bluuebunny/crossref_metadata_2025 huggingface dataset:
De vroege geschiedenis van de (lokale) bestuurswetenschappen: Adriaan Buriks en het democratisch gemeentebeheer
Authors: Reussing Rik
Published: October 2018

The early history of Dutch (local) administrative sciences: Adriaan Buriks and democratic municipal government

Debates about the quality of local democracy are not new. This was also the case 100 years ago. In 1918 the ground-breaking dissertation of Adriaan Buriks on democratic municipal government was published in the Netherlands. In his dissertation Buriks proposed a radical democratic reform of Dutch municipal government by adopting the new system of ‘commission government’ from the US. That is a system of city government in which (almost) all city authority functions are concentrated in a small commission. The commission is organized in such a way that each member of the commission is the head of a city government department, every member is chosen by the population of the whole city and the exercise of authority is controlled by the whole population. The essay describes the remarkable life of this social revolutionary and municipal law expert. It goes on to discusses the dissertation through an introduction on the central issue of democratic municipal government, a description of the government systems of the US before and after the American Revolution of 1787, a description of the new system of ‘commission government’ and his proposal to adopt the new system in the Netherlands. The essay is closed by the author’s reflection on how the dissertation was received and its impact.
The Theory of the Growth of the Firm over 60 Years: From Where We Came and Where We Are Going
Authors: Di Petta Arnaldo , De Gouveia Luciana Orozco , Bozzo Andrea Luísa , Gonçalves Marcelo Neves
Published: October 2018

Objective: Our main objective is to present a retrospective of Penrose’s work, over the last 60 years, summarizing trends and the existence of opportunities for future research on the subject. Method: From revisions that have been published in recent years in high impact international journals, we developed a new review presenting a Theory of Growth of the Firm. Originality and Relevance: This work is original due to the inexistence, in Brazil, of a similar study. It is relevant because the book “The Theory of Firm Growth” is a work that has been influencing theoretical and managerial development since its launch. Nearing 60 years, the subjects covered in the book and the way they are treated still arouse the interest of scholars, serving as a reference for the theoretical development of business schools. Results: We concluded that there is a need for new research on the different modes of growth of companies and also on other ways of measuring this growth. The tendency is not to use a strict interpretation of resource characteristics from the perspective of the Resources Based View (RBV), and it is necessary to better understand how companies can grow in a global market, embedded in an increasingly competitive environment. Contributions: With this work we contribute to the academic debate, synthesizing from where we came from the original work by Penrose and consolidating the lines of research in which this theory can still have influence. This implies knowledge of new corporate realities and the use of different growth models. Likewise, a more versatile use of resources should be considered in a reality of interaction between small and large companies, leveraging the growth of the business ecosystem.
Aprendizagem experiencial na formação de gestores socioambientais
Authors: Brasil Walterlina , Arrolho Solange , Simão Berenice
Published: October 2018

Trata-se da experiência proporcionada durante um curso de Pós-Graduação Lato Sensu para formação de lideranças na gestão socioambiental, onde se estabeleceu como base metodológica a Aprendizagem Experiencial, nos termos de Freire (1987), Lizeo (2003) e Kolb (1984). O artigo analisa o uso dessa abordagem no curso, e quais contribuições oferecem àqueles que se disponham a efetivar formação de gestores socioambientais. Anota-se que o curso foi estruturado com base na teoria de sistemas socioecológicos complexos, buscando contribuir com a formação de lideranças para a Amazônia brasileira. Este marco teórico é importante porque está associado à escolha metodológica para a formação oferecida, convertendo-se no eixo da proposta que abre espaço para experiências oferecidas a partir da Aprendizagem Experiencial. A análise pode subsidiar outros processos semelhantes, aperfeiçoados com base na reflexão sobre o método para a aprendizagem e identificando a efetividade dessa prática na formação profissional.
Interfaces dos saberes ambientais: complexidade e educação política difusa
Authors: Barros Antonio Teixeira de
Published: October 2018

Analisa as interfaces dos saberes ecológicos com a educação ambiental e política, ambas entendidas como educação difusa, que se realiza no âmbito das relações sociais e educativas do cotidiano, relevantes do ponto de vista da conversação civil e da cidadania. Ressalta a visão de interdisciplina e complexidade do ambientalismo e sua dimensão educativa e política. Tanto a educação como o ambientalismo constituem campos convergentes na dimensão de (re)construção e (re)produção simbólica da realidade e de suas estruturas políticas. Além disso, a educação ambiental é entendida como instrumento para formar cidadãos para atuarem na sociedade, assumindo a responsabilidade pelo ambiente natural, a cultura local e o meio social.
The logic of the valorization of natural resources in Brazil: historical relationship between the electricity sector and the mining industry in the Amazon
Authors: Carvalho André Cutrim , Pimentel Cleyton Alves Candeira
Published: October 2018

