Use Of Field Tests Research Articles

Experimental studies of the air conditioning system efficiency in the cab of “TORUM 785” combine harvester

The article presents the results of field tests and experimental studies of the efficiency of the climatic air conditioning system (ACS) in the cab of a combine harvester “TORUM 785”. The studies were carried out according to the Russian methods recommended for use in field tests of tractors and self-propelled vehicles intended for agricultural work in the southern regions of Russia. In the course of the research, a sufficiently high efficiency of the climatic SCR of the cabin of the “TORUM 785” combine harvester was shown under various operating conditions. It is shown that the created climatic SCRs are not inferior to foreign models developed by such companies as John Deere, Claas and New Holland.

A Method to Promote the Development of Intelligence and Game Skills in Youth Football

Research purpose. The aim of the study is to evaluate the playing skills of the young players under investigation in a global context. Specifically, it is intended to test whether the proposed training methodology favorably influenced the development of game skills, increasing the efficiency of game performance.
 Materials and methods. The study participants are 24 young players, aged between 13 and 14. To achieve the tasks set, the study relied on the following methods: analysis of scientific literature, field testing and methods of mathematical statistics. The experimental group performed a specific training mesocycle (that of the Brain Kinetic), while the control group performed a traditional working mesocycle. To detect the effects of the training methodologies, field tests were used both before and after the training period, respecting the execution protocols described by H. Wein. The study materials were processed by the statistical analysis software-IBM SPSS 22. A paired sample t-test was used to compare the results of the two groups.
 Results. The t-test analysis indicates statistically significant changes in the training effect of the experimental group. A better performance index found in the experimental group in the execution of skills, compared to the control group, is due to the diversification of the methodology to which they were subjected. Therefore, the changes after training at each skill index are amplified by the subsequent repetition of the tests. Differences between test indicators are statistically significant (p = 0.25)
 Conclusions. The study, through the use of field tests, has confirmed the hypothesis that the use of the Brain Kinetic training method determines a positive training effect in skill exercises. This method allowed the players involved in the experimental group to take personal, individual and group actions that had a real impact on the outcome of the game.

An individual approach to monitoring locomotive training load in English Premier League academy soccer players

To account for the individual intensity of locomotion tasks, individualised speed thresholds have been proposed as an alternative to global speed thresholds. Methodologies to determine individual speed thresholds have typically been laboratory based, time consuming and expensive, rendering them inappropriate for applied practitioners working with large squads. The current investigation utilised easy-to-administer field tests to individualise speed thresholds. The aim was to investigate differences between high-speed locomotion measured using global and individual speed thresholds. Nineteen, male, professional soccer players completed maximum sprint and maximum aerobic speed protocols and were divided into groups dependent upon maximum aerobic speed performance (high, medium and low). Locomotion data were collected using portable Global Positioning System units and analysed using global and individual analysis methods to determine distances travelled performing high-speed running, very high-speed running and sprinting. In low athletes, the individual analysis method produced significantly higher percentages of high-speed running, very high-speed running and sprinting compared to global (mean differences 7.8%, 6.1% and 1.7%, respectively, all p < 0.001). In medium athletes, no significant differences were found between analysis methods for high-speed running and very high-speed running. In high athletes, the individual analysis method produced significantly lower high-speed running and very high-speed running percentages compared to global (mean differences 11.0% and 6.8%, p < 0.001). Results concluded that global thresholds produced high-speed locomotion percentages significantly higher or lower than individual thresholds for 47% of athletes. The current investigation recommends the use of field tests to individualise speed thresholds, allowing applied practitioners to accurately quantify individual athlete intensity.

