bluuebunny/crossref_metadata_2025_split huggingface dataset:
Weighted Modified Weibull Distribution
Authors: Khan Muhammad Nauman , Saeed Anwaar , Alzaatreh Ayman 
Published: October 2018

Abstract
A profusion of new classes of distributions has recently showed its usefulness to applied statisticians working in various areas of studies. Generalizing existing distributions by adding extra parameters to an existing family of distribution functions leads to more flexible models. In this article, we define a new three-parameter lifetime model called the weighted modified Weibull distribution. Various statistical properties of the distribution are derived. The estimation of parameters is discussed by using the method of maximum likelihood. Finally, the superiority of the proposed distribution is shown by analyzing four well-known lifetime datasets.
Experimental Study of Nonpolar Surfactant Mixed with Dielectric Fluid on Die-Sinking EDM of Ti-6Al-4V Alloy
Authors: Kolli Murahari , Kumar Adepu 
Published: October 2018

Abstract
This article deals with the study of the effect of nonpolar surfactant on the performance characteristics of Electrical Discharge Machining (EDM) of the Ti-6Al-4V alloy. The selected process parameters, like pulse on-time, pulse off-time, discharge current, and nonpolar surfactant concentration, and their effect on machining performance characteristics, like Thermal Conductivity (TC), Material Removal Rate (MRR), Surface Roughness (SR), Tool Wear Rate (TWR), and Recast Layer Thickness (RLT), were studied. In this article, the one-factor-at-a-time approach and Taguchi technique were used to determine the machining process parameters. Nonpolar surfactant is mixed into dielectric fluid, which increases the TC and suspends the debris particles in EDM oil to reduce the discontinued discharge conditions during machining. It was observed from the results that RLT, SR, and TWR are reduced, while MRR and TC are increased, compared to machining without nonpolar surfactant. Furthermore, the experimental results indicated that the surfactant was decomposed in EDM oil and that a small recast layer, which could be seen on migrated elements in EDX analysis peaks, formed on the machined surface.
Centrifuge Tests on the Lateral Behavior of Offshore Monopile in Saturated Dense Sand under Cyclic Loading
Authors: Lee Myungjae , Yoo Mintaek , Bae Kyungtae , Kim Youseok , Nam Boo Hyun , Youn Heejung 
Published: October 2018

Abstract
In this study, the cyclic lateral behaviors of an offshore monopile in saturated dense sand under cyclic loading was investigated using centrifuge model tests. The soil used for testing was Jumunjin sand, which was deposited with a relative density of 80 %. A static loading test was carried out to obtain the static lateral capacity of the monopile, from which the magnitudes of cyclic load were determined at 30 %, 50 %, 80 %, and 120 % of the lateral capacity. A hundred cycles were applied to the pile head with the frequency of 0.125 Hz. Experimental cyclic p-y curves were obtained at 2, 5, and 7-m depths, from which equations for cyclic p-y curves for saturated dense sand were proposed. The proposed p-y curve was compared with the conventional p-y curves; it was found that the proposed equations overestimate the ultimate soil resistance compared with the conventional ones, whereas the initial modulus of subgrade reaction was only 35 % the conventional ones.
A Novel Dynamic Detection Method of Impact Factor Considering Deterioration of Pavement Roughness
Authors: Liu Chen Guang , Wang Zong Lin , Gao Qing Fei , Sun Yong 
Published: October 2018

Abstract
The influence mechanism between the impact factor of bridge and pavement roughness was analyzed and a novel bridge dynamic detection method was presented in this article. Based on the vehicle-bridge vibration theory, the effect of both the spatial and frequency domain characters of pavement roughness on the impact factor were analyzed. Then, derived from the probability distribution model of the impact factor data, a new index for the dynamic increment that was excited by the pavement roughness was introduced. The new index can indicate the impact factors caused by the pavement roughness of different Power Spectral Density grades with selected assurance factors. Lastly, together with the new index, a novel dynamic detection method, which was developed from the obstacle moving truck testing method, was proposed. With a new equivalent design method, the dynamic increment excited by the artificial obstacles could be set similar to that which was caused by different degrees of pavement deterioration. The future dynamic response of the bridge could be predicted.
Finite Element Model Updating and Dynamic Analysis of a Restored Historical Timber Mosque Based on Ambient Vibration Tests
Authors: Altunişik Ahmet Can , Karahasan Olguhan Şevket , Okur Fatih Yesevi , Kalkan Ebru , Ozgan Korhan 
Published: October 2018

