bluuebunny/crossref_metadata_2025_split huggingface dataset:
Binary Black Hole Mergers from Young Massive and Open Clusters: Comparison to GWTC-2 Gravitational Wave Data
Authors: Fragione Giacomo , Banerjee Sambaran 
Published: June 2021

Abstract
Several astrophysical scenarios have been proposed to explain the origin of the population of binary black hole (BBH) mergers detected in gravitational waves by the LIGO/Virgo Collaboration. Among them, BBH mergers assembled dynamically in young massive and open clusters have been shown to produce merger rate densities consistent with LIGO/Virgo estimated rates. We use the results of a suite of direct, high-precision N-body evolutionary models of young massive and open clusters and build the population of BBH mergers, by accounting for both a cosmologically motivated model for the formation of young massive and open clusters and the detection probability of LIGO/Virgo. We show that our models produce dynamically paired BBH mergers that are well consistent with the observed masses, mass ratios, effective spin parameters, and final spins of the second Gravitational Wave Transient Catalog (GWTC-2).
One Is the Loneliest Number: Multiplicity in Cool Dwarfs
Authors: Cifuentes Carlos , Caballero José A. , Agustí Sergio 
Published: June 2021

Abstract
Stars in multiple systems offer a unique opportunity to learn about stellar formation and evolution. As they settle down into stable configurations, multiple systems occur in a variety of hierarchies and a wide range of separations between the components. We examine 11 known and 11 newly discovered multiple systems including at least one M dwarf with the latest astrometric data from Gaia Early Data Release 3 (EDR3). We find that the individual components of systems at very wide separations are often multiple systems themselves.
Higher Order Aberrations Comparison in Fellow Eyes Following IntraLase LASIK With WaveLight Allegretto and CustomCornea LADARVision4000 Systems
Authors: Tran Dan B , Shah Viraj 
Published: June 2021

ABSTRACT
PURPOSE: To compare the differences in objective and subjective visual outcomes with wavefront-optimized versus wavefront-guided excimer laser ablations using two different excimer laser platforms.
METHODS: In this prospective, randomized, matched, contralateral eye study, one eye was treated with the Alcon CustomCornea system, and the fellow eye was treated with the WaveLight Allegretto Wavefront-Optimized system. The IntraLase FS30 femtosecond laser was used to create all flaps. Treatments were randomized to the dominant eye, and optical treatment zones were matched to 6.5 mm. Patients were observed for 3 months after surgery. Initial data analysis was available for the first 28 eyes of 14 patients.
RESULTS: The only statistically significant differences between the groups were seen in the amount of higher order aberrations-the 14 eyes in the WaveLight group had a mean preoperative root-mean-square (RMS) error of 0.37 µm compared to 0.36 µm for 14 eyes in the Alcon group. Of the 8 patients who had 3-month follow-up, 8 eyes in the WaveLight group had a mean RMS error of 0.58 µm at 3 months, compared to 0.41 µm in the 8 eyes in the Alcon group.
CONCLUSIONS: Early results from this study have shown that both laser platforms produce accurate refractive outcomes; however, the Alcon CustomCornea LADARVision4000 system induces statistically significantly fewer higher order aberrations than the WaveLight Allegretto system. [J Refract Surg. 2006;22:S961-S964.]
Hydrogeological Characteristics of the Area of Intermittent Karst Lakes of Pivka
Authors: Petrič Metka , Kogovšek Janja 
Published: June 2021

Poseben hidrološki pojav zahodnega dela kraškega masiva Javornikov so presihajoča Pivška jezera. Za celotno območje je značilna tesna povezava podzemnih in površinskih voda. V kraškem vodonosniku se vode pretakajo večinoma podzemno, ob močnejših in dolgotrajnejših padavinah pa se nivo podzemne vode dvigne in voda se na številnih mestih preliva na površje. Tako postanejo aktivni občasni kraški izviri ob reki Pivki, z vodo pa se napolnijo tudi kraške depresije in nastane večje število presihajočih kraških jezer. Nekatera se pojavljajo dokaj pogosto in imajo vodo tudi do pol leta, večinoma pa so bolj redka ali so zalita samo izjemoma v času močnejših poplav. V članku so predstavljene hidrogeološke značilnosti območja, ki se odražajo v režimu pretakanja kraške vode in načinih njenega pojavljanja na površju. A special hydrological feature of the western part of the Javorniki karst massif is the intermittent karst lakes of Pivka. For the whole area a close connection between underground and surface water is characteristic. In the karst aquifer water flows mostly underground, but after more intensive or long-lasting precipitation the water table rises and water emerges on the surface at different locations. Intermittent karst springs along the Pivka river are activated. Also karst depressions are filled with water and several intermittent karst lakes can be formed. Some of them appear very often and contain water for up to six months, but mostly they are very rare and filled up only exceptionally in the time of big floods. In the article the hydrogeological characteristics of the area are presented, which are reflected in the flow regime of karst water and in the forms of its appearance on the surface.
Les malentendus liés à la réduction des risques en prison
Authors: Dos Santos Marie , Michel Laurent , Jauffret-Roustide Marie 
Published: June 2021