O presente artigo procura traçar uma análise do ponto de vista histórico para, posteriormente, compreender a relação econômica entre os fenômenos históricos ocorridos no Governo Militar e, recentemente, no governo do ex-presidente, Luiz Inácio Lula da Silva. Nestas condições, o artigo procura concentrar sua análise no entendimento da relação entre o setor elétrico e o setor mineral na Amazônia brasileira, principalmente na Amazônia Oriental. A principal conclusão é que a Amazônia brasileira e Oriental que impacta (in)diretamente no desenvolvimento do setor elétrico e no setor mineral do país. Contudo, há espaço para a promoção de uma conexão muito mais íntima entre esses setores e, é claro, um potencial intenso para a exploração de reservas minerais, inclusive, com a perspectiva de verticalização da produção e geração de emprego, renda e agregação de valor para a economia nacional e regional.
Estratégias e formas de reprodução social na agricultura familiar da Fronteira Oeste do Rio Grande do Sul
Authors: Troian Alessandra , Breitenbach Raquel
Published: October 2018

O papel e a importância da agricultura familiar ganhou destaque nas duas últimas décadas. A valorização se deu tanto em nível de governo, quanto pela academia, passando a agricultura familiar a fazer parte da agenda política do Brasil como uma estratégia de desenvolvimento rural. Neste sentido, reconhecendo a sua heterogeneidade, o presente estudo objetiva analisar a agricultura familiar da região da Fronteira Oeste do Rio Grande do Sul, destacando o surgimento, as principais características e a dinâmica de reprodução social. Metodologicamente utilizou-se a revisão bibliográfica. Identificou-se que a agricultura familiar, embora sempre se fizesse presente na região, ganha destaque a partir dos 1990, com a implantação dos assentamentos rurais, o reconhecimento acadêmico da categoria e com as políticas públicas. Entre as estratégias de reprodução social da agricultura familiar local destaca-se a diversificação de cultivos, a cooperação e o acesso a políticas públicas, tanto para crédito quanto de comercialização.
Etnoconservação e história ambiental para um novo modelo conservacionista do século XXI
Authors: Barbosa José Aécio Alves , Aguiar José Otávio
Published: October 2018

Diante do cenário ambiental mundial na atualidade, falar de conservação implica, necessariamente, em abarcar todo o conteúdo que envolve essa temática, a exemplo das questões de cunho socioeconômico, histórico e cultural. Sendo assim, o presente artigo tem como objetivo discutir algumas estratégias que vêm sendo postas como recursos úteis aos novos modelos de conservação necessários ante os desafios do século XXI, expondo a importância da inclusão dessas ferramentas (com destaque à etnoconservação e à história ambiental) na identificação de áreas prioritárias para conservação, e no planejamento, implementação e manutenção de áreas protegidas sustentáveis, usando nessa discussão uma abordagem aberta e interdisciplinar acerca da questão.
Comunidades quilombolas e o Programa Nacional de Habitação Rural
Authors: Brandão André Augusto , Da Dalt Salete , Souza Sidimara Cristina de
Published: October 2018

Este artigo tem como objeto a inserção da população quilombola nas políticas definidas pelo Programa Nacional de Habitação Rural. Lançando mão de dados coletados em pesquisas recentes, discutimos as características das comunidades quilombolas que têm acessado a moradia por esta via. Os elementos que caracterizam a construção destas unidades habitacionais, são apresentados e avaliados a partir da relação com o desenho do Programa e com os gargalos operacionais que se impõem ao processo de implementação.
Saberes e Práticas Tradicionais em Movimento: A comunidade do Maracanã na rota de um projeto global
Authors: Shiraishi Neto Joaquim , Lima Rosirene Martins , Alcobaça Luzinele Everton de
Published: October 2018

A comunidade do Maracanã, localizada na zona rural de São Luís, MA, desde a última década, vem sofrendo um processo de asfixia, decorrente da expansão urbana da cidade, com a construção, no seu entorno, de conjuntos do Programa Minha Casa Minha Vida. Os processos de devastação e o adensamento populacional da área do Maracanã produziu uma nova ordem de problemas, que reconfigurou o espaço, trazendo consigo novos desafios aos “antigos moradores”. Assim, este artigo objetiva refletir sobre esses processos em curso, que implicam na reorganização das maneiras de viver da comunidade, coadunadas em saberes e práticas socialmente construídas. A metodologia utilizada se fundamentou em técnicas de observação direta e conversas com os moradores da comunidade, realizadas em distintos contextos. Os esforços em analisar as situações empiricamente observadas revelam o caráter preliminar da pesquisa.
Um “skyline” em mutação: o velho centro e as transformações urbanas em Belém
Authors: Trindade Júnior Saint-Clair Cordeiro da
Published: October 2018

Os processos de requalificação de áreas centrais nas cidades brasileiras têm colocado questionamentos sobre a natureza da apropriação do espaço que se faz presente nessas cidades. Nesse sentido, busca-se indagar se as mudanças observadas na realidade urbana do Brasil seriam semelhantes às repercussões socioespaciais verificadas em outros países que vivenciaram processos de gentrificação. Ao discutir o caso de Belém, a análise situa a importância das intervenções urbanísticas no centro histórico da cidade e estabelece relação com o perfil das transformações que acontecem nos bairros de seu entorno imediato. Conclui-se mostrando que o centro histórico, pontualmente renovado, juntamente com alguns espaços que lhe são adjacentes, vivenciam processos de apropriação que sugerem pensar em uma forma embrionária de gentrificação urbana, mas com contornos particulares, e que merece ser adjetivada.
Introdução a Teoria de Bandas em sólidos
Authors: Silva C. M. da
Published: October 2018