Abstract
The use of timber as a construction material is based on much older dates than concrete and steel. Therefore, the preservation of historical timber structures such as bridges, monuments, towers, mosques, etc. is very important for cultural heritage. The perspective of preservation for this kind of structures has been developed and has gained more importance in the last two decades. However, there are some issues that need to be addressed. Timber is an anisotropic material and is not fire resistant. Also, moisture causes significant swelling. So, structural behavior should be carefully evaluated by experimental techniques before and after restoration and verified numerically using finite element models. This article presents a detailed study on the structural condition assessment of a restored historical timber mosque: its finite element analysis (FEA), ambient vibration tests, model updating to minimize the differences and reflect the current situation, and dynamic analyses before and after updating procedure. The Kuşluca historical timber mosque located in the Sürmene District of Trabzon, Turkey was selected as an application. The mosque was built in the early 20th century and includes two floors. Significant timber decorative elements are available in the entrance door, minbar, and mihrab. The restoration projects began in 2008, and the restored mosque was opened in 2011. Finite element modeling of the mosque was accomplished using SAP2000 software (Computers and Structures, Inc., Walnut Creek, California), considering the restoration project drawings. Modal analysis was performed using orthotropic material properties, considering literature review, to determine the initial dynamic characteristics. Nondestructive experimental measurements were conducted after construction to validate the numerical results using in situ testing. Ambient vibration-based system identification was employed using the Enhanced Frequency Domain Decomposition method in the frequency domain and Stochastic Subspace Identification method in the time domain. The first three natural frequencies were obtained between 5.160 Hz to 7.153 Hz and 3.960 Hz to 5.873 Hz numerically and experimentally, respectively. There is close agreement between mode shapes, but 30.0 % differences in natural frequencies. To minimize the differences, the finite element model of the timber mosque is updated using the manual model updating procedures, with a changing of material properties to reflect the real structural behavior. The maximum differences are reduced to below the acceptable limits as 5 %. To evaluate the structural behavior and determine the model updating effect, linear dynamic-time history analyses are performed, and displacements with internal forces are compared to each other.
Evolution from Cooling Modeling to Cooling Engineering of the Steel Quenching Process: A Technology Overview
Authors: Luo Xinmin , Totten George E. 
Published: October 2018

AbstractThe type of heat treatment process used is mainly determined by its cooling mode. Hardening is a metal heat treatment during which the most critical operation is cooling. Most quenchants used for steel hardening are vaporizable liquids, such as water, petroleum oils, emulsions, aqueous polymer solutions, or brines. Testing methodologies that include ISO 9950, Industrial Quenching Oils-determination of Cooling Characteristics-Nickel-alloy Probe Test Method, and ASTM Standards: D6200, Standard Test Method for Determination of Cooling Characteristics of Quench Oils by Cooling Curve Analysis, D6482, Standard Test Method for Determination of Cooling Characteristics of Aqueous Polymer Quenchants by Cooling Curve Analysis with Agitation (Tensi Method), D6549, Standard Test Method for Determination of Cooling Characteristics of Quenchants by Cooling Curve Analysis with Agitation (Drayton Unit), and D7646, Standard Test Method for Determination of Cooling Characteristics of Aqueous Polymer Quenchants for Aluminum Alloys by Cooling Curve Analysis, are typically used to evaluate the cooling characteristics of these quenchants or processes. The cooling time–temperature curves obtained by these methodologies traditionally involve three stages of cooling. However, the relationship between this model and heat treatment, especially between hardening theory and practice, has not been satisfactory. Therefore, it is necessary to better understand the relationship between cooling theory and metallurgical behavior to create a new cooling model that achieves zero distortion, zero dispersion of quality, and zero pollution, which are concepts proposed in the “Heat Treating Industry Vision 2020 “and the “Heat Treating Technology Roadmap 2004” by the ASM Heat Treating Society and Materials Treating Institute. The relationship between the physical metallurgical phenomenon of phase transformation of a steel workpiece during quenching after being austenitized and the actual cooling conditions in engineering practice were analyzed and discussed in this report. Additionally, the development of advanced cooling technologies and related quenching equipment are discussed. The evolution from cooling model research to cooling engineering construction represents important progress in heat treatment practice.
Mathematical Modeling of the Thermal Response of Laboratory-Scale Probes
Authors: Hernández-Morales B. , Cruces-Reséndez R. , Vergara-Hernández H. J. 
Published: October 2018

