Half-time and high-speed running in the second half of soccer

This study investigated if the quantity of high-speed running (movements >15 km.h-1) completed in the first 15 minutes of competitive football matches differed from that completed in the corresponding 15 minutes of the second half. Twenty semi-professional soccer players (age 21.2 ± 3.6 years, body mass 76.4 ± 3.8 kg, height 1.89 ± 0.05 m) participated in the study. Fifty competitive soccer matches and 192 data files were analysed (4 ± 2 files per match) using Global Positioning Satellite technology. Data were analysed using 2-way repeated measures ANOVA and Pearson correlations. No differences were found between the first 15 min of each half for the distance completed at high-speed (>15 km.h-1) or sprinting (>21 km.h-1), or in the number of sprints undertaken (p>0.05). However, total distance covered was shorter (1st half vs. 2nd half: 1746 ± 220 vs. 1644 ± 224 m; p<0.001) and mean speed lower (1st half vs. 2nd half: 7.0 ± 0.9 vs. 6.6 ± 0.9 km.h-1; p<0.001) in the first 15 min of the second half compared to the first. The correlations between the duration of the half-time interval and the difference in the high-speed running or sprinting between first and second halves (0-15 min) were very small (r=0.08 [p=0.25] and r=0.04 [p=0.61] respectively). Therefore, this study did not find any difference between the amount of high-speed running and sprinting completed by semi-professional soccer players when the first 15 minutes of the first and second half of competitive matches were compared The maintenance of high-speed running and sprinting, as total distance and mean speed declined, may be a function of the pacing strategies adopted by players in competitive matches

Recent Legal Literature

Clementson: A Manual Reletaing to Special Verdicts and Special Findings; Wharton: A Treatise on the conflict of Laws, or Private International Law; Lile, Redfield, Wambaugh and Wheeler: Brief Making and the Use of Law Books; Pomroy: Pomroy: Pomeroy\u27s Equitable Remedies (supplementary to Pomeroy\u27s Equity Jurisprudence); McLaughlin: The Confederation and the Constitution, 1783-178

Thin-Filament Pyrometry Developed for Measuring Temperatures in Flames

Many valuable advances in combustion science have come from observations of microgravity flames. This research is contributing to the improved efficiency and reduced emissions of practical combustors and is benefiting terrestrial and spacecraft fire safety. Unfortunately, difficulties associated with microgravity have prevented many types of measurements in microgravity flames. In particular, temperature measurements in flames are extremely important but have been limited in microgravity. A novel method of measuring temperatures in microgravity flames is being developed in-house at the National Center for Microgravity Research and the NASA Glenn Research Center and is described here. Called thin-filament pyrometry, it involves using a camera to determine the local gas temperature from the intensity of inserted fibers glowing in a flame. It is demonstrated here to provide accurate measurements of gas temperatures in a flame simultaneously at many locations. The experiment is shown. The flame is a laminar gas jet diffusion flame fueled by methane (CH4) flowing from a 14-mm round burner at a pressure of 1 atm. A coflowing stream of air is used to prevent flame flicker. Nine glowing fibers are visible. These fibers are made of silicon carbide (SiC) and have a diameter of 15 m (for comparison, the average human hair is 75 m in diameter). Because the fibers are so thin, they do little to disturb the flame and their temperature remains close to that of the local gas. The flame and glowing filaments were imaged with a digital black-and-white video camera. This camera has an imaging area of 1000 by 1000 pixels and a wide dynamic range of 12 bits. The resolution of the camera and optics was 0.1 mm. Optical filters were placed in front of the camera to limit incoming light to 750, 850, 950, and 1050 nm. Temperatures were measured in the same flame in the absence of fibers using 50-m Btype thermocouples. These thermocouples provide very accurate temperatures, but they generally are not useful in microgravity tests because they measure temperature at only one location at a time. Thermocouple measurements at a height of 11 mm above the burner were used to calibrate the thin-filament pyrometry system at all four wavelengths. This calibration was used to perform thin-filament pyrometry at other heights above the burner. One such profile is shown in this graph; this is for a height of 21 mm. The agreement between the pyrometry measurements and thermocouple results at this height is excellent in the range of 1000 to 2000 K, with an estimated uncertainty of 50 K and an estimated upper limit of 2500 K. Neither the thermocouple nor the thin-filament pyrometry temperatures have been corrected for radiation, but the correction is expected to be nearly the same for both methods. We anticipate that thin-filament pyrometry similar to that developed here will become an important diagnostic for studies of microgravity flames owing to its accuracy and its ability to simultaneously measure finely spaced temperatures

