bluuebunny/crossref_metadata_2025 huggingface dataset:
Vortex Dynamics Study of the Canard Deflection Angles’ Influence on the Sukhoi Su-30-Like Model to Improve Stall Delays at High AoA
Authors: Sutrisno  , Rohmat Tri Agung , Wibowo Setyawan Bekti , Iswahyudi Sigit
Published: February 2019

The maneuverability of the Sukhoi Su-30 at very high angles of attack (AoA) was remarkably appealing. Canard angle, in cooperation with aircraft wing, created a flow pattern whereby, in that position, the fighter still had as much lifting force as possible in order not to stall. The behavior of changing canard angle configuration played an essential role in creating the strong vortex core so that it could delay the stall. The study of vortex dynamics at canard deflection angle gave an essential function in revealing the stall delay phenomenon. In this study, one could analyze the flow patterns and vortex dynamics ability of the Sukhoi Su-30-like model to delay stall due to the influence of canard deflection. The used of water tunnel facilities and computational fluid dynamics (CFD) based on Q-criterion has obtained clear and detailed visualization and aerodynamics data in revealing the phenomenon of vortex dynamics. It was found that between 30° and 40° canard deflection configurations, Sukhoi Su-30-like was able to produce the most robust flow interaction from the canard to the main wing. It was clearly seen that the vortex merging formation above the fighter heads was clearly visible capable of delaying stall until AoA 80°.
The Efficiencies, Environmental Impacts and Economics of Energy Consumption for Groundwater-Based Irrigation in Oklahoma
Authors: Handa Divya , Frazier Robert S. , Taghvaeian Saleh , Warren Jason G.
Published: February 2019

Irrigation pumping is a major expense of agricultural operations, especially in arid/semi-arid areas that extract large amounts of water from deep groundwater resources. Studying and improving pumping efficiencies can have direct impacts on farm net profits and on the amount of greenhouse gases (GHG) emitted from pumping plants. In this study, the overall pumping efficiency (OPE), the GHG emissions, and the costs of irrigation pumping were investigated for electric pumps extracting from the Rush Springs (RS) aquifer in central Oklahoma and the natural gas-powered pumps tapping the Ogallala (OG) aquifer in the Oklahoma Panhandle. The results showed that all electric plants and the majority of natural gas plants operated at OPE levels below achievable standard levels. The total emission from the plants in the OG region was 49% larger than that from plants in the RS region. However, the emission per unit irrigated area and unit total dynamic head of pumping was 4% smaller for the natural gas plants in the OG area. A long-term analysis conducted over the 2001–2017 period revealed that 34% and 19% reductions in energy requirements and 52% and 20% decreases in GHG emissions can be achieved if the OPE were improved to achievable standards for plants in the RS and OG regions, respectively.
Assessment of Heterosis Based on Genetic Distance Estimated Using SNP in Common Wheat
Authors: Nie Yingbin , Ji Wanquan , Ma Songmei
Published: February 2019

This study assessed the genetic distance (GD) between parental genotypes using single nucleotide polymorphism (SNP) DNA markers and evaluated the correlation between GD and heterosis in common wheat. We examined the performance of parents and hybrids in a field experiment conducted in a randomized block design at a Shihezi location with three replications. Different traits such as the height of the parents and the F1 generation, number of harvested ears, number of grains per panicle, grain weight per panicle, 1000-grain weight, and grain yield were examined. Genotyping using a wheat 90K SNP chip determined the GD between the parents and analyzed the relationship between GD and heterotic performance of hybrids in wheat. Cluster analysis based on GD estimated using SNP chips divided the 20 elite parents into five groups which were almost consistent with the parental pedigree. Correlation analysis showed a significant association between GD and mid-parent heterosis (MPH) of 1000-grain weight. However, GD and high-parent heterosis (HPH) of 1000-grain weight showed no significant correlation. There was a weak correlation between GD and with spikelet number, harvested spikes, and yield at MPH or HPH. Hence, SNP analysis may be utilized in allocating wheat parents to heterotic groups. However, the correlation between SNP-based GD and hybrid performance still remains unclear.
Euthanasia: Manual versus Mechanical Cervical Dislocation for Broilers
Authors: Jacobs Leonie , Bourassa Dianna V. , Harris Caitlin E. , Buhr R. Jeff
Published: February 2019

The aim was to assess the onset of brain stem death for two euthanasia methods—manual cervical dislocation (CD) versus the Koechner Euthanizing Device (KED). Over three days broilers of 36 (n = 60), 42 (n = 80), or 43 days old (n = 60) were euthanized. On days 2 and 3, a treatment was added in which the bird’s head was extended at a ~90° angle after application of the KED (KED+). On those days, gap size was recorded between the skull and atlas vertebra by 1-cm increments. The onset of brain death was assessed by recording the nictitating membrane reflex, gasping reflex and musculoskeletal movements (sec). Additionally, skin damage and blood loss were recorded (y/n). On all days, CD resulted in quicker loss of reflexes and movements compared to KED or KED+. Reflexes returned in 0–15% of CD birds, 50–55% of KED birds, and 40–60% of KED+ birds, possibly regaining consciousness. Skin damage occurred in 0% of CD birds, 68–95% of KED birds, and 85–95% of KED+ birds. On day 2 (p = 0.065) and 3 (p = 0.008), KED birds had or tended to have a narrower skull-to-atlas gap compared to CD and KED+ birds. Based on our results, CD would be the recommended method for broilers.
Influence of Soil Pore System Properties on the Degradation Rates of Organic Substances during Soil Aquifer Treatment (SAT)
Authors: Fichtner Thomas , Goersmeyer Nora , Stefan Catalin
Published: February 2019