The band theory of metals is presented The bands are a consequence of the lattice free electrons energy levels.
Uma revisão da Teoria Estatística da Difusão Turbulenta
Authors: Degrazia Gervásio Annes , Moraes Osvaldo L. L.
Published: October 2018

The Taylor statistical theory is presented wiht special emphasis in the relationship between turbulent dispersion and energy spectra. New turbulent diffusion coeficients based on parameters which describe the physics of the atmospheric boundary layer. are defined.
Aceleradores e detetores de partículas, uma introdução à física experimental de partículas elementares
Authors: Graça Cláudio
Published: October 2018

The history of particle acelerators is one of the classical examples of the spetacular advances in modern science. From the very modest machines of Lawrence and Cockroft-Walton vast laboratories have grown and many of the most important scientific discoveries in the last decades have been made using huge particle accelerators. Two distinct lines of progress have been followed, one started by J. Cookroft and E.T.S. Walton resulted in Iinear accelerators. The other school led by later E.O. Lawrence who developed the ciclotron resulted in magnetic confinement machines, whose modern version is the sincrotron with particle storage ring and collider. The devices described, (accelerators and detectors) in this work are dated but the principles they illustrate are still being applied in the most modern machines despite the use of modern technologies like superconductor magnets.
Enzymatic approach for bioremediation of effluent from pulp and paper industry by thermo alkali stable laccase from Bacillus tequilensis SN4
Authors: Sondhi Sonica , Kumar Deepak , Angural Steffy , Sharma Prince , Gupta Naveen
Published: October 2018

Treatments of industrial effluent/s by enzymes offer significant advantage over the use of microorganisms. However they have not been explored for the bioremediation of effluent from pulp and paper industry. This may be because of the less availability of lignolytic enzymes which can be active/stable under extreme environmental conditions that are present in effluent treatment plant of pulp and paper mills. In present study use of thermoalkali stable laccase from Bacillus tequilensis SN4 has been explored for the bioremediation of paper mill effluent. Under standardized conditions significant reduction in various parameters , color 83%, BOD 82%, COD 77%, phenol content 62%, lignin content 74%, TDS 28% and TSS 34%, was achieved. Major advantage was that treatment time was only 4h, much less than the bioremediation reported with the use of  microorganisms, which is usually four to five days. Results indicate that SN4 laccase is very suitable to develop a process for the effective bioremediation of effluent from pulp and paper industry.
Wearable Large Volume Injectors Hold Promise for Success in Commercialization of Biologics
Authors: Hooven Michael D. , Joughin Jeannie
Published: October 2018

With so many biologics in development and no patient-centric way to deliver them, it was inevitable that innovative delivery solutions would emerge that enable a new pharmaceutical product to meet two top criteria for successful commercialization: satisfy patient demands for easy drug administration without disruption to their everyday lives, and address health system demands for lower costs and more value. The solution lies in combining biologic drugs with the more advanced large volume wearable injectors to enable patients to self-inject even the most viscous formulations and volumes of up to 50 mL with ease and comfort in their homes or workplaces.
Research on Safety Hazard Control of Genetically Modified Organisms Based on Compensation Laws
Authors: Fei Chensong
Published: October 2018

In this paper, we firstly analyzed the categories and characteristics of safety hazards of genetically modified organisms. Then, we summarized and compared the laws on safety hazard compensation for genetically modified organisms in the United States, the European Union and China. Finally, suggestions were put forward to solve the existing problems in compensation laws in China so as to ensure the healthy and orderly development of China's genetically modified biological industry.
Design Thinking at Daedalus
Authors: Beale Matt , Cunningham Tim
Published: October 2018

Developing solutions for biopharma/medtech/digital medicine products and services requires a cross-disciplinary team to engage a broad section of the healthcare ecosystem. Unlike technology products, this ecosystem is more complex and involves patients, physicians, providers, payers, and partners. Each of these parties must be engaged to understand overall market need, requirements, and constraints. This article focuses on design thinking as part of the overall strategic and marketing resources that can be used to observe, question, and understand the needs of the entire ecosystem. The interdisciplinary commercialization team can thereby reach a common understanding of the outcome of each component of the job to be done from the perspectives of each party, and thereby achieve overall product/market fit for the product design and overall business model components. This chapter outlines the perspective and approach of Daedalus, a full-service, interdisciplinary product development firm with decades of experience working with medtech companies. The article is complementary and supplementary to the materials on design thinking in Part One of this monograph/special edition. It also covers several examples as mini cases that are pertinent to healthcare from projects undertaken by Daedalus, Inc. from their industry portfolio of achievements.
The effect of electrical head-to-chest stunning on the EEG in sheep
Authors: Mason A , Tolo E , Hektoen L , Haga HA
Published: October 2018

