bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Numerical Computation of Enzyme Kinetic Parameters
Authors: Dimitrov Stanko , Velikova Gergana , Beschkov Venko , Markov Svetoslav 
Published: March 2015

We consider the enzyme kinetic reaction scheme originally proposed by V. HenriВ of single enzyme-substrate dynamics where two fractions of the enzyme - free and bound - are involved. Henri's scheme involves four concentrations and three rate constants and via the mass action law it is translated into a systemВ of four ODE's. On two case studies we demonstrate how the rate constants can be computed whenever time course experimental data are available. The obtained results are compared with analogous results implied by classical Michaelis-Menten model. Our approach focuses on the uncertainties in the experimental data, as well as on the use of contemporary computational tools such as CAS Mathematica.
Sigmoidal Functions: Some Computational and Modelling Aspects
Authors: Kyurkchiev Nikolay , Markov Svetoslav 
Published: March 2015

We В focus on some computational, modelling and approximation issues related to the logistic sigmoidal function and to Heaviside step function. В The Hausdorff approximation of the Heaviside interval step function by sigmoidal functions is discussed from various computational and modelling aspects. Some relations between Verhulst model and certain biochemical reaction equations are discussed and analyzed. Numerical examples are presented using CAS Mathematica.
Development of an Oil and Gas Refinery Inspection Robot
Authors: Steele John P. H. , Han Qi , Karki Hamad , Al-Wahedi Khaled , Ayoade Adewole A. , Sweatt Marshall R. , Albert Daniel P. , Yearsley W. Alex 
Published: March 2015

Oil and gas refineries present challenging environments in which to work and operate, especially in places like the Middle East where temperatures can reach 50 °C and sand storms which can reduce visibility to a few meters. In addition, there can be gas or steam leaks which present health and safety hazards to the workers. At present, continuous operation of these plants requires that human workers venture out into these conditions in order to observe and report on the conditions within the plant. The goal of this work is to design, fabricate, assemble, and test an inspection robot in an effort to reduce the exposure and risks to human operators while increasing the flexibility and range of remote observations provided by a mobile robot.
In this paper, we will report on the design approach taken, the subsystems identified and developed, the software environment chosen, and the application tasks envisioned. We will also report on the challenges of developing a robust localization algorithm for use in the challenging environment of a refinery as well as the needs for robust wireless communications in order to maintain command and control from the operators control room. An overview of the five-degree-of-freedom arm designed and fabricated, and its real-time control will also be presented. Results from GPS navigation and localization experiments will be presented. While average errors during parked operations were often less than one meter for the WAAS enabled GPS system, locational errors during dynamic operations were often more than three meters. This is due to multi-path signals near building structures and piping infrastructure. Real-time arm control has been implemented using FPGAs and while tuning presented some challenge, the FPGA has provided smooth and repeatable operation. Sensors include gas detectors, acoustic sensors, thermal imaging, and video camera streaming. In addition, we will report on a multi-faceted approach to localization using three different sensor technologies and integrated using a Kalman filter.
Cutting Speed and Feedrate Based Analysis of Cutting Forces in the One Shot Drilling (OSD) of CFRC/Al Hybrid Stacks
Authors: Salguero Jorge , Ponce Moises Batista , Fernandez-Vidal Severo R. , Mayuet Pedro , Rosales Edwing I. , Marcos Mariano 
Published: March 2015

