Studies on chemically modified cotton. V. Effect of zinc chloride solutions on swelling and other properties of cotton

This paper describes the effect of zinc chloride solutions of different molarity at different temperatures, viz., 10°, 25°, 36°, 55°, and 75°C, on various properties of cotton fiber such as degree of swelling, accessibility to water vapor and iodine absorption, infrared ratio, barium activity number (BAN), and leveling-off degree of polymerization (LODP). Zinc chloride solution caused inter- and intrafibrillar swelling in cotton fiber depending on conditions of treatment, viz., concentration of solution and temperature employed. Fibers treated in 10.07 moles/1. (M) solution of zinc chloride in slack state showed rapid increase in degree of swelling up to 2 hr, followed by a slow increase, reaching the maximum after 3 hr of treatment. Fibers swollen with fixed ends without allowing shrinkage showed gradual increase with maximum swelling after 6 hr of treatment. Cotton fibers treated in different molar solutions of zinc chloride at 55°C showed varying degrees of swelling (inter- and intrafibrillar) and a somewhat different trend compared to that observed at 10°C. Electron micrographs revealed mostly intercrystalline swelling in case of samples treated with 9.26M at 10°C, while the same concentration produced intracrystalline swelling at 55°C. Accessibility to water vapor, iodine absorption, and BAN of treated samples showed specific effect of temperature with regard to effectiveness of concentrations of zinc chloride solutions. Similar effects of temperature with regard to concentrations of reagent were observed on infrared ratio and LODP. Accessibility by iodine absorption and LODP correlate with BAN; also, the accessibility by iodine absorption correlates with the LODP.     

The communication system

The paper discusses the salient features of system design considerations for both uplink and downlink, subsystem details and the in-orbit performance of the communication system forAryabhata.     

Traditional Kerala style fish curry in indigenous retort pouch

Fish curry processed in metal cans is popular in the overseas markets. An important limitation with the use of metal cans is the undesirable taste imparted to the products on storage. Flexible pouches are an ideal alternative to metal cans. Extensive work carried out at Central Institute of Fisheries Technology has been able to identify indigenous pouches, which are as good as imported pouches. This has been done after collecting different types of indigenous and imported flexible pouches, analyzing their composition and conducting detailed studies on their physical and food contact application properties. Two indigenous pouches with composition 12 micron polyester/12 micron aluminium foil/87.5 micron cast polypropylene and 12 micron polyester/15 micron aluminium foil/70 micron cast polypropylene have been selected and got made by indigenous laminators and an imported one with configuration 12 micron polyester/15 micron aluminium foil/75 micron cast polypropylene were used for further experiment on processing fish curry. Traditional Kerala style mackerel fish curry was processed in the retort pouches of the above configurations. About 220 g fish curry was packed in each pouch (15.5 cm×7 cm). Process requirements were worked out by measuring heat penetration using thermocouples introduced into the pouches. Fish curry processed to a F₀ value of 8.43 gave an acceptable product with desired texture and sensory characteristics. The physical properties of the pouches studied showed that the indigenous pouches of the above configurations were good enough to give a shelf life of 1 year at room temperature. The curry remained sterile throughout the storage period at ambient temperature (25–30°C) and retained acceptable sensory characteristics.     

Adaptive sampling scheme for monitoring oscillations using Prony analysis

Monitoring generator oscillations using Prony analysis is an application that is being increasingly implemented using phasor measurement units (PMUs) data. Most of the existing literature for power system oscillations using Prony method report implementing fixed sampling window that is obtained following a systematic iterative approach taking into account potential disturbances. The fixed sampling technique, although simple to implement, does not optimise the data acquisition time. Moreover, sampling using inadequate intervals can potentially lead to errors during Prony analysis. In this study mathematical formulations are derived to show the effect of small and large sampling intervals. Further, a technique using condition number is proposed as a quality index for signalling the errors arising because of the choice of sampling interval. To facilitate an efficient monitoring rate, while still maintaining sufficient accuracy, an adaptive sampling scheme is proposed. This study demonstrates that the proposed scheme can potentially exhibit faster monitoring rate with acceptable accuracy during practical implementation.     

