bluuebunny/crossref_metadata_2025 huggingface dataset:
A Concept for Remote Sensing Data Selection and Method Selection
Authors: Fung KB , Robson MA
Published: March 2009

Analysis of remote sensing imagery in the past has consisted of processing a single image from a single sensor. Capabilities now exist to use more than one data source in a single interpretation (such as multi-sensor integration, multi-temporal analysis, interpretations of combined raster-vector overlays). As more data sources become available, data sets become more pluralized, creating two key challenges in the related analysis. The first challenge is to integrate and manage the physical data and metadata as individual data sources and as compound datasets. The second challenge is to select data subsets and related analysis methodologies which are best suited to solve given problems. It is obvious that a dataset consisting of both an optical image and a microwave image will require different analysis methods for each subset, to meet similar goals. In the less extreme case of a dataset containing both spaceborne and airborne optical images, different methods would apply due to their different resolutions and spectral properties.

Current and potential operational users could have very high demands for remote sensing data if they were provided with appropriate interpretation tools. These users would not be interested in the process of choosing analysis methods for their data, they would be more concerned with which method was actually used, and its result compared to the specified input criteria. Ultimately they would not be concerned with even choosing the data, but rather would provide a goal of their desired result for driving the decision of which data to select.

In this paper, a technique is presented for addressing high-level criteria for analyzing remote sensing data. The technique consists of selecting methods most likely to achieve the result from among several known candidates.
Conceptualization and Characterization of Ground-Water Systems Using Geographic Information Systems
Authors: Kolm KE
Published: March 2009

The correlation and synthesis of a variety of two- and three-dimensional data is necessary to conceptualize and characterize ground-water flow systems in regional or site-specific areas. This paper presents an integrated, multidisciplinary, step-wise approach for conceptualizing, characterizing, and numerically simulating ground-water flow systems using Geographic Information Systems (GIS).

The method presented involves seven iterative steps that can be accomplished manually or by using GIS: 1) Data gathering and preparation; 2) Field (on-site) conceptualization; 3) Surface characterization; 4) Subsurface characterization; 5) Hydrogeologic model characterization; 6) Hydrologic system characterization; and 7) Numerical model simulation. GIS may be used for: 1) data management, analysis, and visualization; 2) the integration of diverse data sources; 3) rapid development, visualization, and testing of alternative hydrogeologic and hydrologic system models; 4) the incorporation of contouring, attribute tables, and statistical analysis during data analysis and model development; and 5) the integration of basic and interpreted data bases with numerical modeling for purposes of model design, parameter discretization, statistical evaluation, and sensitivity analysis.
Effect of Moisture on E-Glass/Epoxy Interfacial and Fiber Strengths
Authors: Schultheisz CR , McDonough WG , Kondagunta S , Schutte CL , Macturk KS , McAuliffe M , Hunston DL
Published: March 2009

The effect of absorbed moisture on the fiber and interfacial strengths of an epoxy reinforced with continuous fibers of E-glass has been investigated. Single-fiber fragmentation tests of E-glass/epoxy model composites have shown degradation of both the strength of the fiber and the strength of the interface after immersion in water at 25 and 75°C. This work has expanded to investigate the effects of water on the tensile and interlaminar properties of full-scale composite materials after immersion in water for comparison with the results from the single-fiber fragmentation test. One goal of this research is an assessment of the ability to predict composite structural properties from a small-scale test such as the single fiber fragmentation test; of particular interest is the possibility that the smaller scale of the test coupled with full immersion and elevated temperatures can provide an accelerated test for composite structures subjected to longer exposure under less severe environmental conditions. Four different composite test methods have been chosen to emphasize different aspects of the problem: tension tests of unidirectional layups should reflect the degradation of the fiber strength, while testing unidirectional layups in compression and in Mode I and Mode II delamination fracture should be more indicative of the degradation of the interface. Two different fiber coatings have been used in an effort to vary the nature of the glass/epoxy interface, and the specimens have been immersed at both 25 and 75°C to investigate the influence of temperature.
Previous Skiing Injuries in Alpine Olympic Racers
Authors: Ekeland A , Nordsletten L , Lystad H , Lereim I
Published: March 2009

Previous serious skiing injuries were recorded among the participants in the alpine diciplines of the 1994 Olympic Winter Games in Lillehammer, Norway.

Fifty-four racers answered the questionnaire (reply percentage of 21%). Seventy-two percent of the racers had suffered one or more serious skiing injuries previously. The knee accounted for 43% of the injuries, followed by the lower leg (10%) and the head (8%). Forty-two percent of the women and 10% of the men (p < 0.01) had suffered a rupture of the anterior cruciate ligament (ACL). Thirty-six percent of the racers had been injured in downhill, and 21% in each of the three other alpine disciplines. Sixty-two percent reported to be recovered completely from their injuries.

