Stable Immersion Research Articles

Bacillus cereus SN7 Encapsulation process as a substitute protein source in fish feed

Bacillus Cereus SN7 bacteria can inhibit the growth of pathogenic bacteria. Encapsulation is a technology for wrapping the core material in micro-sized capsules that can release their contents in a certain environment. The research aimed to encapsulate the biomass yield as a protection for B. cereus SN7 bacteria from contaminants. This study used an experiment method, namely conducting experiments on the formation of bacterial encapsulation with 2 sources of emulsion: CaCl2 0,1 M and chitosan mixture, 1% acetic acid in 100 ml-1, then tested the effectiveness of encapsulation by looking at the viability of B. cereus SN7 bacteria by counting the number of colonies pH, temperature and physiological aspect of the bacterium. The results of encapsulation studies carried out using emulsion of chitosan mixture, 1% acetic acid in 100 ml- can be formed into capsule beads that can protect bacteria. Meanwhile, using citosan could not last for 75 minutes. After testing the effectiveness of the capsule and its bacterial viability, it is very effective for the production process or for further applications. then the best storage temperature is 100C, pH 5 and stable immersion in physiological solutions.

Hydrostatic pressure effects on corrosion behavior of X70 pipeline steel in a simulated deep-sea environment

Hydrostatic pressure (HP) effects on corrosion process of X70 steel in 3.5% NaCl solution have been investigated by situ electrochemical impedance spectroscopy (EIS), immersion tests and Raman spectra. These results indicate HP affects the corrosion behavior of the X70 steel during the whole immersion period. At the initial immersion, HP promotes the electrochemical reaction of corrosion process. Pitting initiation rate and propagation are both promoted by HP, corrosion rate increases with HP at the initial immersion period. At the stable immersion period, inner layer corrosion product is complete at 0.1 MPa, obvious cracks can be observed at 10 MPa. HP promotes Cl− transport and adsorption on the rust layer, corrosion rate slightly increases with HP.

Stable immersions in orbifolds

We prove that in any hyperbolic orbifold with one boundary component, the product of any hyperbolic fundamental group element with a sufficiently large multiple of the boundary is represented by a geodesic loop that virtually bounds an immersed surface. In the case that the orbifold is a disk, there are some conditions. Our results generalize work of Calegari-Louwsma and resolve a conjecture of Calegari.

A Globally Exponentially Stable Tracking Controller for Mechanical Systems Using Position Feedback

A solution to the problem of global exponential tracking of mechanical systems without velocity measurements is given in the technical note. The proposed controller is obtained combining a redesign of the recently reported exponentially stable immersion and invariance velocity observer and a new state-feedback passivity-based controller, which assigns to the closed-loop a port-Hamiltonian structure with a desired energy function. The result is applicable to a large class of mechanical systems including those with unbounded inertia matrix and possible presence of friction forces. Unlike previous results that rely on the presence-exact knowledge and pervasiveness-of these forces, our design treats them as disturbances, which are suitably compensated.

Study on the Kinetics of Immersion of Photocatalyst in Bamboo

In order to improve the anti-mildew property of modified bamboo with photocatalyst, it used TiO2 which is one of the typical photocatalyst as the main study object to discussed the kinetics of immersion of photocatalyst in bamboo. The results show that immersion of TiO2 in bamboo can be divided into three stages, starting with the rapid immersion, the slow immersion in the middle stage, and the stable immersion in the later stage. In the stable stage, only little TiO2 immerse bamboo. The immersion rate is faster at higher temperature to take less time to reach equilibrium. By establishing the kinetic models, the reaction of immersion of photocatalyst can be regarded as the first order reaction with reaction order of 0.97, the reaction rate constant increases with increasing temperature, the activation energy is 5663.133J/mol, and the pre-exponential factor is 20.47h-1.

Topological invariants of stable immersions of oriented 3-manifolds in [formula omitted

We show that the Z -module of first order local Vassiliev type invariants of stable immersions of oriented 3-manifolds into R 4 is generated by 3 topological invariants: The number of pairs of quadruple points and the positive and negative linking invariants ℓ + and ℓ − introduced by V. Goryunov (1997) [7]. We obtain the expression for the Euler characteristic of the immersed 3-manifold in terms of these invariants. We also prove that the total number of connected components of the triple points curve is a non-local Vassiliev type invariant.

