bluuebunny/crossref_metadata_2025 huggingface dataset:
The Performance Analysis of a Reactor Coolant Pump Hydro-Static Seal in Different Operating Conditions by Reynolds Equations
Authors: Cong Guohui , Zhang Yixun , Zhang Tiejian , Chen Kan
Published: October 2017

The reactor coolant pump is the key equipment of the first loop in nuclear power plant, and the shaft seal is the most important component. The reliability of the shaft seal under various operating conditions directly affects the safe operation of the reactor coolant pump and the plant. At present, the large shaft diameter No.1 shaft seal used in the nuclear power plant is mostly in a hydro-static type with single taper. In order to analyze the No. 1 seal performance which is impacted by the pressure, temperature and speed of the reactor coolant pump, the simplified Reynolds equations is used to calculate the fluid domain of No. 1 seal by the numerical method. The analysis obtains the No. 1 seal surface pressure distribution, then the No. 1 sealing film thickness, leakage rate and other performance parameters under different pressure, temperature and speed conditions are analyzed and results obtained. In the analysis, the deformation of the sealing surface influenced by the temperature is not considered, but the high temperature impact under SBO condition is analyzed and predicted. The influence of speed variation with the increase of centrifugal force in the calculation is considered. The results show that the leakage increases with the increase of pressure, and is more sensitive under low pressure. The leakage quantity increases with the increase of temperature, below 100°C, the leakage is basically in near linear change trend, but in the high temperature about 300°C in SBO condition, the leakage rate increases obviously. For the large diameter hydro-static seal, due to the large rotating radius, the circumferential velocity is relatively high; under the action of centrifugal force the leakage rate is lower when the speed is higher. The calculation results of hydro-static pressure under different pressure level are compared with the experimental results, the calculation results of the trend is consistent with the experimental result, and when the pressure becomes larger, the calculation results and the experimental results are more different. The results also show that although the direct use of the Reynolds equation cannot reflect the interaction influence of fluid, solid and heat transfer, but compared with the test results, the trend of the calculation and the test is the same. In conclusion, the calculation method by Reynolds equations can be used in the guide of reactor coolant pumps No.1 seal design, but the design detailed should be corrected by the real test data.
The Onset of Turbulence: Insights Into the Navier-Stokes Equations
Authors: Rathmann Carl E.
Published: October 2017

For well over 150 years now, theoreticians and practitioners have been developing and teaching students easily visualized models of fluid behavior that distinguish between the laminar and turbulent fluid regimes. Because of an emphasis on applications, perhaps insufficient attention has been paid to actually understanding the mechanisms by which fluids transition between these regimes. Summarized in this paper is the product of four decades of research into the sources of these mechanisms, at least one of which is a direct consequence of the non-linear terms of the Navier-Stokes equation. A scheme utilizing chaotic dynamic effects that become dominant only for sufficiently high Reynolds numbers is explored. This paper is designed to be of interest to faculty in the engineering, chemistry, physics, biology and mathematics disciplines as well as to practitioners in these and related applications.
Energy Saving Analysis and Improvement of Cooling Circulating Water System in M199 Technological Process
Authors: Xiong Zhixiang , Luo Yin
Published: October 2017

M199 is a kind of traditional drug fungicide, which is utilized widely in agriculture. The cooling circulating water system of such a production line consumes so much energy as to build cooling water supply model based on reaction vessel heat transfer mechanism and cooling requirement. The problems of the system is caused from improper pump selection, unreasonable condition adjustment methods, unscientific management, and difficulty in energy consumption evaluation and so on. In order to increase operation efficiency of the system and reduce the waste of energy, this paper surveyed the situation of equipment installation and M199 technological process, then compare the existing energy consumption with that under a variable frequency speed regulation to identify the space for energy saving, eventually complete the analysis of assessment of energy consumption in the whole system. Water supply system of variable pressure and flow is utilized under the premise of meeting the requirement of M199 technological process according to the pump affinity laws and by considering the energy-saving in the pump themselves and their systems so as to refurbish the system and realize the reduction of energy and production costs.
A Multicolor Grid Technique for Volumetric Velocity Measurements
Authors: Dennis Kadeem , Siddiqui Kamran
Published: October 2017

Turbulent flows are three-dimensional by nature. A major challenge in turbulence research is the simultaneous measurement of all three velocity components in three-dimensional space. Recently, Rainbow Volumic Velocimetry (RVV) has emerged as a promising technique to visualize and measure three-dimensional flow fields. The RVV technique projects a multicolor light beam in the measurement region. Currently, the technique utilizes beam color variations in one plane i.e. perpendicular to the camera field of view but is restricted to small measurement volumes.