Note and Comment

What is the Practice of Medicine?; The Extent of the Land to Which a Mechanics\u27 Lien Attaches; May a Murderer Acquire Property From His victim by Descent or Devise?; One Way to Prevent Some of the Law\u27s Delays

Viability of Various Ignition Sources to Ignite A2L Refrigerant Leaks

An international drive toward sustainability of refrigeration systems will require the adoption of low global warming potential (GWP) refrigerants. Most of these are mildly flammable. Low-GWP refrigerants are generally well characterized in terms of their lower flammability limits, heats of combustion, and flame speeds. However, they are poorly understood in terms of their susceptibility to ignition from sources commonly encountered in residential and industrial settings, including motors, electric arcs, hot surfaces, and open flames. This important gap in understanding is the focus of this project. The primary objective of this project was to perform tests to determine the viability of various ignition sources to ignite A2L refrigerants in air. Fifteen ignition sources were identified and tested. The A2L refrigerants tested were R-32, R-452B, R-1234yf, and R-1234ze. The tests were performed in a windowed stainless steel chamber with dimensions of 0.3 × 0.3 × 0.3 m and a volume of 27 L. Four of the ignition sources resulted in deflagrations or localized flames in the refrigerant-air mixtures. These were: hot wire (800 °C), safety match, lighter flame insertion, and leak impinging on candle, in order of decreasing ignition viability. Among the 15 potential ignition sources, it is remarkable that 11 were unable to ignite any of the mixtures considered here. These were: cigarette insertion, barbeque lighter, plug and receptacle, light switch, hand mixer, cordless drill, friction sparks, hair dryer, toaster, hot plate insertion, and space heater insertion. The inability of so many ignition sources to ignite A2L refrigerants is attributed here to the very long quenching distances of these refrigerants when mixed with air. Another remarkable finding is that these A2L refrigerants can act as either fuels or suppressants. For example, smoldering cigarettes were extinguished every time they encountered a stoichiometric mixture of A2L refrigerant and air

Soot Formation in Hydrocarbon/Air Laminar Jet Diffusion Flames

Soot processes within hydrocarbon/air diffusion flames are important because they affect the durability and performance of propulsion systems, the hazards of unwanted fires, the pollutant and particulate emissions from combustion processes, and the potential for developing computational combustion. Motivated by these observations, this investigation involved an experimental study of the structure and soot properties of round laminar jet diffusion flames, seeking an improved understanding of soot formation (growth and nucleation) within diffusion flames. The present study extends earlier work in this laboratory concerning laminar smoke points (l) and soot formation in acetylene/air laminar jet diffusion flames (2), emphasizing soot formation in hydrocarbon/air laminar jet diffusion flames for fuels other than acetylene. In the flame system, acetylene is the dominant gas species in the soot formation region and both nucleation and growth were successfully attributed to first-order reactions of acetylene, with nucleation exhibiting an activation energy of 32 kcal/gmol while growth involved negligible activation energy and a collision efficiency of O.53%. In addition, soot growth in the acetylene diffusion flames was comparable to new soot in premixed flame (which also has been attributed to first-order acetylene reactions). In view of this status, a major issue is the nature of soot formation processes in diffusion flame involving hydrocarbon fuels other than acetylene. In particular, information is needed about th dominant gas species in the soot formation region and the impact of gas species other than acetylene on soot nucleation and growth

A questionnaire study of injections prescribed and dispensed for patients diagnosed with mild/moderate community-acquired pneumonia in Mongolia

Purpose. The study aimed to determine the extent of and factors influencing the prescribing of injections for the treatment of mild/moderate community acquired pneumonia (CAP) in Mongolia. Methods. Questionnaires were developed and administered to medication providers (34 Pharmacists, 27 pharmacy technicians) and prescribers (22 general doctors and 49 medical specialists) working in Mongolia. Results. Cefalosporins were prescribed for patients with mild pneumonia and doctors tended to prescribe injectable cefalosporins (cefazolin) rather than oral dosage forms. This was supported by the questionnaire study with pharmacists and pharmacy technicians. Additionally, 23 pharmacists and pharmacy technicians indicated that OTC injectable cefalosporins (37.7%) and injectable aminopenicillins (33,9%) were frequently sold by pharmacies for the treatment of mild/moderate CAP. Doctors and particularly pharmacists in the questionnaire studies indicated choosing an injection was to avoid non-compliance problems. Conclusion. High levels of injectable prescribing of antibiotics were found in non-hospitalized patients with CAP in Mongolia. This prevalence level indicated that inappropriate injection prescribing is a public health hazard for Mongolia and requires consideration by the appropriate authorities