In conclusion, about three fourths of Olympic racers have suffered a previous skiing injury. Female racers were more prone to ACL ruptures than male racers.
Epidemiology of Snowboarding Injuries: 1988 to 1995
Authors: Shealy JE , Ettlinger CF , Buonomox V
Published: March 2009

Between 1988 and 1995 (seven years, or ski seasons) the authors evaluated ski patrol reports of 15 323 downhill skiing injuries and 3696 snowboard skiing injuries that happened during 3 476 515 and 617 081 skier visits (SV), respectively, at two medium-sized ski areas on the west coast of the United States. This resulted in overall, patrol-based, injury rates of 227 and 167 mean days between injury (MDBI) rates for downhill and snowboard skiing, respectively. During the seven seasons, the incidence of snowboard skiing has increased from 4.2% of all skier visits in the first year (1988/1989) to 36.7% in the final season (1994/1995). The overall rate of injury to snowboard skiing participants was 36% higher than alpine skiing. In most respects, the injury patterns of snowboard skiing are significantly different from alpine skiing. Snowboard skiing had a lower rate of lower leg and knee injuries than alpine skiing. Snowboard skiing had a higher percentage of wrist and ankle injuries than alpine skiing. In snowboard skiing, males had a higher percentage (percent of all reported injuries) of ankle and lower leg injuries, while females had a higher percentage of wrist and knee injuries. The incidence (MDBI) of lower leg, ankle, and knee injuries in snowboard skiing improved over the period of the study, while there was not significant change in me wrist rate.
Experimental Case Study with a Modified Ski Boot: Does the Spoiler Design Influence Muscle Activity and Kinematics During Landing?
Authors: Senner V , Schaff P
Published: March 2009

For the investigation of the boot-induced anterior cruciate ligament injury an experimental case study with a prototype ski boot was performed. The back spoiler of this boot was designed to yield by only a few degrees when a certain level of backward moment was reached. A mechanic switch was used to activate or to block this mechanism. Over a prepared hill, a single subject performed ten jumps with an activated mechanism and ten jumps with a blocked spoiler mechanism in randomized order. During the jump and landing, an electromyograph (EMG) of eight lower extremity muscles was recorded and synchronized to two S-VHS cameras that were located for two-dimensional kinematic analysis. The goal of these experiments was to quantify the muscular and kinematic effects caused by the new spoiler characteristics and also to establish a method for their judgment.

For the quantification of the muscular effects, an activity quotient was defined and, for the analysis of the kinematics, the time history of three body angles and their variation between the trials were found to be appropriate. The results of this case study revealed clear differences between the two treatments. In particular, the activity quotient of the hamstring muscles showed a remarkable increase with the spoiler mechanism activated. The findings encourage further investigations in this direction, for example, a randomized field study using the derived method.
Electromechanical Ski Release Binding with Mechanical Backup
Authors: Hull ML , Swanstrom M , Wade B
Published: March 2009

To better protect skiers against injuries to both the lower leg and the knee, releasable bindings that offer certain performance capabilities over current designs are warranted. Two capabilities that would be of immediate benefit are: (1) maintaining a consistent release level in twist in the presence of combined loads; and (2) releasing the heelpiece based on the anterior/posterior (A/P) bending moment transmitted by the leg. A third capability that may be worthwhile is modulating the release level in twist depending on the degree of contraction in muscles crossing the knee. Thus, the objective of this work was to design a binding that offered these capabilities through electronic control of binding release yet at the same time provided a conventional mechanical backup in the event of electronic failure.

To fulfill the objective, a conventional ski binding was modified. Modifications included integrating dynamometers into the toepiece, anti-friction device (AFD), and heelpiece. The toepiece sensor indicates the twisting moment while the AFD and heelpiece sensors indicate the anterior bending moment transmitted by the leg. To gain electronic control of binding release, a solenoid actuated mechanism was added that translated the heelpiece rearward along the ski to decouple the boot from the binding. Otherwise, the binding allowed normal mechanical function. Prototype testing confirmed the ability of the dynamometers to accurately measure desired loads in the presence of extraneous loads and the reliability of the solenoid actuated mechanism in releasing the boot under loads typical of skiing. Thus, this work demonstrated the feasibility of hybrid electromechanical/mechanical releasable bindings. Such a demonstration should encourage the development of designs for commercial use.
Determining the Sensitivity of International Test Methods Designed to Assess the Gas-Tight Integrity of Fully Encapsulating Garments
Authors: Carroll TR , Resha CJ , Vencill CT , Langley JD
Published: March 2009

