Effect of driving laser intensity fluctuations on optical bistability of a system with large permanent-dipole molecules

The statistical properties of an optical bistable system consisting of two-level atoms with large permanent dipole moments contained in a Fabry-Perot cavity are investigated assuming the external laser intensity fluctuations to be the main source of noise. The probability transformation rule is applied to obtain the probability distribution for the transmitted intensity whereas the probability distribution for the incident intensity is assumed to be that of the partially coherent laser light. It turns out that in the optical bistability region two values of fluctuation parameters are possible for a given value of input intensity, which produces interesting hysteresis effects.     

Inhibition Effects of Dilute-Acid Prehydrolysate of Corn Stover on Enzymatic Hydrolysis of Solka Floc

Dilute-acid pretreatment liquor (PL) produced at NREL through a continuous screw-driven reactor was analyzed for sugars and other potential inhibitory components. Their inhibitory effects on enzymatic hydrolysis of Solka Floc were investigated. When the PL was mixed into the enzymatic hydrolysis reactor at 1:1 volume ratio, the glucan and xylan digestibility decreased by 63% and 90%, respectively. The tolerance level of the enzyme for each inhibitor was determined. Of the identified degradation components, acetic acid was found to be the strongest inhibitor for cellulase activity, as it decreased the glucan yield by 10% at 1 g/L. Among the sugars, cellobiose and glucose were found to be strong inhibitors to glucan hydrolysis, whereas xylose is a strong inhibitor to xylan hydrolysis. Xylo-oligomers inhibit xylan digestibility more strongly than the glucan digestibility. Inhibition by the PL was higher than that of the simulated mixture of the identifiable components. This indicates that some of the unidentified degradation components, originated mostly from lignin, are potent inhibitors to the cellulase enzyme. When the PL was added to a simultaneous saccharification and co-fermentation using Escherichia coli KO11, the bioprocess was severely inhibited showing no ethanol formation or cell growth.     

On the group-theoretic structure of a class of quantum dialogue protocols

A sufficient condition for implementation of the quantum dialogue protocol is obtained and it is shown that the set of unitary operators used for the purpose must form a group under multiplication. A generalized protocol of quantum dialogue is obtained using the sufficient condition. Further, several examples of possible groups of unitary operators and quantum states that may be used for implementation of quantum dialogue are systematically generated. As examples, it is shown that GHZ state, GHZ-like state, W state, 4 and 5-qubit Cluster states, Ω   state, Brown state, _Q4$Q_4$ state and _Q5$Q_5$ state can be used to implement quantum dialogue protocol. It is also shown that if a quantum system is found to be suitable for quantum dialogue then that can provide solution of the socialist millionaire problem too.     

Tabu search for the single row facility layout problem using exhaustive 2-opt and insertion neighborhoods

The single row facility layout problem (SRFLP) is the problem of arranging facilities with given lengths on a line, while minimizing the weighted sum of the distances between all pairs of facilities. The problem is NP-hard. In this paper, we present two tabu search implementations, one involving an exhaustive search of the 2-opt neighborhood and the other involving an exhaustive search of the insertion neighborhood. We also present techniques to significantly speed up the search of the two neighborhoods. Our computational experiments show that the speed up techniques are effective, and our tabu search implementations are competitive. Our tabu search implementations improved previously known best solutions for 23 out of the 43 large sized SRFLP benchmark instances.     

Effects of linear absorption on the steady-state behavior of a photorefractive phase-conjugate mirror

A photorefractive phase-conjugate mirror with linear absorption is examined. An objective of this study is to identify possible effects of absorption on the self-oscillation conditions of the mirror and the properties of the excited conjugate wave. It has been found that self-oscillation is still possible in the presence of absorption. However, the coupling coefficient required for self-oscillation must increase in magnitude with increasing absorption coefficient to counteract the depressing effects of absorption. A consequence of self-oscillation in the presence of absorption is enhancement of the mirror reflectivity. A parametric study of the absorption-enhanced mirror is presented.The authors wish to acknowledge the contributions of Dai Sieh during the initial phase of this study. The work that he completed as part of his Master of Science thesis was an important element in our study of PCM reflectivity enhancement. The authors also acknowledge the assistance of Sahaid Rauf in carrying out some of the numerical solutions of Eq. 10, the governing equation of the self-oscillatory modes.     

Enhancement ofSpirulina biomass productivity by a protein hydrolysate

The effect of a hydrolyzed protein preparation on the growth and biomass yield of the blue-gree algaSpirulina platensis was studied. At the optimum dosage, the hydrolysate enhancedSpirulina productivity by almost 40% when compared to untreated cultures. This increased productivity correlated with an increase in the level of nitrogen assimilating enzymes, nitrate reductase and glutamine synthetase.     

Enantiospecific electrodeposition of chiral CuO films on single-crystal Cu(111)

Epitaxial films of monoclinic CuO have been electrodeposited on single-crystal Cu(111) from solutions containing either (S,S)- or (R,R)-tartrate. X-ray pole figure analysis reveals that the CuO film grown from (S,S)-tartrate exhibits a (1) out-of-plane orientation while the film grown from (R,R)-tartrate has a (11) orientation. Even though CuO does not crystallize within a chiral space group, the orientations obtained exhibit a surface chirality similar to that obtained from high index fcc metal surfaces. The films were shown to be enantioselective toward the catalytic oxidation of tartrate molecules by cyclic voltammetry. The technique should prove to be applicable to the electrodeposition of chiral surfaces of other low-symmetry materials on achiral substrates and should prove to be of use to those interested in the synthesis, separation, and detection of chiral molecules.     

Preparation and characterization of125I labeled progesterone derivatives for the development of a radioimmunoassay for progesterone

Preparation and purification of radioiodinated progesterone derivatives for the development of a radioimmunoassay of progesterone is described. We have standardized two procedures for preparing radioiodinated progesterone conjugate. In the first procedure¹²⁵I labeled histamine was conjugated to progesterone 11 hemisuccinate by the mixed anhydride method. In the secod procedure, tyrosyl methyl ester was conjugated to progesterone 11 hemisuccinate and iodination of the conjugate was carried out. Purification of the iodinated products was carried out by solvent extraction and thin layer chromatography techniques. The radiochemical purity of the tracers prepared by both methods were more than 95%. Labeled progesterone derivatives prepared were used for developing a radioimmunoassay procedure. The non-specific binding of the tracer was about 2–3%, while up to 80% binding could be obtained in the presence of excess antibody. The radioiodinated tracer could be used up to four months in the assay.