bluuebunny/crossref_metadata_2025 huggingface dataset:
On the topology of the spaces of curvature constrained plane curves
Authors: Ayala José
Published: July 2017

Plane curves with the same endpoints are homotopic; an analogous claim for plane curves with the same endpoints and bounded curvature still remains open. We find necessary and sufficient conditions for two plane curves with bounded curvature to be deformed into each other by a continuous one-parameter family of curves also having bounded curvature. We conclude that the space of these curves has either one or two connected components, depending on the distance between the endpoints. The classification theorem presented here answers a question raised in 1961 by L. E. Dubins.
A flag representation of projection functions
Authors: Goodey Paul , Hinderer Wolfram , Hug Daniel , Rataj Jan , Weil Wolfgang
Published: July 2017

The kth projection function υk
(K, ·) of a convex body K ⊂ ℝ
d
, d ≥ 3, is a function on the Grassmannian G(d, k) which measures the k-dimensional volume of the projection of K onto members of G(d, k). For k = 1 and k = d − 1, simple formulas for the projection functions exist. In particular, υ

d-1(K, ·) can be written as a spherical integral with respect to the surface area measure of K. Here, we generalize this result and prove two integral representations for υk
(K, ·), k = 1,..., d − 1, over flag manifolds. Whereas the first representation generalizes a result of Ambartzumian (1987), but uses a flag measure which is not continuous in K, the second representation is related to a recent flag formula for mixed volumes by Hug, Rataj and Weil (2013) and depends continuously on K.
Classification of 3-dimensional left-invariant almost paracontact metric structures
Authors: Calvaruso Giovanni , Perrone Antonella
Published: July 2017

We study left-invariant almost paracontact metric structures on arbitrary three-dimensional Lorentzian Lie groups. We obtain a complete classification and description under a natural assumption, which includes relevant classes as normal and almost para-cosymplectic structures, and we investigate geometric properties of these structures.
Silurian stratigraphy of Central Iran – an update
Authors: Hairapetian Vachik , Pour Mansoureh Ghobadi , Popov Leonid E. , Männik Peep , Miller C. Giles
Published: July 2017

The Silurian biostratigraphy, lithostratigraphy, and facies of Central Iran including the Kashmar (Boghu Mountains), Tabas (Derenjal Mountains, Ozbak-Kuh), Anarak (Pol-e Khavand) and Kerman regions is reviewed and updated. The current state of knowledge of the Silurian in the Zagros Basin, Alborz, Kopet-Dagh and Talysh regions, as well as in a few areas scattered across the Sabzevar Zone, and the Sanandaj-Sirjan terranes is also reviewed. Silurian volcanism in various parts of Iran is briefly discussed. The end of the Ordovician coincided with a widespread regression across Iran synchronous with the Hirnantian glaciation, and only in the Zagros Basin is there a continuous Ordovician-Silurian transition represented by graptolitic black shales of the Sarchahan Formation. In the Central-East Iranian Platform marine sedimentation re-commenced in the early to mid Aeronian. By the Sheinwoodian, carbonate platform depositional environments were established along its north-eastern margin. In other parts of Iran (e.g., Kopet-Dagh and the Sabzevar Zone), siliciclastic sedimentation continued probably into the late Silurian. The Silurian conodont and brachiopod biostratigraphy of Central Iran is significantly updated facilitating a precise correlation with the Standard Global Chronostratigraphic Scale, as well as with key Silurian sections in other parts of Iran. The Silurian lithostratigraphy is considerably revised and two new lithostratigraphical units, namely the Boghu and Dahaneh-Kalut formations, are introduced.
The Numerical and Experimental Analysis of Ballizing Process of Steel Tubes
Authors: Dyl T.
Published: July 2017

This paper presents chosen results of experimental and numerical research of ballizing process of the steel tubes. Ballizing process is a method of burnishing technology of an internal diameter by precisely forcing a ball through a slightly undersized pre-machined tubes. Ballizing process is a fast, low-cost process for sizing and finishing tubes. It consists of pressing a slightly oversized ball through an unfinished tube to quickly bring the hole to desired size. The ball is typically made from a very hard material such as tungsten carbide or bearing steel. Ballizing process is by cold surface plastic forming of the surface structure, thereby leaving a layer of harder material and reducing its roughness. After theoretical and experimental analysis it was determined that the smaller the diameter of the balls, the bigger intensity of stress and strain and strain rate. The paper presents influence of ballizing process on the strain and stress state and on the surface roughness reduction rate of the steel tubes.
An Analysis of the Quality of the Thick-Walled S355J2+N Steel Joint Welded by the Mag Method
Authors: Krawczyk R.
Published: July 2017

An analysis of the quality of the thick-walled S355J2+N steel welded joint used most frequently in the general-building, power and other contemporary steel constructions is presented in the following article. A process of examining welding technologies was made on the tick-walled butt joints of plates by using the MAG – 135 welding method. The aim of the discussed topic was to optimize the process of welding thick-walled welded joints due to their mechanical strength properties and efficiency.
Effect of Laser Preheating AISI 4140 Specimens for Micro-Forging
Authors: Jung C. , Lee M.G. , Jeon Y.
Published: July 2017

Many high performance and permanent service parts require suitable material characteristics-high fatigue strength is one of the most important characteristics. For this reason, surface treatment processes are essential to increase the material performance and avoid the use of costly ineffective material. There exist various surface treatment processes for various applications. Each process has advantages and disadvantages and hybridization can solve various problems. The micro-forging process delivers a controlled and uniform surface hardness, but the depth of the forged surface is limited. On the other hand, laser heat treatment can increase the hardness drastically, but the surface may become brittle, which reduces the fatigue life. Laser-assisted micro-forging is a novel hybrid process of laser heat treatment and micro-forging that has the potential to increase the forging depth and relax the stress caused by the high temperature of the forging process.

