A NOTE: POLYVALENT RADIOVACCINE AGAINST SALMONELLA

Salmonella strains exposed to lethal doses of gamma radiation are detoxified but retain their antigenic properties. Using eight Salmonella strains representative of each of the Salmonella serogroups A to G, a polyvalent radiovaccine has been developed which effectively immunizes mice to several Salmonella serotypes.     

Evaluation of constructed wetlands by wastewater purification ability and greenhouse gas emissions.

Domestic wastewater is a significant source of nitrogen and phosphorus, which cause lake eutrophication. Among the wastewater treatment technologies, constructed wetlands are a promising low-cost means of treating point and diffuse sources of domestic wastewater in rural areas. However, the sustainable operation of constructed wetland treatment systems depends upon a high rate conversion of organic and nitrogenous loading into their metabolic gaseous end products, such as N2O and CH4. In this study, we examined and compared the performance of three typical types of constructed wetlands: Free Water Surface (FWS), Subsurface Flow (SF) and Vertical Flow (VF) wetlands. Pollutant removal efficiency and N2O and CH4 emissions were assessed as measures of performance. We found that the pollutant removal rates and gas emissions measured in the wetlands exhibited clear seasonal changes, and these changes were closely associated with plant growth. VF wetlands exhibited stable removal of organic pollutants and NH3-N throughout the experiment regardless of season and showed great potential for CH4 adsorption. SF wetlands showed preferable T-N removal performance and a lower risk of greenhouse gas emissions than FWS wetlands. Soil oxidation reduction potential (ORP) analysis revealed that water flow structure and plant growth influenced constructed wetland oxygen transfer, and these variations resulted in seasonal changes of ORP distribution inside wetlands that were accompanied by fluctuations in pollutant removal and greenhouse gas emissions.     

Characterization of Tomato Pulp Stickiness during Spray Drying using a Contact Probe Method

A contact probe test was developed to characterize the surface stickiness of a tomato pulp droplet at various moisture contents and temperatures. To provide tomato pulp samples with different moisture contents, tomato powder produced by a laboratory spray dryer was wetted to seven different moisture levels. The instantaneous tensile force curve was recorded during the probe withdrawal from which the maximum tensile force and other useful information were obtained and cross-examined against images of bonding, debonding, and failure of the material. Generally, at higher moisture contents tomato pulp exhibited cohesive failure followed by semi-adhesive failure, but when moisture content decreased to a certain level, a peak tensile pressure was observed and the failure was adhesive. In addition, higher temperatures shifted the points of adhesive failure toward lower moisture content.     

Isolation and Partial Characterization of Phytic Acid-Rich Particles from Great Northern Beans (Phaseolus vulgaris L.)

Phytic acid-rich particles were isolated from a combined density fraction (CDF) of Great Northern beans. CDF contained more than 80% of the total phytic acid, and 70% of the total crude protein and substantial amounts of certain minerals. CDF had phytic acid in both water soluble and water insoluble forms. An isolate containing phytic acid-rich particles was prepared from CDF using a Tris-base solution. The phytic acid-rich isolate contained 26.6% phytic acid, 34.3% protein, 30.0% total carbohydrates, 0.6% calcium, 2.1% magnesium, and 0.3% potassium. Chemical analysis and fractionation of CDF indicated that the water insoluble form of phytic acid in Great Northern beans was present as a salt of calcium-magnesium-potassium in association with proteins.     

Concurrent Cholesky factorization of positive definite banded Hermitian-matrices

First the Cholesky factorization is extended to cover uniformly partitioned banded positive definite matrices of rank n which may be real symmetric or Hermitian. Then two stratagems are given for the use of the algorithm in concurrent machines where the number of processing elements is less than required to factor the matrix in as few serial steps as possible, and where uniformly high efficiency is expected from all processing elements. Expressions are given for the efficiency factor e appearing in the speed-up expression g = eN, and these are specialized for the N node hypercube machine as a function of partition size s, the number N of processing elements of the hypercube machine, and the cost μ of interelement transmission relative to computation. It is shown that efficiency factor e is inversely proportional to μ/s, and that e is almost independent of N when N is large and μ/s = 0. The task is completed in n/s serial steps with no limit on n. The half bandwidth b of the matrix is 2Ns.     

Estrogenic personal care products in a greywater reuse system.

The occurrence and fate of parabens in a greywater system was assessed. The potential for removal of residual paraben concentrations in effluent greywater with chlorine dioxide was also investigated. The influent to the greywater plant was characterised by considerable variation, with concentrations from below the detection limit to 40 microg/L and the five commonly used parabens in consumer products were frequently detected. After the biological treatment only two paraben were detected with concentration from 65-120 ng/L. Chlorine dioxide treatment of the biologically treated effluent with dosages down to 0.75 mg/L resulted in more than 97% reduction of all parabens. Formation of the by-product chloroform was insignificant from the chlorine dioxide treatment.