Soil aquifer treatment (SAT) is a nature-inspired solution for improving the water quality through soil percolation. The biodegradation of organic matter typically occurs in the shallowest soil layer and it depends on the contaminant’s characteristics (water solubility, molecular structure) and specific soil properties (pore size distribution). The present study aims at identifying which grain size fraction of typically used sandy soils in the shallowest layer of SAT systems can provide the optimal conditions for microbiological growth that can be reached by a trade-off between soil moisture as well as nutrients and oxygen supply. For this, soil columns were used at a laboratory scale to determine the relationship between the pore size distribution of four different grain size fractions and biodegradation rates of organic matter from synthetic wastewater. The results obtained from this experimental setup indicate that bacterial colonies reached optimum growth when about 60% of the available pore space was filled with water. For the selected soil, this was achieved by the fraction with grain sizes in the range of 630 µm to 1000 µm, having pore diameters between 87 µm and 320 µm and a mean pore diameter of 230 µm.
Monitoring Electrochemical Reactions in Situ with Low Field NMR: A Mini-Review
Authors: Gomes Bruna Ferreira , Lobo Carlos Manuel Silva , Colnago Luiz Alberto
Published: February 2019

The number of applications of time domain NMR using low-field spectrometers in research and development has been steadily increasing in recent years with applications ranging from quality control of industrial products to the study of physical and chemical properties of a wide array of solid and liquid samples to, most recently, electrochemical studies. In this mini-review we summarize the progress that has been achieved in the coupling between time domain NMR (using low-field spectrometers) and electrochemistry and how the challenges that this coupling poses have been overcome over the years. We also highlight the effect that the static magnetic field of the NMR spectrometer has on the electrochemical systems.
The Role of Nanotechnology in the Fortification of Plant Nutrients and Improvement of Crop Production
Authors: Elemike Elias E. , Uzoh Ifeyinwa Monica , Onwudiwe Damian C. , Babalola Olubukola Oluranti
Published: February 2019

Nutrient deficiency in food crops is seriously affecting human health, especially those in the rural areas, and nanotechnology may become the most sustainable approach to alleviating this challenge. There are several ways of fortifying the nutrients in food such as dietary diversification, use of drugs and industrial fortification. However, the affordability and sustainability of these methods have not been completely achieved. Plants absorb nutrients from fertilizers, but most conventional fertilizers have low nutrient use and uptake efficiency. Nanofertilizers are, therefore, engineered to be target oriented and not easily lost. This review surveys the effects of the addition of macro- and nanonutrients to soil, the interaction, and the absorption capability of the plants, the environmental effect and food content of the nutrients. Most reports were obtained from recent works, and they show that plants nutrients could be enriched by applying nanoparticulate nutrients, which are easily absorbed by the plant. Although there are some toxicity issues associated with the use of nanoparticles in crop, biologically synthesized nanoparticles may be preferred for agricultural purposes. This would circumvent the concerns associated with toxicity, in addition to being pollution free. This report, therefore, offers more understanding on the application of nanotechnology in biofortification of plant nutrients and the future possibilities offered by this practice. It also highlights some of the ills associated with the introduction of nanomaterials into the soil for crop’s improvement.
Deep Electrical Modulation of Terahertz Wave Based on Hybrid Metamaterial-Dielectric-Graphene Structure
Authors: Xia Liangping , Zhang Xin , Zhang Man , Dang Suihu , Huang Shijian , Tan Yong , Yan Wenjuan , Cui Hong-Liang
Published: February 2019

A terahertz modulation structure based on hybrid metamaterial and graphene is proposed and demonstrated in this work. The metamaterial with a square slit ring array excites terahertz resonance in the slits and enhances the interaction between the terahertz wave and graphene. The graphene layer acting as the active material is tuned by the applied electrical field. With the separation by a dielectric layer between the graphene and the metallic structure, the resonant frequency and transmitted energy are both modulated by the graphene. Experimental result indicates that the modulation depth of the terahertz transmitted amplitude is 65.1% when the applied modulation voltage is tuned 5 V.
Summertime Aerosol over the West of Ireland Dominated by Secondary Aerosol during Long-Range Transport
Authors: Lin Chunshui , Ceburnis Darius , Huang Ru-Jin , Canonaco Francesco , Prévôt André Stephan Henry , O'Dowd Colin , Ovadnevaite Jurgita
Published: February 2019

