ALBERT

Notes: Laboratory flow visualization experiments, using glass beads as the porous medium, were conducted to study air sparging, an innovative technology for subsurface contaminant remediation. The purpose of these experiments was to observe how air flows through saturated porous media and to obtain a basic understanding of air plume formation and medium heterogeneity effects. The experiments indicate that air flow occurring in discrete, stable channels is the most probable flow behavior in medium to fine grained water saturated porous media and that medium heterogeneity plays an important role in the development of air channels. Several simulated scales of heterogeneities, from pore to field, have been studied. The results suggest that air channel formation is sensitive to the various scales of heterogeneities. Site-specific hydrogeologic settings have to be carefully reviewed before air sparging is applied to remediate sites contaminated by volatile organic compounds.

Notes: Ground water samples for a hydrochemical investigation were collected from 92 observation wells completed in a shallow, unconfined aquifer in southeastern North Dakota. The samples showed predominantly an increase in HCO3- (positive bias) and both a pH decrease (positive bias) and a pH increase (negative bias) from field to lab. Positive pH bias generally was associated with ground water characterized by dissolved-solids concentrations less than 400 mg/L. Negative pH bias generally was associated with ground water characterized by dissolvedsolids concentrations greater than 400 mg/L.Observed HCO3- bias from field to lab slightly distorted ion balance distribution. Excess anions greater than 2 percent generally corresponded to increased HCO3- from field to lab.Observed HCO3- and pH bias significantly distorted the distribution of calcite saturation indices. Samples with dissolved-solids concentrations less than 400 mg/L that generally showed a positive pH bias had a mean change in calcite saturation index of -0.214 (toward undersaturation). Samples with dissolved-solids concentrations greater than 400 mg/L that generally showed a negative pH bias had a mean change in calcite saturation of +0.132 (toward over saturation).Calcite saturation indices were much more sensitive to observed pH bias than to observed HCO3- bias. Linear regression analysis indicates % percent of the variability in calcite saturation index change from field to lab is attributed to change in pH from field to lab. Field pH should be used to compute calcite saturation index.

Notes: Lincolns municipal wellfield consists of 44 wells developed in an alluvial aquifer adjacent to the Platte River near Ashland, Nebraska Induced recharge from the river is the primary source of water for the wellfield. Wafer samples were collected on a periodic basis from the Platte River arid two transects of monitoring wells. These samples were analyzed for the herbicide atrazine, which was used as a tracer of induced recharge in this stream-aquifer system. Atrazine concentrations in the river and aquifer were much less than 1.0 ppb during late fall and winter, but increased to as high as 18.9 ppb during spring and summer, associated with runoff from upgradient agricultural lands. There was approximately a 21-day lag time from the first detection of increasing atrazine concentration in the river to the first detection in monitoring wells immediately adjacent to the river. This lag time was relatively constant throughout the year and from one year to the next, even with major fluctuations of river stage and wellfield production. This consistency of lag time indicated that the travel times from the river to the first set of monitoring wells immediately adjacent to the river were fairly constant.Paths of preferential flow were identified in the aquifer at a depth of 25 to 35 feet below land surface. This aquifer zone appeared to play a significant role in movement of water from beneath the river into the wellfield.Aquifer dispersivity was calculated using a method described by Hoehn and Santschi (1987). Macrodispersivity (AL) was shown to increase linearly over the scale of the wellfield. Calculated values of AL were within limits of other reported values for this type of aquifer material and agreed well with values reported by Hoehn and Santschi (1987); These findings will be extremely beneficial for planning and management of the municipal wellfield.

Notes: A regional survey of Danish ground water demonstrated the presence of adsorbable organic halogens (AOX) in almost all of 142 wells (99 percent). Generally, the presence of AOX was not related to point or non-point source contamination with halogenated organics. However, the AOX concentrations varied with the geology of the aquifers. Extractable organic halogens (EOX) and volatile organic halogens (VOX) were far less prevalent (detected in 4 percent of sampled wells) and the detection could, in most cases, be explained by contamination or chlorination of the wells. The VOX concentrations corresponded to the concentrations of identified, volatile contaminants. The study demonstrates the presence of a natural background level of AOX in the investigated aquifers. This must be considered in the interpretation of AOX results as an indicator of ground water contamination with haloorganics. Similar background levels of EOX or VOX were not delected.

Notes: When the purpose of aquifer testing is to yield data for modeling aqueous mass transport, pumping tests and gradient measurement can only partially satisfy characterization requirements. Effective porosity, ground water flow velocity, and the vertical distribution of hydraulic conductivity within the aquifer are left as unknowns. Single well tracer methods, when added to the testing program, can be used to estimate these parameters. A drift, and pumpback test yields porosity and velocity, and point-dilution testing yields depth-discrete hydraulic information, A single emplacement of tracer into a test well is sufficient to conduct both tests. The tracer tests are facilitated by a simple method for injecting and evenly distributing the tracer solution into a wellbore, and by new ion-selective electrode instrumentation, specifically designed for submersible service, for monitoring the concentration of tracers such as bromide.

Notes: Pumping test data for surficial aquifers are commonly analyzed under the assumption that the base of the aquifer corresponds to the bottom of the test wells (i.e., the aquifer is truncated). This practice can lead to inaccurate hydraulic conductivity estimates, resulting from the use of low saturated thickness values with transmissivity estimates, and not accounting for the effects of partially penetrating wells. Theoretical time-drawdown data were generated at an observation well in a hypothetical unconfined aquifer for various values of saturated thickness and were analyzed by standard curve-matching techniques. The base of the aquifer was assumed to be the bottom of the pumping and observation wells. The overestimation of horizontal hydraulic conductivity was found to be directly proportional to the error in assumed saturated thickness, and to the (actual) ratio of vertical to horizontal hydraulic conductivity (Kv/Kh). Inaccurately high estimates of hydraulic conductivity obtained by aquifer truncation can lead to overestimates of ground water velocity and contaminant plume spreading, narrow capture zone configuration estimates, and overestimates of available ground water resources.

Notes: Positive-displacement piston pumps that minimize sample agitation have no apparent advantage over centrifugal submersible pumps when used to collect ground water samples for analysis of low concentrations of purge-able organic compounds. Analytical uncertainties inherent in laboratory environments appear to influence analytical results of low-concentration purgeable organic compound samples more than either pump type or sampling team. Centrifugal submersible pumps are at least equally efficient as positive-displacement piston pumps in the recovery of carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, and chloroform after sampling and analytical influences are made constant.

Notes: Two borehole geophysical methods—electromagnetic induction and natural gamma radiation logs—were used to vertically delineate landfill leachate plumes in a glacial aquifer. Geophysical logs of monitoring wells near two land-fills in a glacial aquifer in west-central Vermont show that borehole geophysical methods can aid in interpretation of geologic logs and placement of monitoring well screens to sample landfill leachate plumes.Zones of high electrical conductance were delineated from the electromagnetic log in wells near two landfills. Some of these zones were found to correlate with silt and clay units on the basis of drilling and gamma logs. Monitoring wells were screened specifically in zones of high electrical conductivity that did not correlate to a silt or clay unit. Zones of high electrical conductivity that did not correlate to a silt or clay unit were caused by the presence of ground water with a high specific conductance, generally from 1000 to 2370 μS/cm (microsiemens per centimeter at 25 degrees Celsius). Ambient ground water in the study area has a specific conductance of approximately 200 to 400 μS/cm. Landfill leachate plumes were found to be approximately 5 to 20 feet thick and to be near the water table surface.

