bluuebunny/crossref_metadata_2025 huggingface dataset:
Social Exclusion
Authors: Silver Hilary
Published: April 2019

Social exclusion is a multidimensional relational process of severing social ties, preventing access to institutions, denying opportunities for social participation, and impairing social cohesion and solidarity. It contributes to and is a result of poverty. Exclusion may be based upon cultural identities as well as on age, gender, sexuality, disability, poverty, unemployment, and other stigmatized categories. These numerous dimensions of exclusion may intersect or accumulate over time and space. Social exclusion has spatial manifestations that compound the effects of other dimensions. Insiders and institutions wall themselves in and wall others out, using spatial distance as well as social and symbolic boundaries to restrict access to resources and relationships. Mechanisms of spatial exclusion include displacement, confinement, and seclusion. Exclusion impedes the ability of outsiders to fulfill normatively prescribed social roles and to participate fully in society.
Spatial Justice
Authors: Didier Sophie , Quentin Aurélie
Published: April 2019

This entry locates spatial justice (i.e., the analysis of the spatial dimension of justice) in critical social sciences theory, and retraces the development of the concept from political philosophy to geography, planning, environmental, and development studies, as well as its connections to activism and global policy circles. Three major topical dimensions of the concept are identified, the urban, environmental justice, and global justice. An overview of the globalization of the concept outside of the Anglo‐American sphere is provided at the end of the entry.
Death and Life of Great American
C
ities, The
/J. Jacobs
Authors: Zukin Sharon
Published: April 2019

In
The Death and Life of Great American Cities
, Jane Jacobs defends the complexity, vitality, and diversity of older cities against the massive post‐World War II shift of resources and people to US suburbs. She praises mixed uses of space and describes the “sidewalk ballet” of storekeepers, neighbors, and strangers that keeps a street lively and safe at all hours of day and night. But she condemns the “great blight of dullness” imposed by bureaucratic urban planners and the modernist template of urban design. Their power, unchecked by community “self‐organization” and citizen participation, creates isolated “towers in the park,” empty green spaces, and unsafe streets. Although these ideas were rejected by dominant urban planning writers at the time, they influenced later generations of politicians and planners and became the key ideas underlying urban revitalization, historic and community preservation, and gentrification.
Toronto
Authors: Harold Joshua , Fong Eric
Published: April 2019

Toronto is the provincial capital of Ontario and Canada's largest city. The city of Toronto and the Greater Toronto Area (GTA) are regarded as English Canada's hub of commercial, economic, and cultural life. The GTA is also one of the most multiethnic and multicultural cities in North America and serves as the predominant immigrant‐receiving city in Canada.
Urban Ethnography
Authors: Imilan Walter , Marquez Francisca
Published: April 2019

Ethnography is a research method that involves a series of qualitative techniques of social investigation. At its core is fieldwork research and participant observation. Ethnography has played an important role in urban research by helping to reveal the different social groups that inhabit the city as well as the ways in which diversity achieves organization and claims its rights to the city. Ethnography has a history that extends back at least a hundred years, although it was not until recently that its practice extended beyond anthropology, the discipline that has cultivated it in a more systematic manner. The growing importance of subjective perspectives in the comprehension of social phenomena and the emergence of multiculturalism and hyper‐diversity in numerous contemporary societies, as well as the increasing importance of postcolonial tendencies of critical thought, have laid a foundation upon which ethnography operates as a powerful source for empirical work and theoretical formulation. Understanding the world from the “native's point of view,” ethnography provides knowledge that frequently contradicts general and universal interpretations, shedding light on the particularities and local configurations of social phenomena and bringing subjects to the fore through their practices and discourses.
Urbanism
Authors: Puchalski Vance Alan
Published: April 2019

Theories of urbanism describe how ecological and other factors lead to social and cultural patterns typically associated with city life. Urbanism as a theory gained prominence following the publication of Chicago School sociologist Louis Wirth's 1938 essay entitled “Urbanism as a Way of Life.” Wirth advanced ideas put forth by colleagues at the University of Chicago, classical European social theorists, and the groundbreaking American sociologist W. E. B. DuBois, and others, to theorize how the city influences its inhabitants' social interactions and behaviors, thus creating an urban “way of life.” Indeed, urbanism has had a lasting impact in the fields of sociology (especially urban sociology), urban studies, and urban planning. Subsequent generations of scholars have revised the theory, while practitioners have used its core principles to guide urban planning and design.
W
irth,
L
ouis
Authors: Kivisto Peter
Published: April 2019

Louis Wirth (1897–1952) was a member of the First Chicago School, primarily known for his work in urban sociology, race and ethnic relations, mass communication, the sociology of knowledge, and applied sociology. He combined a commitment to scholarship and social reform. He played a leadership role in the department during its last phase, a role cut short by his early death.
W
right,
F
rank
L
loyd
Authors: Crosas Armengol C.
Published: April 2019

Frank Lloyd Wright was a master of modern architecture and the greatest US architect of all time. His life's work encompasses a wide range of fields, from urban to interior design, marking significant milestones in the history of modern architecture and urbanism. With his prolific architectural work, in both the eastern and western USA, he had a strong influence on introducing modern language to domestic architecture. Moreover, his nonresidential buildings also became icons of modernity and authentic prototypes for future facility buildings. His social and territorial commitment led him to elaborate an outstanding urban theory developed mainly in his books
The Disappearing City
and
The Living City
and synthesized in his most famous urban work, Broadacre City.
Istanbul
Authors: Tepe Sultan
Published: April 2019

