Shape Air Research Articles

Shape memory composite hydrogel based on sodium alginate dual crosslinked network with carboxymethyl cellulose

Based on the need for whole biomass hydrogels in biomedical applications, a dual-crosslinked hydrogel based on natural product sodium alginate (SA) were prepared. Dual-crosslinked was formed by SA crosslinking with glutaraldehyde (GA) and calcium ion (Ca2+), and the introduction of carboxymethyl cellulose (CMC) into crosslinked network to obtain excellent water-induced shape memory property. The chemical and physical crosslinking net points, formed by GA and Ca2+, as the stationary phase to hold the original shape; While hydrogen bonding interactions between CMC and SA as the switcher to fix the temporary shape in air and driving the recovery in water. The shape fixing and recovery ratio can reach 90%. The dual crosslinking effect and introduction of CMC, also strengthen the mechanical properties of hydrogels and change the size of pores in hydrogels. Cell culture experiment showed that these hydrogels are good at biocompatibility and can control the cell differentiation by adjusting the size of pores in hydrogel networks. For its excellent performance, these hydrogels can be potentially applied as biological device materials in the field such as soft tissue engineering, controlled drug release and bioactuators.

The Shape of Air: American Sign Language as Narrative Prosthesis in 21st Century North American Media

The Shape of Air: American Sign Language as Narrative Prosthesis in 21st Century North American Media

Flexible and Actuating Nanoporous Poly(Ionic Liquid)-Paper-Based Hybrid Membranes.

Porous and flexible actuating materials are important for the development of smart systems. We report here a facile method to prepare scalable, flexible actuating porous membranes based on a poly(ionic liquid)-modified tissue paper. The targeted membrane property profile was based on synergy of the gradient porous structure of a poly(ionic liquid) network and flexibility of a tissue paper. The gradient porous structure was built through an ammonia-triggered electrostatic complexation of a poly(ionic liquid) with poly(acrylic acid), which were previously impregnated inside the tissue paper. As a result, these porous membranes undergo deformation by bending in response to organic solvents in the vapor or liquid phase and can recover their shape in air, which demonstrates their ability to serve as solvent sensors. Besides, they show enhanced mechanical properties due to the introduction of mechanically flexible tissue paper that allows the membranes to be designed as new responsive textiles and contractile actuators.

Investigation on fretting wear behavior of 690 alloy in water under various temperatures

The aim of this paper is to assess the effect of water temperature (room temperature – RT, 60°C and 90°C) on fretting wear behavior of 690 alloy tubes against 405 stainless steel plates, and compare it with fretting in dry condition. Due to the lubrication effect, the presence of a thin water film likely precluded the metal-metal contact, and resulted in less wear. During the fretting process, water also washed the wear particles away from the contact zone leading to a decrease of abrasive wear. Consequently, the wear scars showed “U” shape profile along the fretting direction in water, while “W” shape in air.

Triangular blocks and wind tunnels: Augustin Rey's logic of air resistance

How does air shape our cities? How does air become a factor in urban design? In a session before the 1906 International Congress for Sanitary Dwellings, Adolphe Augustin Rey famously compared cities to vast bodies ‘furrowed by canals of air’. Rey (1864–1934), a Beaux-Arts-trained architect who would count Le Corbusier among his devotees, was then highlightinging his best-known project: the winning entry for the Fondation Rothschild's workers' housing competition in Paris. Conceived between 1905 and 1909, Rey's entry was a redesign of a triangular block formed by the Rue de Prague, Rue Charles Baudelaire, and Rue Theophile Roussel. Rey's design featured innovative open-air courtyards and perforated façades that would not only filter and cleanse the air inside the building, but would also contribute to healthier air in the city.This paper examines Rey's winning design from a different context: the burgeoning aeronautical culture in turn-of-the-century France. The focus will be on his drawings, with their depiction of buildings as white solids and of the dominant winds as dark lines of moving air with variable pressures: in short, architecture placed inside a wind tunnel. I argue that Rey's designs for the Rothschild competition provided an aerodynamic solution to urban block design. Rey's name is not usually associated with aeronautics, and yet the fact that his drawings look like wind tunnel visualisations is no mere coincidence. Here, the operative logic is that of resistance. Much like the French physiologist Xavier Bichat understood life as a product of ‘resistance’ against pathogens, Rey's designs show architecture as a product of air resistance. In the end, this paper proposes how one of the most fundamental aspects of twentieth-century urbanism, the design of the city block, can be viewed in the light of advances in aeronautics at the turn of the century.