Notes: The diffusion of 2,2,4-trimethylpentane (TMP) and 2,2,5-trimethylhexane (TMH) vapors put of residually contaminated sandy soil from the U.S. Environmental Protection Agency (EPA) field research site at Traverse City, Michigan, was measured and modeled. The headspace of an intact core sleeve sample was swept with nitrogen gas to simulate the diffusive release of hydrocarbon vapors from residual aviation gasoline in and immediately above the capillary fringe to a soil-venting air flow in the unsaturated zone. The resulting steady-state profile was modeled using existing diffusivity and air porosity estimates in a balance of diffusive flux and a first order source term. The source strength, which was calibrated with the observed flux of 2,2,4-TMP leaving the sleeve, varied with the residual gasoline remaining in the core, but was independent of the headspace sweep flow rate. This finding suggested that lower soil-venting air flow rates were in principle as effective as higher air flow rates in venting LNAPL vapors from contaminated soils. The saturated vapor concentration ratio of 2,2,4-TMP to 2,2,5-TMH decreased from 6.6 to 3.5 over the duration of the experiments in an expression of distillation effects. The vertical profile model was tested against sample port data in four separate experiments for both species, yielding mean errors ranging from 0 to—24 percent in magnitude.

Notes: Samples from 94 Swedish blood donors were analysed for HLA-DQA1 and -DQB1 alleles by the PCR-SSO technique used in the XIth Histocompatibility Workshop. Seven DQA1 and 12 DQB1 alleles were identified and a total of 17 haplotype combinations were found deduced from the most probable allele combinations. Frequencies calculated from these haplotypes were compared to those calculated from the phenotypes according to Mattiuz et al. (1970). There was no significant difference in the frequencies of the 17 haplotype combinations deduced. Eight haplotype combinations had exactly the same frequencies and four had approximately the same frequencies independent of the calculation method used. The DQA1*0301-DQB 1*0302, DQA1*0501-DQB1*0201, DQA1* 0101-DQB1* 0501, and DQA1*0102-DQB1*0602 were the most frequent haplotypes with frequencies over 0.130.

Notes: We have studied the genotypic, haplotypic, and allelic distribution of germline Restriction Fragment Length Polymorphism (RFLP) of T-cell receptor (Tcr) α, γ, and δ loci in 75 insulin-dependent diabetes mellitus (IDDM) patients and 84 healthy blood donors as control population. The restriction endonuclease PvuII produces three allelic fragments of Tcr C-γ (TcrCG) gene segment of 16,13, and 11.3 Kb respectively. Our observations revealed that PvuII/TcrCG RFLP allelic distributions were not significantly different in the IDDM and the control group. However, 85% of IDDM patients carried HLA DR3 and/or DR4 haplotypes, and when comparing these patients with a second group of HLA DR3+ and/or DR4+ healthy individuals, the 11Kb/PvuII fragment of TcrCG gene was found to be associated with IDDM patients (χ= 11.4, P= 0.003). 54.9% of IDDM patients carried at least one 11.3 Kb allele vs. 21% in controls (χ= 10.77, P = 0.004). No significant association was found between RFLP in Tcr, Cα, Cδ, Vγ9 loci and IDDM.

Notes: The outcome of subcutaneous infection with L. major NIH 173 was evaluated in a series of recombinant inbred and congenic strains, as well as F2 progeny generated from a genetic linkage testing stock carrying the visible markers Ra, Os, and Pt. The disease parameters monitored were the incidence of open or necrotic lesions and footpad depths of infected feet, and the incidence and number of amastigotes in livers following infection. Regions of mouse chromosomes 2, 4, 7, 8, 12 and 15 were excluded from linkage to a gene (Scl-1)involved in the susceptibility of inbred strains of mice to cutaneous infection with L. major NIH 173 by F2 and congenic strain analyses. Strain distribution patterns generated for Scl-1 in the CXB and CXS recombinant inbred strains suggested linkage to the distal end of mouse Chromosome 11.

Notes: Natural killer cell (NK) activity is regulated by both the H-2 and non-H-2 genes. Using bilineal congenic HW26C and HW13 mice which differ from the background strain C57BL/6By (B6) in a region of chromosome 4, we investigated the role played by a gene/genes in a segment of chromosome 4 of BALB/cBy on NK cell activity. Percoll separated low density spleen cells from young HW26C and HW13 mice showed a 3.5 fold higher NK activity than the B6. We also observed that the increase in NK activity of HW26C was not due to an increase in the number of NK cells. Using five other bilineal congenics containing different regions of chromosome 4 of BALB/cBy, we observed that the putative gene(s) regulating NK activity may be located between b and IFN-α/β genes of chromosome 4. The level of NK activity of (B6xHW26C)F1 ranked between the HW26C and B6 suggesting that the gene product described is inherited in an incompletely dominant fashion.

Notes: We describe a new, non-radioactive microtitre plate assay for the analysis of genetic variations at the DNA level. The new method combines hybridization of oligonucleotides with PCR amplified DNA in liquid phase with detection in solid phase using an elisa-reader. Genomic DNA is labelled with digoxigenin during PCR using a nucleotide mix containing DIG-11-2′-deoxy-uridine-5′-triphosphate (DIG-11-dUTP) DIG labelled, amplified genomic DNA is hybridized in solution with an oligon de which is labelled with one biotin at its 3′-end, using biotin-16,2′,3′-dideoxy ine-5′-triphosphate (BIO-16-ddUTP) and DNA deoxynucleotidylexo-transferase (TdT). The hybridized complex is immobilized in a streptavidin (SA) coated microtitre plate via the biotin and detection of digoxigenin is performed using anti-digoxigenin horseradish peroxidase, fab fragments (anti-DIG-POD), and the colorimetric substrate 2,2′-Azino-di-(3-ethylbenzthiazolinsulfonat[6]) (ABTS®). The resulting absorbtion of the assay is analysed in a microtitre plate reader. This method results in highly specific and sensitive hybridization signals and with the 15 oligonucleotides chosen, allows the typing of DR1-DR10.

Notes: In this note is recommended a unified nomenclature for allotypes and variants of human complement factor B, which was approved by the Nomenclature Committee of the International Union of Immunological Societies (IUIS).

Notes: By quantitation of elutable immunoglobulin G in a recently described elisa, the number of HLA class I and II molecules on B-cell lines was determined using monomorphic monoclonal antibodies. An average number of 183 000 binding sites per cell for HLA class I-, 99000 for HLA-DR-, 63000 for DQ- and 42000 for DP-specific monoclonal antibodies were determined. The small amount of HLA class II molecules can in part explain the difficulties observed in HLA class II typing or in detection of class II antibodies using the lymphocytotoxicity text.

Notes: The second exon of the DRB1 gene encoding for the first domain of the HLA-DR β-chain was sequenced in 16 patients (10 DR4/DR1 positive, 6 DR4/DR1 negative) with seropositive rheumatoid arthritis (RA). We could confirm the strong association of susceptibility to RA with functionally equivalent conformations on otherwise distinct MHC molecules. At least one HLA-DR allele in all of the analysed DR4 or DR1 positive patients showed such an epitope with a minimal variability limited to residue 71.However, in HLA-DR4 and -DR1 negative patients such a similar epitope could not be detected.

