bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic resonance–guided interstitial high-intensity focused ultrasound for brain tumor ablation
Authors: MacDonell Jacquelyn , Patel Niravkumar , Rubino Sebastian , Ghoshal Goutam , Fischer Gregory , Burdette E. Clif , Hwang Roy , Pilitsis Julie G.
Published: February 2018

Currently, treatment of brain tumors is limited to resection, chemotherapy, and radiotherapy. Thermal ablation has been recently explored. High-intensity focused ultrasound (HIFU) is being explored as an alternative. Specifically, the authors propose delivering HIFU internally to the tumor with an MRI-guided robotic assistant (MRgRA). The advantage of the authors’ interstitial device over external MRI-guided HIFU (MRgHIFU) is that it allows for conformal, precise ablation and concurrent tissue sampling. The authors describe their workflow for MRgRA HIFU delivery.
Preliminary experience with a transcranial magnetic resonance–guided focused ultrasound surgery system integrated with a 1.5-T MRI unit in a series of patients with essential tremor and Parkinson’s disease
Authors: Iacopino Domenico Gerardo , Gagliardo Cesare , Giugno Antonella , Giammalva Giuseppe Roberto , Napoli Alessandro , Maugeri Rosario , Graziano Francesca , Valentino Francesca , Cosentino Giuseppe , D’Amelio Marco , Bartolotta Tommaso Vincenzo , Catalano Carlo , Fierro Brigida , Midiri Massimo , Lagalla Roberto
Published: February 2018

OBJECTIVE

Transcranial magnetic resonance–guided focused ultrasound surgery (tcMRgFUS) is one of the emerging noninvasive technologies for the treatment of neurological disorders such as essential tremor (ET), idiopathic asymmetrical tremor-dominant Parkinson’s disease (PD), and neuropathic pain. In this clinical series the authors present the preliminary results achieved with the world’s first tcMRgFUS system integrated with a 1.5-T MRI unit.

METHODS

The authors describe the results of tcMRgFUS in a sample of patients with ET and with PD who underwent the procedure during the period from January 2015 to September 2017. A monolateral ventralis intermedius nucleus (VIM) thalamic ablation was performed in both ET and PD patients. In all the tcMRgFUS treatments, a 1.5-T MRI scanner was used for both planning and monitoring the procedure.

RESULTS

During the study period, a total of 26 patients underwent tcMRgFUS thalamic ablation for different movement disorders. Among these patients, 18 were diagnosed with ET and 4 were affected by PD. All patients with PD were treated using tcMRgFUS thalamic ablation and all completed the procedure. Among the 18 patients with ET, 13 successfully underwent tcMRgFUS, 4 aborted the procedure during ultrasound delivery, and 1 did not undergo the tcMRgFUS procedure after stereotactic frame placement. Two patients with ET were not included in the results because of the short follow-up duration at the time of this study. A monolateral VIM thalamic ablation in both ET and PD patients was performed. All the enrolled patients were evaluated before the treatment and 2 days after, with a clinical control of the treatment effectiveness using the graphic items of the Fahn-Tolosa-Marin tremor rating scale. A global reevaluation was performed 3 months (17/22 patients) and 6 months (11/22 patients) after the treatment; the reevaluation consisted of clinical questionnaires, neurological tests, and video recordings of the tests. All the ET and PD treated patients who completed the procedure showed an immediate amelioration of tremor severity, with no intra- or posttreatment severe permanent side effects.

CONCLUSIONS

Although this study reports on a small number of patients with a short follow-up duration, the tcMRgFUS procedure using a 1.5-T MRI unit resulted in a safe and effective treatment option for motor symptoms in patients with ET and PD. To the best of the authors’ knowledge, this is the first clinical series in which thalamotomy was performed using tcMRgFUS integrated with a 1.5-T magnet.
Focused ultrasound–mediated noninvasive blood-brain barrier modulation: preclinical examination of efficacy and safety in various sonication parameters
Authors: Shin Jaewoo , Kong Chanho , Cho Jae Sung , Lee Jihyeon , Koh Chin Su , Yoon Min-Sik , Na Young Cheol , Chang Won Seok , Chang Jin Woo
Published: February 2018

OBJECTIVE

The application of pharmacological therapeutics in neurological disorders is limited by the ability of these agents to penetrate the blood-brain barrier (BBB). Focused ultrasound (FUS) has recently gained attention for its potential application as a method for locally opening the BBB and thereby facilitating drug delivery into the brain parenchyma. However, this method still requires optimization to maximize its safety and efficacy for clinical use. In the present study, the authors examined several sonication parameters of FUS influencing BBB opening in small animals.

METHODS

Changes in BBB permeability were observed during transcranial sonication using low-intensity FUS in 20 adult male Sprague-Dawley rats. The authors examined the effects of FUS sonication with different sonication parameters, varying acoustic pressure, center frequency, burst duration, microbubble (MB) type, MB dose, pulse repetition frequency (PRF), and total exposure time. The focal region of BBB opening was identified by Evans blue dye. Additionally, H & E staining was used to identify blood vessel damage.

RESULTS

Acoustic pressure amplitude and burst duration were closely associated with enhancement of BBB opening efficiency, but these parameters were also highly correlated with tissue damage in the sonicated region. In contrast, MB types, MB dose, total exposure time, and PRF had an influence on BBB opening without conspicuous tissue damage after FUS sonication.

