bluuebunny/crossref_metadata_2025 huggingface dataset:
Persistent loss of biologically-rich tropical forests in the Indian Eastern Himalaya
Authors: Sheth Chintan , Datta Aparajita , Parashuram Devathi
Published: June 2020

Using fine-resolution satellite imagery from multiple satellite data products, we assessed the change in forest cover of a state-managed Reserve Forest (RF) located in Indiaâs Eastern Himalaya biodiversity hot-spot. 4.6% of forest cover was lost from Papum RF between 2013 and 2017 at the rate of 8.2 km2 yearâ1. Three species of hornbills: Great Hornbill Linnaeus, 1758, Wreathed Hornbill (Shaw, 1811) and Oriental Pied Hornbill (Shaw, 1808), that are functionally important are found here with nesting habitat in the areas affected by illegal logging. Therefore, we assessed the habitat loss within a 1 km radius around 29 nest trees. From 2011 to 2019, forest cover declined from 38.55 km to 21.94 km around these hornbill nest trees. Illegal logging is the main driver that is depleting forest cover within this important bird area. Our results highlight the ongoing threats to biologically-rich forests and the need for urgent measures to halt this loss. We suggest that this study has practical implications for the monitoring and governance of state-managed forests in Arunachal Pradesh.Buceros bicornisRhyticeros undulatusAnthracoceros albirostris22
Improved Depth Estimation for Occlusion Scenes Using a Light-Field Camera
Authors: Yang Changkun , Liu Zhaoqin , Di Kaichang , Hu Changqing , Wang Yexin , Liang Wuyang
Published: June 2020

With the development of light-field imaging technology, depth estimation using light-field cameras has become a hot topic in recent years. Even through many algorithms have achieved good performance for depth estimation using light-field cameras, removing the influence of occlusion,
especially multi-occlusion, is still a challenging task. The photo-consistency assumption does not hold in the presence of occlusions, which makes most depth estimation of light-field imaging unreliable. In this article, a novel method to handle complex occlusion in depth estimation of light-field
imaging is proposed. The method can effectively identify occluded pixels using a refocusing algorithm, accurately select unoccluded views using the adaptive unoccluded-view identification algorithm, and then improve the depth estimation by computing the cost volumes in the unoccluded views.
Experimental results demonstrate the advantages of our proposed algorithm compared with conventional state-of-the art algorithms on both synthetic and real light-field data sets.
Burned Area Detection in the Brazilian Amazon using Spectral Indices and GEOBIA
Authors: Penha Thales Vaz , Körting Thales Sehn , Fonseca Leila Maria Garcia , Silva Júnior Celso Henrique Leite , Pletsch Mikhaela Aloísia Jessie Santos , Anderson Liana Oighenstein , Morelli Fabiano
Published: June 2020

Mapping refined burned areas (BA) in the Brazilian Amazon is still a challenge. The main difficulty of BA detection in large areas is the presence of cloud cover and water bodies. The use of different data sources of medium spatial resolution satellite images can provide a higher availability of cloud-free images. Besides that, it may decrease the uncertainties associated with coarse spatial resolution data (>250m), which can under or overestimate BA and hinder the detection of small BA patches (<0.1km²). In this study, we propose an innovative methodology based on spectral indices and geographic object-based image analysis (GEOBIA), using medium spatial resolution images to improve BA detection in the Brazilian Amazon region. Firstly, we assessed the performance of nine spectral indices in two study areas, derived from Landsat-8 OLI and Sentinel-2A MSI data to identify the most suitable index for BA detection in this region. Then, we refined this data through the GEOBIA-based model. The results showed that the Burned Area Index (BAI) was the most suitable index for BA mapping (M index >1.5) for both sensors. Our model allowed detecting more than 80% of small BA and also presented high Dice coefficient values (~0.70) with low omission and commission errors (0.22 and 0.32, respectively). Such combined approach corresponds to a novel contribution to the BA detection in the Brazilian Amazon region and for enhancing the operational product generation.
Calibração da Plataforma de um Sistema de Visão Omnidirecional composto por uma Câmara e um Espelho Cônico
Authors: Marcato Junior José , Akiyama Thales Shoiti , Tommaselli Antonio Maria Garcia , Moraes Marcus Vinícius Antunes de , Fernandes Vanessa Jordão Marcato
Published: June 2020

Os sistemas de visão omnidirecional permitem um campo de imageamento de 360° e são aplicados em diversas áreas do conhecimento, incluindo a Fotogrametria à curta distância. Para obter medidas confiáveis, objetivo da Fotogrametria, exige-se a calibração do sistema, em que os parâmetros dos modelos matemáticos são estimados. A calibração do sistema é dividida em calibração interna e da plataforma. O objetivo principal desse trabalho consiste em realizar a calibração da plataforma de um sistema de visão omnidirecional composto por uma câmara e um espelho cônico. Na calibração da plataforma foram estimados os parâmetros que relacionam o sistema de imageamento com o sistema de georreferenciamento direto, composto por receptor GNSS (Global Navigation Satellite System – Sistema global de navegação por satélite) e IMU (Inertial Measurement Unity – Unidade de Medida Inercial). Estimaram-se os ângulos de desalinhamento (boresight) da IMU com relação ao referencial do cone e os deslocamentos (lever arm) do vértice do cone ao centro da antena GNSS. A incerteza na estimativa do lever arm é, no mínimo, 10 vezes menor que a precisão obtida com o receptor GNSS no modo cinemático, o que indica uma qualidade adequada para o valor estimado. Com relação aos ângulos de desalinhamento, a REQM (Raiz do Erro Quadrático Médio) foi maior para o ângulo de rotação
Otimização de Rotas de Ônibus baseada em Demanda obtida por Dados de Posicionamento GNSS
Authors: Oliveira Henrique Candido de , Santos Rafael Lino dos , Barbosa Luciano Aparecido , Costa Diogenes Cortijo , Barbosa Ricardo Antunes , Sousa Rafael Pereira de
Published: June 2020