Istanbul is a unique global megacity due to its geographic location, rich history, and cultural heritage, as well as its representativeness of major contemporary urban and global issues. This entry describes how the long history of the city has shaped its multilayered identity, which can be seen in its architecture, public spaces, arts, and neighborhood communities. Then, in relation to current challenges of urban governance, the entry examines the ways Istanbul deals with rapid social, political, and economic transformations such as refugee migration, employment patterns, urban renewal projects, and ecological problems.
Megacity
Authors: Janoschka Michael
Published: April 2019

A megacity is typically defined as a metropolitan area with a population that exceeds 10 million inhabitants. The sheer size of megacities implicates administrative, political, economic, social, and environmental challenges, which have required specific attention from urban planners, architects, and engineers. However, the importance of megacities in an increasingly urbanized world goes beyond the simple numeric dimension. They also crystallize processes of globalization and new pathways for urban governance, resilience, sustainability, and technology, creating new and ever more complex dynamics and social relations that define the future trends for urban life on the planet.
Megalopolis
Authors: Ross Eric S.
Published: April 2019

The term “megalopolis” designates the largest type of urban conurbation. The concept was first proposed by the geographer Jean Gottmann and applied to the northeastern seaboard of the United States (Boston to Washington,DC). According to Gottmann's definition, a megalopolis is a polynuclear urban region consisting of a number of large metropolitan areas closely integrated through transportation and communications networks and having a minimum population of 25,000,000 people. The term has continued to be used since it was first proposed, but its definition has varied and it competes in the academic literature with other related terms.
M
oses,
R
obert
Authors: Ross Eric S.
Published: April 2019

Robert Moses (1888–1981) was an urban planner and public administrator who worked in various capacities for both the State of New York and New York City from the 1920s until the 1960s. He was the most powerful and influential American urban planner of the mid‐twentieth century. His career corresponded to the apogee of New York City as the largest city in the world. He was responsible for the planning and construction of a great deal of the metropolitan area's modern transportation infrastructure, public housing and urban renewal projects, and flagship projects such as the UN Headquarters, Lincoln Center, and the World's Fairs of 1939 and 1964.
Occupy (Movement)
Authors: Lorr Michael J.
Published: April 2019

The Occupy movement grew from the Occupy Wall Street idea of taking over public space in order to focus on the prevalence of contemporary inequality, as evidenced by the slogan “We are the 99 percent.” Occupy is akin, in spirit, to Guy Debord's
Society of Spectacle
and to Henri Lefebvre's idea of a right to the city. Occupy's greatest success was to shift public discourse away from austerity measures and toward conversations about inequality. But Occupy did not have the electoral success of the Tea Party movement – a similar movement on the right of the political spectrum. Much of Occupy has moved to online social media styled work, such as the circulation of memes via “Occupy the Democratic Party.”
Public City, The
Authors: Watson Sophie
Published: April 2019

Public space and the public realm are central to city imaginaries, everyday life, and the vitality of urban encounters. Urban theorists have theorized the public city from a range of different theoretical perspectives, from an emphasis on politics to sociality, to culture, and to materiality. This entry considers these different perspectives on the public city.
Urban Megaprojects
Authors: Jajamovich Guillermo , Kozak Daniel
Published: April 2019

Urban megaprojects are public or public–private operations of urban transformation defined as such based on their spatial scale, their cost, the planning models on which they are based, and/or the land value that they produce. The term “megaproject” was coined in the 1970s as part of a series of public and private initiatives in Canada. However, it is usual to find it retrospectively applied, in order to conceptualize projects that are prior to the emergence of the neologism.
Urban Utopia
Authors: Crommelin Laura
Published: April 2019

An urban utopia is a city that is both idealized and imagined. Many urbanists have designed urban utopias, either in theory or in practice, with mixed results. Famous examples include twentieth‐century city plans created by Ebenezer Howard, Le Corbusier, and Frank Lloyd Wright. While never fully implemented, each plan significantly influenced urban planning, albeit sometimes in unintended ways. More recent utopian visions from urban scholars like Sandercock and Harvey have focused on improving urban social processes rather than physical urban design. Utopian qualities can also be discerned in other recent urban trends, including the creative city and sustainability movements. Ultimately, these new trends are no more likely to achieve the impossible goal of creating an urban utopia than past attempts. However, they demonstrate the value of utopian thinking for urbanists, as it highlights current problems and offers a vision to motivate us to keep making our cities better.
L
e
C
orbusier
Authors: Atria Maximiano
Published: April 2019

Le Corbusier, Swiss (later French) architect and urban planner, was one of the most influential figures of the twentieth century, promoting the renovation of architecture and urbanism around the world. His books, writings, paintings, buildings, and urban plans are today a central focus of attention for researchers and historians of architecture, as well as a goal of pilgrimage for thousands of architects from the five continents. Some have compared his influence with that of Michelangelo, and certainly no other architect has provoked more controversies and debate, both during his lifetime and afterwards.
Cities in
N
orth
A
frica
Authors: Ali Amal K.
Published: April 2019