The chemical composition and sources of non-refractory submicron aerosol (NR-PM1) on Galway, a west coast city of Ireland, were characterized using an aerosol chemical speciation monitor during summertime in June 2016. Organic aerosol (OA) was found to be the major part of NR-PM1 (54%), followed by secondary inorganic sulfate (25%), ammonium (11%), and nitrate (10%). Factor analysis revealed that oxygenated OA (OOA) was the dominant OA factor, on average accounting for 84% of the total OA. The remaining 16% of OA was attributed to primary peat burning associated with domestic heating activities. As a result, secondary organic and inorganic aerosol together accounted for 91% of the total NR-PM1, pointing to an aged aerosol population originating from secondary formation during long-range transport. Concentration-weighted trajectory analysis indicated that these secondary aerosols were mainly associated with easterly long-range transport from the UK and/or France.
Best Proximity Point Theorems on Rectangular Metric Spaces Endowed with a Graph
Authors: Souayah Nizar , Aydi Hassen , Abdeljawad Thabet , Mlaiki Nabil
Published: February 2019

In this paper, we ensure the existence and uniqueness of a best proximity point in rectangular metric spaces endowed with a graph structure.
Complex Soliton Solutions to the Gilson–Pickering Model
Authors: Baskonus Haci Mehmet
Published: February 2019

In this paper, an analytical method based on the Bernoulli differential equation for extracting new complex soliton solutions to the Gilson–Pickering model is applied. A set of new complex soliton solutions to the Gilson–Pickering model are successfully constructed. In addition, 2D and 3D graphs and contour simulations to the complex soliton solutions are plotted with the help of computational programs. Finally, at the end of the manuscript a conclusion about new complex soliton solutions is given.
Integrating Small Animal Irradiators with Functional Imaging for Advanced Preclinical Radiotherapy Research
Authors: Ghita Mihaela , Brown Kathryn H. , Kelada Olivia J. , Graves Edward E. , Butterworth Karl T.
Published: February 2019

Translational research aims to provide direct support for advancing novel treatment approaches in oncology towards improving patient outcomes. Preclinical studies have a central role in this process and the ability to accurately model biological and physical aspects of the clinical scenario in radiation oncology is critical to translational success. The use of small animal irradiators with disease relevant mouse models and advanced in vivo imaging approaches offers unique possibilities to interrogate the radiotherapy response of tumors and normal tissues with high potential to translate to improvements in clinical outcomes. The present review highlights the current technology and applications of small animal irradiators, and explores how these can be combined with molecular and functional imaging in advanced preclinical radiotherapy research.
Antimicrobial Peptide TP4 Induces ROS-Mediated Necrosis by Triggering Mitochondrial Dysfunction in Wild-Type and Mutant p53 Glioblastoma Cells
Authors: Su Bor-Chyuan , Pan Chieh-Yu , Chen Jyh-Yih
Published: February 2019

Antimicrobial peptide tilapia piscidin 4 (TP4) from Oreochromis niloticus exhibits potent bactericidal and anti-tumorigenic effects. In a variety of cancers, the mutation status of p53 is a decisive factor for therapeutic sensitivity. Therefore, we investigated the impact of p53 status on TP4-induced cytotoxicity in glioblastoma cell lines and the molecular mechanisms that govern cytotoxic effects. Both U87MG (wild-type/WT p53) and U251 (mutant p53) glioblastoma cell lines were sensitive to TP4-induced cytotoxicity. The necrosis inhibitors Necrostatin-1 and GSK’872 attenuated TP4-induced cytotoxicity, and TP4 treatment induced the release of cyclophilin A, a biomarker of necrosis. Moreover, TP4 induced mitochondrial hyperpolarization and dysfunction, which preceded the elevation of intracellular reactive oxygen species, DNA damage, and necrotic cell death in both U87MG and U251 glioblastoma cells. p38 was also activated by TP4, but did not contribute to cytotoxicity. SB202190, a specific p38 inhibitor, enhanced TP4-induced oxidative stress, mitochondrial dysfunction, and cytotoxicity, suggesting a protective role of p38. Furthermore, TP4-induced cytotoxicity, oxidative stress, phosphorylation of p38, and DNA damage were all attenuated by the mitochondrial-targeted reactive oxygen species (ROS) scavenger MitoTEMPO, or the reactive oxygen species scavenger N-acetyl-L-cysteine. Based on these data, we conclude that TP4 induces necrosis in both WT and mutant p53 glioblastoma cells through a mitochondrial ROS-dependent pathway.
Enter the Tubes: Carbon Nanotube Endohedral Catalysis
Authors: Iglesias Daniel , Melchionna Michele
Published: February 2019

The unique morphological characteristics of carbon nanotubes (CNTs) present the intriguing opportunity of exploiting the inner cavity for carrying out chemical reactions. Such reactions are catalysed either by the individual tubes that function both as catalysts and nanoreactors or by additional catalytic species that are confined within the channel. Such confinement creates what is called “confinement effect”, which can result in different catalytic features affecting activity, stability and selectivity. The review highlights the recent major advancements of catalysis conducted within the CNTs, starting from the synthesis of the catalytic composite, and discussing the most notable catalytic processes that have been reported in the last decade.
Tuning the Catalytic Properties of Copper-Promoted Nanoceria via a Hydrothermal Method
Authors: Kappis Konstantinos , Papadopoulos Christos , Papavasiliou Joan , Vakros John , Georgiou Yiannis , Deligiannakis Yiannis , Avgouropoulos George
Published: February 2019