Head-to-body stunning is regarded as ‘best practice’ stunning for sheep. The benefits are loss of consciousness followed by cardiac arrest, death, prevention of animal movements post stun/kill and improved meat quality. Commercial equipment places electrodes on the head and back, which is known to cause pelt burning, thus reducing the value of the skins. The aim was to demonstrate that passing current at 1.5 A and 50 Hz from the top of the head to the chest in lambs for 3.1 s would result in epilepsy. Electroencephalographic (EEG) and electrocardiographic (ECG) activity was recorded in sheep using non-invasive electrodes. Measurements in this trial were successfully performed on three lambs (live weight 25 to 39 kg) which were anaesthetised and given neuromuscular blockers to inhibit muscle activity. EEG information showed that the head-to-chest stunning produced an epileptic-like episode, which was followed by an isoelectric output. ECG recordings showed that ventricular fibrillation (VF) was induced and coincided with the epileptic brain activity observed. No animals regained brain activity or sinus heart rhythm after applying the stated stunning conditions. As a conclusion, it is postulated that modified stunning equipment passing an electrical current from the top of the head to the sternum in lambs (1.5 A, 50 Hz; 3.1 s) may induce an epileptic seizure and VF.
Perceptions of dog breeding practices, breeding dog welfare and companion dog acquisition in a self-selected sample of Australian adults
Authors: Woodhead JK , Feng LC , Howell TJ , Ruby MB , Bennett PC
Published: October 2018

Welfare considerations surrounding dog (Canis familiaris) breeding practices are contentious in some sectors of the community. However, public perceptions surrounding dog breeding practices are poorly understood. The aims of this study were to describe perceptions of dog breeding and associated welfare concerns held by members of the general public and identify whether factors exist that potentially predict these perceptions. Australian residents (n = 986) completed an online questionnaire investigating their perceptions of, and attitudes towards, companion dog breeding and other acquisition methods. Participants predominantly indicated that breeding dog welfare was important, that dog breeding should be regulated, and that tougher laws are necessary to improve breeding dog welfare. Furthermore, three groups of respondents were identified: those who supported breeder-sourced companion dogs but felt that current regulations were inadequate to ensure satisfactory welfare, those who disapproved of dog breeding and felt adoption was the only appropriate acquisition method, and those who felt breeding was acceptable and that current industry practices provide adequate welfare. Several participant factors predicted cluster membership, including age, characteristics considered important when acquiring a companion dog, the source of their most recent dog, and their dog breeding knowledge and/or experience. This study provides a direct preliminary examination of public perceptions of dog breeding, breeding practices, and associated welfare concerns, and the factors associated with these perceptions. This information can be used to guide those who provide companion dogs to the public and inform evidence-based policy development concerning companion dog breeding and acquisition.
Restricting the ability of sows to move: a source of concern for some Brazilians
Authors: Yunes MC , von Keyserling MAG , Hötzel MJ
Published: October 2018

Gestation stall housing for pregnant sows (Sus scrofa) has been, or is being, phased out in many parts of the world in response to public criticism. However, in Brazil, one of the largest global producers and exporters of pork, gestation stall housing is still common. The objective of this study was to explore the views of Brazilians, including participants associated (ALP) or not with livestock production (NotALP), on gestation stall housing. Participants were provided the option of accessing a short text describing the housing system and a video of pregnant sows housed in either individual or group housing. Participants (ALP; n = 176, NotALP; n = 173) were asked to state their position on housing pregnant sows in individual stalls and to provide the reason(s) justifying their position. More NotALP (87%) participants than ALP (69%) participants rejected individual stalls. More participants (85%) that accessed the optional information rejected the stalls than those (71%) that did not. Qualitative analyses revealed that animal welfare, most often in reference to animal sentience, freedom of movement and ethics, was the main justification given for rejecting gestation stalls. Those in favour of individual stalls justified their position with statements such as improved production, handling and animal health, and reduced aggression. This qualitative, exploratory study, based on a convenience sample of participants, does not represent the views of Brazilian society; however, it identified some shared values between participants associated with livestock production and those that are not. Our findings highlight that opposition to gestation stalls for sows reflects an ethical position regarding the treatment of livestock and should not be interpreted as support for group housing in confined systems.
L’évolution de la radio de langue française en Acadie, 1939–1959
Authors: Canuel Alain
Published: October 2018

La présente analyse porte sur le développement de la radio acadienne (CBAF) depuis ses débuts jusqu’à la mise en service des postes relais permettant de rejoindre la majorité de la population acadienne des Maritimes. L’étude retrace les principaux jalons de son histoire, à savoir : l’influence de la radio québécoise à ses débuts, le regroupement de diverses personnalités acadiennes, le rôle du clergé catholique, la mobilisation de la population et les campagnes de sensibilisation du journal L’Évangéline. L’analyse fait également état des démarches entreprises auprès des autorités de Radio-Canada pour la création d’une station acadienne, des revendications sous forme de rapports et de mémoires auprès d’instances politiques et administratives et des luttes menées par les élites et organismes acadiens. Nous concluons sur la portée de CBAF au regard de la radio communautaire.
Why our brains love arts and crafts
Authors: Huotilainen Minna , Rankanen Mimmu , Groth Camilla , Seitamaa-Hakkarainen Pirita , Mäkelä Maarit
Published: October 2018

Art and craft practitioners have personal experience of the benefits of making: the handling of material can help to regulate our mental states through providing a means to reach flow states. The mirror neuron system helps in skill learning, and the plasticity of the brain ensures that skills may be learned at all stages of life. Arts and crafts play a role in controlling stress and enhancing relaxation. They also enable us to fail safely and handle our emotions. Furthermore, they facilitate social activity for many individuals who are at risk of social isolation. This article aims to integrate knowledge from both the field of neuroscience and the arts by focusing on the implications that flow experience and the mirror neuron system integral to making processes have on our psychophysical well-being.
Direct Fabrication of Stretchable Electronics on a Polymer Substrate with Process‐Integrated Programmable Rigidity
Authors: Cao Yu , Zhang Guogao , Zhang Yingchao , Yue Mengkun , Chen Ying , Cai Shisheng , Xie Tao , Feng Xue
Published: October 2018