Service learning with First Peoples: a framework to support respectful and reciprocal learning

This article outlines a framework for working with First Peoples. The framework supports respectful and mutually beneficial learning partnerships and culminates from 6 years of practice and research in arts-based service learning with Aboriginal communities in Australia. We begin by looking at synergies between global service learning and service learning with First Peoples. We then position this work within an international context, focusing on Indigenous frameworks for practice identified in service learning with First Nations communities in North America. We next describe the Australian context and touch on the multilayered intercultural processes and outcomes associated with the programmes across three universities. Finally, we introduce the framework and elaborate on its dimensions

Higher education service learning with First Peoples of Australia

Australian higher education institutions face increasing pressure to institute Aboriginal and Torres Strait Islander culture at every level of activity. In this paper, which takes as its context a three-university service-learning initiative with First Peoples of Australia, we argue that service-learning opportunities develop students who are more culturally responsive, adaptable and aware. In this instance we position service learning as a strategy through which Australian universities and colleges might promote Indigenous cultural content for students, faculty and the broader community. We report the experiences of a funded, arts-based service learning initiative in which creative arts students (n=70) and pre-service teachers (n=37) worked with over 290 Aboriginal community members in urban, rural and remote areas of Australia. The study adopted an action research approach and we combined a range of conceptual-theoretical resources with the voices and experiences of the students, academic researchers and community members. Our study data confirmed the potential for service learning to build valuable intercultural competencies amongst higher education students, fostering critical engagement with racial politics and a shift in extant views of cultural diversity. Participating students developed a deeper awareness of their past experiences and a greater sensitivity towards forms of social and cultural oppression. Deeper critical engagement with the issues faced by Aboriginal and Torres Strait Islander communities prompted students to be more responsive in their critiques of the cultural politics of their own educational experiences. As they gained confidence and self-assuredness, students learned to dra

Smoke Point in Co-flow Experiment

The Smoke Point In Co-flow Experiment (SPICE) determines the point at which gas-jet flames (similar to a butane-lighter flame) begin to emit soot (dark carbonaceous particulate formed inside the flame) in microgravity. Studying a soot emitting flame is important in understanding the ability of fires to spread and in control of soot in practical combustion systems space. Previous experiments show that soot dominates the heat emitted from flames in normal gravity and microgravity fires. Control of this heat emission is critical for prevention of the spread of fires on Earth and in space for the design of efficient combustion systems (jet engines and power generation boilers). The onset of soot emission from small gas jet flames (similar to a butane-lighter flame) will be studied to provide a database that can be used to assess the interaction between fuel chemistry and flow conditions on soot formation. These results will be used to support combustion theories and to assess fire behavior in microgravity. The Smoke Point In Co-flow Experiment (SPICE) will lead to a o improved design of practical combustors through improved control of soot formation; o improved understanding of and ability to predict heat release, soot production and emission in microgravity fires; o improved flammability criteria for selection of materials for use in the next generation of spacecraft. The Smoke Point In Co-flow Experiment (SPICE) will continue the study of fundamental phenomena related to understanding the mechanisms controlling the stability and extinction of jet diffusion flames begun with the Laminar Soot Processes (LSP) on STS-94. SPICE will stabilize an enclosed laminar flame in a co-flowing oxidizer, measure the overall flame shape to validate the theoretical and numerical predictions, measure the flame stabilization heights, and measure the temperature field to verify flame structure predictions. SPICE will determine the laminar smoke point properties of non-buoyant jet diffusion flames (i.e., the properties of the largest laminar jet diffusion flames that do not emit soot) for several fuels under different nozzle diameter/co-flow velocity configurations. Luminous flame shape measurements would also be made to verify models of the flame shapes under co-flow conditions. The smoke point is a simple measurement that has been found useful to study the influence of flow and fuel properties on the sooting propensity of flames. This information would help support current understanding of soot processes in laminar flames and by analogy in turbulent flames of practical interest