The American Society of Testing and Materials (ASTM) and the European Committee for Standardization (CEN) have promulgated similar pressure test methods to evaluate the overall gas-tight integrity of fully encapsulating garments. These test methods are contrasted by differences in pre-test conditioning pressures, settling times, starting pressures, and ending pressures. The purpose of this study was to determine the sensitivity of these pressure test methods to garments fabricated from film-based and elastomeric fabrics. Also included was a study to determine normal internal operating pressures measured during the ASTM F1154 standard form, fit, and function protocol. Test method sensitivity was assessed by determining the minimum diameter hole required to induce a failure according to the criteria specified in the relevant pressure test method. Hypodermic needles of specified sizes were used to create leaks in the test garments. Operating pressures were determined during the wear test by monitoring interior suit pressures at three sampling ports. Maximum internal pressures measured during this study appear to lay between those set by ASTM and CEN thus bringing into question, the relative severity and ultimate applicability of these methods.
Protective Materials with Real-Time Puncture Detection Capability
Authors: Hermes RE , Valdez-Boyle LS , Stampfer JF , Ramsey DR
Published: March 2009

The protection of workers from chemical, biological, or radiological hazards requires the use of protective materials that can maintain their integrity during use. An accidental puncture in the protective material can result in a significant exposure to the worker. A five ply material has been developed that incorporates two layers of an electrically conductive polymer sandwiched between three layers of a nonconductive polymer. A normally open circuit that is connected between the conductive layers will be closed by puncturing the material with either a conductive or nonconductive object. This can be used to activate an audible alarm or visual beacon to warn the worker of a breach in the integrity of the material. The worker is not connected to the circuit, and the puncture can be detected in real-time, even when caused by a nonconductor.
Cut Protection Performance Test for Measuring Cut Resistance of Materials Used in Protective Clothing
Authors: Tejani N , Blocker RW , Schiffelbein P , Rivet E
Published: March 2009

A new test method for measuring cut resistance of materials used in protective clothing has been developed. The test method, Cut Protection Performance Test (CPPT), determines cut resistance of a material by measuring its ability to resist the cutting action of a sharp blade under a load. Cut resistance is described as the reference load — the load required to cut the material a distance of 25 mm.

The relative cut resistance of various materials, ranging from thin latex to reinforced composite structures, is examined by comparing their respective reference loads. For most materials, correlation coefficients of 0.75 or better are observed, while composite materials give lower correlation coefficients. The lower correlation is explained by analysis of model fabrics and is attributed to the non-homogeneous nature of the composite materials.

An interlaboratory test program was conducted to determine precision of the test method. The test results showed that despite variability in the predicted values, all seven laboratories consistently ranked the relative cut resistance of ten materials; the method can be used to distinguish cut resistance of various commercial materials. The results of the precision calculations for repeatability and reproducibility are also presented.

ASTM task group F23.20.02 has concluded that the CPP test method is significantly better than the earlier test methods; the test method has been balloted by the main committee for adoption.
Performance of Chemical Protective Gloves in the Film and Print Processing Industry
Authors: Sun QJ , Laing RM , Niven BE , Wilson CA
Published: March 2009

Implicit in the sale of many items of protective clothing is the assumption that they can be cleaned and reused, and that protection of the human body will continue to be provided when the particular products are worn again. However, few products have been assessed with respect to deleterious effects of repeated use and cleaning. There is a statutory requirement in New Zealand that protective clothing for use in workplaces be designed, manufactured, tested, and used so as to give adequate protection from the harm against which it is intended to protect when maintained properly (during and between uses) and in accordance with its use [1, 2]. That is, effects of use and care on performance need to be known.

The purpose of this study was to ascertain effects which repeated use have on performance of chemical protective gloves for one workplace application. Practices for hand protection in a New Zealand sample of print and film processing industries (n = 149) were identified, and performance of a selection of gloves used (nitrile, polyvinyl chloride dipped, disposable polyvinyl chloride film) was examined in the laboratory (tested against methyl ethyl ketone, isopropyl alcohol and Blanket Wash No. 2) as new and after use in the field. Product performance and failure are discussed.
Protective Clothing Fitting Considerations for Pregnant Women
Authors: Manley JW
Published: March 2009

Comfort, fit, and sizing are primary concerns for pregnant women who wear protective clothing. To aid the industry in meeting the needs of these pregnant women, an anthropometric measurement study was completed for women who stated their prior-to-pregnancy size as being size 10, 12, or 14. Measurements were taken at the fifth, seventh, and ninth months of pregnancy. An analysis of measurements taken indicate that circumference measurements (bust, waist, hips, thighs) generally known to change during pregnancy do increase, however, other measurements critical to fit may change during pregnancy and must be taken into consideration to achieve appropriate fit within protective clothing for pregnant women.
Protective Clothing for Workers in Pesticide Manufacturing Plants in India: A Needs Assessment Survey
Authors: Shaw A , Khetan S
Published: March 2009