Hybrid stacks structures Composite/Metallic Alloy are commonly applied for manufacturing of structural components in different industrial sectors. Particularly, they are increasingly widely used in the aerospace industry because of these materials combine light weight with a high mechanical resistance. This fact helps to increase the load without needing to increment — even diminishing — the energetic consumption. Carbon Fiber Reinforced Composites (CFRC) and light alloys, such as Aluminium or Titanium based alloys, are usually combined for performing those stacks.
CFRC/Alloy stacks based airship structural elements commonly require drilling operations for the posterior assembly tasks. However, the machining processes of Non-Metal Matrix Composites (NMMC), and particularly CFRC, show significant differences with the machining processes of metallic materials. Because of this, it is very difficult to find a joint only one of cutting parameters for drilling these structures using One Shot Drilling (OSD) techniques.
In this work, a study of the cutting forces developed in the dry-OSD of CFRC/UNS A92024 stacks has been achieved as a function of the cutting speed and feedrate parameters. Dry drilling tests have been performed using different parameters for drilling CFRC and alloy. A change of the parameters in the interface between CFRC and the alloy has been programmed through a CAM software.
Higher cutting force values have been observed in the case of the Aluminium alloys. For both materials, obtained results have shown a strong increase of the cutting force with the increase of feedrate. However, only a slight increase with cutting speed has been observed.
The evolution of the cutting force as a function of the holes number has shown a trend to increase only for highest feedrates when CFRC/Alloy is drilled. From the obtained results a F(f,v) model has been proposed.
Tensairity Concept Applied to Lighter-Than-Air Vehicles for Light-Weight Structures
Authors: Suñol Anna , Vucinic Dean , De Laet Lars 
Published: March 2015

Airships have the intrinsic advantages of Lighter-Than-Air (LTA) vehicles: minimal energy consumption and Vertical Take-Off and Landing (VTOL) characteristics. Due to these advantages, significant efforts are being taken in order to investigate new applications and technical improvements. More specifically, there is a renewed interest in large airships for heavy payload transportation and for stratospheric airships. The design of large airships is a big challenge, especially when considering the structural point of view, since big volumes imply high loads, and since light weight is a major requirement for this type of vehicles. In this context, a light-weight structure is proposed by applying the structural Tensairity concept. A Tensairity beam consists of a rigid air beam designed on the basis of complete functional separation of the different structural elements, allowing for a maximum optimization. In this paper, the justification of the feasibility of applying Tensairity components in airships is discussed based on two criteria. The first criterion is the justification of the need of a lightweight structure by a state of the art analysis and a study of the principal characteristics of the existing types of LTA vehicles structures. The second criterion is a preliminary technical analysis, which aims to clarify if the load bearing behavior of airships is suited for the application of the Tensairity concept. Moreover, the bases for the development of the concept for the LTA vehicles structures are established.
The advantages and drawbacks of the traditional rigid airships structure in comparison with a non-rigid structure has been analyzed, which conclusion is that the use of a rigid structure is convenient for large airships, since it reduces significantly the stresses of the envelope, but at the same time decreases the payload efficiency due to the addition of the structure’s weight. Moreover, the analysis of the load bearing behavior suggests the technical feasibility of applying Tensairity components, since airships have to withstand high bending moments and Tensairity structures are appropriate for withstanding such loads. Finally, the principal guidelines for defining the various load cases and for modeling Tensairity beams have been defined. In order to confirm the hypothesis of the suitability of Tensairity structures on airships, extensive research on design, analysis and optimization of Tensairity beam grids in typical airship loading conditions is needed.
Effects of Common Breaching Practices on the Overpressures Recorded Within the Stack
Authors: Walilko Timothy J. 
Published: March 2015