Analysis of Milling Stability by the Chebyshev Collocation Method: Algorithm and Optimal Stable Immersion Levels

In this paper the dynamic stability of the milling process is investigated through a single degree-of-freedom model by determining the regions where chatter (unstable) vibrations occur in the two-parameter space of spindle speed and depth of cut. Dynamic systems such as milling are modeled by delay-differential equations with time-periodic coefficients. A new approximation technique for studying the stability properties of such systems is presented. The approach is based on the properties of Chebyshev polynomials and a collocation expansion of the solution. The collocation points are the extreme points of a Chebyshev polynomial of high degree. Specific cutting force profiles and stability charts are presented for the up- and down-milling cases of one or two cutting teeth and various immersion levels with linear and nonlinear regenerative cutting forces. The unstable regions due to both secondary Hopf and flip (period-doubling) bifurcations are found, and an in-depth investigation of the optimal stable immersion levels for down-milling in the vicinity of where the average cutting force changes sign is presented.

Projectability and uniqueness of F-stable immersions with partially free boundaries

We study immersed critical points X of an elliptic parametric functional F(X) = ? BF(Xu ? Xv)dudv that are spanned into a partially free boundary configuration {G,S} in R3. We suppose that S is a cylindrical support surface and that G is a closed Jordan arc with a simple convex projection. Under geometrically reasonable assumptions on {G,S}, F, and X we prove the projectability and uniqueness of stable immersions. This generalizes a result for minimal surfaces obtained by Hildebrandt and Sauvigny.

Applications of compactness results for harmonic maps to stable constant mean curvature surfaces

for all Lipschitz functions u such that ∫ M u dA = 0. In the above formula ∇ and dA are the gradient and the area element on M and |σ| is the square of the norm of the second fundamental form σ of ψ. We shall call I the index form of the immersion ψ. Note that I (u) is the second variation formula of the area for a normal variation leaving constant the volume functional with variational vector field uν, where ν is a unit vector field normal to the immersion. Complete details can be found in [BdCE]. In this paper we study stable periodic surfaces, i.e., stable immersions ψ : M → R3/Γ , where Γ is a discrete subgroup of translations in R3. These surfaces are interesting since they are good models for naturally occurring periodic phenomena such as the formation of interfaces in block copolymers, see [TAHH] and the references cited there. Up to now, our knowledge of stable immersions in complete flat three manifolds can be resumed in the following result. See [RR] for a sketch of the proof.

Stable complete surfaces with constant mean curvature

Letx:M2→N3 be a stable immersion with constant mean curvatureH of a complete orientable surfaceM2 into a complete oriented three dimensional Riemannian manifoldN3. In this paper we prove that, ifM2 is compact andH2> −1/2 infM RiccN, thenM2 has genusg≤3, here RiccN is the Ricci curvature ofN3. We also prove that, ifM2 is complete non compact andN2 has bounded geometry, the area ofM2 is infinite in the metric induced byx. In this case, ifH2≥−1/2 infM RiccN thenx is umbilic and the equality holds.

Refractive index and absorption coefficient as measures of structural organization in carbonized bitumen

SUMMARYMicroscope photometry has been used to determine reflectances, measured in air and in stable immersion oil, of the carbonized products of the asphaltite bitumen, gilsonite. Comparison of values for parameters (n' and k'), analogous to refractive index and absorption coefficient which are derived from the reflectances, with several X‐ray parameters of the carbonized samples suggests that microscope photometry offers a sensitive alternative method for following changes that take place in the molecular‐structural organization of organic materials during coalification and carbonization processes. Although direct measurement of lattice dimensions is not possible, the optical method is more rapid than X‐ray procedures, is less expensive in terms of capital equipment, while the reflectance measurements can be made on extremely small, discrete and categorically identified field areas, not on the finely ground bulk samples required for X‐ray procedures. Wider application of the microscope photometric method to other carbonized materials and the possibility of absolute correlations between optical and X‐ray data must await more detailed study. The preliminary data are sufficiently encouraging to warrant further extended investigations.

パーマロイ薄膜電着素地として銅および銅合金の予備処理

Various pretreatments of copper and copper alloys (beryllium copper and phosphor bronze) were examined for electroplating of thin permalloy film. Attention was paid to internal stress relieving, surface leveling and adhesion of permalloy film. Heat treatment of the substrate was effective for homogenizing and adhesion of electrodeposited film. The higher temperature for treatment was required for the beryllium copper alloy than for copper or phosphor bronze. Electropolishing was the best method for surface leveling of the substrate. However, the surface of copper alloys was supposed to be covered with an oxide film after the electropolishing from the fact that it took a long time to reach a stable immersion potential. Therefore, the cyanide bath of high pH had to be used for the flush copper plating after the electropolishing. It was found that copper alloys can be used for the substrate of magnetic wires by the application of copper flush plating. The copper flush plating was also very effective for homogenizing of the permalloy film.