O crescimento urbano na perspectiva de território e população se tornou uma das maiores preocupações deste século. Em função deste fenômeno, órgãos de planejamento e gestão de transporte público do país buscam ofertar um serviço de qualidade baseado em um sistema otimizado da rede de transporte. Entender a demanda de passageiros constitui-se como uma tarefa fundamental deste processo. Assim, o método proposto neste trabalho prevê a determinação da demanda de volume de passageiros de forma automatizada a partir de dados de posicionamento GNSS (Global Navigation Satellite System) fornecidos por uma plataforma IoT (Internet of Things). O trabalho tem por objetivo identificar variações de demanda de passageiros, a partir do uso de mapas de densidade, e otimizar rotas do serviço de transporte público, tendo a Universidade Estadual de Campinas como área de estudo. Experimentos foram realizados a partir de uma das rotas que compreendem o sistema de transporte da Universidade. Os resultados foram satisfatórios, pois apresentaram uma redução de 1,43 km em relação ao percurso realizado pela rota original, representando um impacto financeiro inicial de aproximadamente 18% de redução do custo total anual com a contratação de serviço de transporte. Portanto, o método apresenta-se como uma alternativa viável para obtenção de dados fundamentais para tarefa de roteirização para as linhas de ônibus do campus, podendo ser replicado para os demais trajetos que compõem o sistema de transporte público da Universidade.
Análise do Desempenho de ETR no Monitoramento Dinâmico de Estrutura Metálica por Leitura Contínua de Direções
Authors: Medeiros Leandro Ítalo Barbosa de , Faggion Pedro Luís , Alves Samir de Souza Oliveira
Published: June 2020

As obras de infraestrutura estão sujeitas às ações de forças estáticas, geralmente relacionadas ao peso do próprio corpo estrutural, e a forças dinâmicas, oriundas da ação de agentes externos à estrutura, como o vento e outras cargas móveis. O monitoramento dinâmico de estruturas é realizado, comumente, com utilização de instrumentais não geodésicos, como acelerômetros e extensômetros. Contudo, este artigo apresenta uma alternativa de técnica geodésica para o monitoramento dinâmico de estruturas por meio da análise do desempenho de uma estação total robotizada (ETR) utilizando Leitura Contínua de Direções (LCD), uma metodologia capaz de aumentar a taxa amostral do equipamento para cerca de 20 Hz, além de eliminar a latência entre as medições lineares e angulares. Os experimentos foram realizados em um ponto materializado sobre a passarela que liga os campi Centro Politécnico e Botânico da Universidade Federal do Paraná. Os dados oriundos da ETR foram comparados aos obtidos com levantamento Global Navigation Satellite System (GNSS) no modo relativo cinemático contínuo com frequência de 20 Hz.
Deforestación, violencia y reterritorialización en el Noroeste de la Amazonia colombiana
Authors: Otálvaro-Sierra César Augusto
Published: June 2020

Desde el año 2016, y especialmente después de las negociaciones de paz entre el Estado colombiano y las Fuerzas Armadas Revolucionarias de Colombia-FARC, en este país se viene presentando un aumento dramático de la deforestación, concentrado en el noroeste de su región Amazónica, en donde las dinámicas territoriales han tenido una fuerte influencia y control por parte de las FARC, y que se ha configurado como una frontera de colonización de la amazonia colombiana. Dicho fenómeno ha producido gran atención y preocupación pública, dadas sus implicaciones ambientales, sin embargo, no se ha analizado suficientemente sus causas y consecuencias sociales, las cuales permiten comprender un conflicto que más que ambiental, es socio-ambiental, con profundas raíces en la historia reciente del conflicto armado de esta nación, con diversos intereses sobre el control territorial, y con evidentes conexiones con poderes políticos y económicos, que intentan imponer una proyección y un manejo particular del espacio y la sociedad, haciendo que todo este fenómeno alcance una dimensión territorial más compleja. Teniendo en cuenta dicha motivación analítica, este artículo tiene por objetivo argumentar cómo ese proceso de transformación responde a una lógica de reterritorialización del espacio, que procura establecer una hegemonía para articularlo a las dinámicas económicas de la nación y, por esta vía, alcanzar su control político. Se propone, para esto, un abordaje territorial al análisis de los conflictos, vislumbrándolos como procesos socio-espaciales de naturaleza política, identificando para ello los principales actores e intereses, así como las relaciones del territorio con otros ámbitos nacionales e internacionales.
APPLICATION OF FUZZY TOPSIS FOR SELECTING MOST SUSTAINABLE BUILDING WALL MATERIAL
Authors: Nofal Ahmad , Hammad Ahmed
Published: June 2020

