Enhanced Molecular Orientation Induced by Molecular Anti-Alignment

We explore the role of laser induced anti-alignment in enhancing molecular orientation. A field-free enhanced orientation via anti-alignment scheme is presented, which combines a linearly polarized femtosecond laser pulse with a half-cycle pulse. The laser pulse induces transient anti-alignment in the plane orthogonal to the field polarization, while the half-cycle pulse leads to the orientation. We identify two qualitatively different enhancement mechanisms depending on the pulse order, and optimize their effects using classical and quantum models both at zero and non-zero temperature

Relationships Among Calcium-Dependent Protease, Cathepsins B and H, Meat Tenderness and the Response of Muscle to Aging

This study was conducted to compare the relative importance of Ca-dependent protease (CDP) and cathepsins B and H to meat tenderness and changes in tenderness in response to postmortem cooler aging. Charolais bulls (n = 8) and steers (n = 7) were slaughtered at 15 mo of age, and total activities of CDP-I (a protease with neutral pH optimum that requires micromolar amounts of Ca for activity) and cathepsins B and H (lysosomal proteases with acidic pH optima) were determined within 1 h. Shear-force values were obtained after 1, 3, 6, 9 and 14 d of aging. Data were pooled when analysis of variance revealed no differences between bulls and steers. Initial shear force was correlated (r = -.71, P \u3c .l0, n = 7) to CDP-I activity (only seven animals sampled for CDP-I), and the overall change in shear force (d 1 to d 14) was correlated to cathepsin B (r = .59, P \u3c .05, n = 15). Most of the aging response occurred between d 3 and d 6 (41.6%), and changes in shear force during this period were related to total activities of cathepsins B and H (r = .44, .64, respectively, P \u3c .05). Collectively, cathepsins B and H accounted for 35 and 58% of the variation in shear force change between d 1 to d 14 and d 3 to d 6, respectively. These data suggest that CDP-I helps to establish initial (d 1) meat tenderness but that cathepsins B and H are responsible for the tenderization that occurs during aging. By manipulating live animal growth and postmortem handling, it might be possible to control meat tenderness through the actions of these enzyme systems

Perfect coupling of light to surface plasmons with ultra-narrow linewidths

We examine the coupling of electromagnetic waves incident normal to a thin silver film that forms an oscillatory grating embedded between two otherwise uniform, semi-infinite half spaces. Two grating structures are considered, in one of which the mid point of the Ag film remains fixed whereas the thickness varies sinusoidally, while in the other the mid point oscillates sinusoidally whereas the film thicknesses remains fixed. On reducing the light wavelength from the long wavelength limit, we encounter signatures in the transmission, T, and reflection, R, coefficients associated with: i) the short-range surface plasmon mode, ii) the long-range surface plasmon mode, and iii) electromagnetic diffraction tangent to the grating. The first two features can be regarded as generalized (plasmon) Wood's anomalies whereas the third is the first-order conventional (electromagnetic) Wood's anomaly. The energy density at the film surface is enhanced for wavelengths corresponding to these three anomalies, particularly for the long range plasmon mode in thin films. When exciting the silver film with a pair of waves incident from opposite directions, we find that by adjusting the grating oscillation amplitude and fixing the relative phase of the incoming waves to be even or odd, T+R can be made to vanish for one or the other of the plasmon modes; this corresponds to perfect coupling (impedance matching in the language of electrical engineering) between the incoming light and these modes.Comment: 13 pages, 5 figures. accepted J. Chem. Phy

Choosing and Using a Co-Packer

Co-packing, also known as contract packaging, is when a company contracts with another company to manufacture and package foods that the original company will sell. Products on the market that have been co-packed range from nationally known brands to those sold under private labels. The use of co-packers has become extremely popular with entrepreneurs who have a product idea but lack the $100,000 or more needed to set up a manufacturing facility to produce the product. In addition, many entrepreneurs starting a foods business find that, in today’s market conditions, greater profits are achieved through sales and marketing innovations than by what is done in manufacturing. So, if a company has limited resources, they may get more profit using these resources to develop efficient marketing procedures rather than spending them on setting up manufacturing operations