The objective of this paper is to provide useful information to both military and law enforcement dynamic entry teams for estimating the level of protection provided by their standard protective equipment and procedures. The procedures investigated include: the K-Equation for predicting safe standoff, the effects of stack spacing, and the effect of the orientation of the stack within the blast field on the breachers’ blast exposure. This investigation leveraged both experimental data gathered during explosive breaching training exercises (Breacher Consortium, 2011 - draft) and numerical simulations using the shock physics code CTH (McGlaun, 1990).
The analysis revealed that the presence of objects within the blast range, including the other team members, significantly affected the individual’s exposure to the point that it sometimes exceeds current exposure recommendations. When each team member’s exposure was compared to the current limit of 4 psi (28 kPa), the average pressure from the gauges on the breacher helmets exceeded that level 43% of the time, and the averaged pressure at the shoulders exceeded the limit 50% of the time. In a comparison of the measured incident impulse energy to the maximum impulse energy predicted based on 4 psi peak pressure, the helmet impulse energy was exceeded 79% of the time and 64% of the time at the shoulders. Because the K-Equation was shown to be accurate in predicting the free-field pressure, these results and the output from the numerical simulations suggest that the stack and blanket do not provide the level of protection anticipated and that reducing the standoff distance, as prescribed by some protocols, is not justified.
Ultimately, the operational impact of these results will depend on efforts to identify blast exposure injury thresholds. Since there is a direct relationship between the peak overpressure and total impulse to which the breaching team members in the stack are exposed, injury thresholds must reveal which component, pressure, impulse or a combination is more injurious. Based on whether pressure or impulse must be minimized, the ideal stack configuration can be calculated using the developed numerical model.
Thread Reinforcement of Screw Connections in Lightweight Design
Authors: Hoernig T. , Friedrich C. 
Published: March 2015

Design engineers today desire to develop more lighter and compact components with higher performance capabilities against the background of saving resources. For this purpose, low strength and lightweight metals such Aluminum or Magnesium are preferred on one hand. On the other hand there is an increase in load requirements which needs higher clamp force between these components. In such applications length of thread engagement requires special focus. At the same time from industry perspective it is essential to have effective dimensioning methods to develop new products in shorter time and at a reasonable cost (economics).
Besides the increase in length of thread engagement, the tribology of mechanical contacts (i.e. increased friction coefficients and limited loading capacity due to higher contact pressure) plays an important role in the tightening process. The result is that the desired preload is often not achieved with a standardized tightening specification (reasons: high friction decreases preload for same tightening torque by high torsional stresses). In this contribution experimental results of tightening screws with nut components made from aluminum alloys are analyzed for their frictional behavior by using a multi-channel screw assembly test stand. Risks and dangers associated with tightening process are highlighted and suggestions are made for improvement in thread reinforcement.
An established method to realize thread reinforcement is using wired thread inserts. For these elements several standards concerning geometry and strength exist but no dimensioning method is available. These thread inserts themselves have a higher strength than the nut thread material and transmit the preload force of the screw with a greater surface area than the original nut component. This leads theoretically to an increase in the load capacity of the nut thread. The approach of existing dimensioning methods by established rules and regulations for the design of bolted connections, e.g. VDI 2230, are not able to predict the behavior of reinforced thread engagements. Hence, an extension for the dimensioning of threaded engagement is essential for modern requirements. Experiments of tightening screw joints with wired thread inserts and with normal thread engagement are comparatively analyzed along with numerical calculations using Finite Element Analysis (FEA).
Conclusions are drawn from experimental and FEA results with the perspective of formulating an extended dimensioning method for thread reinforcement of screw connections in lightweight design. These points are interesting for every design engineer, especially in the field of lightweight design.
Optimal Design and Aerodynamic Study of Leaned Transonic Axial Flow Fan Rotors
Authors: Razavi Seyed Reza , Boroomand Masoud 
Published: March 2015