Cities of North Africa have grown as economic, political, and cultural centers along the coastlines of the Mediterranean Sea and Atlantic Ocean, and of the Valley and Delta of the Nile. They share the Middle Eastern culture, in which Islam is the dominant religion and Arabic is the official language. They were affected by European colonization, struggles for independence, conflicts during the postcolonial era, and globalization forces. Their rich history produces distinctive dual cities, with traditional
medinas
and modern areas. Representative cities include Algiers, Alexandria, Cairo, Casablanca, and Khartoum. They have been challenged by urban problems resulting from rapid population growth, climate change, civil wars, and terrorism.
Dakar
Authors: Hungerford Hilary
Published: April 2019

Dakar in Senegal emerged in the early 1900s as an important urban center in the French empire, and has retained its importance in postcolonial Senegal. Dakar is the capital and biggest city of Senegal and boasts lively cultural, political, and economic landscapes. Music and art are central features of Dakar's cultural scene, as are the centers of the country's political and economic power. Challenges facing Dakar include weak infrastructure and urban services such as trash, water, and sanitation; ensuring the economic vitality of the informal economy; governance and decentralization; and population growth.
K
inshasa
Authors: Beeckmans Luce
Published: April 2019

Kinshasa, the capital of the Democratic Republic of the Congo (DRC), grew in less than 100 years from some dispersed villages accommodating around 30,000 people to a megalopolis of more than 12 million inhabitants. On the African continent only Lagos (Nigeria) and Cairo (Egypt) have a larger urban population. Although the Belgian colonizer strictly controlled the growth of the city through urban planning interventions, since independence in 1960 the rapid urbanization process of the city is happening without any guidance from outside. Consequently, in the literature Kinshasa is often used to illustrate Africa's inventive responses to the enduring infrastructural crisis and the resilience of Kinshasa's inhabitants in particular.
Niger River/Sahelian Cities
Authors: Youngstedt Scott M.
Published: April 2019

The cities along the 1,000 km stretch of the Niger River that passes through the Sahel have been shaped by this remarkable geographic zone and its complex, millennium‐old history of civilizations and empires, trade, Islam, cultural diversity, French colonialism, and contemporary local, national, and global policies. Today Sahelian cities of the Niger River face many serious challenges, including climate disruption, insecurity, rapid growth, and land grabs by private foreign investors. This entry also presents profiles of two ancient cities that are part of the modern country of Mali – Gao and Timbuktu – and of a city that is essentially a product of French colonialism – Niamey, the capital of Niger.
Sanitation
Authors: Njeru Jeremia N.
Published: April 2019

With an estimated 60 percent of its urban residents lacking access to good sanitation, sub‐Saharan Africa is at the center of the global sanitation crisis. This entry describes the challenges of and prospects for solving urban sanitation problems in the region and highlights the factors that have contributed to the problems, including rapid population growth, colonial legacies of urban sanitation provision, and neoliberal restructuring. The entry also shows how the view, among sanitation advocates, that the provision of clean and safe shared facilities should be central to urban sanitation interventions in developing countries is reflected in some of the sanitation systems in sub‐Saharan Africa. How the adoption of appropriate technologies and the implementation of management regimes that employ tri‐sector partnerships – involving government, private, and voluntary sectors – are part of the solution to urban sanitation in the region is also examined.
Urban Agriculture
Authors: Masilela Calvin O.
Published: April 2019

Recent trends in development and planning literature seem to suggest that urban agriculture may be the panacea to ensuring urban food security and poverty alleviation in developing countries. This entry explores these trends within the context of people, places, and time. The entry asserts that urban agriculture needs to be looked at and evaluated in a way that goes beyond the trajectory of urban population growth trends to also include physical, political, and sociopolitical shock factors that undermine people's livelihood systems. It is argued here that for urban agriculture to be embraced as a strategy for overcoming food security needs, it will need to overcome structural and institutional factors that have bedeviled traditional agriculture in developing countries of Africa.
Urban Refugees
Authors: Subulwa Angela G.
Published: April 2019

Refugee populations in sub‐Saharan Africa are growing rapidly and face numerous legal, social, political, and economic challenges on a daily basis, particularly those living in Africa's cities. Historically, refugee policy operated under the assumption that refugees are situated in rural areas, as a review of major international agreements makes evident. Yet global and regional trends indicate significant increases in urban refugee populations that necessitate revisions of operational definitions and policies designed to serve and protect refugees in cities. The most significant challenges facing urban refugees fall into three broad categories: registration and documentation; access to urban services (housing, healthcare, education, and credit); and widespread xenophobia. Additionally, refugees in African cities often face many of the same challenges as the rest of the urban poor.
Urban Design History
Authors: Larice Michael
Published: April 2019

The history of urban design can be viewed and understood through three different conceptual filters.
Urban form patterns
refer to the basic structures of urban practice and each can be witnessed in different historical periods. These patterns include: organic; functional; cosmological; formal; picturesque; and cellular.
Historical urbanisms
focus on empirical urban design features associated with specific urban practices of different eras. Within these are found hundreds of different urbanisms that continue today, many years after they appeared. Lastly,
urban design movements
refer to specific practices under the guise of a manifesto or school of thought, many of these maturing between the late nineteenth century and the present. In the contemporary field of practice, a number of challenges and debates provide the impetus for continued urban design attention.
M
assey,
D
oreen
Authors: Skelton Tracey
Published: April 2019