Use of appropriate personal protective equipment (PPE) reduces pesticide exposure, enhancing the health and safety of individuals. A needs assessment survey was conducted to assist in the development and evaluation of protective clothing that will meet the needs of workers in India. A mail-in survey and follow-up interviews were conducted to obtain information regarding: types of pesticides manufactured, types of clothing worn by workers, laundering procedures, and socio-psychological and economic factors affecting the type of clothing used by workers in pesticide manufacturing plants. Results of the study indicate that cotton and cotton/polyester fabrics are used for pants/shirt and coveralls worn by male workers in pesticide manufacturing plants. Generally, females are not employed in pesticide manufacturing units. A majority of the respondents stated that protective gear is issued by the company to the workers. However, the extent to which they are actually used is questionable. A majority of the companies use on-site and/or contractual laundering facilities. Most of the respondents rated the need for protective clothing for workers exposed to pesticide as high or very high.
Need-Oriented Emergency Care: The Development of Emergency Care Training in the National Ski Patrol System
Authors: Bowman WD
Published: March 2009

The National Ski Patrol (NSP) System was established to provide emergency care and safety education to the skiing public. Although emergency care training for patrollers was based first on the American Red Cross's (ARC) Standard First Aid course and later on the ARC's Advanced First Aid and Emergency Care course, additional training in the types of accidents and injuries seen in a snowy, cold environment has always been necessary. Starting in 1984, NSP developed its own emergency care course, which has been used systemwide since 1987. This is based on the U.S. Department of Transportation's National EMS Standard Curriculum modified as necessary to emphasize cold weather and high-altitude illnesses and injuries, ski injuries, and the special equipment and techniques used by patrollers. Under a fulltime national education director, a system of supervisors, instructor-trainers, and instructors in each NSP division has been developed to teach and refresh the course and provide quality assurance.
Age and Gender: Two Epidemiological Factors in Skiing and Snowboarding Injury
Authors: Cadman R , Macnab AJ
Published: March 2009

Developing injury prevention programs and increasing safety awareness require careful analyses of the population at risk and the determinants of behavior. This retrospective study analyzes 2139 injury reports from Blackcomb Mountain, Canada, during the 1991–1992 season, and shows that age and gender are important epidemiological factors in populations at risk for skiing and snowboarding injuries. Young children and teenagers are the age groups most at risk for injury, and the incidence of head and facial injury is high. Males are the gender most vulnerable to injury. Female injury patterns are different from those in males, particularly with regard to knee injury, and thus female groups should receive specific attention and individual focus in health promotion intervention plans. A single injury prevention strategy attempting to address all age groups and both genders simultaneously would be unlikely to reduce the rate of injury equally throughout skiing and snowboarding populations.
Downhill Skiing Injuries in Lapland, Sweden: A Survey Including Alcohol Monitoring and One-Year Follow-up
Authors: Made C , Elmqvist L-G
Published: March 2009

In Tärnaby/Hemavan, a ski area in Lapland/Sweden, all downhill skiing-injured patients examined at the local medical facility, Tärnaby Sjukstuga, were registered 1990–92. A questionnaire was filled out, the patients' expiration breath was tested by an Alcolmeter SD-2®, and a one-year follow-up was performed by questionnaire. Four hundred eighty-one patients (59% male), mean age 22.9, were included. Injured parts of the body were knee 28%, lower leg and head 10.8%, thumb 8.3%, and forearm 8.1%. The most common diagnoses were fractures 23.6% and knee sprains 23.2%. Classification according to the abbreviated injury scale (AIS) 1 to 5 resulted in 95% as 1–2, 5% as 3–4; one skier had an AIS of 5. On the day of accident 1.1% had used alcohol compared to 5% in a control group of 60 noninjured skiers. The one-year follow-up questionnaire was answered by 58%; 29% of the respondents had symptoms.

Alcohol is a factor of no importance in the incidence of ski injuries at Tärnaby/Hemavan. One third of the follow-up group had enduring symptoms.
Regression Models of Forces and Moments at Potential Sites of Injury Along the Leg in Skiing
Authors: Yee AG , Mote CD
Published: March 2009

Regression models that predict anterior-posterior moment at the boot top (Myb), anterior-posterior force on the tibia (Fxkb), varus-valgus moment at the knee (Mxk), and torsional moment along the tibia (Mzkb) are developed using data from slalom skiing runs for a 15-subject sample. The regressor variables are the lateral and vertical force components measured at the toe and heel bindings. The Myb and Mxk regression model coefficients, standard deviations, and correlation coefficients (r) are dependent on the distance from the center of ankle flexion to the boot top (lb) and to the knee (lk).

It is recommended that the vertical and lateral force components at the toe and heel bindings be considered in future binding designs, because (i) these four force components are the smallest set of forces measured at the bindings required to predict Myb, Fxkb, Mxk, and Mzkb with correlation coefficient r > 0.9 for this subject sample, and (ii) measurements of additional force or moment components do not necessarily increase model accuracy enough to warrant the increased model complexity.

Larger lb (with lb < 0.4 m) likely increases the capability of the state-of-the-art heel binding to control Myb for this subject sample, because the standard deviation decreases as lb increases for the regression model.