Despite the increasingly important role of stretchable electronics for use as the human–machine interface, their manufacturing in a commercially realistic manner remains an unresolved challenge. The bottleneck lies in the efficiency and scalability of transfer printing that is typically employed in the fabrication process to enable device stretchability via strain isolation. Here, the use of a polymer substrate with programmable rigidity for direct manufacturing of stretchable electronics is reported, forgoing the need for transfer printing while significantly enhancing strain isolation. The process starts with a stretchable elastomeric substrate synthesized via the thiol‐acrylate click chemistry. Designable rigid islands can be introduced via spatially confined oxidation of the elastomer. Strain‐sensitive microdevices can then be directly fabricated onto the rigid islands without transfer printing. Following this manufacturing scheme, a fast‐responding stretchable temperature sensor is demonstrated, with unusual accuracy and real‐time temperature monitoring capability suitable for use in a highly dynamic environment. Importantly, the critical fabrication step that introduces the programmable substrate rigidity is fully integrated into a well‐established lithographic process. Therefore, the methodology not only reduces greatly the complexity in fabricating prototype devices but also points to a highly effective way for potential manufacturing in a commercial setting.
High‐Frequency Stimulation of Normal and Blind Mouse Retinas Using TiO2 Nanotubes
Authors: Ronzani Carole , Cottineau Thomas , Gonzalez‐Valls Irene , Keller Valérie , Picaud Serge , Keller Nicolas , Roux Michel Joseph
Published: October 2018

With three models in commercial use, artificial retinas are the most concrete hope to restore sight to blind patients, notably those affected with retinitis pigmentosa. However, present architectures are costly to produce, while the restored visual acuity remains below the legal threshold for blindness. Furthermore, the complexity of current systems with tethered application‐specific integrated circuits (asics) requires complex surgeries, with risks of complications and failures. In the search for new nanomaterials, it is demonstrated that, when placed in contact with photoreceptors (control mouse retinas) or directly with bipolar cells (rhodopsinP23H mouse retinas, a model of retinitis pigmentosa), films of vertically aligned anatase titanium dioxide (TiO2) nanotubes can drive the activity of the retinal network for stimulation frequencies up to the video rate (25 Hz), in response to short (5–20 ms), small (50–100 µm) light spots. Acting as continuous arrays of electrodes, these films should allow a fine tuning of prosthetic stimulations, through modulation of the spot size, duration, and precise localization over the implant surface.
Biotemplated Synthesis of Transition Metal Nitride Architectures for Flexible Printed Circuits and Wearable Energy Storages
Authors: Yi Yuyang , Yu Lianghao , Tian Zhengnan , Song Yingze , Shao Yuanlong , Gao Lijun , Sun Jingyu , Liu Zhongfan
Published: October 2018

Transition metal nitrides have stimulated a growing research and technological interests due to their fascinating properties, holding great promise for wearable energy storages, portable electronics, and many other applications. However, tailorable and efficient production of metallic nitrides in a cost‐effective manner has remained a daunting challenge by far. Here a biotemplate‐assisted strategy is reported with generality and scalability that employs the natural‐abundant diatomites as growth templates and is applicable to producing various transition metal nitrides, including but not limited to, VN, Mo2N, and WN. The conformal growth of nitride materials would inherit the morphological features of the diatomite template, thereby, endowing the obtained architectures with versatile pore structures and abundant edge defects. Thus‐derived metal nitrides with favorable electrical conductivity and solution‐processible feature have significant implications for flexible printed circuits and electronics. The excellent pseudocapacitive properties of metal nitrides further lead to the construction of flexible, symmetric quasi‐solid‐state supercapacitor devices with stable performance under mechanical deformation (achieving an energy density of 15.5 Wh kg−1 at a power density of 1147.3 W kg−1). The demonstration of such biotemplated synthesis would offer an efficient solution to expand the family of emerging nitride materials with attractive properties for next‐generation wearable applications.
Crystallization Control of Organic Semiconductors during Meniscus‐Guided Coating by Blending with Polymer Binder
Authors: Zhang Ke , Marszalek Tomasz , Wucher Philipp , Wang Zuyuan , Veith Lothar , Lu Hao , Räder Hans‐Joachim , Beaujuge Pierre M. , Blom Paul W. M. , Pisula Wojciech
Published: October 2018

Small molecule organic semiconductors (OSCs) suffer from their uncontrolled nucleation and growth during solution processing limiting their functionality in electronic devices. In this work, a new method is presented based on dip‐coating a blend consisting of OSC and insulating polymer to control the crystallization of the active film for organic field‐effect transistors. A small fraction of amorphous poly(methyl methacrylate) (PMMA) efficiently improves the crystallization of dip‐coated small molecule OSCs, α,ω‐dihexylquaterthiophene (DH4T) and diketopyrrolopyrrole‐sexithiophene (DPP6T). The maximum charge carrier mobilities of dip‐coated OSC:PMMA films are significantly higher than drop‐cast blend ones and comparable with OSC single crystals. The high charge carrier mobility originates from a continuous alignment of the crystalline films and stratified OSC and PMMA layers. The improved crystallization is attributed to two mechanisms: first, the polymer binder leads to a viscosity gradient at the meniscus during dip‐coating, facilitating the draw of solute and thus mass transport. Second, the polymer binder solidifies at the bottom layer, reducing the nucleation barrier height of small molecule OSC. The findings demonstrate that a small fraction of a polymer binder during dip‐coating efficiently improves the crystallization as well as the electronic properties of small molecule OSC films.
Transparent Graphene/PEDOT:PSS Microelectrodes for Electro‐ and Optophysiology
Authors: Kshirsagar Pranoti , Dickreuter Simon , Mierzejewski Michael , Burkhardt Claus J. , Chassé Thomas , Fleischer Monika , Jones Peter D.
Published: October 2018