Appropriate selection of construction materials is crucial for the success of any project. Poor choice of materials can lead to higher costs during construction, higher long-term operation and maintenance expenses, and endanger humans and their surrounding environment. Since the three pillars of sustainability cover the economic, social, and environmental aspects, adoption of sustainability principles in decision making will ensure selecting the optimum construction materials. This paper presents a generic model to utilize Fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) principles to compare the sustainability criteria of four wall material alternatives using normalized fuzzy matrices. A case study took place in United Arab Emirates (UAE) to validate the model. Several semi-structured interviews and meetings with industry experts representing material suppliers, engineering consultants, and construction contractors took place during this research. These meetings provided six selection criteria under the three main sustainability categories, agreed-upon weight for each criteria, and evaluation of the four wall material alternatives. Results obtained from consulted experts presented Sandwich Panels as the most sustainable alternative for the case study. The developed model is generic and can be implemented on any construction project, and the alternative selection can change according to the decision-makers’ opinions and preferences.
THE KA LOKO TRAGEDY
Authors: Singh Amarjit
Published: June 2020

The North Shore of Kauai is known for its beautiful beaches, scenery, and tropical paradise. However, the community has faced adversity and tragedy due to the lack of necessary engineering inspections, failure to apply for building permits, negligence, and complacency on behalf of property owner James H. Pflueger, the State of Hawaii, and County of Kauai. The Ka Loko dam broke on March 14, 2006 and the rushing waters wreaked havoc on the community causing mass destruction and ultimately claimed the lives of seven individuals. Multiple civil lawsuits and a criminal case followed where the owner pled no contest to seven counts of manslaughter and one count of reckless endangerment. The purpose of this paper is to conduct a brief analysis of the events surrounding the tragedy and extract the lessons learned and impacts it may have to prevent future disasters from occurring. Among the issues, it was discovered that the emergency spillway had been filled with earth, and that dam inspections were irregularly conducted.
PERFORMANCE OF CONCRETE MODIFIED WITH DISCARDED GLASS AT ELEVATED TEMPERATURES FOR SUSTAINABLE CONSTRUCTION
Authors: Olofinnade Oluwarotimi , Ede Anthony , Ngene Ben , Akpabot Akpabot
Published: June 2020

This study examines the residual strength of concrete produced with crushed discarded soda-lime glass as aggregates after exposure to elevated heating. The natural aggregates, which comprise both the coarse and fine aggregates were partially and completely replaced by 0, 25, 50, 75 and 100% of the discarded glass. The control and samples containing crushed discarded glass aggregates were prepared at constant water-cement ratio (w/c) of 0.50 and the cube samples were exposed to temperatures of 60, 150, 300 and 500°C after curing in water for 90 days. The heating was increased at a constant heating rate of 10°C/min. The strength of the concrete samples was measured before and after exposure to heating after air-cooling of the heated samples. Moreover, scanning electron microscope (SEM) examination was carried out on selected samples to investigate the extent of change in the concrete bonding, especially at higher heating. Test results depict reduction trend in the characteristic strength of the tested samples as the level of heating increases, while the SEM micrographs reveal clear decomposition in the concrete interfaces. However, it was noticed from the results that concrete containing crushed discarded glass show better performance in terms of strength compared to the reference concrete at certain temperature exposure indicating a modified concrete with improved post-fire resistance.
A STAKEHOLDER PERSPECTIVE ON THE IMPLEMENTATION OF SUSTAINABLE CONSTRUCTION PRACTICES
Authors: Mashwama Nokulunga Xolile , Thwala Didibhuku , Aigbavboa Clinton , Hamma-Adama Mansur
Published: June 2020

The South African construction industry accounts for 23% of the greenhouse emissions, while manufactured materials amount to 4% of carbon dioxide emission. The human emission of greenhouse gases is the reason why the earth is warming up and making climate change a serious problem. The study adopted a quantitative approach in order to investigate on a stakeholder’s perspective on level of implementation and awareness of Sustainable Construction Practices (SCPS). A structured survey questionnaire was used as a tool for data collection where the questionnaires were distributed to construction industry stakeholders. Out of the 75 distributed questionnaires, 60 were retrieved and all were valid and usable. The study revealed that sustainable construction practices is partially implemented and the responded are aware of Industrialization building system; construction ecology; life cycle costing; design for the environment; lean construction as the best construction practices that when fully adopted they would contribute greatly to the ecosystem we live in. This study contributes to a wider awareness of SCPs to the professional in the industry.
Speckle-Tracking Echocardiography in Cardio-Oncology and Beyond
Authors: Quintana Raymundo A. , Bui Linh P. , Moudgil Rohit , Palaskas Nicolas , Hassan Saamir , Abe Jun-ichi , Mouhayar Elie , Yusuf Syed Wamique , Hernandez Antonieta , Banchs Jose
Published: June 2020

