bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Pseudomonas sp. growth in culture medium using electrical impedance spectroscopy with two bipolar geometries
Authors: Aranzazu-Osorio J E , Alzate L H 
Published: September 2019

Abstract
The electrical properties of microbial culture have been studied by electrical impedance spectroscopy. Electrochemical changes in microbial systems are facilitated by the metabolic and proteolytic action of microorganisms. In this study, the growth of isolated bacteria compatible with genus Pseudomonas was evaluated by direct technique using electrical impedance spectroscopy with two electrode geometries. In these experiments a minimal salts medium with glucose as the energy source was used. The data of electrical parameters were correlated by counting viable cells using cetrimide agar. Cell growth in the culture medium was increased in capacitance, clearly describing the exponential phase of bacterial growth. The correlation of the viable cell count compared with the capacitance showed a high Pearson coefficient (>0.9). The bacterial growth can be estimated in culture medium using electrical parameters, such as capacitance using parallel plates electrode and parallel circuit equations.
Effect of the electrode surface on the tetrapolar impedance measurements of Hela Cells in suspension
Authors: Pinto S M , Pinzon E F , Corzo S P , Miranda D A 
Published: September 2019

Abstract
Electrical impedance spectroscopy (EIS) measurements with four electrodes is widely used in the study of electrical properties of cells in suspension. Under less than ideal conditions, this set up enables the removal the surface polarization effects. However, in the case of HeLa cells in suspension, we noted that the electrical impedance spectra reproducibility is affected by the impurities and ionic species adsorbed on the electrode surface. We studied the influence of the electrode’s surface conditions on the EIS measurements of HeLa cells in suspension. EIS spectra were obtained before and after submitting the electrodes to a cleaning process. Chronopotentiometry and open circuit potential (OCP) measurements were carried out to verify the electrode’s surface conditions. The main effect of cleaning the electrodes was to decrease the standard deviation of the EIS data (On average, 3.42? to 0.70? for PBS and 17.22? to 0.31? for PBS with HeLa cells). OCP measurements evidenced surface differences between the cleaned and uncleaned electrodes. In addition, the chronopotentiometric curve obtained for the gold electrode/PBS system showed the adsorption of chloride and phosphate ions and other species existing in PBS on the electrode surface at 0.28 V and 0.53 V. Results suggest that the adsorbed species on the electrode surface led to an electrostatic build-up, which has a non-passive behavior.
Gene-sensor on the basis of bioimpedance measurements assisted with nanotechnology: an instrumentation proposal
Authors: Ames G , Laguna D U , Sánchez V , Sacristán E , González C A 
Published: September 2019

Abstract
In this study, we propose basic instrumentation for a new gene-sensor based on Polymerase Chain Reaction (PCR) product and its multifrequency bioimpedance relative measurements assisted with nanotechnology. The instrumentation proposal is split into four basic blocks: A) Control. - The fundament is a microcontroller (µC) for wide bandwidth current excitation, as well as data acquisition and registration. B) Digital Synthesizer. - A wide bandwidth digital synthesizer will provide a sinusoidal excitation current. C) Bioimpedance measurement.- this section will detect relative multifrequency bioimpedance by comparison of a reference signal with the signal of the Analyte Under Test (AUT). Comparison is on the basis of magnitude ratio and phase shift. D) Electrical-Ionic Interphase. – This is based on gold electrodes in contact with the AUT for current injection and relative bioimpedance measurements. Deoxyribonucleic Acid (DNA) fragments as PCR products will be functionalized by magnetic nanoparticles-DNA biding and its magnetic DNA insulation. The specific electronic components for every section are out of the range of this study, and the general instrumentation structure proposed is intended to show tentative low cost technology for gene detection and obtain academic discussion and feedback.
A Class of Weighted Point Schemes for the Grünwald Implicit Finite Difference Solution of Time-Fractional Parabolic Equations Using KSOR method
Authors: Muhiddin F A , Sulaiman J , Sunarto A 
Published: September 2019

Abstract
In this study, system of Grünwald implicit approximation equations has been developed through the discretization of one-dimensional linear time-fractional parabolic equations using the Grünwald fractional derivative operator and second-order implicit finite difference scheme. The aim of this paper is to examine the effectiveness of Kaudd Successive Over-Relaxation (KSOR) iterative method, which is one of the weighted point iterative schemes for solving the proposed time-fractional parabolic equations by considering the Grünwald implicit approximation equation. To investigate the effectiveness of the proposed iterative method, numerical experiments and comparison are made in terms of number of iterations, execution time, and maximum absolute error. Based on numerical results, the accuracy of Grünwald implicit solution obtained by proposed iterative method is in excellent agreement, and it can be concluded that the proposed KSOR iterative method requires less number of iterations and execution time as compared to the existing point iterative method.
Newton Method with AOR Iteration for Finding Large Scale Unconstrained Minimizer with Tridiagonal Hessian Matrices
Authors: Ghazali K , Sulaiman J , Dasril Y , Gabda D 
Published: September 2019