Professor Doreen Massey (1944–2016) was a powerful, positive, critical academic‐activist who challenged and changed many aspects of geography, quite specifically through her work in regional and urban studies. She championed the significance and importance of space and place and decried the negative impacts of capitalism in everyday lives. Early in her career she channeled these ideas in the seminal text
Spatial Divisions of Labour
and latterly through a more theoretical lens in
For Space
. Massey's work and ideas were influential in a genuinely international context as she shared ideas with scholars, politicians, and people alike in different countries. As a stalwart actor at the Open University, a founding editor of
Soundings
, a journal of critical political and cultural debates, and a coauthor of the Kilburn Manifesto, Doreen Massey determinedly made academic theory and conceptualization meaningful and accessible beyond academia itself.
Cairo
Authors: Panetta Claire
Published: April 2019

This entry traces the history and development of Cairo, the capital of Egypt, from its founding in the seventh centuryceto its emergence as a global megacity in the twenty‐first century. Located 100 miles south of the Mediterranean coast and comprised of the governorates of Giza, Cairo, and Qalyubia, the city is estimated to have a population of 20–22 million. It has long been considered the cultural and political heart of the Middle East – in part owing to its rich history as a center of trade and commerce, religious practice, cultural development, and political negotiation. In the contemporary context, Cairo faces myriad infrastructural challenges, from waste management to vehicular congestion to public housing. Nevertheless, the city continues to thrive according to its own logic as a vibrant, functioning metropolis.
LaPlata
Authors: Segura Ramiro
Published: April 2019

This entry analyzes the urban history of the city of La Plata, a city planned to be the modern capital of the province of Buenos Aires at the end of the nineteenth century. The entry shows that the history of the city, its current situation, and its future constantly refer to the comparison between the “ideal city” as originally planned and the consolidation of the “real city” over more than a century of history.
And one more for the road: Commentary on the Special Issue on alcohol and eyewitness memory
Authors: Janssen Steve M.J. , Anne Michele
Published: April 2019

Studies examining the influence of alcohol intoxication have reported mixed findings on whether it impairs eyewitness memory. Although the studies in this Special Issue investigated different questions and tested different variables, the findings of these studies collectively provide insight into mechanisms and methodological issues that may explain the ambiguous findings of alcohol intoxication and eyewitness memory. In this commentary, we first describe the experimental studies of this Special Issue. We then discuss four mechanisms that could underlie those mixed findings (alcohol myopia, disinhibition, hypervigilance, and metacognitive processes at retrieval). Last, we address methodological issues that may have contributed to those ambiguous findings (i.e., alcohol intoxication levels, automatic processing of stimuli, sensitivity of dependent variables, and possible interactions with arousal) and provide suggestions for future research to address these issues.
In Situ Hybrid Aluminum Matrix Composites: A Review of Phase Transformations and Mechanical Aspects
Authors: Azarniya Amir , Azarniya Abolfazl , Abdollah‐zadeh Amir , Madaah Hosseini Hamid Reza , Ramakrishna Seeram
Published: April 2019

The growing industrial needs for the development of strong load‐bearing materials by powder metallurgy and casting technologies has led to recent progress in the synthesis of in situ hybrid aluminium matrix composites (AMCs). Unlike their conventional counterparts, this class of engineering materials and their physicomechanical properties are sparsely investigated with no satisfactorily systematic approach and are not reviewed up to now. This is why providing an overview summarizing the formation mechanisms of in situ phases and mechanical properties of hybrid AMCs can systematically guide the research path in this field. The present review strives to categorize hybrid AMCs based on their dominant in situ formed reinforcements and draw a comparison between different fabrication methods and used starting materials. Finally, the present challenges and potential solutions are addressed both from scientific and technological aspects.
Initial Irreversible Losses and Enhanced High‐Temperature Performance of Rare‐Earth Permanent Magnets
Authors: Xia Wei , He Yangkun , Huang Houbing , Wang Hui , Shi Xiaoming , Zhang Tianli , Liu Jinghua , Stamenov Plamen , Chen Longqing , Coey John Michael David , Jiang Chengbao
Published: April 2019

There is an increasing demand for permanent magnets with high‐temperature stability. Normally, the magnets are heat treated above the operating temperature range to saturate the irreversible losses, thereby producing magnets that are stable, but with significantly degraded performance. In addition, uncertainty about the losses in differently shaped magnets causes difficulties for efficient magnetic circuit design. The variation of the initial irreversible losses with magnet shape, hysteresis loop, and operating temperature is presented here. Losses are not associated with thermal demagnetization of the whole magnet, but the damage is concentrated in an outer surface “skin” at the pole surfaces, where the demagnetizing field is nonuniform. The initial irreversible remanence loss at room temperature can be predicted as the product of the slope of the high‐temperature magnetization curvek(T) and the effective demagnetizing factor . Heat treatment with the vulnerable surfaces in contact with soft iron slabs moves the skin out of the permanent magnet and reduces the irreversible remanence loss by 30% or more, potentially improving the performance of permanent‐magnet motors, generators, bearings, and thrusters. The results deepen the understanding of the magnetism of irreversible losses and will guide the applications of permanent magnets at higher temperatures.
Highly Efficient Indoor Organic Photovoltaics with Spectrally Matched Fluorinated Phenylene‐Alkoxybenzothiadiazole‐Based Wide Bandgap Polymers
Authors: You Young‐Jun , Song Chang Eun , Hoang Quoc Viet , Kang Yoonmook , Goo Ji Soo , Ko Doo‐Hyun , Lee Jae‐Joon , Shin Won Suk , Shim Jae Won
Published: April 2019

