Sag Test Research Articles

Functional status as a predictor of the incidence of falls in 10-year follow-up: results from the RAC-OST-POL study.

The aim of this prospective study was to establish the influence of baseline functional status on the incidence of falls. The study was performed in an epidemiological sample of postmenopausal women from the RAC-OST-POL study. At baseline there were 978 postmenopausal women with a mean age of 65.9 ± 7.6 years, and at the end of 10-year follow-up 640 patients with a mean age of 65.04 ± 6.95 years remained in observation. Functional status was established at baseline using a stand up and go test (SAG) and the Lawton Instrumental Activities of Daily Living (IADL) scale. Afterwards, data on fall incidence were updated annually using phone interviews. In a 10-year period of observation, in 384 (60%) women at least one fall occurred. At baseline, 90% of subjects achieved maximal value in the IADL scale (24 points). Although the difference between mean IADL score in those who fell and did not fall was noticeable (23.50 ± 1.68 vs. 23.65 ± 1.47, respectively), the category of any IADL score below 24 points was significantly more frequent in women with falls (71.9% vs. 28.1%; chi-square 4.2, p < 0.05). The SAG score in the subgroup with falls was (10.75 ± 3.39) and did not differ in comparison to subgroup without falls (10.27 ± 2.72). The baseline result of the IADL scale but not that of the SAG test are related to the incidence of falls in a 10-year prospective observation. Adequate correction of functional status may benefit patients and reduce the fall rate.

Comparative Investigation of Hair Shampoos Formulated Using Different Herbal Extracts

Cosmetics have fascinated the human race for ages. Cosmetics have been found to benefit in several ways such as enhancing appearance, protection, cleansing etc. If fortified with the benefit of herbal ingredients, these personal care products have proven to be a boon for many. The current study involves the formulation of seven shampoos using different herbal extracts and their comparative investigation for physicochemical and performance characteristics. Various herbal extracts using components such as coffee, fenugreek, green tea, bringaraj, onion seeds, orange oil, and lemon oil were developed and compared against the marketed standard. The effect of various extracts on the parameters such as surface tension, foam test and foam stability test, viscosity, cleansing test, sag test, dirt dispersion, wetting time and pH was successfully tested. All the formulations were found to be beneficial in eliminating oil, dirt, and dandruff, encouraging smooth, silky hair appearance, fortifying and darkening hair without altering or harming hair tresses. Our findings suggest the incorporation of fenugreek, lemon and orange peels to increase the cleansing ability. However, the inclusion of onion seeds and green tea has been found to be beneficial in the generation and stability of the foam.

Prevention of hematite settling using perlite in water-based drilling fluid

The stability of the weighting materials in the high-density water-based drilling fluid was remarked as a serious issue to be controlled. It can cause several problems including formation fracturing, circulation loss, well control issues, etc. The usage of an anti-sagging chemical as a drilling additive is one of the sagging mitigation methods. In this study, amorphous volcanic alumina silicate (perlite) was evaluated as an anti-sag additive for hematite water-based drilling fluid. Several experiments were conducted to assess the perlite efficiency including static and dynamic sag test, mud properties measurements such as filtration behavior, filter cake properties, rheological and viscoelastic behavior. The tests were conducted at elevated temperature (250 °F). Perlite concentration was varied from 0, 1, 2, 3, and 4 lb/bbl. The obtained results showed that the loaded perlite was able to improve the mud stability and eliminate the sagging under static and dynamic issues at an optimum concentration of 4 lb/bbl. In term of filtration properties, there was an obvious improvement that could be observed through the reduction of filtration volume with 50% and filter cake thickness. In addition, the perlite contacting drilling fluid was able to form a thin and dense filter cake layer. The filter cake porosity and permeability were decreased by 24% and 68%, respectively. The rheological and viscoelastic behaviors were improved as well by the addition of perlite.