Cet article s’inscrit dans le cadre d’une recherche collective sur les malentendus liés à la mise en place d’outils de réduction des risques infectieux en prison. À partir d’une présentation du programme PRI2DE et des différentes étapes de l’enquête ethnographique menée au sein de la maison d’arrêt des Baumettes à Marseille, il examine la place accordée à la réduction des risques (RdR) en prison. Introduire des outils de RdR dans une prison suppose que soit reconnue l’existence de pratiques illicites (usages de drogues et sexualité) en son sein. Fondamentalement, la RdR se situe au croisement des missions, paradoxales, portées par l’institution carcérale : la mission de contrôle et la mission de réhabilitation.
Rendre les cancers évitables. Recherches sur le travail cancérogène et ses conséquences
Authors: Hunsmann Moritz , Thébaud-Mony Annie , Équipe du GISCOP  
Published: June 2021

Avec près de 400 000 nouveaux cas par an, la France est en pleine épidémie de cancer. Or, malgré la nature fortement inégalitaire de cette épidémie, le rôle du travail dans la survenue des cancers demeure peu ou pas pris en compte. Dans le cadre de l’enquête de cohorte du GISCOP 84 auprès de patients atteints de cancer hématologique pris en charge au centre hospitalier d’Avignon, chaque cancer est considéré comme un « événement-sentinelle » donnant accès aux expositions professionnelles aux cancérogènes subies par les patients, mais aussi aux freins et leviers d’action pour la reconnaissance en maladie professionnelle et la prévention. L’article présente cette démarche de recherche pour l’action et le type de connaissances qu’elle permet de produire, tout en analysant les résistances institutionnelles auxquelles elle se heurte. En effet, si la crise sanitaire majeure qu’est l’épidémie de cancers appelle des réponses fortes, la prévention des cancers professionnels est en prise directe avec les rapports sociaux de production – et donc politiquement sensible.
Reducing Intubation Time in Adult Cardiothoracic Surgery Patients With a Fast-track Extubation Protocol
Authors: Ellis Myra F. , Pena Heather , Cadavero Allen , Farrell Debra , Kettle Mollie , Kaatz Alexandra R. , Thomas Tonda , Granger Bradi , Ghadimi Kamrouz 
Published: June 2021

Background
Prolonged intubation after cardiac surgery increases the risk of morbidity and mortality and lengthens hospital stays. Factors that influence the ability to extubate patients with speed and efficiency include the operation, the patient’s baseline physiological condition, workflow processes, and provider practice patterns.

Local Problem
Progression to extubation lacked consistency and coordination across the team. The purpose of the project was to engage interprofessional stakeholders to reduce intubation times after cardiac surgery by implementing fast-track extubation and redesigned care processes.

Methods
This staged implementation study used the Define, Measure, Analyze, Improve, and Control approach to quality improvement. Barriers to extubation were identified and reduced through care redesign. A protocol-driven approach to extubation was also developed for the cardiothoracic intensive care unit. The team was engaged with clear goals and given progress updates.

Results
In the preimplementation cohort, early extubation was achieved in 48 of 101 patients (47.5%) who were designated for early extubation on admission to the cardiothoracic intensive care unit. Following implementation of a fast-track extubation protocol and improved care processes, 153 of 211 patients (72.5%) were extubated within 6 hours after cardiac surgery. Reintubation rate, length of stay, and 30-day mortality did not differ between cohorts.