Notes: In order to produce mAbs directed specifically against HLA-DR10 molecule, transfected mouse L cells, expressing the DRB 1*1001 allele, were used to immunize C3H mice over a period of 4 weeks. Two mAbs, 2C12 and 4B6, derived from this fusion were found to recognize, with different affinity, polymorphic epitopes of DR10 that are shared with DR1, 3, 7, and 9. These mAbs were screened on a large panel of homozygous B lymphoblastoid cell lines using microlymphocytotoxicity and the results were confirmed by flow cytometry. The reactive pattern of 2C12 and 4B6 was compared to that of MP10 human mAb also recognizing the DR10 specificity in addition to DR1, 2 and 9.Based on serologic specificity and cellular absorption experiments, we conclude that the epitopes the murine and human mAbs respectively recognize on the DR10 molecule, are probably different.

Notes: Deficiency of complement component C4 is considered playing a role in the genetic predisposition for systemic lupus erythematosus (SLE). The purpose of this study was to characterize the genomic alterations of the C4 and CYP21 genes in 40 caucasoid patients with SLE by C4 allotyping and by RFLP analysis. Nineteen patients (47.5%) carried C4A null alleles and eight patients (20.0%) C4B null alleles. SLE patients had more frequent C4A null alleles (47.5%) than healthy individuals (20%) (X2= 10.75; P 〈 0.005). The commonest molecular alteration in the patients with C4A null alleles was a large gene deletion affecting both C4A and CYP21A genes. However, among the patients with C4A null alleles, 16.7% persons had no detectable C4A deletion. The non-expression of C4A gene might be due to defects at various levels of gene expression (i.e. transcription and translation).Among the patients with C4B null alleles, 62.5% persons had no detectable gene lesion, whereas 37.5% showed a C4B deletion including both C4B/CYP21A or C4B/CYP21B genes.Duplication of the C4B gene was not rare in SLE patients, as we found 15.0% of the patients with a heterozygous C4B/CY21A gene duplication. The patients typed as having C4B gene homoduplication (B1,1) demonstrated two long C4B loci, whereas heteroduplication (B1,2) displayed two short loci, therefore the type of C4B gene duplication may be related to the gene length.In conclusion, C4 deficiencies observed in 26 of the 40 SLE patients studied were very heterogeneous. In every case, the gene alteration affected both C4 and CYP21 genes.

Notes: When routine gas-monitoring operations were carried out at Breeze Hill School, Oldham, more than 20% methane (by volume) was recorded beneath the floor of the sports block. Following consultations with interested parties the school was evacuated.The results of subsequent investigations suggested that biodegradable material beneath and adjacent to the school was the source of the gas. The geometry of the landfilled material and the site geology were such that there was a potential for migration of the resulting landfill gas.Methane is a flammable gas. An explosive risk exists whenever a methane/air mixture is present comprising 5–15% methane (by volume). Higher concentrations are no less hazardous since dilution of the concentrated gas in air will result in flammable or explosive mixtures.This paper details the nature of the investigations and the gas control measures carried out at Breeze Hill School.

Notes: Sludge arisings in the Hong Kong Territories are predicted to increase from the current level of 44 300 tDS/annum to 314000 tDS/annum. This has led to a need to examine the treatment and disposal facilities required for the future. Disposal facilities were found to be restricted, with virtually no suitable land for a liquid disposal route and a sea route limited to the present quantities. Only landfill remained as the major disposal outlet, but this is also limited by the moisture absorbence capacity of the emplaced material and limiting metal concentrations.In order to match the sludge production to the disposal outlet capacity, a series of process options was considered. Transportation studies using pumping, road and sea networks were undertaken and the environmental impact assessment of introducing thermal technologies was reviewed. Finally the various options were evaluated using a modified version of the Water Research Centre's WISDOM model.

Notes: The very low level of recharge to the chalk of the South Downs, which provide Brighton with its water supply, has meant that the groundwater levels are very low. Despite this, no restrictions have been necessary since February 1991. This is perhaps due to the instigation of public information campaigns, together with media coverage of the drought, as well as a successful programme of leakage control. This paper looks at how the growth of public water supply has been accommodated operationally while ensuring that groundwater quality is maintained. Options for the future expansion of supply, and their cost-effectiveness, are also considered.

Notes: The development of the awareness of Legionnaires disease and Pontiac fever is outlined, and the causative organisms are considered together with their environmental sources. Modes of transmission of the infections are discussed and the multiplication of the organisms within, and dangers associated with, water cooling towers and hot and cold water systems are investigated. Consideration is also given to the resistances of the Legionellae to temperature and chemical disinfectants. The elimination of Legionellae from, or their control within, waste systems and cooling towers are pursued and some definite suggestions made.

Notes: Agricultural water demand is weather and climate driven. Irrigated crop production which makes the largest agricultural demands is highly seasonal, water only being required in a few summer months. A ‘droughtiness’factor which is based on crop type and potential soil moisture deficit indicates large differences in the amount and timing of water demand for different crops. Soils with low water retention capacity are shown to be marginal for the potato crop unless irrigation is available in these areas. Economic data are presented which indicate that potato production realizes a considerable benefit from investment in irrigation, but this leads to inertia in the relocation of agricultural production centres in dry years. It is concluded that investment in on-farm winter water storage for irrigation should be a priority investment in eastern England.

Notes: The River Slea through Sleaford is fed by groundwater emanating from the Lincolnshire Limestone. In recent years, the springs have dried up periodically, causing failure of river flow through the town. The Slea is a main feature of the town and, when flowing, a valuable visual amenity. Conversely, when it is not flowing, progressive water quality deterioration in ponded sections reduces the river corridor to an eyesore. The paper describes investigations into the cause of the problem and how to overcome it.

Notes: This paper describes the programme of work being undertaken in a number of European organizations supported by the European Commission, which is designed to achieve the Single European Market. In particular, an explanation is provided on the organization of European standards, concentrating on the work affecting the water cycle. Reference is made to the public procurement, utilities and construction products Directives, and the need for accreditation using certification and testing. Also, an explanation is provided of the committee structure being established to facilitate mutual recognition of certification and test procedures to satisfy both regulatory and voluntary requirements of products and services.

Notes: The paper describes and discusses the effect on the local benthic community of the discharge of a dense, saline, effluent into a nearshore area of the North Sea. The monitoring programme continued through the twenty-year period from 1970 until 1989 and includes effectively five years pre-discharge data. Samples were taken from fixed stations with a grab sampler and the invertebrate fauna were identified, wherever possible, to species. In addition, the particle size distribution of the sediment in each sample was determined. The discharge has had a clear effect on the benthic community.This extensive dataset, with its clear gradient of effect, also offers the opportunity of comparing the effectiveness of species and family level identification when studying the effect of disturbance. In this case the impacted area was as readily identifiable from the family as the species level data.

Notes: Water levels in tidal rivers are subject to the influence of both fluvial and tidal factors. The interaction between these factors is rendered more complex in regions affected by typhoons, which typically result in the combined occurrence of heavy rainfall and high sea levels.Previous studies have outlined an analytical approach for calculating design water levels based on dividing the fluvial and tidal series into a typhoon and a non-typhoon component. This paper illustrates the steps involved in the analytical approach and describes its application to drainage basins in Hong Kong.The approach provides a practical means for calculating design water levels, and is recommended for final design purposes. The results of using the full analysis may be approximated by using a sub-set of analytical results, and should prove satisfactory for the purposes of outline design.

