bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of public debt on foreign direct investment in South Africa (1983-2013): An empirical analysis
Authors: Oche Mary Oyemowo , Mah Gisele , Mongale Itumeleng Pleasure
Published: January 2017

The political move in South Africa occurred against a setting of high government deficits. Efforts have been made over the years by the government to reduce fiscal deficit and inflation, liberalize the capital account and the financial system as well as reduce tariffs. The main objective of this study, therefore, is to empirically investigate the effect of public debt on foreign direct investment in South African for the period 1983 – 2013. The study employs a Vector Error Correction Model, which provides both the long run and short run relationships among the variables. The long run results indicate that the relationship between public debt and foreign direct investment, as well as interest rate and foreign direct investment, is positive and statistically significant, while there is an insignificant negative relationship between exchange rate and foreign direct investment. Based on the long run results, the study, thus, recommend that the level of public debt and interest rate should increase so that the level of foreign direct investment can increase in the country. However, the policy of depreciation of rand is considered inappropriate for the economy if the desire is to increase the level of foreign direct investment in the country.
Microwave assisted synthesis of substituted 4-chloro-8-methyl-2-(1,3-diphenyl-1H-pyrazol-4-yl)-1,5-dioxa-2H-phenanthren-6-ones and their antimicrobial activity
Authors: Ashok Dongamanti , Vanaja Reddy , Sarasija Mdderla , Lakshmi Vijaya
Published: January 2017

Due to the potential antimicrobial activity of pyranochromenones and
pyrazolines moieties, hybrid compounds containing both, substituted
4-Chloro-8-methyl-2-(1,3-diphenyl-
-1H-pyrazol-4-yl)-1,5-dioxa-2H-phenanthren-6-ones (4a-g), have been
synthesized from substituted
(E)-1-(7-Hydroxy-4-methyl-8-coumarinyl)-3-(1,3-diphenyl
-1H-pyrazol-4-yl)-2-propen-1-ones (3a-g) in good yield using the Vilsmeier
reaction, by microwave-assisted method. The structures of all the compounds
have been established on the basis of analytical and spectral data. All the
synthesized compounds were tested in vitro for their antibacterial and
antifungal activities. Some of the compounds have shown very good activity
compared to standard drugs against all pathogenic bacteria and fungi.
Globalization of consumer confidence
Authors: Çelik Sadullah , Deniz Pınar
Published: January 2017

The globalization of world economies and the importance of nowcasting analysis have been at the core of the recent literature. Nevertheless, these two strands of research are hardly coupled. This study aims to fill this gap through examining the globalization of the consumer confidence index (CCI) by applying conventional and unconventional econometric methods. The US CCI is used as the benchmark in tests of comovement among the CCIs of several developing and developed countries, with the data sets divided into three sub-periods: global liquidity abundance, the Great Recession, and postcrisis. The existence and/or degree of globalization of the CCIs vary according to the period, whereas globalization in the form of coherence and similar paths is observed only during the Great Recession and, surprisingly, stronger in developing/emerging countries.
La injuria como expresión de alteridad: blasfemias, reniegos y maldiciones de los judeoconversos judaizantes castellanos en el tránsito de la Edad Media a la Moderna
Authors: Montenegro Enrique Cantera
Published: January 2017

Este trabajo centra su atención en el estudio de las blasfemias, los reniegos y las maldiciones proferidas por judeoconversos judaizantes castellanos en el período de transición entre la Edad Media y la Moderna, y que son recogidas con detalle en numerosos procesos de la Inquisición. Un análisis detenido de estas expresiones permite adentrarse en el conocimiento del universo mental de los judeoconversos, en un tiempo especialmente convulso para ellos; un tiempo en el que podían sentir muy de cerca el acoso inquisitorial y en el que llegaba a su fin la presencia secular del judaísmo en suelo hispano. A través de la blasfemia, el reniego y la maldición, el judeoconverso judaizante hacía manifestación pública de sus sentimientos más íntimos, de su judaísmo larvado y de su rechazo del cristianismo y de la sociedad cristiana de la que, al menos en la teoría, formaba parte.
Ernest Renan 'brésilien': dos papéis que um historiador francês teve no Brasil
Authors: Rudi Thiago Augusto Modesto
Published: January 2017

O presente artigo busca narrar os papéis que Ernest Renan (1823-1892) teve no Brasil. Por meio do estudo de uma série de textos publicados no Brasil e que fizeram referência a esse historiador francês, narrar-se-á como se deu a construção de um “Renan brésilien”, especialmente a partir das repetidas referências, por escritores brasileiros, aos textos desse historiador dedicados à história das origens do cristianismo e à definição da nação. Simultaneamente, procuro dizer da centralidade da noção de “influência” para os estudos que avaliaram as leituras que brasileiros fizeram de Renan e, por fim, apresento trabalhos que, ao tomarem Renan e seus leitores como objetos de estudo, procuram tratar da historicidade das verdades partilhadas por esses escritos.
Getting to the Roots of Evaluation Capacity Building in the Global South: Multiple Streams Model to Frame the Agenda Status of Evaluation in Turkey
Authors: Cakici Hanife
Published: January 2017