Conclusions
The number of early extubations following cardiac surgery was successfully increased. Faster progression to extubation did not increase risk of reintubation or other adverse events. Using a framework that integrated personal, social, and environmental influences helped increase the impact of this project.
A NEURO FUZZY MODEL FOR THE INVESTIGATION OF DETERIORATION OF METALLIC PIPE CONVEYING FLUID UNDER DIFFERENT PIPE BURIAL DEPTH, SOIL TYPES AND PROPERTIES
Authors: Akano TT , Fakindele OA , Mgbemere HE , Amechi JC 
Published: June 2021

Several factors may contribute directly or indirectly to the structural failure of metallic pipes. The most important of which is corrosion. Corrosivity of pipes is not a directly measurable parameter as pipe corrosion is a very random phenomenon. The main aim of the present study is to develop a neuro-fuzzy model capable of establishing corrosion rate criterion as a function of pipe burial depth, soil types, and properties for the prediction of deterioration of metallic pipe conveying fluid. The proposed model includes a fuzzy model and the artificial neural network (ANN) to determine soil corrosivity potential (CoP) based on soil properties. The combination contains the data of linguistic variables characterising various soil properties, and learning capability of the system that constructs relationships among those soil properties and CoP. Subsequently, the artificial neuro-fuzzy inference system (ANFIS) maps each element of its input membership function to an output membership function between 0 and 1 to determine the deterioration rate (CoP) of metallic fluid-conveying-pipe. Field data from buried fluid pipes were examined to illustrate the application of the proposed model. The ultimate goal is the ability to access the current and future life of oil pipe, given a set of circumstances, and also appropriate adoptable methodology in view of a preventive maintenance measure for the pipes in a given operating environment. Results reveal that with more than 40% clay content quickens corrosion of buried fluid pipes more than any other considered factor. http://dx.doi.org/10.4314/njt.v36i1.10
MODELLING OF RESPONSES FROM ORTHOGONAL METAL CUTTING OF MILD STEEL USING CARBIDE INSERT TOOL
Authors: Onifade MK , Igboanugo AC , Osarenmwinda JO 
Published: June 2021

The purpose of this research was to develop models for the prediction of responses from orthogonal metal cutting process that are responsible for the machinability ratings of this technological system. Mild steel work-piece material that is representative sample for various industrial applications was machined. The various industrial applications of this representative sample range from mechanical shafts to fasteners, screws and hydraulic jack. These machine elements require high degree of surface finish. A fifteen-run based Box-Behnken response surface design was created using widely established machining parameters, namely cutting speed, feed rate and depth of cut. The optimum predicted responses from the orthogonal cutting process for the optimal process parameters are 0.1742 micron, 0.4933 micron, 0.1845 micron, 0.3673 micron, 794.6839 seconds and 19.642 seconds for the Ra, Rz, Rq, Rt, TL and M/C time respectively. The associated desirabilities for these optimum responses are 1.000000, 1.000000, 1.000000, 1.000000, 0.524122, and 0.361858 respectively. http://dx.doi.org/10.4314/njt.v36i1.13
PRELIMINARY MULTIDOMAIN MODELLING AND SIMULATION STUDY OF A HORIZONTAL AXIS WIND TURBINE (HAWT) TOWER VIBRATION
Authors: Iliyasu I , Iliyasu I , Tanimu IK , Obada DO 
Published: June 2021

Renewable energy sources have gained much attention due to the recent energy crisis and the urge to get clean energy. Among the main options being studied, wind energy is a strong contender because of its reliability due to the maturity of the technology, good infrastructure and relative cost competitiveness. It is also interesting to note that there are physical limits to the potential height of a wind turbine tower since the mechanical structure of wind turbines are thus very flexible and tend to oscillate. This makes the design of wind turbines a demanding task. In this paper, the oscillation of a wind turbine tower due to imbalance in the masses of the blades is modeled in maplesim and the effect of the tower height on its oscillation was simulated. For a wind turbine with three rotor blades, two of which have masses of 10 kg, a mass moment of inertia of approximately 20 kg/m2 and one of the blades has a moment of inertia which is 1% less than the other blades. The simulation showed the most stable system for the most energy capture for this case study to be a rotor speed of 5.5rad/s at a height of 10m. At this angular frequency the deflection of the top of the wind turbine was approximately 1mm. http://dx.doi.org/10.4314/njt.v36i1.16
AUTOMATIC GENERATION OF ROOT LOCUS PLOTS FOR LINEAR TIME INVARIANT SYSTEMS
Authors: Durutoye N , Ogunbiyi O 
Published: June 2021