Abstract
Finding the large scale unconstrained minimizer using Newton method has required the calculation of large and complicated linear systems results from solving the Newton direction. Therefore, in this paper, we propose a method for solving large scale unconstrained optimization problems with tridiagonal Hessian matrices to reduce the complexity of calculating Newton direction. Our proposed method was a combination of Newton method and Accelerated Over Relaxation (AOR) iterative method. To evaluate the performance of the proposed method, combination of Newton method with Gauss-Seidel iteration and Newton method with Successive Over Relaxation (SOR) iteration were used as reference method. Finally, the numerical experiment illustrated that the proposed method produce results that are more efficient compared to the reference methods with less execution time and minimum number of iterations.
Delay-induced stability switches in an SIRS epidemic model with saturated incidence rate and temporary immunity
Authors: Pasion A M , Collera J A 
Published: September 2019

Abstract
This work considers a time-delayed SIRS epidemic model with temporary immunity and nonlinear incidence rate, where the susceptible host population satisfies the logistic equation and the incidence rate is of saturated form with the susceptible. The time delay represents a period of temporary immunity where disease-recovered individuals return to the susceptible class after a fixed period of time. By analyzing the associated characteristic equation with delay-dependent coefficients and regarding the time lag as the bifurcation parameter, the local stability of the endemic equilibrium is investigated and sufficient conditions for the occurrence of stability switches via Hopf bifurcations are obtained. It is shown that the delay parameter can induce a finite number of stability switches before completely destabilizing the system. Numerical simulations are carried out to illustrate theoretical results.
Differences between English and Chinese in the Implementation of the RSA algorithm
Authors: Jiang Duoji , Yankson Kwame 
Published: September 2019

Abstract
In this paper, we explore the implementation of RSA Public Key Cryptography in both English and Chinese. We begin by examining the history of ancient and modern cryptography, public key cryptography, the key distribution problem and how the RSA algorithm solves the key distribution problem. We then show how the RSA algorithm works in practice, on both English and Chinese characters, words and sentences. We end with a comparison of differences in implementation between the two languages.
An Analysis on the Formation of Solar Radio Burst Type II, III and IV by Using e-CALLISTO, IUGONET and Space Weather Data
Authors: Norsham N A M , Hamidi Z S 
Published: September 2019

Abstract
The study of the radio solar burst data on 30th March 2018 and 31st March 2018 are essential for the understanding of type II, type III and type IV nature. Through this paper, the relationship of these three types of solar radio burst can be studied. The necessary data were collected from the free online websites which includes the Space Weather Website, e-CALLISTO and IUGONET metadata database. From this study, the occurrence of solar radio burst type II, III, and IV showed that there was the production of solar flares and Coronal Mass Ejections (CMEs) where it contributed to the geomagnetic disturbances to the Earth. On 30th March 2018, the Sun produced C-class flares with C4 value while the next day, the sun had B1 solar flares’ event. The planetary K-index for both days were 2 (30th March 2018) and 3 (31st March 2018) respectively.
Design of the control law of longitudinal attitude for Tail-sitter UAV
Authors: Ge Zhilei , Hou Jiabao 
Published: September 2019

Abstract
The longitudinal attitude control of a type of Tail-sitter UAV is studied in this paper. In order to solve the singular problem of pitch angle during the tilting process of fuselage, the double Euler angle algorithm is used for modeling. Fuzzy self-tuning PID control method and L1 adaptive control method are used to design the longitudinal attitude controller respectively to counteract the susceptibility to disturbance during the flight, especially in tilting process. The numerical simulation is carried out through MATLAB, and the simulation results show that: This controller can overcome the model parameter changes and other uncertain disturbances to the Tail-sitter UAV during the flight
Simulation of fire development in a large-area shopping hall
Authors: Maslak M , Pazdanowski M , Wozniczka P 
Published: September 2019

Abstract
The results obtained after numerical simulation of fire development in a large area shopping hall are presented and widely discussed. The analysis has been conducted for two types of halls differing in size and efficient ventilation capabilities. A fire development scenario has been forecast under the assumption that a sufficient number of smoke vents had been installed as required by the provisions of law. The obtained results have been related to the hypothetical case where there were no smoke vents whatsoever. The stacking height of the merchandise gathered in the hall has been differentiated during the analysis as well. The numerical simulations have been performed with application of the FDS computer program. It has been assumed, that the fire had been initiated by a single source uniquely defined and initially limited in spatial area of influence. The results obtained indicate that the spatial and temporal fire development is different for each of the considered scenarios. The key role of the possible limitations in the exchange of gases between the area affected by fire and the environment, influencing the way and speed with which the fire propagates, has been confirmed during analysis.
Thermal performance of insulated glazing units established by infrared thermography
Authors: Moga L 
Published: September 2019

