Instron texture profile of buffalo milk cheddar cheese as influenced by composition and ripening changes

Buffalo milk Cheddar cheese samples of different ages were analysed for compositional attributes (CA), ripening indices (RI) and Instron Textural Profile (ITP). All samples were compositionally alike, except for pH and salt-in-moisture (SM) contents. RI showed significant variations. CA and RI showed highly significant correlations within themselves and with each other, except for moisture with pH, SM with moisture, MNFS, Fat and FDM and Fat with MNFS. The ITPs of cheeses showed significant variations and had highly significant intercorrelations indicating their interdependence. CA (except moisture and MNFS) and RI showed a highly significant correlationship with ITPs. Moisture content showed a highly significant correlationship with all ITPs, except cohesiveness and springiness, where it was significant. MNFS content showed significant correlations only with hardness and brittleness. Stepwise regression analysis revealed that MI was the most predominant factor influencing cheese texture, followed by pH, SM, FDM and TVFA. Knowing Ca and RI, the textural properties of cheeses can be forecast through mathematical equations. Similarly the age of cheese can also be predicted if RI and/or textural properties are known.     

Health insurance status and the use of emergency and other outpatient services by adults with sickle cell disease

STUDY OBJECTIVE: To evaluate insurance status and frequency of use of emergency services in adults with sickle cell disease. DESIGN: Retrospective analysis of visits. SETTING: Emergency department and outpatient clinics of an urban university hospital. PARTICIPANTS: One hundred seventy-two subjects, who made 771 visits to the ED during 1990. RESULTS: Of the 172 subjects, 31 were covered by commercial insurance, 32 were covered by Medicare, and 109 were covered by Medicaid or were uninsured. Insurance status and frequency of use of emergency services were independent (P > .05). On discriminant analysis, Medicaid-covered and uninsured subjects were correctly classified, but commercially insured and Medicare subjects were not. Medicaid and uninsured subjects were more likely to be younger and to live closer to the hospital (P < .00005). High-frequency users of emergency services were discriminated from low-frequency users. High-frequency users were more likely to be younger, to be users of primary-care services, and to live closer to the hospital (P = .0004). CONCLUSION: Provision of primary-care services or stable insurance in the form of commercial insurance or Medicare did not decrease use of emergency services in subjects with sickle cell disease in a group of patients selected from one urban academic ED.     

Influence of curing at different relative humidities upon compound reactions and porosity in Portland cement paste

The reduction in relative humidity within drying concrete depends mainly on the depth from the exposed surface, exposure duration, temperature and environmental humidity; this limits hydration and coarsens pore structure, thus impairing durability. OPC paste, of 0.59 water/cement ratio, was cured for 2 days and then exposed to controlled relative humidity environments. After 14 and 90 days exposure, hydration of the individual compounds was measured using quantitative X-ray diffraction and thermogravimetry. Methanol adsorption was used to monitor porosity and gel formation. Even a small drop in relative humidity below 95% r.h. significantly limited cement hydration. Gel porosity increased with amount of hydration and, for a given level of hydration, decreased with drying. Curing below 80% r.h. produced a coarsened pore structure with a large-diameter porosity three times greater than that obtained with saturated curing.     

Production of alumina fibre through jute fibre substrate

Alumina fibre has been produced using jute fibre as substrate material at temperatures lower than 1600 C in a reducing atmosphere. Processed jute fibre was chemically pretreated by saturation with Al₂Cl₆ · 12H₂O, coked and then pyrolysed to obtain alumina fibre. Chemical pretreatment conditions have been determined by following weight loss measurements of the jute fibre at 0.1 to 0.6 N solutions of NaOH, KOH, NH₄OH, Na₂CO₃, K₂CO₃, HCl and acetic acid. The effect of heat treatment on the jute fibre and jute fibre + aluminium salt has been studied from 150 to 1600 C. Trace elements present (Fe₂O₃, SiO₂, K₂O, Na₂O, CaO, MgO, ZnO, MnO, V₂O₅, P₂O₅, CuO) on heat-treated products have been determined by atomic absorption spectrometry. Optical and scanning electron micrographs of representative samples showing growth mechanism are presented. The effect of copper, nickel and platinum catalysts and fluxing agents such as K₂O and Na₂O in fibre formation has also been examined. Particle size and surface area analyses of intermediate and final products have been carried out. Changes in 2 values are plotted for various products from X-ray diffraction studies. It is conceived that the porous surface of cellulosic fibrils in the jute fibre adsorbs the AlCl₃ molecules which decompose to oxide and are gradually shaped to the fibrous form during the course of thermal treatment in a reducing atmosphere and due to the high surface area.     