Speckle-tracking echocardiography has enabled clinicians to detect changes in myocardial function with more sensitivity than that afforded by traditional diastolic and systolic functional measurements, including left ventricular ejection fraction. Speckle-tracking echocardiography enables evaluation of myocardial strain in terms of strain (percent change in length of a myocardial segment relative to its length at baseline) and strain rate (strain per unit of time). Both measurements have potential for use in diagnosing and monitoring the cardiovascular side effects of cancer therapy. Regional and global strain measurements can independently predict outcomes not only in patients who experience cardiovascular complications of cancer and cancer therapy, but also in patients with a variety of other clinical conditions. This review and case series examine the clinical applications and overall usefulness of speckle-tracking echocardiography in cardio-oncology and, more broadly, in clinical cardiology.
Learnings, however wise
Authors: Corno Lyn
Published: June 2020

I wrote this chapter during the COVID-19 pandemic of 2020. How coincidental it is to be writing a reflective memoir at a time when it is hard to avoid reflecting. I had not thought I could tackle this project until well into the year, but sequestration at a rented house in South Carolina gave me time and so the pages multiplied in a different way. With this said, what is omitted is often the most important material for reflection - the emotional moments of childhood and the feelings that come with each turn of event. This is to be an account of things I may have learned, however “wise,” for graduate students or others who would have careers in education and psychology, so it lacks a colorful narrative. The chapter is organized as much by experience as chronology, with six key sections. Readers can find one-sentence lessons signaled by underlined material located at the start of some paragraphs within each key section.
APLIKASI ERROR CORRECTION MECHANISM DALAM ANALISIS DAMPAK PERTUMBUHAN EKONOMI, KONSUMSI ENERGI DAN PERDAGANGAN INTERNASIONAL TERHADAP EMISI CO2 DI INDONESIA
Authors: Kartiasih Fitri , Setiawan Adi
Published: June 2020

Economic development is an effort to improve people's lives. However, economic development has negative externalities. Emissions generated from economic activities can pollute the environment. This study purpose to determine the relationship between economic growth and CO2 emissions based on the Environment Kuznets Curve (EKC) hypothesis and analyze the influence of energy use, economic growth and international trade on CO2 emissions in Indonesia in the period 1977-2014 using Error Correction Mechanism (ECM) analysis. The results showed that the EKC hypothesis does not apply in Indonesia, meaning that economic development carried out during the research period still pursues increased income without regard to environmental quality so that increased per capita income is accompanied by increase in CO2 emissions. Based on econometric analysis of ECM, it shows that the variables of energy use, economic growth and international trade have a statistically significant effect on CO2 emissions in Indonesia in the long run. In the short term, economic growth, and error correction terms have a statistically significant effect while the variables of energy consumption and international trade do not have a statistical effect on CO2 emissions in Indonesia.
COMBINATION OF SYNTHETIC MINORITY OVERSAMPLING TECHNIQUE (SMOTE) AND BACKPROPAGATION NEURAL NETWORK TO CONTRACEPTIVE IUD PREDICTION
Authors: Mustaqim Mustaqim , Warsito Budi , Surarso Bayu
Published: June 2020

Data imbalance occurs when the amount of data in a class is more than other data. The majority class is more data, while the minority class is fewer. Imbalance class will decrease the performance of the classification algorithm. Data on IUD contraceptive use is imbalanced data. National IUD failure in 2018 was 959 or 3.5% from 27.400 users. Synthetic minority oversampling technique (SMOTE) is used to balance data on IUD failure. Balanced data is then predicted with neural networks. The system is for predicting someone when using IUD whether they have a pregnancy or not. This study uses 250 data with 235 major data (not pregnant) and 15 minor data (pregnant). From 250 data divided into two parts, 225 training and 25 testing data. Minority class on training data will be duplicated to 1524%, so that the amount of minority data become balanced with  the majority data. The results of predictive with an accuracy rate of  99.9% at 1000 epoch.
Islamic Values of the Northern Town Square of the Yogyakarta Sultanate
Authors: Suparwoko Woko , Raharjo Wiryono , Saifudin Ahmad
Published: June 2020

Since the end of the 13th century during the era of the Majapahit Kingdom, the Public Square or town square has always become part of the kingdom. The square is a manifestation of public space, an integral part of the spatial layout of the royal capital. This concept was later adopted by cities in Indonesia, which provides an open space right in front of the palace or government office. Public squares as public spaces can play various roles in enhancing the quality of urban life, especially to express the social economic and environmental values. This paper aims to solely focus on the northern town square located inside the palace complex, especially by addressing the Islamic values of the northern town square of the Yogyakarta Sultanate using qualitative approaches in terms of its social economic and environmental aspects. Primary data were directly obtained from the research location by taking some photographs, field observation, and notes, while secondary data were derived from the literature and the Internet. The research suggests that the northern town square serves as the symbol and manifestation of not only the media to relate mankind to God but also the media to relate mankind to nature. In terms of mankind-to-God relation, the northern town square serves as a place for Eid prayers every year, including the Eid Fitr and the Eid Adha. Also, some annual events like the Sekaten are held every year to commemorate the birth of the Prophet Muhammad. The Sekaten Fun Fair to celebrate the birth of the Prophet highlights the Islamic values related to social economic and tourism activities. In the context of northern town square landscape, the element of 64-banyan trees around the northern town square symbolizes the age of the Prophet Muhammad. This tree concept has been successfully protected the environment around the northern town square and serves as a public open space in the city of Yogyakarta.
Ochrona własności rolniczej w świetle ustawy o kształtowaniu ustroju rolnego
Authors: Litwiniuk Przemysław
Published: June 2020