Clinical outcome after knee ligament reconstruction with tendon allografts

PurposeThe purpose of this study is to investigate the clinical outcome for patients after knee ligament reconstructions with allografts at a university hospital.MethodsA total of 33 patients received allografts for reconstructive knee surgery between 2007 and 2017. The follow up evaluation consisted of a clinical knee examination including evaluation of range of motion (ROM), lateral and medial laxity, the Lachman test, the Pivot shift test, the sag test, the posterior drawer test and checking for patellofemoral pain. The following patient-reported outcome measures (PROMs) were used; the Lysholm Function Score, the Tegner activity score, and the Knee injury and Osteoarthritis Outcome Score (KOOS).ResultsTwenty-one (64%) patients were available for the follow-up evaluation and the mean follow-up time was 4.8 years. A total of 16 out of 21 patients had multiligament injuries of which the ACL was the ligament most frequently ruptured. At the time of follow-up, 14 out of 16 patients (87%) with ACL injury had Lachman test grade 0 or grade 1 + , and 12 out of 13 (92%) had a pivot shift grade 0 or 1 + . The mean Lysholm Score was 74. All mean KOOS subscale values were ≥ 59 at the follow-up. The preoperative Tegner activity score was 3 (range, 1–6) and 4 (range, 2–6) at follow up. There were no deep postoperative infections. A total of 19 out of 21 patients (90%) reported that they would have undergone surgery again had they known the clinical outcome in advance.ConclusionsThe patients improved from the preoperative score to the follow-up score in the knee-related Quality of Life (QoL) KOOS subscale. None of the patients were diagnosed with deep postoperative infections.

Validation of a novel functional test for assessing metamorphopsia using epiretinal membranes as a model

Current tests for assessing metamorphopsia do not account for confounders such as perceptual filling-in and spatial redundancy, which affect its sensitivity and repeatability. This proof-of-concept study aimed to assess the performance of a novel laboratory-based psychophysical test (Line Sag Test, LST) which addresses these issues for quantification of metamorphopsia in idiopathic epiretinal membranes. The LST quantifies perpendicular metamorphopsia at three eccentricities (3°, 6°, and 9°) along eight meridians (45° steps). Metamorphopsia was assessed using the LST and Amsler grid and the hit rates of both tests for detecting metamorphopsia were compared. Normal metamorphopsia scores using the LST did not differ significantly from 0 and fell within one step-size (p = 0.500). The LST detected significantly more cases of metamorphopsia than the Amsler grid (14/21 versus 3/21) (p = 0.003). Similarly, significantly more cases of visual distortions in asymptomatic iERMs were detected using the LST than the Amsler grid (11/18 versus 0/18) (p = 0.008). The LST has a higher hit rate compared to the Amsler grid (67% versus 14%). This work demonstrates a psychophysically-robust functional test addressing perceptual confounders is more sensitive for quantifying and localising metamorphopsia in macular disease, particularly in asymptomatic disease.

Characteristics of Heat Resistant Aluminum Alloy Composite Core Conductor Used in overhead Power Transmission Lines.

The heat resistant aluminum alloy wire composite material core conductor (ACCC/HW) which was used in overhead transmission lines is developed and studied in this work. The composite material core is carbon fiber/glass cloth reinforced modified epoxy resin composite. Tensile stress tests and stress-strain tests of both composite core and conductor are taken at 25 °C and 160 °C. Sag test, creep test and current carrying capacity test of composite conductor are taken. The stress of composite conductor are 425.2 MPa and 366.9 MPa at 25 °C and 160 °C, respectively. The sag of conductor of 50 m length are 95 mm, 367 mm, and 371 mm at 25 °C, 110 °C, and 160 °C, respectively. The creep strain are 271 mm/km, 522 mm/km, and 867 mm/km after 10 years under the tension of 15% RTS (Rated Tensile Strength), 25% RTS and 35% RTS at 25 °C, and 628 mm/km under 25% RTS at 160 °C, according to the test result and calculation. The carrying capacity of composite conductor is basically equivalent to ACSR (Aluminum Conductor Steel Reinforced). ACCC/HW is suitable in overhead transmission lines, and it has been used in 50 kV power grid, according to the results.

Prevention of Barite Sag in Oil-Based Drilling Fluids Using a Mixture of Barite and Ilmenite as Weighting Material