INVESTIGATION OF THE USE OF LASER-DOPPLER VELOCIMETRY IN TWO-PHASE BUBBLY FLOWS

Understanding the dynamic phenomena of viability loss of shear sensitive cells and bubble breakage and coalescence within airlift reactors requires knowledge of local, liquid-phase hydrodynamics. The laser-Doppler velocimeter (LDV) is a non-invasive instrument which may be used to obtain this information. Experimental procedures and software were developed to detect and measure Doppler bursts in two-phase flow in a split-cylinder airlift reactor. Off-line analysis of the data indicated a detection rate approximately one order of magnitude greater than that observed using an available commercial frequency tracker. Approximately 400 to 500 observations are needed for the ensemble mean to characterize the local mean velocity to within ±5% for a superficial gas velocity of 10.4 cm/s, the highest superficial gas velocity used in these studies. The limitations, prospects, and signal-processing options for LDV in this application are also discussed     

Synthesis and characterization of poly(keto-amines). 2. Self-polycondensation of 4-methyl-3-aminophenacyl chloride and 2-methyl-4-aminophenacyl chloride

Poly(keto-amines) such as poly(4-methyl-3-iminophenacyls) and poly(2-methyl-4-iminophenacyls) were prepared by self-polycondensation of 4-methyl-3-aminophenacyl chloride and 2-methyl-4-aminophenacyl chloride under different experimental conditions. All the polymer samples were insoluble in common organic solvents. They were characterized by elemental analysis, IR spectral studies, estimation of M?_n by non-aqueous conductometric titration and study of thermal properties by DTA. The properties of P4M3IP and P2M4IP were compared with those of poly(4-iminophenacyls).     

Grafting of methyl methacrylate onto guar gum by hydrogen peroxide initiation

Graft copolymerization of methyl methacrylate (MMA) onto guar gum (GG) in aqueous slurry has been carried out using hydrogen peroxide (H₂O₂) as initiator. The copolymers were characterized by infrared spectroscopy. The grafting parameters like percent grafting, grafting efficiency, percent add-on, and the grafting frequency were determined, and the effect of reaction time, concentration of initiator, and [GG]/[MMA] ratios on the grafting parameters have been discussed. The decrease in % add-on at increasing concentration of H₂O₂ indicated enhancement in the rate of homopolymerization of methyl methacrylate.     

Predicting elastic moduli of heterogeneous polymer compositions

A new method for predicting elastic moduli M of heterogeneous polymer compositions is proposed. It is based on a phenomenological adjustment between parallel and series models for upper and lower bound moduli M_U and M_L. Thus, where ?_H is the volume fraction of hard phase, ?_S is the volume fraction of soft phase, and n is the only adjustable parameter since the upper and lower bound moduli are given by and where M_H and M_S are the moduli of the pure hard and soft phases, respectively. Predicted values of M are in agreement with measured values in a number of systems which include polyblends and composite materials of fixed morphology. The significance of n is discussed relative to concentrations in the area of a phase transition for the polyblends or relative to phase morphology in the case of fixed morphology compositions. Interestingly, the relationship, by analogy, is in agreement with measured values of polyblend melt viscosities.     

A study on adsorption of poly(methyl methacrylate) on aluminium silicate

Effect of temperature, solvent power, and molecular weight on the adsorption of poly methyl methacrylate (PMMA) on aluminium silicate has been studied. Kinetics of adsorption have been also investigated at 30° and 45 °C. The values of rate constants at these temperatures are 1.4 · 10^?2 and 1.0 · 10^?2 min^?1 respectively. The adsorption data have been analysed according to the Langmuir and the Simha -Frisch -Eirich (SFE) isotherms. The results could be adequately explained in terms of the Langmuir isotherm.