Copper-cerium mixed oxide catalysts have gained ground over the years in the field of heterogeneous catalysis and especially in CO oxidation reaction due to their remarkable performance. In this study, a series of highly active, atomically dispersed copper-ceria nanocatalysts were synthesized via appropriate tuning of a novel hydrothermal method. Various physicochemical techniques including electron paramagnetic resonance (EPR) spectroscopy, X-ray diffraction (XRD), N2 adsorption, scanning electron microscopy (SEM), Raman spectroscopy, and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) were employed in the characterization of the synthesized materials, while all the catalysts were evaluated in the CO oxidation reaction. Moreover, discussion of the employed mechanism during hydrothermal route was provided. The observed catalytic activity in CO oxidation reaction was strongly dependent on the nanostructured morphology, oxygen vacancy concentration, and nature of atomically dispersed Cu2+ clusters.
Control of the Antitumor Immune Response by Cancer Metabolism
Authors: Domblides Charlotte , Lartigue Lydia , Faustin Benjamin
Published: February 2019

The metabolic reprogramming of tumor cells and immune escape are two major hallmarks of cancer cells. The metabolic changes that occur during tumorigenesis, enabling survival and proliferation, are described for both solid and hematological malignancies. Concurrently, tumor cells have deployed mechanisms to escape immune cell recognition and destruction. Additionally, therapeutic blocking of tumor-mediated immunosuppression has proven to have an unprecedented positive impact in clinical oncology. Increased evidence suggests that cancer metabolism not only plays a crucial role in cancer signaling for sustaining tumorigenesis and survival, but also has wider implications in the regulation of antitumor immune signaling through both the release of signaling molecules and the expression of immune membrane ligands. Here, we review these molecular events to highlight the contribution of cancer cell metabolic reprogramming on the shaping of the antitumor immune response.
Pro-Thrombotic Activity of Blood Platelets in Multiple Sclerosis
Authors: Saluk-Bijak Joanna , Dziedzic Angela , Bijak Michal
Published: February 2019

The available data, including experimental studies, clearly indicate an excessive intravascular activation of circulating platelets in multiple sclerosis (MS) and their hyper-responsiveness to a variety of physiological activators. Platelet activation is manifested as an increased adhesion and aggregation and is accompanied by the formation of pro-thrombotic microparticles. Activated blood platelets also show an expression of specific membrane receptors, synthesis many of biomediators, and generation of reactive oxygen species. Epidemiological studies confirm the high risk of stroke or myocardial infarction in MS that are ischemic incidents, strictly associated with incorrect platelet functions and their over pro-thrombotic activity. Chronic inflammation and high activity of pro-oxidative processes in the course of MS are the main factors identified as the cause of excessive platelet activation. The primary biological function of platelets is to support vascular integrity, but the importance of platelets in inflammatory diseases is also well documented. The pro-thrombotic activity of platelets and their inflammatory properties play a part in the pathophysiology of MS. The analysis of platelet function capability in MS could provide useful information for studying the pathogenesis of this disease. Due to the complexity of pathological processes in MS, medication must be multifaceted and blood platelets can probably be identified as new targets for therapy in the future.
Nanocomposites of Barium Titanate Nanoparticles Embedded in Thermosetting Polymer Matrices (Novolac Resin/Unsaturated Polyesters/Epoxy Resin): A Comparative Study
Authors: Asimakopoulos Ioannis A. , Psarras Georgios C. , Zoumpoulakis Loukas
Published: February 2019

Polymer matrix nanocomposites with embedded ferroelectric barium titanate particles were developed and characterized. The utility of such nanocomposites is the energy storage capability that they exhibit, besides their low weight and cost, in comparison to materials that are customarily used for this purpose. The polymers that have been used as matrices in the composites belong to the three most usable thermosetting polymer resins (novolacs, unsaturated polyesters, and epoxy resins), were either laboratory synthesized or commercially supplied. Structure and morphology of the produced composite specimens were studied via Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), and Fourier Transformation Infrared Spectroscopy (FTIR). Thermal, mechanical and electrical performance was examined via Differential Scanning Calorimetry (DSC), bending and shear strength tests (three-point method), and Broadband Dielectric Spectroscopy (BDS), respectively. Mechanical shear and bending strength values were determined, as well as mechanical failure mode (brittle or elastomer) were estimated. Dielectric measurements disclosed the presence of four relaxation processes (α-mode, β-mode, and γ-mode) and Interfacial Polarization between the system’s constituents. The comparative study ended with the calculation of energy density, so that the energy storing capability could be estimated.
The Methanol Adsorption in Microporous Alumina Agglomerates
Authors: Dragan Grygorii , Kutarov Volodymyr , Poletaiev Mykola , Kolesnykov Kyrylo , Khlebnikova Mariya
Published: February 2019