The unique electro‐optical features of organic photovoltaics (OPVs) have led to their use in applications that focus on indoor energy harvesters. Various adoptable photoactive materials with distinct spectral absorption windows offer enormous potential for their use under various indoor light sources. An in‐depth study on the performance optimization of indoor OPVs is conducted using various photoactive materials with different spectral absorption ranges. Among the materials, the fluorinated phenylene‐alkoxybenzothiadiazole‐based wide bandgap polymer—poly[(5,6‐bis(2‐hexyldecyloxy)benzo[c][1,2,5]thiadiazole‐4,7‐diyl)‐alt‐(5,50‐(2,5‐difluoro‐1,4‐phenylene)bis(thiophen‐2‐yl))] (PDTBTBz‐2Fanti)‐contained photoactive layer—exhibits a superior spectrum matching with indoor lights, particularly a light‐emitting diode (LED), which results in an excellent power absorption ratio. These optical properties contribute to the state‐of‐the‐art performance of the PDTBTBz‐2Fanti:[6,6]‐phenyl‐C71 butyric acid methyl ester (PC71BM)‐based OPV with an unprecedented high power‐conversion efficiency (PCE) of 23.1% under a 1000 lx LED. Finally, its indoor photovoltaic performance is observed to be better than that of an interdigitated‐back‐contact‐based silicon photovoltaic (PCE of 16.3%).
Improving Charge Transport via Intermediate‐Controlled Crystal Growth in 2D Perovskite Solar Cells
Authors: Gao Liguo , Zhang Fei , Xiao Chuanxiao , Chen Xihan , Larson Bryon W. , Berry Joseph J. , Zhu Kai
Published: April 2019

Reduced‐dimensional hybrid perovskite semiconductors have recently attracted significant attention due to their promising stability and optoelectronic properties. However, the issue of poor charge transport in 2D perovskites limits its application. Here, studies on intermediate‐controlled crystal growth are reported to improve charge carrier transport in 2D perovskite thin films. It is shown that the coordination strength of solvents with perovskite precursor affects the initial state of intermediate phase formation as well as the subsequent perovskite layer growth. Tuning the solvent composition with a mixture (5:5) of dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO) leads to the growth of highly orientated 2D perovskite films with much‐improved optoelectronic properties (faster transport by ≈50x, longer carrier lifetime by ≈4x, and lower defect density by ≈30x) than the film prepared with pure DMF. Consequently, perovskite solar cells based on DMF/DMSO (5:5) show >80% efficiency improvement than the devices based on pure DMF.
Giant Barocaloric Effect at the Spin Crossover Transition of a Molecular Crystal
Authors: Vallone Steven P. , Tantillo Anthony N. , dos Santos António M. , Molaison Jamie J. , Kulmaczewski Rafal , Chapoy Antonin , Ahmadi Pezhman , Halcrow Malcolm A. , Sandeman Karl G.
Published: April 2019

The first experimental evidence for a giant, conventional barocaloric effect (BCE) associated with a pressure‐driven spin crossover transition near room temperature is provided. Magnetometry, neutron scattering, and calorimetry are used to explore the pressure dependence of the SCO phase transition in polycrystalline samples of protonated and partially deuterated [FeL2][BF4]2 [L = 2,6‐di(pyrazol‐1‐yl)pyridine] at applied pressures of up to 120 MPa (1200 bar). The data indicate that, for a pressure change of only 0–300 bar (0–30 MPa), an adiabatic temperature change of 3 K is observed at 262 K or 257 K in the protonated and deuterated materials, respectively. This BCE is equivalent to the magnetocaloric effect (MCE) observed in gadolinium in a magnetic field change of 0–1 Tesla. The work confirms recent predictions that giant, conventional BCEs will be found in a wide range of SCO compounds.
A Colorimetric Multifunctional Sensing Method for Structural‐Durability‐Health Monitoring Systems
Authors: Im Healin , Hong Seongin , Lee Yunsu , Lee Hanseung , Kim Sunkook
Published: April 2019

A colorimetric multifunctional phototransmittance‐based structural durability monitoring system is developed. The system consists of an array with four indium gallium zinc oxide (IGZO)‐based phototransistors, a light source at a wavelength of 405 nm through a side‐emitting optical fiber, and pH‐ and Cl‐selective color‐variable membranes. Under illumination at the wavelength of 405 nm at corrosion status, the pH‐ and Cl‐responsive membrane, showing a change in their color, generates a change in the intensity of the transmitted light, which is received by the phototransistor array in the form of an electrical current. Ids and R (Ids/IpH 12) are inversely proportional to the pH, which ranges from 10 to 12. When the pH drops from 12 to 10, the magnitude of Ids and R increases to ≈103. In the case of Cl detection, Ids and R (Ids/ICl 0 wt%) increase nearly 50 times with an increase in Cl concentration of 0.05 wt%, and when the Cl concentration reaches 0.30 wt%, Ids and R increase to ≈103 times greater. This multifunctional colorimetric durability sensing system demonstrates considerable potential as a novel smart‐diagnostic tool of structural durability with high stability, high sensitivity, and multifunction.
Alcohols Assisted Hydrothermal Synthesis of Defect‐Rich MoS2 and Their Applications in Humidity Sensing
Authors: Leng Xiaohui , Wang Yiming , Wang Fei
Published: April 2019