The regression models are applied to skiing runs during which slalom turning, forward/backward leaning, falling, and jumping maneuvers are executed by the subjects. The average mean residuals and average standard deviations of residuals (s) are shown graphically as measures of regression model accuracy over these different skiing motions. The average standard deviation of residual of the regression models can vary by more than 100% when the models are applied to different skiing motions. Thus, caution must be exercised if the models are extrapolated to different skiing conditions where no verification of model accuracy exists.
A Method for Obtaining 3-D Data in Alpine Skiing Using Pan-and-Tilt Cameras with Zoom Lenses
Authors: Mössner M , Kaps P , Nachbauer W
Published: March 2009

The direct linear transformation (DLT) was applied for three-dimensional reconstruction in alpine skiing. Because of the large field of view it is necessary to follow the skier with the cameras to receive frames with a sufficiently large image of the skier. In our implementation, the DLT parameters are computed for each frame of each camera separately. Consequently it is possible to rotate the cameras and to zoom the lenses. The locations of the cameras need not be known. Control points were distributed on the slope. Their coordinates were determined by geodetic surveying. The method requires at least six control points visible in each frame. Using more than six control points reduces the reconstruction error considerably. Under optimal conditions the mean errors are less than 5 cm in each coordinate. This accuracy is sufficient for inverse dynamics if the data are smoothed and the sampling frequency is adequate.
Effects of Snow and Air Conditions on Ski Friction
Authors: Nachbauer W , Schröcksnadel P , Lackinger B
Published: March 2009

The friction of skis on snow appears to be affected by numerous factors, for example, speed, contact area, snow type (temperature, liquid-water content, hardness, texture), and ski properties (stiffness, thermal conductivity, base material, base roughness). Most of the knowledge concerning how friction varies with these factors is from laboratory measurements that do not describe the real skiing situation when skis move at high speed under a diversity of snow conditions. The purpose of this study was to demonstrate the influence of a wide range of natural snow and air conditions on the snow friction of a skier gliding down a test course at high speed.

A permanent 342-m-long test run was set up in the ski resort Gschwandtkopf in Seefeld (Tyrol) from January to March 1991. One experienced downhill skier performed 175 runs with the same equipment. The running time of the skier was taken. Maximum skiing speeds up to 30 m/s were reached. For each test run, air temperature and humidity as well as snow variables (snow temperature, liquid-water content, snow density, snow hardness, grain shape, and grain size) were measured.

The results are presented in scattergrams of running time plotted against the environmental variables. Attempts were made to explain the results in context with the basic theory of the friction of snow skis. Though single environmental variables correlate considerably with running time, the results indicate that variations in snow friction cannot be explained by single variables only. Liquid water content was found to be an important snow property. Different frictional processes may dominate on dry and wet snow, respectively. Limitations of the applied method for determining ski-snow friction are discussed.
Skier Trajectories After Loss of Control
Authors: Brown CA , Hoffman AH , Heinzmann RK
Published: March 2009

The literature reports that many of the most serious ski injuries, such as those resulting from a collision with another skier or with a fixed object, occur after skiers have lost control. In this paper calculations are presented of skier trajectories, based on the skier's speed and direction at the moment of loss of control, and the simplifying assumptions of a constant coefficient of friction following the loss of control and a constant steepness of the slope during sliding. These relatively simple, ballistic calculations are used to approximate how far across and down a hill a skier can travel following loss of control, and under what conditions the skier will stop. The trajectories are referenced to the point where the skier's body contacts the snow, and the path of the skier is calculated across the snow surface. In addition, the distance traveled from the point of loss of control to where the skier's body contacts the snow is estimated, and the issue of whether to instruct skiers to fall after losing a ski (without falling) or to attempt to regain control on the remaining ski is discussed. The role that trajectory calculations could play in trail design and in the placement of protective devices is also discussed.
Influences of Ski Boot Binding System on Load Reduction and Kinematics of Lower Leg During Backward Fall: Dynamic Simulation Using an Anthropometric Dummy
Authors: Senner V , Schaff P , Hauser W
Published: March 2009

Several studies show a relationship between spoiler stiffness and the resulting loading on the knee during a boot-induced anterior drawer incident. Carrying on the ideas of these investigations, the purpose of our experimental study was to quantify some of the important loading parameters such as the maximum shear force, the horizontal impulse, or the moment of momentum in relation to various settings of spoiler stiffness and different types of bindings (with and without backward release function).

In order to increase the internal validity of the investigation, the authors used an anthropometric dummy that has been presented by Bahniuk et al. A specially designed indoor slope allowed numerous simulations of the centralized backward fall under reproducible conditions to be performed.