Determining Bilateral Strength Imbalances in Youth Basketball Athletes

The aims of this study were: 1) to compare the strongest (D) and weakest (ND) limbs in determining muscle strength asymmetry (MSA) ratios among various muscle strength qualities and 2) to determine the relationships among various muscle strength qualities. 17 youth male basketball athletes (age=17.5±0.8 years; height=187.1±9.4 cm; body mass=81.4±10.1 kg) participated in this study. Knee flexor and extensor strength at 60°·s-1 was assessed for both limbs with the use of isokinetic dynamometry. Other tests involved single-leg hop (SLH), countermovement jump (CMJ) and isometric mid-thigh pull (IMTP). Statistically significant differences (p<0.05; d=0.40-0.98) were found between D and ND limbs for all strength measures. Imbalance ratio of the IMTP was significantly related to those of SLH (r=0.75, p=0.01) whereas no significant relationships between D:ND ratios were found from all other tests. Percentage agreements of MSA ranged from 64.7-88.2% between muscle strength qualities. The findings provide support for the use of field tests to detect lower-limb strength imbalances. Future research should examine the effect of different asymmetry thresholds on percentage agreements to diagnose MSA and determine its relationship to athletic performance.

Drag on hydroid-fouled nets — An experimental approach

The present study investigated the drag increase on aquaculture nets due to biofouling of the colonial hydroid Ectopleura larynx. It had two main parts: firstly the growth characteristics of E. larynx were investigated by use of field tests at a Norwegian aquaculture site; secondly the hydrodynamic drag on the fouled twines was studied in a towing tank by using fabricated models of net twines with artificial hydroid fouling. In the field tests, the growth of the hydroids was first measured after three weeks of immersion and then again after six weeks. During this interval, the density of hydroids and the thickness of the hydroid stem were almost constant (1.4 hydroids/mm and 0.29 mm, respectively), while the average length of the hydroids increased from 6.4 to 11.2 mm. The hydroid length followed a Rayleigh distribution, while the thickness was normal (Gaussian) distributed. Replicas of twines with three different levels of hydroid growth were made (1.5 hydroids/mm twine, hydroid length 9 mm, 16 mm and 20 mm), and the drag on these twines was measured at different towing velocities (0.1 to 1.4 m/s) and with different twine configurations. For the twine with the shortest hydroids (9 mm), the drag was from 1.5 times (Re=4000) to 2.2 times (Re=1000) the drag on a clean twine. For the longest hydroids (21 mm), the drag was 2 times and 3.8 times, respectively.

Assessing Wear Performance of Two High-carbon Hadfield Steels Through Field Tests in the Mining Industry

Hadfield steels are widely used in the production of liners for rock crushing applications due to their good wear resistance and high toughness. Because of the high replacement frequency and cost of these liners, improvements in the properties of Hadfield steels may represent a great economic benefit for mining operators. Therefore, correctly assessing wear performance is a relevant matter in the research and development activities regarding Hadfield steels. However, conventional laboratory tests may not accurately mimic the conditions of impact and gouging abrasion occurring in crushing applications. Field tests may represent a complementary source of information particularly useful in the optimization of Hadfield steels. In this work, the wear performance of two Hadfield steels was investigated through field testing. Their characteristics included high carbon content and two different levels of manganese content. Two sites were chosen for the assessment: a pebble crushing plant and an aggregate plant. The first site presented very hard material and compression crushing conditions, whereas the second site presented impact crushing conditions. The use of field tests allowed comparing wear ratios between both steels and it also permitted to identify critical issues constraining steels performance, such as microstructure embrittlement. Despite some limitations, the results from the field tests demonstrated that better wear performance was associated with higher manganese content.

Selective Detection of Hazardous Indoor VOCs Using Metal Oxide Gas Sensors

A strategy for detecting and identifying trace levels of hazardous volatile organic compounds (VOCs) in indoor air is presented. A metal oxide semiconductor gas sensor in temperature cycled operation is used to detect formaldehyde, benzene and naphthalene in ppb and sub-ppb concentrations with a varying background of ethanol with concentrations of up to 2ppm. Measurement results from a laboratory device have been compared with an integrated sensor system designed for use in field tests. We found that gas emissions from the system itself are an important issue. The emissions have been identified and quantified using analytical methods in order to derive design rules for a proper field test system. However, the results show that selective detection of VOCs in the ppb range is possible even with an intensive background of various VOCs, although sensitivity is reduced compared to the ideal laboratory case.