AbstractExperiments for cooling curve analysis of laboratory-scale quenched probes produce a wetting front that advances at a finite velocity along the longitudinal axis of the probe as cooling progresses. The wetting front velocity depends on probe material and geometry as well as the type of quenchant, its temperature, and agitation. Because of the wetting front, the mathematical model of the direct heat conduction problem to compute the evolution of the thermal field within the probe may be characterized as a moving front boundary problem. In this work, cooling curves at three subsurface locations along the length of conical-end cylindrical probes, fabricated with AISI 304 stainless steel, during quenching from 850°C with water at 60°C flowing parallel to the probe’s longitudinal axis were measured. A fourth thermocouple located at the geometrical center of the probe was used to validate the model. Two values of free-stream water velocity (0.2 and 0.6 m/s) were studied. As a first approximation, the measured cooling curves were used to estimate the corresponding surface heat flux histories by solving three separate 1-D inverse heat conduction problems. Then, the thermal field evolution within the probe was computed by solving a 2-D axis-symmetrical heat transfer model. The boundary condition at the probe surface was modeled with a composite mapping of the surface heat flux histories. The surface heat flux history estimated for the lower section of the cylindrical part of the probe was applied as a boundary condition for the probe tip. It was found that the cooling curve at the lowest thermocouple position was overestimated; thus, the surface heat flux history for the probe tip was divided by 1.2 to correctly model the thermal response. The model was successfully validated by comparing measured and computed cooling curves for the thermocouple located at the probe’s geometrical center.
First detection of efrAB, an ABC multidrug efflux pump in Enterococcus faecalis in Tehran, Iran
Authors: Shiadeh Seyedeh Marzieh Jabbari , Hashemi Ali , Fallah Fatemeh , Lak Parnian , Azimi Leila , Rashidan Marjan 
Published: October 2018

Enterococcus faecalis is one of the most significant pathogen in both nosocomial and community-acquired infections. Reduced susceptibility to antibiotics is in part due to efflux pumps. This study was conducted on 80 isolates of E. faecalis isolated from outpatients with urinary tract infection during a period of 1 year from April 2014 to April 2015. The antibiotic susceptibility patterns of isolates were determined by the disk diffusion method and presence of efrA and efrB genes was detected by PCR and sequencing. Minimum inhibitory concentrations (MICs) to ciprofloxacin (CIP) were measured with and without carbonyl cyanide 3-chlorophenylhydrazone (CCCP) by broth microdilution. The highest resistance rate was observed to erythromycin (83.3%) and the prevalence of efrA and efrB genes in all E. faecalis isolates was 100%. This study showed that 9 out of 13 (69.2%) ciprofloxacin-resistant isolates became less resistant at least fourfolds to CIP in the presence of efflux pump inhibitor. Our result showed that CCCP as an efflux inhibitor can increase effect of CIP as an efficient antibiotic and it is suggested that efrAB efflux pumps are involved in resistance to fluoroquinolone.
Association of specific viral infections with childhood asthma exacerbations
Authors: Hassanzad Maryam , Nadji Seyed Alireza , Darougar Sepideh , Tashayoie-Nejad Sabereh , Boloursaz Mohammad Reza , Mahdaviani Seyed Alireza , Baghaie Nooshin , Ghaffaripour Hosseinali , Velayati Ali Akbar 
Published: October 2018

Introduction
Asthma exacerbations may occur due to a variety of triggers including respiratory viruses. The aim of this study was to determine the role of particular viral infections in asthma exacerbations in children.