In this paper, a new approach of light beam projection using a multicolor grid is proposed that allows beam color variations in multiple planes relative to the camera field of view. This enables the extension of the light beam width through multiple color combinations. Details of the technique and its implementation are presented along with the preliminary results that demonstrates the viability of this technique.
Study of Frequency Response of Quartz Crystal Microbalance to Different Wetting States of Micropillar Surfaces
Authors: Su Junwei , Esmaeilzadeh Hamed , Sun Hongwei
Published: October 2017

Enhanced wettability, known as superhydrophobicity or superhydrophilicity has drawn extensive attention in the past for wide range potential applications such as superhydrophobic surfaces for self-cleaning, anti-icing, dropwise condensation, and drag reduction. This research focuses on the investigation of the frequency responses of quartz crystal microbalance (QCM) devices coated with micropillars to the different wetting states of drops. A theoretical model was developed to correlate the resonant frequency shifts of QCMs with the penetrated (Wenzel state) and suspended (Cassie state) states based on the Euler-Bernoulli beam theory. In the experimental validation of the theory, Poly(methyl methacrylate) (PMMA) micropillars were fabricated on the QCMs using nanoimprint lithography (NIL) method and the different wetting states were generated by plasma treatment and chemical coating. The frequency shifts of the QCM device were measured by a network analyzer. A good agreement between experimental measurements and theoretical predictions was obtained. It was found that the micropillars operating in the penetrated state results in one order of magnitude higher frequency shift of QCM than the micropillars in suspended state. There exists a highly nonlinear vibrating behavior of micropillars with different heights in both penetrated and suspended states. The QCM based technology is a valuable tool for studying the wettability of different superhydrophobic or superhydrophilic surfaces.
Application of Plasma Discharges to the Ignition of a Jet Diffusion Flame
Authors: Liao Ying-Hao , Sun Ming-Chien , Lai Ru-Yi
Published: October 2017

The present study experimentally investigates the effect of plasma discharges on the ignition of a laminar methane jet diffusion flame in a stream of co-flow air. The Reynolds number of the jet flame, based on the nominal jet velocity and the nozzle diameter, is approximately Re = 2000. The plasma discharge, a corona type, is produced between two tungsten wires with a diameter of 0.5 mm and a gap of 15 mm. Results show that the application of plasma discharge in a near-nozzle region can ignite the flame. A non-reacting free jet similarity solution is applied to examine the ignition locations and it shows that many of the locations are outside the jet boundary, where the mixture is leaner than stoichiometry. The minimum input power required for flame ignition is seen to increase with radial distance away from the nozzle and decrease with downstream locations. A high input power required for ignition is found to be close to the nozzle exit, where a high strain can be expected. Spectroscopic study confirms the emission spectra in non-thermal air plasma and shows the intensity difference in spectra between discharges that ignite and do not ignite flames.
Power Regeneration of a Bioinspired Electromechanical Propulsive Fin
Authors: Gater Brittany , Bayandor Javid
Published: October 2017

Bioinspired swimming methods have become highly attractive due to the potential for low environmental impact and high efficiency. However, although the efficiency has been quantified for select robotic and theoretical models, this paper explores more directly how requisite power consumption of an undulatory fin is affected by desired swimming speed. It further introduces and quantifies a method for recovering energy from the flow. First, CFD was used to simulate a cross-section of a fish fin with a wave number of 1.2 and a linearly increasing amplitude envelope. Flow speed and fin wave frequency were varied to determine interactive effects on force production and power requirements. The data from these simulations was fitted with polynomial functions over the range used for the study. To determine the potential for power regeneration from the flow, the fin was augmented with a mathematical model of a DC motor and shaft driving it. By incorporating the motor model into the fin analysis, the authors analyzed the amount of power input, or power regeneration, into the system from a constant velocity fluid flow, and developed a relationship between flow velocity and power regeneration. This relationship provides insight into both the level of power regeneration for the fin if held fixed in constant flow, and the minimum flow speed to regenerate energy at a desired rate. The determination of the relationships between efficiency and mode of operation will provide insight into the energetic efficiency of robotic designs using this method. Furthermore, the possibility of power recovery could pave the way for longer lasting underwater robots in extended missions. The determination of both efficiency and power regeneration capability will provide insight into the energetic feasibility of using, and improving on, the current capabilities of bioinspired underwater propulsion.
Towing Tank Experiments for Flapping-Wing Aerodynamics
Authors: Han Jong-Seob , Lee Jong-Wan , Han Jae-Hung
Published: October 2017

This paper presents an empirical approach for flapping-wing aerodynamics using a servo-driven towing tank and a dynamically scale-up robotic manipulator. Time-varying aerodynamic force and moment were measured, and digital particle image velocimetry in multiple cross-sections were conducted. Three case studies showed that the towing tank experiment could be an effective way to investigate the aerodynamic characteristics in detail, which are difficult to be predicted by other conventional approaches. The force and moment measurements clarified that an advance ratio has significant role in governing the LEV behavior and consequent aerodynamic performance of flapping wings. Results for moving sideways showed the effects of the wing-wing and wing-body interaction, and the usefulness of the towing tank experiments for analyzing the flight dynamic characteristics. It was also shown that the towing tank experiments can be applicable to realistic wing motions; test results using the wing kinematics of a living insect in forward flight were well compatible with the trim condition of the insect.
Dynamic Stability of Flapping-Wing Micro Air Vehicles With Unsteady Aerodynamic Model
Authors: Han Jae-Hung , Nguyen Anh Tuan
Published: October 2017

