. Inference on such data can expose the daily habits and types of appliances of users. Thus, several privacy preservation schemes have been proposed in the literature to ensure the privacy and security requirements of smart grid users. This chapter provides a review of some privacy preservation schemes. The schemes operational procedure, strengths, and weaknesses are discussed. A taxonomy, comparison table, and comparative analysis are also presented. The comparative analysis gives an insight on open research issues in privacy preservation schemes.
Social and Economic Consequences of Violent Armed Conflicts
Authors: Sudan Falendra Kumar
Published: April 2019

Ongoing violent armed conflict in Jammu and Kashmir has resulted in the displacement of thousands of non-Kashmiri households since early 1998. Displacement increases the pressures on young children to work, possibly at the expense of their schooling, and also leads to under-nourishment and malnutrition, which has caused poor physical growth, inability to learn, and poor work performance. The “care and maintenance” assistance and aid received by displaced families was completely undependable, erratic, and inadequate, and given the opportunity, they would like to move out from the camp as quickly as possible. The displaced children have special vulnerabilities and require additional care and protection from disease, hunger, malnutrition, and abuse. There is urgent need to meet the physical needs of displaced families such as water, sanitation, healthcare, shelter, and psycho-social assistance. Education, including literacy training, primary, secondary, tertiary, vocational, life skills, informal, and other age-specific educational opportunities, is needed for young children.
Library
Authors: Olubodun Oluyemi Joshua , Oye Peter Olorunleke
Published: April 2019

This chapter is a conceptual establishment of the intrinsic potential of the library as a platform and mechanism for conflict prevention, resolution, peace-building, and sustainable wellbeing in society. Relying on evidence-based statistics, the chapter highlighted the rising tide of conflicts around the world, causes, consequences, and solutions. Latching on empirical studies, the chapter established the inherent propensity of the library as an information dissemination agency imbued with constructive skills to deliver desired attitude for peace in societies. The chapter suggested that the library's unique potentials should be strengthened so that it can better provide relevant services to people for a better and peaceful society.
Digitization and Sustainability
Authors: Arnold Marlen Gabriele , Fischer Anne
Published: April 2019

Digitization and sustainability are two mega-trends. There are a lot of opportunities and threats discussed. However, a compiled and industry-wide analysis of SWOTs is missing. After a review of the literature on digitization and sustainability and compiling a SWOT table, a concept map is developed for visualizing key topics in light of digitization and sustainability. In addition, for illustrating unconscious knowledge, two exemplifying systemic structural constellations are presented in this context as well. The results show immense tensions between sustainability and digitization, but also offer progressive patterns. In light of a development towards sustainability, digitization is both boon and bane and often needs a clear analysis of all relevant issues and a careful handling in order to be progressive. Digital transformation requires a precise and honest value basis and sustainability added value. Therefore, societal progress and strict law regulation will be needed.
Cognitive Deep Learning
Authors: Chowdhary Chiranji Lal , Darwish Ashraf , Hassanien Aboul Ella
Published: April 2019

Deep learning states the scientific algorithms that are accustomed to come through a particular assignment. Such tidy issues could also be meteorology or brain diagnosing wherever records are obtainable as text. In such a state of affairs, cognitive computing can help medical practitioners to diagnose patterns that they might not observe, and they will extend the flexibility to diagnose the brain with efficiency. Deep learning is additionally able to introduce new APIs.
A Case Study on Pre-Service English Teachers' Perceptions of Self-Efficacy and Integration of Information-Communication Technologies
Authors: Istifci Ilknur
Published: April 2019

The aim of this study is to find out pre-service English language teachers' ICT self-efficacy perceptions and ICT integration in their lessons. The data were collected from 60 pre-service English teachers in one of the state universities in Turkey via a questionnaire developed by Ekici, Ekici, and Kara. Semi-structured interviews were also carried out with some volunteering pre-service teachers. The questionnaire data were analyzed using the Statistical Package for Social Sciences (SPSS 22). Interview data were analyzed finding emerging themes and categorizing them using constant comparison method. The results showed that they use ICTs in their lessons mostly especially in practicum or macro and micro teaching sessions and they have high self-efficacy on ICT use in language education. Results also revealed some problems they encounter while using ICTs in language teacher education and their suggestions on how to improve their use. Based on the results, certain implications were drawn from the study in order to organize future teacher education programs that utilize ICTs.
Gender Issues in Vocational Education and Training in India
Authors: Singh Disha
Published: April 2019