A Comparison of Isokinetic and Functional Methods of Assessing Bilateral Strength Imbalance

Muscle strength imbalances have been linked with poor agility performance and higher injury risk. Isokinetic dynamometry has been used to investigate such imbalances; however, this method is impractical and inaccessible for most strength and conditioning coaches. The aim of the study was to compare isokinetic dynamometry with functional field tests for assessing bilateral strength imbalance. Thirteen male athletes from various sports (mean+/-SD: age 21+/-1.1 years, height 179.8+/-7.0 cm, body mass 80.8+/-9.7 kg) participated in the study. Knee flexor and extensor strength at 60 degrees.s(-1) was assessed for both limbs with the use of isokinetic dynamometry. Field tests involved seated unilateral leg press, horizontal hop, single-leg vertical and drop jumps. Significant differences (p<0.01) were found when comparing strength dominant (D) and nondominant (ND) limbs for all strength measures, ranging from 4.5% (hop test) to 12.4% (eccentric extension). No significant differences between the right and left limbs were found (p>0.05). No significant relationships between strength D/ND ratios of isokinetic variables and the field tests were evident (p>0.05). The findings provide support for the use of field tests to detect imbalances between lower limbs, but the ultimate choice of test used should depend on the specific strength quality that predominates in the sport.

Freeze-Thaw Performance of Concrete: Reconciling Laboratory-Based Specifications with Field Experience

Abstract Specifications relating to frost resistance of concrete are generally based on laboratory tests of laboratory-produced concrete. Quality control for laboratory-produced concrete is usually significantly better than what can be achieved in the field, and laboratory freeze-thaw tests generally produce conditions that are not close to any real field exposure conditions. Field exposure testing is also problematic. Exposure conditions are not the same from one location to the next and may not even be the same from one year to the next at the same location. This paper attempts to provide guidance for interpreting the results of field tests of concrete exposed to natural freezing and thawing conditions. Types of frost damage as well as types of field test sites are discussed, and recommendations are provided for the use of field test results to modify frost-resistance specifications.

Measurement of EMG activity with textile electrodes embedded into clothing

Novel textile electrodes that can be embedded into sports clothing to measure averaged rectified electromyography (EMG) have been developed for easy use in field tests and in clinical settings. The purpose of this study was to evaluate the validity, reliability and feasibility of this new product to measure averaged rectified EMG. The validity was tested by comparing the signals from bipolar textile electrodes (42 cm2) and traditional bipolar surface electrodes (1.32 cm2) during bilateral isometric knee extension exercise with two electrode locations (A: both electrodes located in the same place, B: traditional electrodes placed on the individual muscles according to SENIAM, n = 10 persons for each). Within-session repeatability (the coefficient of variation CV%, n = 10) was calculated from five repetitions of 60% maximum voluntary contraction (MVC). The day-to-day repeatability (n = 8) was assessed by measuring three different isometric force levels on five consecutive days. The feasibility of the textile electrodes in field conditions was assessed during a maximal treadmill test (n = 28). Bland–Altman plots showed a good agreement within 2SD between the textile and traditional electrodes, demonstrating that the textile electrodes provide similar information on the EMG signal amplitude to the traditional electrodes. The within-session CV ranged from 13% to 21% in both the textile and traditional electrodes. The day-to-day CV was smaller, ranging from 4% to 11% for the textile electrodes. A similar relationship (r2 = 0.5) was found between muscle strength and the EMG of traditional and textile electrodes. The feasibility study showed that the textile electrode technique can potentially make EMG measurements very easy in field conditions. This study indicates that textile electrodes embedded into shorts is a valid and feasible method for assessing the average rectified value of EMG.

Measuring physician job satisfaction in a changing workplace and a challenging environment. SGIM Career Satisfaction Study Group. Society of General Internal Medicine.

Changes in the demographic, specialty, and employment sector composition of medicine have altered physicians' jobs, limiting autonomy and reducing morale. Because physician job satisfaction has been linked to clinical variables, better measurement might help to ameliorate conditions linked to medical disaffection, possibly improving health care. To document conceptual development, item construction, and use of content experts in designing multidimensional measures of physician job satisfaction and global satisfaction scales for assessing physicians' job perceptions across settings and specialties. Using previous research, physician focus groups, secondary analysis of survey data, interviews with physician informants, and a multispecialty physician expert panel, distinct job facets and statements representing those facets were developed. Facets from previously validated instruments included autonomy, relationships with colleagues, relationships with patients, relationships with staff, pay, resources, and status. New facets included intrinsic satisfaction, free time away from work, administrative support, and community involvement. Physician status items were reconfigured into relationships with peers, patients, staff, and community, yielding 10 hypothetical facets. Global scales and items were developed representing satisfaction with job, career, and specialty. A comprehensive approach to assessing physician job satisfaction yielded 10 facets, some of which had not been previously identified, and generated a matching pool of items for subsequent use in field tests.