In this paper, we introduce a numerical approach based on an unsteady aerodynamic model to study the dynamic stability of insect-like flapping-wing micro air vehicles (FWMAVs). Trimmed free flight of FWMAVs is simulated by a framework that couples the unsteady potential-based aerodynamic model and a multibody dynamics code. Flight dynamic modal structures are obtained by a linearization method. This paper also briefly presents the applications of the abovementioned approach to study several problems associated with the flight dynamic stability of FWMAVs, such as the effects of body aerodynamics and wing flexibility, as well as the ground effect.
Wind-Turbine Vibration Reduction Using Flow Control Devices
Authors: Kim Ho-Young , Han Jae-Hung
Published: October 2017

The size of wind turbine blades has been continuously increased for better aerodynamic efficiency. However, the large scale blades induce loud noise and vibration as well as the increased difficulty in maintenance; all of these eventually causes the increase in the cost of energy. The vibration of wind turbines is mainly caused by wind turbulence, wind shear, and tower shadow. These causes change in local angle of attack of wind turbine blades and create mostly periodic vibration.

In this work, a flow control device is applied for vibration reduction of wind turbine blades. The conventional role of flow control devices is to increase lift coefficient and to reduce drag coefficient by flow separation delay. In this research, flow control device is used to make a flat slope of lift coefficient in specific angle of attack range for vibration reduction; lift coefficient is not always increased but also decreased, too.

To manipulate the lift coefficient slope, several types of flow separation controller are considered. Finally, a plasma actuator is selected because the minimal structural modification is necessary while providing sufficient lift coefficient control. The plasma actuator is attached to an airfoil to blow the jet upwind to decrease the lift. Computational fluid dynamics simulation is conducted to estimate the flow control performance of the plasma actuator. Experiments are conducted on a DU35-A17 airfoil to verify the lift coefficient manipulation performance of the plasma actuator.
Heat Transfer of Pico Projector Using a Piezoelectric Fan With an Aluminum Blade
Authors: Shyu Jin-Cherng , Jheng Shu-Kai
Published: October 2017

A 120 mm × 53 mm × 19 mm horizontally-oriented pico projector in which both a pin-fin array and a piezoelectric fan were installed was tested to measure the thermal resistance at various heating powers. The operating frequency of the 40 mm × 10 mm aluminum piezoelectric fan ranged from 242 Hz to 257 Hz. The heat transfer coefficient of the pin-fin array was also estimated based on a thermal resistance network of the pico projector. The results showed that the thermal resistance of the pico projector which had a piezoelectric fan vibrating at a specific frequency would not monotonically reduce as the heating power increased. The heat transfer coefficient of the 1.5-mm-wide pin-fin array was higher than that of the 2.0-mm-wide pin-fin array at a given fan tip velocity ranging from 0.26 m/s to 0.76 m/s. The highest heat transfer coefficient of the 1.5-mm-wide pin-fin array reached approximately 21 W/m2K, while the highest heat transfer coefficient of the 2.0-mm-wide pin-fin array was approximately 16 W/m2K. A correlation between Nusselt number of the pin-fin array and Reynolds number was also developed in this study in a form of Nu = 0.3526Re0.1774.
Unsteady Vortex Interactions for Performance Enhancement of a Free Flying Dragonfly
Authors: Hefler Csaba , Noda Ryusuke , Shyy Wei , Qiu Huihe
Published: October 2017

Bioinspired designs offer a viable solution to the design challenges of micro air vehicles (MAVs) desired to operate in the same size region under similar conditions as flying vertebrates and insects. Inspired by our previous studies of tethered live dragonflies, here, a quantitative characterization of the unsteady aerodynamic features of a live, freely flying dragonfly under well-established level flight condition will be presented. In particular with regard of the span-wise features of vortex interactions between the fore- and hind-pairs of wings, that highly contributes to the flight agility and efficiency of dragonflies. Flow fields of free flying dragonflies in still air have been measured by time-resolved stereo particle image velocimetry (TRS_PIV). A specifically designed dark flight chamber has been built, where hand hold dragonflies (Pantala flavescens) were released and made to fly nearly parallel to the measurement plane toward a guiding light. Realistic kinematics of the dragonfly wings in free flight were measured by filming with 2 synchronized high-speed video cameras. Using the recorded images, several dozens of landmarks on the fore- and hind-wing surfaces and several landmarks on the body were traced with high precision and the three-dimensional coordinates were then reconstructed with a direct linear transformation (DLT) method. Using the reconstructed wing-body model, Navier-Stokes-based computational fluid dynamics (CFD) analyses, with wing shapes prescribed based on the experimental measurement, dynamically moving multi blocked, and an overset-grid system were conducted. The numerical results are in overall agreement with the PIV data, and the combined numerical and experimental approach offers valuable insight into aerodynamic analyses. The results show that the interaction with the forewing leading edge vortex (LEV) strongly influences the flow structures around the inner spanwise region of the hindwing, while aerodynamic enhancement via vortex capture in the outer span is observed. The interaction depends not solely on wing phasing, geometrical arrangement, but also the flight mission.
Characterization of Distorted Fluid Flow Along Advanced High-Bypass Jet Engine Subjected to Foreign Object Ingestion
Authors: Song Yangkun , Bayandor Javid
Published: October 2017