This study examines the effect of laser preheating in the micro-forging of AISI 4140. The processes were varied as follows: no treatment, micro-forging only, and laser-assisted micro-forging. The fatigue strength of the specimens was examined by means of an ultrasonic fatigue tester and then compared. The microstructural changes were investigated with respect to the processes by using scanning electron microscopy. In conclusion, it was confirmed that the laser preheating auxiliary forging affects the fatigue life. It was confirmed that the fatigue life was the mostly increased in 550°C temperature laser preheating micro forging process and the temperature was identified as the most important factor.
Mobilität und Leistung
Authors: Nies Sarah , Roller Katrin , Vogl Gerlinde
Published: July 2017

Jenseits genuin mobiler Berufe steht die Verbreitung von Dienstreisen symptomatisch für gewachsene Mobilitätsanforderungen in der Arbeit. Belastungen durch Dienstreisen werden dabei bislang überwiegend als Vereinbarkeitsproblem zwischen Arbeit und Familie und als mentale und körperliche Belastung durch die Reisetätigkeit selbst thematisiert. Auf Basis einer qualitativen Untersuchung diskutiert der Beitrag Mobilitätserleben, Belastungen und Bewältigungsstrategien auf unterschiedlichen raum-zeitlichen Ebenen und setzt diese mit ergebnisorientierten Formen der Leistungssteuerung in den Unternehmen in Bezug. Die empirischen Ergebnisse verdeutlichen, dass Dienstreisende nicht nur vor der Aufgabe stehen, arbeitsbedingte Mobilität mit dem Privatleben zu vereinbaren, sondern dass die mobilitätsbedingten Abwesenheiten auch zu Vereinbarkeitskonflikteninnerhalbder Arbeit - zwischen Mobilitätserfordernissen und den Anforderungen an der regulären Arbeitsstätte führen. Private Zeit wird dabei zur „Verhandlungsmasse“ von Bewältigungsstrategien und Entgrenzung zu einer Ressource, um arbeitsbedingte Konflikte zu bewältigen.
Innerbetriebliche Aushandlungen der Reorganisation sozialer Dienstleistungsarbeit
Authors: Kerber-Clasen Stefan
Published: July 2017

Seit Mitte der 2000er Jahre wird der Kindertagesstätten-bereich in Deutschland reformiert, wodurch ein Reorganisationsdruck auf Kitas ausgeübt wird. Daraus resultierende Reorganisationsprozesse werden am Beispiel einer Betriebsfallstudie einer saarländischen Kita nachgezeichnet und analysiert. Der Schwerpunkt liegt auf folgenden beiden Fragen: Wie wirken sich die Reformen im Kita-Bereich auf den Alltag in der Kita aus? Wie handeln die pädagogischen Fachkräfte im Arbeitsprozess die Reorganisation aus? Auf diese Weise werden Erkenntnisse zu bisher kaum untersuchten Aspekten des Reformprozesses im Kita-Bereich gewonnen, die das wissenschaftlich und öffentlich gezeichnete Bild der Veränderungen im Kita-Bereich arbeitssoziologisch differenzieren. Die Studie plädiert zugleich dafür, gegenwärtige Reorganisationsprozesse in sozialen Dienstleistungen als Aushandlungsprozesse zu analysieren.
Erwerbsarbeitsbezogenes Diversity Management
Authors: Peinl Iris , Janke Daniela
Published: July 2017

Diversity Management wird aufgrund unternehmensbezogener Gewinnfriktionen aus der Perspektive der Betriebswirtschaftslehre wichtiger. Unternehmen sprechen für die Sicherung ihres Fachkräftebedarfs vermehrt differente Menschen an und versuchen, diese in den Arbeitsprozess zu integrieren. Diese Notwendigkeit eines Diversity Managements erhöht den Bedarf an interdisziplinärer Forschung und abgeleiteten Handlungsansätzen. Dieser Beitrag beschreibt Diversity und Diversity Management unter einer betriebswirtschaftlichen und konstruktivistischen Perspektive, um auf dieser Grundlage den eigenen, auf erfolgreiche Arbeitsintegration differenter Menschen zielenden Ansatz des erwerbsbezogenen Diversity Managements zu entfalten.
Digitalisierungsprozesse und das Handeln von Betriebsräten
Authors: Georg Arno , Katenkamp Olaf , Guhlemann Kerstin
Published: July 2017

In der digitalen Transformation sind Fragen nach der Rolle der Beschäftigten und ihrer Interessenvertretungen für die Gestaltung der „Arbeit 4.0“ zentral. Welche Möglichkeiten und Gefahren den vernetzten, digitalen Prozessen innewohnen und wie unter diesen Voraussetzungen vorausschauende, gesundheitsförderliche und mitbestimmte Arbeitsgestaltung gelingen kann, ist auch vom Handeln der Interessenvertretungen abhängig. In vielen Betrieben dominieren auf dem Weg in die smarte Produktion jedoch noch Unsicherheiten über die konkreten Auswirkungen der neuen Technologien auf die Menschen und die Ausgestaltung der Mitbestimmung zwischen Schutz und Gestaltung. In den vorgestellten empirischen Ergebnissen aus zwölf Unternehmen zum Betriebsratshandeln zeigen sich unterschiedliche Herangehensweisen an die digitale Transformation, die in einer Typologie dargestellt werden.
How Increasing Supplier Search Cost Can Increase Welfare
Authors: Li Zhiwen , Arnold Michael , Penard Thierry
Published: July 2017

