Parameterizing above Guaranteed Values: MaxSat and MaxCut

In this paper we investigate the parameterized complexity of the problems MaxSat and MaxCut using the framework developed by Downey and Fellows. LetGbe an arbitrary graph havingnvertices andmedges, and letfbe an arbitrary CNF formula withmclauses onnvariables. We improve Cai and Chen'sO(2^2ckcm) time algorithm for determining if at leastkclauses of ac-CNF formulafcan be satisfied; our algorithm runs inO(|f| + k²φ^k) time for arbitrary formulae and inO(cm + ckφ^k) time forc-CNF formulae, where φ is the golden ratio . We also give an algorithm for finding a cut of size at leastk; our algorithm runs inO(m + n + k4^k) time. We then argue that the standard parameterization of these problems is unsuitable, because nontrivial situations arise only for large parameter values (k ≥ m/2), in which range the fixed-parameter tractable algorithms are infeasible. A more meaningful question in the parameterized setting is to ask whether m/2 + kclauses can be satisfied, or m/2 + kedges can be placed in a cut. We show that these problems remain fixed-parameter tractable even under this parameterization. Furthermore, for up to logarithmic values of the parameter, our algorithms for these versions also run in polynomial time.     

Solvent volume-driven CuInAlS2 nanoflake counter electrode for effective electrocatalytic tri-iodide reduction in dye-sensitized solar cells

Journal of Solid State Electrochemistry - The influence of solvent volume on the properties of CuInAlS2 (CIAS) thin films deposited using simple and cost-effective nebulizer spray technique is...     

Spectroscopic study of rigid-rod polymers. II. Protonation effect

The protonation of a heterocyclic rigid-rod polymer poly(p-phenylene benzbisthiazole) and its model compound has been studied by UV-visible and Raman spectroscopy. Because of the two nitrogens on the heterocyclic ring, spectroscopic features of unprotonated, half-protonated, and fully protonated structures have been identified. For the fully protonated molecule, there is also an increase in conjugation between the phenyl ring and the heterocyclic ring.     

Infrared spectroscopic study of solvent-induced structural changes in poly(ethylene terephthalate) film

It is found from polarized infrared spectroscopy that treatment of oriented poly(ethylene terephthalate) (PET) film with strongly interacting solvents such as s-tetrachloroethane, nitrobenzene, dimethylformamide, and benzyl alcohol results in disorientation of polymer chains. Partial transformation from trans to gauche conformation takes place on thermal treatment and, to a larger extent, on solvent treatment. Increasing sharpness of the 988 cm^?1 band on solvent treatment indicates the formation of regular chain folds. Some new spectral features are discussed.     

Multipurpose biological reference materials

Summary Reference materials to meet multipurpose needs for analysis of both inorganic and organic constituents in biological investigations are not readily available. A human total diet material is being investigated as a reference material for a wide variety of constituents of interest to human nutrition and health. This material shows a stable assay value for the natural levels of a number of vitamins following freeze-drying or radiation sterilization. This is an important feature in producing materials for long term stability as a Reference Material for natural levels of these constituents. An exception is an increase of 34% in assay value of folic acid upon freeze-drying and an 85% increase upon freezedrying followed by radiation sterilization.

---

Vielseitig verwendbare biologische Referenzmaterialien

     

Crystal structure of 12-methoxy-8,8,21,21-tetramethyl-5-(3-methylbut-2,4-dienyl)-19-(3-methylpent-4-enyl)-3,7,20-trioxahexacyclo[15.4.1.0<2,15>.0<2,19>.0<4,13>.0<6,11>]docosa-4(13),5,9,11,15-pentaene-14,18-dione.

The title compound was extracted from the natural product of plant origin. It crystallizes in tetragonal space group P4(1) or P4(3), with cell parameters a = 15.795(2)A, c = 11.970(5)A and Z = 4. The structure exhibits intermolecular hydrogen bonds of the type C-H...O.     

Total iodine in nutritional and biological reference materials using neutron activation analysis and inductively coupled plasma mass spectrometry

In a recent collaborative study intended to extend the variety of reference materials certified for iodine, three mineralization methods were developed to quantify the total iodine content of biological and nutritional materials by inductively coupled plasma mass spectrometry (ICP-MS). A mixture of water-soluble tertiary amines was used as the matrix solution for two oxygen combustion methods and for a simple extraction at room temperature. Calibrations with matrix-matched standards, internal calibration, and isotope dilution with ¹²⁹I were used. Good agreement between neutron activation analysis (NAA) and the two combustion methods was observed except for < 0.1 mg kg^–1 iodine concentrations. The amine extraction method gave the most reliable results for the mixed diet, milk powder, and infant formula samples but low recoveries for other biological materials owing to an incomplete extraction and solubilization of iodine. The NAA method, with its freedom from reagent blank, is a useful technique for the independent determination of iodine in biological, environmental and food matrices, especially for verification of iodine results obtained by ICP-MS.     

Characterization of ligno-cellulosic seed fibre from Wrightia Tinctoria plant for textile applications—an exploratory investigation

A hitherto uninvestigated ligno-cellulosic seed fibre from the plant Wrightia Tinctoria has been chosen for the current study to unravel its physical properties, and potentialities in textile applications. Both raw and partially delignified fibres were tested for their morphological and structural features by X-ray diffraction, optical microscope and FT-IR spectra, thermal properties by thermogravimetry and differential scanning calorimetry and fibre fineness properties. The non-spinnable brittle virgin fibre becomes spinnable after partial delignification due to the decreased fibre rigidity imparted by lignin. Knitted fabrics were made successfully with (20%) and without cotton blending.     

A radioimmunoassay for serum estradiol

A radioimmunoassay procedure to measure estradiol levels in human serum was developed using¹²⁵I labeled estradiol and antiestradiol antibody raised in-house using the estradiol-6-CMO-BSA as the immunogen. Controlled process serum was used to maintain the serum matrix and sample-standard identity. The assay was validated by analysing several (n=40) samples and comparing with established commercial assays. The assay had a sensitivity of 35 pg/mL and a range of 50 pg/mL to 5 ng/mL. The interassay C.V. were between 2 to 10% while the intraassay C.V. were between 2 and 8%. This assay is sensitive enough for monitoring ovulation and hypersecretions in ovarian tumours and was primarily developed to be used as an in-house assay in the local hospitals.