In this study, a non-linear fluid-solid interaction (FSI) methodology is uniquely developed to simulate the aerodynamic interaction and disturbance of flow along a high-bypass propulsion system subjected to foreign object ingestion (FOI). For the analysis, a time explicit finite element analysis is applied with an advanced computational scheme, Arbitrary Lagrangian-Eulerian (ALE). The advanced finite element formulation is able to successfully demonstrate the interaction between air and the high-bypass jet engine subjected to a soft body FOI by solving both solid and fluid continua simultaneously. As a result, the proposed damage modeling methodology simulates the progressive failure caused by the exertion of aerodynamics over the damaged and undamaged components.
CFD Simulation of a Multi-Stage Centrifugal Pump
Authors: Ding H. , Gao W. , Gao H.
Published: October 2017

In this paper, a CFD software package is applied to the performance prediction of a 14-stage centrifugal pump with opposed impeller configuration. In this study, the fluid volumes of the complete multistage pump are simulated together. The CFD model includes not only all the main flow channels from inlet to discharge, but also all the secondary flow passages such as wearing ring leakage and seal flush. The CFD model and the simulation results will be presented and discussed in detail. The CFD prediction will be compared with available experiment data.
New distribution and host records for Ornithodoros capensis Neumann and Ornithodoros sawaii Kitaoka and Suzuki (Acari: Ixodida: Argasidae) collected from Black-tailed Gull, Larus crassirostris, nestlings and nest soil and litter on Hong and Nan Islands, Republic of Korea
Authors: Kim Heung-Chul , Kim Miran , Kwon Young-Soo , Hong Mi-Jin , Park Chang-Uk , Yun Seok-Min , Lee Won-Ja , Chong Sung-Tae , Hang Jun , Klein Terry A. , Robbins Richard George
Published: October 2017

The 65th Medical Brigade and Medical Department Activity-Korea, in collaboration with the Migratory Birds Research Center, National Park Research Institute, conducted a migratory bird tick-borne disease surveillance program during 2014–2015 on two small, remote, uninhabited islands, Hong (Gull) Island, southern Gyeongnam Province, and Nan Island, western Chungnam Province, Republic of Korea (ROK). Argasid ticks were collected from Black-tailed Gull (Larus crassirostris) nestlings that had recently died and associated nest soil/litter, and all tick life history stages were identified morphologically. Because morphological keys are unreliable for the identification of adult and nymphal argasid ticks, identifications were confirmed by genotyping using polymerase chain reaction techniques. A total of 29 Ornithodoros capensis larvae and 2 Ornithodoros sawaii larvae were collected from 4 of 7 (57.1%) Black-tailed Gull nestlings that had recently died. An additional five O. capensis (2 males, 1 nymph, and 2 larvae) were collected from nest soil/litter. Only O. sawaii larvae (2/41, 4.9%) were collected from dead Black-tailed Gull nestlings on Nan Island. This is the first report of O. capensis from these seabird breeding islands.
Zeroth-order resonance phenomenon in an acoustic composite right/left-handed metamaterial resonator
Authors: Kim Wan-Gu , Kang Hwi Suk , Yoon Suk Wang , Lee Kang Il
Published: October 2017

This study proposes an acoustic theory that describes the resonance phenomena in a resonator made of acoustic composite right/left-handed (CRLH) metamaterials, and verifies it through numerical simulation. The established theory for a microwave CRLH metamaterial resonator is adapted to explain the resonance phenomena in an acoustic CRLH metamaterial resonator. In particular, attention is focused on the zeroth-order resonance phenomenon which has several interesting properties. When a resonator is composed of a CRLH metamaterial, a resonance with a flat acoustic field distribution may occur at one of the frequencies where the wavenumber becomes zero. This resonance is called zeroth-order resonance. Through numerical simulation, such unusual resonance phenomenon in acoustics is observed in more detail and the proposed theory is verified. The results of the theory and the numerical simulation clearly show that zeroth-order resonance can exist at those frequencies where the acoustic field distribution is flat due to infinite wavelength. It is also shown that the resonance frequency and the Q factor of this resonance depend on the boundary condition at both ends of the resonator, and they basically do not change even when the number of units is reduced or increased.
Interdisciplinary Research Centers: A Pathway for Solving Complex Problems
Authors: Sefton JoEllen M. , Games Kenneth A.
Published: October 2017

Colleges and universities increasingly face pressure to take the lead in solving complex problems. Developing and sustaining interdisciplinary research centers that collaborate with community partners can be an effective method of approaching complex challenges. We use the example of interdisciplinary research centers designed to specifically work with tactical athlete organizations (e.g., military, police, fire) as one example of how research centers can be developed and produce important outcomes. A 10-step process is outlined for finding partners, executing projects, and growing research centers which are mutually beneficial to the partner organization and the academic institution. With vision, commitment, and persistence, interdisciplinary research centers can solve complex problems and have meaningful impacts in the community.
Lessons Learned About Outreach and Engagement at the Michigan State University Institute for the Study of Youth Sports
Authors: Gould Daniel
Published: October 2017