The data unveils that India's workforce productivity is lower than that of many other developing countries. At the same time, India is also facing skill gap challenge because of the non-availability of skilled labor force in different sectors. There are very few adequately skilled workers in the employment system. Thus, multiple mismatches emerge, where on one side the sectors like manufacturing, crafts, etc. are desperately looking for skilled workers while on the other side the young job starters cannot find adequate employment. Also, India has a huge informal sector that employs more than 90% of all workers of the labor force and contributes in 60% of the country's economic output. If India is to become a major manufacturing power, then there should be the development of a network which can promote and reward skills and productivity. There should also be equal representation of gender in terms of participation in works and skill development. In 2011, out of a total workforce of 481.7 million, 149.9 million or 31% are women.
Personalizing Professional Development Through the Unconference
Authors: Shore Rebecca Ann , Morris Debra
Published: April 2019

This chapter shares a framework for personalizing professional development through which adult learners' needs are determined in real time and discussed and investigated at the time of need for educators. The model, referred to as an unconference or EdCamp, brings educators together, either physically on the same site or electronically, where needs are identified at the start of the meeting, then shared and addressed by those with similar needs. This chapter traces a brief history of professional development (PD) in P-12 schools from the emergence of the National Staff Development Council, now called Learning Forward, and reviews the evolution of evaluation models. It then traces a brief history of learning theory from Behaviorism to Constructivism, and the impact of the evolving understanding of how we learn on changing professional development delivery. The authors share advances from the sciences that have influenced the design and delivery of learning and offer a brain-based approach for delivering PD.
Determination of Factors Affecting the South East Asian Crisis of 1997 Probit-Logit Panel Regression
Authors: Kalkavan Hakan , Ersin Irfan
Published: April 2019

The economic crisis is an important event that hurts societies. Communication between the market and the authorities is an important factor in economic crisis situations. Because if the communication is established in a healthy way, economic crises in the future may not be repeated. In this context, the chapter deals with the economic crisis of 1997 in the Asian region as part of crisis communication. In the study conducted with Logit method, data belonging to the period 1975-2006 were used. In addition, the variables used frequently in the literature were considered as data set indicators. The results indicate that economic growth, financial credit, and money supply are important indicators affecting the crisis. Indeed, the emergence of the crisis with these variables reveals that there was a communication problem in the Asian region. Considering this experience, it has been suggested that Asia and other countries should care about the communication tools.
Determination of the Open Risers more Effective Zone for Steel Wheel Casts
Authors: Suárez Lisca Lázaro Humberto , Delgado Sobrino Daynier Rolando , Coello Machado Norge Isaias
Published: April 2019

The manufacture by casting, remains the most economical way to obtain pieces with complex geometries and diverse alloys. This is a highly complex process given the large number of variables and factors involved in it, thus, when one of these is ignored and/or left out of control, process errors and distortions usually occur. The present paper introduces a design of experiment of the type: Central Composite Design (22) + Star, that took into account the variation of important parameters in the pouring, solidification and cooling process, such as pouring temperature and pouring ratio, and that also added the “coefficient factor” relating the geometric parameters of the risers. This design studied the factors ‘effects in 16 runs, including 2 central points per block, with the aim of finding the best working area of the risers and the optimal values of the parameters studied under specific conditions. The statistical processing of the data obtained showed the relationships between the parameters studied and the different regression equations. The results obtained allowed to establish new procedures and work volumes for the risers in order to reduce the consumption of material during the process.
Fluidity of Rubber and TPE Influenced by Mold Surface Roughness
Authors: Stanek Michal , Ovsik Martin , Manas Miroslav , Reznicek Martin , Fluxa Petr
Published: April 2019

Injection molding is one of the most extended plastic processing technologies. Delivery of polymer melts into the mold cavity is the most important stage of the injection molding process. This paper shows the influence of mold cavity surface roughness and technological parameters on the flow length of thermoplastic elastomers and rubber into mold cavity. The fluidity of polymers is affected by many parameters (mold design, melt temperature, injection rate and pressures) and by the flow properties of polymers. Evaluation of the data obtained by experiments where the testing conditions were widely changed shows that quality of the cavity surface does not affect the length of flow.
The Research of Influence of Strain Rate in Steel Tube Cold Drawing Processes Using FEM Simulation
Authors: Kapustová Mária , Sobota Róbert
Published: April 2019