The purpose of the deliberations presented in this article is to assess the protection of agricultural property in the light of the Act of 11 April 2003 on shaping the agricultural system, taking into account its amendments of 2016 and 2019. In the author’s opinion, the provisions of this Act that serve the purpose of the protection of agricultural property should be interpreted in the light of the principles derived from Article 23 of the Constitution of the Republic of Poland and from the perspective of the intentions expressed in the preamble to this Act. However, the instruments contained therein serve mainly to regulate trading in agricultural property and to exercise the powers of the state acting with the help of a trustee in the dominium sphere, acquiring the ownership of agricultural land from private entities. It is therefore concluded that the “family holding” defined in the Act does not correspond in its normative form to the constitutional model, and the statutory protection granted to it is only apparent and ineffective.
Integrated photonic FFT for photonic tensor operations towards efficient and high-speed neural networks
Authors: Ahmed Moustafa , Al-Hadeethi Yas , Bakry Ahmed , Dalir Hamed , Sorger Volker J.
Published: June 2020

The technologically-relevant task of feature extraction from data performed in deep-learning systems is routinely accomplished as repeated fast Fourier transforms (FFT) electronically in prevalent domain-specific architectures such as in graphics processing units (GPU). However, electronics systems are limited with respect to power dissipation and delay, due to wire-charging challenges related to interconnect capacitance. Here we present a silicon photonics-based architecture for convolutional neural networks that harnesses the phase property of light to perform FFTs efficiently by executing the convolution as a multiplication in the Fourier-domain. The algorithmic executing time is determined by the time-of-flight of the signal through this photonic reconfigurable passive FFT ‘filter’ circuit and is on the order of 10’s of picosecond short. A sensitivity analysis shows that this optical processor must be thermally phase stabilized corresponding to a few degrees. Furthermore, we find that for a small sample number, the obtainable number of convolutions per {time, power, and chip area) outperforms GPUs by about two orders of magnitude. Lastly, we show that, conceptually, the optical FFT and convolution-processing performance is indeed directly linked to optoelectronic device-level, and improvements in plasmonics, metamaterials or nanophotonics are fueling next generation densely interconnected intelligent photonic circuits with relevance for edge-computing 5G networks by processing tensor operations optically.
Experimental nanofocusing of surface plasmon polaritons using a gravitational field
Authors: Yan Zhiwei , Sheng Chong , Zhu Shining , Liu Hui
Published: June 2020

How to capture electromagnetic fields into sub-wavelength spatial scales has been a major challenge in nanophotonics, especially confining surface plasmon polaritons into regions as small as a few nanometers. Although various methods are proposed to achieve this goal, these methods require complex fabrication process. Here, we demonstrate experimentally the achievement of nanofocusing of surface plasmon polaritons with an intensity enhancement of three, using the simple structure with just pasting a sliver microwire on a sliver layer. And the designed structure has a well-defined gravitational field inspired by transformation optics. This simple design structure has applications to enhance light–matter interactions, such as nonlinear optical process and Raman scattering.
Critical review of quantum plasmonic models for finite-size media
Authors: Dorier Vincent , Guérin Stéphane , Jauslin Hans-Rudolf
Published: June 2020

We provide a critical analysis of some of the commonly used theoretical models to describe quantum plasmons in finite size media. We summarize the standard approach based on a Fano diagonalization and we show explicit discrepancies in the obtained results by taking the limit of vanishing coupling between the electromagnetic field and the material medium. We then discuss the derivation of spontaneous emission in a plasmonic environment, which usually relies on a Green tensor and is based on an incomplete identity. The effect of the missing terms is calculated in a one-dimensional model.
Two-dimensional Au & Ag hybrid plasmonic nanoparticle network: broadband nonlinear optical response and applications for pulsed laser generation
Authors: Nie Hongkun , Duan Wenchao , Liu Junting , Xia Haibing , Yang Kejian , Wang Fengqiu , Zhang Baitao , He Jingliang
Published: June 2020

Localized surface plasmon resonance (LSPR) of metallic nanoparticles (NPs) can generate and enhance the nonlinear optical (NLO) response and has been widely used in biosensing, optical bistability, optical switch, and modulator, surface-enhanced spectroscopies, etc. Here, the two-dimensional (2D) Au & Ag hybrid plasmonic NP network (Au & Ag HPNN) were synthesized by assembling Au and Ag NPs in ethanol solvent and transferring onto a CaF2 substrate. The frequency-domain finite element method (FEM) simulations were performed to explore their LSPR properties, demonstrating the broadband optical responses throughout visible, near-infrared and mid-infrared regions. The ultrafast carrier relaxation times were determined to be 3.9, 5.6, and 8.6 ps, while the nonlinear absorption coefficients were −1.12 × 104, −1.71 × 104, and −2.54 × 104 cm/GW, respectively, for the three wavelengths matching the LSPRs peaks at 1.0, 2.0, and 3.0 μm bands. Furthermore, passively Q-switched (PQS) solid-state lasers operating at 1062.8, 1990.8, and 2947 nm were demonstrated with 2D Au & Ag HPNN based saturable absorbers. This work not only reveals desirable ultrafast broadband NLO responses of 2D HPNN, but also provides a platform for investigating their applications in nanophotonic devices.
Reconfigurable topological waveguide based on honeycomb lattice of dielectric cuboids
Authors: Wang Xing-Xiang , Hu Xiao
Published: June 2020

