Field Test Procedures Research Articles

ASSESSING VISUAL FUNCTION IN CLINICAL PRACTICE

Tests of visual function provide the clinician with essential information regarding the performance of a patient's visual system. At the present time, primary open-angle glaucoma is diagnosed by means of specific patterns of peripheral visual field loss and characteristic appearances of the optic nerve head. The gold or reference standard used to investigate peripheral visual function is evaluation of the visual field or perimetry. Visual field testing has been used for more than 150 years 31 and represents the most common method of assessment of peripheral visual function. The ability of perimetry and visual field testing to provide useful clinical information has been responsible for its long-term use as a diagnostic procedure. Although a variety of stimuli may be used for perimetric investigations, this article concentrates upon describing achromatic (white-on-white) perimetry with particular reference to the Humphrey Field Analyzer. Two recently developed visual field testing procedures that have demonstrated clinical utility are also discussed: short-wave automated perimetry (SWAP) and frequency doubling technology (FDT) perimetry. It is important for the reader to recognize that glaucoma may also produce adverse effects upon a variety of other nonperimetric visual functions. Glaucoma has been reported to degrade central color vision, 92 both spatial 8 and temporal 104 contrast sensitivities, vernier acuity, 79 and visual acuity by end-stage disease, although these functions appear to lack the discriminatory power of standard automated perimetry.

Quantitative phosphorus measurement: A field test procedure for archaeological site analysis at Piedras Negras, Guatemala

Currently there is a wide interest in the use of chemical analyses for the evaluation of anthropogenically altered soils and other archaeological deposits. Because soil phosphorus levels increase in areas of human habitation, and leave a permanent signature that can only be removed by erosion of the soil itself, phosphorus mapping has become a popular field procedure to indicate areas of habitation where overt evidence of ancient occupance is absent. We have developed a methodology to obtain accurate acid-extractable phosphorus concentrations (mg/kg) in calcareous soils under the primitive field conditions of Piedras Negras, Guatemala. Predicated on Mehlich-II acid extractant and colorimetric methods, this procedure processed 36 samples per hour at very low cost per sample. Based on eight replicate measurements of a group of samples, the coefficient of variation of the procedure was 8.3%. Subsequent analysis of 35 soil samples in a controlled laboratory revealed a moderate correlation of 0.44 between the Mehlich-extractable phosphorus and total phosphorus. The correlation was 0.91 between the Mehlich procedure and Olsen bicarbonate extractable phosphorus, indicating that Mehlich-based results are similar to those obtainable using a traditional extractable phosphorus method on soils of neutral to alkaline pH. There was a moderate correlation between Mehlich P and ring-test rating (r = 0.42). The wider dynamic range of the Mehlich extraction, coupled with the use of a battery-operated colorimeter, facilitated the finding of a refuse midden within an area of phosphate enriched soils. Further tests indicated that phosphorus concentrations measured in the field deviated by only 7% from those made under controlled laboratory conditions. © 2000 John Wiley & Sons, Inc.

Steel girder bridge field test procedures

Research has shown that in most cases, bridges exhibit capacities higher than analytical load capacity rating predictions. Field testing has become an acceptable means to determine a more accurate estimate of a bridge’s safety capacity. Many factors not considered in the design process contribute to the response of a tested bridge. Several of these, like the actual load distribution and additional system stiffness from curbs and railings, are welcome benefits and can be used to increase weight limits on bridges. However, there are also contributions from bearing restraint forces and unintended composite action that may not be reliable during the service life of the structure. This paper presents systematic field test rating procedures that quantify these contributing factors so that owners may remove unwanted contributors and retain the reliable benefits. The procedure is demonstrated for a three-span steel girder bridge.

The “thin man” phenomenon: a sign of cortical plasticity following inferior homonymous paracentral scotomas

AIM To investigate an image distortion, experienced by patients with homonymous paracentral scotomas. METHODS Two consecutive patients with right inferior homonymous paracentral scotomas resulting from ischaemic brain insults were examined....

The Relationship of Lactate to 1-Mile Walk Performance in Women Aged 60 to 70 Years

The purpose of this study was to examine the relationship between selected physiological variables and lactate accumulation at the end of a l-mile walk test (MWT) in older women (mean ± SD: 64.6 ± 3.1 years). Seventeen women with a peak (ml · kg-1 · min-1) of 21.1 ± 4.2 volunteered to participate. Physiological data were obtained via a COSMED K2 miniaturized O2 analyzer with telemetric capabilities during a maximal treadmill (TM) test and MWT. Blood samples were obtained from the ear lobe for lactale analysis immediately before and after the treadmill test and MWT. Subjects performed the MWT in 15.4 ± 1.4 min at an intensity of 76% of peak and 86% of HRmax. The blood lactate accumulated at the end of the MWT was 2.61 ± 1.47 mmol/L. Peak lactate following the maximal treadmill test was 3.8 ± 1.42 mmol/L. HR during the test was significantly related with blood lactate (r= .65, p< .01). The lactate values observed during the lest suggest that the I-mile walk test is a suitable field testing procedure for older women.