Condition Data and Bridge Management Systems

Automated systems for maintenance management of bridges require information on current and future needs for maintenance and repair actions. Often, this information is provided indirectly by condition ratings for bridge elements. This paper presents new condition states defined as stages of service life, notes the correspondence between new states and present-day condition ratings in US practice, outlines the use of field testing to identify condition states, reviews deterioration modeling for condition states, and notes a procedure for segmental inspection to capture quantities and locations of conditions.

Optimizing techniques for field testing of buildings

As national building codes and acoustic comfort standards become more common as tools for quantifying and promoting acoustical quality in dwellings there is a greater need for field testing of buildings. The intent of this project is the promotion of a greater use of field testing by providing more convenient measurement methods. Primarily the focus has been on identifying the ideal sound source. Explosive sources using charges produced for use in powder powered tools have emerged as satisfying the majority of our needs. Continuing study is aimed at optimizing such a source. In particular, it needs to produce adequate power for measuring at the low frequencies required for implementing the new spectrum adaptation terms for the traditional single-figure ratings of building insulation.

Spontaneous change of a benign satellite RNA of cucumber mosaic virus to a pathogenic variant.

Plant satellite RNAs generally reduce the level of helper virus accumulation and attenuate the disease symptoms induced by the helper virus that they depend upon for replication and packaging. As such, satellite RNAs could be used as biocontrol agents to reduce the level of disease in field crops, either by the application of a viral vaccine to healthy plants, or by the transgenic expression of satellite RNA in transformed plants. One such virus/satellite RNA system already under use in field tests is cucumber mosaic virus (CMV) and its satellite RNAs. However, in this system, some satellite RNAs also intensify viral disease in particular host plants. We passaged a satellite RNA of CMV with its helper virus to determine whether a satellite RNA that attenuates CMV-induced disease on tobacco plants could mutate to a pathogenic form, which might then be selected. In several experiments involving strains of CMV from each of the two subgroups, the satellite rapidly mutated to a pathogenic form, which was selected. This demonstrates an inherent risk associated with the use of attenuating satellite RNAs as a form of biocontrol of CMV.

Measuring water-holding capacity in pork musculature with a tensiometer

The water-holding capacity (WHC) of post-mortem porcine musculature is an important quality trait, and it is desirable for the industry to assess its variations ,for purposes of evaluating and processing pork products. There are several procedures to accurately determine WHC, but most are either too slow, too expensive or are impractical for commercial application. Since WHC is also important when examining the characteristics of soil, scientists routinely use an instrument called a tensiometer for this measurement. Therefore, we explored the potential application of this technique for assessing WHC in post-rigor pork muscle. The cost, potential speed and invasive application of the tensiometer in muscle were attractive characteristics. A sample (29) of pork loins, representing considerable variation in WHC were used to test the applicability of a commercial tensiometer. When tensiometer measurements were compared to 48 h drip loss, the results indicated the tensiometer could accurately detect the variations in free fluids expressed in muscle and that the procedure could be applied quickly and invasively without altering the commercial value of the product. However, particles (primarily protein and fat) in the muscle fluid became imbedded in the pores of the tensiometer ceramic tip, thus impairing the repeated use of the instrument. A plastic filter was developed to prevent clogging, but it could not be molded adequately to permit rapid insertion and removal for on-line measurements of WHC. Therefore, despite the various desirable features of the tensiometer, it failed to meet some requirements considered essential for further testing as a potential commercial, on-line procedure. First, the clogging problem must be resolved The study also indicated that the filter paper test would be more appropriate than the tensiometer for use in field tests to predict WHC when limited numbers of samples were to be tested.