Reductions in search costs are generally found to increase efficiency and welfare. Using a simple search model we show that when an upstream firm incurs a search cost to identify a potential trading partner and the two parties then negotiate the wholesale price, a reduction in search cost can actually reduce welfare. Furthermore, in a market driven by seller search, a search cost of zero is never socially optimal.
Pre-contest Communication Incentives
Authors: Yildirim Mustafa
Published: July 2017

To demonstrate resolution and psychological strength, players often engage in pre-contest communication by publicly stating their desire to win an upcoming contest. Existing explanations for this phenomenon revolve around incomplete information and signaling. In this paper, I offer a complementary explanation that does not rely on signaling. Within a complete information setup, I show that players may have an incentive for pre-contest communication if, in addition to an audience (reputational) cost when the statement does not materialize, the players also incur an audience reward (credibility gain) when the statement materializes.
Meaningful Work, Worthwhile Life, and Self-Respect: Reexamination of the Rawlsian Perspective on Basic Income in a Property-Owning Democracy
Authors: Fukuma Satoshi
Published: July 2017

As is well known, John Rawls opposes the idea and policy of basic income. However, this paper posits that his view of self-respect and activity could accommodate its implementation. Rawls lists the social basis of self-respect in social primary goods as the most important good, but does not assume that it is derived from wage labor alone. It appears that his theory of justice aims to criticize the work-centered (wage-labor) society and to overcome it. Besides, as Rawls desires, for our work to be meaningful and our life worthwhile, we should institutionalize basic income because it can improve workers’ bargaining power and their attitude toward work, in addition to enhancing their leisure time. In this paper, by considering the normative relationship between meaningful work, worthwhile life, and self-respect from a Rawlsian perspective, I inquire into the potential of basic income in his well-ordered society.
Fused multivariate empirical mode decomposition (MEMD) and inverse solution method for EEG source localization
Authors: Khosropanah Pegah , Ramli Abdul Rahman , Lim Kheng Seang , Marhaban Mohammad Hamiruce , Ahmedov Anvarjon
Published: July 2017

EEG source localization is determining possible cortical sources of brain activities with scalp EEG. Generally, every step of the data processing sequence affects the accuracy of EEG source localization. In this paper, we introduce a fused multivariate empirical mode decomposing (MEMD) and inverse solution algorithm with an embedded unsupervised eye blink remover in order to localize the epileptogenic zone accurately. For this purpose, we constructed realistic forward models using MRI and boundary element method (BEM) for each patient to obtain results that are more realistic. We also developed an unsupervised algorithm utilizing a wavelet method to remove eye blink artifacts. Additionally, we applied MEMD, which is one of the recent and suitable feature extraction methods for non-linear, non-stationary, and multivariate signals such as EEG, to extract the signal of interest. We examined the localization results using the two most reliable linear distributed inverse methods in the literature: weighted minimum norm estimation (wMN) and standardized low resolution tomography (sLORETA). Results affirm the success of the proposed algorithm with the highest agreement compared to MRI reference by a specialist. Fusion of MEMD and sLORETA results in approximately zero localization error in terms of spatial difference with the validated MRI reference. High accuracy results of proposed algorithm using non-invasive and low-resolution EEG provide the potential of using this work for pre-surgical evaluation towards epileptogenic zone localization in clinics.
OpenICE medical device interoperability platform overview and requirement analysis
Authors: Arney David , Plourde Jeffrey , Goldman Julian M.
Published: July 2017

We give an overview of OpenICE, an open source implementation of the ASTM standard F2761 for the Integrated Clinical Environment (ICE) that leverages medical device interoperability, together with an analysis of the clinical and non-functional requirements and community process that inspired its design.
Contributions on the Determination of the Relationship among Globalization, Sustainable Development and Energy Security
Authors: Neag Mihai-Marcel , Halmaghi Elisabeta-Emilia , Cucuiet Mâţu Petruţa
Published: July 2017

The integrated approach to current security issues requires the study of human society by adopting the principle of sustainability for policies to be developed and applied according to economic, social and environmental impacts. The internationalization of economies raises a number of requirements for the application of this principle not only in domestic policies but also in external cooperation relations. Sustainability is thus a catalyst for internal and external political decisions, economic actions and public opinion to promote both new structural, institutional reforms and changes in production and consumption behaviours. The energy resources have permanently and overwhelmingly influenced the evolution of human society and its economic development, representing both a reason for cooperation and confrontation and disputes among the actors of the international system, while also shaping the economy, security, foreign policy and states priorities.
Effect of interfacial film on the corrosion behaviour of X80 pipeline steel in a neutral soil environment containing sulphate-reducing bacteria
Authors: Wang Dan , Xie Fei , Li Xue , Wang Xingfa , Liu Jiaqi , Wu Ming
Published: July 2017