CONCLUSIONS

The study aimed to identify these influential conditions and provide safety and efficacy values for further studies. Future work based on the current results is anticipated to facilitate the implementation of FUS sonication for drug delivery in various CNS disease states in the near future.
Desmopressin administration and rebleeding in subarachnoid hemorrhage: analysis of an observational prospective database
Authors: Francoeur Charles L. , Roh David , Schmidt J. Michael , Mayer Stephan A. , Falo M. Cristina , Agarwal Sachin , Connolly E. Sander , Claassen Jan , Elkind Mitchell S. V. , Park Soojin
Published: February 2018

OBJECTIVE

Rebleeding remains a frequent and catastrophic event leading to poor outcome after subarachnoid hemorrhage (SAH). Reduced platelet function after the initial bleed is associated with higher risk of early rebleeding. Desmopressin (DDAVP) is a well-known hemostatic agent, and recent guidelines already suggest its use in individuals exposed to antiplatelet drugs. The authors hypothesized that DDAVP administration in patients with SAH at admission would be associated with lower risks of rebleeding.

METHODS

The authors performed an observational cohort study of patients enrolled in the Columbia University SAH Outcome Project between August 1996 and July 2015. The authors compared the rate of rebleeding between patients who were and those who were not treated with DDAVP. After adjustment for known predictors, logistic regression was used to measure the association between treatment with DDAVP and risks of rebleeding.

RESULTS

Among 1639 patients with SAH, 12% were treated with DDAVP. The main indication for treatment was suspected exposure to an antiplatelet agent. The overall incidence of rebleeding was 9% (1% among patients treated with DDAVP compared with 8% among those not treated). After adjustment for antiplatelet use and known predictors, treatment with DDAVP was associated with a 45% reduction in the risks of rebleeding (adjusted OR 0.55, 95% CI 0.27–0.97). DDAVP was associated with a higher incidence of hyponatremia but not with thrombotic events or delayed cerebral ischemia.

CONCLUSIONS

Treatment with DDAVP was associated with a lower risk of rebleeding among patients with SAH. These findings support further study of DDAVP as first-line therapy for medical hemostasis in patients with SAH.
A historical recount of chordoma
Authors: Sahyouni Ronald , Goshtasbi Khodayar , Mahmoodi Amin , Chen Jefferson W.
Published: February 2018

Chordoma, a rare bone tumor that occurs along the spine, has led scientists on a fascinating journey of discoveries. In this historical vignette, the authors track these discoveries in diagnosis and treatment, noting events and clinicians that played pivotal roles in our current understanding of chordoma. The study of chordoma begins in 1846 when Rudolf Virchow first observed its occurrence on a dorsum sellae; he coined the term “chordomata” 11 years later. The chordoma’s origin was greatly disputed by members of the scientific community. Eventually, Müller’s notochord hypothesis was accepted 36 years after its proposal. Chordomas were considered benign and slow growing until the early 1900s, when reported autopsy cases drew attention to their possible malignant nature. Between 1864 and 1919, the first-ever symptomatic descriptions of various forms of chordoma were reported, with the subsequent characterization of chordoma histology and the establishment of classification criteria shortly thereafter. The authors discuss the critical historical steps in diagnosis and treatment, as well as pioneering operations and treatment modalities, noting the physicians and cases responsible for advancing our understanding of chordoma.
The effect of strawberry cultivars, infested with Tetranychus urticae (Acari: Tetranychidae), on the olfactory response of the predatory mite Neoseiulus californicus (Acari: Phytoseiidae)
Authors: Rezaie Maryam , Saboori Alireza , Baniameri Valiollah
Published: February 2018

Tetranychus urticae Koch (Acari: Tetranychidae) is a key pest of agricultural crop. One of the best candidates for biological control of this mite is Neoseiulus californicus (McGregor) (Acari: Phytoseiidae). In this study, the olfactory response of the predatory mite to seven strawberry cultivars (‘Marak’, ‘Yalova’, ‘Aliso’, ‘Gaviota’, ‘Sequoia’, ‘Camarosa’ and ‘Chandler’) was studied using a Y-tube olfactometer. We used two-day-old female predatory mites that were reared on spider mite-infested strawberry. The behavioral response of the predator was studied in four experiments: 1) clean air vs. uninfected strawberry plant, 2) clean air vs. spider mite-infested strawberry plant, 3) uninfected strawberry plant vs. spider mite-infested strawberry plant and 4) two-cultivar choice test (spider mite-infested). In the first experiment, the attraction of the predatory mite to uninfected strawberry plant volatiles was significant. In the second test, the predators significantly preferred volatiles from strawberry plant infested with T. urticae to clean air. In the third test, 68% to 80% of the predatory mites were attracted to spider mite-infested strawberry plant volatiles compared with uninfected plants. Among the seven strawberry cultivars, the predator responses to volatiles of infested plants varied 62% to 83% and to volatiles of uninfested plant varied 59% to 75%. Herbivore – induced plant volatile emitted from strawberry infested with T. urticae attract the predatory mite. The last test showed that ‘Aliso’ and ‘Chandler’ were more attractive for the predatory mite.
The Road Map to Brave New World: Cartography and Fordism from Gulf Oil to Google
Authors: Ström Timothy Erik
Published: February 2018