The mission of the Institute for the Study of Youth Sports (ISYS) is to provide leadership, scholarship, and outreach that “transforms” the face of youth sports in ways that maximize the beneficial physical, psychological, and social effects of participation for children and youth while minimizing detrimental effects. Since its inception in 1978, ISYS has partnered with numerous organizations to promote healthy youth sports participation. In this article, the general steps ISYS takes to form and facilitate partnerships are addressed. Four long-term partnerships are also described. The services provided to these organizations are described and the advantages and challenges of working with partners, in general, are delineated. How these partnerships are used to facilitate the teaching, outreach-engagement, and scholarship components of the Michigan State University land grant mission are also described. The case of ISYS shows that conducting community outreach and engagement projects greatly enhance the scholarly mission of the university.
An Interdisciplinary Approach to a Well-Rounded Campus Healthcare Delivery System
Authors: Bartz-Smith Shari D. , Campbell Amy
Published: October 2017

An injury care clinic (ICC) as part of a comprehensive campus-wide healthcare system is a cost-effective way to optimize the flow of patient care utilizing a collaborative model of healthcare in a time of physician shortage. Services include: basic first aid, injury evaluation, acute injury care, basic rehabilitation, preventative techniques including taping and stretching, and professional referrals. The ICC provides care to previously underserved campus community members, focusing on: club sport and intramural athletes, recreation center users, and the general student body, in addition to faculty and staff, going beyond the varsity athlete. The ICC functions through the efforts of athletic trainers, physicians, fitness specialists, administrators, faculty, and students across disciplines. After 3 years, the clinic has serviced more than 2,500 unique patients exceeding 4,800 patient encounters, demonstrating outcomes that access to affordable healthcare options with a licensed healthcare provider are warranted and needed.
Establishing Partnerships for Effective Academic Programs
Authors: Morrissey Joanna L. , Beckett Joseph A. , Sherman Ross , Leininger Lisa J.
Published: October 2017

As undergraduate students prepare to enter the workforce and become engaged members in their communities, it is necessary for universities to provide students with opportunities and resources to develop the knowledge, skills, and attitudes needed to be successful in their professional, personal, and social pursuits. Experiential learning is one approach that may be used to facilitate and strengthen the learning process for undergraduate students. Grounded in experiential learning, Kinesiology-specific service learning and internship programs can help students develop the skillset needed to be successful in their major and future careers. To best facilitate students’ learning, it is imperative that such academic programs build collaborative, sustainable and genuine campus-community partnerships. This paper presents a series of practical and successful partnership-building strategies from three unique institutions.
Oral Tobramycin Prophylaxis Prior to Colorectal Surgery Is Not Associated with Systemic Uptake
Authors: Mulder T. , Kluytmans-van den Bergh M. F. Q. , Crolla R. M. P. H. , Ermens A. A. M. , Romme J. , van‘t Veer N. E. , Kluytmans J. A. J. W.
Published: October 2017

Preoperative oral prophylaxis with nonabsorbable antibiotics has been reported to reduce the risk of surgical site infections after colorectal surgery. This prospective study was conducted to evaluate the risk of toxic side effects by measuring postoperative serum tobramycin levels in patients who received a 3-day prophylaxis with tobramycin and colistin prior to colorectal surgery. In all patients, serum tobramycin concentrations were below the detection limit (0.3 mg/liter), implying a low risk of toxicity.
Antimicrobial Activities of Aztreonam-Avibactam and Comparator Agents against Contemporary (2016) Clinical Enterobacteriaceae Isolates
Authors: Sader Helio S. , Mendes Rodrigo E. , Pfaller Michael A. , Shortridge Dee , Flamm Robert K. , Castanheira Mariana
Published: October 2017

A total of 10,451 contemporary (2016)
Enterobacteriaceae
isolates from 84 U.S. medical centers and 116 metallo-β-lactamase- and/or OXA-48-like-producing
Enterobacteriaceae
isolates from other countries were tested against aztreonam-avibactam and comparators. All U.S. isolates were inhibited at aztreonam-avibactam MICs of ≤8 μg/ml (MIC
50
, ≤0.03 μg/ml; MIC
90
, 0.12 μg/ml), including
Klebsiella pneumoniae
carbapenemase-producing isolates (
n
= 102; MIC
50
, 0.25 μg/ml; MIC
90
, 0.5 μg/ml), multidrug-resistant isolates (
n
= 876; MIC
50
, 0.06 μg/ml; MIC
90
, 0.25 μg/ml), and extensively drug-resistant isolates (
n
= 111; MIC
50
, 0.12 μg/ml; MIC
90
, 0.5 μg/ml). The highest aztreonam-avibactam MIC value among ex-U.S. isolates was 4 μg/ml.
Suppression of a Thermosensitive
zipA
Cell Division Mutant by Altering Amino Acid Metabolism
Authors: Vega Daniel E. , Margolin William
Published: October 2017