The influence of different alcohols on hydrothermal synthesis of molybdenum disulfide (MoS2) has been studied. X‐ray diffraction and scanning electron microscope results show that MoS2 synthesized in water and water/polyethylene glycol exhibits good flower‐like crystallization while in ethanol/water, ethylene glycol/water, and glycerol/water, the MoS2 shows a smaller size of 3D flower structure and larger layer distance. Strong absorbance peaks in Fourier‐transform infrared spectroscopy and Raman spectra indicate oxygen doping in MoS2. These defects from oxygen doping induce a good sensitivity to water vapor in the environment. A lower hydrothermal temperature (i.e., 180 and 200 °C) results in these defect rich MoS2 and benefits the humidity sensing performance.
Low Threshold Polariton Lasing from a Solution‐Processed Organic Semiconductor in a Planar Microcavity
Authors: Rajendran Sai Kiran , Wei Mengjie , Ohadi Hamid , Ruseckas Arvydas , Turnbull Graham A. , Samuel Ifor D. W.
Published: April 2019

Organic semiconductor materials are widely studied for light emission and lasing due to their ability to tune the emission wavelength through chemical structural modification and their relative ease of fabrication. Strong light–matter coupling is a promising route toward a coherent light source because it has the potential for polariton lasing without population inversion. However, the materials studied so far have relatively high thresholds for polariton lasing. Here, the suitability of pentafluorene for strong coupling and low threshold polariton lasing is reported. A protective buffer layer is used to reduce degradation during fabrication and the lasing threshold is lowered using negative detuning to maximize radiative decay. A low threshold of 17 µJ cm−2, corresponding to an absorbed energy density of 11.7 µJ cm−2, is obtained. This study shows that pentafluorene is an attractive material for polariton lasing and will assist in the development of low threshold electrically pumped lasing from polariton devices.
Donor Amine Salt‐Based Continuous in situ‐Product Crystallization in Amine Transaminase‐Catalyzed Reactions
Authors: Hülsewede Dennis , Dohm Jan‐Niklas , von Langermann Jan
Published: April 2019

The unfavorable reaction equilibrium of transaminase‐catalyzed reactions is a major challenge for the efficient biocatalytic synthesis of chiral amines. In this study the synthetic utilization of a salt‐based, continuous in situ‐product crystallization is described to overcome the thermodynamic limit in amine transaminase‐reactions using only the commonly used amine donor isopropylamine. The simultaneous dissolution of isopropylammonium 3,3‐diphenylpropionate (donor salt) in combination with the crystallization of the product salt facilitates a thermodynamic shift of the continuous amine transaminase‐catalyzed reaction. The main process necessity is a lower product salt solubility in comparison to the applied donor salt. This concept facilitates a stoichiometric use of isopropylamine in combination with a significantly lowered concentration of the amines in solution.

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Rhodium(II)‐Catalyzed Intramolecular Transannulation of 4‐Methoxycyclohexa‐2,5‐dienone Tethered 1‐Sulfonyl‐1,2,3‐triazoles: Synthesis of Azaspiro[5.5]undecane Derivatives
Authors: Zhu Cheng‐Zhi , Wei Yin , Shi Min
Published: April 2019

A Rh(II)‐catalyzed denitrogenative intramolecular transannulation using 4‐methoxycyclohexa‐2,5‐dienone tethered N‐sulfonyl‐1,2,3‐triazoles as substrates has been developed, affording diversified 3‐methoxy‐1‐tosyl‐1‐azaspiro[5.5]undecanes in moderate to good yields under mild conditions. This new synthetic method proceeded through an oxonium ylide generated from trapping a rhodium(II)‐carbene by methoxy group, a methoxy group migration, and C−N bond formation, providing an interesting synthetic strategy for the construction of spirocyclic frameworks.

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Co3O4 Supraparticle‐Based Bubble Nanofiber and Bubble Nanosheet with Remarkable Electrochemical Performance
Authors: Huang Jun , Xiao Yingbo , Peng Zhongyou , Xu Yazhou , Li Longbin , Tan Licheng , Yuan Kai , Chen Yiwang
Published: April 2019

Hollow nanostructures based on transition metal oxides (TMOs) with high surface‐to‐volumetric ratio, low density, and high loading capacity have received great attention for energy‐related applications. However, the controllable fabrication of hybrid TMO‐based hollow nanostructures in a simple and scalable manner remains challenging. Herein, a simple and scalable strategy is used to prepare hierarchical carbon nanofiber (CNF)‐based bubble‐nanofiber‐structured and reduced graphene oxide (RGO)‐based bubble‐nanosheet‐structured Co3O4 hollow supraparticle (HSP) composites (denoted as CNF/HSP‐Co3O4 and RGO/HSP‐Co3O4, respectively) by solution self‐assembly of ultrasmall Co3O4 nanoparticles (NPs) assisting with polydopamine (PDA) modification. It is proved that the electrochemical performance of Co3O4 NPs can be greatly enhanced by the rationally designed nanostructure of bubble‐like supraparticles combined with carbon materials as excellent electrodes for supercapacitors. The favorable structure and composition endow the hybrid electrode with high specific capacitance (1435 F g−1/1360 F g−1 at 1 A g−1/5 mV s−1) as well as fantastic rate capability. The asymmetric supercapacitors achieve an excellent maximum energy density of 51 W h kg−1 and superb electrochemical stability (92.3% retention after 10 000 cycles). This work suggests that the rational design of electrode materials with bubble‐like superstructures provides an opportunity for achieving high‐performance electrode materials for advanced energy storage devices.
Defining features of age‐specific fertility and seed quality in senescing indeterminate annuals
Authors: Dogra Harshita , Dani K. G. Srikanta
Published: April 2019

Premise of the Study

A trade‐off between fertility and offspring viability underpins plant reproductive response to sub‐optimal environmental conditions. Senescence involves internal resource limitation, and it is a sub‐optimal body condition. We tested if senescence affects age‐specific fertility and seed viability (quality) in indeterminate annuals.