The technology of cold die drawing of tubes is used for processing of metals and alloys with good or worse formability, while the tube production itself is affected by various process parameters, i. e. mostly die geometry, strain degree and strain rate, force conditions, conditions of friction, method of lubrication and type of used lubricant. The paper is concerned with an evaluation of influence of the selected process parameters, i. e. drawing tool geometry and strain rate on plastic flow and energy intensity of the process of cold die drawing of tubes. The FEM analysis of the drawing process was an important aid for this research. The computer simulation resulted in interesting graphs illustrating the influence of the shape of the drawing tool reduction cone on the size of the drawing force at various strain rates.
Laser Hardening of Large Cast Iron Castings and their Diagnostics Using Magnetic Spot Method
Authors: Skrbek Břetislav , Nosek Vladimír
Published: April 2019

Principle, significance and history of cast iron surface hardening. Benefit of high-energy heat sources. Cast iron resistance against thermal shock. Production of large surface hardening. Measurement of its depth and hardness - hardening depth definition of cast iron. Practical results and experience with large castings for machine tools. Research of diagnostics of magnetic spot method application. Optimization of diagnostics of layer depth and hardness using special developed non-destructive structuroscope DOMENA ZL.
Toxicity Evaluation of Graphene and Poly(Lactic-Acid) Using a Nematode Model
Authors: Kong Cin , Aziz Azzahraa Izzati , Kakarla Akesh Babu , Kong Ing , Kong Wei
Published: April 2019

Graphene has gained tremendous attention due to its unlimited potential in various applications while poly(lactic acid) (PLA) is a biodegradable thermoplastic polyester produced from fermenting corn starch. The incorporation of graphene into PLA has been proven to exhibit excellent mechanical and thermal properties. However, there are not many reports on the potential toxic effect of these materials towards living organisms. In this study, we investigated the possible toxicity of graphene and PLA-graphene in a live animal model, the nematode Caenorhabdits elegans (C. elegans). Alive adult worms were exposed directly to graphene and PLA-graphene across a range of concentrations from 50 µg/mL to 1000 µg/mL. After certain hours of exposure, the pharyngeal pumping rate (indicative of the C. elegans feeding activity), reproductive rate and lifespan of the worms were determined and compared to the untreated worm population. At all concentrations tested, both graphene and PLA-graphene do not affect the feeding rate of the nematode. Additionally, there was no significant difference between the lifespan of worms exposed to graphene and PLA-graphene as compared to the untreated control population (p>0.05). We examined the effect of graphene on nematode’s ability to reproduce and no reduction in progenies was detected (p>0.05). Taken together, our findings suggest that graphene and PLA-graphene do not possess a negative effect on the feeding activity, reproduction and overall lifespan of the host, indicating that these materials are safe to living organism at concentration up to 1000 µg/mL.
Aluminum Nitride Thin Films Grown by Sol-Gel Spin Coating Technique
Authors: Mohd Isa Nurul Atikah , Ng Sha Shiong , Hassan Zainuriah
Published: April 2019

In this study, aluminum nitride (AlN) thin films were grown on p-type silicon (100) substrate by sol-gel spin coating method. Two types of ethanol-based precursors were prepared, namely, precursors with and without the aid of diethanolamine (DEA). The objective of this work is to investigate the effects of the DEA on the surface morphology, structural and optical properties of the deposited thin films. The coating films were undergone nitridation process under ammonia ambient at 1100 °C for 60 min. The surface morphology and structural properties of the deposited AlN thin films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). XRD results revealed that both samples have AlN (100) preferred orientation. In addition, the crystallinity of sample without the aid of DEA is higher compared to the sample prepared with DEA. While, the AFM results showed that both samples have uniform and smooth surface. The optical properties of AlN thin films was investigated by Raman spectroscopy. For sample without DEA, Raman results showed the present of wurtzite AlN characteristics phonon modes of E2(high) and A1(LO) at 660 cm-1 and 892 cm-1, respectively. Whereas only E2(high) is observed for sample with the aid of DEA. Finally, all the results revealed that the present of DEA has a strong influence on the properties of deposited AlN thin films and film prepared without DEA have better quality.
Er3+/Nd3+ Codoped Lithium Niobate Tellurite Glass: Improvement in Energy Transfer Induced Photoluminescence
Authors: Nurhafizah Hasim , Rohani Md Supar
Published: April 2019

The Er3+/Nd3+ doped glasses of the form (69-x)TeO2-15Li2CO3-15Nb2O5-1Er2O3-(x)Nd2O3 with x=0.4, 0.8 and 1.0 mol % are successfully made by using conventional melt-quenching technique. It was found both the photoluminescence intensity and stimulated emission cross-section were found increase with Nd3+ codoping. Efficient blue (497 nm, 2G9/2 → 4I9/2), green (550 nm, 2G7/2 → 4I9/2), orange (618 nm, 2H11/2→4I9/2), and red (635 nm, 4F9/2→4I9/2) spectra were observed. The results suggest that the present glass shows the potential candidate of broadband amplifiers and lasers as it is comparable with other Nd3+ doped other host.
Morphology Controlled Synthesis of ZnO Nanorods for Glucose Enzymatic Biosensor
Authors: Nur Syafinaz Ridhuan , Khairunisak Abdul Razak , Lockman Zainovia
Published: April 2019