This paper describes the experimental setup, explains and discusses the results of the measurements, and finally gives a short overview of the methodical embedding of this study in the authors' longer-termed investigation of the anterior cruciate ligament (ACL) risk reduction by ski boot design.
Treatment of Cruciate Ligament Injuries in World Cup Racers and Successive Racing Performance
Authors: Ekeland A , Vikne J
Published: March 2009

Rupture of the anterior cruciate ligament (ACL) is considered to be a serious injury in an alpine skiing career. Five Norwegian alpine and freestyle World Cup racers suffered ACL ruptures combined with other knee ligament injuries. Their median age was 25 years (19 to 26 years). Four of the racers were male and one female. All racers underwent surgery within three days of the injury. At a follow-up median of 23 months (15 to 28 months later), all had returned to ski racing. The sagittal knee laxity measured with KT-1000 during maximum manual tibial displacement disclosed a median difference of 3 mm (1 to 8 mm) between the involved and uninvolved knee. The World Cup ranking of the racers was median 7 (2 to 85) before the injury and median 13 (2 to 34) at follow-up.

In conclusion, World Cup ski racers may suffer relatively severe injuries, but racers at this level seem to regain their positions in World Cup competitions after treatment.
Muscle Activity During the Backward Fall—Protection for the ACL?
Authors: Barone MDO , Senner V , Schaff P , Rosemeyer B
Published: March 2009

Anterior cruciate ligament (ACL) injuries are still seen frequently on the slope. The backward fall may cause an ACL rupture. To reduce the load on the knee, the design of a ski boot with a “giving-way” spoiler is discussed. Past studies have excluded the importance of muscle activity during the backward fall. Therefore, this research tends to determine muscle activity depending on the spoiler flexibility. Electromyographic measurements of six test subjects were combined with a two-dimensional motion analysis under controlled laboratory conditions. One ski boot with a stiff spoiler was compared with three flexible spoiler prototypes. The signal of four muscles (m. vastus med., m. vastus lat., m. biceps fem., m. tibialis ant.) was recorded bilaterally. Analysis of the experiments with the stiff spoiler shows a muscular imbalance between quadriceps and hamstring muscles. Unlike this, the flexible spoiler leads to a more balanced muscle activity pattern. Especially the m. biceps femoris shows more activity.

These results could possibly explain the mismatch of calculated mathematical models with the actual injury mechanism. Additionally, they allow the conclusion that appropriate ski boot design stimulates muscle activity and may protect the knee—in particular the ACL.
Injury Mechanism of the Anterior Cruciate Ligament in Alpine Skiing: Case Studies
Authors: Fischer JF , Loureiro O , Leyvraz PF , Bally A
Published: March 2009

The paper reports six case studies of skiers who sustained knee ligament injuries. The aim of this study is to better understand the dynamic mechanisms of anterior cruciate ligament (ACL) rupture in alpine skiing. To make these case studies, skiers were provided with a questionnaire, were diagnosed by either arthroscopy or surgery, had their equipment tested, and were interviewed. The purpose of the questionnaire and the interview was to learn the details of fall mechanics in an effort to infer the loads responsible for injury. The results indicated that in all six cases, injury occurred without binding release. Although the mechanisms varied, the principal loads common to most of the injuries were internal/external axial moments often combined with anterior drawer loads. The improvements on the actual equipment should concern its behavior when confronted with combined loads producing friction in the system. The authors concluded that for lateral release at the toe, there should be a better compensation of the vertical parasite forces and an improvement of the antifriction devices. In order to prevent excessive anterior drawer loads on the ACL an additional release direction of the binding system, especially backwards, could, if properly adjusted, enhance the opportunities of early release in a dangerous backward lean “out of control” position.
Altitude Illness in Skiers: A Worldwide Concern
Authors: Bovard RS , Schoene RB
Published: March 2009

Altitude illness, or acute mountain sickness (AMS), is a common affliction among skiers at elevations between 2000 and 4000 m (about 6500–13 000 ft) (moderate altitude). Studies show that at least one in four persons going to these elevations will develop AMS, more than half of whom will be forced to reduce their activities. The constellation of symptoms associated with this entity ranges from minor inconvenience to debilitating or even fatal episodes in a small number of cases. Many ski resorts and associations have in the past been reluctant to educate skiers about AMS because of the potential economic loss from fear of the sickness. Yet the magnitude of the problem suggests that the cost to the ski industry of not educating skiers about AMS is significantly greater in the long run.

In 1991, however, the Colorado Department of Health, the Colorado Department of Tourism, and Colorado Ski Country—USA, in conjunction with the Colorado Altitude Research Institute (CARI) in Keystone, collaborated on an informational statement to educate skiers about problems associated with fast ascent to altitude. This consortium of health care, tourism, and ski industry leaders is unique and serves as a model for other high-altitude communities.