This paper explores the shifting practices in and between cartography and capitalism. It compares two road maps of the same territory created one-hundred years apart; a Gulf Oil map from 1915 and a Google Map from 2015. These representations of space serve as entry points into examining some of the larger transformations that have occurred within capitalism over the century. I am interested in how the classic world order of Fordism has been reconstituted by cybernetic capitalism. I argue that the world order has been intensified and reorganised on a more abstract level, with profound subjective and material consequences.
On Being Here
Authors: Karlsson Mattis
Published: February 2018

This paper is a response to the social anthropologist’s frustration of not being there. It is, to make further use of your own words, an attempt to deal with my own chronic disciplinary identity crisis. It is a response written in recognition of your situation and in recognition of the symptoms that you so eloquently describe.
Black Hawk-Down: Adaptation and the Military-Entertainment Complex
Authors: Höglund Johan , Willander Martin
Published: February 2018

This article investigates the non-fiction book Black Hawk Down (1999) by Mark Bowden, Black Hawk Down the movie (2001) directed by Ridley Scott, and the computer game Delta Force: Black Hawk Down (2003). The article suggests that while the movie and the game must be studied as adaptations of the first text, the tools developed by adaptation studies, and that are typically used to study the transfer of narratives from one media form to another, do not suffice to fully describe the ways in which these narratives change between iterations. To provide a more complete account of these adaptations, the article therefore also considers the shifting political climate of the 9/11 era, the expectations from different audiences and industries, and, in particular, the role that what James Der Derian has termed the Military-Industrial-Media-Entertainment Network (MIME-Net) plays in the production of narrative. The article thus investigates how a specific political climate and MIME-Net help to produce certain adaptations. Based on this investigation, the article argues that MIME-Net plays a very important role in the adaptation of the Black Hawk Down story by directing attention away from historical specificity and nuance, towards the spectacle of war. Thus, in Black Hawk Down the movie and in Delta Force: Black Hawk Down, authenticity is understood as residing in the spectacular rendering of carnage rather than in historical facts. The article concludes that scholarly investigations of the adaptation of military narratives should combine traditional adaptation studies tools with theory and method that highlight the role that politics and complexes such as MIME-Net play within the culture industry.
What Prompts Agricultural Innovation in Rural Nepal: A Study Using the Example of Macadamia and Walnut Trees as Novel Cash Crops
Authors: Barrueto Andrea , Merz Juerg , Kohler Thomas , Hammer Thomas
Published: February 2018

Agricultural innovations are important, especially as climatic conditions around the world have been subject to increasing change over the past decades. Through innovation, farmers can adapt to the changing conditions and secure their livelihoods. In Nepal, 75% of the population depends upon agriculture, which is impacted by climate change, migration, and feminisation. In this context, it is important to understand what drives a household to start agricultural innovation to increase its economic benefits and resilience in the face of multiple pressures. We sought a comprehensive understanding of these drivers by investigating the determinants of rural innovation, using macadamia and walnut trees as examples of novel, potentially commercialised cash crops. After conducting an in-depth household survey that divided farmers into those who cultivate nuts and those who do not, we analysed the socio-economic and cultural characteristics of each category using statistical tests and a multiple logistic regression. Our results show that the individual variables of ethnicity, wealth and “years of experience with fruit trees” correlate significantly with nut cultivation. The results of the multiple regression suggest that “years of experience with tree cultivation” and “having an income through fruit trees” most influence nut cultivation. Overall, we conclude that nut cultivation is an accepted and promising cash crop mostly grown by wealthier households, and that, for poor, landless, or female-headed households to benefit, alternative business models and new policies must be explored and developed. We further suggest that this is also true for other nut or other cash crop trees that have gained recent attention in Nepal such as almond, hazelnut, or pecan farming.
Kernel-Density-Based Particle Defect Management for Semiconductor Manufacturing Facilities
Authors: Park Seung , Kim Sehoon , Baek Jun-Geol
Published: February 2018

In a semiconductor manufacturing process, defect cause analysis is a challenging task because the process includes consecutive fabrication phases involving numerous facilities. Recently, in accordance with the shrinking chip pitches, fabrication (FAB) processes require advanced facilities and designs for manufacturing microcircuits. However, the sizes of the particle defects remain constant, in spite of the increasing modernization of the facilities. Consequently, this increases the particle defect ratio. Therefore, this study proposes a particle defect management method for the reduction of the defect ratio. The proposed method provides a kernel-density-based particle map that can overcome the limitations of the conventional method. The method consists of two phases. The first phase is the acquisition of cumulative coordinates of the defect locations on the wafer using the FAB database. Subsequently, this cumulative data is used to generate a particle defect map based on the estimation of kernel density; this map establishes the advanced monitoring statistics. In order to validate this method, we conduct an experiment for comparison with the previous industrial method.
A Parallel Approach for Frequent Subgraph Mining in a Single Large Graph Using Spark
Authors: Qiao Fengcai , Zhang Xin , Li Pei , Ding Zhaoyun , Jia Shanshan , Wang Hui
Published: February 2018