Design and analysis of control systems often become difficult due to the complexity of the system model and the design techniques involved. This paper presents the development of a Tools Box in Microsoft Excel for control engineer that uses root locus as a time domain technique for system design and analysis. The Tool Box can also serve as a computer-aided graphical analytical tool for trainers. The work was done in two phases: the first phase is the development of a programmable algorithms for root locus using the angle condition and bisection method while the second phase is the implementation of the developed algorithms. The implementation was done using Microsoft Excel (R) Visual Basic Application (VBA). Results of simulations for different systems show the potential of the Tool Box as an alternative for other software package and the ease of using it on the readily available Microsoft Excel environment. http://dx.doi.org/10.4314/njt.v36i1.20
RECEIVE SIGNAL STRENGTH PREDICTION IN THE GSM BAND USING WAVELET DECOMPOSITION
Authors: Danladi A , Silika NW , Vasira PG 
Published: June 2021

In this work, GSM receive signal strength was monitored in an indoor environment. Samples of GSM receive signal strength was measured on a Mobile Equipment (ME). One-dimensional multilevel wavelet decomposition technique was used to predict the fading phenomenon of the GSM receive signal strength measured. Wavelet prediction revealed that the GSM receive signal strength is attenuated due to the slow fading phenomenon, which fades about 3 times faster than the radio wavelength. The prediction is further validated using probability density functions in terms of Gaussian and Rayleigh distributions. It is observed that, significant part of the signal strength measured is dominated by good signal (- 101 dBm to – 74 dBm) with an average of – 88.8842 dBm and the signal strength followed more of Gaussian than Rayleigh distribution. This confirmed the wavelet prediction. http://dx.doi.org/10.4314/njt.v36i1.22
VOLTAGE COMPENSATION USING ARTIFICIAL NEURAL NETWORK: A CASE STUDY OF RUMUOLA DISTRIBUTION NETWORK
Authors: Uhumnwangho R , Omorogiuwa E , Offor G 
Published: June 2021

A study of hourly voltage log taken over a period of six months from Rumuola Distribution network Port Harcourt, Rivers State indicates that power quality problems prevalent in the Network are undervoltage/voltage sags and overvoltage/voltage swells. This paper aims at addressing these power quality problems in the distribution network using artificial neural network (ANN) controller based dynamic voltage restorer (DVR). The artificial neural networks controller engaged to controlling the dynamic voltage restorer were trained with input and output data of proportional integral (PI) controller and of unit amplitude generator obtained during simulation. All simulations and modeling were carried out in MathLab/Simulink. Proposed dynamic voltage restorer was tested with replicated model of Rumuola substation by simulating with sample of average voltage for Omerelu, Waterlines, Rumuola, Shell Industrial and Barracks feeders. Simulation results showed that DVR is effective in compensating for under-voltage and over-voltage in Rumuola Distribution network Port Harcourt, Rivers State. http://dx.doi.org/10.4314/njt.v36i1.23
A RAPID HEALTH IMPACT ASSESSMENT OF THE UNIVERSITY OF ILORIN DAM
Authors: Bilewu SO , Ayanshola AM , Salami AW 
Published: June 2021

Many Dams have been constructed in different parts of the world and for different purposes. While these dams have in most cases served the reason for their construction, the resultant environmental impact have been a subject of concern. The creation of a reservoir not only changes the ecology and hydrology of the environment, the lives of nearby residents is also affected. This study assessed the impact of the University of Ilorin Dam on the health condition of the University community. The Dam was built for the main purpose of water supply to university community. Data on the water related disease reported and documented at the university clinic was obtained to cover pre and post construction period while the perception and behavioral pattern of the community as related to water and sanitation was studied with the help of a structured questionnaire. The chi-squared test was applied to establish that a relationship do exist between the dam construction and the occurrence of some diseases especially Malaria. The study have also shown that the dam imposes no significant negative health impact on the university community. http://dx.doi.org/10.4314/njt.v36i1.28
FREQUENCY ANALYSIS OF RAINFALL FOR FLOOD CONTROL IN PATANI, DELTA STATE OF NIGERIA
Authors: Okeke OB , Ehiorobo JO 
Published: June 2021

