Superior non-woven sheet forming characteristics of low-density cationic polymer-cellulose nanofibre colloids

This work examines the addition of cationic polymers, cationic polyacrylamide (CPAM) and polyamide–amine–epichlorohydrin (PAE), to cellulose nanofibres to produce superior forming characteristics. The addition of 2 mg of high MW CPAM/g of nanofibres halved the drainage time to under 1 min at 0.1 wt% solids content due to increasing the floc size and the fibre forming a bulky and porous filter medium during drainage. The more open structure created in the wet state was partially preserved during the drying process, reducing the sheet density from 760 to 680 kg/m³, at the highest level of polymer addition. The addition of CPAM resulted in significant additional bridging between nanofibres, which then substantially increased the non-uniformity of the filter medium. PAE addition at 10 mg/g of micro fibrillated cellulose (MFC), also reduced drainage time, while increasing retention, but without changing the sheet uniformity. Wet strength increased continuously with PAE addition level, reaching 31.6 kN m/kg at the highest level of 20 mg of PAE/g of MFC.     

Study on using high injection voltage and spiral inflector in the central region of VEC

A feasibility study of using high injection voltage and spiral inflector in the present heavy ion central region of VEC is described. Conditions necessary for waist-to-waist transfer of the ion beam in the hole lens of main magnet have been obtained. The results of orbit studies of a variety of heavy ions indicate that a spiral inflector can be used in the central region.     

Intensity and transmission measurements in the ν3-fundamental of N2O at low temperatures

Spectral transmission of i.r. radiation through the nitrogen-broadened lines of the υ₃-fundamental of N₂O has been measured at 154°, 202° and 300°K. A value of S⁰_v = 1411±54 cm^-2atm^-1 at S.T.P. has been obtained for the combined strength of the ν₃ and ν₂¹+ν₃?ν₂¹ bands using the Wilson-Wells-Penner-Weber method. This value for S_v, the relative intensity calculations of Gray Young, the room-temperature data of Toth for nitrogen-broadened half-widths in the ν₁+ν₃ and 2ν₂⁰+ν₃ bands and the T^-0.75 variation of line width with temperature proposed by Varanasi and Sarangi are shown to yield excellent agreement between the measured and computed spectral transmittance throughout the band.     

Absorption by self-broadened rotational lines in the v4-fundamental of 12CH4

Spectral transmission measurements at 300°K in the v₄-fundamental of ¹²CH₄ are presented for pure samples of the gas. A line-by-line computation using S⁰_v = 145 cm^-2 atm^-1 at STP, measured by us earlier, is in good agreement with the present data on self-broadened lines.     

Development of Injectable Biodegradable Multi-Arms PEG-Based Hydrogels: Swelling and Degradation Investigations

Summary : Injectable biodegradable hydrogels have been developed to determine the efficacy of biomaterials for the treatment of periodontitis through control delivery of bone-healing bioactives. The hydrogels were prepared from the PEG-ylated macromer of Boltorn™ H20 (BH20) and an acrylated triblock copolymer of polylactide-polyethylene glycol (2k)-polylactide (PLA) in various molar ratios using ammonium persulfate and sodium ascorbate as a free radical initiating system. Preliminary investigations involving the synthesis of PLA hydrogels with different PLLA block lengths were studied in order to determine the swelling ratios and degradation rates of the biodegradable component of the hydrogels prior to copolymerization with BH20. The swelling and degradation studies of PLA with PEG diacrylate (FW 700) hydrogels were established in phosphate buffered saline (PBS) at 37 °C, pH 7.4 and in water (pH ∼5.5). They have been shown to have low swelling ratios (Q_max = 4.4 to 3.6) and degradation times of 20–30 days. The swelling and degradation parameters were found to be dependent on the molar ratio of the PEG diacrylate to PLA in the copolymer.     