Abstract: A growing body of research is investigating the mechanisms to develop evaluation capacity in the Global South, but relatively little attention has been given to an equally important question: Under what conditions does the need to conduct and use evaluations for national decision making become a high priority on the governmental agenda? This article utilizes Kingdon's (2003) Multiple Streams Model to understand when and how evaluation is pushed higher on the public policy agenda in the Global South by using Turkey as a country case. This article argues that evaluation capacity building in the developing world may not be successful unless evaluation is indigenously elevated as a prominent item on the government's agenda. Turkey's case demonstrates evaluation's fleeting agenda status because evaluation as a policy solution has not yet become joined to a real problem despite the opening of a brief window of opportunity.
Decolonizing and Indigenizing Evaluation Practice in Africa: Toward African Relational Evaluation Approaches
Authors: Chilisa Bagele , Major Thenjiwe Emily , Gaotlhobogwe Michael , Mokgolodi Hildah
Published: January 2017

Abstract: Efforts at making evaluation culturally relevant have become central to evaluation discourses globally. However, global attempts at culturally responsive practice have not succeeded in incorporating African voices. This article discusses African perspectives on decolonization and indigenization of evaluation. It further provides a description of an African relational evaluation paradigm as a basis for originating evaluation practices and theories rooted in African world views, and provides examples of evaluation studies that illustrate relational evaluation approaches. It makes claims for an African evaluation tree metaphor that features approaches to evaluation in Africa by African theorists.
A Cross-cultural Evaluation Conversation in India: Benefits, Challenges, and Lessons Learned
Authors: Hudib Hind Al , Cousins J. Bradley , Oza Jayshree , Lakshminarayana Undurthy , Bhat Vassant D.
Published: January 2017

Abstract: Through a guided discussion, this article explores a five-year cross-cultural evaluation relationship comprising multiple projects involving an evaluator from Canada and a group of Indian colleagues working on educational reform in India. The initiative was funded through a multilateral consortium of donors and involved Western evaluation specialists working in collaboration with Indian colleagues to (a) develop evaluation capacity within the country and (b) produce evaluative knowledge about education quality initiatives associated with large-scale educational reform. This article is based on a conversation between the principal investigator from Canada and three Indian colleagues who had been involved in all phases of the work. It focuses on their respective perspectives and experiences, including the benefits obtained and the challenges encountered in the process of bridging Western and Indian knowledge systems. The article begins with background about the initiative and continues with a conversation among the participants about their cross-cultural evaluation experience. It concludes with an analysis of the issues that emerged and generation of lessons learned for evaluators interested in cross-cultural evaluation.
Influence of casting skin on the fatigue lifetime of ferritic ductile cast iron
Authors: Rehmer Birgit , Skrotzki Birgit , Glaubitz Steffen
Published: January 2017

The fatigue behavior of cast iron is usually investigated on machined specimens. Components of cast iron, however, have a casting skin. Therefore, the investigation of the influence of the casting skin on the lifetime is of interest. To study this influence, isothermal fatigue tests were carried out on heat resisting spheroidal graphite cast iron EN GJS SiMo 4.05 in 4-point bending setup at 400 °C. Specimens with and without casting skin were investigated comparatively. The number of cycles to failure was significantly lower for specimens with casting skin. Metallographic investigations underline the reduction of lifetime caused by casting skin.
Evaluation of the Total Eyes-off-Road Time Glance Criterion in the NHTSA Visual-Manual Guidelines
Authors: Young Richard A.
Published: January 2017

NHTSA issued a 12-s total eyes-off-road time (TEORT) glance criterion for its visual-manual guidelines simulator test. This criterion relied on NHTSA’s analysis of manual radio-tuning data from its simulator study using a 2010 Toyota Prius premium radio and its test-track study of five 2005 to 2010 vehicles using various radio-tuning control types. However, this 12-s criterion was biased falsely downward. First, NHTSA oversampled the youngest participants (with the shortest TEORT scores) in the simulator study and oversampled the newest radios (with the shortest TEORT scores) in the test track study. Second, NHTSA incorrectly assumed that track and simulator metrics had a one-to-one correspondence, but the track TEORT was substantially shorter than the simulator TEORT for a matched Prius task with matched older participant ages. Third, NHTSA set its criterion at exactly the 85th percentile of the TEORT data rather than its upper confidence limit; hence, traditional radio-tuning tasks would fail repeated tests simply because of random test-to-test variation. The current study, after adjusting for these and other biases, estimated a criterion of 21.4 s from the identical NHTSA data sets. Emerging knowledge that relies on naturalistic driving studies suggests that cumulative glance metrics such as TEORT have low predictive validity for crashes compared with other metrics. A new test should be developed with metrics of higher predictive validity for relative crash risk on the basis of a growing scientific consensus about the relationship—both positive and negative—between eye glances, relative crash risk, and secondary task performance while driving.
When Do Drivers Abort an Overtaking Maneuver on Two-Lane Rural Roads?
Authors: Farah Haneen
Published: January 2017

