Equilibrium theory-based design of simulated moving bed processes under reduced purity requirements linear isotherms

The design of simulated moving bed processes under reduced purity requirements for systems whose isotherm is linear is considered. Based on the equilibrium theory of chromatography, explicit equations to uniquely identify the separation region that will ensure specified extract and raffinate purities are derived. The identification of the region requires only the knowledge of Henry constants of the solutes, the concentration of the solutes in the feed and the purity specifications. These results are validated using numerical simulations.     

Ring of normal cones

Normal categories were introduced by Nambooripad [4], who proved that the set of normal cones in such a category forms a regular semigroup. In this paper, we specialize normal categories to what we call RR-categories, and prove that the set of normal cones in such a category forms a regular ring. As an example, we analyze the regular ring of finite-rank operators on an infinite-dimensional vector space in terms of RR-categories. This example can be realised as the characterisation of a regular ring in terms of its left ideals.     

Forecast-driven model for prepositioning supplies in preparation for a foreseen hurricane

In this paper, we present a forecast-driven dynamic model for prepositioning relief items in preparation for a foreseen hurricane. Our model uses forecast advisories issued by the National Hurricane Center (NHC), which are issued every 6?h. Every time a new advisory is issued with updated information, our model determines the amount and location of units to be prepositioned and it also re-prepositions already prepositioned units. The model also determines the best time for starting the prepositioning activities. Our approach uses a combination of Decision Theory and stochastic programming. The outcomes of our model are presented in a way that could be easily understood by humanitarian practitioners who are ultimately the ones who would use and apply our model.     

On homotopy Poisson actions and reduction of symplectic Q-manifolds

We present a general framework for reduction of symplectic Q-manifolds via graded group actions. In this framework, the homological structure on the acting group is a multiplicative multivector field.     

Two-Stage Flowshop Scheduling Problem with Bicriteria

The two-stage flowshop scheduling problem with the objective of minimizing total flowtime subject to obtaining the optimal makespan is discussed. A branch-and-bound algorithm and two heuristic algorithms have been developed. The results of the experimental investigation of the effectiveness of the algorithms are also presented.     

Multiresidue analytical method for the determination of antimicrobials, preservatives, benzotriazole UV stabilizers, flame retardants and plasticizers in fish using ultra high performance liquid chromatography coupled with tandem mass spectrometry

A multiresidue analytical method for the determination of emerging pollutants belonging to personal care products (PCPs) (antimicrobials, preservatives), benzotriazole UV stabilizers (BUVSs) and organophosphorus compounds (OPCs) in fish has been developed using high speed solvent extraction (HSSE) followed by silica gel clean up and ultra fast liquid chromatography coupled with tandem mass spectrometry (UFLC–MS/MS) analysis. Developed extraction and clean up method yielded good recovery (>70%) for all the four groups of emerging pollutants, i.e. antimicrobials (78.5–85.6%), preservatives (85.0–89.4%), BUVSs (70.9–112%) and OPCs (81.6–114%; except for TEP – 68.9% and TPeP – 58.1%) with RSDs ranging from 0.7 to 15.4%. Intra- and inter-day repeatabilities were less than 19.8% and 19.0%, respectively at three spiked levels. The concentrations were given in lipid weight (lw) basis, and the method detection limits were achieved in the lowest range of 0.001–0.006 ng g⁻¹ for two antimicrobials, 0.001–0.015 ng g⁻¹ for four preservatives, 0.0002–0.009 ng g⁻¹ for eight BUVSs and 0.001–0.014 ng g⁻¹ for nine OPCs. Finally, the method was successfully validated as a simple and fast extraction method for the determination of 23 compounds belonging to PCPs, BUVSs and OPCs and applied to the analysis of three species of fish from Manila Bay, the Philippines. Concentrations ranged from 27 to 278 ng g⁻¹ for antimicrobials, 6.61 to 1580 ng g⁻¹ for paraben preservatives, −1 for BUVSs and ND (not detected) to 266 ng g⁻¹ for OPCs suggesting the ubiquitous contamination by these emerging pollutants in Manila Bay. This is the first method developed for the determination of triclocarban, four paraben preservatives and four BUVSs, in fish.     

Cobalt(II) complexes of terpyridine bases as photochemotherapeutic agents showing cellular uptake and photocytotoxicity in visible light

Cobalt(II) complexes of terpyridine bases [Co(L)?](ClO?)? (1-3), where L is 4'-phenyl-2,2':6',2'-terpyridine (ph-tpy in 1), 4'-(9-anthracenyl)-2,2':6',2'-terpyridine (an-tpy in 2) and 4'-(1- pyrenyl)-2,2':6',2'-terpyridine (py-tpy in 3), are prepared and their photo-induced DNA and protein cleavage activity and photocytotoxic property in HeLa cells studied. The 1?:?2 electrolytic and three-electron paramagnetic complexes show a visible band near 550 nm in DMF-Tris-HCl buffer. The complexes 1-3 show emission spectral bands at 355, 421 and 454 nm, respectively, when excited at 287, 368 and 335 nm. The quantum yield values for 1-3 in DMF-H?O (2?:?1 v/v) are 0.025, 0.060 and 0.28, respectively. The complexes are redox active in DMF-0.1 M TBAP. The Co(III)-Co(II) and Co(II)-Co(I) couples appear as quasi-reversible cyclic voltammetric responses near 0.2 and -0.7 V vs. SCE, respectively. Complexes 2 and 3 are avid binders to calf thymus DNA giving K(b) value of ～10? M?1. The complexes show chemical nuclease activity. Complexes 2 and 3 exhibit oxidative cleavage of pUC19 DNA in UV-A and visible light. The DNA photocleavage reaction of 3 at 365 nm shows formation of singlet oxygen and hydroxyl radical species, while only hydroxyl radical formation is evidenced in visible light. Complexes 2 and 3 show non-specific photo-induced bovine serum albumin protein cleavage activity at 365 nm. The an-tpy and py-tpy complexes exhibit significant photocytotoxicity in HeLa cervical cancer cells on exposure to visible light giving IC?? values of 24.2 and 7.6 μM, respectively. Live cell imaging study shows accumulation of the complexes in the cytosol of HeLa cancer cells.     

High pressure investigations on amorphous selenium

We report the diamond anvil cell (DAC) high pressure powder X-ray diffraction studies on amorphous selenium (a-Se) under truly hydrostatic pressure condition up to 20 GPa. Amorphous selenium exhibits a sharp and irreversible transition to a hexagonal structure at 10.6 ± 0.1 GPa. It is also known that metallization occurs in a-Se around this pressure. Some plausible arguments are provided to suggest that the amorphous to crystalline transition may be driven by metallization.