420 research outputs found
Influence of a plasma jet on the hydrodynamics of a helium jet
In this paper, we present a study of the influence of non-equilibrium microplasma jets (“plasma bullets”) on the hydrodynamics of a helium jet operating in open air. The helium jet is produced by a flow of helium through a hollow, cylindrical microdischarge configuration. A plasma jet, triggered by the microdischarge, can propogate in the laminar zone of the helium jet which extends some distance from the exit plane of the microdischarge. We used Schlieren photography to visualize the point of transition from laminar to turbulent regime of the helium jet and the change in the transition point due to the plasma jet for different operating conditions
To Open a Clearing: Cultivating Spaces of Endurance in the Upper Amazon
To effectively challenge the policies of extraction implemented by late liberal regimes, the Waorani communities from Upper Amazon have devised spatial strategies to defend their traditional territory. By re-examining the concept of the contact zone and unfolding settler and Indigenous literature, spatialities, and worldviews, this thesis suggests the concept of forest Clearings as a means to explore spatial forms of endurance.
Clearings emerge within the Amazon in sites where encounters between divergent worldviews embody otherwise modes of existence. Through a series of fieldwork reflections, these Clearings are perceived as spaces where ontological negotiations are more likely to occur, strategies of enduring exhaustion are nurtured, and forms of dominance rattle.
Central to this work is the ambition of a Waorani member to establish a Museo Vivo, or a living museum, in the Amazon forest. Unpacking the intertwined histories of museums as hegemonic infrastructures that facilitate extractive colonial projects in the region, this work examines the appropriation of the museum as a trap to ensnare and redirect our attention toward a more pressing matter: the defense of Waorani ancestral territory. In essence, opening a Clearing to foster alternative life forms capable of sustaining a stubborn refusal to collapse.
This thesis invites us to acknowledge our agency as researchers, architects, and artists when navigating projects with local communities, like the Waorani. The work proposes that assuming responsibility as active agents within the social ecology of Clearings—embracing the condition of being seen seen by one another—gives rise to new collaborative practices and ontological exchanges
Differential Peptide Multi-Macrocyclizations at the Surface of a Helical Foldamer Template
Hybrid sequences comprising a peptide with several Cys residues and an aromatic foldamer helix with several chloroacetamide functions at its surface were synthesized. Such products may in principle form numerous macromulticyclic thioether products by intramolecularly combining all Cys residues and all chloroacetamide functions. However, we show that the reactive sites on the structurally defined helix can be placed at such locations that the peptide selectively stitches itself to form a series of different macrocycles within mostly one preferred product. Reactions were monitored by HPLC and products with two, three or four macrocycles were identified using LC-MS and NMR. The series of selective macrocyclizations define a sort of reaction trail where reaction sites otherwise identical are involved successively because of their precise positioning in space. The trails can be predicted to a large extent based on structural considerations and the assumption that smaller macrocycles form faster
"Am I as extended as you say I am?" Consumers' emic perspectives on the extended self
We would like to thank Pauline Maclaren (Editor) and each of the three reviewers of our work for their constructive comments and support throughout the review process. We would also like to thank Paula Gould and Grace Mackie for providing feedback on an earlier draft of this paper.Peer reviewedPostprin
Controlling the nitric and nitrous oxide production of an atmospheric pressure plasma jet-/title-
International audienceAtmospheric pressure plasma jets are non-thermal plasmas and have the ability to create reactive species. These features make it a very attractive tool for biomedi-cal applications. In this work, we studied NO and N 2 O production, which are two species having biomedical properties. NO plays a role in the vascularization and in ulcer treatment, while N 2 O is used as anesthetic and analgesic gas. In this study, the plasma source is similar to the COST Reference Microplasma Jet (–APPJ). Helium is used as feed gas with small admixtures of molecular nitrogen and oxygen of below 1%. The absolute densities of NO and N 2 O were measured in the effluent of an atmospheric pressure RF plasma jet by means of ex-situ quantum-cascade laser absorption spectroscopy via a multi-pass cell in Herriot configuration. We will show that the species' production is dependent on several parameters such as power, flow and oxygen and nitrogen admixture. The NO and N 2 O densities are strongly dependent on the N 2-O 2 ratio. Changing this ratio allows for choosing between a NO-rich or a N 2 O-rich regime [1]. [1] Douat et al, PSST, 25 (2016) 02502
“Caring Is Sharing”: The Effect of Childhood Memories on Consumers’ Lending Behavior