Overtaking another vehicle on two-lane roads is a complex driving maneuver. Drivers who desire to overtake a vehicle have to evaluate the available gaps in the opposite direction and accept a sufficient gap to complete the overtaking maneuver successfully. However, drivers often realize that the gap that they have accepted is shorter than what they actually need to complete the maneuver safely and therefore decide to abort the overtaking maneuver. Research studies have focused mainly on analyzing drivers’ decisions to accept or reject available gaps in the opposite direction and their overtaking performance. Very limited research has investigated the conditions under which drivers decided to abort or complete an initiated overtaking maneuver. Increased frequency of aborted overtaking maneuvers has negative implications for safety and the operation of two-lane roads. One hundred drivers from both genders and different age groups participated in a driving simulator experiment study. Driving scenarios with different geometric and traffic characteristics were developed. Detailed trajectory data of 670 overtaking maneuvers were collected; 554 were successfully completed, and 116 were aborted. A logistic regression model was developed to predict the probability that a driver will abort an overtaking maneuver. The results show that the probability of aborting an overtaking maneuver is significantly affected by the size of the accepted gap in the opposite direction, the desired driving speed of the driver, the speed and type of the front lead vehicle, the cumulative waiting time to find an appropriate gap on the opposite direction, the road curvature, and the driver’s age and gender.
Gap Acceptance Behavior of Mobile Phone–Distracted Drivers at Roundabouts
Authors: Haque M. Mazharul , Oviedo-Trespalacios Oscar , Debnath Ashim Kumar , Washington Simon
Published: January 2017

The use of mobile phones while driving is increasing at an alarming rate despite the associated crash risks. A significant safety concern is that driving while distracted by a mobile phone is more prevalent among young drivers, a less experienced driving cohort with elevated crash risk. The objective of this study was to examine the gap acceptance behavior of distracted young drivers at roundabouts. The Center for Accident Research and Road Safety–Queensland Advanced Driving Simulator was used to test participants on a simulated gap acceptance scenario at roundabouts. Conflicting traffic approaching from the right of a four-legged roundabout was programmed to show a series of vehicles with the gaps between them proportionately increased from 2 s to 6 s. Thirty-two licensed young drivers drove the simulator under three phone conditions: baseline (no phone conversation), a hands-free phone conversation, and a handheld phone conversation. Results show that distracted drivers started responding to the gap acceptance scenario when they were closer to the roundabout and they approached the roundabout at slower speeds. These drivers also decelerated at faster rates to reduce their speeds before gap acceptance compared with nondistracted drivers. Although accepted gap sizes were not significantly different across phone conditions, differences in the safety margin at various gap sizes—measured by postencroachment time (PET) between the driven vehicle and the conflicting vehicle—were statistically significant across phone conditions. PETs for distracted drivers were smaller across different gap sizes and suggest that a smaller safety margin was accepted by distracted drivers compared with nondistracted drivers.
Operational Effects of Transverse Rumble Strips on Approaches to High-Speed Intersections
Authors: Yang Lingling , Zhou Huaguo , Zhu Lingxi , Qu Hongyang
Published: January 2017

The objective of this study was to determine whether the application of transverse rumble strips was an effective warning device for drivers approaching high-speed intersections. Performance was evaluated for attention-getting characteristics, driver speed choice, and braking behavior. Five intersection approaches on US-280 in Alabama were selected and monitored during both daytime and nighttime conditions. Acoustic and tactile signatures were measured by a specially equipped passenger car under different speed ranges. To examine effectiveness on speed changes, vehicle mean speeds were recorded by radar measurements along the approach to the intersections: 400 ft (122 m) upstream of the transverse rumble strips, right before the transverse rumble strips, and right after the transverse rumble strips. Video cameras were also in place to survey the brake lights of vehicles driving over the transverse rumble strips to quantify driver behavior. An analysis of variance F-test and Tukey’s honest significance test revealed that the strips created a recognizable amount of interior noise and vibration when an automobile crossed over the transverse rumble strips. The installation of transverse rumble strips generally produced statistically significant ( p ≤ .05) reductions in approach speeds. During daytime and at night, drivers drove at lower speeds through the intersections compared with the initial upstream speed. The transverse rumble strips also exerted certain effects on driver braking behavior.
Should Legacy Highway Advisory Radio and Citizens’ Band Radio Advisory Systems Be Continued?: Analysis of Traveler Usage and Satisfaction Regarding These Systems
Authors: Sandt Adrian , Al-Deek Haitham , Rogers John H. , Muhaisen Nabil , Alomari Ahmad
Published: January 2017

Advanced traveler information systems (ATIS) are important to provide travelers with accurate, up-to-date travel information. With the advent of new ATIS technologies, such as smartphone applications, roadway agencies need to understand how travelers use existing ATIS technologies, such as the legacy Highway Advisory Radio (HAR). The University of Central Florida implemented three traveler surveys and one truck driver survey to obtain the opinions of Florida roadway users regarding HAR, the Citizens’ Band Radio Advisory System (CBRAS), and other traffic information sources. Travelers typically preferred dynamic message signs (32%), smartphone applications (23%), and vehicle navigation devices (21%) for general traffic information. Some 57% of travelers were aware of HAR, and 42% of these travelers had used HAR, with 84% of users expressing satisfaction with HAR. Additionally, 87% of travelers said that they would use HAR during emergencies, such as hurricanes. A tree model targeting user satisfaction was developed; the model showed that HAR users who thought HAR should be continued, or who would use HAR in emergencies, as well as more frequent HAR users, were more likely to be satisfied. Only 12% of surveyed truck drivers had ever used CBRAS, but these users tended to utilize CBRAS frequently, and 92% indicated satisfaction with CBRAS. Truck drivers preferred vehicle navigation devices (28%) and smartphone applications (22%) to receive traffic information. Even though these surveys indicate that new technologies are more popular than HAR and CBRAS, these older systems satisfy users and should be kept for redundancy; cellular communications may fail during emergencies.
Validation of a Low-Cost Driving Simulator Based on Continuous Speed Profiles
Authors: Llopis-Castelló David , Camacho-Torregrosa Francisco Javier , Marín-Morales Javier , Pérez-Zuriaga Ana María , García Alfredo , Dols Juan F.
Published: January 2017