Notes: Customers, the public generally, the water industry, its regulators and the government are aware that water can be a scarce and costly product. Resource planning and development must increasingly be viewed as a combined package of water efficiency in (a) use, (b) metering and tariff policy, (c) leakage reduction, and (d) physical schemes.Droughts, fears over possible climate change, concerns about resources and the environment, a greater awareness of the role and costs of the water industry and statements by the Department of the Environment, the Office of Water Services, and the National Rivers Authority have added weight to this sensible shift in emphasis.However, society needs reliable water supplies and cannot completely rely upon the uncertain impact that demand side-measures may bring about – nor, even where achieved and cost-effective, on the important savings in losses. New resource schemes can take many years to implement. Therefore, in order to ensure adequate and reliable supplies, plans for new schemes must be brought to a state of readiness, and, in many cases, implemented.

Notes: Hydraulic Ram Pumps – a Guide to Ram Pum pump Water Supply Systems, by T. D. Jeffery, T. H. Thomas, A. V. Smith, P. B. Glover, and P. D. Fountain. Published by Intermediate Technology Publications, 103–105 Southampton Row, London, WC1B 4HHThe Entec Directory of Environmental Technology (European Edition). Published by Earthscan Publications Limited, 120 Pentonville Road, London N1 9JNHydraulic Structures, by P. Novak, A. I B. Moffat, C. Nalluri and R. Narayanan. Published by Unwin Hyman Ltd and distributed by Chapman & Hall, North Way, Andover, Hampshire, SP10 5BEHydraulics in Civil and Environmental Engineering (2nd edn.) by A. Chadwick and J. Morfett. Published by E. & F. N. Spon, an imprint of Chapman & Hall, 2–6 Boundary Row, London SE1 8HN

Notes: The paper reviews the regulation of water companies in England and Wales since 1989 by reference to the historical regulation of utilities in these countries. It considers how comparative competition, service standards and charging arrangements are developing. Particular mention is made of the debates over rates of return and household metering. The conclusion is that regulation, to be effective and appropriate, must be capable of evolution.

Notes: The Water Resources Act 1991 requires the National Rivers Authority to exercise a general supervision over all matters relating to flood defence. There is need for information in order to manage flood defence – not only as part of the overall management of the catchment but, at a more detailed level, to plan and monitor capital and maintenance programmes.The information requirements of the National Rivers Authority can be satisfied either by witnessing historic flood events, an approach disadvantaged by the infrequency of flood events, or by modelling the system, i.e. the rivers, coasts and flood plain. Once models are calibrated by specific flood events they can be used to predict the outcome of other events and to assess the response required to alleviate potential flooding. The different needs of the Authority can be satisfied by different modelling techniques using different levels of accuracy. Models can be used to analyse river and coastal systems to assess performance and target resources for maintenance and improvement.The management of flood defences by specifying and monitoring their performance is considered, and a recent trial in reach specification based on modelling techniques is described.

Notes: In the consolidated formations which form most of the major aquifers in the UK, many monitoring boreholes are left unlined (open) for their effective length. They therefore provide pathways for groundwater to flow from one part of the aquifer to another.A borehole was core-drilled through Triassic sandstones into Permian mudstones at a site in North Yorkshire. Pore water was extracted from the core and compared with conventional depth samples and with samples taken from intervals isolated using packer systems: (a) during drilling, (b) about one month after drilling, and (c) two years after drilling.The study revealed that natural flow down the borehole led to rapid changes in the quality of water in some parts of the formation.The implication is that open boreholes can act as conduits to allow flow to take place from one part of the aquifer to another. They are therefore not reliable as sampling points, and may actually accelerate the vertical spread of pollutants. However, this last effect should not be over-stated; in this study, the flow down the borehole was equivalent to the natural flow through only a relatively small area of land.

Notes: The models which are used to estimate equilibrium and evolving changes in climate, due to increases in greenhouse gas concentrations, are described. Results from a 75-year experiment with carbon dioxide increasing at 1%/annum using a coupled model of the atmosphere, land and deep ocean, are presented and compared with those from equilibrium experiments. Rainfall over the UK increases over the year as a whole, with the largest changes in winter; however, in summer it decreases except in the north. Soil moisture decreases except in winter. Results from an equilibrium experiment show that rainfall tends to be more intense but less frequent with a doubled atomospheric concentration of CO2. A scenario of climate change over western Europe is included, based on these and other experiments.

Notes: Regulations governing the quality of drinking water within the European Community must be based on Directive 80/778/EC, although Member States may impose tighter or additional limits if they so wish. The Directive is substantially derived from standards set by the World Health Organisation (WHO) in 1970. Revised ‘Guidelines Values’for water contaminants were issued by WHO in 1984, and a further revision will be published in 1993. Modest changes in the guidelines set by WHO for microbiological parameters since 1970 have been accompanied by a large increase in the number of limits set for chemical parameters. This is particularly marked for organic compounds including pesticides and disinfection byproducts. The new WHO guidelines will inevitably have an impact on water supplies in the UK, but the timescale for a significant change in the outmoded EC Directive is uncertain.

Notes: A pilot plant which has been used to examine the suitability of a number of treatment options for upgrading North West Water's water-treatment plant at Huntingdon, Chester, is described. Processes tested include biological pretreatment using a fluidized sand bed to remove manganese and ammonia, chemical coagulation, chemical oxidation using chlorine, ozone and potassium permanganate, and both primary and secondary filtration with sand and granular activated carbon. The reduction of trihalomethanes and pesticides was also investigated.

Notes: The particular difficulties of sewage treatment in a Gulf State of the Middle East are highlighted. Ambient temperatures may at times exceed 50°C, and sand and dust can be a problem. A description is given of the sewerage and sewage-treatment facilities at Al Ain in the United Arab Emirates, together with analytical data and flow records from commissioning until 1991. Attention is drawn to the problem of rapid anaerobic decomposition of sewage, consequent septicity, emission of foul odours, and hazardous hydrogen sulphide. There is a need for better control of this nuisance. Comment is made on high temperatures, and also on loss by latent heat of evaporation. The inability to reconcile sludge production with that indicated by empirical data, or predicted by sludge production formulae, is discussed.

Notes: During recent years it has become clear that, particularly to protect the quality of sea waters, nitrogen and phosphorus discharges have to be substantially reduced. Nitrogen reduction can take place by conventional biological treatment. However, the problem can be partly, or perhaps completely, resolved by treating the returned liquors resulting from sludge dewatering. These normally create a substantial load on sewagetreatment works; in fact the nitrogen in the returned liquors can contribute 15–25% of the total nitrogen load entering the works. It therefore seems appropriate, particularly with a view to future nitrogenreduction requirements, to treat the returned liquors before they are returned to the works’inlet. Since 1987, Watergroup has been working on these problems, and the company now has full-scale plants at Frederikshavn, Denmark (population equivalent 130 000) and Eslöv, Sweden (population equivalent 250 000). Normally this treatment can be carried out at a considerably lower cost, per kg nitrogen removed, than when applying traditional methods. An additional advantage is that the method makes it possible to reuse the nitrogen content of the returned liquor, e.g. in the form of ammonium sulphate which is an excellent fertilizer.