We show that the photonic crystal (PhC) made of dielectric cuboids with their centers forming a honeycomb lattice is characterized by a

ℤ
2

${\mathbb{ℤ}}_{2}$

topological index when the longer sides of six cuboids point towards the center of hexagonal unit cell. While the C
6v
symmetry regarding the center of unit cell is preserved, the C
3 symmetry regarding honeycomb sites is broken, which opens a bandgap in the Dirac dispersion of honeycomb structure and induces a band inversion between p modes and d modes. Rotating cuboids around their individual centers closes the bandgap and reopens a trivial bandgap. We discuss that this feature can be exploited for realizing a reconfigurable topological waveguide.
Optical spin-dependent beam separation in cyclic group symmetric metasurface
Authors: Lee Yeon Ui , Ozerov Igor , Bedu Frédéric , Kim Ji Su , Fages Frédéric , Wu Jeong Weon
Published: June 2020

Cross-polarization scattering of a circularly polarized beam from nano-rod introduces a geometric phase to the outgoing beam with opposite circular polarization. By manipulating the spatial array of subwavelength nano-structure constituting metasurface, the geometric phase can be engineered to generate a variety of beam profiles, including vortex beam carrying orbital angular momentum via a process called spin-to-orbital angular momentum conversion. Here we introduce a cyclic group symmetric metasurface composed of tapered arc nano-rods and explore how azimuthal angular distribution of total phase determines the feature of spin-dependent beam separation. When scattered from a circular array of tapered arc nano-rods possessing varying width with a fixed length, a dynamical phase having non-constant azimuthal gradient is introduced to an incoming Gaussian beam. This leads to a spin-dependent beam separation in the outgoing vortex beam profile, which is attributed to an azimuthal angle dependent destructive interference between scatterings from two plasmonic excitations along the width and the length of tapered arc nano-rod. Relation of cyclic group symmetry property of metasurface and the generated vortex beam profile is examined in detail by experimental measurement and analysis in terms of partial-wave expansion and non-constant azimuthal gradient of total phase. Capability of spatial beam profiling by spin-dependent beam separation in vortex beam generation has an important implication for spatial demultiplexing in optical communication utilizing optical angular momentum mode division multiplexing as well as for optical vortex tweezers and optical signal processing employing vortex beams.
Accelerating photonic computing by bandwidth enhancement of a time-delay reservoir
Authors: Estébanez Irene , Schwind Janek , Fischer Ingo , Argyris Apostolos
Published: June 2020

Semiconductor lasers (SLs) that are subject to delayed optical feedback and external optical injection have been demonstrated to perform information processing using the photonic reservoir computing paradigm. Optical injection or optical feedback can under some conditions induce bandwidth-enhanced operation, expanding their modulation response up to several tens of GHz. However, these conditions may not always result in the best performance for computational tasks, since the dynamical and nonlinear properties of the reservoir might change as well. Here we show that by using strong optical injection we can obtain an increased frequency response and a significant acceleration in the information processing capability of this nonlinear system, without loss of performance. Specifically, we demonstrate numerically that the sampling time of the photonic reservoir can be as small as 12 ps while preserving the same computational performance when compared to a much slower sampling rate. We also show that strong optical injection expands the reservoir’s operating conditions for which we obtain improved task performance. The latter is validated experimentally for larger sampling times of 100 ps. The above attributes are demonstrated in a coherent optical communication decoding task.
Light-field and spin-orbit-driven currents in van der Waals materials
Authors: Kiemle Jonas , Zimmermann Philipp , Holleitner Alexander W. , Kastl Christoph
Published: June 2020

This review aims to provide an overview over recent developments of light-driven currents with a focus on their application to layered van der Waals materials. In topological and spin-orbit dominated van der Waals materials helicity-driven and light-field-driven currents are relevant for nanophotonic applications from ultrafast detectors to on-chip current generators. The photon helicity allows addressing chiral and non-trivial surface states in topological systems, but also the valley degree of freedom in two-dimensional van der Waals materials. The underlying spin-orbit interactions break the spatiotemporal electrodynamic symmetries, such that directed currents can emerge after an ultrafast laser excitation. Equally, the light-field of few-cycle optical pulses can coherently drive the transport of charge carriers with sub-cycle precision by generating strong and directed electric fields on the atomic scale. Ultrafast light-driven currents may open up novel perspectives at the interface between photonics and ultrafast electronics.
“What Is There to Talk About with These Women?”
Authors: Kosmos Iva
Published: June 2020