ZipA is essential for cell division in
Escherichia coli
, acting early in the process to anchor polymers of FtsZ to the cytoplasmic membrane. Along with FtsA, FtsZ and ZipA form a proto-ring at midcell that recruits additional proteins to eventually build the division septum. Cells carrying the thermosensitive
zipA1
allele divide fairly normally at 30°C in rich medium but cease dividing at temperatures above 34°C, forming long filaments. In a search for suppressors of the
zipA1
allele, we found that deletions of specific genes involved in amino acid biosynthesis could partially rescue cell growth and division at 34°C or 37°C but not at 42°C. Notably, although a diverse group of amino acid biosynthesis gene deletions could partially rescue the growth of
zipA1
cells at 34°C, only deletions of genes related to the biosynthesis of threonine, glycine, serine, and methionine could rescue growth at 37°C. Adding exogenous pyridoxal 5-phosphate (PLP), a cofactor for many of the enzymes affected by this study, partially suppressed
zipA1
mutant thermosensitivity. For many of the deletions, PLP had an additive rescuing effect on the
zipA1
mutant. Moreover, added PLP partially suppressed the thermosensitivity of
ftsQ
and
ftsK
mutants and weakly suppressed an
ftsI
mutant, but it failed to suppress
ftsA
or
ftsZ
thermosensitive mutants. Along with the ability of a deletion of
metC
to partially suppress the
ftsK
mutant, our results suggest that perturbations of amino acid metabolic pathways, particularly those that redirect the flow of carbon away from the synthesis of threonine, glycine, or methionine, are able to partially rescue some cell division defects.

IMPORTANCE
Cell division of bacteria, such as
Escherichia coli
, is essential for their successful colonization. It is becoming increasingly clear that nutritional status and central metabolism can affect bacterial size and shape; for example, a metabolic enzyme (OpgH) can moonlight as a regulator of FtsZ, an essential cell division protein. Here, we demonstrate a link between amino acid metabolism and ZipA, another essential cell division protein that binds directly to FtsZ and tethers it to the cytoplasmic membrane. Our evidence suggests that altering flux through the methionine-threonine-glycine-serine pathways and supplementing with the enzyme cofactor pyridoxal-5-phosphate can partially compensate for an otherwise lethal defect in ZipA, as well as several other cell division proteins.
Transcatheter occlusion of the patent ductus arteriosus in premature infants weighing less than 1200 g
Authors: Morville Patrice , Douchin Stephanie , Bouvaist Helene , Dauphin Claire
Published: October 2017

Objectives

Over the last few decades different strategies have been proposed to treat persistent ductal patency in premature infants. The advent of the Amplatzer Duct Occluder II Additional Size (ADOIIAS) provided the potential to close the patent ductus arteriosus (PDA). Opinions differ on the significance and treatment of PDA in premature neonates. Because surgical ligation and medical therapy both have their drawbacks, interventional catheterisation can be considered as an alternative means of closing the ductus arteriosus. Our aim was to analyse the feasibility, safety and efficacy of this device in premature infants weighing <1200 g at procedure.

Methods

Eighteen premature infants underwent transcatheter closure. The procedure was performed in the catheterisation laboratory by venous cannulation without angiography. The position of the occluder was directed by X-ray and ultrasound. We looked at procedural details, device size selection, complications and short-term and mid-term outcomes.

Results

Eighteen infants born at gestational ages ranging between 23.6 and 29+6 weeks (mean±SD 25+6±3 weeks) underwent transcatheter PDA closure. Their mean age and weight at the time of the procedure was 20 days (range 8–44 days) and 980 g (range 680–1200 g), respectively. The mean PDA and device waist diameters were 3.2±0.6 mm (range 2.2–4 mm) and 4.5±0.6 mm, respectively, and the mean PDA and device lengths were 4.3±1.2 mm (range 2–10 mm) and 2.5±0.9 mm, respectively. Complete closure was achieved in all but one patient. There was no device migration. One patient developed a left pulmonary artery obstruction. Three infants died. Two deaths were related to complications of prematurity and one to the procedure.

Conclusions

Transcatheter closure of a PDA is feasible in very low weight infants with ADOIIAS and is an alternative to surgery. Success requires perfect selection and placement of the occluder.
Vascular consideration in repair of total scalp avulsion
Authors: Karibe Jun , Minabe Toshiharu
Published: October 2017

Successful total scalp replantation was performed in our case. Based on the angiosome concept and anatomical study, the avulsed scalp survived with unilateral anastomosis of the superficial temporal artery and superficial temporal vein, largely due to the presence of rich arterial and venous arcades in the scalp. The patient currently has no problems with activities of daily living, although total hypoaesthesia and dysfunction of the left frontal muscle of the forehead are present. In addition, the combined findings of hair growth pattern indicated the vascular territories of the scalp skin.
Birt-Hogg-Dubé syndrome: awareness is important!
Authors: Oliveira Rui Caetano , Tavares Edgar , Sousa Vítor , Figueiredo Arnaldo
Published: October 2017

Birt-Hogg-Dubé (BHD) is a rare syndrome of inherited renal cell carcinomas, characterised by cutaneous lesions and pulmonary cysts and pneumothorax in a vast majority of the patients. Awareness of this syndrome is important in order to refer patients for genetic counselling and personalised follow-up as soon as possible. We describe a case of a 30-year-old female referred to our institution due to incidental discovery of solid bilateral renal masses. Renal biopsies were consistent with chromophobe tumour, and bilateral nephrectomy was performed. Gross examination revealed deformed kidneys with 28 brown and solid lesions, size variable between 0.1 and 6 cm, histologically corresponding to renal cell carcinomas, chromophobe type. Genetic test was required that showed a c.573delGAinsT frameshift mutation in heterozigosity at the folliculin gene, consistent with BHD diagnosis.
Gaussian black holes in Rastall gravity
Authors: Spallucci Euro , Smailagic Anais
Published: October 2017