Notes: This paper compares the land-based disposal of municipal and hazardous waste in Europe and North America, and the various disposal options are examined for each type of waste. It is concluded that landfill is still the most widely practised disposal method for most wastes in both continents. Other methods include composting, land farming, trenching/spraying, and deep underground disposal. More stringent controls on waste disposal are being introduced and a trend to seek greater uniformity of practice and standards is developing. However, local conditions, such as the nature of the wastes and the availability and nature of disposal sites, continue to work against this trend. There is no single method which is suitable for all wastes and for all conditions. The best environmental option for waste management will vary from place to place and waste to waste, therefore an imposed uniformity of practice is not in the best environmental interest.

Notes: Following an initial exploratory survey in 1989, a detailed survey was carried out in 1990–91, the results of which indicated that a significant number of sheep dippers in the River Tweed catchment were at risk of polluting adjacent watercourses. Those dippers identified as medium to high risk of causing pollution were re-inspected in 1992 as a follow-up to the previous survey and, although in many cases dipping practices had greatly improved, a number were still at risk – emphasizing the importance of continued monitoring.To complement the survey, environmental samples were taken and, in most of the catchments, the dip-active ingredients diazinon and propetamphos were found, confirming that the leaching of dip into a watercourse was occurring over a wide area throughout the Tweed catchment. The analysis of the environmental samples taken during the main dipping period each year of the survey showed that, in general, there was a significant decrease in diazinon and propetamphos in 1991 and 1992, compared to previous years.

Notes: Traditionally, sewage-works design in Hungary has been based on rigid national standards with little consideration being given to the requirements of individual situations. This has resulted in plants that performed poorly and were expensive to construct and operate.The paper describes measures to improve the environment by upgrading Miskolc sewage-treatment works, and the conflict between the cost of those facilities, and the ability to pay against a background of changing economic conditions.

Notes: Whilst droughts, by their nature, are not frequently occurring events, it is essential, for prudent management of water-resources systems, to have analytical tools available for the effective management of the risks to water supplies when such events do occur.Within North West Water Limited, modelling techniques have been developed and applied over a number of years, which allow water-supply managers to be provided with information concerning risks to supply within the Company's water-resources systems.The paper describes how these modelling techniques have been integrated within a decision support system for drought management. Two different approaches have been used. Firstly, enhancement by the implementation of a user-friendly interface and, secondly, the development of a knowledge-based system. The problems and benefits of each approach are discussed.

Notes: The paper describes how financial and economic aspects can be analysed and quantified in environmental assessment, and how this can be related to the losses or gains in any given project. Projects which require environmental assessment often have the image of being harmful to the environment - as is the case of new roads, railways or developments which either take land out of agriculture or attract an environmentally damaging image. Many projects involve resources which are not traded and which are not always valued in financial or economic terms. Nonetheless, they are capable of being valued in this way, and their evaluation leads to greater understanding in decision-making. The study, undertaken to assess the costs and benefits of drainage for the middle and south level barrier banks on the Ouse Washes, demonstrates how (a) financial and economic analysis of the cost, and (b) the gains of a project, can guide the allocation of public resources to the benefit of the environment.

Notes: Basic questions which must be answered before standards for protecting the health of recreational users of water can be developed are considered. These questions are then used to assess the ways in which such standards and guidelines have been developed in North America and Europe. Only the North American guidelines have used epidemiological investigations to define risks to health, and other standards are apparently arbitrary. All the standards considered are directed primarily at bathing, although other water sports may involve greater or lesser degrees of contact with water and hence different risks. The statistical difficulties in defining both the central levels of counts of faecal indicator bacteria and their variability are discussed, because these affect the way in which standards are drafted and implemented. The point is made that only longterm improvements in marine disposal schemes can improve microbiological conditions and reduce risks to health, and that the main benefit of standards is to point out where such improvements are needed.

Notes: The paper reviews various options adopted in the UK for engineered protection measures aimed at preventing pollution to the environs of landfill sites. The advantages and limitations of both natural and synthetic lining materials are discussed, recognizing the constraints posed by the geometry and geology of prospective landfill sites. Particular attention is given to the Environmental Safety Centre experience with techniques designed to minimize both leachate and gaseous emissions, and hence prevent pollution of ground and surface waters, and reduce hazards to nearby property. Options for operational practices and restoration procedures are discussed in relation to the control of degradation processes and polluting potential. Included in these options are design and operation of leachate and gas collection/treatment systems, phasing of landfilling operations, and progressive restoration of sites. Monitoring requirements are emphasized as a vital measure of the success or failure of site designs and operational practices in ensuring that appropriate environmental protection is achieved and maintained.

Notes: The 1991 EC nitrate Directive has significant implications for agricultural and pollution prevention enforcement agencies throughout the European Community. Contrasting physical backgrounds, water supply sources and leaching rates, together with pre-existing nationally-based pollution control policies, means that implementing the Directive will cause different problems for member states. This paper examines the contrasting physical and legislative backgrounds in Ireland and the UK and looks at some of the problems in implementing EC policy.

Notes: Anglian Water has adopted a positive approach to conservation. This forms an integral part of the Company's environmental policy which includes a commitment to full compliance with the Code of Practice on Conservation, Access and Recreation and acknowledges the Company's statutory responsibilities towards conservation.The Company is actively incorporating conservation considerations into routine environmental assessment of a growing capital programme. The implementation of nature conservation and landscaping initiatives is making an important contribution to the wildlife and visual amenity of the Company's sites. Management plans and nature reserve agreements have been prepared for operational sites including the 10% of the Company's land which has been designated by English Nature as of Site of Special Scientific Interest status. Buildings and objects of cultural heritage interest are being restored and displayed, and the Company supports archaeological investigations around the Anglian region.Anglian is promoting awareness of conservation issues, and of its work, through support for environmental projects within the community. Regular dialogue with conservation organizations forms an important component of the Company's conservation work.

Notes: Integrated fieldwork and modelling has been undertaken to assess the vulnerability of riverside wells to pollution when river water is contaminated. Results highlight the importance of streambed sediments as a barrier to groundwater pollution by river water. The bed of the River Thames is lined with brown and grey organic-rich silts of low hydraulic conductivity (about 0.002 m/d). A 3-D model for solute transport in stream-aquifer systems was developed and applied to two riverside sites in the middle Thames valley. Model results indicate that well-water quality would only breach EC limits if the river was heavily polluted for a week or even a month (clearly an unlikely scenario). Sensitivity analyses showed the models to be far more sensitive to streambed parameters than to aquifer parameters. Thus it would be more sensible to focus fieldwork on the measurement of streambed properties than on the more usually measured aquifer parameters.

Notes: This paper summarizes recent research and development of a particular process-based runoff generation model, the Institute of Hydrology Distributed Model. Surface and subsurface flow equations are linked in a hydrologically appropriate system to allow simulation of catchment runoff processes. Predictions can be made of channel flow, surface runoff and subsurface flow, pressure potentials and water contents. The structure and methods of the model are described and its data and computing requirements are outlined. Field and systematic applications are discussed, together with the work carried out on providing guidelines for use for the wider hydrological community.