Drilling high-pressure high-temperature (HPHT) wells requires a special fluid formulation that is capable of controlling the high pressure and is stable under the high downhole temperature. Barite-weighted fluids are common for such purpose because of the good properties of barite, its low cost, and its availability. However, solids settlement is a major problem encountered with this type of fluids, especially at elevated downhole temperatures. This phenomenon is known as barite sag, and it is encountered in vertical and directional wells under static or dynamic conditions leading to serious well control issues. This study aims to evaluate the use of barite-ilmenite mixture as a weighting agent to prevent solids sag in oil-based muds at elevated temperatures. Sag test was conducted under static conditions (vertical and inclined) at 350 °F and under dynamic conditions at 120 °F to determine the optimum ilmenite concentration. Afterward, a complete evaluation of the drilling fluid was performed by monitoring density, electrical stability, rheological and viscoelastic properties, and filtration performance to study the impact of adding ilmenite on drilling fluid performance. The results of this study showed that adding ilmenite reduces sag tendency, and only 40 wt.% ilmenite (from the total weighting material) was adequate to eliminate barite sag under both static and dynamic conditions with a sag factor of around 0.51. Adding ilmenite enhanced the rheological and viscoelastic properties and the suspension of solid particles in the drilling fluid, which confirmed sag test results. Adding ilmenite slightly increased the density of the drilling fluid, with a slight decrease in the electrical stability within the acceptable range of field applications. Moreover, a minor improvement in the filtration performance of the drilling fluid and filter cake sealing properties was observed with the combined weighting agent. The findings of this study provide a practical solution to the barite sag issue in oil-based fluids using a combination of barite and ilmenite powder as a weighting agent to drill HPHT oil and gas wells safely and efficiently with such type of fluids.

A Combined Barite-Ilmenite Weighting Material to Prevent Barite Sag in Water-Based Drilling Fluid.

Barite sag is a serious problem encountered while drilling high-pressure/high-temperature (HPHT) wells. It occurs when barite particles separate from the base fluid leading to variations in drilling fluid density that may cause a serious well control issue. However, it occurs in vertical and inclined wells under both static and dynamic conditions. This study introduces a combined barite–ilmenite weighting material to prevent the barite sag problem in water-based drilling fluid. Different drilling fluid samples were prepared by adding different percentages of ilmenite (25, 50, and 75 wt.% from the total weight of the weighting agent) to the base drilling fluid (barite-weighted). Sag tendency of the drilling fluid samples was evaluated under static and dynamic conditions to determine the optimum concentration of ilmenite which was required to prevent the sag issue. A static sag test was conducted under both vertical and inclined conditions. The effect of adding ilmenite to the drilling fluid was evaluated by measuring fluid density and pH at room temperature, and rheological properties at 120 °F and 250 °F. Moreover, a filtration test was performed at 250 °F to study the impact of adding ilmenite on the drilling fluid filtration performance and sealing properties of the formed filter cake. The results of this study showed that adding ilmenite to barite-weighted drilling fluid increased fluid density and slightly reduced the pH within the acceptable pH range (9–11). Ilmenite maintained the rheology of the drilling fluid with a minimal drop in rheological properties due to the HPHT conditions, while a significant drop was observed for the base fluid (without ilmenite). Adding ilmenite to the base drilling fluid significantly reduced sag factor and 50 wt.% ilmenite was adequate to prevent solids sag in both dynamic and static conditions with sag factors of 0.33 and 0.51, respectively. Moreover, HPHT filtration results showed that adding ilmenite had no impact on filtration performance of the drilling fluid. The findings of this study show that the combined barite–ilmenite weighting material can be a good solution to prevent solids sag issues in water-based fluids; thus, drilling HPHT wells with such fluids would be safe and effective.

Enhancing the Stability of Invert Emulsion Drilling Fluid for Drilling in High-Pressure High-Temperature Conditions

Drilling in high-pressure high-temperature (HPHT) conditions is a challenging task. The drilling fluid should be designed to provide high density and stable rheological properties. Barite is the most common weighting material used to adjust the required fluid density. Barite settling, or sag, is a common issue in drilling HPHT wells. Barite sagging may cause many problems such as density variations, well-control problems, stuck pipe, downhole drilling fluid losses, or induced wellbore instability. This study assesses the effect of using a new copolymer (based on styrene and acrylic monomers) on the rheological properties and the stability of an invert emulsion drilling fluid, which can be used to drill HPHT wells. The main goal is to prevent the barite sagging issue, which is common in drilling HPHT wells. A sag test was performed under static (vertical and 45° incline) and dynamic conditions in order to evaluate the copolymer’s ability to enhance the suspension properties of the drilling fluid. In addition, the effect of this copolymer on the filtration properties was performed. The obtained results showed that adding the new copolymer with 1 lb/bbl concentration has no effect on the density and electrical stability. The sag issue was eliminated by adding 1 lb/bbl of the copolymer to the invert emulsion drilling fluid at a temperature &gt;300 °F under static and dynamic conditions. Adding the copolymer enhanced the storage modulus by 290% and the gel strength by 50%, which demonstrated the power of the new copolymer to prevent the settling of the barite particles at a higher temperature. The 1 lb/bbl copolymer’s concentration reduced the filter cake thickness by 40% at 400 °F, which indicates the prevention of barite settling at high temperature.