The number of road safety studies that are based on driving simulators is growing significantly. The Polytechnic University of Valencia, Spain, developed a low-cost driving simulator for the assessment, training, and rehabilitation of drivers (SE2RCO). The main objective of this research was the validation of the driving simulator so that studies about road safety and highway geometric design that considered human factors could be performed. The validation was based on continuous speed profiles collected from 28 volunteers on a 30-km-long, two-lane rural road section. The same volunteers drove through the same road section built in SE2RCO. Speed data of 79 curves and 52 tangents were selected for the analysis. Comparison of the real and simulated speeds ensured the simulator’s objective validity according to average and operating speeds. Two models were developed to predict field speeds from simulated speeds. Results showed that a simulated average speed lower than approximately 90 km/h was linked to a similar real average speed. For higher simulated speeds, the average speed in the real environment was lower than the simulated one. In addition, the actual operating speed was around 5 km/h lower than the operating speed in the driving simulator. Most volunteers assessed the quality and similarity of the virtual environment compared with the real world as medium or high and assessed the driving tasks similarly, thus achieving subjective validation of the simulator.
Minimum Time to Situation Awareness in Scenarios Involving Transfer of Control from an Automated Driving Suite
Authors: Samuel Siby , Borowsky Avinoam , Zilberstein Shlomo , Fisher Donald L.
Published: January 2017

This research assessed the impact of vehicle automation on a driver’s ability to anticipate latent threats and to detect materialized hazards on the forward roadway. In particular, the minimum alert time before transfer of control was determined. This was the minimum time required after an autonomous driving suite (ADS) had been in full control of a vehicle for the driver to reacquire the same level of situation awareness that he or she had when in full control of the vehicle. This simulator study included five treatment conditions during which drivers either were always in complete control of their own vehicle (control) or were required to resume control at 4 s, 6 s, 8 s, or 12 s before the appearance of a latent hazard (transfer). While the vehicle was in autonomous mode, the drivers performed an in-vehicle task for more than a minute and were told not to glance at the forward roadway. Analysis of eye movements showed that drivers in the control condition detected nearly 40% more hazards compared with drivers in the shortest transfer condition. The results indicated how long before control was transferred from the ADS back to a driver that the driver should be told that a transfer would occur, if the driver were to have full situation awareness. Unlike previous studies, this study both ensured that the driver was not watching for hazards while the ADS was in control and used a measure of situation awareness (hazard anticipation) that was closely linked to the actual understanding a driver had of the threats present in a given scenario.
Driving Simulation of the Safety and Operation Performance at a Freeway Toll Plaza
Authors: Valdés Didier , Colucci Benjamín , Fisher Donald L. , Ruiz Johnathan , Colón Enid , García Ricardo
Published: January 2017

Toll plaza designs have implemented electronic toll collection and other technologies to improve toll systems; however, an increase in crashes has appeared with these improvements. To study safely the pertinent aspects of driver behavior in toll plazas with electronic toll collection, a cockpit driving simulator housed at the University of Puerto Rico at Mayagüez was used. Specifically, in this study a comparison was made of two configurations of the signs that indicated the corresponding speed limit and toll station for each lane in the area before the toll plaza. One configuration corresponded to the current condition of the signage in Puerto Rico, with signs located at the roadside; the second configuration presented a proposed overhead signage treatment. A representative group of 20 subjects was selected to test the effectiveness of the two signage configurations on the approach zone leading to the toll plaza, calculating the standard deviation of roadway position, speed, and acceleration noise in five zones. The behavior of drivers using the proposed signage configuration appeared to be safer than the behavior of drivers following the current signage configuration. Specifically, at each of five zones in which behavior was sampled on the approach to the toll plaza, drivers using the proposed configuration changed lanes more smoothly and reduced their vehicles’ velocity more when approaching the toll plaza. Nevertheless, there was no significant difference between configurations in acceleration noise. The results of this study provide strong evidence that driving simulators can be used effectively to identify efficient and inexpensive alternative signage configurations at toll plazas.
Ein neuer Naturschutz für das Anthropozän (Essay)
Authors: Küffer Christoph
Published: January 2017

New nature conservation strategies for the Anthropocene (essay)