This article explores the highly heterogeneous social structure of female workers at two fish canneries: Kvarner on the island of Lošinj and Plavica on the island of Cres. The heterogenous workforce reflected certain characteristics of Yugoslav society. First, there was regional and ethnic diversity. Second, there were differences created by rapid modernization, especially between educated and uneducated women who possessed different types of knowledge and embodied different behavioral norms. The third set of differences between workers was based on a traditional patriarchal idea of female propriety which existed simultaneously alongside the socialist idea of a “working woman”. Lastly, the position of workers was also shaped through the tension between appreciation of industrial and physical labor in socialism and tourist imagination of the Adriatic coast. Workers’ narratives and the visual material testify to social hierarchies and differences, but also to negotiations of these positions and different affiliations, all of which depended on their various situations and interests. The stories from different factories also point to different possibilities of social relations, interactions and community building. While workers from Kvarner in Lošinj on occasions remained disintegrated, workers from Plavica on Cres traversed boundaries more easily and formed a close-knit network and community. This was due to the different working and living conditions in the two factories, including a policy of organized leisure and social events, which were a consequence of different periods in which the factories operated, different roles that they had in the local community and different factory management.
A 54-year record of changes at Chalaati and Zopkhito glaciers, Georgian Caucasus, observed from archival maps, satellite imagery, drone survey and ground-based investigation
Authors: Tielidze Levan G. , Svanadze David , Gadrani Lela , Asanidze Lasha , Wheate Roger D. , Hamilton Gordon S.
Published: June 2020

Individual glacier changes are still poorly documented in the Georgian Caucasus. In this paper, the change of Chalaati and Zopkhito glaciers in Georgian Caucasus has been studied between 1960 and 2014. Glacier geometries are reconstructed from archival topographic maps, Corona and Landsat images, along with modern field surveys. For the first time in the Georgian Caucasus aerial photogrammetric survey of both glacier termini was performed (2014) using a drone or Unmanned Aerial Vehicle, where high-resolution orthomosaics and digital elevation models were produced. We show that both glaciers have experienced area loss since 1960: 16.2±4.9 per cent for Chalaati Glacier and 14.6±5.1 per cent for Zopkhito Glacier with corresponding respective terminus retreat by ~675 m and ~720 m. These were accompanied by a rise in the equilibrium line altitudes of ~35 m and ~30 m, respectively. The glacier changes are a response to regional warming in surface air temperature over the last half century. We used a long-term temperature record from the town of Mestia and short-term meteorological observations at Chalaati and Zopkhito glaciers to estimate a longer-term air temperature record for both glaciers. This analysis suggests an increase in the duration of the melt season over the 54-year period, indicating the importance of summertime air temperature trends in controlling glacier loss in the Georgian Caucasus. We also observed supra-glacial debris cover increase for both glaciers over the last half century: from 6.16±6.9 per cent to 8.01±6.8 per cent for Chalaati Glacier and from 2.80±6.3 per cent to 8.53±5.7 per cent for Zopkhito Glacier.
Access to urban green spaces and environmental inequality in post-socialist cities
Authors: Csomós György , Farkas Jenő Zsolt , Kovács Zoltán
Published: June 2020

Access to urban green spaces and environmental inequalities are increasingly on the agenda in contemporary cities due to increasing density of people, widening social inequalities, and limited access to Urban Green Spaces (UGS). This is even so in post-socialist cities where recent urban sprawl and suburbanisation could be strongly linked to the scarcity of adequate green spaces in the inner-parts of cities. This paper examines the provision and accessibility of public green spaces in Debrecen, a second tier city in post-socialist Hungary, with applying a walking distance approach. Using GIS technology and socio-demographic data of residents the study assesses the availability and accessibility of green spaces in the city, and their social equity. According to research results the geographical distribution of UGS is very uneven in the city, some neighbourhoods lack public green spaces, while others are well-supplied. This is partly due to the natural environment and the post-WWII development of the city. Research findings show that the quality of residential green spaces is generally poor or very poor. Research also confirmed the widening environmental inequalities within the local society. New upmarket residential areas, where the wealthiest section of population reside are rich in high-quality (private) green spaces. Other lower-status neighbourhoods, including some of the socialist housing estates, suffer from the lack of good quality green spaces. Authors argue that environmental justice should be a core concept of city-planning considering not only the officially designated public green spaces, but also other forms of urban green (institutional, private etc.).
La sécurisation alimentaire en milieu rural : le cas de trois initiatives agricoles innovantes
Authors: Doyon Mélanie , Élie-Leonard Jessica , Arsenault-Hétu Camille
Published: June 2020

Le présent article porte sur la sécurisation alimentaire, c’est-à-dire qu’il s’intéresse aux processus par lesquels la sécurité alimentaire peut être atteinte ou, à tout le moins, améliorée. Plus spécifiquement, il s’intéresse à des initiatives agricoles cherchant à accroître la sécurité alimentaire en milieu rural. Pour ce faire, nous effectuons une analyse comparative de trois initiatives agricoles ayant vu le jour dans des milieux ruraux au Québec. L’objectif est de dégager des éléments de convergence et de divergence en ce qui a trait à la mise en place et au fonctionnement de tels projets, puis de discuter des avantages et inconvénients des trajectoires empruntées.
La participation sociale dans une communauté rurale au Québec : ce qui la facilité, selon les poins de vue de personnes engagées
Authors: Bonneau Marc-André , Dupéré Sophie
Published: June 2020