Frequent subgraph mining (FSM) plays an important role in graph mining, attracting a great deal of attention in many areas, such as bioinformatics, web data mining and social networks. In this paper, we propose SSiGraM (Spark based Single Graph Mining), a Spark based parallel frequent subgraph mining algorithm in a single large graph. Aiming to approach the two computational challenges of FSM, we conduct the subgraph extension and support evaluation parallel across all the distributed cluster worker nodes. In addition, we also employ a heuristic search strategy and three novel optimizations: load balancing, pre-search pruning and top-down pruning in the support evaluation process, which significantly improve the performance. Extensive experiments with four different real-world datasets demonstrate that the proposed algorithm outperforms the existing GraMi (Graph Mining) algorithm by an order of magnitude for all datasets and can work with a lower support threshold.
Tyrosine Hydroxylase, Vesicular Monoamine Transporter and Dopamine Transporter mRNA Expression in Nigrostriatal Tissue of Rats with Pedunculopontine Neurotoxic Lesion
Authors: Blanco-Lezcano Lisette , Alberti-Amador Esteban , Díaz-Hung Mei-Li , González-Fraguela María , Estupiñán-Díaz Bárbara , Serrano-Sánchez Teresa , Francis-Turner Liliana , Jiménez-Martín Javier , Vega-Hurtado Yamilé , Fernández-Jiménez Isabel
Published: February 2018

Background: The degeneration of the pedunculopontine nucleus (PPN) precedes the degeneration of the nigral cells in the pre-symptomatic stages of Parkinson’s disease (PD). Although the literature recognizes that a lesion of the PPN increases the vulnerability of dopaminergic cells, it is unknown if this risk is associated with the loss of capability of handling the dopaminergic function. Methods: In this paper, the effects of a unilateral neurotoxic lesion of the PPN in tyrosine hydroxylase (TH), vesicular monoamine transporter 2 (VMAT2) and dopamine transporter (DAT) mRNA expression in nigrostriatal tissue were evaluated. Three experimental groups were organized: non-treated rats, NMDA-lesioned rats and Sham-operated rats. Results: Seven days after the PPN lesion, in nigral tissue, TH mRNA expression was higher in comparison with control groups (p < 0.05); in contrast, VMAT2 mRNA expression showed a significant decrease (p < 0.01). DAT mRNA expression showed a significant decrease (p < 0.001) in the striatal tissue. Comparing nigral neuronal density of injured and control rats revealed no significant difference seven days post-PPN injury. Conclusions: Findings suggest that the PPN lesion modifies the mRNA expression of the proteins associated with dopaminergic homeostasis at nigrostriatal level. It could represent vulnerability signals for nigral dopaminergic cells and further increase the risk of degeneration of these cells.
Holonomic Constraints: A Case for Statistical Mechanics of Non-Hamiltonian Systems
Authors: Ciccotti Giovanni , Ferrario Mauro
Published: February 2018

A dynamical system submitted to holonomic constraints is Hamiltonian only if considered in the reduced phase space of its generalized coordinates and momenta, which need to be defined ad hoc in each particular case. However, specially in molecular simulations, where the number of degrees of freedom is exceedingly high, the representation in generalized coordinates is completely unsuitable, although conceptually unavoidable, to provide a rigorous description of its evolution and statistical properties. In this paper, we first review the state of the art of the numerical approach that defines the way to conserve exactly the constraint conditions (by an algorithm universally known as SHAKE) and permits integrating the equations of motion directly in the phase space of the natural Cartesian coordinates and momenta of the system. We then discuss in detail SHAKE numerical implementations in the notable cases of Verlet and velocity-Verlet algorithms. After discussing in the same framework how constraints modify the properties of the equilibrium ensemble, we show how, at the price of moving to a dynamical system no more (directly) Hamiltonian, it is possible to provide a direct interpretation of the dynamical system and so derive its Statistical Mechanics both at equilibrium and in non-equilibrium conditions. To achieve that, we generalize the statistical treatment to systems no longer conserving the phase space volume (equivalently, we introduce a non-Euclidean invariant measure in phase space) and derive a generalized Liouville equation describing the ensemble even out of equilibrium. As a result, we can extend the response theory of Kubo (linear and nonlinear) to systems subjected to constraints.
Effects of Symmetry Breaking in Resonance Phenomena
Authors: Yukalov Vyacheslav , Yukalova Elizaveta
Published: February 2018

We show that resonance phenomena can be treated as nonequilibrium phase transitions. Resonance phenomena, similar to equilibrium phase transitions, are accompanied by some kind of symmetry breaking and can be characterized by order parameters. This is demonstrated for spin-wave resonance, helicon resonance, and spin-reversal resonance.
Solvent-Free Synthesis of All Silica Beta Zeolite in the Presence of Tetraethylammonium Bromide
Authors: Cui Yucun , Yan Zheng , Li Mengli , Zhu Jie , Zhu Longfeng , Yao Hong , Cao Xuebo
Published: February 2018