Testing of a sag of a dosimetry system rotating with a gantry using the interplay effect between detector motion and MLC motion

Abstract Purpose: An interplay between detector motion and MLC motion is a source of measurement error, when dose for dynamic arc is measured using a dosimetry system moving relative to the beam central axis during its rotation with a gantry. The purpose of this study is to develop and to evaluate a method of quantitative testing of a sag/flex of such dosimetry systems. Methods: The method is based on evaluation of relative differences between signals measured for two single arc beams, where a narrow slit field is sliding during gantry movement in opposite directions. The component of a measurement error related to the interplay effect was first assessed based on theoretical computer simulations and then on measurements for four dosimetry systems. The sag pattern of EPID and 2D array was extracted from the measurement results. Results: The simulations showed a 4 mm difference in field width and 3.3% difference in relative signals at beam axis between test beams where the slit field swept over 19 cm in opposite directions ( sinusoidal sag pattern with amplitude of 1 mm was assumed). The signal differences exceeding 4% and 5% were measured for EPID and 2D array, respectively. Conclusions: Even relatively small detector sag (less than 1 mm) can produce significant measurement error; therefore, the detector sag test should be an obligatory component of a validation of rotating dosimetry systems used for QA of dynamic arcs.

Effects of surgical variables in balancing of total knee replacements using an instrumented tibial trial

BackgroundIn total knee surgery, typically the bone cuts are made first to produce the correct overall alignment. This is followed by balancing, often using spacer blocks to obtain equal parallel gaps in flexion and extension. Recently an electronically instrumented tibial trial has been introduced, which measures lateral and medial contact forces. The goal of our study was to determine the effect of different surgical variables; changing component sizes, modifying bone cuts, or ligament releases; on the contact forces, as a method to achieve balancing. MethodsA special rig was designed to fit on a standard operating table, on which tests on 10 lower extremity specimens were carried out. After making bone cuts for a posterior cruciate retaining knee using a navigation system, tibial thickness was determined in extension using the Sag Test. Different Surgical Variables were then implemented, and the changes in the condylar forces were determined throughout flexion using the Heel Push Test. Resultscondylar forces were found to consist of gravity forces due to the weight of the leg plus forces due to pretension in the collateral ligaments. The pretension force averaged 145N but there was considerable variation because of ligament stiffness properties. Balancing from an imbalanced state could be achieved with adjustments within only 2° or 2mm. ConclusionThe instrumented tibial trial provided force information which indicated which surgical correction options to carry out to achieve balancing. From an initial unbalanced state, relatively small changes could produce balancing, indicating the sensitivity of the procedure. Clinical RelevanceNon-clinical. This study will assist in the balancing of the knee at total knee replacement surgery.

Experimental Investigation of the Effect of Calcium Lignosulfonate on Adsorption Phenomenon in Surfactant Alternative Gas Injection

Fractional flow analysis confirms the advantages of surfactant alternative gas injection (SAG) in enhanced oil recovery, but an adsorption phenomenon that has been affected by several factors, weakens the effectiveness of SAG injection. In this study, the effects of sacrificial agent, gas phase, and surfactant concentration on adsorption density on silica mineral were investigated by static and dynamic adsorption experiments. A series of SAG tests were performed to examine the effect of injection rates and presence of Calcium Lignosulfonate (CLS) on oil recovery. Also, variation of effluent sodium dodecyl sulfate (SDS) concentration during SAG test was examined. Spectrophotometric method based on the formation of an ion-pair was used in all experiments for determination of SDS concentration. The results of adsorption experiments show that SDS adsorption density on silica was reduced when nitrogen was imposed instead of using methane. It can be reduced with addition of CLS as sacrificial agents and amount of adsorption reduction increases as concentration increases. Flooding experiment results show that SAG injection increase ultimate recovery up to 10% in comparison with water alternative gas (WAG) injection. Increasing viscosity of gas phase and its trapping in porous media results a decrease in the mobility of gas and an increase in oil recovery. Stability of formed foam in porous media is rate-depended and higher SDS adsorption was observed at first cycle of SAG injection due to high solid/liquid interaction. Using CLS slightly increases the ultimate oil recovery, while it decreases the adsorption density of SDS about 22 percent during the SAG test.