X80 pipeline steel is inevitably corroded by sulphate-reducing bacteria (SRB) in soil. Corrosion-induced damage to the pipeline steel could result in serious consequences. Studies have shown the critical role of interfacial film in SRB-induced corrosion. However, the specific effect of interfacial film was not examined. The effect of film on the corrosion of X80 steel in neutral soil environment was determined using scanning electron microscopy, energy-dispersive spectroscopy, and electrochemical impedance spectroscopy. The structure and electrochemical characteristics of the surface film of X80 steel were examined in the presence of SRB in Shenyang soil. The results showed that, at the beginning of immersion (14 h), the steel surface mainly adsorbed the SRB biofilm, and the biofilm slowed down the corrosion reaction. A small amount of the biofilm and corrosion product film was observed on the electrode surface after immersion for 14–48 h. The corrosion product film destroyed the protection of the biofilm, increasing corrosion. After immersion for 48 h, the corrosion product contents and polarisation resistance increased. After immersion for 240 h, a dense corrosion product film formed on the sample surface, showing the least corrosion. The protective effect of corrosion products on X80 steel was much greater than that of the biofilm.
Modeling galvanic coupling and localized damage initiation in airframe structures
Authors: Nickerson William C. , Iyyer Nagaraja , Legg Keith , Amiri Mehdi
Published: July 2017

Traditionally, airframe structures are designed for immediate mechanical performance and loads-only structural response; the lifetime of aircraft structures is predicted on these analyses and environmental degradation of properties over the life cycle and during operations is often an afterthought. Although the maintenance of aircraft structures is primarily determined by material degradation, galvanic management of airframe designs and corrosion-resistant material selection have never been done systematically. From end-of-life tear-down inspections, we know that, predominantly, structural failures are initiated from corrosion features, especially those accelerated by dissimilar material coupling. In its most simplistic form, this environmental exposure, “loading”, creates corrosion features, such as pitting, that produce crack initiation morphologies; cracks nucleate from these features and then grow under the combined influence of mechanical stress and corrosion, eventually leading to structural failure. There is clearly a strong correlation between corrosion and structural damage, which we think of as corrosion fatigue and stress corrosion cracking. Office of Naval Research’s Sea-Based Aviation program is developing computational approaches to corrosion activity prediction, crack initiation and crack growth, with the ultimate aim of predicting service life in terms of the combination of mechanical and chemical stress. This approach is intended to be the basis for design of durable aircraft structures, using design principles that will take into account both stress and corrosion in the design phase, rather than designing for stress and then maintaining for corrosion.
Links Between Creative Performance and Post-Formal Thought
Authors: Kaya Asli Nazife , Cikis Seniz
Published: July 2017

The aim of this study is to reveal relations between creativity in design and the cognitive developmental stages of designers within a Post-Piagetian approach. In this study design processes were deeply inspected with the aim of obtaining more comprehensive information about the effects of individual’s cognitive status on the design processes, problemsolving and quality of idea generation . In this field, studies done so far have been conducted on test results as indicators of creativity. Withinthe present study, however, protocol analyses were also evaluated, in addition to test results, and thanks to this addition, it was possible to determine the qualitative and quantitative effects of cognitive developmental stages on creativity. A total of twenty-five students voluntarily participated in the research. To collect data, two different methods were employed. The Social Paradigm Belief Inventory (SPBI), was employed to determine students' cognitive stages and scores, and the Think-aloud protocol was used to elicit verbal reports of the thought sequences of the students. In order to analyse the verbal reports reflecting designers' cognitive activities, the method of Linkography was conducted and the general statistics of segments were measured. To assess the relations between creativity in design and the cognitive developmental stages of the designers, SPBI scores and the general statistical values obtained from the design sessions were correlated. Findings showed that there is a strong and significant correlation between the cognitive development levels and creativity, in favour of dialectical thinking.
A new synthetic route to benzophenone derivatives
Authors: Abu-Melha Sraa
Published: July 2017

The rearrangement reaction of 1-alkyl-2-(benzoylmethyl)pyridinium iodides 3a–d, 6 in the presence of various nucleophiles leads to 2-alkylaminobenzophenone derivatives 4a–c. Best results were achieved with alkylammonium sulfites as recyclization reagents.
An efficient approach to the synthesis of coumarin-fused dihydropyridinones
Authors: Firoozpour Loghman , Nikookar Hamideh , Moghimi Setareh , Mahdavi Mohammad , Asadipour Ali , Ranjbar Parviz Rashidi , Foroumadi Alireza
Published: July 2017

3,4-Dihydro-2H-chromeno[4,3-b]pyridine-2,5(1H)-dione derivatives were efficiently prepared by the reaction of 4-hydroxycoumarin, ammonia, aromatic aldehyde and Meldrum’s acid in refluxing 1-propanol.
Chemical and pharmacological research on the plants from genus Ajuga
Authors: Qing Xia , Yan Hui-Min , Ni Zhi-Yu , Vavricka Christopher J. , Zhang Man-Li , Shi Qing-Wen , Gu Yu-Cheng , Kiyota Hiromasa
Published: July 2017

The genus Ajuga, a member of the Lamiaceae family, is comprised of more than 300 species of annual and perennial herbaceous flowering plants mainly distributed throughout the temperate regions of Asia, Europe, Australia, North America and Africa. These plants are used as folk medicines effective for rheumatic fevers, dysentery, malaria, hypertension, diabetes and gastrointestinal disorders, as well as anthelmintic, astringent, febrifuge diuretic, antifungal and anti-inflammatory agents. A variety of constituents has been isolated from these plants. This review summarizes the phytochemical progress of the genus Ajuga and lists the compounds isolated up to 2014.
Effect of Multidirectional Forging and Heat Treatment on Mechanical Properties of In Situ ZrB2p/6061Al Composites
Authors: Zeng Yida , Chao Yuhjin , Luo Zhen , Cai Yangchuan , Song Renfeng
Published: July 2017