We report a solvent-free synthesis of all silica Beta zeolite using a cheap organic template of tetraethylammonium bromide (TEABr). The method includes mixing, grinding and heating solid raw material in the absence of water solvent but the presence of zeolite seeds. The absence of water solvent significantly improves the efficiency of synthesis, while the addition of seeds remarkably enhances the crystallization rate. In addition, the use of a cheap organic template of TEABr greatly decreases the synthesis cost. The effects of the reaction compositions, including the molar ratios of NH4F/SiO2, TEABr/SiO2, and mass ratios of seeds to the silica, on the synthesis of the pure product were investigated using different temperature. Physicochemical characterizations, including XRD, SEM, TG and N2 sorption, show that the zeolitic product has good crystallinity, uniform crystals, and high surface area.
Lattice Vibration of Layered GaTe Single Crystals
Authors: Wang Tao , Zhao Qinghua , Miao Yaping , Ma Fei , Xie Yong , Jie Wanqi
Published: February 2018

The effect of interlayer interaction on in-layer structure of laminar GaTe crystals was studied according to the lattice vibration using micro-Raman analysis. The results were also confirmed by the first principle calculations. Accordingly, the relationship between lattice vibration and crystal structure was established. Ten peaks were observed in the micro-Raman spectra from 100 cm−1 to 300 cm−1. Eight of them fit Raman-active vibration modes and the corresponding displacement vectors were calculated, which proved that the two modes situated at 128.7 cm−1 and 145.7 cm−1 were related to the lattice vibration of GaTe, instead of impurities or defects. Davydov splitting in GaTe was identified and confirmed by the existence of the other two modes, conjugate modes, at 110.7 cm−1 (∆ω = 33.1 cm−1) and 172.5 cm−1 (∆ω = 49.5 cm−1), indicates that the weak interlayer coupling has a significant effect on lattice vibrations in the two-layer monoclinic unit cell. Our results further proved the existence of two layers in each GaTe unit cell.
Tetra-, Penta- and Hexa-Coordinated Transition Metal Complexes Constructed from Coumarin-Containing N2O2 Ligand
Authors: Gao Lei , Liu Chang , Wang Fei , Dong Wen-Kui
Published: February 2018

Three newly designed complexes, [Cu(L)]·CHCl3 (1), [Co(L)(MeOH)]·CHCl3 (2) and [{Ni(L)(MeOH)(PhCOO)}2Ni] (3) a coumarin-containing Salamo-type chelating ligand (H2L) have been synthesized and characterized by elemental analyses, IR and UV-VIS spectra, and X-ray crystallography. Complex 1 includes one Cu(II) atom, one completely deprotonated (L)2− unit and one crystalling chloroform molecule, the Cu(II) atom shows a square-planar geometry. Complex 2 includes one Co(II) atom, one completely deprotonated (L)2− unit, one coordinated methanol molecule and one crystalling chloroform molecule. The Co(II) atom is a distorted trigonal-bipyramidal geometry. While complex 3 includes three Ni(II) atoms, two completely deprotonated (L)2− units, two benzoates and two coordinated methanol molecules. The complexes 1 and 2 are both possess three-dimensional supra-molecular structures by abundant noncovalent interactions. But, complex 3 formed a two-dimensional supra-molecular structure by intra-molecular hydrogen bonds. In addition, the antimicrobial and fluorescence properties of H2L and its complexes 1, 2 and 3 were also investigated.
Unravelling the High-Pressure Behaviour of Dye-Zeolite L Hybrid Materials
Authors: Gigli Lara , Arletti Rossella , Fois Ettore , Tabacchi Gloria , Quartieri Simona , Dmitriev Vladimir , Vezzalini Giovanna
Published: February 2018

Self-assembly of chromophores nanoconfined in porous materials such as zeolite L has led to technologically relevant host-guest systems exploited in solar energy harvesting, photonics, nanodiagnostics and information technology. The response of these hybrid materials to compression, which would be crucial to enhance their application range, has never been explored to date. By a joint high-pressure in situ synchrotron X-ray powder diffraction and ab initio molecular dynamics approach, herein we unravel the high-pressure behaviour of hybrid composites of zeolite L with fluorenone dye. High-pressure experiments were performed up to 6 GPa using non-penetrating pressure transmitting media to study the effect of dye loading on the structural properties of the materials under compression. Computational modelling provided molecular-level insight on the response to compression of the confined dye assemblies, evidencing a pressure-induced strengthening of the interaction between the fluorenone carbonyl group and zeolite L potassium cations. Our results reveal an impressive stability of the fluorenone-zeolite L composites at GPa pressures. The remarkable resilience of the supramolecular organization of dye molecules hyperconfined in zeolite L channels may open the way to the realization of optical devices able to maintain their functionality under extreme conditions.
A New ZVS Tuning Method for Double-Sided LCC Compensated Wireless Power Transfer System
Authors: Lu Sizhao , Deng Xiaoting , Shu Wenbin , Wei Xiaochao , Li Siqi
Published: February 2018

This paper presents a new zero voltage switching (ZVS) tuning method for the double-sided inductor/capacitor/capacitor (LCC) compensated wireless power transfer (WPT) system. An additional capacitor is added in the secondary side of the double-sided LCC compensation network in order to tune the network to realize ZVS operation for the primary-side switches. With the proposed tuning method, the turn off current of the primary-side switches at the low input voltage range can be reduced compared with the previous ZVS tuning method. Consequently, the efficiency of the WPT at the low input voltage range is improved. Moreover, the relationship between the input voltage and the output power is more linear than that of the previous ZVS tuning method. In addition, the proposed method has a lower start-up voltage. The analysis and validity of the proposed tuning method are verified by simulation and experimental results. A WPT system with up to 3.5 kW output power is built, and 95.9% overall peak efficiency is achieved.
Natural Fractures Characterization and In Situ Stresses Inference in a Carbonate Reservoir—An Integrated Approach
Authors: Shafiei Ali , B. Dusseault Maurice , Kosari Ehsan , N. Taleghani Morteza
Published: February 2018