The Niger Delta Region of Nigeria is within the mangrove forest region and is crisscrossed by series of streams and creeks. As a result of the high rainfall volume within this region there is a tendency for severe flooding to occur. These flood events have severe consequences on lives and properties. It is therefore necessary to carry out a flood frequency analysis in this area in order to predict the potentials for the occurrence of flooding and take necessary measures for their remediation. In this study, peak monthly rainfall for thirty three years from 1981 – 2013 were acquired for Patani area in the Niger Delta region of Nigeria from NIMET and CBN. Five probability distributions, namely Normal, Log normal, Log-Pearson, Gumbel and Foster’s Type -1 were selected for frequency analysis of the precipitation data using return periods of 2, 5, 10, 25, 50, 100 and 200 years respectively. The predicted values were subjected to goodness of fit tests using ANFIS tool in the MATLAB 7.0 software. The results of the tests and analyses show that the Gumbel Distribution best describes the precipitation data for the region and can therefore be used for the prediction of flooding within the study area followed by the Foster’s Type- I distribution. The Normal Distribution was on the other hand found the least suitable for describing the precipitation data for Patani area. http://dx.doi.org/10.4314/njt.v36i1.34
DEVELOPMENT AND TESTING OF MULTI-LEVEL TEMPERATURE PROBE FOR UNDERWATER APPLICATION IN WETLAND SYSTEMS
Authors: Udom IJ , Mbajirogu CC , Daniyan I 
Published: June 2021

Temperature variation in wetland systems is of great importance. Temperature exerts a strong influence on chemical and biological processes leading to water quality treatment and is therefore important for wetland designers trying to both calculate accurate rates of treatment as well as optimize wetland systems for pollutant removal. Temperature fluctuations can result in thermal inversions. Temperature measurements are important for understanding hydrological and ecological processes in wetlands. Temperature measurements in underwater conditions is challenging in terms of cost and thorough insulation for optimal performance. This work presents the design and development of a water-resistant, adjustable multi-sensor temperature probe for underwater temperature measurement. It consists of three digital sensors DS18B20 interfaced with Atmega 328P microprocessor. The system is equipped with a 20×4 LCD display which displays up to three temperature profiles at varied depths. Validation of the instrument with the hand-held mercury-in-glass thermometer at different temperature regimes showed a +/- 0.5 accuracy within a temperature range of -10oC to +85oC. http://dx.doi.org/10.4314/njt.v36i1.38
OPTIMISATION OF COMPRESSIVE STRENGTH OF PERIWINKLE SHELL AGGREGATE CONCRETE
Authors: Egamana S , Sule S 
Published: June 2021

In this paper, a regression model is developed to predict and optimise the compressive strength of periwinkle shell aggregate concrete using Scheffe’s regression theory. The results obtained from the derived regression model agreed favourably with the experimental data. The model was tested for adequacy using a student t-test at 95% confidence level and was found to be adequate. A computer programme coded in basic language was used to select the mix ratios that optimized the compressive strength of periwinkle shell aggregate concrete. The optimum compressive strength was found to be 19.50N/mm2corresponding to a mix ratio of 1:3:6 (cement, sand and periwinkle shell) at a water-cement ratio of 0.65. With the formulated model, the mix ratios corresponding to a desired strength value can be predicted with reasonable accuracy and without waste of time. http://dx.doi.org/10.4314/njt.v36i1.5
DEVELOPED PROBABILISTIC REDUCTION FACTORS FOR LOPHIRA ALATA (EKKI) TIMBER JOISTS SUBJECTED TO CREEP-RUPTURE
Authors: Kaura JM , Lawan A , Salihu AA 
Published: June 2021

Wood experiences a significant loss of strength and stiffness when loaded over period of time. This phenomenon is known as creep-rupture. Several models were developed for the estimation of the reduction of load carrying capacity of timber with time. In this paper, the results of time dependent structural reliability analysis of timber joist produced with Lophiraalata (Ekki) timber specie was presented. Three load duration models were considered in the study, namely: The Model proposed by Wood, Gerhards model, and Nielsen. The timber joist was designed in accordance with the Eurocode 5. The uncertainties in all the basic design variables were fully accommodated in the time dependent reliability analysis. The entire process was implemented using a developed MATLAB program employing First Order Reliability Method (FORM). Time dependent mathematical models for modification of safety index to account for the effect of load duration were proposed. The use of both Gerhards and Nielsen model, for the design of Lophiraalata timber members was recommended. http://dx.doi.org/10.4314/njt.v36i1.6