Correlation between sagging and shear elasticity in pectin, gelatin and polyacrylamide gels

The relationship between the height of gels determined by a sag test and their elastic shear modulus ( G′) has been both investigated experimentally and simulated using a finite element analysis for the inhomogeneous deformation of gels due to gravity. It was assumed in the simulations that gels can be modeled as incompressible linear elastic materials. General relationships between the sag of gels and their elastic modulus were obtained from the simulations for slip and no-slip conditions. The relationships were tested experimentally on pectin, gelatin and polyacrylamide gels with a range of concentrations and rigidities. The good agreement between the predictions and the results shows that these gels can be modeled accurately as incompressible elastic materials. A standard 150° SAG pectin gel, which sags 23.5% in the SAG test, has G′ moduli of 429 and 379 Pa under slip and no-slip conditions, respectively.

Ｌａ２Ｏ３添加Ｍｏ板における長大結晶粒積層組織の形成と機械的性質

Molybdenum sheets (trade name: TEM) having elongated coarse-grain structures were developed. The grain structures were controlled by hot and cold rolling under high total reduction ratio (εt) and recrystallization treatment at 2070K of sintered Mo body with lmass% of La2O3.The recrystallization temperatures of La2O3-doped Mo sheets which were examined in terms of Vickers hardness and optical microstructure were higher than those of pure-Mo and TZM (Mo-0.56Ti-0.086Zr-0.016C by mass%) sheets. In particular, that of the La2O3-doped Mo sheet with high εt of 99.1 % was about 1830K, 400K higher than that of the pure-Mo sheet.The deformation resistance of TEM sheets having elongated coarse-grain structures, which was examined by sag tests at 1470K to 2070K, were superior to those of the pure-Mo and TZM sheets with equiaxial grains. In particular, deformation resistance was improved at aspect ratios (L/W) exceeding 20. Sag value of TEM sheets with L/W=150 after sag test for 36ks at 2070K was less than 1/100 that of pure-Mo sheet and less than 1/60 of TZM sheet.The shock resistance of TEM sheets with L/W=150 at room temperature, which was examined by the falling-weight impact test, was superior to that of the pure-Mo sheet with equiaxial grains.

The use of oven heat sag to determine heat resistance in polypropylenes

AbstractHeat deflection is often the only test used to determine a materials ability to withstand exposure to elevated temperatures under load. This test has its limitations, simply because not all materials operate under loads of 1820 kPa (264 psi) or 455 kPa (66 psi). Consequently, heat deflection cannot always give a true indication of a materials high temperature capabilities. The automotive industry has used the heat sag test to measure the deformation of elastomeric materials during the paint curing process. The heat sag test measures the sag of a molded bar. One end of the bar is clamped while the other end is free to sag or deflect. Samples are tested over a range of temperatures to determine the failure deflection point. This study examines the correlation of the heat sag to heat deflection and dynamic mechanical analysis (DMA) on polypropylene resins and compounds and polystyrene.

Motor-unit categorization based on contractile and histochemical properties: a glycogen depletion analysis of normal and reinnervated rat tibialis anterior muscle.

1. Isolated and glycogen-depleted motor units (MUs) have been studied in normal and reinnervated tibialis anterior (TA) muscles of the rat to examine 1) the correspondence between physiological and histochemical classifications, 2) the extent to which unit properties cluster according to type, 3) the relation between unit force and fatigability, and 4) the extent to which reinnervated MUs recover their former properties. 2. MUs were isolated by ventral root dissection and stimulation in reinnervated and normal TA muscles, 3.5-8 mo after common peroneal (CP) nerve section and resuture and in age-matched control rats, respectively. The units were characterized physiologically for classification into four types: slow twitch (S), fast twitch, fatigue resistant (FR), fast twitch fatigue intermediate (FI), and fast twitch fatigue sensitive (FF). Four muscle fiber types were identified histochemically with the use of a modification of the techniques of Brooke and Kaiser, and Guth and Samaha to delineate fiber subtypes on the basis of the pH sensitivity of myofibrillar adenosine triphosphatase (ATPase). 3. Neither the time-to-peak twitch force development nor the profile of unfused tetanus ("sag test") was unambiguous in separating fast from slow MUs. However, all units with a time to peak greater than 22 ms were fatigue resistant, and this time was chosen to delineate fast from slow. The fast unit population was further subdivided on the basis of their fatigability. There is normally a small proportion of S units (6% S) that increased to 20% after reinnervation. Although the fast population was subdivided, there was a continuous distribution of fatigue indexes in normal and reinnervated muscles with the highest number of fast units falling into the FI category. The proportions of fast units were 28% FR, 45% FI, and 21% FF in normal muscles and 29% FR, 38% FI, and 13% FF in reinnervated muscles. 4. In normal muscles, delineation of fast and slow fibers and subdivision of fast fiber types on the basis of acid and alkali stability of myofibrillar ATPase provided a histochemical classification that showed 78% correspondence with physiological classification of the same identified units. In reinnervated muscles the correspondence between physiological and histochemical classifications was reduced to 72%. 5. The normal correlation between MU fatigability and isometric force in TA muscles was not seen in reinnervated muscles that contained more FR MUs. Mean fatigue index from normal units was significantly less at 0.55 +/- 0.03 (mean +/- SE) compared with 0.68 +/- 0.03 from reinnervated units.(ABSTRACT TRUNCATED AT 400 WORDS)