Cet article a pour objectif de présenter et de discuter certains facteurs facilitant la participation sociale, selon la perspective de personnes donnant de leur temps dans une petite communauté rurale. Cette implication est particulièrement importante pour les communautés situées dans une région dévitalisée sur les plans social et économique. Les résultats découlent d’une recherche qualitative effectuée auprès de 12 personnes engagées dans une communauté rurale située dans la région du Centre-du-Québec, au Québec. L’analyse thématique a fait ressortir six éléments facilitant la participation : 1) le besoin de revitaliser la communauté, 2) la présence de soutien municipal, 3) le dynamisme lié à la présence de nouveaux arrivants, 4) un climat de confiance, de réciprocité et d’entraide, 5) l’utilisation des réseaux sociaux et 6) un désir d’autonomie collective. À partir de ces résultats, nous discutons de l’importance de soutenir la participation sociale pour le développement socioéconomique de communautés rurales et pour la réduction des inégalités sociales.
Technological Aspects of Vegetable Oils Transesterification with Ethanol in the Presence of Metal Oxides
Authors: Melnyk Yuriy , Starchevskyi Roman , Melnyk Stepan
Published: June 2020

Transesterification of vegetable oil with ethanol in the presence of fine metal oxide particles as catalysts has been investigated. Zinc and nickel(II) oxides were shown to have the highest catalytic activity. In their presence, the conversion of sunflower oil triglycerides, after 150 min, reached 95.3 and 94.2 %, respectively. The optimal mass fraction of zinc oxide catalyst was found to be 0.25–0.31 %. In the presence of zinc oxide, with mass fraction of water in ethanol of 5 and 10 %, the conversion of triglycerides was 98.5 and 94.8 %, respectively.
Elaboration and Mechanical-Electrochemical Characterisation of Open Cell Antimonial-lead Foams Made by the “Excess Salt Replication Method” for Eventual Applications in Lead-acid Batteries Manufacturing
Authors: Hassein-Bey Amel Hind , Belhadj Abd-Elmouneïm , Gavrus Adinel , Abudura Salam
Published: June 2020

In this study, open cell 25 % antimony-lead alloy foams are fabricated for possible use to lighten thick plates of lead-acid batteries. A new inexpensive and simple variant of the salt replication process is developed and explored. Different morphology and shapes have been successfully obtained with “excess salt replication” method (abbreviated as ESR method). Best porosity of about 68 % is obtained with salt particles size of about 3 mm. SEM and EDXS investigation of the composite salt/antimony alloy before NaCl leaching revealed the presence of the lead oxides microfilm coating cell walls and becoming lead carbonates after salt removal. Uniaxial compressive behaviour of the resulting cellular materials is studied for foams with porosities between 45 % and 70 %, and salt grain size ranging between 2.5 and 5 mm. A higher plateau stress is reached compared to the results obtained in the literature working on the aluminium foams. The reproducibility of the process is proved along samples.
Itagüí: violencia estatal y violencia narcoparamilitar: una reflexión desde lo municipal sobre el monopolio de la violencia legitimada del Estado
Authors: Soto Aguirre Johnatan Andrés
Published: June 2020

Para explicar la existencia y el control que ejercen los grupos armados ilegales (gai) asociados al narcotráfico, son recurrentes argumentaciones sustentadas en ideas como la ausencia de Estado, la exclusión de servicios de seguridad y justicia o la referencia a las subculturas de la ilegalidad. El propósito de este texto es cuestionar los marcos interpretativos que suponen que la ausencia del Estado es precondición para el crecimiento del poder ilegal o que el fortalecimiento de la capacidad coercitiva del Estado implica su desaparición. Al aproximarnos a la relación entre el Estado, los gai y las prácticas y representaciones ciudadanas desde lo municipal encontramos un proceso continuo en el que los diferentes actores coexisten, interactúan y se reproducen en contextos híbridos de ilegalidad-legalidad. Itagüí es un claro ejemplo de la necesidad de pensar el monopolio de la violencia legitimada del Estado desde otros marcos explicativos, en los que se considere que la acción del Estado dependerá de las relaciones sociales contextualizadas, que no hay tal cosa como el poder general del Estado, y que es necesario identificar el conjunto de poderes particulares en lo local y su manera de amalgamarse para generar estructuras específicas de dominación.
Supporting Israel by Withholding Support from International Organizations: UNRWA and UNESCO in Trump’s Foreign Policy.
Authors: Espín Ocampo Julieta , Moreno Melgarejo Alberto , Navarro Zapata Estela
Published: June 2020

This paper analyses the steps undertaken by the Trump Administration against UNESCO and UNRWA,the former being a specialized organization, and the latter a specialized agency of the United Nations system, in order to pressure the Palestinian representatives to reach a final peace agreement with Israel that would go against the basic national aspirations of the Palestinian people and the international law. The article aims to highlight the consequences of this new political approach and how it directly affects the relationship between Palestinians and Israel.
Las Operaciones de Paz de las Naciones Unidas y los derechos humanos: el caso de la MINURSO en el Sáhara Occidental
Authors: Torrejón Rodríguez Juan Domingo
Published: June 2020

Las Operaciones de Paz de las Naciones Unidas pueden incluir en su mandato la posibilidad de supervisar la situación de los derechos humanos. Sin embargo, una de las excepciones destacadas es la Misión de las Naciones Unidas para el Referéndum en el Sáhara Occidental (MINURSO). Los derechos humanos se han convertido en una de las dimensiones más relevantes del conflicto del Sáhara Occidental. Por tanto, nuestro objetivo es analizar qué papel puede jugar la MINURSO en la observación de los derechos humanos en el Sáhara Occidental, así como formular algunas propuestas al respecto.