Nature conservation experiences a phase of vivid debates about its fundamental principles. The underlying basic question is: how can biodiversity be saved and major species extinction be avoided, when most of the planet is affected by human land use and anthropogenic environmental change including climate change? This implies three more specific questions: To what extent does a spatial separation of conservation areas and land use still work? When can nature disturbed by human still be restored to a pre-human state? How should novel species assemblies, and especially those composed of non-native species, be managed? I will in this article discuss current literature dealing with these three questions and propose a middle way between extreme positions, that neither solely relies on the principles of traditional nature conservation nor fully embraces novel anthropogenic nature.
Experimental and Numerical Investigation on Non-Newtonian Nanofluids Flowing in Shell Side of Helical Baffled Heat Exchanger Combined with Elliptic Tubes
Authors: Ling Ziye , He Zhenbin , Xu Tao , Fang Xiaoming , Gao Xuenong , Zhang Zhengguo
Published: January 2017

In this paper, an aqueous solution of xanthan gum (XG) at a weight fraction as high as 0.2% was elected as the non-Newtonian base liquid, the multi-walled carbon nanotubes (MWCNTs) dispersed into non-Newtonian XG aqueous at different weight factions of MWCNTs was prepared. Convection heat transfer of non-Newtonian nanofluids in the shell side of helical baffled heat exchanger combined with elliptic tubes has been investigated experimentally and numerically using single-phase flow model. Results showed that the enhancement of the convective heat transfer coefficient increases with an increase in the Reynolds number and the nanoparticle concentration. For nanofluids with 0.2 wt %, 0.5 wt % and 1.0 wt % MWCNTs, the Nusselt number, respectively, increases by 11%, 21% and 35% on average at the same Reynolds number, while the comprehensive thermal performance factors are 3%–5%, 15%–17% and 24%–26% higher than that of base fluid at the same volume rate. A remarkable heat transfer enhancement can be obtained by adding MWCNTs into XG aqueous solution based on thermal resistance analysis. Correlations have been suggested for the shell-side Nusselt number and friction factor of non-Newtonian nanofluids in the helical baffled heat exchanger with elliptic tubes. Good agreements existed between corrections and experimental data.
FTIR and Raman Characterization of TiO2 Nanoparticles Coated with Polyethylene Glycol as Carrier for 2-Methoxyestradiol
Authors: León Andrea , Reuquen Patricia , Garín Carolina , Segura Rodrigo , Vargas Patricio , Zapata Paula , Orihuela Pedro
Published: January 2017

The aim of this study was to prepare a novel targeting drug delivery system for 2-Methoxyestradiol (2ME) in order to improve the clinical application of this antitumor drug. It is based in nanoparticles (NPs) of titanium dioxide (TiO2) coated with polyethylene glycol (PEG) and loaded with 2ME. A complete IR and Raman characterization have been made to confirm the formation of TiO2–PEG–2ME composite. Vibrational modes have been assigned for TiO2, PEG, and 2ME and functionalized TiO2–PEG and TiO2–PEG–2ME. The observed variation in peak position of FTIR and Raman of each for these composites has been elucidated in terms of intermolecular interactions between PEG–2ME and TiO2, obtaining step-by-step the modification processes that were attributed to the conjugation of PEG and 2ME to TiO2 NPs. Modifying TiO2 NPs with PEG loaded with the 2ME drug revealed that the titanium dioxide nanocarrier possesses an effective adsorption capability, and we discuss their potential application as a system of drug delivery.
Taking a Stab at Cancer; Oncolytic Virus-Mediated Anti-Cancer Vaccination Strategies
Authors: Aitken Amelia , Roy Dominic , Bourgeois-Daigneault Marie-Claude
Published: January 2017

Vaccines have classically been used for disease prevention. Modern clinical vaccines are continuously being developed for both traditional use as well as for new applications. Typically thought of in terms of infectious disease control, vaccination approaches can alternatively be adapted as a cancer therapy. Vaccines targeting cancer antigens can be used to induce anti-tumour immunity and have demonstrated therapeutic efficacy both pre-clinically and clinically. Various approaches now exist and further establish the tremendous potential and adaptability of anti-cancer vaccination. Classical strategies include ex vivo-loaded immune cells, RNA- or DNA-based vaccines and tumour cell lysates. Recent oncolytic virus development has resulted in a surge of novel viruses engineered to induce powerful tumour-specific immune responses. In addition to their use as cancer vaccines, oncolytic viruses have the added benefit of being directly cytolytic to cancer cells and thus promote antigen recognition within a highly immune-stimulating tumour microenvironment. While oncolytic viruses are perfectly equipped for efficient immunization, this complicates their use upon previous exposure. Indeed, the host’s anti-viral counter-attacks often impair multiple-dosing regimens. In this review we will focus on the use of oncolytic viruses for anti-tumour vaccination. We will explore different strategies as well as ways to circumvent some of their limitations.
Drones—An Open Access Journal
Authors: Gonzalez-Aguilera Diego , Rodriguez-Gonzalvez Pablo
Published: January 2017

Since the beginning of aviation, unmanned aerial systems have been a challenge for scientists and engineers.
Multimodal Languaging as a Pedagogical Model—A Case Study of the Concept of Division in School Mathematics
Authors: Joutsenlahti Jorma , Kulju Pirjo
Published: January 2017