Thermal behaviour of strontium tartrate single crystals grown in gel

Thermal behaviour of strontium tartrate crystals grown with the aid of sodium metasilicate gel is investigated using thermogravimetry (TG) and differential thermal analysis (DTA). Effect of magnetic field and dopant (Pb)²⁺ on the crystal stability is also studied using thermal analysis. This study reveals that water molecules are locked up in the lattice with different strengths in the grown crystals.     

Bone tumors of the coracoid process of the scapula

Bone tumors of the coracoid process of the scapula are rare, and diagnosis and treatment often are delayed. The records of 18 patients with bone tumors of the coracoid process were reviewed. Histologic types included eight cases of ordinary chondrosarcoma, three cases of dedifferentiated chondrosarcoma, two cases of osteoid osteoma, and one case each of osteosarcoma, plasmacytoma, lymphoma, giant cell tumor, and aneurysmal bone cyst. All 18 patients had shoulder pain, and eight of them had been treated with steroid injections for nonneoplastic conditions. Radiologically, chondrosarcoma did not always show clear cortical destruction, and one giant cell tumor had features mimicking those of chondrosarcoma. Five patients (three with dedifferentiated chondrosarcoma, one with chondrosarcoma, one with plasmacytoma) died of disease. The coracoid process was the site with a markedly high proportion of chondrosarcomas. Bone tumors of the coracoid process may be difficult to detect on plain radiographs. In the patient with persistent shoulder pain unresponsive to the selected treatment, additional imaging studies should be considered to eliminate the possibility of a bone lesion.     

Methodology for feedback variable selection for control of semiconductor manufacturing processes - Part 2: Application to reactive ion etching

The PVVM methodology for feedback variable selection introduced in a companion paper (Patterson et al., 2003) is applied to a gate etch process. The primary purpose of this paper is to illustrate the practical aspects of utilizing this methodology. Particular attention is given to the challenging task of process modeling. The model-building procedure and constraint-limited exhaustive search is demonstrated to perform superior to other model-building procedures including principal component regression and partial least squares regression for use in this methodology. A second purpose is to present the results for the etch process. Advanced sensors considered for real-time process control of this process include an RF probe, mass spectroscopy and optical emission spectroscopy. Feedback variables are selected to reduce variation in etch rate, nonuniformity and lateral etch rate. The advantages of treating location on the wafer as a disturbance to the etch rate model so that both etch rate and nonuniformity may be captured in one model are presented and experimentally verified.     

An eco‐efficient rationalized leather process

BACKGROUND: The leather industry is under pressure to develop environmentally efficient leather‐making processes to comply with modern pollution and discharge legislation. Conventional leather‐processing methods are known to contribute significant pollution loads in tannery wastewaters. The rationalized process described here involves a salt‐free curing, lime and sulfide‐free beamhouse process and post‐tanning followed by tanning employing a reverse leather‐processing technique. RESULTS: Scanning electron microscopy (SEM) analysis substantiated that the grain surface, fibre separation and tight packing of fibres are similar for leathers from conventional and rationalized processes. The functional performance of the leathers is found to be on par with that of conventionally processed leathers. The rationalized leather process reduces the usage and discharge of chemicals by 68% and 82%, respectively. It also enjoys the reduction in biochemical oxygen demand (BOD), chemical oxygen demand, Cl^?, SO₄^2? and total solids loads by 58%, 62%, 95%, 66% and 85%, respectively. The rationalized process also results in reduction of water consumption and discharge and energy by 37%, 37% and 38%, respectively. CONCLUSION: The rationalized process utilizes resources efficiently with reduced environmental impact without compromising leather qualities and can be seen as being eco‐efficient compared to the conventional leather process. Copyright © 2007 Society of Chemical Industry