The interest in promoting greater skier safety and enjoyment, however, is a worldwide concern, whether one skies in the Rocky Mountains, the Andes, or the Alps. The purpose of this paper is to encourage the education of persons of all nationalities who ski or exercise above 2000 m (6561 ft) about altitude illness.
Relationship Between Time Course of Ruffier Index and Stress-Dependent Heart Rate During Eight Days of Skiing/Snowboarding
Authors: Hofmann P , Stockinger B
Published: March 2009

The aim of this study was evaluation of stress-dependent heart rate (HR) and fatigue during one week of a ski/snowboard (S/S) education program involving skilled male students to prove the hypothesis of greatest fatigue on the third day of stress. The Ruffier Index (RI) was used as an index of fatigue. Mean HR, HRmin and HRmax during S/S decreased significantly during the first five days as well as pre-exercise RI. Post-S/S RI did not change significantly during the first days. The greatest difference between pre- and post-S/S was found on the 3rd day. Although mean HR and HRmax decreased, the difference between pre- and post-S/S RI increased up to the 3rd day. The study supported the hypothesis of greatest fatigue on the 3rd day of S/S in young skilled students.
Fuzzy Logic Control of Bioadaptive Ski Binding Release
Authors: Crawford RP , Mote CD
Published: March 2009

The relationships between moments predicted at the frequent sites of injury during snow skiing and “high” and “low” electromyographic measures and weight bearing in the leg are used to develop a ski binding release algorithm that continuously controls the retention setting. The algorithm is based on concepts of fuzzy logic. Simulations of the performance of the algorithm, tested with data collected during 101 ski test runs in field experiments, revealed nine different actual release/retention actions than occurred with the conventional binding during the experiments. In five cases where the conventional binding released possibly prematurely, the simulated algorithm did not predict release. In two cases when the subject fell during moderate weight bearing and muscle contraction, the conventional binding did not release and the algorithm predicted twist release.

The algorithm demonstrates promise to address simultaneously some of the key problems of inadvertent and inadequate binding release. These results suggest that reduction of the number of inadvertent releases requires better prediction of the forces and moments at the sites of potential injury, and binding designs that reduce the retention threshold during intervals of low weight bearing and muscle contraction may also better control the forces and moments at the sites of potential injury.
A New Electromechanical Ski Binding with Release Sensitivity to Torsion and Bending Moments Transmitted by the Leg
Authors: Neptune RR , Hull ML
Published: March 2009

Described in this paper is the design of a new electromechanical ski binding where release in both twist and forward bending is controlled electronically and the release level in twist is modulated electronically based on the neural stimulation of one of the vastii muscles in the quadriceps group. To provide signals for controlling release in the two modes, the binding incorporates two dynamometers. Each dynamometer measures loads which have been shown to correlate strongly (r2 > 0.90) to torsional and bending moments at the lower leg injury sites. Although the binding consists of both a toepiece and heelpiece, the toepiece does not permit release of the boot from the ski in the twist mode but rather serves as one of the dynamometers. Consequently the heelpiece was specifically designed to provide the release function in both modes. Release is realized by a low-force solenoid which actuates a multilink trigger mechanism. To prove the feasibility of the binding, a prototype was constructed and evaluated.
Standard Methods and Materials for Mitigating Injuries from Impact with Fixed Obstacles at U.S. SKi Areas
Authors: Penniman D
Published: March 2009

A plethora of products and techniques are currently employed at commercial ski areas to help prevent or reduce injuries from impact with man-made structures and other obstacles. The design and function of these products and techniques range from warnings and education to impact prevention. This paper describes the most popular mitigation measures currently in use and, where recent laboratory tests or field experience or both are available, explains their effectiveness. Some recent innovations are also discussed.
The Snowboarder's Talus Fracture
Authors: Paul CC , Janes PC
Published: March 2009

A four-year nonrandomized retrospective clinical study was instituted to ascertain the pattern of injuries sustained by participants of snowboarding. One thousand four hundred and fifteen questionnaires representing 1507 physician-seen and diagnosed snowboarding injuries were collected from 1988 through 1992.

Forty-eight participants reported lateral ankle pain and were diagnosed with a fracture of the lateral process of the talus. Twenty-three of the 48 patients participated in a follow-up questionnaire detailing their treatment, current pain level, and function.

All of the fractures were intra-articular and into the posterior facet of the talocalcaneal joint. Diagnosis often required tomograms, computerized tomography (CT), or magnetic resonance imaging (MRI) studies to detail fragment size, displacement, and degree of comminution.

Four patients underwent early open reduction internal fixation (ORIF) with three excellent and one good short-term result. The remaining 19 were treated with casting, splinting or limited weight bearing or both. Fifteen of those treated nonoperatively reported varying degrees of symptoms without complete recovery, including four patients who have been diagnosed with a symptomatic nonunion requiring further treatment. One fracture was diagnosed more than two years after the original injury.