Abstract
The targets for the building sector have been clearly defined starting with the Directive 2010/31/UE and ending with the long term strategy that implies the decarbonisation of the entire building sector. The aim consists in designing nearly Zero Energy Buildings (nZEB) starting from 2019 for public buildings and 2021 for all new buildings. For the energy retrofit of existing buildings, the last Directive 2018/844/UE on the energy performance of buildings sets a clear target for reaching nZEB also in the retrofit activity. Although that clear targets exists on a European level, some buildings are still poorly designed from the thermal point of view and are not able to meet these criteria. Thus, in many cases the thermal performance obtained in the design activity is not the one obtain in the operation phase of a building. That is why, not even buildings built after 2010, do not comply with the minimum recommended national thermal design criteria, and therefore need to be thermally retrofitted. Thus, the paper presents a thermography study done at a residential buildings, respectively the examination of the thermal performance of part of a façade. The focus is placed on a window-wall area that is examined by Infrared Thermography. The resulted thermograms are reconstructed by means of artificial intelligence in order to establish the thermal performance of the examined façade and building envelope components.
Comparison of current stiffness modulus values in national and international literature
Authors: Iftode V-I , Olteanu-Dontov I , Mihai P , Budescu M , Sococol I , Dinu I-D 
Published: September 2019

Abstract
The paper objective is to realize a comparative synthesis of the current coefficients used to reduce the stiffness modulus. For this, national and international codes were considered as well as reference papers on the subject. In the end, the paper presents a case study in which behaviour differences were observed for a reinforced concrete frame structure between national and international codes.
Comparative Analysis of Hygrothermal Behaviour of the Exterior Walls in Transient Regime
Authors: Pescaru R A , Dumitrescu L , Baran I , Grădinaru C M 
Published: September 2019

Abstract
Energy conservation and an intelligent use of resources are among primary objectives in the contemporary society. The decrease of energy consumption in buildings has many benefits both on operating costs and environment preservation too. During the buildings life-cycle, the energy consumption for operation, in winter through heating and in summer through ventilation, is more important than the energy used in the construction phase, requiring passive measures from the design stage. The paper presents the results of a study of the behaviour, in a variable regime, of the external wall with different structures, to the mass transfer and temperature variations. The influence of the placement of interior or exterior thermal insulation layers on the hygrothermal behaviour of the envelope element was determined by means of WUFI® Pro software, which takes into account the built-in moisture, driving rain, solar radiation, long-wave radiation, capillary transport, and summer condensation.
Parametric study in composite joints configuration
Authors: Pop M , Campian C , Chira N 
Published: September 2019

Abstract
Composite structures showed higher stiffness than steel structures with similar ductility and also better performance to fire action. The global behaviour of the composite steel-concrete structure depends mostly on the behaviour of the joints. Many studies have demonstrated that composite joints exhibit adequate mechanical properties, such as strength, ductility and energy dissipation. The present paper is based on the study of the behaviour of the joints and their influence on the structure. The study involves a sensitivity analysis in the finite element program Abaqus 6.13. The analysis focuses on determining the parameters that significantly contributed both on the strength and stiffness of the joints and quantifying their weight in the final results. The analyses also provide information on the ductility of the connections under monotonic loads.
Simulation on implementing noise mitigation measures in a typical urban area
Authors: Oancea I , Covatariu G 
Published: September 2019

Abstract
Starting from the analysis of a real situation in which the equivalent noise level was measured in a residential area, an urban area with the same characteristics was simulated. The purpose of these tests was not to determine exactly the noise level in the area, but to simulate the introduction of noise mitigation measures, and to highlight the difference between the noise level at the edge of the sidewalk and the level next to the building, at the pedestrian height. Four series of simulations were made. The first series starts from the simple situation (street with 4 traffic bands and tram line), without measures of noise reduction, for which a green area with a height of 1.50 m was implemented, a noise barrier and then both measures. The second series of simulations tests the impact that the reduced capacity of the traffic in the area may have, transforming the street into one with only two traffic bands, the remaining space being given to the sidewalk. To optimize noise mitigation, the same situations were simulated, but with the implementation of a green area of 3.00m height. Thus, it is found that the noise level decreases from 74-76 dB (A) to 58-60 dB (A), meaning a decrease of 16 dB (A). From these simulations it can be concluded that in order to reach a comfortable noise level that respects the maximum admitted level, it is recommended to decrease traffic intensity (through different interventions on road surface capacity, promoting of public transport, etc.), to implement anti-noise barriers of materials with a high sound absorption capacity and a green space with a height that exceeds the height of the anti-noise barrier and has a high density of leaves.
A simple and rapid approach for the numerical simulation of non-linear elements and examples of its application
Authors: Loo W , Tuleasca L 
Published: September 2019