Conventional opaque electrodes in microelectrode array (MEA) technology obstruct the view of cells in their immediate vicinity (e.g., ≈50 µm) from which the strongest extracellular action potentials are recorded. This limitation has been overcome by transparent graphene electrodes which allow for optical access essential for novel applications such as optogenetics and calcium imaging. Downscaling, necessary for high resolution single‐unit electrophysiological recordings, has been a significant challenge due to inferior electrochemical impedance and correspondingly lower signal‐to‐noise ratio. Here, the combination of graphene with the conductive polymer poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as a transparent microelectrode material for in vitro MEAs is presented and their application with optical imaging and electrophysiology is demonstrated. Optimal graphene/PEDOT:PSS microelectrodes display transparencies of 84% over the visible spectrum and impedance magnitude of (166 ± 13) kΩ at 1 kHz. The balance of transparency and 1 kHz impedance can be tuned from ≈90% and 700 kΩ to 50% and 42 kΩ.
Nickel–Cobalt Double Hydroxide as a Multifunctional Mediator for Ultrahigh‐Rate and Ultralong‐Life Li–S Batteries
Authors: Zhang Long , Chen Zhongxin , Dongfang Nanchen , Li Mengxiong , Diao Caozheng , Wu Qingsong , Chi Xiao , Jiang Peilu , Zhao Zedong , Dong Lei , Che Renchao , Loh Kian Ping , Lu Hongbin
Published: October 2018

The performance of lithium–sulfur (Li–S) batteries is largely hindered by the shuttle effect caused by the dissolution of lithium polysulfides (LiPSs) and the sluggish reaction kinetics of LiPSs. Here, it is demonstrated that the nickel–cobalt double hydroxide (NiCo‐DH) shells that encapsulate sulfur nanoparticles can play multiple roles in suppressing the shuttle effect and accelerating the redox kinetics of LiPSs by combining with graphene and carbon nanotubes to construct the conductive networks. The NiCo‐DH shell that intimately contacts with sulfur physically confines the loss of sulfur and promotes the charge transfer and ion diffusion. More importantly, it can react with LiPSs to produce the surface‐bound intermediates, which are able to anchor the soluble LiPSs and accelerate the redox kinetics. Such composite electrodes can load high contents of sulfur (>85 wt%) and the resulting Li–S battery exhibits a superior capacity (1348.1 mAh g−1 at 0.1 C), ultrahigh rate performance (697.7 mAh g−1 at 5 C), and ultralong cycle life (1500 cycles) with a decay rate of 0.015% per cycle.
Phenological sequences: how early‐season events define those that follow
Authors: Ettinger A. K. , Gee S. , Wolkovich E. M.
Published: October 2018

Premise of the Study

Plant phenology is a critical trait, as the timings of phenophases such as budburst, leafout, flowering, and fruiting, are important to plant fitness. Despite much study about when individual phenophases occur and how they may shift with climate change, little is known about how multiple phenophases relate to one another across an entire growing season. We test the extent to which early phenological stages constrain later ones, throughout a growing season, across 25 angiosperm tree species.

Methods

We observed phenology (budburst, leafout, flowering, fruiting, and senescence) of 118 individual trees across 25 species, from April through December 2015.

Key Results

We found that early phenological events weakly constrain most later events, with the strongest constraints seen between consecutive stages. In contrast, interphase duration was a much stronger predictor of phenology, especially for reproductive events, suggesting that the development time of flowers and fruits may constrain the phenology of these events.

Conclusions

Much of the variation in later phenological events can be explained by the timing of earlier events and by interphase durations. This highlights that a shift in one phenophase may often have cascading effects on later phases. Accurate forecasts of climate change impacts should therefore include multiple phenophases within and across years.
Occupational fatal injuries associated with mobile hand‐fed wood chippers
Authors: Zhu Julia , Gelberg Kitty
Published: October 2018

Background

Workers are killed every year in wood chipper‐related incidents despite the repeated hazard warnings. In‐depth, comprehensive, and up‐to‐date studies are needed to identify causal, risk, and contributing factors and assess the current control measures so that an effective and proactive prevention approach can be developed.

Methods

Cases were identified from four online databases and manually reviewed to characterize and categorize the fatal events.

Results

The study identified 113 wood chipper‐related worker deaths (1982‐2016). The victims were killed in struck‐by (57), caught‐in (41), motor vehicle (7), electrical (4), fall (2), and heat stroke (2) incidents while performing chipper‐related tasks.