Notes: In recent years the Yorkshire Region of the National Rivers Authority has employed the technique of physical modelling to assist in the hydraulic design of urban flood-alleviation schemes. The paper describes three examples of their use. On the River Worth at Keighley the introduction of a weir, to reduce siltation beneath a bridge, was modelled. The confluence of Batley Beck and Howley Beck in Dewsbury is located at the entrance of a culvert. A model was constructed and streamlining was introduced to improve self-cleansing and reduce head-losses. On the River Calder at Wakefield, two bridges and a weir form a complex hydraulic situation. The results of a physical model study were used to aid the calibration of a mathematical model of a much larger area. The paper reviews these model studies, indicating the costs and the likely savings resulting from reduced siltation. The paper concludes that physical modelling can provide a cost-beneficial aide to river-engineering design.

Notes: The ozonation of water is widely used within the drinking-water industry. The improvement of the performance of the Barcombe water-treatment works is envisaged. An ozonation stage and granular activated carbon filtration are being considered as an addition to the existing plant. As part of the investigation work, the influence of ozone on bromate formation was studied using a 3 m3/h pilot plant. The bromate production was found to depend upon (a) the applied ozone dose, (b) the contact period, and (c) the pH.Using ozone in an appropriate way will be of benefit to the treatment process as well as meeting the new World Health Organization health guidelines for drinking water.

Notes: This paper examines the limited information on the actual performance of sewage-treatment works as reflected in discharge quality from European Community member states. The control regimes for such effluents as well as the proportion of population served by sewerage and various levels of sewage treatment are contrasted between member states. Standards for river water quality and an assessment of actual river quality are then contrasted. These suggest that in the UK, river quality is considerably better overall than in other member states.

Notes: The occurrence of Giardia cysts in Scottish raw and potable waters was investigated. Giardia cysts were detected in 49% of raw waters, with concentrations of up to 1.05 cysts per litre, and in 19% of final waters, with concentrations of up to 1.67 cysts per litre. In some of the positive water samples the viability of the cysts was assessed by viewing the cyst morphology and inclusion/exclusion of propidium iodide. Viable cysts were detected in a proportion of both raw waters and positive final waters studied. Further investigations at 21 water-treatment plants revealed cysts in 9 (43%) of the raw waters, and in 4 (19%) of the final waters. Cysts were only detected in the final waters of plants in which cysts were also detected in the raw water. These data indicate that viable Giardia cysts may be ingested with potable water in Scotland.

Notes: The United Nations Drinking Water Supply and Sanitation Decade ran from 1981 to 1990. Much was achieved, but the target of a safe water supply and adequate sanitation for all was not. However, many helpful lessons of experience were derived, and these should guide work in this sector over the next several decades. The paper briefly reviews the achievements of the decade, and considers the lessons learned.

Notes: A fully automatic instrument has been developed to allow the on-line measurement of activated sludge settling characteristics. The monitor uses the derived data to calculate final sedimentation tank solids loadings and the required rates of returned activated sludge pumping. The instrument has been developed by Thames Water Utilities Limited and is now manufactured under licence by Phox Systems Ltd. It samples mixed liquor and returned sludge alternately and measures solids concentration, the initial settling rate (or rate of hindered settlement) and the stirred specific volume index. The stirred specific volume index at a standard solids concentration of 3.5 g/l is derived from the data. Actual and maximum final sedimentation tank loadings (kg/m2h) are calculated, and the required returned sludge pumping rate is predicted and may be controlled by the monitor. Tests have been carried out on a number of sewage-treatment works during several years of development, and some of the results are presented and discussed.

Notes: Macmillan's Chemical and Physical Data, by A. M. James and M. P. Lord. Published by The Macmillan Press Ltd, Houndmills, Basingstoke, Hampshire RG21 2XSComputer Techniques in Environmental Studies IV . Edited by Paolo Zannetti. Co-published by Computational Mechanics Publications, Ashurst Lodge, Ashurst, Southampton SO4 2AA, and Elsevier Science Publishers Ltd, Crown House, Linton Road, Barking IG11 8JU. 1992. ISBN 1 35166 792 X (Elsevier Applied Science), 1 85312 177 0 (Computational Mechanics Publications, Southampton) and 1 56252 106 3 (Computational Mechanics Publications, Boston, USA)Hydrogeological Processes in Karst Terranes. Edited by G. Günay, A. I. Johnson and W. Back. Published by IAHS Press, Institute of Hydrology, Wallingford, Oxon OX10 8BBActivated Sludge Ltd – The Early Years, by Eric Procter Coombes. Published by C. Roy Coombes, 10 St Luke's Road, Bournemouth BH3 7LTBetz Handbook of Industrial Water Conditioning. 9th edition. Published by Betz Ltd, Nat Lane, Winsford, CheshireChemical Water and Wastewater Treatment II. Edited by R. Klute and H. H. Hahn. Published by Springer-Verlag GmbH & Co. KG, Postfach 10 52 80, Tiergartenstrasse 17, D-6900 HeidelbergBS 7750: What the New Environmental Management Standard Means for your Business, by L. Grayson. Published by Technical Communications (Publishing) Ltd, 100 High Avenue, Letchworth, Herts SG6 3RRAdditional Tables for the Hydraulic Design of Pipes, Sewers and Channels, by D. I. H. Barr and HR Wallingford. Published by Thomas Telford Services Ltd, Thomas Telford House, 1 Heron Quay, London E14 4JDEutrophication: Research and Application to Water Supply. Edited by D. W. Sutcliffe and J. G. Jones. Published by the Freshwater Biological Association, The Ferry House, Far Sawrey, Ambleside, Cumbria LA22 0LPGroundwater Flow in Saturated and Unsaturated Soil, by H. Zaradny. Edited by R. B. Zeidler. Published by A. A. Balkema Uitgevers B. V., P.O. Box 1675, 3000 BR, Rotterdam, The NetherlandsTomorrow's Towns: An Urban Environment Initiative. Published by the Institution of Civil Engineers, 1 Great George Street, London SW1P 3AAUrban Drainage: The Natural Way. Published by Hydro Research & Development, Shearwater House, Clevedon Hall Estate, Victoria Road, Clevedon, Avon BS21 7RDPesticides in Drinking Water, by D. I. Gustafson. Published by Van Nostrand Reinhold, International Thomson Publishing, Berkshire House, 168–173 High Holborn, London WC1V 7AA

Notes: The protracted drought from 1988 to 1992 has focused attention upon the availability of water sources in England and Wales. The drought was most severe in the east and south-east parts of England, which also coincides with the areas having (a) the least available water resources, (b) the greatest forecast increase in demand, and (c) the majority of low-flow problems due to excessive authorized abstraction. Even with increasing attention being paid to demand management, there is a need to develop further water-resource schemes. Once local options have been developed it is likely that inter-basin transfers will be required.

Notes: The paper addresses the question of what is a ‘healthy’building, and whether the definition normally expressed in terms of occupant well-being has changed over a period of time. This definition is considered in relation to the relevant physical correlates, and suggested that they support the idea of the light, airy building. Air quality is then investigated to see how it can be, and perhaps more importantly how it is, incorporated into current solutions. Two design approaches are suggested from which a decision can be made as to use and profit from the shape of buildings; these are climatically rejecting and climatically interactive, and the use of either can result in solutions of differing orders of technical complexity. Finally it is suggested that some of these orders of complexity of solution are more difficult to operate healthily than others, and indications are given of possible ways ahead.