In this paper, we characterized the natural fracture systems and inferred the state of in situ stress field through an integrated study in a very complex and heterogeneous fractured carbonate reservoir. Relative magnitudes and orientations of the in-situ principal stresses in a naturally fractured carbonate heavy oil field were estimated with a combination of available data (World Stress Map, geological and geotectonic evidence, outcrop studies) and techniques (core analysis, borehole image logs and Side View Seismic Location). The estimates made here using various tools and data including routine core analysis and image logs are confirmatory to estimates made by the World Stress Map and geotectonic facts. NE-SW and NW-SE found to be the dominant orientations for maximum and minimum horizontal stresses in the study area. In addition, three dominant orientations were identified for vertical and sub-vertical fractures atop the crestal region of the anticlinal structure. Image logs found useful in recognition and delineation of natural fractures. The results implemented in a real field development and proved practical in optimal well placement, drilling and production practices. Such integrated studies can be instrumental in any E&P projects and related projects such as geological CO2 sequestration site characterization.
Two-Stage Battery Energy Storage System (BESS) in AC Microgrids with Balanced State-of-Charge and Guaranteed Small-Signal Stability
Authors: Xie Bing , Liu Yiqi , Ji Yanchao , Wang Jianze
Published: February 2018

In this paper, a two-stage battery energy storage system (BESS) is implemented to enhance the operation condition of conventional battery storage systems in a microgrid. Particularly, the designed BESS is composed of two stages, i.e., Stage I: integration of dispersed energy storage units (ESUs) using parallel DC/DC converters, and Stage II: aggregated ESUs in grid-connected operation. Different from a conventional BESS consisting of a battery management system (BMS) and power conditioning system (PCS), the developed two-stage architecture enables additional operation and control flexibility in balancing the state-of-charge (SoC) of each ESU and ensures the guaranteed small-signal stability, especially in extremely weak grid conditions. The above benefits are achieved by separating the control functions between the two stages. In Stage I, a localized power sharing scheme based on the SoC of each particular ESU is developed to manage the SoC and avoid over-charge or over-discharge issues; on the other hand, in Stage II, an additional virtual impedance loop is implemented in the grid-interactive DC/AC inverters to enhance the stability margin with multiple parallel-connected inverters integrating at the point of common coupling (PCC) simultaneously. A simulation model based on MATLAB/Simulink is established, and simulation results verify the effectiveness of the proposed BESS architecture and the corresponding control diagram.
A Study of Nonlinear Elasticity Effects on Permeability of Stress Sensitive Shale Rocks Using an Improved Coupled Flow and Geomechanics Model: A Case Study of the Longmaxi Shale in China
Authors: Wei Chenji , Wang Liangang , Li Baozhu , Xiong Lihui , Liu Shuangshuang , Zheng Jie , Hu Suming , Song Hongqing
Published: February 2018

Gas transport in shale gas reservoirs is largely affected by rock properties such as permeability. These properties are often sensitive to the in-situ stress state changes. Accurate modeling of shale gas transport in shale reservoir rocks considering the stress sensitive effects on rock petrophysical properties is important for successful shale gas extraction. Nonlinear elasticity in stress sensitive reservoir rocks depicts the nonlinear stress-strain relationship, yet it is not thoroughly studied in previous reservoir modeling works. In this study, an improved coupled flow and geomechanics model that considers nonlinear elasticity is proposed. The model is based on finite element methods, and the nonlinear elasticity in the model is validated with experimental data on shale samples selected from the Longmaxi Formation in Sichuan Basin China. Numerical results indicate that, in stress sensitive shale rocks, nonlinear elasticity affects shale permeability, shale porosity, and distributions of effective stress and pore pressure. Elastic modulus change is dependent on not only in-situ stress state but also stress history path. Without considering nonlinear elasticity, the modeling of shale rock permeability in Longmaxi Formation can overestimate permeability values by 1.6 to 53 times.
Multifunctional Composites for Future Energy Storage in Aerospace Structures
Authors: Adam Till , Liao Guangyue , Petersen Jan , Geier Sebastian , Finke Benedikt , Wierach Peter , Kwade Arno , Wiedemann Martin
Published: February 2018