We have studied theoretical and experimental methods of methanol adsorption in micropores of aluminum oxide agglomerates obtained by gas-dispersion synthesis. It is shown that the necessity to use strict equations based on the theory of volume filling of micropores, which implies a physical and formal analogy between the volume filling of micropores and capillary condensation, for qualitative and quantitative description of adsorption equilibrium in open slit-like micropores. The applicability of the proposed equations for the description of adsorption equilibrium in such systems is demonstrated on the example of experimental methanol adsorption/desorption isotherm on the aluminum oxide, which possesses a microporous structure.
Atomic Structure of Decagonal Al-Cu-Rh Quasicrystal–Revisited: New Correction for Phonons
Authors: Strzalka Radoslaw , Buganski Ireneusz , Kuczera Pawel , Pytlik Lucjan , Wolny Janusz
Published: February 2019

The standard approach applies the Gaussian distribution function to estimate atomic displacements due to thermal vibrations in periodic and aperiodic systems, which is used in a form of the Debye–Waller factor during the structure refinement. Acoustic phonons provide the largest contribution to the Gaussian correction although the character of other phonon modes remains relatively unclear. In this paper, we provide an alternative description of localized and dispersionless phonons based on an assumption of the harmonic displacement distribution function, which was recently proposed for model quasicrystals, and apply this approach for a decagonal Al-Cu-Rh quasicrystal that was previously studied by Kuczera et al. in 2012. We used the same X-ray diffraction data and the statistical method of structural analysis of the aperiodic systems. The correction function for phonons takes the form of a Bessel function instead of a conventional (Gaussian) Debye–Waller factor. This allowed us to achieve R-factor of 7.2% compared to 7.9% reported in the original paper. A significant improvement of the calculated atomic composition towards experimentally obtained and minor positional changes is also reported compared to the original paper. The results show the usefulness of investigating different corrective terms for diffraction data during a structure refinement.
Probability Study on the Thermal Stress Distribution in Thick HK40 Stainless Steel Pipe Using Finite Element Method
Authors: Bobba Sujith , Abrar Shaik , Rehman Shaik Mujeebur
Published: February 2019

The present work deals with the development of a finite element methodology for obtaining the stress distributions in thick cylindrical HK40 stainless steel pipe that carries high-temperature fluids. The material properties and loading were assumed to be random variables. Thermal stresses that are generated along radial, axial, and tangential directions are generally computed using very complex analytical expressions. To circumvent such an issue, probability theory and mathematical statistics have been applied to many engineering problems, which allows determination of the safety both quantitatively and objectively based on the concepts of reliability. Monte Carlo simulation methodology is used to study the probabilistic characteristics of thermal stresses, and was implemented to estimate the probabilistic distributions of stresses against the variations arising due to material properties and load. A 2-D probabilistic finite element code was developed in MATLAB, and the deterministic solution was compared with ABAQUS solutions. The values of stresses obtained from the variation of elastic modulus were found to be low compared to the case where the load alone was varying. The probability of failure of the pipe structure was predicted against the variations in internal pressure and thermal gradient. These finite element framework developments are useful for the life estimation of piping structures in high-temperature applications and for the subsequent quantification of the uncertainties in loading and material properties.
Factors Associated with Accessing Prison Dental Services in Scotland: A Cross-Sectional Study
Authors: Freeman Ruth , Richards Derek
Published: February 2019

Background: Prisoners have poorer dental health than non-prison populations. It is known that the prison environment can promote health and thus, policies, including access to dental care, are in place to promote health during imprisonment. Aim: Our aim was to conduct an oral health and psychosocial needs survey to identify the factors associated with accessing prison dental services in Scotland. Methods: A convenience sample of offenders from a male maximum security prison, a women’s prison, and a young offenders’ institution was gathered. A questionnaire examined the demography, prison experience, dental anxiety, oral health-related quality of life, and reported attendance of dental services. A dental examination was conducted using the International Caries Detection and Assessment System to diagnose obvious decay. A hierarchical logistic regression analysis was performed. Results: 342 prisoners participated. When missing data were excluded, the final sample was 259. The regression analysis showed the following: Model 1 characterized the offenders by demography and prison experience, explaining 19% of the variance. Model 2 showed that an offender was 36% more likely to attend dental services for every unit change in the 5-point ranking scale of ‘feeling irritable with people because of teeth, mouth, or dentures’, explaining an additional 7% of the variance. Model 3 explained 35% of the variance, (i.e., an additional 9%) and was adopted as the final model to characterize offenders who access dental services when in prison. An offender who reported accessing prison dental services was 3.28 times more likely to be male. For each increase in the year of an offender’s age, the offender was 5% more likely to access prison dental services. An 11% greater chance of accessing prison dental services for every experience of remand was also found. An offender was 32% more likely to access prison dental services for each increased level of irritability, and there was a 2 times higher likelihood of emergency dental services’ attendance. There was a 19% lower chance of accessing prison dental services for each additional tooth affected by decay and a 13% greater chance of accessing prison dental services for each unit increase in missing teeth. Conclusions: In conclusion, this investigation identified factors associated with access to prison dental services in Scotland. The role of accessibility factors, such as the oral health impact of irritability, appeared to increase perceptions of dental need and promote dental services’ attendance.
A Thermodynamic Constitutive Model for Saturated Sand
Authors: Xiao Shize , Cheng Xiaohui , Yang Zhou
Published: February 2019