The use of zinc oxide nanorods is a promising option to increase the specific area for efficient glucose oxidase immobilization which further enhance the signal performance of glucose detection. In this work ZnO nanorods were prepared via hydrothermal process on sol-gel ZnO seed layer. The effects of different temperature of annealed seed layer on the morphology and properties of grow ZnO nanorods were investigated. The ZnO seed layers were annealed at various temperatures ranging from 300 to 600 °C for 2 h. The study demonstrated that the process condition of ZnO seed layer had a strong influence on the morphology and crystallinity of ZnO nanorods grow. X-ray diffraction analysis and scanning electronic microscopy were employed to characterize the crystal structure and morphology of the prepared ZnO seed layer and grow ZnO nanorods. The performance of different aspect ratio of ZnO nanorods on glucose detection were measured by using electrochemical analysis. With optimized ZnO nanorods, the glucose biosensor exhibited an enhanced in signal performance with a high sensitivity of 11.36 μA mM-1 cm-2 in the range of 0.05-1 mM. Such high performance was due to more immobilization on the well-aligned ZnO nanorods array and direct electron conduction between the nanorods and the electrodes
Determining Integrity in 5,000 Feet of Water Following a Major Incident
Authors: Wisch David
Published: April 2019

Prior to the completion of installation of the Big Foot TLP, 9 of 16 pre-installed tendons fell to the seafloor. Seven of the tendon assemblies were reverse installed. Nine of the tendons lay on the seafloor with the lower connector assemblies remaining within the piles and receptacle device. A critical go forward decision was determination of reusability of the pile/receiver assemblies. The pile/receiver assemblies were located in over 5,000 feet of water. Novel technology application and deployment was needed to clear the site, inspect remaining components, determine integrity and adequacy. The decision was time bound as go-forward decisions relied on the outcome of the study.

This paper outlines the fallen condition, development of criteria to assure adequacy, identification of technologies sufficient to determine adequacy, interpretation of the data, engineering assessment and final decisions. Initial clearing of site included removal of lower tendon sections and connectors without incurring damage to the pile assembly was required. Marinizing inspection tools, templates, etc. for both accuracy and repeatability was required. The novel and successful execution starting with "as is" condition through design, deployment and results will be highlighted. One key element was mapping the after-incident conditions to the design tolerances.

Developing tools and operating procedures to assure measuring tolerances and repeatability required new methods and procedures that proved successful. For a first of kind and unique challenge, the importance of starting with first principles and initial acceptance criteria, identifying technologies and tools available to match, followed by selection of most likely to succeed in extending existing tools for success is illustrated.
Application of a Transient Deposition Model for Hydrate Management in a Subsea Gas-Condensate Tieback
Authors: Charlton Thomas B. , Kegg Stuart , Morgan Julie E. P. , Zerpa Luis E. , Koh Carolyn A. , May Eric F. , Aman Zachary M.
Published: April 2019

This study provides valuable insights into hydrate management strategies as the industry transitions away from complete hydrate avoidance, particularly for the development of deep-water reservoirs with stricter economic margins. Transient simulation tools, such as the deployed hydrate deposition model, extend our ability to estimate blockage likelihood from heuristics to quantitative predictions. The model is applied to an insulated subsea tieback to identify the optimal no-touch-time (NTT) and depressurization pressure (DPP) following an unplanned shutdown. Two water-production scenarios are considered, from the lowest expected to the highest manageable rates. A complete hydrate blockage is predicted when the NTT was extended several hours beyond the nominal value for the highest water-to-gas ratio (WGR). Complete blockages are predicted for both low and high WGRs when the flowline is only partially depressurized, however, longer cooldown times for the high WGR case (due to greater volumes of residual liquids) meant a blockage took more than twice as long to occur than for the low WGR case. Fully depressurized restarts are both difficult and time consuming, leading to hydrate volume fractions (with respect to the pipe volume) exceeding 30 vol.%. An alternative hydrate management strategy is identified for cases with high volumes of water production, in which the flowline is only partially depressurized once the nominal NTT has elapsed, utilising the increased heat capacity of residual liquids. This reduces the quantity of gas sent to flare and simplifies the restart procedure.
What Offshore CCS Will Look Like in the Gulf of Mexico - Perspectives from Texas
Authors: Meckel Tip A , Hovorka Sue , Trevino Ramon
Published: April 2019