Aluminum matrix composites that were reinforced by in situ zirconium diboride nanoparticles were fabricated from an aluminum-potassium tetrafluoroborate-potassium hexafluorozirconate system via a direct-melt reaction. The morphologies of the in situ particles and the mechanical properties of the composite were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry, optical microscopy and tensile tests. X-ray diffractometry and energy-dispersive X-ray spectroscopy showed the existence of zirconium diboride in the composite. Multidirectional forging and heat treatment were used to determine the effect of plastic deformation and heat treatment for the highest tensile strength applied to the composite. Multidirectional forging and heat treatment have a positive influence on the composite microstructure and tensile strength, which increase by 21.81 % and 13.43 %, respectively. The mechanism of multidirectional forging and heat treatment that affects the composite mechanical properties has been discussed. The heat-treatment parameters that affect the tensile strength include the solution-treatment temperature, aging temperature and aging time. The highest tensile strength with moderate extensibility loss was achieved for a specimen that was solution treated for 4 h at 793 K and with aging at 423 K for 4 h.
Influence of Heat Treatment on Fracture Toughness and Wear Resistance of Nicral-Zro2 Multilayered Thermal Barrier Coating
Authors: Ye Zibo , Wang Guanghong
Published: July 2017

The chemical composition and fracture toughness of thermal barrier coatings (TBCs) before and after heat treatment were characterized, and the cracks around the interface between the coating and the substrate could be successfully eliminated and meanwhile the porosity of the coatings tended to reduce. The XRD analysis revealed the coatings were composed of non-transformable tetragonal t’ phase of ZrO2 and $\gamma $-(Ni, Cr) with minor Ni3Al ($\gamma ^' $) precipitates. Additionally, the relationship between the heat treatment and wear resistance was systematically studied. The results indicated that both the hardness and fracture toughness increased after quenching process. The oxidation wear became more prominent after heat treatment, which probably resulted from the better bonding strength of coatings. Dense and homogeneous microstructure introduced by vacuum oil-quenching improved stabilization of the weight gain during thermal cycle test.
Study on the Practical Stability of First-Order Difference Power Market Model with Variable Coefficient
Authors: Lu Zhanhui , Wang Chengyong , Yang Yuhua , Li Gengyin
Published: July 2017

In this paper, the dynamic equilibrium of power market is analyzed by using the economics principle. In the assumption that the market demand is the nonlinear function with variable coefficients of the price forecast, and the market supply is the nonlinear function with variable coefficients of the spot price, first-order difference power market model with variable coefficient is established. The coefficients of power market model are made by the original time series, such as electricity price and demand, and supply elasticity. Besides, the paper also discusses the practical stability and instability of the power market model by means of Lyapunov function and difference inequality, getting a series of criteria for judging the practical stability and instability of the power market and estimation formula of the ultimate convergence boundary. Finally, the validity of these models and Lyapunov stability conditions are simulated by using the data of California.
Microencapsulation of Bioactive Compounds from Blackberry Pomace (Rubus fruticosus) by Spray Drying Technique
Authors: Santos Suelen Siqueira dos , Rodrigues Letícia Misturini , da Costa Silvio Cláudio , Bergamasco Rita de Cassia , Madrona Grasiele Scaramal
Published: July 2017

Blackberry is highly appreciated for the enjoyable color and flavor. About 20 % of the pomace is generated in its processing and often unused, presenting potential use by the food industry. Thus, the present study aimed to microencapsulate extracts of the blackberry pomace applying spray dryer process. Pure extracts (aqueous and hydroalcoholic solution) and the encapsulating agent (maltodextrin DE 10), in a ratio of 1:1 (w/w), were spray dried and analyzed for total anthocyanins, antioxidant activity, phenolics, HPLC-DAD chromatography, instrumental color and scanning electron microscopy. Hydroalcoholic extraction was more efficient (1.5 times) for anthocyanins encapsulation than aqueous extraction. However, for phenolic compounds the highest efficiency (1.2 times) was in the aqueous solution. The majority bioactive compounds were gallic acid and cyanidin. Considering that water is a low cost and ecofriendly solvent, it is indicated this type of extraction to obtain microcapsules of blackberry pomace mainly for future applications by food industry.
Effects of pomegranate peel extract on histopathology, testosterone levels and sperm of testicular torsion–detorsion induced in adult Wistar rats
Authors: Beigi Boroujeni Mandana , Shahrokhi Said Saied , Birjandi Mahdi , Abbaszadeh Abolfazl , Beyranvand Fatemeh , Hamoleh Sakineh , Zandbaf Zohreh , Gholami Mohammadreza
Published: July 2017

Background

In the present study, effects of pomegranate peel extract have been evaluated on decreasing the damage induced by testis torsion.

Methods

In this study, 30 adult Wistar rats were randomly divided into three groups of control, experimental (1) and experimental (2). Control: no ischemia, received vehicle alone, exposed to sham operation. Experimental (1): Received the vehicle alone during ischemia followed by 60 days’ reperfusion. Experimental (2): After performing ischemia reperfusion, 500 mg/kg of pomegranate peel extract has been used for 60 days. Blood samples and sperm samples were collected. Testes were harvested and stained with haematoxylin and eosin to study the structure of seminiferous tubules.