This fracture may be easily missed on X-ray, making diagnosis difficult; thus an aggressive diagnostic approach is recommended. Large or significantly displaced fractures may respond better to more aggressive treatment, including early ORIF or excision.
A Comparison of Electrochemical Noise and Impedance Spectroscopy for the Detection of Corrosion in Reinforced Concrete
Authors: Bertocci U
Published: March 2009

Electrochemical impedance spectroscopy (EIS) and electrochemical noise measurements (ENM) were carried out on small concrete blocks with embedded steel rods, immersed in solutions of highway deicers, mainly sodium or magnesium chlorides with corrosion inhibitors added. Voltage and current fluctuations between identical electrodes were recorded, and different signal-processing schemes were tested. Various problems experienced in the course of the work are described. Corrosion polarization resistances obtained by EIS are compared with values of the ratio of the standard deviations of the voltage and current fluctuations. The results suggest that the type of ENM used in this work is subject to considerable uncertainties, and further work would be necessary before the method can be applied with sufficient confidence to corrosion monitoring.
Quantifying the Stochastic Behavior of Electrochemical Noise Measurement During the Corrosion of Aluminum
Authors: Roberge PR
Published: March 2009

This paper describes a study of electrochemical measurements that included the analysis of potential noise fluctuations recorded during the free corrosion of a strain-hardened aluminum alloy exposed to an aerated saline solution. The analysis of spontaneous electrochemical noise (EN) generated during these experiments was made by various analysis techniques specifically designed to reveal the stochastic and fractal nature of signals and shapes. The paper demonstrates how rescaled range analysis and stochastic process detector techniques can serve to highlight features present in the frequency domain of transformed data records. It is also shown that the corrosion cell made with aluminum exposed to an aqueous aerated saline solution is an excellent source of noise, which can be easily varied by changing the pH of the solution to force depassivation phenomena. The analysis of spontaneous EN by complementary methods is demonstrated to be a practical approach for the identification of the physical phenomena causing the EN. It is also demonstrated that monitoring the electrochemical impedance spectroscopy behavior in parallel to EN can be valuable because it helps to establish some fundamental correlations in real time and define the sensitivity of each technique under similar conditions. In the present study, the drastic changes recorded by EN measurements when the solution pH was slightly reduced are indicative of the tremendous sensitivity of EN monitoring to changes in the corroding environment.
Reproducibility of Electrochemical Noise Data from Coated Metal Systems
Authors: Bierwagen GP , Mills DJ , Tallman DE , Skerry BS
Published: March 2009

The use of electrochemical noise (ECN) as a method to characterize the corrosion-protection properties of organic coatings on metal substrates was pioneered by Skerry and Eden, and since then has been used by others as a probe for coating metal corrosion studies. However, no statistical examination of the reproducibility of the data from such measurements has been published. In the data we present, we have done a systematic analysis of important experimental variables in such systems. We have examined the method for accuracy and reproducibility with respect to sample preparation, sample immersion, and metal substrate preparation. We have taken several marine coatings systems typical of U.S. Navy use, prepared duplicate samples of coating metal systems, and examined them under the same immersion exposure. The variables we considered for reproducibility are paint application (in three-coat systems), metal panel preparation (grit-blasted steel), and immersion conditions. We present ECN data with respect to immersion time on the values of noise voltage standard deviation σV, noise current standard deviation σl, and the noise resistance Rn as given by σV/σl. The variation among supposedly identical sample pairs in identical immersion monitored under identical conditions is presented. The statistics of the time records of the data are considered, and the variations with respect to specific coatings classes are also considered within the limits of the data. Based on these data, comments concerning ECN on coated metal systems as a predictive test method are presented along with special considerations that must be made to properly use the method for coating ranking and lifetime prediction.
Instrumented Impact Testing of Subsize Charpy V-Notch Specimens
Authors: Kalthoff JF , Gregor M
Published: March 2009

The instrumented impact test with Charpy specimens of subsize geometry is discussed in relation to equivalent standard procedures for performing the test with specimens of regular size. Subsize specimens because of their smaller dimensions imply smaller load values and higher frequencies of the force oscillations. These differences in the behaviour require special high sensitivity striker tups, force measuring chains of high upper frequency bounds, and knowledge of the actual Hooke's line for determining the yield force Fgy. Practical recommendations are given and procedures are outlined on how these requirements can be met and how the evaluations can be performed. The applicability of the presented measuring and evaluation procedures and the validity and the accuracy of the obtained data is demonstrated by experimental results.
Small Specimen Testing Applied at Surveillance Extension
Authors: Czoboly E , Gillemot F , Oszwald F
Published: March 2009

The WWER-440 V-213 type RPVs are equipped with the surveillance specimens used to predict the embrittlement of the RPV material. These specimens are located near the core, resulting in accelerated irradiation. After four years of operation only one overexposed set remains in each unit. To obtain a more extensive database for life time calculation and life time management, a new, more extended surveillance program has been elaborated and implemented. Due to the limited availability of archive materials reconstructed Charpy V specimens and small size smooth and notched tensile bars were used in the program. To develop this surveillance extension, an extensive laboratory study on use of reconstructed Charpy and subsize tensile specimens was performed. Methods for K1a measurements on small size specimens were also studied.