Materials and methods
The study was performed at Dr. Daneshvari Hospital Pediatric Emergency Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran between 2014 and 2015. A nasopharyngeal aspirate or swab was obtained from each patient during admission. All samples were maintained at 4 °C until submission to the virology laboratory and were tested for respiratory viruses by nucleic acid testing.

Results
A total of 60 patients with asthma exacerbations were recruited for this study. Of the 60 samples collected from the patients with acute asthma exacerbations, rhinovirus was detected in 12 patients (20%), respiratory syncytial virus in 5 (8%), adenovirus in 5 (8%), and influenza virus in 1 (1.6%). Respiratory pathogens were not detected in 37 (61%) samples. All the samples investigated showed single viral infection.

Conclusions
To conclude, the most common viruses detected were rhinovirus followed by respiratory syncytial virus (RSV) and adenovirus. RSV was more commonly associated with more severe attacks. Both the study design (e.g., time of sampling, age of the patients, etc.) and also the method used for viral detection influence the frequency of detection of the respiratory viruses.
Experience of thyroid surgery at tertiary referral centers in Jazan Hospitals, Saudi Arabia
Authors: Alharbi Fahd , Ahmed Mohammed Rifaat 
Published: October 2018

Background
Benign multinodular goiter (BMNG) is a common disease of the thyroid gland with palpable thyroid nodules that may be detected in 0.8%–1.5% of men and 5.3%–6.4% of women. Three major complications could be detected after total thyroidectomy: hemorrhage, recurrent laryngeal paralysis, and hypoparathyroidism.

Aims
The aim of this study was to review and assess the experience of total thyroidectomy in patients with BMNG at tertiary referral centers in Jazan Hospitals, Saudi Arabia.

Methods
A retrospective study was conducted on 320 patients diagnosed with BMNG and subjected to primary total thyroidectomy. Operative mortality and major complications [bleeding, recurrent laryngeal nerve (RLN) injury, and hypoparathyroidism] were recorded.

Results
Postoperative hemorrhage was reported in four patients (1.25%). Bilateral RLN injuries occurred in two patients (0.6%), whereas unilateral RLN injuries occurred in nine patients (2.8%). Permanent hypoparathyroidism was diagnosed in three patients (0.9%), while transient hypoparathyroidism occurred in eight patients (2.5%) and improved after 4 months.

Conclusions
Total thyroidectomy represents today the treatment of choice for BMNG. Proper preoperative preparations, meticulous surgical dissection with careful follow-up of patients will improve the surgical results and reduce postoperative complications.
Online social networking addiction and depression: The results from a large-scale prospective cohort study in Chinese adolescents
Authors: Li Ji-Bin , Mo Phoenix K. H. , Lau Joseph T. F. , Su Xue-Fen , Zhang Xi , Wu Anise M. S. , Mai Jin-Cheng , Chen Yu-Xia 
Published: October 2018

Background and aims
The aim of this study is to estimate the longitudinal associations between online social networking addiction (OSNA) and depression, whether OSNA predicts development of depression, and reversely, whether depression predicts development of OSNA.

Methods
A total of 5,365 students from nine secondary schools in Guangzhou, Southern China were surveyed at baseline in March 2014, and followed up 9 months later. Level of OSNA and depression were measured using the validated OSNA scale and CES-D, respectively. Multilevel logistic regression models were applied to estimate the longitudinal associations between OSNA and depression.