Multifunctionalization of fiber-reinforced composites, especially by adding energy storage capabilities, is a promising approach to realize lightweight structural energy storages for future transport vehicles. Compared to conventional energy storage systems, energy density can be increased by reducing parasitic masses of non-energy-storing components and by benefitting from the composite meso- and microarchitectures. In this paper, the most relevant existing approaches towards multifunctional energy storages are reviewed and subdivided into five groups by distinguishing their degree of integration and their scale of multifunctionalization. By introducing a modified range equation for battery-powered electric aircrafts, possible range extensions enabled by multifunctionalization are estimated. Furthermore, general and aerospace specific potentials of multifunctional energy storages are discussed. Representing an intermediate degree of structural integration, experimental results for a multifunctional energy-storing glass fiber-reinforced composite based on the ceramic electrolyte Li1.4Al0.4Ti1.6(PO4)3 are presented. Cyclic voltammetry tests are used to characterize the double-layer behavior combined with galvanostatic charge–discharge measurements for capacitance calculation. The capacitance is observed to be unchanged after 1500 charge–discharge cycles revealing a promising potential for future applications. Furthermore, the mechanical properties are assessed by means of four-point bending and tensile tests. Additionally, the influence of mechanical loads on the electrical properties is also investigated, demonstrating the storage stability of the composites.
Electro-Fermentation in Aid of Bioenergy and Biopolymers
Authors: Kumar Prasun , Chandrasekhar Kuppam , Kumari Archana , Sathiyamoorthi Ezhaveni , Kim Beom
Published: February 2018

The soaring levels of industrialization and rapid progress towards urbanization across the world have elevated the demand for energy besides generating a massive amount of waste. The latter is responsible for poisoning the ecosystem in an exponential manner, owing to the hazardous and toxic chemicals released by them. In the past few decades, there has been a paradigm shift from “waste to wealth”, keeping the value of high organic content available in the wastes of biological origin. The most practiced processes are that of anaerobic digestion, leading to the production of methane. However; such bioconversion has limited net energy yields. Industrial fermentation targeting value-added bioproducts such as—H2, butanediols; polyhydroxyalkanoates, citric acid, vitamins, enzymes, etc. from biowastes/lignocellulosic substrates have been planned to flourish in a multi-step process or as a “Biorefinery”. Electro-fermentation (EF) is one such technology that has attracted much interest due to its ability to boost the microbial metabolism through extracellular electron transfer during fermentation. It has been studied on various acetogens and methanogens, where the enhancement in the biogas yield reached up to 2-fold. EF holds the potential to be used with complex organic materials, leading to the biosynthesis of value-added products at an industrial scale.
Challenges and Opportunities of Very Light High-Performance Electric Drives for Aviation
Authors: Henke Markus , Narjes Gerrit , Hoffmann Jan , Wohlers Constantin , Urbanek Stefan , Heister Christian , Steinbrink Jörn , Canders Wolf-Rüdiger , Ponick Bernd
Published: February 2018

The demand for alternative fueling methods to reduce the need for fossil fuels is not limited to the electrification of ground vehicles. More-electric and all-electric aircraft pose challenges, with extensive requirements in terms of power density, efficiency, safety, and environmental sustainability. This paper focuses on electrical machines and their components, especially for high-power applications like the main propulsion. The electrical machine is evaluated from different aspects, followed by a closer look at the components and materials to determine the suitability of the current standard materials and advanced technologies. Furthermore, the mechanical and thermal aspects are reviewed, including new and innovative concepts for the cooling of windings and for the use of additive manufacturing. Aircraft have special demands regarding weight and installation space. Following recent developments and looking ahead to the future, the need and the possibilities for light and efficient electrical machines are addressed. All of the approaches and developments presented lead to a better understanding of the challenges to be expected and highlight the upcoming opportunities in electrical machine design for the use of electric motors and generators in future aircraft. Several prototypes of electrical machines for smaller aircraft already exist, such as the electric drive of the Siemens powered Extra 330LE. The focus of this paper is to provide an overview of current technical possibilities and technical interrelations of high performance electric drives for aviation. A 1 MW drive is exemplified to present the possibilities for future drives for airplanes carrying a larger number of passengers. All presented techniques can also be applied to other drive power classes.
Co-Planning of Demand Response and Distributed Generators in an Active Distribution Network
Authors: Yu Yi , Wen Xishan , Zhao Jian , Xu Zhao , Li Jiayong
Published: February 2018

The integration of renewables is fast-growing, in light of smart grid technology development. As a result, the uncertain nature of renewables and load demand poses significant technical challenges to distribution network (DN) daily operation. To alleviate such issues, price-sensitive demand response and distributed generators can be coordinated to accommodate the renewable energy. However, the investment cost for demand response facilities, i.e., load control switch and advanced metering infrastructure, cannot be ignored, especially when the responsive demand is large. In this paper, an optimal coordinated investment for distributed generator and demand response facilities is proposed, based on a linearized, price-elastic demand response model. To hedge against the uncertainties of renewables and load demand, a two-stage robust investment scheme is proposed, where the investment decisions are optimized in the first stage, and the demand response participation with the coordination of distributed generators is adjusted in the second stage. Simulations on the modified IEEE 33-node and 123-node DN demonstrate the effectiveness of the proposed model.
Smart Pedestrian Crossing Management at Traffic Light Junctions through a Fuzzy-Based Approach
Authors: Pau Giovanni , Campisi Tiziana , Canale Antonino , Severino Alessandro , Collotta Mario , Tesoriere Giovanni
Published: February 2018