Thermal infrared lines of methane broadened by nitrogen at low temperatures

Measurements of spectral transmittance in the v₄-fundamental band of ¹²CH₄ have been performed at low temperatures using a Fourier transform spectrometer with apodized spectral resolution of 0.06 cm^-1. With applications to lines formed in the atmospheres of Titan and Earth in mind, N₂ has been used as the broadening gas. Comparisons of observed and computed spectral transmittances on a line-by-line basis have yielded line strengths, N₂-broadened half-widths and their variation with temperature. Best agreement between measured and computed spectra was obtained when the absolute intensity of the band was taken as 128 cm^-2-atm^-1 at 296 K. Line widths were found to vary as Tⁿ with n = -1.0 for lines of the F-species and 0.63 for the A-species. Our measured line widths are considerably larger than those used in the AFGL compilation.     

Measurement of line intensities of linear molecules under low resolution

By using the relation k_v?S_J/δ_J applicable at sufficiently high pressures, at which the rotational fine structure in a band is smeared out completely, line intensities S_J may be determined from measured spectral absorption coefficients and known local line spacings δ_J. First, the validity of the approximation is ascertained by comparing the spectral absorption coefficient data of Penner and Weber and of Varanasi and Penner for the fundamental bands of CO and NO, respectively, with S_J/δ_J derived from the high resolution measurements of Benedict et al. (for CO) and of Abels and Shaw (for NO). Line intensity data obtained using this method are in good agreement with the high-resolution measurements of Toth (grating spectroscopy) for some unblended lines in the 00°0?02°1 band of N₂O and of Lacome et al. (laser- spectroscopy) for lines in the 10°0?00°1 band of N₂O.     

On the determination of the quadrupole moment of oxygen from self-broadened line widths in the microwave spectrum

The large discrepancy between the value 0·4 D Å measured by Buckingham for the quadrupole moment of oxygen and the recent value 1·21 D Å used by Yamamoto and Cattani and by Bouanich in line-broadening calculations is examined. When hexadecapolar and repulsive interactions are included, the discrepancy in the values of the quadrupole moment obtained by the bi-refringence method and line width calculations is resolved provided a value of Φ ～ 8 D ų is used for the hexadecapole moment of oxygen.     

Unsteady motion of receding contact lines of surfactant solutions: the role of surfactant re-self-assembly

Re-self-assembly of surfactant molecules must occur at moving contact lines of soluble surfactant solutions. Molecules are transported into and out of the contact line region from four sources: the three interfaces meeting at the contact line and the fluid confined between the solid-liquid and liquid-vapor interfaces. As molecules move among these sources at the contact line, they must rearrange. The dynamics of this re-self-assembly has been shown to have a dominating effect on the structure of advancing contact lines, causing unsteady motion and complex structure of the contact line. It might be assumed that the re-self-assembly for receding contact lines leads to more steady contact line movement. However, in this article we show that for a wide variety of systems this is not true. Quasi-static distortions of the contact line occur as it retreats because of the inability of the surfactant to completely re-self-assemble at localized positions along the contact line.     

The Role of Lignocellulosic Composition and Residual Lipids in Empty Fruit Bunches on the Production of Humic Acids in Submerged Fermentations

The aim of this research was to study the production of humic acids (HA) by Trichoderma reesei from empty fruit bunches (EFBs) of palm oil processing, with a focus on the effects of lignocellulosic content and residual lipids. EFBs from two different soils and palm oil producers were previously characterized about their lignocellulosic composition. Submerged fermentations were inoculated with T. reesei spores and set up with or without residual lipids. The results showed that the soil and the processing for removal of the palm fresh fruits were crucial to EFB quality. Thus, EFBs were classified as type 1 (higher lignocellulosic and fatty acids composition similar to the palm oil and palm kernel oil) and type 2 (lower lignocellulosic content and fatty acids composition similar to palm oil). Despite the different profiles, the fungal growth was similar for both EFB types. HA production was associated with fungal growth, and it was higher without lipids for both EFBs. The highest HA productivity was obtained from type 1 EFB (approximately 90 mg L⁻¹ at 48 h). Therefore, the lignocellulosic composition and the nature of the residual lipids in EFBs play an important role in HA production by submerged fermentation.