This paper establishes a non-equilibrium thermodynamic constitutive model that can predict the undrained shear behavior of saturated sand. Starting from the basic laws of thermodynamics, the model does not require the classical concepts in elasto-plastic models, such as the yield function, the flow rule, and the hardening rule. It is also different from the existing thermodynamic constitutive models in soil mechanics literatures. The model does not use a complex nonlinear elastic potential as usually and introduces a coupling energy dissipative mechanism between the viscosity and elasticity relaxation, which is essential in granular materials. Then this model was used to simulate the undrained shear test of Toyoura sand. The model can predict the critical state, dilatancy-contraction and hardening-softening characteristics of sand during undrained triaxial shearing.
Panel Data Estimation for Correlated Random Coefficients Models
Authors: Hsiao Cheng , Li Qi , Liang Zhongwen , Xie Wei
Published: February 2019

This paper considers methods of estimating a static correlated random coefficient model with panel data. We mainly focus on comparing two approaches of estimating unconditional mean of the coefficients for the correlated random coefficients models, the group mean estimator and the generalized least squares estimator. For the group mean estimator, we show that it achieves Chamberlain (1992) semi-parametric efficiency bound asymptotically. For the generalized least squares estimator, we show that when T is large, a generalized least squares estimator that ignores the correlation between the individual coefficients and regressors is asymptotically equivalent to the group mean estimator. In addition, we give conditions where the standard within estimator of the mean of the coefficients is consistent. Moreover, with additional assumptions on the known correlation pattern, we derive the asymptotic properties of panel least squares estimators. Simulations are used to examine the finite sample performances of different estimators.
A Reverse Engineering Role-Play to Teach Systems Engineering Methods
Authors: Bertoni Alessandro
Published: February 2019

Students engaged in systems engineering education typically lack experience and understanding of the multidisciplinary complexity of systems engineering projects. Consequently, students struggle to understand the value, rationale, and usefulness of established systems engineering methods, often perceiving them as banal or trivial. The paper presents a learning activity based on a three-stage reverse engineering role-play developed to increase students’ awareness of the importance of correctly using systems engineering methods. The activity was developed and integrated in the Systems Engineering course given at Blekinge Institute of Technology. Its effectiveness was analyzed through semistructured self-reflection reports along with two editions of the course. The results showed the development of students’ understanding of how to use systems engineering methods. In particular, the students realized the need to deliver detailed and easy-to-read models to the decision makers. This result was in line with the achievement of some of the intended learning outcomes of the course.
Trajectory Protection Schemes Based on a Gravity Mobility Model in IoT
Authors: Wu Qiong , Liu Hanxu , Zhang Cui , Fan Qiang , Li Zhengquan , Wang Kan
Published: February 2019

With the proliferation of the Internet-of-Things (IoT), the users’ trajectory data containing privacy information in the IoT systems are easily exposed to the adversaries in continuous location-based services (LBSs) and trajectory publication. Existing trajectory protection schemes generate dummy trajectories without considering the user mobility pattern accurately. This would cause that the adversaries can easily exclude the dummy trajectories according to the obtained geographic feature information. In this paper, the continuous location entropy and the trajectory entropy are defined based on the gravity mobility model to measure the level of trajectory protection. Then, two trajectory protection schemes are proposed based on the defined entropy metrics to protect the trajectory data in continuous LBSs and trajectory publication, respectively. Experimental results demonstrate that the proposed schemes have a higher level than the enhanced dummy-location selection (enhance-DLS) scheme and the random scheme.
CMOS Interfaces for Internet-of-Wearables Electrochemical Sensors: Trends and Challenges
Authors: Dei Michele , Aymerich Joan , Piotto Massimo , Bruschi Paolo , del Campo Francisco Javier , Serra-Graells Francesc
Published: February 2019

Smart wearables, among immediate future IoT devices, are creating a huge and fast growing market that will encompass all of the next decade by merging the user with the Cloud in a easy and natural way. Biological fluids, such as sweat, tears, saliva and urine offer the possibility to access molecular-level dynamics of the body in a non-invasive way and in real time, disclosing a wide range of applications: from sports tracking to military enhancement, from healthcare to safety at work, from body hacking to augmented social interactions. The term Internet of Wearables (IoW) is coined here to describe IoT devices composed by flexible smart transducers conformed around the human body and able to communicate wirelessly. In addition the biochemical transducer, an IoW-ready sensor must include a paired electronic interface, which should implement specific stimulation/acquisition cycles while being extremely compact and drain power in the microwatts range. Development of an effective readout interface is a key element for the success of an IoW device and application. This review focuses on the latest efforts in the field of Complementary Metal–Oxide–Semiconductor (CMOS) interfaces for electrochemical sensors, and analyses them under the light of the challenges of the IoW: cost, portability, integrability and connectivity.
Nano-Particle VO2 Insulator-Metal Transition Field-Effect Switch with 42 mV/decade Sub-Threshold Slope
Authors: Tabib-Azar Massood , Likhite Rugved
Published: February 2019