Notes: An investigation into the practicality of thermophilic aerobic digestion has been in progress at Castle Donington since 1989. The work has been carried out in a glassed steel insulated digester of 123 m3 capacity. Both auto-entraining and blower-assisted venturi systems have been evaluated.Both aeration systems were able, under favourable conditions, to remove at least 50% of the sludge COD. It was found that the additional flexibility of the blower venturi combination was necessary to accommodate crude sludges varying from 2% to 12% dry solids.Originally the plant was intended to operate at above 55C with a 10-day retention period. In practice retention periods at this temperature have been at least 15 days. The process has proved relatively susceptible to inhibition and requires the air supply to be closely matched to the load.The revenue costs have been, at best, around 47.3/tDS. This is competitive with small-scale anaerobic digestion, but not with the large digestion centre approach widely used in the UK. Unless pasteurization becomes a requirement for agricultural disposal, thermophilic aerobic digestion is unlikely to find wide use in this country.

Notes: An Extraordinary General Meeting of the Institution was held in the Royal Garden Hotel, London W8 8PT at 3.45 p.m. on Wednesday, 24 February 1993.

Notes: A serious biofouling incident at an overseas water treatment plant is described, together with the background information and recorded operational data which provided the subtle, but unheeded, physicochemical clues to the developing biological problem. At the time, however, it was not realised just what was causing the serious filtration problems and even upon discovery of the filter-clogging algae it was not immediately obvious what had caused their appearance, growth and subsequent rapid death within a sealed groundwater system. However, piecing together the story with hindsight from all the available clues has proved to be a fascinating and illuminating piece of biochemical detective work with unexpected conclusions which have wider ramifications within the water industry.

Notes: Over the past decade, much attention has been paid to the assessment of water distribution networks. Attention now is turning towards the larger diameter trunk mains. The increased scale and cost of investigative work means that a change of approach is needed and, in some cases, new investigative techniques.This paper discusses the general approach to the appraisal of trunk mains (and aqueducts) and, based on practical experience, considers solutions to a number of problems associated with inspection work.A case study is presented, based upon a preliminary appraisal of the Vyrnwy Aqueduct, which was carried out in 1988–89. The aqueduct was first commissioned in 1891, and now contains some 325 km of large diameter pipes, in both cast iron and steel.

Notes: Northumbrian Water Limited has thirty-four bathing waters and a substantial investment programme to ensure that these waters meet EC standards by 1995. One project within this overall programme is the Seaton Carew Sewerage Scheme. Seaton Carew lies on the southern edge of Hartlepool which has a population of 95000. The scheme will combine existing flows into new foul and storm-sewage outfalls. The headworks will incorporate screening, grit removal and pumping stations with substantial measures for odour control. Hydraulic operating regimes using active pump control and passive flume control have been investigated to ensure efficient treatment for a wide range of flows. The onerous design, manufacture and construction programme has required the development of new approaches to procuring the work, whilst maintaining a substantial element of competition. The various programmes have been substantially overlapped to ensure that the scheme is completed by April 1993.

Notes: Significant differences in the way that basic water-treatment processes are engineered in Europe and the US have been apparent for nearly 50 years. In the US, standardized and rather conservative treatment works have been in wide use for decades, whereas in Europe there is a wide range of designs, many having important advantages in terms of cost and efficiency. It is significant that in Europe, specialist treatment plant contractors make a major contribution to the development of new designs, whereas in the US this is mainly the responsibility of consultants. Drinking water quality standards are becoming more complex, and it is considered that the technologies used on the two continents for dealing with the newer contaminants will be similar. The system used in the US for developing water quality regulations, which is scientifically based and involves considerable consultation with the water industry, has major advantages over that used in the European Community.

Notes: The importance of the atmospheric pathway to the pollution of surface waters, and in particular the North Sea, has been confirmed by studies carried out during the last decacde. However, there are still large uncertainties associated, not only with the quantities of pollutants measured, but also with the methodologies followed to obtain estimates for large areas such as the North Sea. A large part of the uncertainties can be attributed to the lack of representative and reliable measurements at open sea. This paper discusses methodologies which have been used and gives an overview of results reported so far. Some model results on the deposition distribution over the North Sea of nitrogen and lead are presented, and the paper considers the research needs to improve the understanding of air–sea exchange processes and the research which is currently being carried out.

Notes: Quality assurance for the water industry and its suppliers is being seen to be of ever-increasing importance as a means of meeting the demands of customers and giving confidence to regulators. The creation of the Water Industry Certification Scheme demonstrates the industry's increased level of commitment to quality assurance.This paper considers the requirements and benefits of certification of quality systems with particular reference to the BS 5750/EN 29000/ISO 9000 series of standards. The requirements for certification in the water industry are discussed in terms of corporate policy, what is stated in the standard, and how the requirements of some elements of the standard might be interpreted by a certification body.

Notes: Corporate Environmental Responsibility: Law and Practice, by John R. Salter. Published by Butterworth Law Publishers Ltd, 88 Kingsway, London WC2B 6ABAn Engineer's Guide to Water Treatment by George S. Solt and Chris B. Shirley. Published by Ashgate Publishing Group, Gower House, Croft Road, Aldershot, Hants GU11 3HRPractical Conservation: Water and Wetlands, by Pamela Furniss and Andrew Lane. Published by Hodder and Stoughton Ltd, Mill Road, Dunton Green, Sevenoaks, KentEnvironment Industry Yearbook, published by Environment Press, Abacus House, Manor Road, West Ealing, London W13 0ASWater Treatment Handbook, by Degrémont. (6th English Edition). 183 Avenue du 18 juin 1940–9 2508 Ruiel – Mal Maison, Cedex, France; UK distribution Intercept Limited, PO Box 716, Andover, Hampshire SP10 1YG

Notes: Single product scaling and relative-to-reference scaling were compared on the basis of numbers of significant differences among chocolate milks and among vanilla yogurts using both trained and untrained panels. The study involved 920 comparisons among product means with appearance, flavor and mouthfeel attributes. Although there were a greater number of significant t-tests when the relative-to-reference scales were used by both trained and untrained panels, the differences between scale types were minor. Panels showed no advantage with the type of scale they used first. The two methods may be used with equal efficiency for sensory evaluations.

Notes: Consumers differ dramatically in their sensory preferences for products. This paper assesses the relative importance of appearance, taste/flavor and texture as characteristics that drive acceptance for a complex pie product. The paper classifies consumers as being driven by one or more sensory attributes in their judgment of product quality. To do so, each consumer's liking rating is regressed against each separate attribute liking. The coefficient (M) of the linear equation “Overall Liking = M (Attribute Liking) + B″ measures the relative importance of the sensory attribute as a driver of overall quality.