Field Trial Models For the Evaluation of Hairy Wart Treatment Products

Hairy heel warts remain a major concern for dairy producers because of the effect on milk yield. Field test procedures have been developed for the evaluation of hairy wart treatment products. Potential treatment products are applied daily using a garden sprayer after pre-washing the affected area with water. Product application is done once a day for 10 days. The hairy heel wart is visually evaluated on a five part scale that includes: lesion size, description, pain, color, and swelling. Evaluation of the lesion is conducted daily to follow change in appearance of the lesion. Subjective scores are converted to a numerical index in order to develop a "total lesion score." These field trial methods are being used to develop non-antibiotic treatment products for hairy heel warts. Initial results indicate efficacy for an iodine formulation with high free iodine levels.

Water-Droplet-Size Determination for Improved Oil-Treater Sizing

Abstract The sizing of crude-oil treaters is still very much an art. While it is possible to perform laboratory studies on crude-oil samples, no one has published a proven field-test procedure that can be used to pick an appropriate treating temperature and treater dimensions for a specific field.

Nondestructive evaluation of pavements using spectral analysis of surface waves in the frequency wave-number domain

The potential of using Spectral analysis of surface waves (SASW) for nondestructive testing of pavement and soil sites has been demonstrated in several publications. The usual SASW field testing and data analysis procedures and the assumption of a single propagation mode yield accurate results when there are no sharp changes in the stiffness of the site with depth. When this is not the case, however, difficulties arise in the interpretation of experimental data due to the participation of more than one mode in the wave field. In an earlier study, the multiple filter/crosscorrelation technique was suggested for analyzing multi-mode SASW signals. This technique, however, may not yield accurate results when propagation modes are closely spaced. A more general method using spectral analysis in the frequency wave-number domain is presented in this paper. Formulas are presented for determining a reasonably small number of surface measurements, and the accuracy of this method in resolving experimental dispersion curves is demonstrated for a pavement site.

A Soil Identification Method for Potential Road Construction Problem Sites on the Olympic Peninsula, Washington

Several logging road subgrades and cut slopes failed under wet construction conditions in the 1980's on the Olympic Peninsula in Washington. Although standard laboratory soil test results did not indicate this would occur, field tests showed possible soil failure. A majority of these soils were coarse-grained with significant amounts of fines (silt and clay). Field soil identification methods indicated that these soils had a moisture content above the plastic limit; the laboratory test results were mostly non-plastic. During construction, the soils performed like plastic soils with low strength values, although in the laboratory the soils had suitable strength values for normal road construction methods. An hypothesis that standard laboratory tests for soil strength values do not detect organic and/or clay minerals that lead to failure under wet road construction conditions on the Olympic Peninsula was proven correct. A combined field and laboratory testing procedure was developed for identifying these soils. (A)

An integrated approach to rock stress measurement in anisotropic non-linear elastic rock

A mathematical model that allows the simultaneous introduction of non-linear elasticity and transverse isotropy for the interpretation of doorstopper stress measurements is presented, along with the description of a field testing procedure that gives the parameters required in this model. Results from stress measurement simulations performed in the laboratory on a Barre granite block and on rock salt cylinders are presented in order to validate the proposed methodology. A sensitivity analysis of aniseffects of anisotropy and nonlinearity using the simulation results is also performed and shows the influence of both phenomena on calculated stress intensities and orietations.

The Dutch Version of the Nottingham Health Profile: Investigations of Psychometric Aspects

Data on the adaptation, reliability, and validity of the Dutch version of the Nottingham Health Profile are discussed. The linguistic adaptation of the English version into Dutch is described, followed by the field-testing procedure and the analyses of data from 276 selected subjects from an average general medical group practice in a village nearby Rotterdam. The internal consistency, Cronbach alphas, of the subscales varied from .70 to .85. Test-retest measures for 51 patients with cardiac problems gave Spearman correlations from .69 to .92, while the interscale relationships yielded six relatively independent areas of discomfort and stress. By means of logistic regression analysis on differences between old versus young, male versus female, and healthy versus ill individuals, discriminant validity was satisfactory. Findings suggest that the psychometric aspects of the Dutch version, also seen from a cross-cultural point of view, are sufficient. Nevertheless, further research on reliability and validity of the Dutch version is required to establish its usefulness with different patient groups.