Abstract
In earthquake design philosophy non-linear inelastic damage is concentrated at predetermined locations in a structure, with the aim being to keep structural members critical for collapse avoidance, elastic. Non-linear elements can include the beam column joints in steel and reinforced concrete moment resisting frames, the nail connections of timber sheathing-to-framing shear walls, and the hold-down connectors of shear walls. To numerically model the seismic behaviour of these structures, it is critical to be able to quickly and simply model their respective hysteretic behaviours. It is particularly important to identify the parameters that will allow for the accurate replication of the degrading and pinching qualities of the force-displacement relationships. The authors summarise the use of a proprietary multi-linear plastic link, available in most finite element packages, in order to achieve this. A step-by-step process to model the links, from previous research, is described. This process considers the initial elastic stiffness, the force-displacement curve up to ultimate-strength, the post ultimate-strength degrading stiffness, and the reversing stiffness. The procedure can be adopted for both linear and rotational cyclic excitation. The modelled individual elements are subjected to a series of displacement-controlled time-history schedules and validated against the results from experimental tests. These elements, representing non-linear behaviour, are in turn implemented in various numerical models of shear walls. The authors apply cyclic loading to a model wall, and then for a separately designed wall apply seismic ground accelerations associated with the 2011 Canterbury earthquakes in New Zealand, and the results are presented. While the examples provided in this paper involve timber shear walls, the numerical modelling method will be equally useful for a variety of structures of different material types and configuration.
Study of the interface behaviour between fictile tubules bricks and mortar: numerical and experimental analysis
Authors: Scuro C , Tiberti S , Porzio S , Olivito R S , Milani G 
Published: September 2019

Abstract
This paper presents an investigation on the interaction between hollow clay bricks (caroselli) and mortar, aiming at obtaining frictional properties needed for a full description of the composite masonry material derived from these two constituents. A series of three-point bending tests is carried out on prism-shaped specimens representing typical arrangements of caroselli within mortar. Since no building code or guideline exists regulating this kind of tests, the specimens are built respecting the 1÷4 ratio between the transversal dimension and the length of the prism requested for mortar specimens subjected to three-point bending tests. The frictional properties of the interaction between the two constitutive materials are then derived through a series of back analyses concerning four different hypotheses on the actual degree of transmission of tangential stresses between caroselli and mortar. The numerical analyses are performed with the commercial finite element software ABAQUS. The obtained results sustain the experimental findings.
Interlaminar damage numerical modelling based on delamination growth of multi-layered composites
Authors: Hudișteanu I , Țăranu N , Isopescu D N , Munteanu V , Neculai O , Ungureanu D 
Published: September 2019

Abstract
A growing interest is nowadays directed towards the numerical modelling and monitoring of the interlaminar damage evolution of composite laminates, but also to the numerical mathematical models and techniques for simulation of the interface delamination. Modelling and investigation of the mechanical behaviour and fracture modes of the multi-layered composites is a complex issue, since other important parameters, such as fibre orientation angles, stacking sequences and configuration of the composite laminates are added to the anisotropic character of the composite materials. Different failure modes may occur on multi-layered composites, while the delamination type fracture may lead to a considerable decrease of the load carrying capacity of the composite structures. Interlaminar stresses, which occur in composite laminates as an effect of the presence of the free edges, have a major influence on the delamination onset and the delamination growth. The paper summarizes the numerical methods and the approaches considered in the simulation of the delamination growth of composite laminates. The obtained results are figured in terms of the opening displacement at the interface crack tip and stress distributions on the plies of the multi-layered composites.
Stability Analysis of a Scaled-Down Cold-Formed Steel Structure
Authors: Țăranu G , Bunea G , Olteanu-Donțov I , Venghiac V M , Ovidiu Toma I 
Published: September 2019

Abstract
The use of cold-formed steel CFS in building design has increased in the last period due to the numerous advantages it brings. However, there are relatively few research works on the behaviour of these types of structures to different loadings, especially compared to the hot-rolled steel structures. Unlike the hot-rolled steel elements, the CFS elements are prone to buckling failure. This paper investigates the stability of a scaled-down CFS structure considering the Eurocode EC and the American International Building Code IBC. First a comparison is done between the two codes in what concerns the stability analysis based on the theoretical aspects. Then, the results from the finite element program are presented, for both EC and IBC, and compared.