Results

The statistical comparison between sperm count and their viability and testosterone hormone amount showed a significant difference between control and experimental (1) groups and control and experimental (2) groups. The results showed an improvement of morphological condition of seminiferous tubules.

Conclusions

Pomegranate peel extract has revealed desirable changes on the effective parameters in infertility.
A Fast Internal Wave Detection Method Based on PCANet for Ocean Monitoring
Authors: Wang Shengke , Dong Qinghong , Duan Lianghua , Sun Yujuan , Jian Muwei , Li Jianzhong , Dong Junyu
Published: July 2017

Research on internal waves in the coastal ocean is one of the most important tasks both in physical oceanography and ocean monitoring network. Currently, how to quickly and accurately detect the ocean internal waves from the huge ocean surface is still a challenging issue. In this paper, we model the ocean internal wave detection as a task of region classification for texture images and then propose a rapid internal waves detection method based on a deep learning framework (PCANet). In the proposed method, two models have been trained: one is the deep feature representation model, which combines principal component analysis (PCA), binary hashing, and block-wise histograms and can extract more distinguishing features than handcraft feature. Moreover, because the filter learning in PCANet does not require regularized parameters and numerical optimization solver, the training process of the representation model is very fast. The other one is a classification model based on a linear support vector machine. The object proposal method has been applied to get the possible candidates when analyzing a captured image, which dramatically decreases the searching time. Experiment results on the data set captured by unmanned aerial vehicles verify the speed ability and effectiveness of the proposed method.
Optical Buffer Design based on SOA and DCFBG
Authors: Kifayat Numan , Kaleem Mohammad , Aziz Khurram , Ishaq Muhammad
Published: July 2017

Presently, research activities are geared towards optical switching technologies that involve all-optical switching, without transformation from optical domain to electronic domain. However, blocking in these systems is a huge problem due to the absence of appropriate optical buffers. In this paper, we propose an optical buffer design based on SOA and DCFBG (dispersion compensation fiber Bragg grating) for contention resolution in all-optically switched networks, and hence improved the power performance of the existing design.
10 Gbps-60 GHz RoF Transmission System for 5 G Applications
Authors: Chaudhary Sushank , Thakur Deepika , Sharma Abhishek
Published: July 2017

This work is focused on transmission of 10 Gbps data and 60 GHz millimeter signal over 60 km optical fiber for 5 G applications. 5 G networks generally use millimeter range of frequencies. Radio over fiber is revolutionary technology to transmit radio signals over optical fiber. Furthermore, the comparative analysis of non-return to zero (NRZ) and return to zero (RZ) encoding schemes is also done. The results are reported in terms of Q-factor, bit error rate and eye diagrams. The reported results show the successful transmission of high speed 10 Gbps data and 60 GHz millimeter signal over 60 km optical fiber.
Effect of Crosstalk in Super Dense Wavelength Division Multiplexing System using Hybrid Optical Amplifier
Authors: Kumar Chakresh , Goyal Rakesh
Published: July 2017

Analysis of proposed 400×10 Gbps super dense wavelength division multiplexing (SD-WDM) system has been evaluated in term of crosstalk and optical signal to crosstalk ratio (OSCR). Amplification is carried out using RAMAN-EDFA hybrid optical amplifier (HOA) for the transmission of 300 km. The pump power of 550 mW at 1520 nm and 580 mW at 1530 nm are set to RAMAN and EDFA optical amplifier respectively. Further, the power level of 0 dBm with channel spacing of 100 GHz has shown the remarkable outcome of controlling the fiber nonlinearity to maintain the best rating optical communication for long haul distance.
Kinematic diffusion approach to describe recharge phenomena in unsaturated fractured chalk
Authors: Pastore Nicola , Cherubini Claudia , Giasi Concetta I.
Published: July 2017

When dealing with groundwater resources, a better knowledge of the hydrological processes governing flow in the unsaturated zone would improve the assessment of the natural aquifer recharge and its vulnerability to contamination. In North West Europe groundwater from unconfined chalk aquifers constitutes a major water resource, therefore the need for a good hydrological understanding of the chalk unsaturated zone is essential, as it is the main control for aquifer recharge. In the North Paris Basin, much of the recharge must pass through a regional chalk bed that is composed of a porous matrix with embedded fractures. The case study regards the role of the thick unsaturated zone of the Cretaceous chalk aquifer in Picardy (North of France) that controls the hydraulic response to rainfall. In order to describe the flow rate that reaches the water table, the kinematic diffusion theory has been applied that treats the unsaturated water flow equation as a wave equation composed of diffusive and gravitational components. The kinematic diffusion model has proved to be a convenient method to study groundwater recharge processes in that it was able to provide a satisfactory fitting both for rising and falling periods of water table fluctuation. It has also proved to give an answer to the question whether unsaturated flow can be described using the theory of kinematic waves. The answer to the question depends principally on the status of soil moisture. For higher values of hydraulic Peclet number (increasing saturation), the pressure wave velocities dominate and the preferential flow paths is provided by the shallow fractures in the vadose zone. With decreasing values of hydraulic Peclet number (increasing water tension), rapid wave velocities are mostly due to the diffusion of the flow wave. Diffusive phenomena are provided by matrix and fracture-matrix interaction.