The possibility of controlling the insulator-to-metal transition (IMT) in nano-particle VO2 (NP-VO2) using the electric field effect in a metal-oxide-VO2 field-effect transistor (MOVFET) at room temperature was investigated for the first time. The IMT induced by current in NP-VO2 is a function of nano-particle size and was studied first using the conducting atomic force microscope (cAFM) current-voltage (I-V) measurements. NP-VO2 switching threshold voltage (VT), leakage current (Ileakage), and the sub-threshold slope of their conductivity (Sc) were all determined. The cAFM data had a large scatter. However, VT increased as a function of particle height (h) approximately as VT(V) = 0.034 h, while Ileakage decreased as a function of h approximately as Ileakage (A) = 3.4 × 10−8e−h/9.1. Thus, an asymptotic leakage current of 34 nA at zero particle size and a tunneling (carrier) decay constant of ~9.1 nm were determined. Sc increased as a function of h approximately as Sc (mV/decade) = 2.1 × 10−3eh/6 and was around 0.6 mV/decade at h~34 nm. MOVFETs composed of Pt drain, source and gate electrodes, HfO2 gate oxide, and NP-VO2 channels were then fabricated and showed gate voltage dependent drain-source switching voltage and current (IDS). The subthreshold slope (St) of drain-source current (IDS) varied from 42 mV/decade at VG = −5 V to 54 mV/decade at VG = +5 V.
Compact UWB Band-Notched Antenna with Integrated Bluetooth for Personal Wireless Communication and UWB Applications
Authors: Rahman MuhibUr , NagshvarianJahromi Mahdi , Mirjavadi Seyed Sajad , Hamouda Abdel Magid
Published: February 2019

A compact band-notched UWB (Ultra-Wide Band) antenna with integrated Bluetooth is developed for personal wireless communication and UWB applications. The antenna operates at the UWB frequency band (3.1–10.6 GHz) as well as Bluetooth (2.4–2.484 GHz), with band-notch characteristics at the Wireless Local Area Network (WLAN) frequency band (5–6 GHz). A new technique of integrating Bluetooth within a UWB band-notched antenna is developed and analyzed. The UWB frequency band is realized by utilizing a conventional cylindrical radiating patch and a modified partial ground plane. The Bluetooth band is integrated using a miniaturized resonator with the addition of capacitors. Further, to mitigate the interference of the WLAN frequency band within the UWB spectrum, a conventional slot resonator is integrated within the radiator to achieve the task. The antenna is designed and fabricated, and its response in each case is provided. Moreover, the antenna exhibits a good radiation pattern with a stable gain in the passband. The present antenna is also compared to state-of-the-art structures proposed in the literature. The miniaturized dimensions (30 × 31 mm2) of the antenna make it an excellent candidate for UWB and personal wireless communication applications.
Optimization Algorithm for Multiple Phases Sectionalized Modulation Jamming Based on Particle Swarm Optimization
Authors: Jiang Jiawei , Wu Yanhong , Wang Hongyan , Lv Yakun , Qiu Lei , Yu Daobin
Published: February 2019

Due to the difficulty in deducing the corresponding relationship between results and parameter settings of multiple phases sectionalized modulation (MPSM) jamming, a problem occurs when obtaining the optimal local suppression jamming effect, which limits the practical application of MPSM jamming. The traditional method struggles to meet the requirements by setting fixed parameters or random parameters. Therefore, an optimization algorithm for MPSM jamming based on particle swarm optimization (PSO) is proposed in this study to produce the optimal local suppression jamming effect and determine its corresponding parameter settings. First, we analyzed the relationship between the degree of mismatch and local suppression jamming effect. Then, we set appropriate fitness function and fitness value. Finally, we used PSO to calculate parameter settings of a section situation and phase situation, which minimizes the fitness function and fitness value. The optimization algorithm avoids the tremendous computation of traversing all parameter settings, is stable, the results are repeatable, and the algorithm provides the optimal local suppression jamming effect under different conditions. The simulation experiments demonstrate the feasibility and effectiveness of the optimization algorithm.
Current State of Multicast Routing Protocols for Disruption Tolerant Networks: Survey and Open Issues
Authors: Wong Khang-Siang , Wan Tat-Chee
Published: February 2019