In this short note we present the solution of Rastall gravity equations sourced by a Gaussian matter distribution. We find that the black hole metric shares all the common features of other regular, General Relativity BH solutions discussed in the literature: there is no curvature singularity and the Hawking radiation leaves a remnant at zero temperature in the form of a massive ordinary particle.
A smooth constant-roll to a slow-roll modular inflation transition
Authors: Oikonomou V. K.
Published: October 2017

In this work, we investigate how a smooth transition from a constant-roll to a slow-roll inflationary era may be realized in the context of a canonical scalar field theory. We study in some detail the dynamical evolution of the cosmological system, and we investigate whether a stable attractor exists, both numerically and analytically. We also investigate the slow-roll era and as we demonstrate, the partially compatibility of the resulting scalar theory may be achieved with the potential of the latter belonging to a class of modular inflationary potentials. The novel features of the constant-roll to slow-roll transition which we achieved are firstly that it is not compelling for the slow-roll era to last for [Formula: see text]–60 [Formula: see text]-foldings, but it may last for a smaller number of [Formula: see text]-foldings, since some [Formula: see text]-foldings may occur during the constant-roll era. Secondly, when the slow-roll era occurs after the constant-roll era, the graceful exit from inflation may occur, a feature absent in the constant-roll scenario, due to the stability properties of the final attractor in the constant-roll case.
The Unruh effect for eccentric uniformly rotating observers
Authors: Ramezani-Aval H.
Published: October 2017

It is common to use Galilean rotational transformation (GRT) to investigate the Unruh effect for uniformly rotating observers. However, the rotating observer in this subject is an eccentric observer while GRT is only valid for centrally rotating observers. Thus, the reliability of the results of applying GRT to the study of the Unruh effect might be considered as questionable. In this work, the rotational analog of the Unruh effect is investigated by employing two relativistic rotational transformations corresponding to the eccentric rotating observer, and it is shown that in both cases, the detector response function is nonzero. It is also shown that although consecutive Lorentz transformations cannot give a frame within which the canonical construction can be carried out, the expectation value of particle number operator in canonical approach will be zero if we use modified Franklin transformation. These conclusions reinforce the claim that correspondence between vacuum states defined via canonical field theory and a detector is broken for rotating observers. Some previous conclusions are commented on and some controversies are also discussed.
Image Noise Reduction Method Based on Compatibility with Adjacent Pixels
Authors: Farshi Taymaz Rahkar
Published: October 2017

This paper proposes an efficient noise reduction method for gray and color images that are contaminated by salt-and-pepper noise. In the proposed method, the pixels that are more compatible with adjacent pixels are replaced with target (noisy) pixels. The algorithm is applied on noisy Lena and Mansion images that are contaminated by salt-and-pepper noise with 0.1 and 0.2 noise intensities. Although this method is developed for reducing noise from the images that are contaminated by salt-and-pepper noise, it can also reduce the noise from the images that are contaminated by other types of noises; yet it is more efficient for reducing salt-and-pepper noise. Both numerical and visual comparisons are demonstrated in the experimental simulations. The results show the proposed algorithm can successfully remove impulse noise from images that are contaminated by salt-and-pepper noise.
Inter-Image Similarity-Based Fast Adaptive Block Size Vector Quantizer for Image Coding
Authors: Abdelwahab Ahmed A.
Published: October 2017

Block coding is well known in the digital image coding literature. Vector quantization and transform coding are examples of well-known block coding techniques. Different images have many similar spatial blocks introducing inter-image similarity. The smaller the block size, the higher the inter-image similarity. In this paper, a new block coding algorithm based on inter-image similarity is proposed where it is claimed that any original image can be reconstructed from the blocks of any other image. The proposed algorithm is simply a vector quantization without the need to a codebook design algorithm and using matrix operations-based fast full search algorithm to find the local minimum root-mean-square error distortion measure to find the most similar code block to the input block. The proposed algorithm is applied in both spatial and transform domains with adaptive code block size. In the spatial domain, the encoding process has fidelity as high as 36.07[Formula: see text]dB with bit rate of 2.22[Formula: see text]bpp, while in the transform domain, the encoded image has good fidelity of 34.94[Formula: see text]dB with bit rate as low as 0.72[Formula: see text]bpp on the average. Moreover, the code image can be used as a secret key to provide secure communications.
Human Action Classification Based on Silhouette Indexed Interest Points for Multiple Domains
Authors: Alcantara Marlon F. , Pedrini Helio , Cao Yu
Published: October 2017