Results
Adolescents who were depressed but free of OSNA at baseline had 1.48 times more likely to develop OSNA at follow-up compared with those non-depressed at baseline [adjusted OR (AOR): 1.48, 95% confidence interval (CI): 1.14–1.93]. In addition, compared with those who were not depressed during the follow-up period, adolescents who were persistently depressed or emerging depressed during the follow-up period had increased risk of developing OSNA at follow-up (AOR: 3.45, 95% CI: 2.51–4.75 for persistent depression; AOR: 4.47, 95% CI: 3.33–5.99 for emerging depression). Reversely, among those without depression at baseline, adolescents who were classified as persistent OSNA or emerging OSNA had higher risk of developing depression compared with those who were no OSNA (AOR: 1.65, 95% CI: 1.01–2.69 for persistent OSNA; AOR: 4.29; 95% CI: 3.17–5.81 for emerging OSNA).

Conclusion
The findings indicate a bidirectional association between OSNA and depression, meaning that addictive online social networking use is accompanied by increased level of depressive symptoms.
Sleepiness and impulsivity: Findings in non-treatment seeking young adults
Authors: Grant Jon E. , Chamberlain Samuel R. 
Published: October 2018

Background and aims
Although inadequate sleep has been linked to problematic behaviors, such as poor impulse control and emotion dysregulation, little research interest has been the role of sleep and sleep deprivation on impulsive behaviors in young adults. To further examine the relationship of sleepiness to impulsivity and impulsive behaviors, this study was designed to collect data on sleepiness, and a range of impulse control disorders and cognitive measures.

Methods
Young non-treatment-seeking adults were recruited from two US cities and completed a screening form for sleepiness, along with demographic, clinical, and cognitive measures relevant to impulsivity. Relationships between these explanatory variables and total sleepiness scores were analyzed using partial least squares. Significant explanatory variables were identified (p < .05, bootstrap).

Results
Higher levels of sleepiness were significantly associated with higher ADHD symptoms, gambling disorder symptoms, Internet addiction symptoms, and personality-related impulsiveness. Sleepiness was also associated with set-shifting errors, and with gambling more points (abnormal decision-making), but not with significant impairment in response to inhibition, or other aspects of decision-making.

Conclusions
This study confirms a cross-sectional relationship between sleepiness and a range of impulsive measures at the level of behavior (ADHD, gambling, and Internet addiction) and personality traits. Longitudinal research would be required to explore causal mechanisms and the direction of any such effects. Screening for such mental health diagnoses in people with sleep problems may be valuable, as enquiring patients with such impulsive symptoms about sleep, in order to maximize quality of life.
May the passion be with you: The addictive potential of collectible card games, miniatures, and dice of the Star Wars universe
Authors: Calvo Fran , Carbonell Xavier , Oberst Ursula , Fuster Héctor 
Published: October 2018

Background and aimsIn recent years, we have witnessed a growing research interest in behavioral addictions and in pleasurable behaviors that generate a certain discomfort in the people who engage in them. The objective of this study was to assess if users of collectible card games, miniatures, and dice from the Star Wars Universe Games (SWUG) may also present criteria of addiction and if the presence of these criteria is related to demographic variables, game-playing habits, and other variables.MethodsSWUG players were contacted through specialized gaming chats, and 218 of them completed the Internet Gaming Disorder Scale – Short Form (IGDS-SF9), a scale that assesses motivation to engage in the game (Massively Multiplayer Online Motivations Scale), the Rosenberg Self-Esteem Questionnaire, the Diener Satisfaction with Life Scale, and a question for the self-assessment of addiction.ResultsSignificant predictors of addictive symptoms were the motivation to seek dissociation and (negatively) self-esteem. Users more significantly dedicate indirect hours to the game (thinking about the game, preparing material, etc.) than to actually playing. No participant could be considered pathologically addicted, as no one scored above the tentative cut-off point of the IGDS-SF9.Discussion and conclusionsDespite the fact that many players considered themselves “addicted” and some presented various economic and family problems related to their activity, it was found that playing these games could not be equated to true addictive behavior, since no player had scores above the cut-off point. This finding contributes to current discussions about the tendency to overestimate excessive pleasurable behaviors.