In the last few years, numerous research efforts have been conducted to merge the Internet of Things (IoT) with smart city environments. The goal to make a city “smart” is arising as a possible solution to lessen the issues caused by the urban population growth and fast urbanization. Attention also has focused on the pedestrian crossings because they are one of the most dangerous places in the transport field. Information and Communications Technologies (ICT) can undoubtedly be an excellent support in developing infrastructures that can best manage pedestrian crossing. For this reason, this paper introduces a fuzzy logic-based solution able to manage dynamically the traffic lights’ phases in signalized pedestrian crossings. The proposed approach provides the possibility to change the phases of the traffic light taking into account the time of the day and the number of pedestrians about to cross the road. The paper presents a thorough description of the fuzzy logic controller configuration, an in-depth analysis of the application scenario and simulative assessments obtained through Vissim simulations.
Enrichment of Biscuits with Matcha Green Tea Powder: Its Impact on Consumer Acceptability and Acute Metabolic Response
Authors: Phongnarisorn Benjapor , Orfila Caroline , Holmes Melvin , Marshall Lisa
Published: February 2018

Matcha green tea powder (MGTP) is made with finely ground green tea leaves that are rich in phytochemicals, most particularly catechins. Shortbread biscuits were enriched with MGTP and evaluated for consumer acceptability and potential functional health properties. Baking decreased the content of total catechins by 19% compared to dough, although epimerization increased the amount of (+)-gallocatechin gallate at the expense of other catechins such as (−)-epigallocatechin gallate. Consumer acceptability tests using a 9-point hedonic scale showed that consumers preferred enriched biscuits with low content of MGTP (2 g of MGTP 100 g−1 of flour), and an increase of sugar content did not significantly improve the acceptability of MGTP-enriched biscuits. Overall, enrichment of biscuits with MGTP did not significantly affect the postprandial glucose or triglyceride response (area under curve) compared to non-enriched biscuits consumed with water or MGTP drink. Enriching biscuits with Matcha green tea is acceptable to consumers, but may not bring significant postprandial effects.
Characterization of Essential Oils Obtained from Abruzzo Autochthonous Plants: Antioxidant and Antimicrobial Activities Assessment for Food Application
Authors: Pellegrini Marika , Ricci Antonella , Serio Annalisa , Chaves-López Clemencia , Mazzarrino Giovanni , D’Amato Serena , Lo Sterzo Claudio , Paparella Antonello
Published: February 2018

In the present study, the essential oils (EOs) of some officinal plants from Abruzzo territory (Italy) were evaluated for their antimicrobial and antioxidant activities and their volatile fraction chemical characterization. The EOs were extracted from Rosmarinus officinalis, Origanum vulgare, Salvia officinalis, Mentha piperita, Allium sativum, Foeniculum vulgare, Satureja montana, Thymus vulgaris and Coriandrum sativum seeds. The antimicrobial activity was screened against thirteen Gram-positive and Gram-negative strains to determine the Minimal Inhibitory Concentration (MIC). The total phenolic content (TPC) and the antioxidant capacity (AOC) were assessed by means of Folin-Ciocâlteu method, and Trolox Equivalent Antioxidant Capacity with 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (TEAC/ABTS), Ferric Reducing Antioxidant Power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays respectively. Among the nine EOs tested, T. vulgaris, S. montana, O. vulgare and C. sativum EOs showed MIC values ranging from 0.625 to 5 μL/mL. The AOC and TPC results for these species were also interesting. The major components for these EOs were thymol for T. vulgaris (44%) and O. vulgare (40%), linalool (77%) for C. sativum, and carvacrol for S. montana (54%). The results allowed the study to establish that these EOs are good candidates for potential application as biopreservatives in foods and/or food manufacture environments.
Optical Polarimetry and Radio Observations of PKS1510-089 between 2009 and 2013
Authors: Beaklini Pedro , Dominici Tânia , Abraham Zulema
Published: February 2018

The blazar PKS 1510-089 has shown intense activity at γ -rays in the recent years. In this work, we discussed the results of our 7 mm radio continuum and optical polarimetric monitoring between 2009 and 2013. In 2009, we detected a large rotation of the optical polarization angle that we attributed to the ejection of new polarized components. In 2011, after the occurrence of several γ -rays flares, the radio emission started to increase, reaching values never observed before. We interpreted this increase as the consequence of the superposition of several new components ejected during the γ -rays flares. A delay was measured between the maximum in the radio emission and the γ -ray flares, which favors models involving expanding components like the shock-in-jet models. Finally, we tried to understand the polarization angle variability behavior filling the gaps in our observations with published results of other polarimetric campaigns, and using the criterion of minimum variation in the polarization angle between successive observations to solve the 180° multiplicity.
Empowering Retailers to Refuse to Sell Tobacco Products to Minors
Authors: Chen Min-Li , Chou Li-Na , Zheng Ya-Cheng
Published: February 2018

Tobacco smoking and exposure to secondhand smoke are major environmental risk factors that negatively influence health. It is recommended that tobacco product manufacturers and retailers receive empowerment counseling programs to achieve adolescent health targets. The present study conducted an empowerment counseling session to counsel tobacco product retailers in refusing to sell tobacco products to minors. The three stages of this study were conducted from March 2015 to February 2017. The results revealed that 74% of retailers were selling tobacco products to minors at baseline, 40% at stage two and 15% at stage three. These represent significant reductions in selling tobacco products to minors (all stage differences p < 0.001). However, experimental design studies could be used to examine the empowerment counseling program for preventing tobacco sales to minors in the future. Moreover, health care providers should collaborate with tobacco product retailers to design unique empowerment counseling sessions for specific regions to improve retailers’ capabilities for self-management in terms of tobacco hazard prevention.