Methods

Fertility in individual pods on the monopodial indeterminate inflorescence of Arabidopsis thaliana and its big‐seeded relative Brassica nigra was quantified. The reproductive phase was divided into three phases: (1) early‐senescence (initial flowers) (2) mid‐senescence and (3) late‐senescence (wilting leaves). Seed‐viability probability as a function of pod position on the inflorescence (a proxy for parent's age) and seed position within pod was verified by germination tests in Brassica and then analysed using a binomial logistic regression model.

Key Results

Age‐specific fertility increased gradually, peaked, and then declined significantly during senescence in Arabidopsis and Brassica. Acropetal size distribution of rosette leaves was similar to that of pods (age‐specific fertility) in Arabidopsis. Seeds positioned closest to stigma tended to be heavier and more viable than others in highly fertile pods, characteristic of mid‐senescence phase in Brassica. Pod position (parent's age) was a significant predictor of seed‐viability probability or seed quality, which improved in old and senescing Brassica.

Conclusions

High viability probability of seeds produced in low‐fertility pods during late‐senescence phase suggests weakening of maternal control over seed‐size optimization (bigger, fewer, and better seeds) in internally resource‐depleted older parent plants. Proximity to stigma can increase seed quality. The unexpected increase in fertility and seed viability during early‐senescence phase is likely due to highly conserved developmental constraints on leaf and pod phenotype. Indeterminate annuals can shed light on fertility, offspring quality and senescence relationships in all plants that reproduce sexually and indeterminately.
Capuchin monkeys (Sapajus[Cebus]apella) play Nash equilibria in dynamic games, but their decisions are likely not influenced by oxytocin
Authors: Smith Mackenzie F. , Leverett Kelly L. , Wilson Bart J. , Brosnan Sarah F.
Published: April 2019

Comparative approaches to experimental economics have shed light on the evolution of social decision‐making across a range of primate species, including humans. Here we replicate our previous work looking at six pairs of capuchin monkeys' (Sapajus [Cebus] apella) responses to scenarios requiring both coordination (Assurance Game) and anti‐coordination (Hawk‐Dove Game). This then provides a foundation for assessing their responses to two additional games, one with a scenario of beneficial cooperation with a temptation to defect (Prisoner's Dilemma) and one with an environment requiring changing strategies within short temporal proximity (Alternating Economic Game). We additionally explored the effects of exogenous oxytocin on decision‐making. Oxytocin did not affect decisions in any of our games. Results from the first two games largely replicated our previous findings. Responses to the Prisoner's Dilemma were more varied than was seen in previous games, with pairs respectively cooperating, defecting, and failing to establish stable strategies. Such variability indicates that this game may be a good assay for individual differences in social decision‐making. Finally, capuchins were able to flexibly switch between their previously established strategies within each of the different games, even when the games were presented within the same session, requiring strategy adjustments within short temporal proximity. These results build on earlier findings showing that capuchins can alter decision‐making strategies as the context demands, which is likely essential for decision‐making in naturally occurring contexts.
Sauerstoffentwicklungsreaktion an Kohlenstoffkanten: Aktivitätsentwicklung und Struktur‐Eigenschafts‐Beziehungen, untersucht anhand polyzyklischer aromatischer Kohlenwasserstoffe
Authors: Lin Yangming , Lu Qing , Song Feihong , Yu Linhui , Mechler Anna K. , Schlögl Robert , Heumann Saskia
Published: April 2019

Die reichlich vorhandenen oberflächenchemischen Informationen und Kantenstrukturen von Kohlenstoffmaterialien haben ein enormes Interesse auf dem Gebiet der Katalyse geweckt. Für die Sauerstoffentwicklungsreaktion (OER) wurden die Kanteneffekte von Kohlenstoffmaterialien aufgrund verschiedener nebeneinander existierender Kantenkonfigurationen selten im Detail untersucht. Zudem besteht eine Kontroverse zwischen Kohlenstoffkorrosion und Kohlenstoffkatalyse. zwischen Kohlenstoffkorrosion und Kohlenstoffkatalyse selten im Detail untersucht. Hier werden die genauen Rollen der gemeinsamen Kohlenstoff‐Aktivkanten in der OER unter Verwendung von polyzyklischen aromatischen Kohlenwasserstoffen (PAKs) mit spezifischen Konfigurationen (Zickzack und Sessel) als Modelltestmoleküle mit dem Fokus auf Struktur‐Eigenschafts‐Beziehungen untersucht. Zickzackkonfigurationen von PAKs wurden so bestimmt, dass sie eine hohe Aktivität für die OER und zugleich eine gute Stabilität bei einer angemessenen Spannung aufweisen. Es wurde mit einem TOF‐Wert von 0.276 s−1 in 0.1 m KOH gearbeitet. Die katalytische Aktivität von Kohlenstoffkantenstellen konnte durch die Erweiterung ihrer π‐Konjugationsstruktur auf molekularer Ebene weiter effektiv reguliert werden.
Vibrational Signatures of Chirality Recognition Between α‐Pinene and Alcohols for Theory Benchmarking
Authors: Medel Robert , Stelbrink Caroline , Suhm Martin A.
Published: April 2019