The use of a kinematic wave in this context constitutes a good simplified approach especially in cases when there is a lack of information concerning the hydraulic properties of the fractures/macropores close to saturation.
Possible numbers of x’s in an {x, y}-matrix with a given rank
Authors: Ma Chao
Published: July 2017

Let x, y be two distinct real numbers. An {x, y}-matrix is a matrix whose entries are either x or y. We determine the possible numbers of x’s in an {x, y}-matrix with a given rank. Our proof is constructive.
New error bounds for linear complementarity problems of weakly chained diagonally dominant B-matrices
Authors: Sun Deshu , Wang Feng
Published: July 2017

Some new error bounds for the linear complementarity problems are obtained when the involved matrices are weakly chained diagonally dominant B-matrices. Numerical examples are given to show the effectiveness of the proposed bounds.
Boundedness of vector-valued B-singular integral operators in Lebesgue spaces
Authors: Keles Seyda , Omarova Mehriban N.
Published: July 2017

We study the vector-valued B-singular integral operators associated with the Laplace-Bessel differential operator
$$\triangle_{B}=\sum\limits_{k=1}^{n-1}\frac{\partial^{2}}{\partial x_{k}^{2}}+(\frac{\partial^{2}}{\partial x_{n}^{2}}+\frac{2v}{x_{n}}\frac{\partial}{\partial x_{n}}) , v>0.$$
We prove the boundedness of vector-valued B-singular integral operators A from $L_{p,v}(\mathbb{R}_{+}^{n}, H_{1}) \,{\rm to}\, L_{p,v}(\mathbb{R}_{+}^{n}, H_{2}),$ 1 < p < ∞, where H1 and H2 are separable Hilbert spaces.
On the Golomb’s conjecture and Lehmer’s numbers
Authors: Tingting Wang , Xiaonan Wang
Published: July 2017

Let p be an odd prime. For each integer a with 1 ≤ a ≤ p − 1, it is clear that there exists one and only one ā with 1 ≤ ā ≤ p − 1 such that a · ā ≡ 1 mod p. Let N(p) denote the set of all primitive roots a mod p with 1 ≤ a ≤ p − 1 in which a and ā are of opposite parity. The main purpose of this paper is using the analytic method and the estimate for the hybrid exponential sums to study the solvability of the congruence a + b ≡ 1 mod p with a, b ∈ N(p), and give a sharper asymptotic formula for the number of the solutions of the congruence equation.
Saturated evanescent-wave absorption of few-layer graphene-covered side-polished single-mode fiber for all-optical switching
Authors: Peng Kaung-Jay , Wu Chun-Lung , Lin Yung-Hsiang , Wang Hwai-Yung , Cheng Chih-Hsien , Chi Yu-Chieh , Lin Gong-Ru
Published: July 2017

Using the evanescent-wave saturation effect of hydrogen-free low-temperature synthesized few-layer graphene covered on the cladding region of a side-polished single-mode fiber, a blue pump/infrared probe-based all-optical switch is demonstrated with specific wavelength-dependent probe modulation efficiency. Under the illumination of a blue laser diode at 405 nm, the few-layer graphene exhibits cross-gain modulation at different wavelengths covering the C- and L-bands. At a probe power of 0.5 mW, the L-band switching throughput power variant of 16 μW results in a probe modulation depth of 3.2%. Blue shifting the probe wavelength from 1580 to 1520 nm further enlarges the switching throughput power variant to 24 mW and enhances the probe modulation depth to 5%. Enlarging the probe power from 0.5 to 1 mW further enlarges the switching throughput power variant from 25 to 58 μW to promote its probe modulation depth of up to 5.8% at 1520 nm. In contrast, the probe modulation depth degrades from 5.1% to 1.2% as the pumping power reduces from 85 to 24 mW, which is attributed to the saturable absorption of the few-layer graphene-based evanescent-wave absorber. The modulation depth at wavelength of 1550 nm under a probe power of 1 mW increases from 1.2% to 5.1%, as more carriers can be excited when increasing the blue laser power from 24 to 85 mW, whereas it decreases from 5.1% to 3.3% by increasing the input probe power from 1 to 2 mW to show an easier saturated condition at longer wavelength.
From isolated light-harvesting complexes to the thylakoid membrane: a single-molecule perspective
Authors: Gruber J. Michael , Malý Pavel , Krüger Tjaart P.J. , Grondelle Rienk van
Published: July 2017

The conversion of solar radiation to chemical energy in plants and green algae takes place in the thylakoid membrane. This amphiphilic environment hosts a complex arrangement of light-harvesting pigment-protein complexes that absorb light and transfer the excitation energy to photochemically active reaction centers. This efficient light-harvesting capacity is moreover tightly regulated by a photoprotective mechanism called non-photochemical quenching to avoid the stress-induced destruction of the catalytic reaction center. In this review we provide an overview of single-molecule fluorescence measurements on plant light-harvesting complexes (LHCs) of varying sizes with the aim of bridging the gap between the smallest isolated complexes, which have been well-characterized, and the native photosystem. The smallest complexes contain only a small number (10–20) of interacting chlorophylls, while the native photosystem contains dozens of protein subunits and many hundreds of connected pigments. We discuss the functional significance of conformational dynamics, the lipid environment, and the structural arrangement of this fascinating nano-machinery. The described experimental results can be utilized to build mathematical-physical models in a bottom-up approach, which can then be tested on larger in vivo systems. The results also clearly showcase the general property of biological systems to utilize the same system properties for different purposes. In this case it is the regulated conformational flexibility that allows LHCs to switch between efficient light-harvesting and a photoprotective function.
High-efficiency/CRI/color stability warm white organic light-emitting diodes by incorporating ultrathin phosphorescence layers in a blue fluorescence layer
Authors: Miao Yanqin , Wang Kexiang , Zhao Bo , Gao Long , Tao Peng , Liu Xuguang , Hao Yuying , Wang Hua , Xu Bingshe , Zhu Furong
Published: July 2017