Multi-Objective Optimization Problems (MOP) are very usual and complicated subjects in Turbomachinery and there are several methodologies for optimizing these problems. Genetic Algorithm (GA) and Artificial Neural Network (ANN) are the most popular ones to solve MOP. In this study, optimization was done for leaned rotor blades to achieve maximum performance parameters including specifically stage pressure ratio, efficiency and operating range.
By bending an existing transonic rotor which is well-known as NASA rotor-67 in tangential direction, effect of leaning on performance and aerodynamic parameters of transonic axial-flow compressor rotors was studied. To understand all effects of lean angle, an organized investigation including numerical simulation of basic rotor, implementation of curvatures on basic rotor, numerical simulation of leaned blades and optimization were applied. Various levels of lean angles were implemented to basic rotor and by employing a three dimensional compressible turbulent model, the operating parameters were achieved. Afterwards, the results were used as input data of optimization computer code.
Finally, the ANN optimization method was used to achieve maximum stage pressure ratio, efficiency and safe operating range. it was found that the Optimized leaned blades according to their target function had positive or negative optimized angles and the optimized lean angles effectively increased the safe operating range about 12% and simultaneously increase the pressure ratio and efficiency by 4% and 5%, respectively.
GPU‐accelerated regularized iterative reconstruction for few‐view cone beam CT
Authors: Matenine Dmitri , Goussard Yves , Després Philippe 
Published: March 2015

Purpose:The present work proposes an iterative reconstruction technique designed for x‐ray transmission computed tomography (CT). The main objective is to provide a model‐based solution to the cone‐beam CT reconstruction problem, yielding accurate low‐dose images via few‐views acquisitions in clinically acceptable time frames.Methods:The proposed technique combines a modified ordered subsets convex (OSC) algorithm and the total variation minimization (TV) regularization technique and is called OSC‐TV. The number of subsets of each OSC iteration follows a reduction pattern in order to ensure the best performance of the regularization method. Considering the high computational cost of the algorithm, it is implemented on a graphics processing unit, using parallelization to accelerate computations.Results:The reconstructions were performed on computer‐simulated as well as human pelvic cone‐beam CT projection data and image quality was assessed. In terms of convergence and image quality, OSC‐TV performs well in reconstruction of low‐dose cone‐beam CT data obtained via a few‐view acquisition protocol. It compares favorably to the few‐view TV‐regularized projections onto convex sets (POCS‐TV) algorithm. It also appears to be a viable alternative to full‐dataset filtered backprojection. Execution times are of 1–2 min and are compatible with the typical clinical workflow for nonreal‐time applications.Conclusions:Considering the image quality and execution times, this method may be useful for reconstruction of low‐dose clinical acquisitions. It may be of particular benefit to patients who undergo multiple acquisitions by reducing the overall imaging radiation dose and associated risks.
Genome Sequence of Acinetobacter baumannii Strain A1, an Early Example of Antibiotic-Resistant Global Clone 1
Authors: Holt Kathryn E. , Hamidian Mohammad , Kenyon Johanna J. , Wynn Matthew T. , Hawkey Jane , Pickard Derek , Hall Ruth M. 
Published: March 2015

ABSTRACT

Acinetobacter baumannii
isolate A1 was recovered in the United Kingdom in 1982 and belongs to global clone 1 (GC1). Here, we present its complete 3.91-Mbp genome sequence, generated via a combination of short-read sequencing (Illumina), long-read sequencing (PacBio), and manual finishing.
Draft Genome Sequence of Nocardia seriolae Strain N-2927 (NBRC 110360), Isolated as the Causal Agent of Nocardiosis of Yellowtail (Seriola quinqueradiata) in Kochi Prefecture, Japan
Authors: Imajoh Masayuki , Fukumoto Yoichi , Yamane Jin , Sukeda Masaki , Shimizu Masato , Ohnishi Kouhei , Oshima Syun-ichirou 
Published: March 2015

ABSTRACT

We report the draft genome sequence of
Nocardia seriolae
strain N-2927 (NBRC 110360), isolated from cultured yellowtail
Seriola quinqueradiata
. RAST annotation of the genome revealed 117 genes involved in the virulence, disease, and defense subsystem. Eleven of these genes were predicted as antibiotic resistance genes.
Draft Genome Sequence of Lactobacillus plantarum Lp90 Isolated from Wine
Authors: Lamontanara Antonella , Caggianiello Graziano , Orrù Luigi , Capozzi Vittorio , Michelotti Vania , Bayjanov Jumamurat R. , Renckens Bernadet , van Hijum Sacha A. F. T. , Cattivelli Luigi , Spano Giuseppe 
Published: March 2015