The purpose of this study is to present a multimodal languaging model for mathematics education. The model consists of mathematical symbolic language, a pictorial language, and a natural language. By applying this model, the objective was to study how 4th grade pupils (N = 21) understand the concept of division. The data was collected over six hours of teaching sessions, during which the pupils expressed their mathematical thinking mainly by writing and drawing. Their productions, as well as questionnaire after the process, were analyzed qualitatively. The results show that, in expressing the mathematical problem in verbal form, most of the students saw it as a division into parts. It was evident from the pupils’ texts and drawings that the mathematical expression of subtraction could be interpreted in three different ways. It was found that the pupils enjoyed using writing in the solution of word problems, and it is suggested that the use of different modes in expressing mathematical thinking may both strengthen the learning of mathematical concepts and support the evaluation of learning.
Effects of a Dual-Loop Exhaust Gas Recirculation System and Variable Nozzle Turbine Control on the Operating Parameters of an Automotive Diesel Engine
Authors: Zamboni Giorgio , Moggia Simone , Capobianco Massimo
Published: January 2017

Reduction of NOX emissions and fuel consumption are the main topics in engine development, forcing the adoption of complex techniques and components, whose interactions have to be clearly understood for proper and reliable operations and management of the whole system. The investigation presented in this paper aimed at the development of integrated control strategies of turbocharging, high pressure (HP) and low pressure (LP) exhaust gas recirculation (EGR) systems for better NOX emissions and fuel consumption, while analyzing their reciprocal influence and the resulting variations of engine quantities. The study was based on an extended experimental program in three part load engine operating conditions. In the paper a comparison of the behavior of the main engine sub-systems (intake and exhaust circuits, turbocharger turbine and compressor, HP and LP EGR loops) in a wide range of operating modes is presented and discussed, considering open and closed loop approaches for variable nozzle turbine (VNT) control, and showing how these affect engine performance and emissions. The potential of significant decrease in NOX emissions through the integration of HP and LP EGR was confirmed, while a proper VNT management allowed for improved fuel consumption level, if an open loop control scheme is followed. At higher engine speed and load, further actions have to be applied to compensate for observed soot emissions increase.
The Influence of Acoustic Field Induced by HRT on Oscillation Behavior of a Single Droplet
Authors: Ruan Can , Xing Fei , Huang Yue , Yu Xinyi , Zhang Jiacheng , Yao Yufeng
Published: January 2017

This paper presents an experimental and theoretical study on the effects of an acoustic field induced by Hartmann Resonance Tube (HRT) on droplet deformation behavior. The characteristics of the acoustic field generated by HRT are investigated. Results show that the acoustic frequency decreases with the increase of the resonator length, the sound pressure level (SPL) increases with the increase of nozzle pressure ratio (NPR), and it is also noted that increasing resonator length can cause SPL to decrease, which has rarely been reported in published literature. Further theoretical analysis reveals that the resonance frequency of a droplet has several modes, and when the acoustic frequency equals the droplet’s frequency, heightened droplet responses are observed with the maximum amplitude of the shape oscillation. The experimental results for different resonator cavity lengths, nozzle pressure ratios and droplet diameters confirm the non-linear nature of this problem, and this conclusion is in good agreement with theoretical analysis. Measurements by high speed camera have shown that the introduction of an acoustic field can greatly enhance droplet oscillation, which means with the use of an ultrasonic atomizer based on HRT, the quality of atomization and combustion can be highly improved.
Wireless DC Motor Drives with Selectability and Controllability
Authors: Jiang Chaoqiang , Chau K.T. , Liu Chunhua , Han Wei
Published: January 2017

This paper proposes and implements the concept of wireless DC motor drives, which can achieve the abilities of selective driving and controllable speed. Due to different resonant frequencies of the multiple energy receivers of the associated DC motor drives, the transmitter can be purposely tuned to the specified resonant frequency which matches with the specified receiver, hence driving the specified motor selectively. In the meantime, the burst fire control is used to regulate the operating speed of the motor working at the resonant frequency, hence retaining the maximum power transmission efficiency. Both finite element analysis and experimentation are given to verify the validity of the proposed wireless DC motor drive system. For exemplification, three different resonant frequencies, namely 60 kHz, 100 kHz and 140 kHz, are selected to energize three DC motors. Under the burst fire control method, the speed of each motor can be regulated separately and the wireless power transfer (WPT) system can achieve the measured power transmission efficiency of about 60%.
An Effect Analysis of Comprehensive Treatment of Groundwater Over-Exploitation in Cheng’an County, Hebei Province, China
Authors: Shao Weiwei , Zhou Jinjun , Liu Jiahong , Zhang Haixing , Wang Jianhua , Xiang Chenyao , Yang Guiyu , Tang Yun
Published: January 2017

The comprehensive treatment project of groundwater over-exploitation in Hebei Province has been implemented for more than a year, and the effect of exploitation restriction is in urgent need of evaluation. This paper deals with Cheng’an County of Hebei Province as the research subject. Based on collected hydro-meteorological, socioeconomic, groundwater, and other related data, together with typical regional experimental research, this study generates the effective precipitation–groundwater exploitation (P-W) curve and accompanying research methods, and calculates the quantity of groundwater exploitation restriction. It analyzes the target completion status of groundwater exploitation restriction through water conservancy measures and agricultural practices of the groundwater over-exploitation comprehensive treatment project that was implemented in Cheng’an County in 2014. The paper evaluates the treatment effect of groundwater over-exploitation, as well as provides technical support for the effect evaluation of groundwater exploitation restriction of agricultural irrigation in Cheng’an County and relevant areas.
A Multiple Reaction Modelling Framework for Microbial Electrochemical Technologies
Authors: Oyetunde Tolutola , Sarma Priyangshu , Ahmad Farrukh , Rodríguez Jorge
Published: January 2017