Ａｌ‐Ｍｎ系合金フィン材の加熱に伴う垂下特性と組織変化

3003 alloy bare fins, the basic component for brazing application, were made with varying distribution of precipitates and amount of solution by changing homogenizing conditions and with varing strain by changing the final reduction ratio of cold rolling. These fins were submitted to a sag test, and the change in sag distance was investigated in relation to the structural change during heating. The sag is classified into two components; one is controlled by recovery and recrystallization and the other occurs in the temperature range 550-610°C without structural change after the completion of recrystallization. The former component occurs accompanied by the migration of dislocation and grain boundary. Thus, in the case where the driving force for recrystallization is small and the dragging force is large, the sag tends to be large as the recrystallization during heating continues to the elevated temperature, making the migration of dislocation and grain boundary easy. The latter component which advances without structural change is caused by creep. Therefore, when the driving force is large and the dragging force is small, grain size becomes smaller, leading to a larger sag.

A comparison of oven sag temperature and heat deflection temperature for measuring heat resistance

AbstractThe plastics industry places great emphasis on heat deflection temperature (HDT) as a measure of heat resistance when designing a plastic product. However, many manufacturers will evaluate a material's heat resistance by exposing a finished part to meximum use temperature under gravity load rather than the high loadings associated with the heat deflection test. The oven sag test is an alternate method which looks at the sag of a molded bar under gravity load. One end of the bar is clamped while the other end is free to sag. By employing a range of temperatures, the temperature at which gross sag takes place can be found. This study investigated how well the heat deflection temperature test and the oven sag test correlate to the performance of an injection molded box subjected to high temperatures using one and two phase PVC blends. The oven sag test was found to provide a more practical and more accurate measure of a material's performance under high temperatures and no external load. It is particularly well suited for evaluating two phase polymer blends.

Study on Sag Test of Hot Coiled Compressive Spring for Suspension

コイルばねのへたり試験法であるクリーム試験, 締付試験の試験方法, 条件は一定していない. その共通化をはかるためのステップとしてへたり試験の共同実験を行い次の結果を得た.へたり測定は常用点の試験前後の変化を測定するのが良い. 試験時間は96hrが適切である. 試験温度のへたりへの影響, 両試験のへたりの相関を把握した.耐へたり性を評価できる材料独自の試験法の開発が望まれているので3方法を調査した. それらはねじりクリープ法, ねじりリラクセーション法, ヒステリシスループ法であるが, ねじりクリープ法が精度も良く, ばねのへたりとも対応づけが可能である.

Sexual Aggressiveness of Male Screw-Worm Flies Measured by Effect on Female Mortality

The effect of accelerated female mortality owing to harassment by male screw-worms, Cochliomyia hominivorax (Coquerel), was utilized in a test for sexual aggressiveness (SAG test) of males based on female mortality resulting from males present at a 3:1 ratio. Strains mating well in the SAG test also mated well in competitive tests, but inferior males mated effectively in the absence of competition. Data from earlier tests in which flies were held in a 1:1 male-female ratio after irradiation were re-examined. Apparently because of relief from harassment by males, female mortality was reduced and treated females lived as long as untreated. Fallacy of longevity data as an index of sexual vigor was demonstrated in SAG tests in which some inactive males lived as long as sexually aggressive males. The SAG test showed greatly reduced male activity as the radiation dose increased from 3 to 12 kr for 5-day-old pupae; however, for 6- and 7-day pupae only minor reductions occurred. Both Florida (Fla) and yellow eye (y) mutant males effectively reduced y female longevity, but y males were ineffective against Fla females. Males from both strains mated twice as many y as Fla females when an abundance of females of both strains was present.