ABSTRACT

Here, we describe the draft genome sequence and annotation of
Lactobacillus plantarum
strain Lp90, the first sequenced genome of a L. plantarum strain isolated from wine. This strain has a noticeable ropy phenotype and showed potential probiotic properties. The genome consists of 3,324,076 bp (33 contigs) and contains 3,155 protein coding genes, 34 pseudogenes, and 84 RNA genes.
Draft Genome Sequences of Gammaproteobacterial Methanotrophs Isolated from Lake Washington Sediment
Authors: Kalyuzhnaya Marina G. , Lamb Andrew E. , McTaggart Tami L. , Oshkin Igor Y. , Shapiro Nicole , Woyke Tanja , Chistoserdova Ludmila 
Published: March 2015

ABSTRACT

The genomes of
Methylosarcina lacus
LW14
T
(=ATCC BAA-1047
T
= JCM 13284
T
), Methylobacter sp. strain 21/22, Methylobacter sp. strain 31/32, Methylomonas sp. strain LW13, Methylomonas sp. strain MK1, and Methylomonas sp. strain 11b were sequenced and are reported here. All the strains are obligately methanotrophic bacteria isolated from the sediment of Lake Washington.
Genome Sequences of Equid Herpesviruses 2 and 5
Authors: Wilkie Gavin S. , Kerr Karen , Stewart James P. , Studdert Michael J. , Davison Andrew J. 
Published: March 2015

ABSTRACT
We resequenced the genome of equid herpesvirus 2 (EHV2) strain 86/67 and sequenced the genomes of EHV2 strain G9/92 and equid herpesvirus 5 (EHV5) strain 2-141/67. The most prominent genetic differences are the dissimilar locations of the interleukin-10 (IL-10)-like genes and the presence of an OX-2-like gene in EHV5 only.
Targeting Nodal in Conjunction with Dacarbazine Induces Synergistic Anticancer Effects in Metastatic Melanoma
Authors: Hardy Katharine M. , Strizzi Luigi , Margaryan Naira V. , Gupta Kanika , Murphy George F. , Scolyer Richard A. , Hendrix Mary J.C. 
Published: March 2015

Abstract
Metastatic melanoma is a highly aggressive skin cancer with a poor prognosis. Despite a complete response in fewer than 5% of patients, the chemotherapeutic agent dacarbazine (DTIC) remains the reference drug after almost 40 years. More recently, FDA-approved drugs have shown promise but patient outcome remains modest, predominantly due to drug resistance. As such, combinatorial targeting has received increased attention, and will advance with the identification of new molecular targets. One attractive target for improving melanoma therapy is the growth factor Nodal, whose normal expression is largely restricted to embryonic development, but is reactivated in metastatic melanoma. In this study, we sought to determine how Nodal-positive human melanoma cells respond to DTIC treatment and to ascertain whether targeting Nodal in combination with DTIC would be more effective than monotherapy. A single treatment with DTIC inhibited cell growth but did not induce apoptosis. Rather than reducing Nodal expression, DTIC increased the size of the Nodal-positive subpopulation, an observation coincident with increased cellular invasion. Importantly, clinical tissue specimens from patients with melanomas refractory to DTIC therapy stained positive for Nodal expression, both in pre- and post-DTIC tumors, underscoring the value of targeting Nodal. In vitro, anti-Nodal antibodies alone had some adverse effects on proliferation and apoptosis, but combining DTIC treatment with anti-Nodal antibodies decreased cell growth and increased apoptosis synergistically, at concentrations incapable of producing meaningful effects as monotherapy.
Implications: Targeting Nodal in combination with DTIC therapy holds promise for the treatment of metastatic melanoma. Mol Cancer Res; 13(4); 670–80. ©2015 AACR.