Since 2009, the Gulf Coast Carbon Center at the Bureau of Economic Geology (The University of Texas at Austin) has undertaken multiple integrated geologic and geophysical studies to evaluate the continental shelf in the Gulf of Mexico for CO2 storage. Funding for these studies has come primarily from the U.S. Department of Energy (NETL), but also from the State of Texas General Land Office, which administers the State offshore resources. A recent award-winning publication (BEG Report of Investigations No. 283) compiles the diverse topics explored during this long history of characterization: Geological CO2 Sequestration Atlas for Miocene Strata Offshore Texas State Waters. This is the first attempt to comprehensively address CO2 storage topics for the near offshore in the Gulf Coast. Topics addressed in the volume include Miocene stratigraphy and depositional systems with regional cross sections, implications of petroleum systems for CO2 storage, microscopic and stratigraphic evaluation of anticipated primary seals, regional static capacity estimates, and field-scale examples of storage reservoirs (including modelling and simulation). Detailed stratigraphic and structural interpretation of hundreds of wells and faults using integrated 3D seismic data is now continuous over an area greater than 5,000 square kilometres (2,000 square miles). In three localities a total of 137 square kilometres (53 square miles) of novel high-resolution 3D seismic data has been acquired to understand technological capabilities for imaging the overburden above injection reservoirs, and to address characterization, risk reduction, and monitoring needs. General conclusions from this work are that the inner shelf of the Gulf of Mexico presents superb geology for CCS with ample storage capacity. Sources and developing pipeline infrastructure are well located for development of offshore storage hubs. The thick and relatively young and porous clastic Miocene stratigraphy has multiple regional confining intervals deposited during regional sea level transgressions. Static CO2 storage capacity estimates beneath the Texas State waters between Mexico and Louisiana total more than 30 Gt, including both depleted hydrocarbon reservoirs and saline intervals. More regional assessments identify approximately 125 Gt of storage. This offshore geologic CO2 storage resource is regionally and nationally significant, is available for both CO2 sequestration and enhanced oil recovery (EOR), and is likely to be the most appropriate region for giga-tonne scale storage in the United States.
A Case Study – A Systems Approach for 20 ksi Equipment Qualification
Authors: Raney James Brian , Walz Gregg , Kaminski Dennis , Moscalu Stella , Dighe Sourabh , Maguire Pat Glen , Peurifoy Charles Kenneth , Quates Ron Duane , Rettie Stuart Douglas , Swider Jan , Wilson Alan Lee , Baskett David Charles , Boster Patrick , Byrd Mike , Dickerson Gregg , Douglas Scherie , Gallo Charley Daniel , Graff Richard Lee , Hennig Jake , Hodge Quincy Michael , Kluk Dan Joseph , Pham Man , Rowe Adam C , Smiles Les John , Urquhart Robert James , Parker Wanda June
Published: April 2019

Anadarko started the initial development and qualification of 20 ksi equipment in 2013 for a Gulf of Mexico (GoM) project. That journey included an analysis of using depth-adjusted working pressure of 15 ksi equipment that allowed exploration and appraisal drilling of a high-pressure GoM prospect. It continued with the goal to develop and qualify a complete set of 20 ksi equipment for a deepwater GoM high-pressure development. The scope of development and qualification of High-Pressure, High-Temperature (HPHT) equipment included:

20 ksi deepwater Mobile Offshore Drilling Unit (MODU);

20 ksi subsea Blowout Preventer (BOP);

20 ksi Completions equipment for the upper completion including a subsurface safety valve, packers, chemical injection, wireline plugs, etc.;

20 ksi Intervention equipment including a thru-riser intervention string, a Tree Tieback Tool, workstring connection and an Integrated Workover Control System (IWOCS);

20 ksi Subsea Production equipment including wellhead, tree and a High Integrity Pressure Protection System (HIPPS).

Anadarko formed the ‘20A project team’ initiative in order to qualify these critical deepwater components with a Rated Working Pressure (RWP) greater than 15 ksi. This project is coming to a close in 2019, with the qualification of over 200 components and assemblies to industry standards and meeting U.S. government requirements. This six year development journey of 20 ksi equipment development and qualification presented challenges and achieved breakthrough technologies for the industry. This journey, its organizational approach using systems engineering techniques and integration processes are presented.