Field response of the pine sawflyNeodiprion sertifer to controlled release of diprionyl acetate, diprionyl propionate andtrans-perillenal

Two dispenser types for pine sawfly (Hymenoptera: Diprionidae) pheromones-glass capillaries and dental cotton rolls-are described, and release rates reported. Glass capillaries of different diameters were used in field tests to determine dose-response relationships of (2S,3S,7S)-3,7-dimethylpentadecan-2-yl acetate (diprionyl acetate), diprionyl propionate, andtrans-perillenal on the trap catch of maleNeodiprion sertifer. A linear relationship between the logarithm of the capillary cross-sectional area and the logarithm of the release rate was found. However, capillaries of the same diameter could vary in the amount released by as much as a factor of 10. Both the acetate and propionate were attractive alone, but no synergistic effect was found.trans-Perillenal did not show any behavioral activity. Dental cotton rolls have been used extensively in diprionid pheromone research without knowledge about release rates. The release rate from rolls loaded with different amounts of diprionyl acetate was determined by extracting rolls after different times under constant temperature and wind conditions or after use in field tests. Quantification of diprionyl acetate was done on GC. The release rate was found to be proportional to the amount applied over several orders of magnitude, and persisted for several weeks. Capillaries and rolls with similar release rates caught similar numbers of sawflies.

Field tests for ferrous iron and ferric-organic complexes (on exchange sites or in water-soluble forms) in soils

A 1 M solution of ammonium acetate containing �, �-dipyridyl indicator is recommended for use in field tests for exchangeable and water-soluble ferrous iron in soils. In using the test, a soil sample may be added to a vial containing the solution, or the solution can be sprayed on to a freshly exposed soil face. A field test for ferric-organic complexes in soils, using the same vials, is proposed. This is based on the photochemical nature of the reduction of ferric to ferrous iron in the presence of oxidizable organic ligands. Two subsamples of soil are added to separate vials, and light is excluded from one. After 5-15 min, a positive test for ferrous iron in the vial exposed to light, and a negative test in the other, indicates the presence of ferric-organic complexes.

Use of field tests in the modeling of a liquid—liquid extraction column

The use of the results of a series of field tests in the modeling of a packed liquid—liquid extraction column is demonstrated. In the models developed the kerosene—sulfur dioxide system may be represented either by a pseudo ternary or a multicomponent mixture. The parameters determined from the field tests consisted of the number of mass transfer sections or plates and component efficiency factors. Also, a rapid and stable calculational procedure, based on the θ-method of convergence, for solving liquid—liquid extraction problems is presented.

Modeling of packed absorbers at unsteady state operation—IV

The use of field tests in the modeling of a packed absorber at unsteady state operation is demonstrated. Calculational procedures developed for this purpose are presented and demonstrated by means of numerical results.

Work of Carrying Loads

Transportation of loads is one of the commonest activities of men. In spite of this, the literature indicates that load carrying has received little scientific study. The measures generally used to indicate load carrying efficiency have been pulse rate, oxygen consumption and calories expended per distance or per unit time. A recent innovation has been the use of field tests which measure the time required for S to carry a load over a prescribed course. Although physiological indicators taken with S walking on a treadmill provide wellcontrolled data, field studies give a more realistic estimate of the effect of various loadings. The optimum load weight has been found to be approximately 35% of body weighc: the optimum rate of carry, 85-95 yd/min. Faster rates of carrying result in greater energy expenditure than do increasing weights of loads up to 41% of body weight. The best position is the one which least affects the carrier's balance and center of gravity. This will vary with the weight of the load; high positions are better for loads under 46 Ib., low positions better for heavier loads. The shape of the load affects both the balance and the center of gravity of the carrier. Clothing, physical condition of the Ss and training in specific techniques of carrying are all influential in determining the efficiency of load carrying and should be controlled in future experiments. Further study is needed to clarify the differences obtained berween physiological measures of ef6ciency and subjective preferences for daerenc types of loads. Finally, it is suggested that studies be made to determine the effect of load carrying on performance after carrying the loads. In practical situations it is often as important to obtain near optimum performance from the man after he has put the load down as it is to improve the efficiency of the load carrying performance itself.