Conclusions

Chipper‐related worker deaths are preventable. Young and inexperienced workers may be at higher risk for caught‐in deaths. The current feed wheel control devices are not effective for workers to self‐rescue. Fully automatic feed wheel stop devices are needed to prevent caught‐in incidents.
Strain‐Promoted Reactivity of Alkyne‐Containing Cycloparaphenylenes
Authors: Schaub Tobias A. , Margraf Johannes T. , Zakharov Lev , Reuter Karsten , Jasti Ramesh
Published: October 2018

A new class of macrocyclic angle‐strained alkynes whose size and reactivity can be precisely tuned by modular organic synthesis is disclosed. Detailed analysis of the size‐dependent structural and electronic properties provides evidence for considerable distortion of the alkyne units incorporated into the cycloparaphenylene (CPP)‐derived macrocycles. The remarkable increase of the alkyne reactivity with decreasing macrocycle size in [2+2]cycloaddition–retrocyclization was investigated by joint experimental and theoretical studies and the thermodynamic and kinetic parameters that govern this reaction were unraveled. Additionally, even the largest, least strained macrocycle in this series was found to undergo strain‐promoted azide–alkyne cycloaddition (SPAAC) efficiently under mild conditions, thereby paving the way to the application of alkyne‐containing CPPs as fluorescent “clickable” macrocyclic architectures.
2D MoN‐VN Heterostructure To Regulate Polysulfides for Highly Efficient Lithium‐Sulfur Batteries
Authors: Ye Chao , Jiao Yan , Jin Huanyu , Slattery Ashley D. , Davey Kenneth , Wang Haihui , Qiao Shi‐Zhang
Published: October 2018

Lithium‐sulfur batteries hold promise for next‐generation batteries. A problem, however, is rapid capacity fading. Moreover, atomic‐level understanding of the chemical interaction between sulfur host and polysulfides is poorly elucidated from a theoretical perspective. Here, a two‐dimensional (2D) heterostructured MoN‐VN is fabricated and investigated as a new model sulfur host. Theoretical calculations indicate that electronic structure of MoN can be tailored by incorporation of V. This leads to enhanced polysulfides adsorption. Additionally, in situ synchrotron X‐ray diffraction and electrochemical measurements reveal effective regulation and utilization of the polysulfides in the MoN‐VN. The MoN‐VN‐based lithium‐sulfur batteries have a capacity of 708 mA h g−1 at 2 C and a capacity decay as low as 0.068 % per cycle during 500 cycles with sulfur loading of 3.0 mg cm−2.
Schnelle Strukturaufklärung mikrokristalliner molekularer Verbindungen durch Elektronenbeugung
Authors: Gruene Tim , Wennmacher Julian T. C. , Zaubitzer Christan , Holstein Julian J. , Heidler Jonas , Fecteau‐Lefebvre Ariane , De Carlo Sacha , Müller Elisabeth , Goldie Kenneth N. , Regeni Irene , Li Teng , Santiso‐Quinones Gustavo , Steinfeld Gunther , Handschin Stephan , van Genderen Eric , van Bokhoven Jeroen A. , Clever Guido H. , Pantelic Radosav
Published: October 2018

Derzeit publizieren Chemiker aller Fachrichtungen ca. 50 000 Kristallstrukturen pro Jahr, von denen es sich bei der überwältigenden Mehrheit um Röntgenstrukturen handelt. Wir setzen Elektronen‐ statt Röntgenbeugung ein, um die Struktur zweier molekularer Verbindungen zu bestimmen. Zu diesem Zweck wurde ein EIGER‐Hybridpixeldetektor an ein Transmissionselektronenmikroskop angebaut und so ein Elektronendiffraktometer konstruiert. Die Struktur eines neuen Methylenblauderivates wurde aus einem Kristall kleiner als 1×2 μm2 mit einer Auflösung von 0.9 Å bestimmt. Mehrere tausend Wirkstoffe sind nur als submikrokristallines Pulver verfügbar. Um das Potenzial für die pharmazeutische Industrie zu verdeutlichen, haben wir die Struktur eines Wirkstoffs direkt aus einer Tablette bestimmt. Wir demonstrieren, dass Elektronenkristallographie die Röntgenkristallographie ergänzt und die Methode der Wahl ist für alle ungelösten Strukturen von submikrometergroßen Kristallen. Die Größe der Kristalle ist uns hier wichtig als Kriterium für die Elektronenbeugung.
A Long‐Lived Halogen‐Bonding Anion Triple Helicate Accommodates Rapid Guest Exchange
Authors: Massena Casey J. , Decato Daniel A. , Berryman Orion B.
Published: October 2018

Anion‐templated helical structures are emerging as a dynamic and tractable class of supramolecules that exhibit anion‐switchable self‐assembly. We present the first kinetic studies of an anion helicate by utilizing halogen‐bonding m‐arylene‐ethynylene oligomers. These ligands formed high‐fidelity triple helicates in solution with surprisingly long lifetimes on the order of seconds even at elevated temperatures. We propose an associative ligand‐exchange mechanism that proceeded slowly on the same timescale. In contrast, intrachannel anion exchange occurred rapidly within milliseconds or faster as determined by stopped‐flow visible spectroscopy. Additionally, the helicate accommodated bromide in solution and the solid state, while the thermodynamic stability of the triplex favored larger halide ions (bromide≈iodide≫chloride). Taken together, we elucidate a new class of kinetically stable helicates. These anion‐switchable triplexes maintain their architectures while accommodating fast intrachannel guest exchange.
Free Fatty‐Acid Generation and Lipid Oxidation during Dry‐Grind Corn Ethanol Fermentation
Authors: Brothers Brett , Wang Hui , Wang Tong
Published: October 2018

