6,103 research outputs found
Flexible parylene actuator for micro adaptive flow control
This paper describes the first flexible parylene electrostatic actuator valves intended for micro adaptive flow control for the future use on the wings of micro-air-vehicle (MAV). The actuator diaphragm is made of two layers of parylene membranes with offset vent holes. Without electrostatic actuation, air can move freely from one side of the skin to the other side through the vent holes. With actuation, these vent holes are sealed and the airflow is controlled. The membrane behaves as a complete diaphragm.
We have successfully demonstrated this function using a 2-mm x 2-mm parylene diaphragm electrostatic actuator valves. This work also includes the novel anti-stiction technology that is crucial to make such large-area parylene actuator diaphragm with the combined use of anti-stiction posts, self-assembled monolayers (SAM), surface roughening, and bromine trifluoride (BrFe) dry etching. With the help of SAM treatment, the operating voltage is lowered from 30 volts to 13 volts. The load deflection method is then used to measure the effective thickness of the composite
diaphragm. The flexible parylene diaphragm can be deflected up to 100 μm when 150 Torr of pressure is applied. The result is fitted into a theoretical model and yields an effective thickness of 5.9 μm, which is agreeable with the actual thickness of 5.6 μm, thus proves the functionality of the device
A practical multi-spectrum Hadamard Transform Spectrometer
A Hadamard Transform Spectrometer (HTS) which simultaneously obtains fifteen infrared spectra, each having 255 spectral elements was constructed. Spectra are obtained essentially in real time through use of a minicomputer with 8K words of memory and a CRT display. This permits operation of the instrument in the field
A two-state model for helicase translocation and unwinding of nucleic acids
Helicases are molecular motors that unwind double-stranded nucleic acids
(dsNA), such as DNA and RNA). Typically a helicase translocates along one of
the NA single strands while unwinding and uses adenosine triphosphate (ATP)
hydrolysis as an energy source. Here we model of a helicase motor that can
switch between two states, which could represent two different points in the
ATP hydrolysis cycle. Our model is an extension of the earlier
Betterton-J\"ulicher model of helicases to incorporate switching between two
states. The main predictions of the model are the speed of unwinding of the
dsNA and fluctuations around the average unwinding velocity. Motivated by a
recent claim that the NS3 helicase of Hepatitis C virus follows a flashing
ratchet mechanism, we have compared the experimental results for the NS3
helicase with a special limit of our model which corresponds to the flashing
ratchet scenario. Our model accounts for one key feature of the experimental
data on NS3 helicase. However, contradictory observations in experiments
carried out under different conditions limit the ability to compare the model
to experiments.Comment: minor modification
Minimizing the Cost and Enhancing the Security for Cloud Hosting Service
Cloud computing is a new emerging technology which provides different kinds of services through internet and reduces maintenance cost as well as provides data reliability. Now a days many cloud service providers are providing services with different policies and prices. But it leads difficult to customers to choose cloud services with less price. That clients as a rule put their information into a single cloud and after that just trust to luckiness. Proposing new data hosting technique termed as CHARM which supports two strong functionalities.The first is selecting a few suitable clouds and a fitting excess system to store information with minimized financial expense and ensured accessibility.The second is setting off a move procedure to re-disperse information as indicated by the varieties of information access example and evaluating of clouds.In this project defining secret sharing algorithm to reduce the risk of data intrusion and the loss of service availability in the cloud and ensure data integrity. Finally proposed scheme not only saves the cost and also Maintains data and price adjustments
Non-magnetic impurities in two- and three- dimensional Heisenberg antiferromagnets
In this paper we study in a large-S expansion effects of substituting spins
by non-magnetic impurities in two- and three- dimensional Heisenberg
antiferromagnets in a weak magnetic field. In particular, we demonstrate a
novel mechanism where magnetic moments are induced around non-magnetic
impurities when magnetic field is present. As a result, Curie-type behaviour in
magnetic susceptibility can be observed well below the Neel temperature, in
agreement with what is being observed in and
compounds.Comment: Latex fil
The Influence of Observation Errors on Analysis Error and Forecast Skill Investigated with an Observing System Simulation Experiment
The Global Modeling and Assimilation Office (GMAO) observing system simulation experiment (OSSE) framework is used to explore the response of analysis error and forecast skill to observation quality. In an OSSE, synthetic observations may be created that have much smaller error than real observations, and precisely quantified error may be applied to these synthetic observations. Three experiments are performed in which synthetic observations with magnitudes of applied observation error that vary from zero to twice the estimated realistic error are ingested into the Goddard Earth Observing System Model (GEOS-5) with Gridpoint Statistical Interpolation (GSI) data assimilation for a one-month period representing July. The analysis increment and observation innovation are strongly impacted by observation error, with much larger variances for increased observation error. The analysis quality is degraded by increased observation error, but the change in root-mean-square error of the analysis state is small relative to the total analysis error. Surprisingly, in the 120 hour forecast increased observation error only yields a slight decline in forecast skill in the extratropics, and no discernable degradation of forecast skill in the tropics
Overcoming of Information Extremism as a Condition of Human and Social Wellbeing
The urgency of this research is indisputable because the subjects of information extremism having at their disposal various mass media can disseminate their beliefs and ideas over thousands of people in different countries all over the world. International collaboration is needed to struggle against this evil. The paper provides deep insight into the notion "information extremism", as well as its classification and forms. It is aimed at revealing the specific character of the notions "information extremism" and "information terrorism" and their investigation. Illocutionary influence as the major method of information extremism is highlighted in the paper. The authors demonstrate important influence of mass media including the Internet over readership, especially the youth. It is concluded that the issue of information extremism requires for more rigorous and deeper consideration. It is necessary to fight against forms of its manifestation, because they have a significant effect on homeland and international safety and stability
Uniformization, Calogero-Moser/Heun duality and Sutherland/bubbling pants
Inspired by the work of Alday, Gaiotto and Tachikawa (AGT), we saw the
revival of Poincar{\'{e}}'s uniformization problem and Fuchsian equations
obtained thereof.
Three distinguished aspects are possessed by Fuchsian equations. First, they
are available via imposing a classical Liouville limit on level-two null-vector
conditions. Second, they fall into some A_1-type integrable systems. Third, the
stress-tensor present there (in terms of the Q-form) manifests itself as a kind
of one-dimensional "curve".
Thereby, a contact with the recently proposed Nekrasov-Shatashvili limit was
soon made on the one hand, whilst the seemingly mysterious derivation of
Seiberg-Witten prepotentials from integrable models become resolved on the
other hand. Moreover, AGT conjecture can just be regarded as a quantum version
of the previous Poincar{\'{e}}'s approach.
Equipped with these observations, we examined relations between spheric and
toric (classical) conformal blocks via Calogero-Moser/Heun duality. Besides, as
Sutherland model is also obtainable from Calogero-Moser by pinching tori at one
point, we tried to understand its eigenstates from the viewpoint of toric
diagrams with possibly many surface operators (toric branes) inserted. A
picture called "bubbling pants" then emerged and reproduced well-known results
of the non-critical self-dual c=1 string theory under a "blown-down" limit.Comment: 17 pages, 4 figures; v2: corrections and references added; v3:
Section 2.4.1 newly added thanks to JHEP referee advice. That classical
four-point spheric conformal blocks reproducing known SW prepotentials is
demonstrated via more examples, to appear in JHEP; v4: TexStyle changed onl
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