Systematic Screening for Preschool Behavioral Disorders

Research in the area of behavioral disorders suggests chronic problems in the underreferral and underrepresentation of at-risk children. Systematic preschool screening procedures for identifying such students are conspicuous by their absence in both the professional literature and actual practice. The present study adapted the elementary version of Systematic Screening for Behavior Disorders (SSBD) to a select preschool Head Start population. Primary modifications of the SSBD were made in the decision rules determining which children pass through the multiple gated system to the next stage. A secondary modification was the elimination of Stage III observation of Academic Engaged Time (AET) because of its developmental inappropriateness for preschoolers. Of the Stage II subjects, 58% passed into Stage III peer social behavior observations and 5% of the Stage III sample was referred to child study teams for further assessment. Implications for further research with this population, utilizing large-scale field testing and validation procedures, are presented and discussed.

The Thermal Probe—Measurement of the Thermal Conductivity and Drying Rate of Soil in the Field

Abstract The thermal probe is a metal rod with an internal heating element and temperature sensor. In the field it is pushed into a predrilled hole in otherwise undisturbed soil, and the thermal properties of the soil are estimated from the temperatures recorded at intervals after a constant power is supplied to the heating element. The following are discussed in this paper: the theory behind the methods for identifying the thermal properties, the design of the probe and auxiliary equipment, the results of laboratory trials, the field testing procedures, and the results of field trials. The probe, the theory, and the testing procedures extend the application of thermal probes from their traditional use for thermal conductivity measurement beyond their more recent use for the study of the thermal stability of soil near underground power cables to the measurement of native thermal conductivity, dry thermal conductivity, and the rate at which drying fronts move within the soil.

Strength Correlation Factor for Residual Soils

Complete weathering of parent rock has resulted in the formation of residual soils that cover most of the land area of Sri Lanka. The physiography of the island demands that new engineering structures be located on sloping ground, thus posing many problems. The residual soils are heterogeneous due to variable weathering of the jointed rock mass. The heterogeneity of residual soils is due to the influence of relict joints, presence of boulders, and variability of the soil matrix. The repercussion of this heterogeneity is that properties of small samples of residual soils are unrepresentative of the mass, thus rendering conventional methods of field testing, laboratory testing, and analysis procedures for slope stability unsuitable. Heretofore, there have been no testing and analytical models available to represent residual soils. This paper describes an alternative method to predict shear strength parameters of residual soils by a correlation factor obtained from a multistage triaxial test and conventional slope stability analysis. Three landslides were investigated and analyzed to obtain the field shear strength parameters using the back analysis technique. On comparison with laboratory strength parameters, obtained from multistage triaxial tests, a correlation factor was ascertained. This correlation factor can be used to modify laboratory shear‐strength parameters to obtain field shear‐strength values of residual soils for design purposes.

Acid Soil Stress Tolerance in Tissue Culture‐Derived Sorghum Lines

Acid soil stress limits crop productivity on nearly one‐half of the nonirrigated arable land in the world. Improvement of acid soil tolerance in sorghum [Sorghum bicolor (L.) Moench] has been approached through conventional breeding programs and more recently through biotechnology. This study was initiated to determine if improved acid soil tolerant tissue culture regenerates could be developed from sensitive parental lines and whether tolerant regenerants with desirable agronomic traits could be selected under field stress conditions. Tissue culture regenerated lines of sorghum and their non regenerated checks were field tested for acid soil [Typic Kanhapludult] tolerance (50% Ai saturation at pH 4.2‐4.6) near Griffin, GA, from 1986 to 1990. Two R5 lines derived from ‘Hegari’ and two R5 lines from RTx430 demonstrated improved acid soil tolerance in 1989. Field test results indicated that these four lines had significantly higher ratings for vigor (2.6‐3.4 vs. 4.8‐4.9), plant survival (12–30 vs. panicles harvested (2–9 vs. 0), and seed yield (20‐85 g plot−1 vs. 0) than their nonregenerated checks. During 1990, selected R7 lines were advance tested on acid soils near Griffin with similar results. Three of these improved selections were then evaluated for early seedling development in a greenhouse soil study using the same acid soils from the field. These results showed that one Tx430 regenerated line had improved root development at low pH during the seedling stage. This research indicated that variation for acid soil stress tolerance was produced through tissue culture and that agronomically desirable genotypes were selected using appropriate field testing procedures and stress levels.