The formation of free fatty acid (FFA) is an undesirable change during dry‐grind corn ethanol fermentation because it negatively affects biodiesel transformation. The primary objective of this work was to determine where in the process FFA is generated using laboratory‐scale simulation experiments. TLC and GC were used to quantify FFA in the extracted total lipids. Values obtained from FFA determination by titration were also compared with those obtained from TLC‐GC. Results indicate that FFA generation is due to an incremental increase at each step in the process, particularly at the early slurrying and liquefaction stage, and also likely during the continuous backset. Furthermore, laboratory‐based fermentations indicate that the oxidation of linoleic acid in the FFA fraction and possibly in the oil increased the FFA level determined using the titration method. Industrial oil samples collected were shown to be highly oxidized and this led to an overestimation of FFA by 15–24% using the titration method compared to TLC‐GC due to the formation of a secondary oxidation product, acids. Such a discrepancy in FFA quantification and the level of lipid oxidation have not been seen in the literature.
Aqueously soluble semi‐aromatic copolyamides with dual‐functional groups as sizing agent
Authors: Qi X. , Wang W. , Zhang J. , Yan C. , Zhu Y. , Zhang F.
Published: October 2018

A series of novel aqueously soluble semi‐aromatic (co)polyamides, poly[(ethylenedioxy)bis(ethylene) terephthalamide]‐ran‐poly[(ethylenedioxy)bis(ethylene) (2,5‐dihydroxy‐3,6‐diallyl)terephthalamide] (CRPAOT‐x), were prepared via the solid‐state Claisen rearrangement reaction of poly[(ethylenedioxy)bis(ethylene) terephthalamide]‐ran‐poly[(ethylenedioxy)bis(ethylene) 2,5‐bis(allyloxy)terephthalamide] (APAOT‐x), where x (= 0, 13, 25, 50, 75, and 100) represents the molar fraction of allyloxy containing unit. APAOT‐x was obtained through the interfacial copolymerization of terephthaloyl chloride, 2,5‐bis(allyloxy)terephthaloyl chloride, and 2,2′‐(ethylenedioxy)bis(ethylamine). The reaction conditions including reactant concentration, temperature, and solvent were optimized. The chemical structures of the target (co)polyamides and their precursors were characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopies. The incorporation of hydrophilic (ethylenedioxy)bis(ethylene) units greatly improved the polymer solubility. CRPAOT‐x dissolved not only in polar organic solvents such as dimethylformamide, dimethyl sulfoxide, and N‐methyl pyrrolidone but also in ammonia water. Due to the presence of hydroxyl groups and oxygen‐rich aliphatic units, CRPAOT‐x showed excellent affinity toward epoxy resins. The microbond test indicated that the aramid fibers sized by these dual‐functional polymers exhibited remarkably enhanced interfacial shear strength in epoxy matrices. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47132.
The effect of brominated epoxy on epoxy/phenolic reactive blends
Authors: Sheinbaum L. , Sheinbaum M. , Weizman O. , Dodiuk H. , Kenig S.
Published: October 2018

Innovative reactive blends containing epoxy and brominated epoxy (BE) incorporated with resole‐type phenolic were studied with the aim to elucidate the curing kinetics and the final thermomechanical characteristics of this unique system. Curing kinetics was investigated by means of the activation energy determined using differential scanning calorimetry (DSC ) at various heating rates analyzed by the Arrhenius equation. Both DSC and Fourier transform infrared revealed that bromine elimination at elevated temperatures (above 220 °C) had lowered the activation energy in the case of BE containing phenolic blends. The thermomechanical properties showed that the addition of conventional epoxy to resole decreased its thermal properties and modulus compared to neat resole. Distinctively, BE/resole blends exhibited increased glass‐transition temperature, compared to diglycidyl ether of bisphenol A/resole blends in combination with higher elongation and toughness compared to neat resole. It was concluded that BE/epoxy resin/phenolic reactive systems offer highTg, mechanical properties and toughness and hence are applicable for structural adhesives and for matrices of polymer‐fiber composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47172.
Anisotropic polyimide aerogels fabricated by directional freezing
Authors: Wu Peng , Zhang Bin , Yu Zhi , Zou Huawei , Liu Pengbo
Published: October 2018

In this study, we adapted a simple, low‐cost, and environmentally friendly method to fabricate anisotropic polyimide (PI) aerogels. During directional freezing of an aqueous poly(amic acid) ammonium salt solution from the profile to the center axis of the cylindrical mold, the ice crystals preferred to grow along the radial direction of the cylindrical mold. After the ice crystals were sublimated by freeze drying, an anisotropic pore structure was formed in the aerogels. The prepared PI aerogels had lower densities (0.04–0.22 g/cm3) and higher porosities (84–97%) and exhibited anisotropy in both their pore structures and properties. Their compressive modulus and strength in the horizontal direction were both higher than those in the vertical direction, and they also had good compression recovery in the vertical direction. Moreover, their heat‐transfer performance also exhibited anisotropy. The heat transfer in the horizontal direction of the aerogels was much faster than that in the vertical direction. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47179.