This research demonstrates that recalling childhood memories increases the likelihood of lending one’s possessions to someone else by making people (particularly those who are less rebellious) feel more connected to their communities. Five studies demonstrate the predicted effect of childhood memories on consumers’ lending intentions and actual lending behavior. The studies also provide evidence that childhood memories increase less-rebellious consumers’ sense of self–community connectedness, which, in turn, facilitates lending, as sharing in (sharing with family and close others) is a far more common form of sharing than sharing outside those circles
Estabilização do caminhar de um robô bípede de 5 elos com compensação do movimento dorsal
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica.Este trabalho foca na análise e controle, no plano sagital, do caminhar de um robô bípede subatuado de 5 elos, a partir dos conceitos de energias mecânicas envolvida no movimento, trazendo duas contribuições. A principal contribuição foi propor o aproveitamento da posição relativa dorsal do robô para a compensação de momentos que conduz a um caminhar estável para qualquer horizonte de tempo de simulação. O sistema é controlado por meio da técnica de torque computado aliada a um controlador proporcional derivativo. A segunda contribuição foi a modificação do controlador PD para evitar que ocorra hiperextensão do joelho do robô, na sua perna de apoio com o solo. Para a obtenção dos resultados numéricos foi desenvolvido um simulador do robô. A robustez da estratégia adotada é verificada via simulações. This work focuses on the analisys and control, in the sagittal plane, of the gait of an underactuated 5-link bipedal robot, based on the concepts of the mechanical energies involved in the movement, bringing two contributions. The major contribution was the proposal of the usage of the robots relative dorsal position for the moments compensation that conduces to a stable walk for any simulation's time horizon. The system is controlled by means of the control torque technique together with a proportional derivative controller. The second contribution was the modification of the PD controller in order to avoid hyperextension at the robot's knee supporting leg. For numerical results a simulator was developed. Robustness of the adopted strategy is verified through simulations
Hybrid Cell-Penetrating Foldamer with Superior Intracellular Delivery Properties and Serum Stability
International audienceSequence specific molecules with high folding ability (i.e. foldamers) can be used to precisely control the distribution and projection of side chains in space and have recently been introduced as tailored systems for delivering nucleic acids into cells. Designed oligourea sequences with an amphipathic distribution of Arg-and His-type residues were shown to form tight complexes with plasmid DNA, and to effectively promote the release of DNA from the endosomes. Herein, we report the synthesis of new cell-penetrating foldamer sequences in which the foldamer segment is conjugated via a reducible disulfide bond to a ligand that binds cell-surface expressed nucleoproteins with the idea that this system could facilitate both assemblies with nucleic acids and cell entry. This new system was evaluated for delivery of DNA in several cell lines and was found to compare favorably with all comparators tested (DOTAP and b-PEI as well as a number of known cell penetrating peptides) in various cell lines and particularly in culture medium containing up to 50% of serum. These results suggest that this dual molecular platform which is long lasting and non-cytotoxic could be of practical use for in vivo applications
O mal-estar do coletivo: uma análise sobre as liberdades individuais dentro de uma ecovila
Este trabalho visa analisar como as liberdades individuais são expressas em uma proposta de convivência voltada para o coletivo, como são as ecovilas. O presente estudo contribui para uma reflexão sobre a vida em comunidade, assim como para criar um debate sobre trocas e concessões possíveis entre indivíduo e sociedade. A partir de uma pesquisa de campo, de abordagem qualitativa (com observação participante e entrevistas), foi possível perceber que os conflitos fazem parte do cotidiano local, mas que a convivência se torna viável através de construções de estratégias e propósitos – que podem ser importantes para a elaboração de alternativas à sociedade atual. Percebemos que os desafios para se construir uma vida com senso de comunidade em uma ecovila são diários, e são observados por seus moradores de diferentes formas – ao mesmo tempo em que estes ainda estão buscando conjugar as liberdades individuais com as necessidades coletivas, em um processo contínuo
Ribosomal Incorporation of Aromatic Oligoamides as Peptide Sidechain Appendages
Derivatives of 4‐aminomethyl‐l ‐phenylalanine with aromatic oligoamide foldamers as sidechain appendages were successfully charged on tRNA by means of flexizymes. Their subsequent incorporation both at the C‐terminus of, and within, peptide sequences by the ribosome, was demonstrated. These results expand the registry of chemical structures tolerated by the ribosome to sidechains significantly larger and more structurally defined than previously demonstrated
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