Notes: Emulsified turkey sausages (ETS) were prepared using varying concentrations of sodium chloride (NaCl; 1.5 to 2.0%), sodium tripolyphosphate (STPP, 0 to 0.5%), and sodium acid pyrophosphate (SAPP, 0 to 0.25%). The sensory characteristics (response variables) of saltiness, soapiness, and texture were evaluated using a trained taste panel. Response surface methodology was used to design and analyze this study. Over the levels of STPP and SAPP, saltiness increased as levels of NaCl were increased. When STPP and SAPP were evaluated in combination with NaCl, saltiness increased slightly as levels of STPP were increased; and saltiness decreased as levels of SAPP were decreased. Soapiness increased at low levels of NaCl (1.5%) as STPP increased. Texture firmness decreased as SAPP increased and STPP decreased at low levels of NaCl (1.5%). Results suggest that sensory perceptions in ETS products are a combination of NaCl, SAPP, and STPP mixtures.

Notes: The objectives of this study were to determine the distribution of the sensory panelists’ ability to detect differences and to improve the triangle test by minimizing unnecessary guessing. The triangle test was modified to include the use of economic incentives through which panelists voluntarily revealed their ability to detect differences. Panelists were asked to estimate their ability to detect differences and the probability of identifying the odd sample in a triangle test. They were then organized into three ability groups according to their responses. Double triangle tests, followed by triangle tests with economic incentives, were used to evaluate a cereal product and a beverage. The ability to detect differences was modeled as a probability, and the distribution of panelists was estimated. The economic incentives test was more effective when used with the beverage in which differences were less difficult to detect. We found that the economic incentive test discouraged the panelists from guessing unnecessarily, thus increasing the motivation of the panelists to detect differences, and allowing researchers to determine the distribution of discrimination ability.

Notes: Perceived bitterness in drinks is known to fade slowly over time. Time-Intensity curves are a means of studying this fading process. K subjects record the perceived bitterness intensity by moving a slider on a monitor using a mouse. Usually average TI-curves are calculated to give a representation of the TI-curve for one particular object. The problem is that there often are large individual differences, so the average TI-curve is not always a good representation. An alternative is to perform a Principal Component Analysis on the matrices of objects by individual TI-curves for each object. The resulting, so-called, Principal Time Intensity Curves (PTIC's) are better representations than the average curves. Often the PTIC's for the different products are hard to distinguish. In this case a noncentered PCA of the matrix with curves gives results which show more differences between the products.

Notes: Consumer test subjects were split into four groups: (1) Rewarded — told they would receive payment; (2) Unrewarded — told they would not receive payment; (3) Hungry — told not to eat before the test; and (4) Pre-fed — told to eat a meal before the test. Hedonic responses for four breaded fish samples were collected. The test design was then repeated using microwave popcorn as stimuli. Rewarded subjects and hungry subjects rated samples higher than did either the unrewarded subjects or the pre-fed subjects. The responses of both the rewarded and the hungry subjects indicated no hedonic differences between samples; but among the unrewarded and the pre-fed subjects, significant differences between samples were found. Results present a dilemma for those experimenters using acceptance ratings by consumers to guide product development. This paper discusses the issue of whether these, and other unresolved factors, need to be controlled when conducting consumer tests.

Notes: Difference testing methods are extensively used in a variety of applications from small sensory evaluation tests to large scale consumer tests. A central issue in the use of these tests is their statistical power, or the probability that if a specified difference exists it will be demonstrated as a significant difference in a difference test. A general equation for the power of any discrimination method is given. A general equation for the sample size required to meet Type I and Type II error specifications is also given. Sample size tables for the 2-alternative forced choice (2-AFC), 3-AFC, the duo-trio and the triangular methods are given. Tables of the psychometric functions for the 2-AFC, 3-AFC, triangular and duo-trio methods are also given.

Notes: The objective of this research was to examine some considerations arising from incorporating tasting into a conjoint analysis procedure studying the effects of taste, brand, price and health claim on the buying intent for strawberry yogurt. Specifically, the considerations were: (1) whether people could remember the sensory qualities of the products tasted well enough to re-identify them in a follow-up test, and (2) whether their memory of their liking for the products was stable. Two hundred people who purchased and ate strawberry yogurt participated in a three-part test session. Part 1) They tasted and rated their liking for three yogurt samples and either did or did not take notes on the sensory attributes of the yogurts. Part 2) They rated 27 mock yogurt labels representing 3 brands x 3 taste qualities x 3 prices x 3 health claims on a buying intent scale. Part 3) They rated their liking of the three yogurt samples either from memory or by retasting and they attempted to re-identify the three yogurt samples. Taking notes improved the proportion of completely correct re-identifications (75% vs 50%). Liking reratings from memory were as stable as liking reratings by retasting. Taste and health claim had the largest influence on buying intent; brand had little influence on buying intent.

Notes: Interactions between perceptions of texture and volatile flavors were assessed by free-choice profiling using gelatin desserts as a model product. Gels were prepared with all combinations of 2 levels of gelatin, and 2 concentrations of 2 different flavors. A trained sensory panel profiled each sample for aroma, flavor, and oral and manual texture. Generalized Procrustes Analysis was carried out separately for each sensory modality. The results indicate that while gelatin concentration and flavor type both modified perception of flavor, flavor concentration did not. Gelatin content influenced instrumental, oral, and manual evaluations of texture; however, the type and level of flavoring had little influence on oral perception of texture.

Notes: A total of 450 consumers participated in a test to determine whether questionnaire length, presence of key diagnostic questions or serving position affected their hedonic discrimination among yellow cakes. Consumers evaluated four yellow cakes representing a 2 × 2 factorial design of texture and flavor flaws. They used one of the following six questionnaires: only a 9-point hedonic scale, a 9-point hedonic scale with open end questions, and four others comprising a 2 × 2 factorial design with two levels of questionnaire length and two levels of questionnaire completeness. Neither the presence of key attribute questions nor the length of the questionnaire affected the value or the sensitivity of the judges’ overall liking scores. Samples tasted first received higher hedonic scores than those same samples tasted second throughfifth. Judges could discriminate among the samples on the basis of overall liking best when samples were tasted fourth or fifth.

Notes: Temporal oral burn profiles for cinnamaldehyde, piperine and capsaicin were quantified using time-intensity (TI) parameters. Despite large judge-to-judge variation, TI profiles for eaters and noneaters of chile peppers differed significantly. Eaters had lower maximum intensities, shorter total times, and slower maximum rates of onset and decay. Judges with substantial desensitization also had shorter time-to-maximum intensities. Desensitized judges not only scored the burn of capsaicin as less intense, but also the burn of cinnamaldehyde and piperine. The burn of cinnamaldehyde solutions increased and decayed quickly; whereas, burns due to piperine and capsaicin increased and decayed slowly. Capsaicin compared to cinnamaldehyde, had time-to-max, plateau time, and total time that were 1.5, 2.0 and 3.0 fold larger; whereas, the maximum rates of onset and decay were 0.7 and 0.2 fold smaller, respectively. Temporal differences are believed to reflect differences in neural pathways for the irritant species.

Notes: Sensory laboratories develop vocabularies for new products and even for some old products so that Quantitative Descriptive Profiling can be carried out. It is common to find that the vocabulary developed is too extensive to be used on a routine basis. One method of reduction is to use statistical methods to identify sub-sets of descriptors. This paper describes how these methods have been used in the development of a vocabulary for fermented milks. Sub-sets of the vocabulary were found, using the communalities from the principal component analyses, and these were verified to cover the sensory space by Procrustes Rotation. A confirmatory experiment was carried out using the reduced vocabulary. A Procrustes Rotation of the scores derived from the separate analysis of these experiments verified that they were in excellent agreement.