Monotonically convergent optimal control theory of quantum systems under a nonlinear interaction with the control field

We consider the optimal control of quantum systems interacting non-linearly with an electromagnetic field. We propose new monotonically convergent algorithms to solve the optimal equations. The monotonic behavior of the algorithm is ensured by a non-standard choice of the cost which is not quadratic in the field. These algorithms can be constructed for pure and mixed-state quantum systems. The efficiency of the method is shown numerically on molecular orientation with a non-linearity of order 3 in the field. Discretizing the amplitude and the phase of the Fourier transform of the optimal field, we show that the optimal solution can be well-approximated by pulses that could be implemented experimentally.Comment: 24 pages, 11 figure

Optimal design of nanoplasmonic materials using genetic algorithms as a multi-parameter optimization tool

An optimal control approach based on multiple parameter genetic algorithms is applied to the design of plasmonic nanoconstructs with pre-determined optical properties and functionalities. We first develop nanoscale metallic lenses that focus an incident plane wave onto a pre-specified, spatially confined spot. Our results illustrate the role of symmetry breaking and unravel the principles that favor dimeric constructs for optimal light localization. Next we design a periodic array of silver particles to modify the polarization of an incident, linearly-polarized plane wave in a desired fashion while localizing the light in space. The results provide insight into the structural features that determine the birefringence properties of metal nanoparticles and their arrays. Of the variety of potential applications that may be envisioned, we note the design of nanoscale light sources with controllable coherence and polarization properties that could serve for coherent control of molecular or electronic dynamics in the nanoscale.Comment: 13 pages, 6 figures. submitted to J. Chem. Phy

Laser Induced Selective Alignment of Water Spin Isomers

We consider laser alignment of ortho and para spin isomers of water molecules by using strong and short off-resonance laser pulses. A single pulse is found to create a distinct transient alignment and antialignment of the isomeric species. We suggest selective alignment of one isomeric species (leaving the other species randomly aligned) by a pair of two laser pulses.Comment: 6 pages, 4 figures, 3 table

Utilization Of Spent Fowl In the Manufacture Of Chicken Restructured Steaks

Each year the poultry industry is faced with a large number of spent laying hens (spent fowl), which are often difficult to market at a reasonable price. If less desirable poultry carcasses such as spent hens could be utilized economically to create desirable new products, there would be considerable incentive to do so. Because of the maturity level of spent hens, their muscles are quite tough and, therefore, products made from them would have to be comminuted. A new method of comminution, called flaking, cleanly cuts frozen muscle into wafer—thin slices which aids in the binding properties upon further processing. The manufacture of restructured steaks involves, first, the flaking of meat and, secondly, the pressing of meat into a particular shape. The resulting product should be tender yet simulate the actual eating quality of a real steak. The objective of this study was to determine the optimum levels of white and dark meat required in the formulation of restructured steaks and to examine the feasibility of adding skin and fat to these products

Utilization Of Goose Muscle In The Preparation Of Meat Rolls

South Dakota produces more domestic geese than any other state in the United States. Marketing of geese is decreasing due to importation of Canadian geese and a decreasing consumer demand. Research is needed to increase goose meat consumption. A large percentage of turkey meat is sold as retail convenience products such as rolls, yet there are virtually no comparable products on the market from goose meat. This study was undertaken to develop and evaluate an acceptable goose roll

Squeezing of Atoms in a Pulsed Optical Lattice

We study the process of squeezing of an ensemble of cold atoms in a pulsed optical lattice. The problem is treated both classically and quantum-mechanically under various thermal conditions. We show that a dramatic compression of the atomic density near the minima of the optical potential can be achieved with a proper pulsing of the lattice. Several strategies leading to the enhanced atomic squeezing are suggested, compared and optimized.Comment: Latex, 9 pages, 10 figures, submitted to PR