By incorporating ultrathin (<0.1 nm) green, yellow, and red phosphorescence layers with different sequence arrangements in a blue fluorescence layer, four unique and simplified fluorescence/phosphorescence (F/P) hybrid, white organic light-emitting diodes (WOLEDs) were obtained. All four devices realize good warm white light emission, with high color rending index (CRI) of >80, low correlated color temperature of <3600 K, and high color stability at a wide voltage range of 5 V–9 V. These hybrid WOLEDs also reveal high forward-viewing external quantum efficiencies (EQE) of 17.82%–19.34%, which are close to the theoretical value of 20%, indicating an almost complete exciton harvesting. In addition, the electroluminescence spectra of the hybrid WOLEDs can be easily improved by only changing the incorporating sequence of the ultrathin phosphorescence layers without device efficiency loss. For example, the hybrid WOLED with an incorporation sequence of ultrathin red/yellow/green phosphorescence layers exhibits an ultra-high CRI of 96 and a high EQE of 19.34%. To the best of our knowledge, this is the first WOLED with good tradeoff among device efficiency, CRI, and color stability. The introduction of ultrathin (<0.1 nm) phosphorescence layers can also greatly reduce the consumption of phosphorescent emitters as well as simplify device structures and fabrication process, thus leading to low cost. Such a finding is very meaningful for the potential commercialization of hybrid WOLEDs.
Effect of temperature on the structural, linear, and nonlinear optical properties of MgO-doped graphene oxide nanocomposites
Authors: Kimiagar Salimeh , Abrinaei Fahimeh
Published: July 2017

Magnesium oxide (MgO)-graphene oxide (GO) nanocomposites were prepared by the hydrothermal method at different temperatures. The effect of growth temperature on the structural, linear, and nonlinear optical (NLO) parameters was investigated. The decoration of MgO on GO sheets was confirmed by X-ray diffraction, scanning electron microscopy, Fourier transform infrared, and UV-visible (UV-vis) spectroscopy analyses. The energy band-gaps of MgO-GO nanocomposites were calculated from UV-vis spectrum using Tauc plot. The NLO parameters of MgO-GO nanocomposites were calculated for the first time by the simple Z-scan technique with nanosecond Nd:YAG laser at 532 nm. The nonlinear absorption coefficient β and nonlinear refractive index n
2 for MgO-GO nanocomposites at the laser intensity of 1.1×108 W/cm2 were measured to be in the order of 10−7 cm/W and 10−12 cm2/W, respectively. The third-order NLO susceptibility of MgO-GO nanocomposites was measured in the order of 10−9 esu. The results showed that MgO-GO structures have negative nonlinearity as well as good nonlinear two-photon absorption at 532 nm. Furthermore, the NLO parameters increased by the enhancement of the growth temperature. As the investigation of new materials plays an important role in the advancement of optoelectronics, MgO-GO nanocomposites possess potential applications in NLO devices.
Engineering light emission of two-dimensional materials in both the weak and strong coupling regimes
Authors: Brotons-Gisbert Mauro , Martínez-Pastor Juan P. , Ballesteros Guillem C. , Gerardot Brian D. , Sánchez-Royo Juan F.
Published: July 2017

Two-dimensional (2D) materials have promising applications in optoelectronics, photonics, and quantum technologies. However, their intrinsically low light absorption limits their performance, and potential devices must be accurately engineered for optimal operation. Here, we apply a transfer matrix-based source-term method to optimize light absorption and emission in 2D materials and related devices in weak and strong coupling regimes. The implemented analytical model accurately accounts for experimental results reported for representative 2D materials such as graphene and MoS2. The model has been extended to propose structures to optimize light emission by exciton recombination in MoS2 single layers, light extraction from arbitrarily oriented dipole monolayers, and single-photon emission in 2D materials. Also, it has been successfully applied to retrieve exciton-cavity interaction parameters from MoS2 microcavity experiments. The present model appears as a powerful and versatile tool for the design of new optoelectronic devices based on 2D semiconductors such as quantum light sources and polariton lasers.
Controllable all-fiber generation/conversion of circularly polarized orbital angular momentum beams using long period fiber gratings
Authors: Han Ya , Liu Yan-Ge , Wang Zhi , Huang Wei , Chen Lei , Zhang Hong-Wei , Yang Kang
Published: July 2017

Mode-division multiplexing (MDM) is a promising technology for increasing the data-carrying capacity of a single few-mode optical fiber. The flexible mode manipulation would be highly desired in a robust MDM network. Recently, orbital angular momentum (OAM) modes have received wide attention as a new spatial mode basis. In this paper, we firstly proposed a long period fiber grating (LPFG) system to realize mode conversions between the higher order LP core modes in four-mode fiber. Based on the proposed system, we, for the first time, demonstrate the controllable all-fiber generation and conversion of the higher order LP core modes to the first and second order circularly polarized OAM beams with all the combinations of spin and OAM. Therefore, the proposed LPFG system can be potentially used as a controllable higher order OAM beam switch and a physical layer of the translating protocol from the conventional LP modes communication to the OAM modes communication in the future mode carrier telecommunication system and light calculation protocols.