Development and validation of the Nurse-Midwifery clinical data set

This paper describes the procedures used to develop and validate the Nurse-Midwifery Clinical Data Set (NMCDS), a uniform, standardized tool for the purpose of data collection about midwifery clinical practice. The instrument was developed under the auspices of the ACNM Division of Research, and it was shown to be valid for the purposes of quality assessment data collection through the use of specific instrument development and field testing procedures. These procedures included consensus panel development, expert panel review, standardization, feasibility analysis, and validation through comparison with previous outcome data and record review. The 1990 version of the NMCDS is appended to the article.

Procedures for Prediction of Dynamic Lateral Pile Group Response in Clay from Single Pile Tests

Abstract The design of pile foundations for dynamic lateral loads is significant in the design of both offshore and onshore structures subject to vibratory loads and earthquake motion. Sophisticated numerical models are available for predicting the response of these foundations; however, simple and cost-effective methods are needed to confirm the analysis results and improve the understanding of the overall system behavior. A field testing procedure consisting of slow cyclic load tests and plucking tests is suggested and integrated with simplified single-degree-of-freedom and modal analyses of the test results to produce response functions for dynamic design. The technique is particularly attractive because the field tests may be performed quickly and economically on a test pile or piles installed at the site to determine bearing capacity and/or drivability. The proposed test and analyses procedures were applied to a single pile and nine-pile group installed in stiff clay and tested at the University of Houston pile test facility, and the results are compared favorably with more detailed response information published previously. A good approximation of the pile group dynamic behavior was obtained from the simplified single pile response analysis.

Eddy current probe performance requirements : Southwest research institute, San Antonio, Texas, (United States), AD- A208-240/2/GAR, 141pp. (Dec. 1988)

Abstract : This study resulted in the development of a procurement specification for single-coil, absolute eddy current probes (shielded and nonshielded) which are used by the USAF with the Hocking UH-B (or equivalent) instruments for inspection of aluminum airframe structures. The specification was necessary because the USAF currently has no adequate means of assuring the quality of eddy current probe performance. The specification establishes minimum performance requirements and associated test methods for determining performance. It also establishes a standard nomenclature for the salient features of probes and a standard probe numbering system that allows the basic characteristics of the probes to be identified on the probe in a uniform manner. A simplified field test procedure for these probes which incorporates a subset of the tests in the specification was also developed. To establish performance requirements for the specification, the major parameters determining probe performance were defined. Acceptance limits for these parameters were guided by measurements from 30 shielded and 30 nonshielded probes. The probes were obtained from USAF inventory at numerous Air Force bases and were representative of proves in current use. The acceptance limits were set to reject probes with poor performance and not reject a high percentage of probes with typical performance. Keywords: Flaw detection probe standards; Electrical measurement test methods.

Maturity Genotype of ‘Mukden’ Soybean

A field test procedure using soybean [Glycine max (L.) Merr.] maturity isolines has indicated that ‘Mukden’ is of the genotype e3e3, whereas the delayed flowering response of Mukden to natural daylength extended to 20 h with cool‐white fluorescent light indicated that it should be E3E3. Mukden was crossed to E3E3 and e3e3 testers and progeny tested under the extended daylength conditions. Results confirmed that Mukden is E3E3. Data from the isoline‐tester field procedure were examined for E3 and e3 tester effects in comparison with those of E2 and e2. It appears that if there is not a greater mean effect, a larger range, and a greater phenotypic variance present for the alleles of a tester gene, then additional information is needed before maturity genotypes at that locus can be assigned with confidence to tested cultivars.

Estimation of moisture content in timber using ultrasonics

This paper presents the findings of a research programme on the estimation of moisture content in timber using ultrasonics, by developing working relationships between ultrasonic wave velocity, temperature and percentage moisture content in timber samples during kiln drying. A detailed experimental programme was undertaken to develop relationships between ultrasonic wave propagation velocity and temperature, and between velocity and percentage moisture content for a large number of timber samples. The experimental programme was primarily restricted to samples of jarrah timber, but the procedures can be applied to other species. The results show conclusively that both temperature and moisture content have a significant effect on the ultrasonic wave propagation velocity in timber, whereas material density does not. Thus, ultrasonics can be used to monitor variations in percentage moisture content during the drying process in a kiln environment. A simple field-testing procedure has been developed for monitoring moisture content in timber using ultrasonics either manually (with a hand calculator) or incorporated into a computer program for on-line monitoring. The procedure is based on simple quadratic equations derived from a statistical regression analysis of velocity and temperature relationships, and velocity and percentage moisture-content relationships. To overcome any measurement inaccuracies due to density variations or other factors, the recommended procedure involves the initial calibration of each sample board.