Chirality recognition between largely rigid molecules can be applied as a benchmark for the description of intermolecular forces by theoretical methods, because one constituent is merely mirrored, so other deficits of the methods such as neglect of anharmonicity should mostly cancel. To test this approach, mixed OH⋅⋅⋅π‐bridged dimers between the enantiomers of the bicyclic monoterpene α‐pinene and the chiral secondary alcohols borneol, α‐fenchol, isopinocampheol, and 1‐phenylethanol were formed in a supersonic jet and probed by linear FTIR spectroscopy. With borneol and α‐fenchol, pronounced shifts in the hydroxyl stretching frequencies upon exchange of the handedness are observed. From three tested density functionals, only B3LYP‐D3(BJ) is able to predict these diastereomeric shifts in a satisfactory manner, while M06‐2X and ωB97X‐D fall short.
Heterodiatomic Multiple Bonding in Group 13: A Complex with a Boron–Aluminum π Bond Reduces CO2
Authors: Hofmann Alexander , Légaré Marc‐André , Wüst Leonie , Braunschweig Holger
Published: April 2019

Heterodiatomic multiple bonds have never been observed within Group 13. Herein, we disclose a method that generates [(CAAC)PhB=AlCp3t] (1), a complex featuring π bonding between boron and aluminum through the association of singlet fragments. We present the properties of this multiple bond as well as the reactivity of the complex with carbon dioxide, which yields a boron CO complex via an unusual metathesis reaction.
Gold(I)‐Catalyzed Cascade Cyclization Reactions of Allenynes for the Synthesis of Fused Cyclopropanes and Acenaphthenes
Authors: Ikeuchi Takaya , Inuki Shinsuke , Oishi Shinya , Ohno Hiroaki
Published: April 2019

A gold‐catalyzed reaction of phenylene‐tethered allenynes with benzofurans gave 1‐(naphth‐1‐yl)cyclopropa[b]benzofuran derivatives, whereas the reaction of 1‐allenyl‐2‐ethynyl‐3‐methylbenzene derivatives in the absence of benzofurans gave acenaphthenes in good yields. These results can be rationalized by nucleophilic attack of the alkyne moiety on an activated allene to form a vinyl cation intermediate.
Degradation of hazardous organic dyes with solar‐driven advanced oxidation process catalyzed by the mixed metal–organic frameworks
Authors: Farrokhi Alireza , Feizpour Fahimeh , Asaadzadeh Maryam
Published: April 2019

phosphonate‐based bimetallic metal‐ organic frameworks, namely STA‐12(M1, M2) (M1, M2 = Mn, Fe, Co), show photocatalytic activity for the degradation of Rhodamine B (RhB) and Methylene blue (MB) from aqueous solution under natural sunlight irradiation. The degradation of the dyes, appears to be faster with STA‐12(Fe, Mn) than other synthesized MOFs. Thus, photo‐Fenton oxidative discoloration of dyes has been studied by H2O2 catalyzed with the STA‐12(Fe, Mn). The process is first order with respect to dyes and the synergistic index in the STA‐12(Fe, Mn)/sunlight/H2O2system reached as high as 472%. Mineralization of dyes was discussed by spectroscopic and TOC measurement. Besides, the efficiency of STA‐12(Fe, Mn) used in photocatalytic process was attentively investigated through the characterization of reactive radicals, the stability and reusability of the photocatalyst, also the effect of operational parameters such as H2O2 dosage, solution pH and initial dye concentration. This work demonstrates the first example of facilitating photo‐Fenton‐like excitation of H2O2 via phosphonate based mixed metal organic frameworks as photocatalysts and explained a new opportunity for solar‐induced AOP environmental remediation and protection.
Effect of electron‐beam irradiation followed by annealing on the physical properties of poly(vinyl alcohol)–chitosan blend films at different weight ratios
Authors: Jahanabadi Robabe , Sheikh Nasrin , Mahdavi Hamid , Bagheri Rouhollah
Published: April 2019

The aim of this study was to examine the effect of electron‐beam irradiation followed by annealing on the physical properties of poly(vinyl alcohol) (PVA)–chitosan (CS) blend films. Solution‐cast films containing various ratios of polymers were exposed to irradiation doses of 26, 39, and 52 kGy at room temperature and then annealed at 100 °C. The results show that at all doses, with an increase in the weight ratio of CS, the gel content of the samples decreased, and the water absorption of the samples increased. The irradiation dose ranged from 26 to 39 kGy; this led to an increased gel content and a decreased degree of swelling in the samples. However, at 52 kGy, an increase in the amount of swelling was observed. X‐ray diffraction analysis and scanning electronic microscopy images of the samples revealed that the increase in the irradiation dose reduced the crystallinity and increased the surface heterogeneity, respectively. The tensile strength of the blends decreased with decreasing PVA–CS weight ratio. This property of the samples increased with dose from 26 to 39 kGy and decreased at 52 kGy. The elongation at break of the samples decreased with both an increase in the irradiation dose and a decrease in the CS content. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47820.