Synthesis of organic-inorganic polymer structures via the interaction of orthoboric acid with m-phenylene-bismaleimide

The structure and properties of products arising from the reaction of orthoboric acid with m-phenylene-bismaleimide in melt at 200°C have been studied by spectral and physicochemical methods. The data of IR spectroscopy and thermomechanical analysis suggest that, under the chosen conditions, chemical interaction between the reagents occurs. The conversion increases with the time of reaction and the content of m-phenylene-bismaleimide. High-temperature plasticizers, such as diphenyl and triphenylphosphate, unexpectedly favor formation of more rigid polymer structures, whereas a “temporary plasticizer” (decamethylene glycol) hinders interaction between orthoboric acid and m-phenylene-bismaleimide. The temperature corresponding to a 20% weight loss of the polymer synthesized during heating in air at orthoboric acid: m-phenylene-bismaleimide = 80: 20 is 440–445°C, and the carbon-containing fragments are present in the pyrolysate up to 800°C. The polymer samples retain their shape in air for long time and in water vapor for several days. The hydrolytic stability of the products increases with the content of m-phenylene-bismaleimide.

An investigation of design parameter and atomization mechanism for air shrouded injectors

With increasing requirements for the less harmful exhaust emissions and the better fuel economy, the conventional injectors in gasoline engines can be replaced by the air shrouded injector in order to provide improved combustion in engine operations. To find out the optimal shape of air shrouded atomizer attached to the conventional injector nozzle, the critical design parameters such as droplet size, fuel and air inlet angles, and injection angles were investigated based on experimental analyses. To explain the characteristics of fuel atomization, these experimental approaches were carried out using a Phase Doppler Particle Analyzer (PDPA) system. The droplet sizes of injected air fuel mixture were obtained by using the beam diffraction phenomenon. In order to improve the atomization effect, the various atomizers were investigated. The Sauter Mean Diameter (SMD) measured at the predetermined locations outside the atomizer represented the performance of fuel atomization. The experimental results show that the design factors and atomization mechanism needed for developing air shrouded injectors. The suggested design parameters in this paper can be a useful reference in the early design stage.

SA 기법을 이용한 광디스크 드라이브 공기베어링 슬라이더의 최적설계

The optical storage device has recently experienced significant improvement, especially for the aspects of high capacity and fast transfer rate. However, it is necessary to study a new shape of air bearing surface for the rotary type actuator because the optical storage device has the lower access time than that of HDD (Hard Disk Drives). In this study, we proposed the air bearing shape by using SA (Simulated Annealing) algorithm which is very effective to achieve the global optimum instead of many local optimums. The objective of optimization is to minimize the deviation in flying height from a target value 100nm. In addition, the pitch and roll angle should be maintained within the operation limits.

Theory of eddy currents induced by a nonsymmetric coil above a conducting half-space

A solution is presented for the boundary value problem posed by a current-carrying coil of arbitrary shape in air above the plane surface of a conductor of semi-infinite extent. Two special cases are also treated: a circularly-symmetric coil at an arbitrary tilt angle with respect to the surface normal, and an infinitesimal coil, a magnetic dipole, also at an arbitrary tilt angle. Numerical results are presented for dipole orientations parallel and perpendicular to the surface.

The Transmission of Electromagnetic Waves and Pulses into the Earth

The transmission into the earth of an electromagnetic transient, such as might be generated by a nuclear explosion, is of interest from the point of view of determining the shielding properties of the earth. A plane electromagnetic pulse normally incident on a plane earth is studied as a convenient model. The steady-state transfer function is first evaluated and its properties analyzed for dry, moist, and wet earth over the complete frequency spectrum. The transmission of an incident pulse of Gaussian shape in air is formulated and its shape determined as it enters and advances into the earth. The numerical results determined by a high-speed computer are analyzed and discussed.