The deployment of Internet of Things (IoT) applications in remote areas, such as environmental sensing areas, requires Disruption Tolerant Networking (DTN) support due to the lack of continuous network connectivity. IoT devices in DTN generate and store data until a network link is available for data transmission. Data mules or ferries are scheduled to travel among intermittent networks to collect data and disseminate configuration updates from control centers to all participating nodes in a reliable manner. The incorporation of efficient, reliable multicast algorithms into DTN helps to overcome the current limitations in updating large numbers of nodes in remote areas with identical configurations. In this paper, the current state of multicast routing protocols in DTN is outlined according to their design aspects. Open issues are also discussed to provide impetus for further research into the Reliable Multicast DTN (RMDTN) protocol.
SSCFM: Separate Signature-Based Control Flow Error Monitoring for Multi-Threaded and Multi-Core Environments
Authors: Choi Kiho , Park Daejin , Cho Jeonghun
Published: February 2019

Soft error is a key challenge in computer systems. Without soft error mitigation, control flow error (CFE) can lead to system crash. Signature-based CFE monitoring scheme is a representative technique for detecting CFEs during runtime. However, most of the signature-based CFE monitoring schemes proposed thus far are based on a single thread. Currently, the widely used multi-threaded and multi-core environments have greatly improved the performance of the computing system, but, if the these schemes are applied in these environments, performance improvement is difficult to achieve, or rather performance degradation may occur. In this paper, we propose a separate signature-based CFE monitoring (SSCFM) scheme that separates the signature update and the signature verification on the thread level. The signature update is combined with application thread and signature verification and executed on separate monitor threads, so that we can expect performance improvements in multi-threaded or multi-core environments. Furthermore, the SSCFM scheme can fully cover inter-procedural CFE not covered by many signature-based CFE monitoring schemes by using inter-procedural control flow analysis. With the proposed SSCFM scheme, the execution time overhead is reduced by approximately 26.67% on average from the SEDSR scheme, and the average CFE detection rate with SSCFM is approximately 93.69%. In addition, this paper also introduces the LLVM compiler-based SSCFM generator that makes it easy to apply the SSCFM scheme to software applications.
A Review of Electric Impedance Matching Techniques for Piezoelectric Sensors, Actuators and Transducers
Authors: Rathod Vivek T.
Published: February 2019

Any electric transmission lines involving the transfer of power or electric signal requires the matching of electric parameters with the driver, source, cable, or the receiver electronics. Proceeding with the design of electric impedance matching circuit for piezoelectric sensors, actuators, and transducers require careful consideration of the frequencies of operation, transmitter or receiver impedance, power supply or driver impedance and the impedance of the receiver electronics. This paper reviews the techniques available for matching the electric impedance of piezoelectric sensors, actuators, and transducers with their accessories like amplifiers, cables, power supply, receiver electronics and power storage. The techniques related to the design of power supply, preamplifier, cable, matching circuits for electric impedance matching with sensors, actuators, and transducers have been presented. The paper begins with the common tools, models, and material properties used for the design of electric impedance matching. Common analytical and numerical methods used to develop electric impedance matching networks have been reviewed. The role and importance of electrical impedance matching on the overall performance of the transducer system have been emphasized throughout. The paper reviews the common methods and new methods reported for electrical impedance matching for specific applications. The paper concludes with special applications and future perspectives considering the recent advancements in materials and electronics.
Environmental and Operational Performance of CO2-EOR as a CCUS Technology: A Cranfield Example with Dynamic LCA Considerations
Authors: Núñez-López Vanessa , Gil-Egui Ramón , Hosseini Seyyed A.
Published: February 2019

This study evaluates the potential of carbon dioxide-enhanced oil recovery (CO2-EOR) to reduce greenhouse gas emissions without compromising oil production goals. A novel, dynamic carbon lifecycle analysis (d-LCA) was developed and used to understand the evolution of the environmental impact (CO2 emissions) and mitigation (geologic CO2 storage) associated with an expanded carbon capture, utilization and storage (CCUS) system, from start to closure of operations. EOR operational performance was assessed through CO2 utilization rates, which relate usage of CO2 to oil production. Because field operational strategies have a significant impact on reservoir engineering parameters that affect both CO2 storage and oil production (e.g., sweep efficiency, flood conformance, fluid saturation distribution), we conducted a scenario analysis that assessed the operational and environmental performance of four common and novel CO2-EOR field development strategies. Each scenario was evaluated with and without stacked saline carbon storage, an EOR/storage combination strategy where excess CO2 from the recycling facility is injected into an underlying saline aquifer for long-term carbon storage. The dynamic interplay between operational and environmental performance formed the basis of our CCUS technology analysis. The results showed that all CO2-EOR evaluated scenarios start operating with a negative carbon footprint and, years into the project, transitioned into operating with a positive carbon footprint. The transition points were significantly different in each scenario. Water-alternating-gas (WAG) was identified as the CO2 injection strategy with the highest potential to co-optimize EOR and carbon storage goals. The results provide an understanding of the evolution of the system’s net carbon balance in all four field development strategies studied. The environmental performance can be significantly improved with stacked storage, where a negative carbon footprint can be maintained throughout the life of the operation in most of the injection scenarios modelled. This information will be useful to CO2-EOR operators seeking value in storing more CO2 through a carbon credit program (e.g., the 45Q carbon credit program in the USA). Most importantly, this study serves as confirmation that CO2-EOR can be operationally designed to both enhance oil production and reduce greenhouse gas emissions into the atmosphere.