A mathematical model for the theoretical evaluation of microbial electrochemical technologies (METs) is presented that incorporates a detailed physico-chemical framework, includes multiple reactions (both at the electrodes and in the bulk phase) and involves a variety of microbial functional groups. The model is applied to two theoretical case studies: (i) A microbial electrolysis cell (MEC) for continuous anodic volatile fatty acids (VFA) oxidation and cathodic VFA reduction to alcohols, for which the theoretical system response to changes in applied voltage and VFA feed ratio (anode-to-cathode) as well as membrane type are investigated. This case involves multiple parallel electrode reactions in both anode and cathode compartments; (ii) A microbial fuel cell (MFC) for cathodic perchlorate reduction, in which the theoretical impact of feed flow rates and concentrations on the overall system performance are investigated. This case involves multiple electrode reactions in series in the cathode compartment. The model structure captures interactions between important system variables based on first principles and provides a platform for the dynamic description of METs involving electrode reactions both in parallel and in series and in both MFC and MEC configurations. Such a theoretical modelling approach, largely based on first principles, appears promising in the development and testing of MET control and optimization strategies.
Recent Update on the Role of Chinese Material Medica and Formulations in Diabetic Retinopathy
Authors: Vasant More Sandeep , Kim In-Su , Choi Dong-Kug
Published: January 2017

Diabetes mellitus is one of the most frequent endocrine disorders, affecting populations worldwide. Diabetic retinopathy (DR) is the most frequent microvascular complication of diabetes in patients aged 20 and over. Major complications of DR include intraocular neovascularization, inter-retinal edema, hemorrhage, exudates and microaneurysms. Therefore, timely medical attention and prevention are required. At present, laser-assisted therapy and other operational procedures are the most common treatment for DR. However, these treatments can cause retinal damage and scarring. Also, use of the majority of traditional medicines is not supported by clinical evidence. However, due to accumulating scientific evidence, traditional natural medications may assist in delaying or preventing the progression of DR. This review focuses on evidence for the role of traditional natural medicines and their mechanisms of action and pharmacological test results in relation to the progression of DR.
Effect of Two Different Multimicronutrient Supplements on Vitamin D Status in Women of Childbearing Age: A Randomized Trial
Authors: Pilz Stefan , Hahn Andreas , Schön Christiane , Wilhelm Manfred , Obeid Rima
Published: January 2017

The German Nutrition Society raised in 2012 the recommended daily vitamin D intake from 200 to 800 international units (IU) to achieve 25-hydroxyvitamin D (25(OH)D) levels of at least 50 nmol/L, even when endogenous vitamin D synthesis is minimal such as in winter. We aimed to evaluate this recommendation in women of childbearing age. This is a single-center, randomized, open trial conducted from 8 January to 9 May 2016 in Esslingen, Germany. We randomized 201 apparently healthy women to receive for 8 weeks a daily multimicronutrient supplement containing either 200 IU (n = 100) or 800 IU vitamin D3 (n = 101). Primary outcome measure was serum 25(OH)D. 196 participants completed the trial. Increases in 25(OH)D (median with interquartile range) from baseline to study end were 13.2 (5.9 to 20.7) nmol/L in the 200 IU group, and 35.8 (18.2 to 52.8) nmol/L in the 800 IU group (p < 0.001 for the between group difference). At study end, levels of ≥50 nmol/L were present in 70.4% of the 200 IU group and in 99% of the 800 IU group. Participants on hormonal contraceptives had higher baseline levels and a stronger increase in 25(OH)D. In conclusion, daily supplementation of 800 IU vitamin D3 during wintertime in Germany is sufficient to achieve a 25(OH)D level of at least 50 nmol/L in almost all women of childbearing age, whereas 200 IU are insufficient.
Enhance the Quality of Crowdsensing for Fine-Grained Urban Environment Monitoring via Data Correlation
Authors: Kang Xu , Liu Liang , Ma Huadong
Published: January 2017

Monitoring the status of urban environments, which provides fundamental information for a city, yields crucial insights into various fields of urban research. Recently, with the popularity of smartphones and vehicles equipped with onboard sensors, a people-centric scheme, namely “crowdsensing”, for city-scale environment monitoring is emerging. This paper proposes a data correlation based crowdsensing approach for fine-grained urban environment monitoring. To demonstrate urban status, we generate sensing images via crowdsensing network, and then enhance the quality of sensing images via data correlation. Specifically, to achieve a higher quality of sensing images, we not only utilize temporal correlation of mobile sensing nodes but also fuse the sensory data with correlated environment data by introducing a collective tensor decomposition approach. Finally, we conduct a series of numerical simulations and a real dataset based case study. The results validate that our approach outperforms the traditional spatial interpolation-based method.
Poly(ethylene glycol)s as grinding additives in the mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins
Authors: Mascitti Andrea , Lupacchini Massimiliano , Guerra Ruben , Taydakov Ilya , Tonucci Lucia , d’Alessandro Nicola , Lamaty Frederic , Martinez Jean , Colacino Evelina
Published: January 2017

The mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins was investigated in the presence of various poly(ethylene) glycols (PEGs), as safe grinding assisting agents (liquid-assisted grinding, LAG). A comparative study under dry-grinding conditions was also performed. The results showed that the cyclization reaction was influenced by the amount of the PEG grinding agents. In general, cleaner reaction profiles were observed in the presence of PEGs, compared to dry-grinding procedures.
MASSIVE GALAXIES ARE LARGER IN DENSE ENVIRONMENTS: ENVIRONMENTAL DEPENDENCE OF MASS–SIZE RELATION OF EARLY-TYPE GALAXIES
Authors: Yoon Yongmin , Im Myungshin , Kim Jae-Woo
Published: January 2017

Under the Λ cold dark matter (ΛCDM) cosmological models, massive galaxies are expected to be larger in denser environments through frequent hierarchical mergers with other galaxies. Yet, observational studies of low-redshift early-type galaxies have shown no such trend, standing as a puzzle to solve during the past decade. We analyzed 73,116 early-type galaxies at 0.1 ≤ z < 0.15, adopting a robust nonparametric size measurement technique and extending the analysis to many massive galaxies. We find for the first time that local early-type galaxies heavier than 1011.2
M
⊙ show a clear environmental dependence in mass–size relation, in such a way that galaxies are as much as 20%–40% larger in the densest environments than in underdense environments. Splitting the sample into the brightest cluster galaxies (BCGs) and non-BCGs does not affect the result. This result agrees with the ΛCDM cosmological simulations and suggests that mergers played a significant role in the growth of massive galaxies in dense environments as expected in theory.
REVISITING STUDIES OF THE STATISTICAL PROPERTY OF A STRONG GRAVITATIONAL LENS SYSTEM AND MODEL-INDEPENDENT CONSTRAINT ON THE CURVATURE OF THE UNIVERSE
Authors: Xia Jun-Qing , Yu Hai , Wang Guo-Jian , Tian Shu-Xun , Li Zheng-Xiang , Cao Shuo , Zhu Zong-Hong
Published: January 2017

In this paper, we use a recently compiled data set, which comprises 118 galactic-scale strong gravitational lensing (SGL) systems to constrain the statistical property of the SGL system as well as the curvature of the universe without assuming any fiducial cosmological model. Based on the singular isothermal ellipsoid (SIE) model of the SGL system, we obtain that the constrained curvature parameter

is close to zero from the SGL data, which is consistent with the latest result of Planck measurement. More interestingly, we find that the parameter f in the SIE model is strongly correlated with the curvature

. Neglecting this correlation in the analysis will significantly overestimate the constraining power of SGL data on the curvature. Furthermore, the obtained constraint on f is different from previous results:

(68% confidence level [C.L.]), which means that the standard singular isothermal sphere (SIS) model (f = 1) is disfavored by the current SGL data at more than a

C.L. We also divide all of the SGL data into two parts according to the centric stellar velocity dispersion

and find that the larger the value of

for the subsample, the more favored the standard SIS model is. Finally, we extend the SIE model by assuming the power-law density profiles for the total mass density,

, and luminosity density,

, and obtain the constraints on the power-law indices:

and

at a 68% C.L. When assuming the power-law index

, this scenario is totally disfavored by the current SGL data,

.
DUSTiNGS. III. DISTRIBUTION OF INTERMEDIATE-AGE AND OLD STELLAR POPULATIONS IN DISKS AND OUTER EXTREMITIES OF DWARF GALAXIES
Authors: McQuinn Kristen B. W. , Boyer Martha L. , Mitchell Mallory B. , Skillman Evan D. , Gehrz R. D. , Groenewegen Martin A. T. , McDonald Iain , Sloan G. C. , Loon Jacco Th. van , Whitelock Patricia A. , Zijlstra Albert A.
Published: January 2017

We have traced the spatial distributions of intermediate-age and old stars in nine dwarf galaxies in the distant parts of the Local Group, using multi-epoch 3.6 and 4.5 μm data from the DUST in Nearby Galaxies with Spitzer (DUSTiNGS) survey. Using complementary optical imaging from the Hubble Space Telescope, we identify the tip of the red giant branch (TRGB) in the 3.6 μm photometry, separating thermally pulsating asymptotic giant branch stars from the larger red giant branch populations. Unlike the constant TRGB in the I band, at 3.6 μm, the TRGB magnitude varies by ∼0.7 mag, making it unreliable as a distance indicator. The intermediate-age and old stars are well mixed in two-thirds of the sample, with no evidence of a gradient in the ratio of the intermediate-age to old stellar populations outside the central ∼1′–2′. Variable AGB stars are detected in the outer extremities of the galaxies, indicating that chemical enrichment from these dust-producing stars may occur in the outer regions of galaxies with some frequency. Theories of structure formation in dwarf galaxies must account for the lack of radial gradients in intermediate-age populations and the presence of these stars in the outer extremities of dwarfs. Finally, we identify unique features in individual galaxies, such as extended tidal features in Sex A and Sag DIG and a central concentration of AGB stars in the inner regions of NGC 185 and NGC 147.