Recent technological advances in the acquisition and dissemination of videos have driven the development of several applications in the context of human action recognition, such as automatic surveillance, strategic planning, crime prevention and traffic monitoring, among others. Despite this large number of applications, several techniques found in the literature are specialized for a particular purpose, working only for a limited scope of actions. To improve the current scenario, this work proposes and evaluates the development of a flexible descriptor and a methodology for identifying human actions in different domains. The classification process utilizes a judgement mechanism for iteratively refining its outcome in order to converge to a decision that best fits the recognizer. Experiments are conducted on five public datasets with different characteristics, from events containing few actions to more complex scenarios involving a large number of people and interaction with objects. Results have demonstrated that the proposed approach provides a proper balance between computational speed and accuracy rate. Therefore, the developed prototype represents a promising tool for real-time applications.
Novel Results for Induced l∞ Stability for Digital Filters with External Noise
Authors: Kokil Priyanka , Arockiaraj S. Xavier
Published: October 2017

This paper establishes novel criteria for the induced [Formula: see text] stability to avoid overflow oscillations in fixed-point digital filters with generalized overflow non-linearities and external noise. The proposed linear matrix inequality (LMI)-based criteria ensure exponential stability as well as confirm reduction in the influence of external noise. The generalized overflow non-linearities which are considered for analysis commonly occur in practice, viz. saturation, zeroing, two's complement, and triangular. The presented approach unifies a string of existing results which are derived by considering saturation non-linearities and external interference. Simulation examples are shown to validate the usefulness of the proposed approach.
A Novel Hand Gesture Recognition Based on High-Level Features
Authors: Li Jing , Wang Jianxin , Ju Zhaojie
Published: October 2017

Gesture recognition plays an important role in human–computer interaction. However, most existing methods are complex and time-consuming, which limit the use of gesture recognition in real-time environments. In this paper, we propose a static gesture recognition system that combines depth information and skeleton data to classify gestures. Through feature fusion, hand digit gestures of 0–9 can be recognized accurately and efficiently. According to the experimental results, the proposed gesture recognition system is effective and robust, which is invariant to complex background, illumination changes, reversal, structural distortion, rotation, etc. We have tested the system both online and offline which proved that our system is satisfactory to real-time requirements, and therefore it can be applied to gesture recognition in real-world human–computer interaction systems.
EVALUATION OF EFFECTS OF COLLABORATIVE PATTERNS ON THE EFFICIENCY OF SCIENTIFIC NETWORKS USING SIMULATION
Authors: TAJADDOD ALIZADEH DORSA , SCHIFFAUEROVA ANDREA
Published: October 2017

The objective of this work is to investigate the role of individual scientists and their collaborations in knowledge creation networks. In order to study the networks in their dynamic context, an agent-based simulation model is developed using real data based on the Canadian biotechnology publications. We observe that while the repetitiveness of the collaborative relationships among scientists shows negative effects, the presence of the gatekeepers is found to be critical for the overall efficiency of the network. We also find positive impact of star scientists on the network productivity, but their negative effects on the flow of knowledge are detected as well.
THE ROLE OF MARKETING-ENABLED DATA ANALYTICS CAPABILITY AND ORGANISATIONAL AGILITY FOR INNOVATION: EMPIRICAL EVIDENCE FROM GERMAN FIRMS
Authors: SHURADZE GIORGI , BOGODISTOV YEVGEN , WAGNER HEINZ-THEO
Published: October 2017

Recent shifts in technology have created a data-rich environment and made it necessary for firms to develop new capabilities to cope with these changes. To address this challenge, this study introduces marketing-enabled data analytics capability, a specific type of information technology (IT) capability that enables firms to better understand customer needs and achieve a competitive advantage in the digital era. Using empirical results collected via online survey, we argue that marketing-enabled data analytics capability, which comprises data analytics infrastructure, marketing-oriented analytics expertise, and IT–marketing social capital, positively influences a firm’s organisational agility and innovation success. Moreover, the results show that organisational agility partially mediates the relationship between marketing-enabled data analytics capability and innovation success. By developing the construct of marketing-enabled data analytics capability, this paper lays a foundation for future research on this new type of IT capability, which is critical in the digitization process.
Studies of the Influence of Gold Nanoparticles on Characteristics of Mesenchymal Stem Cells
Authors: Volkova Nataliia , Pavlovich Olena , Fesenko Olena , Budnyk Oksana , Kovalchuk Serhii , Goltsev Anatoliy
Published: October 2017

The aim of the present study is to determine what effect the different concentrations of 15 nm gold nanoparticles (AuNPs) will have on the immunophenotype, synthesis collagen type I, ability to direct differentiation and spectroscopic characteristics of bone marrow mesenchymal stem cells (MSCs). The AuNPs in concentrations of 1.5–9 μg/ml did not lead to changes in the level of expression of CD 45, CD 90, and CD 73. It should be noted that AuNPs in concentrations of 6 and 9 μg/ml led to a decrease in CD 44 cells by 6% and 9%, respectively. The content of CD 105 cells was reduced by 5% when AuNPs were applied at a concentration of 9 μg/ml. It was found that AuNPs in concentrations of 1.5–6 μg/ml are safe for MSCs, while the increase up to 9 μg/ml has a toxic effect, manifested by the reduction of synthesis collagen type I and ability of adipogenic differentiation. IR spectroscopy data have shown that the AuNPs at concentrations of 9 μg/ml under conditions of adipogenic differentiation to MSCs lead to the destruction processes in the cells. The obtained results are related to the field of applied nanotechnology, which extends to regenerative medicine, especially in development of bioimplantology.